Human melanoma/NG2 chondroitin sulfate proteoglycan is expressed in the sarcolemma of postnatal human skeletal myofibers. Abnormal expression in merosin-negative and Duchenne muscular dystrophies.
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.
Petrini
Stefania
S
Unit of Molecular Medicine, Bambino Gesù Hospital IRCCS, Rome, Italy. petrini.s@tiscalinet.it
Tessa
Alessandra
A
Carrozzo
Rosalba
R
Verardo
Margherita
M
Pierini
Roberta
R
Rizza
Teresa
T
Bertini
Enrico
E
D000293:Adolescent; D000328:Adult; D000375:Aging / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000941:Antigens / Q000235:genetics / Q000378:metabolism*; D002154:Calpain / Q000172:deficiency / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000172:deficiency / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D009469:Neuromuscular Junction / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism*; D049031:Sarcoglycans; D012508:Sarcolemma / Q000378:metabolism* / Q000648:ultrastructure; D014407:Tumor Cells, Cultured; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D002154:Calpain; D011508:Chondroitin Sulfate Proteoglycans; D003598:Cytoskeletal Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011509:Proteoglycans; D049031:Sarcoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4; C101390:CSPG4 protein, human