scholarly journals Andrographolide Ameliorates Rheumatoid Arthritis by Regulating the Apoptosis–NETosis Balance of Neutrophils

2019 ◽  
Vol 20 (20) ◽  
pp. 5035 ◽  
Author(s):  
Xiaohong Li ◽  
Kai Yuan ◽  
Qingqing Zhu ◽  
Qingyi Lu ◽  
Haixu Jiang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Neutrophil Infiltration ◽  
Chronic Inflammatory Disease ◽  
Adjuvant Induced Arthritis ◽  
Extracellular Traps ◽  
Ankle Joints ◽  
Activated Neutrophils ◽  
Labdane Diterpenoid ◽  
Anti Inflammation

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by symmetric polyarthritis with swelling and pain at synovial joints. In RA patients, delayed neutrophil apoptosis amplifies the inflammatory response and massively released neutrophil extracellular traps (NETs) induce tissue damage and provide self-antigens. Andrographolide (AD) is the major active labdane diterpenoid derived from Andrographis paniculata, which has multiple pharmacological effects, including hepatoprotection, anti-angiogenesis, anti-thrombosis, and anti-inflammation. In the present study, we investigated the effect of AD on an adjuvant-induced arthritis (AA) murine model of RA and found that AD alleviated murine arthritis by reducing neutrophil infiltration and NETosis in the ankle joints and relieved the systematic inflammation. In vitro experiments showed that AD accelerated the apoptosis of lipopolysaccharide-activated neutrophils and inhibited autophagy-dependent extracellular traps formation of neutrophils. These findings suggest that AD has considerable potential for RA therapy.

scholarly journals Neutrophil extracellular traps are associated with altered human pulmonary artery endothelial barrier function

2021 ◽  
Vol 19 ◽  
pp. 205873922110623
Author(s):  
Hisatake Mori ◽  
Muhammad Aminul Huq ◽  
Md. Monirul Islam ◽  
Naoshi Takeyama
Keyword(s):  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Barrier Function ◽  
Neutrophil Extracellular Traps ◽  
Endothelial Barrier ◽  
Endothelial Barrier Function ◽  
Extracellular Traps ◽  
Activated Neutrophils ◽  
Human Pulmonary Artery

Introduction: Acute respiratory response syndrome (ARDS) leads to increased permeability of the endothelial-epithelial barrier, which in turn promotes edema formation and hypoxemic respiratory failure. Although activated neutrophils are thought to play a significant role in mediating ARDS, at present the contribution of neutrophil extracellular traps (NETs) to lung endothelial barrier function is unclear. Methods: To clarify their role, we co-cultured in vitro NETs induced by phorbol myristate acetate (PMA)–activated neutrophils with lung endothelial cell monolayers and examined the barrier function of lung endothelial cells by immunofluorescence microscopy and albumin permeability in a double-chamber culture method. Results: Co-culture with stimulated neutrophils increased the albumin permeability of the human pulmonary artery endothelial cell (HPAEC) monolayer and altered cytoskeleton F-actin and vascular endothelial-cadherin in cell-cell junctions. Hyperpermeability to albumin and histological alterations were prevented by inhibition of NET formation with peptidyl arginine deiminase inhibitor or a neutrophil elastase inhibitor and were also prevented by increased degradation of NET structure with DNase. Conclusion: This in vitro experiment shows that altered HPAEC barrier function and increased albumin permeability are caused by the direct effect of PMA-induced NETs and their components. NET formation may be involved in the increased vascular permeability of the lung, which is a common feature in ARDS of various etiologies. These insights may help generate novel approaches for medical interventions.

scholarly journals Neutrophil extracellular traps from healthy donors and HIV-1-infected individuals restrict HIV-1 production in macrophages

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrés Mojoli ◽  
Barbara Simonson Gonçalves ◽  
Jairo R. Temerozo ◽  
Bruno Cister-Alves ◽  
Victor Geddes ◽  
...  
Keyword(s):  
Virus Production ◽  
Significant Inhibition ◽  
Target Cells ◽  
Extracellular Traps ◽  
Healthy Donors ◽  
Activated Neutrophils ◽  
Immunity Mechanism ◽  
Anti Hiv ◽  
Hiv 1

