1
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Hamed M, Chen J, Li Q. Regulation of Dystroglycan Gene Expression in Early Myoblast Differentiation. Front Cell Dev Biol 2022; 10:818701. [PMID: 35330913 PMCID: PMC8940196 DOI: 10.3389/fcell.2022.818701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/04/2022] [Indexed: 11/13/2022] Open
Abstract
Dystroglycan, a component of the dystrophin-associated glycoprotein complex, connects the extracellular matrix and cytoskeleton to maintain muscle membrane integrity. As such, abnormalities of dystroglycan are linked to different types of muscular dystrophies. In an effort to develop therapeutic approaches to re-establish signal integration for muscle repair and homeostasis, we have previously determined that a clinically approved agonist of retinoid X receptor enhances myoblast differentiation through direct regulation of gene expression of the muscle master regulator MyoD. Using comprehensive omics and molecular analyses, we found that dystroglycan gene expression is responsive to retinoid X receptor-selective signaling in early myoblast differentiation. In addition, the dystroglycan gene is a MyoD target, and residue-specific histone acetylation coincides with the occupancy of histone acetyltransferase p300 at the MyoD binding sites. Consequently, the p300 function is important for rexinoid-augmented dystroglycan gene expression. Finally, dystroglycan plays a role in myoblast differentiation. Our study sheds new light on dystroglycan regulation and function in myoblast differentiation and presents a potential avenue for re-establishing signal integration of a specific chromatin state pharmacologically to overcome muscle pathology and identify additional myogenic interactions for therapeutic applications.
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Affiliation(s)
- Munerah Hamed
- Department of Cellular and Molecular Medicine Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jihong Chen
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Qiao Li
- Department of Cellular and Molecular Medicine Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- *Correspondence: Qiao Li,
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2
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Vainzof M, Souza LS, Gurgel-Giannetti J, Zatz M. Sarcoglycanopathies: an update. Neuromuscul Disord 2021; 31:1021-1027. [PMID: 34404573 DOI: 10.1016/j.nmd.2021.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 11/16/2022]
Abstract
Sarcoglycanopathies are the most severe forms of autosomal recessive limb-girdle muscular dystrophies (LGMDs), constituting about 10-25% of LGMDs. The clinical phenotype is variable, but onset is usually in the first decade of life. Patients present muscle hypertrophy, elevated CK, variable muscle weaknesses, and progressive loss of ambulation. Four subtypes are known: LGMDR3, LGMDR4, LGMDR5 and LGMDR6, caused, respectively, by mutations in the SGCA, SGCB,SGCG and SGCD genes. Their four coded proteins, α-SG, ß-SG, λ-SG and δ-SG are part of the dystrophin-glycoprotein complex (DGC) present in muscle sarcolemma, which acts as a linker between the cytoskeleton of the muscle fiber and the extracellular matrix, providing mechanical support to the sarcolemma during myofiber contraction. Many different mutations have already been identified in all the sarcoglycan genes, with a predominance of some mutations in different populations. The diagnosis is currently based on the molecular screening for these mutations. Therapeutic approaches include the strategy of gene replacement mediated by a vector derived from adeno-associated virus (AAV). Pre-clinical studies have shown detectable levels of SG proteins in the muscle, and some improvement in the phenotype, in animal models. Therapeutic trials in humans are ongoing.
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Affiliation(s)
- Mariz Vainzof
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil.
