G2Cdb::Gene report

Gene id
Gene symbol
Homo sapiens
microtubule-associated protein tau
G00001036 (Mus musculus)

Databases (8)

ENSG00000186868 (Ensembl human gene)
4137 (Entrez Gene)
970 (G2Cdb plasticity & disease)
MAPT (GeneCards)
157140 (OMIM)
Marker Symbol
HGNC:6893 (HGNC)
Protein Expression
151 (human protein atlas)
Protein Sequence
P10636 (UniProt)

Synonyms (8)

  • FLJ31424
  • FTDP-17
  • MGC138549
  • MSTD
  • MTBT1
  • MTBT2
  • PPND
  • tau

Literature (604)

Pubmed - other

  • New genes, new dilemmas: FTLD genetics and its implications for families.

    Goldman JS, Adamson J, Karydas A, Miller BL and Hutton M

    Sergievsky Center and Taub Institute, Columbia University, New York, NY 10036, USA. jg2673@columbia.edu

    After Alzheimer's disease, frontotemporal lobar degeneration (FTLD) is the second leading cause of dementia in persons less than 65 years of age. Up to 40% of FTLD cases have a positive family history. Research on these families has led to the discovery of four disease-causing genes: microtubule-associated protein tau (MAPT), progranulin (PGRN), valosin-containing protein (VCP), and charged multivesicular body protein 2B (CHMP2B). MAPT and PGRN are responsible for the largest number of familial cases. Each of these genes differs by disease mechanism. Moreover mutations in both genes are associated with significant interfamilial and intrafamilial phenotypic variation. Genetic counseling needs to address the differences between the PGRN and MAPT mutations as well as the variation in clinical symptoms. The aims of this article are to describe the genetics of the FTLD spectrum and aid in the genetic counseling of individuals who may carry genetic mutations.

    Funded by: NIA NIH HHS: P01 AG019724

    American journal of Alzheimer's disease and other dementias 

  • No replication of genetic association between candidate polymorphisms and Alzheimer's disease.

    Cousin E, Macé S, Rocher C, Dib C, Muzard G, Hannequin D, Pradier L, Deleuze JF, Génin E, Brice A and Campion D

    Biological Sciences Department, sanofi-aventis Recherche et Développement, Centre de Génétique humaine, 91057 Evry, France.

    Alzheimer's disease is a genetically complex disorder, for which new putative susceptibility genes are constantly proposed in the literature. We selected 16 candidate genes involved in biological pathways closely related to the pathology, and for which a genetic association with Alzheimer's disease was previously detected: ACE, BACE1, BDNF, ECE1, HSPG2, IDE, IL1a, IL6, IL10, MAPT, PLAU, PrnP, PSEN1, SORL1, TFCP2 and TGFb1. The variants originally associated with the disease were genotyped in a French Caucasian sample including 428 cases and 475 controls and tested for association in order to replicate the initial results. Despite a careful replication study design, we failed to validate the initial findings for any of these variants, with the possible exception of MAPT, SORL1 and TFCP2 for which some nominal but inconsistent evidence of association was observed.

    Neurobiology of aging 2011;32;8;1443-51

  • Different MAPT haplotypes are associated with Parkinson's disease and progressive supranuclear palsy.

    Ezquerra M, Pastor P, Gaig C, Vidal-Taboada JM, Cruchaga C, Muñoz E, Martí MJ, Valldeoriola F, Aguilar M, Calopa M, Hernandez-Vara J and Tolosa E

    Institut Clínic de Neurociències, Hospital Clínic de Barcelona, Department of Medicine, Universitat de Barcelona, IDIBAPS, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Catalonia, Spain.

    The H1 MAPT haplotype in the 17q21 chromosomal region has been associated with several neurodegenerative diseases. Some reports have suggested that there is an association between genetic variants within the H1 haplotype with Parkinson's disease (PD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Here we report a genetic association study using seven SNPs located along the 17q21 region, in PD patients and controls. In addition, we compared these results with a dataset of previously published PSP/CBD patients from the same population. Our results show that the H1-rs242557(G) allele sub-haplotype is increased in PD (p=0.005), while the H1-rs242557(A) allele sub-haplotype is increased in PSP/CBD (p=0.0002), comparing to controls. The rs242557 polymorphism could act modulating the phenotypic expressivity of the H1 risk on these parkinsonisms. The location of this polymorphism in the 5' regulatory region of MAPT gene suggests the presence of a functional mechanism involved in the variation of MAPT expression levels.

    Neurobiology of aging 2011;32;3;547.e11-6

  • Association of the MAPT locus with Parkinson's disease.

    Wider C, Vilariño-Güell C, Jasinska-Myga B, Heckman MG, Soto-Ortolaza AI, Cobb SA, Aasly JO, Gibson JM, Lynch T, Uitti RJ, Wszolek ZK, Farrer MJ and Ross OA

    Department of Neuroscience, Mayo Clinic, Molecular Genetics Laboratory and Core, Morris K. Udall Parkinsons Disease Research Center of Excellence, Jacksonville, FL 32224, USA. wider.christian@mayo.edu

    Whilst an association between the tau gene (MAPT)-containing H1 haplotype and supranuclear gaze palsy (PSP) has long been recognized, the effect of H1 on risk for Parkinson's disease (PD) has remained more contentious.

    Methods: Herein, we examined the association of H1 and PD in three Caucasian PD patient-control series from Ireland, Norway, and the US (combined: n = 2619), by genotyping two H1/H2 single nucleotide polymorphisms (SNPs) in MAPT (rs1052553) and in the Saitohin gene (rs62063857) and one H1-specific SNP (rs242557).

    Results: We identified a significant association between H1/H2 and risk of PD (rs1052553 OR: 1.43, CI: 1.23-1.64; rs62063857 OR: 1.45, CI: 1.27-1.67), but no effect of the H1-specific SNP rs242557 (OR: 0.92, CI: 0.82-1.03).

    Conclusions: Our findings show that the H1 haplotype is a significant risk factor for PD. However, one H1-specific SNP (rs242557) previously implicated in PSP did not alter the risk of PD, indicating that distinct H1 sub-haplotypes probably drive the associations with PD and PSP.

    Funded by: Canadian Institutes of Health Research: 121849; NIA NIH HHS: P01 AG017216, R01 AG015866; NINDS NIH HHS: P01 NS040256, P50 NS040256, P50 NS40256, R01 NS057567

    European journal of neurology 2010;17;3;483-6

  • Genome-wide association study confirms SNPs in SNCA and the MAPT region as common risk factors for Parkinson disease.

    Edwards TL, Scott WK, Almonte C, Burt A, Powell EH, Beecham GW, Wang L, Züchner S, Konidari I, Wang G, Singer C, Nahab F, Scott B, Stajich JM, Pericak-Vance M, Haines J, Vance JM and Martin ER

    John P. Hussman Institute for Human Genomics, University of Miami, FL 33136, USA.

    Parkinson disease (PD) is a chronic neurodegenerative disorder with a cumulative prevalence of greater than one per thousand. To date three independent genome-wide association studies (GWAS) have investigated the genetic susceptibility to PD. These studies implicated several genes as PD risk loci with strong, but not genome-wide significant, associations. In this study, we combined data from two previously published GWAS of Caucasian subjects with our GWAS of 604 cases and 619 controls for a joint analysis with a combined sample size of 1752 cases and 1745 controls. SNPs in SNCA (rs2736990, p-value = 6.7 x 10(-8); genome-wide adjusted p = 0.0109, odds ratio (OR) = 1.29 [95% CI: 1.17-1.42] G vs. A allele, population attributable risk percent (PAR%) = 12%) and the MAPT region (rs11012, p-value = 5.6 x 10(-8); genome-wide adjusted p = 0.0079, OR = 0.70 [95% CI: 0.62-0.79] T vs. C allele, PAR%= 8%) were genome-wide significant. No other SNPs were genome-wide significant in this analysis. This study confirms that SNCA and the MAPT region are major genes whose common variants are influencing risk of PD.

    Funded by: NIA NIH HHS: U24 AG021886; NINDS NIH HHS: NS39764, P50 NS039764, P50 NS039764-10S40003

    Annals of human genetics 2010;74;2;97-109

  • Heterogeneous nuclear ribonucleoprotein E3 modestly activates splicing of tau exon 10 via its proximal downstream intron, a hotspot for frontotemporal dementia mutations.

    Wang Y, Gao L, Tse SW and Andreadis A

    Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.

    The microtubule-associated protein tau is important to normal neuronal activity in the mammalian nervous system. Aggregated tau is the major component of neurofibrillary tangles (NFTs), structures present in the brains of people affected by neurodegenerative diseases called tauopathies. Tauopathies include Alzheimer's disease (AD), frontotemporal dementia with Parkinsonism (FTDP) and the early-onset dementia observed in Down syndrome (DS; trisomy 21). Splicing misregulation of adult-specific exon 10 results in expression of abnormal ratios of tau isoforms, leading to FTDP. Positions +3 to +19 of the intron downstream of exon 10 define a hotspot: Point mutations in it result in tauopathies. All these mutations increase exon 10 inclusion except for mutation +19, which almost entirely excludes exon 10. To investigate the tau connection between DS and AD, we examined splicing factors located on chromosome 21 for their effect on tau exon 10. By co-transfections, co-immunoprecipitations and RNAi constructs, we discovered that one of them, hnRNPE3 (PCBP3), modestly activates splicing of exon 10 by interacting with its proximal downstream intron around position +19. These results, coupled with the developmental profile of hnRNPE3, suggest a pathogenic role for splicing factors on chromosome 21 in neurodegenerative diseases with tangles and create a connection between tau splicing and the early-onset dementia of Down syndrome.

    Funded by: NICHD NIH HHS: R21 HD056195, R21 HD056195-02

    Gene 2010;451;1-2;23-31

  • Establishing short-term prognosis in Frontotemporal Lobar Degeneration spectrum: role of genetic background and clinical phenotype.

    Borroni B, Grassi M, Agosti C, Premi E, Archetti S, Alberici A, Bellelli G, Caimi L, Di Luca M and Padovani A

    Centre for Aging Brain and Dementia, Department of Neurology, University of Brescia, 1-25100 Brescia, Italy. bborroni@inwind.it

    Background: Establishing the short-term prognosis in Frontotemporal Lobar Degeneration (FTLD) is a clinical challenge for defining disease outcomes and monitoring therapeutic interventions. No reliable neuropsychological assessment balancing all FTLD aspects is available yet, thus no clear-cut follow-up study has been performed.

    Objective: To evaluate the rate of progression and the predictors of worsening in FTLD patients.

    Methods: One-hundred twenty-seven FTLD patients entered the study and were re-evaluated at 1-year follow-up. A statistical driven approach on wide neuropsychological, behavioral, and functional data was applied to identify homogeneous groups both at baseline and at follow-up within FTLD. Three set of predictors on disease progression were considered: (i) the demographic characteristics, (ii) the genetic background, i.e. Apolipoprotein E (APOE) genotype, Tau haplotype, and functional polymorphisms affecting serotonin and dopamine pathways, and (iii) the clinical phenotype.

    Results: Among FTLD, two groups of patients were recognized on the basis of the overall assessment, thus termed for different disease severity as "good performers" and "bad performers". At 1-year follow-up, almost 30% of FTLD patients progressed from "good" to "bad" performances, whilst 70% maintained stable "good" performances. APOE varepsilon4 allele, Tau H2 haplotype and behavioral variant FTD phenotype were associated with worse prognosis over time.

    Conclusions: This preliminary study proposed genetic and clinical predictors in FTLD progression. The identification of disease-modifying predictors of prognosis opens a new avenue in studying FTLD, and may contribute to define outcomes and to monitor pharmacological targets.

    Neurobiology of aging 2010;31;2;270-9

  • Slowing of EEG correlates with CSF biomarkers and reduced cognitive speed in elderly with normal cognition over 4 years.

    Stomrud E, Hansson O, Minthon L, Blennow K, Rosén I and Londos E

    Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, S-205 02 Malmö, Sweden. erik.stomrud@med.lu.se

    Background: Cerebrospinal fluid (CSF) biomarkers and quantitative EEG show particular patterns of change in Alzheimer's disease (AD) and reflect neuropathologic processes and cerebral function, respectively. The changes precede cognitive decline and should be visible already in preclinical stages. We therefore aimed to investigate their relationship in cognitively healthy individuals.

    Method: Thirty-three (33) elderly individuals with repeated normal scores on cognitive tests over 4.5 years underwent EEG recording with quantitative frequency analysis and analysis of CSF total tau (T-tau), phosphorylated tau (P-tau) and beta-amyloid(1-42) (Abeta42).

    Results: CSF T-tau and P-tau correlated with relative EEG theta power (r(s)>0.545; p<0.01), but not with relative alpha, beta or delta power. The combined P-tau/Abeta42 ratio exhibited an even stronger correlation with relative theta power (r(s)=0.622; p<0.001), especially in the right posterior quadrant of the head (r(s)=0.643; p<10(-4)). Slowing of cognitive speed correlated with increased relative theta power, foremost in the posterior quadrants (r(s)>0.503; p<0.01), and high P-tau/Abeta42 ratio (r(s)>0.462; p<0.01).

    Conclusions: Our results suggest that already in cognitively healthy elderly subjects, biochemical changes in CSF, and the possible underlying neuropathologic processes it reflects, have an effect on cerebral function as visualized by the EEG rhythm and cognitive speed. It hereby suggests that CSF biomarkers and EEG theta activity might indicate early abnormal degenerative changes in the brain.

    Neurobiology of aging 2010;31;2;215-23

  • Tau 6D and 6P isoforms inhibit polymerization of full-length tau in vitro.

    Lapointe NE, Horowitz PM, Guillozet-Bongaarts AL, Silva A, Andreadis A and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, 60611, USA. lapointe@lifesci.ucsb.edu

    Alzheimer's disease and other tauopathies are characterized by the intracellular accumulation of insoluble filaments of the microtubule-associated protein tau. The six canonical tau isoforms in the adult brain consist of an N-terminal "projection" domain followed by a proline-rich region, a microtubule-binding repeat region, and a C-terminal tail. However, alternative splicing in exon 6 produces an additional set of tau isoforms, termed 6D and 6P, which contain only the N-terminus and part of the proline-rich region. We have previously shown that constructs representing N-terminal fragments of tau, which resemble the naturally occurring 6P and 6D isoforms, inhibit polymerization of the full-length protein in an in vitro filament formation assay and traced the inhibitory activity to amino acids 18-42. Here we report that 6P and 6D tau isoforms inhibit polymerization of full-length tau (hTau40) in a similar manner, likely by stabilizing full-length tau in a soluble conformation. The absence of exons 2 and 3 decreased the effectiveness of the 6D isoforms but not the 6P variants or the N-terminal tau fragments from our previous study, indicating that the 18-42 region is not the sole determinant of inhibitory ability. Finally, this paper demonstrates that inhibition is blocked by pseudophosphorylation of tyrosines 18 and 29, providing a potential link between tyrosine phosphorylation and disease progression. Taken together, these results indicate that the 6P/6D isoforms are potential endogenous inhibitors of tau filament formation and suggest a mechanism by which this ability may be disrupted in disease.

    Funded by: NIA NIH HHS: AG09466, P01 AG009466, P01 AG009466-180008; NINDS NIH HHS: F31 NS049834, F31 NS049834-02, NS049834

    Biochemistry 2009;48;51;12290-7

  • Low micromolar zinc accelerates the fibrillization of human tau via bridging of Cys-291 and Cys-322.

    Mo ZY, Zhu YZ, Zhu HL, Fan JB, Chen J and Liang Y

    State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.

    A hallmark of a group of neurodegenerative diseases such as Alzheimer disease is the formation of neurofibrillary tangles, which are principally composed of bundles of filaments formed by microtubule-associated protein Tau. Clarifying how natively unstructured Tau protein forms abnormal aggregates is of central importance for elucidating the etiology of these diseases. There is considerable evidence showing that zinc, as an essential element that is highly concentrated in brain, is linked to the development or progression of these diseases. Herein, by using recombinant human Tau fragment Tau(244-372) and its mutants, we have investigated the effect of zinc on the aggregation of Tau. Low micromolar concentrations of Zn(2+) dramatically accelerate fibril formation of wild-type Tau(244-372) under reducing conditions, compared with no Zn(2+). Higher concentrations of Zn(2+), however, induce wild-type Tau(244-372) to form granular aggregates in reducing conditions. Moreover, these non-fibrillar aggregates assemble into mature Tau filaments when Zn(2+) has been chelated by EDTA. Unlike wild-type Tau(244-372), low micromolar concentrations of Zn(2+) have no obvious effects on fibrillization kinetics of single mutants C291A and C322A and double mutant C291A/C322A under reducing conditions. The results from isothermal titration calorimetry show that one Zn(2+) binds to one Tau molecule via tetrahedral coordination to Cys-291 and Cys-322 as well as two histidines, with moderate, micromolar affinity. Our data demonstrate that low micromolar zinc accelerates the fibrillization of human Tau protein via bridging Cys-291 and Cys-322 in physiological reducing conditions, providing clues to understanding the relationship between zinc dyshomeostasis and the etiology of neurodegenerative diseases.

    The Journal of biological chemistry 2009;284;50;34648-57

  • An association study of common variation at the MAPT locus with late-onset Alzheimer's disease.

    Abraham R, Sims R, Carroll L, Hollingworth P, O'Donovan MC, Williams J and Owen MJ

    Department of Psychological Medicine, Cardiff University School of Medicine, Heath Park, UK.

    The MAPT gene that encodes Tau is located on chromosome 17q21, in a region, which has evolved to form two major haplotypes, H1 and H2. There is strong evidence that the H1 haplotype, and a sub-haplotype (H1C), are overrepresented and associated with increased risk for the sporadic tauopathies, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Both PSP and CBD cases display Tau pathology similar to Late-Onset Alzheimer's Disease (LOAD). However, numerous association studies investigating the genetic involvement of MAPT in LOAD have generated conflicting results. Here we have used a large LOAD case-control sample to genotype SNPs that have been shown to define H1/H2 status and intra-H1 variability. Single marker association analyses found no evidence that any of the SNPs are associated with risk of LOAD. When gender and APOE4 status were taken into account we observed suggestive association for SNP rs242557 (P = 0.02). Stratification of the sample revealed association with rs242557 only in APOE4 positive individuals (P = 0.01 recessive model), however this result would not survive multiple correction. There was no significant difference in H1/H2 haplotype distribution between cases and controls. We also tested the association of specific sub-haplotypes on the H1 background and likewise results were negative. No effect was observed on disease age of onset for any of the markers studied. In summary, we find no evidence for allelic or haplotypic association, with SNPs in the MAPT gene and LOAD. SNP rs242557 is nominally significant in the APOE4 positive individuals. None of the SNPs studied modified AAO for LOAD.

    Funded by: Medical Research Council: G0300429

    American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 2009;150B;8;1152-5

  • CSF biomarker levels in early and late onset Alzheimer's disease.

    Bouwman FH, Schoonenboom NS, Verwey NA, van Elk EJ, Kok A, Blankenstein MA, Scheltens P and van der Flier WM

    Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. femke.bouwman@vumc.nl

    Objective: To compare CSF levels of beta-amyloid 1-42 (Abeta(1-42)), total tau (tau) and tau phosphorylated at threonine 181 (ptau-181) between AD patients and controls according to age.

    Methods: 248 AD patients (48% men) and 127 controls (51% men, 22 volunteers and 105 subjective complainers) underwent lumbar puncture. Both patients and controls were divided into a young (<65 years) and old (>or=65 years) group.

    Results: All three biomarkers showed main effects of diagnosis (p<0.001). There was an interaction between diagnosis and age for all three biomarkers (p<0.05), as old controls had lower Abeta(1-42) and higher (p)tau than young controls (Abeta(1-42) 699+/-250 versus 866+/-191pg/ml, tau 408+/-245 versus 243+/-102pg/ml, ptau-181 60+/-28 versus 42+/-15pg/ml), but there was no difference according to age among AD patients (Abeta(1-42) 451+/-178 versus 425+/-146pg/ml, tau 741+/-460 versus 798+/-467pg/ml, ptau-181 91+/-42 versus 91+/-41pg/ml).

    Conclusion: We found that the older control group had lower Abeta(1-42) and higher (p)tau compared to the younger control group. This suggests that older individuals may have AD pathology, even in the absence of objective cognitive impairment.

    Neurobiology of aging 2009;30;12;1895-901

  • Genome-wide association study reveals genetic risk underlying Parkinson's disease.

    Simón-Sánchez J, Schulte C, Bras JM, Sharma M, Gibbs JR, Berg D, Paisan-Ruiz C, Lichtner P, Scholz SW, Hernandez DG, Krüger R, Federoff M, Klein C, Goate A, Perlmutter J, Bonin M, Nalls MA, Illig T, Gieger C, Houlden H, Steffens M, Okun MS, Racette BA, Cookson MR, Foote KD, Fernandez HH, Traynor BJ, Schreiber S, Arepalli S, Zonozi R, Gwinn K, van der Brug M, Lopez G, Chanock SJ, Schatzkin A, Park Y, Hollenbeck A, Gao J, Huang X, Wood NW, Lorenz D, Deuschl G, Chen H, Riess O, Hardy JA, Singleton AB and Gasser T

    Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA.

    We performed a genome-wide association study (GWAS) in 1,713 individuals of European ancestry with Parkinson's disease (PD) and 3,978 controls. After replication in 3,361 cases and 4,573 controls, we observed two strong association signals, one in the gene encoding alpha-synuclein (SNCA; rs2736990, OR = 1.23, P = 2.24 x 10(-16)) and another at the MAPT locus (rs393152, OR = 0.77, P = 1.95 x 10(-16)). We exchanged data with colleagues performing a GWAS in Japanese PD cases. Association to PD at SNCA was replicated in the Japanese GWAS, confirming this as a major risk locus across populations. We replicated the effect of a new locus detected in the Japanese cohort (PARK16, rs823128, OR = 0.66, P = 7.29 x 10(-8)) and provide supporting evidence that common variation around LRRK2 modulates risk for PD (rs1491923, OR = 1.14, P = 1.55 x 10(-5)). These data demonstrate an unequivocal role for common genetic variants in the etiology of typical PD and suggest population-specific genetic heterogeneity in this disease.

    Funded by: Intramural NIH HHS: Z01 AG000949-03; Medical Research Council: G0400000, G0701075, G0901254, G108/638; NCATS NIH HHS: UL1 TR000448; NCRR NIH HHS: UL1 RR024992; NIA NIH HHS: Z01 AG000949; NIEHS NIH HHS: Z01 ES101986; NINDS NIH HHS: R01 NS041509, R01 NS041509-09, R01 NS050425, R01 NS050425-05, R01 NS058714, R01 NS058714-03; Parkinson's UK: G-0907, G-0909, J-0804

    Nature genetics 2009;41;12;1308-12

  • Divergent pathways mediate spine alterations and cell death induced by amyloid-beta, wild-type tau, and R406W tau.

    Tackenberg C and Brandt R

    Department of Neurobiology, University of Osnabrück, D-49076 Osnabrück, Germany.

    Alzheimer's disease is characterized by synaptic alterations and neurodegeneration. Histopathological hallmarks represent amyloid plaques composed of amyloid-beta (Abeta) and neurofibrillary tangles containing hyperphosphorylated tau. To determine whether synaptic changes and neurodegeneration share common pathways, we established an ex vivo model using organotypic hippocampal slice cultures from amyloid precursor protein transgenic mice combined with virus-mediated expression of EGFP-tagged tau constructs. Confocal high-resolution imaging, algorithm-based evaluation of spines, and live imaging were used to determine spine changes and neurodegeneration. We report that Abeta but not tau induces spine loss and shifts spine shape from mushroom to stubby through a mechanism involving NMDA receptor (NMDAR), calcineurin, and GSK-3beta activation. In contrast, Abeta alone does not cause neurodegeneration but induces toxicity through phosphorylation of wild-type (wt) tau in an NMDAR-dependent pathway. We show that GSK-3beta levels are elevated in APP transgenic cultures and that inhibiting GSK-3beta activity or use of phosphorylation-blocking tau mutations prevented Abeta-induced toxicity of tau. FTDP-17 tau mutants are differentially affected by Abeta. While R406W tau shows increased toxicity in the presence of Abeta, no change is observed with P301L tau. While blocking NMDAR activity abolishes toxicity of both wt and R406W tau, the inhibition of GSK-3beta only protects against toxicity of wt tau but not of R406W tau induced by Abeta. Tau aggregation does not correlate with toxicity. We propose that Abeta-induced spine pathology and tau-dependent neurodegeneration are mediated by divergent pathways downstream of NMDAR activation and suggest that Abeta affects wt and R406W tau toxicity by different pathways downstream of NMDAR activity.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2009;29;46;14439-50

  • The proline-rich domain of tau plays a role in interactions with actin.

    He HJ, Wang XS, Pan R, Wang DL, Liu MN and He RQ

    Institute of Biophysics, Chinese Academy of Sciences, Beijing, PR China. hehaijin1981@gmail.com

    Background: The microtubule-associated protein tau is able to interact with actin and serves as a cross-linker between the microtubule and actin networks. The microtubule-binding domain of tau is known to be involved in its interaction with actin. Here, we address the question of whether the other domains of tau also interact with actin.

    Results: Several tau truncation and deletion mutants were constructed, namely N-terminal region (tauN), proline-rich domain (tauPRD), microtubule binding domain (tauMTBD) and C-terminal region (tauC) truncation mutants, and microtubule binding domain (tauDeltaMTBD) and proline-rich domain/microtubule binding domain (tauDeltaPRD&MTBD) deletion mutants. The proline-rich domain truncation mutant (tauPRD) and the microtubule binding domain deletion mutant (tauDeltaMTBD) promoted the formation of actin filaments. However, actin assembly was not observed in the presence of the N-terminal and C-terminal truncation mutants. These results indicate that the proline-rich domain is involved in the association of tau with G-actin. Furthermore, results from co-sedimentation, solid phase assays and electron microscopy showed that the proline-rich domain is also capable of binding to F-actin and inducing F-actin bundles. Using solid phase assays to analyze apparent dissociation constants for the binding of tau and its mutants to F-actin resulted in a sequence of affinity for F-actin: tau > microtubule binding domain > proline-rich domain. Moreover, we observed that the proline-rich domain was able to associate with and bundle F-actin at physiological ionic strength.

    Conclusion: The proline-rich domain is a functional structure playing a role in the association of tau with actin. This suggests that the proline-rich domain and the microtubule-binding domain of tau are both involved in binding to and bundling F-actin.

    BMC cell biology 2009;10;81

  • Tau fragmentation, aggregation and clearance: the dual role of lysosomal processing.

    Wang Y, Martinez-Vicente M, Krüger U, Kaushik S, Wong E, Mandelkow EM, Cuervo AM and Mandelkow E

    Max-Planck-Unit for Structural Molecular Biology, Notkestrasse 85, 22607 Hamburg, Germany.

    Aggregation and cleavage are two hallmarks of Tau pathology in Alzheimer disease (AD), and abnormal fragmentation of Tau is thought to contribute to the nucleation of Tau paired helical filaments. Clearance of the abnormally modified protein could occur by the ubiquitin-proteasome and autophagy-lysosomal pathways, the two major routes for protein degradation in cells. There is a debate on which of these pathways contributes to clearance of Tau protein and of the abnormal Tau aggregates formed in AD. Here, we demonstrate in an inducible neuronal cell model of tauopathy that the autophagy-lysosomal system contributes to both Tau fragmentation into pro-aggregating forms and to clearance of Tau aggregates. Inhibition of macroautophagy enhances Tau aggregation and cytotoxicity. The Tau repeat domain can be cleaved near the N terminus by a cytosolic protease to generate the fragment F1. Additional cleavage near the C terminus by the lysosomal protease cathepsin L is required to generate Tau fragments F2 and F3 that are highly amyloidogenic and capable of seeding the aggregation of Tau. We identify in this work that components of a selective form of autophagy, chaperone-mediated autophagy, are involved in the delivery of cytosolic Tau to lysosomes for this limited cleavage. However, F1 does not fully enter the lysosome but remains associated with the lysosomal membrane. Inefficient translocation of the Tau fragments across the lysosomal membrane seems to promote formation of Tau oligomers at the surface of these organelles which may act as precursors of aggregation and interfere with lysosomal functioning.

    Funded by: NIA NIH HHS: AG031782; NINDS NIH HHS: NS038370

    Human molecular genetics 2009;18;21;4153-70

  • The distinct cognitive syndromes of Parkinson's disease: 5 year follow-up of the CamPaIGN cohort.

    Williams-Gray CH, Evans JR, Goris A, Foltynie T, Ban M, Robbins TW, Brayne C, Kolachana BS, Weinberger DR, Sawcer SJ and Barker RA

    Cambridge Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge, CB2 0PY, UK. chm27@cam.ac.uk

    Cognitive abnormalities are common in Parkinson's disease, with important social and economic implications. Factors influencing their evolution remain unclear but are crucial to the development of targeted therapeutic strategies. We have investigated the development of cognitive impairment and dementia in Parkinson's disease using a longitudinal approach in a population-representative incident cohort (CamPaIGN study, n = 126) and here present the 5-year follow-up data from this study. Our previous work has implicated two genetic factors in the development of cognitive dysfunction in Parkinson's disease, namely the genes for catechol-O-methyltransferase (COMT Val(158)Met) and microtubule-associated protein tau (MAPT) H1/H2. Here, we have explored the influence of these genes in our incident cohort and an additional cross-sectional prevalent cohort (n = 386), and investigated the effect of MAPT H1/H2 haplotypes on tau transcription in post-mortem brain samples from patients with Lewy body disease and controls. Seventeen percent of incident patients developed dementia over 5 years [incidence 38.7 (23.9-59.3) per 1000 person-years]. We have demonstrated that three baseline measures, namely, age >or=72 years, semantic fluency less than 20 words in 90 s and inability to copy an intersecting pentagons figure, are significant predictors of dementia risk, thus validating our previous findings. In combination, these factors had an odds ratio of 88 for dementia within the first 5 years from diagnosis and may reflect the syndrome of mild cognitive impairment of Parkinson's disease. Phonemic fluency and other frontally based tasks were not associated with dementia risk. MAPT H1/H1 genotype was an independent predictor of dementia risk (odds ratio = 12.1) and the H1 versus H2 haplotype was associated with a 20% increase in transcription of 4-repeat tau in Lewy body disease brains. In contrast, COMT genotype had no effect on dementia, but a significant impact on Tower of London performance, a frontostriatally based executive task, which was dynamic, such that the ability to solve this task changed with disease progression. Hence, we have identified three highly informative predictors of dementia in Parkinson's disease, which can be easily translated into the clinic, and established that MAPT H1/H1 genotype is an important risk factor with functional effects on tau transcription. Our work suggests that the dementing process in Parkinson's disease is predictable and related to tau while frontal-executive dysfunction evolves independently with a more dopaminergic basis and better prognosis.

    Funded by: Medical Research Council: RG38582

    Brain : a journal of neurology 2009;132;Pt 11;2958-69

  • [Clinical, pathological, and genetic characteristics of frontotemporal dementia and parkinsonism linked to chromosome 17 with mutations in the MAPT and PGRN].

    Tsuboi Y

    Department of Neurology, Fukuoka University, 7-45-1 Nanakuma, Johnan-ku, Fukuoka, 814-0180, Japan.

    We reviewed the clinical, neuropathological, and genetic findings in patients with frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) with mutations in microtubule-associated protein tau (MAPT) and progranulin (PGRN). Research on FTDP-17 has greatly progressed over the years. Clinically, FTDP-17 is clinically characterized by autosomal dominant frontotemporal dementia, with or without parkinsonism. Two pathological variants of FTDP-17 are seen: one characterized by tau aggregation in neurons and glial cells, and the other, by ubiquitin-positive inclusions in neurons. Mutations in the MAPT gene have been identified as a cause of familial tau-positive FTDP-17 (MAPT), whereas mutations in the gene encoding PGRN, which is located 1.7 Mb from the MAPT gene on chromosome 17, have been identified in familial ubiquitin-positive FTDP-17 (PGRN). Recent studies have identified 44 different mutations in more than 100 families with FTDP-17 (MAPT), and 66 different mutations in more than 100 families with FTDP-17 (PGRN). Although cases of FTDP-17 have been reported worldwide, FTDP-17 (PGRN) has not yet been seen in Japan. The discovery of monogenic forms of neurodegenerative diseases is important for understanding the pathogenesis of these diseases. The findings of future research may facilitate the understanding of the causes of FTDP, and further improve diagnostic tools and help develop novel preventive methods and treatments for not only the genetic but also the sporadic form of neurodegenerative disorders.

    Brain and nerve = Shinkei kenkyu no shinpo 2009;61;11;1285-91

  • CSF biomarkers predict rate of cognitive decline in Alzheimer disease.

    Kester MI, van der Vlies AE, Blankenstein MA, Pijnenburg YA, van Elk EJ, Scheltens P and van der Flier WM

    Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.

    Objective: CSF biomarkers amyloid beta 1-42 (Abeta(42)), total tau (tau), and tau phosphorylated at threonine 181 (p-tau-181) are useful diagnostic markers for Alzheimer disease (AD). Less is known about these biomarkers as predictors for further cognitive decline in patients with AD. We hypothesized that high tau, especially in combination with relatively low p-tau-181, is a marker of rapid decline, since it has been associated with fast neuronal degeneration.

    Methods: A total of 151 patients with AD of whom we had baseline CSF were included from our memory clinic. All patients had at least 2 Mini-Mental State Examination (MMSE) scores, obtained no less than 1 year apart. Linear mixed models were used to assess associations between CSF biomarkers and the rate of cognitive decline as measured with the MMSE. CSF biomarkers were used in quintiles, random intercept and random slope with time were assumed, and the analyses were corrected for sex and age.

    Results: The patients with AD (45% women, age 66 +/- 9 years, baseline MMSE 22 +/- 4) had a follow-up period of 2.0 (1.0-5.0) years. Linear mixed models revealed no relations between any CSF biomarker and baseline MMSE. However, CSF biomarkers did predict cognitive decline over time. A low p-tau-181/tau ratio was the strongest predictor with a dose-dependent effect (lowest vs highest quintile: 2.9 vs 1.3 MMSE points annual decline, p for trend <0.001). In addition, low Abeta(42), high tau, and high tau/Abeta(42)-ratio were associated with rapid cognitive decline (p < 0.05).

    Conclusion: At the time of diagnosis, a combination of high CSF tau without proportionally elevated p-tau-181 is associated with a faster rate of cognitive decline.

    Neurology 2009;73;17;1353-8

  • Microtubule-associated protein tau in human prostate cancer cells: isoforms, phosphorylation, and interactions.

    Souter S and Lee G

    Program in Molecular and Cellular Biology, Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.

    Tau is a microtubule-associated protein whose function has been investigated primarily in neurons. Recently, tau expression has been correlated with increased drug resistance in various cancers of non-neuronal tissues. In this report, we investigate the tau expressed in cancerous prostate lines ALVA-31, DU 145, and PC-3. Prostate cancer tau is heat-stable and highly phosphorylated, containing many of the modifications identified in Alzheimer's disease brain tau. RT-PCR and phosphatase treatment indicated that all six alternatively spliced adult brain tau isoforms are expressed in ALVA-31 cells, and isoforms containing exon 6 as well as high molecular weight tau isoforms containing either exon 4A or a larger splice variant of exon 4A are also present. Consistent with its hyperphosphorylated state, a large proportion of ALVA-31 tau does not bind to microtubules, as detected by confocal microscopy and biochemical tests. Finally, endogenous ALVA-31 tau can interact with the p85 subunit of phosphatidylinositol 3-kinase, as demonstrated by co-immunoprecipitations and in vitro protein-binding assays. Our results suggest that tau in prostate cancer cells does not resemble that from normal adult brain and support the hypothesis that tau is a multifunctional protein.

    Funded by: NCI NIH HHS: CA103672, P20 CA103672; NIA NIH HHS: R21 AG031562

    Journal of cellular biochemistry 2009;108;3;555-64

  • AAV-tau mediates pyramidal neurodegeneration by cell-cycle re-entry without neurofibrillary tangle formation in wild-type mice.

    Jaworski T, Dewachter I, Lechat B, Croes S, Termont A, Demedts D, Borghgraef P, Devijver H, Filipkowski RK, Kaczmarek L, Kügler S and Van Leuven F

    Experimental Genetics Group, Department of Human Genetics, KULeuven-Campus, Leuven, Belgium.

    In Alzheimer's disease tauopathy is considered secondary to amyloid, and the duality obscures their relation and the definition of their respective contributions.Transgenic mouse models do not resolve this problem conclusively, i.e. the relative hierarchy of amyloid and tau pathology depends on the actual model and the genes expressed or inactivated. Here, we approached the problem in non-transgenic models by intracerebral injection of adeno-associated viral vectors to express protein tau or amyloid precursor protein in the hippocampus in vivo. AAV-APP mutant caused neuronal accumulation of amyloid peptides, and eventually amyloid plaques at 6 months post-injection, but with only marginal hippocampal cell-death. In contrast, AAV-Tau, either wild-type or mutant P301L, provoked dramatic degeneration of pyramidal neurons in CA1/2 and cortex within weeks. Tau-mediated neurodegeneration proceeded without formation of large fibrillar tau-aggregates or tangles, but with increased expression of cell-cycle markers.We present novel AAV-based models, which demonstrate that protein tau mediates pyramidal neurodegeneration in vivo. The data firmly support the unifying hypothesis that post-mitotic neurons are forced to re-enter the cell-cycle in primary and secondary tauopathies, including Alzheimer's disease.

    PloS one 2009;4;10;e7280

  • The effect of age and the H1c MAPT haplotype on MAPT expression in human brain.

    Hayesmoore JB, Bray NJ, Cross WC, Owen MJ, O'Donovan MC and Morris HR

    Neuropsychiatric Genetics Group, Cardiff University School of Medicine, Cardiff, UK.

    The MAPT H1c haplotype is a risk factor for the neurodegenerative tauopathies progressive supranuclear palsy (PSP) and Alzheimer's disease. We hypothesise that the effect of the H1c haplotype relates to an increase in MAPT expression leading to an increase in tau neurofibrillary tangle deposition. We have evaluated the effect of the MAPT H1c haplotype on the expression of MAPT using allele specific expression, comparing the relative levels of MAPT H1 and H2 RNA derived from post-mortem human brain, unaffected by neurodegenerative disease. Using three assays spanning the MAPT gene we did not detect any effect of H1c on MAPT expression as compared with other haplotypes. We did, however, detect an effect of age on expression of MAPT H1 with a relative decrease in MAPT H1 expression with increased age. Our data suggest that there is an interaction between age and the expression of MAPT.

    Funded by: Medical Research Council: G0700943

    Neurobiology of aging 2009;30;10;1652-6

  • Differential effect of three-repeat and four-repeat tau on mitochondrial axonal transport.

    Stoothoff W, Jones PB, Spires-Jones TL, Joyner D, Chhabra E, Bercury K, Fan Z, Xie H, Bacskai B, Edd J, Irimia D and Hyman BT

    MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.

    Tau protein is present in six different splice forms in the human brain and interacts with microtubules via either 3 or 4 microtubule binding repeats. An increased ratio of 3 repeat to 4 repeat isoforms is associated with neurodegeneration in inherited forms of frontotemporal dementia. Tau over-expression diminishes axonal transport in several systems, but differential effects of 3 repeat and 4 repeat isoforms have not been studied. We examined the effects of tau on mitochondrial transport and found that both 3 repeat and 4 repeat tau change normal mitochondrial distribution within the cell body and reduce mitochondrial localization to axons; 4 repeat tau has a greater effect than 3 repeat tau. Further, we observed that the 3 repeat and 4 repeat tau cause different alterations in retrograde and anterograde transport dynamics with 3 repeat tau having a slightly stronger effect on axon transport dynamics. Our results indicate that tau-induced changes in axonal transport may be an underlying theme in neurodegenerative diseases associated with isoform specific changes in tau's interaction with microtubules.

    Funded by: NIA NIH HHS: 1 R01 AG 026249, 2P50 AG05134, K99 AG033670, K99 AG033670-01A1, P50 AG005134, P50 AG005134-140021, P50 AG005134-210027, P50 AG005134-268383, R01 AG008487, R01 AG008487-18S1, R01 AG026249; NIBIB NIH HHS: EB00768, P41 EB002503, R01 EB000768

    Journal of neurochemistry 2009;111;2;417-27

  • Pattern of tau isoforms expression during development in vivo.

    Bullmann T, Holzer M, Mori H and Arendt T

    Paul Flechsig Institute of Brain Research, Department of Cellular and Molecular Mechanisms of Neurodegeneration, University of Leipzig, Jahnallee 59, 04019 Leipzig, Germany.

    Neuronal morphology and axonal growth during development are correlated to specific expression of various microtubule-associated protein tau isoforms. Using RT-PCR and Western blotting we found the unexpected result that the shift from fetal towards adult isoforms does not differ between rat cerebral cortex and cerebellum, two temporally differently developing areas. By immunohistochemistry we observed a cell type specific isoform expression during development and adulthood. The developmental expression of tau isoforms was compared to the appearance of stable microtubules assessed by the immunohistochemical detection of tubulin modifications. The tau isoform shift shows an apparent disconnect to neurogenesis, migration and volume growth, but coincides with the formation of synapses and the appearance of stable microtubules.

    International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience 2009;27;6;591-7

  • Phosphorylation of soluble tau differs in Pick's disease and Alzheimer's disease brains.

    van Eersel J, Bi M, Ke YD, Hodges JR, Xuereb JH, Gregory GC, Halliday GM, Götz J, Kril JJ and Ittner LM

    Discipline of Pathology, The University of Sydney, Sydney, NSW, 2006, Australia.

    Frontotemporal lobar degeneration (FTLD) is a common cause of presenile dementia characterised by behavioural and language disturbances. Pick's disease (PiD) is a subtype of FTLD, which presents with intraneuronal inclusions consisting of hyperphosphorylated tau protein aggregates. Although Alzheimer's disease (AD) is also characterised by tau lesions, these are both histologically and biochemically distinct from the tau aggregates found in PiD. What determines the distinct characteristics of these tau lesions is unknown. As phosphorylated, soluble tau has been suggested to be the precursor of tau aggregates, we compared both the level and phosphorylation profile of tau in tissue extracts of AD and PiD brains to determine whether the differences in the tau lesions are reflected by differences in soluble tau. Levels of soluble tau were decreased in AD but not PiD. In addition, soluble tau was phosphorylated to a greater extent in AD than in PiD and displayed a different phosphorylation profile in the two disorders. Consistently, tau kinases were activated to different degrees in AD compared with PiD. Such differences in solubility and phosphorylation may contribute, at least in part, to the formation of distinct tau deposits, but may also have implications for the clinical differences between AD and PiD.

    Journal of neural transmission (Vienna, Austria : 1996) 2009;116;10;1243-51

  • Recent origin and spread of a common Welsh MAPT splice mutation causing frontotemporal lobar degeneration.

    Colombo R, Tavian D, Baker MC, Richardson AM, Snowden JS, Neary D, Mann DM and Pickering-Brown SM

    Laboratory of Human Molecular Biology and Genetics, Catholic University of the Sacred Heart, Piazza Buonarroti 30, 20145, Milan, Italy. roberto.colombo@unicatt.it

    IVS10+16C>T is the most prevalent mutation in the microtubule-associated protein tau gene (MAPT) causing frontotemporal lobar degeneration (FTLD) in populations of British descent. A highly conserved 17q21 haplotype was identified in IVS10+16C>T chromosomes from North Wales, Greater Manchester and the London areas of the UK, Australia, and the USA, suggesting the occurrence of a common founder effect. To test this hypothesis, the age of the mutation was estimated by parametric and Bayesian analysis of linkage disequilibrium's decay over generations, and the results were compared with historical and geographical data on FTLD families. The inferred age (23 generations; 95% confidence interval, 9-74 generations) dates the most recent common ancestor of IVS10+16C>T chromosomes before Welsh people started emigrating to the USA and Australia, where they introduced the mutation. The identification of a cohort of FTLD families with a homogeneous genetic background within and around the MAPT locus will further the investigation of the different clinical and pathological presentations of patients with identical MAPT mutations.

    Funded by: Medical Research Council: G0701441

    Neurogenetics 2009;10;4;313-8

  • Atrophy patterns in IVS10+16, IVS10+3, N279K, S305N, P301L, and V337M MAPT mutations.

    Whitwell JL, Jack CR, Boeve BF, Senjem ML, Baker M, Ivnik RJ, Knopman DS, Wszolek ZK, Petersen RC, Rademakers R and Josephs KA

    Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA.

    Objective: To use a case-control study to assess and compare patterns of gray matter loss across groups of subjects with different mutations in the microtubule-associated protein tau (MAPT) gene.

    Methods: We identified all subjects from Mayo Clinic, Rochester, Minnesota, that screened positive for mutations in MAPT and had a head MRI (n = 22). Voxel-based morphometry was used to assess patterns of gray matter atrophy in groups of subjects with the IVS10+16, IVS10+3, N279K, S305N, P301L, and V337M mutations compared with age- and sex-matched controls.

    Results: All MAPT groups showed gray matter loss in the anterior temporal lobes, with varying degrees of involvement of the frontal and parietal lobes. Within the temporal lobe, the subjects with IVS10+16, IVS10+3, N279K, and S305N mutations (mutations that influence the alternative splicing of tau pre-messenger RNA) all showed gray matter loss focused on the medial temporal lobes. In contrast to these groups, the subjects with P301L or V337M mutations (mutations that affect the structure of the tau protein) both showed gray matter loss focused on the lateral temporal lobes, with a relative sparing of the medial temporal lobe.

    Conclusion: There seem to be differences in patterns of temporal lobe atrophy across the MAPT mutations, which may aid in the differentiation of the different mutation carriers. Furthermore, there seems to be a possible association between mutation function and pattern of temporal lobe atrophy.

    Funded by: NCRR NIH HHS: C06 RR018898

    Neurology 2009;73;13;1058-65

  • Baseline CSF p-tau levels independently predict progression of hippocampal atrophy in Alzheimer disease.

    Henneman WJ, Vrenken H, Barnes J, Sluimer IC, Verwey NA, Blankenstein MA, Klein M, Fox NC, Scheltens P, Barkhof F and van der Flier WM

    Department of Radiology and Alzheimer Center, VU University Medical Center, 1007 MB Amsterdam, The Netherlands. w.henneman@vumc.nl

    Objective: To investigate whether baseline CSF biomarkers are associated with hippocampal atrophy rate as a measure of disease progression in patients with Alzheimer disease (AD), patients with mild cognitive impairment (MCI), and controls, controlling for baseline neuropsychological and MRI findings.

    Methods: We assessed data from 31 patients with AD, 25 patients with MCI, and 19 controls (mean age 68 +/- 8 years; 39 [52%] female) who visited our memory clinic and had received serial MRI scanning (scan interval 1.7 +/- 0.7 years). At baseline, CSF biomarkers (amyloid beta 1-42, tau, and tau phosphorylated at threonine 181 [p-tau]) were obtained, as well as neuropsychological data. Baseline MRI scans were assessed using visual rating scales for medial temporal lobe atrophy (MTA), global cortical atrophy, and white matter hyperintensities. Hippocampal atrophy rates were estimated using regional nonlinear "fluid" registration of follow-up scan to baseline scan.

    Results: Stepwise multiple linear regression, adjusted for age and sex, showed that increased CSF p-tau levels (beta [standard error]: -0.79 [0.35]) at baseline was independently associated with higher subsequent hippocampal atrophy rates (p < 0.05), together with poorer memory performance (0.09 [0.04]) and more severe MTA (-0.60 [0.21]). The association of memory function with hippocampal atrophy rate was explained by the link with diagnosis, because it disappeared from the model after we additionally corrected for diagnosis.

    Conclusions: Baseline CSF levels of tau phosphorylated at threonine 181 are independently associated with subsequent disease progression, as reflected by hippocampal atrophy rate. This effect is independent of baseline neuropsychological and MRI predictors. Our results imply that predicting disease progression can best be achieved by combining information from different modalities.

    Funded by: Medical Research Council: G0601846, G0801306; NIA NIH HHS: U01 AG024904

    Neurology 2009;73;12;935-40

  • Evaluation of microtubule-associated protein-Tau expression as a prognostic and predictive marker in the NSABP-B 28 randomized clinical trial.

    Pusztai L, Jeong JH, Gong Y, Ross JS, Kim C, Paik S, Rouzier R, Andre F, Hortobagyi GN, Wolmark N and Symmans WF

    Department of Breast Medical Oncology, The University of Texas M. D. Anderson Cancer Center, PO Box 301439, Houston, TX 77230-1439, USA. lpusztai@mdanderson.org

    Purpose: We assessed Tau protein expression in primary breast cancer specimens of patients included in the National Surgical Breast and Bowel Project (NSABP) -B 28 clinical trial. Expression levels were correlated with disease-free survival (DFS) and overall survival (OS). Interaction between this marker and paclitaxel efficacy was also examined.

    Methods: Tissue microarrays were available for 1,942 patients (63% of all trial participants) who were randomly assigned to receive either four courses of doxorubicin and cyclophosphamide (AC) or AC followed by four courses of adjuvant paclitaxel chemotherapy. All patients who were hormone receptor positive received adjuvant endocrine therapy. Immunohistochemistry was used to measure Tau expression at M. D. Anderson Cancer Center blinded to clinical outcome. Correlation between Tau and OS and DFS was performed by the NSABP Biostatistical Center.

    Results: Forty-three percent of patients were Tau positive. Tau positivity correlated with estrogen receptor (ER) -positive status (P < .0001), lower histologic grade (P < .001), and lack of human epidermal growth factor receptor 2 (HER2) expression (P < .0001). In univariate analyses, Tau- and ER-positive status were both associated with better DFS and OS (P < .0001) whereas greater tumor size, high grade, lymph node- and HER2-positive status were each associated with worse DFS and OS (P < .0001). In multivariate analysis, the same variables except HER2 remained significant. There was no significant interaction between Tau expression and benefit from paclitaxel in the total population or among ER-positive or -negative patients.

    Conclusion: High Tau protein expression is associated with better prognosis in patients treated with adjuvant anthracycline and paclitaxel chemotherapy and endocrine therapy, but there was no significant interaction between Tau expression and paclitaxel benefit.

    Funded by: NCI NIH HHS: U10 CA012027, U10 CA037377, U10 CA069651, U10 CA069974, U10-CA-12027, U10-CA-37377, U10-CA-69651, U10-CA-69974, U24 CA114732, U24-CA-114732

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2009;27;26;4287-92

  • Phosphorylation of more than one site is required for tight interaction of human tau protein with 14-3-3zeta.

    Sluchanko NN, Seit-Nebi AS and Gusev NB

    Department of Biochemistry, School of Biology, M.V. Lomonosov Moscow State University, Moscow, Russian Federation.

    Serine residues phosphorylated by protein kinase A (PKA) in the shortest isoform of human tau protein (tau3) were sequentially replaced by alanine and interaction of phosphorylated tau3 and its mutants with 14-3-3 was investigated. Mutation S156A slightly decreased interaction of phosphorylated tau3 with 14-3-3. Double mutations S156A/S267A and especially S156A/S235A, strongly inhibited interaction of phosphorylated tau3 with 14-3-3. Thus, two sites located in the Pro-rich region and in the pseudo repeats of tau3 are involved in phosphorylation-dependent interaction of tau3 with 14-3-3. The state of tau3 phosphorylation affects the mode of 14-3-3 binding and by this means might modify tau filament formation.

    FEBS letters 2009;583;17;2739-42

  • Correction of tau mis-splicing caused by FTDP-17 MAPT mutations by spliceosome-mediated RNA trans-splicing.

    Rodriguez-Martin T, Anthony K, Garcia-Blanco MA, Mansfield SG, Anderton BH and Gallo JM

    Department of Clinical Neuroscience, MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, London SE5 8AF, UK.

    Frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) is caused by mutations in the MAPT gene, encoding the tau protein that accumulates in intraneuronal lesions in a number of neurodegenerative diseases. Several FTDP-17 mutations affect alternative splicing and result in excess exon 10 (E10) inclusion in tau mRNA. RNA reprogramming using spliceosome-mediated RNA trans-splicing (SMaRT) could be a method of choice to correct aberrant E10 splicing resulting from FTDP-17 mutations. SMaRT creates a hybrid mRNA through a trans-splicing reaction between an endogenous target pre-mRNA and a pre-trans-splicing RNA molecule (PTM). However, FTDP-17 mutations affect the strength of cis-splicing elements and could favor cis-splicing over trans-splicing. Excess E10 inclusion in FTDP-17 can be caused by intronic mutations destabilizing a stem-loop protecting the 5' splice site at the E10/intron 10 junction. COS cells transfected with a minigene containing the intronic +14 mutation produce exclusively E10(+) RNA. Generation of E10(-) RNA was restored after co-transfection with a PTM designed to exclude E10. Similar results were obtained with a target containing the exonic N279K mutation which strengthens a splicing enhancer within E10. Conversely, increase or decrease in E10 content was achieved by trans-splicing from a target carrying the Delta280K mutation, which weakens the same splicing enhancer. Thus E10 inclusion can be modulated by trans-splicing irrespective of the strength of the cis-splicing elements affected by FTDP-17 mutations. In conclusion, RNA trans-splicing could provide the basis of therapeutic strategies for impaired alternative splicing caused by pathogenic mutations in cis-acting splicing elements.

    Funded by: Biotechnology and Biological Sciences Research Council: BBS/B/03173; Medical Research Council; Wellcome Trust

    Human molecular genetics 2009;18;17;3266-73

  • Association of MAPT haplotype-tagging SNPs with sporadic Parkinson's disease.

    Vandrovcova J, Pittman AM, Malzer E, Abou-Sleiman PM, Lees AJ, Wood NW and de Silva R

    Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK.

    Mutations in the tau gene (MAPT) have been found in families with frontotemporal dementia with parkinsonism linked to chromosome 17. In addition, the MAPT H1-clade specific sub-haplotype, H1c, has been strongly associated with the tauopathies, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) and, to a lesser extent, with Alzheimer's disease (AD). In Parkinson's disease (PD), there have been several reports of association with the MAPT H1-clade. Although weak to inconclusive, this association is supported by meta-analyses of the various studies. To further investigate this baffling role of MAPT in PD, six haplotype-tagging SNPs were genotyped in a large cohort of sporadic PD cases; 324 pathologically confirmed and 248 clinically diagnosed, and 660 controls. In the single-locus association analysis, the H1-clade was associated with an increased risk of PD (p=0.032). In the haplotype-analysis, the sole H2-derived haplotype was under-represented in all of the PD cases compared to controls (p=0.03). There was no significant difference in the distribution of any of the common haplotypes derived from the H1-clade background. Our study supports the hypothesis that genetic variability in the MAPT gene confers susceptibility to PD. However, the effect is not strong, and the H1c haplotype is not involved, suggesting a mechanism that is distinct to that involved in the associated tauopathies and may be explained by the H1/H2 inversion.

    Funded by: Medical Research Council: G0400017, G0400074, G0501560, G0501560(76517), G0502157, G0900652

    Neurobiology of aging 2009;30;9;1477-82

  • Dopamine D1 receptor activation induces tau phosphorylation via cdk5 and GSK3 signaling pathways.

    Lebel M, Patenaude C, Allyson J, Massicotte G and Cyr M

    Department of Chemistry-Biology, Medical Biology Section, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada.

    Increasing evidence is demonstrating that drugs affecting dopamine levels in the brain induce cytoskeletal modifications. These evolving changes may impact neuronal synaptic plasticity as cytoskeletal constituents are involved in the maintenance of dendritic processes, and any alterations in their stability could influence major cellular compartments of neurons, such as dendrites, spines and synapses. Here, we describe a molecular chain of events that links dopamine D1 receptor activation to hyperphosphorylation of the microtubule-associated protein tau, which is normally involved in microtubules stabilization. We show, in SK-N-MC cells and rat striatal sections, that phosphorylation of tau at serines 199-202 and 214 appears to be mediated through activation of calcium-dependent intracellular mechanism, subsequent to D1 receptor-induced cAMP-dependent protein kinase A (PKA). We demonstrate, using pharmacological tools, that PKA activation causes increase of calcium levels, leading to cyclin-dependent kinase 5 activation by calpain proteolysis of p35 to p25 and glycogen synthase kinase 3beta activation by its phosphorylation at tyrosine 216. The D2 receptor agonism or lowering cAMP levels has no effect in our experimental settings. Moreover, we do not observe any association between phosphorylated tau and cellular damage. These data unravel novel mechanisms of tau hyperphosphorylation during G-protein-coupled receptor activation and are the first to show that stimulation of D1 receptors could have a profound influence on the neuronal cytoskeletal constituent tau.

    Neuropharmacology 2009;57;4;392-402

  • Improved discrimination of autopsy-confirmed Alzheimer's disease (AD) from non-AD dementias using CSF P-tau(181P).

    Koopman K, Le Bastard N, Martin JJ, Nagels G, De Deyn PP and Engelborghs S

    Department of Neurology and Memory Clinic, Middelheim General Hospital (ZNA), Antwerp, Belgium; Department of Neurology, University Medical Center Groningen, Groningen, The Netherlands.

    To establish diagnostic accuracy (acc) and optimal cut-off levels of CSF tau phosphorylated at threonine 181 (P-tau(181P)) for discriminating Alzheimer's disease (AD) from non-AD dementias in autopsy-confirmed dementia patients, CSF levels of beta-amyloid peptide (Abeta(1-42)), total tau protein (T-tau) and P-tau(181P) from patients with definite AD (n=95) and non-AD dementias (n=50) were determined with single-parameter ELISA kits. Optimal P-tau(181P) cut-off levels for differentiating AD from pooled non-AD dementias, dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) were 50.4pg/mL (acc=0.73), 52.8pg/mL (acc=0.73) and 35.3pg/mL (acc=0.90), respectively. The optimal CSF P-tau(181P) cut-off level for discriminating AD from non-AD dementias was 50.4pg/mL. Optimal CSF P-tau(181P) cut-off levels differed between non-AD diagnostic dementia categories.

    Neurochemistry international 2009;55;4;214-8

  • Recurrent rearrangements in synaptic and neurodevelopmental genes and shared biologic pathways in schizophrenia, autism, and mental retardation.

    Guilmatre A, Dubourg C, Mosca AL, Legallic S, Goldenberg A, Drouin-Garraud V, Layet V, Rosier A, Briault S, Bonnet-Brilhault F, Laumonnier F, Odent S, Le Vacon G, Joly-Helas G, David V, Bendavid C, Pinoit JM, Henry C, Impallomeni C, Germano E, Tortorella G, Di Rosa G, Barthelemy C, Andres C, Faivre L, Frébourg T, Saugier Veber P and Campion D

    Institut National de la Santé et de la Recherche Médicale, Unité 614, Institut Hospitalo-Universitaire de Recherche Biomédicale, 76000 Rouen, France.

    Context: Results of comparative genomic hybridization studies have suggested that rare copy number variations (CNVs) at numerous loci are involved in the cause of mental retardation, autism spectrum disorders, and schizophrenia.

    Objectives: To provide an estimate of the collective frequency of a set of recurrent or overlapping CNVs in 3 different groups of cases compared with healthy control subjects and to assess whether each CNV is present in more than 1 clinical category.

    Design: Case-control study.

    Setting: Academic research.

    Participants: We investigated 28 candidate loci previously identified by comparative genomic hybridization studies for gene dosage alteration in 247 cases with mental retardation, in 260 cases with autism spectrum disorders, in 236 cases with schizophrenia or schizoaffective disorder, and in 236 controls.

    Collective and individual frequencies of the analyzed CNVs in cases compared with controls.

    Results: Recurrent or overlapping CNVs were found in cases at 39.3% of the selected loci. The collective frequency of CNVs at these loci is significantly increased in cases with autism, in cases with schizophrenia, and in cases with mental retardation compared with controls (P < .001, P = .01, and P = .001, respectively, Fisher exact test). Individual significance (P = .02 without correction for multiple testing) was reached for the association between autism and a 350-kilobase deletion located at 22q11 and spanning the PRODH and DGCR6 genes.

    Conclusions: Weakly to moderately recurrent CNVs (transmitted or occurring de novo) seem to be causative or contributory factors for these diseases. Most of these CNVs (which contain genes involved in neurotransmission or in synapse formation and maintenance) are present in the 3 pathologic conditions (schizophrenia, autism, and mental retardation), supporting the existence of shared biologic pathways in these neurodevelopmental disorders.

    Archives of general psychiatry 2009;66;9;947-56

  • Microtubule-associated protein tau (MAPT) influences the risk of Parkinson's disease among Indians.

    Das G, Misra AK, Das SK, Ray K and Ray J

    S. N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700 019, India.

    Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system and its prevalence increases with age. Microtubule-associated protein tau (MAPT), a neuronal protein is involved in the pathogenesis of several neurodegenerative diseases including PD. To determine the broader significance of this association with PD, replicative studies in distinct ethnic populations are required. In this study, we investigated MAPT for its potential association with PD using five haplotype-tagging SNPs and the del-In9 polymorphism of MAPT in 301 PD patients and 243 healthy controls from eastern India. Our case-control analysis did not show a significant association with any of the markers and PD. However, a risk haplotype [GAC+G] for PD was identified (OR=1.563; 95% CI=1.045-2.337; p=0.03). In addition, haplotype AAC+A (OR=2.787; 95% CI=1.372-5.655; p=0.004) was strongly associated with early onset PD (age at onset < or =40 years) and AAC+G haplotype showed a weak association (OR=2.233; 95% CI=1.018-4.895; p=0.045) with late onset PD (age at onset >40 years). This observation highlights the significance of rs7521 in modifying the age at onset of PD under a common haplotype background. We also identified AGC+A as a risk haplotype for sporadic cases (OR=2.773, 95% CI=1.198-6.407, p=0.016). This is the first association study from India conducted on MAPT among PD patients and provides valuable information for comparison with other ethnic groups.

    Neuroscience letters 2009;460;1;16-20

  • Co-localization of hyperphosphorylated tau and caspases in the brainstem of Alzheimer's disease patients.

    Wai MS, Liang Y, Shi C, Cho EY, Kung HF and Yew DT

    Department of Anatomy, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.

    Hyperphosphorylation of microtubule associated protein tau had limited studies in Alzheimer's disease (AD) brainstem. We compared the distribution and number of neurons with hyperphosphorylated tau in two age groups of AD brainstems with mean ages of 65.4 +/- 5.7 and 91.1 +/- 6.4 years. The degree of co-localization of hyperphosphorylated tau positive cells with either cleaved caspase-3 or cleaved caspase-6 was also quantified. Results showed hyperphosphorylated tau mainly occurred in hypoglossal, dorsal motor vagal, trigeminal sensory/motor nuclei as well as in dorsal raphe, locus coeruleus and substantia nigra. Older AD brainstem consistently had higher density of hyperphosphorylated tau cells. Up to 70% of tau positive cells also displayed either cleaved caspase-3 or caspase-6, and the number of co-localized tau cells in each caspase subfamily group was always higher in older aged group. Some hyperphosphorylated tau cells with cleaved caspases had TUNEL positive nuclei. These findings suggest that these latter cells went through the apoptotic process or DNA fragmentation.

    Biogerontology 2009;10;4;457-69

  • D-Ribosylated Tau forms globular aggregates with high cytotoxicity.

    Chen L, Wei Y, Wang X and He R

    State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, 100101 Beijing, China.

    Although the glycation of Tau that is involved in paired helical filament formation in Alzheimer's disease has been widely studied, little attention has been paid to the role of D-ribose in the glycation of Tau. Here, we show that Tau is rapidly glycated in the presence of D-ribose, resulting in oligomerization and polymerization. Glycated derivatives appeared after 24 h incubation. Western blotting indicated the formation of advanced glycation end-products (AGEs) during initial stages of glycation. Thioflavin T-positive (ThT-positive) aggregations that appeared from day 4 indicated the globular-like features. Atomic force microscopy revealed that the surface morphology of ribosylated Tau40 was globular-like. Kinetic studies suggested that D-ribosylated Tau is slowly oligomerized and rapidly polymerized with ThT-positive features. Moreover, D-ribosylated Tau aggregates were highly toxic to SHSY5Y cells and resulted in both apoptosis and necrosis. This work has demonstrated that D-ribose reacted with Tau protein rapidly, producing ThT-positive aggregations which had high cytotoxicity.

    Cellular and molecular life sciences : CMLS 2009;66;15;2559-71

  • Inhibition of tau fibrillization by oleocanthal via reaction with the amino groups of tau.

    Li W, Sperry JB, Crowe A, Trojanowski JQ, Smith AB and Lee VM

    Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 94305, USA.

    Tau is a microtubule-associated protein that promotes microtubule assembly and stability. In Alzheimer's disease and related tauopathies, tau fibrillizes and aggregates into neurofibrillary tangles. Recently, oleocanthal isolated from extra virgin olive oil was found to display non-steroidal anti-inflammatory activity similar to ibuprofen. As our unpublished data indicates an inhibitory effect of oleocanthal on amyloid beta peptide fibrillization, we reasoned that it might inhibit tau fibrillization as well. Herein, we demonstrate that oleocanthal abrogates fibrillization of tau by locking tau into the naturally unfolded state. Using PHF6 consisting of the amino acid residues VQIVYK, a hexapeptide within the third repeat of tau that is essential for fibrillization, we show that oleocanthal forms an adduct with the lysine via initial Schiff base formation. Structure and function studies demonstrate that the two aldehyde groups of oleocanthal are required for the inhibitory activity. These two aldehyde groups show certain specificity when titrated with free lysine and oleocanthal does not significantly affect the normal function of tau. These findings provide a potential scheme for the development of novel therapies for neurodegenerative tauopathies.

    Funded by: NIA NIH HHS: AG17586, P01 AG017586, P01 AG017586-01, P01 AG017586-10

    Journal of neurochemistry 2009;110;4;1339-51

  • Inhibition of tau polymerization with a cyanine dye in two distinct model systems.

    Congdon EE, Figueroa YH, Wang L, Toneva G, Chang E, Kuret J, Conrad C and Duff KE

    Department of Pathology, Taub Institute, Columbia University and Department of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York 10032, USA.

    In a host of neurodegenerative diseases Tau, a microtubule-associated protein, aggregates into insoluble lesions within neurons. Previous studies have utilized cyanine dyes as Tau aggregation inhibitors in vitro. Herein we utilize cyanine dye 3,3'-diethyl-9-methyl-thiacarbocyanine iodide (C11) to modulate Tau polymerization in two model systems, an organotypic slice culture model derived from Tau transgenic mice and a split green fluorescent protein complementation assay in Tau-expressing cells. In slice cultures, submicromolar concentrations (0.001 microm) of C11 produced a significant reduction of aggregated Tau and a corresponding increase in unpolymerized Tau. In contrast, treatment with a 1 microm dose promoted aggregation of Tau. These results were recapitulated in the complementation assay where administration of 1 microm C11 produced a significant increase in polymerized Tau relative to control, whereas treatment of cells with 0.01 microm C11 resulted in a marked reduction of aggregated Tau. In the organotypic slice cultures, modulation of Tau aggregation was independent of changes in phosphorylation at disease and microtubule binding relevant epitopes for both dosing regimes. Furthermore, treatment with 0.001 microm C11 resulted in a decrease in both total filament mass and number. There was no evidence of apoptosis or loss of synaptic integrity at either dose, however, whereas submicromolar concentrations of C11 did not interfere with microtubule binding, higher doses resulted in a decrease in the levels of microtubule-bound Tau. Overall, a cyanine dye can dissociate aggregated Tau in an ex vivo model of tauopathy with little toxicity and exploration of the use of these type of dyes as therapeutic agents is warranted.

    Funded by: NIA NIH HHS: AG14452, R01 AG014452; NINDS NIH HHS: NS047447, R01 NS047447

    The Journal of biological chemistry 2009;284;31;20830-9

  • Phosphorylated Tau interacts with c-Jun N-terminal kinase-interacting protein 1 (JIP1) in Alzheimer disease.

    Ittner LM, Ke YD and Götz J

    Alzheimer's and Parkinson's Disease Laboratory, Brain and Mind Research Institute, University of Sydney, Sydney, Camperdown, New South Wales 2050, Australia.

    In Alzheimer disease (AD) and frontotemporal dementia the microtubule-associated protein Tau becomes progressively hyperphosphorylated, eventually forming aggregates. However, how Tau dysfunction is associated with functional impairment is only partly understood, especially at early stages when Tau is mislocalized but has not yet formed aggregates. Impaired axonal transport has been proposed as a potential pathomechanism, based on cellular Tau models and Tau transgenic mice. We recently reported K369I mutant Tau transgenic K3 mice with axonal transport defects that suggested a cargo-selective impairment of kinesin-driven anterograde transport by Tau. Here, we show that kinesin motor complex formation is disturbed in the K3 mice. We show that under pathological conditions hyperphosphorylated Tau interacts with c-Jun N-terminal kinase- interacting protein 1 (JIP1), which is associated with the kinesin motor protein complex. As a result, transport of JIP1 into the axon is impaired, causing JIP1 to accumulate in the cell body. Because we found trapping of JIP1 and a pathological Tau/JIP1 interaction also in AD brain, this may have pathomechanistic implications in diseases with a Tau pathology. This is supported by JIP1 sequestration in the cell body of Tau-transfected primary neuronal cultures. The pathological Tau/JIP1 interaction requires phosphorylation of Tau, and Tau competes with the physiological binding of JIP1 to kinesin light chain. Because JIP1 is involved in regulating cargo binding to kinesin motors, our findings may, at least in part, explain how hyperphosphorylated Tau mediates impaired axonal transport in AD and frontotemporal dementia.

    The Journal of biological chemistry 2009;284;31;20909-16

  • Three-/four-repeat-dependent aggregation profile of tau microtubule-binding domain clarified by dynamic light scattering analysis.

    Sugino E, Nishiura C, Minoura K, In Y, Sumida M, Taniguchi T, Tomoo K and Ishida T

    Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.

    The analysis of the self-assembly mechanism of the tau microtubule-binding domain (MBD) could provide the information needed to develop an effective method for the inhibition of the tau filament formation because of its core region that forms the filament. The MBD domain in the living body consists of similar three or four 31- to 32-residue repeats, namely 3RMBD (R134) and 4RMBD (R1234), respectively. The filament formation of the MBD has been mainly investigated by fluorescence spectroscopy utilizing the beta-sheet structure-binding signal sensor thioflavin. This method observes the aggregation indirectly, and provides no information on the time-dependent change in aggregation size or volume. Thus, to determine the structure necessary for initiating MBD self-association, the dynamic light scattering (DLS) method was applied to the analysis of the aggregations of 3RMBD, 4RMBD and their component single repeats and shown to be a powerful tool for directly analyzing filament formation. DLS analysis clearly showed that the building unit for initiating the aggregation is the intermolecular R3-R3 disulfide-bonded dimer for 3RMBD and the intramolecular R2-R3 disulfide-bonded monomer for 4RMBD, and their aggregation processes under physiological condition differ from each other, which has not been clearly revealed by the conventional fluorescence method. The repeat-number-dependent aggregation model of MBD, together with the function of each repeat, reported in this paper should help to devise a method of preventing tau PHF formation.

    Biochemical and biophysical research communications 2009;385;2;236-40

  • Excitatory amino acid transporter 2 associates with phosphorylated tau and is localized in neurofibrillary tangles of tauopathic brains.

    Sasaki K, Shimura H, Itaya M, Tanaka R, Mori H, Mizuno Y, Kosik KS, Tanaka S and Hattori N

    Department of Neurology, Juntendo University, Urayasu Hospital, Tokyo, Japan.

    Phosphorylated tau (p-tau) is the principal component of neurofibrillary tangles, a pathological hallmark, and likely plays a neurotoxic role in tauopathies including Alzheimer's disease (AD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). We subjected brains from autopsy cases of AD, PSP, and CBD to a variety of immunohistochemical, immunoblotting, and pull-down assays. In this study, we show that excitatory amino acid transporter 2 (EAAT2) preferentially interacted with phosphorylated tau and was localized in neurofibrillary tangles in the brains of such patients. These results strongly indicate that EAAT2 acts in tauopathy-related neurodegeneration, and abnormalities in glutamate transport play an important role in the pathogenesis of tauopathies.

    FEBS letters 2009;583;13;2194-200

  • Gene expression of estrogen receptor, progesterone receptor and microtubule-associated protein Tau in high-risk early breast cancer: a quest for molecular predictors of treatment benefit in the context of a Hellenic Cooperative Oncology Group trial.

    Pentheroudakis G, Kalogeras KT, Wirtz RM, Grimani I, Zografos G, Gogas H, Stropp U, Pectasides D, Skarlos D, Hennig G, Samantas E, Bafaloukos D, Papakostas P, Kalofonos HP, Pavlidis N and Fountzilas G

    Department of Medical Oncology, Ioannina University Hospital, Ioannina, Greece. gpenther@otenet.gr

    Background: Estrogen receptor (ER) and progesterone receptor (PgR) protein expression carry weak prognostic and moderate predictive utility for the outcome of early breast cancer patients on adjuvant chemohormonotherapy. We sought to study the predictive significance and correlations of transcriptional profiling of the ER, PgR and microtubule-associated protein Tau (MAP-Tau) genes in early breast cancer.

    Messenger RNA (mRNA) was extracted from 279 formalin-fixed paraffin-embedded breast carcinomas (T1-3N0-1M0) of patients enrolled in the Hellenic Cooperative Oncology Group (HeCOG) trial HE 10/97, evaluating epirubicin-alkylator based adjuvant chemotherapy with or without paclitaxel (E-T-CMF versus E-CMF). Kinetic reverse transcription polymerase chain reaction (kRT-PCR) was applied for assessment of the expression of estrogen receptor, progesterone receptor and MAP-Tau genes in 274 evaluable patients. Cohort-based cut-offs were defined at the 25th percentile mRNA value for ER and PgR and the median for MAP-Tau.

    Results: Two hundred and ten patients (77%) were ER and/or PgR-positive by immunohistochemistry (IHC). Positive ER and MAP-Tau mRNA status was significantly associated with administration of hormonal therapy and low grade, while MAP-Tau mRNA status correlated with premenopausal patient status. MAP-Tau strongly correlated with ER and PgR mRNA status (Spearmann r = 0.52 and 0.64, P < 0.001). The observed chance corrected agreement between determination of hormonal receptor status by kRT-PCR and IHC was moderate (Kappa = 0.41) for ER and fair (Kappa = 0.33) for PgR. At a median follow-up of 8 years, univariate analysis adjusted for treatment showed positive ER mRNA status to be of borderline significance for reduced risk of relapse (HR = 0.65, 95% CI 0.41-1.01, P = 0.055) and death (HR = 0.62, 95% CI 0.36-1.05, P = 0.077), while positive MAP-Tau mRNA status was significantly associated with reduced risk of relapse (HR = 0.50, 95% CI 0.32-0.78, P = 0.002) and death (HR = 0.49, 95% CI 0.29-0.83, P = 0.008). In multivariate analysis, only axillary nodal metastases (HR = 2.33, 95% CI 1.05-5.16, P = 0.04) and MAP-Tau mRNA status (HR = 0.46, 95% CI 0.25-0.85, P = 0.01) independently predicted patient outcome. However, MAP-Tau mRNA levels did not predict enhanced benefit from inclusion of paclitaxel in the adjuvant chemotherapy regimen (test for interaction P = 0.99). No correlation was evident between increasing ER and PgR mRNA transcription and increasing benefit from endocrine therapy in 203 ER and/or PgR IHC-positive patients receiving adjuvant hormone therapy (Wald P = 0.54 for ER, 0.51 for PR).

    Conclusions: ER gene transcription carries weak predictive significance for benefit from endocrine therapy or for outcome, with no apparent dose-response association. The predictive significance is possibly exerted via MAP-Tau gene expression, an ER-inducible tubulin modulator with strong predictive significance for patient outcome. However, MAP-Tau mRNA did not predict benefit from the addition of a taxane to adjuvant chemotherapy. Further study of the biologic function and utility of MAP-Tau for individualising adjuvant therapy is warranted.

    Breast cancer research and treatment 2009;116;1;131-43

  • Higher than expected progranulin mutation rate in a case series of Italian FTLD patients.

