Endothelin signalling drives dermal sheath smooth muscle contraction for hair follicle regression

Contraction of the hair follicle-lining dermal sheath smooth muscle generates the forces necessary for the tissue remodelling that takes place during the regression phase of the hair growth cycle. This study reveals that endothelin signalling — from epithelial progenitors at the follicle bottleneck region to its neighbouring dermal sheath — is the main contraction-activating pathway.