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Hart CC, Lee YI, Xie J, Gao G, Lin BL, Hammers DW, Sweeney HL. Potential limitations of microdystrophin gene therapy for Duchenne muscular dystrophy. JCI Insight 2024; 9:e165869. [PMID: 38713520 PMCID: PMC11382885 DOI: 10.1172/jci.insight.165869] [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: 09/29/2022] [Accepted: 05/01/2024] [Indexed: 05/09/2024] Open
Abstract
Clinical trials delivering high doses of adeno-associated viruses (AAVs) expressing truncated dystrophin molecules (microdystrophins) are underway for Duchenne muscular dystrophy (DMD). We examined the efficiency and efficacy of this strategy with 4 microdystrophin constructs (3 in clinical trials and a variant of the largest clinical construct), in a severe mouse model of DMD, using AAV doses comparable with those in clinical trials. We achieved high levels of microdystrophin expression in striated muscles with cardiac expression approximately 10-fold higher than that observed in skeletal muscle. Significant, albeit incomplete, correction of skeletal muscle disease was observed. Surprisingly, a lethal acceleration of cardiac disease occurred with 2 of the microdystrophins. The detrimental cardiac effect appears to be caused by variable competition (dependent on microdystrophin design and expression level) between microdystrophin and utrophin at the cardiomyocyte membrane. There may also be a contribution from an overloading of protein degradation. The significance of these observations for patients currently being treated with AAV-microdystrophin therapies is unclear since the levels of expression being achieved in the DMD hearts are unknown. However, these findings suggest that microdystrophin treatments need to avoid excessively high levels of expression in the heart and that cardiac function should be carefully monitored in these patients.
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Affiliation(s)
- Cora C Hart
- Department of Pharmacology & Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Young Il Lee
- Department of Pharmacology & Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Jun Xie
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worchester, Massachusetts, USA
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worchester, Massachusetts, USA
| | - Brian L Lin
- Department of Cell Biology, Neurobiology, and Anatomy & Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David W Hammers
- Department of Pharmacology & Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - H Lee Sweeney
- Department of Pharmacology & Therapeutics and
- Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
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2
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Elasbali AM, Al-Soud WA, Anwar S, Alhassan HH, Adnan M, Hassan MI. A review on mechanistic insights into structure and function of dystrophin protein in pathophysiology and therapeutic targeting of Duchenne muscular dystrophy. Int J Biol Macromol 2024; 264:130544. [PMID: 38428778 DOI: 10.1016/j.ijbiomac.2024.130544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/09/2024] [Accepted: 02/28/2024] [Indexed: 03/03/2024]
Abstract
Duchenne Muscular Dystrophy (DMD) is an X-linked recessive genetic disorder characterized by progressive and severe muscle weakening and degeneration. Among the various forms of muscular dystrophy, it stands out as one of the most common and impactful, predominantly affecting boys. The condition arises due to mutations in the dystrophin gene, a key player in maintaining the structure and function of muscle fibers. The manuscript explores the structural features of dystrophin protein and their pivotal roles in DMD. We present an in-depth analysis of promising therapeutic approaches targeting dystrophin and their implications for the therapeutic management of DMD. Several therapies aiming to restore dystrophin protein or address secondary pathology have obtained regulatory approval, and many others are ongoing clinical development. Notably, recent advancements in genetic approaches have demonstrated the potential to restore partially functional dystrophin forms. The review also provides a comprehensive overview of the status of clinical trials for major therapeutic genetic approaches for DMD. In addition, we have summarized the ongoing therapeutic approaches and advanced mechanisms of action for dystrophin restoration and the challenges associated with DMD therapeutics.
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Affiliation(s)
- Abdelbaset Mohamed Elasbali
- Department of Clinical Laboratory Science, College of Applied Medical Sciences-Qurayyat, Jouf University, Saudi Arabia
| | - Waleed Abu Al-Soud
- Department of Clinical Laboratory Science, College of Applied Sciences-Sakaka, Jouf University, Sakaka, Saudi Arabia; Molekylärbiologi, Klinisk Mikrobiologi och vårdhygien, Region Skåne, Sölvegatan 23B, 221 85 Lund, Sweden
| | - Saleha Anwar
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Hassan H Alhassan
- Department of Clinical Laboratory Science, College of Applied Sciences-Sakaka, Jouf University, Sakaka, Saudi Arabia
| | - Mohd Adnan
- Department of Biology, College of Science, University of Ha'il, Ha'il, Saudi Arabia
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India.
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3
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Stevens JA, Dobratz TC, Fischer KD, Palmer A, Bourdage K, Wong AJ, Chapoy-Villanueva H, Garry DJ, Liu JC, Kay MW, Kuzmiak-Glancy S, Townsend D. Mechanisms of reduced myocardial energetics of the dystrophic heart. Am J Physiol Heart Circ Physiol 2024; 326:H396-H407. [PMID: 38099842 PMCID: PMC11219055 DOI: 10.1152/ajpheart.00636.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 01/23/2024]
Abstract
Heart disease is a leading cause of death in patients with Duchenne muscular dystrophy (DMD), characterized by the progressive replacement of contractile tissue with scar tissue. Effective therapies for dystrophic cardiomyopathy will require addressing the disease before the onset of fibrosis, however, the mechanisms of the early disease are poorly understood. To understand the pathophysiology of DMD, we perform a detailed functional assessment of cardiac function of the mdx mouse, a model of DMD. These studies use a combination of functional, metabolomic, and spectroscopic approaches to fully characterize the contractile, energetic, and mitochondrial function of beating hearts. Through these innovative approaches, we demonstrate that the dystrophic heart has reduced cardiac reserve and is energetically limited. We show that this limitation does not result from poor delivery of oxygen. Using spectroscopic approaches, we provide evidence that mitochondria in the dystrophic heart have attenuated mitochondrial membrane potential and deficits in the flow of electrons in complex IV of the electron transport chain. These studies provide evidence that poor myocardial energetics precede the onset of significant cardiac fibrosis and likely results from mitochondrial dysfunction centered around complex IV and reduced membrane potential. The multimodal approach used here implicates specific molecular components in the etiology of reduced energetics. Future studies focused on these targets may provide therapies that improve the energetics of the dystrophic heart leading to improved resiliency against damage and preservation of myocardial contractile tissue.NEW & NOTEWORTHY Dystrophic hearts have poor contractile reserve that is associated with a reduction in myocardial energetics. We demonstrate that oxygen delivery does not contribute to the limited energy production of the dystrophic heart even with increased workloads. Cytochrome optical spectroscopy of the contracting heart reveals alterations in complex IV and evidence of depolarized mitochondrial membranes. We show specific alterations in the electron transport chain of the dystrophic heart that may contribute to poor myocardial energetics.
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Affiliation(s)
- Jackie A Stevens
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Tyler C Dobratz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kaleb D Fischer
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Alexandria Palmer
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kira Bourdage
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Anne J Wong
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Hector Chapoy-Villanueva
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Institute for Obesity Research Tecnologico de Monterrey, Monterrey, Mexico
| | - Daniel J Garry
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Lillehei Heart Institute, Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States
- Paul and Sheila Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, United States
| | - Julia C Liu
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
| | - Matthew W Kay
- Department of Biomedical Engineering, School of Engineering and Applied Science, George Washington University, Washington, District of Columbia, United States
| | - Sarah Kuzmiak-Glancy
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland, United States
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States
- Lillehei Heart Institute, Cardiovascular Division, University of Minnesota, Minneapolis, Minnesota, United States
- Paul and Sheila Muscular Dystrophy Center, University of Minnesota, Minneapolis, Minnesota, United States
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4
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Bez Batti Angulski A, Hosny N, Cohen H, Martin AA, Hahn D, Bauer J, Metzger JM. Duchenne muscular dystrophy: disease mechanism and therapeutic strategies. Front Physiol 2023; 14:1183101. [PMID: 37435300 PMCID: PMC10330733 DOI: 10.3389/fphys.2023.1183101] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/24/2023] [Indexed: 07/13/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe, progressive, and ultimately fatal disease of skeletal muscle wasting, respiratory insufficiency, and cardiomyopathy. The identification of the dystrophin gene as central to DMD pathogenesis has led to the understanding of the muscle membrane and the proteins involved in membrane stability as the focal point of the disease. The lessons learned from decades of research in human genetics, biochemistry, and physiology have culminated in establishing the myriad functionalities of dystrophin in striated muscle biology. Here, we review the pathophysiological basis of DMD and discuss recent progress toward the development of therapeutic strategies for DMD that are currently close to or are in human clinical trials. The first section of the review focuses on DMD and the mechanisms contributing to membrane instability, inflammation, and fibrosis. The second section discusses therapeutic strategies currently used to treat DMD. This includes a focus on outlining the strengths and limitations of approaches directed at correcting the genetic defect through dystrophin gene replacement, modification, repair, and/or a range of dystrophin-independent approaches. The final section highlights the different therapeutic strategies for DMD currently in clinical trials.
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Affiliation(s)
| | | | | | | | | | | | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
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5
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Hart CC, Lee YI, Hammers DW, Sweeney HL. Evaluation of the DBA/2J mouse as a potential background strain for genetic models of cardiomyopathy. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY PLUS 2022; 1:100012. [PMID: 37206988 PMCID: PMC10195103 DOI: 10.1016/j.jmccpl.2022.100012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The potential use of the D2.mdx mouse (the mdx mutation on the DBA/2J genetic background) as a preclinical model of the cardiac aspects of Duchenne muscular dystrophy (DMD) has been criticized based on speculation that the DBA/2J genetic background displays an inherent hypertrophic cardiomyopathy (HCM) phenotype. Accordingly, the goal of the current study was to further examine the cardiac status of this mouse strain over a 12-month period to determine if observable signs of HCM develop, including histopathology and pathological enlargement of the myocardium. Previous reports have documented heightened TGFβ signaling in the DBA2/J striated muscles, as compared to the C57 background, which, as expected, is manifested as increased cardiomyocyte size, wall thickness, and heart mass as compared to the C57 background. While normalized heart mass is larger in the DBA/2J mice, compared to age-matched C57/BL10 mice, both strains similarly increase in size from 4 to 12 months of age. We also report that DBA/2J mice contain equivalent amounts of left ventricular collagen as healthy canine and human samples. In a longitudinal echocardiography study, neither sedentary nor exercised DBA/2J mice demonstrated left ventricular wall thickening or cardiac functional deficits. In summary, we find no evidence of HCM, nor any other cardiac pathology, and thus propose that it is an appropriate background strain for genetic modeling of cardiac diseases, including the cardiomyopathy associated with DMD.
