Author
Mitsutoshi Yamamoto
Bio: Mitsutoshi Yamamoto is an academic researcher from Osaka University. The author has contributed to research in topics: Placebo & Parkinson's disease. The author has an hindex of 21, co-authored 32 publications receiving 3351 citations.
Papers
More filters
••
TL;DR: The results identify two new PD susceptibility loci, show involvement of autosomal dominant parkinsonism loci in typical PD and suggest that population differences contribute to genetic heterogeneity in PD.
Abstract: To identify susceptibility variants for Parkinson's disease (PD), we performed a genome-wide association study (GWAS) and two replication studies in a total of 2,011 cases and 18,381 controls from Japan. We identified a new susceptibility locus on 1q32 (P = 1.52 x 10(-12)) and designated this as PARK16, and we also identified BST1 on 4p15 as a second new risk locus (P = 3.94 x 10(-9)). We also detected strong associations at SNCA on 4q22 (P = 7.35 x 10(-17)) and LRRK2 on 12q12 (P = 2.72 x 10(-8)), both of which are implicated in autosomal dominant forms of parkinsonism. By comparing results of a GWAS performed on individuals of European ancestry, we identified PARK16, SNCA and LRRK2 as shared risk loci for PD and BST1 and MAPT as loci showing population differences. Our results identify two new PD susceptibility loci, show involvement of autosomal dominant parkinsonism loci in typical PD and suggest that population differences contribute to genetic heterogeneity in PD.
1,206 citations
••
TL;DR: Clinical and genetic information of 5 Japanese patients with Bardet-Biedl syndrome is summarized and it is found that rare liver fibrosis was detected in two patients, while only two patients had renal dysfunction, thought to be a universal symptom.
456 citations
••
University of Tokyo1, Max Planck Society2, Tokyo University of Technology3, Niigata University4, Kagoshima University5, Nagoya University6, Hokkaido University7, Tohoku University8, Tokyo Medical and Dental University9, Chiba University10, Yokohama City University11, Teikyo University12, Tottori University13, University of Tokushima14, Yamagata University15, Kindai University16, Kōchi University17, St. Marianna University School of Medicine18, Wakayama Medical University19, Juntendo University20, Kobe University21, University of Naples Federico II22, University of Bonn23, University of Sydney24, University of Michigan25, University of California, San Diego26, University of Washington27, University of Pennsylvania28, Mayo Clinic29, Icahn School of Medicine at Mount Sinai30, Indiana University31
TL;DR: Functionally impaired variants of COQ2 were associated with an increased risk of multiple-system atrophy in multiplex families and patients with sporadic disease, providing evidence of a role of impaired COQ1 activities in the pathogenesis of this disease.
Abstract: BACKGROUND
Multiple-system atrophy is an intractable neurodegenerative disease characterized by autonomic failure in addition to various combinations of parkinsonism, cerebellar ataxia, and pyramidal dysfunction. Although multiple-system atrophy is widely considered to be a nongenetic disorder, we previously identified multiplex families with this disease, which indicates the involvement of genetic components.
METHODS
In combination with linkage analysis, we performed whole-genome sequencing of a sample obtained from a member of a multiplex family in whom multiple-system atrophy had been diagnosed on autopsy. We also performed mutational analysis of samples from members of five other multiplex families and from a Japanese series (363 patients and two sets of controls, one of 520 persons and one of 2383 persons), a European series (223 patients and 315 controls), and a North American series (172 patients and 294 controls). On the basis of these analyses, we used a yeast complementation assay and measured enzyme activity of parahydroxybenzoate-polyprenyl transferase. This enzyme is encoded by the gene COQ2 and is essential for the biosynthesis of coenzyme Q10. Levels of coenzyme Q10 in lymphoblastoid cells and brain tissue were measured on high-performance liquid chromatography.
RESULTS
We identified a homozygous mutation (M78V-V343A/M78V-V343A) and compound heterozygous mutations (R337X/V343A) in COQ2 in two multiplex families. Furthermore, we found that a common variant (V343A) and multiple rare variants in COQ2, all of which are functionally impaired, are associated with sporadic multiple-system atrophy. The V343A variant was exclusively observed in the Japanese population.
CONCLUSIONS
Functionally impaired variants of COQ2 were associated with an increased risk of multiple-system atrophy in multiplex families and patients with sporadic disease, providing evidence of a role of impaired COQ2 activities in the pathogenesis of this disease. (Funded by the Japan Society for the Promotion of Science and others.).
