Bender J R, Sadeghi M M, Watson C, Pfau S, Pardi R
Boyer Center for Molecular Medicine, Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT 06536-0812.
Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3994-8. doi: 10.1073/pnas.91.9.3994.
It is well accepted that the induction of endothelial cell (EC) adhesion molecules is a critical component in acute inflammatory responses as well as allogeneic interactions in vascularized allografts and, possibly, atherogenesis. The "inflammatory triad" of interleukin 1 (IL-1), tumor necrosis factor, and lipopolysaccharide are potent stimulators of the EC activation/adhesion molecules intercellular adhesion molecule 1 (ICAM-1), endothelial-leukocyte adhesion molecule 1 (ELAM-1), and vascular cell adhesion molecule 1 (VCAM-1). To address whether there exist differing thresholds to cytokine-mediated EC activation, we utilized a panel of genetically distinct human umbilical vein EC lines, assessing their modulated EC surface expression and transcriptional responses to cytokines, with regard to the cell adhesion molecules (CAMs) ELAM-1, ICAM-1, and VCAM-1. With submaximal concentrations of cytokine, EC ELAM-1 surface expression varied from negligible to marked. This phenotypic response was maintained over numerous passages in culture and was observed in ex vivo organ culture analyses with cytokine-treated umbilical vein sections. Relative patterns of ELAM-1, ICAM-1, and VCAM-1 induction were similar in response to multiple stimuli (IL-1, tumor necrosis factor, and lipopolysaccharide, but not phorbol 12-myristate 13-acetate). Nuclear run-off experiments demonstrated that the "high responder" phenotype is a consequence of enhanced transcriptional activation of the CAM genes in response to IL-1 (1 unit/ml), whereas transcriptional responses in "low responders" are minimal. Despite the known involvement of NF-kappa B in endothelial CAM transcription, gel shift assays failed to demonstrate a correlation between the levels of IL-1-mediated nuclear NF-kappa B expression and CAM induction in high and low responding lines. We postulate that varying EC activation thresholds to cytokines observed here, in vitro, may be a critical determinant in the susceptibility to vasculopathic states.
内皮细胞（EC）黏附分子的诱导是急性炎症反应、血管化同种异体移植物中的同种异体相互作用以及可能的动脉粥样硬化形成的关键组成部分，这一点已得到广泛认可。白细胞介素1（IL-1）、肿瘤坏死因子和脂多糖组成的“炎症三联征”是EC激活/黏附分子细胞间黏附分子1（ICAM-1）、内皮细胞-白细胞黏附分子1（ELAM-1）和血管细胞黏附分子1（VCAM-1）的有效刺激物。为了探讨细胞因子介导的EC激活是否存在不同阈值，我们使用了一组基因不同的人脐静脉EC系，评估它们对细胞因子调节的EC表面表达和转录反应，涉及细胞黏附分子（CAMs）ELAM-1、ICAM-1和VCAM-1。在亚最大浓度的细胞因子作用下，EC ELAM-1表面表达从可忽略不计到显著变化。这种表型反应在培养的多个传代中得以维持，并且在细胞因子处理的脐静脉切片的体外器官培养分析中也观察到。ELAM-1、ICAM-1和VCAM-1诱导的相对模式在对多种刺激（IL-1、肿瘤坏死因子和脂多糖，但不包括佛波酯12-肉豆蔻酸酯13-乙酸酯）的反应中相似。核转录实验表明，“高反应者”表型是CAM基因对IL-1（1单位/毫升）反应时转录激活增强的结果，而“低反应者”的转录反应最小。尽管已知NF-κB参与内皮CAM转录，但凝胶迁移试验未能证明IL-1介导的核NF-κB表达水平与高反应和低反应系中的CAM诱导之间存在相关性。我们推测，这里在体外观察到的EC对细胞因子的不同激活阈值可能是血管病变状态易感性的关键决定因素。
