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Vegezzi E, Ishiura H, Bragg DC, Pellerin D, Magrinelli F, Currò R, Facchini S, Tucci A, Hardy J, Sharma N, Danzi MC, Zuchner S, Brais B, Reilly MM, Tsuji S, Houlden H, Cortese A. Neurological disorders caused by novel non-coding repeat expansions: clinical features and differential diagnosis. Lancet Neurol 2024; 23:725-739. [PMID: 38876750 DOI: 10.1016/s1474-4422(24)00167-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 06/16/2024]
Abstract
Nucleotide repeat expansions in the human genome are a well-known cause of neurological disease. In the past decade, advances in DNA sequencing technologies have led to a better understanding of the role of non-coding DNA, that is, the DNA that is not transcribed into proteins. These techniques have also enabled the identification of pathogenic non-coding repeat expansions that cause neurological disorders. Mounting evidence shows that adult patients with familial or sporadic presentations of epilepsy, cognitive dysfunction, myopathy, neuropathy, ataxia, or movement disorders can be carriers of non-coding repeat expansions. The description of the clinical, epidemiological, and molecular features of these recently identified non-coding repeat expansion disorders should guide clinicians in the diagnosis and management of these patients, and help in the genetic counselling for patients and their families.
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Affiliation(s)
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - D Cristopher Bragg
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - David Pellerin
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Riccardo Currò
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Stefano Facchini
- IRCCS Mondino Foundation, Pavia, Italy; Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Arianna Tucci
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; William Harvey Research Institute, Queen Mary University of London, London, UK
| | - John Hardy
- Department of Neurogedengerative Disease, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Matt C Danzi
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Stephan Zuchner
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, QC, Canada
| | - Mary M Reilly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Institute of Medical Genomics, International University of Health and Welfare, Chiba, Japan
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Andrea Cortese
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.
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Costa RG, Conceição A, Matos CA, Nóbrega C. The polyglutamine protein ATXN2: from its molecular functions to its involvement in disease. Cell Death Dis 2024; 15:415. [PMID: 38877004 PMCID: PMC11178924 DOI: 10.1038/s41419-024-06812-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
A CAG repeat sequence in the ATXN2 gene encodes a polyglutamine (polyQ) tract within the ataxin-2 (ATXN2) protein, showcasing a complex landscape of functions that have been progressively unveiled over recent decades. Despite significant progresses in the field, a comprehensive overview of the mechanisms governed by ATXN2 remains elusive. This multifaceted protein emerges as a key player in RNA metabolism, stress granules dynamics, endocytosis, calcium signaling, and the regulation of the circadian rhythm. The CAG overexpansion within the ATXN2 gene produces a protein with an extended poly(Q) tract, inducing consequential alterations in conformational dynamics which confer a toxic gain and/or partial loss of function. Although overexpanded ATXN2 is predominantly linked to spinocerebellar ataxia type 2 (SCA2), intermediate expansions are also implicated in amyotrophic lateral sclerosis (ALS) and parkinsonism. While the molecular intricacies await full elucidation, SCA2 presents ATXN2-associated pathological features, encompassing autophagy impairment, RNA-mediated toxicity, heightened oxidative stress, and disruption of calcium homeostasis. Presently, SCA2 remains incurable, with patients reliant on symptomatic and supportive treatments. In the pursuit of therapeutic solutions, various studies have explored avenues ranging from pharmacological drugs to advanced therapies, including cell or gene-based approaches. These endeavours aim to address the root causes or counteract distinct pathological features of SCA2. This review is intended to provide an updated compendium of ATXN2 functions, delineate the associated pathological mechanisms, and present current perspectives on the development of innovative therapeutic strategies.
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Affiliation(s)
- Rafael G Costa
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
| | - André Conceição
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
- Champalimaud Research Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Carlos A Matos
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
| | - Clévio Nóbrega
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
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Hayward B, Kumari D, Santra S, van Karnebeek CDM, van Kuilenburg ABP, Usdin K. All three MutL complexes are required for repeat expansion in a human stem cell model of CAG-repeat expansion mediated glutaminase deficiency. Sci Rep 2024; 14:13772. [PMID: 38877099 PMCID: PMC11178883 DOI: 10.1038/s41598-024-64480-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: 01/09/2024] [Accepted: 06/10/2024] [Indexed: 06/16/2024] Open
Abstract
The Repeat Expansion Diseases (REDs) arise from the expansion of a disease-specific short tandem repeat (STR). Different REDs differ with respect to the repeat involved, the cells that are most expansion prone and the extent of expansion. Furthermore, whether these diseases share a common expansion mechanism is unclear. To date, expansion has only been studied in a limited number of REDs. Here we report the first studies of the expansion mechanism in induced pluripotent stem cells derived from a patient with a form of the glutaminase deficiency disorder known as Global Developmental Delay, Progressive Ataxia, And Elevated Glutamine (GDPAG; OMIM# 618412) caused by the expansion of a CAG-STR in the 5' UTR of the glutaminase (GLS) gene. We show that alleles with as few as ~ 120 repeats show detectable expansions in culture despite relatively low levels of R-loops formed at this locus. Additionally, using a CRISPR-Cas9 knockout approach we show that PMS2 and MLH3, the constituents of MutLα and MutLγ, the 2 mammalian MutL complexes known to be involved in mismatch repair (MMR), are essential for expansion. Furthermore, PMS1, a component of a less well understood MutL complex, MutLβ, is also important, if not essential, for repeat expansion in these cells. Our results provide insights into the factors important for expansion and lend weight to the idea that, despite some differences, the same mechanism is responsible for expansion in many, if not all, REDs.
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Affiliation(s)
- Bruce Hayward
- Section On Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Daman Kumari
- Section On Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Saikat Santra
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, B15 2TG, UK
| | - Clara D M van Karnebeek
- Emma Center for Personalized Medicine, Departments of Pediatrics and Human Genetics, Amsterdam Gastro-Enterology Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- United for Metabolic Diseases, Amsterdam, The Netherlands
| | - André B P van Kuilenburg
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, The Netherlands
| | - Karen Usdin
- Section On Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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Suroliya V, Uppili B, Kumar M, Jha V, Srivastava AK, Faruq M. Identifying unstable CNG repeat loci in the human genome: a heuristic approach and implications for neurological disorders. Hum Genome Var 2024; 11:25. [PMID: 38871700 DOI: 10.1038/s41439-024-00281-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 05/08/2024] [Accepted: 05/14/2024] [Indexed: 06/15/2024] Open
Abstract
Tandem nucleotide repeat (TNR) expansions, particularly the CNG nucleotide configuration, are associated with a variety of neurodegenerative disorders. In this study, we aimed to identify novel unstable CNG repeat loci associated with the neurogenetic disorder spinocerebellar ataxia (SCA). Using a computational approach, 15,069 CNG repeat loci in the coding and noncoding regions of the human genome were identified. Based on the feature selection criteria (repeat length >10 and functional location of repeats), we selected 52 repeats for further analysis and evaluated the repeat length variability in 100 control subjects. A subset of 19 CNG loci observed to be highly variable in control subjects was selected for subsequent analysis in 100 individuals with SCA. The genes with these highly variable repeats also exhibited higher gene expression levels in the brain according to the tissue expression dataset (GTEx). No pathogenic expansion events were identified in patient samples, which is a limitation given the size of the patient group examined; however, these loci contain potential risk alleles for expandability. Recent studies have implicated GLS, RAI1, GIPC1, MED15, EP400, MEF2A, and CNKSR2 in neurological diseases, with GLS, GIPC1, MED15, RAI1, and MEF2A sharing the same repeat loci reported in this study. This finding validates the approach of evaluating repeat loci in different populations and their possible implications for human pathologies.
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Affiliation(s)
- Varun Suroliya
- Department of Neurology, All India Institute of Medical Sciences, Ansari Nagar, Delhi, 110020, India
| | - Bharathram Uppili
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India
- Academy for Scientific and Innovative Research, Ghaziabad, 201002, India
| | - Manish Kumar
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India
- Academy for Scientific and Innovative Research, Ghaziabad, 201002, India
| | - Vineet Jha
- Persistent LABS, Persistent Systems Ltd., Pune, Maharashtra, India
| | - Achal K Srivastava
- Department of Neurology, All India Institute of Medical Sciences, Ansari Nagar, Delhi, 110020, India
| | - Mohammed Faruq
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India.
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Watson S, Ngo KJ, Stevens HA, Wong DY, Kim J, Song Y, Han B, Hyun SI, Khang R, Ryu SW, Lee E, Seo G, Lee H, Lajonchere C, Fogel BL. Cross-Sectional Analysis of Exome Sequencing Diagnosis in Patients With Neurologic Phenotypes Facing Barriers to Clinical Testing. Neurol Genet 2024; 10:e200133. [PMID: 38617022 PMCID: PMC11010248 DOI: 10.1212/nxg.0000000000200133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/19/2024] [Indexed: 04/16/2024]
Abstract
Background and Objectives Exome sequencing (ES) demonstrates a 20-50 percent diagnostic yield for patients with a suspected monogenic neurologic disease. Despite the proven efficacy in achieving a diagnosis for such patients, multiple barriers for obtaining exome sequencing remain. This study set out to assess the efficacy of ES in patients with primary neurologic phenotypes who were appropriate candidates for testing but had been unable to pursue clinical testing. Methods A total of 297 patients were identified from the UCLA Clinical Neurogenomics Research Center Biobank, and ES was performed, including bioinformatic assessment of copy number variation and repeat expansions. Information regarding demographics, clinical indication for ES, and reason for not pursuing ES clinically were recorded. To assess diagnostic efficacy, variants were interpreted by a multidisciplinary team of clinicians, bioinformaticians, and genetic counselors in accordance with the American College of Medical Genetics and Genomics variant classification guidelines. We next examined the specific barriers to testing for these patients, including how frequently insurance-related barriers such as coverage denials and inadequate coverage of cost were obstacles to pursuing exome sequencing. Results The cohort primarily consisted of patients with sporadic conditions (n = 126, 42.4%) of adult-onset (n = 239, 80.5%). Cerebellar ataxia (n = 225, 75.8%) was the most common presenting neurologic phenotype. Our study found that in this population of mostly adult patients with primary neurologic phenotypes that were unable to pursue exome sequencing clinically, 47 (15.8%) had diagnostic results while an additional 24 patients (8.1%) had uncertain results. Of the 297 patients, 206 were initially recommended for clinical exome but 88 (42.7%) could not pursue ES because of insurance barriers, of whom 14 (15.9%) had diagnostic findings, representing 29.8% of all patients with diagnostic findings. In addition, the incorporation of bioinformatic repeat expansion testing was valuable, identifying a total of 8 pathogenic repeat expansions (17.0% of all diagnostic findings) including 3 of the common spinocerebellar ataxias and 2 patients with Huntington disease. Discussion These findings underscore the importance and value of clinical ES as a diagnostic tool for neurogenetic disease and highlight key barriers that prevent patients from receiving important clinical information with potential treatment and psychosocial implications for patients and family members.
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Affiliation(s)
- Sonya Watson
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Kathie J Ngo
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Hannah A Stevens
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Darice Y Wong
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Jihye Kim
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Yongjun Song
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Beomman Han
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Seong-In Hyun
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Rin Khang
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Seung Woo Ryu
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Eugene Lee
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Gohun Seo
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Hane Lee
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Clara Lajonchere
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
| | - Brent L Fogel
- From the Department of Neurology (S.W., K.J.N., H.A.S., D.Y.W., C.L., B.L.F.), the Clinical Neurogenomics Research Center (S.W., H.A.S., D.Y.W., C.L., B.L.F.), the Institute for Precision Health (S.W., C.L., B.L.F.), and the Department of Human Genetics (S.W., B.L.F.), David Geffen School of Medicine, University of California at Los Angeles (UCLA); 3billion, Inc. (J.K., Y.S., B.H., S.-I.H., R.K., S.W.R., E.L., G.S., H.L.)
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Zhang Y, Liu X, Li Z, Li H, Miao Z, Wan B, Xu X. Advances on the Mechanisms and Therapeutic Strategies in Non-coding CGG Repeat Expansion Diseases. Mol Neurobiol 2024:10.1007/s12035-024-04239-9. [PMID: 38780719 DOI: 10.1007/s12035-024-04239-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Non-coding CGG repeat expansions within the 5' untranslated region are implicated in a range of neurological disorders, including fragile X-associated tremor/ataxia syndrome, oculopharyngeal myopathy with leukodystrophy, and oculopharyngodistal myopathy. This review outlined the general characteristics of diseases associated with non-coding CGG repeat expansions, detailing their clinical manifestations and neuroimaging patterns, which often overlap and indicate shared pathophysiological traits. We summarized the underlying molecular mechanisms of these disorders, providing new insights into the roles that DNA, RNA, and toxic proteins play. Understanding these mechanisms is crucial for the development of targeted therapeutic strategies. These strategies include a range of approaches, such as antisense oligonucleotides, RNA interference, genomic DNA editing, small molecule interventions, and other treatments aimed at correcting the dysregulated processes inherent in these disorders. A deeper understanding of the shared mechanisms among non-coding CGG repeat expansion disorders may hold the potential to catalyze the development of innovative therapies, ultimately offering relief to individuals grappling with these debilitating neurological conditions.
