伴侶蛋白介導的自噬調節胚胎幹細胞的多能性
作者:
小柯機器人發布時間:2020/7/25 12:14:45
美國賓夕法尼亞大學Xiaolu Yang研究組近日取得一項新成果。他們發現伴侶蛋白介導的自噬調節胚胎幹細胞的多能性。2020年7月24日出版的《科學》雜誌發表了這項成果。
他們顯示核心多能性因子OCT4和SOX2抑制伴侶介導的自噬(CMA),這是自噬的一種選擇性形式,持續到分化開始。低CMA活性促進胚胎幹細胞自我更新,而其上調則促進分化。CMA降解異檸檬酸脫氫酶IDH1和IDH2,並降低細胞內α-酮戊二酸水平,α-酮戊二酸是參與多能性的各種組蛋白和DNA去甲基酶的強制性輔因子。
這些發現表明,CMA介導了核心多能性因子對代謝的影響,塑造了幹細胞的表觀遺傳格局,並控制了自我更新與分化之間的平衡。
據悉,胚胎幹細胞可以以多能狀態無限期繁殖,當回復到胚胎時,能夠分化為所有類型的特化細胞。在繁殖過程中什麼維持它們的多能性還不清楚。
附:英文原文
Title: Chaperone-mediated autophagy regulates the pluripotency of embryonic stem cells
Author: Yi Xu, Yang Zhang, Juan C. García-Caaveras, Lili Guo, Mengyuan Kan, Sixiang Yu, Ian A. Blair, Joshua D. Rabinowitz, Xiaolu Yang
Issue&Volume: 2020/07/24
Abstract: Embryonic stem cells can propagate indefinitely in a pluripotent state, able to differentiate into all types of specialized cells when restored to the embryo. What sustains their pluripotency during propagation remains unclear. Here, we show that core pluripotency factors OCT4 and SOX2 suppress chaperone-mediated autophagy (CMA), a selective form of autophagy, until the initiation of differentiation. Low CMA activity promotes embryonic stem cell self-renewal, whereas its up-regulation enhances differentiation. CMA degrades isocitrate dehydrogenases IDH1 and IDH2 and reduces levels of intracellular α-ketoglutarate, an obligatory cofactor for various histone and DNA demethylases involved in pluripotency. These findings suggest that CMA mediates the effect of core pluripotency factors on metabolism, shaping the epigenetic landscape of stem cells and governing the balance between self-renewal and differentiation.
DOI: 10.1126/science.abb4467
Source: https://science.sciencemag.org/content/369/6502/397
Science:《科學》,創刊於1880年。隸屬於美國科學促進會,最新IF:41.037