1
|
Impaired muscle stem cell function and abnormal myogenesis in acquired myopathies. Biosci Rep 2023; 43:232343. [PMID: 36538023 PMCID: PMC9829652 DOI: 10.1042/bsr20220284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/08/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Skeletal muscle possesses a high plasticity and a remarkable regenerative capacity that relies mainly on muscle stem cells (MuSCs). Molecular and cellular components of the MuSC niche, such as immune cells, play key roles to coordinate MuSC function and to orchestrate muscle regeneration. An abnormal infiltration of immune cells and/or imbalance of pro- and anti-inflammatory cytokines could lead to MuSC dysfunctions that could have long lasting effects on muscle function. Different genetic variants were shown to cause muscular dystrophies that intrinsically compromise MuSC function and/or disturb their microenvironment leading to impaired muscle regeneration that contributes to disease progression. Alternatively, many acquired myopathies caused by comorbidities (e.g., cardiopulmonary or kidney diseases), chronic inflammation/infection, or side effects of different drugs can also perturb MuSC function and their microenvironment. The goal of this review is to comprehensively summarize the current knowledge on acquired myopathies and their impact on MuSC function. We further describe potential therapeutic strategies to restore MuSC regenerative capacity.
Collapse
|
2
|
Ripolone M, Velardo D, Mondello S, Zanotti S, Magri F, Minuti E, Cazzaniga S, Fortunato F, Ciscato P, Tiberio F, Sciacco M, Moggio M, Bettica P, Comi GP. Muscle histological changes in a large cohort of patients affected with Becker muscular dystrophy. Acta Neuropathol Commun 2022; 10:48. [PMID: 35395784 PMCID: PMC8994373 DOI: 10.1186/s40478-022-01354-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/25/2022] [Indexed: 11/17/2022] Open
Abstract
Becker muscular dystrophy (BMD) is a severe X-linked muscle disease. Age of onset, clinical variability, speed of progression and affected tissues display wide variability, making a clinical trial design for drug development very complex. The histopathological changes in skeletal muscle tissue are central to the pathogenesis, but they have not been thoroughly elucidated yet. Here we analysed muscle biopsies from a large cohort of BMD patients, focusing our attention on the histopathological muscle parameters, as fibrosis, fatty replacement, fibre cross sectional area, necrosis, regenerating fibres, splitting fibres, internalized nuclei and dystrophy evaluation. We correlated histological parameters with both demographic features and clinical functional evaluations. The most interesting results of our study are the accurate quantification of fibroadipose tissue replacement and the identification of some histopathological aspects that well correlate with clinical performances. Through correlation analysis, we divided our patients into three clusters with well-defined histological and clinical features. In conclusion, this is the first study that analyses in detail the histological characteristics of muscle biopsies in a large cohort of BMD patients, correlating them to a functional impairment. The collection of these data help to better understand the histopathological progression of the disease and can be useful to validate any pharmacological trial in which the modification of muscle biopsy is utilized as outcome measure.
Collapse
|
3
|
Dort J, Orfi Z, Fabre P, Molina T, Conte TC, Greffard K, Pellerito O, Bilodeau JF, Dumont NA. Resolvin-D2 targets myogenic cells and improves muscle regeneration in Duchenne muscular dystrophy. Nat Commun 2021; 12:6264. [PMID: 34716330 PMCID: PMC8556273 DOI: 10.1038/s41467-021-26516-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/29/2021] [Indexed: 12/24/2022] Open
Abstract
Lack of dystrophin causes muscle degeneration, which is exacerbated by chronic inflammation and reduced regenerative capacity of muscle stem cells in Duchenne Muscular Dystrophy (DMD). To date, glucocorticoids remain the gold standard for the treatment of DMD. These drugs are able to slow down the progression of the disease and increase lifespan by dampening the chronic and excessive inflammatory process; however, they also have numerous harmful side effects that hamper their therapeutic potential. Here, we investigated Resolvin-D2 as a new therapeutic alternative having the potential to target multiple key features contributing to the disease progression. Our in vitro findings showed that Resolvin-D2 promotes the switch of macrophages toward their anti-inflammatory phenotype and increases their secretion of pro-myogenic factors. Moreover, Resolvin-D2 directly targets myogenic cells and promotes their differentiation and the expansion of the pool of myogenic progenitor cells leading to increased myogenesis. These effects are ablated when the receptor Gpr18 is knocked-out, knocked-down, or blocked by the pharmacological antagonist O-1918. Using different mouse models of DMD, we showed that Resolvin-D2 targets both inflammation and myogenesis leading to enhanced muscle function compared to glucocorticoids. Overall, this preclinical study has identified a new therapeutic approach that is more potent than the gold-standard treatment for DMD.
Collapse
Affiliation(s)
- Junio Dort
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Zakaria Orfi
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Paul Fabre
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Thomas Molina
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Talita C Conte
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Karine Greffard
- Endocrinology and Nephrology Unit, CHU de Québec-Laval University Research Center, Quebec city, QC, Canada
| | | | - Jean-François Bilodeau
- Endocrinology and Nephrology Unit, CHU de Québec-Laval University Research Center, Quebec city, QC, Canada
- Department of Medicine, Faculty of Medicine, Laval University, Quebec city, QC, Canada
| | - Nicolas A Dumont
- CHU Sainte-Justine Research Center, Montreal, QC, Canada.
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
| |
Collapse
|
4
|
Germinario E, Bondì M, Blaauw B, Betto R, Danieli-Betto D. Reduction of circulating sphingosine-1-phosphate worsens mdx soleus muscle dystrophic phenotype. Exp Physiol 2020; 105:1895-1906. [PMID: 32897592 DOI: 10.1113/ep088603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the central question of the study? What are the consequences of reducing circulating sphingosine-1-phosphate (S1P) for muscle physiology in the murine model of Duchenne muscular dystrophy (DMD)? What is the main result and its importance? Reduction of the circulating S1P level in mdx mice aggravates the dystrophic phenotype, as seen by an increase in fibre atrophy, fibrosis and loss of specific force, suggesting that S1P signalling is a potential therapeutic target in DMD. Although further studies are needed, plasma S1P levels have the intriguing possibility of being used as a biomarker for disease severity, an important issue in DMD. ABSTRACT Sphingosine-1-phosphate (S1P) is an important regulator of skeletal muscle properties. The dystrophin-deficient mdx mouse possesses low levels of S1P (∼50%) compared with wild type. Increased S1P availability was demonstrated to ameliorate the dystrophic phenotype in Drosophila and in mdx mice. Here, we analysed the effects produced by further reduction of S1P availability on the mass, force and regenerative capacity of dystrophic mdx soleus. Circulating S1P was neutralized by a specific anti-S1P antibody (S1P-Ab) known to lower the extracellular concentration of this signalling lipid. The S1P-Ab was administered intraperitoneally in adult mdx mice every 2 days for the duration of experiments. Soleus muscle properties were analysed 7 or 14 days after the first injection. The decreased availability of circulating S1P after the 14 day treatment reduced mdx soleus fibre cross-sectional area (-16%, P < 0.05), an effect that was associated with an increase in markers of proteolytic (MuRF1 and atrogin-1) and autophagic (p62 and LC3-II/LC3-I ratio) pathways. Moreover, an increase of fibrosis was also observed (+26%, P < 0.05). Notably, the treatment also caused a reduction of specific tetanic tension (-29%, P < 0.05). The mdx soleus regenerative capacity was only slightly influenced by reduced S1P. In conclusion, neutralization of circulating S1P reduces the mass and specific force and increases fibrosis of mdx soleus muscle, thus worsening the dystrophic phenotype. The results confirm that active, functional S1P signalling might counteract the progression of soleus mdx pathology and validate the pathway as a potential therapeutic target for muscular dystrophies.
