Figure 5.

Effect of MAPK inhibitors on IL-1β-induced COX-2 expression. Synovial fibroblasts were pretreated with or without the MEK inhibitor U0126 (20 µM), ERK1/2 inhibitor FR180204 (50 µM), JNK inhibitor SP600125 (10 µM), and p38 inhibitor SKF86002 (10 µM) for 1 h and subsequently stimulated with IL-1β. After stimulation for 6 h or 48 h, we determined COX-2 expression (A) and prostaglandin E₂ release (B). IL-1β-induced COX-2 expression and prostaglandin E₂ release were significantly reduced by the inhibitors. Results have been represented as mean ± SE from biological triplicates. *P < 0.05.