scholarly journals The Emerging Role of Neutrophil Extracellular Traps in Arterial, Venous and Cancer-Associated Thrombosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Yilu Zhou ◽  
Weimin Tao ◽  
Fuyi Shen ◽  
Weijia Du ◽  
Zhendong Xu ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Neutrophil Extracellular Traps ◽  
Vital Role ◽  
Extracellular Traps ◽  
Protein Components ◽  
Cancer Associated Thrombosis ◽  
Coagulation Pathway

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.

scholarly journals Gastric Cancer-Induced Neutrophil Extracellular Traps: A Potent Mediator of Cancer Associated Thrombosis

2021 ◽  
Author(s):  
Jiacheng Li ◽  
Xiaoming Zou ◽  
Shifeng Yang ◽  
Jiaqi Jin ◽  
Lei Zhu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Flow Cytometry ◽  
Activated Protein C ◽  
Neutrophil Extracellular Traps ◽  
Mice Model ◽  
Tissue Samples ◽  
Extracellular Traps ◽  
Cancer Associated Thrombosis

Abstract Background: Development of venous thromboembolism (VTE) is associated with high mortalities among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlated to procoagulant and prothrombotic in some diseases. We aimed to clarify that NETs participates in the development of cancer-associated thrombosis in GC.Method: The level of NETs in blood and tissue samples of patients were analyzed by ELISA and flow cytometry. NETs generation in vitro were observed by immunofluorescence (IF). The NETs procoagulant activity (PCA) was performed by fibrin formation and thrombin-antithrombin complex (TAT) assays. Hypercoagulation of platelets and endothelial cells (ECs) stimulated by NETs were measured by IF and flow cytometry. Thrombosis in vivo was measured in an established mice model of VTE induced by flow stenosis in the inferior vena cave (IVC).Result: NETs are likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies that GC cells and their conditioned medium (CM), but not gastric mucosal epithelial cell can stimulate NETs releasing from neutrophils. In addition, NETs induced hypercoagulation of platelets by up-regulating the expression of phosphatidylserine (PS) and P-selectin on the cells. Furhter, NETs stimulate adhesion of normal platelets on glass surfaces. Similarly, NETs trigger the conversion of ECs to hypercoagulable phenotypes by down-regulating the expression of their intercellular tight junctions but up-regulating that of tissue factor (TF). Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin generation and TAT complex. Meanwhile, in the models of IVC stenosis, tumor-bearing mice demonstrate stronger ability to form thrombi and NETs were abundantly accumulated in the thrombi compared with control mice. Notably, combination of DNase-1, activated protein C (APC) and Sivelestat markedly abolished the PCA of NETs.Conclusion: Our findings demonstrate that GC-induced NETs strongly increase the risks of VTE development both in vitro and in vivo. Given that inhibitors of NETs disrupt hypercoagulation, NETs are potential therapeutic target against VTE.

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.

Neutrophil Extracellular Traps Participate in the Development of Gastric Cancer Associated Thrombosis

2021 ◽  
Author(s):  
Jiacheng Li ◽  
Xiaoming Zou ◽  
Shifeng Yang ◽  
Jiaqi Jin ◽  
Lei Zhu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Activated Protein C ◽  
Neutrophil Extracellular Traps ◽  
Tissue Samples ◽  
Extracellular Traps ◽  
Fibrin Formation ◽  
Inferior Vena Cave ◽  
Cancer Associated Thrombosis