Collapse
Affiliation(s)
- Elena Germinario
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Interuniversity Institute of Myology, Italy
| | - Michela Bondì
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Interuniversity Institute of Myology, Italy
| | - Romeo Betto
- Interuniversity Institute of Myology, Italy.,CNR-Institute for Neuroscience, CNR, Padova, Italy
| | - Daniela Danieli-Betto
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Interuniversity Institute of Myology, Italy
| |
Collapse
|
5
|
Meng J, Sweeney NP, Doreste B, Muntoni F, McClure M, Morgan J. Restoration of Functional Full-Length Dystrophin After Intramuscular Transplantation of Foamy Virus-Transduced Myoblasts. Hum Gene Ther 2020; 31:241-252. [PMID: 31801386 PMCID: PMC7047098 DOI: 10.1089/hum.2019.224] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/24/2019] [Indexed: 12/12/2022] Open
Abstract
Stem cell therapy is a promising strategy to treat muscle diseases such as Duchenne muscular dystrophy (DMD). To avoid immune rejection of donor cells or donor-derived muscle, autologous cells, which have been genetically modified to express dystrophin, are preferable to cells derived from healthy donors. Restoration of full-length dystrophin (FL-dys) using viral vectors is extremely challenging, due to the limited packaging capacity of the vectors, but we have recently shown that either a foamy viral or lentiviral vector is able to package FL-dys open-reading frame and transduce myoblasts derived from a DMD patient. Differentiated myotubes derived from these transduced cells produced FL-dys. Here, we transplanted the foamy viral dystrophin-corrected DMD myoblasts intramuscularly into mdx nude mice, and showed that the transduced cells contributed to muscle regeneration, expressing FL-dys in nearly all the muscle fibers of donor origin. Furthermore, we showed that the restored FL-dys recruited members of the dystrophin-associated protein complex and neuronal nitric oxide synthase within donor-derived muscle fibers, evidence that the restored dystrophin protein is functional. Dystrophin-expressing donor-derived muscle fibers expressed lower levels of utrophin than host muscle fibers, providing additional evidence of functional improvement of donor-derived myofibers. This is the first in vivo evidence that foamy virus vector-transduced DMD myoblasts can contribute to muscle regeneration and mediate functional dystrophin restoration following their intramuscular transplantation, representing a promising therapeutic strategy for individual small muscles in DMD.
Collapse
Affiliation(s)
- Jinhong Meng
- Developmental Neuroscience Programme, Molecular Neurosciences Section, Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, United Kingdom
| | - Nathan Paul Sweeney
- Jefferiss Research Trust Laboratories, Imperial College London, London, United Kingdom
| | - Bruno Doreste
- Developmental Neuroscience Programme, Molecular Neurosciences Section, Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, United Kingdom
| | - Francesco Muntoni
- Developmental Neuroscience Programme, Molecular Neurosciences Section, Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, United Kingdom
| | - Myra McClure
- Jefferiss Research Trust Laboratories, Imperial College London, London, United Kingdom
| | - Jennifer Morgan
- Developmental Neuroscience Programme, Molecular Neurosciences Section, Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- National Institute for Health Research, Great Ormond Street Institute of Child Health Biomedical Research Centre, University College London, London, United Kingdom
| |
Collapse
|
6
|
Fiore PF, Benedetti A, Sandonà M, Madaro L, De Bardi M, Saccone V, Puri PL, Gargioli C, Lozanoska-Ochser B, Bouché M. Lack of PKCθ Promotes Regenerative Ability of Muscle Stem Cells in Chronic Muscle Injury. Int J Mol Sci 2020; 21:ijms21030932. [PMID: 32023816 PMCID: PMC7037041 DOI: 10.3390/ijms21030932] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/24/2020] [Accepted: 01/29/2020] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disease characterized by muscle wasting and chronic inflammation, leading to impaired satellite cells (SCs) function and exhaustion of their regenerative capacity. We previously showed that lack of PKCθ in mdx mice, a mouse model of DMD, reduces muscle wasting and inflammation, and improves muscle regeneration and performance at early stages of the disease. In this study, we show that muscle regeneration is boosted, and fibrosis reduced in mdxθ−/− mice, even at advanced stages of the disease. This phenotype was associated with a higher number of Pax7 positive cells in mdxθ−/− muscle compared with mdx muscle, during the progression of the disease. Moreover, the expression level of Pax7 and Notch1, the pivotal regulators of SCs self-renewal, were upregulated in SCs isolated from mdxθ−/− muscle compared with mdx derived SCs. Likewise, the expression of the Notch ligands Delta1 and Jagged1 was higher in mdxθ−/− muscle compared with mdx. The expression level of Delta1 and Jagged1 was also higher in PKCθ−/− muscle compared with WT muscle following acute injury. In addition, lack of PKCθ prolonged the survival and sustained the differentiation of transplanted myogenic progenitors. Overall, our results suggest that lack of PKCθ promotes muscle repair in dystrophic mice, supporting stem cells survival and maintenance through increased Delta-Notch signaling.
Collapse
MESH Headings
- Animals
- Cardiotoxins/adverse effects
- Cell Differentiation
- Cells, Cultured
- Male
- Mice
- Mice, Inbred mdx
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/injuries
- Muscle, Skeletal/physiology
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/therapy
- PAX7 Transcription Factor/metabolism
- Protein Kinase C-theta/genetics
- Receptor, Notch1/metabolism
- Regeneration
- Signal Transduction
- Stem Cell Transplantation
- Stem Cells/cytology
- Stem Cells/drug effects
- Stem Cells/metabolism
Collapse
Affiliation(s)
- Piera Filomena Fiore
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
| | - Anna Benedetti
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
| | - Martina Sandonà
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
- IRCCS Fondazione Santa Lucia (FSL), e00143 Rome, Italy; (M.D.B.); (V.S.)
| | - Luca Madaro
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
- IRCCS Fondazione Santa Lucia (FSL), e00143 Rome, Italy; (M.D.B.); (V.S.)
| | - Marco De Bardi
- IRCCS Fondazione Santa Lucia (FSL), e00143 Rome, Italy; (M.D.B.); (V.S.)
| | - Valentina Saccone
- IRCCS Fondazione Santa Lucia (FSL), e00143 Rome, Italy; (M.D.B.); (V.S.)
- Department of Life Sciences and Public Health, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Pier Lorenzo Puri
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA;
| | - Cesare Gargioli
- Department of Biology, Tor Vergata University, 00133 Rome, Italy;
| | - Biliana Lozanoska-Ochser
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
| | - Marina Bouché
- Department of AHFMO, University of Rome “la Sapienza”, Via A. Scarpa 14, 00161 Rome, Italy; (P.F.F.); (A.B.); (M.S.); (L.M.); (B.L.-O.)
- Correspondence: ; Tel.: +39-06-4976-6755
| |
Collapse
|
7
|
Wang YX, Feige P, Brun CE, Hekmatnejad B, Dumont NA, Renaud JM, Faulkes S, Guindon DE, Rudnicki MA. EGFR-Aurka Signaling Rescues Polarity and Regeneration Defects in Dystrophin-Deficient Muscle Stem Cells by Increasing Asymmetric Divisions. Cell Stem Cell 2019; 24:419-432.e6. [PMID: 30713094 DOI: 10.1016/j.stem.2019.01.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/20/2018] [Accepted: 01/07/2019] [Indexed: 12/17/2022]
Abstract
Loss of dystrophin expression in Duchenne muscular dystrophy (DMD) causes progressive degeneration of skeletal muscle, which is exacerbated by reduced self-renewing asymmetric divisions of muscle satellite cells. This, in turn, affects the production of myogenic precursors and impairs regeneration and suggests that increasing such divisions may be beneficial. Here, through a small-molecule screen, we identified epidermal growth factor receptor (EGFR) and Aurora kinase A (Aurka) as regulators of asymmetric satellite cell divisions. Inhibiting EGFR causes a substantial shift from asymmetric to symmetric division modes, whereas EGF treatment increases asymmetric divisions. EGFR activation acts through Aurka to orient mitotic centrosomes, and inhibiting Aurka blocks EGF stimulation-induced asymmetric division. In vivo EGF treatment markedly activates asymmetric divisions of dystrophin-deficient satellite cells in mdx mice, increasing progenitor numbers, enhancing regeneration, and restoring muscle strength. Therefore, activating an EGFR-dependent polarity pathway promotes functional rescue of dystrophin-deficient satellite cells and enhances muscle force generation.
