Influenza virus infection induces metallothionein gene expression in the mouse liver and lung by overlapping but distinct molecular mechanisms
Influenza virus infection induces metallothionein gene expression in the mouse liver and lung by overlapping but distinct molecular mechanisms
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DOI：
10.1128/mcb.21.24.8301-8317.2001
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发表时间：
2001-12-01
影响因子：
5.3
通讯作者：
Jacob, ST
中科院分区：
文献类型：
--
作者：
Ghoshal, K;Majumder, S;Jacob, ST
金属硫蛋白I （MT-1）和MT-H参与保护细胞免受活性氧（ROS）、重金属和各种病理和环境应激源的侵害。在这里，我们发现暴露于感染上呼吸道和肺部的流感a /PR8病毒的C57BL/6小鼠的肝脏和肺部的MT- i /MT- ii mRNA水平和MT蛋白显著增加。白细胞介素-6 （IL-6）在肝脏中对这些基因的诱导有明显的作用，但在肺中没有。用糖皮质激素受体拮抗剂RU-486处理动物，抑制了肝脏和肺部MT-I/MT-II的诱导，揭示了糖皮质激素在这一诱导过程中感染后增加的直接作用。体内基因组足迹（IVGF）分析表明，几乎所有的金属反应元件、主要晚期转录因子/抗氧化反应元件（MLTF/ARE）、MTI上游启动子上的STAT3结合位点以及MT-H基因上游的糖皮质激素反应元件（GRE1）都参与了肝脏和肺部的诱导过程。在肺中，在一个独特的γ干扰素（ifn - γ）反应元件（γ -IRE）和Sp1位点也发现了诱导足迹。迁移位移分析显示，肝和肺核提取物中STAT3和糖皮质激素受体被激活，这与IVGF的数据一致。通过实时荧光定量PCR对感染肺中新合成的细胞因子mRNA进行分析，发现IL-10和ifn - γ mRNA水平显著升高，分别可以激活STAT3和STAT1。在受感染的肺中激活了一种含有stat1的复合物，该复合物在体外与γ -IRE结合。感染后肝脏和肺部的MLTF/ARE DNA结合活性无明显变化。这些结果表明，MT-I和MT-II可以通过重叠但不同的分子机制在实验性流感病毒感染后的肝脏和肺中被强烈诱导。
Metallothionein I (MT-1) and MT-H have been implicated in the protection of cells against reactive oxygen species (ROS), heavy metals, and a variety of pathological and environmental stressors. Here, we show a robust increase in MT-I/MT-II mRNA level and MT proteins in the livers and lungs of C57BL/6 mice exposed to the influenza A/PR8 virus that infects the uppers respiratory tract and lungs. Interleukin-6 (IL-6) had a pronounced effect on the induction of these genes in the liver but not the lung. Treatment of the animals with RU-486, a glucocorticoid receptor antagonist, inhibited induction of MT-I/MT-II in both liver and lung, revealing a direct role of glucocorticoid that is increased upon infection in this induction process. In vivo genomic footprinting (IVGF) analysis demonstrated involvement of almost all metal response elements, major late transcription factor/antioxidant response element (MLTF/ARE), the STAT3 binding site on the MTI upstream promoter, and the glucocorticoid responsive element (GRE1), located upstream of the MT-H gene, in the induction process in the liver and lung. In the lung, inducible footprinting was also identified at a unique gamma interferon (IFN-gamma) response element (gamma -IRE) and at Sp1 sites. The mobility shift analysis showed activation of STAT3 and the glucocorticoid receptor in the liver and lung nuclear extracts, which was consistent with the IVGF data. Analysis of the newly synthesized mRNA for cytokines in the infected lung by real-time PCR showed a robust increase in the levels of IL-10 and IFN-gamma mRNA that can activate STAT3 and STAT1, respectively. A STAT1-containing complex that binds to the gamma -IRE in vitro was activated in the infected lung. No major change in MLTF/ARE DNA binding activity in the liver and lung occurred after infection. These results have demonstrated that MT-I and MT-II can be induced robustly in the liver and lung following experimental influenza virus infection by overlapping but distinct molecular mechanisms.