Fig. 4

IL-17A enhanced COX2 and PGE2 expression was associated with increased p38 and JNK signaling. NP cells were cultured in serum-free medium prior to treatment with SB203580 (10 or 20 μM; p38 MAPK phosphorylation inhibitor), SP600125 (10 or 20 μM; JNK MAPK phosphorylation inhibitor), or PD98059 (20 or 30 μM; ERK1/2 MAPK phosphorylation inhibitor) for 30 min prior to the addition of IL-17A (100 ng/ml) for 24 h. The cell lysates were prepared for western blot of COX2 and cell-free supernatants were harvested for ELISA of PGE2. Pretreatment with SB203580 (10 or 20 μM), SP600125 (10 or 20 μM) for 30 min prior to IL-17A induction for 24 h in NP cells significantly declined the expression of COX2 (a, b) and PGE2 (d, e) compared with IL-17A-only treatment (*P < 0.01, vs. control; ^#P < 0.001, vs. IL-17-only treatment). However, the levels of COX2 (c) and PGE2 (f) were with no significant difference in the presence of PD98059 (20 or 30 μM) after IL-17A-induced MAPK stimulation (*P < 0.01, vs. control)