Pancreatic β Cell Dedifferentiation as a Mechanism of Diabetic β Cell Failure

SummaryDiabetes is associated with β cell failure. But it remains unclear whether the latter results from reduced β cell number or function. FoxO1 integrates β cell proliferation with adaptive β cell function. We interrogated the contribution of these two processes to β cell dysfunction, using mice lacking FoxO1 in β cells. FoxO1 ablation caused hyperglycemia with reduced β cell mass following physiologic stress, such as multiparity and aging. Surprisingly, lineage-tracing experiments demonstrated that loss of β cell mass was due to β cell dedifferentiation, not death. Dedifferentiated β cells reverted to progenitor-like cells expressing Neurogenin3, Oct4, Nanog, and L-Myc. A subset of FoxO1-deficient β cells adopted the α cell fate, resulting in hyperglucagonemia. Strikingly, we identify the same sequence of events as a feature of different models of murine diabetes. We propose that dedifferentiation trumps endocrine cell death in the natural history of β cell failure and suggest that treatment of β cell dysfunction should restore differentiation, rather than promoting β cell replication.PaperFlick To view the video inline, enable JavaScript on your browser. However, you can download and view the video by clicking on the icon belowHelp with MP4 filesOptionsDownload video (12191 K)

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (227 K)Download as PowerPoint slideHighlights► Dedifferentiation, not apoptosis, is the main cause of β cell failure ► FoxO1 enforces the β cell fate during β cell adaptation to metabolic stress ► Dedifferentiated β cells are prone to converting into α, δ, and Pp endocrine cells