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Iruzubieta P, Damborenea A, Ioghen M, Bajew S, Fernandez-Torrón R, Töpf A, Herrero-Reiriz Á, Epure D, Vill K, Hernández-Laín A, Manterola M, Azkargorta M, Pikatza-Menoio O, Pérez-Fernandez L, García-Puga M, Gaina G, Bastian A, Streata I, Walter MC, Müller-Felber W, Thiele S, Moragón S, Bastida-Lertxundi N, López-Cortajarena A, Elortza F, Gereñu G, Alonso-Martin S, Straub V, de Sancho D, Teleanu R, López de Munain A, Blázquez L. Biallelic variants in SNUPN cause a limb girdle muscular dystrophy with myofibrillar-like features. Brain 2024; 147:2867-2883. [PMID: 38366623 PMCID: PMC11292911 DOI: 10.1093/brain/awae046] [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: 09/08/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 02/18/2024] Open
Abstract
Alterations in RNA-splicing are a molecular hallmark of several neurological diseases, including muscular dystrophies, where mutations in genes involved in RNA metabolism or characterized by alterations in RNA splicing have been described. Here, we present five patients from two unrelated families with a limb-girdle muscular dystrophy (LGMD) phenotype carrying a biallelic variant in SNUPN gene. Snurportin-1, the protein encoded by SNUPN, plays an important role in the nuclear transport of small nuclear ribonucleoproteins (snRNPs), essential components of the spliceosome. We combine deep phenotyping, including clinical features, histopathology and muscle MRI, with functional studies in patient-derived cells and muscle biopsies to demonstrate that variants in SNUPN are the cause of a new type of LGMD according to current definition. Moreover, an in vivo model in Drosophila melanogaster further supports the relevance of Snurportin-1 in muscle. SNUPN patients show a similar phenotype characterized by proximal weakness starting in childhood, restrictive respiratory dysfunction and prominent contractures, although inter-individual variability in terms of severity even in individuals from the same family was found. Muscle biopsy showed myofibrillar-like features consisting of myotilin deposits and Z-disc disorganization. MRI showed predominant impairment of paravertebral, vasti, sartorius, gracilis, peroneal and medial gastrocnemius muscles. Conservation and structural analyses of Snurportin-1 p.Ile309Ser variant suggest an effect in nuclear-cytosol snRNP trafficking. In patient-derived fibroblasts and muscle, cytoplasmic accumulation of snRNP components is observed, while total expression of Snurportin-1 and snRNPs remains unchanged, which demonstrates a functional impact of SNUPN variant in snRNP metabolism. Furthermore, RNA-splicing analysis in patients' muscle showed widespread splicing deregulation, in particular in genes relevant for muscle development and splicing factors that participate in the early steps of spliceosome assembly. In conclusion, we report that SNUPN variants are a new cause of limb girdle muscular dystrophy with specific clinical, histopathological and imaging features, supporting SNUPN as a new gene to be included in genetic testing of myopathies. These results further support the relevance of splicing-related proteins in muscle disorders.
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Affiliation(s)
- Pablo Iruzubieta
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Alberto Damborenea
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Mihaela Ioghen
- Clinical Neurosciences Department, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Paediatric Neurology, 020021 Bucharest, Romania
| | - Simon Bajew
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Roberto Fernandez-Torrón
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, NE4 5NR Newcastle Upon Tyne, UK
| | - Álvaro Herrero-Reiriz
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Diana Epure
- Department of Paediatric Neurology, Doctor Victor Gomoiu Children’s Hospital, 022102 Bucharest, Romania
| | - Katharina Vill
- Department of Pediatric Neurology and Developmental Medicine and LMU Center for Children with Medical Complexity, Dr. von Hauner Children’s Hospital, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Aurelio Hernández-Laín
- Neuropathology Unit, Department of Pathology, 12 de Octubre University Hospital, 28041 Madrid, Spain
- Department of Neuro-oncology, Instituto de Investigación Sanitaria imas12, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
- Universidad Complutense de Madrid, Facultad de Medicina, 28040 Madrid, Spain
| | - María Manterola
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Mikel Azkargorta
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Centre for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Oihane Pikatza-Menoio
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Laura Pérez-Fernandez
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), 20014 San Sebastián, Spain
| | - Mikel García-Puga
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Gisela Gaina
- Department of Cell Biology, Neurosciences and Experimental Myology, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Alexandra Bastian
- Department of Pathology, Colentina Clinical Hospital, 020125 Bucharest, Romania
| | - Ioana Streata
- Human Genomics Laboratory, Regional Centre of Medical Genetics, Craiova University of Medicine and Pharmacy, 200349 Dolj, Romania
| | - Maggie C Walter
- Friedrich Baur Institute at the Department of Neurology, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
| | - Wolfgang Müller-Felber
- Institute of Human Genetics, School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Simone Thiele
- Friedrich Baur Institute at the Department of Neurology, LMU University Hospital, Ludwig-Maximilians-University Munich, 80539 Munich, Germany
| | - Saioa Moragón
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
| | - Nerea Bastida-Lertxundi
- Department of Clinical Genetics, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
| | - Aitziber López-Cortajarena
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), 20014 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Felix Elortza
- Proteomics Platform, CIC bioGUNE, Basque Research and Technology Alliance (BRTA), 48160 Derio, Spain
- Centre for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Gorka Gereñu
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Sonia Alonso-Martin
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, NE4 5NR Newcastle Upon Tyne, UK
| | - David de Sancho
- Donostia International Physics Center, 20018 San Sebastián, Spain
- Faculty of Chemistry, University of the Basque Country, 20018 San Sebastián, Spain
| | - Raluca Teleanu
- Clinical Neurosciences Department, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Paediatric Neurology, 020021 Bucharest, Romania
| | - Adolfo López de Munain
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- Department of Neurology, Donostia University Hospital, Osakidetza Basque Health Service, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Faculty of Medicine, University of the Basque Country, 20014 San Sebastián, Spain
- Faculty of Medicine, University of Deusto, 48007 Bilbao, Spain
| | - Lorea Blázquez
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastián, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain
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2
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Endo Y, Groom L, Wang SM, Pannia E, Griffiths NW, Van Gennip JLM, Ciruna B, Laporte J, Dirksen RT, Dowling JJ. Two zebrafish cacna1s loss-of-function variants provide models of mild and severe CACNA1S-related myopathy. Hum Mol Genet 2024; 33:254-269. [PMID: 37930228 PMCID: PMC10800018 DOI: 10.1093/hmg/ddad178] [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: 07/03/2023] [Revised: 09/25/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023] Open
Abstract
CACNA1S-related myopathy, due to pathogenic variants in the CACNA1S gene, is a recently described congenital muscle disease. Disease associated variants result in loss of gene expression and/or reduction of Cav1.1 protein stability. There is an incomplete understanding of the underlying disease pathomechanisms and no effective therapies are currently available. A barrier to the study of this myopathy is the lack of a suitable animal model that phenocopies key aspects of the disease. To address this barrier, we generated knockouts of the two zebrafish CACNA1S paralogs, cacna1sa and cacna1sb. Double knockout fish exhibit severe weakness and early death, and are characterized by the absence of Cav1.1 α1 subunit expression, abnormal triad structure, and impaired excitation-contraction coupling, thus mirroring the severe form of human CACNA1S-related myopathy. A double mutant (cacna1sa homozygous, cacna1sb heterozygote) exhibits normal development, but displays reduced body size, abnormal facial structure, and cores on muscle pathologic examination, thus phenocopying the mild form of human CACNA1S-related myopathy. In summary, we generated and characterized the first cacna1s zebrafish loss-of-function mutants, and show them to be faithful models of severe and mild forms of human CACNA1S-related myopathy suitable for future mechanistic studies and therapy development.
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Affiliation(s)
- Yukari Endo
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - Sabrina M Wang
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Emanuela Pannia
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Zebrafish Genetics and Disease Models Core Facility, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Nigel W Griffiths
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Jenica L M Van Gennip
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Brian Ciruna
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Inserm U1258, Cnrs UMR7104, Université de Strasbourg, 1 Rue Laurent Fries, Illkirch 67400, France
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, United States
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
- Division of Neurology, Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada
- Department of Paediatrics, University of Toronto, 555 University Ave, Toronto, ON M5G 1X8, Canada
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3
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Nitschke L, Cooper TA. Combinatorial effects of ion channel mis-splicing as a cause of myopathy in myotonic dystrophy. J Clin Invest 2024; 134:e176089. [PMID: 38165037 PMCID: PMC10760967 DOI: 10.1172/jci176089] [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] [Indexed: 01/03/2024] Open
Abstract
Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder caused by an unstable expanded CTG repeat located in the 3'-UTR of the DM1 protein kinase (DMPK) gene. The pathogenic mechanism results in misregulated alternative splicing of hundreds of genes, creating the dilemma of establishing which genes contribute to the mechanism of DM1 skeletal muscle pathology. In this issue of the JCI, Cisco and colleagues systematically tested the combinatorial effects of DM1-relevant mis-splicing patterns in vivo and identified the synergistic effects of mis-spliced calcium and chloride channels as a major contributor to DM1 skeletal muscle impairment. The authors further demonstrated the therapeutic potential for calcium channel modulation to block the synergistic effects and rescue myopathy.
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Affiliation(s)
| | - Thomas A. Cooper
- Department of Pathology and Immunology
- Department of Integrative Physiology and Biophysics, and
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
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Cisco LA, Sipple MT, Edwards KM, Thornton CA, Lueck JD. Verapamil mitigates chloride and calcium bi-channelopathy in a myotonic dystrophy mouse model. J Clin Invest 2024; 134:e173576. [PMID: 38165038 PMCID: PMC10760957 DOI: 10.1172/jci173576] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/23/2023] [Indexed: 01/03/2024] Open
Abstract
Myotonic dystrophy type 1 (DM1) involves misregulated alternative splicing for specific genes. We used exon or nucleotide deletion to mimic altered splicing of genes central to muscle excitation-contraction coupling in mice. Mice with forced skipping of exon 29 in the CaV1.1 calcium channel combined with loss of ClC-1 chloride channel function displayed markedly reduced lifespan, whereas other combinations of splicing mimics did not affect survival. The Ca2+/Cl- bi-channelopathy mice exhibited myotonia, weakness, and impairment of mobility and respiration. Chronic administration of the calcium channel blocker verapamil rescued survival and improved force generation, myotonia, and respiratory function. These results suggest that Ca2+/Cl- bi-channelopathy contributes to muscle impairment in DM1 and is potentially mitigated by common clinically available calcium channel blockers.
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Affiliation(s)
| | | | | | - Charles A. Thornton
- Department of Neurology
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - John D. Lueck
- Department of Pharmacology and Physiology
- Department of Neurology
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
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5
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Nakamori M, Nakatani D, Sato T, Hasuike Y, Kon S, Saito T, Nakamura H, Takahashi MP, Hida E, Komaki H, Matsumura T, Takada H, Mochizuki H. Erythromycin for myotonic dystrophy type 1: a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial. EClinicalMedicine 2024; 67:102390. [PMID: 38314057 PMCID: PMC10837534 DOI: 10.1016/j.eclinm.2023.102390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/06/2023] [Accepted: 12/06/2023] [Indexed: 02/06/2024] Open
Abstract
Background Myotonic dystrophy type 1 (DM1) is a devastating multisystemic disorder caused by a CTG repeat expansion in the DMPK gene, which subsequently triggers toxic RNA expression and dysregulated splicing. In a preclinical study, we demonstrated that erythromycin reduces the toxicity of abnormal RNA and ameliorates the aberrant splicing and motor phenotype in DM1 model mice. Methods This multicentre, randomised, double-blind, placebo-controlled, phase 2 trial was conducted at three centres in Japan to translate preclinical findings into practical applications in patients with DM1 by evaluating the safety and efficacy of erythromycin. Between Nov 29, 2019, and Jan 20, 2022, a total of 30 adult patients with DM1 were enrolled and randomly assigned in a 1:2:2 ratio to receive either placebo or erythromycin at two daily doses (500 mg or 800 mg) for 24 weeks. The primary outcome included the safety and tolerability of erythromycin. The secondary efficacy measures included splicing biomarkers, 6-min walk test results, muscle strength, and serum creatinine kinase (CK) values. This trial is registered with the Japan Registry of Clinical Trials, jRCT2051190069. Findings Treatment-related gastrointestinal symptoms occurred more frequently in the erythromycin group, but all adverse events were mild to moderate and resolved spontaneously. No serious safety concerns were identified. The CK levels from baseline to week 24 decreased in the overall erythromycin group compared with the placebo group (mean change of -6.4 U/L [SD 149] vs +182.8 [SD 228]), although this difference was not statistically significant (p = 0.070). Statistically significant improvements in the overall erythromycin treated groups compared to placebo were seen for two of the eleven splicing biomarkers that were each evaluated in half of the trial sample. These were MBNL1 (p = 0.048) and CACNA1S (p = 0.042). Interpretation Erythromycin demonstrated favourable safety and tolerability profiles in patients with DM1. A well-powered phase 3 trial is needed to evaluate efficacy, building on the preliminary findings from this study. Funding Japan Agency for Medical Research and Development.
