State Key Laboratory of Common Mechanism Research for Major Diseases, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China.
Department of Obstetrics and Gynecology, Maternal and Child Health Hospital of Qinhuangdao, Qinhuangdao, 066000, China.
Free Radic Biol Med. 2023 Oct;207:32-44. doi: 10.1016/j.freeradbiomed.2023.06.023. Epub 2023 Jul 5.
Mitochondria are vital for energy production and redox homeostasis, yet knowledge of relevant mechanisms remains limited. Here, through a genome-wide CRISPR-Cas9 knockout screening, we have identified DMT1 as a major regulator of mitochondria membrane potential. Our findings demonstrate that DMT1 deficiency increases the activity of mitochondrial complex I and reduces that of complex III. Enhanced complex I activity leads to increased NAD production, which activates IDH2 by promoting its deacetylation via SIRT3. This results in higher levels of NADPH and GSH, which improve antioxidant capacity during Erastin-induced ferroptosis. Meanwhile, loss of complex III activity impairs mitochondrial biogenesis and promotes mitophagy, contributing to suppression of ferroptosis. Thus, DMT1 differentially regulates activities of mitochondrial complex I and III to cooperatly suppress Erastin-induced ferroptosis. Furthermore, NMN, an alternative method of increasing mitochondrial NAD, exhibits similar protective effects against ferroptosis by boosting GSH in a manner similar to DMT1 deficiency, shedding a light on potential therapeutic strategy for ferroptosis-related pathologies.
线粒体对于能量产生和氧化还原平衡至关重要,但相关机制的知识仍然有限。在这里,我们通过全基因组 CRISPR-Cas9 敲除筛选,鉴定出 DMT1 是线粒体膜电位的主要调节因子。我们的研究结果表明,DMT1 缺乏会增加线粒体复合物 I 的活性,降低复合物 III 的活性。增强的复合物 I 活性导致 NAD 的产生增加,通过 SIRT3 促进其去乙酰化来激活 IDH2。这导致 NADPH 和 GSH 的水平升高,从而在 Erastin 诱导的铁死亡过程中提高抗氧化能力。同时,复合物 III 活性的丧失会损害线粒体生物发生并促进线粒体自噬,从而抑制铁死亡。因此,DMT1 通过差异调节线粒体复合物 I 和 III 的活性来共同抑制 Erastin 诱导的铁死亡。此外,NMN(烟酰胺单核苷酸)作为增加线粒体 NAD 的替代方法,通过类似于 DMT1 缺乏的方式促进 GSH 的增加,对铁死亡表现出相似的保护作用,为铁死亡相关疾病的潜在治疗策略提供了启示。