Collapse
Affiliation(s)
- Yu Xin Wang
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Peter Feige
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Caroline E Brun
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bahareh Hekmatnejad
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Nicolas A Dumont
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Sharlene Faulkes
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Daniel E Guindon
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Michael A Rudnicki
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; Department of Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
| |
Collapse
|
8
|
Dumont NA, Rudnicki MA. Targeting muscle stem cell intrinsic defects to treat Duchenne muscular dystrophy. NPJ Regen Med 2016; 1. [PMID: 29188075 PMCID: PMC5703417 DOI: 10.1038/npjregenmed.2016.6] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disease characterised by skeletal muscle degeneration and progressive muscle wasting, which is caused by loss-of-function mutations in the DMD gene that encodes for the protein dystrophin. Dystrophin has critical roles in myofiber stability and integrity by connecting the actin cytoskeleton to the extracellular matrix. Absence of dystrophin leads to myofiber fragility and contributes to skeletal muscle degeneration in DMD patients, however, accumulating evidence also indicate that muscle stem cells (also known as satellite cells) are defective in dystrophic muscles, which leads to impaired muscle regeneration. Our recent work demonstrated that dystrophin is expressed in activated satellite cells, where it regulates the establishment of satellite cell polarity and asymmetric cell division. These findings indicate that dystrophin-deficient satellite cells have intrinsic dysfunctions that contribute to muscle wasting and progression of the disease. This discovery suggests that satellite cells could be targeted to treat DMD. Here we discuss how these new findings affect regenerative therapies for muscular dystrophies. Therapies targeting satellite cells hold great potential and could have long-term efficiency owing to the high self-renewal ability of these cells.
Collapse
Affiliation(s)
- Nicolas A Dumont
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Michael A Rudnicki
- Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
9
|
Dumont NA, Wang YX, von Maltzahn J, Pasut A, Bentzinger CF, Brun CE, Rudnicki MA. Dystrophin expression in muscle stem cells regulates their polarity and asymmetric division. Nat Med 2015; 21:1455-63. [PMID: 26569381 PMCID: PMC4839960 DOI: 10.1038/nm.3990] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 10/13/2015] [Indexed: 12/12/2022]
Abstract
Dystrophin is expressed in differentiated myofibers, in which it is required for sarcolemmal integrity, and loss-of-function mutations in the gene that encodes it result in Duchenne muscular dystrophy (DMD), a disease characterized by progressive and severe skeletal muscle degeneration. Here we found that dystrophin is also highly expressed in activated muscle stem cells (also known as satellite cells), in which it associates with the serine-threonine kinase Mark2 (also known as Par1b), an important regulator of cell polarity. In the absence of dystrophin, expression of Mark2 protein is downregulated, resulting in the inability to localize the cell polarity regulator Pard3 to the opposite side of the cell. Consequently, the number of asymmetric divisions is strikingly reduced in dystrophin-deficient satellite cells, which also display a loss of polarity, abnormal division patterns (including centrosome amplification), impaired mitotic spindle orientation and prolonged cell divisions. Altogether, these intrinsic defects strongly reduce the generation of myogenic progenitors that are needed for proper muscle regeneration. Therefore, we conclude that dystrophin has an essential role in the regulation of satellite cell polarity and asymmetric division. Our findings indicate that muscle wasting in DMD not only is caused by myofiber fragility, but also is exacerbated by impaired regeneration owing to intrinsic satellite cell dysfunction.
Collapse
Affiliation(s)
- Nicolas A. Dumont
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Yu Xin Wang
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Julia von Maltzahn
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Alessandra Pasut
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - C. Florian Bentzinger
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Caroline E. Brun
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Michael A. Rudnicki
- Sprott Center For Stem Cell Research, Ottawa Hospital Research Institute, Regenerative Medicine Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
10
|
Hollinger K, Selsby JT. PGC-1αgene transfer improves muscle function in dystrophic muscle following prolonged disease progress. Exp Physiol 2015; 100:1145-58. [DOI: 10.1113/ep085339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/31/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Katrin Hollinger
- Department of Animal Science; Iowa State University; Ames IA 50011 USA
| | - Joshua T. Selsby
- Department of Animal Science; Iowa State University; Ames IA 50011 USA
| |
Collapse
|
11
|
Bobadilla M, Sáinz N, Rodriguez JA, Abizanda G, Orbe J, de Martino A, García Verdugo JM, Páramo JA, Prósper F, Pérez-Ruiz A. MMP-10 is required for efficient muscle regeneration in mouse models of injury and muscular dystrophy. Stem Cells 2014; 32:447-61. [PMID: 24123596 DOI: 10.1002/stem.1553] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/20/2013] [Accepted: 08/23/2013] [Indexed: 12/17/2022]
Abstract
Matrix metalloproteinases (MMPs), a family of endopeptidases that are involved in the degradation of extracellular matrix components, have been implicated in skeletal muscle regeneration. Among the MMPs, MMP-2 and MMP-9 are upregulated in Duchenne muscular dystrophy (DMD), a fatal X-linked muscle disorder. However, inhibition or overexpression of specific MMPs in a mouse model of DMD (mdx) has yielded mixed results regarding disease progression, depending on the MMP studied. Here, we have examined the role of MMP-10 in muscle regeneration during injury and muscular dystrophy. We found that skeletal muscle increases MMP-10 protein expression in response to damage (notexin) or disease (mdx mice), suggesting its role in muscle regeneration. In addition, we found that MMP-10-deficient muscles displayed impaired recruitment of endothelial cells, reduced levels of extracellular matrix proteins, diminished collagen deposition, and decreased fiber size, which collectively contributed to delayed muscle regeneration after injury. Also, MMP-10 knockout in mdx mice led to a deteriorated dystrophic phenotype. Moreover, MMP-10 mRNA silencing in injured muscles (wild-type and mdx) reduced muscle regeneration, while addition of recombinant human MMP-10 accelerated muscle repair, suggesting that MMP-10 is required for efficient muscle regeneration. Furthermore, our data suggest that MMP-10-mediated muscle repair is associated with VEGF/Akt signaling. Thus, our findings indicate that MMP-10 is critical for skeletal muscle maintenance and regeneration during injury and disease.
Collapse
Affiliation(s)
- Míriam Bobadilla
- Cell Therapy Area, Division of Cancer, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Matrix metalloproteinase-9 inhibition improves proliferation and engraftment of myogenic cells in dystrophic muscle of mdx mice. PLoS One 2013; 8:e72121. [PMID: 23977226 PMCID: PMC3744489 DOI: 10.1371/journal.pone.0072121] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/09/2013] [Indexed: 11/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) caused by loss of cytoskeletal protein dystrophin is a devastating disorder of skeletal muscle. Primary deficiency of dystrophin leads to several secondary pathological changes including fiber degeneration and regeneration, extracellular matrix breakdown, inflammation, and fibrosis. Matrix metalloproteinases (MMPs) are a group of extracellular proteases that are involved in tissue remodeling, inflammation, and development of interstitial fibrosis in many disease states. We have recently reported that the inhibition of MMP-9 improves myopathy and augments myofiber regeneration in mdx mice (a mouse model of DMD). However, the mechanisms by which MMP-9 regulates disease progression in mdx mice remain less understood. In this report, we demonstrate that the inhibition of MMP-9 augments the proliferation of satellite cells in dystrophic muscle. MMP-9 inhibition also causes significant reduction in percentage of M1 macrophages with concomitant increase in the proportion of promyogenic M2 macrophages in mdx mice. Moreover, inhibition of MMP-9 increases the expression of Notch ligands and receptors, and Notch target genes in skeletal muscle of mdx mice. Furthermore, our results show that while MMP-9 inhibition augments the expression of components of canonical Wnt signaling, it reduces the expression of genes whose products are involved in activation of non-canonical Wnt signaling in mdx mice. Finally, the inhibition of MMP-9 was found to dramatically improve the engraftment of transplanted myoblasts in skeletal muscle of mdx mice. Collectively, our study suggests that the inhibition of MMP-9 is a promising approach to stimulate myofiber regeneration and improving engraftment of muscle progenitor cells in dystrophic muscle.