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Affiliation(s)
- Yutong Zhang
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Xuan Liu
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Zeheng Li
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
| | - Hao Li
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China
- Department of Neurology, The Fourth Affiliated Hospital of Soochow University, Suzhou, 215124, China
| | - Zhigang Miao
- The Institute of Neuroscience, Soochow University, Suzhou City, China
| | - Bo Wan
- The Institute of Neuroscience, Soochow University, Suzhou City, China
| | - Xingshun Xu
- Departments of Neurology, The First Affiliated Hospital of Soochow University, Suzhou City, China.
- The Institute of Neuroscience, Soochow University, Suzhou City, China.
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, 215000, China.
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7
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Hayward B, Kumari D, Santra S, van Karnebeek CD, van Kuilenburg AB, Usdin K. All three MutL complexes are required for repeat expansion in a human stem cell model of CAG-repeat expansion mediated glutaminase deficiency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.26.573357. [PMID: 38260514 PMCID: PMC10802475 DOI: 10.1101/2023.12.26.573357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The Repeat Expansion Diseases (REDs) arise from the expansion of a disease-specific short tandem repeat (STR). Different REDs differ with respect to the repeat involved, the cells that are most expansion prone and the extent of expansion. Furthermore, whether these diseases share a common expansion mechanism is unclear. To date, expansion has only been studied in a limited number of REDs. Here we report the first studies of the expansion mechanism in induced pluripotent stem cells derived from a patient with a form of the glutaminase deficiency disorder known as Global Developmental Delay, Progressive Ataxia, And Elevated Glutamine (GDPAG; OMIM# 618412) caused by the expansion of a CAG-STR in the 5' UTR of the glutaminase (GLS) gene. We show that alleles with as few as ~120 repeats show detectable expansions in culture despite relatively low levels of R-loops formed at this locus. Additionally, using a CRISPR-Cas9 knockout approach we show that PMS2 and MLH3, the constituents of MutLα and MutLγ, the 2 mammalian MutL complexes known to be involved in mismatch repair (MMR), are essential for expansion. Furthermore, PMS1, a component of a less well understood MutL complex, MutLβ, is also important, if not essential, for repeat expansion in these cells. Our results provide insights into the factors important for expansion and lend weight to the idea that, despite some differences, the same mechanism is responsible for expansion in many, if not all, REDs.
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Affiliation(s)
- Bruce Hayward
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Daman Kumari
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Saikat Santra
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham B15 2TG, United Kingdom
| | - Clara D.M. van Karnebeek
- Amsterdam UMC location University of Amsterdam, Departments of Pediatrics and Human Genetics, Emma Center for Personalized Medicine, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
- United for Metabolic Diseases, The Netherlands
| | - André B.P. van Kuilenburg
- Amsterdam UMC location University of Amsterdam, Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, The Netherlands
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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8
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Garmendia J, Labayru G, Aliri J, López de Munain A, Sistiaga A. CNS involvement in myotonic dystrophy type 1: does sex play a role? Front Neurol 2024; 15:1399898. [PMID: 38784913 PMCID: PMC11111927 DOI: 10.3389/fneur.2024.1399898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Introduction Myotonic dystrophy type 1 (DM1) is a hereditary neuromuscular disorder affecting the central nervous system (CNS). Although sex differences have been explored in other neuromuscular disorders, research on this topic in DM1 remains limited. The present study aims to analyze sex differences (both the patient's and disease-transmitting parent's sex) with a focus on CNS outcomes. Methods Retrospective data from 146 non-congenital DM1 patients were analyzed, including clinical, molecular, neuropsychological, and neuroradiological data. Sex and inheritance pattern differences were analyzed using t-tests, and ANOVA analyses were conducted to address the interactions. Results Overall, no significant sex differences were observed except in certain cognitive domains. However, individuals with maternal inheritance showed larger CTG expansion size, lower estimated IQs, and poorer performance on visual memory, executive functions, and language domains than those with paternal inheritance. Notably, IQ performance was independently influenced by inheritance pattern and CTG expansion. Discussion This study is the first to delve into sex differences in DM1 with a focus on CNS outcomes. While the results revealed the absence of a sex-specific clinic-molecular profile, more substantial CNS differences were observed between patients with maternal and paternal inheritance patterns. The hypothetical existence of genomic imprinting and its potential mechanism are discussed. These findings hold potential implications for aiding clinical management by improving genetic counseling and predicting disease severity and prognosis.
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Affiliation(s)
- Joana Garmendia
- Department of Clinical and Health Psychology and Research Methodology, Psychology Faculty, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, Gipuzkoa, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institute Carlos III, Madrid, Spain
| | - Garazi Labayru
- Department of Clinical and Health Psychology and Research Methodology, Psychology Faculty, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, Gipuzkoa, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institute Carlos III, Madrid, Spain
- Neuroscience Area, Biogipuzkoa Health Research Institute, Donostia-San Sebastián, Gipuzkoa, Spain
| | - Jone Aliri
- Department of Clinical and Health Psychology and Research Methodology, Psychology Faculty, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, Gipuzkoa, Spain
| | - Adolfo López de Munain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institute Carlos III, Madrid, Spain
- Neuroscience Area, Biogipuzkoa Health Research Institute, Donostia-San Sebastián, Gipuzkoa, Spain
- Neurology Department, Donostia University Hospital, Donostia-San Sebastián, Gipuzkoa, Spain
- Neuroscience Department, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, Gipuzkoa, Spain
| | - Andone Sistiaga
- Department of Clinical and Health Psychology and Research Methodology, Psychology Faculty, University of the Basque Country (UPV/EHU), Donostia-San Sebastián, Gipuzkoa, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institute Carlos III, Madrid, Spain
- Neuroscience Area, Biogipuzkoa Health Research Institute, Donostia-San Sebastián, Gipuzkoa, Spain
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9
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Currò R, Dominik N, Facchini S, Vegezzi E, Sullivan R, Galassi Deforie V, Fernández-Eulate G, Traschütz A, Rossi S, Garibaldi M, Kwarciany M, Taroni F, Brusco A, Good JM, Cavalcanti F, Hammans S, Ravenscroft G, Roxburgh RH, Parolin Schnekenberg R, Rugginini B, Abati E, Manini A, Quartesan I, Ghia A, Lòpez de Munaìn A, Manganelli F, Kennerson M, Santorelli FM, Infante J, Marques W, Jokela M, Murphy SM, Mandich P, Fabrizi GM, Briani C, Gosal D, Pareyson D, Ferrari A, Prados F, Yousry T, Khurana V, Kuo SH, Miller J, Troakes C, Jaunmuktane Z, Giunti P, Hartmann A, Basak N, Synofzik M, Stojkovic T, Hadjivassiliou M, Reilly MM, Houlden H, Cortese A. Role of the repeat expansion size in predicting age of onset and severity in RFC1 disease. Brain 2024; 147:1887-1898. [PMID: 38193360 PMCID: PMC11068103 DOI: 10.1093/brain/awad436] [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: 10/06/2023] [Revised: 12/04/2023] [Accepted: 12/10/2023] [Indexed: 01/10/2024] Open
Abstract
RFC1 disease, caused by biallelic repeat expansion in RFC1, is clinically heterogeneous in terms of age of onset, disease progression and phenotype. We investigated the role of the repeat size in influencing clinical variables in RFC1 disease. We also assessed the presence and role of meiotic and somatic instability of the repeat. In this study, we identified 553 patients carrying biallelic RFC1 expansions and measured the repeat expansion size in 392 cases. Pearson's coefficient was calculated to assess the correlation between the repeat size and age at disease onset. A Cox model with robust cluster standard errors was adopted to describe the effect of repeat size on age at disease onset, on age at onset of each individual symptoms, and on disease progression. A quasi-Poisson regression model was used to analyse the relationship between phenotype and repeat size. We performed multivariate linear regression to assess the association of the repeat size with the degree of cerebellar atrophy. Meiotic stability was assessed by Southern blotting on first-degree relatives of 27 probands. Finally, somatic instability was investigated by optical genome mapping on cerebellar and frontal cortex and unaffected peripheral tissue from four post-mortem cases. A larger repeat size of both smaller and larger allele was associated with an earlier age at neurological onset [smaller allele hazard ratio (HR) = 2.06, P < 0.001; larger allele HR = 1.53, P < 0.001] and with a higher hazard of developing disabling symptoms, such as dysarthria or dysphagia (smaller allele HR = 3.40, P < 0.001; larger allele HR = 1.71, P = 0.002) or loss of independent walking (smaller allele HR = 2.78, P < 0.001; larger allele HR = 1.60; P < 0.001) earlier in disease course. Patients with more complex phenotypes carried larger expansions [smaller allele: complex neuropathy rate ratio (RR) = 1.30, P = 0.003; cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) RR = 1.34, P < 0.001; larger allele: complex neuropathy RR = 1.33, P = 0.008; CANVAS RR = 1.31, P = 0.009]. Furthermore, larger repeat expansions in the smaller allele were associated with more pronounced cerebellar vermis atrophy (lobules I-V β = -1.06, P < 0.001; lobules VI-VII β = -0.34, P = 0.005). The repeat did not show significant instability during vertical transmission and across different tissues and brain regions. RFC1 repeat size, particularly of the smaller allele, is one of the determinants of variability in RFC1 disease and represents a key prognostic factor to predict disease onset, phenotype and severity. Assessing the repeat size is warranted as part of the diagnostic test for RFC1 expansion.
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Affiliation(s)
- Riccardo Currò
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
| | - Natalia Dominik
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Stefano Facchini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
| | | | - Roisin Sullivan
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | | | - Gorka Fernández-Eulate
- Nord/Est/Ile-de-France Neuromuscular Reference Center, Institute of Myology, Pitié-Salpêtrière Hospital, APHP, 75013 Paris, France
| | - Andreas Traschütz
- Research Division ‘Translational Genomics of Neurodegenerative Diseases’, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, 72076 Tübingen, Germany
| | - Salvatore Rossi
- Dipartimento di Scienze dell'Invecchiamento, Neurologiche, Ortopediche e della Testa-Collo, UOC Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Facoltà di Medicina e Chirurgia, Dipartimento di Neuroscienze, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Matteo Garibaldi
- Neuromuscular and Rare Disease Center, Department of Neuroscience, Mental Health and Sensory Organs (NESMOS), Sant'Andrea Hospital, Sapienza University of Rome, 00189 Rome, Italy
| | - Mariusz Kwarciany
- Department of Adult Neurology, Medical University of Gdańsk, 80-952 Gdańsk, Poland
| | - Franco Taroni
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, 10124 Turin, Italy
| | - Jean-Marc Good
- Division of Genetic Medicine, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland
| | - Francesca Cavalcanti
- Institute for Biomedical Research and Innovation (IRIB), Italian National Research Council (CNR), 87050 Mangone, Italy
| | - Simon Hammans
- Wessex Neurological Centre, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Gianina Ravenscroft
- Neurogenetic Diseases Group, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedland, WA 6009, Australia
| | - Richard H Roxburgh
- Neurology Department, Auckland City Hospital, New Zealand and the Centre for Brain Research, University of Auckland, Auckland 1142, New Zealand
| | | | - Bianca Rugginini
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
| | - Elena Abati
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Arianna Manini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Ilaria Quartesan
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
| | - Arianna Ghia
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
| | - Adolfo Lòpez de Munaìn
- Neurology Department, Donostia University Hospital, University of the Basque Country-Osakidetza-CIBERNED-Biodonostia, 20014 Donostia-San Sebastián, Spain
| | - Fiore Manganelli
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, University of Naples Federico II, 80131 Naples, Italy
| | - Marina Kennerson
- Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2050, Australia
| | - Filippo Maria Santorelli
- IRCCS Stella Maris Foundation, Molecular Medicine for Neurodegenerative and Neuromuscular Disease Unit, 56128 Pisa, Italy
| | - Jon Infante
- University Hospital Marquès de Valdecilla-IDIVAL, University of Cantabria, 39008 Santander, Spain
| | - Wilson Marques
- Department of Neurology, School of Medicine of Ribeirão Preto, University of São Paulo, 2650 Ribeirão Preto, Brazil
| | - Manu Jokela
- Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, 33520 Tampere, Finland
- Neurocenter, Department of Neurology, Clinical Neurosciences, Turku University Hospital and University of Turku, 20014 Turku, Finland
| | - Sinéad M Murphy
- Department of Neurology, Tallaght University Hospital, D24 NR0A Dublin, Ireland
- Academic Unit of Neurology, Trinity College Dublin, D02 R590 Dublin, Ireland
| | - Paola Mandich
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
- IRCCS Ospedale Policlinico San Martino-UOC Genetica Medica, 16132 Genova, Italy
| | - Gian Maria Fabrizi
- Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Chiara Briani
- Department of Neurosciences, ERN Neuromuscular Unit, University of Padova, 35100 Padova, Italy
| | - David Gosal
- Manchester Centre for Clinical Neurosciences, Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust, Greater Manchester, M6 8HD, UK
| | - Davide Pareyson
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | | | - Ferran Prados
- Centre for Medical Image Computing (CMIC), Department of Medical Physics and Biomedical Engineering, University College London, London, WC1V 6LJ, UK
- NMR Research Unit, Institute of Neurology, University College London (UCL), London, WC1N 3BG, UK
- e-Health Centre, Universitat Oberta de Catalunya, 08018 Barcelona, Spain
| | - Tarek Yousry
- Neuroradiological Academic Unit, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Vikram Khurana
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - James Miller
- Department of Neurology, Royal Victoria Hospitals, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle, NE1 4LP, UK
| | - Claire Troakes
- London Neurodegenerative Diseases Brain Bank, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, SE21 8EA, UK
| | - Zane Jaunmuktane
- Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Paola Giunti
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Annette Hartmann
- Division of General Psychiatry, Medical University of Vienna, 1090 Vienna, Austria
| | - Nazli Basak
- Koç University, School of Medicine, Suna and İnan Kıraç Foundation, Neurodegeneration Research Laboratory (NDAL), Research Center for Translational Medicine, 34010 Istanbul, Turkey
| | - Matthis Synofzik
- Research Division ‘Translational Genomics of Neurodegenerative Diseases’, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, 72076 Tübingen, Germany
| | - Tanya Stojkovic
- Nord/Est/Ile-de-France Neuromuscular Reference Center, Institute of Myology, Pitié-Salpêtrière Hospital, APHP, 75013 Paris, France
| | - Marios Hadjivassiliou
- Academic Department of Neurosciences, Sheffield Teaching Hospitals NHS Trust and University of Sheffield, Sheffield, S10 2JF, UK
| | - Mary M Reilly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Andrea Cortese
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
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10
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Tandon S, Aggarwal P, Sarkar S. Polyglutamine disorders: Pathogenesis and potential drug interventions. Life Sci 2024; 344:122562. [PMID: 38492921 DOI: 10.1016/j.lfs.2024.122562] [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: 11/02/2023] [Revised: 02/27/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
Polyglutamine/poly(Q) diseases are a group nine hereditary neurodegenerative disorders caused due to abnormally expanded stretches of CAG trinucleotide in functionally distinct genes. All human poly(Q) diseases are characterized by the formation of microscopically discernable poly(Q) positive aggregates, the inclusion bodies. These toxic inclusion bodies are responsible for the impairment of several cellular pathways such as autophagy, transcription, cell death, etc., that culminate in disease manifestation. Although, these diseases remain largely without treatment, extensive research has generated mounting evidences that various events of poly(Q) pathogenesis can be developed as potential drug targets. The present review article briefly discusses the key events of disease pathogenesis, model system-based investigations that support the development of effective therapeutic interventions against pathogenesis of human poly(Q) disorders, and a comprehensive list of pharmacological and bioactive compounds that have been experimentally shown to alleviate poly(Q)-mediated neurotoxicity. Interestingly, due to the common cause of pathogenesis, all poly(Q) diseases share etiology, thus, findings from one disease can be potentially extrapolated to other poly(Q) diseases as well.
