Oxidative stress mediates tumor necrosis factor-α-induced mitochondrial DNA damage and dysfunction in cardiac myocytes
Oxidative stress mediates tumor necrosis factor-α-induced mitochondrial DNA damage and dysfunction in cardiac myocytes
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DOI：
10.1161/01.cir.0000055318.09997.1f
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发表时间：
2003-03-18
期刊：
影响因子：
37.8
通讯作者：
Takeshita, A
中科院分区：
文献类型：
--
作者：
Suematsu, N;Tsutsui, H;Takeshita, A
背景-肿瘤坏死因子-α (TNF-α) 和血管紧张素 II (Ang II) 与心力衰竭的发生和进一步进展有关，这可能至少部分是由活性氧 (ROS) 的产生介导的。然而，心肌细胞中这种激动剂介导的 ROS 产生的原因和后果尚未明确。最近，我们证明了 ROS 产生的增加与衰竭心脏中线粒体 DNA (mtDNA) 损伤和功能障碍有关。因此，我们研究了心肌细胞在体外直接暴露于 TNF-α 和 Ang II 是否会通过产生 ROS 来诱导 mtDNA 损伤。 方法和结果 - 1 小时后，通过 2',7'-二氯荧光素二乙酸酯荧光显微镜评估，TNF-α 增加了培养的新生大鼠心室肌细胞内 ROS 的产生。通过 Southern blot 分析，TNF-α 还降低了与复合物 III 活性相关的 mtDNA 拷贝数，而抗氧化剂 α-生育酚的存在可以防止这种情况发生。心肌细胞直接暴露于 H2O2 会导致线粒体 DNA 拷贝数类似的减少。相比之下，Ang II 并不影响 mtDNA 拷贝数，尽管 ROS 产量也有类似的增加。鞘磷脂酶抑制剂 D609 可以抑制 TNF-α 介导的 ROS 产生和 mtDNA 拷贝数的减少。此外，N-乙酰鞘氨醇（C2-神经酰胺）是一种合成的细胞渗透性神经酰胺类似物，可增加心肌细胞ROS的产生，表明TNF-α介导的ROS产生和随后的mtDNA损伤是由鞘磷脂-神经酰胺信号通路介导的。结论-TNF-α、ROS和mtDNA损伤之间的密切联系可能发挥着重要作用。 在心肌重构和衰竭中发挥重要作用。
Background-Tumor necrosis factor-alpha (TNF-alpha) and angiotensin II (Ang II) are implicated in the development and further progression of heart failure, which might be, at least in part, mediated by the production of reactive oxygen species (ROS). However, the cause and consequences of this agonist-mediated ROS production in cardiac myocytes have not been well defined. Recently, we demonstrated that increased ROS production was associated with mitochondrial DNA (mtDNA) damage and dysfunction in failing hearts. We thus investigated whether the direct exposure of cardiac myocytes to TNF-alpha and Ang II in vitro could induce mtDNA damage via production of ROS.Methods and Results-TNF-alpha increased ROS production within cultured neonatal rat ventricular myocytes after 1 hour, as assessed by 2',7'-dichlorofluorescin diacetate fluorescence microscopy. TNF-alpha also decreased mtDNA copy number by Southern blot analysis in association with complex III activity, which was prevented in the presence of the antioxidant alpha-tocopherol. A direct exposure of myocytes to H2O2 caused a similar decrease in mtDNA copy number. In contrast, Ang II did not affect mtDNA copy number, despite the similar increase in ROS production. TNF-alpha-mediated ROS production and a decrease in mtDNA copy number were inhibited by the sphingomyelinase inhibitor D609. Furthermore, N-acetylsphingosine (C2-ceramide), a synthetic cell-permeable ceramide analogue, increased myocyte ROS production, suggesting that TNF-alpha-mediated ROS production and subsequent mtDNA damage were mediated by the sphingomyelin-ceramide signaling pathway.Conclusions-The intimate link between TNF-alpha, ROS, and mtDNA damage might play an important role in myocardial remodeling and failure.