scholarly journals Regulation of MUC5AC mucin secretion and airway surface liquid metabolism by IL-1β in human bronchial epithelia

2004 ◽  
Vol 286 (2) ◽  
pp. L320-L330 ◽  
Author(s):  
Thomas Gray ◽  
Ray Coakley ◽  
Andrew Hirsh ◽  
David Thornton ◽  
S. Kirkham ◽  
...  
Keyword(s):  
Defense Mechanism ◽  
Early Response ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Mucin Production ◽  
Inflammatory Stimuli ◽  
Surface Liquid

Mucociliary transport in the airways significantly depends on the liquid and mucin components of the airway surface liquid (ASL). The regulation of ASL water and mucin content during pathological conditions is not well understood. We hypothesized that airway epithelial mucin production and liquid transport are regulated in response to inflammatory stimuli and tested this hypothesis by investigating the effects of the pleiotropic, early-response cytokine, IL-1β, on cultured primary human bronchial epithelial and second-passage, normal human tracheo-bronchial epithelial (NHTBE) cell cultures. Fully differentiated NHTBE cultures secreted two major airway mucins, MUC5AC and MUC5B. IL-1β, in a dose- and time-dependent manner, increased the secretion of MUC5AC, but not MUC5B. MUC5AC mRNA levels were only transiently increased at 1 and 4 h after the start of IL-1β treatment and returned to control levels thereafter, even though MUC5AC mucin production remained elevated for at least 72 h. Synchronous with elevated MUC5AC secretion, ASL volume increased, its percentage of solid was reduced, and the pH/[[Formula: see text]] of the ASL was elevated. ASL volume changes reflected altered ion transport, including an upregulation of Cl- secretory currents (via CFTR and Ca2+-activated Cl- conductance) and an inhibition of epithelial sodium channel (ENaC)-mediated absorptive Na+ currents. IL-1β increased CFTR mRNA levels without affecting those for ENaC subunits. The synchronous regulation of ASL mucin and liquid metabolism triggered by IL-1β may be an important defense mechanism of the airway epithelium to enhance mucociliary clearance during airway inflammation.

Effects of dexamethasone on Muc5ac mucin production by primary airway goblet cells

2005 ◽  
Vol 288 (1) ◽  
pp. L52-L60 ◽  
Author(s):  
Wenju Lu ◽  
Erik P. Lillehoj ◽  
K. Chul Kim
Keyword(s):  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Mucus Production ◽  
Mucin Production ◽  
Proinflammatory Mediators ◽  
A Cell ◽  
The Stability

Mucus hypersecretion associated with airway inflammation is reduced by glucocorticoids. Two mechanisms of glucocorticoid-mediated inhibition of mucus production have been proposed, direct inhibition of mucus production by airway epithelial cells and indirectly through inhibition of proinflammatory mediators that stimulate mucus production. In this study, we examined the effect of dexamethasone (DEX) on mRNA expression and synthesis of MUC5AC by A549 human lung adenocarcinoma cells as well as Muc5ac and total high-molecular-weight (HMW) mucins by primary rat tracheal surface epithelial (RTSE) cells. Our results showed that in primary RTSE cells, DEX 1) dose dependently suppressed Muc5ac mRNA levels, but the levels of cellular Muc5ac protein and HMW mucins were unaffected; 2) did not affect constitutive or UTP-stimulated mucin secretion; 3) enhanced the translation of Muc5ac; and 4) increased the stability of intracellular Muc5ac protein by a mechanism other than the inhibition of the proteasomal degradation. In A549 cells, however, DEX suppressed both MUC5AC mRNA levels and MUC5AC protein secretion in a dose-dependent manner. We conclude that whereas DEX inhibits the levels of Muc5ac mRNA in primary RTSE cells, the levels of Muc5ac protein remain unchanged as a consequence of increases in both translation and protein stability. Interestingly, some of the effects of DEX were opposite in a cell line.

scholarly journals Transport properties in CFTR−/− knockout piglets suggest normal airway surface liquid pH and enhanced amiloride-sensitive Na+ absorption

