Androgenetic alopecia affects around 50 million men and 30 million women in the US. Currently, drugs known as finasteride and minoxidil are approved by the US Food and Drug Administration (FDA) to treat the condition. However, finasteride has only been approved for men, and both drugs are not universally effective. They also must be taken daily to maintain their effects.
It has been known for some time that dermal papilla cells- specialized signal-making fibroblasts at the bottom of each hair follicle- send signals that either keep follicles dormant or trigger new growth. In people with androgenetic alopecia, dermal papilla cells malfunction, thus reducing signaling activity. Until now, the genetic basis for activating these cells has remained unknown.
In the present study, researchers studied a mouse model of hyperactive dermal papilla cells and excessive hair. In doing so, they found that the SCUBE3 signaling molecule, which is naturally produced by the dermal papilla cells, is key for signaling hair stem cells to divide and generate new hair growth. In mouse experiments, they found that microinjections of SCUBE3 can grow new hair from dormant human hair follicles implanted in mice.
"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," said Maksim Plikus, Ph.D., University of California- Irvine professor of developmental & cell biology and one of the study’s authors, “Our test in the human hair transplant model validates the preclinical potential of SCUBE3."
Sources: Science Daily, Developmental Cell