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Sample records for airway surface epithelial

  1. Regulation of the epithelial Na+ channel and airway surface liquid volume by serine proteases

    PubMed Central

    Gaillard, Erol A.; Kota, Pradeep; Gentzsch, Martina; Dokholyan, Nikolay V.; Stutts, M. Jackson

    2010-01-01

    Mammalian airways are protected from infection by a thin film of airway surface liquid (ASL) which covers airway epithelial surfaces and acts as a lubricant to keep mucus from adhering to the epithelial surface. Precise regulation of ASL volume is essential for efficient mucus clearance and too great a reduction in ASL volume causes mucus dehydration and mucus stasis which contributes to chronic airway infection. The epithelial Na+ channel (ENaC) is the rate-limiting step that governs Na+ absorption in the airways. Recent in vitro and in vivo data have demonstrated that ENaC is a critical determinant of ASL volume and hence mucus clearance. ENaC must be cleaved by either intracellular furin-type proteases or extracellular serine proteases to be active and conduct Na+, and this process can be inhibited by protease inhibitors. ENaC can be regulated by multiple pathways, and once proteolytically cleaved ENaC may then be inhibited by intracellular second messengers such as cAMP and PIP2. In the airways, however, regulation of ENaC by proteases seems to be the predominant mode of regulation since knockdown of either endogenous serine proteases such as prostasin, or inhibitors of ENaC proteolysis such as SPLUNC1, has large effects on ENaC activity in airway epithelia. In this review, we shall discuss how ENaC is proteolytically cleaved, how this process can regulate ASL volume, and how its failure to operate correctly may contribute to chronic airway disease. PMID:20401730

  2. Epithelial hyperplasia, airways

    Cancer.gov

    Number of respiratory epithelial cells is increased diffusely or focally. Frequently luminal protrusions are observed, sometimes forming papillae. Mucous (goblet) cell metaplastic hyperplasia is a variant, in which the respiratory epithelium of conducting airways is replaced by mucous cells either as a single or a pseudostratified layer.

  3. Mechanisms of surface-tension-induced epithelial cell damage in a model of pulmonary airway reopening.

    PubMed

    Bilek, Anastacia M; Dee, Kay C; Gaver, Donald P

    2003-02-01

    Airway collapse and reopening due to mechanical ventilation exerts mechanical stress on airway walls and injures surfactant-compromised lungs. The reopening of a collapsed airway was modeled experimentally and computationally by the progression of a semi-infinite bubble in a narrow fluid-occluded channel. The extent of injury caused by bubble progression to pulmonary epithelial cells lining the channel was evaluated. Counterintuitively, cell damage increased with decreasing opening velocity. The presence of pulmonary surfactant, Infasurf, completely abated the injury. These results support the hypotheses that mechanical stresses associated with airway reopening injure pulmonary epithelial cells and that pulmonary surfactant protects the epithelium from this injury. Computational simulations identified the magnitudes of components of the stress cycle associated with airway reopening (shear stress, pressure, shear stress gradient, or pressure gradient) that may be injurious to the epithelial cells. By comparing these magnitudes to the observed damage, we conclude that the steep pressure gradient near the bubble front was the most likely cause of the observed cellular damage. PMID:12433851

  4. The Epithelial Anion Transporter Pendrin Is Induced by Allergy and Rhinovirus Infection, Regulates Airway Surface Liquid, and Increases Airway Reactivity and Inflammation in an Asthma Model1

    PubMed Central

    Nakagami, Yasuhiro; Favoreto, Silvio; Zhen, Guohua; Park, Sung-Woo; Nguyenvu, Louis T.; Kuperman, Douglas A.; Dolganov, Gregory M.; Huang, Xiaozhu; Boushey, Homer A.; Avila, Pedro C.; Erle, David J.

    2008-01-01

    Asthma exacerbations can be triggered by viral infections or allergens. The Th2 cytokines IL-13 and IL-4 are produced during allergic responses and cause increases in airway epithelial cell mucus, electrolyte and water secretion into the airway surface liquid (ASL). Since ASL dehydration can cause airway inflammation and obstruction, ion transporters could play a role in pathogenesis of asthma exacerbations. We previously reported that expression of the epithelial cell anion transporter pendrin is markedly increased in response to IL-13. Here we show that pendrin plays a role in allergic airway disease and in regulation of ASL thickness. Pendrin-deficient mice had less allergen-induced airway hyperreactivity and inflammation than control mice although other aspects of the Th2 response were preserved. In cultures of IL-13-stimulated mouse tracheal epithelial cells, pendrin deficiency caused an increase in ASL thickness, suggesting that reductions in allergen-induced hyperreactivity and inflammation in pendrin-deficient mice result from improved ASL hydration. To determine whether pendrin might also play a role in virus-induced exacerbations of asthma, we measured pendrin mRNA expression in human subjects with naturally occurring common colds caused by rhinovirus and found a 4.9-fold-increase in mean expression during colds. Studies of cultured human bronchial epithelial cells indicated that this increase could be explained by the combined effects of rhinovirus and IFN-γ, a Th1 cytokine induced during virus infection. We conclude that pendrin regulates ASL thickness and may be an important contributor to asthma exacerbations induced by viral infections or allergens. PMID:18641360

  5. Effect of modifying quantum dot surface charge on airway epithelial cell uptake in vitro

    PubMed Central

    Chau, Eric; Galloway, Justin F.; Nelson, Antoinette; Breysse, Patrick N.; Wirtz, Denis; Searson, Peter C.

    2012-01-01

    The respiratory system is one of the portals of entry into the body, and hence inhalation of engineered nanomaterials is an important route of exposure. The broad range of physicochemical properties that influence biological responses necessitate the systematic study to contribute to understanding occupational exposure. Here, we report on the influence of nanoparticle charge and dose on human airway epithelial cells, and show that this platform can be used to evaluate consequences of exposure to engineered nanomaterials. PMID:22783847

  6. Airway epithelial cell responses to ozone injury

    SciTech Connect

    Leikauf, G.D.; Simpson, L.G.; Zhao, Qiyu

    1995-03-01

    The airway epithelial cell is an important target in ozone injury. Once activated, the airway epithelium responds in three phases. The initial, or immediate phase, involves activation of constitutive cells, often through direct covalent interactions including the formation of secondary ozonolysis products-hydroxyhydroperoxides, aldehydes, and hydrogen peroxide. Recently, we found hydroxyhydroperoxides to be potent agonists; of bioactive eicosanoid formation by human airway epithelial cells in culture. Other probable immediate events include activation and inactivation of enzymes present on the epithelial surface (e.g., neutral endopeptidase). During the next 2 to 24 hr, or early phase, epithelial cells respond by synthesis and release of chemotactic factors, including chemokines-macrophage inflammatory protein-2, RANTES, and interleukin-8. Infiltrating leukocytes during this period also release elastase, an important agonist of epithelial cell mucus secretion and additional chemokine formation. The third (late) phase of ozone injury is characterized by eosinophil or monocyte infiltration. Cytokine expression leads to alteration of structural protein synthesis, with increases in fibronectin evident by in situ hybridization. Synthesis of epithelial antiproteases, e.g., secretary leukocyte protease inhibitor, may also increase locally 24 to 48 hr after elastase concentrations become excessive. Thus, the epithelium is not merely a passive barrier to ozone injury but has a dynamic role in directing the migration, activating, and then counteracting inflammatory cells. Through these complex interactions, epithelial cells can be viewed as the initiators (alpha) and the receptors (omega) of ozone-induced airway disease. 51 refs., 2 figs., 3 tabs.

  7. S-nitrosothiols regulate cell-surface pH buffering by airway epithelial cells during the human immune response to rhinovirus.

    PubMed

    Carraro, Silvia; Doherty, Joseph; Zaman, Khalequz; Gainov, Iain; Turner, Ronald; Vaughan, John; Hunt, John F; Márquez, Javier; Gaston, Benjamin

    2006-05-01

    Human rhinovirus infection is a common trigger for asthma exacerbations. Asthma exacerbations and rhinovirus infections are both associated with markedly decreased pH and ammonium levels in exhaled breath condensates. This observation is thought to be related, in part, to decreased activity of airway epithelial glutaminase. We studied whether direct rhinovirus infection and/or the host immune response to the infection decreased airway epithelial cell surface pH in vitro. Interferon-gamma and tumor necrosis factor-alpha, but not direct rhinovirus infection, decreased pH, an effect partly associated with decreased ammonium concentrations. This effect was 1) prevented by nitric oxide synthase inhibition; 2) independent of cyclic GMP; 3) associated with an increase in endogenous airway epithelial cell S-nitrosothiol concentration; 4) mimicked by the exogenous S-nitrosothiol, S-nitroso-N-acetyl cysteine; and 5) independent of glutaminase expression and activity. We then confirmed that decreased epithelial pH inhibits human rhinovirus replication in airway epithelial cells. These data suggest that a nitric oxide synthase-dependent host response to viral infection mediated by S-nitrosothiols, rather than direct infection itself, plays a role in decreased airway surface pH during human rhinovirus infection. This host immune response may serve to protect the lower airways from direct infection in the normal host. In patients with asthma, however, this fall in pH could be associated with the increased mucus production, augmented inflammatory cell degranulation, bronchoconstriction, and cough characteristic of an asthma exacerbation. PMID:16603595

  8. CX3CR1 is an important surface molecule for respiratory syncytial virus infection in human airway epithelial cells

    PubMed Central

    Chirkova, Tatiana; Lin, Songbai; Oomens, Antonius G. P.; Gaston, Kelsey A.; Boyoglu-Barnum, Seyhan; Meng, Jia; Stobart, Christopher C.; Cotton, Calvin U.; Hartert, Tina V.; Moore, Martin L.; Ziady, Assem G.

    2015-01-01

    Respiratory syncytial virus (RSV) is a major cause of severe pneumonia and bronchiolitis in infants and young children, and causes disease throughout life. Understanding the biology of infection, including virus binding to the cell surface, should help develop antiviral drugs or vaccines. The RSV F and G glycoproteins bind cell surface heparin sulfate proteoglycans (HSPGs) through heparin-binding domains. The G protein also has a CX3C chemokine motif which binds to the fractalkine receptor CX3CR1. G protein binding to CX3CR1 is not important for infection of immortalized cell lines, but reportedly is so for primary human airway epithelial cells (HAECs), the primary site for human infection. We studied the role of CX3CR1 in RSV infection with CX3CR1-transfected cell lines and HAECs with variable percentages of CX3CR1-expressing cells, and the effect of anti-CX3CR1 antibodies or a mutation in the RSV CX3C motif. Immortalized cells lacking HSPGs had low RSV binding and infection, which was increased markedly by CX3CR1 transfection. CX3CR1 was expressed primarily on ciliated cells, and ∼50 % of RSV-infected cells in HAECs were CX3CR1+. HAECs with more CX3CR1-expressing cells had a proportional increase in RSV infection. Blocking G binding to CX3CR1 with anti-CX3CR1 antibody or a mutation in the CX3C motif significantly decreased RSV infection in HAECs. The kinetics of cytokine production suggested that the RSV/CX3CR1 interaction induced RANTES (regulated on activation normal T-cell expressed and secreted protein), IL-8 and fractalkine production, whilst it downregulated IL-15, IL1-RA and monocyte chemotactic protein-1. Thus, the RSV G protein/CX3CR1 interaction is likely important in infection and infection-induced responses of the airway epithelium, the primary site of human infection. PMID:26297201

  9. The buffer capacity of airway epithelial secretions

    PubMed Central

    Kim, Dusik; Liao, Jie; Hanrahan, John W.

    2014-01-01

    The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF). The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 μl) volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO−3 is the major buffer. Peak buffer capacity (β) increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR)-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO−3 secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO−3 secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions. PMID:24917822

  10. Fungal glycan interactions with epithelial cells in allergic airway disease

    PubMed Central

    Roy, René M.; Klein, Bruce S.

    2014-01-01

    Human exposure to fungi results in a wide range of health outcomes, from invasive disease or allergy to immune tolerance. Inhaled fungi contact airway epithelial cells as an early event, and this host:fungal interaction can shape the eventual immunological outcome. Emerging evidence points to exposure to fungal cell wall carbohydrates in the development of allergic airway disease. Herein, we describe determinants of fungal allergenicity, and review the responses of airway epithelial cells to fungal carbohydrates. A greater understanding of the recognition of and response to fungal carbohydrates by airway epithelial cells may lead to the development of targeted therapies that ameliorate allergic airway disease. PMID:23602359

  11. Detonation Nanodiamond Toxicity in Human Airway Epithelial Cells Is Modulated by Air Oxidation

    EPA Science Inventory

    Detonational nanodiamonds (DND), a nanomaterial with an increasing range of industrial and biomedical applications, have previously been shown to induce a pro-inflammatory response in cultured human airway epithelial cells (HAEC). We now show that surface modifications induced by...

  12. Control of local immunity by airway epithelial cells.

    PubMed

    Weitnauer, M; Mijošek, V; Dalpke, A H

    2016-03-01

    The lung is ventilated by thousand liters of air per day. Inevitably, the respiratory system comes into contact with airborne microbial compounds, most of them harmless contaminants. Airway epithelial cells are known to have innate sensor functions, thus being able to detect microbial danger. To avoid chronic inflammation, the pulmonary system has developed specific means to control local immune responses. Even though airway epithelial cells can act as proinflammatory promoters, we propose that under homeostatic conditions airway epithelial cells are important modulators of immune responses in the lung. In this review, we discuss epithelial cell regulatory functions that control reactivity of professional immune cells within the microenvironment of the airways and how these mechanisms are altered in pulmonary diseases. Regulation by epithelial cells can be divided into two mechanisms: (1) mediators regulate epithelial cells' innate sensitivity in cis and (2) factors are produced that limit reactivity of immune cells in trans. PMID:26627458

  13. Epithelial injury and repair in airways diseases.

    PubMed

    Grainge, Christopher L; Davies, Donna E

    2013-12-01

    Asthma is a common chronic disease characterized by variable respiratory distress with underlying airway inflammation and airflow obstruction. The incidence of asthma has risen inexorably over the past 50 years, suggesting that environmental factors are important in its etiology. All inhaled environmental stimuli interact with the lung at the respiratory epithelium, and it is a testament to the effectiveness of the airway innate defenses that the majority of inhaled substances are cleared without the need to elicit an inflammatory response. However, once this barrier is breached, effective communication with immune and inflammatory cells is required to protect the internal milieu of the lung. In asthma, the respiratory epithelium is known to be structurally and functionally abnormal. Structurally, the epithelium shows evidence of damage and has more mucus-producing cells than normal airways. Functionally, the airway epithelial barrier can be more permeable and more sensitive to oxidants and show a deficient innate immune response to respiratory virus infection compared with that in normal individuals. The potential of a susceptible epithelium and the underlying mesenchyme to create a microenvironment that enables deviation of immune and inflammatory responses to external stimuli may be crucial in the development and progression of asthma. In this review, we consider three important groups of environmental stimuli on the epithelium in asthma: oxidants, such as environmental pollution and acetaminophen; viruses, including rhinovirus; and agents that cause barrier disruption, such as house dust mite allergens. The pathology associated with each stimulus is considered, and potential future treatments arising from research on their effects are presented. PMID:24297122

  14. Applications of mouse airway epithelial cell culture for asthma research.

    PubMed

    Horani, Amjad; Dickinson, John D; Brody, Steven L

    2013-01-01

    Primary airway epithelial cell culture provides a valuable tool for studying cell differentiation, cell-cell interactions, and the role of immune system factors in asthma pathogenesis. In this chapter, we discuss the application of mouse tracheal epithelial cell cultures for the study of asthma biology. A major advantage of this system is the ability to use airway epithelial cells from mice with defined genetic backgrounds. The in vitro proliferation and differentiation of mouse airway epithelial cells uses the air-liquid interface condition to generate well-differentiated epithelia with characteristics of native airways. Protocols are provided for manipulation of differentiation, induction of mucous cell metaplasia, genetic modification, and cell and pathogen coculture. Assays for the assessment of gene expression, responses of cells, and analysis of specific cell subpopulations within the airway epithelium are included. PMID:23943446

  15. Interaction with Epithelial Cells Modifies Airway Macrophage Response to Ozone

    EPA Science Inventory

    The initial innate immune response to ozone (03) in the lung is orchestrated by structural cells, such as epithelial cells, and resident immune cells, such as airway macrophages (Macs). We developed an epithelial cell-Mac coculture model to investigate how epithelial cell-derived...

  16. Regulated Mucin Secretion from Airway Epithelial Cells

    PubMed Central

    Adler, Kenneth B.; Tuvim, Michael J.; Dickey, Burton F.

    2013-01-01

    Secretory epithelial cells of the proximal airways synthesize and secrete gel-forming polymeric mucins. The secreted mucins adsorb water to form mucus that is propelled by neighboring ciliated cells, providing a mobile barrier which removes inhaled particles and pathogens from the lungs. Several features of the intracellular trafficking of mucins make the airway secretory cell an interesting comparator for the cell biology of regulated exocytosis. Polymeric mucins are exceedingly large molecules (up to 3 × 106 Da per monomer) whose folding and initial polymerization in the ER requires the protein disulfide isomerase Agr2. In the Golgi, mucins further polymerize to form chains and possibly branched networks comprising more than 20 monomers. The large size of mucin polymers imposes constraints on their packaging into transport vesicles along the secretory pathway. Sugar side chains account for >70% of the mass of mucins, and their attachment to the protein core by O-glycosylation occurs in the Golgi. Mature polymeric mucins are stored in large secretory granules ∼1 μm in diameter. These are translocated to the apical membrane to be positioned for exocytosis by cooperative interactions among myristoylated alanine-rich C kinase substrate, cysteine string protein, heat shock protein 70, and the cytoskeleton. Mucin granules undergo exocytic fusion with the plasma membrane at a low basal rate and a high stimulated rate. Both rates are mediated by a regulated exocytic mechanism as indicated by phenotypes in both basal and stimulated secretion in mice lacking Munc13-2, a sensor of the second messengers calcium and diacylglycerol (DAG). Basal secretion is induced by low levels of activation of P2Y2 purinergic and A3 adenosine receptors by extracellular ATP released in paracrine fashion and its metabolite adenosine. Stimulated secretion is induced by high levels of the same ligands, and possibly by inflammatory mediators as well. Activated receptors are coupled to

  17. Temporal Monitoring of Differentiated Human Airway Epithelial Cells Using Microfluidics

    PubMed Central

    Blume, Cornelia; Reale, Riccardo; Held, Marie; Millar, Timothy M.; Collins, Jane E.; Davies, Donna E.; Morgan, Hywel; Swindle, Emily J.

    2015-01-01

    The airway epithelium is exposed to a variety of harmful agents during breathing and appropriate cellular responses are essential to maintain tissue homeostasis. Recent evidence has highlighted the contribution of epithelial barrier dysfunction in the development of many chronic respiratory diseases. Despite intense research efforts, the responses of the airway barrier to environmental agents are not fully understood, mainly due to lack of suitable in vitro models that recapitulate the complex in vivo situation accurately. Using an interdisciplinary approach, we describe a novel dynamic 3D in vitro model of the airway epithelium, incorporating fully differentiated primary human airway epithelial cells at the air-liquid interface and a basolateral microfluidic supply of nutrients simulating the interstitial flow observed in vivo. Through combination of the microfluidic culture system with an automated fraction collector the kinetics of cellular responses by the airway epithelium to environmental agents can be analysed at the early phases for the first time and with much higher sensitivity compared to common static in vitro models. Following exposure of primary differentiated epithelial cells to pollen we show that CXCL8/IL–8 release is detectable within the first 2h and peaks at 4–6h under microfluidic conditions, a response which was not observed in conventional static culture conditions. Such a microfluidic culture model is likely to have utility for high resolution temporal profiling of toxicological and pharmacological responses of the airway epithelial barrier, as well as for studies of disease mechanisms. PMID:26436734

  18. Temporal Monitoring of Differentiated Human Airway Epithelial Cells Using Microfluidics.

    PubMed

    Blume, Cornelia; Reale, Riccardo; Held, Marie; Millar, Timothy M; Collins, Jane E; Davies, Donna E; Morgan, Hywel; Swindle, Emily J

    2015-01-01

    The airway epithelium is exposed to a variety of harmful agents during breathing and appropriate cellular responses are essential to maintain tissue homeostasis. Recent evidence has highlighted the contribution of epithelial barrier dysfunction in the development of many chronic respiratory diseases. Despite intense research efforts, the responses of the airway barrier to environmental agents are not fully understood, mainly due to lack of suitable in vitro models that recapitulate the complex in vivo situation accurately. Using an interdisciplinary approach, we describe a novel dynamic 3D in vitro model of the airway epithelium, incorporating fully differentiated primary human airway epithelial cells at the air-liquid interface and a basolateral microfluidic supply of nutrients simulating the interstitial flow observed in vivo. Through combination of the microfluidic culture system with an automated fraction collector the kinetics of cellular responses by the airway epithelium to environmental agents can be analysed at the early phases for the first time and with much higher sensitivity compared to common static in vitro models. Following exposure of primary differentiated epithelial cells to pollen we show that CXCL8/IL-8 release is detectable within the first 2h and peaks at 4-6h under microfluidic conditions, a response which was not observed in conventional static culture conditions. Such a microfluidic culture model is likely to have utility for high resolution temporal profiling of toxicological and pharmacological responses of the airway epithelial barrier, as well as for studies of disease mechanisms. PMID:26436734

  19. Human airway xenograft models of epithelial cell regeneration.

    PubMed

    Puchelle, E; Peault, B

    2000-01-01

    Regeneration and restoration of the airway epithelium after mechanical, viral or bacterial injury have a determinant role in the evolution of numerous respiratory diseases such as chronic bronchitis, asthma and cystic fibrosis. The study in vivo of epithelial regeneration in animal models has shown that airway epithelial cells are able to dedifferentiate, spread, migrate over the denuded basement membrane and progressively redifferentiate to restore a functional respiratory epithelium after several weeks. Recently, human tracheal xenografts have been developed in immunodeficient severe combined immunodeficiency (SCID) and nude mice. In this review we recall that human airway cells implanted in such conditioned host grafts can regenerate a well-differentiated and functional human epithelium; we stress the interest in these humanized mice in assaying candidate progenitor and stem cells of the human airway mucosa. PMID:11667974

  20. Epithelial Cell Proliferation Contributes to Airway Remodeling in Severe Asthma

    PubMed Central

    Cohen, Lance; E, Xueping; Tarsi, Jaime; Ramkumar, Thiruvamoor; Horiuchi, Todd K.; Cochran, Rebecca; DeMartino, Steve; Schechtman, Kenneth B.; Hussain, Iftikhar; Holtzman, Michael J.; Castro, Mario

    2007-01-01

    Rationale: Despite long-term therapy with corticosteroids, patients with severe asthma develop irreversible airway obstruction. Objectives: To evaluate if there are structural and functional differences in the airway epithelium in severe asthma associated with airway remodeling. Methods: In bronchial biopsies from 21 normal subjects, 11 subjects with chronic bronchitis, 9 subjects with mild asthma, and 31 subjects with severe asthma, we evaluated epithelial cell morphology: epithelial thickness, lamina reticularis (LR) thickness, and epithelial desquamation. Levels of retinoblastoma protein (Rb), Ki67, and Bcl-2 were measured, reflecting cellular proliferation and death. Terminal deoxynucleotidyl-mediated dUTP nick end labeling (TUNEL) was used to study cellular apoptosis. Measurements and Main Results: Airway epithelial and LR thickness was greater in subjects with severe asthma compared with those with mild asthma, normal subjects, and diseased control subjects (p = 0.009 and 0.033, respectively). There was no significant difference in epithelial desquamation between groups. Active, hypophosphorylated Rb expression was decreased (p = 0.002) and Ki67 was increased (p < 0.01) in the epithelium of subjects with severe asthma as compared with normal subjects, indicating increased cellular proliferation. Bcl-2 expression was decreased (p < 0.001), indicating decreased cell death suppression. There was a greater level of apoptotic activity in the airway biopsy in subjects with severe asthma as compared with the normal subjects using the TUNEL assay (p = 0.002), suggesting increased cell death. Conclusions: In subjects with severe asthma, as compared with subjects with mild asthma, normal subjects, and diseased control subjects, we found novel evidence of increased cellular proliferation in the airway contributing to a thickened epithelium and LR. These changes may contribute to the progressive decline in lung function and airway remodeling in patients with severe

  1. EGF shifts human airway basal cell fate toward a smoking-associated airway epithelial phenotype.

    PubMed

    Shaykhiev, Renat; Zuo, Wu-Lin; Chao, Ionwa; Fukui, Tomoya; Witover, Bradley; Brekman, Angelika; Crystal, Ronald G

    2013-07-16

    The airway epithelium of smokers acquires pathological phenotypes, including basal cell (BC) and/or goblet cell hyperplasia, squamous metaplasia, structural and functional abnormalities of ciliated cells, decreased number of secretoglobin (SCGB1A1)-expressing secretory cells, and a disordered junctional barrier. In this study, we hypothesized that smoking alters airway epithelial structure through modification of BC function via an EGF receptor (EGFR)-mediated mechanism. Analysis of the airway epithelium revealed that EGFR is enriched in airway BCs, whereas its ligand EGF is induced by smoking in ciliated cells. Exposure of BCs to EGF shifted the BC differentiation program toward the squamous and epithelial-mesenchymal transition-like phenotypes with down-regulation of genes related to ciliogenesis, secretory differentiation, and markedly reduced junctional barrier integrity, mimicking the abnormalities present in the airways of smokers in vivo. These data suggest that activation of EGFR in airway BCs by smoking-induced EGF represents a unique mechanism whereby smoking can alter airway epithelial differentiation and barrier function. PMID:23818594

  2. Transcriptional PROFILING OF MUCOCILIARY DIFFERENTIATION IN HUMAN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    When cultured at an air-liquid interface (ALI) in the appropriate medium, primary human airway epithelial cells form a polarized, pseudostratified epithelium composed of ciliated and mucus-secreting cells. This culture system provides a useful tool for the in vitro study of...

  3. NITROTYROSINE ATTENUATES RSV-INDUCED INFLAMMATION IN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Nitrotyrosine attenuates RSV-induced inflammation in airway epithelial cells. Joleen Soukup, Zuowei Li, Susanne Becker and Yuh-Chin Huang. NHEERL, ORD, USEPA, RTP, North Carolina, CEMALB, University of North Carolina, Chapel Hill, North Carolina

    Nitrotyrosine (NO2Tyr) is a...

  4. Release of beryllium into artificial airway epithelial lining fluid.

    PubMed

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2012-01-01

    Inhaled beryllium particles that deposit in the lung airway lining fluid may dissolve and interact with immune-competent cells resulting in sensitization. As such, solubilization of 17 beryllium-containing materials (ore, hydroxide, metal, oxide, alloys, and process intermediates) was investigated using artificial human airway epithelial lining fluid. The maximum beryllium release in 7 days was 11.78% (from a beryl ore melter dust), although release from most materials was < 1%. Calculated dissolution half-times ranged from 30 days (reduction furnace material) to 74,000 days (hydroxide). Despite rapid mechanical clearance, billions of beryllium ions may be released in the respiratory tract via dissolution in airway lining fluid. Beryllium-containing particles that deposit in the respiratory tract dissolve in artificial lung epithelial lining fluid, thereby providing ions for absorption in the lung and interaction with immune-competent cells in the respiratory tract. PMID:23074979

  5. Airway and lung pathology due to mucosal surface dehydration in β-Epithelial Na+ Channel-overexpressing mice: role of TNFα and IL-4Rα signaling, influence of neonatal development, and limited efficacy of glucocorticoid treatment

    PubMed Central

    Livraghi, Alessandra; Grubb, Barbara R.; Hudson, Elizabeth J.; Wilkinson, Kristen J.; Sheehan, John K.; Mall, Marcus A.; O'Neal, Wanda K.; Boucher, Richard C.; Randell, Scott H.

    2009-01-01

    Overexpression of the epithelial Na+ channel β subunit (Scnn1b gene, βENaC protein) in transgenic (Tg) mouse airways dehydrates mucosal surfaces, producing mucus obstruction, inflammation, and neonatal mortality. Airway inflammation includes macrophage activation, neutrophil and eosinophil recruitment, and elevated KC, TNFα and chitinase levels. These changes recapitulate aspects of complex human obstructive airway diseases, but their molecular mechanisms are poorly understood. We used genetic and pharmacologic approaches to identify pathways relevant to the development of Scnn1b-Tg mouse lung pathology. Genetic deletion of tumor necrosis factor alpha (TNFα) or its receptor, TNFR1, had no measurable effect on the phenotype. Deletion of the interleukin-4 receptor alpha subunit (IL-4Rα) abolished transient mucous secretory cell (MuSC) abundance and eosinophilia normally observed in neonatal wild-type (WT) mice. Similarly, IL-4Rα deficiency decreased MuSC and eosinophils in neonatal Scnn1b-Tg mice, which correlated with improved neonatal survival. However, chronic lung pathology in adult Scnn1b-Tg mice was not affected by IL-4Rα status. Prednisolone treatment ablated eosinophilia and MuSC in adult Scnn1b-Tg mice, but did not decrease mucus plugging or neutrophilia. These studies demonstrate that: 1) normal neonatal mouse airway development entails an IL-4Rα-dependent, transient abundance of MuSC and eosinophils; 2) absence of IL-4Rα improved neonatal survival of Scnn1b-Tg mice, likely reflecting decreased formation of asphyxiating mucus plugs; and 3) in Scnn1b-Tg mice, neutrophilia, mucus obstruction, and airspace enlargement are IL-4Rα- and TNFα-independent, and only MuSC and eosinophilia are sensitive to glucocorticoids. Thus, manipulation of multiple pathways will likely be required to treat the complex pathogenesis caused by airway surface dehydration. PMID:19299736

  6. Tissue Inhibitor of Metalloproteinase-1 Moderates Airway Re-Epithelialization by Regulating Matrilysin Activity

    PubMed Central

    Chen, Peter; McGuire, John K.; Hackman, Robert C.; Kim, Kyoung-Hee; Black, Roy A.; Poindexter, Kurt; Yan, Wei; Liu, Phillip; Chen, Ann J.; Parks, William C.; Madtes, David K.

    2008-01-01

    Obliterative bronchiolitis (OB) is the histopathological finding in chronic lung allograft rejection. Mounting evidence suggests that epithelial damage drives the development of airway fibrosis in OB. Tissue inhibitor of metalloproteinase (TIMP)-1 expression increases in lung allografts and is associated with the onset of allograft rejection. Furthermore, in a mouse model of OB, airway obliteration is reduced in TIMP-1-deficient mice. Matrilysin (matrix metallproteinase-7) is essential for airway epithelial repair and is required for the re-epithelialization of airway wounds by facilitating cell migration; therefore, the goal of this study was to determine whether TIMP-1 inhibits re-epithelialization through matrilysin. We found that TIMP-1 and matrilysin co-localized in the epithelium of human lungs with OB and both co-localized and co-immunoprecipitated in wounded primary airway epithelial cultures. TIMP-1-deficient cultures migrated faster, and epithelial cells spread to a greater extent compared with wild-type cultures. TIMP-1 also inhibited matrilysin-mediated cell migration and spreading in vitro. In vivo, TIMP-1 deficiency enhanced airway re-epithelialization after naphthalene injury. Furthermore, TIMP-1 and matrilysin co-localized in airway epithelial cells adjacent to the wound edge. Our data demonstrate that TIMP-1 interacts with matrix metalloproteinases and regulates matrilysin activity during airway epithelial repair. Furthermore, we speculate that TIMP-1 overexpression restricts airway re-epithelialization by inhibiting matrilysin activity, contributing to a stereotypic injury response that promotes airway fibrosis via bronchiole airway epithelial damage and obliteration. PMID:18385523

  7. Observing planar cell polarity in multiciliated mouse airway epithelial cells

    PubMed Central

    Vladar, Eszter K.; Lee, Yin Loon; Stearns, Tim; Axelrod, Jeffrey D.

    2015-01-01

    The concerted movement of cilia propels inhaled contaminants out of the lungs, safeguarding the respiratory system from toxins, pathogens, pollutants, and allergens. Motile cilia on the multiciliated cells (MCCs) of the airway epithelium are physically oriented along the tissue axis for directional motility, which depends on the planar cell polarity (PCP) signaling pathway. The MCCs of the mouse respiratory epithelium have emerged as an important model for the study of motile ciliogenesis and the PCP signaling mechanism. Unlike other motile ciliated or planar polarized tissues, airway epithelial cells are relatively easily accessible and primary cultures faithfully model many of the essential features of the in vivo tissue. There is growing interest in understanding how cells acquire and polarize motile cilia due to the impact of mucociliary clearance on respiratory health. Here, we present methods for observing and quantifying the planar polarized orientation of motile cilia both in vivo and in primary culture airway epithelial cells. We describe how to acquire and evaluate electron and light microscopy images of ciliary ultrastructural features that reveal planar polarized orientation. Furthermore, we describe the immunofluorescence localization of PCP pathway components as a simple readout for airway epithelial planar polarization and ciliary orientation. These methods can be adapted to observe ciliary orientation in other multi- and monociliated cells and to detect PCP pathway activity in any tissue or cell type. PMID:25837385

  8. Interleukin-4 and interleukin-13 cause barrier dysfunction in human airway epithelial cells.

    PubMed

    Saatian, Bahman; Rezaee, Fariba; Desando, Samantha; Emo, Jason; Chapman, Tim; Knowlden, Sara; Georas, Steve N

    2013-04-01

    Emerging evidence indicates that airway epithelial barrier function is compromised in asthma, a disease characterized by Th2-skewed immune response against inhaled allergens, but the mechanisms involved are not well understood. The purpose of this study was to investigate the effects of Th2-type cytokines on airway epithelial barrier function. 16HBE14o- human bronchial epithelial cells monolayers were grown on collagen coated Transwell inserts. The basolateral or apical surfaces of airway epithelia were exposed to human interleukin-4 (IL-4), IL-13, IL-25, IL-33, thymic stromal lymphopoietin (TSLP) alone or in combination at various concentrations and time points. We analyzed epithelial apical junctional complex (AJC) function by measuring transepithelial electrical resistance (TEER) and permeability to FITC-conjugated dextran over time. We analyzed AJC structure using immunofluorescence with antibodies directed against key junctional components including occludin, ZO-1, β-catenin and E-cadherin. Transepithelial resistance was significantly decreased after both basolateral and apical exposure to IL-4. Permeability to 3 kDa dextran was also increased in IL-4-exposed cells. Similar results were obtained with IL-13, but none of the innate type 2 cytokines examined (TSLP, IL-25 or IL-33) significantly affected barrier function. IL-4 and IL-13-induced barrier dysfunction was accompanied by reduced expression of membrane AJC components but not by induction of claudin- 2. Enhanced permeability caused by IL-4 was not affected by wortmannin, an inhibitor of PI3 kinase signaling, but was attenuated by a broad spectrum inhibitor of janus associated kinases. Our study indicates that IL-4 and IL-13 have disruptive effect on airway epithelial barrier function. Th2-cytokine induced epithelial barrier dysfunction may contribute to airway inflammation in allergic asthma. PMID:24665390

  9. Dual Function of Novel Pollen Coat (Surface) Proteins: IgE-binding Capacity and Proteolytic Activity Disrupting the Airway Epithelial Barrier

    PubMed Central

    Bashir, Mohamed Elfatih H.; Ward, Jason M.; Cummings, Matthew; Karrar, Eltayeb E.; Root, Michael; Mohamed, Abu Bekr A.; Naclerio, Robert M.; Preuss, Daphne

    2013-01-01

    Background The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., “de-fatted”), and, as a result, their involvement in allergy has not been explored. Methodology/Principal Findings Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM) to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass) pollen (BGP) by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP) and endoxylanase (EXY). The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. Conclusions/Significance Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic responses is

  10. Airway Epithelial miRNA Expression Is Altered in Asthma

    PubMed Central

    Solberg, Owen D.; Ostrin, Edwin J.; Love, Michael I.; Peng, Jeffrey C.; Bhakta, Nirav R.; Nguyen, Christine; Solon, Margaret; Nguyen, Cindy; Barczak, Andrea J.; Zlock, Lorna T.; Blagev, Denitza P.; Finkbeiner, Walter E.; Ansel, K. Mark; Arron, Joseph R.; Erle, David J.

    2012-01-01

    Rationale: Changes in airway epithelial cell differentiation, driven in part by IL-13, are important in asthma. Micro-RNAs (miRNAs) regulate cell differentiation in many systems and could contribute to epithelial abnormalities in asthma. Objectives: To determine whether airway epithelial miRNA expression is altered in asthma and identify IL-13–regulated miRNAs. Methods: We used miRNA microarrays to analyze bronchial epithelial brushings from 16 steroid-naive subjects with asthma before and after inhaled corticosteroids, 19 steroid-using subjects with asthma, and 12 healthy control subjects, and the effects of IL-13 and corticosteroids on cultured bronchial epithelial cells. We used quantitative polymerase chain reaction to confirm selected microarray results. Measurements and Main Results: Most (12 of 16) steroid-naive subjects with asthma had a markedly abnormal pattern of bronchial epithelial miRNA expression by microarray analysis. Compared with control subjects, 217 miRNAs were differentially expressed in steroid-naive subjects with asthma and 200 in steroid-using subjects with asthma (false discovery rate < 0.05). Treatment with inhaled corticosteroids had modest effects on miRNA expression in steroid-naive asthma, inducing a statistically significant (false discovery rate < 0.05) change for only nine miRNAs. qPCR analysis confirmed differential expression of 22 miRNAs that were highly differentially expressed by microarrays. IL-13 stimulation recapitulated changes in many differentially expressed miRNAs, including four members of the miR-34/449 family, and these changes in miR-34/449 family members were resistant to corticosteroids. Conclusions: Dramatic alterations of airway epithelial cell miRNA levels are a common feature of asthma. These alterations are only modestly corrected by inhaled corticosteroids. IL-13 effects may account for some of these alterations, including repression of miR-34/449 family members that have established roles in airway

  11. Airway epithelial repair in health and disease: Orchestrator or simply a player?

    PubMed

    Iosifidis, Thomas; Garratt, Luke W; Coombe, Deirdre R; Knight, Darryl A; Stick, Stephen M; Kicic, Anthony

    2016-04-01

    Epithelial cells represent the most important surface of contact in the body and form the first line of defence of the body to external environment. Consequently, epithelia have numerous roles in order to maintain a homeostatic defence barrier. Although the epithelium has been extensively studied over several decades, it remains the focus of new research, indicating a lack of understanding that continues to exist around these cells in specific disease settings. Importantly, evidence is emerging that airway epithelial cells in particular have varied complex functions rather than simple passive roles. One area of current interest is its role following injury. In particular, the epithelial-specific cellular mechanisms regulating their migration during wound repair remain poorly understood and remain an area that requires much needed investigation. A better understanding of the physiological, cellular and molecular wound repair mechanisms could assist in elucidating pathological processes that contribute to airway epithelial pathology. This review attempts to highlight migration-specific and cell-extracellular matrix (ECM) aspects of repair used by epithelial cells under normal and disease settings, in the context of human airways. PMID:26804630

  12. Long-term cultures of polarized airway epithelial cells from patients with cystic fibrosis.

    PubMed

    Wiszniewski, Ludovic; Jornot, Lan; Dudez, Tecla; Pagano, Alessandra; Rochat, Thierry; Lacroix, Jean Silvain; Suter, Susanne; Chanson, Marc

    2006-01-01

    The poor ability of respiratory epithelial cells to proliferate and differentiate in vitro into a pseudostratified mucociliated epithelium limits the general use of primary airway epithelial cell (AEC) cultures generated from patients with rare diseases, such as cystic fibrosis (CF). Here, we describe a procedure to amplify AEC isolated from nasal polyps and generate long-term cultures of the respiratory epithelium. AEC were seeded onto microporous permeable supports that carried on their undersurface a preformed feeder layer of primary human airway fibroblasts. The use of fibroblast feeder layers strongly stimulated the proliferation of epithelial cells, allowing the expansion of the cell pool with successive passages. AEC at increasing passage were seeded onto supports undercoated with airway fibroblasts and exposed to air. Either freshly isolated or amplified AEC could differentiate into a pseudostratified mucociliated epithelium for at least 10 mo. Thus, CF epithelia cultures showed elevated Na+ transport, drastic hyperabsorption of surface liquid, and absence of cAMP-induced Cl- secretion as compared with non-CF cultures. They were also characterized by thick apical secretion that hampered the movement of cell surface debris by cilia. However, CF respiratory epithelia did not show increased production of mucins or IL-8. The method described here is now routinely used in our laboratory to establish long-term cultures of well differentiated respiratory epithelia from human airway biopsies. PMID:16179582

  13. Gene Transfer by Guanidinium-Cholesterol Cationic Lipids into Airway Epithelial Cells in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Oudrhiri, Noufissa; Vigneron, Jean-Pierre; Peuchmaur, Michel; Leclerc, Tony; Lehn, Jean-Marie; Lehn, Pierre

    1997-03-01

    Synthetic vectors represent an attractive alternative approach to viral vectors for gene transfer, in particular into airway epithelial cells for lung-directed gene therapy for cystic fibrosis. Having recently found that guanidinium-cholesterol cationic lipids are efficient reagents for gene transfer into mammalian cell lines in vitro, we have investigated their use for gene delivery into primary airway epithelial cells in vitro and in vivo. The results obtained indicate that the lipid bis (guanidinium)-tren-cholesterol (BGTC) can be used to transfer a reporter gene into primary human airway epithelial cells in culture. Furthermore, liposomes composed of BGTC and dioleoyl phosphatidylethanolamine (DOPE) are efficient for gene delivery to the mouse airway epithelium in vivo. Transfected cells were detected both in the surface epithelium and in submucosal glands. In addition, the transfection efficiency of BGTC/DOPE liposomes in vivo was quantitatively assessed by using the luciferase reporter gene system.

  14. Airway epithelial cell response to human metapneumovirus infection

    SciTech Connect

    Bao, X.; Liu, T.; Spetch, L.; Kolli, D.; Garofalo, R.P.; Casola, A.

    2007-11-10

    Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections (LRTIs) in infants, elderly and immunocompromised patients. In this study, we show that hMPV can infect in a similar manner epithelial cells representative of different tracts of the airways. hMPV-induced expression of chemokines IL-8 and RANTES in primary small alveolar epithelial cells (SAE) and in a human alveolar type II-like epithelial cell line (A549) was similar, suggesting that A549 cells can be used as a model to study lower airway epithelial cell responses to hMPV infection. A549 secreted a variety of CXC and CC chemokines, cytokines and type I interferons, following hMPV infection. hMPV was also a strong inducer of transcription factors belonging to nuclear factor (NF)-{kappa}B, interferon regulatory factors (IRFs) and signal transducers and activators of transcription (STATs) families, which are known to orchestrate the expression of inflammatory and immunomodulatory mediators.

  15. AIRWAY EPITHELIAL CELL RESPONSE TO HUMAN METAPNEUMOVIRUS INFECTION

    PubMed Central

    X, Bao; T, Liu; L, Spetch; D, Kolli; R.P, Garofalo; A, Casola

    2007-01-01

    Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections (LRTIs) in infants, elderly and immunocompromised patients. In this study, we show that hMPV can infect in a similar manner epithelial cells representative of different tracts of the airways. hMPV-induced expression of chemokines IL-8 and RANTES in primary small alveolar epithelial cells (SAE) and in a human alveolar type II-like epithelial cell line (A549) was similar, suggesting that A549 cells can be used as a model to study lower airway epithelial cell responses to hMPV infection. A549 secreted a variety of CXC and CC chemokines, cytokines and type I interferons, following hMPV infection. hMPV was also a strong inducer of transcription factors belonging to nuclear factor (NF)-κB, interferon regulatory factors (IRFs) and signal transducers and activators of transcription (STATs) families, which are known to orchestrate the expression of inflammatory and immuno-modulatory mediators. PMID:17655903

  16. Airway surface liquid depth imaged by surface laser reflectance microscopy.

    PubMed

    Thiagarajah, Jay R; Song, Yuanlin; Derichs, Nico; Verkman, A S

    2010-09-01

    The thin layer of liquid at the surface of airway epithelium, the airway surface liquid (ASL), is important in normal airway physiology and in the pathophysiology of cystic fibrosis. At present, the best method to measure ASL depth involves scanning confocal microscopy after staining with an aqueous-phase fluorescent dye. We describe here a simple, noninvasive imaging method to measure ASL depth by reflectance imaging of an epithelial mucosa in which the surface is illuminated at a 45-degree angle by an elongated 13-microm wide rectangular beam produced by a 670-nm micro-focus laser. The principle of the method is that air-liquid, liquid-liquid, and liquid-cell interfaces produce distinct specular or diffuse reflections that can be imaged to give a micron-resolution replica of the mucosal surface. The method was validated using fluid layers of specified thicknesses and applied to measure ASL depth in cell cultures and ex vivo fragments of pig trachea. In addition, the method was adapted to measure transepithelial fluid transport from the dynamics of fluid layer depth. Compared with confocal imaging, ASL depth measurement by surface laser reflectance microscopy does not require dye staining or costly instrumentation, and can potentially be adapted for in vivo measurements using fiberoptics. PMID:20713545

  17. Nitric Oxide and Airway Epithelial Barrier Function: Regulation of Tight Junction Proteins and Epithelial Permeability

    PubMed Central

    Olson, Nels; Greul, Anne-Katrin; Hristova, Milena; Bove, Peter F.; Kasahara, David I.; van der Vliet, Albert

    2008-01-01

    Acute airway inflammation is associated with enhanced production of nitric oxide (NO•) and altered airway epithelial barrier function, suggesting a role of NO• or its metabolites in epithelial permeability. While high concentrations of S-nitrosothiols disrupted transepithelial resistance (TER) and increased permeability in 16HBE14o- cells, no significant barrier disruption was observed by NONOates, in spite of altered distribution and expression of some TJ proteins. Barrier disruption of mouse tracheal epithelial (MTE) cell monolayers in response to inflammatory cytokines was independent of NOS2, based on similar effects in MTE cells from NOS2-/- mice and a lack of effect of the NOS2-inhibitor 1400W. Cell pre-incubation with LPS protected MTE cells from TER loss and increased permeability by H2O2, which was independent of NOS2. However, NOS2 was found to contribute to epithelial wound repair and TER recovery after mechanical injury. Overall, our results demonstrate that epithelial NOS2 is not responsible for epithelial barrier dysfunction during inflammation, but may contribute to restoration of epithelial integrity. PMID:19100237

  18. High mobility group box 1-induced epithelial mesenchymal transition in human airway epithelial cells.

    PubMed

    Chen, Yu-Ching; Statt, Sarah; Wu, Reen; Chang, Hao-Teng; Liao, Jiunn-Wang; Wang, Chien-Neng; Shyu, Woei-Cherng; Lee, Chen-Chen

    2016-01-01

    Epithelial-mesenchymal transition (EMT) is implicated in bronchial remodeling and loss of lung function in chronic inflammatory airway diseases. Previous studies showed the involvement of the high mobility group box 1 (HMGB1) protein in the pathology of chronic pulmonary inflammatory diseases. However, the role of HMGB1 in EMT of human airway epithelial cells is still unclear. In this study, we used RNA sequencing to show that HMGB1 treatment regulated EMT-related gene expression in human primary-airway epithelial cells. The top five upregulated genes were SNAI2, FGFBP1, VIM, SPARC (osteonectin), and SERPINE1, while the downregulated genes included OCLN, TJP1 (ZO-1), FZD7, CDH1 (E-cadherin), and LAMA5. We found that HMGB1 induced downregulation of E-cadherin and ZO-1, and upregulation of vimentin mRNA transcription and protein translation in a dose-dependent manner. Additionally, we observed that HMGB1 induced AKT phosphorylation, resulting in GSK3β inactivation, cytoplasmic accumulation, and nuclear translocation of β-catenin to induce EMT in human airway epithelial cells. Treatment with PI3K inhibitor (LY294006) and β-catenin shRNA reversed HMGB1-induced EMT. Moreover, HMGB1 induced expression of receptor for advanced glycation products (RAGE), but not that of Toll-like receptor (TLR) 2 or TLR4, and RAGE shRNA inhibited HMGB1-induced EMT in human airway epithelial cells. In conclusion, we found that HMGB1 induced EMT through RAGE and the PI3K/AKT/GSK3β/β-catenin signaling pathway. PMID:26739898

  19. Epithelial Notch signaling regulates lung alveolar morphogenesis and airway epithelial integrity.

    PubMed

    Tsao, Po-Nien; Matsuoka, Chisa; Wei, Shu-Chen; Sato, Atsuyasu; Sato, Susumu; Hasegawa, Koichi; Chen, Hung-Kuan; Ling, Thai-Yen; Mori, Munemasa; Cardoso, Wellington V; Morimoto, Mitsuru

    2016-07-19

    Abnormal enlargement of the alveolar spaces is a hallmark of conditions such as chronic obstructive pulmonary disease and bronchopulmonary dysplasia. Notch signaling is crucial for differentiation and regeneration and repair of the airway epithelium. However, how Notch influences the alveolar compartment and integrates this process with airway development remains little understood. Here we report a prominent role of Notch signaling in the epithelial-mesenchymal interactions that lead to alveolar formation in the developing lung. We found that alveolar type II cells are major sites of Notch2 activation and show by Notch2-specific epithelial deletion (Notch2(cNull)) a unique contribution of this receptor to alveologenesis. Epithelial Notch2 was required for type II cell induction of the PDGF-A ligand and subsequent paracrine activation of PDGF receptor-α signaling in alveolar myofibroblast progenitors. Moreover, Notch2 was crucial in maintaining the integrity of the epithelial and smooth muscle layers of the distal conducting airways. Our data suggest that epithelial Notch signaling regulates multiple aspects of postnatal development in the distal lung and may represent a potential target for intervention in pulmonary diseases. PMID:27364009

  20. Circulating progenitor epithelial cells traffic via CXCR4/CXCL12 in response to airway injury.

    PubMed

    Gomperts, Brigitte N; Belperio, John A; Rao, P Nagesh; Randell, Scott H; Fishbein, Michael C; Burdick, Marie D; Strieter, Robert M

    2006-02-01

    Recipient airway epithelial cells are found in human sex-mismatched lung transplants, implying that circulating progenitor epithelial cells contribute to the repair of the airway epithelium. Markers of circulating progenitor epithelial cells and mechanisms for their trafficking remain to be elucidated. We demonstrate that a population of progenitor epithelial cells exists in the bone marrow and the circulation of mice that is positive for the early epithelial marker cytokeratin 5 (CK5) and the chemokine receptor CXCR4. We used a mouse model of sex-mismatched tracheal transplantation and found that CK5+ circulating progenitor epithelial cells contribute to re-epithelialization of the airway and re-establishment of the pseudostratified epithelium. The presence of CXCL12 in tracheal transplants provided a mechanism for CXCR4+ circulating progenitor epithelial cell recruitment to the airway. Depletion of CXCL12 resulted in the epithelium defaulting to squamous metaplasia, which was derived solely from the resident tissue progenitor epithelial cells. Our findings demonstrate that CK5+CXCR4+ cells are markers of circulating progenitor epithelial cells in the bone marrow and circulation and that CXCR4/CXCL12-mediated recruitment of circulating progenitor epithelial cells is necessary for the re-establishment of a normal pseudostratified epithelium after airway injury. These findings support a novel paradigm for the development of squamous metaplasia of the airway epithelium and for developing therapeutic strategies for circulating progenitor epithelial cells in airway diseases. PMID:16424223

  1. Role of Allergen Source-Derived Proteases in Sensitization via Airway Epithelial Cells

    PubMed Central

    Matsumura, Yasuhiro

    2012-01-01

    Protease activity is a characteristic common to many allergens. Allergen source-derived proteases interact with lung epithelial cells, which are now thought to play vital roles in both innate and adaptive immune responses. Allergen source-derived proteases act on airway epithelial cells to induce disruption of the tight junctions between epithelial cells, activation of protease-activated receptor-2, and the production of thymic stromal lymphopoietin. These facilitate allergen delivery across epithelial layers and enhance allergenicity or directly activate the immune system through a nonallergic mechanism. Furthermore, they cleave regulatory cell surface molecules involved in allergic reactions. Thus, allergen source-derived proteases are a potentially critical factor in the development of allergic sensitization and appear to be strongly associated with heightened allergenicity. PMID:22523502

  2. c-Myc regulates proliferation and Fgf10 expression in airway smooth muscle after airway epithelial injury in mouse.

    PubMed

    Volckaert, Thomas; Campbell, Alice; De Langhe, Stijn

    2013-01-01

    During lung development, Fibroblast growth factor 10 (Fgf10), which is expressed in the distal mesenchyme and regulated by Wnt signaling, acts on the distal epithelial progenitors to maintain them and prevent them from differentiating into proximal (airway) epithelial cells. Fgf10-expressing cells in the distal mesenchyme are progenitors for parabronchial smooth muscle cells (PSMCs). After naphthalene, ozone or bleomycin-induced airway epithelial injury, surviving epithelial cells secrete Wnt7b which then activates the PSMC niche to induce Fgf10 expression. This Fgf10 secreted by the niche then acts on a subset of Clara stem cells to break quiescence, induce proliferation and initiate epithelial repair. Here we show that conditional deletion of the Wnt target gene c-Myc from the lung mesenchyme during development does not affect proper epithelial or mesenchymal differentiation. However, in the adult lung we show that after naphthalene-mediated airway epithelial injury c-Myc is important for the activation of the PSMC niche and as such induces proliferation and Fgf10 expression in PSMCs. Our data indicate that conditional deletion of c-Myc from PSMCs inhibits airway epithelial repair, whereas c-Myc ablation from Clara cells has no effect on airway epithelial regeneration. These findings may have important implications for understanding the misregulation of lung repair in asthma and COPD. PMID:23967208

  3. An uptake of cationized ferritin by alveolar type I cells in airway-instilled goat lung: distribution of anionic sites on the epithelial surface.

    PubMed

    Atwal, O S; Viel, L; Minhas, K J

    1990-07-01

    The present study has investigated ultrastructural localization of anionic sites on the luminal surface of the alveolar epithelium of goat lung by direct airway instillation of cationized ferritin (CF) in the cranial lobe of the right lung through a bronchoscope. The cationic probe decorated preferentially the luminal plasmalemmal vesicles and plasmalemma proper of alveolar type I cell. This indicated the presence of highly charged anionic microdomains at these binding sites. The ligand was internalized in the free plasmalemmal vesicles of alveolar type I cell within 2 min. Heavy decoration of vesicles at 5 min of perfusion indicated that the amount of CF internalization increased with its concentration in the alveoli. It is suggested that exposure of alveolar surface to several gases of ruminal-origin induces changes in the surface charge of luminal plasmalemma of alveolar type I cells. The significance of these anionic plasmalemmal sites is discussed in relation to the adjustment of osmotic pressure gradient across the alveolar-capillary membrane of the ruminant lung. PMID:2390765

  4. High mobility group box 1-induced epithelial mesenchymal transition in human airway epithelial cells

    PubMed Central

    Chen, Yu-Ching; Statt, Sarah; Wu, Reen; Chang, Hao-Teng; Liao, Jiunn-Wang; Wang, Chien-Neng; Shyu, Woei-Cherng; Lee, Chen-Chen

    2016-01-01

    Epithelial–mesenchymal transition (EMT) is implicated in bronchial remodeling and loss of lung function in chronic inflammatory airway diseases. Previous studies showed the involvement of the high mobility group box 1 (HMGB1) protein in the pathology of chronic pulmonary inflammatory diseases. However, the role of HMGB1 in EMT of human airway epithelial cells is still unclear. In this study, we used RNA sequencing to show that HMGB1 treatment regulated EMT-related gene expression in human primary-airway epithelial cells. The top five upregulated genes were SNAI2, FGFBP1, VIM, SPARC (osteonectin), and SERPINE1, while the downregulated genes included OCLN, TJP1 (ZO-1), FZD7, CDH1 (E-cadherin), and LAMA5. We found that HMGB1 induced downregulation of E-cadherin and ZO-1, and upregulation of vimentin mRNA transcription and protein translation in a dose-dependent manner. Additionally, we observed that HMGB1 induced AKT phosphorylation, resulting in GSK3β inactivation, cytoplasmic accumulation, and nuclear translocation of β-catenin to induce EMT in human airway epithelial cells. Treatment with PI3K inhibitor (LY294006) and β-catenin shRNA reversed HMGB1-induced EMT. Moreover, HMGB1 induced expression of receptor for advanced glycation products (RAGE), but not that of Toll-like receptor (TLR) 2 or TLR4, and RAGE shRNA inhibited HMGB1-induced EMT in human airway epithelial cells. In conclusion, we found that HMGB1 induced EMT through RAGE and the PI3K/AKT/GSK3β/β-catenin signaling pathway. PMID:26739898

  5. Epithelial Notch signaling regulates lung alveolar morphogenesis and airway epithelial integrity

    PubMed Central

    Tsao, Po-Nien; Matsuoka, Chisa; Wei, Shu-Chen; Sato, Atsuyasu; Sato, Susumu; Hasegawa, Koichi; Chen, Hung-kuan; Ling, Thai-Yen; Mori, Munemasa; Cardoso, Wellington V.; Morimoto, Mitsuru

    2016-01-01

    Abnormal enlargement of the alveolar spaces is a hallmark of conditions such as chronic obstructive pulmonary disease and bronchopulmonary dysplasia. Notch signaling is crucial for differentiation and regeneration and repair of the airway epithelium. However, how Notch influences the alveolar compartment and integrates this process with airway development remains little understood. Here we report a prominent role of Notch signaling in the epithelial–mesenchymal interactions that lead to alveolar formation in the developing lung. We found that alveolar type II cells are major sites of Notch2 activation and show by Notch2-specific epithelial deletion (Notch2cNull) a unique contribution of this receptor to alveologenesis. Epithelial Notch2 was required for type II cell induction of the PDGF-A ligand and subsequent paracrine activation of PDGF receptor-α signaling in alveolar myofibroblast progenitors. Moreover, Notch2 was crucial in maintaining the integrity of the epithelial and smooth muscle layers of the distal conducting airways. Our data suggest that epithelial Notch signaling regulates multiple aspects of postnatal development in the distal lung and may represent a potential target for intervention in pulmonary diseases. PMID:27364009

  6. Syntaxin 1A is expressed in airway epithelial cells, where it modulates CFTR Cl– currents

    PubMed Central

    Naren, Anjaparavanda P.; Di, Anke; Cormet-Boyaka, Estelle; Boyaka, Prosper N.; McGhee, Jerry R.; Zhou, Weihong; Akagawa, Kimio; Fujiwara, Tomonori; Thome, Ulrich; Engelhardt, John F.; Nelson, Deborah J.; Kirk, Kevin L.

    2000-01-01

    The CFTR Cl– channel controls salt and water transport across epithelial tissues. Previously, we showed that CFTR-mediated Cl– currents in the Xenopus oocyte expression system are inhibited by syntaxin 1A, a component of the membrane trafficking machinery. This negative modulation of CFTR function can be reversed by soluble syntaxin 1A peptides and by the syntaxin 1A binding protein, Munc-18. In the present study, we determined whether syntaxin 1A is expressed in native epithelial tissues that normally express CFTR and whether it modulates CFTR currents in these tissues. Using immunoblotting and immunofluorescence, we observed syntaxin 1A in native gut and airway epithelial tissues and showed that epithelial cells from these tissues express syntaxin 1A at >10-fold molar excess over CFTR. Syntaxin 1A is seen near the apical cell surfaces of human bronchial airway epithelium. Reagents that disrupt the CFTR-syntaxin 1A interaction, including soluble syntaxin 1A cytosolic domain and recombinant Munc-18, augmented cAMP-dependent CFTR Cl– currents by more than 2- to 4-fold in mouse tracheal epithelial cells and cells derived from human nasal polyps, but these reagents did not affect CaMK II–activated Cl– currents in these cells. PMID:10675364

  7. Inhibition of airway surface fluid absorption by cholinergic stimulation

    PubMed Central

    Joo, Nam Soo; Krouse, Mauri E.; Choi, Jae Young; Cho, Hyung-Ju; Wine, Jeffrey J.

    2016-01-01

    In upper airways airway surface liquid (ASL) depth and clearance rates are both increased by fluid secretion. Secretion is opposed by fluid absorption, mainly via the epithelial sodium channel, ENaC. In static systems, increased fluid depth activates ENaC and decreased depth inhibits it, suggesting that secretion indirectly activates ENaC to reduce ASL depth. We propose an alternate mechanism in which cholinergic input, which causes copious airway gland secretion, also inhibits ENaC-mediated absorption. The conjoint action accelerates clearance, and the increased transport of mucus out of the airways restores ASL depth while cleansing the airways. We were intrigued by early reports of cholinergic inhibition of absorption by airways in some species. To reinvestigate this phenomenon, we studied inward short-circuit currents (Isc) in tracheal mucosa from human, sheep, pig, ferret, and rabbit and in two types of cultured cells. Basal Isc was inhibited 20–70% by the ENaC inhibitor, benzamil. Long-lasting inhibition of ENaC-dependent Isc was also produced by basolateral carbachol in all preparations except rabbit and the H441 cell line. Atropine inhibition produced a slow recovery or prevented inhibition if added before carbachol. The mechanism for inhibition was not determined and is most likely multi-factorial. However, its physiological significance is expected to be increased mucus clearance rates in cholinergically stimulated airways. PMID:26846701

  8. Inhibition of airway surface fluid absorption by cholinergic stimulation.

    PubMed

    Joo, Nam Soo; Krouse, Mauri E; Choi, Jae Young; Cho, Hyung-Ju; Wine, Jeffrey J

    2016-01-01

    In upper airways airway surface liquid (ASL) depth and clearance rates are both increased by fluid secretion. Secretion is opposed by fluid absorption, mainly via the epithelial sodium channel, ENaC. In static systems, increased fluid depth activates ENaC and decreased depth inhibits it, suggesting that secretion indirectly activates ENaC to reduce ASL depth. We propose an alternate mechanism in which cholinergic input, which causes copious airway gland secretion, also inhibits ENaC-mediated absorption. The conjoint action accelerates clearance, and the increased transport of mucus out of the airways restores ASL depth while cleansing the airways. We were intrigued by early reports of cholinergic inhibition of absorption by airways in some species. To reinvestigate this phenomenon, we studied inward short-circuit currents (Isc) in tracheal mucosa from human, sheep, pig, ferret, and rabbit and in two types of cultured cells. Basal Isc was inhibited 20-70% by the ENaC inhibitor, benzamil. Long-lasting inhibition of ENaC-dependent Isc was also produced by basolateral carbachol in all preparations except rabbit and the H441 cell line. Atropine inhibition produced a slow recovery or prevented inhibition if added before carbachol. The mechanism for inhibition was not determined and is most likely multi-factorial. However, its physiological significance is expected to be increased mucus clearance rates in cholinergically stimulated airways. PMID:26846701

  9. Surface fluid absorption and secretion in small airways

    PubMed Central

    Shamsuddin, A K M; Quinton, P M

    2012-01-01

    Native small airways must remain wet enough to be pliable and support ciliary clearance, but dry enough to remain patent for gas flow. The airway epithelial lining must both absorb and secrete ions to maintain a critical level of fluid on its surface. Despite frequent involvement in lung diseases, the minuscule size has limited studies of peripheral airways. To meet this challenge, we used a capillary to construct an Ussing chamber (area <1 mm2) to measure electrolyte transport across small native airways (∼1 mm ø) from pig lung. Transepithelial potentials (Vt) were recorded in open circuit conditions while applying constant current pulses across the luminal surface of dissected airways to calculate transepithelial electrical conductance (Gt) and equivalent short circuit current () in the presence and absence of selected Na+ and Cl− transport inhibitors (amiloride, GlyH-101, Niflumic acid) and agonists (Forskolin + IBMX, UTP). Considered together the responses suggest an organ composed of both secreting and absorbing epithelia that constitutively and concurrently transport fluids into and out of the airway, i.e. in opposite directions. Since the epithelial lining of small airways is arranged in long, accordion-like rows of pleats and folds that run axially down the lumen, we surmise that cells within the pleats are mainly secretory while the cells of the folds are principally absorptive. This structural arrangement could provide local fluid transport from within the pleats toward the luminal folds that may autonomously regulate the local surface fluid volume for homeostasis while permitting acute responses to maintain clearance. PMID:22547637

  10. High glucose induces dysfunction of airway epithelial barrier through down-regulation of connexin 43.

    PubMed

    Yu, Hongmei; Yang, Juan; Zhou, Xiangdong; Xiao, Qian; Lü, Yang; Xia, Li

    2016-03-01

    The airway epithelium is a barrier to the inhaled antigens and pathogens. Connexin 43 (Cx43) has been found to play critical role in maintaining the function of airway epithelial barrier and be involved in the pathogenesis of the diabetic retinal vasculature, diabetes nephropathy and diabetes skin. Hyperglycemia has been shown to be an independent risk factor for respiratory infections. We hypothesize that the down-regulation of Cx43 induced by HG alters the expression of tight junctions (zonula occludens-1 (ZO-1) and occludin) and contributes to dysfunction of airway epithelial barrier, and Cx43 plays a critical role in the process in human airway epithelial cells (16 HBE). We show that high glucose (HG) decreased the expression of ZO-1 and occludin, disassociated interaction between Cx43 and tight junctions, and then increased airway epithelial transepithelial electrical resistance (TER) and permeability by down-regulation of Cx43 in human airway epithelial cells. These observations demonstrate an important role for Cx43 in regulating HG-induced dysfunction of airway epithelial barrier. These findings may bring new insights into the molecular pathogenesis of pulmonary infection related to diabetes mellitus and lead to novel therapeutic intervention for the dysfunction of airway epithelial barrier in chronic inflammatory airway diseases. PMID:26902399

  11. Desialylation of airway epithelial cells during influenza virus infection enhances pneumococcal adhesion via galectin binding

    PubMed Central

    Nita-Lazar, Mihai; Banerjee, Aditi; Feng, Chiguang; Amin, Mohammed N.; Frieman, Matthew B.; Chen, Wilbur H.; Cross, Alan S.; Wang, Lai-Xi; Vasta, Gerardo R.

    2015-01-01

    The continued threat of worldwide influenza pandemics, together with the yearly emergence of antigenically drifted influenza A virus (IAV) strains, underscore the urgent need to elucidate not only the mechanisms of influenza virulence, but also those mechanisms that predispose influenza patients to increased susceptibility to subsequent infection with Streptococcus pneumoniae. Glycans displayed on the surface of epithelia that are exposed to the external environment play important roles in microbial recognition, adhesion, and invasion. It is well established that the IAV hemagglutinin and pneumococcal adhesins enable their attachment to the host epithelia. Reciprocally, the recognition of microbial glycans by host carbohydrate-binding proteins (lectins) can initiate innate immune responses, but their relevance in influenza or pneumococcal infections is poorly understood. Galectins are evolutionarily conserved lectins characterized by affinity for β-galactosides and a unique sequence motif, with critical regulatory roles in development and immune homeostasis. In this study, we examined the possibility that galectins expressed in the airway epithelial cells might play a significant role in viral or pneumococcal adhesion to airway epithelial cells. Our results in a mouse model for influenza and pneumococcal infection revealed that the murine lung expresses a diverse galectin repertoire, from which selected galectins, including galectin 1 (Gal1) and galectin 3 (Gal3), are released to the bronchoalveolar space. Further, the results showed that influenza and subsequent S. pneumoniae infections significantly alter the glycosylation patterns of the airway epithelial surface and modulate galectin expression. In vitro studies on the human airway epithelial cell line A549 were consistent with the observations made in the mouse model, and further revealed that both Gal1 and Gal3 bind strongly to IAV and S. pneumoniae, and that exposure of the cells to viral neuraminidase or

  12. Directed Induction of Functional Multi-ciliated Cells in Proximal Airway Epithelial Spheroids from Human Pluripotent Stem Cells

    PubMed Central

    Konishi, Satoshi; Gotoh, Shimpei; Tateishi, Kazuhiro; Yamamoto, Yuki; Korogi, Yohei; Nagasaki, Tadao; Matsumoto, Hisako; Muro, Shigeo; Hirai, Toyohiro; Ito, Isao; Tsukita, Sachiko; Mishima, Michiaki

    2015-01-01

    Summary Multi-ciliated airway cells (MCACs) play a role in mucociliary clearance of the lung. However, the efficient induction of functional MCACs from human pluripotent stem cells has not yet been reported. Using carboxypeptidase M (CPM) as a surface marker of NKX2-1+-ventralized anterior foregut endoderm cells (VAFECs), we report a three-dimensional differentiation protocol for generating proximal airway epithelial progenitor cell spheroids from CPM+ VAFECs. These spheroids could be induced to generate MCACs and other airway lineage cells without alveolar epithelial cells. Furthermore, the directed induction of MCACs and of pulmonary neuroendocrine lineage cells was promoted by adding DAPT, a Notch pathway inhibitor. The induced MCACs demonstrated motile cilia with a “9 + 2” microtubule arrangement and dynein arms capable of beating and generating flow for mucociliary transport. This method is expected to be useful for future studies on human airway disease modeling and regenerative medicine. PMID:26724905

  13. Directed Induction of Functional Multi-ciliated Cells in Proximal Airway Epithelial Spheroids from Human Pluripotent Stem Cells.

    PubMed

    Konishi, Satoshi; Gotoh, Shimpei; Tateishi, Kazuhiro; Yamamoto, Yuki; Korogi, Yohei; Nagasaki, Tadao; Matsumoto, Hisako; Muro, Shigeo; Hirai, Toyohiro; Ito, Isao; Tsukita, Sachiko; Mishima, Michiaki

    2016-01-12

    Multi-ciliated airway cells (MCACs) play a role in mucociliary clearance of the lung. However, the efficient induction of functional MCACs from human pluripotent stem cells has not yet been reported. Using carboxypeptidase M (CPM) as a surface marker of NKX2-1(+)-ventralized anterior foregut endoderm cells (VAFECs), we report a three-dimensional differentiation protocol for generating proximal airway epithelial progenitor cell spheroids from CPM(+) VAFECs. These spheroids could be induced to generate MCACs and other airway lineage cells without alveolar epithelial cells. Furthermore, the directed induction of MCACs and of pulmonary neuroendocrine lineage cells was promoted by adding DAPT, a Notch pathway inhibitor. The induced MCACs demonstrated motile cilia with a "9 + 2" microtubule arrangement and dynein arms capable of beating and generating flow for mucociliary transport. This method is expected to be useful for future studies on human airway disease modeling and regenerative medicine. PMID:26724905

  14. Physical characterization and profiling of airway epithelial derived exosomes using light scattering.

    PubMed

    Kesimer, Mehmet; Gupta, Richa

    2015-10-01

    Exosomes and other extracellular vesicles have been gaining interest during the last decade due to their emerging role in biology and, disease pathogenesis and their biomarker potential. Almost all published research related to exosomes and other extracellular vesicles include some form of physical characterization. Therefore, these vesicles should be precisely profiled and characterized physically before studying their biological role as intercellular messengers, biomarkers or therapeutic tools. Using a combination of light scattering techniques, including dynamic light scattering (DLS) and multi-angle laser light scattering combined with size exclusion separation (SEC-MALLS), we physically characterized and compared distinct extracellular vesicles derived from the apical secretions of two different cultured airway epithelial cells. The results indicated that epithelial cells release vesicles with distinct physical properties and sizes. Human primary tracheobronchial cell culture (HTBE) derived vesicles have a hydrodynamic radius (Rh) of approximately 340 nm while their radius of gyration (Rg) is approximately 200 nm. Electron microscopy analysis, however, revealed that their spherical component is 40-100 nm in size, and they carry filamentous, entangled membrane mucins on their surface that increases their overall radius. The mucin decoration on the surface defines their size and charge as measured using light scattering techniques. Their surface properties mirror the properties of the cells from which they are derived. This may provide a unique tool for researchers to elucidate the unanswered questions in normal airway biology and innate and adaptive defense, including the remodeling of airways during inflammation, tumorigenesis and metastasis. PMID:25823850

  15. Antimicrobial Peptide P60.4Ac-Containing Creams and Gel for Eradication of Methicillin-Resistant Staphylococcus aureus from Cultured Skin and Airway Epithelial Surfaces.

