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Hamm SE, Yuan C, McQueen LF, Wallace MA, Zhang H, Arora A, Garafalo AM, McMillan RP, Lawlor MW, Prom MJ, Ott EM, Yan J, Addington AK, Morris CA, Gonzalez JP, Grange RW. Prolonged voluntary wheel running reveals unique adaptations in mdx mice treated with microdystrophin constructs ± the nNOS-binding site. Front Physiol 2023; 14:1166206. [PMID: 37435312 PMCID: PMC10330712 DOI: 10.3389/fphys.2023.1166206] [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: 02/14/2023] [Accepted: 05/10/2023] [Indexed: 07/13/2023] Open
Abstract
We tested the effects of prolonged voluntary wheel running on the muscle function of mdx mice treated with one of two different microdystrophin constructs. At 7 weeks of age mdx mice were injected with a single dose of AAV9-CK8-microdystrophin with (gene therapy 1, GT1) or without (gene therapy 2, GT2) the nNOS-binding domain and were assigned to one of four gene therapy treated groups: mdxRGT1 (run, GT1), mdxGT1 (no run, GT1), or mdxRGT2 (run,GT2), mdxGT2 (no run, GT2). There were two mdx untreated groups injected with excipient: mdxR (run, no gene therapy) and mdx (no run, no gene therapy). A third no treatment group, Wildtype (WT) received no injection and did not run. mdxRGT1, mdxRGT2 and mdxR performed voluntary wheel running for 52 weeks; WT and remaining mdx groups were cage active. Robust expression of microdystrophin occurred in diaphragm, quadriceps, and heart muscles of all treated mice. Dystrophic muscle pathology was high in diaphragms of non-treated mdx and mdxR mice and improved in all treated groups. Endurance capacity was rescued by both voluntary wheel running and gene therapy alone, but their combination was most beneficial. All treated groups increased in vivo plantarflexor torque over both mdx and mdxR mice. mdx and mdxR mice displayed ∼3-fold lower diaphragm force and power compared to WT values. Treated groups demonstrated partial improvements in diaphragm force and power, with mdxRGT2 mice experiencing the greatest improvement at ∼60% of WT values. Evaluation of oxidative red quadriceps fibers revealed the greatest improvements in mitochondrial respiration in mdxRGT1 mice, reaching WT levels. Interestingly, mdxGT2 mice displayed diaphragm mitochondrial respiration values similar to WT but mdxRGT2 animals showed relative decreases compared to the no run group. Collectively, these data demonstrate that either microdystrophin construct combined with voluntary wheel running increased in vivo maximal muscle strength, power, and endurance. However, these data also highlighted important differences between the two microdystrophin constructs. GT1, with the nNOS-binding site, improved more markers of exercise-driven adaptations in metabolic enzyme activity of limb muscles, while GT2, without the nNOS-binding site, demonstrated greater protection of diaphragm strength after chronic voluntary endurance exercise but decreased mitochondrial respiration in the context of running.
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Affiliation(s)
- S. E. Hamm
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - C. Yuan
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - L. F. McQueen
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - M. A. Wallace
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - H. Zhang
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - A. Arora
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - A. M. Garafalo
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - R. P. McMillan
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - M. W. Lawlor
- Department of Pathology and Neuroscience Research Center, Medical College of Wisconsin and Diverge Translational Science Laboratory, Milwaukee, WI, United States
| | - M. J. Prom
- Department of Pathology and Neuroscience Research Center, Medical College of Wisconsin and Diverge Translational Science Laboratory, Milwaukee, WI, United States
| | - E. M. Ott
- Department of Pathology and Neuroscience Research Center, Medical College of Wisconsin and Diverge Translational Science Laboratory, Milwaukee, WI, United States
| | - J. Yan
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - A. K. Addington
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
| | - C. A. Morris
- Solid Biosciences, Inc., Cambridge, MA, United States
| | | | - R. W. Grange
- Department of Human Nutrition, Foods and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA, United States
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Su Y, Song Y. The new challenge of “exercise + X″ therapy for Duchenne muscular dystrophy—Individualized identification of exercise tolerance and precise implementation of exercise intervention. Front Physiol 2022; 13:947749. [PMID: 35991169 PMCID: PMC9389311 DOI: 10.3389/fphys.2022.947749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/07/2022] [Indexed: 12/05/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive fatal muscular disease. Gene therapy, cell therapy, and drug therapy are currently the most widely used treatments for DMD. However, many experiments on animals and humans suggested that appropriate exercise could improve the effectiveness of such precision medicine treatment, thereby improving patient’s muscle quality and function. Due to the striated muscle damage of DMD individuals, there are still many debates about whether DMD animals or patients can exercise, how to exercise, when to exercise best, and how to exercise effectively. The purpose of this review is to summarize and investigate the scientific basis and efficacy of exercise as an adjuvant therapy for DMD gene therapy, cell therapy and drug therapy, as well as to present the theoretical framework and optional strategies of “exercise + X″″ combination therapy.
