Blocking the contraction of the "dermal sheath" could halt hair loss
Scientists have uncovered a new mechanism behind hair loss, and one they think could be leveraged to prevent the onset of male patten baldness. By stopping a newly discovered muscle movement that is key to the shedding of old follicles, scientists believe they may one day be able intervene to help men hang onto their hair, potentially for a lifetime.
The newly discovered mechanism centers on a component of the hair called the dermal sheath. This surrounds the outside of the hair follicles and has long been known to play a key role in regenerating the dermal papilla at the base of the hair follicle, which is crucial to its growth.
But scientists at New York's Icahn School of Medicine at Mount Sinai suspected it may be responsible for a little bit more. As each hair lives out its existence, dermal papilla cells at the base of the growing follicles travel up towards the stem cells at the follicle's tip. The dermal papilla cells signal to the stem cells when it is time to create a new hair shaft, and the older hair shaft is disposed of. But sometimes this communication breaks down, according to the researchers.
Investigating how this relationship plays out in mice, the team found that the dermal sheath actually works as a smooth muscle, contracting and expanding to push up the hair shaft and take the dermal papilla cells along for the ride. Follow up experiments suggested that the same process is at play in human hair, and showed that as the hair enters its "destruction" phase, the dermal sheath contracts to allow the unwanted strands to fall out.
"Blocking the newly discovered muscle and its contraction cannot cure baldness caused by those processes," said lead researcher Dr. Michael Rendl. "Instead, blocking contraction and arresting the destruction phase of the cycle has the potential to retain the existing hair shaft that is otherwise lost when a new hair shaft is produced."
This raises the possibility of using drugs to prevent the contraction of the dermal sheath to save the loss of hair normally destined for the drain, though there's a lot of work to do first. The next steps would be to demonstrate this capability on human hairs in a dish, and then prove its long-term safety in real life subjects.
"We are excited about exploring this," Rendl said.
The research was published in the journal Science.
Source: Medical XPress