DNA dioxygenases Tet2/3 regulate gene promoter accessibility and chromatin topology in lineage-specific loci to control epithelial differentiation

Execution of lineage-specific differentiation programs requires tight coordination between many regulators including Ten-eleven translocation (TET) family enzymes, catalyzing 5-methylcytosine oxidation in DNA. Here, by using Keratin 14-Cre-driven ablation of Tet genes in skin epithelial cells, we demonstrate that ablation of Tet2/Tet3 results in marked alterations of hair shape and length followed by hair loss. We show that, through DNA demethylation, Tet2/ Tet3 control chromatin accessibility and Dlx3 binding and promoter activity of the Krt25 and Krt28 genes regulating hair shape, as well as regulate interactions between the Krt28 gene promoter and distal enhancer. Moreover, Tet2/Tet3 also control three-dimensional chromatin topology in Keratin type I/II gene loci via DNA methylation-independent mechanisms. These data demonstrate the essential roles for Tet2/3 in establishment of lineage-specific gene expression program and control of Dlx3/Krt25/Krt28 axis in hair follicle epithelial cells and implicate modulation of DNA methylation as a novel approach for hair growth control.

Automated summary

Loss of Tet2 and Tet3 in skin epithelial cells causes significant changes in hair shape and length, leading to hair loss. Tet2 and Tet3 control the chromatin accessibility and promoter activity of hair shape-related genes (Krt25 and Krt28) through DNA demethylation, as well as the interactions between the Krt28 gene promoter and distal enhancer. In addition, Tet2 and Tet3 also regulate three-dimensional chromatin topology in Keratin type I/II gene loci via DNA methylation-independent mechanisms. These findings highlight the crucial roles of Tet2 and Tet3 in lineage-specific gene expression and hair growth control, and suggest DNA methylation modulation as a potential novel approach for hair growth control.