[Effect of cortisol on glycosaminoglycan synthesis and growth of diploid, human fibroblasts (WI-38) in relation to in vitro aging]

Abstract

Addition of cortisol (hydrocortisone; 1.4 X 10(-7) M) to the culture medium (BME with non-essential amino acids and 10% fetal calf serum) of human fibroblasts resulted in increased proliferative activity--in regard to cell number and incorporation rates of [3H]-thymidine into DNA and [14C]-leucine into protein--and in an increased saturation density. Glycosaminoglycan (GAG) synthesis rates (as measured by incorporation of [14C]-glucosamine or [35S]-sulfate) of the various GAG types secreted into the culture medium (hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparan sulfate) were evenly inhibited by ca. 25% in the case of cortisol-treated Phase-II cultures. The dose-effect relationship revealed a median effective cortisol dose of ca. 0.01 microM for Phase-II cultures. Phase-III ("senescent") cultures revealed an elevated sensitivity as well in regard to cortisol concentration as to the extent of the inhibitory effect. Contrary to the medium GAGs, the pattern of the cell-bound GAGs was changed by cortisol (1.4 X 10(-7) M), with an increase of hyaluronic acid synthesis and a decrease of the sulfated GAGs. This cell-bound hyaluronic acid was predominantly removable by trypsin-treatment and therefore regarded to be localized at the cell surface or pericellularly. Also, following long-term cultivation (ca. 15 population-doublings) in the presence of cortisol, the synthesis of cell-bound hyaluronic acid was stimulated. Since cellular hyaluronic acid decreases during senescence of WI-38 cultures (Sluke et al., 1981), the cortisol effect in regard to GAG synthesis is in line with a "counter-aging" influence.(ABSTRACT TRUNCATED AT 250 WORDS)