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Lee WH, Abe S, Kim HJ, Usami A, Honda A, Sakiyama K, Ide Y. Characteristics of muscle fibers reconstituted in the regeneration process of masseter muscle in an mdx mouse model of muscular dystrophy. J Muscle Res Cell Motil 2006; 27:235-40. [PMID: 16752197 DOI: 10.1007/s10974-006-9066-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 04/07/2006] [Indexed: 10/24/2022]
Abstract
Mdx mice, which lack dystrophin, were examined for changes in the properties of muscle fibers in the growth process of the masseter muscle at the morphological, protein and transcriptional levels. The slow-type isoform, MyHC-1, and the fast-type isoforms, MyHC-2a, MyHC-2d and MyHC-2b, were examined at the protein and the transcriptional level. Morphological examination showed that in the mdx mouse masseter muscle, degeneration, necrosis, and regeneration occurred, particularly at the age of 4 weeks, and many regenerated muscle fibers with centrally located nuclei were observed at the age of 9 weeks. The results of examination at the protein and the transcriptional level showed that in the process of muscle fiber degeneration, necrosis, and regeneration, the mdx mouse masseter muscle acquires muscle fiber characteristics entirely different from those in the normal mouse masseter muscle. In particular, MyHC-1, which is rarely found in normal mice, was very strongly expressed.
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Affiliation(s)
- Won-Hyung Lee
- Department of Anatomy, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan
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52
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Byron CD, Hamrick MW, Wingard CJ. Alterations of temporalis muscle contractile force and histological content from the myostatin and Mdx deficient mouse. Arch Oral Biol 2006; 51:396-405. [PMID: 16263075 DOI: 10.1016/j.archoralbio.2005.09.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 08/31/2005] [Accepted: 09/19/2005] [Indexed: 10/25/2022]
Abstract
Myostatin (GDF8) and dystrophin are critical molecules for muscle organisation. Myostatin is involved in regulating muscle growth and development, whereas dystrophin is part of the dystrophin-glycoprotein complex (DGC), which anchors the cytoskeleton to the sarcolemma. We examined temporalis muscle morphology and function in myostatin deficient and dystrophin deficient (Mdx) mice in order to determine how myostatin and dystrophin affect bite force and muscle fibre composition. Bite forces from 4-month-old myostatin-/-, dystrophin deficient (Mdx) and normal control mice were measured by load cell and field stimulation of the temporalis muscle. Tissue sections were stained with haemotoxylin and eosin (H&E) and the periodic acid-Schiff reaction (PAS) to assess morphology and fibre type differences. A positive relationship between bite force and muscle mass for both genetic models was observed. Both Mstn-/- and Mdx mice showed significant elevation in bite force and muscle mass. Histological examination revealed greater muscle fibre cross-sectional area variability in Mdx mice (ANOVA, F=5.6, P<0.01). Surprisingly, the Mstn-/- mice demonstrated a disproportionate increase in bite force at higher stimulation frequencies with comparison of regression lines for force-frequency data (ANOVA, F=3.46, P<0.07). Muscle fibre typing using a PAS staining technique revealed significantly more type IIx/b glycolytic muscle fibres in the Mstn-/- mice. Our results suggest that histopathologies associated with Mdx mice did not diminish gross temporalis structure or function, whilst the force-frequency changes associated with Mstn-/- mice were reflected in an elevation of type IIx/b fibres.
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Affiliation(s)
- Craig D Byron
- Department of Surgery, CJ-1117, Medical College of Georgia, 1120, 15th Street, Augusta, GA 30912, USA.
