A newly identified stem cell defect may be an underlying cause of male-pattern baldness, U.S. researchers have found.
The defect, a cellular malfunction, short-circuits the process by which hair follicle stem cells turn into hair-producing progenitor cells, according to researchers at the University of Pennsylvania.
The malfunction sparks the onset of androgenetic alopecia, the medical term for a type of genetic hair loss that affects both men and women, the researchers said.
In men, this hair loss is commonly known as male pattern baldness, marked by the familiar receding hairline and thinning hair on top of the head — a condition that sometimes leads to complete baldness. In women, female-pattern hair loss causes the hair to get thinner all over but rarely leads to baldness, the researchers explained.
The findings were published Jan. 4 in the Journal of Clinical Investigation.
In people who are bald, hair follicles have shrunken and become microscopic, said study researcher Dr. George Cotsarelis, a professor of dermatology at the university.
“Previously we thought the stem cells were gone, and if that was the case it would be very difficult. But because they are present it should be possible to treat,” he said.
The new study shows that bald people have the same number of stem cells as those with hair. So if scientists could coax the stem cells into producing more hair follicle progenitor cells, then it would be possible to generate bigger hair follicles that could grow hair, according to Cotsarelis.
Cotsarelis and his colleagues analyzed skin cells from the bald and non-bald parts of the scalp of people with androgenetic alopecia, the technical name for male-pattern baldness.
They ran the scalp cells through a machine that tagged each cell with a marker. By using different markers to distinguish between stem cells and hair follicle progenitor cells, scientists were able to count the number of each type.
They found there were the same number of stem cells in the skin from bald scalps as there were in the skin from the non-bald scalps. However there were fewer hair follicle progenitor cells in the skin from the bald scalps than the skin from the non-bald scalps.
In other words, baldness was occurring because the stem cells were unable to complete their normal development and become hair follicle progenitor cells.
The discovery gives hope that people who are bald could regrow their hair with a future treatment, said Cotsarelis. (PNA/Xinhua)
