Prostaglandin D2 Linked to Hair Loss in Androgenetic Alopecia
Prostaglandin D2 increased in bald versus haired scalp; inhibits hair growth in mice
FRIDAY, March 23 (HealthDay News) -- Prostaglandin D2 (PGD2) plays a role in inhibition of hair growth in androgenetic alopecia (AGA), according to a study published in the March 21 issue of Science Translational Medicine.
Luis A. Garza, M.D., Ph.D., from the University of Pennsylvania School of Medicine in Philadelphia, and colleagues investigated the mechanisms for decreased hair growth in AGA. A global gene expression approach was used to define differentially expressed genes in balding and nonbalding scalp sections from the same individuals.
The researchers found that, compared with haired scalp of men with AGA, in bald scalp, prostaglandin D2 synthase (PTGDS) was increased at the messenger RNA and protein levels. PGD2 was similarly increased in bald scalp. In mice, during the normal follicle cycle, there was an increase in Ptgds and PGD2 levels immediately preceding the regression phase. In explanted human hair follicles and in topical application to mice, PGD2 inhibited hair growth. The PGD2 receptor G protein-coupled receptor 44 (GPR44), but not PGD2 receptor 1, was necessary for hair growth inhibition. A transgenic mouse model, K14-Ptgs2, which targeted prostaglandin-endoperoxide synthase 2 expression to the skin, had hallmarks of human AGA, including increased levels of PGD2 in the skin, alopecia, follicular miniaturization, and sebaceous gland hyperplasia.
"These results define PGD2 as an inhibitor of hair growth in AGA and suggest the PGD2-GPR44 pathway as a potential target for treatment," the authors write.
Several of the authors are listed as co-inventors on patents related to hair growth and loss, one of which is owned by the Gillette Corporation.