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Affiliation(s)
- Shweta Tandon
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Prerna Aggarwal
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India.
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Gumusgoz E, Kasiri S, Verma M, Wu J, Villarreal Acha D, Marriam U, Fyffe-Maricich S, Lin A, Chen X, Gray SJ, Minassian BA. CSTB gene replacement improves neuroinflammation, neurodegeneration and ataxia in murine type 1 progressive myoclonus epilepsy. Gene Ther 2024; 31:234-241. [PMID: 38135787 DOI: 10.1038/s41434-023-00433-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
EPM1 is the most common form of Progressive Myoclonus Epilepsy characterized by late-childhood onset, ever-worsening and disabling myoclonus, seizures, ataxia, psychiatric disease, and shortened lifespan. EPM1 is caused by expansions of a dodecamer repeat sequence in the promoter of CSTB (cystatin B), which dramatically reduces, but does not eliminate, gene expression. The relatively late onset and consistent presence of a minimal amount of protein product makes EPM1 a favorable target for gene replacement therapy. If treated early, these children's normally developed brains could be rescued from the neurodegeneration that otherwise follows, and their cross-reactive immunological material (CRIM) positive status greatly reduces transgene related toxicity. We performed a proof-of-concept CSTB gene replacement study in Cstb knockout mice by introducing full-length human CSTB driven by the CBh promoter packaged in AAV9 and administered at postnatal days 21 and 60. Mice were sacrificed at 2 or 9 months of age, respectively. We observed significant improvements in expression levels of neuroinflammatory pathway genes and cerebellar granule cell layer apoptosis, as well as amelioration of motor impairment. The data suggest that gene replacement is a promising therapeutic modality for EPM1 and could spare affected children and families the ravages of this otherwise severe neurodegenerative disease.
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Affiliation(s)
- Emrah Gumusgoz
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sahba Kasiri
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Mayank Verma
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Daniel Villarreal Acha
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ummay Marriam
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | | | - Xin Chen
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Steven J Gray
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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12
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Zhao T, Duan S, Li J, Zheng H, Liu C, Zhang H, Luo H, Xu Y. Mapping of repeat-associated non-AUG (RAN) translation knowledge: A bibliometric analysis. Heliyon 2024; 10:e29141. [PMID: 38628764 PMCID: PMC11019168 DOI: 10.1016/j.heliyon.2024.e29141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/08/2024] [Accepted: 04/01/2024] [Indexed: 04/19/2024] Open
Abstract
Over 50 genetic human disorders are attributed to the irregular expansion of microsatellites. These expanded microsatellite sequences can experience bidirectional transcription, leading to new reading frames. Beyond the standard AUG initiation or adjacent start codons, they are translated into proteins characterized by disease-causing amino acid repeats through repeat-associated non-AUG translation. Despite its significance, there's a discernible gap in comprehensive and objective articles on RAN translation. This study endeavors to evaluate and delineate the contemporary landscape and progress of RAN translation research via a bibliometric analysis. We sourced literature on RAN translation from the Web of Science Core Collection. Utilizing two bibliometric analysis tools, CiteSpace and VOSviewer, we gauged individual impacts and interactions by examining annual publications, journals, co-cited journals, countries/regions, institutions, authors, and co-cited authors. Following this, we assessed the co-occurrence and bursts of keywords and co-cited references to pinpoint research hotspots and trending in RAN translation. Between 2011 and 2022, 1317 authors across 359 institutions from 34 countries/regions contributed to 250 publications on RAN translation, spread across 118 academic journals. This article presents a systematic, objective, and comprehensive analysis of the current literature on RAN translation. Our findings emphasize that mechanisms related to C9orf72 ALS/FTD are pivotal topics in the realm of RAN translation, with cellular stress and the utilization of small molecule marking the trending research areas.
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Affiliation(s)
- Taiqi Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Suying Duan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Jiaqi Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Honglin Zheng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- The Academy of Medical Sciences of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Chenyang Liu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Hang Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Haiyang Luo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, Henan, China
| | - Yuming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, Henan, China
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13
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Pires GP, Fioresi VS, Canal D, Canal DC, Fernandes M, Brustolini OJB, de Avelar Carpinetti P, Ferreira A, da Silva Ferreira MF. Effects of trimer repeats on Psidium guajava L. gene expression and prospection of functional microsatellite markers. Sci Rep 2024; 14:9811. [PMID: 38684872 PMCID: PMC11059378 DOI: 10.1038/s41598-024-60417-8] [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: 11/19/2023] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
Most research on trinucleotide repeats (TRs) focuses on human diseases, with few on the impact of TR expansions on plant gene expression. This work investigates TRs' effect on global gene expression in Psidium guajava L., a plant species with widespread distribution and significant relevance in the food, pharmacology, and economics sectors. We analyzed TR-containing coding sequences in 1,107 transcripts from 2,256 genes across root, shoot, young leaf, old leaf, and flower bud tissues of the Brazilian guava cultivars Cortibel RM and Paluma. Structural analysis revealed TR sequences with small repeat numbers (5-9) starting with cytosine or guanine or containing these bases. Functional annotation indicated TR-containing genes' involvement in cellular structures and processes (especially cell membranes and signal recognition), stress response, and resistance. Gene expression analysis showed significant variation, with a subset of highly expressed genes in both cultivars. Differential expression highlighted numerous down-regulated genes in Cortibel RM tissues, but not in Paluma, suggesting interplay between tissues and cultivars. Among 72 differentially expressed genes with TRs, 24 form miRNAs, 13 encode transcription factors, and 11 are associated with transposable elements. In addition, a set of 20 SSR-annotated, transcribed, and differentially expressed genes with TRs was selected as phenotypic markers for Psidium guajava and, potentially for closely related species as well.
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Affiliation(s)
- Giovanna Pinto Pires
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Vinicius Sartori Fioresi
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Drielli Canal
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Dener Cezati Canal
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Miquéias Fernandes
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Otávio José Bernardes Brustolini
- Laboratório Nacional de Computação Científica (LNCC). Av. Getulio Vargas, 333, Petrópolis, Rio de Janeiro, Quitandinha, 25651-076, Brazil
| | - Paola de Avelar Carpinetti
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Adésio Ferreira
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil
| | - Marcia Flores da Silva Ferreira
- Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Universidade Federal Do Espírito Santo, Alto Universitário, s/n, Alegre, ES, 29500-000, Brazil.
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14
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Paul B, Siddaramappa S. Comparative analysis of the diversity of trinucleotide repeats in bacterial genomes. Genome 2024. [PMID: 38593473 DOI: 10.1139/gen-2023-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
The human gut is the most favorable niche for microbial populations, and few studies have explored the possibilities of horizontal gene transfer between host and pathogen. Trinucleotide repeat (TNR) expansion in humans can cause more than 40 neurodegenerative diseases. Further, TNRs are a type of microsatellite that resides on coding regions can contribute to the synthesis of homopolymeric amino acids. Hence, the present study aims to estimate the occurrence and diversity of TNRs in bacterial genomes available in the NCBI Genome database. Genome-wide analyses revealed that several bacterial genomes contain different types of uninterrupted TNRs. It was found that TNRs are abundant in the genomes of Alcaligenes faecalis, Mycoplasma gallisepticum, Mycoplasma genitalium, Sorangium cellulosum, and Thermus thermophilus. Interestingly, the genome of Bacillus thuringiensis strain YBT-1518 contained 169 uninterrupted ATT repeats. The genome of Leclercia adecarboxylata had 46 uninterrupted CAG repeats, which potentially translate into polyglutamine. In some instances, the TNRs were present in genes that potentially encode essential functions. Similar occurrences in human genes are known to cause genetic disorders. Further analysis of the occurrence of TNRs in bacterial genomes is likely to provide a better understanding of mismatch repair, genetic disorders, host-pathogen interaction, and homopolymeric amino acids.
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Affiliation(s)
- Bobby Paul
- Department of Bioinformatics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Shivakumara Siddaramappa
- Institute of Bioinformatics and Applied Biotechnology, Biotech Park, Electronic City, Bengaluru 560100, Karnataka, India
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15
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Levintov L, Vashisth H. Adenine Methylation Enhances the Conformational Flexibility of an RNA Hairpin Tetraloop. J Phys Chem B 2024; 128:3157-3166. [PMID: 38535997 PMCID: PMC11000223 DOI: 10.1021/acs.jpcb.4c00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/10/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
The N6-methyladenosine modification is one of the most abundant post-transcriptional modifications in ribonucleic acid (RNA) molecules. Using molecular dynamics simulations and alchemical free-energy calculations, we studied the structural and energetic implications of incorporating this modification in an adenine mononucleotide and an RNA hairpin structure. At the mononucleotide level, we found that the syn configuration is more favorable than the anti configuration by 2.05 ± 0.15 kcal/mol. The unfavorable effect of methylation was due to the steric overlap between the methyl group and a nitrogen atom in the purine ring. We then probed the effect of methylation in an RNA hairpin structure containing an AUCG tetraloop, which is recognized by a "reader" protein (YTHDC1) to promote transcriptional silencing of long noncoding RNAs. While methylation had no significant conformational effect on the hairpin stem, the methylated tetraloop showed enhanced conformational flexibility compared to the unmethylated tetraloop. The increased flexibility was associated with the outward flipping of two bases (A6 and U7) which formed stacking interactions with each other and with the C8 and G9 bases in the tetraloop, leading to a conformation similar to that in the RNA/reader protein complex. Therefore, methylation-induced conformational flexibility likely facilitates RNA recognition by the reader protein.