Collapse
|
13
|
Profiling of age-related changes in the tibialis anterior muscle proteome of the mdx mouse model of dystrophinopathy. J Biomed Biotechnol 2012; 2012:691641. [PMID: 23093855 PMCID: PMC3471022 DOI: 10.1155/2012/691641] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/13/2012] [Indexed: 12/22/2022] Open
Abstract
X-linked muscular dystrophy is a highly progressive disease of childhood and characterized by primary genetic abnormalities in the dystrophin gene. Senescent mdx specimens were used for a large-scale survey of potential age-related alterations in the dystrophic phenotype, because the established mdx animal model of dystrophinopathy exhibits progressive deterioration of muscle tissue with age. Since the mdx tibialis anterior muscle is a frequently used model system in muscular dystrophy research, we employed this particular muscle to determine global changes in the dystrophic skeletal muscle proteome. The comparison of mdx mice aged 8 weeks versus 22 months by mass-spectrometry-based proteomics revealed altered expression levels in 8 distinct protein species. Increased levels were shown for carbonic anhydrase, aldolase, and electron transferring flavoprotein, while the expressions of pyruvate kinase, myosin, tropomyosin, and the small heat shock protein Hsp27 were found to be reduced in aged muscle. Immunoblotting confirmed age-dependent changes in the density of key muscle proteins in mdx muscle. Thus, segmental necrosis in mdx tibialis anterior muscle appears to trigger age-related protein perturbations due to dystrophin deficiency. The identification of novel indicators of progressive muscular dystrophy might be useful for the establishment of a muscle subtype-specific biomarker signature of dystrophinopathy.
Collapse
|
14
|
Carberry S, Zweyer M, Swandulla D, Ohlendieck K. Proteomics reveals drastic increase of extracellular matrix proteins collagen and dermatopontin in the aged mdx diaphragm model of Duchenne muscular dystrophy. Int J Mol Med 2012; 30:229-34. [PMID: 22614334 PMCID: PMC3573751 DOI: 10.3892/ijmm.2012.1006] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 04/11/2012] [Indexed: 01/15/2023] Open
Abstract
Duchenne muscular dystrophy is a lethal genetic disease of childhood caused by primary abnormalities in the gene coding for the membrane cytoskeletal protein dystrophin. The mdx mouse is an established animal model of various aspects of X-linked muscular dystrophy and is widely used for studying fundamental mechanisms of dystrophinopathy and testing novel therapeutic approaches to treat one of the most frequent gender-specific diseases in humans. In order to determine global changes in the muscle proteome with the progressive deterioration of mdx tissue with age, we have characterized diaphragm muscle from mdx mice at three ages (8-weeks, 12-months and 22-months) using mass spectrometry-based proteomics. Altered expression levels in diaphragm of 8-week vs. 22-month mice were shown to occur in 11 muscle-associated proteins. Aging in the mdx diaphragm seems to be associated with a drastic increase in the extracellular matrix proteins, collagen and dermatopontin, the molecular chaperone αB-crystallin, and the intermediate filament protein vimentin, suggesting increased accumulation of connective tissue, an enhanced cellular stress response and compensatory stabilization of the weakened membrane cytoskeleton. These proteomic findings establish the aged mdx diaphragm as an excellent model system for studying secondary effects of dystrophin deficiency in skeletal muscle tissue.
Collapse
Affiliation(s)
- Steven Carberry
- Department of Biology, National University of Ireland, Maynooth, Kildare, Republic of Ireland
| | | | | | | |
Collapse
|
15
|
Isolation of satellite cells from single muscle fibers from young, aged, or dystrophic muscles. Methods Mol Biol 2012; 916:3-14. [PMID: 22914928 DOI: 10.1007/978-1-61779-980-8_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Skeletal muscle contains an identified resident stem cell population called the satellite cells. This cell is responsible for the majority of the postnatal growth and regenerative potential of skeletal muscle. Other cells do contribute to skeletal muscle regeneration and in cultures of minced whole muscle these cells are cultured along with the satellite cells and it is impossible to dissect out their contribution compared to the satellite cells. Therefore, a method to culture pure satellite cells has been developed to study the signaling pathways that control their proliferation and differentiation. In our studies into the role of the resident myogenic stem cells in regeneration, myopathic conditions, and aging, we have optimized the established techniques that already exist to isolate pure satellite cell cultures from single muscle fibers. We have successfully isolated satellite cells from young adults through to 24-month-old muscles and obtained populations of cells that we are studying for the signaling events that regulate their proliferative potential.
Collapse
|
16
|
Robson LG, Di Foggia V, Radunovic A, Bird K, Zhang X, Marino S. Bmi1 is expressed in postnatal myogenic satellite cells, controls their maintenance and plays an essential role in repeated muscle regeneration. PLoS One 2011; 6:e27116. [PMID: 22096526 PMCID: PMC3212532 DOI: 10.1371/journal.pone.0027116] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 10/11/2011] [Indexed: 11/25/2022] Open
Abstract
Satellite cells are the resident stem cell population of the adult mammalian skeletal muscle and they play a crucial role in its homeostasis and in its regenerative capacity after injury. We show here that the Polycomb group (PcG) gene Bmi1 is expressed in both the Pax7 positive (+)/Myf5 negative (−) stem cell population as well as the Pax7+/Myf5+ committed myogenic progenitor population. Depletion of Pax7+/Myf5− satellite cells with reciprocal increase in Pax7+/Myf5+ as well as MyoD positive (+) cells is seen in Bmi1−/− mice leading to reduced postnatal muscle fiber size and impaired regeneration upon injury. Bmi1−/− satellite cells have a reduced proliferative capacity and fail to re-enter the cell cycle when stimulated by high serum conditions in vitro, in keeping with a cell intrinsic defect. Thus, both the in vivo and in vitro results suggest that Bmi1 plays a crucial role in the maintenance of the stem cell pool in postnatal skeletal muscle and is essential for efficient muscle regeneration after injury especially after repeated muscle injury.
Collapse
Affiliation(s)
- Lesley G. Robson
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Valentina Di Foggia
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Aleksandar Radunovic
- Neuroscience Clinical Academic Unit, Barts and The London NHS Trust, Whitechapel, London, United Kingdom
| | - Katy Bird
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Xinyu Zhang
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Silvia Marino
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
- * E-mail:
| |
Collapse
|
17
|
Rousseau J, Dumont N, Lebel C, Quenneville SP, Côté CH, Frenette J, Tremblay JP. Dystrophin expression following the transplantation of normal muscle precursor cells protects mdx muscle from contraction-induced damage. Cell Transplant 2010; 19:589-96. [PMID: 20650035 DOI: 10.3727/096368910x4863235] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is the most frequent muscular dystrophy. Currently, there is no cure for the disease. The transplantation of muscle precursor cells (MPCs) is one of the possible treatments, because it can restore the expression of dystrophin in DMD muscles. In this study, we investigated the effects of myoblasts injected with cardiotoxin on the contractile properties and resistance to eccentric contractions of transplanted and nontransplanted muscles. We used the extensor digitorum longus (EDL) as a model for our study. We conclude that the sole presence of dystrophin in a high percentage of muscle fibers is not sufficient by itself to increase the absolute or the specific force in the EDL of transplanted mdx muscle. This lack of strength increase may be due to the extensive damage that was produced by the cardiotoxin, which was coinjected with the myoblasts. However, the dystrophin presence is sufficient to protect muscle from eccentric damage as indicated by the force drop results.
