Development of Culture Conditions for the Maintenance and Expansion of Progenitor Cell Populations Along the Pancreatic Endoderm Lineage

Type I diabetes results from an autoimmune disease that attacks insulin-secreting β-cells in the pancreas. Although Type I diabetes has been treated with pancreatic beta cell transplantation, this strategy is limited by the availability of cadaverous pancreatic beta cells. Human pluripotent stem cells (hPSCs) offer a novel source of pancreatic beta cells. Significant effort has been invested in the development of protocols for the differentiation of hPSCs towards pancreatic progenitors and ultimately mature β-cells. However, to produce sufficiently large quantities of cells transplantation and drug screening studies the current shortcomings of low percentage and yield of in vitro generated insulin-expressing cells will need to be overcome. A potential strategy for generating large quantities of pancreatic progenitors required for therapeutic purposes would be to isolate, purify, and expand intermediate cell populations and subsequently guide these cells through the next stage of differentiation. Using a high-throughput microarray technology, we will screen combinations of extracellular matrix proteins, growth factors and small molecules for their ability to facilitate intermediate progenitor proliferation. These intermediates can then be characterized and sorted with qPCR and FACS. Development of conditions for maintenance and expansion of these transient cell populations will aid in differentiation of human embryonic stem cells to yield a substantial supply of pancreatic beta cells for cell therapies.