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Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Neurology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Daisaku Nakatani
- Medical Centre for Translational Research, Department of Medical Innovation, Osaka University Hospital, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tomoharu Sato
- Department of Biostatistics & Data Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yuhei Hasuike
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Seiko Kon
- Department of Neurology, NHO Aomori National Hospital, 155-1 Hirano, Namioka, Aomori, 038-1331, Japan
| | - Toshio Saito
- Department of Neurology, NHO Osaka Toneyama Medical Centre, 5-1-1 Toneyama, Toyonaka, Osaka, 560-8552, Japan
| | - Harumasa Nakamura
- Translational Medical Centre, National Centre of Neurology and Psychiatry, 4-1-1 Ogawahigashimachi, Kodaira, Tokyo, 187-8502, Japan
| | - Masanori P. Takahashi
- Department of Clinical Laboratory and Biomedical Sciences, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Eisuke Hida
- Department of Biostatistics & Data Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hirofumi Komaki
- Translational Medical Centre, National Centre of Neurology and Psychiatry, 4-1-1 Ogawahigashimachi, Kodaira, Tokyo, 187-8502, Japan
| | - Tsuyoshi Matsumura
- Department of Neurology, NHO Osaka Toneyama Medical Centre, 5-1-1 Toneyama, Toyonaka, Osaka, 560-8552, Japan
| | - Hiroto Takada
- Department of Neurology, NHO Aomori National Hospital, 155-1 Hirano, Namioka, Aomori, 038-1331, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Solovyeva EM, Utzinger S, Vissières A, Mitchelmore J, Ahrné E, Hermes E, Poetsch T, Ronco M, Bidinosti M, Merkl C, Serluca FC, Fessenden J, Naumann U, Voshol H, Meyer AS, Hoersch S. Integrative Proteogenomics for Differential Expression and Splicing Variation in a DM1 Mouse Model. Mol Cell Proteomics 2024; 23:100683. [PMID: 37993104 PMCID: PMC10770608 DOI: 10.1016/j.mcpro.2023.100683] [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: 07/31/2022] [Revised: 09/02/2023] [Accepted: 11/17/2023] [Indexed: 11/24/2023] Open
Abstract
Dysregulated mRNA splicing is involved in the pathogenesis of many diseases including cancer, neurodegenerative diseases, and muscular dystrophies such as myotonic dystrophy type 1 (DM1). Comprehensive assessment of dysregulated splicing on the transcriptome and proteome level has been methodologically challenging, and thus investigations have often been targeting only few genes. Here, we performed a large-scale coordinated transcriptomic and proteomic analysis to characterize a DM1 mouse model (HSALR) in comparison to wild type. Our integrative proteogenomics approach comprised gene- and splicing-level assessments for mRNAs and proteins. It recapitulated many known instances of aberrant mRNA splicing in DM1 and identified new ones. It enabled the design and targeting of splicing-specific peptides and confirmed the translation of known instances of aberrantly spliced disease-related genes (e.g., Atp2a1, Bin1, Ryr1), complemented by novel findings (Flnc and Ywhae). Comparative analysis of large-scale mRNA and protein expression data showed quantitative agreement of differentially expressed genes and splicing patterns between disease and wild type. We hence propose this work as a suitable blueprint for a robust and scalable integrative proteogenomic strategy geared toward advancing our understanding of splicing-based disorders. With such a strategy, splicing-based biomarker candidates emerge as an attractive and accessible option, as they can be efficiently asserted on the mRNA and protein level in coordinated fashion.
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Affiliation(s)
- Elizaveta M Solovyeva
- Research Informatics, Biomedical Research at Novartis, Basel, Switzerland; V.L. Talrose Institute for Energy Problems of Chemical Physics, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
| | - Stephan Utzinger
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | | | - Joanna Mitchelmore
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | - Erik Ahrné
- Discovery Sciences, Biomedical Research at Novartis, Basel, Switzerland
| | - Erwin Hermes
- Discovery Sciences, Biomedical Research at Novartis, Basel, Switzerland
| | - Tania Poetsch
- Discovery Sciences, Biomedical Research at Novartis, Basel, Switzerland
| | - Marie Ronco
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | - Michael Bidinosti
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | - Claudia Merkl
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | - Fabrizio C Serluca
- Research Informatics, Biomedical Research at Novartis, Cambridge, Massachusetts, USA
| | - James Fessenden
- Neurodegenerative Diseases, Biomedical Research at Novartis, Cambridge, Massachusetts, USA
| | - Ulrike Naumann
- Discovery Sciences, Biomedical Research at Novartis, Basel, Switzerland
| | - Hans Voshol
- Discovery Sciences, Biomedical Research at Novartis, Basel, Switzerland
| | - Angelika S Meyer
- Diseases of Aging and Regenerative Medicine, Biomedical Research at Novartis, Basel, Switzerland
| | - Sebastian Hoersch
- Research Informatics, Biomedical Research at Novartis, Basel, Switzerland.
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7
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Pierre M, Djemai M, Chapotte-Baldacci CA, Pouliot V, Puymirat J, Boutjdir M, Chahine M. Cardiac involvement in patient-specific induced pluripotent stem cells of myotonic dystrophy type 1: unveiling the impact of voltage-gated sodium channels. Front Physiol 2023; 14:1258318. [PMID: 37791351 PMCID: PMC10544896 DOI: 10.3389/fphys.2023.1258318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 08/28/2023] [Indexed: 10/05/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a genetic disorder that causes muscle weakness and myotonia. In DM1 patients, cardiac electrical manifestations include conduction defects and atrial fibrillation. DM1 results in the expansion of a CTG transcribed into CUG-containing transcripts that accumulate in the nucleus as RNA foci and alter the activity of several splicing regulators. The underlying pathological mechanism involves two key RNA-binding proteins (MBNL and CELF) with expanded CUG repeats that sequester MBNL and alter the activity of CELF resulting in spliceopathy and abnormal electrical activity. In the present study, we identified two DM1 patients with heart conduction abnormalities and characterized their hiPSC lines. Two differentiation protocols were used to investigate both the ventricular and the atrial electrophysiological aspects of DM1 and unveil the impact of the mutation on voltage-gated ion channels, electrical activity, and calcium homeostasis in DM1 cardiomyocytes derived from hiPSCs. Our analysis revealed the presence of molecular hallmarks of DM1, including the accumulation of RNA foci and sequestration of MBNL1 in DM1 hiPSC-CMs. We also observed mis-splicing of SCN5A and haploinsufficiency of DMPK. Furthermore, we conducted separate characterizations of atrial and ventricular electrical activity, conduction properties, and calcium homeostasis. Both DM1 cell lines exhibited reduced density of sodium and calcium currents, prolonged action potential duration, slower conduction velocity, and impaired calcium transient propagation in both ventricular and atrial cardiomyocytes. Notably, arrhythmogenic events were recorded, including both ventricular and atrial arrhythmias were observed in the two DM1 cell lines. These findings enhance our comprehension of the molecular mechanisms underlying DM1 and provide valuable insights into the pathophysiology of ventricular and atrial involvement.
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Affiliation(s)
| | | | | | | | - Jack Puymirat
- LOEX, CHU de Québec-Université Laval Research Center, Quebec City, QC, Canada
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, United States
- Departments of Cell Biology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, United States
- Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
| | - Mohamed Chahine
- CERVO Research Center, Quebec City, QC, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
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8
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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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9
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D'Ambrosio ES, Chuang K, David WS, Amato AA, Gonzalez-Perez P. Frequency and type of cancers in myotonic dystrophy: A retrospective cross-sectional study. Muscle Nerve 2023; 68:142-148. [PMID: 36790141 DOI: 10.1002/mus.27801] [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: 05/29/2022] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/16/2023]
Abstract
INTRODUCTION/AIMS Myotonic dystrophies (DMs) are autosomal dominant diseases in which expression of a mutant expanded repeat mRNA leads to abnormal splicing of downstream effector genes thought to be responsible for their multisystem involvement. Cancer risk and cancer-related deaths are increased in DM patients relative to the general population. We aimed at determining the frequency and type of cancers in both DM1 and DM2 vs a non-DM muscular dystrophy cohort. METHODS A retrospective, cross-sectional study was carried out on patients with genetically confirmed DM1, DM2, facioscapulohumeral muscular dystrophy (FSHD), and oculopharyngeal muscular dystrophy (OPMD) at our institutions from 2000 to 2020. RESULTS One hundred eighty-five DM1, 67 DM2, 187 FSHD, and 109 OPMD patients were included. Relative to non-DM, DM patients had an increased cancer risk that was independent of age and sex. Specifically, an increased risk of sex-related (ovarian) and non-sex-related (non-melanoma skin, urological, and hematological) cancers was observed in DM1 and DM2, respectively. The length of CTG repeat expansion was not associated with cancer occurrence in the DM1 group. DISCUSSION In addition to current consensus-based care recommendations, our findings prompt consideration of screening for skin, urological, and hematological cancers in DM2 patients, and screening of ovarian malignancies in DM1 female patients.
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Affiliation(s)
- Eleonora S D'Ambrosio
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Neurology, Brigham Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kathy Chuang
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - William S David
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Anthony A Amato
- Department of Neurology, Brigham Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Paloma Gonzalez-Perez
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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10
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Cisco LA, Sipple MT, Edwards KM, Thornton CA, Lueck JD. Combinatorial chloride and calcium channelopathy in myotonic dystrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.29.542752. [PMID: 37398406 PMCID: PMC10312834 DOI: 10.1101/2023.05.29.542752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Myotonic dystrophy type 1 (DM1) involves misregulated alternative splicing for specific genes. We used exon or nucleotide deletion to mimic altered splicing of genes central to muscle excitation-contraction coupling processes in mice. Mice with forced-skipping of exon 29 in CaV1.1 calcium channel combined with loss of ClC-1 chloride channel function showed a markedly reduced lifespan, whereas other combinations of splicing mimics did not affect survival. The Ca2+/Cl- bi-channelopathy mice exhibited myotonia, weakness, and impairment of mobility and respiration. Chronic administration of the calcium channel blocker verapamil rescued survival and improved force generation, myotonia, and respiratory function. These results suggest that Ca2+/Cl- bi-channelopathy contributes to muscle impairment in DM1 and is potentially mitigated by common clinically available calcium channel blockers.
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Affiliation(s)
- Lily A. Cisco
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Matthew T. Sipple
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Katherine M. Edwards
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Charles A. Thornton
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, Rochester, NY 14642, USA
| | - John D. Lueck
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, Rochester, NY 14642, USA
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11
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Bibollet H, Nguyen EL, Miranda DR, Ward CW, Voss AA, Schneider MF, Hernández‐Ochoa EO. Voltage sensor current, SR Ca 2+ release, and Ca 2+ channel current during trains of action potential-like depolarizations of skeletal muscle fibers. Physiol Rep 2023; 11:e15675. [PMID: 37147904 PMCID: PMC10163276 DOI: 10.14814/phy2.15675] [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: 02/02/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 05/07/2023] Open
Abstract
In skeletal muscle, CaV 1.1 serves as the voltage sensor for both excitation-contraction coupling (ECC) and L-type Ca2+ channel activation. We have recently adapted the technique of action potential (AP) voltage clamp (APVC) to monitor the current generated by the movement of intramembrane voltage sensors (IQ ) during single imposed transverse tubular AP-like depolarization waveforms (IQAP ). We now extend this procedure to monitoring IQAP , and Ca2+ currents during trains of tubular AP-like waveforms in adult murine skeletal muscle fibers, and compare them with the trajectories of APs and AP-induced Ca2+ release measured in other fibers using field stimulation and optical probes. The AP waveform remains relatively constant during brief trains (<1 sec) for propagating APs in non-V clamped fibers. Trains of 10 AP-like depolarizations at 10 Hz (900 ms), 50 Hz (180 ms), or 100 Hz (90 ms) did not alter IQAP amplitude or kinetics, consistent with previous findings in isolated muscle fibers where negligible charge immobilization occurred during 100 ms step depolarizations. Using field stimulation, Ca2+ release did exhibit a considerable decline from pulse to pulse during the train, also consistent with previous findings, indicating that the decline of Ca2+ release during a short train of APs is not correlated to modification of charge movement. Ca2+ currents during single or 10 Hz trains of AP-like depolarizations were hardly detectable, were minimal during 50 Hz trains, and became more evident during 100 Hz trains in some fibers. Our results verify predictions on the behavior of the ECC machinery in response to AP-like depolarizations and provide a direct demonstration that Ca2+ currents elicited by single AP-like waveforms are negligible, but can become more prominent in some fibers during short high-frequency train stimulation that elicits maximal isometric force.
