scholarly journals Activated Platelets Autocrine 5-Hydroxytryptophan Aggravates Sepsis-Induced Acute Lung Injury by Promoting Neutrophils Extracellular Traps Formation

Yumeng Huang ◽  
Qian Ji ◽  
Yanyan Zhu ◽  
Shengqiao Fu ◽  
Shuangwei Chen ◽  

Excessive neutrophil extracellular trap (NET) formation is an important contributor to sepsis-induced acute lung injury (ALI). Recent reports indicate that platelets can induce neutrophil extracellular trap formation. However, the specific mechanism remains unclear. Tph1 gene, which encodes the rate-limiting enzyme for peripheral 5-hydroxytryptophan (5-HT) synthesis, was knocked out in mice to simulate peripheral 5-HT deficiency. Cecal ligation and puncture (CLP) surgery was performed to induce sepsis. We found that peripheral 5-HT deficiency reduced NET formation in lung tissues, alleviated sepsis-induced lung inflammatory injury, and reduced the mortality rate of CLP mice. In addition, peripheral 5-HT deficiency was shown to reduce the accumulation of platelets and NETs in the lung of septic mice. We found that platelets from wild-type (WT), but not Tph1 knockout (Tph1−/−), mice promote lipopolysaccharide (LPS)-induced NET formation. Exogenous 5-HT intervention increased LPS-induced NET formation when Tph1−/− platelets were co-cultured with WT neutrophils. Therefore, our study uncovers a mechanism by which peripheral 5-HT aggravated sepsis-induced ALI by promoting NET formation in the lung of septic mice.

Mona Saffarzadeh ◽  
Markus A. Queisser ◽  
Christiane Jünemann ◽  
Klaus T. Preissner

2014 ◽  
Vol 192 (10) ◽  
pp. 4795-4803 ◽  
Shaoning Jiang ◽  
Dae Won Park ◽  
Jean-Marc Tadie ◽  
Murielle Gregoire ◽  
Jessy Deshane ◽  

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. SCI-18-SCI-18 ◽  
Mark R. Looney

Abstract Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality in the U.S. and a major cause of transfusion-associated morbidity including increased time on mechanical ventilation and length of stay in the intensive care unit and the hospital. Neutrophils have been identified as critical cellular mediators in the pathogenesis of TRALI in both clinical studies and in experimental settings using a variety of injury models. Platelets have been implicated as a blood product that can trigger TRALI, and endogenous platelet activation contributes to lung injury. Platelets bind to the surface of neutrophils to form heterotypic aggregates, and activated platelets can trigger the formation of neutrophil extracellular traps (NETs), which is a new mode of neutrophil death that is distinct from apoptosis and necrosis. NETs are produced in experimental TRALI and are increased in post-transfusion plasma from patients who develop TRALI. Blocking platelet activation reduces the production of NETs and lung injury, and inhibiting NETs by blocking extracellular histones or dismantling the NET structure with DNase1 are strongly protective in TRALI. In conclusion, TRALI is an immune-mediated event in which activated platelets, neutrophils, and NETs, contribute to injury and are therefore targets for therapeutic intervention. Disclosures No relevant conflicts of interest to declare.

Avin Hawez ◽  
Zhiyi Ding ◽  
Dler Taha ◽  
Raed Madhi ◽  
Milladur Rahman ◽  

AbstractSepsis is associated with exaggerated neutrophil responses although mechanisms remain elusive. The aim of this study was to investigate the role of c-Abelson (c-Abl) kinase in neutrophil extracellular trap (NET) formation and inflammation in septic lung injury. Abdominal sepsis was induced by cecal ligation and puncture (CLP). NETs were detected by electron microscopy in the lung and by confocal microscopy in vitro. Plasma levels of DNA-histone complexes, interleukin-6 (IL-6) and CXC chemokines were quantified. CLP-induced enhanced phosphorylation of c-Abl kinase in circulating neutrophils. Administration of the c-Abl kinase inhibitor GZD824 not only abolished activation of c-Abl kinase in neutrophils but also reduced NET formation in the lung and plasma levels of DNA-histone complexes in CLP mice. Moreover, inhibition of c-Abl kinase decreased CLP-induced lung edema and injury. Administration of GDZ824 reduced CLP-induced increases in the number of alveolar neutrophils. Inhibition of c-Abl kinase also markedly attenuated levels of CXC chemokines in the lung and plasma as well as IL-6 levels in the plasma of septic animals. Taken together, this study demonstrates that c-Abl kinase is a potent regulator of NET formation and we conclude that c-Abl kinase might be a useful target to ameliorate lung damage in abdominal sepsis.