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Affiliation(s)
- Lev Levintov
- Department of Chemical Engineering
and Bioengineering, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Harish Vashisth
- Department of Chemical Engineering
and Bioengineering, University of New Hampshire, Durham, New Hampshire 03824, United States
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16
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Libonati L, Cambieri C, Colavito D, Moret F, D'Andrea E, Del Giudice E, Leon A, Inghilleri M, Ceccanti M. Genetics screening in an Italian cohort of patients with Amyotrophic Lateral Sclerosis: the importance of early testing and its implication. J Neurol 2024; 271:1921-1936. [PMID: 38112783 DOI: 10.1007/s00415-023-12142-x] [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: 09/06/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/21/2023]
Abstract
INTRODUCTION Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease with an elusive etiology. While environmental factors have been considered, familial ALS cases have raised the possibility of genetic involvement. This genetic connection is increasingly evident, even in patients with sporadic ALS. We allowed access to the genetic test to all patients attending our clinic to identify the prevalence and the role of genetic variants in the development of the disease and to identify patients with potentially treatable forms of the disease. MATERIALS AND METHODS 194 patients with probable or definite ALS, were enrolled. A comprehensive genetic testing was performed, including sequencing all exons of the SOD1 gene and testing for hexanucleotide intronic repeat expansions (G4C2) in the C9orf72 gene using fluorescent repeat-primed PCR (RP-PCR). Whole Exome NGS Sequencing (WES) was performed, followed by an in silico multigene panel targeting neuromuscular diseases, spastic paraplegia, and motor distal neuropathies. We conducted statistical analyses to compare different patient groups. RESULTS Clinically significant pathogenetic variants were detected in 14.43% of cases. The highest prevalence of pathogenetic variants was observed in fALS patients, but a substantial proportion of sALS patients also displayed at least one variant, either pathogenetic or of uncertain significance (VUS). The most observed pathogenetic variant was the expansion of the C9orf72 gene, which was associated with a shorter survival. SOD1 variants were found in 1.6% of fALS and 2.5% of sALS patients. DISCUSSION The study reveals a significant number of ALS patients carrying pathogenic or likely pathogenic variants, with a higher prevalence in familial ALS cases. The expansion of the C9orf72 gene emerges as the most common genetic cause of ALS, affecting familial and sporadic cases. Additionally, SOD1 variants are detected at an unexpectedly higher rate, even in patients without a familial history of ALS, underscoring the crucial role of genetic testing in treatment decisions and potential participation in clinical trials. We also investigated variants in genes such as TARDBP, FUS, NEK1, TBK1, and DNAJC7, shedding light on their potential involvement in ALS. These findings underscore the complexity of interpreting variants of uncertain significance (VUS) and their ethical implications in patient communication and genetic counseling for patients' relatives. CONCLUSION This study emphasizes the diverse genetic basis of ALS and advocates for integrating comprehensive genetic testing into diagnostic protocols. The evolving landscape of genetic therapies requires identifying all eligible patients transcending traditional familial boundaries. The presence of VUS highlights the multifaceted nature of ALS genetics, prompting further exploration of complex interactions among genetic variants, environmental factors, and disease development.
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Affiliation(s)
- Laura Libonati
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy.
| | - Chiara Cambieri
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy
| | - Davide Colavito
- R & I Genetics, C.So Stati Uniti 4int.F, 35127, Padua, Italy
| | - Federica Moret
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy
| | - Edoardo D'Andrea
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy
| | | | - Alberta Leon
- R & I Genetics, C.So Stati Uniti 4int.F, 35127, Padua, Italy
| | - Maurizio Inghilleri
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy
| | - Marco Ceccanti
- Department of Human Neurosciences, Rare Neuromuscular Diseases Centre, Sapienza University, Viale Dell'Università 30, 00185, Rome, Italy
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Oketch JW, Wain LV, Hollox EJ. A comparison of software for analysis of rare and common short tandem repeat (STR) variation using human genome sequences from clinical and population-based samples. PLoS One 2024; 19:e0300545. [PMID: 38558075 PMCID: PMC10984476 DOI: 10.1371/journal.pone.0300545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/27/2024] [Indexed: 04/04/2024] Open
Abstract
Short tandem repeat (STR) variation is an often overlooked source of variation between genomes. STRs comprise about 3% of the human genome and are highly polymorphic. Some cause Mendelian disease, and others affect gene expression. Their contribution to common disease is not well-understood, but recent software tools designed to genotype STRs using short read sequencing data will help address this. Here, we compare software that genotypes common STRs and rarer STR expansions genome-wide, with the aim of applying them to population-scale genomes. By using the Genome-In-A-Bottle (GIAB) consortium and 1000 Genomes Project short-read sequencing data, we compare performance in terms of sequence length, depth, computing resources needed, genotyping accuracy and number of STRs genotyped. To ensure broad applicability of our findings, we also measure genotyping performance against a set of genomes from clinical samples with known STR expansions, and a set of STRs commonly used for forensic identification. We find that HipSTR, ExpansionHunter and GangSTR perform well in genotyping common STRs, including the CODIS 13 core STRs used for forensic analysis. GangSTR and ExpansionHunter outperform HipSTR for genotyping call rate and memory usage. ExpansionHunter denovo (EHdn), STRling and GangSTR outperformed STRetch for detecting expanded STRs, and EHdn and STRling used considerably less processor time compared to GangSTR. Analysis on shared genomic sequence data provided by the GIAB consortium allows future performance comparisons of new software approaches on a common set of data, facilitating comparisons and allowing researchers to choose the best software that fulfils their needs.
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Affiliation(s)
- John W. Oketch
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Louise V. Wain
- Department of Population Health Sciences, University of Leicester, Leicester, United Kingdom
- National Institute for Health Research, Leicester Respiratory Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Edward J. Hollox
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
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18
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Stroik S, Luthman AJ, Ramsden DA. Templated insertions-DNA repair gets acrobatic. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024; 65 Suppl 1:82-89. [PMID: 37438951 PMCID: PMC10962320 DOI: 10.1002/em.22564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/28/2023] [Accepted: 07/07/2023] [Indexed: 07/14/2023]
Abstract
Deletions associated with the repair of DNA double-strand breaks is a source of genetic alternation and a recognized source of disease-causing mutagenesis. Theta-mediated end joining is a DNA repair mechanism, which guarantees deletions by its employment of microhomology (MH) alignment to facilitate end joining. A lesser-characterized templated insertion ability of this pathway, on the other hand, is associated with both deletion and insertion. This mechanism is characterized by at least one round of polymerase θ-mediated synthesis, which does not result in successful repair, followed by a subsequent round of polymerase engagement and synthesis that does lead to repair. Here we focus on the mechanisms by which polymerase θ introduces these insertions-direct, inverse, and a new class which we have termed strand switching. We observe this new class of templated insertions at multiple loci and across multiple species, often at a comparable frequency to those previously characterized. Templated insertion mutations are often enriched in cancer genomes and repeat expansion disorders. This repair mechanism thus contributes to disease-associated mutagenesis, and may plausibly even promote disease. Characterization of the types of polymerase θ-dependent insertions can provide new insight into these diseases and clinical promise for treatment.
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Affiliation(s)
- Susanna Stroik
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Adam J. Luthman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill NC, USA
| | - Dale A. Ramsden
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill NC, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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19
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Jensen TD, Ni B, Reuter CM, Gorzynski JE, Fazal S, Bonner D, Ungar RA, Goddard PC, Raja A, Ashley EA, Bernstein JA, Zuchner S, Greicius MD, Montgomery SB, Schatz MC, Wheeler MT, Battle A. Integration of transcriptomics and long-read genomics prioritizes structural variants in rare disease. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.03.22.24304565. [PMID: 38585781 PMCID: PMC10996727 DOI: 10.1101/2024.03.22.24304565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Rare structural variants (SVs) - insertions, deletions, and complex rearrangements - can cause Mendelian disease, yet they remain difficult to accurately detect and interpret. We sequenced and analyzed Oxford Nanopore long-read genomes of 68 individuals from the Undiagnosed Disease Network (UDN) with no previously identified diagnostic mutations from short-read sequencing. Using our optimized SV detection pipelines and 571 control long-read genomes, we detected 716 long-read rare (MAF < 0.01) SV alleles per genome on average, achieving a 2.4x increase from short-reads. To characterize the functional effects of rare SVs, we assessed their relationship with gene expression from blood or fibroblasts from the same individuals, and found that rare SVs overlapping enhancers were enriched (LOR = 0.46) near expression outliers. We also evaluated tandem repeat expansions (TREs) and found 14 rare TREs per genome; notably these TREs were also enriched near overexpression outliers. To prioritize candidate functional SVs, we developed Watershed-SV, a probabilistic model that integrates expression data with SV-specific genomic annotations, which significantly outperforms baseline models that don't incorporate expression data. Watershed-SV identified a median of eight high-confidence functional SVs per UDN genome. Notably, this included compound heterozygous deletions in FAM177A1 shared by two siblings, which were likely causal for a rare neurodevelopmental disorder. Our observations demonstrate the promise of integrating long-read sequencing with gene expression towards improving the prioritization of functional SVs and TREs in rare disease patients.
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20
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Potapenko A, Davidson JM, Lee A, Laird AS. The deubiquitinase function of ataxin-3 and its role in the pathogenesis of Machado-Joseph disease and other diseases. Biochem J 2024; 481:461-480. [PMID: 38497605 PMCID: PMC11088879 DOI: 10.1042/bcj20240017] [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: 01/18/2024] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 03/19/2024]
Abstract
Machado-Joseph disease (MJD) is a devastating and incurable neurodegenerative disease characterised by progressive ataxia, difficulty speaking and swallowing. Consequently, affected individuals ultimately become wheelchair dependent, require constant care, and face a shortened life expectancy. The monogenic cause of MJD is expansion of a trinucleotide (CAG) repeat region within the ATXN3 gene, which results in polyglutamine (polyQ) expansion within the resultant ataxin-3 protein. While it is well established that the ataxin-3 protein functions as a deubiquitinating (DUB) enzyme and is therefore critically involved in proteostasis, several unanswered questions remain regarding the impact of polyQ expansion in ataxin-3 on its DUB function. Here we review the current literature surrounding ataxin-3's DUB function, its DUB targets, and what is known regarding the impact of polyQ expansion on ataxin-3's DUB function. We also consider the potential neuroprotective effects of ataxin-3's DUB function, and the intersection of ataxin-3's role as a DUB enzyme and regulator of gene transcription. Ataxin-3 is the principal pathogenic protein in MJD and also appears to be involved in cancer. As aberrant deubiquitination has been linked to both neurodegeneration and cancer, a comprehensive understanding of ataxin-3's DUB function is important for elucidating potential therapeutic targets in these complex conditions. In this review, we aim to consolidate knowledge of ataxin-3 as a DUB and unveil areas for future research to aid therapeutic targeting of ataxin-3's DUB function for the treatment of MJD and other diseases.
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Affiliation(s)
- Anastasiya Potapenko
- Motor Neuron Disease Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Jennilee M. Davidson
- Motor Neuron Disease Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Albert Lee
- Motor Neuron Disease Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Angela S. Laird
- Motor Neuron Disease Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia
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21
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Zhang M. STRAS:a snakemake pipeline for genome-wide short tandem repeats annotation and score. Hum Genet 2024:10.1007/s00439-024-02662-5. [PMID: 38507015 DOI: 10.1007/s00439-024-02662-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/13/2024] [Indexed: 03/22/2024]
Abstract
High-throughput whole genome sequencing (WGS) is clinically used in finding single nucleotide variants and small indels. Several bioinformatics tools are developed to call short tandem repeats (STRs) copy numbers from WGS data, such as ExpansionHunter denovo, GangSTR and HipSTR. However, expansion disorders are rare and it is hard to find candidate expansions in single patient sequencing data with ~ 800,000 STRs calls. In this paper I describe a snakemake pipeline for genome-wide STRs Annotation and Score (STRAS) using a Random Forest (RF) model to predict pathogenicity. The predictor was validated by benchmark data from Clinvar and PUBMED. True positive rate was 93.8%. True negative rate was 98.0%.Precision was 98.6% and recall rate was 93.8%. F1-score was 0.961. Sensitivity was 93.8% and specificity was 99.6%. These results showed STRAS could be a useful tool for clinical researchers to find STR loci of interest and filter out neutral STRs. STRAS is freely available at https://github.com/fancheyu5/STRAS .
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Affiliation(s)
- Mengna Zhang
- Molecular Diagnosis Center, The Affiliated Hospital of Chengde Medical University, Chengde, 067000, China.
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22
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Wang Y, Chen Y, Gao J, Xie H, Guo Y, Yang J, Liu J, Chen Z, Li Q, Li M, Ren J, Wen L, Tang F. Mapping crossover events of mouse meiotic recombination by restriction fragment ligation-based Refresh-seq. Cell Discov 2024; 10:26. [PMID: 38443370 PMCID: PMC10915157 DOI: 10.1038/s41421-023-00638-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 12/11/2023] [Indexed: 03/07/2024] Open
Abstract
Single-cell whole-genome sequencing methods have undergone great improvements over the past decade. However, allele dropout, which means the inability to detect both alleles simultaneously in an individual diploid cell, largely restricts the application of these methods particularly for medical applications. Here, we develop a new single-cell whole-genome sequencing method based on third-generation sequencing (TGS) platform named Refresh-seq (restriction fragment ligation-based genome amplification and TGS). It is based on restriction endonuclease cutting and ligation strategy in which two alleles in an individual cell can be cut into equal fragments and tend to be amplified simultaneously. As a new single-cell long-read genome sequencing method, Refresh-seq features much lower allele dropout rate compared with SMOOTH-seq. Furthermore, we apply Refresh-seq to 688 sperm cells and 272 female haploid cells (secondary polar bodies and parthenogenetic oocytes) from F1 hybrid mice. We acquire high-resolution genetic map of mouse meiosis recombination at low sequencing depth and reveal the sexual dimorphism in meiotic crossovers. We also phase the structure variations (deletions and insertions) in sperm cells and female haploid cells with high precision. Refresh-seq shows great performance in screening aneuploid sperm cells and oocytes due to the low allele dropout rate and has great potential for medical applications such as preimplantation genetic diagnosis.