284 citations
••
TL;DR: Findings establish SNCA as a definite susceptibility gene for sporadic PD, a major component of Lewy bodies, the pathological hallmark of PD.
Abstract: Parkinson's disease (PD), one of the most common human neurodegenerative diseases, is characterized by the loss of dopaminergic neurons in the substantia nigra of the midbrain. PD is a complex disorder with multiple genetic and environmental factors influencing disease risk. To identify susceptible genes for sporadic PD, we performed case-control association studies of 268 single nucleotide polymorphisms (SNPs) in 121 candidate genes. In two independent case-control populations, we found that a SNP in alpha-synuclein (SNCA), rs7684318, showed the strongest association with PD (P=5.0 x 10(-10)). Linkage disequilibrium (LD) analysis using 29 SNPs in a region around rs7684318 revealed that the entire SNCA gene lies within a single LD block (D'>0.9) spanning approximately 120 kb. A tight LD group (r2>0.85) of six SNPs, including rs7684318, associated most strongly with PD (P=2.0 x 10(-9)-1.7 x 10(-11)). Haplotype association analysis did not show lower P-values than any single SNP within this group. SNCA is a major component of Lewy bodies, the pathological hallmark of PD. Aggregation of SNCA is thought to play a crucial role in PD. SNCA expression levels tended to be positively correlated with the number of the associated allele in autopsied frontal cortices. These findings establish SNCA as a definite susceptibility gene for sporadic PD.
208 citations
••
TL;DR: In this article, a comprehensive resequencing of GBA to identify all sequence variants and to investigate the association of these variants with Parkinson disease was conducted, and 27 pathogenic variants were found in 13 patients with PD but not in the controls, further confirming the role of these rare variants in the susceptibility to PD.
Abstract: Background Increased frequency of pathogenic variants in GBA , the causative gene for Gaucher disease, has been suggested to be associated with Parkinson disease (PD). Objectives To conduct comprehensive resequencing of GBA to identify all sequence variants and to investigate the association of these variants with PD. Design Case-control study. Setting Multicenter university-based study. Participants Five hundred thirty-four patients with PD, 34 families in which multiple patients with PD are present, and 544 control subjects. Main Outcome Measures Disease status and GBA variations. Results Comprehensive resequencing of GBA in 534 patients with PD and 544 controls revealed 27 sequence variants: 11 pathogenic variants associated with Gaucher disease, 11 nonsynonymous variants not associated with Gaucher disease, and 5 synonymous variants. Fifty patients with PD (9.4%) had 1 of the 11 pathogenic variants in the heterozygous state, whereas only 2 controls (0.37%) had such variants (odds ratio, 28.0). Among the pathogenic variants, R120W and L444P/Rec Nci I were highly prevalent, and each showed a significant association with PD. Furthermore, other rare pathogenic variants were found in 13 patients with PD but not in the controls, further confirming the role of these rare variants in the susceptibility to PD. Patients with PD carrying pathogenic variants were significantly younger than those not carrying them. In addition, concordance of PD states and pathogenic variants was observed in 8 multiplex families with PD. Conclusion Heterozygous pathogenic variants in GBA confer a high risk for sporadic PD, even for familial clustering, and are associated with significantly earlier age at onset of disease.
191 citations
Cited by
More filters
••
TL;DR: In this paper, the authors present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macro-autophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes.
Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes.
For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy.
Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagy-related protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.
5,187 citations
••
National Institutes of Health1, University of Tübingen2, University of Coimbra3, University College London4, University of Luxembourg5, University of Lübeck6, Washington University in St. Louis7, University of Bonn8, University of Florida9, University of Kiel10, Baylor College of Medicine11, Scripps Research Institute12, AARP13, Penn State Milton S. Hershey Medical Center14
TL;DR: It is demonstrated that an unequivocal role for common genetic variants in the etiology of typical PD and population-specific genetic heterogeneity in this disease is suggested, and supporting evidence that common variation around LRRK2 modulates risk for PD is provided.
Abstract: 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 a-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 GWAS1, 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.