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Affiliation(s)
| | | | | | - H. Lee Sweeney
- Corresponding author at: 1200 Newell, Dr. ARB R5-216, Gainesville, FL 32610-0267, United States of America. (H.L. Sweeney)
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Gartz M, Haberman M, Prom MJ, Beatka MJ, Strande JL, Lawlor MW. A Long-Term Study Evaluating the Effects of Nicorandil Treatment on Duchenne Muscular Dystrophy-Associated Cardiomyopathy in mdx Mice. J Cardiovasc Pharmacol Ther 2022; 27:10742484221088655. [PMID: 35353647 DOI: 10.1177/10742484221088655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is a neuromuscular disease caused by dystrophin gene mutations affecting striated muscle. Due to advances in skeletal muscle treatment, cardiomyopathy has emerged as a leading cause of death. Previously, nicorandil, a drug with antioxidant and nitrate-like properties, ameliorated cardiac damage and improved cardiac function in young, injured mdx mice. Nicorandil mitigated damage by stimulating antioxidant activity and limiting pro-oxidant expression. Here, we examined whether nicorandil was similarly cardioprotective in aged mdx mice. METHODS AND RESULTS Nicorandil (6 mg/kg) was given over 15 months. Echocardiography of mdx mice showed some functional defects at 12 months compared to wild-type (WT) mice, but not at 15 months. Disease manifestation was evident in mdx mice via treadmill assays and survival, but not open field and grip strength assays. Cardiac levels of SOD2 and NOX4 were decreased in mdx vs. WT. Nicorandil increased survival in mdx but did not alter cardiac function, fibrosis, diaphragm function or muscle fatigue. CONCLUSIONS In contrast to our prior work in young, injured mdx mice, nicorandil did not exert cardioprotective effects in 15 month aged mdx mice. Discordant findings may be explained by the lack of cardiac disease manifestation in aged mdx mice compared to WT, whereas significant cardiac dysfunction was previously seen with the sub-acute injury in young mice. Therefore, we are not able to conclude any cardioprotective effects with long-term nicorandil treatment in aging mdx mice.
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Affiliation(s)
- Melanie Gartz
- Department of Cell Biology, Neurobiology and Anatomy, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Cardiovascular Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Neuroscience Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology and Laboratory Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margaret Haberman
- Cardiovascular Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Neuroscience Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology and Laboratory Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mariah J Prom
- Neuroscience Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology and Laboratory Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margaret J Beatka
- Neuroscience Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology and Laboratory Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jennifer L Strande
- Cardiovascular Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
| | - Michael W Lawlor
- Neuroscience Research Center, 5506Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Pathology and Laboratory Medicine, 5506Medical College of Wisconsin, Milwaukee, WI, USA
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Wang H, Marrosu E, Brayson D, Wasala NB, Johnson EK, Scott CS, Yue Y, Hau KL, Trask AJ, Froehner SC, Adams ME, Zhang L, Duan D, Montanaro F. Proteomic analysis identifies key differences in the cardiac interactomes of dystrophin and micro-dystrophin. Hum Mol Genet 2021; 30:1321-1336. [PMID: 33949649 PMCID: PMC8255133 DOI: 10.1093/hmg/ddab133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 01/16/2023] Open
Abstract
ΔR4-R23/ΔCT micro-dystrophin (μDys) is a miniaturized version of dystrophin currently evaluated in a Duchenne muscular dystrophy (DMD) gene therapy trial to treat skeletal and cardiac muscle disease. In pre-clinical studies, μDys efficiently rescues cardiac histopathology, but only partially normalizes cardiac function. To gain insights into factors that may impact the cardiac therapeutic efficacy of μDys, we compared by mass spectrometry the composition of purified dystrophin and μDys protein complexes in the mouse heart. We report that compared to dystrophin, μDys has altered associations with α1- and β2-syntrophins, as well as cavins, a group of caveolae-associated signaling proteins. In particular, we found that membrane localization of cavin-1 and cavin-4 in cardiomyocytes requires dystrophin and is profoundly disrupted in the heart of mdx5cv mice, a model of DMD. Following cardiac stress/damage, membrane-associated cavin-4 recruits the signaling molecule ERK to caveolae, which activates key cardio-protective responses. Evaluation of ERK signaling revealed a profound inhibition, below physiological baseline, in the mdx5cv mouse heart. Expression of μDys in mdx5cv mice prevented the development of cardiac histopathology but did not rescue membrane localization of cavins nor did it normalize ERK signaling. Our study provides the first comparative analysis of purified protein complexes assembled in vivo by full-length dystrophin and a therapeutic micro-dystrophin construct. This has revealed disruptions in cavins and ERK signaling that may contribute to DMD cardiomyopathy. This new knowledge is important for ongoing efforts to prevent and treat heart disease in DMD patients.
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Affiliation(s)
- Hong Wang
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus OH 43205, USA.,Department of Pediatric Cardiology, China Medical University, Liaoning 110004, China
| | - Elena Marrosu
- Developmental Neuroscience Research and Teaching Department, Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Daniel Brayson
- Developmental Neuroscience Research and Teaching Department, Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Nalinda B Wasala
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Eric K Johnson
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus OH 43205, USA
| | - Charlotte S Scott
- Developmental Neuroscience Research and Teaching Department, Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Kwan-Leong Hau
- Developmental Neuroscience Research and Teaching Department, Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
| | - Aaron J Trask
- Center for Cardiovascular Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43205, USA
| | - Stan C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Liwen Zhang
- Mass Spectrometry and Proteomics Facility, Campus Chemical Instrument Center, The Ohio State University, Columbus, OH 43210, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA.,Department of Neurology, School of Medicine, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.,Department of Bioengineering, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.,Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.,Department of Biomedical, Biological and Chemical Engineering, College of Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Federica Montanaro
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus OH 43205, USA.,Developmental Neuroscience Research and Teaching Department, Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 1EH, UK
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Improved Bone Quality and Bone Healing of Dystrophic Mice by Parabiosis. Metabolites 2021; 11:metabo11040247. [PMID: 33923553 PMCID: PMC8073674 DOI: 10.3390/metabo11040247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/27/2021] [Accepted: 04/14/2021] [Indexed: 11/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a degenerative muscle disorder characterized by a lack of dystrophin expression in the sarcolemma of muscle fibers. DMD patients acquire bone abnormalities including osteopenia, fragility fractures, and scoliosis indicating a deficiency in skeletal homeostasis. The dKO (dystrophin/Utrophin double knockout) is a more severe mouse model of DMD than the mdx mouse (dystrophin deficient), and display numerous clinically-relevant manifestations, including a spectrum of degenerative changes outside skeletal muscle including bone, articular cartilage, and intervertebral discs. To examine the influence of systemic factors on the bone abnormalities and healing in DMD, parabiotic pairing between dKO mice and mdx mice was established. Notably, heterochronic parabiosis with young mdx mice significantly increased bone mass and improved bone micro-structure in old dKO-hetero mice, which showed progressive bone deterioration. Furthermore, heterochronic parabiosis with WT C56/10J mice significantly improved tibia bone defect healing in dKO-homo mice. These results suggest that systemic blood-borne factor(s) and/or progenitors from WT and young mdx mice can influence the bone deficiencies in dKO mice. Understanding these circulating factors or progenitor cells that are responsible to alleviate the bone abnormalities in dKO mice after heterochronic parabiosis might be useful for the management of poor bone health in DMD.
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Howard ZM, Dorn LE, Lowe J, Gertzen MD, Ciccone P, Rastogi N, Odom GL, Accornero F, Chamberlain JS, Rafael-Fortney JA. Micro-dystrophin gene therapy prevents heart failure in an improved Duchenne muscular dystrophy cardiomyopathy mouse model. JCI Insight 2021; 6:146511. [PMID: 33651713 PMCID: PMC8119181 DOI: 10.1172/jci.insight.146511] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/24/2021] [Indexed: 12/19/2022] Open
Abstract
Gene replacement for Duchenne muscular dystrophy (DMD) with micro-dystrophins has entered clinical trials, but efficacy in preventing heart failure is unknown. Although most patients with DMD die from heart failure, cardiomyopathy is undetectable until the teens, so efficacy from trials in young boys will be unknown for a decade. Available DMD animal models were sufficient to demonstrate micro-dystrophin efficacy on earlier onset skeletal muscle pathology underlying loss of ambulation and respiratory insufficiency in patients. However, no mouse models progressed into heart failure, and dog models showed highly variable progression insufficient to evaluate efficacy of micro-dystrophin or other therapies on DMD heart failure. To overcome this barrier, we have generated the first DMD mouse model to our knowledge that reproducibly progresses into heart failure. This model shows cardiac inflammation and fibrosis occur prior to reduced function. Fibrosis does not continue to accumulate, but inflammation persists after function declines. We used this model to test micro-dystrophin gene therapy efficacy on heart failure prevention for the first time. Micro-dystrophin prevented declines in cardiac function and prohibited onset of inflammation and fibrosis. This model will allow identification of committed pathogenic steps to heart failure and testing of genetic and nongenetic therapies to optimize cardiac care for patients with DMD.
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Affiliation(s)
- Zachary M. Howard
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Lisa E. Dorn
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Jeovanna Lowe
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Megan D. Gertzen
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Pierce Ciccone
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Neha Rastogi
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Guy L. Odom
- Department of Neurology and Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington, USA
| | - Federica Accornero
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Jeffrey S. Chamberlain
- Department of Neurology and Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington, USA
| | - Jill A. Rafael-Fortney
- Department of Physiology & Cell Biology and Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA
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10
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Carraro U, Yablonka-Reuveni Z. Translational research on Myology and Mobility Medicine: 2021 semi-virtual PDM3 from Thermae of Euganean Hills, May 26 - 29, 2021. Eur J Transl Myol 2021; 31:9743. [PMID: 33733717 PMCID: PMC8056169 DOI: 10.4081/ejtm.2021.9743] [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: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 02/08/2023] Open
Abstract
On 19-21 November 2020, the meeting of the 30 years of the Padova Muscle Days was virtually held while the SARS-CoV-2 epidemic was hitting the world after a seemingly quiet summer. During the 2020-2021 winter, the epidemic is still active, despite the start of vaccinations. The organizers hope to hold the 2021 Padua Days on Myology and Mobility Medicine in a semi-virtual form (2021 S-V PDM3) from May 26 to May 29 at the Thermae of Euganean Hills, Padova, Italy. Here the program and the Collection of Abstracts are presented. Despite numerous world problems, the number of submitted/selected presentations (lectures and oral presentations) has increased, prompting the organizers to extend the program to four dense days.
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Affiliation(s)
- Ugo Carraro
- Department of Biomedical Sciences of the University of Padova, Italy; CIR-Myo - Myology Centre, University of Padova, Italy; A-C Mioni-Carraro Foundation for Translational Myology, Padova.
| | - Zipora Yablonka-Reuveni
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA.
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11
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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: 9] [Impact Index Per Article: 3.0] [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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12
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Packer D, Martin PT. Micro-laminin gene therapy can function as an inhibitor of muscle disease in the dy W mouse model of MDC1A. Mol Ther Methods Clin Dev 2021; 21:274-287. [PMID: 33869655 PMCID: PMC8026908 DOI: 10.1016/j.omtm.2021.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 02/03/2021] [Indexed: 02/04/2023]
Abstract
Gene replacement for laminin-α2-deficient congenital muscular dystrophy 1A (MDC1A) is currently not possible using a single adeno-associated virus (AAV) vector due to the large size of the LAMA2 gene. LAMA2 encodes laminin-α2, a subunit of the trimeric laminin-211 extracellular matrix (ECM) protein that is the predominant laminin expressed in skeletal muscle. LAMA2 expression stabilizes skeletal muscle, in part by binding membrane receptors via its five globular (G) domains. We created a small, AAV-deliverable, micro-laminin gene therapy that expresses these G1-5 domains, LAMA2(G1-5), to test their therapeutic efficacy in the dyW mouse model for MDC1A. We also fused the heparin-binding (HB) domain from HB epidermal growth factor-like growth factor (HB-EGF) to LAMA2(G1-5) to test whether this would increase muscle ECM expression. dyW mice treated intravenously with rAAV9.CMV.HB-LAMA2(G1-5) showed increased muscle ECM expression of transgenic protein relative to mice treated with rAAV9.CMV.LAMA2(G1-5) and showed improved weight-normalized forelimb grip strength relative to untreated dyW mice. Additionally, dyW muscle fibers expressing either micro-laminin protein showed some measures of reduced pathology, although levels of muscle cell apoptosis and inflammation were not decreased. Although systemic expression of rAAV9.CMV.HB-LAMA2(G1-5) did not inhibit all disease phenotypes, these studies demonstrate the feasibility of using a micro-laminin gene therapy strategy to deliver gene replacement for MDC1A.
