Zearalenone Induces Estrogen-Receptor-Independent Neutrophil Extracellular Trap Release in Vitro

Abstract Background: There is little knowledge, whether in patients with sepsis neutrophil extracellular trap (NET) formation and NET degrading nuclease activity are altered. Thus, we tested the hypotheses that 1) NET formation from neutrophils of septic patients is increased compared to healthy volunteers, both without stimulation and following incubation with mitochondrial DNA (mtDNA), a damage-associated molecular pattern, or phorbol 12-myristate 13-acetate (PMA; positive control); and 2) serum nuclease activities are increased as well. Methods: We included 18 septic patients and 27 volunteers in this prospective observational trial while study was registered retrospectively. Blood was withdrawn and NET formation from neutrophils in vitro was quantified (average percentage of neutrophils showing NET formation on an image) without stimulation and following incubation with mtDNA (10µg/well) or PMA (25nmol). Serum nuclease activity was assessed using gel electrophoresis. Results: In contrast to our hypothesis, compared to healthy volunteers unstimulated NET release from neutrophils in septic patients was decreased by 46.3% (4.3%±1.8 SD vs. 8.2%±2.9, p≤0.0001) and 48.1% (4.9%±2.5 vs. 9.4%±5.2, p=0.002) after 2 and 4 hours of incubation. mtDNA further decreased NET formation in neutrophils from septic patients (4.7%±1.2 to 2.8%±0,8; p=0.03) but did not alter NET formation in neutrophils from volun-teers. As expected, PMA, as positive control, increased NET formation to 73.2% (±29.6) in septic patients and to 91.7% (±7.1) in volunteers after 4 hours of incubation (p=0.22). Serum nuclease activity (range: 0-6) was decreased in septic patients by 39.6% (3±2 vs 5±0; median and ICR, p=0.0001) compared to volunteers. Conclusions: Unstimulated NET formation and nuclease activity are decreased in septic patients and mtDNA can further reduce NET formation. Thus, neutrophils from septic patients show decreased NET formation in vitro despite diminished nuclease activity in vivo. Trail registration DRKS00007694, German Clinical Trials database (DRKS). Registered retrospectively 06.02.2015.

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TcpC inhibits neutrophil extracellular trap formation by enhancing ubiquitination mediated degradation of peptidylarginine deiminase 4

Nature Communications ◽

10.1038/s41467-021-23881-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Qian Ou ◽

Jia-qi Fang ◽

Zhe-sheng Zhang ◽

Zhe Chi ◽

Jie Fang ◽

...

Keyword(s):

Innate Immune ◽

Neutrophil Extracellular Trap ◽

Mrna Levels ◽

Peptidylarginine Deiminase ◽

E Coli ◽

Peptidylarginine Deiminase 4 ◽

Trap Formation ◽

Extracellular Trap ◽

Innate Immune Evasion

AbstractTcpC is a multifunctional virulence factor of uropathogenic E. coli (UPEC). Neutrophil extracellular trap formation (NETosis) is a crucial anti-infection mechanism of neutrophils. Here we show the influence of TcpC on NETosis and related mechanisms. We show NETosis in the context of a pyelonephritis mouse model induced by TcpC-secreting wild-type E. coli CFT073 (CFT073wt) and LPS-induced in vitro NETosis with CFT073wt or recombinant TcpC (rTcpC)-treated neutrophils are inhibited. rTcpC enters neutrophils through caveolin-mediated endocytosis and inhibits LPS-induced production of ROS, proinflammatory cytokines and protein but not mRNA levels of peptidylarginine deiminase 4 (PAD4). rTcpC treatment enhances PAD4 ubiquitination and accumulation in proteasomes. Moreover, in vitro ubiquitination kit analyses show that TcpC is a PAD4-targetd E3 ubiquitin-ligase. These data suggest that TcpC inhibits NETosis primarily by serving as an E3 ligase that promotes degradation of PAD4. Our findings provide a novel mechanism underlying TcpC-mediated innate immune evasion.

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Uremic serum damages endothelium by provoking excessive neutrophil extracellular trap formation

Scientific Reports ◽

10.1038/s41598-021-00863-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hoi Woul Lee ◽

Victor Nizet ◽

Jung Nam An ◽

Hyung Seok Lee ◽

Young Rim Song ◽

...