    PubMed

    Haisma, Elisabeth M; Göblyös, Anikó; Ravensbergen, Bep; Adriaans, Alwin E; Cordfunke, Robert A; Schrumpf, Jasmijn; Limpens, Ronald W A L; Schimmel, Kirsten J M; den Hartigh, Jan; Hiemstra, Pieter S; Drijfhout, Jan Wouter; El Ghalbzouri, Abdoelwaheb; Nibbering, Peter H

    2016-07-01

    We previously found the LL-37-derived peptide P60.4Ac to be effective against methicillin-resistant Staphylococcus aureus (MRSA) on human epidermal models (EMs). The goal of this study was to identify the preferred carrier for this peptide for topical application on skin and mucosal surfaces. We prepared P60.4Ac in three formulations, i.e., a water-in-oil cream with lanolin (Softisan 649), an oil-in-water cream with polyethylene glycol hexadecyl ether (Cetomacrogol), and a hydroxypropyl methylcellulose (hypromellose) 4000 gel. We tested the antimicrobial efficacy of the peptide in these formulations against mupirocin-resistant and -sensitive MRSA strains on EMs and bronchial epithelial models (BEMs). The cytotoxic effects of formulated P60.4Ac on these models were determined using histology and WST-1 and lactate dehydrogenase assays. Moreover, we assessed the stability of the peptide in these formulations with storage for up to 3 months. Killing of MRSA by P60.4Ac in the two creams was less effective than that by P60.4Ac in the hypromellose gel. In agreement with those findings, P60.4Ac in the hypromellose gel was highly effective in eradicating the two MRSA strains from EMs. We found that even 0.1% (wt/wt) P60.4Ac in the hypromellose gel killed >99% of the viable planktonic bacteria and >85% of the biofilm-associated bacteria on EMs. Hypromellose gels containing 0.1% and 0.5% (wt/wt) P60.4Ac effectively reduced the numbers of viable MRSA cells from BEMs by >90%. No cytotoxic effects of P60.4Ac in the hypromellose gel with up to 2% (wt/wt) P60.4Ac on keratinocytes in EMs and in the hypromellose gel with up to 0.5% (wt/wt) P60.4Ac on epithelial cells in BEMs were observed. High-performance liquid chromatography analysis showed that P60.4Ac was stable in the Softisan cream and the hypromellose gel but not in the Cetomacrogol cream. We conclude that P60.4Ac formulated in hypromellose gel is both stable and highly effective in eradicating MRSA from colonized EMs and

  16. Plasticity of Airway Epithelial Cell Transcriptome in Response to Flagellin

    PubMed Central

    Clark, Joan G.; Kim, Kyoung-Hee; Basom, Ryan S.; Gharib, Sina A.

    2015-01-01

    Airway epithelial cells (AEC) are critical components of the inflammatory and immune response during exposure to pathogens. AECs in monolayer culture and differentiated epithelial cells in air-liquid interface (ALI) represent two distinct and commonly used in vitro models, yet differences in their response to pathogens have not been investigated. In this study, we compared the transcriptional effects of flagellin on AECs in monolayer culture versus ALI culture using whole-genome microarrays and RNA sequencing. We exposed monolayer and ALI AEC cultures to flagellin in vitro and analyzed the transcriptional response by microarray and RNA-sequencing. ELISA and RT-PCR were used to validate changes in select candidates. We found that AECs cultured in monolayer and ALI have strikingly different transcriptional states at baseline. When challenged with flagellin, monolayer AEC cultures greatly increased transcription of numerous genes mapping to wounding response, immunity and inflammatory response. In contrast, AECs in ALI culture had an unexpectedly muted response to flagellin, both in number of genes expressed and relative enrichment of inflammatory and immune pathways. We conclude that in vitro culturing methods have a dramatic effect on the transcriptional profile of AECs at baseline and after stimulation with flagellin. These differences suggest that epithelial responses to pathogen challenges are distinctly different in culture models of intact and injured epithelium. PMID:25668187

  17. Plasticity of airway epithelial cell transcriptome in response to flagellin.

    PubMed

    Clark, Joan G; Kim, Kyoung-Hee; Basom, Ryan S; Gharib, Sina A

    2015-01-01

    Airway epithelial cells (AEC) are critical components of the inflammatory and immune response during exposure to pathogens. AECs in monolayer culture and differentiated epithelial cells in air-liquid interface (ALI) represent two distinct and commonly used in vitro models, yet differences in their response to pathogens have not been investigated. In this study, we compared the transcriptional effects of flagellin on AECs in monolayer culture versus ALI culture using whole-genome microarrays and RNA sequencing. We exposed monolayer and ALI AEC cultures to flagellin in vitro and analyzed the transcriptional response by microarray and RNA-sequencing. ELISA and RT-PCR were used to validate changes in select candidates. We found that AECs cultured in monolayer and ALI have strikingly different transcriptional states at baseline. When challenged with flagellin, monolayer AEC cultures greatly increased transcription of numerous genes mapping to wounding response, immunity and inflammatory response. In contrast, AECs in ALI culture had an unexpectedly muted response to flagellin, both in number of genes expressed and relative enrichment of inflammatory and immune pathways. We conclude that in vitro culturing methods have a dramatic effect on the transcriptional profile of AECs at baseline and after stimulation with flagellin. These differences suggest that epithelial responses to pathogen challenges are distinctly different in culture models of intact and injured epithelium. PMID:25668187

  18. Klebsiella pneumoniae Is Able to Trigger Epithelial-Mesenchymal Transition Process in Cultured Airway Epithelial Cells

    PubMed Central

    Leone, Laura; Mazzetta, Francesca; Martinelli, Daniela; Valente, Sabatino; Alimandi, Maurizio; Raffa, Salvatore; Santino, Iolanda

    2016-01-01

    The ability of some bacterial pathogens to activate Epithelial-Mesenchymal Transition normally is a consequence of the persistence of a local chronic inflammatory response or depends on a direct interaction of the pathogens with the host epithelial cells. In this study we monitored the abilities of the K. pneumoniae to activate the expression of genes related to EMT-like processes and the occurrence of phenotypic changes in airway epithelial cells during the early steps of cell infection. We describe changes in the production of intracellular reactive oxygen species and increased HIF-1α mRNA expression in cells exposed to K. pneumoniae infection. We also describe the upregulation of a set of transcription factors implicated in the EMT processes, such as Twist, Snail and ZEB, indicating that the morphological changes of epithelial cells already appreciable after few hours from the K. pneumoniae infection are tightly regulated by the activation of transcriptional pathways, driving epithelial cells to EMT. These effects appear to be effectively counteracted by resveratrol, an antioxidant that is able to exert a sustained scavenging of the intracellular ROS. This is the first report indicating that strains of K. pneumoniae may promote EMT-like programs through direct interaction with epithelial cells without the involvement of inflammatory cells. PMID:26812644

  19. Airway Epithelial NF-κB Activation Promotes Mycoplasma pneumoniae Clearance in Mice

    PubMed Central

    Jiang, Di; Nelson, Mark L.; Gally, Fabienne; Smith, Sean; Wu, Qun; Minor, Maisha; Case, Stephanie; Thaikoottathil, Jyoti; Chu, Hong Wei

    2012-01-01

    Background/Objective Respiratory infections including atypical bacteria Mycoplasma pneumoniae (Mp) contribute to the pathobiology of asthma and chronic obstructive pulmonary disease (COPD). Mp infection mainly targets airway epithelium and activates various signaling pathways such as nuclear factor κB (NF-κB). We have shown that short palate, lung, and nasal epithelium clone 1 (SPLUNC1) serves as a novel host defense protein and is up-regulated upon Mp infection through NF-κB activation in cultured human and mouse primary airway epithelial cells. However, the in vivo role of airway epithelial NF-κB activation in host defense against Mp infection has not been investigated. In the current study, we investigated the effects of in vivo airway epithelial NF-κB activation on lung Mp clearance and its association with airway epithelial SPLUNC1 expression. Methodology/Main Results Non-antimicrobial tetracycline analog 9-t-butyl doxycycline (9-TB) was initially optimized in mouse primary tracheal epithelial cell culture, and then utilized to induce in vivo airway epithelial specific NF-κB activation in conditional NF-κB transgenic mice (CC10-CAIKKβ) with or without Mp infection. Lung Mp load and inflammation were evaluated, and airway epithelial SPLUNC1 protein was examined by immunohistochemistry. We found that 9-TB treatment in NF-κB transgene positive (Tg+), but not transgene negative (Tg−) mice significantly reduced lung Mp load. Moreover, 9-TB increased airway epithelial SPLUNC1 protein expression in NF-κB Tg+ mice. Conclusion By using the non-antimicrobial 9-TB, our study demonstrates that in vivo airway epithelial NF-κB activation promotes lung bacterial clearance, which is accompanied by increased epithelial SPLUNC1 expression. PMID:23285237

  20. Impaired Capacity of Fibroblasts to Support Airway Epithelial Progenitors in Bronchiolitis Obliterans Syndrome

    PubMed Central

    Zhang, Su-Bei; Sun, Xin; Wu, Qi; Wu, Jun-Ping; Chen, Huai-Yong

    2016-01-01

    Background: Bronchiolitis obliterans syndrome (BOS) often develops in transplant patients and results in injury to the respiratory and terminal airway epithelium. Owing to its rising incidence, the pathogenesis of BOS is currently an area of intensive research. Studies have shown that injury to the respiratory epithelium results in dysregulation of epithelial repair. Airway epithelial regeneration is supported by stromal cells, including fibroblasts. This study aimed to investigate whether the supportive role of lung fibroblasts is altered in BOS. Methods: Suspensions of lung cells were prepared by enzyme digestion. Lung progenitor cells (LPCs) were separated by fluorescence-activated cell sorting. Lung fibroblasts from patients with BOS or healthy controls were mixed with sorted mouse LPCs to compare the colony-forming efficiency of LPCs by counting the number of colonies with a diameter of ≥50 μm in each culture. Statistical analyses were performed using the SPSS 17.0 software (SPSS Inc., USA). The paired Student's t-test was used to test for statistical significance. Results: LPCs were isolated with the surface phenotype of CD31- CD34- CD45- EpCAM+ Sca-1+. The colony-forming efficiency of LPCs was significantly reduced when co-cultured with fibroblasts isolated from patients with BOS. The addition of SB431542 increased the colony-forming efficiency of LPCs to 1.8%; however, it was still significantly less than that in co-culture with healthy control fibroblasts (P < 0.05). Conclusion: The epithelial-supportive capacity of fibroblasts is impaired in the development of BOS and suggest that inefficient repair of airway epithelium could contribute to persistent airway inflammation in BOS. PMID:27569228

  1. Regulation of human airway surface liquid.

    PubMed

    Widdicombe, J H; Widdicombe, J G

    1995-01-01

    Human airways are lined with a film of liquid from 5-100 microns in depth, consisting of a periciliary sol around and a mucous gel above the cilia. Microscopical studies have shown the sol to be invariably the same depth as the length of the cilia, and we discuss possible reasons for this. The composition and sources of the airway surface liquid are also described. In addition the forces regulating its volume are analyzed. Several airway diseases are characterised by dramatic changes in the volume and composition of airway liquid. We review recent research suggesting that the accumulation of airway mucous secretions in cystic fibrosis is caused by alterations in active transport of ions and water across both the surface and gland epithelia. PMID:7740210

  2. ATP7B detoxifies silver in ciliated airway epithelial cells

    SciTech Connect

    Ibricevic, Aida; Brody, Steven L.; Youngs, Wiley J.; Cannon, Carolyn L.

    2010-03-15

    Silver is a centuries-old antibiotic agent currently used to treat infected burns. The sensitivity of a wide range of drug-resistant microorganisms to silver killing suggests that it may be useful for treating refractory lung infections. Toward this goal, we previously developed a methylated caffeine silver acetate compound, SCC1, that exhibits broad-spectrum antimicrobial activity against clinical strains of bacteria in vitro and when nebulized to lungs in mouse infection models. Preclinical testing of high concentrations of SCC1 in primary culture mouse tracheal epithelial cells (mTEC) showed selective ciliated cell death. Ciliated cell death was induced by both silver- and copper-containing compounds but not by the methylated caffeine portion of SCC1. We hypothesized that copper transporting P-type ATPases, ATP7A and ATP7B, play a role in silver detoxification in the airway. In mTEC, ATP7A was expressed in non-ciliated cells, whereas ATP7B was expressed only in ciliated cells. The exposure of mTEC to SCC1 induced the trafficking of ATP7B, but not ATP7A, suggesting the presence of a cell-specific silver uptake and detoxification mechanisms. Indeed, the expression of the copper uptake protein CTR1 was also restricted to ciliated cells. A role of ATP7B in silver detoxification was further substantiated when treatment of SCC1 significantly increased cell death in ATP7B shRNA-treated HepG2 cells. In addition, mTEC from ATP7B{sup -/-} mice showed enhanced loss of ciliated cells compared to wild type. These studies are the first to demonstrate a cell type-specific expression of the Ag{sup +}/Cu{sup +} transporters ATP7A, ATP7B, and CTR1 in airway epithelial cells and a role for ATP7B in detoxification of these metals in the lung.

  3. Redox warfare between airway epithelial cells and Pseudomonas: dual oxidase versus pyocyanin.

    PubMed

    Rada, Balázs; Leto, Thomas L

    2009-01-01

    The importance of reactive oxygen species-dependent microbial killing by the phagocytic cell NADPH oxidase has been appreciated for some time, although only recently has an appreciation developed for the partnership of lactoperoxidase with related dual oxidases (Duox) within secretions of the airway surface layer. This system produces mild oxidants designed for extracellular killing that are effective against several airway pathogens, including Staphylococcus aureus, Burkholderia cepacia, and Pseudomonas aeruginosa. Establishment of chronic pseudomonas infections involves adaptations to resist oxidant-dependent killing by expression of a redox-active virulence factor, pyocyanin, that competitively inhibits epithelial Duox activity by consuming intracellular NADPH and producing superoxide, thereby inflicting oxidative stress on the host. PMID:18979077

  4. Pseudomonas pyocyanine alters calcium signaling in human airway epithelial cells.

    PubMed

    Denning, G M; Railsback, M A; Rasmussen, G T; Cox, C D; Britigan, B E

    1998-06-01

    Pseudomonas aeruginosa, an opportunistic human pathogen, causes both acute and chronic lung disease. P. aeruginosa exerts many of its pathophysiological effects by secreting virulence factors, including pyocyanine, a redox-active compound that increases intracellular oxidant stress. Because oxidant stress has been shown to affect cytosolic Ca2+ concentration ([Ca2+]c) in other cell types, we studied the effect of pyocyanine on [Ca2+]c in human airway epithelial cells (A549 and HBE). At lower concentrations, pyocyanine inhibits inositol 1,4,5-trisphosphate formation and [Ca2+]c increases in response to G protein-coupled receptor agonists. Conversely, at higher concentrations, pyocyanine itself increases [Ca2+]c. The pyocyanine-dependent [Ca2+]c increase appears to be oxidant dependent and to result from increased inositol trisphosphate and release of Ca2+ from intracellular stores. Ca2+ plays a central role in epithelial cell function, including regulation of ion transport, mucus secretion, and ciliary beat frequency. By disrupting Ca2+ homeostasis, pyocyanine could interfere with these critical functions and contribute to the pathophysiological effects observed in Pseudomonas-associated lung disease. PMID:9609727

  5. Radical-containing ultrafine particulate matter initiates epithelial-to-mesenchymal transitions in airway epithelial cells.

    PubMed

    Thevenot, Paul T; Saravia, Jordy; Jin, Nili; Giaimo, Joseph D; Chustz, Regina E; Mahne, Sarah; Kelley, Matthew A; Hebert, Valeria Y; Dellinger, Barry; Dugas, Tammy R; Demayo, Francesco J; Cormier, Stephania A

    2013-02-01

    Environmentally persistent free radicals (EPFRs) in combustion-generated particulate matter (PM) are capable of inducing pulmonary pathologies and contributing to the development of environmental asthma. In vivo exposure of infant rats to EPFRs demonstrates their ability to induce airway hyperresponsiveness to methacholine, a hallmark of asthma. However, the mechanisms by which combustion-derived EPFRs elicit in vivo responses remain elusive. In this study, we used a chemically defined EPFR consisting of approximately 0.2 μm amorphrous silica containing 3% cupric oxide with the organic pollutant 1,2-dichlorobenzene (DCB-230). DCB-230 possesses similar radical content to urban-collected EPFRs but offers several advantages, including lack of contaminants and chemical uniformity. DCB-230 was readily taken up by BEAS-2B and at high doses (200 μg/cm(2)) caused substantial necrosis. At low doses (20 μg/cm(2)), DCB-230 particles caused lysosomal membrane permeabilization, oxidative stress, and lipid peroxidation within 24 hours of exposure. During this period, BEAS-2B underwent epithelial-to-mesenchymal transition (EMT), including loss of epithelial cell morphology, decreased E-cadherin expression, and increased α-smooth muscle actin (α-SMA) and collagen I production. Similar results were observed in neonatal air-liquid interface culture (i.e., disruption of epithelial integrity and EMT). Acute exposure of infant mice to DCB-230 resulted in EMT, as confirmed by lineage tracing studies and evidenced by coexpression of epithelial E-cadherin and mesenchymal α-SMA proteins in airway cells and increased SNAI1 expression in the lungs. EMT in neonatal mouse lungs after EPFR exposure may provide an explanation for epidemiological evidence supporting PM exposure and increased risk of asthma. PMID:23087054

  6. Epithelial cell deformation during surfactant-mediated airway reopening: a theoretical model.

    PubMed

    Naire, Shailesh; Jensen, Oliver E

    2005-08-01

    A theoretical model is presented describing the reopening by an advancing air bubble of an initially liquid-filled collapsed airway lined with deformable epithelial cells. The model integrates descriptions of flow-structure interaction (accounting for nonlinear deformation of the airway wall and viscous resistance of the airway liquid flow), surfactant transport around the bubble tip (incorporating physicochemical parameters appropriate for Infasurf), and cell deformation (due to stretching of the airway wall and airway liquid flows). It is shown how the pressure required to drive a bubble into a flooded airway, peeling apart the wet airway walls, can be reduced substantially by surfactant, although the effectiveness of Infasurf is limited by slow adsorption at high concentrations. The model demonstrates how the addition of surfactant can lead to the spontaneous reopening of a collapsed airway, depending on the degree of initial airway collapse. The effective elastic modulus of the epithelial layer is shown to be a key determinant of the relative magnitude of strains generated by flow-induced shear stresses and by airway wall stretch. The model also shows how epithelial-layer compressibility can mediate strains arising from flow-induced normal stresses and stress gradients. PMID:15802368

  7. SAFETY AND EFFICIENCY OF MODULATING PARACELLULAR PERMEABILITY TO ENHANCE AIRWAY EPITHELIAL GENE TRANSFER IN VIVO

    EPA Science Inventory


    ABSTRACT

    We evaluated the safety of agents that enhance gene transfer by modulating paracellular permeability. Lactate dehydrogenase (LDH) and cytokine release were measured in polarized primary human airway epithelial (HAE) cells after luminal application of vehicle, ...

  8. Airway Surface Dehydration Aggravates Cigarette Smoke-Induced Hallmarks of COPD in Mice

    PubMed Central

    Seys, Leen J. M.; Verhamme, Fien M.; Dupont, Lisa L.; Desauter, Elke; Duerr, Julia; Seyhan Agircan, Ayca; Conickx, Griet; Joos, Guy F.; Brusselle, Guy G.

    2015-01-01

    Introduction Airway surface dehydration, caused by an imbalance between secretion and absorption of ions and fluid across the epithelium and/or increased epithelial mucin secretion, impairs mucociliary clearance. Recent evidence suggests that this mechanism may be implicated in chronic obstructive pulmonary disease (COPD). However, the role of airway surface dehydration in the pathogenesis of cigarette smoke (CS)-induced COPD remains unknown. Objective We aimed to investigate in vivo the effect of airway surface dehydration on several CS-induced hallmarks of COPD in mice with airway-specific overexpression of the β-subunit of the epithelial Na+ channel (βENaC). Methods βENaC-Tg mice and wild-type (WT) littermates were exposed to air or CS for 4 or 8 weeks. Pathological hallmarks of COPD, including goblet cell metaplasia, mucin expression, pulmonary inflammation, lymphoid follicles, emphysema and airway wall remodelling were determined and lung function was measured. Results Airway surface dehydration in βENaC-Tg mice aggravated CS-induced airway inflammation, mucin expression and destruction of alveolar walls and accelerated the formation of pulmonary lymphoid follicles. Moreover, lung function measurements demonstrated an increased compliance and total lung capacity and a lower resistance and hysteresis in βENaC-Tg mice, compared to WT mice. CS exposure further altered lung function measurements. Conclusions We conclude that airway surface dehydration is a risk factor that aggravates CS-induced hallmarks of COPD. PMID:26066648

  9. Generation of airway epithelial cells with native characteristics from mouse induced pluripotent stem cells.

    PubMed

    Yoshie, Susumu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Ikeda, Masakazu; Nomoto, Yukio; Wada, Ikuo; Omori, Koichi

    2016-05-01

    Airway epithelial cells derived from induced pluripotent stem (iPS) cells are expected to be a useful source for the regeneration of airway epithelium. Our preliminary study of embryoid body (EB) formation and the air-liquid interface (ALI) method suggested that mouse iPS cells can differentiate into airway epithelial cells. However, whether the cells generated from mouse iPS cells had the character and phenotype of native airway epithelial cells remained uninvestigated. In this study, we generated airway epithelial cells from EBs by culturing them under serum-free conditions supplemented with Activin and bFGF and by the ALI method and characterized the iPS cell-derived airway epithelial cells in terms of their gene expression, immunoreactivity, morphology, and function. Analysis by quantitative real-time reverse transcription-polymerase chain reaction(RT-PCR) revealed that the expression of the undifferentiated cell marker Nanog decreased time-dependently after the induction of differentiation, whereas definitive endoderm markers Foxa2 and Cxcr4 were transiently up-regulated. Thereafter, the expression of airway epithelium markers such as Tubb4a, Muc5ac, and Krt5 was detected by RT-PCR and immunostaining. The formation of tight junctions was also confirmed by immunostaining and permeability assay. Analysis by hematoxylin and eosin staining and scanning electron microscopy indicated that the cells generated from mouse iPS cells formed airway-epithelium-like tissue and had cilia, the movement of which was visualized and observed to be synchronized. These results demonstrate that the airway epithelial cells generated by our method have native characteristics and open new perspectives for the regeneration of injured airway epithelium. PMID:26590823

  10. AMPK agonists ameliorate sodium and fluid transport and inflammation in cystic fibrosis airway epithelial cells.

    PubMed

    Myerburg, Michael M; King, J Darwin; Oyster, Nicholas M; Fitch, Adam C; Magill, Amy; Baty, Catherine J; Watkins, Simon C; Kolls, Jay K; Pilewski, Joseph M; Hallows, Kenneth R

    2010-06-01

    The metabolic sensor AMP-activated kinase (AMPK) inhibits both the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) Cl(-) channel and epithelial Na(+) channel (ENaC), and may inhibit secretion of proinflammatory cytokines in epithelia. Here we have tested in primary polarized CF and non-CF human bronchial epithelial (HBE) cells the effects of AMPK activators, metformin and 5-aminoimidazole-4-carboxamide-1-beta-D-riboside (AICAR), on various parameters that contribute to CF lung disease: ENaC-dependent short-circuit currents (I(sc)), airway surface liquid (ASL) height, and proinflammatory cytokine secretion. AMPK activation after overnight treatment with either metformin (2-5 mM) or AICAR (1 mM) substantially inhibited ENaC-dependent I(sc) in both CF and non-CF airway cultures. Live-cell confocal images acquired 60 minutes after apical addition of Texas Red-dextran-containing fluid revealed significantly greater ASL heights after AICAR and metformin treatment relative to controls, suggesting that AMPK-dependent ENaC inhibition slows apical fluid reabsorption. Both metformin and AICAR decreased secretion of various proinflammatory cytokines, both with and without prior LPS stimulation. Finally, prolonged exposure to more physiologically relevant concentrations of metformin (0.03-1 mM) inhibited ENaC currents and decreased proinflammatory cytokine levels in CF HBE cells in a dose-dependent manner. These findings suggest that novel therapies to activate AMPK in the CF airway may be beneficial by blunting excessive sodium and ASL absorption and by reducing excessive airway inflammation, which are major contributors to CF lung disease. PMID:19617399

  11. OZONE-INDUCED RELEASE OF CYTOKINES AND FIBRONECTIN BY ALVEOLAR MACROPHAGES AND AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Although airway epithelial cells appear damaged following exposure of humans and animals to ozone, the contribution of these cells to inflammation observed after ozone exposure is unclear. ince human airway cells are infrequently available for in vitro studies, we have investigat...

  12. Alternaria extract activates autophagy that induces IL-18 release from airway epithelial cells.

    PubMed

    Murai, Hiroki; Okazaki, Shintaro; Hayashi, Hisako; Kawakita, Akiko; Hosoki, Koa; Yasutomi, Motoko; Sur, Sanjiv; Ohshima, Yusei

    2015-09-01

    Alternaria alternata is a major outdoor allergen that causes allergic airway diseases. Alternaria extract (ALT-E) has been shown to induce airway epithelial cells to release IL-18 and thereby initiate Th2-type responses. We investigated the underlying mechanisms involved in IL-18 release from ALT-E-stimulated airway epithelial cells. Normal human bronchial epithelial cells and A549 human lung adenocarcinoma cells were stimulated with ALT-E in the presence of different inhibitors of autophagy or caspases. IL-18 levels in culture supernatants were measured by ELISA. The numbers of autophagosomes, an LC3-I to LC3-II conversion, and p62 degradation were determined by immunofluorescence staining and immunoblotting. 3-methyladenine and bafilomycin, which inhibit the formation of preautophagosomal structures and autolysosomes, respectively, suppressed ALT-E-induced IL-18 release by cells, whereas caspase 1 and 8 inhibitors did not. ALT-E-stimulation increased autophagosome formation, LC-3 conversion, and p62 degradation in airway epithelial cells. LPS-stimulation induced the LC3 conversion in A549 cells, but did not induce IL-18 release or p62 degradation. Unlike LPS, ALT-E induced airway epithelial cells to release IL-18 via an autophagy dependent, caspase 1 and 8 independent pathway. Although autophagy has been shown to negatively regulate canonical inflammasome activity in TLR-stimulated macrophages, our data indicates that this process is an unconventional mechanism of IL-18 secretion by airway epithelial cells. PMID:26032499

  13. REGIONAL DIFFERENCES IN AIRWAY SURFACE LIQUID COMPOSITION

    EPA Science Inventory

    Liquid from canine airway surfaces was absorbed onto filter paper strips and analyzed. In resting conditions, tracheal surface liquid was hyperosmolal (330 mosmol/kg H2O) compared to plasma with raised Na(+1) (158 meq/l), Cl(-1) (134 meq/l), K(-1) (28 meq/l), and HCO3(-1) (32 meq...

  14. 17β-Estradiol inhibits Ca2+-dependent homeostasis of airway surface liquid volume in human cystic fibrosis airway epithelia

    PubMed Central

    Coakley, Ray D.; Sun, Hengrui; Clunes, Lucy A.; Rasmussen, Julia E.; Stackhouse, James R.; Okada, Seiko F.; Fricks, Ingrid; Young, Steven L.; Tarran, Robert

    2008-01-01

    Normal airways homeostatically regulate the volume of airway surface liquid (ASL) through both cAMP- and Ca2+-dependent regulation of ion and water transport. In cystic fibrosis (CF), a genetic defect causes a lack of cAMP-regulated CFTR activity, leading to diminished Cl– and water secretion from airway epithelial cells and subsequent mucus plugging, which serves as the focus for infections. Females with CF exhibit reduced survival compared with males with CF, although the mechanisms underlying this sex-related disadvantage are unknown. Despite the lack of CFTR, CF airways retain a limited capability to regulate ASL volume, as breathing-induced ATP release activates salvage purinergic pathways that raise intracellular Ca2+ concentration to stimulate an alternate pathway to Cl– secretion. We hypothesized that estrogen might affect this pathway by reducing the ability of airway epithelia to respond appropriately to nucleotides. We found that uridine triphosphate–mediated (UTP-mediated) Cl– secretion was reduced during the periovulatory estrogen maxima in both women with CF and normal, healthy women. Estrogen also inhibited Ca2+ signaling and ASL volume homeostasis in non-CF and CF airway epithelia by attenuating Ca2+ influx. This inhibition of Ca2+ signaling was prevented and even potentiated by estrogen antagonists such as tamoxifen, suggesting that antiestrogens may be beneficial in the treatment of CF lung disease because they increase Cl– secretion in the airways. PMID:19033671

  15. Regulation of local immunity by airway epithelial cells.

    PubMed

    Mayer, Anja K; Dalpke, Alexander H

    2007-01-01

    Epithelial cells are the first line of defense against invading microbial pathogens. They are important contributors to innate mucosal immunity and generate various and sophisticated anti-microbial defense mechanisms, including the formation of a tight barrier and secretion of anti-microbial substances as well as inflammatory mediators. To provide these active defense mechanisms, epithelial cells functionally express various pattern-recognition receptors. Toll-like receptors have been shown to recognize conserved microbial patterns mediating inducible activation of innate immunity. Mucosal surfaces, however, are prone to contact with pathogenic as well as non-pathogenic microbes and, therefore, immune-recognition principles have to be strictly regulated to avoid uncontrolled permanent activation. This review will focus on mechanisms by which epithelial cells regulate mucosal immune responses, thus creating an organ-specific microenvironment. This includes local adaptations in microbial recognition, regulation of local immune homeostasis, and modulation of antigen-presenting cells and adaptive immune responses. These regulatory mechanisms serve the special needs of controlled microbial recognition in mucosal compartments. PMID:18060372

  16. Agonist binding to β-adrenergic receptors on human airway epithelial cells inhibits migration and wound repair.

    PubMed

    Peitzman, Elizabeth R; Zaidman, Nathan A; Maniak, Peter J; O'Grady, Scott M

    2015-12-15

    Human airway epithelial cells express β-adrenergic receptors (β-ARs), which regulate mucociliary clearance by stimulating transepithelial anion transport and ciliary beat frequency. Previous studies using airway epithelial cells showed that stimulation with isoproterenol increased cell migration and wound repair by a cAMP-dependent mechanism. In the present study, impedance-sensing arrays were used to measure cell migration and epithelial restitution following wounding of confluent normal human bronchial epithelial (NHBE) and Calu-3 cells by electroporation. Stimulation with epinephrine or the β2-AR-selective agonist salbutamol significantly delayed wound closure and reduced the mean surface area of lamellipodia protruding into the wound. Treatment with the β-AR bias agonist carvedilol or isoetharine also produced a delay in epithelial restitution similar in magnitude to epinephrine and salbutamol. Measurements of extracellular signal-regulated kinase phosphorylation following salbutamol or carvedilol stimulation showed no significant change in the level of phosphorylation compared with untreated control cells. However, inhibition of protein phosphatase 2A activity completely blocked the delay in wound closure produced by β-AR agonists. In Calu-3 cells, where CFTR expression was inhibited by RNAi, salbutamol did not inhibit wound repair, suggesting that β-AR agonist stimulation and loss of CFTR function share a common pathway leading to inhibition of epithelial repair. Confocal images of the basal membrane of Calu-3 cells labeled with anti-β1-integrin (clone HUTS-4) antibody showed that treatment with epinephrine or carvedilol reduced the level of activated integrin in the membrane. These findings suggest that treatment with β-AR agonists delays airway epithelial repair by a G protein- and cAMP-independent mechanism involving protein phosphatase 2A and a reduction in β1-integrin activation in the basal membrane. PMID:26491049

  17. Ozonolysis products of membrane fatty acids activate eicosanoid metabolism in human airway epithelial cells

    SciTech Connect

    Leikauf, G.D.; Zhao, Q.; Zhou, S.; Santrock, J. )

    1993-12-01

    When inhaled, ozone reacts at the airway luminal surface with unsaturated fatty acids contained in the extracellular fluid and plasma membrane to form an aldehyde and hydroxyhydroperoxide. The resulting hydroxyhydroperoxide degrades in aqueous systems to yield a second aldehyde and hydrogen peroxide (H2O2). Previously, we demonstrated that ozone can augment eicosanoid metabolism in bovine airway epithelial cells. To examine structure-activity relationships of ozone-fatty acid degradation products on eicosanoid metabolism in human airway epithelial cells, 3-, 6-, and 9-carbon saturated aldehydes and hydroxyhydroperoxides were synthesized and purified. Eicosanoid metabolism was evaluated by determination of total 3H-activity release from confluent cells previously incubated with [3H]arachidonic acid and by identification of specific metabolites with high performance liquid chromatography and radioimmunoassay. The major metabolites detected were prostaglandin E2, prostaglandin F2 alpha, and 15-hydroxyeicosatetraenoic acid. The 9-carbon aldehyde, nonanal, in contrast to 3- or 6-carbon aldehydes, stimulated release at concentrations > or = 100 microM, suggesting that the stimulatory effect increases with increasing chain length. When tested under identical conditions, the 3-, 6-, and 9-carbon hydroxyhydroperoxides were more potent than the corresponding aldehydes. Again, a greater effect was noted when the chain length was increased. One possible explanation for the increased potency of the hydroxyhydroperoxides over the aldehydes could be due to degradation of the hydroxyhydroperoxide into H2O2 and aldehyde. We consider this an unlikely explanation because responses varied with chain length (although each hydroxyhydroperoxide would produce an equivalent amount of H2O2) and because exposure to H2O2 alone or H2O2 plus hexanal produced a response dissimilar to 1-hydroxy-1-hexanehydroperoxide.

  18. Generation of ESC-derived Mouse Airway Epithelial Cells Using Decellularized Lung Scaffolds.

    PubMed

    Shojaie, Sharareh; Lee, Joyce; Wang, Jinxia; Ackerley, Cameron; Post, Martin

    2016-01-01

    Lung lineage differentiation requires integration of complex environmental cues that include growth factor signaling, cell-cell interactions and cell-matrix interactions. Due to this complexity, recapitulation of lung development in vitro to promote differentiation of stem cells to lung epithelial cells has been challenging. In this protocol, decellularized lung scaffolds are used to mimic the 3-dimensional environment of the lung and generate stem cell-derived airway epithelial cells. Mouse embryonic stem cell are first differentiated to the endoderm lineage using an embryoid body (EB) culture method with activin A. Endoderm cells are then seeded onto decellularized scaffolds and cultured at air-liquid interface for up to 21 days. This technique promotes differentiation of seeded cells to functional airway epithelial cells (ciliated cells, club cells, and basal cells) without additional growth factor supplementation. This culture setup is defined, serum-free, inexpensive, and reproducible. Although there is limited contamination from non-lung endoderm lineages in culture, this protocol only generates airway epithelial populations and does not give rise to alveolar epithelial cells. Airway epithelia generated with this protocol can be used to study cell-matrix interactions during lung organogenesis and for disease modeling or drug-discovery platforms of airway-related pathologies such as cystic fibrosis. PMID:27214388

  19. Intracellular insulin-like growth factor-1 induces Bcl-2 expression in airway epithelial cells.

    PubMed

    Chand, Hitendra S; Harris, Jennifer Foster; Mebratu, Yohannes; Chen, Yangde; Wright, Paul S; Randell, Scott H; Tesfaigzi, Yohannes

    2012-05-01

    Bcl-2, a prosurvival protein, regulates programmed cell death during development and repair processes, and it can be oncogenic when cell proliferation is deregulated. The present study investigated what factors modulate Bcl-2 expression in airway epithelial cells and identified the pathways involved. Microarray analysis of mRNA from airway epithelial cells captured by laser microdissection showed that increased expression of IL-1β and insulin-like growth factor-1 (IGF-1) coincided with induced Bcl-2 expression compared with controls. Treatment of cultured airway epithelial cells with IL-1β and IGF-1 induced Bcl-2 expression by increasing Bcl-2 mRNA stability with no discernible changes in promoter activity. Silencing the IGF-1 expression using short hairpin RNA showed that intracellular IGF-1 (IC-IGF-1) was increasing Bcl-2 expression. Blocking epidermal growth factor receptor or IGF-1R activation also suppressed IC-IGF-1 and abolished the Bcl-2 induction. Induced expression and colocalization of IC-IGF-1 and Bcl-2 were observed in airway epithelial cells of mice exposed to LPS or cigarette smoke and of patients with cystic fibrosis and chronic bronchitis but not in the respective controls. These studies demonstrate that IC-IGF-1 induces Bcl-2 expression in epithelial cells via IGF-1R and epidermal growth factor receptor pathways, and targeting IC-IGF-1 could be beneficial to treat chronic airway diseases. PMID:22461702

  20. Rho-associated protein kinase inhibition enhances airway epithelial Basal-cell proliferation and lentivirus transduction.

    PubMed

    Horani, Amjad; Nath, Aditya; Wasserman, Mollie G; Huang, Tao; Brody, Steven L

    2013-09-01

    The identification of factors that regulate airway epithelial cell proliferation and differentiation are essential for understanding the pathophysiology of airway diseases. Rho-associated protein kinases (ROCKs) are downstream effector proteins of RhoA GTPase that direct the functions of cell cytoskeletal proteins. ROCK inhibition with Y27632 has been shown to enhance the survival and cloning of human embryonic stem cells and pluripotent cells in other tissues. We hypothesized that Y27632 treatment exerts a similar effect on airway epithelial basal cells, which function as airway epithelial progenitor cells. Treatment with Y27632 enhanced basal-cell proliferation in cultured human tracheobronchial and mouse tracheal epithelial cells. ROCK inhibition accelerated the maturation of basal cells, characterized by a diminution of the cell size associated with cell compaction and the expression of E-cadherin at cell-cell junctions. Transient treatment of cultured basal cells with Y27632 did not affect subsequent ciliated or mucous cell differentiation under air-liquid interface conditions, and allowed for the initial use of lower numbers of human or mouse primary airway epithelial cells than otherwise possible. Moreover, the use of Y27632 during lentivirus-mediated transduction significantly improved posttransduction efficiency and the selection of a transduced cell population, as determined by reporter gene expression. These findings suggest an important role for ROCKs in the regulation of proliferation and maturation of epithelial basal cells, and demonstrate that the inhibition of ROCK pathways using Y27632 provides an adjunctive tool for the in vitro genetic manipulation of airway epithelial cells by lentivirus vectors. PMID:23713995

  1. XB130 promotes bronchioalveolar stem cell and Club cell proliferation in airway epithelial repair and regeneration

    PubMed Central

    Toba, Hiroaki; Wang, Yingchun; Bai, Xiaohui; Zamel, Ricardo; Cho, Hae-Ra; Liu, Hongmei; Lira, Alonso; Keshavjee, Shaf; Liu, Mingyao

    2015-01-01

    Proliferation of bronchioalveolar stem cells (BASCs) is essential for epithelial repair. XB130 is a novel adaptor protein involved in the regulation of epithelial cell survival, proliferation and migration through the PI3K/Akt pathway. To determine the role of XB130 in airway epithelial injury repair and regeneration, a naphthalene-induced airway epithelial injury model was used with XB130 knockout (KO) mice and their wild type (WT) littermates. In XB130 KO mice, at days 7 and 14, small airway epithelium repair was significantly delayed with fewer number of Club cells (previously called Clara cells). CCSP (Club cell secreted protein) mRNA expression was also significantly lower in KO mice at day 7. At day 5, there were significantly fewer proliferative epithelial cells in the KO group, and the number of BASCs significantly increased in WT mice but not in KO mice. At day 7, phosphorylation of Akt, GSK-3β, and the p85α subunit of PI3K was observed in airway epithelial cells in WT mice, but to a much lesser extent in KO mice. Microarray data also suggest that PI3K/Akt-related signals were regulated differently in KO and WT mice. An inhibitory mechanism for cell proliferation and cell cycle progression was suggested in KO mice. XB130 is involved in bronchioalveolar stem cell and Club cell proliferation, likely through the PI3K/Akt/GSK-3β pathway. PMID:26360608

  2. Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells

    PubMed Central

    Knox, Alan J.

    2015-01-01

    Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production. PMID:26047642

  3. The role of airway epithelial cells and innate immune cells in chronic respiratory disease

    PubMed Central

    Holtzman, Michael J.; Byers, Derek E.; Alexander-Brett, Jennifer; Wang, Xinyu

    2016-01-01

    An abnormal immune response to environmental agents is generally thought to be responsible for causing chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Based on studies of experimental models and human subjects, there is increasing evidence that the response of the innate immune system is crucial for the development of this type of airway disease. Airway epithelial cells and innate immune cells represent key components of the pathogenesis of chronic airway disease and are emerging targets for new therapies. In this Review, we summarize the innate immune mechanisms by which airway epithelial cells and innate immune cells regulate the development of chronic respiratory diseases. We also explain how these pathways are being targeted in the clinic to treat patients with these diseases. PMID:25234144

  4. Expression of IL-4/IL-13 receptors in differentiating human airway epithelial cells.

    PubMed

    White, Steven R; Martin, Linda D; Stern, Randi; Laxman, Bharathi; Marroquin, Bertha A

    2010-11-01

    IL-4 and IL-13 elicit several important responses in airway epithelium including chemokine secretion and mucous secretion that may contribute to airway inflammation, cell migration, and differentiation. These cytokines have overlapping but not identical effector profiles likely due to shared subunits in their receptor complexes. These receptors are variably described in epithelial cells, and the relative expression, localization, and function of these receptors in differentiated and repairing epithelial cells are not clear. We examined IL-4/IL-13 receptor expression and localization in primary airway epithelial cells collected from normal human lungs and grown under conditions yielding both undifferentiated and differentiated cells inclusive of basal, goblet, and ciliated cell phenotypes. Gene expression of the IL-4Rα, IL-2Rγc, IL-13Rα1, and IL-13Rα2 receptor subunits increased with differentiation, but different patterns of localization and protein abundance were seen for each subunit based on both differentiation and the cell subtypes present. Increased expression of receptor subunits observed in more differentiated cells was associated with more substantial functional responses to IL-4 stimulation including increased eotaxin-3 expression and accelerated migration after injury. We demonstrate substantial differences in IL-4/IL-13 receptor subunit expression and responsiveness to IL-4 based on the extent of airway epithelial cell differentiation and suggest that these differences may have functional consequences in airway inflammation. PMID:20729386

  5. Wound repair and anti-oxidative capacity is regulated by ITGB4 in airway epithelial cells.

    PubMed

    Liu, Chi; Liu, Hui-jun; Xiang, Yang; Tan, Yu-rong; Zhu, Xiao-lin; Qin, Xiao-qun

    2010-08-01

    Integrin beta 4 (ITGB4) is a structural adhesion molecule which engages in maintaining the integrity of airway epithelial cells. Its specific cytomembrane structural feature strongly indicates that ITGB4 may engage in many signaling pathways and physiologic processes. However, in addition to adhesion, the specific biologic significance of ITGB4 in airway epithelial cells is almost unknown. In this article, we investigated the expression and functional properties of ITGB4 in airway epithelial cells in vivo and in vitro. Human bronchial epithelial cell line (16HBE14O-cells) and primary rat tracheal epithelial cells (RTE cells) were used to determine ITGB4 expression under ozone tress or mechanical damage, respectively. An ovalbumin (OVA)-challenged asthma model was used to investigate ITGB4 expression after antigen exposure in vivo. In addition, an ITGB4 overexpression vector and ITGB4 silence virus vector were constructed and transfected into RTE cells. Then, wound repair ability and anti-oxidation capacity was evaluated. Our results demonstrated that, on the edge of mechanically wounded cell areas, ITGB4 expression was increased after mechanical injury. After ozone stress, upregulation expression of ITGB4 was also detected. In the OVA-challenged asthma model, ITGB4 expression was decreased on airway epithelial cells accompanying with structural disruption and damage of anti-oxidation capacity. Besides, our study revealed that upregulation of ITGB4 promotes wound repair ability and anti-oxidative ability, while such abilities were blocked when ITGB4 was silenced. Taken together, these results showed that ITGB4 was a new interesting molecule involved in the regulation of wound repair and anti-oxidation processes for airway epithelial cells. PMID:20364299

  6. Influence of airway wall compliance on epithelial cell injury and adhesion during interfacial flows

    PubMed Central

    Higuita-Castro, Natalia; Mihai, Cosmin; Hansford, Derek J.

    2014-01-01

    Interfacial flows during cyclic airway reopening are an important source of ventilator-induced lung injury. However, it is not known how changes in airway wall compliance influence cell injury during airway reopening. We used an in vitro model of airway reopening in a compliant microchannel to investigate how airway wall stiffness influences epithelial cell injury. Epithelial cells were grown on gel substrates with different rigidities, and cellular responses to substrate stiffness were evaluated in terms of metabolic activity, mechanics, morphology, and adhesion. Repeated microbubble propagations were used to simulate cyclic airway reopening, and cell injury and detachment were quantified via live/dead staining. Although cells cultured on softer gels exhibited a reduced elastic modulus, these cells experienced less plasma membrane rupture/necrosis. Cells on rigid gels exhibited a minor, but statistically significant, increase in the power law exponent and also exhibited a significantly larger height-to-length aspect ratio. Previous studies indicate that this change in morphology amplifies interfacial stresses and, therefore, correlates with the increased necrosis observed during airway reopening. Although cells cultured on stiff substrates exhibited more plasma membrane rupture, these cells experienced significantly less detachment and monolayer disruption during airway reopening. Western blotting and immunofluorescence indicate that this protection from detachment and monolayer disruption correlates with increased focal adhesion kinase and phosphorylated paxillin expression. Therefore, changes in cell morphology and focal adhesion structure may govern injury responses during compliant airway reopening. In addition, these results indicate that changes in airway compliance, as occurs during fibrosis or emphysema, may significantly influence cell injury during mechanical ventilation. PMID:25213636

  7. Airway basal stem cells: a perspective on their roles in epithelial homeostasis and remodeling.

    PubMed

    Rock, Jason R; Randell, Scott H; Hogan, Brigid L M

    2010-01-01

    The small airways of the human lung undergo pathological changes in pulmonary disorders, such as chronic obstructive pulmonary disease (COPD), asthma, bronchiolitis obliterans and cystic fibrosis. These clinical problems impose huge personal and societal healthcare burdens. The changes, termed 'pathological airway remodeling', affect the epithelium, the underlying mesenchyme and the reciprocal trophic interactions that occur between these tissues. Most of the normal human airway is lined by a pseudostratified epithelium of ciliated cells, secretory cells and 6-30% basal cells, the proportion of which varies along the proximal-distal axis. Epithelial abnormalities range from hypoplasia (failure to differentiate) to basal- and goblet-cell hyperplasia, squamous- and goblet-cell metaplasia, dysplasia and malignant transformation. Mesenchymal alterations include thickening of the basal lamina, smooth muscle hyperplasia, fibrosis and inflammatory cell accumulation. Paradoxically, given the prevalence and importance of airway remodeling in lung disease, its etiology is poorly understood. This is due, in part, to a lack of basic knowledge of the mechanisms that regulate the differentiation, maintenance and repair of the airway epithelium. Specifically, little is known about the proliferation and differentiation of basal cells, a multipotent stem cell population of the pseudostratified airway epithelium. This Perspective summarizes what we know, and what we need to know, about airway basal cells to evaluate their contributions to normal and abnormal airway remodeling. We contend that exploiting well-described model systems using both human airway epithelial cells and the pseudostratified epithelium of the genetically tractable mouse trachea will enable crucial discoveries regarding the pathogenesis of airway disease. PMID:20699479

  8. Modulation of endocytic trafficking and apical stability of CFTR in primary human airway epithelial cultures.

    PubMed

    Cholon, Deborah M; O'Neal, Wanda K; Randell, Scott H; Riordan, John R; Gentzsch, Martina

    2010-03-01

    CFTR is a highly regulated apical chloride channel of epithelial cells that is mutated in cystic fibrosis (CF). In this study, we characterized the apical stability and intracellular trafficking of wild-type and mutant CFTR in its native environment, i.e., highly differentiated primary human airway epithelial (HAE) cultures. We labeled the apical pool of CFTR and subsequently visualized the protein in intracellular compartments. CFTR moved from the apical surface to endosomes and then efficiently recycled back to the surface. CFTR endocytosis occurred more slowly in polarized than in nonpolarized HAE cells or in a polarized epithelial cell line. The most common mutation in CF, DeltaF508 CFTR, was rescued from endoplasmic reticulum retention by low-temperature incubation but transited from the apical membrane to endocytic compartments more rapidly and recycled less efficiently than wild-type CFTR. Incubation with small-molecule correctors resulted in DeltaF508 CFTR at the apical membrane but did not restore apical stability. To stabilize the mutant protein at the apical membrane, we found that the dynamin inhibitor Dynasore and the cholesterol-extracting agent cyclodextrin dramatically reduced internalization of DeltaF508, whereas the proteasomal inhibitor MG-132 completely blocked endocytosis of DeltaF508. On examination of intrinsic properties of CFTR that may affect its apical stability, we found that N-linked oligosaccharides were not necessary for transport to the apical membrane but were required for efficient apical recycling and, therefore, influenced the turnover of surface CFTR. Thus apical stability of CFTR in its native environment is affected by properties of the protein and modulation of endocytic trafficking. PMID:20008117

  9. Modulation of endocytic trafficking and apical stability of CFTR in primary human airway epithelial cultures

    PubMed Central

    Cholon, Deborah M.; O'Neal, Wanda K.; Randell, Scott H.; Riordan, John R.

    2010-01-01

    CFTR is a highly regulated apical chloride channel of epithelial cells that is mutated in cystic fibrosis (CF). In this study, we characterized the apical stability and intracellular trafficking of wild-type and mutant CFTR in its native environment, i.e., highly differentiated primary human airway epithelial (HAE) cultures. We labeled the apical pool of CFTR and subsequently visualized the protein in intracellular compartments. CFTR moved from the apical surface to endosomes and then efficiently recycled back to the surface. CFTR endocytosis occurred more slowly in polarized than in nonpolarized HAE cells or in a polarized epithelial cell line. The most common mutation in CF, ΔF508 CFTR, was rescued from endoplasmic reticulum retention by low-temperature incubation but transited from the apical membrane to endocytic compartments more rapidly and recycled less efficiently than wild-type CFTR. Incubation with small-molecule correctors resulted in ΔF508 CFTR at the apical membrane but did not restore apical stability. To stabilize the mutant protein at the apical membrane, we found that the dynamin inhibitor Dynasore and the cholesterol-extracting agent cyclodextrin dramatically reduced internalization of ΔF508, whereas the proteasomal inhibitor MG-132 completely blocked endocytosis of ΔF508. On examination of intrinsic properties of CFTR that may affect its apical stability, we found that N-linked oligosaccharides were not necessary for transport to the apical membrane but were required for efficient apical recycling and, therefore, influenced the turnover of surface CFTR. Thus apical stability of CFTR in its native environment is affected by properties of the protein and modulation of endocytic trafficking. PMID:20008117

  10. Ex Vivo and In Vivo Lentivirus-Mediated Transduction of Airway Epithelial Progenitor Cells.

    PubMed

    Leoni, Giulia; Wasowicz, Marguerite Y; Chan, Mario; Meng, Cuixiang; Farley, Raymond; Brody, Steven L; Inoue, Makoto; Hasegawa, Mamoru; Alton, Eric W F W; Griesenbach, Uta

    2015-01-01

    A key challenge in pulmonary gene therapy for cystic fibrosis is to provide long-term correction of the genetic defect. This may be achievable by targeting airway epithelial stem/progenitor cells with an integrating vector. Here, we evaluated the ability of a lentiviral vector, derived from the simian immunodeficiency virus and pseudotyped with F and HN envelope proteins from Sendai virus, to transduce progenitor basal cells of the mouse nasal airways. We first transduced basal cell-enriched cultures ex vivo and confirmed efficient transduction of cytokeratin-5 positive cells. We next asked whether progenitor cells could be transduced in vivo. We evaluated the transduction efficiency in mice pretreated by intranasal administration of polidocanol to expose the progenitor cell layer. Compared to control mice, polidocanol treated mice demonstrated a significant increase in the number of transduced basal cells at 3 and 14 days post vector administration. At 14 days, the epithelium of treated mice contained clusters (4 to 8 adjacent cells) of well differentiated ciliated, as well as basal cells suggesting a clonal expansion. These results indicate that our lentiviral vector can transduce progenitor basal cells in vivo, although transduction required denudation of the surface epithelium prior to vector administration. PMID:26471068

  11. Using Drugs to Probe the Variability of Trans-Epithelial Airway Resistance

    PubMed Central

    Tosoni, Kendra; Cassidy, Diane; Kerr, Barry; Land, Stephen C.; Mehta, Anil

    2016-01-01

    Background Precision medicine aims to combat the variability of the therapeutic response to a given medicine by delivering the right medicine to the right patient. However, the application of precision medicine is predicated on a prior quantitation of the variance of the reference range of normality. Airway pathophysiology provides a good example due to a very variable first line of defence against airborne assault. Humans differ in their susceptibility to inhaled pollutants and pathogens in part due to the magnitude of trans-epithelial resistance that determines the degree of epithelial penetration to the submucosal space. This initial ‘set-point’ may drive a sentinel event in airway disease pathogenesis. Epithelia differentiated in vitro from airway biopsies are commonly used to model trans-epithelial resistance but the ‘reference range of normality’ remains problematic. We investigated the range of electrophysiological characteristics of human airway epithelia grown at air-liquid interface in vitro from healthy volunteers focusing on the inter- and intra-subject variability both at baseline and after sequential exposure to drugs modulating ion transport. Methodology/Principal Findings Brushed nasal airway epithelial cells were differentiated at air-liquid interface generating 137 pseudostratified ciliated epithelia from 18 donors. A positively-skewed baseline range exists for trans-epithelial resistance (Min/Max: 309/2963 Ω·cm2), trans-epithelial voltage (-62.3/-1.8 mV) and calculated equivalent current (-125.0/-3.2 μA/cm2; all non-normal, P<0.001). A minority of healthy humans manifest a dramatic amiloride sensitivity to voltage and trans-epithelial resistance that is further discriminated by prior modulation of cAMP-stimulated chloride transport. Conclusions/Significance Healthy epithelia show log-order differences in their ion transport characteristics, likely reflective of their initial set-points of basal trans-epithelial resistance and sodium

  12. Macrolides Inhibit Fusobacterium nucleatum-Induced MUC5AC Production in Human Airway Epithelial Cells

    PubMed Central

    Nagaoka, Kentaro; Harada, Yosuke; Yamada, Koichi; Migiyama, Yohei; Morinaga, Yoshitomo; Hasegawa, Hiroo; Izumikawa, Koichi; Kakeya, Hiroshi; Nishimura, Masaharu; Kohno, Shigeru

    2013-01-01

    Fusobacterium nucleatum is one of the most common anaerobic bacteria in periodontitis and is responsible for several extraoral infections, including respiratory tract diseases. In this study, we examined whether F. nucleatum induces mucin secretion in airway epithelial cells. We also examined the effects of macrolides on F. nucleatum-induced mucus production compared with the effects of other antibiotics that exert anti-anaerobic activities. The production of MUC5AC, the major core protein of mucin secreted from the airway surface epithelium, in bronchial epithelial cells after stimulation with culture supernatants (Sup) of F. nucleatum was analyzed by performing enzyme-linked immunosorbent assay and quantitative RT-PCR. The cell-signaling pathway of F. nucleatum Sup stimulation was also analyzed by Western blotting. For inhibition studies, cells were treated with azithromycin, clarithromycin, clindamycin (CLDM), and metronidazole (MTZ). The F. nucleatum Sup induced NCI-H292 cells to express MUC5AC at both the protein level and the mRNA level in both a time- and dose-dependent manner. Macrolides inhibited F. nucleatum Sup-induced MUC5AC production, while CLDM and MTZ were less effective. F. nucleatum Sup induced the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and this induction was suppressed by macrolides. F. nucleatum Sup-induced MUC5AC production was blocked by the ERK pathway inhibitor U0126. F. nucleatum is likely to contribute to excessive mucin production, which suggests that periodontitis may correlate with the pathogenesis of chronic respiratory tract infection. Macrolides seem to reduce this mucin production and might represent an additional means of therapeutic intervention for F. nucleatum respiratory tract infections other than CLDM and MTZ. PMID:23380724

  13. Sex differences in the development of airway epithelial tolerance to naphthalene

    PubMed Central

    Sutherland, K. M.; Edwards, P. C.; Combs, T. J.

    2012-01-01

    Exposure to air pollution has been linked to pulmonary diseases. Naphthalene (NA), an abundant polycyclic aromatic hydrocarbon in tobacco smoke and urban air, is a model toxicant for air pollution effects in the lung. Repeated exposures to NA in male mice result in tolerance, defined as the emergence of a resistant cell phenotype after prior exposure. Tolerance has not been studied in females. Females have sex differences in airway epithelial responses and in the prevalence of certain airway diseases. Male and female mice were exposed to a tolerance-inducing regimen of NA, and lungs were examined by airway level to characterize the cellular changes associated with repeated NA exposure and to assess the expression of genes and proteins involved in NA bioactivation and detoxification. The airway epithelium in treated males resembled that of controls. Females in the tolerant state were characterized by dense populations of ciliated cells in midlevel, distal, and bifurcating airways and a lower abundance of Clara cells at all airway levels. Cytotoxicity following a secondary challenge dose was also greater in females than males. Furthermore, females had decreased gene/protein expression of CYP2F2, a P-450 that metabolizes NA to a toxic epoxide, and glutamate-cysteine ligase, the rate-limiting enzyme in glutathione synthesis, than NA-tolerant males at all airway levels examined. We conclude that, while females develop tolerance, sex differences exist in the tolerant state by airway level, and females remain more susceptible than males to repeated exposures to NA. PMID:22003090

  14. Curcumin regulates airway epithelial cell cytokine responses to the pollutant cadmium

    SciTech Connect

    Rennolds, Jessica; Malireddy, Smitha; Hassan, Fatemat; Tridandapani, Susheela; Parinandi, Narasimham; Boyaka, Prosper N.; Cormet-Boyaka, Estelle

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Cadmium induces secretion of IL-6 and IL-8 by two distinct pathways. Black-Right-Pointing-Pointer Cadmium increases NAPDH oxidase activity leading to Erk activation and IL-8 secretion. Black-Right-Pointing-Pointer Curcumin prevents cadmium-induced secretion of both IL-6 and IL-8 by airway cells. Black-Right-Pointing-Pointer Curcumin could be use to suppress lung inflammation due to cadmium inhalation. -- Abstract: Cadmium is a toxic metal present in the environment and its inhalation can lead to pulmonary disease such as lung cancer and chronic obstructive pulmonary disease. These lung diseases are characterized by chronic inflammation. Here we show that exposure of human airway epithelial cells to cadmium promotes a polarized apical secretion of IL-6 and IL-8, two pivotal pro-inflammatory cytokines known to play an important role in pulmonary inflammation. We also determined that two distinct pathways controlled secretion of these proinflammatory cytokines by human airway epithelial cells as cadmium-induced IL-6 secretion occurs via an NF-{kappa}B dependent pathway, whereas IL-8 secretion involves the Erk1/2 signaling pathway. Interestingly, the natural antioxidant curcumin could prevent both cadmium-induced IL-6 and IL-8 secretion by human airway epithelial cells. In conclusion, curcumin could be used to prevent airway inflammation due to cadmium inhalation.

  15. Epithelial modulation of preterm airway smooth muscle contraction.

    PubMed

    Panitch, H B; Wolfson, M R; Shaffer, T H

    1993-03-01

    To determine if epithelium from immature airways can modulate the responsiveness of smooth muscle, we studied paired trachealis muscle strips from preterm sheep. The epithelium was removed from one strip and left undisturbed in the other. Concentration-effect (CE) curves to acetylcholine (ACh), KCl, and isoproterenol were obtained. To evaluate maturational effects, responses to ACh and isoproterenol were studied in trachealis strips from adult airways. Maximal stress (Po) to ACh increased after epithelium removal in preterm (P < 0.05) but not adult strips. Epithelium removal caused a leftward shift of the ACh CE curves in both preterm and adult strips (P < 0.001) and a decrease in the dose required to achieve a one-half maximal response (ED50) in both preterm (P < 0.005) and adult strips (P < 0.05). The magnitude of the change in Po as well as in the ED50 for ACh between preterms and adults was similar. Epithelium removal did not alter either the Po or the CE curves of preterm strips stimulated by KCl. Response to isoproterenol in precontracted strips was enhanced in the presence of an intact epithelium in both groups (P < 0.05). These data demonstrate that preterm airway epithelium is able to modulate the responsiveness of smooth muscle. Additionally, the magnitude of the effect is unchanged with maturation. We speculate that damage of airway epithelium from mechanical ventilation may contribute to the increased incidence of airway hyperreactivity observed in preterm infants. PMID:8482688

  16. TLR-2 IS INVOLVED IN AIRWAY EPITHELIAL CELL RESPONE TO AIR POLLUTION PARTICLES

    EPA Science Inventory

    Primary cultures of normal human airway epithelial cells (NHBE) respond to ambient air pollution particulate matter (PM) by increased production of the cytokine IL-8, and the induction of a number of oxidant stress response genes. Components of ambient air PM responsible for stim...

  17. CULTURE CONDITIONS AFFECT HUMAN AIRWAY EPITHELIAL CELL RESPONSE TO DIESEL PARTICLE EXPOSURE IN VITRO

    EPA Science Inventory

    Diesel exhaust particles (DEP) are a ubiquitous ambient air contaminant that may contribute to the health effects of particulate matter inhalation. In vitro studies have shown that DEP exposure induces pro-inflammatory proteins in human airway epithelial cells (HAEC) with varying...

  18. SIGNALING MECHANISMS IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO CARBON ULTRAFINE PARTICLES

    EPA Science Inventory

    SIGNALING MECHANISMS IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO CARBON ULTRAFINE PARTICLES
    Y.M. Kim, A.G. Lenz, R. Silbajoris, I. Jaspers and J.M. Samet. Department of Environmental Sciences and Engineering and Center for Environmental Medicine, University of North Carolina, ...

  19. Mathematical modeling of airway epithelial wound closure during cyclic mechanical strain.

    PubMed

    Savla, Ushma; Olson, Lars E; Waters, Christopher M

    2004-02-01

    The repair of airway epithelium after injury is crucial in restoring epithelial barrier integrity. Because the airways are stretched and compressed due to changes in both circumferential and longitudinal dimensions during respiration and may be overdistended during mechanical ventilation, we investigated the effect of cyclic strain on the repair of epithelial wounds. Both cyclic elongation and compression significantly slowed repair, with compression having the greatest effect. We developed a mathematical model of the mechanisms involved in airway epithelial cell wound closure. The model focuses on the differences in spreading, migration, and proliferation with cyclic strain by using separate parameters for each process and incorporating a time delay for the mitotic component. Numerical solutions of model equations determine the shape of the diffusive wave solutions of cell density that correspond to the influx of cells into the wound during the initial phase of reepithelialization. Model simulations were compared with experimental measurements of cell density and the rate of wound closure, and parameters were determined based on measurements from airway epithelial cells from several different sources. The contributions of spreading, migration, and mitosis were investigated both numerically and experimentally by using cytochalasin D to inhibit cell motility and mitomycin C to inhibit proliferation. PMID:14715680

  20. [Allergens-induced sensitization alters airway epithelial adhesion molecules expression in mice].

    PubMed

    Zeng, Dan; Tan, Mei-Ling; Xiang, Yang; Qin, Xiao-Qun; Zhu, Li-Ming; Dai, Ai-Guo

    2015-12-25

    To explore the relationship between the epithelial adhesion molecules and immune responses of airway epithelium, we observed the expression of integrin β4 and intercellular adhesion molecule-1 (ICAM-1) in the mice airway epithelium after sensitization with allergens. BALB/c mice were sensitized with intraperitoneal injection of ovalbumin (OVA) or house dust mite (HDM) and then developed airway hyper-responsiveness as determined by barometric whole-body plethysmography. Both OVA and HDM sensitization led to increases of the number of peripheral leukocytes as well as inflammatory cells infiltration in lungs. OVA sensitized mice showed more severe inflammatory cells infiltration than HDM sensitized mice. Immunohistochemistry analysis of mice lung tissues revealed that sensitization with both allergens also led to a decrease of integrin β4 expression and an increase of ICAM-1 expression in airway epithelia. OVA sensitized mice showed a more significant increase of ICAM-1 expression compared with HDM sensitized mice. siRNA mediated silencing of integrin β4 gene in 16HBE cells resulted in an up-regulation of ICAM-1 expression. Our results indicate a possible role of airway epithelial adhesion molecules in allergen-induced airway immune responses. PMID:26701635

  1. Store-operated Ca2+ channels in airway epithelial cell function and implications for asthma.

    PubMed

    Samanta, Krishna; Parekh, Anant B

    2016-08-01

    The epithelial cells of the lung are at the interface of a host and its environment and are therefore directly exposed to the inhaled air-borne particles. Rather than serving as a simple physical barrier, airway epithelia detect allergens and other irritants and then help organize the subsequent immune response through release of a plethora of secreted signals. Many of these signals are generated in response to opening of store-operated Ca(2+) channels in the plasma membrane. In this review, we describe the properties of airway store-operated channels and their role in regulating airway epithelial cell function.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. PMID:27377718

  2. Store-operated Ca2+ channels in airway epithelial cell function and implications for asthma

    PubMed Central

    Samanta, Krishna; Parekh, Anant B.

    2016-01-01

    The epithelial cells of the lung are at the interface of a host and its environment and are therefore directly exposed to the inhaled air-borne particles. Rather than serving as a simple physical barrier, airway epithelia detect allergens and other irritants and then help organize the subsequent immune response through release of a plethora of secreted signals. Many of these signals are generated in response to opening of store-operated Ca2+ channels in the plasma membrane. In this review, we describe the properties of airway store-operated channels and their role in regulating airway epithelial cell function. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’. PMID:27377718

  3. Airway Surface Mycosis in Chronic Th2-Associated Airway Disease

    PubMed Central

    Porter, Paul; Lim, Dae Jun; Maskatia, Zahida Khan; Mak, Garbo; Tsai, Chu-Lin; Citardi, Martin J; Fakhri, Samer; Shaw, Joanne L.; Fothergil, Annette; Kheradmand, Farrah; Corry, David B; Luong, Amber

    2014-01-01

    Background Environmental fungi have been linked to T helper type 2 (Th2) cell-related airway inflammation and the Th2-associated chronic airway diseases asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and allergic fungal rhinosinusitis (AFRS), but whether these organisms participate directly or indirectly in disease pathology remains unknown. Objective To determine the frequency of fungus isolation and fungus-specific immunity in Th2-associated and non-associated airway disease patients. Methods Sinus lavage fluid and blood were collected from sinus surgery patients (n=118) including CRS patients with and without nasal polyps and AFRS and non-CRS/non-asthmatic control patients. Asthma status was deteremined from medical history. Sinus lavage fluids were cultured and directly examined for evidence of viable fungi. Peripheral blood mononuclear cells were restimulated with fungal antigens in an enzyme linked immunocell spot (ELISpot) assay to determine total memory fungus-specific IL-4-secreting cells. These data were compared to fungus-specific IgE levels measured from plasma by ELISA. Results Filamentous fungi were significantly more commonly cultured from Th2-associated airway disease subjects (asthma, CRSwNP, or AFRS: n=68) compared to non-Th2-associated control patients (n=31); 74% vs 16% respectively, p<0.001. Both fungus-specific IL-4 ELISpot (n=48) and specific IgE (n=70) data correlated with Th2-associated diseases (sensitivity 73% and specificity 100% vs. 50% and 77%, respectively). Conclusions The frequent isolation of fungi growing directly within the airways accompanied by specific immunity to these organisms only in patients with Th2-associated chronic airway diseases suggests that fungi participate directly in the pathogenesis of these conditions. Efforts to eradicate airway fungi from the airways should be considered in selected patients. Clinical Implications Airway fungi may contribute to the expression of sinusitis with nasal polyps and

  4. Epithelial barrier function: at the frontline of asthma immunology and allergic airway inflammation

    PubMed Central

    Georas, Steve N.; Rezaee, Fariba

    2014-01-01

    Airway epithelial cells form a barrier to the outside world, and are at the frontline of mucosal immunity. Epithelial apical junctional complexes are multi-protein subunits that promote cell-cell adhesion and barrier integrity. Recent studies in the skin and GI tract suggest that disruption of cell-cell junctions is required to initiate epithelial immune responses, but how this applies to mucosal immunity in the lung is not clear. Increasing evidence indicates that defective epithelial barrier function is a feature of airway inflammation in asthma. One challenge in this area is that barrier function and junctional integrity are difficult to study in the intact lung, but innovative approaches should provide new knowledge in this area in the near future. In this article, we review the structure and function of epithelial apical junctional complexes, emphasizing how regulation of the epithelial barrier impacts innate and adaptive immunity. We discuss why defective epithelial barrier function may be linked to Th2 polarization in asthma, and propose a rheostat model of barrier dysfunction that implicates the size of inhaled allergen particles as an important factor influencing adaptive immunity. PMID:25085341

  5. Dendritic cell-derived tumor necrosis factor α modifies airway epithelial cell responses.

    PubMed

    Lutfi, R; Ledford, J R; Zhou, P; Lewkowich, I P; Page, K

    2012-01-01

    Mucosal dendritic cells (DC) are intimately associated with the airway epithelium and thus are ideally situated to be first responders to pathogens. We hypothesize that DC drive innate immune responses through early release of tumor necrosis factor (TNF) α, which drives airway epithelial cell responses. In a mouse model, TNFα release was significantly increased following a single exposure to German cockroach (GC) frass, an event independent of neutrophil recruitment into the airways. While lung epithelial cells and alveolar macrophages failed to release TNFα following GC frass exposure, bone marrow-derived DC (BMDC) produced substantial amounts of TNFα suggesting their importance as early responding cells. This was confirmed by flow cytometry of pulmonary myeloid DC. Addition of GC frass-pulsed BMDC or conditioned media from GC frass-pulsed BMDC to primary mouse tracheal epithelial cells (MTEC) or MLE-15 cells induced chemokine (C-C) motif ligand (CCL) 20 and granulocyte macrophage (GM) colony-stimulating factor (CSF), both of which are important for DC recruitment, survival and differentiation. Importantly, DC do not produce CCL20 or GM-CSF following allergen exposure. Blocking TNFα receptor 1 (TNFR1) completely abolished chemokine production, suggesting that BMDC-derived TNFα induced airway epithelial cell activation and enhancement of the innate immune response. Lastly, blocking TNFR1 in vivo resulted in significantly decreased CCL20 and GM-CSF production in the lungs of mice. Together, our data strongly suggest that DC-derived TNFα plays a crucial role in the initiation of innate immune responses through the modification of airway epithelial cell responses. PMID:22517116

  6. 1,25-Dihydroxyvitamin D3 prevents toluene diisocyanate-induced airway epithelial barrier disruption.

