Effect of mesenchymal stem cell therapy on recovery of streptozotocin-induced diabetes mellitus in adult male albino rats: a histological and immunohistochemical study

Introduction:Type I diabetes is characterized by the deficiency of endocrine β cells in the pancreatic islets of Langerhans. Stem cell therapy can be an effective therapeutic approach. Aim of the work:The present study was carried out to investigate the therapeutic effect of mesenchymal stem cells (MSCs) in the recovery of streptozotocin (STZ)-induced diabetes mellitus in the pancreas of adult male albino rats. Materials and methods:Thirty-five adult male albino rats were divided into three groups. Group I served as the control group. In group II, diabetes was induced by a single intraperitoneal injection of STZ at a dose of 60 mg/kg body weight. In Group III, diabetes was induced; the rats then received MSC therapy and were sacrificed after 1 week (subgroup IIIa) and at 4 weeks (subgroup IIIb). The mean blood glucose levels were measured for all groups. Pancreatic sections were subjected to the following staining procedures: H E, MSC marker CD44, and insulin immunostaining. The mean number of CD44- immunopositive cells and the mean area % of insulin-immunopositive cells were measured using image analysis. Results were statistically compared. Results: In group II, cells located mainly in the central part of the islets showed marked swelling and a vacuolated and degenerated cytoplasm. Peripheral islet infiltration by lymphocytes was observed. Treatment of the diabetic group with MSCs for the longer duration (4 weeks) caused restoration of the normal pancreatic architecture. There was a significant increase in the number of CD44 cells after MSC therapy compared with the control and diabetic groups. Mean area % of insulin-positive cells presented a significant decrease in the diabetic group, followed by progressive increase after MSC therapy. Conclusion:Treatment with MSCs promoted pancreatic islet regeneration in STZ-induced diabetic rats, suggesting its potential use as a therapeutic modality for diabetes mellitus.