Abstract Neutrophils release extracellular traps (NETs) after interaction with microorganisms and physiological or synthetic products. NETs consist of decondensed chromatin complexed with proteins, some of them with microbicidal properties. Because NETs can modulate the functioning of HIV-1 target cells, we aimed to verify whether they modify HIV-1 replication in macrophages. We found that exposure of HIV-1-infected macrophages to NETs resulted in significant inhibition of viral replication. The NET anti-HIV-1 action was independent of other soluble factors released by the activated neutrophils, but otherwise dependent on the molecular integrity of NETs, since NET-treatment with protease or DNase abolished this effect. NETs induced macrophage production of the anti-HIV-1 β-chemokines Rantes and MIP-1β, and reduced the levels of integrated HIV-1 DNA in the macrophage genome, which may explain the decreased virus production by infected macrophages. Moreover, the residual virions released by NET-treated HIV-1-infected macrophages lost infectivity. In addition, elevated levels of DNA-elastase complexes were detected in the plasma from HIV-1-infected individuals, and neutrophils from these patients released NETs, which also inhibited HIV-1 replication in in vitro infected macrophages. Our results reveal that NETs may function as an innate immunity mechanism able to restrain HIV-1 production in macrophages.

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 SARS-CoV-2–triggered neutrophil extracellular traps mediate COVID-19 pathology

2020 ◽  
Vol 217 (12) ◽  
Author(s):  
Flavio Protasio Veras ◽  
Marjorie Cornejo Pontelli ◽  
Camila Meirelles Silva ◽  
Juliana E. Toller-Kawahisa ◽  
Mikhael de Lima ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Tracheal Aspirate ◽  
Neutrophil Extracellular Traps ◽  
Angiotensin Converting Enzyme 2 ◽  
Extracellular Traps ◽  
Lung Epithelial ◽  
Activated Neutrophils ◽  
Epithelial Cell Death

Severe COVID-19 patients develop acute respiratory distress syndrome that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that neutrophil extracellular traps (NETs) have been described as important mediators of tissue damage in inflammatory diseases, we investigated whether NETs would be involved in COVID-19 pathophysiology. A cohort of 32 hospitalized patients with a confirmed diagnosis of COVID-19 and healthy controls were enrolled. The concentration of NETs was augmented in plasma, tracheal aspirate, and lung autopsies tissues from COVID-19 patients, and their neutrophils released higher levels of NETs. Notably, we found that viable SARS-CoV-2 can directly induce the release of NETs by healthy neutrophils. Mechanistically, NETs triggered by SARS-CoV-2 depend on angiotensin-converting enzyme 2, serine protease, virus replication, and PAD-4. Finally, NETs released by SARS-CoV-2–activated neutrophils promote lung epithelial cell death in vitro. These results unravel a possible detrimental role of NETs in the pathophysiology of COVID-19. Therefore, the inhibition of NETs represents a potential therapeutic target for COVID-19.

scholarly journals Microneedle-Assisted Transdermal Delivery of Etanercept for Rheumatoid Arthritis Treatment

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 235 ◽  
Author(s):  
Jian Cao ◽  
Nan Zhang ◽  
Ziyi Wang ◽  
Jingjing Su ◽  
Jing Yang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Transdermal Delivery ◽  
In Vitro Bioactivity ◽  
In Vivo Evaluation ◽  
Adjuvant Induced Arthritis ◽  
Tnf Α ◽  
Good Biocompatibility ◽  
New Treatment

Rheumatoid arthritis (RA) is a complicated autoimmune disease. The clinical applications of etanercept (EN), a TNF-α inhibitor, can efficiently halt the development of RA. EN is mainly administrated by subcutaneous injection, which may cause low compliance, side effects, and infection risk. In this study, a hyaluronic acid crosslinked microneedle system (MN) was constructed as the transdermal alternative to deliver EN. We describe the formulation, fabrication, characterization, and transdermal insertion study of MN. In vitro bioactivity of EN was conducted and analyzed by dynamic light scattering and circular dichroism spectrum. In vivo evaluation of MN was studied on adjuvant-induced arthritis mice. The MN possessed sufficient mechanical strength, good biocompatibility, little influence on the bioactivity of EN, and high anti-inflammatory efficacy. This work represents a successful example of delivering macromolecule therapeutic treatment by MN for RA treatment. The transdermal delivery of EN by MN offers a new treatment option for RA patients.

