scholarly journals Contemporary Lifestyle and Neutrophil Extracellular Traps: An Emerging Link in Atherosclerosis Disease

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1985
Author(s):  
Laura Pérez-Olivares ◽  
Oliver Soehnlein
Keyword(s):  
Cardiovascular Disease ◽  
Genetic Material ◽  
Atherosclerotic Lesion ◽  
Active Role ◽  
Cell Types ◽  
Neutrophil Extracellular Traps ◽  
Major Elements ◽  
Immune Defense ◽  
Extracellular Traps ◽  
Extracellular Structures

Neutrophil extracellular traps (NETs) are networks of extracellular genetic material decorated with proteins of nuclear, granular and cytosolic origin that activated neutrophils expel under pathogenic inflammatory conditions. NETs are part of the host’s innate immune defense system against invading pathogens. Interestingly, these extracellular structures can also be released in response to sterile inflammatory stimuli (e.g., shear stress, lipidic molecules, pro-thrombotic factors, aggregated platelets, or pro-inflammatory cytokines), as in atherosclerosis disease. Indeed, NETs have been identified in the intimal surface of diseased arteries under cardiovascular disease conditions, where they sustain inflammation via NET-mediated cell-adhesion mechanisms and promote cellular dysfunction and tissue damage via NET-associated cytotoxicity. This review will focus on (1) the active role of neutrophils and NETs as underestimated players of the inflammatory process during atherogenesis and lesion progression; (2) how these extracellular structures communicate with the main cell types present in the atherosclerotic lesion in the arterial wall; and (3) how these neutrophil effector functions interplay with lifestyle-derived risk factors such as an unbalanced diet, physical inactivity, smoking or lack of sleep quality, which represent major elements in the development of cardiovascular disease.

scholarly journals Neutrophil Extracellular Traps Serve as Key Effector Molecules in the Protection Against Phialophora verrucosa

2021 ◽  
Vol 186 (3) ◽  
pp. 367-375
Author(s):  
Qin Liu ◽  
Wenjuan Yi ◽  
Si Jiang ◽  
Jiquan Song ◽  
Pin Liang
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Immune Effector ◽  
Phialophora Verrucosa ◽  
Extracellular Traps ◽  
Sytox Green ◽  
Innate Immune Effector ◽  
Pathogen Control ◽  
Extracellular Structures

AbstractPhialophora verrucosa (P. verrucosa) is a pathogen that can cause chromoblastomycosis and phaeohyphomycosis. Recent evidence suggests that neutrophils can produce neutrophil extracellular traps (NETs) that can protect against invasive pathogens. As such, we herein explored the in vitro functional importance of P. verrucosa-induced NET formation. By assessing the co-localization of neutrophil elastase and DNA, we were able to confirm the formation of classical NETs entrapping P. verrucosa specimens. Sytox Green was then used to stain these NETs following neutrophil infection with P. verrucosa in order to quantify the formation of these extracellular structures. NET formation was induced upon neutrophil exposure to both live, UV-inactivated, and dead P. verrucosa fungi. The ability of these NETs to kill fungal hyphae and conidia was demonstrated through MTT and pouring plate assays, respectively. Overall, our results confirmed that P. verrucosa was able to trigger the production of NETs, suggesting that these extracellular structures may represent an important innate immune effector mechanism controlling physiological responses to P. verrucosa infection, thereby aiding in pathogen control during the acute phases of infection.

scholarly journals ETosis: A Microbicidal Mechanism beyond Cell Death

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Anderson B. Guimarães-Costa ◽  
Michelle T. C. Nascimento ◽  
Amanda B. Wardini ◽  
Lucia H. Pinto-da-Silva ◽  
Elvira M. Saraiva
Keyword(s):  
Cell Death ◽  
Mast Cells ◽  
Cell Types ◽  
Neutrophil Extracellular Traps ◽  
Protozoan Parasites ◽  
Extracellular Milieu ◽  
Extracellular Traps ◽  
Cytoplasmic Proteins

Netosis is a recently described type of neutrophil death occurring with the release to the extracellular milieu of a lattice composed of DNA associated with histones and granular and cytoplasmic proteins. These webs, initially named neutrophil extracellular traps (NETs), ensnare and kill microorganisms. Similarly, other cell types, such as eosinophils, mast cells, and macrophages, can also dye by this mechanism; thus, it was renamed as ETosis, meaning death with release of extracellular traps (ETs). Here, we review the mechanism of NETosis/etosis, emphasizing its role in diseases caused by protozoan parasites, fungi, and viruses.

