scholarly journals Melatonin Attenuates Sepsis-Induced Acute Lung Injury Through Improvement of Epithelial Sodium Channel-Mediated Alveolar Fluid Clearance Via Activation of SIRT1/SGK1/Nedd4-2 Signaling Pathway

2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Li ◽  
Longfei Liu ◽  
Xiaojun Zhou ◽  
Xianzhou Lu ◽  
Xianrong Liu ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Sodium Channel ◽  
Signaling Pathway ◽  
Cecal Ligation ◽  
Weight Ratio ◽  
Epithelial Sodium Channel ◽  
Enzyme Linked Immunosorbent Assay ◽  
Alveolar Fluid Clearance ◽  
Protein Expressions

Acute lung injury is characterized by alveolar vascular barrier injury, and protein-rich pulmonary oedema. Alveolar fluid clearance is closely related to the prognosis of patients with acute lung injury. Melatonin has been shown to have a protective effect on multiple organ injury induced by sepsis. In this study we investigated the effect of melatonin on alveolar fluid clearance (AFC) and explored its potential mechanisms in sepsis-induced acute lung injury. The cecal ligation and puncture was adopted to establish mouse sepsis model. Morphological changes of lung tissues with the hematoxylin staining were observed. AFC and lung wet/dry weight ratio were measured to assess pulmonary edema. Inflammatory mediators in bronchoalveolar lavage fluid were analyzed via enzyme-linked immunosorbent assay. NAD+/NADH and SIRT1 activity were measured by colorimetric assay kit. The protein expressions of epithelial sodium channel (ENaC), silent information regulator1 (SIRT1), SGK1 and Nedd4-2 were immunoblotted by western blot in vivo and in vitro. The distribution of α-ENaC and SIRT1 was detected by immunofluorescence. We found that melatonin attenuated sepsis induced lung injury, improved survival rate, enhanced alveolar fluid clearance, improved SIRT1 activity, increased protein expressions of SIRT1 and ENaC, and activated SGK1/Nedd4-2 pathway. Furthermore, SIRT1 inhibitor EX527 counteracted the effects of melatonin on alveolar fluid clearance and ENaC. These results revealed that melatonin enhanced ENaC-mediated AFC via the SIRT1/SGK1/Nedd4-2 signaling pathway. Our study demonstrated that melatonin might provide a novel therapeutic strategy for sepsis-induced acute lung injury.

Dexmedetomidine alleviates pulmonary edema through epithelial sodium channel (ENaC) via the PI3K/Akt/Nedd4-2 pathway in LPS- induced acute lung injury

2020 ◽  
Author(s):  
Yuanxu Jiang ◽  
jing Xu ◽  
Qiang Huang ◽  
Wenjie Yang ◽  
Mingzhu Xia ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Sodium Channel ◽  
Pulmonary Edema ◽  
Signaling Pathway ◽  
Cell Injury ◽  
Epithelial Sodium Channel ◽  
Alveolar Epithelial ◽  
Epithelial Sodium Channel Enac

Abstract Background: Pulmonary edema is a hallmark in acute lung injury(ALI). Researchers have also revealed that dexmedetomidine (Dex) alleviate pulmonary edema following ALI, but the mechanism is unclear.The alveolar epithelial sodium channel (ENaC)-mediated alveolar fluid clearance (AFC) plays an important role in reducing pulmonary edema. In this study, we attempted to investigate the effect of Dex on ENaC in modulating AFC and its mechanism. Methods: LipopolysacchAride (LPS) was used to induce ALI in rat and alveolar epithelial cell injury in A549 cell. The rats were randomly allotted into the following groups: control, LPS, LPS+Dex, LPS+Dex+LY294002 (n = 6 per group). In vitro, cells (1×10 6 cells/cm 2 ) were subcultured in six-well plates, then cells were allotted into the following groups: control, LPS, LPS+Dex, LPS+Dex+LY294002. Results: In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC.Moreover, Dex prevented LPS-induced downregulation of α-, β- and γ-ENaC expression. In A549 cells stimulated with LPS, Dex attanuated LPS-mediated cell injury and the downregulation of α-, β- and γ-ENaC expression. Howere, all of which was blocked by PI3K inhibitor LY294002,suggesting that the protective role of Dex is PI3K dependent. Additionaly, Dex increases the expression of phosphorylated Akt and reduces the expression of Need4-2 in vivo and vitro, while the LY294002 reverses the effect of Dex, indicating that Dex activates the PI3K/Akt/Nedd4-2 signaling pathway. C onclusio ns: Dex alleviates pulmonary edema by promoting AFC, and the mechanism is partly related to up-regulation of ENaC expression via PI3K/Akt/Nedd4-2 signaling pathway.

