scholarly journals Inflammasome Inhibition Suppresses Alveolar Cell Permeability Through Retention of Neuregulin-1 (NRG-1)

2015 ◽  
Vol 36 (5) ◽  
pp. 2012-2024 ◽  
Author(s):  
Rajanbabu Venugopal ◽  
Lakshmi Galam ◽  
Ruan Cox ◽  
Jutaro Fukumoto ◽  
Young Cho ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Lucifer Yellow ◽  
Pulmonary Inflammation ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Cell Permeability ◽  
Epithelial Permeability ◽  
Alveolar Cell ◽  
Alveolar Permeability ◽  
Her2 Signaling

Background: Neuregulin (NRG)-1-human epidermal receptor (HER)-2 signaling pathway is a key regulator of IL-1β-mediated pulmonary inflammation and epithelial permeability. The inflammasome is a newly discovered molecular platform required for caspase-1 activation and maturation of IL-1β. However, the role of the inflammasome in NRG-1-HER2 signaling-mediated alveolar cell permeability is unknown. Methods: The inflammasome was activated or inhibited in THP-1 cells; supernatants from these cells were added to A549 cells and human small airway epithelial cells (HSAEC). The protein expression of NRG-1 and phospho-HER2 (pHER2) were measured by Western blot analysis and epithelial permeability was measured using Lucifer yellow dye. Results: Results reveal that alveolar permeability in A549 cells and HSAEC is increased when treated with supernatants of inflammasome-activated THP-1 cells. Alveolar permeability is significantly suppressed when treated with supernatant of inflammasome-inhibited THP-1 cells. Inflammasome-mediated permeability is decreased when A549 cells and HSAEC are pretreated with IL-1β receptor antagonist (IL-1βRA). In addition, HER2 kinase inhibitor AG825 or NRG-1 inhibitor TAPI inhibits inflammasome-mediated permeability in A549 cells and HSAEC demonstrating critical roles of IL-1β, NRG-1, and HER2 in inflammasome-mediated alveolar permeability. Conclusion: These findings suggest that inflammasome-induced alveolar cell permeability is mediated by NRG-1/HER2 signaling through IL-1β regulation.

scholarly journals Anti-Inflammatory Properties of Fructo-Oligosaccharides in a Calf Lung Infection Model and in Mannheimia haemolytica-Infected Airway Epithelial Cells

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3514
Author(s):  
Yang Cai ◽  
Myrthe S. Gilbert ◽  
Walter J. J. Gerrits ◽  
Gert Folkerts ◽  
Saskia Braber
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Mannheimia Haemolytica ◽  
Epithelial Barrier ◽  
Infection Model ◽  
Airway Epithelial ◽  
Clinical Scores ◽  
Lung Infections ◽  
Anti Inflammatory

Emerging antimicrobial-resistant pathogens highlight the importance of developing novel interventions. Here, we investigated the anti-inflammatory properties of Fructo-oligosaccharides (FOS) in calf lung infections and in airway epithelial cells stimulated with pathogens, and/or bacterial components. During a natural exposure, 100 male calves were fed milk replacer with or without FOS for 8 weeks. Then, immune parameters and cytokine/chemokine levels in the bronchoalveolar lavage fluid (BALF) and blood were measured, and clinical scores were investigated. Calf primary bronchial epithelial cells (PBECs) and human airway epithelial cells (A549) were treated with Mannheimia haemolytica, lipopolysaccharides (LPS), and/or flagellin, with or without FOS pretreatment. Thereafter, the cytokine/chemokine levels and epithelial barrier function were examined. Relative to the control (naturally occurring lung infections), FOS-fed calves had greater macrophage numbers in BALF and lower interleukin (IL)-8, IL-6, and IL-1β concentrations in the BALF and blood. However, FOS did not affect the clinical scores. At slaughter, FOS-fed calves had a lower severity of lung lesions compared to the control. Ex vivo, FOS prevented M. haemolytica-induced epithelial barrier dysfunction. Moreover, FOS reduced M. haemolytica- and flagellin-induced (but not LPS-induced) IL-8, TNF-α, and IL-6 release in PBECs and A549 cells. Overall, FOS had anti-inflammatory properties during the natural incidence of lung infections but had no effects on clinical symptoms.

