研究者詳細 - 小野寺　理

Cerebral small-vessel disease protein HTRA1 controls the amount of TGF-β1 via cleavage of proTGF-β1. 査読

Shiga A, Nozaki H, Yokoseki A, Nihonmatsu M, Kawata H, Kato T, Koyama A, Arima K, Ikeda M, Katada S, Toyoshima Y, Takahashi H, Tanaka A, Nakano I, Ikeuchi T, Nishizawa M, Onodera O

Human molecular genetics 20 ( 9 ) 1800 - 1810 2011年5月

Polyglutamine Diseases: Where does Toxicity Come from? What is Toxicity? Where are We Going? 査読

Toshiaki Takahashi, Shinichi Katada, Osamu Onodera

JOURNAL OF MOLECULAR CELL BIOLOGY 2 ( 4 ) 180 - 191 2010年8月

記述言語：英語出版者・発行元：OXFORD UNIV PRESS

Although the genetic basis of polyglutamine diseases has been recognized for 20 years, their molecular basis is still unclear. We have no therapeutic strategies for these intractable neurodegenerative disorders. To adequately treat patients, we must clarify the molecular basis of polyglutamine diseases. Three main issues address their molecular pathogenesis: whether the specific structure of expanded polyglutamine diseases results in cellular toxicity; what type of dysfunction causes them; and how the toxic structure causes dysfunction, that is, the link between structure and dysfunction. For structures, expanded polyglutamine proteins undergo transformation from monomers to oligomers and inclusions. One can hypothesize that one of these structures might cause the polyglutamine disease. Although the expanded polyglutamine protein is toxic, it does not explain the selective vulnerability of specific neurons in each polyglutamine disease. The normal function of each protein, including protein-protein interaction and modification, might also be crucial for pathogenesis. For dysfunction, various molecular mechanisms have been proposed, including dysregulation of transcription, impairment of the ubiquitin-proteasome system, mitochondrial dysfunction, dysregulation of intracellular Ca2+ homeostasis, impairment of axonal transport and genotoxic stress. These hypotheses might correlate with each other. In addition, the disease pathogenesis of might not be exclusive to one particular structure or dysfunction. To develop a therapeutic strategy for patients with polyglutamine disease, identifying the most toxic structure and the earliest event in the pathogenesis is important. We review the current understanding of the toxic structure and dysfunction by expanded polyglutamine proteins and suggest directions for future studies of polyglutamine diseases.

DOI： 10.1093/jmcb/mjq005

Association of HTRA1 Mutations and Familial Ischemic Cerebral Small-Vessel Disease 査読

Kenju Hara, Atsushi Shiga, Toshio Fukutake, Hiroaki Nozaki, Akinori Miyashita, Akio Yokoseki, Hirotoshi Kawata, Akihide Koyama, Kunimasa Arima, Toshiaki Takahashi, Mari Ikeda, Hiroshi Shiota, Masato Tamura, Yutaka Shimoe, Mikio Hirayama, Takayo Arisato, Sohei Yanagawa, Akira Tanaka, Imaharu Nakano, Shu-ichi Ikeda, Yutaka Yoshida, Tadashi Yamamoto, Takeshi Ikeuchi, Ryozo Kuwano, Masatoyo Nishizawa, Shoji Tsuji, Osamu Onodera

NEW ENGLAND JOURNAL OF MEDICINE 360 ( 17 ) 1729 - 1739 2009年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MASSACHUSETTS MEDICAL SOC

