Modulation of type I and type III collagen production in normal and mutant human skin fibroblasts by cell density, prostaglandin E2 and epidermal growth factor.

Previously, we found that, at high cell density, human skin fibroblasts produce a higher proportion of type III to type I collagen. Treatment of sparse cultures with prostaglandin E2 also increases this ratio, while treatment of dense cultures with epidermal growth factor reduces it. Similar changes were observed using some strains of fibroblasts from patients with the Ehlers-Danlos syndrome type IV and osteogenesis imperfecta. Studies on the extent of intracellular degradation suggest that the changes observed could be caused in part by changes in the breakdown of collagen inside the cell with preferential loss of type I collagen and/or changes in synthesis of the two proteins.