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Sun Z, Kantor B, Chiba-Falek O. Neuronal-type-specific epigenome editing to decrease SNCA expression: Implications for precision medicine in synucleinopathies. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102084. [PMID: 38130373 PMCID: PMC10732167 DOI: 10.1016/j.omtn.2023.102084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
Overexpression of SNCA has been implicated in the pathogenesis of synucleinopathies, particularly Parkinson's disease (PD) and dementia with Lewy bodies (DLB). While PD and DLB share some clinical and pathological similarities, each disease presents distinct characteristics, including the primary affected brain region and neuronal type. We aimed to develop neuronal-type-specific SNCA-targeted epigenome therapies for synucleinopathies. The system is based on an all-in-one lentiviral vector comprised of CRISPR-dSaCas9 and guide RNA (gRNA) targeted at SNCA intron 1 fused with a synthetic repressor molecule of Krüppel-associated box (KRAB)/ methyl CpG binding protein 2 (MeCp2) transcription repression domain (TRD). To achieve neuronal-type specificity for dopaminergic and cholinergic neurons, the system was driven by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) promoters, respectively. Delivering the system into human induced pluripotent stem cell (hiPSC)-derived dopaminergic and cholinergic neurons from a patient with the SNCA triplication resulted in efficient and neuronal-type-specific downregulation of SNCA-mRNA and protein. Furthermore, the reduction in SNCA levels by the gRNA-dSaCas9-repressor system rescued disease-related cellular phenotypes including Ser129-phophorylated α-synuclein, neuronal viability, and mitochondrial dysfunction. We established a novel neuronal-type-specific SNCA-targeted epigenome therapy and provided in vitro proof of concept using human-based disease models. Our results support the therapeutic potential of our system for PD and DLB and provide the foundation for further preclinical studies in animal models toward investigational new drug (IND) enablement and clinical trials.
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Affiliation(s)
| | - Boris Kantor
- Viral Vector Core, Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
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2
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Frydas A, Wauters E, van der Zee J, Van Broeckhoven C. Uncovering the impact of noncoding variants in neurodegenerative brain diseases. Trends Genet 2021; 38:258-272. [PMID: 34535299 DOI: 10.1016/j.tig.2021.08.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022]
Abstract
Neurodegenerative brain diseases (NBDs) are characterized by cognitive decline and movement impairments caused by neuronal loss in different brain regions. A large fraction of the genetic heritability of NBDs is not explained by the current known mutations. Genome-wide association studies identified novel disease-risk loci, adding to the genetic basis of NBDs. Many of the associated variants reside in noncoding regions with distinct molecular functions. Genetic variation in these regions can alter functions and contribute to disease pathogenesis. Here, we discuss noncoding variants associated with NBDs. Methods for better functional interpretation of noncoding variation will expand our knowledge of the genetic architecture of NBDs and broaden the routes for therapeutic strategies.
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Affiliation(s)
- Alexandros Frydas
- Neurodegenerative Brain Diseases, Center for Molecular Neurology, VIB, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Eline Wauters
- Neurodegenerative Brain Diseases, Center for Molecular Neurology, VIB, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Julie van der Zee
- Neurodegenerative Brain Diseases, Center for Molecular Neurology, VIB, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases, Center for Molecular Neurology, VIB, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
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Gu J, Barrera J, Yun Y, Murphy SK, Beach TG, Woltjer RL, Serrano GE, Kantor B, Chiba-Falek O. Cell-Type Specific Changes in DNA Methylation of SNCA Intron 1 in Synucleinopathy Brains. Front Neurosci 2021; 15:652226. [PMID: 33994928 PMCID: PMC8113398 DOI: 10.3389/fnins.2021.652226] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/06/2021] [Indexed: 11/26/2022] Open
Abstract
Parkinson's disease (PD) and dementia with Lewy body (DLB) are the most common synucleinopathies. SNCA gene is a major genetic risk factor for these diseases group, and dysregulation of its expression has been implicated in the genetic etiologies of several synucleinopathies. DNA methylation at CpG island (CGI) within SNCA intron 1 has been suggested as a regulatory mechanism of SNCA expression, and changes in methylation levels at this region were associated with PD and DLB. However, the role of DNA methylation in the regulation of SNCA expression in a cell-type specific manner and its contribution to the pathogenesis of PD and DLB remain poorly understood, and the data are conflicting. Here, we employed a bisulfite pyrosequencing technique to profile the DNA methylation across SNCA intron 1 CGI in PD and DLB compared to age- and sex-matched normal control subjects. We analyzed homogenates of bulk post-mortem frozen frontal cortex samples and a subset of neuronal and glia nuclei sorted by the fluorescence-activated nuclei sorting (FANS) method. Bulk brain tissues showed no significant difference in the overall DNA methylation across SNCA intron 1 CGI region between the neuropathological groups. Sorted neuronal nuclei from PD frontal cortex showed significant lower levels of DNA methylation at this region compared to normal controls, but no differences between DLB and control, while sorted glia nuclei exhibited trends of decreased overall DNA methylation in DLB only. In conclusion, our data suggested disease-dependent cell-type specific differential DNA methylation within SNCA intron 1 CGI. These changes may affect SNCA dysregulation that presumably mediates disease-specific risk. Our results can be translated into the development of the SNCA intron 1 CGI region as an attractive therapeutics target for gene therapy in patients who suffer from synucleinopathies due to SNCA dysregulation.
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Affiliation(s)
- Jeffrey Gu
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, United States
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, United States
| | - Julio Barrera
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, United States
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, United States
| | - Young Yun
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, United States
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, United States
| | - Susan K. Murphy
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC, United States
| | - Thomas G. Beach
- Banner Sun Health Research Institute, Sun City, AZ, United States
| | - Randy L. Woltjer
- Layton Aging and Alzheimer’s Disease Center, Department of Pathology, Oregon Health & Science University, Portland, OR, United States
| | - Geidy E. Serrano
- Banner Sun Health Research Institute, Sun City, AZ, United States
| | - Boris Kantor
- Viral Vector Core, Duke University Medical Center, Durham, NC, United States
- Department of Neurobiology, Duke University Medical Center, Durham, NC, United States
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, United States
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, United States
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4
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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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5
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SNCA variants and alpha-synuclein level in CD45+ blood cells in Parkinson’s disease. J Neurol Sci 2018; 395:135-140. [DOI: 10.1016/j.jns.2018.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 08/30/2018] [Accepted: 10/02/2018] [Indexed: 11/23/2022]
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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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Obergasteiger J, Frapporti G, Pramstaller PP, Hicks AA, Volta M. A new hypothesis for Parkinson's disease pathogenesis: GTPase-p38 MAPK signaling and autophagy as convergence points of etiology and genomics. Mol Neurodegener 2018; 13:40. [PMID: 30071902 PMCID: PMC6090926 DOI: 10.1186/s13024-018-0273-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 07/19/2018] [Indexed: 02/07/2023] Open
Abstract
The combination of genetics and genomics in Parkinson´s disease has recently begun to unveil molecular mechanisms possibly underlying disease onset and progression. In particular, catabolic processes such as autophagy have been increasingly gaining relevance as post-mortem evidence and experimental models suggested a participation in neurodegeneration and alpha-synuclein Lewy body pathology. In addition, familial Parkinson´s disease linked to LRRK2 and alpha-synuclein provided stronger correlation between etiology and alterations in autophagy. More detailed cellular pathways are proposed and genetic risk factors that associate with idiopathic Parkinson´s disease provide further clues in dissecting contributions of single players. Nevertheless, the fine-tuning of these processes remains elusive, as the initial stages of the pathways are not yet clarified.In this review, we collect literature evidence pointing to autophagy as the common, downstream target of Parkinsonian dysfunctions and augment current knowledge on the factors that direct the subsequent steps. Cell and molecular biology evidence indicate that p38 signaling underlies neurodegeneration and autoptic observations suggest a participation in neuropathology. Moreover, alpha-synuclein and LRRK2 also appear involved in the p38 pathway with additional roles in the regulation of GTPase signaling. Small GTPases are critical modulators of p38 activation and thus, their functional interaction with aSyn and LRRK2 could explain much of the detailed mechanics of autophagy in Parkinson´s disease.We propose a novel hypothesis for a more comprehensive working model where autophagy is controlled by upstream pathways, such as GTPase-p38, that have been so far underexplored in this context. In addition, etiological factors (LRRK2, alpha-synuclein) and risk loci might also combine in this common mechanism, providing a powerful experimental setting to dissect the cause of both familial and idiopathic disease.
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Affiliation(s)
- Julia Obergasteiger
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Giulia Frapporti
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
- Department of Neurology, General Central Hospital, Via Böhler 5, 39100 Bolzano, Italy
- Department of Neurology, University of Lübeck, Ratzeburger Allee, 23538 Lübeck, Germany
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
| | - Mattia Volta
- Institute for Biomedicine, Eurac Research – Affiliated Institute of the University of Lübeck, Via Galvani 31, 39100 Bolzano, Italy
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Shu L, Zhang Y, Sun Q, Pan H, Guo J, Tang B. SNCA REP1 and Parkinson's disease. Neurosci Lett 2018; 682:79-84. [PMID: 29859327 DOI: 10.1016/j.neulet.2018.05.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 10/01/2022]
Abstract
REP1 is a polymorphic dinucleotide repeat sequence located in the promoter region of the SNCA gene (OMIM 163890). Opinions regarding the interaction between the various REP1 alleles and Parkinson's disease (PD) or its phenotypes have been inconsistent and have thus far not been comprehensively analyzed. In this study, we searched Medline, Embase and Cochrane databases as well as the Chinese-language Wanfang and CNKI databases using strict inclusion and exclusion criteria and conducted our analysis using Revman 5.3 software. Our search produced 28 articles describing REP1 alleles and their associated PD risks and 8 articles which discussed the relationship between REP1 variation and PD phenotypes. We found that the 265-, 269-, and 271-bp alleles of REP1 (using the nomenclature established by Xia et al.) increased the risk of PD (OR: 1.81, 1.05, 1.17; p: 0.0002, 0.003, 0.002) while the 267-bp allele decreased PD risk (OR: 0.86, p: <0.00001) when taking all populations into account. By ethnicity, we observed an obvious population heterogeneity in the effects of various alleles, where the 269-, 271-, and 273-bp alleles increased PD risk (OR: 1.06, 1.22, 1.89; p: 0.001, 0.003, 0.001) and the 267-bp allele decreased PD risk (OR: 0.85; p: <0.00001) in Caucasian populations, and the 263- and 265-bp alleles increased the risk of PD (OR: 2.22, 2.03; p: 0.03, 0.0002) and the 267- and 273-bp alleles decreased PD risk (OR: 0.90, 0.78; p: 0.02, 0.03) in Asian populations. We also determined that the 267-, 269-, and 271-bp alleles occurred the most frequently, although the frequency distribution varied among different ethnicities. Phenotypic analysis demonstrated that PD patients carrying the 271-bp allele were prone to early onset PD (OR: 1.75, p: 0.02) while the 267-bp had the opposite effect (OR: 0.81; p: 0.01).
