TET1 dioxygenase is required for FOXA2-associated chromatin remodeling in pancreatic beta-cell differentiation
Ontology highlight
ABSTRACT: Current knowledge about the role of epigenetic modifiers in pancreas development has been exponentially increased. However, the precise function of TET dioxygenases in pancreas specification remains poorly understood. Using a stepwise human embryonic stem cell (hESC) differentiation system, TET1/TET2/TET3 triple-knockout (TKO) cells displayed severe defects in pancreatic differentiation. Whole-genome analysis revealed TET depletion led to aberrant DNA methylation and chromatin remodeling. In comparison with methylome and hydroxymethylome datasets previously generated from hESCs, we identified unique pancreas-specific hyper-methylated and hypo-hydroxymethylated regions in TKO cells, where binding of pioneer transcription factor FOXA2 was remarkably enriched. Interestingly, transduction of full-length TET1 in TKO cells effectively rescued pancreatic differentiation and the expression of PAX4, a key determinant for -cell specification. Taking these findings together with genome-wide mapping of TET1 in pancreatic progenitors, we uncovered that TET1 co-occupied at a specific subset of FOXA2-bound loci featuring high levels of active chromatin. Locus-specific DNA methylation analysis revealed significant increases of 5-methylcytosine at the PAX4 enhancer in a TET1-dependent manner, consistent with defective generation of functional beta-cells from TET1-knockout hESCs. Thus, our study not only highlights the importance of TET-dependent epigenetic regulation in pancreas development but also unveils an essential role of TET1 in establishing beta-cell identity.
ORGANISM(S): Homo sapiens
PROVIDER: GSE146486 | GEO | 2022/04/13
REPOSITORIES: GEO
ACCESS DATA