| | - Lucas S Souza
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Juliana Gurgel-Giannetti
- Department of Pediatrics, Service of Neuropediatrics from Federal, University of Minas Gerais, Belo Horizonte, Brazil
| | - Mayana Zatz
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
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3
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Ban J, Beqaj B, Phillips WD. Vector-mediated expression of muscle specific kinase restores specific force to muscles in the mdx mouse model of Duchenne muscular dystrophy. Exp Physiol 2021; 106:1794-1805. [PMID: 34114278 DOI: 10.1113/ep089439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 06/08/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The (dystrophin-deficient) muscles of mdx mice generate less contractile force per cross-sectional area (specific force) than those of healthy wild-type mice: what is the influence of muscle specific kinase (MuSK) upon the properties of the tibialis anterior (TA) muscle in mdx mice? What is the main finding and its importance? Injection of adeno-associated viral vector encoding MuSK into the TA muscle of young mdx mice increased the specific force of the muscle, suggesting the MuSK signalling system has the potential to restore healthy growth to dystrophin-deficient muscles. ABSTRACT In the mdx mouse model of Duchenne muscular dystrophy, muscle fibres are fragile and prone to injury and degeneration. Compared to wild-type mice, muscles of mdx mice also develop less specific force (contractile force/cross-sectional area). We recently reported that injecting adeno-associated viral vector encoding muscle specific kinase (AAV-MuSK) into muscles of mdx mice increased utrophin expression and made the muscles more resistant to acute stretch-induced injury. Here we injected AAV-MuSK unilaterally into the tibialis anterior muscle of mdx mice at a younger age (4 weeks), and recorded contraction force from the muscles in situ at 12 weeks of age. Compared to contralateral empty-vector control muscles, muscles injected with AAV-MuSK produced 28% greater specific force (P = 0.0005). They did not undergo the compensatory hypertrophy that normally occurs in muscles of mdx mice. Injection of AAV encoding rapsyn (a downstream effector of MuSK signalling) caused no such improvement in muscle strength. Muscles injected with AAV-MuSK displayed a 10% reduction in the number of fibres with centralized nuclei (P = 0.0015). Our results in mdx mice suggest that elevating the expression of MuSK can reduce the incidence of muscle fibre regeneration and improve the strength of dystrophin-deficient muscles.
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Affiliation(s)
- Joanne Ban
- Physiology and Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - Besa Beqaj
- Physiology and Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - William D Phillips
- Physiology and Bosch Institute, University of Sydney, Sydney, NSW, Australia
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4
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Kim K, Gu Y, Wang CY, Clifford B, Huang S, Liang ZP, Yu X. Quantification of creatine kinase reaction rate in mouse hindlimb using phosphorus-31 magnetic resonance spectroscopic fingerprinting. NMR IN BIOMEDICINE 2021; 34:e4435. [PMID: 33111456 PMCID: PMC8324327 DOI: 10.1002/nbm.4435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/10/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
The goal of this study was to evaluate the accuracy, reproducibility, and efficiency of a 31 P magnetic resonance spectroscopic fingerprinting (31 P-MRSF) method for fast quantification of the forward rate constant of creatine kinase (CK) in mouse hindlimb. The 31 P-MRSF method acquired spectroscopic fingerprints using interleaved acquisition of phosphocreatine (PCr) and γATP with ramped flip angles and a saturation scheme sensitive to chemical exchange between PCr and γATP. Parameter estimation was performed by matching the acquired fingerprints to a dictionary of simulated fingerprints generated from the Bloch-McConnell model. The accuracy of 31 P-MRSF measurements was compared with the magnetization transfer (MT-MRS) method in mouse hindlimb at 9.4 T (n = 8). The reproducibility of 31 P-MRSF was also assessed by repeated measurements. Estimation of the CK rate constant using 31 P-MRSF (0.39 ± 0.03 s-1 ) showed a strong agreement with that using MT-MRS measurements (0.40 ± 0.05 s-1 ). Variations less than 10% were achieved with 2 min acquisition of 31 P-MRSF data. Application of the 31 P-MRSF method to mice subjected to an electrical stimulation protocol detected an increase in CK rate constant in response to stimulation-induced muscle contraction. These results demonstrated the potential of the 31 P-MRSF framework for rapid, accurate, and reproducible quantification of the chemical exchange rate of CK in vivo.
