Juliette U Bertrand, Valérie Petit, Zackie Aktary, Pierre DE LA Grange, Nadav Elkoshi, Pierre Sohier, Véronique Delmas, Carmit Levy, Lionel Larue
Premature hair greying occurs due to the depletion of melanocyte stem cells (McSCs) in the hair follicle, which can be accelerated by stress caused by genetic or environmental factors. However, the connection between stress and McSC loss is not fully understood. MiRNAs are molecules that control gene expression by regulating mRNA stability and translation, and are produced by the enzyme Dicer, which is repressed under stress. Here, using two mouse genetic models and human and mouse cell lines, we found that the inactivation of Dicer in melanocytes leads to a misplacement of these cells within the hair follicle, resulting in a lack of melanin transfer to keratinocytes in the growing hair and the exhaustion of the McSC pool...
September 20, 2023: Journal of Investigative Dermatology