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Affiliation(s)
- Li Shu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Yuan Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Qiying Sun
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Changsha, Hunan 410078, China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan 410008, China
| | - Hongxu Pan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Changsha, Hunan 410078, China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan 410008, China; Parkinson's Disease Center of Beijing Institute for Brain Disorders, Beijing 100069, China; Collaborative Innovation Center for Brain Science, Shanghai 200032, China; Collaborative Innovation Center for Genetics and Development, Shanghai 200438, China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Changsha, Hunan 410078, China; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, Hunan 410008, China; Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410008, China; Parkinson's Disease Center of Beijing Institute for Brain Disorders, Beijing 100069, China; Collaborative Innovation Center for Brain Science, Shanghai 200032, China; Collaborative Innovation Center for Genetics and Development, Shanghai 200438, China.
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Barrie ES, Lee S, Frater JT, Kataki M, Scharre DW, Sadee W. Alpha-synuclein mRNA isoform formation and translation affected by polymorphism in the human SNCA 3'UTR. Mol Genet Genomic Med 2018; 6:565-574. [PMID: 29730891 PMCID: PMC6081226 DOI: 10.1002/mgg3.407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/02/2018] [Accepted: 04/05/2018] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Multiple variants in SNCA, encoding alpha-synuclein, a main component of Lewy bodies, are implicated in Parkinson's disease. METHODS We searched for cis-acting SNCA variants using allelic mRNA ratios in human brain tissues. In a SNCA 3'UTR (2,520 bp) luciferase reporter gene assay, translation in SH-SY5Y cells in the presence of the rs17016074 G/A alleles was measured. To assess clinical impact, we queried neurocognitive genome-wide association studies. RESULTS Allelic ratios deviated up to twofold, measured at a marker SNP in the middle of a long 3' untranslated region (3'UTR), but not at a marker at its start, suggesting regulation of 3'UTR processing. 3'UTR SNP rs17016074 G/A, minor allele frequency (MAF) <1% in Caucasians, 13% in Africans, strongly associates with large allelic mRNA expression imbalance (AEI), resulting in reduced expression of long 3'UTR isoforms. A second 3'UTR SNP (rs356165) associates with moderate AEI and enhances SNCA mRNA expression. The rs17016074 A allele reduces overall 3'UTR expression in luciferase reporter gene assays but supports more efficient translation, resolving previous contradictory results. We failed to detect significant genome-wide associations for rs17016074, possibly a result of low MAF in Caucasians or its absence from most genotyping panels. In the "Genome Wide Association Study of Yoruba in Nigeria," rs356165 was associated with reduced memory performance. CONCLUSIONS Here, we identify two cis-acting regulatory variants affecting SNCA mRNA expression, measured by allelic ratios in the 3'UTR. The rs17016074 minor A allele is associated with higher expression of luciferase protein activity. Resolving the genetic influence of SNCA polymorphisms requires study of the interactions between multiple regulatory variants with distinct frequencies among populations.
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Affiliation(s)
- Elizabeth S. Barrie
- Institute for Genomic MedicineNationwide Children's HospitalColumbusOhio
- Center for PharmacogenomicsDepartment of Cancer Biology and GeneticsCollege of MedicineThe Ohio State UniversityColumbusOhio
| | - Sung‐Ha Lee
- Center for PharmacogenomicsDepartment of Cancer Biology and GeneticsCollege of MedicineThe Ohio State UniversityColumbusOhio
| | - John T. Frater
- Center for PharmacogenomicsDepartment of Cancer Biology and GeneticsCollege of MedicineThe Ohio State UniversityColumbusOhio
| | - Maria Kataki
- Division of Cognitive NeurologyDepartment of NeurologyThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Douglas W. Scharre
- Division of Cognitive NeurologyDepartment of NeurologyThe Ohio State University Wexner Medical CenterColumbusOhio
| | - Wolfgang Sadee
- Center for PharmacogenomicsDepartment of Cancer Biology and GeneticsCollege of MedicineThe Ohio State UniversityColumbusOhio
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Su L, Wang C, Zheng C, Wei H, Song X. A meta-analysis of public microarray data identifies biological regulatory networks in Parkinson's disease. BMC Med Genomics 2018; 11:40. [PMID: 29653596 PMCID: PMC5899355 DOI: 10.1186/s12920-018-0357-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parkinson's disease (PD) is a long-term degenerative disease that is caused by environmental and genetic factors. The networks of genes and their regulators that control the progression and development of PD require further elucidation. METHODS We examine common differentially expressed genes (DEGs) from several PD blood and substantia nigra (SN) microarray datasets by meta-analysis. Further we screen the PD-specific genes from common DEGs using GCBI. Next, we used a series of bioinformatics software to analyze the miRNAs, lncRNAs and SNPs associated with the common PD-specific genes, and then identify the mTF-miRNA-gene-gTF network. RESULT Our results identified 36 common DEGs in PD blood studies and 17 common DEGs in PD SN studies, and five of the genes were previously known to be associated with PD. Further study of the regulatory miRNAs associated with the common PD-specific genes revealed 14 PD-specific miRNAs in our study. Analysis of the mTF-miRNA-gene-gTF network about PD-specific genes revealed two feed-forward loops: one involving the SPRK2 gene, hsa-miR-19a-3p and SPI1, and the second involving the SPRK2 gene, hsa-miR-17-3p and SPI. The long non-coding RNA (lncRNA)-mediated regulatory network identified lncRNAs associated with PD-specific genes and PD-specific miRNAs. Moreover, single nucleotide polymorphism (SNP) analysis of the PD-specific genes identified two significant SNPs, and SNP analysis of the neurodegenerative disease-specific genes identified seven significant SNPs. Most of these SNPs are present in the 3'-untranslated region of genes and are controlled by several miRNAs. CONCLUSION Our study identified a total of 53 common DEGs in PD patients compared with healthy controls in blood and brain datasets and five of these genes were previously linked with PD. Regulatory network analysis identified PD-specific miRNAs, associated long non-coding RNA and feed-forward loops, which contribute to our understanding of the mechanisms underlying PD. The SNPs identified in our study can determine whether a genetic variant is associated with PD. Overall, these findings will help guide our study of the complex molecular mechanism of PD.
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Affiliation(s)
- Lining Su
- Department of Biology of Basic Medical Science College, Hebei North University, Zhangjiakou, 075000, Hebei, China
| | - Chunjie Wang
- Department of Basic Medicine, Zhangjiakou University, Zhangjiakou, 75000, Hebei, China
| | - Chenqing Zheng
- Shenzhen RealOmics (Biotech) Co., Ltd, Shenzhen, 518081, Guangdong, China
| | - Huiping Wei
- Department of Biology of Basic Medical Science College, Hebei North University, Zhangjiakou, 075000, Hebei, China.
| | - Xiaoqing Song
- Department of Biology of Basic Medical Science College, Hebei North University, Zhangjiakou, 075000, Hebei, China
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Glenn OC, Tagliafierro L, Beach TG, Woltjer RL, Chiba-Falek O. Interpreting Gene Expression Effects of Disease-Associated Variants: A Lesson from SNCA rs356168. Front Genet 2017; 8:133. [PMID: 28979294 PMCID: PMC5611418 DOI: 10.3389/fgene.2017.00133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/07/2017] [Indexed: 11/13/2022] Open
Abstract
The SNCA intronic single nucleotide polymorphism (SNP), rs356168, has been associated with Parkinson's disease (PD) in large genome wide association studies (GWAS). Recently, the PD-risk allele, rs356168-G was shown to increase SNCA-mRNA expression using genome edited human induced pluripotent stem cells (iPSC)-derived neurons. In this study, as means of validation, we tested the effect of rs356168 on total SNCA-mRNA levels using brain tissues, temporal and frontal cortex, from healthy control donors. Carriers of the rs356168-G allele demonstrated a borderline significant decrease of SNCA-mRNA levels in temporal brain tissues (p = 0.02) compared to individuals homozygous for the 'A' allele. Similar trend, but weak, was observed in the analysis of frontal cortex samples, however, this analysis did not reach statistical significance. These results conflict with the recently reported effect of SNCA SNP rs356168 described above. Our study conveys the need to carefully interpret the precise molecular mechanism by which rs356168, or another tightly linked variant, affects the regulation of SNCA expression. The regulatory mechanisms that contribute to the observed associations between PD and the SNCA-3' linkage disequilibrium region warrant further investigations.
