scholarly journals Neutrophil extracellular traps drive inflammatory pathogenesis in malaria

2019 ◽  
Vol 4 (40) ◽  
pp. eaaw0336 ◽  
Author(s):  
Sebastian Lorenz Knackstedt ◽  
Athina Georgiadou ◽  
Falko Apel ◽  
Ulrike Abu-Abed ◽  
Christopher A. Moxon ◽  
...  
Keyword(s):  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Intercellular Adhesion Molecule ◽  
Granulocyte Colony Stimulating Factor ◽  
Tissue Destruction ◽  
Intercellular Adhesion Molecule 1 ◽  
Immunostimulatory Activity ◽  
Extracellular Traps ◽  
Vascular Infections ◽  
Stimulating Factor

Neutrophils are essential innate immune cells that extrude chromatin in the form of neutrophil extracellular traps (NETs) when they die. This form of cell death has potent immunostimulatory activity. We show that heme-induced NETs are essential for malaria pathogenesis. Using patient samples and a mouse model, we define two mechanisms of NET-mediated inflammation of the vasculature: activation of emergency granulopoiesis via granulocyte colony-stimulating factor production and induction of the endothelial cytoadhesion receptor intercellular adhesion molecule–1. Soluble NET components facilitate parasite sequestration and mediate tissue destruction. We demonstrate that neutrophils have a key role in malaria immunopathology and propose inhibition of NETs as a treatment strategy in vascular infections.

scholarly journals Orchestration of Neutrophil Extracellular Traps (Nets), a Unique Innate Immune Function during Chronic Obstructive Pulmonary Disease (COPD) Development

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 53
Author(s):  
Anjali Trivedi ◽  
Meraj A. Khan ◽  
Geetanjali Bade ◽  
Anjana Talwar
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Chronic Obstructive ◽  
Tissue Destruction ◽  
Mucus Production ◽  
Obstructive Pulmonary Disease ◽  
Extracellular Traps ◽  
Endothelial Cell Death

Morbidity, mortality and economic burden caused by chronic obstructive pulmonary disease (COPD) is a significant global concern. Surprisingly, COPD is already the third leading cause of death worldwide, something that WHO had not predicted to occur until 2030. It is characterized by persistent respiratory symptoms and airway limitation due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles of gases. Neutrophil is one of the key infiltrated innate immune cells in the lung during the pathogenesis of COPD. Neutrophils during pathogenic attack or injury decide to undergo for a suicidal death by releasing decondensed chromatin entangled with antimicrobial peptides to trap and ensnare pathogens. Casting neutrophil extracellular traps (NETs) has been widely demonstrated to be an effective mechanism against invading microorganisms thus controlling overwhelming infections. However, aberrant and massive NETs formation has been reported in several pulmonary diseases, including chronic obstructive pulmonary disease. Moreover, NETs can directly induce epithelial and endothelial cell death resulting in impairing pulmonary function and accelerating the progression of the disease. Therefore, understanding the regulatory mechanism of NET formation is the need of the hour in order to use NETs for beneficial purpose and controlling their involvement in disease exacerbation. For example, DNA neutralization of NET proteins using protease inhibitors and disintegration with recombinant human DNase would be helpful in controlling excess NETs. Targeting CXC chemokine receptor 2 (CXCR2) would also reduce neutrophilic inflammation, mucus production and neutrophil-proteinase mediated tissue destruction in lung. In this review, we discuss the interplay of NETs in the development and pathophysiology of COPD and how these NETs associated therapies could be leveraged to disrupt NETopathic inflammation as observed in COPD, for better management of the 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 Nanomaterial Exposure Induced Neutrophil Extracellular Traps: A New Target in Inflammation and Innate Immunity

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Hang Yang ◽  
Tony N. Marion ◽  
Yi Liu ◽  
Lingshu Zhang ◽  
Xue Cao ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Immune Responses ◽  
Myeloid Cell ◽  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Cell Type ◽  
Extracellular Traps ◽  
Pharmaceutical Industries ◽  
The Relationship

