gray hair

Gray hair is an inevitable part of aging. Melanocytes are the culprit cells that slow production of the color pigments called melanin, but how and why this occurs with age largely remains a mystery. Harris et al.make a link between the immune system and premature graying. They find that the protein MITF (microphthalmia-associated transcription factor), which controls melanocyte stem cell function, also works to trigger melanocyte immune responses. Interferons normally kickstart the immune response to viral and bacterial infection, but when MITF cannot regulate interferon, hair turns gray in mouse models. These findings may shed light on why chronic illness or certain autoimmune disorders can accelerate the graying process.