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Affiliation(s)
- Kihwan Kim
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Yuning Gu
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Charlie Y. Wang
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Bryan Clifford
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Sherry Huang
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Zhi-Pei Liang
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Xin Yu
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
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5
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Abstract
Skeletal muscle fibres are multinucleated cells that contain postmitotic nuclei (i.e. they are no longer able to divide) and perform muscle contraction. They are formed by fusion of muscle precursor cells, and grow into elongating myofibres by the addition of further precursor cells, called satellite cells, which are also responsible for regeneration following injury. Skeletal muscle regeneration occurs in most muscular dystrophies in response to necrosis of muscle fibres. However, the complex environment within dystrophic skeletal muscle, which includes inflammatory cells, fibroblasts and fibro-adipogenic cells, together with the genetic background of the in vivo model and the muscle being studied, complicates the interpretation of laboratory studies on muscular dystrophies. Many genes are expressed in satellite cells and in other tissues, which makes it difficult to determine the molecular cause of various types of muscular dystrophies. Here, and in the accompanying poster, we discuss our current knowledge of the cellular mechanisms that govern the growth and regeneration of skeletal muscle, and highlight the defects in satellite cell function that give rise to muscular dystrophies. Summary: The mechanisms of skeletal muscle development, growth and regeneration are described. We discuss whether these processes are dysregulated in inherited muscle diseases and identify pathways that may represent therapeutic targets.
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Affiliation(s)
- Jennifer Morgan
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK .,National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London WC1N 1EH, UK
| | - Terence Partridge
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.,National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London WC1N 1EH, UK.,Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Ave NW, Washington, DC 20010, USA
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6
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Nguyen Q, Yokota T. Antisense oligonucleotides for the treatment of cardiomyopathy in Duchenne muscular dystrophy. Am J Transl Res 2019; 11:1202-1218. [PMID: 30972156 PMCID: PMC6456507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive fatal neuromuscular disorder characterized by progressive muscle degeneration which affects one in 3500-5000 males born worldwide. DMD is caused by loss-of-function mutations in the dystrophin (DMD) gene encoding for dystrophin, a cytoskeletal protein that supports the structural integrity of myofibers during cycles of muscle contraction and relaxation. DMD patients do not only experience skeletal muscle deterioration but also severe cardiomyopathy, which is recognized as the current leading cause of death for the disease. Among the therapies being developed, exon skipping using antisense oligonucleotides (AOs) is one of the most promising approaches. AOs effectively restore dystrophin expression in skeletal muscles; however, they are highly inefficient in the heart due to endosomal entrapment. Improving skeletal muscle function without restoring dystrophin expression in cardiac tissue may exacerbate cardiomyopathy due to increased voluntary activity. This review consolidates the preclinical antisense approaches to improve dystrophin restoration, with a special focus on the heart.
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Affiliation(s)
- Quynh Nguyen
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta8812-112 St., Edmonton, AB T6G 2H7, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta8812-112 St., Edmonton, AB T6G 2H7, Canada
- The Friends of Garret Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair8812-112 St., Edmonton, AB T6G 2H7, Canada
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7
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Heydemann A. Skeletal Muscle Metabolism in Duchenne and Becker Muscular Dystrophy-Implications for Therapies. Nutrients 2018; 10:nu10060796. [PMID: 29925809 PMCID: PMC6024668 DOI: 10.3390/nu10060796] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/14/2018] [Accepted: 06/16/2018] [Indexed: 02/06/2023] Open
Abstract
The interactions between nutrition and metabolism and skeletal muscle have long been known. Muscle is the major metabolic organ—it consumes more calories than other organs—and therefore, there is a clear need to discuss these interactions and provide some direction for future research areas regarding muscle pathologies. In addition, new experiments and manuscripts continually reveal additional highly intricate, reciprocal interactions between metabolism and muscle. These reciprocal interactions include exercise, age, sex, diet, and pathologies including atrophy, hypoxia, obesity, diabetes, and muscle myopathies. Central to this review are the metabolic changes that occur in the skeletal muscle cells of muscular dystrophy patients and mouse models. Many of these metabolic changes are pathogenic (inappropriate body mass changes, mitochondrial dysfunction, reduced adenosine triphosphate (ATP) levels, and increased Ca2+) and others are compensatory (increased phosphorylated AMP activated protein kinase (pAMPK), increased slow fiber numbers, and increased utrophin). Therefore, reversing or enhancing these changes with therapies will aid the patients. The multiple therapeutic targets to reverse or enhance the metabolic pathways will be discussed. Among the therapeutic targets are increasing pAMPK, utrophin, mitochondrial number and slow fiber characteristics, and inhibiting reactive oxygen species. Because new data reveals many additional intricate levels of interactions, new questions are rapidly arising. How does muscular dystrophy alter metabolism, and are the changes compensatory or pathogenic? How does metabolism affect muscular dystrophy? Of course, the most profound question is whether clinicians can therapeutically target nutrition and metabolism for muscular dystrophy patient benefit? Obtaining the answers to these questions will greatly aid patients with muscular dystrophy.
