Elevated Levels of Circulating DNA and Chromatin Are Independently Associated With Severe Coronary Atherosclerosis and a Prothrombotic State

Abstract

OBJECTIVE Aberrant neutrophil activation occurs during the advanced stages of atherosclerosis. Once primed, neutrophils can undergo apoptosis or release neutrophil extracellular traps (NETs). This extracellular DNA exerts potent pro-inflammatory, prothrombotic and cytotoxic properties. The goal of this study was to examine the relationships between extracellular DNA formation, coronary atherosclerosis and the presence of a prothrombotic state. APPROACH AND RESULTS In a prospective, observational, cross-sectional cohort of 282 individuals with suspected coronary artery disease (CAD), we examined the severity, extent, and phenotype of coronary atherosclerosis by using coronary computed tomographic angiography (CCTA). Double-stranded DNA, nucleosomes, citrullinated histone H4 and myeloperoxidase (MPO)-DNA complexes, considered in vivo markers of cell death and NETosis, respectively, were established. We further measured various plasma markers of coagulation activation and inflammation. Plasma double-stranded DNA, nucleosomes and MPO-DNA complexes were positively associated with thrombin generation and significantly elevated in patients with severe coronary atherosclerosis or extremely calcified coronary arteries. Multinomial regression analysis, adjusted for confounding factors, identified high plasma nucleosome levels as an independent risk factor of severe coronary stenosis (OR: 2.14, 95% CI 1.26-3.63; p=0.005). Markers of NETs, such as MPO-DNA complexes, predicted the number of atherosclerotic coronary vessels and the occurrence of major adverse cardiac events. CONCLUSIONS Our report provides evidence demonstrating that markers of cell death and NET formation are independently associated with CAD, prothrombotic state and occurrence of adverse cardiac events. These biomarkers could potentially aid in the prediction of cardiovascular risk in patients with chest discomfort.

Coronary Neutrophil Extracellular Trap Burden and Deoxyribonuclease Activity in ST-Elevation Acute Coronary Syndrome Are Predictors of ST-Segment Resolution and Infarct Size

“…Extracellular nucleosomes and dsDNA have been proposed as surrogate markers for NET burden. 20 We found both nucleosomes and dsDNA to be highly increased in CLS plasma compared with femoral plasma. Moreover, CLS nucleosomes and dsDNA levels correlated positively with thrombus NET burden, which suggests that in STE-ACS, circulating nucleosomes and ds-DNA primarily originate from NETs.…”

“…20 Nucleosomes were significantly increased at the CLS Figure 5A) correlated positively with coronary thrombus NET burden.…”

VWF-mediated leukocyte recruitment with chromatin decondensation by PAD4 increases myocardial ischemia/reperfusion injury in mice

“…13,14 Of interest, plasma MPO-DNA complexes, considered a marker of NETs, were recently associated with the severity of coronary atherosclerosis in humans and occurrence of major adverse cardiac events. 42 Moreover, neutrophil elastase present on NETs 13 catalyzes the breakdown of collagen (type III and IV), fibronectin, and proteoglycans during MI, 10 which could further hinder efficient myocardial repair. Histone citrullination is necessary for chromatin decondensation during NET formation.…”

Neutrophils Cast NETs in Atherosclerosis

“…8,9 The importance of these structures has been described in various diseases, including infection-associated thrombosis, 10 small vessel vasculitis, 11 systemic lupus erythematosus (SLE), [12][13][14] and skin inflammation 15 (Table). A current study has shown that NET fragments may serve as indicators of cardiovascular inflammation, 16 while we could elucidate a mechanism of NET-driven atherogenesis involving the autoimmune activation of plasmacytoid dendritic cells. 9,17 Mechanistically, complexes of self-DNA (presumably NET-borne DNA, but also self-DNA from dying cells) and neutrophil-derived granule proteins (eg, cathelicidin) stimulate plasmacytoid dendritic cells in the vessel wall, resulting in a strong type I interferon response, which drives atherogenesis.…”