BACKGROUND
The genetic cause of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), which is characterized by ischemic, non-hypertensive, cerebral small-vessel disease with associated alopecia and spondylosis, is unclear.
METHODS
In five families with CARASIL, we carried out linkage analysis, fine mapping of the region implicated in the disease, and sequence analysis of a candidate gene. We also conducted functional analysis of wild-type and mutant gene products and measured the signaling by members of the transforming growth factor beta (TGF-beta) family and gene and protein expression in the small arteries in the cerebrum of two patients with CARASIL.
RESULTS
We found linkage of the disease to the 2.4-Mb region on chromosome 10q, which contains the HtrA serine protease 1 (HTRA1) gene. HTRA1 is a serine protease that represses signaling by TGF-beta family members. Sequence analysis revealed two nonsense mutations and two missense mutations in HTRA1. The missense mutations and one of the nonsense mutations resulted in protein products that had comparatively low levels of protease activity and did not repress signaling by the TGF-beta family. The other nonsense mutation resulted in the loss of HTRA1 protein by nonsense-mediated decay of messenger RNA. Immunohistochemical analysis of the cerebral small arteries in affected persons showed increased expression of the extra domain-A region of fibronectin and versican in the thickened tunica intima and of TGF-beta 1 in the tunica media.
CONCLUSIONS
CARASIL is associated with mutations in the HTRA1 gene. Our findings indicate a link between repressed inhibition of signaling by the TGF-beta family and ischemic cerebral small-vessel disease, alopecia, and spondylosis.

DOI： 10.1056/NEJMoa0801560

TDP-43 mutation in familial amyotrophic lateral sclerosis 査読

Akio Yokoseki, Atsushi Shiga, Chun-Feng Tan, Asako Tagawa, Hiroyuki Kaneko, Akihide Koyama, Hiroto Eguchi, Akira Tsujino, Takeshi Ikeuchi, Akiyoshi Kakita, Koichi Okamoto, Masatoyo Nishizava, Hitoshi Takahashi, Osamu Onodera

ANNALS OF NEUROLOGY 63 ( 4 ) 538 - 542 2008年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. Accumulating evidence has shown that 43kDa TAR-DNA-binding protein (TDP-43) is the disease protein in ALS and frontotemporal lobar degeneration. We previously reported a familial ALS with Bumina bodies and TDP-43-positive skein-like inclusions in the lower motor neurons; these findings are indistinguishable from those of sporadic ALS. In three affected individuals in two generations of one family, we found a single base-pair change from A to G at position 1028 in TDP-43, which resulted in a Gln-to-Arg substitution at position 343. Our findings provide a new insight into the molecular pathogenesis of ALS.

DOI： 10.1002/ana.21392

Soluble polyglutamine oligomers formed prior to inclusion body formation are cytotoxic 査読

Toshiaki Takahashi, Shinya Kikuchi, Shinichi Katada, Yoshitaka Nagai, Masatoyo Nishizawa, Osamu Onodera

HUMAN MOLECULAR GENETICS 17 ( 3 ) 345 - 356 2008年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：OXFORD UNIV PRESS

Expanded polyglutamine (polyQ) repeats cause neurodegenerative disorders, but their cytotoxic structures remain to be elucidated. Although soluble polyQ oligomers have been proposed as a cytotoxic structure, the cytotoxicity of soluble polyQ oligomers, not inclusion bodies (IBs), has not been proven in living cells. To clarify the cytotoxicity of soluble polyQ oligomers, we carried our fluorescence resonance energy transfer (FRET) confocal microscopy and distinguished oligomers from monomers and IBs in a single living cell. FRET signals were detected when donor and acceptor fluorescent proteins were attached to the same side, not the opposite side, of polyQ repeats, which agrees with a parallel beta-sheet or a head-to-tail cylindrical beta-sheet model. These FRET signals disappeared in semi-intact cells, indicating that these polyQ oligomers are soluble. PolyQ monomers assembled into soluble oligomers in a length-dependent manner, which was followed by the formation of IBs. Notably, survival assay of neuronally differentiated cells revealed that cells with soluble oligomers died faster than those with IBs or monomers. These results indicate that a length-dependent formation of oligomers is an essential mechanism underlying neurodegeneration in polyQ-mediated disorders.

