scholarly journals Pathophysiologic and Therapeutic Perspectives Based on Thrombus Histology in Stroke

2020 ◽  
Vol 22 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Ji Hoe Heo ◽  
Hyo Suk Nam ◽  
Young Dae Kim ◽  
Jin Kyo Choi ◽  
Byung Moon Kim ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Stroke Prevention ◽  
Thrombus Formation ◽  
Neutrophil Extracellular Traps ◽  
Reperfusion Therapy ◽  
Prevention Research ◽  
Endovascular Thrombectomy ◽  
Stroke Etiology ◽  
Extracellular Traps ◽  
Histopathologic Analysis

Recent advances in endovascular thrombectomy have enabled the histopathologic analysis of fresh thrombi in patients with acute stroke. Histologic analysis has shown that the thrombus composition is very heterogeneous between patients. However, the distribution pattern of each thrombus component often differs between patients with cardiac thrombi and those with arterial thrombi, and the efficacy of endovascular thrombectomy is different according to the thrombus composition. Furthermore, the thrombus age is related to the efficacy of reperfusion therapy. Recent studies have shown that neutrophils and neutrophil extracellular traps contribute to thrombus formation and resistance to reperfusion therapy. Histologic features of thrombi in patients with stroke may provide some clues to stroke etiology, which is helpful for determining the strategy of stroke prevention. Research on thrombus may also be helpful for improving reperfusion therapy, including the development of new thrombolytic agents.

Neutrophil Extracellular Traps Induce Platelet Adhesion and Thrombus Formation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1345-1345 ◽  
Author(s):  
Tobias Fuchs ◽  
Alexander Brill ◽  
Daniel Dürschmied ◽  
Daphne Schatzberg ◽  
John H. Hartwig ◽  
...  
Keyword(s):  
Whole Blood ◽  
Platelet Adhesion ◽  
Conflicts Of Interest ◽  
Thrombus Formation ◽  
Neutrophil Extracellular Traps ◽  
Thrombin Inhibitor ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Extracellular Traps ◽  
Deep Vein

Abstract Abstract 1345 Introduction Thrombus stability is provided by very large polymers adhering to platelets and anchoring the thrombus to the vessel wall. The best described polymers are fibrin and von Willebrand Factor (VWF). Activated neutrophils and other leukocytes can form an extracellular fibrous network which is composed of DNA, histones, and granular proteins. These neutrophil extracellular traps (NETs) are present in various inflammatory diseases. In deep vein thrombosis (DVT) inflammation closely cooperates with thrombosis. Here we examine whether NETs provide a new means to support the adhesion and recruitment of platelets and whether NETs are present in DVT. Methods and Results: To study the interaction of platelets with NETs, we isolated human neutrophils, induced NET formation and perfused over the NETs human platelets in plasma or whole blood anticoagulated with the thrombin inhibitor PPACK. Microscopic analysis revealed that under flow platelets adhere avidly to NETs. Perfusion of whole blood at physiological shear resulted in formation of thrombi on NETs in a time dependent manner. Addition of DNase1 degraded NETs and removed all platelets and thrombi demonstrating their adhesion to NETs. Thrombus formation on NETs was absent if blood was supplemented with EDTA indicating the requirement for divalent cations. Perfusion of NETs with heparinized blood dismantled NETs and prevented thrombus formation. Incubation of NETs with heparin alone released histones from NETs, indicating that heparin destroys the chromatin backbone of NETs. Furthermore, immunocytochemistry revealed that NETs were able to bind platelet adhesion molecules VWF and fibronectin from human plasma. Immunohistochemical analysis of a baboon deep vein thrombus showed abundant extracellular chromatin which co-localized with fibronectin and VWF. Conclusions: We show that extracellular traps are able to promote thrombosis in vitro and are abundant in vivo in DVT. We propose that extracellular chromatin provides a new type of scaffold that promotes platelet adhesion, activation, and aggregation and may be important for thrombus initiation or stability. Disclosures No relevant conflicts of interest to declare.

scholarly journals DNA, histones and neutrophil extracellular traps exert anti-fibrinolytic effects in a plasma environment

