Epidermal growth factor and interleukin-1β utilize divergent signaling pathways to synergistically upregulate cyclooxygenase-2 gene expression in human amnion-derived WISH cells
Epidermal growth factor and interleukin-1β utilize divergent signaling pathways to synergistically upregulate cyclooxygenase-2 gene expression in human amnion-derived WISH cells
复制标题
DOI：
10.1095/biolreprod.104.030841
复制
发表时间：
2004-12-01
影响因子：
3.6
通讯作者：
Kniss, DA
中科院分区：
文献类型：
--
作者：
Ackerman, VE;Rovin, BH;Kniss, DA
在人类分娩中，子宫强直性前列腺素(PGs)主要是通过子宫内组织中环氧合酶-2(COX-2[也称为前列腺素合成酶2])的表达增加而产生的。白细胞介素1(IL-1)和表皮生长因子(EGF)都是COX-2转录的诱导者，是随着妊娠的推进而积聚在羊水中的众多因素之一。先前的研究表明，EGF可以增强羊膜和羊膜源性细胞产生IL-1β驱动的前列腺素E(2)。为了明确这一观察的机制，我们假设EGF和IL-1β在调节COX-2基因表达方面可能表现出协同作用。在Wish细胞中，EGF和IL-1β的联合处理导致COX-2mRNA的增加大于单独使用其中任何一种药物的刺激。仅在含有核因子-kappaB(NFkappaB)调控元件报告质粒的细胞中，未观察到EGF对IL-1β诱导的反式激活的增强作用，但当COX-2基因5‘-启动子片段(-891/+9)存在时，EGF对IL-1β诱导的反式激活作用明显。这两种药物都瞬时激活了可能参与COX-2基因表达调控的多个信号通路的中间产物。26 S蛋白酶体抑制剂MG-132选择性地阻断IL-1β诱导的NFkappaB活化和COX-2mRNA表达。只有药物阻断p38丝裂原活化蛋白激酶才能消除EGF刺激后COX-2的表达。我们得出结论，EGF和IL-1β似乎通过不同的信号级联途径传递信号，导致COX-2基因表达。IL-1β主要利用NFkappaB途径，而EGF信号通路的范围更广，包括p38激酶。IL-1β和EGF之间的协同作用并不依赖于增强的NFkappaB功能，而是通过不同地使用COX-2启动子内的独立反应元件而发生的。
In human parturition, uterotonic prostaglandins (PGs) arise predominantly via increased expression of cyclooxygenase-2 (COX-2 [also known as prostaglandin synthase 2]) within intrauterine tissues. Interleukin-1 (IL-1) and epidermal growth factor (EGF), both inducers of COX-2 transcription, are among numerous factors that accumulate within amniotic fluid with advancing gestation. It was previously demonstrated that EGF could potentiate IL-1beta-driven PGE(2) production in amnion and amnion-derived (WISH) cells. To define the mechanism for this observation, we hypothesized that EGF and IL-1beta might exhibit synergism in regulating COX-2 gene expression. In WISH cells, combined treatment with EGF and IL-1beta resulted in a greater-than-additive increase in COX-2 mRNA relative to challenge with either agent independently. Augmentation of IL-1beta-induced transactivation by EGF was not observed in cells harboring reporter plasmids bearing nuclear factor-kappa B (NFkappaB) regulatory elements alone, but was evident when a fragment (-891/ +9) of the COX-2 gene 5'-promoter was present. Both agents transiently activated intermediates of multiple signaling pathways potentially involved in the regulation of COX-2 gene expression. The 26 S proteasome inhibitor, MG-132, selectively abrogated IL-1beta-driven NFkappaB activation and COX-2 mRNA expression. Only pharmacologic blockade of the p38 mitogen-activated protein kinase eliminated COX-2 expression following EGF stimulation. We conclude that EGF and IL-1beta appear to signal through different signaling cascades leading to COX-2 gene expression. IL-1beta employs the NFkappaB pathway predominantly, while the spectrum of EGF signaling is broader and includes p38 kinase. The synergism observed between IL-1beta and EGF does not rely on augmented NFkappaB function, but rather, occurs through differential use of independent response elements within the COX-2 promoter.