Epithelial Wnt Ligand Secretion Is Required for Adult Hair Follicle Growth and Regeneration

The study from January 1, 2013, demonstrated that epithelial Wnt ligands are essential for adult hair follicle growth and regeneration. By genetically deleting the Wntless (Wls) gene in mice, which is necessary for Wnt ligand secretion, researchers observed a significant arrest in the hair cycle, specifically in the transition to the anagen phase. The absence of Wls led to decreased Wnt/ß-catenin signaling and reduced proliferation of hair follicle stem cells, although stem cell markers were maintained. The study also found that Wnt ligands are critical for wound-induced hair formation, suggesting their importance in hair follicle regeneration. These findings imply that Wnt ligand secretion by the hair follicle epithelium could be a potential target for treating hair loss disorders like alopecia.