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Affiliation(s)
- Ahlke Heydemann
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA.
- Center for Cardiovascular Research, The University of Illinois at Chicago, Chicago, IL 60612, USA.
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8
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Rodrigues M, Echigoya Y, Fukada SI, Yokota T. Current Translational Research and Murine Models For Duchenne Muscular Dystrophy. J Neuromuscul Dis 2018; 3:29-48. [PMID: 27854202 PMCID: PMC5271422 DOI: 10.3233/jnd-150113] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder characterized by progressive muscle degeneration. Mutations in the DMD gene result in the absence of dystrophin, a protein required for muscle strength and stability. Currently, there is no cure for DMD. Since murine models are relatively easy to genetically manipulate, cost effective, and easily reproducible due to their short generation time, they have helped to elucidate the pathobiology of dystrophin deficiency and to assess therapies for treating DMD. Recently, several murine models have been developed by our group and others to be more representative of the human DMD mutation types and phenotypes. For instance, mdx mice on a DBA/2 genetic background, developed by Fukada et al., have lower regenerative capacity and exhibit very severe phenotype. Cmah-deficient mdx mice display an accelerated disease onset and severe cardiac phenotype due to differences in glycosylation between humans and mice. Other novel murine models include mdx52, which harbors a deletion mutation in exon 52, a hot spot region in humans, and dystrophin/utrophin double-deficient (dko), which displays a severe dystrophic phenotype due the absence of utrophin, a dystrophin homolog. This paper reviews the pathological manifestations and recent therapeutic developments in murine models of DMD such as standard mdx (C57BL/10), mdx on C57BL/6 background (C57BL/6-mdx), mdx52, dystrophin/utrophin double-deficient (dko), mdxβgeo, Dmd-null, humanized DMD (hDMD), mdx on DBA/2 background (DBA/2-mdx), Cmah-mdx, and mdx/mTRKO murine models.
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Affiliation(s)
- Merryl Rodrigues
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Yusuke Echigoya
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - So-Ichiro Fukada
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada.,Muscular Dystrophy Canada Research Chair, Edmonton, Alberta, Canada
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9
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Hightower RM, Alexander MS. Genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies. Muscle Nerve 2018; 57:6-15. [PMID: 28877560 PMCID: PMC5759757 DOI: 10.1002/mus.25953] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2017] [Indexed: 01/05/2023]
Abstract
Muscular dystrophy is defined as the progressive wasting of skeletal muscles that is caused by inherited or spontaneous genetic mutations. Next-generation sequencing has greatly improved the accuracy and speed of diagnosis for different types of muscular dystrophy. Advancements in depth of coverage, convenience, and overall reduced cost have led to the identification of genetic modifiers that are responsible for phenotypic variability in affected patients. These genetic modifiers have been postulated to explain key differences in disease phenotypes, including age of loss of ambulation, steroid responsiveness, and the presence or absence of cardiac defects in patients with the same form of muscular dystrophy. This review highlights recent findings on genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies based on animal and clinical studies. These genetic modifiers hold great promise to be developed into novel therapeutic targets for the treatment of muscular dystrophies. Muscle Nerve 57: 6-15, 2018.