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Affiliation(s)
- Davin Packer
- Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
- Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, USA
| | - Paul T. Martin
- Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
- Corresponding author Paul T. Martin, Center for Gene Therapy, Abigail Wexner Research Institute, The Research Institute at Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43209, USA.
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13
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Meyers TA, Heitzman JA, Townsend D. DMD carrier model with mosaic dystrophin expression in the heart reveals complex vulnerability to myocardial injury. Hum Mol Genet 2020; 29:944-954. [PMID: 31976522 PMCID: PMC7158376 DOI: 10.1093/hmg/ddaa015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/26/2019] [Accepted: 01/20/2020] [Indexed: 12/13/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a devastating neuromuscular disease that causes progressive muscle wasting and cardiomyopathy. This X-linked disease results from mutations of the DMD allele on the X-chromosome resulting in the loss of expression of the protein dystrophin. Dystrophin loss causes cellular dysfunction that drives the loss of healthy skeletal muscle and cardiomyocytes. As gene therapy strategies strive toward dystrophin restoration through micro-dystrophin delivery or exon skipping, preclinical models have shown that incomplete restoration in the heart results in heterogeneous dystrophin expression throughout the myocardium. This outcome prompts the question of how much dystrophin restoration is sufficient to rescue the heart from DMD-related pathology. Female DMD carrier hearts can shed light on this question, due to their mosaic cardiac dystrophin expression resulting from random X-inactivation. In this work, a dystrophinopathy carrier mouse model was derived by breeding male or female dystrophin-null mdx mice with a wild type mate. We report that these carrier hearts are significantly susceptible to injury induced by one or multiple high doses of isoproterenol, despite expressing ~57% dystrophin. Importantly, only carrier mice with dystrophic mothers showed mortality after isoproterenol. These findings indicate that dystrophin restoration in approximately half of the heart still allows for marked vulnerability to injury. Additionally, the discovery of divergent stress-induced mortality based on parental origin in mice with equivalent dystrophin expression underscores the need for better understanding of the epigenetic, developmental, and even environmental factors that may modulate vulnerability in the dystrophic heart.
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Affiliation(s)
- Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Jackie A Heitzman
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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14
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Razzoli M, Lindsay A, Law ML, Chamberlain CM, Southern WM, Berg M, Osborn J, Engeland WC, Metzger JM, Ervasti JM, Bartolomucci A. Social stress is lethal in the mdx model of Duchenne muscular dystrophy. EBioMedicine 2020; 55:102700. [PMID: 32192914 PMCID: PMC7251247 DOI: 10.1016/j.ebiom.2020.102700] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/10/2020] [Accepted: 02/18/2020] [Indexed: 12/19/2022] Open
Abstract
Background Duchenne muscular dystrophy (DMD) is caused by the loss of dystrophin. Severe and ultimately lethal, DMD progresses relatively slowly in that patients become wheelchair bound only around age twelve with a survival expectancy reaching the third decade of life. Methods The mildly-affected mdx mouse model of DMD, and transgenic DysΔMTB-mdx and Fiona-mdx mice expressing dystrophin or utrophin, respectively, were exposed to either mild (scruffing) or severe (subordination stress) stress paradigms and profiled for their behavioral and physiological responses. A subgroup of mdx mice exposed to subordination stress were pretreated with the beta-blocker metoprolol. Findings Subordination stress caused lethality in ∼30% of mdx mice within 24 h and ∼70% lethality within 48 h, which was not rescued by metoprolol. Lethality was associated with heart damage, waddling gait and hypo-locomotion, as well as marked up-regulation of the hypothalamus-pituitary-adrenocortical axis. A novel cardiovascular phenotype emerged in mdx mice, in that scruffing caused a transient drop in arterial pressure, while subordination stress caused severe and sustained hypotension with concurrent tachycardia. Transgenic expression of dystrophin or utrophin in skeletal muscle protected mdx mice from scruffing and social stress-induced responses including mortality. Interpretation We have identified a robust new stress phenotype in the otherwise mildly affected mdx mouse that suggests relatively benign handling may impact the outcome of behavioural experiments, but which should also expedite the knowledge-based therapy development for DMD. Funding Greg Marzolf Jr. Foundation, Summer's Wish Fund, NIAMS, Muscular Dystrophy Association, University of Minnesota and John and Cheri Gunvalson Trust.
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Affiliation(s)
- Maria Razzoli
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Angus Lindsay
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Michelle L Law
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Christopher M Chamberlain
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, United States
| | - William M Southern
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Madeleine Berg
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - John Osborn
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - William C Engeland
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, United States.
| | - Alessandro Bartolomucci
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, United States.
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15
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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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16
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Fischer KD, Heitzman JA, Townsend D. Hyperbaric therapy provides no benefit for skeletal muscle and respiratory function and accelerates cardiac injury in mdx mice. Sci Rep 2019; 9:12306. [PMID: 31444390 PMCID: PMC6707265 DOI: 10.1038/s41598-019-48744-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 08/07/2019] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a uniformly fatal condition of striated muscle wasting resulting in premature death from respiratory and/or cardiac failure. Symptomatic therapy has prolonged survival by limiting deaths resulting from respiratory insufficiency, but there is currently no effective therapy for most patients with DMD. This grim prognosis has led patients and their families to seek unproven therapeutic approaches. One such approach is the use of hyperbaric therapies, which 14% of DMD patients self-report using. The primary goal of this study was to determine if intermittent hyperbaric exposure altered the muscle function of the mdx mouse, a genetic model of DMD. To do this, mdx mice were exposed to three daily 90-minute 1.3 atmosphere hyperbaric exposures for 4 weeks. Skeletal muscle, respiratory, and cardiac function were assessed in treated and untreated wild type and dystrophic mice. The results of these studies find that hyperbaric and hyperoxic approaches resulted in increased cardiac fibrosis in dystrophic mice and no beneficial effects on the functional parameters measured. These data suggest that these oxygen-based therapies are unlikely to provide therapeutic benefit to DMD patients.
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Affiliation(s)
- Kaleb D Fischer
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Jackie A Heitzman
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA.
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17
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Meyers TA, Townsend D. Cardiac Pathophysiology and the Future of Cardiac Therapies in Duchenne Muscular Dystrophy. Int J Mol Sci 2019; 20:E4098. [PMID: 31443395 PMCID: PMC6747383 DOI: 10.3390/ijms20174098] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 12/25/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a devastating disease featuring skeletal muscle wasting, respiratory insufficiency, and cardiomyopathy. Historically, respiratory failure has been the leading cause of mortality in DMD, but recent improvements in symptomatic respiratory management have extended the life expectancy of DMD patients. With increased longevity, the clinical relevance of heart disease in DMD is growing, as virtually all DMD patients over 18 year of age display signs of cardiomyopathy. This review will focus on the pathophysiological basis of DMD in the heart and discuss the therapeutic approaches currently in use and those in development to treat dystrophic cardiomyopathy. The first section will describe the aspects of the DMD that result in the loss of cardiac tissue and accumulation of fibrosis. The second section will discuss cardiac small molecule therapies currently used to treat heart disease in DMD, with a focus on the evidence supporting the use of each drug in dystrophic patients. The final section will outline the strengths and limitations of approaches directed at correcting the genetic defect through dystrophin gene replacement, modification, or repair. There are several new and promising therapeutic approaches that may protect the dystrophic heart, but their limitations suggest that future management of dystrophic cardiomyopathy may benefit from combining gene-targeted therapies with small molecule therapies. Understanding the mechanistic basis of dystrophic heart disease and the effects of current and emerging therapies will be critical for their success in the treatment of patients with DMD.
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Affiliation(s)
- Tatyana A Meyers
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN 55455, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN 55455, USA.
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18
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Parvatiyar MS, Brownstein AJ, Kanashiro-Takeuchi RM, Collado JR, Dieseldorff Jones KM, Gopal J, Hammond KG, Marshall JL, Ferrel A, Beedle AM, Chamberlain JS, Renato Pinto J, Crosbie RH. Stabilization of the cardiac sarcolemma by sarcospan rescues DMD-associated cardiomyopathy. JCI Insight 2019; 5:123855. [PMID: 31039133 PMCID: PMC6629091 DOI: 10.1172/jci.insight.123855] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 04/23/2019] [Indexed: 02/02/2023] Open
Abstract
In the current preclinical study, we demonstrate the therapeutic potential of sarcospan (SSPN) overexpression to alleviate cardiomyopathy associated with Duchenne muscular dystrophy (DMD) utilizing dystrophin-deficient mdx mice with utrophin haploinsufficiency that more accurately represent the severe disease course of human DMD. SSPN interacts with dystrophin, the DMD disease gene product, and its autosomal paralog utrophin, which is upregulated in DMD as a partial compensatory mechanism. SSPN transgenic mice have enhanced abundance of fully glycosylated α-dystroglycan, which may further protect dystrophin-deficient cardiac membranes. Baseline echocardiography reveals SSPN improves systolic function and hypertrophic indices in mdx and mdx:utr-heterozygous mice. Assessment of SSPN transgenic mdx mice by hemodynamic pressure-volume methods highlights enhanced systolic performance compared to mdx controls. SSPN restores cardiac sarcolemma stability, the primary defect in DMD disease, reduces fibrotic response and improves contractile function. We demonstrate that SSPN ameliorates more advanced cardiac disease in the context of diminished sarcolemma expression of utrophin and β1D integrin that mitigate disease severity and partially restores responsiveness to β-adrenergic stimulation. Overall, our current and previous findings suggest SSPN overexpression in DMD mouse models positively impacts skeletal, pulmonary and cardiac performance by addressing the stability of proteins at the sarcolemma that protect the heart from injury, supporting SSPN and membrane stabilization as a therapeutic target for DMD.
