S1P induces ICAM-1 expression via MAPKs.

<p>(A) HPAEpiCs were pretreated with U0126, SB202190, or SP600125 for 1 h, and then incubated with S1P for 16 h. The ICAM-1 protein expression was determined by Western blot. (B) Cells were pretreated with SB202190 (10 M), U0126 (1 μM), or SP600125 (10 M) for 1 h, and then incubated with S1P for 4 h. The ICAM-1 mRNA expression and promoter activity were determined by real-time PCR and promoter assay, respectively. (C) Cells were pretreated with SB202190 (10 M), U0126 (1 μM), or SP600125 (10 M) for 1 h, and then incubated with S1P for 16 h. The THP-1 cells adherence was measured. (D) Cells were transfected with siRNA of scrambled, p38, p42, or JNK1, and then incubated with S1P (10 μM) for 16 h. The levels of p38, p42, JNK1, and ICAM-1 proteins were determined by Western blot. (E) Cells were pretreated without or with U0126 (1 μM), SB202190 (10 M), or SP600125 (10 M) for 1 h, and then incubated with S1P (10 M) for the indicated time intervals. The levels of phospho-p42/p44 MAPK, phospho-p38 MAPK, and phospho-JNK1/2 were determined by Western blot. Data are expressed as mean (A, D) or mean±S.E.M (B, C) of three independent experiments. *<i>P</i><0.05; ^#<i>P</i><0.01, as compared with the cells exposed to S1P alone (A, B, C) or transfected with siRNA of scrambled+S1P (D).