Orthner C L, Rodgers G M, Fitzgerald L A
Plasma Derivatives Laboratory, American Red Cross Holland Laboratory, Rockville, MD 20855, USA.
Blood. 1995 Jul 15;86(2):436-43.
Tissue factor (TF), a 46-kD glycoprotein receptor for coagulation factors VII and VIIa, is expressed on the surface of endothelial cells in response to a variety of agonists and is thought to play an important role in initiating the thrombosis associated with inflammation during infection, sepsis, and organ transplant rejection. The induction of TF activity by lipopolysaccharide (LPS) is regulated, at least partially, at a transcriptional level and an LPS response element containing two activator protein-1 sites and a nuclear factor-kappa B (NF kappa B)-like site has been localized to the 5' flanking region of the TF gene by transfection studies of TF promoter/reporter gene constructs. We have examined the effect of pyrrolidine dithiocarbamate (PDTC), a specific inhibitor of the NF kappa B pathway on the expression of the endogenous TF gene in human umbilical vein endothelial cells (HUVEC). Preincubation of HUVEC for 60 minutes with PDTC inhibited LPS induction of TF activity on the cell surface in a dose-dependent manner, with 50% inhibition occurring at 10 mumol/L PDTC and 100% inhibition at higher concentrations (> or = 100 mumol/L). Furthermore, PDTC inhibited TF expression in response to tumor necrosis factor-alpha, interleukin-1 beta, and phorbol 12-myristate 13-acetate. The effect of PDTC was at the mRNA level, as seen by the complete abrogation of the large increase in TF mRNA observed in LPS-treated HUVEC. These results suggest that endothelial cell activation by diverse agonists initiates intracellular signaling events that converge upon a common pathway involving NF kappa B and, furthermore, that NF kappa B activation is an obligatory step induction of TF.
组织因子（TF）是一种分子量为46 kD的凝血因子VII和VIIa的糖蛋白受体，在内皮细胞表面因多种激动剂而表达，被认为在感染、败血症和器官移植排斥反应期间引发与炎症相关的血栓形成中起重要作用。脂多糖（LPS）对TF活性的诱导至少部分在转录水平受到调控，通过TF启动子/报告基因构建体的转染研究，已将一个包含两个激活蛋白-1位点和一个核因子-κB（NF-κB）样位点的LPS反应元件定位到TF基因的5'侧翼区域。我们研究了NF-κB途径的特异性抑制剂吡咯烷二硫代氨基甲酸盐（PDTC）对人脐静脉内皮细胞（HUVEC）内源性TF基因表达的影响。用PDTC将HUVEC预孵育60分钟以剂量依赖性方式抑制细胞表面TF活性的LPS诱导，在10 μmol/L PDTC时出现50%抑制，在更高浓度（≥100 μmol/L）时出现100%抑制。此外，PDTC抑制对肿瘤坏死因子-α、白细胞介素-1β和佛波醇12-肉豆蔻酸酯13-乙酸酯的TF表达。如在LPS处理的HUVEC中观察到的TF mRNA大幅增加被完全消除所示，PDTC的作用在mRNA水平。这些结果表明，多种激动剂对内皮细胞的激活引发细胞内信号事件，这些事件汇聚到一条涉及NF-κB的共同途径，此外，NF-κB激活是TF诱导的一个必要步骤。