DOI： 10.1093/hmg/ddm311

Aprataxin, causative gene product for EAOH/AOA1, repairs DNA single-strand breaks with damaged 3 '-phosphate and 3 '-phosphoglycolate ends 査読

Tetsuya Takahashi, Masayoshi Tada, Shuichi Igarashi, Akihide Koyama, Hidetoshi Date, Akio Yokoseki, Atsushi Shiga, Yutaka Yoshida, Shoji Tsuji, Masatoyo Nishizawa, Osamu Onodera

NUCLEIC ACIDS RESEARCH 35 ( 11 ) 3797 - 3809 2007年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：OXFORD UNIV PRESS

Aprataxin is the causative gene product for early-onset ataxia with ocular motor apraxia and hypoalbuminemia/ ataxia with oculomotor apraxia type 1 (EAOH/AOA1), the clinical symptoms of which are predominantly neurological. Although aprataxin has been suggested to be related to DNA single-strand break repair (SSBR), the physiological function of aprataxin remains to be elucidated. DNA single-strand breaks (SSBs) continually produced by endogenous reactive oxygen species or exogenous genotoxic agents, typically possess damaged 3'-ends including 3'-phosphate, 3'-phosphoglycolate, or 3'-alpha, beta-unsaturated aldehyde ends. These damaged 3'-ends should be restored to 3'-hydroxyl ends for subsequent repair processes. Here we demonstrate by in vitro assay that recombinant human aprataxin specifically removes 3'-phosphoglycolate and 3'-phosphate ends at DNA 3'-ends, but not 3'-alpha, beta-unsaturated aldehyde ends, and can act with DNA polymerase beta and DNA ligase III to repair SSBs with these damaged 3'-ends. Furthermore, disease-associated mutant forms of aprataxin lack this removal activity. The findings indicate that aprataxin has an important role in SSBR, that is, it removes blocking molecules from 3'-ends, and that the accumulation of unrepaired SSBs with damaged 3'-ends underlies the pathogenesis of EAOH/AOA1. The findings will provide new insight into the mechanism underlying degeneration and DNA repair in neurons.

DOI： 10.1093/nar/gkm158

Early development of autonomic dysfunction may predict poor prognosis in patients with multiple system atrophy 査読

Mari Tada, Osamu Onodera, Masayoshi Tada, Tetsutaro Ozawa, Yue-Shan Piao, Akiyoshi Kakita, Hitoshi Takahashi, Masatoyo Nishizawa

ARCHIVES OF NEUROLOGY 64 ( 2 ) 256 - 260 2007年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER MEDICAL ASSOC

Background: Multiple system atrophy (MSA) is diverse in clinical phenotype, disease progression, and prognosis. Sudden death is a leading cause of death in patients with MSA.
Objective: To determine what clinical factors affect the progression and survival prognosis of those with MSA.
Design: A retrospective review of the medical records of 49 consecutive Japanese patients with pathologically confirmed MSA ( 29 men and 20 women; mean +/- SD age at onset, 59.8 +/- 6.5 years). Cox proportional hazards models were used to compare the risks of being in a wheel-chair-bound state, being in a bedridden state, and having a shorter survival.
Results: Thirty-one patients were diagnosed as having cerebellar type MSA, and 18 were diagnosed as having parkinsonian type MSA. Twenty-nine patients with cerebellar type MSA and 17 patients with parkinsonian type MSA had autonomic dysfunction. The median times from disease onset to being in a wheel-chair-bound state, being in a bedridden state, death, and the development of autonomic dysfunction were 3.5, 5.0, 7.0, and 2.5 years, respectively. Patients with an early development of autonomic dysfunction (within 2.5 years from the onset of MSA) had significantly higher risks of being in a wheel-chair-bound state (multivariate-adjusted hazard ratio [HR], 4.32; 95% confidence interval [CI], 2.04-9.15), being in a bedridden state (HR, 3.87; 95% CI, 1.77-8.48), having a shorter survival (HR, 3.40; 95% CI, 1.61-7.15), and sudden death (HR, 7.22; 95% CI, 1.49-35.07).
Conclusion: The early development of autonomic dysfunction is an independent predictive factor for rapid disease progression and shorter survival in patients with MSA.

