Integrated Stress Response Couples Mitochondrial Protein Translation With Oxidative Stress Control.
Integrated Stress Response Couples Mitochondrial Protein Translation With Oxidative Stress Control.
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DOI：
10.1161/circulationaha.120.053125
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发表时间：
2021-11-02
期刊：
影响因子：
37.8
通讯作者：
Wang ZV
中科院分区：
文献类型：
--
作者：
Zhang G;Wang X;Li C;Li Q;An YA;Luo X;Deng Y;Gillette TG;Scherer PE;Wang ZV
综合应激反应（ISR）是一个进化上保守的过程，用于应对细胞内和细胞外的干扰。心肌梗塞是全世界死亡的主要原因。冠状动脉再灌注是减轻心肌梗死心脏损伤的最有效手段，但会造成额外的再灌注损伤。本研究旨在探讨 ISR 在心肌缺血/再灌注 (I/R) 中的作用。在体内采用了针对 ISR 的心脏特异性功能获得和丧失方法。通过结扎心脏左前降支45分钟，然后进行不同时间的再灌注来实现心肌I/R。通过超声心动图评估心脏功能。此外，还使用培养的 H9c2 细胞、原代大鼠心肌细胞和小鼠胚胎成纤维细胞来剖析潜在的分子机制。此外，还进行串联质量标签 (TMT) 标记和质谱分析来鉴定 ISR 的蛋白质靶点。测试了药理学手段来操纵 ISR 进行治疗探索。我们发现 ISR 的 PERK/eIF2α 轴在体内和体外均受到心肌细胞 I/R 的强烈诱导。我们进一步揭示了 PERK/eIF2α 信号传导的生理作用，表明心脏中 PERK 的急性激活可赋予针对再灌注损伤的强大心脏保护作用。相反，心脏特异性缺失 PERK 会加剧心脏对再灌注的反应。从机制上讲，ISR 通过翻译抑制直接靶向线粒体复合物。我们将线粒体复合物 I 的组装因子 NDUFAF2 确定为 PERK 的选择性靶标。 PERK 的过表达会抑制 NDUFAF2 的蛋白表达，而 PERK 的抑制会导致 NDUFAF2 的增加。 NDUFAF2 的沉默可显着挽救 I/R 下 PERK 敲低的心肌细胞的存活。此外，我们还发现，PERK/eIF2α 信号传导的激活可减少线粒体复合物衍生的活性氧，并提高心脏细胞对 I/R 的存活率。此外，即使在闭塞的冠状动脉恢复后，ISR的药物刺激也可以保护心脏免受再灌注损伤，这突出了心肌梗死治疗的临床相关性。这些研究表明，ISR 通过选择性抑制线粒体蛋白质合成和减少心脏氧化应激来提高细胞存活率并减轻再灌注损伤。
The integrated stress response (ISR) is an evolutionarily conserved process to cope with intracellular and extracellular disturbances. Myocardial infarction is a leading cause of death worldwide. Coronary artery reperfusion is the most effective means to mitigate cardiac damage of myocardial infarction, which however causes additional reperfusion injury. This study aimed to investigate the role of the ISR in myocardial ischemia/reperfusion (I/R). Cardiac-specific gain- and loss-of-function approaches for the ISR were employed in vivo. Myocardial I/R was achieved by the ligation of the cardiac left anterior descending artery for 45 minutes, followed by reperfusion for different times. Cardiac function was assessed by echocardiography. Additionally, cultured H9c2 cells, primary rat cardiomyocytes, and mouse embryonic fibroblasts were used to dissect underlying molecular mechanisms. Moreover, tandem mass tag (TMT) labeling and mass spectrometry was conducted to identify protein targets of the ISR. Pharmacological means were tested to manipulate the ISR for therapeutic exploration. We show that the PERK/eIF2α axis of the ISR is strongly induced by I/R in cardiomyocytes in vitro and in vivo. We further reveal a physiological role of PERK/eIF2α signaling by showing that acute activation of PERK in the heart confers robust cardioprotection against reperfusion injury. In contrast, cardiac-specific deletion of PERK aggravates cardiac responses to reperfusion. Mechanistically, the ISR directly targets mitochondrial complexes via translational suppression. We identify NDUFAF2, an assembly factor of mitochondrial complex I, as a selective target of PERK. Overexpression of PERK suppresses the protein expression of NDUFAF2 while PERK inhibition causes an increase of NDUFAF2. Silencing of NDUFAF2 significantly rescues cardiac cell survival from PERK knockdown under I/R. Further, we show that activation of PERK/eIF2α signaling reduces mitochondrial complex-derived reactive oxygen species and improves cardiac cell survival in response to I/R. Moreover, pharmacological stimulation of the ISR protects the heart against reperfusion damage, even after the restoration of occluded coronary artery, highlighting a clinical relevance for myocardial infarction treatment. These studies suggest that the ISR improves cell survival and mitigate reperfusion damage by selectively suppressing mitochondrial protein synthesis and reducing oxidative stress in the heart.