Hypoxia induces hexokinase II gene expression in human lung cell line A549

2000 ◽  
Vol 278 (2) ◽  
pp. L407-L416 ◽  
Author(s):  
Suzette R. Riddle ◽  
Aftab Ahmad ◽  
Shama Ahmad ◽  
Samir S. Deeb ◽  
Mari Malkki ◽  
...  
Keyword(s):  
Luciferase Activity ◽  
Regulatory Region ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Luciferase Reporter ◽  
Airway Epithelial ◽  
Hexokinase Ii ◽  
Pulmonary Cells ◽  
Promoter Construct ◽  
Human Lung Cell Line

During adaptation to hypoxic and hyperoxic conditions, the genes involved in glucose metabolism are upregulated. To probe involvement of the transcription factor hypoxia-induced factor-1 (HIF-1) in hexokinase (HK) II expression in human pulmonary cells, A549 cells and small-airway epithelial cells (SAECs) were exposed to stimuli such as hypoxia, deferoxamine (DFO), and metal ions. The largest increase in HK-II (20-fold for mRNA and 2.5-fold for enzymatic activity) was observed in A549 cells when exposed to DFO. All stimuli selectively increased the 5.5-kb rather than 4-kb transcript in A549 cells. Cycloheximide and actinomycin D inhibited these responses. In addition, cells were transfected with luciferase reporter constructs driven by the full-length HK-II 5′-regulatory region (4.0 kb) or various deletions of that region. A549 cells transfected with the 4.0-kb construct and exposed to hypoxia or DFO increased their luciferase activity 7- and 10-fold, respectively, indicating that HK-II induction is, at least in part, due to increased gene transcription. Sixty percent of the inducible activity of the 4.0-kb construct was shown to reside within the proximal 0.5 kb. Additionally, cotransfection with a stable HIF-1 mutant and the 4.0-kb promoter construct resulted in increased luciferase activity under normoxic conditions. These results strongly suggest that HK-II is selectively regulated in pulmonary cells by a HIF-1-dependent mechanism.

scholarly journals Astragalin Inhibits Pulmonary Inflammation in Cigarette Smoking-Induced Embolism

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1526-1526
Author(s):  
Yun-Ho Kim ◽  
Young-Hee Kang
Keyword(s):  
Pulmonary Embolism ◽  
Cigarette Smoking ◽  
Pulmonary Inflammation ◽  
A549 Cells ◽  
Coagulation Factor ◽  
Alveolar Epithelial Cells ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Alveolar Cells ◽  
Alveolar Epithelial

Abstract Objectives Thrombin generation is crucial to the regulation of hemostasis and thrombosis and is essential to the pathogenesis of cardiovascular disease and venous thrombosis. Pulmonary embolism is a blockage in one of the pulmonary arteries in your lung caused by blood clots due to risk factors including tobacco use. Astragalin (kaempferol 3-O-glucoside) is a flavonoid present in persimmon leaves and green tea seeds and exhibits diverse activities such as asthma and obstructive pulmonary disease. This study investigated that astragalin encumbered pulmonary inflammation caused by cigarette smoking-induced embolism. Methods Pulmonary embolism was evoked through exposure of BALB/c mice to cigarette smoke for 30 min, five days a week for eight weeks. Mice were orally administrated with 10 or 20 mg/kg astragalin for 8 weeks. For the in vitro studies, 10 U/ml thrombin was loaded to alveolar epithelial A549 cells in the absence and presence of 1–20 μM astragalin. Results Oral supplementation of astragalin reduced tissue factor and urokinase-type plasminogen activator elevated in cigarette smoking-exposed lungs. In addition, 1–20 μM astragalin attenuated the induction of protease activated receptor-1 known as coagulation factor II (thrombin) receptor-like-1, in 10 U/ml thrombin-loaded alveolar epithelial cells. Astragalin curtailed induction of the inflammatory mediators of cyclooxygenase-2, intercellular adhesion molecule-1 and inducible nitric oxide synthase in alveolar cells subjected to thrombin. Furthermore, astragalin inhibited inflammatory signaling entailing MAPK/ERK pathway. Conclusions Astragalin may be a potential agent alleviating pulmonary inflammation induced by cigarette smoking-induced embolism. Funding Sources This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2019R1A6A3A01094891).