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Affiliation(s)
- Michelle S. Parvatiyar
- Department of Integrative Biology & Physiology and
- Center for Duchenne Muscular Dystrophy, UCLA, Los Angeles, California, USA
| | - Alexandra J. Brownstein
- Department of Integrative Biology & Physiology and
- Center for Duchenne Muscular Dystrophy, UCLA, Los Angeles, California, USA
| | - Rosemeire M. Kanashiro-Takeuchi
- Interdisciplinary Stem Cell Institute, University of Miami, Florida, USA
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | | | | | - Jay Gopal
- Department of Integrative Biology & Physiology and
| | - Katherine G. Hammond
- Department of Integrative Biology & Physiology and
- Center for Duchenne Muscular Dystrophy, UCLA, Los Angeles, California, USA
| | - Jamie L. Marshall
- Department of Integrative Biology & Physiology and
- Center for Duchenne Muscular Dystrophy, UCLA, Los Angeles, California, USA
| | - Abel Ferrel
- Department of Integrative Biology & Physiology and
| | - Aaron M. Beedle
- Department of Pharmaceutical Sciences, Binghamton University State University of New York, Binghamton, New York, USA
| | | | - Jose Renato Pinto
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA
| | - Rachelle H. Crosbie
- Department of Integrative Biology & Physiology and
- Center for Duchenne Muscular Dystrophy, UCLA, Los Angeles, California, USA
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
- Molecular Biology Institute, UCLA, Los Angeles, California, USA
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19
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Xu R, Jia Y, Zygmunt DA, Martin PT. rAAVrh74.MCK.GALGT2 Protects against Loss of Hemodynamic Function in the Aging mdx Mouse Heart. Mol Ther 2019; 27:636-649. [PMID: 30711447 PMCID: PMC6403484 DOI: 10.1016/j.ymthe.2019.01.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/31/2018] [Accepted: 01/07/2019] [Indexed: 01/16/2023] Open
Abstract
Dilated cardiomyopathy is a common cause of death in patients with Duchenne muscular dystrophy (DMD). Gene therapies for DMD must, therefore, have a therapeutic impact in cardiac as well as skeletal muscles. Our previous studies have shown that GALGT2 overexpression in mdx skeletal muscles can prevent muscle damage. Here we have tested whether rAAVrh74.MCK.GALGT2 gene therapy in mdx cardiac muscle can prevent the loss of heart function. Treatment of mdx hearts with rAAVrh74.MCK.GALGT2 1 day after birth did not negatively alter hemodynamic function, tested at 3 months of age, and it prevented early left ventricular remodeling and expression of fibrotic gene markers. Intravenous treatment of mdx mice with rAAVrh74.MCK.GALGT2 at 2 months of age significantly improved stroke volume and cardiac output compared to mock-treated mice analyzed at 17 months, both at rest and after stimulation with dobutamine. rAAVrh74.MCK.GALGT2 treatment of mdx heart correlated with increased glycosylation of α-dystroglycan with the CT glycan and increased utrophin protein expression. These data provide the first demonstration that GALGT2 overexpression can inhibit the loss of cardiac function in the dystrophin-deficient heart and, thus, may benefit both cardiac and skeletal muscles in DMD patients.
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Affiliation(s)
- Rui Xu
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Ying Jia
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Deborah A Zygmunt
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Paul T Martin
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA; Department of Pediatrics, Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH 43210, USA.
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20
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Heier CR, Yu Q, Fiorillo AA, Tully CB, Tucker A, Mazala DA, Uaesoontrachoon K, Srinivassane S, Damsker JM, Hoffman EP, Nagaraju K, Spurney CF. Vamorolone targets dual nuclear receptors to treat inflammation and dystrophic cardiomyopathy. Life Sci Alliance 2019; 2:2/1/e201800186. [PMID: 30745312 PMCID: PMC6371196 DOI: 10.26508/lsa.201800186] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 12/25/2022] Open
Abstract
Cardiomyopathy is a leading cause of death for Duchenne muscular dystrophy. Here, we find that the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) can share common ligands but play distinct roles in dystrophic heart and skeletal muscle pathophysiology. Comparisons of their ligand structures indicate that the Δ9,11 modification of the first-in-class drug vamorolone enables it to avoid interaction with a conserved receptor residue (N770/N564), which would otherwise activate transcription factor properties of both receptors. Reporter assays show that vamorolone and eplerenone are MR antagonists, whereas prednisolone is an MR agonist. Macrophages, cardiomyocytes, and CRISPR knockout myoblasts show vamorolone is also a dissociative GR ligand that inhibits inflammation with improved safety over prednisone and GR-specific deflazacort. In mice, hyperaldosteronism activates MR-driven hypertension and kidney phenotypes. We find that genetic dystrophin loss provides a second hit for MR-mediated cardiomyopathy in Duchenne muscular dystrophy model mice, as aldosterone worsens fibrosis, mass and dysfunction phenotypes. Vamorolone successfully prevents MR-activated phenotypes, whereas prednisolone activates negative MR and GR effects. In conclusion, vamorolone targets dual nuclear receptors to treat inflammation and cardiomyopathy with improved safety.
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Affiliation(s)
- Christopher R Heier
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA .,Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - Qing Yu
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - Alyson A Fiorillo
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.,Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - Christopher B Tully
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - Asya Tucker
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - Davi A Mazala
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | | | | | | | - Eric P Hoffman
- AGADA Biosciences Incorporated, Halifax, Nova Scotia, Canada.,ReveraGen BioPharma, Incorporated, Rockville, MD, USA.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University-State University of New York (SUNY), Binghamton, NY, USA
| | - Kanneboyina Nagaraju
- AGADA Biosciences Incorporated, Halifax, Nova Scotia, Canada.,ReveraGen BioPharma, Incorporated, Rockville, MD, USA.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University-State University of New York (SUNY), Binghamton, NY, USA
| | - Christopher F Spurney
- Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA.,Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA.,Division of Cardiology, Children's National Heart Institute, Children's National Medical Center, Washington, DC, USA
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21
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Ramos JN, Hollinger K, Bengtsson NE, Allen JM, Hauschka SD, Chamberlain JS. Development of Novel Micro-dystrophins with Enhanced Functionality. Mol Ther 2019; 27:623-635. [PMID: 30718090 PMCID: PMC6403485 DOI: 10.1016/j.ymthe.2019.01.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/03/2019] [Accepted: 01/07/2019] [Indexed: 01/24/2023] Open
Abstract
Gene therapies using adeno-associated viral (AAV) vectors have advanced into clinical trials for several diseases, including Duchenne muscular dystrophy (DMD). A limitation of AAV is the carrying capacity (∼5 kb) available for genes and regulatory cassettes (RCs). These size constraints are problematic for the 2.2-Mb dystrophin gene. We previously designed a variety of miniaturized micro-dystrophins (μDys) that displayed significant, albeit incomplete, function in striated muscles. To develop μDys proteins with improved performance, we explored structural modifications of the dystrophin central rod domain. Eight μDys variants were studied that carried unique combinations of between four and six of the 24 spectrin-like repeats present in the full-length protein, as well as various hinge domains. Expression of μDys was regulated by a strong but compact muscle-restricted RC (CK8e) or by the ubiquitously active cytomegalovirus (CMV) RC. Vectors were evaluated by intramuscular injection and systemic delivery to dystrophic mdx4cv mice, followed by analysis of skeletal muscle pathophysiology. Two μDys designs were identified that led to increased force generation compared with previous μDys while also localizing neuronal nitric oxide synthase to the sarcolemma. An AAV vector expressing the smaller of these (μDys5) from the CK8e RC is currently being evaluated in a DMD clinical trial.
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Affiliation(s)
- Julian N Ramos
- Molecular and Cellular Biology Program, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Katrin Hollinger
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Niclas E Bengtsson
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - James M Allen
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Stephen D Hauschka
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Jeffrey S Chamberlain
- Molecular and Cellular Biology Program, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
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22
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Meyers TA, Heitzman JA, Krebsbach AM, Aufdembrink LM, Hughes R, Bartolomucci A, Townsend D. Acute AT 1R blockade prevents isoproterenol-induced injury in mdx hearts. J Mol Cell Cardiol 2019; 128:51-61. [PMID: 30664850 DOI: 10.1016/j.yjmcc.2019.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/31/2018] [Accepted: 01/15/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is an X-linked disease characterized by skeletal muscle degeneration and a significant cardiomyopathy secondary to cardiomyocyte damage and myocardial loss. The molecular basis of DMD lies in the absence of the protein dystrophin, which plays critical roles in mechanical membrane integrity and protein localization at the sarcolemma. A popular mouse model of DMD is the mdx mouse, which lacks dystrophin and displays mild cardiac and skeletal pathology that can be exacerbated to advance the disease state. In clinical and pre-clinical studies of DMD, angiotensin signaling pathways have emerged as therapeutic targets due to their adverse influence on muscle remodeling and oxidative stress. Here we aim to establish a physiologically relevant cardiac injury model in the mdx mouse, and determine whether acute blockade of the angiotensin II type 1 receptor (AT1R) may be utilized for prevention of dystrophic injury. METHODS AND RESULTS A single IP injection of isoproterenol (Iso, 10 mg/kg) was used to induce cardiac stress and injury in mdx and wild type (C57Bl/10) mice. Mice were euthanized 8 h, 30 h, 1 week, or 1 month following the injection, and hearts were harvested for injury evaluation. At 8 and 30 h post-injury, mdx hearts showed 2.2-fold greater serum cTnI content and 3-fold more extensive injury than wild type hearts. Analysis of hearts 1 week and 1 month after injury revealed significantly higher fibrosis in mdx hearts, with a more robust and longer-lasting immune response compared to wild type hearts. In the 30-hour group, losartan treatment initiated 1 h before Iso injection protected dystrophic hearts from cardiac damage, reducing mdx acute injury area by 2.8-fold, without any significant effect on injury in wild type hearts. However, both wild type and dystrophic hearts showed a 2-fold reduction in the magnitude of the macrophage response to injury 30 h after Iso with losartan. CONCLUSIONS This work demonstrates that acute blockade of AT1R has the potential for robust injury prevention in a model of Iso-induced dystrophic heart injury. In addition to selectively limiting dystrophic cardiac damage, blocking AT1R may serve to limit the inflammatory nature of the immune response to injury in all hearts. Our findings strongly suggest that earlier adoption of angiotensin receptor blockers in DMD patients could limit myocardial damage and subsequent cardiomyopathy.
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MESH Headings
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Cardiomyopathies/drug therapy
- Cardiomyopathies/genetics
- Cardiomyopathies/pathology
- Dystrophin/genetics
- Heart/drug effects
- Heart/physiopathology
- Humans
- Isoproterenol/pharmacology
- Losartan/pharmacology
- Mice
- Mice, Inbred mdx
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/pathology
- Receptor, Angiotensin, Type 1/genetics
- Sarcolemma/metabolism
- Sarcolemma/pathology
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Affiliation(s)
- Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Jackie A Heitzman
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Aimee M Krebsbach
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA; Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Lauren M Aufdembrink
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Robert Hughes
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Alessandro Bartolomucci
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, USA; Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN, USA.
