scholarly journals Identification of triptolide, a natural diterpenoid compound, as an inhibitor of lung inflammation

2010 ◽  
Vol 298 (6) ◽  
pp. L830-L836 ◽  
Author(s):  
Gary W. Hoyle ◽  
Christine I. Hoyle ◽  
Jing Chen ◽  
Weiyuan Chang ◽  
Ronald W. Williams ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Substance P ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Lung Inflammation ◽  
A549 Cells ◽  
In Vivo Model ◽  
Anti Inflammatory ◽  
Stimulation Of

Inflammation is associated with various pulmonary diseases and contributes to the pathogenesis of acute lung injury. We previously identified a proinflammatory signaling pathway triggered by G protein-coupled receptors (GPCRs) in which stimulation of Gq-coupled GPCRs results in activation of the transcription factor NF-κB. Because damage to the lung causes the release of multiple mediators acting through Gq-coupled GPCRs, this signaling pathway is likely to contribute to inflammatory processes in the injured lung. In an effort to identify novel inhibitors of lung inflammation, the National Institutes of Health Clinical Collection, a library of 446 compounds, was screened for inhibitory activity toward production of IL-8 induced by stimulation of the Gq-coupled tachykinin 1 receptor with substance P in A549 cells. Twenty-eight compounds that significantly inhibited substance P-induced IL-8 production were identified. The most potent inhibitor was triptolide, a diterpenoid compound from Tripterygium wilfordii Hook F, a vine used in traditional Chinese medicine for the treatment of autoimmune diseases. Triptolide inhibited IL-8 production induced by substance P with an IC50 of 2.3 × 10−8 M and inhibited NF-κB activation in response to an agonist of the protease-activated receptor 2 with an IC50 of 1.4 × 10−8 M. Anti-inflammatory effects of triptolide were assessed in vivo using a chlorine gas lung injury model in mice. Triptolide inhibited neutrophilic inflammation and the production of KC (Cxcl1) in the lungs of chlorine-exposed mice. The results demonstrate that triptolide exhibits anti-inflammatory activity in cultured lung cells and in an in vivo model of acute lung injury.

Ulinastatin Activated The ERK5/Mer Signaling Pathway To Promote Macrophage Efferocytosis And Ameliorate Lung Inflammation

2021 ◽  
Author(s):  
Jinju Li ◽  
Rongge Shao ◽  
Qiuwen Xie ◽  
XueKe Du
Keyword(s):  
Lung Injury ◽  
Signaling Pathway ◽  
Lung Inflammation ◽  
Raw264.7 Cells ◽  
Inflammatory Factors ◽  
Inflammatory Factor ◽  
Dependent Manner ◽  
Anti Inflammatory

Abstract Purpose:Ulinastatin (UTI) is an endogenous protease inhibitor with potent anti-inflammatory, antioxidant and organ protective effects. The inhibitor has been reported to ameliorate inflammatory lung injury but precise mechanisms remain unclear. Methods: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). The number of neutrophils and the phagocytosis of apoptotic neutrophils were observed by Diff- Quick method. Lung injury was observed by HE staining .BALF cells were counted by hemocytometer and concentrations of protein plus inflammatory factors were measured with a BCA test kit. During in vitro experiments, RAW264.7 cells were pretreated with UTI (1000 and 5000U/ mL), stained with CellTrackerTM Green B0DIPYTM and HL60 cells added with UV-induced apoptosis and PKH26 Red staining. The expression of ERK5\Mer related proteins was detected by western blot and immunofluorescence.Results: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). UTI treatment enhanced the phagocytotic effect of mouse alveolar macrophages on neutrophils, alleviated lung lesions, decreased the pro-inflammatory factor and total protein content of BALF and increased levels of anti-inflammatory factors. in vitro experiments ，UTI enhanced the phagocytosis of apoptotic bodies by RAW264.7 cells in a dose-dependent manner. Increased expression levels of ERK5 and Mer by UTI were shown by Western blotting and immunofluorescence.Conclusions: UTI mediated the activation of the ERK5/Mer signaling pathway, enhanced phagocytosis of neutrophils by macrophages and improved lung inflammation. The current study indicates potential new clinical approaches for accelerating the recovery from lung inflammation.

