1
|
Weber JJ, Czisch L, Pereira Sena P, Fath F, Huridou C, Schwarz N, Incebacak Eltemur RD, Würth A, Weishäupl D, Döcker M, Blumenstock G, Martins S, Sequeiros J, Rouleau GA, Jardim LB, Saraiva-Pereira ML, França MC, Gordon CR, Zaltzman R, Cornejo-Olivas MR, van de Warrenburg BPC, Durr A, Brice A, Bauer P, Klockgether T, Schöls L, Riess O, Schmidt T. The parkin V380L variant is a genetic modifier of Machado-Joseph disease with impact on mitophagy. Acta Neuropathol 2024; 148:14. [PMID: 39088078 PMCID: PMC11294389 DOI: 10.1007/s00401-024-02762-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 08/02/2024]
Abstract
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative spinocerebellar ataxia caused by a polyglutamine-coding CAG repeat expansion in the ATXN3 gene. While the CAG length correlates negatively with the age at onset, it accounts for approximately 50% of its variability only. Despite larger efforts in identifying contributing genetic factors, candidate genes with a robust and plausible impact on the molecular pathogenesis of MJD are scarce. Therefore, we analysed missense single nucleotide polymorphism variants in the PRKN gene encoding the Parkinson's disease-associated E3 ubiquitin ligase parkin, which is a well-described interaction partner of the MJD protein ataxin-3, a deubiquitinase. By performing a correlation analysis in the to-date largest MJD cohort of more than 900 individuals, we identified the V380L variant as a relevant factor, decreasing the age at onset by 3 years in homozygous carriers. Functional analysis in an MJD cell model demonstrated that parkin V380L did not modulate soluble or aggregate levels of ataxin-3 but reduced the interaction of the two proteins. Moreover, the presence of parkin V380L interfered with the execution of mitophagy-the autophagic removal of surplus or damaged mitochondria-thereby compromising cell viability. In summary, we identified the V380L variant in parkin as a genetic modifier of MJD, with negative repercussions on its molecular pathogenesis and disease age at onset.
Collapse
Affiliation(s)
- Jonasz J Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, 44801, Bochum, Germany
| | - Leah Czisch
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Priscila Pereira Sena
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Florian Fath
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, 44801, Bochum, Germany
| | - Chrisovalantou Huridou
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, 44801, Bochum, Germany
| | - Natasa Schwarz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Rana D Incebacak Eltemur
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
- Department of Human Genetics, Ruhr University Bochum, 44801, Bochum, Germany
| | - Anna Würth
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Daniel Weishäupl
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Miriam Döcker
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Gunnar Blumenstock
- Department of Clinical Epidemiology and Applied Biometry, University of Tübingen, 72076, Tübingen, Germany
| | - Sandra Martins
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal
- IPATIMUP - Institute of Molecular Pathology and Immunology, University of Porto, 4200-135, Porto, Portugal
| | - Jorge Sequeiros
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135, Porto, Portugal
- ICBAS School of Medicine and Biomedical Sciences, University of Porto, 4050-313, Porto, Portugal
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery and The Neuro (Montreal Neurological Institute-Hospital), McGill University, Montréal, H3A 1A1, Canada
| | - Laura Bannach Jardim
- Departamento de Medicina Interna, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, 90035-903, Brazil
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, 90035-903, Brazil
| | - Maria-Luiza Saraiva-Pereira
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, 90035-903, Brazil
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, 90035-003, Brazil
| | - Marcondes C França
- Universidade Estadual de Campinas (UNICAMP), Campinas, 13083-970, Brazil
| | - Carlos R Gordon
- Department of Neurology, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Roy Zaltzman
- Department of Neurology, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Mario R Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 15003, Lima, Peru
- Neurogenetics Working Group, Universidad Científica del Sur, 15067, Lima, Peru
| | - Bart P C van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6525, Nijmegen, The Netherlands
| | - Alexandra Durr
- Department of Genetics and Cytogenetics, 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, 75013, Paris, France
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, University Hospital Pitié-Salpêtrière, 75013, Paris, France
| | - Alexis Brice
- Department of Genetics and Cytogenetics, 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, 75013, Paris, France
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, University Hospital Pitié-Salpêtrière, 75013, Paris, France
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
- Centogene GmbH, 18055, Rostock, Germany
- Clinic for Internal Medicine, Department of Hematology, Oncology, Palliative Medicine, University Medicine Rostock, 18057, Rostock, Germany
| | - Thomas Klockgether
- German Center for Neurodegenerative Diseases (DZNE), 53127, Bonn, Germany
- Department of Neurology, University Hospital Bonn, 53127, Bonn, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076, Tübingen, Germany
- German Center of Neurodegenerative Diseases (DZNE), 72076, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Thorsten Schmidt
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.