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Affiliation(s)
- Yan Wang
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Yijun Chen
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Junpeng Gao
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
- Emergency Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Haoling Xie
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Yuqing Guo
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Jingwei Yang
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Jun'e Liu
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Zonggui Chen
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
- Changping Laboratory, Beijing, China
| | - Qingqing Li
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Mengyao Li
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Jie Ren
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Lu Wen
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China
| | - Fuchou Tang
- Biomedical Pioneering Innovation Center, School of Life Sciences, Peking University, Beijing, China.
- Beijing Advanced Innovation Center for Genomics (ICG), Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing, China.
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- Changping Laboratory, Beijing, China.
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23
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Mätlik K, Baffuto M, Kus L, Deshmukh AL, Davis DA, Paul MR, Carroll TS, Caron MC, Masson JY, Pearson CE, Heintz N. Cell-type-specific CAG repeat expansions and toxicity of mutant Huntingtin in human striatum and cerebellum. Nat Genet 2024; 56:383-394. [PMID: 38291334 PMCID: PMC10937393 DOI: 10.1038/s41588-024-01653-6] [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: 06/21/2023] [Accepted: 12/28/2023] [Indexed: 02/01/2024]
Abstract
Brain region-specific degeneration and somatic expansions of the mutant Huntingtin (mHTT) CAG tract are key features of Huntington's disease (HD). However, the relationships among CAG expansions, death of specific cell types and molecular events associated with these processes are not established. Here, we used fluorescence-activated nuclear sorting (FANS) and deep molecular profiling to gain insight into the properties of cell types of the human striatum and cerebellum in HD and control donors. CAG expansions arise at mHTT in striatal medium spiny neurons (MSNs), cholinergic interneurons and cerebellar Purkinje neurons, and at mutant ATXN3 in MSNs from SCA3 donors. CAG expansions in MSNs are associated with higher levels of MSH2 and MSH3 (forming MutSβ), which can inhibit nucleolytic excision of CAG slip-outs by FAN1. Our data support a model in which CAG expansions are necessary but may not be sufficient for cell death and identify transcriptional changes associated with somatic CAG expansions and striatal toxicity.
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Affiliation(s)
- Kert Mätlik
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Matthew Baffuto
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Laura Kus
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA
| | - Amit Laxmikant Deshmukh
- Program of Genetics & Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - David A Davis
- Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Matthew R Paul
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - Thomas S Carroll
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - Marie-Christine Caron
- CHU de Québec Research Center, Oncology Division, Laval University Cancer Research Center, Quebec City, Quebec, Canada
| | - Jean-Yves Masson
- CHU de Québec Research Center, Oncology Division, Laval University Cancer Research Center, Quebec City, Quebec, Canada
| | - Christopher E Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, The Rockefeller University, New York, NY, USA.
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24
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Basavarajappa BS, Subbanna S. Unlocking the epigenetic symphony: histone acetylation's impact on neurobehavioral change in neurodegenerative disorders. Epigenomics 2024; 16:331-358. [PMID: 38321930 PMCID: PMC10910622 DOI: 10.2217/epi-2023-0428] [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: 12/04/2023] [Accepted: 01/23/2024] [Indexed: 02/08/2024] Open
Abstract
Recent genomics and epigenetic advances have empowered the exploration of DNA/RNA methylation and histone modifications crucial for gene expression in response to stress, aging and disease. Interest in understanding neuronal plasticity's epigenetic mechanisms, influencing brain rewiring amid development, aging and neurodegenerative disorders, continues to grow. Histone acetylation dysregulation, a commonality in diverse brain disorders, has become a therapeutic focus. Histone acetyltransferases and histone deacetylases have emerged as promising targets for neurodegenerative disorder treatment. This review delves into histone acetylation regulation, potential therapies and future perspectives for disorders like Alzheimer's, Parkinson's and Huntington's. Exploring genetic-environmental interplay through models and studies reveals molecular changes, behavioral insights and early intervention possibilities targeting the epigenome in at-risk individuals.
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Affiliation(s)
- Balapal S Basavarajappa
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
- Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, NY 10032, USA
- Department of Psychiatry, Columbia University Irving Medical Center, NY 10032, USA
- Department of Psychiatry, New York University Langone Medical Center, NY 10016, USA
| | - Shivakumar Subbanna
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
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25
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Dalene Skarping K, Arning L, Petersén Å, Nguyen HP, Gebre-Medhin S. Attenuated huntingtin gene CAG nucleotide repeat size in individuals with Lynch syndrome. Sci Rep 2024; 14:4300. [PMID: 38383663 PMCID: PMC10881568 DOI: 10.1038/s41598-024-54277-5] [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: 09/14/2023] [Accepted: 02/10/2024] [Indexed: 02/23/2024] Open
Abstract
DNA mismatch repair (MMR) is thought to contribute to the onset and progression of Huntington disease (HD) by promoting somatic expansion of the pathogenic CAG nucleotide repeat in the huntingtin gene (HTT). Here we have studied constitutional HTT CAG repeat size in two cohorts of individuals with Lynch syndrome (LS) carrying heterozygous loss-of-function variants in the MMR genes MLH1 (n = 12/60; Lund cohort/Bochum cohort, respectively), MSH2 (n = 15/88), MSH6 (n = 21/23), and controls (n = 19/559). The sum of CAG repeats for both HTT alleles in each individual was calculated due to unknown segregation with the LS allele. In the larger Bochum cohort, the sum of CAG repeats was lower in the MLH1 subgroup compared to controls (MLH1 35.40 CAG repeats ± 3.6 vs. controls 36.89 CAG repeats ± 4.5; p = 0.014). All LS genetic subgroups in the Bochum cohort displayed lower frequencies of unstable HTT intermediate alleles and lower HTT somatic CAG repeat expansion index values compared to controls. Collectively, our results indicate that MMR gene haploinsufficiency could have a restraining impact on constitutional HTT CAG repeat size and support the notion that the MMR pathway is a driver of nucleotide repeat expansion diseases.
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Affiliation(s)
- Karin Dalene Skarping
- Division of Clinical Genetics, Department of Laboratory Medicine, Lund University, Lund, Sweden
- Department of Clinical Genetics and Pathology, Office for Medical Service, 221 85, Lund, Sweden
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Larissa Arning
- Department of Human Genetics, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Åsa Petersén
- Translational Neuroendocrine Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Huu Phuc Nguyen
- Department of Human Genetics, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
| | - Samuel Gebre-Medhin
- Division of Clinical Genetics, Department of Laboratory Medicine, Lund University, Lund, Sweden.
- Department of Clinical Genetics and Pathology, Office for Medical Service, 221 85, Lund, Sweden.
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26
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Kumari D, Lokanga RA, McCann C, Ried T, Usdin K. The fragile X locus is prone to spontaneous DNA damage that is preferentially repaired by nonhomologous end-joining to preserve genome integrity. iScience 2024; 27:108814. [PMID: 38303711 PMCID: PMC10831274 DOI: 10.1016/j.isci.2024.108814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/26/2023] [Accepted: 01/02/2024] [Indexed: 02/03/2024] Open
Abstract
A long CGG-repeat tract in the FMR1 gene induces the epigenetic silencing that causes fragile X syndrome (FXS). Epigenetic changes include H4K20 trimethylation, a heterochromatic modification frequently implicated in transcriptional silencing. Here, we report that treatment with A-196, an inhibitor of SUV420H1/H2, the enzymes responsible for H4K20 di-/trimethylation, does not affect FMR1 transcription, but does result in increased chromosomal duplications. Increased duplications were also seen in FXS cells treated with SCR7, an inhibitor of Lig4, a ligase essential for NHEJ. Our study suggests that the fragile X (FX) locus is prone to spontaneous DNA damage that is normally repaired by NHEJ. We suggest that heterochromatinization of the FX allele may be triggered, at least in part, in response to this DNA damage.
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Affiliation(s)
- Daman Kumari
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rachel Adihe Lokanga
- Section of Cancer Genomics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cai McCann
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas Ried
- Section of Cancer Genomics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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27
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Anderson R, Das MR, Chang Y, Farenhem K, Schmitz CO, Jain A. CAG repeat expansions create splicing acceptor sites and produce aberrant repeat-containing RNAs. Mol Cell 2024; 84:702-714.e10. [PMID: 38295802 PMCID: PMC10923110 DOI: 10.1016/j.molcel.2024.01.006] [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: 08/20/2023] [Revised: 11/07/2023] [Accepted: 01/08/2024] [Indexed: 02/04/2024]
Abstract
Expansions of CAG trinucleotide repeats cause several rare neurodegenerative diseases. The disease-causing repeats are translated in multiple reading frames and without an identifiable initiation codon. The molecular mechanism of this repeat-associated non-AUG (RAN) translation is not known. We find that expanded CAG repeats create new splice acceptor sites. Splicing of proximal donors to the repeats produces unexpected repeat-containing transcripts. Upon splicing, depending on the sequences surrounding the donor, CAG repeats may become embedded in AUG-initiated open reading frames. Canonical AUG-initiated translation of these aberrant RNAs may account for proteins that have been attributed to RAN translation. Disruption of the relevant splice donors or the in-frame AUG initiation codons is sufficient to abrogate RAN translation. Our findings provide a molecular explanation for the abnormal translation products observed in CAG trinucleotide repeat expansion disorders and add to the repertoire of mechanisms by which repeat expansion mutations disrupt cellular functions.
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Affiliation(s)
- Rachel Anderson
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Michael R Das
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Yeonji Chang
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Kelsey Farenhem
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Cameron O Schmitz
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Ankur Jain
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA.
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28
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Shi Y, Cao C, Zeng Y, Ding Y, Chen L, Zheng F, Chen X, Zhou F, Yang X, Li J, Xu L, Xu G, Lin M, Ishiura H, Tsuji S, Wang N, Wang Z, Chen WJ, Yang K. CGG repeat expansion in LOC642361/NUTM2B-AS1 typically presents as oculopharyngodistal myopathy. J Genet Genomics 2024; 51:184-196. [PMID: 38159879 DOI: 10.1016/j.jgg.2023.12.009] [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: 09/26/2023] [Revised: 12/25/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy. However, since only three patients from a single family were reported, it remains unknown whether their clinicopathological features are typical for CGG repeat expansions in LOC642361/NUTM2B-AS1. Here, using repeat-primed-polymerase chain reaction and long-read sequencing, we identify 12 individuals from 3 unrelated families with CGG repeat expansions in LOC642361/NUTM2B-AS1, typically presenting with oculopharyngodistal myopathy. The CGG repeat expansions range from 161 to 669 repeat units. Most of the patients present with ptosis, restricted eye movements, dysphagia, dysarthria, and diffuse limb muscle weakness. Only one patient shows T2-weighted hyperintensity in the cerebellar white matter surrounding the deep cerebellar nuclei on brain magnetic resonance imaging. Muscle biopsies from three patients show a myopathic pattern and rimmed vacuoles. Analyses of muscle biopsies suggest that CGG repeat expansions in LOC642361/NUTM2B-AS1 may deleteriously affect aggrephagic capacity, suggesting that RNA toxicity and mitochondrial dysfunction may contribute to pathogenesis. Our study thus expands the phenotypic spectrum for the CGG repeat expansion of LOC642361/NUTM2B-AS1 and indicates that this genetic variant typically manifests as oculopharyngodistal myopathy with chronic myopathic changes with rimmed vacuoles and filamentous intranuclear inclusions in muscle fibers.
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Affiliation(s)
- Yan Shi
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Chunyan Cao
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; The First Affiliated Hospital, College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan 471000, China
| | - Yiheng Zeng
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Yuanliang Ding
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Long Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Fuze Zheng
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Xuejiao Chen
- Department of Neurology, Zhangzhou Municipal Hospital of Fujian Province and Zhangzhou Affiliated Hospital of Fujian Medical University, Zhangzhou, Fujian 363000, China
| | - Fanggui Zhou
- Department of Neurology, Jian'ou Municipal Hospital of Fujian Province, Jian'ou, Fujian 353100, China
| | - Xiefeng Yang
- Department of Radiology, First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Jinjing Li
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Liuqing Xu
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Guorong Xu
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Minting Lin
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Institute of Medical Genomics, International University of Health and Welfare, Chiba 286-0048, Japan
| | - Ning Wang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Zhiqiang Wang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China.
| | - Wan-Jin Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China.
| | - Kang Yang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China.
