1
|
Wahbi K, Bassez G, Duchateau J, Salort-Campana E, Vicart S, Desaphy JF, Labombarda F, Sellal JM, Deharo JC. Expert opinion on mexiletine treatment in adult patients with myotonic dystrophy. Arch Cardiovasc Dis 2024; 117:450-456. [PMID: 38677940 DOI: 10.1016/j.acvd.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 03/13/2024] [Accepted: 03/25/2024] [Indexed: 04/29/2024]
Abstract
In France, mexiletine - a class I antiarrhythmic drug - can be prescribed for the symptomatic treatment of myotonia of the skeletal muscles in adult patients with myotonic dystrophy under a compassionate use programme. Mexiletine is used according to its summary of product characteristics, which describes its use for myotonia treatment in adult patients with non-dystrophic myotonia, a different neuromuscular condition without cardiac involvement. A cardiac assessment is required prior to initiation and throughout treatment due to potential proarrhythmic effects. The presence of conduction system disease, the most common cardiac manifestation of myotonic dystrophy, mandates repeated cardiac evaluations in patients with this condition, and becomes even more important when they are given mexiletine. A group of experts, including three neurologists and five cardiologists from French neuromuscular reference centres, were involved in a task force to develop a treatment algorithm to guide mexiletine use in myotonic dystrophy. The recommendations are based on data from a literature review of the safety of mexiletine-treated patients with myotonic dystrophy, the compassionate use protocol for mexiletine and the personal clinical experience of the experts. The main conclusion of the expert group is that, although existing safety data in mexiletine-treated patients with myotonic dystrophy are reassuring, cardiac assessments should be reinforced in such patients compared with mexiletine-treated patients with non-dystrophic myotonia. This expert opinion to guide mexiletine treatment in patients with myotonic dystrophy should help to reduce the risk of severe adverse events and facilitate interactions between specialists involved in the routine care of patients with myotonic dystrophy.
Collapse
Affiliation(s)
- Karim Wahbi
- Centre de Référence des Maladies Neuromusculaires Nord/Est/Île-de-France, Cardiology Department, Cochin Hospital, AP-HP, Paris Cité University, 75014 Paris, France; Paris Cardiovascular Research Centre (PARCC), Inserm Unit 970, Georges-Pompidou European Hospital, 75015 Paris, France.
| | - Guillaume Bassez
- Constitutive Reference Centre for Neuromuscular Diseases, Neuro-Myology Department, Pitié-Salpêtrière University Hospital, AP-HP, 75013 Paris, France
| | - Josselin Duchateau
- Department of Cardiology, Electrophysiology and Cardiac Pacing, Haut l'Evêque Cardiology Hospital, CHU de Bordeaux, 33604 Pessac, France
| | - Emmanuelle Salort-Campana
- Reference Centre for Neuromuscular Diseases PACA/Réunion/Rhône Alpes, La Timone Hospital, CHU de Marseille, AP-HM, 13385 Marseille, France; FILNEMUS, Neuromuscular Rare Diseases Healthcare Professional Network, La Timone Hospital, CHU de Marseille, AP-HM, 13385 Marseille, France
| | - Savine Vicart
- Muscle Channelopathies Reference Centre, Neuro-Myology Department, Pitié-Salpêtrière University Hospital, AP-HP, Inserm UMR 974, Institute of Myology, Sorbonne University, 75013 Paris, France
| | - Jean-François Desaphy
- Department of Precision and Regenerative Medicine and Ionian Area, School of Medicine, University of Bari Aldo Moro, 70124 Bari, Italy
| | - Fabien Labombarda
- Cardiology Department, CHU de Caen, UR 4650, UNICAEN, 14000 Caen, France
| | | | - Jean-Claude Deharo
- Cardiology Department, La Timone Hospital, CHU de Marseille, AP-HM, 13385 Marseille, France; C2VN, Aix-Marseille Université, 13005 Marseille, France
| |
Collapse
|
2
|
Nikonova E, DeCata J, Canela M, Barz C, Esser A, Bouterwek J, Roy A, Gensler H, Heß M, Straub T, Forne I, Spletter ML. Bruno 1/CELF regulates splicing and cytoskeleton dynamics to ensure correct sarcomere assembly in Drosophila flight muscles. PLoS Biol 2024; 22:e3002575. [PMID: 38683844 PMCID: PMC11081514 DOI: 10.1371/journal.pbio.3002575] [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: 06/24/2023] [Revised: 05/09/2024] [Accepted: 03/04/2024] [Indexed: 05/02/2024] Open
Abstract