| |
Collapse
|
2
|
Rajagopal S, Donaldson J, Flower M, Hensman Moss DJ, Tabrizi SJ. Genetic modifiers of repeat expansion disorders. Emerg Top Life Sci 2023; 7:325-337. [PMID: 37861103 PMCID: PMC10754329 DOI: 10.1042/etls20230015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/20/2023] [Accepted: 10/09/2023] [Indexed: 10/21/2023]
Abstract
Repeat expansion disorders (REDs) are monogenic diseases caused by a sequence of repetitive DNA expanding above a pathogenic threshold. A common feature of the REDs is a strong genotype-phenotype correlation in which a major determinant of age at onset (AAO) and disease progression is the length of the inherited repeat tract. Over a disease-gene carrier's life, the length of the repeat can expand in somatic cells, through the process of somatic expansion which is hypothesised to drive disease progression. Despite being monogenic, individual REDs are phenotypically variable, and exploring what genetic modifying factors drive this phenotypic variability has illuminated key pathogenic mechanisms that are common to this group of diseases. Disease phenotypes are affected by the cognate gene in which the expansion is found, the location of the repeat sequence in coding or non-coding regions and by the presence of repeat sequence interruptions. Human genetic data, mouse models and in vitro models have implicated the disease-modifying effect of DNA repair pathways via the mechanisms of somatic mutation of the repeat tract. As such, developing an understanding of these pathways in the context of expanded repeats could lead to future disease-modifying therapies for REDs.
Collapse
Affiliation(s)
- Sangeerthana Rajagopal
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, U.K
- UK Dementia Research Institute, University College London, London WCC1N 3BG, U.K
| | - Jasmine Donaldson
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, U.K
- UK Dementia Research Institute, University College London, London WCC1N 3BG, U.K
| | - Michael Flower
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, U.K
- UK Dementia Research Institute, University College London, London WCC1N 3BG, U.K
| | - Davina J Hensman Moss
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, U.K
- UK Dementia Research Institute, University College London, London WCC1N 3BG, U.K
- St George's University of London, London SW17 0RE, U.K
| | - Sarah J Tabrizi
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, U.K
- UK Dementia Research Institute, University College London, London WCC1N 3BG, U.K
| |
Collapse
|
3
|
Genetic Variation in ATXN3 (Ataxin-3) 3'UTR: Insights into the Downstream Regulatory Elements of the Causative Gene of Machado-Joseph Disease/Spinocerebellar Ataxia Type 3. CEREBELLUM (LONDON, ENGLAND) 2023; 22:37-45. [PMID: 35034258 DOI: 10.1007/s12311-021-01358-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/09/2021] [Indexed: 02/01/2023]
Abstract
Untranslated regions are involved in the regulation of transcriptional and post-transcriptional processes. Characterization of these regions remains poorly explored for ATXN3, the causative gene of Machado-Joseph disease (MJD). Although a few genetic modifiers have been identified for MJD age at onset (AO), they only explain a small fraction of the AO variance. Our aim was to analyse variation at the 3'UTR of ATXN3 in MJD patients, analyse its impact on AO and attempt to build haplotypes that might discriminate between normal and expanded alleles.After assessing ATXN3 3'UTR variants in molecularly confirmed MJD patients, an in silico analysis was conducted to predict their functional impact (e.g. their effect on miRNA-binding sites). Alleles in cis with the expanded (CAG)n were inferred from family data, and haplotypes were built. The effect of the alternative alleles on the AO and on SARA and NESSCA ataxia scales was tested.Nine variants, all previously described, were found. For eight variants, in silico analyses predicted (a) deleterious effects (rs10151135; rs55966267); (b) changes on miRNA-binding sites (rs11628764; rs55966267; rs709930) and (c) alterations of RNA-binding protein (RBP)-binding sites (rs1055996; rs910369; rs709930; rs10151135; rs3092822; rs7158733). Patients harbouring the alternative allele at rs10151135 had significantly higher SARA Axial subscores (p = 0.023), comparatively with those homozygous for the reference allele. Ten different haplotypes were obtained, one of which was exclusively found in cis with the expanded and four with the normal allele. These findings, which are relevant for the design of allele-specific therapies, warrant further investigation in independent MJD cohorts.