Exosomal MALAT1 derived from ox-LDL-treated endothelial cells induce neutrophil extracellular traps to aggravate atherosclerosis

2020 ◽  
Vol 401 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Hailai Gao ◽  
XiaoLi Wang ◽  
Chaolan Lin ◽  
Zhujun An ◽  
Jiangbo Yu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Low Density Lipoprotein ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
Neutrophil Extracellular Traps ◽  
Human Neutrophils ◽  
Enzyme Linked Immunosorbent Assay ◽  
Extracellular Traps ◽  
Umbilical Vein Endothelial Cells

AbstractThe objective of this study was to reveal a novel mechanism underlying the progression of atherosclerosis (AS) associated with endothelial cells (ECs) and neutrophils. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were used to observe the morphology and particle size of isolated exosomes. Western blotting was applied to examine exosomal markers, while the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The production of inflammatory cytokines and reactive oxygen species (ROS) was determined by an enzyme-linked immunosorbent assay (ELISA) and a dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. Circulating neutrophil extracellular traps (NETs) were represented by myeloperoxidase (MPO)-DNA complexes. NETs formation was assessed using immunofluorescence microscopy. Atherosclerotic lesion development was measured by Oil Red O (ORO) staining. In the results, MALAT1 expression was increased in exosomes extracted from oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs). When co-cultured with human neutrophils, exosomes derived from ox-LDL-treated HUVECs were revealed to promote NETs formation, which was mediated by exosomal MALAT1. Furthermore, ox-LDL-treated HUVECs-derived exosomes were demonstrated to trigger hyperlipidemia, inflammatory response and NETs release in a mouse model of AS. In conclusion, exosomal MALAT1 derived from ox-LDL-treated ECs initiated NETs formation, which in turn deteriorated AS.

scholarly journals How Neutrophil Extracellular Traps Become Visible

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Nicole de Buhr ◽  
Maren von Köckritz-Blickwede
Keyword(s):  
Electron Microscopy ◽  
Nuclear Dna ◽  
Defense Mechanism ◽  
Neutrophil Extracellular Traps ◽  
Immune Defense ◽  
Extracellular Traps ◽  
Activated Neutrophils ◽  
Microscopy Techniques

Neutrophil extracellular traps (NETs) have been identified as a fundamental innate immune defense mechanism against different pathogens. NETs are characterized as released nuclear DNA associated with histones and granule proteins, which form an extracellular web-like structure that is able to entrap and occasionally kill certain microbes. Furthermore, NETs have been shown to contribute to several noninfectious disease conditions when released by activated neutrophils during inflammation. The identification of NETs has mainly been succeeded by various microscopy techniques, for example, immunofluorescence microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Since the last years the development and improvement of new immunofluorescence-based techniques enabled optimized visualization and quantification of NETs. On the one handin vitrolive-cell imaging led to profound new ideas about the mechanisms involved in the formation and functionality of NETs. On the other hand different intravital,in vivo, andin situmicroscopy techniques led to deeper insights into the role of NET formation during health and disease. This paper presents an overview of the main used microscopy techniques to visualize NETs and describes their advantages as well as disadvantages.

scholarly journals Novel cell death program leads to neutrophil extracellular traps

2007 ◽  
Vol 176 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Tobias A. Fuchs ◽  
Ulrike Abed ◽  
Christian Goosmann ◽  
Robert Hurwitz ◽  
Ilka Schulze ◽  
...  
Keyword(s):  
Cell Death ◽  
Nadph Oxidase ◽  
Neutrophil Extracellular Traps ◽  
Death Process ◽  
Extracellular Traps ◽  
Cell Death Pathway ◽  
Antimicrobial Function ◽  
Cell Death Program ◽  
Cell Death Process ◽  
Extracellular Structures

Neutrophil extracellular traps (NETs) are extracellular structures composed of chromatin and granule proteins that bind and kill microorganisms. We show that upon stimulation, the nuclei of neutrophils lose their shape, and the eu- and heterochromatin homogenize. Later, the nuclear envelope and the granule membranes disintegrate, allowing the mixing of NET components. Finally, the NETs are released as the cell membrane breaks. This cell death process is distinct from apoptosis and necrosis and depends on the generation of reactive oxygen species (ROS) by NADPH oxidase. Patients with chronic granulomatous disease carry mutations in NADPH oxidase and cannot activate this cell-death pathway or make NETs. This novel ROS-dependent death allows neutrophils to fulfill their antimicrobial function, even beyond their lifespan.