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Affiliation(s)
- Hugo Bibollet
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Elton L. Nguyen
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Daniel R. Miranda
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Christopher W. Ward
- Department of OrthopedicsUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Andrew A. Voss
- Department of Biological SciencesWright State UniversityDaytonOhioUSA
| | - Martin F. Schneider
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Erick O. Hernández‐Ochoa
- Department of Biochemistry and Molecular BiologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
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12
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Hu N, Kim E, Antoury L, Wheeler TM. Correction of Clcn1 alternative splicing reverses muscle fiber type transition in mice with myotonic dystrophy. Nat Commun 2023; 14:1956. [PMID: 37029100 PMCID: PMC10082032 DOI: 10.1038/s41467-023-37619-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 03/21/2023] [Indexed: 04/09/2023] Open
Abstract
In myotonic dystrophy type 1 (DM1), deregulated alternative splicing of the muscle chloride channel Clcn1 causes myotonia, a delayed relaxation of muscles due to repetitive action potentials. The degree of weakness in adult DM1 is associated with increased frequency of oxidative muscle fibers. However, the mechanism for glycolytic-to-oxidative fiber type transition in DM1 and its relationship to myotonia are uncertain. Here we cross two mouse models of DM1 to create a double homozygous model that features progressive functional impairment, severe myotonia, and near absence of type 2B glycolytic fibers. Intramuscular injection of an antisense oligonucleotide for targeted skipping of Clcn1 exon 7a corrects Clcn1 alternative splicing, increases glycolytic 2B levels to ≥ 40% frequency, reduces muscle injury, and improves fiber hypertrophy relative to treatment with a control oligo. Our results demonstrate that fiber type transitions in DM1 result from myotonia and are reversible, and support the development of Clcn1-targeting therapies for DM1.
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Affiliation(s)
- Ningyan Hu
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eunjoo Kim
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Layal Antoury
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Thurman M Wheeler
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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13
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D’Ambrosio ES, Gonzalez-Perez P. Cancer and Myotonic Dystrophy. J Clin Med 2023; 12:1939. [PMID: 36902726 PMCID: PMC10004154 DOI: 10.3390/jcm12051939] [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: 02/07/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/05/2023] Open
Abstract
Myotonic dystrophy (DM) is the most common muscular dystrophy in adults. Dominantly inherited CTG and CCTG repeat expansions in DMPK and CNBP genes cause DM type 1 (DM1) and 2 (DM2), respectively. These genetic defects lead to the abnormal splicing of different mRNA transcripts, which are thought to be responsible for the multiorgan involvement of these diseases. In ours and others' experience, cancer frequency in patients with DM appears to be higher than in the general population or non-DM muscular dystrophy cohorts. There are no specific guidelines regarding malignancy screening in these patients, and the general consensus is that they should undergo the same cancer screening as the general population. Here, we review the main studies that investigated cancer risk (and cancer type) in DM cohorts and those that researched potential molecular mechanisms accounting for DM carcinogenesis. We propose some evaluations to be considered as malignancy screening in patients with DM, and we discuss DM susceptibility to general anesthesia and sedatives, which are often needed for the management of cancer. This review underscores the importance of monitoring the adherence of patients with DM to malignancy screenings and the need to design studies that determine whether they would benefit from a more intensified cancer screening than the general population.
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14
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Campiglio M, Dyrda A, Tuinte WE, Török E. Ca V1.1 Calcium Channel Signaling Complexes in Excitation-Contraction Coupling: Insights from Channelopathies. Handb Exp Pharmacol 2023; 279:3-39. [PMID: 36592225 DOI: 10.1007/164_2022_627] [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: 01/03/2023]
Abstract
In skeletal muscle, excitation-contraction (EC) coupling relies on the mechanical coupling between two ion channels: the L-type voltage-gated calcium channel (CaV1.1), located in the sarcolemma and functioning as the voltage sensor of EC coupling, and the ryanodine receptor 1 (RyR1), located on the sarcoplasmic reticulum serving as the calcium release channel. To this day, the molecular mechanism by which these two ion channels are linked remains elusive. However, recently, skeletal muscle EC coupling could be reconstituted in heterologous cells, revealing that only four proteins are essential for this process: CaV1.1, RyR1, and the cytosolic proteins CaVβ1a and STAC3. Due to the crucial role of these proteins in skeletal muscle EC coupling, any mutation that affects any one of these proteins can have devastating consequences, resulting in congenital myopathies and other pathologies.Here, we summarize the current knowledge concerning these four essential proteins and discuss the pathophysiology of the CaV1.1, RyR1, and STAC3-related skeletal muscle diseases with an emphasis on the molecular mechanisms. Being part of the same signalosome, mutations in different proteins often result in congenital myopathies with similar symptoms or even in the same disease.
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Affiliation(s)
- Marta Campiglio
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria.
| | - Agnieszka Dyrda
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Wietske E Tuinte
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Enikő Török
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
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15
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Peterson JAM, Cooper TA. Clinical and Molecular Insights into Gastrointestinal Dysfunction in Myotonic Dystrophy Types 1 & 2. Int J Mol Sci 2022; 23:ijms232314779. [PMID: 36499107 PMCID: PMC9737721 DOI: 10.3390/ijms232314779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Myotonic dystrophy (DM) is a highly variable, multisystemic disorder that clinically affects one in 8000 individuals. While research has predominantly focused on the symptoms and pathological mechanisms affecting striated muscle and brain, DM patient surveys have identified a high prevalence for gastrointestinal (GI) symptoms amongst affected individuals. Clinical studies have identified chronic and progressive dysfunction of the esophagus, stomach, liver and gallbladder, small and large intestine, and rectum and anal sphincters. Despite the high incidence of GI dysmotility in DM, little is known regarding the pathological mechanisms leading to GI dysfunction. In this review, we summarize results from clinical and molecular analyses of GI dysfunction in both genetic forms of DM, DM type 1 (DM1) and DM type 2 (DM2). Based on current knowledge of DM primary pathological mechanisms in other affected tissues and GI tissue studies, we suggest that misregulation of alternative splicing in smooth muscle resulting from the dysregulation of RNA binding proteins muscleblind-like and CUGBP-elav-like is likely to contribute to GI dysfunction in DM. We propose that a combinatorial approach using clinical and molecular analysis of DM GI tissues and model organisms that recapitulate DM GI manifestations will provide important insight into defects impacting DM GI motility.
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Affiliation(s)
- Janel A. M. Peterson
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor College of Medicine, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Thomas A. Cooper
- Baylor College of Medicine, Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor College of Medicine, Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor College of Medicine, Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence:
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16
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Tuinte WE, Török E, Mahlknecht I, Tuluc P, Flucher BE, Campiglio M. STAC3 determines the slow activation kinetics of Ca V 1.1 currents and inhibits its voltage-dependent inactivation. J Cell Physiol 2022; 237:4197-4214. [PMID: 36161458 DOI: 10.1002/jcp.30870] [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: 07/26/2022] [Accepted: 08/23/2022] [Indexed: 11/06/2022]
Abstract
The skeletal muscle CaV 1.1 channel functions as the voltage-sensor of excitation-contraction (EC) coupling. Recently, the adaptor protein STAC3 was found to be essential for both CaV 1.1 functional expression and EC coupling. Interestingly, STAC proteins were also reported to inhibit calcium-dependent inactivation (CDI) of L-type calcium channels (LTCC), an important negative feedback mechanism in calcium signaling. The same could not be demonstrated for CaV 1.1, as STAC3 is required for its functional expression. However, upon strong membrane depolarization, CaV 1.1 conducts calcium currents characterized by very slow kinetics of activation and inactivation. Therefore, we hypothesized that the negligible inactivation observed in CaV 1.1 currents reflects the inhibitory effect of STAC3. Here, we inserted a triple mutation in the linker region of STAC3 (ETLAAA), as the analogous mutation abolished the inhibitory effect of STAC2 on CDI of CaV 1.3 currents. When coexpressed in CaV 1.1/STAC3 double knockout myotubes, the mutant STAC3-ETLAAA failed to colocalize with CaV 1.1 in the sarcoplasmic reticulum/membrane junctions. However, combined patch-clamp and calcium recording experiments revealed that STAC3-ETLAAA supports CaV 1.1 functional expression and EC coupling, although at a reduced extent compared to wild-type STAC3. Importantly, STAC3-ETLAAA coexpression dramatically accelerated the kinetics of activation and inactivation of CaV 1.1 currents, suggesting that STAC3 determines the slow CaV 1.1 currents kinetics. To examine if STAC3 specifically inhibits the CDI of CaV 1.1 currents, we performed patch-clamp recordings using calcium and barium as charge carriers in HEK cells. While CaV 1.1 displayed negligible CDI with STAC3, this did not increase in the presence of STAC3-ETLAAA. On the contrary, our data demonstrate that STAC3 specifically inhibits the voltage-dependent inactivation (VDI) of CaV 1.1 currents. Altogether, these results designate STAC3 as a crucial determinant for the slow activation kinetics of CaV 1.1 currents and implicate STAC proteins as modulators of both components of inactivation of LTCC.
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Affiliation(s)
- Wietske E Tuinte
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Enikő Török
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Irene Mahlknecht
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Petronel Tuluc
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Bernhard E Flucher
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Marta Campiglio
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
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17
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El Ghaleb Y, Ortner NJ, Posch W, Fernández-Quintero ML, Tuinte WE, Monteleone S, Draheim HJ, Liedl KR, Wilflingseder D, Striessnig J, Tuluc P, Flucher BE, Campiglio M. Calcium current modulation by the γ1 subunit depends on alternative splicing of CaV1.1. J Gen Physiol 2022; 154:e202113028. [PMID: 35349630 PMCID: PMC9037348 DOI: 10.1085/jgp.202113028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 03/08/2022] [Indexed: 01/01/2023] Open
Abstract
The skeletal muscle voltage-gated calcium channel (CaV1.1) primarily functions as a voltage sensor for excitation-contraction coupling. Conversely, its ion-conducting function is modulated by multiple mechanisms within the pore-forming α1S subunit and the auxiliary α2δ-1 and γ1 subunits. In particular, developmentally regulated alternative splicing of exon 29, which inserts 19 amino acids in the extracellular IVS3-S4 loop of CaV1.1a, greatly reduces the current density and shifts the voltage dependence of activation to positive potentials outside the physiological range. We generated new HEK293 cell lines stably expressing α2δ-1, β3, and STAC3. When the adult (CaV1.1a) and embryonic (CaV1.1e) splice variants were expressed in these cells, the difference in the voltage dependence of activation observed in muscle cells was reproduced, but not the reduced current density of CaV1.1a. Only when we further coexpressed the γ1 subunit was the current density of CaV1.1a, but not that of CaV1.1e, reduced by >50%. In addition, γ1 caused a shift of the voltage dependence of inactivation to negative voltages in both variants. Thus, the current-reducing effect of γ1, unlike its effect on inactivation, is specifically dependent on the inclusion of exon 29 in CaV1.1a. Molecular structure modeling revealed several direct ionic interactions between residues in the IVS3-S4 loop and the γ1 subunit. However, substitution of these residues by alanine, individually or in combination, did not abolish the γ1-dependent reduction of current density, suggesting that structural rearrangements in CaV1.1a induced by inclusion of exon 29 may allosterically empower the γ1 subunit to exert its inhibitory action on CaV1.1 calcium currents.