Nanotechnology has become a novel subject with impact in many research and technology areas. Nanoparticles (NPs), as a key component in nanotechnology, are widely used in many areas such as optical, magnetic, electrical, and mechanical engineering. The biomedical and pharmaceutical industries have embraced NPs as a viable drug delivery modality. As such, the potential for NP-induced cytotoxicity has emerged as a major concern for NP drug delivery systems. Thus, it is important to understand how NPs affect the innate immune system. As the most abundant myeloid cell type in innate immune responses, neutrophils are critical for concerns about potentially toxic side effects of NPs. When activated by innate immune stimuli, neutrophils may initiate NETosis to release neutrophil extracellular traps (NETs). Herein, we have reviewed the relationship between NPs and the induction of NETosis and release of NETs.

scholarly journals dsRNA activation of endothelin-1 and markers of vascular activation in endothelial cells and fibroblasts

2010 ◽  
Vol 70 (3) ◽  
pp. 544-550 ◽  
Author(s):  
Giuseppina Farina ◽  
Michael York ◽  
Cindy Collins ◽  
Robert Lafyatis
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Intercellular Adhesion ◽  
Dermal Fibroblasts ◽  
Innate Immune ◽  
Poly I:C ◽  
Intercellular Adhesion Molecule ◽  
Type I ◽  
Intercellular Adhesion Molecule 1 ◽  
Endothelin 1

BackgroundIn patients with systemic sclerosis (SSc), the relationship between innate immune activation, represented by increased expression of interferon (IFN)-regulated genes, and vascular injury/activation, manifest by increased endothelin-1 (ET-1), endothelin converting enzyme-1 (ECE1) and intercellular adhesion molecule-1, is uncertain.ObjectiveTo investigate the potential roles of innate immune ligands in both these pathogenic pathways.MethodsThe effect of known Toll-like receptor (TLR) ligands was tested in vitro on dermal microvascular and pulmonary arterial endothelial cells, and on dermal fibroblasts cultured from healthy controls and patients with SSc. To test the effect of double-stranded RNA (dsRNA) on vascular activation/injury in vivo, polyinosinic/polycytidylic acid (poly(I:C)) was administered continuously over 7 days by subcutaneous osmotic pump.ResultsdsRNA/poly(I:C), but not other TLR ligands, highly stimulated ET-1 protein and mRNA (EDN1), as well as intercellular adhesion molecule-1 (ICAM-1) and IFN-regulated MX2, by endothelial cells and dermal fibroblasts. Poly(I:C) induced EDN1, ECE1, and ICAM-1 mRNA expression in poly(I:C) treated skin. Poly(I:C)-induced EDN1, ECE1 and MX2 was not blocked in mice with the type I IFN receptor deleted. However, poly(I:C)-induced EDN1 and ECE1, but not poly(I:C)-induced ICAM-1 expression was blocked in mice with the TLR3 signalling protein TRIF/TICAM-1 deleted.ConclusionTogether these data show that the dsRNA can regulate genes associated with vascular activation, as seen in SSc, that type I IFNs do not mediate these effects, and that EDN1 and ECE1 but not ICAM-1 activation is mediated by TLR3.

scholarly journals Neutrophil Extracellular Traps Promote the Development of Intracranial Aneurysm Rupture

Hypertension ◽  
2021 ◽  
Author(s):  
Masaaki Korai ◽  
James Purcell ◽  
Yoshinobu Kamio ◽  
Kazuha Mitsui ◽  
Hajime Furukawa ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Interleukin 1 ◽  
Neutrophil Extracellular Traps ◽  
Aneurysm Rupture ◽  
Arginine Deiminase ◽  
Intercellular Adhesion Molecule ◽  
Necrosis Factor Alpha ◽  
Extracellular Traps ◽  
Peptidyl Arginine Deiminase ◽  
Aneurysm Wall