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Affiliation(s)
- Yuhui Su
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
- Institute of Physical Education, Jilin Normal University, Siping, China
| | - Yafeng Song
- China Institute of Sport and Health Science, Beijing Sport University, Beijing, China
- *Correspondence: Yafeng Song,
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Accelerating the Mdx Heart Histo-Pathology through Physical Exercise. Life (Basel) 2021; 11:life11070706. [PMID: 34357078 PMCID: PMC8306456 DOI: 10.3390/life11070706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 02/06/2023] Open
Abstract
Chronic cardiac muscle inflammation and fibrosis are key features of Duchenne Muscular Dystrophy (DMD). Around 90% of 18-year-old patients already show signs of DMD-related cardiomyopathy, and cardiac failure is rising as the main cause of death among DMD patients. The evaluation of novel therapies for the treatment of dystrophic heart problems depends on the availability of animal models that closely mirror the human pathology. The widely used DMD animal model, the mdx mouse, presents a milder cardiac pathology compared to humans, with a late onset, which precludes large-scale and reliable studies. In this study, we used an exercise protocol to accelerate and worsen the cardiac pathology in mdx mice. The mice were subjected to a 1 h-long running session on a treadmill, at moderate speed, twice a week for 8 weeks. We demonstrate that subjecting young mdx mice (4-week-old) to "endurance" exercise accelerates heart pathology progression, as shown by early fibrosis deposition, increases necrosis and inflammation, and reduces heart function compared to controls. We believe that our exercised mdx model represents an easily reproducible and useful tool to study the molecular and cellular networks involved in dystrophic heart alterations, as well as to evaluate novel therapeutic strategies aimed at ameliorating dystrophic heart pathology.
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Florczyk-Soluch U, Polak K, Dulak J. The multifaceted view of heart problem in Duchenne muscular dystrophy. Cell Mol Life Sci 2021; 78:5447-5468. [PMID: 34091693 PMCID: PMC8257522 DOI: 10.1007/s00018-021-03862-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/29/2021] [Accepted: 05/20/2021] [Indexed: 12/14/2022]
Abstract
Dystrophin is a large protein serving as local scaffolding repetitively bridging cytoskeleton and the outside of striated muscle cell. As such dystrophin is a critical brick primarily in dystrophin-associated protein complex (DAGC) and in a larger submembranous unit, costamere. Accordingly, the lack of functional dystrophin laying at the root of Duchenne muscular dystrophy (DMD) drives sarcolemma instability. From this point on, the cascade inevitably leading to the death of myocyte begins. In cardiomyocytes, intracellular calcium overload and related mitochondrial-mediated cell death mainly contribute to myocardial dysfunction and dilation while other protein dysregulation and/or mislocalization may affect electrical conduction system and favor arrhythmogenesis. Although clinically DMD manifests as progressive muscle weakness and skeletal muscle symptoms define characteristic of DMD, it is the heart problem the biggest challenge that most often develop in the form of dilated cardiomyopathy (DCM). Current standards of treatment and recent progress in respiratory care, introduced in most settings in the 1990s, have improved quality of life and median life expectancy to 4th decade of patient's age. At the same time, cardiac causes of death related to DMD increases. Despite preventive and palliative cardiac treatments available, the prognoses remain poor. Direct therapeutic targeting of dystrophin deficiency is critical, however, hindered by the large size of the dystrophin cDNA and/or stochastic, often extensive genetic changes in DMD gene. The correlation between cardiac involvement and mutations affecting specific dystrophin isoforms, may provide a mutation-specific cardiac management and novel therapeutic approaches for patients with CM. Nonetheless, the successful cardiac treatment poses a big challenge and may require combined therapy to combat dystrophin deficiency and its after-effects (critical in DMD pathogenesis). This review locates the multifaceted heart problem in the course of DMD, balancing the insights into basic science, translational efforts and clinical manifestation of dystrophic heart disease.
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Affiliation(s)
- Urszula Florczyk-Soluch
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
| | - Katarzyna Polak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Józef Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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Beneficial Role of Exercise in the Modulation of mdx Muscle Plastic Remodeling and Oxidative Stress. Antioxidants (Basel) 2021; 10:antiox10040558. [PMID: 33916762 PMCID: PMC8066278 DOI: 10.3390/antiox10040558] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/02/2021] [Accepted: 03/15/2021] [Indexed: 12/15/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive progressive lethal disorder caused by the lack of dystrophin, which determines myofibers mechanical instability, oxidative stress, inflammation, and susceptibility to contraction-induced injuries. Unfortunately, at present, there is no efficient therapy for DMD. Beyond several promising gene- and stem cells-based strategies under investigation, physical activity may represent a valid noninvasive therapeutic approach to slow down the progression of the pathology. However, ethical issues, the limited number of studies in humans and the lack of consistency of the investigated training interventions generate loss of consensus regarding their efficacy, leaving exercise prescription still questionable. By an accurate analysis of data about the effects of different protocol of exercise on muscles of mdx mice, the most widely-used pre-clinical model for DMD research, we found that low intensity exercise, especially in the form of low speed treadmill running, likely represents the most suitable exercise modality associated to beneficial effects on mdx muscle. This protocol of training reduces muscle oxidative stress, inflammation, and fibrosis process, and enhances muscle functionality, muscle regeneration, and hypertrophy. These conclusions can guide the design of appropriate studies on human, thereby providing new insights to translational therapeutic application of exercise to DMD patients.
