Nifedipine and diazoxide attenuate PA-activated ER-stress.

<p>(A) After MIN6 cells were co-treated with nifedipine and 0.5 mM PA for 48 h, the phosphorylation of eIF2α and the expression of CHOP were detected by western blot. β-actin was used for normalization. (B) The phosphorylation rate of eIF2α was calculated as optical density of phosphorylated-eIF2α (p-eIF2α) divide by total eIF2α (t-eIF2α). * p < 0.05 denote significant difference versus the PA-treated alone group, n = 3. (C) The expression of CHOP was calculated by optical density. * p<0.05 denote significant difference versus the PA-treated alone group, n = 3. (D) After MIN6 cells were co-treated with diazoxide and 0.5 mM PA for 48 h, the phosphorylation of eIF2α, the expression of CHOP were detected by western blot. (E) The phosphorylation rate of eIF2α was calculated by optical density. * p < 0.05 denote significant difference versus the PA-treated alone group, n = 3. (F) The expression of CHOP was calculated by optical density. * p < 0.05 denote significant difference versus the PA-treated alone group, n = 3. (G) After treatment, the cells were fixed and stained with CHOP and insulin antibodies. Red fluorescence indicated CHOP expression while green marked insulin. The nuclei were stained with DAPI dye. Scale bar = 50 μm and referred to all panels.