scholarly journals DNase 1 Protects From Increased Thrombin Generation and Venous Thrombosis During Aging: Cross‐Sectional Study in Mice and Humans

2022 ◽  
Author(s):  
Rahul Kumar ◽  
Vijay K. Sonkar ◽  
Jagadish Swamy ◽  
Azaj Ahmed ◽  
Anjali A. Sharathkumar ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Transgenic Mice ◽  
Thrombin Generation ◽  
Neutrophil Extracellular Traps ◽  
Wild Type ◽  
Cell Free Dna ◽  
Glutathione Peroxidase 1 ◽  
Extracellular Traps ◽  
Free Dna ◽  
Dnase 1

Background Human aging is associated with increased risk of thrombosis, but the mechanisms are poorly defined. We hypothesized that aging induces peroxide‐dependent release of neutrophil extracellular traps that contribute to thrombin generation and thrombosis. Methods and Results We studied C57BL6J mice and littermates of glutathione peroxidase‐1 transgenic and wild‐type mice at young (4 month) and old (20 month) ages and a healthy cohort of young (18–39 years) or middle‐aged/older (50–72 years) humans. In plasma, we measured thrombin generation potential and components of neutrophil extracellular traps (cell‐free DNA and citrullinated histone). Aged wild‐type mice displayed a significant increase in thrombin generation that was decreased in aged glutathione peroxidase‐1 transgenic mice. Both aged wild‐type and aged glutathione peroxidase‐1 transgenic mice demonstrated similar elevation of plasma cell‐free DNA compared with young mice. In contrast, plasma levels of citrullinated histone were not altered with age or genotype. Release of neutrophil extracellular traps from neutrophils in vitro was also similar between young and aged wild‐type or glutathione peroxidase‐1 transgenic mice. Treatment of plasma or mice with DNase 1 decreased age‐associated increases in thrombin generation, and DNase 1 treatment blocked the development of experimental venous thrombi in aged C57BL6J mice. Similarly, thrombin generation potential and plasma cell‐free DNA, but not citrullinated histone, were higher in middle‐aged/older humans, and treatment of plasma with DNase 1 reversed the increase in thrombin generation. Conclusions We conclude that DNase 1 limits thrombin generation and protects from venous thrombosis during aging, likely by hydrolyzing cell‐free DNA.

Neutrophil Extracellular Traps May Contribute to the Pathogenesis in Adult-onset Still Disease

2019 ◽  
Vol 46 (12) ◽  
pp. 1560-1569 ◽  
Author(s):  
Mi-Hyun Ahn ◽  
Jae Ho Han ◽  
Young-Jun Chwae ◽  
Ju-Yang Jung ◽  
Chang-Hee Suh ◽  
...  
Keyword(s):  
Immunohistochemical Analysis ◽  
Serum Levels ◽  
Neutrophil Extracellular Traps ◽  
Polymorphonuclear Neutrophils ◽  
Adult Onset ◽  
Cell Free Dna ◽  
Extracellular Traps ◽  
Free Dna ◽  
Still Disease

Objective.Release of neutrophil extracellular traps (NET) has been described as an effector mechanism of polymorphonuclear neutrophils in several inflammatory diseases. Thus, this study was performed to evaluate the role of NET in the pathogenesis of adult-onset Still disease (AOSD).Methods.We determined the serum levels of NET molecules and investigated their associations with clinical disease activities in patients with AOSD. Further, we analyzed the differences in the NETosis response in AOSD patients compared to healthy controls (HC). To explore the in vivo involvement of NET in AOSD, we performed immunohistochemical analysis of skin and lymph node (LN) biopsies for proteins related to NET in patients with active AOSD.Results.Serum levels of cell-free DNA, myeloperoxidase (MPO)-DNA complex, and α-defensin were significantly increased in patients with AOSD compared to HC. Serum levels of the NET molecules, cell-free DNA, MPO-DNA, and α-defensin were correlated with several disease activity markers for AOSD. In followup of patients with AOSD after treatment with corticosteroid, the levels of cell-free DNA and α-defensin decreased significantly. On immunohistochemistry, neutrophil elastase–positive and MPO-positive inflammatory cells were detected in skin and LN of patients with AOSD, and were expressed in fiber form in the lesions. The serum from patients with active AOSD induced NETosis in neutrophils from HC. NET molecules induced interleukin 1β production in monocytes, representing a novel mechanism in the pathogenesis of AOSD.Conclusion.The findings presented here suggest that NET may contribute to the inflammatory response and pathogenesis in AOSD.