Muscles undergo developmental transitions in gene expression and alternative splicing that are necessary to refine sarcomere structure and contractility. CUG-BP and ETR-3-like (CELF) family RNA-binding proteins are important regulators of RNA processing during myogenesis that are misregulated in diseases such as Myotonic Dystrophy Type I (DM1). Here, we report a conserved function for Bruno 1 (Bru1, Arrest), a CELF1/2 family homolog in Drosophila, during early muscle myogenesis. Loss of Bru1 in flight muscles results in disorganization of the actin cytoskeleton leading to aberrant myofiber compaction and defects in pre-myofibril formation. Temporally restricted rescue and RNAi knockdown demonstrate that early cytoskeletal defects interfere with subsequent steps in sarcomere growth and maturation. Early defects are distinct from a later requirement for bru1 to regulate sarcomere assembly dynamics during myofiber maturation. We identify an imbalance in growth in sarcomere length and width during later stages of development as the mechanism driving abnormal radial growth, myofibril fusion, and the formation of hollow myofibrils in bru1 mutant muscle. Molecularly, we characterize a genome-wide transition from immature to mature sarcomere gene isoform expression in flight muscle development that is blocked in bru1 mutants. We further demonstrate that temporally restricted Bru1 rescue can partially alleviate hypercontraction in late pupal and adult stages, but it cannot restore myofiber function or correct structural deficits. Our results reveal the conserved nature of CELF function in regulating cytoskeletal dynamics in muscle development and demonstrate that defective RNA processing due to misexpression of CELF proteins causes wide-reaching structural defects and progressive malfunction of affected muscles that cannot be rescued by late-stage gene replacement.
Collapse
Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jenna DeCata
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
| | - Marc Canela
- Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Christiane Barz
- Muscle Dynamics Group, Max Planck Institute of Biochemistry, München, Germany
| | - Alexandra Esser
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jessica Bouterwek
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Akanksha Roy
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Heidemarie Gensler
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Martin Heß
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Tobias Straub
- Biomedical Center, Bioinformatics Core Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Ignasi Forne
- Biomedical Center, Protein Analysis Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Maria L. Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
| |
Collapse
|
3
|
Krause A, Anderson DG, Ferreira-Correia A, Dawson J, Baine-Savanhu F, Li PP, Margolis RL. Huntington disease-like 2: insight into neurodegeneration from an African disease. Nat Rev Neurol 2024; 20:36-49. [PMID: 38114648 DOI: 10.1038/s41582-023-00906-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2023] [Indexed: 12/21/2023]
Abstract
Huntington disease (HD)-like 2 (HDL2) is a rare genetic disease caused by an expanded trinucleotide repeat in the JPH3 gene (encoding junctophilin 3) that shows remarkable clinical similarity to HD. To date, HDL2 has been reported only in patients with definite or probable African ancestry. A single haplotype background is shared by patients with HDL2 from different populations, supporting a common African origin for the expansion mutation. Nevertheless, outside South Africa, reports of patients with HDL2 in Africa are scarce, probably owing to limited clinical services across the continent. Systematic comparisons of HDL2 and HD have revealed closely overlapping motor, cognitive and psychiatric features and similar patterns of cerebral and striatal atrophy. The pathogenesis of HDL2 remains unclear but it is proposed to occur through several mechanisms, including loss of protein function and RNA and/or protein toxicity. This Review summarizes our current knowledge of this African-specific HD phenocopy and highlights key areas of overlap between HDL2 and HD. Given the aforementioned similarities in clinical phenotype and pathology, an improved understanding of HDL2 could provide novel insights into HD and other neurodegenerative and/or trinucleotide repeat expansion disorders.