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Affiliation(s)
- Yousra El Ghaleb
- Institute of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Nadine J. Ortner
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Wietske E. Tuinte
- Institute of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Stefania Monteleone
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Henning J. Draheim
- Boehringer Ingelheim Pharma GmbH & Co KG, CNS Research, Biberach an der Riss, Germany
| | - Klaus R. Liedl
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Petronel Tuluc
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Bernhard E. Flucher
- Institute of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Marta Campiglio
- Institute of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
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18
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Ravel-Chapuis A, Duchesne E, Jasmin BJ. Pharmacological and exercise-induced activation of AMPK as emerging therapies for myotonic dystrophy type 1 patients. J Physiol 2022; 600:3249-3264. [PMID: 35695045 DOI: 10.1113/jp282725] [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: 02/07/2022] [Accepted: 06/07/2022] [Indexed: 11/08/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic disorder with variable clinical features. Currently, there is no cure or effective treatment for DM1. The disease is caused by an expansion of CUG repeats in the 3' UTR of DMPK mRNAs. Mutant DMPK mRNAs accumulate in nuclei as RNA foci and trigger an imbalance in the level and localization of RNA-binding proteins causing the characteristic missplicing events that account for the varied DM1 symptoms, a disease mechanism referred to as RNA toxicity. In recent years, multiple signalling pathways have been identified as being aberrantly regulated in skeletal muscle in response to the CUG expansion, including AMPK, a sensor of energy status, as well as a master regulator of cellular energy homeostasis. Converging lines of evidence highlight the benefits of activating AMPK signalling pharmacologically on RNA toxicity, as well as on muscle histology and function, in preclinical DM1 models. Importantly, a clinical trial with metformin, an activator of AMPK, resulted in functional benefits in DM1 patients. In addition, exercise, a known AMPK activator, has shown promising effects on RNA toxicity and muscle function in DM1 mice. Finally, clinical trials involving moderate-intensity exercise also induced functional benefits for DM1 patients. Taken together, these studies clearly demonstrate the molecular, histological and functional benefits of AMPK activation and exercise-based interventions on the DM1 phenotype. Despite these advances, several key questions remain; in particular, the extent of the true implication of AMPK in the observed beneficial improvements, as well as how, mechanistically, activation of AMPK signalling improves the DM1 pathophysiology.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Elise Duchesne
- Département des sciences de la santé, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada.,Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Hôpital de Jonquière, QC, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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19
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Melzer W. From α1s splicing to γ1 function: A new twist in subunit modulation of the skeletal muscle L-type Ca2+ channel. J Gen Physiol 2022; 154:213270. [PMID: 35674662 PMCID: PMC9184848 DOI: 10.1085/jgp.202213182] [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] [Indexed: 11/20/2022] Open
Abstract
Melzer discusses a recent JGP study showing that alternative splicing of the skeletal muscle L-type calcium channel impacts on a modulatory effect of its γ subunit.
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Affiliation(s)
- Werner Melzer
- Institute of Applied Physiology, Ulm University, Ulm, Germany
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20
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Nakamori M, Shimizu H, Ogawa K, Hasuike Y, Nakajima T, Sakurai H, Araki T, Okada Y, Kakita A, Mochizuki H. Cell type-specific abnormalities of central nervous system in myotonic dystrophy type 1. Brain Commun 2022; 4:fcac154. [PMID: 35770133 PMCID: PMC9218787 DOI: 10.1093/braincomms/fcac154] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/13/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022] Open
Abstract
Myotonic dystrophy type 1 is a multisystem genetic disorder involving the muscle, heart and CNS. It is caused by toxic RNA transcription from expanded CTG repeats in the 3′-untranslated region of DMPK, leading to dysregulated splicing of various genes and multisystemic symptoms. Although aberrant splicing of several genes has been identified as the cause of some muscular symptoms, the pathogenesis of CNS symptoms prevalent in patients with myotonic dystrophy type 1 remains unelucidated, possibly due to a limitation in studying a diverse mixture of different cell types, including neuronal cells and glial cells. Previous studies revealed neuronal loss in the cortex, myelin loss in the white matter and the presence of axonal neuropathy in patients with myotonic dystrophy type 1. To elucidate the CNS pathogenesis, we investigated cell type-specific abnormalities in cortical neurons, white matter glial cells and spinal motor neurons via laser-capture microdissection. We observed that the CTG repeat instability and cytosine–phosphate–guanine (CpG) methylation status varied among the CNS cell lineages; cortical neurons had more unstable and longer repeats with higher CpG methylation than white matter glial cells, and spinal motor neurons had more stable repeats with lower methylation status. We also identified splicing abnormalities in each CNS cell lineage, such as DLGAP1 in white matter glial cells and CAMKK2 in spinal motor neurons. Furthermore, we demonstrated that aberrant splicing of CAMKK2 is associated with abnormal neurite morphology in myotonic dystrophy type 1 motor neurons. Our laser-capture microdissection-based study revealed cell type-dependent genetic, epigenetic and splicing abnormalities in myotonic dystrophy type 1 CNS, indicating the significant potential of cell type-specific analysis in elucidating the CNS pathogenesis.
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Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
- Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University , 1-1 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Hiroshi Shimizu
- Department of Pathology, Brain Research Institute, Niigata University , 1-757 Asahimachi, Chuo-ku, Niigata 951-8585 , Japan
| | - Kotaro Ogawa
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
- Department of Statistical Genetics, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Yuhei Hasuike
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Takashi Nakajima
- Department of Neurology, National Hospital Organization Niigata National Hospital , 3-52 Akasakamachi, Kashiwazaki, Niigata 945-8585 , Japan
| | - Hidetoshi Sakurai
- Center for iPS Cell Research and Application (CiRA), Kyoto University , 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 , Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry , 4-1-1 Ogawahigashimachi, Kodaira, Tokyo 187-8502 , Japan
| | - Yukinori Okada
- Department of Statistical Genetics, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University , 1-757 Asahimachi, Chuo-ku, Niigata 951-8585 , Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
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21
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Dobrowolny G, Scicchitano BM. The Role of Skeletal Muscle in Neuromuscular Diseases: From Cellular and Molecular Players to Therapeutic Interventions. Cells 2022; 11:cells11071207. [PMID: 35406771 PMCID: PMC8997919 DOI: 10.3390/cells11071207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/05/2023] Open
Affiliation(s)
- Gabriella Dobrowolny
- Laboratory Affiliated to Istituto Pasteur Italia—Fondazione Cenci Bolognetti, DAHFMO-Unità di Istologia ed Embriologia Medica, Sapienza Università di Roma, 00161 Roma, Italy
- Correspondence: (G.D.); (B.M.S.)
| | - Bianca Maria Scicchitano
- Sezione di Istologia ed Embriologia, Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Roma, Italy
- Correspondence: (G.D.); (B.M.S.)
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22
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Hinkle ER, Wiedner HJ, Torres EV, Jackson M, Black AJ, Blue RE, Harris SE, Guzman BB, Gentile GM, Lee EY, Tsai YH, Parker J, Dominguez D, Giudice J. Alternative splicing regulation of membrane trafficking genes during myogenesis. RNA (NEW YORK, N.Y.) 2022; 28:523-540. [PMID: 35082143 PMCID: PMC8925968 DOI: 10.1261/rna.078993.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Alternative splicing transitions occur during organ development, and, in numerous diseases, splicing programs revert to fetal isoform expression. We previously found that extensive splicing changes occur during postnatal mouse heart development in genes encoding proteins involved in vesicle-mediated trafficking. However, the regulatory mechanisms of this splicing-trafficking network are unknown. Here, we found that membrane trafficking genes are alternatively spliced in a tissue-specific manner, with striated muscles exhibiting the highest levels of alternative exon inclusion. Treatment of differentiated muscle cells with chromatin-modifying drugs altered exon inclusion in muscle cells. Examination of several RNA-binding proteins revealed that the poly-pyrimidine tract binding protein 1 (PTBP1) and quaking regulate splicing of trafficking genes during myogenesis, and that removal of PTBP1 motifs prevented PTBP1 from binding its RNA target. These findings enhance our understanding of developmental splicing regulation of membrane trafficking proteins which might have implications for muscle disease pathogenesis.
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Affiliation(s)
- Emma R Hinkle
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Hannah J Wiedner
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eduardo V Torres
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Micaela Jackson
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Adam J Black
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - R Eric Blue
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Sarah E Harris
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Bryan B Guzman
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Gabrielle M Gentile
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eunice Y Lee
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Yi-Hsuan Tsai
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Joel Parker
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Daniel Dominguez
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Jimena Giudice
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Curriculum in Genetics and Molecular Biology (GMB), The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- McAllister Heart Institute, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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23
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Overby SJ, Cerro-Herreros E, González-Martínez I, Varela MA, Seoane-Miraz D, Jad Y, Raz R, Møller T, Pérez-Alonso M, Wood MJ, Llamusí B, Artero R. Proof of concept of peptide-linked blockmiR-induced MBNL functional rescue in myotonic dystrophy type 1 mouse model. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:1146-1155. [PMID: 35282418 PMCID: PMC8888893 DOI: 10.1016/j.omtn.2022.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/06/2022] [Indexed: 01/25/2023]
Abstract
Myotonic dystrophy type 1 is a debilitating neuromuscular disease causing muscle weakness, myotonia, and cardiac dysfunction. The phenotypes are caused by muscleblind-like (MBNL) protein sequestration by toxic RNA in the DM1 protein kinase (DMPK) gene. DM1 patients exhibit a pathogenic number of repetitions in DMPK, which leads to downstream symptoms. Another disease characteristic is altered microRNA (miRNA) expression. It was previously shown that miR-23b regulates the translation of MBNL1 into protein. Antisense oligonucleotide (AON) treatment targeting this miRNA can improve disease symptoms. Here, we present a refinement of this strategy targeting a miR-23b binding site on the MBNL1 3' UTR in DM1 model cells and mice by using AONs called blockmiRs. BlockmiRs linked to novel cell-penetrating peptide chemistry showed an increase in MBNL1 protein in DM1 model cells and HSALR mice. They also showed an increase in muscle strength and significant rescue of downstream splicing and histological phenotypes in mice without disturbing the endogenous levels of other miR-23b target transcripts.
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Affiliation(s)
- Sarah J Overby
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
| | - Estefanía Cerro-Herreros
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
| | - Irene González-Martínez
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
| | - Miguel A Varela
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK.,MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
| | - David Seoane-Miraz
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK.,MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
| | - Yahya Jad
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK.,MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
| | - Richard Raz
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK.,MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
| | | | - Manuel Pérez-Alonso
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
| | - Matthew J Wood
- Department of Paediatrics, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK.,MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
| | - Beatriz Llamusí
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
| | - Rubén Artero
- University Institute of Biotechnology and Biomedicine (BIOTECMED), Universidad de Valencia, 46100 Burjassot, Spain.,Translational Genomics Group, Incliva Biomedical Research Institute, 46010 Valencia, Spain
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24
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The Splicing of the Mitochondrial Calcium Uniporter Genuine Activator MICU1 Is Driven by RBFOX2 Splicing Factor during Myogenic Differentiation. Int J Mol Sci 2022; 23:ijms23052517. [PMID: 35269658 PMCID: PMC8909990 DOI: 10.3390/ijms23052517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023] Open
Abstract
Alternative splicing, the process by which exons within a pre-mRNA transcript are differentially joined or skipped, is crucial in skeletal muscle since it is required both during myogenesis and in post-natal life to reprogram the transcripts of contractile proteins, metabolic enzymes, and transcription factors in functionally distinct muscle fiber types. The importance of such events is underlined by the numerosity of pathological conditions caused by alternative splicing aberrations. Importantly, many skeletal muscle Ca2+ homeostasis genes are also regulated by alternative splicing mechanisms, among which is the Mitochondrial Ca2+ Uniporter (MCU) genuine activator MICU1 which regulates MCU opening upon cell stimulation. We have previously shown that murine skeletal muscle MICU1 is subjected to alternative splicing, thereby generating a splice variant-which was named MICU1.1-that confers unique properties to the mitochondrial Ca2+ uptake and ensuring sufficient ATP production for muscle contraction. Here we extended the analysis of MICU1 alternative splicing to human tissues, finding two additional splicing variants that were characterized by their ability to regulate mitochondrial Ca2+ uptake. Furthermore, we found that MICU1 alternative splicing is induced during myogenesis by the splicing factor RBFOX2. These results highlight the complexity of the alternative splicing mechanisms in skeletal muscle and the regulation of mitochondrial Ca2+ among tissues.
