Exendin-4 protects HUVECs from t-BHP-induced apoptosis via PI3K/Akt-Bcl-2-caspase-3 signaling

ABSTRACTAims: Although the insulinotropic role of glucagon-like peptide-1 (GLP-1) in type 2 diabetes mellitus has been substantiated, its role in cardioprotection remains largely unknown. In this study, we explored the effect and mechanism of exendin-4 on tert-butyl hydroperoxide (t-BHP)-induced apoptosis in human umbilical vein endothelial cells (HUVECs). Methods: HUVECs were treated with 100 µmol/L t-BHP for 4 h, following pretreatment with 2.5–25 nmol/L exendin-4. Cell viability was determined using an dimethyl thiazolyl diphenyl tetrazolium salt (MTT) assay. The percentage of apoptotic cells was determined by fluorescence microscopy after Hoechst/PI staining. Expression of cysteine-aspartic acid protease-3(caspase-3), beta-cell lymphoma 2(Bcl-2), protein kinase B(AKT), and phosphorylated AKT was detected by western blotting. Results: Exendin-4 reduced the percentage of cells undergoing apoptosis when HUVECs were exposed to t-BHP. Exendin-4 downregulated caspase-3 activity and increased Bcl-2 protein l...