Role of oxidants in NF-kappa B activation and TNF-alpha gene transcription induced by hypoxia and endotoxin.
Role of oxidants in NF-kappa B activation and TNF-alpha gene transcription induced by hypoxia and endotoxin.
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发表时间：
2000
影响因子：
4.4
通讯作者：
N. Chandel;W. Trzyna;D. S. McClintock;P. Schumacker
中科院分区：
文献类型：
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作者：
N. Chandel;W. Trzyna;D. S. McClintock;P. Schumacker
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）和缺氧都会诱导 NF-κ B 激活和 TNF-α 基因转录。此外，缺氧会增强 LPS 对 TNF-α mRNA 的诱导。先前的报告表明，抗氧化剂会因 LPS 或缺氧而消除 NF-kappa B 激活，这表明活性氧 (ROS) 参与 NF-kappa B 激活。本研究测试了缺氧和 LPS 期间 NF-kappaB 激活和 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% O2) 会刺激 NF-kappa B 和 TNF-α 基因转录，并增加 ROS 的产生（通过鼠巨噬细胞 J774.1 细胞中氧化剂敏感染料 2',7'-二氯荧光素二乙酸酯测量）。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 的缺氧激活、TNF-α 基因转录，并增加了 ROS 水平。鱼藤酮是线粒体复合物 I 的抑制剂，可消除缺氧期间 ROS 信号的增加、NF-κ B 的激活和 TNF-α 基因转录。 LPS 刺激 J774.1 细胞中 NF-κ B 和 TNF-α 基因转录，但不刺激 ROS 生成。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-κB和TNF-α基因转录没有影响，表明LPS通过ROS独立机制激活NF-κB和TNF-α基因转录。这些结果表明，线粒体 ROS 是 NF-kappa B 的缺氧激活和 TNF-α 基因转录所必需的，但对于 NF-kappa B 的 LPS 激活则不是必需的。
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-kappaB activation and the increase in TNF-alpha mRNA levels during hypoxia and LPS. Our results indicate that hypoxia (1.5% O2) 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-alpha gene transcription, but not for the LPS activation of NF-kappa B.