DP-2 antagonists reversed PGD2-mediated human hair growth inhibition in a dose-dependent manner in vitro by reducing PGD2-triggered apoptosis and maintaining proliferation of keratinocytes. Hair follicles from approximately half of the alopecia patients exhibited little susceptibility to PGD2's effect in vitro. SNPs in the human DP-2 gene were identified that are associated with hair growth inhibition by PGD2. These findings underscore the role of DP-2 in regulating hair growth and indicate that DP-2 can be an effective approach in preventing and/or treating androgenetic alopecia in patients sensitive to PGD2. Furthermore, the SNPs identified here can be used to identify patients who will benefit from treatment.
