GATA6 Cooperates with EOMES/SMAD2/3 to Deploy the Gene Regulatory Network Governing Human Definitive Endoderm and Pancreas Formation

Abstract

Summary: Heterozygous de novo mutations in GATA6 are the most frequent cause of pancreatic agenesis in humans. In mice, however, a similar phenotype requires the biallelic loss of Gata6 and its paralog Gata4. To elaborate the human-specific requirements for GATA6, we chose to model GATA6 loss in vitro by combining both gene-edited and patient-derived pluripotent stem cells (hPSCs) and directed differentiation toward β-like cells. We find that GATA6 heterozygous hPSCs show a modest reduction in definitive endoderm (DE) formation, while GATA6-null hPSCs fail to enter the DE lineage. Consistent with these results, genome-wide studies show that GATA6 binds and cooperates with EOMES/SMAD2/3 to regulate the expression of cardinal endoderm genes. The early deficit in DE is accompanied by a significant reduction in PDX1+ pancreatic progenitors and C-PEPTIDE+ β-like cells. Taken together, our data position GATA6 as a gatekeeper to early human, but not murine, pancreatic ontogeny. : In this article, Chia et al. model human pancreatic agenesis in vitro that results from heterozygous loss of the GATA6 gene. Using both gene-edited and patient-derived hPSCs, they demonstrate that GATA6 serves as a gatekeeper to early human, but not murine, pancreatic ontogeny. Genome-wide studies further show that GATA6 binds to and cooperates with EOMES/SMAD2/3 to regulate the expression of cardinal endoderm genes. Keywords: GATA6, definitive endoderm, pancreatic agenesis, human pluripotent stem cells, disease modeling