Could a cure for baldness be on the horizon?
According to new research from the Pearlman School of Medicine at the University of Pennsylvania, a discovery made could lead to new treatments for male pattern baldness, the most common cause of hair loss in men. Male pattern baldness, the researchers indicate, strikes eight of 10 men under the age of 70. The condition causes hair follicles to shrink and produce microscopic hairs, which grow for a shorter period of time than do normal hair follicles.
In both human and animal models, researchers found that a prostaglandin known as PGD2 and its derivative, 15-dPGJ2, inhibit hair growth. The PGD2-related inhibition occurred through a receptor called GPR44, which is a promising therapeutic target for androgenetic alopecia in both men and women with hair loss and thinning hair.
"Although a different prostaglandin was known to increase hair growth, our findings were unexpected, as prostaglandins haven't been thought about in relation to hair loss, yet it made sense that there was an inhibitor of hair growth, based on our earlier work looking at hair follicle stem cells," said George Cotsarelis, MD, chair and professor of Dermatology, and senior author on the studies, in a release. In a Penn study published in the Journal of Clinical Investigation last year, underlying hair follicle stem cells were found intact, suggesting that the scalp was lacking an activator or something was inhibiting hair follicle growth.
Prostaglandins are well characterized for their role in many bodily functions — controlling cell growth, constricting and dilating smooth muscle tissue — and a different prostaglandin (F2alpha) is known to increase hair growth. Researchers found that as PGD2 inhibits hair growth, other prostaglandins work in opposition, enhancing and regulating the speed of hair growth.
The research from this study indicated that levels of PGD2 were elevated in the bald scalp tissue of men with androgenetic alopecia at levels three times greater than what was found in comparative areas with hair in the scalps of the same men. And, when PGD2 was added to cultured hair follicles, the hair was significantly shortened; 15-dPGJ2 completely inhibited hair growth.
While these studies looked at androgenetic alopecia in men, the researchers noted that prostaglandins may represent a common pathway shared by both men and women with the condition. Future studies, potentially testing topical treatments that may target GPR44, can determine whether targeting prostaglandins will benefit women with androgenetic alopecia, as well.
The study article, “Prostaglandin D2 Inhibits Hair Growth and Is Elevated in Bald Scalp of Men with Androgenetic Alopecia,” is available online on the Science Translational Medicine journal website.
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