中文摘要：

探讨多壁碳纳米管对人肺上皮细胞A549核转录因子-κB（NF-κB）活性的影响及其活化机制.不同浓度的多壁碳纳米管作用于A549细胞后,用活性氧（ROS）敏感探针2′,7′-二氯荧光素二乙酸酯结合流式细胞仪检测细胞内氧化应激状态;用凝胶电泳迁移率改变这一分析技术检测A549细胞NF-κB DNA结合活性;用蛋白印迹检测A549细胞NF-κB p65蛋白和IκBα蛋白表达;用免疫荧光结合共聚焦显微镜观察A549细胞NF-κB p65蛋白的核转位情况.结果表明,多壁碳纳米管诱导A549细胞内ROS过量产生和NF-κB DNA结合活性;同时伴有p65蛋白核移位和IκBα蛋白胞浆降解.抗氧化剂N-乙酰半胱氨酸（NAC）可抑制多壁碳纳米管诱导的A549细胞内ROS产生、NF-κB DNA结合活性、p65蛋白核移位以及IκBα蛋白降解.结果表明,多壁碳纳米管可以通过诱导A549细胞氧化应激机制从而活化核转录因子NF-κB活性.

英文摘要：

The present study was undertaken to examine the effects of multi-walled carbon nanotubes（MWCNTs） on nuclear factor（NF）-κB activation in human A549 lung epithelial cells.Cultured A549 cells were stimulated with various concentrations of MWCNTs in the presence or absence of antioxidants.The intracellular generation of reactive oxygen species（ROS） was detected by means of flow cytometry analysis with a redox-sensitive fluorescent probe 2′,7′-dichlorfluorescein-diacetate.NF-κB activity was measured by electrophoretic mobility shift assay（EMSA）.The protein levels of p65 and IκBα were assessed by Western blot analysis.Translocation of p65 into the nucleus was examined by immunofluorescence confocal microscopy.The results showed increased ROS and NF-κB activity in response to treatment of A549 cells with MWCNTs.MWCNTs stimulated nuclear translocation of the p65 subunit of NF-κB,IκBα phosphorylation in A549 cells.Treatment of A549 cells with antioxidants prior to adding MWCNTs resulted in a significant reduction in ROS generation,NF-κB activity,p65 translocation and IκBα phosphorylation in A549 cells.These results indicate that MWCNTs are able to induce NF-κB activation in A549 cells mediated by oxidative stress.