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Affiliation(s)
- Omolara-Chinue Glenn
- Department of Neurology, Duke University Medical Center, DurhamNC, United States.,Center for Genomic and Computational Biology, Duke University Medical Center, DurhamNC, United States
| | - Lidia Tagliafierro
- Department of Neurology, Duke University Medical Center, DurhamNC, United States.,Center for Genomic and Computational Biology, Duke University Medical Center, DurhamNC, United States
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun CityAZ, United States
| | - Randy L Woltjer
- Layton Aging and Alzheimer's Disease Center, Department of Pathology, Oregon Health and Science University, PortlandOR, United States
| | - Ornit Chiba-Falek
- Department of Neurology, Duke University Medical Center, DurhamNC, United States.,Center for Genomic and Computational Biology, Duke University Medical Center, DurhamNC, United States
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Genetic Variants in SNCA and the Risk of Sporadic Parkinson's Disease and Clinical Outcomes: A Review. PARKINSONS DISEASE 2017; 2017:4318416. [PMID: 28781905 PMCID: PMC5525082 DOI: 10.1155/2017/4318416] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/17/2017] [Accepted: 05/24/2017] [Indexed: 12/14/2022]
Abstract
There is increasing evidence of the contribution of genetic susceptibility to the etiology of Parkinson's disease (PD). Genetic variations in the SNCA gene are well established by linkage and genome-wide association studies. Positive associations of single nucleotide polymorphisms (SNPs) in SNCA and increased risk for PD were found. However, the role of SNCA variants in individual traits or phenotypes of PD is unknown. Here, we reviewed the current literature and identified 57 studies, performed in fourteen different countries, that investigated SNCA variants and susceptibility to PD. We discussed the findings based on environmental factors, history of PD, clinical outcomes, and ethnicity. In conclusion, SNPs within the SNCA gene can modify the susceptibility to PD, leading to increased or decreased risk. The risk associations of some SNPs varied among samples. Of notice, no studies in South American or African populations were found. There is little information about the effects of these variants on particular clinical aspects of PD, such as motor and nonmotor symptoms. Similarly, evidence of possible interactions between SNCA SNPs and environmental factors or disease progression is scarce. There is a need to expand the clinical applicability of these data as well as to investigate the role of SNCA SNPs in populations with different ethnic backgrounds.
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Campêlo CLC, Cagni FC, de Siqueira Figueredo D, Oliveira LG, Silva-Neto AB, Macêdo PT, Santos JR, Izídio GS, Ribeiro AM, de Andrade TG, de Oliveira Godeiro C, Silva RH. Variants in SNCA Gene Are Associated with Parkinson's Disease Risk and Cognitive Symptoms in a Brazilian Sample. Front Aging Neurosci 2017; 9:198. [PMID: 28676755 PMCID: PMC5476777 DOI: 10.3389/fnagi.2017.00198] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 06/02/2017] [Indexed: 02/06/2023] Open
Abstract
Genetic susceptibility contributes to the etiology of sporadic Parkinson's Disease (PD) and worldwide studies have found positive associations of polymorphisms in the alpha-synuclein gene (SNCA) with the risk for PD. However, little is known about the influence of variants of SNCA in individual traits or phenotypical aspects of PD. Further, there is a lack of studies with Latin-American samples. We evaluated the association between SNCA single nucleotide polymorphisms (single nucleotide polymorphisms, SNPs - rs2583988, rs356219, rs2736990, and rs11931074) and PD risk in a Brazilians sample. In addition, we investigated their potential interactions with environmental factors and specific clinical outcomes (motor and cognitive impairments, depression, and anxiety). A total of 105 PD patients and 101 controls participated in the study. Single locus analysis showed that the risk allele of all SNPs were more frequent in PD patients (p < 0.05), and the associations of SNPs rs2583988, rs356219, and rs2736990 with increased PD risk were confirmed. Further, the G-rs356219 and C-rs2736990 alleles were associated with early onset PD. T-rs2583988, G-rs356219 and C-2736990 alleles were significantly more frequent in PD patients with cognitive impairments than controls in this condition. In addition, in a logistic regression model, we found an association of cognitive impairment with PD, and the practice of cognitive activity and smoking habits had a protective effect. This study shows for the first time an association of SNCA polymorphism and PD in a South-American sample. In addition, we found an interaction between SNP rs356219 and a specific clinical outcome, i.e., the increased risk for cognitive impairment in PD patients.
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Affiliation(s)
- Clarissa L C Campêlo
- Memory Studies Laboratory, Physiology Department, Universidade Federal do Rio Grande do NorteNatal, Brazil
| | - Fernanda C Cagni
- Memory Studies Laboratory, Physiology Department, Universidade Federal do Rio Grande do NorteNatal, Brazil
| | | | - Luiz G Oliveira
- Medicine Department, Universidade Federal do Rio Grande do NorteNatal, Brazil
| | | | - Priscila T Macêdo
- Memory Studies Laboratory, Physiology Department, Universidade Federal do Rio Grande do NorteNatal, Brazil
| | - José R Santos
- Bioscience Department, Universidade Federal de SergipeItabaiana, Brazil
| | - Geison S Izídio
- Department of Cell Biology, Embryology and Genetics, Universidade Federal de Santa CatarinaFlorianópolis, Brazil
| | | | - Tiago G de Andrade
- Molecular Biology and Gene Expression Laboratory, Universidade Federal de AlagoasArapiraca, Brazil.,Faculty of Medicine, Universidade Federal de AlagoasMaceió, Brazil
| | | | - Regina H Silva
- Behavioral Neuroscience Laboratory, Pharmacology Department, Universidade Federal de São PauloSão Paulo, Brazil
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Toffoli M, Dreussi E, Cecchin E, Valente M, Sanvilli N, Montico M, Gagno S, Garziera M, Polano M, Savarese M, Calandra-Buonaura G, Placidi F, Terzaghi M, Toffoli G, Gigli GL. SNCA 3′UTR genetic variants in patients with Parkinson’s disease and REM sleep behavior disorder. Neurol Sci 2017; 38:1233-1240. [DOI: 10.1007/s10072-017-2945-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 04/01/2017] [Indexed: 11/28/2022]
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15
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Structural variants in SNCA gene and the implication to synucleinopathies. Curr Opin Genet Dev 2017; 44:110-116. [PMID: 28319736 DOI: 10.1016/j.gde.2017.01.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/30/2017] [Indexed: 01/23/2023]
Abstract
Synucleinopathies are a group of neurodegenerative diseases that share a common pathological lesion of intracellular protein inclusions largely composed of aggregates of alpha-synuclein protein. Accumulating evidence, including genome-wide association studies, has implicated the alpha-synuclein (SNCA) gene in the etiology of synucleinopathies and it has been suggested that SNCA expression levels are critical for the development of these diseases. This review focuses on genetic variants from the class of structural variants (SVs), including multiplication of large genomic segments and short (<50bp) genomic variants such as simple sequence repeats (SSRs), within the SNCA locus. We provide evidence that SNCA-SVs play a key role in the pathogenesis of synucleinopathies via their effects on gene expression and on regulatory mechanisms including transcription and splicing.
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Analysis of LRRK2, SNCA, and ITGA8 Gene Variants with Sporadic Parkinson's Disease Susceptibility in Chinese Han Population. PARKINSONS DISEASE 2016; 2016:3474751. [PMID: 27668119 PMCID: PMC5030423 DOI: 10.1155/2016/3474751] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 07/01/2016] [Accepted: 08/08/2016] [Indexed: 11/17/2022]
Abstract
Background. Parkinson's disease (PD) is an age-related neurodegenerative disease affected by multiple genetic and environmental factors. We performed a case-control study on candidate gene to scrutinize whether genetic variants in LRRK2, SNCA, and ITGA8 genes could be associated with sporadic PD in Chinese Han population. Methods. Five single-nucleotide polymorphisms (SNPs) of LRRK2 (rs1491942), SNCA (rs2301134, rs2301135, and rs356221), and ITGA8 (rs7077361) were selected and genotyped among 583 unrelated PD patients and 558 healthy controls. Results. Rs1491942 of LRRK2 gene had a significantly higher genotype frequency (P = 3.543E − 09) and allelic G/C frequencies (P = 2.601E − 10) in PD patients than controls. Rs2301135 of SNCA gene also showed an obvious difference in genotype frequency (P = 4.394E − 07) and allelic G/C frequencies (P = 9.116E − 13) between PD patients and controls. SNPs rs2301134 and rs356221 of SNCA gene and rs7077361 of ITGA8 gene lacked the significant association with the susceptibility of PD in Chinese Han population. Conclusions. Our study firstly expresses that rs1491942 of LRRK2 and rs2301135 of SNCA gene are substantially associated with sporadic Parkinson's disease in Chinese Han population.
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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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Tagliafierro L, Chiba-Falek O. Up-regulation of SNCA gene expression: implications to synucleinopathies. Neurogenetics 2016; 17:145-57. [PMID: 26948950 DOI: 10.1007/s10048-016-0478-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/27/2016] [Indexed: 01/06/2023]
Abstract
Synucleinopathies are a group of neurodegenerative diseases that share a common pathological lesion of intracellular protein inclusions largely composed by aggregates of alpha-synuclein protein. Accumulating evidence, including genome wide association studies, has implicated alpha-synuclein (SNCA) gene in the etiology of synucleinopathies. However, the precise variants within SNCA gene that contribute to the sporadic forms of Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and other synucleinopathies and their molecular mechanisms of action remain elusive. It has been suggested that SNCA expression levels are critical for the development of these diseases. Here, we review several model systems that have been developed to advance the understanding of the role of SNCA expression levels in the etiology of synucleinopathies. We also describe different molecular mechanisms that regulate SNCA gene expression and discuss possible strategies for SNCA down-regulation as means for therapeutic approaches. Finally, we highlight some examples that underscore the relationships between the genetic association findings and the regulatory mechanisms of SNCA expression, which suggest that genetic variability in SNCA locus is directly responsible, at least in part, to the changes in gene expression and explain the reported associations of SNCA with synucleinopathies. Future studies utilizing induced pluripotent stem cells (iPSCs)-derived neuronal lines and genome editing by CRISPR/Cas9, will allow us to validate, characterize, and manipulate the effects of particular cis-genetic variants on SNCA expression. Moreover, this model system will enable us to compare different neuronal and glial lineages involved in synucleinopathies representing an attractive strategy to elucidate-common and specific-SNCA-genetic variants, regulatory mechanisms, and vulnerable expression levels underlying synucleinopathy spectrum disorders. This forthcoming knowledge will support the development of precision medicine for synucleinopathies.