Collapse
|
4
|
Jin X, Tanaka H, Jin M, Fujita K, Homma H, Inotsume M, Yong H, Umeda K, Kodera N, Ando T, Okazawa H. PQBP5/NOL10 maintains and anchors the nucleolus under physiological and osmotic stress conditions. Nat Commun 2023; 14:9. [PMID: 36599853 PMCID: PMC9813255 DOI: 10.1038/s41467-022-35602-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
Polyglutamine binding protein 5 (PQBP5), also called nucleolar protein 10 (NOL10), binds to polyglutamine tract sequences and is expressed in the nucleolus. Using dynamic imaging of high-speed atomic force microscopy, we show that PQBP5/NOL10 is an intrinsically disordered protein. Super-resolution microscopy and correlative light and electron microscopy method show that PQBP5/NOL10 makes up the skeletal structure of the nucleolus, constituting the granule meshwork in the granular component area, which is distinct from other nucleolar substructures, such as the fibrillar center and dense fibrillar component. In contrast to other nucleolar proteins, which disperse to the nucleoplasm under osmotic stress conditions, PQBP5/NOL10 remains in the nucleolus and functions as an anchor for reassembly of other nucleolar proteins. Droplet and thermal shift assays show that the biophysical features of PQBP5/NOL10 remain stable under stress conditions, explaining the spatial role of this protein. PQBP5/NOL10 can be functionally depleted by sequestration with polyglutamine disease proteins in vitro and in vivo, leading to the pathological deformity or disappearance of the nucleolus. Taken together, these findings indicate that PQBP5/NOL10 is an essential protein needed to maintain the structure of the nucleolus.
Collapse
Affiliation(s)
- Xiaocen Jin
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Hikari Tanaka
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Meihua Jin
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Kyota Fujita
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Hidenori Homma
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Maiko Inotsume
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Huang Yong
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Kenichi Umeda
- Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan
| | - Noriyuki Kodera
- Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan
| | - Toshio Ando
- Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan
| | - Hitoshi Okazawa
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
- Center for Brain Integration Research, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
| |
Collapse
|
5
|
Lee YH, Tsai YS, Chang CC, Ho CC, Shih HM, Chen HM, Lai HL, Lee CW, Lee YC, Liao YC, Yang UC, Cheng TH, Chern Y, Soong BW. A PIAS1 Protective Variant S510G Delays polyQ Disease Onset by Modifying Protein Homeostasis. Mov Disord 2021; 37:767-777. [PMID: 34951052 DOI: 10.1002/mds.28896] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/18/2021] [Accepted: 12/09/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Polyglutamine (polyQ) diseases are dominant neurodegenerative diseases caused by an expansion of the polyQ-encoding CAG repeats in the disease-causing gene. The length of the CAG repeats is the major determiner of the age at onset (AO) of polyQ diseases, including Huntington's disease (HD) and spinocerebellar ataxia type 3 (SCA3). OBJECTIVE We set out to identify common genetic variant(s) that may affect the AO of polyQ diseases. METHODS Three hundred thirty-seven patients with HD or SCA3 were enrolled for targeted sequencing of 583 genes implicated in proteinopathies. In total, 16 genes were identified as containing variants that are associated with late AO of polyQ diseases. For validation, we further investigate the variants of PIAS1 because PIAS1 is an E3 SUMO (small ubiquitin-like modifier) ligase for huntingtin (HTT), the protein linked to HD. RESULTS Biochemical analyses revealed that the ability of PIAS1S510G to interact with mutant huntingtin (mHTT) was less than that of PIAS1WT , resulting in lower SUMOylation of mHTT and lower accumulation of insoluble mHTT. Genetic knock-in of PIAS1S510G in a HD mouse model (R6/2) ameliorated several HD-like deficits (including shortened life spans, poor grip strength and motor coordination) and reduced neuronal accumulation of mHTT. CONCLUSIONS Our findings suggest that PIAS1 is a genetic modifier of polyQ diseases. The naturally occurring variant, PIAS1S510G , is associated with late AO in polyQ disease patients and milder disease severity in HD mice. Our study highlights the possibility of targeting PIAS1 or pathways governing protein homeostasis as a disease-modifying approach for treating patients with HD.
