Yale researchers report that signals from stem cells in the fatty layer of the skin may trigger the growth of new hair. The study in mice may lead to better understanding and treatments to reverse baldness in humans.
Researchers know that men with male pattern baldness still have the stem cells that are necessary for hair growth in their follicle roots, but the cells are dormant and can’t spur growth. It’s also been known that the hair follicle stem cells need signals from within the skin to grow hair. The question is, where do the signals come from?
Reported the BBC:
[The Yale team] said there was a four-fold increase in the number of “precursor” fat cells in the skin around a hair follicle when it started to grow.
They looked at defective mice, which could not produce these fat cells. Hair normally grows in cycles, but in the defective mice, the follicles had become trapped in the dormant phase of the cycle.
Scientists injected fat cells from healthy mice into the defective mice. Two weeks later, hair follicles had started to grow.
The researchers also found that the precursor fat cells were producing a platelet-derived growth factor — at 100 times the level of surrounding cells — that appeared to be kick-starting the follicles to grow hair. Injecting the growth factor into the skin of defective mice could trigger hair growth in 86% of follicles.
Of course, the researchers will have to show that the cellular signaling involved in human baldness are the same as they are in mice. If they are, the findings could help scientists develop new treatments for hair loss.
“If we can get these fat cells in the skin to talk to the dormant stem cells at the base of hair follicles, we might be able to get hair to grow again,” Valerie Horsley, assistant professor of molecular, cellular and developmental biology at Yale and a senior author of the paper, said in a statement.