    PubMed

    Li, Wenjia; Dong, Hangming; Zhao, Haijin; Song, Jiafu; Tang, Haixiong; Yao, Lihong; Liu, Laiyu; Tong, Wancheng; Zou, Mengchen; Zou, Fei; Cai, Shaoxi

    2015-07-01

    The loss of airway epithelial integrity contributes significantly to asthma pathogenesis. Evidence suggests that vitamin D plays an important role in the prevention and treatment of asthma. However, its role in airway epithelial barrier function remains uncertain. We have previously demonstrated impaired epithelial junctions in a model of toluene diisocyanate (TDI)-induced asthma. In the present study, we hypothesized that 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] may prevent TDI-induced epithelial barrier disruption. Male BALB/c mice were dermally sensitized and then challenged with TDI. The mice were then administered 1,25(OH)2D3 intraperitoneally prior to challenge with TDI. For in vitro experiments, 16HBE bronchial epithelial cells were cultured and stimulated with TDI-human serum albumin (HSA). The results revealed that the mice treated with 1,25(OH)2D3 displayed decreased airway hyperresponsiveness (AHR), suppressed neutrophil and eosinophil infiltration into the airways, as well as an increased E-cadherin and zonula occludens-1 (ZO-1) expression at the cell-cell contact sites. In vitro, exposure of the cells to TDI-HSA induced a rapid decline in transepithelial electrical resistance (TER) and an increase in cell permeability, followed by a decrease in occludin expression and the redistribution of E-cadherin, accompanied by a significant upregulation in the levels of phosphorylated extracellular signal-regulated kinase (ERK)1/2. These effects were all partly reversed by treatment with either 1,25(OH)2D3 or an ERK1/2 inhibitor. In conclusion, the findings of our study demonstrate that 1,25(OH)2D3 prevents TDI-induced epithelial barrier disruption, and that the ERK1/2 pathway may play a role in this process. PMID:25998793

  7. miR-17 overexpression in cystic fibrosis airway epithelial cells decreases interleukin-8 production.

    PubMed

    Oglesby, Irene K; Vencken, Sebastian F; Agrawal, Raman; Gaughan, Kevin; Molloy, Kevin; Higgins, Gerard; McNally, Paul; McElvaney, Noel G; Mall, Marcus A; Greene, Catherine M

    2015-11-01

    Interleukin (IL)-8 levels are higher than normal in cystic fibrosis (CF) airways, causing neutrophil infiltration and non-resolving inflammation. Overexpression of microRNAs that target IL-8 expression in airway epithelial cells may represent a therapeutic strategy for cystic fibrosis. IL-8 protein and mRNA were measured in cystic fibrosis and non-cystic fibrosis bronchoalveolar lavage fluid and bronchial brushings (n=20 per group). miRNAs decreased in the cystic fibrosis lung and predicted to target IL-8 mRNA were quantified in βENaC-transgenic, cystic fibrosis transmembrane conductance regulator (Cftr)-/- and wild-type mice, primary cystic fibrosis and non-cystic fibrosis bronchial epithelial cells and a range of cystic fibrosis versus non-cystic fibrosis airway epithelial cell lines or cells stimulated with lipopolysaccharide, Pseudomonas-conditioned medium or cystic fibrosis bronchoalveolar lavage fluid. The effect of miRNA overexpression on IL-8 protein production was measured. miR-17 regulates IL-8 and its expression was decreased in adult cystic fibrosis bronchial brushings, βENaC-transgenic mice and bronchial epithelial cells chronically stimulated with Pseudomonas-conditioned medium. Overexpression of miR-17 inhibited basal and agonist-induced IL-8 protein production in F508del-CFTR homozygous CFTE29o(-) tracheal, CFBE41o(-) and/or IB3 bronchial epithelial cells. These results implicate defective CFTR, inflammation, neutrophilia and mucus overproduction in regulation of miR-17. Modulating miR-17 expression in cystic fibrosis bronchial epithelial cells may be a novel anti-inflammatory strategy for cystic fibrosis and other chronic inflammatory airway diseases. PMID:26160865

  8. Airway epithelial SPDEF integrates goblet cell differentiation and pulmonary Th2 inflammation.

    PubMed

    Rajavelu, Priya; Chen, Gang; Xu, Yan; Kitzmiller, Joseph A; Korfhagen, Thomas R; Whitsett, Jeffrey A

    2015-05-01

    Epithelial cells that line the conducting airways provide the initial barrier and innate immune responses to the abundant particles, microbes, and allergens that are inhaled throughout life. The transcription factors SPDEF and FOXA3 are both selectively expressed in epithelial cells lining the conducting airways, where they regulate goblet cell differentiation and mucus production. Moreover, these transcription factors are upregulated in chronic lung disorders, including asthma. Here, we show that expression of SPDEF or FOXA3 in airway epithelial cells in neonatal mice caused goblet cell differentiation, spontaneous eosinophilic inflammation, and airway hyperresponsiveness to methacholine. SPDEF expression promoted DC recruitment and activation in association with induction of Il33, Csf2, thymic stromal lymphopoietin (Tslp), and Ccl20 transcripts. Increased Il4, Il13, Ccl17, and Il25 expression was accompanied by recruitment of Th2 lymphocytes, group 2 innate lymphoid cells, and eosinophils to the lung. SPDEF was required for goblet cell differentiation and pulmonary Th2 inflammation in response to house dust mite (HDM) extract, as both were decreased in neonatal and adult Spdef(-/-) mice compared with control animals. Together, our results indicate that SPDEF causes goblet cell differentiation and Th2 inflammation during postnatal development and is required for goblet cell metaplasia and normal Th2 inflammatory responses to HDM aeroallergen. PMID:25866971

  9. The effect of N-acetylcysteine on chloride efflux from airway epithelial cells.

    PubMed

    Varelogianni, Georgia; Oliynyk, Igor; Roomans, Godfried M; Johannesson, Marie

    2010-03-01

    Defective chloride transport in epithelial cells increases mucus viscosity and leads to recurrent infections with high oxidative stress in patients with CF (cystic fibrosis). NAC (N-acetylcysteine) is a well known mucolytic and antioxidant drug, and an indirect precursor of glutathione. Since GSNO (S-nitrosoglutathione) previously has been shown to be able to promote Cl- efflux from CF airway epithelial cells, it was investigated whether NAC also could stimulate Cl- efflux from CF and non-CF epithelial cells and through which mechanisms. CFBE (CF bronchial epithelial cells) and normal bronchial epithelial cells (16HBE) were treated with 1 mM, 5 mM, 10 mM or 15 mM NAC for 4 h at 37 degrees C. The effect of NAC on Cl- transport was measured by Cl- efflux measurements and by X-ray microanalysis. Cl- efflux from CFBE cells was stimulated by NAC in a dose-dependent manner, with 10 mM NAC causing a significant increase in Cl- efflux with nearly 80% in CFBE cells. The intracellular Cl- concentration in CFBE cells was significantly decreased up to 60% after 4 h treatment with 10 mM NAC. Moreover immunocytochemistry and Western blot experiments revealed expression of CFTR channel on CFBE cells after treatment with 10 mM NAC. The stimulation of Cl- efflux by NAC in CF airway epithelial cells may improve hydration of the mucus and thereby be beneficial for CF patients. PMID:19947928

  10. Brief mechanical ventilation causes differential epithelial repair along the airways of fetal, preterm lambs.

    PubMed

    Deptula, Nicole; Royse, Emily; Kemp, Matthew W; Miura, Yuichiro; Kallapur, Suhas G; Jobe, Alan H; Hillman, Noah H

    2016-08-01

    Mechanical ventilation of preterm lambs causes lung inflammation and injury to the airway epithelium, which is repaired by 15 days after ventilation. In mice, activated basal cells (p63+, KRT14+, KRT8+) initiate injury repair to the trachea, whereas club cells coordinate distal airway repair. In both human and sheep, basal cells line the pseudostratified airways to the distal bronchioles with club cells only present in terminal bronchioles. Mechanical ventilation causes airway epithelial injury that is repaired through basal cell activation in the fetal lung. Ewes at 123 ± 1 day gestational age had the head and chest of the fetus exteriorized and tracheostomy placed. With placental circulation intact, fetal lambs were mechanically ventilated with up to 15 ml/kg for 15 min with 95% N2/5% CO2 Fetal lambs were returned to the uterus for up to 24 h. The trachea, left mainstem bronchi, and peripheral lung were evaluated for epithelial injury and cellular response consistent with repair. Peripheral lung tissue had inflammation, pro-inflammatory cytokine production, epithelial growth factor receptor ligand upregulation, increased p63 expression, and proliferation of pro-SPB, TTF-1 positive club cells. In bronchi, KRT14 and KRT8 mRNA increased without increases in Notch pathway mRNA or proliferation. In trachea, mRNA increased for Notch ligands, SAM pointed domain-containing Ets transcription factor and mucin 5B, but not for basal cell markers. A brief period of mechanical ventilation causes differential epithelial activation between trachea, bronchi, and peripheral lung. The repair mechanisms identified in adult mice occur at different levels of airway branching in fetal sheep with basal and club cell activation. PMID:27343193

  11. Klotho expression is reduced in COPD airway epithelial cells: effects on inflammation and oxidant injury

    PubMed Central

    Gao, Wei; Yuan, Cheng; Zhang, Jingying; Li, Lingling; Yu, Like; Wiegman, Coen H.; Barnes, Peter J.; Adcock, Ian M.; Huang, Mao

    2015-01-01

    COPD (chronic obstructive pulmonary disease) is associated with sustained inflammation, excessive injury, and accelerated lung aging. Human Klotho (KL) is an anti-aging protein that protects cells against inflammation and damage. In the present study, we quantified KL expression in the lungs of COPD patients and in an ozone-induced mouse model of COPD, and investigated the mechanisms that control KL expression and function in the airways. KL distribution and levels in human and mouse airways were measured by immunohistochemistry and Western blotting. The effect of CSE (cigarette smoke extract) on KL expression was detected in human bronchial epithelial cells. Moreover, the effect of KL on CSE-mediated inflammation and hydrogen peroxide-induced cellular injury/apoptosis was determined using siRNAs. KL expression was decreased in the lungs of smokers and further reduced in patients with COPD. Similarly, 6 weeks of exposure to ozone decreased KL levels in airway epithelial cells. CSE and TNFα (tumour necrosis factor α) decreased KL expression and release from airway epithelial cells, which was associated with enhanced pro-inflammatory cytokine expression. Moreover, KL depletion increased cell sensitivity to cigarette smoke-induced inflammation and oxidative stress-induced cell damage. These effects involved the NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and Nrf2 (nuclear factor erythroid 2-related factor 2) pathways. Reduced KL expression in COPD airway epithelial cells was associated with increased oxidative stress, inflammation and apoptosis. These data provide new insights into the mechanisms associated with the accelerated lung aging in COPD development. PMID:26201096

  12. Klotho expression is reduced in COPD airway epithelial cells: effects on inflammation and oxidant injury.

    PubMed

    Gao, Wei; Yuan, Cheng; Zhang, Jingying; Li, Lingling; Yu, Like; Wiegman, Coen H; Barnes, Peter J; Adcock, Ian M; Huang, Mao; Yao, Xin

    2015-12-01

    COPD (chronic obstructive pulmonary disease) is associated with sustained inflammation, excessive injury, and accelerated lung aging. Human Klotho (KL) is an anti-aging protein that protects cells against inflammation and damage. In the present study, we quantified KL expression in the lungs of COPD patients and in an ozone-induced mouse model of COPD, and investigated the mechanisms that control KL expression and function in the airways. KL distribution and levels in human and mouse airways were measured by immunohistochemistry and Western blotting. The effect of CSE (cigarette smoke extract) on KL expression was detected in human bronchial epithelial cells. Moreover, the effect of KL on CSE-mediated inflammation and hydrogen peroxide-induced cellular injury/apoptosis was determined using siRNAs. KL expression was decreased in the lungs of smokers and further reduced in patients with COPD. Similarly, 6 weeks of exposure to ozone decreased KL levels in airway epithelial cells. CSE and TNFα (tumour necrosis factor α) decreased KL expression and release from airway epithelial cells, which was associated with enhanced pro-inflammatory cytokine expression. Moreover, KL depletion increased cell sensitivity to cigarette smoke-induced inflammation and oxidative stress-induced cell damage. These effects involved the NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase) and Nrf2 (nuclear factor erythroid 2-related factor 2) pathways. Reduced KL expression in COPD airway epithelial cells was associated with increased oxidative stress, inflammation and apoptosis. These data provide new insights into the mechanisms associated with the accelerated lung aging in COPD development. PMID:26201096

  13. Pim1 kinase activity preserves airway epithelial integrity upon house dust mite exposure.

    PubMed

    de Vries, M; Hesse, L; Jonker, M R; van den Berge, M; van Oosterhout, A J M; Heijink, I H; Nawijn, M C

    2015-12-01

    Most patients with allergic asthma are sensitized to house dust mite (HDM). The allergenicity of HDM largely depends on disruption of the integrity and proinflammatory activation of the airway epithelium. In this study, we hypothesized that Pim1 kinase activity attenuates HDM-induced asthma by preserving airway epithelial integrity. The effects of Pim1 kinase activity on barrier function and release of the proinflammatory mediators IL-1α and CCL20 were studied in vitro in 16HBE and primary bronchial epithelial cells (PBECs). Pim1-proficient and -deficient mice were exposed to a HDM-driven model of allergic asthma, and airway hyperresponsiveness (AHR) was measured upon methacholine challenge. Airway inflammation and proinflammatory mediators in lung tissue and BAL fluid were determined. We observed that inhibition of Pim1 kinase prolongs the HDM-induced loss of barrier function in 16HBE cells and sensitizes PBECs to HDM-induced barrier dysfunction. Additionally, inhibition of Pim1 kinase increased the HDM-induced proinflammatory activity of 16HBE cells as measured by IL-1α secretion. In line herewith, HDM exposure induced an enhanced production of the proinflammatory chemokines CCL17 and CCL20 in Pim1-deficient mice compared with wild-type controls. While we observed a marked increase in eosinophilic and neutrophilic granulocytes as well as mucus cell metaplasia and AHR to methacholine in mice exposed to HDM, these parameters were independent of Pim1 kinase activity. In contrast, levels of the Th2-cytokines IL-5 and IL-10 were significantly augmented in HDM-treated Pim1-deficient mice. Taken together, our study shows that Pim1 kinase activity maintains airway epithelial integrity and protects against HDM-induced proinflammatory activation of the airway epithelium. PMID:26453516

  14. Arsenic Compromises Conducting Airway Epithelial Barrier Properties in Primary Mouse and Immortalized Human Cell Cultures

    PubMed Central

    Sherwood, Cara L.; Liguori, Andrew E.; Olsen, Colin E.; Lantz, R. Clark; Burgess, Jefferey L.; Boitano, Scott

    2013-01-01

    Arsenic is a lung toxicant that can lead to respiratory illness through inhalation and ingestion, although the most common exposure is through contaminated drinking water. Lung effects reported from arsenic exposure include lung cancer and obstructive lung disease, as well as reductions in lung function and immune response. As part of their role in innate immune function, airway epithelial cells provide a barrier that protects underlying tissue from inhaled particulates, pathogens, and toxicants frequently found in inspired air. We evaluated the effects of a five-day exposure to environmentally relevant levels of arsenic {<4μM [~300 μg/L (ppb)] as NaAsO2} on airway epithelial barrier function and structure. In a primary mouse tracheal epithelial (MTE) cell model we found that both micromolar (3.9 μM) and submicromolar (0.8 μM) arsenic concentrations reduced transepithelial resistance, a measure of barrier function. Immunofluorescent staining of arsenic-treated MTE cells showed altered patterns of localization of the transmembrane tight junction proteins claudin (Cl) Cl-1, Cl-4, Cl-7 and occludin at cell-cell contacts when compared with untreated controls. To better quantify arsenic-induced changes in tight junction transmembrane proteins we conducted arsenic exposure experiments with an immortalized human bronchial epithelial cell line (16HBE14o-). We found that arsenic exposure significantly increased the protein expression of Cl-4 and occludin as well as the mRNA levels of Cl-4 and Cl-7 in these cells. Additionally, arsenic exposure resulted in altered phosphorylation of occludin. In summary, exposure to environmentally relevant levels of arsenic can alter both the function and structure of airway epithelial barrier constituents. These changes likely contribute to the observed arsenic-induced loss in basic innate immune defense and increased infection in the airway. PMID:24349408

  15. Elastic properties of the bronchial mucosa: epithelial unfolding and stretch in response to airway inflation.

    PubMed

    Noble, P B; Sharma, A; McFawn, P K; Mitchell, H W

    2005-12-01

    The bronchial mucosa contributes to elastic properties of the airway wall and may influence the degree of airway expansion during lung inflation. In the deflated lung, folds in the epithelium and associated basement membrane progressively unfold on inflation. Whether the epithelium and basement membrane also distend on lung inflation at physiological pressures is uncertain. We assessed mucosal distensibility from strain-stress curves in mucosal strips and related this to epithelial length and folding. Mucosal strips were prepared from pig bronchi and cycled stepwise from a strain of 0 (their in situ length at 0 transmural pressure) to a strain of 0.5 (50% increase in length). Mucosal stress and epithelial length in situ were calculated from morphometric data in bronchial segments fixed at 5 and 25 cmH(2)O luminal pressure. Mucosal strips showed nonlinear strain-stress properties, but regions at high and low stress were close to linear. Stresses calculated in bronchial segments at 5 and 25 cmH(2)O fell in the low-stress region of the strain-stress curve. The epithelium of mucosal strips was deeply folded at low strains (0-0.15), which in bronchial segments equated to < or =10 cmH(2)O transmural pressure. Morphometric measurements in mucosal strips at greater strains (0.3-0.4) indicated that epithelial length increased by approximately 10%. Measurements in bronchial segments indicated that epithelial length increased approximately 25% between 5 and 25 cmH(2)O. Our findings suggest that, at airway pressures <10 cmH(2)O, airway expansion is due primarily to epithelial unfolding but at higher pressures the epithelium also distends. PMID:16024520

  16. Ciliary beating recovery in deficient human airway epithelial cells after lentivirus ex vivo gene therapy.

    PubMed

    Chhin, Brigitte; Negre, Didier; Merrot, Olivier; Pham, Jacqueline; Tourneur, Yves; Ressnikoff, Denis; Jaspers, Martine; Jorissen, Mark; Cosset, François-Loïc; Bouvagnet, Patrice

    2009-03-01

    Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1) gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1-deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT-PCR and western blot, respectively. Human airway epithelial cells that were DNAI1-deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease. PMID:19300481

  17. Ciliary Beating Recovery in Deficient Human Airway Epithelial Cells after Lentivirus Ex Vivo Gene Therapy

    PubMed Central

    Chhin, Brigitte; Negre, Didier; Merrot, Olivier; Pham, Jacqueline; Tourneur, Yves; Ressnikoff, Denis; Jaspers, Martine; Jorissen, Mark; Cosset, François-Loïc; Bouvagnet, Patrice

    2009-01-01

    Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1) gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1–deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT–PCR and western blot, respectively. Human airway epithelial cells that were DNAI1–deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease. PMID:19300481

  18. Stretch increases inositol 1,4,5-trisphosphate concentration in airway epithelial cells.

    PubMed

    Felix, J A; Woodruff, M L; Dirksen, E R

    1996-03-01

    Mechanical stimulation of airway epithelial cells with a microprobe leads to an increase in cytoplasmic [Ca2+] that appears to be due, in part, to release of Ca2+ from inositol 1,4,5-trisphosphate (IP3)-sensitive stores (Boitano et al., Science 258:292[1992]). To investigate whether intracellular IP3 concentration ([IP3]i) increases in response to mechanical stimulation, we grew confluent monolayers from rabbit tracheal mucosal explants on flexible substrates and measured [IP3]i after stretching the substrate. The effect of stretch on [IP3]i was measured in the presence of Li+, an inhibitor of IP3 degradation. In unstretched cells, IP3 measured approximately 5.1 pmol/10(6) cells, from which we estimated [IP3]i to be 1.8 microM. Addition of Li+ had no effect on resting [IP3]i. When the flexible cell support was stretched to increase its surface area by 13%, mean [IP3]i increased about 3-fold with a half-time of approximately 1 s. The increased [IP3]i was maintained in a plateau phase for approximately 8 s and then decayed to near the unstretched level over the next 10 s, despite the sustained application of stretch. A transient stretch (0.5 s) induced a similar rate of increase and peak [IP3]i; however, [IP3]i subsided without a plateau phase. The magnitude of the [IP3]i increase was proportional to stimulus intensity between 0 and 13% increase in substrate surface area. In addition, dissociated airway epithelial cells were exposed to hypotonic solution to induce cell swelling. [IP3]i increased about 4-fold above control levels after 10 s of exposure to hypotonic solution. Basal [IP3]i of dissociated cells in isotonic solution was estimated to be 0.7 microM. These results are consistent with mechanical stimulation leading to phospholipase C synthesis of IP3, which mediates intracellular and intercellular Ca2+ signaling. PMID:8845181

  19. Interactions between airway epithelial cells and dendritic cells during viral infections using an in vitro co-culture model

    EPA Science Inventory

    Rationale: Historically, single cell culture models have been limited in pathological and physiological relevance. A co-culture model of dendritic cells (DCs) and differentiated human airway epithelial cells was developed to examine potential interactions between these two cell t...

  20. IDENTIFICATION AND CHARACTERIZATION OF HUMAN AIRWAY EPITHELIAL CELL PROTEINS PHOSPHORYLATED IN RESPONSE TO PARTICULATE MATTER (PM) EXPOSURE.

    EPA Science Inventory

    Multiple studies conducted by NHEERL scientists in recent years have shown that acute exposure to metals found associated with combustion-derived particulate matter (PM) alters phosphoprotein metabolism in human airway epithelial cells causing intracellular signaling. This disreg...

  1. ACTIVATION OF THE EGF RECEPTOR SIGNALING PATHWAY IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO UTAH VALLEY PARTICULATE MATTER

    EPA Science Inventory

    Exposure to ambient particulate matter (PM) in the Utah Valley (UV) has previously been associated with a variety of adverse health effects. To investigate intracellular signaling mechanisms for pulmonary responses to UV PM inhalation, human primary airway epithelial cells (NHBE)...

  2. Roflumilast combined with adenosine increases mucosal hydration in human airway epithelial cultures after cigarette smoke exposure

    PubMed Central

    Tyrrell, Jean; Qian, Xiaozhong; Freire, Jose

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide. Recent studies have shown that cigarette smoke (CS) induces cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, which leads to airway-surface liquid (ASL) dehydration. This in turn contributes to the mucus dehydration and impaired mucociliary clearance that are seen in the chronic bronchitis form of COPD. Roflumilast is a phosphodiesterase 4 inhibitor that may improve lung function and reduce the frequency of exacerbations in patients with COPD. Although roflumilast can affect cAMP metabolism, little is known about the downstream pharmacological effects in the airways. We hypothesized that roflumilast would increase ASL rehydration in human bronchial epithelial cultures (HBECs) after chronic CS exposure. cAMP production was measured by Förster resonance energy transfer in HEK293T cells and by ELISA in HBECs. ASL height was measured by xz-confocal microscopy after air exposure or following HBEC exposure to freshly produced CS. Roflumilast had little effect on cAMP or ASL height when applied on its own; however, roflumilast significantly potentiated adenosine-induced increases in cAMP and ASL height in CS-exposed HBECs. Roflumilast increased the rate of ASL height recovery in cultures after CS exposure compared with controls. In contrast, the β2-adrenergic receptor agonists isoproterenol and salmeterol failed to increase ASL height after CS exposure. Our data suggest that roflumilast can increase ASL hydration in CS-exposed HBECs, which is predicted to be beneficial for the treatment of mucus dehydration/mucus stasis in patients with COPD chronic bronchitis. PMID:25795727

  3. Roflumilast combined with adenosine increases mucosal hydration in human airway epithelial cultures after cigarette smoke exposure.

    PubMed

    Tyrrell, Jean; Qian, Xiaozhong; Freire, Jose; Tarran, Robert

    2015-05-15

    Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide. Recent studies have shown that cigarette smoke (CS) induces cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, which leads to airway-surface liquid (ASL) dehydration. This in turn contributes to the mucus dehydration and impaired mucociliary clearance that are seen in the chronic bronchitis form of COPD. Roflumilast is a phosphodiesterase 4 inhibitor that may improve lung function and reduce the frequency of exacerbations in patients with COPD. Although roflumilast can affect cAMP metabolism, little is known about the downstream pharmacological effects in the airways. We hypothesized that roflumilast would increase ASL rehydration in human bronchial epithelial cultures (HBECs) after chronic CS exposure. cAMP production was measured by Förster resonance energy transfer in HEK293T cells and by ELISA in HBECs. ASL height was measured by xz-confocal microscopy after air exposure or following HBEC exposure to freshly produced CS. Roflumilast had little effect on cAMP or ASL height when applied on its own; however, roflumilast significantly potentiated adenosine-induced increases in cAMP and ASL height in CS-exposed HBECs. Roflumilast increased the rate of ASL height recovery in cultures after CS exposure compared with controls. In contrast, the β2-adrenergic receptor agonists isoproterenol and salmeterol failed to increase ASL height after CS exposure. Our data suggest that roflumilast can increase ASL hydration in CS-exposed HBECs, which is predicted to be beneficial for the treatment of mucus dehydration/mucus stasis in patients with COPD chronic bronchitis. PMID:25795727

  4. Inhibition of airway epithelial-to-mesenchymal transition and fibrosis by kaempferol in endotoxin-induced epithelial cells and ovalbumin-sensitized mice.

    PubMed

    Gong, Ju-Hyun; Cho, In-Hee; Shin, Daekeun; Han, Seon-Young; Park, Sin-Hye; Kang, Young-Hee

    2014-03-01

    Chronic airway remodeling is characterized by structural changes within the airway wall, including smooth muscle hypertrophy, submucosal fibrosis and epithelial shedding. Epithelial-to-mesenchymal transition (EMT) is a fundamental mechanism of organ fibrosis, which can be induced by TGF-β. In the in vitro study, we investigated whether 1-20 μM kaempferol inhibited lipopolysaccharide (LPS)-induced bronchial EMT in BEAS-2B cells. The in vivo study explored demoting effects of 10-20 mg/kg kaempferol on airway fibrosis in BALB/c mice sensitized with ovalbumin (OVA). LPS induced airway epithelial TGF-β1 signaling that promoted EMT with concurrent loss of E-cadherin and induction of α-smooth muscle actin (α-SMA). Nontoxic kaempferol significantly inhibited TGF-β-induced EMT process through reversing E-cadherin expression and retarding the induction of N-cadherin and α-SMA. Consistently, OVA inhalation resulted in a striking loss of epithelial morphology by displaying myofibroblast appearance, which led to bronchial fibrosis with submucosal accumulation of collagen fibers. Oral administration of kaempferol suppressed collagen deposition, epithelial excrescency and goblet hyperplasia observed in the lung of OVA-challenged mice. The specific inhibition of TGF-β entailed epithelial protease-activated receptor-1 (PAR-1) as with 20 μM kaempferol. The epithelial PAR-1 inhibition by SCH-79797 restored E-cadherin induction and deterred α-SMA induction, indicating that epithelial PAR-1 localization was responsible for resulting in airway EMT. These results demonstrate that dietary kaempferol alleviated fibrotic airway remodeling via bronchial EMT by modulating PAR1 activation. Therefore, kaempferol may be a potential therapeutic agent targeting asthmatic airway constriction. PMID:24378645

  5. Parabronchial smooth muscle constitutes an airway epithelial stem cell niche in the mouse lung after injury.

    PubMed

    Volckaert, Thomas; Dill, Erik; Campbell, Alice; Tiozzo, Caterina; Majka, Susan; Bellusci, Saverio; De Langhe, Stijn P

    2011-11-01

    During lung development, parabronchial SMC (PSMC) progenitors in the distal mesenchyme secrete fibroblast growth factor 10 (Fgf10), which acts on distal epithelial progenitors to promote their proliferation. β-catenin signaling within PSMC progenitors is essential for their maintenance, proliferation, and expression of Fgf10. Here, we report that this Wnt/Fgf10 embryonic signaling cascade is reactivated in mature PSMCs after naphthalene-induced injury to airway epithelium. Furthermore, we found that this paracrine Fgf10 action was essential for activating surviving variant Clara cells (the cells in the airway epithelium from which replacement epithelial cells originate) located at the bronchoalveolar duct junctions and adjacent to neuroendocrine bodies. After naphthalene injury, PSMCs secreted Fgf10 to activate Notch signaling and induce Snai1 expression in surviving variant Clara cells, which subsequently underwent a transient epithelial to mesenchymal transition to initiate the repair process. Epithelial Snai1 expression was important for regeneration after injury. We have therefore identified PSMCs as a stem cell niche for the variant Clara cells in the lung and established that paracrine Fgf10 signaling from the niche is critical for epithelial repair after naphthalene injury. These findings also have implications for understanding the misregulation of lung repair in asthma and cancer. PMID:21985786

  6. Altered Regulation of Airway Epithelial Cell Chloride Channels in Cystic Fibrosis

    NASA Astrophysics Data System (ADS)

    Frizzell, Raymond A.; Rechkemmer, Gerhard; Shoemaker, Richard L.

    1986-08-01

    In many epithelial cells the chloride conductance of the apical membrane increases during the stimulation of electrolyte secretion. Single-channel recordings from human airway epithelial cells showed that β -adrenergic stimulation evoked apical membrane chloride channel activity, but this response was absent in cells from patients with cystic fibrosis (CF). However, when membrane patches were excised from CF cells into media containing sufficient free calcium (approximately 180 nanomolar), chloride channels were activated. The chloride channels of CF cells were similar to those of normal cells as judged by their current-voltage relations, ion selectivity, and kinetic behavior. These findings demonstrate the presence of chloride channels in the apical membranes of CF airway cells. Their regulation by calcium appears to be intact, but cyclic adenosine monophosphate (cAMP)-dependent control of their activity is defective.

  7. Responses of well-differentiated nasal epithelial cells exposed to particles: Role of the epithelium in airway inflammation

    SciTech Connect

    Auger, Floriane; Gendron, Marie-Claude; Chamot, Christophe; Marano, Francelyne; Dazy, Anne-Catherine . E-mail: dazy@paris7.jussieu.fr

    2006-09-15

    Numerous epidemiological studies support the contention that ambient air pollution particles can adversely affect human health. To explain the acute inflammatory process in airways exposed to particles, a number of in vitro studies have been performed on cells grown submerged on plastic and poorly differentiated, and on cell lines, the physiology of which is somewhat different from that of well-differentiated cells. In order to obtain results using a model system in which epithelial cells are similar to those of the human airway in vivo, apical membranes of well-differentiated human nasal epithelial (HNE) cells cultured in an air-liquid interface (ALI) were exposed for 24 h to diesel exhaust particles (DEP) and Paris urban air particles (PM{sub 2.5}). DEP and PM{sub 2.5} (10-80 {mu}g/cm{sup 2}) stimulated both IL-8 and amphiregulin (ligand of EGFR) secretion exclusively towards the basal compartment. In contrast, there was no IL-1{beta} secretion and only weak non-reproducible secretion of TNF-{alpha}. IL-6 and GM-CSF were consistently stimulated towards the apical compartment and only when cells were exposed to PM{sub 2.5}. ICAM-1 protein expression on cell surfaces remained low after particle exposure, although it increased after TNF-{alpha} treatment. Internalization of particles, which is believed to initiate oxidative stress and proinflammatory cytokine expression, was restricted to small nanoparticles ({<=} 40 nm). Production of reactive oxygen species (ROS) was detected, and DEP were more efficient than PM{sub 2.5}. Collectively, our results suggest that airway epithelial cells exposed to particles augment the local inflammatory response in the lung but cannot alone initiate a systemic inflammatory response.

  8. Continuous mucociliary transport by primary human airway epithelial cells in vitro

    PubMed Central

    Sears, Patrick R.; Yin, Wei-Ning

    2015-01-01

    Mucociliary clearance (MCC) is an important innate defense mechanism that continuously removes inhaled pathogens and particulates from the airways. Normal MCC is essential for maintaining a healthy respiratory system, and impaired MCC is a feature of many airway diseases, including both genetic (cystic fibrosis, primary ciliary dyskinesia) and acquired (chronic obstructive pulmonary disease, bronchiectasis) disorders. Research into the fundamental processes controlling MCC, therefore, has direct clinical application, but has been limited in part due to the difficulty of studying this complex multicomponent system in vitro. In this study, we have characterized a novel method that allows human airway epithelial cells to differentiate into a mucociliary epithelium that transports mucus in a continuous circular track. The mucociliary transport device allows the measurement and manipulation of all features of mucociliary transport in a controlled in vitro system. In this initial study, the effect of ciliary beat frequency and mucus concentration on the speed of mucociliary transport was investigated. PMID:25979076

  9. Understanding Cellular Mechanisms Underlying Airway Epithelial Repair: Selecting the Most Appropriate Animal Models

    PubMed Central

    Yahaya, B.

    2012-01-01

    Understanding the mechanisms underlying the process of regeneration and repair of airway epithelial structures demands close characterization of the associated cellular and molecular events. The choice of an animal model system to study these processes and the role of lung stem cells is debatable since ideally the chosen animal model should offer a valid comparison with the human lung. Species differences may include the complex three-dimensional lung structures, cellular composition of the lung airway as well as transcriptional control of the molecular events in response to airway epithelium regeneration, and repair following injury. In this paper, we discuss issues related to the study of the lung repair and regeneration including the role of putative stem cells in small- and large-animal models. At the end of this paper, the author discuss the potential for using sheep as a model which can help bridge the gap between small-animal model systems and humans. PMID:23049478

  10. Human Airway Epithelial Cell Responses to Single Walled Carbon Nanotube Exposure: Nanorope-Residual Body Formation

    SciTech Connect

    Panessa-Warren, Barbara J.; Warren, John B.; Kisslinger, Kim; Crosson, Kenya; Maye, Mathew M.

    2012-11-01

    This investigation examines the 'first contact responses' of in vitro human epithelial airway cells exposed to unrefined single walled carbon nanotubes (SWCNTs) [containing metal catalyst, carbon black, amorphous carbon, graphitic shells, and SWCNTs], and refined acid/peroxide cleaned and cut SWCNTs at low and high dose exposures (0.16 ug/L and 1.60 ug/L) for 2, 3 and 3.5 hours. FTIR, X-ray compositional analysis, morphological TEM analysis and UV-Vis were used to physicochemically characterize the SWCNTs in this study. Following SWCNT exposure to human lung NCI-H292 epithelial monolayers, the airway cells were prepared for light microscopy vital staining, or fixed in glutaraldehyde for SEM/TEM imaging to determine SWCNT binding, uptake, intracellular processing and organellar/SWCNT fate within the exposure period. At 2 hr exposures to both unrefined Carbolex, and refined SWCNTs (at both high and low doses), there were no increases in lung cell necrosis compared to controls. However high dose, 3 hr exposures to unrefined Carbolex material produced severe cell damage (apical and basal plasma membrane holes, decreased mitochondria, numerous intracellular vesicles containing nanomaterial and membrane fragments) and increased cell necrosis. The refined SWCNTs exposed for 3 hr at low dose produced no increase in cell death, although high dose exposure produced significant cell death. By TEM, Acid/peroxide cleaned SWCNT 3 hr exposures at high and low doses, revealed SWCNTs attachment to cell surface mucin, and SWCNT uptake into the cells during membrane recycling. Membranes and SWCNTs were seen within cytoplasmic lamellar body-type vesicles, where vesicular contents were bio-degraded, eventually forming long SWCNT-nanoropes, which were subsequently released into the cytoplasm as clusters of attached nanoropes, as the vesicle membranes fragmented. These Nanorope-Residual Bodies did not cause damage to the surrounding organelles or cytoplasm, and seemed very stabile in the

  11. SERCA2 Regulates Non-CF and CF Airway Epithelial Cell Response to Ozone

    PubMed Central

    Ahmad, Shama; Nichols, David P.; Strand, Matthew; Rancourt, Raymond C.; Randell, Scott H.; White, Carl W.; Ahmad, Aftab

    2011-01-01

    Calcium mobilization can regulate a wide range of essential functions of respiratory epithelium, including ion transport, ciliary beat frequency, and secretion of mucus, all of which are modified in cystic fibrosis (CF). SERCA2, an important controller of calcium signaling, is deficient in CF epithelium. We conducted this study to determine whether SERCA2 deficiency can modulate airway epithelial responses to environmental oxidants such as ozone. This could contribute to the pathogenesis of pulmonary exacerbations, which are important and frequent clinical events in CF. To address this, we used air-liquid interface (ALI) cultures of non-CF and CF cell lines, as well as differentiated cultures of cells derived from non-CF and CF patients. We found that ozone exposure caused enhanced membrane damage, mitochondrial dysfunction and apoptotic cell death in CF airway epithelial cell lines relative to non-CF. Ozone exposure caused increased proinflammatory cytokine production in CF airway epithelial cell lines. Elevated proinflammatory cytokine production also was observed in shRNA-mediated SERCA2 knockdown cells. Overexpression of SERCA2 reversed ozone-induced proinflammatory cytokine production. Ozone-induced proinflammatory cytokine production was NF-κB- dependent. In a stable NF-κB reporter cell line, SERCA2 inhibition and knockdown both upregulated cytomix-induced NF-κB activity, indicating importance of SERCA2 in modulating NF-κB activity. In this system, increased NF-κB activity was also accompanied by increased IL-8 production. Ozone also induced NF-κB activity and IL-8 release, an effect that was greater in SERCA2-silenced NF-κB-reporter cells. SERCA2 overexpression reversed cytomix-induced increased IL-8 release and total nuclear p65 in CFTR-deficient (16HBE-AS) cells. These studies suggest that SERCA2 is an important regulator of the proinflammatory response of airway epithelial cells and could be a potential therapeutic target. PMID:22096575

  12. Chitin-Induced Airway Epithelial Cell Innate Immune Responses Are Inhibited by Carvacrol/Thymol.

    PubMed

    Khosravi, Ali Reza; Erle, David J

    2016-01-01

    Chitin is produced in large amounts by fungi, insects, and other organisms and has been implicated in the pathogenesis of asthma. Airway epithelial cells are in direct contact with environmental particles and serve as the first line of defense against inhaled allergens and pathogens. The potential contributions of airway epithelial cells to chitin-induced asthma remain poorly understood. We hypothesized that chitin directly stimulates airway epithelial cells to release cytokines that promote type 2 immune responses and to induce expression of molecules which are important in innate immune responses. We found that chitin exposure rapidly induced the expression of three key type 2-promoting cytokines, IL-25, IL-33 and TSLP, in BEAS-2B transformed human bronchial epithelial cells and in A549 and H292 lung carcinoma cells. Chitin also induced the expression of the key pattern recognition receptors TLR2 and TLR4. Chitin induced the expression of miR-155, miR-146a and miR-21, each of which is known to up-regulate the expression of pro-inflammatory cytokines. Also the expression of SOCS1 and SHIP1 which are known targets of miR-155 was repressed by chitin treatment. The monoterpene phenol carvacrol (Car) and its isomer thymol (Thy) are found in herbal essential oils and have been shown to inhibit allergic inflammation in asthma models. We found that Car/Thy inhibited the effects of chitin on type 2-promoting cytokine release and on the expression of TLRs, SOCS1, SHIP1, and miRNAs. Car/Thy could also efficiently reduce the protein levels of TLR4, inhibit the increase in TLR2 protein levels in chitin plus Car/Thy-treated cells and increase the protein levels of SHIP1 and SOCS1, which are negative regulators of TLR-mediated inflammatory responses. We conclude that direct effects of chitin on airway epithelial cells are likely to contribute to allergic airway diseases like asthma, and that Car/Thy directly inhibits epithelial cell pro-inflammatory responses to chitin. PMID

  13. Chitin-Induced Airway Epithelial Cell Innate Immune Responses Are Inhibited by Carvacrol/Thymol

    PubMed Central

    Erle, David J.

    2016-01-01

    Chitin is produced in large amounts by fungi, insects, and other organisms and has been implicated in the pathogenesis of asthma. Airway epithelial cells are in direct contact with environmental particles and serve as the first line of defense against inhaled allergens and pathogens. The potential contributions of airway epithelial cells to chitin-induced asthma remain poorly understood. We hypothesized that chitin directly stimulates airway epithelial cells to release cytokines that promote type 2 immune responses and to induce expression of molecules which are important in innate immune responses. We found that chitin exposure rapidly induced the expression of three key type 2-promoting cytokines, IL-25, IL-33 and TSLP, in BEAS-2B transformed human bronchial epithelial cells and in A549 and H292 lung carcinoma cells. Chitin also induced the expression of the key pattern recognition receptors TLR2 and TLR4. Chitin induced the expression of miR-155, miR-146a and miR-21, each of which is known to up-regulate the expression of pro-inflammatory cytokines. Also the expression of SOCS1 and SHIP1 which are known targets of miR-155 was repressed by chitin treatment. The monoterpene phenol carvacrol (Car) and its isomer thymol (Thy) are found in herbal essential oils and have been shown to inhibit allergic inflammation in asthma models. We found that Car/Thy inhibited the effects of chitin on type 2-promoting cytokine release and on the expression of TLRs, SOCS1, SHIP1, and miRNAs. Car/Thy could also efficiently reduce the protein levels of TLR4, inhibit the increase in TLR2 protein levels in chitin plus Car/Thy-treated cells and increase the protein levels of SHIP1 and SOCS1, which are negative regulators of TLR-mediated inflammatory responses. We conclude that direct effects of chitin on airway epithelial cells are likely to contribute to allergic airway diseases like asthma, and that Car/Thy directly inhibits epithelial cell pro-inflammatory responses to chitin. PMID

  14. Creation and characterization of an airway epithelial cell line for stable expression of CFTR variants

    PubMed Central

    Gottschalk, Laura B.; Vecchio-Pagan, Briana; Sharma, Neeraj; Han, Sangwoo T.; Franca, Arianna; Wohler, Elizabeth S.; Batista, Denise A.S.; Goff, Loyal A.; Cutting, Garry R.

    2016-01-01

    Background Analysis of the functional consequences and treatment response of rare CFTR variants is challenging due to the limited availability of primary airways cells. Methods A Flp recombination target (FRT) site for stable expression of CFTR was incorporated into an immortalized CF bronchial epithelial cell line (CFBE41o−). CFTR cDNA was integrated into the FRT site. Expression was evaluated by western blotting and confocal microscopy and function measured by short circuit current. RNA sequencing was used to compare the transcriptional profile of the resulting CF8Flp cell line to primary cells and tissues. Results Functional CFTR was expressed from integrated cDNA at the FRT site of the CF8Flp cell line at levels comparable to that seen in native airway cells. CF8Flp cells expressing WT-CFTR have a stable transcriptome comparable to that of primary cultured airway epithelial cells, including genes that play key roles in CFTR pathways. Conclusion CF8Flp cells provide a viable substitute for primary CF airway cells for the analysis of CFTR variants in a native context. PMID:26694805

  15. An investigation of the influence of cell topography on epithelial mechanical stresses during pulmonary airway reopening

    NASA Astrophysics Data System (ADS)

    Jacob, A. M.; Gaver, D. P.

    2005-03-01

    The goal of this study is to assess the local mechanical environment of the pulmonary epithelium in a computational model of airway reopening. To this end, the boundary element method (BEM) in conjunction with lubrication theory is implemented to assess the stationary-state behavior of a semi-infinite bubble traveling through a liquid-occluded parallel plate flow chamber lined with epithelial cells. The fluid occlusion is assumed to be Newtonian and inertia is neglected. The interactions between the microgeometry of the model airway's walls and the interfacial kinematics surrounding the bubble's tip result in a complex, spatially and temporally dependent stress distribution. The walls' nonplanar topography magnifies the normal and shear stresses and stress gradients. We find that decreasing the bubble's speed serves to increase the maximum normal stress and stress gradient but decrease the maximum shear stress and stress gradient. Our results give credence to the pressure-gradient-induced epithelial damage theory recently proposed by Bilek et al. [J. Appl. Physiol. 94, 770 (2003)] and Kay et al. [J. Appl. Physiol. 97, 269 (2004)]. We conclude that the amplified pressure gradients found in this study may be even more detrimental to the airway's cellular epithelium during airway reopening.

  16. An investigation of the influence of cell topography on epithelial mechanical stresses during pulmonary airway reopening.

    PubMed

    Jacob, A M; Gaver, D P

    2005-01-01

    The goal of this study is to assess the local mechanical environment of the pulmonary epithelium in a computational model of airway reopening. To this end, the boundary element method (BEM) in conjunction with lubrication theory is implemented to assess the stationary-state behavior of a semi-infinite bubble traveling through a liquid-occluded parallel plate flow chamber lined with epithelial cells. The fluid occlusion is assumed to be Newtonian and inertia is neglected. The interactions between the microgeometry of the model airway's walls and the interfacial kinematics surrounding the bubble's tip result in a complex, spatially and temporally dependent stress distribution. The walls' nonplanar topography magnifies the normal and shear stresses and stress gradients. We find that decreasing the bubble's speed serves to increase the maximum normal stress and stress gradient but decrease the maximum shear stress and stress gradient. Our results give credence to the pressure-gradient-induced epithelial damage theory recently proposed by Bilek et al. [J. Appl. Physiol. 94, 770 (2003)] and Kay et al. [J. Appl. Physiol. 97, 269 (2004)]. We conclude that the amplified pressure gradients found in this study may be even more detrimental to the airway's cellular epithelium during airway reopening. PMID:23745044

  17. Role of mitochondrial hydrogen peroxide induced by intermittent hypoxia in airway epithelial wound repair in vitro.

    PubMed

    Hamada, Satoshi; Sato, Atsuyasu; Hara-Chikuma, Mariko; Satooka, Hiroki; Hasegawa, Koichi; Tanimura, Kazuya; Tanizawa, Kiminobu; Inouchi, Morito; Handa, Tomohiro; Oga, Toru; Muro, Shigeo; Mishima, Michiaki; Chin, Kazuo

    2016-05-15

    The airway epithelium acts as a frontline barrier against various environmental insults and its repair process after airway injury is critical for the lung homeostasis restoration. Recently, the role of intracellular reactive oxygen species (ROS) as transcription-independent damage signaling has been highlighted in the wound repair process. Both conditions of continuous hypoxia and intermittent hypoxia (IH) induce ROS. Although IH is important in clinical settings, the roles of IH-induced ROS in the airway repair process have not been investigated. In this study, we firstly showed that IH induced mitochondrial hydrogen peroxide (H2O2) production and significantly decreased bronchial epithelial cell migration, prevented by catalase treatment in a wound scratch assay. RhoA activity was higher during repair process in the IH condition compared to in the normoxic condition, resulting in the cellular morphological changes shown by immunofluorescence staining: round cells, reduced central stress fiber numbers, pronounced cortical actin filament distributions, and punctate focal adhesions. These phenotypes were replicated by exogenous H2O2 treatment under the normoxic condition. Our findings confirmed the transcription-independent role of IH-induced intracellular ROS in the bronchial epithelial cell repair process and might have significant implications for impaired bronchial epithelial cell regeneration. PMID:27093911

  18. Effects of vitamin D on airway epithelial cell morphology and rhinovirus replication.

    PubMed

    Brockman-Schneider, Rebecca A; Pickles, Raymond J; Gern, James E

    2014-01-01

    Vitamin D has been linked to reduced risk of viral respiratory illness. We hypothesized that vitamin D could directly reduce rhinovirus (RV) replication in airway epithelium. Primary human bronchial epithelial cells (hBEC) were treated with vitamin D, and RV replication and gene expression were evaluated by quantitative PCR. Cytokine/chemokine secretion was measured by ELISA, and transepithelial resistance (TER) was determined using a voltohmmeter. Morphology was examined using immunohistochemistry. Vitamin D supplementation had no significant effects on RV replication, but potentiated secretion of CXCL8 and CXCL10 from infected or uninfected cells. Treatment with vitamin D in the form of 1,25(OH)2D caused significant changes in cell morphology, including thickening of the cell layers (median of 46.5 µm [35.0-69.0] vs. 30 µm [24.5-34.2], p<0.01) and proliferation of cytokeratin-5-expressing cells, as demonstrated by immunohistochemical analysis. Similar effects were seen for 25(OH)D. In addition to altering morphology, higher concentrations of vitamin D significantly upregulated small proline-rich protein (SPRR1β) expression (6.3 fold-induction, p<0.01), suggestive of squamous metaplasia. Vitamin D treatment of hBECs did not alter repair of mechanically induced wounds. Collectively, these findings indicate that vitamin D does not directly affect RV replication in airway epithelial cells, but can influence chemokine synthesis and alters the growth and differentiation of airway epithelial cells. PMID:24475177

  19. Effect of guaifenesin on mucin production, rheology, and mucociliary transport in differentiated human airway epithelial cells.

    PubMed

    Seagrave, JeanClare; Albrecht, Helmut; Park, Yong Sung; Rubin, Bruce; Solomon, Gail; Kim, K Chul

    2011-12-01

    Guaifenesin is widely used to alleviate symptoms of excessive mucus accumulation in the respiratory tract. However, its mechanism of action is poorly understood. The authors hypothesized that guaifenesin improves mucociliary clearance in humans by reducing mucin release, by decreasing mucus viscoelasticity, and by increasing mucociliary transport. To test these hypotheses, human differentiated airway epithelial cells, cultured at an air-liquid interface, were treated with clinically relevant concentrations of guaifenesin by addition to the basolateral medium. To evaluate the effect on mucin secretion, the authors used an anzyme-linked immunosorbent assay (ELISA) to measure the amounts of MUC5AC protein in apical surface fluid and cell lysates. To measure mucociliary transportability, additional cultures were treated for 1 or 6 hours with guaifenesin, and the movement of cell debris was measured from video data. Further, the authors measured mucus dynamic viscoelasticity using a micro cone and plate rheometer with nondestructive creep transformation. Guaifenesin suppressed mucin production in a dose-dependent manner at clinically relevant concentrations. The reduced mucin production was associated with increased mucociliary transport and decreased viscoelasticity of the mucus. Viability of the cultures was not significantly affected. These results suggest that guaifenesin could improve mucociliary clearance in humans by reducing the release and/or production of mucins, thereby altering mucus rheology. PMID:22044398

  20. Airway epithelial homeostasis and planar cell polarity signaling depend on multiciliated cell differentiation

    PubMed Central

    Vladar, Eszter K.; Nayak, Jayakar V.; Milla, Carlos E.; Axelrod, Jeffrey D.

    2016-01-01

    Motile airway cilia that propel contaminants out of the lung are oriented in a common direction by planar cell polarity (PCP) signaling, which localizes PCP protein complexes to opposite cell sides throughout the epithelium to orient cytoskeletal remodeling. In airway epithelia, PCP is determined in a 2-phase process. First, cell-cell communication via PCP complexes polarizes all cells with respect to the proximal-distal tissue axis. Second, during ciliogenesis, multiciliated cells (MCCs) undergo cytoskeletal remodeling to orient their cilia in the proximal direction. The second phase not only directs cilium polarization, but also consolidates polarization across the epithelium. Here, we demonstrate that in airway epithelia, PCP depends on MCC differentiation. PCP mutant epithelia have misaligned cilia, and also display defective barrier function and regeneration, indicating that PCP regulates multiple aspects of airway epithelial homeostasis. In humans, MCCs are often sparse in chronic inflammatory diseases, and these airways exhibit PCP dysfunction. The presence of insufficient MCCs impairs mucociliary clearance in part by disrupting PCP-driven polarization of the epithelium. Consistent with defective PCP, barrier function and regeneration are also disrupted. Pharmacological stimulation of MCC differentiation restores PCP and reverses these defects, suggesting its potential for broad therapeutic benefit in chronic inflammatory disease. PMID:27570836

  1. Bronchial Epithelial Cells Produce IL-5: Implications for Local Immune Responses in the Airways

    PubMed Central

    Wu, Carol A.; Peluso, John J.; Zhu, Li; Lingenheld, Elizabeth G.; Walker, Sharale T.; Puddington, Lynn

    2010-01-01

    IL-5 is a pleiotropic cytokine that promotes eosinophil differentiation and survival. While naïve bronchial epithelial cells (BEC) produce low levels of IL-5, the role of BEC-derived IL-5 in allergic airway inflammation is unknown. We now show that BEC, isolated from mice with OVA-induced allergic airway disease (AAD), produced elevated levels of IL-5 mRNA and protein as compared to BEC from naïve mice. To determine the contribution of BEC-derived IL-5 to effector responses in the airways, IL-5 deficient bone marrow chimeric mice were generated in which IL-5 expression was restricted to stromal (e.g. BEC) or hematopoietic cells. When subjected to AAD, IL-5 produced by BECs contributed to mucous metaplasia, airway eosinophilia, and OVA-specific IgA levels. Thus, IL-5 production by BEC can impact the microenvironment of the lung, modifying pathologic and protective immune responses in the airways. PMID:20494340

  2. Absence of inflammatory response from upper airway epithelial cells after X irradiation.

    PubMed

    Reiter, R; Deutschle, T; Wiegel, T; Riechelmann, H; Bartkowiak, D

    2009-03-01

    Radiotherapy of head and neck tumors causes adverse reactions in normal tissue, especially mucositis. The dose- and time-dependent response of upper airway cells to X radiation should be analyzed in terms of the pro-inflammatory potential. Immortalized BEAS-2B lung epithelial cells were treated with 2, 5 and 8 Gy. Out of 1232 genes, those that were transcribed differentially after 2, 6 and 24 h were assigned to biological themes according to the Gene Ontology Consortium. Enrichment of differentially regulated gene clusters was determined with GOTree ( http://bioinfo.vanderbilt.edu/gotm ). Eleven cytokines were measured in culture supernatants. The cell cycle response up to 24 h and induction of apoptosis up to 4 days after exposure were determined by flow cytometry. A significant dose- and time-dependent gene activation was observed for the categories response to DNA damage, oxidative stress, cell cycle arrest and cell death/apoptosis but not for immune/inflammatory response. This correlated with functional G(2) arrest and apoptosis. Pro-inflammatory cytokines accumulated in supernatants of control cells but not of X-irradiated cells. The complex gene expression pattern of X-irradiated airway epithelial cells is accompanied by cell cycle arrest and induction of apoptosis. In vivo, this may impair the epithelial barrier. mRNA and protein expression suggest at most an indirect contribution of epithelial cells to early radiogenic mucositis. PMID:19267554

  3. Alpha-1 Antitrypsin Mitigates the Inhibition of Airway Epithelial Cell Repair by Neutrophil Elastase.

    PubMed

    Garratt, Luke W; Sutanto, Erika N; Ling, Kak-Ming; Looi, Kevin; Iosifidis, Thomas; Martinovich, Kelly M; Shaw, Nicole C; Buckley, Alysia G; Kicic-Starcevich, Elizabeth; Lannigan, Francis J; Knight, Darryl A; Stick, Stephen M; Kicic, Anthony

    2016-03-01

    Neutrophil elastase (NE) activity is associated with many destructive lung diseases and is a predictor for structural lung damage in early cystic fibrosis (CF), which suggests normal maintenance of airway epithelium is prevented by uninhibited NE. However, limited data exist on how the NE activity in airways of very young children with CF affects function of the epithelia. The aim of this study was to determine if NE activity could inhibit epithelial homeostasis and repair and whether any functional effect was reversible by antiprotease alpha-1 antitrypsin (α1AT) treatment. Viability, inflammation, apoptosis, and proliferation were assessed in healthy non-CF and CF pediatric primary airway epithelial cells (pAECnon-CF and pAECCF, respectively) during exposure to physiologically relevant NE. The effect of NE activity on pAECCF wound repair was also assessed. We report that viability after 48 hours was significantly decreased by 100 nM NE in pAECnon-CF and pAECCF owing to rapid cellular detachment that was accompanied by inflammatory cytokine release. Furthermore, both phenotypes initiated an apoptotic response to 100 nM NE, whereas ≥ 50 nM NE activity significantly inhibited the proliferative capacity of cultures. Similar concentrations of NE also significantly inhibited wound repair of pAECCF, but this effect was reversed by the addition of α1AT. Collectively, our results demonstrate free NE activity is deleterious for epithelial homeostasis and support the hypothesis that proteases in the airway contribute directly to CF structural lung disease. Our results also highlight the need to investigate antiprotease therapies in early CF disease in more detail. PMID:26221769

  4. The Pseudomonas toxin pyocyanin inhibits the Dual oxidase-based antimicrobial system as it imposes oxidative stress on airway epithelial cells1

    PubMed Central

    Rada, Balázs; Lekstrom, Kristen; Damian, Sorin; Dupuy, Corinne; Leto, Thomas L.

    2009-01-01

    The dual oxidase-thiocyanate-lactoperoxidase (Duox/SCN−/LPO) system generates the microbicidal oxidant hypothiocyanite in the airway surface liquid by using LPO, thiocyanate, and Duox-derived hydrogen peroxide released from the apical surface of the airway epithelium. This system is effective against several microorganisms that infect airways of cystic fibrosis and other immunocompromised patients. We show here that exposure of airway epithelial cells to Pseudomonas aeruginosa obtained from long-term cultures inhibits Duox1-dependent hydrogen peroxide release, suggesting some microbial factor suppresses Duox activity. These inhibitory effects were not seen with the pyocyanin-deficient P. aeruginosa strain, PA14 Phz1/2. We showed that purified pyocyanin, a redox-active virulence factor produced by P. aeruginosa, inhibits human airway cell Duox activity by depleting intracellular stores of NADPH, as it generates intracellular superoxide. Long-term exposure of human airway (primary normal human bronchial and NCI-H292) cells to pyocyanin also blocks induction of Duox1 by Th2 cytokines (IL-4, IL-13), which was prevented by the anti-oxidants glutathione and N-acetylcysteine. Furthermore, we showed that low concentrations of pyocyanin blocked killing of wild-type P. aeruginosa by the Duox/SCN-/LPO system on primary normal human bronchial epithelial cells. Thus, pyocyanin can subvert Pseudomonas killing by the Duox-based system as it imposes oxidative stress on the host. We also show that lactoperoxidase can oxidize pyocyanin, thereby diminishing its cytotoxicity. These data establish a novel role for pyocyanin in the survival of Pseudomonas aeruginosa in human airways through competitive redox-based reactions between the pathogen and host. PMID:18802092

  5. Astragalin inhibits airway eotaxin-1 induction and epithelial apoptosis through modulating oxidative stress-responsive MAPK signaling

    PubMed Central

    2014-01-01

    Background Eotaxin proteins are a potential therapeutic target in treating the peribronchial eosinophilia associated with allergic airway diseases. Since inflammation is often associated with an increased generation of reactive oxygen species (ROS), oxidative stress is a mechanistically imperative factor in asthma. Astragalin (kaempferol-3-O-glucoside) is a flavonoid with anti-inflammatory activity and newly found in persimmon leaves and green tea seeds. This study elucidated that astragalin inhibited endotoxin-induced oxidative stress leading to eosinophilia and epithelial apoptosis in airways. Methods Airway epithelial BEAS-2B cells were exposed to lipopolysaccharide (LPS) in the absence and presence of 1–20 μM astragalin. Western blot and immunocytochemical analyses were conducted to determine induction of target proteins. Cell and nuclear staining was also performed for ROS production and epithelial apoptosis. Results When airway epithelial cells were exposed to 2 μg/ml LPS, astragalin nontoxic at ≤20 μM suppressed cellular induction of Toll-like receptor 4 (TLR4) and ROS production enhanced by LPS. Both LPS and H2O2 induced epithelial eotaxin-1 expression, which was blocked by astragalin. LPS activated and induced PLCγ1, PKCβ2, and NADPH oxidase subunits of p22phox and p47phox in epithelial cells and such activation and induction were demoted by astragalin or TLR4 inhibition antagonizing eotaxin-1 induction. H2O2-upregulated phosphorylation of JNK and p38 MAPK was dampened by adding astragalin to epithelial cells, while this compound enhanced epithelial activation of Akt and ERK. H2O2 and LPS promoted epithelial apoptosis concomitant with nuclear condensation or caspase-3 activation, which was blunted by astragalin. Conclusions Astragalin ameliorated oxidative stress-associated epithelial eosinophilia and apoptosis through disturbing TLR4-PKCβ2-NADPH oxidase-responsive signaling. Therefore, astragalin may be a potent agent antagonizing endotoxin

  6. Leptin enhances ICAM-1 expression, induces migration and cytokine synthesis, and prolongs survival of human airway epithelial cells.

    PubMed

    Suzukawa, Maho; Koketsu, Rikiya; Baba, Shintaro; Igarashi, Sayaka; Nagase, Hiroyuki; Yamaguchi, Masao; Matsutani, Noriyuki; Kawamura, Masafumi; Shoji, Shunsuke; Hebisawa, Akira; Ohta, Ken

    2015-10-15

    There is rising interest in how obesity affects respiratory diseases, since epidemiological findings indicate a strong relationship between the two conditions. Leptin is a potent adipokine produced mainly by adipocytes. It regulates energy storage and expenditure and also induces inflammation. Previous studies have shown that leptin is able to activate inflammatory cells such as lymphocytes and granulocytes, but little is known about its effect on lung structural cells. The present study investigated the effects of leptin on human airway epithelial cells by using human primary airway epithelial cells and a human airway epithelial cell line, BEAS-2B. Flow cytometry showed enhanced ICAM-1 expression by both of those cells in response to leptin, and that effect was abrogated by dexamethasone or NF-κB inhibitor. Flow cytometry and quantitative PCR showed that airway epithelial cells expressed leptin receptor (Ob-R), whose expression level was downregulated by leptin itself. Multiplex cytokine analysis demonstrated enhanced production of CCL11, G-CSF, VEGF, and IL-6 by BEAS-2B cells stimulated with leptin. Furthermore, transfection of Ob-R small interference RNA decreased the effect of leptin on CCL11 production as assessed by quantitative PCR. Finally, leptin induced migration of primary airway epithelial cells toward leptin, suppressed BEAS-2B apoptosis induced with TNF-α and IFN-γ, and enhanced proliferation of primary airway epithelial cells. In summary, leptin was able to directly activate human airway epithelial cells by binding to Ob-R and by NF-κB activation, resulting in upregulation of ICAM-1 expression, induction of CCL11, VEGF, G-CSF, and IL-6 synthesis, induction of migration, inhibition of apoptosis, and enhancement of proliferation. PMID:26276826

  7. Ineffective correction of PPARγ signaling in cystic fibrosis airway epithelial cells undergoing repair.

    PubMed

    Bou Saab, J; Bacchetta, M; Chanson, M

    2016-09-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) represents a potential target to treat airway mucus hypersecretion in cystic fibrosis (CF). We aimed to determine if PPARγ is altered in CF human airway epithelial cells (HAECs), if PPARγ contributes to mucin expression and HAEC differentiation, and if PPARγ ligand therapy corrects the CF phenotype. To this end, well-differentiated CF and NCF HAEC primary cultures were wounded to monitor the expression of key genes involved in PPARγ activation and mucus homeostasis, and to evaluate the effect of a PPARγ agonist, at different times of repair. Hydroxyprostaglandin dehydrogenase (HPGD) converts prostaglandin E2 to 15-keto PGE2 (15kPGE2), an endogenous PPARγ ligand. Interestingly, PPARγ and HPGD expression dramatically decreased in CF HAECs. These changes were accompanied by an increase in the expression of MUC5B. The correlation between PPARγ and MUC5B was confirmed in an airway epithelial cell line after CFTR knock-down. Exposure of HAECs to 15kPGE2 did not correct the CF phenotype but revealed a defect in the process of basal cell (BC) differentiation. The HPGD/PPARγ axis is deregulated in primary HAEC cultures from CF patients, which may impact the maturation of BCs to differentiated luminal cells. Importantly, PPARγ therapy was inefficient in correcting the CF defect. PMID:27484450

  8. Image-based finite element modeling of alveolar epithelial cell injury during airway reopening.

    PubMed

    Dailey, H L; Ricles, L M; Yalcin, H C; Ghadiali, S N

    2009-01-01

    The acute respiratory distress syndrome (ARDS) is characterized by fluid accumulation in small pulmonary airways. The reopening of these fluid-filled airways involves the propagation of an air-liquid interface that exerts injurious hydrodynamic stresses on the epithelial cells (EpC) lining the airway walls. Previous experimental studies have demonstrated that these hydrodynamic stresses may cause rupture of the plasma membrane (i.e., cell necrosis) and have postulated that cell morphology plays a role in cell death. However, direct experimental measurement of stress and strain within the cell is intractable, and limited data are available on the mechanical response (i.e., deformation) of the epithelium during airway reopening. The goal of this study is to use image-based finite element models of cell deformation during airway reopening to investigate how cell morphology and mechanics influence the risk of cell injury/necrosis. Confocal microscopy images of EpC in subconfluent and confluent monolayers were used to generate morphologically accurate three-dimensional finite element models. Hydrodynamic stresses on the cells were calculated from boundary element solutions of bubble propagation in a fluid-filled parallel-plate flow channel. Results indicate that for equivalent cell mechanical properties and hydrodynamic load conditions, subconfluent cells develop higher membrane strains than confluent cells. Strain magnitudes were also found to decrease with increasing stiffness of the cell and membrane/cortex region but were most sensitive to changes in the cell's interior stiffness. These models may be useful in identifying pharmacological treatments that mitigate cell injury during airway reopening by altering specific biomechanical properties of the EpC. PMID:19008489

  9. Regulation of Cl^- Channels in Normal and Cystic Fibrosis Airway Epithelial Cells by Extracellular ATP

    NASA Astrophysics Data System (ADS)

    Stutts, M. J.; Chinet, T. C.; Mason, S. J.; Fullton, J. M.; Clarke, L. L.; Boucher, R. C.

    1992-03-01

    The rate of Cl^- secretion by human airway epithelium is determined, in part, by apical cell membrane Cl^- conductance. In cystic fibrosis airway epithelia, defective regulation of Cl^- conductance decreases the capability to secrete Cl^-. Here we report that extracytosolic ATP in the luminal bath of cultured human airway epithelia increased transepithelial Cl^- secretion and apical membrane Cl^- permeability. Single-channel studies in excised membrane patches revealed that ATP increased the open probability of outward rectifying Cl^- channels. The latter effect occurs through a receptor mechanism that requires no identified soluble second messengers and is insensitive to probes of G protein function. These results demonstrate a mode of regulation of anion channels by binding ATP at the extracellular surface. Regulation of Cl^- conductance by external ATP is preserved in cystic fibrosis airway epithelia.

  10. Bat airway epithelial cells: a novel tool for the study of zoonotic viruses.

    PubMed

    Eckerle, Isabella; Ehlen, Lukas; Kallies, René; Wollny, Robert; Corman, Victor M; Cottontail, Veronika M; Tschapka, Marco; Oppong, Samuel; Drosten, Christian; Müller, Marcel A

    2014-01-01

    Bats have been increasingly recognized as reservoir of important zoonotic viruses. However, until now many attempts to isolate bat-borne viruses in cell culture have been unsuccessful. Further, experimental studies on reservoir host species have been limited by the difficulty of rearing these species. The epithelium of the respiratory tract plays a central role during airborne transmission, as it is the first tissue encountered by viral particles. Although several cell lines from bats were established recently, no well-characterized, selectively cultured airway epithelial cells were available so far. Here, primary cells and immortalized cell lines from bats of the two important suborders Yangochiroptera and Yinpterochiroptera, Carollia perspicillata (Seba's short-tailed bat) and Eidolon helvum (Straw-colored fruit bat), were successfully cultured under standardized conditions from both fresh and frozen organ specimens by cell outgrowth of organ explants and by the use of serum-free primary cell culture medium. Cells were immortalized to generate permanent cell lines. Cells were characterized for their epithelial properties such as expression of cytokeratin and tight junctions proteins and permissiveness for viral infection with Rift-Valley fever virus and vesicular stomatitis virus Indiana. These cells can serve as suitable models for the study of bat-borne viruses and complement cell culture models for virus infection in human airway epithelial cells. PMID:24454736

  11. Intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells

    SciTech Connect

    Verhaeghe, Catherine; Tabruyn, Sebastien P.; Oury, Cecile; Bours, Vincent . E-mail: vbours@ulg.ac.be; Griffioen, Arjan W.

    2007-05-11

    Cystic fibrosis is a common genetic disorder characterized by a severe lung inflammation and fibrosis leading to the patient's death. Enhanced angiogenesis in cystic fibrosis (CF) tissue has been suggested, probably caused by the process of inflammation, as similarly described in asthma and chronic bronchitis. The present study demonstrates an intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells. Microarray experiments showed that CF airway epithelial cells expressed several angiogenic factors such as VEGF-A, VEGF-C, bFGF, and PLGF at higher levels than control cells. These data were confirmed by real-time quantitative PCR and, at the protein level, by ELISA. Conditioned media of these cystic fibrosis cells were able to induce proliferation, migration and sprouting of cultured primary endothelial cells. This report describes for the first time that cystic fibrosis epithelial cells have an intrinsic angiogenic activity. Since excess of angiogenesis is correlated with more severe pulmonary disease, our results could lead to the development of new therapeutic applications.

  12. Bat Airway Epithelial Cells: A Novel Tool for the Study of Zoonotic Viruses

    PubMed Central

    Eckerle, Isabella; Ehlen, Lukas; Kallies, René; Wollny, Robert; Corman, Victor M.; Cottontail, Veronika M.; Tschapka, Marco; Oppong, Samuel; Drosten, Christian; Müller, Marcel A.

    2014-01-01

    Bats have been increasingly recognized as reservoir of important zoonotic viruses. However, until now many attempts to isolate bat-borne viruses in cell culture have been unsuccessful. Further, experimental studies on reservoir host species have been limited by the difficulty of rearing these species. The epithelium of the respiratory tract plays a central role during airborne transmission, as it is the first tissue encountered by viral particles. Although several cell lines from bats were established recently, no well-characterized, selectively cultured airway epithelial cells were available so far. Here, primary cells and immortalized cell lines from bats of the two important suborders Yangochiroptera and Yinpterochiroptera, Carollia perspicillata (Seba's short-tailed bat) and Eidolon helvum (Straw-colored fruit bat), were successfully cultured under standardized conditions from both fresh and frozen organ specimens by cell outgrowth of organ explants and by the use of serum-free primary cell culture medium. Cells were immortalized to generate permanent cell lines. Cells were characterized for their epithelial properties such as expression of cytokeratin and tight junctions proteins and permissiveness for viral infection with Rift-Valley fever virus and vesicular stomatitis virus Indiana. These cells can serve as suitable models for the study of bat-borne viruses and complement cell culture models for virus infection in human airway epithelial cells. PMID:24454736

  13. Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review

    PubMed Central

    Croft, Carys A.; Culibrk, Luka; Moore, Margo M.; Tebbutt, Scott J.

    2016-01-01

    Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis. PMID:27092126

  14. Soft TCPTP Agonism—Novel Target to Rescue Airway Epithelial Integrity by Exogenous Spermidine

    PubMed Central

    Ghisalberti, Carlo A.; Borzì, Rosa M.; Cetrullo, Silvia; Flamigni, Flavio; Cairo, Gaetano

    2016-01-01

    A reparative approach of disrupted epithelium in obstructive airway diseases, namely asthma and chronic obstructive pulmonary disease (COPD), may afford protection and long-lasting results compared to conventional therapies, e.g., corticosteroids or immunosuppressant drugs. Here, we propose the polyamine spermidine as a novel therapeutic agent in airways diseases, based on a recently identified mode of action: T-cell protein tyrosine phosphatase (TCPTP) agonism. It may include and surpass single-inhibitors of stress and secondary growth factor pathway signaling, i.e., the new medicinal chemistry in lung diseases. Enhanced polyamine biosynthesis has been charged with aggravating prognosis by competing for L-arginine at detriment of nitric oxide (NO) synthesis with bronchoconstrictive effects. Although excess spermine, a higher polyamine, is harmful to airways physiology, spermidine can pivot the cell homeostasis during stress conditions by the activation of TCPTP. In fact, the dephosphorylating activity of TCPTP inhibits the signaling cascade that leads to the expression of genes involved in detachment and epithelial-to-mesenchymal transition (EMT), and increases the expression of adhesion and tight junction proteins, thereby enhancing the barrier functionality in inflammation-prone tissues. Moreover, a further beneficial effect of spermidine may derive from its ability to promote autophagy, possibly in a TCPTP-dependent way. Since doses of spermidine in the micromolar range are sufficient to activate TCPTP, low amounts of spermidine administered in sustained release modality may provide an optimal pharmacologic profile for the treatment of obstructive airway diseases. PMID:27375482

  15. Soft TCPTP Agonism-Novel Target to Rescue Airway Epithelial Integrity by Exogenous Spermidine.

    PubMed

    Ghisalberti, Carlo A; Borzì, Rosa M; Cetrullo, Silvia; Flamigni, Flavio; Cairo, Gaetano

    2016-01-01

    A reparative approach of disrupted epithelium in obstructive airway diseases, namely asthma and chronic obstructive pulmonary disease (COPD), may afford protection and long-lasting results compared to conventional therapies, e.g., corticosteroids or immunosuppressant drugs. Here, we propose the polyamine spermidine as a novel therapeutic agent in airways diseases, based on a recently identified mode of action: T-cell protein tyrosine phosphatase (TCPTP) agonism. It may include and surpass single-inhibitors of stress and secondary growth factor pathway signaling, i.e., the new medicinal chemistry in lung diseases. Enhanced polyamine biosynthesis has been charged with aggravating prognosis by competing for L-arginine at detriment of nitric oxide (NO) synthesis with bronchoconstrictive effects. Although excess spermine, a higher polyamine, is harmful to airways physiology, spermidine can pivot the cell homeostasis during stress conditions by the activation of TCPTP. In fact, the dephosphorylating activity of TCPTP inhibits the signaling cascade that leads to the expression of genes involved in detachment and epithelial-to-mesenchymal transition (EMT), and increases the expression of adhesion and tight junction proteins, thereby enhancing the barrier functionality in inflammation-prone tissues. Moreover, a further beneficial effect of spermidine may derive from its ability to promote autophagy, possibly in a TCPTP-dependent way. Since doses of spermidine in the micromolar range are sufficient to activate TCPTP, low amounts of spermidine administered in sustained release modality may provide an optimal pharmacologic profile for the treatment of obstructive airway diseases. PMID:27375482

  16. IL-1α mediates cellular cross-talk in the airway epithelial mesenchymal trophic unit

    PubMed Central

    Hill, Alison R.; Donaldson, Jessica E.; Blume, Cornelia; Smithers, Natalie; Tezera, Liku; Tariq, Kamran; Dennison, Patrick; Rupani, Hitasha; Edwards, Matthew J.; Howarth, Peter H.; Grainge, Christopher; Davies, Donna E.; Swindle, Emily J.

    2016-01-01

    ABSTRACT The bronchial epithelium and underlying fibroblasts form an epithelial mesenchymal trophic unit (EMTU) which controls the airway microenvironment. We hypothesized that cell-cell communication within the EMTU propagates and amplifies the innate immune response to respiratory viral infections. EMTU co-culture models incorporating polarized (16HBE14o-) or differentiated primary human bronchial epithelial cells (HBECs) and fibroblasts were challenged with double-stranded RNA (dsRNA) or rhinovirus. In the polarized EMTU model, dsRNA affected ionic but not macromolecular permeability or cell viability. Compared with epithelial monocultures, dsRNA-stimulated pro-inflammatory mediator release was synergistically enhanced in the basolateral compartment of the EMTU model, with the exception of IL-1α which was unaffected by the presence of fibroblasts. Blockade of IL-1 signaling with IL-1 receptor antagonist (IL-1Ra) completely abrogated dsRNA-induced basolateral release of mediators except CXCL10. Fibroblasts were the main responders to epithelial-derived IL-1 since exogenous IL-1α induced pro-inflammatory mediator release from fibroblast but not epithelial monocultures. Our findings were confirmed in a differentiated EMTU model where rhinovirus infection of primary HBECs and fibroblasts resulted in synergistic induction of basolateral IL-6 that was significantly abrogated by IL-1Ra. This study provides the first direct evidence of integrated IL-1 signaling within the EMTU to propagate inflammatory responses to viral infection.

  17. Ets homologous factor regulates pathways controlling response to injury in airway epithelial cells.

    PubMed

    Fossum, Sara L; Mutolo, Michael J; Yang, Rui; Dang, Hong; O'Neal, Wanda K; Knowles, Michael R; Leir, Shih-Hsing; Harris, Ann

    2014-12-16

    Ets homologous factor (EHF) is an Ets family transcription factor expressed in many epithelial cell types including those lining the respiratory system. Disruption of the airway epithelium is central to many lung diseases, and a network of transcription factors coordinates its normal function. EHF can act as a transcriptional activator or a repressor, though its targets in lung epithelial cells are largely uncharacterized. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq), showed that the majority of EHF binding sites in lung epithelial cells are intergenic or intronic and coincide with putative enhancers, marked by specific histone modifications. EHF occupies many genomic sites that are close to genes involved in intercellular and cell-matrix adhesion. RNA-seq after EHF depletion or overexpression showed significant alterations in the expression of genes involved in response to wounding. EHF knockdown also targeted genes in pathways of epithelial development and differentiation and locomotory behavior. These changes in gene expression coincided with alterations in cellular phenotype including slowed wound closure and increased transepithelial resistance. Our data suggest that EHF regulates gene pathways critical for epithelial response to injury, including those involved in maintenance of barrier function, inflammation and efficient wound repair. PMID:25414352

  18. IL-1α mediates cellular cross-talk in the airway epithelial mesenchymal trophic unit.

    PubMed

    Hill, Alison R; Donaldson, Jessica E; Blume, Cornelia; Smithers, Natalie; Tezera, Liku; Tariq, Kamran; Dennison, Patrick; Rupani, Hitasha; Edwards, Matthew J; Howarth, Peter H; Grainge, Christopher; Davies, Donna E; Swindle, Emily J

    2016-01-01

    The bronchial epithelium and underlying fibroblasts form an epithelial mesenchymal trophic unit (EMTU) which controls the airway microenvironment. We hypothesized that cell-cell communication within the EMTU propagates and amplifies the innate immune response to respiratory viral infections. EMTU co-culture models incorporating polarized (16HBE14o-) or differentiated primary human bronchial epithelial cells (HBECs) and fibroblasts were challenged with double-stranded RNA (dsRNA) or rhinovirus. In the polarized EMTU model, dsRNA affected ionic but not macromolecular permeability or cell viability. Compared with epithelial monocultures, dsRNA-stimulated pro-inflammatory mediator release was synergistically enhanced in the basolateral compartment of the EMTU model, with the exception of IL-1α which was unaffected by the presence of fibroblasts. Blockade of IL-1 signaling with IL-1 receptor antagonist (IL-1Ra) completely abrogated dsRNA-induced basolateral release of mediators except CXCL10. Fibroblasts were the main responders to epithelial-derived IL-1 since exogenous IL-1α induced pro-inflammatory mediator release from fibroblast but not epithelial monocultures. Our findings were confirmed in a differentiated EMTU model where rhinovirus infection of primary HBECs and fibroblasts resulted in synergistic induction of basolateral IL-6 that was significantly abrogated by IL-1Ra. This study provides the first direct evidence of integrated IL-1 signaling within the EMTU to propagate inflammatory responses to viral infection. PMID:27583193

  19. Liquid Movement Across the Surface Epithelium of Large Airways

    PubMed Central

    Chambers, Lucy A.; Rollins, Brett M.; Tarran, Robert

    2009-01-01

    The cystic fibrosis conductance regulator CFTR gene is found on chromosome 7 (Kerem et al., 1989; Riordan et al., 1989) and encodes for a 1,480 amino acid protein which is present in the plasma membrane of epithelial cells (Anderson et al., 1992). This protein appears to have many functions, but a unifying theme is that it acts as a protein kinase C- and cyclic AMP-regulated Cl- channel (Winpenny et al., 1995; Jia et al., 1997). In the superficial epithelium of the conducting airways, CFTR is involved in Cl- secretion (Boucher, 2003) and also acts as a regulator of the epithelial Na+ channel (ENaC) and hence Na+ absorption (Boucher et al., 1986; Stutts et al., 1995). In this chapter, we will discuss the regulation of these two ion channels, and how they can influence liquid movement across the superficial airway epithelium. PMID:17692578

  20. GTP-Binding Proteins Inhibit cAMP Activation of Chloride Channels in Cystic Fibrosis Airway Epithelial Cells

    NASA Astrophysics Data System (ADS)

    Schwiebert, Erik M.; Kizer, Neil; Gruenert, Dieter C.; Stanton, Bruce A.

    1992-11-01

    Cystic fibrosis (CF) is a genetic disease characterized, in part, by defective regulation of Cl^- secretion by airway epithelial cells. In CF, cAMP does not activate Cl^- channels in the apical membrane of airway epithelial cells. We report here whole-cell patch-clamp studies demonstrating that pertussis toxin, which uncouples heterotrimeric GTP-binding proteins (G proteins) from their receptors, and guanosine 5'-[β-thio]diphosphate, which prevents G proteins from interacting with their effectors, increase Cl^- currents and restore cAMP-activated Cl^- currents in airway epithelial cells isolated from CF patients. In contrast, the G protein activators guanosine 5'-[γ-thio]triphosphate and AlF^-_4 reduce Cl^- currents and inhibit cAMP from activating Cl^- currents in normal airway epithelial cells. In CF cells treated with pertussis toxin or guanosine 5'-[β-thio]diphosphate and in normal cells, cAMP activates a Cl^- conductance that has properties similar to CF transmembrane-conductance regulator Cl^- channels. We conclude that heterotrimeric G proteins inhibit cAMP-activated Cl^- currents in airway epithelial cells and that modulation of the inhibitory G protein signaling pathway may have the therapeutic potential for improving cAMP-activated Cl^- secretion in CF.

  1. The innate immune function of airway epithelial cells in inflammatory lung disease.

    PubMed

    Hiemstra, Pieter S; McCray, Paul B; Bals, Robert

    2015-04-01

    The airway epithelium is now considered to be central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as the first barrier in the defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. Herein, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, chronic obstructive pulmonary fibrosis and cystic fibrosis will be discussed. PMID:25700381

  2. The innate immune function of airway epithelial cells in inflammatory lung disease

    PubMed Central

    Hiemstra, Pieter S.; McCray, Paul B.; Bals, Robert

    2016-01-01

    The airway epithelium is now considered central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as a first barrier in the defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. In the review, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, COPD and cystic fibrosis, are discussed. PMID:25700381

  3. Disruption of β-catenin/CBP signaling inhibits human airway epithelial-mesenchymal transition and repair.

    PubMed

    Moheimani, Fatemeh; Roth, Hollis M; Cross, Jennifer; Reid, Andrew T; Shaheen, Furquan; Warner, Stephanie M; Hirota, Jeremy A; Kicic, Anthony; Hallstrand, Teal S; Kahn, Michael; Stick, Stephen M; Hansbro, Philip M; Hackett, Tillie-Louise; Knight, Darryl A

    2015-11-01

    The epithelium of asthmatics is characterized by reduced expression of E-cadherin and increased expression of the basal cell markers ck-5 and p63 that is indicative of a relatively undifferentiated repairing epithelium. This phenotype correlates with increased proliferation, compromised wound healing and an enhanced capacity to undergo epithelial-mesenchymal transition (EMT). The transcription factor β-catenin plays a vital role in epithelial cell differentiation and regeneration, depending on the co-factor recruited. Transcriptional programs driven by the β-catenin/CBP axis are critical for maintaining an undifferentiated and proliferative state, whereas the β-catenin/p300 axis is associated with cell differentiation. We hypothesized that disrupting the β-catenin/CBP signaling axis would promote epithelial differentiation and inhibit EMT. We treated monolayer cultures of human airway epithelial cells with TGFβ1 in the presence or absence of the selective small molecule ICG-001 to inhibit β-catenin/CBP signaling. We used western blots to assess expression of an EMT signature, CBP, p300, β-catenin, fibronectin and ITGβ1 and scratch wound assays to assess epithelial cell migration. Snai-1 and -2 expressions were determined using q-PCR. Exposure to TGFβ1 induced EMT, characterized by reduced E-cadherin expression with increased expression of α-smooth muscle actin and EDA-fibronectin. Either co-treatment or therapeutic administration of ICG-001 completely inhibited TGFβ1-induced EMT. ICG-001 also reduced the expression of ck-5 and -19 independent of TGFβ1. Exposure to ICG-001 significantly inhibited epithelial cell proliferation and migration, coincident with a down regulation of ITGβ1 and fibronectin expression. These data support our hypothesis that modulating the β-catenin/CBP signaling axis plays a key role in epithelial plasticity and function. PMID:26315281

  4. Reduced airway surface pH impairs bacterial killing in the porcine cystic fibrosis lung.

    PubMed

    Pezzulo, Alejandro A; Tang, Xiao Xiao; Hoegger, Mark J; Alaiwa, Mahmoud H Abou; Ramachandran, Shyam; Moninger, Thomas O; Karp, Phillip H; Wohlford-Lenane, Christine L; Haagsman, Henk P; van Eijk, Martin; Bánfi, Botond; Horswill, Alexander R; Stoltz, David A; McCray, Paul B; Welsh, Michael J; Zabner, Joseph

    2012-07-01

    Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Although bacterial lung infection and the resulting inflammation cause most of the morbidity and mortality, how the loss of CFTR function first disrupts airway host defence has remained uncertain. To investigate the abnormalities that impair elimination when a bacterium lands on the pristine surface of a newborn CF airway, we interrogated the viability of individual bacteria immobilized on solid grids and placed onto the airway surface. As a model, we studied CF pigs, which spontaneously develop hallmark features of CF lung disease. At birth, their lungs lack infection and inflammation, but have a reduced ability to eradicate bacteria. Here we show that in newborn wild-type pigs, the thin layer of airway surface liquid (ASL) rapidly kills bacteria in vivo, when removed from the lung and in primary epithelial cultures. Lack of CFTR reduces bacterial killing. We found that the ASL pH was more acidic in CF pigs, and reducing pH inhibited the antimicrobial activity of ASL. Reducing ASL pH diminished bacterial killing in wild-type pigs, and, conversely, increasing ASL pH rescued killing in CF pigs. These results directly link the initial host defence defect to the loss of CFTR, an anion channel that facilitates HCO(3)(-) transport. Without CFTR, airway epithelial HCO(3)(-) secretion is defective, the ASL pH falls and inhibits antimicrobial function, and thereby impairs the killing of bacteria that enter the newborn lung. These findings suggest that increasing ASL pH might prevent the initial infection in patients with CF, and that assaying bacterial killing could report on the benefit of therapeutic interventions. PMID:22763554

  5. Reduced Airway Surface pH Impairs Bacterial Killing in the Porcine Cystic Fibrosis Lung

    PubMed Central

    Pezzulo, Alejandro A.; Tang, Xiao Xiao; Hoegger, Mark J.; Abou Alaiwa, Mahmoud H.; Ramachandran, Shyam; Moninger, Thomas O.; Karp, Phillip H.; Wohlford-Lenane, Christine L.; Haagsman, Henk P.; van Eijk, Martin; Bánfi, Botond; Horswill, Alexander R.; Stoltz, David A.; McCray, Paul B.; Welsh, Michael J.; Zabner, Joseph

    2012-01-01

    Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene 1. Although bacterial lung infection and the resulting inflammation cause most of the morbidity and mortality, how loss of CFTR first disrupts airway host defense has remained uncertain 2–6. We asked what abnormalities impair eradication when a bacterium lands on the pristine surface of a newborn CF airway? To investigate these defects, we interrogated the viability of individual bacteria immobilized on solid grids and placed on the airway surface. As a model we studied CF pigs, which spontaneously develop hallmark features of CF lung disease 7,8. At birth, their lungs lack infection and inflammation, but have a reduced ability to eradicate bacteria 8. Here we show that in newborn wild-type pigs, the thin layer of airway surface liquid (ASL) rapidly killed bacteria in vivo, when removed from the lung, and in primary epithelial cultures. Lack of CFTR reduced bacterial killing. We found that ASL pH was more acidic in CF, and reducing pH inhibited the antimicrobial activity of ASL. Reducing ASL pH diminished bacterial killing in wild-type pigs, and increasing ASL pH rescued killing in CF pigs. These results directly link the initial host defense defect to loss of CFTR, an anion channel that facilitates HCO3− transport 9–13. Without CFTR, airway epithelial HCO3− secretion is defective, ASL pH falls and inhibits antimicrobial function, and thereby impairs killing of bacteria that enter the newborn lung. These findings suggest that increasing ASL pH might prevent the initial infection in patients with CF and that assaying bacterial killing could report on the benefit of therapeutic interventions. PMID:22763554

  6. Cigarette Smoke Modulates Expression of Human Rhinovirus-Induced Airway Epithelial Host Defense Genes

    PubMed Central

    Proud, David; Hudy, Magdalena H.; Wiehler, Shahina; Zaheer, Raza S.; Amin, Minaa A.; Pelikan, Jonathan B.; Tacon, Claire E.; Tonsaker, Tabitha O.; Walker, Brandie L.; Kooi, Cora; Traves, Suzanne L.; Leigh, Richard

    2012-01-01

    Human rhinovirus (HRV) infections trigger acute exacerbations of chronic obstructive pulmonary disease (COPD) and asthma. The human airway epithelial cell is the primary site of HRV infection and responds to infection with altered expression of multiple genes, the products of which could regulate the outcome to infection. Cigarette smoking aggravates asthma symptoms, and is also the predominant risk factor for the development and progression of COPD. We, therefore, examined whether cigarette smoke extract (CSE) modulates viral responses by altering HRV-induced epithelial gene expression. Primary cultures of human bronchial epithelial cells were exposed to medium alone, CSE alone, purified HRV-16 alone or to HRV-16+ CSE. After 24 h, supernatants were collected and total cellular RNA was isolated. Gene array analysis was performed to examine mRNA expression. Additional experiments, using real-time RT-PCR, ELISA and/or western blotting, validated altered expression of selected gene products. CSE and HRV-16 each induced groups of genes that were largely independent of each other. When compared to gene expression in response to CSE alone, cells treated with HRV+CSE showed no obvious differences in CSE-induced gene expression. By contrast, compared to gene induction in response to HRV-16 alone, cells exposed to HRV+CSE showed marked suppression of expression of a number of HRV-induced genes associated with various functions, including antiviral defenses, inflammation, viral signaling and airway remodeling. These changes were not associated with altered expression of type I or type III interferons. Thus, CSE alters epithelial responses to HRV infection in a manner that may negatively impact antiviral and host defense outcomes. PMID:22808255

  7. Pseudomonas aeruginosa Induced Airway Epithelial Injury Drives Fibroblast Activation: A Mechanism in Chronic Lung Allograft Dysfunction.

    PubMed

    Borthwick, L A; Suwara, M I; Carnell, S C; Green, N J; Mahida, R; Dixon, D; Gillespie, C S; Cartwright, T N; Horabin, J; Walker, A; Olin, E; Rangar, M; Gardner, A; Mann, J; Corris, P A; Mann, D A; Fisher, A J

    2016-06-01

    Bacterial infections after lung transplantation cause airway epithelial injury and are associated with an increased risk of developing bronchiolitis obliterans syndrome. The damaged epithelium is a source of alarmins that activate the innate immune system, yet their ability to activate fibroblasts in the development of bronchiolitis obliterans syndrome has not been evaluated. Two epithelial alarmins were measured longitudinally in bronchoalveolar lavages from lung transplant recipients who developed bronchiolitis obliterans syndrome and were compared to stable controls. In addition, conditioned media from human airway epithelial cells infected with Pseudomonas aeruginosa was applied to lung fibroblasts and inflammatory responses were determined. Interleukin-1 alpha (IL-1α) was increased in bronchoalveolar lavage of lung transplant recipients growing P. aeruginosa (11.5 [5.4-21.8] vs. 2.8 [0.9-9.4] pg/mL, p < 0.01) and was significantly elevated within 3 months of developing bronchiolitis obliterans syndrome (8.3 [1.4-25.1] vs. 3.6 [0.6-17.1] pg/mL, p < 0.01), whereas high mobility group protein B1 remained unchanged. IL-1α positively correlated with elevated bronchoalveolar lavage IL-8 levels (r(2)  = 0.6095, p < 0.0001) and neutrophil percentage (r(2)  = 0.25, p = 0.01). Conditioned media from P. aeruginosa infected epithelial cells induced a potent pro-inflammatory phenotype in fibroblasts via an IL-1α/IL-1R-dependent signaling pathway. In conclusion, we propose that IL-1α may be a novel therapeutic target to limit Pseudomonas associated allograft injury after lung transplantation. PMID:26714197

  8. Direct effects of interleukin-13 on epithelial cells cause airway hyperreactivity and mucus overproduction in asthma.

    PubMed

    Kuperman, Douglas A; Huang, Xiaozhu; Koth, Laura L; Chang, Grace H; Dolganov, Gregory M; Zhu, Zhou; Elias, Jack A; Sheppard, Dean; Erle, David J

    2002-08-01

    Asthma is an increasingly common disease that remains poorly understood and difficult to manage. This disease is characterized by airway hyperreactivity (AHR, defined by exaggerated airflow obstruction in response to bronchoconstrictors), mucus overproduction and chronic eosinophilic inflammation. AHR and mucus overproduction are consistently linked to asthma symptoms and morbidity. Asthma is mediated by Th2 lymphocytes, which produce a limited repertoire of cytokines, including interleukin-4 (IL-4), IL-5, IL-9 and IL-13. Although each of these cytokines has been implicated in asthma, IL-13 is now thought to be especially critical. In animal models of allergic asthma, blockade of IL-13 markedly inhibits allergen-induced AHR, mucus production and eosinophilia. Furthermore, IL-13 delivery to the airway causes all of these effects. IL-13 is thus both necessary and sufficient for experimental models of asthma. However, the IL-13-responsive cells causing these effects have not been identified. Here we show that mice lacking signal transducer and activator of transcription 6 (STAT6) were protected from all pulmonary effects of IL-13. Reconstitution of STAT6 only in epithelial cells was sufficient for IL-13-induced AHR and mucus production in the absence of inflammation, fibrosis or other lung pathology. These results demonstrate the importance of direct effects of IL-13 on epithelial cells in causing two central features of asthma. PMID:12091879

  9. An investigation of the influence of cell topography on epithelial mechanical stresses during pulmonary airway reopening

    PubMed Central

    Jacob, A. M.; Gaver, D. P.

    2013-01-01

    The goal of this study is to assess the local mechanical environment of the pulmonary epithelium in a computational model of airway reopening. To this end, the boundary element method (BEM) in conjunction with lubrication theory is implemented to assess the stationary-state behavior of a semi-infinite bubble traveling through a liquid-occluded parallel plate flow chamber lined with epithelial cells. The fluid occlusion is assumed to be Newtonian and inertia is neglected. The interactions between the microgeometry of the model airway’s walls and the interfacial kinematics surrounding the bubble’s tip result in a complex, spatially and temporally dependent stress distribution. The walls’ nonplanar topography magnifies the normal and shear stresses and stress gradients. We find that decreasing the bubble’s speed serves to increase the maximum normal stress and stress gradient but decrease the maximum shear stress and stress gradient. Our results give credence to the pressure-gradient-induced epithelial damage theory recently proposed by Bilek et al. [J. Appl. Physiol. 94, 770 (2003)] and Kay et al. [J. Appl. Physiol. 97, 269 (2004)]. We conclude that the amplified pressure gradients found in this study may be even more detrimental to the airway’s cellular epithelium during airway reopening. PMID:23745044

  10. Pseudomonas pyocyanin increases interleukin-8 expression by human airway epithelial cells.

    PubMed

    Denning, G M; Wollenweber, L A; Railsback, M A; Cox, C D; Stoll, L L; Britigan, B E

    1998-12-01

    Pseudomonas aeruginosa, an opportunistic human pathogen, causes acute pneumonia in patients with hospital-acquired infections and is commonly associated with chronic lung disease in individuals with cystic fibrosis (CF). Evidence suggests that the pathophysiological effects of P. aeruginosa are mediated in part by virulence factors secreted by the bacterium. Among these factors is pyocyanin, a redox active compound that increases intracellular oxidant stress. We find that pyocyanin increases release of interleukin-8 (IL-8) by both normal and CF airway epithelial cell lines and by primary airway epithelial cells. Moreover, pyocyanin synergizes with the inflammatory cytokines tumor necrosis factor alpha and IL-1alpha. RNase protection assays indicate that increased IL-8 release is accompanied by increased levels of IL-8 mRNA. The antioxidant n-acetyl cysteine, general inhibitors of protein tyrosine kinases, and specific inhibitors of mitogen-activated protein kinases diminish pyocyanin-dependent increases in IL-8 release. Conversely, inhibitors of protein kinases C (PKC) and PKA have no effect. In contrast to its effects on IL-8 expression, pyocyanin inhibits cytokine-dependent expression of the monocyte/macrophage/T-cell chemokine RANTES. Increased release of IL-8, a potent neutrophil chemoattractant, in response to pyocyanin could contribute to the marked infiltration of neutrophils and subsequent neutrophil-mediated tissue damage that are observed in Pseudomonas-associated lung disease. PMID:9826354

  11. Pseudomonas Pyocyanin Increases Interleukin-8 Expression by Human Airway Epithelial Cells

    PubMed Central

    Denning, Gerene M.; Wollenweber, Laura A.; Railsback, Michelle A.; Cox, Charles D.; Stoll, Lynn L.; Britigan, Bradley E.

    1998-01-01

    Pseudomonas aeruginosa, an opportunistic human pathogen, causes acute pneumonia in patients with hospital-acquired infections and is commonly associated with chronic lung disease in individuals with cystic fibrosis (CF). Evidence suggests that the pathophysiological effects of P. aeruginosa are mediated in part by virulence factors secreted by the bacterium. Among these factors is pyocyanin, a redox active compound that increases intracellular oxidant stress. We find that pyocyanin increases release of interleukin-8 (IL-8) by both normal and CF airway epithelial cell lines and by primary airway epithelial cells. Moreover, pyocyanin synergizes with the inflammatory cytokines tumor necrosis factor alpha and IL-1α. RNase protection assays indicate that increased IL-8 release is accompanied by increased levels of IL-8 mRNA. The antioxidant n-acetyl cysteine, general inhibitors of protein tyrosine kinases, and specific inhibitors of mitogen-activated protein kinases diminish pyocyanin-dependent increases in IL-8 release. Conversely, inhibitors of protein kinases C (PKC) and PKA have no effect. In contrast to its effects on IL-8 expression, pyocyanin inhibits cytokine-dependent expression of the monocyte/macrophage/T-cell chemokine RANTES. Increased release of IL-8, a potent neutrophil chemoattractant, in response to pyocyanin could contribute to the marked infiltration of neutrophils and subsequent neutrophil-mediated tissue damage that are observed in Pseudomonas-associated lung disease. PMID:9826354

  12. Allergens stimulate store-operated calcium entry and cytokine production in airway epithelial cells

    PubMed Central

    Jairaman, Amit; Maguire, Chelsea H.; Schleimer, Robert P.; Prakriya, Murali

    2016-01-01

    Aberrant immune responses to environmental allergens including insect allergens from house dust mites and cockroaches contribute to allergic inflammatory diseases such as asthma in susceptible individuals. Airway epithelial cells (AECs) play a critical role in this process by sensing the proteolytic activity of allergens via protease-activated receptors (PAR2) to initiate inflammatory and immune responses in the airway. Elevation of cytosolic Ca2+ is an important signaling event in this process, yet the fundamental mechanism by which allergens induce Ca2+ elevations in AECs remains poorly understood. Here we find that extracts from dust mite and cockroach induce sustained Ca2+ elevations in AECs through the activation of Ca2+ release-activated Ca2+ (CRAC) channels encoded by Orai1 and STIM1. CRAC channel activation occurs, at least in part, through allergen mediated stimulation of PAR2 receptors. The ensuing Ca2+ entry then activates NFAT/calcineurin signaling to induce transcriptional production of the proinflammatory cytokines IL-6 and IL-8. These findings highlight a key role for CRAC channels as regulators of allergen induced inflammatory responses in the airway. PMID:27604412

  13. Allergens stimulate store-operated calcium entry and cytokine production in airway epithelial cells.

    PubMed

    Jairaman, Amit; Maguire, Chelsea H; Schleimer, Robert P; Prakriya, Murali

    2016-01-01

    Aberrant immune responses to environmental allergens including insect allergens from house dust mites and cockroaches contribute to allergic inflammatory diseases such as asthma in susceptible individuals. Airway epithelial cells (AECs) play a critical role in this process by sensing the proteolytic activity of allergens via protease-activated receptors (PAR2) to initiate inflammatory and immune responses in the airway. Elevation of cytosolic Ca(2+) is an important signaling event in this process, yet the fundamental mechanism by which allergens induce Ca(2+) elevations in AECs remains poorly understood. Here we find that extracts from dust mite and cockroach induce sustained Ca(2+) elevations in AECs through the activation of Ca(2+) release-activated Ca(2+) (CRAC) channels encoded by Orai1 and STIM1. CRAC channel activation occurs, at least in part, through allergen mediated stimulation of PAR2 receptors. The ensuing Ca(2+) entry then activates NFAT/calcineurin signaling to induce transcriptional production of the proinflammatory cytokines IL-6 and IL-8. These findings highlight a key role for CRAC channels as regulators of allergen induced inflammatory responses in the airway. PMID:27604412

  14. Airway surface liquid volume expansion induces rapid changes in amiloride-sensitive Na+ transport across upper airway epithelium-Implications concerning the resolution of pulmonary edema

    PubMed Central

    Azizi, Fouad; Arredouani, Abdelilah; Mohammad, Ramzi M

    2015-01-01

    During airway inflammation, airway surface liquid volume (ASLV) expansion may result from the movement of plasma proteins and excess liquid into the airway lumen due to extravasation and elevation of subepithelial hydrostatic pressure. We previously demonstrated that elevation of submucosal hydrostatic pressure increases airway epithelium permeability resulting in ASLV expansion by 500 μL cm−2 h−1. Liquid reabsorption by healthy airway epithelium is regulated by active Na+ transport at a rate of 5 μL cm−2 h−1. Thus, during inflammation the airway epithelium may be submerged by a large volume of luminal liquid. Here, we have investigated the mechanism by which ASLV expansion alters active epithelial Na+ transport, and we have characterized the time course of the change. We used primary cultures of tracheal airway epithelium maintained under air interface (basal ASLV, depth is 7 ± 0.5 μm). To mimic airway flooding, ASLV was expanded to a depth of 5 mm. On switching from basal to expanded ASLV conditions, short-circuit current (Isc, a measure of total transepithelial active ion transport) declined by 90% with a half-time (t1/2) of 1 h. 24 h after the switch, there was no significant change in ATP concentration nor in the number of functional sodium pumps as revealed by [3H]-ouabain binding. However, amiloride-sensitive uptake of 22Na+ was reduced by 70% upon ASLV expansion. This process is reversible since after returning cells back to air interface, Isc recovered with a t1/2 of 5–10 h. These results may have important clinical implications concerning the development of Na+ channels activators and resolution of pulmonary edema. PMID:26333829

  15. Pseudomonas aeruginosa pyocyanin modulates mucin glycosylation with sialyl-Lewis(x) to increase binding to airway epithelial cells.

    PubMed

    Jeffries, J L; Jia, J; Choi, W; Choe, S; Miao, J; Xu, Y; Powell, R; Lin, J; Kuang, Z; Gaskins, H R; Lau, G W

    2016-07-01

    Cystic fibrosis (CF) patients battle life-long pulmonary infections with the respiratory pathogen Pseudomonas aeruginosa (PA). An overabundance of mucus in CF airways provides a favorable niche for PA growth. When compared with that of non-CF individuals, mucus of CF airways is enriched in sialyl-Lewis(x), a preferred binding receptor for PA. Notably, the levels of sialyl-Lewis(x) directly correlate with infection severity in CF patients. However, the mechanism by which PA causes increased sialylation remains uncharacterized. In this study, we examined the ability of PA virulence factors to modulate sialyl-Lewis(x) modification in airway mucins. We found pyocyanin (PCN) to be a potent inducer of sialyl-Lewis(x) in both mouse airways and in primary and immortalized CF and non-CF human airway epithelial cells. PCN increased the expression of C2/4GnT and ST3Gal-IV, two of the glycosyltransferases responsible for the stepwise biosynthesis of sialyl-Lewis(x), through a tumor necrosis factor (TNF)-α-mediated phosphoinositol-specific phospholipase C (PI-PLC)-dependent pathway. Furthermore, PA bound more efficiently to airway epithelial cells pre-exposed to PCN in a flagellar cap-dependent manner. Importantly, antibodies against sialyl-Lewis(x) and anti-TNF-α attenuated PA binding. These results indicate that PA secretes PCN to induce a favorable environment for chronic colonization of CF lungs by increasing the glycosylation of airway mucins with sialyl-Lewis(x). PMID:26555707

  16. Pseudomonas aeruginosa pyocyanin modulates mucin glycosylation with sialyl-Lewisx to increase binding to airway epithelial cells

    PubMed Central

    Choi, Woosuk; Choe, Shawn; Miao, Jinfeng; Xu, Ying; Powell, Rebecca; Lin, Jingjun; Kuang, Zhizhou; Gaskins, H Rex; Lau, Gee W.

    2015-01-01

    Cystic fibrosis (CF) patients battle life-long pulmonary infections with the respiratory pathogen Pseudomonas aeruginosa (PA). An overabundance of mucus in CF airways provides a favorable niche for PA growth. When compared to that of non-CF individuals, mucus of CF airways is enriched in sialyl-Lewisx, a preferred binding receptor for PA. Notably, the levels of sialyl-Lewisx directly correlate with infection severity in CF patients. However, the mechanism by which PA causes increased sialylation remains uncharacterized. In this study, we examined the ability of PA virulence factors to modulate sialyl-Lewisx modification in airway mucins. We found pyocyanin (PCN) to be a potent inducer of sialyl-Lewisx in both mouse airways and in primary and immortalized CF and non-CF human airway epithelial cells. PCN increased the expression of C2/4GnT and ST3Gal-IV, two of the glycosyltransferases responsible for the stepwise biosynthesis of sialyl-Lewisx, through a TNF-α-mediated phosphoinositol-specific phospholipase C (PI-PLC) dependent pathway. Furthermore, PA bound more efficiently to airway epithelial cells pre-exposed to PCN through a flagellar cap-dependent manner. Importantly, antibodies against sialyl-Lewisx and anti-TNF-α attenuated PA binding. These results indicate that PCN secretes PCN to induce a favorable environment for chronic colonization of CF lungs by increasing the glycosylation of airway mucins with sialyl-Lewisx. PMID:26555707

  17. Junctional abnormalities in human airway epithelial cells expressing F508del CFTR

    PubMed Central

    Stauffer, Brandon; Moriarty, Hannah K.; Kim, Agnes H.; McCarty, Nael A.; Koval, Michael

    2015-01-01

    Cystic fibrosis (CF) has a profound impact on airway physiology. Accumulating evidence suggests that intercellular junctions are impaired in CF. We examined changes to CF transmembrane conductance regulator (CFTR) function, tight junctions, and gap junctions in NuLi-1 (CFTRwt/wt) and CuFi-5 (CFTRΔF508/ΔF508) cells. Cells were studied at air-liquid interface (ALI) and compared with primary human bronchial epithelial cells. On the basis of fluorescent lectin binding, the phenotype of the NuLi-1 and CuFi-5 cells at week 8 resembled that of serous, glycoprotein-rich airway cells. After week 7, CuFi-5 cells possessed 130% of the epithelial Na+ channel activity and 17% of the CFTR activity of NuLi-1 cells. In both cell types, expression levels of CFTR were comparable to those in primary airway epithelia. Transepithelial resistance of NuLi-1 and CuFi-5 cells stabilized during maturation in ALI culture, with significantly lower transepithelial resistance for CuFi-5 than NuLi-1 cells. We also found that F508del CFTR negatively affects gap junction function in the airway. NuLi-1 and CuFi-5 cells express the connexins Cx43 and Cx26. While both connexins were properly trafficked by NuLi-1 cells, Cx43 was mistrafficked by CuFi-5 cells. Cx43 trafficking was rescued in CuFi-5 cells treated with 4-phenylbutyric acid (4-PBA), as assessed by intracellular dye transfer. 4-PBA-treated CuFi-5 cells also exhibited an increase in forskolin-induced CFTR-mediated currents. The Cx43 trafficking defect was confirmed using IB3-1 cells and found to be corrected by 4-PBA treatment. These data support the use of NuLi-1 and CuFi-5 cells to examine the effects of F508del CFTR expression on tight junction and gap junction function in the context of serous human airway cells. PMID:26115671

  18. Junctional abnormalities in human airway epithelial cells expressing F508del CFTR.

    PubMed

    Molina, Samuel A; Stauffer, Brandon; Moriarty, Hannah K; Kim, Agnes H; McCarty, Nael A; Koval, Michael

    2015-09-01

    Cystic fibrosis (CF) has a profound impact on airway physiology. Accumulating evidence suggests that intercellular junctions are impaired in CF. We examined changes to CF transmembrane conductance regulator (CFTR) function, tight junctions, and gap junctions in NuLi-1 (CFTR(wt/wt)) and CuFi-5 (CFTR(ΔF508/ΔF508)) cells. Cells were studied at air-liquid interface (ALI) and compared with primary human bronchial epithelial cells. On the basis of fluorescent lectin binding, the phenotype of the NuLi-1 and CuFi-5 cells at week 8 resembled that of serous, glycoprotein-rich airway cells. After week 7, CuFi-5 cells possessed 130% of the epithelial Na(+) channel activity and 17% of the CFTR activity of NuLi-1 cells. In both cell types, expression levels of CFTR were comparable to those in primary airway epithelia. Transepithelial resistance of NuLi-1 and CuFi-5 cells stabilized during maturation in ALI culture, with significantly lower transepithelial resistance for CuFi-5 than NuLi-1 cells. We also found that F508del CFTR negatively affects gap junction function in the airway. NuLi-1 and CuFi-5 cells express the connexins Cx43 and Cx26. While both connexins were properly trafficked by NuLi-1 cells, Cx43 was mistrafficked by CuFi-5 cells. Cx43 trafficking was rescued in CuFi-5 cells treated with 4-phenylbutyric acid (4-PBA), as assessed by intracellular dye transfer. 4-PBA-treated CuFi-5 cells also exhibited an increase in forskolin-induced CFTR-mediated currents. The Cx43 trafficking defect was confirmed using IB3-1 cells and found to be corrected by 4-PBA treatment. These data support the use of NuLi-1 and CuFi-5 cells to examine the effects of F508del CFTR expression on tight junction and gap junction function in the context of serous human airway cells. PMID:26115671

  19. Yap Tunes Airway Epithelial Size and Architecture by Regulating the Identity, Maintenance, and Self-renewal of Stem Cells

    PubMed Central

    Zhao, Rui; Fallon, Timothy R.; Saladi, Srinivas Vinod; Pardo-Saganta, Ana; Villoria, Jorge; Mou, Hongmei; Vinarsky, Vladimir; Gonzalez-Celeiro, Meryem; Nunna, Naveen; Hariri, Lida P.; Camargo, Fernando; Ellisen, Leif W.; Rajagopal, Jayaraj

    2014-01-01

    SUMMARY Our understanding of how stem cells are regulated to maintain appropriate tissue size and architecture is incomplete. We show that Yap is required for the actual maintenance of an adult mammalian stem cell. Without Yap, adult airway basal stem cells are lost through their unrestrained differentiation, resulting in the simplification of a pseudostratified epithelium into a columnar one. Conversely, Yap overexpression increases stem cell self-renewal and blocks terminal differentiation, resulting in epithelial hyperplasia and stratification. Yap overexpression in differentiated secretory cells causes them to partially reprogram and adopt a stem cell-like identity. In contrast, Yap knockdown prevents the dedifferentiation of secretory cells into stem cells. We then show that Yap functionally interacts with p63, the cardinal transcription factor associated with myriad epithelial basal stem cells. In aggregate, we show that Yap regulates all of the cardinal behaviors of airway epithelial stem cells and in so doing determines epithelial architecture. PMID:25043474

  20. Effect of C-fiber-mediated, ozone-induced rapid shallow breathing on airway epithelial injury in rats.

    PubMed

    Schelegle, E S; Alfaro, M F; Putney, L; Stovall, M; Tyler, N; Hyde, D M

    2001-10-01

    We examined the relationship between C-fiber-mediated, ozone-induced rapid shallow breathing and airway epithelial cell injury at different airway sites within the lower respiratory tract of conscious Wistar rats (n = 24). We combined an acute 8-h ozone inhalation with vagal perineural capsaicin treatment, a selective C-fiber conduction block, and 5-bromo-2'-deoxyuridine (BrdU) labeling as an index of epithelial injury. Vehicle-treated rats that inhaled ozone developed a rapid shallow breathing pattern during ozone inhalation, whereas the capsaicin-treated rats that inhaled ozone showed no changes in respiratory frequency. In vehicle-treated, ozone-exposed rats that developed rapid shallow breathing, a progressive increase in BrdU-labeling density (no. of BrdU-labeled cells/mm(2) airway) was observed starting at the bifurcation of the left main stem bronchi (central airway) and going down either a short or long airway path. In vehicle-treated, ozone-exposed rats, terminal bronchioles supplied by short and long airway paths had a similar degree of BrdU-labeling density that was significantly (P < 0.05) greater than the BrdU-labeling density of the proximal airways that supply them. In contrast, the attenuation of rapid shallow breathing produced by capsaicin treatment resulted in a significantly reduced BrdU-labeling density in the terminal bronchioles supplied by short airway paths compared with the terminal bronchioles supplied by long airway paths. Our data indicate that ozone-induced rapid shallow breathing protects large conducting airways while producing a more even distribution of injury to terminal bronchioles. PMID:11568142

  1. Kaempferol Inhibits Endoplasmic Reticulum Stress-Associated Mucus Hypersecretion in Airway Epithelial Cells And Ovalbumin-Sensitized Mice

    PubMed Central

    Choi, Yean-Jung; Kang, Min-Kyung; Kim, Yun-Ho; Kang, Young-Hee

    2015-01-01

    Mucus hypersecretion is an important pathological feature of chronic airway diseases, such as asthma and pulmonary diseases. MUC5AC is a major component of the mucus matrix forming family of mucins in the airways. The initiation of endoplasmic reticulum (ER)-mediated stress responses contributes to the pathogenesis of airway diseases. The present study investigated that ER stress was responsible for airway mucus production and this effect was blocked by the flavonoid kaempferol. Oral administration of ≥10 mg/kg kaempferol suppressed mucus secretion and goblet cell hyperplasia observed in the bronchial airway and lung of BALB/c mice sensitized with ovalbumin (OVA). TGF-β and tunicamycin promoted MUC5AC induction after 72 h in human bronchial airway epithelial BEAS-2B cells, which was dampened by 20 μM kaempferol. Kaempferol inhibited tunicamycin-induced ER stress of airway epithelial cells through disturbing the activation of the ER transmembrane sensor ATF6 and IRE1α. Additionally, this compound demoted the induction of ER chaperones such as GRP78 and HSP70 and the splicing of XBP-1 mRNA by tunicamycin. The in vivo study further revealed that kaempferol attenuated the induction of XBP-1 and IRE1α in epithelial tissues of OVA-challenged mice. TGF-β and tunicamycin induced TRAF2 with JNK activation and such induction was deterred by kaempferol. The inhibition of JNK activation encumbered the XBP-1 mRNA splicing and MUC5AC induction by tunicamycin and TGF-β. These results demonstrate that kaempferol alleviated asthmatic mucus hypersecretion through blocking bronchial epithelial ER stress via the inhibition of IRE1α-TRAF2-JNK activation. Therefore, kaempferol may be a potential therapeutic agent targeting mucus hypersecretion-associated pulmonary diseases. PMID:26599511

  2. The Role of Lysophosphatidic Acid on Airway Epithelial Cell Denudation in a Murine Heterotopic Tracheal Transplant Model

    PubMed Central

    Tando, Yukiko; Ota, Chiharu; Yamada, Mitsuhiro; Kamata, Satoshi; Yamaya, Mutsuo; Kano, Kuniyuki; Okudaira, Shinichi; Aoki, Junken; Kubo, Hiroshi

    2015-01-01

    Background Chronic rejection is the major leading cause of morbidity and mortality after lung transplantation. Obliterative bronchiolitis (OB), a fibroproliferative disorder of the small airways, is the main manifestation of chronic lung allograft rejection. However, there is currently no treatment for the disease. We hypothesized that lysophosphatidic acid (LPA) participates in the progression of OB. The aim of this study was to reveal the involvement of LPA on the lesion of OB. Methods Ki16198, an antagonist specifically for LPA1 and LPA3, was daily administered into the heterotopic tracheal transplant model mice at the day of transplantation. At days 10 and 28, the allografts were isolated and evaluated histologically. The messenger RNA levels of LPAR in microdissected mouse airway regions were assessed to reveal localization of lysophosphatidic acid receptors. The human airway epithelial cell was used to evaluate the mechanism of LPA-induced suppression of cell adhesion to the extracellular matrix (ECM). Results The administration of Ki16198 attenuated airway epithelial cell loss in the allograft at day 10. Messenger RNAs of LPA1 and LPA3 were detected in the airway epithelial cells of the mice. Lysophosphatidic acid inhibited the attachment of human airway epithelial cells to the ECM and induced cell detachment from the ECM, which was mediated by LPA1 and Rho-kinase pathway. However, Ki16198 did not prevent obliteration of allograft at day 28. Conclusions The LPA signaling is involved in the status of epithelial cells by distinct contribution in 2 different phases of the OB lesion. This finding suggests a role of LPA in the pathogenesis of OB. PMID:27500235

  3. Oxidative Stress Regulates CFTR Gene Expression in Human Airway Epithelial Cells through a Distal Antioxidant Response Element

    PubMed Central

    Zhang, Zhaolin; Leir, Shih-Hsing

    2015-01-01

    Cystic fibrosis transmembrane conductance regulator gene (CFTR) expression in human airway epithelial cells involves the recruitment of distal cis-regulatory elements, which are associated with airway-selective DNase hypersensitive sites at −44 kb and −35 kb from the gene. The −35-kb site encompasses an enhancer that is regulated by the immune mediators interferon regulatory factor 1 and 2 and by nuclear factor Y. Here we investigate the −44-kb element, which also has enhancer activity in vitro in airway epithelial cells but is inactive in intestinal epithelial cells. This site contains an antioxidant response element (ARE) that plays a critical role in its function in airway cell lines and primary human bronchial epithelial cells. The natural antioxidant sulforaphane (SFN) induces nuclear translocation of nuclear factor, erythroid 2-like 2 (Nrf2), a transcription factor that regulates genes with AREs in their promoters, many of which are involved in response to injury. Under normal conditions, the −44-kb ARE is occupied by the repressor BTB and CNC homology 1, basic leucine zipper transcription factor (Bach1), and v-Maf avian musculoaponeurotic fibrosarcoma oncogene homolog K (MafK) heterodimers. After 2 hours of SFN treatment, Nrf2 displaces these repressive factors and activates CFTR expression. Site-directed mutagenesis shows that both the ARE and an adjacent NF-κB binding site are required for activation of the –44-kb element in airway epithelial cells. Moreover, this element is functionally linked to the −35-kb enhancer in modulating CFTR expression in response to environmental stresses in the airway. PMID:25259561

  4. α1-Antitrypsin reduces rhinovirus infection in primary human airway epithelial cells exposed to cigarette smoke

    PubMed Central

    Berman, Reena; Jiang, Di; Wu, Qun; Chu, Hong Wei

    2016-01-01

    Human rhinovirus (HRV) infections target airway epithelium and are the leading cause of acute exacerbations of COPD. Cigarette smoke (CS) increases the severity of viral infections, but there is no effective therapy for HRV infection. We determined whether α1-antitrypsin (A1AT) reduces HRV-16 infection in CS-exposed primary human airway epithelial cells. Brushed bronchial epithelial cells from normal subjects and patients diagnosed with COPD were cultured at air–liquid interface to induce mucociliary differentiation. These cells were treated with A1AT or bovine serum albumin for 2 hours and then exposed to air or whole cigarette smoke (WCS) with or without HRV-16 (5×104 50% Tissue Culture Infective Dose [TCID50]/transwell) infection for 24 hours. WCS exposure significantly increased viral load by an average of fivefold and decreased the expression of antiviral genes interferon-λ1, OAS1, and MX1. When A1AT was added to WCS-exposed cells, viral load significantly decreased by an average of 29-fold. HRV-16 infection significantly increased HRV-16 receptor intercellular adhesion molecule-1 messenger RNA expression in air-exposed cells, which was decreased by A1AT. A1AT-mediated reduction of viral load was not accompanied by increased epithelial antiviral gene expression or by inhibiting the activity of 3C protease involved in viral replication or maturation. Our findings demonstrate that A1AT treatment prevents a WCS-induced increase in viral load and for the first time suggest a therapeutic effect of A1AT on HRV infection. PMID:27354786

  5. Arsenic alters ATP-dependent Ca²+ signaling in human airway epithelial cell wound response.

    PubMed

    Sherwood, Cara L; Lantz, R Clark; Burgess, Jefferey L; Boitano, Scott

    2011-05-01

    Arsenic is a natural metalloid toxicant that is associated with occupational inhalation injury and contaminates drinking water worldwide. Both inhalation of arsenic and consumption of arsenic-tainted water are correlated with malignant and nonmalignant lung diseases. Despite strong links between arsenic and respiratory illness, underlying cell responses to arsenic remain unclear. We hypothesized that arsenic may elicit some of its detrimental effects on the airway through limitation of innate immune function and, specifically, through alteration of paracrine ATP (purinergic) Ca²+ signaling in the airway epithelium. We examined the effects of acute (24 h) exposure with environmentally relevant levels of arsenic (i.e., < 4 μM as Na-arsenite) on wound-induced Ca²+ signaling pathways in human bronchial epithelial cell line (16HBE14o-). We found that arsenic reduces purinergic Ca²+ signaling in a dose-dependent manner and results in a reshaping of the Ca²+ signaling response to localized wounds. We next examined arsenic effects on two purinergic receptor types: the metabotropic P2Y and ionotropic P2X receptors. Arsenic inhibited both P2Y- and P2X-mediated Ca²+ signaling responses to ATP. Both inhaled and ingested arsenic can rapidly reach the airway epithelium where purinergic signaling is essential in innate immune functions (e.g., ciliary beat, salt and water transport, bactericide production, and wound repair). Arsenic-induced compromise of such airway defense mechanisms may be an underlying contributor to chronic lung disease. PMID:21357385

  6. The effect of ambroxol on chloride transport, CFTR and ENaC in cystic fibrosis airway epithelial cells.

    PubMed

    Varelogianni, Georgia; Hussain, Rashida; Strid, Hilja; Oliynyk, Igor; Roomans, Godfried M; Johannesson, Marie

    2013-11-01

    Ambroxol, a mucokinetic anti-inflammatory drug, has been used for treatment of cystic fibrosis (CF). The respiratory epithelium is covered by the airway surface liquid (ASL), the thickness and composition of which is determined by Cl(-) efflux via the cystic fibrosis transmembrane conductance regulator (CFTR) and Na(+) influx via the epithelial Na(+) channel (ENaC). In cells expressing wt-CFTR, ambroxol increased the Cl(-) conductance, but not the bicarbonate conductance of the CFTR channels. We investigated whether treatment with ambroxol enhances chloride transport and/or CFTR and ENaC expression in CF airway epithelial cells (CFBE) cells. CFBE cells were treated with 100 µM ambroxol for 2, 4 or 8 h. mRNA expression for CFTR and ENaC subunits was analysed by real-time polymerase chain reaction (RT-PCR); protein expression was measured by Western blot. The effect of ambroxol on Cl(-) transport was measured by Cl(-) efflux measurements with a fluorescent chloride probe. Ambroxol significantly stimulated Cl(-) efflux from CFBE cells (a sixfold increase after 8 h treatment), and enhanced the expression of the mRNA of CFTR and α-ENaC, and of the CFTR protein. No significant difference was observed in β-ENaC after exposure to ambroxol, whereas mRNA expression of γ-ENaC was reduced. No significant effects of ambroxol on the ENaC subunits were observed by Western blot. Ambroxol did not significantly affect the intracellular Ca(2+) concentration. Upregulation of CFTR and enhanced Cl(-) efflux after ambroxol treatment should promote transepithelial ion and water transport, which may improve hydration of the mucus, and therefore be beneficial to CF-patients. PMID:23765701

  7. Interleukin-13 interferes with CFTR and AQP5 expression and localization during human airway epithelial cell differentiation

    SciTech Connect

    Skowron-zwarg, Marie; Boland, Sonja; Caruso, Nathalie; Coraux, Christelle; Marano, Francelyne; Tournier, Frederic . E-mail: f-tournier@paris7.jussieu.fr

    2007-07-15

    Interleukin-13 (IL-13) is a central regulator of Th2-dominated respiratory disorders such as asthma. Lesions of the airway epithelial barrier frequently observed in chronic respiratory inflammatory diseases are repaired through proliferation, migration and differentiation of epithelial cells. Our work is focused on the effects of IL-13 in human cellular models of airway epithelial cell regeneration. We have previously shown that IL-13 altered epithelial cell polarity during mucociliary differentiation of human nasal epithelial cells. In particular, the cytokine inhibited ezrin expression and interfered with its apical localization during epithelial cell differentiation in vitro. Here we show that CFTR expression is enhanced in the presence of the cytokine, that two additional CFTR protein isoforms are expressed in IL-13-treated cells and that part of the protein is retained within the endoplasmic reticulum. We further show that aquaporin 5 expression, a water channel localized within the apical membrane of epithelial cells, is completely abolished in the presence of the cytokine. These results show that IL-13 interferes with ion and water channel expression and localization during epithelial regeneration and may thereby influence mucus composition and hydration.

  8. IL-13 Augments Compressive Stress-Induced Tissue Factor Expression in Human Airway Epithelial Cells.

    PubMed

    Mitchel, Jennifer A; Antoniak, Silvio; Lee, Joo-Hyeon; Kim, Sae-Hoon; McGill, Maureen; Kasahara, David I; Randell, Scott H; Israel, Elliot; Shore, Stephanie A; Mackman, Nigel; Park, Jin-Ah

    2016-04-01

    Tissue factor (TF) is best known as a cellular initiator of coagulation, but it is also a multifunctional protein that has been implicated in multiple pathophysiologic conditions, including asthma. In the lung, airway epithelial cells express TF, but it is unknown how TF expression is regulated by asthma-associated mediators. We investigated the role of IL-13, a type 2 cytokine, alone and in combination with compressive stress, which mimics asthmatic bronchoconstriction, on TF expression and release of TF-positive extracellular vesicles from primary normal human bronchial epithelial cells. Well-differentiated normal human bronchial epithelial cells were treated with IL-13 and compressive stress, alone and in combination. TF mRNA, protein and activity were measured in the cells and conditioned media. TF was also measured in the bronchoalveolar lavage (BAL) fluid of allergen-challenged mice and patients with asthma. IL-13 and compressive stress increased TF expression, but only compressive stress induced TF-positive extracellular vesicle release. Pretreatment with IL-13 augmented compressive stress-induced TF expression and release. TF protein and activity in BAL fluid were increased in allergen-sensitized and -challenged mice. TF was elevated in the BAL fluid of patients with mild asthma after an allergen challenge. Our in vitro and in vivo data indicate close cooperation between mechanical and inflammatory stimuli on TF expression and release of TF-positive extracellular vesicles in the lungs, which may contribute to pathophysiology of asthma. PMID:26407210

  9. Airway Epithelial Orchestration of Innate Immune Function in Response to Virus Infection. A Focus on Asthma.

    PubMed

    Ritchie, Andrew I; Jackson, David J; Edwards, Michael R; Johnston, Sebastian L

    2016-03-01

    Asthma is a very common respiratory condition with a worldwide prevalence predicted to increase. There are significant differences in airway epithelial responses in asthma that are of particular interest during exacerbations. Preventing exacerbations is a primary aim when treating asthma because they often necessitate unscheduled healthcare visits and hospitalizations and are a significant cause of morbidity and mortality. The most common cause of asthma exacerbations is a respiratory virus infection, of which the most likely type is rhinovirus infection. This article focuses on the role played by the epithelium in orchestrating the innate immune responses to respiratory virus infection. Recent studies show impaired bronchial epithelial cell innate antiviral immune responses, as well as augmentation of a pro-Th2 response characterized by the epithelial-derived cytokines IL-25 and IL-33, crucial in maintaining the Th2 cytokine response to virus infection in asthma. A better understanding of the mechanisms of these abnormal immune responses has the potential to lead to the development of novel therapeutic targets for virus-induced exacerbations. The aim of this article is to highlight current knowledge regarding the role of viruses and immune modulation in the asthmatic epithelium and to discuss exciting areas for future research and novel treatments. PMID:27027954

  10. Lipidome and Transcriptome Profiling of Pneumolysin Intoxication Identifies Networks Involved in Statin-Conferred Protection of Airway Epithelial Cells

    PubMed Central

    Statt, Sarah; Ruan, Jhen-Wei; Huang, Chih-Ting; Wu, Reen; Kao, Cheng-Yuan

    2015-01-01

    Pneumonia remains one of the leading causes of death in both adults and children worldwide. Despite the adoption of a wide variety of therapeutics, the mortality from community-acquired pneumonia has remained relatively constant. Although viral and fungal acute airway infections can result in pneumonia, bacteria are the most common cause of community-acquired pneumonia, with Streptococcus pneumoniae isolated in nearly 50% of cases. Pneumolysin is a cholesterol-dependent cytolysin or pore-forming toxin produced by Streptococcus pneumonia and has been shown to play a critical role in bacterial pathogenesis. Airway epithelium is the initial site of many bacterial contacts and its barrier and mucosal immunity functions are central to infectious lung diseases. In our studies, we have shown that the prior exposure to statins confers significant resistance of airway epithelial cells to the cytotoxicity of pneumolysin. We decided to take this study one step further, assessing changes in both the transcriptome and lipidome of human airway epithelial cells exposed to toxin, statin or both. Our current work provides the first global view in human airway epithelial cells of both the transcriptome and the lipid interactions that result in cellular protection from pneumolysin. PMID:26023727

  11. IN VITRO EFFECTS OF PARTICULATE MATTER ON AIRWAY EPITHELIAL CELLS ISOLATED FROM CONCENTRATED AIR PARTICLES-EXPOSED SPONTANEOUS HYPERTENSIVE RATS

    EPA Science Inventory

    In vitro effects of particulate matter on airway epithelial cells isolated from concentrated air particles-exposed spontaneous hypertensive rats

    Ines Pagan, Urmila Kodavanti, Paul Evansky, Daniel L Costa and Janice A Dye. U.S. Environmental Protection Agency, ORD, National...

  12. ULTRAFINE CARBON PARTICLES INDUCE IL-8 EXPRESSION IN HUMAN AIRWAY EPITHELIAL CELLS THROUGH A POST-TRANSCRIPTIONAL MECHANISM

    EPA Science Inventory

    Ultrafine carbon particles induce IL-8 expression in human airway
    epithelial cells through a post-transcritpional mechanism
    Epidemiological studies suggest that ultrafine particles contribute to
    particulate matter (PM) - induced adverse health effects. IL-8 is an
    i...

  13. ZN2+-INDUCED IL-8 EXPRESSION INVOLVES AP-1, JNK, AND ERK ACTIVITIES IN HUMAN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Exposure to zinc-laden particulate matter (PM) in ambient and occupational settings has been associated with proinflammatory responses in the lung. IL-8 is an important proinflammatory cytokine in the human lung and is induced in human airway epithelial cells exposed to zin...

  14. INCREASED IL-8 AND IL-6 EXPRESSION IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO CARBON ULTRAFINE PARTICLES

    EPA Science Inventory

    INCREASED IL-6 AND IL-8 EXPRESSION IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO CARBON ULTRAFINE PARTICLES.
    R Silbajoris1, A G Lenz2, I Jaspers3, J M Samet1. 1NHEERL, USEPA, RTP, NC, USA; 2GSF-Institute for Inhalation Biology, Neuherberg, Germany; 3 CEMLB, UNC-CH, Chapel Hill, ...

  15. Trichostatin A Inhibits Epithelial Mesenchymal Transition Induced by TGF-β1 in Airway Epithelium

    PubMed Central

    Shin, Jae-Min; Lee, Heung-Man

    2016-01-01

    Background and Objectives Tissue remodeling is believed to cause recalcitrant chronic rhinosinusitis (CRS). Epithelial-mesenchymal transition (EMT) is a novel clinical therapeutic target in many chronic airway diseases related with tissue remodeling. The aim of this study was to investigate the effect of trichostatin A (TSA) on transforming growth factor (TGF)-β1-induced EMT in airway epithelium and nasal tissue. Materials and Methods A549 cells, primary nasal epithelial cells (PNECs), or inferior nasal turbinate organ culture were exposed to TSA prior to stimulation with TGF-β1. Expression levels of E-cadherin, vimentin, fibronectin, α-smooth muscle actin (SMA), histone deacetylase 2 (HDAC2), and HDAC4 were determined by western blotting and/or immunofluorescent staining. Hyperacetylation of histone H2 and H4 by TSA was measured by western blotting. After siHDAC transfection, the effects of HDAC2 and HDAC4 silencing on expression of E-cadherin, vimentin, fibronectin, α-SMA, HDAC2, and HDAC4 in TGF-β1-induced A549 were determined by RT-PCR and/or western blotting. We assessed the change in migration capacity of A549 cells by using cell migration assay and transwell invasion assay. Results TGF-β1 altered mRNA and protein expression levels of EMT markers including E-cadherin, vimentin, fibronectin, α-SMA, slug, and snail in A549 cells. Inhibition and silencing of HDAC2 and HDAC4 by TSA and siRNA enhanced TGF-β1-induced EMT in A549 cells. TSA blocked the effect of TGF-β1 on the migratory ability of A549 cells. In experiments using PNECs and inferior turbinate organ cultures, TSA suppressed expression of EMT markers induced by TGF-β1. Conclusions We showed that EMT is induced by TGF-β1 in airway epithelial cells and nasal tissue via activation of HDAC2 and HDAC4, and that inhibition of HDAC2 and HDAC4 by TSA reduces TGF-β1-induced EMT. This observation indicates that histone deacetylase inhibitors such as TSA could be potential candidates for treatment of

  16. Rhythmic Pressure Waves Induce Mucin5AC Expression via an EGFR-Mediated Signaling Pathway in Human Airway Epithelial Cells

    PubMed Central

    Liu, Chunyi; Li, Qi; Kolosov, Victor P.; Perelman, Juliy M.

    2013-01-01

    Rhythmic pressure waves (RPW), mimicking the mechanical forces generated during normal breathing, play a key role in airway surface liquid (ASL) homeostasis. As a major component of ASL, we speculated that the mucin5AC (MUC5AC) expression must also be regulated by RPW. However, fewer researches have focused on this question. Therefore, our aim was to test the effect and mechanism of RPW on MUC5AC expression in cultured human bronchial epithelial cells. Compared with the relevant controls, the transcriptional level of MUC5AC and the protein expressions of MUC5AC, the phospho-epidermal growth factor receptor (p-EGFR), phospho-extracellular signal-related kinase (p-ERK), and phospho-Akt (p-Akt) were all significantly increased after mechanical stimulation. However, this effect could be significantly attenuated by transfecting with EGFR-siRNA. Similarly, pretreating with the inhibitor of ERK or phosphatidylinositol 3-kinases (PI3K)/Akt separately or jointly also significantly reduced MUC5AC expression. Collectively, these results indicate that RPW modulate MUC5AC expression via the EGFR-PI3K-Akt/ERK-signaling pathway in human bronchial epithelial cells. PMID:23768102

  17. Involvement of Toll-like receptor 2 and epidermal growth factor receptor signaling in epithelial expression of airway remodeling factors.

    PubMed

    Homma, Tetsuya; Kato, Atsushi; Sakashita, Masafumi; Norton, James E; Suh, Lydia A; Carter, Roderick G; Schleimer, Robert P

    2015-04-01

    Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti-TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2-dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti-TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α-dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis. PMID:25180535

  18. Involvement of Toll-Like Receptor 2 and Epidermal Growth Factor Receptor Signaling in Epithelial Expression of Airway Remodeling Factors

    PubMed Central

    Kato, Atsushi; Sakashita, Masafumi; Norton, James E.; Suh, Lydia A.; Carter, Roderick G.; Schleimer, Robert P.

    2015-01-01

    Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti–TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2–dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti–TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α–dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis. PMID:25180535

  19. Abnormal spatial diffusion of Ca2+ in F508del-CFTR airway epithelial cells

    PubMed Central

    Antigny, Fabrice; Norez, Caroline; Cantereau, Anne; Becq, Frédéric; Vandebrouck, Clarisse

    2008-01-01

    Background In airway epithelial cells, calcium mobilization can be elicited by selective autocrine and/or paracrine activation of apical or basolateral membrane heterotrimeric G protein-coupled receptors linked to phospholipase C (PLC) stimulation, which generates inositol 1,4,5-trisphosphate (IP3) and 1,2-diacylglycerol (DAG) and induces Ca2+ release from endoplasmic reticulum (ER) stores. Methods In the present study, we monitored the cytosolic Ca2+ transients using the UV light photolysis technique to uncage caged Ca2+ or caged IP3 into the cytosol of loaded airway epithelial cells of cystic fibrosis (CF) and non-CF origin. We compared in these cells the types of Ca2+ receptors present in the ER, and measured their Ca2+ dependent activity before and after correction of F508del-CFTR abnormal trafficking either by low temperature or by the pharmacological corrector miglustat (N-butyldeoxynojirimycin). Results We showed reduction of the inositol 1,4,5-trisphosphate receptors (IP3R) dependent-Ca2+ response following both correcting treatments compared to uncorrected cells in such a way that Ca2+ responses (CF+treatment vs wild-type cells) were normalized. This normalization of the Ca2+ rate does not affect the activity of Ca2+-dependent chloride channel in miglustat-treated CF cells. Using two inhibitors of IP3R1, we observed a decrease of the implication of IP3R1 in the Ca2+ response in CF corrected cells. We observed a similar Ca2+ mobilization between CF-KM4 cells and CFTR-cDNA transfected CF cells (CF-KM4-reverted). When we restored the F508del-CFTR trafficking in CFTR-reverted cells, the specific IP3R activity was also reduced to a similar level as in non CF cells. At the structural level, the ER morphology of CF cells was highly condensed around the nucleus while in non CF cells or corrected CF cells the ER was extended at the totality of cell. Conclusion These results suggest reversal of the IP3R dysfunction in F508del-CFTR epithelial cells by correction of

  20. Identification of human metapneumovirus-induced gene networks in airway epithelial cells by microarray analysis

    SciTech Connect

    Bao, X.; Sinha, M. |; Liu, T.; Hong, C.; Luxon, B.A. |; Garofalo, R.P. ||; Casola, A. ||

    2008-04-25

    Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections in infants, elderly and immunocompromised patients. Little is known about the response to hMPV infection of airway epithelial cells, which play a pivotal role in initiating and shaping innate and adaptive immune responses. In this study, we analyzed the transcriptional profiles of airway epithelial cells infected with hMPV using high-density oligonucleotide microarrays. Of the 47,400 transcripts and variants represented on the Affimetrix GeneChip Human Genome HG-U133 plus 2 array, 1601 genes were significantly altered following hMPV infection. Altered genes were then assigned to functional categories and mapped to signaling pathways. Many up-regulated genes are involved in the initiation of pro-inflammatory and antiviral immune responses, including chemokines, cytokines, type I interferon and interferon-inducible proteins. Other important functional classes up-regulated by hMPV infection include cellular signaling, gene transcription and apoptosis. Notably, genes associated with antioxidant and membrane transport activity, several metabolic pathways and cell proliferation were down-regulated in response to hMPV infection. Real-time PCR and Western blot assays were used to confirm the expression of genes related to several of these functional groups. The overall result of this study provides novel information on host gene expression upon infection with hMPV and also serves as a foundation for future investigations of genes and pathways involved in the pathogenesis of this important viral infection. Furthermore, it can facilitate a comparative analysis of other paramyxoviral infections to determine the transcriptional changes that are conserved versus the one that are specific to individual pathogens.

  1. Host cell autophagy modulates early stages of adenovirus infections in airway epithelial cells.

    PubMed

    Zeng, Xuehuo; Carlin, Cathleen R

    2013-02-01

    Human adenoviruses typically cause mild infections in the upper or lower respiratory tract, gastrointestinal tract, or ocular epithelium. However, adenoviruses may be life-threatening in patients with impaired immunity and some serotypes cause epidemic outbreaks. Attachment to host cell receptors activates cell signaling and virus uptake by endocytosis. At present, it is unclear how vital cellular homeostatic mechanisms affect these early steps in the adenovirus life cycle. Autophagy is a lysosomal degradation pathway for recycling intracellular components that is upregulated during periods of cell stress. Autophagic cargo is sequestered in double-membrane structures called autophagosomes that fuse with endosomes to form amphisomes which then deliver their content to lysosomes. Autophagy is an important adaptive response in airway epithelial cells targeted by many common adenovirus serotypes. Using two established tissue culture models, we demonstrate here that adaptive autophagy enhances expression of the early region 1 adenovirus protein, induction of mitogen-activated protein kinase signaling, and production of new viral progeny in airway epithelial cells infected with adenovirus type 2. We have also discovered that adenovirus infections are tightly regulated by endosome maturation, a process characterized by abrupt exchange of Rab5 and Rab7 GTPases, associated with early and late endosomes, respectively. Moreover, endosome maturation appears to control a pool of early endosomes capable of fusing with autophagosomes which enhance adenovirus infection. Many viruses have evolved mechanisms to induce autophagy in order to aid their own replication. Our studies reveal a novel role for host cell autophagy that could have a significant impact on the outcome of respiratory infections. PMID:23236070

  2. Tissue-engineered endothelial and epithelial implants differentially and synergistically regulate airway repair.

    PubMed

    Zani, Brett G; Kojima, Koji; Vacanti, Charles A; Edelman, Elazer R

    2008-05-13

    The trilaminate vascular architecture provides biochemical regulation and mechanical integrity. Yet regulatory control can be regained after injury without recapitulating tertiary structure. Tissue-engineered (TE) endothelium controls repair even when placed in the perivascular space of injured vessels. It remains unclear from vascular repair studies whether endothelial implants recapitulate the vascular epithelial lining or expose injured tissues to endothelial cells (ECs) with unique healing potential because ECs line the vascular epithelium and the vasa vasorum. We examined this issue in a nonvascular tubular system, asking whether airway repair is controlled by bronchial epithelial cells (EPs) or by ECs of the perfusing bronchial vasculature. Localized bronchial denuding injury damaged epithelium, narrowed bronchial lumen, and led to mesenchymal cell hyperplasia, hypervascularity, and inflammatory cell infiltration. Peribronchial TE constructs embedded with EPs or ECs limited airway injury, although optimum repair was obtained when both cells were present in TE matrices. EC and EP expression of PGE(2), TGFbeta1, TGFbeta2, GM-CSF, IL-8, MCP-1, and soluble VCAM-1 and ICAM-1 was altered by matrix embedding, but expression was altered most significantly when both cells were present simultaneously. EPs may provide for functional control of organ injury and fibrous response, and ECs may provide for preservation of tissue perfusion and the epithelium in particular. Together the two cells optimize functional restoration and healing, suggesting that multiple cells of a tissue contribute to the differentiated biochemical function and repair of a tissue, but need not assume a fixed, ordered architectural relationship, as in intact tissues, to achieve these effects. PMID:18458330

  3. The phosphorylation of endogenous Nedd4-2 In Na+—absorbing human airway epithelial cells

    PubMed Central

    Ismail, Noor A.S.; Baines, Deborah L.; Wilson, Stuart M.

