Cyclooxygenase-2 induction by bradykinin in human pulmonary artery smooth muscle cells is mediated by the cyclic AMP response element through a novel autocrine loop involving endogenous prostaglandin E2, E-prostanoid 2 (EP2), and EP4 receptors
Cyclooxygenase-2 induction by bradykinin in human pulmonary artery smooth muscle cells is mediated by the cyclic AMP response element through a novel autocrine loop involving endogenous prostaglandin E2, E-prostanoid 2 (EP2), and EP4 receptors
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DOI：
10.1074/jbc.m307964200
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发表时间：
2003-12-12
影响因子：
4.8
通讯作者：
Knox, AJ
中科院分区：
文献类型：
--
作者：
Bradbury, DA;Newton, R;Knox, AJ
缓激肽(BK)是多种炎症和血管疾病的重要介质，部分通过诱导环氧合酶-2(COX-2)发挥作用。BK介导的COX-2诱导机制尚不清楚。在这里，我们描述了涉及人肺动脉平滑肌细胞的转录机制。BK刺激瞬时转染的966个碱基(-917到+49)的COX-2启动子荧光素酶报告载体的活性。在674、407、239和135bp的COX-2启动子构建体或CCAAT/增强子结合蛋白或核因子-kappaB结合位点突变的构建体中，BK诱导的荧光素酶活性没有降低。相反，在含有突变的cAMP反应元件(Cre)结合位点的407bpCOX-2启动子片段的细胞中，荧光素酶活性降低，这表明Cre结合位点是关键的。使用针对COX-2启动子Cre结合区的寡核苷酸和共有的寡核苷酸进行的凝胶迁移率改变分析表明，COX-2启动子的Cre结合区具有很强的特异性结合。此外，BK还增加了共识cAMP反应荧光素酶报告基因(p6CRE/Luc)介导的荧光素酶的表达。BK通过诱导胞浆磷脂酶A(2)介导的花生四烯酸释放和前列腺素E-2(PGE(2))的快速产生而激活Cre，从而增加cAMP。吲哚美辛可抑制BK诱导的PGE(2)生成、cAMP积聚、Cre/Luc报告基因和COX-2启动子荧光素酶活性。外源性PGE(2)和EP2(ONO-AE1259)和EP4(ONO-AE1329)PGE(2)受体激动剂模拟BK的作用。综上所述，这些研究表明，BK对人肺动脉平滑肌细胞COX-2的诱导是由Cre通过一个涉及内源性PGE的新的自分泌环路介导的(2)。
Bradykinin (BK) is an important mediator in several inflammatory and vascular diseases that acts in part via induction of cyclooxygenase-2 (COX-2). The mechanisms involved in BK-mediated COX-2 induction are unclear. Here we characterized the transcriptional mechanisms involved in human pulmonary artery smooth muscle cells. BK stimulated the activity of a transiently transfected 966-bp (-917 to +49) COX-2 promoter luciferase reporter construct. There was no reduction in BK-induced luciferase activity in cells transfected with COX-2 promoter constructs of 674, 407, 239, and 135 bp or constructs with mutated CCAAT/enhancer-binding protein- or NF-kappaB-binding sites. In contrast luciferase activity was reduced in cells transfected with a 407-bp COX-2 promoter fragment containing a mutated cAMP response element (CRE)-binding site, suggesting that the CRE binding site is critical. Electrophoretic mobility shift assays using oligonucleotides specific for the CRE-binding region of the COX-2 promoter and consensus oligonucleotides showed strong specific binding. Furthermore BK increased consensus cAMP-responsive luciferase reporter (p6CRE/luc)-mediated luciferase expression. CRE activation occurred by BK inducing cytosolic phospholipase A(2)-mediated arachidonic acid release and rapid prostaglandin E-2 (PGE(2)) production, thereby increasing cAMP. Indomethacin inhibited BK-induced PGE(2) production, cAMP accumulation, and CRE/luc reporter and COX-2 promoter luciferase activity. Exogenous PGE(2) and EP2 (ONO-AE1 259) and EP4 (ONO-AE1 329) PGE(2) receptor agonists mimicked the effect of BK. Collectively these studies indicate that COX-2 induction by BK in human pulmonary artery smooth muscle cells is mediated by the CRE through a novel autocrine loop involving endogenous PGE(2).