A new study published in Nature Communications may shed light on one of the main causes of hair loss. Researchers at Duke‑NUS Medical School in Singapore have discovered that hair follicle stem cells—critical for hair regrowth—depend on a protective protein called MCL‑1 to survive and function. Without MCL‑1, these stem cells experience stress and eventually die, leading to hair thinning and baldness.
Previous research has shown that hair follicle stem cells can undergo apoptosis, or programmed cell death, when stressed by shrinking follicles or hair shaft loss, accelerating hair loss. The new study investigated how MCL‑1 supports the survival of these cells during the regeneration process.
The researchers conducted experiments on mice, switching off MCL‑1 either from birth or in adulthood after hair removal. They found that without MCL‑1, hair follicle stem cells died, preventing new hair from growing. Baby mice experienced gradual hair loss, while adult mice developed bald spots that failed to regrow.
“These findings demonstrate the pivotal role of MCL‑1 in inhibiting proliferation stress‑induced apoptosis when quiescent stem cells activate to fuel tissue regeneration,” the study noted.
Despite the promising findings, practical applications for human hair loss may face challenges. Dorothy Bennett, a professor of cell biology at St. George’s University of London, told BBC Science Focus that MCL‑1 is an intracellular protein, meaning it cannot easily be applied topically. “Even if we had a solution or ointment containing MCL‑1, it is very unlikely that the protein could penetrate cells in the scalp,” Bennett explained.
However, the research does suggest potential avenues for future treatment. The study highlighted the possibility of activating another protein that could increase MCL‑1 levels, providing a potential indirect method to protect hair follicle stem cells. While it may take significant work to translate these findings into human therapies, the discovery offers hope for more effective approaches to combating hair loss.
