TET1-V5 ChIP-seq. TET1-V5 ChIP-seq

Changes in DNA methylation are associated with normal cardiogenesis, while altered methylation patterns can occur in congenital heart disease. Ten-eleven translocation (TET) enzymes oxidize 5-methylcytosine (5mC) and promote locus-specific DNA demethylation. Here we characterize stage-specific methylation dynamics and the function of TETs during directed differentiation of human embryonic stem cells (hESCs) to cardiomyocyte (CM) fate. No defect is observed using isogenic TET2, TET3 or TET2/3 double knockout lines, while TET1 knockout lines display a significant decrease in capacity to generate CTNT+ CMs. Moreover, hESCs in which all three TET genes are inactivated (TET TKO hESCs) fail entirely to generate CMs. TET-deficient cells display altered mesoderm patterning and defective cardiac progenitor specification. Genome-wide methylation analysis shows that TETs are required first to maintain hypomethylation of early regulatory genes, and subsequently for demethylation of cardiac structural genes. Mechanistically, TET knockout causes promoter hypermethylation of genes encoding WNT inhibitors, leading to hyperactivated WNT signaling and defects in cardiac mesoderm patterning. TET activity is also needed to maintain hypomethylated status and expression of NKX2-5 for subsequent cardiac progenitor specification. Finally, loss of TETs causes a set of cardiac structural genes to fail to be demethylated at the cardiac progenitor stage. Our data demonstrate key roles for TET proteins to control methylation dynamics at sequential steps during human cardiac development. Overall design: V5 CHIP-seq was perfromed at D7 cardiac progenitor (CP) cells in the background of TET1-V5 endogenously tagged H1 stem cell line