Phalloidin attenuates postischemic neutrophil infiltration and increased microvascular permeability

1991 ◽  
Vol 71 (4) ◽  
pp. 1261-1269 ◽  
Author(s):  
R. J. Korthuis ◽  
D. L. Carden ◽  
P. R. Kvietys ◽  
D. Shepro ◽  
J. Fuseler
Keyword(s):  
Cyclic Peptides ◽  
Neutrophil Infiltration ◽  
Microvascular Permeability ◽  
Fluorescent Detection ◽  
Tissue Samples ◽  
Activated Neutrophils ◽  
Muscle Changes ◽  
Granulocyte Function ◽  
Continuous Perfusion

The aim of this study was to determine whether phalloidin (1 microM) or antamanide (1 microM), cyclic peptides that stabilize dense peripheral band and stress fiber F-actin in endothelium, would attenuate the increase in microvascular permeability induced by 4 h of ischemia and 30 min of reperfusion (I/R) in the isolated canine gracilis muscle. Changes in microvascular permeability (1 - sigma) were assessed by determining the solvent drag reflection coefficient for total plasma proteins (sigma) in muscles subjected to 4.5 h of continuous perfusion (nonischemic controls), I/R alone, I/R + phalloidin, or I/R + antamanide. Muscle neutrophil content was assessed by determination of myeloperoxidase (MPO) activity in tissue samples obtained at the end of the experiments. Fluorescent detection of nitrobenzoxadiazole-phallicidin in endothelial cell monolayers confirmed that phalloidin enters these cells. I/R was associated with marked increases in microvascular permeability and muscle neutrophil content (1 - sigma = 0.45 +/- 0.07; MPO = 8.9 +/- 0.5 units/g) relative to control (4.5 h continuous perfusion) preparations (1 - sigma = 0.12 +/- 0.03; MPO = 0.5 +/- 0.8 unit/g). These I/R-induced changes were largely prevented by administration of phalloidin (1 - sigma = 0.19 +/- 0.02; MPO = 0.8 +/- 0.4 U/g) or antamanide (1 - sigma = 0.07 +/- 0.11; MPO = 0.9 +/- 0.3 unit/g) at reperfusion. Similar results were obtained when phalloidin was administered before ischemia (1 - sigma = 0.24 +/- 0.04; MPO = 1.2 +/- 1.0 units/g). Although antamanide decreased superoxide production (by approximately 60%) and adherence to plastic (by approximately 75%) by activated neutrophils in vitro, phalloidin failed to alter these aspects of granulocyte function.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Hsa_circ_0001859 Regulates ATF2 Expression by Functioning as an MiR-204/211 Sponge in Human Rheumatoid Arthritis

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bingrui Li ◽  
Nianyu Li ◽  
Le Zhang ◽  
Kai Li ◽  
Yingtian Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Chronic Inflammatory Disease ◽  
Functional Enrichment ◽  
Regulation Mechanism ◽  
Human Rheumatoid Arthritis ◽  
Loss Of Function ◽  
Mirna Sponges ◽  
Synovial Tissues ◽  
Inflammatory Regulation

Background. circRNAs are part of the competitive endogenous RNA network, which putatively function as miRNA sponges and play a crucial role in the development of numerous diseases. However, studies of circRNAs in rheumatoid arthritis (RA) disease are limited. This work aims to identify the expression pattern of circRNAs in synovial tissues and their inflammatory regulation mechanism. Methods. We first compared the mRNA expression in rheumatoid arthritis patients with that in healthy volunteers by GEO database mining to identify gene loci specifically expressed in synovial tissues. Functional enrichment algorithms were then used to draw the interactome diagram of circRNAs-miRNAs-mRNAs. Finally, loss-of-function and rescue assays of the candidate circRNAs were performed in vitro. Results. A total of 29 differentially expressed circRNAs related to rheumatoid arthritis were discovered. Silencing of hsa_circ_0001859 suppressed ATF2 expression and decreased inflammatory activity in SW982 cells. Hsa_circ_0001859 could compete with ATF2 for miR-204/211. Discussion. These findings indicate that hsa_circ_0001859 participates deeply in the process of chronic inflammatory disease in synovial tissue.

scholarly journals NETs and oncologic process

2021 ◽  
Vol 15 (1) ◽  
pp. 107-116
Author(s):  
E. V. Slukhanchuk
Keyword(s):  
Rheumatoid Arthritis ◽  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Neutrophil Extracellular Traps ◽  
Therapeutic Strategies ◽  
Innate Immune ◽  
Systemic Lupus ◽  
Extracellular Traps ◽  
Activated Neutrophils ◽  
Autoimmune Conditions

Neutrophil Extracellular Traps (NETs) represent the networks consisting of DNA, histones, and proteins produced by activated neutrophils. Such structures have been proved to play a crucial role in inducing neutrophil innate immune response in the pathogenesis of such autoimmune conditions as systemic lupus erythematosus, rheumatoid arthritis, psoriasis, as well as in the pathogenesis of other non-infectious processes, e. g., clotting disorders, thrombosis, diabetes, atherosclerosis, vasculitis and oncology diseases. Recent studies on animal models and human pathologies have uncovered a tremendous role for NETs in tumor progression and metastasis. In this regard, NETs should be considered as pro-oncogenic substances, which further investigation will provide an opportunity to develop new therapeutic strategies.

