If you’re wondering if pandemic hair loss is real, don’t worry. Researchers at Harvard University have identified a biological mechanism by which chronic stress impairs hair follicle stem cells, confirming long-standing observations that stress can lead to hair loss.
In a study on mice published in Nature, researchers found that key stress hormones cause hair follicle stem cells to enter an extended telogen phase without regenerating follicles or hair. Researchers have identified specific cell types and molecules responsible for relaying stress signals to stem cells, showing that this pathway may be a target to restore hair growth, says Jasika Lau, Harvard -Written in the Gazette.
“My lab is interested in understanding how stress affects stem cell biology and tissue biology. What happens to your skin and hair when you’re stressed? Part of the motivation is the fact that everyone has a story to share about what happens. As a skin stem cell biologist, I don’t have a satisfactory answer as to whether stress actually has an effect. And more importantly, if there is an impact, what is the mechanism?” said Ya Chie Hsu, Alvin & Esther Star Associate. . Professor of Stem Cell and Regenerative Biology at Harvard University and senior author of the study. “Skin provides a tractable and accessible system to deeply study this important question, and this study shows that stress actually delays stem cell activation and the frequency at which hair follicle stem cells regenerate tissue.” We found that it fundamentally changed the
Researchers studied a mouse model of chronic stress and found that hair follicle stem cells remain in a telogen phase for a very long time without regenerating tissue. Corticosterone, the major stress hormone produced by the adrenal glands, was upregulated by chronic stress. Giving mice corticosterone reproduced the effects of stress on stem cells. The corresponding hormone in humans is cortisol, which is also upregulated under stress and is often referred to as the “stress hormone.”
“These results suggest that elevated stress hormones actually have a negative effect on hair follicle stem cells,” Professor Hsu said. “But what really surprised us was when we discovered the source of the stress hormones.” Under normal conditions, hair follicle regeneration slows down over time, with a longer telogen phase as the animal ages. It will be. But when the researchers removed the stress hormones, the resting phase of the stem cells became extremely short, and the mice entered a constant anagen phase to regenerate hair follicles throughout their lives, even as they got older.