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Hamm SE, Fathalikhani DD, Bukovec KE, Addington AK, Zhang H, Perry JB, McMillan RP, Lawlor MW, Prom MJ, Vanden Avond MA, Kumar SN, Coleman KE, Dupont JB, Mack DL, Brown DA, Morris CA, Gonzalez JP, Grange RW. Voluntary wheel running complements microdystrophin gene therapy to improve muscle function in mdx mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 21:144-160. [PMID: 33850950 PMCID: PMC8020351 DOI: 10.1016/j.omtm.2021.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 02/25/2021] [Indexed: 12/12/2022]
Abstract
We tested the hypothesis that voluntary wheel running would complement microdystrophin gene therapy to improve muscle function in young mdx mice, a model of Duchenne muscular dystrophy. mdx mice injected with a single dose of AAV9-CK8-microdystrophin or vehicle at age 7 weeks were assigned to three groups: mdxRGT (run, gene therapy), mdxGT (no run, gene therapy), or mdx (no run, no gene therapy). Wild-type (WT) mice were assigned to WTR (run) and WT (no run) groups. WTR and mdxRGT performed voluntary wheel running for 21 weeks; remaining groups were cage active. Robust expression of microdystrophin occurred in heart and limb muscles of treated mice. mdxRGT versus mdxGT mice showed increased microdystrophin in quadriceps but decreased levels in diaphragm. mdx final treadmill fatigue time was depressed compared to all groups, improved in mdxGT, and highest in mdxRGT. Both weekly running distance (km) and final treadmill fatigue time for mdxRGT and WTR were similar. Remarkably, mdxRGT diaphragm power was only rescued to 60% of WT, suggesting a negative impact of running. However, potential changes in fiber type distribution in mdxRGT diaphragms could indicate an adaptation to trade power for endurance. Post-treatment in vivo maximal plantar flexor torque relative to baseline values was greater for mdxGT and mdxRGT versus all other groups. Mitochondrial respiration rates from red quadriceps fibers were significantly improved in mdxGT animals, but the greatest bioenergetic benefit was observed in the mdxRGT group. Additional assessments revealed partial to full functional restoration in mdxGT and mdxRGT muscles relative to WT. These data demonstrate that voluntary wheel running combined with microdystrophin gene therapy in young mdx mice improved whole-body performance, affected muscle function differentially, mitigated energetic deficits, but also revealed some detrimental effects of exercise. With microdystrophin gene therapy currently in clinical trials, these data may help us understand the potential impact of exercise in treated patients.
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Affiliation(s)
- Shelby E Hamm
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Daniel D Fathalikhani
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Katherine E Bukovec
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Adele K Addington
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Haiyan Zhang
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Justin B Perry
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Ryan P McMillan
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | - Michael W Lawlor
- Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Mariah J Prom
- Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Mark A Vanden Avond
- Department of Pathology and Laboratory Medicine and Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Suresh N Kumar
- Department of Pathology and Laboratory Medicine and Children's Hospital of Wisconsin Research Institute Imaging Core, Milwaukee, WI 53226, USA
| | - Kirsten E Coleman
- Powell Gene Therapy Center Toxicology Core, University of Florida, Gainesville, FL 32610, USA
| | - J B Dupont
- Translational Gene Therapy for Genetic Diseases, INSERM UMR1089, IRS2 Nantes Biotech, Université de Nantes, Nantes 44200, France
| | - David L Mack
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98104, USA.,Institute for Stem Cell and Regenerative Medicine, School of Medicine, University of Washington, Seattle, WA 98107, USA
| | - David A Brown
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
| | | | | | - Robert W Grange
- Department of Human Nutrition, Foods, and Exercise and Metabolism Core, Virginia Tech, Blacksburg, VA 24060, USA
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Nagai M, Awano H, Yamamoto T, Bo R, Matsuo M, Iijima K. The ACTN3 577XX Null Genotype Is Associated with Low Left Ventricular Dilation-Free Survival Rate in Patients with Duchenne Muscular Dystrophy. J Card Fail 2020; 26:841-848. [DOI: 10.1016/j.cardfail.2020.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 07/09/2020] [Accepted: 08/06/2020] [Indexed: 11/28/2022]
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Kolwicz SC, Hall JK, Moussavi-Harami F, Chen X, Hauschka SD, Chamberlain JS, Regnier M, Odom GL. Gene Therapy Rescues Cardiac Dysfunction in Duchenne Muscular Dystrophy Mice by Elevating Cardiomyocyte Deoxy-Adenosine Triphosphate. JACC Basic Transl Sci 2019; 4:778-791. [PMID: 31998848 PMCID: PMC6978556 DOI: 10.1016/j.jacbts.2019.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 01/13/2023]
Abstract
Mutations in the gene encoding for dystrophin leads to structural and functional deterioration of cardiomyocytes and is a hallmark of cardiomyopathy in Duchenne muscular dystrophy (DMD) patients. Administration of recombinant adeno-associated viral vectors delivering microdystrophin or ribonucleotide reductase (RNR), under muscle-specific regulatory control, rescues both baseline and high workload-challenged hearts in an aged, DMD mouse model. However, only RNR treatments improved both systolic and diastolic function under those conditions. Cardiac-specific recombinant adeno-associated viral treatment of RNR holds therapeutic promise for improvement of cardiomyopathy in DMD patients.