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29
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Miller L, Shorter J. Mo' m 1A, mo' problems. Cell Chem Biol 2024; 31:14-16. [PMID: 38242092 DOI: 10.1016/j.chembiol.2023.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 01/21/2024]
Abstract
CAG-repeat expansions underlie fatal neurodegenerative disorders. In a lodestar study published in a recent issue of Nature, Sun et al.1 identify a writer and eraser of N1-methyladenosine (m1A) modifications of CAG-repeat RNA. They establish that m1A modifications in CAG-repeat expanded RNA promote neurodegeneration and aberrant phase transitions of TDP-43. These findings suggest therapeutic strategies for CAG-repeat expansion disorders.
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Affiliation(s)
- Linamarie Miller
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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30
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Nasheuer HP, Meaney AM, Hulshoff T, Thiele I, Onwubiko NO. Replication Protein A, the Main Eukaryotic Single-Stranded DNA Binding Protein, a Focal Point in Cellular DNA Metabolism. Int J Mol Sci 2024; 25:588. [PMID: 38203759 PMCID: PMC10779431 DOI: 10.3390/ijms25010588] [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: 11/30/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024] Open
Abstract
Replication protein A (RPA) is a heterotrimeric protein complex and the main single-stranded DNA (ssDNA)-binding protein in eukaryotes. RPA has key functions in most of the DNA-associated metabolic pathways and DNA damage signalling. Its high affinity for ssDNA helps to stabilise ssDNA structures and protect the DNA sequence from nuclease attacks. RPA consists of multiple DNA-binding domains which are oligonucleotide/oligosaccharide-binding (OB)-folds that are responsible for DNA binding and interactions with proteins. These RPA-ssDNA and RPA-protein interactions are crucial for DNA replication, DNA repair, DNA damage signalling, and the conservation of the genetic information of cells. Proteins such as ATR use RPA to locate to regions of DNA damage for DNA damage signalling. The recruitment of nucleases and DNA exchange factors to sites of double-strand breaks are also an important RPA function to ensure effective DNA recombination to correct these DNA lesions. Due to its high affinity to ssDNA, RPA's removal from ssDNA is of central importance to allow these metabolic pathways to proceed, and processes to exchange RPA against downstream factors are established in all eukaryotes. These faceted and multi-layered functions of RPA as well as its role in a variety of human diseases will be discussed.
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Affiliation(s)
- Heinz Peter Nasheuer
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, Biochemistry, University of Galway, H91 TK33 Galway, Ireland
| | - Anna Marie Meaney
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, Biochemistry, University of Galway, H91 TK33 Galway, Ireland
| | - Timothy Hulshoff
- Molecular Systems Physiology Group, School of Biological and Chemical Sciences, University of Galway, H91 TK33 Galway, Ireland
| | - Ines Thiele
- Molecular Systems Physiology Group, School of Biological and Chemical Sciences, University of Galway, H91 TK33 Galway, Ireland
| | - Nichodemus O. Onwubiko
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, Biochemistry, University of Galway, H91 TK33 Galway, Ireland
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31
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Laspata N, Muoio D, Fouquerel E. Multifaceted Role of PARP1 in Maintaining Genome Stability Through Its Binding to Alternative DNA Structures. J Mol Biol 2024; 436:168207. [PMID: 37481154 DOI: 10.1016/j.jmb.2023.168207] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/28/2023] [Accepted: 07/12/2023] [Indexed: 07/24/2023]
Abstract
Alternative DNA structures that differ from the canonical B-form of DNA can arise from repetitive sequences and play beneficial roles in many cellular processes such as gene regulation and chromatin organization. However, they also threaten genomic stability in several ways including mutagenesis and collisions with replication and/or transcription machinery, which lead to genomic instability that is associated with human disease. Thus, the careful regulation of non-B-DNA structure formation and resolution is crucial for the maintenance of genome integrity. Several protein factors have been demonstrated to associate with alternative DNA structures to facilitate their removal, one of which is the ADP-ribose transferase (ART) PARP1 (also called ADP-ribosyltransferase diphtheria toxin-like 1 or ARTD1), a multifaceted DNA repair enzyme that recognizes single- and double-stranded DNA breaks and synthesizes chains of poly (ADP-ribose) (PAR) to recruit DNA repair proteins. It is now well appreciated that PARP1 recognizes several nucleic acid structures beyond DNA lesions, including stalled replication forks, DNA hairpins and cruciforms, R-loops, and DNA G-quadruplexes (G4 DNA). In this review, we summarize the current evidence of a direct association of PARP1 with each of these aforementioned alternative DNA structures, as well as discuss the role of PARP1 in the prevention of non-B-DNA structure-induced genetic instability. We will focus on the mechanisms of the recognition and binding by PARP1 to each alternative structure and the structure-based stimulation of PARP1 catalytic activity upon binding. Finally, we will discuss some of the outstanding gaps in the literature and offer speculative insight for questions that remain to be experimentally addressed.
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Affiliation(s)
- Natalie Laspata
- UPMC Hillman Cancer Center, University of Pittsburgh Cancer Institute, Department of Pharmacology and Chemical Biology, Pittsburgh, PA 15232, USA; Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Daniela Muoio
- UPMC Hillman Cancer Center, University of Pittsburgh Cancer Institute, Department of Pharmacology and Chemical Biology, Pittsburgh, PA 15232, USA
| | - Elise Fouquerel
- UPMC Hillman Cancer Center, University of Pittsburgh Cancer Institute, Department of Pharmacology and Chemical Biology, Pittsburgh, PA 15232, USA.
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32
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Kumar M, Tyagi N, Faruq M. The molecular mechanisms of spinocerebellar ataxias for DNA repeat expansion in disease. Emerg Top Life Sci 2023; 7:289-312. [PMID: 37668011 DOI: 10.1042/etls20230013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/01/2023] [Accepted: 08/16/2023] [Indexed: 09/06/2023]
Abstract
Spinocerebellar ataxias (SCAs) are a heterogenous group of neurodegenerative disorders which commonly inherited in an autosomal dominant manner. They cause muscle incoordination due to degeneration of the cerebellum and other parts of nervous system. Out of all the characterized (>50) SCAs, 14 SCAs are caused due to microsatellite repeat expansion mutations. Repeat expansions can result in toxic protein gain-of-function, protein loss-of-function, and/or RNA gain-of-function effects. The location and the nature of mutation modulate the underlying disease pathophysiology resulting in varying disease manifestations. Potential toxic effects of these mutations likely affect key major cellular processes such as transcriptional regulation, mitochondrial functioning, ion channel dysfunction and synaptic transmission. Involvement of several common pathways suggests interlinked function of genes implicated in the disease pathogenesis. A better understanding of the shared and distinct molecular pathogenic mechanisms in these diseases is required to develop targeted therapeutic tools and interventions for disease management. The prime focus of this review is to elaborate on how expanded 'CAG' repeats contribute to the common modes of neurotoxicity and their possible therapeutic targets in management of such devastating disorders.
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Affiliation(s)
- Manish Kumar
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Nishu Tyagi
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Mohammed Faruq
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
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33
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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.
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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
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Read JL, Davies KC, Thompson GC, Delatycki MB, Lockhart PJ. Challenges facing repeat expansion identification, characterisation, and the pathway to discovery. Emerg Top Life Sci 2023; 7:339-348. [PMID: 37888797 PMCID: PMC10754332 DOI: 10.1042/etls20230019] [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: 07/31/2023] [Revised: 10/06/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Tandem repeat DNA sequences constitute a significant proportion of the human genome. While previously considered to be functionally inert, these sequences are now broadly accepted as important contributors to genetic diversity. However, the polymorphic nature of these sequences can lead to expansion beyond a gene-specific threshold, causing disease. More than 50 pathogenic repeat expansions have been identified to date, many of which have been discovered in the last decade as a result of advances in sequencing technologies and associated bioinformatic tools. Commonly utilised diagnostic platforms including Sanger sequencing, capillary array electrophoresis, and Southern blot are generally low throughput and are often unable to accurately determine repeat size, composition, and epigenetic signature, which are important when characterising repeat expansions. The rapid advances in bioinformatic tools designed specifically to interrogate short-read sequencing and the development of long-read single molecule sequencing is enabling a new generation of high throughput testing for repeat expansion disorders. In this review, we discuss some of the challenges surrounding the identification and characterisation of disease-causing repeat expansions and the technological advances that are poised to translate the promise of genomic medicine to individuals and families affected by these disorders.
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Affiliation(s)
- Justin L Read
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Kayli C Davies
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Genevieve C Thompson
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Martin B Delatycki
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
- Victorian Clinical Genetics Services, Parkville, Victoria, Australia
| | - Paul J Lockhart
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
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Li J, Wang H, Yang W. Tandem MutSβ binding to long extruded DNA trinucleotide repeats underpins pathogenic expansions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571350. [PMID: 38168405 PMCID: PMC10760016 DOI: 10.1101/2023.12.12.571350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Expansion of trinucleotide repeats causes Huntington's disease, Fragile X syndrome and over twenty other monogenic disorders1. How mismatch repair protein MutSβ and large repeats of CNG (N=A, T, C or G) cooperate to drive the expansion is poorly understood. Contrary to expectations, we find that MutSβ prefers to bind the stem of an extruded (CNG) hairpin rather than the hairpin end or hairpin-duplex junction. Structural analyses reveal that in the presence of MutSβ, CNG repeats with N:N mismatches adopt a B form-like pseudo-duplex, with one or two CNG repeats slipped out forming uneven bubbles that partly mimic insertion-deletion loops of mismatched DNA2. When the extruded hairpin exceeds 40-45 repeats, it can be bound by three or more MutSβ molecules, which are resistant to ATP-dependent dissociation. We envision that such MutSβ-CNG complexes recruit MutLγ endonuclease to nick DNA and initiate the repeat expansion process3,4. To develop drugs against the expansion diseases, we have identified lead compounds that prevent MutSβ binding to CNG repeats but not to mismatched DNA.
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Affiliation(s)
- Jun Li
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
| | - Huaibin Wang
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
| | - Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
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Yu SY, Xi YL, Xu FQ, Zhang J, Liu YS. Application of long read sequencing in rare diseases: The longer, the better? Eur J Med Genet 2023; 66:104871. [PMID: 38832911 DOI: 10.1016/j.ejmg.2023.104871] [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: 08/18/2023] [Revised: 10/11/2023] [Accepted: 10/22/2023] [Indexed: 06/06/2024]
Abstract
Rare diseases encompass a diverse group of genetic disorders that affect a small proportion of the population. Identifying the underlying genetic causes of these conditions presents significant challenges due to their genetic heterogeneity and complexity. Conventional short-read sequencing (SRS) techniques have been widely used in diagnosing and investigating of rare diseases, with limitations due to the nature of short-read lengths. In recent years, long read sequencing (LRS) technologies have emerged as a valuable tool in overcoming these limitations. This minireview provides a concise overview of the applications of LRS in rare disease research and diagnosis, including the identification of disease-causing tandem repeat expansions, structural variations, and comprehensive analysis of pathogenic variants with LRS.
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Affiliation(s)
- Si-Yan Yu
- Department of Pediatric Laboratory, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, Jiangsu, China; The First School of Clinical Medicine, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yu-Lin Xi
- Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China
| | - Fu-Qiang Xu
- Department of Gynecology, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Jian Zhang
- Department of Medical Laboratory, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, Jiangsu, China.
| | - Yan-Shan Liu
- Department of Pediatric Laboratory, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, Jiangsu, China; Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China.
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Felício D, du Mérac TR, Amorim A, Martins S. Functional implications of paralog genes in polyglutamine spinocerebellar ataxias. Hum Genet 2023; 142:1651-1676. [PMID: 37845370 PMCID: PMC10676324 DOI: 10.1007/s00439-023-02607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023]
Abstract
Polyglutamine (polyQ) spinocerebellar ataxias (SCAs) comprise a group of autosomal dominant neurodegenerative disorders caused by (CAG/CAA)n expansions. The elongated stretches of adjacent glutamines alter the conformation of the native proteins inducing neurotoxicity, and subsequent motor and neurological symptoms. Although the etiology and neuropathology of most polyQ SCAs have been extensively studied, only a limited selection of therapies is available. Previous studies on SCA1 demonstrated that ATXN1L, a human duplicated gene of the disease-associated ATXN1, alleviated neuropathology in mice models. Other SCA-associated genes have paralogs (i.e., copies at different chromosomal locations derived from duplication of the parental gene), but their functional relevance and potential role in disease pathogenesis remain unexplored. Here, we review the protein homology, expression pattern, and molecular functions of paralogs in seven polyQ dominant ataxias-SCA1, SCA2, MJD/SCA3, SCA6, SCA7, SCA17, and DRPLA. Besides ATXN1L, we highlight ATXN2L, ATXN3L, CACNA1B, ATXN7L1, ATXN7L2, TBPL2, and RERE as promising functional candidates to play a role in the neuropathology of the respective SCA, along with the parental gene. Although most of these duplicates lack the (CAG/CAA)n region, if functionally redundant, they may compensate for a partial loss-of-function or dysfunction of the wild-type genes in SCAs. We aim to draw attention to the hypothesis that paralogs of disease-associated genes may underlie the complex neuropathology of dominant ataxias and potentiate new therapeutic strategies.