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

2021 ◽  
Author(s):  
Yuanxu Jiang ◽  
Mingzhu Xia ◽  
Jing Xu ◽  
Qiang Huang ◽  
Zhongliang Dai ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Sodium Channel ◽  
Pulmonary Edema ◽  
Cell Injury ◽  
A549 Cells ◽  
Alveolar Epithelial ◽  
Phosphorylated Akt ◽  
Epithelial Sodium Channel Enac

AbstractDexmedetomidine (Dex), a highly selective α2-adrenergic receptor (α2AR) agonist, has an anti-inflammatory property and can alleviate pulmonary edema in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the mechanism is still unclear. In this study, we attempted to investigate the effect of Dex on alveolar epithelial sodium channel (ENaC) in the modulation of alveolar fluid clearance (AFC) and the underlying mechanism. Lipopolysaccharide (LPS) was used to induce acute lung injury (ALI) in rats and alveolar epithelial cell injury in A549 cells. In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC, prevented LPS-induced downregulation of α-, β-, and γ-ENaC expression, attenuated inflammatory cell infiltration in lung tissue, reduced the concentrations of TNF-α, IL-1β, and IL-6, and increased concentrations of IL-10 in bronchoalveolar lavage fluid (BALF). In A549 cells stimulated with LPS, Dex attenuated LPS-mediated cell injury and the downregulation of α-, β-, and γ-ENaC expression. However, all of these effects were blocked by the PI3K inhibitor LY294002, suggesting that the protective role of Dex is PI3K-dependent. Additionally, Dex increased the expression of phosphorylated Akt and reduced the expression of Nedd4-2, while LY294002 reversed the effect of Dex in vivo and in vitro. Furthermore, insulin-like growth factor (IGF)-1, a PI3K agonists, promoted the expression of phosphorylated Akt and reduced the expression of Nedd4-2 in LPS-stimulated A549 cells, indicating that Dex worked through PI3K, and Akt and Nedd4-2 are downstream of PI3K. In conclusion, Dex alleviates pulmonary edema by suppressing inflammatory response in LPS-induced ALI, and the mechanism is partly related to the upregulation of ENaC expression via the PI3K/Akt/Nedd4-2 signaling pathway.

scholarly journals Effects of Antibiotic Therapy on Pseudomonas aeruginosa-Induced Lung Injury in a Rat Model

1999 ◽  
Vol 43 (10) ◽  
pp. 2389-2394 ◽  
Author(s):  
Erika J. Ernst ◽  
Satoru Hashimoto ◽  
Joseph Guglielmo ◽  
Teiji Sawa ◽  
Jean-Francois Pittet ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Rat Model ◽  
In Vivo Model ◽  
Antibiotic Administration ◽  
Lung Water ◽  
Alveolar Epithelial ◽  
The Right

ABSTRACT The effect of antibiotics on the acute lung injury induced by virulent Pseudomonas aeruginosa PA103 was quantitatively analyzed in a rat model. Lung injury was induced by the instillation of PA103 directly into the right lower lobes of the lungs of anesthetized rats. The alveolar epithelial injury, extravascular lung water, and total plasma equivalents were measured as separate, independent parameters of acute lung injury. Four hours after the instillation of PA103, all the parameters were increased linearly depending on the dose of P. aeruginosa. Next, we examined the effects of intravenously administered antibiotics on the parameters of acute lung injury in d-galactosamine-sensitized rats. One hour after the rats received 107 CFU of PA103, an intravenous bolus injection of aztreonam (60 mg/kg) or imipenem-cilastatin (30 mg/kg) was administered. Despite an MIC indicating resistance, imipenem-cilastatin improved all the measurements of lung injury; in contrast, aztreonam, which had an MIC indicating sensitivity, did not improve any of the lung injury parameters. The antibiotics did not generate different quantities of plasma endotoxin; therefore, endotoxin did not appear to explain the differences in lung injury. This in vivo model is useful to quantitatively compare the efficacies of parenteral antibiotic administration on Pseudomonas airspace infections.

