Ученые выявили механизм поседения волос: застревание стволовых клеток лишает волосы пигмента

Here’s what you’ll learn when you read this story: - A 2023 mouse study linked graying hair to melanocyte stem cells losing their unusual ability to move between compartments inside the hair follicle. - When too many of those cells become lodged in the follicle bulge, they may stop producing the pigment cells that give new hair its color. - New research keeps that mechanism in play, but cautions that no proven medical treatment reverses ordinary age-related gray hair in humans. If only our pesky stem cells didn’t get stuck in place after a while, maybe we wouldn’t have gray hair. Really. In a 2023 study published in the journal Nature, researchers from New York University’s Grossman School of Medicine examined melanocyte stem cells, or McSCs, the cells that help supply pigment-producing melanocytes. In mice, the team found that McSCs could become stranded in a part of the follicle where they no longer received the right cues to regenerate pigment cells. Using mice as the research subjects, the team found that McSCs travel between compartments of developing hair follicles in a healthy situation. The differing compartments allow the McSCs to mature and pick up the protein that can regenerate into pigment cells and continually color hair as it grows. These McSCs shift back and forth between maturity levels over time as they continually move between the compartments, a unique aspect of the McSCs. But in some cases, the McSCs can get stuck in the hair follicle bulge compartment and become unable to move back to the germ compartment, where the WNT proteins encourage the cells to regenerate into pigment cells. Getting stuck means no pigment cells, which means gray hair. “It is the loss of chameleon-like function in melanocyte stems cells that may be responsible for graying and loss of hair color,” Mayumi Ito, study senior investigator and professor in the Ronald O. Perelman Department of Dermatology and Department of Cell Biology at NYU Langone Health, said in a news release. “These findings suggest that melanocyte stem cell motility and reversible differentiation are key to keeping hair healthy and colored.” A 2026 review from the same NYU team found that hair graying is tied to more than cell position. The review points to DNA-repair decline, oxidative stress, senescence-associated processes, altered signaling, and the follicle niche itself. That’s a much harder biology problem than simply telling a stuck cell to move. Basically, if McSCs could be kept mobile, or nudged out of the bulge compartment after they stall, pigment production might restart. The study didn’t show that this can be done in people. “Our study adds to our basic understanding of how melanocyte stem cells work to color hair,” Qi Sun, of NYU Langone Health, said in the release. “The newfound mechanisms raise the possibility that the same fixed positioning of melanocyte stem cells may exist in humans. If so, it presents a potential pathway for reversing or preventing the graying of human hair by helping jammed cells to move again between developing hair follicle compartments.” The 2026 review stresses that mice and humans differ in lifespan, hair-cycle length, follicle architecture, and environmental exposure. Newer human single-cell work research some overlap with the mouse findings, including loss of melanocytes and matrix progenitors in graying human hairs, but that’s not the same as proving that the mouse traffic-jam mechanism can be reversed in an aging human scalp. McSCs focus on pigment-making, and are different from the cells responsible for hair growth, Sun says, so hair can continue growing even after it loses color. In the NYU mouse study, as the hair regrowth process aged, more McSCs became lodged in the follicle bulge. At some points, that non-pigment-producing follicle bulge contained roughly 50 percent of all McSCs. The McSCs that remained mobile retained their ability to produce pigment. The cells that lost that mobility were the problem. Stress still belongs in the larger gray-hair conversation, but the current field picture is broader: graying is tied to oxidative stress, melanocyte depletion, diminished pigmentation-related signaling, DNA-damage responses, and changes in the follicle niche. “For unknown reasons, the melanocyte stem cell system fails earlier than other adult stem cell populations, which leads to hair graying in most humans and mice,” according to the NYU study. Dermatologists aren’t treating ordinary gray hair as a solved problem. A 2026 expert Delphi consensus on hair aging says effective therapies to reverse graying are not yet available. The American Academy of Dermatology’s public guidance says much the same: at present, there are no effective medical treatments to add color back to gray hair, except in cases where graying is linked to an underlying reversible condition, such as a deficiency. The clinical pipeline is thin, too. A ClinicalTrials.gov study updated April 30, 2026 is recruiting participants to test cosmetic leave-on products for the appearance of gray hair. Another grey-hair treatment study, CS-002, involves an mTOR inhibitor, but its trial record still shows not yet recruiting, no posted results, and estimated completion dates in 2027. Neither study proves that ordinary age-related gray hair can be biologically reversed. As for the next step, researchers still need to show how much the fixed-positioning mechanism matters in human aging hair, whether McSC mobility can be restored safely, and whether that would actually bring pigment back in ordinary age-related graying. Tim Newcomb is a journalist based in the Pacific Northwest. He covers stadiums, sneakers, gear, infrastructure, and more for a variety of publications, including Popular Mechanics. His favorite interviews have included sit-downs with Roger Federer in Switzerland, Kobe Bryant in Los Angeles, and Tinker Hatfield in Portland.