2020 ◽  
Vol 18 (2) ◽  
pp. 201-206
Qiu Nan ◽  
Xu Xinmei ◽  
He Yingying ◽  
Fan Chengfen

Sepsis, with high mortality, induces deleterious organ dysfunction and acute lung injury. Natural compounds show protective effect against sepsis-induced acute lung injury. Juglone, a natural naphthoquinone, demonstrates pharmacological actions as a pro-apoptotic substrate in tumor treatment and anti-inflammation substrate in organ injury. In this study, the influence of juglone on sepsis-induced acute lung injury was investigated. First, a septic mice model was established via cecal ligation and puncture, and then verified via histopathological analysis of lung tissues, the wet/dry mass ratio and myeloperoxidase activity was determined. Cecal ligation and puncture could induce acute lung injury in septic mice, as demonstrated by alveolar damage and increase of wet/dry mass ratio and myeloperoxidase activity. However, intragastric administration juglone attenuated cecal ligation and puncture-induced acute lung injury. Secondly, cecal ligation and puncture-induced increase of inflammatory cells in bronchoalveolar lavage fluid was also alleviated by the administration of juglone. Similarly, the protective effect of juglone against cecal ligation and puncture-induced acute lung injury was accompanied by a reduction of pro-inflammatory factor secretion in bronchoalveolar lavage fluid and lung tissues. Cecal ligation and puncture could activate toll-like receptor 4/nuclear factor-kappa B signaling pathway, and administration of juglone suppressed toll-like receptor 4/nuclear factor-kappa B activation. In conclusion, juglone attenuated cecal ligation and puncture-induced lung damage and inflammatory response through inactivation of toll-like receptor 4/nuclear factor-kappa B, suggesting a potential therapeutic strategy in the treatment of sepsis-induced acute lung injury.

2019 ◽  
Vol 18 (2) ◽  
pp. 176-182
Chen Weiyan ◽  
Deng Wujian ◽  
Chen Songwei

Acute lung injury is a clinical syndrome consisting of a wide range of acute hypoxemic respiratory failure disorders. Sepsis is a serious complication caused by an excessive immune response to pathogen-induced infections, which has become a major predisposing factor for acute lung injury. Taxifolin is a natural flavonoid that shows diverse therapeutic benefits in inflammation- and oxidative stress-related diseases. In this study, we investigated the role of taxifolin in a mouse model of cecal ligation and puncture-induced sepsis. Cecal ligation and puncture-operated mice presented damaged alveolar structures, thickened alveolar walls, edematous septa, and hemorrhage compared to sham-treated controls. Cecal ligation and puncture mice also showed increased wet-to-dry (W/D) lung weight ratio and elevated total protein concentration and lactate dehydrogenase level in bronchoalveolar lavage fluid. Taxifolin treatment protected animals against sepsis-induced pulmonary damage and edema. Septic mice presented compromised antioxidant capacity, whereas the administration of taxifolin prior to cecal ligation and puncture surgery decreased malondialdehyde concentration and enhanced the levels of reduced glutathione and superoxide dismutase in mice with sepsis-induced acute lung injury. Moreover, cecal ligation and puncture-operated mice showed markedly higher levels of proinflammatory cytokines relative to sham-operated group, while taxifolin treatment effectively mitigated sepsis-induced inflammation in mouse lungs. Further investigation revealed that taxifolin suppressed the activation of the nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway in cecal ligation and puncture-challenged mice by regulating the phosphorylation of p65 and IκBα. In conclusion, our study showed that taxifolin alleviated sepsis-induced acute lung injury via the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway, suggesting the therapeutic potential of taxifolin in the treatment sepsis-induced acute lung injury.

Guang Li ◽  
Bo Wang ◽  
Xiangchao Ding ◽  
Xinghua Zhang ◽  
Jian Tang ◽  

AbstractExtracellular vesicles (EVs) can be used for intercellular communication by facilitating the transfer of miRNAs from one cell to a recipient cell. MicroRNA (miR)-210-3p is released into the blood during sepsis, inducing cytokine production and promoting leukocyte migration. Thus, the current study aimed to elucidate the role of plasma EVs in delivering miR-210-3p in sepsis-induced acute lung injury (ALI). Plasma EVs were isolated from septic patients, after which the expression of various inflammatory factors was measured using enzyme-linked immunosorbent assay. Cell viability and apoptosis were measured via cell counting kit-8 and flow cytometry. Transendothelial resistance and fluorescein isothiocyanate fluorescence were used to measure endothelial cell permeability. Matrigel was used to examine the tubulogenesis of endothelial cells. The targeting relationship between miR-210-3p and ATG7 was assessed by dual-luciferase reporter assays. The expression of ATG7 and autophagy-related genes was determined to examine autophagic activation. A sepsis mouse model was established by cecal ligation and puncture (CLP)-induced surgery. The level of miR-210-3p was highly enriched in septic EVs. MiR-210-3p enhanced THP-1 macrophage inflammation, BEAS-2B cell apoptosis, and HLMVEC permeability while inhibiting angiogenesis and cellular activity. MiR-210-3p overexpression reduced ATG7 and LC3II/LC3I expression and increased P62 expression. Improvements in vascular density and autophagosome formation, increased ATG7 expression, and changes in the ratio of LC3II/LC3I were detected, as well as reduced P62 expression, in adenovirus-anti-miR-210-3p treated mice after CLP injury. Taken together, the key findings of the current study demonstrate that plasma EVs carrying miR-210-3p target ATG7 to regulate autophagy and inflammatory activation in a sepsis-induced ALI model.

Sign in / Sign up

Export Citation Format

Share Document