scholarly journals Endoplasmic Reticulum Stress Is a Danger Signal Promoting Innate Inflammatory Responses in Bronchial Epithelial Cells

2016 ◽  
Vol 8 (5) ◽  
pp. 464-478 ◽  
Author(s):  
Vedrana Mijošek ◽  
Felix Lasitschka ◽  
Arne Warth ◽  
Heike Zabeck ◽  
Alexander H. Dalpke ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Er Stress ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Airway Epithelial ◽  
Danger Signal ◽  
Tlr Signaling ◽  
Mapk Activation ◽  
Bronchial Epithelial

Endoplasmic reticulum (ER) stress is associated with chronic pulmonary inflammatory diseases. We hypothesized that the combined activation of both Toll-like receptor (TLR) signaling and ER stress might increase inflammatory reactions in otherwise tolerant airway epithelial cells. Indeed, ER stress resulted in an increased response of BEAS-2B and human primary bronchial epithelial cells to pathogen-associated molecular pattern stimulation with respect to IL6 and IL8 production. ER stress elevated p38 and ERK MAP kinase activation, and pharmacological inhibition of these kinases could inhibit the boosting effect. Knockdown of unfolded protein response signaling indicated that mainly PERK and ATF6 were responsible for the synergistic activity. Specifically, PERK and ATF6 mediated increased MAPK activation, which is needed for effective cytokine secretion. We conclude that within airway epithelial cells the combined activation of TLR signaling and ER stress-mediated MAPK activation results in synergistic proinflammatory activity. We speculate that ER stress, present in various chronic pulmonary diseases, boosts TLR signaling and therefore proinflammatory cytokine production, thus acting as a costimulatory danger signal.

ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells

1999 ◽  
Vol 277 (3) ◽  
pp. L465-L471 ◽  
Author(s):  
Alessandro Celi ◽  
Silvana Cianchetti ◽  
Stefano Petruzzelli ◽  
Stefano Carnevali ◽  
Filomena Baliva ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Neutrophil Adhesion ◽  
Late Time ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Human Airway ◽  
Stimulation Of ◽  
Human Airway Epithelial Cells

Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 ± 3 to 49 ± 7% (SE). A significant increase from 17 ± 4 to 39 ± 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin β-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.

scholarly journals Activity and inhibition of prostasin and matriptase on apical and basolateral surfaces of human airway epithelial cells

2012 ◽  
Vol 303 (2) ◽  
pp. L97-L106 ◽  
Author(s):  
Shilpa Nimishakavi ◽  
Marina Besprozvannaya ◽  
Wilfred W. Raymond ◽  
Charles S. Craik ◽  
Dieter C. Gruenert ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Selective Inhibition ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Apical Surface ◽  
Airway Epithelial ◽  
Wild Type ◽  
Bronchial Epithelial

Prostasin is a membrane-anchored protease expressed in airway epithelium, where it stimulates salt and water uptake by cleaving the epithelial Na+ channel (ENaC). Prostasin is activated by another transmembrane tryptic protease, matriptase. Because ENaC-mediated dehydration contributes to cystic fibrosis (CF), prostasin and matriptase are potential therapeutic targets, but their catalytic competence on airway epithelial surfaces has been unclear. Seeking tools for exploring sites and modulation of activity, we used recombinant prostasin and matriptase to identify substrate t-butyloxycarbonyl-l-Gln-Ala-Arg-4-nitroanilide (QAR-4NA), which allowed direct assay of proteases in living cells. Comparisons of bronchial epithelial cells (CFBE41o−) with and without functioning cystic fibrosis transmembrane conductance regulator (CFTR) revealed similar levels of apical and basolateral aprotinin-inhibitable activity. Although recombinant matriptase was more active than prostasin in hydrolyzing QAR-4NA, cell surface activity resisted matriptase-selective inhibition, suggesting that prostasin dominates. Surface biotinylation revealed similar expression of matriptase and prostasin in epithelial cells expressing wild-type vs. ΔF508-mutated CFTR. However, the ratio of mature to inactive proprostasin suggested surface enrichment of active enzyme. Although small amounts of matriptase and prostasin were shed spontaneously, prostasin anchored to the cell surface by glycosylphosphatidylinositol was the major contributor to observed QAR-4NA-hydrolyzing activity. For example, the apical surface of wild-type CFBE41o− epithelial cells express 22% of total, extractable, aprotinin-inhibitable, QAR-4NA-hydrolyzing activity and 16% of prostasin immunoreactivity. In conclusion, prostasin is present, mature and active on the apical surface of wild-type and CF bronchial epithelial cells, where it can be targeted for inhibition via the airway lumen.

