Chadwick C C, Shaw L J, Winneker R C
Department of Reproductive Endocrinology, Women's Health Research Institute, Wyeth-Ayerst Research, Radnor, Pennsylvania 19087, USA.
Exp Cell Res. 1998 Mar 15;239(2):423-9. doi: 10.1006/excr.1997.3913.
TNF-alpha and 9-cis-retinoic acid (9-cis-R) synergistically enhance ICAM-1 protein expression in immortalized human aortic endothelial cells (HAECTs). At a TNF-alpha concentration of 0.1 ng/ml, 1 microM 9-cis-R enhanced ICAM-1 protein expression 4-fold. Treatment with 1 microM 9-cis-R alone caused no induction of ICAM-1 expression. Functional analysis of human ICAM-1 promoter-luciferase constructs revealed that the synergism was attributable to transcriptional regulation. Expression of a luciferase reporter vector containing a 311-bp fragment of the ICAM-1 promoter (-252 to + 59 bp relative to the transcriptional start site) was increased 2.9- and 4.9-fold by treatment with 9-cis-R and TNF-alpha, respectively, while cotreatment with 9-cis-R and TNF-alpha induced expression to 19.9-fold. Mutation studies revealed that RARE and NF-kappa B sites located respectively at -226 and -188 bp relative to the transcription start site are essential for the synergistic control of promoter activity. Mutation of either the RARE or the NF-kappa B site eliminated the synergistic enhancement of promoter activity. Moreover, mutation of the RARE abrogated promoter activity induced by treatment with TNF-alpha alone and mutation of the NF-kappa B site eliminated promoter activity induced by treatment with 9-cis-R alone. We conclude that retinoid receptors and NF-kappa B act in concert at the promoter level to facilitate ICAM-1 expression in endothelial cells.
肿瘤坏死因子-α（TNF-α）与9-顺式视黄酸（9-cis-R）协同增强永生化人主动脉内皮细胞（HAECTs）中细胞间黏附分子-1（ICAM-1）的蛋白表达。在TNF-α浓度为0.1 ng/ml时，1 μM 9-顺式视黄酸可使ICAM-1蛋白表达增强4倍。单独用1 μM 9-顺式视黄酸处理不会诱导ICAM-1表达。对人ICAM-1启动子-荧光素酶构建体的功能分析表明，这种协同作用归因于转录调控。用9-顺式视黄酸和TNF-α处理后，含有ICAM-1启动子311 bp片段（相对于转录起始位点为-252至+59 bp）的荧光素酶报告载体的表达分别增加了2.9倍和4.9倍，而9-顺式视黄酸与TNF-α共同处理可使表达增加至19.9倍。突变研究表明，相对于转录起始位点分别位于-226和-188 bp的视黄酸反应元件（RARE）和核因子-κB（NF-κB）位点对于启动子活性的协同控制至关重要。RARE或NF-κB位点的突变消除了启动子活性的协同增强。此外，RARE的突变消除了单独用TNF-α处理诱导的启动子活性，NF-κB位点的突变消除了单独用9-顺式视黄酸处理诱导的启动子活性。我们得出结论，类视黄醇受体和NF-κB在启动子水平协同作用，以促进内皮细胞中ICAM-1的表达。
