S1P induces ICAM-1 expression via AP-1.

<p>(A) HPAEpiCs were pretreated with Tanshinone IIA 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 Tanshinone IIA (100 nM) 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 Tanshinone IIA (100 nM) for 1 h, and then incubated with S1P for 16 h. The THP-1 cells adherence was measured. (D) Cells were treated with S1P for the indicated time intervals. The mRNA levels of c-Jun and c-Fos were determined by real-time PCR. (E) Cells were transfected with siRNA of scrambled, c-Jun, or c-Fos, and then incubated with S1P (10 μM) for 16 h. The levels of c-Fos, c-Jun, and ICAM-1 proteins were determined by Western blot. (F) Cells were pretreated without or with PP1, AG1296, AG1478, U0126, SP600125, SB202190, or U0126 for 1 h, and then incubated with S1P for the indicated time intervals. The levels of phospho-c-Jun were determined by Western blot. Data are expressed as mean (A, E) or mean±S.E.M. of three independent experiments. ^#<i>P</i><0.01, as compared with the cells exposed to S1P alone (A-C), vehicle alone (D), or transfected with siRNA of scrambled+S1P (E).