2015 ◽  
Vol 113 (06) ◽  
pp. 1289-1298 ◽  
Author(s):  
Imre Varjú ◽  
Colin Longstaff ◽  
László Szabó ◽  
Ádám Zoltán Farkas ◽  
Veronika Judit Varga-Szabó ◽  
...  
Keyword(s):  
Thrombus Formation ◽  
Fibre Diameter ◽  
Neutrophil Extracellular Traps ◽  
Enzymatic Digestion ◽  
Enzyme Inactivation ◽  
Tissue Type ◽  
Confocal Laser ◽  
Sem Images ◽  
Permeability Constant ◽  
Extracellular Traps

SummaryIn response to various inflammatory stimuli, neutrophils secrete neutrophil extracellular traps (NETs), web-like meshworks of DNA, histones and granular components forming supplementary scaffolds in venous and arterial thrombi. Isolated DNA and histones are known to promote thrombus formation and render fibrin clots more resistant to mechanical forces and tissue-type plasminogen activator (tPA)-induced enzymatic digestion. The present study extends our earlier observations to a physiologically more relevant environment including plasma clots and NET-forming neutrophils. A range of techniques was employed including imaging (scanning electron microscopy (SEM), confocal laser microscopy, and photoscanning of macroscopic lysis fronts), clot permeability measurements, turbidimetric lysis and enzyme inactivation assays. Addition of DNA and histones increased the median fibre diameter of plasma clots formed with 16 nM thrombin from 108 to 121 and 119 nm, respectively, and decreased their permeability constant from 6.4 to 3.1 and 3.7×10−9 cm2. Histones effectively protected thrombin from antithrombin-induced inactivation, while DNA inhibited plasminogen activation on the surface of plasma clots and their plasmin-induced resolution by 20 and 40 %, respectively. DNA and histones, as well as NETs secreted by phorbol-myristate-acetate-activated neutrophils, slowed down the tPA-driven lysis of plasma clots and the latter effect could be reversed by the addition of DNase (streptodornase). SEM images taken after complete digestion of fibrin in NET-containing plasma clots evidenced retained NET scaffold that was absent in DNase-treated clots. Our results show that DNA and histones alter the fibrin architecture in plasma clots, while NETs contribute to a decreased lytic susceptibility that can be overcome by DNase.

scholarly journals Coronavirus disease 2019 (COVID-19): NETosis-associated mechanisms of progression and prospects for therapy regulating the formation of neutrophil extracellular traps (NETs)

2021 ◽  
Vol 6 (4) ◽  
pp. 64-73
Author(s):  
K. A. Aitbaev ◽  
I. T. Murkamilov ◽  
V. V. Fomin ◽  
I. O. Kudaibergenova ◽  
F. A. Yusupov
Keyword(s):  
Molecular Mechanisms ◽  
Adverse Reactions ◽  
Thrombus Formation ◽  
The Elderly ◽  
Neutrophil Extracellular Traps ◽  
The Body ◽  
Surrounding Tissue ◽  
Chronic Respiratory Diseases ◽  
Small Vessels ◽  
Extracellular Traps

Infectious disease COVID-19 caused by the SARS-CoV-2 coronavirus is characterized by high contagiousness, complexity of pathogenesis and unpredictability of the clinical course. In severe cases, which are especially susceptible to men, the elderly and people with underlying medical conditions such as obesity, diabetes, hypertension, cardiovascular and chronic respiratory diseases, the infection leads to respiratory failure and death due to the development of an extensive inflammatory reaction. As a result of many studies, it has been established that one of the leading causes of the severe course and death of patients with COVID-19 is the development of coagulopathy, that is, increased thrombus formation in small vessels due to excessive activity of neutrophils, which form the so-called neutrophil extracellular traps (NETs). Although NETs play a useful role in protecting their host from pathogens, their overgrowth can trigger a cascade of adverse reactions including: the production of antibodies against the host’s DNA (autoimmunization); damage to surrounding tissue; or the occurrence of thromboembolic complications. Therefore, extracellular neutrophil traps and their markers have been identified as targets for new therapeutic strategies aimed at reducing the severity of COVID-19 disease and/or mortality. This article describes the structure of NETs, as well as analyzes the molecular mechanisms that contribute to their overgeneration. In addition, the prospects for COVID-19 therapy aimed at regulating the formation of extracellular traps by creating drugs both limiting the production of NET structures and dissolving their excess amounts in the body of patients are discussed.

