Aldabbous Lulwah, Abdul-Salam Vahitha, McKinnon Tom, Duluc Lucie, Pepke-Zaba Joanna, Southwood Mark, Ainscough Alexander J, Hadinnapola Charaka, Wilkins Martin R, Toshner Mark, Wojciak-Stothard Beata
From the Department of Medicine, Centre for Pharmacology and Therapeutics (L.A., V.A.-S., L.D., A.J.A., M.R.W., B.W.-S.) and Centre for Haematology (T.M.K.), Experimental Medicine, Imperial College London, United Kingdom; and Pulmonary Vascular Diseases Unit, Papworth Hospital NHS Foundation Trust, Papworth Everard Cambridge, United Kingdom (J.P.-Z., M.S., C.H., M.T.).
Arterioscler Thromb Vasc Biol. 2016 Oct;36(10):2078-87. doi: 10.1161/ATVBAHA.116.307634. Epub 2016 Jul 28.
Inflammation and dysregulated angiogenesis are features of endothelial dysfunction in pulmonary hypertension. Neutrophil extracellular traps (NETs), produced by dying neutrophils, contribute to pathogenesis of numerous vascular disorders but their role in pulmonary hypertension has not been studied. We sought evidence of (NETs) formation in pulmonary hypertension and investigated the effect of NETs on endothelial function.
Plasma and lung tissues of patients with pulmonary hypertension were analyzed for NET markers. The effects of NETs on endothelial function were studied in vitro and in vivo. Patients with chronic thromboembolic pulmonary hypertension and idiopathic pulmonary hypertension showed elevated plasma levels of DNA, neutrophil elastase, and myeloperoxidase. NET-forming neutrophils and extensive areas of NETosis were found in the occlusive plexiform lesions and vascularized intrapulmonary thrombi. NETs induced nuclear factor κB-dependent endothelial angiogenesis in vitro and increased vascularization of matrigel plugs in vivo. Angiogenic responses were associated with increased release of matrix metalloproteinase-9, heparin-binding epidermal growth factor-like growth factor, latency-associated peptide of the transforming growth factor β1, and urokinase-type plasminogen activator, accompanied by increased endothelial permeability and cell motility. NETs-induced responses depended on myeloperoxidase/H2O2-dependent activation of Toll-like receptor 4/nuclear factor κB signaling. NETs stimulated the release of endothelin-1 in HPAECs (human pulmonary artery endothelial cells) and stimulated pulmonary smooth muscle cell proliferation in vitro.
We are the first to implicate NETs in angiogenesis and provide a functional link between NETs and inflammatory angiogenesis in vitro and in vivo. We demonstrate the potential pathological relevance of this in 2 diseases of disordered vascular homeostasis, pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.
炎症和血管生成失调是肺动脉高压中内皮功能障碍的特征。中性粒细胞胞外陷阱（NETs）由濒死的中性粒细胞产生，在多种血管疾病的发病机制中起作用，但它们在肺动脉高压中的作用尚未得到研究。我们寻找肺动脉高压中NETs形成的证据，并研究NETs对内皮功能的影响。
分析肺动脉高压患者的血浆和肺组织中的NET标志物。在体外和体内研究NETs对内皮功能的影响。慢性血栓栓塞性肺动脉高压和特发性肺动脉高压患者的血浆中DNA、中性粒细胞弹性蛋白酶和髓过氧化物酶水平升高。在闭塞性丛状病变和肺内血栓形成中发现了形成NET的中性粒细胞和广泛的NETosis区域。NETs在体外诱导核因子κB依赖性内皮血管生成，并在体内增加基质胶栓的血管化。血管生成反应与基质金属蛋白酶-9、肝素结合表皮生长因子样生长因子、转化生长因子β1的潜伏相关肽和尿激酶型纤溶酶原激活剂的释放增加有关，同时内皮通透性和细胞运动性增加。NETs诱导的反应依赖于髓过氧化物酶/H2O2依赖性激活Toll样受体4/核因子κB信号通路。NETs刺激人肺动脉内皮细胞（HPAECs）释放内皮素-1，并在体外刺激肺平滑肌细胞增殖。
我们首次证明NETs与血管生成有关，并在体外和体内提供了NETs与炎症性血管生成之间的功能联系。我们证明了这在两种血管稳态紊乱疾病，即肺动脉高压和慢性血栓栓塞性肺动脉高压中的潜在病理相关性。