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Affiliation(s)
- Rylie M. Hightower
- University of Alabama at Birmingham Graduate School of Biomedical Sciences, Birmingham, AL 35294
| | - Matthew S. Alexander
- Department of Pediatrics, Division of Neurology at Children’s of Alabama and the University of Alabama at Birmingham, Birmingham, AL, 35294
- Department of Genetics, the University of Alabama at Birmingham, Birmingham, AL, 35294
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10
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Immortalized Muscle Cell Model to Test the Exon Skipping Efficacy for Duchenne Muscular Dystrophy. J Pers Med 2017; 7:jpm7040013. [PMID: 29035327 PMCID: PMC5748625 DOI: 10.3390/jpm7040013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/08/2017] [Accepted: 10/08/2017] [Indexed: 01/25/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal genetic disorder that most commonly results from mutations disrupting the reading frame of the dystrophin (DMD) gene. Among the therapeutic approaches employed, exon skipping using antisense oligonucleotides (AOs) is one of the most promising strategies. This strategy aims to restore the reading frame, thus producing a truncated, yet functioning dystrophin protein. In 2016, the Food and Drug Administration (FDA) conditionally approved the first AO-based drug, eteplirsen (Exondys 51), developed for DMD exon 51 skipping. An accurate and reproducible method to quantify exon skipping efficacy is essential for evaluating the therapeutic potential of different AOs sequences. However, previous in vitro screening studies have been hampered by the limited proliferative capacity and insufficient amounts of dystrophin expressed by primary muscle cell lines that have been the main system used to evaluate AOs sequences. In this paper, we illustrate the challenges associated with primary muscle cell lines and describe a novel approach that utilizes immortalized cell lines to quantitatively evaluate the exon skipping efficacy in in vitro studies.
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11
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Natural disease history of mouse models for limb girdle muscular dystrophy types 2D and 2F. PLoS One 2017; 12:e0182704. [PMID: 28797108 PMCID: PMC5552258 DOI: 10.1371/journal.pone.0182704] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/24/2017] [Indexed: 12/22/2022] Open
Abstract
Limb-girdle muscular dystrophy types 2D and 2F (LGMD 2D and 2F) are autosomal recessive disorders caused by mutations in the alpha- and delta sarcoglycan genes, respectively, leading to severe muscle weakness and degeneration. The cause of the disease has been well characterized and a number of animal models are available for pre-clinical studies to test potential therapeutic interventions. To facilitate transition from drug discovery to clinical trials, standardized procedures and natural disease history data were collected for these mouse models. Implementing the TREAD-NMD standardized operating procedures, we here subjected LGMD2D (SGCA-null), LGMD2F (SGCD-null) and wild type (C57BL/6J) mice to five functional tests from the age of 4 to 32 weeks. To assess whether the functional test regime interfered with disease pathology, sedentary groups were taken along. Muscle physiology testing of tibialis anterior muscle was performed at the age of 34 weeks. Muscle histopathology and gene expression was analysed in skeletal muscles and heart. Muscle histopathology and gene expression was analysed in skeletal muscles and heart. Mice successfully accomplished the functional tests, which did not interfere with disease pathology. Muscle function of SGCA- and SGCD-null mice was impaired and declined over time. Interestingly, female SGCD-null mice outperformed males in the two and four limb hanging tests, which proved the most suitable non-invasive tests to assess muscle function. Muscle physiology testing of tibialis anterior muscle revealed lower specific force and higher susceptibility to eccentric-induced damage in LGMD mice. Analyzing muscle histopathology and gene expression, we identified the diaphragm as the most affected muscle in LGMD strains. Cardiac fibrosis was found in SGCD-null mice, being more severe in males than in females. Our study offers a comprehensive natural history dataset which will be useful to design standardized tests and future pre-clinical studies in LGMD2D and 2F mice.
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12
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Abstract
Cardiac and skeletal striated muscles are intricately designed machines responsible for muscle contraction. Coordination of the basic contractile unit, the sarcomere, and the complex cytoskeletal networks are critical for contractile activity. The sarcomere is comprised of precisely organized individual filament systems that include thin (actin), thick (myosin), titin, and nebulin. Connecting the sarcomere to other organelles (e.g., mitochondria and nucleus) and serving as the scaffold to maintain cellular integrity are the intermediate filaments. The costamere, on the other hand, tethers the sarcomere to the cell membrane. Unique structures like the intercalated disc in cardiac muscle and the myotendinous junction in skeletal muscle help synchronize and transmit force. Intense investigation has been done on many of the proteins that make up these cytoskeletal assemblies. Yet the details of their function and how they interconnect have just started to be elucidated. A vast number of human myopathies are contributed to mutations in muscle proteins; thus understanding their basic function provides a mechanistic understanding of muscle disorders. In this review, we highlight the components of striated muscle with respect to their interactions, signaling pathways, functions, and connections to disease. © 2017 American Physiological Society. Compr Physiol 7:891-944, 2017.