Potential roles for neutrophils in the pathophysiology of intracranial aneurysm have long been suggested by clinical observations. The presence of neutrophil enzymes in the aneurysm wall has been associated with significant increases in rupture risk. However, the mechanisms by which neutrophils may promote aneurysm rupture are not well understood. Neutrophil extracellular traps (NETs) were implicated in many diseases that involve inflammation and tissue remodeling, including atherosclerosis, vasculitis, and abdominal aortic aneurysm. Therefore, we hypothesized that NETs may promote the rupture of intracranial aneurysm, and that removal of NETs can reduce the rate of rupture. We employed both pharmacological and genetic approaches for the disruption of NETs and used a mouse model of intracranial aneurysm to investigate the roles of NETs in the development of intracranial aneurysm rupture. Here, we showed that NETs are detected in human intracranial aneurysms. Both global and granulocyte-specific knockout of peptidyl arginine deiminase 4 (an enzyme essential for NET formation) reduced the rate of aneurysm rupture. Pharmacological blockade of the NET formation by Cl-amidine also reduced the rate of aneurysm rupture. In addition, the resolution of already formed NETs by deoxyribonuclease was effective against aneurysm rupture. Inhibition of NETs formation with Cl-amidine decreased mRNA expression of proinflammatory cytokines (intercellular adhesion molecule 1 (ICAM-1), interleukin 1 beta (IL-1β), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor alpha (TNF-α)) in cerebral arteries. These data suggest that NETs promote the rupture of intracranial aneurysm. Pharmacological removal of NETs, by inhibition of peptidyl arginine deiminase 4 or resolution of already-formed NETs, may represent a potential therapeutic strategy for preventing aneurysmal rupture.

scholarly journals Angiopoietin 1 release from human neutrophils is independent from neutrophil extracellular traps (NETs)

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Elcha Charles ◽  
Benjamin L. Dumont ◽  
Steven Bonneau ◽  
Paul-Eduard Neagoe ◽  
Louis Villeneuve ◽  
...  
Keyword(s):  
Nuclear Dna ◽  
Neutrophil Extracellular Traps ◽  
Innate Immune ◽  
Human Neutrophils ◽  
Extracellular Traps ◽  
Pathological Conditions ◽  
Healthy Control ◽  
Angiopoietin 1

Abstract Background Neutrophils induce the synthesis and release of angiopoietin 1 (Ang1), a cytosolic growth factor involved in angiogenesis and capable of inducing several pro-inflammatory activities in neutrophils. Neutrophils also synthesize and release neutrophil extracellular traps (NETs), comprised from decondensed nuclear DNA filaments carrying proteins such as neutrophil elastase (NE), myeloperoxidase (MPO), proteinase 3 (PR3) and calprotectin (S100A8/S100A9), which together, contribute to the innate immune response against pathogens (e.g., bacteria). NETs are involved in various pathological conditions through pro-inflammatory, pro-thrombotic and endothelial dysfunction effects and have recently been found in heart failure (HF) and type 2 diabetes (T2DM) patients. The aim of the present study was to investigate the role of NETs on the synthesis and release of Ang1 by the neutrophils in patients with T2DM and HF with preserved ejection fraction (HFpEF) (stable or acute decompensated; ADHFpEF) with or without T2DM. Results Our data show that at basal level (PBS) and upon treatment with LPS, levels of NETs are slightly increased in patients suffering from T2DM, HFpEF ± T2DM and ADHF without (w/o) T2DM, whereas this increase was significant in ADHFpEF + T2DM patients compared to healthy control (HC) volunteers and ADHFpEF w/o T2DM. We also observed that treatments with PMA or A23187 increase the synthesis of Ang1 (from 150 to 250%) in HC and this effect is amplified in T2DM and in all cohorts of HF patients. Ang1 is completely released (100%) by neutrophils of all groups and does not bind to NETs as opposed to calprotectin. Conclusions Our study suggests that severely ill patients with HFpEF and diabetes synthesize and release a greater abundance of NETs while Ang1 exocytosis is independent of NETs synthesis.

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