Rahman A, Kefer J, Bando M, Niles W D, Malik A B
Department of Pharmacology, College of Medicine, The University of Illinois, Chicago, Illinois 60612, USA.
Am J Physiol. 1998 Sep;275(3):L533-44. doi: 10.1152/ajplung.1998.275.3.L533.
Because reactive oxygen species (ROS) can function as second messengers and regulate the activation of the transcription factor nuclear factor (NF)-kappaB, we investigated the possible role of tumor necrosis factor-alpha (TNF-alpha)-induced ROS generation in endothelial cells in signaling E-selectin gene transcription. We demonstrated that stimulation of human pulmonary artery endothelial cells with TNF-alpha (100 U/ml) resulted in ROS production using the oxidant-sensitive dye 5 (and 6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate bis(acetoxymethyl)ester. Pretreatment with N-acetyl-L-cysteine (NAC) or pyrrolidine dithiocarbamate (PDTC) for 0.5 h inhibited TNF-alpha-induced generation of ROS as well as activation of NF-kappaB and E-selectin mRNA and the cell surface protein expression. These findings indicate that TNF-alpha induces NF-kappaB activation and the resultant E-selectin gene expression by a pathway that involves formation of ROS and that E-selectin expression can be inhibited by the antioxidant action of NAC or PDTC. The results support the hypothesis that generation of ROS in endothelial cells induced by proinflammatory cytokines such as TNF-alpha is a critical signal mediating E-selectin expression.
由于活性氧（ROS）可作为第二信使并调节转录因子核因子（NF）-κB的激活，我们研究了肿瘤坏死因子-α（TNF-α）诱导的ROS生成在内皮细胞中对E-选择素基因转录信号传导的可能作用。我们证明，用TNF-α（100 U/ml）刺激人肺动脉内皮细胞会导致使用氧化敏感染料5（和6）-羧基-2'，7'-二氯二氢荧光素二乙酸双（乙酰氧基甲基）酯产生ROS。用N-乙酰-L-半胱氨酸（NAC）或吡咯烷二硫代氨基甲酸盐（PDTC）预处理0.5小时可抑制TNF-α诱导的ROS生成以及NF-κB的激活、E-选择素mRNA和细胞表面蛋白表达。这些发现表明，TNF-α通过涉及ROS形成的途径诱导NF-κB激活以及随后的E-选择素基因表达，并且E-选择素表达可被NAC或PDTC的抗氧化作用抑制。结果支持这样的假设，即由TNF-α等促炎细胞因子诱导的内皮细胞中ROS的生成是介导E-选择素表达的关键信号。
