Ondracek Anna S, Afonyushkin Taras, Aszlan Adrienne, Taqi Soreen, Koller Thomas, Artner Tyler, Porsch Florentina, Resch Ulrike, Sharma Smriti, Scherz Thomas, Spittler Andreas, Haertinger Maximilian, Hofbauer Thomas M, Ozsvar-Kozma Maria, Seidl Veronika, Beitzke Dietrich, Krueger Marcus, Testori Christoph, Lang Irene M, Binder Christoph J
Department of Internal Medicine II, Cardiology, Medical University of Vienna, Waehringer Guertel 18-20, Leitstelle 6L, 1090 Vienna, Austria.
Department of Laboratory Medicine, Medical University of Vienna, Waehringer Guertel 18-20, Leitstelle 5H, 1090 Vienna, Austria.
Eur Heart J. 2025 Mar 7;46(10):926-939. doi: 10.1093/eurheartj/ehae584.
Neutrophil extracellular traps (NETs) trigger atherothrombosis during acute myocardial infarction (AMI), but mechanisms of induction remain unclear. Levels of extracellular vesicles (EV) carrying oxidation-specific epitopes (OSE), which are targeted by specific natural immunoglobulin M (IgM), are increased at the culprit site in AMI. This study investigated EV as inducers of NETosis and assessed the inhibitory effect of natural anti-OSE-IgM in this process.
Blood from the culprit and peripheral site of ST-segment elevation myocardial infarction (STEMI) patients (n = 28) was collected, and myocardial function assessed by cardiac magnetic resonance imaging (cMRI) 4 ± 2 days and 195 ± 15 days post-AMI. Extracellular vesicles were isolated from patient plasma and cell culture supernatants for neutrophil stimulation in vitro and in vivo, in the presence of a malondialdehyde (MDA)-specific IgM or an isotype control. NETosis and neutrophil functions were assessed via enzyme-linked immunosorbent assay and fluorescence microscopy. Pharmacological inhibitors were used to map signalling pathways. Neutrophil extracellular trap markers and anti-OSE-IgM were measured by ELISA.
CD45+ MDA+ EV and NET markers were elevated at the culprit site. Extracellular vesicles induced neutrophil activation and NET formation via TLR4 and PAD4, and mice injected with EV showed increased NETosis. Malondialdehyde-specific IgM levels were inversely associated with citH3 in STEMI patient blood. An MDA-specific IgM inhibited EV-induced NET release in vitro and in vivo. CD45+ MDA+ EV concentrations inversely correlated with left ventricular ejection fraction post-AMI.
Culprit site-derived EV induce NETosis, while MDA-specific natural IgM inhibit this effect, potentially impacting outcome after AMI.
中性粒细胞胞外诱捕网（NETs）在急性心肌梗死（AMI）期间引发动脉粥样硬化血栓形成，但其诱导机制尚不清楚。携带氧化特异性表位（OSE）的细胞外囊泡（EV）水平在AMI的罪犯部位升高，而OSE是特异性天然免疫球蛋白M（IgM）的靶点。本研究调查了EV作为NETosis诱导剂的作用，并评估了天然抗OSE-IgM在此过程中的抑制作用。
收集ST段抬高型心肌梗死（STEMI）患者（n = 28）罪犯部位和外周部位的血液，并在AMI后4±2天和195±15天通过心脏磁共振成像（cMRI）评估心肌功能。从患者血浆和细胞培养上清液中分离细胞外囊泡，用于在体外和体内刺激中性粒细胞，同时存在丙二醛（MDA）特异性IgM或同型对照。通过酶联免疫吸附测定和荧光显微镜评估NETosis和中性粒细胞功能。使用药理学抑制剂来确定信号通路。通过ELISA测量中性粒细胞胞外诱捕网标志物和抗OSE-IgM。
罪犯部位的CD45+ MDA+ EV和NET标志物升高。细胞外囊泡通过TLR4和PAD4诱导中性粒细胞活化和NET形成，注射EV的小鼠显示NETosis增加。STEMI患者血液中丙二醛特异性IgM水平与瓜氨酸化组蛋白H3呈负相关。MDA特异性IgM在体外和体内均抑制EV诱导的NET释放。CD45+ MDA+ EV浓度与AMI后左心室射血分数呈负相关。
罪犯部位来源的EV诱导NETosis，而MDA特异性天然IgM抑制这种作用，这可能影响AMI后的结局。
