scholarly journals Investigation of H2S Donor Treatment on Neutrophil Extracellular Traps in Experimental Colitis

2021 ◽  
Vol 22 (23) ◽  
pp. 12729
Author(s):  
Szilvia Török ◽  
Nikoletta Almási ◽  
Zsuzsanna Valkusz ◽  
Anikó Pósa ◽  
Csaba Varga ◽  
...  
Keyword(s):  
High Mobility ◽  
Experimental Colitis ◽  
Neutrophil Extracellular Traps ◽  
Treated Group ◽  
Arginine Deiminase ◽  
Male Rats ◽  
Trinitrobenzenesulfonic Acid ◽  
Extracellular Traps ◽  
Bowel Diseases ◽  
Anti Inflammatory

Inflammatory bowel diseases (IBD) are chronic, immune-mediated disorders, which affect the gastrointestinal tract with intermittent ulceration. It is increasingly clear that neutrophil extracellular traps (NETs) seem to have a role in IBD; however, the associated pathogenesis is still not known. Furthermore, several conventional therapies are available against IBD, although these might have side effects. Our current study aimed to investigate the effects of hydrogen sulfide (H2S) treatment on NETs formation and on the expression of inflammatory mediators in experimental rat colitis. To model IBD, 2,4,6-trinitrobenzenesulfonic acid (TNBS) was administered intracolonically (i.c.) to Wistar–Harlan male rats. Animals were treated (2 times/day) with H2S donor Lawesson’s reagent per os. Our results showed that H2S treatment significantly decreased the extent of colonic lesions. Furthermore, the expression of members of NETs formation: peptidyl arginine deiminase 4 (PAD4), citrullinated histone H3 (citH3), myeloperoxidase (MPO) and inflammatory regulators, such as nuclear transcription factor-kappa B (NF-κB) and high-mobility group box 1 (HMGB1) were reduced in H2S treated group compared to TNBS. Additionally, H2S donor administration elevated the expression of ubiquitin C-terminal hydroxylase L1 (UCHL-1), a potential anti-inflammatory mediator. Taken together, our results showed that H2S may exert anti-inflammatory effect through the inhibition of NETs formation, which suggests a new therapeutic approach against IBD.

scholarly journals Silver Nanoparticles Induce Neutrophil Extracellular Traps Via Activation of PAD and Neutrophil Elastase

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 317
Author(s):  
HanGoo Kang ◽  
Jinwon Seo ◽  
Eun-Jeong Yang ◽  
In-Hong Choi
Keyword(s):  
Silver Nanoparticles ◽  
Neutrophil Elastase ◽  
Mammalian Cells ◽  
Antimicrobial Properties ◽  
Neutrophil Extracellular Traps ◽  
Arginine Deiminase ◽  
Human Neutrophils ◽  
Extracellular Traps ◽  
Peptidyl Arginine Deiminase ◽  
Key Factor

Silver nanoparticles (AgNPs) are widely used in various fields because of their antimicrobial properties. However, many studies have reported that AgNPs can be harmful to both microorganisms and humans. Reactive oxygen species (ROS) are a key factor of cytotoxicity of AgNPs in mammalian cells and an important factor in the immune reaction of neutrophils. The immune reactions of neutrophils include the expulsion of webs of DNA surrounded by histones and granular proteins. These webs of DNA are termed neutrophil extracellular traps (NETs). NETs allow neutrophils to catch and destroy pathogens in extracellular spaces. In this study, we investigated how AgNPs stimulate neutrophils, specifically focusing on NETs. Freshly isolated human neutrophils were treated with 5 or 100 nm AgNPs. The 5 nm AgNPs induced NET formation, but the 100 nm AgNPs did not. Subsequently, we investigated the mechanism of AgNP-induced NETs using known inhibitors related to NET formation. AgNP-induced NETs were dependent on ROS, peptidyl arginine deiminase, and neutrophil elastase. The result in this study indicates that treatment of 5 nm AgNPs induce NET formation through histone citrullination by peptidyl arginine deiminase and histone cleavage by neutrophil elastase.

Expression and secretion of lipocortin 1 in gut inflammation are not regulated by pituitary-adrenal axis

1997 ◽  
Vol 273 (2) ◽  
pp. R623-R629 ◽  
Author(s):  
N. Vergnolle ◽  
C. Comera ◽  
J. More ◽  
M. Alvinerie ◽  
L. Bueno
Keyword(s):  
Culture Medium ◽  
Experimental Colitis ◽  
Myeloperoxidase Activity ◽  
Trinitrobenzenesulfonic Acid ◽  
Gut Inflammation ◽  
Adrenal Axis ◽  
Histological Damage ◽  
Anti Inflammatory ◽  
Pituitary Adrenal Axis

Lipocortin 1 is considered a mediator of the anti-inflammatory actions of glucocorticoids. We have shown that this protein is overexpressed and secreted during an experimental colitis induced by intraluminal injection of trinitrobenzenesulfonic acid (TNBS) in rats. We studied here the in vivo regulation of lipocortin 1 expression and secretion in this model, either by glucocorticoids using adrenalectomized or dexamethasone-treated (3 mg/24 h) animals or by pituitary factors using hypophysectomized animals. Inflammation was evaluated by measuring myeloperoxidase activity and by histological scoring of the damage. Lipocortin 1 was detected by immunoblotting, and its secretion was studied by incubating colonic specimens in-culture medium. In the colon of TNBS-injected animals, cumulative histological damage scores were increased in adrenalectomized and decreased in dexamethasone-treated animals compared with control and hypophysectomized animals. The colons of all TNBS-injected animals (controls, adrenalectomized, dexamethasone treated, hypophysectomized) overexpressed and secreted lipocortin 1. In conclusion, the induction of lipocortin 1 overexpression and secretion during this colitis occurs independently of glucocorticoids or pituitary factors.