Collapse
Affiliation(s)
- Yan Hua Lee
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yu-Shuen Tsai
- Center for Systems and Synthetic Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Che-Chang Chang
- The Ph.D. Program for Translational Medicine and International Ph.D. Program for Translational Science, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chun-Chen Ho
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsiu-Ming Shih
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hui-Mei Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsing-Lin Lai
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chia-Wei Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yi-Chung Lee
- Department of Neurology, Taipei Veterans General Hospital, and Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Chu Liao
- Department of Neurology, Taipei Veterans General Hospital, and Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ueng-Cheng Yang
- Center for Systems and Synthetic Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Tzu-Hao Cheng
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, and Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yijuang Chern
- Taiwan International Graduate Program in Molecular Medicine, National Yang Ming Chiao Tung University and Academia Sinica, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Bing-Wen Soong
- Department of Neurology, Taipei Veterans General Hospital, and Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Department of Neurology, Shuang Ho Hospital, and Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan
| |
Collapse
|
6
|
Raj K, Akundi RS. Mutant Ataxin-3-Containing Aggregates (MATAGGs) in Spinocerebellar Ataxia Type 3: Dynamics of the Disorder. Mol Neurobiol 2021; 58:3095-3118. [PMID: 33629274 DOI: 10.1007/s12035-021-02314-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 01/25/2021] [Indexed: 11/25/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is the most common type of SCA worldwide caused by abnormal polyglutamine expansion in the coding region of the ataxin-3 gene. Ataxin-3 is a multi-faceted protein involved in various cellular processes such as deubiquitination, cytoskeletal organisation, and transcriptional regulation. The presence of an expanded poly(Q) stretch leads to altered processing and misfolding of the protein culminating in the production of insoluble protein aggregates in the cell. Various post-translational modifications affect ataxin-3 fibrillation and aggregation. This review provides an exhaustive assessment of the various pathogenic mechanisms undertaken by the mutant ataxin-3-containing aggregates (MATAGGs) for disease induction and neurodegeneration. This includes in-depth discussion on MATAGG dynamics including their formation, role in neuronal pathogenesis, and the debate over the toxic v/s protective nature of the MATAGGs in disease progression. Additionally, the currently available therapeutic strategies against SCA3 have been reviewed. The shift in the focus of such strategies, from targeting the steps that lead to or reduce aggregate formation to targeting the expression of mutant ataxin-3 itself via RNA-based therapeutics, has also been presented. We also discuss the intriguing promise that various growth and neurotrophic factors, especially the insulin pathway, hold in the modulation of SCA3 progression. These emerging areas show the newer directions through which SCA3 can be targeted including various preclinical and clinical trials. All these advances made in the last three decades since the discovery of the ataxin-3 gene have been critically reviewed here.
Collapse
Affiliation(s)
- Kritika Raj
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India
| | - Ravi Shankar Akundi
- Neuroinflammation Research Lab, Faculty of Life Sciences and Biotechnology, South Asian University, Chanakyapuri, New Delhi, 110021, India.
| |
Collapse
|
7
|
Sena LS, Dos Santos Pinheiro J, Saraiva-Pereira ML, Jardim LB. Selective forces acting on spinocerebellar ataxia type 3/Machado-Joseph disease recurrency: A systematic review and meta-analysis. Clin Genet 2020; 99:347-358. [PMID: 33219521 DOI: 10.1111/cge.13888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/25/2020] [Accepted: 11/17/2020] [Indexed: 12/22/2022]
Abstract
Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is a dominant neurodegenerative disease caused by the expansion of a CAG repeat tract in ATXN3. Anticipation and worsening of clinical picture in subsequent generations were repeatedly reported, but there is no indication that SCA3/MJD frequency is changing. Thus, we performed a systematic review and meta-analysis on phenomena with potential effect on SCA3/MJD recurrency in populations: instability of CAG repeat transmissions, anticipation, fitness, and segregation of alleles. Transmission of the mutant allele was associated with an increase of 1.23 CAG repeats in the next generation, and the average change in age at onset showed an anticipation of 7.75 years per generation; but biased recruitments cannot be ruled out. Affected SCA3/MJD individuals had 45% more children than related controls. Transmissions from SCA3/MJD carriers showed that the expanded allele was segregated in 64% of their children. In contrast, transmissions from normal subjects showed that the minor allele was segregated in 54%. The present meta-analysis concluded that there is a segregation distortion favoring the expanded allele, among children of carriers. Therefore, further studies on transmissions and anticipation phenomena as well as more observations about fertility are required to clarify these selective forces over SCA3/MJD.
