CXXC5 Mediates DHT-Induced Androgenetic Alopecia via PGD 2 .

The number of people suffering from hair loss is increasing, and hair loss occurs not only in older men but also in women and young people. Prostaglandin D 2 (PGD 2 ) is a well-known alopecia inducer. However, the mechanism by which PGD 2 induces alopecia is poorly understood. In this study, we characterized CXXC5, a negative regulator of the Wnt/β-catenin pathway, as a mediator for hair loss by PGD 2 . The hair loss by PGD 2 was restored by Cxxc5 knock-out or treatment of protein transduction domain-Dishevelled binding motif (PTD-DBM), a peptide activating the Wnt/β-catenin pathway via interference with the Dishevelled (Dvl) binding function of CXXC5. In addition, suppression of neogenic hair growth by PGD 2 was also overcome by PTD-DBM treatment or Cxxc5 knock-out as shown by the wound-induced hair neogenesis (WIHN) model. Moreover, we found that CXXC5 also mediates DHT-induced hair loss via PGD 2 . DHT-induced hair loss was alleviated by inhibition of both GSK-3β and CXXC5 functions. Overall, CXXC5 mediates the hair loss by the DHT-PGD 2 axis through suppression of Wnt/β-catenin signaling.