Figure 3.

Effects of MAPKs in thrombin-induced COX-2 expression. (A) Cells were pretreated with SB202190, U0126, or SP600125 for 1 h and then incubated with thrombin for 16 h. The COX-2 protein expression was determined by Western blot. (B) Cells were pretreated with SB202190 (1 μM), U0126 (10 μM) or SP600125 (10 μM) for 1 h and then incubated with thrombin for 4 h. The COX-2 mRNA and promoter luciferase activity were detected. (C) Cells were pretreated with SB202190 (1 μM), U0126 (10 μM) or SP600125 (10 μM) for 1 h and then challenged with thrombin (3 U·mL⁻¹) for the indicated time intervals. The cell lysates were analysed by Western blot using an anti-phospho-p38, anti-phospho-Erk1/2, anti-phospho-JNK1/2 or anti-GAPDH (as an internal control) antibody. (D) Cells were transfected with siRNA for scramble (scr), p38, p42 (Erk2) or JNK2 and then incubated with thrombin for 16 h. The COX-2 protein expression was determined by Western blot. (E) Cells were pretreated with SB202190 (1 μM), U0126 (1 μM) or SP600125 (10 μM) for 1 h and then incubated with thrombin for 16 h. The conditioned media were collected for PGE₂ generation analysed by an EIA kit. Data were expressed as mean ± SEM (n = 3). *P < 0.05; ^#P < 0.01, significantly different from thrombin alone.