Keyword(s):

Inflammatory Responses ◽

Umbilical Vein ◽

Composite Endpoint ◽

Neutrophil Extracellular Trap ◽

Intracellular Adhesion Molecule ◽

Uremic Serum ◽

Control Serum ◽

Extracellular Trap

AbstractCardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD). Endothelial cell (EC) dysfunction is a key CKD-specific risk factor; however, the mechanisms by which uremia harms the endothelium are still unclear. We report a role for excessive neutrophil extracellular trap (NET) formation induced by uremic serum on EC injury. Level of plasma nucleosome and myeloperoxidase-DNA, established in vivo markers of NETs, as well as intracellular adhesion molecule (ICAM)-1 were measured in hemodialysis (HD) patients and healthy volunteers (HV) and their prognostic role evaluated. For in vitro studies, HV-derived neutrophils and differentiated HL-60 cells by retinoic acid were used to determine the effect of uremic serum-induced NETs on human umbilical vein EC (HUVEC). The level of in vivo NETs was significantly higher in incident HD patients compared to HV, and these markers were strongly associated with ICAM-1. Specifically, nucleosome and ICAM-1 levels were independent predictors of a composite endpoint, all-cause mortality, or vascular access failure. In vitro, HD-derived uremic serum significantly increased NET formation both in dHL-60 and isolated neutrophils compared to control serum, and these NETs decreased EC viability and induced their apoptosis. In addition, the level of ICAM-1, E-selectin and von Willebrand factor in HUVEC supernatant was significantly increased by uremic serum-induced NETs compared to control serum-induced NETs. Dysregulated neutrophil activities in the uremic milieu may play a key role in vascular inflammatory responses. The high mortality and CVD rates in ESRD may be explained in part by excessive NET formation leading to EC damage and dysfunction.

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Unmetabolized quetiapine exerts an in vitro effect on innate immune cells by modulating inflammatory response and neutrophil extracellular trap formation

Biomedicine & Pharmacotherapy ◽

10.1016/j.biopha.2020.110497 ◽

2020 ◽

Vol 131 ◽

pp. 110497

Author(s):

Bárbara Osmarin Turra ◽

Fernanda Barbisan ◽

Verônica Farina Azzolin ◽

Cibele Ferreira Teixeira ◽

Thamara Flores ◽

...

Keyword(s):

Inflammatory Response ◽

Immune Cells ◽

Innate Immune ◽

Neutrophil Extracellular Trap ◽

Innate Immune Cells ◽

Trap Formation ◽

Extracellular Trap ◽

Vitro Effect

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Cannabidiol Modifies the Formation of NETs in Neutrophils of Psoriatic Patients

International Journal of Molecular Sciences ◽

10.3390/ijms21186795 ◽

2020 ◽

Vol 21 (18) ◽

pp. 6795

Author(s):

Piotr Wójcik ◽

Marzena Garley ◽

Adam Wroński ◽

Ewa Jabłońska ◽

Elżbieta Skrzydlewska

Keyword(s):

Healthy Subjects ◽

Antioxidant Properties ◽

Neutrophil Extracellular Trap ◽

Oxygen Species ◽

Extracellular Trap ◽

Positive Effect ◽

Healthy Participants ◽

Lps Treatment

Psoriasis is associated with increased production of reactive oxygen species which leads to oxidative stress. As antioxidants can provide protection, the aim of this study was to evaluate the effects of cannabidiol (CBD) on neutrophil extracellular trap (NET) formation in psoriatic and healthy neutrophils. Important markers of NETosis were measured in healthy and psoriatic neutrophils after incubation with CBD, lipopolysaccharide (LPS), and LPS + CBD). The percentage of neutrophils undergoing NETosis and the level of NETosis markers (cfDNA, MPO, elastase) were higher in the neutrophils and blood plasma of psoriatic patients, compared to controls. After LPS treatment, all of the markers of NETosis, except elastase, and p47 and citrullinated histones, were increased in samples from healthy subjects and psoriasis patients. CBD reduced the concentrations of NETosis markers. This led to a reduction in NETosis, which was more pronounced in psoriatic neutrophils and neutrophils treated with LPS in both psoriatic and healthy participants. These results suggest that psoriatic patients neutrophils are at a higher risk of NETosis both in vitro and in vivo. CBD reduces NETosis, mainly in psoriatic neutrophils, possibly due to its antioxidant properties. The anti-NET properties of CBD suggest the positive effect of CBD in the treatment of autoimmune diseases.

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