TLR9和Beclin 1協同調節運動時肌肉AMPK激活
作者:
小柯機器人發布時間:2020/2/14 15:17:55
2020年2月12日,美國德克薩斯大學西南醫學中心Beth Levine、Yang Liu等研究人員合作在《自然》發表論文。他們的最新工作發現,TLR9和Beclin 1協同調節運動時肌肉AMPK激活。
研究人員報導了先天性免疫感應分子Toll樣受體9(TLR9)及其與beclin 1的相互作用在運動誘導的骨骼肌AMPK激活中的作用。缺乏TLR9的小鼠在運動誘導的AMPK激活和骨骼肌GLUT4葡萄糖轉運蛋白的質膜定位方面均顯示出不足,但在自噬方面沒有缺陷。TLR9與beclin 1結合,這種相互作用因能量壓力(葡萄糖飢餓和耐力運動)而增加,而由於BCL2突變(阻止BCL2與beclin 1的結合)而減少。TLR9調節運動期間骨骼肌中的溶酶體磷脂醯肌醇3激酶複合物(PI3KC3-C2)的組裝,該複合物包含beclin 1和UVRAG,因此,敲除beclin 1或UVRAG會抑制葡萄糖飢餓誘導的細胞AMPK激活。此外,TLR9在體外收縮誘導的AMPK活化、葡萄糖攝取和Beclin 1-UVRAG複合物裝配中以肌肉自主方式發揮作用。這些發現揭示了運動過程中Toll樣受體在骨骼肌AMPK激活和葡萄糖代謝中的新作用,也揭示了先天免疫傳感器與自噬蛋白之間的新交流。
據了解,骨骼肌中AMPK的激活協調對運動的全身代謝反應。自噬是一種維持細胞穩態的溶酶體降解途徑,在運動過程中被上調,而核心自噬蛋白beclin 1是骨骼肌中AMPK激活所必需的。
附:英文原文
Title: TLR9 and beclin 1 crosstalk regulates muscle AMPK activation in exercise
Author: Yang Liu, Phong T. Nguyen, Xun Wang, Yuting Zhao, Corbin E. Meacham, Zhongju Zou, Bogdan Bordieanu, Manuel Johanns, Didier Vertommen, Tobias Wijshake, Herman May, Guanghua Xiao, Sanae Shoji-Kawata, Mark H. Rider, Sean J. Morrison, Prashant Mishra, Beth Levine
Issue&Volume: 2020-02-12
Abstract: The activation of adenosine monophosphate-activated protein kinase (AMPK) in skeletal muscle coordinates systemic metabolic responses to exercise1. Autophagy—a lysosomal degradation pathway that maintains cellular homeostasis2—is upregulated during exercise, and a core autophagy protein, beclin 1, is required for AMPK activation in skeletal muscle3. Here we describe a role for the innate immune-sensing molecule Toll-like receptor 9 (TLR9)4, and its interaction with beclin 1, in exercise-induced activation of AMPK in skeletal muscle. Mice that lack TLR9 are deficient in both exercise-induced activation of AMPK and plasma membrane localization of the GLUT4 glucose transporter in skeletal muscle, but are not deficient in autophagy. TLR9 binds beclin 1, and this interaction is increased by energy stress (glucose starvation and endurance exercise) and decreased by a BCL2 mutation3,5 that blocks the disruption of BCL2–beclin 1 binding. TLR9 regulates the assembly of the endolysosomal phosphatidylinositol 3-kinase complex (PI3KC3-C2)—which contains beclin 1 and UVRAG—in skeletal muscle during exercise, and knockout of beclin 1 or UVRAG inhibits the cellular AMPK activation induced by glucose starvation. Moreover, TLR9 functions in a muscle-autonomous fashion in ex vivo contraction-induced AMPK activation, glucose uptake and beclin 1–UVRAG complex assembly. These findings reveal a heretofore undescribed role for a Toll-like receptor in skeletal-muscle AMPK activation and glucose metabolism during exercise, as well as unexpected crosstalk between this innate immune sensor and autophagy proteins.
DOI: 10.1038/s41586-020-1992-7
Source: https://www.nature.com/articles/s41586-020-1992-7