Progenitor-Derived Endothelin Controls Dermal Sheath Contraction for Hair Follicle Regression

The study "Progenitor-derived endothelin controls dermal sheath contraction for hair follicle regression" reveals that endothelin signalling is vital for hair follicle regression, a process regulated by the contraction of the dermal sheath smooth muscle. The researchers discovered that blocking or genetically removing endothelin receptors, ETA and ETB, prevents this contraction and halts follicle regression. The endothelin ligand ET-1, produced by epithelial progenitors, is necessary for this process. The study also found that ET signalling and the subsequent contraction is regulated by cytoplasmic Ca2+ levels through specific calcium channels. This research provides new insights into how progenitor cells control tissue regression and reorganization for the next stem cell activation and regeneration cycle.