IRVINE, Calif. — Scientists have discovered the molecular signal which triggers potent hair growth in both men and women. The discovery of this signaling molecule, SCUBE3, may finally put an end to baldness and hair loss conditions such as alopecia.
Researchers from the University of California-Irvine say dermal papilla cells are responsible for promoting new hair growth. These are specialized signal-making fibroblasts (cells which produce collagen) that sit at the bottom of each hair follicle. Although scientists knew dermal papilla cells contributed to the growth of hair, they didn’t have a clear picture of the genetic process behind it — until now.
“At different times during the hair follicle life cycle, the very same dermal papilla cells can send signals that either keep follicles dormant or trigger new hair growth,” says Maksim Plikus, Ph.D., UCI professor of developmental & cell biology, in a university release. “We revealed that the SCUBE3 signaling molecule, which dermal papilla cells produce naturally, is the messenger used to ‘tell’ the neighboring hair stem cells to start dividing, which heralds the onset of new hair growth.”
The study reveals that activating SCUBE3 by the dermal papilla cells is a key step in growing hair for both mice and people.
What happens when hair growth goes wrong?
In conditions like androgenetic alopecia, dermal papilla cells don’t function properly. This reduces the amount of normally abundant activating molecules available. During the new study, researchers used mice with hyperactivated dermal papilla cells and excessive hair to examine this signaling process.
“Studying this mouse model permitted us to identify SCUBE3 as the previously unknown signaling molecule that can drive excessive hair growth,” notes co-first author Yingzi Liu, a UCI postdoctoral researcher in developmental & cell biology.
Further studies confirmed SCUBE3’s role in activating hair growth in humans as well as mice. In experiments, the team injected SCUBE3 into mouse skin which contained transplanted human scalp follicles. The molecule sparked new hair growth in both the human and surrounding mouse hair follicles.
“These experiments provide proof-of-principle data that SCUBE3 or derived molecules can be a promising therapeutic for hair loss,” explains co-first author Christian Guerrero-Juarez, a UCI postdoctoral researcher in mathematics.
Right now, there are only two drugs available which have received U.S. Food and Drug Administration approval that treat androgenetic alopecia — finasteride and minoxidil. However, finasteride is only approved for use in men and both drugs produce inconsistent results. Patients also need to take these drugs daily in order to see results.
“There is a strong need for new, effective hair loss medicines, and naturally occurring compounds that are normally used by the dermal papilla cells present ideal next-generation candidates for treatment,” Plikus concludes. “Our test in the human hair transplant model validates the preclinical potential of SCUBE3.”
The study is published in the journal Developmental Cell.