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 Role of neutrophil extracellular traps in radiation resistance of invasive bladder cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Surashri Shinde-Jadhav ◽  
Jose Joao Mansure ◽  
Roni F. Rayes ◽  
Gautier Marcq ◽  
Mina Ayoub ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Neutrophil Extracellular Traps ◽  
Polymorphonuclear Neutrophils ◽  
Dependent Manner ◽  
Potential Therapeutic Target ◽  
Extracellular Traps ◽  
Tumor Immune Microenvironment

AbstractRadiation therapy (RT) is used in the management of several cancers; however, tumor radioresistance remains a challenge. Polymorphonuclear neutrophils (PMNs) are recruited to the tumor immune microenvironment (TIME) post-RT and can facilitate tumor progression by forming neutrophil extracellular traps (NETs). Here, we demonstrate a role for NETs as players in tumor radioresistance. Using a syngeneic bladder cancer model, increased NET deposition is observed in the TIME of mice treated with RT and inhibition of NETs improves overall radiation response. In vitro, the protein HMGB1 promotes NET formation through a TLR4-dependent manner and in vivo, inhibition of both HMGB1 and NETs significantly delays tumor growth. Finally, NETs are observed in bladder tumors of patients who did not respond to RT and had persistent disease post-RT, wherein a high tumoral PMN-to-CD8 ratio is associated with worse overall survival. Together, these findings identify NETs as a potential therapeutic target to increase radiation efficacy.

scholarly journals CXCR4 and CXCR7 Inhibition Ameliorates the Formation of Platelet–Neutrophil Complexes and Neutrophil Extracellular Traps through Adora2b Signaling

2021 ◽  
Vol 22 (24) ◽  
pp. 13576
Author(s):  
Kristian-Christos Ngamsri ◽  
Rizki A. Putri ◽  
Christoph Jans ◽  
Katharina Schindler ◽  
Anika Fuhr ◽  
...  
Keyword(s):  
Chemokine Receptors ◽  
Acute Inflammation ◽  
Neutrophil Extracellular Traps ◽  
Polymorphonuclear Neutrophils ◽  
Protective Effects ◽  
Wild Type ◽  
Extracellular Traps ◽  
The Impact

Peritonitis and peritonitis-associated sepsis are characterized by an increased formation of platelet–neutrophil complexes (PNCs), which contribute to an excessive migration of polymorphonuclear neutrophils (PMN) into the inflamed tissue. An important neutrophilic mechanism to capture and kill invading pathogens is the formation of neutrophil extracellular traps (NETs). Formation of PNCs and NETs are essential to eliminate pathogens, but also lead to aggravated tissue damage. The chemokine receptors CXCR4 and CXCR7 on platelets and PMNs have been shown to play a pivotal role in inflammation. Thereby, CXCR4 and CXCR7 were linked with functional adenosine A2B receptor (Adora2b) signaling. We evaluated the effects of selective CXCR4 and CXCR7 inhibition on PNCs and NETs in zymosan- and fecal-induced sepsis. We determined the formation of PNCs in the blood and, in addition, their infiltration into various organs in wild-type and Adora2b−/− mice by flow cytometry and histological methods. Further, we evaluated NET formation in both mouse lines and the impact of Adora2b signaling on it. We hypothesized that the protective effects of CXCR4 and CXCR7 antagonism on PNC and NET formation are linked with Adora2b signaling. We observed an elevated CXCR4 and CXCR7 expression in circulating platelets and PMNs during acute inflammation. Specific CXCR4 and CXCR7 inhibition reduced PNC formation in the blood, respectively, in the peritoneal, lung, and liver tissue in wild-type mice, while no protective anti-inflammatory effects were observed in Adora2b−/− animals. In vitro, CXCR4 and CXCR7 antagonism dampened PNC and NET formation with human platelets and PMNs, confirming our in vivo data. In conclusion, our study reveals new protective aspects of the pharmacological modulation of CXCR4 and CXCR7 on PNC and NET formation during acute inflammation.

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 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.

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