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Affiliation(s)
- Christine A Henderson
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Christopher G Gomez
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Stefanie M Novak
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Lei Mi-Mi
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
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13
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Terry RL, Wells DJ. Histopathological Evaluation of Skeletal Muscle with Specific Reference to Mouse Models of Muscular Dystrophy. ACTA ACUST UNITED AC 2016; 6:343-363. [PMID: 27906462 DOI: 10.1002/cpmo.19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The muscular dystrophies are a diverse group of degenerative diseases for which many mouse models are available. These models are frequently used to assess potential therapeutic interventions and histological evaluation of multiple muscles is an important part of this assessment. Histological evaluation is especially useful when combined with tests of muscle function. This unit describes a protocol for necropsy, processing, cryosectioning, and histopathological evaluation of murine skeletal muscles, which is applicable to both models of muscular dystrophy and other neuromuscular conditions. Key histopathological features of dystrophic muscle are discussed using the mdx mouse (a model of Duchenne muscular dystrophy) as an example. Optimal handling during dissection, processing and sectioning is vital to avoid artifacts that can confound or prevent future analyses. Muscles carefully processed using this protocol are suitable for further evaluation using immunohistochemistry, immunofluorescence, special histochemical stains, and immuoblotting. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Rebecca L Terry
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | - Dominic J Wells
- Neuromuscular Group, Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
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14
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Randazzo D, Blaauw B, Paolini C, Pierantozzi E, Spinozzi S, Lange S, Chen J, Protasi F, Reggiani C, Sorrentino V. Exercise-induced alterations and loss of sarcomeric M-line organization in the diaphragm muscle of obscurin knockout mice. Am J Physiol Cell Physiol 2016; 312:C16-C28. [PMID: 27784675 DOI: 10.1152/ajpcell.00098.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/25/2016] [Indexed: 11/22/2022]
Abstract
We recently reported that skeletal muscle fibers of obscurin knockout (KO) mice present altered distribution of ankyrin B (ankB), disorganization of the subsarcolemmal microtubules, and reduced localization of dystrophin at costameres. In addition, these mice have impaired running endurance and increased exercise-induced sarcolemmal damage compared with wild-type animals. Here, we report results from a combined approach of physiological, morphological, and structural studies in which we further characterize the skeletal muscles of obscurin KO mice. A detailed examination of exercise performance, using different running protocols, revealed that the reduced endurance of obscurin KO animals on the treadmill depends on exercise intensity and age. Indeed, a mild running protocol did not evidence significant differences between control and obscurin KO mice, whereas comparison of running abilities of 2-, 6-, and 11-mo-old mice exercised at exhaustion revealed a progressive age-dependent reduction of the exercise tolerance in KO mice. Histological analysis indicated that heavy exercise induced leukocyte infiltration, fibrotic connective tissue deposition, and hypercontractures in the diaphragm of KO mice. On the same line, electron microscopy revealed that, in the diaphragm of exercised obscurin KO mice, but not in the hindlimb muscles, both M-line and H-zone of sarcomeres appeared wavy and less defined. Altogether, these results suggest that obscurin is required for the maintenance of morphological and ultrastructural integrity of skeletal muscle fibers against damage induced by intense mechanical stress and point to the diaphragm as the skeletal muscle most severely affected in obscurin-deficient mice.
