Aging Hair Follicles Rejuvenated by Transplantation to a Young Subcutaneous Environment

The study demonstrated that transplanting aged hair follicles into young host mice rejuvenated the follicles and promoted hair shaft growth, unlike transplants into old host mice, which did not support hair growth. The activity of nestin-expressing hair follicle-associated pluripotent (HAP) stem cells remained high in young hosts but was reduced in old hosts. The research involved 4 groups of hair follicles (17-20 follicles per group) and suggested that the young subcutaneous environment could reverse aging in hair follicles, indicating that hair loss due to aging might be reversible. The findings highlighted the potential for using this model to test hair-growth promoting drugs and explore the role of stem cells and pharmaceutical interventions in rejuvenating aging hair follicles.