scholarly journals Circulating Neutrophil Extracellular Traps in the Pathogenesis of Acute Chest Syndrome of Sickle Cell Disease

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3556-3556
Author(s):  
Ravi Vats ◽  
Egemen Tutuncuoglu ◽  
Jesus Tejero ◽  
Cheryl A Hillery ◽  
Mark T Gladwin ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Lung Injury ◽  
Sickle Cell ◽  
Neutrophil Extracellular Traps ◽  
Acute Chest Syndrome ◽  
Cell Disease ◽  
Cell Free Dna ◽  
Extracellular Traps ◽  
Free Dna ◽  
Platelet Aggregates

Introduction: Acute chest syndrome (ACS) is a type of acute lung injury and among the primary reasons for mortality and morbidity among Sickle Cell Disease (SCD) patients. Although epidemiologic evidence suggests that vaso-occlusion in the lung may serve as an antecedent to ACS, the cellular, molecular and biophysical mechanism of ACS is incompletely understood. Our recent findings revealed that the lung vaso-occlusion is enabled by the entrapment of embolic neutrophil-platelet aggregates in the pulmonary arterioles of transgenic humanized SCD mice. Recent evidence also suggests a role for neutrophil extracellular traps (NETs) in ACS. NETs are web-like structures of decondensed nuclear DNA decorated with citrullinated-histones (H3-cit) and neutrophil granule proteins. Interestingly, circulating nucleosomes and NETs fragments are elevated in SCD patient blood and the levels correlate with onset of ACS, however, the molecular mechanism that promotes generation of circulating NETs and the role of circulating NETs in promoting ACS remains poorly understood. Materials and Methods: Townes knock-in humanized SS (hα/hα:βS/βS) and AS (hα/hα:βA/βS) mice were used as SCD and control mice, respectively. SS and AS mice were intravenously (IV) administered 10 µmole/kg Oxy-Hb followed by Sytox orange, FITC-dextran or fluorescent anti-mouse mAbs against Ly6G, CD49b, H3cit, and neutrophil elastase for in vivo visualization of extracellular DNA, blood vessels, neutrophils, platelets and NETs, respectively. Pulmonary microcirculation was monitored using multi-photon-excitation enabled quantitative fluorescence intravital lung microscopy (qFILM). Results and Discussion: IV Oxy-Hb triggered the occlusion of pulmonary arterioles by neutrophil-platelet aggregates leading to loss of pulmonary blood flow in SCD but not control mice. Surprisingly, pulmonary vaso-occlusion in SCD mice was accompanied by the arrival of circulating cell free DNA (CFD) and NETs fragments into the pulmonary circulation. The cell free DNA (CFD) and NETs fragments entered the lung through the arterial circulation suggesting that they originated outside of lung. These cell free DNA (CFD) and NETs fragments contributed to lung vaso-occlusion and injury by promoting neutrophil-platelet aggregation in the lung arterioles. Conclusion: These findings reveal for the first time that circulating cell free DNA (CFD) and NETs fragments originating outside of lung contribute to pathogenesis of ACS. Currently, experiments are underway to identify the innate immune pathways that promote circulating NETs dependent lung injury in SCD. Disclosures Gladwin: Globin Solutions, Inc: Patents & Royalties: Provisional patents for the use of recombinant neuroglobin and heme-based molecules as antidotes for CO poisoning; United Therapeutics: Patents & Royalties: Co-inventor on an NIH government patent for the use of nitrite salts in cardiovascular diseases ; Bayer Pharmaceuticals: Other: Co-investigator.

Elevated Levels of Total Cell-Free DNA in Maternal Serum Samples Arise from the Generation of Neutrophil Extracellular Traps

2016 ◽  
Vol 40 (4) ◽  
pp. 263-267 ◽  
Author(s):  
Chanchal Sur Chowdhury ◽  
Sinuhe Hahn ◽  
Paul Hasler ◽  
Irene Hoesli ◽  
Olav Lapaire ◽  
...  
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Maternal Serum ◽  
Total Cell ◽  
Serum Samples ◽  
Cell Free Dna ◽  
Extracellular Traps ◽  
Free Dna

scholarly journals Role of Cell-Free DNA and Deoxyribonucleases in Tumor Progression

