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Pedersen CC, Lange J, Førland MGG, Macleod AD, Alves G, Maple-Grødem J. A systematic review of associations between common SNCA variants and clinical heterogeneity in Parkinson's disease. NPJ PARKINSONS DISEASE 2021; 7:54. [PMID: 34210990 PMCID: PMC8249472 DOI: 10.1038/s41531-021-00196-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 06/02/2021] [Indexed: 11/09/2022]
Abstract
There is great heterogeneity in both the clinical presentation and rate of disease progression among patients with Parkinson’s disease (PD). This can pose prognostic difficulties in a clinical setting, and a greater understanding of the risk factors that contribute to modify disease course is of clear importance for optimizing patient care and clinical trial design. Genetic variants in SNCA are an established risk factor for PD and are candidates to modify disease presentation and progression. This systematic review aimed to summarize all available primary research reporting the association of SNCA polymorphisms with features of PD. We systematically searched PubMed and Web of Science, from inception to 1 June 2020, for studies evaluating the association of common SNCA variants with age at onset (AAO) or any clinical feature attributed to PD in patients with idiopathic PD. Fifty-eight studies were included in the review that investigated the association between SNCA polymorphisms and a broad range of outcomes, including motor and cognitive impairment, sleep disorders, mental health, hyposmia, or AAO. The most reproducible findings were with the REP1 polymorphism or rs356219 and an earlier AAO, but no clear associations were identified with an SNCA polymorphism and any individual clinical outcome. The results of this comprehensive summary suggest that, while there is evidence that genetic variance in the SNCA region may have a small impact on clinical outcomes in PD, the mechanisms underlying the association of SNCA polymorphisms with PD risk may not be a major factor driving clinical heterogeneity in PD.
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Affiliation(s)
- Camilla Christina Pedersen
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway.,Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway
| | - Johannes Lange
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway.,Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway
| | | | - Angus D Macleod
- Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK
| | - Guido Alves
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway.,Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway.,Department of Neurology, Stavanger University Hospital, Stavanger, Norway
| | - Jodi Maple-Grødem
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway. .,Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway.
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2
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Fernández-Santiago R, Martín-Flores N, Antonelli F, Cerquera C, Moreno V, Bandres-Ciga S, Manduchi E, Tolosa E, Singleton AB, Moore JH, Martí MJ, Ezquerra M, Malagelada C. SNCA and mTOR Pathway Single Nucleotide Polymorphisms Interact to Modulate the Age at Onset of Parkinson's Disease. Mov Disord 2019; 34:1333-1344. [PMID: 31234232 PMCID: PMC7322732 DOI: 10.1002/mds.27770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/25/2019] [Accepted: 05/27/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Single nucleotide polymorphisms (SNPs) in the α-synuclein (SNCA) gene are associated with differential risk and age at onset (AAO) of both idiopathic and Leucine-rich repeat kinase 2 (LRRK2)-associated Parkinson's disease (PD). Yet potential combinatory or synergistic effects among several modulatory SNPs for PD risk or AAO remain largely underexplored. OBJECTIVES The mechanistic target of rapamycin (mTOR) signaling pathway is functionally impaired in PD. Here we explored whether SNPs in the mTOR pathway, alone or by epistatic interaction with known susceptibility factors, can modulate PD risk and AAO. METHODS Based on functional relevance, we selected a total of 64 SNPs mapping to a total of 57 genes from the mTOR pathway and genotyped a discovery series cohort encompassing 898 PD patients and 921 controls. As a replication series, we screened 4170 PD and 3014 controls available from the International Parkinson's Disease Genomics Consortium. RESULTS In the discovery series cohort, we found a 4-loci interaction