scholarly journals Capsular Polysaccharide is a Main Component ofMycoplasma ovipneumoniaein the Pathogen-Induced Toll-Like Receptor-Mediated Inflammatory Responses in Sheep Airway Epithelial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Zhongjia Jiang ◽  
Fuyang Song ◽  
Yanan Li ◽  
Di Xue ◽  
Guangcun Deng ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Capsular Polysaccharide ◽  
Inflammatory Responses ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Atypical Pneumonia ◽  
Activator Protein 1 ◽  
Airway Epithelial ◽  
Toll Like Receptor ◽  
Bronchial Epithelial

Mycoplasma ovipneumoniae(M. ovipneumoniae) is characterized as an etiological agent of primary atypical pneumonia that specifically infects sheep and goat. In an attempt to better understand the pathogen-host interaction between the invadingM. ovipneumoniaeand airway epithelial cells, we investigated the host inflammatory responses against capsular polysaccharide (designated as CPS) ofM. ovipneumoniaeusing sheep bronchial epithelial cells cultured in an air-liquid interface (ALI) model. Results showed that CPS derived fromM. ovipneumoniaecould activate toll-like receptor- (TLR-) mediated inflammatory responses, along with an elevated expression of nuclear factor kappa B (NF-κB), activator protein-1 (AP-1), and interferon regulatory factor 3 (IRF3) as well as various inflammatory-associated mediators, representatively including proinflammatory cytokines, such as IL1β, TNFα, and IL8, and anti-inflammatory cytokines such as IL10 and TGFβof TLR signaling cascade. Mechanistically, the CPS-induced inflammation was TLR initiated and was mediated by activations of both MyD88-dependent and MyD88-independent signaling pathways. Of importance, a blockage of CPS with specific antibody led a significant reduction ofM. ovipneumoniae-induced inflammatory responses in sheep bronchial epithelial cells. These results suggested that CPS is a key virulent component ofM. ovipneumoniae, which may play a crucial role in the inflammatory response induced byM. ovipneumoniaeinfections.

Regulation of SLPI and elafin release from bronchial epithelial cells by neutrophil defensins

2000 ◽  
Vol 278 (1) ◽  
pp. L51-L58 ◽  
Author(s):  
Sandra van Wetering ◽  
Abraham C. van der Linden ◽  
Marianne A. J. A. van Sterkenburg ◽  
Willem I. de Boer ◽  
Astrid L. A. Kuijpers ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Proteinase Inhibitor ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Protein Release ◽  
Mrna Levels ◽  
Main Function ◽  
Airway Epithelial ◽  
Dynamic Regulation ◽  
Bronchial Epithelial

Secretory leukocyte proteinase inhibitor (SLPI) is a serine proteinase inhibitor that is produced locally in the lung by cells of the submucosal bronchial glands and by nonciliated epithelial cells. Its main function appears to be the inhibition of neutrophil elastase (NE). Recently, NE was found to enhance SLPI mRNA levels while decreasing SLPI protein release in airway epithelial cells. Furthermore, glucocorticoids were shown to increase both constitutive and NE-induced SLPI mRNA levels. In addition to NE, stimulated neutrophils also release α-defensins. Defensins are small, antimicrobial polypeptides that are found in high concentrations in purulent secretions of patients with chronic airway inflammation. Like NE, defensins induce interleukin-8 production in airway epithelial cells. This induction is sensitive to inhibition by the glucocorticoid dexamethasone and is prevented in the presence of α1-proteinase inhibitor. The aim of the present study was to investigate the effect of defensins on the production of SLPI and the related NE inhibitor elafin/SKALP in primary bronchial epithelial cells (PBECs). Defensins significantly increase SLPI protein release by PBECs in a time- and dose-dependent fashion without affecting SLPI mRNA synthesis. In the presence of α1-proteinase inhibitor, the defensin-induced SLPI protein release is further enhanced, but no effect was observed on SLPI mRNA levels. Dexamethasone did not affect SLPI protein release from control or defensin-treated PBECs. In addition, we observed a constitutive release of elafin/SKALP by PBECs, but this was not affected by defensins. The present results suggest a role for defensins in the dynamic regulation of the antiproteinase screen in the lung at sites of inflammation.

