Differentiation Of Msenchymal Stem Cells Derived From Human Bone Marrow Into Islet β-like Cells

Objectives: To isolate mesenchymal stem cells from human bone marrow and induce them differentiate into islet β-like cells. And determine whether these islet β-like cells are able to treat type 1 diabetes.Methods: Mesenchymal stem cells were isolated from human bone marrow by hespan separating method and adhesive screening method. Then these cells were induced with epidermal growth factor (EGF), β-mercaptoethanol and high concentration of glucose. The genes' expression related to islet β cells were detected by RT-PCR. Insulin in the treated cells was examined by immunocytochemistry and immumofluorescence method. The treated cells were stained with dithizone (DTZ). In addition, the levels of insulin secretion and glucose-simulated insulin release were examined by chemiluminescence immunoassay. Finally the induced cells were implanted into the right renal subcapsular space of diabetic mice. Blood glucose levels were monitored every 2 days after implantation for 16 days. After killing the diabetic mice which received implants, the pancreas tissue and the right kidney were haversted for immunohistochemistry.Results: The untreated cells were spindle-shaped adherent cells. After induction, MSCs were getting round and formed clusters. RT-PCR showed that the treated cells expressed some genes related to islet β cells, which were strongly positive for insulin by immunocytochemistry. The induced cells were also stained into mauve by DTZ. And chemiluminescence immunoassay demonstrated that the cluster cells were able to secrete a lower level of insulin upon glucose challenge. The mice receiving the treated cells began to decrease their blood glucose levels within 4 days. And immunohistochemistry showed the implanted cells were positive for insulin. But control animals that did not receive induced cells exhibited persistent hyperglycemia.Conclusions: MSCs from human bone marrow can be induced into islet β-like cells in vitro. And these islet β-like cells can reverse hyperglycemia of type 1 diabetic mice in vivo.