involving STK11 rs8111699, FCHSD1 rs456998, GSK3B rs1732170, and SNCA rs356219, which was associated with an increased risk of PD (odds ratio = 2.59, P < .001). In addition, we also found a 3-loci epistatic combination of RPTOR rs11868112 and RPS6KA2 rs6456121 with SNCA rs356219, which was associated (odds ratio = 2.89; P < .0001) with differential AAO. The latter was further validated (odds ratio = 1.56; P = 0.046-0.047) in the International Parkinson's Disease Genomics Consortium cohort. CONCLUSIONS These findings indicate that genetic variability in the mTOR pathway contributes to SNCA effects in a nonlinear epistatic manner to modulate differential AAO in PD, unraveling the contribution of this cascade in the pathogenesis of the disease. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Rubén Fernández-Santiago
- Lab of Parkinson Disease and Other Neurodegenerative Movement Disorders, institut d’Investigacions Biomédiques August Pi i Sunyer, Barcelona, Catalonia, Spain
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
- Networked Centre for Biomedical Research of Neurodegenerative Diseases, Madrid, Spain
| | - Núria Martín-Flores
- Department of Biomedicine, Unit of Biochemistry, Universitat de Barcelona, Barcelona, Catalonia, Spain
- institute of Neurosciences, University of Barcelona, Barcelona, Catalonia, Spain
| | - Francesca Antonelli
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
| | - Catalina Cerquera
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
| | - Verónica Moreno
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
| | - Sara Bandres-Ciga
- Laboratory of Neurogenetics, National institute on Aging, National institutes of Health, Bethesda, Maryland, USA
- instituto de investigación Biosanitaria de Granada (ibs. GRANADA), Granada, Spain
| | - Elisabetta Manduchi
- The Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eduard Tolosa
- Lab of Parkinson Disease and Other Neurodegenerative Movement Disorders, institut d’Investigacions Biomédiques August Pi i Sunyer, Barcelona, Catalonia, Spain
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
- Networked Centre for Biomedical Research of Neurodegenerative Diseases, Madrid, Spain
| | - Andrew B. Singleton
- Laboratory of Neurogenetics, National institute on Aging, National institutes of Health, Bethesda, Maryland, USA
| | - Jason H. Moore
- The Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - María-Josep Martí
- Lab of Parkinson Disease and Other Neurodegenerative Movement Disorders, institut d’Investigacions Biomédiques August Pi i Sunyer, Barcelona, Catalonia, Spain
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
- Networked Centre for Biomedical Research of Neurodegenerative Diseases, Madrid, Spain
| | - Mario Ezquerra
- Lab of Parkinson Disease and Other Neurodegenerative Movement Disorders, institut d’Investigacions Biomédiques August Pi i Sunyer, Barcelona, Catalonia, Spain
- Neurology Service, Hospital Clinic de Barcelona, Barcelona, Catalonia, Spain
- Networked Centre for Biomedical Research of Neurodegenerative Diseases, Madrid, Spain
| | - Cristina Malagelada
- Department of Biomedicine, Unit of Biochemistry, Universitat de Barcelona, Barcelona, Catalonia, Spain
- institute of Neurosciences, University of Barcelona, Barcelona, Catalonia, Spain
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Hou B, Zhang X, Liu Z, Wang J, Xie A. Association of rs356219 and rs3822086 polymorphisms with the risk of Parkinson’s disease: A meta-analysis. Neurosci Lett 2019; 709:134380. [DOI: 10.1016/j.neulet.2019.134380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/23/2019] [Accepted: 07/15/2019] [Indexed: 01/07/2023]
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Zhang Y, Shu L, Sun Q, Pan H, Guo J, Tang B. A Comprehensive Analysis of the Association Between SNCA Polymorphisms and the Risk of Parkinson's Disease. Front Mol Neurosci 2018; 11:391. [PMID: 30410434 PMCID: PMC6209653 DOI: 10.3389/fnmol.2018.00391] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 10/05/2018] [Indexed: 12/14/2022] Open
Abstract
Background: Various studies have reported associations between synuclein alpha (SNCA) polymorphisms and Parkinson's disease (PD) risk. However, the results are inconsistent. We conducted a comprehensive meta-analysis of the associations between SNCA single-nucleotide polymorphisms (SNPs) and PD risk in overall populations and subpopulations by ethnicity. Methods: Standard meta-analysis was conducted according to our protocol with a cutoff point of p < 0.05. To find the most relevant SNCA SNPs, we used a cutoff point of p < 1 × 10−5 in an analysis based on the allele model. In the subgroup analysis by ethnicity, we divided the overall populations into five ethnic groups. We conducted further analysis on the most relevant SNPs using dominant and recessive models to identify the contributions of heterozygotes and homozygotes regarding each SNP. Results: In our comprehensive meta-analysis, 24,075 cases and 22,877 controls from 36 articles were included. We included 16 variants in the meta-analysis and found 12 statistically significant variants with p < 0.05. After narrowing down the variants using the p < 1 × 10−5 cutoff, in overall populations, seven SNPs increased the risk of PD (rs2736990, rs356220, rs356165, rs181489, rs356219, rs11931074, and rs2737029, with odds ratios [ORs] of 1.22–1.38) and one SNP decreased the risk (rs356186, with an OR of 0.77). In the East Asian group, rs2736990 and rs11931074 increased the risk (with ORs of 1.22–1.34). In the European group, five SNPs increased the risk (rs356219, rs181489, rs2737029, rs356165, and rs11931074, with ORs of 1.26–1.37) while one SNP decreased the risk (rs356186, with an OR of 0.77). The heterozygotes and homozygotes contributed differently depending on the variant. Conclusions: In summary, we found eight SNCA SNPs associated with PD risk, which had obvious differences between ethnicities. Seven SNPs increased the risk of PD and one SNP decreased the risk in the overall populations. In the East Asian group, rs2736990 and rs11931074 increased the risk. In the European group, rs356219, rs181489, rs2737029, rs356165, and rs11931074 increased the risk while rs356186 decreased the risk. Variants with the highest ORs and allele frequencies in our analysis should be given priority when carrying out genetic screening.
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Affiliation(s)
- Yuan Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Li Shu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qiying Sun
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Hongxu Pan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Parkinson's Disease Center of Beijing Institute for Brain Disorders, Beijing, China.,Collaborative Innovation Center for Brain Science, Shanghai, China.,Collaborative Innovation Center for Genetics and Development, Shanghai, China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Parkinson's Disease Center of Beijing Institute for Brain Disorders, Beijing, China.,Collaborative Innovation Center for Brain Science, Shanghai, China.,Collaborative Innovation Center for Genetics and Development, Shanghai, China.,Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
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5
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Burciu RG, Seidler RD, Shukla P, Nalls MA, Singleton AB, Okun MS, Vaillancourt DE. Multimodal neuroimaging and behavioral assessment of α-synuclein polymorphism rs356219 in older adults. Neurobiol Aging 2018; 66:32-39. [PMID: 29505953 DOI: 10.1016/j.neurobiolaging.2018.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/26/2018] [Accepted: 02/02/2018] [Indexed: 11/24/2022]
Abstract
The single-nucleotide polymorphism rs356219 in the α-synuclein (SNCA) gene has been shown to significantly contribute to an earlier age at onset of Parkinson's disease (PD), and regulates SNCA expression in PD brain regions, blood, and plasma. Here, we used multimodal magnetic resonance imaging (MRI) to study healthy adults with and without the rs356219 risk genotype. Motor and cognitive tests were administered, and all participants underwent functional and structural MRI. Imaging analyses included (1) task-based functional MRI; (2) task-based functional connectivity; (3) free-water diffusion MRI of the substantia nigra; (4) voxel-based morphometry; and (5) surface-based morphometry. There were no differences between the 2 groups in motor and cognitive performance, or brain structure. However, carrying a PD risk variant was associated with reduced functional activity in the posterior putamen and primary motor cortex. Moreover, the posterior putamen had reduced functional connectivity with the motor cortex during motor control in those with a risk genotype compared to those without. These findings point to functional abnormalities in the striatocortical circuit of rs356219 risk genotype carriers.