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Affiliation(s)
- Daniela Felício
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313, Porto, Portugal
| | - Tanguy Rubat du Mérac
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Faculty of Science, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - António Amorim
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal
| | - Sandra Martins
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal.
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Yang S, Wijegunawardana D, Sheth U, Veire AM, Salgado JMS, Agrawal M, Zhou J, Pereira JD, Gendron TF, Guo JU. Aberrant splicing exonizes C9ORF72 repeat expansion in ALS/FTD. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.13.566896. [PMID: 38014069 PMCID: PMC10680656 DOI: 10.1101/2023.11.13.566896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
A nucleotide repeat expansion (NRE) in the first annotated intron of the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). While C9 NRE-containing RNAs can be translated into several toxic dipeptide repeat proteins, how an intronic NRE can assess the translation machinery in the cytoplasm remains unclear. By capturing and sequencing NRE-containing RNAs from patient-derived cells, we found that C9 NRE was exonized by the usage of downstream 5' splice sites and exported from the nucleus in a variety of spliced mRNA isoforms. C9ORF72 aberrant splicing was substantially elevated in both C9 NRE + motor neurons and human brain tissues. Furthermore, NREs above the pathological threshold were sufficient to activate cryptic splice sites in reporter mRNAs. In summary, our results revealed a crucial and potentially widespread role of repeat-induced aberrant splicing in the biogenesis, localization, and translation of NRE-containing RNAs.
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Gambelli A, Ferrando A, Boncristiani C, Schoeftner S. Regulation and function of R-loops at repetitive elements. Biochimie 2023; 214:141-155. [PMID: 37619810 DOI: 10.1016/j.biochi.2023.08.013] [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: 05/05/2023] [Revised: 08/13/2023] [Accepted: 08/19/2023] [Indexed: 08/26/2023]
Abstract
R-loops are atypical, three-stranded nucleic acid structures that contain a stretch of RNA:DNA hybrids and an unpaired, single stranded DNA loop. R-loops are physiological relevant and can act as regulators of gene expression, chromatin structure, DNA damage repair and DNA replication. However, unscheduled and persistent R-loops are mutagenic and can mediate replication-transcription conflicts, leading to DNA damage and genome instability if left unchecked. Detailed transcriptome analysis unveiled that 85% of the human genome, including repetitive regions, hold transcriptional activity. This anticipates that R-loops management plays a central role for the regulation and integrity of genomes. This function is expected to have a particular relevance for repetitive sequences that make up to 75% of the human genome. Here, we review the impact of R-loops on the function and stability of repetitive regions such as centromeres, telomeres, rDNA arrays, transposable elements and triplet repeat expansions and discuss their relevance for associated pathological conditions.
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Affiliation(s)
- Alice Gambelli
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Alessandro Ferrando
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Chiara Boncristiani
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy
| | - Stefan Schoeftner
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, Via E. Weiss 2, 34127, Trieste, Italy.
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Anderson R, Das M, Chang Y, Farenhem K, Jain A. CAG repeat expansions create splicing acceptor sites and produce aberrant repeat-containing RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.16.562581. [PMID: 37904984 PMCID: PMC10614865 DOI: 10.1101/2023.10.16.562581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Expansions of CAG trinucleotide repeats cause several rare neurodegenerative diseases. The disease-causing repeats are translated in multiple reading frames, without an identifiable initiation codon. The molecular mechanism of this repeat-associated non-AUG (RAN) translation is not known. We find that expanded CAG repeats create new splice acceptor sites. Splicing of proximal donors to the repeats produces unexpected repeat-containing transcripts. Upon splicing, depending on the sequences surrounding the donor, CAG repeats may become embedded in AUG-initiated open reading frames. Canonical AUG-initiated translation of these aberrant RNAs accounts for proteins that are attributed to RAN translation. Disruption of the relevant splice donors or the in-frame AUG initiation codons is sufficient to abrogate RAN translation. Our findings provide a molecular explanation for the abnormal translation products observed in CAG trinucleotide repeat expansion disorders and add to the repertoire of mechanisms by which repeat expansion mutations disrupt cellular functions.
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Affiliation(s)
- Rachel Anderson
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Michael Das
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Yeonji Chang
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Kelsey Farenhem
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
| | - Ankur Jain
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, 31 Ames Street, Cambridge, MA 02139, USA
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Giménez-Bejarano A, Alegre-Cortés E, Yakhine-Diop SMS, Gómez-Suaga P, Fuentes JM. Mitochondrial Dysfunction in Repeat Expansion Diseases. Antioxidants (Basel) 2023; 12:1593. [PMID: 37627588 PMCID: PMC10451345 DOI: 10.3390/antiox12081593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/29/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Repeat expansion diseases are a group of neuromuscular and neurodegenerative disorders characterized by expansions of several successive repeated DNA sequences. Currently, more than 50 repeat expansion diseases have been described. These disorders involve diverse pathogenic mechanisms, including loss-of-function mechanisms, toxicity associated with repeat RNA, or repeat-associated non-ATG (RAN) products, resulting in impairments of cellular processes and damaged organelles. Mitochondria, double membrane organelles, play a crucial role in cell energy production, metabolic processes, calcium regulation, redox balance, and apoptosis regulation. Its dysfunction has been implicated in the pathogenesis of repeat expansion diseases. In this review, we provide an overview of the signaling pathways or proteins involved in mitochondrial functioning described in these disorders. The focus of this review will be on the analysis of published data related to three representative repeat expansion diseases: Huntington's disease, C9orf72-frontotemporal dementia/amyotrophic lateral sclerosis, and myotonic dystrophy type 1. We will discuss the common effects observed in all three repeat expansion disorders and their differences. Additionally, we will address the current gaps in knowledge and propose possible new lines of research. Importantly, this group of disorders exhibit alterations in mitochondrial dynamics and biogenesis, with specific proteins involved in these processes having been identified. Understanding the underlying mechanisms of mitochondrial alterations in these disorders can potentially lead to the development of neuroprotective strategies.
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Affiliation(s)
- Alberto Giménez-Bejarano
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Cáceres, Spain; (A.G.-B.); (E.A.-C.); (S.M.S.Y.-D.); (P.G.-S.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salus Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto de Investigación Biosanitaria de Extremadura (INUBE), 10003 Cáceres, Spain
| | - Eva Alegre-Cortés
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Cáceres, Spain; (A.G.-B.); (E.A.-C.); (S.M.S.Y.-D.); (P.G.-S.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salus Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto de Investigación Biosanitaria de Extremadura (INUBE), 10003 Cáceres, Spain
| | - Sokhna M. S. Yakhine-Diop
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Cáceres, Spain; (A.G.-B.); (E.A.-C.); (S.M.S.Y.-D.); (P.G.-S.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salus Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto de Investigación Biosanitaria de Extremadura (INUBE), 10003 Cáceres, Spain
| | - Patricia Gómez-Suaga
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Cáceres, Spain; (A.G.-B.); (E.A.-C.); (S.M.S.Y.-D.); (P.G.-S.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salus Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto de Investigación Biosanitaria de Extremadura (INUBE), 10003 Cáceres, Spain
| | - José M. Fuentes
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, 10003 Cáceres, Spain; (A.G.-B.); (E.A.-C.); (S.M.S.Y.-D.); (P.G.-S.)
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativa, Instituto de Salus Carlos III (CIBER-CIBERNED-ISCIII), 28029 Madrid, Spain
- Instituto de Investigación Biosanitaria de Extremadura (INUBE), 10003 Cáceres, Spain
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Nikom D, Zheng S. Alternative splicing in neurodegenerative disease and the promise of RNA therapies. Nat Rev Neurosci 2023; 24:457-473. [PMID: 37336982 DOI: 10.1038/s41583-023-00717-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
Alternative splicing generates a myriad of RNA products and protein isoforms of different functions from a single gene. Dysregulated alternative splicing has emerged as a new mechanism broadly implicated in the pathogenesis of neurodegenerative diseases such as Alzheimer disease, amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson disease and repeat expansion diseases. Understanding the mechanisms and functional outcomes of abnormal splicing in neurological disorders is vital in developing effective therapies to treat mis-splicing pathology. In this Review, we discuss emerging research and evidence of the roles of alternative splicing defects in major neurodegenerative diseases and summarize the latest advances in RNA-based therapeutic strategies to target these disorders.
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Affiliation(s)
- David Nikom
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, USA
- Center for RNA Biology and Medicine, University of California, Riverside, Riverside, CA, USA
| | - Sika Zheng
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, USA.
- Center for RNA Biology and Medicine, University of California, Riverside, Riverside, CA, USA.
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA, USA.
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43
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Linares AJ, Fogel BL. Late-onset hereditary ataxias with dementia. Curr Opin Neurol 2023; 36:324-334. [PMID: 37382141 PMCID: PMC10524827 DOI: 10.1097/wco.0000000000001170] [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] [Indexed: 06/30/2023]
Abstract
PURPOSE OF REVIEW Late-onset genetic cerebellar ataxias are clinically heterogenous with variable phenotypes. Several of these conditions are commonly associated with dementia. Recognition of the relationship between ataxia and dementia can guide clinical genetic evaluation. RECENT FINDINGS Spinocerebellar ataxias often present with variable phenotypes that may include dementia. Genomic studies have begun to identify links between incomplete penetrance and such variable phenotypes in certain hereditary ataxias. Recent studies evaluating the interaction of TBP repeat expansions and STUB1 sequence variants provide a framework to understand how genetic interactions influence disease penetrance and dementia risk in spinocerebellar ataxia types 17 and 48. Further advances in next generation sequencing methods will continue to improve diagnosis and create new insights into the expressivity of existing disorders. SUMMARY The late-onset hereditary ataxias are a clinically heterogenous group of disorders with complex presentations that can include cognitive impairment and/or dementia. Genetic evaluation of late-onset ataxia patients with dementia follows a systemic testing approach that often utilizes repeat expansion testing followed by next-generation sequencing. Advances in bioinformatics and genomics is improving both diagnostic evaluation and establishing a basis for phenotypic variability. Whole genome sequencing will likely replace exome sequencing as a more comprehensive means of routine testing.
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Affiliation(s)
- Anthony J. Linares
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095 USA
| | - Brent L. Fogel
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095 USA
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, 90095 USA
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Ahsan MU, Liu Q, Perdomo JE, Fang L, Wang K. A survey of algorithms for the detection of genomic structural variants from long-read sequencing data. Nat Methods 2023; 20:1143-1158. [PMID: 37386186 DOI: 10.1038/s41592-023-01932-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 05/31/2023] [Indexed: 07/01/2023]
Abstract
As long-read sequencing technologies are becoming increasingly popular, a number of methods have been developed for the discovery and analysis of structural variants (SVs) from long reads. Long reads enable detection of SVs that could not be previously detected from short-read sequencing, but computational methods must adapt to the unique challenges and opportunities presented by long-read sequencing. Here, we summarize over 50 long-read-based methods for SV detection, genotyping and visualization, and discuss how new telomere-to-telomere genome assemblies and pangenome efforts can improve the accuracy and drive the development of SV callers in the future.
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Affiliation(s)
- Mian Umair Ahsan
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Qian Liu
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jonathan Elliot Perdomo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- School of Biomedical Engineering, Drexel University, Philadelphia, PA, USA
| | - Li Fang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Genetics and Biomedical Informatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Kai Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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45
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Zhang S, Pei G, Li B, Li P, Lin Y. Abnormal phase separation of biomacromolecules in human diseases. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1133-1152. [PMID: 37475546 PMCID: PMC10423695 DOI: 10.3724/abbs.2023139] [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: 05/25/2023] [Accepted: 07/07/2023] [Indexed: 07/22/2023] Open
Abstract
Membrane-less organelles (MLOs) formed through liquid-liquid phase separation (LLPS) are associated with numerous important biological functions, but the abnormal phase separation will also dysregulate the physiological processes. Emerging evidence points to the importance of LLPS in human health and diseases. Nevertheless, despite recent advancements, our knowledge of the molecular relationship between LLPS and diseases is frequently incomplete. In this review, we outline our current understanding about how aberrant LLPS affects developmental disorders, tandem repeat disorders, cancers and viral infection. We also examine disease mechanisms driven by aberrant condensates, and highlight potential treatment approaches. This study seeks to expand our understanding of LLPS by providing a valuable new paradigm for understanding phase separation and human disorders, as well as to further translate our current knowledge regarding LLPS into therapeutic discoveries.
