Xing Dongqi, Feng Wenguang, Miller Andrew P, Weathington Nathaniel M, Chen Yiu-Fai, Novak Lea, Blalock J Edwin, Oparil Suzanne
Department of Medicine, University of Alabama at Birmingham, UAB Station, Birmingham, AL 35294, USA.
Am J Physiol Heart Circ Physiol. 2007 Jun;292(6):H2607-12. doi: 10.1152/ajpheart.01107.2006. Epub 2007 Jan 19.
We have previously shown that 17beta-estradiol (E2) attenuates responses to endoluminal injury of the rat carotid artery, at least in part, by decreasing inflammatory mediator expression and neutrophil infiltration into the injured vessel, with a major effect on the neutrophil-specific chemokine cytokine-induced neutrophil chemoattractant (CINC)-2 beta. Current studies tested the hypothesis that activated rat aortic smooth muscle cells (RASMCs) express these same inflammatory mediators and induce neutrophil migration in vitro and that E2 inhibits these processes by an estrogen receptor (ER)-dependent mechanism. Quiescent RASMCs treated with E2, the ER alpha-selective agonist propyl pyrazole triol (PPT), the ER beta-selective agonist diarylpropiolnitrile (DPN), or vehicle for 24 h were stimulated with tumor necrosis factor (TNF)-alpha and processed for real-time RT-PCR, ELISA, or chemotaxis assays 6 h later. TNF-alpha stimulated and E2 attenuated mRNA expression of inflammatory mediators, including P-selectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, monocyte chemoattractant protein (MCP)-1, and CINC-2 beta. DPN dose dependently attenuated TNF-alpha-induced mRNA expression of CINC-2 beta, whereas PPT had no effect. The anti-inflammatory effects of DPN and E2 were blocked by the nonselective ER-inhibitor ICI-182,780. ELISA confirmed the TNF-alpha-induced increase and E2-induced inhibition of CINC-2 beta protein secretion. TNF-alpha treatment of RASMCs produced a twofold increase in neutrophil chemotactic activity of conditioned media; E2 and DPN treatment markedly inhibited this effect. E2 inhibits activated RASMC proinflammatory mediator expression and neutrophil chemotactic activity through an ER beta-dependent mechanism.
我们之前已经表明，17β-雌二醇（E2）至少部分地通过降低炎症介质表达以及中性粒细胞向受损血管的浸润，减轻大鼠颈动脉腔内损伤的反应，对中性粒细胞特异性趋化因子细胞因子诱导的中性粒细胞趋化因子（CINC）-2β有主要影响。当前研究检验了以下假设：活化的大鼠主动脉平滑肌细胞（RASMCs）表达这些相同的炎症介质并在体外诱导中性粒细胞迁移，且E2通过雌激素受体（ER）依赖性机制抑制这些过程。用E2、ERα选择性激动剂丙基吡唑三醇（PPT）、ERβ选择性激动剂二芳基丙炔腈（DPN）或溶剂处理静止的RASMCs 24小时，然后用肿瘤坏死因子（TNF）-α刺激，并在6小时后进行实时RT-PCR、ELISA或趋化性分析。TNF-α刺激且E2减弱了包括P-选择素、细胞间黏附分子（ICAM）-1、血管细胞黏附分子（VCAM）-1、单核细胞趋化蛋白（MCP）-1和CINC-2β在内的炎症介质的mRNA表达。DPN剂量依赖性地减弱TNF-α诱导的CINC-2β的mRNA表达，而PPT没有作用。DPN和E2的抗炎作用被非选择性ER抑制剂ICI-182,780阻断。ELISA证实了TNF-α诱导的CINC-2β蛋白分泌增加以及E2诱导的抑制作用。用TNF-α处理RASMCs使条件培养基的中性粒细胞趋化活性增加了两倍；E2和DPN处理显著抑制了这种作用。E2通过ERβ依赖性机制抑制活化的RASMC促炎介质表达和中性粒细胞趋化活性。
