Redox Homeostasis is Disturbed by Redox Cycling between Reactive Cysteines of Thioredoxin 1 and 9,10-Phenanthrenequinone, an Atmospheric Electron Acceptor
Redox Homeostasis is Disturbed by Redox Cycling between Reactive Cysteines of Thioredoxin 1 and 9,10-Phenanthrenequinone, an Atmospheric Electron Acceptor
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硫氧还蛋白 1 的反应性半胱氨酸与大气电子受体 9,10-菲醌之间的氧化还原循环扰乱了氧化还原稳态
DOI：
10.1021/acs.chemrestox.2c00174
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发表时间：
2022
影响因子：
4.1
通讯作者：
Kumagai Yoshito
中科院分区：
文献类型：
--
作者：
Abiko Yumi;Taguchi Keiko;Hisamori Miwa;Hiyoshi-Arai Kyoko;Luong Nho Cong;Toriba Akira;Kumagai Yoshito
9，10-菲醌(9，10-PQ)是柴油机尾气颗粒物和空气中可吸入颗粒物≤中的一种有毒物质，直径2.5μm。它是一种高效的电子受体，在体外很容易与二硫醇化合物反应，导致硫醇基团的氧化并伴随着活性氧物种(ROS)的生成。然而，9，10-PQ是否与近端蛋白二硫醇相互作用尚不清楚。在本研究中，我们使用硫氧还蛋白1(Trx1)作为蛋白质与活性近端半胱氨酸的模型，并检测它是否与细胞和组织中的9，10-PQ反应，从而影响其催化活性和硫醇状态。气管内注射9，10-PQ可导致小鼠肺内蛋白质氧化和Trx活性降低。利用重组野生型和C32S/C35S Trx1，我们发现Cys32和Cys35选择性地作为9，10-PQ氧化还原反应的电子供体，导致Trx活性的显著抑制。加入二硫苏糖醇可恢复9，10-PQ抑制的TRX活性。培养细胞暴露于9，10-PQ可导致细胞内产生活性氧，导致蛋白质氧化、Trx1二聚化、p38磷酸化和细胞凋亡。Trx1的过表达阻断了这些9，10-PQ介导的事件。这些结果表明，Trx1的反应性半胱氨酸与9，10-PQ的相互作用导致氧化应激，导致氧化还原动态平衡的破坏。
9,10-Phenanthrenequinone (9,10-PQ) is a toxicant in diesel exhaust particles and airborne particulate matter ≤2.5 μm in diameter. It is an efficient electron acceptor that readily reacts with dithiol compoundsin vitro, resulting in the oxidation of thiol groups and concomitant generation of reactive oxygen species (ROS). However, it remains to be elucidated whether 9,10-PQ interacts with proximal protein dithiols. In the present study, we used thioredoxin 1 (Trx1) as a model of proteins with reactive proximal cysteines and examined whether it reacts with 9,10-PQ in cells and tissues, thereby affecting its catalytic activity and thiol status. Intratracheal injection of 9,10-PQ into mice resulted in protein oxidation and diminished Trx activity in the lungs. Using recombinant wild-type and C32S/C35S Trx1, we found that Cys32 and Cys35 selectively serve as electron donor sites for redox reactions with 9,10-PQ that lead to substantial inhibition of Trx activity. Addition of dithiothreitol restored the Trx activity inhibited by 9,10-PQ. Exposure of cultured cells to 9,10-PQ caused intracellular reactive oxygen species generation that led to protein oxidation, Trx1 dimerization, p38 phosphorylation, and apoptotic cell death. Overexpression of Trx1 blocked these 9,10-PQ-mediated events. These results suggest that the interaction of the reactive cysteines of Trx1 with 9,10-PQ causes oxidative stress, leading to disruption of redox homeostasis.