Targeting human 8-oxoguanine glycosylase to mitochondria of oligodendrocytes protects against menadione-induced oxidative stress
Targeting human 8-oxoguanine glycosylase to mitochondria of oligodendrocytes protects against menadione-induced oxidative stress
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DOI：
10.1002/glia.10230
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发表时间：
2003-06-01
期刊：
影响因子：
6.2
通讯作者：
Ledoux, SP
中科院分区：
文献类型：
--
作者：
Druzhyna, NM;Hollensworth, SB;Ledoux, SP
在中枢神经系统（CNS）内，细胞类型对某些病理条件（据信涉及氧化应激）的敏感性不同。少突胶质细胞对氧化应激非常敏感，这与线粒体DNA（mtDNA）修复损伤的能力下降有关，正如我们以前所示。为了确定是否存在因果关系，进行了研究以纠正培养的少突胶质细胞中mtDNA氧化损伤修复的缺陷。将含有人8-氧代鸟嘌呤-DNA糖基化酶（OGG）序列上游的线粒体转运序列（MTS）的载体转染到细胞中。通过荧光显微镜和Western blot分析确定转染效率和重组蛋白的定位。随后的线粒体DNA修复研究，采用100 μ M甲萘醌产生活性氧，显示了一个显着的增强修复氧化损伤的MTS-OGG转染少突胶质细胞相比，细胞转染载体。实验还进行了确定改变线粒体DNA修复能力对甲萘醌诱导的少突胶质细胞凋亡的影响。这些实验表明，将OGG修复酶靶向线粒体减少了暴露于甲萘醌后少突胶质细胞中细胞色素c从线粒体间隙的释放和半胱天冬酶9的活化。因此，将DNA修复酶靶向线粒体似乎是保护细胞免受氧化应激的一些有害影响的可行方法。(C)2003 Wiley-Liss，Inc.
Within the central nervous system (CNS), there is a differential susceptibility among cell types to certain pathological conditions believed to involve oxidative stress. Oligodendrocytes are extremely sensitive to oxidative stress, which correlates with a decreased ability to repair damage in mitochondrial DNA (mtDNA), as we have shown previously. To determine whether there is a causal relationship, studies were carried out to correct the deficit in repair of the oxidative damage in mtDNA in cultured oligodendrocytes. A vector containing a mitochondrial transport sequence (MTS) upstream of the sequence for human 8-oxoguanine-DNA glycosylase (OGG) was transfected into the cells. The efficiency of transfection and the localization of recombinant protein were determined by fluorescence microscopy and by Western blot analysis. Subsequent mtDNA repair studies, employing 100 muM menadione to produce reactive oxygen species, showed a significant enhancement in repair of oxidative lesions in mtDNA of MTS-OGG transfected oligodendrocytes compared with cells transfected with vector only. Experiments were also conducted to determine the effect of changing mtDNA repair capacity on menadione-induced apoptosis in oligodendrocytes. These experiments show that targeting the OGG repair enzyme to mitochondria reduces the release of cytochrome c from the intermitochondrial space and the activation of caspase 9 in oligodendrocytes after exposure to menadione. Therefore, targeting of DNA repair enzymes to mitochondria appears to be a viable approach for the protection of cells against some of the deleterious effects of oxidative stress. (C) 2003 Wiley-Liss, Inc.