Hepatitis C virus core protein inhibits mitochondrial electron transport and increases reactive oxygen species (ROS) production
Hepatitis C virus core protein inhibits mitochondrial electron transport and increases reactive oxygen species (ROS) production
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DOI：
10.1074/jbc.m506412200
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发表时间：
2005-11-11
影响因子：
4.8
通讯作者：
Weinman, SA
中科院分区：
文献类型：
--
作者：
Korenaga, M;Wang, T;Weinman, SA
丙型肝炎感染导致慢性氧化应激状态，这可能导致肝脏纤维化和癌变。以前的研究表明，在肝癌细胞中表达HCV核心蛋白使线粒体去极化并增加活性氧（ROS）的产生，但这些作用的机制尚不清楚。在这项研究中，我们研究了肝线粒体的性质，从转基因小鼠表达HCV核心蛋白，并从正常肝线粒体与重组核心蛋白孵育。来自表达HCV蛋白核心、E1和E2的转基因小鼠的肝线粒体显示谷胱甘肽池的氧化和NADPH含量的降低。此外，电子传递复合物I的活性降低，复合物I底物的ROS产生增加。复合体II或复合体III功能未观察到异常。孵育控制线粒体在体外与重组核心蛋白也引起谷胱甘肽氧化，选择性复合物I抑制，并增加ROS的产生。用蛋白酶K消化转基因线粒体或与核心蛋白一起孵育的对照线粒体表明，核心蛋白与线粒体强烈相关，保持与外膜相关，并且不跨外膜被吸收。核心蛋白也增加了Ca ~（2+）摄取到分离的线粒体。这些结果表明，核心蛋白与线粒体的相互作用以及随后谷胱甘肽池的氧化和复合物I抑制可能是慢性丙型肝炎中观察到的氧化应激的重要原因。
Hepatitis C infection causes a state of chronic oxidative stress, which may contribute to fibrosis and carcinogenesis in the liver. Previous studies have shown that expression of the HCV core protein in hepatoma cells depolarized mitochondria and increased reactive oxygen species (ROS) production, but the mechanisms of these effects are unknown. In this study we examined the properties of liver mitochondria from transgenic mice expressing HCV core protein, and from normal liver mitochondria incubated with recombinant core protein. Liver mitochondria from transgenic mice expressing the HCV proteins core, E1 and E2 demonstrated oxidation of the glutathione pool and a decrease in NADPH content. In addition, there was reduced activity of electron transport complex I, and increased ROS production from complex I substrates. There were no abnormalities observed in complex II or complex III function. Incubation of control mitochondria in vitro with recombinant core protein also caused glutathione oxidation, selective complex I inhibition, and increased ROS production. Proteinase K digestion of either transgenic mitochondria or control mitochondria incubated with core protein showed that core protein associates strongly with mitochondria, remains associated with the outer membrane, and is not taken up across the outer membrane. Core protein also increased Ca2+ uptake into isolated mitochondria. These results suggest that interaction of core protein with mitochondria and subsequent oxidation of the glutathione pool and complex I inhibition may be an important cause of the oxidative stress seen in chronic hepatitis C.