Modulation of urokinase‐type plasminogen activator messenger rna levels in human synovial fibroblasts by interleukin‐1, retinoic acid, and a glucocorticoid

Abstract

Previous studies have shown that mononuclear cell–conditioned medium (MCCM), interleukin-1 (IL-1), and all-trans-retinoic acid rapidly stimulate, while glucocorticoids lower, the urokinase-type plasminogen activator (u-PA) activity of human synovial fibroblastlike cells. It is now reported that MCCM, recombinant human IL-1α (rHuIL-1α), rHuIL-1β, and all-trans-retinoic acid elevate the u-PA messenger RNA (mRNA) levels to a steady-state value within 2 hours, while dexamethasone (10⁻⁷M) inhibits this increase. For both situations, when the u-PA activity is either stimulated or reduced, the changes in the u-PA mRNA levels parallel the changes in the u-PA activity, and it is suggested that modulation of gene transcription plays an important role.