    Tremolizzo L, Gelosa G, Galbussera A, Isella V, Arosio C, Bertola F, Casati G, Piperno A, Ferrarese C and Appollonio I

    Alzheimer disease and associated disorders 2009;23;3;301

  • Markers of Alzheimer's disease in a population attending a memory clinic.

    Frisoni GB, Prestia A, Zanetti O, Galluzzi S, Romano M, Cotelli M, Gennarelli M, Binetti G, Bocchio L, Paghera B, Amicucci G, Bonetti M, Benussi L, Ghidoni R and Geroldi C

    Laboratory of Epidemiology Neuroimaging and Telemedicine, IRCCS Centro San Giovanni di Dio FBF, Brescia, Italy. gfrisoni@fatebenefratelli.it

    Background: New marker-based criteria for the diagnosis of Alzheimer's disease (AD) were recently proposed. We describe their operational translation in 144 consecutive patients referred to our Memory Clinic.

    Methods: Visual ratings of hippocampal atrophy and of cortical glucose hypometabolism in magnetic resonance imaging and positron emission tomography, and concentrations of total tau and Abeta1-42 in cerebrospinal fluid were assessed in 12 patients with subjective memory complaints (SMCs) (Mini-Mental State Examination [MMSE] score, 28.0 +/- 1.1 [mean +/- SD]), 37 with mild cognitive impairment (MCI) (MMSE, 25.1 +/- 3.6), 55 with AD (MMSE, 21.1 +/- 3.5), and 40 with non-AD dementia (MMSE, 21.6 +/- 5.5).

    Results: The sensitivity for AD of each individual biomarker was higher (65% to 87%) than for MCI (18% to 50%). Each biomarker's specificity for SMC and non-AD dementias was good to moderate (83% and 53%). Positivity for at least one marker increased the probability 38 times of belonging to the AD group (P < 0.0001).

    Conclusion: The new diagnostic criteria can be operationalized in clinical routines, but longitudinal studies of MCI patients will need to assess the criteria's prognostic value.

    Alzheimer's & dementia : the journal of the Alzheimer's Association 2009;5;4;307-17

  • PGRN mutations in northern Italy.

    Borroni B, Alberici A and Padovani A

    Alzheimer disease and associated disorders 2009;23;3;301-2

  • Prevalence and prognostic value of CSF markers of Alzheimer's disease pathology in patients with subjective cognitive impairment or mild cognitive impairment in the DESCRIPA study: a prospective cohort study.

    Visser PJ, Verhey F, Knol DL, Scheltens P, Wahlund LO, Freund-Levi Y, Tsolaki M, Minthon L, Wallin AK, Hampel H, Bürger K, Pirttila T, Soininen H, Rikkert MO, Verbeek MM, Spiru L and Blennow K

    Department of Psychiatry and Neuropsychology, Alzheimer Center Limburg, University of Maastricht, 6200 MD Maastricht, Netherlands. pj.visser@np.unimaas.nl

    Background: Alzheimer's disease (AD) pathology is common in patients with amnestic mild cognitive impairment (aMCI) without dementia, but the prevalence of AD pathology in patients with subjective cognitive impairment (SCI) and non-amnestic mild cognitive impairment (naMCI) is unknown. AD is characterised by decreased CSF concentrations of Abeta(42) and increased concentrations of tau. We investigated the prevalence of a CSF AD profile in patients with SCI, naMCI, or aMCI and the association of this profile with cognitive outcome in each group.

    Methods: Patients with SCI, naMCI, aMCI, and neurologically healthy controls were recruited from 20 memory clinics across Europe, between January, 2003, and June, 2005, into this prospective cohort study. A CSF AD profile was defined as an abnormal ratio of Abeta(42):tau. Patients were assessed annually up to 3 years. Outcome measures were changes in memory, overall cognition, mini-mental state examination (MMSE) score, daily function, and progression to AD-type dementia.

    Findings: The CSF AD profile was more common in patients with SCI (31 of 60 [52%]), naMCI (25 of 37 [68%]), and aMCI (56 of 71 [79%]) than in healthy controls (28 of 89 [31%]). The profile was associated with cognitive decline in patients with naMCI (memory, MMSE, and daily function) and in patients with aMCI (MMSE and daily function). In patients with aMCI, a CSF AD profile was predictive of AD-type dementia (OR 26.8, 95% CI 1.6-456.4).

    Interpretation: AD is a common cause of SCI, naMCI, and aMCI and is associated with cognitive decline in patients with naMCI or aMCI. Patients with SCI might be in the early stages of AD, and cognitive decline might become apparent only after longer follow-up.

    Funding: European Commission; Ana Aslan International Foundation.

    Lancet neurology 2009;8;7;619-27

  • Tau expression and efficacy of paclitaxel treatment in metastatic breast cancer.

    Tanaka S, Nohara T, Iwamoto M, Sumiyoshi K, Kimura K, Takahashi Y and Tanigawa N

    Department of General and Gastroenterological Surgery, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki City, Osaka, 569-8686, Japan.

    Purpose: Paclitaxel is widely used for the treatment of patients with metastatic breast cancer (MBC). Although several mechanisms of paclitaxel resistance have been demonstrated, useful markers of paclitaxel resistance have not been available in clinical practice.

    Methods: In this study, the clinical significance of tau expression in MBC cases was established by identifying candidates with paclitaxel administration. Tissue specimens obtained from 35 patients were examined. Status of tau expression was determined by immunohistochemistry.

    Results: Fifteen cases were classified as tau-negative and 20 cases were classified as tau-positive, respectively. Sixty percent of tau-negative expression showed favorable response. Conversely, 85% of tau-positive expression showed progressive or stable disease after paclitaxel administration. Time to disease progression in tau-negative and tau-positive groups was 9.4 +/- 6.6 and 6.0 +/- 3.7 months, respectively.

    Conclusions: Patients with tau-positive expression may derive less benefit than tau-negative from paclitaxel therapy in MBC.

    Cancer chemotherapy and pharmacology 2009;64;2;341-6

  • Role of the H1 haplotype of microtubule-associated protein tau (MAPT) gene in Greek patients with Parkinson's disease.

    Refenes N, Bolbrinker J, Tagaris G, Orlacchio A, Drakoulis N and Kreutz R

    School of Pharmacy, Department of Pharmaceutical Technology, National and Kapodistrian University of Athens, Athens, Greece. nrefenes@pharm.uoa.gr

    Background: The extended tau haplotype (H1) that covers the entire human microtubule-associated protein tau (MAPT) gene has been implicated in Parkinson's disease (PD). Nevertheless, controversial results, such as two studies in Greek populations with opposite effects, have been reported. Therefore, we set out to determine whether the H1 haplotype and additional single nucleotide polymorphisms (SNPs) included in H1 are associated with PD in a sample of Greek patients.

    Methods: We analysed MAPT haplotypes in cohorts of 122 patients and 123 controls of Greek origin, respectively. SNP genotyping was performed with Taqman assays and genotyping results were confirmed by sequencing.

    Results: The presence of the H1 haplotype was significantly associated with PD (odds ratio for H1H1 vs. H1H2 and H2H2: 1.566; 95% CI: 1.137-2.157; P = 0.006) and remained so after adjustment for sex. Further analysis of H1 sub-haplotypes with three single nucleotide polymorphisms (rs242562, rs2435207 and rs3785883) demonstrated no significant association with PD.

    Conclusion: Our data support the overall genetic role of MAPT and the H1 haplotype for PD susceptibility in Greek patients. However, the previously supported association of H1 sub-haplotypes with PD could not be confirmed in our study.

    BMC neurology 2009;9;26

  • Effect of Pin1 or microtubule binding on dephosphorylation of FTDP-17 mutant Tau.

    Yotsumoto K, Saito T, Asada A, Oikawa T, Kimura T, Uchida C, Ishiguro K, Uchida T, Hasegawa M and Hisanaga S

    Department of Biological Sciences, Faculty of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-osawa, Hachioji, Tokyo 192-0397, Japan.

    Neurodegenerative tauopathies, including Alzheimer disease, are characterized by abnormal hyperphosphorylation of the microtubule-associated protein Tau. One group of tauopathies, known as frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), is directly associated with mutations of the gene tau. However, it is unknown why mutant Tau is highly phosphorylated in the patient brain. In contrast to in vivo high phosphorylation, FTDP-17 Tau is phosphorylated less than wild-type Tau in vitro. Because phosphorylation is a balance between kinase and phosphatase activities, we investigated dephosphorylation of mutant Tau proteins, P301L and R406W. Tau phosphorylated by Cdk5-p25 was dephosphorylated by protein phosphatases in rat brain extracts. Compared with wild-type Tau, R406W was dephosphorylated faster and P301L slower. The two-dimensional phosphopeptide map analysis suggested that faster dephosphorylation of R406W was due to a lack of phosphorylation at Ser-404, which is relatively resistant to dephosphorylation. We studied the effect of the peptidyl-prolyl isomerase Pin1 or microtubule binding on dephosphorylation of wild-type Tau, P301L, and R406W in vitro. Pin1 catalyzes the cis/trans isomerization of phospho-Ser/Thr-Pro sequences in a subset of proteins. Dephosphorylation of wild-type Tau was reduced in brain extracts of Pin1-knockout mice, and this reduction was not observed with P301L and R406W. On the other hand, binding to microtubules almost abolished dephosphorylation of wild-type and mutant Tau proteins. These results demonstrate that mutation of Tau and its association with microtubules may change the conformation of Tau, thereby suppressing dephosphorylation and potentially contributing to the etiology of tauopathies.

    The Journal of biological chemistry 2009;284;25;16840-7

  • 14-3-3zeta/tau heterodimers regulate Slingshot activity in migrating keratinocytes.

    Kligys K, Yao J, Yu D and Jones JC

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Tarry 8-716, 303 E. Chicago Avenue, Chicago, IL 60611, USA.

    Defining the pathways required for keratinocyte cell migration is important for understanding mechanisms of wound healing and tumor cell metastasis. We have recently identified an alpha6beta4 integrin-Rac1 signaling pathway via which the phosphatase Slingshot (SSH) activates/dephosphorylates cofilin, thereby determining keratinocyte migration behavior. Here, we assayed the role of 14-3-3 isoforms in regulating the activity of SSH1. Using amino or carboxy terminal domains of 14-3-3zeta, we demonstrate that in keratinocytes 14-3-3zeta/tau heterodimers bind SSH1, in the absence of Rac1 signaling. This interaction leads to an inhibition of SSH1 activity, as measured by an increase in phosphorylated cofilin levels. Overexpression of the carboxy terminal domain of 14-3-3zeta acts as a dominant negative and inhibits the interaction between 14-3-3tau and SSH1. These results implicate 14-3-3zeta/tau heterodimers as key regulators of SSH1 activity in keratinocytes and suggest they play a role in cytoskeleton remodeling during cell migration.

    Funded by: NHLBI NIH HHS: T32 HL076139; NIAMS NIH HHS: R01 AR054184, R01 AR054184-16A2, R01 AR054184-18

    Biochemical and biophysical research communications 2009;383;4;450-4

  • Mapping correlations between ventricular expansion and CSF amyloid and tau biomarkers in 240 subjects with Alzheimer's disease, mild cognitive impairment and elderly controls.

    Chou YY, Leporé N, Avedissian C, Madsen SK, Parikshak N, Hua X, Shaw LM, Trojanowski JQ, Weiner MW, Toga AW, Thompson PM and Alzheimer's Disease Neuroimaging Initiative

    Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7332, USA.

    We aimed to improve on the single-atlas ventricular segmentation method of (Carmichael, O.T., Thompson, P.M., Dutton, R.A., Lu, A., Lee, S.E., Lee, J.Y., Kuller, L.H., Lopez, O.L., Aizenstein, H.J., Meltzer, C.C., Liu, Y., Toga, A.W., Becker, J.T., 2006. Mapping ventricular changes related to dementia and mild cognitive impairment in a large community-based cohort. IEEE ISBI. 315-318) by using multi-atlas segmentation, which has been shown to lead to more accurate segmentations (Chou, Y., Leporé, N., de Zubicaray, G., Carmichael, O., Becker, J., Toga, A., Thompson, P., 2008. Automated ventricular mapping with multi-atlas fluid image alignment reveals genetic effects in Alzheimer's disease, NeuroImage 40(2): 615-630); with this method, we calculated minimal numbers of subjects needed to detect correlations between clinical scores and ventricular maps. We also assessed correlations between emerging CSF biomarkers of Alzheimer's disease pathology and localizable deficits in the brain, in 80 AD, 80 mild cognitive impairment (MCI), and 80 healthy controls from the Alzheimer's Disease Neuroimaging Initiative. Six expertly segmented images and their embedded parametric mesh surfaces were fluidly registered to each brain; segmentations were averaged within subjects to reduce errors. Surface-based statistical maps revealed powerful correlations between surface morphology and 4 variables: (1) diagnosis, (2) depression severity, (3) cognitive function at baseline, and (4) future cognitive decline over the following year. Cognitive function was assessed using the mini-mental state exam (MMSE), global and sum-of-boxes clinical dementia rating (CDR) scores, at baseline and 1-year follow-up. Lower CSF Abeta(1-42) protein levels, a biomarker of AD pathology assessed in 138 of the 240 subjects, were correlated with lateral ventricular expansion. Using false discovery rate (FDR) methods, 40 and 120 subjects, respectively, were needed to discriminate AD and MCI from normal groups. 120 subjects were required to detect correlations between ventricular enlargement and MMSE, global CDR, sum-of-boxes CDR and clinical depression scores. Ventricular expansion maps correlate with pathological and cognitive measures in AD, and may be useful in future imaging-based clinical trials.

    Funded by: NCRR NIH HHS: RR019771; NIA NIH HHS: AG16570, U01 AG024904, U01 AG024904-01; NIBIB NIH HHS: EB01651; NLM NIH HHS: LM05639

    NeuroImage 2009;46;2;394-410

  • Truncated tau at D421 is associated with neurodegeneration and tangle formation in the brain of Alzheimer transgenic models.

    Zhang Q, Zhang X and Sun A

    Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China.

    In addition to tau hyperphosphorylation, tau truncation is also detected in Alzheimer's disease (AD) patients. In the brain of AD transgenic mouse models, the pathological details of truncated tau are not well characterized. In this study, we analyzed spatial relationships among tau truncation, tau phosphorylation and neurodegeneration or tangle formation in a tau(P301L) single transgenic mouse model and a triple transgenic mouse model that produces both amyloid plaques, and neurofibrillary tangles. During development of tau pathology, the spatial relationship between hyperphosphorylation and truncation of tau exhibited a shift from colocalization at low densities of hyperphosphorylated tau to partial dissociation at high densities. Importantly, we detected a few neurons that contained abundant truncated tau but were lacking hyperphosphorylation, and these neurons exhibited remarkable nuclear condensation. In the case of colocalization, truncated tau was commonly associated with high immunoreactivity of hyperphosphorylated tau and dense Gallyas silver staining. Taken together, our study shows that tau truncation appears after tau hyperphosphorylation in the brain of two transgenic mouse models, and that accumulation of truncated tau, in the absence or the presence of phosphorylated tau, is closely associated with a subset of neurons undergoing degeneration or containing neurofibrillary tangles.

    Acta neuropathologica 2009;117;6;687-97

  • Differential interaction and aggregation of 3-repeat and 4-repeat tau isoforms with 14-3-3zeta protein.

    Sadik G, Tanaka T, Kato K, Yanagi K, Kudo T and Takeda M

    Department of Psychiatry, Osaka University, Yamadaoka, Suita, Japan.

    Tau isoforms, 3-repeat (3R) and 4-repeat tau (4R), are differentially involved in neuronal development and in several tauopathies. 14-3-3 protein binds to tau and 14-3-3/tau association has been found both in the development and in tauopathies. To understand the role of 14-3-3 in the differential regulation of tau isoforms, we have performed studies on the interaction and aggregation of 3R-tau and 4R-tau, either phosphorylated or unphosphorylated, with 14-3-3zeta. We show by surface plasmon resonance studies that the interaction between unphosphorylated 3R-tau and 14-3-3zeta is approximately 3-folds higher than that between unphosphorylated 4R-tau and 14-3-3zeta. Phosphorylation of tau by protein kinase A (PKA) increases the affinity of both 3R- and 4R-tau for 14-3-3zeta to a similar level. An in vitro aggregation assay employing both transmission electron microscopy and fluorescence spectroscopy revealed the aggregation of unphosphorylated 4R-tau to be significantly higher than that of unphosphorylated 3R-tau following the induction of 14-3-3zeta. The filaments formed from 3R- and 4R-tau were almost similar in morphology. In contrast, the aggregation of both 3R- and 4R-tau was reduced to a similar low level after phosphorylation with PKA. Taken together, these results suggest that 14-3-3zeta exhibits a similar role for tau isoforms after PKA-phosphorylation, but a differential role for unphosphorylated tau. The significant aggregation of 4R-tau by 14-3-3zeta suggests that 14-3-3 may act as an inducer in the generation of 4R-tau-predominant neurofibrillary tangles in tauopathies.

    Biochemical and biophysical research communications 2009;383;1;37-41

  • Leptin inhibits glycogen synthase kinase-3beta to prevent tau phosphorylation in neuronal cells.

    Greco SJ, Sarkar S, Casadesus G, Zhu X, Smith MA, Ashford JW, Johnston JM and Tezapsidis N

    Research & Development, Neurotez, Inc., Bridgewater, NJ 08807, USA.

    We have previously demonstrated that Leptin reduces extracellular amyloid beta (Abeta) protein both in vitro and in vivo, and intracellular tau phosphorylation in vitro. Further, we have shown that these effects are dependent on activation of AMP-activated protein kinase (AMPK) in vitro. Herein, we investigated downstream effectors of AMPK signaling directly linked to tau phosphorylation. One such target, of relevance to Alzheimer's disease (AD), may be GSK-3beta, which has been shown to be inactivated by Leptin. We therefore dissected the role of GSK-3beta in mediating Leptin's ability to reduce tau phosphorylation in neuronal cells. Our data suggest that Leptin regulates tau phosphorylation through a pathway involving both AMPK and GSK-3beta. This was based on the following: Leptin and the cell-permeable AMPK activator, 5-aminoimidazole-4-carboxyamide ribonucleoside (AICAR), reduced tau phosphorylation at AD-relevant sites similarly to the GSK-3beta inhibitor, lithium chloride (LiCl). Further, this reduction of tau phosphorylation was mimicked by the downregulation of GSK-3beta, achieved using siRNA technology and antagonized by the ectopic overexpression of GSK-3beta. These studies provide further insight into Leptin's mechanism of action in suppressing AD-related pathways.

    Funded by: NIA NIH HHS: 1R43AG029670, R43 AG029670, R43 AG029670-01A1, R43 AG029670-02

    Neuroscience letters 2009;455;3;191-4

  • Familial FTDP-17 missense mutations inhibit microtubule assembly-promoting activity of tau by increasing phosphorylation at Ser202 in vitro.

    Han D, Qureshi HY, Lu Y and Paudel HK

    Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital.

    In Alzheimer disease (AD), frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) and other tauopathies, tau accumulates and forms paired helical filaments (PHFs) in the brain. Tau isolated from PHFs is phosphorylated at a number of sites, migrates as approximately 60-, 64-, and 68-kDa bands on SDS-gel, and does not promote microtubule assembly. Upon dephosphorylation, the PHF-tau migrates as approximately 50-60-kDa bands on SDS-gels in a manner similar to tau that is isolated from normal brain and promotes microtubule assembly. The site(s) that inhibits microtubule assembly-promoting activity when phosphorylated in the diseased brain is not known. In this study, when tau was phosphorylated by Cdk5 in vitro, its mobility shifted from approximately 60-kDa bands to approximately 64- and 68-kDa bands in a time-dependent manner. This mobility shift correlated with phosphorylation at Ser(202), and Ser(202) phosphorylation inhibited tau microtubule-assembly promoting activity. When several tau point mutants were analyzed, G272V, P301L, V337M, and R406W mutations associated with FTDP-17, but not nonspecific mutations S214A and S262A, promoted Ser(202) phosphorylation and mobility shift to a approximately 68-kDa band. Furthermore, Ser(202) phosphorylation inhibited the microtubule assembly-promoting activity of FTDP-17 mutants more than of WT. Our data indicate that FTDP-17 missense mutations, by promoting phosphorylation at Ser(202), inhibit the microtubule assembly-promoting activity of tau in vitro, suggesting that Ser(202) phosphorylation plays a major role in the development of NFT pathology in AD and related tauopathies.

    The Journal of biological chemistry 2009;284;20;13422-33

  • SUT-2 potentiates tau-induced neurotoxicity in Caenorhabditis elegans.

    Guthrie CR, Schellenberg GD and Kraemer BC

    Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA.

    Expression of human tau in Caenorhabditis elegans neurons causes accumulation of aggregated tau leading to neurodegeneration and uncoordinated movement. We used this model of human tauopathy disorders to screen for genes required for tau neurotoxicity. Recessive loss-of-function mutations in the sut-2 locus suppress the Unc phenotype, tau aggregation and neurodegenerative changes caused by human tau. We cloned the sut-2 gene and found it encodes a novel sub-type of CCCH zinc finger protein conserved across animal phyla. SUT-2 shares significant identity with the mammalian SUT-2 (MSUT-2). To identify SUT-2 interacting proteins, we conducted a yeast two hybrid screen and found SUT-2 binds to ZYG-12, the sole C. elegans HOOK protein family member. Likewise, SUT-2 binds ZYG-12 in in vitro protein binding assays. Furthermore, loss of ZYG-12 leads to a marked upregulation of SUT-2 protein supporting the connection between SUT-2 and ZYG-12. The human genome encodes three homologs of ZYG-12: HOOK1, HOOK2 and HOOK3. Of these, the human ortholog of SUT-2 (MSUT-2) binds only to HOOK2 suggesting the interaction between SUT-2 and HOOK family proteins is conserved across animal phyla. The identification of sut-2 as a gene required for tau neurotoxicity in C. elegans may suggest new neuroprotective strategies capable of arresting tau pathogenesis in tauopathy disorders.

    Funded by: NIA NIH HHS: P01 AG17586

    Human molecular genetics 2009;18;10;1825-38

  • The effects of normal aging and ApoE genotype on the levels of CSF biomarkers for Alzheimer's disease.

    Glodzik-Sobanska L, Pirraglia E, Brys M, de Santi S, Mosconi L, Rich KE, Switalski R, Saint Louis L, Sadowski MJ, Martiniuk F, Mehta P, Pratico D, Zinkowski RP, Blennow K and de Leon MJ

    New York University School of Medicine, New York, NY 10016, United States.

    While cerebrospinal fluid (CSF) biomarkers are of use in the prediction and diagnosis of Alzheimer's disease our understanding of the background effects of age and the ApoE genotype is limited. Seventy-eight community-based normal volunteers (mean age 60+/-10 years, range 36-86) were examined to determine the relationships between CSF measures of total tau (T-tau), hyperphosphorylated tau (P-tau 231), amyloid beta (Abeta42/Abeta40 ratio), and isoprostane (IP) with age and ApoE genotype. The results showed that age by epsilon4 genotype interactions were found for P-tau231 (beta=1.82; p<0.05) and IP (beta=1.6; p<0.05). T-tau CSF concentration increased with age. The increasing CSF concentrations of P-tau and IP in epsilon4 carriers suggest that early tauopathy and oxidative stress may be related to the increased risk for AD. The data also suggest that T-tau changes are more age dependent than Abeta changes. The evidence that P-tau231 and IP are the earliest markers for the neuronal damage related to AD awaits longitudinal study.

    Funded by: NCRR NIH HHS: M01 RR000096, M01 RR000096-478521, MO1RR0096; NIA NIH HHS: AG022374, AG08051, AG12101, P30 AG008051, P30 AG008051-199005, R01 AG012101, R01 AG012101-15, R01 AG013616, R01 AG022374, R01 AG022374-05

    Neurobiology of aging 2009;30;5;672-81

  • Cerebrospinal fluid biomarkers and rate of cognitive decline in very mild dementia of the Alzheimer type.

    Snider BJ, Fagan AM, Roe C, Shah AR, Grant EA, Xiong C, Morris JC and Holtzman DM

    Department of Neurology, Washington University School of Medicine, Campus Box 8111, 660 S Euclid, St Louis, MO 63110, USA. sniderj@neuro.wustl.edu

    Background: Cerebrospinal fluid (CSF) levels of Abeta peptide 1-42 (Abeta 42), tau, and phosphorylated tau (ptau) are potential biomarkers of Alzheimer disease.

    Objective: To determine whether Abeta 42, tau, and ptau predict the rate of cognitive change in individuals with very mild dementia of the Alzheimer type (DAT).

    Design: Retrospective analysis of CSF biomarkers and clinical data.

    Setting: An academic Alzheimer disease research center.

    Participants: Research volunteers in a longitudinal study of aging and cognition. Participants (n = 49) had a clinical diagnosis of very mild DAT with a Clinical Dementia Rating (CDR) of 0.5 at the time of lumbar puncture. All the participants had at least 1 follow-up assessment (mean [SD] follow-up, 3.5 [1.8] years).

    Baseline CSF levels of Abeta 42, Abeta 40, tau, and ptau at threonine 181 (ptau181) and the rate of dementia progression as measured using the CDR sum of boxes (CDR-SB) score and psychometric performance.

    Results: The rate of dementia progression was significantly more rapid in individuals with lower baseline CSF Abeta 42 levels, higher tau or ptau181 levels, or high tau: Abeta 42 ratios. For example, the annual change in the CDR-SB score was 1.1 for the lowest 2 tertiles of Abeta 42 values and 0.3 for the highest tertile of Abeta 42 values.

    Conclusions: In individuals with very mild DAT, lower CSF Abeta 42 levels, high tau or ptau181 levels, or high tau:Abeta 42 ratios quantitatively predict more rapid progression of cognitive deficits and dementia. Biomarkers of CSF may be useful prognostically and to identify individuals who are more likely to progress for participation in therapeutic clinical trials.

    Funded by: NIA NIH HHS: P01 AG003991, P01 AG003991-25, P01AG003991, P50 AG005681, P50 AG005681-25, P50AG005681

    Archives of neurology 2009;66;5;638-45

  • Cholinesterase inhibitors may increase phosphorylated tau in Alzheimer's disease.

    Chalmers KA, Wilcock GK, Vinters HV, Perry EK, Perry R, Ballard CG and Love S

    Dementia Research Group, Department of Clinical Science at North Bristol, University of Bristol, Bristol, UK. katy.chalmers@bristol.ac.uk

    Cholinesterase inhibitors (ChEIs) are widely used for the symptomatic treatment of Alzheimer's disease (AD). In vitro and in animal studies, ChEIs have been shown to influence the processing of Abeta and the phosphorylation of tau, proteins that are the principal constituents of the plaques and neurofibrillary tangles, respectively, in AD brain. However, little is known about the effects of these drugs on Abeta and tau pathology in AD. Using avidin-biotin immunohistochemistry and computer-assisted image analysis, we compared Abeta and tau loads in the frontal and temporal cortices of 72 brains from matched cohorts of AD patients who had or had not received ChEIs. Patients treated with ChEIs had accumulated significantly more phospho-tau in their cerebral cortex than had untreated patients (P = 0.004). Abeta accumulation was reduced but not significantly. These data raise the possibility that increased tau phosphorylation may influence long-term clinical responsiveness to ChEIs.

    Funded by: Medical Research Council: G0400074, G0502157; NIA NIH HHS: P50 AG 16570, P50 AG016570, P50 AG016570-11A1

    Journal of neurology 2009;256;5;717-20

  • Increased association between rough endoplasmic reticulum membranes and mitochondria in transgenic mice that express P301L tau.

    Perreault S, Bousquet O, Lauzon M, Paiement J and Leclerc N

    Departement de Pathologie et Biologie Cellulaire, Université de Montréal, Montréal, Québec, Canada.

    In several neurodegenerative diseases, including Alzheimer disease, the neuronal microtubule-associated protein tau becomes hyperphosphorylated, accumulates in the somatodendritic compartment, and aggregates into insoluble filaments. The consequences of the accumulation of hyperphosphorylated tau in the somatodendritic compartment remain poorly characterized at the early stage of disease before the formation of tau insoluble filaments. We investigated the ultrastructural changes induced by this accumulation in the neuronal soma of motor neurons in asymptomatic JNPL3 mice that overexpress mutant tau, P301L. More numerous contacts between rough endoplasmic reticulum (RER) membranes and mitochondria were observed in JNLP3 mice compared with wild-type mice. This correlated with a preferential increase of the amount of tau at the surface of RER membranes but not at the surface of mitochondria, as revealed by tau immunogold labeling. Using a subcellular fractionation procedure, an increased amount of phosphorylated tau was identified in the rough microsome subfraction, wherein the RER marker, ribophorin, was enriched. A similar increase was noted in the rough microsome subfraction isolated from Alzheimer disease brains. The association of hyperphosphorylated tau with ER membranes was confirmed by double immunogold labeling of the subfraction enriched in ER membranes isolated from Alzheimer disease brains. These results suggest that more contacts between RER membranes and mitochondria resulting from the accumulation of tau at the surface of RER membranes might contribute to tau-induced neurodegeneration.

    Journal of neuropathology and experimental neurology 2009;68;5;503-14

  • NAP protects memory, increases soluble tau and reduces tau hyperphosphorylation in a tauopathy model.

    Shiryaev N, Jouroukhin Y, Giladi E, Polyzoidou E, Grigoriadis NC, Rosenmann H and Gozes I

    The Adams Super Center for Brain Studies, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Israel.

    NAP (NAPVSIPQ) provides broad neuroprotection through microtubule interaction. Here, NAP was investigated for neuroprotection in an in vivo tauopathy model. Transgenic mice (2-month-old) that express the human double mutant tau protein [P301S;K257T] fused to the tau promoter, were subjected to daily intranasal drug treatment for approximately 5 months. Results showed increased performance in the NAP-treated mice compared to controls, as demonstrated in the Morris water maze, (p<0.05). Treatment continued for 5 additional months and mouse cortices were biochemically analyzed. Protein extraction identified increased tau protein content in the heat-stable soluble fraction, which contains microtubule-associated tau, in the 1-year-old NAP-treated mice as compared to vehicle-controls. Tau phosphorylation (Ser 202) increased in the tau-transgenic mice compared to control mice, and was significantly reduced in NAP-treated mice. The current studies show for the first time activity for NAP in a "pure" tauopathy model, positioning it as a promising drug candidate in multiple neurodegenerative tauopathies.

    Neurobiology of disease 2009;34;2;381-8

  • Prediction and longitudinal study of CSF biomarkers in mild cognitive impairment.

    Brys M, Pirraglia E, Rich K, Rolstad S, Mosconi L, Switalski R, Glodzik-Sobanska L, De Santi S, Zinkowski R, Mehta P, Pratico D, Saint Louis LA, Wallin A, Blennow K and de Leon MJ

    New York University School of Medicine, NY, USA.

    Objectives: To longitudinally evaluate five cerebrospinal fluid (CSF) biomarkers in the transition from mild cognitive impairment (MCI) to Alzheimer's disease (AD).

    Methods: A baseline and 2-year follow-up clinical and CSF study of 86 subjects, including 22 MCI patients that declined to AD (MCI-AD), 43 MCI that did not deteriorate (MCI-MCI) and 21 controls (NL-NL). All subjects were studied for total and phosphorylated tau (T-tau, P-tau(231)), amyloid beta (Abeta) Abeta(42)/Abeta(40) ratio, isoprostane (IP) as well as P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios.

    Results: At baseline and at follow-up MCI-AD showed higher levels P-tau(231), T-tau, IP, P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios and lower Abeta(42)/Abeta(40) than MCI-MCI or NL-NL. Baseline P-tau(231) best predicted MCI-AD (80%, p<0.001) followed in accuracy by P-tau(231)/Abeta(42/40) and T-tau/Abeta(42/40) ratios (both 75%, p's<0.001), T-tau (74%, p<0.001), Abeta(42)/Abeta(40) (69%, p<0.01), and IP (68%, p<0.01). Only IP showed longitudinal effects (p<0.05).

    Conclusions: P-tau(231) is the strongest predictor of the decline from MCI to AD. IP levels uniquely show longitudinal progression effects. These results suggest the use of CSF biomarkers in secondary prevention trials.

    Funded by: NCRR NIH HHS: M01 RR000096, M01 RR000096-47, MO1RR0096; NIA NIH HHS: AG03051, AG08051, AG12101, P30 AG008051, P30 AG008051-089005, P30 AG008051-199005, R01 AG003051, R01 AG003051-18, R01 AG012101, R01 AG012101-13, R01 AG012101-15, R01 AG013616, R01 AG013616-17, R01 AG022374, R01 AG022374-05

    Neurobiology of aging 2009;30;5;682-90

  • Prothrombotic genetic variants and atherosclerosis in patients with cerebral ischemia of arterial origin.

    Pruissen DM, Kappelle LJ, Rosendaal FR, Algra A and SMART Study Group

    Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands.

    Objective: Prothrombotic genetic variants associated with arterial disease probably affect arterial thrombus formation but may also promote atherosclerosis. We hypothesized that specific prothrombotic variants lead to advanced atherosclerosis in patients with cerebral ischemia of arterial origin.

    We included 689 patients with nondisabling cerebral ischemia of arterial origin. Twenty-two variants in 14 genes were genotyped. None of the variants was associated with carotid intima-media thickness or younger age at the occurrence of cerebral ischemia. Factor V Leiden (mean prevalence difference 25%; 95% CI 11-40) and the glycoprotein 1b-alpha Thr145Met variant (mean prevalence difference 12%; 95% CI 2.3-22) were associated with symptomatic carotid stenosis. After accounting for multiple testing by determination of the false discovery rate, only the association between factor V Leiden and symptomatic carotid stenosis remained present.

    Conclusions: Prothrombotic genetic variants showed no consistent association with three markers of advanced atherosclerosis in patients with cerebral ischemia of arterial origin. This study does not support the hypothesis that prothrombotic genetic variants have a direct role in the pathogenesis of atherosclerosis.

    Atherosclerosis 2009;204;1;191-5

  • Do polymorphisms in the familial Parkinsonism genes contribute to risk for sporadic Parkinson's disease?

    Sutherland GT, Halliday GM, Silburn PA, Mastaglia FL, Rowe DB, Boyle RS, O'Sullivan JD, Ly T, Wilton SD and Mellick GD

    Eskitis Institute for Cell and Molecular Therapies, School of Biomolecular and Physical Sciences, Griffith University, Brisbane, Queensland, Australia.

    Recent whole genome association studies provided little evidence that polymorphisms at the familial Parkinsonism loci influence the risk for Parkinson's disease (PD). However, these studies are not designed to detect the types of subtle effects that common variants may impose. Here, we use an alternative targeted candidate gene approach to examine common variation in 11 genes related to familial Parkinsonism. PD cases (n = 331) and unaffected control subjects (n = 296) were recruited from three specialist movement disorder clinics in Brisbane, Australia and the Australian Electoral Roll. Common genetic variables (76 SNPs and 1 STR) were assessed in all subjects and haplotype, genotype, and allele associations explored. Modest associations (uncorrected P < 0.05) were observed for common variants around SNCA, UCHL1, MAPT, and LRRK2 although none were of sufficient magnitude to survive strict statistical corrections for multiple comparisons. No associations were seen for PRKN, PINK1, GBA, ATP13A2, HTRA2, NR4A2, and DJ1. Our findings suggest that common genetic variables of selected PD-related loci contribute modestly to PD risk in Australians.

    Movement disorders : official journal of the Movement Disorder Society 2009;24;6;833-8

  • Human misfolded truncated tau protein promotes activation of microglia and leukocyte infiltration in the transgenic rat model of tauopathy.

    Zilka N, Stozicka Z, Kovac A, Pilipcinec E, Bugos O and Novak M

    Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovak Republic.

    It has been hypothesized that misfolded tau protein could be a mediator of the inflammatory response in human tauopathies. Here we show that neurodegenerative lesions caused by human truncated tau promote inflammatory response manifested by upregulation of immune-molecules (CD11a,b, CD18, CD4, CD45 and CD68) and morphological activation of microglial cells in a rat model of tauopathy. In parallel, the innate immune brain response promotes activation of MHC class II positive blood-borne leukocytes and their influx into the brain parenchyma. These findings have important consequences for the rationale drug development of effective inflammation-based therapeutic strategies for human tauopathies.

    Journal of neuroimmunology 2009;209;1-2;16-25

  • CSF biomarkers in relationship to cognitive profiles in Alzheimer disease.

    van der Vlies AE, Verwey NA, Bouwman FH, Blankenstein MA, Klein M, Scheltens P and van der Flier WM

    Department of Neurology and Alzheimer Center, VU University Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands. ae.vdvlies@vumc.nl

    Objective: To investigate the relationship between CSF biomarkers and cognitive profiles in Alzheimer disease (AD).

    Methods: We included 177 patients with AD. Digit Span, Visual Association Test (VAT), VAT object naming, Trail Making Test (TMT), and category fluency were used to assess cognitive functions. Disease severity was assessed using Mini-Mental State Examination; functional impairment was rated by Clinical Dementia Rating. In CSF, levels of amyloid-beta 1-42 (Abeta(1-42)), tau, and tau phosphorylated at threonine 181 (p-tau) were measured. K-means cluster analysis was performed with the three biomarkers to obtain three clusters. Multivariate analysis of variance for repeated measures was performed with CSF cluster as between-subjects factor, neuropsychological z scores as within-subjects variable, and age, sex, and education as covariates.

    Results: Cluster 1 consisted of 88 patients (49%) with relatively high levels of Abeta(1-42) and low levels of tau and p-tau. Cluster 2 contained 72 patients (41%) with relatively low levels of Abeta(1-42) and high levels of tau and p-tau. Cluster 3 was made up of 17 patients (10%) with low levels of Abeta(1-42) and very high levels of tau and p-tau. No differences between clusters on age, sex, education, APOE genotype, disease duration, functional impairment, or disease severity were found. Patients in cluster 3 performed worse on VAT, TMT-A and -B, and fluency.

    Conclusions: Clusters of CSF biomarker levels are related to cognitive profiles in Alzheimer disease. A subgroup of patients with extremely high CSF levels of tau and tau phosphorylated at threonine 181 shows a distinct cognitive profile with more severe impairment of memory, mental speed, and executive functions, which cannot be explained by disease severity.

    Neurology 2009;72;12;1056-61

  • Tau mutations in neurodegenerative diseases.

    Wolfe MS

    Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. mwolfe@rics.bwh.harvard.edu

    Tau deposition is found in a variety of neurodegenerative brain diseases. The identification of tau mutations that cause familial dementia demonstrated that aberrant Tau alone could cause neurodegenerative disease and suggested that Tau likely plays a role in other cases in which Tau deposits are found, most notably Alzheimer disease. The mechanisms by which tau mutations cause neurodegeneration vary and are unclear to some degree, but evidence supports changes in alternative splicing, phosphorylation state, interaction with tubulin, and self-association into filaments as important contributing factors.

    The Journal of biological chemistry 2009;284;10;6021-5

  • Voxel-based morphometry patterns of atrophy in FTLD with mutations in MAPT or PGRN.

    Whitwell JL, Jack CR, Boeve BF, Senjem ML, Baker M, Rademakers R, Ivnik RJ, Knopman DS, Wszolek ZK, Petersen RC and Josephs KA

    Department of Radiology Research, Mayo Clinic, Rochester, MN 55905, USA.

    Objective: To compare patterns of gray matter loss in subjects with mutations in the progranulin (PGRN) gene to subjects with mutations in the microtubule-associated protein tau (MAPT) gene.

    Methods: We identified all subjects seen at the Mayo Clinic, Rochester, MN, who had screened positive for mutations in PGRN or MAPT and had a head MRI. Twelve cases with mutations in the PGRN gene were matched by time from disease onset to scan to 12 subjects with mutations in the MAPT gene. Voxel-based morphometry was used to assess patterns of gray matter loss in the PGRN and MAPT groups compared to a control cohort, and compared to each other. MAPT subjects were younger than the PGRN subjects; therefore, each group was also compared to a specific age-matched control group.

    Results: Both PGRN and MAPT groups showed gray matter loss in frontal, temporal, and parietal lobes compared to controls, although loss was predominantly identified in posterior temporal and parietal lobes in PGRN and anteromedial temporal lobes in MAPT. The MAPT group had greater loss compared to healthy subjects of the same age than the PGRN subjects when compared to healthy subjects of the same age. The MAPT subjects showed greater gray matter loss in the medial temporal lobes, insula, and putamen than the PGRN subjects.

    Conclusion: These results increase understanding of the biology of these disorders and suggest that patterns of atrophy on MRI may be useful to aid in the differentiation of groups of PGRN and MAPT mutation carriers.

    Funded by: NCRR NIH HHS: C06 RR018898; NIA NIH HHS: P50-AG16574, R01-AG11378, U01-AG06786; NICHD NIH HHS: K12 HD49078; NINDS NIH HHS: P50 NS40256

    Neurology 2009;72;9;813-20

  • Tau deletion exacerbates the phenotype of Niemann-Pick type C mice and implicates autophagy in pathogenesis.

    Pacheco CD, Elrick MJ and Lieberman AP

    Neuroscience Program, The University of Michigan Medical School, 3510 MSRB1, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA.

    Hyperphosphorylation and aggregation of the microtubule-binding protein tau characterize a diverse array of neurodegenerative disorders. Most of these lack mutations in the encoding MAPT gene, and the role of tau in disease pathogenesis remains controversial. Among these tauopathies is Niemann-Pick type C disease (NPC), a lysosomal storage disorder characterized by progressive neurodegeneration and premature death, most often caused by an inherited deficiency in the intracellular lipid trafficking protein NPC1. To determine the extent to which tau affects NPC pathogenesis, we generated Npc1-/- mice deficient in tau. Unexpectedly, NPC1/tau double null mutants are generated in markedly smaller litters, exhibit an enhanced systemic phenotype and die significantly earlier than NPC1 single null mutants. As autophagy is up-regulated in NPC and protein degradation through this pathway depends on movement along microtubules, we knocked down MAPT expression in NPC1-deficient human fibroblasts and examined effects on this pathway. We show that an acute reduction of tau expression in a cellular model of NPC decreases induction and flux through the autophagic pathway. Our data establish that MAPT deletion exacerbates the NPC phenotype through a mechanism independent of tau protein aggregation and identifies a critical role for tau in the regulation of autophagy in NPC1-deficient cells.

    Funded by: NIGMS NIH HHS: T32 GM 07863; NINDS NIH HHS: F31 NS051143-03, F31 NS51143

    Human molecular genetics 2009;18;5;956-65

  • Clinical and pathological features of an Alzheimer's disease patient with the MAPT Delta K280 mutation.

    Momeni P, Pittman A, Lashley T, Vandrovcova J, Malzer E, Luk C, Hulette C, Lees A, Revesz T, Hardy J and de Silva R

    Laboratory of Neurogenetics, NIA, NIH Main Campus, Bethesda, MD 20892, USA.

    We identified a case of Alzheimer's disease with a deletion of the lysine residue at codon 280 (DeltaK280) in exon 10-encoded microtubule-binding repeat domain of the tau gene (MAPT). This mutation was originally identified in a sporadic case of frontotemporal dementia (FTD) with a family history of Parkinson's disease. In the original report, the authors were careful in their assessment of the pathogenicity and suggested one could not be sure whether the mutation was pathogenic or not. The mutation has always presented a conundrum because it is the only known mutation, of assumed pathogenicity, which increases the proportion of 3-repeat tau mRNA in in vitro assays. Here we present the clinical and pathological features of a new case with this mutation and discuss whether the mutation is indeed pathogenic.

    Funded by: Medical Research Council: G0501560, G0501560(76517); NIA NIH HHS: P50 AG005128-19S19003, P50 AG05128

    Neurobiology of aging 2009;30;3;388-93

  • H1 haplotype of the MAPT gene is associated with lower regional gray matter volume in healthy carriers.

    Canu E, Boccardi M, Ghidoni R, Benussi L, Testa C, Pievani M, Bonetti M, Binetti G and Frisoni GB

    LENITEM Laboratory of Epidemiology, Neuroimaging, and Telemedicine, IRCCS Centro S Giovanni di Dio-FBF, Brescia, Italy.

    The microtubule-associated protein Tau (MAPT) gene codes for the protein Tau that is involved in the pathogenesis of neurodegenerative diseases. Recent studies have detected an over-representation of the H1 haplotype of the MAPT gene in neurodegenerative disorders such as progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), frontotemporal dementia (FTD) and Parkinson's disease (PD), whereas the H2 haplotype has been found to be related to familial FTD. We aimed to investigate the association between MAPT haplotype status and brain morphology in healthy adults. A total of 150 healthy subjects underwent 3D high-resolution magnetic resonance (MR). MR images were processed following an optimized protocol to perform the Voxel-based morphometry (VBM) comparisons of the gray matter (GM) in H1 carriers (n=141) in contrast to H2H2 homozygous (n=9), and H1H1 homozygous (n=85) in contrast to H2 carriers (n=65). The threshold for statistical significance was 0.005 uncorrected. Opposite comparisons were also carried out. The groups had similar demographic and cognitive features. Compared with H2H2, the H1 carriers showed up to 19% smaller GM volume in the head of the right caudate nucleus, in the right middle frontal gyrus, in the left insula and orbito-frontal cortex, and in the inferior temporal and inferior cerebellar lobes, bilaterally. Compared with all H2 carriers, H1H1 displayed lower GM in the same regions, but the effect was smaller (5%), possibly due to a dilution effect by H1 in the H2 carriers group. The data suggest that H1 haplotype is associated with a particular cerebral morphology that may increase the susceptibility of the healthy carriers to develop neurodegenerative diseases such as sporadic tauopathies.

    European journal of human genetics : EJHG 2009;17;3;287-94

  • Inverse association of cortisol serum levels with T-tau, P-tau 181 and P-tau 231 peptide levels and T-tau/Abeta 1-42 ratios in CSF in patients with mild Alzheimer's disease dementia.

    Laske C, Stransky E, Fritsche A, Eschweiler GW and Leyhe T

    Dept. of Psychiatry and Psychotherapy, University of Tuebingen, Osianderstr. 24, 72076, Tuebingen, Germany. christoph.laske@med.uni-tuebingen.de

    Hypercortisolemia and increased levels of hyperphosphorylated tau proteins in cerebrospinal fluid (CSF) are common features with pathogenic relevance in Alzheimer;s disease (AD). Experimental studies point to an influence of cortisol on Abeta and tau pathology in AD. Association of both parameters have not yet been described in a sample of AD patients. In the present study, serum levels of cortisol were determined in 26 patients with mild AD dementia and 20 age-matched healthy elderly controls by ELISA. In addition, we measured in AD patients CSF levels of cortisol, total tau (T-tau), tau phosphorylated at threonine 181 (P-tau 181), tau protein phosphorylated at threonine 231 (P-tau 231) and beta-Amyloid (Abeta) 1-42 and determined T-tau/Abeta 1-42 ratios in CSF. We found in AD patients significantly increased cortisol serum levels (551.4 +/- 146.1 nmol/l; P = 0.002) as compared to healthy controls (435.3 +/- 83.9 nmol/l). In AD patients, cortisol serum levels were significantly inversely correlated with T-tau (r = -0.496; P = 0.01), P-tau 181 (r = -0.558; P = 0.003) and P-tau 231 (-0.500; P = 0.009) protein levels and T-tau/Abeta 1-42 ratios (r = -0.450; P = 0.021) in CSF. In addition, cortisol serum levels showed a trend of positive correlation with Abeta 1-42 CSF levels (r = 0.386; P = 0.052). However, no significant correlations of cortisol serum with CSF levels as well as cortisol CSF levels with CSF biomarkers could be detected in AD patients. In conclusion, our results show that increased cortisol serum but not CSF levels are associated with minor signs of AD pathology in CSF, indicating a putative neuroprotective effect of moderately elevated cortisol serum levels in patients with mild AD dementia.

    European archives of psychiatry and clinical neuroscience 2009;259;2;80-5

  • Structural polymorphism of 441-residue tau at single residue resolution.

    Mukrasch MD, Bibow S, Korukottu J, Jeganathan S, Biernat J, Griesinger C, Mandelkow E and Zweckstetter M

    Department for Nuclear Magnetic Resonance (NMR)-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.

    Alzheimer disease is characterized by abnormal protein deposits in the brain, such as extracellular amyloid plaques and intracellular neurofibrillary tangles. The tangles are made of a protein called tau comprising 441 residues in its longest isoform. Tau belongs to the class of natively unfolded proteins, binds to and stabilizes microtubules, and partially folds into an ordered beta-structure during aggregation to Alzheimer paired helical filaments (PHFs). Here we show that it is possible to overcome the size limitations that have traditionally hampered detailed nuclear magnetic resonance (NMR) spectroscopy studies of such large nonglobular proteins. This is achieved using optimal NMR pulse sequences and matching of chemical shifts from smaller segments in a divide and conquer strategy. The methodology reveals that 441-residue tau is highly dynamic in solution with a distinct domain character and an intricate network of transient long-range contacts important for pathogenic aggregation. Moreover, the single-residue view provided by the NMR analysis reveals unique insights into the interaction of tau with microtubules. Our results establish that NMR spectroscopy can provide detailed insight into the structural polymorphism of very large nonglobular proteins.

    PLoS biology 2009;7;2;e34

  • The +347 C promoter allele up-regulates MAPT expression and is associated with Alzheimer's disease among the Chinese Han.

    Sun W and Jia J

    Department of Neurology, Xuan Wu Hospital of the Capital Medical University, Key Neurodegenerative Laboratory of Ministry of Education of the People's Republic of China, Beijing 100053, China.

    The microtubule-associated protein tau has been known to be associated with the pathogenesis of Alzheimer's disease (AD). We identified a novel single nucleotide polymorphism (SNP) in the promoter region of the microtubule-associated protein tau gene (MAPT) in Chinese Han population: 347G/C. The samples we analyzed were all identified as H1/H1 genotype; the 347C allele was over-represented in 252 sporadic AD patients (84.3%, P=0.006) when compared with 197 controls (75.1%). The transcriptional activity of SNP in promoter was further investigated using a luciferase reporter assay in two human cell lines, SH-SY5Y and Hela. We demonstrated that the promoter transcriptional activity of the 347 C/C genotype was significantly higher than that of the 347 G/G genotype (SH-SY5Y, P=0.0321; Hela, P=0.0016). Our data suggest that the 347C polymorphism in the promoter of MAPT gene, which is associated with an up-regulation of the gene expression, is a susceptibility factor in sporadic AD.

    Neuroscience letters 2009;450;3;340-3

  • Conformational diversity of wild-type Tau fibrils specified by templated conformation change.

    Frost B, Ollesch J, Wille H and Diamond MI

    Department of Neurology, University of California, San Francisco, California 94158, USA.

    Tauopathies are sporadic and genetic neurodegenerative diseases characterized by aggregation of the microtubule-associated protein Tau. Tau pathology occurs in over 20 phenotypically distinct neurodegenerative diseases, including Alzheimer disease and frontotemporal dementia. The molecular basis of this diversity among sporadic tauopathies is unknown, but distinct fibrillar wild-type (WT) Tau conformations could play a role. Using Fourier transform infrared spectroscopy, circular dichroism, and electron microscopy, we show that WT Tau fibrils and P301L/V337M Tau fibrils have distinct secondary structures, fragilities, and morphologies. Furthermore, P301L/V337M fibrillar seeds induce WT Tau monomer to form a novel fibrillar conformation, termed WT*, that is maintained over multiple seeding reactions. WT* has secondary structure, fragility, and morphology that are similar to P301L/V337M fibrils and distinct from WT fibrils. WT Tau is thus capable of conformational diversity that arises via templated conformation change, as has been described for amyloid beta, beta2-microglobulin, and prion proteins.

    Funded by: NINDS NIH HHS: R01 NS50284-03

    The Journal of biological chemistry 2009;284;6;3546-51

  • Substrate-specific reduction of PP2A activity exaggerates tau pathology.

    Deters N, Ittner LM and Götz J

    Alzheimer's and Parkinson's Disease Laboratory, Brain and Mind Research Institute, University of Sydney, 100 Mallett Street, Camperdown, NSW 2050, Australia.

    Phosphorylation of the microtubule-associated protein tau is regulated by the balanced interplay of kinases and phosphatases. Disturbance of this balance causes hyperphosphorylation of tau and neurofibrillary tangle formation in Alzheimer's disease brain. Here, we crossed Dom5 mice that express a substrate-specific dominant negative mutant form, L309A Calpha, of protein phosphatase 2A (PP2A) with neurofibrillary-tangle-forming P301L mutant tau transgenic pR5 mice. This exacerbated the tau pathology of pR5 mice significantly. Double-transgenic Dom5/pR5 mice showed 7-fold increased numbers of hippocampal neurons that specifically phosphorylated the pathological S422 epitope of tau. They showed 8-fold increased numbers of tangles compared to pR5 mice, in agreement with our previous finding that tangle formation is correlated with and preceded by phosphorylation of tau at the S422 epitope. This suggests that, in addition to kinases, PP2A and its regulatory subunits may be a therapeutic target for Alzheimer's disease.

    Biochemical and biophysical research communications 2009;379;2;400-5

  • The assessment of beta amyloid, tau protein and cystatin C in the cerebrospinal fluid: laboratory markers of neurodegenerative diseases.

    Mares J, Kanovsky P, Herzig R, Stejskal D, Vavrouskova J, Hlustik P, Vranova H, Burval S, Zapletalova J, Pidrman V, Obereigneru R, Suchy A, Vesely J, Podivinsky J and Urbanek K

    Clinic of Neurology, University Hospital, Olomouc, Czech Republic. maresja@seznam.cz

    To assess the role of tau protein, beta-amyloid(1-42) and cystatin C in the diagnostics of Alzheimer dementia (AD) and other neurodegenerative diseases (ND) by comparing to the control groups (CG). The levels of tau protein, beta-amyloid(1-42) and cystatin C were assessed in the set of 69 patients (AD + ND, 33 males, 36 females, aged 22-90, mean 60.5 + 16.1 years), and in a control group of 69 subjects without the affection of the central nervous system (CGAD + CGND, 33 males, 36 females, aged 20-91, mean 60.5 + 16.0 years). Statistically significant increased tau protein levels (P = 0.0001) and index tau/beta-amyloid(1-42) levels (P = 0.0002) were shown in the group of AD patients, compared to the group of ND patients. One-way ANOVA analysis with Bonferonni post hoc test did not show any significant differences of the cystatin C values between any of the compared groups. ROC analysis showed at least one tie between the positive actual state group (AD) and the negative actual state group (ND) by CSF cystatin C and at least one tie between the positive actual state group and the negative actual state group by CSF tau protein. Our study confirmed previously reported results only in part. While tau protein seems to be quite a reliable marker of AD, the role of beta-amyloid(1-42) and cystatin C in AD diagnosis remains at least questionable.

    Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2009;30;1;1-7

  • 5'-Upstream variants of CRHR1 and MAPT genes associated with age at onset in progressive supranuclear palsy and cortical basal degeneration.

    Cruchaga C, Vidal-Taboada JM, Ezquerra M, Lorenzo E, Martinez-Lage P, Blazquez M, Tolosa E, Iberian Atypical Parkinsonism Study Group Researchers and Pastor P

    Neurogenetics Laboratory, Division of Neurosciences, Center for Applied Medical Research, University of Navarra, Pamplona, Spain.

    Two different H1 sub-haplotypes at chromosome 17q21, H1C and H1E'A, have been associated with progressive supranuclear palsy (PSP) and cortical basal degeneration (CBD). We analyzed the SNPs included in the H1C and H1E'A haplotypes in a large Spanish PSP/CBD series and their interaction with age at onset (AAO). Survival analysis of rs1880753 marker was consistently associated with disease risk and with an earlier age at onset under an additive model. Its location at 160 kb and 50 kb upstream of tau and CRHR1 genes, respectively, suggests that it might act as a cis-element that regulates gene expression. Rs45502095(H1) was also associated with AAO under a recessive model. Haplotype analysis failed to replicate the association of H1C and H1E'A haplotypes with PSP/CBD. However, we found a strong association of two H1 sub-haplotypes with PSP and CBD (H1E'C and H1Q), which include MAPT and CRHR1 genes where the risk variant for PSP/CBD could lie.

    Neurobiology of disease 2009;33;2;164-70

  • Assessment of Alzheimer's disease case-control associations using family-based methods.

    Schjeide BM, McQueen MB, Mullin K, DiVito J, Hogan MF, Parkinson M, Hooli B, Lange C, Blacker D, Tanzi RE and Bertram L

    MassGeneral Institute for Neurodegenerative Disease (MIND), Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA.

    The genetics of Alzheimer's disease (AD) is heterogeneous and remains only ill-defined. We have recently created a freely available and continuously updated online database (AlzGene; http://www.alzgene.org ) for which we collect all published genetic association studies in AD and perform systematic meta-analyses on all polymorphisms with sufficient genotype data. In this study, we tested 27 genes (ACE, BDNF, CH25H, CHRNB2, CST3, CTSD, DAPK1, GALP, hCG2039140, IL1B, LMNA, LOC439999, LOC651924, MAPT, MTHFR, MYH13, PCK1, PGBD1, PRNP, PSEN1, SORCS1, SORL1, TF, TFAM, TNK1, GWA_14q32.13, and GWA_7p15.2), all showing significant association with AD risk in the AlzGene meta-analyses, in a large collection of family-based samples comprised of 4,180 subjects from over 1,300 pedigrees. Overall, we observe significant association with risk for AD and polymorphisms in ACE, CHRNB2, TF, and an as yet uncharacterized locus on chromosome 7p15.2 [rs1859849]. For all four loci, the association was observed with the same alleles as in the AlzGene meta-analyses. The convergence of case-control and family-based findings suggests that these loci currently represent the most promising AD gene candidates. Further fine-mapping and functional analyses are warranted to elucidate the potential biochemical mechanisms and epidemiological relevance of these genes.

    Funded by: NIA NIH HHS: P01 AG015379, P01 AG015379-110008, U24 AG021886; NICHD NIH HHS: R01 HD060726; NIMH NIH HHS: R37 MH060009, R37 MH060009-10

    Neurogenetics 2009;10;1;19-25

  • Hyperphosphorylated tau aggregates in the cortex and hippocampus of transgenic mice with mutant human FTDP-17 Tau and lacking the PARK2 gene.

    Guerrero R, Navarro P, Gallego E, Garcia-Cabrero AM, Avila J and Sanchez MP

    Laboratory of Neurology, Fundacion Jimenez Diaz-Capio/Clinica Ntra. Sra. Concepción, Avda Reyes Catolicos 2, 28040 Madrid, Spain. rguerrero@fjd.es

    Mutations in the PARK2 gene encoding parkin cause autosomal recessive juvenile parkinsonism, but have also been found in patients diagnosed with certain tauopathies. Conversely, mutations in the MAPT gene encoding tau are present in some types of parkinsonism. In order to investigate the possible relationship between these two proteins, we generated a double mutant mouse that is deficient in PARK2 and that over-expresses the hTauVLW transgene, a mutant form of the tau protein present in FTDP-17. Independent deletion of PARK2 or over-expression of the hTauVLW transgene produces mild phenotypic alterations, while a substantial increase in parkin expression is observed in hTauVLW transgenic mice. However, double mutant mice present memory and exploratory deficits, and accumulation of PHF-1 and AT8 hyperphosphorylated tau epitopes in neurons. These phenomena are coupled with reactive astrocytosis, DNA fragmentation, and variable cerebral atrophy. Here, we show that cortical and hippocampal neurons of double mutant mice develop argyrophilic Gallyas-Braak aggregates of phosphorylated tau from 3 months of age. Their number decreases in old animals. Moreover, numerous phosphorylated tau aggregates were identified with the conformation-dependent Alz-50 antibody and the S-Thioflavin staining. Ventral motor nuclei of the spinal cord also present Alz-50, AT8, and PHF1 hyperphosphorylated tau aggregates when parkin is deleted in mice over-expressing the hTauVLW transgene, begining at early ages. Thus, the combination of PARK2 gene deletion with hTauVLW over-expression in mice produces abnormal hyperphosphorylated tau aggregates, similar to those observed in the brain of patients diagnosed with certain tauopathies. In the light of these changes, these mice may help to understand the molecular processes responsible for these diseases, and they may aid the development of new therapeutic strategies to treat neurodegenerative diseases related to tau and parkin proteins.

    Acta neuropathologica 2009;117;2;159-68

  • Reduced early hypoxic/ischemic brain damage is associated with increased GLT-1 levels in mice expressing mutant (P301L) human tau.

    Liao G, Zhou M, Cheung S, Galeano J, Nguyen N, Baudry M and Bi X

    Department of Basic Medical Sciences, COMP, Western University of Health Sciences, Pomona, CA 91766-1854, USA.

    Mutations in tau proteins are associated with a group of neurodegenerative diseases, termed tauopathies. To investigate whether over-expressing human tau with P301L mutation also affects stroke-induced brain damage, we performed hypoxia/ischemia (H/I) in young adult P301L tau transgenic mice. Surprisingly, brain infarct volume was significantly smaller in transgenic mice compared to wild-type mice 24 h after H/I induction. TUNEL staining also revealed less brain apoptosis in transgenic mice following H/I. H/I resulted in a significant increase in tau fragments generated by caspase activation and a marked decrease in tau phosphorylation at residue T231 in cortex of wild-type but not transgenic mice. Activation of calpain and caspase-3 following H/I was also reduced in transgenic compared to wild-type mice, as reflected by lower levels of the specific spectrin breakdown products generated by calpain or caspase-3. Finally, basal levels of the glial glutamate transporter, GLT-1, were higher in brains of transgenic as compared to wild-type mice. These results support the idea that enhanced levels of GLT-1 in transgenic mice are responsible for reducing H/I-induced brain damage by decreasing extracellular glutamate accumulation and subsequent calpain and caspase activation.

    Funded by: NINDS NIH HHS: NS048423, NS048521, R01 NS048423, R01 NS048423-03, R01 NS048521

    Brain research 2009;1247;159-70

  • Dissociation of tau toxicity and phosphorylation: role of GSK-3beta, MARK and Cdk5 in a Drosophila model.

    Chatterjee S, Sang TK, Lawless GM and Jackson GR

    Department of Neurology, Neurogenetics and Movement Disorders Programs, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.

    Hyperphosphorylation of tau at multiple sites has been implicated in the formation of neurofibrillary tangles in Alzheimer's disease; however, the relationship between toxicity and phosphorylation of tau has not been clearly elucidated. Putative tau kinases that play a role in such phosphorylation events include the proline-directed kinases glycogen synthase kinase-3beta (GSK-3beta) and cyclin-dependent kinase 5 (Cdk5), as well as nonproline-directed kinases such as microtubule affinity-regulating kinase (MARK)/PAR-1; however, whether the cascade of events linking tau phosphorylation and neurodegeneration involves sequential action of kinases as opposed to parallel pathways is still a matter of controversy. Here, we employed a well-characterized Drosophila model of tauopathy to investigate the interdependence of tau kinases in regulating the phosphorylation and toxicity of tau in vivo. We found that tau mutants resistant to phosphorylation by MARK/PAR-1 were indeed less toxic than wild-type tau; however, this was not due to their resistance to phosphorylation by GSK-3beta/Shaggy. On the contrary, a tau mutant resistant to phosphorylation by GSK-3beta/Shaggy retained substantial toxicity and was found to have increased affinity for microtubules compared with wild-type tau. The fly homologs of Cdk5/p35 did not have major effects on tau toxicity or phosphorylation in this model. These data suggest that, in addition to tau phosphorylation, microtubule binding plays a crucial role in the regulation of tau toxicity when misexpressed. These data have important implications for the understanding and interpretation of animal models of tauopathy.

    Funded by: NIA NIH HHS: AG016570; NINDS NIH HHS: NS046489, R01 NS046489

    Human molecular genetics 2009;18;1;164-77

  • Cluster analysis of risk factor genetic polymorphisms in Alzheimer's disease.

    Randall CN, Strasburger D, Prozonic J, Morris SN, Winkie AD, Parker GR, Cheng D, Fennell EM, Lanham I, Vakil N, Huang J, Cathcart H, Huang R and Poduslo SE

    Institute of Molecular Medicine and Genetics (IMMAG), Medical College of Georgia, 1120 15th Street, Augusta, GA, 30912, USA.

    Multiple genetic variants may contribute to the risk of developing Alzheimer's disease. We have analyzed polymorphisms in 9 genes to determine whether particular combinations would contribute to this risk. The genes were APOE, LDLr, CST3, CTSD, TNF, BACE1, MAPT, STH, eNOS, and TFCP2. Three risk groups for the disease were identified. Risk group I was younger, was heterozygous for the CST3 (GA), CTSD2936 (AG), TNF -308 (AG) genetic variants. Risk group II was older, was homozygous for the -427 APOE promoter polymorphism (TT), and heterozygous for the MAPT deletion and for the STH variant (QR). Group III had both the youngest and oldest subjects, were heterozygous for the -863 (AC) and -1031 (CT) TNF promoter polymorphisms. All three groups carried the APOE 4 allele and were heterozygous for both BACE1 polymorphisms. The control groups were carriers of the APOE 3 allele and were homozygous for the BACE1 genetic variants.

    Neurochemical research 2009;34;1;23-8

  • FTDP-17 missense mutations site-specifically inhibit as well as promote dephosphorylation of microtubule-associated protein tau by protein phosphatases of HEK-293 cell extract.

    Han D and Paudel HK

    Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec, Canada.

    FTDP-17 missense tau mutations: G272V, P301L, V337M and R406W promote tau phosphorylation in human and transgenic mice brains by interfering with the tau phosphorylation/dephosphorylation balance. The effect of FTDP-17 mutations on tau phosphorylation by different kinases has been studied previously. However, it is not known how various FTDP-17 mutations affect tau dephosphorylation by phosphoprotein phosphatases. In this study we have observed that when transfected into HEK-293 cells, tau is phosphorylated on various sites that are also phosphorylated in diseased human brains. When transfected cells are lysed and incubated, endogenously phosphorylated tau is dephosphorylated by cellular protein phosphatase 1 (PP1), phosphatase 2A (PP2A) and phosphatase 2B (PP2B), which are also present in the lysate. By using this assay and specific inhibitors of PP1, PP2A and PP2B, we have observed that the G272V mutation promotes tau dephosphorylation by PP2A at Ser(396/404), Ser(235), Thr(231), Ser(202/205) and Ser(214) and by PP2B at Ser(214) but inhibits dephosphorylation by PP2B at Ser(396/404). The P301L mutation promotes tau dephosphorylation at Thr(231) by PP1 and at Ser(396/404), Thr(231), Ser(235) and Ser(202/205) by PP2A but inhibits dephosphorylation at Ser(214) by PP2B. The V337M mutation promotes tau dephosphorylation at Ser(235), Thr(231) and Ser(202/205) by PP2A and at Ser(202/205) by PP2B whereas the R406W mutation promotes tau dephosphorylation at Ser(396/404) by PP1, PP2A and PP2B but inhibits dephosphorylation at Ser(202/205) and Ser(235) by PP1 and PP2A, respectively. Our results indicate that each FTDP-17 tau mutation not only site-specifically inhibits tau dephosphorylation on some sites but also promotes dephosphorylation by phosphatases on other sites.

    Neurochemistry international 2009;54;1;14-27

  • Genomewide association study for susceptibility genes contributing to familial Parkinson disease.

    Pankratz N, Wilk JB, Latourelle JC, DeStefano AL, Halter C, Pugh EW, Doheny KF, Gusella JF, Nichols WC, Foroud T, Myers RH and PSG-PROGENI and GenePD Investigators, Coordinators and Molecular Genetic Laboratories

    Indiana University School of Medicine, Health Information and Translational Sciences Building, Indianapolis, IN 46202-3002, USA. npankrat@iupui.edu

    Five genes have been identified that contribute to Mendelian forms of Parkinson disease (PD); however, mutations have been found in fewer than 5% of patients, suggesting that additional genes contribute to disease risk. Unlike previous studies that focused primarily on sporadic PD, we have performed the first genomewide association study (GWAS) in familial PD. Genotyping was performed with the Illumina HumanCNV370Duo array in 857 familial PD cases and 867 controls. A logistic model was employed to test for association under additive and recessive modes of inheritance after adjusting for gender and age. No result met genomewide significance based on a conservative Bonferroni correction. The strongest association result was with SNPs in the GAK/DGKQ region on chromosome 4 (additive model: p = 3.4 x 10(-6); OR = 1.69). Consistent evidence of association was also observed to the chromosomal regions containing SNCA (additive model: p = 5.5 x 10(-5); OR = 1.35) and MAPT (recessive model: p = 2.0 x 10(-5); OR = 0.56). Both of these genes have been implicated previously in PD susceptibility; however, neither was identified in previous GWAS studies of PD. Meta-analysis was performed using data from a previous case-control GWAS, and yielded improved p values for several regions, including GAK/DGKQ (additive model: p = 2.5 x 10(-7)) and the MAPT region (recessive model: p = 9.8 x 10(-6); additive model: p = 4.8 x 10(-5)). These data suggest the identification of new susceptibility alleles for PD in the GAK/DGKQ region, and also provide further support for the role of SNCA and MAPT in PD susceptibility.

    Funded by: NINDS NIH HHS: R01 NS036711, R01 NS036711-09, R01 NS037167-10, R01 NS37167; PHS HHS: HHSN268200782096C; Telethon: GTB07001

    Human genetics 2009;124;6;593-605

  • Parkin attenuates wild-type tau modification in the presence of beta-amyloid and alpha-synuclein.

    Moussa CE

    Department of Biochemistry, Molecular and Cell Biology, Georgetown University Medical Center, The New Research Building, Room WP26B, 3970 Reservoir Rd, NW., Washington, DC 20007, USA. cem46@georgetown.edu

    Changes in tau (tau) metabolism comprise important pathological landmarks in the tauopathies with parkinsonism as well as Parkinson's disease and Alzheimer's disease. Mutations in the parkin gene are associated with Parkinson's disease. Deposits of amyloid proteins, including Abeta and alpha-synuclein coexist in the brains of patients with dementia with Lewy bodies; however, it is not known how either of them interacts with tau to provoke neurofibrillary tangle formation across the tauopathies. Here, we show a role for parkin against tau pathology in the presence of intracellular Abeta or alpha-synuclein. Parkin attenuates four-repeat human tau, but not mutant P301L, hyperphosphorylation in the presence of intracellular Abeta(1-42), or alpha-synuclein and decreases GSK-3beta activity in amyloid-stressed M17 human neuroblastoma cells. These data suggest that parkin may counteract the alteration of tau metabolism in certain neurodegenerative diseases with tau cytopathy and parkinsonism.

    Journal of molecular neuroscience : MN 2009;37;1;25-36

  • Exonic point mutations of human tau enhance its toxicity and cause characteristic changes in neuronal morphology, tau distribution and tau phosphorylation in the lamprey cellular model of tauopathy.

    Lee S, Jung C, Lee G and Hall GF

    Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA.

    Exonic mutations in the gene coding for human tau cause familial neurofibrillary degenerative diseases (tauopathies) which exhibit mutation-specific characteristics. It is thus unclear whether such mutations have similar effects on tau structure and function in vivo and if they act via similar cytopathological mechanisms in vulnerable neuron types. We have previously shown that overexpressing wild type human tau isoforms in identified giant neurons (ABCs) of the lamprey CNS results in characteristic, stereotyped cytopathological changes in these cells over several weeks. Here, we use this model to compare the cytopathological consequences of expressing wild type and exonic mutant tau isoforms (P301L, G272V, V337M, and R406W) at a high level of resolution. We show that each of the four exonic htau mutations tested accelerate degeneration in ABCs when compared to their WT parent isoforms, and that the patterns of human tau distribution, phosphorylation and cytopathology, while similar, vary characteristically from one another among both WT and mutant isoforms in a single identified neuron in situ. Our results therefore suggest that at least some of the differences between the effects of these mutations in humans are due to cell autonomous, mutation specific differences in the cytopathological mechanism of tau-induced neurodegeneration.

    Funded by: NIA NIH HHS: R01AG13919, R44AG01881

    Journal of Alzheimer's disease : JAD 2009;16;1;99-111

  • Genetic interaction between tau and the apolipoprotein E receptor LRP1 Increases Alzheimer's disease risk.

    Vázquez-Higuera JL, Mateo I, Sánchez-Juan P, Rodríguez-Rodríguez E, Pozueta A, Infante J, Berciano J and Combarros O

    Neurology Service and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), University Hospital Marqués de Valdecilla (University of Cantabria), Santander, Spain.

    Abnormal tau hyperphosphorylation is one of the central events in the development of neurofibrillary tangles (NFTs) in Alzheimer's disease (AD), and phosphorylation of tau is accelerated by the increase in the level of neuronal cholesterol. Apolipoprotein E (APOE) promotes the neuronal uptake of cholesterol via APOE receptors such as the low-density lipoprotein receptor-related protein 1 (LRP1), and the APOE epsilon4 allele is associated with an increase in NFT burden in AD brain. In a case-control study in 246 AD patients and 237 healthy controls, we examined whether the combined gene effects between tau (intron 9, rs2471738) polymorphism and LRP1 (exon 3, rs1799986) polymorphism might be responsible for susceptibility to AD, independently or in concert with the APOE epsilon4 allele. Subjects carrying both the tau (intron 9, rs2471738) T allele (CT and TT genotypes) and the LRP1 (exon 3, rs1799986) T allele (CT and TT genotypes) had a 6 times higher risk of developing AD than subjects without these risk genotypes (odds ration = 6.20, 95% confidence interval = 1.74-22.05, p = 0.005), and this genetic interaction was observed in either the presence or the absence of the APOE epsilon4 allele. These data suggest that the synergistic effects (epistasis) between tau and LRP1 might modify the risk of AD in an APOE epsilon4 allele-independent fashion.

    Dementia and geriatric cognitive disorders 2009;28;2;116-20

  • No evidence of PGRN or MAPT gene dosage alterations in a collection of patients with frontotemporal lobar degeneration.

    Skoglund L, Ingvast S, Matsui T, Freeman SH, Frosch MP, Brundin R, Giedraitis V, Growdon JH, Hyman BT, Lannfelt L, Ingelsson M and Glaser A

    Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden. Lena.Skoglund@pubcare.uu.se

    Alterations in gene dosage have recently been associated with neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, and deletions of the progranulin (PGRN) locus were recently described in patients with frontotemporal lobar degeneration (FTLD). FTLD is a genetically complex neurodegenerative disorder with mutations in the PGRN and the microtubule-associated protein tau (MAPT) genes being the most common known causes of familial FTLD. In this study, we investigated 39 patients with FTLD, previously found negative for mutations in PGRN and MAPT, for copy number alterations of these 2 genes.

    Methods: Gene dosage analysis of PGRN and MAPT was performed using multiplex ligation-dependent probe amplification.

    Results: We did not identify any PGRN or MAPT gene dosage variations in the 39 FTLD patients investigated.

    Conclusion: We therefore conclude that alterations in gene copy number of PGRN and MAPT are not a cause of disease in this collection of FTLD patients.

    Funded by: NIA NIH HHS: P50 AG005134

    Dementia and geriatric cognitive disorders 2009;28;5;471-5

  • Total-tau and phospho-tau(181Thr) in cerebrospinal fluid of neurologically intact population increase with age.

    Jaworski J, Psujek M and Bartosik-Psujek H

    Department of Neurology, Medical University of Lublin, Lublin, Poland. jjawor@onet.eu

    Tau protein is a microtubule-associated molecule playing a crucial role in maintenance of neuronal integrity and in many neurodegenerative processes; its pathology has become a hallmark feature at the tissue level. The aim of the study was to estimate total tau and phospho-tau (Thr181) concentrations in cerebrospinal fluid of healthy population. Cerebrospinal fluid samples were taken from 129 subjects (age 18-77 years) without known neurologic or psychiatric condition. Both total-tau and phospho-tau levels showed significant correlation with age, which was more pronounced in older population.

    Folia biologica 2009;55;4;126-31

  • FTDP-17 mutations in Tau alter the regulation of microtubule dynamics: an "alternative core" model for normal and pathological Tau action.

    LeBoeuf AC, Levy SF, Gaylord M, Bhattacharya A, Singh AK, Jordan MA, Wilson L and Feinstein SC

    Neuroscience Research Institute and Department of Molecular and Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.