Collapse
Affiliation(s)
- Joel Rousseau
- Centre de recherche de CHUL, CHUQ, Université Laval, Sainte-Foy, Québec, Canada
| | | | | | | | | | | | | |
Collapse
|
18
|
Mouisel E, Vignaud A, Hourdé C, Butler-Browne G, Ferry A. Muscle weakness and atrophy are associated with decreased regenerative capacity and changes in mTOR signaling in skeletal muscles of venerable (18-24-month-old) dystrophic mdx mice. Muscle Nerve 2010; 41:809-18. [PMID: 20151467 DOI: 10.1002/mus.21624] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The muscles of mdx mice progressively deteriorate with age. We wanted to know whether this is associated with a decrease in regenerative capacity and/or changes in the mammalian target of rapamycin complex (mTOR) signaling pathway. Muscles of mdx mice aged 5 weeks, 5, 12, and 18-24 months were studied. Maximal force and muscle weight of the older mice were decreased as compared to younger adult mice. Activation of the mTOR signaling pathway, i.e., phosphorylation of Akt (also known as protein kinase B) and ribosomal protein S6 was also reduced in the older mice. Moreover, 14 days after cardiotoxin injury the degree of recovery of maximal force and muscle weight were less in the older mice. In contrast to younger mice, there was also activation of the mTOR pathway during regeneration in the older mice. Progressive muscle weakness and atrophy in mdx mouse muscle is associated with a decline in regenerative potential and changes in activation of the mTOR signaling pathway.
Collapse
Affiliation(s)
- E Mouisel
- INSERM U974/CNRS UMR 7215, 105 bd de l'Hôpital, 75634 Paris Cedex 13, F-75013 France
| | | | | | | | | |
Collapse
|
19
|
Modulation of caspase activity regulates skeletal muscle regeneration and function in response to vasopressin and tumor necrosis factor. PLoS One 2009; 4:e5570. [PMID: 19440308 PMCID: PMC2680623 DOI: 10.1371/journal.pone.0005570] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Accepted: 04/20/2009] [Indexed: 11/19/2022] Open
Abstract
Muscle homeostasis involves de novo myogenesis, as observed in conditions of acute or chronic muscle damage. Tumor Necrosis Factor (TNF) triggers skeletal muscle wasting in several pathological conditions and inhibits muscle regeneration. We show that intramuscular treatment with the myogenic factor Arg8-vasopressin (AVP) enhanced skeletal muscle regeneration and rescued the inhibitory effects of TNF on muscle regeneration. The functional analysis of regenerating muscle performance following TNF or AVP treatments revealed that these factors exerted opposite effects on muscle function. Principal component analysis showed that TNF and AVP mainly affect muscle tetanic force and fatigue. Importantly, AVP counteracted the effects of TNF on muscle function when delivered in combination with the latter. Muscle regeneration is, at least in part, regulated by caspase activation, and AVP abrogated TNF-dependent caspase activation. The contrasting effects of AVP and TNF in vivo are recapitulated in myogenic cell cultures, which express both PW1, a caspase activator, and Hsp70, a caspase inhibitor. We identified PW1 as a potential Hsp70 partner by screening for proteins interacting with PW1. Hsp70 and PW1 co-immunoprecipitated and co-localized in muscle cells. In vivo Hsp70 protein level was upregulated by AVP, and Hsp70 overexpression counteracted the TNF block of muscle regeneration. Our results show that AVP counteracts the effects of TNF through cross-talk at the Hsp70 level. Therefore, muscle regeneration, both in the absence and in the presence of cytokines may be enhanced by increasing Hsp70 expression.
Collapse
|
20
|
Gayraud-Morel B, Chrétien F, Tajbakhsh S. Skeletal muscle as a paradigm for regenerative biology and medicine. Regen Med 2009; 4:293-319. [PMID: 19317647 DOI: 10.2217/17460751.4.2.293] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tissue development and regeneration share common features, since modules of regulatory pathways and transcription factors that are crucial for prenatal development are redeployed for tissue reconstruction after trauma. Regenerative medicine has therefore gained important insights through the study of developmental and regenerative biology. Moreover, diverse experimental models have been used to investigate the regeneration process in different tissues and organs. Paradoxically, little is known regarding the relative contribution of stem cells with respect to the supporting tissue during tissue regeneration. Particular attention will be given to mouse models using distinct injury paradigms to investigate the regenerative biology of skeletal muscle. An understanding of the response of stem and parenchymal cells is crucial for the development of clinical strategies to combat the normal decline in tissue performance during aging or its reconstitution after trauma and during disease. This review addresses these issues, focusing on muscle regeneration and how different factors, including genes, cells and the environment, impinge on this process.
Collapse
Affiliation(s)
- Barbara Gayraud-Morel
- Stem Cells & Development, Department of Developmental Biology, Pasteur Institute, CNRS URA 2578, 25 rue du Dr. Roux, 75724 Paris Cedex 15, France
| | | | | |
Collapse
|
21
|
Li H, Mittal A, Makonchuk DY, Bhatnagar S, Kumar A. Matrix metalloproteinase-9 inhibition ameliorates pathogenesis and improves skeletal muscle regeneration in muscular dystrophy. Hum Mol Genet 2009; 18:2584-98. [PMID: 19401296 DOI: 10.1093/hmg/ddp191] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal X-linked genetic disorder of skeletal muscle caused by mutation in dystrophin gene. Although the degradation of skeletal muscle extracellular matrix, inflammation and fibrosis are the common pathological features in DMD, the underlying mechanisms remain poorly understood. In this study, we have investigated the role and the mechanisms by which increased levels of matrix metalloproteinase-9 (MMP-9) protein causes myopathy in dystrophin-deficient mdx mice. The levels of MMP-9 but not tissue inhibitor of MMPs were drastically increased in skeletal muscle of mdx mice. Besides skeletal muscle, infiltrating macrophages were found to contribute significantly to the elevated levels of MMP-9 in dystrophic muscle. In vivo administration of a nuclear factor-kappa B inhibitory peptide, NBD, blocked the expression of MMP-9 in dystrophic muscle of mdx mice. Deletion of Mmp9 gene in mdx mice improved skeletal muscle structure and functions and reduced muscle injury, inflammation and fiber necrosis. Inhibition of MMP-9 increased the levels of cytoskeletal protein beta-dystroglycan and neural nitric oxide synthase and reduced the amounts of caveolin-3 and transforming growth factor-beta in myofibers of mdx mice. Genetic ablation of MMP-9 significantly augmented the skeletal muscle regeneration in mdx mice. Finally, pharmacological inhibition of MMP-9 activity also ameliorated skeletal muscle pathogenesis and enhanced myofiber regeneration in mdx mice. Collectively, our study suggests that the increased production of MMP-9 exacerbates dystrophinopathy and MMP-9 represents as one of the most promising therapeutic targets for the prevention of disease progression in DMD.
Collapse
Affiliation(s)
- Hong Li
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | | | | | | | | |
Collapse
|
22
|
Stephan L, Pichavant C, Bouchentouf M, Mills P, Camirand G, Tagmouti S, Rothstein D, Tremblay JP. Induction of tolerance across fully mismatched barriers by a nonmyeloablative treatment excluding antibodies or irradiation use. Cell Transplant 2007; 15:835-46. [PMID: 17269453 DOI: 10.3727/000000006783981521] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A mixed-chimerism approach is a major goal to circumvent sustained immunosuppression, but most of the proposed protocols need antibody treatment or host irradiation. Another promising experience involves busulfan combined with cyclophosphamide treatment. Additionally, recent publications demonstrated that, differing from busulfan, treosulfan administration does not present severe organ or hemato toxicities. Currently, Duchenne muscular dystrophy (DMD) patients are treated with chronic immunosuppression for muscle precursor cell transplantation (MT). We have developed a safe tolerance approach within this cellular allotransplantation therapy background. Thus, we have conditioned, prior to a donor BALB/c MT, the dystrophic mouse model C57Bl10J mdx/mdx, with our treatment based on a donor-specific transfusion, then a treosulfan treatment combined with single cyclophosphamide dose, and finally a donor bone marrow transplantation (TTCB). A first MT was performed in all mixed chimeric mice resulting from the TTCB treatment in the left tibialis anterior (TA) muscles. A second MT from the same donor strain was performed 100 days later in the right TA without any additional therapy. Results show that all treated mice developed permanent mixed chimerism. Long-lasting donor-positive fibers were present in both TAs of the mice, which received MT after the TTCB treatment. Only a basal level of infiltration was observed around donor fibers and mixed chimeric mice rejected third-party haplotype skin grafts. Thus, mixed chimerism development with this TTCB conditioning regimen promotes donor-specific stable tolerance, avoiding costimulatory blockade antibodies or irradiation use and side effects of sustained immunosuppressive treatments. This protocol could be eventually applied for MT to DMD patients or others tissue transplantations.
