Gray hair and aging may be caused by stuck stem cells

New research has revealed that gray hair occurs when melanocyte stem cells (McSCs) become “stuck” in the hair follicle and can no longer mature into pigment cells. These cells are important in producing hair color, and if they cannot move to a different part of the follicle, they die sooner than other cells nearby, leading to gray hair. However, the study has found that these cells can move within the hair follicle without losing their “stemness” and can change back to more primitive stem cells. The process involves different compartments in the hair follicle, and a different environment in each location dictates how they change. The research has been performed in mice, but the findings could translate to humans. The study also has implications for melanoma, as melanomas develop from the same pigment cells as the McSCs. The findings suggest that melanocyte stem cells are “stranded” and not getting the right signal to amplify and migrate to provide pigment to the hair shaft. Researchers suggest that moving melanocytes to a proper location within the hair follicle may help prevent gray hair. However, the one question not answered in the study is how to reverse the dysfunction of the melanocyte stem cell “stuck” in the hair bulge. It could be challenging to provide stem cells with the right signals to keep them mobile and maturing, but understanding the underlying basic mechanism is the first step. It would also be interesting to see if other factors such as smoking and stress influence melanocyte stem cells in the same way.