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.

Decreased expression of uteroglobin-related protein 1 in inflamed mouse airways is mediated by IL-9

2004 ◽  
Vol 287 (6) ◽  
pp. L1193-L1198 ◽  
Author(s):  
Yoshihiko Chiba ◽  
Takashi Kusakabe ◽  
Shioko Kimura
Keyword(s):  
Epithelial Cells ◽  
Airway Inflammation ◽  
Inverse Correlation ◽  
Immunohistochemical Analysis ◽  
Secretory Protein ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Airway Epithelial ◽  
Related Protein ◽  
Interleukin 9

Uteroglobin-related protein 1 (UGRP1) is a secretory protein, highly expressed in epithelial cells of airways. Although an involvement of UGRP1 in the pathogenesis of asthma has been suggested, its function in airways remains unclear. In the present study, a relationship between airway inflammation, UGRP1 expression, and interleukin-9 (IL-9), an asthma candidate gene, was evaluated by using a murine model of allergic bronchial asthma. A severe airway inflammation accompanied by airway eosinophilia and elevation of IL-9 in bronchoalveolar lavage (BAL) fluids was observed after ovalbumin (OVA) challenge to OVA-sensitized mice. In this animal model of airway inflammation, lung Ugrp1 mRNA expression was greatly decreased compared with control mice. A significant inverse correlation between lung Ugrp1 mRNA levels and IL-9 levels in BAL fluid was demonstrated by regression analysis ( r = 0.616, P = 0.023). Immunohistochemical analysis revealed a distinct localization of UGRP1 in airway epithelial cells of control mice, whereas UGRP1 staining was patchy and faint in inflamed airways. Intranasal administration of IL-9 to naive mice decreased the level of Ugrp1 expression in lungs. These findings suggest that UGRP1 is downregulated in inflamed airways, such as allergic asthmatics, and IL-9 might be an important mediator for modulating UGRP1 expression.

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.

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 Dysregulated Notch Signaling in the Airway Epithelium of Children with Wheeze

2021 ◽  
Vol 11 (12) ◽  
pp. 1323
Author(s):  
Thomas Iosifidis ◽  
Erika N. Sutanto ◽  
Samuel T. Montgomery ◽  
Patricia Agudelo-Romero ◽  
Kevin Looi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Notch Signaling ◽  
Airway Epithelium ◽  
Wound Repair ◽  
Notch Pathway ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Airway Epithelial ◽  
Closure Rate

The airway epithelium of children with wheeze is characterized by defective repair that contributes to disease pathobiology. Dysregulation of developmental processes controlled by Notch has been identified in chronic asthma. However, its role in airway epithelial cells of young children with wheeze, particularly during repair, is yet to be determined. We hypothesized that Notch is dysregulated in primary airway epithelial cells (pAEC) of children with wheeze contributing to defective repair. This study investigated transcriptional and protein expression and function of Notch in pAEC isolated from children with and without wheeze. Primary AEC of children with and without wheeze were found to express all known Notch receptors and ligands, although pAEC from children with wheeze expressed significantly lower NOTCH2 (10-fold, p = 0.004) and higher JAG1 (3.5-fold, p = 0.002) mRNA levels. These dysregulations were maintained in vitro and cultures from children with wheeze displayed altered kinetics of both NOTCH2 and JAG1 expression during repair. Following Notch signaling inhibition, pAEC from children without wheeze failed to repair (wound closure rate of 76.9 ± 3.2%). Overexpression of NOTCH2 in pAEC from children with wheeze failed to rescue epithelial repair following wounding. This study illustrates the involvement of the Notch pathway in airway epithelial wound repair in health and disease, where its dysregulation may contribute to asthma development.