Reactive oxygen intermediates stimulate interleukin-6 production in human bronchial epithelial cells

1999 ◽  
Vol 276 (6) ◽  
pp. L900-L908 ◽  
Author(s):  
Yoshimasa Yoshida ◽  
Muneharu Maruyama ◽  
Tadashi Fujita ◽  
Nobuki Arai ◽  
Ryuji Hayashi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Lung Fibroblasts ◽  
Mrna Levels ◽  
Airway Epithelial ◽  
Human Bronchial Epithelial Cells ◽  
Oxygen Intermediates ◽  
Bronchial Epithelial ◽  
Tnf Α

Reactive oxygen intermediates (ROIs) play an important role in the initiation and progression of lung diseases. In this study, we investigated whether ROIs were involved in the induction of interleukin (IL)-6 in human bronchial epithelial cells. We exposed normal human bronchial epithelial cells as well as a human bronchial epithelial cell line, HS-24, to ROIs. We measured the amount of IL-6 in the culture supernatants using ELISA and the IL-6 mRNA levels using RT-PCR. Superoxide anions ([Formula: see text]), but not hydrogen peroxide (H2O2), increased IL-6 production. To examine whether it is a cell type-specific mechanism of airway epithelial cells, the experiments were also performed in human lung fibroblasts, WI-38-40. In WI-38-40 cells, neither [Formula: see text] nor H2O2increased IL-6 production. In contrast, tumor necrosis factor (TNF)-α (200 U/ml) induced IL-6 at the protein and mRNA levels in both airway epithelial cells and lung fibroblasts. This cytokine-induced IL-6 production was significantly suppressed by several antioxidants, including dimethyl sulfoxide (DMSO), in airway epithelial cells. In WI-38-40 cells, DMSO was not able to suppress IL-6 production induced by TNF-α. Pretreatment with DMSO recovered the TNF-α-induced depletion of intracellular reduced glutathione in HS-24 cells. These findings indicate that oxidant stress specifically induces IL-6 production in human bronchial epithelial cells and that in these cells ROIs may be involved in IL-6 production after stimulation with cytokines such as TNF-α. Presumably, ROIs participate in the local immune response in lung diseases via IL-6 release from bronchial epithelial cells.

scholarly journals Cytotoxicity and Induction of Inflammation by Pepsin in Acid in Bronchial Epithelial Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Erik Bathoorn ◽  
Paul Daly ◽  
Birgit Gaiser ◽  
Karl Sternad ◽  
Craig Poland ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Diseases ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Airway Remodelling ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Future Studies ◽  
Gastric Fluids ◽  
Ph Level

Introduction. Gastroesophageal reflux has been associated with chronic inflammatory diseases and may be a cause of airway remodelling. Aspiration of gastric fluids may cause damage to airway epithelial cells, not only because acidity is toxic to bronchial epithelial cells, but also since it contains digestive enzymes, such as pepsin.Aim. To study whether pepsin enhances cytotoxicity and inflammation in airway epithelial cells, and whether this is pH-dependent.Methods. Human bronchial epithelial cells were exposed to increasing pepsin concentrations in varying acidic milieus, and cell proliferation and cytokine release were assessed.Results. Cell survival was decreased by pepsin exposure depending on its concentration (F=17.4) and pH level of the medium (F=6.5) (bothP<0.01). Pepsin-induced interleukin-8 release was greater at lower pH (F=5.1;P<0.01). Interleukin-6 induction by pepsin was greater at pH 1.5 compared to pH 2.5 (mean difference 434%;P=0.03).Conclusion. Pepsin is cytotoxic to bronchial epithelial cells and induces inflammation in addition to acid alone, dependent on the level of acidity. Future studies should assess whether chronic aspiration causes airway remodelling in chronic inflammatory lung diseases.