    Mutations affecting either the structure or regulation of the microtubule-associated protein Tau cause neuronal cell death and dementia. However, the molecular mechanisms mediating these deleterious effects remain unclear. Among the most characterized activities of Tau is the ability to regulate microtubule dynamics, known to be essential for proper cell function and viability. Here we have tested the hypothesis that Tau mutations causing neurodegeneration also alter the ability of Tau to regulate the dynamic instability behaviors of microtubules. Using in vitro microtubule dynamics assays to assess average microtubule growth rates, microtubule growth rate distributions, and catastrophe frequencies, we found that all tested mutants possessing amino acid substitutions or deletions mapping to either the repeat or interrepeat regions of Tau do indeed compromise its ability to regulate microtubule dynamics. Further mutational analyses suggest a novel mechanism of Tau regulatory action based on an "alternative core" of microtubule binding and regulatory activities composed of two repeats and the interrepeat between them. In this model, the interrepeat serves as the primary regulator of microtubule dynamics, whereas the flanking repeats serve as tethers to properly position the interrepeat on the microtubule. Importantly, since there are multiple interrepeats on each Tau molecule, there are also multiple cores on each Tau molecule, each with distinct mechanistic capabilities, thereby providing significant regulatory potential. Taken together, the data are consistent with a microtubule misregulation mechanism for Tau-mediated neuronal cell death and provide a novel mechanistic model for normal and pathological Tau action.

    Funded by: Howard Hughes Medical Institute; NCI NIH HHS: CA-57291; NINDS NIH HHS: NS-13560, NS-35010

    The Journal of biological chemistry 2008;283;52;36406-15

  • Tau isoform regulation is region- and cell-specific in mouse brain.

    McMillan P, Korvatska E, Poorkaj P, Evstafjeva Z, Robinson L, Greenup L, Leverenz J, Schellenberg GD and D'Souza I

    Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington 98195, USA.

    Tau is a microtubule-associated protein implicated in neurodegenerative tauopathies. Alternative splicing of the tau gene (MAPT) generates six tau isoforms, distinguishable by the exclusion or inclusion of a repeat region of exon 10, which are referred to as 3-repeat (3R) and 4-repeat (4R) tau, respectively. We developed transgenic mouse models that express the entire human MAPT gene in the presence and absence of the mouse Mapt gene and compared the expression and regulation of mouse and human tau isoforms during development and in the young adult. We found differences between mouse and human tau in the regulation of exon 10 inclusion. Despite these differences, the isoform splicing pattern seen in normal human brain is replicated in our mouse models. In addition, we found that all tau, both in the neonate and young adult, is phosphorylated. We also examined the normal anatomic distribution of mouse and human tau isoforms in mouse brain. We observed developmental and species-specific variations in the expression of 3R- and 4R-tau within the frontal cortex and hippocampus. In addition, there were differences in the cellular distribution of the isoforms. Mice transgenic for the human MAPT gene exhibited higher levels of neuronal cell body expression of tau compared to wildtype mice. This neuronal cell body expression of tau was limited to the 3R isoform, whereas expression of 4R-tau was more "synaptic like," with granular staining of neuropil rather than in neuronal cell bodies. These developmental and species-specific differences in the regulation and distribution of tau isoforms may be important to the understanding of normal and pathologic tau isoform expression.

    Funded by: NIA NIH HHS: P01 AG017586-09, P01 AG17586, P50 AG005136-25, R37 AG011762-10, R37 AG11762-10

    The Journal of comparative neurology 2008;511;6;788-803

  • Lack of association of APOE and tau polymorphisms with dementia in Parkinson's disease.

    Ezquerra M, Campdelacreu J, Gaig C, Compta Y, Muñoz E, Martí MJ, Valldeoriola F and Tolosa E

    Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències, Hospital Clínic de Barcelona, Department of Medicine, Universitat de Barcelona, IDIBAPS, CIBERNED, Barcelona, Spain.

    Some APOE or tau gene polymorphisms have been associated with Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and Parkinson's disease (PD). The reports of a possible association between the APOE 4 allele and dementia in PD are controversial, and some studies suggest that the tau H1/H1 genotype may increase the risk of dementia in PD. Here we analysed these APOE and tau polymorphisms in 86 clinically diagnosed PD patients with dementia (PDD), in 138 clinically diagnosed non-demented PD (PDND) patients, and in 91 healthy controls. Genomic DNA isolated from blood was used for PCR and subsequent RFLP analysis. We examined the possible genetic association of these polymorphisms with dementia in PD, but found no differences in genotypic distributions between the PDND, PDD, and control groups. The effects of tau and APOE polymorphisms on the age at dementia onset were studied using Kaplan-Meier survival analysis but no significant association were found. The lack of association between the APOE 4 allele and PDD suggests that the pathological process involved in the development of dementia in PD is different from the one that occurs in AD.

    Neuroscience letters 2008;448;1;20-3

  • Role of MAPT mutations and haplotype in frontotemporal lobar degeneration in Northern Finland.

    Kaivorinne AL, Krüger J, Kuivaniemi K, Tuominen H, Moilanen V, Majamaa K and Remes AM

    Department of Neurology, University of Oulu, Oulu, Finland. annalott@mail.student.oulu.fi

    Background: Frontotemporal lobar degeneration (FTLD) consists of a clinically and neuropathologically heterogeneous group of syndromes affecting the frontal and temporal lobes of the brain. Mutations in microtubule-associated protein tau (MAPT), progranulin (PGRN) and charged multi-vesicular body protein 2B (CHMP2B) are associated with familial forms of the disease. The prevalence of these mutations varies between populations. The H1 haplotype of MAPT has been found to be closely associated with tauopathies and with sporadic FTLD. Our aim was to investigate MAPT mutations and haplotype frequencies in a clinical series of patients with FTLD in Northern Finland.

    Methods: MAPT exons 1, 2 and 9-13 were sequenced in 59 patients with FTLD, and MAPT haplotypes were analysed in these patients, 122 patients with early onset Alzheimer's disease (eoAD) and 198 healthy controls.

    Results: No pathogenic mutations were found. The H2 allele frequency was 11.0% (P = 0.028) in the FTLD patients, 9.8% (P = 0.029) in the eoAD patients and 5.3% in the controls. The H2 allele was especially clustered in patients with a positive family history (P = 0.011) but did not lower the age at onset of the disease. The ApoE4 allele frequency was significantly increased in the patients with eoAD and in those with FTLD.

    Conclusion: We conclude that although pathogenic MAPT mutations are rare in Northern Finland, the MAPT H2 allele may be associated with increased risks of FTLD and eoAD in the Finnish population.

    BMC neurology 2008;8;48

  • The PSP-associated MAPT H1 subhaplotype in Guadeloupean atypical parkinsonism.

    Camuzat A, Romana M, Dürr A, Feingold J, Brice A, Ruberg M and Lannuzel A

    INSERM, UMR_S 679, Neurology and Experimental Therapeutics, Paris, France.

    The aim of this study was to determine whether the H1 subhaplotype in MAPT associated with progressive supranuclear palsy (PSP) in Caucasians confers risk for PSP-like atypical parkinsonism in Guadeloupe, a tauopathy. Guadeloupean controls and patients with atypical and idiopathic parkinsonism and ethnically and age-matched controls were genotyped for H1 and H2 alleles, then for the H1 subhaplotype associated with PSP in Caucasians, using previously described haplotype-tagging single nucleotide polymorphisms (Ht-SNPs) in linkage disequilibrium at the MAPT locus. Most Guadeloupean controls and patients were homozygous for the H1 allele; only 5% were heterozygous for the H2 allele, consistent with the European contribution to the racial admixture in Guadeloupe, but equivalent to the frequency found in Caucasian PSP patients. The frequencies of the Ht-SNPs used to determine the PSP-associated H1 subhaplotype in both Guadeloupean controls and parkinsonians were similar, indicating that the H1 subhaplotype associated with PSP in Caucasians was not a risk factor for PSP-like atypical parkinsonism in Guadeloupe. Interestingly, they were also similar to the frequencies in Caucasian PSP patients. The major H1 subhaplotype in Guadeloupe, determined by analysis of linkage desequibrium, differed from the major Caucasian subhaplotype, but corresponded to minor alleles previously described.

    Movement disorders : official journal of the Movement Disorder Society 2008;23;16;2384-91

  • Cerebrospinal fluid levels of tau phosphorylated at threonine 181 in patients with Alzheimer's disease and vascular dementia.

    Ravaglia S, Bini P, Sinforiani E, Franciotta D, Zardini E, Tosca P, Moglia A and Costa A

    Department of Behavioral Neurology, Institute of Neurology IRCCS C. Mondino, Via Mondino 2, 27100, Pavia, Italy. sabrina.ravaglia@mondino.it

    In 31 patients with probable Alzheimer's disease (AD), 19 with probable vascular dementia (VaD) and 20 with Possible AD and Possible VaD, cerebrospinal fluid (CSF) tau levels hyperphosphorylated at threonine 181 (Ptau) were measured by ELISA. Thirty-six age-matched subjects were used as controls. The severity of the cognitive decline was assessed at the time of CSF analysis and after a 12-month follow-up. The groups had comparable age, degree of cognitive impairment and disease duration; these parameters were not related to P-tau levels. P-tau discriminated between demented patients and controls, but no significant difference emerged between AD and the other groups. By contrast, higher P-tau values were found to predict, independently of the clinical diagnosis, a more rapid evolution of cognitive decline. Whether these findings are due to a lack of CSF P-tau specificity or to the low reliability of clinical and radiological criteria remains unclear. P-tau may be useful in the evaluation of disease evolution, by predicting the rate of cognitive decline.

    Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2008;29;6;417-23

  • Enduring involvement of tau, beta-amyloid, alpha-synuclein, ubiquitin and TDP-43 pathology in the amyotrophic lateral sclerosis/parkinsonism-dementia complex of Guam (ALS/PDC).

    Miklossy J, Steele JC, Yu S, McCall S, Sandberg G, McGeer EG and McGeer PL

    Kinsmen Laboratory of Neurological Research, The University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada.

    Guam ALS/PDC is a severe tangle forming disorder endemic to Guam with features overlapping such neurodegenerative disorders as Alzheimer disease (AD), Parkinson disease (PD), progressive supranuclear palsy (PSP), ALS, corticobasal degeneration (CBD) and pallido-ponto-nigral degeneration (PPND). Since the prevalence is declining, we examined brain tissue from 35 clinically diagnosed Chamorro patients with ALS/PDC and two Chamorro controls autopsied between 1946 and 2006, to determine if distinct variations in the pathology could be identified up to this time. Although the age at autopsy increased by 4.5-5 years per decade, we identified no qualitative differences in pathological deposits with antibodies against tau, ubiquitin, A beta, alpha-synuclein and TDP-43, indicating that these more recently identified proteins have been involved in the neuropathogenesis over the past 6 decades. Tau and TDP-43 positive neuronal, oligodendroglial and astrocytic inclusions involving multiple nerve fiber tracts occurred in both the ALS and PDC types, reinforcing the concept that these forms are part of the same disorder. The results obtained may help to define the commonality of the Guam disease with other tangle forming disorders and may help in monitoring the epidemiological changes that are taking place.

    Acta neuropathologica 2008;116;6;625-37

  • Haplotype-specific expression of the N-terminal exons 2 and 3 at the human MAPT locus.

    Caffrey TM, Joachim C and Wade-Martins R

    The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.

    The microtubule-associated protein tau (MAPT) H1 haplotype shows a strong association to the sporadic neurodegenerative diseases, progressive supranuclear palsy and corticobasal degeneration. The functional biological mechanisms behind the genetic association have started to emerge with differences recently shown in haplotype splicing of the neuropathologically relevant exon 10. Here we investigate the hypothesis that expression of the alternatively spliced N-terminal exons also differs between the two MAPT haplotypes. We performed allele-specific gene expression analysis on a H1/H2 heterozygous human neuronal cell line model and 14 H1/H2 heterozygous human post-mortem brain tissues from two brain regions. In both cell culture and post-mortem brain tissue, we show that the protective MAPT H2 haplotype significantly expresses two-fold more 2N (exons 2+3+) MAPT transcripts than the disease-associated H1 haplotype. We suggest that inclusion of exon 3 in MAPT transcripts may contribute to protecting H2 carries from neurodegeneration.

    Funded by: Wellcome Trust: 073141

    Neurobiology of aging 2008;29;12;1923-9

  • Tau protein, phosphorylated tau protein and beta-amyloid42 in the cerebrospinal fluid of multiple sclerosis patients.

    Valis M, Talab R, Stourac P, Andrys C and Masopust J

    Department of Neurology, Medical Faculty, Charles University and Teaching Hospital in Hradec Králové, Czech Republic.

    Objectives: The presented study focuses on the importance of measurement of beta-amyloid42 (Abeta-42) levels, total tau protein, and phosphorylated tau (p-tau) protein in the cerebrospinal fluid (CSF) of cerebrospinal multiple sclerosis (MS) and clinically isolated syndrome (CIS) which represents an early phase of multiple sclerosis.

    Methods: A total of 23 patients with clinically isolated syndrome and suspected MS were enrolled into the study. Of this number, 14 patients met the criteria for definitive MS according to McDonald. The control group consisted of 40 patients examined for the possibility of organic damage to the brain, which was not confirmed. We used method of enzyme immunoanalysis to examine concentrations of tau protein, p- tau protein, and beta amyloid42. Differences between the respective groups were examined by test statistics. In addition, dependence of the total tau protein, p-tau protein, and beta-amyloid42 levels on demographic variables, diagnosis and duration of disease was examined by correlation analysis. Correlation of the concentrations obtained in the measurements was evaluated based on the calculated correlation coefficient (r) and level of significance (p).

    Results: Compared to the control group, no statistically significant difference was found in the levels of tau protein and p-tau protein between the CIS group and definitive MS group. A significant increase was found only for beta-amyloid42 levels in patients with diagnosed MS vs. control group. We demonstrated no correlation between the beta-amyloid42 and tau protein levels, p-tau protein and age of patients and duration of disease in patients with MS, CIS and the control group.

    Conclusion: Results of our study show that use of tau protein, p-tau protein and beta-amyloid42 in the diagnosis of multiple sclerosis seems to be non-beneficial. We confirmed no importance for the differential diagnosis of an early stage MS.

    Neuro endocrinology letters 2008;29;6;971-6

  • Tau forms in CSF as a reliable biomarker for progressive supranuclear palsy.

    Borroni B, Malinverno M, Gardoni F, Alberici A, Parnetti L, Premi E, Bonuccelli U, Grassi M, Perani D, Calabresi P, Di Luca M and Padovani A

    Centre for Aging Brain and Dementia, Department of Neurology, University of Brescia, Italy.

    Objective: In CSF, extended (55 kDa) and truncated (33 kDa) tau forms have been previously recognized, and the tau 33 kDa/55 kDa ratio has been found significantly reduced in progressive supranuclear palsy (PSP) vs in other neurodegenerative disorders. The aim of this study was to evaluate the diagnostic value of the CSF tau form ratio as a biomarker of PSP and to correlate the structural anatomic changes as measured by means of voxel-based morphometry (VBM) to CSF tau form ratio decrease.

    Methods: A total of 166 subjects were included in the study (21 PSP, 20 corticobasal degeneration syndrome, 44 frontotemporal dementia, 29 Alzheimer disease, 10 Parkinson disease, 15 dementia with Lewy bodies, and 27 individuals without any neurodegenerative disorder). Each patient underwent a standardized clinical and neuropsychological evaluation. In CSF, a semiquantitative immunoprecipitation was developed to evaluate CSF tau 33 kDa/55 kDa ratio. MRI assessment and VBM analysis was carried out.

    Results: Tau form ratio was significantly reduced in patients with PSP (0.504 +/- 0.284) when compared to age-matched controls (0.989 +/- 0.343), and to patients with other neurodegenerative conditions (range = 0.899-1.215). The area under the curve (AUC) of the receiver operating characteristic analysis in PSP vs other subgroups ranged from 0.863 to 0.937 (PSP vs others, AUC = 0.897, p < 0.0001). VBM study showed that CSF tau form ratio decrease correlated significantly with brainstem atrophy.

    Conclusions: Truncated tau production, which selectively affects brainstem neuron susceptibility, can be considered a specific and reliable marker for PSP. Tau form ratio was the lowest in progressive supranuclear palsy with no overlap with any other neurodegenerative illness.

    Neurology 2008;71;22;1796-803

  • CSF total and phosphorylated tau protein, regional glucose metabolism and dementia severity in Alzheimer's disease.

    Haense C, Buerger K, Kalbe E, Drzezga A, Teipel SJ, Markiewicz P, Herholz K, Heiss WD and Hampel H

    Max Planck Institute for Neurological Research, Cologne, Germany. haense@nf.mpg.de

    We investigated associations between severity of cognitive impairment, cerebrospinal fluid (CSF) concentrations of total-tau (t-tau) protein and tau phosphorylated at threonin 181 (p-tau(181)) and regional glucose metabolism measured with 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) in patients with probable Alzheimer's disease (AD).

    Methods: In 38 patients (mean age 66.5 +/- 8.0 years) with AD, Mini-Mental State Examination (MMSE) scores were evaluated and CSF levels of t-tau and p-tau(181) measured. All patients underwent an 18F-FDG-PET scan. Image analysis including correlation analysis and principal component analysis (PCA) were performed using SPM5 and VINCI.

    Results: Dementia severity (MMSE 21.2 +/- 4.9) correlated well with metabolic impairment especially in left hemisphere association areas that are typically affected in patients with AD (e.g. inferior parietal lobule, r = 0.512; medial temporal gyrus, r = 0.478; inferior temporal gyrus, r = 0.488; precuneus, r = 0.468; PCA: r = 0.639, F = 7.751; all P < 0.001). There were no associations between t-tau and p-tau(181) with dementia severity and only weak correlations between t-tau and cerebral glucose metabolism (superior parietal gyrus, r = -0.325, P < 0.05; precentral gyrus r = -0.418, P < 0.01; amygdala r = -0.362, P < 0.05). No correlations were found between p-tau(181) and regional hypometabolism in FDG-PET.

    Conclusion: MMSE and CSF t-tau represent different aspects of disease severity. Whilst MMSE is closely related to impaired cerebral glucose metabolism, CSF t-tau is less closely related and appears to be less well suited for assessment of disease progression.

    European journal of neurology 2008;15;11;1155-62

  • Pathogenic missense MAPT mutations differentially modulate tau aggregation propensity at nucleation and extension steps.

    Chang E, Kim S, Yin H, Nagaraja HN and Kuret J

    Department of Molecular and Cellular Biochemistry, Center for Molecular Neurobiology, The Ohio State University College of Medicine, Columbus, Ohio 43210, USA.

    Mutations in the MAPT gene encoding tau protein lead to neurofibrillary lesion formation, neurodegeneration, and cognitive decline associated with frontotemporal lobar degeneration. While some pathogenic mutations affect MAPT introns, resulting in abnormal splicing patterns, the majority occur in the tau coding sequence leading to single amino acid changes in tau primary structure. Depending on their location within the polypeptide chain, tau missense mutations have been reported to augment aggregation propensity. To determine the mechanisms underlying mutation-associated changes in aggregation behavior, the fibrillization of recombinant pathogenic mutants R5L, G272V, P301L, V337M, and R406W prepared in a full-length four-repeat human tau background was examined in vitro as a function of time and submicromolar tau concentrations using electron microscopy assay methods. Kinetic constants for nucleation and extension phases of aggregation were then estimated by direct measurement and mathematical simulation. Results indicated that the mutants differ from each other and from wild-type tau in their aggregation propensity. G272V and P301L mutations increased the rates of both filament nucleation and extension reactions, whereas R5L and V337M increased only the nucleation phase. R406W did not differ from wild-type in any kinetic parameter. The results show that missense mutations can directly promote tau filament formation at different stages of the aggregation pathway.

    Funded by: NCRR NIH HHS: UL1 RR025755, UL1RR025755-01; NIA NIH HHS: AG14452, R01 AG014452, R01 AG014452-10

    Journal of neurochemistry 2008;107;4;1113-23

  • Role of the tau gene region chromosome inversion in progressive supranuclear palsy, corticobasal degeneration, and related disorders.

    Webb A, Miller B, Bonasera S, Boxer A, Karydas A and Wilhelmsen KC

    Department of Biomedical Engineering, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7264, USA.

    Background: An inverted region on chromosome 17 has been previously linked to many Pick complex diseases. Due to the inversion, an exact causal locus has been difficult to identify, but the microtubule-associated protein tau gene is a likely candidate gene for its involvement in these diseases with tau inclusion.

    Objective: To search for variants that confer susceptibility to 4 tauopathies and clinically related disorders.

    Design: Genomewide association study.

    Setting: University research laboratory.

    Participants: A total of 231 samples were genotyped from an unrelated white population of patients with progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), frontotemporal dementia, and frontotemporal dementia with amyotrophy. Unaffected individuals from the same population were used as controls.

    The results from an inverted region of chromosome 17 that contains the MAPT gene. Genotypes of cases and controls were compared using a Fisher exact test on a marker-by-marker basis. Haplotypes were determined by visually inspecting genotypes.

    Results: Comparing any particular disease and controls, the association was constant across the inverted chromosome segment. Significant associations were seen for PSP and PSP combined with CBD. Of the 2 haplotypes seen in the region, H1 was overrepresented in PSP and CBD cases compared with controls.

    Conclusions: As expected, the markers are highly correlated and the association is seen across the entire region, which makes it difficult to narrow down a disease-causing variant or even a possible candidate gene. However, considering the pathologic abnormalities of these diseases and the involvement of tau mutations seen in familial forms, the MAPT gene represents the most likely cause driving the association.

    Funded by: NCI NIH HHS: P30 CA013696-259006; NCRR NIH HHS: M01 RR000083, M01 RR000083-37S10426, M01RR00079, P20 RR015587, P20 RR015587-096496, P41 RR013642, P41 RR013642-080063, P41 RR013642-097227, P41 RR013642-107076, P41 RR013642-116504; NIA NIH HHS: P01 AG019724, P01 AG019724-07, P01 AG021601, P01 AG021601-050001, P01 AG19724, P50 AG023501, P50 AG023501-040001, P50 AG023501-049001, P50 AG023501-05, P50 AG023501-050001, P50 AG023501-059001, R21 AG026043-02, T32 AG023481, T32 AG023481-04; NIDA NIH HHS: R01 DA030976; NIMH NIH HHS: K08 MH065983-05; NINDS NIH HHS: K23 NS048855-04, R01 NS036733-03, R01NS36733

    Archives of neurology 2008;65;11;1473-8

  • Increased dosage of Dyrk1A alters alternative splicing factor (ASF)-regulated alternative splicing of tau in Down syndrome.

    Shi J, Zhang T, Zhou C, Chohan MO, Gu X, Wegiel J, Zhou J, Hwang YW, Iqbal K, Grundke-Iqbal I, Gong CX and Liu F

    Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P. R. China.

    Two groups of tau, 3R- and 4R-tau, are generated by alternative splicing of tau exon 10. Normal adult human brain expresses equal levels of them. Disruption of the physiological balance is a common feature of several tauopathies. Very early in their life, individuals with Down syndrome (DS) develop Alzheimer-type tau pathology, the molecular basis for which is not fully understood. Here, we demonstrate that Dyrk1A, a kinase encoded by a gene in the DS critical region, phosphorylates alternative splicing factor (ASF) at Ser-227, Ser-234, and Ser-238, driving it into nuclear speckles and preventing it from facilitating tau exon 10 inclusion. The increased dosage of Dyrk1A in DS brain due to trisomy of chromosome 21 correlates to an increase in 3R-tau level, which on abnormal hyperphosphorylation and aggregation of tau results in neurofibrillary degeneration. Imbalance of 3R- and 4R-tau in DS brain by Dyrk1A-induced dysregulation of alternative splicing factor-mediated alternative splicing of tau exon 10 represents a novel mechanism of neurofibrillary degeneration and may help explain early onset tauopathy in individuals with DS.

    Funded by: NIA NIH HHS: AG019158, AG027429, R01 AG019158-08; NICHD NIH HHS: HD43960

    The Journal of biological chemistry 2008;283;42;28660-9

  • Parkin deletion causes cerebral and systemic amyloidosis in human mutated tau over-expressing mice.

    Rodríguez-Navarro JA, Gómez A, Rodal I, Perucho J, Martinez A, Furió V, Ampuero I, Casarejos MJ, Solano RM, de Yébenes JG and Mena MA

    Department of Neurobiology, Hospital Ramón y Cajal, Madrid, Spain.

    Deposition of proteins leading to amyloid takes place in some neurodegenerative diseases such as Alzheimer's disease and Huntington's disease. Mutations of tau and parkin proteins produce neurofibrillary abnormalities without deposition of amyloid. Here we report that mature, parkin null, over-expressing human mutated tau (PK(-/-)/Tau(VLW)) mice have altered behaviour and dopamine neurotransmission, tau pathology in brain and amyloid deposition in brain and peripheral organs. PK(-/-)/Tau(VLW) mice have abnormal behaviour and severe drop out of dopamine neurons in the ventral midbrain, up to 70%, at 12 months and abundant phosphorylated tau positive neuritic plaques, neuro-fibrillary tangles, astrogliosis, microgliosis and plaques of murine beta-amyloid in the hippocampus. PK(-/-)/Tau(VLW) mice have organomegaly of the liver, spleen and kidneys. The electron microscopy of the liver confirmed the presence of a fibrillary protein deposits with amyloid characteristics. There is also accumulation of mouse tau in hepatocytes. These mice have lower levels of CHIP-HSP70, involved in the proteosomal degradation of tau, increased oxidative stress, measured as depletion of glutathione which, added to lack of parkin, could trigger tau accumulation and amyloidogenesis. This model is the first that demonstrates beta-amyloid deposits caused by over-expression of tau and without modification of the amyloid precursor protein, presenilins or secretases. PK(-/-)/Tau(VLW) mice provide a link between the two proteins more important for the pathogenesis of Alzheimer disease.

    Human molecular genetics 2008;17;20;3128-43

  • Low plasma progranulin levels predict progranulin mutations in frontotemporal lobar degeneration.

    Ghidoni R, Benussi L, Glionna M, Franzoni M and Binetti G

    NeuroBioGen Lab-Memory Clinic, IRCCS Centro San Giovanni di Dio-Fatebenefratelli, via Pilastroni 4, 25125 Brescia, Italy.

    Background: Mutations in the progranulin gene (PGRN) were identified as the causal mechanism underlying frontotemporal lobar degeneration (FTLD). Most of these mutations are predicted to create null alleles leading to a 50% loss of progranulin transcript.

    Methods: Patients underwent clinical and neurologic examination at the Memory Clinic of the IRCCS S. Giovanni di Dio-Fatebenefratelli, Brescia, Italy. We enrolled affected (n = 6) and unaffected at risk members (n = 73) of families carrying the FTLD associated progranulin Leu271LeufsX10 mutation; additionally, we included subjects affected by sporadic/familial FTLD (n = 65), controls (n = 75), and a family carrying the tau P301L mutation. The presence of mutations in PGRN and MAPT genes was investigated by direct sequencing of exonic and flanking intronic regions. Progranulin plasma and CSF levels were measured using ELISA.

    Results: We demonstrated that progranulin protein is strongly reduced (up to 3.93-fold) both in plasma and CSF of affected and unaffected subjects carrying mutations in progranulin gene (PGRN Leu271LeufsX10 and Q341X). We established a plasma progranulin protein cutoff level of 74.4 ng/mL that identifies, with specificity and sensitivity of 100%, mutation carriers among unaffected subjects. In FTLD, values <or=110.9 ng/mL give a specificity of 92.8% and a sensitivity of 100% for PGRN mutations.

    Conclusions: We propose the dosage of plasma progranulin as a useful tool for a quick and inexpensive large-scale screening of carriers of progranulin mutations and for monitoring future treatments that might boost the level of this protein.

    Neurology 2008;71;16;1235-9

  • Structural characterization of binding of Cu(II) to tau protein.

    Soragni A, Zambelli B, Mukrasch MD, Biernat J, Jeganathan S, Griesinger C, Ciurli S, Mandelkow E and Zweckstetter M

    Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Gottingen, Germany.

    Transition metals have been frequently recognized as risk factors in neurodegenerative disorders, and brain lesions associated with Alzheimer's disease are rich in Fe(III), Zn(II), and Cu(II). By using different biophysical techniques (nuclear magnetic resonance, circular dichroism, light scattering, and microcalorimetry), we have structurally characterized the binding of Cu(II) to a 198 amino acid fragment of the protein Tau that can mimic both the aggregation behavior and microtubule binding properties of the full-length protein. We demonstrate that Tau can specifically bind one Cu(II) ion per monomer with a dissociation constant in the micromolar range, an affinity comparable to the binding of Cu(II) to other proteins involved in neurodegenerative diseases. NMR spectroscopy showed that two short stretches of residues, (287)VQSKCGS (293) and (310)YKPVDLSKVTSKCGS (324), are primarily involved in copper binding, in agreement with mutational analysis. According to circular dichroism and NMR spectroscopy, Tau remains largely disordered upon binding to Cu(II), although a limited amount of aggregation is induced.

    Biochemistry 2008;47;41;10841-51

  • O-GlcNAcylation modulates the self-aggregation ability of the fourth microtubule-binding repeat of tau.

    Yu CH, Si T, Wu WH, Hu J, Du JT, Zhao YF and Li YM

    Department of Chemistry, Beihua University, Jilin 132013, PR China.

    In Alzheimer's disease (AD), tau protein is abnormally hyperphosphorylated and aggregated into paired helical filaments (PHFs). It was discovered recently that tau is also O-GlcNAcylated in human brains. And O-GlcNAcylation may regulate phosphorylation of tau in a site-specific manner. In this work, we focused on the fourth microtubule-binding repeat (R4) of tau, which has an O-GlcNAcylation site-Ser356. The aggregation behavior of this repeat and its O-GlcNAcylated form was investigated by turbidity, precipitation assay and electron microscopy. In addition, conformations of these two peptides were analyzed with circular dichroism (CD). Our results revealed that O-GlcNAcylation at Ser356 could greatly slow down the aggregation speed of R4 peptide. This modulation of O-GlcNAcylation on tau aggregation implies a new perspective of tau pathology.

    Biochemical and biophysical research communications 2008;375;1;59-62

  • Glycogen synthase kinase-3beta and tau genes interact in Alzheimer's disease.

    Kwok JB, Loy CT, Hamilton G, Lau E, Hallupp M, Williams J, Owen MJ, Broe GA, Tang N, Lam L, Powell JF, Lovestone S and Schofield PR

    Prince of Wales Medical Research Institute, Randwick, Sydney, Australia. j.kwok@powmri.edu.au

    Objective: We examined the epistatic effect between haplotypes of glycogen synthase kinase-3beta (GSK3B) gene and microtubule-associated protein Tau (MAPT) gene in Alzheimer's disease (AD).

    Methods: A genetic association study of three AD cohorts was made. Linear regression analyses were used to examine effects of MAPT polymorphisms on gene expression and alternative splicing. beta-Catenin levels and signaling were determined using Western blot and luciferase reporter assays in cells transfected with a combination of GSK3B and MAPT complementary DNA.

    Results: Consistent interaction between GSK3B and MAPT genes in three late-onset AD cohorts was observed, with the GSK3B haplotype (T-T) significantly increasing the risk for AD in individuals with at least one H2 haplotype (odds ratio, 1.68-2.33; p = 0.005-0.036). The GSK3B haplotype was significantly protective in the Chinese cohort (odds ratio, 0.33; p = 0.016), after adjusting for the effect of age and sex. There are significant differences in in vivo transcriptional efficiency between the two MAPT haplotypes (H1 and H2) as determined by measurement of cerebellar transcripts (p < 0.001). Overexpression of either MAPT or GSK3B resulted in decreased beta-catenin levels compared with a control vector (p < 0.001). Conversely, cotransfection of both of these molecules increased beta-catenin signaling.

    Interpretation: Our genetic and biochemical analyses have identified a novel interaction between Tau and GSK-3beta in late-onset AD causative factors. Our data are consistent with an epistatic model of interaction where discordant levels of GSK3B and MAPT gene expression can lead to altered beta-catenin levels and pathogenicity.

    Funded by: Medical Research Council: G0300429, G9810900

    Annals of neurology 2008;64;4;446-54

  • Increasing CSF phospho-tau levels during cognitive decline and progression to dementia.

    Andersson C, Blennow K, Almkvist O, Andreasen N, Engfeldt P, Johansson SE, Lindau M and Eriksdotter-Jönhagen M

    Department of Neurobiology, Caring Sciences and Society, Karolinska Institutet, NOVUM Karolinska University Hospital Huddinge, S-141 86 Stockholm, Sweden. christin.andersson@ki.se

    Background: Little is known about longitudinal changes of cerebrospinal fluid (CSF) biomarkers during cognitive decline in neurodegenerative disease progression.

    Objective: To investigate longitudinal changes in CSF biomarkers--total-tau (T-tau), phospho-tau (P-tau) and beta-amyloid (Abeta42)--during cognitive decline.

    Methods: Forty memory clinic patients (47.5% females), aged 61.3+/-7.6 (S.D.) years, non-demented at baseline, underwent lumbar puncture and neuropsychological testing at two occasions. Baseline mean MMSE-score was 28.3+/-1.8. Patients were divided into three groups based on baseline memory functioning; severely impaired (SIM), moderately impaired (MIM) and no impairment (NIM).

    Results: There was a significant increase in P-tau in the SIM-group during follow-up, while P-tau in MIM and NIM did not change. Eighty-three percent of the SIM-patients converted to dementia (80% AD), while most MIM- and NIM-patients remained non-demented. T-tau- and Abeta42-levels did not change in any of the memory groups during follow-up.

    Conclusion: Increasing P-tau levels during cognitive decline and conversion to dementia suggest that P-tau may be useful as a longitudinal marker of the neurodegenerative process.

    Neurobiology of aging 2008;29;10;1466-73

  • Phosphorylated tau in neuritic plaques of APP(sw)/Tau (vlw) transgenic mice and Alzheimer disease.

    Pérez M, Morán MA, Ferrer I, Avila J and Gómez-Ramos P

    Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo s/n, 28029 Madrid, Spain.

    We have previously reported that double-transgenic APP(SW)/Tau(VLW) mice show enhanced amyloid deposition, stronger tau hyperphosphorylation, increased sarkosyl tau polymers, and wider tau filaments when compared to simple mutant models. To validate these transgenic mice as models of Alzheimer disease pathology, in the present study we analyze tau phosphorylation at 12E8 and AT-8 epitopes in amyloid plaques. In APP(SW) mice, phospho-tau in plaque-associated neurites suggests a local direct effect of plaque-amyloid (and/or APP(SW)) on tau phosphorylation. In vitro, attempts to identify which kinases are induced by fibrillar amyloid reveal to Protein Kinase C as responsible for phosphorylation at the 12E8 epitope. Tau(VLW) mice, without plaques, show increased tau phosphorylation at the 12E8 epitope, particularly in pyramidal neurons. APP(SW)/Tau(VLW) mice show earlier and stronger 12E8 tau phosphorylation. Ultrastructurally, the same two types of neurites are found in plaques from APP(SW)/Tau(VLW) and Alzheimer disease (AD) brains: (a) dystrophic giant neurites filled with degenerating organelles and/or phospho-tau-positive filaments and (b) non-dystrophic phospho-tau-positive small punctiform neurites. Both types of plaque-associated neurites are AT-8 positive in APP(SW)/Tau(VLW) mice and AD, but 12E8-positive dystrophic neurites are only detected in AD. We conclude that the simultaneous presence of human mutated Tau(VLW) and plaque-amyloid (and/or APP(SW)) potentiates and anticipates tau phosphorylation at the 12E8 epitope, intensifying pyramidal neuron immunostaining and tau filament formation in this double-transgenic model. Thus, the APP(SW)/Tau(VLW) mouse is a useful model to study neuritic plaques, since they reproduce most of the characteristics that these structures have in AD.

    Acta neuropathologica 2008;116;4;409-18

  • Tau and S100B proteins as biochemical markers of bilirubin-induced neurotoxicity in term neonates.

    Okumus N, Turkyilmaz C, Onal EE, Atalay Y, Serdaroglu A, Elbeg S, Koc E, Deda G, Cansu A and Gunduz B

    Division of Neonatology, Faculty of Medicine, Gazi University, Ankara, Turkey. drnuri@hotmail.com

    We investigated the relationship between total serum bilirubin and serum Tau and S100B protein levels, and predicted a cutoff level of bilirubin-induced neurotoxicity in term newborns. Total serum bilirubin, serum Tau, and S100B levels were measured in 92 jaundiced term newborns. A neurologic examination, electroencephalogram, brainstem auditory-evoked response, and otoacoustic emission were performed in the infants on admission and at age 3 months. Serum Tau (r = 0.921, P < 0.001) and S100B (r = 0.927, P < 0.001) levels were correlated with total serum bilirubin levels in all infants. Serum Tau and S100B protein levels remained at a steady level up to a total serum bilirubin level of 19.1 mg/dL, and then demonstrated a significant increase. Mean total serum bilirubin, serum Tau, and S100B levels of infants who manifested auditory neuropathy, neurologic abnormalities, or electroencephalogram abnormalities were significantly higher than in infants without these abnormalities (P < 0.05). Clinical and laboratory findings of bilirubin-induced neurotoxicity developed after a total serum bilirubin level of 22 mg/dL was reached. Serum levels of Tau and S100B proteins in jaundiced term newborns were strongly correlated with early-phase bilirubin encephalopathy.

    Pediatric neurology 2008;39;4;245-52

  • Do mood symptoms subdivide the schizophrenia phenotype? Association of the GMP6A gene with a depression subgroup.

    Boks MP, Hoogendoorn M, Jungerius BJ, Bakker SC, Sommer IE, Sinke RJ, Ophoff RA and Kahn RS

    Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, The Netherlands. mboks@umcutrecht.nl

    Genetic studies of clinically defined subgroups of schizophrenia patients may reduce the phenotypic heterogeneity of schizophrenia and thus facilitate the identification of genes that confer risk to this disorder. Several latent class analyses have provided subgroups of psychotic disorders that show considerable consistency over these studies. The presence or absence of mood symptoms was found to contribute most to the delineations of these subgroups. In this study we used six previously published subtypes of psychosis derived from latent class analysis of a large sample of psychosis patients. In 280 schizophrenia patients and 525 healthy controls we investigated the associations of these subgroups with myelin related genes. After bonferroni correction we found an association of the glycoprotein M6A gene (GPM6A) with the subgroup of schizophrenia patients with high levels of depression (P-corrected = 0.006). Borderline association of the microtubulin associated protein tau (MAPT) with a primarily non-affective group of schizophrenia patients (P-corrected = 0.052) was also observed. GPM6A modulates the influence of stress on the hippocampus in animals. Thus our findings could suggest that GMP6A plays a role in the stress-induced hippocampal alterations that are found in psychiatric disorders in general and schizophrenia in particular. Overall, these finding suggests that investigating subgroups of schizophrenia based symptoms profile and particularly mood symptoms can facilitate genetic studies of schizophrenia.

    American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 2008;147B;6;707-11

  • Estradiol attenuates tau hyperphosphorylation induced by upregulation of protein kinase-A.

    Liu XA, Zhu LQ, Zhang Q, Shi HR, Wang SH, Wang Q and Wang JZ

    Pathophysiology Department, Tongji Medical College, Hua-Zhong University of Science and Technology, Wuhan, 430030, PR China.

    Protein kinase A (PKA) plays a crucial role in tau hyperphosphorylation, an early event of Alzheimer disease (AD), and 17beta-estradiol replacement in aging women forestalls the onset of AD. However, the role of estradiol in PKA-induced tau hyperphosphorylation is not known. Here, we investigated the effect of 17beta-estradiol on cAMP/PKA activity and the PKA-induced tau hyperphosphorylation in HEK293 cells stably expressing tau441. We found that 17beta-estradiol effectively attenuated forskolin-induced overactivation of PKA and elevation of cAMP, and thus prevented tau from hyperphosphorylation. These data provide the first evidence that 17beta-estradiol can inhibit PKA overactivation and the PKA-induced tau hyperphosphorylation, implying a preventive role of 17beta-estradiol in AD-like tau pathology.

    Neurochemical research 2008;33;9;1811-20

  • Evolutionary toggling of the MAPT 17q21.31 inversion region.

    Zody MC, Jiang Z, Fung HC, Antonacci F, Hillier LW, Cardone MF, Graves TA, Kidd JM, Cheng Z, Abouelleil A, Chen L, Wallis J, Glasscock J, Wilson RK, Reily AD, Duckworth J, Ventura M, Hardy J, Warren WC and Eichler EE

    Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA.

    Using comparative sequencing approaches, we investigated the evolutionary history of the European-enriched 17q21.31 MAPT inversion polymorphism. We present a detailed, BAC-based sequence assembly of the inverted human H2 haplotype and compare it to the sequence structure and genetic variation of the corresponding 1.5-Mb region for the noninverted H1 human haplotype and that of chimpanzee and orangutan. We found that inversion of the MAPT region is similarly polymorphic in other great ape species, and we present evidence that the inversions occurred independently in chimpanzees and humans. In humans, the inversion breakpoints correspond to core duplications with the LRRC37 gene family. Our analysis favors the H2 configuration and sequence haplotype as the likely great ape and human ancestral state, with inversion recurrences during primate evolution. We show that the H2 architecture has evolved more extensive sequence homology, perhaps explaining its tendency to undergo microdeletion associated with mental retardation in European populations.

    Funded by: Howard Hughes Medical Institute; Intramural NIH HHS: Z01 AG000957-05; Medical Research Council: G0701075; NHGRI NIH HHS: HG002385, R01 HG002385, R01 HG002385-08; NIA NIH HHS: Z01 AG000957, Z01 AG000957-05; NIGMS NIH HHS: GM058815, R01 GM058815, R01 GM058815-08

    Nature genetics 2008;40;9;1076-83

  • Histone deacetylase 6 interacts with the microtubule-associated protein tau.

    Ding H, Dolan PJ and Johnson GV

    Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA.

    Histone deacetylase 6 (HDAC6), a unique cytoplasmic deacetylase, likely plays a role in neurodegeneration by coordinating cell responses to abnormal protein aggregation. Here, we provide in vitro and in vivo evidence that HDAC6 interacts with tau, a microtubule-associated protein that forms neurofibrillary tangles in Alzheimer's disease. This interaction is mediated by the microtubule-binding domain on tau and the Ser/Glu tetradecapeptide domain on HDAC6. Treatment with tubacin, a selective inhibitor of tubulin deacetylation activity of HDAC6, did not disrupt HDAC6-tau interaction. Nonetheless tubacin treatment attenuated site-specific tau phosphorylation, as did shRNA-mediated knockdown of HDAC6. Proteasome inhibition potentiated HDAC6-tau interactions and facilitated the concentration and co-localization of HDAC6 and tau in a perinuclear aggresome-like compartment, independent of HDAC6 tubulin deacetylase activity. Furthermore, we observed that in Alzheimer's disease brains the protein level of HDAC6 was significantly increased. These findings establish HDAC6 as a tau-interacting protein and as a potential modulator of tau phosphorylation and accumulation.

    Funded by: NIA NIH HHS: P50 AG16582; NINDS NIH HHS: NS051279, R01 NS051279-04

    Journal of neurochemistry 2008;106;5;2119-30

  • Neurofibrillary tau pathology modulated by genetic variation of alpha-synuclein.

    Peuralinna T, Oinas M, Polvikoski T, Paetau A, Sulkava R, Niinistö L, Kalimo H, Hernandez D, Hardy J, Singleton A, Tienari PJ and Myllykangas L

    Molecular Neurology Programme, Biomedicum, University of Helsinki, Helsinki, Finland.

    We analyzed whether genetic variation of alpha-synuclein modulates the extent of neuropathological changes in a population-based autopsied sample of 272 elderly Finns. None of the 11 markers was associated with the extent of neocortical beta-amyloid pathology. The intron 4 marker rs2572324 was associated with the extent of neurofibrillary pathology (p = 0.0006, permuted p = 0.004; Braak stages IV-VI vs 0-II). The same variant also showed a trend for association with neocortical Lewy-related pathology. These results suggest for the first time that variation of alpha-synuclein modulates neurofibrillary tau pathology and support the recent observations of an interaction of alpha-synuclein and tau in neurodegeneration.

    Funded by: Medical Research Council: G0701075; Parkinson's UK: G-0907

    Annals of neurology 2008;64;3;348-52

  • Pre-assembled tau filaments phosphorylated by GSK-3b form large tangle-like structures.

    Rankin CA, Sun Q and Gamblin TC

    Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA.

    Hyperphosphorylated tau protein is a major component of neurofibrillary tangles, a prominent intracellular hallmark of Alzheimer's disease. Both hyperphosphorylated tau and neurofibrillary tangles have been shown to correlate with dementia in Alzheimer's disease, but the relationship between hyperphosphorylation and tangle formation is not clear. Using a cell-free in vitro model system, in which tau polymerization is induced by arachidonic acid, we show that GSK-3beta phosphorylation of pre-assembled tau filaments makes those filaments prone to coalesce into large neurofibrillary tangle-like structures. Five phosphorylation sites, S199, T205, T231, S396 and S404, were identified in the phosphorylated filaments; many of the five are within epitopes recognized by Alzheimer's disease-associated antibodies. These tangle-like structures are optically visible and are similar to those formed by polymerization of GSK-3beta phosphorylated tau monomer and to those isolated from Alzheimer's disease tissue. We conclude that the phosphorylation of tau by GSK-3beta either prior to or following polymerization promotes polymer/polymer interactions that result in stable clusters of tau filaments.

    Funded by: NIA NIH HHS: AG022428, AG025898, K02 AG025898, K02 AG025898-03, R01 AG022428, R01 AG022428-05

    Neurobiology of disease 2008;31;3;368-77

  • Tau hyperphosphorylation correlates with reduced methylation of protein phosphatase 2A.

    Zhou XW, Gustafsson JA, Tanila H, Bjorkdahl C, Liu R, Winblad B and Pei JJ

    Karolinska Institutet, KI-Alzheimer Disease Research Center (KI-ADRC), Novum, Huddinge, Sweden.

    The down-regulation of protein phosphatase 2A (PP2A) activity is thought to play an important role in the formation of tau hyperphosphorylation in the Alzheimer's disease (AD) brain. Methylation of the PP2A catalytic subunit at the L309 site can potently activate PP2A for some substrates via the increasing recruitment of its regulatory subunits into the holoenzyme. Abeta is overproduced yet estrogen is deficient in the brains of the menopausal AD patients. Both Abeta and estrogen deficiency can interact with tau kinases such as protein kinase B and glycogen synthase kinase 3. In the current study, levels of demethylated (-m) PP2A (L309) were significantly increased, and methylated (+m) PP2A (L309) were significantly decreased, which corresponded with the increased tau phosphorylation at the Tau-1 and PHF-1 sites in both mouse N2a cells carrying the human APP with Swedish mutation (APPswe) and transgenic APPswe/presenilin (PS) 1 (A246E) mice. These findings were replicated in wild-type N2a cells treated with Abeta25-35, and to a relatively larger extent, in both wild-type N2a cells and APPswe treated by okadaic acid, as well as in the brains of estrogen receptor (ER) alpha-/- and ERbeta-/- mice that mimic the status of estrogen deficiency in menopausal AD patients. Together, these findings suggested that the increased demethylation of PP2A (L309) mediated by Abeta overproduction or estrogen deficiency (ERalpha-/- and ERbeta-/-) may contribute to the reduced PP2A activity observed in the AD brain, resulting in the compromised dephosphorylation of abnormally hyperphosphorylated tau.

    Neurobiology of disease 2008;31;3;386-94

  • Two motifs within the tau microtubule-binding domain mediate its association with the hsc70 molecular chaperone.

    Sarkar M, Kuret J and Lee G

    Program in Neuroscience and Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa 52242, USA.

    Tau, a microtubule-associated protein with multiple phosphorylation sites, forms aggregates that correlate with neurodegeneration in Alzheimer's disease and several other neurodegenerative diseases, termed tauopathies. Hsc70 is a highly expressed constitutive chaperone that can drive conformational change in proteins, prevent the aggregation of its substrates, recognize misfolded substrates, and facilitate their degradation. Here, we show that hsc70 binds to the microtubule-binding domain of tau in vitro and in vivo, without an absolute requirement for tau phosphorylation. Binding requires a carboxy-terminal region of hsc70 comprising its peptide-binding and variable domains. We have identified two hsc70 binding sites on tau and hydrophobic amino acids crucial for hsc70 binding. Interestingly, these hsc70 binding sites correspond to the beta-structure elements that have been previously reported to facilitate tau aggregation. Thus, it is possible that hsc70 binding might directly inhibit tau-tau interactions that precede tau oligomerization and aggregation. Our results provide an important stimulus for research into how the hsc70-tau interaction might affect tau fate in normal cells and in disease.

    Funded by: NIA NIH HHS: AG14452, R01 AG014452; NINDS NIH HHS: NS32100, R01 NS032100

    Journal of neuroscience research 2008;86;12;2763-73

  • A possible link between astrocyte activation and tau nitration in Alzheimer's disease.

    Reyes JF, Reynolds MR, Horowitz PM, Fu Y, Guillozet-Bongaarts AL, Berry R and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. juan-reyes@northwestern.edu

    Alzheimer's disease (AD) pathology has been characterized, in part, by the self-assembly of the tau molecule into neurofibrillary tangles (NFT). While different post-translational modifications have been identified that accelerate tau aggregation, nitration at tyrosine residues prevents or slows tau filament formation in vitro. Of the five tyrosine residues within the molecule, nitration at the first tyrosine residue (Tyr 18) results in a profound inhibition of filament self-assembly. To determine whether nitration at Tyr 18 occurs in AD pathology, monoclonal antibodies were raised against a synthetic tau peptide nitrated at Tyr 18. A clone, termed Tau-nY18, reacts specifically with tau proteins nitrated at Tyr 18 and fails to cross-react with other nitrated tyrosine residues spanning the length of the molecule or with other proteins known to be nitrated in neurodegenerative diseases. In situ, Tau-nY18 sparsely labels the neuronal pathological hallmarks of the disease, including NFT and dystrophic neurites. Surprisingly however, Tau-nY18 robustly labels nitrated tau within activated, GFAP positive astrocytes intimately associated with amyloid plaques. Furthermore, this antibody detects nitrated tau in soluble preparations from both severe AD brains (Braak stage V, VI) and age-matched controls. Collectively, these findings suggest that nitration at Tyr 18 may be linked to astrocyte activation, an early event associated with amyloid plaque formation.

    Funded by: NIA NIH HHS: AG021184, AG09466, P01 AG009466-14A1, P01 AG021184, P01 AG021184-01A10002; NIGMS NIH HHS: R25 GM068929, R25 GM068929-04, R25-GM068929

    Neurobiology of disease 2008;31;2;198-208

  • Genetic analysis of MAPT haplotype diversity in frontotemporal dementia.

    Laws SM, Friedrich P, Diehl-Schmid J, Müller J, Ibach B, Bäuml J, Eisele T, Förstl H, Kurz A and Riemenschneider M

    Neurochemistry and Neurogenetics Laboratory, Department of Psychiatry and Psychotherapy, Technische Universität München (TU-München), Ismaningerstr. 22, D-81675 München, Germany.

    The H1 haplotype of the tau gene, MAPT, has been linked to the sporadic tauopathies corticobasal degeneration and progressive supranuclear palsy; however, there have been inconsistent findings regarding association with frontotemporal dementia (FTD). We investigated MAPT haplotype diversity, in 171 sporadic FTD and 186 healthy controls individuals, and report no single marker or haplotype association with increased risk or changes in age at onset. These findings do not support an association of MAPT with FTD but do not rule out its association with other tauopathies.

    Neurobiology of aging 2008;29;8;1276-8

  • Turning down tau phosphorylation.

    Fischer PM

    School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham NG7 2RD, UK. peter.fischer@nottingham.ac.uk

    Phosphorylation and glycosylation of the tau protein, which is implicated in neurodegenerative diseases, are intimately linked. In vivo pharmacological inhibition of tau deglycosylation may be a new way to suppress abnormal tau phosphorylation, known to be involved in the formation of neurofibrillary tangles in the brain.

    Nature chemical biology 2008;4;8;448-9

  • A soluble oligomer of tau associated with fiber formation analyzed by NMR.

    Peterson DW, Zhou H, Dahlquist FW and Lew J

    Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA.

    Alzheimer's disease (AD) is characterized by the intracellular accumulation of the neurofibrillary tangles comprised mainly of the microtubule-associated protein, tau. A critical aspect of understanding tangle formation is to understand the transition of soluble monomeric tau into mature fibrils by characterizing the structure of intermediates along the aggregation pathway. We have carried out multidimensional NMR studies on a C-terminal fragment of human tau (tau (187)) to gain structural insight into the aggregation process. To specifically monitor intermolecular interaction between tau molecules in solution, we combined (15)N- and (14)N-labeled tau, the latter of which was modified with a paramagnetic nitroxide spin label (MTSL). Paramagnetic relaxation enhancement (PRE) of (15)N-tau by interaction with MTSL- (14)N-tau allowed identification of low molecular weight oligomers of tau (187) that formed in response to heparin-induced aggregation. Two regions, VQIINK (280) and VQIVYK (311), were exclusively broadened by MTSL located at varied positions in the tau molecule. We propose that soluble oligomers of tau (187) are generated via intermolecular interactions at these motifs triggered by heparin addition. However, the associated line broadening at these motifs cannot be due to interaction between tau (187) and heparin directly. Instead, these specific interactions necessarily occur between tau molecules and are intermolecular in nature. Our data support the idea that VQIINK (280) and VQIVYK (311) are the major, if not sole, critical regions that directly mediate intermolecular contact between tau molecules during the early phases of aggregation.

    Funded by: NCRR NIH HHS: S10 RR020900

    Biochemistry 2008;47;28;7393-404

  • Binding to the minor groove of the double-strand, tau protein prevents DNA from damage by peroxidation.

    Wei Y, Qu MH, Wang XS, Chen L, Wang DL, Liu Y, Hua Q and He RQ

    State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.

    Tau, an important microtubule associated protein, has been found to bind to DNA, and to be localized in the nuclei of both neurons and some non-neuronal cells. Here, using electrophoretic mobility shifting assay (EMSA) in the presence of DNA with different chain-lengths, we observed that tau protein favored binding to a 13 bp or a longer polynucleotide. The results from atomic force microscopy also showed that tau protein preferred a 13 bp polynucleotide to a 12 bp or shorter polynucleotide. In a competitive assay, a minor groove binder distamycin A was able to replace the bound tau from the DNA double helix, indicating that tau protein binds to the minor groove. Tau protein was able to protect the double-strand from digestion in the presence of DNase I that was bound to the minor groove. On the other hand, a major groove binder methyl green as a negative competitor exhibited little effect on the retardation of tau-DNA complex in EMSA. This further indicates the DNA minor groove as the binding site for tau protein. EMSA with truncated tau proteins showed that both the proline-rich domain (PRD) and the microtubule-binding domain (MTBD) contributed to the interaction with DNA; that is to say, both PRD and MTBD bound to the minor groove of DNA and bent the double-strand, as observed by electron microscopy. To investigate whether tau protein is able to prevent DNA from the impairment by hydroxyl free radical, the chemiluminescence emitted by the phen-Cu/H(2)O(2)/ascorbate was measured. The emission intensity of the luminescence was markedly decreased when tau protein was present, suggesting a significant protection of DNA from the damage in the presence of hydroxyl free radical.

    PloS one 2008;3;7;e2600

  • Haplotypes and gene expression implicate the MAPT region for Parkinson disease: the GenePD Study.

    Tobin JE, Latourelle JC, Lew MF, Klein C, Suchowersky O, Shill HA, Golbe LI, Mark MH, Growdon JH, Wooten GF, Racette BA, Perlmutter JS, Watts R, Guttman M, Baker KB, Goldwurm S, Pezzoli G, Singer C, Saint-Hilaire MH, Hendricks AE, Williamson S, Nagle MW, Wilk JB, Massood T, Laramie JM, DeStefano AL, Litvan I, Nicholson G, Corbett A, Isaacson S, Burn DJ, Chinnery PF, Pramstaller PP, Sherman S, Al-hinti J, Drasby E, Nance M, Moller AT, Ostergaard K, Roxburgh R, Snow B, Slevin JT, Cambi F, Gusella JF and Myers RH

    Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA. jetobinphd@gmail.com

    Background: Microtubule-associated protein tau (MAPT) has been associated with several neurodegenerative disorders including forms of parkinsonism and Parkinson disease (PD). We evaluated the association of the MAPT region with PD in a large cohort of familial PD cases recruited by the GenePD Study. In addition, postmortem brain samples from patients with PD and neurologically normal controls were used to evaluate whether the expression of the 3-repeat and 4-repeat isoforms of MAPT, and neighboring genes Saitohin (STH) and KIAA1267, are altered in PD cerebellum.

    Methods: Twenty-one single-nucleotide polymorphisms (SNPs) in the region of MAPT on chromosome 17q21 were genotyped in the GenePD Study. Single SNPs and haplotypes, including the H1 haplotype, were evaluated for association to PD. Relative quantification of gene expression was performed using real-time RT-PCR.

    Results: After adjusting for multiple comparisons, SNP rs1800547 was significantly associated with PD affection. While the H1 haplotype was associated with a significantly increased risk for PD, a novel H1 subhaplotype was identified that predicted a greater increased risk for PD. The expression of 4-repeat MAPT, STH, and KIAA1267 was significantly increased in PD brains relative to controls. No difference in expression was observed for 3-repeat MAPT.

    Conclusions: This study supports a role for MAPT in the pathogenesis of familial and idiopathic Parkinson disease (PD). Interestingly, the results of the gene expression studies suggest that other genes in the vicinity of MAPT, specifically STH and KIAA1267, may also have a role in PD and suggest complex effects for the genes in this region on PD risk.

    Funded by: NHLBI NIH HHS: N01-HC 25195; NIA NIH HHS: 5-T32-AG00277-05, 5R01-AG 16495, 5R01-AG08122, P30 AG13846; NIGMS NIH HHS: T32 GM074905; NIMH NIH HHS: R24 MH 068855; NINDS NIH HHS: 2R01-NS17950, R01 NS036711-09, R01 NS041509, R01 NS041509-08A2, R01 NS041509-09, R01 NS050425-05, R01 NS058714-02, R01 NS058714-03, R01 NS36711-05; Telethon: GTF04007

    Neurology 2008;71;1;28-34

  • A novel transgenic mouse expressing double mutant tau driven by its natural promoter exhibits tauopathy characteristics.

    Rosenmann H, Grigoriadis N, Eldar-Levy H, Avital A, Rozenstein L, Touloumi O, Behar L, Ben-Hur T, Avraham Y, Berry E, Segal M, Ginzburg I and Abramsky O

    The Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah University Medical Center, Jerusalem, Israel. rosenman@hadassah.org.il

    The neurofibrillary-tangles (NTFs), characteristic of tauopathies including Alzheimer's-disease (AD), are the pathological features which correlate best with dementia. The objective of our study was to generate an authentic transgenic (tg) animal model for NFT pathology in tauopathy/AD. Previous NFT-tg mice were driven by non-related/non-homologous promoters. Our strategy was to use the natural tau promoter for expressing the human-tau (htau) gene with two mutations K257T/P301S (double mutant, DM) associated with severe phenotypes of frontotemporal-dementia in humans. Cellular, biochemical, behavioral and electrophysiological studies were subsequently conducted. The tg mice showed a tolerated physiological level of the DM-htau protein, mostly in cortex and hippocampus. The mice demonstrated tauopathy-like characteristics, which increased with age, that included NFT-related pathology, astrogliosis, argyrophilic plaque-like (amyloid-free) structures in brain, with memory deficits and signs of anxiety. Moreover, the tg mice showed a robust synaptic plasticity deficit selectively expressed in a severe impairment in their ability to maintain hippocampal long-term-potentiation (LTP) in response to stimulation of the perforant path, providing evidence that "tau-pathology only" is sufficient to cause this memory and learning-associated deficit. This is a unique mutant-htau-tg model which presents a wide spectrum of features characteristic of tauopathy/AD, which does not show unrelated motor deficits described in other models of tauopathy. In addition, expressing the DM-htau in a neuronal cell model resulted in tau-aggregation, as well as impaired microtubule arrangement. Both animal and cell models, which were regulated under the natural tau promoter (of rat origin), provide authentic and reliable models for tauopathy, and offer valuable tools for understanding the molecular events underlying tauopathies including AD.

    Experimental neurology 2008;212;1;71-84

  • Divergent phosphorylation pattern of tau in P301L tau transgenic mice.

    Deters N, Ittner LM and Götz J

    Alzheimer's and Parkinson's Disease Laboratory, Brain & Mind Research Institute, University of Sydney, 100 Mallett St, Camperdown, NSW 2050, Australia.

    Aggregates of hyperphosphorylated tau are prominent in brains of patients with Alzheimer's disease or frontotemporal dementia (FTD). They have been reproduced in animal models following the identification of tau mutations in familial cases of FTD. This includes our previously generated transgenic model, pR5, which expresses FTD (P301L) mutant tau in neurons. The mice are characterized by tau aggregation including tangle (NFT) formation, memory impairment and mitochondrial dysfunction. In 8-month-old mice, S422 phosphorylation of tau is linked to NFT formation, however, a detailed analysis of tau solubility, phosphorylation and aggregation has not been done nor have the mice been monitored until a high age. Here, we undertook an analysis by immunohistochemistry, Gallyas impregnation and Western blotting of brains from 3 month- up to 20 month-old mice. NFTs first appeared at 6 months in the amygdala, followed by the CA1 region of the hippocampus. As the mice get older, the solubility of tau is decreased as determined by sequential extractions. Histological analysis revealed increased phosphorylation at the AT180, AT270 and 12E8 epitopes with ageing. The numbers of AT8-positive neurons increased from 3 to 6 months old. However, whereas S422 appeared only late and concomitantly with NFT formation, the only neurons left with AT8-reactivity at 20 months were those that had undergone NFT formation. As hyperphosphorylated tau continued to accumulate, the lack of AT8-reactivity suggests regulatory mechanisms in specifically dephosphorylating the AT8 epitope in the remaining neurons. Thus, differential regulation of phosphorylation is important for NFT formation in neurodegenerative diseases with tau pathology.

    The European journal of neuroscience 2008;28;1;137-47

  • Identification of a caspase-derived N-terminal tau fragment in cellular and animal Alzheimer's disease models.

    Corsetti V, Amadoro G, Gentile A, Capsoni S, Ciotti MT, Cencioni MT, Atlante A, Canu N, Rohn TT, Cattaneo A and Calissano P

    European Brain Research Institute (EBRI), Via del Fosso di Fiorano 64-65, 00143 Rome, Italy.

    Biochemical modifications of tau proteins have been proposed to be among the earliest neurobiological changes in Alzheimer's disease (AD) and correlate better with cognitive symptoms than do beta-amyloid plaques. We have recently reported that adenovirus-mediated overexpression of the NH2 26-230aa tau fragment evokes a potent NMDA-mediated neurotoxic effect in primary neuronal cultures. In order to assess whether such N-terminal tau fragment(s) are indeed produced during apoptosis or neurodegeneration in vivo, we attempted to ascertain their presence in cell and animal models using an anti-tau antibody directed against the N-terminal sequence of human protein located downstream of the caspase(s)-cleavage site DRKD(25)-QGGYTMHQDQ. We provide biochemical evidence that a caspase(s)-cleaved NH2-terminal tau fragment of 20-22 kDa, consistent with the size of the NH2 26-230aa neurotoxic fragment of tau, is generated in vitro in differentiated human SH-SY5Y cells undergoing apoptosis by BDNF withdrawal or following treatment with staurosporine. In addition this NH2-terminally cleaved tau fragment, whose expression correlates with a significant up-regulation of caspase(s) activity, is also specifically detected in vivo in the hippocampus of 15 month-old AD11 transgenic mice, a model in which a progressive AD-like neurodegeneration is induced by the expression of transgenic anti-NGF antibodies. The results support the idea that aberrant activation of caspase(s), following apoptotic stimuli or neurodegeneration insults, may produce one or more toxic NH2 tau fragments, that further contribute to propagate and increase cellular dysfunctions in AD.

    Funded by: NIA NIH HHS: R15 AG042781

    Molecular and cellular neurosciences 2008;38;3;381-92

  • Increased total-Tau levels in cerebrospinal fluid of pediatric hydrocephalus and brain tumor patients.

    de Bont JM, Vanderstichele H, Reddingius RE, Pieters R and van Gool SW

    Erasmus MC, University Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands. j.debont@erasmusmc.nl

    Total Tau (t-Tau), hyperphosphorylated Tau (p-Tau(181P)) and beta-amyloid(1-42) in cerebrospinal fluid (CSF) have shown to be markers of neuronal and axonal degeneration in various neurological and neurodegenerative diseases. The aim of this study was to evaluate the influence of the presence of a brain tumor and hydrocephalus on t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels in CSF of pediatric patients. t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels were simultaneously quantified by xMAP technology in 22 lumbar and 15 ventricular CSF samples from newly diagnosed pediatric brain tumor patients and 39 lumbar and 12 ventricular CSF samples from pediatric patients without a brain tumor. t-Tau, p-Tau(181P) and beta-amyloid(1-42) levels in both lumbar and ventricular CSF were not significantly correlated with age. t-Tau levels in lumbar CSF were elevated in brain tumor patients, being especially high in medulloblastoma patients. Lumbar CSF p-Tau(181P) levels were lower in brain tumor patients compared to normal controls. Ventricular levels of t-Tau, p-Tau(181P) and beta-amyloid(1-42) were not significantly different between the brain tumor patients and non-tumor patients, but t-Tau levels were significantly increased in patients with radiological signs of hydrocephalus. Two patients with an infected ventriculo-peritoneal drain also had high CSF t-Tau levels. In conclusion, high t-Tau levels in CSF are found in pediatric patients with a brain tumor, patients with hydrocephalus and patients with a serious CNS infection, reflecting neuronal and axonal damage. Ongoing studies should determine whether these neurodegenerative markers in CSF can be used to monitor neuronal and axonal degeneration in these patients during therapy and long-term follow up.

    European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society 2008;12;4;334-41

  • Inflammation induces tau pathology in inclusion body myositis model via glycogen synthase kinase-3beta.

    Kitazawa M, Trinh DN and LaFerla FM

    Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697-4545, USA.

    Objective: Inclusion body myositis (IBM) is an inflammatory muscle disease, although the role of inflammation remains to be elucidated. Here, we address the mechanisms by which inflammation modulates Abeta and tau, two hallmark features of this disease.

    Methods: A transgenic mouse model of IBM was utilized in which acute and chronic inflammation was induced via lipopolysaccharide. The effects of inflammation were assessed by analyzing the myopathological and the behavioral phenotype. Human IBM skeletal muscle biopsies were investigated to determine concordance with data from the animal model.

    Results: Both acute and chronic lipopolysaccharide exposure augmented infiltration by CD8(+) cytotoxic T cells and increased amyloid precursor protein steady-state levels in skeletal muscle, whereas increased Abeta generation was observed only in chronically treated mice. Both acute and chronic inflammation enhanced tau phosphorylation in skeletal muscle. The mechanism underlying this effect was mediated by the tau kinase, glycogen synthase kinase-3beta (GSK-3beta). Suppression of GSK-3beta activity using either a specific inhibitor or lithium chloride significantly reduced tau phosphorylation and partially rescued motor impairment. In human IBM muscle, GSK-3beta and phospho-tau were colocalized, further supporting the pathogenic role of GSK-3beta in this disease. Using C2C12 myoblast cultures, we found that GSK-3beta was activated by proinflammatory cytokines (interleukin-1beta, interleukin-6, tumor necrosis factor-alpha), leading to enhanced tau phosphorylation.

    Interpretation: Our results identify a molecular mechanism by which proinflammatory stimuli affect tau pathology via the GSK-3beta signaling pathway in skeletal muscle.

    Funded by: NIA NIH HHS: AG20335; NIAMS NIH HHS: AR054695

    Annals of neurology 2008;64;1;15-24

  • Truncated tau expression levels determine life span of a rat model of tauopathy without causing neuronal loss or correlating with terminal neurofibrillary tangle load.

    Koson P, Zilka N, Kovac A, Kovacech B, Korenova M, Filipcik P and Novak M

    Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Dubravska cesta 9, 845 10 Bratislava, Slovak Republic.

    We have previously demonstrated in a transgenic rat model of tauopathy that human misfolded truncated tau derived from Alzheimer's disease suffices to drive neurofibrillary degeneration in vivo. We employed this model to investigate the impact of truncated tau expression levels on life span, neuronal loss and the final load of neurofibrillary tangles (NFTs) in transgenic rats. Two independent transgenic lines (SHR72, SHR318), that display different expression levels of truncated tau, were utilized in this study. We found that transgene expression levels in the brain of SHR72 rats were 44% higher than in SHR318 rats and that truncated tau protein levels determined the survival rate of transgenic rats. The line with higher expression levels of truncated tau (SHR72) showed decreased median survival (222.5 days) when compared with the line with lower expression (SHR318; 294.5 days). Interestingly, NFT loads (total NFT/total neurons) were very similar in terminal stages of disease in both transgenic lines (SHR72 - 10.9%; SHR318 - 11.6%), despite significantly different expression levels of truncated tau. Moreover, mean neuron numbers in the hippocampus (CA1-3) and brain stem (gigantocellular reticular nucleus) in the two transgenic rat strains in the terminal stages of disease were similar, and did not differ significantly from those observed in age-matched non-transgenic controls. These findings suggest that the expression levels of misfolded truncated tau determine the life span in a transgenic rat model of tauopathy without causing neuronal loss or correlating with terminal NFT load.

    The European journal of neuroscience 2008;28;2;239-46

  • Relative resistance of Cdk5-phosphorylated CRMP2 to dephosphorylation.

    Cole AR, Soutar MP, Rembutsu M, van Aalten L, Hastie CJ, McLauchlan H, Peggie M, Balastik M, Lu KP and Sutherland C

    Neurosciences Institute, Division of Pathology and Neuroscience, University of Dundee, Ninewells Hospital, Dundee, Scotland, UK.

    Collapsin response mediator protein 2 (CRMP2) binds to microtubules and regulates axon outgrowth in neurons. This action is regulated by sequential phosphorylation by the kinases cyclin-dependent kinase 5 (Cdk5) and glycogen synthase kinase 3 (GSK3) at sites that are hyperphosphorylated in Alzheimer disease. The increased phosphorylation in Alzheimer disease could be due to increases in Cdk5 and/or GSK3 activity or, alternatively, through decreased activity of a CRMP phosphatase. Here we establish that dephosphorylation of CRMP2 at the residues targeted by GSK3 (Ser-518/Thr-514/Thr-509) is carried out by a protein phosphatase 1 family member in vitro, in neuroblastoma cells, and primary cortical neurons. Inhibition of GSK3 activity using insulin-like growth factor-1 or the highly selective inhibitor CT99021 causes rapid dephosphorylation of CRMP2 at these sites. In contrast, pharmacological inhibition of Cdk5 using purvalanol results in only a gradual and incomplete dephosphorylation of CRMP2 at the site targeted by Cdk5 (Ser-522), suggesting a distinct phosphatase targets this residue. A direct comparison of dephosphorylation at the Cdk5 versus GSK3 sites in vitro shows that the Cdk5 site is comparatively resistant to phosphatase treatment. The presence of the peptidyl-prolyl isomerase enzyme, Pin1, does not affect dephosphorylation of Ser-522 in vitro, in cells, or in Pin1 transgenic mice. Instead, the relatively high resistance of this site to phosphatase treatment is at least in part due to the presence of basic residues located nearby. Similar sequences in Tau are also highly resistant to phosphatase treatment. We propose that relative resistance to phosphatases might be a common feature of Cdk5 substrates and could contribute to the hyperphosphorylation of CRMP2 and Tau observed in Alzheimer disease.

    Funded by: Biotechnology and Biological Sciences Research Council: C18727; Medical Research Council

    The Journal of biological chemistry 2008;283;26;18227-37

  • A new function of microtubule-associated protein tau: involvement in chromosome stability.

    Rossi G, Dalprà L, Crosti F, Lissoni S, Sciacca FL, Catania M, Di Fede G, Mangieri M, Giaccone G, Croci D and Tagliavini F

    Department of Neuropathology, Neurological Institute Carlo Besta, Milano, Italy. grossi@istituto-besta.it

    Tau is a microtubule-associated protein that promotes assembly and stabilization of cytoskeleton microtubules. It is mostly expressed in neuronal and glial cells but it is also present in non-neural cells such as fibroblasts and lymphocytes. An altered tau produces cytoskeleton pathology resulting in neurodegenerative diseases such as Alzheimer's disease and tauopathies. Tau has been suggested to be a multifunctional protein, due to its localization in different cellular compartments. However its further functions are still unclear. We analyzed the distribution of tau in human skin fibroblasts showing its localization in the nucleus and along mitotic chromosomes. Then, we investigated if an altered tau, such as the P301L mutated protein associated with frontotemporal dementia, could produce nuclear pathology. We found that patients carrying the mutation consistently had several chromosome aberrations in their fibroblasts and lymphocytes: chromosome and chromatid breakages or gaps, aneuploidies, translocations, in addition to chromatin bridges and decondensed chromosomes. Our findings argue for a role of tau in chromosome stability by means of its interaction with both microtubules and chromatin.

    Cell cycle (Georgetown, Tex.) 2008;7;12;1788-94

  • Variation in MAPT is associated with cerebrospinal fluid tau levels in the presence of amyloid-beta deposition.

    Kauwe JS, Cruchaga C, Mayo K, Fenoglio C, Bertelsen S, Nowotny P, Galimberti D, Scarpini E, Morris JC, Fagan AM, Holtzman DM and Goate AM

    Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.

    There is substantial evidence that cerebrospinal fluid (CSF) levels of both Abeta42 and tau/ptau are promising biomarkers for Alzheimer's disease (AD). We show that both Abeta and tau exhibit more than 10-fold interindividual variation in CSF levels suggesting that these biomarkers may also be effectively used as endophenotypes for genetic studies of AD. To test the role of common variation in the gene encoding microtubule associated protein tau (MAPT) in influencing CSF tau/ptau levels, we genotyped 21 MAPT single nucleotide polymorphisms (SNPs) in 313 individuals and tested for association with CSF tau/ptau levels. We identified alleles of several SNPs that show association with increased CSF tau/ptau levels. When CSF Abeta42 levels were used to stratify the sample into those with and without likely Abeta deposition in the brain the association was only observed in individuals with evidence of Abeta deposition. This association was replicated in an independent CSF series. When these SNPs were evaluated in a late-onset AD case control series the alleles associated with higher CSF tau/ptau were associated with an earlier age at onset but had no effect on risk for AD. In vivo gene expression studies show that these alleles are associated with increased MAPT mRNA levels in individuals with evidence of brain Abeta deposition. This endophenotype-based approach provides evidence for a gene (MAPT SNPs)-physiological environment (Abeta deposition) interaction that places changes in CSF tau after Abeta deposition and suggest that this interaction predisposes for the development of tauopathy and accelerated disease progression.

    Funded by: NCATS NIH HHS: UL1 TR000448; NCRR NIH HHS: 1 KL2 RR 024994-01, 1 TL1 RR024995-01, 1 UL1 RR024992-01; NIA NIH HHS: P01-AG026276, P01-AG03991, P50-AG05681, R01-AG16208; NIMH NIH HHS: T32 MH14677; NINDS NIH HHS: P30-NS057105

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;23;8050-4

  • Co-localization of amyloid beta and tau pathology in Alzheimer's disease synaptosomes.

    Fein JA, Sokolow S, Miller CA, Vinters HV, Yang F, Cole GM and Gylys KH

    School of Nursing, University of California at Los Angeles School of Medicine, Sepulveda Veterans Administration Medical Center, Los Angeles, California 90095-6919, USA.

