The Differentiation Of Bone Marrow Mesenchymal Stem Cells Into Insulin-Producing Cells

Objective: To study culture conditions of insulin-producing cells induced in vitro by bone marrow mesenchymal stem cells (MSCs).Methods: Bone marrow (BM) was obtained from the bone of human spontaneous abortion fetus. BM cells(1×106/ml)were cultured (37℃, 5%CO2)in plastic flasks withα-MEM medium containing 10%FBS(fetal bovine serum), 48h later, total media in the culture was changed. Third or forth passages cells were used to differentiate into insulin–producing cells. First group : the cells were cultured firstly in IMDM medium containing bFGF, EGF,then cultured in IMDM containing Betacullin Activin and HGF. Second group: the cultural condition was common with the first group except the 2-mercaptoethanol is used in first or second stage respectively. Third group: the cultural condition is common with the first group too, but the rosiglitazone replaces the 2-mercaptoethanol and was added only in second stage. Negative control: undifferentiated cells. We compare the results of the different experimental group in morphology, insulin secretion and insulin protein and cell surface antigen expression.Results: MSCs attached to the surface of flasks with spindle-shaped or fibrocyte-like shape, CD44 positive (99.9%) and CD34 negative. However the differentiated MSCs are round or oval in shape, and brown color stained with dithizone. They expressed Insulin protein, and the expression of the second and the third groups are higher than the first group. The expression of insulin protein of the second group adding 2-mercaptoethanol in first stage is similar to adding rosiglitazone in second stage. Insulin secretion of the second and third group is higher than that of first group, especially adding 2-mercaptoethanol in first stage and adding rosiglitazonein in second stage.Conclusion: Our study shows that MSCs could be induced to insulin-producing cells under defined culture conditions in vitro.