scholarly journals Aesculetin Inhibits Pulmonary Fibrosis by Epithelial-to-mesenchymal Transition(EMT) in a Alveolar Epithelial Cell (P06-068-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Su Yeon Oh ◽  
Young-Hee Kang
Keyword(s):  
Pulmonary Fibrosis ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Alveolar Epithelial Cell ◽  
Smooth Muscle Actin ◽  
Pulmonary Inflammation ◽  
A549 Cells ◽  
Conditioned Media ◽  
Alveolar Cells ◽  
Mesenchymal Transition

Abstract Objectives Pulmonary fibrosis is a disease in which lung tissues become fibrous and causes severe respiratory disturbances. Various stimuli induce infiltration of macrophages to the respiratory tract. These macrophages secrete various cytokines leading to development of pulmonary fibrosis. Aesculetin, a major component of Sancho tree and Chicory, is known to have antioxidant and anti-inflammatory effects in the vascular and immune system. However, its effect on pulmonary fibrosis has been poorly understood. The current study investigated that aesculetin inhibited pulmonary fibrosis caused by infiltration of monocyte-derived macrophages. Methods To differentiate to monocyte-derived macrophages, THP-1 human mononuclear cell line was treated with 50 ng/ml phorbol myristate acetate (PMA) for 24 h. Culture conditioned media were harvested from macrophages cultured in the absence of PMA for 24 h. A549 human alveolar basal epithelial cells were cultured in the conditioned media for 24 h to induce alveolar fibrosis. Epithelial–mesenchymal transition (EMT)-associated fibrotic proteins were measured with Western blotting from A549 cell lysates. Results Aesculetin at the concentrations of 1–20 μM did not show any toxicity of A549 cells, evidence by MTT assay. When A549 cells were treated with conditioned media from monocyte-derived macrophages, the expression of mesenchymal fibrotic proteins of α-smooth muscle actin and fibronectin was highly enhanced. In contrast, ≥10 μM aesculetin inhibited the induction of these proteins of A549 cells. The expression of E-cadherin and Zonula occludens-1 was reduced in cells supplemented with conditioned media, while aesculetin promoted these epithelial phenotypic proteins in conditioned media-exposed alveolar cells. Conclusions These results demonstrate that aesculetin may ameliorate EMT-associated alveolar fibrosis caused by monocyte-derived macrophages infiltrated into the alveoli. Therefore, Aesculetin maybe a promising agent treating progressive pulmonary disorders owing to pulmonary inflammation. Funding Sources This work (Grants No. C0501612) was supported by project for Cooperative R&D between Industry, Academy, and Research Institute funded Korea Ministry of SMEs and Startups in 20.

scholarly journals Participation of CD11c+Leukocytes in Methicillin-Resistant Staphylococcus aureus Clearance from the Lung

2011 ◽  
Vol 79 (5) ◽  
pp. 1898-1904 ◽  
Author(s):  
Francis J. Martin ◽  
Dane Parker ◽  
Bryan S. Harfenist ◽  
Grace Soong ◽  
Alice Prince
Keyword(s):  
Staphylococcus Aureus ◽  
Pulmonary Infection ◽  
Fluorescent Protein ◽  
Pulmonary Inflammation ◽  
Bacterial Load ◽  
Airway Epithelial Cells ◽  
High Morbidity ◽  
Proinflammatory Response ◽  
Methicillin Resistant ◽  
Content Type

ABSTRACTStaphylococcus aureuscauses especially severe pulmonary infection, associated with high morbidity and mortality. In addition to the effects of specific virulence factors, it appears that the intensity of the host proinflammatory response, particularly in the initial stages of infection, contributes substantially to pulmonary damage. We tested the hypothesis that the CD11c+leukocytes are important in the host response to pulmonary infection with methicillin-resistantS. aureus(MRSA) USA300. Clodronate-induced depletion of the alveolar macrophage population resulted in increased numbers of dendritic cells (DCs) and CD4+cells in bronchoalveolar lavage (BAL) fluid and was associated with significantly increased mortality by 18 h followingS. aureusinoculation but had no effect on bacterial load or polymorphonuclear leukocyte (PMN) numbers in the lung. These clodronate-treated mice also had increased expression of interleukin-17A/F (IL-17A/F) and CXCL10 but not of gamma interferon (IFN-γ) or tumor necrosis factor (TNF). Depletion of the dendritic cell population in mice expressing a CD11c-enhanced green fluorescent protein (EGFP)-diphtheria toxin receptor (DTR) transgene was associated with an increased bacterial load in the lung but not increased mortality. Both DCs and airway epithelial cells produced CXCL9, -10, and -11 in response toS. aureus. Pretreatment of mice with an anti-CXCR3 antibody prior to inoculation with MRSA substantially reduced CD4+cells and decreased pulmonary inflammation at 18 h postinfection compared to pretreatment with an IgG control. The results of these experiments suggest that CD11c+cells, the induction of CXCR3 ligand expression, and subsequent CD4+cell recruitment have an important role in the pathogenesis of severe MRSA pulmonary infection.

