Effect of Activated Hair Follicle Stem Cells on Gene Expression During Hair Regrowth in Mice

The hair cycle, consisting of anagen, catagen, and telogen phases, is orchestrated by bulge-resident hair follicle stem cells (HFSCs). Although HFSCs remain quiescent throughout most of the cycle, they undergo robust proliferation and differentiation during early anagen to reconstitute the distinct layers of the hair follicle. In this study, we demonstrate that intradermal administration of activated HFSCs accelerates hair regrowth and upregulates hair growth-associated genes in depilated mouse skin, thereby establishing a molecular framework for HFSC-based regenerative strategies.