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Key Words
- CK8, miniaturized murine creatine kinase regulatory cassette
- CMV, cytomegalovirus
- DMD, Duchenne muscular dystrophy
- RNR, ribonucleotide reductase
- cTnT, cardiac troponin T
- cardiomyopathy
- dADP, deoxy-adenosine diphosphate
- dATP, deoxy-adenosine triphosphate
- diastolic dysfunction
- dystrophin
- mdx, mouse muscular dystrophy model
- rAAV, recombinant adeno-associated viral vector
- recombinant adeno-associated virus vectors
- ribonucleotide reductase
- μDys, microdystrophin
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Affiliation(s)
- Stephen C. Kolwicz
- Mitochondria and Metabolism Center, University of Washington, Seattle, Washington
| | - John K. Hall
- Department of Neurology, University of Washington, Seattle, Washington
| | - Farid Moussavi-Harami
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington
| | - Xiolan Chen
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Stephen D. Hauschka
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Michael Regnier
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
- Department of Bioengineering, University of Washington, Seattle, Washington
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington
| | - Guy L. Odom
- Department of Neurology, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington
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Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is a neuromuscular disease caused by a dystrophin protein deficiency. Dystrophin functions to stabilize and protect the muscle fiber during muscle contraction; thus, the absence of functional dystrophin protein leads to muscle injury. DMD patients experience progressive muscle necrosis, loss of function, and ultimately succumb to respiratory failure or cardiomyopathy. Exercise is known to improve muscle health and strength in healthy individuals as well as positively affect other systems. Because of this, exercise has been investigated as a potential therapeutic approach for DMD. METHODS This review aims to provide a concise presentation of the exercise literature with a focus on dystrophin-deficient muscle. Our intent was to identify trends and gaps in knowledge with an appreciation of exercise modality. RESULTS After compiling data from mouse and human studies, it became apparent that endurance exercises such as a swimming and voluntary wheel running have therapeutic potential in limb muscles of mice and respiratory training was beneficial in humans. However, in the comparatively few long-term investigations, the effect of low-intensity training on cardiac and respiratory muscles was contradictory. In addition, the effect of exercise on other systems is largely unknown. CONCLUSIONS To safely prescribe exercise as a therapy to DMD patients, multisystemic investigations are needed including the evaluation of respiratory and cardiac muscle.
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Voluntary exercise improves muscle function and does not exacerbate muscle and heart pathology in aged Duchenne muscular dystrophy mice. J Mol Cell Cardiol 2018; 125:29-38. [PMID: 30336143 DOI: 10.1016/j.yjmcc.2018.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/21/2018] [Accepted: 10/08/2018] [Indexed: 12/31/2022]
Abstract
Duchenne muscular dystrophy is a severe muscle wasting disease, characterized by a severely reduced lifespan in which cardiomyopathy is one of the leading causes of death. Multiple therapies aiming at dystrophin restoration have been approved. It is anticipated that these therapies will maintain muscle function for longer and extend the ambulatory period, which in turn will increase the cardiac workload which could be detrimental for cardiac function. We investigated the effects of voluntary running exercise in combination with low dystrophin levels on function and pathology of skeletal muscle and heart. We divided 15.5-month old female mdx (no dystrophin), mdx-XistΔhs (varying low dystrophin levels) and wild type mice (BL10-WT and XistΔhs-WT) to either a sedentary or voluntary wheel running regime and assessed muscle function at 17.5 months of age. Thereafter, a cardiac MRI was obtained, and muscle and heart histopathology were assessed. We show that voluntary exercise is beneficial to skeletal muscle and heart function in dystrophic mice while not affecting muscle pathology. Low amounts of dystrophin further improve skeletal muscle and cardiac function. These findings suggest that voluntary exercise may be beneficial for skeletal muscle and heart in DMD patients, especially in conjunction with low amounts of dystrophin.
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AAV9-mediated gene transfer of desmin ameliorates cardiomyopathy in desmin-deficient mice. Gene Ther 2016; 23:673-9. [PMID: 27101257 PMCID: PMC4976287 DOI: 10.1038/gt.2016.40] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 03/23/2016] [Accepted: 04/05/2016] [Indexed: 11/23/2022]
Abstract
Mutations of the human desmin (DES) gene cause autosomal dominant and recessive myopathies affecting skeletal and cardiac muscle tissue. Desmin knockout mice (DES-KO), which develop progressive myopathy and cardiomyopathy, mirror rare human recessive desminopathies in which mutations on both DES alleles lead to a complete ablation of desmin protein expression. Here, we investigated whether an adeno-associated virus-mediated gene transfer of wild-type desmin cDNA (AAV-DES) attenuates cardiomyopathy in these mice. Our approach leads to a partial reconstitution of desmin protein expression and the de novo formation of the extrasarcomeric desmin–syncoilin network in cardiomyocytes of treated animals. This finding was accompanied by reduced fibrosis and heart weights and improved systolic left-ventricular function when compared with control vector-treated DES-KO mice. Since the re-expression of desmin protein in cardiomyocytes of DES-KO mice restores the extrasarcomeric desmin–syncoilin cytoskeleton, attenuates the degree of cardiac hypertrophy and fibrosis, and improves contractile function, AAV-mediated desmin gene transfer may be a novel and promising therapeutic approach for patients with cardiomyopathy due to the complete lack of desmin protein expression.