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53
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Hnia K, Tuffery-Giraud S, Vermaelen M, Hugon G, Chazalette D, Masmoudi A, Rivier F, Mornet D. Pathological pattern of Mdx mice diaphragm correlates with gradual expression of the short utrophin isoform Up71. Biochim Biophys Acta Mol Basis Dis 2006; 1762:362-72. [PMID: 16457992 PMCID: PMC1974843 DOI: 10.1016/j.bbadis.2005.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Revised: 11/16/2005] [Accepted: 11/18/2005] [Indexed: 12/22/2022]
Abstract
Utrophin gene is transcribed in a large mRNA of 13 kb that codes for a protein of 395 kDa. It shows amino acid identity with dystrophin of up to 73% and is widely expressed in muscle and non-muscle tissues. Up71 is a short utrophin product of the utrophin gene with the same cysteine-rich and C-terminal domains as full-length utrophin (Up395). Using RT-PCR, Western blots analysis, we demonstrated that Up71 is overexpressed in the mdx diaphragm, the most pathological muscle in dystrophin-deficient mdx mice, compared to wild-type C57BL/10 or other mdx skeletal muscles. Subsequently, we demonstrated that this isoform displayed an increased expression level up to 12 months, whereas full-length utrophin (Up395) decreased. In addition, beta-dystroglycan, the transmembrane glycoprotein that anchors the cytoplasmic C-terminal domain of utrophin, showed similar increase expression in mdx diaphragm, as opposed to other components of the dystrophin-associated protein complex (DAPC) such as alpha-dystrobrevin1 and alpha-sarcoglycan. We demonstrated that Up71 and beta-dystroglycan were progressively accumulated along the extrasynaptic region of regenerating clusters in mdx diaphragm. Our data provide novel functional insights into the pathological role of the Up71 isoform in dystrophinopathies.
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Affiliation(s)
- Karim Hnia
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
- Institut Supérieur de Biotechnologie
Faculté de MédecineMonastir,TN
| | - Sylvie Tuffery-Giraud
- Laboratoire de génétique des maladies rares. Pathologie moléculaire, études fonctionnelles et banque de données génétiques
INSERM : U827 IFR3Université Montpellier IIURC
CHU de Montpellier
34093 MONTPELLIER ,FR
| | - Marianne Vermaelen
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
| | - Gerald Hugon
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
| | - Delphine Chazalette
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
| | - Ahmed Masmoudi
- Institut Supérieur de Biotechnologie
Faculté de MédecineMonastir,TN
| | - François Rivier
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
| | - Dominique Mornet
- Laboratoire de Physiologie des Interactions
EA 701Université Montpellier 1Institut de Biologie
Boulevard Henri IV
34060 Montpellier,FR
- * Correspondence should be adressed to: Dominique Mornet
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54
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Thabet M, Miki T, Seino S, Renaud JM. Treadmill running causes significant fiber damage in skeletal muscle of KATP channel-deficient mice. Physiol Genomics 2005; 22:204-12. [PMID: 15914579 DOI: 10.1152/physiolgenomics.00064.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although it has been suggested that the ATP-sensitive K+ (KATP) channel protects muscle against function impairment, most studies have so far given little evidence for significant perturbation in the integrity and function of skeletal muscle fibers from inactive mice that lack KATP channel activity in their cell membrane. The objective was, therefore, to test the hypothesis that KATP channel-deficient skeletal muscle fibers become damaged when mice are subjected to stress. Wild-type and KATP channel-deficient mice (Kir6.2−/− mice) were subjected to 4–5 wk of treadmill running at either 20 m/min with 0° inclination or at 24 m/min with 20° uphill inclination. Muscles of all wild-type mice and of nonexercised Kir6.2−/− mice had very few fibers with internal nuclei. After 4–5 wk of treadmill running, there was little evidence for connective tissues and mononucleated cells in Kir6.2−/− hindlimb muscles, whereas the number of fibers with internal nuclei, which appear when damaged fibers are regenerated by satellite cells, was significantly higher in Kir6.2−/− than wild-type mice. Between 5% and 25% of the total number of fibers in Kir6.2−/− extensor digitum longus, plantaris, and tibialis muscles had internal nuclei, and most of such fibers were type IIB fibers. Contrary to hindlimb muscles, diaphragms of Kir6.2−/− mice that had run at 24 m/min had few fibers with internal nuclei, but mild to severe fiber damage was observed. In conclusion, the study provides for the first time evidence 1) that the KATP channels of skeletal muscle are essential to prevent fiber damage, and thus muscle dysfunction; and 2) that the extent of fiber damage is greater and the capacity of fiber regeneration is less in Kir6.2−/− diaphragm muscles compared with hindlimb muscles.
