Laboratory for Thrombosis Research, KU Leuven, Campus Kulak Kortrijk, Kortrijk, Belgium.
Department of Medical Imaging, AZ Groeninge, Kortrijk, Belgium.
Ann Neurol. 2017 Aug;82(2):223-232. doi: 10.1002/ana.24993. Epub 2017 Aug 11.
Neutrophil extracellular traps (NETs) have been shown to promote thrombus formation. Little is known about the exact composition of thrombi that cause ischemic stroke. In particular, no information is yet available on the presence of NETs in cerebral occlusions. Such information is, however, essential to improve current thrombolytic therapy with tissue plasminogen activator (t-PA). This study aimed at investigating the presence of neutrophils and more specifically NETs in ischemic stroke thrombi.
Sixty-eight thrombi retrieved from ischemic stroke patients undergoing endovascular treatment were characterized by immunostaining using neutrophil markers (CD66b and neutrophil elastase) and NET markers (citrullinated histone H3 [H3Cit] and extracellular DNA). Neutrophils and NETs were quantified. In addition, extracellular DNA was targeted by performing ex vivo lysis of retrieved thrombi with DNase 1 and t-PA.
Neutrophils were detected extensively throughout all thrombi. H3Cit, a hallmark of NETs, was observed in almost all thrombi. H3Cit-positive area varied up to 13.45% of total thrombus area. Colocalization of H3Cit with extracellular DNA released from neutrophils confirmed the specific presence of NETs. H3Cit was more abundant in thrombi of cardioembolic origin compared to other etiologies. Older thrombi contained significantly more neutrophils and H3Cit compared to fresh thrombi. Interestingly, ex vivo lysis of patient thrombi was more successful when adding DNase 1 to standard t-PA.
Neutrophils and NETs form important constituents of cerebral thrombi. Targeting of NETs with DNase 1 might have prothrombolytic potential in treatment of acute ischemic stroke. Ann Neurol 2017;82:223-232.
已证实中性粒细胞胞外诱捕网（NETs）可促进血栓形成。然而，对于导致缺血性脑卒中的血栓的确切成分知之甚少。特别是，目前尚无关于脑梗死中存在 NETs 的信息。然而，这些信息对于改善目前用组织型纤溶酶原激活剂（t-PA）的溶栓治疗至关重要。本研究旨在调查缺血性脑卒中血栓中是否存在中性粒细胞，更具体地说是 NETs。
对 68 例接受血管内治疗的缺血性脑卒中患者的血栓进行免疫染色，使用中性粒细胞标志物（CD66b 和中性粒细胞弹性蛋白酶）和 NET 标志物（瓜氨酸化组蛋白 H3 [H3Cit]和细胞外 DNA）进行特征分析。对中性粒细胞和 NETs 进行定量。此外，通过用 DNA 酶 1 和 t-PA 对回收的血栓进行体外溶解，靶向细胞外 DNA。
在所有血栓中均广泛检测到中性粒细胞。几乎所有的血栓中都观察到 NETs 的标志 H3Cit。H3Cit 阳性区域占血栓总面积的 13.45%。H3Cit 与从中性粒细胞释放的细胞外 DNA 的共定位证实了 NETs 的特异性存在。与其他病因相比，心源性栓塞来源的血栓中 H3Cit 更为丰富。与新鲜血栓相比，陈旧血栓中含有更多的中性粒细胞和 H3Cit。有趣的是，当向标准 t-PA 中添加 DNA 酶 1 时，对患者血栓进行体外溶解更为成功。
中性粒细胞和 NETs 是脑血栓的重要组成部分。用 DNA 酶 1 靶向 NETs 可能具有治疗急性缺血性脑卒中的促溶栓作用。Ann Neurol 2017;82:223-232.