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Barbin ICC, Pereira JA, Bersan Rovere M, de Oliveira Moreira D, Marques MJ, Santo Neto H. Diaphragm degeneration and cardiac structure in mdx mouse: potential clinical implications for Duchenne muscular dystrophy. J Anat 2016; 228:784-91. [PMID: 26822140 DOI: 10.1111/joa.12443] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2015] [Indexed: 02/03/2023] Open
Abstract
We examined the effects of exercise on diaphragm degeneration and cardiomyopathy in dystrophin-deficient mdx mice. Mdx mice (11 months of age) were exercised (swimming) for 2 months to worsen diaphragm degeneration. Control mdx mice were kept sedentary. Morphological evaluation demonstrated increased fibrosis in the diaphragm of exercised mdx mice (33.3 ± 6.0% area of fibrosis) compared with control mdx mice (20.9 ± 1.7% area of fibrosis). Increased (26%) activity of MMP-2, a marker of fibrosis, was detected in the diaphragms from exercised mdx mice. Morphological evaluation of the heart demonstrated a 45% increase in fibrosis in the right ventricle (8.3 ± 0.6% in sedentary vs. 12.0 ± 0.6% of fibrosis in exercised) and in the left ventricle (35% increase) in the exercised mdx mice. The density of inflammatory cells-degenerating cardiomyocytes increased 95% in the right ventricle (2.3 ± 0.6 in sedentary vs. 4.5 ± 0.8 in exercised) and 71% in the left ventricle (1.4 ± 0.6 sedentary vs. 2.4 ± 0.5 exercised). The levels of both active MMP-2 and the pro-fibrotic factor transforming growth factor beta were elevated in the hearts of exercised compared with sedentary mdx mice. The wall thickness to lumen diameter ratio of the pulmonary trunk was significantly increased in the exercised mdx mice (0.11 ± 0.04 in sedentary vs. 0.28 ± 0.12 in exercised), as was the thickness of the right ventricle wall, which suggests the occurrence of pulmonary hypertension in those animals. It is suggested that diaphragm degeneration is a main contributor to right ventricle dystrophic pathology. These findings may be relevant for future interventional studies for Duchenne muscular dystrophy-associated cardiomyopathy.
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Affiliation(s)
- Isabel Cristina Chagas Barbin
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Juliano Alves Pereira
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Matheus Bersan Rovere
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Drielen de Oliveira Moreira
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Maria Julia Marques
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Humberto Santo Neto
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Hyzewicz J, Ruegg UT, Takeda S. Comparison of Experimental Protocols of Physical Exercise for mdx Mice and Duchenne Muscular Dystrophy Patients. J Neuromuscul Dis 2015; 2:325-342. [PMID: 27858750 PMCID: PMC5240598 DOI: 10.3233/jnd-150106] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Duchenne Muscular Dystrophy (DMD) is caused by mutations in the gene coding for dystrophin and leads to muscle degeneration, wheelchair dependence and death by cardiac or respiratory failure. Physical exercise has been proposed as a palliative therapy for DMD to maintain muscle strength and prevent contractures for as long as possible. However, its practice remains controversial because the benefits of training may be counteracted by muscle overuse and damage. The effects of physical exercise have been investigated in muscles of dystrophin-deficient mdx mice and in patients with DMD. However, a lack of uniformity among protocols limits comparability between studies and translatability of results from animals to humans. In the present review, we summarize and discuss published protocols used to investigate the effects of physical exercise on mdx mice and DMD patients, with the objectives of improving comparability between studies and identifying future research directions.
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Affiliation(s)
- Janek Hyzewicz
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | | | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
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Uryash A, Bassuk J, Kurlansky P, Altamirano F, Lopez JR, Adams JA. Antioxidant Properties of Whole Body Periodic Acceleration (pGz). PLoS One 2015; 10:e0131392. [PMID: 26133377 PMCID: PMC4489838 DOI: 10.1371/journal.pone.0131392] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 06/02/2015] [Indexed: 11/30/2022] Open
Abstract
The recognition that oxidative stress is a major component of several chronic diseases has engendered numerous trials of antioxidant therapies with minimal or no direct benefits. Nanomolar quantities of nitric oxide released into the circulation by pharmacologic stimulation of eNOS have antioxidant properties but physiologic stimulation as through increased pulsatile shear stress of the endothelium has not been assessed. The present study utilized a non-invasive technology, periodic acceleration (pGz) that increases pulsatile shear stress such that upregulation of cardiac eNOS occurs, We assessed its efficacy in normal mice and mouse models with high levels of oxidative stress, e.g. Diabetes type 1 and mdx (Duchene Muscular Dystrophy). pGz increased protein expression and upregulated eNOS in hearts. Application of pGz was associated with significantly increased expression of endogenous antioxidants (Glutathioneperoxidase-1(GPX-1), Catalase (CAT), Superoxide, Superoxide Dismutase 1(SOD1). This led to an increase of total cardiac antioxidant capacity along with an increase in the antioxidant response element transcription factor Nrf2 translocation to the nucleus. pGz decreased reactive oxygen species in both mice models of oxidative stress. Thus, pGz is a novel non-pharmacologic method to harness endogenous antioxidant capacity.
