Pancreatic islets: new discoveries for innovative treatments of diabetes?

Pancreatic beta cells are dedicated factories in the production, storage and secretion of impressive amounts of insulin. In the human pancreas, beta cells are found in clusters known as islets of Langerhans which vary in cell quantity and endocrine cell types, including glucagon-producing alpha cells and somatostatin-producing delta cells. Major progress has been made in recent years in understanding beta cell physiology and pathology, with a particular focus on the mechanisms of beta cell destruction in type 1 diabetes and potential approaches for restoring beta cell function. In this review, we have selected recent examples that highlight the progress made in understanding human islets and beta cell biology. Specifically, we (1) concentrated on new discoveries in beta cells, both within and outside of the islets of Langerhans; (2) evaluated whether more understanding of basic beta cell biology is needed; (3) discussed whether more tools are needed to provide answers to our key questions; as an example, we highlighted the progress made in the development of human beta cell lines and in the imaging tools for studying human beta cells; (4) questioned why there is still a gap in knowledge regarding beta cell destruction in type 1 diabetes, despite hundreds of thousands of published studies. We conclude with our vision of beta and islet cell biology.