A pathway known for its role in regulating adult stem cells has been shown to be important for hair follicle proliferation, but contrary to previous studies, is not required within hair follicle stem cells for their survival, according to researchers with the Perelman School of Medicine at the University of Pennsylvania. A new study, published in Cell Stem Cell, identifies a molecular pathway that can be activated to prompt hair growth of dormant hair follicles, or blocked to prevent growth of unwanted hair.
The team examined the functions of Wnt proteins, which are small molecular messengers that convey information between cells and activate signaling via the intracellular molecule β-catenin. By disrupting Wnt signaling in an animal model with an inhibitor Dkk1, the team found that hair growth was prevented. However, stem cells were still maintained within the dormant hair follicles. When Dkk1 was removed, the Wnt/β-catenin pathway resumed normal function, the stem cells were activated, and hair growth was restored.