Collapse
Affiliation(s)
- Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - David G Anderson
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- University of Glasgow, Department of Neurology, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, UK
| | - Aline Ferreira-Correia
- Department of Psychology, School of Human and Community Development, Faculty of Humanities, University of the Witwatersrand, Johannesburg, South Africa
| | - Jessica Dawson
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Fiona Baine-Savanhu
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Pan P Li
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Russell L Margolis
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
4
|
Lidonnici D, Brambilla P, Ravasio R, Zozulya-Weidenfeller A, Beiderbeck A, van Aswegen M, Oliveira R, Sansone VA. Expert Insights from a Delphi-driven Neurologists' Panel: Real-world Mexiletine use in Patients with Myotonic Disorders in Italy. J Neuromuscul Dis 2024; 11:411-423. [PMID: 38306059 DOI: 10.3233/jnd-230115] [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] [Indexed: 02/03/2024]
Abstract
Background Myotonic disorders, such as non-dystrophic myotonias (NDMs) and myotonic dystrophies (DMs) are characterized by a delay in muscle relaxation after a contraction stimulus. There is general consensus that protocols to treat myotonia need to be implemented. Objective Mexiletine is the only pharmacological agent approved for the symptomatic treatment of myotonia in adult patients with NDM and is considered to be the first-line treatment for DMs; however, its production in Italy was halted in 2022 making its availability to patients problematic. Methods A panel of 8 Italian neurologists took part in a two-round Delphi panel between June and October 2022, analyzing the current use of mexiletine in Italian clinical practice. Results The panelists assist 1126 patients (69% DM type1, 18% NDM and 13% DM type2). Adult NDM patients receive, on average, 400-600 mg of mexiletine hydrochloride (HCl) while adult DM patients receive 100-600 mg, per day in the long-term. The severity of symptoms is considered the main reason to start mexiletine treatment for both NDM and DM patients. Mexiletine is reckoned to have a clinical impact for both NDM and DM patients, but currently drug access is problematic. Conclusions Mexiletine treatment is recognized to have a role in the reduction of the symptomatic burden for NDM and DM patients. Patient management could be improved by facilitating access to therapy and developing new drug formulations.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Valeria A Sansone
- The NEMO Center, Neurorehabilitation Unit, University of Milan, ASST Niguarda Hospital, Milan, Italy
| |
Collapse
|
5
|
Marzullo M, Coni S, De Simone A, Canettieri G, Ciapponi L. Modeling Myotonic Dystrophy Type 2 Using Drosophila melanogaster. Int J Mol Sci 2023; 24:14182. [PMID: 37762484 PMCID: PMC10532015 DOI: 10.3390/ijms241814182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/04/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Myotonic dystrophy 2 (DM2) is a genetic multi-systemic disease primarily affecting skeletal muscle. It is caused by CCTGn expansion in intron 1 of the CNBP gene, which encodes a zinc finger protein. DM2 disease has been successfully modeled in Drosophila melanogaster, allowing the identification and validation of new pathogenic mechanisms and potential therapeutic strategies. Here, we describe the principal tools used in Drosophila to study and dissect molecular pathways related to muscular dystrophies and summarize the main findings in DM2 pathogenesis based on DM2 Drosophila models. We also illustrate how Drosophila may be successfully used to generate a tractable animal model to identify novel genes able to affect and/or modify the pathogenic pathway and to discover new potential drugs.