Collapse
Affiliation(s)
- Lucas Schenatto Sena
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Jordânia Dos Santos Pinheiro
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional, Porto Alegre, Brazil
| | - Laura Bannach Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional, Porto Alegre, Brazil.,Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| |
Collapse
|
8
|
Akçimen F, Ross JP, Liao C, Spiegelman D, Dion PA, Rouleau GA. Expanded CAG Repeats in ATXN1, ATXN2, ATXN3, and HTT in the 1000 Genomes Project. Mov Disord 2020; 36:514-518. [PMID: 33159825 DOI: 10.1002/mds.28341] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/15/2020] [Accepted: 09/27/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Spinocerebellar ataxia types 1, 2, 3 and Huntington disease are neurodegenerative disorders caused by expanded CAG repeats. METHODS We performed an in-silico analysis of CAG repeats in ATXN1, ATXN2, ATXN3, and HTT using 30× whole-=genome sequencing data of 2504 samples from the 1000 Genomes Project. RESULTS Seven HTT-positive, 3 ATXN2-positive, 1 ATXN3-positive, and 6 possibly ATXN1-positive samples were identified. No correlation was found between the repeat sizes of the different genes. The distribution of CAG alleles varied by ethnicity. CONCLUSION Our results suggest that there may be asymptomatic small expanded repeats in almost 0.5% of these populations. © 2020 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Fulya Akçimen
- Department of Human Genetics, McGill University, Montréal, Québec, Canada.,Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Jay P Ross
- Department of Human Genetics, McGill University, Montréal, Québec, Canada.,Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Calwing Liao
- Department of Human Genetics, McGill University, Montréal, Québec, Canada.,Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Dan Spiegelman
- Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Patrick A Dion
- Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada.,Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| | - Guy A Rouleau
- Department of Human Genetics, McGill University, Montréal, Québec, Canada.,Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada.,Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
| |
Collapse
|
9
|
Wright GEB, Black HF, Collins JA, Gall-Duncan T, Caron NS, Pearson CE, Hayden MR. Interrupting sequence variants and age of onset in Huntington's disease: clinical implications and emerging therapies. Lancet Neurol 2020; 19:930-939. [PMID: 33098802 DOI: 10.1016/s1474-4422(20)30343-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/23/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Huntington's disease is a fatal neurodegenerative disorder that is caused by CAG-CAA repeat expansion, encoding polyglutamine, in the huntingtin (HTT) gene. Current age-of-clinical-onset prediction models for Huntington's disease are based on polyglutamine length and explain only a proportion of the variability in age of onset observed between patients. These length-based assays do not interrogate the underlying genetic variation, because known genetic variants in this region do not alter the protein coding sequence. Given that individuals with identical repeat lengths can present with Huntington's disease decades apart, the search for genetic modifiers of clinical age of onset has become an active area of research. RECENT DEVELOPMENTS Results from three independent genetic studies of Huntington's disease have shown that glutamine-encoding CAA variants that interrupt DNA CAG repeat tracts, but do not alter polyglutamine length or polyglutamine homogeneity, are associated with substantial differences in age of onset of Huntington's disease in carriers. A variant that results in the loss of CAA interruption is associated with early onset and is particularly relevant to individuals that carry alleles in the reduced penetrance range (ie, CAG 36-39). Approximately a third of clinically manifesting carriers of reduced penetrance alleles, defined by current diagnostics, carry this variant. Somatic repeat instability, modified by interrupted CAG tracts, is the most probable cause mediating this effect. This relationship is supported by genome-wide screens for disease modifiers, which have revealed the importance of DNA-repair genes in Huntington's disease (ie, FAN1, LIG1, MLH1, MSH3, PMS1, and PMS2). WHERE NEXT?: Focus needs to be placed on refining our understanding of the effect of the loss-of-interruption and duplication-of-interruption variants and other interrupting sequence variants on age of onset, and assessing their effect in disease-relevant brain tissues, as well as in diverse population groups, such as individuals from Africa and Asia. Diagnostic tests should be augmented or updated, since current tests do not assess the underlying DNA sequence variation, especially when assessing individuals that carry alleles in the reduced penetrance range. Future studies should explore somatic repeat instability and DNA repair as new therapeutic targets to modify age of onset in Huntington's disease and in other repeat-mediated disorders. Disease-modifying therapies could potentially be developed by therapeutically targeting these processes. Promising approaches include therapeutically targeting the expanded repeat or directly perturbing key DNA-repair genes (eg, with antisense oligonucleotides or small molecules). Targeting the CAG repeat directly with naphthyridine-azaquinolone, a compound that induces contractions, and altering the expression of MSH3, represent two viable therapeutic strategies. However, as a first step, the capability of such novel therapeutic approaches to delay clinical onset in animal models should be assessed.
Collapse
Affiliation(s)
- Galen E B Wright
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada; Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Hailey Findlay Black
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Jennifer A Collins
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Terence Gall-Duncan
- Program of Genetics and Genome Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Christopher E Pearson
- Program of Genetics and Genome Biology, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Vancouver, BC, Canada.
| |
Collapse
|