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23
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Shao W, Chen X, Samulski RJ, Hirsch ML, Li C. Inhibition of antigen presentation during AAV gene therapy using virus peptides. Hum Mol Genet 2019; 27:601-613. [PMID: 29272432 DOI: 10.1093/hmg/ddx427] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 12/12/2017] [Indexed: 11/14/2022] Open
Abstract
The clinical trial using adeno-associated virus (AAV) vector delivery of mini-dystrophin in patients with Duchenne Muscular Dystrophy (DMD) demonstrated a cytotoxic lymphocyte (CTL) response targeting the transgene product. These mini-dystrophin-specific T-cells have the potential to clear all transduced muscle, presenting the general gene therapy concern of overcoming the CTL response to foreign proteins that provide therapeutic benefit. In this study, we exploited a natural immunosuppression strategy employed by some viruses that results in CTL evasion only in transduced cells. After transfection of the plasmids encoding viral peptides and ovalbumin, which includes the immune-domain epitope SIINFEKL, several viral small peptides (ICP47 and US6) inhibited the SIINFEKL peptide presentation. A single AAV vector genome that consisted of either transgene AAT fused with SIINFEKL epitope and, separately, ICP47 expressed from different promoters or a single fusion protein with ICP47 linked by a furin cleavage peptide (AATOVA-ICP47) decreased antigen presentation. Compared with AAV/AATOVA in which decreased AAT expression was observed at late time points, persistent transgene expression was obtained after systemic administration of AAV/AATOVA-ICP47 vectors in mice. We extended this strategy to DMD gene therapy. After administration of AAV vector encoding human mini-dystrophin fusion protein with ICP47 into mdx mice, a lower mini-dystrophin-specific CTL response was induced. Importantly, the ICP47 fusion to mini-dystrophin inhibited CTLs mediated cytotoxicity. Although demonstrated herein using AAT and mini-dystrophin transgenes in an AAV context, the collective results have implications for all gene therapy applications resulting in foreign peptides by immune suppression in only genetically modified cells.
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Affiliation(s)
- Wenwei Shao
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Xiaojing Chen
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Richard J Samulski
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matthew L Hirsch
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Chengwen Li
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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24
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Lowe J, Kadakia FK, Zins JG, Haupt M, Peczkowski KK, Rastogi N, Floyd KT, Gomez-Sanchez EP, Gomez-Sanchez CE, Elnakish MT, Rafael-Fortney JA, Janssen PML. Mineralocorticoid Receptor Antagonists in Muscular Dystrophy Mice During Aging and Exercise. J Neuromuscul Dis 2018; 5:295-306. [PMID: 30010143 DOI: 10.3233/jnd-180323] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Mineralocorticoid receptor antagonists added to angiotensin converting enzyme inhibitors have shown preclinical efficacy for both skeletal and cardiac muscle outcomes in young sedentary dystrophin-deficient mdx mice also haploinsufficient for utrophin, a Duchenne muscular dystrophy (DMD) model. The mdx genotypic DMD model has mild pathology, making non-curative therapeutic effects difficult to distinguish at baseline. Since the cardiac benefit of mineralocorticoid receptor antagonists has been translated to DMD patients, it is important to optimize potential advantages for skeletal muscle by further defining efficacy parameters. OBJECTIVE We aimed to test whether therapeutic effects of mineralocorticoid receptor antagonists added to angiotensin converting enzyme inhibitors are detectable using three different reported methods of exacerbating the mdx phenotype. METHODS We tested treatment with lisinopril and the mineralocorticoid receptor antagonist spironolactone in: 10 week-old exercised, 1 year-old sedentary, and 5 month-old isoproterenol treated mdx mice and performed comprehensive functional and histological measurements. RESULTS None of the protocols to exacerbate mdx phenotypes resulted in dramatically enhanced pathology and no significant benefit was observed with treatment. CONCLUSIONS Since endogenous mineralocorticoid aldosterone production from immune cells in dystrophic muscle may explain antagonist efficacy, it is likely that these drugs work optimally during the narrow window of peak inflammation in mdx mice. Exercised and aged mdx mice do not display prolific damage and inflammation, likely explaining the absence of continued efficacy of these drugs. Since inflammation is more prevalent in DMD patients, the therapeutic window for mineralocorticoid receptor antagonists in patients may be longer.
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Affiliation(s)
- Jeovanna Lowe
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Feni K Kadakia
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Jonathan G Zins
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Michael Haupt
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Kyra K Peczkowski
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Neha Rastogi
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Kyle T Floyd
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Elise P Gomez-Sanchez
- Department of Pharmacology & Toxicology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Celso E Gomez-Sanchez
- Department of Internal Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Mohammad T Elnakish
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA.,Department of Pharmacology & Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Jill A Rafael-Fortney
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology & Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA
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25
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Kennedy TL, Guiraud S, Edwards B, Squire S, Moir L, Babbs A, Odom G, Golebiowski D, Schneider J, Chamberlain JS, Davies KE. Micro-utrophin Improves Cardiac and Skeletal Muscle Function of Severely Affected D2/ mdx Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 11:92-105. [PMID: 30417024 PMCID: PMC6216100 DOI: 10.1016/j.omtm.2018.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked muscle-wasting disease caused by mutations in the dystrophin gene. DMD boys are wheelchair-bound around 12 years and generally survive into their twenties. There is currently no effective treatment except palliative care, although personalized treatments such as exon skipping, stop codon read-through, and viral-based gene therapies are making progress. Patients present with skeletal muscle pathology, but most also show cardiomyopathy by the age of 10. A systemic therapeutic approach is needed that treats the heart and skeletal muscle defects in all patients. The dystrophin-related protein utrophin has been shown to compensate for the lack of dystrophin in the mildly affected BL10/mdx mouse. The purpose of this investigation was to demonstrate that AAV9-mediated micro-utrophin transgene delivery can not only functionally replace dystrophin in the heart, but also attenuate the skeletal muscle phenotype in severely affected D2/mdx mice. The data presented here show that utrophin can indeed alleviate the pathology in skeletal and cardiac muscle in D2/mdx mice. These results endorse the view that utrophin modulation has the potential to increase the quality life of all DMD patients whatever their mutation.
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Affiliation(s)
- Tahnee L Kennedy
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Simon Guiraud
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Ben Edwards
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Sarah Squire
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Lee Moir
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Arran Babbs
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
| | - Guy Odom
- Wellstone Muscular Dystrophy Research Centre, Department of Neurology, University of Washington, Seattle, WA, USA
| | | | | | - Jeffrey S Chamberlain
- Wellstone Muscular Dystrophy Research Centre, Department of Neurology, University of Washington, Seattle, WA, USA
| | - Kay E Davies
- Oxford Neuromuscular Centre at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford OX1 3PT, UK
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26
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Personalized gene and cell therapy for Duchenne Muscular Dystrophy. Neuromuscul Disord 2018; 28:803-824. [DOI: 10.1016/j.nmd.2018.06.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 06/19/2018] [Accepted: 06/22/2018] [Indexed: 01/09/2023]
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27
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Duan D. Systemic AAV Micro-dystrophin Gene Therapy for Duchenne Muscular Dystrophy. Mol Ther 2018; 26:2337-2356. [PMID: 30093306 PMCID: PMC6171037 DOI: 10.1016/j.ymthe.2018.07.011] [Citation(s) in RCA: 287] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/05/2018] [Accepted: 07/11/2018] [Indexed: 12/23/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal muscle disease caused by dystrophin gene mutation. Conceptually, replacing the mutated gene with a normal one would cure the disease. However, this task has encountered significant challenges due to the enormous size of the gene and the distribution of muscle throughout the body. The former creates a hurdle for viral vector packaging and the latter begs for whole-body therapy. To address these obstacles, investigators have invented the highly abbreviated micro-dystrophin gene and developed body-wide systemic gene transfer with adeno-associated virus (AAV). Numerous microgene configurations and various AAV serotypes have been explored in animal models in many laboratories. Preclinical data suggests that intravascular AAV micro-dystrophin delivery can significantly ameliorate muscle pathology, enhance muscle force, and attenuate dystrophic cardiomyopathy in animals. Against this backdrop, several clinical trials have been initiated to test the safety and tolerability of this promising therapy in DMD patients. While these trials are not powered to reach a conclusion on clinical efficacy, findings will inform the field on the prospects of body-wide DMD therapy with a synthetic micro-dystrophin AAV vector. This review discusses the history, current status, and future directions of systemic AAV micro-dystrophin therapy.
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Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA; Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Department of Neurology, School of Medicine, University of Missouri, Columbia, MO 65212, USA; Department of Bioengineering, University of Missouri, Columbia, MO 65212, USA.
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28
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Nance ME, Hakim CH, Yang NN, Duan D. Nanotherapy for Duchenne muscular dystrophy. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10. [PMID: 28398005 DOI: 10.1002/wnan.1472] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 02/09/2017] [Accepted: 03/11/2017] [Indexed: 12/14/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a lethal X-linked childhood muscle wasting disease caused by mutations in the dystrophin gene. Nanobiotechnology-based therapies (such as synthetic nanoparticles and naturally existing viral and nonviral nanoparticles) hold great promise to replace and repair the mutated dystrophin gene and significantly change the disease course. While a majority of DMD nanotherapies are still in early preclinical development, several [such as adeno-associated virus (AAV)-mediated systemic micro-dystrophin gene therapy] are advancing for phase I clinical trials. Recent regulatory approval of Ataluren (a nonsense mutation read-through chemical) in Europe and Exondys51 (an exon-skipping antisense oligonucleotide drug) in the United States shall offer critical insight in how to move DMD nanotherapy to human patients. Progress in novel, optimized nano-delivery systems may further improve emerging molecular therapeutic modalities for DMD. Despite these progresses, DMD nanotherapy faces a number of unique challenges. Specifically, the dystrophin gene is one of the largest genes in the genome while nanoparticles have an inherent size limitation per definition. Furthermore, muscle is the largest tissue in the body and accounts for 40% of the body mass. How to achieve efficient bodywide muscle targeting in human patients with nanomedication remains a significant translational hurdle. New creative approaches in the design of the miniature micro-dystrophin gene, engineering of muscle-specific synthetic AAV capsids, and novel nanoparticle-mediated exon-skipping are likely to result in major breakthroughs in DMD therapy. WIREs Nanomed Nanobiotechnol 2018, 10:e1472. doi: 10.1002/wnan.1472 This article is categorized under: Biology-Inspired Nanomaterials > Protein and Virus-Based Structures Therapeutic Approaches and Drug Discovery > Emerging Technologies.
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Affiliation(s)
- Michael E Nance
- Department of Microbiology and Immunology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Chady H Hakim
- Department of Microbiology and Immunology, University of Missouri School of Medicine, Columbia, MO, USA.,National Center for Advancing Translational Sciences, NIH, Rockville, MD, USA
| | - N Nora Yang
- National Center for Advancing Translational Sciences, NIH, Rockville, MD, USA
| | - Dongsheng Duan
- Department of Microbiology and Immunology, University of Missouri School of Medicine, Columbia, MO, USA.,Department of Neurology, University of Missouri, Columbia, MO, USA.,Department of Bioengineering, University of Missouri, Columbia, MO, USA.,Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
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29
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Johnstone VPA, Viola HM, Hool LC. Dystrophic Cardiomyopathy-Potential Role of Calcium in Pathogenesis, Treatment and Novel Therapies. Genes (Basel) 2017; 8:genes8040108. [PMID: 28338606 PMCID: PMC5406855 DOI: 10.3390/genes8040108] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/16/2017] [Accepted: 03/21/2017] [Indexed: 01/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by defects in the DMD gene and results in progressive wasting of skeletal and cardiac muscle due to an absence of functional dystrophin. Cardiomyopathy is prominent in DMD patients, and contributes significantly to mortality. This is particularly true following respiratory interventions that reduce death rate and increase ambulation and consequently cardiac load. Cardiomyopathy shows an increasing prevalence with age and disease progression, and over 95% of patients exhibit dilated cardiomyopathy by the time they reach adulthood. Development of the myopathy is complex, and elevations in intracellular calcium, functional muscle ischemia, and mitochondrial dysfunction characterise the pathophysiology. Current therapies are limited to treating symptoms of the disease and there is therefore an urgent need to treat the underlying genetic defect. Several novel therapies are outlined here, and the unprecedented success of phosphorodiamidate morpholino oligomers (PMOs) in preclinical and clinical studies is overviewed.
