Figure 1.

Molecular switches regulating hair growth. A variety of inter- and intracellular signaling molecules play critical roles in the formation of new hair. The negative regulators of hair growth include BMP and TGF-β signaling, whereas Wnt and Shh signaling activates anagen entry. The Wnt-mediated hair regrowth involves the stabilization of hypophosphorylated β-catenin, which interacts with TCF/LEF and translocates to nucleus to promote transactivation of growth promoting genes. Abbreviations: BMP, Bone morphogenetic proteins; TGF-β, Transforming growth factor-β; Smad, homologs of the Drosophila protein, mothers against decapentaplegic (Mad) and the Caenorhabditis elegans protein Sma; SBE, Smad-binding element; Wnt, wg derived from the Drosophila gene wingless (wg) and int derived from the proto-oncogene integration-1; TCF/LEF, T-cell factor/lymphoid enhancer factor; Shh, Sonic hedgehog; SMO-smoothened; Gli, glioma-associated oncogene family zinc finger 1.