Implantation of bFGF-treated islet progenitor cells ameliorates streptozotocin-induced diabetes in rats

Aim: To examine whether implantation of islet preparation-derived proliferating islet cells (PIC) could ameliorate diabetes in rats. Methods: PIC were expanded from rat islet preparation by supplementation of basic fibroblast growth factor (bFGF) and implanted into rats with streptozotocin (STZ)-induced diabetes through the portal vein. Body weight and blood glucose levels were measured. Serum insulin levels were measured by radioimmunoassay. The presence of insulin-positive cells was determined by hematoxylin and immunohistochemical staining. Results: Cultured islet cells (CIC) were demonstrated to dedifferentiate in vitro , and the apoptosis ratios reached more than 50% by the 15th day post-isolation. PIC cells treated with bFGF (20 ng/mL) continued growing within 30 days after isolation, and no apoptotic cells were detected. Implantation of PIC into diabetic rats was capable of ameliorating diabetes, in terms of the restoration of euglycemia, weight gain, improved glucose response and elevated serum insulin levels for up to 130 days. Livers derived from PIC-implanted rats were examined for insulin expression and single insulin-positive cells. In addition, most islets of PIC-implanted STZ-induced diabetic rats were intact at 130 days post-transplantation and comparable to those of normal rats. Conclusion: Implantation of bFGF-treated proliferating islet cells is a promising cellular therapeutic approach for diabetes.