Impact of different pancreatic microenvironments on improvement in hyperglycemia and insulin deficiency in diabetic rats after transplantation of allogeneic mesenchymal stromal cells

Abstract Background Mesenchymal stromal cells (MSCs) in the pancreatic microenvironment can improve diabetes mellitus (DM). The aim of the present study was to determine whether different pancreatic microenvironments influence the improvement of hyperglycemia and insulin deficiency. Methods MSCs isolated from rat bone marrow were transplanted directly into different pancreatic microenvironments in male DM rats. DM was induced in the rats by streptozotocin injection. The rats were divided into 5 groups: normal control rats, DM control rats, and 3 experimental groups (DM rats plus MSCs injected into the head of the pancreas, the tail of the pancreas, or the whole pancreas). The body weight and blood glucose of the rats were monitored during the experiment after transplantation of the MSCs. Histopathologic and immunohistochemical analyses were used to detect the presence and number of islets and insulin production in the pancreatic tissue of the rats after MSC transplantation. Results At 28 days after MSC transplantation, we observed a statistically significant decrease in the blood glucose level and an increase in weight in DM rats compared with DM control rats ( P < 0.0001 and P < 0.03, respectively). A comparison of each of the DM rat groups treated with MSCs showed no significant differences in the blood glucose levels or body weight. Conclusion Our results suggest that transplantation of MSCs could improve DM in the pancreatic microenvironment in an animal model with streptozotocin-induced DM. The different pancreatic areas into which the MSCs were implanted had no significant influence on the improvement in hyperglycemia and insulin deficiency.