Dataset Information

Neutrophil extracellular traps (NETs) exacerbate severity of infant sepsis.

ABSTRACT:

Background

Neutrophil extracellular traps (NETs) are innate defense mechanisms that are also implicated in the pathogenesis of organ dysfunction. However, the role of NETs in pediatric sepsis is unknown.

Methods

Infant (2 weeks old) and adult (6 weeks old) mice were submitted to sepsis by intraperitoneal (i.p.) injection of bacteria suspension or lipopolysaccharide (LPS). Neutrophil infiltration, bacteremia, organ injury, and concentrations of cytokine, NETs, and DNase in the plasma were measured. Production of reactive oxygen and nitrogen species and release of NETs by neutrophils were also evaluated. To investigate the functional role of NETs, mice undergoing sepsis were treated with antibiotic plus rhDNase and the survival, organ injury, and levels of inflammatory markers and NETs were determined. Blood samples from pediatric and adult sepsis patients were collected and the concentrations of NETs measured.

Results

Infant C57BL/6 mice subjected to sepsis or LPS-induced endotoxemia produced significantly higher levels of NETs than the adult mice. Moreover, compared to that of the adult mice, this outcome was accompanied by increased organ injury and production of inflammatory cytokines. The increased NETs were associated with elevated expression of Padi4 and histone H3 citrullination in the neutrophils. Furthermore, treatment of infant septic mice with rhDNase or a PAD-4 inhibitor markedly attenuated sepsis. Importantly, pediatric septic patients had high levels of NETs, and the severity of pediatric sepsis was positively correlated with the level of NETs.

Conclusion

This study reveals a hitherto unrecognized mechanism of pediatric sepsis susceptibility and suggests that NETs represents a potential target to improve clinical outcomes of sepsis.

SUBMITTER: Colon DF

PROVIDER: S-EPMC6454713 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Neutrophil extracellular traps (NETs) exacerbate severity of infant sepsis.

Colón David F DF Wanderley Carlos W CW Franchin Marcelo M Silva Camila M CM Hiroki Carlos H CH Castanheira Fernanda V S FVS Donate Paula B PB Lopes Alexandre H AH Volpon Leila C LC Kavaguti Silvia K SK Borges Vanessa F VF Speck-Hernandez Cesar A CA Ramalho Fernando F Carlotti Ana P AP Carmona Fabio F Alves-Filho Jose C JC Liew Foo Y FY Cunha Fernando Q FQ

Critical care (London, England) 20190408 1

<h4>Background</h4>Neutrophil extracellular traps (NETs) are innate defense mechanisms that are also implicated in the pathogenesis of organ dysfunction. However, the role of NETs in pediatric sepsis is unknown.<h4>Methods</h4>Infant (2 weeks old) and adult (6 weeks old) mice were submitted to sepsis by intraperitoneal (i.p.) injection of bacteria suspension or lipopolysaccharide (LPS). Neutrophil infiltration, bacteremia, organ injury, and concentrations of cytokine, NETs, and DNase in the plas ...[more]