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Affiliation(s)
- L Tagliafierro
- Department of Neurology, Duke University Medical Center, Durham, NC, 27710, USA
| | - O Chiba-Falek
- Department of Neurology, Duke University Medical Center, Durham, NC, 27710, USA.
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The Potential Mutation of GAK Gene in the Typical Sporadic Parkinson's Disease from the Han Population of Chinese Mainland. Mol Neurobiol 2015; 53:7119-7136. [PMID: 26676575 DOI: 10.1007/s12035-015-9595-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 12/01/2015] [Indexed: 12/14/2022]
Abstract
The genetic factors about the pathogenesis of sporadic Parkinson's disease (sPD) is not completely clear at present; therefore, we performed a genome-wide association study, high-throughput sequencing analysis (HTPSA) of all cyclin G-associated kinase (GAK) exons, loss-of-function assessment, and sorting intolerant from tolerant analysis of HTPSA data in 250 typical sPD and 250 controls, which found 55 candidate single nucleotide polymorphisms (SNPs). To further explore these SNPs, we sequenced the 30 most strongly associated SNPs in the 460 typical sPD cases and the 525 controls. All subjects were from the Han population of Chinese mainland and excluded the toxic exposure, the heavy coffee drinking, and the early- and late-onset sPD. The minor allele frequencies (MAFs) at c.3824T>G, c.3794T>C, and c.3819G>A were higher in the control. The TG of c.3824T>G, the TC of c.3794T>C, and the AG of c.3819G>A were associated with the decreased risk of sPD. The subjects carrying the minor C allele of c.3794T>C or the minor A allele of c.3819G>A exhibited a decreased risk of sPD. c.3824T>G negatively affected the binding affinity of heat shock protein 70 (HSP70). c.3794T>C increased the surface area exposed to substrates. c.3819G>A most likely reduced the expression level of GAK. Our data suggest that the multiple SNPs of GAK synergistically participate in the pathogenesis of sPD through multiple pathways.
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20
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A cytosine-thymine (CT)-rich haplotype in intron 4 of SNCA confers risk for Lewy body pathology in Alzheimer's disease and affects SNCA expression. Alzheimers Dement 2015; 11:1133-43. [PMID: 26079410 DOI: 10.1016/j.jalz.2015.05.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 03/30/2015] [Accepted: 05/09/2015] [Indexed: 01/07/2023]
Abstract
INTRODUCTION We recently showed that tagging single-nucleotide polymorphisms across the SNCA locus were significantly associated with increased risk for Lewy body (LB) pathology in Alzheimer's disease (AD) cases. However, the actual genetic variant(s) that underlie the observed associations remain elusive. METHODS We used a bioinformatics algorithm to catalog structural variants in a region of SNCA intron 4, followed by phased sequencing. We performed a genetic association analysis in autopsy series of LB variant of Alzheimer's disease (LBV/AD) cases compared with AD-only controls. We investigated the biological functions by expression analysis using temporal-cortex samples. RESULTS We identified four distinct haplotypes within a highly polymorphic low-complexity cytosine-thymine (CT)-rich region. We showed that a specific haplotype conferred risk to develop LBV/AD. We demonstrated that the CT-rich site acts as an enhancer element, where the risk haplotype was significantly associated with elevated levels of SNCA messenger RNA. DISCUSSION We have discovered a novel haplotype in a CT-rich region in SNCA that contributes to LB pathology in AD patients, possibly via cis-regulation of the gene expression.
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Han W, Liu Y, Mi Y, Zhao J, Liu D, Tian Q. Alpha-synuclein (SNCA) polymorphisms and susceptibility to Parkinson's disease: a meta-analysis. Am J Med Genet B Neuropsychiatr Genet 2015; 168B:123-34. [PMID: 25656566 DOI: 10.1002/ajmg.b.32288] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 11/25/2014] [Indexed: 02/04/2023]
Abstract
It has been reported that single nucleotide polymorphisms (SNPs) of Alpha-synuclein (SNCA) are associated with Parkinson's disease (PD). Some researchers have attempted to validate this finding in various ethnic populations. The results of studies concerning SNCA polymorphisms and PD susceptibility remain conflicting. To evaluate the association between these SNPs and PD, the authors conducted a series of meta-analyses using a predefined protocol. Databases including PubMed, MEDLINE and PD gene were searched to identify relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. All analyses were calculated using STATA11.0. A total of 19 studies on the SNPS rs181489, rs356186, rs356219, rs894278, rs2583988, rs2619363, rs2619364, rs2737029, rs10005233 and rs11931074 were included. This meta-analysis showed that eight out of these 10 candidate SNPs may be associated with PD risk. Significant association was found between PD and the following SNPs: rs181489, rs356186, rs356219, rs894278 rs2583988, rs2619364, rs10005233 and rs11931074. Among these SNPs, rs356186 was found to be the only SNP that may play a protective role in Parkinson's disease. These results suggest that the SNCA gene may be associated with PD.
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Affiliation(s)
- Wei Han
- Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang, 050017, China
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22
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Verstraeten A, Theuns J, Van Broeckhoven C. Progress in unraveling the genetic etiology of Parkinson disease in a genomic era. Trends Genet 2015; 31:140-9. [PMID: 25703649 DOI: 10.1016/j.tig.2015.01.004] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 01/21/2015] [Accepted: 01/22/2015] [Indexed: 01/30/2023]
Abstract
Parkinson disease (PD) and Parkinson-plus syndromes are genetically heterogeneous neurological diseases. Initial studies into the genetic causes of PD relied on classical molecular genetic approaches in well-documented case families. More recently, these approaches have been combined with exome sequencing and together have identified 15 causal genes. Additionally, genome-wide association studies (GWASs) have discovered over 25 genetic risk factors. Elucidation of the genetic architecture of sporadic and familial parkinsonism, however, has lagged behind that of simple Mendelian conditions, suggesting the existence of features confounding genetic data interpretation. Here we discuss the successes and potential pitfalls of gene discovery in PD and related disorders in the post-genomic era. With an estimated 30% of trait variance currently unexplained, tackling current limitations will further expedite gene discovery and lead to increased application of these genetic insights in molecular diagnostics using gene panel and exome sequencing strategies.
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Affiliation(s)
- Aline Verstraeten
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium; Laboratory of Neurogenetics, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Jessie Theuns
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium; Laboratory of Neurogenetics, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium; Laboratory of Neurogenetics, Institute Born Bunge, University of Antwerp, Antwerp, Belgium.
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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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Lee PC, Bordelon Y, Bronstein J, Sinsheimer JS, Farrer M, Ritz B. Head injury, α-synuclein genetic variability and Parkinson's disease. Eur J Neurol 2014; 22:874-8. [PMID: 25370538 DOI: 10.1111/ene.12585] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 08/29/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE Head injury has been linked to Parkinson's disease (PD) in some but not all studies. Differences in the genetic and environmental susceptibility to PD between populations might be one explanation. The joint effects of head injuries and SNCA genetic variants were investigated. METHODS From 2001 to 2012, 561 incident idiopathic PD cases and 721 population controls from central California were enrolled. Subjects reported on head injuries throughout their lifetime and were assessed for genetic variability in the SNCA 5' region (D4S3481; Rep1) and 3' untranslated region (rs356165). In unconditional logistic regression models adjusted for confounders, interactions between head injuries and genetic risk variants were investigated. RESULTS Parkinson's disease risk in individuals with head injury who are carriers of at least one 263 bp allele in D4S3481 or rs356165 variants was 3-4.5-fold higher compared with non-carriers without head injuries. However, tests for interaction between head injury and SNCA D4S3481or rs356165 were not statistically significant. CONCLUSIONS Our study finds some evidence that head injury and D4S3481 or rs356165 variants jointly increase the risk of PD but little evidence of interaction.
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Affiliation(s)
- P C Lee
- Department of Health Care Management, College of Healthcare Administration and Management, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
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25
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Deng H, Yuan L. Genetic variants and animal models in SNCA and Parkinson disease. Ageing Res Rev 2014; 15:161-76. [PMID: 24768741 DOI: 10.1016/j.arr.2014.04.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/08/2014] [Accepted: 04/14/2014] [Indexed: 12/20/2022]
Abstract
Parkinson disease (PD; MIM 168600) is the second most common progressive neurodegenerative disorder characterized by a variety of motor and non-motor features. To date, at least 20 loci and 15 disease-causing genes for parkinsonism have been identified. Among them, the α-synuclein (SNCA) gene was associated with PARK1/PARK4. Point mutations, duplications and triplications in the SNCA gene cause a rare dominant form of PD in familial and sporadic PD cases. The α-synuclein protein, a member of the synuclein family, is abundantly expressed in the brain. The protein is the major component of Lewy bodies and Lewy neurites in dopaminergic neurons in PD. Further understanding of its role in the pathogenesis of PD through various genetic techniques and animal models will likely provide new insights into our understanding, therapy and prevention of PD.
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Affiliation(s)
- Hao Deng
- Center for Experimental Medicine and Department of Neurology, the Third Xiangya Hospital, Central South University, Tongzipo Road 138, Changsha, Hunan 410013, PR China.
| | - Lamei Yuan
- Center for Experimental Medicine and Department of Neurology, the Third Xiangya Hospital, Central South University, Tongzipo Road 138, Changsha, Hunan 410013, PR China
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26
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Linnertz C, Lutz MW, Ervin JF, Allen J, Miller NR, Welsh-Bohmer KA, Roses AD, Chiba-Falek O. The genetic contributions of SNCA and LRRK2 genes to Lewy Body pathology in Alzheimer's disease. Hum Mol Genet 2014; 23:4814-21. [PMID: 24777780 DOI: 10.1093/hmg/ddu196] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The molecular genetic basis that leads to Lewy Body (LB) pathology in 15-20% of Alzheimer disease cases (LBV/AD) was largely unknown. Alpha-synuclein (SNCA) and Leucine-rich repeat kinase2 (LRRK2) have been implicated in the pathogenesis of Parkinson's disease (PD), the prototype of LB spectrum disorders. We tested the association of SNCA variants with LB pathology in AD. We then stratified the SNCA association analyses by LRRK2 genotype. We also investigated the expression regulation of SNCA and LRRK2 in relation to LB pathology. We evaluated the differences in SNCA-mRNA and LRRK2-mRNA levels as a function of LB pathology in the temporal cortex (TC) from autopsy-confirmed LBV/AD cases and AD controls. We further investigated the cis-effect of the LB pathology-associated genetic variants within the SNCA and LRRK2 loci on the mRNA expression of these genes. SNCA SNPs rs3857059 and rs2583988 showed significant associations with increased risk for LB pathology. When the analyses were stratified by LRRK2-rs1491923 genotype, the associations became stronger for both SNPs and an association was also observed with rs2619363. Expression analysis demonstrated that SNCA- and LRRK2-mRNA levels were significantly higher in TC from LBV/AD brains compared with AD controls. Furthermore, SNCA-mRNA expression level in the TC was associated with rs3857059; homozygotes for the minor allele showed significant higher expression. LRRK2-transcript levels were increased in carriers of rs1491923 minor allele. Our findings demonstrated that SNCA contributes to LB pathology in AD patients, possibly via interaction with LRRK2, and suggested that expression regulation of these genes may be the molecular basis underlying the observed LB associations.
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Affiliation(s)
- Colton Linnertz
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael W Lutz
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA, Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, NC 27710, USA
| | - John F Ervin
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Jawara Allen
- Institute for Genome Sciences and Policy, Duke University Medical Center, Durham, NC 27708, USA
| | - Natalie R Miller
- Institute for Genome Sciences and Policy, Duke University Medical Center, Durham, NC 27708, USA
| | - Kathleen A Welsh-Bohmer
- Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, NC 27710, USA
| | - Allen D Roses
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA, Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, NC 27710, USA, Zinfandel Pharmaceuticals, Chapel Hill, NC, USA and
| | - Ornit Chiba-Falek
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA, Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, NC 27710, USA, Institute for Genome Sciences and Policy, Duke University Medical Center, Durham, NC 27708, USA
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Clarimón J, Kulisevsky J. Parkinson's disease: from genetics to clinical practice. Curr Genomics 2014; 14:560-7. [PMID: 24532987 PMCID: PMC3924250 DOI: 10.2174/1389202914666131210212305] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 09/14/2013] [Accepted: 10/31/2013] [Indexed: 12/13/2022] Open
Abstract
Breakthroughs in genetics over the last decade have radically advanced our understanding of the etiological basis
of Parkinson's disease (PD). Although much research remains to be done, the main genetic causes of this neurodegenerative
disorder are now partially unraveled, allowing us to feel more confident that our knowledge about the genetic architecture
of PD will continue to increase exponentially. How and when these discoveries will be introduced into general
clinical practice, however, remains uncertain. In this review, we provide a general summary of the progress in the genetics
of PD and discuss how this knowledge will contribute to the diagnosis and clinical management of patients with, or at risk
of this disorder.
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Affiliation(s)
- Jordi Clarimón
- Neurology Department, Institut d'Investigacions Biomèdiques Sant Pau, Hospital de Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Jaime Kulisevsky
- Neurology Department, Institut d'Investigacions Biomèdiques Sant Pau, Hospital de Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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Oczkowska A, Kozubski W, Lianeri M, Dorszewska J. Mutations in PRKN and SNCA Genes Important for the Progress of Parkinson's Disease. Curr Genomics 2014; 14:502-17. [PMID: 24532983 PMCID: PMC3924246 DOI: 10.2174/1389202914666131210205839] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 11/12/2013] [Accepted: 11/25/2013] [Indexed: 11/30/2022] Open
Abstract
Although Parkinson’s disease (PD) was first described almost 200 years ago, it remains an incurable disease
with a cause that is not fully understood. Nowadays it is known that disturbances in the structure of pathological proteins
in PD can be caused by more than environmental and genetic factors. Despite numerous debates and controversies in the
literature about the role of mutations in the SNCA and PRKN genes in the pathogenesis of PD, it is evident that these
genes play a key role in maintaining dopamine (DA) neuronal homeostasis and that the dysfunction of this homeostasis is
relevant to both familial (FPD) and sporadic (SPD) PD with different onset. In recent years, the importance of alphasynuclein
(ASN) in the process of neurodegeneration and neuroprotective function of the Parkin is becoming better understood.
Moreover, there have been an increasing number of recent reports indicating the importance of the interaction between
these proteins and their encoding genes. Among others interactions, it is suggested that even heterozygous substitution
in the PRKN gene in the presence of the variants +2/+2 or +2/+3 of NACP-Rep1 in the SNCA promoter, may increase
the risk of PD manifestation, which is probably due to ineffective elimination of over-expressed ASN by the mutated
Parkin protein. Finally, it seems that genetic testing may be an important part of diagnostics in patients with PD and may
improve the prognostic process in the course of PD. However, only full knowledge of the mechanism of the interaction
between the genes associated with the pathogenesis of PD is likely to help explain the currently unknown pathways of selective
damage to dopaminergic neurons in the course of PD.
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Affiliation(s)
- Anna Oczkowska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Wojciech Kozubski
- Chair and Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Margarita Lianeri
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, Poznan, Poland
| | - Jolanta Dorszewska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
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29
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Chai C, Lim KL. Genetic insights into sporadic Parkinson's disease pathogenesis. Curr Genomics 2014; 14:486-501. [PMID: 24532982 PMCID: PMC3924245 DOI: 10.2174/1389202914666131210195808] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 09/09/2013] [Accepted: 10/22/2013] [Indexed: 12/23/2022] Open
Abstract
Intensive research over the last 15 years has led to the identification of several autosomal recessive and dominant
genes that cause familial Parkinson’s disease (PD). Importantly, the functional characterization of these genes has
shed considerable insights into the molecular mechanisms underlying the etiology and pathogenesis of PD. Collectively;
these studies implicate aberrant protein and mitochondrial homeostasis as key contributors to the development of PD, with
oxidative stress likely acting as an important nexus between the two pathogenic events. Interestingly, recent genome-wide
association studies (GWAS) have revealed variations in at least two of the identified familial PD genes (i.e. α-synuclein
and LRRK2) as significant risk factors for the development of sporadic PD. At the same time, the studies also uncovered
variability in novel alleles that is associated with increased risk for the disease. Additionally, in-silico meta-analyses of
GWAS data have allowed major steps into the investigation of the roles of gene-gene and gene-environment interactions
in sporadic PD. The emergent picture from the progress made thus far is that the etiology of sporadic PD is multi-factorial
and presumably involves a complex interplay between a multitude of gene networks and the environment. Nonetheless,
the biochemical pathways underlying familial and sporadic forms of PD are likely to be shared.
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Affiliation(s)
- Chou Chai
- Duke-NUS Graduate Medical School, Singapore
| | - Kah-Leong Lim
- Duke-NUS Graduate Medical School, Singapore ; Department of Physiology, National University of Singapore, Singapore ; Neurodegeneration Research Laboratory, National Neuroscience Institute, Singapore
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Gottschalk WK, Lutz MW, He YT, Saunders AM, Burns DK, Roses AD, Chiba-Falek O. The Broad Impact of TOM40 on Neurodegenerative Diseases in Aging. ACTA ACUST UNITED AC 2014; 1. [PMID: 25745640 DOI: 10.13188/2376-922x.1000003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitochondrial dysfunction is an important factor in the pathogenesis of age-related diseases, including neurodegenerative diseases like Alzheimer's and Parkinson's spectrum disorders. A polymorphism in Translocase of the Outer Mitochondrial Membrane - 40 kD (TOMM40) is associated with risk and age-of onset of late-onset AD, and is the only nuclear- encoded gene identified in genetic studies to date that presumably contributes to LOAD-related mitochondria dysfunction. In this review, we describe the TOM40-mediated mitochondrial protein import mechanism, and discuss the evidence linking TOM40 with Alzheimer's (AD) and Parkinson's (PD) diseases. All but 36 of the >~1,500 mitochondrial proteins are encoded by the nucleus and are synthesized on cytoplasmic ribosomes, and most of these are imported into mitochondria through the TOM complex, of which TOM40 is the central pore, mediating communication between the cytoplasm and the mitochondrial interior. APP enters and obstructs the TOM40 pore, inhibiting import of OXPHOS-related proteins and disrupting the mitochondrial redox balance. Other pathogenic proteins, such as Aβ and alpha-synuclein, readily pass through the pore and cause toxic effects by directly inhibiting mitochondrial enzymes. Healthy mitochondria normally import and degrade the PD-related protein Pink1, but Pink1 exits mitochondria if the membrane potential collapses and initiates Parkin-mediated mitophagy. Under normal circumstances, this process helps clear dysfunctional mitochondria and contributes to cellular health, but PINK1 mutations associated with PD exit mitochondria with intact membrane potentials, disrupting mitochondrial dynamics, leading to pathology. Thus, TOM40 plays a central role in the mitochondrial dysfunction that underlies age-related neurodegenerative diseases. Learning about the factors that control TOM40 levels and activity, and how TOM40, specifically, and the TOM complex, generally, interacts with potentially pathogenic proteins, will provide deeper insights to AD and PD pathogenesis, and possibly new targets for preventative and/or therapeutic treatments.