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Affiliation(s)
- Victoria P A Johnstone
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
| | - Helena M Viola
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
| | - Livia C Hool
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
- Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia.
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30
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Milani-Nejad N, Schultz EJ, Slabaugh JL, Janssen PML, Rafael-Fortney JA. Myocardial Contractile Dysfunction Is Present without Histopathology in a Mouse Model of Limb-Girdle Muscular Dystrophy-2F and Is Prevented after Claudin-5 Virotherapy. Front Physiol 2016; 7:539. [PMID: 27999547 PMCID: PMC5138189 DOI: 10.3389/fphys.2016.00539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/27/2016] [Indexed: 01/18/2023] Open
Abstract
Mutations in several members of the dystrophin glycoprotein complex lead to skeletal and cardiomyopathies. Cardiac care for these muscular dystrophies consists of management of symptoms with standard heart medications after detection of reduced whole heart function. Recent evidence from both Duchenne muscular dystrophy patients and animal models suggests that myocardial dysfunction is present before myocardial damage or deficiencies in whole heart function, and that treatment prior to heart failure symptoms may be beneficial. To determine whether this same early myocardial dysfunction is present in other muscular dystrophy cardiomyopathies, we conducted a physiological assessment of cardiac function at the tissue level in the δ-sarcoglycan null mouse model (Sgcd−/−) of Limb-girdle muscular dystrophy type 2F. Baseline cardiac contractile force measurements using ex vivo intact linear muscle preparations, were severely depressed in these mice without the presence of histopathology. Virotherapy withclaudin-5 prevents the onset of cardiomyopathy in another muscular dystrophy model. After virotherapy with claudin-5, the cardiac contractile force deficits in Sgcd−/− mice are no longer significant. These studies suggest that screening Limb-girdle muscular dystrophy patients using methods that detect earlier functional changes may provide a longer therapeutic window for cardiac care.
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Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Medical Scientist Training Program and Biomedical Sciences Graduate Program, The Ohio State University Wexner Medical CenterColumbus, OH, USA
| | - Eric J Schultz
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Department of Molecular and Cellular Biochemistry, The Ohio State University Wexner Medical CenterColumbus, OH, USA
| | - Jessica L Slabaugh
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical CenterColumbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical CenterColumbus, OH, USA
| | - Jill A Rafael-Fortney
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical CenterColumbus, OH, USA; Department of Molecular and Cellular Biochemistry, The Ohio State University Wexner Medical CenterColumbus, OH, USA
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Hammers DW, Sleeper MM, Forbes SC, Shima A, Walter GA, Sweeney HL. Tadalafil Treatment Delays the Onset of Cardiomyopathy in Dystrophin-Deficient Hearts. J Am Heart Assoc 2016; 5:JAHA.116.003911. [PMID: 27506543 PMCID: PMC5015305 DOI: 10.1161/jaha.116.003911] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background Cardiomyopathy is a leading cause of mortality among Duchenne muscular dystrophy patients and lacks effective therapies. Phosphodiesterase type 5 is implicated in dystrophic pathology, and the phosphodiesterase type 5 inhibitor tadalafil has recently been studied in a clinical trial for Duchenne muscular dystrophy. Methods and Results Tadalafil was evaluated for the prevention of cardiomyopathy in the mdx mouse and golden retriever muscular dystrophy dog models of Duchenne muscular dystrophy. Tadalafil blunted the adrenergic response in mdx hearts during a 30‐minute dobutamine challenge, which coincided with cardioprotective signaling, reduced induction of μ‐calpain levels, and decreased sarcomeric protein proteolysis. Dogs with golden retriever muscular dystrophy began daily tadalafil treatment prior to detectable cardiomyopathy and demonstrated preserved cardiac function, as assessed by echocardiography and magnetic resonance imaging at ages 18, 21, and 25 months. Tadalafil treatment improved golden retriever muscular dystrophy histopathological features, decreased levels of the cation channel TRPC6, increased total threonine phosphorylation status of TRPC6, decreased m‐calpain levels and indicators of calpain target proteolysis, and elevated levels of utrophin. In addition, we showed that Duchenne muscular dystrophy patient myocardium exhibited increased TRPC6, m‐calpain, and calpain cleavage products compared with control human myocardium. Conclusions Prophylactic use of tadalafil delays the onset of dystrophic cardiomyopathy, which is likely attributed to modulation of TRPC6 levels and permeability and inhibition of protease content and activity. Consequently, phosphodiesterase type 5 inhibition is a candidate therapy for slowing the development of cardiomyopathy in Duchenne muscular dystrophy patients.
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Affiliation(s)
- David W Hammers
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA Pharmacology & Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of Medicine, Gainesville, FL
| | - Margaret M Sleeper
- Myology Institute, University of Florida College of Medicine, Gainesville, FL Clinical Studies, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA Small Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, FL
| | - Sean C Forbes
- Myology Institute, University of Florida College of Medicine, Gainesville, FL Physical Therapy, University of Florida, Gainesville, FL
| | - Ai Shima
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Glenn A Walter
- Myology Institute, University of Florida College of Medicine, Gainesville, FL Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL
| | - H Lee Sweeney
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA Pharmacology & Therapeutics, University of Florida College of Medicine, Gainesville, FL Myology Institute, University of Florida College of Medicine, Gainesville, FL
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100-fold but not 50-fold dystrophin overexpression aggravates electrocardiographic defects in the mdx model of Duchenne muscular dystrophy. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16045. [PMID: 27419194 PMCID: PMC4934459 DOI: 10.1038/mtm.2016.45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/17/2016] [Accepted: 05/18/2016] [Indexed: 12/18/2022]
Abstract
Dystrophin gene replacement holds the promise of treating Duchenne muscular dystrophy. Supraphysiological expression is a concern for all gene therapy studies. In the case of Duchenne muscular dystrophy, Chamberlain and colleagues found that 50-fold overexpression did not cause deleterious side effect in skeletal muscle. To determine whether excessive dystrophin expression in the heart is safe, we studied two lines of transgenic mdx mice that selectively expressed a therapeutic minidystrophin gene in the heart at 50-fold and 100-fold of the normal levels. In the line with 50-fold overexpression, minidystrophin showed sarcolemmal localization and electrocardiogram abnormalities were corrected. However, in the line with 100-fold overexpression, we not only detected sarcolemmal minidystrophin expression but also observed accumulation of minidystrophin vesicles in the sarcoplasm. Excessive minidystrophin expression did not correct tachycardia, a characteristic feature of Duchenne muscular dystrophy. Importantly, several electrocardiogram parameters (QT interval, QRS duration and the cardiomyopathy index) became worse than that of mdx mice. Our data suggests that the mouse heart can tolerate 50-fold minidystrophin overexpression, but 100-fold overexpression leads to cardiac toxicity.
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Huard J, Mu X, Lu A. Evolving paradigms in clinical pharmacology and therapeutics for the treatment of Duchenne muscular dystrophy. Clin Pharmacol Ther 2016; 100:142-6. [DOI: 10.1002/cpt.379] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/06/2016] [Indexed: 11/10/2022]
Affiliation(s)
- J Huard
- Department of Orthopedic Surgery, McGovern Medical School; University of Texas Health Science Center at Houston; Houston Texas USA
- Steadman Philippon Research Institute; Vail Colorado USA
- Brown Foundation Institute of Molecular Medicine; Center for Tissue Engineering and Aging Research; Houston Texas USA
| | - X Mu
- Department of Orthopedic Surgery, McGovern Medical School; University of Texas Health Science Center at Houston; Houston Texas USA
- Steadman Philippon Research Institute; Vail Colorado USA
- Brown Foundation Institute of Molecular Medicine; Center for Tissue Engineering and Aging Research; Houston Texas USA
| | - A Lu
- Department of Orthopedic Surgery, McGovern Medical School; University of Texas Health Science Center at Houston; Houston Texas USA
- Steadman Philippon Research Institute; Vail Colorado USA
- Brown Foundation Institute of Molecular Medicine; Center for Tissue Engineering and Aging Research; Houston Texas USA
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Pan H, Vojnits K, Liu TT, Meng F, Yang L, Wang Y, Huard J, Cox CS, Lally KP, Li Y. MMP1 gene expression enhances myoblast migration and engraftment following implanting into mdx/SCID mice. Cell Adh Migr 2016. [PMID: 26223276 DOI: 10.4161/19336918.2014.983799] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Myoblast transplantation (MT) is a method to introduce healthy genes into abnormal skeletal muscle. It has been considered as a therapeutic modality in the last few decades for diseases such as Duchenne Muscular Dystrophy (DMD). However, challenges including cell death and poor graft engraftment have limited its application. The current experiment utilizes MMP1 gene transfer to improve the efficacy of myoblast transplantation into the diseased dystrophic skeletal muscle of mdx mice. Our results indicated that MMP1 expression can promote myogenic differentiation and fusion capacities, increase migration of MMP1 expressing myoblasts in vitro, as well as improve engraftment of dystrophin positive myofibers in vivo. Taken together, our observation suggests that the addition of MMP1 can overcome limitations in MT and improve its clinical efficacy.
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Affiliation(s)
- Haiying Pan
- a Department of Pediatric Surgery ; University of Texas Medical School at Houston ; Houston , TX USA
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Abstract
Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the mouse provides great potential to explore cardiac function at the molecular level. The mouse's small size does present some challenges in regards to performing detailed cardiac phenotyping. Miniaturization and other advancements in technology have made many methods of cardiac assessment possible in the mouse. Of these, the simultaneous collection of pressure and volume data provides a detailed picture of cardiac function that is not available through any other modality. Here a detailed procedure for the collection of pressure-volume loop data is described. Included is a discussion of the principles underlying the measurements and the potential sources of error. Anesthetic management and surgical approaches are discussed in great detail as they are both critical to obtaining high quality hemodynamic measurements. The principles of hemodynamic protocol development and relevant aspects of data analysis are also addressed.
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Affiliation(s)
- DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota;
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36
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Barnabei MS, Sjaastad FV, Townsend D, Bedada FB, Metzger JM. Severe dystrophic cardiomyopathy caused by the enteroviral protease 2A-mediated C-terminal dystrophin cleavage fragment. Sci Transl Med 2016; 7:294ra106. [PMID: 26136477 DOI: 10.1126/scitranslmed.aaa4804] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Enterovirus infection can cause severe cardiomyopathy in humans. The virus-encoded 2A protease is known to cleave the cytoskeletal protein dystrophin. It is unclear, however, whether cardiomyopathy results from the loss of dystrophin or is due to the emergence of a dominant-negative dystrophin cleavage product. We show for the first time that the 2A protease-mediated carboxyl-terminal dystrophin cleavage fragment (CtermDys) is sufficient to cause marked dystrophic cardiomyopathy. The sarcolemma-localized CtermDys fragment caused myocardial fibrosis, heightened susceptibility to myocardial ischemic injury, and increased mortality during cardiac stress testing in vivo. CtermDys cardiomyopathy was more severe than in hearts completely lacking dystrophin. In vivo titration of CtermDys peptide content revealed an inverse relationship between the decay of membrane-bound CtermDys and the restoration of full-length dystrophin at the sarcolemma, in support of a physiologically relevant loss of dystrophin function in this model. CtermDys gene titration and dystrophin replacement studies further established a target threshold of 50% membrane-bound intact dystrophin necessary to prevent mice from CtermDys cardiomyopathy. Conversely, the NtermDys fragment did not compete with dystrophin and had no pathological effect. Thus, CtermDys must be localized to the sarcolemma, with intact dystrophin <50% of normal levels, to exert dominant-negative peptide-dependent cardiomyopathy. These data support a two-hit dominant-negative disease mechanism where membrane-associated CtermDys severs the link to cortical actin and inhibits both full-length dystrophin and compensatory utrophin from binding at the membrane. Therefore, membrane-bound CtermDys is a new potential translational target for virus-mediated cardiomyopathy.
