Effects of VEGF on Proliferation, Apoptosis and Insulin Secretion in Rat Pancreatic Islet Cells

Objective To investigate the effect of vascular endothelial growth factor (VEGF) on proliferation, apoptosis, insulin secretion and related gene expression in rat pancreatic islet cell (INS-1). Methods INS-1 cells were treated with different concentrations of VEGF. CCK-8 kit was used to detect the proliferation of INS-1 cells and the cell apoptosis were evaluated by using AnnexinⅤ and propidium iodide (PI) double staining kit. INS-1 cells were treated with VEGF and the standard glucose stimulated insulin secretion test with ELISA was conducted. The expression of related genes in pancreatic islets was detected by real-time quantitative PCR. The effect of VEGF on isulin protein expression was evaluated with Western blot. Results No significant changes (P＞0.05) in INS-1 cells were observed after treated with different concentrations of VEGF at 24 h, 48 h and 72 h. But when VEGF concentration were 80 ng/mL and 160 ng/mL, an inhibitory effect on cell apoptosis were noticed (PSur), inwardly rectifying potassium channel gene 6.2 (Kir6.2) as well as the release of insulin were noticed as the increasing of VEGF concentrations. The expression of glucokinase gene (GCK) first decreased and then increased, but the expression of glucose transporter gene 2 (Glut2) were increased first and then decreased. Conclusion VEGF inhibited the secretion of insulin from INS-1 cells in the high-glucose condition. Our study provides new clues to the function of VEGF on the glucose metabolism.