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Affiliation(s)
- William K Gottschalk
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael W Lutz
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yu Ting He
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ann M Saunders
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Zinfandel Pharmaceuticals, Chapel Hill, NC, USA
| | | | - Allen D Roses
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Zinfandel Pharmaceuticals, Chapel Hill, NC, USA
| | - Ornit Chiba-Falek
- Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA ; Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
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Li NN, Mao XY, Chang XL, Zhao DM, Zhang JH, Liao Q, Yu WJ, Tan EK, Peng R. SNCA rs356219 variant increases risk of sporadic Parkinson's disease in ethnic Chinese. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:452-6. [PMID: 23737253 DOI: 10.1002/ajmg.b.32143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 02/07/2013] [Indexed: 02/05/2023]
Abstract
Alpha-synuclein gene (SNCA) polymorphisms have been associated with Parkinson's disease (PD). A recently published genome-wide association study (GWAS) meta-analysis from the USA and Europe found a strong association between SNCA rs356219 and PD. Considering the population-specific heterogeneity, we investigated the role of SNCA rs356219 as PD susceptibility in a large Han Chinese population of 685 patients and 569 controls. The SNCA rs356219-G allele was found to increase the risk to develop PD (OR = 1.81, 95% CI: 1.54-2.13, P = 5.71E-13). The meta-analysis revealed that the frequency of AG + GG genotypes higher in PD than in control subjects (OR = 1.85, 95% CI: 1.56-2.19, P = 0.00001) in the Asian population. PD patients with AG + GG genotypes were associated with earlier age at onset compared with those with AA genotype. No such significant association was observed in the clinical presentation for gender, age at onset, and onset symptoms. Our study provides strong support for the susceptibility role of SNCA rs356219 in sporadic PD in a Han Chinese population from mainland China and the meta-analysis also revealed a similar finding in the Asian population.
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Affiliation(s)
- Nan-Nan Li
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, PR China
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32
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Wu-Chou YH, Chen YT, Yeh TH, Chang HC, Weng YH, Lai SC, Huang CL, Chen RS, Huang YZ, Chen CC, Hung J, Chuang WL, Lin WY, Chen CH, Lu CS. Genetic variants of SNCA and LRRK2 genes are associated with sporadic PD susceptibility: a replication study in a Taiwanese cohort. Parkinsonism Relat Disord 2012. [PMID: 23182315 DOI: 10.1016/j.parkreldis.2012.10.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Parkinson's disease (PD) is one of the most prevalent age-related neurodegenerative diseases and usually refers to a complex disorder with multiple genetic and environmental factors influencing disease risk. We here performed a gene-based case-control association study to scrutinize whether genetic variants in SNCA and LRRK2 genes could predispose to sporadic, late-onset form of PD in Taiwanese population. METHODS 17 Single Nucleotide Polymorphisms (SNPs) markers located within SNCA gene as well as the 16 SNP markers within LRRK2 gene were chosen for genotyping and evaluated their haplotype structure in a cohort of sporadic PD patients and control individuals. RESULTS This study showed that two SNPs near the promoter region (rs2301134 and rs2301135) of SNCA gene gave the greatest evidence for an association with PD (p ≤ 0.01) and a haplotype block with two SNPs in the 3' UTR (rs356221 and rs11931074) revealed another evidence of association (p ≤ 0.02). For the LRRK2 gene, only R1628P variants of total 16 SNPs giving a marginal significant association with PD across the whole gene (p = 0.0058) and no haplotype block was constructed. Many genetic variants (A419V, I1122V, R1441C, R1441G, R1441H, Y1699C, M1869V, M1869T, I2012T, G2019S, and I2020T) from previous reports were not detected in our cohort. CONCLUSIONS We have replicated a population-based PD association study in a collection of 626 cases and 473 control subjects and confirm that genetic variants of both SNCA and LRRK2 genes are associated with susceptibility to sporadic PD but in a different distribution.
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Affiliation(s)
- Yah-Huei Wu-Chou
- Human Molecular Genetics Laboratory, Department of Medical Research, Chang Gung Memorial Hospital and Chang Gung University, Kweishan, Taoyuan, Taiwan
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Khodr CE, Pedapati J, Han Y, Bohn MC. Inclusion of a portion of the native SNCA 3'UTR reduces toxicity of human S129A SNCA on striatal-projecting dopamine neurons in rat substantia nigra. Dev Neurobiol 2012; 72:906-17. [PMID: 22021082 DOI: 10.1002/dneu.20989] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Experimental models of Parkinson's disease (PD) created by aberrant expression of the alpha-synuclein (SNCA) coding region have been reported. However, noncoding regions function in normal physiology and recent in vitro studies have shown that microRNAs-7 and -153 regulate SNCA expression by binding the 3'UTR. Here, effects of different hSNCA forms were examined in vivo. Adult, male rats were injected into one substantia nigra (SN) with AAV-wtSNCA, AAV-S129A hSNCA, or AAV-S129D hSNCA either with or without a portion of the native 3'UTR. DA neurons in SN that maintained striatal (ST) projections at the end of treatment were retrogradely labeled by bilateral ST fluorogold (FG) injections and FG-positive DA neurons in SN were counted. At 5 weeks, hSNCA coding vectors reduced numbers of FG-positive neurons in injected SN compared with uninjected SN (wtSNCA, p = 0.05; S129A/D hSNCA, p = 0.01). At 7 and 9 weeks, wtSNCA- and S129D hSNCA-treated rats exhibited recovery, but S129A hSNCA-injected rats did not (p = 0.01). In contrast, numbers of FG-positive neurons were unaffected by hSNCA expression when the 3'UTR was included. When FG-positive neurons were expressed as the ratio of numbers in injected to uninjected sides, the S129A hSNCA coding vector resulted in the highest decrease at 9 weeks versus wtSNCA (p = 0.05) or S129D hSNCA (p = 0.01). Inclusion of the 3'UTR resulted in no significant differences in FG-positive neuron ratios. These data suggest that inclusion of the 3'UTR protects against S129A hSNCA-induced loss of nigrostriatal-projecting DA neurons in vivo and that mis-regulation of hSNCA expression and function at noncoding regions contribute to PD pathogenesis.
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Affiliation(s)
- Christina E Khodr
- Department of Pediatrics, Neurobiology Program, Children's Memorial Research Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60614, USA
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Miyake Y, Tanaka K, Fukushima W, Kiyohara C, Sasaki S, Tsuboi Y, Yamada T, Oeda T, Shimada H, Kawamura N, Sakae N, Fukuyama H, Hirota Y, Nagai M. SNCA polymorphisms, smoking, and sporadic Parkinson’s disease in Japanese. Parkinsonism Relat Disord 2012; 18:557-61. [DOI: 10.1016/j.parkreldis.2012.02.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/14/2012] [Accepted: 02/15/2012] [Indexed: 02/05/2023]
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Ritz B, Rhodes SL, Bordelon Y, Bronstein J. α-Synuclein genetic variants predict faster motor symptom progression in idiopathic Parkinson disease. PLoS One 2012; 7:e36199. [PMID: 22615757 PMCID: PMC3352914 DOI: 10.1371/journal.pone.0036199] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 04/03/2012] [Indexed: 11/19/2022] Open
Abstract
Currently, there are no reported genetic predictors of motor symptom progression in Parkinson's disease (PD). In familial PD, disease severity is associated with higher α-synuclein (SNCA) expression levels, and in postmortem studies expression varies with SNCA genetic variants. Furthermore, SNCA is a well-known risk factor for PD occurrence. We recruited Parkinson's patients from the communities of three central California counties to investigate the influence of SNCA genetic variants on motor symptom progression in idiopathic PD. We repeatedly assessed this cohort of patients over an average of 5.1 years for motor symptom changes employing the Unified Parkinson's Disease Rating Scale (UPDRS). Of 363 population-based incident PD cases diagnosed less than 3 years from baseline assessment, 242 cases were successfully re-contacted and 233 were re-examined at least once. Of subjects lost to follow-up, 69% were due to death. Adjusting for covariates, risk of faster decline of motor function as measured by annual increase in motor UPDRS exam score was increased 4-fold in carriers of the REP1 263bp promoter variant (OR 4.03, 95%CI:1.57-10.4). Our data also suggest a contribution to increased risk by the G-allele for rs356165 (OR 1.66; 95%CI:0.96-2.88), and we observed a strong trend across categories when both genetic variants were considered (p for trend = 0.002). Our population-based study has demonstrated that SNCA variants are strong predictors of faster motor decline in idiopathic PD. SNCA may be a promising target for therapies and may help identify patients who will benefit most from early interventions. This is the first study to link SNCA to motor symptom decline in a longitudinal progression study.
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Affiliation(s)
- Beate Ritz
- Department of Epidemiology, University of California Los Angeles, Los Angeles, California, United States of America.
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MicroRNAs in Parkinson's disease. Neurobiol Dis 2012; 46:279-84. [PMID: 22245218 DOI: 10.1016/j.nbd.2011.12.046] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 12/15/2011] [Accepted: 12/26/2011] [Indexed: 02/03/2023] Open
Abstract
Besides the classic mutations in coding regions of genes, the critical role of gene expression regulators in disease states is increasingly recognized. The network of small non-coding microRNAs is crucial for the normal development and survival of distinct neuronal populations that are vulnerable in various neurodegenerative disorders. In midbrain dopaminergic neurons, which degenerate in Parkinson's disease (PD) causing motor signs and symptoms, disruption of this network results in their progressive loss associated with impaired motor activity in Drosophila and mouse models. Studies of families with dominantly inherited PD linked to multiplication of the α-synuclein gene locus indicate that the amount of this key pathogenic protein in neurons is an important determinant of its tendency to aggregate pathologically and increase neuronal susceptibility. Recent reports demonstrate that the α-synuclein mRNA is under negative control by at least two microRNAs, miR-7 and miR-153. In addition to studying the regulation of candidate genes by specific microRNA species, different profiling approaches are uncovering variations in the abundance of certain microRNAs that may prove to be relevant to the disease. For example, miR-133b is deficient in the PD midbrain as well as in mouse models, and miR-34b/34c are decreased in several affected brain regions in PD and incidental Lewy body disease. Polymorphisms in the 3'-untranslated region of microRNA target mRNAs, including in the gene encoding α-synuclein found in Genome Wide Association studies, are another potential reason for variations in the rate of protein production and thus disease risk. And finally, the impact of a disease associated gene product, and in particular LRRK2, on the microRNA network compounds the complexity of the interplay between the microRNA system and pathogenic proteins. The wealth of knowledge accumulating from these studies in a few short years holds considerable promise to harness its potential and translate it into therapeutic strategies for PD.