Inactivation of Nf-κb Pathway by Taxifolin Attenuates Sepsis-Induced Acute Lung Injury

2019 ◽  
Vol 18 (2) ◽  
pp. 176-182
Author(s):  
Chen Weiyan ◽  
Deng Wujian ◽  
Chen Songwei
Keyword(s):  
Acute Lung Injury ◽  
B Cells ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Light Chain ◽  
Cecal Ligation ◽  
Nuclear Factor ◽  
Kappa Light Chain ◽  
Cecal Ligation And Puncture ◽  
Light Chain Enhancer

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.

scholarly journals Plasma extracellular vesicle delivery of miR-210-3p by targeting ATG7 to promote sepsis-induced acute lung injury by regulating autophagy and activating inflammation

2021 ◽  
Author(s):  
Guang Li ◽  
Bo Wang ◽  
Xiangchao Ding ◽  
Xinghua Zhang ◽  
Jian Tang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Recipient Cell ◽  
Cecal Ligation ◽  
Cell Permeability ◽  
Cell Counting ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vascular Density

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.

scholarly journals EGCG promotes PRKCA expression to alleviate LPS-induced acute lung injury and inflammatory response

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mian Wang ◽  
Hua Zhong ◽  
Xian Zhang ◽  
Xin Huang ◽  
Jing Wang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Weight Ratio ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Protective Mechanism ◽  
High Morbidity ◽  
Inflammatory Factor ◽  
Egcg Treatment

AbstractAcute lung injury (ALI), which could be induced by multiple factors such as lipopolysaccharide (LPS), refer to clinical symptoms of acute respiratory failure, commonly with high morbidity and mortality. Reportedly, active ingredients from green tea have anti-inflammatory and anticancer properties, including epigallocatechin-3-gallate (EGCG). In the present study, protein kinase C alpha (PRKCA) is involved in EGCG protection against LPS-induced inflammation and ALI. EGCG treatment attenuated LPS-stimulated ALI in mice as manifested as improved lung injury scores, decreased total cell amounts, neutrophil amounts and macrophage amounts, inhibited the activity of MPO, decreased wet-to-dry weight ratio of lung tissues, and inhibited release of inflammatory cytokines TNF-α, IL-1β, and IL-6. PRKCA mRNA and protein expression showed to be dramatically decreased by LPS treatment while reversed by EGCG treatment. Within LPS-stimulated ALI mice, PRKCA silencing further aggravated, while PRKCA overexpression attenuated LPS-stimulated inflammation and ALI through MAPK signaling pathway. PRKCA silencing attenuated EGCG protection. Within LPS-induced RAW 264.7 macrophages, EGCG could induce PRKCA expression. Single EGCG treatment or Lv-PRKCA infection attenuated LPS-induced increases in inflammatory factors; PRKCA silencing could reverse the suppressive effects of EGCG upon LPS-stimulated inflammatory factor release. In conclusion, EGCG pretreatment inhibits LPS-induced ALI in mice. The protective mechanism might be associated with the inhibitory effects of PRKCA on proinflammatory cytokine release via macrophages and MAPK signaling pathway.

YiQiFuMai Lyophilized Injection Attenuates Sepsis-Induced Acute Lung Injury via TLR4/Src/VE-cadherin/p120-catenin Signaling Pathway

2020 ◽  
Author(s):  
Xue-wei Pan ◽  
Li-xuan Xue ◽  
Qian-liu Zhou ◽  
Jia-zhi Zhang ◽  
Yu-jie Dai ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Therapeutic Potential ◽  
Cecal Ligation ◽  
Inflammatory Cells ◽  
Underlying Mechanism ◽  
Lavage Fluid ◽  
Lung Edema ◽  
P120 Catenin

Abstract Background: Sepsis is a severe disorder leading to a clinically critical syndrome of multiple organ dysfunction syndrome. Most patients with sepsis will be associated with acute lung injury (ALI), which is an independent risk factors of organ failure and death in patients with sepsis at the same time. YiQiFuMai Lyophilized Injection (YQFM) is a modern traditional Chinese prescription preparation, which could ameliorate ALI induced by lipopolysaccharide (LPS) or fine particulate matter. The current study aimed to investigate the effect of YQFM on sepsis-induced ALI and the underlying mechanism.Methods: Male C57BL/6J mice were treated with cecal ligation and puncture (CLP) after tail intravenous injected with YQFM (1, 2 and 4 g/kg). The measurements of lung edema, evans blue leakage, myeloperoxidase content, inflammatory cells in bronchoalveolar lavage fluid, histopathological assay and expression of associated proteins were performed at 18 h after CLP.Results: The results illustrated that YQFM inhibited pulmonary edema and inflammatory response, thus ameliorated ALI in sepsis mice. Furthermore, the expression of TLR4 and phosphorylated Src was down-regulated, and the expression of p120-catenin and VE-cadherin was restored by YQFM administration.Conclusion: Our study suggested the therapeutic potential of YQFM on treating sepsis-induced ALI via regulating TLR4/Src/VE-cadherin/p120-catenin signaling pathway.

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