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Affiliation(s)
- Arkady Uryash
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
| | - Jorge Bassuk
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
| | - Paul Kurlansky
- Department of Surgery, Columbia University, New York, New York, United States of America
| | - Francisco Altamirano
- Department of Molecular Biosciences, University of California Davis, Davis, California, United States of America
| | - Jose R. Lopez
- Department of Molecular Biosciences, University of California Davis, Davis, California, United States of America
| | - Jose A. Adams
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, Florida, United States of America
- * E-mail:
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Implications for Cardiac Function Following Rescue of the Dystrophic Diaphragm in a Mouse Model of Duchenne Muscular Dystrophy. Sci Rep 2015; 5:11632. [PMID: 26113184 PMCID: PMC4586900 DOI: 10.1038/srep11632] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/27/2015] [Indexed: 01/16/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by absence of the integral structural protein, dystrophin, which renders muscle fibres susceptible to injury and degeneration. This ultimately results in cardiorespiratory dysfunction, which is the predominant cause of death in DMD patients, and highlights the importance of therapeutic targeting of the cardiorespiratory system. While there is some evidence to suggest that restoring dystrophin in the diaphragm improves both respiratory and cardiac function, the role of the diaphragm is not well understood. Here using exon skipping oligonucleotides we predominantly restored dystrophin in the diaphragm and assessed cardiac function by MRI. This approach reduced diaphragmatic pathophysiology and markedly improved diaphragm function but did not improve cardiac function or pathophysiology, with or without exercise. Interestingly, exercise resulted in a reduction of dystrophin protein and exon skipping in the diaphragm. This suggests that treatment regimens may require modification in more active patients. In conclusion, whilst the diaphragm is an important respiratory muscle, it is likely that dystrophin needs to be restored in other tissues, including multiple accessory respiratory muscles, and of course the heart itself for appropriate therapeutic outcomes. This supports the requirement of a body-wide therapy to treat DMD.
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Guiraud S, Squire SE, Edwards B, Chen H, Burns DT, Shah N, Babbs A, Davies SG, Wynne GM, Russell AJ, Elsey D, Wilson FX, Tinsley JM, Davies KE. Second-generation compound for the modulation of utrophin in the therapy of DMD. Hum Mol Genet 2015; 24:4212-24. [PMID: 25935002 PMCID: PMC4492389 DOI: 10.1093/hmg/ddv154] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/27/2015] [Indexed: 01/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. There is currently no cure for DMD although various promising approaches are progressing through human clinical trials. By pharmacologically modulating the expression of the dystrophin-related protein utrophin, we have previously demonstrated in dystrophin-deficient mdx studies, daily SMT C1100 treatment significantly reduced muscle degeneration leading to improved muscle function. This manuscript describes the significant disease modifying benefits associated with daily dosing of SMT022357, a second-generation compound in this drug series with improved physicochemical properties and a more robust metabolism profile. These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles. Significantly, utrophin expression is localized along the length of the muscle fibre, not just at the synapse, and is fibre-type independent, suggesting that drug treatment is modulating utrophin transcription in extra-synaptic myonuclei. This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis. All these improvements combine to protect the mdx muscle from contraction induced damage and enhance physiological function. This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation.
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Affiliation(s)
- Simon Guiraud
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK,
| | - Sarah E Squire
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Benjamin Edwards
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Huijia Chen
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - David T Burns
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Nandini Shah
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Arran Babbs
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Stephen G Davies
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Graham M Wynne
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Angela J Russell
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3PT, UK and
| | - David Elsey
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Francis X Wilson
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Jon M Tinsley
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Kay E Davies
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK,
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Betts CA, Saleh AF, Carr CA, Hammond SM, Coenen-Stass AML, Godfrey C, McClorey G, Varela MA, Roberts TC, Clarke K, Gait MJ, Wood MJA. Prevention of exercised induced cardiomyopathy following Pip-PMO treatment in dystrophic mdx mice. Sci Rep 2015; 5:8986. [PMID: 25758104 PMCID: PMC4355666 DOI: 10.1038/srep08986] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 02/03/2015] [Indexed: 01/16/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disorder caused by mutations in the Dmd gene. In addition to skeletal muscle wasting, DMD patients develop cardiomyopathy, which significantly contributes to mortality. Antisense oligonucleotides (AOs) are a promising DMD therapy, restoring functional dystrophin protein by exon skipping. However, a major limitation with current AOs is the absence of dystrophin correction in heart. Pip peptide-AOs demonstrate high activity in cardiac muscle. To determine their therapeutic value, dystrophic mdx mice were subject to forced exercise to model the DMD cardiac phenotype. Repeated peptide-AO treatments resulted in high levels of cardiac dystrophin protein, which prevented the exercised induced progression of cardiomyopathy, normalising heart size as well as stabilising other cardiac parameters. Treated mice also exhibited significantly reduced cardiac fibrosis and improved sarcolemmal integrity. This work demonstrates that high levels of cardiac dystrophin restored by Pip peptide-AOs prevents further deterioration of cardiomyopathy and pathology following exercise in dystrophic DMD mice.