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25
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Cellular Senescence and Aging in Myotonic Dystrophy. Int J Mol Sci 2022; 23:ijms23042339. [PMID: 35216455 PMCID: PMC8877951 DOI: 10.3390/ijms23042339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/06/2022] [Accepted: 02/12/2022] [Indexed: 01/10/2023] Open
Abstract
Myotonic dystrophy (DM) is a dominantly inherited multisystemic disorder affecting various organs, such as skeletal muscle, heart, the nervous system, and the eye. Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are caused by expanded CTG and CCTG repeats, respectively. In both forms, the mutant transcripts containing expanded repeats aggregate as nuclear foci and sequester several RNA-binding proteins, resulting in alternative splicing dysregulation. Although certain alternative splicing events are linked to the clinical DM phenotypes, the molecular mechanisms underlying multiple DM symptoms remain unclear. Interestingly, multi-systemic DM manifestations, including muscle weakness, cognitive impairment, cataract, and frontal baldness, resemble premature aging. Furthermore, cellular senescence, a critical contributor to aging, is suggested to play a key role in DM cellular pathophysiology. In particular, several senescence inducers including telomere shortening, mitochondrial dysfunction, and oxidative stress and senescence biomarkers such as cell cycle inhibitors, senescence-associated secretory phenotype, chromatin reorganization, and microRNA have been implicated in DM pathogenesis. In this review, we focus on the clinical similarities between DM and aging, and summarize the involvement of cellular senescence in DM and the potential application of anti-aging DM therapies.
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26
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Verdile V, Guizzo G, Ferrante G, Paronetto MP. RNA Targeting in Inherited Neuromuscular Disorders: Novel Therapeutic Strategies to Counteract Mis-Splicing. Cells 2021; 10:cells10112850. [PMID: 34831073 PMCID: PMC8616048 DOI: 10.3390/cells10112850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 01/14/2023] Open
Abstract
Neuromuscular disorders represent multifaceted abnormal conditions, with little or no cure, leading to patient deaths from complete muscle wasting and atrophy. Despite strong efforts in the past decades, development of effective treatments is still urgently needed. Advent of next-generation sequencing technologies has allowed identification of novel genes and mutations associated with neuromuscular pathologies, highlighting splicing defects as essential players. Deciphering the significance and relative contributions of defective RNA metabolism will be instrumental to address and counteract these malignancies. We review here recent progress on the role played by alternative splicing in ensuring functional neuromuscular junctions (NMJs), and its involvement in the pathogenesis of NMJ-related neuromuscular disorders, with particular emphasis on congenital myasthenic syndromes and muscular dystrophies. We will also discuss novel strategies based on oligonucleotides designed to bind their cognate sequences in the RNA or targeting intermediary of mRNA metabolism. These efforts resulted in several chemical classes of RNA molecules that have recently proven to be clinically effective, more potent and better tolerated than previous strategies.
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Affiliation(s)
- Veronica Verdile
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Piazza Lauro de Bosis 6, 00135 Rome, Italy
| | - Gloria Guizzo
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
| | - Gabriele Ferrante
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
| | - Maria Paola Paronetto
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Piazza Lauro de Bosis 6, 00135 Rome, Italy
- Correspondence:
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27
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Analysis of Molecular Mechanism of Erxian Decoction in Treating Osteoporosis Based on Formula Optimization Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6641838. [PMID: 34239693 PMCID: PMC8238601 DOI: 10.1155/2021/6641838] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 03/05/2021] [Accepted: 04/07/2021] [Indexed: 12/21/2022]
Abstract
Osteoporosis (OP) is a highly prevalent orthopedic condition in postmenopausal women and the elderly. Currently, OP treatments mainly include bisphosphonates, receptor activator of nuclear factor kappa-B ligand (RANKL) antibody therapy, selective estrogen receptor modulators, teriparatide (PTH1-34), and menopausal hormone therapy. However, increasing evidence has indicated these treatments may exert serious side effects. In recent years, Traditional Chinese Medicine (TCM) has become popular for treating orthopedic disorders. Erxian Decoction (EXD) is widely used for the clinical treatment of OP, but its underlying molecular mechanisms are unclear thanks to its multiple components and multiple target features. In this research, we designed a network pharmacology method, which used a novel node importance calculation model to identify critical response networks (CRNs) and effective proteins. Based on these proteins, a target coverage contribution (TCC) model was designed to infer a core active component group (CACG). This approach decoded the mechanisms underpinning EXD's role in OP therapy. Our data indicated that the drug response network mediated by the CACG effectively retained information of the component-target (C-T) network of pathogenic genes. Functional pathway enrichment analysis showed that EXD exerted therapeutic effects toward OP by targeting PI3K-Akt signaling (hsa04151), calcium signaling (hsa04020), apoptosis (hsa04210), estrogen signaling (hsa04915), and osteoclast differentiation (hsa04380) via JNK, AKT, and ERK. Our method furnishes a feasible methodological strategy for formula optimization and mechanism analysis and also supplies a reference scheme for the secondary development of the TCM formula.
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28
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Solovyeva EM, Ibebunjo C, Utzinger S, Eash JK, Dunbar A, Naumann U, Zhang Y, Serluca FC, Demirci S, Oberhauser B, Black F, Rausch M, Hoersch S, Meyer AS. New insights into molecular changes in skeletal muscle aging and disease: Differential alternative splicing and senescence. Mech Ageing Dev 2021; 197:111510. [PMID: 34019916 DOI: 10.1016/j.mad.2021.111510] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/09/2021] [Accepted: 05/17/2021] [Indexed: 02/08/2023]
Abstract
Progressive loss of muscle mass and function due to muscle fiber atrophy and loss in the elderly and chronically ill is now defined as sarcopenia. It is a major contributor to loss of independence, disability, need of long-term care as well as overall mortality. Sarcopenia is a heterogenous disease and underlying mechanisms are not completely understood. Here, we newly identified and used Tmem158, alongside Cdkn1a, as relevant senescence and denervation markers (SDMs), associated with muscle fiber atrophy. Subsequent application of laser capture microdissection (LCM) and RNA analyses revealed age- and disease-associated differences in gene expression and alternative splicing patterns in a rodent sarcopenia model. Of note, genes exhibiting such differential alternative splicing (DAS) are mainly involved in the contractile function of the muscle. Many of these splicing events are also found in a mouse model for myotonic dystrophy type 1 (DM1), underscoring the premature aging phenotype of this disease. We propose to add differential alternative splicing to the hallmarks of aging.
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Affiliation(s)
- Elizaveta M Solovyeva
- NIBR Informatics, 4056, Basel, Switzerland; V.L. Talrose Institute for Energy Problems of Chemical Physics, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia; Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region, 141701, Russia
| | | | - Stephan Utzinger
- Novartis Institute for Biomedical Research (NIBR), Musculoskeletal Diseases, 4056, Basel, Switzerland
| | - John K Eash
- NIBR, Musculoskeletal Diseases, Cambridge, MA, 02139, USA
| | - Andrew Dunbar
- NIBR, Analytical Sciences and Imaging, 4056, Basel, Switzerland
| | - Ulrike Naumann
- NIBR, Chemical Biology & Therapeutics, 4056, Basel, Switzerland
| | - Yunyu Zhang
- NIBR, Musculoskeletal Diseases, Cambridge, MA, 02139, USA
| | | | - Sabrina Demirci
- Novartis Institute for Biomedical Research (NIBR), Musculoskeletal Diseases, 4056, Basel, Switzerland
| | | | - Frederique Black
- NIBR, Cardiovascular & Metabolic Diseases, Cambridge, MA02139, USA
| | - Martin Rausch
- NIBR, Analytical Sciences and Imaging, 4056, Basel, Switzerland
| | | | - Angelika S Meyer
- Novartis Institute for Biomedical Research (NIBR), Musculoskeletal Diseases, 4056, Basel, Switzerland.
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29
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iPSC-derived cardiomyocytes from patients with myotonic dystrophy type 1 have abnormal ion channel functions and slower conduction velocities. Sci Rep 2021; 11:2500. [PMID: 33510259 PMCID: PMC7844414 DOI: 10.1038/s41598-021-82007-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023] Open
Abstract
Cardiac complications such as electrical abnormalities including conduction delays and arrhythmias are the main cause of death in individuals with Myotonic Dystrophy type 1 (DM1). We developed a disease model using iPSC-derived cardiomyocytes (iPSC-CMs) from a healthy individual and two DM1 patients with different CTG repeats lengths and clinical history (DM1-1300 and DM1-300). We confirmed the presence of toxic RNA foci and mis-spliced MBNL1/2 transcripts in DM1 iPSC-CMs. In DM1-1300, we identified a switch in the cardiac sodium channel SCN5A from the adult to the neonatal isoform. The down-regulation of adult SCN5A isoforms is consistent with a shift in the sodium current activation to depolarized potentials observed in DM1-1300. L-type calcium current density was higher in iPSC-CMs from DM1-1300, which is correlated with the overexpression of the CaV1.2 transcript and proteins. Importantly, INa and ICaL dysfunctions resulted in prolonged action potentials duration, slower velocities, and decreased overshoots. Optical mapping analysis revealed a slower conduction velocity in DM1-1300 iPSC-CM monolayers. In conclusion, our data revealed two distinct ions channels perturbations in DM1 iPSC-CM from the patient with cardiac dysfunction, one affecting Na+ channels and one affecting Ca2+ channels. Both have an impact on cardiac APs and ultimately on heart conduction.
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An Overview of Alternative Splicing Defects Implicated in Myotonic Dystrophy Type I. Genes (Basel) 2020; 11:genes11091109. [PMID: 32971903 PMCID: PMC7564762 DOI: 10.3390/genes11091109] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 01/02/2023] Open
Abstract
Myotonic dystrophy type I (DM1) is the most common form of adult muscular dystrophy, caused by expansion of a CTG triplet repeat in the 3′ untranslated region (3′UTR) of the myotonic dystrophy protein kinase (DMPK) gene. The pathological CTG repeats result in protein trapping by expanded transcripts, a decreased DMPK translation and the disruption of the chromatin structure, affecting neighboring genes expression. The muscleblind-like (MBNL) and CUG-BP and ETR-3-like factors (CELF) are two families of tissue-specific regulators of developmentally programmed alternative splicing that act as antagonist regulators of several pre-mRNA targets, including troponin 2 (TNNT2), insulin receptor (INSR), chloride channel 1 (CLCN1) and MBNL2. Sequestration of MBNL proteins and up-regulation of CELF1 are key to DM1 pathology, inducing a spliceopathy that leads to a developmental remodelling of the transcriptome due to an adult-to-foetal splicing switch, which results in the loss of cell function and viability. Moreover, recent studies indicate that additional pathogenic mechanisms may also contribute to disease pathology, including a misregulation of cellular mRNA translation, localization and stability. This review focuses on the cause and effects of MBNL and CELF1 deregulation in DM1, describing the molecular mechanisms underlying alternative splicing misregulation for a deeper understanding of DM1 complexity. To contribute to this analysis, we have prepared a comprehensive list of transcript alterations involved in DM1 pathogenesis, as well as other deregulated mRNA processing pathways implications.
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CACNA1S haploinsufficiency confers resistance to New World arenavirus infection. Proc Natl Acad Sci U S A 2020; 117:19497-19506. [PMID: 32719120 DOI: 10.1073/pnas.1920551117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the genetics of susceptibility to infectious agents is of great importance to our ability to combat disease. Here, we show that voltage-gated calcium channels (VGCCs) are critical for cellular binding and entry of the New World arenaviruses Junín and Tacaribe virus, suggesting that zoonosis via these receptors could occur. Moreover, we demonstrate that α1s haploinsufficiency renders cells and mice more resistant to infection by these viruses. In addition to being more resistant to infection, haploinsufficient cells and mice required a lower dosage of VGCC antagonists to block infection. These studies underscore the importance of genetic variation in susceptibility to both viruses and pharmaceutics.
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Gao C, Wang Y. mRNA Metabolism in Cardiac Development and Disease: Life After Transcription. Physiol Rev 2020; 100:673-694. [PMID: 31751167 PMCID: PMC7327233 DOI: 10.1152/physrev.00007.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 09/06/2019] [Accepted: 10/30/2019] [Indexed: 02/06/2023] Open
Abstract
The central dogma of molecular biology illustrates the importance of mRNAs as critical mediators between genetic information encoded at the DNA level and proteomes/metabolomes that determine the diverse functional outcome at the cellular and organ levels. Although the total number of protein-producing (coding) genes in the mammalian genome is ~20,000, it is evident that the intricate processes of cardiac development and the highly regulated physiological regulation in the normal heart, as well as the complex manifestation of pathological remodeling in a diseased heart, would require a much higher degree of complexity at the transcriptome level and beyond. Indeed, in addition to an extensive regulatory scheme implemented at the level of transcription, the complexity of transcript processing following transcription is dramatically increased. RNA processing includes post-transcriptional modification, alternative splicing, editing and transportation, ribosomal loading, and degradation. While transcriptional control of cardiac genes has been a major focus of investigation in recent decades, a great deal of progress has recently been made in our understanding of how post-transcriptional regulation of mRNA contributes to transcriptome complexity. In this review, we highlight some of the key molecular processes and major players in RNA maturation and post-transcriptional regulation. In addition, we provide an update to the recent progress made in the discovery of RNA processing regulators implicated in cardiac development and disease. While post-transcriptional modulation is a complex and challenging problem to study, recent technological advancements are paving the way for a new era of exciting discoveries and potential clinical translation in the context of cardiac biology and heart disease.
