Induction of Hair Re-growth by Protein Kinase C η

Abstract

Hair development is controlled by several families of signaling molecules, including Fgfs, Wnts and protein kinase Cs (PKC). Among PKC genes expressing in skin and hair follicle, the eta (η) isoform of PKC has been known to be a key regulator of the growth and differentiation of keratinocytes. We describe here that PKCη is involved in the hair cycle progression from telogen (quiescence phase) to anagen (growing phase). The hair re-growth was induced by a topical application of 12-o-tetradecanoylphorbol 13-acetate (TPA), a strong activator of PKC, on the dorsal skin of PKCη transgenic mice. The hair bulb grew down into the fatty tissue in PKCη transgenic mice after treatment of TPA, whereas it was located in the dermis in normal mice. Large amounts of the melanin accumulated in the hair follicles, indicating the initiation of anagen phase. Furthermore, introduction of PKCη by adenovirus vector into the skin of normal mice exhibited the remarkable newly hair growth. These findings might help to develop the novel chemical therapy for alopecia and establish the reconstitution of skin with hair follicles.