Differentiation-dependent responsiveness of bronchial epithelial cells to IL-4/13 stimulation

2004 ◽  
Vol 287 (1) ◽  
pp. L119-L126 ◽  
Author(s):  
Tadashi Kikuchi ◽  
Jonathan D. Shively ◽  
John S. Foley ◽  
Jeffrey M. Drazen ◽  
Daniel J. Tschumperlin
Keyword(s):  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Airway Epithelial Cells ◽  
Culture Technique ◽  
Bronchial Epithelial Cells ◽  
Cytokine Secretion ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Gm Csf ◽  
Early Signal

The Th2 cytokines interleukin (IL)-4 and IL-13 are thought to play critical roles in the airway inflammation and hyperresposiveness that characterize asthma. Recent evidence indicates that IL-13 can mediate these effects by acting directly on airway epithelial cells. Here we evaluated early [signal transducer and activator of transcription (STAT)6 phosphorylation] and delayed [granulocyte/macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-β2 (TGF-β2) secretion] responses of airway epithelial cells to IL-4 and IL-13 stimulation and the dependence of these responses on the culture technique employed. As expected, normal human bronchial epithelial cells grown on microporous inserts at an air-liquid interface (ALI) expressed a well-differentiated mucociliary phenotype; in contrast, cells grown on plastic in submerged cultures were poorly differentiated. When stimulated with IL-4 or IL-13, the magnitude and duration of STAT6 phosphorylation under the differing culture conditions were statistically indistinguishable. In contrast, cytokine secretion responses to IL-4 and IL-13 were highly dependent on the culture technique; cells cultured on plastic exhibited significant concentration-dependent increases in GM-CSF and TGF-β2 secretion, whereas cells grown at ALI showed no statistically significant response. These results demonstrate that the coupling between early signal transduction responses to IL-4 and IL-13 and downstream functions such as cytokine secretion may be critically dependent on the cell culture technique employed and the resulting differentiation status of bronchial epithelial cells.

scholarly journals Autocrine Acetylcholine, Induced by IL-17A via NFκB and ERK1/2 Pathway Activation, Promotes MUC5AC and IL-8 Synthesis in Bronchial Epithelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Angela Marina Montalbano ◽  
Giusy Daniela Albano ◽  
Anna Bonanno ◽  
Loredana Riccobono ◽  
Caterina Di Sano ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Anticholinergic Drug ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Choline Uptake ◽  
Airway Epithelial ◽  
Related Activity ◽  
Bronchial Epithelial ◽  
Pathway Activation

IL-17A is overexpressed in the lung during acute neutrophilic inflammation. Acetylcholine (ACh) increases IL-8 and Muc5AC production in airway epithelial cells. We aimed to characterize the involvement of nonneuronal components of cholinergic system on IL-8 and Muc5AC production in bronchial epithelial cells stimulated with IL-17A. Bronchial epithelial cells were stimulated with recombinant human IL-17A (rhIL-17A) to evaluate the ChAT expression, the ACh binding and production, the IL-8 release, and the Muc5AC production. Furthermore, the effectiveness of PD098,059 (inhibitor of MAPKK activation), Bay11-7082 (inhibitor of IkBαphosphorylation), Hemicholinium-3 (HCh-3) (choline uptake blocker), and Tiotropium bromide (Spiriva®) (anticholinergic drug) was tested in ourin vitromodel. We showed that rhIL-17A increased the expression of ChAT, the levels of ACh binding and production, and the IL-8 and Muc5AC production in stimulated bronchial epithelial cells compared with untreated cells. The pretreatment of the cells with PD098,059 and Bay11-7082 decreased the ChAT expression and the ACh production/binding, while HCh-3 and Tiotropium decreased the IL-8 and Muc5AC synthesis in bronchial epithelial cells stimulated with rhIL-17A. IL-17A is involved in the IL-8 and Muc5AC production promoting, via NFκB and ERK1/2 pathway activation, the synthesis of ChAT, and the related activity of autocrine ACh in bronchial epithelial cells.

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