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Affiliation(s)
- Chen Gao
- Departments of Anesthesiology, Medicine, and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Yibin Wang
- Departments of Anesthesiology, Medicine, and Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
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Flucher BE. Skeletal muscle Ca V1.1 channelopathies. Pflugers Arch 2020; 472:739-754. [PMID: 32222817 PMCID: PMC7351834 DOI: 10.1007/s00424-020-02368-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/06/2020] [Accepted: 03/17/2020] [Indexed: 12/15/2022]
Abstract
CaV1.1 is specifically expressed in skeletal muscle where it functions as voltage sensor of skeletal muscle excitation-contraction (EC) coupling independently of its functions as L-type calcium channel. Consequently, all known CaV1.1-related diseases are muscle diseases and the molecular and cellular disease mechanisms relate to the dual functions of CaV1.1 in this tissue. To date, four types of muscle diseases are known that can be linked to mutations in the CACNA1S gene or to splicing defects. These are hypo- and normokalemic periodic paralysis, malignant hyperthermia susceptibility, CaV1.1-related myopathies, and myotonic dystrophy type 1. In addition, the CaV1.1 function in EC coupling is perturbed in Native American myopathy, arising from mutations in the CaV1.1-associated protein STAC3. Here, we first address general considerations concerning the possible roles of CaV1.1 in disease and then discuss the state of the art regarding the pathophysiology of the CaV1.1-related skeletal muscle diseases with an emphasis on molecular disease mechanisms.
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Affiliation(s)
- Bernhard E Flucher
- Department of Physiology and Medical Biophysics, Medical University Innsbruck, Schöpfstraße 41, A6020, Innsbruck, Austria.
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Santoro M, Piacentini R, Perna A, Pisano E, Severino A, Modoni A, Grassi C, Silvestri G. Resveratrol corrects aberrant splicing of RYR1 pre-mRNA and Ca 2+ signal in myotonic dystrophy type 1 myotubes. Neural Regen Res 2020; 15:1757-1766. [PMID: 32209783 PMCID: PMC7437583 DOI: 10.4103/1673-5374.276336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a spliceopathy related to the mis-splicing of several genes caused by sequestration of nuclear transcriptional RNA-binding factors from non-coding CUG repeats of DMPK pre-mRNAs. Dysregulation of ryanodine receptor 1 (RYR1), sarcoplasmatic/endoplasmatic Ca2+-ATPase (SERCA) and α1S subunit of voltage-gated Ca2+ channels (Cav1.1) is related to Ca2+ homeostasis and excitation-contraction coupling impairment. Though no pharmacological treatment for DM1 exists, aberrant splicing correction represents one major therapeutic target for this disease. Resveratrol (RES, 3,5,4′-trihydroxy-trans-stilbene) is a promising pharmacological tools for DM1 treatment for its ability to directly bind the DNA and RNA influencing gene expression and alternative splicing. Herein, we analyzed the therapeutic effects of RES in DM1 myotubes in a pilot study including cultured myotubes from two DM1 patients and two healthy controls. Our results indicated that RES treatment corrected the aberrant splicing of RYR1, and this event appeared associated with restoring of depolarization-induced Ca2+ release from RYR1 dependent on the electro-mechanical coupling between RYR1 and Cav1.1. Interestingly, immunoblotting studies showed that RES treatment was associated with a reduction in the levels of CUGBP Elav-like family member 1, while RYR1, Cav1.1 and SERCA1 protein levels were unchanged. Finally, RES treatment did not induce any major changes either in the amount of ribonuclear foci or sequestration of muscleblind-like splicing regulator 1. Overall, the results of this pilot study would support RES as an attractive compound for future clinical trials in DM1. Ethical approval was obtained from the Ethical Committee of IRCCS Fondazione Policlinico Universitario A. Gemelli, Rome, Italy (rs9879/14) on May 20, 2014.
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Affiliation(s)
| | - Roberto Piacentini
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Alessia Perna
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Eugenia Pisano
- Department of Cardiovascular and Thoracic Sciences, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Anna Severino
- Department of Cardiovascular and Thoracic Sciences, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Anna Modoni
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Gabriella Silvestri
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
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Shields RK, Lee J, Buelow A, Petrie M, Dudley-Javoroski S, Cross S, Gutmann L, Nopoulos PC. Myotonic dystrophy type 1 alters muscle twitch properties, spinal reflexes, and perturbation-induced trans-cortical reflexes. Muscle Nerve 2019; 61:205-212. [PMID: 31773755 DOI: 10.1002/mus.26767] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/20/2019] [Accepted: 11/23/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Neurophysiologic biomarkers are needed for clinical trials of therapies for myotonic dystrophy (DM1). We characterized muscle properties, spinal reflexes (H-reflexes), and trans-cortical long-latency reflexes (LLRs) in a cohort with mild/moderate DM1. METHODS Twenty-four people with DM1 and 25 matched controls underwent assessment of tibial nerve H-reflexes and soleus muscle twitch properties. Quadriceps LLRs were elicited by delivering an unexpected perturbation during a single-limb squat (SLS) visuomotor tracking task. RESULTS DM1 was associated with decreased H-reflex depression. The efficacy of doublet stimulation was enhanced, yielding an elevated double-single twitch ratio. DM1 participants demonstrated greater error during the SLS task. DM1 individuals with the least-robust LLR responses showed the greatest loss of spinal H-reflex depression. CONCLUSIONS DM1 is associated with abnormalities of muscle twitch properties. Co-occurring alterations of spinal and trans-cortical reflex properties underscore the central nervous system manifestations of this disorder and may assist in gauging efficacy during clinical trials.
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Affiliation(s)
- Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Jinhyun Lee
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Aaron Buelow
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Michael Petrie
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Shauna Dudley-Javoroski
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Stephen Cross
- Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Laurie Gutmann
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Peggy C Nopoulos
- Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
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López Castel A, Overby SJ, Artero R. MicroRNA-Based Therapeutic Perspectives in Myotonic Dystrophy. Int J Mol Sci 2019; 20:ijms20225600. [PMID: 31717488 PMCID: PMC6888406 DOI: 10.3390/ijms20225600] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 12/20/2022] Open
Abstract
Myotonic dystrophy involves two types of chronically debilitating rare neuromuscular diseases: type 1 (DM1) and type 2 (DM2). Both share similarities in molecular cause, clinical signs, and symptoms with DM2 patients usually displaying milder phenotypes. It is well documented that key clinical symptoms in DM are associated with a strong mis-regulation of RNA metabolism observed in patient’s cells. This mis-regulation is triggered by two leading DM-linked events: the sequestration of Muscleblind-like proteins (MBNL) and the mis-regulation of the CUGBP RNA-Binding Protein Elav-Like Family Member 1 (CELF1) that cause significant alterations to their important functions in RNA processing. It has been suggested that DM1 may be treatable through endogenous modulation of the expression of MBNL and CELF1 proteins. In this study, we analyzed the recent identification of the involvement of microRNA (miRNA) molecules in DM and focus on the modulation of these miRNAs to therapeutically restore normal MBNL or CELF1 function. We also discuss additional prospective miRNA targets, the use of miRNAs as disease biomarkers, and additional promising miRNA-based and miRNA-targeting drug development strategies. This review provides a unifying overview of the dispersed data on miRNA available in the context of DM.
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Affiliation(s)
- Arturo López Castel
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
- Correspondence: (A.L.C.); (R.A.)
| | - Sarah Joann Overby
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
| | - Rubén Artero
- Translational Genomics Group, Incliva Health Research Institute, Burjassot, 46100 Valencia, Spain
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (Eri Biotecmed), University of Valencia, Burjassot, 46100 Valencia, Spain
- Correspondence: (A.L.C.); (R.A.)
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Nutter CA, Bubenik JL, Oliveira R, Ivankovic F, Sznajder ŁJ, Kidd BM, Pinto BS, Otero BA, Carter HA, Vitriol EA, Wang ET, Swanson MS. Cell-type-specific dysregulation of RNA alternative splicing in short tandem repeat mouse knockin models of myotonic dystrophy. Genes Dev 2019; 33:1635-1640. [PMID: 31624084 PMCID: PMC6942047 DOI: 10.1101/gad.328963.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/24/2019] [Indexed: 11/25/2022]
Abstract
Short tandem repeats (STRs) are prone to expansion mutations that cause multiple hereditary neurological and neuromuscular diseases. To study pathomechanisms using mouse models that recapitulate the tissue specificity and developmental timing of an STR expansion gene, we used rolling circle amplification and CRISPR/Cas9-mediated genome editing to generate Dmpk CTG expansion (CTGexp) knockin models of myotonic dystrophy type 1 (DM1). We demonstrate that skeletal muscle myoblasts and brain choroid plexus epithelial cells are particularly susceptible to Dmpk CTGexp mutations and RNA missplicing. Our results implicate dysregulation of muscle regeneration and cerebrospinal fluid homeostasis as early pathogenic events in DM1.
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Affiliation(s)
- Curtis A Nutter
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Jodi L Bubenik
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Ruan Oliveira
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Franjo Ivankovic
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Benjamin M Kidd
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Belinda S Pinto
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Brittney A Otero
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Helmut A Carter
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Eric A Vitriol
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, Florida 32610, USA
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, Gainesville, Florida 32610, USA
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Bosè F, Renna LV, Fossati B, Arpa G, Labate V, Milani V, Botta A, Micaglio E, Meola G, Cardani R. TNNT2 Missplicing in Skeletal Muscle as a Cardiac Biomarker in Myotonic Dystrophy Type 1 but Not in Myotonic Dystrophy Type 2. Front Neurol 2019; 10:992. [PMID: 31611837 PMCID: PMC6776629 DOI: 10.3389/fneur.2019.00992] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/02/2019] [Indexed: 12/31/2022] Open
Abstract
Cardiac involvement is one of the most important manifestations of the multisystemic phenotype of patients affected by myotonic dystrophy (DM) and represents the second cause of premature death. Molecular mechanisms responsible for DM cardiac defects are still unclear; however, missplicing of the cardiac isoform of troponin T (TNNT2) and of the cardiac sodium channel (SCN5A) genes might contribute to the reduced myocardial function and conduction abnormalities seen in DM patients. Since, in DM skeletal muscle, the TNNT2 gene shows the same aberrant splicing pattern observed in cardiac muscle, the principal aim of this work was to verify if the TNNT2 aberrant fetal isoform expression could be secondary to myopathic changes or could reflect the DM cardiac phenotype. Analysis of alternative splicing of TNNT2 and of several genes involved in DM pathology has been performed on muscle biopsies from patients affected by DM type 1 (DM1) or type 2 (DM2) with or without cardiac involvement. Our analysis shows that missplicing of muscle-specific genes is higher in DM1 and DM2 than in regenerating control muscles, indicating that these missplicing could be effectively important in DM skeletal muscle pathology. When considering the TNNT2 gene, missplicing appears to be more evident in DM1 than in DM2 muscles since, in DM2, the TNNT2 fetal isoform appears to be less expressed than the adult isoform. This evidence does not seem to be related to less severe muscle histopathological alterations that appear to be similar in DM1 and DM2 muscles. These results seem to indicate that the more severe TNNT2 missplicing observed in DM1 could not be related only to myopathic changes but could reflect the more severe general phenotype compared to DM2, including cardiac problems that appear to be more severe and frequent in DM1 than in DM2 patients. Moreover, TNNT2 missplicing significantly correlates with the QRS cardiac parameter in DM1 but not in DM2 patients, indicating that this splicing event has good potential to function as a biomarker of DM1 severity and it should be considered in pharmacological clinical trials to monitor the possible effects of different therapeutic approaches on skeletal muscle tissues.
