Keratin Is Not Only a Structural Protein in Hair: Keratin-Mediated Hair Growth

The pilot study conducted three years ago revealed a new biological function of keratin in hair growth. The researchers found that hair growth was stimulated by the intradermal injection of keratin into mice. The process involved outer root sheath cells undergoing transforming growth factor-β2-induced apoptosis, which resulted in keratin exposure. This exposure was found to be crucial for dermal papilla cell condensation and hair germ formation. When keratin was silenced, it prevented these processes and significantly suppressed anagen follicle formation and hair growth. These findings suggested a new method for initiating hair regeneration and indicated the potential use of keratin biomaterial in treating hair loss.