    2014-01-01

    Neural precursor cell expressed, developmentally down-regulated protein 4-2 (Nedd4-2) mediates the internalisation / degradation of epithelial Na+ channel subunits (α-, β- and γ-ENaC). Serum / glucocorticoid inducible kinase 1 (SGK1) and protein kinase A (PKA) both appear to inhibit this process by phosphorylating Nedd4-2-Ser221, -Ser327 and -Thr246. This Nedd4-2 inactivation process is thought to be central to the hormonal control of Na+ absorption. The present study of H441 human airway epithelial cells therefore explores the effects of SGK1 and / or PKA upon the phosphorylation / abundance of endogenous Nedd4-2; the surface expression of ENaC subunits, and electrogenic Na+ transport. Effects on Nedd4-2 phosphorylation/abundance and the surface expression of ENaC were monitored by western analysis, whilst Na+ absorption was quantified electrometrically. Acutely (20 min) activating PKA in glucocorticoid-deprived (24 h) cells increased the abundance of Ser221-phosphorylated, Ser327-phosphorylated and total Nedd4-2 without altering the abundance of Thr246-phosphorylated Nedd4-2. Activating PKA under these conditions did not cause a co-ordinated increase in the surface abundance of α-, β- and γ-ENaC and had only a very small effect upon electrogenic Na+ absorption. Activating PKA (20 min) in glucocorticoid-treated (0.2 µM dexamethasone, 24 h) cells, on the other hand, increased the abundance of Ser221-, Ser327- and Thr246-phosphorylated and total Nedd4-2; increased the surface abundance of α-, β- and γ-ENaC and evoked a clear stimulation of Na+ transport. Chronic glucocorticoid stimulation therefore appears to allow cAMP-dependent control of Na+ absorption by facilitating the effects of PKA upon the Nedd4-2 and ENaC subunits. PMID:24657276

  4. Bioaerosols from a Food Waste Composting Plant Affect Human Airway Epithelial Cell Remodeling Genes

    PubMed Central

    Chang, Ming-Wei; Lee, Chung-Ru; Hung, Hsueh-Fen; Teng, Kuo-Sheng; Huang, Hsin; Chuang, Chun-Yu

    2013-01-01

    The composting procedure in food waste plants generates airborne bioaerosols that have the potential to damage human airway epithelial cells. Persistent inflammation and repair responses induce airway remodeling and damage to the respiratory system. This study elucidated the expression changes of airway remodeling genes in human lung mucoepidermoid NCI-H292 cells exposed to bioaerosols from a composting plant. Different types of microorganisms were detectable in the composting plant, using the agar culture method. Real-time polymerase chain reaction was used to quantify the level of Aspergillus fumigatus and the profile of remodeling genes. The real-time PCR results indicated that the amount of A. fumigatus in the composting hall was less than 102 conidia. The endotoxins in the field bioaerosols were determined using a limulus amebocyte lysate test. The endotoxin levels depended on the type of particulate matter (PM), with coarse particles (2.5–10 μm) having higher endotoxin levels than did fine particles (0.5–2.5 μm). After exposure to the conditioned medium of field bioaerosol samples, NCI-H292 cells showed increased pro-inflammatory interleukin (IL)-6 release and activated epidermal growth factor receptor (EGFR), transforming growth factor (TGF)-β1 and cyclin-dependent kinase inhibitor 1 (p21WAF1/CIP1) gene expression, but not of matrix metallopeptidase (MMP)-9. Airborne endotoxin levels were higher inside the composting hall than they were in other areas, and they were associated with PM. This suggested that airborne bioaerosols in the composting plant contained endotoxins and microorganisms besides A. fumigatus that cause the inflammatory cytokine secretion and augment the expression of remodeling genes in NCI-H292 cells. It is thus necessary to monitor potentially hazardous materials from bioaerosols in food composting plants, which could affect the health of workers. PMID:24368426

  5. Chromium(VI) stimulates Fyn to initiate innate immune gene induction in human airway epithelial cells

    PubMed Central

    Nemec, Antonia A.; Zubritsky, Lindsey M.; Barchowsky, Aaron

    2009-01-01

    Mechanisms for pathogenic metal signaling in airway injury or disease promotion are poorly understood. It is widely believed that one mechanism for pathogenic and possible carcinogenic effects of inhaled chromium (Cr(VI)) is inhibition of inducible gene transactivation. However, we recently reported that Cr(VI) inhibition of Sp1-dependent transactivation required signal transducer and activator of transcription 1 (STAT1)-dependent expression of an inhibitory protein in airway epithelium. Thus, Cr(VI) exposures can induce genes and we hypothesized this induction resulted from Cr(VI) signaling through an innate immune-like STAT1-dependent pathway initiated by Fyn. Exposure of human airway epithelial (BEAS-2B) cells to Cr(VI) selectively transactivated STAT-responsive interferon-stimulated response element (ISRE) and induced ISRE-driven transactivation of interferon regulatory factor 7 (IRF7), without affecting the gamma interferon-activated site (GAS)-driven IRF1 expression. Cr(VI)-induced IRF7 was absent or greatly reduced in cells that lacked STAT1, were treated with the Src family kinase inhibitor, PP2, or lacked Fyn. Expressing Fyn, but not Src, in mouse embryonic fibroblasts cells null for Src, Yes, and Fyn restored Cr(VI)-stimulated STAT1 tyrosine phosphorylation and IRF7 expression. Finally, shRNA knockdown of Fyn in BEAS-2B cells prevented Cr(VI)-activated STAT1 transactivation of IRF7. These data support a novel mechanism through which Cr(VI) stimulates Fyn to initiate interferon-like signaling for STAT1-dependent gene transactivation. PMID:19994902

  6. Aggregates of mutant CFTR fragments in airway epithelial cells of CF lungs: new pathologic observations.

    PubMed

    Du, Kai; Karp, Philip H; Ackerley, Cameron; Zabner, Joseph; Keshavjee, Shaf; Cutz, Ernest; Yeger, Herman

    2015-03-01

    Cystic fibrosis (CF) is caused by a mutation in the CF transmembrane conductance regulator (CFTR) gene resulting in a loss of Cl(-) channel function, disrupting ion and fluid homeostasis, leading to severe lung disease with airway obstruction due to mucus plugging and inflammation. The most common CFTR mutation, F508del, occurs in 90% of patients causing the mutant CFTR protein to misfold and trigger an endoplasmic reticulum based recycling response. Despite extensive research into the pathobiology of CF lung disease, little attention has been paid to the cellular changes accounting for the pathogenesis of CF lung disease. Here we report a novel finding of intracellular retention and accumulation of a cleaved fragment of F508del CFTR in concert with autophagic like phagolysosomes in the airway epithelium of patients with F508del CFTR. Aggregates consisting of poly-ubiquitinylated fragments of only the N-terminal domain of F508del CFTR but not the full-length molecule accumulate to appreciable levels. Importantly, these undegraded intracytoplasmic aggregates representing the NT-NBD1 domain of F508del CFTR were found in ciliated, in basal, and in pulmonary neuroendocrine cells. Aggregates were found in both native lung tissues and ex-vivo primary cultures of bronchial epithelial cells from CF donors, but not in normal control lungs. Our findings present a new, heretofore, unrecognized innate CF gene related cell defect and a potential contributing factor to the pathogenesis of CF lung disease. Mutant CFTR intracytoplasmic aggregates could be analogous to the accumulation of misfolded proteins in other degenerative disorders and in pulmonary "conformational protein-associated" diseases. Consequently, potential alterations to the functional integrity of airway epithelium and regenerative capacity may represent a critical new element in the pathogenesis of CF lung disease. PMID:25453871

  7. Early events in the pathogenesis of chronic obstructive pulmonary disease. Smoking-induced reprogramming of airway epithelial basal progenitor cells.

    PubMed

    Shaykhiev, Renat; Crystal, Ronald G

    2014-12-01

    The airway epithelium is the primary site of the earliest pathologic changes induced by smoking, contributing to the development of chronic obstructive pulmonary disease (COPD). The normal human airway epithelium is composed of several major cell types, including differentiated ciliated and secretory cells, intermediate undifferentiated cells, and basal cells (BC). BC contain the stem/progenitor cell population responsible for maintenance of the normally differentiated airway epithelium. Although inflammatory and immune processes play a significant role in the pathogenesis of COPD, the earliest lesions include hyperplasia of the BC population, suggesting that the disease may start with this cell type. Apart from BC hyperplasia, smoking induces a number of COPD-relevant airway epithelial remodeling phenotypes that are likely initiated in the BC population, including mucous cell hyperplasia, squamous cell metaplasia, epithelial-mesenchymal transition, altered ciliated and nonmucous secretory cell differentiation, and suppression of junctional barrier integrity. Significant progress has been recently made in understanding the biology of human airway BC, including gene expression features, stem/progenitor, and other functions, including interaction with other airway cell types. Accumulating evidence suggests that human airway BC function as both sensors and cellular sources of various cytokines and growth factors relevant to smoking-associated airway injury, as well as the origin of various molecular and histological phenotypes relevant to the pathogenesis of COPD. In the context of these considerations, we suggest that early BC-specific smoking-induced molecular changes are critical to the pathogenesis of COPD, and these represent a candidate target for novel therapeutic approaches to prevent COPD progression in susceptible individuals. PMID:25525728

  8. Non-Genomic Estrogen Regulation of Ion Transport and Airway Surface Liquid Dynamics in Cystic Fibrosis Bronchial Epithelium

    PubMed Central

    Saint-Criq, Vinciane; Kim, Sung Hoon; Katzenellenbogen, John A.; Harvey, Brian J.

    2013-01-01

    Male cystic fibrosis (CF) patients survive longer than females and lung exacerbations in CF females vary during the estrous cycle. Estrogen has been reported to reduce the height of the airway surface liquid (ASL) in female CF bronchial epithelium. Here we investigated the effect of 17β-estradiol on the airway surface liquid height and ion transport in normal (NuLi-1) and CF (CuFi-1) bronchial epithelial monolayers. Live cell imaging using confocal microscopy revealed that airway surface liquid height was significantly higher in the non-CF cells compared to the CF cells. 17β-estradiol (0.1–10 nM) reduced the airway surface liquid height in non-CF and CF cells after 30 min treatment. Treatment with the nuclear-impeded Estrogen Dendrimer Conjugate mimicked the effect of free estrogen by reducing significantly the airway surface liquid height in CF and non-CF cells. Inhibition of chloride transport or basolateral potassium recycling decreased the airway surface liquid height and 17β-estradiol had no additive effect in the presence of these ion transporter inhibitors. 17β-estradiol decreased bumetanide-sensitive transepithelial short-circuit current in non-CF cells and prevented the forskolin-induced increase in ASL height. 17β-estradiol stimulated an amiloride-sensitive transepithelial current and increased ouabain-sensitive basolateral short-circuit current in CF cells. 17β-estradiol increased PKCδ activity in CF and non-CF cells. These results demonstrate that estrogen dehydrates CF and non-CF ASL, and these responses to 17β-estradiol are non-genomic rather than involving the classical nuclear estrogen receptor pathway. 17β-estradiol acts on the airway surface liquid by inhibiting cAMP-mediated chloride secretion in non-CF cells and increasing sodium absorption via the stimulation of PKCδ, ENaC and the Na+/K+ATPase in CF cells. PMID:24223826

  9. Particulate matter (PM₁₀) induces metalloprotease activity and invasion in airway epithelial cells.

    PubMed

    Morales-Bárcenas, Rocío; Chirino, Yolanda I; Sánchez-Pérez, Yesennia; Osornio-Vargas, Álvaro Román; Melendez-Zajgla, Jorge; Rosas, Irma; García-Cuellar, Claudia María

    2015-09-17

    Airborne particulate matter with an aerodynamic diameter ≤ 10 μm (PM10) is a risk factor for the development of lung diseases and cancer. The aim of this work was to identify alterations in airway epithelial (A549) cells induced by PM10 that could explain how subtoxic exposure (10 μg/cm(2)) promotes a more aggressive in vitro phenotype. Our results showed that cells exposed to PM10 from an industrial zone (IZ) and an urban commercial zone (CZ) induced an increase in protease activity and invasiveness; however, the cell mechanism is different, as only PM10 from CZ up-regulated the activity of metalloproteases MMP-2 and MMP-9 and disrupted E-cadherin/β-catenin expression after 48 h of exposure. These in vitro findings are relevant in terms of the mechanism action of PM10 in lung epithelial cells, which could be helpful in understanding the pathogenesis of some human illness associated with highly polluted cities. PMID:26047787

  10. Activation of CFTR by genistein in human airway epithelial cell lines.

    PubMed

    Andersson, Charlotte; Servetnyk, Zhanna; Roomans, Godfried M

    2003-08-29

    Cystic fibrosis (CF) is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel expressed in epithelial cells. The effects of genistein and 4-phenylbutyrate (PBA) on CFTR were studied in three human airway epithelial cell lines expressing wild-type or DeltaF508 CFTR: Calu-3, CFSMEo-, and CFBE41o- cells. The cells were loaded with the fluorescent dye N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE) and chloride efflux was studied. Forskolin and 3-isobutyl-1-methylxanthine (IBMX) induced chloride efflux in Calu-3 cells but not in CF lines. Genistein (2.5-50 microM) alone was able to induce chloride efflux in all cell lines. Genistein did not enhance the effect of forskolin and IBMX. PBA had little or no effect on genistein-induced chloride efflux. The effect of genistein seen at low concentrations makes genistein interesting for possible pharmacological treatment of CF, since it is known that similar concentrations can be obtained in plasma by a soy-rich diet. PMID:12914781

  11. Human Airway Primary Epithelial Cells Show Distinct Architectures on Membrane Supports Under Different Culture Conditions.

    PubMed

    Min, Kyoung Ah; Rosania, Gus R; Shin, Meong Cheol

    2016-06-01

    To facilitate drug development for lung delivery, it is highly demanding to establish appropriate airway epithelial cell models as transport barriers to evaluate pharmacokinetic profiles of drug molecules. Besides the cancer-derived cell lines, as the primary cell model, normal human bronchial epithelial (NHBE) cells have been used for drug screenings because of physiological relevance to in vivo. Therefore, to accurately interpret drug transport data in NHBE measured by different laboratories, it is important to know biophysical characteristics of NHBE grown on membranes in different culture conditions. In this study, NHBE was grown on the polyester membrane in a different medium and its transport barrier properties as well as cell architectures were fully characterized by functional assays and confocal imaging throughout the days of cultures. Moreover, NHBE cells on inserts in a different medium were subject to either of air-interfaced culture (AIC) or liquid-covered culture (LCC) condition. Cells in the AIC condition were cultivated on the membrane with medium in the basolateral side only, whereas cells with medium in apical and basolateral sides under the LCC condition. Quantitative microscopic imaging with biophysical examination revealed distinct multilayered architectures of differentiated NHBE cells, suggesting NHBE as functional cell barriers for the lung-targeting drug transport. PMID:26818810

  12. Differential interaction of bacterial species from the Burkholderia cepacia complex with human airway epithelial cells.

    PubMed

    Moura, Jane A; Cristina de Assis, Maria; Ventura, Grasiella C; Saliba, Alessandra M; Gonzaga, Luiz; Si-Tahar, Mustapha; Marques, Elizabeth de A; Plotkowski, Maria Cristina

    2008-01-01

    To increase knowledge of the pathogenic potential of the Burkholderia cepacia complex (BCC), we investigated the effects of reference strains of the nine BCC species on human bronchial epithelial cells in vitro. B. multivorans exhibited the highest rates of adherence to and internalization by host cells. Two out of three clinical isolates recovered from cystic fibrosis patients confirmed the B. multivorans high adhesiveness. All four B. multivorans isolates exhibited an aggregated pattern of adherence but any of them expressed cable pili. When bacteria were centrifuged onto cell cultures to circumvent their poor adhesiveness, B. pyrrocinia exhibited the highest internalization rate, followed by B. multivorans. The percentages of apoptotic cells in cultures infected with B. cepacia, B. multivorans, B. cenocepacia (subgroups IIIA and IIIB), B. stabilis and B. vietnamiensis were significantly higher than in control non-infected cultures. All nine BCC species triggered a similar release of the inflammatory cytokine IL-8, that was not reduced by cell treatment with cytochalasin D. Hence, our data demonstrate, for the first time, that all BCC species exhibit a similar ability to induce the expression of host immune mediators whereas they differ on their ability to adhere to, invade and kill airway epithelial cells. PMID:18068390

  13. Airway epithelial cells activate Th2 cytokine production in mast cells via IL-1 and thymic stromal lymphopoietin

    PubMed Central

    Nagarkar, Deepti R.; Poposki, Julie A.; Comeau, Michael R.; Biyasheva, Assel; Avila, Pedro C.; Schleimer, Robert P.; Kato, Atsushi

    2012-01-01

    Background Airway epithelial cells are important regulators of innate and adaptive immunity. Although mast cells are known to play a central role in manifestations of allergic inflammation and are found in the epithelium in Th2-related diseases, their role is incompletely understood. Objectives The objective of this study was to investigate the role of airway epithelial cells in production of Th2 cytokines in mast cells. Methods Normal human bronchial epithelial cells (NHBE) were stimulated with TNF, IL-4, IFN-γ, IL -17A and dsRNA alone or in combination. Human mast cells were stimulated with epithelial cell-derived supernatants, or co-cultured with NHBE. Th2 cytokine responses were blocked with neutralizing antibodies. Results Supernatants from IL-4 and dsRNA stimulated NHBE significantly enhanced Th2 cytokine production from mast cells. The combination of IL-4 and dsRNA itself or supernatants from NHBE stimulated with other cytokines did not activate mast cells, suggesting that mast cell responses were induced by epithelial cell factors that were only induced by IL-4 and dsRNA. Epithelial supernatant-dependent Th2 cytokine production in mast cells was suppressed by anti-IL-1 and anti-TSLP, and was enhanced by anti-IL-1Ra. Similar results were observed in co-culture experiments. Finally, we found dsRNA-dependent production of IL-1, TSLP, and IL-1Ra in NHBE was regulated by Th cytokines, and their ratio in NHBE correlated with Th2 cytokine production in mast cells. Conclusions Pathogens producing dsRNA, such as respiratory viral infections, may amplify local Th2 inflammation in asthmatics via the production of TSLP and IL-1 by epithelial cells and subsequent activation of Th2 cytokine production by mast cells in the airways. PMID:22633328

  14. Automated acquisition and analysis of airway surface liquid height by confocal microscopy

    PubMed Central

    Choi, Hyun-Chul; Kim, Christine Seul Ki

    2015-01-01

    The airway surface liquid (ASL) is a thin-liquid layer that lines the luminal side of airway epithelia. ASL contains many molecules that are involved in primary innate defense in the lung. Measurement of ASL height on primary airway cultures by confocal microscopy is a powerful tool that has enabled researchers to study ASL physiology and pharmacology. Previously, ASL image acquisition and analysis were performed manually. However, this process is time and labor intensive. To increase the throughput, we have developed an automatic ASL measurement technique that combines a fully automated confocal microscope with novel automatic image analysis software that was written with image processing techniques derived from the computer science field. We were able to acquire XZ ASL images at the rate of ∼1 image/s in a reproducible fashion. Our automatic analysis software was able to analyze images at the rate of ∼32 ms/image. As proofs of concept, we generated a time course for ASL absorption and a dose response in the presence of SPLUNC1, a known epithelial sodium channel inhibitor, on human bronchial epithelial cultures. Using this approach, we determined the IC50 for SPLUNC1 to be 6.53 μM. Furthermore, our technique successfully detected a difference in ASL height between normal and cystic fibrosis (CF) human bronchial epithelial cultures and detected changes in ATP-stimulated Cl−/ASL secretion. We conclude that our automatic ASL measurement technique can be applied for repeated ASL height measurements with high accuracy and consistency and increased throughput. PMID:26001773

  15. Chemotaxis and Binding of Pseudomonas aeruginosa to Scratch-Wounded Human Cystic Fibrosis Airway Epithelial Cells

    PubMed Central

    Schwarzer, Christian; Fischer, Horst; Machen, Terry E.

    2016-01-01

    Confocal imaging was used to characterize interactions of Pseudomonas aeruginosa (PA, expressing GFP or labeled with Syto 11) with CF airway epithelial cells (CFBE41o-, grown as confluent monolayers with unknown polarity on coverglasses) in control conditions and following scratch wounding. Epithelia and PAO1-GFP or PAK-GFP (2 MOI) were incubated with Ringer containing typical extracellular salts, pH and glucose and propidium iodide (PI, to identify dead cells). PAO1 and PAK swam randomly over and did not bind to nonwounded CFBE41o- cells. PA migrated rapidly (began within 20 sec, maximum by 5 mins) and massively (10–80 fold increase, termed “swarming”), but transiently (random swimming after 15 mins), to wounds, particularly near cells that took up PI. Some PA remained immobilized on cells near the wound. PA swam randomly over intact CFBE41o- monolayers and wounded monolayers that had been incubated with medium for 1 hr. Expression of CFTR and altered pH of the media did not affect PA interactions with CFBE41o- wounds. In contrast, PAO1 swarming and immobilization along wounds was abolished in PAO1 (PAO1ΔcheYZABW, no expression of chemotaxis regulatory components cheY, cheZ, cheA, cheB and cheW) and greatly reduced in PAO1 that did not express amino acid receptors pctA, B and C (PAO1ΔpctABC) and in PAO1 incubated in Ringer containing a high concentration of mixed amino acids. Non-piliated PAKΔpilA swarmed normally towards wounded areas but bound infrequently to CFBE41o- cells. In contrast, both swarming and binding of PA to CFBE41o- cells near wounds were prevented in non-flagellated PAKΔfliC. Data are consistent with the idea that (i) PA use amino acid sensor-driven chemotaxis and flagella-driven swimming to swarm to CF airway epithelial cells near wounds and (ii) PA use pili to bind to epithelial cells near wounds. PMID:27031335

  16. Role of neutrophilic inflammation in ozone-induced epithelial alterations in the nasal airways of rats

    NASA Astrophysics Data System (ADS)

    Cho, Hye Youn

    Ozone is a principal oxidant air pollutant in photochemical smog. Epithelial cells lining the centriacinar region of lung and the proximal aspects of nasal passage are primary target sites for ozone-induced injury in laboratory animals. Acute exposure of rats to high ambient concentrations of ozone (e.g., 0.5 ppm) results in neutrophilic inflammation, epithelial hyperplasia and mucous cell metaplasia (MCM) in the nasal transitional epithelium (NTE) lining the proximal nasal airways. The principal purpose of the present study was to investigate the role of pre-metaplastic cellular responses, especially neutrophilic inflammation, in the pathogenesis of ozone-induced MCM in rat NTE. For this purpose, three specific hypotheses-based whole-animal inhalation studies were conducted. Male F344/N rats were exposed in whole-body inhalation chambers to 0 (filtered air) or 0.5 ppm ozone for 1-3 days (8 h/day). Histochemical, immunochemical, molecular and morphometric techniques were used to investigate the ozone-induced cellular and molecular events in the NTE. Two in vitro studies were also conducted to examine the effects of ozone-inducible cytokines (i.e., tumor necrosis factor-alpha; TNF- a, and interleukin-6; IL-6) on mucin gene (rMuc-5AC) expression. Ozone induced a rapid increase of rMuc-5AC mRNA in nasal tissues within hours after the start of exposure. It preceded the appearance of MCM, and persisted with MCM. Ozone-induced neutrophilic inflammation accompanied the mucin gene upregulation, but was resolved when MCM first appeared in the NTE. Antibody-mediated depletion of circulating neutrophils attenuated ozone-induced MCM, although it did not affect the ozone-induced epithelial hyperplasia and mucin mRNA upregulation. In another study, it was found that preexisting neutrophilic rhinitis induced by endotoxin augmented the ozone-induced MCM. However, pre-existing rhinitis did not alter the severity of ozone-induced epithelial hyperplasia and mucin gene upregulation

  17. Ex Vivo Chemical Cytometric Analysis of Protein Tyrosine Phosphatase Activity in Single Human Airway Epithelial Cells

    PubMed Central

    Phillips, Ryan M.; Dailey, Lisa A.; Bair, Eric; Samet, James M.; Allbritton, Nancy L.

    2014-01-01

    We describe a novel method for the measurement of protein tyrosine phosphatase (PTP) activity in single human airway epithelial cells (hAECs) using capillary electrophoresis. This technique involved the microinjection of a fluorescent phosphopeptide that is hydrolyzed specifically by PTPs. Analyses in BEAS-2B immortalized bronchial epithelial cells showed rapid PTP-mediated dephosphorylation of the substrate (2.2 pmol min−1 mg−1) that was blocked by pretreatment of the cells with the PTP inhibitors pervanadate, Zn2+, and 1,2-naphthoquinone (76%, 69%, 100% inhibition relative to PTP activity in untreated controls, respectively). These studies were then extended to a more physiologically relevant model system: primary hAECs cultured from bronchial brushings of living human subjects. In primary hAECs, dephosphorylation of the substrate occurred at a rate of 2.2 pmol min−1 mg−1, and was also effectively inhibited by pre-incubation of the cells with the inhibitors pervanadate, Zn2+, and 1,2- naphthoquinone (91%, 88%, and 87% median PTP inhibition, respectively). Reporter proteolysis in single BEAS-2B cells occurred at a median rate of 43 fmol min−1 mg−1 resulting in a mean half-life of 20 min. The reporter displayed a similar median half-life of 28 min in these single primary cells. Finally, single viable epithelial cells (which were assayed for PTP activity immediately after collection by bronchial brushing of a human volunteer) showed dephosphorylation rates ranging from 0.34–36 pmol min−1 mg−1 (n = 6). These results demonstrate the utility and applicability of this technique for the ex vivo quantification of PTP activity in small, heterogeneous, human cells and tissues. PMID:24380370

  18. Comprehensive evaluation of poly(I:C) induced inflammatory response in an airway epithelial model

    PubMed Central

    Lever, Amanda R; Park, Hyoungshin; Mulhern, Thomas J; Jackson, George R; Comolli, James C; Borenstein, Jeffrey T; Hayden, Patrick J; Prantil-Baun, Rachelle

    2015-01-01

    Respiratory viruses invade the upper airway of the lung, triggering a potent immune response that often exacerbates preexisting conditions such as asthma and COPD. Poly(I:C) is a synthetic analog of viral dsRNA that induces the characteristic inflammatory response associated with viral infection, such as loss of epithelial integrity, and increased production of mucus and inflammatory cytokines. Here, we explore the mechanistic responses to poly(I:C) in a well-defined primary normal human bronchial epithelial (NHBE) model that recapitulates in vivo functions and responses. We developed functional and quantifiable methods to evaluate the physiology of our model in both healthy and inflamed states. Through gene and protein expression, we validated the differentiation state and population of essential cell subtypes (i.e., ciliated, goblet, club, and basal cells) as compared to the human lung. Assays for total mucus production, cytokine secretion, and barrier function were used to evaluate in vitro physiology and response to viral insult. Cells were treated apically with poly(I:C) and evaluated 48 h after induction. Results revealed a dose-dependent increase in goblet cell differentiation, as well as, an increase in mucus production relative to controls. There was also a dose-dependent increase in secretion of IL-6, IL-8, TNF-α, and RANTES. Epithelial barrier function, as measured by TEER, was maintained at 1501 ± 355 Ω*cm² postdifferentiation, but dropped significantly when challenged with poly(I:C). This study provides first steps toward a well-characterized model with defined functional methods for understanding dsRNA stimulated inflammatory responses in a physiologically relevant manner. PMID:25847914

  19. Molecular insights into the physiology of the ‘thin film’ of airway surface liquid

    PubMed Central

    Boucher, R C

    1999-01-01

    The epithelia that line the airways of the lung exhibit two general functions: (1) airway epithelia in all regions ‘defend’ the lung against infectious and noxious agents; and (2) airway epithelia in the proximal regions replenish water lost from airway surfaces, i.e. the ‘insensible water loss’, consequent to conditioning inspired air. How airway epithelia perform both functions, and co-ordinate them in health and disease, is the subject of this review. PMID:10200413

  20. Toll-like receptor 4 is not targeted to the lysosome in cystic fibrosis airway epithelial cells

    PubMed Central

    Kelly, Catriona; Canning, Paul; Buchanan, Paul J.; Williams, Mark T.; Brown, Vanessa; Gruenert, Dieter C.; Elborn, J. Stuart; Ennis, Madeleine

    2013-01-01

    The innate immune response to bacterial infection is mediated through Toll-like receptors (TLRs), which trigger tightly regulated signaling cascades through transcription factors including NF-κB. LPS activation of TLR4 triggers internalization of the receptor-ligand complex which is directed toward lysosomal degradation or endocytic recycling. Cystic fibrosis (CF) patients display a robust and uncontrolled inflammatory response to bacterial infection, suggesting a defect in regulation. This study examined the intracellular trafficking of TLR4 in CF and non-CF airway epithelial cells following stimulation with LPS. We employed cells lines [16hBE14o-, CFBE41o- (CF), and CFTR-complemented CFBE41o-] and confirmed selected experiments in primary nasal epithelial cells from non-CF controls and CF patients (F508del homozygous). In control cells, TLR4 expression (surface and cytoplasmic) was reduced after LPS stimulation but remained unchanged in CF cells and was accompanied by a heightened inflammatory response 24 h after stimulation. All cells expressed markers of the early (EEA1) and late (Rab7b) endosomes at basal levels. However, only CF cells displayed persistent expression of Rab7b following LPS stimulation. Rab7 variants may directly internalize bacteria to the Golgi for recycling or to the lysosome for degradation. TLR4 colocalized with the lysosomal marker LAMP1 in 16 hBE14o- cells, suggesting that TLR4 is targeted for lysosomal degradation in these cells. However, this colocalization was not observed in CFBE41o- cells, where persistent expression of Rab7 and release of proinflammatory cytokines was detected. Consistent with the apparent inability of CF cells to target TLR4 toward the lysosome for degradation, we observed persistent surface and cytoplasmic expression of this pathogen recognition receptor. This defect may account for the prolonged cycle of chronic inflammation associated with CF. PMID:23316065

  1. Identification of the SPLUNC1 ENaC-inhibitory domain yields novel strategies to treat sodium hyperabsorption in cystic fibrosis airway epithelial cultures.

    PubMed

    Hobbs, Carey A; Blanchard, Maxime G; Alijevic, Omar; Tan, Chong Da; Kellenberger, Stephan; Bencharit, Sompop; Cao, Rui; Kesimer, Mehmet; Walton, William G; Henderson, Ashley G; Redinbo, Matthew R; Stutts, M Jackson; Tarran, Robert

    2013-12-01

    The epithelial sodium channel (ENaC) is responsible for Na(+) and fluid absorption across colon, kidney, and airway epithelia. Short palate lung and nasal epithelial clone 1 (SPLUNC1) is a secreted, innate defense protein and an autocrine inhibitor of ENaC that is highly expressed in airway epithelia. While SPLUNC1 has a bactericidal permeability-increasing protein (BPI)-type structure, its NH2-terminal region lacks structure. Here we found that an 18 amino acid peptide, S18, which corresponded to residues G22-A39 of the SPLUNC1 NH2 terminus inhibited ENaC activity to a similar degree as full-length SPLUNC1 (∼2.5 fold), while SPLUNC1 protein lacking this region was without effect. S18 did not inhibit the structurally related acid-sensing ion channels, indicating specificity for ENaC. However, S18 preferentially bound to the βENaC subunit in a glycosylation-dependent manner. ENaC hyperactivity is contributory to cystic fibrosis (CF) lung disease. Unlike control, CF human bronchial epithelial cultures (HBECs) where airway surface liquid (ASL) height was abnormally low (4.2 ± 0.6 μm), addition of S18 prevented ENaC-led ASL hyperabsorption and maintained CF ASL height at 7.9 ± 0.6 μm, even in the presence of neutrophil elastase, which is comparable to heights seen in normal HBECs. Our data also indicate that the ENaC inhibitory domain of SPLUNC1 may be cleaved away from the main molecule by neutrophil elastase, suggesting that it may still be active during inflammation or neutrophilia. Furthermore, the robust inhibition of ENaC by the S18 peptide suggests that this peptide may be suitable for treating CF lung disease. PMID:24124190

  2. Identification of the SPLUNC1 ENaC-inhibitory domain yields novel strategies to treat sodium hyperabsorption in cystic fibrosis airway epithelial cultures

    PubMed Central

    Hobbs, Carey A.; Blanchard, Maxime G.; Alijevic, Omar; Tan, Chong Da; Kellenberger, Stephan; Bencharit, Sompop; Cao, Rui; Kesimer, Mehmet; Walton, William G.; Henderson, Ashley G.; Redinbo, Matthew R.; Stutts, M. Jackson

    2013-01-01

    The epithelial sodium channel (ENaC) is responsible for Na+ and fluid absorption across colon, kidney, and airway epithelia. Short palate lung and nasal epithelial clone 1 (SPLUNC1) is a secreted, innate defense protein and an autocrine inhibitor of ENaC that is highly expressed in airway epithelia. While SPLUNC1 has a bactericidal permeability-increasing protein (BPI)-type structure, its NH2-terminal region lacks structure. Here we found that an 18 amino acid peptide, S18, which corresponded to residues G22-A39 of the SPLUNC1 NH2 terminus inhibited ENaC activity to a similar degree as full-length SPLUNC1 (∼2.5 fold), while SPLUNC1 protein lacking this region was without effect. S18 did not inhibit the structurally related acid-sensing ion channels, indicating specificity for ENaC. However, S18 preferentially bound to the βENaC subunit in a glycosylation-dependent manner. ENaC hyperactivity is contributory to cystic fibrosis (CF) lung disease. Unlike control, CF human bronchial epithelial cultures (HBECs) where airway surface liquid (ASL) height was abnormally low (4.2 ± 0.6 μm), addition of S18 prevented ENaC-led ASL hyperabsorption and maintained CF ASL height at 7.9 ± 0.6 μm, even in the presence of neutrophil elastase, which is comparable to heights seen in normal HBECs. Our data also indicate that the ENaC inhibitory domain of SPLUNC1 may be cleaved away from the main molecule by neutrophil elastase, suggesting that it may still be active during inflammation or neutrophilia. Furthermore, the robust inhibition of ENaC by the S18 peptide suggests that this peptide may be suitable for treating CF lung disease. PMID:24124190

  3. AMP-activated protein kinase (AMPK)–dependent and –independent pathways regulate hypoxic inhibition of transepithelial Na+ transport across human airway epithelial cells

    PubMed Central

    Tan, CD; Smolenski, RT; Harhun, MI; Patel, HK; Ahmed, SG; Wanisch, K; Yáñez-Muñoz, RJ; Baines, DL

    2012-01-01

    BACKGROUND AND PURPOSE Pulmonary transepithelial Na+ transport is reduced by hypoxia, but in the airway the regulatory mechanisms remain unclear. We investigated the role of AMPK and ROS in the hypoxic regulation of apical amiloride-sensitive Na+ channels and basolateral Na+K+ ATPase activity. EXPERIMENTAL APPROACH H441 human airway epithelial cells were used to examine the effects of hypoxia on Na+ transport, AMP : ATP ratio and AMPK activity. Lentiviral constructs were used to modify cellular AMPK abundance and activity; pharmacological agents were used to modify cellular ROS. KEY RESULTS AMPK was activated by exposure to 3% or 0.2% O2 for 60 min in cells grown in submerged culture or when fluid (0.1 mL·cm−2) was added to the apical surface of cells grown at the air–liquid interface. Only 0.2% O2 activated AMPK in cells grown at the air–liquid interface. AMPK activation was associated with elevation of cellular AMP : ATP ratio and activity of the upstream kinase LKB1. Hypoxia inhibited basolateral ouabain-sensitive Isc (Iouabain) and apical amiloride-sensitive Na+ conductance (GNa+). Modification of AMPK activity prevented the effect of hypoxia on Iouabain (Na+K+ ATPase) but not apical GNa+. Scavenging of superoxide and inhibition of NADPH oxidase prevented the effect of hypoxia on apical GNa+ (epithelial Na+ channels). CONCLUSIONS AND IMPLICATIONS Hypoxia activates AMPK-dependent and -independent pathways in airway epithelial cells. Importantly, these pathways differentially regulate apical Na+ channels and basolateral Na+K+ ATPase activity to decrease transepithelial Na+ transport. Luminal fluid potentiated the effect of hypoxia and activated AMPK, which could have important consequences in lung disease conditions. PMID:22509822

  4. REGULATION OF CYTOKINE PRODUCTION IN HUMAN ALVEOLAR MACHROPHAGES AND AIRWAY EPITHELIAL CELLS IN RESPONSE TO AMBIENT AIR POLLUTION PARTICLES: FURTHER MECHANISTIC STUDIES

    EPA Science Inventory

    In order to better understand how ambient air particulate matter (PM) affect lung health, the two main airway cell types likely to interact with inhaled particles, alveolar macrophages (AM) and airway epithelial cells have been exposed to particles in vitro and followed for endp...

  5. Ozone-induced airway epithelial cell death, the neurokinin-1 receptor pathway, and the postnatal developing lung

    PubMed Central

    Murphy, Shannon R.; Oslund, Karen L.; Hyde, Dallas M.; Miller, Lisa A.; Van Winkle, Laura S.

    2014-01-01

    Children are uniquely susceptible to ozone because airway and lung growth continue for an extensive period after birth. Early-life exposure of the rhesus monkey to repeated ozone cycles results in region-specific disrupted airway/lung growth, but the mediators and mechanisms are poorly understood. Substance P (SP), neurokinin-1 receptor (NK-1R); and nuclear receptor Nur77 (NR4A1) are signaling pathway components involved in ozone-induced cell death. We hypothesize that acute ozone (AO) exposure during postnatal airway development disrupts SP/NK-1R/Nur77 pathway expression and that these changes correlate with increased ozone-induced cell death. Our objectives were to 1) spatially define the normal development of the SP/NK-1R/Nur77 pathway in conducting airways; 2) compare how postnatal age modulates responses to AO exposure; and 3) determine how concomitant, episodic ozone exposure modifies age-specific acute responses. Male infant rhesus monkeys were assigned at age 1 mo to two age groups, 2 or 6 mo, and then to one of three exposure subgroups: filtered air (FA), FA+AO (AO: 8 h/day × 2 days), or episodic biweekly ozone exposure cycles (EAO: 8 h/day × 5 days/14-day cycle+AO). O3 = 0.5 ppm. We found that 1) ozone increases SP/NK-1R/Nur77 pathway expression in conducting airways, 2) an ozone exposure cycle (5 days/cycle) delivered early at age 2 mo resulted in an airway that was hypersensitive to AO exposure at the end of 2 mo, and 3) continued episodic exposure (11 cycles) resulted in an airway that was hyposensitive to AO exposure at 6 mo. These observations collectively associate with greater overall inflammation and epithelial cell death, particularly in early postnatal (2 mo), distal airways. PMID:25063800

  6. Persistent rhinitis and epithelial remodeling induced by cyclic ozone exposure in the nasal airways of infant monkeys

    PubMed Central

    Ballinger, Carol A.; Plopper, Charles G.; McDonald, Ruth J.; Bartolucci, Alfred A.; Postlethwait, Edward M.; Harkema, Jack R.

    2011-01-01

    Children chronically exposed to high levels of ozone (O3), the principal oxidant pollutant in photochemical smog, are more vulnerable to respiratory illness and infections. The specific factors underlying this differential susceptibility are unknown but may be related to air pollutant-induced nasal alterations during postnatal development that impair the normal physiological functions (e.g., filtration and mucociliary clearance) serving to protect the more distal airways from inhaled xenobiotics. In adult animal models, chronic ozone exposure is associated with adaptations leading to a decrease in airway injury. The purpose of our study was to determine whether cyclic ozone exposure induces persistent morphological and biochemical effects on the developing nasal airways of infant monkeys early in life. Infant (180-day-old) rhesus macaques were exposed to 5 consecutive days of O3 [0.5 parts per million (ppm), 8 h/day; “1-cycle”] or filtered air (FA) or 11 biweekly cycles of O3 (FA days 1–9; 0.5 ppm, 8 h/day on days 10–14; “11-cycle”). The left nasal passage was processed for light microscopy and morphometric analysis. Mucosal samples from the right nasal passage were processed for GSH, GSSG, ascorbate (AH2), and uric acid (UA) concentration. Eleven-cycle O3 induced persistent rhinitis, squamous metaplasia, and epithelial hyperplasia in the anterior nasal airways of infant monkeys, resulting in a 39% increase in the numeric density of epithelial cells. Eleven-cycle O3 also induced a 65% increase in GSH concentrations at this site. The persistence of epithelial hyperplasia was positively correlated with changes in GSH. These results indicate that early life ozone exposure causes persistent nasal epithelial alterations in infant monkeys and provide a potential mechanism for the increased susceptibility to respiratory illness exhibited by children in polluted environments. PMID:21131400

  7. Differential transcriptional regulation of IL-8 expression by human airway epithelial cells exposed to diesel exhaust particles

    SciTech Connect

    Tal, Tamara L.; Simmons, Steven O.; Silbajoris, Robert; Dailey, Lisa; Cho, Seung-Hyun; Ramabhadran, Ram; Linak, William; Reed, William; Bromberg, Philip A.; Samet, James M.

    2010-02-15

    Exposure to diesel exhaust particles (DEP) induces inflammatory signaling characterized by MAP kinase-mediated activation of NFkB and AP-1 in vitro and in bronchial biopsies obtained from human subjects exposed to DEP. NFkB and AP-1 activation results in the upregulation of genes involved in promoting inflammation in airway epithelial cells, a principal target of inhaled DEP. IL-8 is a proinflammatory chemokine expressed by the airway epithelium in response to environmental pollutants. The mechanism by which DEP exposure induces IL-8 expression is not well understood. In the current study, we sought to determine whether DEP with varying organic content induces IL-8 expression in lung epithelial cells, as well as, to develop a method to rapidly evaluate the upstream mechanism(s) by which DEP induces IL-8 expression. Exposure to DEP with varying organic content differentially induced IL-8 expression and IL-8 promoter activity human airway epithelial cells. Mutational analysis of the IL-8 promoter was also performed using recombinant human cell lines expressing reporters linked to the mutated promoters. Treatment with a low organic-containing DEP stimulated IL-8 expression by a mechanism that is predominantly NFkB-dependent. In contrast, exposure to high organic-containing DEP induced IL-8 expression independently of NFkB through a mechanism that requires AP-1 activity. Our study reveals that exposure to DEP of varying organic content induces proinflammatory gene expression through multiple specific mechanisms in human airway epithelial cells. The approaches used in the present study demonstrate the utility of a promoter-reporter assay ensemble for identifying transcriptional pathways activated by pollutant exposure.

  8. Expression of cystic fibrosis transmembrane conductance regulator corrects defective chloride channel regulation in cystic fibrosis airway epithelial cells

    NASA Astrophysics Data System (ADS)

    Rich, Devra P.; Anderson, Matthew P.; Gregory, Richard J.; Cheng, Seng H.; Paul, Sucharita; Jefferson, Douglas M.; McCann, John D.; Klinger, Katherine W.; Smith, Alan E.; Welsh, Michael J.

    1990-09-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) was expressed in cultured cystic fibrosis airway epithelial cells and Cl- channel activation assessed in single cells using a fluorescence microscopic assay and the patch-clamp technique. Expression of CFTR, but not of a mutant form of CFTR (ΔF508), corrected the Cl- channel defect. Correction of the phenotypic defect demonstrates a causal relationship between mutations in the CFTR gene and defective Cl- transport which is the hallmark of the disease.

  9. Persistent rhinitis and epithelial remodeling induced by cyclic ozone exposure in the nasal airways of infant monkeys.

    PubMed

    Carey, Stephan A; Ballinger, Carol A; Plopper, Charles G; McDonald, Ruth J; Bartolucci, Alfred A; Postlethwait, Edward M; Harkema, Jack R

    2011-02-01

    Children chronically exposed to high levels of ozone (O(3)), the principal oxidant pollutant in photochemical smog, are more vulnerable to respiratory illness and infections. The specific factors underlying this differential susceptibility are unknown but may be related to air pollutant-induced nasal alterations during postnatal development that impair the normal physiological functions (e.g., filtration and mucociliary clearance) serving to protect the more distal airways from inhaled xenobiotics. In adult animal models, chronic ozone exposure is associated with adaptations leading to a decrease in airway injury. The purpose of our study was to determine whether cyclic ozone exposure induces persistent morphological and biochemical effects on the developing nasal airways of infant monkeys early in life. Infant (180-day-old) rhesus macaques were exposed to 5 consecutive days of O(3) [0.5 parts per million (ppm), 8 h/day; "1-cycle"] or filtered air (FA) or 11 biweekly cycles of O(3) (FA days 1-9; 0.5 ppm, 8 h/day on days 10-14; "11-cycle"). The left nasal passage was processed for light microscopy and morphometric analysis. Mucosal samples from the right nasal passage were processed for GSH, GSSG, ascorbate (AH(2)), and uric acid (UA) concentration. Eleven-cycle O(3) induced persistent rhinitis, squamous metaplasia, and epithelial hyperplasia in the anterior nasal airways of infant monkeys, resulting in a 39% increase in the numeric density of epithelial cells. Eleven-cycle O(3) also induced a 65% increase in GSH concentrations at this site. The persistence of epithelial hyperplasia was positively correlated with changes in GSH. These results indicate that early life ozone exposure causes persistent nasal epithelial alterations in infant monkeys and provide a potential mechanism for the increased susceptibility to respiratory illness exhibited by children in polluted environments. PMID:21131400

  10. Inhibition of the interactions between eosinophil cationic protein and airway epithelial cells by traditional Chinese herbs

    PubMed Central

    2010-01-01

    Background The eosinophil cationic protein (ECP) is cytotoxic to bacteria, viruses, parasites and mammalian cells. Cells are damaged via processes of pore formation, permeability alteration and membrane leaking. Some clinical studies indicate that ECP gathers in the bronchial tract of asthma sufferers, damages bronchial and airway epithelial cells, and leads to in breathing tract inflammation; therefore, prevention of the cytotoxicity caused by ECP may serve as an approach to treat airway inflammation. To achieve the purpose, reduction of the ECP-cell interactions is rational. In this work, the Chinese herbal combinative network was generated to predict and identify the functional herbs from the pools of prescriptions. It was useful to select the node herbs and to demonstrate the relative binding ability between ECP and Beas-2B cells with or withour herb treatments. Results Eighty three Chinese herbs and prescriptions were tested and five effective herbs and six prescription candidates were selected. On the basis of effective single-herbal drugs and prescriptions, a combinative network was generated. We found that a single herb, Gan-cao, served as a node connecting five prescriptions. In addition, Sheng-di-huang, Dang-guei and Mu-tong also appeared in five, four and three kinds of prescriptions, respectively. The extracts of these three herbs indeed effectively inhibited the interactions between ECP and Beas-2B cells. According to the Chinese herbal combinative network, eight of the effective herbal extracts showed inhibitory effects for ECP internalizing into Beas-2B cells. The major components of Gang-cao and Sheng-di-huang, glycyrrhizic acid and verbascose, respectively, reduced the binding affinity between ECP and cells effectively. Conclusions Since these Chinese herbs reduced the binding affinity between ECP and cells and inhibited subsequent ECP entrance into cells, they were potential for mitigating the airway inflammation symptoms. Additionally, we

  11. Recruited alveolar macrophages, in response to airway epithelial-derived monocyte chemoattractant protein 1/CCl2, regulate airway inflammation and remodeling in allergic asthma.

    PubMed

    Lee, Yong Gyu; Jeong, Jong Jin; Nyenhuis, Sharmilee; Berdyshev, Evgeny; Chung, Sangwoon; Ranjan, Ravi; Karpurapu, Manjula; Deng, Jing; Qian, Feng; Kelly, Elizabeth A B; Jarjour, Nizar N; Ackerman, Steven J; Natarajan, Viswanathan; Christman, John W; Park, Gye Young

    2015-06-01

    Although alveolar macrophages (AMs) from patients with asthma are known to be functionally different from those of healthy individuals, the mechanism by which this transformation occurs has not been fully elucidated in asthma. The goal of this study was to define the mechanisms that control AM phenotypic and functional transformation in response to acute allergic airway inflammation. The phenotype and functional characteristics of AMs obtained from human subjects with asthma after subsegmental bronchoprovocation with allergen was studied. Using macrophage-depleted mice, the role and trafficking of AM populations was determined using an acute allergic lung inflammation model. We observed that depletion of AMs in a mouse allergic asthma model attenuates Th2-type allergic lung inflammation and its consequent airway remodeling. In both human and mouse, endobronchial challenge with allergen induced a marked increase in monocyte chemotactic proteins (MCPs) in bronchoalveolar fluid, concomitant with the rapid appearance of a monocyte-derived population of AMs. Furthermore, airway allergen challenge of allergic subjects with mild asthma skewed the pattern of AM gene expression toward high levels of the receptor for MCP1 (CCR2/MCP1R) and expression of M2 phenotypic proteins, whereas most proinflammatory genes were highly suppressed. CCL2/MCP-1 gene expression was prominent in bronchial epithelial cells in a mouse allergic asthma model, and in vitro studies indicate that bronchial epithelial cells produced abundant MCP-1 in response to house dust mite allergen. Thus, our study indicates that bronchial allergen challenge induces the recruitment of blood monocytes along a chemotactic gradient generated by allergen-exposed bronchial epithelial cells. PMID:25360868

  12. Pseudomonas aeruginosa Reduces VX-809 Stimulated F508del-CFTR Chloride Secretion by Airway Epithelial Cells

    PubMed Central

    Stanton, Bruce A.; Coutermarsh, Bonita; Barnaby, Roxanna; Hogan, Deborah

    2015-01-01

    Background P. aeruginosa is an opportunistic pathogen that chronically infects the lungs of 85% of adult patients with Cystic Fibrosis (CF). Previously, we demonstrated that P. aeruginosa reduced wt-CFTR Cl secretion by airway epithelial cells. Recently, a new investigational drug VX-809 has been shown to increase F508del-CFTR Cl secretion in human bronchial epithelial (HBE) cells, and, in combination with VX-770, to increase FEV1 (forced expiratory volume in 1 second) by an average of 3-5% in CF patients homozygous for the F508del-CFTR mutation. We propose that P. aeruginosa infection of CF lungs reduces VX-809 + VX-770- stimulated F508del-CFTR Cl secretion, and thereby reduces the clinical efficacy of VX-809 + VX-770. Methods and Results F508del-CFBE cells and primary cultures of CF-HBE cells (F508del/F508del) were exposed to VX-809 alone or a combination of VX-809 + VX-770 for 48 hours and the effect of P. aeruginosa on F508del-CFTR Cl secretion was measured in Ussing chambers. The effect of VX-809 on F508del-CFTR abundance was measured by cell surface biotinylation and western blot analysis. PAO1, PA14, PAK and 6 clinical isolates of P. aeruginosa (3 mucoid and 3 non-mucoid) significantly reduced drug stimulated F508del-CFTR Cl secretion, and plasma membrane F508del-CFTR. Conclusion The observation that P. aeruginosa reduces VX-809 and VX-809 + VX-770 stimulated F508del CFTR Cl secretion may explain, in part, why VX-809 + VX-770 has modest efficacy in clinical trials. PMID:26018799

  13. Cultured human airway epithelial cells (calu-3): a model of human respiratory function, structure, and inflammatory responses.

    PubMed

    Zhu, Yan; Chidekel, Aaron; Shaffer, Thomas H

    2010-01-01

    This article reviews the application of the human airway Calu-3 cell line as a respiratory model for studying the effects of gas concentrations, exposure time, biophysical stress, and biological agents on human airway epithelial cells. Calu-3 cells are grown to confluence at an air-liquid interface on permeable supports. To model human respiratory conditions and treatment modalities, monolayers are placed in an environmental chamber, and exposed to specific levels of oxygen or other therapeutic modalities such as positive pressure and medications to assess the effect of interventions on inflammatory mediators, immunologic proteins, and antibacterial outcomes. Monolayer integrity and permeability and cell histology and viability also measure cellular response to therapeutic interventions. Calu-3 cells exposed to graded oxygen concentrations demonstrate cell dysfunction and inflammation in a dose-dependent manner. Modeling positive airway pressure reveals that pressure may exert a greater injurious effect and cytokine response than oxygen. In experiments with pharmacological agents, Lucinactant is protective of Calu-3 cells compared with Beractant and control, and perfluorocarbons also protect against hyperoxia-induced airway epithelial cell injury. The Calu-3 cell preparation is a sensitive and efficient preclinical model to study human respiratory processes and diseases related to oxygen- and ventilator-induced lung injury. PMID:20948883

  14. Rhinovirus-Induced Airway Disease: A Model to Understand the Antiviral and Th2 Epithelial Immune Dysregulation in Childhood Asthma

    PubMed Central

    Perez, Geovanny F.; Rodriguez-Martinez, Carlos E.; Nino, Gustavo

    2015-01-01

    Rhinovirus (RV) infections account for most asthma exacerbations among children and adults, yet the fundamental mechanism responsible for why asthmatics are more susceptible to RV than otherwise healthy individuals remains largely unknown. Nonetheless, the use of models to understand the mechanisms of RV-induced airway disease in asthma has dramatically expanded our knowledge about the cellular and molecular pathogenesis of the disease. For instance, ground-breaking studies have recently established that the susceptibility to RV in asthmatic subjects is associated with a dysfunctional airway epithelial inflammatory response generated after innate recognition of viral-related molecules, such as double stranded (ds) RNA. This review summarizes the novel cardinal features of the asthmatic condition identified in the past few years through translational and experimental RV-based approaches. Specifically, we discuss the evidence demonstrating the presence of an abnormal innate antiviral immunity (airway epithelial secretion of type I and III interferons), exaggerated production of the master Th2 molecule thymic stromal lymphopoietin (TSLP), and altered antimicrobial host defense in the airways of asthmatic individuals with acute RV infection. PMID:26057561

  15. Arylhydrocarbon receptor (AhR) activation in airway epithelial cells induces MUC5AC via reactive oxygen species (ROS) production.

    PubMed

    Chiba, Takahito; Uchi, Hiroshi; Tsuji, Gaku; Gondo, Hisaki; Moroi, Yoichi; Furue, Masutaka

    2011-02-01

    The dioxins and dioxin-like compounds in cigarette smoke regulate various immunological responses via the arylhydrocarbon receptor (AhR). These environmental toxicants are known to cause bronchitis, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Recent studies have demonstrated that AhR activation upregulates the expression of mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) in the airway epithelial cell line. However, the mechanism for the production of mucin has not been clarified. In this study, we investigated the role and pathway of AhR in airway epithelial cells by using selective agonists and antagonists. After stimulation with or without benzopyrene (B[a]P), an AhR agonist, MUC5AC expression was measured by real-time RT-PCR. The mechanism of AhR-induced MUC5AC expression in airway epithelial cells was studied in terms of the production of cytokine and reactive oxygen species (ROS). Treatment with B[a]P increased ROS generation in NCI-H₂₉₂ cells. Furthermore, B[a]P-induced MUC5AC upregulation and mucin production were inhibited by AhR siRNA or the use of an antioxidative agent. These results suggest that the AhR-induced increase of mucin production is partially mediated by ROS generation. An antioxidant therapy approach may help to cure AhR-induced mucus hypersecretory diseases. PMID:20709182

  16. Regulation of normal and cystic fibrosis airway surface liquid volume by phasic shear stress.

    PubMed

    Tarran, Robert; Button, Brian; Boucher, Richard C

    2006-01-01

    The physical removal of viruses and bacteria on the mucociliary escalator is an important aspect of the mammalian lung's innate defense mechanism. The volume of airway surface liquid (ASL) present in the respiratory tract is a critical determinant of both mucus hydration and the rate of mucus clearance from the lung. ASL volume is maintained by the predominantly ciliated epithelium via coordinated regulation of (a) absorption, by the epithelial Na+ channel, and (b) secretion, by the Ca2+-activated Cl- channel (CaCC) and CFTR. This review provides an update on our current understanding of how shear stress regulates ASL volume height in normal and cystic fibrosis (CF) airway epithelia through extracellular ATP- and adenosine (ADO)-mediated pathways that modulate ion transport and ASL volume homeostasis. We also discuss (a) how derangement of the ADO-CFTR pathway renders CF airways vulnerable to viral infections that deplete ASL volume and produce mucus stasis, and (b) potential shear stress-dependent therapies for CF. PMID:16460283

  17. Airway epithelial cell PPARγ modulates cigarette smoke-induced chemokine expression and emphysema susceptibility in mice.

    PubMed

    Solleti, Siva Kumar; Simon, Dawn M; Srisuma, Sorachai; Arikan, Meltem C; Bhattacharya, Soumyaroop; Rangasamy, Tirumalai; Bijli, Kaiser M; Rahman, Arshad; Crossno, Joseph T; Shapiro, Steven D; Mariani, Thomas J

    2015-08-01

    Chronic obstructive pulmonary disease (COPD) is a highly prevalent, chronic inflammatory lung disease with limited existing therapeutic options. While modulation of peroxisome proliferator-activating receptor (PPAR)-γ activity can modify inflammatory responses in several models of lung injury, the relevance of the PPARG pathway in COPD pathogenesis has not been previously explored. Mice lacking Pparg specifically in airway epithelial cells displayed increased susceptibility to chronic cigarette smoke (CS)-induced emphysema, with excessive macrophage accumulation associated with increased expression of chemokines, Ccl5, Cxcl10, and Cxcl15. Conversely, treatment of mice with a pharmacological PPARγ activator attenuated Cxcl10 and Cxcl15 expression and macrophage accumulation in response to CS. In vitro, CS increased lung epithelial cell chemokine expression in a PPARγ activation-dependent fashion. The ability of PPARγ to regulate CS-induced chemokine expression in vitro was not specifically associated with peroxisome proliferator response element (PPRE)-mediated transactivation activity but was correlated with PPARγ-mediated transrepression of NF-κB activity. Pharmacological or genetic activation of PPARγ activity abrogated CS-dependent induction of NF-κB activity. Regulation of NF-κB activity involved direct PPARγ-NF-κB interaction and PPARγ-mediated effects on IKK activation, IκBα degradation, and nuclear translocation of p65. Our data indicate that PPARG represents a disease-relevant pathophysiological and pharmacological target in COPD. Its activation state likely contributes to NF-κB-dependent, CS-induced chemokine-mediated regulation of inflammatory cell accumulation. PMID:26024894

  18. Intranasal Immunization Strategy To Impede Pilin-Mediated Binding of Pseudomonas aeruginosa to Airway Epithelial Cells

    PubMed Central

    Hsieh, Jennifer C.; Tham, Doris M.; Feng, Weijun; Huang, Fan; Embaie, Selamawit; Liu, Keyi; Dean, Deborah; Hertle, Ralf; FitzGerald, David J.; Mrsny, Randall J.

    2005-01-01

    Prevention of pulmonary Pseudomonas aeruginosa infections represents a critical unmet medical need for cystic fibrosis (CF) patients. We have examined the tenet that a mucosal immunization approach can reduce interactions of a piliated form of this opportunistic pathogen with respiratory epithelial cells. Vaccinations were performed using ntPEpilinPAK, a protein chimera composed of a nontoxic form of P. aeruginosa exotoxin A (ntPE), where the C-terminal loop amino acid sequence of the PAK strain pilin protein was inserted in place of the ntPE Ib domain. Intranasal (i.n.) immunization of BALB/c mice with ntPEpilinPAK generated both serum and saliva immune responses. A series of in vitro studies showed that diluted samples of saliva obtained from immunized mice reduced pilin-dependent P. aeruginosa binding to polarized human tracheal epithelial cells, protected human pulmonary epithelial cells from cytotoxic actions associated with bacterial challenge, and reduced exotoxin A toxicity. Overall, i.n. administration of ntPEpilinPAK induced mucosal and systemic immune responses that may be beneficial for blocking early stage adhesion and/or infection events of epithelial cell-P. aeruginosa interactions at oropharyngeal surfaces. PMID:16239575

  19. A Selective Irreversible Inhibitor of Furin Does Not Prevent Pseudomonas Aeruginosa Exotoxin A-Induced Airway Epithelial Cytotoxicity

    PubMed Central

    Walker, Brian; Hamilton, Robert A.; Martin, S. Lorraine

    2016-01-01

    Many bacterial and viral pathogens (or their toxins), including Pseudomonas aeruginosa exotoxin A, require processing by host pro-protein convertases such as furin to cause disease. We report the development of a novel irreversible inhibitor of furin (QUB-F1) consisting of a diphenyl phosphonate electrophilic warhead coupled with a substrate-like peptide (RVKR), that also includes a biotin tag, to facilitate activity-based profiling/visualisation. QUB-F1 displays greater selectivity for furin, in comparison to a widely used exemplar compound (furin I) which has a chloromethylketone warhead coupled to RVKR, when tested against the serine trypsin-like proteases (trypsin, prostasin and matriptase), factor Xa and the cysteine protease cathepsin B. We demonstrate QUB-F1 does not prevent P. aeruginosa exotoxin A-induced airway epithelial cell toxicity; in contrast to furin I, despite inhibiting cell surface furin-like activity to a similar degree. This finding indicates additional proteases, which are sensitive to the more broad-spectrum furin I compound, may be involved in this process. PMID:27459298

  20. Mitochondrial alteration in malignantly transformed human small airway epithelial cells induced by alpha particles

    PubMed Central

    Zhang, Suping; Wen, Gengyun; Huang, Sarah XL; Wang, Jianrong; Tong, Jian; Hei, Tom K.

    2012-01-01

    Human small airway epithelial cells (SAECs) immortalized with human telomerase reverse transcriptase (h-TERT) were exposed to either a single or multiple doses of α particles. Irradiated cells showed a dose-dependent cytotoxicity and progressive neoplastic transformation phenotype. These included an increase in saturation density of growth, a greater resistance to PALA, faster anchorage-independent growth, reinforced cell invasion and c-Myc expression. In addition, the transformed cells formed progressively growing tumors upon inoculation into athymic nude mice. Specifically, α-irradiation induced damage to both mitochondrial DNA (mtDNA) and mitochondrial functions in transformed cells as evidenced by increased mtDNA copy number and common deletion, decreased oxidative phosphorylation (OXPHOS) activity as measured by cytochrome C oxidase (COX) activity and oxygen consumption. There was a linear correlation between mtDNA copy number, common deletion, COX activity and cellular transformation represented by soft agar colony formation and c-Myc expression. These results suggest that mitochondria are associated with neoplastic transformation of SAEC cells induced by α particles, and that the oncogenesis process may depend not only on the genomes inside the nucleus, but also on the mitochondrial DNA outside the nucleus. PMID:22644783

  1. Primary Paediatric Bronchial Airway Epithelial Cell in Vitro Responses to Environmental Exposures

    PubMed Central

    McInnes, Neil; Davidson, Matthew; Scaife, Alison; Miller, David; Spiteri, Daniella; Engelhardt, Tom; Semple, Sean; Devereux, Graham; Walsh, Garry; Turner, Steve

    2016-01-01

    The bronchial airway epithelial cell (BAEC) is the site for initial encounters between inhaled environmental factors and the lower respiratory system. Our hypothesis was that release of pro inflammatory interleukins (IL)-6 and IL-8 from primary BAEC cultured from children will be increased after in vitro exposure to common environmental factors. Primary BAEC were obtained from children undergoing clinically indicated routine general anaesthetic procedures. Cells were exposed to three different concentrations of lipopolysaccharide (LPS) or house dust mite allergen (HDM) or particulates extracted from side stream cigarette smoke (SSCS). BAEC were obtained from 24 children (mean age 7.0 years) and exposed to stimuli. Compared with the negative control, there was an increase in IL-6 and IL-8 release after exposure to HDM (p ≤ 0.001 for both comparisons). There was reduced IL-6 after higher compared to lower SSCS exposure (p = 0.023). There was no change in BAEC release of IL-6 or IL-8 after LPS exposure. BAEC from children are able to recognise and respond in vitro with enhanced pro inflammatory mediator secretion to some inhaled exposures. PMID:27023576

  2. Epigenetic dysregulation of interleukin 8 (CXCL8) hypersecretion in cystic fibrosis airway epithelial cells.

    PubMed

    Poghosyan, Anna; Patel, Jamie K; Clifford, Rachel L; Knox, Alan J

    2016-08-01

    Airway epithelial cells in cystic fibrosis (CF) overexpress Interleukin 8 (CXCL8) through poorly defined mechanisms. CXCL8 transcription is dependent on coordinated binding of CCAAT/enhancer binding protein (C/EBP)β, nuclear factor (NF)-κB, and activator protein (AP)-1 to the promoter. Here we show abnormal epigenetic regulation is responsible for CXCL8 overexpression in CF cells. Under basal conditions CF cells had increased bromodomain (Brd)3 and Brd4 recruitment and enhanced NF-κB and C/EBPβ binding to the CXCL8 promoter compared to non-CF cells due to trimethylation of histone H3 at lysine 4 (H3K4me3) and DNA hypomethylation at CpG6. IL-1β increased NF-κB, C/EBPβ and Brd4 binding. Furthermore, inhibitors of bromodomain and extra-terminal domain family (BET) proteins reduced CXCL8 production in CF cells suggesting a therapeutic target for the BET pathway. PMID:27240956

  3. Establishment and transformation of telomerase-immortalized human small airway epithelial cells by heavy ions

    NASA Astrophysics Data System (ADS)

    Zhao, Y. L.; Piao, C. Q.; Hei, T. K.

    Previous studies from this laboratory have identified a number of causally linked genes including the novel tumor suppressor Betaig-h3 that were differentially expressed in radiation induced tumorigenic BEP2D cells. To extend these studies using a genomically more stable bronchial cell line, we show here that ectopic expression of the catalytic subunit of telomerase (hTERT) in primary human small airway epithelial (SAE) cells resulted in the generation of several clonal cell lines that have been continuously in culture for more than 250 population doublings and are considered immortal. Comparably-treated control SAE cells infected with only the viral vector senesced after less than 10 population doublings. The immortalized clones demonstrated anchorage dependent growth and are non-tumorigenic in nude mice. These cells show no alteration in the p53 gene but a decrease in p16 expression. Exponentially growing SAEh cells were exposed to graded doses of 1 GeV/nucleon of 56Fe ions accelerated at the Brookhaven National Laboratory. Irradiated cells underwent gradual phenotypic alterations after extensive in vitro cultivation. Transformed cells developed through a series of successive steps before becoming anchorage independent in semisolid medium. These findings indicate that hTERT-immortalized cells, being diploid and chromosomal stable, should be a useful model in assessing mechanism of radiation carcinogenesis.

  4. Involvement of Syk kinase in TNF-induced nitric oxide production by airway epithelial cells

    SciTech Connect

    Ulanova, Marina . E-mail: marina.ulanova@normed.ca; Marcet-Palacios, Marcelo; Munoz, Samira; Asfaha, Samuel; Kim, Moo-Kyung; Schreiber, Alan D.; Befus, A. Dean

    2006-12-15

    We have recently found that Syk is widely expressed in lung epithelial cells (EC) and participates in {beta}1 integrin signaling. In this study, we assessed the role of Syk in regulation of NO production. Stimulation of human bronchial EC line HS-24 by TNF caused an increased expression of inducible nitric oxide synthase (iNOS). Inhibition of Syk using siRNA or piceatannol down-regulated the iNOS expression and reduced NO production. This effect occurred in EC simultaneously stimulated via {beta}1 integrins, suggesting that TNF and {beta}1 integrins provide co-stimulatory signals. Inhibition of Syk down-regulated TNF-induced p38 and p44/42 MAPK phosphorylation and nuclear translocation of p65 NF-{kappa}B. Thus, TNF-induced activation of pro-inflammatory signaling in EC leading to enhanced expression of iNOS and NO production was dependent on Syk. Syk-mediated signaling regulates NO production at least partly via activating the MAPK cascade. Understanding the role of Syk in airway EC may help in developing new therapeutic tools for inflammatory lung disorders.

  5. 4-hydroxynonenal regulates mitochondrial function in human small airway epithelial cells.

    PubMed

    Galam, Lakshmi; Failla, Athena; Soundararajan, Ramani; Lockey, Richard F; Kolliputi, Narasaiah

    2015-12-01

    Prolonged exposure to oxidative stress causes Acute Lung Injury (ALI) and significantly impairs pulmonary function. Previously we have demonstrated that mitochondrial dysfunction is a key pathological factor in hyperoxic ALI. While it is known that hyperoxia induces the production of stable, but toxic 4-hydroxynonenal (4-HNE) molecule, it is unknown how the reactive aldehyde disrupts mitochondrial function. Our previous in vivo study indicated that exposure to hyperoxia significantly increases 4-HNE-Protein adducts, as well as levels of MDA in total lung homogenates. Based on the in vivo studies, we explored the effects of 4-HNE in human small airway epithelial cells (SAECs). Human SAECs treated with 25 μM of 4-HNE showed a significant decrease in cellular viability and increased caspase-3 activity. Moreover, 4-HNE treated SAECs showed impaired mitochondrial function and energy production indicated by reduced ATP levels, mitochondrial membrane potential, and aconitase activity. This was followed by a significant decrease in mitochondrial oxygen consumption and depletion of the reserve capacity. The direct effect of 4-HNE on the mitochondrial respiratory chain was confirmed using Rotenone. Furthermore, SAECs treated with 25 μM 4-HNE showed a time-dependent depletion of total Thioredoxin (Trx) proteins and Trx activity. Taken together, our results indicate that 4-HNE induces cellular and mitochondrial dysfunction in human SAECs, leading to an impaired endogenous antioxidant response. PMID:26484418

  6. Primary Paediatric Bronchial Airway Epithelial Cell in Vitro Responses to Environmental Exposures.

    PubMed

    McInnes, Neil; Davidson, Matthew; Scaife, Alison; Miller, David; Spiteri, Daniella; Engelhardt, Tom; Semple, Sean; Devereux, Graham; Walsh, Garry; Turner, Steve

    2016-01-01

    The bronchial airway epithelial cell (BAEC) is the site for initial encounters between inhaled environmental factors and the lower respiratory system. Our hypothesis was that release of pro inflammatory interleukins (IL)-6 and IL-8 from primary BAEC cultured from children will be increased after in vitro exposure to common environmental factors. Primary BAEC were obtained from children undergoing clinically indicated routine general anaesthetic procedures. Cells were exposed to three different concentrations of lipopolysaccharide (LPS) or house dust mite allergen (HDM) or particulates extracted from side stream cigarette smoke (SSCS). BAEC were obtained from 24 children (mean age 7.0 years) and exposed to stimuli. Compared with the negative control, there was an increase in IL-6 and IL-8 release after exposure to HDM (p ≤ 0.001 for both comparisons). There was reduced IL-6 after higher compared to lower SSCS exposure (p = 0.023). There was no change in BAEC release of IL-6 or IL-8 after LPS exposure. BAEC from children are able to recognise and respond in vitro with enhanced pro inflammatory mediator secretion to some inhaled exposures. PMID:27023576

  7. Respiratory Syncytial Virus Uses CX3CR1 as a Receptor on Primary Human Airway Epithelial Cultures

    PubMed Central

    Johnson, Sara M.; McNally, Beth A.; Ioannidis, Ioannis; Flano, Emilio; Teng, Michael N.; Oomens, Antonius G.; Walsh, Edward E.; Peeples, Mark E.

