Accumulation of 8-oxoguanine in the cellular DNA and the alteration of the OGG1 expression during ischemia-reperfusion injury in the rat kidney
Accumulation of 8-oxoguanine in the cellular DNA and the alteration of the OGG1 expression during ischemia-reperfusion injury in the rat kidney
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DOI：
10.1016/s1568-7864(02)00214-8
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发表时间：
2003-02-03
期刊：
影响因子：
3.8
通讯作者：
Nakabeppu, Y
中科院分区：
文献类型：
--
作者：
Tsuruya, K;Furuichi, M;Nakabeppu, Y
大鼠肾脏缺血再灌注（I/R）损伤期间，皮质髓质区和外髓质（OM）的远端肾小管出现细胞凋亡，而 OM 的近端直管出现严重坏死。这些变化大部分在两周内消失。我们检测了 I/R 损伤期间大鼠肾脏中 8-oxo-2'-脱氧鸟苷 (8-oxo-dG) 的含量，8-oxo-2'-脱氧鸟苷 (8-oxo-dG) 是 DNA 氧化损伤的主要类型，并研究了编码 8-氧鸟嘌呤 DNA 糖基化酶的 OGG1 基因的表达水平。高效液相色谱对核 DNA 进行 MS/MS 分析显示，I/R 后 1 小时，从肾脏皮质和 OM 制备的核 DNA 中立即积累了 8-oxo-dG，免疫组织化学分析表明，皮质和 OM 中的肾小管细胞核中立即积累了 8-oxo-dG。仅在皮质髓质和 OM 中观察到抗 8-oxo-dG 细胞质染色的延迟增加，其中近端肾小管细胞的细胞质染色高于远端肾小管细胞。线粒体 DNA 中代表 8-oxo-dG 的细胞质染色水平在 I/R 后达到峰值，并在 OM 中近端肾小管细胞坏死之前达到峰值。 RNase 保护测定显示，正常肾脏中 OGG1 mRNA 水平较高，仅在 OM 中，该水平在 3 小时内下降，而在 I/R 后 1-7 天，皮质和 OM 中的水平均有所增加。原位杂交显示，OM 肾小管中 OGG1 mRNA 表达水平高于正常肾皮质，且在 I/R 3 小时内迅速下降。因此，8-oxo-dG 在线粒体 DNA 中而不是在核 DNA 中的积累可能与肾脏 I/R 损伤期间肾小管细胞坏死等致病反应以及 OGG1 表达水平的改变有关。 (C) 2002 Elsevier Science B.V. 保留所有权利。
During ischemia-reperfusion (I/R) injury in the rat kidney, apoptosis was observed in the distal tubules of the cortico-medullary region and outer medulla (OM) while severe necrosis was seen in the proximal straight tubules of the OM. The majority of these changes disappeared within 2 weeks. We examined the contents of 8-oxo-2'-deoxyguanosine (8-oxo-dG), which is a major type of oxidative damage in DNA, in the rat kidney during I/R injury, and also investigated the expression level of the OGG1 gene encoding the 8-oxoguanine DNA glycosylase. High-performance liquid chromatography with an MS/MS analysis of the nuclear DNA revealed an immediate accumulation of 8-oxo-dG in the nuclear DNA prepared from the cortex and OM of the kidney 1 h after I/R, and an immunohistochemical analysis demonstrated the immediate accumulation of 8-oxo-dG in the nuclei of renal tubular cells both in the cortex and OM. A delayed increase of cytoplasmic staining with anti-8-oxo-dG was observed only in the cortico-medulla and OM, where the cytoplasmic staining in the proximal tubular cells is higher than in the distal tubular cells. The level of cytoplasmic staining representing 8-oxo-dG in mitochondrial DNA, peaked at 6 It after I/R and preceded the necrosis of proximal tubular cells in the OM. An RNase protection assay showed a high level of OGG1 mRNA in the normal kidney, and the level decreased within 3 h only in the OM, and increased thereafter 1-7 days of I/R both in the cortex and OM. In situ hybridization showed higher levels of OGG1 mRNA expression in the renal tubules in the OM than in the cortex of the normal kidney, which decreased rapidly within 3 h of I/R. Thus, the accumulation of 8-oxo-dG in the mitochondrial DNA rather than in nuclear DNA is likely to be involved in the pathogenic responses such as necrosis of renal tubular cells during I/R injury of the kidney, together with an altered level of OGG1 expression. (C) 2002 Elsevier Science B.V. All rights reserved.