Vanillin protects lipopolysaccharide-induced acute lung injury by inhibiting ERK1/2, p38 and NF-κB pathway

2019 ◽  
Vol 11 (16) ◽  
pp. 2081-2094 ◽  
Author(s):  
Tingting Guo ◽  
Zhenzhong Su ◽  
Qi Wang ◽  
Wei Hou ◽  
Junyao Li ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Western Blot ◽  
Lung Inflammation ◽  
Macrophage Activation ◽  
Myeloperoxidase Activity ◽  
Histopathological Changes ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Aim: Thus far, the anti-inflammatory effect of vanillin in acute lung injury (ALI) has not been studied. This study aimed to investigate the effect of vanillin in lipopolysaccharide (LPS)-induced ALI. Results & methodology: Our study detected the anti-inflammatory effects of vanillin by ELISA and western blot, respectively. Pretreatment of mice with vanillin significantly attenuated LPS-stimulated lung histopathological changes, myeloperoxidase activity and expression levels of proinflammatory cytokines by inhibiting the phosphorylation activities of ERK1/2, p38, AKT and NF-κB p65. In addition, vanillin inhibited LPS-induced TNF-α and IL-6 expression in RAW264.7 cells via ERK1/2, p38 and NF-κB signaling. Conclusion: Vanillin can inhibit macrophage activation and lung inflammation, which suggests new insights for clinical treatment of ALI.

scholarly journals The Crucial Role of PPARγ-Egr-1-Pro-Inflammatory Mediators Axis in IgG Immune Complex-Induced Acute Lung Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunguang Yan ◽  
Jing Chen ◽  
Yue Ding ◽  
Zetian Zhou ◽  
Bingyu Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Immune Complex ◽  
Inflammatory Mediators ◽  
Lung Inflammation ◽  
Acute Lung Inflammation ◽  
Pparγ Agonist

BackgroundThe ligand-activated transcription factor peroxisome proliferator-activated receptor (PPAR) γ plays crucial roles in diverse biological processes including cellular metabolism, differentiation, development, and immune response. However, during IgG immune complex (IgG-IC)-induced acute lung inflammation, its expression and function in the pulmonary tissue remains unknown.ObjectivesThe study is designed to determine the effect of PPARγ on IgG-IC-triggered acute lung inflammation, and the underlying mechanisms, which might provide theoretical basis for therapy of acute lung inflammation.SettingDepartment of Pathogenic Biology and Immunology, Medical School of Southeast UniversitySubjectsMice with down-regulated/up-regulated PPARγ activity or down-regulation of Early growth response protein 1 (Egr-1) expression, and the corresponding controls.InterventionsAcute lung inflammation is induced in the mice by airway deposition of IgG-IC. Activation of PPARγ is achieved by using its agonist Rosiglitazone or adenoviral vectors that could mediate overexpression of PPARγ. PPARγ activity is suppressed by application of its antagonist GW9662 or shRNA. Egr-1 expression is down-regulated by using the gene specific shRNA.Measures and Main ResultsWe find that during IgG-IC-induced acute lung inflammation, PPARγ expression at both RNA and protein levels is repressed, which is consistent with the results obtained from macrophages treated with IgG-IC. Furthermore, both in vivo and in vitro data show that PPARγ activation reduces IgG-IC-mediated pro-inflammatory mediators’ production, thereby alleviating lung injury. In terms of mechanism, we observe that the generation of Egr-1 elicited by IgG-IC is inhibited by PPARγ. As an important transcription factor, Egr-1 transcription is substantially increased by IgG-IC in both in vivo and in vitro studies, leading to augmented protein expression, thus amplifying IgG-IC-triggered expressions of inflammatory factors via association with their promoters.ConclusionDuring IgG-IC-stimulated acute lung inflammation, PPARγ activation can relieve the inflammatory response by suppressing the expression of its downstream target Egr-1 that directly binds to the promoter regions of several inflammation-associated genes. Therefore, regulation of PPARγ-Egr-1-pro-inflammatory mediators axis by PPARγ agonist Rosiglitazone may represent a novel strategy for blockade of acute lung injury.

