Increased expression of DRAM1 confers myocardial protection against ischemia via restoring autophagy flux
Increased expression of DRAM1 confers myocardial protection against ischemia via restoring autophagy flux
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DRAM1 表达增加通过恢复自噬流赋予心肌抗缺血保护作用
DOI：
10.1016/j.yjmcc.2018.08.018
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发表时间：
2018
影响因子：
5
通讯作者：
ong
中科院分区：
文献类型：
--
作者：
Wu Xiaoqian;Qin Yuyan;Zhu Xiaoyan;Liu Dajun;Chen Fajiang;Xu Suowen;Zheng Dechong;Zhou You;Luo Ji;ong
研究背景DRAM 1（Damage-regulated autophagy modulator 1）是介导自噬体与溶酶体相互作用的最重要的溶酶体膜蛋白。我们的目的是调查是否有助于急性心肌梗死（AMI）后的心脏重塑和潜在的mechanism.Methods和resultsAdenovirus harboring DRAM 1被注射在梗死周围区的大鼠模型AMI实验产生永久结扎左前降支（LAD）冠状动脉。增加DRAM 1表达可保护心肌细胞免受缺血应激诱导的自噬通量障碍，改善AMI后心脏预后。DRAM 1过表达可明显抑制自噬底物蛋白、LC 3 II和p62/SQSTM 1在体内和体外的积聚。携带mRFP-GFP-LC 3的腺病毒显示，DRAM 1过表达通过增强自噬体向自噬溶酶体的转化来恢复自噬通量。在体外和体内，尽管DRAM 1过表达上调Atg 12 mRNA，但游离Atg 12蛋白减少，同时Atg 12-Atg 5结合物增加。有趣的是，免疫沉淀试验表明，DRAM 1与Atg 7相互作用，但不直接与Atg 5或Atg 12相互作用。值得注意的是，DRAM 1对自噬流量和心肌细胞保护的效果可以减轻Atg 7 siRNA.ConclusionsOur结果表明，DRAM 1保护心肌细胞免受缺血应激诱导的自噬流量障碍，并揭示了一种新的DRAM 1-Atg 7-Atg 12/Atg 5自噬流量调节途径在心肌缺血应激条件下。
BackgroundDRAM1 (Damage-regulated autophagy modulator 1) was reported as one of the most important lysosome membrane protein that mediates the interaction between autophagosome and lysosome. Our aim was to investigate whether DRAM1 contributes to cardiac remodeling after acute myocardial infarction (AMI) and the underlying mechanisms.Methods and resultsAdenovirus harboring DRAM1 was injected in the peri-infarct zone in a rat model of AMI experimentally produced by permanent ligation of left anterior descending (LAD) coronary artery. Increased DRAM1 expression protected the cardiomyocytes from ischemia stress-induced autophagy flux obstacle and improved cardiac prognosis after AMI. DRAM1 overexpression attenuated the accumulation of autophagy substrate protein, LC3IIand p62/SQSTM1 obviously bothin vivoandin vitro. An adenovirus harboring mRFP-GFP-LC3 showed that DRAM1 overexpression restored the autophagic flux by enhancing autophagosome conversion to autophagolysosome. Although Atg12 mRNA was up-regulated with DRAM1 overexpression the free Atg12 protein was decreased accompanied by increased Atg12-Atg5 conjugate bothin vitroandin vivo. Of interest, immunoprecipitation assay showed that DRAM1 interacted with Atg7, but without direct interaction with Atg5 or Atg12. Notably, the effect of DRAM1 on autophagy flux and cardiomyocyte protection could be mitigated by Atg7 siRNA.ConclusionsOur results indicated that DRAM1 protected cardiomyocytes from ischemia stress-induced autophagy flux obstacle and uncovered a novel DRAM1-Atg7-Atg12/Atg5 autophagy flux regulation pathway under conditions of myocardial ischemic stress.