scholarly journals Neutrophil Extracellular Traps in Arterial and Venous Thrombosis

2019 ◽  
Vol 45 (01) ◽  
pp. 086-093 ◽  
Author(s):  
Elodie Laridan ◽  
Kimberly Martinod ◽  
Simon De Meyer
Keyword(s):  
Myocardial Infarction ◽  
Thrombus Formation ◽  
Neutrophil Extracellular Traps ◽  
Major Health ◽  
Vein Thrombosis ◽  
Extracellular Traps ◽  
Thrombotic Complications ◽  
Decondensed Chromatin ◽  
Deep Vein ◽  
Novel Therapeutic

AbstractThrombotic complications are still a major health risk worldwide. Our view on the pathophysiology of thrombosis has significantly changed since the discovery of neutrophil extracellular traps (NETs) and their prothrombotic characteristics. Generated by neutrophils that release their decondensed chromatin as a network of extracellular fibers, NETs promote thrombus formation by serving as a scaffold that activates platelets and coagulation. The thrombogenic involvement of NETs has been described in various settings of thrombosis, including stroke, myocardial infarction, and deep vein thrombosis. The aim of this review is to summarize existing evidence showing the presence of NETs in human thrombus material. Following an introduction on NETs and their role in thrombus formation, the authors address studies showing the presence of NETs in arterial or venous thrombi. In addition, they focus on potential novel therapeutic opportunities to resolve or prevent thrombosis by targeting NETs.

Circulating Extracellular DNA: Cause or Consequence of Thrombosis?

2017 ◽  
Vol 43 (06) ◽  
pp. 553-561 ◽  
Author(s):  
Miguel Jiménez-Alcázar ◽  
Natalie Kim ◽  
Tobias Fuchs
Keyword(s):  
Myocardial Infarction ◽  
Cell Injury ◽  
Thrombus Formation ◽  
Surrogate Marker ◽  
Neutrophil Extracellular Traps ◽  
Organ Damage ◽  
Extracellular Dna ◽  
Extracellular Traps

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.

scholarly journals Neutrophil extracellular traps in patients with liver cirrhosis and hepatocellular carcinoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robin Zenlander ◽  
Sebastian Havervall ◽  
Maria Magnusson ◽  
Jennie Engstrand ◽  
Anna Ågren ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Cirrhosis ◽  
Plasma Levels ◽  
Thrombus Formation ◽  
Laboratory Data ◽  
Neutrophil Extracellular Traps ◽  
Clinical Parameters ◽  
Healthy Controls ◽  
Coagulation Activity ◽  
Extracellular Traps

AbstractNeutrophil extracellular traps (NETs) are web-like structures consisting of DNA, histones and granule proteins, released from neutrophils in thrombus formation, inflammation, and cancer. We asked if plasma levels of the NET markers myeloperoxidase (MPO)-DNA and citrullinated histone H3 (H3Cit)-DNA, are elevated in liver cirrhosis and hepatocellular carcinoma (HCC) and if the levels correlate with clinical parameters. MPO-DNA, H3Cit-DNA, and thrombin–antithrombin (TAT) complex, as a marker of coagulation activity, were measured using ELISA in plasma from 82 patients with HCC, 95 patients with cirrhosis and 50 healthy controls. Correlations were made to clinical parameters and laboratory data and patients were followed for a median of 22.5 months regarding thrombosis development. H3Cit-DNA was significantly (p < 0.01) elevated in plasma from cirrhosis (66.4 ng/mL) and HCC (63.8 ng/mL) patients compared to healthy controls (31.8 ng/mL). TAT levels showed similar pattern (3.1, 3.7, and 0.0 µg/mL respectively, p < 0.01). MPO-DNA was significantly (p < 0.01) elevated in cirrhosis patients (0.53 O.D.) as compared to controls (0.33 O.D.). Levels of MPO-DNA and H3Cit-DNA correlated positively with Child–Pugh and MELD score. TAT was increased in all Child–Pugh and MELD groups. In multivariable logistic regression, Child B and C liver cirrhosis were independent predictors of elevated H3Cit-DNA in plasma. Levels of MPO-DNA and H3Cit-DNA were similar in patients with or without history of thrombosis, or thrombus formation during follow-up. In conclusion, plasma markers of NET formation are elevated in liver cirrhosis and correlate to the degree of liver dysfunction in patients with liver cirrhosis and/or HCC. The presence of HCC did not further increase the plasma levels of NET markers as compared to patients with cirrhosis only.