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Affiliation(s)
- Roxana G Burciu
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Priyank Shukla
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Mike A Nalls
- Data Tecnica International, Glen Echo, MD, USA; Laboratory of Neurogenetics, National Institute of Aging, Bethesda, MD, USA
| | | | - Michael S Okun
- Department of Neurology, University of Florida, Gainesville, FL, USA; Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, FL, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Neurology, University of Florida, Gainesville, FL, USA; Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
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SNCA rs356182 variant increases risk of sporadic Parkinson's disease in ethnic Chinese. J Neurol Sci 2016; 368:231-4. [PMID: 27538639 DOI: 10.1016/j.jns.2016.07.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 06/24/2016] [Accepted: 07/12/2016] [Indexed: 02/05/2023]
Abstract
PURPOSE A genome-wide association study (GWAS) has recently identified a novel single nucleotide polymorphism (SNP) rs356182 at SNCA that can modulate the risk of Parkinson's disease (PD) in Caucasian ancestry. The present study was designed to clarify the strength of the association in ethnic Chinese population. METHODS Using a case-control methodology, we genotyped the SNP rs356182 to investigate the association with risk of PD. A total of 2205 ethnic Han Chinese study subjects comprising 1053 sporadic PD patients (581 males, 472 females) and 1152 controls (604 males, 548 females) were recruited from Mainland China. Additionally, the SHEsis software platform was applied for linkage disequilibrium (LD) analysis between rs356182 and another PD-associated synuclein SNP rs356219 we previously reported. RESULTS The frequency of SNCA rs356182-G allele was significantly higher in PD group than that in controls (odds ratio (OR)=1.470, 95% confidence interval (CI): 1.284-1.683, P=2.306E-8). Subjects carrying GG/AG genotype had an increased risk compared with the AA carriers (OR=1.162, 95% CI: 1.143-2.274, P=0.006). Among all the genotypes of rs356182, GG genotype showed the strongest association with risk of PD (GG vs. AG/AA, OR=1.620, 95% CI: 1.368-1.919, P=2.001E-8). However, the gender, onset age, disease duration, Hoehn-Yahr stage, UPDRS scores and other clinical features were similar between GG genotype carriers and non-carriers. No LD between rs356182 and rs356219 was found in our population (r(2)=0.016 and D'=0.163). CONCLUSION Our study firstly demonstrates that SNCA rs356182 variant has an increased risk of susceptibility to PD in Han Chinese population. Further functional analysis is required to determine the role of this SNP in development of PD.
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Shi C, Zheng Z, Wang Q, Wang C, Zhang D, Zhang M, Chan P, Wang X. Exploring the Effects of Genetic Variants on Clinical Profiles of Parkinson's Disease Assessed by the Unified Parkinson's Disease Rating Scale and the Hoehn-Yahr Stage. PLoS One 2016; 11:e0155758. [PMID: 27299523 PMCID: PMC4907455 DOI: 10.1371/journal.pone.0155758] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 05/04/2016] [Indexed: 11/25/2022] Open
Abstract
Many genetic variants have been linked to familial or sporadic Parkinson’s disease (PD), among which those identified in PARK16, BST1, SNCA, LRRK2, GBA and MAPT genes have been demonstrated to be the most common risk factors worldwide. Moreover, complex gene-gene and gene-environment interactions have been highlighted in PD pathogenesis. Compared to studies focusing on the predisposing effects of genes, there is a relative lack of research investigating how these genes and their interactions influence the clinical profiles of PD. In a cohort consisting of 2,011 Chinese Han PD patients, we selected 9 representative variants from the 6 above-mentioned common PD genes to analyze their main and epistatic effects on the Unified Parkinson’s Disease Rating Scale (UPDRS) and the Hoehn and Yahr (H-Y) stage of PD. With multiple linear regression models adjusting for medication status, disease duration, gender and age at onset, none of the variants displayed significant main effects on UPDRS or the H-Y scores. However, for gene-gene interaction analyses, 7 out of 37 pairs of variants showed significant or marginally significant associations with these scores. Among these, the GBA rs421016 (L444P)×LRRK2 rs33949390 (R1628P) interaction was consistently significant in relation to UPDRS III and UPDRS total (I+II+III), even after controlling for the family-wise error rate using False Discovery Rate (FDR-corrected p values are 0.0481 and 0.0070, respectively). Although the effects of the remaining pairs of variants did not survive the FDR correction, they showed marginally significant associations with either UPDRS or the H-Y stage (raw p<0.05). Our results highlight the importance of epistatic effects of multiple genes on the determination of PD clinical profiles and may have implications for molecular classification and personalized intervention of the disease.
