Study On The Effect Of Transplantation Of Islet-like Cells In Different Ways On Type 1 Diabetic Mice

Objective:To study the effect of transplantation of islet-like cells induced by human umbilical cord mesenchymal stem cells in different ways for the treatment of type 1 diabetic mice.Methods:1.hUC-MSCs were isolated and cultured by tissue adhere method,and its surface markers and ability to differentiate into osteocytes and adipocytes were tested;2.Four-step induction method was used to induce hUC-MSCs to differentiate into ILCs;3.Identification of ILCs:dithizone staining,C-peptide level,and relative expression levels of islet?-cell related genes Insulin and PDX1 mRNA;4.Male C57BL/6J mice were injected intraperitoneally with 55 mg/kg streptozotocin for 5 days to prepare type 1 diabetic model mice;5.The ILCs suspension(containing 5×10~5 cells)was transplanted into type 1diabetes mice by two transplantation methods:tail vein and abdominal cavity.And it divided into normal group,diabetes group,tail vein-ILCs group,abdomen-ILCs group;6.After transplantation,mice were tested for blood glucose,insulin level and glucose tolerance test in each group.Results:1.The cultured hUC-MSCs are spindle shaped and grow in a vortex.And the positive rates of surface markers CD90,CD44,CD29,CD34 and CD45 were 99.2%,99.8%,100.0%,0.0%and 0.1%,which could differentiate into osteocytes and adipocytes;2.After hUC-MSCs were induced by a four-step method,the cell morphology changed from spindle to round shape,and a large number of ILCs clusters appeared;3.ILCs were turned red-brown with dithizone staining;4.ILCs were stimulated by low and high glucose conditions,and the C-peptide expression levels were 0.528 ng/mL and 0.785 ng/mL,(P<0.05);5.The expression of Insulin and PDX1 mRNA in ILCs was significantly higher than uninduced hUC-MSCs,(P<0.001);6.Compared with the diabetic group,in the tail vein-ILCs group,the blood glucose began to significantly decrease on the 10th day after transplantation,and maintained until31 days,the insulin level and glucose tolerance improved,(P<0.05).However,there was no significant improvement in blood glucose,insulin level and glucose tolerance in the abdomen-ILCs group.Conclusion:1.HUC-MSCs were successfully cultured using tissue adhere method;2.Four-step method to induce hUC-MSCs,and successfully obtain functional ILCs;3.Tail vein transplantation of ILCs is better than intraperitoneal transplantation.