Danny DeVito: Help in sight

Washington, March 15 (Reuters): Scientists who found long-living master cells in the hair follicles of mice have said they may now be able to pinpoint the same cells in people — providing future treatments for baldness and perhaps a range of diseases, too.

They said they had shown that the hair follicles of mice contain true adult stem cells, which have the potential to grow not only new hair but various types of tissue.

When they transplanted the cells in mice, hair sprouted where none had been before.

Careful work showed the cells were stem cells, Dr George Cotsarelis of the University of Pennsylvania Medical Center and colleagues reported.

Writing in the April issue of Nature Biotechnology, Cotsarelis said certain genes were activated in the stem cells that were not activated in other hair follicle or skin cells. Drugs that affect these genes in people might lead to new ways of controlling hair growth, they said. And tracking the genes will allow them to find the same cells in people.

“By defining these molecular markers, we will be able to isolate human stem cells from hair follicles,” Cotsarelis, a dermatologist and molecular biologist, said in a telephone interview.

His team showed several years ago that human hair follicles contained stem cells — they just did not know how to identify them and single them out.

The immediate hope is for a cure for baldness and a more serious medical hair-loss condition called alopecia, but Cotsarelis said the findings could lead to better treatment for burns and wounds and may offer insight into the aging process and the development of cancer. “One problem with a burn is that the wound is never covered with hair follicles,” Cotsarelis said. “These cells have that capability so if we can isolate them and seed them onto a wound we can constitute skin that is more normal than currently possible.”

And because they are stem cells, they have the ability to grow and proliferate more than mature cells, so it may be possible to use them to grow a better skin graft faster, he said. And in aging, it is believed the skin stem cells die off. If scientists can learn how to control that process, some aspects of aging skin could be prevented, Cotsarelis added.

The researchers also learned more about what causes hair loss. “We also provide unexpected evidence that the hair follicle is an immune-privileged site,” they wrote. This means immune system cells do not get into the follicle.