Loading...
Epithelial stem cells inhabit the bulge region and secondary hair germ of hair follicles. Melanocyte stem cells also reside in the bulge region. The two cell populations cooperate to regenerate pigmented hair. During anagen, the epithelial stem cells divide and proliferate to form the new anagen follicle and eventually, the hair itself. The melanocyte stem cells also divide and proliferate and transfer pigment to the epithelial cells to produce black hair. Epithelial stem cell behavior is directed by the Wnt (pronounced “wint”) pathway. When Wnt is activated, signaling molecules bind to receptors that inhibit degradation of β-catenin. The undestroyed β-catenin moves to the nucleus, where it regulates transcription of Wnt target genes. These…