BASIC FIBROBLAST GROWTH-FACTOR REGULATES TYPE-I COLLAGEN AND COLLAGENASE GENE-EXPRESSION IN HUMAN SMOOTH-MUSCLE CELLS

Basic fibroblast growth factor (bFGF) is a multifunctional peptide wel l known for angiogenic, neurotropic, and mesoderm-inducing effects. In the present study, rue have investigated the effects of bFGF on colla gen and collagenase gene expression in human iliac arterial smooth mus cle cells. We report that bFGF inhibits type I collagen gene expressio n and collagen biosynthesis, with concomitant stimulation of collagena se gene expression. The smooth muscle cells incubated with human recom binant bFGF decreased the mRNA steady state levels of pro-alpha 1(1) t ype I collagen by as much as 72%, [N-3]Hydroxyproline synthesis wets a lso suppressed by 59% compared with untreated control cultures. Indire ct immunofluorescence confirmed corresponding changes at the protein l evel, lit contrast to the down-regulation of type I collagen gene expr ession, collagenase gene expression was found to be up-regulated sever alfold by bFGF. The data suggest that bFGF is capable of regulating co llagen and collagenase gene expression divergently in human smooth mus cle cells and that the effects appear to be mediated at a pretranslati onal level.