Centre de Recherche en Cancérologie de l'Université Laval, Hôpital Hôtel-Dieu de Québec, Québec, Canada.
BMC Genomics. 2010 Feb 22;11:127. doi: 10.1186/1471-2164-11-127.
Werner Syndrome (WS) is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for WS encodes a DNA helicase/exonuclease protein believed to affect different aspects of transcription, replication, and/or DNA repair. In addition to genomic instability, human WS cells exhibit oxidative stress. In this report, we have examined the impact of exogenous hydrogen peroxide on the expression profile of mouse embryonic fibroblasts lacking part of the helicase domain of the WRN homologue (here referred to as Wrn Delta hel/Delta hel).
Wrn Delta hel/Delta hel mutant mouse embryonic fibroblasts exhibit increased oxidative stress. This was reflected by increased intracellular reactive oxygen species (ROS), increased oxidative damage in genomic DNA, changes in ATP/ADP ratios, and a disruption of the inner mitochondrial transmembrane potential when compared to wild type mouse embryonic fibroblasts. Expression profile analyses of hydrogen peroxide-treated wild type cells have indicated significant decreases in the expression of genes involved in mitosis, glycolysis, fatty acid metabolism, nucleic acid metabolism, and cell cycle control, as well as protein modification and stability. Such decreases in these biological processes were not observed in hydrogen peroxide-treated Wrn Delta hel/Delta hel cells. Importantly, untreated Wrn Delta hel/Delta hel cells already exhibited down regulation of several biological processes decreased in wild type cells that had been treated with hydrogen peroxide.
Expression profiling of Wrn Delta hel/Delta hel mutant cells revealed a very different response to exogenous addition of hydrogen peroxide in culture compared to wild type cells. This is due in part to the fact that Wrn Delta hel/Delta hel mutant cells already exhibited a modest chronic intracellular oxidative stress.
Werner 综合征（WS）是一种罕见的疾病，其特征是多种与年龄相关的疾病过早发作。负责 WS 的基因编码一种 DNA 解旋酶/核酸外切酶蛋白，据信该蛋白会影响转录、复制和/或 DNA 修复的不同方面。除了基因组不稳定外，人类 WS 细胞还表现出氧化应激。在本报告中，我们研究了外源性过氧化氢对缺失 WRN 同源物部分解旋酶结构域的小鼠胚胎成纤维细胞（在此称为 Wrn Delta hel/Delta hel）表达谱的影响。
Wrn Delta hel/Delta hel 突变型小鼠胚胎成纤维细胞表现出氧化应激增加。与野生型小鼠胚胎成纤维细胞相比，这表现在细胞内活性氧（ROS）增加、基因组 DNA 氧化损伤增加、ATP/ADP 比值变化以及线粒体内膜跨膜电位破坏。过氧化氢处理的野生型细胞的表达谱分析表明，参与有丝分裂、糖酵解、脂肪酸代谢、核酸代谢和细胞周期控制以及蛋白质修饰和稳定性的基因表达显著下降。在过氧化氢处理的 Wrn Delta hel/Delta hel 细胞中未观察到这些生物过程的这种减少。重要的是，未经处理的 Wrn Delta hel/Delta hel 细胞已经表现出几个生物过程的下调，而这些生物过程在经过氧化氢处理的野生型细胞中已经下调。
Wrn Delta hel/Delta hel 突变细胞的表达谱分析显示，与野生型细胞相比，培养中外源性添加过氧化氢会引起非常不同的反应。这部分归因于 Wrn Delta hel/Delta hel 突变细胞已经表现出适度的慢性细胞内氧化应激。