Collapse
Affiliation(s)
- Lionel Stephan
- Human Genetic, CHUQ-CHUL, Laval University, Ste-Foy, G1V4G2, Canada
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Schäfer R, Knauf U, Zweyer M, Högemeier O, de Guarrini F, Liu X, Eichhorn HJ, Koch FW, Mundegar RR, Erzen I, Wernig A. Age dependence of the human skeletal muscle stem cell in forming muscle tissue. Artif Organs 2006; 30:130-40. [PMID: 16480387 DOI: 10.1111/j.1525-1594.2006.00199.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human skeletal muscle stem cells from healthy donors aged 2-82 years (n = 13) and from three children suffering from Duchenne Muscular Dystrophy (DMD) were implanted into soleus muscles of immunoincompetent mice and were also expanded in vitro until senescence. Growth of implanted cells was quantified by structural features and by the amount of human DNA present in a muscle. Proliferative capacity in vitro and in vivo was inversely related to age of the donor. In vitro, a decline of about two mean population doublings (MPDs) per 10 years of donor's age was observed. Muscle stem cells from DMD children were prematurely aged. In general, cell preparations with low or decreasing content in desmin-positive cells produced more MPDs than age-matched high-desmin preparations and upon implantation more human DNA and more nonmyogenic than myogenic tissue. Thus, a "Desmin Factor" was derived which predicts "quality" of the human muscle tissue growing in vivo. This factor may serve as a prognostic tool.
Collapse
Affiliation(s)
- Ralf Schäfer
- Department of Physiology, University of Bonn, Bonn, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Bartoli M, Richard I. Calpains in muscle wasting. Int J Biochem Cell Biol 2005; 37:2115-33. [PMID: 16125114 DOI: 10.1016/j.biocel.2004.12.012] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 12/01/2004] [Accepted: 12/31/2004] [Indexed: 01/09/2023]
Abstract
Calpains are intracellular nonlysosomal Ca(2+)-regulated cysteine proteases. They mediate regulatory cleavages of specific substrates in a large number of processes during the differentiation, life and death of the cell. The purpose of this review is to synthesize our current understanding of the participation of calpains in muscle atrophy. Muscle tissue expresses mainly three different calpains: the ubiquitous calpains and calpain 3. The participation of the ubiquitous calpains in the initial degradation of myofibrillar proteins occurring in muscle atrophy as well as in the necrosis process accompanying muscular dystrophies has been well characterized. Inactivating mutations in the calpain 3 gene are responsible for limb-girdle muscular dystrophy type 2A and calpain 3 has been found to be downregulated in different atrophic situations, suggesting that it has to be absent for the atrophy to occur. The fact that similar regulations of calpain activities occur during exercise as well as in atrophy led us to propose that the calpains control cytoskeletal modifications needed for muscle plasticity.
Collapse
Affiliation(s)
- Marc Bartoli
- Généthon, Centre National de la Recherche Scientifique UMR 8115, 1 bis rue de l'Internationale, 91000 Evry, France
| | | |
Collapse
|
25
|
Matecki S, Guibinga GH, Petrof BJ. Regenerative capacity of the dystrophic (mdx) diaphragm after induced injury. Am J Physiol Regul Integr Comp Physiol 2004; 287:R961-8. [PMID: 15191902 DOI: 10.1152/ajpregu.00146.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Duchenne muscular dystrophy is characterized by myofiber necrosis, muscle replacement by connective tissue, and crippling weakness. Although the mdx mouse also lacks dystrophin, most muscles show little myofiber loss or functional impairment. An exception is the mdx diaphragm, which is phenotypically similar to the human disease. Here we tested the hypothesis that the mdx diaphragm has a defective regenerative response to necrotic injury, which could account for its severe phenotype. Massive necrosis was induced in mdx and wild-type (C57BL10) mouse diaphragms in vivo by topical application of notexin, which destroys mature myofibers while leaving myogenic precursor satellite cells intact. At 4 h after acute exposure to notexin, >90% of diaphragm myofibers in both wild-type and mdx mice demonstrated pathological sarcolemmal leakiness, and there was a complete loss of isometric force-generating capacity. Both groups of mice showed strong expression of embryonic myosin within the diaphragm at 5 days, which was largely extinguished by 20 days after injury. At 60 days postinjury, wild-type diaphragms exhibited a persistent loss ( approximately 25%) of isometric force-generating capacity, associated with a trend toward increased connective tissue infiltration. In contrast, mdx diaphragms achieved complete functional recovery of force generation to noninjured values, and there was no increase in muscle connective tissue over baseline. These data argue against any loss of intrinsic regenerative capacity within the mdx diaphragm, despite characteristic features of major dystrophic pathology being present. Our findings support the concept that significant latent regenerative capacity resides within dystrophic muscles, which could potentially be exploited for therapeutic purposes.
Collapse
Affiliation(s)
- Stefan Matecki
- Respiratory Div., Rm. L411, Royal Victoria Hospital, 687 Pine Ave. West, Montreal, Quebec H3A 1A1, Canada
| | | | | |
Collapse
|
26
|
Martin B, Schneider R, Janetzky S, Waibler Z, Pandur P, Kühl M, Behrens J, von der Mark K, Starzinski-Powitz A, Wixler V. The LIM-only protein FHL2 interacts with beta-catenin and promotes differentiation of mouse myoblasts. J Cell Biol 2002; 159:113-22. [PMID: 12370240 PMCID: PMC2173499 DOI: 10.1083/jcb.200202075] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
FHL2 is a LIM-domain protein expressed in myoblasts but down-regulated in malignant rhabdomyosarcoma cells, suggesting an important role of FHL2 in muscle development. To investigate the importance of FHL2 during myoblast differentiation, we performed a yeast two-hybrid screen using a cDNA library derived from myoblasts induced for differentiation. We identified beta-catenin as a novel interaction partner of FHL2 and confirmed the specificity of association by direct in vitro binding tests and coimmunoprecipitation assays from cell lysates. Deletion analysis of both proteins revealed that the NH2-terminal part of beta-catenin is sufficient for binding in yeast, but addition of the first armadillo repeat is necessary for binding FHL2 in mammalian cells, whereas the presence of all four LIM domains of FHL2 is needed for the interaction. Expression of FHL2 counteracts beta-catenin-mediated activation of a TCF/LEF-dependent reporter gene in a dose-dependent and muscle cell-specific manner. After injection into Xenopus embryos, FHL2 inhibited the beta-catenin-induced axis duplication. C2C12 mouse myoblasts stably expressing FHL2 show increased myogenic differentiation reflected by accelerated myotube formation and expression of muscle-specific proteins. These data imply that FHL2 is a muscle-specific repressor of LEF/TCF target genes and promotes myogenic differentiation by interacting with beta-catenin.
