The effect of fibroblast growth factor 2 on the in vitro expression of syndecan-4 and glypican-1 in turkey satellite cells.

The membrane-associated heparan sulfate proteoglycan families, consisting of the syndecans and glypicans, are low-affinity receptors for fibroblast growth factor 2 (FGF2) that are essential in regulating the cellular response to FGF2. Fibroblast growth factor 2 is a potent stimulator of skeletal muscle cell proliferation and a strong inhibitor of differentiation. The regulation of the expression of the syndecans and glypicans will likely play a role in modulating the effects of FGF2 on cellular growth properties. In the present study, the effect of FGF2 on the expression of syndecan-4 and glypican-1 was measured by real-time PCR during turkey myogenic satellite cell proliferation and differentiation in vitro. Both syndecan-4 and glypican-1 transcription were influenced by the addition of exogenous FGF2. Syndecan-4 mRNA expression was reduced only during proliferation, whereas glypican-1 expression was reduced during both proliferation and differentiation. These results suggest that FGF2 growth factor signaling is, in part, regulated by an autoregulatory loop involving FGF2 regulation of syndecan-4 and glypican-1 expression and will affect the growth of skeletal muscle by modulating the proliferation and differentiation of satellite cells.