Fig. 5

Addition of exogenous oleic acid rescued ER stress-mediated apoptosis triggered by SCD1 inhibition. (A) PA-1 cells were treated with CAY10566 (20 nM) with oleic acid-BSA (10 mM) or fatty acid-free BSA (10 µM) as vehicle control for 48 h. Cell viability was analyzed by MTT assay. Results were presented as the percentage of total cell number compared to DMSO-treated control. (B) PA-1 cells were treated with CAY10566 (20 nM) with or without oleic acid-BSA (10 µM) for 48 h. The percentage of apoptotic cells was calculated by flow cytometry analysis using Annexin V-FITC and PI staining. (C) Inhibition of CAY10566-mediated PARP and caspase-3 cleavage by supplementation with oleic acid. PA-1 cells were treated with CAY10566 (20 nM) with or without oleic acid-BSA (10 mM) for 48 h. The expression levels of cleaved PARP and caspase-3 were assessed by western blot analysis. GAPDH was used as a loading control. (D) PA-1 cells were treated with CAY10566 (20 nM) with or without oleic acid-BSA (10 µM) for 48 h. The expression levels of P-PERK, IRE1α, ATF4, and CHOP were determined by western blot analysis. GAPDH was used as a loading control. All data were described as mean ± SEM of three independent experiments (*p < 0.05; **p < 0.01; ***p < 0.001)