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Affiliation(s)
- M Thabet
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Yamane A, Akutsu S, Diekwisch TGH, Matsuda R. Satellite cells and utrophin are not directly correlated with the degree of skeletal muscle damage inmdxmice. Am J Physiol Cell Physiol 2005; 289:C42-8. [PMID: 15703201 DOI: 10.1152/ajpcell.00577.2004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To determine whether muscle satellite cells and utrophin are correlated with the degree of damage in mdx skeletal muscles, we measured the area of the degenerative region as an indicator of myofiber degeneration in the masseter, gastrocnemius, soleus, and diaphragm muscles of mdx mice. Furthermore, we analyzed the expression levels of the paired box homeotic gene 7 ( pax7), m-cadherin (the makers of muscle satellite cells), and utrophin mRNA. We also investigated the immunolocalization of m-cadherin and utrophin proteins in the muscles of normal C57BL/10J (B10) and mdx mice. The expression level of pax7 mRNA and the percentage of m-cadherin-positive cells among the total number of cell nuclei in the muscle tissues in all four muscles studied were greater in the mdx mice than in the B10 mice. However, there was no significant correlation between muscle damage and expression level for pax7 mRNA ( R = −0.140), nor was there a correlation between muscle damage and the percentage of satellite cells among the total number of cell nuclei ( R = −0.411) in the mdx mice. The expression level of utrophin mRNA and the intensity of immunostaining for utrophin in all four muscles studied were greater in the mdx mice than in the B10 mice. However, there also was not a significant correlation between muscle damage and expression level of utrophin mRNA ( R = 0.231) in the mdx mice, although upregulated utrophin was incorporated into the sarcolemma. These results suggest that satellite cells and utrophin are not directly correlated with the degree of skeletal muscle damage in mdx mice.
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MESH Headings
- Animals
- Cadherins/genetics
- Homeodomain Proteins/genetics
- Immunohistochemistry
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- PAX7 Transcription Factor
- Polymerase Chain Reaction
- RNA, Messenger/metabolism
- Satellite Cells, Perineuronal/pathology
- Utrophin/genetics
- Utrophin/metabolism
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Affiliation(s)
- Akira Yamane
- Department of Pharmacology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
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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.
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Affiliation(s)
- Stefan Matecki
- Respiratory Div., Rm. L411, Royal Victoria Hospital, 687 Pine Ave. West, Montreal, Quebec H3A 1A1, Canada
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57
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Collins CA, Morgan JE. Duchenne's muscular dystrophy: animal models used to investigate pathogenesis and develop therapeutic strategies. Int J Exp Pathol 2003; 84:165-72. [PMID: 14632630 PMCID: PMC2517561 DOI: 10.1046/j.1365-2613.2003.00354.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Duchenne's muscular dystrophy (DMD) is a lethal childhood disease caused by mutations of the dystrophin gene, the protein product of which, dystrophin, has a vital role in maintaining muscle structure and function. Homologues of DMD have been identified in several animals including dogs, cats, mice, fish and invertebrates. The most notable of these are the extensively studied mdx mouse, a genetic and biochemical model of the human disease, and the muscular dystrophic Golden Retriever dog, which is the nearest pathological counterpart of DMD. These models have been used to explore potential therapeutic approaches along a number of avenues including gene replacement and cell transplantation strategies. High-throughput screening of pharmacological and genetic therapies could potentially be carried out in recently available smaller models such as zebrafish and Caenorhabditis elegans. It is possible that a successful treatment will eventually be identified through the integration of studies in multiple species differentially suited to addressing particular questions.
