Pancreas-specific deletion of mouse Gata4 and Gata6 causes pancreatic agenesis
Shouhong Xuan, … , Raymond J. Macdonald, Lori Sussel
Shouhong Xuan, … , Raymond J. Macdonald, Lori Sussel
Published September 24, 2012
Citation Information: J Clin Invest. 2012;122(10):3516-3528. https://doi.org/10.1172/JCI63352.
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Research Article

Pancreas-specific deletion of mouse Gata4 and Gata6 causes pancreatic agenesis

Abstract

Pancreatic agenesis is a human disorder caused by defects in pancreas development. To date, only a few genes have been linked to pancreatic agenesis in humans, with mutations in pancreatic and duodenal homeobox 1 (PDX1) and pancreas-specific transcription factor 1a (PTF1A) reported in only 5 families with described cases. Recently, mutations in GATA6 have been identified in a large percentage of human cases, and a GATA4 mutant allele has been implicated in a single case. In the mouse, Gata4 and Gata6 are expressed in several endoderm-derived tissues, including the pancreas. To analyze the functions of GATA4 and/or GATA6 during mouse pancreatic development, we generated pancreas-specific deletions of Gata4 and Gata6. Surprisingly, loss of either Gata4 or Gata6 in the pancreas resulted in only mild pancreatic defects, which resolved postnatally. However, simultaneous deletion of both Gata4 and Gata6 in the pancreas caused severe pancreatic agenesis due to disruption of pancreatic progenitor cell proliferation, defects in branching morphogenesis, and a subsequent failure to induce the differentiation of progenitor cells expressing carboxypeptidase A1 (CPA1) and neurogenin 3 (NEUROG3). These studies address the conserved and nonconserved mechanisms underlying GATA4 and GATA6 function during pancreas development and provide a new mouse model to characterize the underlying developmental defects associated with pancreatic agenesis.

Authors

Shouhong Xuan, Matthew J. Borok, Kimberly J. Decker, Michele A. Battle, Stephen A. Duncan, Michael A. Hale, Raymond J. Macdonald, Lori Sussel

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Figure 6

Morphological and molecular defects in DKO pancreas are apparent during secondary transition.

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Morphological and molecular defects in DKO pancreas are apparent during ...
(A and B) Whole-mount LacZ lineage labeling of Pdx1 progeny in control (A) versus DKO (B) embryos indicates that by E11.5, the DKO embryos have smaller pancreatic buds. (C and D) Coimmunofluorescence staining of caspase 3 (red) and Pdx1 (green) in E11.5 sections of control (C) vs. DKO embryos (D) suggests that there is no obvious change in apoptosis in the DKO pancreas. Insets show positively caspase 3–labeled tissue from the same sections. (E and F) Coimmunofluorescence staining of BrdU (red) and Pdx1 (green) in E11.5 sections of control (E) vs. DKO embryos (F) indicates there are fewer proliferating Pdx1+ pancreatic cells. (G) Quantification of BrdU-labeled Pdx1+ cells indicates a significant (28%) reduction in the number of replicating Pdx1+ progenitor cells in DKO embryos. (H) FACS analysis of PI-stained cells to quantify overall cellular proliferation shows significant (38%) reduction of S phase cells in the DKO pancreatic buds. (I and J) Immunofluorescence staining of Sox9 (green) in the E12.5 ventral pancreatic bud. (K and L) Coimmunofluorescence staining of Cpa1 (green), Pdx1 (red), and Neurog3 (white) in the ventral pancreatic bud indicates that the DKO embryos are defective in pancreatic cell differentiation at E12.5, with the loss of multipotent progenitor marker Cpa1 and endocrine progenitor marker Neurog3 (n = 4; 20 sections evenly distributed through the entire pancreas were analyzed for each n). (M and N) Coimmunofluorescence staining of Ptf1a (red) and glucagon (green) in the E12.5 ventral pancreatic bud shows more centralized Pft1a distribution and much reduced glucagon-positive cells (N vs. M) *P < 0.05. Original magnification, ×60 (A and B); ×200 (C–F); ×400 (I–N, and insets).