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Affiliation(s)
- Francesca Bosè
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
| | - Laura Valentina Renna
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
| | - Barbara Fossati
- Department of Neurology, IRCCS-Policlinico San Donato, Milan, Italy.,Department of Neurorehabilitation Sciences, Casa Cura Policlinico (CCP), Milan, Italy
| | - Giovanni Arpa
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Valentina Labate
- University Cardiology Unit, IRCCS-Policlinico San Donato, Milan, Italy
| | - Valentina Milani
- Scientific Directorate, IRCCS Policlinico San Donato, Milan, Italy
| | - Annalisa Botta
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Emanuele Micaglio
- Department of Arrhythmology, IRCCS Policlinico San Donato, Milan, Italy
| | - Giovanni Meola
- Department of Neurology, IRCCS-Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
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Mondragon-Gonzalez R, Azzag K, Selvaraj S, Yamamoto A, Perlingeiro RCR. Transplantation studies reveal internuclear transfer of toxic RNA in engrafted muscles of myotonic dystrophy 1 mice. EBioMedicine 2019; 47:553-562. [PMID: 31446083 PMCID: PMC6796515 DOI: 10.1016/j.ebiom.2019.08.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 08/05/2019] [Accepted: 08/14/2019] [Indexed: 12/11/2022] Open
Abstract
Background Stem cell transplantation represents a potential therapeutic option for muscular dystrophies (MD). However, to date, most reports have utilized mouse models for recessive types of MD. Here we performed studies to determine whether myotonic dystrophy 1 (DM1), an autosomal dominant type of MD, could benefit from cell transplantation. Methods We injected human pluripotent stem (PS) cell-derived myogenic progenitors into the muscles of a novel mouse model combining immunodeficiency and skeletal muscle pathology of DM1 and investigated transplanted mice for engraftment as well as for the presence of RNA foci and alternative splicing pattern. Findings Engraftment was clearly observed in recipient mice, but unexpectedly, we detected RNA foci in donor-derived engrafted myonuclei. These foci proved to be pathogenic as we observed MBNL1 sequestration and abnormal alternative splicing in donor-derived transcripts. Interpretation It has been assumed that toxic CUG repeat-containing RNA forms foci in situ in the nucleus in which it is expressed, but these data suggest that CUG repeat-containing RNA may also exit the nucleus and traffic to other nuclei in the syncytial myofiber, where it can exert pathological effects. Fund This project was supported by funds from the LaBonte/Shawn family and NIH grants R01 AR055299 and AR071439 (R.C.R.P.). R.M-G. was funded by CONACyT-Mexico (#394378).
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Affiliation(s)
- Ricardo Mondragon-Gonzalez
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Mexico City, Mexico
| | - Karim Azzag
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Sridhar Selvaraj
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Ami Yamamoto
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Stem Cell Institute, University of Minnesota, Minneapolis, MN, USA.
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Jenquin JR, Yang H, Huigens RW, Nakamori M, Berglund JA. Combination Treatment of Erythromycin and Furamidine Provides Additive and Synergistic Rescue of Mis-Splicing in Myotonic Dystrophy Type 1 Models. ACS Pharmacol Transl Sci 2019; 2:247-263. [PMID: 31485578 DOI: 10.1021/acsptsci.9b00020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is a multi-systemic disease that presents with clinical symptoms including myotonia, cardiac dysfunction and cognitive impairment. DM1 is caused by a CTG expansion in the 3' UTR of the DMPK gene. The transcribed expanded CUG repeat RNA sequester the muscleblind-like (MBNL) and up-regulate the CUG-BP Elav-like (CELF) families of RNA-binding proteins leading to global mis-regulation of RNA processing and altered gene expression. Currently, there are no disease-targeting treatments for DM1. Given the multi-step pathogenic mechanism, combination therapies targeting different aspects of the disease mechanism may be a viable therapeutic approach. Here, as proof-of-concept, we studied a combination of two previously characterized small molecules, erythromycin and furamidine, in two DM1 models. In DM1 patient-derived myotubes, rescue of mis-splicing was observed with little to no cell toxicity. In a DM1 mouse model, a combination of erythromycin and the prodrug of furamidine (pafuramidine), administered orally, displayed both additive and synergistic mis-splicing rescue. Gene expression was only modestly affected and over 40 % of the genes showing significant expression changes were rescued back toward WT expression levels. Further, the combination treatment partially rescued the myotonia phenotype in the DM1 mouse. This combination treatment showed a high degree of mis-splicing rescue coupled with low off-target gene expression changes. These results indicate that combination therapies are a promising therapeutic approach for DM1.
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Affiliation(s)
- Jana R Jenquin
- Department of Biochemistry & Molecular Biology, Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA
| | - Hongfen Yang
- Department of Medicinal Chemistry, Center for Natural Products Drug Discovery and Development, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Robert W Huigens
- Department of Medicinal Chemistry, Center for Natural Products Drug Discovery and Development, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA
| | - Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - J Andrew Berglund
- Department of Biochemistry & Molecular Biology, Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.,Department of Biological Sciences, RNA Institute, College of Arts and Sciences, University at Albany-SUNY, Albany, New York, 12222, USA
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41
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Sznajder ŁJ, Swanson MS. Short Tandem Repeat Expansions and RNA-Mediated Pathogenesis in Myotonic Dystrophy. Int J Mol Sci 2019; 20:ijms20133365. [PMID: 31323950 PMCID: PMC6651174 DOI: 10.3390/ijms20133365] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/27/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022] Open
Abstract
Short tandem repeat (STR) or microsatellite, expansions underlie more than 50 hereditary neurological, neuromuscular and other diseases, including myotonic dystrophy types 1 (DM1) and 2 (DM2). Current disease models for DM1 and DM2 propose a common pathomechanism, whereby the transcription of mutant DMPK (DM1) and CNBP (DM2) genes results in the synthesis of CUG and CCUG repeat expansion (CUGexp, CCUGexp) RNAs, respectively. These CUGexp and CCUGexp RNAs are toxic since they promote the assembly of ribonucleoprotein (RNP) complexes or RNA foci, leading to sequestration of Muscleblind-like (MBNL) proteins in the nucleus and global dysregulation of the processing, localization and stability of MBNL target RNAs. STR expansion RNAs also form phase-separated gel-like droplets both in vitro and in transiently transfected cells, implicating RNA-RNA multivalent interactions as drivers of RNA foci formation. Importantly, the nucleation and growth of these nuclear foci and transcript misprocessing are reversible processes and thus amenable to therapeutic intervention. In this review, we provide an overview of potential DM1 and DM2 pathomechanisms, followed by a discussion of MBNL functions in RNA processing and how multivalent interactions between expanded STR RNAs and RNA-binding proteins (RBPs) promote RNA foci assembly.
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Affiliation(s)
- Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA.
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
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42
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Wang ET, Treacy D, Eichinger K, Struck A, Estabrook J, Olafson H, Wang TT, Bhatt K, Westbrook T, Sedehizadeh S, Ward A, Day J, Brook D, Berglund JA, Cooper T, Housman D, Thornton C, Burge C. Transcriptome alterations in myotonic dystrophy skeletal muscle and heart. Hum Mol Genet 2019; 28:1312-1321. [PMID: 30561649 DOI: 10.1093/hmg/ddy432] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/30/2018] [Accepted: 12/10/2018] [Indexed: 11/12/2022] Open
Abstract
Myotonic dystrophy (dystrophia myotonica, DM) is a multi-systemic disease caused by expanded CTG or CCTG microsatellite repeats. Characterized by symptoms in muscle, heart and central nervous system, among others, it is one of the most variable diseases known. A major pathogenic event in DM is the sequestration of muscleblind-like proteins by CUG or CCUG repeat-containing RNAs transcribed from expanded repeats, and differences in the extent of MBNL sequestration dependent on repeat length and expression level may account for some portion of the variability. However, many other cellular pathways are reported to be perturbed in DM, and the severity of specific disease symptoms varies among individuals. To help understand this variability and facilitate research into DM, we generated 120 RNASeq transcriptomes from skeletal and heart muscle derived from healthy and DM1 biopsies and autopsies. A limited number of DM2 and Duchenne muscular dystrophy samples were also sequenced. We analyzed splicing and gene expression, identified tissue-specific changes in RNA processing and uncovered transcriptome changes strongly correlating with muscle strength. We created a web resource at http://DMseq.org that hosts raw and processed transcriptome data and provides a lightweight, responsive interface that enables browsing of processed data across the genome.
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Affiliation(s)
- Eric T Wang
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Koch Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL, USA.,Center for NeuroGenetics, University of Florida, Gainesville, FL, USA.,University of Florida Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Daniel Treacy
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Katy Eichinger
- Department of Neurology, University of Rochester, Rochester, NY, USA
| | - Adam Struck
- Department of Biochemistry, University of Oregon, Eugene, OR, USA
| | - Joseph Estabrook
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Koch Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL, USA.,Center for NeuroGenetics, University of Florida, Gainesville, FL, USA.,University of Florida Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Hailey Olafson
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL, USA.,Center for NeuroGenetics, University of Florida, Gainesville, FL, USA.,University of Florida Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Thomas T Wang
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kirti Bhatt
- Department of Neurology, University of Rochester, Rochester, NY, USA
| | - Tony Westbrook
- School of Life Sciences, Queen's Medical Center, University of Nottingham, Nottingham, UK
| | - Sam Sedehizadeh
- School of Life Sciences, Queen's Medical Center, University of Nottingham, Nottingham, UK
| | - Amanda Ward
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - John Day
- Department of Neurology, Stanford University, Palo Alto, CA, USA
| | - David Brook
- School of Life Sciences, Queen's Medical Center, University of Nottingham, Nottingham, UK
| | - J Andrew Berglund
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL, USA.,Center for NeuroGenetics, University of Florida, Gainesville, FL, USA.,University of Florida Genetics Institute, University of Florida, Gainesville, FL, USA.,Department of Biochemistry, University of Oregon, Eugene, OR, USA
| | - Thomas Cooper
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - David Housman
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Koch Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Charles Thornton
- Department of Neurology, University of Rochester, Rochester, NY, USA
| | - Christopher Burge
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Koch Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
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43
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Ravel-Chapuis A, Al-Rewashdy A, Bélanger G, Jasmin BJ. Pharmacological and physiological activation of AMPK improves the spliceopathy in DM1 mouse muscles. Hum Mol Genet 2019; 27:3361-3376. [PMID: 29982462 DOI: 10.1093/hmg/ddy245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/28/2018] [Indexed: 12/26/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a debilitating multisystemic disorder caused by a triplet repeat expansion in the 3' untranslated region of dystrophia myotonica protein kinase mRNAs. Mutant mRNAs accumulate in the nucleus of affected cells and misregulate RNA-binding proteins, thereby promoting characteristic missplicing events. However, little is known about the signaling pathways that may be affected in DM1. Here, we investigated the status of activated protein kinase (AMPK) signaling in DM1 skeletal muscle and found that the AMPK pathway is markedly repressed in a DM1 mouse model (human skeletal actin-long repeat, HSALR) and patient-derived DM1 myoblasts. Chronic pharmacological activation of AMPK signaling in DM1 mice with 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) has multiple beneficial effects on the DM1 phenotype. Indeed, a 6-week AICAR treatment of DM1 mice promoted expression of a slower, more oxidative phenotype, improved muscle histology and corrected several events associated with RNA toxicity. Importantly, AICAR also had a dose-dependent positive effect on the spliceopathy in patient-derived DM1 myoblasts. In separate experiments, we also show that chronic treatment of DM1 mice with resveratrol as well as voluntary wheel running also rescued missplicing events in muscle. Collectively, our findings demonstrate the therapeutic potential of chronic AMPK stimulation both physiologically and pharmacologically for DM1 patients.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Ali Al-Rewashdy
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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44
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Manta A, Stouth DW, Xhuti D, Chi L, Rebalka IA, Kalmar JM, Hawke TJ, Ljubicic V. Chronic exercise mitigates disease mechanisms and improves muscle function in myotonic dystrophy type 1 mice. J Physiol 2019; 597:1361-1381. [PMID: 30628727 DOI: 10.1113/jp277123] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 01/04/2019] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Myotonic dystrophy type 1 (DM1), the second most common muscular dystrophy and most prevalent adult form of muscular dystrophy, is characterized by muscle weakness, wasting and myotonia. A microsatellite repeat expansion mutation results in RNA toxicity and dysregulation of mRNA processing, which are the primary downstream causes of the disorder. Recent studies with DM1 participants demonstrate that exercise is safe, enjoyable and elicits benefits in muscle strength and function; however, the molecular mechanisms of exercise adaptation in DM1 are undefined. Our results demonstrate that 7 weeks of volitional running wheel exercise in a pre-clinical DM1 mouse model resulted in significantly improved motor performance, muscle strength and endurance, as well as reduced myotonia. At the cellular level, chronic physical activity attenuated RNA toxicity, liberated Muscleblind-like 1 protein from myonuclear foci and improved mRNA alternative splicing. ABSTRACT Myotonic dystrophy type 1 (DM1) is a trinucleotide repeat expansion neuromuscular disorder that is most prominently characterized by skeletal muscle weakness, wasting and myotonia. Chronic physical activity is safe and satisfying, and can elicit functional benefits such as improved strength and endurance in DM1 patients, but the underlying cellular basis of exercise adaptation is undefined. Our purpose was to examine the mechanisms of exercise biology in DM1. Healthy, sedentary wild-type (SED-WT) mice, as well as sedentary human skeletal actin-long repeat animals, a murine model of DM1 myopathy (SED-DM1), and DM1 mice with volitional access to a running wheel for 7 weeks (EX-DM1), were utilized. Chronic exercise augmented strength and endurance in vivo and in situ in DM1 mice. These alterations coincided with normalized measures of myopathy, as well as increased mitochondrial content. Electromyography revealed a 70-85% decrease in the duration of myotonic discharges in muscles from EX-DM1 compared to SED-DM1 animals. The exercise-induced enhancements in muscle function corresponded at the molecular level with mitigated spliceopathy, specifically the processing of bridging integrator 1 and muscle-specific chloride channel (CLC-1) transcripts. CLC-1 protein content and sarcolemmal expression were lower in SED-DM1 versus SED-WT animals, but they were similar between SED-WT and EX-DM1 groups. Chronic exercise also attenuated RNA toxicity, as indicated by reduced (CUG)n foci-positive myonuclei and sequestered Muscleblind-like 1 (MBNL1). Our data indicate that chronic exercise-induced physiological improvements in DM1 occur in concert with mitigated primary downstream disease mechanisms, including RNA toxicity, MBNL1 loss-of-function, and alternative mRNA splicing.