    The amyloid cascade hypothesis proposes that amyloid beta (Abeta) pathology precedes and induces tau pathology, but the neuropathological connection between these two lesions has not been demonstrated. We examined the regional distribution and co-localization of Abeta and phosphorylated tau (p-tau) in synaptic terminals of Alzheimer's disease brains. To quantitatively examine large populations of individual synaptic terminals, flow cytometry was used to analyze synaptosomes prepared from cryopreserved Alzheimer's disease tissue. An average 68.4% of synaptic terminals in the Alzheimer's disease cohort (n = 11) were positive for Abeta, and 32.3% were positive for p-tau; Abeta and p-tau fluorescence was lowest in cerebellum. In contrast to synaptic p-tau, which was highest in the entorhinal cortex and hippocampus (P = 0.004), synaptic Abeta fluorescence was significantly lower in the entorhinal cortex and hippocampus relative to neocortical regions (P = 0.0003). Synaptic Abeta and p-tau fluorescence was significantly correlated (r = 0.683, P < 0.004), and dual-labeling experiments demonstrated that 24.1% of Abeta-positive terminals were also positive for p-tau, with the highest fraction of dual labeling (39.3%) in the earliest affected region, the entorhinal cortex. Western blotting experiments show a significant correlation between synaptic Abeta levels measured by flow cytometry and oligomeric Abeta species (P < 0.0001). These results showing overlapping Abeta and tau pathology are consistent with a model in which both synaptic loss and dysfunction are linked to a synaptic amyloid cascade within the synaptic compartment.

    Funded by: NCI NIH HHS: CA 16042; NIA NIH HHS: 050 AG05142, 5AG016570, AG18879, P50 AG 16570; NIAID NIH HHS: AI 28697; NINDS NIH HHS: NS43946

    The American journal of pathology 2008;172;6;1683-92

  • Elevated cerebrospinal fluid tau protein levels in Wernicke's encephalopathy.

    Matsushita S, Miyakawa T, Maesato H, Matsui T, Yokoyama A, Arai H, Higuchi S and Kashima H

    National Hospital Organization, Kurihama Alcoholism Center, Yokosuka, Kanagawa, Japan. shiguchi@wa2.so-net.ne.jp

    Objective: Limited neuronal cell loss is seen in the neuropathology of Wernicke's encephalopathy (WE), but the extent of neuronal damage has not been well studied. Moreover, there is still a debate as to whether alcohol itself causes brain damage in humans. Although, it is difficult to examine the extent of neuronal damage in living patients, recent studies have revealed that total tau protein levels in the cerebrospinal fluid (CSF) reflect the rate of neuronal degeneration. Therefore, we hypothesized that the elevated CSF total tau in patients with WE was due to neuronal damage and thus we examined CSF total tau protein in patients with WE, as well as in those with alcohol withdrawal delirium (WD) and Korsakoff syndrome (KS). We also examined CSF total tau in nonalcohol dependent patients with Alzheimer's disease (AD) as a disease control.

    Methods: CSF samples were obtained from 13 acute WE patients with alcohol dependence, 9 WD patients with alcohol dependence and 16 KS patients with alcohol dependence, and from 20 nonalcohol dependent AD patients. CSF was also obtained from 10 of the WE patients after their disease had progressed to the chronic stage. CSF tau protein levels in all samples were determined by sandwich enzyme-linked immunosorbent assay. Tau phosphorylated at threonine 181 (p-tau(181)) and amyloid beta-protein ending at amino acid 42 (A beta 42) in CSF were also determined for comparison between acute WE with AD.

    Results: Total tau was significantly elevated in acute WE and decreased on long-term follow-up, but was not elevated in WD or KS. The patterns of p-tau(181) and A beta 42 differed between acute WE and AD.

    Conclusions: Intense neuronal cell death occurs transiently in WE, and the mechanism differs from that in AD. Neuronal damage is generally unaccompanied in WD. These results suggest that CSF total tau is a useful biological marker for WE.

    Alcoholism, clinical and experimental research 2008;32;6;1091-5

  • Parkin mediates the degradation-independent ubiquitination of Hsp70.

    Moore DJ, West AB, Dikeman DA, Dawson VL and Dawson TM

    Institute for Cell Engineering, and Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. djmoore@jhmi.edu

    Mutations in the parkin gene cause autosomal recessive, juvenile-onset parkinsonism. Parkin is an E3 ubiquitin ligase that mediates the ubiquitination of protein substrates. Disease-associated mutations cause a loss-of-function of parkin which may compromise the poly-ubiquitination and proteasomal degradation of specific protein substrates, potentially leading to their deleterious accumulation. Here, we identify the molecular chaperones, Hsp70 and Hsc70, as substrates for parkin. Parkin mediates the ubiquitination of Hsp70 both in vitro and in cultured cells. Parkin interacts with Hsp70 via its second RING finger domain and mutations in/near this domain compromise Hsp70 ubiquitination. Ubiquitination of Hsp70 fails to alter its steady-state levels or turnover, nor does it promote its proteasomal degradation. Consistent with this observation, Hsp70 levels remain unaltered in brains from parkin-deficient autosomal recessive, juvenile-onset parkinsonism subjects, whereas alternatively, Hsp70 levels are elevated in the detergent-insoluble fraction of sporadic Parkinson's disease/dementia with Lewy bodies brains. Parkin mediates the multiple mono-ubiquitination of Hsp70/Hsc70 consistent with a degradation-independent role for this ubiquitin modification. Our observations support a novel functional relationship between parkin and Hsc/Hsp70 and support the notion that parkin is a multi-purpose E3 ubiquitin ligase capable of modifying proteins either via attachment of alternatively linked poly-ubiquitin chains or through multiple mono-ubiquitination to achieve alternate biological outcomes.

    Funded by: NINDS NIH HHS: K99/R00 NS058111, P50 NS38377, R00 NS058111, R01 NS048206, R01 NS064934

    Journal of neurochemistry 2008;105;5;1806-19

  • Complementary dimerization of microtubule-associated tau protein: Implications for microtubule bundling and tau-mediated pathogenesis.

    Rosenberg KJ, Ross JL, Feinstein HE, Feinstein SC and Israelachvili J

    Department of Physics, University of California, Santa Barbara, CA 93106, USA.

    Tau is an intrinsically unstructured microtubule (MT)-associated protein capable of binding to and organizing MTs into evenly spaced parallel assemblies known as "MT bundles." How tau achieves MT bundling is enigmatic because each tau molecule possesses only one MT-binding region. To dissect this complex behavior, we have used a surface forces apparatus to measure the interaction forces of the six CNS tau isoforms when bound to mica substrates in vitro. Two types of measurements were performed for each isoform: symmetric configuration experiments measured the interactions between two tau-coated mica surfaces, whereas "asymmetric" experiments examined tau-coated surfaces interacting with a smooth bare mica surface. Depending on the configuration (of which there were 12), the forces were weakly adhesive, strongly adhesive, or purely repulsive. The equilibrium spacing was determined mainly by the length of the tau projection domain, in contrast to the adhesion force/energy, which was determined by the number of repeats in the MT-binding region. Taken together, the data are incompatible with tau acting as a monomer; rather, they indicate that two tau molecules associate in an antiparallel configuration held together by an electrostatic "zipper" of complementary salt bridges composed of the N-terminal and central regions of each tau monomer, with the C-terminal MT-binding regions extending outward from each end of the dimeric backbone. This tau dimer determines the length and strength of the linker holding two MTs together and could be the fundamental structural unit of tau, underlying both its normal and pathological action.

    Funded by: NINDS NIH HHS: R01 NS 35010, R01 NS035010

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;21;7445-50

  • Nucleation-dependent tau filament formation: the importance of dimerization and an estimation of elementary rate constants.

    Congdon EE, Kim S, Bonchak J, Songrug T, Matzavinos A and Kuret J

    Center for Molecular Neurobiology, Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA.

    Filamentous inclusions composed of the microtubule-associated protein tau are found in Alzheimer disease and other tauopathic neurodegenerative diseases, but the mechanisms underlying their formation from full-length protein monomer under physiological conditions are unclear. To address this issue, the fibrillization of recombinant full-length four-repeat human tau was examined in vitro as a function of time and submicromolar tau concentrations using electron microscopy assay methods and a small-molecule inducer of aggregation, thiazine red. Data were then fit to a simple homogeneous nucleation model with rate constant constraints established from filament dissociation rate, critical concentration, and mass-per-unit length measurements. The model was then tested by comparing the predicted time-dependent evolution of length distributions to experimental data. Results indicated that once assembly-competent conformations were attained, the rate-limiting step in the fibrillization pathway was tau dimer formation. Filament elongation then proceeded by addition of tau monomers to nascent filament ends. Filaments isolated at reaction plateau contained approximately 2 tau protomers/beta-strand spacing on the basis of mass-per-unit length measurements. The model suggests four key steps in the aggregation pathway that must be surmounted for tau filaments to form in disease.

    Funded by: NIA NIH HHS: AG14452

    The Journal of biological chemistry 2008;283;20;13806-16

  • CSF phosporylated TAU protein levels correlate with cerebral glucose metabolism assessed with PET in Alzheimer's disease.

    Ceravolo R, Borghetti D, Kiferle L, Tognoni G, Giorgetti A, Neglia D, Sassi N, Frosini D, Rossi C, Petrozzi L, Siciliano G and Murri L

    Department of Neuroscience, University of Pisa, Via Roma 67, 56126 Pisa, Italy.

    One major goal of drug development would be the establishment of biomarkers as objective indicators of normal biological and pathogenetic processes, or pharmacological response to a therapeutic intervention. A potential approach is to investigate proteins in CSF linked to key neuropathological features of Alzheimer's disease (AD). Recently CSF phosphorylated-Tau (p-Tau) levels have been reported to reflect neurofibrillary changes within the brain of patients with AD, however the use of serial CSF investigations in order to monitor the disease progression is not applicable. PET with FDG reveals characteristic patterns in AD patients, however so far no correlation between in vivo metabolic information and pathological features has been reported. In the present study, we tested whether CSF Tau levels correlate with metabolic rate for glucose consumption in a cohort of 28 AD patients. We found a statistically significative correlation between both CSF total and p-TAU protein and relative metabolic indexes obtained from 18FDG-PET scans in parietal, temporal and occipital lobes bilaterally. These results indicate the existence of a correlation between impairment of cerebral metabolism, estimated throughout FDG-PET, and CSF Tau protein levels.

    Brain research bulletin 2008;76;1-2;80-4

  • Parkin polymorphisms in progressive supranuclear palsy.

    Ros R, Ampuero I and García de Yébenes J

    Banco De Tejidos Para Investigaciones Neurológicas, Madrid, Spain.

    Progressive supranuclear palsy (PSP) is a mostly sporadic disorder of unknown pathogenesis. Familial PSP have been reported related to mutations of microtubule-associated protein tau (MAPT). Mutations of the Park2 gene cause autosomal recessive parkinsonism with neuropathological findings consistent with neurofibrillary tangles and tau immunoreactive lesions. We analysed the presence of MAPT and Park2 mutations and polymorphisms in sporadic and familial PSP. No patients had mutations of Park2 or MAPT but there was genetic association for the polymorphism Val380Leu in sporadic and familial PSP. Leu380 is associated with less risk of familial or sporadic PSP.

    Journal of the neurological sciences 2008;268;1-2;176-8

  • CSF biomarkers in frontotemporal lobar degeneration with known pathology.

    Bian H, Van Swieten JC, Leight S, Massimo L, Wood E, Forman M, Moore P, de Koning I, Clark CM, Rosso S, Trojanowski J, Lee VM and Grossman M

    Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.

    Objective: To evaluate the diagnostic value of CSF biomarkers in patients with known pathology due to frontotemporal lobar degeneration (FTLD).

    Background: It is important to distinguish FTLD from other neurodegenerative diseases like Alzheimer disease (AD), but this may be difficult clinically because of atypical presentations.

    Methods: Patients with FTLD (n = 30) and AD (n = 19) were identified at autopsy or on the basis of genetic testing at University of Pennsylvania and Erasmus University Medical Center. CSF was obtained during a diagnostic lumbar puncture and was analyzed using assays for total tau and amyloid-beta 1-42 (A beta(42)). Patients also were assessed with a brief neuropsychological battery.

    Results: CSF total tau level and the ratio of CSF total tau to A beta(42) (tau/A beta(42)) were significantly lower in FTLD than in AD. Receiver operating characteristic curve analyses confirmed that the CSF tau/A beta(42) ratio is sensitive and specific at discriminating between FTLD and AD, and is more successful at this than CSF total tau alone. Although some neuropsychological measures are significantly different in autopsy-proven FTLD and AD, combining these neuropsychological measures with CSF biomarkers did not improve the ability to distinguish FTLD from AD.

    Conclusions: The ratio of CSF tau/A beta(42) is a sensitive and specific biomarker at discriminating frontotemporal lobar degeneration from Alzheimer disease in patients with known pathology.

    Funded by: NIA NIH HHS: AG15116, AG17586, P01 AG017586-090001, R01 AG015116-10S1; NINDS NIH HHS: NS44266, P50 NS053488-020002, R01 NS044266, R01 NS044266-05

    Neurology 2008;70;19 Pt 2;1827-35

  • Accumulation of aspartic acid421- and glutamic acid391-cleaved tau in neurofibrillary tangles correlates with progression in Alzheimer disease.

    Basurto-Islas G, Luna-Muñoz J, Guillozet-Bongaarts AL, Binder LI, Mena R and García-Sierra F

    Department of Cell Biology, Center of Research and Advanced Studies of the IPN, Mexico City, Mexico.

    Truncations of tau protein at aspartic acid421 (D421) and glutamic acid391 (E391) residues are associated with neurofibrillary tangles (NFTs) in the brains of Alzheimer disease (AD) patients. Using immunohistochemistry with antibodies to D421- and E391-truncated tau (Tau-C3 and MN423, respectively), we correlated the presence of NFTs composed of these truncated tau proteins with clinical and neuropathologic parameters in 17 AD and 23 non-AD control brains. The densities of NFTs composed of D421- or E391-truncated tau correlated with clinical dementia index and Braak staging in AD. Glutamic acid391 tau truncation was prominent in the entorhinal cortex, whereas D421 truncation was prominent in the subiculum, suggesting that NFTs composed of either D421- or E391-truncated tau may be formed mutually exclusively in these areas. Both truncations were associated with the prevalence of the apolipoprotein E epsilon4 allele. By double labeling, intact tau in NFTs was commonly associated with D421-cleaved tau but not with E391-truncated tau; D421-cleaved tau was never associated with E391-truncated tau. These results indicate that tau is not randomly proteolyzed at different domains, and that proteolysis occurs sequentially from the C-terminus to inner regions of tau in AD progression. Identification of NFTs composed of tau at different stages of truncation may facilitate assessment of neurofibrillary pathology in AD.

    Funded by: NIA NIH HHS: P01 AG014449, R01 AG043375, T32 AG000257, T32 AG000257-10, Z01 AG000257

    Journal of neuropathology and experimental neurology 2008;67;5;470-83

  • Characterization of tau in cerebrospinal fluid using mass spectrometry.

    Portelius E, Hansson SF, Tran AJ, Zetterberg H, Grognet P, Vanmechelen E, Höglund K, Brinkmalm G, Westman-Brinkmalm A, Nordhoff E, Blennow K and Gobom J

    Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, University of Göteborg, Sahlgrenska University Hospital, S-431 80 Mölndal, Sweden. erik.portelius@neuro.gu.se

    The neurodegenerative disorder Alzheimer's disease (AD) is the most common cause of dementia in the elderly. The presence of neurofibrillary tangles, consisting of hyperphosphorylated tau protein, is one of the major neuropathologic characteristics of the disease, making this protein an attractive biomarker for AD and a possible target for therapy. Here, we describe an optimized immunoprecipitation mass spectrometry method that enables, for the first time, detailed characterization of tau in human cerebrospinal fluid. The identities of putative tau fragments were confirmed using nanoflow liquid chromatography and tandem mass spectrometry. Nineteen tryptic fragments of tau were detected, of which 16 are found in all tau isoforms while 3 represented unique tau isoforms. These results pave the way for clinical CSF studies on the tauopathies.

    Journal of proteome research 2008;7;5;2114-20

  • Coenzyme q induces tau aggregation, tau filaments, and Hirano bodies.

    Santa-Mara I, Santpere G, MacDonald MJ, Gomez de Barreda E, Hernandez F, Moreno FJ, Ferrer I and Avila J

    Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain.

    Tau aggregation is a common feature of tauopathies such as Alzheimer disease (AD). In AD, tau assembles into fibrillar polymers; it may also be present in other aberrant aggregates, including Hirano bodies. The mechanisms leading to tau polymerization in vivo are not understood. In this study, we found that coenzyme Q (ubiquinone) facilitates tau aggregation after binding to tau molecules at the region of the tau molecule involved in self-assembly. Consequently, after tau-tau interactions, this region is masked in fibrillar tau polymers. Further in vitro studies showed that ubiquinone facilitates the interaction of tau protein with actin to form structures that are morphologically similar to Hirano bodies. Finally, studies in AD brains show that Hirano bodies react with an antibody raised against ubiquinone, indicating that ubiquinone is a component of Hirano bodies. Taken together, the in vitro models and findings in AD suggest that in the presence of ubiquinone, Hirano bodies may result from the interaction of actin and other proteins, including tau.

    Journal of neuropathology and experimental neurology 2008;67;5;428-34

  • Tau haplotype influences cerebral perfusion pattern in frontotemporal lobar degeneration and related disorders.

    Borroni B, Perani D, Agosti C, Anchisi D, Paghera B, Archetti S, Alberici A, Di Luca M and Padovani A

    Department of Neurological Sciences, University of Brescia, Brescia, Italy. bborroni@inwind.it

    Objective: The modulating factors on phenotypic expression of frontotemporal lobar degeneration (FTLD) remain still unknown. The aim of this study was to determine whether tau genetic variability modulates the brain functional and the clinical phenotypic expression of FTLD.

    Clinical and neurological evaluations, a standardized neuropsychological assessments as well as a brain single photon emission tomography perfusion imaging studies were performed in 48 FTLD patients. Cerebral perfusion patterns were analysed according to H1 or H2 tau haplotypes by statistical parametric mapping and principal component analysis.

    Results: Two different patterns of cerebral dysfunction characterized the haplotypes, as hypoperfusion of frontal medial and cingulated cortex in H2-carriers and a prevalent involvement of posterior parietal regions in H1-carriers. Further, a significant increase of cerebrospinal fluid total tau and phospho tau levels was found in H2-carriers.

    Conclusions: These findings support a role of tau haplotype in modulating disease phenotype by influencing the hypoperfusion pattern and cerebrospinal fluid tau levels in FTLD.

    Acta neurologica Scandinavica 2008;117;5;359-66

  • The G389R mutation in the MAPT gene presenting as sporadic corticobasal syndrome.

    Rossi G, Marelli C, Farina L, Laurà M, Maria Basile A, Ciano C, Tagliavini F and Pareyson D

    Division of Neuropathology, IRCCS Foundation, "C. Besta" Neurological Institute, Milan, Italy.

    A few patients with mutations in the microtubule-associated protein tau gene (MAPT), affected by frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T), may clinically present with a corticobasal syndrome (CBS). We report a case of apparently sporadic CBS bearing a mutation in the MAPT gene so far associated with frontotemporal dementia (FTD) phenotype. The patient is a 41-year-old man with progressive asymmetric signs of cortical and basal ganglia involvement consistent with CBS. Magnetic resonance imaging showed asymmetric cortical atrophy and unusual corticospinal tract hyperintensity in T2-weighted images. Genetic testing revealed a heterozygous G to C mutation at the first base of codon 389 of the MAPT gene, changing glycine to arginine (G389R), in the patient and his unaffected elderly father. In conclusion, the MAPT G389R mutation shows phenotypic variability resulting in both FTD and CBS. The mutation also demonstrates incomplete penetrance. Corticospinal tract degeneration is an exceptional finding.

    Movement disorders : official journal of the Movement Disorder Society 2008;23;6;892-5

  • Alzheimer disease-like clinical phenotype in a family with FTDP-17 caused by a MAPT R406W mutation.

    Lindquist SG, Holm IE, Schwartz M, Law I, Stokholm J, Batbayli M, Waldemar G and Nielsen JE

    Memory Disorders Research Group, The Neuroscience Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. granhojlindquist@gmail.com

    We report clinical, molecular, neuroimaging and neuropathological features of a Danish family with autosomal dominant inherited dementia, a clinical phenotype resembling Alzheimer's disease and a pathogenic mutation (R406W) in the microtubule associated protein tau (MAPT) gene. Pre-symptomatic and affected family members underwent multidisciplinary (clinical, molecular, neuroimaging and neuropathological) examinations. Treatment with memantine in a family member with early symptoms, based on the clinical phenotype and the lack of specific treatment, appears to stabilize the disease course and increase the glucose metabolism in cortical and subcortical areas, as determined by serial [F(18)]FDG-PET scanning before and after initiation of treatment. Neuropathological examination of a second affected and mutation-positive family member showed moderate atrophy of the temporal lobes including the hippocampi. Microscopy revealed abundant numbers of tau-positive neurofibrillary tangles in all cortical areas and in some brainstem nuclei corresponding to a diagnosis of frontotemporal lobe degeneration on the basis of a MAPT mutation. The clinical and genetic heterogeneity of autosomal dominant inherited dementia must be taken into account in the genetic counselling and genetic testing of families with autosomal dominantly inherited dementia in general.

    European journal of neurology : the official journal of the European Federation of Neurological Societies 2008;15;4;377-85

  • Decrease of protein phosphatase 2A and its association with accumulation and hyperphosphorylation of tau in Down syndrome.

    Liang Z, Liu F, Iqbal K, Grundke-Iqbal I, Wegiel J and Gong CX

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314-6399, USA.

    Virtually all individuals with Down syndrome (DS) develop neurofibrillary tangles, a characteristic brain lesion of Alzheimer's disease (AD), when they reach the fourth decade of life. In AD, neurofibrillary tangles are thought to result from abnormal hyperphosphorylation of tau protein, which, in turn, can result from down-regulation of protein phosphatase (PP) 2A, a major brain tau phosphatase. The abnormal hyperphosphorylation of tau in DS had not yet been characterized, and its causes were not understood. In this study, by using quantitative Western blot analysis, we found that the level of the catalytic subunit of PP2A, but not of PP1, PP2B or PP5, was dramatically decreased. The decrease of PP2A level correlated negatively to tau level and tau phosphorylation at several abnormal hyperphosphorylation sites, including Ser199, Thr205, Thr212, Ser262, Ser396 and Ser422. Our results indicate that PP2A is down-regulated in DS brain and suggest that this down-regulation might be involved in the abnormal hyperphosphorylation and accumulation of tau.

    Funded by: NIA NIH HHS: R01 AG027429, R01 AG027429-02, R01 AG027429-03; NICHD NIH HHS: R01 HD043960, R01 HD43960

    Journal of Alzheimer's disease : JAD 2008;13;3;295-302

  • Exploring gene-environment interactions in Parkinson's disease.

    McCulloch CC, Kay DM, Factor SA, Samii A, Nutt JG, Higgins DS, Griffith A, Roberts JW, Leis BC, Montimurro JS, Zabetian CP and Payami H

    Applied Statistics Laboratory, General Electric Global Research Center, Niskayuna, NY, USA.

    The objective of this study was to explore combined effects of four candidate susceptibility genes and two exposures on Parkinson's disease (PD) risk; namely, alpha-synuclein (SNCA) promoter polymorphism REP1, microtubule-associated protein tau (MAPT) H1/H2 haplotypes, apolipoprotein E (APOE) epsilon2/epsilon3/epsilon4 polymorphism, ubiquitin carboxy-terminal esterase L1 (UCHL1) S18Y variant, cigarette smoking and caffeinated coffee consumption. 932 PD patients and 664 control subjects from the NeuroGenetics Research Consortium, with complete data on all six factors, were studied. Uniform protocols were used for diagnosis, recruitment, data collection and genotyping. A logistic regression model which included gene-exposure interactions was applied. Likelihood ratio tests (LRTs) were used for significance testing and Bayesian inference was used to estimate odds ratios (ORs). MAPT (P = 0.007), SNCA REP1 (P = 0.012), smoking (P = 0.001), and coffee (P = 0.011) were associated with PD risk. Two novel interactions were detected: APOE with coffee (P = 0.005), and REP1 with smoking (P = 0.021). While the individual main effects were modest, each yielding OR < 1.6, the effects were cumulative, with some combinations reaching OR = 12.6 (95% CI: 5.9-26.8). This study provides evidence for the long-held notion that PD risk is modulated by cumulative and interactive effects of genes and exposures. Furthermore, the study demonstrates that while interaction studies are useful for exploring risk relationships that might otherwise go undetected, results should be interpreted with caution because of the inherent loss of power due to multiple testing. The novel findings of this study that warrant replication are the evidence for interaction of coffee with APOE, and of smoking with REP1 on PD risk.

    Funded by: NINDS NIH HHS: K08-NS044138, NS R01-36960

    Human genetics 2008;123;3;257-65

  • Extracellular tau promotes intracellular calcium increase through M1 and M3 muscarinic receptors in neuronal cells.

    Gómez-Ramos A, Díaz-Hernández M, Rubio A, Miras-Portugal MT and Avila J

    Centro de Biología Molecular Severo Ochoa, C/Nicolás Cabrera no 1, Campus de Cantoblanco, 28049, Madrid, Spain.

    Extracellular tau promotes an increase in the level of intracellular calcium in cultured neuronal cells. We have found that such increase is impaired in the presence of antagonists of muscarinic receptors. In order to identify the nature of those receptors, we have tested the effect of different specific muscarinic receptor antagonists on tau promoted calcium increase. Our results indicate that the increase does not take place in the presence of antagonists of muscarinic (mainly M1 and M3) receptors. A similar increase in intracellular calcium was found in non-neuronal cells transfected with cDNA of M1 and M3 muscarinic receptors when tau was added. These results suggest that observed effect of tau protein on neuronal (neuroblastoma and primary cultures of hippocampal and cortical neurons) cells is through M1 and M3 muscarinic receptors. Therefore blocking M1 and for M3 receptors, by using specific receptor antagonists, can prevent that tau toxic effect that could take place in tauopathies.

    Molecular and cellular neurosciences 2008;37;4;673-81

  • Linkage-dependent contribution of repeat peptides to self-aggregation of three- or four-repeat microtubule-binding domains in tau protein.

    Okuyama K, Nishiura C, Mizushima F, Minoura K, Sumida M, Taniguchi T, Tomoo K and Ishida T

    Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.

    Although one of the priorities in Alzheimer's research is to clarify the filament formation mechanism for the tau protein, it is still unclear how it is transformed from a normal structure in a neuron. To examine the linkage-dependent contribution of each repeat peptide (R1-R4) to filament formation of the three- or four-repeat microtubule-binding domain (MBD) in the tau protein, four two-repeat peptides (R12, R13, R23 and R34) and two three-repeat peptides (R123 and R234) were prepared, and their in vitro self-aggregation was investigated by thioflavin S fluorescence and circular dichroism measurements, and by electron microscopy in neutral buffer (pH 7.6). Comparison of these aggregation behaviors with previous results for single-repeat peptides and wild-type 3RMBD (R134) and 4RMBD (R1234) indicated that (a) the two-repeat R23, not the R2 or R3 single repeat, forms the core structure in self-aggregation of 4RMBD, whereas that of 3RMBD comprises the R3 single repeat, (b) co-existence of R1 and R4 repeats is necessary for the aggregation behavior inherent in 3RMBD and 4RMBD, whereas the R1 or R4 repeat alone functions as a repressor or modifier of the filament formation, (c) 4RMBD aggregation is accompanied by R1-driven transition from random and alpha-helix structures to a beta-sheet structure, whereas 3RMBD aggregation involves three-repeat R134-specific transition from a random structure to an alpha-helix structure without the participation of a beta-sheet structure, and (d) the peptides that include the R1 repeat form a long filament irrespective of the absence or presence of the R4 repeat, whereas those that include the R4 repeat, but not the R1 repeat, form a relatively short filament. To the best of our knowledge, a systematic study of the linkage-dependent contribution of each repeat peptide to the paired helical filament formation of tau MBD has not been carried out previously, and thus the present information is useful for understanding the essence of the filament formation of tau MBD.

    The FEBS journal 2008;275;7;1529-39

  • Refining frontotemporal dementia with parkinsonism linked to chromosome 17: introducing FTDP-17 (MAPT) and FTDP-17 (PGRN).

    Boeve BF and Hutton M

    Division of Behavioral Neurology, Department of Neurology, Mayo Clinic, 200 First St SW, Rochester, Minnesota,55905, USa. bboeve@mayo.edu

    Frontotemporal dementia with parkinsonism (FTDP) is a major neurodegenerative syndrome, particularly for those with symptoms beginning before age 65 years. A spectrum of degenerative disorders can present as sporadic or familial FTDP. Mutations in the gene encoding the microtubule-associated protein tau (MAPT; OMIM +157140) on chromosome 17 have been found in many kindreds with familial FTDP. Several other kindreds with FTDP had been linked to chromosome 17, but they had ubiquitin-positive inclusions rather than tauopathy pathology and no mutations in MAPT. This conundrum was solved in 2006 with the identification of mutations in the gene encoding progranulin (PGRN; OMIM *138945), which is only 1.7 Mb centromeric to MAPT on chromosome 17. In this review, we compare and contrast the demographic, clinical, radiologic, neuropathologic, genetic, and pathophysiologic features in patients with FTDP linked to mutations in MAPT and PGRN, highlighting the many similarities but also a few important differences. Our findings describe an intriguing oddity of nature in which 2 genes can cause a similar phenotype through apparently different mechanisms yet reside so near to each other on the same chromosome.

    Funded by: NIA NIH HHS: AG06786, AG07216, AG11378, AG16574, P50 AG016574, P50 AG016574-10, R01 AG011378, R01 AG011378-14, U01 AG006786, U01 AG006786-22

    Archives of neurology 2008;65;4;460-4

  • Tau expression levels from various adeno-associated virus vector serotypes produce graded neurodegenerative disease states.

    Klein RL, Dayton RD, Tatom JB, Diaczynsky CG and Salvatore MF

    Department of Pharmacology, Toxicology & Neuroscience, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA. klein@lsuhsc.edu

    Neurodegenerative diseases involving neurofibrillary tangle pathology are pernicious. By expressing the microtubule-associated protein tau, a major component of tangles, with a viral vector, we induce neuropathological sequelae in rats that are similar to those seen in human tauopathies. We tested several variants of the adeno-associated virus (AAV) vector for tau expression in the nigrostriatal system in order to develop models with graded onset and completeness. Whereas previous studies with AAV2 tau vectors produced partial lesions of the nigrostriatal system, AAV9 or AAV10 tau vectors were more robust. These vectors had formidable efficacy relative to 6-hydroxydopamine for dopamine loss in the striatum. Time-courses for tau transgene expression, dopamine loss and rotational behavior tracked the disease progression with the AAV9 tau vector. There was a nearly complete lesion over a delayed time-course relative to 6-hydroxydopamine, with a sequence of tau expression by 1 week, dopamine loss by 2 weeks and then behavior effect by 3-4 weeks. Relative to AAV2 or AAV8, tau expression from AAV9 or AAV10 peaked earlier and caused more dopamine loss. Varying vector efficiencies produced graded states of disease up to nearly complete. The disease models stemming from the AAV variants AAV9 or AAV10 may be useful for rapid drug screening, particularly for tau diseases that affect the nigrostriatal system, such as progressive supranuclear palsy.

    Funded by: NINDS NIH HHS: R01 NS048450, R01 NS048450-03

    The European journal of neuroscience 2008;27;7;1615-25

  • Tau-induced traffic jams reflect organelles accumulation at points of microtubule polar mismatching.

    Shemesh OA, Erez H, Ginzburg I and Spira ME

    Department of Neurobiology, Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.

    It is currently accepted that tau overexpression leads to impaired organelle transport and thus to neuronal degeneration. Nevertheless, the underlying mechanisms that lead to impaired organelle transport are not entirely clear. Using cultured Aplysia neurons and online confocal imaging of human tau, microtubules (MTs), the plus-end tracking protein - end-binding protein 3, retrogradely and anterogradely transported organelles, we found that overexpression of tau generates the hallmarks of human tau pathogenesis. Nevertheless, in contrast to earlier reports, we found that the tau-induced impairment of organelle transport is because of polar reorientation of the MTs along the axon or their displacement to submembrane domains. 'Traffic jams' reflect the accumulation of organelles at points of MT polar discontinuations or polar mismatching rather than because of MT depolymerization. Our findings offer a new mechanistic explanation for earlier observations, which established that tau overexpression leads to impaired retrograde and anterograde organelle transport, while the MT skeleton appeared intact.

    Traffic (Copenhagen, Denmark) 2008;9;4;458-71

  • Akt and CHIP coregulate tau degradation through coordinated interactions.

    Dickey CA, Koren J, Zhang YJ, Xu YF, Jinwal UK, Birnbaum MJ, Monks B, Sun M, Cheng JQ, Patterson C, Bailey RM, Dunmore J, Soresh S, Leon C, Morgan D and Petrucelli L

    Department of Molecular Pharmacology and Physiology and H. Lee Moffitt Cancer Center, University of South Florida, Tampa, FL 33612, USA. cdickey1@health.usf.edu

    A hallmark of the pathology of Alzheimer's disease is the accumulation of the microtubule-associated protein tau into fibrillar aggregates. Recent studies suggest that they accumulate because cytosolic chaperones fail to clear abnormally phosphorylated tau, preserving a pool of toxic tau intermediates within the neuron. We describe a mechanism for tau clearance involving a major cellular kinase, Akt. During stress, Akt is ubiquitinated and degraded by the tau ubiquitin ligase CHIP, and this largely depends on the Hsp90 complex. Akt also prevents CHIP-induced tau ubiquitination and its subsequent degradation, either by regulating the Hsp90/CHIP complex directly or by competing as a client protein with tau for binding. Akt levels tightly regulate the expression of CHIP, such that, as Akt levels are suppressed, CHIP levels also decrease, suggesting a potential stress response feedback mechanism between ligase and kinase activity. We also show that Akt and the microtubule affinity-regulating kinase 2 (PAR1/MARK2), a known tau kinase, interact directly. Akt enhances the activity of PAR1 to promote tau hyperphosphorylation at S262/S356, a tau species that is not recognized by the CHIP/Hsp90 complex. Moreover, Akt1 knockout mice have reduced levels of tau phosphorylated at PAR1/MARK2 consensus sites. Hence, Akt serves as a major regulator of tau biology by manipulating both tau kinases and protein quality control, providing a link to several common pathways that have demonstrated dysfunction in Alzheimer's disease.

    Funded by: NIA NIH HHS: K99 AG031291, K99 AG031291-01, K99-AG31291, P01 AG017216, R00 AG031291, R00 AG031291-02, R00 AG031291-02S1, R01-AG17216-08; NIDDK NIH HHS: R01 DK056886, R01-DK56886

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;9;3622-7

  • A distinct clinical, neuropsychological and radiological phenotype is associated with progranulin gene mutations in a large UK series.

    Beck J, Rohrer JD, Campbell T, Isaacs A, Morrison KE, Goodall EF, Warrington EK, Stevens J, Revesz T, Holton J, Al-Sarraj S, King A, Scahill R, Warren JD, Fox NC, Rossor MN, Collinge J and Mead S

    MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.

    Mutations in the progranulin gene (GRN) are a major cause of frontotemporal lobar degeneration with ubiquitin-positive, tau-negative inclusions (FTLD-U) but the distinguishing clinical and anatomical features of this subgroup remain unclear. In a large UK cohort we found five different frameshift and premature termination mutations likely to be causative of FTLD in 25 affected family members. A previously described 4-bp insertion mutation in GRN exon 2 comprised the majority of cases in our cohort (20/25), with four novel mutations being identified in the other five affected members. Additional novel missense changes were discovered, of uncertain pathogenicity, but deletion of the entire gene was not detected. The patient collection was investigated by a single tertiary referral centre and is enriched for familial early onset FTLD with a high proportion of patients undergoing neuropsychological testing, MRI and eventual neuropathological diagnosis. Age at onset was variable, but four mutation carriers presented in their 40s and when analysed as a group, the mean age at onset of disease in GRN mutation carriers was later than tau gene (MAPT) mutation carriers and duration of disease was shorter when compared with both MAPT and FTLD-U without mutation. The most common clinical presentation seen in GRN mutation carriers was behavioural variant FTLD with apathy as the dominant feature. However, many patients had language output impairment that was either a progressive non-fluent aphasia or decreased speech output consistent with a dynamic aphasia. Neurological and neuropsychological examination also suggests that parietal lobe dysfunction is a characteristic feature of GRN mutation and differentiates this group from other patients with FTLD. MR imaging showed evidence of strikingly asymmetrical atrophy with the frontal, temporal and parietal lobes all affected. Both right- and left-sided predominant atrophy was seen even within the same family. As a group, the GRN carriers showed more asymmetry than in other FTLD groups. All pathologically investigated cases showed extensive type 3 TDP-43-positive pathology, including frequent neuronal cytoplasmic inclusions, dystrophic neurites in both grey and white matter and also neuronal intranuclear inclusions. Finally, we confirmed a modifying effect of APOE-E4 genotype on clinical phenotype with a later onset in the GRN carriers suggesting that this gene has distinct phenotypic effects in different neurodegenerative diseases.

    Funded by: Medical Research Council: G0600676, G0601846, G0801306, G90/86, MC_U123160651, MC_U123182015, MC_U123192748; Wellcome Trust: 077133

    Brain : a journal of neurology 2008;131;Pt 3;706-20

  • Human tau protein forms complex with PrP and some GSS- and fCJD-related PrP mutants possess stronger binding activities with tau in vitro.

    Wang XF, Dong CF, Zhang J, Wan YZ, Li F, Huang YX, Han L, Shan B, Gao C, Han J and Dong XP

    State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Ying-Xin Rd 100, Beijing 100052, PR China.

    Microtubule associated protein tau is considered to play roles in some types of human transmissible spongiform encephalopathies (TSE). In this study, the full-length and several truncated human tau proteins were expressed from E. coli and purified. Using GST pull down, co-immunoprecipitation assay and tau-coated ELISA, the molecular interaction between tau protein and PrP was confirmed in the context of the full-length human tau. The N terminus (amino acids 1-91) and tandem repeats region (amino acids 186-283) of tau protein were responsible for the interaction with PrP. The octapeptide repeats within PrP directly affected the binding activity of PrP with tau. GSS-related mutant PrP102L and fCJD- related mutants with two and seven extra octarepeats showed more active binding capacity with tau than wild-type PrP. The molecular interactions between PrP and tau protein highlight a potential role of tau in the biological function of PrP and the pathogenesis of TSE.

    Molecular and cellular biochemistry 2008;310;1-2;49-55

  • The microtubule-associated protein tau is phosphorylated by Syk.

    Lebouvier T, Scales TM, Hanger DP, Geahlen RL, Lardeux B, Reynolds CH, Anderton BH and Derkinderen P

    Inserm, U643, Nantes, F-44000, France.

    Aberrant phosphorylation of tau protein on serine and threonine residues has been shown to be critical in neurodegenerative disorders called tauopathies. An increasing amount of data suggest that tyrosine phosphorylation of tau might play an equally important role in pathology, with at least three putative tyrosine kinases of tau identified to date. It was recently shown that the tyrosine kinase Syk could efficiently phosphorylate alpha-synuclein, the aggregated protein found in Parkinson's disease and other synucleinopathies. We report herein that Syk is also a tau kinase, phosphorylating tau in vitro and in CHO cells when both proteins are expressed exogenously. In CHO cells, we have also demonstrated by co-immunoprecipitation that Syk binds to tau. Finally, by site-directed mutagenesis substituting the tyrosine residues of tau with phenylalanine, we established that tyrosine 18 was the primary residue in tau phosphorylated by Syk. The identification of Syk as a common tyrosine kinase of both tau and alpha-synuclein may be of potential significance in neurodegenerative disorders and also in neuronal physiology. These results bring another clue to the intriguing overlaps between tauopathies and synucleinopathies and provide new insights into the role of Syk in neuronal physiology.

    Funded by: Medical Research Council: G0300408; Wellcome Trust

    Biochimica et biophysica acta 2008;1783;2;188-92

  • The tau S305S mutation causes frontotemporal dementia with parkinsonism.

    Skoglund L, Viitanen M, Kalimo H, Lannfelt L, Jönhagen ME, Ingelsson M, Glaser A and Herva R

    Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden. lena.skoglund@pubcare.uu.se

    Members of families with mutations in the tau gene are known to be heterogeneous in their clinical presentation, ranging from frontotemporal dementia to a clinical picture more resembling corticobasal degeneration or progressive supranuclear palsy. In this report, we describe a new phenotype for the tau S305S mutation, previously described as progressive supranuclear palsy. Clinically, the three affected family members showed alterations in personality and behaviour as well as cognitive decline and late levodopa-resistant parkinsonian symptoms, consistent with the diagnosis of frontotemporal dementia with parkinsonism linked to chromosome 17. One autopsied case displayed degeneration of the frontal and temporal lobes together with extensive tau pathology in both neurones and glial cells. Sarkosyl-soluble and -insoluble tau extracted from frontal cortex revealed a ratio shift with decreased levels of tau with three microtubule-binding repeats and increased levels of tau with four microtubule-binding repeats (4R tau). These findings provide further evidence for the clinical and pathological variation both within and between families with mutations in the tau gene. In addition, they support previous studies which demonstrate that the S305S mutation influences the splicing of tau exon 10 and results in an overproduction of 4R tau.

    European journal of neurology 2008;15;2;156-61

  • Neurogenesis and cell cycle-reactivated neuronal death during pathogenic tau aggregation.

    Schindowski K, Belarbi K, Bretteville A, Ando K and Buée L

    Inserm, U837, Place de Verdun, Lille Cedex, France.

    The aim of the present study was to investigate the relation between neurogenesis, cell cycle reactivation and neuronal death during tau pathology in a novel tau transgenic mouse line THY-Tau22 with two frontotemporal dementia with parkinsonism linked to chromosome-17 mutations in a human tau isoform. This mouse displays all Alzheimer disease features of neurodegeneration and a broad timely resolution of tau pathology with hyperphosphorylation of tau at younger age (up to 6 months) and abnormal tau phosphorylation and tau aggregation in aged mice (by 10 months). Here, we present a follow-up of cell cycle markers with aging in control and transgenic mice from different ages. We show that there is an increased neurogenesis during tau hyperphosphorylation and cell cycle events during abnormal tau phosphorylation and tau aggregation preceding neuronal death and neurodegeneration. However, besides phosphorylation, other mechanisms including tau mutations and changes in tau expression and/or splicing may be also involved in these mechanisms of cell cycle reactivation. Altogether, these data suggest that cell cycle events in THY-Tau22 are resulting from neurogenesis in young animals and cell death in older ones. It suggests that neuronal cell death in such models is much more complex than believed.

    Genes, brain, and behavior 2008;7 Suppl 1;92-100

  • In vivo imaging reveals dissociation between caspase activation and acute neuronal death in tangle-bearing neurons.

    Spires-Jones TL, de Calignon A, Matsui T, Zehr C, Pitstick R, Wu HY, Osetek JD, Jones PB, Bacskai BJ, Feany MB, Carlson GA, Ashe KH, Lewis J and Hyman BT

    MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.

    Accumulation of neurofibrillary tangles (NFTs) in Alzheimer's disease correlates with neuronal loss and cognitive decline, but the precise relationship between NFTs and neuronal death and downstream mechanisms of cell death remain unclear. Caspase cleaved products accumulate in tangles, implying that tangles may contribute to apoptotic neuronal death. To test this hypothesis, we developed methods using multiphoton imaging to detect both neurofibrillary pathology and caspase activation in the living mouse brain. We examined rTg4510 mice, a reversible mouse model of tauopathy that develops tangles and neuronal loss. Only a small percentage of imaged neurons were caspase activity positive, but the vast majority of the cells with active caspases contained NFTs. We next tested the hypothesis that caspase activation led to acute, apoptotic neuronal death. Caspase positive cell bodies did not degenerate over hours of imaging, despite the presence of activated executioner caspases. Suppression of the transgene, which stops ongoing death, did not suppress caspase activity. Finally, histochemical assessments revealed evidence of caspase-cleaved tau, but no TUNEL (terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling) positive or apoptotic nuclei. With the novel technique of observing NFTs and caspase activation in the living brain, we demonstrate that aggregated tau in neurons can be associated with caspase activation, but that caspase activation is not sufficient to cause acute neuronal death in this model.

    Funded by: NIA NIH HHS: AG00277, AG08487, AG26249, P50 AG005134, R01 AG026249, R01-AG26252; NIBIB NIH HHS: EB00768; NINDS NIH HHS: R01-NS46355

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2008;28;4;862-7

  • The tauopathy associated with mutation +3 in intron 10 of Tau: characterization of the MSTD family.

    Spina S, Farlow MR, Unverzagt FW, Kareken DA, Murrell JR, Fraser G, Epperson F, Crowther RA, Spillantini MG, Goedert M and Ghetti B

    Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.

    Multiple system tauopathy with presenile dementia (MSTD) is an inherited disease caused by a (g) to (a) transition at position +3 in intron 10 of Tau. It belongs to the spectrum of frontotemporal dementia and parkinsonism linked to chromosome 17 with mutations in Tau (FTDP-17T). Here we present the longitudinal clinical, neuropsychological, neuroimaging, neuropathological, biochemical and genetic characterization of the MSTD family. Presenting signs were consistent with the behavioural variant of frontotemporal dementia in 17 of 21 patients. Two individuals presented with an atypical form of progressive supranuclear palsy and two others with either severe postural imbalance or an isolated short-term memory deficit. Memory impairment was present at the onset in 15 patients, with word finding difficulties and stereotyped speech also being common. Parkinsonism was first noted 3 years after the onset of symptoms. Neuroimaging showed the most extensive grey matter loss in the hippocampus, parahippocampal gyrus and frontal operculum/insular cortex of the right hemisphere and, to a lesser extent, in the anterior cingulate gyrus, head of the caudate nucleus and the posterolateral orbitofrontal cortex and insular cortex bilaterally. Neuropathologically, progressive nerve cell loss, gliosis and coexistent neuronal and/or glial deposits consisting mostly of 4-repeat tau were present in frontal, cingulate, temporal and insular cortices, white matter, hippocampus, parahippocampus, basal ganglia, selected brainstem nuclei and spinal cord. Tau haplotyping indicated that specific haplotypes of the wild-type allele may act as modifiers of disease presentation. Quantitative neuroimaging has been used to analyse the progression of atrophy in affected individuals and for predicting disease onset in an asymptomatic mutation carrier. This multidisciplinary study provides a comprehensive description of the natural history of disease in one of the largest known families with FTDP-17T.

    Funded by: Medical Research Council: G0301152, MC_U105184291, MC_U105184319; NIA NIH HHS: AG10133, P30 AG010133, P30AG10133, U24 AG021886

    Brain : a journal of neurology 2008;131;Pt 1;72-89

  • APOE, APOE promoter, and Tau genotypes and risk for concussion in college athletes.

    Terrell TR, Bostick RM, Abramson R, Xie D, Barfield W, Cantu R, Stanek M and Ewing T

    Department of Family Medicine, Brody School of Medicine at East Carolina University, Greenville, North Carolina 27834, USA. tomterrell@earthlink.net

    Objective: To investigate associations of APOE, APOE promoter (G-219T), and tau protein exon 6 polymorphisms (47 and 53) and a history of self-reported concussion in college athletes.

    Design: Multi-center cross-sectional study.

    Setting: Male football and male and female soccer programs at the University of South Carolina, Jacksonville University, Benedict College, and the College of Charleston.

    Participants: Active 18- to 30-year-old (n = 195) intercollegiate male football players and male and female soccer players during 2001 and 2002.

    Written questionnaires and blood or mouthwash samples for DNA for genotyping by RFLP/PCR.

    Self-reported history of concussions over the previous 8 years.

    Results: A statistically significant, nearly 3-fold increase in risk of a history of concussion for those with the APOE promoter G-219T TT genotype relative to the GG genotype (OR, 2.8; 95% CI, 1.1 to 6.9) adjusted for age, sport, school, and years in their primary sport, a finding that was stronger for Cantu grade 2 and 3 concussions.

    Conclusions: These results suggest that college athletes with an APOE promoter G-219T TT genotype may be at increased risk for having a history of concussions, especially more severe concussions. Although there was some support for the possibility that the tau 53 polymorphism may be associated with increased risk of prior concussion (OR, 2.1; 95% CI, 0.3 to 14.5), there was no support for an association with APOE genotypes. The results of this cross-sectional study support the need for a prospective study of genetic factors, such as APOE promoter polymorphisms, and the incidence of and sequelae from concussions in college athletes.

    Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine 2008;18;1;10-7

  • The effect of a DeltaK280 mutation on the unfolded state of a microtubule-binding repeat in Tau.

    Huang A and Stultz CM

    Department of Electrical Engineering and Computer Science, Harvard-MIT Division of Health Sciences and Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America.

    Tau is a natively unfolded protein that forms intracellular aggregates in the brains of patients with Alzheimer's disease. To decipher the mechanism underlying the formation of tau aggregates, we developed a novel approach for constructing models of natively unfolded proteins. The method, energy-minima mapping and weighting (EMW), samples local energy minima of subsequences within a natively unfolded protein and then constructs ensembles from these energetically favorable conformations that are consistent with a given set of experimental data. A unique feature of the method is that it does not strive to generate a single ensemble that represents the unfolded state. Instead we construct a number of candidate ensembles, each of which agrees with a given set of experimental constraints, and focus our analysis on local structural features that are present in all of the independently generated ensembles. Using EMW we generated ensembles that are consistent with chemical shift measurements obtained on tau constructs. Thirty models were constructed for the second microtubule binding repeat (MTBR2) in wild-type (WT) tau and a DeltaK280 mutant, which is found in some forms of frontotemporal dementia. By focusing on structural features that are preserved across all ensembles, we find that the aggregation-initiating sequence, PHF6*, prefers an extended conformation in both the WT and DeltaK280 sequences. In addition, we find that residue K280 can adopt a loop/turn conformation in WT MTBR2 and that deletion of this residue, which can adopt nonextended states, leads to an increase in locally extended conformations near the C-terminus of PHF6*. As an increased preference for extended states near the C-terminus of PHF6* may facilitate the propagation of beta-structure downstream from PHF6*, these results explain how a deletion at position 280 can promote the formation of tau aggregates.

    PLoS computational biology 2008;4;8;e1000155

  • The extended tau haplotype and the age of onset of dementia in Down syndrome.

    Jones EL, Margallo-Lana M, Prasher VP and Ballard CG

    Wolfson Centre for Age-Related Disease, Guy's Campus, King's College London, London, UK. emma.3.jones@kcl.ac.uk

    Most people with Down syndrome (DS) develop Alzheimer's disease (AD). The extended tau haplotype has been linked to AD. In this study, we examined the haplotype's effect on the age of onset of AD in DS.

    Methods: People with DS were assessed for dementia. Genotyping was performed for the extended tau haplotype, APOE and a polymorphism in APP, attt(5-8).

    Results: Haplotype frequencies vary between those developing AD before 45 and those developing dementia after this age (p = 0.03). H1/H2 individuals are more likely to develop dementia before 45 than H1/H1 individuals (OR = 3, 95% CI = 1.01-8.91).

    Conclusion: Even in a condition driven by excess amyloid pathology, factors affecting tau are also important and should be considered as potential treatment targets.

    Dementia and geriatric cognitive disorders 2008;26;3;199-202

  • 14-3-3 zeta and tau genes interactively decrease Alzheimer's disease risk.

    Mateo I, Sánchez-Juan P, Rodríguez-Rodríguez E, Infante J, Fernández-Viadero C, Peña N, Berciano J and Combarros O

    Neurology Service and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Marqués de Valdecilla University Hospital, University of Cantabria, Santander, Spain.

    Abnormal tau hyperphosphorylation has been suggested as being one of the central events in the development of neurofibrillary tangles, which are one of the characteristic neuropathological lesions found in Alzheimer's disease (AD) brains. 14-3-3 zeta protein is associated with tau in brain and stimulates tau phosphorylation. In a case-control study in 293 AD patients and 396 healthy controls, we examined whether the combined gene effects between 14-3-3 zeta (intron 4, rs 983583) polymorphism and tau (intron 9, rs 2471738) polymorphism might be responsible for susceptibility to AD. Subjects carrying both the 14-3-3 zeta (intron 4, rs 983583) AA and the tau (intron 9, rs 2471738) CC genotypes had a two and a half times lower risk of developing AD than subjects without these risk genotypes (OR = 0.4, 95% CI = 0.2-0.8, p = 0.016). Considering synergistic effects between polymorphisms in tau phosphorylation related genes may help in determining the risk profile for AD.

    Dementia and geriatric cognitive disorders 2008;25;4;317-20

  • Alternative splicing of exon 10 in the tau gene as a target for treatment of tauopathies.

    Zhou J, Yu Q and Zou T

    Department of Medicine, Program in Neuroscience, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA. Jianhua.Zhou@umassmed.edu

    Tau aggregation is one of the major features in Alzheimer's disease and in several other tauopathies, including frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17), and progressive supranuclear palsy (PSP). More than 35 mutations in the tau gene have been identified from FTDP-17 patients. A group of these mutations alters splicing of exon 10, resulting in an increase in exon 10 inclusion into tau mRNA. Abnormal splicing with inclusion of exon 10 into tau mRNA has also been observed in PSP and AD patients. These results indicate that abnormal splicing of exon 10, leading to the production of tau with exon 10, is probably one of the mechanisms by which tau accumulates and aggregates in tauopathic brains. Therefore, modulation of exon 10 splicing in the tau gene could potentially be targeted to prevent tauopathies. To identify small molecules or compounds that could potentially be developed into drugs to treat tauopathies, we established a cell-based high-throughput screening assay. In this review, we will discuss how realistic, specific biological molecules can be found to regulate exon 10 splicing in the tau gene for potential treatment of tauopathies.

    BMC neuroscience 2008;9 Suppl 2;S10

  • In vivo and postmortem clinicoanatomical correlations in frontotemporal dementia and parkinsonism linked to chromosome 17.

    Ghetti B, Spina S, Murrell JR, Huey ED, Pietrini P, Sweeney B, Wassermann EM, Keohane C, Farlow MR and Grafman J

    Indiana Alzheimer Disease Center, Indiana University School of Medicine, Indianapolis, Ind. 46202, USA. bghetti@iupui.edu

    Background: Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is associated with mutations in the Microtubule-Associated Protein Tau(MAPT) gene or the Progranulin(PGRN) gene. MAPT mutations lead to widespread deposition of hyperphosphorylated tau protein (FTDP-17T). PGRN mutations are associated with ubiquitin- and TDP-43-positive inclusions in the frontotemporal cortex, striatum and hippocampus (FTDP-17U). Despite the differences, FTDP-17T and FTDP-17U share a largely overlapping clinical phenotype.

    Objective: To determine whether neuroimaging studies may allow an in vivo early differentiation between FTDP-17T and FTDP-17U.

    Methods: We studied 25 individuals affected with FTDP-17T associated with either the exon 10+3 (24 subjects) or the G335S (1 subject) MAPT mutation, as well as 3 FTDP-17U individuals, who were carriers of the A9D, IVS6-2A>G or R493X PGRN mutation. Neuroimaging studies, obtained along the course of the disease, were compared to the neuropathologic findings.

    Results: FTDP-17T cases were associated with symmetric frontotemporal atrophy. Behavioral changes constituted the predominant clinical presentation. Conversely, an asymmetric degenerative process was seen in all 3 PGRN cases, who presented with either corticobasal syndrome (A9D) or frontotemporal dementia and language deterioration (IVS6-2A>G and R493X).

    Conclusion: Neuroimaging data, in the early disease stage of FTDP-17, may offer the possibility of an early differentiation of FTDP-17T and FTDP-17U phenotypes, independent of the genetic analysis.

    Funded by: NIA NIH HHS: AG10133

    Neuro-degenerative diseases 2008;5;3-4;215-7

  • Mutational analysis in early-onset familial dementia in the Japanese population. The role of PSEN1 and MAPT R406W mutations.

    Ikeuchi T, Kaneko H, Miyashita A, Nozaki H, Kasuga K, Tsukie T, Tsuchiya M, Imamura T, Ishizu H, Aoki K, Ishikawa A, Onodera O, Kuwano R and Nishizawa M

    Department of Molecular Neuroscience, Brain Research Institute, Niigata University, Niigata, Japan. ikeuchi@bri.niigata-u.ac.jp

    Background: Three major causative genes have been implicated as the cause of early-onset familial Alzheimer's disease (AD): the amyloid precursor protein gene (APP), presenilin-1 (PSEN1) and PSEN2. Although rare, a tau-related dementia with mutations in the microtubule-associated protein tau gene (MAPT) has been identified in patients showing clinical presentations similar to those of AD.

    Methods: We performed mutational analysis of APP, PSEN1, PSEN2, and MAPT in 10 Japanese families with early-onset dementia clinically diagnosed as probable Alzheimer's disease.

    Results: In 4 index patients, we identified 4 missense PSEN1 mutations, namely, L286V, G378E, L381V, and L392V. The mean age at onset in the patients with PSEN1 mutations was 39 years. In 2 families, we found the R406W mutation in MAPT. The mean age at onset of the patients carrying the R406W mutation was 52 years, and they presented with the peculiar AD-like phenotype without apparent behavioral or language problems.

    Conclusion: These observations suggest that although PSEN1 mutations are the most frequent cause, the MAPT R406W mutation is an important cause of early-onset familial dementia clinically diagnosed as AD. Differentiation of patients with the MAPT mutation from AD patients by genetic testing would be meaningful, considering that a different therapeutic approach should be applied.

    Dementia and geriatric cognitive disorders 2008;26;1;43-9

  • Senile systemic amyloidosis affects 25% of the very aged and associates with genetic variation in alpha2-macroglobulin and tau: a population-based autopsy study.

    Tanskanen M, Peuralinna T, Polvikoski T, Notkola IL, Sulkava R, Hardy J, Singleton A, Kiuru-Enari S, Paetau A, Tienari PJ and Myllykangas L

    Department of Pathology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland. maarit.tanskanen@helsinki.fi

    Background: Senile systemic amyloidosis (SSA) is characterized by deposition of wild-type transthyretin (TTR)-based amyloid in parenchymal organs in elderly individuals. Previously, no population-based studies have been performed on SSA.

    Methods: Here we have studied the prevalence and risk factors for SSA in a Finnish autopsied population aged 85 or over, as part of the population-based Vantaa 85+ Autopsy Study (n = 256). The diagnosis of SSA was based on histological examination of myocardial samples stained with Congo red and anti-TTR immunohistochemistry. The genotype frequencies of 20 polymorphisms in 9 genes in subjects with and without SSA were compared.

    Results: The prevalence of SSA was 25%. SSA was associated with age, myocardial infarctions, the G/G (Val/Val) genotype of the exon 24 polymorphism in the alpha2-macroglobulin (alpha2M), and the H2 haplotype of the tau gene (P-values 0.002, 0.004, 0.042, and 0.016).

    Conclusion: This population-based study shows that SSA is very common in old individuals, affecting one-quarter of people aged over 85 years. Myocardial infarctions and variation in the genes for alpha2M and tau may be associated with SSA.

    Funded by: Medical Research Council: G0701075

    Annals of medicine 2008;40;3;232-9

  • Synergistic effect of heme oxygenase-1 and tau genetic variants on Alzheimer's disease risk.

    Mateo I, Sánchez-Juan P, Rodríguez-Rodríguez E, Infante J, Vázquez-Higuera JL, García-Gorostiaga I, Berciano J and Combarros O

    Neurology Service, University Hospital Marqués de Valdecilla, University of Cantabria, Santander, Spain.

    Oxidative stress plays a role in tau hyperphosphorylation and the development of neurofibrillary tangles (NFT). In Alzheimer's disease (AD) brain, accumulation of hyperphosphorylated tau in NFT is associated with the induction of heme oxygenase-1 (HO-1), a potent antioxidant that downregulates the production of tau. In a case-control study of 300 AD patients and 360 healthy controls, we examined whether the combined gene effects between HO-1 (-413, rs2071746) and tau (5' of exon 1, rs242557) polymorphisms might be responsible for susceptibility to AD. Subjects carrying both the HO-1 (-413) TT and the tau (5' of exon 1) AA genotypes had a more than 6.5-time higher risk of developing AD than subjects without these risk genotypes (OR = 6.65, 95% CI 1.12-39.29; p = 0.037). These data support a role for tau-related genes in the risk of AD.

    Dementia and geriatric cognitive disorders 2008;26;4;339-42

  • BAG-1 associates with Hsc70.Tau complex and regulates the proteasomal degradation of Tau protein.

    Elliott E, Tsvetkov P and Ginzburg I

    Department of Neurobiology, Weizmann Insitute of Science, Rehovot, Israel 76100.

    Intraneuronal accumulation of phosphorylated Tau protein is a molecular pathology found in many forms of dementia, including Alzheimer disease. Research into possible mechanisms leading to the accumulation of modified Tau protein and the possibility of removing Tau protein from the system have revealed that the chaperone protein system can interact with Tau and mediate its degradation. Hsp70/Hsc70, a member of the chaperone protein family, interacts with Tau protein and mediates proper folding of Tau and can promote degradation of Tau protein under certain circumstances. However, because Hsp70/Hsc70 has many binding partners that can mediate its activity, there is still much to discover about how Hsp70 acts in vivo to regulate Tau protein. BAG-1, an Hsp70/Hsc70 binding partner, has been implicated as a mediator of neuronal function. In this work we show that BAG-1 associates with Tau protein in an Hsc70-dependent manner. Overexpression of BAG-1 induced an increase in Tau levels, which is shown to be due to an inhibition of protein degradation. We further show that BAG-1 can inhibit the degradation of Tau protein by the 20 S proteasome but does not affect the ubiquitination of Tau protein. RNA-mediated interference depletion of BAG-1 leads to a decrease in total Tau protein levels as well as promoting hyperphosphorylation of the remaining protein. Induction of Hsp70 by heat shock enhanced the increase of Tau levels in cells overexpressing BAG-1 but induced a decrease of Tau levels in cells that were depleted of BAG-1. Finally, BAG-1 is highly expressed in neurons bearing Tau tangles in a mouse model of Alzheimer disease. This data suggests a molecular mechanism through which Tau protein levels are regulated in the cell and possible consequences for the pathology and treatment of Alzheimer disease.

    The Journal of biological chemistry 2007;282;51;37276-84

  • Taurine, an inducer for tau polymerization and a weak inhibitor for amyloid-beta-peptide aggregation.

    Santa-María I, Hernández F, Moreno FJ and Avila J

    Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.

    Taurine is an abundant aminoacid present in brain. Its concentration is decreased in the brain of Alzheimer's disease (AD) patients. The chemical structure of taurine is similar to 3-amino-1-propanesulfonic acid, a known compound which interferes with beta-amyloid peptide aggregation. Here, we have tested if taurine show similar properties. Taurine slightly decreases beta-amyloid peptide aggregation at a milimolar concentration. At that concentration, taurine favours the assembly of tau protein into fibrillars polymers. Thus, it is proposed that the negative charge present in taurine may be involved in the binding to tau protein, facilitating its assembly. In addition, the possible role of taurine in Alzheimer disease is commented.

    Neuroscience letters 2007;429;2-3;91-4

  • Hyperphosphorylated tau in parahippocampal cortex impairs place learning in aged mice expressing wild-type human tau.

    Kimura T, Yamashita S, Fukuda T, Park JM, Murayama M, Mizoroki T, Yoshiike Y, Sahara N and Takashima A

    Laboratorty for Alzheimer's Disease, RIKEN Brain Science Institute, Wako, Saitama, Japan.

    To investigate how tau affects neuronal function during neurofibrillary tangle (NFT) formation, we examined the behavior, neural activity, and neuropathology of mice expressing wild-type human tau. Here, we demonstrate that aged (>20 months old) mice display impaired place learning and memory, even though they do not form NFTs or display neuronal loss. However, soluble hyperphosphorylated tau and synapse loss were found in the same regions. Mn-enhanced MRI showed that the activity of the parahippocampal area is strongly correlated with the decline of memory as assessed by the Morris water maze. Taken together, the accumulation of hyperphosphorylated tau and synapse loss in aged mice, leading to inhibition of neural activity in parahippocampal areas, including the entorhinal cortex, may underlie place learning impairment. Thus, the accumulation of hyperphosphorylated tau that occurs before NFT formation in entorhinal cortex may contribute to the memory problems seen in Alzheimer's disease (AD).

    The EMBO journal 2007;26;24;5143-52

  • No evidence for association between tau gene haplotypic variants and susceptibility to Creutzfeldt-Jakob disease.

    Sánchez-Juan P, Bishop MT, Green A, Giannattasio C, Arias-Vasquez A, Poleggi A, Knight RS and van Duijn CM

    Institute for Formation and Research of the Fundación Marqués de Valdecilla (IFIMAV), Santander, Spain. psanchez@humv.es

    Background: A polymorphism at codon 129 of the prion protein gene (PRNP) is the only well-known genetic risk factor for Creutzfeldt-Jakob disease (CJD). However, there is increasing evidence that other loci outside the PRNP open reading frame might play a role in CJD aetiology as well.

    Methods: We studied tau protein gene (MAPT) haplotypic variations in a population of sporadic and variant CJD patients. We tested 6 MAPT haplotype tagging SNPs (htSNPs) in a Dutch population-based sample of sporadic CJD (sCJD) patients and a cognitively normal control group of similar age distribution. We genotyped the same polymorphisms in two other sample groups of sCJD cases from Italy and the UK. In addition, we compared MAPT haplotypes between sCJD and variant CJD (vCJD) patients.

    Results: Single locus and haplotype analyses did not detect any significant difference between sCJD cases and controls. When we compared MAPT haplotypes between sCJD and variant CJD (vCJD) patients, we found that two of them were represented differently (H1f: 8% in sCJD versus 2% in vCJD; H1j:1% in sCJD versus 7% in vCJD). However, these two haplotypes were rare in both groups of patients, and taking the small sample sizes into account, we cannot exclude that the differences are due to chance. None of the p-values remained statistically significant after applying a multiple testing correction.

    Conclusion: Our study shows no evidence for an association between MAPT gene variations and sCJD, and some weak evidence for an association to vCJD.

    BMC medical genetics 2007;8;77

  • Site-specific effects of tau phosphorylation on its microtubule assembly activity and self-aggregation.

    Liu F, Li B, Tung EJ, Grundke-Iqbal I, Iqbal K and Gong CX

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.

    Microtubule-associated protein tau is abnormally hyperphosphorylated and aggregated into neurofibrillary tangles in brains with Alzheimer's disease. The phosphorylation sites of tau are mainly localized in the proline-rich (residues 172-251) and C-terminal tail (residues 368-441) regions, which flank the microtubule-binding repeats. Here, we investigated the effects of tau phosphorylation at these distinct sites/regions on its activity of stimulating microtubule assembly and its self-aggregation. We found that tau phosphorylation at the proline-rich region by dual-specificity tyrosine-phosphorylated and -regulated kinase 1A inhibited its microtubule assembly activity moderately and promoted its self-aggregation slightly. Tau phosphorylation at the C-terminal tail region by glycogen synthase kinase-3beta increased its activity and promoted its self-aggregation markedly. Tau phosphorylation at both regions plus the microtubule-binding region by cAMP-dependent protein kinase diminished its activity (approximately 70% inhibition) and disrupted microtubules. These studies reveal the differential regulation of tau's biological activity and self-aggregation by phosphorylation at various sites/regions.

    Funded by: NIA NIH HHS: AG 019158, AG 027429, R01 AG019158, R01 AG027429, R01 AG027429-01, R01 AG027429-02

    The European journal of neuroscience 2007;26;12;3429-36

  • Split GFP complementation assay: a novel approach to quantitatively measure aggregation of tau in situ: effects of GSK3beta activation and caspase 3 cleavage.

    Chun W, Waldo GS and Johnson GV

    Department of Psychiatry, University of Alabama at Birmingham School of Medicine, Alabama, USA.

    To quantitatively measure tau aggregation in situ, we established a cell model system using a split green fluorescence protein (GFP) complementation assay. In this assay the more aggregated the protein of interest the lower the GFP fluorescence. Tau microtubule-binding domain constructs, whose aggregation characteristics have been described previously (Khlistunova et al. 2006), were used to validate the assay. The aggregation-prone construct exhibited the lowest GFP intensity whereas the aggregation-resistant construct showed the highest GFP intensity. To examine the role of glycogen synthase kinase 3beta (GSK3beta) activity and caspase 3 cleavage on tau aggregation, GFP complementation of full length (T4), caspase-cleaved (T4C3), and pseudophosphorylated at S396/S404 (T4-2EC) tau was examined in the presence of an active or a kinase-dead GSK3beta. Extensive phosphorylation of T4 by GSK3beta resulted in increased GFP intensity. T4C3 showed neither efficient phosphorylation nor a significant GFP intensity change by GSK3beta. The GFP intensity of T4-2EC was significantly reduced by GSK3beta accompanying its presence in the sarkosyl-insoluble fraction, thus demonstrating that T4-2EC was partitioning into aggregates. This indicates that if the majority of tau is phosphorylated at S396/S404, in combination with increased GSK3beta activity, tau aggregation is favored. These data demonstrate that split GFP complementation may be a valuable approach to determine the aggregation process in living cells.

    Funded by: NINDS NIH HHS: NS051279

    Journal of neurochemistry 2007;103;6;2529-39

  • Increase in the relative expression of tau with four microtubule binding repeat regions in frontotemporal lobar degeneration and progressive supranuclear palsy brains.

    Ingelsson M, Ramasamy K, Russ C, Freeman SH, Orne J, Raju S, Matsui T, Growdon JH, Frosch MP, Ghetti B, Brown RH, Irizarry MC and Hyman BT

    Harvard Medical School, Massachusetts General Hospital, 114 16th Street, Charlestown, MA 02129, USA. martin.ingelsson@pubcare.uu.se

    Some cases of familial frontotemporal dementia (FTD) leading to frontotemporal lobar degeneration (FTLD) are caused by mutations in tau on chromosome 17 (FTDP-17). Certain mutations alter the ratio between four (4R tau) and three (3R tau) repeat tau isoforms whereas cases with progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) mainly have 4R tau brain pathology. We assessed tau mRNA and protein levels in frontal cortex from 15 sporadic FTLD, 21 PSP, 5 CBD, 15 Alzheimer's disease (AD) and 16 control brains. Moreover, we investigated the disease association and possible tau splicing effects of the tau H1 haplotype. Cases with FTLD and PSP had lower tau mRNA levels than control brains. When analyzing 4R tau and 3R tau mRNA separately, control subjects displayed a 4R tau/3R tau ratio of 0.48. Surprisingly, FTLD brains displayed a more elevated ratio (1.32) than PSP brains (1.12). Also, several FTLD and PSP cases had higher 4R tau/3R tau mRNA than FTDP-17 cases, included as reference tissues, and the ratio increase was seen regardless of underlying histopathology, i.e. both for tau-positive and tau-negative FTLD cases. Furthermore, total tau protein levels were slightly decreased in both FTLD and AD as compared to control subjects. Finally, we confirmed the association of tau H1 with PSP, but could not find any haplotype-related effect on tau exon 10 splicing. In conclusion, we demonstrated increased but largely variable 4R tau/3R tau mRNA ratios in FTLD and PSP cases, suggesting heterogeneous pathophysiological processes within these disorders.

    Funded by: NIA NIH HHS: AG08487, P30 AG10133, P50 AG05134; NIMH NIH HHS: R24-MH 068855

    Acta neuropathologica 2007;114;5;471-9

  • Reduced insulin-induced phosphatidylinositol-3-kinase activation in peripheral blood mononuclear leucocytes from patients with Alzheimer's disease.

    Castri P, Iacovelli L, De Blasi A, Giubilei F, Moretti A, Tari Capone F, Nicoletti F and Orzi F

    Department of Neurological Sciences, II Faculty of Medicine, University of Rome 'La Sapienza', Italy. paola.castri@uniroma1.it

    The epidemiological finding of an increased risk of dementia in patients with diabetes mellitus has raised the hypothesis that a dysfunction of the insulin receptors plays a role in the pathogenesis of Alzheimer's disease (AD). A possible link is suggested by the evidence that the insulin-stimulated phosphatidylinositol-3-kinase (PI-3-K)/phospho-Akt pathway negatively controls the glycogen synthase kinase-3beta. The activation of this enzyme mediates the hyperphosphorylation of the tau protein, a relevant step in the formation of the neurofibrillary tangles associated with AD. We hypothesized that the neurodegeneration associated with AD is related to an impairment of the intracellular signalling stimulated by insulin receptors. To test this hypothesis we assessed the PI-3-K/phospho-Akt pathway following in-vitro challenge with insulin in peripheral blood mononuclear cells from subjects with AD (n = 20) and controls (n = 20). We found that the stimulation of PI-3-K is blunted in patients with AD with respect to control. The reduction did not correlate with the extent of cognitive decline or with scores at neuropsychological tests exploring attention, memory, language or visuospatial abilities. The study supports the hypothesis that an impaired control of glycogen synthase kinase-3beta activity by insulin receptor-mediated signalling plays a role in the pathogenesis of AD, facilitating tau protein phosphorylation and neurofibrillary tangle formation.

    The European journal of neuroscience 2007;26;9;2469-72

  • Role of ethnicity on the association of MAPT H1 haplotypes and subhaplotypes in Parkinson's disease.

    Winkler S, König IR, Lohmann-Hedrich K, Vieregge P, Kostic V and Klein C

    Department of Neurology, University of Lübeck, Lübeck, Germany.

    An association of the H1 haplotype and subhaplotypes in the microtubule-associated protein Tau (MAPT) gene with Parkinson's disease (PD) has been reported. To further evaluate their role in PD, we genotyped a sample set of 765 cases and controls consisting of two large European subgroups of German (n=418) and Serbian (n=347) origin for the MAPT haplotypes H1 and H2. The H1/H1 carriers were tested for three additional MAPT polymorphisms. In the Serbian sample, there was significant evidence (P=0.0108) of an association of the H1/H1 genotype and PD. Surprisingly, in the German sample, we did not find significant differences in genotype or haplotype frequencies between patients and controls. These results suggest that the role of H1 haplotypes in the etiology of PD may be ethnically dependent.

    European journal of human genetics : EJHG 2007;15;11;1163-8

  • Single molecule profiling of tau gene expression in Alzheimer's disease.

    Conrad C, Zhu J, Conrad C, Schoenfeld D, Fang Z, Ingelsson M, Stamm S, Church G and Hyman BT

    Department of Neurology, MassGeneral Institute for Neurodegenerative Disease (MIND), Charlestown, Massachusetts, USA. cgc2105@columbia.edu

    Tau is a microtubule-associated protein that is important for establishing and maintaining neuronal morphology. In addition to its role in normal cells, tau protein is involved in many neurodegenerative diseases, e.g. Alzheimer's disease (AD) and frontotemporal dementia, as the main component of intraneuronal aggregates. Alternative splicing of tau gene in the brain can give rise to at least six protein variants. A causative role of skewed tau exon 10 inclusion has been defined in frontotemporal dementia; however, no link was established between the aberrant splicing of tau and AD. Here, we applied a single-molecule-based technology, polymerase colony or polony, to simultaneously monitor tau splicing variant and haplotype profile in sporadic AD and normal brains. We found that the coordinated expression of tau exons 2 and 10 is altered in AD. Additional investigations of cis and trans mechanisms of this observation revealed a decreased protein expression of a known tau splicing factor, htra2-beta-1 in AD, thereby implicating a trans mechanism. Our results demonstrate that dysregulation of combinatorial splicing might serve as a signature for aging-related diseases, and the polony assay could be widely adapted for the study of other tauopathies. Furthermore, splicing-based therapeutics is an emerging area of drug development, and a well-defined and quantitative assay for monitoring single-gene transcriptome will be relevant for such development.

    Funded by: NIA NIH HHS: P50AG005134

    Journal of neurochemistry 2007;103;3;1228-36

  • Interaction of tau protein with the dynactin complex.

    Magnani E, Fan J, Gasparini L, Golding M, Williams M, Schiavo G, Goedert M, Amos LA and Spillantini MG

    Department of Clinical Neurosciences, Brain Repair Centre, University of Cambridge, Cambridge, UK.

