Figure 8.

KPR-induced HO-1 expression is mediated through p38 MAKP. (A) HPAEpiCs were pre-treated with various concentrations of p38i VIII for 1 h and then incubated with DMSO or KPR (10 μM) for 16 h. The protein expression of HO-1 was determined by Western blot using GAPDH as a loading control. (B) Cells were pretreated with or without p38i VIII (10 μM) for 1 h, and then incubated with DMSO or KPR (10 μM) for the indicated time intervals. The HO-1 mRNA expression and promoter activity were analyzed by real-time PCR (6 h) and promoter activity assay (8 h), respectively. (C) Cells were transfected with scrambled (scrb) or p38 siRNA, and then incubated with KPR (10 μM) for 16 h. The protein levels of HO-1, p38, and GAPDH were determined by Western blot. (D) Cells were transfected with p38 or PKCα siRNA, and then incubated with KPR (10 μM) for the indicated time intervals. The levels of phospho-p38, total p38, and total PKCα were determined by Western blot. Data are expressed as mean ± SEM (n = 5), analyzed with one way ANOVA and Dunnett’s post hoc test. # p < 0.01, as compared with the cells exposed to vehicle alone; or significantly different as indicated.