2020 ◽  
Vol 472 (10) ◽  
pp. 1507-1519 ◽  
Author(s):  
Roberta Benedetto ◽  
Raquel Centeio ◽  
Jiraporn Ousingsawat ◽  
Rainer Schreiber ◽  
Melanie Janda ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transport Properties ◽  
Airway Epithelial Cells ◽  
Small Contribution ◽  
Mrna Levels ◽  
Lung Pathology ◽  
Airway Epithelial ◽  
Contrast Enhanced ◽  
Surface Liquid ◽  
A Minor

Abstract Previous analysis of CFTR-knockout (CFTR−/−) in piglets has provided important insights into the pathology of cystic fibrosis. However, controversies exist as to the true contribution of CFTR to the pH balance in airways and intestine. We therefore compared ion transport properties in newborn wild-type (CFTR+/+) and CFTR-knockout (CFTR−/− piglets). Tracheas of CFTR−/− piglets demonstrated typical cartilage malformations and muscle cell bundles. CFTR−/− airway epithelial cells showed enhanced lipid peroxidation, suggesting inflammation early in life. CFTR was mainly expressed in airway submucosal glands and was absent in lungs of CFTR−/− piglets, while expression of TMEM16A was uncompromised. mRNA levels for TMEM16A, TMEM16F, and αβγENaC were unchanged in CFTR−/− airways, while mRNA for SLC26A9 appeared reduced. CFTR was undetectable in epithelial cells of CFTR−/− airways and intestine. Small intestinal epithelium of CFTR−/− piglets showed mucus accumulation. Secretion of both electrolytes and mucus was activated by stimulation with prostaglandin E2 and ATP in the intestine of CFTR+/+, but not of CFTR−/− animals. pH was measured inside small bronchi using a pH microelectrode and revealed no difference between CFTR+/+ and CFTR−/− piglets. Intracellular pH in porcine airway epithelial cells revealed only a small contribution of CFTR to bicarbonate secretion, which was absent in cells from CFTR−/− piglets. In contrast to earlier reports, our data suggest a minor impact of CFTR on ASL pH. In contrast, enhanced amiloride-sensitive Na+ absorption may contribute to lung pathology in CFTR−/− piglets, along with a compromised CFTR- and TMEM16A-dependent Cl− transport.

Erythromycin increases bactericidal activity of surface liquid in human airway epithelial cells

2005 ◽  
Vol 289 (4) ◽  
pp. L565-L573 ◽  
Author(s):  
Kota Ishizawa ◽  
Tomoko Suzuki ◽  
Mutsuo Yamaya ◽  
Yu Xia Jia ◽  
Seiichi Kobayashi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bactericidal Activity ◽  
Culture Medium ◽  
Airway Epithelial Cells ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Tracheal Epithelial Cells ◽  
Tracheal Epithelial ◽  
Surface Liquid ◽  
Number Of Bacteria

Macrolide antibiotics have clinical benefits in patients with diffuse panbronchiolitis and in patients with cystic fibrosis. Although many mechanisms have been proposed, the precise mechanisms are still uncertain. We examined the effects of erythromycin on bactericidal activity of airway surface liquid secreted by cultured human tracheal epithelial cells. Airway surface liquid was collected by washing the surface of human tracheal epithelial cells with a sodium solution (40 meq/l). Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa were incubated with airway surface liquid, and the number of surviving bacteria was examined. The number of bacteria in airway surface liquid from the cells cultured in medium alone was significantly lower than that in the sodium solution. Furthermore, the number of bacteria in airway surface liquid from the cells treated with erythromycin was significantly lower than that in airway surface liquid from the cells treated with solvent alone. The production of mRNA and protein of human β-defensin-1 and human β-defensin-2 was significantly increased by erythromycin. Bactericidal activity of airway surface liquid was observed at low concentrations (40 meq/l) of sodium but not at higher concentrations (≥80 meq/l). Airway surface liquid did not contain significant amounts of antibiotics supplemented in the culture medium. Erythromycin at the levels in airway surface liquid and in culture medium did not inhibit bacterial growth. These results suggest that erythromycin may increase bactericidal activity of airway surface liquid in human airway epithelial cells through human β-defensins production and reduce susceptibility of the airway to bacterial infection.