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Affiliation(s)
- Matthew S Barnabei
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Frances V Sjaastad
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Fikru B Bedada
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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Stelter Z, Strakova J, Yellamilli A, Fischer K, Sharpe K, Townsend D. Hypoxia-induced cardiac injury in dystrophic mice. Am J Physiol Heart Circ Physiol 2016; 310:H938-48. [PMID: 26851247 DOI: 10.1152/ajpheart.00917.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/02/2016] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a disease of progressive destruction of striated muscle, resulting in muscle weakness with progressive respiratory and cardiac failure. Respiratory and cardiac disease are the leading causes of death in DMD patients. Previous studies have suggested an important link between cardiac dysfunction and hypoxia in the dystrophic heart; these studies aim to understand the mechanism underlying this connection. Here we demonstrate that anesthetized dystrophic mice display significant mortality following acute exposure to hypoxia. This increased mortality is associated with a significant metabolic acidosis, despite having significantly higher levels of arterial Po2 Chronic hypoxia does not result in mortality, but rather is characterized by marked cardiac fibrosis. Studies in isolated hearts reveal that the contractile function of dystrophic hearts is highly susceptible to short bouts of ischemia, but these hearts tolerate prolonged acidosis better than wild-type hearts, indicating an increased sensitivity of the dystrophic heart to hypoxia. Dystrophic hearts display decreased cardiac efficiency and oxygen extraction. Isolated dystrophic cardiomyocytes and hearts have normal levels of FCCP-induced oxygen consumption, and mitochondrial morphology and content are normal in the dystrophic heart. These studies demonstrate reductions in cardiac efficiency and oxygen extraction of the dystrophic heart. The underlying cause of this reduced oxygen extraction is not clear; however, the current studies suggest that large disruptions of mitochondrial respiratory function or coronary flow regulation are not responsible. This finding is significant, as hypoxia is a common and largely preventable component of DMD that may contribute to the progression of the cardiac disease in DMD patients.
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Affiliation(s)
- Zachary Stelter
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Jana Strakova
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Amritha Yellamilli
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Kaleb Fischer
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Katharine Sharpe
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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Yue Y, Binalsheikh IM, Leach SB, Domeier TL, Duan D. Prospect of gene therapy for cardiomyopathy in hereditary muscular dystrophy. Expert Opin Orphan Drugs 2015; 4:169-183. [PMID: 27340611 DOI: 10.1517/21678707.2016.1124039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Cardiac involvement is a common feature in muscular dystrophies. It presents as heart failure and/or arrhythmia. Traditionally, dystrophic cardiomyopathy is treated with symptom-relieving medications. Identification of disease-causing genes and investigation on pathogenic mechanisms have opened new opportunities to treat dystrophic cardiomyopathy with gene therapy. Replacing/repairing the mutated gene and/or targeting the pathogenic process/mechanisms using alternative genes may attenuate heart disease in muscular dystrophies. AREAS COVERED Duchenne muscular dystrophy is the most common muscular dystrophy. Duchenne cardiomyopathy has been the primary focus of ongoing dystrophic cardiomyopathy gene therapy studies. Here, we use Duchenne cardiomyopathy gene therapy to showcase recent developments and to outline the path forward. We also discuss gene therapy status for cardiomyopathy associated with limb-girdle and congenital muscular dystrophies, and myotonic dystrophy. EXPERT OPINION Gene therapy for dystrophic cardiomyopathy has taken a slow but steady path forward. Preclinical studies over the last decades have addressed many fundamental questions. Adeno-associated virus-mediated gene therapy has significantly improved the outcomes in rodent models of Duchenne and limb girdle muscular dystrophies. Validation of these encouraging results in large animal models will pave the way to future human trials.
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Affiliation(s)
- Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri
| | | | - Stacey B Leach
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri
| | - Timothy L Domeier
- Department of Medical Physiology and Pharmacology, School of Medicine, University of Missouri
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri; Department of Neurology, School of Medicine, University of Missouri
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McGreevy JW, Hakim CH, McIntosh MA, Duan D. Animal models of Duchenne muscular dystrophy: from basic mechanisms to gene therapy. Dis Model Mech 2015; 8:195-213. [PMID: 25740330 PMCID: PMC4348559 DOI: 10.1242/dmm.018424] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disorder. It is caused by loss-of-function mutations in the dystrophin gene. Currently, there is no cure. A highly promising therapeutic strategy is to replace or repair the defective dystrophin gene by gene therapy. Numerous animal models of DMD have been developed over the last 30 years, ranging from invertebrate to large mammalian models. mdx mice are the most commonly employed models in DMD research and have been used to lay the groundwork for DMD gene therapy. After ~30 years of development, the field has reached the stage at which the results in mdx mice can be validated and scaled-up in symptomatic large animals. The canine DMD (cDMD) model will be excellent for these studies. In this article, we review the animal models for DMD, the pros and cons of each model system, and the history and progress of preclinical DMD gene therapy research in the animal models. We also discuss the current and emerging challenges in this field and ways to address these challenges using animal models, in particular cDMD dogs.
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Affiliation(s)
- Joe W McGreevy
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Chady H Hakim
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Mark A McIntosh
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA Department of Neurology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is a relatively common inherited disorder caused by defective expression of the protein dystrophin. The most direct approach to treating this disease would be to restore dystrophin production in muscle. Recent progress has greatly increased the prospects for successful gene therapy of DMD, and here we summarize the most promising developments. AREAS COVERED Gene transfer using vectors derived from adeno-associated virus (AAV) has emerged as a promising method to restore dystrophin production in muscles bodywide, and represents a treatment option applicable to all DMD patients. Using information gleaned from PubMed searches of the literature, attendance at scientific conferences and results from our own lab, we provide an overview of the potential for gene therapy of DMD using AAV vectors including a summary of promising developments and issues that need to be resolved prior to large-scale therapeutic implementation. EXPERT OPINION Of the many approaches being pursued to treat DMD and BMD, gene therapy based on AAV-mediated delivery of microdystrophin is the most direct and promising method to treat the cause of the disorder. The major challenges to this approach are ensuring that microdystrophin can be delivered safely and efficiently without eliciting an immune response.
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Affiliation(s)
- Julian Ramos
- University of Washington, Wellstone Muscular Dystrophy Research Center, Department of Neurology, Seattle, WA, 98195-7720, USA
| | - Jeffrey S Chamberlain
- University of Washington, Wellstone Muscular Dystrophy Research Center, Department of Neurology, Seattle, WA, 98195-7720, USA
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Abstract
Duchenne muscular dystrophy (DMD) is a progressive striated muscle disease that is characterized by skeletal muscle weakness with progressive respiratory and cardiac failure. Together respiratory and cardiac disease account for the majority of mortality in the DMD patient population. However, little is known regarding the effects of respiratory dysfunction on the dystrophic heart. The studies described here examine the effects of acute hypoxia on cardiac function. These studies demonstrate, for the first time, that a mouse model of DMD displays significant mortality following acute exposure to hypoxia. This mortality is characterized by a steady decline in systolic function. Retrospective analysis reveals that significant decreases in diastolic dysfunction, especially in the right ventricle, precede the decline in systolic pressure. The initial hemodynamic response to acute hypoxia in the mouse is similar to that observed in larger species, with significant increases in right ventricular afterload and decreases in left ventricular preload being observed. Significant increases in heart rate and contractility suggest hypoxia-induced activation of the sympathetic nervous system. These studies provide evidence that while hypoxia presents significant hemodynamic challenges to the dystrophic right ventricle, global cardiac dysfunction precedes hypoxia-induced mortality in the dystrophic heart. These findings are clinically relevant as the respiratory insufficiency evident in patients with DMD results in significant bouts of hypoxia. The results of these studies indicate that hypoxia may contribute to the acceleration of the heart disease in DMD patients. Importantly, hypoxia can be avoided through the use of ventilatory support.
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Affiliation(s)
- DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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Blain AM, Greally E, Laval SH, Blamire AM, MacGowan GA, Straub VW. Assessment of ventricular function in mouse models of muscular dystrophy: A comparison of MRI with conductance catheter. Neuromuscul Disord 2015; 25:24-31. [DOI: 10.1016/j.nmd.2014.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/17/2014] [Accepted: 09/29/2014] [Indexed: 10/24/2022]
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Meyers TA, Townsend D. Early right ventricular fibrosis and reduction in biventricular cardiac reserve in the dystrophin-deficient mdx heart. Am J Physiol Heart Circ Physiol 2014; 308:H303-15. [PMID: 25485898 DOI: 10.1152/ajpheart.00485.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a progressive disease of striated muscle deterioration. Respiratory and cardiac muscle dysfunction are particularly clinically relevant because they result in the leading causes of death in DMD patients. Despite the clinical and physiological significance of these systems, little has been done to understand the cardiorespiratory interaction in DMD. We show here that prior to the onset of global cardiac dysfunction, dystrophin-deficient mdx mice have increased cardiac fibrosis with the right ventricle being particularly affected. Using a novel biventricular cardiac catheterization technique coupled with cardiac stress testing, we demonstrate that both the right and left ventricles have significant reductions in both systolic and diastolic function in response to dobutamine. Unstimulated cardiac function is relatively normal except for a significant reduction in the ventricular pressure transient duration compared with controls. These biventricular analyses also reveal the absence of a dobutamine-induced increase in isovolumic relaxation in the right ventricle of control hearts. Simultaneous assessment of biventricular pressure demonstrates a dobutamine-dependent enhancement of coupling between the ventricles in control mice, which is absent in mdx mice. Furthermore, studies probing the passive-extension properties of the left ventricle demonstrate that the mdx heart is significantly more compliant compared with age-matched C57BL/10 hearts, which have an age-dependent stiffening that is completely absent from dystrophic hearts. These new results indicate that right ventricular fibrosis is an early indicator of the development of dystrophic cardiomyopathy, suggesting a mechanism by which respiratory insufficiency may accelerate the development of heart failure in DMD.