DOI： 10.1001/archneur.64.2.256

Early-onset ataxia with ocular motor apraxia and hypoalbuminemia is caused by mutations in a new HIT superfamily gene 査読

H Date, O Onodera, H Tanaka, K Iwabuchi, K Uekawa, S Igarashi, R Koike, T Hiroi, T Yuasa, Y Awaya, T Sakai, T Takahashi, H Nagatomo, Y Sekijima, Kawachi, I, Y Takiyama, M Nishizawa, N Fukuhara, K Saito, S Sugano, S Tsuji

NATURE GENETICS 29 ( 2 ) 184 - 188 2001年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE AMERICA INC

Friedreich ataxia (FRDA), the most common autosomal recessive neurodegenerative disease among Europeans and people of European descent, is characterized by an early onset (usually before the age of 25), progressive ataxia, sensory loss, absence of tendon reflexes and pyramidal weakness of the legs(1-4). We have recently identified a unique group of patients whose clinical presentations are characterized by autosomal recessive inheritance, early age of onset, FRDA-like clinical presentations and hypoalbuminemia. Linkage to the FRDA locus, however, was excluded. Given the similarities of the clinical presentations to those of the recently described ataxia with oculomotor apraxia (AOA) linked to chromosome 9p13, we confirmed that the disorder of our patients is also linked to the same locus(5). We narrowed the candidate region and have identified a new gene encoding a member of the histidine triad (HIT) superfamily as the 'causative' gene. We have called its product aprataxin; the gene symbol is APTX. Although many HIT proteins have been identified, aprataxin is the first to be linked to a distinct phenotype.

DOI： 10.1038/ng1001-184

Progressive atrophy of cerebellum and brainstem as a function of age and the size of the expanded CAG repeats in the MJD1 gene in Machado-Joseph disease 査読

O Onodera, J Idezuka, S Igarashi, Y Takiyama, K Endo, H Takano, M Oyake, H Tanaka, T Inuzuka, T Hayashi, T Yuasa, J Ito, T Miyatake, S Tsuji

ANNALS OF NEUROLOGY 43 ( 3 ) 288 - 296 1998年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disease characterized by cerebellar ataxia associated to varying degrees with pyramidal signs, extrapyramidal signs, or peripheral amyotrophy. It is caused by unstable expansion of the CAG repeat in the MJD1 gene on chromosome 14q32.1. To determine how the neurodegenerative process in the central nervous system of patients with MJD correlates with the size of expanded CAG repeats in the MJD1 gene and other factors, we performed detailed quantitative analyses of findings of magnetic resonance imaging of the central nervous system of 21 patients with MJD of various ages and with various sizes of expanded CAG repeats. We found that atrophy of the brainstem and cerebellar vermis in MJD patients is closely correlated not only with the size of expanded CAG repeat in the MJD1 gene but also with patient age, which suggests that the neurodegenerative process in MJD is regulated by the size of expanded CAG repeats as well as by the patient age.

DOI： 10.1002/ana.410430305

Somatic mosaicism of expanded CAG repeats in brains of patients with dentatorubral-pallidoluysian atrophy: Cellular population-dependent dynamics of mitotic instability 査読

H Takano, O Onodera, H Takahashi, S Igarashi, M Yamada, M Oyake, T Ikeuci, R Koide, H Tanaka, K Iwabuchi, S Tsuji

AMERICAN JOURNAL OF HUMAN GENETICS 58 ( 6 ) 1212 - 1222 1996年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：UNIV CHICAGO PRESS

Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disease caused by unstable expansion of a CAG repeat in the DRPLA gene. We performed detailed quantitative analysis of the size and the size distribution (range) of the expanded CAG repeats in various regions of the CNS of eight autopsied patients with DRPLA. Expanded alleles (AE) showed considerable variations in size, as well as in range, depending on the region of the CNS, whereas normal alleles did not show such variations, which indicates the occurrence of somatic mosaicism of AE in the CNS. The AE in the cerebellar cortex were consistently smaller by two to five repeat units than those in the cerebellar white matter. Moreover, the AE in the cerebral cortex were smaller by one to four repeat units than those in the cerebral white matter. These results suggest that the smaller AE in the cerebellar and cerebral cortices represent those of neuronal cells. The ranges of the AE in the cerebral cortex, cerebral white matter, and cerebellar white matter showed considerable variation ranging from 9 to 23 repeat units, whereas those in the cerebellar cortex showed little variance and were similar to 7 repeat units. The ranges of the AE in the cerebral cortex, cerebral white matter, and cerebellar white matter were much broader in patients with higher ages at death than they were in patients with lower ages at death, raising the possibility that the range of AE increases with time, as the result of mitotic instability of AE.

