Department of Stem Cell and Regenerative Biology, Harvard University and Harvard Stem Cell Institute, Cambridge, MA, USA.
Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China.
Exp Dermatol. 2021 Apr;30(4):572-577. doi: 10.1111/exd.14264. Epub 2020 Dec 31.
Stress is a risk factor for many skin conditions, but the cellular and molecular mechanisms of its impacts have only begun to be revealed. In mice, acute stress induces loss of melanocyte stem cells (MeSCs) and premature hair greying. Our previous work demonstrated that the loss of MeSCs upon acute stress is caused by the hyperactivation of the sympathetic nervous system. Stress also induces the secretion of stress hormones from the hypothalamic-pituitary-adrenal (HPA) axis; however, whether stress hormones are involved in the hair greying process has not been fully examined. In particular, the adrenocorticotropic hormone (ACTH) is released from the pituitary glands upon stress. ACTH is a ligand for the melanocortin 1 receptor (MC1R), which plays critical roles in regulating MeSC migration and skin pigmentation. We investigated whether the MC1R pathway is required for the stress-induced hair greying. We confirmed that MC1R is the major melanocortin receptor expressed in MeSCs. However, induction of acute stress via resiniferatoxin (RTX) injection still leads to hair greying in Mc1r mutant mice, suggesting that the ACTH-MC1R pathway is not a major contributor in acute stress-induced premature hair greying.
压力是许多皮肤状况的一个风险因素，但它的影响的细胞和分子机制才刚刚开始被揭示。在小鼠中，急性压力会导致黑素细胞干细胞（MeSCs）的丧失和过早的头发变白。我们之前的工作表明，急性压力下 MeSCs 的丧失是由于交感神经系统的过度激活所致。压力还会导致下丘脑-垂体-肾上腺（HPA）轴分泌应激激素；然而，应激激素是否参与了头发变白的过程尚未得到充分研究。特别是，促肾上腺皮质激素（ACTH）在应激时从垂体中释放。ACTH 是黑素皮质素 1 受体（MC1R）的配体，在调节 MeSC 迁移和皮肤色素沉着中发挥着关键作用。我们研究了 MC1R 途径是否是应激诱导的头发变白所必需的。我们证实 MC1R 是 MeSCs 中表达的主要黑素皮质素受体。然而，通过树脂毒素（RTX）注射诱导急性压力仍然会导致 Mc1r 突变小鼠的头发变白，这表明 ACTH-MC1R 途径不是急性压力诱导的过早头发变白的主要贡献者。