2021 ◽  
Vol 22 (22) ◽  
pp. 12246
Author(s):  
Ludmila Alekseeva ◽  
Nadezhda Mironova
Keyword(s):  
Tumor Progression ◽  
Immune Cells ◽  
Neutrophil Extracellular Traps ◽  
Genomic Profile ◽  
Cell Free Dna ◽  
Patients With Cancer ◽  
Extracellular Traps ◽  
Free Dna ◽  
Main Component

Many studies have reported an increase in the level of circulating cell-free DNA (cfDNA) in the blood of patients with cancer. СfDNA mainly comes from tumor cells and, therefore, carries features of its genomic profile. Moreover, tumor-derived cfDNA can act like oncoviruses, entering the cells of vulnerable organs, transforming them and forming metastatic nodes. Another source of cfDNA is immune cells, including neutrophils that generate neutrophil extracellular traps (NETs). Despite the potential eliminative effect of NETs on tumors, in some cases, their excessive generation provokes tumor growth as well as invasion. Considering both possible pathological contributions of cfDNA, as an agent of oncotransformation and the main component of NETs, the study of deoxyribonucleases (DNases) as anticancer and antimetastatic agents is important and promising. This review considers the pathological role of cfDNA in cancer development and the role of DNases as agents to prevent and/or prohibit tumor progression and the development of metastases.

scholarly journals The Inhibitory Effect of Curosurf® and Alveofact® on the Formation of Neutrophil Extracellular Traps

2021 ◽  
Vol 11 ◽  
Author(s):  
Annabell Schulz ◽  
Laia Pagerols Raluy ◽  
Jan Philipp Kolman ◽  
Ingo Königs ◽  
Magdalena Trochimiuk ◽  
...  
Keyword(s):  
Immunofluorescence Microscopy ◽  
Inflammatory Diseases ◽  
Neutrophil Extracellular Traps ◽  
Inhibitory Effect ◽  
Neutrophil Granulocytes ◽  
Cell Free Dna ◽  
Extracellular Traps ◽  
Free Dna ◽  
Specific Proteins ◽  
Dose Dependent

BackgroundNeutrophil extracellular traps (NETs) are a defense mechanism in which neutrophils cast a net-like structure in response to microbial infection. NETs consist of decondensed chromatin and about 30 enzymes and peptides. Some components, such as neutrophil elastase (NE) and myeloperoxidase (MPO), present antimicrobial but also cytotoxic properties, leading to tissue injury. Many inflammatory diseases are associated with NETs, and their final role has not been identified. Pulmonary surfactant is known to have immunoregulatory abilities that alter the function of adaptive and innate immune cells. The aim of this study was to investigate the hypothesis that natural surfactant preparations inhibit the formation of NETs.MethodsThe effect of two natural surfactants (Alveofact® and Curosurf®) on spontaneous and phorbol-12-myristate-13-acetate–induced NET formation by neutrophils isolated by magnetic cell sorting from healthy individuals was examined. NETs were quantitatively detected by absorption and fluorometric-based assays for the NET-specific proteins (NE, MPO) and cell-free DNA. Immunofluorescence microscopy images were used for visualization.ResultsBoth surfactant preparations exerted a dose-dependent inhibitory effect on NET formation. Samples treated with higher concentrations and with 30 min pre-incubation prior to stimulation with phorbol-12-myristate-13-acetate had significantly lower levels of NET-specific proteins and cell-free DNA compared to untreated samples. Immunofluorescence microscopy confirmed these findings.ConclusionsThe described dose-dependent modulation of NET formation ex vivo suggests an interaction between exogenous surfactant supplementation and neutrophil granulocytes. The immunoregulatory effects of surfactant preparations should be considered for further examination of inflammatory diseases.

scholarly journals Neutrophil extracellular traps (NETs) as markers of disease severity in COVID-19

2020 ◽  
Author(s):  
Yu Zuo ◽  
Srilakshmi Yalavarthi ◽  
Hui Shi ◽  
Kelsey Gockman ◽  
Melanie Zuo ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Absolute Neutrophil Count ◽  
Neutrophil Count ◽  
Neutrophil Extracellular Traps ◽  
Hospitalized Patients ◽  
Acute Phase Reactants ◽  
Cell Free Dna ◽  
Extracellular Traps ◽  
Free Dna