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.

scholarly journals Airway Surface Liquid Osmolality Measured Using Fluorophore-Encapsulated Liposomes

2001 ◽  
Vol 117 (5) ◽  
pp. 423-430 ◽  
Author(s):  
Sujatha Jayaraman ◽  
Yuanlin Song ◽  
A.S. Verkman
Keyword(s):  
Epithelial Cells ◽  
Water Loss ◽  
Airway Epithelial Cells ◽  
Evaporative Water Loss ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Evaporative Water ◽  
Dry Air ◽  
Surface Liquid ◽  
Sulforhodamine 101

The airway surface liquid (ASL) is the thin layer of fluid coating the luminal surface of airway epithelial cells at an air interface. Its composition and osmolality are thought to be important in normal airway physiology and in airway diseases such as asthma and cystic fibrosis. The determinants of ASL osmolality include epithelial cell solute and water transport properties, evaporative water loss, and the composition of secreted fluids. We developed a noninvasive approach to measure ASL osmolality using osmotically sensitive 400-nm-diam liposomes composed of phosphatidylcholine/cholesterol/polyethylene glycol-phosphatidylcholine (1:0.3:0.08 molar ratio). Calcein was encapsulated in the liposomes at self-quenching concentrations (30 mM) as a volume-sensitive marker, together with sulforhodamine 101 (2 mM) as a volume-insensitive reference. Liposome calcein/sulforhodamine 101 fluorescence ratios responded rapidly (&lt;0.2 s) and stably to changes in solution osmolality. ASL osmolality was determined from calcein/sulforhodamine 101 fluorescence ratios after addition of microliter quantities of liposome suspensions to the ASL. In bovine airway epithelial cells cultured on porous supports at an air–liquid interface, ASL thickness (by confocal microscopy) was 22 μm and osmolality was 325 ± 12 mOsm. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 55 μm and osmolality was 330 ± 36 mOsm. ASL osmolality was not affected by pharmacological inhibition of CFTR in airway cell cultures or by genetic deletion of CFTR in knockout mice. ASL osmolality could be increased substantially to &gt;400 mOsm by exposure of the epithelium to dry air; the data were modeled mathematically using measured rates of osmosis and evaporative water loss. These results establish a ratio imaging method to map osmolality in biological compartments. ASL fluid is approximately isosmolar under normal physiological conditions, but can become hyperosmolar when exposed to dry air, which may induce cough and airway reactivity in some patients.

The chemokine receptor CXCR3 and its splice variant are expressed in human airway epithelial cells

2004 ◽  
Vol 287 (3) ◽  
pp. L584-L591 ◽  
Author(s):  
Steven G. Kelsen ◽  
Mark O. Aksoy ◽  
Yi Yang ◽  
Syed Shahabuddin ◽  
Judith Litvin ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Inflammation ◽  
Chemokine Receptor ◽  
Splice Variant ◽  
Constitutive Expression ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Airway Epithelial ◽  
Human Airway ◽  
Human Airway Epithelial Cells

Activation of the chemokine receptor CXCR3 by its cognate ligands induces several differentiated cellular responses important to the growth and migration of a variety of hematopoietic and structural cells. In the human respiratory tract, human airway epithelial cells (HAEC) release the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11. Simultaneous expression of CXCR3 by HAEC would have important implications for the processes of airway inflammation and repair. Accordingly, in the present study we sought to determine whether HAEC also express the classic CXCR3 chemokine receptor CXCR3-A and its splice variant CXCR3-B and hence may respond in autocrine fashion to its ligands. We found that cultured HAEC (16-HBE and tracheocytes) constitutively expressed CXCR3 mRNA and protein. CXCR3 mRNA levels assessed by expression array were ∼35% of β-actin expression. In contrast, CCR3, CCR4, CCR5, CCR8, and CX3CR1 were <5% β-actin. Both CXCR3-A and -B were expressed. Furthermore, tracheocytes freshly harvested by bronchoscopy stained positively for CXCR3 by immunofluorescence microscopy, and 68% of cytokeratin-positive tracheocytes (i.e., the epithelial cell population) were positive for CXCR3 by flow cytometry. In 16-HBE cells, CXCR3 receptor density was ∼78,000 receptors/cell when assessed by competitive displacement of 125I-labeled IP-10/CXCL10. Finally, CXCR3 ligands induced chemotactic responses and actin reorganization in 16-HBE cells. These findings indicate constitutive expression by HAEC of a functional CXC chemokine receptor, CXCR3. Our data suggest the possibility that autocrine activation of CXCR3 expressed by HAEC may contribute to airway inflammation and remodeling in obstructive lung disease by regulating HAEC migration.

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.

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