Human Hair Follicle and Epidermal Melanocytes Exhibit Striking Differences in Their Aging Profile Involving Catalase

The study revealed that human hair follicle melanocytes (HFMs) and epidermal melanocytes (EMs) aged differently, with HFMs showing a more significant decline in proliferation and tyrosinase expression. Catalase expression and activity, important for reducing oxidative stress, were markedly lower in older HFMs, indicating a higher vulnerability to oxidative damage, which may contribute to hair graying. The findings suggested that oxidative stress significantly influenced hair follicle aging and graying, with catalase playing a crucial role in this process.