No evidence for β cell neogenesis in murine adult pancreas
Xiangwei Xiao, … , John Wiersch, George K. Gittes
Xiangwei Xiao, … , John Wiersch, George K. Gittes
Published April 24, 2013
Citation Information: J Clin Invest. 2013;123(5):2207-2217. https://doi.org/10.1172/JCI66323.
View: Text | PDF
Research Article

No evidence for β cell neogenesis in murine adult pancreas

Abstract

Whether facultative β cell progenitors exist in the adult pancreas is a major unsolved question. To date, lineage-tracing studies have provided conflicting results. To track β cell neogenesis in vivo, we generated transgenic mice that transiently coexpress mTomato and GFP in a time-sensitive, nonconditional Cre-mediated manner, so that insulin-producing cells express GFP under control of the insulin promoter, while all other cells express mTomato (INSCremTmG mice). Newly differentiated β cells were detected by flow cytometry and fluorescence microscopy, taking advantage of their transient coexpression of GFP and mTomato fluorescent proteins. We found that β cell neogenesis predominantly occurs during embryogenesis, decreases dramatically shortly after birth, and is completely absent in adults across various models of β cell loss, β cell growth and regeneration, and inflammation. Moreover, we demonstrated upregulation of neurogenin 3 (NGN3) in both proliferating ducts and preexisting β cells in the ligated pancreatic tail after pancreatic ductal ligation. These results are consistent with some recent reports, but argue against the widely held belief that NGN3 marks cells undergoing endocrine neogenesis in the pancreas. Our data suggest that β cell neogenesis in the adult pancreas occurs rarely, if ever, under either normal or pathological conditions.

Authors

Xiangwei Xiao, Zean Chen, Chiyo Shiota, Krishna Prasadan, Ping Guo, Yousef El-Gohary, Jose Paredes, Carey Welsh, John Wiersch, George K. Gittes

×

Figure 2

Validation of the INSCremTmG model.

Options: View larger image (or click on image) Download as PowerPoint
Validation of the INSCremTmG model. (A) Confocal images of INSCremTmG ...
(A) Confocal images of INSCremTmG pancreatic sections show exclusively yellow cells (no green mT–mG+ cells) at E13.5 and E14.5, but both yellow (arrows) and green cells (arrowhead) are visible at E15.5. Inset shows a representative yellow cell at high magnification. (B) Percentages of yellow cells of the total yellow and green cells were quantified at embryonic and early postnatal stages by microscopy, which shows that the initial detection of green cells is approximately 2 days after the initial detection of yellow cells (E15.5 versus E13.5). Yellow cell percentages continuously decreased with time and became undetectable after P5. (C) FACS of E15.5 INSCremTmG pancreatic digests. Red, yellow, and green cell populations are circled red, yellow, and green, respectively, for analysis and sorting. (D) Yellow cells isolated from pooled E16.5 mouse pancreata were cultured. While some cells were reanalyzed immediately by FACS to ensure the absence of red cells, other cells were analyzed at different culture time points. Cultured yellow cells gradually shifted their color to green with time. While a small number of yellow cells could still be detected after 40 hours, none were detected after 48 hours, suggesting that the detection window for yellow cells is 40–48 hours. (E) Gene expression of the red, green, and yellow cells from E15.5 pancreas was analyzed by qPCR. Ngn3 mRNA levels in yellow and green cells are more than 180-fold lower than in red cells. All experiments were performed 5 times. Scale bars: 20 μm.