scholarly journals Platelets and neutrophil extracellular traps collaborate to promote intravascular coagulation during sepsis in mice

Blood ◽  
2017 ◽  
Vol 129 (10) ◽  
pp. 1357-1367 ◽  
Author(s):  
Braedon McDonald ◽  
Rachelle P. Davis ◽  
Seok-Joo Kim ◽  
Mandy Tse ◽  
Charles T. Esmon ◽  
...  

Key Points In vivo imaging reveals a NET–platelet–thrombin axis that promotes intravascular coagulation in sepsis. Inhibition of NETs during sepsis reduces intravascular coagulation, improves microvascular perfusion, and reduces organ damage.

2017 ◽  
Vol 43 (06) ◽  
pp. 553-561 ◽  
Author(s):  
Miguel Jiménez-Alcázar ◽  
Natalie Kim ◽  
Tobias Fuchs

AbstractThrombosis leads to ischemic organ damage in cardiovascular and thromboembolic diseases. Neutrophils promote thrombosis in vitro and in vivo by releasing neutrophil extracellular traps (NETs). NETs are composed of DNA filaments coated with histones and neutrophil enzymes such as myeloperoxidase (MPO). Circulating extracellular DNA (ceDNA) is widely used as a surrogate marker to monitor NET formation in thrombosis. This narrative review summarizes the association of ceDNA with human thrombosis. Levels of ceDNA indicate the extent and outcome of several cardiovascular and thromboembolic diseases, including myocardial infarction, stroke, and venous thromboembolism. ceDNA correlates with markers of coagulation and platelet consumption, thus supporting the hypothesis that ceDNA may be a surrogate marker of thrombus formation. In addition, ceDNA levels correlate with markers of cell injury and size of ischemic lesions, suggesting that ceDNA does not derive from NETs but is probably released from damaged organs. Few studies identified NET-specific biomarkers such as DNA–MPO complexes in the blood of patients with thrombosis. In conclusion, it remains to be established whether ceDNA in patients derives from NETs and is a cause or consequence of thrombosis.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2143 ◽  
Author(s):  
Yasir Alhamdi ◽  
Cheng-Hock Toh

Disseminated intravascular coagulation (DIC) is an acquired condition that develops as a complication of systemic and sustained cell injury in conditions such as sepsis and trauma. It represents major dysregulation and increased thrombin generationin vivo. A poor understanding and recognition of the complex interactions in the coagulation, fibrinolytic, inflammatory, and innate immune pathways have resulted in continued poor management and high mortality rates in DIC. This review focuses attention on significant recent advances in our understanding of DIC pathophysiology. In particular, circulating histones and neutrophil extracellular traps fulfil established criteria in DIC pathogenesis. Both are damaging to the vasculature and highly relevant to the cross talk between coagulation and inflammation processes, which can culminate in adverse clinical outcomes. These molecules have a strong potential to be novel biomarkers and therapeutic targets in DIC, which is still considered synonymous with ‘death is coming’.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250265
Author(s):  
Hubert Hayden ◽  
Nahla Ibrahim ◽  
Johannes Klopf ◽  
Branislav Zagrapan ◽  
Lisa-Marie Mauracher ◽  
...  

Over the past years, neutrophil extracellular traps (NETs) were shown to contribute to states of acute and chronic inflammatory disease. They are composed of expelled chromatin and decorated by neutrophil-derived proteins. Therefore, the analysis of DNA complexes with myeloperoxidase (MPO) by ELISA has become an attractive tool to measure NET formation in in vitro and in vivo samples. When we used a published MPO-DNA ELISA protocol and included an isotype control for the anti-MPO coating antibody, we observed high assay specificity for in vitro prepared NET samples, whereas the specificity for in vivo plasma samples was low. In addition, the assay failed to detect in vitro generated MPO-DNA complexes when spiked into plasma. Therefore, we set out to improve the specificity of the MPO-DNA ELISA for plasma samples. We found that the use of Fab fragments or immunoglobulins from different species or reversal of the antibody pair led to either a high background or a low dynamic range of detection that did not improve the specificity for plasma samples. Also, the use of higher plasma dilutions or pre-clearing of plasma immunoglobulins were ineffective. Finally, we found that a commercial reagent designed to block human anti-mouse antibodies and multivalent substances increased the detection window between the MPO antibody and isotype control for highly diluted plasma. We applied this modified ELISA protocol to analyze MPO-DNA complexes in human blood samples of acute and chronic inflammatory conditions. While markers of neutrophil activation and NET formation such as MPO, elastase and citrullinated histone H3 correlated significantly, we observed no correlation with the levels of MPO-DNA complexes. Therefore, we conclude that ELISA measurements of MPO-DNA complexes in human plasma are highly questionable regarding specificity of NET detection. In general, plasma analyses by ELISA should more frequently include isotype controls for antibodies to demonstrate target specificity.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yilu Zhou ◽  
Weimin Tao ◽  
Fuyi Shen ◽  
Weijia Du ◽  
Zhendong Xu ◽  
...  

Neutrophils play a vital role in the formation of arterial, venous and cancer-related thrombosis. Recent studies have shown that in a process known as NETosis, neutrophils release proteins and enzymes complexed to DNA fibers, collectively called neutrophil extracellular traps (NETs). Although NETs were originally described as a way for the host to capture and kill bacteria, current knowledge indicates that NETs also play an important role in thrombosis. According to recent studies, the destruction of vascular microenvironmental homeostasis and excessive NET formation lead to pathological thrombosis. In vitro experiments have found that NETs provide skeletal support for platelets, red blood cells and procoagulant molecules to promote thrombosis. The protein components contained in NETs activate the endogenous coagulation pathway to promote thrombosis. Therefore, NETs play an important role in the formation of arterial thrombosis, venous thrombosis and cancer-related thrombosis. This review will systematically summarize and explain the study of NETs in thrombosis in animal models and in vivo experiments to provide new targets for thrombosis prevention and treatment.


PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0148142 ◽  
Author(s):  
Paula Giselle Czaikoski ◽  
José Maurício Segundo Correia Mota ◽  
Daniele Carvalho Nascimento ◽  
Fabiane Sônego ◽  
Fernanda Vargas e Silva Castanheira ◽  
...  

2018 ◽  
Vol 114 (8) ◽  
pp. 1178-1188 ◽  
Author(s):  
Daniel S Gaul ◽  
Julien Weber ◽  
Lambertus J van Tits ◽  
Susanna Sluka ◽  
Lisa Pasterk ◽  
...  

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.


2019 ◽  
Vol 46 (12) ◽  
pp. 1560-1569 ◽  
Author(s):  
Mi-Hyun Ahn ◽  
Jae Ho Han ◽  
Young-Jun Chwae ◽  
Ju-Yang Jung ◽  
Chang-Hee Suh ◽  
...  

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.


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