scholarly journals Naringenin Regulates Lipopolysaccharide-Induced Abnormal Airway Surface Liquid Secretion

2021 ◽  
Vol 16 (9) ◽  
pp. 1934578X2110403
Author(s):  
Rui Shi ◽  
Min-Yi Guan ◽  
Wei-Yang Fan ◽  
Pei-Bo Li ◽  
Zhong-Yi Yang ◽  
...  
Keyword(s):  
Total Protein ◽  
Cultured Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Total Protein Content ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Aquaporin 5 ◽  
Factors Affecting ◽  
Aqp5 Expression ◽  
Surface Liquid

Airway surface liquid (ASL) is one of the key factors affecting the respiratory system's physiological function. Abnormal ASL secretion can increase the incidence of various respiratory diseases. Lipopolysaccharide (LPS) stimulation can damage the airway epithelial barrier, affect the concentration of ASL contents, and down-regulate ion channel expression, which in turn causes abnormal ASL secretion. Naringenin, which exists in many Citrus foods, has the ability to promote airway surface liquid secretion. This work is designed to investigate the regulatory mechanism of naringenin on LPS-induced abnormal ASL secretion. The effects of naringenin and LPS on the viability of Calu-3 cells were measured by CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS). ASL secretion volume was measured by a micropipette on air–liquid interface cultured cells. The concentration of Cl−, Na+, lysozyme, and total protein in ASL were respectively measured by assay kits. The mRNA expressions were determined by quantitative real-time polymerase chain reaction, and proteins were measured by enzyme-linked immunosorbent assay. The results indicated that LPS could affect ASL secretion and regulate cystic fibrosis transmembrane conductance regulator (CFTR), aquaporin 1 (AQP1) and aquaporin 5 (AQP5) expression. Naringenin had the ability to regulate the ASL secretion by increasing secretion volume, and Cl− and Na+ concentrations, reducing lysozyme and total protein content, and regulating CFTR, AQP1, and AQP5 expression. This study indicated that naringenin had regulating effects to attenuate LPS-induced abnormal ASL secretion.

scholarly journals Inhibition of ATP hydrolysis restores airway surface liquid production in cystic fibrosis airway epithelia

2020 ◽  
Vol 318 (2) ◽  
pp. L356-L365 ◽  
Author(s):  
Catharina van Heusden ◽  
Brian Button ◽  
Wayne H. Anderson ◽  
Agathe Ceppe ◽  
Lisa C. Morton ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Steady State ◽  
Atp Hydrolysis ◽  
Fluid Secretion ◽  
Pathological Feature ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Atp Levels ◽  
Surface Liquid

Airway surface dehydration is a pathological feature of cystic fibrosis (CF) lung disease. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR), a cyclic AMP-regulated Cl− channel controlled in part by the adenosine A2B receptor. An alternative CFTR-independent mechanism of fluid secretion is regulated by ATP via the P2Y2 receptor (P2Y2R) that activates Ca2+-regulated Cl− channels (CaCC/TMEM16) and inhibits Na+ absorption. However, due to rapid ATP hydrolysis, steady-state ATP levels in CF airway surface liquid (ASL) are inadequate to maintain P2Y2R-mediated fluid secretion. Therefore, inhibiting airway epithelial ecto-ATPases to increase ASL ATP levels constitutes a strategy to restore airway surface hydration in CF. Using [γ32P]ATP as radiotracer, we assessed the effect of a series of ATPase inhibitory compounds on the stability of physiologically occurring ATP concentrations. We identified the polyoxometalate [Co4(H2O)2(PW9O34)2]10− (POM-5) as the most potent and effective ecto-ATPase inhibitor in CF airway epithelial cells. POM-5 caused long-lasting inhibition of ATP hydrolysis in airway epithelia, which was reversible upon removal of the inhibitor. Importantly, POM-5 markedly enhanced steady-state levels of released ATP, promoting increased ASL volume in CF cell surfaces. These results provide proof of concept for ecto-ATPase inhibitors as therapeutic agents to restore hydration of CF airway surfaces. As a test of this notion, cell-free sputum supernatants from CF subjects were studied and found to have abnormally elevated ATPase activity, which was markedly inhibited by POM-5.

