The end of baldness?

Has a cure for baldness finally been found?

This week, researchers at the University of Pennsylvania said they have identified the underlying cause of male pattern baldness and believe they know how to stop it.

The announcement follows the team's discovery last year of hair-follicle stem cells in bald scalps. Those stem cells, which in theory can reproduce an almost infinite number of hair follicles, should be able to grow a full head of hair.

"At that time, we hypothesized there is either a lack of an activator in the scalp or the presence of an inhibitor that prevented the stem cells from generating hair," said George Cotsarelis, the senior author of the study and a professor of dermatology at the university's Perelman School of Medicine.

So, the researchers set out to find the culprit. They compared patches of bald scalp to hair-covered scalp. The analysis revealed the bald tissue contained elevated levels of a protein called prostaglandin D2.

In a series of experiments, they added increasing amounts of prostaglandin D2 to hair follicles transplanted to a lab dish and found the hair stopped growing. What's more, they pinpointed the exact receptor – GPR44 – through which prostaglandin D2 halts hair-follicle growth, according to the findings published in the journal Science Translational Medicine.

"We think if we are able to remove the inhibitory effects of prostaglandin D2 we would be able to allow the hair to grow," said Dr. Cotsarelis.

He noted that there are already several experimental drugs that blocks the GPR44 receptor – the prime target of prostaglandin D2.

One of them is currently being tested as a possible treatment for asthma because prostaglandins play a role in many biological activities, including lung function. But if it is put on a bald scalp it may be able to counteract the negative effects of prostaglandin D2 on hair follicles, speculated Dr. Cotsarelis.

"The next question is whether it can prevent further hair loss, or actually reverse hair loss … and re-grow hair on a bald scalp," he added.

The clinical trials should attract a lot of public interest. Male pattern baldness strikes eight out of 10 men under the age of 70. And about 30 per cent of women experience some degree of hair loss as they grow older.