Skeletal Muscle Satellite Cells: Identification of a Heparan Sulfate Proteoglycan

Skeletal muscle fibers are surrounded by an extracellular matrix. The extracellular matrix is composed of gly cop rote ins, collagen, and pro teogly cans. Proteoglycans have been suggested by different reports to play an important functional role in tissue differentiation. However, an understanding of how protcoglycans modulate skeletal muscle differentiation and the activation of myogenic satellite cells is largely unknown. In the present study, chicken pectoral muscle satellite cells were screened for the synthesis and localization of a heparan sulfate proteoglycan during satellite ceil proliferation and differentiation. A heparan sulfate proteoglycan was detected during the proliferative phase of cell growth. After the induction of fusion, the heparan sulfate protcoglycan had both an intracellular and extracellular distribution. Based on the reported function of heparan sulfate proteoglycans as a modulator of basic fibroblast growth factor activity, it is possible that a satellite cell produced heparan sulfate proteoglycan may interact with basie fibroblast growth factor and be a key component in the satellite cell response to basie fibroblast growth factor.