Wouters Elien, Hudson Claire A, McArdle Craig A, Bernal Andrés López
University of Bristol, School of Clinical Sciences (Obstetrics and Gynaecology), Dorothy Hodgkin Building, Whitson Street, Bristol BS1 3NY, UK.
BMC Res Notes. 2014 Jun 10;7:357. doi: 10.1186/1756-0500-7-357.
Prostaglandins are important mediators of uterine contractility and cervical ripening during labour. Cyclooxygenase-2 (COX-2), also known as prostaglandin-endoperoxide synthase 2, is a rate limiting enzyme involved in the conversion of arachidonic acid into prostaglandins at parturition. In this paper, the pathways underlying agonist-induced cyclooxygenase-2 expression in human myometrial cells were studied.
Myometrial cells were stimulated with different agonists: oxytocin (OXT), epidermal growth factor (EGF), interleukin-1β (IL1β), and phorbol-12-myristate-13-acetate (PMA) alone and in the presence of specific signalling pathway inhibitors. The nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB) pathway was inhibited by means of the IKK-2 inhibitor TPCA-1. Signalling through extracellular signal-regulated kinases (ERK) was inhibited using the MEK1/2 inhibitor PD-184352. Bisindolylmaleimide-I was used to inhibit protein kinase C (PKC) signalling. COX-2 expression and ERK phosphorylation were measured using immunoblotting.OXT induced COX-2 expression by activating PKC and ERK. EGF increased COX-2 expression via stimulation of PKC, ERK and NFKB. As expected, the pro-inflammatory cytokine IL1β induced COX-2 expression by activating PKC- and NFKB-dependent pathways. Stimulation of PKC directly with PMA provoked strong COX-2 expression.
PKC plays a central role in OXT and EGF induced COX-2 expression in human myometrial cells. However, other pathways, notably ERK and NFKB are also involved to an extent which depends on the type of agonist used.
前列腺素是分娩期间子宫收缩和宫颈成熟的重要介质。环氧化酶-2（COX-2），也称为前列腺素内过氧化物合酶2，是一种限速酶，在分娩时参与花生四烯酸转化为前列腺素的过程。本文研究了激动剂诱导人子宫肌层细胞中环氧化酶-2表达的潜在途径。
用不同的激动剂刺激子宫肌层细胞：单独使用催产素（OXT）、表皮生长因子（EGF）、白细胞介素-1β（IL1β）和佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA），并在存在特定信号通路抑制剂的情况下进行刺激。通过IKK-2抑制剂TPCA-1抑制活化B细胞核因子κ-轻链增强子（NFKB）途径。使用MEK1/2抑制剂PD-184352抑制细胞外信号调节激酶（ERK）的信号传导。双吲哚马来酰亚胺-I用于抑制蛋白激酶C（PKC）信号传导。使用免疫印迹法测量COX-2表达和ERK磷酸化。OXT通过激活PKC和ERK诱导COX-2表达。EGF通过刺激PKC、ERK和NFKB增加COX-2表达。正如预期的那样，促炎细胞因子IL1β通过激活PKC和NFKB依赖性途径诱导COX-2表达。直接用PMA刺激PKC可引起强烈的COX-2表达。
PKC在OXT和EGF诱导人子宫肌层细胞COX-2表达中起核心作用。然而，其他途径，特别是ERK和NFKB也在一定程度上参与其中，这取决于所使用激动剂的类型。