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Affiliation(s)
- Songhao Zhang
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
| | - Gaofeng Pei
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- Frontier Research Center for Biological StructureTsinghua UniversityBeijing100084China
| | - Boya Li
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
| | - Pilong Li
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- Frontier Research Center for Biological StructureTsinghua UniversityBeijing100084China
| | - Yi Lin
- State Key Laboratory of Membrane BiologyTsinghua University-Peking University Joint Centre for Life SciencesSchool of Life SciencesTsinghua UniversityBeijing100084China
- IDG/McGovern Institute for Brain Research at Tsinghua UniversityBeijing100084China
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46
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Magdy Mohamed Abdelaziz Barakat S, Sallehuddin R, Yuhaniz SS, R. Khairuddin RF, Mahmood Y. Genome assembly composition of the String "ACGT" array: a review of data structure accuracy and performance challenges. PeerJ Comput Sci 2023; 9:e1180. [PMID: 37547391 PMCID: PMC10403225 DOI: 10.7717/peerj-cs.1180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 04/27/2023] [Indexed: 08/08/2023]
Abstract
Background The development of sequencing technology increases the number of genomes being sequenced. However, obtaining a quality genome sequence remains a challenge in genome assembly by assembling a massive number of short strings (reads) with the presence of repetitive sequences (repeats). Computer algorithms for genome assembly construct the entire genome from reads in two approaches. The de novo approach concatenates the reads based on the exact match between their suffix-prefix (overlapping). Reference-guided approach orders the reads based on their offsets in a well-known reference genome (reads alignment). The presence of repeats extends the technical ambiguity, making the algorithm unable to distinguish the reads resulting in misassembly and affecting the assembly approach accuracy. On the other hand, the massive number of reads causes a big assembly performance challenge. Method The repeat identification method was introduced for misassembly by prior identification of repetitive sequences, creating a repeat knowledge base to reduce ambiguity during the assembly process, thus enhancing the accuracy of the assembled genome. Also, hybridization between assembly approaches resulted in a lower misassembly degree with the aid of the reference genome. The assembly performance is optimized through data structure indexing and parallelization. This article's primary aim and contribution are to support the researchers through an extensive review to ease other researchers' search for genome assembly studies. The study also, highlighted the most recent developments and limitations in genome assembly accuracy and performance optimization. Results Our findings show the limitations of the repeat identification methods available, which only allow to detect of specific lengths of the repeat, and may not perform well when various types of repeats are present in a genome. We also found that most of the hybrid assembly approaches, either starting with de novo or reference-guided, have some limitations in handling repetitive sequences as it is more computationally costly and time intensive. Although the hybrid approach was found to outperform individual assembly approaches, optimizing its performance remains a challenge. Also, the usage of parallelization in overlapping and reads alignment for genome assembly is yet to be fully implemented in the hybrid assembly approach. Conclusion We suggest combining multiple repeat identification methods to enhance the accuracy of identifying the repeats as an initial step to the hybrid assembly approach and combining genome indexing with parallelization for better optimization of its performance.
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Affiliation(s)
| | - Roselina Sallehuddin
- Computer Science, School of Computing, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
| | - Siti Sophiayati Yuhaniz
- Advanced Informatics Department, Razak Faculty of Technology and Informatics, Universiti Teknologi Malaysia, Kuala Lumpur, Kuala Lumpur, Malaysia
| | | | - Yasir Mahmood
- Faculty of Information Technology, The University of Lahore, Lahore, Lahore, Pakistan
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47
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Ibañez K, Jadhav B, Facchini S, Garg P, Zanovello M, Martin-Trujillo A, Gies SJ, Deforie VG, Gagliardi D, Hensman D, Moutsianas L, Shoai M, Caulfield MJ, Cortese A, Escott-Price V, Hardy J, Houlden H, Sharp AJ, Tucci A. POPULATION FREQUENCY OF REPEAT EXPANSIONS INDICATES INCREASED DISEASE PREVALENCE ESTIMATES ACROSS DIFFERENT POPULATIONS. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.03.23292162. [PMID: 37461547 PMCID: PMC10350132 DOI: 10.1101/2023.07.03.23292162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Repeat expansion disorders (REDs) are a devastating group of predominantly neurological diseases. Together they are common, affecting 1 in 3,000 people worldwide with population-specific differences. However, prevalence estimates of REDs are hampered by heterogeneous clinical presentation, variable geographic distributions, and technological limitations leading to under-ascertainment. Here, leveraging whole genome sequencing data from 82,176 individuals from different populations we found an overall carrier frequency of REDs of 1 in 340 individuals. Modelling disease prevalence using genetic data, age at onset and survival, we show that REDs are up to 3-fold more prevalent than currently reported figures. While some REDs are population-specific, e.g. Huntington's disease type 2, most REDs are represented in all broad genetic ancestries, including Africans and Asians, challenging the notion that some REDs are found only in European populations. These results have worldwide implications for local and global health communities in the diagnosis and management of REDs both at local and global levels.
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Affiliation(s)
- Kristina Ibañez
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Bharati Jadhav
- Department of Genetics and Genomic Sciences and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Stefano Facchini
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
- IRCCS Mondino Foundation, Pavia, Italy
| | - Paras Garg
- Department of Genetics and Genomic Sciences and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Matteo Zanovello
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - Alejandro Martin-Trujillo
- Department of Genetics and Genomic Sciences and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Scott J Gies
- Department of Genetics and Genomic Sciences and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | | | - Delia Gagliardi
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - Davina Hensman
- St George’s, University of London, London, SW17 0RE, UK
- Department of Neurodegenerative Disorders, Institute of Neurology, UCL, London, UK
| | | | - Maryam Shoai
- Department of Neurodegenerative Disorders, Institute of Neurology, UCL, London, UK
| | | | | | - Mark J Caulfield
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Andrea Cortese
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - Valentina Escott-Price
- Department of Psychological Medicine and Clinical Neuroscience, School of Medicine, Cardiff University, UK
- Dementia Research Institute, Cardiff University, UK
| | - John Hardy
- Department of Neurodegenerative Disorders, Institute of Neurology, UCL, London, UK
| | - Henry Houlden
- Department of Neurodegenerative Disorders, Institute of Neurology, UCL, London, UK
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Andrew J Sharp
- Department of Genetics and Genomic Sciences and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Arianna Tucci
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
- Department of Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
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48
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Arancibia-Opazo S, Contreras-Riquelme JS, Sánchez M, Cisternas-Olmedo M, Vidal RL, Martin AJM, Sáez MA. Transcriptional and Histone Acetylation Changes Associated with CRE Elements Expose Key Factors Governing the Regulatory Circuit in the Early Stage of Huntington's Disease Models. Int J Mol Sci 2023; 24:10848. [PMID: 37446028 DOI: 10.3390/ijms241310848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
Huntington's disease (HD) is a disorder caused by an abnormal expansion of trinucleotide CAG repeats within the huntingtin (Htt) gene. Under normal conditions, the CREB Binding Protein interacts with CREB elements and acetylates Lysine 27 of Histone 3 to direct the expression of several genes. However, mutant Htt causes depletion of CBP, which in turn induces altered histone acetylation patterns and transcriptional deregulation. Here, we have studied a differential expression analysis and H3K27ac variation in 4- and 6-week-old R6/2 mice as a model of juvenile HD. The analysis of differential gene expression and acetylation levels were integrated into Gene Regulatory Networks revealing key regulators involved in the altered transcription cascade. Our results show changes in acetylation and gene expression levels that are related to impaired neuronal development, and key regulators clearly defined in 6-week-old mice are proposed to drive the downstream regulatory cascade in HD. Here, we describe the first approach to determine the relationship among epigenetic changes in the early stages of HD. We determined the existence of changes in pre-symptomatic stages of HD as a starting point for early onset indicators of the progression of this disease.
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Affiliation(s)
- Sandra Arancibia-Opazo
- Chromatin, Epigenetic, and Neuroscience Laboratory, Centro de Genómica y Bioinformática, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago 8580745, Chile
- Programa de Doctorado en Genómica Integrativa, Vicerrectoría de Investigación, Universidad Mayor, Santiago 8580745, Chile
- Laboratorio de Redes Biológicas, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Universidad San Sebastián, Santiago 8580704, Chile
| | - J Sebastián Contreras-Riquelme
- Plant Genome Regulation Lab, Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370186, Chile
| | - Mario Sánchez
- Chromatin, Epigenetic, and Neuroscience Laboratory, Centro de Genómica y Bioinformática, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago 8580745, Chile
| | - Marisol Cisternas-Olmedo
- Centro de Biología Integrativa, Facultad de Ciencias, Universidad Mayor, Santiago 8580745, Chile
- Biomedical Neuroscience Institute, University of Chile, Santiago 8380455, Chile
- Center for Geroscience, Brain Health, and Metabolism, Santiago 8380453, Chile
| | - René L Vidal
- Centro de Biología Integrativa, Facultad de Ciencias, Universidad Mayor, Santiago 8580745, Chile
- Biomedical Neuroscience Institute, University of Chile, Santiago 8380455, Chile
- Center for Geroscience, Brain Health, and Metabolism, Santiago 8380453, Chile
- Escuela de Biotecnología, Facultad de Ciencias, Universidad Mayor, Santiago 8580745, Chile
| | - Alberto J M Martin
- Laboratorio de Redes Biológicas, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Universidad San Sebastián, Santiago 8580704, Chile
- Escuela de Ingeniería, Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Santiago 7500000, Chile
| | - Mauricio A Sáez
- Chromatin, Epigenetic, and Neuroscience Laboratory, Centro de Genómica y Bioinformática, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Santiago 8580745, Chile
- Centro de Oncología de Precisión, Facultad de Medicina Universidad Mayor, Santiago 7560908, Chile
- Laboratorio de Investigación en Salud de Precisión, Departamento de Procesos Diagnósticos y Evaluación, Facultad de Ciencias de la Salud, Universidad Católica de Temuco, Temuco 4813302, Chile
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Mätlik K, Baffuto M, Kus L, Deshmukh AL, Davis DA, Paul MR, Carroll TS, Caron MC, Masson JY, Pearson CE, Heintz N. Cell Type Specific CAG Repeat Expansions and Toxicity of Mutant Huntingtin in Human Striatum and Cerebellum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538082. [PMID: 37333326 PMCID: PMC10274669 DOI: 10.1101/2023.04.24.538082] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Brain region-specific degeneration and somatic expansions of the mutant Huntingtin (mHTT) CAG tract are key features of Huntington's disease (HD). However, the relationships between CAG expansions, death of specific cell types, and molecular events associated with these processes are not established. Here we employed fluorescence-activated nuclear sorting (FANS) and deep molecular profiling to gain insight into the properties of cell types of the human striatum and cerebellum in HD and control donors. CAG expansions arise in striatal medium spiny neurons (MSNs) and cholinergic interneurons, in cerebellar Purkinje neurons, and at mATXN3 in MSNs from SCA3 donors. CAG expansions in MSNs are associated with higher levels of MSH2 and MSH3 (forming MutSβ), which can inhibit nucleolytic excision of CAG slip-outs by FAN1 in a concentration-dependent manner. Our data indicate that ongoing CAG expansions are not sufficient for cell death, and identify transcriptional changes associated with somatic CAG expansions and striatal toxicity.
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50
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Katayama T, Takahashi K, Yahara O, Sawada J, Ishida KI, Asanome A, Endo H, Saito T, Hasebe N, Kishibe M, Kanno H, Ishiko S, Sone J. NOTCH2NLC mutation-positive neuronal intranuclear inclusion disease with retinal dystrophy: A case report and literature review. Medicine (Baltimore) 2023; 102:e33789. [PMID: 37171294 PMCID: PMC10174370 DOI: 10.1097/md.0000000000033789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
INTRODUCTION Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disorder that produces a broad spectrum of clinical conditions such as dementia, upper motor neuron involvement, extrapyramidal symptoms, and neuropathy. Some studies have reported ophthalmological conditions associated with the disease; however, the details of these conditions remain unclear. PATIENT CONCERNS We report a 63-year-old Japanese female with cognitive decline, blurred vision, photophobia, and color blindness at 52 years of age who was diagnosed with cone dystrophy. She also had anxiety, insomnia, depression, delusions, hallucinations, a wide-based gait with short steps, and urinary incontinence. DIAGNOSES, INTERVENTIONS, AND OUTCOMES Magnetic resonance imaging revealed diffuse cerebral white matter changes and subcortical hyperintensity on diffusion-weighted imaging. Skin biopsy showed p62-positive intranuclear inclusions in sweat glands. NOTCH2NLC gene analysis revealed abnormal GGC expansion; therefore, NIID was diagnosed. CONCLUSION NOTCH2NLC mutation-positive NIID may be associated with retinal dystrophy. Brain magnetic resonance imaging and skin biopsy are helpful diagnostic clues, and gene analysis is crucial for accurate diagnosis and appropriate management.
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Affiliation(s)
| | - Kae Takahashi
- Department of Neurology, Asahikawa City Hospital, Japan
| | - Osamu Yahara
- Department of Neurology, Asahikawa City Hospital, Japan
| | - Jun Sawada
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Ken-Ichi Ishida
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Asuka Asanome
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Hisako Endo
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Tsukasa Saito
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Naoyuki Hasebe
- Division of Neurology, First Department of Internal Medicine, Asahikawa Medical University, Japan
| | - Mari Kishibe
- Department of Dermatology, Asahikawa Medical University, Japan
| | - Harumi Kanno
- Department of Ophthalmology, Asahikawa City Hospital, Japan
| | - Satoshi Ishiko
- Department of Ophthalmology, Asahikawa Medical University, Japan
| | - Jun Sone
- Institute for Medical Science of Aging, Aichi Medical University, Japan
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