Collapse
Affiliation(s)
- Marta Marzullo
- Department of Biology and Biotechnologies “C. Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (M.M.)
| | - Sonia Coni
- Department of Molecular Medicine, Sapienza University of Rome, 00161 Rome, Italy
| | - Assia De Simone
- Department of Biology and Biotechnologies “C. Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (M.M.)
| | - Gianluca Canettieri
- Department of Molecular Medicine, Sapienza University of Rome, 00161 Rome, Italy
- Istituto Pasteur Italia, Fondazione Cenci Bolognetti, 00161 Rome, Italy
| | - Laura Ciapponi
- Department of Biology and Biotechnologies “C. Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (M.M.)
| |
Collapse
|
6
|
Lutz M, Levanti M, Karns R, Gourdon G, Lindquist D, Timchenko NA, Timchenko L. Therapeutic Targeting of the GSK3β-CUGBP1 Pathway in Myotonic Dystrophy. Int J Mol Sci 2023; 24:10650. [PMID: 37445828 PMCID: PMC10342152 DOI: 10.3390/ijms241310650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is a neuromuscular disease associated with toxic RNA containing expanded CUG repeats. The developing therapeutic approaches to DM1 target mutant RNA or correct early toxic events downstream of the mutant RNA. We have previously described the benefits of the correction of the GSK3β-CUGBP1 pathway in DM1 mice (HSALR model) expressing 250 CUG repeats using the GSK3 inhibitor tideglusib (TG). Here, we show that TG treatments corrected the expression of ~17% of genes misregulated in DM1 mice, including genes involved in cell transport, development and differentiation. The expression of chloride channel 1 (Clcn1), the key trigger of myotonia in DM1, was also corrected by TG. We found that correction of the GSK3β-CUGBP1 pathway in mice expressing long CUG repeats (DMSXL model) is beneficial not only at the prenatal and postnatal stages, but also during adulthood. Using a mouse model with dysregulated CUGBP1, which mimics alterations in DM1, we showed that the dysregulated CUGBP1 contributes to the toxicity of expanded CUG repeats by changing gene expression and causing CNS abnormalities. These data show the critical role of the GSK3β-CUGBP1 pathway in DM1 muscle and in CNS pathologies, suggesting the benefits of GSK3 inhibitors in patients with different forms of DM1.
Collapse
Affiliation(s)
- Maggie Lutz
- Division of Neurology, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA; (M.L.); (M.L.)
| | - Miranda Levanti
- Division of Neurology, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA; (M.L.); (M.L.)
| | - Rebekah Karns
- Departments of Gastroenterology, Hepatology & Nutrition, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA;
| | - Genevieve Gourdon
- Sorbonne Université, Inserm, institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France;
| | - Diana Lindquist
- Imagine Research Center, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA;
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45221, USA;
| | - Nikolai A. Timchenko
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45221, USA;
- Department of Surgery, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA
| | - Lubov Timchenko
- Division of Neurology, Cincinnati Children’s Hospital, Cincinnati, OH 45229, USA; (M.L.); (M.L.)
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45221, USA;
| |
Collapse
|
7
|
Pluripotent Stem Cells in Disease Modeling and Drug Discovery for Myotonic Dystrophy Type 1. Cells 2023; 12:cells12040571. [PMID: 36831237 PMCID: PMC9954118 DOI: 10.3390/cells12040571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a progressive multisystemic disease caused by the expansion of a CTG repeat tract within the 3' untranslated region (3' UTR) of the dystrophia myotonica protein kinase gene (DMPK). Although DM1 is considered to be the most frequent myopathy of genetic origin in adults, DM1 patients exhibit a vast diversity of symptoms, affecting many different organs. Up until now, different in vitro models from patients' derived cells have largely contributed to the current understanding of DM1. Most of those studies have focused on muscle physiopathology. However, regarding the multisystemic aspect of DM1, there is still a crucial need for relevant cellular models to cover the whole complexity of the disease and open up options for new therapeutic approaches. This review discusses how human pluripotent stem cell-based models significantly contributed to DM1 mechanism decoding, and how they provided new therapeutic strategies that led to actual phase III clinical trials.
