Origin of β‐cells in regenerating pancreas

The origin of insulin-expressing β-cells in the adult mammalian pancreas is controversial. During normal tissue turnover and following injury, β-cells may be replaced by duplication of existing β-cells.1 However, an alternative source of β-cells has recently been proposed based on neogenesis from a Ngn3-positive population present in regenerating pancreatic ducts.2 The appearance of β-cells from Ngn3-positive progenitors is reminiscent of normal pancreas development, and Ngn3-expressing cells isolated from regenerating pancreas can generate the full repertoire of endocrine phenotypes. The isolation and characterisation of the equivalent human progenitors may represent a significant step forward in the hunt for a cure for diabetes. BioEssays 30:617–620, 2008. © 2008 Wiley Periodicals, Inc.