scholarly journals Veronicastrum axillare Alleviates Lipopolysaccharide-Induced Acute Lung Injury via Suppression of Proinflammatory Mediators and Downregulation of the NF-κB Signaling Pathway

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Quanxin Ma ◽  
Kai Wang ◽  
Qinqin Yang ◽  
Shun Ping ◽  
Weichun Zhao ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Biological Activities ◽  
Interleukin 1 ◽  
Folk Medicine ◽  
Protective Effects ◽  
Proinflammatory Mediators ◽  
Anti Inflammatory

Veronicastrum axillare is a traditional medical plant in China which is widely used in folk medicine due to its versatile biological activities, especially for its anti-inflammatory effects. However, the detailed mechanism underlying this action is not clear. Here, we studied the protective effects of V. axillare against acute lung injury (ALI), and we further explored the pharmacological mechanisms of this action. We found that pretreatment with V. axillare suppressed the release of proinflammatory cytokines in the serum of ALI mice. Histological analysis of lung tissue demonstrated that V. axillare inhibited LPS-induced lung injury, improved lung morphology, and reduced the activation of nuclear factor-κB (NF-κB) in the lungs. Furthermore, the anti-inflammatory actions of V. axillare were investigated in vitro. We observed that V. axillare suppressed the mRNA expression of interleukin-1β (IL-1β), IL-6, monocyte chemotactic protein-1 (MCP-1), cyclooxygenase-2 (COX-2), and tumor necrosis factor-α (TNF-α) in RAW264.7 cells challenged with LPS. Furthermore, pretreatment of V. axillare in vitro reduced the phosphorylation of p65 and IκB-α which is activated by LPS. In conclusion, our data firstly demonstrated that the anti-inflammatory effects of V. axillare against ALI were achieved through downregulation of the NF-κB signaling pathway, thereby reducing the production of inflammatory mediators.

scholarly journals Anemoside B4 Protects against Acute Lung Injury by Attenuating Inflammation through Blocking NLRP3 Inflammasome Activation and TLR4 Dimerization

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Renyikun Yuan ◽  
Jia He ◽  
Liting Huang ◽  
Li-Jun Du ◽  
Hongwei Gao ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Protective Effect ◽  
Inflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Macrophage Cells ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Acute lung injury (ALI) is an acute inflammatory process in the lung parenchyma. Anemoside B4 (B4) was isolated from Pulsatilla, a plant-based drug against inflammation and commonly applied in traditional Chinese medicine. However, the anti-inflammatory effect and the mechanisms of B4 are not clear. In this study, we explored the potential mechanisms and anti-inflammatory activity of B4 both in vitro and in vivo. The results indicated that B4 suppressed the expression of iNOS, COX-2, NLRP3, caspase-1, and IL-1β. The ELISA assay results showed that B4 significantly restrained the release of inflammatory cytokines like TNF-α, IL-6, and IL-1β in macrophage cells. In addition, B4 rescued mitochondrial membrane potential (MMP) loss in (lipopolysaccharide) LPS plus ATP stimulated macrophage cells. Co-IP and molecular docking results illustrated that B4 disrupted the dimerization of TLR4. For in vivo results, B4 exhibited a protective effect on LPS and bleomycin- (BLM-) induced ALI in mice through suppressing the lesions of lung tissues, the release of inflammatory cytokines, and the levels of white blood cells, neutrophils, and lymphoid cells in the blood. Collectively, B4 has a protective effect on ALI via blocking TLR4 dimerization and NLRP3 inflammasome activation, suggesting that B4 is a potential agent for the treatment of ALI.