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Affiliation(s)
- Corinne A Betts
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Amer F Saleh
- 1] Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK [2] AstraZeneca R&D, Discovery Safety, Drug safety and Metabolism, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Carolyn A Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Suzan M Hammond
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Anna M L Coenen-Stass
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Caroline Godfrey
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Graham McClorey
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Miguel A Varela
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Thomas C Roberts
- 1] Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX [2] Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 NTorrey Pines Road, La Jolla, CA 92037, USA
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
| | - Michael J Gait
- Medical Research Council, Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, UK, OX1 3QX
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Low dystrophin levels in heart can delay heart failure in mdx mice. J Mol Cell Cardiol 2014; 69:17-23. [PMID: 24486194 DOI: 10.1016/j.yjmcc.2014.01.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/25/2013] [Accepted: 01/21/2014] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy is caused by mutations that prevent synthesis of functional dystrophin. All patients develop dilated cardiomyopathy. Promising therapeutic approaches are underway that successfully restore dystrophin expression in skeletal muscle. However, their efficiency in the heart is limited. Improved quality and function of only skeletal muscle potentially accelerate the development of cardiomyopathy. Our study aimed to elucidate which dystrophin levels in the heart are required to prevent or delay cardiomyopathy in mice. Heart function and pathology assessed with magnetic resonance imaging and histopathological analysis were compared between 2, 6 and 10-month-old female mdx-Xist(Δhs) mice, expressing low dystrophin levels (3-15%) in a mosaic manner based on skewed X-inactivation, dystrophin-negative mdx mice, and wild type mice of corresponding genetic backgrounds and gender. With age mdx mice developed dilated cardiomyopathy and hypertrophy, whereas the onset of heart pathology was delayed and function improved in mdx-Xist(Δhs) mice. The ejection fraction, the most severely affected parameter for both ventricles, correlated to dystrophin expression and the percentage of fibrosis. Fibrosis was partly reduced from 9.8% in mdx to 5.4% in 10 month old mdx-Xist(Δhs) mice. These data suggest that mosaic expression of 4-15% dystrophin in the heart is sufficient to delay the onset and ameliorate cardiomyopathy in mice.
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Selsby JT, Acosta P, Sleeper MM, Barton ER, Sweeney HL. Long-term wheel running compromises diaphragm function but improves cardiac and plantarflexor function in the mdx mouse. J Appl Physiol (1985) 2013; 115:660-6. [PMID: 23823150 DOI: 10.1152/japplphysiol.00252.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Dystrophin-deficient muscles suffer from free radical injury, mitochondrial dysfunction, apoptosis, and inflammation, among other pathologies that contribute to muscle fiber injury and loss, leading to wheelchair confinement and death in the patient. For some time, it has been appreciated that endurance training has the potential to counter many of these contributing factors. Correspondingly, numerous investigations have shown improvements in limb muscle function following endurance training in mdx mice. However, the effect of long-term volitional wheel running on diaphragm and cardiac function is largely unknown. Our purpose was to determine the extent to which long-term endurance exercise affected dystrophic limb, diaphragm, and cardiac function. Diaphragm specific tension was reduced by 60% (P < 0.05) in mice that performed 1 yr of volitional wheel running compared with sedentary mdx mice. Dorsiflexor mass (extensor digitorum longus and tibialis anterior) and function (extensor digitorum longus) were not altered by endurance training. In mice that performed 1 yr of volitional wheel running, plantarflexor mass (soleus and gastrocnemius) was increased and soleus tetanic force was increased 36%, while specific tension was similar in wheel-running and sedentary groups. Cardiac mass was increased 15%, left ventricle chamber size was increased 20% (diastole) and 18% (systole), and stroke volume was increased twofold in wheel-running compared with sedentary mdx mice. These data suggest that the dystrophic heart may undergo positive exercise-induced remodeling and that limb muscle function is largely unaffected. Most importantly, however, as the diaphragm most closely recapitulates the human disease, these data raise the possibility of exercise-mediated injury in dystrophic skeletal muscle.
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Affiliation(s)
- Joshua T Selsby
- Department of Animal Science, College of Agriculture and Life Sciences, Iowa State University, Ames, Iowa
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Hourdé C, Joanne P, Medja F, Mougenot N, Jacquet A, Mouisel E, Pannerec A, Hatem S, Butler-Browne G, Agbulut O, Ferry A. Voluntary physical activity protects from susceptibility to skeletal muscle contraction-induced injury but worsens heart function in mdx mice. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:1509-18. [PMID: 23465861 DOI: 10.1016/j.ajpath.2013.01.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 12/19/2012] [Accepted: 01/14/2013] [Indexed: 12/25/2022]
Abstract
It is well known that inactivity/activity influences skeletal muscle physiological characteristics. However, the effects of inactivity/activity on muscle weakness and increased susceptibility to muscle contraction-induced injury have not been extensively studied in mdx mice, a murine model of Duchenne muscular dystrophy with dystrophin deficiency. In the present study, we demonstrate that inactivity (ie, leg immobilization) worsened the muscle weakness and the susceptibility to contraction-induced injury in mdx mice. Inactivity also mimicked these two dystrophic features in wild-type mice. In contrast, we demonstrate that these parameters can be improved by activity (ie, voluntary wheel running) in mdx mice. Biochemical analyses indicate that the changes induced by inactivity/activity were not related to fiber-type transition but were associated with altered expression of different genes involved in fiber growth (GDF8), structure (Actg1), and calcium homeostasis (Stim1 and Jph1). However, activity reduced left ventricular function (ie, ejection and shortening fractions) in mdx, but not C57, mice. Altogether, our study suggests that muscle weakness and susceptibility to contraction-induced injury in dystrophic muscle could be attributable, at least in part, to inactivity. It also suggests that activity exerts a beneficial effect on dystrophic skeletal muscle but not on the heart.