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Affiliation(s)
- Alexander Manta
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Derek W Stouth
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Donald Xhuti
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Leon Chi
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Irena A Rebalka
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Jayne M Kalmar
- Department of Kinesiology & Physical Education, Wilfred Laurier University, Waterloo, ON, Canada, N2L 3C5
| | - Thomas J Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Vladimir Ljubicic
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada, L8S 4K1
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45
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Hinkle ER, Wiedner HJ, Black AJ, Giudice J. RNA processing in skeletal muscle biology and disease. Transcription 2019; 10:1-20. [PMID: 30556762 DOI: 10.1080/21541264.2018.1558677] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
RNA processing encompasses the capping, cleavage, polyadenylation and alternative splicing of pre-mRNA. Proper muscle development relies on precise RNA processing, driven by the coordination between RNA-binding proteins. Recently, skeletal muscle biology has been intensely investigated in terms of RNA processing. High throughput studies paired with deletion of RNA-binding proteins have provided a high-level understanding of the molecular mechanisms controlling the regulation of RNA-processing in skeletal muscle. Furthermore, misregulation of RNA processing is implicated in muscle diseases. In this review, we comprehensively summarize recent studies in skeletal muscle that demonstrated: (i) the importance of RNA processing, (ii) the RNA-binding proteins that are involved, and (iii) diseases associated with defects in RNA processing.
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Affiliation(s)
- Emma R Hinkle
- a Curriculum in Genetics and Molecular Biology (GMB) , University of North Carolina , Chapel Hill , USA.,b Department of Cell Biology & Physiology , University of North Carolina , Chapel Hill , USA
| | - Hannah J Wiedner
- a Curriculum in Genetics and Molecular Biology (GMB) , University of North Carolina , Chapel Hill , USA.,b Department of Cell Biology & Physiology , University of North Carolina , Chapel Hill , USA
| | - Adam J Black
- b Department of Cell Biology & Physiology , University of North Carolina , Chapel Hill , USA
| | - Jimena Giudice
- a Curriculum in Genetics and Molecular Biology (GMB) , University of North Carolina , Chapel Hill , USA.,b Department of Cell Biology & Physiology , University of North Carolina , Chapel Hill , USA.,c McAllister Heart Institute , University of North Carolina , Chapel Hill , USA
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46
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Glineburg MR, Todd PK, Charlet-Berguerand N, Sellier C. Repeat-associated non-AUG (RAN) translation and other molecular mechanisms in Fragile X Tremor Ataxia Syndrome. Brain Res 2018; 1693:43-54. [PMID: 29453961 PMCID: PMC6010627 DOI: 10.1016/j.brainres.2018.02.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 11/11/2022]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset inherited neurodegenerative disorder characterized by progressive intention tremor, gait ataxia and dementia associated with mild brain atrophy. The cause of FXTAS is a premutation expansion, of 55 to 200 CGG repeats localized within the 5'UTR of FMR1. These repeats are transcribed in the sense and antisense directions into mutants RNAs, which have increased expression in FXTAS. Furthermore, CGG sense and CCG antisense expanded repeats are translated into novel proteins despite their localization in putatively non-coding regions of the transcript. Here we focus on two proposed disease mechanisms for FXTAS: 1) RNA gain-of-function, whereby the mutant RNAs bind specific proteins and preclude their normal functions, and 2) repeat-associated non-AUG (RAN) translation, whereby translation through the CGG or CCG repeats leads to the production of toxic homopolypeptides, which in turn interfere with a variety of cellular functions. Here, we analyze the data generated to date on both of these potential molecular mechanisms and lay out a path forward for determining which factors drive FXTAS pathogenicity.
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Affiliation(s)
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Veteran's Affairs Medical Center, Ann Arbor, MI 48105, USA
| | - Nicolas Charlet-Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France.
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47
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Diastolic heart dysfunction is correlated with CTG repeat length in myotonic dystrophy type 1. Neurol Sci 2018; 39:1935-1943. [PMID: 30094526 DOI: 10.1007/s10072-018-3530-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/07/2018] [Indexed: 12/21/2022]
Abstract
The aims of this study were to investigate the correlations of tri-nucleotide (CTG) repeat length with detailed echocardiography (ECHO) parameters that represent myocardial function and to find a relationship between heart function and CTG repeat length in adult-onset myotonic dystrophy type 1 (DM1). In this study, clinical data for patients with DM1, including age, onset age, CTG repeat length, Medical Research Council sum score (MRCSS), and 6-min walking test (6MWT), were recorded. In addition, ECHO parameters and cardiac conduction abnormalities were evaluated. Among the cardiac parameters, the EA ratio and left ventricular end-diastolic dimension (LVEDD) were significantly correlated with the CTG repeat length (p < 0.05). Interventricular septal thickness at end-diastole was also significantly correlated with the 6MWT in a multivariate linear regression model (p < 0.05). In conclusion, motor function (MRCSS and 6MWT) and CTG repeat length significantly correlated with LV diastolic dysfunction in patients with DM1. More emphasis should be given to diastolic dysfunction, which is currently under-recognized, when evaluating patients with DM1 with no abnormalities in routine electrocardiography studies. Lastly, well-designed and longitudinal studies are warranted to characterize and understand the pathophysiology of diastolic dysfunction in DM1.
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48
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Mondragon-Gonzalez R, Perlingeiro RCR. Recapitulating muscle disease phenotypes with myotonic dystrophy 1 induced pluripotent stem cells: a tool for disease modeling and drug discovery. Dis Model Mech 2018; 11:dmm.034728. [PMID: 29898953 PMCID: PMC6078411 DOI: 10.1242/dmm.034728] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/07/2018] [Indexed: 12/27/2022] Open
Abstract
Myotonic dystrophy 1 (DM1) is a multisystem disorder primarily affecting the central nervous system, heart and skeletal muscle. It is caused by an expansion of the CTG trinucleotide repeats in the 3' untranslated region of the DMPK gene. Although patient myoblasts have been used for studying the disease in vitro, the invasiveness as well as the low accessibility to muscle biopsies motivate the development of alternative reliable myogenic models. Here, we established two DM1 induced pluripotent stem (iPS) cell lines from patient-derived fibroblasts and, using the PAX7 conditional expression system, differentiated these into myogenic progenitors and, subsequently, terminally differentiated myotubes. Both DM1 myogenic progenitors and myotubes were found to express the intranuclear RNA foci exhibiting sequestration of MBNL1. Moreover, we found the DM1-related mis-splicing, namely BIN1 exon 11 in DM1 myotubes. We used this model to test a specific therapy, antisense oligonucleotide treatment, and found that this efficiently abolished RNA foci and rescued BIN1 mis-splicing in DM1 iPS cell-derived myotubes. Together, our results demonstrate that myotubes derived from DM1 iPS cells recapitulate the critical molecular features of DM1 and are sensitive to antisense oligonucleotide treatment, confirming that these cells can be used for in vitro disease modeling and candidate drug testing or screening.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ricardo Mondragon-Gonzalez
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA.,Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México City 07360, Mexico
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
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49
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Chakraborty M, Llamusi B, Artero R. Modeling of Myotonic Dystrophy Cardiac Phenotypes in Drosophila. Front Neurol 2018; 9:473. [PMID: 30061855 PMCID: PMC6054993 DOI: 10.3389/fneur.2018.00473] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/31/2018] [Indexed: 01/07/2023] Open
Abstract
After respiratory distress, cardiac dysfunction is the second most common cause of fatality associated with the myotonic dystrophy (DM) disease. Despite the prevalance of heart failure in DM, physiopathological studies on heart symptoms have been relatively scarce because few murine models faithfully reproduce the cardiac disease. Consequently, only a small number of candidate compounds have been evaluated in this specific phenotype. To help cover this gap Drosophila combines the amenability of its invertebrate genetics with the possibility of quickly acquiring physiological parameters suitable for meaningful comparisons with vertebrate animal models and humans. Here we review available descriptions of cardiac disease in DM type 1 and type 2, and three recent papers reporting the cardiac toxicity of non-coding CUG (DM1) and CCUG (DM2) repeat RNA in flies. Notably, flies expressing CUG or CCUG RNA in their hearts developed strong arrhythmias and had reduced fractional shortening, which correlates with similar phenotypes in DM patients. Overexpression of Muscleblind, which is abnormally sequestered by CUG and CCUG repeat RNA, managed to strongly suppress arrhythmias and fractional shortening, thus demonstrating that Muscleblind depletion causes cardiac phenotypes in flies. Importantly, small molecules pentamidine and daunorubicin were able to rescue cardiac phenotypes by releasing Muscleblind from sequestration. Taken together, fly heart models have the potential to make important contributions to the understanding of the molecular causes of cardiac dysfunction in DM and in the quick assessment of candidate therapeutics.
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Affiliation(s)
- Mouli Chakraborty
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain.,Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain.,CIPF-INCLIVA Joint Unit, Valencia, Spain
| | - Beatriz Llamusi
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain.,Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain.,CIPF-INCLIVA Joint Unit, Valencia, Spain
| | - Ruben Artero
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain.,Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain.,CIPF-INCLIVA Joint Unit, Valencia, Spain
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50
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Braz SO, Acquaire J, Gourdon G, Gomes-Pereira M. Of Mice and Men: Advances in the Understanding of Neuromuscular Aspects of Myotonic Dystrophy. Front Neurol 2018; 9:519. [PMID: 30050493 PMCID: PMC6050950 DOI: 10.3389/fneur.2018.00519] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Intensive effort has been directed toward the modeling of myotonic dystrophy (DM) in mice, in order to reproduce human disease and to provide useful tools to investigate molecular and cellular pathogenesis and test efficient therapies. Mouse models have contributed to dissect the multifaceted impact of the DM mutation in various tissues, cell types and in a pleiotropy of pathways, through the expression of toxic RNA transcripts. Changes in alternative splicing, transcription, translation, intracellular RNA localization, polyadenylation, miRNA metabolism and phosphorylation of disease intermediates have been described in different tissues. Some of these events have been directly associated with specific disease symptoms in the skeletal muscle and heart of mice, offering the molecular explanation for individual disease phenotypes. In the central nervous system (CNS), however, the situation is more complex. We still do not know how the molecular abnormalities described translate into CNS dysfunction, nor do we know if the correction of individual molecular events will provide significant therapeutic benefits. The variability in model design and phenotypes described so far requires a thorough and critical analysis. In this review we discuss the recent contributions of mouse models to the understanding of neuromuscular aspects of disease, therapy development, and we provide a reflective assessment of our current limitations and pressing questions that remain unanswered.
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Affiliation(s)
- Sandra O Braz
- Laboratory CTGDM, INSERM UMR1163, Paris, France.,Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Julien Acquaire
- Laboratory CTGDM, INSERM UMR1163, Paris, France.,Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Geneviève Gourdon
- Laboratory CTGDM, INSERM UMR1163, Paris, France.,Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Mário Gomes-Pereira
- Laboratory CTGDM, INSERM UMR1163, Paris, France.,Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, Paris, France
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