Collapse
Affiliation(s)
- Bernd Martin
- Institut der Anthropologie und Humangenetik für Biologen, Johann-Wolfgang-Goethe-Universität, 60323 Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Luz MAM, Marques MJ, Santo Neto H. Impaired regeneration of dystrophin-deficient muscle fibers is caused by exhaustion of myogenic cells. Braz J Med Biol Res 2002; 35:691-5. [PMID: 12045834 DOI: 10.1590/s0100-879x2002000600009] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Duchenne muscular dystrophy is one of the most devastating myopathies. Muscle fibers undergo necrosis and lose their ability to regenerate, and this may be related to increased interstitial fibrosis or the exhaustion of satellite cells. In this study, we used mdx mice, an animal model of Duchenne muscular dystrophy, to assess whether muscle fibers lose their ability to regenerate after repeated cycles of degeneration-regeneration and to establish the role of interstitial fibrosis or exhaustion of satellite cells in this process. Repeated degenerative-regenerative cycles were induced by the injection of bupivacaine (33 mg/kg), a myotoxic agent. Bupivacaine was injected weekly into the right tibialis anterior muscle of male, 8-week-old mdx (N = 20) and C57Bl/10 (control, N = 10) mice for 20 and 50 weeks. Three weeks after the last injection, the mice were killed and the proportion of regenerated fibers was counted and reported as a fibrosis index. Twenty weekly bupivacaine injections did not change the ability of mdx muscle to regenerate. However, after 50 weekly bupivacaine injections, there was a significant decrease in the regenerative response. There was no correlation between the inability to regenerate and the increase in interstitial fibrosis. These results show that after prolonged repeated cycles of degeneration-regeneration, mdx muscle loses its ability to regenerate because of the exhaustion of satellite cells, rather than because of an increase in interstitial fibrosis. This finding may be relevant to cell and gene therapy in the treatment of Duchenne muscular dystrophy.
Collapse
Affiliation(s)
- M A M Luz
- Departamento de Anatomia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | | | | |
Collapse
|
28
|
Blake DJ, Weir A, Newey SE, Davies KE. Function and genetics of dystrophin and dystrophin-related proteins in muscle. Physiol Rev 2002; 82:291-329. [PMID: 11917091 DOI: 10.1152/physrev.00028.2001] [Citation(s) in RCA: 827] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The X-linked muscle-wasting disease Duchenne muscular dystrophy is caused by mutations in the gene encoding dystrophin. There is currently no effective treatment for the disease; however, the complex molecular pathology of this disorder is now being unravelled. Dystrophin is located at the muscle sarcolemma in a membrane-spanning protein complex that connects the cytoskeleton to the basal lamina. Mutations in many components of the dystrophin protein complex cause other forms of autosomally inherited muscular dystrophy, indicating the importance of this complex in normal muscle function. Although the precise function of dystrophin is unknown, the lack of protein causes membrane destabilization and the activation of multiple pathophysiological processes, many of which converge on alterations in intracellular calcium handling. Dystrophin is also the prototype of a family of dystrophin-related proteins, many of which are found in muscle. This family includes utrophin and alpha-dystrobrevin, which are involved in the maintenance of the neuromuscular junction architecture and in muscle homeostasis. New insights into the pathophysiology of dystrophic muscle, the identification of compensating proteins, and the discovery of new binding partners are paving the way for novel therapeutic strategies to treat this fatal muscle disease. This review discusses the role of the dystrophin complex and protein family in muscle and describes the physiological processes that are affected in Duchenne muscular dystrophy.
Collapse
Affiliation(s)
- Derek J Blake
- Medical Research Council, Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | | | | |
Collapse
|
29
|
Link D, Irintchev A, Knauf U, Wernig A, Starzinski-Powitz A. A model system for studying postnatal myogenesis with tetracycline-responsive, genetically engineered clonal myoblasts in vitro and in vivo. Exp Cell Res 2001; 270:138-50. [PMID: 11640878 DOI: 10.1006/excr.2001.5340] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this work was to introduce a tetracycline-responsive (Tet-off) gene expression system into myoblasts in order to regulate a reporter gene not only in vitro but also particularly in muscles implanted with these engineered myoblasts. Mouse myoblasts from a long-term culture (i28 cells) were transfected initially to generate and characterize two stable master clones expressing tetracycline-responsive transactivator protein tTA. Like parental i28 myoblasts, these clones differentiated well in vitro. The second step introduced the firefly (Photinus pyralis) luciferase gene into one of the stable tTA clones producing double transfectants expressing luciferase in the absence of tetracycline. Addition of tetracycline (1 microg ml(-1)) resulted in at least 100-fold decreases in luciferase activity within 8 h in both growing and differentiating myoblast cultures. Enzyme activity was rapidly restored after tetracycline was removed (8 h). After successful implantation of these myoblasts into damaged mouse muscles, luciferase expression in the matured progeny cells could be regulated by oral application of doxycycline for at least 1 month. The tetracycline-responsive master clones are potentially powerful tools for studying the function of various genes in postnatal myogenesis.
Collapse
Affiliation(s)
- D Link
- Xantos Biomedicine AG, Fraunhoferstrasse 22, Martinsried, D-82152, Germany
| | | | | | | | | |
Collapse
|
30
|
Guibinga GH, Ebihara S, Nalbantoglu J, Holland P, Karpati G, Petrof BJ. Forced myofiber regeneration promotes dystrophin gene transfer and improved muscle function despite advanced disease in old dystrophic mice. Mol Ther 2001; 4:499-507. [PMID: 11708887 DOI: 10.1006/mthe.2001.0482] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by defects in the dystrophin gene. In young dystrophic mdx mice, immature regenerating myofibers represent the principal substrate for adenovirus vector (AdV)-mediated dystrophin gene transfer. However, in DMD patients immature regenerating myofibers are generally sparse. Such a situation also exists in old mdx mice, which may represent a more realistic model. Therefore, here we have used old mdx mice (of 14- to 17 months of age) to test the hypothesis that one-time administration of a myonecrotic agent can transiently re-establish a population of immature myofibers susceptible to AdV-mediated dystrophin gene transfer. This strategy led to upregulation of the coxsackie/adenovirus attachment receptor by means of induction of regenerating myofibers, significantly augmented AdV-mediated dystrophin gene expression, and enhanced force-generating capacity. In addition, it led to an increased resistance to contraction-induced injury compared with untreated controls. The latter protective effect was positively correlated with the number of dystrophin-expressing myofibers (r=0.83, P<0.05). Accordingly, the risk:benefit ratio associated with the sequential use of forced myofiber regeneration and AdV-mediated dystrophin gene transfer was favorable in old mdx mice despite advanced disease. These findings have implications for the potential applicability of AdV-mediated gene therapy to DMD and other muscle diseases in which immature regenerating myofibers are lacking.
Collapse
Affiliation(s)
- G H Guibinga
- Respiratory Division, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada H3A 1A1
| | | | | | | | | | | |
Collapse
|
31
|
Reimann J, Irintchev A, Wernig A. Regenerative capacity and the number of satellite cells in soleus muscles of normal and mdx mice. Neuromuscul Disord 2000; 10:276-82. [PMID: 10838255 DOI: 10.1016/s0960-8966(99)00118-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Satellite cells are potential myogenic cells that participate in repair and growth of muscle fibres. In this investigation, the change in the number of satellite cells following severe muscle damage was monitored in soleus muscle of age-matched mdx and C57Bl/10 mice. Satellite cells were identified immunohistochemically in the light microscope by their association with a recently described marker protein, M-cadherin, and their location between the muscle fibre's sarcolemma and the surrounding basal lamina. In cross-sections of untreated soleus muscle of C57Bl/10 mice at 11-14. 5 months of age, nuclei of M-cadherin positive satellite cells on average amounted to 3.4% of the total number of myonuclei. Surprisingly, significantly higher numbers of satellite cell nuclei, both in absolute numbers (mean 24+/-11 versus 40+/-11 satellite cells per section) and relative to the total number of myonuclei (5. 3%), were found in similarly aged animals in which severe muscle damage had been inflicted 3-6 months before. Cross-sectional area, muscle tissue area and myonuclei counts had recovered to control values. In untreated muscles of age-matched mdx mice satellite cell counts were not different (2.7% of myonuclei) from C57Bl/10 mice. However, regeneration showed marked deficits, as there was a loss of about 36% total cross-sectional area, about 48% total muscle fibre area and about 43% myonuclei per section compared to the untreated mdx muscles. Furthermore, the absolute number of satellite cells decreased from 20+/-11 to 12+/-8 per section. The relative number of satellite cell nuclei remained comparable to, but did not exceed, the undamaged muscles. The poor recovery of muscle and the missing post-regeneration rise in satellite cell numbers may indicate the reproductive limits of the satellite pool.