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Affiliation(s)
- Christophe Hourdé
- Institute of Myology, INSERM U974, CNRS UMR7215, UPMC UM76, Université Pierre et Marie Curie-Paris 6, Sorbonne Universities, Paris, France
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Brereton D, Plochocki J, An D, Costas J, Simons E. The effects of glucocorticoid and voluntary exercise treatment on the development of thoracolumbar kyphosis in dystrophin-deficient mice. PLOS CURRENTS 2012; 4:e4ffdff160de8b. [PMID: 23145353 PMCID: PMC3493061 DOI: 10.1371/4ffdff160de8b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The development of spinal curvature deformities is a hallmark of muscular dystrophy. While glucocorticoid treatment has been shown to prolong muscle function in dystrophic mice, its effects on the development of dystrophinopathic spinal deformation are poorly understood. In this study, we test the effects of glucocorticoid treatment on the onset of thoracolumbar kyphosis in the dystrophin-deficient mdx mouse using voluntary running exercise to exacerbate muscle fibrosis. We measure the kyphotic index, erector spinae muscle fibrosis, and vertebral bone histomorphometry in 4-month-old mdx mice in four groups: sedentary control, exercise-treated (continuous voluntary access to an activity wheel), glucocorticoid-treated, and glucocorticoid + exercise-treated. Exercise treated mice were found to have significantly lower kyphotic index (i.e., greater kyphosis) and greater muscle fibrosis relative to controls (p < 0.05). However, the deleterious effect of exercise on KI and muscle fibrosis was prevented by glucocorticoid treatment. Some differences in bone histological parameters were observed between treatment groups, suggesting there is a complex relationship between dystrophic muscular changes and vertebral bone mass. Our findings indicate glucocorticoid treatment delays the onset of thoracodorsal spinal deformation in mdx mice.
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Affiliation(s)
- Daniel Brereton
- Arizona College of Osteopathic Medicine, Midwestern University
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Betts C, Saleh AF, Arzumanov AA, Hammond SM, Godfrey C, Coursindel T, Gait MJ, Wood MJ. Pip6-PMO, A New Generation of Peptide-oligonucleotide Conjugates With Improved Cardiac Exon Skipping Activity for DMD Treatment. MOLECULAR THERAPY. NUCLEIC ACIDS 2012; 1:e38. [PMID: 23344180 PMCID: PMC3438601 DOI: 10.1038/mtna.2012.30] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Antisense oligonucleotides (AOs) are currently the most promising therapeutic intervention for Duchenne muscular dystrophy (DMD). AOs modulate dystrophin pre-mRNA splicing, thereby specifically restoring the dystrophin reading frame and generating a truncated but semifunctional dystrophin protein. Challenges in the development of this approach are the relatively poor systemic AO delivery and inefficient dystrophin correction in affected non-skeletal muscle tissues, including the heart. We have previously reported impressive heart activity including high-splicing efficiency and dystrophin restoration following a single administration of an arginine-rich cell-penetrating peptide (CPPs) conjugated to a phosphorodiamidate morpholino oligonucleotide (PMO): Pip5e-PMO. However, the mechanisms underlying this activity are poorly understood. Here, we report studies involving single dose administration (12.5 mg/kg) of derivatives of Pip5e-PMO, consecutively assigned as Pip6-PMOs. These peptide-PMOs comprise alterations to the central hydrophobic core of the Pip5e peptide and illustrate that certain changes to the peptide sequence improves its activity; however, partial deletions within the hydrophobic core abolish its efficiency. Our data indicate that the hydrophobic core of the Pip sequences is critical for PMO delivery to the heart and that specific modifications to this region can enhance activity further. The results have implications for therapeutic PMO development for DMD.
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Affiliation(s)
- Corinne Betts
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Malerba A, Boldrin L, Dickson G. Long-term systemic administration of unconjugated morpholino oligomers for therapeutic expression of dystrophin by exon skipping in skeletal muscle: implications for cardiac muscle integrity. Nucleic Acid Ther 2011; 21:293-8. [PMID: 21851223 DOI: 10.1089/nat.2011.0306] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal X-linked inherited disease caused by mutations in the dystrophin gene and consequent lack of dystrophin in the skeletal, cardiac, and smooth musculature and in the nervous system. Patients die during their mid-twenties because of severe muscle loss and life-threatening respiratory and cardiac complications. The splicing modulation approach mediated by antisense oligonucleotides can restore the production of a partially functional quasi-dystrophin in skeletal muscles. We recently showed that a chronic, 12-month treatment with phosphorodiamidate morpholino oligomers efficiently restored dystrophin in widespread skeletal muscles and led to normal locomotor activity indistinguishable from that of dystrophin-expressing C57 mice. However, no detectable dystrophin expression was observed in the hearts of treated mice. In the present study, histological analyses show a more severe cardiac pathology compared with untreated animals in the face of enhanced locomotor behavior. This observation implies that the increase in locomotor activity of treated mdx mice may have a paradoxical detrimental effect on the dystrophic heart. In the context of skeletal muscle-centric therapies for DMD, our data suggest that particular vigilance should be instigated to monitor emergence of accelerated cardiac dysfunction.
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Affiliation(s)
- Alberto Malerba
- School of Biological Sciences, Royal Holloway, University of London , Egham, Surrey, United Kingdom
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Spurney CF. Cardiomyopathy of duchenne muscular dystrophy: Current understanding and future directions. Muscle Nerve 2011; 44:8-19. [DOI: 10.1002/mus.22097] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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