People with Type I diabetes have lost the insulin-secreting cells (beta-cells) from their pancreatic islets. The primary function of the four cell types comprising the pancreatic islet is to sense circulating blood glucose concentrations and release a precise amount of insulin. This insulin secretion lowers and maintains the blood glucose levels within a precise range. High and fluctuating blood glucose causes long-term damage to cells in all organs of the body. Although multiple daily insulin injections provide a patient with Type I diabetes relief from the immediate short-term effects, long-term damage to vital organs is not prevented. The need for insulin-secreting pancratic islets to treat diabetic patients far exceeds the supply of pancreas tissue available for organ or islet cell transplantation. Stemnion's objective is to use human amnion epithelial stem cells to generate a population of glucose-responsive islet-like cells. These non-embryonic cells could be used for transplantation to treat the 17 million people worldwide with Type I diabetes. The four cell types present in a pancreatic islet are derived from a common pancreatic progenitor cell during embryonic development. Preliminary results show that we have identified culture conditions and factor additives for amnion epithelial cells that support and stabilize the expression of genes important in endoderm formation (Foxa2, HNF-4, HNF-6). In the presence of additional proprietary factors and conditions, sixty per cent of the cells also express PDX1, an essential homeobox domain protein found in the earliest common pancreatic islet progenitor cells during embryonic development. The factor-mediated expression of this key regulator of pancreatic determination may indicate that we have identified differentiation conditions that generate an early pancreatic progenitor cell population from the human amnion epithelial cells. This application describes the process by which Stemnion proposes to capitalize on these preliminary results to achieve our objective. By optimizing current culture conditions, using assays designed to identify factors and additives, and co-culture of the amnion cells expressing PDX1 with differentiating mouse embryonic pancreatic explants, we plan to determine if the cells we have currently generated are capable of expressing more advanced markers of pancreatic islet cell differentiation.
Thesaurus Terms: amnion, cell differentiation, diabetes mellitus therapy, pancreatic islet, stem cell, therapy design /development biomarker, blood glucose, epithelium, gene expression, insulin, nuclear protein, pancreatic islet function, pancreatic islet transplantation, placenta, protein localization, stem cell transplantation, transcription factor athymic mouse, human tissue, immunocytochemistry, mixed tissue /cell culture, tissue /cell culture