    2015-01-01

    Respiratory syncytial virus (RSV) is the most frequent cause of lower respiratory disease in infants, but no vaccine or effective therapy is available. The initiation of RSV infection of immortalized cells is largely dependent on cell surface heparan sulfate (HS), a receptor for the RSV attachment (G) glycoprotein in immortalized cells. However, RSV infects the ciliated cells in primary well differentiated human airway epithelial (HAE) cultures via the apical surface, but HS is not detectable on this surface. Here we show that soluble HS inhibits infection of immortalized cells, but not HAE cultures, confirming that HS is not the receptor on HAE cultures. Conversely, a “non-neutralizing” monoclonal antibody against the G protein that does not block RSV infection of immortalized cells, does inhibit infection of HAE cultures. This antibody was previously shown to block the interaction between the G protein and the chemokine receptor CX3CR1 and we have mapped the binding site for this antibody to the CX3C motif and its surrounding region in the G protein. We show that CX3CR1 is present on the apical surface of ciliated cells in HAE cultures and especially on the cilia. RSV infection of HAE cultures is reduced by an antibody against CX3CR1 and by mutations in the G protein CX3C motif. Additionally, mice lacking CX3CR1 are less susceptible to RSV infection. These findings demonstrate that RSV uses CX3CR1 as a cellular receptor on HAE cultures and highlight the importance of using a physiologically relevant model to study virus entry and antibody neutralization. PMID:26658574

  8. Respiratory Syncytial Virus Uses CX3CR1 as a Receptor on Primary Human Airway Epithelial Cultures.

    PubMed

    Johnson, Sara M; McNally, Beth A; Ioannidis, Ioannis; Flano, Emilio; Teng, Michael N; Oomens, Antonius G; Walsh, Edward E; Peeples, Mark E

    2015-12-01

    Respiratory syncytial virus (RSV) is the most frequent cause of lower respiratory disease in infants, but no vaccine or effective therapy is available. The initiation of RSV infection of immortalized cells is largely dependent on cell surface heparan sulfate (HS), a receptor for the RSV attachment (G) glycoprotein in immortalized cells. However, RSV infects the ciliated cells in primary well differentiated human airway epithelial (HAE) cultures via the apical surface, but HS is not detectable on this surface. Here we show that soluble HS inhibits infection of immortalized cells, but not HAE cultures, confirming that HS is not the receptor on HAE cultures. Conversely, a "non-neutralizing" monoclonal antibody against the G protein that does not block RSV infection of immortalized cells, does inhibit infection of HAE cultures. This antibody was previously shown to block the interaction between the G protein and the chemokine receptor CX3CR1 and we have mapped the binding site for this antibody to the CX3C motif and its surrounding region in the G protein. We show that CX3CR1 is present on the apical surface of ciliated cells in HAE cultures and especially on the cilia. RSV infection of HAE cultures is reduced by an antibody against CX3CR1 and by mutations in the G protein CX3C motif. Additionally, mice lacking CX3CR1 are less susceptible to RSV infection. These findings demonstrate that RSV uses CX3CR1 as a cellular receptor on HAE cultures and highlight the importance of using a physiologically relevant model to study virus entry and antibody neutralization. PMID:26658574

  9. Regulation of high glucose-mediated mucin expression by matrix metalloproteinase-9 in human airway epithelial cells.

    PubMed

    Yu, Hongmei; Yang, Juan; Xiao, Qian; Lü, Yang; Zhou, Xiangdong; Xia, Li; Nie, Daijing

    2015-04-10

    Mucus hypersecretion is the key manifestation in patients with chronic inflammatory airway diseases and mucin 5AC (MUC5AC) is a major component of airway mucus. Matrix metalloproteinases (MMP)-9, have been found to be involved in the pathogenesis of inflammatory airway diseases. Hyperglycemia has been shown to be an independent risk factor for respiratory infections. We hypothesize that high glucose (HG)-regulates MMP-9 production and MMP-9 activity through nicotinamide adenine dinucleotide phosphate (NADPH)/reactive oxygen species (ROS) cascades pathways, leading to mucin production in human airway epithelial cells (16HBE). We show that HG increases MMP-9 production, MMP-9 activity and MUC5AC expression. These effects are prevented by small interfering RNA (siRNA) for MMP-9, indicating that HG-induced mucin production is MMP-9-dependent. HG activates MMP-9 production, MMP-9 activity and MUC5AC overproduction, which is inhibited by nPG, DMSO and DPI (inhibitors of ROS and NADPH), suggesting that HG-activated mucin synthesis is mediated by NADPH/ROS in 16HBE cells. These observations demonstrate an important role for MMP-9 activated by NADPH/ROS signaling pathways in regulating HG-induced MUC5AC expression. These findings may bring new insights into the molecular pathogenesis of the infections related to diabetes mellitus and lead to novel therapeutic intervention for mucin overproduction in chronic inflammatory airway diseases. PMID:25704757

  10. Polyinosinic:polycytidylic acid induces protein kinase D–dependent disassembly of apical junctions and barrier dysfunction in airway epithelial cells

    PubMed Central

    Rezaee, Fariba; Meednu, Nida; Emo, Jason A.; Saatian, Bahman; Chapman, Timothy J.; Naydenov, Nayden G.; De Benedetto, Anna; Beck, Lisa A.; Ivanov, Andrei I.; Georas, Steve N.

    2011-01-01

    Background Disruption of the epithelial barrier might be a risk factor for allergen sensitization and asthma. Viral respiratory tract infections are strongly associated with asthma exacerbation, but the effects of respiratory viruses on airway epithelial barrier function are not well understood. Many viruses generate double-stranded RNA, which can lead to airway inflammation and initiate an antiviral immune response. Objectives We investigated the effects of the synthetic double-stranded RNA polyinosinic:polycytidylic acid (polyI:C) on the structure and function of the airway epithelial barrier in vitro. Methods 16HBE14o- human bronchial epithelial cells and primary airway epithelial cells at an air-liquid interface were grown to confluence on Transwell inserts and exposed to polyI:C. We studied epithelial barrier function by measuring transepithelial electrical resistance and paracellular flux of fluorescent markers and structure of epithelial apical junctions by means of immunofluorescence microscopy. Results PolyI:C induced a profound decrease in transepithelial electrical resistance and increase in paracellular permeability. Immunofluorescence microscopy revealed markedly reduced junctional localization of zonula occludens-1, occludin, E-cadherin, β-catenin, and disorganization of junction-associated actin filaments. PolyI:C induced protein kinase D (PKD) phosphorylation, and a PKD antagonist attenuated polyI:C-induced disassembly of apical junctions and barrier dysfunction. Conclusions PolyI:C has a powerful and previously unsuspected disruptive effect on the airway epithelial barrier. PolyI:C-dependent barrier disruption is mediated by disassembly of epithelial apical junctions, which is dependent on PKD signaling. These findings suggest a new mechanism potentially underlying the associations between viral respiratory tract infections, airway inflammation, and allergen sensitization. PMID:21996340

  11. Resveratrol Enhances Airway Surface Liquid Depth in Sinonasal Epithelium by Increasing Cystic Fibrosis Transmembrane Conductance Regulator Open Probability

    PubMed Central

    Zhang, Shaoyan; Blount, Angela C.; McNicholas, Carmel M.; Skinner, Daniel F.; Chestnut, Michael; Kappes, John C.; Sorscher, Eric J.; Woodworth, Bradford A.

    2013-01-01

    Background Chronic rhinosinusitis engenders enormous morbidity in the general population, and is often refractory to medical intervention. Compounds that augment mucociliary clearance in airway epithelia represent a novel treatment strategy for diseases of mucus stasis. A dominant fluid and electrolyte secretory pathway in the nasal airways is governed by the cystic fibrosis transmembrane conductance regulator (CFTR). The objectives of the present study were to test resveratrol, a strong potentiator of CFTR channel open probability, in preparation for a clinical trial of mucociliary activators in human sinus disease. Methods Primary sinonasal epithelial cells, immortalized bronchoepithelial cells (wild type and F508del CFTR), and HEK293 cells expressing exogenous human CFTR were investigated by Ussing chamber as well as patch clamp technique under non-phosphorylating conditions. Effects on airway surface liquid depth were measured using confocal laser scanning microscopy. Impact on CFTR gene expression was measured by quantitative reverse transcriptase polymerase chain reaction. Results Resveratrol is a robust CFTR channel potentiator in numerous mammalian species. The compound also activated temperature corrected F508del CFTR and enhanced CFTR-dependent chloride secretion in human sinus epithelium ex vivo to an extent comparable to the recently approved CFTR potentiator, ivacaftor. Using inside out patches from apical membranes of murine cells, resveratrol stimulated an ~8 picosiemens chloride channel consistent with CFTR. This observation was confirmed in HEK293 cells expressing exogenous CFTR. Treatment of sinonasal epithelium resulted in a significant increase in airway surface liquid depth (in µm: 8.08+/-1.68 vs. 6.11+/-0.47,control,p<0.05). There was no increase CFTR mRNA. Conclusion Resveratrol is a potent chloride secretagogue from the mucosal surface of sinonasal epithelium, and hydrates airway surface liquid by increasing CFTR channel open probability

  12. Bile acids stimulate chloride secretion through CFTR and calcium-activated Cl- channels in Calu-3 airway epithelial cells.

    PubMed

    Hendrick, Siobhán M; Mroz, Magdalena S; Greene, Catherine M; Keely, Stephen J; Harvey, Brian J

    2014-09-01

    Bile acids resulting from the aspiration of gastroesophageal refluxate are often present in the lower airways of people with cystic fibrosis and other respiratory distress diseases. Surprisingly, there is little or no information on the modulation of airway epithelial ion transport by bile acids. The secretory effect of a variety of conjugated and unconjugated secondary bile acids was investigated in Calu-3 airway epithelial cells grown under an air-liquid interface and mounted in Ussing chambers. Electrogenic transepithelial ion transport was measured as short-circuit current (Isc). The taurine-conjugated secondary bile acid, taurodeoxycholic acid (TDCA), was found to be the most potent modulator of basal ion transport. Acute treatment (5 min) of Calu-3 cells with TDCA (25 μM) on the basolateral side caused a stimulation of Isc, and removal of extracellular Cl(-) abolished this response. TDCA produced an increase in the cystic fibrosis transmembrane conductance regulator (CFTR)-dependent current that was abolished by pretreatment with the CFTR inhibitor CFTRinh172. TDCA treatment also increased Cl(-) secretion through calcium-activated chloride (CaCC) channels and increased the Na(+)/K(+) pump current. Acute treatment with TDCA resulted in a rapid cellular influx of Ca(2+) and increased cAMP levels in Calu-3 cells. Bile acid receptor-selective activation with INT-777 revealed TGR5 localized at the basolateral membrane as the receptor involved in TDCA-induced Cl(-) secretion. In summary, we demonstrate for the first time that low concentrations of bile acids can modulate Cl(-) secretion in airway epithelial cells, and this effect is dependent on both the duration and sidedness of exposure to the bile acid. PMID:24993131

  13. Effects of air pollution-related heavy metals on the viability and inflammatory responses of human airway epithelial cells.

    PubMed

    Honda, Akiko; Tsuji, Kenshi; Matsuda, Yugo; Hayashi, Tomohiro; Fukushima, Wataru; Sawahara, Takahiro; Kudo, Hitomi; Murayama, Rumiko; Takano, Hirohisa

    2015-01-01

    Various metals produced from human activity are ubiquitously detected in ambient air. The metals may lead to induction and/or exacerbation of respiratory diseases, but the significant metals and factors contributing to such diseases have not been identified. To compare the effects of each metal and different oxidation states of metals on human airway, we examined the viability and production of interleukin (IL)-6 and IL-8 using BEAS-2B cell line, derived from human airway epithelial cells. Airway epithelial cells were exposed to Mn(2+), V(4+), V(5+), Cr(3+), Cr(6+), Zn(2+), Ni(2+), and Pb(2+) at a concentration of 0.5, 5, 50, or 500 μmol/L for 24 hours. Mn and V decreased the cell viability in a concentration-dependent manner, and V(5+) tended to have a greater effect than V(4+). The Cr decreased the cell viability, and (Cr(+6)) at concentrations of 50 and 500 μmol/L was more toxic than (Cr(+3)). Zn at a concentration of 500 μmol/L greatly decreased the cell viability, whereas Ni at the same concentration increased it. Pb produced fewer changes. Mn and Ni at a concentration of 500 μmol/L induced the significant production of IL-6 and IL-8. However, most of the metals including (V(+4), V(+5)), (Cr(+3), Cr(+6)), Zn, and Pb inhibited the production of both IL-6 and IL-8. The present results indicate that various heavy metals have different effects on toxicity and the proinflammatory responses of airway epithelial cells, and those influences also depend on the oxidation states of the metals. PMID:25808165

  14. Interaction and Localization of Synthetic Nanoparticles in Healthy and Cystic Fibrosis Airway Epithelial Cells: Effect of Ozone Exposure

    PubMed Central

    Raemy, David O.; Loader, Joan E.; Kailey, Jenai M; Neeves, Keith B.; White, Carl W.; Ahmad, Aftab; Gehr, Peter; Rothen-Rutishauser, Barbara M.

    2012-01-01

    Abstract Background Nanoparticles (NPs) produced by nanotechnology processes have taken the field of medicine by storm. Concerns about safety of these NPs in humans, however, have recently been raised. Although studies of NP toxicity have focused on lung disease the mechanistic link between NP exposure and lung injury remained unclear. This is primarily due to a lack of availability of appropriate airway disease models and sophisticated microscopic techniques to study nano-sized particulate delivery and resulting responses. Methods Air–liquid interface (ALI) cultures of non-cystic fibrosis (CF) and CF airway epithelial cells were exposed to the FITC-labeled NPs using a PennCentury microsprayer™. Uptake of NPs was assessed by FACS. Laser scanning microscopy (LSM) was performed and the images were analyzed by an advanced imaging software to study particle deposition and uptake. Results Flow cytometry data revealed that CF cells accumulated increased amounts of NPs. The increased NP uptake could be attributed to the reduced CF transmembrane conductance regulator (CFTR) function as a similar increased retention/uptake was observed in cells whose CFTR expression was downregulated by antisense oligonucleotide. NPs alone did not induce pro-inflammatory cytokine release or cell death. The cell culture system was sensitive to ozone but exposure to the uncoated synthetic NPs used in this study, did not cause any synergistic or suppressive effects. LSM imaging and subsequent image restoration further indicated particle uptake and intracellular localization. Exposure to ozone increased nuclear uptake in both non-CF and CF cells. Conclusion Our findings demonstrate the uptake of NPs using ALI cultures of non-CF and CF airway epithelial cells. The NPs used here were useful in demonstrating uptake by airway epithelial cells without causing adverse effects in presence or absence of ozone. However, to totally exclude toxic effects, chronic studies under in vivo conditions using

  15. Reduction of DNA mismatch repair protein expression in airway epithelial cells of premenopausal women chronically exposed to biomass smoke.

    PubMed

    Mukherjee, Bidisha; Dutta, Anindita; Chowdhury, Saswati; Roychoudhury, Sanghita; Ray, Manas Ranjan

    2014-02-01

    Biomass burning is a major source of indoor air pollution in rural India. This study examined whether chronic inhalation of biomass smoke causes change in the DNA mismatch repair (MMR) pathway in the airway cells. For this, airway cells exfoliated in sputum were collected from 72 premenopausal nonsmoking rural women (median age 34 years) who cooked with biomass (wood, dung, crop residues) and 68 control women who cooked with cleaner fuel liquefied petroleum gas (LPG) for the past 5 years or more. The levels of particulate matters with diameters less than 10 and 2.5 μm (PM10 and PM2.5) in indoor air were measured by real-time aerosol monitor. Benzene exposure was monitored by measuring trans,trans-muconic acid (t,t-MA) in urine by high-performance liquid chromatography with ultraviolet detector. Generation of reactive oxygen species (ROS) and level of superoxide dismutase (SOD) in airway cells were measured by flow cytometry and spectrophotometry, respectively. Immunocytochemical assay revealed lower percentage of airway epithelial cells expressing MMR proteins mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) in biomass-using women compared to LPG-using controls. Women who cooked with biomass had 6.7 times higher level of urinary t,t-MA, twofold increase in ROS generation, and 31 % depletion of SOD. Indoor air of biomass-using households had three times more particulate matters than that of controls. ROS, urinary t,t-MA, and particulate pollution in biomass-using kitchen had negative correlation, while SOD showed positive correlation with MSH2 and MLH1 expression. It appears that chronic exposure to biomass smoke reduces MMR response in airway epithelial cells, and oxidative stress plays an important role in the process. PMID:24146321

  16. Expression of RANTES in human airway epithelial cells: effect of corticosteroids and interleukin-4, -10 and -13.

    PubMed Central

    Berkman, N; Robichaud, A; Krishnan, V L; Roesems, G; Robbins, R; Jose, P J; Barnes, P J; Chung, K F

    1996-01-01

    RANTES is a C-C chemokine with strong chemoattractant and activating properties for eosinophils, basophils and T lymphocytes. We investigated the expression of RANTES in human airway epithelial cells and its modulation. Epithelial cells obtained from tracheas of donor lungs were stimulated with interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) or with a mixture of the three cytokines ('cytomix'). Levels of mRNA and protein were assayed by Northern blot and radioimmunoassay, respectively. Each individual cytokine produced a small increase in RANTES protein: IL-1 beta 24 +/- 1 pM, TNF-alpha 13 +/- 7 pM and IFN-gamma 29 +/- 7 pM, but cytomix increased protein to 236 +/- 22 pM (P < 0.002) and mRNA expression by > 20-fold (P < 0.002). Both RANTES protein and mRNA expression were inhibited by dexamethasone (10(-6) M) (38 +/- 5%, P < 0.05 and 55 +/- 8%, P < 0.007, respectively), and by IL-4 (42 +/- 7%, P < 0.03 and 19 +/- 1%, not significant, respectively). No inhibitory effect was observed with IL-10 or IL-13. We also demonstrated in vivo expression of RANTES protein by epithelial cells in human airways using immunohistochemistry. Our data show that human airway epithelial cells can be stimulated to express and release RANTES, an effect that is inhibited by corticosteroids and IL-4, but not by IL-10 and IL-13. Images Figure 1 Figure 2 Figure 3 PMID:8675215

  17. Inhibitors of pendrin anion exchange identified in a small molecule screen increase airway surface liquid volume in cystic fibrosis.

    PubMed

    Haggie, Peter M; Phuan, Puay-Wah; Tan, Joseph-Anthony; Zlock, Lorna; Finkbeiner, Walter E; Verkman, A S

    2016-06-01

    Pendrin (SLC26A4) is a Cl(-)/anion exchanger expressed in the epithelium of inflamed airways where it is thought to facilitate Cl(-) absorption and HCO3 (-) secretion. Studies using pendrin knockout mice and airway epithelial cells from hearing-impaired subjects with pendrin loss of function suggest involvement of pendrin in inflammatory lung diseases, including cystic fibrosis (CF), perhaps by regulation of airway surface liquid (ASL) volume. Here we identified small-molecule pendrin inhibitors and demonstrated their efficacy in increasing ASL volume. A cell-based, functional high-throughput screen of ∼36,000 synthetic small molecules produced 3 chemical classes of inhibitors of human pendrin. After structure-activity studies, tetrahydropyrazolopyridine and pyrazolothiophenesulfonamide compounds reversibly inhibited pendrin-facilitated Cl(-) exchange with SCN(-), I(-), NO3 (-), and HCO3 (-) with drug concentration causing 50% inhibition down to ∼2.5 μM. In well-differentiated primary cultures of human airway epithelial cells from non-CF and CF subjects, treatment with IL-13, which causes inflammation with strong pendrin up-regulation, strongly increased Cl(-)/HCO3 (-) exchange and the increase was blocked by pendrin inhibition. Pendrin inhibition significantly increased ASL depth (by ∼8 μm) in IL-13-treated non-CF and CF cells but not in untreated cells. These studies implicate the involvement of pendrin-facilitated Cl(-)/HCO3 (-) in the regulation of ASL volume and suggest the utility of pendrin inhibitors in inflammatory lung diseases, including CF.-Haggie, P. M., Phuan, P.-W., Tan, J.-A., Zlock, L., Finkbeiner, W. E., Verkman, A. S. Inhibitors of pendrin anion exchange identified in a small molecule screen increase airway surface liquid volume in cystic fibrosis. PMID:26932931

  18. Copper Oxide Nanoparticles Induce Oxidative Stress and Cytotoxicity in Airway Epithelial Cells

    PubMed Central

    Fahmy, Baher; Cormier, Stephania A.

    2009-01-01

    Metal oxide nanoparticles are often used as industrial catalysts and elevated levels of these particles have been clearly demonstrated at sites surrounding factories. To date, limited toxicity data on metal oxide nanoparticles are available. To understand the impact of these airborne pollutants on the respiratory system, airway epithelial (HEp-2) cells were exposed to increasing doses of silicon oxide (SiO2), ferric oxide (Fe2O3) and copper oxide (CuO) nanoparticles, the leading metal oxides found in ambient air surrounding factories. CuO induced the greatest amount of cytotoxicity in a dose dependent manner; while even high doses (400 µg/cm2) of SiO2 and Fe2O3 were non-toxic to HEp-2 cells. Although all metal oxide nanoparticles were able to generate ROS in HEp-2 cells, CuO was better able to overwhelm antioxidant defenses (e.g. catalase and glutathione reductase). A significant increase in the level of 8-isoprostanes and in the ratio of GSSG to total glutathione in cells exposed to CuO suggested that ROS generated by CuO induced oxidative stress in HEp-2 cells. Co-treatment of cells with CuO and the antioxidant resveratrol increased cell viability suggesting that oxidative stress may be the cause of the cytotoxic effect of CuO. These studies demonstrated that there is a high degree of variability in the cytotoxic effects of metal oxides, that this variability is not due to the solubility of the transition metal, and that this variability appears to involve sustained oxidative stress possibly due to redox cycling. PMID:19699289

  19. Pharmacological analysis of epithelial chloride secretion mechanisms in adult murine airways.

    PubMed

    Gianotti, Ambra; Ferrera, Loretta; Philp, Amber R; Caci, Emanuela; Zegarra-Moran, Olga; Galietta, Luis J V; Flores, Carlos A

    2016-06-15

    Defective epithelial chloride secretion occurs in humans with cystic fibrosis (CF), a genetic defect due to loss of function of CFTR, a cAMP-activated chloride channel. In the airways, absence of an active CFTR causes a severe lung disease. In mice, genetic ablation of CFTR function does not result in similar lung pathology. This may be due to the expression of an alternative chloride channel which is activated by calcium. The most probable protein performing this function is TMEM16A, a calcium-activated chloride channel (CaCC). Our aim was to assess the relative contribution of CFTR and TMEM16A to chloride secretion in adult mouse trachea. For this purpose we tested pharmacological inhibitors of chloride channels in normal and CF mice. The amplitude of the cAMP-activated current was similar in both types of animals and was not affected by a selective CFTR inhibitor. In contrast, a CaCC inhibitor (CaCCinh-A01) strongly blocked the cAMP-activated current as well as the calcium-activated chloride secretion triggered by apical UTP. Although control experiments revealed that CaCCinh-A01 also shows inhibitory activity on CFTR, our results indicate that transepithelial chloride secretion in adult mouse trachea is independent of CFTR and that another channel, possibly TMEM16A, performs both cAMP- and calcium-activated chloride transport. The prevalent function of a non-CFTR channel may explain the absence of a defect in chloride transport in CF mice. PMID:27063443

  20. Primary airway epithelial cell culture and asthma in children-lessons learnt and yet to come.

    PubMed

    McLellan, Kirsty; Shields, Mike; Power, Ultan; Turner, Steve

    2015-12-01

    Until recently the airway epithelial cell (AEC) was considered a simple barrier that prevented entry of inhaled matter into the lung parenchyma. The AEC is now recognized as having an important role in the inflammatory response of the respiratory system to inhaled exposures, and abnormalities of these responses are thought to be important to asthma pathogenesis. This review first explores how the challenges of studying nasal and bronchial AECs in children have been addressed and then summarizes the results of studies of primary AEC function in children with and without asthma. There is good evidence that nasal AECs may be a suitable surrogate for the study of certain aspects of bronchial AEC function, although bronchial AECs remain the gold standard for asthma research. There are consistent differences between children with and without asthma for nasal and bronchial AEC mediator release following exposure to a range of pro-inflammatory stimulants including interleukins (IL)-1β, IL-4, and IL-13. However, there are inconsistencies between studies, e.g., release of IL-6, an important pro-inflammatory cytokine, is not increased in children with asthma relative to controls in all studies. Future work should expand current understanding of the "upstream" signalling pathways in AEC, study AEC from children before the onset of asthma symptoms and in vitro models should be developed that replicate the in vivo status more completely, e.g., co-culture with dendritic cells. AECs are difficult to obtain from children and collaboration between centers is expected to yield meaningful advances in asthma understanding and ultimately help deliver novel therapies. PMID:26178976

  1. Nickel Mobilizes Intracellular Zinc to Induce Metallothionein in Human Airway Epithelial Cells

    PubMed Central

    Nemec, Antonia A.; Leikauf, George D.; Pitt, Bruce R.; Wasserloos, Karla J.; Barchowsky, Aaron

    2009-01-01

    We recently reported that induction of metallothionein (MT) was critical in limiting nickel (Ni)-induced lung injury in intact mice. Nonetheless, the mechanism by which Ni induces MT expression is unclear. We hypothesized that the ability of Ni to mobilize zinc (Zn) may contribute to such regulation and therefore, we examined the mechanism for Ni-induced MT2A expression in human airway epithelial (BEAS-2B) cells. Ni induced MT2A transcript levels and protein expression by 4 hours. Ni also increased the activity of a metal response element (MRE) promoter luciferase reporter construct, suggesting that Ni induces MRE binding of the metal transcription factor (MTF-1). Exposure to Ni resulted in the nuclear translocation of MTF-1, and Ni failed to induce MT in mouse embryonic fibroblasts lacking MTF-1. As Zn is the only metal known to directly bind MTF-1, we then showed that Ni increased a labile pool of intracellular Zn in cells as revealed by fluorescence-activated cell sorter using the Zn-sensitive fluorophore, FluoZin-3. Ni-induced increases in MT2A mRNA and MRE-luciferase activity were sensitive to the Zn chelator, TPEN, supporting an important role for Zn in mediating the effect of Ni. Although neither the source of labile Zn nor the mechanism by which Ni liberates labile Zn was apparent, it was noteworthy that Ni increased intracellular reactive oxygen species (ROS). Although both N-acetyl cysteine (NAC) and ascorbic acid (AA) decreased Ni-induced increases in ROS, only NAC prevented Ni-induced increases in MT2A mRNA, suggesting a special role for interactions of Ni, thiols, and Zn release. PMID:19097988

  2. Inhibition of endotoxin-induced airway epithelial cell injury by a novel family of pyrrol derivates.

    PubMed

    Cabrera-Benítez, Nuria E; Pérez-Roth, Eduardo; Ramos-Nuez, Ángela; Sologuren, Ithaisa; Padrón, José M; Slutsky, Arthur S; Villar, Jesús

    2016-06-01

    Inflammation and apoptosis are crucial mechanisms for the development of the acute respiratory distress syndrome (ARDS). Currently, there is no specific pharmacological therapy for ARDS. We have evaluated the ability of a new family of 1,2,3,5-tetrasubstituted pyrrol compounds for attenuating lipopolysaccharide (LPS)-induced inflammation and apoptosis in an in vitro LPS-induced airway epithelial cell injury model based on the first steps of the development of sepsis-induced ARDS. Human alveolar A549 and human bronchial BEAS-2B cells were exposed to LPS, either alone or in combination with the pyrrol derivatives. Rhein and emodin, two representative compounds with proven activity against the effects of LPS, were used as reference compounds. The pyrrol compound that was termed DTA0118 had the strongest inhibitory activity and was selected as the lead compound to further explore its properties. Exposure to LPS caused an intense inflammatory response and apoptosis in both A549 and BEAS-2B cells. DTA0118 treatment downregulated Toll-like receptor-4 expression and upregulated nuclear factor-κB inhibitor-α expression in cells exposed to LPS. These anti-inflammatory effects were accompanied by a significantly lower secretion of interleukin-6 (IL-6), IL-8, and IL-1β. The observed antiapoptotic effect of DTA0118 was associated with the upregulation of antiapoptotic Bcl-2 and downregulation of proapoptotic Bax and active caspase-3 protein levels. Our findings demonstrate the potent anti-inflammatory and antiapoptotic properties of the pyrrol DTA0118 compound and suggest that it could be considered as a potential drug therapy for the acute phase of sepsis and septic ARDS. Further investigations are needed to examine and validate these mechanisms and effects in a clinically relevant animal model of sepsis and sepsis-induced ARDS. PMID:26999659

  3. Protein composition of bronchoalveolar lavage fluid and airway surface liquid from newborn pigs

    PubMed Central

    Bartlett, Jennifer A.; Albertolle, Matthew E.; Wohlford-Lenane, Christine; Pezzulo, Alejandro A.; Zabner, Joseph; Niles, Richard K.; Fisher, Susan J.; McCray, Paul B.

    2013-01-01

    The airway mucosa and the alveolar surface form dynamic interfaces between the lung and the external environment. The epithelial cells lining these barriers elaborate a thin liquid layer containing secreted peptides and proteins that contribute to host defense and other functions. The goal of this study was to develop and apply methods to define the proteome of porcine lung lining liquid, in part, by leveraging the wealth of information in the Sus scrofa database of Ensembl gene, transcript, and protein model predictions. We developed an optimized workflow for detection of secreted proteins in porcine bronchoalveolar lavage (BAL) fluid and in methacholine-induced tracheal secretions [airway surface liquid (ASL)]. We detected 674 and 3,858 unique porcine-specific proteins in BAL and ASL, respectively. This proteome was composed of proteins representing a diverse range of molecular classes and biological processes, including host defense, molecular transport, cell communication, cytoskeletal, and metabolic functions. Specifically, we detected a significant number of secreted proteins with known or predicted roles in innate and adaptive immunity, microbial killing, or other aspects of host defense. In greatly expanding the known proteome of the lung lining fluid in the pig, this study provides a valuable resource for future studies using this important animal model of pulmonary physiology and disease. PMID:23709621

  4. MicroRNA 4423 is a primate-specific regulator of airway epithelial cell differentiation and lung carcinogenesis

    PubMed Central

    Perdomo, Catalina; Campbell, Joshua D.; Gerrein, Joseph; Tellez, Carmen S.; Garrison, Carly B.; Walser, Tonya C.; Drizik, Eduard; Si, Huiqing; Gower, Adam C.; Vick, Jessica; Anderlind, Christina; Jackson, George R.; Mankus, Courtney; Schembri, Frank; O’Hara, Carl; Gomperts, Brigitte N.; Dubinett, Steven M.; Hayden, Patrick; Belinsky, Steven A.; Lenburg, Marc E.; Spira, Avrum

    2013-01-01

    Smoking is a significant risk factor for lung cancer, the leading cause of cancer-related deaths worldwide. Although microRNAs are regulators of many airway gene-expression changes induced by smoking, their role in modulating changes associated with lung cancer in these cells remains unknown. Here, we use next-generation sequencing of small RNAs in the airway to identify microRNA 4423 (miR-4423) as a primate-specific microRNA associated with lung cancer and expressed primarily in mucociliary epithelium. The endogenous expression of miR-4423 increases as bronchial epithelial cells undergo differentiation into mucociliary epithelium in vitro, and its overexpression during this process causes an increase in the number of ciliated cells. Furthermore, expression of miR-4423 is reduced in most lung tumors and in cytologically normal epithelium of the mainstem bronchus of smokers with lung cancer. In addition, ectopic expression of miR-4423 in a subset of lung cancer cell lines reduces their anchorage-independent growth and significantly decreases the size of the tumors formed in a mouse xenograft model. Consistent with these phenotypes, overexpression of miR-4423 induces a differentiated-like pattern of airway epithelium gene expression and reverses the expression of many genes that are altered in lung cancer. Together, our results indicate that miR-4423 is a regulator of airway epithelium differentiation and that the abrogation of its function contributes to lung carcinogenesis. PMID:24158479

  5. MicroRNA 4423 is a primate-specific regulator of airway epithelial cell differentiation and lung carcinogenesis.

    PubMed

    Perdomo, Catalina; Campbell, Joshua D; Gerrein, Joseph; Tellez, Carmen S; Garrison, Carly B; Walser, Tonya C; Drizik, Eduard; Si, Huiqing; Gower, Adam C; Vick, Jessica; Anderlind, Christina; Jackson, George R; Mankus, Courtney; Schembri, Frank; O'Hara, Carl; Gomperts, Brigitte N; Dubinett, Steven M; Hayden, Patrick; Belinsky, Steven A; Lenburg, Marc E; Spira, Avrum

    2013-11-19

    Smoking is a significant risk factor for lung cancer, the leading cause of cancer-related deaths worldwide. Although microRNAs are regulators of many airway gene-expression changes induced by smoking, their role in modulating changes associated with lung cancer in these cells remains unknown. Here, we use next-generation sequencing of small RNAs in the airway to identify microRNA 4423 (miR-4423) as a primate-specific microRNA associated with lung cancer and expressed primarily in mucociliary epithelium. The endogenous expression of miR-4423 increases as bronchial epithelial cells undergo differentiation into mucociliary epithelium in vitro, and its overexpression during this process causes an increase in the number of ciliated cells. Furthermore, expression of miR-4423 is reduced in most lung tumors and in cytologically normal epithelium of the mainstem bronchus of smokers with lung cancer. In addition, ectopic expression of miR-4423 in a subset of lung cancer cell lines reduces their anchorage-independent growth and significantly decreases the size of the tumors formed in a mouse xenograft model. Consistent with these phenotypes, overexpression of miR-4423 induces a differentiated-like pattern of airway epithelium gene expression and reverses the expression of many genes that are altered in lung cancer. Together, our results indicate that miR-4423 is a regulator of airway epithelium differentiation and that the abrogation of its function contributes to lung carcinogenesis. PMID:24158479

  6. Apoptosis and the Airway Epithelium

    PubMed Central

    White, Steven R.

    2011-01-01

    The airway epithelium functions as a barrier and front line of host defense in the lung. Apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. While apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. This paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. PMID:22203854

  7. Acellular Lung Scaffolds Direct Differentiation of Endoderm to Functional Airway Epithelial Cells: Requirement of Matrix-Bound HS Proteoglycans

    PubMed Central

    Shojaie, Sharareh; Ermini, Leonardo; Ackerley, Cameron; Wang, Jinxia; Chin, Stephanie; Yeganeh, Behzad; Bilodeau, Mélanie; Sambi, Manpreet; Rogers, Ian; Rossant, Janet; Bear, Christine E.; Post, Martin

    2015-01-01

    Summary Efficient differentiation of pluripotent cells to proximal and distal lung epithelial cell populations remains a challenging task. The 3D extracellular matrix (ECM) scaffold is a key component that regulates the interaction of secreted factors with cells during development by often binding to and limiting their diffusion within local gradients. Here we examined the role of the lung ECM in differentiation of pluripotent cells in vitro and demonstrate the robust inductive capacity of the native lung matrix alone. Extended culture of stem cell-derived definitive endoderm on decellularized lung scaffolds in defined, serum-free medium resulted in differentiation into mature airway epithelia, complete with ciliated cells, club cells, and basal cells with morphological and functional similarities to native airways. Heparitinase I, but not chondroitinase ABC, treatment of scaffolds revealed that the differentiation achieved is dependent on heparan sulfate proteoglycans and its bound factors remaining on decellularized scaffolds. PMID:25660407

  8. Site of Fluid Secretion in Small Airways.

    PubMed

    Flores-Delgado, Guillermo; Lytle, Christian; Quinton, Paul M

    2016-03-01

    The secretion and management of readily transportable airway surface liquid (ASL) along the respiratory tract is crucial for the clearance of debris and pathogens from the lungs. In proximal large airways, submucosal glands (SMGs) can produce ASL. However, in distal small airways, SMGs are absent, although the lumens of these airways are, uniquely, highly plicated. Little is known about the production and maintenance of ASL in small airways, but using electrophysiology, we recently found that native porcine small airways simultaneously secrete and absorb. How these airways can concurrently transport ASL in opposite directions is puzzling. Using high expression of the Na-K-2Cl cotransport (NKCC) 1 protein (SLC12a2) as a phenotypic marker for fluid secretory cells, immunofluorescence microscopy of porcine small airways revealed two morphologically separated sets of luminal epithelial cells. NKCC1 was abundantly expressed by most cells in the contraluminal regions of the pleats but highly expressed very infrequently by cells in the luminal folds of the epithelial plications. In larger proximal airways, the acini of SMGs expressed NKCC1 prominently, but cells expressing NKCC1 in the surface epithelium were sparse. Our findings indicate that, in the small airway, cells in the pleats of the epithelium secrete ASL, whereas, in the larger proximal airways, SMGs mainly secrete ASL. We propose a mechanism in which the locations of secretory cells in the base of pleats and of absorptive cells in luminal folds physically help maintain a constant volume of ASL in small airways. PMID:26562629

  9. A novel fluorescent sensor protein for detecting changes in airway surface liquid glucose concentration

    PubMed Central

    Helassa, Nordine; Garnett, James P.; Farrant, Matthew; Khan, Faaizah; Pickup, John C.; Hahn, Klaus M.; MacNevin, Christopher J.; Tarran, Robert; Baines, Deborah L.

    2015-01-01

    Both lung disease and elevation of blood glucose are associated with increased glucose concentration (from 0.4 to ~4.0 mM) in the airway surface liquid (ASL). This perturbation of ASL glucose makes the airway more susceptible to infection by respiratory pathogens. ASL is minute (~1 μl/cm2) and the measurement of glucose concentration in the small volume ASL is extremely difficult. Therefore, we sought to develop a fluorescent biosensor with sufficient sensitivity to determine glucose concentrations in ASL in situ. We coupled a range of environmentally sensitive fluorophores to mutated forms of a glucose/galactose-binding protein (GBP) including H152C and H152C/A213R and determined their equilibrium binding properties. Of these, GBP H152C/A213R–BADAN (Kd 0.86 ± 0.01 mM, Fmax/F0 3.6) was optimal for glucose sensing and in ASL increased fluorescence when basolateral glucose concentration was raised from 1 to 20 mM. Moreover, interpolation of the data showed that the glucose concentration in ASL was increased, with results similar to that using glucose oxidase analysis. The fluorescence of GBP H152C/A213R–BADAN in native ASL from human airway epithelial cultures in situ was significantly increased over time when basolateral glucose was increased from 5 to 20 mM. Overall our data indicate that this GBP is a useful tool to monitor glucose homoeostasis in the lung. PMID:25220254

  10. A novel fluorescent sensor protein for detecting changes in airway surface liquid glucose concentration.

    PubMed

    Helassa, Nordine; Garnett, James P; Farrant, Matthew; Khan, Faaizah; Pickup, John C; Hahn, Klaus M; MacNevin, Christopher J; Tarran, Robert; Baines, Deborah L

    2014-12-01

    Both lung disease and elevation of blood glucose are associated with increased glucose concentration (from 0.4 to ~4.0 mM) in the airway surface liquid (ASL). This perturbation of ASL glucose makes the airway more susceptible to infection by respiratory pathogens. ASL is minute (~1 μl/cm(2)) and the measurement of glucose concentration in the small volume ASL is extremely difficult. Therefore, we sought to develop a fluorescent biosensor with sufficient sensitivity to determine glucose concentrations in ASL in situ. We coupled a range of environmentally sensitive fluorophores to mutated forms of a glucose/galactose-binding protein (GBP) including H152C and H152C/A213R and determined their equilibrium binding properties. Of these, GBP H152C/A213R-BADAN (Kd 0.86 ± 0.01 mM, Fmax/F0 3.6) was optimal for glucose sensing and in ASL increased fluorescence when basolateral glucose concentration was raised from 1 to 20 mM. Moreover, interpolation of the data showed that the glucose concentration in ASL was increased, with results similar to that using glucose oxidase analysis. The fluorescence of GBP H152C/A213R-BADAN in native ASL from human airway epithelial cultures in situ was significantly increased over time when basolateral glucose was increased from 5 to 20 mM. Overall our data indicate that this GBP is a useful tool to monitor glucose homoeostasis in the lung. PMID:25220254

  11. Chronic effects of mechanical force on airways.

    PubMed

    Tschumperlin, Daniel J; Drazen, Jeffrey M

    2006-01-01

    Airways are embedded in the mechanically dynamic environment of the lung. In utero, this mechanical environment is defined largely by fluid secretion into the developing airway lumen. Clinical, whole lung, and cellular studies demonstrate pivotal roles for mechanical distention in airway morphogenesis and cellular behavior during lung development. In the adult lung, the mechanical environment is defined by a dynamic balance of surface, tissue, and muscle forces. Diseases of the airways modulate both the mechanical stresses to which the airways are exposed as well as the structure and mechanical behavior of the airways. For instance, in asthma, activation of airway smooth muscle abruptly changes the airway size and stress state within the airway wall; asthma also results in profound remodeling of the airway wall. Data now demonstrate that airway epithelial cells, smooth muscle cells, and fibroblasts respond to their mechanical environment. A prominent role has been identified for the epithelium in transducing mechanical stresses, and in both the fetal and mature airways, epithelial cells interact with mesenchymal cells to coordinate remodeling of tissue architecture in response to the mechanical environment. PMID:16460284

  12. Activation of chloride channels in normal and cystic fibrosis airway epithelial cells by multifunctional calcium/calmodulin-dependent protein kinase

    NASA Astrophysics Data System (ADS)

    Wagner, John A.; Cozens, Alison L.; Schulman, Howard; Gruenert, Dieter C.; Stryer, Lubert; Gardner, Phyllis

    1991-02-01

    CYSTIC fibrosis is associated with defective regulation of apical membrane chloride channels in airway epithelial cells. These channels in normal cells are activated by cyclic AMP-dependent protein kinase1,2 and protein kinase C3,4. In cystic fibrosis these kinases fail to activate otherwise normal Cl- channels1-4. But Cl- flux in cystic fibrosis cells, as in normal cells, can be activated by raising intracellular Ca2+ (refs 5-10). We report here whole-cell patch clamp studies of normal and cystic fibrosis-derived airway epithelial cells showing that Cl- channel activation by Ca2+ is mediated by multifunctional Ca2+/calmodulin-dependent protein kinase. We find that intracellular application of activated kinase and ATP activates a Cl- current similar to that activated by a Ca2+ ionophore, that peptide inhibitors of either the kinase or calmodulin block Ca2+-dependent activation of Cl- channels, and that a peptide inhibitor of protein kinase C does not block Ca2+-dependent activation. Ca2+/calmodulin activation of Cl- channels presents a pathway with therapeutic potential for circumventing defective regulation of Cl- channels in cystic fibrosis.

  13. CRISPR-Cas9-mediated gene knockout in primary human airway epithelial cells reveals a proinflammatory role for MUC18.

    PubMed

    Chu, H W; Rios, C; Huang, C; Wesolowska-Andersen, A; Burchard, E G; O'Connor, B P; Fingerlin, T E; Nichols, D; Reynolds, S D; Seibold, M A

    2015-10-01

    Targeted knockout of genes in primary human cells using CRISPR-Cas9-mediated genome-editing represents a powerful approach to study gene function and to discern molecular mechanisms underlying complex human diseases. We used lentiviral delivery of CRISPR-Cas9 machinery and conditional reprogramming culture methods to knockout the MUC18 gene in human primary nasal airway epithelial cells (AECs). Massively parallel sequencing technology was used to confirm that the genome of essentially all cells in the edited AEC populations contained coding region insertions and deletions (indels). Correspondingly, we found mRNA expression of MUC18 was greatly reduced and protein expression was absent. Characterization of MUC18 knockout cell populations stimulated with TLR2, 3 and 4 agonists revealed that IL-8 (a proinflammatory chemokine) responses of AECs were greatly reduced in the absence of functional MUC18 protein. Our results show the feasibility of CRISPR-Cas9-mediated gene knockouts in AEC culture (both submerged and polarized), and suggest a proinflammatory role for MUC18 in airway epithelial response to bacterial and viral stimuli. PMID:26043872

  14. Anti-Inflammatory Effects of Levalbuterol-Induced 11β-Hydroxysteroid Dehydrogenase Type 1 Activity in Airway Epithelial Cells

    PubMed Central

    Randall, Matthew J.; Kostin, Shannon F.; Burgess, Edward J.; Hoyt, Laura R.; Ather, Jennifer L.; Lundblad, Lennart K.; Poynter, Matthew E.

    2015-01-01

    Airway epithelial NF-κB activation is observed in asthmatic subjects and is a cause of airway inflammation in mouse models of allergic asthma. Combination therapy with inhaled short-acting β2-agonists and corticosteroids significantly improves lung function and reduces inflammation in asthmatic subjects. Corticosteroids operate through a number of mechanisms to potently inhibit NF-κB activity. Since β2-agonists can induce expression of 11β-HSD1, which converts inactive 11-keto corticosteroids into active 11-hydroxy corticosteroids, thereby potentiating the effects of endogenous glucocorticoids, we examined whether this mechanism is involved in the inhibition of NF-κB activation induced by the β-agonist albuterol in airway epithelial cells. Treatment of transformed murine Club cells (MTCC) with (R)-albuterol (levalbuterol), but not with (S)- or a mixture of (R + S)- (racemic) albuterol, augmented mRNA expression of 11β-HSD1. MTCC were stably transfected with luciferase (luc) reporter constructs under transcriptional regulation by NF-κB (NF-κB/luc) or glucocorticoid response element (GRE/luc) consensus motifs. Stimulation of NF-κB/luc MTCC with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNFα) induced luc activity, which was inhibited by pretreatment with (R)-, but not (S)- or racemic albuterol. Furthermore, pretreatment of GRE/luc MTCC with (R)-, but not with (S)- or racemic albuterol, augmented 11-keto corticosteroid (cortisone) induced luc activity, which was diminished by the 11β-HSD inhibitor glycyrrhetinic acid (18β-GA), indicating that there was a conversion of inactive 11-keto to active 11-hydroxy corticosteroids. LPS- and TNFα-induced NF-κB/luc activity was diminished in MTCC cells treated with a combination of cortisone and (R)-albuterol, an effect that was inhibited by 18β-GA. Finally, pretreatment of MTCC cells with the combination of cortisone and (R)-albuterol diminished LPS- and TNFα-induced pro-inflammatory cytokine

  15. Anti-inflammatory effects of levalbuterol-induced 11β-hydroxysteroid dehydrogenase type 1 activity in airway epithelial cells.

    PubMed

    Randall, Matthew J; Kostin, Shannon F; Burgess, Edward J; Hoyt, Laura R; Ather, Jennifer L; Lundblad, Lennart K; Poynter, Matthew E

    2014-01-01

    Airway epithelial NF-κB activation is observed in asthmatic subjects and is a cause of airway inflammation in mouse models of allergic asthma. Combination therapy with inhaled short-acting β2-agonists and corticosteroids significantly improves lung function and reduces inflammation in asthmatic subjects. Corticosteroids operate through a number of mechanisms to potently inhibit NF-κB activity. Since β2-agonists can induce expression of 11β-HSD1, which converts inactive 11-keto corticosteroids into active 11-hydroxy corticosteroids, thereby potentiating the effects of endogenous glucocorticoids, we examined whether this mechanism is involved in the inhibition of NF-κB activation induced by the β-agonist albuterol in airway epithelial cells. Treatment of transformed murine Club cells (MTCC) with (R)-albuterol (levalbuterol), but not with (S)- or a mixture of (R + S)- (racemic) albuterol, augmented mRNA expression of 11β-HSD1. MTCC were stably transfected with luciferase (luc) reporter constructs under transcriptional regulation by NF-κB (NF-κB/luc) or glucocorticoid response element (GRE/luc) consensus motifs. Stimulation of NF-κB/luc MTCC with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNFα) induced luc activity, which was inhibited by pretreatment with (R)-, but not (S)- or racemic albuterol. Furthermore, pretreatment of GRE/luc MTCC with (R)-, but not with (S)- or racemic albuterol, augmented 11-keto corticosteroid (cortisone) induced luc activity, which was diminished by the 11β-HSD inhibitor glycyrrhetinic acid (18β-GA), indicating that there was a conversion of inactive 11-keto to active 11-hydroxy corticosteroids. LPS- and TNFα-induced NF-κB/luc activity was diminished in MTCC cells treated with a combination of cortisone and (R)-albuterol, an effect that was inhibited by 18β-GA. Finally, pretreatment of MTCC cells with the combination of cortisone and (R)-albuterol diminished LPS- and TNFα-induced pro-inflammatory cytokine

  16. High-mobility group box 1 impairs airway epithelial barrier function through the activation of the RAGE/ERK pathway

    PubMed Central

    HUANG, WUFENG; ZHAO, HAIJIN; DONG, HANGMING; WU, YUE; YAO, LIHONG; ZOU, FEI; CAI, SHAOXI

    2016-01-01

    Recent studies have indicated that high-mobility group box 1 protein (HMGB1) and the receptor for advanced glycation end-products (RAGE) contribute to the pathogenesis of asthma. However, whether the activation of the HMGB1/RAGE axis mediates airway epithelial barrier dysfunction remains unknown. Thus, the aim of this study was to examine the effects of HMGB1 and its synergistic action with interleukin (IL)-1β on airway epithelial barrier properties. We evaluated the effects of recombinant human HMGB1 alone or in combination with IL-1β on ionic and macromolecular barrier permeability, by culturing air-liquid interface 16HBE cells with HMGB1 to mimic the differentiated epithelium. Western blot analysis and immunofluorescence staining were utilized to examine the level and structure of major junction proteins, namely E-cadherin, β-catenin, occludin and claudin-1. Furthermore, we examined the effects of RAGE neutralizing antibodies and mitogen-activated protein kinase (MAPK) inhibitors on epithelial barrier properties in order to elucidate the mechanisms involved. HMGB1 increased FITC-dextran permeability, but suppressed epithelial resistance in a dose-and time-dependent manner. HMGB1-mediated barrier hyperpermeability was accompanied by a disruption of cell-cell contacts, the selective downregulation of occludin and claudin-1, and the redistribution of E-cadherin and β-catenin. HMGB1 in synergy with IL-1β induced a similar, but greater barrier hyperpermeability and induced the disruption of junction proteins. Furthermore, HMGB1 elicited the activation of the RAGE/extracellular signal-related kinase (ERK)1/2 signaling pathway, which correlated with barrier dysfunction in the 16HBE cells. Anti-RAGE antibody and the ERK1/2 inhibitor, U0126, attenuated the HMGB1-mediated changes in barrier permeability, restored the expression levels of occludin and claudin-1 and pevented the redistribution of E-cadherin and β-catenin. Taken together, the findings of our study

  17. High-mobility group box 1 impairs airway epithelial barrier function through the activation of the RAGE/ERK pathway.

    PubMed

    Huang, Wufeng; Zhao, Haijin; Dong, Hangming; Wu, Yue; Yao, Lihong; Zou, Fei; Cai, Shaoxi

    2016-05-01

    Recent studies have indicated that high-mobility group box 1 protein (HMGB1) and the receptor for advanced glycation end-products (RAGE) contribute to the pathogenesis of asthma. However, whether the activation of the HMGB1/RAGE axis mediates airway epithelial barrier dysfunction remains unknown. Thus, the aim of this study was to examine the effects of HMGB1 and its synergistic action with interleukin (IL)-1β on airway epithelial barrier properties. We evaluated the effects of recombinant human HMGB1 alone or in combination with IL-1β on ionic and macromolecular barrier permeability, by culturing air-liquid interface 16HBE cells with HMGB1 to mimic the differentiated epithelium. Western blot analysis and immunofluorescence staining were utilized to examine the level and structure of major junction proteins, namely E-cadherin, β-catenin, occludin and claudin-1. Furthermore, we examined the effects of RAGE neutralizing antibodies and mitogen-activated protein kinase (MAPK) inhibitors on epithelial barrier properties in order to elucidate the mechanisms involved. HMGB1 increased FITC-dextran permeability, but suppressed epithelial resistance in a dose- and time-dependent manner. HMGB1-mediated barrier hyperpermeability was accompanied by a disruption of cell-cell contacts, the selective downregulation of occludin and claudin-1, and the redistribution of E-cadherin and β-catenin. HMGB1 in synergy with IL-1β induced a similar, but greater barrier hyperpermeability and induced the disruption of junction proteins. Furthermore, HMGB1 elicited the activation of the RAGE/extracellular signal-related kinase (ERK)1/2 signaling pathway, which correlated with barrier dysfunction in the 16HBE cells. Anti-RAGE antibody and the ERK1/2 inhibitor, U0126, attenuated the HMGB1-mediated changes in barrier permeability, restored the expression levels of occludin and claudin-1 and pevented the redistribution of E-cadherin and β-catenin. Taken together, the findings of our study

  18. Restoration of Chloride Efflux by Azithromycin in Airway Epithelial Cells of Cystic Fibrosis Patients▿

    PubMed Central

    Saint-Criq, Vinciane; Rebeyrol, Carine; Ruffin, Manon; Roque, Telma; Guillot, Loïc; Jacquot, Jacky; Clement, Annick; Tabary, Olivier

    2011-01-01

    Azithromycin (AZM) has shown promising anti-inflammatory properties in chronic obstructive pulmonary diseases, and clinical studies have presented an improvement in the respiratory condition of cystic fibrosis (CF) patients. The aim of this study was to investigate, in human airway cells, the mechanism by which AZM has beneficial effects in CF. We demonstrated that AZM did not have any anti-inflammatory effect on CF airway cells but restored Cl− efflux. PMID:21220528

  19. Biodiesel exhaust-induced cytotoxicity and proinflammatory mediator production in human airway epithelial cells.

    PubMed

    Mullins, Benjamin J; Kicic, Anthony; Ling, Kak-Ming; Mead-Hunter, Ryan; Larcombe, Alexander N

    2016-01-01

    Increasing use of biodiesel has prompted research into the potential health effects of biodiesel exhaust exposure. Few studies directly compare the health consequences of mineral diesel, biodiesel, or blend exhaust exposures. Here, we exposed human epithelial cell cultures to diluted exhaust generated by the combustion of Australian ultralow-sulfur-diesel (ULSD), unprocessed canola oil, 100% canola biodiesel (B100), and a blend of 20% canola biodiesel mixed with 80% ULSD. The physicochemical characteristics of the exhaust were assessed and we compared cellular viability, apoptosis, and levels of interleukin (IL)-6, IL-8, and Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) in exposed cultured cells. Different fuel types produced significantly different amounts of exhaust gases and different particle characteristics. All exposures resulted in significant apoptosis and loss of viability when compared with control, with an increasing proportion of biodiesel being correlated with a decrease in viability. In most cases, exposure to exhaust resulted in an increase in mediator production, with the greatest increases most often in response to B100. Exposure to pure canola oil (PCO) exhaust did not increase mediator production, but resulted in a significant decrease in IL-8 and RANTES in some cases. Our results show that canola biodiesel exhaust exposure elicits inflammation and reduces viability of human epithelial cell cultures in vitro when compared with ULSD exhaust exposure. This may be related to an increase in particle surface area and number in B100 exhaust when compared with ULSD exhaust. Exposure to PCO exhaust elicited the greatest loss of cellular viability, but virtually no inflammatory response, likely due to an overall increase in average particle size. PMID:25045158

  20. Proteomic Changes of Tissue-Tolerable Plasma Treated Airway Epithelial Cells and Their Relation to Wound Healing

    PubMed Central

    Lendeckel, Derik; Eymann, Christine; Emicke, Philipp; Daeschlein, Georg; Darm, Katrin; O'Neil, Serena; Beule, Achim G.; von Woedtke, Thomas; Völker, Uwe; Weltmann, Klaus-Dieter; Jünger, Michael; Hosemann, Werner; Scharf, Christian

    2015-01-01

    Background. The worldwide increasing number of patients suffering from nonhealing wounds requires the development of new safe strategies for wound repair. Recent studies suggest the possibility of nonthermal (cold) plasma application for the acceleration of wound closure. Methods. An in vitro wound healing model with upper airway S9 epithelial cells was established to determine the macroscopically optimal dosage of tissue-tolerable plasma (TTP) for wound regeneration, while a 2D-difference gel electrophoresis (2D-DIGE) approach was used to quantify the proteomic changes in a hypothesis-free manner and to evaluate the balance of beneficial and adverse effects due to TTP application. Results. Plasma doses from 30 s up to 360 s were tested in relation to wound closure after 24 h, 48 h, 72 h, 96 h, and 120 h, in which lower doses (30, 60, and 120 s) resulted in dose-dependent improved wound healing rate compared to untreated cells. Thereby, the 120 s dose caused significantly the best wound healing properties after 96 and 120 h. The proteome analysis combined with IPA revealed that a lot of affected stress adaptation responses are linked to oxidative stress response emphasizing oxidative stress as a possible key event in the regeneration process of epithelial cells as well as in the adaptation to plasma exposure. Further cellular and molecular functions like proliferation and apoptosis were significantly up- or downregulated by all TTP treatments but mostly by the 120 s dose. Conclusions. For the first time, we were able to show plasma effects on cellular adaptation of upper airway epithelial S9 cells improving wound healing. This is of particular interest for plasma application, for example, in the surgery field of otorhinolaryngology or internal medicine. PMID:26539504

  1. Breath condensate hydrogen peroxide correlates with both airway cytology and epithelial lining fluid ascorbic acid concentration in the horse.

    PubMed

    Deaton, Christopher M; Marlin, David J; Smith, Nicola C; Smith, Ken C; Newton, Richard J; Gower, Susan M; Cade, Susan M; Roberts, Colin A; Harris, Pat A; Schroter, Robert C; Kelly, Frank J

    2004-02-01

    The relationship between hydrogen peroxide (H2O2) concentration in expired breath condensate (EBC) and cytology of the respiratory tract obtained from tracheal wash (TW) or bronchoalveolar lavage (BAL), and epithelial lining fluid (ELF) antioxidant status is unknown. To examine this we analysed the concentration of H2O2 in breath condensate from healthy horses and horses affected by recurrent airway obstruction (RAO), a condition considered to be an animal model of human asthma. The degree of airway inflammation was determined by assessing TW inflammation as mucus, cell density and neutrophil scores, and by BAL cytology. ELF antioxidant status was determined by measurement of ascorbic acid, dehydroascorbate, reduced and oxidised glutathione, uric acid and alpha-tocopherol concentrations. RAO-affected horses with marked airway inflammation had significantly higher concentrations of breath condensate H2O2 than control horses and RAO-affected horses in the absence of inflammation (2.0 +/- 0.5 micromol/l. 0.4 +/- 0.2 micromol/l and 0.9 +/- 0.2 micromol/l H2O2, respectively; p < 0.0001). The concentration of breath condensate H2O2 was related inversely to the concentration of ascorbic acid in ELF (r = -0.80; p < 0.0001) and correlated positively with TW inflammation score (r = 0.76, p < 0.0001) and BAL neutrophil count (r = 0.80, p < 0.0001). We conclude that the concentration of H2O2 in breath condensate influences the ELF ascorbic acid concentration and provides a non-invasive diagnostic indicator of the severity of neutrophilic airway inflammation. PMID:15104214

  2. 15-Lipoxygenase 1 interacts with phosphatidylethanolamine-binding protein to regulate MAPK signaling in human airway epithelial cells

    PubMed Central

    Zhao, Jinming; O'Donnell, Valerie B.; Balzar, Silvana; St. Croix, Claudette M.; Trudeau, John B.; Wenzel, Sally E.

    2011-01-01

    Epithelial 15-lipoxygenase 1 (15LO1) and activated ERK are increased in asthma despite modest elevations in IL-13. MAPK kinase (MEK)/ERK activation is regulated by interactions of Raf-1 with phosphatidylethanolamine-binding protein 1 (PEBP1). Epithelial 15LO1 generates intracellular 15-hydroxyeicosatetraenoic acid (15HETE) conjugated to phosphatidylethanolamine (PE) (15HETE–PE). We hypothesized that (i) 15LO1 and its product 15HETE–PE serve as signaling molecules interacting with PEBP1 to activate Raf-1/MEK/ERK and that (ii) this 15LO1–15HETE–PE-regulated ERK activation amplifies IL-4Rα downstream pathways. Our results demonstrate that high epithelial 15LO1 levels correlate with ERK phosphorylation ex vivo. In vitro, IL-13 induces 15LO1, which preferentially binds to PEBP1, causing PEBP1 to dissociate from Raf-1 and activate ERK. Exogenous 15HETE–PE similarly induces dissociation of PEBP1 from Raf-1 independently of IL-13/15LO1. siRNA knockdown of 15LO1 decreases the dissociation of Raf-1 from PEBP1, and the resulting lower ERK activation leads to lower downstream IL-4Rα–related gene expression. Identical protein–protein interactions are observed in endobronchial biopsies and fresh epithelial cells from asthmatics ex vivo. Colocalization of Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma. Low 15LO1 levels in normals limit its colocalization with PEBP1. The results confirm a previously unknown signaling role for 15LO1 and its PE-conjugated eicosanoid product in human airway epithelial cells. This pathway enhances critical inflammatory pathways integral to asthma pathogenesis. PMID:21831839

  3. 15-Lipoxygenase 1 interacts with phosphatidylethanolamine-binding protein to regulate MAPK signaling in human airway epithelial cells.

    PubMed

    Zhao, Jinming; O'Donnell, Valerie B; Balzar, Silvana; St Croix, Claudette M; Trudeau, John B; Wenzel, Sally E

    2011-08-23

    Epithelial 15-lipoxygenase 1 (15LO1) and activated ERK are increased in asthma despite modest elevations in IL-13. MAPK kinase (MEK)/ERK activation is regulated by interactions of Raf-1 with phosphatidylethanolamine-binding protein 1 (PEBP1). Epithelial 15LO1 generates intracellular 15-hydroxyeicosatetraenoic acid (15HETE) conjugated to phosphatidylethanolamine (PE) (15HETE-PE). We hypothesized that (i) 15LO1 and its product 15HETE-PE serve as signaling molecules interacting with PEBP1 to activate Raf-1/MEK/ERK and that (ii) this 15LO1-15HETE-PE-regulated ERK activation amplifies IL-4Rα downstream pathways. Our results demonstrate that high epithelial 15LO1 levels correlate with ERK phosphorylation ex vivo. In vitro, IL-13 induces 15LO1, which preferentially binds to PEBP1, causing PEBP1 to dissociate from Raf-1 and activate ERK. Exogenous 15HETE-PE similarly induces dissociation of PEBP1 from Raf-1 independently of IL-13/15LO1. siRNA knockdown of 15LO1 decreases the dissociation of Raf-1 from PEBP1, and the resulting lower ERK activation leads to lower downstream IL-4Rα-related gene expression. Identical protein-protein interactions are observed in endobronchial biopsies and fresh epithelial cells from asthmatics ex vivo. Colocalization of Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma. Low 15LO1 levels in normals limit its colocalization with PEBP1. The results confirm a previously unknown signaling role for 15LO1 and its PE-conjugated eicosanoid product in human airway epithelial cells. This pathway enhances critical inflammatory pathways integral to asthma pathogenesis. PMID:21831839

  4. Effect of Host Modification and Age on Airway Epithelial Gene Transfer Mediated by a Murine Leukemia Virus-Derived Vector

    PubMed Central

    Johnson, Larry G.; Mewshaw, Jennifer P.; Ni, Hong; Friedmann, Theodore; Boucher, Richard C.; Olsen, John C.

    1998-01-01

    To study retroviral gene transfer to airway epithelia, we used a transient transfection technique to generate high titers (∼109 infectious units/ml after concentration) of murine leukemia virus (MuLV)-derived vectors pseudotyped with the vesicular stomatitis virus envelope glycoprotein (VSV-G). Transformed (CFT1) and primary airway epithelial cells were efficiently transduced by a VSV-G-pseudotyped lacZ vector (HIT-LZ) in vitro. CFT1 cells and primary cystic fibrosis (CF) airway cell monolayers infected with a vector (HIT-LCFSN) containing human CF transmembrane conductance regulator (CFTR) in the absence of selection expressed CFTR, as assessed by Western blot analysis, and exhibited functional correction of CFTR-mediated Cl− secretion. In vitro studies of persistence suggested that pseudotransduction was not a significant problem with our vector preparations. In a sulfur dioxide (SO2) inhalational injury model, bromodeoxyuridine (BrdU) incorporation rates were measured and found to exceed 50% in SO2-injured murine tracheal epithelium. HIT-LZ vector (multiplicity of infection of ∼10) instilled into the SO2-injured tracheas of anesthetized mice transduced 6.1% ± 1.3% of superficial airway cells in tracheas of weanling mice (3 to 4 weeks old; n = 10), compared to 1.4 ± 0.9% in mice 5 weeks of age (n = 4) and 0.2% in mice older than 6 weeks (n = 15). No evidence for gene transfer following delivery of HIT-LZ to tracheas of either weanling or older mice not injured with SO2 was detected. Because only a small fraction of BrdU-labeled airway cells were transduced, we examined the stability of the vector. No significant loss of vector infectivity over intervals (2 h) paralleling those of in vivo protocols was detected in in vitro assays using CFT1 cells. In summary, high-titer vectors permitted complementation of defective CFTR-mediated Cl− transport in CF airway cells in vitro without selection and demonstrated that the age of the animal appeared to be a major

  5. Expression of a TGF-{beta} regulated cyclin-dependent kinase inhibitor in normal and immortalized airway epithelial cells

    SciTech Connect

    Tierney, L.A.; Bloomfield, C.; Johnson, N.F.

    1995-12-01

    Tumors arising from epithelial cells, including lung cancers are frequently resistant to factors that regulate growth and differentiation in normal in normal cells. Once such factor is transforming growth factor-{Beta} (TGF-{Beta}). Escape from the growth-inhibitory effects of TGF-{Beta} is thought to be a key step in the transformation of airway epithelial cells. most lung cancer cell lines require serum for growth. In contrast, normal human bronchial epithelial (NHBE) cells are exquisitely sensitive to growth-inhibitory and differentiating effects of TGF-{Beta}. The recent identification of a novel cyclin-dependent kinase inhibitor, p15{sup INK4B}, which is regulated by TGF-{Beta}, suggests a mechanism by which TGF-{Beta} mediates growth arrest in NHBE cells. The purpose of this study was two-fold: (1) to determine if p15{sup INK4B} is induced by TGF-{Beta} in NHBE cells or immortalized bronchial epithelial (R.1) cells and if that induction corresponds to a G1/S cell-cycle arrest; (2) to determine the temporal relationship between p15{sup INK4B} induction, cell-cycle arrest, and the phosphorylation state of the pRB because it is thought that p15{sup INK4B} acts indirectly by preventing phosphorylation of the RB gene product. In this study, expression of p15{sup INK4B} was examined in NHBE cells and R.1 cells at different time intervals following TGF-{Beta} treatment. The expression of this kinase inhibitor and its relationship to the cell and the pRb phosphorylation state were examined in cells that were both sensitive (NHBE) and resistant (R.1) to the effects of TGF-{Beta}. These results suggest that the cyclin-dependent kinase inhibitor, p15{sup INK4B}, is involved in airway epithelial cell differentiation and that loss or reduction of expression plays a role in the resistance of transformed or neoplastic cells to the growth-inhibitory effects of TGF-{Beta}.

  6. Epithelial Proliferation on Curved Toroidal Surfaces

    NASA Astrophysics Data System (ADS)

    Chang, Ya-Wen; Cruz, Ricardo; Fragkopoulos, Alexandros; Marquez, Samantha; Garcia, Andres; Fernandez-Nieves, Alberto

    Cellular environment influences a multitude of cellular functions by providing chemical and physical signals that modulate cell behavior, dynamics, development, and eventually survival. In strongly interacting epithelial cells, cells coordinate their behavior to respond to mechanical constraints in 2D. Local differences in tissue tension has also been shown to impact cell reproduction within an epithelial-cell sheet. Much less is known about how cells respond to out-of-plane curvatures. Here, we describe the proliferation of MDCK on toroidal hydrogel substrates, which unlike spheres or planes, have regions of both positive and negative Gaussian curvature. Additionally, the range of curvatures can be controlled by varying the size and aspect ratio of the torus, allowing us to quantify the relation between substrate curvature and cell proliferation.

  7. Hyperosmolar solution effects in guinea pig airways. IV. Lipopolysaccharide-induced alterations in airway reactivity and epithelial bioelectric responses to methacholine and hyperosmolarity.

    PubMed

    Johnston, Richard A; Van Scott, Michael R; Kommineni, Choudari; Millecchia, Lyndell L; Dortch-Carnes, Juanita; Fedan, Jeffrey S

    2004-01-01

    We investigated the in vivo and in vitro effects of lipopolysaccharide (LPS) treatment (4 mg/kg i.p.) on guinea pig airway smooth muscle reactivity and epithelial bioelectric responses to methacholine (MCh) and hyperosmolarity. Hyperosmolar challenge of the epithelium releases epithelium-derived relaxing factor (EpDRF). Using a two-chamber, whole body plethysmograph 18 h post-treatment, animals treated with LPS were hyporeactive to inhaled MCh aerosol. This could involve an increase in the release and/or actions of EpDRF, because LPS treatment enhanced EpDRF-induced smooth muscle relaxation in vitro in the isolated perfused trachea apparatus. In isolated perfused tracheas the basal transepithelial potential difference (Vt) was increased after LPS treatment. The increase in Vt was inhibited by amiloride and indomethacin. Concentration-response curves for changes in Vt in response to serosally and mucosally applied MCh were biphasic (hyperpolarization, <3 x 10(-7)M; depolarization, >3 x 10(-7)M); MCh was more potent when applied serosally. The hyperpolarization response to MCh, but not the depolarization response, was potentiated after LPS treatment. In both treatment groups, mucosally applied hyperosmolar solution (using added NaCl) depolarized the epithelium; this response was greater in tracheas from LPS-treated animals. The results of this study indicate that airway hyporeactivity in vivo after LPS treatment is accompanied by an increase in the release and/or actions of EpDRF in vitro. These changes may involve LPS-induced bioelectric alterations in the epithelium. PMID:14566002

  8. Growth of airway epithelial cells at an air-liquid interface changes both the response to particle exposure and iron homeostasis.

    EPA Science Inventory

    RATIONALE: We tested the hypothesis that 1) relative to submerged cells, airway epithelial cells grown at an air-liquid interface and allowed to differentiate would have an altered response to particle exposure and 2) that these differences would be associated with indices of iro...

  9. MATRIX METALLOPROTEINS (MMP)-MEDIATED PHOSPHORYLATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) IN HUMAN AIRWAY EPITHELIAL CELLS (HAEC) EXPOSED TO ZINC (ZN)

    EPA Science Inventory

    Matrix Metalloproteinase (MMP)-Mediated Phosphorylation of The Epidermal Growth Factor Receptor (EGFR) in Human Airway Epithelial Cells (HAEC) Exposed to Zinc (Zn)
    Weidong Wu, James M. Samet, Robert Silbajoris, Lisa A. Dailey, Lee M. Graves, and Philip A. Bromberg
    Center fo...