ABSTRACTIn severe cases of coronavirus disease 2019 (COVID-19), viral pneumonia progresses to respiratory failure. Neutrophil extracellular traps (NETs) are extracellular webs of chromatin, microbicidal proteins, and oxidant enzymes that are released by neutrophils to contain infections. However, when not properly regulated, NETs have potential to propagate inflammation and microvascular thrombosis—including in the lungs of patients with acute respiratory distress syndrome. While elevated levels of blood neutrophils predict worse outcomes in COVID-19, the role of NETs has not been investigated. We now report that sera from patients with COVID-19 (n=50 patients, n=84 samples) have elevated levels of cell-free DNA, myeloperoxidase(MPO)-DNA, and citrullinated histone H3 (Cit-H3); the latter two are highly specific markers of NETs. Highlighting the potential clinical relevance of these findings, cell-free DNA strongly correlated with acute phase reactants including C-reactive protein, D-dimer, and lactate dehydrogenase, as well as absolute neutrophil count. MPO-DNA associated with both cell-free DNA and absolute neutrophil count, while Cit-H3 correlated with platelet levels. Importantly, both cell-free DNA and MPO-DNA were higher in hospitalized patients receiving mechanical ventilation as compared with hospitalized patients breathing room air. Finally, sera from individuals with COVID-19 triggered NET release from control neutrophils in vitro. In summary, these data reveal high levels of NETs in many patients with COVID-19, where they may contribute to cytokine release and respiratory failure. Future studies should investigate the predictive power of circulating NETs in longitudinal cohorts, and determine the extent to which NETs may be novel therapeutic targets in severe COVID-19.

scholarly journals Loss of Sirt3 accelerates arterial thrombosis by increasing formation of neutrophil extracellular traps and plasma tissue factor activity

2018 ◽  
Vol 114 (8) ◽  
pp. 1178-1188 ◽  
Author(s):  
Daniel S Gaul ◽  
Julien Weber ◽  
Lambertus J van Tits ◽  
Susanna Sluka ◽  
Lisa Pasterk ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Bone Marrow ◽  
Arterial Thrombosis ◽  
Ex Vivo ◽  
Neutrophil Extracellular Traps ◽  
Wild Type ◽  
Rotational Thromboelastometry ◽  
Extracellular Traps

AbstractAimsSirtuin 3 (Sirt3) is a mitochondrial, nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that reduces oxidative stress by activation of superoxide dismutase 2 (SOD2). Oxidative stress enhances arterial thrombosis. This study investigated the effects of genetic Sirt3 deletion on arterial thrombosis in mice in an inflammatory setting and assessed the clinical relevance of these findings in patients with ST-elevation myocardial infarction (STEMI).Methods and resultsUsing a laser-induced carotid thrombosis model with lipopolysaccharide (LPS) challenge, in vivo time to thrombotic occlusion in Sirt3−/− mice (n = 6) was reduced by half compared to Sirt3+/+ wild-type (n = 8, P < 0.01) controls. Ex vivo analyses of whole blood using rotational thromboelastometry revealed accelerated clot formation and increased clot stability in Sirt3−/− compared to wild-type blood. rotational thromboelastometry of cell-depleted plasma showed accelerated clotting initiation in Sirt3−/− mice, whereas overall clot formation and firmness remained unaffected. Ex vivo LPS-induced neutrophil extracellular trap formation was increased in Sirt3−/− bone marrow-derived neutrophils. Plasma tissue factor (TF) levels and activity were elevated in Sirt3−/− mice, whereas plasma levels of other coagulation factors and TF expression in arterial walls remained unchanged. SOD2 expression in bone marrow -derived Sirt3−/− neutrophils was reduced. In STEMI patients, transcriptional levels of Sirt3 and its target SOD2 were lower in CD14+ leukocytes compared with healthy donors (n = 10 each, P < 0.01).ConclusionsSirt3 loss-of-function enhances experimental thrombosis in vivo via an increase of neutrophil extracellular traps and elevation of TF suggesting thrombo-protective effects of endogenous Sirt3. Acute coronary thrombosis in STEMI patients is associated with lower expression levels of SIRT3 and SOD2 in CD14+ leukocytes. Therefore, enhancing SIRT3 activity by pan-sirtuin activating NAD+-boosters may provide a novel therapeutic target to prevent or treat thrombotic arterial occlusion in myocardial infarction or stroke.

Glutathione peroxidase-1 overexpressing transgenic mice are protected from cocaine-induced drug dependence

2019 ◽  
Vol 124 ◽  
pp. 264-273 ◽  
Author(s):  
Huynh Nhu Mai ◽  
Yoon Hee Chung ◽  
Eun-Joo Shin ◽  
Dae-Joong Kim ◽  
Naveen Sharma ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Transgenic Mice ◽  
Drug Dependence ◽  
Glutathione Peroxidase 1
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