Fibroblast Responses to Cytokines Are Maintained During Aging

Abstract

Impaired wound healing in older individuals may result from a global deficit of fibroblast activity or a decreased response of aged fibroblasts to stimulation by inflammatory cytokines. Twentyeight fibroblast cell strains were developed from normal human skin aged 3 days to 84 years. Mitogenic response to cytokines, epidermal growth factor, tumor necrosis factor-alpha, plateletderived growth factor or fetal bovine serum was determined using a 4-hour 3H-thymidine incorporation assay. Synthesis of collagen and noncollagen proteins was determined basally and in response to transforming growth factor-beta using a 6-hour 3H-proline incorporation assay. Neither the mitogenic response to cytokine stimulation (p