Effect of human umbilical cord-derived mesenchymal stem cells on type 2 diabetic rats and its mechanism

Objective To observe the effect of human umbilical cord-derived mesenchymal stem cells(hMSCs)on type 2 diabetic rats, and to explore the possible mechanism. Methods Type 2 diabetic rats were induced by high-fat diet combined with a low dosage of streptozotocin(STZ, 25 mg/kg). After 3×106hMSCs suspended in 1 ml PBS or 1ml 10-fold concentrated hMSC supernatant were intravenously infused into the rats via the tail vein, the blood glucose levels were measured every day. One week later, intraperitoneal glucose tolerance test and insulin tolerance test were performed to evaluate the effects of hMSCs on diabetic rats. Pancreatic tissues were collected for insulin/glucagon immunofluorescence staining. Results After hMSCs infusion, blood glucose level and homeostasis model of assessment for insulin resistance index were significantly decreased in type 2 diabetic rats(both P<0.01). The glucose tolerance and insulin tolerance were greatly alleviated by hMSCs(all P<0.01). Intravenously infused 1ml 10-fold concentrated hMSC supernatant showed a similar result to hMSCs. Conclusion In type 2 diabetic rats, hMSCs are able to effectively lower the blood glucose level, improve insulin sensitivity, and increase the number of β cells, which seems to be mediated by their secreted molecules. (Chin J Endocrinol Metab, 2017, 33: 62-67) Key words: Mesenchymal stem cells; Diabetes mellitus; Insulin resistance; Insulin-secreting cells