EFFECT OF EPIDERMAL GROWTH-FACTOR ON COLLAGEN PRODUCTION IN HUMAN GINGIVAL FIBROBLASTS

Epidermal growth factor (EGF) has been known to affect the synthesis of extracellular matrix proteins in various cells. To determine whether EGF affects the collagen production in human gingival fibroblasts, we assayed the collagen production by comparing the collagenase-digestible protein (CDP) and noncollagen protein (NCP) synthesis. EGF decreased relative collagen synthesis that was not due to the decrease of CDP synthesis but due to the increase of NCP synthesis. This effect was persisted for at least three days after EGF treatment. Alpha-1(I) procollagen mRNA level was analyzed by Northern blot hybridization. EGF decreased the steady-state level of alpha 1(I) procollagen mRNA at the concentrations which decreased percent collagen synthesis. In addition, de novo protein synthesis was not necessary for the reduction of alpha 1(I) procollagen mRNA caused by EGF. SDS-PAGE fluorography showed that the inhibition of collagen production by EGF was not due to the degradation of collagen. These results demonstrate that EGF selectively inhibits the collagen production, at least partially, by decreasing the steady-state level of procollagen mRNA and de note protein synthesis is not necessary for the effect of EGF.