Bone marrow mesenchymal stem cells (BMSCs) have the ability of self-renewaland multi-directional differentiation. Recent reports showed that BMSCs could differentiate intoendocrine cells of pancreas. However, the differentiation is not efficient enough to produceinsulin-producing cells for the future therapeutic use. Pdx-1 is a crucial regulator for pancreaticdevelopment. Therefore we constructed a eukaryotic expression vector containing Pdx-1 to determinethe effect of Pdx-1 expression on differentiation of BMSCs in vitro. The results showed that BMSCscould self-assemble to form functional pancreatic islet-like structures after differentiation invitro. The proportion of insulin-producing cells differentiated from Pdx-1 +BMSCs was 28.23%+-2.56%,higher than that from BMSCs transfected with vacant vector and Pdx-1'' BMSCs (7.23%+-1.56% and4.08%+-2.69% respectively) by flow cytometry. Immunocytochemical examination also testified theexpression of multiple bate-cells-specific genes such as insulin, glucagons, somatostatin indifferentiated BMSCs. The results also revealed that the expressions of genes mentioned above inPdx-1+BMSCs were higher than that in Pdx-VBMSCs, which was confirmed by Western blotting analysisand RT-PCR. Glucose-inducedinsulin secretion from Pdx-1+BMSCs in 5mmol/L and 25mmol/L glocuse was(56.61 +-4.82) uU/ml and (115.29+-2.56) uU/ml respectively, which were much higher than those fromPdx-1 BMSCs((25.53 +-6.49) uU/mL and (53.26 + 7.56) uU/mL respectively). Grafted animals were ableto maintain their body weight and survive for relatively longer periods of time than hyperglycemicsham-grafted controls, which demonstrated an overall beneficial effect of the grafted cells on thehealth of the animals. These findings thus suggested that exogenous expression of Pdx-1 shouldprovide a promising approach for efficiently producing islet-like cells from BMSCs for the futuretherapeutic use in diabetic patients.
SUN Jiping1,YANG Yujia1,WANG Xiaoli1,SONG Jianhui1 & JIA Yanjie2 1.Department of Pediatrics,Xiang-Ya Hospital,Central-South University,Changsha 410008,China
