Endothelial cells promote islet survival and function

Objective: To investigate islet graft survival and function after co-culture and co-transplantation with vascular endothelial cells ECs in diabetic rats. Methods: We isolated ECs, and assessed the viability of isolated islets in a group of standard culture and a group of co-culture with ECs. Then we put the diabetic rats in 4 groups: an islet transplantation group, an islet graft with EC transplantation group, an EC transplantation group, and a PBS control group. Blood glucose and insulin concentrations were measured daily. Cell morphology and cell markers were investigated by immunohistochemical staining and electron microscope. Results: Normal morphology was shown in more than 90% of AO/PI staining positive islets while co-cultured with ECs for 7 days. Insulin release assays showed a significantly higher simulation index co-culture except for the first day (P<0.05). There was a significant difference in concentrations of blood glucose and insulin among the 4 groups after 3 days after the transplantation (P<0.05). Conclusion: EC-islet co-culture can improve the function and survival of isolated islets in vitro, and EC-islet co-transplantation can effectively prolong the islet graft survival in diabetic rats.