Molecular Biology Studies on Using Stem Cells and Ionizing γ-Radiation for Treating Pancreatic Damage Induced by Alloxan

Abstract

Diabetes mellitus is a metabolic disorder of various etiology recognized by chronic hyperglycaemia with disturbance in the metabolism of carbohydrate, fat and protein due to insulin secretion deficiency, defects in insulin activity, or both. The impacts of diabetes mellitus incorporate long–term damage, impairment and failure of different organs. Mesenchymal stem cells (MSCs) obtained from the bone marrow are multipotent stromal cells, which can give a potential treatment for diabetes mellitus. MSCs transplantation has been shown to decrease blood glucose level in diabetic rats. Upon transplantation, these cells start endogenous pancreatic regeneration by neogenesis of langerhans islets of the recipient rats. Many recent studies have focused on strategies to induce β cell development from rat or human bone marrow stem cells. The present study was carried out in order to assay the differentiation ability of adult rat bone marrow mesenchymal stem cells to form insulin-producing cells and their prospected potential in treatment of alloxan induced-diabetes in rats. Moreover, to compare the curative effect of stem cell therapy using bone marrow MSCs expanded in vitro with the curative effect of differentiated beta cell expanded in vitro for regenerating damaged islets of Langerhans. In addition, to examine whether immunosuppression by ionizing radiation exposure prior to the treatment with stem cell could provide better cell therapy. MSCs were obtained from bone marrow of male albino rats and expanded then characterized using flowcytometry. Some MSCs induced in vitro to form pancreatic cells, after that cells differentiation was assured using RT-PCR. Diabetes was induced in female albino rats by alloxan intraperitoneal injection at a dose of 120 mg/kg body weight. After stable hyperglycemia level was achieved the diabetic rats were injected with 5×106 undifferentiated MSCs or 5×106 early differentiated pancreatic cells into the tail vein. Diabetic rats were also exposed to 6 Gy whole body gamma irradiation 24 hours prior to cells injection either with undifferentiated MSCs or early differentiated pancreatic cells. Laboratory investigations were focused over molecular