Metformin-Enhanced Cardiac AMP-Activated Protein Kinase/Atrogin-1 Pathways Inhibit Charged Multivesicular Body Protein 2B Accumulation in Ischemia-Reperfusion Injury.
Metformin-Enhanced Cardiac AMP-Activated Protein Kinase/Atrogin-1 Pathways Inhibit Charged Multivesicular Body Protein 2B Accumulation in Ischemia-Reperfusion Injury.
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二甲双胍增强心脏 AMPK/Atrogin-1 通路，防止 CHMP2B 积累，对抗缺血再灌注损伤
DOI：
10.3389/fcell.2020.621509
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发表时间：
2020
影响因子：
5.5
通讯作者：
Ma H
中科院分区：
文献类型：
--
作者：
Li T;Yin Y;Mu N;Wang Y;Liu M;Chen M;Jiang W;Yu L;Li Y;Ma H
背景：心肌缺血/再灌注(MI/R)时心脏自噬流量受损。自噬通量受损可能加重MI/R损伤。带电多囊泡体蛋白2B(CHMP2B)是运输所需的内体分选复合体(ESCRT-III)的一个亚单位，是自噬所必需的。然而，CHMP2B积聚在自噬和MI/R损伤中的逆转作用尚未确定。本文旨在阐明AMP激活的蛋白激酶(AMPK)/阿托金-1通路在抑制CHMP2B在缺血再灌注损伤中的作用。方法：采用雄性C57BL/6小鼠(3~4月龄)和H9c2心肌细胞，分别在体内和体外观察心肌缺血/再灌注和缺氧/复氧损伤。左开胸建立MI/R模型，阻断左前降支。H9c2细胞首先在95%N_2和5%CO_2中处理15h，然后复氧1h，然后给小鼠注射二甲双胍(100 mg/kg/d)和CHMP2B(Ad-CHMP2B)转染腺病毒。H9c2细胞分别用二甲双胍(2.5 mM)、MG-132(10μM)、巴菲罗星A1(10 NM)和化合物C(20μM)处理。结果：H/R处理的心肌细胞和MI/R小鼠的自噬通量受到抑制，心肌CHMP2B积聚增加。体内和体外实验表明，上调CHMP2B水平可抑制自噬通量，导致H/R心肌细胞恶化和MI/R损伤。这一发现表明CHMP2B积聚增加了心肌缺血的风险。二甲双胍通过激活AMPK抑制CHMP2B蓄积，改善H/R诱导的自噬功能障碍。激活的AMPK上调了心肌中肌特异性泛素连接酶阿托金-1的信使RNA表达和蛋白水平。Atrogin-1显著增强阿托金-1与CHMP2B之间的相互作用，从而促进CHMP2B在MI/R心肌中的降解。最后，本研究揭示了二甲双胍抑制CHMP2B蓄积导致体内自噬损伤和缺血易感性是通过AMPK调节阿托金-1对CHMP2B的降解实现的。结论：体内和体外CHMP2B清除受损可抑制自噬流量，降低心肌缺血耐受性。二甲双胍通过AMPK-阿托金-1依赖的途径降解CHMP2B，以维持自噬通量的动态平衡。这是一种新的机制，丰富了对心脏保护的理解。
Background: Cardiac autophagic flux is impaired during myocardial ischemia/reperfusion (MI/R). Impaired autophagic flux may exacerbate MI/R injury. Charged multivesicular body protein 2B (CHMP2B) is a subunit of the endosomal sorting complex required for transport (ESCRT-III) complex that is required for autophagy. However, the reverse role of CHMP2B accumulation in autophagy and MI/R injury has not been established. The objective of this article is to elucidate the roles of AMP-activated protein kinase (AMPK)/atrogin-1 pathways in inhibiting CHMP2B accumulation in ischemia–reperfusion injury. Methods: Male C57BL/6 mice (3–4 months) and H9c2 cardiomyocytes were used to evaluate MI/R and hypoxia/reoxygenation (H/R) injury in vivo and in vitro, respectively. MI/R was built by a left lateral thoracotomy and occluded the left anterior descending artery. H9c2 cells were firstly treated in 95% N2 and 5% CO2 for 15 h and reoxygenation for 1 h. Metformin (100 mg/kg/d) and CHMP2B (Ad-CHMP2B) transfected adenoviruses were administered to the mice. The H9c2 cells were treated with metformin (2.5 mM), MG-132 (10 μM), bafilomycin A1 (10 nM), and compound C (20 μM). Results: Autophagic flux was found to be inhibited in H/R-treated cardiomyocytes and MI/R mice, with elevated cardiac CHMP2B accumulation. Upregulated CHMP2B levels in the in vivo and in vitro experiments were shown to inhibit autophagic flux leading to the deterioration of H/R-cardiomyocytes and MI/R injury. This finding implies that CHMP2B accumulation increases the risk of myocardial ischemia. Metformin suppressed CHMP2B accumulation and ameliorated H/R-induced autophagic dysfunction by activating AMPK. Activated AMPK upregulated the messenger RNA expression and protein levels of atrogin-1, a muscle-specific ubiquitin ligase, in the myocardium. Atrogin-1 significantly enhanced the interaction between atrogin-1 and CHMP2B, therefore, promoting CHMP2B degradation in the MI/R myocardium. Finally, this study revealed that metformin-inhibited CHMP2B accumulation induced autophagic impairment and ischemic susceptibility in vivo through the AMPK-regulated CHMP2B degradation by atrogin-1. Conclusion: Impaired CHMP2B clearance in vitro and in vivo inhibits autophagic flux and weakens the myocardial ischemic tolerance. Metformin treatment degrades CHMP2B through the AMPK-atrogin-1-dependent pathway to maintain the homeostasis of autophagic flux. This is a novel mechanism that enriches the understanding of cardioprotection.
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DOI：
10.1016/s0140-6736(18)32203-7
发表时间：
2018-11-10
期刊：
Lancet (London, England)
影响因子：
--
作者：
GBD 2017 Causes of Death Collaborators
通讯作者：
GBD 2017 Causes of Death Collaborators
影响因子：
2.9
作者：
Krasniak, Christopher S.;Ahmad, S. Tariq
通讯作者：
Ahmad, S. Tariq
抑制动力相关蛋白 1 可预防糖尿病小鼠心肌缺血再灌注损伤
影响因子：
9.3
作者：
Ding M;Dong Q;Liu Z;Liu Z;Qu Y;Li X;Huo C;Jia X;Fu F;Wang X
通讯作者：
Wang X
影响因子：
5
作者：
Shimizu, Yuuki;Lambert, Jonathan P.;Nicholson, Chad K.;Kim, Joshua J.;Wolfson, David W.;Cho, Hee Cheol;Husain, Ahsan;Naqvi, Nawazish;Chin, Li-Shen;Li, Lian;Calvert, John W.
通讯作者：
Calvert, John W.
影响因子：
3.7
作者：
Hao, Rui;Su, Guoying;Su, Guohai
通讯作者：
Su, Guohai