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Abstract
We have witnessed tremendous success in genome-wide association studies (GWAS) in recent years. Since the identification of variants in the complement factor H gene on the risk of age-related macular degeneration, GWAS have become ubiquitous in genetic studies and have led to the identification of genetic variants that are associated with a variety of complex human diseases and traits. These discoveries have changed our understanding of the biological architecture of common, complex diseases and have also provided new hypotheses to test. New tools, such as next-generation sequencing, will be an important part of the future of genetics research; however, GWAS studies will continue to play an important role in disease gene discovery. Many traits have yet to be explored by GWAS, especially in minority populations, and large collaborative studies are currently being conducted to maximize the return from existing GWAS data. In addition, GWAS technology continues to improve, increasing genomic coverage for major global populations and decreasing the cost of experiments. Although much of the variance attributable to genetic factors for many important traits is still unexplained, GWAS technology has been instrumental in mapping over a thousand genes to hundreds of traits. More discoveries are made each month and the scale, quality and quantity of current work has a steady trend upward. We briefly review the current key trends in GWAS, which can be summarized with three goals: increase power, increase collaborations and increase populations.
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Corti O, Lesage S, Brice A. What genetics tells us about the causes and mechanisms of Parkinson's disease. Physiol Rev 2011; 91:1161-218. [PMID: 22013209 DOI: 10.1152/physrev.00022.2010] [Citation(s) in RCA: 413] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Parkinson's disease (PD) is a common motor disorder of mysterious etiology. It is due to the progressive degeneration of the dopaminergic neurons of the substantia nigra and is accompanied by the appearance of intraneuronal inclusions enriched in α-synuclein, the Lewy bodies. It is becoming increasingly clear that genetic factors contribute to its complex pathogenesis. Over the past decade, the genetic basis of rare PD forms with Mendelian inheritance, representing no more than 10% of the cases, has been investigated. More than 16 loci and 11 associated genes have been identified so far; genome-wide association studies have provided convincing evidence that polymorphic variants in these genes contribute to sporadic PD. The knowledge acquired of the functions of their protein products has revealed pathways of neurodegeneration that may be shared between inherited and sporadic PD. An impressive set of data in different model systems strongly suggest that mitochondrial dysfunction plays a central role in clinically similar, early-onset autosomal recessive PD forms caused by parkin and PINK1, and possibly DJ-1 gene mutations. In contrast, α-synuclein accumulation in Lewy bodies defines a spectrum of disorders ranging from typical late-onset PD to PD dementia and including sporadic and autosomal dominant PD forms due to mutations in SCNA and LRRK2. However, the pathological role of Lewy bodies remains uncertain, as they may or may not be present in PD forms with one and the same LRRK2 mutation. Impairment of autophagy-based protein/organelle degradation pathways is emerging as a possible unifying but still fragile pathogenic scenario in PD. Strengthening these discoveries and finding other convergence points by identifying new genes responsible for Mendelian forms of PD and exploring their functions and relationships are the main challenges of the next decade. It is also the way to follow to open new promising avenues of neuroprotective treatment for this devastating disorder.
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Affiliation(s)
- Olga Corti
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière; Institut National de la Santé et de la Recherche Médicale U.975, Paris, France
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A search for SNCA 3' UTR variants identified SNP rs356165 as a determinant of disease risk and onset age in Parkinson's disease. J Mol Neurosci 2011; 47:425-30. [PMID: 22076805 DOI: 10.1007/s12031-011-9669-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 10/25/2011] [Indexed: 01/06/2023]
Abstract
Alpha-synuclein gene (SNCA) polymorphisms have been associated with the common sporadic form of Parkinson's disease (PD). We searched for DNA variants at the SNCA 3' UTR through single strand conformation analysis and direct sequencing in a cohort of Spanish PD patients and controls. We have genotyped the rs356165 SNCA 3' UTR polymorphism in a total of 1,135 PD patients and 772 healthy controls from two Spanish cohorts (Asturias and Navarre). We identified six SNCA 3' UTR variants. Single nucleotide polymorphism (SNP) rs356165 was significantly associated with PD risk in the Spanish cohort (p = 0.0001; odd ratio = 1.37, 95%CI = 1.19-1.58). This SNP was also significantly associated with early age at onset of PD. Our work highlights rs356165 as an important determinant of the risk of developing PD and early age at onset and encourages future research to identify a functional effect on SNCA expression.
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40
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Elcoroaristizabal Martín X, Gómez Busto F, González Fernández MC, de Pancorbo MM. [Role of genetics in the etiology of synucleinopathies]. Rev Esp Geriatr Gerontol 2011; 46 Suppl 1:3-11. [PMID: 22152908 DOI: 10.1016/j.regg.2011.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The protein family known as synucleins is composed of α-, β- and γ-synuclein. The most widely studied is the α-synuclein protein due to its participation in essential processes of the central nervous system. Neurotoxicity of this protein is related to the presence of multiplications (duplications and triplications) and point mutations in the gene sequence of the α-synuclein gene (SNCA), differential expression of its isoforms and variations in post-transductional modifications. Neurotoxicity is also related to cytoplasmic inclusions known as Lewy bodies (LBs) and Lewy neurites (LNs), which are also present in α-synucleinopathies. In general, the β-synuclein protein, codified by the SNCB gene, acts as a regulator of processes triggered by α-synuclein and its function is altered by variations in the gene sequence, while γ-synuclein, codified by the SNCG gene, seems to play a major role in certain tumoral processes.
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Affiliation(s)
- Xabier Elcoroaristizabal Martín
- Grupo de Investigación BIOMICS, Departamento de Biología Celular A, Centro de Investigación y Estudios Avanzados Lucio Lascaray, Universidad del País Vasco UPV/EHU, Vitoria-Gasteiz, España
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Variant in the 3′ region of SNCA associated with Parkinson’s disease and serum α-synuclein levels. J Neurol 2011; 259:497-504. [DOI: 10.1007/s00415-011-6209-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 07/29/2011] [Indexed: 11/30/2022]
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Pihlstrøm L, Toft M. Genetic variability in SNCA and Parkinson's disease. Neurogenetics 2011; 12:283-93. [PMID: 21800132 DOI: 10.1007/s10048-011-0292-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 07/04/2011] [Indexed: 11/26/2022]
Abstract
Over the last decades, increasing knowledge about the genetic architecture of Parkinson's disease has provided novel insights into the pathogenesis of the disorder, generating hypotheses for further research. Characterizing the role of SNCA, encoding the α-synuclein protein, has been a particularly important aspect of this development. The identification of SNCA as the first gene implicated in monogenic parkinsonism led to the recognition of α-synuclein as a key protein in the pathogenesis and a major component of pathological hallmark lesions. An association between common variants in SNCA and risk of sporadic Parkinson's disease has been established through numerous studies. We review our current understanding of SNCA variability contributing to Parkinson's disease, highlighting the characterization of functionally relevant susceptibility alleles as a major future challenge. We argue that new strategies will be needed to pinpoint the variants that are ultimately responsible for the signals detected in association studies, where targeted resequencing may represent an attractive initial approach.
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Affiliation(s)
- Lasse Pihlstrøm
- Department of Neurology, Oslo University Hospital, Rikshospitalet, P.O. Box 4950, Nydalen, 0424 Oslo, Norway.
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Burbulla LF, Krüger R. Converging environmental and genetic pathways in the pathogenesis of Parkinson's disease. J Neurol Sci 2011; 306:1-8. [PMID: 21513949 DOI: 10.1016/j.jns.2011.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 04/04/2011] [Accepted: 04/04/2011] [Indexed: 12/21/2022]
Abstract
As a prototypic neurodegenerative disorder Parkinson's disease (PD) is characterized by the progressive loss of specific neuronal subpopulations leading to a late-onset movement disorder. Based on familial forms of PD, to date a significant number of genes were identified that allowed first insight into the molecular pathogenesis of this common movement disorder. These pathways include impaired protein degradation and subsequent aggregation within neuronal cells and impaired mitochondrial function followed by energy depletion due to oxidative stress leading to cell death. The respective disease models were supported by pathoanatomical and biochemical findings in brains of sporadic PD patients without apparent genetic contribution to pathogenesis. Indeed recent genetic and epidemiological studies hint to a complex interplay of genetic susceptibility factors and environmental risk factors to converge to processes of pathological protein accumulation and mitochondrial damage that trigger neurodegeneration in PD. Therefore large-scale geneticoepidemiological studies combining genetic whole genome approaches with a detailed ascertainment of environmental exposures are expected to provide important clues to decipher the complexity of neurodegeneration of this most frequent neurodegenerative movement disorder.
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Affiliation(s)
- Lena F Burbulla
- Laboratory of Functional Neurogenomics, Center of Neurology, Hertie-Institute for Clinical Brain Research and German Research Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
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Johansen KK, Jørgensen JV, White LR, Farrer MJ, Aasly JO. Parkinson-related genetics in patients treated with deep brain stimulation. Acta Neurol Scand 2011; 123:201-6. [PMID: 20545633 DOI: 10.1111/j.1600-0404.2010.01387.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To analyze the frequency of mutations associated with Parkinson's disease (PD) in a general PD population compared to patients with PD selected for deep brain stimulation (DBS) and evaluate the outcome of surgery. MATERIAL AND METHODS A total of 630 consecutive patients with PD were genetically screened, and 60 had DBS surgery, 37 subthalamic nucleus (STN), 21 ventrointermediate nucleus of thalamus (VIM), and two globus pallidus internus (GPi). RESULTS Mutations in LRRK2, PRKN, and PINK1 were found: the first two of these being overrepresented in STN-operated patients, but none being found in VIM-operated patients. Clinical outcome of the surgery was similar in patients with mutations compared to those without. CONCLUSIONS In a consecutive PD population, patients treated with STN-DBS are overrepresented for PD-related mutations and they seem to benefit from DBS as well as patients without mutations.