Abstract Background: Development of venous thromboembolism (VTE) is associated with high mortalities among gastric cancer (GC) patients. Neutrophil extracellular traps (NETs) have been reported to correlated with prothrombotic state in some diseases. We hypothesize that NETs participate in the development of GC-associated thrombosis.Methods: The level of NETs in blood and tissue samples of patients were analyzed by ELISA, flow cytometry and immunofluorescence (IF). NETs generation and hypercoagulation of platelets and endothelial cells (ECs) in vitro were observed by IF. NETs procoagulant activity (PCA) was performed by fibrin formation and thrombin-antithrombin complex (TAT) assays. Thrombosis in vivo was measured in murine model induced by flow stenosis in the inferior vena cave (IVC).Results: NETs were likely to form in blood and tissue samples of GC patients compared with healthy individuals. In vitro studies that GC cells and their conditioned medium (CM), but not gastric mucosal epithelial cell can stimulate NETs releasing from neutrophils. In addition, NETs induced hypercoagulable state of platelets by up-regulating the expression of phosphatidylserine (PS) and P-selectin on the cells. Furhter, NETs stimulated adhesion of normal platelets on glass surfaces. Similarly, NETs triggered the conversion of ECs to hypercoagulable phenotypes by down-regulating the expression of their intercellular tight junctions but up-regulating that of tissue factor (TF). Treatment of normal platelets or ECs with NETs augmented the level of plasma fibrin formation and TAT complex. Meanwhile, in the models of IVC stenosis, tumor-bearing mice showed stronger ability to form thrombi and NETs were abundantly accumulated in the thrombi compared with control mice. Notably, combination of DNase-1, activated protein C (APC) and Sivelestat markedly abolished the PCA of NETs.Conclusions: Our findings demonstrate that GC-induced NETs strongly increase the risks of VTE development both in vitro and in vivo. NETs are potential therapeutic targets in the prevention and treatment of VTE in GC patients.

scholarly journals Neutrophil Extracellular Traps Facilitate Sympathoexcitation After Traumatic Brain Injury Via HMGB1/AP1 Signaling Pathway

2021 ◽  
Author(s):  
Kaixin Zhu ◽  
Xiaoxiang Hou ◽  
Xiaolin Qu ◽  
Wen Chen ◽  
Kun Chen ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Diffuse Axonal Injury ◽  
Neutrophil Extracellular Traps ◽  
Control Group ◽  
Extracellular Traps ◽  
Important Form

Abstract Background: Traumatic brain injury (TBI) usually accompanies with sympathetic excitation, and paradoxical sympathetic hyperactivity (PSH) may be detrimental to the prognosis of TBI sufferers. Neutrophils can form neutrophil extracellular traps (NETs) to get involved in the neuroinflammation after TBI. As an important form of NETs, HMGB1 were found to activate the expression of AP1, which can increase the formation of IL-1β in microglia. Considering that IL-1β is able to regulate sympathoexcitation, it is reasonable to infer that HMGB1/AP1 signaling plays an important role in sympathoexcitation after TBI. Methods: In this present study, rat model with diffuse axonal injury (DAI) was established. The existance of NETs and the expression level of HMGB1/AP1/IL-1β in the paraventricular nucleus (PVN) after DAI were examined by immunofluorescence and Western blot (WB). The role of HMGB1/AP1 in the activation of microglia, secretion of IL-1β and sympathoexcitaiton were identified in vitro. Moreover, stereotaxic injection of anti-HMGB1 or HMGB1 was conducted to further validate the effect of HMGB1/AP1 pathway on sympathoexcitation after TBI.Results: The indicators of sympathoexcitation, including mean arterial pressure and serum catecholamine, increased and peaked at 72 hours after TBI. The formation of NETs was observed in PVN after injury, whereas, no NETs were found in the control group. And meanwhile, levels of NETs in PVN were higher than that in the para-PVN tissues after the injury. In vitro experiments showed that HMGB1 can promote the activation of microglia as well as increase the expression of AP1 and IL-1β. In vivo experiments suggested HMGB1 have an impact on the expression of AP1 and IL-1β in the PVN, and further controlling the sympathoexcitation after TBI.Conclusion: NETs might mediate sympathoexcitation after TBI through microglial activation in the PVN in a HMGB1/AP1/IL-1β dependent way.

scholarly journals Neutrophil Extracellular Traps (NETs) Take the Central Stage in Driving Autoimmune Responses

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 915 ◽  
Author(s):  
Esther Fousert ◽  
René Toes ◽  
Jyaysi Desai
Keyword(s):  
Autoimmune Diseases ◽  
Lupus Erythematosus ◽  
Current Knowledge ◽  
Neutrophil Extracellular Traps ◽  
Clinical Diagnostics ◽  
Extracellular Traps ◽  
Self Tolerance ◽  
Antigen Presenting