scholarly journals TNFα and IL-17 alkalinize airway surface liquid through CFTR and pendrin

2020 ◽  
Vol 319 (2) ◽  
pp. C331-C344 ◽  
Author(s):  
Tayyab Rehman ◽  
Ian M. Thornell ◽  
Alejandro A. Pezzulo ◽  
Andrew L. Thurman ◽  
Guillermo S. Romano Ibarra ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Defense Mechanism ◽  
Primary Cultures ◽  
Secretory Cells ◽  
Airway Surface Liquid ◽  
Airway Epithelia ◽  
Airway Diseases ◽  
Key Factor ◽  
Surface Liquid ◽  
And Function

The pH of airway surface liquid (ASL) is a key factor that determines respiratory host defense; ASL acidification impairs and alkalinization enhances key defense mechanisms. Under healthy conditions, airway epithelia secrete base ([Formula: see text]) and acid (H+) to control ASL pH (pHASL). Neutrophil-predominant inflammation is a hallmark of several airway diseases, and TNFα and IL-17 are key drivers. However, how these cytokines perturb pHASL regulation is uncertain. In primary cultures of differentiated human airway epithelia, TNFα decreased and IL-17 did not change pHASL. However, the combination (TNFα+IL-17) markedly increased pHASL by increasing [Formula: see text] secretion. TNFα+IL-17 increased expression and function of two apical [Formula: see text] transporters, CFTR anion channels and pendrin Cl−/[Formula: see text] exchangers. Both were required for maximal alkalinization. TNFα+IL-17 induced pendrin expression primarily in secretory cells where it was coexpressed with CFTR. Interestingly, significant pendrin expression was not detected in CFTR-rich ionocytes. These results indicate that TNFα+IL-17 stimulate [Formula: see text] secretion via CFTR and pendrin to alkalinize ASL, which may represent an important defense mechanism in inflamed airways.

scholarly journals Allium porrum Extract Decreases Effector Cell Degranulation and Modulates Airway Epithelial Cell Function

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1303 ◽  
Author(s):  
Sara Benedé ◽  
Ana Gradillas ◽  
Mayte Villalba ◽  
Eva Batanero
Keyword(s):  
Cell Function ◽  
Total Phenolic ◽  
Allium Porrum ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Allergy Treatment ◽  
Lower Permeability ◽  
Anti Inflammatory ◽  
High Concentrations

Allium genus plants, such as leek (Allium porrum), are rich sources of anti-inflammatory and anti-oxidant secondary metabolites; this is of interest because it demonstrates their suitability as pharmacological alternatives for inflammatory processes, including allergy treatment. The composition of methanolic leek extract (LE) was analyzed by GC–MS and LC–IT/MS, and the total phenolic content and antioxidant capacity were quantified by colorimetric methods. Its pharmacological potential was analyzed in human bronchial epithelial Calu-3 cells, human mast cells LAD2, and humanized rat basophiles RBL-2H3. LE exhibited a cytotoxic effect on Calu-3 cells and HumRBL-2H3 cells only at high concentrations and in a dose-dependent manner. Moreover, LE decreased the degranulation of LAD2 and HumRBL-2H3 cells. LE treatment also significantly prevented alterations in transepithelial electrical resistance values and mRNA levels of glutathione-S-transferase (GST), c-Jun, and NFκB after treatment with H2O2 in ALI-cultured Calu-3 cells. Finally, ALI-cultured Calu-3 cells treated with LE showed lower permeability to Ole e 1 compared to untreated cells. A reduction in IL-6 secretion in ALI-cultured Calu-3 cells treated with LE was also observed. In summary, the results obtained in this work suggest that A. porrum extract may have potential anti-allergic effects due to its antioxidant and anti-inflammatory properties. This study provides several important insights into how LE can protect against allergy.

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.

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