Mice Can Regenerate New Hair Follicles After Wounding
Results suggest Wnt activators may help hair regeneration
WEDNESDAY, May 16 (HealthDay News) -- Adult mice can regenerate hair follicles after being wounded due to the activation of Wnt signaling pathways in epithelial cells that do not normally form hair, researchers report in the May 17 issue of Nature.
George Cotsarelis, M.D., of the University of Pennsylvania School of Medicine in Philadelphia, and colleagues sought to characterize structures that resembled developing hair follicles that they noticed in large healing wounds in genetically normal mice. Wounding was accomplished by removing a 1 cm-square area of full-thickness back skin.
The investigators found that within weeks after wounding, new hair follicles were present and expressed markers of follicle differentiation similar to those observed during embryogenesis. Genetically labeled epidermal stem cells were rarely found in the regenerated hair follicles suggesting that new follicles originate from cells outside the hair follicle stem cell niche. Regeneration could be enhanced or diminished by activating or inhibiting the Wnt signaling pathway, respectively.
"This de novo formation of hair follicles in adult animals recapitulates embryogenesis at the molecular level, and provides a potential window for manipulating the number of hair follicles that form, by exposure to Wnts," the authors write. "This raises the possibility of treating acute wounds with modulators of the Wnt pathway to decrease scar formation, and treating hair loss by regenerating follicles through wounding and Wnt pathway activation."