scholarly journals Role of LecA and LecB Lectins in Pseudomonas aeruginosa-Induced Lung Injury and Effect of Carbohydrate Ligands

2009 ◽  
Vol 77 (5) ◽  
pp. 2065-2075 ◽  
Author(s):  
Chanez Chemani ◽  
Anne Imberty ◽  
Sophie de Bentzmann ◽  
Maud Pierre ◽  
Michaela Wimmerová ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Parental Strain ◽  
A549 Cells ◽  
Carbohydrate Ligands ◽  
Vitro Model

ABSTRACT Pseudomonas aeruginosa is a frequently encountered pathogen that is involved in acute and chronic lung infections. Lectin-mediated bacterium-cell recognition and adhesion are critical steps in initiating P. aeruginosa pathogenesis. This study was designed to evaluate the contributions of LecA and LecB to the pathogenesis of P. aeruginosa-mediated acute lung injury. Using an in vitro model with A549 cells and an experimental in vivo murine model of acute lung injury, we compared the parental strain to lecA and lecB mutants. The effects of both LecA- and Lec B-specific lectin-inhibiting carbohydrates (α-methyl-galactoside and α-methyl-fucoside, respectively) were evaluated. In vitro, the parental strain was associated with increased cytotoxicity and adhesion on A549 cells compared to the lecA and lecB mutants. In vivo, the P. aeruginosa-induced increase in alveolar barrier permeability was reduced with both mutants. The bacterial burden and dissemination were decreased for both mutants compared with the parental strain. Coadministration of specific lectin inhibitors markedly reduced lung injury and mortality. Our results demonstrate that there is a relationship between lectins and the pathogenicity of P. aeruginosa. Inhibition of the lectins by specific carbohydrates may provide new therapeutic perspectives.

scholarly journals GLP-1 Analogue Liraglutide Enhances SP-A Expression in LPS-Induced Acute Lung Injury through the TTF-1 Signaling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhu ◽  
Changyi Li ◽  
Xue Zhang ◽  
Chunyan Ye ◽  
Shuo Tang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Signaling Pathway ◽  
Pulmonary Inflammation ◽  
Protein A ◽  
Insulin Level ◽  
Underlying Mechanism ◽  
Ultrastructural Changes

The reduction of pulmonary surfactant (PS) is essential for decreased pulmonary compliance and edema in acute lung injury (ALI). Thyroid transcription factor-1 (TTF-1) plays a major role in the regulation of surfactant protein-A (SP-A), the most abundant protein component of PS. Simultaneously, the glucagon-like peptide-1 (GLP-1) analogue can enhance SP-A expression in the lung. However, the underlying mechanism is still unknown. The purpose of this study was to explore whether liraglutide, a GLP-1 analogue, upregulates SP-A expression through the TTF-1 signaling pathway in ALI. In vivo, a murine model of ALI was induced by lipopolysaccharide (LPS). Pulmonary inflammation, edema, insulin level, ultrastructural changes in type II alveolar epithelial (ATII) cells, and SP-A and TTF-1 expression were analyzed. In vitro, rat ATII cells were obtained. SP-A and TTF-1 expression in cells was measured. ShRNA-TTF-1 transfection was performed to knock down TTF-1 expression. Our data showed that LPS-induced lung injury and increase in insulin level, and LPS-induced reduction of SP-A and TTF-1 expression in both the lung and cells, were significantly compromised by liraglutide. Furthermore, we also found that these effects of liraglutide were markedly blunted by shRNA-TTF-1. Taken together, our findings suggest that liraglutide enhances SP-A expression in ATII cells and attenuates pulmonary inflammation in LPS-induced ALI, most likely through the TTF-1 signaling pathway.

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