    Tau is an axonal microtubule-associated protein involved in microtubule assembly and stabilization. Mutations in Tau cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and tau aggregates are present in Alzheimer's disease and other tauopathies. The mechanisms leading from tau dysfunction to neurodegeneration are still debated. The dynein-activator complex dynactin has an essential role in axonal transport and mutations in its gene are associated with lower motor neuron disease. We show here for the first time that the N-terminal projection domain of tau binds to the C-terminus of the p150 subunit of the dynactin complex. Tau and dynactin show extensive colocalization, and the attachment of the dynactin complex to microtubules is enhanced by tau. Mutations of a conserved arginine residue in the N-terminus of tau, found in patients with FTDP-17, affect its binding to dynactin, which is abnormally distributed in the retinal ganglion cell axons of transgenic mice expressing human tau with a mutation in the microtubule-binding domain. These findings, which suggest a direct involvement of tau in axonal transport, have implications for understanding the pathogenesis of tauopathies.

    Funded by: Medical Research Council: G0301152, MC_U105184291, MC_U105184313, U.1051.04.002(78842)

    The EMBO journal 2007;26;21;4546-54

  • Pharmacogenetic assessment of toxicity and outcome after platinum plus taxane chemotherapy in ovarian cancer: the Scottish Randomised Trial in Ovarian Cancer.

    Marsh S, Paul J, King CR, Gifford G, McLeod HL and Brown R

    Washington University School of Medicine, Division of Oncology, St Louis, MO 63110, USA. smarsh@im.wustl.edu

    Purpose: Standard therapy for advanced ovarian cancer consists of a platinum agent in combination with a taxane, which has a 5-year survival rate of approximately 45%. The large individual variability for ovarian cancer patients in both outcome and toxicity risk from chemotherapy makes the identification of pharmacogenetic markers that can be used to screen patients before therapy selection an attractive prospect.

    We assessed 27 selected polymorphisms based on previously described associations or putative functional effects in 16 key genes from pathways that may influence cellular sensitivity to taxanes (ABCB1, ABCC1, ABCC2, ABCG2, CDKN1A, CYP1B1, CYP2C8, CYP3A4, CYP3A5, MAPT, and TP53) and platinum (ABCC2, ABCG2, ERCC1, ERCC2, GSTP1, MPO, and XRCC1) using polymerase chain reaction and Pyrosequencing in 914 ovarian cancer patients from the Scottish Randomised Trial in Ovarian Cancer phase III trial who were treated at presentation with carboplatin and taxane regimens after cytoreductive surgery.

    Results: No reproducible significant associations between genotype and outcome or toxicity were found for any of the genes analyzed. Previously reported genotype associations could not be replicated in this large study of a well-defined patient population within one specific clinical trial.

    Conclusion: There are no clear candidates for taxane/platinum pharmacogenetic markers. This study highlights the need for validation of putative genetic markers in large, well-defined clinical sample sets.

    Funded by: NCI NIH HHS: R21 CA113491; NIGMS NIH HHS: U01 GM63340

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2007;25;29;4528-35

  • Association of the tau haplotype H2 with age at onset and functional alterations of glucose utilization in frontotemporal dementia.

    Laws SM, Perneczky R, Drzezga A, Diehl-Schmid J, Ibach B, Bäuml J, Eisele T, Förstl H, Kurz A and Riemenschneider M

    Neurochemistry and Neurogenetics Laboratory, Department of Psychiatry and Psychotherapy, Munich University of Technology, 81675 Munich, Germany.

    Objective: The microtubule-associated protein tau gene (MAPT) contains two extended haplotypes, H1 and H2, which have been linked with sporadic tauopathies. However, there is little evidence as to how these haplotypes may influence the clinical features of the disease. The aim of this study was to investigate the MAPT haplotypes in relation to risk for, and functional alterations of glucose metabolism in, patients with frontotemporal dementia (FTD).

    Method: The authors investigated MAPT haplotypes in 142 individuals with FTD and 292 comparison subjects. Additionally, in a subset of 41 individuals with FTD and 16 comparison subjects, the authors undertook functional [ (18)F]fluorodeoxyglucose positron emission tomography (PET) imaging.

    Results: MAPT haplotype distribution did not differ significantly between individuals with FTD and comparison subjects. However, the H2 haplotype was clinically associated with an earlier age at onset of FTD, which presented in a dose-dependent manner. Correspondingly, PET analysis revealed functional differences in glucose utilization patterns between MAPT haplotypes, with H2 carriers having a more pronounced hypometabolism in frontal brain areas than H1 carriers, which could not be accounted for by differences in duration of illness.

    Conclusions: While the extended MAPT H1 and H2 haplotypes do not appear to confer risk for disease development, the H2 haplotype appears to modify age at onset and functionally shows a more severe decline of glucose utilization in frontal brain areas.

    The American journal of psychiatry 2007;164;10;1577-84

  • Phenotypic variability associated with progranulin haploinsufficiency in patients with the common 1477C-->T (Arg493X) mutation: an international initiative.

    Rademakers R, Baker M, Gass J, Adamson J, Huey ED, Momeni P, Spina S, Coppola G, Karydas AM, Stewart H, Johnson N, Hsiung GY, Kelley B, Kuntz K, Steinbart E, Wood EM, Yu CE, Josephs K, Sorenson E, Womack KB, Weintraub S, Pickering-Brown SM, Schofield PR, Brooks WS, Van Deerlin VM, Snowden J, Clark CM, Kertesz A, Boylan K, Ghetti B, Neary D, Schellenberg GD, Beach TG, Mesulam M, Mann D, Grafman J, Mackenzie IR, Feldman H, Bird T, Petersen R, Knopman D, Boeve B, Geschwind DH, Miller B, Wszolek Z, Lippa C, Bigio EH, Dickson D, Graff-Radford N and Hutton M

    Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA. rademakers.rosa@mayo.edu

    Background: The progranulin gene (GRN) is mutated in 5-10% of patients with frontotemporal lobar degeneration (FTLD) and in about 20% of patients with familial FTLD. The most common mutation in GRN is Arg493X. We aimed to establish the contribution of this mutation to FTLD and related disorders.

    Methods: We measured the frequency of Arg493X in 3405 unrelated patients with various neurodegenerative diseases using Taqman single-nucleotide polymorphism (SNP) genotyping. Clinicopathological characterisation and shared haplotype analysis were done for 30 families with FTLD who carry Arg493X. To investigate the effect of potential modifying loci, we did linear regression analyses with onset age as the covariate for GRN variants, for genotypes of the apolipoprotein E gene (APOE), and for haplotypes of the microtubule-associated protein tau gene (MAPT).

    Findings: Of 731 patients with FTLD, 16 (2%) carried Arg493X. This mutation was not detected in 2674 patients who did not have FTLD. In 37 patients with Arg493X from 30 families with FTLD, clinical diagnoses included frontotemporal dementia, primary progressive aphasia, corticobasal syndrome, and Alzheimer's disease. Range of onset age was 44-69 years. In all patients who came to autopsy (n=13), the pathological diagnosis was FTLD with neuronal inclusions that contained TAR DNA-binding protein or ubiquitin, but not tau. Neurofibrillary tangle pathology in the form of Braak staging correlated with overall neuropathology in the Arg493X carriers. Haplotype analyses suggested that Arg493X arose twice, with a single founder for 27 families. Linear regression analyses suggested that patients with SNP rs9897528 on their wild-type GRN allele have delayed symptom onset. Onset ages were not associated with the MAPT H1 or H2 haplotypes or APOE genotypes, but early memory deficits were associated with the presence of an APOE epsilon4 allele.

    Interpretation: Clinical heterogeneity is associated with GRN haploinsufficiency, and genetic variability on the wild-type GRN allele might have a role in the age-related disease penetrance of GRN mutations.

    Funded by: Intramural NIH HHS; Medical Research Council: G0400356; NIA NIH HHS: P01 AG017216, P01 AG019724, P01 AG17586, P30 AG10133, P30 AG12300, P30 AG13854, P30 AG19610, P50 AG03006, P50 AG05136, P50 AG16574, R01 AG026251, R01 AG026938; NINDS NIH HHS: P50 NS40256

    The Lancet. Neurology 2007;6;10;857-68

  • Levels of ApoE in cerebrospinal fluid are correlated with Tau and 24S-hydroxycholesterol in patients with cognitive disorders.

    Shafaati M, Solomon A, Kivipelto M, Björkhem I and Leoni V

    Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.

    Evidence was recently presented from in vitro studies that 24S-hydroxycholesterol acts as a signalling molecule inducing apoE-mediated cholesterol efflux from astrocytoma cells, and that there is a direct effect of the oxysterol on apoE transcription, protein synthesis and secretion. Consistent with this mechanism, a significant correlation is demonstrated here between levels of apoE and 24S-hydroxycholesterol in cerebrospinal fluid from patients with Alzheimer's disease and patients with mild cognitive impairment. Such a correlation was not found in control patients. There was no correlation between levels of apoE and cholesterol in cerebrospinal fluid from controls. The results are consistent with a close coupling between release of 24S-hydroxycholesterol and apoE secretion under conditions with neuronal degeneration. The levels of apoE in cerebrospinal fluid were also correlated to the levels of Tau and the possibility is discussed that the level of apoE in cerebrospinal fluid may be used as a marker of neurodegeneration.

    Neuroscience letters 2007;425;2;78-82

  • Phenylthiazolyl-hydrazide and its derivatives are potent inhibitors of tau aggregation and toxicity in vitro and in cells.

    Pickhardt M, Larbig G, Khlistunova I, Coksezen A, Meyer B, Mandelkow EM, Schmidt B and Mandelkow E

    Max-Planck-Unit for Structural Molecular Biology, c/o DESY, Notkestrasse 85, D-22607 Hamburg, Germany.

    One of the key pathological features of Alzheimer's disease is the aggregation of tau protein. We are therefore searching for compounds capable of inhibiting this reaction. On the basis of an initial screen of 200000 compounds [Pickhardt, M., Gazova, Z., von Bergen, M., Khlistunova, I., Wang, Y., Hascher, A., Mandelkow, E. M., Biernat, J., and Mandelkow, E. (2005) Anthraquinones inhibit tau aggregation and dissolve Alzheimer's paired helical filaments in vitro and in cells, J. Biol. Chem. 280, 3628-3635], we performed an in silico screen and predicted a new phenylthiazolyl-hydrazide (PTH) compound as a possible hit [Larbig, G., Pickhardt, M., Lloyd, D. G., Schmidt, B., and Mandelkow, E. (2007) Screening for inhibitors of tau protein aggregation into Alzheimer paired helical filaments: A ligand based approach results in successful scaffold hopping. Curr. Alzheimer Res. 4 (3), 315-323.]. Synthesis of this compound showed that it was indeed active in terms of inhibiting de novo tau aggregation and disassembling preformed aggregates (IC50 = 7.7 microM and DC50 = 10.8 microM). We have now synthesized 49 similar structures and identified the core of the PTHs to be crucial for activity, thus representing a lead structure. Analysis of the binding epitope by saturation transfer difference NMR shows strong interactions between the tau protein and the ligand in the aromatic regions of the inhibitor. By chemical variation of the core, we improved the inhibitory potency five-fold. The compounds showed a low toxicity as judged by an N2A cell model of tau aggregation and lend themselves for further development.

    Biochemistry 2007;46;35;10016-23

  • MAPT gene duplications are not a cause of frontotemporal lobar degeneration.

    Lladó A, Rodríguez-Santiago B, Antonell A, Sánchez-Valle R, Molinuevo JL, Reñé R and Pérez-Jurado LA

    Alzheimer's Disease and other Cognitive Disorders Unit, Neurology Service, Hospital Clínic and the August Pi i Sunyer Institute of Biomedical Research (IDIBAPS), Barcelona, Spain.

    Recurrent deletions of the 17q21.31 region encompassing the microtubule-associated protein tau (MAPT) gene have recently been described in patients with mental retardation. This region is flanked by segmental duplications that make it prone to inversions, deletions and duplications. Since gain-of-function mutations of the MAPT gene cause frontotemporal lobar degeneration (FTLD) characterized by deposition of tau protein, we hypothesize that MAPT duplication affecting gene dosage could also lead to disease. Gene dosage alterations have already been found to be involved in the etiology of neurodegenerative disorders caused by protein or peptide accumulation, such as Alzheimer's and Parkinson's diseases. To determine whether MAPT gene copy number variation is involved in FTLD, 70 patients with clinical diagnosis of FTLD and no MAPT mutation (including 12 patients with pathologically proven tau-positive FTLD) were screened by using multiplex ligation probe amplification (MLPA) with specific oligonucleotide probes. No copy number variation in the MAPT gene was observed in cases. Although our study was limited by the relatively small number of patients, it does not support the theory that chromosomal rearrangements in this region are a cause of FTLD.

    Neuroscience letters 2007;424;1;61-5

  • Activation of glycogen synthase kinase 3beta promotes the intermolecular association of tau. The use of fluorescence resonance energy transfer microscopy.

    Chun W and Johnson GV

    Department of Psychiatry, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama 35294, USA.

    Tau is hyperphosphorylated and undergoes proteolysis in Alzheimer disease brain. Caspase-cleaved tau efficiently forms fibrillary structures in vitro and in situ. Glycogen synthase kinase 3beta (GSK3beta) phosphorylates tau and induces the aggregation of caspase-cleaved tau in situ. Given the hypothesis that increased association of tau precedes the formation of fibrillar structures, we generated a cell model to quantitate the extent of tau association in situ using fluorescence resonance energy transfer (FRET) microscopy. The cyan and yellow fluorescent proteins were attached to full-length (T4) and caspase-cleaved (T4C3) tau at either the N or C termini, and a pair of cyan and yellow fluorescent protein-tagged tau were co-transfected into human embryonic kidney cells. The FRET efficiency was examined in the presence of a constitutively active or a kinase-dead GSK3beta. Active GSK3beta significantly increased FRET efficiency with both T4 and T4C3, indicating that GSK3beta activation resulted in an increase in the self-association of both T4 and T4C3, but interestingly only T4 is efficiently phosphorylated by GSK3beta. There was no significant difference in FRET efficiency between T4 and T4C3, although only T4C3 in the presence of active GSK3beta leads to the formation of Sarkosyl-insoluble inclusions. These FRET studies demonstrate that GSK3beta facilitates the association of T4 and T4C3, and the presence of caspase-cleaved tau is necessary for the evolution of tau oligomers into Sarkosyl-insoluble inclusions even though it is not extensively phosphorylated. These data imply that increased association of tau should not be regarded as a direct indicator of the formation of insoluble tau aggregates.

    Funded by: NINDS NIH HHS: NS051279

    The Journal of biological chemistry 2007;282;32;23410-7

  • Novel phosphorylation sites in tau from Alzheimer brain support a role for casein kinase 1 in disease pathogenesis.

    Hanger DP, Byers HL, Wray S, Leung KY, Saxton MJ, Seereeram A, Reynolds CH, Ward MA and Anderton BH

    MRC Centre for Neurodegeneration Research, Department of Neuroscience, King's College London, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, United Kingdom.

    Tau in Alzheimer disease brain is highly phosphorylated and aggregated into paired helical filaments comprising characteristic neurofibrillary tangles. Here we have analyzed insoluble Tau (PHF-tau) extracted from Alzheimer brain by mass spectrometry and identified 11 novel phosphorylation sites, 10 of which were assigned unambiguously to specific amino acid residues. This brings the number of directly identified sites in PHF-tau to 39, with an additional six sites indicated by reactivity with phosphospecific antibodies to Tau. We also identified five new phosphorylation sites in soluble Tau from control adult human brain, bringing the total number of reported sites to nine. To assess which kinases might be responsible for Tau phosphorylation, we used mass spectrometry to determine which sites were phosphorylated in vitro by several kinases. Casein kinase 1delta and glycogen synthase kinase-3beta were each found to phosphorylate numerous sites, and each kinase phosphorylated at least 15 sites that are also phosphorylated in PHF-tau from Alzheimer brain. A combination of casein kinase 1delta and glycogen synthase kinase-3beta activities could account for over three-quarters of the serine/threonine phosphorylation sites identified in PHF-tau, indicating that casein kinase 1delta may have a role, together with glycogen synthase kinase-3beta, in the pathogenesis of Alzheimer disease.

    Funded by: Medical Research Council: G0300408

    The Journal of biological chemistry 2007;282;32;23645-54

  • A novel MAPT mutation (P301T) associated with familial frontotemporal dementia.

    Lladó A, Ezquerra M, Sánchez-Valle R, Rami L, Tolosa E and Molinuevo JL

    European journal of neurology : the official journal of the European Federation of Neurological Societies 2007;14;8;e9-10

  • Association analysis of MAPT H1 haplotype and subhaplotypes in Parkinson's disease.

    Zabetian CP, Hutter CM, Factor SA, Nutt JG, Higgins DS, Griffith A, Roberts JW, Leis BC, Kay DM, Yearout D, Montimurro JS, Edwards KL, Samii A and Payami H

    Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA. zabetian@u.washington.edu

    Objective: An inversion polymorphism of approximately 900 kb on chromosome 17q21, which includes the microtubule-associated protein tau (MAPT) gene defines two haplotype clades, H1 and H2. Several small case-control studies have observed a marginally significant excess of the H1/H1 diplotype among patients with Parkinson's disease (PD), and one reported refining the association to a region spanning exons 1 to 4 of MAPT. We sought to replicate these findings.

    Methods: We genotyped 1,762 PD patients and 2,010 control subjects for a single nucleotide polymorphism (SNP) that differentiates the H1 and H2 clades. We also analyzed four SNPs that define subhaplotypes within H1 previously reported to associate with PD or other neurodegenerative disorders.

    Results: After adjusting for age, sex, and site, we observed a robust association between the H1/H1 diplotype and PD risk (odds ratio for H1/H1 vs H1/H2 and H2/H2, 1.46; 95% confidence interval, 1.25-1.69; p = 8 x 10(-7)). The effect was evident in both familial and sporadic subgroups, men and women, and early- and late-onset disease. Within H1/H1 individuals, there was no significant difference between cases and control subjects in the overall frequency distribution of H1 subhaplotypes.

    Interpretation: Our data provide strong evidence that the H1 clade, which contains MAPT and several other genes, is a risk factor for PD. However, attributing this finding to variants within a specific region of MAPT is premature. Thorough fine-mapping of the H1 clade in large numbers of individuals is now needed to identify the underlying functional variant(s) that alter susceptibility for PD.

    Funded by: NIA NIH HHS: N1A P30 AG008017; NINDS NIH HHS: K08 NS044138, K08 NS044138-04, R01 NS036960

    Annals of neurology 2007;62;2;137-44

  • Tau and alpha-synuclein in susceptibility to, and dementia in, Parkinson's disease.

    Goris A, Williams-Gray CH, Clark GR, Foltynie T, Lewis SJ, Brown J, Ban M, Spillantini MG, Compston A, Burn DJ, Chinnery PF, Barker RA and Sawcer SJ

    Department of Clinical Neurosciences (Neurology Unit), University of Cambridge, Cambridge, United Kingdom. an.goris@med.kuleuven.be

    Objective: Parkinson's disease (PD) is a neurodegenerative condition that typically presents as a movement disorder but is known to be associated with variable degrees of cognitive impairment including dementia. We investigated the genetic basis of susceptibility to and cognitive heterogeneity of this disease.

    Methods: In 659 PD patients, 109 of which were followed up for 3.5 years from diagnosis, and 2,176 control subjects, we studied candidate genes involved in protein aggregation and inclusion body formation, the pathological hallmark of parkinsonism: microtubule-associated protein tau (MAPT), glycogen synthase kinase-3beta (GSK3B), and alpha-synuclein (SNCA).

    Results: We observed that cognitive decline and the development of PD dementia are strongly associated (p = 10(-4)) with the inversion polymorphism containing MAPT. We also found a novel synergistic interaction between the MAPT inversion polymorphism and the single nucleotide polymorphism rs356219 from the 3' region of SNCA. In our data, carrying a risk genotype at either of these loci marginally increases the risk for development of PD, whereas carrying the combination of risk genotypes at both loci approximately doubles the risk for development of the disease (p = 3 x 10(-6)).

    Interpretation: Our data support the hypothesis that tau and alpha-synuclein are involved in shared or converging pathways in the pathogenesis of PD, and suggest that the tau inversion influences the development of cognitive impairment and dementia in patients with idiopathic PD. These findings have potentially important implications for understanding the interface between tau and alpha-synuclein pathways in neurodegenerative disorders and for unraveling the biological basis for cognitive impairment and dementia in PD.

    Funded by: Parkinson's UK: G-4054

    Annals of neurology 2007;62;2;145-53

  • A complex mechanism for inducer mediated tau polymerization.

    Carlson SW, Branden M, Voss K, Sun Q, Rankin CA and Gamblin TC

    Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA.

    The accumulation of polymers of the microtubule associated protein tau is correlative with increased neurodegeneration in Alzheimer's disease and other related tauopathies. In vitro models have been developed in order to investigate molecular mechanisms that regulate the polymerization of tau. Arachidonic acid and heparin have been proposed to induce tau polymerization via a ligand dependent nucleation-elongation mechanism. However, certain aspects of these in vitro results are inconsistent with a classic nucleation-elongation mechanism. Using steady state and kinetic analyses of tau polymerization at a variety of protein and inducer concentrations, we have found that the thermodynamic barrier for nucleation in the presence of inducers is negligible, which was manifested by increases in protein polymerization at low tau concentrations and very rapid kinetics of polymerization. However, the mechanism of polymerization is complicated by the observation that high concentrations of inducer molecules result in the inhibition of tau fibril formation through different mechanisms for arachidonic acid and heparin. These observations indicate that the molar ratio of inducer to protein is a greater determinant of the rate and extent of tau polymerization than the concentration of tau itself. Our results are therefore not consistent with a canonical nucleation-elongation reaction but rather are more consistent with an allosteric regulation model in which the presence of small molecules induce a conformational change in the protein that decreases the thermodynamic barrier for polymerization essentially to zero.

    Funded by: NIA NIH HHS: AG022428

    Biochemistry 2007;46;30;8838-49

  • Impairments in impulse control in mice transgenic for the human FTDP-17 tauV337M mutation are exacerbated by age.

    Lambourne SL, Humby T, Isles AR, Emson PC, Spillantini MG and Wilkinson LS

    Laboratory of Cognitive and Behavioural Neuroscience, The Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK.

    Abnormalities in microtubule-associated tau protein are a key neuropathological feature of both Alzheimer's disease and many frontotemporal dementias (FTDs), including hereditary FTD with Parkinsonism linked to chromosome 17 (FTDP-17). In these disorders, tau becomes aberrantly phosphorylated, leading to the development of filamentous neurofibrillary tangles in the brain. Here we report, in a longitudinal ageing study, the sensorimotor and cognitive assessment of transgenic mice expressing the human tau(V337M) ('Seattle Family A') FTDP-17 mutation, which we have previously shown to demonstrate abnormalities in brain tau phosphorylation. The data indicated highly specific effects of transgene expression on the ability to withhold responding in a murine version of the 5-choice serial reaction time task, behaviour consistent with deficits in impulse control. Ageing exacerbated these effects. In young tau(V337M) mice, increased impulsivity was present under task conditions making inhibition of premature responding more difficult (longer inter-trial intervals) but not under baseline conditions. However, when older, the tau(V337M) mice showed further increases in premature responding, including under baseline conditions. These impulse control deficits were fully dissociable from sensorimotor or motivation effects on performance. The findings recapitulate core abnormalities in impulsive responding observed in both frontal variant FTD and FTDP-17 linked to the tau(V337M) mutation in humans.

    Human molecular genetics 2007;16;14;1708-19

  • Clinical and genetic features of families with frontotemporal dementia and parkinsonism linked to chromosome 17 with a P301S tau mutation.

    Baba Y, Baker MC, Le Ber I, Brice A, Maeck L, Kohlhase J, Yasuda M, Stoppe G, Bugiani O, Sperfeld AD, Tsuboi Y, Uitti RJ, Farrer MJ, Ghetti B, Hutton ML and Wszolek ZK

    Department of Neurology, Mayo Clinic, Jacksonville, Florida 32224, USA.

    In 9 patients with frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) with a P301S tau mutation, the predominant phenotype was frontotemporal dementia in 3 and parkinsonism in 6. Comparison of the tau genotype/haplotype carrying the mutation and the initial clinical sign showed association between H1/H1 and parkinsonism and between H1/H2 and personality change. Thus, the tau haplotype carrying the mutation and the tau genotype may be related to the clinical phenotype throughout the disease course.

    Journal of neural transmission (Vienna, Austria : 1996) 2007;114;7;947-50

  • Functional MAPT haplotypes: bridging the gap between genotype and neuropathology.

    Caffrey TM and Wade-Martins R

    The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.

    The microtubule-associated protein tau (MAPT) locus has long been associated with sporadic neurodegenerative disease, notably progressive supranuclear palsy and corticobasal degeneration, and more recently with Alzheimer's disease and Parkinson's disease. However, the functional biological mechanisms behind the genetic association have only now started to emerge. The genomic architecture in the region spanning MAPT is highly complex, and includes a approximately 1.8 Mb block of linkage disequilibrium (LD). The region is divided into two major haplotypes, H1 and H2, defined by numerous single nucleotide polymorphisms and a 900 kb inversion which suppresses recombination. Fine mapping of the MAPT region has identified sub-clades of the MAPT H1 haplotype which are specifically associated with neurodegenerative disease. Here we briefly review the role of MAPT in sporadic and familial neurodegenerative disease, and then discuss recent work which, for the first time, proposes functional mechanisms to link MAPT haplotypes with the neuropathology seen in patients.

    Funded by: Wellcome Trust: 073141

    Neurobiology of disease 2007;27;1;1-10

  • Tau-4R suppresses proliferation and promotes neuronal differentiation in the hippocampus of tau knockin/knockout mice.

    Sennvik K, Boekhoorn K, Lasrado R, Terwel D, Verhaeghe S, Korr H, Schmitz C, Tomiyama T, Mori H, Krugers H, Joels M, Ramakers GJ, Lucassen PJ and Van Leuven F

    Experimental Genetics Group, Department Human Genetics, KULeuven-Campus Gasthuisberg ON1-06.602, B-3000 Leuven, Belgium.

    Differential isoform expression and phosphorylation of protein tau are believed to regulate the assembly and stabilization of microtubuli in fetal and adult neurons. To define the functions of tau in the developing and adult brain, we generated transgenic mice expressing the human tau-4R/2N (htau-4R) isoform on a murine tau null background, by a knockout/knockin approach (tau-KOKI). The main findings in these mice were the significant increases in hippocampal volume and neuronal number, which were sustained throughout adult life and paralleled by improved cognitive functioning. The increase in hippocampal size was found to be due to increased neurogenesis and neuronal survival. Proliferation and neuronal differentiation were further analyzed in primary hippocampal cultures from tau-KOKI mice, before and after htau-4R expression onset. In absence of tau, proliferation increased and both neurite and axonal outgrowth were reduced. Htau-4R expression suppressed proliferation, promoted neuronal differentiation, and restored neurite and axonal outgrowth. We suggest that the tau-4R isoform essentially contributes to hippocampal development by controlling proliferation and differentiation of neuronal precursors.

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2007;21;9;2149-61

  • Epitope mapping of mAbs AT8 and Tau5 directed against hyperphosphorylated regions of the human tau protein.

    Porzig R, Singer D and Hoffmann R

    Institute of Bioanalytical Chemistry, Center for Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Deutscher Platz 5, Leipzig, Germany.

    Post-mortem diagnosis of Alzheimer's disease relies on high numbers of senile plaques and neurofibrillary tangles (NFTs) stained in distinct brain areas. NFTs mostly consist of hyperphosphorylated versions of the microtubule attached tau protein (PHF-tau) with more than 30 serine and threonine phosphorylation sites identified so far. Characterization of hyperphosphorylated tau regions and the hope to develop robust assays for early AD diagnosis relies mostly on phosphorylation-dependent monoclonal antibodies (mAbs) recognizing only disease-specific phosphorylation patterns. Here, we report that anti-PHF-tau mAb AT8 recognizes an epitope doubly phosphorylated at serine 202 and threonine 205, which was not influenced by a third phosphate group at serine 199. But mAb AT8 was cross-reactive to two doubly phosphorylated motifs containing either serines 199 and 202 or serines 205 and 208 of the human tau sequence. The epitope of anti-tau mAb Tau5 was mapped to the human tau sequence 218-225, which is not phosphorylated in vivo.

    Biochemical and biophysical research communications 2007;358;2;644-9

  • A mouse model to study tau pathology related with tau phosphorylation and assembly.

    Engel T, Lucas JJ, Hernández F and Avila J

    Centro de Biología Molecular "Severo Ochoa", CSIC/UAM, 28049 Madrid, Spain.

    The role of tau phosphorylation and tau aggregation in the pathology of a transgenic mouse model that overexpresses GSK-3beta and FTDP-17 tau has been analyzed. In that model we have suggested a possible role for tau phosphorylation, but not for tau aggregation, in the cognitive impairment found in the transgenic mouse.

    Journal of the neurological sciences 2007;257;1-2;250-4

  • Assembly of two distinct dimers and higher-order oligomers from full-length tau.

    Sahara N, Maeda S, Murayama M, Suzuki T, Dohmae N, Yen SH and Takashima A

    Laboratory for Alzheimer's Disease, RIKEN Brain Science Institute, Wako-shi, Saitama, Japan. sahararuhiko@brain.riken.jp

    Abnormal accumulation of tau as filamentous structures is a neuropathological hallmark of neurodegenerative diseases referred to as tauopathies. Little is known about the role of native cysteine residues in tau assembly because their substitution with other amino acids has no effect on tau filament morphology. To understand the process involved in tau oligomerization, we analysed both heparin-induced assembly of different forms of recombinant human tau and assembly of tau from COS-7 cells transiently expressing different human tau constructs. Here, we demonstrated that tau assembly involves two distinct dimers (cysteine-dependent and cysteine-independent) that differ in resistance to reduction. During assembly, an increase of cysteine-dependent tau oligomer was observed prior to detection of increased thioflavin T fluorescence signals. The latter event was accompanied by an increase of cysteine-independent dimer. Fewer higher-order oligomers and aggregates were assembled from four-repeat tau containing two amino-terminus inserts that have either the C291A/C322A mutation (cysless-4R2N) or a hexapeptide deletion at residues 306-311 (DeltaPHF6-4R2N) compared with those assembled from wild-type tau. Assembly of distinct types of dimers was also observed in lysates from COS-7 cells expressing wild-type 4R2N and brain extracts from mice expressing P301L mutant tau. In contrast, COS-7 cells expressing cysless- or DeltaPHF6-4R2N tau contained very little cysteine-dependent dimer. Together, the results indicate that intermolecular disulfide crosslinking along with PHF6 hexapeptide facilitates tau oligomerization and that this event is accompanied by cysteine-independent intermolecular bridging of microtubule-binding domain, leading to assembly of higher-order oligomers. The levels of these dimers may be used to gauge the potential for tau assembly.

    The European journal of neuroscience 2007;25;10;3020-9

  • CSF neurofilament light chain and tau differentiate multiple system atrophy from Parkinson's disease.

    Abdo WF, Bloem BR, Van Geel WJ, Esselink RA and Verbeek MM

    Department of Neurology, Radboud University, Nijmegen Medical Centre, The Netherlands. f.abdo@neuro.umcn.nl

    Background: In early disease stages it can be clinically difficult to differentiate idiopathic Parkinson's disease (IPD) from patients with multiple system atrophy predominated by parkinsonism (MSA-P).

    Methods: In CSF of 31 patients with IPD, 19 patients with MSA-P, we analyzed tau, neurofilament light chain (NFL) and heavy chain (NFHp35) and the noradrenergic metabolite 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG).

    Results: CSF levels of NFL, NFHp35, and tau were significantly increased in MSA-P (all p<0.0001), whereas, MHPG levels were significantly decreased in MSA-P (p<0.0001). Optimal discriminative cut-off values for the differentiation between MSA-P and IPD were calculated resulting in high sensitivity (76-94%) and specificity (83-97%) levels. Multivariate logistic regression resulted in the combination of NFL and tau as independent contributors in differentiating between MSA-P and IPD.

    Discussion: Higher CSF levels of axonal biomarkers could reflect advanced axonal degeneration in MSA-P. Differentiating MSA-P from IPD could be accurately possible with CSF analysis of a combination of axonal and neurotransmitter biomarkers.

    Neurobiology of aging 2007;28;5;742-7

  • Fine mapping of the MAPT locus using quantitative trait analysis identifies possible causal variants in Alzheimer's disease.

    Laws SM, Friedrich P, Diehl-Schmid J, Müller J, Eisele T, Bäuml J, Förstl H, Kurz A and Riemenschneider M

    Neurochemistry and Neurogenetics Laboratory, Department of Psychiatry and Psychotherapy, Technische Universität München, München, Germany.

    In addition to senile plaques, neurofibrillary tangles are characteristic of Alzheimer's disease (AD) pathology, suggesting a clear involvement of the microtubule-associated protein tau (MAPT) in AD. Recent findings, suggesting that the H1c haplotype is associated with increased risk, now also implicate MAPT genetically. In this study, we aim to clarify this association by a fine mapping approach using both a traditional phenotypic association analysis and a quantitative trait (QT) analysis using cerebrospinal fluid (CSF) tau protein levels in the German population. Here, we report that both methodologies identify that the H1c haplotype may play important role in AD (AD risk, P=0.007, uncorrected; CSF tau levels, P=0.027, uncorrected). Further, the use of a sliding window approach in the QT analysis allowed for the narrowing down of the region where a probable causal variant may be located. The data suggest that this may lie at or within close proximity to the rs242557 single nucleotide polymorphism as association with CSF tau levels seems to be primarily driven by rs242557 in a gene dosage-dependent manner (trend model: P=0.002, uncorrected). These findings provide functional evidence to support the genetic association of MAPT with AD.

    Molecular psychiatry 2007;12;5;510-7

  • Genetic variation at the tau locus and clinical syndromes associated with progressive supranuclear palsy.

    Williams DR, Pittman AM, Revesz T, Lees AJ and de Silva R

    The Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, Queen Square, London, United Kingdom. drdavew@bigpond.com

    A number of different clinical syndromes have been associated with progressive supranuclear (PSP) tau pathology. Previous reports have suggested that atypical clinical phenotypes of PSP occur in familial disease, and might be associated with mutations of MAPT. We examined the association of PSP-susceptibility tau haplotypes in pathologically diagnosed PSP, separated according to initial clinical features into classic PSP and atypical PSP groups (PSP-Parkinsonism, PSP-P). These patients were screened for mutations in exons 1 and 10 of MAPT. No mutations were found in 75 patients (21 PSP-P), and H1c was associated with both Richardson's syndrome and PSP-P compared with controls. Routine screening for MAPT mutations in atypical PSP is not recommended.

    Funded by: Medical Research Council: G0501560, G0501560(76517); Parkinson's UK: G-4062

    Movement disorders : official journal of the Movement Disorder Society 2007;22;6;895-7

  • Highly populated turn conformations in natively unfolded tau protein identified from residual dipolar couplings and molecular simulation.

    Mukrasch MD, Markwick P, Biernat J, Bergen Mv, Bernadó P, Griesinger C, Mandelkow E, Zweckstetter M and Blackledge M

    Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.

    Tau, a natively unstructured protein that regulates the organization of neuronal microtubules, is also found in high concentrations in neurofibrillary tangles of Alzheimer's disease and other neurodegenerative disorders. The conformational transition between these vastly different healthy and pathological forms remains poorly understood. We have measured residual dipolar couplings (RDCs), J-couplings, and nuclear Overhauser enhancement (NOE) in construct K18 of tau, containing all four repeat domains R1-R4. NHN RDCs were compared with prediction on the basis of a statistical model describing the intrinsic conformational sampling of unfolded proteins in solution. While local variation and relative amplitude of RDCs agrees with propensity-based prediction for most of the protein, homologous sequences in each repeat domain (DLKN, DLSN, DLSK, and DKFD in repeats R1-R4) show strong disagreement characterized by inversion of the sign of the central couplings. Accelerated molecular dynamic simulations (AMD) in explicit solvent revealed strong tendencies to form turns, identified as type I beta-turns for repeats R1-R3. Incorporation of the backbone dihedral sampling resulting from AMD into the statistical coil model closely reproduces experimental RDC values. These localized sequence-dependent conformational tendencies interrupt the propensity to sample more extended conformations in adjacent strands and are remarkably resistant to local environmental factors, as demonstrated by the persistence of the RDC signature even under harsh denaturing conditions (8 M urea). The role that this specific conformational behavior may play in the transition to the pathological form is discussed.

    Journal of the American Chemical Society 2007;129;16;5235-43

  • The "jaws" of the tau-microtubule interaction.

    Mukrasch MD, von Bergen M, Biernat J, Fischer D, Griesinger C, Mandelkow E and Zweckstetter M

    Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen.

    Tau is the major microtubule-associated protein in neuronal axons. It aggregates into "neurofibrillary tangles" during the course of Alzheimer disease. Binding to microtubules and microtubule assembly requires the "repeat domain" in the C-terminal half of Tau, as well as the two regions flanking the repeats. Here we report the NMR characterization of a 198-residue Tau fragment composed of the four tandem repeats and the flanking domains and containing the full microtubule binding and assembly activity of Tau. NMR secondary chemical shifts and dipolar couplings detect the highest propensity for beta-structure within the four-repeat region, whereas the flanking domains are largely random coil, with an increased rigidity in the proline-rich region. Chemical shift perturbation experiments identify two motifs in the upstream flanking domain, (225)KVAVVRT(231) and (243)LQTA(246), and one downstream of the repeats, (370)KIETHKTFREN(380), which strongly contribute to the binding to the acidic outside of microtubules, as well as to the binding of other polyanions such as heparin. This is consistent with the "jaws" model of Tau-microtubule interactions and highlights the importance of the regions flanking the repeats for both microtubule binding and pathological Tau aggregation.

    The Journal of biological chemistry 2007;282;16;12230-9

  • Accumulation of pathological tau species and memory loss in a conditional model of tauopathy.

    Berger Z, Roder H, Hanna A, Carlson A, Rangachari V, Yue M, Wszolek Z, Ashe K, Knight J, Dickson D, Andorfer C, Rosenberry TL, Lewis J, Hutton M and Janus C

    Mayo Clinic Jacksonville, Jacksonville, Florida 32224, USA.

    Neurofibrillary tangles (NFTs) are a pathological hallmark of Alzheimer's disease and other tauopathies, but recent studies in a conditional mouse model of tauopathy (rTg4510) have suggested that NFT formation can be dissociated from memory loss and neurodegeneration. This suggests that NFTs are not the major neurotoxic tau species, at least during the early stages of pathogenesis. To identify other neurotoxic tau protein species, we performed biochemical analyses on brain tissues from the rTg4510 mouse model and then correlated the levels of these tau proteins with memory loss. We describe the identification and characterization of two forms of tau multimers (140 and 170 kDa), whose molecular weight suggests an oligomeric aggregate, that accumulate early in the pathogenic cascade in this mouse model. Similar tau multimers were detected in a second mouse model of tauopathy (JNPL3) and in tissue from patients with Alzheimer's disease and FTDP-17 (frontotemporal dementia and parkinsonism linked to chromosome 17). Moreover, levels of the tau multimers correlated consistently with memory loss at various ages in the rTg4510 mouse model. Our findings suggest that accumulation of early-stage aggregated tau species, before the formation of NFT, is associated with the development of functional deficits during the pathogenic progression of tauopathy.

    Funded by: NIA NIH HHS: P01-AG014449, P01-AG017216, P30 AG10161; NINDS NIH HHS: P50-NS40256-06, R01-NS4635

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2007;27;14;3650-62

  • Effects of tau phosphorylation on proteasome activity.

    Ren QG, Liao XM, Chen XQ, Liu GP and Wang JZ

    Department of Pathophysiology, Hubei Provincial Key Laboratory of Neurological Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China.

    Dysfunction of proteasome contributes to the accumulation of the abnormally hyperphosphorylated tau in Alzheimer's disease. However, whether tau hyperphosphorylation and accumulation affect the activity of proteasome is elusive. Here we found that a moderate tau phosphorylation activated the trypsin-like activity of proteasome, whereas further phosphorylation of tau inhibited the activity of the protease in HEK293 cells stably expressing tau441. Furthermore, tau hyperphosphorylation could partially reverse lactacystin-induced inhibition of proteasome. These results suggest that phosphorylation of tau plays a dual role in modulating the activity of proteasome.

    FEBS letters 2007;581;7;1521-8

  • The novel Tau mutation G335S: clinical, neuropathological and molecular characterization.

    Spina S, Murrell JR, Yoshida H, Ghetti B, Bermingham N, Sweeney B, Dlouhy SR, Crowther RA, Goedert M and Keohane C

    Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 635 Barnhill Drive MS A138, Indianapolis, IN, 46202, USA. bghetti@iupui.edu

    Mutations in Tau cause the inherited neurodegenerative disease, frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17). Known coding region mutations cluster in the microtubule-binding region, where they alter the ability of tau to promote microtubule assembly. Depending on the tau isoforms, this region consists of three or four imperfect repeats of 31 or 32 amino acids, each of which contains a characteristic and invariant PGGG motif. Here, we report the novel G335S mutation, which changes the PGGG motif of the third tau repeat to PGGS, in an individual who developed social withdrawal, emotional bluntness and stereotypic behavior at age 22, followed by disinhibition, hyperorality and ideomotor apraxia. Abundant tau-positive inclusions were present in neurons and glia in the frontotemporal cortex, hippocampus and brainstem. Sarkosyl-insoluble tau showed paired helical and straight filaments, as well as more irregular rope-like filaments. The pattern of pathological tau bands was like that of Alzheimer disease. Experimentally, the G335S mutation resulted in a greatly reduced ability of tau to promote microtubule assembly, while having no significant effect on heparin-induced assembly of recombinant tau into filaments.

    Funded by: NIA NIH HHS: P30 AG10133

    Acta neuropathologica 2007;113;4;461-70

  • Biochemical and pathological characterization of frontotemporal dementia due to a Leu266Val mutation in microtubule-associated protein tau in an African American individual.

    Van Deerlin VM, Forman MS, Farmer JM, Grossman M, Joyce S, Crowe A, Trojanowski JQ, Lee VM and Chatterjee A

    Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research and Institute on Aging, University of Pennsylvania, 3600 Spruce St., 3 Maloney Bldg., Philadelphia, PA, 19104, USA. vivianna@mail.med.upenn.edu

    Frontotemporal dementia (FTD) is a clinically heterogeneous disorder characterized by alterations in language and/or behavior, often in association with Parkinsonism or motor neuron disease. A familial form of FTD is associated with mutations in the microtubule-associated protein tau (MAPT) gene. We report here on the clinical, neuroimaging, cerebral spinal fluid biomarker, genetic, biochemical and postmortem neuropathological analyses of a case of familial FTD with a Leu266Val MAPT mutation which results in a very early age of onset and a rapid course of disease. This is also the first reported case of any MAPT mutation in an individual of African American ethnicity.

    Funded by: NIA NIH HHS: AG10124, AG17586, K08 AG020073, K08 AG20073, P01 AG017586; NINDS NIH HHS: K08 NS14108, NS44266, R01 NS044266

    Acta neuropathologica 2007;113;4;471-9

  • Identification of a novel risk locus for progressive supranuclear palsy by a pooled genomewide scan of 500,288 single-nucleotide polymorphisms.

    Melquist S, Craig DW, Huentelman MJ, Crook R, Pearson JV, Baker M, Zismann VL, Gass J, Adamson J, Szelinger S, Corneveaux J, Cannon A, Coon KD, Lincoln S, Adler C, Tuite P, Calne DB, Bigio EH, Uitti RJ, Wszolek ZK, Golbe LI, Caselli RJ, Graff-Radford N, Litvan I, Farrer MJ, Dickson DW, Hutton M and Stephan DA

    Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA.

    To date, only the H1 MAPT haplotype has been consistently associated with risk of developing the neurodegenerative disease progressive supranuclear palsy (PSP). We hypothesized that additional genetic loci may be involved in conferring risk of PSP that could be identified through a pooling-based genomewide association study of >500,000 SNPs. Candidate SNPs with large differences in allelic frequency were identified by ranking all SNPs by their probe-intensity difference between cohorts. The MAPT H1 haplotype was strongly detected by this methodology, as was a second major locus on chromosome 11p12-p11 that showed evidence of association at allelic (P<.001), genotypic (P<.001), and haplotypic (P<.001) levels and was narrowed to a single haplotype block containing the DNA damage-binding protein 2 (DDB2) and lysosomal acid phosphatase 2 (ACP2) genes. Since DNA damage and lysosomal dysfunction have been implicated in aging and neurodegenerative processes, both genes are viable candidates for conferring risk of disease.

    Funded by: NIA NIH HHS: F32 AG024030, P01 AG 17216, P01 AG017216; NINDS NIH HHS: 1U24NS043571, U24 NS043571

    American journal of human genetics 2007;80;4;769-78

  • Microtubule-associated protein tau as a therapeutic target in neurodegenerative disease.

    Roder HM and Hutton ML

    Mayo Clinic, Department of Neuroscience, 4500 San Pablo Road, Jacksonville, FL 32224, USA. roder.hanno@mayo.edu

    Interest in the biology of the microtubule-associated protein tau, not only as a pathologic marker, but as a therapeutic target has surged considerably over the last few years. This is due, in part, to the discovery of mutations in tau causing a group of aggressively degenerative neurologic disorders characterized by abnormalities of tau very similar to what is seen in Alzheimer's disease where mutations in tau are absent. As these same mutations also precipitate authentic forms of neurofibrillary degeneration in tau transgenic mice, the gateways to testing therapeutic ideas preclinically have opened. Other Alzheimer's disease animal models have been notoriously bare of this feature, limiting their predictive power for clinical success. In this review, the authors discuss some of the main therapeutic ideas presently advanced in the field and their molecular rationales.

    Expert opinion on therapeutic targets 2007;11;4;435-42

  • NMR investigation of the interaction between the neuronal protein tau and the microtubules.

    Sillen A, Barbier P, Landrieu I, Lefebvre S, Wieruszeski JM, Leroy A, Peyrot V and Lippens G

    CNRS UMR 8576 Unité de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille 1, 59655, Villeneuve d'Ascq Cedex, France.

    Whereas the interaction between Tau and the microtubules has been studied in great detail both by macroscopic techniques (cosedimentation, cryo-electron microscopy, and fluorescence spectroscopy) using the full-length protein or by peptide mapping assays, no detailed view at the level of individual amino acids has been presented when using the full-length protein. Here, we present a nuclear magnetic resonance (NMR) study of the interaction between the full-length neuronal protein Tau and paclitaxel-stabilized microtubules (MTs). As signal disappearance in the heteronuclear 1H-15N correlation spectra of isotope-labeled Tau in complex with MTs is due to direct association of the corresponding residue with the solid-like MT wall, we can map directly the fragment in interaction with the MT surface, and obtain a molecular picture of the precise interaction zones. The N-terminal region projects from the microtubule surface, and the lack of chemical shift variations when compared with free Tau proves that this region can regulate microtubular separation without adopting a stable conformation. Amino acids in the four microtubule binding repeats (MTBRs) lose all of their intensity, underscoring their immobilization upon binding to the MTs. The same loss of NMR intensity was observed for the proline-rich region starting at Ser214, underscoring its importance in the Tau:MT interaction. Fluorescence resonance energy transfer (FRET) experiments were used to obtain thermodynamic binding parameters, and led to the conclusion that the NMR defined fragment indeed is the major player in the interaction. When the same Ser214 is phosphorylated by the PKA kinase, the Tau:MT interaction strength decreases by 2 orders of magnitude, but the proline-rich region including the phospho-Ser214 does not gain sufficient mobility in the complex to make it observable by NMR spectroscopy. The presence of an intramolecular disulfide bridge, on the contrary, does lead to a partial detachment of the C-terminus of Tau, and decreases significantly the overloading of Tau on the MT surface.

    Biochemistry 2007;46;11;3055-64

  • Phenotypic associations of tau and ApoE in Parkinson's disease.

    Papapetropoulos S, Farrer MJ, Stone JT, Milkovic NM, Ross OA, Calvo L, McQuorquodale D and Mash DC

    Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL 33136, United States. spapapetropoulos@med.miami.edu

    Overlaps in clinical, pathological and molecular features of Parkinson's disease (PD), dementing and motor tauopathies have prompted association studies in search of common genetic risk factors that may predispose or modify this spectrum of disorders. To explore possible phenotypic implications, we studied common tau and ApoE gene polymorphisms, associated with Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and PD, in a clinically and pathologically characterized cohort of PD patients and aged control subjects. Our results reveal a novel association between PD-related hallucinations and H1H1 genotype. We also report an association between PDD and the presence of the ApoE epsilon4 allele. Better determination of subsets of PD patients based upon the presence of specific phenotypic features may improve the accuracy of association studies.

    Funded by: NIA NIH HHS: P01 AG17216; NIEHS NIH HHS: R01 ES013941; NIMH NIH HHS: R03 MH074059, R03 MH074059-02; NINDS NIH HHS: P50 NS40256

    Neuroscience letters 2007;414;2;141-4

  • Cytoskeleton proteins are modulators of mutant tau-induced neurodegeneration in Drosophila.

    Blard O, Feuillette S, Bou J, Chaumette B, Frébourg T, Campion D and Lecourtois M

    Inserm U614 (IFRMP), University of Rouen & Department of Genetics, Rouen University Hospital, Institute for Biomedical Research, Rouen, France.

    Tauopathies, including Alzheimer's disease and fronto-temporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), are a group of neurodegenerative disorders characterized by the presence of intraneuronal filamentous inclusions of aberrantly phosphorylated-tau. Tau is a neuronal microtubule-associated protein involved in microtubule assembly and stabilization. Currently, the molecular mechanisms underlying tau-mediated cellular toxicity remain elusive. To address the determinants of tau neurotoxicity, we first characterized the cellular alterations resulting from the over-expression of a mutant form of human tau associated with FTDP-17 (tau V337M) in Drosophila. We found that the over-expression of tau V337M, in Drosophila larval motor neurons, induced disruption of the microtubular network at presynaptic nerve terminals and changes in neuromuscular junctions morphological features. Secondly, we performed a misexpression screen to identify genetic modifiers of the tau V337M-mediated rough eye phenotype. The screening of 1250 mutant Drosophila lines allowed us to identify several components of the cytoskeleton, and particularly from the actin network, as specific modifiers of tau V337M-induced neurodegeneration. Furthermore, we found that numerous tau modulators identified in our screen were involved in the maintenance of synaptic function. Taken together, these findings suggest that disruption of the microtubule network in presynaptic nerve terminals could constitute early events in the pathological process leading to synaptic dysfunction in tau V337M pathology.

    Human molecular genetics 2007;16;5;555-66

  • The high-affinity HSP90-CHIP complex recognizes and selectively degrades phosphorylated tau client proteins.

    Dickey CA, Kamal A, Lundgren K, Klosak N, Bailey RM, Dunmore J, Ash P, Shoraka S, Zlatkovic J, Eckman CB, Patterson C, Dickson DW, Nahman NS, Hutton M, Burrows F and Petrucelli L

    Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, Florida, USA.

    A primary pathologic component of Alzheimer's disease (AD) is the formation of neurofibrillary tangles composed of hyperphosphorylated tau (p-tau). Expediting the removal of these p-tau species may be a relevant therapeutic strategy. Here we report that inhibition of Hsp90 led to decreases in p-tau levels independent of heat shock factor 1 (HSF1) activation. A critical mediator of this mechanism was carboxy terminus of Hsp70-interacting protein (CHIP), a tau ubiquitin ligase. Cochaperones were also involved in Hsp90-mediated removal of p-tau, while those of the mature Hsp90 refolding complex prevented this effect. This is the first demonstration to our knowledge that blockade of the refolding pathway promotes p-tau turnover through degradation. We also show that peripheral administration of a novel Hsp90 inhibitor promoted selective decreases in p-tau species in a mouse model of tauopathy, further suggesting a central role for the Hsp90 complex in the pathogenesis of tauopathies. When taken in the context of known high-affinity Hsp90 complexes in affected regions of the AD brain, these data implicate a central role for Hsp90 in the development of AD and other tauopathies and may provide a rationale for the development of novel Hsp90-based therapeutic strategies.

    Funded by: NIA NIH HHS: P01 AG017216, P01-AG17216; NINDS NIH HHS: P50 NS040256, P50-NS40256

    The Journal of clinical investigation 2007;117;3;648-58

  • The MAPT H1c risk haplotype is associated with increased expression of tau and especially of 4 repeat containing transcripts.

    Myers AJ, Pittman AM, Zhao AS, Rohrer K, Kaleem M, Marlowe L, Lees A, Leung D, McKeith IG, Perry RH, Morris CM, Trojanowski JQ, Clark C, Karlawish J, Arnold S, Forman MS, Van Deerlin V, de Silva R and Hardy J

    Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892-3707, USA.

    Previously we have shown that the H1c haplotype on the background of the H1 clade of haplotypes at the MAPT locus is associated with increased risk for progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and Alzheimer's disease (AD). Here we replicated the association with AD in an additional autopsy confirmed series. We show that this haplotype increases both the expression of total MAPT transcript as well as specifically increasing the proportion of 4 microtubule binding repeat containing transcripts. We discuss these findings both in terms of the problems facing the dissection of the etiologies of complex traits and the pathogenesis of the tauopathies.

    Funded by: Intramural NIH HHS; Medical Research Council: G0501560, G0501560(76517), G0701075; NIA NIH HHS: AG 05146, AG-10124, AG-17586, AG05128, P30-AG13846, P50 AG16570, P50-AG08671; NIMH NIH HHS: MH60451; NINDS NIH HHS: NS39764

    Neurobiology of disease 2007;25;3;561-70

  • Two sites in the MAPT region confer genetic risk for Guam ALS/PDC and dementia.

    Sundar PD, Yu CE, Sieh W, Steinbart E, Garruto RM, Oyanagi K, Craig UK, Bird TD, Wijsman EM, Galasko DR and Schellenberg GD

    Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA 98195, USA.

    Unusual forms of amyotrophic lateral sclerosis (ALS-G), Parkinsonism dementia complex (PDC-G) and Guam dementia (GD) are found in Chamorros, the indigenous people of Guam. Neurofibrillary tangles composed of hyperphosphorylated tau are a neuropathologic feature of these closely related disorders. To determine if variation in the gene that encodes microtubule-associated protein tau gene (MAPT) contributes to risk for these disorders, we genotyped nine single nucleotide polymorphism (SNP) sites and one insertion/deletion in the 5' end of MAPT in 54 ALS-G, 135 PDC-G, 153 GD and 258 control subjects, all of whom are Chamorros. Variation at three SNPs (sites 2, 6 and 9) influenced risk for ALS-G, PDC-G and GD. SNP2 acts through a dominant mechanism and is independent of the risk conferred by SNPs 6 and 9, the latter two acting by a recessive mechanism. Persons with the high-risk SNP6 and SNP9 AC/AC diplotype had an increased risk of 3-fold [95% confidence interval (CI)=1.10-8.25] for GD, 4-fold (95% CI=1.40-11.64) for PDC-G and 6-fold (95% CI=1.44-32.14) for ALS-G, compared to persons with other diplotypes after adjusting for SNP2. Carriers of the SNP2 G allele had an increased risk of 1.6-fold (95% CI=1.00-2.62) for GD, 2-fold (95% CI=1.28-3.66) for PDC-G, and 1.5-fold (95% CI=0.74-3.00) for ALS-G, compared to non-carriers after adjusting for SNPs 6 and 9. Others have shown that SNP6 is also associated with risk for progressive supranuclear palsy. These two independent cis-acting sites presumably influence risk for Guam neuro-degenerative disorders by regulating MAPT expression.

    Funded by: NIA NIH HHS: P01 AG14382, P50 AG 05136

    Human molecular genetics 2007;16;3;295-306

  • Haplotype-based association analysis of the MAPT locus in late onset Alzheimer's disease.

    Mukherjee O, Kauwe JS, Mayo K, Morris JC and Goate AM

    Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA. odity@icarus.wustl.edu <odity@icarus.wustl.edu&gt;

    Background: Late onset Alzheimer's disease (LOAD) is a common sporadic form of the illness, affecting individuals above the age of 65 yrs. A prominent hypothesis for the aetiopathology of Alzheimer's disease is that in the presence of a beta-amyloid load, individuals expressing a pathogenic form of tau protein (MAPT) are at increased risk for developing the disease. Genetic studies in this pursuit have, however, yielded conflicting results. A recent study showed a significant haplotype association (H1c) with AD. The current study is an attempt to replicate this association in an independently ascertained cohort.

    Results: In this report we present the findings of a haplotype analysis at the MAPT locus. We failed to detect evidence of association of the H1c haplotype at the MAPT locus with LOAD. None of the six SNPs forming the H1c haplotype showed evidence of association with disease. In addition, nested clade analysis suggested the presence of independent mutations at multiple points in the haplotype network or homoplasy at the MAPT locus. Such homoplasy can confound single SNP tests for association. We do not detect evidence that the set of SNPs forming the H1c haplotype in general or rs242557 in particular are pathogenic for LOAD.

    Conclusion: In conclusion, we employed two contemporary haplotype analysis tools to perform haplotype association analysis at the MAPT locus. Our data suggest that the tagged SNPs forming the H1c haplotype do not have a causal role in the pathogenesis of LOAD.

    Funded by: FIC NIH HHS: TW 0511-05; NIA NIH HHS: AG016208, P01 AG003991, P01 AG03991, P50 AG005681, P50 AG05681, R01 AG016208

    BMC genetics 2007;8;3

  • Neurodegeneration caused by expression of human truncated tau leads to progressive neurobehavioural impairment in transgenic rats.

    Hrnkova M, Zilka N, Minichova Z, Koson P and Novak M

    Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, 845 10, Bratislava, Slovakia.

    Human truncated tau protein is an active constituent of the neurofibrillary degeneration in sporadic Alzheimer's disease. We have shown that modified tau protein, when expressed as a transgene in rats, induced AD characteristic tau cascade consisting of tau hyperphosphorylation, formation of argyrophilic tangles and sarcosyl-insoluble tau complexes. These pathological changes led to the functional impairment characterized by a variety of neurobehavioural symptoms. In the present study we have focused on the behavioural alterations induced by transgenic expression of human truncated tau. Transgenic rats underwent a battery of behavioural tests involving cognitive- and sensorimotor-dependent tasks accompanied with neurological assessment at the age of 4.5, 6 and 9 months. Behavioural examination of these rats showed altered spatial navigation in Morris water maze resulting in less time spent in target quadrant (p<0.05) and fewer crossings over previous platform position (p<0.05) during probe trial. Spontaneous locomotor activity and anxiety in open field was not influenced by transgene expression. However beam walking test revealed that transgenic rats developed progressive sensorimotor disturbances related to the age of tested animals. The disturbances were most pronounced at the age of 9 months (p<0.01). Neurological alterations indicating impaired reflex responses were other added features of behavioural phenotype of this novel transgenic rat. These results allow us to suggest that neurodegeneration, caused by the non-mutated human truncated tau derived from sporadic human AD, result in the neuronal dysfunction consequently leading to the progressive neurobehavioural impairment.

    Brain research 2007;1130;1;206-13

  • The DYRK1A gene, encoded in chromosome 21 Down syndrome critical region, bridges between beta-amyloid production and tau phosphorylation in Alzheimer disease.

    Kimura R, Kamino K, Yamamoto M, Nuripa A, Kida T, Kazui H, Hashimoto R, Tanaka T, Kudo T, Yamagata H, Tabara Y, Miki T, Akatsu H, Kosaka K, Funakoshi E, Nishitomi K, Sakaguchi G, Kato A, Hattori H, Uema T and Takeda M

    Department of Psychiatry, Osaka University Graduate School of Medicine, 2-2-D3 Yamadaoka, Suita, Osaka 565-0871, Japan.

    We scanned throughout chromosome 21 to assess genetic associations with late-onset Alzheimer disease (AD) using 374 Japanese patients and 375 population-based controls, because trisomy 21 is known to be associated with early deposition of beta-amyloid (Abeta) in the brain. Among 417 markers spanning 33 Mb, 22 markers showed associations with either the allele or the genotype frequency (P < 0.05). Logistic regression analysis with age, sex and apolipoprotein E (APOE)-epsilon4 dose supported genetic risk of 17 markers, of which eight markers were linked to the SAMSN1, PRSS7, NCAM2, RUNX1, DYRK1A and KCNJ6 genes. In logistic regression, the DYRK1A (dual-specificity tyrosine-regulated kinase 1A) gene, located in the Down syndrome critical region, showed the highest significance [OR = 2.99 (95% CI: 1.72-5.19), P = 0.001], whereas the RUNX1 gene showed a high odds ratio [OR = 23.3 (95% CI: 2.76-196.5), P = 0.038]. DYRK1A mRNA level in the hippocampus was significantly elevated in patients with AD when compared with pathological controls (P < 0.01). DYRK1A mRNA level was upregulated along with an increase in the Abeta-level in the brain of transgenic mice, overproducing Abeta at 9 months of age. In neuroblastoma cells, Abeta induced an increase in the DYRK1A transcript, which also led to tau phosphorylation at Thr212 under the overexpression of tau. Therefore, the upregulation of DYRK1A transcription results from Abeta loading, further leading to tau phosphorylation. Our result indicates that DYRK1A could be a key molecule bridging between beta-amyloid production and tau phosphorylation in AD.

    Human molecular genetics 2007;16;1;15-23

  • Hereditary frontotemporal dementia caused by Tau gene mutations.

    van Swieten J and Spillantini MG

    Erasmus Medical Centre, Rotterdam, The Netherlands. j.c.vanswieten@erasmusmc.nl

    Tau protein is involved in microtubule assembly and stabilization. Filamentous deposits made of tau constitute a defining characteristic of several neurodegenerative diseases. The relevance of tau dysfunction for neurodegeneration has been clarified through the identification of mutations in the Tau gene in cases with frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). Although the mechanisms by which these mutations lead to nerve cell death are only incompletely understood, it is clear that they cause the formation of tau filaments with distinct morphologies and isoform compositions. The range of tau pathology identified in FTDP-17 recapitulates that in sporadic tauopathies, indicating a major role for tau dysfunction in these diseases.

    Brain pathology (Zurich, Switzerland) 2007;17;1;63-73

  • Brain tau expression and correlation with the H1/H1 tau genotype in frontotemporal lobar degeneration patients.

    Lladó A, Ezquerra M, Gaig C, Sánchez-Valle R, Tolosa E and Molinuevo JL

    Alzheimer's Disease and Other Cognitive Disorders Unit, Service of Neurology, Hospital Clínic and Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain.

    Alterations in tau mRNA splicing and association with H1/H1 tau genotype have been described in some sporadic tauopathies. We evaluated the 4R/3R tau mRNA ratio in 18 patients with frontotemporal lobar degeneration (FTLD), and the effect of the H1/H1 genotype on this ratio. The 4R/3R mRNA ratio in frontal cortex was similar in FTLD patients and controls. The H1/H1 genotype carriers showed a significant increase in 4R/3R mRNA ratio, suggesting that this genotype could modulate the tau mRNA splicing.

    Journal of neural transmission (Vienna, Austria : 1996) 2007;114;12;1585-8

  • Chronological changes in MRI and CSF biochemical markers in Creutzfeldt-Jakob disease patients.

    Satoh K, Shirabe S, Eguchi H, Tsujino A, Motomura M, Satoh A, Tsujihata M and Eguchi K

    First Department of Internal Medicine, Graduate School of Biomedical Science, Nagasaki University, Nagasaki, Japan. f1537@cc.nagasaki-u.ac.jp

    Background: There are currently no markers for evaluating chronological changes in Creutzfeldt-Jakob disease (CJD). We examined if chronological changes in biochemical markers in cerebrospinal fluid (CSF) and diffusion-weighted magnetic resonance imaging (DWI) were utilizable for this purpose.

    Methods: Ten independent patients were divided into two groups of 5 patients each. We analyzed CSF biochemical markers, DWI and the clinical course in one group. In the remaining group, only the CSF biochemical markers were analyzed before and after the onset of akinetic mutism.

    Results: The level of total tau (t-tau) protein in CSF in the early phase after disease onset was 2,655 +/- 423.9 pg/ml, reaching a mean peak of 14,675 +/- 1,240 pg/ml in the middle phase and gradually declining after that. Just before patients deteriorated into akinetic mutism, t-tau protein titers reached a maximum (8,786 +/- 2,975 pg/ml). There were dramatic changes in t-tau protein levels throughout the clinical course, unlike the other markers. DWI was not always utilizable, because of discordance with clinical symptoms seen in this study. Four cases exhibited peaks in t-tau protein levels while the patients fell into akinetic mutism except 1 case.

    Conclusion: Our results suggest that t-tau protein is the most sensitive marker of disease progression in CJD patients.

    Dementia and geriatric cognitive disorders 2007;23;6;372-81

  • Increase in beta-amyloid levels in cerebrospinal fluid of children with Down syndrome.

    Englund H, Annerén G, Gustafsson J, Wester U, Wiltfang J, Lannfelt L, Blennow K and Höglund K

    Department of Public Health and Caring Sciences, Section of Molecular Geriatrics, Uppsala University, and Department of Women's and Children's Health, Uppsala University Children's Hospital, Sweden.

    Background: Individuals with Down syndrome (DS) invariably develop Alzheimer's disease (AD) during their life span. It is therefore of importance to study young DS patients when trying to elucidate early events in AD pathogenesis.

    Aim: To investigate how levels of different amyloid-beta (Abeta) peptides, as well as tau and phosphorylated tau, in cerebrospinal fluid (CSF) from children with DS change over time. The first CSF sample was taken at 8 months and the following two samples at 20-40 and 54 months of age.

    Results: Individual levels of the Abeta peptides, as well as total Abeta levels in CSF increased over time when measured with Western blot. Tau in CSF decreased whereas there was no change in levels of phosphorylated tau over time.

    Conclusion: The increasing levels of Abeta in CSF during early childhood of DS patients observed in this study are probably due to the trisomy of the Abeta precursor APP, which leads to an overproduction of Abeta. Despite the increased CSF concentrations of Abeta, there were no signs of an AD-indicating tau pattern in CSF, since the levels of total tau decreased and phosphorylated tau remained unchanged. This observation further strengthens the theory of Abeta pathology preceding tau pathology in AD.

    Dementia and geriatric cognitive disorders 2007;24;5;369-74

  • Dysregulation of tau phosphorylation is a hypothesized point of convergence in the pathogenesis of alzheimer's disease, frontotemporal dementia and schizophrenia with therapeutic implications.

    Deutsch SI, Rosse RB and Lakshman RM

    Mental Health Service Line and Research Service, Department of Veterans Affairs Medical Center, 50 Irving Street, NW, Washington, DC 20422, United States. Stephen.Deutsch@med.va.gov

    Two members of the family of low-density lipoprotein receptors (i.e., very low-density lipoprotein [VLDL] receptor and apolipoprotein E [apoE] type 2 receptor) are expressed in brain, where they bind and transduce reelin, a secreted glycoprotein that shares structural analogies with extracellular matrix proteins. In the developing fetal brain, reelin-signal transduction is critical for the correct positioning of neurons and the formation of appropriate synaptic connections, whereas in the mature brain, reelin participates in the mediation of experience-dependent synaptic plasticity. An important "downstream" consequence of the reelin-signal transduction cascade is inhibition of the phosphorylation of tau, a protein that regulates microtubule assembly and stability. Importantly, hyperphosphorylated tau comprises the paired helical filament, whose pathological deposition as neurofibrillary tangles is implicated in Alzheimer's disease; hyperphosphorylated tau is also implicated in the pathogenesis of other neurodegenerative disorders. Isoforms of apoE may affect the binding of reelin to its cell surface receptors and, thereby, influence tau phosphorylation, whereas insulin, insulin-like growth factor-1, and the lithium ion have actions within the cell at the level of the specific tyrosine kinases involved in the phosphorylation of tau. These data support the exploration of pharmacotherapeutic interventions designed to prevent or reduce the burden of hyperphosphorylated tau. Impaired reelin-signal transduction due to an actual deficiency of reelin expression may occur in at least some patients with psychotic disorders, especially schizophrenia; conceivably, hyperphosphorylation of tau would result from deficient transduction of reelin in schizophrenia. Schizophrenia has been conceptualized as a neurodevelopmental disorder of impaired synaptic "connectivity", whose consequence does not become fully apparent until late adolescence or early adulthood. In summary, hyperphosphorylation of tau may be an underlying point of pathological convergence for several neuropsychiatric disorders, and prevention of tau hyperphosphorylation may be an important therapeutic target.

    Progress in neuro-psychopharmacology & biological psychiatry 2006;30;8;1369-80

  • Characterization of two VQIXXK motifs for tau fibrillization in vitro.

    Li W and Lee VM

    Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

    Tau proteins are building blocks of the filaments that form neurofibrillary tangles of Alzheimer's disease (AD) and related neurodegenerative tauopathies. It was recently reported that two VQIXXK motifs in the microtubule (MT) binding region, named PHF6 and PHF6*, are responsible for tau fibrillization. However, the exact role each of these motifs plays in this process has not been analyzed in detail. Using a recombinant human tau fragment containing only the four MT-binding repeats (K18), we show that deletion of either PHF6 or PHF6* affected tau assembly but only PHF6 is essential for filament formation, suggesting a critical role of this motif. To determine the amino acid residues within PHF6 that are required for tau fibrillization, a series of deletion and mutation constructs targeting this motif were generated. Deletion of VQI in either PHF6 or PHF6* lessened but did not eliminate K18 fibrillization. However, removal of the single K311 residue from PHF6 completely abrogated the fibril formation of K18. K311D mutation of K18 inhibited tau filament formation, while K311A and K311R mutations had no effect. These data imply that charge change at position 311 is important in tau fibril formation. A similar requirement of nonnegative charge at this position for fibrillization was observed with the full-length human tau isoform (T40), and data from these studies indicate that the formation of fibrils by T40K311D and T40K311P mutants is repressed at the nucleation phase. These findings provide important insights into the mechanisms of tau fibrillization and suggest targets for AD drug discovery to ameliorate neurodegeneration mediated by filamentous tau pathologies.

    Biochemistry 2006;45;51;15692-701

  • Reduction of soluble Abeta and tau, but not soluble Abeta alone, ameliorates cognitive decline in transgenic mice with plaques and tangles.

    Oddo S, Vasilevko V, Caccamo A, Kitazawa M, Cribbs DH and LaFerla FM

    Departments of Neurobiology and Behavior and Neurology, and Institute for Brain Aging and Dementia, University of California, Irvine, California 92697, USA.

    Increasing evidence points to soluble assemblies of aggregating proteins as a major mediator of neuronal and synaptic dysfunction. In Alzheimer disease (AD), soluble amyloid-beta (Abeta) appears to be a key factor in inducing synaptic and cognitive abnormalities. Here we report the novel finding that soluble tau also plays a role in the cognitive decline in the presence of concomitant Abeta pathology. We describe improved cognitive function following a reduction in both soluble Abeta and tau levels after active or passive immunization in advanced aged 3xTg-AD mice that contain both amyloid plaques and neurofibrillary tangles (NFTs). Notably, reducing soluble Abeta alone did not improve the cognitive phenotype in mice with plaques and NFTs. Our results show that Abeta immunotherapy reduces soluble tau and ameliorates behavioral deficit in old transgenic mice.

    Funded by: NIA NIH HHS: AG0212982, AG20241

    The Journal of biological chemistry 2006;281;51;39413-23

  • TDP-43 is a component of ubiquitin-positive tau-negative inclusions in frontotemporal lobar degeneration and amyotrophic lateral sclerosis.

    Arai T, Hasegawa M, Akiyama H, Ikeda K, Nonaka T, Mori H, Mann D, Tsuchiya K, Yoshida M, Hashizume Y and Oda T

    Department of Psychogeriatrics, Tokyo Institute of Psychiatry, Setagaya-ku, Tokyo 156-8585, Japan. arai@prit.go.jp

    Ubiquitin-positive tau-negative neuronal cytoplasmic inclusions and dystrophic neurites are common pathological features in frontotemporal lobar degeneration (FTLD) with or without symptoms of motor neuron disease and in amyotrophic lateral sclerosis (ALS). Using biochemical and immunohistochemical analyses, we have identified a TAR DNA-binding protein of 43 kDa (TDP-43), a nuclear factor that functions in regulating transcription and alternative splicing, as a component of these structures in FTLD. Furthermore, skein-like inclusions, neuronal intranuclear inclusions, and glial inclusions in the spinal cord of ALS patients are also positive for TDP-43. Dephosphorylation treatment of the sarkosyl insoluble fraction has shown that abnormal phosphorylation takes place in accumulated TDP-43. The common occurrence of intracellular accumulations of TDP-43 supports the hypothesis that these disorders represent a clinicopathological entity of a single disease, and suggests that they can be newly classified as a proteinopathy of TDP-43.

    Biochemical and biophysical research communications 2006;351;3;602-11

  • Haplotype-specific expression of exon 10 at the human MAPT locus.

    Caffrey TM, Joachim C, Paracchini S, Esiri MM and Wade-Martins R

    The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.

    Neurofibrillary tangles composed of exon 10+ microtubule associated protein tau (MAPT) deposits are the characteristic feature of the neurodegenerative diseases progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). PSP, CBD and more recently Alzheimer's disease and Parkinson's disease, are associated with the MAPT H1 haplotype, but the relationship between genotype and disease remains unclear. Here, we investigate the hypothesis that H1 expresses more exon 10+ MAPT mRNA compared to the other haplotype, H2, leading to a greater susceptibility to neurodegeneration in H1 carriers. We performed allele-specific gene expression on two H1/H2 heterozygous human neuronal cell lines, and 14 H1/H2 heterozygous control individual post-mortem brain tissue from two brain regions. In both tissue culture and post-mortem brain tissue, we show that the MAPT H1 haplotype expresses significantly more exon 10+ MAPT mRNA than H2. In post-mortem brain tissue, we show that the total level of MAPT expression from H1 and H2 is not significantly different, but that the H1 chromosome expresses up to 1.43-fold more exon 10+ MAPT mRNA than H2 in the globus pallidus, a brain region highly affected by tauopathy (maximum exon 10+ MAPT H1:H2 transcript ratio=1.425, SD=0.205, P<0.0001), and up to 1.29-fold more exon 10+ MAPT mRNA than H2 in the frontal cortex (maximum exon 10+ MAPT H1:H2 transcript ratio=1.291, SD=0.315, P=0.006). These data may explain the increased susceptibility of H1 carriers to neurodegeneration and suggest a potential mechanism between MAPT genetic variability and the pathogenesis of neurodegenerative disease.

    Funded by: Wellcome Trust

    Human molecular genetics 2006;15;24;3529-37

  • Phosphorylation inhibits turnover of the tau protein by the proteasome: influence of RCAN1 and oxidative stress.

    Poppek D, Keck S, Ermak G, Jung T, Stolzing A, Ullrich O, Davies KJ and Grune T

    Research Institute of Environmental Medicine, Heinrich Heine University, Düsseldorf, Germany.

    Hyperphosphorylated tau proteins accumulate in the paired helical filaments of neurofibrillary tangles seen in such tauopathies as Alzheimer's disease. In the present paper we show that tau turnover is dependent on degradation by the proteasome (inhibited by MG132) in HT22 neuronal cells. Recombinant human tau was rapidly degraded by the 20 S proteasome in vitro, but tau phosphorylation by GSK3beta (glycogen synthase kinase 3beta) significantly inhibited proteolysis. Tau phosphorylation was increased in HT22 cells by OA [okadaic acid; which inhibits PP (protein phosphatase) 1 and PP2A] or CsA [cyclosporin A; which inhibits PP2B (calcineurin)], and in PC12 cells by induction of a tet-off dependent RCAN1 transgene (which also inhibits PP2B). Inhibition of PP1/PP2A by OA was the most effective of these treatments, and tau hyperphosphorylation induced by OA almost completely blocked tau degradation in HT22 cells (and in cell lysates to which purified proteasome was added) even though proteasome activity actually increased. Many tauopathies involve both tau hyperphosphorylation and the oxidative stress of chronic inflammation. We tested the effects of both cellular oxidative stress, and direct tau oxidative modification in vitro, on tau proteolysis. In HT22 cells, oxidative stress alone caused no increase in tau phosphorylation, but did subtly change the pattern of tau phosphorylation. Tau was actually less susceptible to direct oxidative modification than most cell proteins, and oxidized tau was degraded no better than untreated tau. The combination of oxidative stress plus OA treatment caused extensive tau phosphorylation and significant inhibition of tau degradation. HT22 cells transfected with tau-CFP (cyan fluorescent protein)/tau-GFP (green fluorescent protein) constructs exhibited significant toxicity following tau hyperphosphorylation and oxidative stress, with loss of fibrillar tau structure throughout the cytoplasm. We suggest that the combination of tau phosphorylation and tau oxidation, which also occurs in tauopathies, may be directly responsible for the accumulation of tau aggregates.

