GLUCOCORTICOIDS NEGATIVELY REGULATE THE TRANSCRIPTION OF KC, THE MOUSE HOMOLOG OF MGSA GRO/

The KC gene is a member of the small inducible gene family of regulate d chemokines. It encodes a growth factor and chemoattractant that appe ars to mediate inflammatory and immune responses in vitro and in vivo. We now show that the transcriptional induction of KC by serum is inhi bited by glucocorticoids. The effect of glucocorticoids is dose-depend ent, requires one hour of exposure, is reversed by the protein synthes is inhibitors puromycin and cycloheximide and acts at the transcriptio nal level. The results support the hypothesis that the major anti-infl ammatory action of glucocorticoids may be to inhibit the induction of immediate-early genes that encode cytokines involved in intercellular communication. (C) 1994 Academic Press. Inc.