Lin Chao-Chieh, Lin Yi-Tzu, Chen Ssu-Yu, Setayeshpour Yasaman, Chen Yubin, Dunn Denise E, Nguyen Taylor, Mestre Alexander A, Banerjee Adrija, Guruprasad Lalitha, Soderblom Erik J, Zhang Guo-Fang, Lin Chen-Yong, Filonenko Valeriy, Jeong Suh Young, Floyd Scott R, Hayflick Susan J, Gout Ivan, Chi Jen-Tsan
Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, United States of America.
Department of Radiation Oncology, Duke University School of Medicine, Durham, United States of America.
J Clin Invest. 2025 Jul 22. doi: 10.1172/JCI190215.
The cystine-xCT transporter-glutathione (GSH)-GPX4 axis is the canonical pathway protecting cells from ferroptosis. While GPX4-targeting ferroptosis-inducing compounds (FINs) act independently of mitochondria, xCT-targeting FINs require mitochondrial lipid peroxidation, though the mechanism remains unclear. Since cysteine is also a precursor for coenzyme A (CoA) biosynthesis, here, we demonstrated that CoA supplementation selectively prevented ferroptosis triggered by xCT inhibition by regulating the mitochondrial thioredoxin system. Our data showed that CoA regulated the in vitro enzymatic activity of mitochondrial thioredoxin reductase (TXNRD2) by covalently modifying the thiol group of cysteine (CoAlation) on Cys-483. Replacing Cys-483 with alanine on TXNRD2 abolished its enzymatic activity and ability to protect cells against ferroptosis. Targeting xCT to limit cysteine import and, therefore, CoA biosynthesis reduced CoAlation on TXNRD2. Furthermore, the fibroblasts from patients with disrupted CoA metabolism demonstrated increased mitochondrial lipid peroxidation. In organotypic brain slice cultures, inhibition of CoA biosynthesis led to an oxidized thioredoxin system, increased mitochondrial lipid peroxidation, and loss of cell viability, which were all rescued by ferrostatin-1. These findings identified CoA-mediated post-translational modification to regulate the thioredoxin system as an alternative ferroptosis protection pathway with potential clinical relevance for patients with disrupted CoA metabolism.
胱氨酸-xCT转运蛋白-谷胱甘肽（GSH）-GPX4轴是保护细胞免受铁死亡的经典途径。虽然靶向GPX4的铁死亡诱导化合物（FINs）独立于线粒体发挥作用，但靶向xCT的FINs需要线粒体脂质过氧化，尽管其机制尚不清楚。由于半胱氨酸也是辅酶A（CoA）生物合成的前体，在此，我们证明补充CoA通过调节线粒体硫氧还蛋白系统选择性地预防了由xCT抑制引发的铁死亡。我们的数据表明，CoA通过共价修饰Cys-483上半胱氨酸的硫醇基团（CoAlation）来调节线粒体硫氧还蛋白还原酶（TXNRD2）的体外酶活性。将TXNRD2上的Cys-483替换为丙氨酸消除了其酶活性以及保护细胞免受铁死亡的能力。靶向xCT以限制半胱氨酸的导入，从而减少CoA生物合成，降低了TXNRD2上的CoAlation。此外，CoA代谢紊乱患者的成纤维细胞表现出线粒体脂质过氧化增加。在器官型脑片培养中，抑制CoA生物合成导致硫氧还蛋白系统氧化、线粒体脂质过氧化增加和细胞活力丧失，而铁抑素-1均可挽救这些情况。这些发现确定了CoA介导的翻译后修饰以调节硫氧还蛋白系统是一种替代性的铁死亡保护途径，对CoA代谢紊乱的患者具有潜在的临床意义。
