Treating Baldness is "Not Like Growing Grass"

Treating Baldness is "Not Like Growing Grass"

By Rose Eveleth

Date: June 8, 2012
Source: scientificamerican.com

Progress may seem slow, but new treatments for hair loss are underway

Plain Grass lawn

More than 40 percent of men in the U.S. will show signs of male-pattern baldness sometime between the ages of 18 and 49. But studies looking at the genomes of this group of men have failed to turn up a genetic cause, which makes a true cure seem an unlikely prospect. 

Treatments for male-pattern baldness, also known as androgenic alopecia, may be forthcoming, however. Recent work is homing in on three types, including one that was reported in March in the journal Science. In the new paper, George Cotsarelis of the University of Pennsylvania and his team found that a compound known as prostaglandin D2 (PD2) was elevated in the blood of men with male-pattern baldness. When they blocked PD2 receptors in mice, they ensured that the hair did not stop growing. Those blockers could be applied topically, Cotsarelis says.

He is also working on growing new hair. Researchers have noticed that if you wound a mouse, the animal generates new hair follicles as part of the healing process. The new follicles come from skin cells that turn into hair follicles through what is called the Wnt-mediated signaling pathway. It is the same pathway that helps you generate new hairs naturally as they fall out. Cotsarelis is working with a company to replicate that process.

A third approach, called follicular neogenesis, would allow doctors to remove, multiply and then reimplant the stem cells found inside a person’s hair follicles. So far, though, when researchers remove the stem cells and culture them, the cells appear to “forget” they were ever hair cells. Researchers are now attempting to figure out how to restore their “memory.”

As scientists continue to search for treatments to androgenic alopecia, they recommend patience. “People think of it like growing grass or something, but it’s nothing like that,” Cotsarelis says. “It’s like trying to treat cancer; it’s a complicated process.”

This article was published in print as "It's Not "Like Growing Grass"."

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Baldness Protein Found in Study That May Lead to Treatments

Baldness Protein Found in Study That May Lead to Treatments

By Elizabeth Lopatto - Mar 21, 2012 7:41 PM GMT+0100

Source: bloomberg.com

Male-pattern baldness may be caused by a protein in the scalp, according to research that raises the possibility drugs being tested by Merck & Co. (MRK) and Actelion Ltd. (ATLN)for other uses might prevent hair loss.

Bald spots had an excessive amount of a protein called prostaglandin D2 or PGD2, according to a study in Science Translational Medicine. Merck’s experimental treatment for facial flushing and Actelion’s allergy compound, both in late-stage studies, block the protein.

About eight out of 10 white men experience some balding before the age of 70, according to the researchers. Johnson & Johnson (JNJ)’s Rogaine and Merck’s Propecia slow the loss, and some users see minor hair growth. Men may be able to regrow all their hair if the inhibiting protein is removed, said George Cotsarelis, chairman of dermatology at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia.

“We really do think if you remove the inhibition, you get longer hair,” Cotsarelis, a study author, said in a telephone interview. “We don’t know” if the follicles will return to their former lengths, he said.

The study was funded by grants from the National Institutes of Health, the Pennsylvania Department of Health, and other medical groups.

Bald Parts
The researchers looked at all the genes in the scalp samples from five men, comparing the bald parts to the haired parts. They found higher expressions of the gene that produces PGD2 in the bald samples, compared to the spots with hair. With that as a guide, they found in samples of 17 men with hair loss that PGD2 was three times higher in the bald spots than where hair was growing. The scientists then used mice to show that excessive PGD2 decreased follicles.

Previous work has shown that the stem cells that create hair are still intact in bald men, Cotsarelis said. The follicles are also there, though they look smaller and produce thinner, shorter hair. Over time, the hair is so short it no longer passes the surface of the skin.

“This makes me wonder if this is the pathway,” saidParadi Mirmirani, a dermatologist at Kaiser Permanente in Vallejo, California. She wasn’t involved in the study. “In terms of therapeutics, it really opens the door to have someone come in and target these in a very narrow way.”

Final Studies
Merck, based in Whitehouse Station, New Jersey, is testing laropiprant as a flushing inhibitor to be administered with niacin. Allschwil, Switzerland-based Actelion’s setipiprant is being studied as a treatment for allergic inflammation of nasal pathways. Both therapies are in the final phase of testing generally needed for regulatory approval.

Merck isn’t studying the anti-flushing drug in hair loss, said Ian McConnell, a Merck spokesman, in a telephone interview.“We haven’t seen any signals” in patient trials that the therapy might reduce baldness, he said.

Actelion isn’t testing setipiprant as a baldness treatment, said Roland Haefeli, a company spokesman.

The role prostaglandins might play in hair growth was hinted at by Allergan Inc. (AGN)’s Latisse, which is an artificial version of prostaglandin F2-alpha, said Mirmirani. Latisse was originally developed for glaucoma, and doctors discovered it made eyelashes grow.

“They could pick out who was on it from the waiting room because of the super-long eyelashes,” Mirmirani said in a telephone interview.

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