Effect of defensins on interleukin-8 synthesis in airway epithelial cells

1997 ◽  
Vol 272 (5) ◽  
pp. L888-L896 ◽  
Author(s):  
S. Van Wetering ◽  
S. P. Mannesse-Lazeroms ◽  
M. A. Van Sterkenburg ◽  
M. R. Daha ◽  
J. H. Dijkman ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Neutrophil Elastase ◽  
Proteinase Inhibitor ◽  
De Novo ◽  
Tissue Injury ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Epithelial Cell Line ◽  
Mrna Levels ◽  
Airway Epithelial

Neutrophils play an important role in inflammatory processes in the lung and may cause tissue injury through, for example, release of proteinases such as neutrophil elastase. In addition to neutrophil elastase, stimulated neutrophils also release small nonenzymatic and cationic polypeptides termed defensins. The aim of the present study was to investigate whether defensins induce interleukin (IL)-8 expression in cells of the A549 lung epithelial cell line and in human primary bronchial epithelial cells (PBEC). Supernatants of defensin-treated A549 cells contained increased neutrophil chemotactic activity (16-fold) that was inhibited by antibodies against IL-8. Concurrently, within 3 and 6 h, defensins significantly increased the IL-8 levels in supernatants of both A549 cells (n = 6, P < 0.05 and P < 0.01, respectively) and PBEC (n = 4, P < 0.001 and P < 0.001, respectively). This defensin-induced increase was fully inhibited by the serine proteinase inhibitor alpha 1-proteinase inhibitor. In addition, defensins also increased IL-8 mRNA levels (12-fold); this increase was dependent on de novo mRNA synthesis and did not require protein synthesis. Furthermore, defensins did not affect IL-8 mRNA stability, indicating that the enhanced IL-8 expression was due to increased transcription. Our findings suggest that defensins, released by stimulated neutrophils, stimulate IL-8 synthesis by airway epithelial cells and thus may mediate the recruitment of additional neutrophils into the airways.

Pseudomonas aeruginosapyocyanin directly oxidizes glutathione and decreases its levels in airway epithelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L94-L103 ◽  
Author(s):  
Yunxia Q. O'Malley ◽  
Krzysztof J. Reszka ◽  
Douglas R. Spitz ◽  
Gerene M. Denning ◽  
Bradley E. Britigan
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Culture Media ◽  
Alveolar Epithelial Cell ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Alternative Source ◽  
Cell Functions

Production of pyocyanin enhances Pseudomonas aeruginosa virulence. Many of pyocyanin's in vitro and in vivo cytotoxic effects on human cells appear to result from its ability to redox cycle. Pyocyanin directly accepts electrons from NADH or NADPH with subsequent electron transfer to oxygen, generating reactive oxygen species. Reduced glutathione (GSH) is an important cellular antioxidant, and it contributes to the regulation of redox-sensitive signaling systems. Using the human bronchial epithelial (HBE) and the A549 human type II alveolar epithelial cell lines, we tested the hypothesis that pyocyanin can deplete airway epithelial cells of GSH. Incubation of both cell types with pyocyanin led to a concentration-dependent loss of cellular GSH (up to 50%) and an increase in oxidized GSH (GSSG) in the HBE, but not A549 cells, at 24 h. An increase in total GSH, mostly as GSSG, was detected in the culture media, suggesting export of GSH or GSSG from the pyocyanin-exposed cells. Loss of GSH could be due to pyocyanin-induced H2O2formation. However, overexpression of catalase only partially prevented the pyocyanin-mediated decline in cellular GSH. Cell-free electron paramagnetic resonance studies revealed that pyocyanin directly oxidizes GSH, forming pyocyanin free radical and O2−·. Pyocyanin oxidized other thiol-containing compounds, cysteine and N-acetyl-cysteine, but not methionine. Thus GSH may enhance pyocyanin-induced cytotoxicity by functioning as an alternative source of reducing equivalents for pyocyanin redox cycling. Pyocyanin-mediated alterations in cellular GSH may alter epithelial cell functions by modulating redox sensitive signaling events.