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Affiliation(s)
- D Randazzo
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - B Blaauw
- Venetian Institute of Molecular Medicine, Padua, Italy.,Interuniversity Institute of Myology
| | - C Paolini
- Center for Research on Ageing and Translational Medicine & Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti, Chieti, Italy.,Interuniversity Institute of Myology
| | - E Pierantozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - S Spinozzi
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - S Lange
- University of California, San Diego School of Medicine, San Diego, California
| | - J Chen
- University of California, San Diego School of Medicine, San Diego, California
| | - F Protasi
- Center for Research on Ageing and Translational Medicine & Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti, Chieti, Italy.,Interuniversity Institute of Myology
| | - C Reggiani
- Department of Biomedical Sciences, University of Padua, Padua, Italy; and.,Interuniversity Institute of Myology
| | - V Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy; .,Interuniversity Institute of Myology
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Current Progress in Therapeutic Gene Editing for Monogenic Diseases. Mol Ther 2016; 24:465-74. [PMID: 26765770 DOI: 10.1038/mt.2016.5] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/29/2015] [Indexed: 02/06/2023] Open
Abstract
Programmable nucleases allow defined alterations in the genome with ease-of-use, efficiency, and specificity. Their availability has led to accurate and widespread genome engineering, with multiple applications in basic research, biotechnology, and therapy. With regard to human gene therapy, nuclease-based gene editing has facilitated development of a broad range of therapeutic strategies based on both nonhomologous end joining and homology-dependent repair. This review discusses current progress in nuclease-based therapeutic applications for a subset of inherited monogenic diseases including cystic fibrosis, Duchenne muscular dystrophy, diseases of the bone marrow, and hemophilia and highlights associated challenges and future prospects.
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Nicolson GL, de Mattos GF, Settineri R, Costa C, Ellithorpe R, Rosenblatt S, La Valle J, Jimenez A, Ohta S. Clinical Effects of Hydrogen Administration: From Animal and Human Diseases to Exercise Medicine. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ijcm.2016.71005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Meng J, Bencze M, Asfahani R, Muntoni F, Morgan JE. The effect of the muscle environment on the regenerative capacity of human skeletal muscle stem cells. Skelet Muscle 2015; 5:11. [PMID: 25949786 PMCID: PMC4422426 DOI: 10.1186/s13395-015-0036-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/12/2015] [Indexed: 12/31/2022] Open
Abstract
Background Muscle stem cell transplantation is a possible treatment for muscular dystrophy. In addition to the intrinsic properties of the stem cells, the local and systemic environment plays an important role in determining the fate of the grafted cells. We therefore investigated the effect of modulating the host muscle environment in different ways (irradiation or cryoinjury or a combination of irradiation and cryoinjury) in two immunodeficient mouse strains (mdx nude and recombinase-activating gene (Rag)2-/γ chain-/C5-) on the regenerative capacity of two types of human skeletal muscle-derived stem cell (pericytes and CD133+ cells). Methods Human skeletal muscle-derived pericytes or CD133+ cells were transplanted into muscles of either mdx nude or recombinase-activating gene (Rag)2-/γ chain-/C5- host mice. Host muscles were modulated prior to donor cell transplantation by either irradiation, or cryoinjury, or a combination of irradiation and cryoinjury. Muscles were analysed four weeks after transplantation, by staining transverse cryostat sections of grafted muscles with antibodies to human lamin A/C, human spectrin, laminin and Pax 7. The number of nuclei and muscle fibres of donor origin and the number of satellite cells of both host and donor origin were quantified. Results Within both host strains transplanted intra-muscularly with both donor cell types, there were significantly more nuclei and muscle fibres of donor origin in host muscles that had been modulated by cryoinjury, or irradiation+cryoinjury, than by irradiation alone. Irradiation has no additive effects in further enhancing the transplantation efficiency than cryodamage. Donor pericytes did not give rise to satellite cells. However, using CD133+ cells as donor cells, there were significantly more nuclei, muscle fibres, as well as satellite cells of donor origin in Rag2-/γ chain-/C5- mice than mdx nude mice, when the muscles were injured by either cryodamage or irradiation+cryodamage. Conclusions Rag2-/γ chain-/C5- mice are a better recipient mouse strain than mdx nude mice for human muscle stem cell transplantation. Cryodamage of host muscle is the most effective method to enhance the transplantation efficiency of human skeletal muscle stem cells. This study highlights the importance of modulating the muscle environment in preclinical studies to optimise the efficacy of transplanted stem cells. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0036-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jinhong Meng
- The Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Maximilien Bencze
- The Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Rowan Asfahani
- The Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Francesco Muntoni
- The Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Jennifer E Morgan
- The Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
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