Improved differentiation protocol of rat bone marrow precursors to functional islet like cells

Directional transdifferentiation of bone marrow precursor cells assumes beta cell like properties in modified tissue microenvironment. The factors that modify the roles of precursor cells to functional beta cells enabling precise, defined and efficient in vitro differentiation protocols are yet to be conclusive. The study aims at the determination of appropriate induction factors that may aid the robust, reproducible transdifferentiation of rat bone marrow derived mesenchymal stem cells (MSCs) to islet-like cells and enhance their transdifferentiation efficiency. High glucose concentration including nicotinamide, β-mercaptoethanol along with β-cellulin, IGF-1 were able to induce bone marrow precursor cells to islet like clusters ex vivo consistently. The four step induction protocol has enhanced the expression of pancreatic islet cell specific transcription and translational factors detectable by immunocytochemistry viz., pro-insulin, glucagon, somatostatin and polypeptide. The functionality was assessed by the glucose challenge assay followed by animal experiment. The streptozotocin (STZ) induced rats demonstrated significant reduction in glucose levels post islet like cell transplantation (P<0.05). The tropic and the growth factors thus used have a profound impact on the induction of the bone marrow precursors to functional islet like cells.