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Affiliation(s)
- Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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Townsend D. Finding the sweet spot: assembly and glycosylation of the dystrophin-associated glycoprotein complex. Anat Rec (Hoboken) 2014; 297:1694-705. [PMID: 25125182 PMCID: PMC4135523 DOI: 10.1002/ar.22974] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/27/2014] [Indexed: 01/12/2023]
Abstract
The dystrophin-associated glycoprotein complex (DGC) is a collection of glycoproteins that are essential for the normal function of striated muscle and many other tissues. Recent genetic studies have implicated the components of this complex in over a dozen forms of muscular dystrophy. Furthermore, disruption of the DGC has been implicated in many forms of acquired disease. This review aims to summarize the current state of knowledge regarding the processing and assembly of dystrophin-associated proteins with a focus primarily on the dystroglycan heterodimer and the sarcoglycan complex. These proteins form the transmembrane portion of the DGC and undergo a complex multi-step processing with proteolytic cleavage, differential assembly, and both N- and O-glycosylation. The enzymes responsible for this processing and a model describing the sequence and subcellular localization of these events are discussed.
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Affiliation(s)
- Dewayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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45
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Strakova J, Dean JD, Sharpe KM, Meyers TA, Odom GL, Townsend D. Dystrobrevin increases dystrophin's binding to the dystrophin-glycoprotein complex and provides protection during cardiac stress. J Mol Cell Cardiol 2014; 76:106-15. [PMID: 25158611 DOI: 10.1016/j.yjmcc.2014.08.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 08/14/2014] [Accepted: 08/16/2014] [Indexed: 01/05/2023]
Abstract
Duchenne muscular dystrophy is a fatal progressive disease of both cardiac and skeletal muscle resulting from the mutations in the DMD gene and loss of the protein dystrophin. Alpha-dystrobrevin (α-DB) tightly associates with dystrophin but the significance of this interaction within cardiac myocytes is poorly understood. In the current study, the functional role of α-DB in cardiomyocytes and its implications for dystrophin function are examined. Cardiac stress testing demonstrated significant heart disease in α-DB null (adbn(-/-)) mice, which displayed mortality and lesion sizes that were equivalent to those seen in dystrophin-deficient mdx mice. Despite normal expression and subcellular localization of dystrophin in the adbn(-/-) heart, there is a significant decrease in the strength of dystrophin's interaction with the membrane-bound dystrophin-associated glycoprotein complex (DGC). A similar weakening of the dystrophin-membrane interface was observed in mice lacking the sarcoglycan complex. Cardiomyocytes from adbn(-/-) mice were smaller and responded less to adrenergic receptor induced hypertrophy. The basal decrease in size could not be attributed to aberrant Akt activation. In addition, the organization of the microtubule network was significantly altered in adbn(-/-) cardiac myocytes, while the total expression of tubulin was unchanged in adbn(-/-) hearts. These studies demonstrate that α-DB is a multifunctional protein that increases dystrophin's binding to the dystrophin-glycoprotein complex, and is critical for the full functionality of dystrophin.
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Affiliation(s)
- Jana Strakova
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Jon D Dean
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Katharine M Sharpe
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Guy L Odom
- Department of Neurology, University of Washington, Seattle, WA, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.
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Swiderski K, Shaffer SA, Gallis B, Odom GL, Arnett AL, Scott Edgar J, Baum DM, Chee A, Naim T, Gregorevic P, Murphy KT, Moody J, Goodlett DR, Lynch GS, Chamberlain JS. Phosphorylation within the cysteine-rich region of dystrophin enhances its association with β-dystroglycan and identifies a potential novel therapeutic target for skeletal muscle wasting. Hum Mol Genet 2014; 23:6697-711. [PMID: 25082828 DOI: 10.1093/hmg/ddu388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in dystrophin lead to Duchenne muscular dystrophy, which is among the most common human genetic disorders. Dystrophin nucleates assembly of the dystrophin-glycoprotein complex (DGC), and a defective DGC disrupts an essential link between the intracellular cytoskeleton and the basal lamina, leading to progressive muscle wasting. In vitro studies have suggested that dystrophin phosphorylation may affect interactions with actin or syntrophin, yet whether this occurs in vivo or affects protein function remains unknown. Utilizing nanoflow liquid chromatography mass spectrometry, we identified 18 phosphorylated residues within endogenous dystrophin. Mutagenesis revealed that phosphorylation at S3059 enhances the dystrophin-dystroglycan interaction and 3D modeling utilizing the Rosetta software program provided a structural model for how phosphorylation enhances this interaction. These findings demonstrate that phosphorylation is a key mechanism regulating the interaction between dystrophin and the DGC and reveal that posttranslational modification of a single amino acid directly modulates the function of dystrophin.
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Affiliation(s)
- Kristy Swiderski
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Scott A Shaffer
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Byron Gallis
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Guy L Odom
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Andrea L Arnett
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - J Scott Edgar
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Dale M Baum
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Timur Naim
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Paul Gregorevic
- Muscle Biology and Therapeutics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - James Moody
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
| | - David R Goodlett
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Jeffrey S Chamberlain
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
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47
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Barnabei MS, Martindale JM, Townsend D, Metzger JM. Exercise and muscular dystrophy: implications and analysis of effects on musculoskeletal and cardiovascular systems. Compr Physiol 2013; 1:1353-63. [PMID: 23733645 DOI: 10.1002/cphy.c100062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The muscular dystrophies are a heterogeneous collection of progressive, inherited diseases of muscle weakness and degeneration. Although these diseases can vary widely in their etiology and presentation, nearly all muscular dystrophies cause exercise intolerance to some degree. Here, we focus on Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, as a paradigm for the effects of muscle disease on exercise capacity. First described in the mid-1800s, DMD is a rapidly progressive and lethal muscular dystrophy caused by mutations in the dystrophin gene. Dystrophin is a membrane-associated cytoskeletal protein, the loss of which causes numerous cellular defects including mechanical instability of the sarcolemma, increased influx of extracellular calcium, and cell signaling defects. Here, we discuss the physiological basis for exercise intolerance in DMD, focusing on the molecular and cellular defects caused by loss of dystrophin and how these manifest as organ-level dysfunction and reduced exercise capacity. The main focus of this article is the defects present in dystrophin-deficient striated muscle. However, discussion regarding the effects of dystrophin loss on other tissues, including vascular smooth muscle is also included. Collectively, the goal of this article is to summarize the current state of knowledge regarding the mechanistic basis for exercise intolerance in DMD, which may serve as an archetype for other muscular dystrophies and diseases of muscle wasting.
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Affiliation(s)
- Matthew S Barnabei
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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48
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Taghli-Lamallem O, Jagla K, Chamberlain JS, Bodmer R. Mechanical and non-mechanical functions of Dystrophin can prevent cardiac abnormalities in Drosophila. Exp Gerontol 2013; 49:26-34. [PMID: 24231130 DOI: 10.1016/j.exger.2013.10.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 10/22/2013] [Accepted: 10/28/2013] [Indexed: 01/16/2023]
Abstract
Dystrophin-deficiency causes cardiomyopathies and shortens the life expectancy of Duchenne and Becker muscular dystrophy patients. Restoring Dystrophin expression in the heart by gene transfer is a promising avenue to explore as a therapy. Truncated Dystrophin gene constructs have been engineered and shown to alleviate dystrophic skeletal muscle disease, but their potential in preventing the development of cardiomyopathy is not fully understood. In the present study, we found that either the mechanical or the signaling functions of Dystrophin were able to reduce the dilated heart phenotype of Dystrophin mutants in a Drosophila model. Our data suggest that Dystrophin retains some function in fly cardiomyocytes in the absence of a predicted mechanical link to the cytoskeleton. Interestingly, cardiac-specific manipulation of nitric oxide synthase expression also modulates cardiac function, which can in part be reversed by loss of Dystrophin function, further implying a signaling role of Dystrophin in the heart. These findings suggest that the signaling functions of Dystrophin protein are able to ameliorate the dilated cardiomyopathy, and thus might help to improve heart muscle function in micro-Dystrophin-based gene therapy approaches.
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Affiliation(s)
- Ouarda Taghli-Lamallem
- Development and Aging Program, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Rd, Building 7 Room 7125, La Jolla, CA 92037, USA; GReD, INSERM U1103, CNRS UMR6293-Clermont University, Faculty of Medicine 28, Place Henri Dunant, 63000 Clermont-Ferrand, France.
| | - Krzysztof Jagla
- GReD, INSERM U1103, CNRS UMR6293-Clermont University, Faculty of Medicine 28, Place Henri Dunant, 63000 Clermont-Ferrand, France
| | - Jeffrey S Chamberlain
- University of Washington School of Medicine, Department of Neurology, Box 357720, Seattle, WA 98195-7720, USA
| | - Rolf Bodmer
- Development and Aging Program, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Rd, Building 7 Room 7125, La Jolla, CA 92037, USA.
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49
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Asokan A, Samulski RJ. An emerging adeno-associated viral vector pipeline for cardiac gene therapy. Hum Gene Ther 2013; 24:906-13. [PMID: 24164238 PMCID: PMC3815036 DOI: 10.1089/hum.2013.2515] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The naturally occurring adeno-associated virus (AAV) isolates display diverse tissue tropisms in different hosts. Robust cardiac transduction in particular has been reported for certain AAV strains. Successful applications of these AAV strains in preclinical and clinical settings with a focus on treating cardiovascular disease continue to be reported. At the same time, these studies have highlighted challenges such as cross-species variability in AAV tropism, transduction efficiency, and immunity. Continued progress in our understanding of AAV capsid structure and biology has provided the rationale for designing improved vectors that can possibly address these concerns. The current report provides an overview of cardiotropic AAV, existing gaps in our knowledge, and newly engineered AAV strains that are viable candidates for the cardiac gene therapy clinic.
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Affiliation(s)
- Aravind Asokan
- Gene Therapy Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
| | - R. Jude Samulski
- Gene Therapy Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
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50
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Sharpe KM, Premsukh MD, Townsend D. Alterations of dystrophin-associated glycoproteins in the heart lacking dystrophin or dystrophin and utrophin. J Muscle Res Cell Motil 2013; 34:395-405. [PMID: 24096570 DOI: 10.1007/s10974-013-9362-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 09/26/2013] [Indexed: 11/26/2022]
Abstract
Heart disease is a leading cause of death in patients with Duchenne muscular dystrophy (DMD). Patients with DMD lack the protein dystrophin, which is widely expressed in striated muscle. In skeletal muscle, the loss of dystrophin results in dramatically decreased expression of the dystrophin associated glycoprotein complex (DGC). Interestingly, in the heart the DGC is normally expressed without dystrophin; this has been attributed to presence of the dystrophin homologue utrophin. We demonstrate here that neither utrophin nor dystrophin are required for the expression of the cardiac DGC. However, alpha-dystroglycan (α-DG), a major component of the DGC, is differentially glycosylated in dystrophin-(mdx) and dystrophin-/utrophin-(dko) deficient mouse hearts. In both models the altered α-DG retains laminin binding activity, but has an altered localization at the sarcolemma. In hearts lacking both dystrophin and utrophin, the alterations in α-DG glycosylation are even more dramatic with changes in gel migration equivalent to 24 ± 3 kDa. These data show that the absence of dystrophin and utrophin alters the processing of α-DG; however it is not clear if these alterations are a consequence of the loss of a direct interaction with dystrophin/utrophin or results from an indirect response to the presence of severe pathology. Recently there have been great advances in our understanding of the glycosylation of α-DG regarding its role as a laminin receptor. Here we present data that alterations in glycosylation occur in the hearts of animal models of DMD, but these changes do not affect laminin binding. The physiological consequences of these alterations remain unknown, but may have significant implications for the development of therapies for DMD.
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Affiliation(s)
- Katharine M Sharpe
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
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