Collapse
|
8
|
Mishra SK, Hicks SM, Frias JA, Vangaveti S, Nakamori M, Cleary JD, Reddy K, Berglund JA. Quercetin selectively reduces expanded repeat RNA levels in models of myotonic dystrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526846. [PMID: 36778282 PMCID: PMC9915578 DOI: 10.1101/2023.02.02.526846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Myotonic dystrophy is a multisystemic neuromuscular disease caused by either a CTG repeat expansion in DMPK (DM1) or a CCTG repeat expansion in CNBP (DM2). Transcription of the expanded alleles produces toxic gain-of-function RNA that sequester the MBNL family of alternative splicing regulators into ribonuclear foci, leading to pathogenic mis-splicing. There are currently no approved treatments that target the root cause of disease which is the production of the toxic expansion RNA molecules. In this study, using our previously established HeLa DM1 repeat selective screening platform, we identified the natural product quercetin as a selective modulator of toxic RNA levels. Quercetin treatment selectively reduced toxic RNA levels and rescued MBNL dependent mis-splicing in DM1 and DM2 patient derived cell lines and in the HSALR transgenic DM1 mouse model where rescue of myotonia was also observed. Based on our data and its safety profile for use in humans, we have identified quercetin as a priority disease-targeting therapeutic lead for clinical evaluation for the treatment of DM1 and DM2.
Collapse
Affiliation(s)
- Subodh K. Mishra
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Sawyer M. Hicks
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Jesus A. Frias
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Sweta Vangaveti
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine; Osaka, Japan, 565-0871
| | - John D. Cleary
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Kaalak Reddy
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - J. Andrew Berglund
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| |
Collapse
|
9
|
Di Leo V, Lawless C, Roussel MP, Gomes TB, Gorman GS, Russell OM, Tuppen HA, Duchesne E, Vincent AE. Resistance Exercise Training Rescues Mitochondrial Dysfunction in Skeletal Muscle of Patients with Myotonic Dystrophy Type 1. J Neuromuscul Dis 2023; 10:1111-1126. [PMID: 37638448 PMCID: PMC10657683 DOI: 10.3233/jnd-230099] [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] [Accepted: 08/08/2023] [Indexed: 08/29/2023]
Abstract
BACKGROUND Myotonic dystrophy type 1 (DM1) is a dominant autosomal neuromuscular disorder caused by the inheritance of a CTG triplet repeat expansion in the Dystrophia Myotonica Protein Kinase (DMPK) gene. At present, no cure currently exists for DM1 disease. OBJECTIVE This study investigates the effects of 12-week resistance exercise training on mitochondrial oxidative phosphorylation in skeletal muscle in a cohort of DM1 patients (n = 11, men) in comparison to control muscle with normal oxidative phosphorylation. METHODS Immunofluorescence was used to assess protein levels of key respiratory chain subunits of complex I (CI) and complex IV (CIV), and markers of mitochondrial mass and cell membrane in individual myofibres sampled from muscle biopsies. Using control's skeletal muscle fibers population, we classified each patient's fibers as having normal, low or high levels of CI and CIV and compared the proportions of fibers before and after exercise training. The significance of changes observed between pre- and post-exercise within patients was estimated using a permutation test. RESULTS At baseline, DM1 patients present with significantly decreased mitochondrial mass, and isolated or combined CI and CIV deficiency. After resistance exercise training, in most patients a significant increase in mitochondrial mass was observed, and all patients showed a significant increase in CI and/or CIV protein levels. Moreover, improvements in mitochondrial mass were correlated with the one-repetition maximum strength evaluation. CONCLUSIONS Remarkably, 12-week resistance exercise training is sufficient to partially rescue mitochondrial dysfunction in DM1 patients, suggesting that the response to exercise is in part be due to changes in mitochondria.
Collapse
Affiliation(s)
- Valeria Di Leo
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, England
| | - Conor Lawless
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
| | - Marie-Pier Roussel
- Department of Fundamental Sciences, Université du Québec à Chicoutimi, Quebec, Canada
| | - Tiago B. Gomes
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Gráinne S. Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, England
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Royal Victoria Infirmary, Newcastle Upon Tyne, UK
| | - Oliver M. Russell
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, England
| | - Helen A.L. Tuppen
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
| | - Elise Duchesne
- Department of Health Sciences, Université du Québec à Chicoutimi, Québec, Canada
- Neuromuscular Diseases Interdisciplinary Research Group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
| | - Amy E. Vincent
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University, Newcastle upon Tyne, England
| |
Collapse
|