Regulation of skeletal muscle satellite cell proliferation and differentiation by transforming growth factor-beta, insulin-like growth factor I, and fibroblast growth factor.
Skeletal muscle satellite cells were cultured from mature rats and were treated in vitro with various combinations of transforming growth factor (TGF)-beta, fibroblast growth factor (FGF), and insulin-like growth factor I (IGF-I). In serum-free defined medium the following observations were made: TGF-beta depressed proliferation and inhibited differentiation; FGF stimulated proliferation and depressed differentiation; IGF-I stimulated proliferation to a small degree but demonstrated a more pronounced stimulation of differentiation. In evaluating combinations of these three factors, the differentiation inhibiting effect of TGF-beta could not be counteracted by any combination of IGF-I or FGF. The proliferation-depressing activity of TGF-beta, however, could not inhibit the mitogenic activity of FGF. Maximum stimulation of proliferation was observed in the presence of both FGF and IGF-I. The highest percentage fusion was also observed under these conditions, but differentiation with minimal proliferation resulted from treatment with IGF-I, alone. By altering the concentrations of TGF-beta, FGF, and IGF-I, satellite cells can be induced to proliferate, differentiate, or to remain quiescent.
Allen
R E
RE
Department of Animal Sciences, University of Arizona, Tucson 85721.
Boxhorn
L K
LK
D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008297:Male; D009132:Muscles / Q000166:cytology*; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000494:pharmacology*; D015291:Transforming Growth Factors / Q000494:pharmacology*
D013002:Somatomedins; D005346:Fibroblast Growth Factors; D007334:Insulin-Like Growth Factor I; D015291:Transforming Growth Factors