  10. Clara Cell 10-kDa Protein Gene Transfection Inhibits NF-κB Activity in Airway Epithelial Cells

    PubMed Central

    Long, Xiao-Bo; Hu, Shuang; Wang, Nan; Zhen, Hong-Tao; Cui, Yong-Hua; Liu, Zheng

    2012-01-01

    Background Clara cell 10-kDa protein (CC10) is a multifunctional protein with anti-inflammatory and immunomodulatory effects. Induction of CC10 expression by gene transfection may possess potential therapeutic effect. Nuclear factor κB (NF-κB) plays a key role in the inflammatory processes of airway diseases. Method/Results To investigate potential therapeutic effect of CC10 gene transfection in controlling airway inflammation and the underlying intracellular mechanisms, in this study, we constructed CC10 plasmid and transfected it into bronchial epithelial cell line BEAS-2B cells and CC10 knockout mice. In BEAS-2B cells, CC10's effect on interleukin (IL)-1β induced IL-8 expression was explored by means of RT-PCR and ELISA and its effect on NF-κB classical signaling pathway was studied by luciferase reporter, western blot, and immunoprecipitation assay. The effect of endogenous CC10 on IL-1β evoked IL-8 expression was studied by means of nasal explant culture. In mice, CC10's effect on IL-1β induced IL-8 and nuclear p65 expression was examined by immunohistochemistry. First, we found that the CC10 gene transfer could inhibit IL-1β induced IL-8 expression in BEAS-2B cells. Furthermore, we found that CC10 repressed IL-1β induced NF-κB activation by inhibiting the phosphorylation of IκB-α but not IκB kinase-α/β in BEAS-2B cells. Nevertheless, we did not observe a direct interaction between CC10 and p65 subunit in BEAS-2B cells. In nasal explant culture, we found that IL-1β induced IL-8 expression was inversely correlated with CC10 levels in human sinonasal mucosa. In vivo study revealed that CC10 gene transfer could attenuate the increase of IL-8 and nuclear p65 staining in nasal epithelial cells in CC10 knockout mice evoked by IL-1β administration. Conclusion These results indicate that CC10 gene transfer may inhibit airway inflammation through suppressing the activation of NF-κB, which may provide us a new consideration in the therapy of airway

  11. Fetal Exposure of Rhesus Macaques to Bisphenol A Alters Cellular Development of the Conducting Airway by Changing Epithelial Secretory Product Expression

    PubMed Central

    Murphy, Shannon R.; Boetticher, Miriam V.; VandeVoort, Catherine A.

    2013-01-01

    Background: Bisphenol A (BPA) exposure early in life results in organizational changes in reproductive organs, but the effect of BPA on conducting airway cellular maturation has not been studied. Late gestation is characterized by active differentiation of secretory cells in the lung epithelium. Objective: We evaluated the hypothesis that BPA exposure disrupts epithelial secretory cell development in the fetal conducting airway of the rhesus macaque. Methods: We exposed animals to BPA during either the second (early term) or the third (late term) trimester. There were four treatment groups: a) sham control early term, b) sham control late term, c) BPA early term (BPA-early), and d) BPA late term (BPA-late). Because cellular maturation occurs nonuniformly in the lung, we defined mRNA and protein expression by airway level using microdissection. Results: BPA exposure of the dam during late term significantly accelerated secretory cell maturation in the proximal airways of the fetus; both Clara cell secretory protein (CCSP) and MUC5AC/5B mRNA and protein expression increased. Conclusions: BPA exposure during late gestation accelerates secretory cell maturation in the proximal conducting airways. We identified a critical window of fetal susceptibility for BPA effects on lung epithelial cell maturation in the third trimester. This is of environmental health importance because increases in airway mucins are hallmarks of a number of childhood lung diseases that may be affected by BPA exposure. PMID:23757601

  12. Airway Epithelial Cells are the Site of Expression of a Mammalian Antimicrobial Peptide Gene

    NASA Astrophysics Data System (ADS)

    Diamond, Gill; Jones, Douglas E.; Bevins, Charles L.

    1993-05-01

    We previously reported the isolation and characterization of a broad-spectrum antimicrobial peptide from the bovine tracheal mucosa, which we called tracheal antimicrobial peptide (TAP). We now show the TAP gene is expressed throughout the adult conducting airway, from nasal to bronchiolar tissue, but not in tissues other than airway mucosa, as determined by Northern blot analysis. In situ hybridization of airway sections localizes TAP mRNA to columnar cells of the pseudostratified epithelium. We report the structural organization of the TAP gene and show that TAP is a member of a large family of related sequences with high nucleotide identity in the 5'exon. The data support the hypothesis that antimicrobial peptides contribute to host defense of the respiratory tract.

  13. PROINFLAMMATORY OXIDANT HYPOCHLOROUS ACID (HOCL) INDUCES DUAL SIGNALING PATHWAYS IN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    In the airway of inflammatory diseases such as bacterial infection, cystic fibrosis and COPD, high level of HOCL (local concentration of up to 5mM) can be generated through a reaction catalyzed by leukocyte granule enzyme- Myeloperoxidase (MPO). HOCL is a very potent oxidative ag...

  14. Bioelectric and Morphological Response of Liquid-Covered Human Airway Epithelial Calu-3 Cell Monolayer to Periodic Deposition of Colloidal 3-Mercaptopropionic-Acid Coated CdSe-CdS/ZnS Core-Multishell Quantum Dots

    PubMed Central

    Turdalieva, Aizat; Solandt, Johan; Shambetova, Nestan; Xu, Hao; Blom, Hans; Brismar, Hjalmar; Zelenina, Marina; Fu, Ying

    2016-01-01

    Lung epithelial cells are extensively exposed to nanoparticles present in the modern urban environment. Nanoparticles, including colloidal quantum dots (QDs), are also considered to be potentially useful carriers for the delivery of drugs into the body. It is therefore important to understand the ways of distribution and the effects of the various types of nanoparticles in the lung epithelium. We use a model system of liquid-covered human airway epithelial Calu-3 cell cultures to study the immediate and long-term effects of repeated deposition of colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs on the lung epithelial cell surface. By live confocal microscope imaging and by QD fluorescence measurements we show that the QD permeation through the mature epithelial monolayers is very limited. At the time of QD deposition, the transepithelial electrical resistance (TEER) of the epithelial monolayers transiently decreased, with the decrement being proportional to the QD dose. Repeated QD deposition, once every six days for two months, lead to accumulation of only small amounts of the QDs in the cell monolayer. However, it did not induce any noticeable changes in the long-term TEER and the molecular morphology of the cells. The colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs could therefore be potentially used for the delivery of drugs intended for the surface of the lung epithelia during limited treatment periods. PMID:26913754

  15. Bioelectric and Morphological Response of Liquid-Covered Human Airway Epithelial Calu-3 Cell Monolayer to Periodic Deposition of Colloidal 3-Mercaptopropionic-Acid Coated CdSe-CdS/ZnS Core-Multishell Quantum Dots.

    PubMed

    Turdalieva, Aizat; Solandt, Johan; Shambetova, Nestan; Xu, Hao; Blom, Hans; Brismar, Hjalmar; Zelenina, Marina; Fu, Ying

    2016-01-01

    Lung epithelial cells are extensively exposed to nanoparticles present in the modern urban environment. Nanoparticles, including colloidal quantum dots (QDs), are also considered to be potentially useful carriers for the delivery of drugs into the body. It is therefore important to understand the ways of distribution and the effects of the various types of nanoparticles in the lung epithelium. We use a model system of liquid-covered human airway epithelial Calu-3 cell cultures to study the immediate and long-term effects of repeated deposition of colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs on the lung epithelial cell surface. By live confocal microscope imaging and by QD fluorescence measurements we show that the QD permeation through the mature epithelial monolayers is very limited. At the time of QD deposition, the transepithelial electrical resistance (TEER) of the epithelial monolayers transiently decreased, with the decrement being proportional to the QD dose. Repeated QD deposition, once every six days for two months, lead to accumulation of only small amounts of the QDs in the cell monolayer. However, it did not induce any noticeable changes in the long-term TEER and the molecular morphology of the cells. The colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs could therefore be potentially used for the delivery of drugs intended for the surface of the lung epithelia during limited treatment periods. PMID:26913754

  16. Extracellular nucleotides regulate CCL20 release from human primary airway epithelial cells, monocytes and monocyte-derived dendritic cells.

    PubMed

    Marcet, Brice; Horckmans, Michael; Libert, Frédérick; Hassid, Sergio; Boeynaems, Jean-Marie; Communi, Didier

    2007-06-01

    Extracellular nucleotides regulate ion transport and mucociliary clearance in human airway epithelial cells (HAECs) via the activation of P2 receptors, especially P2Y(2). Therefore, P2Y(2) receptor agonists represent potential pharmacotherapeutic agents to treat cystic fibrosis (CF). Nucleotides also modulate inflammatory properties of immune cells like dendritic cells (DCs), which play an important role in mucosal immunity. Using DNA-microarray experiments, quantitative RT-PCR and cytokine measurements, we show here that UTP up-regulated approximately 2- to 3-fold the antimicrobial chemokine CCL20 expression and release in primary HAECs cultured on permeable supports at an air-liquid interface (ALI). Both P2Y(2) (ATPgammaS, UTP, INS365) and P2Y(6) (UDP, INS48823) agonists increased CCL20 release. UTP-induced CCL20 release was insensitive to NF-kappaB pathway inhibitors but sensitive to inhibitors of ERK1/2 and p38/MAPK pathways. Furthermore, UTP had no effect on interleukin-(IL)-8 release and reduced the release of both CCL20 and IL-8 induced by TNF-alpha and LPS. Accordingly, UTP reduced the capacity of basolateral supernatants of HAECs treated with TNF-alpha or LPS to induce the chemoattraction of both CD4(+) T lymphocytes and neutrophils. In addition, we show that, in monocyte-derived DCs, ATPgammaS, and UDP but not UTP/INS365-stimulated CCL20 release. Likewise, UDP but not ATPgammaS was also able to increase CCL20 release from monocytes. Pharmacological experiments suggested an involvement of P2Y(11) or P2Y(6) receptors through NF-kappaB, ERK1/2, and p38/MAPK pathways. Altogether, our data demonstrate that nucleotides may modulate chemokine release and leukocyte recruitment in inflamed airways by acting on both epithelial and immune cells. Our results could be relevant for further clinical investigations in CF. PMID:17295217

  17. Wood smoke enhances cigarette smoke-induced inflammation by inducing the aryl hydrocarbon receptor repressor in airway epithelial cells.

    PubMed

    Awji, Elias G; Chand, Hitendra; Bruse, Shannon; Smith, Kevin R; Colby, Jennifer K; Mebratu, Yohannes; Levy, Bruce D; Tesfaigzi, Yohannes

    2015-03-01

    Our previous studies showed that cigarette smokers who are exposed to wood smoke (WS) are at an increased risk for chronic bronchitis and reduced lung function. The present study was undertaken to determine the mechanisms for WS-induced adverse effects. We studied the effect of WS exposure using four cohorts of mice. C57Bl/6 mice were exposed for 4 or 12 weeks to filtered air, to 10 mg/m(3) WS for 2 h/d, to 250 mg/m(3) cigarette smoke (CS) for 6 h/d, or to CS followed by WS (CW). Inflammation was absent in the filtered air and WS groups, but enhanced by twofold in the bronchoalveolar lavage of the CW compared with CS group as measured by neutrophil numbers and levels of the neutrophil chemoattractant, keratinocyte-derived chemokine. The levels of the anti-inflammatory lipoxin, lipoxin A4, were reduced by threefold along with cyclo-oxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 in airway epithelial cells and PGE2 levels in the bronchoalveolar lavage of CW compared with CS mice. We replicated, in primary human airway epithelial cells, the changes observed in mice. Immunoprecipitations showed that WS blocked the interaction of aryl hydrocarbon receptor (AHR) with AHR nuclear transporter to reduce expression of COX-2 and mPGES-1 by increasing expression of AHR repressor (AHRR). Collectively, these studies show that exposure to low concentrations of WS enhanced CS-induced inflammation by inducing AHRR expression to suppress AHR, COX-2, and mPGES-1 expression, and levels of PGE2 and lipoxin A4. Therefore, AHRR is a potential therapeutic target for WS-associated exacerbations of CS-induced inflammation. PMID:25137396

  18. Wood Smoke Enhances Cigarette Smoke–Induced Inflammation by Inducing the Aryl Hydrocarbon Receptor Repressor in Airway Epithelial Cells

    PubMed Central

    Awji, Elias G.; Chand, Hitendra; Bruse, Shannon; Smith, Kevin R.; Colby, Jennifer K.; Mebratu, Yohannes; Levy, Bruce D.

    2015-01-01

    Our previous studies showed that cigarette smokers who are exposed to wood smoke (WS) are at an increased risk for chronic bronchitis and reduced lung function. The present study was undertaken to determine the mechanisms for WS-induced adverse effects. We studied the effect of WS exposure using four cohorts of mice. C57Bl/6 mice were exposed for 4 or 12 weeks to filtered air, to 10 mg/m3 WS for 2 h/d, to 250 mg/m3 cigarette smoke (CS) for 6 h/d, or to CS followed by WS (CW). Inflammation was absent in the filtered air and WS groups, but enhanced by twofold in the bronchoalveolar lavage of the CW compared with CS group as measured by neutrophil numbers and levels of the neutrophil chemoattractant, keratinocyte-derived chemokine. The levels of the anti-inflammatory lipoxin, lipoxin A4, were reduced by threefold along with cyclo-oxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 in airway epithelial cells and PGE2 levels in the bronchoalveolar lavage of CW compared with CS mice. We replicated, in primary human airway epithelial cells, the changes observed in mice. Immunoprecipitations showed that WS blocked the interaction of aryl hydrocarbon receptor (AHR) with AHR nuclear transporter to reduce expression of COX-2 and mPGES-1 by increasing expression of AHR repressor (AHRR). Collectively, these studies show that exposure to low concentrations of WS enhanced CS-induced inflammation by inducing AHRR expression to suppress AHR, COX-2, and mPGES-1 expression, and levels of PGE2 and lipoxin A4. Therefore, AHRR is a potential therapeutic target for WS-associated exacerbations of CS-induced inflammation. PMID:25137396

  19. Cr(VI)-stimulated STAT3 tyrosine phosphorylation and nuclear translocation in human airway epithelial cells requires Lck

    PubMed Central

    O'hara, Kimberley A.; Vaghjiani, Rasilaben J.; Nemec, Antonia A.; Klei, Linda R.; Barchowsky, Aaron

    2006-01-01

    Chronic inhalation of low amounts of Cr(VI) promotes pulmonary diseases and cancers through poorly defined mechanisms. SFKs (Src family kinases) in pulmonary airway cells may mediate Cr(VI) signalling for lung injury, although the downstream effectors of Cr(VI)-stimulated SFKs and how they relate to pathogenic gene induction are unknown. Therefore SFK-dependent activation of transcription factors by non-cytotoxic exposure of human bronchial epithelial cells to Cr(VI) was determined. Protein–DNA binding arrays demonstrated that exposing BEAS 2B cells to 5 μM Cr(VI) for 4 and 24 h resulted in increased protein binding to 25 and 43 cis-elements respectively, while binding to 12 and 16 cis-elements decreased. Of note, Cr(VI) increased protein binding to several STAT (signal transducer and activator of transcription) cis-elements. Cr(VI) stimulated acute tyrosine phosphorylation and nuclear translocation of STAT1 over a 4 h period and a prolonged activation of STAT3 that reached a peak between 48 and 72 h. This prolonged activation was observed for both STAT3α and STAT3β. Immunofluorescent confocal microscopy confirmed that Cr(VI) increased nuclear localization of phosphorylated STAT3 for more than 72 h in both primary and BEAS 2B human airway cells. Cr(VI) induced transactivation of both a STAT3-driven luciferase reporter construct and the endogenous inflammatory gene IL-6 (interleukin-6). Inhibition with siRNA (small interfering RNA) targeting the SFK Lck, but not dominant-negative JAK (Janus kinase), prevented Cr(VI)-stimulated phosphorylation of both STAT3 isoforms and induction of IL-6. The results suggest that Cr(VI) activates epithelial cell Lck to signal for prolonged STAT3 activation and transactivation of IL-6, an important immunomodulator of lung disease progression. PMID:17078813

  20. Essential ions for maintenance of the corneal epithelial surface.

    PubMed

    Bachman, W G; Wilson, G

    1985-11-01

    It is generally believed that tears are required to furnish only oxygen to the corneal epithelium. However, as tears are a very complicated solution, it is likely that other factors are essential to the cells of the corneal surface. The amount of light scattered from the epithelial surface of the excised rabbit cornea was examined with the in vitro specular microscope while the epithelium was bathed in different solutions. It was shown that the epithelial surface was maintained best with a buffered solution containing potassium, calcium, magnesium, phosphate and bicarbonate, in addition to sodium chloride. The solution was named Basic Tear Solution (BTS). The effect was not due to osmolarity. Potassium was particularly important, as corneas bathed with sodium chloride and potassium chloride were maintained better than corneas bathed with sodium chloride only. The appearance of the epithelial surface was different in these bathing solutions. In sodium chloride the surface scattered more light and more cells were sloughed. Least light was scattered in BTS, and cell-sloughing was at a minimum. Thus, the rate at which cells were sloughed from the epithelial surface and the quality of the surface were dependent on the bathing solution. PMID:2414247

  1. Gefitinib, an EGFR Tyrosine Kinase inhibitor, Prevents Smoke-Mediated Ciliated Airway Epithelial Cell Loss and Promotes Their Recovery.

    PubMed

    Valencia-Gattas, Monica; Conner, Gregory E; Fregien, Nevis L

    2016-01-01

    Cigarette smoke exposure is a major health hazard. Ciliated cells in the epithelium of the airway play a critical role in protection against the noxious effects of inhaled cigarette smoke. Ciliated cell numbers are reduced in smokers which weakens host defense and leads to disease. The mechanisms for the loss of ciliated cells are not well understood. The effects of whole cigarette smoke exposure on human airway ciliated ciliated cells were examined using in vitro cultures of normal human bronchial epithelial cells and a Vitrocell® VC 10® Smoking Robot. These experiments showed that whole cigarette smoke causes the loss of differentiated ciliated cells and inhibits differentiation of ciliated cells from undifferentiated basal cells. Furthermore, treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, Gefitinib, during smoke exposure prevents ciliated cell loss and promotes ciliated cell differentiation from basal cells. Finally, restoration of ciliated cells was inhibited after smoke exposure was ceased but was enhanced by Gefitinib treatment. These data suggest that inhibition of EGFR activity may provide therapeutic benefit for treating smoke related diseases. PMID:27532261

  2. Gefitinib, an EGFR Tyrosine Kinase inhibitor, Prevents Smoke-Mediated Ciliated Airway Epithelial Cell Loss and Promotes Their Recovery

    PubMed Central

    Valencia-Gattas, Monica; Conner, Gregory E.; Fregien, Nevis L.

    2016-01-01

    Cigarette smoke exposure is a major health hazard. Ciliated cells in the epithelium of the airway play a critical role in protection against the noxious effects of inhaled cigarette smoke. Ciliated cell numbers are reduced in smokers which weakens host defense and leads to disease. The mechanisms for the loss of ciliated cells are not well understood. The effects of whole cigarette smoke exposure on human airway ciliated ciliated cells were examined using in vitro cultures of normal human bronchial epithelial cells and a Vitrocell® VC 10® Smoking Robot. These experiments showed that whole cigarette smoke causes the loss of differentiated ciliated cells and inhibits differentiation of ciliated cells from undifferentiated basal cells. Furthermore, treatment with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, Gefitinib, during smoke exposure prevents ciliated cell loss and promotes ciliated cell differentiation from basal cells. Finally, restoration of ciliated cells was inhibited after smoke exposure was ceased but was enhanced by Gefitinib treatment. These data suggest that inhibition of EGFR activity may provide therapeutic benefit for treating smoke related diseases. PMID:27532261

  3. In vitro determinants of asbestos fiber toxicity: effect on the relative toxicity of Libby amphibole in primary human airway epithelial cells

    PubMed Central

    2014-01-01

    Background An abnormally high incidence of lung disease has been observed in the residents of Libby, Montana, which has been attributed to occupational and environmental exposure to fibrous amphiboles originating from a nearby contaminated vermiculite mine. The composition of Libby amphibole (LA) is complex and minimal toxicity data are available. In this study, we conduct a comparative particle toxicity analysis of LA compared with standard reference asbestiform amphibole samples. Methods Primary human airway epithelial cells (HAEC) were exposed to two different LA samples as well as standard amphibole reference samples. Analysis of the samples included a complete particle size distribution analysis, calculation of surface area by electron microscopy and by gas adsorption and quantification of surface-conjugated iron and hydroxyl radical production by the fibers. Interleukin-8 mRNA levels were quantified by qRT-PCR to measure relative pro-inflammatory response induced in HAEC in response to amphibole fiber exposure. The relative contribution of key physicochemical determinants on the observed pro-inflammatory response were also evaluated. Results The RTI amosite reference sample contained the longest fibers and demonstrated the greatest potency at increasing IL-8 transcript levels when evaluated on an equal mass basis. The two LA samples and the UICC amosite reference sample consisted of similar particle numbers per milligram as well as similar particle size distributions and induced comparable levels of IL-8 mRNA. A strong correlation was observed between the elongated particle (aspect ratio ≥3:1) dose metrics of length and external surface area. Expression of the IL-8 data with respect to either of these metrics eliminated the differential response between the RTI amosite sample and the other samples that was observed when HAEC were exposed on an equal mass basis. Conclusions On an equal mass basis, LA is as potent as the UICC amosite reference sample at

  4. Involvement of the MAPK and PI3K pathways in chitinase 3-like 1-regulated hyperoxia-induced airway epithelial cell death

    SciTech Connect

    Kim, Mi Na; Lee, Kyung Eun; Hong, Jung Yeon; Heo, Won Il; Kim, Kyung Won; Kim, Kyu Earn; Sohn, Myung Hyun

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Hyperoxia induces apoptosis and chitinase 3-like 1 expression in human airway epithelial cells. Black-Right-Pointing-Pointer Presence of chitinase 3-like 1 affects airway epithelial cell death after hyperoxic exposure. Black-Right-Pointing-Pointer Silencing chitinase 3-like 1 manipulate the phosphorylation of ERK, p38 and Akt. -- Abstract: Background: Exposure to 100% oxygen causes hyperoxic acute lung injury characterized by cell death and injury of alveolar epithelial cells. Recently, the role of chitinase 3-like 1 (CHI3L1), a member of the glycosyl hydrolase 18 family that lacks chitinase activity, in oxidative stress was demonstrated in murine models. High levels of serum CHI3L1 have been associated with various diseases of the lung, such as asthma, chronic obstructive pulmonary disease, and cancer. However, the role of CHI3L1 in human airway epithelial cells undergoing oxidative stress remains unknown. In addition, the signaling pathways associated with CHI3L1 in this process are poorly understood. Purpose: In this study, we demonstrate the role of CHI3L1, along with the MAPK and PI3K signaling pathways, in hyperoxia-exposed airway epithelial cells. Method: The human airway epithelial cell line, BEAS-2B, was exposed to >95% oxygen (hyperoxia) for up to 72 h. Hyperoxia-induced cell death was determined by assessing cell viability, Annexin-V FITC staining, caspase-3 and -7 expression, and electron microscopy. CHI3L1 knockdown and overexpression studies were conducted in BEAS-2B cells to examine the role of CHI3L1 in hyperoxia-induced apoptosis. Activation of the MAPK and PI3K pathways was also investigated to determine the role of these signaling cascades in this process. Results: Hyperoxia exposure increased CHI3L1 expression and apoptosis in a time-dependent manner. CHI3L1 knockdown protected cells from hyperoxia-induced apoptosis. In contrast, CHI3L1 overexpression promoted cell death after hyperoxia exposure. Finally

  5. Model of ion transport regulation in chloride-secreting airway epithelial cells. Integrated description of electrical, chemical, and fluorescence measurements.

    PubMed Central

    Hartmann, T; Verkman, A S

    1990-01-01

    An electrokinetic model was developed to calculate the time course of electrical parameters, ion fluxes, and intracellular ion activities for experiments performed in airway epithelial cells. Model variables included cell [Na], [K], [Cl], volume, and membrane potentials. The model contained apical membrane Cl, Na, and K conductances, basolateral membrane K conductance, Na/K/2 Cl and Na/Cl symport, and 3 Na/2 K ATPase, and a paracellular conductance. Transporter permeabilities and ion saturabilities were determined from reported ion flux data and membrane potentials in intact canine trachea. Without additional assumptions, the model predicted accurately the measured short-circuit current (Isc), cellular conductances, voltage-divider ratios, open-circuit potentials, and the time course of cell ion composition in ion substitution experiments. The model was used to examine quantitatively: (a) the effect of transport inhibitors on Isc and membrane potentials, (b) the dual role of apical Cl and basolateral K conductance in cell secretion, (c) whether the basolateral symporter requires K, and (d) the regulation of apical Cl conductance by cAMP and Ca-dependent signaling pathways. Model predictions gave improved understanding of the interrelations among transporting systems and in many cases gave surprising predictions that were not obvious without a detailed model. The model developed here has direct application to secretory or absorptive epithelial cells in the kidney thick ascending limb, cornea, sweat duct, and intestine in normal and pathophysiological states such as cystic fibrosis and cholera. PMID:1698471

  6. Failure of cAMP agonists to activate rescued deltaF508 CFTR in CFBE41o- airway epithelial monolayers.

    PubMed

    Bebok, Zsuzsa; Collawn, James F; Wakefield, John; Parker, William; Li, Yao; Varga, Karoly; Sorscher, Eric J; Clancy, J P

    2005-12-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a cyclic AMP-regulated chloride channel. Mutations in the CFTR gene result in cystic fibrosis (CF). The most common mutation, deltaF508, results in endoplasmic reticulum-associated degradation (ERAD) of CFTR. DeltaF508 CFTR has been described as a temperature-sensitive mutation that can be rescued following growth at 27 degrees C. In order to study the processing and function of wild-type and rescued deltaF508 CFTR at the cell surface under non-polarized and polarized conditions, we developed stable cell lines expressing deltaF508 or wild-type CFTR. CFBE41o- is a human airway epithelial cell line capable of forming high resistance, polarized monolayers when cultured on permeable supports, while HeLa cells are normally grown under non-polarizing conditions. Immunoprecipitation, cell surface biotinylation, immunofluorescence, and functional assays confirmed the presence of deltaF508 CFTR at the cell surface in both cell lines after incubating the cells for 48 h at 27 degrees C. However, stimulators of wild-type CFTR such as forskolin, beta2-adrenergic or A2B-adenosine receptor agonists failed to activate rescued deltaF508 CFTR in CFBE41o- monolayers. Rescued deltaF508 CFTR could be stimulated with genistein independent of pretreatment with cAMP signalling agonists. Interestingly, rescued deltaF508 CFTR in HeLa cells could be efficiently stimulated with either forskolin or genistein to promote Cl- transport. These results indicate that deltaF508 CFTR, when rescued in CFBE41o- human airway epithelial cells, is poorly responsive to signalling pathways known to regulate wild-type CFTR. Furthermore, the differences in rescue and activation of deltaF508 CFTR in the two cell lines suggest that cell-type specific differences in deltaF508 CFTR processing are likely to complicate efforts to identify potentiators and/or correctors of the deltaF508 defect. PMID:16210354

  7. Failure of cAMP agonists to activate rescued ΔF508 CFTR in CFBE41o– airway epithelial monolayers

    PubMed Central

    Bebok, Zsuzsa; Collawn, James F; Wakefield, John; Parker, William; Li, Yao; Varga, Karoly; Sorscher, Eric J; Clancy, JP

    2005-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a cyclic AMP-regulated chloride channel. Mutations in the CFTR gene result in cystic fibrosis (CF). The most common mutation, ΔF508, results in endoplasmic reticulum-associated degradation (ERAD) of CFTR. ΔF508 CFTR has been described as a temperature-sensitive mutation that can be rescued following growth at 27°C. In order to study the processing and function of wild-type and rescued ΔF508 CFTR at the cell surface under non-polarized and polarized conditions, we developed stable cell lines expressing ΔF508 or wild-type CFTR. CFBE41o– is a human airway epithelial cell line capable of forming high resistance, polarized monolayers when cultured on permeable supports, while HeLa cells are normally grown under non-polarizing conditions. Immunoprecipitation, cell surface biotinylation, immunofluorescence, and functional assays confirmed the presence of ΔF508 CFTR at the cell surface in both cell lines after incubating the cells for 48 h at 27°C. However, stimulators of wild-type CFTR such as forskolin, β2-adrenergic or A2B-adenosine receptor agonists failed to activate rescued ΔF508 CFTR in CFBE41o– monolayers. Rescued ΔF508 CFTR could be stimulated with genistein independent of pretreatment with cAMP signalling agonists. Interestingly, rescued ΔF508 CFTR in HeLa cells could be efficiently stimulated with either forskolin or genistein to promote Cl– transport. These results indicate that ΔF508 CFTR, when rescued in CFBE41o– human airway epithelial cells, is poorly responsive to signalling pathways known to regulate wild-type CFTR. Furthermore, the differences in rescue and activation of ΔF508 CFTR in the two cell lines suggest that cell-type specific differences in ΔF508 CFTR processing are likely to complicate efforts to identify potentiators and/or correctors of the ΔF508 defect. PMID:16210354

  8. TALENs Facilitate Single-step Seamless SDF Correction of F508del CFTR in Airway Epithelial Submucosal Gland Cell-derived CF-iPSCs.

    PubMed

    Suzuki, Shingo; Sargent, R Geoffrey; Illek, Beate; Fischer, Horst; Esmaeili-Shandiz, Alaleh; Yezzi, Michael J; Lee, Albert; Yang, Yanu; Kim, Soya; Renz, Peter; Qi, Zhongxia; Yu, Jingwei; Muench, Marcus O; Beyer, Ashley I; Guimarães, Alessander O; Ye, Lin; Chang, Judy; Fine, Eli J; Cradick, Thomas J; Bao, Gang; Rahdar, Meghdad; Porteus, Matthew H; Shuto, Tsuyoshi; Kai, Hirofumi; Kan, Yuet W; Gruenert, Dieter C

    2016-01-01

    Cystic fibrosis (CF) is a recessive inherited disease associated with multiorgan damage that compromises epithelial and inflammatory cell function. Induced pluripotent stem cells (iPSCs) have significantly advanced the potential of developing a personalized cell-based therapy for diseases like CF by generating patient-specific stem cells that can be differentiated into cells that repair tissues damaged by disease pathology. The F508del mutation in airway epithelial cell-derived CF-iPSCs was corrected with small/short DNA fragments (SDFs) and sequence-specific TALENs. An allele-specific PCR, cyclic enrichment strategy gave ~100-fold enrichment of the corrected CF-iPSCs after six enrichment cycles that facilitated isolation of corrected clones. The seamless SDF-based gene modification strategy used to correct the CF-iPSCs resulted in pluripotent cells that, when differentiated into endoderm/airway-like epithelial cells showed wild-type (wt) airway epithelial cell cAMP-dependent Cl ion transport or showed the appropriate cell-type characteristics when differentiated along mesoderm/hematopoietic inflammatory cell lineage pathways. PMID:26730810

  9. Transcription Factor Runx3 Is Induced by Influenza A Virus and Double-Strand RNA and Mediates Airway Epithelial Cell Apoptosis

    PubMed Central

    Gan, Huachen; Hao, Qin; Idell, Steven; Tang, Hua

    2015-01-01

    Influenza A virus (IAV) targets airway epithelial cells and exploits the host cell machinery to replicate, causing respiratory illness in annual epidemics and pandemics of variable severity. The high rate of antigenic drift (viral mutation) and the putative antigenic shift (reassortant strains) have raised the need to find the host cell inducible factors modulating IAV replication and its pathogenesis to develop more effective antiviral treatment. In this study, we found for the first time that transcription factor Runx3, a developmental regulator and tumor suppressor, was induced by IAV H1N1 and H3N2, viral RNA, a synthetic analog of viral double-stranded RNA (dsRNA) polyinosinic-polycytidylic acid, and type-II interferon-γ (IFNγ) in human airway epithelial cells. Whereas Runx3 was essentially not induced by type-I IFNα and type-III IFNλ, we show that Runx3 induction by IAV infection and viral RNA is mediated through the innate immune receptor MDA5 and the IκB kinase-β−NF-κB pathway. Moreover, we provide substantial evidence indicating that Runx3 plays a crucial role in airway epithelial cell apoptosis induced by IAV infection and dsRNA through the activation of extrinsic and intrinsic apoptosis pathways. Thus, we have identified Runx3 as an inducible and important transcription factor modulating IAV-induced host epithelial cell apoptosis. PMID:26643317

  10. Use of mucolytics to enhance magnetic particle retention at a model airway surface

    NASA Astrophysics Data System (ADS)

    Ally, Javed; Roa, Wilson; Amirfazli, A.

    A previous study has shown that retention of magnetic particles at a model airway surface requires prohibitively strong magnetic fields. As mucus viscoelasticity is the most significant factor contributing to clearance of magnetic particles from the airway surface, mucolytics are considered in this study to reduce mucus viscoelasticity and enable particle retention with moderate strength magnetic fields. The excised frog palate model was used to simulate the airway surface. Two mucolytics, N-acetylcysteine (NAC) and dextran sulfate (DS) were tested. NAC was found to enable retention at moderate field values (148 mT with a gradient of 10.2 T/m), whereas DS was found to be effective only for sufficiently large particle concentrations at the airway surface. The possible mechanisms for the observed behavior with different mucolytics are also discussed based on aggregate formation and the loading of cilia.

  11. 1α,25-dihydroxyvitamin D₃ counteracts the effects of cigarette smoke in airway epithelial cells.

    PubMed

    Zhang, Ruhui; Zhao, Haijin; Dong, Hangming; Zou, Fei; Cai, Shaoxi

    2015-06-01

    Cigarette smoke extracts (CSE) alter calpain-1 expression via ERK signaling pathway in bronchial epithelial cells. 1α,25-dihydroxyvitamin D3 (1,25D3) inhibits cigarette smoke-induced epithelial barrier disruption. This study was aimed to explore whether the 1,25D3 counteracted the CSE effects in a human bronchial epithelial cell line (16HBE). In particular, transepithelial electrical resistance (TER) and permeability, expression and distribution of E-cadherin and β-catenin, calpain-1 expression, and ERK phosphorylation were assessed in the CSE-stimulated 16HBE cells. The CSE induced the ERK phosphorylation, improved the calpain-1 expression, increased the distribution anomalies and the cleaving of E-cadherin and β-catenin, and resulted in the TER reduction and the permeability increase. The 1,25D3 reduced these pathological changes. The 1,25D3 mediated effects were associated with a reduced ERK phosphorylation. In conclusion, the present study provides compelling evidences that the 1,25D3 may be considered a possible valid therapeutic option in controlling the cigarette smoke-induced epithelial barrier disruption. PMID:25880105

  12. Novel antiviral properties of azithromycin in cystic fibrosis airway epithelial cells.

    PubMed

    Schögler, Aline; Kopf, Brigitte S; Edwards, Michael R; Johnston, Sebastian L; Casaulta, Carmen; Kieninger, Elisabeth; Jung, Andreas; Moeller, Alexander; Geiser, Thomas; Regamey, Nicolas; Alves, Marco P

    2015-02-01

    Virus-associated pulmonary exacerbations, often associated with rhinoviruses (RVs), contribute to cystic fibrosis (CF) morbidity. Currently, there are only a few therapeutic options to treat virus-induced CF pulmonary exacerbations. The macrolide antibiotic azithromycin has antiviral properties in human bronchial epithelial cells. We investigated the potential of azithromycin to induce antiviral mechanisms in CF bronchial epithelial cells. Primary bronchial epithelial cells from CF and control children were infected with RV after azithromycin pre-treatment. Viral RNA, interferon (IFN), IFN-stimulated gene and pattern recognition receptor expression were measured by real-time quantitative PCR. Live virus shedding was assessed by assaying the 50% tissue culture infective dose. Pro-inflammatory cytokine and IFN-β production were evaluated by ELISA. Cell death was investigated by flow cytometry. RV replication was increased in CF compared with control cells. Azithromycin reduced RV replication seven-fold in CF cells without inducing cell death. Furthermore, azithromycin increased RV-induced pattern recognition receptor, IFN and IFN-stimulated gene mRNA levels. While stimulating antiviral responses, azithromycin did not prevent virus-induced pro-inflammatory responses. Azithromycin pre-treatment reduces RV replication in CF bronchial epithelial cells, possibly through the amplification of the antiviral response mediated by the IFN pathway. Clinical studies are needed to elucidate the potential of azithromycin in the management and prevention of RV-induced CF pulmonary exacerbations. PMID:25359346

  13. ACTIVATION OF THE EGF RECEPTOR SIGNALING PATHWAY IN HUMAN AIRWAY EPITHELIAL CELLS EXPOSED TO METALS

    EPA Science Inventory

    We have previously shown that exposure to combustion-derived metals rapidly (within 20 min) activated mitogen-activated protein kinases (MAPK), including extracellular signal-regulated kinase (ERK), in the human bronchial epithelial cell line BEAS. To study the mechanisms respons...

  14. Efficient intratracheal delivery of airway epithelial cells in mice and pigs.

    PubMed

    Gui, Liqiong; Qian, Hong; Rocco, Kevin A; Grecu, Loreta; Niklason, Laura E

    2015-01-15

    Cellular therapy via direct intratracheal delivery has gained interest as a novel therapeutic strategy for treating various pulmonary diseases including cystic fibrosis lung disease. However, concerns such as insufficient cell engraftment in lungs and lack of large animal model data remain to be resolved. This study aimed to establish a simple method for evaluating cell retention in lungs and to develop reproducible approaches for efficient cell delivery into mouse and pig lungs. Human lung epithelial cells including normal human bronchial/tracheal epithelial (NHBE) cells and human lung epithelial cell line A549 were infected with pSicoR-green fluorescent protein (GFP) lentivirus. GFP-labeled NHBE cells were delivered via a modified intratracheal cell instillation method into the lungs of C57BL/6J mice. Two days following cell delivery, GFP ELISA-based assay revealed a substantial cell-retention efficiency (10.48 ± 2.86%, n = 7) in mouse lungs preinjured with 2% polidocanol. When GFP-labeled A549 cells were transplanted into Yorkshire pig lungs with a tracheal intubation fiberscope, a robust initial cell attachment (22.32% efficiency) was observed at 24 h. In addition, a lentiviral vector was developed to induce the overexpression and apical localization of cystic fibrosis transmembrane conductance regulator (CFTR)-GFP fusion proteins in NHBE cells as a means of ex vivo CFTR gene transfer in nonprogenitor (relatively differentiated) lung epithelial cells. These results have demonstrated the convenience and efficiency of direct delivery of exogenous epithelial cells to lungs in mouse and pig models and provided important background for future preclinical evaluation of intratracheal cell transplantation to treat lung diseases. PMID:25416381

  15. Cell Surface Human Airway Trypsin-Like Protease Is Lost During Squamous Cell Carcinogenesis

    PubMed Central

    DUHAIME, MICHAEL J.; PAGE, KHALIPH O.; VARELA, FAUSTO A.; MURRAY, ANDREW S.; SILVERMAN, MICHAEL E.; ZORATTI, GINA L.; LIST, KARIN

    2016-01-01

    Cancer progression is accompanied by increased levels of extracellular proteases that are capable of remodeling the extracellular matrix, as well as cleaving and activating growth factors and receptors that are involved in pro-cancerous signaling pathways. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression, however, the expression or function of the TTSP Human Airway Trypsin-like protease (HAT) in carcinogenesis has not been examined. In the present study we aimed to determine the expression of HAT during squamous cell carcinogenesis. HAT transcript is present in several tissues containing stratified squamous epithelium and decreased expression is observed in carcinomas. We determined that HAT protein is consistently expressed on the cell surface in suprabasal/apical layers of squamous cells in healthy cervical and esophageal epithelia. To assess whether HAT protein is differentially expressed in normal tissue versus tissue in different stages of carcinogenesis, we performed a comprehensive immunohistochemical analysis of HAT protein expression levels and localization in arrays of paraffin embedded human cervical and esophageal carcinomas compared to the corresponding normal tissue. We found that HAT protein is expressed in the non-proliferating, differentiated cellular strata and is lost during the dedifferentiation of epithelial cells, a hallmark of squamous cell carcinogenesis. Thus, HAT expression may potentially be useful as a marker for clinical grading and assessment of patient prognosis in squamous cell carcinomas. PMID:26297835

  16. Cell Surface Human Airway Trypsin-Like Protease Is Lost During Squamous Cell Carcinogenesis.

    PubMed

    Duhaime, Michael J; Page, Khaliph O; Varela, Fausto A; Murray, Andrew S; Silverman, Michael E; Zoratti, Gina L; List, Karin

    2016-07-01

    Cancer progression is accompanied by increased levels of extracellular proteases that are capable of remodeling the extracellular matrix, as well as cleaving and activating growth factors and receptors that are involved in pro-cancerous signaling pathways. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression, however, the expression or function of the TTSP Human Airway Trypsin-like protease (HAT) in carcinogenesis has not been examined. In the present study we aimed to determine the expression of HAT during squamous cell carcinogenesis. HAT transcript is present in several tissues containing stratified squamous epithelium and decreased expression is observed in carcinomas. We determined that HAT protein is consistently expressed on the cell surface in suprabasal/apical layers of squamous cells in healthy cervical and esophageal epithelia. To assess whether HAT protein is differentially expressed in normal tissue versus tissue in different stages of carcinogenesis, we performed a comprehensive immunohistochemical analysis of HAT protein expression levels and localization in arrays of paraffin embedded human cervical and esophageal carcinomas compared to the corresponding normal tissue. We found that HAT protein is expressed in the non-proliferating, differentiated cellular strata and is lost during the dedifferentiation of epithelial cells, a hallmark of squamous cell carcinogenesis. Thus, HAT expression may potentially be useful as a marker for clinical grading and assessment of patient prognosis in squamous cell carcinomas. PMID:26297835

  17. Surface modeling and segmentation of the 3D airway wall in MSCT

    NASA Astrophysics Data System (ADS)

    Ortner, Margarete; Fetita, Catalin; Brillet, Pierre-Yves; Pr"teux, Françoise; Grenier, Philippe

    2011-03-01

    Airway wall remodeling in asthma and chronic obstructive pulmonary disease (COPD) is a well-known indicator of the pathology. In this context, current clinical studies aim for establishing the relationship between the airway morphological structure and its function. Multislice computed tomography (MSCT) allows morphometric assessment of airways, but requires dedicated segmentation tools for clinical exploitation. While most of the existing tools are limited to cross-section measurements, this paper develops a fully 3D approach for airway wall segmentation. Such approach relies on a deformable model which is built up as a patient-specific surface model at the level of the airway lumen and deformed to reach the outer surface of the airway wall. The deformation dynamics obey a force equilibrium in a Lagrangian framework constrained by a vector field which avoids model self-intersections. The segmentation result allows a dense quantitative investigation of the airway wall thickness with a deeper insight at bronchus subdivisions than classic cross-section methods. The developed approach has been assessed both by visual inspection of 2D cross-sections, performed by two experienced radiologists on clinical data obtained with various protocols, and by using a simulated ground truth (pulmonary CT image model). The results confirmed a robust segmentation in intra-pulmonary regions with an error in the range of the MSCT image resolution and underlined the interest of the volumetric approach versus purely 2D methods.

  18. Characterization of Nipah virus infection in a model of human airway epithelial cells cultured at an air-liquid interface.

    PubMed

    Escaffre, Olivier; Borisevich, Viktoriya; Vergara, Leoncio A; Wen, Julie W; Long, Dan; Rockx, Barry

    2016-05-01

    Nipah virus (NiV) is an emerging paramyxovirus that can cause lethal respiratory illness in humans. No vaccine/therapeutic is currently licensed for humans. Human-to-human transmission was previously reported during outbreaks and NiV could be isolated from respiratory secretions, but the proportion of cases in Malaysia exhibiting respiratory symptoms was significantly lower than that in Bangladesh. Previously, we showed that primary human basal respiratory epithelial cells are susceptible to both NiV-Malaysia (M) and -Bangladesh (B) strains causing robust pro-inflammatory responses. However, the cells of the human respiratory epithelium that NiV targets are unknown and their role in NiV transmission and NiV-related lung pathogenesis is still poorly understood. Here, we characterized NiV infection of the human respiratory epithelium using a model of the human tracheal/bronchial (B-ALI) and small airway (S-ALI) epithelium cultured at an air-liquid interface. We show that NiV-M and NiV-B infect ciliated and secretory cells in B/S-ALI, and that infection of S-ALI, but not B-ALI, results in disruption of the epithelium integrity and host responses recruiting human immune cells. Interestingly, NiV-B replicated more efficiently in B-ALI than did NiV-M. These results suggest that the human tracheal/bronchial epithelium is favourable to NiV replication and shedding, while inducing a limited host response. Our data suggest that the small airways epithelium is prone to inflammation and lesions as well as constituting a point of virus entry into the pulmonary vasculature. The use of relevant models of the human respiratory tract, such as B/S-ALI, is critical for understanding NiV-related lung pathogenesis and identifying the underlying mechanisms allowing human-to-human transmission. PMID:26932515

  19. An innate antiviral pathway acting before interferons at epithelial surfaces.

    PubMed

    Iversen, Marie B; Reinert, Line S; Thomsen, Martin K; Bagdonaite, Ieva; Nandakumar, Ramya; Cheshenko, Natalia; Prabakaran, Thaneas; Vakhrushev, Sergey Y; Krzyzowska, Malgosha; Kratholm, Sine K; Ruiz-Perez, Fernando; Petersen, Steen V; Goriely, Stanislas; Bibby, Bo Martin; Eriksson, Kristina; Ruland, Jürgen; Thomsen, Allan R; Herold, Betsy C; Wandall, Hans H; Frische, Sebastian; Holm, Christian K; Paludan, Søren R

    2016-02-01

    Mucosal surfaces are exposed to environmental substances and represent a major portal of entry for microorganisms. The innate immune system is responsible for early defense against infections and it is believed that the interferons (IFNs) constitute the first line of defense against viruses. Here we identify an innate antiviral pathway that works at epithelial surfaces before the IFNs. The pathway is activated independently of known innate sensors of viral infections through a mechanism dependent on viral O-linked glycans, which induce CXCR3 chemokines and stimulate antiviral activity in a manner dependent on neutrophils. This study therefore identifies a previously unknown layer of antiviral defense that exerts its action on epithelial surfaces before the classical IFN response is operative. PMID:26595890

  20. Modulation of airway epithelial cell functions by Pidotimod: NF-kB cytoplasmatic expression and its nuclear translocation are associated with an increased TLR-2 expression

    PubMed Central

    2013-01-01

    Background Recurrent respiratory infections are one of the most important causes of morbidity in childhood. When immune functions are still largely immature, the airway epithelium plays a primary defensive role since, besides providing a physical barrier, it is also involved in the innate and the adaptive immune responses. A study was therefore designed to evaluate in vitro whether pidotimod, a synthetic dipeptide able to stimulate the inflammatory and immune effector cells, could activate bronchial epithelial cell functions involved in response to infections. Methods BEAS-2B cell line (human bronchial epithelial cells infected with a replication-defective Adenovirus 12-SV40 virus hybrid) were cultured in the presence of pidotimod, with or without tumor necrosis factor (TNF)-α or zymosan to assess: a) intercellular adhesion molecule (ICAM)-1 expression, by flow cytometry; b) toll-like receptor (TLR)-2 expression and production, by immunofluorescence flow cytometry and western blotting; d) interleukin (IL)-8 release, by enzyme-linked immunosorbent assay (ELISA); e) activated extracellular-signal-regulated kinase (ERK1/2) phosphorylation and nuclear factor-kappa B (NF-kB) activation, by western blotting. Results The constitutive expression of ICAM-1 and IL-8 release were significant up-regulated by TNF-α (ICAM-1) and by TNF-α and zymosan (IL-8), but not by pidotimod. In contrast, an increased TLR-2 expression was found after exposure to pidotimod 10 and 100 μg/ml (p < 0.05) and to the association pidotimod 100 μg/ml + TNF-α (p < 0.05). Western blot analysis substantiated that the constitutive TLR-2 expression was significantly increased after exposure to all the stimuli. Finally, while a remarkable inhibition of TNF-α -induced ERK1/2 phosphorylation was observed in the presence of pidotimod, both TNF-α and pidotimod were effective in inducing NF-kB protein expression in the cytoplasm and its nuclear translocation. Conclusion Through different

  1. Alternaria-Induced Release of IL-18 from Damaged Airway Epithelial Cells: An NF-κB Dependent Mechanism of Th2 Differentiation?

    PubMed Central

    Wild, Jim; Dharajiya, Nilesh; Vaidya, Swapnil; Kalita, Anjana; Bacsi, Attila; Corry, David; Kurosky, Alexander; Brasier, Allan; Boldogh, Istvan; Sur, Sanjiv

    2012-01-01

    Background A series of epidemiologic studies have identified the fungus Alternaria as a major risk factor for asthma. The airway epithelium plays a critical role in the pathogenesis of allergic asthma. These reports suggest that activated airway epithelial cells can produce cytokines such as IL-25, TSLP and IL-33 that induce Th2 phenotype. However the epithelium-derived products that mediate the pro-asthma effects of Alternaria are not well characterized. We hypothesized that exposure of the airway epithelium to Alternaria releasing cytokines that can induce Th2 differentiation. Methodology/Principal Finding We used ELISA to measure human and mouse cytokines. Alternaria extract (ALT-E) induced rapid release of IL-18, but not IL-4, IL-9, IL-13, IL-25, IL-33, or TSLP from cultured normal human bronchial epithelial cells; and in the BAL fluids of naïve mice after challenge with ALT-E. Both microscopic and FACS indicated that this release was associated with necrosis of epithelial cells. ALT-E induced much greater IL-18 release compared to 19 major outdoor allergens. Culture of naïve CD4 cells with rmIL-18 induced Th2 differentiation in the absence of IL-4 and STAT6, and this effect was abrogated by disrupting NF- κB p50 or with a NEMO binding peptide inhibitor. Conclusion/Significance Rapid and specific release of IL-18 from Alternaria-exposed damaged airway epithelial cells can directly initiate Th2 differentiation of naïve CD4+ T-cells via a unique NF-κB dependent pathway. PMID:22347372

  2. Bicarbonate and chloride secretion in Calu-3 human airway epithelial cells.

    PubMed

    Devor, D C; Singh, A K; Lambert, L C; DeLuca, A; Frizzell, R A; Bridges, R J

    1999-05-01

    Serous cells are the predominant site of cystic fibrosis transmembrane conductance regulator expression in the airways, and they make a significant contribution to the volume, composition, and consistency of the submucosal gland secretions. We have employed the human airway serous cell line Calu-3 as a model system to investigate the mechanisms of serous cell anion secretion. Forskolin-stimulated Calu-3 cells secrete HCO-3 by a Cl-offdependent, serosal Na+-dependent, serosal bumetanide-insensitive, and serosal 4,4'-dinitrostilben-2,2'-disulfonic acid (DNDS)-sensitive, electrogenic mechanism as judged by transepithelial currents, isotopic fluxes, and the results of ion substitution, pharmacology, and pH studies. Similar studies revealed that stimulation of Calu-3 cells with 1-ethyl-2-benzimidazolinone (1-EBIO), an activator of basolateral membrane Ca2+-activated K+ channels, reduced HCO-3 secretion and caused the secretion of Cl- by a bumetanide-sensitive, electrogenic mechanism. Nystatin permeabilization of Calu-3 monolayers demonstrated 1-EBIO activated a charybdotoxin- and clotrimazole- inhibited basolateral membrane K+ current. Patch-clamp studies confirmed the presence of an intermediate conductance inwardly rectified K+ channel with this pharmacological profile. We propose that hyperpolarization of the basolateral membrane voltage elicits a switch from HCO-3 secretion to Cl- secretion because the uptake of HCO-3 across the basolateral membrane is mediated by a 4,4 '-dinitrostilben-2,2'-disulfonic acid (DNDS)-sensitive Na+:HCO-3 cotransporter. Since the stoichiometry reported for Na+:HCO-3 cotransport is 1:2 or 1:3, hyperpolarization of the basolateral membrane potential by 1-EBIO would inhibit HCO-3 entry and favor the secretion of Cl-. Therefore, differential regulation of the basolateral membrane K+ conductance by secretory agonists could provide a means of stimulating HCO-3 and Cl- secretion. In this context, cystic fibrosis transmembrane conductance

  3. Synergistic and additive killing by antimicrobial factors found in human airway surface liquid.

    PubMed

    Singh, P K; Tack, B F; McCray, P B; Welsh, M J

    2000-11-01

    Airway surface liquid contains multiple factors thought to provide a first line of defense against bacteria deposited in the airways. Although the antimicrobial action of individual factors has been studied, less is known about how they work in combination. We examined the combined action of six antimicrobial peptides found in airway surface liquid. The paired combinations of lysozyme-lactoferrin, lysozyme-secretory leukocyte protease inhibitor (SLPI), and lactoferrin-SLPI were synergistic. The triple combination of lysozyme, lactoferrin, and SLPI showed even greater synergy. Other combinations involving the human beta-defensins, LL-37, and tobramycin (often administered to cystic fibrosis patients by inhalation) were additive. Because the airway surface liquid salt concentration may be elevated in cystic fibrosis patients, we examined the effect of salt on the synergistic combinations. As the ionic strength increased, synergistic interactions were lost. Our data suggest that the antibacterial potency of airway surface liquid may be significantly increased by synergistic and additive interactions between antimicrobial factors. These results also suggest that increased salt concentrations that may exist in cystic fibrosis could inhibit airway defenses by diminishing these synergistic interactions. PMID:11053013

  4. The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing

    NASA Astrophysics Data System (ADS)

    Zabner, Joseph; Seiler, Michael P.; Launspach, Janice L.; Karp, Philip H.; Kearney, William R.; Look, Dwight C.; Smith, Jeffrey J.; Welsh, Michael J.

    2000-10-01

    The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface.

  5. Vulnerability of the human airway epithelium to hyperoxia. Constitutive expression of the catalase gene in human bronchial epithelial cells despite oxidant stress.

    PubMed

    Yoo, J H; Erzurum, S C; Hay, J G; Lemarchand, P; Crystal, R G

    1994-01-01

    Although catalase is a major intracellular antioxidant, the expression of the human catalase gene appears to be limited in the airway epithelium, making these cells vulnerable to oxidant stress. The basis for this limited gene expression was examined by evaluation of the expression of the endogenous gene in human bronchial epithelial cells in response to hyperoxia. Hyperoxia failed to upregulate endogenous catalase gene expression, in contrast to a marked increase in expression of the heat shock protein gene. Sequence analysis of 1.7 kb of the 5'-flanking region of the human catalase gene showed features of a "house-keeping" gene (no TATA box, high GC content, multiple CCAAT boxes, and transcription start sites). Transfection of human bronchial epithelial cells with fusion genes composed of various lengths of the catalase 5'-flanking region and luciferase as a reporter gene showed low level constitutive promoter activity that did not change after exposure to hyperoxia. Importantly, using a replication-deficient recombinant adenoviral vector containing the human catalase cDNA, levels of catalase were significantly increased in human airway epithelial cells and this was associated with increased survival of the cells when exposed to hyperoxia. These observations provide a basis for understanding the sensitivity of the human airway epithelium to oxidant stress and a strategy for protecting the epithelium from such injury. PMID:8282800

  6. Challenge for 3D culture technology: Application in carcinogenesis studies with human airway epithelial cells.

    PubMed

    Emura, M; Aufderheide, M

    2016-05-01

    Lung cancer is still one of the major intractable diseases and we urgently need more efficient preventive and curative measures. Recent molecular studies have provided strong evidence that allows us to believe that classically well-known early airway lesions such as hyperplasia, metaplasia, dysplasia and carcinoma in situ are really precancerous lesions progressing toward cancer but not necessarily transient and reversible alteration. This suggests that adequate early control of the precancerous lesions may lead to improved prevention of lung cancer. This knowledge is encouraging in view of the imminent necessity for additional experimental systems to investigate the causal mechanisms of cancers directly in human cells and tissues. There are many questions with regard to various precancerous lesions of the airways. For example, should cells, before reaching a stage of invasive carcinoma, undergo all precancerous stages such as hyperplasia or metaplasia and dysplasia, or is there any shortcut to bypass one or more of the precancerous stages? For the study of such questions, the emerging 3-dimensional (3D) cell culture technology appears to provide an effective and valuable tool. Though a great challenge, it is expected that this in vitro technology will be rapidly and reliably improved to enable the cultures to be maintained in an in vivo-mimicking state of differentiation for much longer than a period of at best a few months, as is currently the case. With the help of a "causes recombination-Lox" (Cre-lox) technology, it has been possible to trace cells giving rise to specific lung tumor types. In this short review we have attempted to assess the future role of 3D technology in the study of lung carcinogenesis. PMID:26951634

  7. Enhanced detection of bladder cancer using the epithelial surface marker epithelial membrane antigen: a preliminary report.

    PubMed

    Ring, K S; Karp, F; Benson, M C

    1990-09-01

    The flow cytometry (FCM) technique allows for the rapid quantitative analysis of the DNA content of individual cells. In a variety of genitourinary tumors, DNA ploidy has a significant impact upon prognosis and ultimate patient survival. In patients having transitional cell cancer (TCC) of the bladder, FCM of voided urine and bladder barbotage specimens is highly correlated with cytologic analysis in the detection of malignant cells. One problem with this technique has been decreased sensitivity in samples containing large numbers of inflammatory cells. To improve FCM detection of TCC in bladder wash specimens, we developed a technique using a monoclonal antibody (Mab) specific to human, epithelial membrane antigen (EMA). The EMA cell-surface marker enabled us to differentiate bladder epithelial cells from lymphocytes and cellular debris. In combination with DNA analysis using propidium iodide, the EMA Mab increased the sensitivity and specificity of FCM compared to conventional analysis using propidium iodide alone. We conclude that epithelial cell-surface antigen staining using both EMA Mab and DNA staining can increase the FCM detection of TCC in bladder wash specimens. PMID:2074517

  8. Targeted gene delivery to human airway epithelial cells with synthetic vectors incorporating novel targeting peptides selected by phage display.

    PubMed

    Writer, Michele J; Marshall, Barry; Pilkington-Miksa, Michael A; Barker, Susie E; Jacobsen, Marianne; Kritz, Angelika; Bell, Paul C; Lester, Douglas H; Tabor, Alethea B; Hailes, Helen C; Klein, Nigel; Hart, Stephen L

    2004-05-01

    Human airway epithelial cell targeting peptides were identified by biopanning on 1HAEo-cells, a well characterised epithelial cell line. Bound phage were recovered after three rounds of binding, high stringency washing and elution, leading to the production of an enriched phage peptide population. DNA sequencing of 56 clones revealed 14 unique sequences. Subsequent binding analysis revealed that 13 of these peptides bound 1HAEo-cells with high affinity. Three peptides, SERSMNF, YGLPHKF and PSGAARA were represented at high frequency. Three clearly defined families of peptide were identified on the basis of sequence motifs including (R/K)SM, L(P/Q)HK and PSG(A/T)ARA. Two peptides, LPHKSMP and LQHKSMP contained two motifs. Further detailed sequence analysis by comparison of peptide sequences with the SWISSPROT protein database revealed that some of the peptides closely resembled the cell binding proteins of viral and bacterial pathogens including Herpes Simplex Virus, rotavirus, Mycoplasma pneumoniae and rhinovirus, the latter two being respiratory pathogens, as well as peptide YGLPHKF having similarity to a protein of unknown function from the respiratory pathogen Legionella pneumophila. Peptides were incorporated into gene delivery formulations with the cationic lipid Lipofectin and plasmid DNA and shown to confer a high degree of transfection efficiency and specificity in 1HAEo-cells. Improved transfection efficiency and specificity was also observed in human endothelial cells, fibroblasts and keratinocytes. Therefore, on the basis of clone frequency after biopanning, cell binding affinity, peptide sequence conservation and pathogenic similarity, we have identified 3 novel peptide families and 5 specific peptides that have the potential for gene transfer to respiratory epithelium in vivo as well as providing useful in vitro transfection reagents for primary human cell types of scientific and commercial interest. PMID:15506167

  9. SGK1 activity in Na+ absorbing airway epithelial cells monitored by assaying NDRG1-Thr346/356/366 phosphorylation.

    PubMed

    Inglis, S K; Gallacher, M; Brown, S G; McTavish, N; Getty, J; Husband, E M; Murray, J T; Wilson, S M

    2009-04-01

    Studies of HeLa cells and serum- and glucocorticoid-regulated kinase 1 (SGK1) knockout mice identified threonine residues in the n-myc downstream-regulated gene 1 protein (NDRG1-Thr(346/356/366)) that are phosphorylated by SGK1 but not by related kinases (Murray et al., Biochem J 385:1-12, 2005). We have, therefore, monitored the phosphorylation of NDRG1-Thr(346/356/366) in order to explore the changes in SGK1 activity associated with the induction and regulation of the glucocorticoid-dependent Na(+) conductance (G (Na)) in human airway epithelial cells. Transient expression of active (SGK1-S422D) and inactive (SGK1-K127A) SGK1 mutants confirmed that activating SGK1 stimulates NDRG1-Thr(346/356/366) phosphorylation. Although G (Na) is negligible in hormone-deprived cells, these cells displayed basal SGK1 activity that was sensitive to LY294002, an inhibitor of 3-phosphatidylinositol phosphate kinase (PI3K). Dexamethasone (0.2 muM) acutely activated SGK1 and the peak of this response (2-3 h) coincided with the induction of G (Na), and both responses were PI3K-dependent. While these data suggest that SGK1 might mediate the rise in G (Na), transient expression of the inactive SGK1-K127A mutant did not affect the hormonal induction of G (Na) but did suppress the activation of SGK1. Dexamethasone-treated cells grown on permeable supports formed confluent epithelial sheets that generated short circuit current due to electrogenic Na(+) absorption. Forskolin and insulin both stimulated this current and the response to insulin, but not forskolin, was LY294002-sensitive and associated with the activation of SGK1. While these data suggest that SGK1 is involved in the control of G (Na), its role may be minor, which could explain why sgk1 knockout has different effects upon different tissues. PMID:18787837

  10. Exposure to sodium butyrate leads to functional downregulation of calcium-activated potassium channels in human airway epithelial cells.

    PubMed

    Roy, Jeremy; Denovan-Wright, Eileen M; Linsdell, Paul; Cowley, Elizabeth A

    2006-11-01

    Cystic fibrosis (CF) is caused by genetic mutations that lead to dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel. The most common mutation, DeltaF508, causes inefficient trafficking of mutant CFTR protein from the endoplasmic reticulum to the cell membrane. Therapeutic efforts have been aimed at increasing the level of DeltaF508-CFTR protein in the membrane using agents such as sodium butyrate. In this study, we investigated the effects of culturing a human airway epithelial cell line, Calu-3, in the presence of 5 mM sodium butyrate. Within 24 h, butyrate exposure caused a significant decrease in the basal, as well as Ca(2+)-activated, anion secretion by Calu-3 cell monolayers, determined by the change in transepithelial short-circuit current in response to the Ca(2+)-elevating agent thapsigargin. The secretory response to 1-ethyl-2-benzimidazolinone, an activator of the basolateral Ca(2+)-activated K(+) channel KCNN4, was similarly reduced by butyrate treatment. Quantitative PCR revealed that these functional effects were associated with dramatic decreases in mRNA for both KCNN4 and CFTR. Furthermore, the KCNQ1 K(+) channel was upregulated after butyrate treatment. We suggest that prolonged exposure to sodium butyrate downregulates the expression of both KCNN4 and CFTR, leading to a functional loss of Ca(2+)-activated anion secretion. Thus, butyrate may inhibit, rather than stimulate, the anion secretory capacity of human epithelial cells that express wild-type CFTR, particularly in tissues that normally exhibit robust Ca(2+)-activated secretion. PMID:17047984

  11. Virulence Factors of Pseudomonas aeruginosa Induce Both the Unfolded Protein and Integrated Stress Responses in Airway Epithelial Cells.

    PubMed

    van 't Wout, Emily F A; van Schadewijk, Annemarie; van Boxtel, Ria; Dalton, Lucy E; Clarke, Hanna J; Tommassen, Jan; Marciniak, Stefan J; Hiemstra, Pieter S

    2015-06-01

    Pseudomonas aeruginosa infection can be disastrous in chronic lung diseases such as cystic fibrosis and chronic obstructive pulmonary disease. Its toxic effects are largely mediated by secreted virulence factors including pyocyanin, elastase and alkaline protease (AprA). Efficient functioning of the endoplasmic reticulum (ER) is crucial for cell survival and appropriate immune responses, while an excess of unfolded proteins within the ER leads to "ER stress" and activation of the "unfolded protein response" (UPR). Bacterial infection and Toll-like receptor activation trigger the UPR most likely due to the increased demand for protein folding of inflammatory mediators. In this study, we show that cell-free conditioned medium of the PAO1 strain of P. aeruginosa, containing secreted virulence factors, induces ER stress in primary bronchial epithelial cells as evidenced by splicing of XBP1 mRNA and induction of CHOP, GRP78 and GADD34 expression. Most aspects of the ER stress response were dependent on TAK1 and p38 MAPK, except for the induction of GADD34 mRNA. Using various mutant strains and purified virulence factors, we identified pyocyanin and AprA as inducers of ER stress. However, the induction of GADD34 was mediated by an ER stress-independent integrated stress response (ISR) which was at least partly dependent on the iron-sensing eIF2α kinase HRI. Our data strongly suggest that this increased GADD34 expression served to protect against Pseudomonas-induced, iron-sensitive cell cytotoxicity. In summary, virulence factors from P. aeruginosa induce ER stress in airway epithelial cells and also trigger the ISR to improve cell survival of the host. PMID:26083346

  12. Airway injury during high-level exercise.

    PubMed

    Kippelen, Pascale; Anderson, Sandra D

    2012-05-01

    Airway epithelial cells act as a physical barrier against environmental toxins and injury, and modulate inflammation and the immune response. As such, maintenance of their integrity is critical. Evidence is accumulating to suggest that exercise can cause injury to the airway epithelium. This seems the case particularly for competitive athletes performing high-level exercise, or when exercise takes place in extreme environmental conditions such as in cold dry air or in polluted air. Dehydration of the small airways and increased forces exerted on to the airway surface during severe hyperpnoea are thought to be key factors in determining the occurrence of injury of the airway epithelium. The injury-repair process of the airway epithelium may contribute to the development of the bronchial hyper-responsiveness that is documented in many elite athletes. PMID:22247295

  13. Factors Influencing Adeno-Associated Virus-Mediated Gene Transfer to Human Cystic Fibrosis Airway Epithelial Cells: Comparison with Adenovirus Vectors

    PubMed Central

    Teramoto, S.; Bartlett, J. S.; McCarty, D.; Xiao, X.; Samulski, R. J.; Boucher, R. C.

    1998-01-01

    Adeno-associated virus (AAV) vectors appear promising for use in gene therapy in cystic fibrosis (CF) patients, yet many features of AAV-mediated gene transfer to airway epithelial cells are not well understood. We compared the transduction efficiencies of AAV vectors and adenovirus (Ad) vectors in immortalized cell lines from CF patients and in nasal epithelial primary cultures from normal humans and CF patients. Similar dose-dependent relationships between the vector multiplicities of infection and the efficiencies of lacZ gene transfer were observed. However, levels of transduction for both Ad and recombinant AAV (rAAV) were significantly lower in the airway epithelial cell than in the control cell lines HeLa and HEK 293. Transduction efficiencies differed among cultured epithelial cell types, with poorly differentiated cells transducing more efficiently than well-differentiated cells. A time-dependent increase in gene expression was observed after infection for both vectors. For Ad, but not for AAV, this increase was dependent on prolonged incubation of cells with the vector. Furthermore, for rAAV (but not for rAd), the delay in maximal transduction could be abrogated by wild-type Ad helper infection. Thus, although helper virus is not required for maximal transduction, it increases the kinetics by which this is achieved. Expression of Ad E4 open reading frame 6 or addition of either hydroxyurea or camptothecin resulted in increased AAV transduction, as previously demonstrated for nonairway cells (albeit to lower final levels), suggesting that second-strand synthesis may not be the sole cause of inefficient transduction. Finally, the efficiency of AAV-mediated ex vivo gene transfer to lung cells was similar to that previously described for Ad vectors in that transduction was limited to regions of epithelial injury and preferentially targeted basal-like cells. These studies address the primary factors influencing rAAV infection of human airway cells and should

  14. Factors influencing adeno-associated virus-mediated gene transfer to human cystic fibrosis airway epithelial cells: comparison with adenovirus vectors.

    PubMed

    Teramoto, S; Bartlett, J S; McCarty, D; Xiao, X; Samulski, R J; Boucher, R C

    1998-11-01

    Adeno-associated virus (AAV) vectors appear promising for use in gene therapy in cystic fibrosis (CF) patients, yet many features of AAV-mediated gene transfer to airway epithelial cells are not well understood. We compared the transduction efficiencies of AAV vectors and adenovirus (Ad) vectors in immortalized cell lines from CF patients and in nasal epithelial primary cultures from normal humans and CF patients. Similar dose-dependent relationships between the vector multiplicities of infection and the efficiencies of lacZ gene transfer were observed. However, levels of transduction for both Ad and recombinant AAV (rAAV) were significantly lower in the airway epithelial cell than in the control cell lines HeLa and HEK 293. Transduction efficiencies differed among cultured epithelial cell types, with poorly differentiated cells transducing more efficiently than well-differentiated cells. A time-dependent increase in gene expression was observed after infection for both vectors. For Ad, but not for AAV, this increase was dependent on prolonged incubation of cells with the vector. Furthermore, for rAAV (but not for rAd), the delay in maximal transduction could be abrogated by wild-type Ad helper infection. Thus, although helper virus is not required for maximal transduction, it increases the kinetics by which this is achieved. Expression of Ad E4 open reading frame 6 or addition of either hydroxyurea or camptothecin resulted in increased AAV transduction, as previously demonstrated for nonairway cells (albeit to lower final levels), suggesting that second-strand synthesis may not be the sole cause of inefficient transduction. Finally, the efficiency of AAV-mediated ex vivo gene transfer to lung cells was similar to that previously described for Ad vectors in that transduction was limited to regions of epithelial injury and preferentially targeted basal-like cells. These studies address the primary factors influencing rAAV infection of human airway cells and should

  15. Computational analysis of microbubble flows in bifurcating airways: role of gravity, inertia, and surface tension.

    PubMed

    Chen, Xiaodong; Zielinski, Rachel; Ghadiali, Samir N

    2014-10-01

    Although mechanical ventilation is a life-saving therapy for patients with severe lung disorders, the microbubble flows generated during ventilation generate hydrodynamic stresses, including pressure and shear stress gradients, which damage the pulmonary epithelium. In this study, we used computational fluid dynamics to investigate how gravity, inertia, and surface tension influence both microbubble flow patterns in bifurcating airways and the magnitude/distribution of hydrodynamic stresses on the airway wall. Direct interface tracking and finite element techniques were used to simulate bubble propagation in a two-dimensional (2D) liquid-filled bifurcating airway. Computational solutions of the full incompressible Navier-Stokes equation were used to investigate how inertia, gravity, and surface tension forces as characterized by the Reynolds (Re), Bond (Bo), and Capillary (Ca) numbers influence pressure and shear stress gradients at the airway wall. Gravity had a significant impact on flow patterns and hydrodynamic stress magnitudes where Bo > 1 led to dramatic changes in bubble shape and increased pressure and shear stress gradients in the upper daughter airway. Interestingly, increased pressure gradients near the bifurcation point (i.e., carina) were only elevated during asymmetric bubble splitting. Although changes in pressure gradient magnitudes were generally more sensitive to Ca, under large Re conditions, both Re and Ca significantly altered the pressure gradient magnitude. We conclude that inertia, gravity, and surface tension can all have a significant impact on microbubble flow patterns and hydrodynamic stresses in bifurcating airways. PMID:25068642

  16. Haemophilus influenzae increases the susceptibility and inflammatory response of airway epithelial cells to viral infections.