Platelet Toll-Like Receptors: Bridging Inflammation and Immunity

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. SCI-45-SCI-45
Author(s):  
Paul Kubes
Keyword(s):  
Immune Cells ◽  
Conflicts Of Interest ◽  
Detection System ◽  
Vascular Dysfunction ◽  
Cell Types ◽  
Neutrophil Extracellular Traps ◽  
Extracellular Traps ◽  
Almost All ◽  
Different Cell Types

Abstract Since the discovery that there is a series of pattern recognition receptors that allow the immune system to detect pathogens, there has been a lot of work to elucidate the signaling molecules that contribute to this detection system. Although the cell types involved would seem to be just as important, our understanding of which cells are critical remains less well explored. Using intravital imaging to visualize the different cell types, we were surprised to find that in almost all conditions that we examined, platelets were rapidly recruited to afflicted tissues. Under some conditions, platelets bound vascular macrophage including Kupffer cells and helped contain bacteria. These were instantaneous responses. At later times, platelets bound neutrophils and induced the production of neutrophil extracellular traps (NETs) that helped to catch bacteria as well as viruses but did induce some local vascular injury. In some scenarios, platelets bound endothelial cells and whether this was to wall off and contain infections or a hijacking of platelets by bacteria to induce vascular dysfunction and poor perfusion remains unclear. Visualizing platelets in sterile injury also revealed important contributions to helping recruit other immune cells that help to heal. The role of the platelet as an effector in infections and inflammation will be discussed. Disclosures No relevant conflicts of interest to declare.

scholarly journals Secreted Phosphatase and Deoxyribonuclease Are Required by Pseudomonas aeruginosa To Defend against Neutrophil Extracellular Traps

2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Mike Wilton ◽  
Tyler W. R. Halverson ◽  
Laetitia Charron-Mazenod ◽  
Michael D. Parkins ◽  
Shawn Lewenza
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Alkaline Phosphatase ◽  
Defense Mechanism ◽  
Neutrophil Extracellular Traps ◽  
Immune Defense ◽  
Extracellular Dna ◽  
Protective Function ◽  
Content Type ◽  
Extracellular Traps

ABSTRACT Neutrophil extracellular traps (NETs) are produced by neutrophils as an innate immune defense mechanism to trap and kill microbial pathogens. NETs are comprised of ejected chromatin that forms a lattice structure enmeshed with numerous antimicrobial proteins. In addition to forming the structural backbone of NETs, extracellular DNA (eDNA) has membrane-disrupting antimicrobial activity that contributes to NET killing. Many pathogens produce secreted extracellular DNases to evade the antimicrobial activity of NETs. Pseudomonas aeruginosa encodes an operon of two secreted enzymes, a predicted alkaline phosphatase and a DNase. The DNase (eddB) degrades eDNA to use as a nutrient source. Here we report that both eDNA and NETs are potent inducers of this DNase-phosphatase operon. Furthermore, the secreted DNase contributes to degrading NET DNA and defends P. aeruginosa against NET-mediated killing. We demonstrate that EddA has both alkaline phosphatase and phosphodiesterase (PDase) activities and also protects against the antimicrobial activity of NETs. Although the phosphatase does not cause DNA degradation similar to that of the DNase, its protective function is likely a result of removing the cation-chelating phosphates from the eDNA phosphodiester backbone. Therefore, both the DNase and PDase contribute to defense against NET killing of P. aeruginosa, highlighting the role of DNA-manipulating enzymes in targeting the eDNA in neutrophil extracellular traps.

scholarly journals The Role of DNA in the Extracellular Environment: A Focus on NETs, RETs and Biofilms

