ASH2L Mediates Epidermal Differentiation and Hair Follicle Morphogenesis via H3K4me3 Modification

The study investigates the role of ASH2L, a core subunit of the COMPASS methyltransferase, in epidermal differentiation and hair follicle morphogenesis in mice. Using a mouse model with ASH2L deletion in epidermal progenitor cells, researchers found that the absence of ASH2L led to a thinner suprabasal layer of the epidermis and delayed hair follicle development. This was attributed to reduced proliferative capacity of progenitor cells and depletion of epidermal stem cell pools. RNA sequencing and CUT&Tag sequencing identified several downstream genes, including those involved in hair follicle development and the Notch signaling pathway, regulated by H3K4me3. The findings highlight ASH2L-dependent H3K4me3 modification as a crucial epigenetic regulator in these processes.