Following fifteen years of research, neutrophil extracellular traps (NETs) are widely reported in a large range of inflammatory infectious and non-infectious diseases. Cumulating evidences from in vitro, in vivo and clinical diagnostics suggest that NETs may play a crucial role in inflammation and autoimmunity in a variety of autoimmune diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Most likely, NETs contribute to breaking self-tolerance in autoimmune diseases in several ways. During this review, we discuss the current knowledge on how NETs could drive autoimmune responses. NETs can break self-tolerance by being a source of autoantigens for autoantibodies found in autoimmune diseases, such as anti-citrullinated protein antibodies (ACPAs) in RA, anti-dsDNA in SLE and anti-myeloperoxidase and anti-protein 3 in AAV. Moreover, NET components could accelerate the inflammatory response by mediating complement activation, acting as danger-associated molecular patterns (DAMPs) and inflammasome activators, for example. NETs also can activate other immune cells, such as B cells, antigen-presenting cells and T cells. Additionally, impaired clearance of NETs in autoimmune diseases prolongs the presence of active NETs and their components and, in this way, accelerate immune responses. NETs have not only been implicated as drivers of inflammation, but also are linked to resolution of inflammation. Therefore, NETs may be central regulators of inflammation and autoimmunity, serve as biomarkers, as well as promising targets for future therapeutics of inflammatory autoimmune diseases.

scholarly journals Activation of MAT2A-RIP1 signaling axis reprograms monocytes in gastric cancer

2021 ◽  
Vol 9 (2) ◽  
pp. e001364
Author(s):  
Yan Zhang ◽  
Hui Yang ◽  
Jun Zhao ◽  
Ping Wan ◽  
Ye Hu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Metabolism ◽  
Vital Role ◽  
Methionine Metabolism ◽  
Promoter Regions ◽  
Normal Tissues ◽  
Methionine Cycle

BackgroundThe activation of tumor-associated macrophages (TAMs) facilitates the progression of gastric cancer (GC). Cell metabolism reprogramming has been shown to play a vital role in the polarization of TAMs. However, the role of methionine metabolism in function of TAMs remains to be explored.MethodsMonocytes/macrophages were isolated from peripheral blood, tumor tissues or normal tissues from healthy donors or patients with GC. The role of methionine metabolism in the activation of TAMs was evaluated with both in vivo analyses and in vitro experiments. Pharmacological inhibition of the methionine cycle and modulation of key metabolic genes was employed, where molecular and biological analyses were performed.ResultsTAMs have increased methionine cycle activity that are mainly attributed to elevated methionine adenosyltransferase II alpha (MAT2A) levels. MAT2A modulates the activation and maintenance of the phenotype of TAMs and mediates the upregulation of RIP1 by increasing the histone H3K4 methylation (H3K4me3) at its promoter regions.ConclusionsOur data cast light on a novel mechanism by which methionine metabolism regulates the anti-inflammatory functions of monocytes in GC. MAT2A might be a potential therapeutic target for cancer cells as well as TAMs in GC.

scholarly journals The state of art of neutrophil extracellular traps in protozoan and helminthic infections

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
César Díaz-Godínez ◽  
Julio C. Carrero
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Parasitic Infections ◽  
Parasitic Diseases ◽  
Helminth Parasites ◽  
Extracellular Traps ◽  
Helminthic Infections ◽  
Bacteria And Fungi ◽  
Net Release

AbstractNeutrophil extracellular traps (NETs) are DNA fibers associated with histones, enzymes from neutrophil granules and anti-microbial peptides. NETs are released in a process denominated NETosis, which involves sequential steps that culminate with the DNA extrusion. NETosis has been described as a new mechanism of innate immunity related to defense against different pathogens. The initial studies of NETs were carried out with bacteria and fungi, but currently a large variety of microorganisms capable of inducing NETs have been described including protozoan and helminth parasites. Nevertheless, we have little knowledge about how NETosis process is carried out in response to the parasites, and about its implication in the resolution of this kind of disease. In the best case, the NETs entrap and kill parasites in vitro, but in others, immobilize the parasites without affecting their viability. Moreover, insufficient studies on the NETs in animal models of infections that would help to define their role, and the association of NETs with chronic inflammatory pathologies such as those occurring in several parasitic infections have left open the possibility of NETs contributing to pathology instead of protection. In this review, we focus on the reported mechanisms that lead to NET release by protozoan and helminth parasites and the evidence that support the role of NETosis in the resolution or pathogenesis of parasitic diseases.