1,793 citations
••
National Institutes of Health1, University of Minnesota2, Max Planck Society3, University College London4, Paul Sabatier University5, University of Washington6, French Institute of Health and Medical Research7, Boston University8, University of Tübingen9, deCODE genetics10, Columbia University Medical Center11, Erasmus University Rotterdam12, Stanford University13, University of Thessaly14, Washington University in St. Louis15, Michael J. Fox Foundation16, German Center for Neurodegenerative Diseases17, New York State Department of Health18, Centre national de la recherche scientifique19, University of Paris20, University of Miami21, Indiana University22
TL;DR: This article conducted a meta-analysis of Parkinson's disease genome-wide association studies using a common set of 7,893,274 variants across 13,708 cases and 95,282 controls.
Abstract: We conducted a meta-analysis of Parkinson's disease genome-wide association studies using a common set of 7,893,274 variants across 13,708 cases and 95,282 controls. Twenty-six loci were identified as having genome-wide significant association; these and 6 additional previously reported loci were then tested in an independent set of 5,353 cases and 5,551 controls. Of the 32 tested SNPs, 24 replicated, including 6 newly identified loci. Conditional analyses within loci showed that four loci, including GBA, GAK-DGKQ, SNCA and the HLA region, contain a secondary independent risk variant. In total, we identified and replicated 28 independent risk variants for Parkinson's disease across 24 loci. Although the effect of each individual locus was small, risk profile analysis showed substantial cumulative risk in a comparison of the highest and lowest quintiles of genetic risk (odds ratio (OR) = 3.31, 95% confidence interval (CI) = 2.55–4.30; P = 2 × 10−16). We also show six risk loci associated with proximal gene expression or DNA methylation.
1,636 citations
••
National Institutes of Health1, Norwegian University of Science and Technology2, National Research Council3, University of São Paulo4, University of Tübingen5, University of Coimbra6, University of Paris7, French Institute of Health and Medical Research8, Chang Gung University9, Columbia University10, Mayo Clinic11, Tel Aviv University12, Rambam Health Care Campus13, Technion – Israel Institute of Technology14, Tel Aviv Sourasky Medical Center15, University of Rostock16, University Health Network17, National Taiwan Normal University18, University of Washington19, University of Tokyo20, Kobe University21, Magna Græcia University22, University of Toronto23, Duke University24, Singapore General Hospital25
TL;DR: Data collected demonstrate that there is a strong association between GBA mutations and Parkinson's disease, and those with a GBA mutation presented earlier with the disease, were more likely to have affected relatives, and were morelikely to have atypical clinical manifestations.
Abstract: Background Recent studies indicate an increased frequency of mutations in the gene encoding glucocerebrosidase (GBA), a deficiency of which causes Gaucher's disease, among patients with Parkinson's disease. We aimed to ascertain the frequency of GBA mutations in an ethnically diverse group of patients with Parkinson's disease. Methods Sixteen centers participated in our international, collaborative study: five from the Americas, six from Europe, two from Israel, and three from Asia. Each center genotyped a standard DNA panel to permit comparison of the genotyping results across centers. Genotypes and phenotypic data from a total of 5691 patients with Parkinson's disease (780 Ashkenazi Jews) and 4898 controls (387 Ashkenazi Jews) were analyzed, with multivariate logistic-regression models and the Mantel–Haenszel procedure used to estimate odds ratios across centers. Results All 16 centers could detect two GBA mutations, L444P and N370S. Among Ashkenazi Jewish subjects, either mutation was found in 15% of p...
1,629 citations
••
TL;DR: The results identify two new PD susceptibility loci, show involvement of autosomal dominant parkinsonism loci in typical PD and suggest that population differences contribute to genetic heterogeneity in PD.
Abstract: To identify susceptibility variants for Parkinson's disease (PD), we performed a genome-wide association study (GWAS) and two replication studies in a total of 2,011 cases and 18,381 controls from Japan. We identified a new susceptibility locus on 1q32 (P = 1.52 x 10(-12)) and designated this as PARK16, and we also identified BST1 on 4p15 as a second new risk locus (P = 3.94 x 10(-9)). We also detected strong associations at SNCA on 4q22 (P = 7.35 x 10(-17)) and LRRK2 on 12q12 (P = 2.72 x 10(-8)), both of which are implicated in autosomal dominant forms of parkinsonism. By comparing results of a GWAS performed on individuals of European ancestry, we identified PARK16, SNCA and LRRK2 as shared risk loci for PD and BST1 and MAPT as loci showing population differences. Our results identify two new PD susceptibility loci, show involvement of autosomal dominant parkinsonism loci in typical PD and suggest that population differences contribute to genetic heterogeneity in PD.
1,206 citations