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Affiliation(s)
- K K Johansen
- Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.
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Abstract
Parkinson's disease (PD) is a primary neurodegenerative movement disorder. In most cases it occurs as a sporadic type of disease, but there are also rare familial forms. Pathologically Parkinson's disease is characterized by loss of dopaminergic neurons in the compact part of substantia nigra. As a part of the neurodegenerative process protein aggregates will accumulate as Lewy bodies in dopaminergic neurons (1). In addition, non-dopaminergic neurons are known to be affected in Parkinsons's disease, for example, in several brain stem nuclei and the olfactoric bulb (2-4). The pathogenic process underlying the death of dopaminergic neurons is far from fully understood. Along with mitochondrial dysfunction, excitotoxicity, neuroinflammation and oxidative stress (5-8), recent evidence indicates that accumulation of protein filaments in Lewy bodies actively takes part in the degeneration of neurons. This will be further discussed below.
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Affiliation(s)
- V Gundersen
- Department of Anatomy and the CMBN, University of Oslo, Oslo, Norway.
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Abstract
In view of the population-specific heterogeneity in reported genetic risk factors for Parkinson's disease (PD), we conducted a genome-wide association study (GWAS) in a large sample of PD cases and controls from the Netherlands. After quality control (QC), a total of 514,799 SNPs genotyped in 772 PD cases and 2024 controls were included in our analyses. Direct replication of SNPs within SNCA and BST1 confirmed these two genes to be associated with PD in the Netherlands (SNCA, rs2736990: P = 1.63 × 10(-5), OR = 1.325 and BST1, rs12502586: P = 1.63 × 10(-3), OR = 1.337). Within SNCA, two independent signals in two different linkage disequilibrium (LD) blocks in the 3' and 5' ends of the gene were detected. Besides, post-hoc analysis confirmed GAK/DGKQ, HLA and MAPT as PD risk loci among the Dutch (GAK/DGKQ, rs2242235: P = 1.22 × 10(-4), OR = 1.51; HLA, rs4248166: P = 4.39 × 10(-5), OR = 1.36; and MAPT, rs3785880: P = 1.9 × 10(-3), OR = 1.19).
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Mata IF, Shi M, Agarwal P, Chung KA, Edwards KL, Factor SA, Galasko DR, Ginghina C, Griffith A, Higgins DS, Kay DM, Kim H, Leverenz JB, Quinn JF, Roberts JW, Samii A, Snapinn KW, Tsuang DW, Yearout D, Zhang J, Payami H, Zabetian CP. SNCA variant associated with Parkinson disease and plasma alpha-synuclein level. ACTA ACUST UNITED AC 2010; 67:1350-6. [PMID: 21060011 DOI: 10.1001/archneurol.2010.279] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND A functional repeat polymorphism in the SNCA promoter (REP1) conveys susceptibility for Parkinson disease (PD). There is also increasing evidence that single-nucleotide polymorphisms (SNPs) elsewhere in the gene are associated with PD risk. OBJECTIVES To further explore the association of common SNCA SNPs with PD susceptibility, to determine whether evidence of allelic heterogeneity exists, and to examine the correlation between PD-associated variants and plasma α-synuclein levels. DESIGN Two-tiered analysis. SETTING Academic research. PATIENTS Patients and control subjects from the NeuroGenetics Research Consortium. MAIN OUTCOME MEASURES We performed a 2-tiered analysis of 1956 patients with PD and 2112 controls from the NeuroGenetics Research Consortium using a comprehensive tag SNP approach. Previously published REP1 genotypes were also included. Plasma α-synuclein was assayed in 86 patients with PD and 78 controls using a highly sensitive Luminex assay. RESULTS Five of 15 SNPs genotyped were associated with PD under an additive model in tier 1 (α = .05). Of these, 4 were successfully replicated in tier 2. In the combined sample, the most significant marker was rs356219 (odds ratio, 1.41; 95% confidence interval, 1.28-1.55; P = 1.6 × 10(-12)), located approximately 9 kilobases downstream from the gene. A regression model containing rs356219 alone best fit the data. The linkage disequilibrium correlation coefficient between this SNP and REP1 was low (r(2) = 0.09). The risk-associated C allele of rs356219 was also correlated with higher transformed plasma α-synuclein levels in patients under an adjusted additive model (P = .005). CONCLUSIONS Our data suggest that 1 or more unidentified functional SNCA variants modify risk for PD and that the effect is larger than and independent of REP1. This variant(s), tagged by rs356219, might act by upregulating SNCA expression in a dose-dependent manner.
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Affiliation(s)
- Ignacio F Mata
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Mailstop S-182, 1660 S Columbian Way, Seattle, WA 98108, USA
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Vefring H, Haugarvoll K, Tysnes OB, Larsen JP, Kurz MW. The role of APOE alleles in incident Parkinson's disease. The Norwegian ParkWest Study. Acta Neurol Scand 2010; 122:438-41. [PMID: 20456244 DOI: 10.1111/j.1600-0404.2010.01362.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Apolipoprotein E (APOE) gene alleles have been associated with various neurodegenerative disorders. However, there have been conflicting reports on associations between APOE alleles and Parkinson's disease (PD) and age at onset in PD. There exist no data on APOE alleles in an unselected cohort of patients with incident PD. PATIENTS AND METHODS To determine the role of APOE alleles in PD and age of onset in PD at time of diagnosis, 203 patients with incident PD and 187 healthy control subjects from Western and Southern Norway were investigated according to their APOE allele status. RESULTS No association was observed between any APOE alleles and susceptibility to PD or age at onset in PD. CONCLUSION In our cohort of unselected, incident PD patients APOE alleles do not seem to play a role for development of PD. Prospective, long-term follow-up may still reveal associations between APOE alleles and clinical and neuropsychological progression in PD.
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Affiliation(s)
- H Vefring
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway.
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McCarthy JJ, Linnertz C, Saucier L, Burke JR, Hulette CM, Welsh-Bohmer KA, Chiba-Falek O. The effect of SNCA 3' region on the levels of SNCA-112 splicing variant. Neurogenetics 2010; 12:59-64. [PMID: 21046180 DOI: 10.1007/s10048-010-0263-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 10/13/2010] [Indexed: 10/18/2022]
Abstract
Genetic variability at the 3' region of SNCA locus has been repeatedly associated with susceptibility to sporadic Parkinson's disease (PD). Accumulated evidence emphasizes the importance of SNCA dosage and expression levels in PD pathogenesis. However, the mechanism through which the 3' region of SNCA gene modulates the risk to develop sporadic PD remained elusive. We studied the effect of PD risk-associated variants at SNCA 3' regions on SNCA112-mRNA (exon 5 in-frame skipping) levels in vivo in 117 neuropathologically normal, human brain frontal cortex samples. SNPs tagging the SNCA 3' showed significant effects on the relative levels of SNCA112-mRNA from total SNCA transcripts levels. The "risk" alleles were correlated with increased expression ratio of SNCA112-mRNA from total. We provide evidence for functional consequences of PD-associated SNCA gene variants at the 3' region, suggesting that genetic regulation of SNCA splicing plays an important role in the development of the disease. Further studies to determine the definite functional variant/s within SNCA 3'and to establish their association with PD pathology are necessary.
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Affiliation(s)
- Jeanette J McCarthy
- Institute for Genome Sciences & Policy, Duke University, DUMC, Box 3445, Durham, NC 27710, USA
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Nuytemans K, Theuns J, Cruts M, Van Broeckhoven C. Genetic etiology of Parkinson disease associated with mutations in the SNCA, PARK2, PINK1, PARK7, and LRRK2 genes: a mutation update. Hum Mutat 2010; 31:763-80. [PMID: 20506312 PMCID: PMC3056147 DOI: 10.1002/humu.21277] [Citation(s) in RCA: 353] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 04/21/2010] [Accepted: 04/21/2010] [Indexed: 12/13/2022]
Abstract
To date, molecular genetic analyses have identified over 500 distinct DNA variants in five disease genes associated with familial Parkinson disease; alpha-synuclein (SNCA), parkin (PARK2), PTEN-induced putative kinase 1 (PINK1), DJ-1 (PARK7), and Leucine-rich repeat kinase 2 (LRRK2). These genetic variants include approximately 82% simple mutations and approximately 18% copy number variations. Some mutation subtypes are likely underestimated because only few studies reported extensive mutation analyses of all five genes, by both exonic sequencing and dosage analyses. Here we present an update of all mutations published to date in the literature, systematically organized in a novel mutation database (http://www.molgen.ua.ac.be/PDmutDB). In addition, we address the biological relevance of putative pathogenic mutations. This review emphasizes the need for comprehensive genetic screening of Parkinson patients followed by an insightful study of the functional relevance of observed genetic variants. Moreover, while capturing existing data from the literature it became apparent that several of the five Parkinson genes were also contributing to the genetic etiology of other Lewy Body Diseases and Parkinson-plus syndromes, indicating that mutation screening is recommendable in these patient groups.
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Affiliation(s)
- Karen Nuytemans
- Neurodegenerative Brain Diseases Group, Department of Molecular GeneticsVIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of AntwerpAntwerpen, Belgium
| | - Jessie Theuns
- Neurodegenerative Brain Diseases Group, Department of Molecular GeneticsVIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of AntwerpAntwerpen, Belgium
| | - Marc Cruts
- Neurodegenerative Brain Diseases Group, Department of Molecular GeneticsVIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of AntwerpAntwerpen, Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases Group, Department of Molecular GeneticsVIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of AntwerpAntwerpen, Belgium
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