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Affiliation(s)
- C A Collins
- Muscle Cell Biology Group, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, Hammersmith Hospital, London, UK.
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Bonuccelli G, Sotgia F, Schubert W, Park DS, Frank PG, Woodman SE, Insabato L, Cammer M, Minetti C, Lisanti MP. Proteasome inhibitor (MG-132) treatment of mdx mice rescues the expression and membrane localization of dystrophin and dystrophin-associated proteins. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 163:1663-75. [PMID: 14507673 PMCID: PMC1868305 DOI: 10.1016/s0002-9440(10)63523-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene, is absent in the skeletal muscle of DMD patients and mdx mice. At the plasma membrane of skeletal muscle fibers, dystrophin associates with a multimeric protein complex, termed the dystrophin-glycoprotein complex (DGC). Protein members of this complex are normally absent or greatly reduced in dystrophin-deficient skeletal muscle fibers, and are thought to undergo degradation through an unknown pathway. As such, we reasoned that inhibition of the proteasomal degradation pathway might rescue the expression and subcellular localization of dystrophin-associated proteins. To test this hypothesis, we treated mdx mice with the well-characterized proteasomal inhibitor MG-132. First, we locally injected MG-132 into the gastrocnemius muscle, and observed the outcome after 24 hours. Next, we performed systemic treatment using an osmotic pump that allowed us to deliver different concentrations of the proteasomal inhibitor, over an 8-day period. By immunofluorescence and Western blot analysis, we show that administration of the proteasomal inhibitor MG-132 effectively rescues the expression levels and plasma membrane localization of dystrophin, beta-dystroglycan, alpha-dystroglycan, and alpha-sarcoglycan in skeletal muscle fibers from mdx mice. Furthermore, we show that systemic treatment with the proteasomal inhibitor 1) reduces muscle membrane damage, as revealed by vital staining (with Evans blue dye) of the diaphragm and gastrocnemius muscle isolated from treated mdx mice, and 2) ameliorates the histopathological signs of muscular dystrophy, as judged by hematoxylin and eosin staining of muscle biopsies taken from treated mdx mice. Thus, the current study opens new and important avenues in our understanding of the pathogenesis of DMD. Most importantly, these new findings may have clinical implications for the pharmacological treatment of patients with DMD.
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Affiliation(s)
- Gloria Bonuccelli
- Department of Molecular Pharmacology and The Albert Einstein Cancer Center, Albert Einstein School of Medicine, Bronx, New York 10461, USA
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Tseng BS, Zhao P, Pattison JS, Gordon SE, Granchelli JA, Madsen RW, Folk LC, Hoffman EP, Booth FW. Regenerated mdx mouse skeletal muscle shows differential mRNA expression. J Appl Physiol (1985) 2002; 93:537-45. [PMID: 12133862 DOI: 10.1152/japplphysiol.00202.2002] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Despite over 3,000 articles published on dystrophin in the last 15 years, the reasons underlying the progression of the human disease, differential muscle involvement, and disparate phenotypes in different species are not understood. The present experiment employed a screen of 12,488 mRNAs in 16-wk-old mouse mdx muscle at a time when the skeletal muscle is avoiding severe dystrophic pathophysiology, despite the absence of a functional dystrophin protein. A number of transcripts whose levels differed between the mdx and human Duchenne muscular dystrophy were noted. A fourfold decrease in myostatin mRNA in the mdx muscle was noted. Differential upregulation of actin-related protein 2/3 (subunit 4), beta-thymosin, calponin, mast cell chymase, and guanidinoacetate methyltransferase mRNA in the more benign mdx was also observed. Transcripts for oxidative and glycolytic enzymes in mdx muscle were not downregulated. These discrepancies could provide candidates for salvage pathways that maintain skeletal muscle integrity in the absence of a functional dystrophin protein in mdx skeletal muscle.
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Affiliation(s)
- B S Tseng
- Division of Child Neurology, Department of Neurology, University of California at San Francisco, San Francisco, California 94143, USA
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