Abstract
NG2 is the rat homologue of the human melanoma chondroitin sulfate proteoglycan (MCSP) preferentially expressed in dividing progenitor cells of the glial and mesenchymal lineage but downregulated after differentiation. It has recently been demonstrated that MCSP/NG2 expression is not restricted to mitotic or malignant cells. We show that MCSP/NG2 expression is detectable in the sarcolemma, and in the neuromuscular junction of human postnatal skeletal muscle, and it gradually reduces with advancing age. In human and murine myogenic cell lines, we found no clear differences in MCSP/NG2 expression between myoblasts and myotubes. Reduced levels of the core protein were found in merosin-negative congenital muscular dystrophy (MDC1A). Duchenne muscular dystrophy patients muscles exhibited an overexpression of the MCSP/NG2 core protein. In gamma-sarcoglycanopathy and calpainopathy, MCSP/NG2 upregulation was restricted to regenerating myofibers. We demonstrate that MCSP/NG2 is expressed in differentiated myofibers, and appears to have a role in the pathogenesis of MDC1A and severe dystrophinopathies.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adolescent
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Adult
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Aging / genetics
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Aging / metabolism
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Animals
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Antigens / genetics
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Antigens / metabolism*
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Calpain / deficiency
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Calpain / genetics
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Cell Differentiation / genetics
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Child
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Child, Preschool
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Chondroitin Sulfate Proteoglycans / genetics
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Chondroitin Sulfate Proteoglycans / metabolism*
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Cytoskeletal Proteins / deficiency
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Cytoskeletal Proteins / genetics
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Down-Regulation / genetics
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Gene Expression Regulation, Developmental / genetics
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Humans
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Infant
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Infant, Newborn
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Membrane Glycoproteins / deficiency
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Membrane Glycoproteins / genetics
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mice
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Middle Aged
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Muscle Fibers, Skeletal / cytology
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Muscle Fibers, Skeletal / metabolism*
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Muscle, Skeletal / cytology
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Muscle, Skeletal / growth & development*
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Muscle, Skeletal / metabolism*
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Muscular Dystrophy, Duchenne / genetics
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Muscular Dystrophy, Duchenne / metabolism*
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Muscular Dystrophy, Duchenne / physiopathology
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Myoblasts / cytology
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Myoblasts / metabolism
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Neuromuscular Junction / cytology
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Neuromuscular Junction / growth & development
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Neuromuscular Junction / metabolism
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Proteoglycans / genetics
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Proteoglycans / metabolism*
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Sarcoglycans
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Sarcolemma / metabolism*
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Sarcolemma / ultrastructure
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Tumor Cells, Cultured
Substances
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Antigens
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CSPG4 protein, human
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Chondroitin Sulfate Proteoglycans
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Cytoskeletal Proteins
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Membrane Glycoproteins
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Membrane Proteins
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Proteoglycans
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Sarcoglycans
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chondroitin sulfate proteoglycan 4
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Calpain