A Comparative Histological Study on the Role of Umbilical Cord Mesenchymal Stem Cells versus Their Conditioned Medium on the Pancreatic Beta Cells in Experimentally Induced Diabetes Mellitus in Albino Rat

Abstract

Abstract Background Mesenchymal stem cells (MSCs) represent a promising population for supporting new clinical concepts in cellular therapy. Umbilical cord blood (UCB) has turned out to be an excellent alternative source of MSCs. This study had compared the role of human umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) versus their conditioned medium (CM) alone on pancreatic beta cells in a rat model of Streptozotocin (STZ)-induced type I diabetes Mellitus. Material and Methods Forty adult male albino rats were divided randomly into 4 groups; Group I (control), Group II (STZ), rats received a single dose of intraperitoneal injection of 35 mg/kg of STZ dissolved in 1 ml sodium citrate buffer. Group III (STZ + UCB-MSCs) after rats had been confirmed to be diabetic they received single dose of 1 × 106 cells /ml of UCB-MSCs into tail vein, meanwhile Group IV (STZ+ CM) rats received 0.5 ml of CM that was injected intramuscularly once per week for 4 weeks. After 4 weeks the Pancreas from all groups were dissected and stained by Hematoxylin & eosin stain and by immunohistochemical method using anti-insulin antibody to detect insulin granules in the Beta cells of the islets. Mean area percent of insulin positive reactions were measured and statistically analyzed. Results H&E-stained section of group II (STZ) showed the nuclei of the islet cells small condensed and darkly stained while, the blood capillaries were congested in endocrine pancreas.Meanwhile, Group III (STZ + UCB-MSCs) restored nearly normal histological features. Sections of Group IV (STZ+CM) showed few cells of the islets sections of showed vacuolations and small darkly stained condensed nuclei. Studying the groups immunohistochemically, revealed decrease in insulin positive reactions in Group II (STZ) while an increase in insulin positive reactions noticed in group III (STZ +UCB-MSC) and group IV (STZ+CM) when compared to group II (STZ) with more increase in group III (STZ+UCB-MSC) than group IV (STZ+CM). Conclusion It can be considered that intravenous UCB-MSCs could be more effective than CM in treatment of STZ-induced type I diabetes in the pancreas.