2020 ◽  
Vol 11 ◽  
Author(s):  
Francesco Monticolo ◽  
Emanuela Palomba ◽  
Pasquale Termolino ◽  
Pasquale Chiaiese ◽  
Elisabetta de Alteriis ◽  
...  
Keyword(s):  
Genetic Material ◽  
Active Role ◽  
Protective Role ◽  
Extracellular Dna ◽  
Extracellular Matrices ◽  
Pathogen Invasion ◽  
Extracellular Traps ◽  
Molecular Pattern ◽  
Extracellular Environment

The capacity to actively release genetic material into the extracellular environment has been reported for bacteria, archaea, fungi, and in general, for microbial communities, but it is also described in the context of multicellular organisms, animals and plants. This material is often present in matrices that locate outside the cells. Extracellular matrices have important roles in defense response and disease in microbes, animal and plants cells, appearing as barrier against pathogen invasion or for their recognition. Specifically, neutrophils extracellular traps (NETs) in animals and root extracellular traps (RETs) in plants, are recognized to be important players in immunity. A growing amount of evidence revealed that the extracellular DNA, in these contexts, plays an active role in the defense action. Moreover, the protective role of extracellular DNA against antimicrobials and mechanical stress also appears to be confirmed in bacterial biofilms. In parallel, recent efforts highlighted different roles of self (homologous) and non-self (heterologous) extracellular DNA, paving the way to discussions on its role as a “Damage-associated molecular pattern” (DAMP). We here provide an evolutionary overview on extracellular DNA in extracellular matrices like RETs, NETs, and microbial biofilms, discussing on its roles and inferring on possible novel functionalities.

scholarly journals Neutrophil Extracellular Traps and Liver Disease

2019 ◽  
Vol 40 (02) ◽  
pp. 171-179 ◽  
Author(s):  
Moira B. Hilscher ◽  
Vijay H. Shah
Keyword(s):  
Liver Disease ◽  
Liver Diseases ◽  
Therapeutic Potential ◽  
Neutrophil Extracellular Traps ◽  
Clinical Applications ◽  
Immune Defense ◽  
Extracellular Dna ◽  
Risk Of Infection ◽  
Extracellular Traps ◽  
Increased Risk

AbstractNeutrophil extracellular traps, or NETs, are heterogenous, filamentous structures which consist of extracellular DNA, granular proteins, and histones. NETs are extruded by a neutrophil in response to various stimuli. Although NETs were initially implicated in immune defense, subsequent studies have implicated NETs in a spectrum of disease processes, including autoimmune disease, thrombosis, and cancer. NETs also contribute to the pathogenesis of several common liver diseases, including alcohol-associated liver disease and portal hypertension. Although there is much interest in the therapeutic potential of NET inhibition, future clinical applications must be balanced against potential increased risk of infection.

scholarly journals Neutrophil Extracellular Traps Affecting Cardiovascular Health in Infectious and Inflammatory Diseases

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1689
Author(s):  
Manovriti Thakur ◽  
Bryce Evans ◽  
Marc Schindewolf ◽  
Iris Baumgartner ◽  
Yvonne Döring
Keyword(s):  
Cardiovascular Health ◽  
Viral Infections ◽  
Inflammatory Diseases ◽  
Vascular Inflammation ◽  
Neutrophil Extracellular Traps ◽  
Immune Defense ◽  
Future Research ◽  
Extracellular Traps ◽  
Infection And Inflammation

Neutrophil extracellular traps (NETs) are web-like structures of decondensed extracellular chromatin fibers and neutrophil granule proteins released by neutrophils. NETs participate in host immune defense by entrapping pathogens. They are pro-inflammatory in function, and they act as an initiator of vascular coagulopathies by providing a platform for the attachment of various coagulatory proteins. NETs are diverse in their ability to alter physiological and pathological processes including infection and inflammation. In this review, we will summarize recent findings on the role of NETs in bacterial/viral infections associated with vascular inflammation, thrombosis, atherosclerosis and autoimmune disorders. Understanding the complex role of NETs in bridging infection and chronic inflammation as well as discussing important questions related to their contribution to pathologies outlined above may pave the way for future research on therapeutic targeting of NETs applicable to specific infections and inflammatory disorders.

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