A pill for gray hair
Maria Perepechaeva, "First-hand Science" based on Medical Daily: A Drug To Reverse Grey Hair And Vitiligo? Scientists Find 'Switch' For Skin And Hair Pigmentation
A pill for gray hair sounds like a dream. The research of scientists from the Langone Medical Center at the University of New York (NYU Langone Medical Center), studying the molecular mechanisms responsible for skin and hair color, can turn this dream into reality
Melanocytes – the cells responsible for the color of hair and skin – produce the pigment melanin. If melanocytes lose their function or die, for example, with age, the hair turns gray.
A similar skin condition is called vitiligo. In addition to age, other factors can affect the "health" of melanocytes: genetic, hormonal, exposure to toxins, stress, the presence of autoimmune diseases.
Vitiligo is a pigmentation disorder, which is expressed in the loss of color of some areas of the skin. By itself, this disease does not affect human health in any way, but it looks unaesthetic and can cause psychological discomfort. Of course, the skin, like gray hair, can be dyed, but in practice it is more difficult. There is no effective treatment at the moment. According to the National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS, USA), vitiligo occurs in about 0.5-1% of people in the world, regardless of gender, age and nationality. Sometimes vitiligo localizes to a certain area of the skin, sometimes it spreads throughout the body – for someone slowly, for many years, for someone quickly.
The peculiarity of melanocyte stem cells, as well as other hair follicle stem cells, is their cyclic functioning. The active phase, when a melanocyte divides and produces a differentiated cell capable of "supplying" pigment, is followed by a regression phase, when differentiated melanocytes undergo apoptosis, and stem cells survive and reactivate after rest in the next cycle.
The molecular mechanisms of regulation of these processes are only partially known. American scientists have investigated the role of the endothelin receptor type B signaling pathway in them. The signaling pathway is a strictly defined sequence of molecular events that is triggered in response to the corresponding signal and serves to transmit information. It turned out that mice with a defect in the endothelin receptor type B signaling pathway turn gray prematurely, and with hyperstimulation of this pathway, on the contrary, hyperpigmentation of hair and skin is observed in animals.
It was also found that even in the presence of endothelin proteins, the growth and maturation of melanocyte stem cells can be stopped by blocking another signaling pathway called Wnt. Wnt proteins are known for their involvement in the regulation of the vital activity of stem cells, including melanocytes, but the connection with endothelin proteins has been shown for the first time.
The fact that the endothelin B receptor is somehow involved in the functioning of melanocytes was known before: its mutations are associated with Waardenburg syndrome, a genetic disease, one of the symptoms of which are pigmented skin abnormalities. However, it was unclear how the endothelin receptor works "normally". The researchers believe that the results obtained may eventually lead to the appearance of drugs that control the "behavior" of the endothelin type B receptor signaling pathway, which will make it possible to save people from premature gray hair and vitiligo.
Article by Takeo et al. EdnrB Governs Regenerative Response of Melanocyte Stem Cells by Crosstalk with Wnt Signaling published in the journal Cell Reports – VM.
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23.05.2016