scholarly journals Anti-Rheumatoid Arthritic Effects of Paris Saponin VII in Human Rheumatoid Arthritis Fibroblast-Like Synoviocytes and Adjuvant-Induced Arthritis in Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Mei Meng ◽  
Zhenggang Yue ◽  
Lu Chang ◽  
Yanru Liu ◽  
Jinhang Hu ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
P38 Mapk ◽  
Ankle Joint ◽  
Adjuvant Induced Arthritis ◽  
Mapk Pathways ◽  
Tnf Α ◽  
Apoptosis Proteins ◽  
Fibroblast Like Synoviocytes

In the pathogenesis of rheumatoid arthritis (RA), rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) have tumor-like characteristics, mainly manifested by hyperproliferation and resistance to apoptosis and then it will erode the bone and cartilage, eventually leading to joint destruction. Paris saponin VII (PS VII) is an active compound derived from a traditional herbal medicine named Trillium tschonoskii Maxim, which has anti-tumor, analgesic, and immunomodulatory effects. However, its anti-RA effect has not yet been reported. This study was to investigate the effect of PS VII on two rheumatoid arthritis fibroblast-like synoviocytes lines (RA-FLS and MH7A) and adjuvant-induced arthritis (AIA) in rats. In vitro, the effects of PS VII on the proliferation, cell cycle, and apoptosis of RA-FLS and MH7A cells were detected by MTT, flow cytometry, and western blot analysis. In vivo, the effect of PS VII on the weight of the rat, paw swelling, ankle joint diameter, arthritis index, serum inflammatory cytokines (TNF-α, IL-6, and IL-1β), histopathological assessment and apoptosis proteins in the synovial tissues were evaluated in AIA rats. The in vitro studies showed that PS VII inhibited the proliferation of RA-FLS and MH7A cells, induced S phase arrest and triggered cell apoptosis mainly through the mitochondrial apoptotic pathway and the regulation of JNK and p38 MAPK pathways. The in vivo studies revealed that PS VII could improve ameliorate body weight, paw swelling, ankle joint diameter, reduce the spleen and thymus index, suppress the production of TNF-α, IL-6 and IL-1β, improve histopathological changes and regulate the expressions of apoptosis proteins in AIA Rats. In conclusion, PS VII could inhibit the proliferation and trigger apoptosis of RA-FLS and MH7A cells by regulating the mitochondrial apoptosis pathway and the JNK and p38 MAPK pathways, and alleviate the symptoms of RA, signifying it to be one of the potential anti-RA therapeutics.

scholarly journals S100A11 (calgizzarin) is released via NETosis in rheumatoid arthritis (RA) and stimulates IL-6 and TNF secretion by neutrophils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adéla Navrátilová ◽  
Viktor Bečvář ◽  
Jiří Baloun ◽  
Dres Damgaard ◽  
Claus Henrik Nielsen ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Synovial Tissue ◽  
Neutrophil Extracellular Traps ◽  
S100 Family ◽  
Extracellular Traps ◽  
Associated Proteins ◽  
First Time ◽  
Pro Inflammatory Cytokines

AbstractS100A11 (calgizzarin), a member of S100 family, is associated with several autoimmune diseases, including rheumatoid arthritis (RA). Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of RA and in the externalization of some S100 family members. Therefore, we aimed to determine the association between S100A11 and NETs in RA. For this purpose, the levels of S100A11 and NETosis markers were detected in the RA synovial fluid by immunoassays. The expression of S100A11 by neutrophils in the RA synovial tissue was assessed. Neutrophils isolated from peripheral blood were exposed to S100A11 or stimulated to release NETs. The levels of NETosis- and inflammation-associated proteins were analysed by immunoassays. NETs were visualized by immunofluorescence. We showed that S100A11 was expressed by the neutrophils in the RA synovial tissue. Moreover, S100A11 in the RA synovial fluid correlated with several NETosis markers. In vitro, S100A11 was abundantly released by neutrophils undergoing NETosis compared to untreated cells (p < 0.001). Extracellular S100A11 increased the secretion of IL-6 (p < 0.05) and TNF (p < 0.05) by neutrophils but did not induce NETosis. This study demonstrates, for the first time, that the release of S100A11 is dependent on NETosis and that extracellular S100A11 augments the inflammatory response by inducing pro-inflammatory cytokines in neutrophils.

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