scholarly journals Neutrophil extracellular traps promote scar formation in post-epidural fibrosis

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Zhen Jin ◽  
Jinpeng Sun ◽  
Zeyuan Song ◽  
Kun Chen ◽  
Yap San Min Nicolas ◽  
...  
Keyword(s):  
High Mobility ◽  
Major Complication ◽  
Neutrophil Extracellular Traps ◽  
Scar Formation ◽  
Degraded Dna ◽  
Epidural Fibrosis ◽  
Wound Area ◽  
Extracellular Traps ◽  
Shed Light

Abstract Low back pain following spine surgery is a major complication due to excessive epidural fibrosis, which compresses the lumbar nerve. The mechanisms of epidural fibrosis remain largely elusive. In the drainage samples from patients after spine operation, neutrophil extracellular traps (NETs) and NETs inducer high-mobility group box 1 were significantly increased. In a mouse model of laminectomy, NETs developed in the wound area post epidural operation, accompanied with macrophage infiltration. In vitro, macrophages ingested NETs and thereby increased the elastase from NETs via the receptor for advanced glycation end product. Moreover, NETs boosted the expression of fibronectin in macrophages, which was dependent on elastase and could be partially blocked by DNase. NF-κB p65 and Smad pathways contributed to the increased expression fibronectin in NETs-treated macrophages. In the mouse spine operation model, post-epidural fibrosis was significantly mitigated with the administration of DNase I, which degraded DNA and cleaved NETs. Our study shed light on the roles and mechanisms of NETs in the scar formation post spine operation.

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.

Neutrophil extracellular traps are a source of extracellular HMGB1 in lupus nephritis: associations with clinical and histopathological features

Lupus ◽  
2019 ◽  
Vol 28 (13) ◽  
pp. 1549-1557 ◽  
Author(s):  
L P Whittall-García ◽  
J Torres-Ruiz ◽  
A Zentella-Dehesa ◽  
M Tapia-Rodríguez ◽  
J Alcocer-Varela ◽  
...  
Keyword(s):  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Activity Index ◽  
High Mobility ◽  
Disease Activity Index ◽  
Neutrophil Extracellular Traps ◽  
Hmgb1 Protein ◽  
Sledai Score ◽  
Histopathological Features ◽  
Extracellular Traps

Objective This study aimed to analyze the expression of the high mobility group box-1 (HMGB1) protein in neutrophil extracellular traps (NETs) of patients with lupus nephritis (LN) and its association with clinical and histopathological features of the disease. Methods Twenty-three patients with biopsy-confirmed LN and 14 systemic lupus erythematosus (SLE) patients with active disease (SLE Disease Activity Index (SLEDAI) score ≥ 6) and no evidence of LN were included. Clinical and laboratory features were recorded. NETs and the expression of HMGB1 were assessed by confocal microscopy, and serum HMGB1 levels were measured by ELISA. Results In comparison to patients without kidney disease, patients with LN had a higher expression of HMGB1 in spontaneous (57 vs. 30.4; p = 0.027) and lipopolysaccharide (LPS)-induced (55.8 vs. 24.9; p = 0.005) NETs. We found a positive correlation between serum HMGB1 and the expression of HMGB1 in LPS-induced NETs ( r = 0.447, p = 0.017). The expression of HMGB1 in spontaneous NETs correlated with SLEDAI score ( r = 0.514, p = 0.001), anti-dsDNA antibodies ( r = 0.467, p = 0.004), the rate of glomerular filtration descent ( r = 0.543, p = 0.001), and diverse histopathological components of active nephritis in the kidney biopsy, such as the activity index ( r = 0.581, p = 0.004), fibrinoid necrosis ( r = 0.603, p = 0.002), and cellular crescents ( r = 0.486, p = 0.019). Conclusions In patients with SLE, NETs are a source of extracellular HMGB1. The expression of HMGB1 in NETs is higher among patients with LN, which correlates with clinical and histopathological features of active nephritis and suggest a possible role of this alarmin in the pathophysiology of kidney damage in SLE.

scholarly journals Histone citrullination: a new target for tumors

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dongwei Zhu ◽  
Yue Zhang ◽  
Shengjun Wang
Keyword(s):  
Gene Regulation ◽  
Gene Transcription ◽  
Neutrophil Extracellular Traps ◽  
Arginine Deiminase ◽  
Physiological Regulation ◽  
Extracellular Traps ◽  
Main Protein ◽  
Histone Citrullination ◽  
Protein Components ◽  
The Relationship

AbstractAs the main protein components of chromatin, histones play central roles in gene regulation as spools of winding DNA. Histones are subject to various modifications, including phosphorylation, acetylation, glycosylation, methylation, ubiquitination and citrullination, which affect gene transcription. Histone citrullination, a posttranscriptional modification catalyzed by peptidyl arginine deiminase (PAD) enzymes, is involved in human carcinogenesis. In this study, we highlighted the functions of histone citrullination in physiological regulation and tumors. Additionally, because histone citrullination involves forming neutrophil extracellular traps (NETs), the relationship between NETs and tumors was illustrated. Finally, the clinical application of histone citrullination and PAD inhibitors was discussed.

Sign in / Sign up

Export Citation Format

Share Document