Transforming growth factor-beta2 is elevated in skeletal muscle disorders.
The transforming growth factor betas (TGF-betas) are multifunctional growth factors that act on both fibroblasts and myosatellite cells. In rodent models of muscle diseases, high levels of TGF-beta2 are expressed by myogenic cells. We have examined whether the expression of TGF-beta2 is also elevated in diseased human muscles. The disorders examined were Duchenne muscular dystrophy, myotonic dystrophy, myotubular myopathy, spinal muscular atrophy, and amyotrophic lateral sclerosis. The levels of TGF-beta2 immunoreactivity were elevated in atrophic, necrotic, and regenerating fibers and in fibers with central nuclei or cytoplasmic masses, irrespective of whether fibrosis was present. We therefore suggest that TGF-beta2 is important for muscle repair and that the presence of a TGF-beta within a muscle only leads to fibrosis if certain other factors are present.
Department of Anatomy and Structural Biology, University of Otago, P. O. Box 913, Dunedin, New Zealand.
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N
Murakami
I S
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McLennan
I
I
Nonaka
K
K
Koishi
C
C
Baker
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Hammond-Tooke
D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism / Q000473:pathology; D000818:Animals; D001706:Biopsy; D016022:Case-Control Studies; D003893:Desmin / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D018482:Muscle, Skeletal / Q000378:metabolism*; D009134:Muscular Atrophy, Spinal / Q000378:metabolism / Q000473:pathology; D009135:Muscular Diseases / Q000378:metabolism*; D009136:Muscular Dystrophies / Q000378:metabolism / Q000473:pathology; D051381:Rats; D013045:Species Specificity; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D003893:Desmin; D016212:Transforming Growth Factor beta