Trypanosoma cruzi Induces the Reactive Oxygen Species-PARP-1-RelA Pathway for Up-regulation of Cytokine Expression in Cardiomyocytes
Trypanosoma cruzi Induces the Reactive Oxygen Species-PARP-1-RelA Pathway for Up-regulation of Cytokine Expression in Cardiomyocytes
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DOI：
10.1074/jbc.m109.076984
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发表时间：
2010-04-09
影响因子：
4.8
通讯作者：
Garg, Nisha Jain
中科院分区：
文献类型：
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作者：
Ba, Xueqing;Gupta, Shivali;Garg, Nisha Jain
在这项研究中，我们证明，人类心肌细胞（AC 16）产生活性氧（ROS）和炎症细胞因子的克氏锥虫。ROS主要由线粒体产生，其中一些扩散到感染的心肌细胞的胞浆中。这些ROS导致8-羟基鸟嘌呤损伤和DNA片段化的增加，这表明PARP-1活化，这通过感染心肌细胞中PARP-1和其他蛋白质的聚（ADP-核糖）（PAR）修饰得到证明。苯基-α-叔丁基硝酮阻断感染心肌细胞中线粒体ROS（mtROS）形成、DNA损伤和PARP-1活化。进一步的抑制研究表明，ROS和PARP-1信号TNF-α和IL-1 β表达在感染的心肌细胞。ROS直接信号传导RelA（p65）的核转位、NF-κ B活化和细胞因子基因表达。PARP-1没有表现出与p65的直接相互作用，也没有信号表明其在感染的心肌细胞中易位到细胞核。相反，PARP-1促进了p65相互作用核蛋白的PAR修饰和NF-κ B转录复合物的组装。PJ 34（PARP-1抑制剂）也阻止线粒体聚（ADP-核糖基）化（PAR化）和ROS形成。我们的结论是T. cruzi介导的mtROS为感染的心肌细胞中PARP-1-NF-κ B活化和细胞因子基因表达提供主要刺激。线粒体膜的PAR修饰然后导致mtROS形成和DNA损伤/PARP-1活化的反馈循环。ROS通过直接调节胞质NF-κ B或通过PARP-1依赖性PAR修饰p65相互作用核蛋白，促进细胞因子基因表达。我们的研究结果表明，ROS和炎症反应之间的联系在心肌细胞感染T。cruzi和提供线索的持续炎症的病理机制在恰加斯病。
In this study, we demonstrate that human cardiomyocytes (AC16) produce reactive oxygen species (ROS) and inflammatory cytokines in response to Trypanosoma cruzi. ROS were primarily produced by mitochondria, some of which diffused to cytosol of infected cardiomyocytes. These ROS resulted in an increase in 8-hydroxyguanine lesions and DNA fragmentation that signaled PARP-1 activation evidenced by poly(ADP-ribose) ( PAR) modification of PARP-1 and other proteins in infected cardiomyocytes. Phenyl-alpha-tert-butylnitrone blocked the mitochondrial ROS (mtROS) formation, DNA damage, and PARP-1 activation in infected cardiomyocytes. Further inhibition studies demonstrated that ROS and PARP-1 signaled TNF-alpha and IL-1 beta expression in infected cardiomyocytes. ROS directly signaled the nuclear translocation of RelA (p65), NF-kappa B activation, and cytokine gene expression. PARP-1 exhibited no direct interaction with p65 and did not signal its translocation to nuclei in infected cardiomyocytes. Instead, PARP-1 contributed to PAR modification of p65-interacting nuclear proteins and assembly of the NF-kappa B transcription complex. PJ34 (PARP-1 inhibitor) also prevented mitochondrial poly(ADP-ribosyl)ation (PARylation) and ROS formation. We conclude that T. cruzimediated mtROS provide primary stimulus for PARP-1-NF-kappa B activation and cytokine gene expression in infected cardiomyocytes. PAR modification of mitochondrial membranes then results in a feedback cycle of mtROS formation and DNA damage/PARP-1 activation. ROS, either through direct modulation of cytosolic NF-kappa B, or via PARP-1-dependent PAR modification of p65-interacting nuclear proteins, contributes to cytokine gene expression. Our results demonstrate a link between ROS and inflammatory responses in cardiomyocytes infected by T. cruzi and provide a clue to the pathomechanism of sustained inflammation in Chagas disease.