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Affiliation(s)
- Chen Shi
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
- Bioinformatics Center, School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Zheng Zheng
- Department of Neurobiology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Qi Wang
- Department of Statistics, Purdue University, West Lafayette, Indiana, United States of America
| | - Chaodong Wang
- Department of Neurobiology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China
- Department of Neurology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China
- Department of Neurology, The Affiliated Sanming First Hospital of Fujian Medical University, Sanming, Fujian, China
| | - Dabao Zhang
- Bioinformatics Center, School of Biomedical Engineering, Capital Medical University, Beijing, China
- Department of Statistics, Purdue University, West Lafayette, Indiana, United States of America
| | - Min Zhang
- Bioinformatics Center, School of Biomedical Engineering, Capital Medical University, Beijing, China
- Department of Statistics, Purdue University, West Lafayette, Indiana, United States of America
- Alzheimer Disease Center of Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
- * E-mail: (MZ); (PC); (XMW)
| | - Piu Chan
- Department of Neurobiology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China
- Department of Neurology, Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China
- Key Laboratory on Neurodegenerative Disease of Ministry of Education and Key Laboratory on Parkinson’s Disease of Beijing, Beijing, China
- Parkinson Disease Center of Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
- * E-mail: (MZ); (PC); (XMW)
| | - Xiaomin Wang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
- Parkinson Disease Center of Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
- * E-mail: (MZ); (PC); (XMW)
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8
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Benskey MJ, Perez RG, Manfredsson FP. The contribution of alpha synuclein to neuronal survival and function - Implications for Parkinson's disease. J Neurochem 2016; 137:331-59. [PMID: 26852372 PMCID: PMC5021132 DOI: 10.1111/jnc.13570] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 02/06/2023]
Abstract
The aggregation of alpha synuclein (α-syn) is a neuropathological feature that defines a spectrum of disorders collectively termed synucleinopathies, and of these, Parkinson's disease (PD) is arguably the best characterized. Aggregated α-syn is the primary component of Lewy bodies, the defining pathological feature of PD, while mutations or multiplications in the α-syn gene result in familial PD. The high correlation between α-syn burden and PD has led to the hypothesis that α-syn aggregation produces toxicity through a gain-of-function mechanism. However, α-syn has been implicated to function in a diverse range of essential cellular processes such as the regulation of neurotransmission and response to cellular stress. As such, an alternative hypothesis with equal explanatory power is that the aggregation of α-syn results in toxicity because of a toxic loss of necessary α-syn function, following sequestration of functional forms α-syn into insoluble protein aggregates. Within this review, we will provide an overview of the literature linking α-syn to PD and the knowledge gained from current α-syn-based animal models of PD. We will then interpret these data from the viewpoint of the α-syn loss-of-function hypothesis and provide a potential mechanistic model by which loss of α-syn function could result in at least some of the neurodegeneration observed in PD. By providing an alternative perspective on the etiopathogenesis of PD and synucleinopathies, this may reveal alternative avenues of research in order to identify potential novel therapeutic targets for disease modifying strategies. The correlation between α-synuclein burden and Parkinson's disease pathology has led to the hypothesis that α-synuclein aggregation produces toxicity through a gain-of-function mechanism. However, in this review, we discuss data supporting the alternative hypothesis that the aggregation of α-synuclein results in toxicity because of loss of necessary α-synuclein function at the presynaptic terminal, following sequestration of functional forms of α-synuclein into aggregates.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Ruth G Perez
- Department of Biomedical Sciences, Center of Emphasis in Neuroscience, Paul L. Foster School of Medicine, Texas Tech University of the Health Sciences El Paso, El Paso, Texas, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
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Yu WJ, Cheng L, Li NN, Wang L, Tan EK, Peng R. Interaction between SNCA, LRRK2 and GAK increases susceptibility to Parkinson's disease in a Chinese population. eNeurologicalSci 2015; 1:3-6. [PMID: 29479569 PMCID: PMC5852682 DOI: 10.1016/j.ensci.2015.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 02/05/2023] Open
