Dissecting the Bulge in Hair Regeneration

The review "Dissecting the bulge in hair regeneration" examined the role of hair follicle stem cells (HFSCs) in hair growth, focusing on their location in the bulge region and their ability to self-renew and differentiate. It discussed the bulge-activation hypothesis, where slow-cycling label-retaining cells (LRCs) in the bulge are activated to regenerate hair follicles, and highlighted the roles of secondary hair germ (sHG) and bulge cells in hair growth. The study also explored the potential for hair follicle neogenesis in adult skin, particularly after wound healing, and identified Lgr6+ cells as contributors to new hair follicles. It noted the importance of Sox9+ cells in embryonic hair development and the interactions between HFSCs and melanocyte stem cells (McSCs) for pigmentation maintenance. The document discussed HFSCs' potential in treating skin diseases, linking scarring alopecias to inflammation in the follicular bulge and noting changes in progenitor subpopulations in androgenetic alopecia. It also suggested that basal cell carcinomas might originate from HFSCs due to Hedgehog pathway mutations, emphasizing the need for further research on HFSCs for skin disease treatments.