Changes in Characteristics of Murine Hair Follicles and Tissue Stem Cells Throughout Life

The study investigated age-related changes in murine hair follicles (HFs) and stem cells throughout the mouse's lifetime. By postnatal day 200 (P200), skin maturation is complete, and aging begins, marked by the appearance of curved HFs and hypopigmented hair bulbs, leading to increased white hairs. Keratin 15-positive keratinocyte stem cells maintain hair regeneration, while the low number of tyrosinase-related protein 2-positive melanocyte stem cells may contribute to aging characteristics. These findings offer insights into stem cell roles in hair regeneration and age-related hair changes, potentially applicable to humans.