scholarly journals Review: The endless nutritional and pharmaceutical benefits of the Himalayan gold, Cordyceps; Current knowledge and prospective potentials

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Waill Elkhateeb ◽  
Ghoson Daba
Keyword(s):  
Current Knowledge ◽  
Health Benefits ◽  
Chemical Compounds ◽  
Food Supplement ◽  
In Vivo Studies ◽  
Protective Agent ◽  
Global Marketplace

Abstract. Elkhateeb WA, Daba GM. 2020. Review: The endless nutritional and pharmaceutical benefits of the Himalayan gold, Cordyceps; Current knowledge and prospective potentials. Biofarmasi J Nat Prod Biochem 18: 70-77. As a traditional medicine, Cordyceps has long been used in Asian nations for maintaining vivacity and boosting immunity. Numerous publications on various bioactivities of Cordyceps have been investigated in both in-vitro as well as in vivo studies. Nevertheless, the role of Cordyceps is still arguable whether it acts as food supplement for health benefits or a real healing drug that can be prescribed in medicine. The Cordyceps industry has developed greatly and offers thousands of products, commonly available in a global marketplace. In this review, focus will be on introducing the ecology of Cordyceps and their classification. Moreover, elucidation of the richness of extracts originated from this mushroom in nutritional components was presented, with description of the chemical compounds of Cordyceps and its well-known compounds such as cordycepin, and cordycepic acid. Furthermore, highlights on natural growth and artificial cultivation of famous Cordyceps species were presented. The health benefits and reported bioactivities of Cordyceps species as promising antimicrobial, anticancer, hypocholesterolemic, antioxidant, antiviral, anti-inflammatory, organ protective agent, and enhancer for organ function were presented.

scholarly journals ELISA detection of MPO-DNA complexes in human plasma is error-prone and yields limited information on neutrophil extracellular traps formed in vivo

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250265
Author(s):  
Hubert Hayden ◽  
Nahla Ibrahim ◽  
Johannes Klopf ◽  
Branislav Zagrapan ◽  
Lisa-Marie Mauracher ◽  
...  
Keyword(s):  
Human Plasma ◽  
Dynamic Range ◽  
Neutrophil Extracellular Traps ◽  
Plasma Samples ◽  
Dna Complexes ◽  
High Background ◽  
Isotype Control ◽  
Extracellular Traps

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.

scholarly journals Neutrophil Extracellular Traps in Periodontitis

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1494 ◽  
Author(s):  
Antonio Magán-Fernández ◽  
Sarmad Muayad Rasheed Al-Bakri ◽  
Francisco O’Valle ◽  
Cristina Benavides-Reyes ◽  
Francisco Abadía-Molina ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Decisive Role ◽  
Neutrophil Extracellular Traps ◽  
Gingival Tissue ◽  
Multifactorial Disease ◽  
Extracellular Traps ◽  
Wide Range ◽  
Neutrophil Response ◽  
Inflammatory Component

Neutrophils are key cells of the immune system and have a decisive role in fighting foreign pathogens in infectious diseases. Neutrophil extracellular traps (NETs) consist of a mesh of DNA enclosing antimicrobial peptides and histones that are released into extracellular space following neutrophil response to a wide range of stimuli, such as pathogens, host-derived mediators and drugs. Neutrophils can remain functional after NET formation and are important for periodontal homeostasis. Periodontitis is an inflammatory multifactorial disease caused by a dysbiosis state between the gingival microbiome and the immune response of the host. The pathogenesis of periodontitis includes an immune-inflammatory component in which impaired NET formation and/or elimination can be involved, contributing to an exacerbated inflammatory reaction and to the destruction of gingival tissue. In this review, we summarize the current knowledge about the role of NETs in the pathogenesis of periodontitis.

Sign in / Sign up

Export Citation Format

Share Document