Toward a cell-based cure for diabetes: Advances in production and transplant of beta cells

Type 1 diabetes results from autoimmune destruction of the insulin-liroducili(I beta cells of the pancreatic islets of Langerhans. Although developments in exogenous insulin therapy have greatly improved clinical outcomes in patients with diabetes, the ability of the pancreatic beta cell to exquisitely regulate the delivery of insulin and maintain normal levels of blood glucose is still far superior to what can he achived by external delivery of insulin. As a result, the majority of patients wit type 1 diabetes still experience the complications of chronic hyperglycemia or serious and potentially life-threatening hypoglycemia. The shortcomings of medical therapy have driven research toward more direct approaches of beta cell replacement. Indeed, the specificity of heal cell loss in tyke 7 diabetes makes this disease a particularly attractive candidate for cell-based therapies. In order for significant progress to he made, however, a thorough under-standing of beta cell biology and more broadly islet biology is necessary. This review addresses recent advances in developmental biology that have expanded our understanding,; of islet cell differentiation, :assesses the promise and limitations of islet transplantation, and discusses the future of alternative sources of beta cells, including directed differentiation of stem cells, replication of adult beta cells, and transdifferentiation of nonislet cells to, beta cell fate.