Role of oxidants in NF-κB activation and TNF-α gene transcription induced by hypoxia and endotoxin
Role of oxidants in NF-κB activation and TNF-α gene transcription induced by hypoxia and endotoxin
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DOI：
10.4049/jimmunol.165.2.1013
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发表时间：
2000-07-15
影响因子：
4.4
通讯作者：
Schumacker, PT
中科院分区：
文献类型：
--
作者：
Chandel, NS;Trzyna, WC;Schumacker, PT
转录因子NF-κ B刺激促炎细胞因子包括TNF-α的转录，LPS（内毒素）和缺氧均诱导NF-κ B活化和TNF-α基因转录。此外，缺氧增强LPS对TNF-α mRNA的诱导。以前的报道表明，抗氧化剂消除NF-κ B B激活响应LPS或缺氧，这表明活性氧（ROS）参与NF-κ B激活。本研究测试了在缺氧和LPS期间NF-κ B活化和TNF-α mRNA水平增加是否需要线粒体ROS。我们的结果表明，缺氧（1.5%O-2）刺激NF-κ B和TNF-α基因转录，并增加ROS产生，如通过氧化剂敏感染料2 '，7'-二氯荧光素二乙酸酯在小鼠巨噬细胞J774.1中测量的。抗氧化剂N-乙酰半胱氨酸和吡咯烷二硫代氨基甲酸消除了NF-κ B B、TNF-α基因转录的缺氧激活和ROS水平的增加。鱼藤酮，一种线粒体复合物I的抑制剂，消除了缺氧过程中ROS信号的增加，NF-κ B B的激活和TNF-α基因的转录。在J774.1细胞中，LPS刺激NF-κ B B和TNF-α基因转录，但不刺激ROS产生。鱼藤酮、吡咯烷二硫代氨基甲酸和N-乙酰半胱氨酸对LPS刺激NF-κ B和TNF-α基因转录没有影响，表明LPS通过ROS非依赖性机制激活NF-κ B和TNF-α基因转录。这些结果表明，线粒体ROS是低氧激活NF-κ B B和TNF-LU基因转录所必需的，而不是LPS激活NF-κ B B所必需的。
The transcription factor NF-kappa B stimulates the transcription of proinflammatory cytokines including TNF-alpha, LPS (endotoxin) and hypoxia both induce NF-kappa B activation and TNF-alpha gene transcription. Furthermore, hypoxia augments LPS induction of TNF-alpha mRNA. Previous reports have indicated that antioxidants abolish NF-kappa B activation in response to LPS or hypoxia, which suggests that reactive oxygen species (ROS) are involved in NF-kappa B activation. This study tested whether mitochondrial ROS are required for both NF-kappa B activation and the increase in TNF-alpha mRNA levels during hypoxia and LPS, Our results indicate that hypoxia (1.5% O-2) stimulates NF-kappa B and TNF-alpha gene transcription and increases ROS generation as measured by the oxidant sensitive dye 2',7'-dichlorofluorescein diacetate in murine macrophage J774.1 cells. The antioxidants N-acetylcysteine and pyrrolidinedithiocarbamic acid abolished the hypoxic activation of NF-kappa B, TNF-alpha gene transcription, and increases in ROS levels. Rotenone, an inhibitor of mitochondrial complex I, abolished the increase in ROS signal, the activation of NF-kappa B, and TNF-alpha gene transcription during hypoxia. LPS stimulated NF-kappa B and TNF-alpha gene transcription but not ROS generation in J774.1 cells. Rotenone, pyrrolidinedithiocarbamic acid, and N-acetylcysteine had no effect on the LPS stimulation of NF-kappa B and TNF-alpha gene transcription, indicating that LPS activates NF-kappa B and TNF-alpha gene transcription through a ROS-independent mechanism. These results indicate that mitochondrial ROS are required for the hypoxic activation of NF-kappa B and TNF-LU gene transcription, but not for the LPS activation of NF-kappa B.