Foxc1 reinforces quiescence in hair follicle stem cells

Quiescent stem cells are periodically activated to maintain tissue homeostasis or occasionally called into action upon injury. Molecular mechanisms that constitutively maintain stem cell identity or promote stem cell proliferation and differentiation upon activation have been extensively studied. However, it is unclear how quiescent stem cells maintain identity and reinforce quiescence when they transition from quiescence to activation. Here we show mouse hair follicle stem cell compartment induces a transcription factor, Foxc1, when activated. Importantly, deletion of Foxc1 in the activated but not quiescent stem cells compromises stem cell identity, fails to re-establish quiescence and subsequently drives premature stem cell activation.These findings uncover a dynamic, cell-intrinsic mechanism employed by hair follicle stem cells to reinforce stemness in response to activation. Overall design: Poly(A)-enriched transcriptome RNA-seq on HFSCs isolated in WT and K14Cre cKO mice at anagen and early telogen stage of hair cycle.

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Wang L, Siegenthaler JA, Dowell RD, Yi R