PMID: 30961634

Similar Datasets

Project description:BackgroundNeutrophil extracellular trap (NET) formation has been implicated as a pathogenic mechanism in both rheumatoid arthritis (RA) and interstitial lung disease (ILD). However, the role of NETs in RA-associated ILD (RA-ILD) and the mechanisms driving NET formation remain unclear. This study aimed to assess the involvement of NETs in RA-ILD and elucidate the underlying mechanisms.MethodsSingle-cell sequencing was used to identify changes in the quantity and function of neutrophils in the lung tissue of a zymosan A (ZYM)-induced interstitial pneumonia arthritis model. Additionally, nuclear receptor 4A3 (NR4A3) interference was performed in HL-60 cells to assess its impact on NET formation and the transformation of MRC-5 cells into myofibroblasts. The clinical relevance of plasma myeloperoxidase-DNA (MPO-DNA), citrullinated histone 3 (Cit-H3), and cell-free DNA was evaluated in RA-ILD patients with different imaging types via a commercial enzyme-linked immunosorbent assay (ELISA).ResultsIn the ZYM-treated SKG mouse model, which recapitulates key features of RA-ILD, an increased population of neutrophils in the lung tissue was primarily responsible for NET formation. Mechanistically, we found that interference with NR4A3 expression enhanced NET formation in HL-60 cells, which in turn promoted the differentiation of MRC-5 cells into myofibroblasts. Clinically, plasma MPO-DNA levels are elevated in patients with RA-nonspecific interstitial pneumonia (RA-NSIP), whereas Cit-H3 levels are elevated in RA-usual interstitial pneumonia (RA-UIP) patients compared with healthy subjects. ROC curve analysis further revealed that the combination of plasma MPO-DNA, rheumatoid factor (RF), and anti-citrullinated protein (anti-CCP) and the combination of Cit-H3, RF, and anti-CCP were superior diagnostic panels for NSIP and UIP in RA-ILD patients, respectively. Moreover, compared with those from healthy controls, neutrophils from patients with RA-UIP and RA-NSIP demonstrated a significantly increased ability to form NETs and induce the differentiation of MRC-5 cells into myofibroblasts. Specifically, RA-UIP patients exhibited a greater capacity for NET formation and the differentiation of MRC-5 cells into myofibroblasts than did RA-NSIP patients.ConclusionsThese findings suggest that targeting NETs may be a novel therapeutic approach for treating ILD in RA patients.

Project description:BackgroundTo investigate the effect and mechanism of Celastrol on the formation of neutrophil extracellular traps (NETs), and to provide a theoretical basis for the clinical application of Tripterygium wilfordii.MethodsFirst, we isolated neutrophils from the peripheral blood of healthy volunteers, and then observed the effect of Celastrol on Phorbol Myristate Acetate (PMA)-induced neutrophil release of NETs. The level of NETs was detected by using the membrane-impermeable nucleic acid dye, SytoxGreens. In addition, the levels of reactive oxygen species (ROS) were also examined to determine whether Celastrol affects ROS production during PMA-induced NETs.ResultsCelastrol produced significant cytotoxicity at a concentration of 5 µM (213.2±75.07), and the effect of stimulant PMA (25 nM) treatment was not statistically different (197.3±25.15) (P=0.9167). Celastrol (1.25, 0.625, and 0.3125 µM) did not exhibit cytotoxicity when treating neutrophils. Compared with the PMA (25 nM) + Celastrol (1.25, 0.625, and 0.3125 µM) group and the PMA (25 nM) monotherapy group, SytoxGreen showed a statistically significant reduction in fluorescence at 528 µM under 485 µM light excitation. Also, under the co-localization marker of Hochest and SytoxGreen double staining, we observed that the release of NETs in the PMA-treated group was higher than that in the control group. The PMA-induced neutrophil release of NETs was markedly reduced compared to the PMA-treated group. The NET release was substantially decreased under double staining with the Hochest and SytoxGreen co-localization markers. The fluorescence intensity of the Celastrol plus PMA group was significantly lower than that of the PMA treatment group alone, indicating a decrease in the level of intracellular ROS. Interestingly, the level of ROS in the treatment group who received Celastrol alone was lower than that in the control group, indicating that Tripterygium wilfordii could inhibit the spontaneous production of ROS by neutrophils in the absence of stimulation.ConclusionsThe molecular mechanism of Celastrol involves inhibition of PMA-stimulated neutrophil NETs formation in vitro, which is possibly related to the reduction of ROS levels. This indicates that Celastrol, the main component in Tripterygium wilfordii, can inhibit the formation of NETs, which provides a theoretical basis for the study of NETs-related diseases.

Dataset Information

Neutrophil extracellular traps (NETs) exacerbate severity of infant sepsis.

Background

Methods

Results

Conclusion

Publications

Neutrophil extracellular traps (NETs) exacerbate severity of infant sepsis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets