Figure 4
LPS induces VCAM-1 expression via ROS/p38 MAPK. (A) Cells were pretreated with SB202190, U0126, or SP600125, and then incubated with LPS for 8 h. VCAM-1 protein levels were determined. (B) Cells were pretreated with SB202190, U0126, or SP600125, and then incubated with LPS for 4 h or 6 h. mRNA levels and promoter activity of VCAM-1 were determined. (C) Cells were treated with LPS for the indicated times or transfected with siRNA of c-Src, p47phox, or p38 MAPK, and then treated with LPS for 1 h. Phospho-p38 MAPK expression was determined. (D) Cells were treated with LPS for the indicated times or pretreated with edaravone (Eda, 100 μM), PP1 (1 μM), or U0126 (U0, 1 μM), and then treated with LPS for 5 min. Phospho-p42/p44 MAPK expression was determined. (E) Cells were treated with LPS for the indicated times or pretreated with edaravone (Eda), PP1, or SP600125 (SP), and then treated with LPS for 1 h. The expression of phospho-JNK1/2 was determined. (F) Cells were transfected with p38 MAPK siRNA, and then incubated with LPS for 8 h. Protein levels of p38 MAPK and VCAM-1 were determined. All figures are representative of three independent experiments, performed in duplicate. Data are expressed as means ± SEM. *P < 0.05; #P < 0.01, as compared with the cells exposed to LPS alone (A, B, lower panels of D and E), vehicle alone (upper panels of C, D, E), scrambled siRNA alone (F, upper panel), or LPS + scrambled siRNA (lower panels of C and F).