In the article recently published in Science Translational Medicine, it was shown that the enzyme prostaglandin D2 (PGD2) was elevated in bald scalps at the mRNA and protein levels.
In a group of 17 men, bald scalp was compared with haired scalp and showed elevated PGD2 levels. The authors also found that PGD2 and a related metabolite 15-dPGJ2 inhibited hair growth in both mice and men, providing insights into the prostaglandin pathway in genetic balding. They found a receptor in the bald scalp which is responsible for mediating the negative effects of PGD2, suggesting that therapeutic drug targets could be developed for a possible topical treatment. They have determined that this receptor may impact the hair characteristics (i.e. straight or curly).
Dr. Walter Unger wrote his take as follows:
Unfortunately, baldness is not caused by a single factor but rather multiple ones. The most important and well-known one is the correlation of balding with a male hormone called dihydrotestosterone (which is a byproduct of the more well-known testosterone). Specifically, we have known for many years that you cannot develop MPB unless you have an excess production of that hormone in the affected areas. Yet, many years later, we still do not have a “cure” for everybody’s baldness either in terms of stopping the progression in everybody or regrowing hair in everybody though anti-dihydrotestosterone drugs such as finasteride (Propecia) and Dutasteride certainly help many people with male pattern baldness (MPB) and female pattern hair loss (FPHL)—to varying degrees.
Dr. Garza’s and Dr. Cotsarelis’s announcement of the role of another factor, Prostaglandin D2 synthase, appears to represent another building block towards the ultimate goal of medical treatment of MPB and perhaps FPHL. However, we have no idea as yet, if it is, for example, more or less important than dihydrotestosterone or any other of the substances already implicated in MPB and FPHL. Unfortunately, despite the media frenzy, “the end of baldness” likely remains well down the road.