Collapse
MESH Headings
- Animals
- Biomarkers
- Cadherins/metabolism
- Cell Count
- Disease Models, Animal
- Fibrosis/pathology
- Fibrosis/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle, Skeletal/injuries
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Regeneration/physiology
Collapse
Affiliation(s)
- J Reimann
- Department of Physiology, Neurophysiology, University of Bonn, Wilhelmstrasse 31, D-53111, Bonn, Germany
| | | | | |
Collapse
|
32
|
Abstract
1. Mdx mice were used as a model for Duchenne muscular dystrophy; both lack dystrophin. It was hypothesized that the mdx condition would have a marked effect on the ability of diaphragm muscle from mdx mice to do active net work and generate power. This hypothesis was tested using the work-loop technique. 2. Specific twitch force, specific tetanic force and maximum power were all significantly less in diaphragm strips from mdx mice than those from control mice. 3. In all preparations muscle length at which maximum power was achieved (Lw) was about 8% less than that at which maximum tetanic force was achieved (L0), both in mdx and control muscle. 4. The isometric force-length curve for mdx muscle was steeper on both sides of the plateau. Similarly, the curve relating net work per cycle to muscle length was steeper for mdx muscle on both sides of the plateau. 5. Maximum power of mdx muscle was achieved at a lower strain than for control muscle; maximum power occurred at a strain of 10.2% for mdx and 14.7% for control. Further increases in strain caused a marked decrease of power production in mdx muscle, whereas they caused a smaller decrease in control muscle. 6. In summary, at muscle lengths longer than Lw and at high strains, performance of mdx muscle was compromised relative to that of control muscle. Work and power were compromised more than isometric force.
Collapse
Affiliation(s)
- E D Stevens
- Institute of Gerontology, University of Michigan, Ann Arbor, USA.
| | | |
Collapse
|
33
|
Wernig A, Zweyer M, Irintchev A. Function of skeletal muscle tissue formed after myoblast transplantation into irradiated mouse muscles. J Physiol 2000; 522 Pt 2:333-45. [PMID: 10639108 PMCID: PMC2269750 DOI: 10.1111/j.1469-7793.2000.t01-2-00333.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
1. Pretreatment of muscles with ionising radiation enhances tissue formation by transplanted myoblasts but little is known about the effects on muscle function. We implanted myoblasts from an expanded, male-donor-derived, culture (i28) into X-ray irradiated (16 Gy) or irradiated and damaged soleus muscles of female syngeneic mice (Balb/c). Three to 6 months later the isometric contractile properties of the muscles were studied in vitro, and donor nuclei were visualised in muscle sections with a Y chromosome-specific DNA probe. 2. Irradiated sham-injected muscles had smaller masses than untreated solei and produced less twitch and tetanic force (all by about 18 %). Injection of 106 myoblasts abolished these deficiencies and innervation appeared normal. 3. Cryodamage of irradiated solei produced muscle remnants with few (1-50) or no fibres. Additional myoblast implantation led to formation of large muscles (25 % above normal) containing numerous small-diameter fibres. Upon direct electrical stimulation, these muscles produced considerable twitch (53 % of normal) and tetanic forces (35 % of normal) but innervation was insufficient as indicated by weak nerve-evoked contractions and elevated ACh sensitivity. 4. In control experiments on irradiated muscles, reinnervation was found to be less complete after botulinum toxin paralysis than after nerve crush indicating that proliferative arrest of irradiated Schwann cells may account for the observed innervation deficits. 5. Irradiation appears to be an effective pretreatment for improving myoblast transplantation. The injected cells can even produce organised contractile tissue replacing whole muscle. However, impaired nerve regeneration limits the functional performance of the new muscle.
Collapse
Affiliation(s)
- A Wernig
- Department of Physiology, Neurophysiology, University of Bonn, Wilhelmstrasse 31, D-53111 Bonn, Germany.
| | | | | |
Collapse
|
34
|
Irintchev A, Rosenblatt JD, Cullen MJ, Zweyer M, Wernig A. Ectopic skeletal muscles derived from myoblasts implanted under the skin. J Cell Sci 1998; 111 ( Pt 22):3287-97. [PMID: 9788871 DOI: 10.1242/jcs.111.22.3287] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the potential of cultured myoblasts to generate skeletal muscle in an ectopic site. Myoblasts from a clonal cell line or from expanded primary cultures were injected under the skin of the lumbar region of adult syngenic Balb/c mice. One to 7 weeks after injection, distinct muscles, of greater mass in mice injected with clonal myoblasts (6–78 mg, n=37) than in mice injected with primary myoblasts (1–7 mg, n=26), had formed between the subcutaneous panniculus carnosus muscle and the trunk muscles of host animals. These ectopic muscles exhibited spontaneous and/or electrically-evoked contractions after the second week and, when stimulated directly in vitro, isometric contractile properties similar to those of normal muscles. Histological, electron microscopical and tissue culture examination of these muscles revealed their largely mature morphology and phenotype. The fibres, most of which were branched, were contiguous, aligned and capillarised, exhibited normal sarcormeric protein banding patterns, and expressed muscle-specific proteins, including desmin, dystrophin, and isoforms of developmental and adult myosin heavy chain. Enveloping each fibre was a basal lamina, beneath which lay quiescent satellite cells, which could be stimulated to produce new muscle in culture. Presence of endplates (revealed by alpha-bungarotoxin and neurofilament staining), and the eventual loss of expression of neural cell adhesion molecule and extrasynaptic acetylcholine receptors, indicated that some fibres were innervated. That these muscle fibres were of implanted-cell origin was supported by the finding of Y-chromosome and a lack of dystrophin in ectopic muscles formed after subcutaneous injection of, respectively, male myoblasts into female mice and dystrophin-deficient (mdx) myoblasts into normal C57Bl/10 muscle. Our results demonstrate that an organised, functional muscle can be generated de novo from a disorganised mass of myoblasts implanted in an extramuscular subcutaneous site, whereby the host contributes significantly in providing support tissues and innervation. Our observations are also consistent with the idea that myogenic cells behave like tissue-specific stem cells, generating new muscle precursor (satellite) cells as well as mature muscle. Subcutaneous implantation of myoblasts may have a range of useful applications, from the study of myogenesis to the delivery of gene products.
Collapse
MESH Headings
- Animals
- Clone Cells
- Female
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred mdx
- Microscopy, Electron
- Muscle Contraction/physiology
- Muscle Fibers, Skeletal/chemistry
- Muscle Fibers, Skeletal/transplantation
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/cytology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/physiology
- Myosin Heavy Chains/analysis
- Receptors, Cholinergic/analysis
- Skin
Collapse
Affiliation(s)
- A Irintchev
- Department of Physiology, Neurophysiology, University of Bonn, Wilhelmstrasse 31, D-53111 Bonn, Germany
| | | | | | | | | |
Collapse
|
35
|
Brussee V, Merly F, Tardif F, Tremblay JP. Normal myoblast implantation in MDX mice prevents muscle damage by exercise. Biochem Biophys Res Commun 1998; 250:321-7. [PMID: 9753628 DOI: 10.1006/bbrc.1998.9276] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One consequence of the lack of dystrophin is a higher vulnerability of myofibers to eccentric exercise. In this study, we compared the effect of downhill running on Biceps brachii of MDX mice with or without transplantation of normal myoblasts. Exercise induced damaged was detected by Evans blue staining. In control MDX mice, 26.3% of the fibers were permeated by this dye, myoblast transplantation prevented such necrosis. In the transplanted muscles, only dystrophin negative fibers were injured. Indeed, in muscles containing at least 40% dystrophin positive fibers, the damage was significantly reduced in the grafted muscle. Thus the transplantation of normal myoblasts increases the resistance of dystrophic muscles to exercise. Our results suggest that transplantation of normal myoblasts to DMD patients may have beneficial effects.
Collapse
Affiliation(s)
- V Brussee
- Unité de recherche en Génétique Humaine, CHUL, Ste Foy, Canada
| | | | | | | |
Collapse
|