MOLECULAR-CLONING OF A FULL-LENGTH CDNA FOR DENTATORUBRAL-PALLIDOLUYSIAN ATROPHY AND REGIONAL EXPRESSIONS OF THE EXPANDED ALLELES IN THE CNS 査読

O ONODERA, M OYAKE, H TAKANO, T IKEUCHI, S IGARASHI, S TSUJI

AMERICAN JOURNAL OF HUMAN GENETICS 57 ( 5 ) 1050 - 1060 1995年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：UNIV CHICAGO PRESS

Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder characterized by genetic anticipation and variable combinations of symptoms including myoclonus, epilepsy, cerebellar ataxia, choreoathetosis, and dementia. Recently, we discovered that DRPLA is caused by unstable expansion of a CAG repeat of a gene on the short arm of chromosome 12. We determined the consensus DRPLA cDNA sequence containing the complete coding region for 1,185 amino acids. The CAG repeat, which is expanded in DRPLA, is located 1,462 bp downstream from the putative methionine initiation codon and encodes a poly-glutamine tract. Although poly-serine and proline tracts exist near the CAG repeats, these polyserine or proline tracts did not show any polymorphisms, which is in strong contrast to the high heterogeneity in the length of the CAG repeat. Northern blot analysis revealed a 4.7-kb transcript that is widely expressed in various tissues including heart, lung, kidney, placenta, skeletal muscle, and brain. Reverse transcription-PCR analysis revealed that the expanded alleles are transcribed to levels comparable to those of normal alleles. These results indicate that there is no difference in transcriptional efficiency between expanded and normal alleles. Furthermore, mRNA from cerebellar hemispheres of DRPLA patients showed smaller sizes of CAG repeats compared with other regions of the brain, which reflects somatic mosaicism of the expanded alleles of the DRPLA gene.

GENETIC ASSOCIATION OF THE VERY-LOW-DENSITY LIPOPROTEIN (VLDL) RECEPTOR GENE WITH SPORADIC ALZHEIMERS-DISEASE 査読

K OKUIZUMI, O ONODERA, Y NAMBA, K IKEDA, T YAMAMOTO, K SEKI, A UEKI, S NANKO, H TANAKA, H TAKAHASHI, K OYANAGI, H MIZUSAWA, KANAZAWA, I, S TSUJI

NATURE GENETICS 11 ( 2 ) 207 - 209 1995年10月

UNSTABLE EXPANSION OF CAG REPEAT IN HEREDITARY DENTATORUBRAL-PALLIDOLUYSIAN ATROPHY (DRPLA) 査読

R KOIDE, T IKEUCHI, O ONODERA, H TANAKA, S IGARASHI, K ENDO, H TAKAHASHI, R KONDO, A ISHIKAWA, T HAYASHI, M SAITO, A TOMODA, T MIIKE, H NAITO, F IKUTA, S TSUJI

NATURE GENETICS 6 ( 1 ) 9 - 13 1994年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING CO

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurologic disorder characterized by variable combinations of myoclonus, epilepsy, cerebellar ataxia, choreoathetosis and dementia. By specifically searching published brain cDNA sequences for the presence of CAG repeats we identified unstable expansion of a CAG in a gene on chromosome 12 in all the 22 DRPLA patients examined. A good correlation between the size of the CAG repeat expansion and the ages of disease onset is found in this group. Patients with earlier onset tended to have a phenotype of progressive myoclonus epilepsy and larger expansions. We propose that the wide variety of clinical manifestations of DRPLA can now be explained by the variable unstable expansion of the CAG repeat.

DOI： 10.1038/ng0194-9