Effects of palmitate on ER stress and apoptotic signaling pathways.

RAW264.7 cells were treated with various concentrations (μmol/L) of palmitate (Black bar) or corresponding amount of BSA (White bar) for 16 hours. Western blot analyses for Phospho (P)-PERK (A), CHOP (B), Phospho (P)-JNK (C), cleaved caspase-3 (D) were performed. (E) The effect of palmitoleate on PERK phosphorylation was compared with that of palmitate in RAW264.7 cells. The bar graphs indicate the ratio of P-PERK to PERK, CHOP to α-tubulin, P-JNK to JNK, and cleaved caspase-3 to α-tubulin, respectively. *P<0.05, ** P<0.01 vs control. n = 4. (F) The effect of palmitate on PERK phosphorylation was examined in peritoneal macrophages. The effects of pioglitazone and SCD-1 inhibitor were also examined. **p<0.01 vs control (palmitate (-), pioglitazone (-)), ##P<0.01 vs palmitate, ††P<0.01 vs Palmitate+Pioglitazone. n = 4.