MITOL/MARCH5 determines the susceptibility of cardiomyocytes to doxorubicin-induced ferroptosis by regulating GSH homeostasis
MITOL/MARCH5 determines the susceptibility of cardiomyocytes to doxorubicin-induced ferroptosis by regulating GSH homeostasis
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DOI：
10.1016/j.yjmcc.2021.08.006
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发表时间：
2021-08-20
影响因子：
5
通讯作者：
Sano, Motoaki
中科院分区：
文献类型：
--
作者：
Kitakata, Hiroki;Endo, Jin;Sano, Motoaki
MITOL/MARCH 5是一种E3泛素连接酶，在线粒体质量和功能的控制中发挥关键作用。然而，MITOL在生理和病理条件下心肌细胞中的意义仍不清楚。首先，为了确定MITOL在非应激心脏中的意义，我们评估了新生大鼠原代心室心肌细胞（NRVM）中通过siRNA降低MITOL表达的细胞变化。NRVM中的MITOL敲低通过铁凋亡诱导细胞死亡，铁凋亡是一种新定义的非凋亡程序性细胞死亡，即使在无应激条件下也是如此。这种现象仅在NRVM中观察到，而在其他细胞类型中未观察到。MITOL敲除显著减少了线粒体定位的GPX 4，这是一种与铁凋亡相关的关键酶，促进了脂质过氧化物在线粒体中的积累。相反，在MITOL敲低细胞中GPX 4的激活抑制脂质过氧化和细胞死亡。MITOL敲低降低了调节GPX 4表达的谷胱甘肽/氧化型谷胱甘肽（GSH/GSSG）比率。事实上，GSH或N-乙酰半胱氨酸的施用改善了MITOL敲低的NRVM中GPX 4的表达和活力。MITOL敲低增加了谷胱甘肽降解酶ChaC谷胱甘肽特异性γ-谷氨酰环转移酶1（Chac 1）的表达。Chac 1的敲除恢复了MITOL敲除NRVM中的GSH/GSSG比率、GPX 4表达和活力。此外，在用DOX应激的培养心肌细胞中，MITOL和GPX 4均减少，而MITOL的强制表达通过维持GPX 4含量来抑制DOX诱导的铁凋亡。此外，MITOL敲除使对DOX的脆弱性恶化，其几乎完全通过用ferrostatin-1（一种铁凋亡抑制剂）治疗来挽救。在体内，心肌特异性的MITOL耗竭没有产生明显的异常，但增加了对DOX毒性的敏感性。最后，在MITOL敲除心脏中，ferrostatin-1的施用抑制了DOX诱导的心肌损伤的恶化。目前的研究表明，MITOL通过铁凋亡过程决定心肌细胞的细胞命运，并在调节对DOX治疗的脆弱性方面发挥关键作用。(288/300）
MITOL/MARCH5 is an E3 ubiquitin ligase that plays a crucial role in the control of mitochondrial quality and function. However, the significance of MITOL in cardiomyocytes under physiological and pathological conditions remains unclear. First, to determine the significance of MITOL in unstressed hearts, we assessed the cellular changes with the reduction of MITOL expression by siRNA in neonatal rat primary ventricular cardiomyocytes (NRVMs). MITOL knockdown in NRVMs induced cell death via ferroptosis, a newly defined non-apoptotic programmed cell death, even under no stress conditions. This phenomenon was observed only in NRVMs, not in other cell types. MITOL knockdown markedly reduced mitochondria-localized GPX4, a key enzyme associated with ferroptosis, pro-moting accumulation of lipid peroxides in mitochondria. In contrast, the activation of GPX4 in MITOL knock -down cells suppressed lipid peroxidation and cell death. MITOL knockdown reduced the glutathione/oxidized glutathione (GSH/GSSG) ratio that regulated GPX4 expression. Indeed, the administration of GSH or N-ace-tylcysteine improved the expression of GPX4 and viability in MITOL-knockdown NRVMs. MITOL-knockdown increased the expression of the glutathione-degrading enzyme, ChaC glutathione-specific gamma-glutamylcyclo-transferase 1 (Chac1). The knockdown of Chac1 restored the GSH/GSSG ratio, GPX4 expression, and viability in MITOL-knockdown NRVMs. Further, in cultured cardiomyocytes stressed with DOX, both MITOL and GPX4 were reduced, whereas forced-expression of MITOL suppressed DOX-induced ferroptosis by maintaining GPX4 content. Additionally, MITOL knockdown worsened vulnerability to DOX, which was almost completely rescued by treatment with ferrostatin-1, a ferroptosis inhibitor. In vivo, cardiac-specific depletion of MITOL did not produce obvious abnormality, but enhanced susceptibility to DOX toxicity. Finally, administration of ferrostatin-1 suppressed exacerbation of DOX-induced myocardial damage in MITOL-knockout hearts. The present study demonstrates that MITOL determines the cell fate of cardiomyocytes via the ferroptosis process and plays a key role in regulating vulnerability to DOX treatment. (288/300)