scholarly journals Neutrophil Extracellular Traps as an Adhesion Substrate for Different Tumor Cells Expressing RGD-Binding Integrins

2018 ◽  
Vol 19 (8) ◽  
pp. 2350 ◽  
Author(s):  
Marcello Monti ◽  
Viviana De Rosa ◽  
Francesca Iommelli ◽  
Maria Vincenza Carriero ◽  
Cristina Terlizzi ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cancer Cells ◽  
Cell Lines ◽  
Defense Mechanism ◽  
Cell Attachment ◽  
Thrombus Formation ◽  
Neutrophil Extracellular Traps ◽  
Adhesion Properties ◽  
Extracellular Traps ◽  
Relevant Role

Neutrophil extracellular traps (NETs), in addition to their function as a host defense mechanism, play a relevant role in thrombus formation and metastatic dissemination of cancer cells. Here we screened different cancer cell lines endogenously expressing a variety of integrins for their ability to bind to NETs. To this end, we used NETs isolated from neutrophil-like cells as a substrate for adhesion assays of HT1080, U-87 MG, H1975, DU 145, PC-3 and A-431 cells. Levels of α5, αIIb, αv, β1, β3 and β5 chains were determined by western blot analysis in all cell lines and levels of whole integrins on the plasma membrane were assessed by fluorescence-activated cell sorting (FACS) analysis. We found that high levels of α5β1, αvβ3 and αvβ5 enhance cell adhesion to NETs, whereas low expression of α5β1 prevents cell attachment to NETs. Excess of cyclic RGD peptide inhibited cell adhesion to NETs by competing with fibronectin within NETs. The maximal reduction of such adhesion was similar to that obtained by DNase 1 treatment causing DNA degradation. Our findings indicate that NETs from neutrophil-like cells may be used as a substrate for large screening of the adhesion properties of cancer cells expressing a variety of RGD-binding integrins.

scholarly journals TAB-TICI Score: Successful Recanalization Score After Endovascular Thrombectomy in Acute Stroke

2021 ◽  
Vol 12 ◽  
Author(s):  
Woo-Keun Seo ◽  
Hyo Suk Nam ◽  
Jong-Won Chung ◽  
Young Dae Kim ◽  
Keon-Ha Kim ◽  
...  
Keyword(s):  
Acute Stroke ◽  
External Validation ◽  
Reperfusion Therapy ◽  
Sensitivity Analyses ◽  
Stroke Patients ◽  
Training Population ◽  
Vessel Occlusion ◽  
Endovascular Thrombectomy ◽  
Stroke Registry ◽  
Validation Population

Background and Purpose: Successful reperfusion therapy is supposed to be comprehensive and validated beyond the grade of recanalization. This study aimed to develop a novel scoring system for defining the successful recanalization after endovascular thrombectomy.Methods: We analyzed the data of consecutive acute stroke patients who were eligible to undergo reperfusion therapy within 24 h of onset and who underwent mechanical thrombectomy using a nationwide multicenter stroke registry. A new score was produced using the predictors which were directly linked to the procedure to evaluate the performance of the thrombectomy procedure.Results: In total, 446 patients in the training population and 222 patients in the validation population were analyzed. From the potential components of the score, four items were selected: Emergency Room-to-puncture time (T), adjuvant devices used (A), procedural intracranial bleeding (B), and post-thrombectomy reperfusion status [Thrombolysis in Cerebral Infarction (TICI)]. Using these items, the TAB-TICI score was developed, which showed good performance in terms of discriminating early neurological aggravation [AUC 0.73, 95% confidence interval (CI) 0.67–0.78, P &lt; 0.01] and favorable outcomes (AUC 0.69, 95% CI 0.64–0.75, P &lt; 0.01) in the training population. The stability of the TAB-TICI score was confirmed by external validation and sensitivity analyses. The TAB-TICI score and its derived grade of successful recanalization were significantly associated with the volume of thrombectomy cases at each site and in each admission year.Conclusion: The TAB-TICI score is a valid and easy-to-use tool to more comprehensively define successful recanalization after endovascular thrombectomy in acute stroke patients with large vessel occlusion.

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