Abstract
PD is a complex disease, and may result from gene–gene and gene–environment interactions. There are limited studies on gene–gene interactions in PD. We and others have previously shown that SNCA rs356219, LRRK2 (rs2046932 and rs7304279) and GAK (rs1564282) are risk factors in sporadic PD. Since the expression of SNCA and neurotoxicity of alpha-synuclein are affected by LRRK2 and GAK, we hypothesize that their genetic risk variants may interact with each other. Here we investigated the interaction of SNCA rs356219, LRRK2rs7304279 and rs2046932 and GAK rs1564282 using the Multifactor Dimensionality Reduction (MDR) in a Chinese PD patient–control series (534 patients and 435 controls) and the cumulative risk effect of SNCA, LRRK2 and GAK. The MDR analysis showed a significant gene–gene interaction between the rs356219 of SNCA, rs2046932 of LRRK2 and rs1564282 of GAK. Moreover, individuals with increasing numbers of variants had an increasing likelihood of having PD, compared with those carrying none of the variants. The estimated OR for developing PD in individuals carrying 3 variants was 5.89. We demonstrated for the first time that SNPs in SNCA, LRRK2 and GAK interacted with each other to confer an increased risk of PD. In addition, PD risk increased cumulatively with the increasing number of variants.
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Affiliation(s)
- Wen-Juan Yu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
| | - Lan Cheng
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
| | - Nan-Nan Li
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
| | - Ling Wang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
| | - Eng-King Tan
- Duke-NUS Graduate Medical School, Singapore, Singapore.,Department of Neurology, Singapore General Hospital, National Neuroscience Institute, Singapore, Singapore
| | - Rong Peng
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
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10
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Xu W, Tan L, Yu JT. Link between the SNCA gene and parkinsonism. Neurobiol Aging 2014; 36:1505-18. [PMID: 25554495 DOI: 10.1016/j.neurobiolaging.2014.10.042] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 10/30/2014] [Accepted: 10/31/2014] [Indexed: 12/11/2022]
Abstract
The groundbreaking discovery of mutations in the SNCA gene in a rare familial form of Parkinson's disease (PD) has revolutionized our basic understanding of the etiology of PD and other related disorders. Genome-wide Association Studies has demonstrated a wide array of single-nucleotide polymorphisms associated with the increasing risk of developing the more common type, sporadic PD, further corroborating the genetic etiology of PD. Among them, SNCA is a gene responsible for encoding α-synuclein, a protein found to be the major component of Lewy body and Lewy neurite, both of these components are the pathognomonic hallmarks of PD. Thus, it has been postulated that this gene plays specific roles in pathogenesis of PD. Here, we summarize the basic biological characteristics of the wild type of the protein (wt-α-synuclein) as well as genetic and epigenetic features of its encoding gene (SNCA) in PD. Based on these characteristics, SNCA may be involved in PD pathogenesis in at least 2 ways: wt-α-synuclein overexpression and its mutation types via different mechanisms. Associations between SNCA mutations and other Lewy body disorders, such as dementia with Lewy bodies and multiple system atrophy, are also mentioned. Finally, it is necessary to explore the influences which SNCA exerts on clinical and neuropathological phenotypes by promoting the transfer of scientific research into practice, such as clinical evaluation, diagnosis, and treatment of the disease. We believe it is promising to target SNCA for developing novel therapeutic strategies for parkinsonism.
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Affiliation(s)
- Wei Xu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong Province, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong Province, China; Department of Neurology, Qingdao Municipal Hospital, College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, Shandong Province, China; Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China.
| | - Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong Province, China; Department of Neurology, Qingdao Municipal Hospital, College of Medicine and Pharmaceutics, Ocean University of China, Qingdao, Shandong Province, China; Department of Neurology, Qingdao Municipal Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China.
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