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 modula..