Revascularization and transplantation effect of transfecting VEGF165 gene to islet grafts

Objective To investigate the influence of VEGF165 gene transfection on the revascularization and transplantation effect of islet grafts. Methods The rat islet cells were transfected with lentivirus containing VEGF165 gene (LV-VEGF165) in vitro, then transplanted to the renal capsule of inbred SD male rats with diabetes mellitus.Islet cells transfected with lentivirus marked with AcGFP1 and no VEGF165 gene were set as null vector control group (LV-AcGFP1 group), individual islet cells as blank control group.VEGF165 expression in vivo and in vitro was detected by ELISA.The islet grafts revascularization degree and islet cell activity were observed by immunohistochemical double staining of insulin and CD31 antibody.Blood glucose and insulin level of rats with diabetes mellitus and survival time of islet grafts were compared. Results The VEGF165 concentrations in the LV-VEGF165 group secreted by islet cells in vivo and in vitro were significantly higher than those in the LV-AcGFP1 group and the blank control group (P<0.01). Mean microvascular density (MVD) of islet grafts per square millimeter in the LV-VEGF165 group was (24.3±3.7), significantly greater than that in the LV-AcGFP1 group (12.4±2.5) and the blank control group (12.4±2.5) (P<0.01). Insulin staining intensity in the LV-VEGF165 group was also higher than that in the LV-AcGFP1 group and the blank control group.The blood glucose and insulin levels in rats with diabetes mellitus analyzed by multivariate analysis in the LV-VEGF165 group were controlled more effectively than those in the LV-AcGFP1 group and the blank control group (P<0.01). The islet grafts mean survival time (MST) after transplantation in the LV-VEGF165 group was longer than that of the LV-AcGFP1 group and the blank control group (P<0.01). Conclusion The VEGF165 gene transfection to islet cells could promote the revascularization of islet grafts and improve the effect of islet transplantation. Key words: Islet transplantation; Vascular endothelial growth factors; Transfection; Revascularization