INTERLEUKIN-1-BETA (IL-1-BETA) INDUCES TRANSFORMING GROWTH FACTOR-BETA(1) (TGF-BETA(1)) PRODUCTION BY RAT AORTIC SMOOTH-MUSCLE CELLS

In cultured rat aortic smooth muscle cells (RASMCs) IL-1 beta induced TGF-beta(1) mRNA expression, which was concentration (10 pM-10 nM)- an d time (2-48 h)-dependent, and sensitive to cycloheximide. The maximal increase in TGF-beta(1) mRNA was 4.5 times the basal level at 10 nM o f IL-1 beta. A parallel increase In TGF-beta(1) protein in the culture medium of IL-1 beta-stimulated RASMCs was also observed. A detectable level of TGF-beta(1) was found 8 h after stimulation and a plateau wa s reached at 72 h with a maximal increase of 5-fold and was inhibited by IL-1 receptor antagonist (IL-1ra). Our data demonstrate for the fir st time that IL-1 beta is a potent inducer of TGF-beta(1) synthesis an d release in vascular smooth muscle cells. (C) 1994 Academic Press, In c.