OBJECTIVETo investigate the differential potential of mesenchymal stem cells (MSCs) derived from human umbilical cord blood (hUCB) into insulin-secreting cells and its inducing condition.

METHODSUCB nucleated cells (NCs) were isolated and cultured in Mesencult media. The obtained UCB MSC were purified by adherence method and expanded. Then they were induced with epidermal growth factor (EGF), B-mercaptoethanol and high concentration of glucose. The induced cells were identified by RT-PCR. Intracellular insulin was examined by immunocytochemistry. The quantity of insulin secretion and glucose-simulated insulin release were examined by chemiluminescence immunoassay. The induced cells were also transplanted into renal subcapsular space of STZ-induced hyperglycemic mice to observe the in vivo lowering effect on hyperglycemia.

RESULTSThe induced cells morphologically became round and were gathering into a mass. The expression of some genes related to pancreatic islet was found by RT-PCR. Chemiluminescence immunoassay showed insulin positivity and the cells secreted a low concentration of insulin [(0.37 +/- 0.06) mU/L]. The induced cells responded to high glucose challenge with a stimulation index of 1.76. After those cells grafted into renal sub-capsule there was an in vivo lowering effect on blood glucose level on STZ hyperglycemic mice.

CONCLUSIONMSCs from UCB can differentiated into insulin secreting cells.