Figure 2

p38 MAPK pathway is required for resistin-stimulated SDF-1 expression. (A) TSGH 9201 cells were incubated with various concentrations of the specific MEK1 inhibitor PD98059 (PD, 10 μM), the c-Jun N-Terminal Kinase (JNK/SAP Kinase) Inhibitors SP600125 (SP, 10 μM), or the p38 Inhibitor SB 203580 (SB, 10 μM) for 1 h, transfected with control siRNA (si-CL), control pcDNA3 vector (vec), or a specific siRNA of si-ERK, si-JNK, or si-p38. Next, the cells were treated with 25 ng/mL resistin for 4 h (B) or 6 h (C). (B) All bar graphs represent folds of CL group and normalized to 18S rRNA. (C) Human SDF-1 secretion was determined by ELISA. The results are shown as mean ± SEM. *P < 0.05 versus CL. #P < 0.05 versus vehicle control (DMSO) or control siRNA (si-CL) with resistin stimulation. (D) Total cell lysates of cells treated with or without resistin for the indicated time were extracted, and the phosphorylated proteins of p38 MAPK, and p38 MARK were immunodetected as described in “Materials and Methods”. Protein levels were quantified by densitometric analysis, with the control being set at 100%.