Stem cell-based approaches for the treatment of diabetes

The incidence of diabetes and the associated debilitating complications are increasing at an alarming rate worldwide. Current therapies for type 1 diabetes focus primarily on administration of exogenous insulin to help restore glucose homeostasis. However, such treatment rarely prevents the long-term complications of this serious metabolic disorder, including neuropathy, nephropathy, retinopathy, and cardiovascular disease. Whole pancreas or islet transplantations have enjoyed limited success in some individuals, but these approaches are hampered by the shortage of suitable donors and the burden of lifelong immunosuppression. Here, we review current approaches to differentiate nonislet cell types towards an islet-cell phenotype which may be used for larger-scale cell replacement strategies. In particular, the differentiation protocols used to direct embryonic stem cells, progenitor cells of both endocrine and nonendocrine origin, and induced pluripotent stem cells towards an islet-cell phenotype are discussed.