Anti-inflammatory effects of resveratrol in lung epithelial cells: molecular mechanisms

2004 ◽  
Vol 287 (4) ◽  
pp. L774-L783 ◽  
Author(s):  
Louise E. Donnelly ◽  
Robert Newton ◽  
Gina E. Kennedy ◽  
Peter S. Fenwick ◽  
Rachel H. F. Leung ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Colony Stimulating Factor ◽  
Macrophage Colony Stimulating Factor ◽  
Anti Inflammatory ◽  
Macrophage Colony ◽  
Stimulating Factor ◽  
Factor Release

Resveratrol (3,4′,5-trihydroxystilbene) is a polyphenolic stilbene found in the skins of red fruits, including grapes, that may be responsible for some of the health benefits ascribed to consumption of red wine. Resveratrol has been shown to have antioxidant properties and can act as an estrogen agonist. This study examined the anti-inflammatory effects of resveratrol on human airway epithelial cells. Resveratrol and the related molecule quercetin, but not deoxyrhapontin, inhibited IL-8 and granulocyte-macrophage colony-stimulating factor release from A549 cells. Neither the estrogen receptor antagonist tamoxifen nor the glucocorticoid antagonist mifepristone altered the inhibitory effect of resveratrol. The mechanism of resveratrol action was investigated further using luciferase reporter genes stably transfected into A549 cells. Resveratrol and quercetin inhibited NF-κB-, activator protein-1-, and cAMP response element binding protein-dependent transcription to a greater extent than the glucocorticosteroid dexamethasone. These compounds also had no significant effect on acetylation or deacetylation of core histones. Resveratrol, but not estradiol or N-acetyl cysteine, inhibited cytokine-stimulated inducible nitric oxide synthase expression and nitrite production (IC50 = 3.6 ± 2.9 μM) in human primary airway epithelial cells. Resveratrol also inhibited granulocyte-macrophage colony-stimulating factor release (IC50 = 0.44 ± 0.17 μM), IL-8 release (IC50 = 4.7 ± 3.3 μM), and cyclooxygenase-2 expression in these cells. This study demonstrates that resveratrol and quercetin have novel nonsteroidal anti-inflammatory activity that may have applications for the treatment of inflammatory diseases.

Bradykinin increases IL-8 generation in airway epithelial cells via COX-2-derived prostanoids

2002 ◽  
Vol 283 (3) ◽  
pp. L612-L618 ◽  
Author(s):  
Helen C. Rodgers ◽  
Linhua Pang ◽  
Elaine Holland ◽  
Lisa Corbett ◽  
Simon Range ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Prostaglandin E ◽  
Airway Epithelial ◽  
Neutrophilic Inflammation ◽  
Airway Diseases ◽  
Cox Inhibitor ◽  
Cox 2

Interleukin (IL)-8, the C-X-C chemokine, is a potent neutrophil chemoattractant that has been implicated in a number of inflammatory airway diseases such as cystic fibrosis. Here we tested the hypothesis that bradykinin, an inflammatory mediator and chloride secretagogue, would increase IL-8 generation in airway epithelial cells through autocrine generation of endogenous prostanoids. Bradykinin increased IL-8 generation in both a non-cystic fibrosis (A549) and cystic fibrosis epithelial cell line (CFTE29[Formula: see text]) that was inhibited by the nonselective cyclooxygenase (COX) inhibitor indomethacin and the COX-2 selective inhibitor NS-398. COX-2 was the only isoform of COX expressed in both cell lines. Furthermore, the COX substrate arachidonic acid and exogenous prostaglandin E2 both increased IL-8 release in A549 cells. These results suggest that bradykinin may contribute to neutrophilic inflammation in the airway by generation of IL-8 from airway epithelial cells. The dependence of this response on endogenous production of prostanoids by COX-2 suggests that selective COX-2 inhibitors may have a role in the treatment of airway diseases characterized by neutrophilic inflammation such as cystic fibrosis or chronic obstructive pulmonary disease.

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