    Funded by: NIEHS NIH HHS: ES 03598, R01 ES003598, R56 ES003598

    The Biochemical journal 2006;400;3;511-20

  • Side chain-dependent stacking modulates tau filament structure.

    Margittai M and Langen R

    Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.

    The misfolding of proteins into highly ordered fibrils with similar physical properties is a hallmark of many degenerative diseases. Here, we use the microtubule associated protein tau as a model system to investigate the role of amino acid side chains in the formation of such fibrils. We identify a region (positions 272-289) in the tau protein that, in the fibrillar state, either forms part of a core of parallel, in-register, beta-strands, or remains unfolded. Single point mutations are sufficient to control this conformational switch with disease mutants G272V and DeltaK280 (found in familial forms of dementia) inducing a folded state. Through systematic mutagenesis we derive a propensity scale for individual amino acids to form fibrils with parallel, in-register, beta-strands. This scale should not only apply to tau fibrils but generally to all fibrils with same strand arrangement.

    The Journal of biological chemistry 2006;281;49;37820-7

  • Removal of pattern-breaking sequences in microtubule binding repeats produces instantaneous tau aggregation and toxicity.

    Iliev AI, Ganesan S, Bunt G and Wouters FS

    Cell Biophysics Group, European Neuroscience Institute-Göttingen, Waldweg 33, 37073 Göttingen, Germany. ailiev@gwdg.de

    Aggregated and highly phosphorylated tau protein is a pathological hallmark of Alzheimer's disease (AD) and other tauopathies. We identified motifs of alternating polar and apolar amino acids within the microtubule-binding repeats of tau which were interrupted by small breaking stretches. Minimal mutation of these breaking sequences yielded a unique instantly aggregating tau mutant containing longer stretches of polar/apolar amino acids without losing its microtubule-binding capacity. These modifications produced rapid aggregation and cytotoxicity with accompanying occurrence of pathologic tau phosphoepitopes (AT8, AT180, AT270, AT100, Ser(422), and PHF-1) and conformational epitopes (MC-1 and Alz50) in cells. Similar to pathological tau in the pretangle state, toxicity appeared to occur early without the requirement for extensive fibril formation. Thus, our mutant protein provides a novel platform for the investigation of the molecular mechanisms for toxicity and cellular behavior of pathologically aggregated tau proteins and the identification of its interaction partners.

    The Journal of biological chemistry 2006;281;48;37195-204

  • Tau-dependent microtubule disassembly initiated by prefibrillar beta-amyloid.

    King ME, Kan HM, Baas PW, Erisir A, Glabe CG and Bloom GS

    Department of Biology, University of Virginia, Charlottesville, VA 22904, USA. mk2j@virginia.edu

    Alzheimer's Disease (AD) is defined histopathologically by extracellular beta-amyloid (Abeta) fibrils plus intraneuronal tau filaments. Studies of transgenic mice and cultured cells indicate that AD is caused by a pathological cascade in which Abeta lies upstream of tau, but the steps that connect Abeta to tau have remained undefined. We demonstrate that tau confers acute hypersensitivity of microtubules to prefibrillar, extracellular Abeta in nonneuronal cells that express transfected tau and in cultured neurons that express endogenous tau. Prefibrillar Abeta42 was active at submicromolar concentrations, several-fold below those required for equivalent effects of prefibrillar Abeta40, and microtubules were insensitive to fibrillar Abeta. The active region of tau was localized to an N-terminal domain that does not bind microtubules and is not part of the region of tau that assembles into filaments. These results suggest that a seminal cell biological event in AD pathogenesis is acute, tau-dependent loss of microtubule integrity caused by exposure of neurons to readily diffusible Abeta.

    Funded by: NIA NIH HHS: AG02665, AG20465, F32 AG020465; NINDS NIH HHS: NS028785, NS051746, NS312230, R01 NS028785, R01 NS051746, R56 NS028785

    The Journal of cell biology 2006;175;4;541-6

  • PKA modulates GSK-3beta- and cdk5-catalyzed phosphorylation of tau in site- and kinase-specific manners.

    Liu F, Liang Z, Shi J, Yin D, El-Akkad E, Grundke-Iqbal I, Iqbal K and Gong CX

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA. feiliu63@hotmail.com

    Phosphorylation of tau protein is regulated by several kinases, especially glycogen synthase kinase 3beta (GSK-3beta), cyclin-dependent protein kinase 5 (cdk5) and cAMP-dependent protein kinase (PKA). Phosphorylation of tau by PKA primes it for phosphorylation by GSK-3beta, but the site-specific modulation of GSK-3beta-catalyzed tau phosphorylation by the prephosphorylation has not been well investigated. Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. These studies reveal the nature of the inter-regulation of tau phosphorylation by the three major tau kinases.

    Funded by: NIA NIH HHS: AG016760, AG019158, AG027429, R01 AG016760, R01 AG019158, R01 AG027429

    FEBS letters 2006;580;26;6269-74

  • Heterogeneity of ubiquitin pathology in frontotemporal lobar degeneration: classification and relation to clinical phenotype.

    Mackenzie IR, Baborie A, Pickering-Brown S, Du Plessis D, Jaros E, Perry RH, Neary D, Snowden JS and Mann DM

    Department of Pathology, Vancouver General Hospital, V5Z 1M9, Vancouver, BC, Canada.

    We have investigated the extent and pattern of immunostaining for ubiquitin protein (UBQ) in 60 patients with frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U), 37 of whom were ascertained in Manchester UK and 23 in Newcastle-Upon-Tyne, UK. There were three distinct histological patterns according to the form and distribution of the UBQ pathology. Histological type 1 was present in 19 patients (32%) and characterised by the presence of a moderate number, or numerous, UBQ immunoreactive neurites and intraneuronal cytoplasmic inclusions within layer II of the frontal and temporal cerebral cortex, and cytoplasmic inclusions within granule cells of the dentate gyrus; neuronal intranuclear inclusions (NII) of a "cat's eye" or "lentiform" appearance were present in 17 of these patients. In histological type 2 (16 patients, 27%), UBQ neurites were predominantly, or exclusively, present with few intraneuronal cytoplasmic inclusions within layer II of the cerebral cortex, while in histological type 3 (25 patients, 42%), UBQ intraneuronal cytoplasmic inclusions either within the cortical layer II or in the granule cells of the dentate gyrus, with few or no UBQ neurites, were seen. In neither of these latter two groups were NII present. The influence of histological type on clinical phenotype was highly significant with type 1 histology being associated clinically with cases of frontotemporal dementia (FTD) or progressive non-fluent aphasia (PNFA), type 2 histology with semantic dementia (SD), and type 3 histology with FTD, or FTD and motor neurone disease (MND).

    Funded by: Medical Research Council: G0400356

    Acta neuropathologica 2006;112;5;539-49

  • Regulation of phosphorylation of tau by cyclin-dependent kinase 5 and glycogen synthase kinase-3 at substrate level.

    Sengupta A, Novak M, Grundke-Iqbal I and Iqbal K

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314-6399, USA.

    Microtubule associated protein tau, which is expressed in six alternatively spliced molecular isoforms in human brain, is abnormally hyperphosphorylated in Alzheimer disease and related tauopathies. Here, we show (i) that GSK-3alpha and neither GSK-3beta nor cdk5 can phosphorylate tau at Ser262 and phosphorylation at Ser235 by cdk5 primes phosphorylation at Thr231 by GSK-3alpha/beta; (ii) that tau isoforms with two N-terminal inserts (tau4L, tau3L) are phosphorylated by cdk5 plus GSK-3 at Thr231 markedly more than isoforms lacking these inserts (tau4, tau3); and (iii) that Thr231 is phosphorylated approximately 50% more in free tau than in microtubule-bound tau, and the phosphorylation at this site results in the dissociation of tau from microtubules. These findings suggest that the phosphorylation of tau at Thr231 and Ser262 by cdk5 plus GSK-3, which inhibits its normal biological activity, is regulated both by its amino terminal inserts and its physical state.

    Funded by: NIA NIH HHS: AG019158, AG05892, AG08776, R01 AG019158, R01 AG019158-08; NINDS NIH HHS: NS18105

    FEBS letters 2006;580;25;5925-33

  • N-terminal fragments of tau inhibit full-length tau polymerization in vitro.

    Horowitz PM, LaPointe N, Guillozet-Bongaarts AL, Berry RW and Binder LI

    Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, Illinois 60611-3008, USA. p-horowitz@md.northwestern.edu

    The polymerization of the microtubule-associated protein, tau, into insoluble filaments is a common thread in Alzheimer's disease and in a variety of frontotemporal dementias. The conformational change required for tau to transition from an extended monomeric state to a filamentous state with a high beta-sheet content involves the extreme N-terminus coming into contact with distal portions of the molecule; however, these exact interactions are incompletely understood. Here we report that a construct representing amino acids 1-196 (Tau196), which itself does not polymerize, inhibits polymerization of full-length tau (hTau40) in vitro. In addition, we trace the inhibitory effect of Tau196 to amino acids 18-42 of the construct. We also provide evidence that the N-terminal tau fragments require a specific C-terminal region of tau (residues 392-421) to exert their inhibitory effect. The fragments are most effective at inhibiting polymerization when present during the initial 5 min; they remain in the soluble fraction of the polymerization reaction, and they increase the amount of soluble hTau40. The fragments also reduce the number and average length of filaments that are formed. Taken together, these results suggest that the N-terminal tau fragments inhibit hTau40 polymerization by interacting with a specific C-terminal sequence, thereby stabilizing a soluble conformation of tau.

    Funded by: NIA NIH HHS: AG09466, AG14453; NINDS NIH HHS: NS049834, NS49760

    Biochemistry 2006;45;42;12859-66

  • Structural impact of heparin binding to full-length Tau as studied by NMR spectroscopy.

    Sibille N, Sillen A, Leroy A, Wieruszeski JM, Mulloy B, Landrieu I and Lippens G

    CNRS UMR 8576, Unité de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille 1, 59655, Villeneuve d'Ascq Cedex, France.

    The neuronal Tau protein is involved in stabilizing microtubules but is also the major component of the paired helical filaments (PHFs), the intracellular aggregates that characterize Alzheimer's disease (AD) in neurons. In vitro, Tau can be induced to form AD-like aggregates by adding polyanions such as heparin. While previous studies have identified the microtubule binding repeats (MTBRs) as the major player in Tau aggregation, the fact that the full-length protein does not aggregate by itself indicates the presence of inhibitory factors. Charge and conformational changes are of uttermost importance near the second (R2) and third (R3) MTBR that are thought to be involved directly in the nucleation of the aggregation. Recently, the positively charged regions flanking the MTBR were proposed to inhibit PHF assembly, where hyperphosphorylation neutralizes these basic inhibitory domains, enabling Tau-Tau interactions. Here we present results of an NMR study on the interaction between intact full-length Tau and small heparin fragments of well-defined size, under conditions where no aggregation occurs. Our findings reveal (i) micromolar affinity of heparin to residues in R2 and R3, (ii) two zones of strong interaction within the positively charged inhibitory regions flanking the MTBR, and (iii) another interaction site upstream of the two inserts encoded by exons 2 and 3. Three-dimensional heteronuclear NMR experiments demonstrate that the interaction with heparin induces beta-strand structure in several regions of Tau that might act as nucleation sites for its aggregation but indicate as well alpha-helical structure in regions outside the core of PHF. In the PHF, the residues outside of the core maintain sufficient mobility for NMR detection and recover their unbound chemical shift values after an overnight incubation at 37 degrees C with heparin. Heparin thus becomes integrated into the rigid core region of the PHF, probably providing the charge compensation for the lysine-rich stretches that form upon the in-register, parallel stacking of the repeat regions.

    Biochemistry 2006;45;41;12560-72

  • Untangling the tau gene association with neurodegenerative disorders.

    Pittman AM, Fung HC and de Silva R

    Reta Lila Weston Institute of Neurological Studies, University College London, 1, Wakefield Street, London WC1N 1PJ, UK.

    Pathological tau protein inclusions have long been recognized to define the diverse range of neurodegenerative disorders called the tauopathies, which include Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and frontotemporal lobar degeneration. Mutations in the tau gene, MAPT, cause familial frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), and common variation in MAPT is strongly associated with the risk of PSP, corticobasal degeneration and, to a lesser extent, AD and Parkinson's disease (PD), implicating the involvement of tau in common neurodegenerative pathway(s). This review will discuss recent work towards the unravelling of the functional basis of this MAPT gene association. The region of chromosome 17q21 containing MAPT locus is characterized by the complex genomic architecture, including a large inversion that leads to a bipartite haplotype architecture, an inversion-mediated deletion and multiplications resulting from non-allelic homologous recombination between the MAPT family of low-copy repeats.

    Funded by: Medical Research Council: G0501560, G0501560(76517)

    Human molecular genetics 2006;15 Spec No 2;R188-95

  • Study on interaction between microtubule associated protein tau and prion protein.

    Han J, Zhang J, Yao H, Wang X, Li F, Chen L, Gao C, Gao J, Nie K, Zhou W and Dong X

    State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.

    Microtubule-associated protein tau is considered to play roles in many neurodegenerative diseases including some transmissible spongiform encephalopathies. To address the possible molecular linkage of prion protein (PrP) and tau, a GST-fusion segment of human tau covering the three-repeat region and various PrP segments was used in the tests of GST pull-down and immunoprecipitation. We found tau protein interacted with various style prion proteins such as native prion protein (PrPc) or protease-resistant isoform (PrPSc). Co-localization signals of tau and PrP were found in the CHO cell tranfected with both PrP and tau gene. The domain of interaction with tau was located at N-terminal of PrP (residues 23 to 91). The evidence of molecular interactions between PrP and tau protein highlights a potential role of tau in the biological function of PrP and the pathogenesis of TSEs.

    Science in China. Series C, Life sciences 2006;49;5;473-9

  • Tauopathies: classification and clinical update on neurodegenerative diseases associated with microtubule-associated protein tau.

    Williams DR

    Reta Lila Weston Institute of Neurological Studies, University College London, London, UK. drdavew@bigpond.com

    The majority of neurodegenerative diseases are characterized by the deposition of insoluble protein in cells of the neuromuscular system. Advances in molecular neuropathology have allowed a classification system of neurodegenerative diseases based on this protein accumulation. Microtubule-associated tau is one protein that has important functions in healthy neurons, but forms insoluble deposits in diseases now known collectively as tauopathies. Tauopathies encompass more than 20 clinicopathological entities, including Alzheimer's disease, the most common tauopathy, progressive supranuclear palsy, Pick's disease, corticobasal degeneration and post-encephalitic parkinsonism. There are important clinical, pathological, biochemical and genetic similarities in the range of these diseases and they have helped to advance our understanding of the aetiological factors that initiate neurodegeneration and tau accumulation. This review examines the important clinical features of the most prevalent tauopathies and the molecular and pathological features that underpin the classification system.

    Internal medicine journal 2006;36;10;652-60

  • Transgenic mouse models for Alzheimer's disease: the role of GSK-3B in combined amyloid and tau-pathology.

    Muyllaert D, Terwel D, Borghgraef P, Devijver H, Dewachter I and Van Leuven F

    Experimental Genetics Group, LEGT-EGG, KULeuven, Campus Gasthuisberg, Leuven, Belgium.

    Describing and understanding the pathological processes which devastate the brain of Alzheimer's disease (AD) patients remains a major target for experimental biology. We approached this problem by generating different types of single and double transgenic mice that develop pathological hallmarks of AD. In APP-V717 mice, the progression from intracellular amyloid to diffuse and senile plaques with vascular deposits, is preceded by early defects in cognition and LTP. In Tau-P301L mice, the morbid tauopathy with intracellular filaments, cause mortality before age 1 year. Ageing APP-V717IxTau-P301L double tg mice (14-17 months) have combined AD-like pathology in hippocampus and cortex consisting of amyloid plaques and neurofibrillary tangles. Remarkably, while Tau-P301L mice die before age 1 year, the APP-V717IxTau-P301L double tg mice survive much longer, which correlates with alleviation of tauopathy in hindbrain, despite aggravation in forebrain. This hypothesis is corroborated in Tau-P301LxGSK-3B double transgenic mice, which have also an extended lifespan relative to Tau-P301L mice, that correlates with reduction of brainstem tauopathy. At the same time, Tau-P301LxGSK-3B mice have dramatic forebrain tauopathy, with "tangles in almost all neurons", although without hyper-phosphorylation of Tau. The data corroborate the hypothesis that GSK-3B is the missing link between the amyloid and tau-pathology, and position GSK-3B as prominent player in the pathogenesis in AD.

    Revue neurologique 2006;162;10;903-7

  • Correlation of tau gene polymorphism with age at onset of Parkinson's disease.

    Kobayashi H, Ujike H, Hasegawa J, Yamamoto M, Kanzaki A and Sora I

    Department of Psychobiology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.

    Parkinson's disease (PD) is a neurodegenerative disease and its prevalence increases with age. The microtubule-associated protein tau (MAPT) is thought to be implicated in the pathogenesis of PD. Association of the MAPT H1 haplotype with PD in Caucasians has been extensively studied, however, the results were inconsistent. In this study, we investigated whether MAPT gene variants contribute to the pathogenesis process including the age at onset in Japanese PD. Promoter region of MAPT gene was analyzed to find polymorphisms in Japanese population. Two single nucleotide polymorphisms (SNPs), C-639T and Del-568TIns, in promoter region were found. C-639T was novel. Unlike Caucasians, the -226C and -45A alleles consisting of the H1 haplotype were monomorphic in Japanese population. Association analysis was performed using 240 PD and 191 controls in these SNPs. No significant association was observed between these SNPs and PD. Haplotype analysis also showed no significant association (P=0.72). However, the age at onset showed significant correlation with the genotypes of Del-568TIns in PD samples when analyzed by Kendall rank correlation test (Kendall tau=-0.098, P=0.0243). These results suggested that MAPT gene variants may modify the pathogenesis process of PD.

    Neuroscience letters 2006;405;3;202-6

  • Folding of the repeat domain of tau upon binding to lipid surfaces.

    Barré P and Eliezer D

    Department of Biochemistry and Program in Structural Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.

    The microtubule-associated protein tau is impacted in neurodegeneration and dementia through its deposition in the form of paired helical filaments in Alzheimer's disease neurofibrillary tangles and through mutations linking it to the autosomal dominant disorder frontotemporal dementia with Parkinsonism. When isolated in solution tau is intrinsically unstructured and does not fold, while the conformation of the protein in the microtubule-bound state remains uncharacterized. Here we show that the repeat region of tau, which has been reported both to mediate tau microtubule interactions and to constitute the proteolysis-resistant core of disease-associated tau aggregates, associates with lipid micelles and vesicles and folds into an ordered structure upon doing so. In addition to providing the first structural insights into a folded state of tau, our results support a role for lipid membranes in mediating tau function and tau pathology.

    Funded by: NIA NIH HHS: AG025440, R01 AG019391, R01 AG019391-06, R01 AG025440, R01 AG025440-01A1, R37 AG019391; NIGMS NIH HHS: GM66354

    Journal of molecular biology 2006;362;2;312-26

  • Effect of MAPT and APOE on prognosis of progressive supranuclear palsy.

    Baba Y, Putzke JD, Tsuboi Y, Josephs KA, Thomas N, Wszolek ZK and Dickson DW

    Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA.

    To assess genetic influence on the clinical presentation of progressive supranuclear palsy (PSP), the genetic effect on disease course was examined for variants in the tau gene (MAPT) and the gene for apolipoprotein E (APOE) in 58 cases of pathologically confirmed PSP. Clinical indicators of disease course included age at symptomatic onset (AAO), age at death (AAD), and disease duration (DD) and the genetic effects examined included MAPT haplotypes and APOE genotypes. From linear regression analysis, the MAPT H1/H1 genotype was associated with significantly earlier AAO (P=0.038). The MAPT genotype did not significantly influence DD or AAD. The APOE epsilon4 allele did not significantly influence AAO, AAD, or DD. Male sex was a predictor for earlier AAO (P=0.015). The interaction between MAPT and APOE was not significant for AAD and DD, but a significant negative coefficient was found for AAO suggesting their combination does not have an additive effect. These results support the assertion that the H1/H1 genotype may contribute to the earlier occurrence of clinical symptoms.

    Funded by: NIA NIH HHS: P01-AG03949, P01-AG14449, P01-AG17216, P50-AG16574; NINDS NIH HHS: P50-NS40256

    Neuroscience letters 2006;405;1-2;116-9

  • Extracellular tau is toxic to neuronal cells.

    Gómez-Ramos A, Díaz-Hernández M, Cuadros R, Hernández F and Avila J

    Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Campus de Cantoblanco, Universidad Autónoma de Madrid, 28049-Madrid, Spain.

    The degeneration of neurons in disorders such as Alzheimer's disease has an immediate consequence, the release of intracellular proteins into the extracellular space. One of these proteins, tau, has proven to be toxic when added to cultured neuronal cells. This toxicity varies according to the degree of protein aggregation. The addition of tau to cultured neuroblastoma cells provoked an increase in the levels of intracellular calcium, which is followed by cell death. We suggest that this phenomenon may be mediated by the interaction of tau with muscarinic receptors, which promotes the liberation of calcium from intracellular stores.

    FEBS letters 2006;580;20;4842-50

  • Microtubule binding and clustering of human Tau-4R and Tau-P301L proteins isolated from yeast deficient in orthologues of glycogen synthase kinase-3beta or cdk5.

    Vandebroek T, Terwel D, Vanhelmont T, Gysemans M, Van Haesendonck C, Engelborghs Y, Winderickx J and Van Leuven F

    Experimental Genetics Group, KULeuven, B-3000 Leuven, Belgium.

    Phosphorylation of Tau protein and binding to microtubules is complex in neurons and was therefore studied in the less complicated model of humanized yeast. Human Tau was readily phosphorylated at pathological epitopes, but in opposite directions regulated by kinases Mds1 and Pho85, orthologues of glycogen synthase kinase-3beta and cdk5, respectively (1). We isolated recombinant Tau-4R and mutant Tau-P301L from wild type, Delta mds1 and Delta pho85 yeast strains and measured binding to Taxol-stabilized mammalian microtubules in relation to their phosphorylation patterns. Tau-4R isolated from yeast lacking mds1 was less phosphorylated and bound more to microtubules than Tau-4R isolated from wild type yeast. Paradoxically, phosphorylation of Tau-4R isolated from kinase Pho85-deficient yeast was dramatically increased resulting in very poor binding to microtubules. Dephosphorylation promoted binding to microtubules to uniform high levels, excluding other modifications. Isolated hyperphosphorylated, conformationally altered Tau-4R completely failed to bind microtubules. In parallel to Tau-4R, we expressed, isolated, and analyzed mutant Tau-P301L. Total dephosphorylated Tau-4R and Tau-P301L bound to microtubules very similarly. Surprisingly, Tau-P301L isolated from all yeast strains bound to microtubules more extensively than Tau-4R. Atomic force microscopy demonstrated, however, that the high apparent binding of Tau-P301L was due to aggregation on the microtubules, causing their deformation and bundling. Our data explain the pathological presence of granular Tau aggregates in neuronal processes in tauopathies.

    The Journal of biological chemistry 2006;281;35;25388-97

  • A new chromosome 17q21.31 microdeletion syndrome associated with a common inversion polymorphism.

    Koolen DA, Vissers LE, Pfundt R, de Leeuw N, Knight SJ, Regan R, Kooy RF, Reyniers E, Romano C, Fichera M, Schinzel A, Baumer A, Anderlid BM, Schoumans J, Knoers NV, van Kessel AG, Sistermans EA, Veltman JA, Brunner HG and de Vries BB

    Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands.

    Submicroscopic genomic copy number changes have been identified only recently as an important cause of mental retardation. We describe the detection of three interstitial, overlapping 17q21.31 microdeletions in a cohort of 1,200 mentally retarded individuals associated with a clearly recognizable clinical phenotype of mental retardation, hypotonia and a characteristic face. The deletions encompass the MAPT and CRHR1 genes and are associated with a common inversion polymorphism.

    Nature genetics 2006;38;9;999-1001

  • Association study of polymorphisms in LRP1, tau and 5-HTT genes and Alzheimer's disease in a sample of Colombian patients.

    Forero DA, Arboleda G, Yunis JJ, Pardo R and Arboleda H

    Grupo de Neurociencias, Facultad de Medicina e Instituto de Genética, Universidad Nacional de Colombia, Bogotá, Colombia.

    Analysis of genetic susceptibility factors for Alzheimer's disease (AD) in populations with different genetic and environmental background may be useful to understand AD etiology. There are few genetic association studies of AD in Latin America. In the present work, we analyzed polymorphisms in 3 candidate genes; the LDL receptor related protein-1, the microtubule-associated protein Tau and the serotonin transporter genes in a sample of 106 Colombian AD patients and 97 control subjects. We did not find a significant allelic or genotypic association with any of the three polymorphisms analyzed using different statistical analysis, including a neural network model or different sample stratifications. To date, APOE polymorphisms are the only genetic risk factors identified for AD in the Colombian population. It may be factible that future combination of high-throughput genotyping platforms and multivariate analysis models may lead to the identification of other genetic susceptibility factors for AD in the Colombian population.

    Journal of neural transmission (Vienna, Austria : 1996) 2006;113;9;1253-62

  • Microdeletion encompassing MAPT at chromosome 17q21.3 is associated with developmental delay and learning disability.

    Shaw-Smith C, Pittman AM, Willatt L, Martin H, Rickman L, Gribble S, Curley R, Cumming S, Dunn C, Kalaitzopoulos D, Porter K, Prigmore E, Krepischi-Santos AC, Varela MC, Koiffmann CP, Lees AJ, Rosenberg C, Firth HV, de Silva R and Carter NP

    University of Cambridge Department of Medical Genetics, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK. css@sanger.ac.uk

    Recently, the application of array-based comparative genomic hybridization (array CGH) has improved rates of detection of chromosomal imbalances in individuals with mental retardation and dysmorphic features. Here, we describe three individuals with learning disability and a heterozygous deletion at chromosome 17q21.3, detected in each case by array CGH. FISH analysis demonstrated that the deletions occurred as de novo events in each individual and were between 500 kb and 650 kb in size. A recently described 900-kb inversion that suppresses recombination between ancestral H1 and H2 haplotypes encompasses the deletion. We show that, in each trio, the parent of origin of the deleted chromosome 17 carries at least one H2 chromosome. This region of 17q21.3 shows complex genomic architecture with well-described low-copy repeats (LCRs). The orientation of LCRs flanking the deleted segment in inversion heterozygotes is likely to facilitate the generation of this microdeletion by means of non-allelic homologous recombination.

    Funded by: Medical Research Council: G0501560, G0501560(76517); Wellcome Trust

    Nature genetics 2006;38;9;1032-7

  • SRp54 (SFRS11), a regulator for tau exon 10 alternative splicing identified by an expression cloning strategy.

    Wu JY, Kar A, Kuo D, Yu B and Havlioglu N

    Northwestern University Feinberg School of Medicine, Center for Genetic Medicine, 303 E. Superior St., Lurie 6-117, Chicago, IL 60611, USA. jane-wu@northwestern.edu

    The tau gene encodes a microtubule-associated protein that is critical for neuronal survival and function. Splicing defects in the human tau gene lead to frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17), an autosomal dominant neurodegenerative disorder. Genetic mutations associated with FTDP-17 often affect tau exon 10 alternative splicing. To investigate mechanisms regulating tau exon 10 alternative splicing, we have developed a green fluorescent protein reporter for tau exon 10 skipping and an expression cloning strategy to identify splicing regulators. A role for SRp54 (also named SFRS11) as a tau exon 10 splicing repressor has been uncovered using this strategy. The overexpression of SRp54 suppresses tau exon 10 inclusion. RNA interference-mediated knock-down of SRp54 increases exon 10 inclusion. SRp54 interacts with a purine-rich element in exon 10 and antagonizes Tra2beta, an SR-domain-containing protein that enhances exon 10 inclusion. Deletion of this exonic element eliminates the activity of SRp54 in suppressing exon 10 inclusion. Our data support a role of SRp54 in regulating tau exon 10 splicing. These experiments also establish a generally useful approach for identifying trans-acting regulators of alternative splicing by expression cloning.

    Funded by: NIA NIH HHS: AG 17518; NIGMS NIH HHS: GM 07967

    Molecular and cellular biology 2006;26;18;6739-47

  • RBM4 interacts with an intronic element and stimulates tau exon 10 inclusion.

    Kar A, Havlioglu N, Tarn WY and Wu JY

    Department of Neurology, Lurie Comprehensive Cancer Center, Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611.

    Tau protein, which binds to and stabilizes microtubules, is critical for neuronal survival and function. In the human brain, tau pre-mRNA splicing is regulated to maintain a delicate balance of exon 10-containing and exon 10-skipping isoforms. Splicing mutations affecting tau exon 10 alternative splicing lead to tauopathies, a group of neurodegenerative disorders including dementia. Molecular mechanisms regulating tau alternative splicing remain to be elucidated. In this study, we have developed an expression cloning strategy to identify splicing factors that stimulate tau exon 10 inclusion. Using this expression cloning approach, we have identified a previously unknown tau exon 10 splicing regulator, RBM4 (RNA binding motif protein 4). In cells transfected with a tau minigene, RBM4 overexpression leads to an increased inclusion of exon 10, whereas RBM4 down-regulation decreases exon 10 inclusion. The activity of RBM4 in stimulating tau exon 10 inclusion is abolished by mutations in its RNA-binding domain. A putative intronic splicing enhancer located in intron 10 of the tau gene is required for the splicing stimulatory activity of RBM4. Immunohistological analyses reveal that RBM4 is expressed in the human brain regions affected in tauopathy, including the hippocampus and frontal cortex. Our study demonstrates that RBM4 is involved in tau exon 10 alternative splicing. Our work also suggests that down-regulating tau exon 10 splicing activators, such as RBM4, may be of therapeutic potential in tauopathies involving excessive tau exon 10 inclusion.

    Funded by: NCI NIH HHS: R01 CA114197-01A2; NEI NIH HHS: EY014576, R01 EY014576-03; NIA NIH HHS: AG17518; NIGMS NIH HHS: GM070967, R01 GM070967-02

    The Journal of biological chemistry 2006;281;34;24479-88

  • Cell type-specific processing of human Tau proteins in Drosophila.

    Grammenoudi S, Kosmidis S and Skoulakis EM

    Institute of Molecular Biology and Genetics, Biomedical Sciences Research Centre "Alexander Fleming", 34 Fleming Street, Vari 16672, Greece.

    Accumulation of hyperphosphorylated Tau is associated with a number of neurodegenerative diseases collectively known as tauopathies. Differences in clinical and cognitive profiles among them suggest differential sensitivity of neuronal populations to Tau levels, phosphorylation and mutations. We used tissue specific expression of wild type and mutant human tau transgenes to demonstrate differential phosphorylation and stability in a cell type-specific manner, which includes different neuronal types and does not correlate with the level of accumulated protein. Rather, they likely reflect the spatial distribution or regulation of Tau-targeting kinases and phosphatases.

    FEBS letters 2006;580;19;4602-6

  • Neighbored phosphorylation sites as PHF-tau specific markers in Alzheimer's disease.

    Singer D, Lehmann J, Hanisch K, Härtig W and Hoffmann R

    Bioanalytics, Center for Biotechnology and Biomedicine (BBZ), Faculty of Chemistry and Mineralogy, University of Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany.

    Neurofibrillary tangles, which represent a major pathological hallmark in Alzheimer's disease (AD), are deposits of the hyperphosphorylated microtubule-associated tau protein (PHF-tau). However, a link between the phosphorylation pattern and the cause or the progress of AD is still missing. The work reported here focused on PHF-tau specific local phosphorylation patterns at Thr212/Ser214 and Thr231/Ser235 using monoclonal antibodies (mAb) generated against correspondingly modified peptides. The binding motifs of the obtained six mAbs were characterized with non-, mono-, and double-phosphorylated peptides as well as terminally shortened sequences. Five mAbs stained neurofibrillary tangles, neuritic plaques, and neuropil threads from autoptic brains of AD cases. Four mAbs recognized PHF-tau without significant cross-reactivity towards normal human tau, bovine tau, and dephosphorylated PHF-tau in ELISA and Western blot analysis. Thus, double phosphorylation is sufficient to distinguish PHF-tau from all other tau versions and there is no need to postulate any PHF-tau specific conformation for this region.

    Biochemical and biophysical research communications 2006;346;3;819-28

  • Alzheimer's disease-like tau neuropathology leads to memory deficits and loss of functional synapses in a novel mutated tau transgenic mouse without any motor deficits.

    Schindowski K, Bretteville A, Leroy K, Bégard S, Brion JP, Hamdane M and Buée L

    INSERM U815, Place de Verdun, 59045 Lille Cedex, France. katharina.schindowski@lille.inserm.fr

    Tau transgenic mice are valuable models to investigate the role of tau protein in Alzheimer's disease and other tauopathies. However, motor dysfunction and dystonic posture interfering with behavioral testing are the most common undesirable effects of tau transgenic mice. Therefore, we have generated a novel mouse model (THY-Tau22) that expresses human 4-repeat tau mutated at sites G272V and P301S under a Thy1.2-promotor, displaying tau pathology in the absence of any motor dysfunction. THY-Tau22 shows hyperphosphorylation of tau on several Alzheimer's disease-relevant tau epitopes (AT8, AT100, AT180, AT270, 12E8, tau-pSer396, and AP422), neurofibrillary tangle-like inclusions (Gallyas and MC1-positive) with rare ghost tangles and PHF-like filaments, as well as mild astrogliosis. These mice also display deficits in hippocampal synaptic transmission and impaired behavior characterized by increased anxiety, delayed learning from 3 months, and reduced spatial memory at 10 months. There are no signs of motor deficits or changes in motor activity at any age investigated. This mouse model therefore displays the main features of tau pathology and several of the pathophysiological disturbances observed during neurofibrillary degeneration. This model will serve as an experimental tool in future studies to investigate mechanisms underlying cognitive deficits during pathogenic tau aggregation.

    The American journal of pathology 2006;169;2;599-616

  • Expression of a truncated tau protein induces oxidative stress in a rodent model of tauopathy.

    Cente M, Filipcik P, Pevalova M and Novak M

    Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence, Dubravska cesta 9, 84510 Bratislava, Slovakia.

    Truncation of tau protein and oxidative stress have been implicated as important pathogenetic events in tauopathies including Alzheimer's disease (AD). We have generated a transgenic rat model that expresses a human truncated tau protein analogous to a variant form derived from sporadic AD. We employed this model to investigate the relationship between tau protein truncation and oxidative stress. We have found that rat cortical neurons (derived from transgenic animals) that had been cultured in vitro for 16 days showed an increased accumulation of reactive oxygen species (up to 1.4-fold increase; P < 0.01) when compared to neurons derived from nontransgenic control animals. Transgene-expressing neurons treated with inducers of oxidative stress, such as glucose oxidase (GO) and buthionine sulfoximine (BSO), displayed dramatically reduced survival (31.4 +/- 3.3 and 24.9 +/- 3.6%, respectively; both P < 0.001) compared to neurons from control animals (79.9 +/- 7.1%, survival following treatment with GO and to 98.2 +/- 3.8%, survival following treatment with BSO). The number of mitochondria in processes of neurons from transgenic animals was decreased by about one-third from that present in neurons from control animals. The results reveal that expression of a human truncated variant form of tau protein leads to the accumulation of reactive oxygen species and sensitizes rat cortical neurons to cell death induced by oxidative stress. This indicates that truncation of tau may precede oxidative stress in the pathogenesis of neurodegenerative diseases such as AD and other tauopathies. These findings may have implications for therapeutic strategies aiming at prevention of neurofibrillary degeneration and cognitive decline, and identify potential new targets for drug development.

    The European journal of neuroscience 2006;24;4;1085-90

  • Rimmed vacuoles with beta-amyloid and tau protein deposits in the muscle of children with hereditary myopathy.

    Fidziańska A and Glinka Z

    Neuromuscular Unit MRC, Polish Academy of Science, Pawińskiego 5, 02-106, Warsaw, Poland. neurmyol@cmdik.pan.pl

    We investigated whether beta-amyloid and tau protein are involved in the formation of inclusion body myositis (IBM)-like inclusions found in children with rimmed vacuoles and congenitally affected muscles. We immunostained muscle biopsy specimens from four children and one 18-year-old boy with congenital myopathy containing rimmed vacuoles and IBM-like inclusions with antibodies against beta-amyloid, tau protein and ubiquitin. Focal accumulations of both beta-amyloid and phosphorylated tau coexisted with tubulofilamentous structures in all cases. Our studies demonstrate for the first time that the full morphological phenotype of IBM including beta-amyloid and tau protein deposits may also develop in children, and that congenital, probably genetic, muscle defects may lead to abnormal protein aggregation in IBM-like inclusions.

    Acta neuropathologica 2006;112;2;185-93

  • Site-specific phosphorylation and caspase cleavage differentially impact tau-microtubule interactions and tau aggregation.

    Ding H, Matthews TA and Johnson GV

    Department of Psychiatry, University of Alabama, Birmingham, Alabama 35294-0017, USA.

    The microtubule-associated protein tau is hyperphosphorylated and forms neurofibrillary tangles in Alzheimer disease. Additionally caspase-cleaved tau is present in Alzheimer disease brains co-localized with fibrillar tau pathologies. To further understand the role of site-specific phosphorylation and caspase cleavage of tau in regulating its function, constructs of full-length tau (T4) or tau truncated at Asp421 (T4C3) to mimic caspase-3 cleavage with and without site-directed mutations that mimic phosphorylation at Thr231/Ser235, Ser396/Ser404, or at all four sites (Thr231/Ser235/Ser396/Ser404) were made and expressed in cells. Pseudophosphorylation of T4, but not T4C3, at either Thr231/Ser235 or Ser396/Ser404 increased its phosphorylation at Ser262 and Ser199. Pseudophosphorylation at Thr231/Ser235 impaired the microtubule binding of both T4 and T4C3. In contrast, pseudophosphorylation at Ser396/Ser404 only affected microtubule binding of T4C3 but did make T4 less soluble and more aggregated, which is consistent with the previous finding (Abraha, A., Ghoshal, N., Gamblin, T. C., Cryns, V., Berry, R. W., Kuret, J., and Binder, L. I. (2000) J. Cell Sci. 113, 3737-3745) that pseudophosphorylation at Ser396/Ser404 enhances tau polymerization in vitro. In situ T4C3 was more prevalent in the cytoskeletal and microtubule-associated fractions compared with T4, whereas purified recombinant T4 bound microtubules with higher affinity than did T4C3 in an in vitro assay. These data indicate the importance of cellular factors in regulating tau-microtubule interactions and that, in the cells, phosphorylation of T4 might impair its microtubule binding ability more than caspase cleavage. Treatment of cells with nocodazole revealed that pseudophosphorylation of T4 at both Thr231/Ser235 and Ser396/Ser404 diminished the ability of tau to protect against microtubule depolymerization, whereas with T4C3 only pseudophosphorylation at Ser396/Ser404 attenuated the ability of tau to stabilize the microtubules. These results show that site-specific phosphorylation and caspase cleavage of tau differentially affect the ability of tau to bind and stabilize microtubules and facilitate tau self-association.

    Funded by: NINDS NIH HHS: NS051279

    The Journal of biological chemistry 2006;281;28;19107-14

  • Role of protein phosphatase 2A in the regulation of endothelial cell cytoskeleton structure.

    Tar K, Csortos C, Czikora I, Olah G, Ma SF, Wadgaonkar R, Gergely P, Garcia JG and Verin AD

    Department of Medicine, Division of Biological Sciences, The University of Chicago, Chicago, Illinois, USA.

    Our recently published data suggested the involvement of protein phosphatase 2A (PP2A) in endothelial cell (EC) barrier regulation (Tar et al. [2004] J Cell Biochem 92:534-546). In order to further elucidate the role of PP2A in the regulation of EC cytoskeleton and permeability, PP2A catalytic (PP2Ac) and A regulatory (PP2Aa) subunits were cloned and human pulmonary arterial EC (HPAEC) were transfected with PP2A mammalian expression constructs or infected with PP2A recombinant adenoviruses. Immunostaining of PP2Ac or of PP2Aa + c overexpressing HPAEC indicated actin cytoskeleton rearrangement. PP2A overexpression hindered or at least dramatically reduced thrombin- or nocodazole-induced F-actin stress fiber formation and microtubule (MT) dissolution. Accordingly, it also attenuated thrombin- or nocodazole-induced decrease in transendothelial electrical resistance indicative of barrier protection. Inhibition of PP2A by okadaic acid abolished its effect on agonist-induced changes in EC cytoskeleton; this indicates a critical role of PP2A activity in EC cytoskeletal maintenance. The overexpression of PP2A significantly attenuated thrombin- or nocodazole-induced phosphorylation of HSP27 and tau, two cytoskeletal proteins, which potentially could be involved in agonist-induced cytoskeletal rearrangement and in the increase of permeability. PP2A-mediated dephosphorylation of HSP27 and tau correlated with PP2A-induced preservation of EC cytoskeleton and barrier maintenance. Collectively, our observations clearly demonstrate the crucial role of PP2A in EC barrier protection.

    Funded by: NHLBI NIH HHS: HL58064, HL67307, HL68062

    Journal of cellular biochemistry 2006;98;4;931-53

  • Association of the Tau haplotype with Parkinson's disease in the Greek population.

    Fidani L, Kalinderi K, Bostantjopoulou S, Clarimon J, Goulas A, Katsarou Z, Hardy J and Kotsis A

    Department of General Biology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. lfidani@med.auth.gr

    We compared the distribution of the Tau H1 haplotype and related subhaplotypes in a group of clinically diagnosed Parkinson's disease patients (n = 133) and in control individuals (n = 113) from northern Greece. We were able to detect a statistically significant overrepresentation of the H1H1 genotype in our patient group (OR for H1H1 vs. H1H2 and H2H2: 1.73; 95% CI: 1.03-2.90; P = 0.037). The H1 subhaplotype significantly associated with the disease in our population was different from the one previously reported for a Norwegian population, suggesting that the nature of the association of Tau with Parkinson's disease is influenced by ethnic variation.

    Funded by: Medical Research Council: G0701075; Parkinson's UK: G-0907

    Movement disorders : official journal of the Movement Disorder Society 2006;21;7;1036-9

  • High throughput SNP and expression analyses of candidate genes for non-syndromic oral clefts.

    Park JW, Cai J, McIntosh I, Jabs EW, Fallin MD, Ingersoll R, Hetmanski JB, Vekemans M, Attie-Bitach T, Lovett M, Scott AF and Beaty TH

    Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.

    Background: Recent work suggests that multiple genes and several environmental risk factors influence risk for non-syndromic oral clefts, one of the most common birth defects in humans. Advances in high-throughput genotyping technology now make it possible to test multiple markers in many candidate genes simultaneously.

    Methods: We present findings from family based association tests of single nucleotide polymorphism (SNP) markers in 64 candidate genes genotyped using the BeadArray approach in 58 case-parent trios from Maryland (USA) to illustrate how multiple markers in multiple genes can be analysed. To assess whether these genes were expressed in human craniofacial structures relevant to palate and lip development, we also analysed data from the Craniofacial and Oral Gene Expression Network (COGENE) consortium, and searched public databases for expression profiles of these genes.

    Results: Thirteen candidate genes showed significant evidence of linkage in the presence of disequilibrium, and ten of these were found to be expressed in relevant embryonic tissues: SP100, MLPH, HDAC4, LEF1, C6orf105, CD44, ALX4, ZNF202, CRHR1, and MAPT. Three other genes showing statistical evidence (ADH1C, SCN3B, and IMP5) were not expressed in the embryonic tissues examined here.

    Conclusions: This approach demonstrates how statistical evidence on large numbers of SNP markers typed in case-parent trios can be combined with expression data to identify candidate genes for complex disorders. Many of the genes reported here have not been previously studied as candidates for oral clefts and warrant further investigation.

    Funded by: NIDCR NIH HHS: N01-DE92630, P60-DE13078, R01-DE014581

    Journal of medical genetics 2006;43;7;598-608

  • Impaired spatial reference memory and increased exploratory behavior in P301L tau transgenic mice.

    Pennanen L, Wolfer DP, Nitsch RM and Götz J

    Division of Psychiatry Research, University of Zurich, Zurich, Switzerland.

    The neuropathological hallmark shared between Alzheimer's disease (AD) and familial frontotemporal dementia (FTDP-17) are neurofibrillary tangles (NFT) which are composed of filamentous aggregates of the microtubule-associated protein tau. Their formation has been reproduced in transgenic mice, which express the FTDP-17-associated mutation P301L of tau. In these mice, tau aggregates are found in many brain areas including the hippocampus and the amygdala, both of which are characterized by NFT formation in AD. Previous studies using an amygdala-specific test battery revealed an increase in exploratory behavior and an accelerated extinction of conditioned taste aversion in these mice. Here, we assessed P301L mice in behavioral tests known to depend on an intact hippocampus. Morris water maze and Y-maze revealed intact spatial working memory but impairment in spatial reference memory at 6 and 11 months of age. In addition, a modest disinhibition of exploratory behavior at 6 months of age was confirmed in the open field and the elevated O-maze and was more pronounced during aging.

    Genes, brain, and behavior 2006;5;5;369-79

  • In vitro tau fibrillization: mapping protein regions.

    Santa-María I, Pérez M, Hernández F, Muñoz V, Moreno FJ and Avila J

    Centro de Biología Molecular "Severo Ochoa" CSIC/UAM, Fac. Ciencias, Facultad de Ciencias, Campus de Cantoblanco, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.

    We have investigated the propensity to form fibrillar aggregates of a variety of fragments and variants of the tau protein under the influence of a tau fibrillization inducer: coenzyme Q(0). To better identify fibrillization hotspots, we compare the polymerization propensity of tau fragments containing the sequence of putative hotspots with that of tau variants with that same sequence deleted. We also investigate the effects of biologically occurring modifications such as phosphorylation and deamidation. We found that residues 305 to 335 are essential for in vitro tau fibrillization. Residues 306 to 311 facilitate in vitro assembly, but are not sufficient to mimic the in vivo fibrillization of tau. Furthermore, the propensity of the 306-311 sequence to form fibrils is highly decreased by chemical modifications of tyrosine 310 that are commonly found in vivo.

    Biochimica et biophysica acta 2006;1762;7;683-92

  • Inhibition of APP trafficking by tau protein does not increase the generation of amyloid-beta peptides.

    Goldsbury C, Mocanu MM, Thies E, Kaether C, Haass C, Keller P, Biernat J, Mandelkow E and Mandelkow EM

    Max Planck Unit for Structural Molecular Biology, c/o DESY, Notkestrasse 85, 22607 Hamburg, Germany.

    Amyloid-beta, a peptide derived from the precursor protein APP, accumulates in the brain and contributes to the neuropathology of Alzheimer's disease. Increased generation of amyloid-beta might be caused by axonal transport inhibition, via increased dwell time of APP vesicles and thereby higher probability of APP cleavage by secretase enzymes residing on the same vesicles. We tested this hypothesis using a neuronal cell culture model of inhibited axonal transport and by imaging vesicular transport of fluorescently tagged APP and beta-secretase (BACE1). Microtubule-associated tau protein blocks vesicle traffic by inhibiting the access of motor proteins to the microtubule tracks. In neurons co-transfected with CFP-tau, APP-YFP traffic into distal neurites was strongly reduced. However, this did not increase amyloid-beta levels. In singly transfected axons, APP-YFP was transported in large tubules and vesicles moving very fast (on average 3 microm/s) and with high fluxes in the anterograde direction (on average 8.4 vesicles/min). By contrast, BACE1-CFP movement was in smaller tubules and vesicles that were almost 2x slower (on average 1.6 microm/s) with approximately 18x lower fluxes (on average 0.5 vesicles/min). Two-colour microscopy of co-transfected axons confirmed that the two proteins were sorted into distinct carriers. The results do not support the above hypothesis. Instead, they indicate that APP is transported on vesicles distinct from the secretase components and that amyloid-beta is not generated in transit when transport is blocked by tau.

    Traffic (Copenhagen, Denmark) 2006;7;7;873-88

  • Deletion of the ubiquitin ligase CHIP leads to the accumulation, but not the aggregation, of both endogenous phospho- and caspase-3-cleaved tau species.

    Dickey CA, Yue M, Lin WL, Dickson DW, Dunmore JH, Lee WC, Zehr C, West G, Cao S, Clark AM, Caldwell GA, Caldwell KA, Eckman C, Patterson C, Hutton M and Petrucelli L

    Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA.

    Accumulation of the microtubule-associated protein tau into neurofibrillary lesions is a pathological consequence of several neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Hereditary mutations in the MAPT gene were shown to promote the formation of structurally distinct tau aggregates in patients that had a parkinsonian-like clinical presentation. Whether tau aggregates themselves or the soluble intermediate species that precede their aggregation are neurotoxic entities in these disorders has yet to be resolved; however, recent in vivo evidence supports the latter. We hypothesized that depletion of CHIP, a tau ubiquitin ligase, would lead to an increase in abnormal tau. Here, we show that deletion of CHIP in mice leads to the accumulation of non-aggregated, ubiquitin-negative, hyperphosphorylated tau species. CHIP-/- mice also have increased neuronal caspase-3 levels and activity, as well as caspase-cleaved tau immunoreactivity. Overexpression of mutant (P301L) human tau in CHIP-/- mice is insufficient to promote either argyrophilic or "pre-tangle" structures, despite marked phospho-tau accumulation throughout the brain. These observations are supported in post-developmental studies using RNA interference for CHIP (chn-1) in Caenorhabditis elegans and cell culture systems. Our results demonstrate that CHIP is a primary component in the ubiquitin-dependent degradation of tau. We also show that hyperphosphorylation and caspase-3 cleavage of tau both occur before aggregate formation. Based on these findings, we propose that polyubiquitination of tau by CHIP may facilitate the formation of insoluble filamentous tau lesions.

    Funded by: NIA NIH HHS: P01-AG17216; NINDS NIH HHS: P50-NS40256

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2006;26;26;6985-96

  • Truncated tau from sporadic Alzheimer's disease suffices to drive neurofibrillary degeneration in vivo.

    Zilka N, Filipcik P, Koson P, Fialova L, Skrabana R, Zilkova M, Rolkova G, Kontsekova E and Novak M

    Axon Neuroscience GmbH, Rennweg 95b, 1030 Vienna, Austria.

    Truncated tau protein is the characteristic feature of human sporadic Alzheimer's disease. We have identified truncated tau proteins conformationally different from normal healthy tau. Subpopulations of these structurally different tau species promoted abnormal microtubule assembly in vitro suggesting toxic gain of function. To validate pathological activity in vivo we expressed active form of human truncated tau protein as transgene, in the rat brain. Its neuronal expression led to the development of the neurofibrillary degeneration of Alzheimer's type. Furthermore, biochemical analysis of neurofibrillary changes revealed that massive sarcosyl insoluble tau complexes consisted of human Alzheimer's tau and endogenous rat tau in ratio 1:1 including characteristic Alzheimer's disease (AD)-specific proteins (A68). This work represents first insight into the possible causative role of truncated tau in AD neurofibrillary degeneration in vivo.

    FEBS letters 2006;580;15;3582-8

  • Polymerization of hyperphosphorylated tau into filaments eliminates its inhibitory activity.

    Alonso Adel C, Li B, Grundke-Iqbal I and Iqbal K

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314-6399, USA.

    Accumulation of abnormally hyperphosphorylated tau (P-tau) in the form of tangles of paired helical filaments and/or straight filaments is one of the hallmarks of Alzheimer's disease (AD) and other tauopathies. P-tau is also found unpolymerized in AD. Although the cognitive decline is known to correlate with the degree of neurofibrillary pathology, whether the formation of filaments or the preceding abnormal hyperphosphorylation of tau is the inhibitory entity that leads to neurodegeneration has been elusive. We have previously shown that cytosolic abnormally hyperphosphorylated tau in AD brain (AD P-tau) sequesters normal tau (N-tau), microtubule-associated protein (MAP) 1, and MAP2, which results in the inhibition of microtubule assembly and disruption of microtubules. Here, we show that polymerization of AD P-tau into filaments inhibits its ability to bind N-tau and as well as the ability to inhibit the assembly of tubulin into microtubules in vitro and in the regenerating microtubule system from cultured cells. Like AD P-tau, the in vitro abnormally hyperphosphorylated recombinant brain N-tau binds N-tau and loses this binding activity on polymerization into filaments. Dissociation of the hyperphosphorylated N-tau filaments by ultrasonication restores its ability to bind N-tau. These findings suggest that the nonfibrillized P-tau is most likely the responsible entity for the disruption of microtubules in neurons in AD. The efforts in finding a therapeutic intervention for tau-induced neurodegeneration need to be directed either to prevent the abnormal hyperphosphorylation of this protein or to neutralize its binding to normal MAPs, rather than to prevent its aggregation into filaments.

    Funded by: NIA NIH HHS: AG19158, R01 AG019158; NINDS NIH HHS: NS/NS31862

    Proceedings of the National Academy of Sciences of the United States of America 2006;103;23;8864-9

  • Tau aggregation and progressive neuronal degeneration in the absence of changes in spine density and morphology after targeted expression of Alzheimer's disease-relevant tau constructs in organotypic hippocampal slices.

    Shahani N, Subramaniam S, Wolf T, Tackenberg C and Brandt R

    Department of Neurobiology, University of Osnabrück, 49076 Osnabrück, Germany. neelam.shahani@biologie.uni-osnabrueck.de

    Alzheimer's disease (AD) is characterized by progressive loss of neurons in selected brain regions, extracellular accumulations of amyloid beta, and intracellular fibrils containing hyperphosphorylated tau. Tau mutations in familial tauopathies confirmed a central role of tau pathology; however, the role of tau alteration and the sequence of tau-dependent neurodegeneration in AD remain elusive. Using Sindbis virus-mediated expression of AD-relevant tau constructs in hippocampal slices, we show that disease-like tau modifications affect tau phosphorylation at selected sites, induce Alz50/MC1-reactive pathological tau conformation, cause accumulation of insoluble tau, and induce region-specific neurodegeneration. Live imaging demonstrates that tau-dependent degeneration is associated with the development of a "ballooned" phenotype, a distinct feature of cell death. Spine density and morphology is not altered as judged from algorithm-based evaluation of dendritic spines, suggesting that synaptic integrity is remarkably stable against tau-dependent degeneration. The data provide evidence that tau-induced cell death involves apoptotic as well as nonapoptotic mechanisms. Furthermore, they demonstrate that targeted expression of tau in hippocampal slices provides a novel model to analyze tau modification and spatiotemporal dynamics of tau-dependent neurodegeneration in an authentic CNS environment.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2006;26;22;6103-14

  • Hyperphosphorylation of tau induces local polyproline II helix.

    Bielska AA and Zondlo NJ

    Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.

    Alzheimer's disease is characterized by two protein precipitates, extracellular amyloid plaques and intracellular neurofibrillary tangles (NFTs). The primary constituent of NFTs is a hyperphosphorylated form of the microtubule-binding protein tau. Hyperphosphorylation of tau on over 30 residues, primarily within proline-rich sequences, is associated with conformational changes whose nature is poorly defined. Peptides derived from the proline-rich region of tau (residues 174-242) were synthesized, and the conformations were analyzed for the nonphosphorylated and phosphorylated peptides. CD and NMR data indicate that phosphorylation of serine and threonine residues in proline-rich sequences induces a conformational change to a type II polyproline helix. The largest phosphorylation-dependent conformational changes observed by CD were for tau peptides incorporating residues 174-183 or residues 229-238. Phosphoserine and phosphothreonine residues exhibited ordered values of (3)J(alphaN) (3.1-6.2 Hz; mean = 4.7 Hz) compared to nonphosphorylated serine and threonine. Phosphorylation of a tau peptide consisting of tau residues 196-209 resulted in the disruption of a nascent alpha-helix. These results suggest that global reorganization of tau may occur upon hyperphosphorylation of proline-rich sequences in tau.

    Biochemistry 2006;45;17;5527-37

  • The H2 MAPT haplotype is associated with familial frontotemporal dementia.

    Ghidoni R, Signorini S, Barbiero L, Sina E, Cominelli P, Villa A, Benussi L and Binetti G

    NeuroBioGen Lab-Memory Clinic, IRCCS Centro San Giovanni di Dio-Fatebenefratelli, via Pilastroni 4, 25125 Brescia, Italy.

    There is now considerable evidence that the gene encoding for tau protein (MAPT) is implicated in frontotemporal dementia (FTD). The role of MAPT haplotypes in neurodegenerative diseases has been suggested, but their contribution in familial dementia has not been extensively investigated. Here, we investigated (1) the association between the MAPT haplotypes and sporadic (sFTD) or familial FTD (FFTD) (controls n = 99, sFTD n = 53, FFTD n = 50), (2) the interactive effect between MAPT haplotypes and APOE gene. We found an overrepresentation of H2 haplotype (OR = 1.83, P = 0.029) and of H2H2 genotype in FFTD patients (OR = 6.09, P = 0.007). This association was even stronger in APOE e4 negatives FFTD (H2: OR = 2.9, P = 0.001; H2H2: OR = 12.67, P = 0.001). Our results support idea that the MAPT H2 haplotype is a risk factor for FFTD. This locus could contain this or other inheritable genetic determinants contributing to increase risk of developing dementia.

    Neurobiology of disease 2006;22;2;357-62

  • A MAPT mutation in a regulatory element upstream of exon 10 causes frontotemporal dementia.

    Malkani R, D'Souza I, Gwinn-Hardy K, Schellenberg GD, Hardy J and Momeni P

    Laboratory of Neurogenetics, National Institute on Aging, Porter Neuroscience Building, 35, Convent Drive, Bethesda, MD 20892, USA.

    We report here the genetic analysis of a newly ascertained kindred in which frontotemporal dementia occurs in an apparent autosomal dominant fashion, and in which a novel MAPT gene mutation co-segregates with disease. Sequencing the MAPT gene in affected individuals revealed a change in intron 9. This finding supports earlier studies on the effect of a splice-accepting element in inclusion of exon 10 in the MAPT transcript. This mutation sheds light on a novel mechanism by which over-expression of 4-repeat tau leads to disease. Based on our current findings, we propose a novel mechanism by which intronic mutations can lead to frontotemporal dementia.

    Funded by: NIA NIH HHS: R01 AG1176

    Neurobiology of disease 2006;22;2;401-3

  • Characterization of tau pathologies in gray and white matter of Guam parkinsonism-dementia complex.

    Winton MJ, Joyce S, Zhukareva V, Practico D, Perl DP, Galasko D, Craig U, Trojanowski JQ and Lee VM

    The Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4283, USA.

    Guam parkinsonism-dementia complex (PDC) is a neurodegenerative tauopathy in ethnic Chamorro residents of the Mariana Islands that manifests clinically with parkinsonism as well as dementia and is characterized neuropathologically by prominent cortical neuron loss in association with extensive telencephalic neurofibrillary tau pathology. To further characterize cortical gray and white matter tau, alpha-synuclein and lipid peroxidation pathologies in Guam PDC, we examined the brains of 17 Chamorro PDC and control subjects using biochemical and immunohistological techniques. We observed insoluble tau pathology in both gray and white matter of PDC and Guam control cases, with frontal and temporal lobes being most severely affected. Using phosphorylation dependent anti-tau antibodies, abundant tau inclusions were detected by immunohistochemistry in both neuronal and glial cells of the neocortex, while less alpha-synuclein pathology was observed in more limited brain regions. Further, in sharp contrast to Alzheimer's disease (AD), levels of the lipid peroxidation product 8, 12-iso-iPF(2alpha)-VI isoprostane were not elevated in Guam PDC brains relative to controls. Thus, although the tau pathologies of Guam PDC share similarities with AD, the composite Guam PDC neuropathology profile of tau, alpha-synuclein and 8, 12-iso-iPF(2alpha)-VI isoprostane reported here more closely resembles that seen in other tauopathies including frontotemporal dementias (FTDs), which may imply that Guam PDC and FTD tauopathies share underlying mechanisms of neurodegeneration.

    Funded by: NIA NIH HHS: AG14382

    Acta neuropathologica 2006;111;5;401-12

  • Pseudophosphorylation of tau at serine 422 inhibits caspase cleavage: in vitro evidence and implications for tangle formation in vivo.

    Guillozet-Bongaarts AL, Cahill ME, Cryns VL, Reynolds MR, Berry RW and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. LGD450@northwestern.edu

    The tangles of Alzheimer's disease (AD) are comprised of the tau protein displaying numerous alterations, including phosphorylation at serine 422 (S422) and truncation at aspartic acid 421 (D421). Truncation at the latter site appears to result from activation of caspases, a class of proteases that cleave specifically at aspartic acid residues. It has been proposed that phosphorylation at or near caspase cleavage sites could regulate the ability of the protease to cleave at those sites. Here, we use tau pseudophosphorylated at S422 (S422E) to examine the effects of tau phosphorylation on its cleavage by caspase 3. We find that S422E tau is more resistant to proteolysis by caspase 3 than non-pseudophosphorylated tau. Additionally, we use antibodies directed against the phosphorylation site and against the truncation epitope to assess the presence of these epitopes in neurofibrillary tangles in the aged human brain. We show that phosphorylation precedes truncation during tangle maturation. Moreover, the distribution of the two epitopes suggests that a significant length of time (perhaps as much as two decades) elapses between S422 phosphorylation and cleavage at D421. We further conclude that tau phosphorylation at S422 may be a protective mechanism that inhibits cleavage in vivo.

    Funded by: NIA NIH HHS: AG000257, AG020506, AG021661, AG09466, P30 AG13854

    Journal of neurochemistry 2006;97;4;1005-14

  • Region-specific dissociation of neuronal loss and neurofibrillary pathology in a mouse model of tauopathy.

    Spires TL, Orne JD, SantaCruz K, Pitstick R, Carlson GA, Ashe KH and Hyman BT

    Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Charlestown 02129, USA. tspires@partners.org

    Neurofibrillary tangles form in a specific spatial and temporal pattern in Alzheimer's disease. Although tangle formation correlates with dementia and neuronal loss, it remains unknown whether neurofibrillary pathology causes cell death. Recently, a mouse model of tauopathy was developed that reversibly expresses human tau with the dementia-associated P301L mutation. This model (rTg4510) exhibits progressive behavioral deficits that are ameliorated with transgene suppression. Using quantitative analysis of PHF1 immunostaining and neuronal counts, we estimated neuron number and accumulation of neurofibrillary pathology in five brain regions. Accumulation of PHF1-positive tau in neurons appeared between 2.5 and 7 months of age in a region-specific manner and increased with age. Neuron loss was dramatic and region-specific in these mice, reaching over 80% loss in hippocampal area CA1 and dentate gyrus by 8.5 months. We observed regional dissociation of neuronal loss and accumulation of neurofibrillary pathology, because there was loss of neurons before neurofibrillary lesions appeared in the dentate gyrus and, conversely, neurofibrillary pathology appeared without major cell loss in the striatum. Finally, suppressing the transgene prevented further neuronal loss without removing or preventing additional accumulation of neurofibrillary pathology. Together, these results imply that neurofibrillary tangles do not necessarily lead to neuronal death.

    Funded by: NIA NIH HHS: AG00277, AG08487, AG26249, P50 AG005134, R01 AG008487, R01 AG026249, T32 AG000277

    The American journal of pathology 2006;168;5;1598-607

  • Alzheimer disease-specific conformation of hyperphosphorylated paired helical filament-Tau is polyubiquitinated through Lys-48, Lys-11, and Lys-6 ubiquitin conjugation.

    Cripps D, Thomas SN, Jeng Y, Yang F, Davies P and Yang AJ

    Department of Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90089, USA.

    One of the key pathological hallmarks of Alzheimer disease (AD) is the accumulation of paired helical filaments (PHFs) of hyperphosphorylated microtubule-associated protein Tau. Tandem mass spectrometry was employed to examine PHF-Tau post-translational modifications, in particular protein phosphorylation and ubiquitination, to shed light on their role in the early stages of Alzheimer disease. PHF-Tau from Alzheimer disease brain was affinity-purified by MC1 monoclonal antibody to isolate a soluble fraction of PHF-Tau in a conformation unique to human AD brain. A large number of phosphorylation sites were identified by employing a data-dependent neutral loss algorithm to trigger MS3 scans of phosphopeptides. It was found that soluble PHF-Tau is ubiquitinated at its microtubule-binding domain at residues Lys-254, Lys-311, and Lys-353, suggesting that ubiquitination of PHF-Tau may be an earlier pathological event than previously thought and that ubiquitination could play a regulatory role in modulating the integrity of microtubules during the course of AD. Tandem mass spectrometry data for ubiquitin itself indicate that PHF-Tau is modified by three polyubiquitin linkages, at Lys-6, Lys-11, and Lys-48. Relative quantitative analysis indicates that Lys-48-linked polyubiquitination is the primary form of polyubiquitination with a minor portion of ubiquitin linked at Lys-6 and Lys-11. Because modification by Lys-48-linked polyubiquitin chains is known to serve as the essential means of targeting proteins for degradation by the ubiquitin-proteasome system, and it has been reported that modification at Lys-6 inhibits ubiquitin-dependent protein degradation, a failure of the ubiquitin-proteasome system could play a role in initiating the formation of degradation-resistant PHF tangles.

    Funded by: NIA NIH HHS: AG25323, R01 AG025323; NIMH NIH HHS: MH59786, R01 MH038623, R01 MH059786, T32 MH020069; PHS HHS: 38623

    The Journal of biological chemistry 2006;281;16;10825-38

  • Small ubiquitin-like modifier (SUMO) modification of natively unfolded proteins tau and alpha-synuclein.

    Dorval V and Fraser PE

    Department of Medical Biophysics and Centre for Research in Neurodegenerative Diseases, University of Toronto, 6 Queen's Park Crescent West, Toronto, Ontario M5S 3H2, Canada.

    Sumoylation is an important post-translational modification that provides a rapid and reversible means for controlling the activity, subcellular localization, and stability of target proteins. We have examined the covalent attachment of the small ubiquitin-like modifier (SUMO) proteins to tau and alpha-synuclein, two natively unfolded proteins that define several neurodegenerative diseases. Both brain proteins were preferentially modified by SUMO1, as compared with SUMO2 or SUMO3. Tau contains two SUMO consensus sequences, and mutational analyses identified Lys(340) as the major sumoylation site. Although both tau and alpha-synuclein are targets for proteasomal degradation, only tau sumoylation was affected by inhibitors of the proteasome pathway. Tau is a microtubule-associated protein, whose ability to bind and stabilize microtubules is negatively regulated by phosphorylation. Treatment with the phosphatase inhibitor, okadaic acid, or the microtubule depolymerizing drug, colchicine, up-regulated tau sumoylation. This suggests that SUMO modification may preferentially target a free soluble pool of the substrate. These findings revealed a new, possibly regulatory, modification of tau and alpha-synuclein that may also have implications for their pathogenic roles in neurodegenerative diseases.

    The Journal of biological chemistry 2006;281;15;9919-24

  • Peroxynitrite-mediated tau modifications stabilize preformed filaments and destabilize microtubules through distinct mechanisms.

    Reynolds MR, Lukas TJ, Berry RW and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. m-reynolds@md.northwestern.edu

    Alzheimer's disease (AD) is a progressive amnestic dementia typified by abnormal modifications of the microtubule (MT)-associated tau protein that promote its pathological self-assembly and displacement from the MT lattice. Previously, we showed that peroxynitrite (ONOO-) induces the oxidative 3,3'-dityrosine (3,3'-DT) cross-linking and site-selective nitration of tau monomers [Reynolds et al. (2005) Biochemistry 44, 1690-1700]. In the present study, we examined the effects of ONOO(-)-mediated modifications on two key elements of tau pathobiology: (1) the stability of preformed tau filaments and (2) the ability of monomeric tau to promote tubulin assembly. Here, we report that treatment of synthetic tau filaments with ONOO- generates heat-stable, SDS-insoluble aggregates with a significantly reduced mobility by SDS-PAGE compared to that of nontreated filaments. Ultrastructurally, these aggregates appear to be cross-linked via interfilament bridges. Using LC-MS/MS and HPLC with fluorescent detection, we demonstrate that covalent 3,3'-DT linkages are present within these higher-order aggregates. Similar to monomeric tau, filamentous tau exhibits a hierarchical pattern of nitration following ONOO- treatment with site selectivity toward the amino-terminal residues Tyr18 and Tyr29. Further, select nitration of residues Tyr18, Tyr29, Tyr197, and Tyr394, events known to stabilize the pathological Alz-50 conformation [Reynolds et al. (2005) Biochemistry 44, 13997-14009], inhibits the ability of monomeric tau to promote tubulin assembly. This effect is specific for the 3-NT modification, as mutant tau proteins pseudophosphorylated at each Tyr residue are fully competent to stabilize MTs. Collectively, our results suggest that ONOO(-)-mediated modifications stabilize tau filaments via 3,3'-DT bonding and destabilize MTs by site-selective nitration of tau monomers. Moreover, assumption of the Alz-50 conformation may be the mechanism through which tau nitration modulates MT stability.

    Funded by: NIA NIH HHS: AG 14453, AG 21184; NINDS NIH HHS: F30 NS051043

    Biochemistry 2006;45;13;4314-26

  • Brain-specific change in alternative splicing of Tau exon 6 in myotonic dystrophy type 1.

    Leroy O, Wang J, Maurage CA, Parent M, Cooper T, Buée L, Sergeant N, Andreadis A and Caillet-Boudin ML

    INSERM U422, Pl. de Verdun. 59045 Lille Cedex- France.

    Alternative splicing is altered in myotonic dystrophy of type 1 (DM1), a syndrome caused by an increase of CTG triplet repeats in the 3' untranslated region of the myotonic dystrophy protein kinase gene. Previously, we reported the preferential skipping of Tau exon 2 in DM1 brains. In this study, we analyze the alternative splicing of Tau exon 6 which can be inserted in three different forms (c, p and d) depending on the 3' splice site used. In fact, inclusion of exon 6c decreases in DM1 brains compared to control brains whereas inclusion of 6d increases. Alteration of exon 6 splicing was not observed in DM1 muscle although this exon was inserted in RNAs from normal muscle and DM1 splicing alterations were first described in this organ. In contrast, alteration of exon 2 of Tau mRNA was observed in both muscle and brain. However, co-transfections of a minigene containing exon 6 with CELF or MBNL1 cDNAs, two splicing factor families suspected to be involved in DM1, showed that they influence exon 6 splicing. Altogether, these results show the importance of determining all the exons and organs targeted by mis-splicing to determine the dysregulation mechanisms of mis-splicing in DM1.

    Funded by: NIAMS NIH HHS: R01 AR45653; NICHD NIH HHS: P01 HD05515

    Biochimica et biophysica acta 2006;1762;4;460-7

  • c-jun N-terminal kinase hyperphosphorylates R406W tau at the PHF-1 site during mitosis.

    Tatebayashi Y, Planel E, Chui DH, Sato S, Miyasaka T, Sahara N, Murayama M, Kikuchi N, Yoshioka K, Rivka R and Takashima A

    Laboratory for Alzheimer's Disease, Brain Science Institute, The Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.

    Tauopathies such as Alzheimer disease (AD) probably involve a type of phosphorylation imbalance causing the accumulation of abnormally hyperphosphorylated tau in neurons and/or glias. Investigation of R406W tau mutation may provide insight into such abnormal tau hyperphosphorylation, since this mutation causes AD-like dementia and tauopathy in humans and because it has the unique ability to reduce tau phosphorylation in vitro and in cultured cells. Here we show that R406W mutation primarily disrupts tau phosphorylation at Ser404, a priming phosphorylation site of glycogen synthase kinase-3beta (GSK-3beta), thereby reducing subsequent GSK-3beta-mediated phosphorylation at the PHF-1 site (mostly Ser396). In contrast, c-jun N-terminal kinase (JNK) as activated in the mitotic phase directly hyperphosphorylates R406W tau at the PHF-1 site. This was confirmed by PHF-1 hyperphosphorylation of R406W tau in mitotic cells, its association with cytoplasmic JNK activation, and its inhibition by a JNK inhibitor, SP600125. These data unveil the unknown mechanisms of physiological tau phosphorylation at the PHF-1 site and suggest that cytoplasmic JNK activation may play an important role in the abnormal tau hyperphosphorylation associated with R406W tau mutation and in AD.

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2006;20;6;762-4

  • Copper binding properties of a tau peptide associated with Alzheimer's disease studied by CD, NMR, and MALDI-TOF MS.

    Ma Q, Li Y, Du J, Liu H, Kanazawa K, Nemoto T, Nakanishi H and Zhao Y

    Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, PR China.

    We have previously reported the copper binding properties of R3 peptide (residues 318-335: VTSKCGSLGNIHHKPGGG, according to the longest tau protein) derived from the third repeat microtubule-binding domain of water-soluble tau protein. In this work, we have investigated copper binding properties of R2 peptide (residues 287-304: VQSKCGSKDNIKHVPGGG) derived from the second repeat region of tau protein. Similar to R3 peptide, R2 peptide also plays an important role in the formation of neurofibrillary tangles (NFTs) which is one of the two main biological characteristics of Alzheimer's disease (AD). Based on the copper binding properties of R2 peptide, the possible influences of the binding on the formation of NFTs were investigated. Results from circular dichroism (CD) spectra, nuclear magnetic resonance (NMR) spectroscopy, and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) suggest that the binding is pH-dependent and stoichiometry-determined. In addition, these results also reveal that R2 peptide adopts a monomeric alpha-helical structure in aqueous solutions at physiological pH after the addition of 1 mol equiv. of Cu2+. Since alpha-helix structure is responsible for the formation of paired helical filaments (PHFs) which aggregate into NFTs, it is hypothesized that Cu2+ induces R2 peptide to self-assemble into a PHFs-like structure. Hence, it is postulated that Cu2+ plays an important role in the aggregation of R2 peptide and tau protein and that copper binding to R2 peptide may be another possible involvement in AD.

    Peptides 2006;27;4;841-9

  • Flow cytometry-based method to analyze the change in Tau phosphorylation in a hGSK-3beta and hTau over-expressing EcR-293 cell line.

    Kurko D, Boros A, Dezso P, Urbányi Z, Sárvári M, Nagy J, Szombathelyi Z and Szendrei GI

    Pharmacological and Drug Safety Research, Gedeon Richter Ltd., Budapest, Hungary.

    Neurofibrillary tangles are composed of insoluble aggregates of microtubule-associated protein Tau. In the pathology of Alzheimer's disease (AD), accumulation of hyperphosphorylated Tau results in formation of paired helical filaments. One of the main candidate to hyperphosphorylate Tau in AD is glycogen synthase kinase 3beta (GSK-3beta). Here we introduce a non-neuronal cell line, stably co-expressing human Tau and GSK-3beta proteins, where the effect of potential kinase inhibitors on Tau phosphorylation can be monitored. The aim of our study was to establish a new flow-cytometry-based method to quantitatively analyze the changing of Tau phosphorylation, which is a suitable alternative to the well-accepted but non-quantitative Western blot technique. Our results demonstrate that the flow cytometry-based method is a convenient tool to analyze the effect of GSK-3beta inhibitors on Tau phosphorylation. This new approach provides appropriate throughput for screening purposes in preclinical research for characterization of GSK-3beta inhibitors, as potential drug candidate to cure Alzheimer's disease.

    Neurochemistry international 2006;48;5;374-82

  • HSP induction mediates selective clearance of tau phosphorylated at proline-directed Ser/Thr sites but not KXGS (MARK) sites.

    Dickey CA, Dunmore J, Lu B, Wang JW, Lee WC, Kamal A, Burrows F, Eckman C, Hutton M and Petrucelli L

    Mayo Clinic Jacksonville, College of Medicine, Jacksonville, Florida, USA.

