Pancreas and Islet Development

Abstract

The development of the pancreas and the pancreatic islets has been an area of particular scientific interest over the last several years as our attention has turned toward the possible engineering of progenitor cells and stem cells into pancreatic β cells and pancreatic islets. Pancreatic development is a highly complex process in which two morphologically distinct tissue types must derive from one simple epithelium. Although the parent endoderm from which the exocrine tissue (including acinar cells, centroacinar cells, and ducts) and the endocrine islets are derived appears to be homogeneous, it is clear that there are selected cells within the early endoderm that are destined to become either endocrine or nonendocrine lineages. The identification of these cells and the processes that determine whether or not they will become islets is of paramount importance to the engineering of stem cells into β cells. Moreover, there is a repertoire of events that allows these endocrine progenitor cells to disconnect from the epithelial lining during development. In this chapter we discuss the various key elements of basic pancreatic development. Specifically, we focus on the intercellular factors, such as growth factors, that may influence these developmental processes, as well as the important known intracellular transcription factors, which have been shown to establish a developmental hierarchy that determines lineage selection and cell fate.