研究發現壓力導「一夜」白頭的機制
作者：
小柯機器人發布時間：2020/1/28 22:51:14
美國哈佛大學Ya-Chieh Hsu研究組發現，交感神經的過度活化導致黑素細胞幹細胞的耗竭。相關論文2020年1月22日在線發表於《自然》。
研究人員發現，在小鼠中，急性應激會通過快速消耗黑素細胞幹細胞而導致毛髮變白。結合腎上腺切除術、去神經支配、化學遺傳學、細胞敲除以及在黑素細胞幹細胞中特異性敲除腎上腺素能受體，研究人員發現應激誘導的黑素細胞幹細胞的丟失與免疫攻擊或腎上腺應激激素無關。而是，毛髮變白是由支配黑素細胞幹細胞微環境的交感神經的激活引起的。在壓力條件下，這些交感神經的激活導致神經遞質去甲腎上腺素（也稱為去甲腎上腺素）的突然釋放。這會導致靜止的黑素細胞幹細胞迅速增殖，繼之以分化、遷移以及從微環境中永久枯竭。短暫抑制黑素細胞幹細胞的增殖可防止壓力誘導的毛髮白髮。這項研究表明，急性應激誘導的神經元活動可導致體幹細胞的快速和永久性喪失，並舉例說明了成體幹細胞的維持直接受生物整體生理狀態的影響。
據悉，經驗和軼事證據表明，壓力與加速的頭髮變白（無色素的頭髮形成）有關，但到目前為止，對此聯繫的科學驗證很少。
附：英文原文
Title: Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells
Author: Bing Zhang, Sai Ma, Inbal Rachmin, Megan He, Pankaj Baral, Sekyu Choi, William A. Gonalves, Yulia Shwartz, Eva M. Fast, Yiqun Su, Leonard I. Zon, Aviv Regev, Jason D. Buenrostro, Thiago M. Cunha, Isaac M. Chiu, David E. Fisher, Ya-Chieh Hsu
Issue&Volume: 2020-01-22
Abstract: Empirical and anecdotal evidence has associated stress with accelerated hair greying (formation of unpigmented hairs)1,2, but so far there has been little scientific validation of this link. Here we report that, in mice, acute stress leads to hair greying through the fast depletion of melanocyte stem cells. Using a combination of adrenalectomy, denervation, chemogenetics3,4, cell ablation and knockout of the adrenergic receptor specifically in melanocyte stem cells, we find that the stress-induced loss of melanocyte stem cells is independent of immune attack or adrenal stress hormones. Instead, hair greying results from activation of the sympathetic nerves that innervate the melanocyte stem-cell niche. Under conditions of stress, the activation of these sympathetic nerves leads to burst release of the neurotransmitter noradrenaline (also known as norepinephrine). This causes quiescent melanocyte stem cells to proliferate rapidly, and is followed by their differentiation, migration and permanent depletion from the niche. Transient suppression of the proliferation of melanocyte stem cells prevents stress-induced hair greying. Our study demonstrates that neuronal activity that is induced by acute stress can drive a rapid and permanent loss of somatic stem cells, and illustrates an example in which the maintenance of somatic stem cells is directly influenced by the overall physiological state of the organism.
DOI: 10.1038/s41586-020-1935-3
Source: https://www.nature.com/articles/s41586-020-1935-3