    Neurofibrillary tangles (NFTs) are a characteristic neuropathological feature of Alzheimer's disease (AD), and molecular chaperones appear to be involved in the removal of disease-associated hyperphosphorylated tau, a primary component of NFTs. Here, novel HSP90 inhibitors were used to examine the impact of chaperone elevation on clearance of different tau species in transfected cells using a unique quantitative assay. The HSP90 inhibitors reduced levels of tau phosphorylated at proline-directed Ser/Thr sites (pS202/T205, pS396/S404) and conformationally altered (MC-1) tau species, an epitope that is immeasurable by standard Western blot techniques. The selective clearance of these phospho-tau species and MC-1 tau was mediated via the proteasome, while lysosomal-mediated tau degradation seems to lack specificity for certain tau species, suggesting a more general role in total tau removal. Interestingly, tau phosphorylated at S262/S356 within the tau microtubule binding domain was minimally affected by chaperone induction. Overall, our data show that chaperone induction results in the selective clearance of specific phospho-tau and conformationally altered tau species mediated by the proteasome; however, the apparent stability of pS262/S356 tau may also explain why MARK is able to regulate normal tau function yet still be linked to the initiation of pathogenic tau hyperphosphorylation in AD.

    Funded by: NIA NIH HHS: P01 AG17216

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2006;20;6;753-5

  • Acetylsalicylic acid decreases tau phosphorylation at serine 422.

    Tortosa E, Avila J and Pérez M

    Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.

    Tau protein pathology in Alzheimer's disease is characterized by the hyperphosphorylation of tau at some specific sites. One of these sites is serine 422 which modification has been correlated with a possible toxic effect of phosphotau in neural cells. In this work, we have found that in the presence of acetylsalicylic acid, at a concentration like that used for anti-inflammatory treatments, tau phosphorylation at serine 422 decreases.

    Neuroscience letters 2006;396;1;77-80

  • Cyclin-dependent protein kinase 5 primes microtubule-associated protein tau site-specifically for glycogen synthase kinase 3beta.

    Li T, Hawkes C, Qureshi HY, Kar S and Paudel HK

    Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.

    In the preceding paper, we showed that GSK3beta phosphorylates tau at S(202), T(231), S(396), and S(400) in vivo. Phosphorylation of S(202) occurs without priming. Phosphorylation of T(231), on the other hand, requires priming phosphorylation of S(235). Similarly, priming phosphorylation of S(404) is essential for the sequential phosphorylation of S(400) and S(396) by GSK3beta. The priming kinase that phosphorylates tau at S(235) and S(404) in the brain is not known. In this study, we find that in HEK-293 cells cotransfected with tau, GSK3beta, and Cdk5, Cdk5 phosphorylates tau at S(202), S(235), and S(404). S(235) phosphorylation enhances GSK3beta-catalyzed T(231) phosphorylation. Similarly, Cdk5 by phosphorylating S(404) stimulates phosphorylation of S(400) and S(396) by GSK3beta. These data indicate that Cdk5 primes tau for GSK3beta in intact cells. To evaluate if Cdk5 primes tau for GSK3beta in mammalian brain, we examined localizations of Cdk5, tau, and GSK3beta in rat brain. We also analyzed the interaction of Cdk5 with tau and GSK3beta in brain microtubules. We found that Cdk5, GSK3beta, and tau are virtually colocalized in rat brain cortex. When bovine brain microtubules are analyzed by FPLC gel filtration, Cdk5, GSK3beta, and tau coelute within an approximately 450 kDa complex. From the fractions containing the approximately 450 kDa complex, tau, Cdk5, and GSK3beta co-immunoprecipitate with each other. In HEK-293 cells transfected with tau, Cdk5, and GSK3beta in different combinations, tau binds to Cdk5 in a manner independent of GSK3beta and to GSK3beta in a manner independent of Cdk5. However, Cdk5 and GSK3beta bind to each other only in the presence of tau, suggesting that tau connects Cdk5 and GSK3beta. Our results suggest that in the brain, tau, Cdk5, and GSK3beta are components of an approximately 450 kDa complex. Within the complex, Cdk5 phosphorylates tau at S(235) and primes it for phosphorylation of T(231) by GSK3beta. Similarly, Cdk5 by phosphorylating tau at S(404) primes tau for a sequential phosphorylation of S(400) and S(396) by GSK3beta.

    Biochemistry 2006;45;10;3134-45

  • The CSF levels of total-tau and phosphotau in patients with relapsing-remitting multiple sclerosis.

    Bartosik-Psujek H and Stelmasiak Z

    Department of Neurology, Medical University of Lublin, Lublin, Poland. bartosikpsujek@op.pl

    Total-tau protein is considered the marker of axon damage whereas the abnormally phosphorylated tau forms are mainly associated with Alzheimer's disease. An increase in total-tau levels was observed in neurodegenerative diseases, including multiple sclerosis (MS). In order to find out whether the phosphorylated tau forms occur in MS patients and to evaluate their clinical significance, the levels of total-tau (t-tau) and tau phosphorylated at Thr 181 (p-tau) were determined in 60 MS patients (40 during relapse including 18 with the first relapse and 20 stable) and in 18 age-matched controls. The determinations were conducted in the cerebrospinal fluid (CSF) using the ELISA method. The levels of t-tau and p-tau were higher in MS patients than in controls; however, increased levels were not related to the clinical activity of the disease. In CSF of the patients with the first relapse the level of t-tau was significantly increased whilst the level of p-tau was not elevated.

    Journal of neural transmission (Vienna, Austria : 1996) 2006;113;3;339-45

  • Shift in the ratio of three-repeat tau and four-repeat tau mRNAs in individual cholinergic basal forebrain neurons in mild cognitive impairment and Alzheimer's disease.

    Ginsberg SD, Che S, Counts SE and Mufson EJ

    Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York 10962, USA. ginsberg@nki.rfmh.org

    Molecular mechanisms underlying tauopathy remain undetermined. In the current study, single cell gene expression profiling was coupled with custom-designed cDNA array analysis to evaluate tau expression and other cytoskeletal elements within individual neuronal populations in patients with no cognitive impairment (NCI), mild cognitive impairment (MCI), and Alzheimer's disease (AD). Results revealed a shift in the ratio of three-repeat tau (3Rtau) to four-repeat tau (4Rtau) mRNAs within individual human cholinergic basal forebrain (CBF) neurons within nucleus basalis (NB) and CA1 hippocampal neurons during the progression of AD, but not during normal aging. A shift in 3Rtau to 4Rtau may precipitate a cascade of events in the selective vulnerability of neurons, ultimately leading to frank neurofibrillary tangle (NFT) formation in tauopathies including AD.

    Funded by: NIA NIH HHS: AG10161, AG10688, AG14449, AG21661; NINDS NIH HHS: NS43939; PHS HHS: A6026032

    Journal of neurochemistry 2006;96;5;1401-8

  • Three-repeat Tau 69 is a major tau isoform in laser-microdissected Pick bodies.

    Ohkubo T, Sakasegawa Y, Toda H, Kishida H, Arima K, Yamada M, Takahashi H, Mizusawa H, Hachiya NS and Kaneko K

    Second Department of Physiology, Tokyo Medical University, Tokyo, Japan.

    By utilizing a novel combinatorial method of a Laser Microdissection System and Western blot analysis, we demonstrate that a distinct isoform of abnormally phosphorylated tau (69 kDa, Tau 69) predominantly aggregated in laser-microdissected Pick bodies (PBs) in sporadic Pick's disease. By contrast, tau migrated as two major bands of 60 and 64 kDa (Tau 60 and 64) in total brain homogenates as previously reported. Comparative immunohistochemical analysis with anti-4-repeat antibody revealed that a major component of the abnormally phosphorylated tau in these PBs was 3-repeat tau (3R-tau). Whether 29 amino acid repeat encoded by exons 2 and 3 in the Tau 69 might accelerate the formation of PBs remains to be further investigated. Such a combination of morphological and biochemical techniques significantly complements the existing histopathological methods.

    Amyloid : the international journal of experimental and clinical investigation : the official journal of the International Society of Amyloidosis 2006;13;1;1-5

  • Global hairpin folding of tau in solution.

    Jeganathan S, von Bergen M, Brutlach H, Steinhoff HJ and Mandelkow E

    Max Planck Unit for Structural Molecular Biology, Notkestrasse 85, D-22607 Hamburg, Germany.

    The microtubule-associated protein tau stabilizes microtubules in its physiological role, whereas it forms insoluble aggregates (paired helical filaments) in Alzheimer's disease. Soluble tau is considered a natively unfolded protein whose residual folding and intramolecular interactions are largely undetermined. In this study, we have applied fluorescence resonance energy transfer (FRET) and electron paramagnetic resonance (EPR) to examine the proximity and flexibility of tau domains and the global folding. FRET pairs spanning the tau molecule were created by inserting tryptophans (donor) and cysteines (labeled with IAEDANS as an acceptor) by site-directed mutagenesis. The observed FRET distances were significantly different from those expected for a random coil. Notably, the C-terminal end of tau folds over into the vicinity of the microtubule-binding repeat domain, the N-terminus remains outside the FRET distance of the repeat domain, yet both ends of the molecule approach one another. The interactions between the domains were obliterated by denaturation in GdnHCl. Paramagnetic spin-labels attached in various domains of tau were analyzed by EPR and exhibited a high mobility throughout. The data indicate that tau retains some global folding even in its "natively unfolded" state, combined with the high flexibility of the chain.

    Biochemistry 2006;45;7;2283-93

  • NMDA receptor mediates tau-induced neurotoxicity by calpain and ERK/MAPK activation.

    Amadoro G, Ciotti MT, Costanzi M, Cestari V, Calissano P and Canu N

    Dipartimento di Neuroscienze, Università di Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.

    The altered function and/or structure of tau protein is postulated to cause cell death in tauopathies and Alzheimer's disease. However, the mechanisms by which tau induces neuronal death remain unclear. Here we show that overexpression of human tau and of some of its N-terminal fragments in primary neuronal cultures leads to an N-methyl-D-aspartate receptor (NMDAR)-mediated and caspase-independent cell death. Death signaling likely originates from stimulation of extrasynaptic NR2B-subunit-containing NMDARs because it is accompanied by dephosphorylation of cAMP-response-element-binding protein (CREB) and it is inhibited by ifenprodil. Interestingly, activation of NMDAR leads to a crucial, sustained, and delayed phosphorylation of extracellular-regulated kinases 1 and 2, whose inhibition largely prevents tau-induced neuronal death. Moreover, NMDAR involvement causes the fatal activation of calpain, which, in turn, degrades tau protein into a 17-kDa peptide and possibly other highly toxic N-terminal peptides. Some of these peptides are hypothesized, on the basis of our in vitro experiments, to initiate a negative loop, ultimately leading to cell death. Thus, inhibition of calpain largely prevents tau degradation and cell death. Our findings unravel a cellular mechanism linking tau toxicity to NMDAR activation and might be relevant to Alzheimer's disease and tauopathies where NMDAR-mediated toxicity is postulated to play a pivotal role.

    Proceedings of the National Academy of Sciences of the United States of America 2006;103;8;2892-7

  • Abeta and tau form soluble complexes that may promote self aggregation of both into the insoluble forms observed in Alzheimer's disease.

    Guo JP, Arai T, Miklossy J and McGeer PL

    Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.

    To date, there is no reasonable explanation as to why plaques and tangles simultaneously accumulate in Alzheimer's disease (AD). We demonstrate here by Western blotting and ELISA that a stable complex can form between tau and amyloid-beta protein (Abeta). This complex enhances tau phosphorylation by GSK3beta, but the phosphorylation then promotes dissociation of the complex. We have localized the sites of this interaction by using peptide membrane arrays. Abeta binds to multiple tau peptides, especially those in exons 7 and 9. This binding is sharply reduced or abolished by phosphorylation of specific serine and threonine residues. Conversely, tau binds to multiple Abeta peptides in the mid to C-terminal regions of Abeta. This binding is also significantly decreased by GSK3beta phosphorylation of tau. We used surface plasmon resonance to determine the binding affinity of Abeta for tau and found it to be in the low nanomolar range and almost 1,000-fold higher than tau for itself. In soluble extracts from AD and control brain tissue, we detected Abeta bound to tau in ELISAs. We also found by double immunostaining of AD brain tissue that phosphorylated tau and Abeta form separate insoluble complexes within the same neurons and their processes. We hypothesize that in AD, an initial step in the pathogenesis may be the intracellular binding of soluble Abeta to soluble nonphosphorylated tau, thus promoting tau phosphorylation and Abeta nucleation. Blocking the sites where Abeta initially binds to tau might arrest the simultaneous formation of plaques and tangles in AD.

    Proceedings of the National Academy of Sciences of the United States of America 2006;103;6;1953-8

  • The alternative splicing of tau exon 10 and its regulatory proteins CLK2 and TRA2-BETA1 changes in sporadic Alzheimer's disease.

    Glatz DC, Rujescu D, Tang Y, Berendt FJ, Hartmann AM, Faltraco F, Rosenberg C, Hulette C, Jellinger K, Hampel H, Riederer P, Möller HJ, Andreadis A, Henkel K and Stamm S

    Molecular and Clinical Neurobiology, Department of Psychiatry Ludwig-Maximilians-University, Munich, Germany.

    Pathological inclusions containing fibrillar aggregates of hyperphosphorylated tau protein are a characteristic feature in tauopathies, which include Alzheimer's disease (AD). Tau is a microtubule-associated protein whose transcript undergoes alternative splicing in the brain. Exon 10 encodes one of four microtubule-binding repeats. Exon 10 inclusion gives rise to tau protein isoforms containing four microtubule-binding repeats (4R) whereas exclusion leads to isoforms containing only three repeats (3R). The ratio between 3R and 4R isoforms is tightly controlled via alternative splicing in the human adult nervous system and distortion of this balance results in neurodegeneration. Previous studies showed that several splicing regulators, among them hTRA2-beta1 and CLK2, regulate exon 10 alternative splicing. Like most splicing factors, htra2-beta and clk2 pre-mRNAs are regulated by alternative splicing. Here, we investigated whether human postmortem brain tissue of AD patients reveal differences in alternative splicing patterns of the tau, htra2-beta, presenilin 2 and clk2 genes when compared with age-matched controls. We found that the splicing patterns of all four genes are altered in affected brain areas of sporadic AD patients. In these affected areas, the amount of mRNAs of tau isoforms including exon 10, the htra2-beta1 isoform and an inactive form of clk2 are significantly increased. These findings suggest that a misregulation of alternative splicing seems to contribute to sporadic AD.

    Journal of neurochemistry 2006;96;3;635-44

  • Beta-protein/A4 deposits are not associated with hyperphosphorylated tau in somatostatin neurons in the hypothalamus of Alzheimer's disease patients.

    van de Nes JA, Konermann S, Nafe R and Swaab DF

    Institute of Neuropathology, University Hospital Essen, 45122, Essen, Germany. johannes.van.de.nes@uni-essen.de

    With respect to the pathogenesis of Alzheimer's disease (AD), it has been hypothesized that amorphous plaques containing beta-protein/A4 (Abeta) would locally induce cytoskeletal changes, and that neurons affected by neurofibrillary tangles (NFTs) lose their neuropeptide concentration and eventually die. To test this presumed cascade of events, the hypothalami of 14 non-demented subjects (Braak 0-III) and 28 AD patients (Braak IV-VI) aged 40-98 years were selected. The subject of our study was the nucleus tuberalis lateralis (NTL), which harbors a subpopulation of somatostatinergic neurons with extensive intrinsic interconnectivity. We used Gallyas silver staining, Congo staining, single- and double-staining with monoclonal antibody AT8 and polyclonal antibody anti-Abeta, and double-immunolabeling with AT8 and anti-somatostatin(1-12) with the following results: (1) Significant amounts of silver-staining NFTs were present in only three AD patients. (2) High densities of AT8-stained cytoskeletal changes were mainly found in aged, demented patients. (3) In contrast, large amounts of Abeta deposits were mainly observed in young and middle-aged (40-59 years) AD patients, and were very low or absent mainly in the older non-demented subjects and in AD patients. (4) Reduced anti-somatostatin staining was observed in the NTL of most AD patients, but anti-somatostatin/AT8 double-stained neurons were found virtually exclusively in aged AD patients. Thus, the occurrence of Abeta deposits and hyperphosphorylated tau formation in somatostatin cells are basically independent events, while decreased somatostatin staining only partly goes together with cytoskeletal changes in somatostatin cells in the NTL of AD patients. These observations cannot be explained by the amyloid cascade hypothesis.

    Acta neuropathologica 2006;111;2;126-38

  • Identification of VCP/p97, carboxyl terminus of Hsp70-interacting protein (CHIP), and amphiphysin II interaction partners using membrane-based human proteome arrays.

    Grelle G, Kostka S, Otto A, Kersten B, Genser KF, Müller EC, Wälter S, Böddrich A, Stelzl U, Hänig C, Volkmer-Engert R, Landgraf C, Alberti S, Höhfeld J, Strödicke M and Wanker EE

    Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, D-13125 Berlin-Buch, Germany.

    Proteins mediate their biological function through interactions with other proteins. Therefore, the systematic identification and characterization of protein-protein interactions have become a powerful proteomic strategy to understand protein function and comprehensive cellular regulatory networks. For the screening of valosin-containing protein, carboxyl terminus of Hsp70-interacting protein (CHIP), and amphiphysin II interaction partners, we utilized a membrane-based array technology that allows the identification of human protein-protein interactions with crude bacterial cell extracts. Many novel interaction pairs such as valosin-containing protein/autocrine motility factor receptor, CHIP/caytaxin, or amphiphysin II/DLP4 were identified and subsequently confirmed by pull-down, two-hybrid and co-immunoprecipitation experiments. In addition, assays were performed to validate the interactions functionally. CHIP e.g. was found to efficiently polyubiquitinate caytaxin in vitro, suggesting that it might influence caytaxin degradation in vivo. Using peptide arrays, we also identified the binding motifs in the proteins DLP4, XRCC4, and fructose-1,6-bisphosphatase, which are crucial for the association with the Src homology 3 domain of amphiphysin II. Together these studies indicate that our human proteome array technology permits the identification of protein-protein interactions that are functionally involved in neurodegenerative disease processes, the degradation of protein substrates, and the transport of membrane vesicles.

    Molecular & cellular proteomics : MCP 2006;5;2;234-44

  • Inducible expression of Tau repeat domain in cell models of tauopathy: aggregation is toxic to cells but can be reversed by inhibitor drugs.

    Khlistunova I, Biernat J, Wang Y, Pickhardt M, von Bergen M, Gazova Z, Mandelkow E and Mandelkow EM

    Max-Planck-Unit for Structural Molecular Biology, DESY, Hamburg, Germany.

    We generated several cell models of tauopathy in order to study the mechanisms of neurodegeneration in diseases involving abnormal changes of tau protein. N2a neuroblastoma cell lines were created that inducibly express different variants of the repeat domain of tau (tau(RD)) when exposed to doxycycline (Tet-On system). The following three constructs were chosen: (i) the repeat domain of tau that coincides with the core of Alzheimer paired helical filaments; (ii) the repeat domain with the deletion mutation DeltaK280 known from frontotemporal dementia and highly prone to spontaneous aggregation; and (iii) the repeat domain with DeltaK280 and two proline point mutations that inhibit aggregation. The comparison of wild-type, pro-aggregation, and anti-aggregation mutants shows the following. (a) Aggregation of tau(RD) is toxic to cells. (b) The degree of aggregation and toxicity depends on the propensity for beta-structure. (c) Soluble mutants of tau(RD) that cannot aggregate are not toxic. (d) Aggregation is preceded by fragmentation. (e) Fragmentation of tau(RD) in cells is initially due to a thrombin-like protease activity. (f) Phosphorylation of tau(RD) (at KXGS motifs) precedes aggregation but is not correlated with the degree of aggregation. (g) Aggregates of tau(RD) disappear when the expression is silenced, showing that aggregation is reversible. (h) Aggregation can be prevented by drugs and even pre-formed aggregates can be dissolved again by drugs. Thus, the cell models open up new insights into the relationship between the structure, expression, phosphorylation, aggregation, and toxicity of tau(RD) that can be used to test current hypotheses on tauopathy and to develop drugs that prevent the aggregation and degeneration of cells.

    The Journal of biological chemistry 2006;281;2;1205-14

  • P70 S6 kinase mediates tau phosphorylation and synthesis.

    Pei JJ, An WL, Zhou XW, Nishimura T, Norberg J, Benedikz E, Götz J and Winblad B

    Department of Neurotec, Division of Experimental Geriatrics, Karolinska Institutet, KFC Novum, Plan 4, SE-141 86, Huddinge, Sweden. Jin-Jing.Pei@neurotec.ki.se

    Currently, we found that the 70-kDa p70 S6 kinase (p70S6K) directly phosphorylates tau at S262, S214, and T212 sites in vitro. By immunoprecipitation, p-p70S6K (T421/S424) showed a close association with p-tau (S262 and S396/404). Zinc-induced p70S6K activation could only upregulate translation of total S6 and tau but not global proteins in SH-SY5Y cells. The requirement of p70S6K activation was confirmed in the SH-SY5Y cells that overexpress wild-type htau40. Level of p-p70S6K (T421/S424) was only significantly correlated with p-tau at S262, S214, and T212, but not T212/S214, in Alzheimer's disease (AD) brains. These suggested that p70S6K might contribute to tau related pathologies in AD brains.

    FEBS letters 2006;580;1;107-14

  • A 17q21.31 microdeletion encompassing the MAPT gene in a mentally impaired patient.

    Varela MC, Krepischi-Santos AC, Paz JA, Knijnenburg J, Szuhai K, Rosenberg C and Koiffmann CP

    Human Genome Study Center, University of São Paulo, São Paulo, Brazil.

    About 15% of patients with a clinical phenotype of Angelman syndrome (AS) have an unknown etiology. We report a patient with features reminiscent of AS, including a pattern of characteristic facial anomalies as well as speech impairment, developmental delay and frequent laughter. In addition, the patient had features not commonly associated with AS such as heart malformations and scoliosis. She was negative in SNURF-SNRPN exon 1 methylation studies and the G-banded karyotype was normal. Array-based comparative genomic hybridization disclosed a deletion of maximally 1 Mb at 17q21.31. The deleted region contains the MAPT gene, implicated in late onset neurodegenerative disorders, and the STH and NP_056258.1 genes. Another gene, such as CRHR1, might also be included based on maximum possible size of the deletion. We suggest that microdeletions within the 17q21.31 segment should be considered as a possible cause of phenotypes resembling AS, particularly when easily controlled seizures and/or cardiac abnormalities are also present.

    Cytogenetic and genome research 2006;114;1;89-92

  • Analysis of IFT74 as a candidate gene for chromosome 9p-linked ALS-FTD.

    Momeni P, Schymick J, Jain S, Cookson MR, Cairns NJ, Greggio E, Greenway MJ, Berger S, Pickering-Brown S, Chiò A, Fung HC, Holtzman DM, Huey ED, Wassermann EM, Adamson J, Hutton ML, Rogaeva E, St George-Hyslop P, Rothstein JD, Hardiman O, Grafman J, Singleton A, Hardy J and Traynor BJ

    Laboratory of Neurogenetics, National Institute of Aging, NIH, Bethesda, MD, USA. momeni@mail.nih.gov <momeni@mail.nih.gov&gt;

    Background: A new locus for amyotrophic lateral sclerosis--frontotemporal dementia (ALS-FTD) has recently been ascribed to chromosome 9p.

    Methods: We identified chromosome 9p segregating haplotypes within two families with ALS-FTD (F476 and F2) and undertook mutational screening of candidate genes within this locus.

    Results: Candidate gene sequencing at this locus revealed the presence of a disease segregating stop mutation (Q342X) in the intraflagellar transport 74 (IFT74) gene in family 476 (F476), but no mutation was detected within IFT74 in family 2 (F2). While neither family was sufficiently informative to definitively implicate or exclude IFT74 mutations as a cause of chromosome 9-linked ALS-FTD, the nature of the mutation observed within F476 (predicted to truncate the protein by 258 amino acids) led us to sequence the open reading frame of this gene in a large number of ALS and FTD cases (n = 420). An additional sequence variant (G58D) was found in a case of sporadic semantic dementia. I55L sequence variants were found in three other unrelated affected individuals, but this was also found in a single individual among 800 Human Diversity Gene Panel samples.

    Conclusion: Confirmation of the pathogenicity of IFT74 sequence variants will require screening of other chromosome 9p-linked families.

    Funded by: NIA NIH HHS: P50 AG05681, P50 AG08702

    BMC neurology 2006;6;44

  • Association of tau haplotype-tagging polymorphisms with Parkinson's disease in diverse ethnic Parkinson's disease cohorts.

    Fung HC, Xiromerisiou G, Gibbs JR, Wu YR, Eerola J, Gourbali V, Hellström O, Chen CM, Duckworth J, Papadimitriou A, Tienari PJ, Hadjigeorgiou GM, Hardy J and Singleton AB

    Molecular Genetics Unit, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.

    Background: The overlap in the clinical and pathological features of tauopathies and synucleinopathies raises the possibility that the tau protein may be important in Parkinson's disease (PD) pathogenesis. Several MAPT polymorphisms that define the tau H1 haplotype have been investigated for an association with PD with conflicting results; however, two meta-analyses support an association between haplotype H1 and PD.

    Methods: In this study, we recruited 508 patients and 611 healthy controls from Greek, Finnish and Taiwanese populations. We examined the possible genetic role of variation within MAPT in PD using haplotype-tagging single polymorphisms (SNPs) in these ethnically different PD populations.

    Results: We identified a moderate association at SNP rs3785883 in the Greek cohort for both allele and genotype frequency (p = 0.01, p = 0.05, respectively) as well as for SNP rs7521 (genotype p = 0.02) and rs242557 (p = 0.01 genotypic, p = 0.04 allelic) in the Finnish population. There were no significant differences in genotype or allele distribution between cases and controls in the Taiwanese cohort.

    Conclusion: We failed to demonstrate a consistent association between the MAPT H1 haplotype (delineated by intron 9 ins/del) and PD in three ethnically diverse populations. However, the data presented here suggest that subhaplotypes of haplotype H1 may confer susceptibility to PD, and that either allelic heterogeneity or different haplotype composition explain the divergent haplotype results.

    Funded by: Medical Research Council: G0701075

    Neuro-degenerative diseases 2006;3;6;327-33

  • Effect of acetylcholine on tau phosphorylation in human neuroblastoma cells.

    Rubio A, Avila J and Pérez M

    Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma de Madrid, 28048 Madrid, Spain.

    Alzheimer's disease (AD) is a senile dementia characterized by a progressive loss of memory, together with cognitive and behavioral impairments. In the past it was indicated that the disease was associated with a loss of acetylcholine (ACh) in the cerebral cortex (Bowen et al., 1976; Davies and Maloney, 1976); afterward, it was indicated that the severity of dementia was correlated with the extent of cholinergic loss (Perry et al., 1981). Because one of the biochemical features of AD is modification by phosphorylation of the microtubule-associated protein tau (for review, see Avila et al., 2004), in this work we indicate the effect of ACh on tau phosphorylation at specific sites recognized by 12E8 and PThr50 antibodies in human neuroblastoma SH-SY5Y cells. Two sites in which modification might regulate the binding of tau to microtubules (Novak et al., 1991; Feijoo et al., 2004).

    Journal of molecular neuroscience : MN 2006;30;1-2;185-8

  • Increased levels of CSF phosphorylated tau in apolipoprotein E epsilon4 carriers with mild cognitive impairment.

    Buerger K, Teipel SJ, Zinkowski R, Sunderland T, Andreasen N, Blennow K, Ewers M, DeBernardis J, Shen Y, Kerkman D, Du Y and Hampel H

    Dementia Research Section and Memory Clinic, Alzheimer Memorial Center and Geriatric Psychiatry Branch, Department of Psychiatry, Ludwig-Maximilian University, Nussbaumstrasse 7, 80336 Munich, Germany. katharina.buerger@med.uni-muenchen.de

    We investigated the correlation between the apolipoprotein E varepsilon4 allele (apoE epsilon4) carrier status, a major risk factor of Alzheimer's disease (AD), and levels of tau protein phosphorylated at threonine 231 (P-tau(231P)) in cerebrospinal fluid (CSF) in predementia and clinical stages of AD and healthy controls (HC). Thirty-one subjects with mild cognitive impairment (MCI) who had converted to AD during follow-up were included, as well as 71 AD patients, and 29 HC subjects. In MCI, but not in AD and HC, CSF P-tau(231P) levels were significantly higher in apoE epsilon4 carriers compared to non-carriers (p<0.001). Controlling for disease duration, the apoE epsilon4 effect on P-tau(231P) remained significant. Our study indicates that the apoE epsilon4 carrier status should be considered when CSF P-tau(231P) is evaluated as biomarker candidate of AD in MCI subjects.

    Neuroscience letters 2005;391;1-2;48-50

  • Different tau epitopes define Abeta42-mediated tau insolubility.

    Pennanen L and Götz J

    Division of Psychiatry Research, University of Zürich, August Forel Street 1, 8008 Zürich, Switzerland.

    Alzheimer's disease (AD) is characterized by extracellular beta-amyloid (Abeta(42))-containing plaques and intracellular neurofibrillary tangles. The latter are composed of hyperphosphorylated filamentous aggregates of the microtubule-associated protein tau. Previously we demonstrated pathological interactions between these two histopathological hallmarks using human SH-SY5Y neuroblastoma cells overexpressing wild-type and mutant forms of human tau. Exposure to pre-aggregated forms of Abeta(42) caused both the formation of AD-like tau-containing filaments and a decreased solubility of tau, both of which were prevented by mutating the S422 phospho-epitope of tau. Here, we expressed additional tau mutants in SH-SY5Y cells to assess the role of phosphorylation and cleavage sites of tau in tau aggregation. We found that the Abeta(42)-mediated decrease in tau solubility depends on the interplay of distinct phospho-epitopes of tau and not only on phosphorylation of the S422 epitope.

    Biochemical and biophysical research communications 2005;337;4;1097-101

  • Accelerated amyloid deposition, neurofibrillary degeneration and neuronal loss in double mutant APP/tau transgenic mice.

    Ribé EM, Pérez M, Puig B, Gich I, Lim F, Cuadrado M, Sesma T, Catena S, Sánchez B, Nieto M, Gómez-Ramos P, Morán MA, Cabodevilla F, Samaranch L, Ortiz L, Pérez A, Ferrer I, Avila J and Gómez-Isla T

    Departmento de Neurología, Universidad de Navarra, Pamplona, Navarra, Spain.

    Even though the idea that amyloid beta peptide accumulation is the primary event in the pathogenesis of Alzheimer's disease has become the leading hypothesis, the causal link between aberrant amyloid precursor protein processing and tau alterations in this type of dementia remains controversial. We further investigated the role of beta-amyloid production/deposition in tau pathology and neuronal cell death in the mouse brain by crossing Tg2576 and VLW lines expressing human mutant amyloid precursor protein and human mutant tau, respectively. The resulting double transgenic mice showed enhanced amyloid deposition accompanied by neurofibrillary degeneration and overt neuronal loss in selectively vulnerable brain limbic areas. These findings challenge the idea that tau pathology in Alzheimer's disease is merely a downstream effect of amyloid production/deposition and suggest that reciprocal interactions between beta-amyloid and tau alterations may take place in vivo.

    Neurobiology of disease 2005;20;3;814-22

  • Familial autosomal dominant cortico-basal degeneration with the P301S mutation in the tau gene: an example of phenotype variability.

    Casseron W, Azulay JP, Guedj E, Gastaut JL and Pouget J

    Journal of neurology 2005;252;12;1546-8

  • Familial frontotemporal dementia associated with the novel MAPT mutation T427M.

    Giaccone G, Rossi G, Farina L, Marcon G, Di Fede G, Catania M, Morbin M, Sacco L, Bugiani O and Tagliavini F

    Journal of neurology 2005;252;12;1543-5

  • GSK3B polymorphisms alter transcription and splicing in Parkinson's disease.

    Kwok JB, Hallupp M, Loy CT, Chan DK, Woo J, Mellick GD, Buchanan DD, Silburn PA, Halliday GM and Schofield PR

    Garvan Institute of Medical Research, University of New South Wales, Barker Street, Randwick, Sydney NSW 2031, Australia.

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by a combination of motor symptoms. We identified two functional single nucleotide polymorphisms in the glycogen synthase kinase-3beta gene (GSK3B). A promoter single nucleotide polymorphism (rs334558) is associated with transcriptional strength in vitro in which the T allele has greater activity. An intronic single nucleotide polymorphism (rs6438552) regulates selection of splice acceptor sites in vitro. The T allele is associated with altered splicing in lymphocytes and increased levels of GSK3B transcripts that lack exons 9 and 11 (GSKDeltaexon9+11). Increased levels of GSKDeltaexon9+11 correlated with enhanced phosphorylation of its substrate, Tau. In a comparison of PD and control brains, there was increased in frequency of T allele (rs6438552) and corresponding increase in GSKDeltaexon9+11 and Tau phosphorylation in PD brains. Conditional logistic regression indicated gene-gene interaction between T/T genotype of rs334558 and H1/H1 haplotype of microtubule-associated protein Tau (MAPT) gene (p = 0.009). There was association between a haplotype (T alleles of both GSK3B polymorphisms) and disease risk after stratification by Tau haplotypes ((H1/H2+H2/H2 individuals: odds ratio, 1.64; p = 0.007; (H1/H1 individuals: odds ratio, 0.68; p < 0.001). Ours results suggest GSK3B polymorphisms alter transcription and splicing and interact with Tau haplotypes to modify disease risk in PD.

    Annals of neurology 2005;58;6;829-39

  • Over-expression of tau results in defective synaptic transmission in Drosophila neuromuscular junctions.

    Chee FC, Mudher A, Cuttle MF, Newman TA, MacKay D, Lovestone S and Shepherd D

    School of Biological Sciences, University of Southampton, Bassett Crescent East Southampton, SO16 7PX, UK. fcc@soton.ac.uk

    We have shown that over-expression of human tau (0N3R) in Drosophila larval motor neurons causes significant morphological and functional disruption to the neuromuscular junctions (NMJs). Tau-expressing NMJs are reduced in size with irregular and abnormal bouton structure. Immunocytochemical analysis shows that the abnormal NMJs still retain synaptotagmin expression and form active zones. Functionally, the NMJs exhibit abnormal endo/exocytosis as revealed by incorporation of the styryl dye FM1-43. Electrophysiological studies showed that with low frequency stimulation (1 Hz), evoked synaptic potentials produced from tau over-expressing motor neurons were indistinguishable from wild type, however, following high frequency stimulation (50 Hz), evoked synaptic potentials were significantly decreased. Analysis of the number and distribution of mitochondria showed that motor neurons over-expressing tau had a significant reduction in functional mitochondria in the presynaptic terminal. Collapsing the mitochondrial membrane potential in wild type larvae phenocopied the effects of tau over-expression on synaptic transmission. Our results demonstrate that tau over-expression in vivo cause a synaptic dysfunction, which may be caused by a reduced complement of functional mitochondria.

    Funded by: Wellcome Trust

    Neurobiology of disease 2005;20;3;918-28

  • Phenotypic heterogeneity within a new family with the MAPT p301s mutation.

    Yasuda M, Nakamura Y, Kawamata T, Kaneyuki H, Maeda K and Komure O

    Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Japan. minor24@med.kobe-u.ac.jp

    Mutations in the gene encoding the microtubule-associated protein tau (MAPT) cause frontotemporal dementia and parkinsonism linked to chromosome 17. Clinical variability is seen not only among families with different mutations, but also among family members with the same mutation. We investigated a newly identified familial frontotemporal dementia and parkinsonism family. The disease was of early onset and was inherited as an autosomal dominant trait. Clinically, parkinsonism was the prominent and often early feature, and it preceded dementia. Three autopsied cases shared involvement predominantly in the frontal and temporal lobes and also in the subcortical nuclei, including substantia nigra, globus pallidus, and subthalamic nucleus, that microscopically consisted of neuronal loss, microvacuolation, and astrocytic fibrosis. Immunohistochemistry demonstrated neuropil threads, ballooned cells, and glial fibrillary tangles. Sequencing analysis of the MAPT gene showed an alteration in one allele, resulting in a P301S substitution. These findings suggest that the MAPT P301S mutation can cause pathologically subcortical-predominant, neuropil thread-rich, tau-containing lesions, which could result in consistent parkinsonism. Our study confirms the notion that the phenotype observed in affected individuals from P301S MAPT mutation families is heterogeneous and is broader than the phenotypes seen to date in affected family members carrying other MAPT mutations.

    Annals of neurology 2005;58;6;920-8

  • Progressive white matter pathology in the spinal cord of transgenic mice expressing mutant (P301L) human tau.

    Lin WL, Zehr C, Lewis J, Hutton M, Yen SH and Dickson DW

    Mayo Clinic College of Medicine, Jacksonville, Florida, 32224, USA.

    Transgenic mice expressing mutant (P301L) tau develop paresis, neurofibrillary tangles and neuronal loss in spinal motor neurons beginning at 4 to 6 months of age. Astrocytes and oligodendrocytes acquire filamentous tau inclusions at later ages. Here we report pathology in the spinal white matter of these animals. Progressive white matter pathology, detected as early as 2 months of age, was most marked in lateral and anterior columns, with sparing of posterior columns until late in the disease. Early changes in Luxol fast blue/periodic acid Schiff (LFB/PAS) and toluidine blue stained sections were vacuolation of myelin followed by accumulation of myelin figures within previous axonal tubes and finally influx of PAS-positive macrophages. Myelin debris and vacuoles were found in macrophages. At the ultrastructural level, myelinated axons showed extensive vacuolation of myelin sheaths formed by splitting of myelin lamellae at the intra-period line, while axons were atrophic and contained densely packed neurofilaments. Other axons were lost completely, resulting in collapse and phagocytosis of myelin sheaths. Also present were spheroids derived from swollen axons with thin myelin sheaths containing neurofilaments, tau filaments and degenerating organelles. Many oligodendrocytes had membrane-bound cytoplasmic bodies composed of tightly stacked lamellae capped by dense material. The vacuolar myelopathy in this model to some extent resembles that reported in acquired immune deficiency syndrome and vitamin B12 deficiency. The progressive axonal pathology is most consistent with a dying-back process caused by abnormal accumulation of tau in upstream neurons, while vacuolar myelinopathy may be a secondary manifestation of neuroinflammation.

    Funded by: NIA NIH HHS: P01-AG03949, P01-AG14449, P01-AG17216, P50-AG16574, R01-AG19734

    Journal of neurocytology 2005;34;6;397-410

  • Human protein tau represses DNA replication in vitro.

    Li W, Wang XS, Qu MH, Liu Y and He RQ

    The State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China.

    Here, in the experiments of both PCR and real-time PCR, a repression of DNA amplification was observed in the presence of protein tau. Furthermore, a strong repression appeared when an in vitro DNA replication assay was performed at the physiological temperature (37 degrees C). The incorporation of dNTP was markedly decreased to approximately 12% of control by the presence of tau23 and to approximately 15% by tau40. In the competitive experiments, the PCR product could be restored when the competitor DNA was added, indicating that the association of tau with the template gave rise to the repression. However, tau did not repress the yield of RNA in transcription, suggesting that tau was replaced or ejected from the template by the elongating T7 RNA polymerase.

    Biochimica et biophysica acta 2005;1726;3;280-6

  • High-density SNP haplotyping suggests altered regulation of tau gene expression in progressive supranuclear palsy.

    Rademakers R, Melquist S, Cruts M, Theuns J, Del-Favero J, Poorkaj P, Baker M, Sleegers K, Crook R, De Pooter T, Bel Kacem S, Adamson J, Van den Bossche D, Van den Broeck M, Gass J, Corsmit E, De Rijk P, Thomas N, Engelborghs S, Heckman M, Litvan I, Crook J, De Deyn PP, Dickson D, Schellenberg GD, Van Broeckhoven C and Hutton ML

    Department of Molecular Genetics, Flanders Interuniversity Institute for Biotechnology, University of Antwerp, Belgium.

    Two extended haplotypes exist across the tau gene-H1 and H2-with H1 consistently associated with increased risk of progressive supranuclear palsy (PSP). Using 15 haplotype tagging SNPs (htSNPs), capturing >95% of MAPT haplotype diversity, we performed association analysis in a US sample of 274 predominantly pathologically confirmed PSP patients and 424 matched control individuals. We found that PSP risk is associated with one of two major ancestral H1 haplotypes, H1B, increasing from 14% in control individuals to 22% in PSP patients (P<0.001). In young PSP patients, the H1B risk could be localized to a 22 kb regulatory region in intron 0 (P<0.001) and could be fully explained by one SNP, htSNP167, creating a LBP-1c/LSF/CP2 site, shown to regulate the expression of genes in other neurodegenerative disorders. Luciferase reporter data indicated that the 182 bp conserved regulatory region, in which htSNP167 is located, is transcriptionally active with both alleles differentially influencing expression. Further, we replicated the htSNP167 association in a second, independently ascertained US PSP patient-control sample. However, the htSNP association showed that H1 risk alone could not explain the overall differences in H1 and H2 frequencies in PSP patients and control individuals. Thus, risk variants on different H1 htSNP haplotypes and protective variants on H2 contribute to population risk for PSP.

    Funded by: NIA NIH HHS: AG 24030, P01 AG 17216

    Human molecular genetics 2005;14;21;3281-92

  • Linkage disequilibrium fine mapping and haplotype association analysis of the tau gene in progressive supranuclear palsy and corticobasal degeneration.

    Pittman AM, Myers AJ, Abou-Sleiman P, Fung HC, Kaleem M, Marlowe L, Duckworth J, Leung D, Williams D, Kilford L, Thomas N, Morris CM, Dickson D, Wood NW, Hardy J, Lees AJ and de Silva R

    Reta Lila Weston Institute of Neurological Studies, University College London, London, UK.

    Background: The haplotype H1 of the tau gene, MAPT, is highly associated with progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

    Objective: To investigate the pathogenic basis of this association.

    Methods: Detailed linkage disequilibrium and common haplotype structure of MAPT were examined in 27 CEPH trios using validated HapMap genotype data for 24 single nucleotide polymorphisms (SNPs) spanning MAPT.

    Results: Multiple variants of the H1 haplotype were resolved, reflecting a far greater diversity of MAPT than can be explained by the H1 and H2 clades alone. Based on this, six haplotype tagging SNPs (htSNPs) that capture 95% of the common haplotype diversity were used to genotype well characterised PSP and CBD case-control cohorts. In addition to strong association with PSP and CBD of individual SNPs, two common haplotypes derived from these htSNPs were identified that are highly associated with PSP: the sole H2 derived haplotype was underrepresented and one of the common H1 derived haplotypes was highly associated, with a similar trend observed in CBD. There were powerful and highly significant associations with PSP and CBD of haplotypes formed by three H1 specific SNPs. This made it possible to define a candidate region of at least approximately 56 kb, spanning sequences from upstream of MAPT exon 1 to intron 9. On the H1 haplotype background, these could harbour the pathogenic variants.

    Conclusions: The findings support the pathological evidence that underlying variations in MAPT could contribute to disease pathogenesis by subtle effects on gene expression and/or splicing. They also form the basis for the investigation of the possible genetic role of MAPT in Parkinson's disease and other tauopathies, including Alzheimer's disease.

    Funded by: Intramural NIH HHS; NIA NIH HHS: AG05128, P50 AG16570, P50-AG08671, U24 AG021886; NIMH NIH HHS: MH60451; NINDS NIH HHS: NS39764, P50-NS40256-06; Parkinson's UK: G-4029

    Journal of medical genetics 2005;42;11;837-46

  • Proteomic determination of widespread detergent-insolubility including Abeta but not tau early in the pathogenesis of Alzheimer's disease.

    Woltjer RL, Cimino PJ, Boutté AM, Schantz AM, Montine KS, Larson EB, Bird T, Quinn JF, Zhang J and Montine TJ

    Department of Pathology, Division of Neuropathology, University of Washington, Seattle, WA, USA.

    Biochemical characterization of the major detergent-insoluble proteins that comprise hallmark histopathologic lesions initiated the molecular era of Alzheimer's disease (AD) research. Here, we reinvestigated detergent-insoluble proteins in AD using modern proteomic techniques. Using liquid chromatography (LC)-mass spectrometry (MS)-MS-based proteomics, we robustly identified 125 proteins in the detergent-insoluble fraction of late-onset AD (LOAD) temporal cortex that included several proteins critical to Abeta production, components of synaptic scaffolding, and products of genes linked to an increased risk of LOAD; we verified 15 of 15 of these proteins by Western blot. Following multiple analyses, we estimated that these represent ~80% of detergent-insoluble proteins in LOAD detectable by our method. Abeta, tau, and 7 of 8 other newly identified detergent-insoluble proteins were disproportionately increased in temporal cortex from patients with LOAD and AD derived from mutations in PSEN1 and PSEN2; all of these except tau were elevated in individuals with prodromal dementia, while none except Abeta were elevated in aged APPswe mice. These results are consistent with the amyloid hypothesis of AD and extend it to include widespread protein insolubility, not exclusively Abeta insolubility, early in AD pathogenesis even before the onset of clinical dementia.

    Funded by: NIA NIH HHS: AG05136, AG06781, AG22040, AG23801, AG24011

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2005;19;13;1923-5

  • Disease-related modifications in tau affect the interaction between Fyn and Tau.

    Bhaskar K, Yen SH and Lee G

    Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.

    Microtubule-associated protein tau is the major component of the neurofibrillary tangles of Alzheimer disease (AD) and is genetically linked to frontotemporal dementias (FTDP-17). We have recently shown that tau interacts with the SH3 domain of Fyn, an Src family non-receptor tyrosine kinase, and is tyrosine-phosphorylated by Fyn on Tyr-18. Also, tyrosine-phosphorylated tau is present in the neuropathology of AD. To determine whether alterations in the tau-Fyn interaction might correlate with disease-related factors in AD and FTDP-17, we have performed real-time surface plasmon resonance studies on a panel of 21 tau constructs with Fyn SH3. We report that the interaction between Fyn SH3 and 3R-tau was 20-fold higher than that with 4R-tau. In addition, the affinity between 4R-tau and Fyn SH3 was increased 25-45-fold by phosphorylation-mimicking mutations or by FTDP-17 mutations. In vitro kinase reactions show that tau, with lower affinity SH3 interactions, exhibited a lower level of Tyr-18 phosphorylation under our reaction conditions. Lastly, we have demonstrated that tau is phosphorylated on Tyr-18 in the tau P301L mouse model for tauopathy (JNPL3). In summary, our results suggest that disease-related phosphorylation and missense mutations of tau increase association of tau with Fyn. Because these effects are mediated through the 4R component of the tau population, these results also have implications for the FTDP-17 diseases caused by increased expression of 4R-tau. Our data support a role for the Fyn-tau interaction in neurodegeneration.

    Funded by: NIA NIH HHS: AG17753

    The Journal of biological chemistry 2005;280;42;35119-25

  • Molecular motors implicated in the axonal transport of tau and alpha-synuclein.

    Utton MA, Noble WJ, Hill JE, Anderton BH and Hanger DP

    Department of Neuroscience, King's College London, Institute of Psychiatry, De Crespigny Park, London, SE5 8AF, UK.

    Tau and alpha-synuclein are both proteins implicated in the pathology of neurodegenerative disease. Here we have investigated the mechanisms of axonal transport of tau and alpha-synuclein, because failure of axonal transport has been implicated in the development of several neurodegenerative disorders. We found that the transport of both of these proteins depend on an intact microtubule- but not actin-cytoskeleton, and that tau and alpha-synuclein both move at overall slow rates of transport. We used time-lapse video microscopy to obtain images of live neurons that had been transfected with plasmids expressing proteins tagged with enhanced green fluorescent protein. We found that particulate structures containing tau or alpha-synuclein travel rapidly when moving along axons but spend the majority of the time paused, and these structures have similar characteristics to those previously observed for neurofilaments. The motile particles containing tau or alpha-synuclein colocalise with the fast-transporting molecular motor kinesin-1 in neurons. Co-immunoprecipitation experiments demonstrate that tau and alpha-synuclein are each associated with complexes containing kinesin-1, whereas only alpha-synuclein appears to interact with dynein-containing complexes. In vitro glutathione S-transferase-binding assays using rat brain homogenate or recombinant protein as bait reveals a direct interaction of kinesin-1 light chains 1 and 2 with tau, but not with alpha-synuclein. Our findings suggest that the axonal transport of tau occurs via a mechanism utilising fast transport motors, including the kinesin family of proteins, and that alpha-synuclein transport in neurons may involve both kinesin and dynein motor proteins.

    Journal of cell science 2005;118;Pt 20;4645-54

  • Altered depression-related behavior and neurochemical changes in serotonergic neurons in mutant R406W human tau transgenic mice.

    Egashira N, Iwasaki K, Takashima A, Watanabe T, Kawabe H, Matsuda T, Mishima K, Chidori S, Nishimura R and Fujiwara M

    Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.

    Mutant R406W human tau was originally identified in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) and causes a hereditary tauopathy that clinically resembles Alzheimer's disease (AD). In the current study, we examined the performance of R406W transgenic (Tg) mice in the forced swimming test, a test with high predictivity of antidepressant efficacy in human depression, and found an enhancement of the immobility time. In contrast, the motor function and anxiety-related emotional response of R406W Tg mice were normal. Furthermore, a selective serotonin reuptake inhibitor (SSRI), fluvoxamine (100 mg/kg, p.o.), significantly reduced this enhancement of the immobility time, whereas a noradrenaline reuptake inhibitor, desipramine, had no effect. In an in vivo microdialysis study, R406W Tg mice exhibited a significantly decreased extracellular 5-hydroxyindoleacetic acid (5-HIAA) level in the frontal cortex and also exhibited a tendency toward a decreased extracellular 5-hydroxytryptamine (5-HT) level. Moreover, fluvoxamine, which reduced the enhancement of the immobility time, significantly increased the extracellular 5-HT level in R406W Tg mice. These results suggest that R406W Tg mice exhibit changes in depression-related behavior involving serotonergic neurons and provide an animal model for investigating AD with depression.

    Brain research 2005;1059;1;7-12

  • Axonal degeneration induced by targeted expression of mutant human tau in oligodendrocytes of transgenic mice that model glial tauopathies.

    Higuchi M, Zhang B, Forman MS, Yoshiyama Y, Trojanowski JQ and Lee VM

    Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Institute on Aging, University of Pennsylvania, Philadelphia, Pennsylvania 19104.

    Abundant filamentous tau inclusions in oligodendrocytes (OLGs) are hallmarks of neurodegenerative tauopathies, including sporadic corticobasal degeneration and hereditary frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). However, mechanisms of neurodegeneration in these tauopathies are unclear in part because of the lack of animal models for experimental analysis. We address this by generating transgenic (Tg) mice expressing human tau exclusively in OLGs using the 2',3'-cyclic nucleotide 3'-phosphodiesterase promoter. Filamentous OLG tau inclusions developed in these Tg mice as a result of human tau expression in OLGs, especially those expressing the FTDP-17 human P301L mutant tau. Notably, structural disruption of myelin and axons preceded the emergence of thioflavin-S positive tau inclusions in OLGs, but impairments in axonal transport occurred even earlier, whereas motor deficits developed subsequently, especially in Tg mice with the highest tau expression levels. These data suggest that the accumulation of tau in OLG cause neurodegeneration, and we infer they do so by disrupting axonal transport. We suggest that similar defects may also occur in sporadic and hereditary human tauopathies with OLG tau pathologies.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2005;25;41;9434-43

  • Identification, expression analysis, genomic organization and cellular location of a novel protein with a RhoGEF domain.

    Tse SW, Broderick JA, Wei ML, Luo MH, Smith D, McCaffery P, Stamm S and Andreadis A

    Department of Biomedical Sciences, E.K. Shriver Center for Mental Retardation, Waltham, MA 02452, USA.

    In this study we describe the identification and characterization of a novel cytosolic protein of the guanine exchange factor (GEF) family. The human cDNA corresponds to predicted human protein FLJ00128/FLJ10357 located on chromosome 14q11.2. The deduced protein sequence contains in its C-terminus a RhoGEF domain followed by a pleckstrin domain. Its N-terminus, central region and RhoGEF/pleckstrin domain are homologous to the recently identified zebrafish Quattro protein, which is involved in morphogenetic movements mediated by the actin cytoskeleton. Based on the homology of our protein's RhoGEF domain to the RhoGEF domains of Trio, Duo and Duet and its homology with Quattro, we named it Solo. The Solo mRNA is ubiquitously expressed but enriched in brain, its expression peaks perinatally and it undergoes extensive alternative splicing. In both myoblasts and neuroblastoma cells, the Solo protein is concentrated around the nucleus.

    Funded by: NICHD NIH HHS: HD05515

    Gene 2005;359;63-72

  • Presymptomatic semantic impairment in a case of fronto-temporal lobar degeneration associated with the +16 mutation in MAPT.

    Garrard P and Carroll E

    Institute of Cognitive Neuroscience, University College, London, UK. p.gerrard@ucl.ac.uk

    We describe a patient who came to neurological attention because of his at-risk status for the +16 exon 10 splice mutation in the tau gene (microtubule associated protein tau, MAPT), which had given rise to progressive behavioural disturbances in two of his siblings. The patient began to exhibit early signs of behavioural disturbance at around the age of symptom onset in both of his siblings. Although he did not spontaneously complain of difficulties in the domain of language, he met clinical, radiological and neuropsychological criteria for semantic dementia. On the assumption that his illness is mediated by the same pathological process as those of his siblings, we propose that this clinical picture represents the earliest changes of a semantic impairment - a phase of the illness that is often retrospectively described by patients and their relations, but has never previously been documented at first hand. Although typical of semantic dementia in many respects, the illness had several interesting and atypical features that emerged on detailed testing: first, he exhibited no insight into his difficulties; secondly, progression over a twelve-month interval was unusually slow; thirdly, he evinced a striking and consistent advantage for nonliving over living concepts; fourthly, a differential impairment of distinctive over shared knowledge did not emerge except when items that he could still name were compared with those for which he was anomic. Finally, the availability of post mortem pathological analysis from the brains of both of his affected siblings allowed us to attribute his illness to a specific pathological process which is considered unusual for patients with this clinical phenotype.

    Neurocase 2005;11;5;371-83

  • Frequency of a tau genotype in amyotrophic lateral sclerosis.

    Münch C, Prechter F, Xu R, Linke P, Prudlo J, Kuzma M, Kwiecinski H, Ludolph AC and Meyer T

    Department of Neurology, Jewish Hospital, Heinz-Galinski-Strasse 1, 13347 Berlin, Germany. muench@jkb-online.de

    We investigated the susceptibility of the dinucleotide polymorphism A0 in the tau gene to amyotrophic lateral sclerosis (ALS). In 416 unrelated patients with ALS and 242 control subjects the A0/A0 genotype was not associated with the pooled sample of ALS cases. Subgroup analysis revealed that in sporadic ALS the A0 polymorphism was significantly overrepresented. There was no association of the A0/A0 genotype with the age and site of disease onset or the presence of dementia. The studied tau genotype may contribute to the multifactorial genetic background of ALS.

    Journal of the neurological sciences 2005;236;1-2;13-6

  • Phosphorylation of FTDP-17 mutant tau by cyclin-dependent kinase 5 complexed with p35, p25, or p39.

    Sakaue F, Saito T, Sato Y, Asada A, Ishiguro K, Hasegawa M and Hisanaga S

    Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Hachiohji, Tokyo 192-039, Japan.

    One of the major pathological hallmarks of Alzheimer disease is neurofibrillary tangles. Neurofibrillary tangles are bundles of paired helical filaments composed of hyperphosphorylated tau. Cyclin-dependent kinase 5 (Cdk5) is one of the tau protein kinases that increase paired helical filament epitopes in tau by phosphorylation. Recently, various mutations of tau have been identified in frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17). Here, we investigated the phosphorylation of FTDP-17 mutant tau proteins, K257T, P301L, P301S, and R406W, by Cdk5 complexed with p35, p25, or p39 in vitro and in cultured cells. The extent of phosphorylation by all Cdk5 species was slightly lower in mutant tau than in wild-type tau. Major phosphorylation sites, including Ser202, Ser235, and Ser404, were the same among the wild-type, K257T, P301L, and P301S tau proteins phosphorylated by any Cdk5. On the other hand, R406W tau was less phosphorylated at Ser404 than were the other variants. This was not due to the simple replacement of amino acid Arg406 with Trp close to the phosphorylation site, because Ser404 in a R406W peptide was equally phosphorylated in a wild-type peptide. The decreased phosphorylation of mutant tau by Cdk5s was canceled when tau protein bound to microtubules was phosphorylated. These results indicate that FTDP-17 mutations do not affect the phosphorylatability of tau by Cdk5 complexed with p35, p25, or p39 and may explain part of the discrepancy reported previously between in vivo and in vitro phosphorylation of FTDP-17 tau mutants.

    The Journal of biological chemistry 2005;280;36;31522-9

  • A new mutation of the tau gene, G303V, in early-onset familial progressive supranuclear palsy.

    Ros R, Thobois S, Streichenberger N, Kopp N, Sánchez MP, Pérez M, Hoenicka J, Avila J, Honnorat J and de Yébenes JG

    Banco de Tejidos para Investigaciones Neurológicas, Universidad Autónoma de Madrid, Spain.

    Background: Progressive supranuclear palsy (PSP) is a clinicopathological syndrome related to tau deposits and in linkage disequilibrium with tau polymorphisms. Some rare familial PSP cases have been related to tau gene mutations.

    Objective: To present the clinical, pathological, and molecular data of one family with early-onset autosomal dominant PSP.

    Design: We performed clinical examinations, quantitative neurological tests, positron emission tomographic scans with fluorodopa F 18 and raclopride C 11, analysis of tau mutations, neuropathological examinations, and protein analyses on brain specimens.

    Results: Three family members had PSP confirmed by pathological features in the proband. A novel mutation of tau, G303V, was found in the proband and other family members. tau Isoforms with 4 microtubule-binding repeats were overexpressed in the proband brain.

    Conclusions: The G303V mutation of tau is associated with autosomal dominant PSP. Expression of 4 microtubule-binding repeat tau isoforms is increased in the proband.

    Archives of neurology 2005;62;9;1444-50

  • Individual and regional variations of phospho-tau species in progressive supranuclear palsy.

    Puig B, Rey MJ and Ferrer I

    Institut de Neuropatologia, Servei Anatomia Patològica, Hospital Universitari de Bellvitge, carrer Feixa Llarga sn, 08907 Hospitalet de Llobregat, Spain.

    The purpose of this study was to learn about possible variations in phospho-tau profiles in terms of case-to-case differences, regional modifications and diversification of tau phosphorylation sites in five PSP cases with moderate to severe frontosubcortical dysfunction. Gel electrophoresis of sarkosyl-insoluble fractions and Western blotting with five anti-tau phospho-specific antibodies directed to phosphorylation sites Thr181, Ser202, Ser214, Ser396 and Ser422 were used to study four brain regions including frontal cortex, area 8, subcortical white matter of the frontal lobe, caudate/putamen: striatum, and basis pontis: pons. Although two bands of 66 and 62 kDa were observed in almost every region in each case, the intensity of the bands depends on the anti-tau phospho-specific antibody. More importantly, bands of 72, 50/55 and 37 kDa were commonly found in PSP brains, whereas other bands of about 60, 42, 33 and 29 kDa were irregularly observed. The pattern of bands differed slightly from one case to another and from one region to another. Moreover, the phospho-tau profile differed depending on the anti-tau phospho-specific antibody used. These data suggest that several species of tau are variably phosphorylated at a given time in a given region (and probably in a given cell), and that tau aggregates are composed of several phosphorylated truncated or cleaved tau molecules, in addition to phosphorylated complete tau isoforms.

    Acta neuropathologica 2005;110;3;261-8

  • Phosphorylation of tau at serine 416 by Ca2+/calmodulin-dependent protein kinase II in neuronal soma in brain.

    Yamamoto H, Hiragami Y, Murayama M, Ishizuka K, Kawahara M and Takashima A

    Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan. hideyuki@gpo.kumamoto-u.ac.jp

    It is well known that tau is a good in vitro substrate for Ca2+/calmodulin-dependent protein kinase II (CaM kinase II). However, it is not clear at present whether CaM kinase II phosphorylates tau in vivo or not. Serine 416, numbered according to the longest human tau isoform, has been reported to be one of the major phosphorylation sites by CaM kinase II in vitro. In this study, we produced a specific antibody against tau phosphorylated at serine 416 (PS416-tau). Immunoblot analysis revealed that the antibody reacted with tau in the rat brain extract which was prepared in the presence of protein phosphatase inhibitors. Developmental study indicated that serine 416 was strongly phosphorylated at early developmental stages in rat brain. We examined the localization of PS416-tau in primary cultured hippocampal neurons and the immortalized GnRH neurons (GT1-7 cells), which were stably transfected with CaM kinase IIalpha cDNA. Immunostaining of these cells indicated that tau was phosphorylated mainly in neuronal soma. Interestingly, tau in neuronal soma in Alzheimer's disease (AD) brain was strongly immunostained by the antibody. These results suggest that CaM kinase II is involved in the accumulation of tau in neuronal soma in AD brain.

    Journal of neurochemistry 2005;94;5;1438-47

  • Identification and isolation of a hyperphosphorylated, conformationally changed intermediate of human protein tau expressed in yeast.

    Vandebroek T, Vanhelmont T, Terwel D, Borghgraef P, Lemaire K, Snauwaert J, Wera S, Van Leuven F and Winderickx J

    Experimental Genetics Group, Leuven, Belgium.

    Hyperphosphorylation and aggregation of protein tau are typical for neurodegenerative tauopathies, including Alzheimer's disease (AD). We demonstrate here that human tau expressed in yeast acquired pathological phosphoepitopes, assumed a pathological conformation, and formed aggregates. These processes were modulated by yeast kinases Mds1 and Pho85, orthologues of GSK-3beta and cdk5, respectively. Surprisingly, inactivation of Pho85 increased phosphorylation of tau-4R, concomitant with increased conformational change defined by antibody MC1 and a 40-fold increase in aggregation. Soluble protein tau, purified from yeast lacking PHO85, spontaneously and rapidly formed tau filaments in vitro. Further fractionation of tau by anion-exchange chromatography yielded a hyperphosphorylated monomeric subfraction, termed hP-tau/MC1, with slow electrophoretic mobility and enriched with all major epitopes, including MC1. Isolated hP-tau/MC1 vastly accelerated in vitro aggregation of wild-type tau-4R, demonstrating its functional capacity to initiate aggregation, as well as its structural stability. Combined, this novel yeast model recapitulates hyperphosphorylation, conformation, and aggregation of protein tau, provides insight in molecular changes crucial in tauopathies, offers a source for isolation of modified protein tau, and has potential for identification of modulating compounds and genes.

    Biochemistry 2005;44;34;11466-75

  • 14-3-3Zeta does not increase GSK3beta-mediated tau phosphorylation in cell culture models.

    Matthews TA and Johnson GV

    Department of Psychiatry, School of Medicine, 1720 7th Avenue South, SC1061, University of Alabama at Birmingham, Birmingham, AL 35294-0017, USA.

    Tau is a neuronal microtubule-associated protein whose function is regulated by site-specific phosphorylation. One protein kinase that is likely to play an important role in regulating the phosphorylation state of tau in vivo is glycogen synthase kinase (GSK) 3beta. The activity of GSK3beta is regulated by specific protein-protein interactions and 14-3-3zeta, a member of a protein family that can act as scaffolds, was recently reported to co-purify with GSK3beta in a large protein complex that was isolated from bovine brain [A. Agarwal-Mawal, H.Y. Qureshi, P.W. Cafferty, Z. Yuan, D. Han, R. Lin, H.K. Paudel, 14-3-3 connects glycogen synthase kinase-3 beta to tau within a brain microtubule-associated tau phosphorylation complex, J. Biol. Chem. 278 (2003) 12722-12728]. The purpose of this study was to determine if 14-3-3zeta could act as a scaffolding protein to promote the interaction of GSK3beta with tau and subsequently, enhance GSK3beta-mediated tau hyperphosphorylation. We used cell culture models, immunoprecipitation, and Western blotting to examine the interaction of GSK3beta and 14-3-3zeta with both exogenously and endogenously expressed proteins. We found that GSK3beta, 14-3-3zeta and tau do not interact in these cellular models under our experimental conditions and that GSK3beta-mediated tau phosphorylation is not effected by the presence of 14-3-3zeta. These data indicate that 14-3-3zeta may not be directly interacting with GSK3beta and tau in the brain, but may indirectly facilitate the interactions by binding to other proteins.

    Funded by: NINDS NIH HHS: NS35060, NS41744

    Neuroscience letters 2005;384;3;211-6

  • Synthesis and conformational properties of phosphopeptides related to the human tau protein.

    Du JT, Li YM, Ma QF, Qiang W, Zhao YF, Abe H, Kanazawa K, Qin XR, Aoyagi R, Ishizuka Y, Nemoto T and Nakanishi H

    Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, PR China.

    In the brains of Alzheimer's disease patients, the tau protein dissociates from the axonal microtubule and abnormally aggregates to form a paired helical filament (PHF). One of the priorities in Alzheimer research is to determine the effects of abnormal phosphorylation on the local structure. A series of peptides corresponding to isolated regions of tau protein have been successfully synthesized using Fmoc-based chemistry and their conformations were determined by 1H NMR spectroscopy and circular dichroism (CD) spectroscopy. Immunodominant peptides corresponding to tau-(256-273), tau-(350-367) and two phosphorylated derivatives in which a single Ser was phosphorylated at positions 262 and 356, respectively, were the main focus of the study. A direct alteration of the local structure after phosphorylation constitutes a new strategy through which control of biological activity can be enforced. In our study on Ser262 in R1 peptide and Ser356 in R4 peptide, phosphorylation modifies both the negative charge and the local conformation nearby the phosphorylation sites. Together, these structural changes indicate that phosphorylation may act as a conformational switch in the binding domain of tau protein to alter specificity and affinity of binding to microtubule, particularly in response to the abnormal phosphorylation events associated with Alzheimer's disease.

    Regulatory peptides 2005;130;1-2;48-56

  • Evidence suggesting that Homo neanderthalensis contributed the H2 MAPT haplotype to Homo sapiens.

    Hardy J, Pittman A, Myers A, Gwinn-Hardy K, Fung HC, de Silva R, Hutton M and Duckworth J

    Laboratory of Neurogenetics, National Institutes on Aging and National Institutes of Neurological Diseases and Stroke, National Institutes of Health, 35 Convent Drive, Bethesda, MD 20892, USA. hardyj@mail.nih.gov

    The tau (MAPT) locus exists as two distinct clades, H1 and H2. The H1 clade has a normal linkage disequilibrium structure and is the only haplotype found in all populations except those derived from Caucasians. The H2 haplotype is the minor haplotype in Caucasian populations and is not found in other populations. It shows no recombination over a region of 2 Mb with the more common H1 haplotype. The distribution of the haplotype and analysis of the slippage of dinucleotide repeat markers within the haplotype suggest that it entered Homo sapiens populations between approx. 10000 and 30000 years ago. However, sequence comparison of the H2 haplotype with the H1 haplotype and with the chimp sequence suggests that the common founder of the H1 and H2 haplotypes was far earlier than this. We suggest that the H2 haplotype is derived from Homo neanderthalensis and entered H. sapiens populations during the co-existence of these species in Europe from approx. 45000 to 18000 years ago and that the H2 haplotype has been under selection pressure since that time, possibly because of the role of this H1 haplotype in neurodegenerative disease.

    Biochemical Society transactions 2005;33;Pt 4;582-5

  • Tau suppression in a neurodegenerative mouse model improves memory function.

    Santacruz K, Lewis J, Spires T, Paulson J, Kotilinek L, Ingelsson M, Guimaraes A, DeTure M, Ramsden M, McGowan E, Forster C, Yue M, Orne J, Janus C, Mariash A, Kuskowski M, Hyman B, Hutton M and Ashe KH

    Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.

    Neurofibrillary tangles (NFTs) are the most common intraneuronal inclusion in the brains of patients with neurodegenerative diseases and have been implicated in mediating neuronal death and cognitive deficits. Here, we found that mice expressing a repressible human tau variant developed progressive age-related NFTs, neuronal loss, and behavioral impairments. After the suppression of transgenic tau, memory function recovered, and neuron numbers stabilized, but to our surprise, NFTs continued to accumulate. Thus, NFTs are not sufficient to cause cognitive decline or neuronal death in this model of tauopathy.

    Funded by: NIA NIH HHS: P01 AG015453, P01-AG15453, P50 AG005134, R01 AG008487, R01 AG026249, R01 AG026252, R01-AG08487, R01-AG26249, T31-AG00277; NINDS NIH HHS: R01 NS033249, R01 NS046355, R01 NS082672, R01-NS46355; PHS HHS: R01-026252

    Science (New York, N.Y.) 2005;309;5733;476-81

  • Tyrosine 394 is phosphorylated in Alzheimer's paired helical filament tau and in fetal tau with c-Abl as the candidate tyrosine kinase.

    Derkinderen P, Scales TM, Hanger DP, Leung KY, Byers HL, Ward MA, Lenz C, Price C, Bird IN, Perera T, Kellie S, Williamson R, Noble W, Van Etten RA, Leroy K, Brion JP, Reynolds CH and Anderton BH

    Department of Neuroscience, Institute of Psychiatry, King's College London, London SE5 8AF, United Kingdom.

    Tau is a major microtubule-associated protein of axons and is also the principal component of the paired helical filaments (PHFs) that comprise the neurofibrillary tangles found in Alzheimer's disease and other tauopathies. Besides phosphorylation of tau on serine and threonine residues in both normal tau and tau from neurofibrillary tangles, Tyr-18 was reported to be a site of phosphorylation by the Src-family kinase Fyn. We examined whether tyrosine residues other than Tyr-18 are phosphorylated in tau and whether other tyrosine kinases might phosphorylate tau. Using mass spectrometry, we positively identified phosphorylated Tyr-394 in PHF-tau from an Alzheimer brain and in human fetal brain tau. When wild-type human tau was transfected into fibroblasts or neuroblastoma cells, treatment with pervanadate caused tau to become phosphorylated on tyrosine by endogenous kinases. By replacing each of the five tyrosines in tau with phenylalanine, we identified Tyr-394 as the major site of tyrosine phosphorylation in tau. Tyrosine phosphorylation of tau was inhibited by PP2 (4-amino-5-(4-chlorophenyl-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), which is known to inhibit Src-family kinases and c-Abl. Cotransfection of tau and kinases showed that Tyr-18 was the major site for Fyn phosphorylation, but Tyr-394 was the main residue for Abl. In vitro, Abl phosphorylated tau directly. Abl could be coprecipitated with tau and was present in pretangle neurons in brain sections from Alzheimer cases. These results show that phosphorylation of tau on Tyr-394 is a physiological event that is potentially part of a signal relay and suggest that Abl could have a pathogenic role in Alzheimer's disease.

    Funded by: Wellcome Trust

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2005;25;28;6584-93

  • Importance of local structures of second and third repeat fragments of microtubule-binding domain for tau filament formation.

    Tokimasa M, Minoura K, Hiraoka S, Tomoo K, Sumida M, Taniguchi T and Ishida T

    Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.

    To investigate the importance of the seventh residue of the second and third repeat fragments (R2 and R3 peptides) of the microtubule-binding domain (MBD) for tau filamentous assembly, the residues Lys and Pro were substituted (R2-K7P and R3-P7K). The filament formations of the R2 and R3 peptides were almost lost due to their substitutions despite their overall conformational similarities. The NOE analyses showed the importance of the conformational flexibility for the R2 peptide and the coupled extended and helical conformations for the R3 peptide in their limited N-terminal regions around their seventh residues. The result shows that the filament formation of MBD is initiated from a short fragment region containing the minimal conformational or functional motif.

    FEBS letters 2005;579;17;3481-6

  • Sites of tau important for aggregation populate {beta}-structure and bind to microtubules and polyanions.

    Mukrasch MD, Biernat J, von Bergen M, Griesinger C, Mandelkow E and Zweckstetter M

    Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.

    The aggregation of the microtubule-associated tau protein and formation of "neurofibrillary tangles" is one of the hallmarks of Alzheimer disease. The mechanisms underlying the structural transition of innocuous, natively unfolded tau to neurotoxic forms and the detailed mechanisms of binding to microtubules are largely unknown. Here we report the high-resolution characterization of the repeat domain of soluble tau using multidimensional NMR spectroscopy. NMR secondary chemical shifts detect residual beta-structure for 8-10 residues at the beginning of repeats R2-R4. These regions correspond to sequence motifs known to form the core of the cross-beta-structure of tau-paired helical filaments. Chemical shift perturbation studies show that polyanions, which promote paired helical filament aggregation, as well as microtubules interact with tau through positive charges near the ends of the repeats and through the beta-forming motifs at the beginning of repeats 2 and 3. The high degree of similarity between the binding of polyanions and microtubules supports the hypothesis that stable microtubules prevent paired helical filament formation by blocking the tau-polyanion interaction sites, which are crucial for paired helical filament formation.

    The Journal of biological chemistry 2005;280;26;24978-86

  • Sequestosome 1/p62 shuttles polyubiquitinated tau for proteasomal degradation.

    Babu JR, Geetha T and Wooten MW

    Department of Biological Sciences, Program in Cell and Molecular Biosciences, Auburn University, AL 36849, USA.

    Inclusions isolated from several neurodegenerative diseases, including Alzheimer's disease (AD), are characterized by ubiquitin-positive proteinaceous aggregates. Employing confocal and immunoelectron microscopy, we find that the ubiquitin-associating protein sequestosome1/p62, co-localizes to aggregates isolated from AD but not control brain, along with the E3 ubiquitin ligase, TRAF6. This interaction could be recapitulated by co-transfection in HEK293 cells. Employing both in vitro and in vivo approaches, tau was found to be a substrate of the TRAF6, possessing lysine 63 polyubiquitin chains. Moreover, tau recovered from brain of TRAF6 knockout mice, compared with wild type, was not ubiquitinated. Tau degradation took place through the ubiquitin-proteasome pathway and was dependent upon either the K63-polyubiquitin chains or upon p62. In brain lysates of p62 knockout mice, tau fails to co-interact with Rpt1, a proteasomal subunit, thereby indicating a requirement for p62 shuttling of tau to the proteasome. Our results demonstrate that p62 interacts with K63-polyubiquitinated tau through its UBA domain and serves a novel role in regulating tau proteasomal degradation. We propose a model whereby either a decline in p62 expression or a decrease in proteasome activity may contribute to accumulation of insoluble/aggregated K63-polyubiquitinated tau.

    Funded by: NINDS NIH HHS: NS-33661

    Journal of neurochemistry 2005;94;1;192-203

  • Quantitative analysis of tau isoform transcripts in sporadic tauopathies.

    Connell JW, Rodriguez-Martin T, Gibb GM, Kahn NM, Grierson AJ, Hanger DP, Revesz T, Lantos PL, Anderton BH and Gallo JM

    Department of Neuroscience, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK.

    A number of neurodegenerative diseases, including Alzheimer's disease (AD), are characterized by intraneuronal accumulation of the tau protein. Some forms of FTDP-17 are caused by mutations in the tau gene affecting exon 10 splicing. Therefore, dysregulation of tau pre-mRNA splicing may be a contributing factor to sporadic tauopathies. To address this question, we devised a real-time RT-PCR strategy based on the use of a single fluorogenic probe to evaluate the ratio between tau isoforms containing or lacking exon 10 (4R/3R ratio) in post-mortem brain samples. We found a two- to six-fold increase in the 4R/3R ratio in cases of FTDP-17 linked to a splice site mutation, hence confirming the validity of the strategy. The difference in the 4R/3R ratio in the superior temporal and superior frontal gyri between AD and control brains was not statistically significant. Similarly, there was no significant difference in the 4R/3R ratio between Pick's disease cases and controls, indicating that the predominance of tau3R protein in PiD reflects post-translational modifications of specific isoforms. This study indicates that post-translational events are likely to be the main factors controlling tau isoform composition in sporadic tauopathies and highlights the benefit of quantitative RT-PCR in the assessment of splicing abnormalities in tauopathies.

    Funded by: Parkinson's UK: G-4029; Wellcome Trust

    Brain research. Molecular brain research 2005;137;1-2;104-9

  • The effect of tau genotype on clinical features in FTDP-17.

    Baba Y, Tsuboi Y, Baker MC, Uitti RJ, Hutton ML, Dickson DW, Farrer M, Putzke JD, Woodruff BK, Ghetti B, Murrell JR, Boeve BF, Petersen RC, Verpillat P, Brice A, Delisle MB, Rascol O, Arima K, Dysken MW, Yasuda M, Kobayashi T, Sunohara N, Komure O, Kuno S, Sperfeld AD, Stoppe G, Kohlhase J, Pickering-Brown S, Neary D, Bugiani O and Wszolek ZK

    Department of Neurology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.

    The clinical phenotype of frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) varies. This variability is seen not only between kindreds with different mutations but also in families sharing the same mutation. Inheritance of tau haplotype (H1) and genotype (H1/H1) has been established as a risk factor for some neurodegenerative disorders with parkinsonism. We assessed the effect of tau polymorphism on the clinical features of FTDP-17 in 61 cases from 30 separately ascertained families with four different tau mutations, including P301L, +16, N279K, and P301S. There were no significant differences of age at symptomatic onset and disease duration between H1/H1 and H1/H2 genotypes. The comparison between tau genotype and type of initial clinical sign showed an association between the H1/H1 genotype and parkinsonian phenotype and between the H1/H2 genotype and frontotemporal dementia phenotype (OR=11.7; 95% confidence interval, 1.4-98.7; P=0.008). Our results suggest that tau genotype does not influence the disease course. However, it may predispose to a specific clinical sign in the early stage of FTDP-17.

    Parkinsonism & related disorders 2005;11;4;205-8

  • Tau is not normally degraded by the proteasome.

    Feuillette S, Blard O, Lecourtois M, Frébourg T, Campion D and Dumanchin C

    INSERM U614, IFRMP, Faculty of Medicine, Rouen, France.

    Tau-positive inclusions in neurons are consistent neuropathologic features of the most common causes of dementias such Alzheimer's disease and frontotemporal dementia. Ubiquitinated tau-positive inclusions have been reported in brains of Alzheimer's disease patients, but involvement of the ubiquitin-dependent proteasomal system in tau degradation remains controversial. Before considering the tau degradation in pathologic conditions, it is important to determine whether or not endogenous tau is normally degraded by the proteasome pathway. We therefore investigated this question using two complementary approaches in vitro and in vivo. Firstly, SH-SY5Y human neuroblastoma cells were treated with different proteasome inhibitors, MG132, lactacystin, and epoxomicin. Under these conditions, neither total nor phosphorylated endogenous tau protein levels were increased. Instead, an unexpected decrease of tau protein was observed. Secondly, we took advantage of a temperature-sensitive mutant allele of the 20S proteasome in Drosophila. Genetic inactivation of the proteasome also resulted in a decrease of tau levels in Drosophila. These results obtained in vitro and in vivo demonstrate that endogenous tau is not normally degraded by the proteasome.

    Journal of neuroscience research 2005;80;3;400-5

  • Fragmentation of the Golgi apparatus induced by the overexpression of wild-type and mutant human tau forms in neurons.

    Liazoghli D, Perreault S, Micheva KD, Desjardins M and Leclerc N

    Département de Pathologie et Biologie Cellulaire, Université de Montréal, 2900, Boulevard Edouard-Montpetit, Montréal, Québec, Canada, H3T 1J4.

    Tau is a microtubule-associated protein enriched in the axonal compartment. In several neurodegenerative diseases including Alzheimer's disease, hyperphosphorylated tau accumulates in the somatodendritic compartment, self-aggregates, and forms neurofibrillary tangles. A fragmentation of the neuronal Golgi apparatus (GA) was also observed in Alzheimer's disease. In the present study, we examined the effect of overexpressing human tau on the organization of the neuronal GA in rat hippocampal cultures and in JNPL3 mice expressing tau mutant P301L. GA fragmentation was noted in a significantly higher percentage of hippocampal neurons overexpressing wild-type human tau than in control neurons over-expressing green fluorescent protein (GFP) alone. Most importantly, in neurons overexpressing mutant forms of human tau (P301L, V337M, or R406W), the percentage of neurons with a fragmented GA was 10% higher than that of neurons overexpressing wild-type human tau. In JNPL3 mice, a significantly higher percentage of motor neurons presented a fragmented GA compared to control mice. Interestingly, fragmentation of the GA was more frequent in neurons containing an accumulation and aggregation of hyperphosphorylated tau in the cell body than in neurons without these features. In both primary hippocampal neurons and JNPL3 mice, the tau-induced GA fragmentation was not caused by apoptosis. The pre-sent results implicate tau in GA fragmentation and show that this event occurs before the formation of neurofibrillary tangles.

    The American journal of pathology 2005;166;5;1499-514

  • Novel G335V mutation in the tau gene associated with early onset familial frontotemporal dementia.

    Neumann M, Diekmann S, Bertsch U, Vanmassenhove B, Bogerts B and Kretzschmar HA

    Center for Neuropathology and Prion Research, Ludwig Maximilians University, Munich, Germany.

    Mutations in the tau gene cause familial frontotemporal dementia and parkinsonism linked to chromosome 17. Here we describe a novel missense mutation in exon 12 of the tau gene, G335V, in a German family with frontotemporal dementia of early age at onset, in the third decade of life. Functional analysis of recombinant tau protein with the G335V mutation showed a dramatically reduced ability to promote microtubule assembly and a more rapid and accelerated tau filament formation, suggesting that the primary effect of the mutation might be the provision of a pool of unbound tau making it available for aberrant tau aggregation.

    Neurogenetics 2005;6;2;91-5

  • Proteomic analysis of neurofibrillary tangles in Alzheimer disease identifies GAPDH as a detergent-insoluble paired helical filament tau binding protein.

    Wang Q, Woltjer RL, Cimino PJ, Pan C, Montine KS, Zhang J and Montine TJ

    Department of Pathology, Division of Neuropathology, University of Washington, Seattle, Washington 98105, USA.

    We performed proteomic analysis of neurofibrillary tangles (NFTs) obtained by laser capture microdissection from pyramidal neurons in hippocampal sector CA1 in patients with Alzheimer disease (AD) using liquid chromatography (LC)-mass spectrometry (MS)/MS. We discovered a total of 155 proteins in laser captured NFT's, 72 of which were identified by multiple unique peptides. Of these 72 proteins, 63 had previously unknown association with NFTs; one of these was glyceraldehyde-3-phosphate dehydrogenase (GAPDH). We validated by immunohistochemistry that GAPDH co-localized with the majority of NFTs as well as plaque-like structures in AD brain and was co-immunoprecipitated by antibodies to abnormal forms of tau in AD, but not tau from AD temporal cortex. Characterization of GAPDH showed that it, along with phosphorylated tau and Abeta peptides, was present in detergent-insoluble fractions from AD temporal cortex but not from age-matched controls. These data are the first proteomic investigation of NFTs. Moreover, our results validate this approach by demonstrating that GAPDH, a glycolytic and microtubule binding protein, not only co-localized to NFTs and immunoprecipitated with PHF-tau, but also is one of the few proteins known to undergo conversion to a detergent-insoluble form in AD.

    Funded by: NIA NIH HHS: AG05136, AG05144, AG22040, AG24011

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 2005;19;7;869-71

  • Nitration and oligomerization of tau induced by peroxynitrite inhibit its microtubule-binding activity.

    Zhang YJ, Xu YF, Chen XQ, Wang XC and Wang JZ

    Pathophysiology Department, Neuroscience Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

    Abnormally nitrated tau has been found recently in the neurofibrillary tangles of Alzheimer's disease (AD). However, whether and how nitration of tau is involved in AD pathology is not known. Herein, we found that in vitro incubation of peroxynitrite with recombinant tau resulted in nitration and oligomerization of tau in a dosage-dependent manner. Moreover, the nitrated tau showed a significantly decreased binding activity to taxol-stabilized microtubulesin in vitro. Further study demonstrated that peroxynitrite also induced tau nitration in neuroblastoma N2a cell line, and the nitrated tau was accumulated in the cells. We conclude that abnormal nitration of tau contributes to the impaired biological activity of tau in binding to the microtubules and the aggregation of tau, implying a novel mechanism responsible for the neurodegeneration seen in AD brain.

    FEBS letters 2005;579;11;2421-7

  • Triggers of full-length tau aggregation: a role for partially folded intermediates.

    Chirita CN, Congdon EE, Yin H and Kuret J

    Biophysics Program, The Ohio State University, Columbus, Ohio 43210, USA.

    Alzheimer's disease is characterized in part by the accumulation of full-length tau proteins into intracellular filamentous inclusions. To clarify the events that trigger lesion formation, the aggregation of recombinant full-length four-repeat tau (htau40) was examined in vitro under near-physiological conditions using transmission electron microscopy and spectroscopy methods. In the absence of exogenous inducers, tau protein behaved as an assembly-incompetent monomer with little tertiary structure. The addition of anionic inducers led to fibrillization with nucleation-dependent kinetics. On the basis of circular dichroism spectroscopy and reactivity with thioflavin S and 8-anilino-1-naphthalenesulfonic acid fluorescent probes, the inducer stabilized a monomeric species with the folding characteristics of a premolten globule state. Planar aromatic dyes capable of binding the intermediate state with high affinity were also capable of triggering fibrillization in the absence of other inducers. Dye-mediated aggregation was characterized by concentration-dependent decreases in lag time, indicating increased nucleation rates, and submicromolar critical concentrations, indicating a final equilibrium that favored the filamentous state. The data suggest that the rate-limiting barrier for filament formation from full-length tau is conformational and that the aggregation reaction is triggered by environmental conditions that stabilize assembly-competent conformations.

    Funded by: NIA NIH HHS: AG14452

    Biochemistry 2005;44;15;5862-72

  • Three- and four-repeat tau regulate the dynamic instability of two distinct microtubule subpopulations in qualitatively different manners. Implications for neurodegeneration.

    Levy SF, Leboeuf AC, Massie MR, Jordan MA, Wilson L and Feinstein SC

    Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA.

    The microtubule-associated protein tau is implicated in the pathogenesis of many neurodegenerative diseases, including fronto-temporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), in which both RNA splicing and amino acid substitution mutations in tau cause dominantly inherited early onset dementia. RNA-splicing FTDP-17 mutations alter the wild-type approximately 50:50 3-repeat (3R) to 4-repeat (4R) tau isoform ratio, usually resulting in an excess of 4R tau. To examine further how splicing mutations might cause dysfunction by misregulation of microtubule dynamics, we used video microscopy to determine the in vitro behavior of individual microtubules stabilized by varying amounts of human 4R and 3R tau. At low tau:tubulin ratios (1:55 and 1:45), all 3R isoforms reduced microtubule growth rates relative to the no-tau control, whereas all 4R isoforms increased them; however, at a high tau:tubulin ratio (1:20), both 4R and 3R tau increased the growth rates. Further analysis revealed two distinct subpopulations of growing microtubules in the absence of tau. Increasing concentrations of both 4R and 3R tau resulted in an increase in the size of the faster growing subpopulation of microtubules; however, 4R tau caused a redistribution to the faster growing subpopulation at lower tau:tubulin ratios than 3R tau. This modulation of discrete growth rate subpopulations by tau suggests that tau causes a conformational shift in the microtubule resulting in altered dynamics. Quantitative and qualitative differences observed between 4R and 3R tau are consistent with a "microtubule misregulation" model in which abnormal tau isoform expression results in the inability to properly regulate microtubule dynamics, leading to neuronal death and dementia.

    Funded by: NCI NIH HHS: CA57291; NINDS NIH HHS: NS13560, NS35010

    The Journal of biological chemistry 2005;280;14;13520-8

  • Tau phosphorylation in Alzheimer's disease: pathogen or protector?

    Lee HG, Perry G, Moreira PI, Garrett MR, Liu Q, Zhu X, Takeda A, Nunomura A and Smith MA

    Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106 USA.

    During the past decade, hypotheses concerning the pathogenesis of most neurodegenerative diseases have been dominated by the notion that the aggregation of specific proteins and subsequent formation of cytoplasmic and extracellular lesions represent a harbinger of neuronal dysfunction and death. As such, in Alzheimer's disease, phosphorylated tau protein, the major component of neurofibrillary tangles, is considered a central mediator of disease pathogenesis. We challenge this classic notion by proposing that tau phosphorylation represents a compensatory response mounted by neurons against oxidative stress and serves a protective function. This novel concept, which can also be applied to protein aggregates in other neurodegenerative diseases, opens a new window of knowledge with broad implications for both the understanding of mechanisms underlying disease pathophysiology and the design of new therapeutic strategies.

    Trends in molecular medicine 2005;11;4;164-9

  • Alzheimer-specific epitopes of tau represent lipid peroxidation-induced conformations.

    Liu Q, Smith MA, Avilá J, DeBernardis J, Kansal M, Takeda A, Zhu X, Nunomura A, Honda K, Moreira PI, Oliveira CR, Santos MS, Shimohama S, Aliev G, de la Torre J, Ghanbari HA, Siedlak SL, Harris PL, Sayre LM and Perry G

    Institute of Pathology, Case Western Reserve University, 2085 Adelbert Road, Cleveland, OH 44106, USA.

    Several recent studies support a link between tau protein phosphorylation and adduction of tau by reactive carbonyls. Indeed, the phosphorylation-dependent adduction of tau by carbonyl products resulting from lipid peroxidation creates the neurofibrillary tangle-related antigen, Alz50. To determine whether epitopes of carbonyl-modified tau are major conformational changes associated with neurofibrillary tangle formation, we examined seven distinct antibodies raised against neurofibrillary tangles that recognize unique epitopes of tau in Alzheimer disease. Consistently, all seven antibodies recognize tau more strongly (4- to 34-fold) after treatment of normal tau with the reactive carbonyl, 4-hydroxy-2-nonenal (HNE), but only when tau is in the phosphorylated state. These findings not only support the idea that oxidative stress is involved in neurofibrillary tangle formation occurring in brains of Alzheimer disease patients, but also show, for the first time, that HNE modifications of tau promote and contribute to the generation of the major conformational properties defining neurofibrillary tangles.

    Funded by: NIA NIH HHS: AG14249; NINDS NIH HHS: NS38648

    Free radical biology & medicine 2005;38;6;746-54

  • Interaction of alpha-synuclein and tau genotypes in Parkinson's disease.

    Mamah CE, Lesnick TG, Lincoln SJ, Strain KJ, de Andrade M, Bower JH, Ahlskog JE, Rocca WA, Farrer MJ and Maraganore DM

    Department of Neurology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.

    To determine whether the microtubule-associated protein tau (MAPT) and alpha-synuclein (SNCA) genes interact to confer Parkinson's disease (PD) susceptibility, we conducted a study of 557 case-control pairs. There was an increased risk of PD for persons with either SNCA 261/261 or MAPT H1/H1 genotypes as compared with persons with neither (odds ratio, 1.96; 95% confidence interval, 1.34-2.86; p = 0.0003). However, the combined effect of the two genotypes was the same as for either of the genotypes alone (separate and equal). These findings are consistent with in vitro experiments that revealed tau-mediated fibrillization of alpha-synuclein protein at low concentrations (dose threshold effect).

    Funded by: NIEHS NIH HHS: R01 ES 10751; NINDS NIH HHS: P01 NS 40256, R01 NS 33978

    Annals of neurology 2005;57;3;439-43

  • Phosphoproteomic analysis of synaptosomes from human cerebral cortex.

    DeGiorgis JA, Jaffe H, Moreira JE, Carlotti CG, Leite JP, Pant HC and Dosemeci A

    Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.

    Protein phosphorylation is a crucial post-translational modification mechanism in the regulation of synaptic organization and function. Here, we analyzed synaptosome fractions from human cerebral cortex obtained during therapeutic surgery. To minimize changes in the phosphorylation state of proteins, the tissue was homogenized within two minutes of excision. Synaptosomal proteins were digested with trypsin and phosphopeptides were isolated by immobilized metal affinity chromatography and analyzed by liquid chromatography and tandem mass spectrometry. The method allowed the detection of residues on synaptic proteins that were presumably phosphorylated in the intact cell, including synapsin 1, syntaxin 1, and SNIP, PSD-93, NCAM, GABA-B receptor, chaperone molecules, and protein kinases. Some of the residues identified are the same or homologous to sites that had been previously described to be phosphorylated in mammals whereas others appear to be novel sites which, to our knowledge, have not been reported previously. The study shows that new phosphoproteomic strategies can be used to analyze subcellular fractions from small amounts of tissue for the identification of phosphorylated residues for research and potentially for diagnostic purposes.

    Journal of proteome research 2005;4;2;306-15

  • Site-specific pseudophosphorylation modulates the rate of tau filament dissociation.

    Necula M and Kuret J

    Biophysics Program, The Ohio State University College of Medicine and Public Health, Columbus, OH 43210, USA.

    Hyperphosphorylation of tau is of fundamental importance for neurofibrillary lesion development in Alzheimer's disease, but the mechanisms through which it acts are not clear. Experiments with pseudophosphorylation mutants of full-length tau protein indicate that incorporation of negative charge into specific sites can modulate the aggregation reaction, and that this occurs by altering the critical concentration of assembly. Here, the kinetic origin of this effect was determined using quantitative electron microscopy methods and pseudophosphorylation mutant T212E in a full-length four-repeat tau background. On the basis of disaggregation rates, decreases in critical concentration resulted primarily from decreases in the dissociation rate constant. The results suggest a mechanism through which site-specific posttranslational modifications can modulate filament accumulation at low free intracellular tau concentrations.

    Funded by: NIA NIH HHS: AG14452

    FEBS letters 2005;579;6;1453-7

  • Structural evaluation of conformational transition state responsible for self-assembly of tau microtubule-binding domain.

    Minoura K, Mizushima F, Tokimasa M, Hiraoka S, Tomoo K, Sumida M, Taniguchi T and Ishida T

    Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan. minoura@gly.oups.ac.jp

    In the brains of Alzheimer's disease patients, the tau protein abnormally aggregates to form an insoluble paired helical filament (PHF). Since the third repeat structure (R3) of the tau microtubule-binding domain plays an essential role in PHF formation and self-aggregates most significantly in an aqueous solution of 20-40% trifluoroethanol (TFE), its possible conformation was estimated from the combination of (i) the TFE-dependent deviations of NH and CalphaH proton chemical shifts from those of the random structure in water and (ii) the TFE-dependent NOE effect connectivity diagrams between the neighboring protons. Consequently, it was indicated that the extended structure of the N-terminal VQIVYK moiety and the alpha-helical-like structure of the LSKVTSKC region provide a structural scaffold for initiating the self-assembled filament formation of the R3 structure. To the best of our knowledge, this is the first study that demonstrated the initial structural moiety and its structural feature necessary for starting the tau PHF formation.

    Biochemical and biophysical research communications 2005;327;4;1100-4

  • Proteolysis of non-phosphorylated and phosphorylated tau by thrombin.

    Arai T, Guo JP and McGeer PL

    Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.

    The microtubule-associated protein tau aggregates intracellularly by unknown mechanisms in Alzheimer's disease and other tauopathies. A contributing factor may be a failure to break down free cytosolic tau, thus creating a surplus for aggregation, although the proteases that degrade tau in brain remain unknown. To address this issue, we prepared cytosolic fractions from five normal human brains and from perfused rat brains and incubated them with or without protease inhibitors. D-Phenylalanyl-L-prolylarginyl chloromethyl ketone, a thrombin-specific inhibitor, prevented tau breakdown in these fractions, suggesting that thrombin is a brain protease that processes tau. We next exposed human recombinant tau to purified human thrombin and analyzed the fragments by N-terminal sequencing. We found that thrombin proteolyzed tau at multiple arginine and lysine sites. These include Arg(155)-Gly(156), Arg(209)-Ser(210), Arg(230)-Thr(231), Lys(257)-Ser(258), and Lys(340)-Ser(341) (numbering according to the longest human tau isoform). Temporally, the initial cleavage occurred at the Arg(155)-Gly(156) bond. Proteolysis of the resultant C-terminal tau fragment then proceeded bidirectionally. When tau was phosphorylated by glycogen synthase kinase-3beta, most of these proteolytic processes were inhibited, except for the first cleavage at the Arg(155)-Gly(156) bond. Furthermore, paired helical filament tau prepared from Alzheimer's disease brain was more resistant to thrombin proteolysis than following dephosphorylation by alkaline phosphatase. The results suggest a possible role for thrombin in proteolysis of tau under physiological and/or pathological conditions in human brains. They are consistent with the hypothesis that phosphorylation of tau inhibits proteolysis by thrombin or other endogenous proteases, leading to aggregation of tau into insoluble fibrils.

    The Journal of biological chemistry 2005;280;7;5145-53

  • Apoptotic effect of caspase-3 cleaved tau in hippocampal neurons and its potentiation by tau FTDP-mutation N279K.

    Fasulo L, Ugolini G and Cattaneo A

    Laboratory Molecular Neurobiology (LMN), International School for Advanced Studies (S.I.S.S.A.), Area Science Park, Padriciano 99, 34013 Trieste, Italy.

    Pathological changes in the microtubule associated protein tau are a major hallmark of many human dementias collectively defined as tauopathies. In familiar frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), several mutations in the tau gene have been identified showing that primary malfunction of tau can lead to neurodegeneration. In addition to mutation at genetic level, a number of post-translational modifications of tau occur in tauopathies, including abnormal phosphorylation and aberrant proteolysis described in Alzheimer's Disease (AD). The presence of cleaved tau in AD neurons is associated with expression of markers for neuronal death. According to our previous work, tau is a substrate for the apoptotic protease caspase-3 that turns tau itself into an effector of apoptosis (tau cleaved at D-421), generating a positive-feedback loop that is self-propagating. Cleavage of tau by caspase-3 was recently confirmed to occur in AD brain as an early event. Here we show the apoptotic properties of tau fragment tau151-421 in primary cultures of rat hippocampal neurons; such cellular model is of special interest considering the selective vulnerability of hippocampal neurones in AD. The apoptotic capacity of tau151-421 is markedly enhanced by both treatment with amyloid peptide Abeta25-35, and the FTDP-17 tau mutation N279K.

    Funded by: Telethon: E.1044

    Journal of Alzheimer's disease : JAD 2005;7;1;3-13

  • Dephosphorylation of tau by protein phosphatase 5: impairment in Alzheimer's disease.

    Liu F, Iqbal K, Grundke-Iqbal I, Rossie S and Gong CX

    New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA. feiliu63@hotmail.com

    Protein phosphatase (PP) 5 is highly expressed in the mammalian brain, but few physiological substrates have yet been identified. Here, we investigated the kinetics of dephosphoryation of phospho-tau by PP5 and found that PP5 had a K(m) of 8-13 microm toward tau, which is similar to that of PP2A, the major known tau phosphatase. This K(m) value is within the range of intraneuronal tau concentration in human brain, suggesting that tau could be a physiological substrate of both PP5 and PP2A. PP5 dephosphorylated tau at all 12 Alzheimer's disease (AD)-associated abnormal phosphorylation sites studied, with different efficiency toward each site. Thr(205), Thr(212), and Ser(409) of tau were the most favorable sites; Ser(199), Ser(202), Ser(214), Ser(396), and Ser(404) were less favorable sites; and Ser(262) was the poorest site for PP5. Overexpression of PP5 in PC12 cells resulted in dephosphorylation of tau at multiple phosphorylation sites. The activity but not the protein level of PP5 was found to be decreased by approximately 20% in AD neocortex. These results suggest that tau is probably a physiological substrate of PP5 and that the abnormal hyperphosphorylation of tau in AD might result in part from the decreased PP5 activity in the diseased brains.

    Funded by: NIA NIH HHS: AG16760, AG19157; NINDS NIH HHS: NS31221

    The Journal of biological chemistry 2005;280;3;1790-6

  • Changes in conformation of human neuronal tau during denaturation in formaldehyde solution.

    Nie CL, Zhang W, Zhang D and He RQ

    Lab of Visual Information Processing, Institute of Biophysics, Chinese Academy of Sciences, Beijing.

    Human neuronal tau was incubated in formaldehyde solution at low concentrations and the intensity of light scattering of tau-40 solution at 480 nm increased markedly. Then potassium iodide was used to quench the intrinsic fluorescence of tau. The fluorescent quenching constants decreased as formaldehyde concentrations increased. 8-anilino-1-naphthalenesulfonic acid (ANS) binding assay showed that a putative hydrophobic core formed in tau polymers during incubation with formaldehyde. Native tau was hydrolyzed by immobilized earthworm fibrinolytic enzyme-II (EFE-II), producing a digested fragment (36-37 kDa). However, formaldehyde-treated tau could not be digested under the same conditions, suggesting that aggregated protein was relatively rigidly deposited.

    Protein and peptide letters 2005;12;1;75-8

  • The tau gene haplotype h1 confers a susceptibility to Parkinson's disease.

    Zhang J, Song Y, Chen H and Fan D

    Department of Neurology, the Third Hospital of Beijing University, Beijing, China. who626@163.com

    Background: Polymorphisms in the tau gene may be associated with increased risk for idiopathic Parkinson's disease (PD); however, most of previous association studies have been underpowered to detect a potentially modest contribution of the tau variants to PD risk.

    Objective: To clarify the relationship between genetic variation in tau gene and PD risk, we conducted a meta-analysis of all published association studies. We identified 14 independent case-control studies including 2,093 PD cases and 2,258 controls. After excluding two studies contributing to most of between-study heterogeneity, the pooled odds ratios (OR) and 95% confidence intervals (CI) of PD were 1.42 (95% CI, 1.23-1.65) for those with H1/H1 genotype compared with all others and 1.52 (95% CI, 1.12-2.04) for all individuals carrying H1 haplotype versus all others. Based on the data available, the results were not significantly different according to sex, family history of PD, age at onset and dementia status.

    Conclusions: Our results support the notion that tau gene H1 haplotype may be an important risk factor of PD.

    European neurology 2005;53;1;15-21

  • TAU haplotype and the Saitohin Q7R gene polymorphism do not influence CSF Tau in Alzheimer's disease and are not associated with frontotemporal dementia or Parkinson's disease.

    Johansson A, Zetterberg H, Håkansson A, Nissbrandt H and Blennow K

    Department of Clinical Neuroscience, Unit of Neurochemistry, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. annica.johansson@clinchem.gu.se

    Background: Recent studies have described Saitohin(STH), a gene located in the human TAU gene. The corresponding protein shows a similar tissue expression to tau, which is involved in many neurodegenerative disorders including Alzheimer's disease (AD), frontotemporal dementia (FTD) and Parkinson's disease (PD). A single nucleotide polymorphism in the STH gene has been suggested to be involved in sporadic AD and is in complete linkage disequilibrium with the TAU haplotype H1.

    Objective: A case-control study was performed to further explore the possible involvement of the STH Q7R polymorphism and the extended TAU haplotype in AD, FTD or PD.

    Methods: Patients with AD (n = 398), FTD (n = 96) and PD (n = 105), and controls (n = 186) were genotyped for the STH polymorphism and/or the TAU haplotype. Genotype data were related to levels of total-tau, phospho-tau and Abeta(1-42) in cerebral spinal fluid (CSF) in more than 300 AD patients and to an amount of senile plaques and neurofibrillary tangles in the frontal cortex and hippocampus in patients with autopsy-confirmed AD.

    Results: The STH Q7R polymorphism and the TAU haplotype were in complete linkage disequilibrium in all patients (AD and FTD) and controls investigated for both genes. There were no significant differences in genotype or allele distributions in AD, FTD or PD cases compared to controls. Neither TAU haplotype nor STH influenced CSF levels of total-tau, phospho-tau and Abeta(1-42) significantly. In AD patients with neuropathological scores of plaque and tangles, no associations with TAU haplotype and STH were found.

    Conclusion: We found no evidence that could support a major pathogenic role of STH and TAU haplotype in AD, FTD or PD.

    Neuro-degenerative diseases 2005;2;1;28-35

  • Galpha12 directly interacts with PP2A: evidence FOR Galpha12-stimulated PP2A phosphatase activity and dephosphorylation of microtubule-associated protein, tau.

    Zhu D, Kosik KS, Meigs TE, Yanamadala V and Denker BM

    Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.

    The Galpha(12/13) family of heterotrimeric G proteins modulate multiple cellular processes including regulation of the actin cytoskeleton. Galpha(12/13) interact with several cytoskeletal/scaffolding proteins, and in a yeast two-hybrid screen with Galpha(12), we detected an interaction with the scaffolding subunit (Aalpha) of the Ser/Thr phosphatase, protein phosphatase 2A (PP2A). PP2A dephosphorylates multiple substrates including tau, a microtubule-associated protein that is hyperphosphorylated in neurofibrillary tangles. The interaction of Aalpha and Galpha(12) was confirmed by coimmunoprecipitation studies in transfected COS cells and by glutathione S-transferase (GST)-Galpha(12) pull-downs from cell lysates of primary neurons. The interaction was specific for Aalpha and Galpha(12) and was independent of Galpha(12) conformation. Endogenous Aalpha and Galpha(12) colocalized by immunofluorescent microscopy in Caco-2 cells and in neurons. In vitro reconstitution of GST-Galpha(12) or recombinant Galpha(12) with PP2A core enzyme resulted in approximately 300% stimulation of PP2A activity that was not detected with other Galpha subunits and was similar with GTPgammaS- and GDP-liganded Galpha(12). When tau and active kinase (Cdk5 and p25) were cotransfected in to COS cells, there was robust tau phosphorylation. Co-expression of wild type or QLalpha(12) with tau and the active kinase resulted in 60 +/- 15% reductions in tau phosphorylation. In primary cortical neurons stimulated with lysophosphatitic acid, a 50% decrease in tau phosphorylation was observed. The Galpha(12) effect on tau phosphorylation was inhibited by the PP2A inhibitor, okadaic acid (50 nm), in COS cells and neurons. Taken together, these findings reveal novel, direct regulation of PP2A activity by Galpha(12) and potential in vivo modulation of PP2A target proteins including tau.

    Funded by: NCI NIH HHS: CA 100869; NIGMS NIH HHS: GM 55223

    The Journal of biological chemistry 2004;279;53;54983-6

  • Calcium dyshomeostasis in beta-amyloid and tau-bearing skeletal myotubes.

    Christensen RA, Shtifman A, Allen PD, Lopez JR and Querfurth HW

    Department of Neurology, Caritas St. Elizabeth's Medical Center, Tufts University School of Medicine, 736 Cambridge St., Boston, MA 02135, USA.

    The relative scarcity of inclusion-affected muscle cells or markers of cell death in inclusion body myositis (IBM) is in distinction to the specific and early intracellular deposition of several Alzheimer's Disease (AD)-related proteins. The current study examined the possible correlation between myotube beta-amyloid and/or Tau accumulations and a widespread mishandling of intracellular muscle calcium concentration that could potentially account for the unrelenting weakness in affected patients. Cultured myogenic cells (C(2)C(12)) expressed beta-amyloid-42 (Abeta(42)) and fetal Tau peptides, as human transgenes encoded by herpes simplex virus, either individually or concurrently. Co-expression of Abeta(42) in C(2)C(12) myotubes resulted in hyperphosphorylation of Tau protein that was not observed when Tau was expressed alone. Resting calcium concentration and agonist-induced RyR-mediated Ca(2+) release were examined using calcium-specific microelectrodes and Fluo-4 epifluorescence, respectively. Co-expression of Abeta(42) and Tau cooperatively elevated basal levels of myoplasmic-free calcium, an effect that was accompanied by depolarization of the plasma membrane. Sarcoplasmic reticulum (SR) calcium release, induced by KCl depolarization, was not affected by Abeta(42) or Tau. In contrast, expression of Abeta(42), Tau, or Abeta(42) together with Tau resulted in enhanced sensitivity of ryanodine receptors to activation by caffeine. Notably, expression of beta-amyloid, alone, was sufficient to result in an increased sensitivity to direct activation by caffeine. Current results indicate that amyloid proteins cooperate to raise resting calcium levels and that these effects are associated with a passive SR Ca(2+) leak and Tau hyperphosphorylation in skeletal muscle.

    Funded by: NIAMS NIH HHS: 1F32AR049160-1, 5R01AR046513; NINDS NIH HHS: R01 NS041373

    The Journal of biological chemistry 2004;279;51;53524-32

  • Lewy bodies in the amygdala: increase of alpha-synuclein aggregates in neurodegenerative diseases with tau-based inclusions.

    Popescu A, Lippa CF, Lee VM and Trojanowski JQ

    Department of Neurology, Drexel University College of Medicine, 3300 Henry Avenue, Philadelphia, PA 19129, USA.

    Background: Increased attention has been given to alpha-synuclein aggregation in nonsynucleinopathies because alpha-synuclein-containing Lewy bodies (LBs) influence symptoms. However, the spectrum of disorders in which secondary inclusions are likely to occur has not been defined. Amygdala neurons commonly develop large numbers of secondary LBs, making it a practical region for studying this phenomenon.

    Objective: To characterize the spectrum of diseases associated with LB formation in the amygdala of neurodegenerative disease and control cases.

    Design: An autopsy series of 101 neurodegenerative disease and 34 aged control cases. Using immunohistochemistry studies, we examined the amygdala for alpha-synuclein aggregates.

    Results: Lewy bodies were often abundant in classic Pick disease, argyrophilic grain disease, Alzheimer disease, and dementia with LBs but not in cases with amygdala degeneration lacking tau-based inclusions, control cases, preclinical disease carriers, or degenerative diseases lacking pathologic involvement of the amygdala. The exposed alpha-synuclein epitopes were similar in all cases containing LBs.

    Conclusions: Abnormal alpha-synuclein aggregation in the amygdala is disease selective, but not restricted to disorders of alpha-synuclein and beta-amyloid. Our data are compatible with the notion that tau aggregates predispose neurons to develop secondary LBs.

    Archives of neurology 2004;61;12;1915-9

  • [Genetic tau-variants in patients with frontotemporal dementia].

    Ibach B, Wittmann M, Pfannenschmid F, Poljansky S, Haen E and Hajak G

    Klinik und Poliklinik für Psychiatrie und Psychotherapie der Universität Regensburg am Bezirksklinikum. bernd.ibach@medbo.de

    Objective: [corrected] To evaluate tau-associated genetic polymorphisms in patients with sporadic frontotemporal dementia (FTD) and healthy control subjects.

    Method: Tau-gene sequence of 30 patients with FTD and 30 healthy controls was analysed by polymerase-chain-reaction (PCR). Subsequent sequencing was performed to identify exonic and intronic differences between both groups.

    Results: The following polypmorphisms, which are localized closely to each exon-intron-border, have been identified: In 37 % (n = 11) of the control subjects three different intronic polymorphisms occur simultaneously (Intron 2, 263, C --> Y; Intron 3, 590, A --> R; Intron 11, 150, G --> A). In the FTD group, this coexistance has been observed only in 17 % (n = 5).

    Conclusions: In how far there exists a significant correlation between the newly identified triple polymorphism in the Tau gene and an alternated risk for FTD must be evaluated in a lager population. The proximity of these polymorphisms to the exon-intron border would facilitate functional influences on gene expression patterns. These preliminary results described, above potentially point to further pathogenetic factors in the genesis of FTD.

    Psychiatrische Praxis 2004;31 Suppl 1;S55-7

  • Induction of inflammatory mediators and microglial activation in mice transgenic for mutant human P301S tau protein.

    Bellucci A, Westwood AJ, Ingram E, Casamenti F, Goedert M and Spillantini MG

    Brain Repair Centre, University of Cambridge, Robinson Way, Cambridge CB2 2PY, UK.

    Mice transgenic for human P301S tau protein exhibit many characteristics of the human tauopathies, including the formation of abundant filaments made of hyperphosphorylated tau protein and neurodegeneration leading to nerve cell loss. At 5 months of age, the pathological changes are most marked in brainstem and spinal cord. Here we show that these changes are accompanied by marked neuroinflammation. Many tau-positive nerve cells in brainstem and spinal cord were strongly immunoreactive for interleukin-1beta and cyclooxygenase-2, indicating induction and overproduction of proinflammatory cytokines and enzymes. In parallel, numerous activated microglial cells were present throughout brain and spinal cord of transgenic mice, where they concentrated around tau-positive nerve cells. These findings suggest that inflammation may play a significant role in the events leading to neurodegeneration in the tauopathies and that anti-inflammatory compounds may have therapeutic potential.

    The American journal of pathology 2004;165;5;1643-52

  • Phosphoproteomic analysis of the developing mouse brain.

    Ballif BA, Villén J, Beausoleil SA, Schwartz D and Gygi SP

    Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.

    Proper development of the mammalian brain requires the precise integration of numerous temporally and spatially regulated stimuli. Many of these signals transduce their cues via the reversible phosphorylation of downstream effector molecules. Neuronal stimuli acting in concert have the potential of generating enormous arrays of regulatory phosphoproteins. Toward the global profiling of phosphoproteins in the developing brain, we report here the use of a mass spectrometry-based methodology permitting the first proteomic-scale phosphorylation site analysis of primary animal tissue, identifying over 500 protein phosphorylation sites in the developing mouse brain.

    Funded by: NHGRI NIH HHS: HG00041

    Molecular & cellular proteomics : MCP 2004;3;11;1093-101

  • The tau H2 haplotype is almost exclusively Caucasian in origin.

    Evans W, Fung HC, Steele J, Eerola J, Tienari P, Pittman A, Silva Rd, Myers A, Vrieze FW, Singleton A and Hardy J

    Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA.

    We have assessed the distribution of the tau H1/H2 haplotype in the publicly available reference series of samples with representatives of most racial groups. This analysis shows that the H2 haplotype is probably exclusively Caucasian in origin and its marginal occurrence in other racial groups is likely to reflect admixture. We discuss this observation in terms of the origin of the H2 haplotype and the epidemiology of the tauopathies.

    Neuroscience letters 2004;369;3;183-5

  • Clinical, genetic, and neuropathologic characteristics of posterior cortical atrophy.

    Tang-Wai DF, Graff-Radford NR, Boeve BF, Dickson DW, Parisi JE, Crook R, Caselli RJ, Knopman DS and Petersen RC

    Department of Neurology, Mayo Alzheimer's Disease Research Center, Rochester, MN, USA. david.tang-wai@uhn.on.ca

    Objective: To examine the clinical, genetic, and neuropathologic features of posterior cortical atrophy (PCA).

    Using a broad definition of PCA as a syndrome with the insidious onset of visual dysfunction in the absence of primary ophthalmologic causes, the authors identified and then reviewed the presenting signs and symptoms, ApoE genotypes, tau haplotypes, and neuropathologic findings when available of PCA cases from two dementia research centers collected over the past 14 years.

    Results: The authors identified 40 PCA cases. Their mean age at symptom onset was 60.5 +/- 8.9 years. There were twice as many women as men in the series. The principal types of visual impairment were simultanagnosia (82%) and visual field defect (47.5%). Acalculia, alexia, and anomia were also common. Insight was preserved in almost all (95%) early in the disorder. Neither apoE epsilon4 nor tau haplotype frequencies were different from typical Alzheimer disease (AD). Nine patients had died and underwent postmortem examination. Seven autopsied cases had AD pathology but when compared to typical AD, the neurofibrillary tangle (NFT) densities were significantly higher in Brodmann areas 17 and 18 (p < 0.05) and significantly lower in the hippocampus (p < 0.05). Two cases had corticobasal degeneration with maximal involvement of tau positive glial pathology in the posterior parietal lobe and Brodmann areas 17 and 18.

    Conclusions: PCA is a distinctive dementia syndrome in which the most pronounced pathologic involvement is in the occipitoparietal regions independent of the specific underlying pathology. AD was the most common pathologic cause, but its regional distribution differed from typical AD.

    Funded by: NIA NIH HHS: AG 07216, AG 16574

    Neurology 2004;63;7;1168-74

  • The role of tau (MAPT) in frontotemporal dementia and related tauopathies.

    Rademakers R, Cruts M and van Broeckhoven C

    Department of Molecular Genetics, Neurogenetics Group, Flanders Interuniversity Institute for Biotechnology, University of Antwerp, Antwerpen, Belgium.

    Tau is a multifunctional protein that was originally identified as a microtubule-associated protein. In patients diagnosed with frontotemporal dementia and parkinsonism linked to chromosome 17, mutations in the gene encoding tau (MAPT) have been identified that disrupt the normal binding of tau to tubulin resulting in pathological deposits of hyperphosphorylated tau. Abnormal filamentous tau deposits have been reported as a pathological characteristic in several other neurodegenerative diseases, including frontotemporal dementia, Pick Disease, Alzheimer disease, argyrophilic grain disease, progressive supranuclear palsy, and corticobasal degeneration. In the last five years, extensive research has identified 34 different pathogenic MAPT mutations in 101 families worldwide. In vitro, cell-free and transfected cell studies have provided valuable information on tau dysfunction and transgenic mice carrying human MAPT mutations are being generated to study the influence of MAPT mutations in vivo. This mutation update describes the considerable differences in clinical and pathological presentation of patients with MAPT mutations and summarizes the effect of the different mutations on tau functioning. In addition, the role of tau as a genetic susceptibility factor is discussed, together with the genetic evidence for additional causal genes for tau-positive as well as tau-negative dementia.

    Human mutation 2004;24;4;277-95

  • The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

    Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Morrin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J and MGC Project Team

    The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline.

    Funded by: PHS HHS: N01-C0-12400

    Genome research 2004;14;10B;2121-7

  • Chaperone-like manner of human neuronal tau towards lactate dehydrogenase.

    Tian R, Nie CL and He RQ

    Laboratory of Visual Information Processing, Center for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, China.

    In our experiments, inactivation of lactate dehydrogenase (LDH, EC1.1.1.27) in the presence of human microtubule-associated tau is observably suppressed during thermal and guanidine hydrochloride (GdnHCl) denaturation. Kinetic studies show tau can prevent LDH from self-aggregation monitored by light scattering during thermal denaturation. On the other hand, neuronal tau promotes reactivation of LDH and suppresses self-aggregation of non-native LDH when GdnHCl solution is diluted. Furthermore, the reactivation yield of LDH decreases significantly with delayed addition of tau. All experiments were completed in the reducing buffer with 1 mM DTT to avoid between tau and LDH forming the covalent bonds during unfolding and refolding. Thus, Tau prevents proteins from misfolding and aggregating into insoluble, nonfunctional inclusions and assists them to refold to reach the stable native state by binding to the exposed hydrophobic patches on proteins instead of by forming or breaking covalent bonds. Additionally, tau remarkably enhances reactivation of GDH (glutamic dehydrogenase, EC, another carbohydrate metabolic enzyme, also showing a chaperone-like manner. It suggests that neuronal tau non-specifically functions a chaperone-like protein towards the enzymes of carbohydrate metabolism.

    Neurochemical research 2004;29;10;1863-72

  • Linkage disequilibrium and association of MAPT H1 in Parkinson disease.

    Skipper L, Wilkes K, Toft M, Baker M, Lincoln S, Hulihan M, Ross OA, Hutton M, Aasly J and Farrer M

    Laboratories of Neurogenetics, Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.

    The MAPT H1 haplotype has been associated with four-repeat (4R) tauopathies, including progressive supranuclear palsy, corticobasal degeneration, and argyrophilic grain disease. More controversial is that the same haplotype has been associated with Parkinson disease (PD). Using H1-specific single-nucleotide polymorphisms, we demonstrate that MAPT H1 is a misnomer and consists of a family of recombining H1 alleles. Population genetics, linkage disequilibrium, and association analyses have shown that specific MAPT H1 subhaplotypes are preferentially associated with Parkinson disease. Using a sliding scale of MAPT H1-specific haplotypes--in age/sex-matched PD cases and controls from central Norway--we have refined the disease association to within an approximately 90-kb interval of the 5' end of the MAPT locus.

    American journal of human genetics 2004;75;4;669-77

  • Early N-terminal changes and caspase-6 cleavage of tau in Alzheimer's disease.

    Horowitz PM, Patterson KR, Guillozet-Bongaarts AL, Reynolds MR, Carroll CA, Weintraub ST, Bennett DA, Cryns VL, Berry RW and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA. p-horowitz@md.northwestern.edu

    Alzheimer's disease (AD) is a progressive amnestic dementia that involves post-translational hyperphosphorylation, enzymatic cleavage, and conformational alterations of the microtubule-associated protein tau. The truncation state of tau influences many of its pathologic characteristics, including its ability to assume AD-related conformations and to assemble into filaments. Cleavage also appears to be an important marker in AD progression. Although C-terminal truncation of tau at D421 has recently been attributed to the apoptotic enzyme caspase-3, N-terminal processing of the protein remains mostly uncharacterized. Here, we report immunohistochemical staining in a cohort of 35 cases ranging from noncognitively impaired to early AD with a panel of three N-terminal anti-tau antibodies: Tau-12, 5A6, and 9G3-pY18. Of these three, the phosphorylation-independent epitope of 5A6 was the earliest to emerge in the pathological lesions of tau, followed by the appearance of the Tau-12 epitope. The unmasking of the Tau-12 epitope in more mature 5A6-positive tangles was not correlated with tau phosphorylation at tyrosine 18 (9G3-pY18). Still, later in the course of tangle evolution, the extreme N terminus of tau was lost, correlating temporally with the appearance of a C-terminal caspase-truncated epitope lacking residues 422-441. In addition, caspase-6 cleaved the N terminus of tau in vitro, preventing immunoreactivity with both Tau-12 and 5A6. Mass spectrometry confirmed that the in vitro caspase-6 truncation site is D13, a semicanonical and hitherto undescribed caspase cleavage site in tau. Collectively, these results suggest a role for caspase-6 and N-terminal truncation of tau during neurofibrillary tangle evolution and the progression of Alzheimer's disease.

    Funded by: NIA NIH HHS: AG09466, AG10161, AG13854, AG15819, AG20418, AG20506, AG21661

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2004;24;36;7895-902

  • Frequency of tau mutations in familial and sporadic frontotemporal dementia and other tauopathies.

    Stanford PM, Brooks WS, Teber ET, Hallupp M, McLean C, Halliday GM, Martins RN, Kwok JB and Schofield PR

    Garvan Institute for Medical Research, 384 Victoria Street, Sydney, 2010, Australia.

    Tau gene mutations with insoluble Tau neuropathology have been identified in pedigrees with frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). Other neurodegenerative diseases, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), are also characterised by insoluble Tau neuropathology. This study sought to determine the nature and frequency of tau gene mutations in an affected proband cohort of patients within this spectrum of neurodegenerative diseases. Sixty-four individuals with clinical features consistent with FTD and other tauopathies were referred over a three year period. There was neuropathological confirmation of disease in 30%. Individuals were screened for mutations in the coding region and flanking intronic regions of the tau gene by direct sequencing of PCR products. Four confirmed tau gene mutations were identified representing 6.3 % for the total affected proband cohort. Tau gene mutations were found in three of twelve (25%) of the cases with a family history of dominantly inherited frontotemporal dementia, but in only one of 25 cases without a family history (4 %). Although tauopathies have been considered to result from genetic defects, screening for tau gene mutations in sporadic cases is not likely to identify pathogenic mutations.

    Journal of neurology 2004;251;9;1098-104

  • Linkage disequilibrium and haplotype tagging polymorphisms in the Tau H1 haplotype.

    Oliveira SA, Scott WK, Zhang F, Stajich JM, Fujiwara K, Hauser M, Scott BL, Pericak-Vance MA, Vance JM and Martin ER

    Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.

    We and others have previously detected association of the Tau H1 haplotype on chromosome 17 with risk of idiopathic Parkinson disease (PD). The H1 haplotype appears to have a fundamental importance in neurodegeneration, as multiple studies have shown it is also associated with an increased risk for progressive supranuclear palsy, corticobasal degeneration, frontotemporal lobar degeneration syndromes, and primary progressive aphasia. Therefore, to divide the H1 haplotype into sub-haplotypes that could be more significantly associated with the risk of developing PD, and to delimit the genes lying in the H1 haplotype, we analyzed 34 single nucleotide polymorphisms (SNPs) spanning over 3.15 megabases in the region containing Tau. These SNPs are located in or flank the corticotropin-releasing hormone receptor 1, presenilin homolog 2, Tau, Saitohin, and KIAA1267 genes. Analysis of linkage disequilibrium (LD) using these 34 SNPs suggests that the H1 haplotype extends over about 1.3 megabases, making it the largest region of LD reported to date. Of the 29 SNPs lying in this region of LD, 5 were identified as "haplotype tagging" SNPs (htSNPs), capturing 96% of the sample's haplotype diversity. Association analysis with these htSNPs revealed a new H1 sub-haplotype that is significantly associated with PD ( P<0.02). These results define the genes and regulatory regions included in this region of LD, containing an important susceptibility allele contributing to increased risk of neurodegeneration.

    Funded by: NIA NIH HHS: 1R01-AG-20135-01; NINDS NIH HHS: 5 P50 NS39764

    Neurogenetics 2004;5;3;147-55

  • Large-scale characterization of HeLa cell nuclear phosphoproteins.

    Beausoleil SA, Jedrychowski M, Schwartz D, Elias JE, Villén J, Li J, Cohn MA, Cantley LC and Gygi SP

    Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.

    Determining the site of a regulatory phosphorylation event is often essential for elucidating specific kinase-substrate relationships, providing a handle for understanding essential signaling pathways and ultimately allowing insights into numerous disease pathologies. Despite intense research efforts to elucidate mechanisms of protein phosphorylation regulation, efficient, large-scale identification and characterization of phosphorylation sites remains an unsolved problem. In this report we describe an application of existing technology for the isolation and identification of phosphorylation sites. By using a strategy based on strong cation exchange chromatography, phosphopeptides were enriched from the nuclear fraction of HeLa cell lysate. From 967 proteins, 2,002 phosphorylation sites were determined by tandem MS. This unprecedented large collection of sites permitted a detailed accounting of known and unknown kinase motifs and substrates.

    Funded by: NHGRI NIH HHS: HG00041, K22 HG000041, T32 HG000041; NIGMS NIH HHS: GM67945, GMS6203, R01 GM056203, R01 GM067945

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;33;12130-5

  • Novel haplotypes in 17q21 are associated with progressive supranuclear palsy.

    Pastor P, Ezquerra M, Perez JC, Chakraverty S, Norton J, Racette BA, McKeel D, Perlmutter JS, Tolosa E and Goate AM

    Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.

    Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are sporadic neurodegenerative diseases presenting as atypical parkinsonian disorders, characterized by the presence of tau-positive neurofibrillary tangles. Recently, an extended haplotype (H1E) of 787.6 kb that comprises several genes including MAPT showed increased association with PSP. The objective of this study was to determine the size of the H1E haplotype associated with PSP and CBD in different populations and to identify specific subhaplotypes in the background of H1E haplotype. Nineteen single nucleotide polymorphisms (SNPs) in the 17q21 region were genotyped in two case-control samples. The SNPs that were associated with higher risk for the disease in the homozygous state delimit a region of more that 1 Mb. Haplotype analyses in the Spanish sample showed that the most frequent haplotype found among the patients (H1E'), which extends 1.04 Mb and contains several genes such as MAPT, CRHR1, IMP5, Saitohin, WTN3, and NSF. A specific subhaplotype (H1E'A) was present in 16% of PSP patients but was not observed in the controls. Furthermore, the H2E'A haplotype, was rarely present in the disease group suggesting that it plays a protective role. The identification of these specific subhaplotypes that modify risk for PSP/CBD supports the hypothesis that a pathogenic allele exists in a subgroup of PSP patients.

    Funded by: NIA NIH HHS: AG03991, AG05681

    Annals of neurology 2004;56;2;249-58

  • Prevalence of pathogenic mutations in an Italian clinical series of patients with familial dementia.

    Signorini S, Ghidoni R, Barbiero L, Benussi L and Binetti G

    Neurobiology Lab. and Memory Clinic, IRCCS Centro S. Giovanni di Dio-Fatebenefratelli, via Pilastroni 4, 25123 Brescia, Italy.

    Genetic factors are involved in the aetiology of dementias. Three genes have been identified which, when mutated, cause Familial Alzheimer disease (FAD): the presenilin-1 (PS1), the presenilin-2 (PS2) and the amyloid precursor protein (APP) genes. Together, these mutations are responsible for 30-50% of the cases with autosomal dominant Alzheimer disease (AD), and for about 5% of all AD cases. While over 130 mutations have been identified in PS1, mutations in PS2 and APP are rarer, since only 10 and 22 mutations, respectively, have been found in these FAD genes. Instead, mutations in the MAPT gene were associated with Familial Frontotemporal dementia (FFTD) linked to chromosome 17 (FTDP-17). Frontotemporal dementia (FTD) can occur in a sporadic form, but in 30-50% of cases there is a positive family history of dementia. In this study, we determined the spectrum of mutations and the relative contribution of the above mentioned four genes in our Italian clinical series of patients with a positive family history of dementia.

    Current Alzheimer research 2004;1;3;215-8

  • TAU mutations are not a predominant cause of frontotemporal dementia in Canadian patients.

    Levchenko A, Robitaille Y, Strong MJ and Rouleau GA

    Center for Research in Neuroscience, McGill University Health Center Research Institute, Montreal, Quebec, Canada.

    Objective: Frontotemporal dementia is a neurodegenerative disease affecting mostly the frontal and/or temporal lobes, with neuronal loss and intraneuronal and/or intraglial inclusions composed of hyperphosphorylated microtubule-associated protein tau and ubiquitin. Missense and splice site mutations in the TAU gene have been identified in approximately 15% of all frontotemporal dementia cases. In this study, we evaluated the involvement of mutations in the TAU gene in development of frontotemporal dementia phenotype in patients of French or English Canadian origins.

    Methods: Fourteen patients with frontotemporal dementia phenotype and 98 normal controls were recruited for the study. The TAU gene was screened by sequencing and denaturing high performance liquid chromatography.

    Results: No mutations, except some new polymorphisms, were detected in the TAU gene of these patients. One polymorphism, however, may play a role in pathogenesis.

    Conclusion: Our results agree with previous work suggesting that mutations in this gene are not a frequent cause of the frontotemporal dementia phenotype in Canadian patients.

    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 2004;31;3;363-7

  • O-GlcNAcylation regulates phosphorylation of tau: a mechanism involved in Alzheimer's disease.

    Liu F, Iqbal K, Grundke-Iqbal I, Hart GW and Gong CX

    Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.

    Microtubule-associated protein tau is abnormally hyperphosphorylated and aggregated into neurofibrillary tangles in brains of individuals with Alzheimer's disease (AD) and other tauopathies. Tau pathology is critical to pathogenesis and correlates to the severity of dementia. However, the mechanisms leading to abnormal hyperphosphorylation are unknown. Here, we demonstrate that human brain tau was modified by O-GlcNAcylation, a type of protein O-glycosylation by which the monosaccharide beta-N-acetylglucosamine (GlcNAc) attaches to serine/threonine residues via an O-linked glycosidic bond. O-GlcNAcylation regulated phosphorylation of tau in a site-specific manner both in vitro and in vivo. At most of the phosphorylation sites, O-GlcNAcylation negatively regulated tau phosphorylation. In an animal model of starved mice, low glucose uptake/metabolism that mimicked those observed in AD brain produced a decrease in O-GlcNAcylation and consequent hyperphosphorylation of tau at the majority of the phosphorylation sites. The O-GlcNAcylation level in AD brain extracts was decreased as compared to that in controls. These results reveal a mechanism of regulation of tau phosphorylation and suggest that abnormal hyperphosphorylation of tau could result from decreased tau O-GlcNAcylation, which probably is induced by deficient brain glucose uptake/metabolism in AD and other tauopathies.

    Funded by: NIA NIH HHS: AG16760, AG19158, R01 AG016760, R01 AG019158; NICHD NIH HHS: HD13563, R37 HD013563

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;29;10804-9

  • Down-regulation of WW domain-containing oxidoreductase induces Tau phosphorylation in vitro. A potential role in Alzheimer's disease.

    Sze CI, Su M, Pugazhenthi S, Jambal P, Hsu LJ, Heath J, Schultz L and Chang NS

    Department of Pathology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.

    Numerous enzymes hyperphosphorylate Tau in vivo, leading to the formation of neurofibrillary tangles (NFTs) in the neurons of Alzheimer's disease (AD). Compared with age-matched normal controls, we demonstrated here that the protein levels of WW domain-containing oxidoreductase WOX1 (also known as WWOX or FOR), its Tyr33-phosphorylated form, and WOX2 were significantly down-regulated in the neurons of AD hippocampi. Remarkably knock-down of WOX1 expression by small interfering RNA in neuroblastoma SK-N-SH cells spontaneously induced Tau phosphorylation at Thr212/Thr231 and Ser515/Ser516, enhanced phosphorylation of glycogen synthase kinase 3beta (GSK-3beta) and ERK, and enhanced NFT formation. Also an increased binding of phospho-GSK-3beta with phospho-Tau was observed in these WOX1 knock-down cells. In comparison, increased phosphorylation of Tau, GSK-3beta, and ERK, as well as NFT formation, was observed in the AD hippocampi. Activation of JNK1 by anisomycin further increased Tau phosphorylation, and SP600125 (a JNK inhibitor) and PD-98059 (an MEK1/2 inhibitor) blocked Tau phosphorylation and NFT formation in these WOX1 knock-down cells. Ectopic or endogenous WOX1 colocalized with Tau, JNK1, and GSK-3beta in neurons and cultured cells. 17Beta-estradiol, a neuronal protective hormone, increased the binding of WOX1 and GSK-3beta with Tau. Mapping analysis showed that WOX1 bound Tau via its COOH-terminal short-chain alcohol dehydrogenase/reductase domain. Together WOX1 binds Tau via its short-chain alcohol dehydrogenase/reductase domain and is likely to play a critical role in regulating Tau hyperphosphorylation and NFT formation in vivo.

    The Journal of biological chemistry 2004;279;29;30498-506

  • Template-assisted filament growth by parallel stacking of tau.

    Margittai M and Langen R

    Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089-2821, USA.

    Tau filaments are found in >20 neurodegenerative diseases. Yet, because of their enormous molecular weights and poor tendency to form highly ordered 3D crystal lattices, they have evaded high-resolution structure determination. Here, we studied 25 derivatized tau mutants by using electron paramagnetic resonance and fluorescence spectroscopy to report structural details of tau filaments. Based on strong spin exchange and pyrene excimer formation of core residues, we find that individual tau proteins form single molecule layers along the fiber axis that perfectly stack on top of each other by in-register, parallel alignment of beta-strands. We suggest a model of filament growth wherein the existing filament serves as a template for the incoming, unfolded tau molecule, resulting in a new structured layer with maximized hydrogen-bonded contact surface and side-chain stacking.

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;28;10278-83

  • A minimal length between tau exon 10 and 11 is required for correct splicing of exon 10.

    Yu Q, Guo J and Zhou J

    Department of Medicine and Program in Neuroscience, University of Massachusetts Medical School, Worcester, Massachusetts, USA.

    Mutations that stimulate exon 10 inclusion into the human tau mRNA cause frontotemporal dementia with parkinsonism, associated with chromosome 17 (FTDP-17), and other tauopathies. This suggests that the ratio of exon 10 inclusion to exclusion in adult brain is one of the factors to determine biological functions of the tau protein. To investigate the underlying splicing mechanism and identify potential therapeutic targets for tauopathies, we generated a series of mini-gene constructs with intron deletions from the full length of tau exons 9-11 mini-gene construct. RT-PCR results demonstrate that there is a minimum distance requirement between exon 10 and 11 for correct splicing of the exon 10. In addition, SRp20, a member of serine-arginine (SR) protein family of splicing factors was found to facilitate exclusion of exon 10 in a dosage-dependent manner. Significantly, SRp20 also induced exon 10 skipping from pre-mRNAs containing mutations identified in FTDP-17 patients. Based on those results, we generated a cell-based system to measure inclusion to exclusion of exon 10 in the tau mRNA using the luciferase reporter. The firefly luciferase was fused into exon 11 in frame, and a stop code was also created in exon 10. Inclusion of exon 10 prevents luciferase expression, whereas exclusion of exon 10 generates luciferase activity. To minimize baseline luciferase expression, our reporter construct also contains a FTDP-17 mutation that increases exon 10 inclusion. We demonstrate that the splicing pattern of our reporter construct mimics that of endogenous tau gene. Co-transfection of SRp20 and SRp55, two SR proteins that promote exon 10 exclusion, increases production of luciferase. We conclude that this cell-based system can be used to identify biological substances that modulate exon 10 splicing.

    Funded by: NINDS NIH HHS: NS-45351

    Journal of neurochemistry 2004;90;1;164-72

  • Novel isoforms of tau that lack the microtubule-binding domain.

    Luo MH, Tse SW, Memmott J and Andreadis A

    Neurobiology Division, Shriver Center, Waltham, Massachusetts 02452, USA.

    Tau is a microtubule-associated protein (MAP) whose transcript undergoes complex regulated splicing in the mammalian nervous system. Our previous work with exon 6 established that tau shows a unique expression pattern and splicing regulation profile, and that it utilizes alternative splice sites in several human tissues. The mRNAs from these splicing events, if translated, would result in truncated tau variants that lack the microtubule-binding domain. In this study, we demonstrate that at least one of these tau variants is present as a stable protein in several tissues. The novel isoform shows a localization distinct from that of canonical tau in SH-SY5Y neuroblastoma cells which stably overexpress it. In both normal and Alzheimer's hippocampus, the novel isoform is found in dentate gyrus granular cells and CA1/CA3 pyramidal cells. However, it does not co-localize with canonical tau but, rather, partly co-localizes with MAP2.

    Funded by: NICHD NIH HHS: P01 HD05515; NIMH NIH HHS: R24 MH068855

    Journal of neurochemistry 2004;90;2;340-51

  • Phosphorylation of microtubule-associated protein tau by isoforms of c-Jun N-terminal kinase (JNK).

    Yoshida H, Hastie CJ, McLauchlan H, Cohen P and Goedert M

    MRC Laboratory of Molecular Biology, Cambridge, UK. hiro@mrc-lmb.cam.ac.uk

    Microtubule-associated protein tau in a hyperphosphorylated state is the major component of the filamentous lesions that define a number of neurodegenerative diseases commonly referred to as tauopathies. Hyperphosphorylation of tau at most sites appears to precede filament assembly. Many of the hyperphosphorylated sites are serine/threonine-proline sequences. Here we show that c-Jun N-terminal kinases JNK1, JNK2 and JNK3 phosphorylate tau at many serine/threonine-prolines, as assessed by the generation of the epitopes of phosphorylation-dependent anti-tau antibodies. Of the three protein kinases, JNK2 phosphorylated the most sites in tau, followed by JNK3 and JNK1. Phosphorylation by JNK isoforms resulted in a greatly reduced ability of tau to promote microtubule assembly. These findings extend the number of candidate protein kinases for the hyperphosphorylation of tau in Alzheimer's disease and other neurodegenerative disorders.

    Journal of neurochemistry 2004;90;2;352-8

  • Tau gene and Parkinson's disease: a case-control study and meta-analysis.

    Healy DG, Abou-Sleiman PM, Lees AJ, Casas JP, Quinn N, Bhatia K, Hingorani AD and Wood NW

    Department of Molecular Neuroscience, Institute of Neurology, Queen Square, London, UK.

    Objective: To investigate whether the tau H1 haplotype is a genetic risk factor in Parkinson's disease and to report a meta-analysis on all previously published data

    Methods: and results: In a sample of 580 patients with Parkinson's disease and 513 controls there was an increased risk of Parkinson's disease for both the tau H1 haplotype (p<or=0.0064; odds ratio (OR) 1.34 (95% confidence interval (CI), 1.04 to 1.72)) and the H1H1 genotype (p<or=0.0047; OR 1.42 (1.1 to 1.83)). Under a fixed effect model, the summary OR for this showed that individuals homozygous for the H1 allele were 1.57 times more likely to develop Parkinson's disease than individuals carrying the H2 allele (95% CI 1.33 to 1.85; p<0.00001). The population attributable risk for the tau variant, for the main comparison of H1H1 against H2 carriers, was 24.8% for all studies combined.

    Conclusions: Homozygosity for the tau H1 is associated with an increased risk of Parkinson's disease. This adds to the growing body of evidence that common genetic variation contributes to the pathogenesis of this disorder.

    Funded by: Parkinson's UK: G-4029

    Journal of neurology, neurosurgery, and psychiatry 2004;75;7;962-5

  • The structure of the tau haplotype in controls and in progressive supranuclear palsy.

    Pittman AM, Myers AJ, Duckworth J, Bryden L, Hanson M, Abou-Sleiman P, Wood NW, Hardy J, Lees A and de Silva R

    Reta Lila Weston Institute of Neurological Studies, University College London, UK.

    The group of neurodegenerative diseases collectively known as tauopathies are characterized by hallmark lesions consisting of fibrillar aggregates of the microtubule-associated protein, tau (MAPT). Mutations of the tau gene (MAPT) are the cause of frontotemporal dementia with parkinsonism linked to chromosome 17, giving tau a central role in the pathogenic process. The chromosomal region containing MAPT has been shown to evolve into two major haplotypes, H1 and H2, which are defined by linkage disequilibrium (LD) between several polymorphisms over the entire MAPT gene. Studies to date suggest a complete absence of recombination between these two haplotypes. The more common haplotype H1 is over-represented in patients with progressive supranuclear palsy (PSP) and corticobasal degeneration. Using single nucleotide polymorphisms, we mapped LD in the regions flanking MAPT and have established the maximum extent of the haplotype block on chromosome 17q21.31 as a region covering approximately 2 Mb. This gene-rich region extends centromerically beyond the corticotrophin releasing hormone receptor 1 gene (CRHR1) to a region of approximately 400 kb, where there is a complete loss of LD. The telomeric end is defined by an approximately 150 kb region just beyond the WNT3 gene. We show that the entire, fully extended H1 haplotype is associated with PSP, which implicates several other genes in addition to MAPT, as candidate pathogenic loci.

    Funded by: Parkinson's UK: G-4029

    Human molecular genetics 2004;13;12;1267-74

  • Modulation of microtubule dynamics by tau in living cells: implications for development and neurodegeneration.

    Bunker JM, Wilson L, Jordan MA and Feinstein SC

    Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, USA.

    The neural microtubule-associated protein tau binds to and stabilizes microtubules. Because of alternative mRNA splicing, tau is expressed with either 3 or 4 C-terminal repeats. Two observations indicate that differences between these tau isoforms are functionally important. First, the pattern of tau isoform expression is tightly regulated during development. Second, mutation-induced changes in tau RNA splicing cause neuronal cell death and dementia simply by altering the isoform expression ratio. To investigate whether 3- and 4-repeat tau differentially regulate microtubule behavior in cells, we microinjected physiological levels of these two isoforms into EGFP-tubulin-expressing cultured MCF7 cells and measured the effects on the dynamic instability behavior of individual microtubules by time-lapse microscopy. Both isoforms suppressed microtubule dynamics, though to different extents. Specifically, 4-repeat tau reduced the rate and extent of both growing and shortening events. In contrast, 3-repeat tau stabilized most dynamic parameters about threefold less potently than 4-repeat tau and had only a minimal ability to suppress shortening events. These differences provide a mechanistic rationale for the developmental shift in tau isoform expression and are consistent with a loss-of-function model in which abnormal tau isoform expression results in the inability to properly regulate microtubule dynamics, leading to neuronal cell death and dementia.

    Funded by: NCI NIH HHS: CA57291; NINDS NIH HHS: NS13560, NS35010

    Molecular biology of the cell 2004;15;6;2720-8

  • Retarded axonal transport of R406W mutant tau in transgenic mice with a neurodegenerative tauopathy.

    Zhang B, Higuchi M, Yoshiyama Y, Ishihara T, Forman MS, Martinez D, Joyce S, Trojanowski JQ and Lee VM

    The Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, and Institute on Aging, The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4283, USA.

    Intracellular accumulations of filamentous tau inclusions are neuropathological hallmarks of neurodegenerative diseases known as tauopathies. The discovery of multiple pathogenic tau gene mutations in many kindreds with familial frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) unequivocally confirmed the central role of tau abnormalities in the etiology of neurodegenerative disorders. To examine the effects of tau gene mutations and the role of tau abnormalities in neurodegenerative tauopathies, transgenic (Tg) mice were engineered to express the longest human tau isoform (T40) with or without the R406W mutation (RW and hWT Tg mice, respectively) that is pathogenic for FTDP-17 in several kindreds. RW but not hWT tau Tg mice developed an age-dependent accumulation of insoluble filamentous tau aggregates in neuronal perikarya of the cerebral cortex, hippocampus, cerebellum, and spinal cord. Significantly, CNS axons in RW mice contained reduced levels of tau when compared with hWT mice, and this was linked to retarded axonal transport and increased accumulation of an insoluble pool of RW but not hWT tau. Furthermore, RW but not hWT mice demonstrated neurodegeneration and a reduced lifespan. These data indicate that the R406W mutation causes reduced binding of this mutant tau to microtubules, resulting in slower axonal transport. This altered tau function caused by the RW mutation leads to increased accumulation and reduced solubility of RW tau in an age-dependent manner, culminating in the formation of filamentous intraneuronal tau aggregates similar to that observed in tauopathy patients.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2004;24;19;4657-67

  • GSK-3beta inhibition reverses axonal transport defects and behavioural phenotypes in Drosophila.

    Mudher A, Shepherd D, Newman TA, Mildren P, Jukes JP, Squire A, Mears A, Drummond JA, Berg S, MacKay D, Asuni AA, Bhat R and Lovestone S

    Department of Neuroscience and Old Age Psychiatry, Institute of Psychiatry, Kings College London, De Crespigny Park, London, UK.

    The tauopathies are a group of disorders characterised by aggregation of the microtubule-associated protein tau and include Alzheimer's disease (AD) and the fronto-temporal dementias (FTD). We have used Drosophila to analyse how tau abnormalities cause neurodegeneration. By selectively co-expressing wild-type human tau (0N3R isoform) and a GFP vesicle marker in motorneurons, we examined the consequences of tau overexpression on axonal transport in vivo. The results show that overexpression of tau disrupts axonal transport causing vesicle aggregation and this is associated with loss of locomotor function. All these effects occur without neuron death. Co-expression of constitutively active glycogen-synthase kinase-3beta (GSK-3beta) enhances and two GSK-3beta inhibitors, lithium and AR-A014418, reverse both the axon transport and locomotor phenotypes, suggesting that the pathological effects of tau are phosphorylation dependent. These data show that tau abnormalities significantly disrupt neuronal function, in a phosphorylation-dependent manner, before the classical pathological hallmarks are evident and also suggest that the inhibition of GSK-3beta might have potential therapeutic benefits in tauopathies.

    Molecular psychiatry 2004;9;5;522-30

  • Tau epitope display in progressive supranuclear palsy and corticobasal degeneration.

    Berry RW, Sweet AP, Clark FA, Lagalwar S, Lapin BR, Wang T, Topgi S, Guillozet-Bongaarts AL, Cochran EJ, Bigio EH and Binder LI

    Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Chicago, IL 60611, USA. r-berry@northwestern.edu

    Filamentous aggregates of the protein tau are a prominent feature of Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). However, the extent to which the molecular structure of the tau in these aggregates is similar or differs between these diseases is unclear. We approached this question by examining these disorders with a panel of antibodies that represent different structural, conformational, and cleavage-specific tau epitopes. Although each of these antibodies reveals AD pathology, they resolved into three classes with respect to PSP and CBD: AD2 and Tau-46.1 stained the most tau pathology in all cases; Tau-1, 2, 5, and 12 exhibited variable reactivity; and Tau-66 and MN423 did not reveal any tau pathology. In addition, hippocampal neurofibrillary tangles in these cases showed a predominantly PSP/CBD-like, rather than AD-like, staining pattern. These results indicate that the patterns of the tau epitopes represented by this panel that reside in the pathological aggregates of PSP and CBD are similar to each other but distinct from that of AD.

    Funded by: NIA NIH HHS: P01 AG021184, P01 AG09466, P30 AG10161, P30 AG13854

    Journal of neurocytology 2004;33;3;287-95

  • Evidence for two distinct binding sites for tau on microtubules.

    Makrides V, Massie MR, Feinstein SC and Lew J

    Neuroscience Research Institute, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.

    The microtubule-associated protein tau regulates diverse and essential microtubule functions, from the nucleation and promotion of microtubule polymerization to the regulation of microtubule polarity and dynamics, as well as the spacing and bundling of axonal microtubules. Thermodynamic studies show that tau interacts with microtubules in the low- to mid-nanomolar range, implying moderate binding affinity. At the same time, it is well established that microtubule-bound tau does not undergo exchange with the bulk medium readily, suggesting that the tau-microtubule interaction is essentially irreversible. Given this dilemma, we investigated the mechanism of interaction between tau and microtubules in kinetic detail. Stopped-flow kinetic analysis reveals moderate binding affinity between tau and preassembled microtubules and rapid dissociation/association kinetics. In contrast, when microtubules are generated by copolymerization of tubulin and tau, a distinct population of microtubule-bound tau is observed, the binding of which seems irreversible. We propose that reversible binding occurs between tau and the surface of preassembled microtubules, whereas irreversible binding results when tau is coassembled with tubulin into a tau-microtubule copolymer. Because the latter is expected to be physiologically relevant, its characterization is of central importance.

    Funded by: NIGMS NIH HHS: GM58445, R01 GM058445

    Proceedings of the National Academy of Sciences of the United States of America 2004;101;17;6746-51

  • Binding of tau to heat shock protein 27 leads to decreased concentration of hyperphosphorylated tau and enhanced cell survival.

    Shimura H, Miura-Shimura Y and Kosik KS

    Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.

    Pathological hyperphosphorylated tau is the principal component of paired helical filaments, a pathological hallmark of Alzheimer disease (AD) and a strong candidate for a neurotoxic role in AD and other neurodegenerative disorders. Here we show that heat shock protein 27 (Hsp27) preferentially binds pathological hyperphosphorylated tau and paired helical filaments tau directly but not non-phosphorylated tau. The formation of this complex altered the conformation of pathological hyperphosphorylated tau and reduced its concentration by facilitating its degradation and dephosphorylation. Moreover, Hsp27 rescues pathological hyperphosphorylated tau-mediated cell death. Therefore, Hsp27 is likely to provide a neuroprotective effect in AD and other tauopathies.

    The Journal of biological chemistry 2004;279;17;17957-62

  • Casein kinase 1 delta phosphorylates tau and disrupts its binding to microtubules.

    Li G, Yin H and Kuret J

    Center for Molecular Neurobiology, Ohio State Biochemistry Program, Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210, USA.

    Tau hyperphosphorylation precedes neuritic lesion formation in Alzheimer's disease, suggesting it participates in the tau fibrillization reaction pathway. Candidate tau protein kinases include members of the casein kinase 1 (CK1) family of phosphotransferases, which are highly overexpressed in Alzheimer's disease brain and colocalize with neuritic and granulovacuolar lesions. Here we characterized the contribution of one CK1 isoform, Ckidelta, to the phosphorylation of tau at residues Ser202/Thr205 and Ser396/Ser404 in human embryonic kidney 293 cells using immunodetection and fluorescence microscopy. Treatment of cells with membrane permeable CK1 inhibitor 3-[(2,3,6-trimethoxyphenyl)methylidenyl]-indolin-2-one (IC261) lowered occupancy of Ser396/Ser404 phosphorylation sites by >70% at saturation, suggesting that endogenous CK1 was the major source of basal phosphorylation activity at these sites. Overexpression of Ckidelta increased CK1 enzyme activity and further raised tau phosphorylation at residues Ser202/Thr205 and Ser396/Ser404 in situ. Inhibitor IC261 reversed tau hyperphosphorylation induced by Ckidelta overexpression. Co-immunoprecipitation assays showed direct association of tau and Ckidelta in situ, consistent with tau being a Ckidelta substrate. Ckidelta overexpression also produced a decrease in the fraction of bulk tau bound to detergent-insoluble microtubules. These results suggest that Ckidelta phosphorylates tau at sites that modulate tau/microtubule binding, and that the expression pattern of Ckidelta in Alzheimer's disease is consistent with it playing an important role in tau aggregation.

    Funded by: NIA NIH HHS: AG14452

    The Journal of biological chemistry 2004;279;16;15938-45

  • Role of tau phosphorylation by glycogen synthase kinase-3beta in the regulation of organelle transport.

    Tatebayashi Y, Haque N, Tung YC, Iqbal K and Gr