    PubMed

    Gulraiz, Fahad; Bellinghausen, Carla; Bruggeman, Cathrien A; Stassen, Frank R

    2015-03-01

    Nontypeable Haemophilus influenzae (NTHI), a common colonizer of lungs of patients with chronic obstructive pulmonary disease (COPD), can enhance expression of the cellular receptor intercellular adhesion molecule 1 (ICAM-1), which in turn can be used by major group human rhinoviruses (HRVs) for attachment. Here, we evaluated the effect of NTHI-induced up-regulation of ICAM-1 on viral replication and inflammatory responses toward different respiratory viruses. Therefore, human bronchial epithelial cells were pretreated with heat-inactivated NTHI (hi-NTHI) and subsequently infected with either HRV16 (major group), HRV1B (minor group), or respiratory syncytial virus (RSV). Pretreatment with hi-NTHI significantly up-regulated ICAM-1 in BEAS-2B cells and primary bronchial epithelial cells. Concomitantly, release of infectious HRV16 particles was increased in cells pretreated with hi-NTHI. Pretreatment with hi-NTHI also caused a significant increase in HRV16 RNA, whereas replication of HRV1B and RSV were increased to a far lesser extent and only at later time points. Interestingly, release of IL-6 and IL-8 after RSV, but not HRV, infection was synergistically increased in hi-NTHI-pretreated BEAS-2B cells. In summary, exposure to hi-NTHI significantly enhanced sensitivity toward HRV16 but not HRV1B or RSV, probably through ICAM-1 up-regulation. Furthermore, hi-NTHI pretreatment may enhance the inflammatory response to RSV infection, suggesting that preexisting bacterial infections might exaggerate inflammation during secondary viral infection. PMID:25411435

  17. Mucosal production of uric acid by airway epithelial cells contributes to particulate matter-induced allergic sensitization.

    PubMed

    Gold, M J; Hiebert, P R; Park, H Y; Stefanowicz, D; Le, A; Starkey, M R; Deane, A; Brown, A C; Liu, G; Horvat, J C; Ibrahim, Z A; Sukkar, M B; Hansbro, P M; Carlsten, C; VanEeden, S; Sin, D D; McNagny, K M; Knight, D A; Hirota, J A

    2016-05-01

    Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM10-induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma. PMID:26509876

  18. TAK1 regulates NF-{Kappa}B and AP-1 activation in airway epithelial cells following RSV infection

    SciTech Connect

    Dey, Nilay; Liu Tianshuang; Garofalo, Roberto P.; Casola, Antonella

    2011-09-30

    Respiratory syncytial virus (RSV) is the most common cause of epidemic respiratory diseases in infants and young children. RSV infection of airway epithelial cells induces the expression of immune/inflammatory genes through the activation of a subset of transcription factors, including Nuclear Factor-{kappa}B (NF-{kappa}B) and AP-1. In this study, we have investigated the signaling pathway leading to activation of these two transcription factors in response to RSV infection. Our results show that IKK{beta} plays a key role in viral-induced NF-{kappa}B activation, while JNK regulates AP-1-dependent gene transcription, as demonstrated by using kinase inactive proteins and chemical inhibitors of the two kinases. Inhibition of TAK1 activation, by overexpression of kinase inactive TAK1 or using cells lacking TAK1 expression, significantly reduced RSV-induced NF-{kappa}B and AP-1 nuclear translocation and DNA-binding activity, as well as NF-{kappa}B-dependent gene expression, identifying TAK1 as an important upstream signaling molecule regulating RSV-induced NF-{kappa}B and AP-1 activation. - Highlights: > IKK{beta} is a major kinase involved in RSV-induced NF-{kappa}B activation. > JNK regulates AP-1-dependent gene transcription in RSV infection. > TAK1 is a critical upstream signaling molecule for both pathways in infected cells.

  19. Carvedilol binding to β2-adrenergic receptors inhibits CFTR-dependent anion secretion in airway epithelial cells.

    PubMed

    Peitzman, Elizabeth R; Zaidman, Nathan A; Maniak, Peter J; O'Grady, Scott M

    2016-01-01

    Carvedilol functions as a nonselective β-adrenergic receptor (AR)/α1-AR antagonist that is used for treatment of hypertension and heart failure. Carvedilol has been shown to function as an inverse agonist, inhibiting G protein activation while stimulating β-arrestin-dependent signaling and inducing receptor desensitization. In the present study, short-circuit current (Isc) measurements using human airway epithelial cells revealed that, unlike β-AR agonists, which increase Isc, carvedilol decreases basal and 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate-stimulated current. The decrease in Isc resulted from inhibition of the cystic fibrosis transmembrane conductance regulator (CFTR). The carvedilol effect was abolished by pretreatment with the β2-AR antagonist ICI-118551, but not the β1-AR antagonist atenolol or the α1-AR antagonist prazosin, indicating that its inhibitory effect on Isc was mediated through interactions with apical β2-ARs. However, the carvedilol effect was blocked by pretreatment with the microtubule-disrupting compound nocodazole. Furthermore, immunocytochemistry experiments and measurements of apical CFTR expression by Western blot analysis of biotinylated membranes revealed a decrease in the level of CFTR protein in monolayers treated with carvedilol but no significant change in monolayers treated with epinephrine. These results demonstrate that carvedilol binding to apical β2-ARs inhibited CFTR current and transepithelial anion secretion by a mechanism involving a decrease in channel expression in the apical membrane. PMID:26566905

  20. Epithelial transplantation for the management of severe ocular surface disease.

    PubMed Central

    Holland, E J

    1996-01-01

    PURPOSE: First, to present a new classification of epithelial transplantation procedures for ocular surface disease; second, to present our experience with a keratolimbal allograft procedure for limbal stem cell deficiency; and third, to make recommendations for the indications and postoperative management of epithelial transplantation procedures. METHODS: A review of all epithelial transplantation procedures was performed. A classification of these procedures based on the source of donor tissue and the tissue transplanted was proposed. In addition, a review of 25 eyes of 21 patients who underwent a keratolimbal allograft was completed. Ocular surface stability, improvement of visual acuity, success of subsequent keratoplasties, and preoperative risk factors were evaluated. Results were compared with those of other epithelial transplantation procedures for ocular surface disease. On the basis of the results of published studies, as well as ours, a recommendation for the indication of the various procedures was made. RESULTS: Epithelial transplantation for ocular surface disease can be classified as one of the following procedures: conjunctival autograft (CAU), conjunctival allograft (CAL), conjunctival limbal autograft (CLAU), cadaveric conjunctival limbal allograft (c-CLAL), living related conjunctival limbal allograft (lr-CLAL), or keratolimbal allograft (KLAL). Evaluation of our keratolimbal allograft patients revealed that 18 of 25 eyes (72%) developed a stable ocular surface. Fifteen eyes (60%) demonstrated a significant improvement in visual acuity. Persistent epithelial defects and symblephara were successfully managed with this procedure. Six of 13 (46%) subsequent keratoplasties were successful. Patients with limbal deficiency due to Stevens-Johnson syndrome had a significantly worse outcome. Patients with preoperative conjunctival keratinization also had a significantly worse outcome. Indications for epithelial transplantation are as follows: For patients

  1. Expression of the chloride channel CLC-K in human airway epithelial cells.

    PubMed

    Mummery, Jennifer L; Killey, Jennifer; Linsdell, Paul

    2005-12-01

    Airway submucosal gland function is severely disrupted in cystic fibrosis (CF), as a result of genetic mutation of the cystic fibrosis transmembrane conductance regulator (CFTR), an apical membrane Cl(-) channel. To identify other Cl(-) channel types that could potentially substitute for lost CFTR function in these cells, we investigated the functional and molecular expression of Cl(-) channels in Calu-3 cells, a human cell line model of the submucosal gland serous cell. Whole cell patch clamp recording from these cells identified outwardly rectified, pH- and calcium-sensitive Cl(-) currents that resemble those previously ascribed to ClC-K type chloride channels. Using reverse transcription polymerase chain reaction, we identified expression of mRNA for ClC-2, ClC-3, ClC-4, ClC-5, ClC-6, ClC-7, ClC-Ka, and ClC-Kb, as well as the common ClC-K channel beta subunit barttin. Western blotting confirmed that Calu-3 cells express both ClC-K and barttin protein. Thus, Calu-3 cells express multiple members of the ClC family of Cl(-) channels that, if also expressed in native submucosal gland serous cells within the CF lung, could perhaps act to partially substitute lost CFTR function. Furthermore, this work represents the first evidence for functional ClC-K chloride channel expression within the lung. PMID:16462912

  2. Nano-TiO2 particles impair adhesion of airway epithelial cells to fibronectin

    PubMed Central

    Zarogiannis, Sotirios G.; Filippidis, Aristotelis S.; Fernandez, Solana; Jurkuvenaite, Asta; Ambalavanan, Namasivayam; Stanishevsky, Andrei; Vohra, Yogesh K.; Matalon, Sadis

    2016-01-01

    Titanium dioxide engineered nanoparticles (nano-TiO2) are widely used in the manufacturing of a number of products. Due to their size (<100 nm), when inhaled they may be deposited in the distal lung regions and damage Clara cells. We investigated the mechanisms by which short-term (one-hour) incubation of human airway Clara-like (H441) cells to nano-TiO2 (6 nm in diameter) alters the ability of H441 cells to adhere to extracellular matrix. Our results show that one h post incubation, there was a three fold increase of extracellular H2O2, increased intracellular oxidative stress as demonstrated by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) oxidation, and a five-fold increase of phosphor-ERK1/2 as measured by Western blotting. These changes were accompanied by a 25% decrease of H441 adherence to fibronectin (p<0.05 compared to vehicle incubated H441 cells). Pretreatment with the ERK1/2 inhibitor U0126 for three h, partially prevented this effect. In conclusion, short-term exposure of H441 cells to nano-TiO2 appears to reduce adherence to fibronectin due to oxidative stress and activation of ERK1/2. PMID:22947217

  3. Normal and Cystic Fibrosis Airway Surface Liquid Homeostasis

    PubMed Central

    Tarran, Robert; Button, Brian; Picher, Maryse; Paradiso, Anthony M.; Ribeiro, Carla M.; Lazarowski, Eduardo R.; Zhang, Liqun; Collins, Peter L.; Pickles, Raymond J.; Fredberg, Jeffrey J.; Boucher, Richard C.

    2010-01-01

    Mammalian airways normally regulate the volume of a thin liquid layer, the periciliary liquid (PCL), to facilitate the mucus clearance component of lung defense. Studies under standard (static) culture conditions revealed that normal airway epithelia possess an adenosine-regulated pathway that blends Na+ absorption and Cl− secretion to optimize PCL volume. In cystic fibrosis (CF), the absence of CF transmembrane conductance regulator results in a failure of adenosine regulation of PCL volume, which is predicted to initiate mucus stasis and infection. However, under conditions that mimic the phasic motion of the lung in vivo, ATP release into PCL was increased, CF ion transport was rebalanced, and PCL volume was restored to levels adequate for lung defense. This ATP signaling system was vulnerable, however, to insults that trigger CF bacterial infections, such as viral (respiratory syncitial virus) infections, which up-regulated extracellular ATPase activity and abolished motion-dependent ATP regulation of CF PCL height. These studies demonstrate (i) how the normal coordination of opposing ion transport pathways to maintain PCL volume is disrupted in CF, (ii) the hitherto unknown role of phasic motion in regulating key aspects of normal and CF innate airways defense, and (iii) that maneuvers directed at increasing motion-induced nucleotide release may be therapeutic in CF patients. PMID:16087672

  4. Tear Film Mucins: Front Line Defenders of the Ocular Surface; Comparison with Airway and Gastrointestinal Tract Mucins

    PubMed Central

    Hodges, Robin R.; Dartt, Darlene A.

    2014-01-01

    The ocular surface including the cornea and conjunctiva and its overlying tear film are the first tissues of the eye to interact with the external environment. The tear film is complex containing multiple layers secreted by different glands and tissues. Each layer contains specific molecules and proteins that not only maintain the health of the cells on the ocular surface by providing nourishment and removal of waste products but also protect these cells from environment. A major protective mechanism that the corneal and conjunctival cells have developed is secretion of the innermost layer of the tear film, the mucous layer. Both the cornea and conjunctiva express membrane spanning mucins, whereas the conjunctiva also produces soluble mucins. The mucins present in the tear film serve to maintain the hydration of the ocular surface and to provide lubrication and anti-adhesive properties between the cells of the ocular surface and conjunctiva during the blink. A third function is to contribute to the epithelial barrier to prevent pathogens from binding to the ocular surface. This review will focus on the different types of mucins produced by the corneal and conjunctival epithelia. Also included in this review will be a presentation of the structure of mucins, regulation of mucin production, role of mucins in ocular surface diseases, and the differences in mucin production by the ocular surface, airways and gastrointestinal tract. PMID:23954166

  5. Brd4 Is Essential for IL-1β-Induced Inflammation in Human Airway Epithelial Cells

    PubMed Central

    Khan, Younis M.; Kirkham, Paul; Barnes, Peter J.; Adcock, Ian M.

    2014-01-01

    Background Chronic inflammation and oxidative stress are key features of chronic obstructive pulmonary disease (COPD). Oxidative stress enhances COPD inflammation under the control of the pro-inflammatory redox-sensitive transcription factor nuclear factor-kappaB (NF-κB). Histone acetylation plays a critical role in chronic inflammation and bromodomain and extra terminal (BET) proteins act as “readers” of acetylated histones. Therefore, we examined the role of BET proteins in particular Brd2 and Brd4 and their inhibitors (JQ1 and PFI-1) in oxidative stress- enhanced inflammation in human bronchial epithelial cells. Methods Human primary epithelial (NHBE) cells and BEAS-2B cell lines were stimulated with IL-1β (inflammatory stimulus) in the presence or absence of H2O2 (oxidative stress) and the effect of pre-treatment with bromodomain inhibitors (JQ1 and PFI-1) was investigated. Pro-inflammatory mediators (CXCL8 and IL-6) were measured by ELISA and transcripts by RT-PCR. H3 and H4 acetylation and recruitment of p65 and Brd4 to the native IL-8 and IL-6 promoters was investigated using chromatin immunoprecipitation (ChIP). The impact of Brd2 and Brd4 siRNA knockdown on inflammatory mediators was also investigated. Result H2O2 enhanced IL1β-induced IL-6 and CXCL8 expression in NHBE and BEAS-2B cells whereas H2O2 alone did not have any affect. H3 acetylation at the IL-6 and IL-8 promoters was associated with recruitment of p65 and Brd4 proteins. Although p65 acetylation was increased this was not directly targeted by Brd4. The BET inhibitors JQ1 and PFI-1 significantly reduced IL-6 and CXCL8 expression whereas no effect was seen with the inactive enantiomer JQ1(-). Brd4, but not Brd2, knockdown markedly reduced IL-6 and CXCL8 release. JQ1 also inhibited p65 and Brd4 recruitment to the IL-6 and IL-8 promoters. Conclusion Oxidative stress enhanced IL1β-induced IL-6 and CXCL8 expression was significantly reduced by Brd4 inhibition. Brd4 plays an important role in

  6. Epidemic Keratoconjunctivitis-Causing Adenoviruses Induce MUC16 Ectodomain Release To Infect Ocular Surface Epithelial Cells.

    PubMed

    Menon, Balaraj B; Zhou, Xiaohong; Spurr-Michaud, Sandra; Rajaiya, Jaya; Chodosh, James; Gipson, Ilene K

    2016-01-01

    Human adenoviruses (HAdV), species D in particular (HAdV-D), are frequently associated with epidemic keratoconjunctivitis (EKC). Although the infection originates at the ocular surface epithelium, the mechanisms by which HAdV-Ds bypass the membrane-associated mucin (MAM)-rich glycocalyx of the ocular surface epithelium to trigger infection and inflammation remain unknown. Here, we report that an EKC-causing adenovirus (HAdV-D37), but not a non-EKC-causing one (HAdV-D19p), induces ectodomain release of MUC16-a MAM with barrier functions at the ocular surface-from cultured human corneal and conjunctival epithelial cells. HAdV-D37, but not HAdV-D19p, is also found to decrease the glycocalyx barrier function of corneal epithelial cells, as determined by rose bengal dye penetrance assays. Furthermore, results from quantitative PCR (qPCR) amplification of viral genomic DNA using primers specific to a conserved region of the E1B gene show that, in comparison to infection by HAdV-D19p, infection by HAdV-D37 is significantly increased in corneal epithelial cells. Collectively, these results point to a MUC16 ectodomain release-dependent mechanism utilized by the EKC-causing HAdV-D37 to initiate infection at the ocular surface. These findings are important in terms of understanding the pathogenesis of adenoviral keratoconjunctivitis. Similar MAM ectodomain release mechanisms may be prevalent across other mucosal epithelia in the body (e.g., the airway epithelium) that are prone to adenoviral infection. IMPORTANCE Human adenoviruses (HAdVs) are double-stranded DNA viruses that cause infections across all mucosal tissues in the body. At the ocular surface, HAdVs cause keratoconjunctivitis (E. Ford, K. E. Nelson, and D. Warren, Epidemiol Rev 9:244-261, 1987, and C. M. Robinson, D. Seto, M. S. Jones, D. W. Dyer, and J. Chodosh, Infect Genet Evol 11:1208-1217, 2011, doi:10.1016/j.meegid.2011.04.031)-a highly contagious infection that accounts for nearly 60% of conjunctivitis cases

  7. Tomatidine Inhibits Replication of Staphylococcus aureus Small-Colony Variants in Cystic Fibrosis Airway Epithelial Cells▿

    PubMed Central

    Mitchell, Gabriel; Gattuso, Mariza; Grondin, Gilles; Marsault, Éric; Bouarab, Kamal; Malouin, François

    2011-01-01

    Small-colony variants (SCVs) often are associated with chronic Staphylococcus aureus infections, such as those encountered by cystic fibrosis (CF) patients. We report here that tomatidine, the aglycon form of the plant secondary metabolite tomatine, has a potent growth inhibitory activity against SCVs (MIC of 0.12 μg/ml), whereas the growth of normal S. aureus strains was not significantly altered by tomatidine (MIC, >16 μg/ml). The specific action of tomatidine was bacteriostatic for SCVs and was clearly associated with their dysfunctional electron transport system, as the presence of the electron transport inhibitor 4-hydroxy-2-heptylquinoline-N-oxide (HQNO) caused normal S. aureus strains to become susceptible to tomatidine. Inversely, the complementation of SCVs' respiratory deficiency conferred resistance to tomatidine. Tomatidine provoked a general reduction of macromolecular biosynthesis but more specifically affected the incorporation of radiolabeled leucine in proteins of HQNO-treated S. aureus at a concentration corresponding to the MIC against SCVs. Furthermore, tomatidine inhibited the intracellular replication of a clinical SCV in polarized CF-like epithelial cells. Our results suggest that tomatidine eventually will find some use in combination therapy with other traditional antibiotics to eliminate persistent forms of S. aureus. PMID:21357296

  8. Epidemic Keratoconjunctivitis-Causing Adenoviruses Induce MUC16 Ectodomain Release To Infect Ocular Surface Epithelial Cells

    PubMed Central

    Zhou, Xiaohong; Spurr-Michaud, Sandra; Rajaiya, Jaya; Chodosh, James; Gipson, Ilene K.

    2016-01-01

    ABSTRACT Human adenoviruses (HAdV), species D in particular (HAdV-D), are frequently associated with epidemic keratoconjunctivitis (EKC). Although the infection originates at the ocular surface epithelium, the mechanisms by which HAdV-Ds bypass the membrane-associated mucin (MAM)-rich glycocalyx of the ocular surface epithelium to trigger infection and inflammation remain unknown. Here, we report that an EKC-causing adenovirus (HAdV-D37), but not a non-EKC-causing one (HAdV-D19p), induces ectodomain release of MUC16—a MAM with barrier functions at the ocular surface—from cultured human corneal and conjunctival epithelial cells. HAdV-D37, but not HAdV-D19p, is also found to decrease the glycocalyx barrier function of corneal epithelial cells, as determined by rose bengal dye penetrance assays. Furthermore, results from quantitative PCR (qPCR) amplification of viral genomic DNA using primers specific to a conserved region of the E1B gene show that, in comparison to infection by HAdV-D19p, infection by HAdV-D37 is significantly increased in corneal epithelial cells. Collectively, these results point to a MUC16 ectodomain release-dependent mechanism utilized by the EKC-causing HAdV-D37 to initiate infection at the ocular surface. These findings are important in terms of understanding the pathogenesis of adenoviral keratoconjunctivitis. Similar MAM ectodomain release mechanisms may be prevalent across other mucosal epithelia in the body (e.g., the airway epithelium) that are prone to adenoviral infection. IMPORTANCE Human adenoviruses (HAdVs) are double-stranded DNA viruses that cause infections across all mucosal tissues in the body. At the ocular surface, HAdVs cause keratoconjunctivitis (E. Ford, K. E. Nelson, and D. Warren, Epidemiol Rev 9:244–261, 1987, and C. M. Robinson, D. Seto, M. S. Jones, D. W. Dyer, and J. Chodosh, Infect Genet Evol 11:1208–1217, 2011, doi:10.1016/j.meegid.2011.04.031)—a highly contagious infection that accounts for nearly 60% of

  9. MicroRNA-570-3p regulates HuR and cytokine expression in airway epithelial cells

    PubMed Central

    Roff, Alanna N; Craig, Timothy J; August, Avery; Stellato, Cristiana; Ishmael, Faoud T

    2014-01-01

    Asthma is a chronic lung disease that affects people of all ages and is characterized by high morbidity. The mechanisms of asthma pathogenesis are unclear, and there is a need for development of diagnostic biomarkers and greater understanding of regulation of inflammatory responses in the lung. Post-transcriptional regulation of cytokines, chemokines, and growth factors by the action of microRNAs and RNA-binding proteins on stability or translation of mature transcripts is emerging as a central means of regulating the inflammatory response. In this study, we demonstrate that miR-570-3p expression is increased with TNFα stimuli in normal human bronchial epithelial cells (2.6 ± 0.6, p = 0.01) and the human airway epithelial cell line A549 (4.6 ± 1.4, p = 0.0068), and evaluate the functional effects of its overexpression on predicted mRNA target genes in transfected A549 cells. MiR-570-3p upregulated numerous cytokines and chemokines (CCL4, CCL5, TNFα, and IL-6) and also enhanced their induction by TNFα. For other cytokines (CCL2 and IL-8), the microRNA exhibited an inhibitory effect to repress their upregulation by TNFα. These effects were mediated by a complex pattern of both direct and indirect regulation of downstream targets by miR-570-3p. We also show that the RNA-binding protein HuR is a direct target of miR-570-3p, which has implications for expression of numerous other inflammatory mediators that HuR is known regulate post-transcriptionally. Finally, expression of endogenous miR-570-3p was examined in both serum and exhaled breath condensate (EBC) from asthmatic and healthy patients, and was found to be significantly lower in EBC of asthmatics and inversely correlated to their lung function. These studies implicate miR-570-3p as a potential regulator of asthmatic inflammation with potential as both a diagnostic and therapeutic target in asthma. PMID:25143867

  10. Role of size and composition of traffic and agricultural aerosols in the molecular responses triggered in airway epithelial cells.

    PubMed

    Val, Stéphanie; Stéphanie, Val; Martinon, Laurent; Laurent, Martinon; Cachier, Hélène; Hélène, Cachier; Yahyaoui, Abderrazak; Abderrazak, Yahyaoui; Marfaing, Hélène; Hélène, Marfaing; Baeza-Squiban, Armelle; Armelle, Baeza-Squiban

    2011-09-01

    The increased levels of fine particles in the atmosphere are suspected of aggravating cardiopulmonary diseases, but the determinants of particle toxicity are poorly understood. This work aims at studying the role of composition and size in the toxicity of size-segregated particulate matter (PM) collected at different sites on human bronchial epithelial cells. PM were sampled at a traffic urban site (Urb S) and a rural site (Rur S) during the pesticide-spreading period. Ultrafine (UF), fine (F), and coarse (C) PM were characterized by their shape and chemical composition. Whatever the site, the finest PM (UF and F) induced the mRNA expression of CYP1A1, a biomarker of polyaromatic hydrocarbons (PAH) exposure, NQO-1 and heme HO-1, two antioxidant responsive element-driven genes; and two effect biomarkers, GM-CSF, a proinflammatory cytokine and amphiregulin (AR), a growth factor. C PM have a low or no effect. Interestingly, AR is more strongly induced by rural PM at the same mass exposure. These discrepancies suggest involvement of PM chemical composition: rural PM bearing the characteristics of aged aerosols with a high content of water-soluble components, and PM at urban kerbside sites containing mainly water-insoluble components. To conclude, we provide evidence that the finest PM fractions, whatever their origin, are more prone to induce exposure and effect biomarkers. The AR differential expression suggests a source-dependent effect requiring further investigation because of the role of this growth factor in airway remodeling, a characteristic feature of chronic lung respiratory diseases exacerbated by particulate pollution. PMID:21879948

  11. Role of H2O2 in the oxidative effects of zinc exposure in human airway epithelial cells☆

    PubMed Central

    Wages, Phillip A.; Silbajoris, Robert; Speen, Adam; Brighton, Luisa; Henriquez, Andres; Tong, Haiyan; Bromberg, Philip A.; Simmons, Steven O.; Samet, James M.

    2014-01-01

    Human exposure to particulate matter (PM) is a global environmental health concern. Zinc (Zn2+) is a ubiquitous respiratory toxicant that has been associated with PM health effects. However, the molecular mechanism of Zn2+ toxicity is not fully understood. H2O2 and Zn2+ have been shown to mediate signaling leading to adverse cellular responses in the lung and we have previously demonstrated Zn2+ to cause cellular H2O2 production. To determine the role of Zn2+-induced H2O2 production in the human airway epithelial cell response to Zn2+ exposure. BEAS-2B cells expressing the redox-sensitive fluorogenic sensors HyPer (H2O2) or roGFP2 (EGSH) in the cytosol or mitochondria were exposed to 50 µM Zn2+ for 5 min in the presence of 1 µM of the zinc ionophore pyrithione. Intracellular H2O2 levels were modulated using catalase expression either targeted to the cytosol or ectopically to the mitochondria. HO-1 mRNA expression was measured as a downstream marker of response to oxidative stress induced by Zn2+ exposure. Both cytosolic catalase overexpression and ectopic catalase expression in mitochondria were effective in ablating Zn2+-induced elevations in H2O2. Compartment-directed catalase expression blunted Zn2+-induced elevations in cytosolic EGSH and the increased expression of HO-1 mRNA levels. Zn2+ leads to multiple oxidative effects that are exerted through H2O2-dependent and independent mechanisms. PMID:25462065

  12. Cistrome-based Cooperation between Airway Epithelial Glucocorticoid Receptor and NF-κB Orchestrates Anti-inflammatory Effects.

    PubMed

    Kadiyala, Vineela; Sasse, Sarah K; Altonsy, Mohammed O; Berman, Reena; Chu, Hong W; Phang, Tzu L; Gerber, Anthony N

    2016-06-10

    Antagonism of pro-inflammatory transcription factors by monomeric glucocorticoid receptor (GR) has long been viewed as central to glucocorticoid (GC) efficacy. However, the mechanisms and targets through which GCs exert therapeutic effects in diseases such as asthma remain incompletely understood. We previously defined a surprising cooperative interaction between GR and NF-κB that enhanced expression of A20 (TNFAIP3), a potent inhibitor of NF-κB. Here we extend this observation to establish that A20 is required for maximal cytokine repression by GCs. To ascertain the global extent of GR and NF-κB cooperation, we determined genome-wide occupancy of GR, the p65 subunit of NF-κB, and RNA polymerase II in airway epithelial cells treated with dexamethasone, TNF, or both using chromatin immunoprecipitation followed by deep sequencing. We found that GR recruits p65 to dimeric GR binding sites across the genome and discovered additional regulatory elements in which GR-p65 cooperation augments gene expression. GR targets regulated by this mechanism include key anti-inflammatory and injury response genes such as SERPINA1, which encodes α1 antitrypsin, and FOXP4, an inhibitor of mucus production. Although dexamethasone treatment reduced RNA polymerase II occupancy of TNF targets such as IL8 and TNFAIP2, we were unable to correlate specific binding sequences for GR or occupancy patterns with repressive effects on transcription. Our results suggest that cooperative anti-inflammatory gene regulation by GR and p65 contributes to GC efficacy, whereas tethering interactions between GR and p65 are not universally required for GC-based gene repression. PMID:27076634

  13. Bicarbonate-dependent chloride transport drives fluid secretion by the human airway epithelial cell line Calu-3

    PubMed Central

    Shan, Jiajie; Liao, Jie; Huang, Junwei; Robert, Renaud; Palmer, Melissa L; Fahrenkrug, Scott C; O'Grady, Scott M; Hanrahan, John W

    2012-01-01

    Anion and fluid secretion are both defective in cystic fibrosis (CF); however, the transport mechanisms are not well understood. In this study, Cl− and HCO3− secretion was measured using genetically matched CF transmembrane conductance regulator (CFTR)-deficient and CFTR-expressing cell lines derived from the human airway epithelial cell line Calu-3. Forskolin stimulated the short-circuit current (Isc) across voltage-clamped monolayers, and also increased the equivalent short-circuit current (Ieq) calculated under open-circuit conditions. Isc was equivalent to the HCO3− net flux measured using the pH-stat technique, whereas Ieq was the sum of the Cl− and HCO3− net fluxes. Ieq and HCO3− fluxes were increased by bafilomycin and ZnCl2, suggesting that some secreted HCO3− is neutralized by parallel electrogenic H+ secretion. Ieq and fluid secretion were dependent on the presence of both Na+ and HCO3−. The carbonic anhydrase inhibitor acetazolamide abolished forskolin stimulation of Ieq and HCO3− secretion, suggesting that HCO3− transport under these conditions requires catalysed synthesis of carbonic acid. Cl− was the predominant anion in secretions under all conditions studied and thus drives most of the fluid transport. Nevertheless, 50–70% of Cl− and fluid transport was bumetanide-insensitive, suggesting basolateral Cl− loading by a sodium–potassium–chloride cotransporter 1 (NKCC1)-independent mechanism. Imposing a transepithelial HCO3− gradient across basolaterally permeabilized Calu-3 cells sustained a forskolin-stimulated current, which was sensitive to CFTR inhibitors and drastically reduced in CFTR-deficient cells. Net HCO3− secretion was increased by bilateral Cl− removal and therefore did not require apical Cl−/HCO3− exchange. The results suggest a model in which most HCO3− is recycled basolaterally by exchange with Cl−, and the resulting HCO3−-dependent Cl− transport provides an osmotic driving force for

  14. Role of H2O2 in the oxidative effects of zinc exposure in human airway epithelial cells.

    PubMed

    Wages, Phillip A; Silbajoris, Robert; Speen, Adam; Brighton, Luisa; Henriquez, Andres; Tong, Haiyan; Bromberg, Philip A; Simmons, Steven O; Samet, James M

    2014-01-01

    Human exposure to particulate matter (PM) is a global environmental health concern. Zinc (Zn(2+)) is a ubiquitous respiratory toxicant that has been associated with PM health effects. However, the molecular mechanism of Zn(2+) toxicity is not fully understood. H2O2 and Zn(2+) have been shown to mediate signaling leading to adverse cellular responses in the lung and we have previously demonstrated Zn(2+) to cause cellular H2O2 production. To determine the role of Zn(2+)-induced H2O2 production in the human airway epithelial cell response to Zn(2+) exposure. BEAS-2B cells expressing the redox-sensitive fluorogenic sensors HyPer (H2O2) or roGFP2 (EGSH) in the cytosol or mitochondria were exposed to 50µM Zn(2+) for 5min in the presence of 1µM of the zinc ionophore pyrithione. Intracellular H2O2 levels were modulated using catalase expression either targeted to the cytosol or ectopically to the mitochondria. HO-1 mRNA expression was measured as a downstream marker of response to oxidative stress induced by Zn(2+) exposure. Both cytosolic catalase overexpression and ectopic catalase expression in mitochondria were effective in ablating Zn(2+)-induced elevations in H2O2. Compartment-directed catalase expression blunted Zn(2+)-induced elevations in cytosolic EGSH and the increased expression of HO-1 mRNA levels. Zn(2+) leads to multiple oxidative effects that are exerted through H2O2-dependent and independent mechanisms. PMID:25462065

  15. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration.

    PubMed

    Clunes, Lucy A; Davies, Catrin M; Coakley, Raymond D; Aleksandrov, Andrei A; Henderson, Ashley G; Zeman, Kirby L; Worthington, Erin N; Gentzsch, Martina; Kreda, Silvia M; Cholon, Deborah; Bennett, William D; Riordan, John R; Boucher, Richard C; Tarran, Robert

    2012-02-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB. PMID:21990373

  16. Role of Aspergillus fumigatus in Triggering Protease-Activated Receptor-2 in Airway Epithelial Cells and Skewing the Cells toward a T-helper 2 Bias.

    PubMed

    Homma, Tetsuya; Kato, Atsushi; Bhushan, Bharat; Norton, James E; Suh, Lydia A; Carter, Roderick G; Gupta, Dave S; Schleimer, Robert P

    2016-01-01

    Aspergillus fumigatus (AF) infection and sensitization are common and promote Th2 disease in individuals with asthma. Innate immune responses of bronchial epithelial cells are now known to play a key role in determination of T cell responses upon encounter with inhaled pathogens. We have recently shown that extracts of AF suppress JAK-STAT signaling in epithelial cells and thus may promote Th2 bias. To elucidate the impact of AF on human bronchial epithelial cells, we tested the hypothesis that AF can modulate the response of airway epithelial cells to favor a Th2 response and explored the molecular mechanism of the effect. Primary normal human bronchial epithelial (NHBE) cells were treated with AF extract or fractionated AF extract before stimulation with poly I:C or infection with human rhinovirus serotype 16 (HRV16). Expression of CXCL10 mRNA (real-time RT-PCR) and protein (ELISA) were measured as markers of IFN-mediated epithelial Th1-biased responses. Western blot was performed to evaluate expression of IFN regulatory factor-3 (IRF-3), NF-κB, and tyrosine-protein phosphatase nonreceptor type 11 (PTPN11), which are other markers of Th1 skewing. Knockdown experiments for protease-activated receptor-2 (PAR-2) and PTPN11 were performed to analyze the role of PAR-2 in the mechanism of suppression by AF. AF and a high-molecular-weight fraction of AF extract (HMW-AF; > 50 kD) profoundly suppressed poly I:C- and HRV16-induced expression of both CXCL10 mRNA and protein from NHBE cells via a mechanism that relied upon PAR-2 activation. Both AF extract and a specific PAR-2 activator (AC-55541) suppressed the poly I:C activation of phospho-IRF-3 without affecting activation of NF-κB. Furthermore, HMW-AF extract enhanced the expression of PTPN11, a phosphatase known to inhibit IFN signaling, and concurrently suppressed poly I:C-induced expression of both CXCL10 mRNA and protein from NHBE cells. These results show that exposure of bronchial epithelial cells to AF extract

  17. Diacetyl and 2,3-pentanedione exposure of human cultured airway epithelial cells: Ion transport effects and metabolism of butter flavoring agents.

    PubMed

    Zaccone, Eric J; Goldsmith, W Travis; Shimko, Michael J; Wells, J R; Schwegler-Berry, Diane; Willard, Patsy A; Case, Shannon L; Thompson, Janet A; Fedan, Jeffrey S

    2015-12-15

    Inhalation of butter flavoring by workers in the microwave popcorn industry may result in “popcorn workers' lung.” In previous in vivo studies rats exposed for 6 h to vapor from the flavoring agents, diacetyl and 2,3-pentanedione, acquired flavoring concentration-dependent damage of the upper airway epithelium and airway hyporeactivity to inhaled methacholine. Because ion transport is essential for lung fluid balance,we hypothesized that alterations in ion transport may be an early manifestation of butter flavoring-induced toxicity.We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 h to diacetyl or 2,3-pentanedione vapors (25 or ≥ 60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport,without affecting Cl- transport or Na+,K+-pump activity. Rt was unaffected. Na+ transport recovered 18 h after exposure. Concentrations (100-360 ppm) of diacetyl and 2,3-pentanedione reported earlier to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 h post-exposure. Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro. PMID:26454031

  18. Diacetyl and 2,3-pentanedione exposure of human cultured airway epithelial cells: Ion transport effects and metabolism of butter flavoring agents

    PubMed Central

    Zaccone, Eric J.; Goldsmith, W. Travis; Shimko, Michael J.; Wells, J.R.; Schwegler-Berry, Diane; Willard, Patsy A.; Case, Shannon L.; Thompson, Janet A.; Fedan, Jeffrey S.

    2016-01-01

    Inhalation of butter flavoring by workers in the microwave popcorn industry may result in “popcorn workers' lung.” In previous in vivo studies rats exposed for 6 h to vapor from the flavoring agents, diacetyl and 2,3-pentanedione, acquired flavoring concentration-dependent damage of the upper airway epithelium and airway hyporeactivity to inhaled methacholine. Because ion transport is essential for lung fluid balance, we hypothesized that alterations in ion transport may be an early manifestation of butter flavoring-induced toxicity. We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 h to diacetyl or 2,3-pentanedione vapors (25 or ≥60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport, without affecting Cl− transport or Na+,K+-pump activity. Rt was unaffected. Na+ transport recovered 18 h after exposure. Concentrations (100–360 ppm) of diacetyl and 2,3-pentanedione reported earlier to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 h post-exposure. Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro. PMID:26454031

  19. Airway Surface Dehydration by Transforming Growth Factor β (TGF-β) in Cystic Fibrosis Is Due to Decreased Function of a Voltage-dependent Potassium Channel and Can Be Rescued by the Drug Pirfenidone.

    PubMed

    Manzanares, Dahis; Krick, Stefanie; Baumlin, Nathalie; Dennis, John S; Tyrrell, Jean; Tarran, Robert; Salathe, Matthias

    2015-10-16

    Transforming growth factor β1 (TGF-β1) is not only elevated in airways of cystic fibrosis (CF) patients, whose airways are characterized by abnormal ion transport and mucociliary clearance, but TGF-β1 is also associated with worse clinical outcomes. Effective mucociliary clearance depends on adequate airway hydration, governed by ion transport. Apically expressed, large-conductance, Ca(2+)- and voltage-dependent K(+) (BK) channels play an important role in this process. In this study, TGF-β1 decreased airway surface liquid volume, ciliary beat frequency, and BK activity in fully differentiated CF bronchial epithelial cells by reducing mRNA expression of the BK γ subunit leucine-rich repeat-containing protein 26 (LRRC26) and its function. Although LRRC26 knockdown itself reduced BK activity, LRRC26 overexpression partially reversed TGF-β1-induced BK dysfunction. TGF-β1-induced airway surface liquid volume hyper-absorption was reversed by the BK opener mallotoxin and the clinically useful TGF-β signaling inhibitor pirfenidone. The latter increased BK activity via rescue of LRRC26. Therefore, we propose that TGF-β1-induced mucociliary dysfunction in CF airways is associated with BK inactivation related to a LRRC26 decrease and is amenable to treatment with clinically useful TGF-β1 inhibitors. PMID:26338706

  20. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration

    PubMed Central

    Clunes, Lucy A.; Davies, Catrin M.; Coakley, Raymond D.; Aleksandrov, Andrei A.; Henderson, Ashley G.; Zeman, Kirby L.; Worthington, Erin N.; Gentzsch, Martina; Kreda, Silvia M.; Cholon, Deborah; Bennett, William D.; Riordan, John R.; Boucher, Richard C.; Tarran, Robert

    2012-01-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. PMID:21990373

  1. Effect of Stratification on Surface Properties of Corneal Epithelial Cells

    PubMed Central

    Yáñez-Soto, Bernardo; Leonard, Brian C.; Raghunathan, Vijay Krishna; Abbott, Nicholas L.; Murphy, Christopher J.

    2015-01-01

    Purpose The purpose of this study was to determine the influence of mucin expression in an immortalized human corneal epithelial cell line (hTCEpi) on the surface properties of cells, such as wettability, contact angle, and surface heterogeneity. Methods hTCEpi cells were cultured to confluence in serum-free medium. The medium was then replaced by stratification medium to induce mucin biosynthesis. The mucin expression profile was analyzed using quantitative PCR and Western blotting. Contact angles were measured using a two-immiscible liquid method, and contact angle hysteresis was evaluated by tilting the apparatus and recording advancing and receding contact angles. The spatial distribution of mucins was evaluated with fluorescently labeled lectin. Results hTCEpi cells expressed the three main ocular mucins (MUC1, MUC4, and MUC16) with a maximum between days 1 and 3 of the stratification process. Upon stratification, cells caused a very significant increase in contact angle hysteresis, suggesting the development of spatially discrete and heterogeneously distributed surface features, defined by topography and/or chemical functionality. Although atomic force microscopy measurements showed no formation of appreciable topographic features on the surface of the cells, we observed a significant increase in surface chemical heterogeneity. Conclusions The surface chemical heterogeneity of the corneal epithelium may influence the dynamic behavior of tear film by “pinning” the contact line between the cellular surface and aqueous tear film. Engineering the surface properties of corneal epithelium could potentially lead to novel treatments in dry eye disease. PMID:26747762

  2. Optimal Graph Search Based Segmentation of Airway Tree Double Surfaces Across Bifurcations

    PubMed Central

    Chen, Danny Z.; Tawhai, Merryn H.; Wu, Xiaodong; Hoffman, Eric A.; Sonka, Milan

    2014-01-01

    Identification of both the luminal and the wall areas of the bronchial tree structure from volumetric X-ray computed tomography (CT) data sets is of critical importance in distinguishing important phenotypes within numerous major lung diseases including chronic obstructive pulmonary diseases (COPD) and asthma. However, accurate assessment of the inner and outer airway wall surfaces of a complete 3-D tree structure is difficult due to their complex nature, particularly around the branch areas. In this paper, we extend a graph search based technique (LOGISMOS) to simultaneously identify multiple inter-related surfaces of branching airway trees. We first perform a presegmentation of the input 3-D image to obtain basic information about the tree topology. The presegmented image is resampled along judiciously determined paths to produce a set of vectors of voxels (called voxel columns). The resampling process utilizes medial axes to ensure that voxel columns of appropriate lengths and directions are used to capture the object surfaces without interference. A geometric graph is constructed whose edges connect voxels in the resampled voxel columns and enforce validity of the smoothness and separation constraints on the sought surfaces. Cost functions with directional information are employed to distinguish inner and outer walls. The assessment of wall thickness measurement on a CT-scanned double-wall physical phantom (patterned after an in vivo imaged human airway tree) achieved highly accurate results on the entire 3-D tree. The observed mean signed error of wall thickness ranged from −0.09 ± 0.24 mm to 0.07 ± 0.23 mm in bifurcating/nonbifurcating areas. The mean unsigned errors were 0.16 ± 0.12 mm to 0.20 ± 0.11 mm. When the airway wall surface was partitioned into meaningful subregions, the airway wall thickness accuracy was the same in most tested bifurcation/nonbifurcation and carina/noncarina regions (p=NS). Once validated on phantoms, our method was applied

  3. Electrolyte transport properties in distal small airways from cystic fibrosis pigs with implications for host defense.

    PubMed

    Li, Xiaopeng; Tang, Xiao Xiao; Vargas Buonfiglio, Luis G; Comellas, Alejandro P; Thornell, Ian M; Ramachandran, Shyam; Karp, Philip H; Taft, Peter J; Sheets, Kelsey; Abou Alaiwa, Mahmoud H; Welsh, Michael J; Meyerholz, David K; Stoltz, David A; Zabner, Joseph

    2016-04-01

    While pathological and clinical data suggest that small airways are involved in early cystic fibrosis (CF) lung disease development, little is known about how the lack of cystic fibrosis transmembrane conductance regulator (CFTR) function contributes to disease pathogenesis in these small airways. Large and small airway epithelia are exposed to different airflow velocities, temperatures, humidity, and CO2 concentrations. The cellular composition of these two regions is different, and small airways lack submucosal glands. To better understand the ion transport properties and impacts of lack of CFTR function on host defense function in small airways, we adapted a novel protocol to isolate small airway epithelial cells from CF and non-CF pigs and established an organotypic culture model. Compared with non-CF large airways, non-CF small airway epithelia cultures had higher Cl(-) and bicarbonate (HCO3 (-)) short-circuit currents and higher airway surface liquid (ASL) pH under 5% CO2 conditions. CF small airway epithelia were characterized by minimal Cl(-) and HCO3 (-) transport and decreased ASL pH, and had impaired bacterial killing compared with non-CF small airways. In addition, CF small airway epithelia had a higher ASL viscosity than non-CF small airways. Thus, the activity of CFTR is higher in the small airways, where it plays a role in alkalinization of ASL, enhancement of antimicrobial activity, and lowering of mucus viscosity. These data provide insight to explain why the small airways are a susceptible site for the bacterial colonization. PMID:26801568

  4. Mechanosensitive ATP Release Maintains Proper Mucus Hydration of Airways

    PubMed Central

    Button, Brian; Okada, Seiko F.; Frederick, Charles Brandon; Thelin, William R.; Boucher, Richard C.

    2013-01-01

    The clearance of mucus from the airways protects the lungs from inhaled noxious and infectious materials. Proper hydration of the mucus layer enables efficient mucus clearance through beating of cilia on airway epithelial cells, and reduced clearance of excessively concentrated mucus occurs in patients with chronic obstructive pulmonary disease and cystic fibrosis. Key steps in the mucus transport process are airway epithelia sensing and responding to changes in mucus hydration. We reported that extracellular adenosine triphosphate (ATP) and adenosine were important luminal auto-crine and paracrine signals that regulated the hydration of the surface of human airway epithelial cultures through their action on apical membrane purinoceptors. Mucus hydration in human airway epithelial cultures was sensed by an interaction between cilia and the overlying mucus layer: Changes in mechanical strain, proportional to mucus hydration, regulated ATP release rates, adjusting fluid secretion to optimize mucus layer hydration. This system provided a feedback mechanism by which airways maintained mucus hydration in an optimum range for cilia propulsion. Understanding how airway epithelia can sense and respond to changes in mucus properties helps us to understand how the mucus clearance system protects the airways in health and how it fails in lung diseases such as cystic fibrosis. PMID:23757023

  5. Mechanosensitive ATP release maintains proper mucus hydration of airways.

    PubMed

    Button, Brian; Okada, Seiko F; Frederick, Charles Brandon; Thelin, William R; Boucher, Richard C

    2013-06-11

    The clearance of mucus from the airways protects the lungs from inhaled noxious and infectious materials. Proper hydration of the mucus layer enables efficient mucus clearance through beating of cilia on airway epithelial cells, and reduced clearance of excessively concentrated mucus occurs in patients with chronic obstructive pulmonary disease and cystic fibrosis. Key steps in the mucus transport process are airway epithelia sensing and responding to changes in mucus hydration. We reported that extracellular adenosine triphosphate (ATP) and adenosine were important luminal autocrine and paracrine signals that regulated the hydration of the surface of human airway epithelial cultures through their action on apical membrane purinoceptors. Mucus hydration in human airway epithelial cultures was sensed by an interaction between cilia and the overlying mucus layer: Changes in mechanical strain, proportional to mucus hydration, regulated ATP release rates, adjusting fluid secretion to optimize mucus layer hydration. This system provided a feedback mechanism by which airways maintained mucus hydration in an optimum range for cilia propulsion. Understanding how airway epithelia can sense and respond to changes in mucus properties helps us to understand how the mucus clearance system protects the airways in health and how it fails in lung diseases such as cystic fibrosis. PMID:23757023

  6. Cell surface expression and biosynthesis of epithelial Na+ channels.

    PubMed Central

    Prince, L S; Welsh, M J

    1998-01-01

    The epithelial Na+ channel (ENaC) complex is composed of three homologous subunits: alpha, beta and gamma. Mutations in ENaC subunits can increase the number of channels on the cell surface, causing a hereditary form of hypertension called Liddle's syndrome, or can decrease channel activity, causing pseudohypoaldosteronism type I, a salt-wasting disease of infancy. To investigate surface expression, we studied ENaC subunits expressed in COS-7 and HEK293 cells. Using surface biotinylation and protease sensitivity, we found that when individual ENaC subunits are expressed alone, they traffic to the cell surface. The subunits are glycosylated with high-mannose oligosaccharides, but seem to have the carbohydrate removed before they reach the cell surface. Moreover, subunits form a complex that cannot be disrupted by several non-ionic detergents. The pattern of glycosylation and detergent solubility/insolubility persists when the N-teminal and C-terminal cytoplasmic regions of ENaC are removed. With co-expression of all three ENaC subunits, the insoluble complex is the predominant species. These results show that ENaC and its family members are unique in their trafficking, biochemical characteristics and post-translational modifications. PMID:9841884

  7. Regulation of Murine Airway Surface Liquid Volume by CFTR and Ca2+-activated Cl− Conductances

    PubMed Central

    Tarran, Robert; Loewen, Matthew E.; Paradiso, Anthony M.; Olsen, John C.; Gray, Micheal A.; Argent, Barry E.; Boucher, Richard C.; Gabriel, Sherif E.

    2002-01-01

    Two Cl− conductances have been described in the apical membrane of both human and murine proximal airway epithelia that are thought to play predominant roles in airway hydration: (1) CFTR, which is cAMP regulated and (2) the Ca2+-activated Cl− conductance (CaCC) whose molecular identity is uncertain. In addition to second messenger regulation, cross talk between these two channels may also exist and, whereas CFTR is absent or defective in cystic fibrosis (CF) airways, CaCC is preserved, and may even be up-regulated. Increased CaCC activity in CF airways is controversial. Hence, we have investigated the effects of CFTR on CaCC activity and have also assessed the relative contributions of these two conductances to airway surface liquid (ASL) height (volume) in murine tracheal epithelia. We find that CaCC is up-regulated in intact murine CF tracheal epithelia, which leads to an increase in UTP-mediated Cl−/volume secretion. This up-regulation is dependent on cell polarity and is lost in nonpolarized epithelia. We find no role for an increased electrical driving force in CaCC up-regulation but do find an increased Ca2+ signal in response to mucosal nucleotides that may contribute to the increased Cl−/volume secretion seen in intact epithelia. CFTR plays a critical role in maintaining ASL height under basal conditions and accordingly, ASL height is reduced in CF epithelia. In contrast, CaCC does not appear to significantly affect basal ASL height, but does appear to be important in regulating ASL height in response to released agonists (e.g., mucosal nucleotides). We conclude that both CaCC and the Ca2+ signal are increased in CF airway epithelia, and that they contribute to acute but not basal regulation of ASL height. PMID:12198094

  8. CRISPR-Cas9 mediated gene knockout in primary human airway epithelial cells reveals a pro-inflammatory role for MUC18

    PubMed Central

    Chu, Hong Wei; Rios, Cydney; Huang, Chunjian; Wesolowska-Andersen, Agata; Burchard, Esteban G.; O'Connor, Brian P.; Fingerlin, Tasha E.; Nichols, David; Reynolds, Susan D.; Seibold, Max A.

    2015-01-01

    Targeted knockout of genes in primary human cells using CRISPR-Cas9 mediated genome-editing represents a powerful approach to study gene function and to discern molecular mechanisms underlying complex human diseases. We used lentiviral delivery of CRISPR-Cas9 machinery and conditional reprogramming culture methods to knockout the MUC18 gene in human primary nasal airway epithelial cells (AECs). Massively parallel sequencing technology was used to confirm that the genome of essentially all cells in the edited AEC populations contained coding region insertions and deletions (indels). Correspondingly, we found mRNA expression of MUC18 was greatly reduced and protein expression was absent. Characterization of MUC18 knockout cell populations stimulated with TLR2, 3 and 4 agonists revealed that IL-8 (a pro-inflammatory chemokine) responses of AECs were greatly reduced in the absence of functional MUC18 protein. Our results show the feasibility of CRISPR-Cas9 mediated gene knockouts in AEC culture (both submerged and polarized), and suggest a pro-inflammatory role for MUC18 in airway epithelial response to bacterial and viral stimuli. PMID:26043872

  9. Down-regulation of IL-8 expression in human airway epithelial cells through helper-dependent adenoviral-mediated RNA interference

    PubMed Central

    CAO, Huibi; WANG, Anan; MARTIN, Bernard; KOEHLER, David R.; ZEITLIN, Pamela L.; TANAWELL, A. Keith; HU, Jim

    2015-01-01

    Interleukin (IL)-8 is a potent neutrophil chemotactic factor and a crucial mediator in neutrophil-dependent inflammation. Various cell types produce IL-8, either in response to external stimuli such as cytokines or bacterial infection, or after malignant transformation. Anti-IL-8 strategies have been considered for anti-inflammatory therapy. In this paper we demonstrate that the RNA interference technique can be used to efficiently down-regulate IL-8 protein expression in airway epithelial cells. We used a helper-dependent adenoviral vector to express a small hairpin (sh)RNA targeting human IL-8 in cultured airway epithelial cells (IB3-1, Cftr−/−; C38, Cftr-corrected) stimulated with TNF-α, IL-1β or heat-inactivated Burkholderia cenocepacia. Stimulated IL-8 expression in IB3-1 and C38 cells was significantly reduced by shRNA expression. The shRNA targeting IL-8 had no effect on the activation of NF-κB, or on the protein levels of IκB or IL-6, suggesting that this anti-IL-8 strategy was highly specific, and therefore may offer potential for the treatment of inflammatory diseases. PMID:15740640

  10. Secretory response induced by essential oils on airway surface fluid: a pharmacological MRI study.

    PubMed

    Nicolato, Elena; Boschi, Federico; Marzola, Pasquina; Sbarbati, Andrea

    2009-07-30

    Using pharmacological magnetic resonance imaging, we have performed an in vivo evaluation of the secretory response induced by essential oils in the rat airway. Aim of the work was to establish a computerized method to assess the efficacy of volatile compounds in spatially localized areas without the bias derived by subjective evaluation. Magnetic resonance experiments were carried out using a 4.7 T horizontal magnet. In the trachea, airway surface fluid was easily identified for its high intensity signal. The tracheal glands were also easily visible. The oesophageal lumen was usually collapsed and was identifiable only in the presence of intraluminal liquid. Scotch pine essential oil inhalation significantly increased the surface fluid in the middle portion of the trachea and the increase was visible at both 5 and 10 min. A lesser secretory response was detected after rosemary essential oil inhalation even though the response was significant with respect to the control in particular at 10 min. No secretory response was detected after peppermint essential oil inhalation both at 5 and 10 min. The data obtained in the present work demonstrate a chemically induced airway secretion. The availability of a pharmacological magnetic resonance imaging approach opens new perspectives to test the action of volatile compounds on the airway. PMID:19422906

  11. The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing.

    PubMed

    Zabner, J; Seiler, M P; Launspach, J L; Karp, P H; Kearney, W R; Look, D C; Smith, J J; Welsh, M J

    2000-10-10

    The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface. PMID:11027360

  12. The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing

    PubMed Central

    Zabner, Joseph; Seiler, Michael P.; Launspach, Janice L.; Karp, Philip H.; Kearney, William R.; Look, Dwight C.; Smith, Jeffrey J.; Welsh, Michael J.

    2000-01-01

    The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface. PMID:11027360

  13. Respiratory epithelial cells orchestrate pulmonary innate immunity.

    PubMed

    Whitsett, Jeffrey A; Alenghat, Theresa

    2015-01-01

    The epithelial surfaces of the lungs are in direct contact with the environment and are subjected to dynamic physical forces as airway tubes and alveoli are stretched and compressed during ventilation. Mucociliary clearance in conducting airways, reduction of surface tension in the alveoli, and maintenance of near sterility have been accommodated by the evolution of a multi-tiered innate host-defense system. The biophysical nature of pulmonary host defenses are integrated with the ability of respiratory epithelial cells to respond to and 'instruct' the professional immune system to protect the lungs from infection and injury. PMID:25521682

  14. Cell surface morphology in epithelial malignancy and its precursor lesions.

    PubMed

    Kenemans, P; Davina, J H; de Haan, R W; van der Zanden, P; Vooys, G P; Stolk, J G; Stadhouders, A M

    1981-01-01

    The cell surface organization of cancer cells is of potentially great significance, as it may not only allow (early) diagnosis, but as it may also harbour markers for refined prognosis (degree of oncogenetic and metastatic potential), and targets for selective cancer (chemo- and immuno) therapy. With these aspects in mind, the present review deals with SEM work done on (pre-) malignant cells, both in vivo and in vitro, and in animal models. Attention, however, is focused on human cancer cells. Cancer cells in vitro may lose many of their original malignant characteristics, and show adaptations to culture conditions. Many other factors have been shown to influence cell surface morphology, such as cell cycle, cell contacts, and preparations technique. Cancer cells differ in their surface morphology from normal cells, and have an extra ordinary amount of surface activity. Human malignant epithelial cells show abundant long. pleomorphic microvilli, especially those present in effusions. In squamous epithelium (bladder, cervix) microridge system present on normal superficial cells are progressively replaced by microvilli which increase in number and degree of pleomorphism during experimental and clinical oncogenesis. The question of whether or not the appearance of long. Pleomorphic microvilli reflects an irreversible alteration of the epithelium, and thus provides an early marker of irreversible neoplastic transformation is considered and assessed on the basis of our work with (pre-) malignant cells of the human uterine cervix. Although SEM has contributed significantly to the description of oncogenesis, up to now it has no early diagnostic, prognostic or therapeutic significance. PMID:7199203

  15. Airway epithelial cells initiate the allergen response through transglutaminase 2 by inducing IL-33 expression and a subsequent Th2 response

    PubMed Central

    2013-01-01

    Background Transglutaminase 2 (TG2) is a post-translational protein-modifying enzyme that catalyzes the transamidation reaction, producing crosslinked or polyaminated proteins. Increased TG2 expression and activity have been reported in various inflammatory conditions, such as rheumatoid arthritis, inflammation-associated pulmonary fibrosis, and autoimmune encephalitis. In particular, TG2 from epithelial cells is important during the initial inflammatory response in the lung. In this study, we evaluated the role of TG2 in the pathogenesis of allergic asthma, particularly whether TG2 affects initial activation signaling leading to Th2 differentiation against antigens. Methods We induced allergic asthma by ovalbumin sensitization and intranasal challenge in wild-type (WT) BALB/c and TG2-deficient mice. Broncheoalveolar lavage fluid cells and intracellular cytokine production were analyzed by flow cytometry. Interleukin (IL)-33 and TG2 expression in lung epithelial cells was detected by confocal microscopy. Results Airway responsiveness was attenuated in TG2-deficient mice compared to that in the WT control. In addition, recruitment of eosinophils and Th2 and Th17 differentiation decreased in TG2-deficient mice. Treatment with cysteamine, a transglutaminase inhibitor, also reduced airway hypersensitivity, inflammatory cell recruitment, and T helper cell differentiation. TG2-deficient mice showed reduced IL-33 expression following induction of allergic asthma compared to those in the WT control. Conclusions We found that pulmonary epithelial cells damaged by allergens triggered TG2-mediated IL-33 expression leading to type 2 responses by recruiting both innate and adaptive arms of the immune system. PMID:23496815

  16. IFN-γ-induced JAK/STAT, but not NF-κB, signaling pathway is insensitive to glucocorticoid in airway epithelial cells.

    PubMed

    O'Connell, Danielle; Bouazza, Belaid; Kokalari, Blerina; Amrani, Yassine; Khatib, Alaa; Ganther, John David; Tliba, Omar

    2015-08-15

    Although the majority of patients with asthma are well controlled by inhaled glucocorticoids (GCs), patients with severe asthma are poorly responsive to GCs. This latter group is responsible for a disproportionate share of health care costs associated with asthma. Recent studies in immune cells have incriminated interferon-γ (IFN-γ) as a possible trigger of GC insensitivity in severe asthma; however, little is known about the role of IFN-γ in modulating GC effects in other clinically relevant nonimmune cells, such as airway epithelial cells. We hypothesized that IFN-γ-induced JAK/STAT-associated signaling pathways in airway epithelial cells are insensitive to GCs and that strategies aimed at inhibiting JAK/STAT pathways can restore steroid responsiveness. Using Western blot analysis we found that all steps of the IFN-γ-induced JAK/STAT signaling pathway were indeed GC insensitive. Transfection of cells with reporter plasmid showed IFN-γ-induced STAT1-dependent gene transcription to be also GC insensitive. Interestingly, real-time PCR analysis showed that IFN-γ-inducible genes (IIGs) were differentially affected by GC, with CXCL10 being GC sensitive and CXCL11 and IFIT2 being GC insensitive. Further investigation showed that the differential sensitivity of IIGs to GC was due to their variable dependency to JAK/STAT vs. NF-κB signaling pathways with GC-sensitive IIGs being more NF-κB dependent and GC-insensitive IIGs being more JAK/STAT dependent. Importantly, transfection of cells with siRNA-STAT1 was able to restore steroid responsiveness of GC-insensitive IIGs. Taken together, our results show the insensitivity of IFN-γ-induced JAK/STAT signaling pathways to GC effects in epithelial cells and also suggest that targeting STAT1 could restore GC responsiveness in patients with severe asthma. PMID:26092996

  17. Basolateral localization of fiber receptors limits adenovirus infection from the apical surface of airway epithelia.

    PubMed

    Walters, R W; Grunst, T; Bergelson, J M; Finberg, R W; Welsh, M J; Zabner, J

    1999-04-01

    Recent identification of two receptors for the adenovirus fiber protein, coxsackie B and adenovirus type 2 and 5 receptor (CAR), and the major histocompatibility complex (MHC) Class I alpha-2 domain allows the molecular basis of adenoviral infection to be investigated. Earlier work has shown that human airway epithelia are resistant to infection by adenovirus. Therefore, we examined the expression and localization of CAR and MHC Class I in an in vitro model of well differentiated, ciliated human airway epithelia. We found that airway epithelia express CAR and MHC Class I. However, neither receptor was present in the apical membrane; instead, both were polarized to the basolateral membrane. These findings explain the relative resistance to adenovirus infection from the apical surface. In contrast, when the virus was applied to the basolateral surface, gene transfer was much more efficient because of an interaction of adenovirus fiber with its receptors. In addition, when the integrity of the tight junctions was transiently disrupted, apically applied adenovirus gained access to the basolateral surface and enhanced gene transfer. These data suggest that the receptors required for efficient infection are not available on the apical surface, and interventions that allow access to the basolateral space where fiber receptors are located increase gene transfer efficiency. PMID:10187807

  18. PAX8 Expression in Ovarian Surface Epithelial Cells

    PubMed Central

    Adler, Emily; Mhawech-Fauceglia, Paulette; Gayther, Simon A; Lawrenson, Kate

    2015-01-01

    High-grade serous ovarian carcinoma (HGSOC) is usually diagnosed at a late stage and is associated with poor prognosis. Understanding early stage disease biology is essential in developing clinical biomarkers to detect HGSOC earlier. While recent studies indicate that HGSOCs arise from fallopian tube secretory epithelial cells (FTSECs), a considerable body of evidence also suggests that HGSOC can also arise from ovarian surface epithelial cells (OSECs). PAX8 is overexpressed in HGSOCs and expressed in FTSECs, but there are conflicting reports about PAX8 expression in OSECs. The purpose of this study was to comprehensively characterize PAX8 expression in a large series of OSECs, and to investigate the role of PAX8 in early HGSOC development. PAX8 protein expression was analyzed in the OSECs of 27 normal ovaries and 7 primary OSEC cultures using immunohistochemistry and immunofluorescent cytochemistry. PAX8 mRNA expression was quantified in 66 primary OSEC cultures. Cellular transformation was evaluated in OSECs expressing a PAX8 construct. PAX8 was expressed by 44-71% of OSECs. Calretinin and E-cadherin were frequently co-expressed with PAX8. Expression of PAX8 in OSECs decreased cellular migration (P=0.028), but had no other effects on cellular transformation. In addition, PAX8 expression was significantly increased (P=0.003) in an in vitro stepwise model of neoplastic transformation. In conclusion, PAX8 is frequently expressed by OSECs and endogenous levels of PAX8 expression are non-transforming. These data indicate that in OSECs PAX8 expression may represent a normal state and that OSECs may represent an origin of HGSOCs. PMID:26079312

  19. SGLT1 activity in lung alveolar cells of diabetic rats modulates airway surface liquid glucose concentration and bacterial proliferation.

    PubMed

    Oliveira, Tales Lyra; Candeia-Medeiros, Návylla; Cavalcante-Araújo, Polliane M; Melo, Igor Santana; Fávaro-Pípi, Elaine; Fátima, Luciana Alves; Rocha, Antônio Augusto; Goulart, Luiz Ricardo; Machado, Ubiratan Fabres; Campos, Ruy R; Sabino-Silva, Robinson

    2016-01-01

    High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase SGLT1 activity) or phlorizin (to decrease SGLT1 activity); 2 hours later, glucose concentration and bacterial proliferation (methicillin-resistant Sthaphylococcus aureus, MRSA and Pseudomonas aeruginosa, P. aeruginosa) were analyzed in bronchoalveolar lavage (BAL); and alveolar SGLT1 was analyzed by immunohistochemistry. BAL glucose concentration and bacterial proliferation increased in diabetic animals: isoproterenol stimulated SGLT1 migration to luminal membrane, and reduced (50%) the BAL glucose concentration; whereas phlorizin increased the BAL glucose concentration (100%). These regulations were accompanied by parallel changes of in vitro MRSA and P. aeruginosa proliferation in BAL (r = 0.9651 and r = 0.9613, respectively, Pearson correlation). The same regulations were observed in in vivo P. aeruginosa proliferation. In summary, the results indicate a relationship among SGLT1 activity, ASL glucose concentration and pulmonary bacterial proliferation. Besides, the study highlights that, in situations of pulmonary infection risk, such as in diabetic subjects, increased SGLT1 activity may prevent bacterial proliferation whereas decreased SGLT1 activity can exacerbate it. PMID:26902517

  20. SGLT1 activity in lung alveolar cells of diabetic rats modulates airway surface liquid glucose concentration and bacterial proliferation

    PubMed Central

    Oliveira, Tales Lyra; Candeia-Medeiros, Návylla; Cavalcante-Araújo, Polliane M.; Melo, Igor Santana; Fávaro-Pípi, Elaine; Fátima, Luciana Alves; Rocha, Antônio Augusto; Goulart, Luiz Ricardo; Machado, Ubiratan Fabres; Campos, Ruy R.; Sabino-Silva, Robinson

    2016-01-01

    High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase SGLT1 activity) or phlorizin (to decrease SGLT1 activity); 2 hours later, glucose concentration and bacterial proliferation (methicillin-resistant Sthaphylococcus aureus, MRSA and Pseudomonas aeruginosa, P. aeruginosa) were analyzed in bronchoalveolar lavage (BAL); and alveolar SGLT1 was analyzed by immunohistochemistry. BAL glucose concentration and bacterial proliferation increased in diabetic animals: isoproterenol stimulated SGLT1 migration to luminal membrane, and reduced (50%) the BAL glucose concentration; whereas phlorizin increased the BAL glucose concentration (100%). These regulations were accompanied by parallel changes of in vitro MRSA and P. aeruginosa proliferation in BAL (r = 0.9651 and r = 0.9613, respectively, Pearson correlation). The same regulations were observed in in vivo P. aeruginosa proliferation. In summary, the results indicate a relationship among SGLT1 activity, ASL glucose concentration and pulmonary bacterial proliferation. Besides, the study highlights that, in situations of pulmonary infection risk, such as in diabetic subjects, increased SGLT1 activity may prevent bacterial proliferation whereas decreased SGLT1 activity can exacerbate it. PMID:26902517

  1. Efficient killing of inhaled bacteria in DeltaF508 mice: role of airway surface liquid composition.

    PubMed

    McCray, P B; Zabner, J; Jia, H P; Welsh, M J; Thorne, P S

    1999-07-01

    Cystic fibrosis mice have been generated by gene targeting but show little lung disease without repeated exposure to bacteria. We asked if murine mucosal defenses and airway surface liquid (ASL) Cl(-) were altered by the DeltaF508 cystic fibrosis transmembrane conductance regulator mutation. Naive DeltaF508 -/- and +/- mice showed no pulmonary inflammation and after inhaled Pseudomonas aeruginosa had similar inflammatory responses and bacterial clearance rates. We therefore investigated components of the innate immune system. Bronchoalveolar lavage fluid from mice killed Escherichia coli, and the microbicidal activity was inhibited by NaCl. Because beta-defensins are salt-sensitive epithelial products, we looked for pulmonary beta-defensin expression. A mouse homolog of human beta-defensin-1 (termed "MBD-1") was identified; the mRNA was expressed in the lung. Using a radiotracer technique, ASL volume and Cl(-) concentration ([Cl(-)]) were measured in cultured tracheal epithelia from normal and DeltaF508 -/- mice. The estimated ASL volume was similar for both groups. There were no differences in ASL [Cl(-)] in DeltaF508 -/- and normal mice (13.8 +/- 2.6 vs. 17.8 +/- 5.6 meq/l). Because ASL [Cl(-)] is low in normal and mutant mice, salt-sensitive antimicrobial factors, including MBD-1, may be normally active. PMID:10409246

  2. Dual Oxidase 2 (Duox2) Regulates Pannexin 1-mediated ATP Release in Primary Human Airway Epithelial Cells via Changes in Intracellular pH and Not H2O2 Production.

    PubMed

    Krick, Stefanie; Wang, Junjie; St-Pierre, Melissa; Gonzalez, Carlos; Dahl, Gerhard; Salathe, Matthias

    2016-03-18

    Human airway epithelial cells express pannexin 1 (Panx1) channels to release ATP, which regulates mucociliary clearance. Airway inflammation causes mucociliary dysfunction. Exposure of primary human airway epithelial cell cultures to IFN-γ for 48 h did not alter Panx1 protein expression but significantly decreased ATP release in response to hypotonic stress. The IFN-γ-induced functional down-regulation of Panx1 was due to the up-regulation of dual oxidase 2 (Duox2). Duox2 suppression by siRNA led to an increase in ATP release in control cells and restoration of ATP release in cells treated with IFN-γ. Both effects were reduced by the pannexin inhibitor probenecid. Duox2 up-regulation stoichiometrically increases H2O2 and proton production. H2O2 inhibited Panx1 function temporarily by formation of disulfide bonds at the thiol group of its terminal cysteine. Long-term exposure to H2O2, however, had no inhibitory effect. To assess the role of cellular acidification upon IFN-γ treatment, fully differentiated airway epithelial cells were exposed to ammonium chloride to alkalinize the cytosol. This led to a 2-fold increase in ATP release in cells treated with IFN-γ that was also inhibited by probenecid. Duox2 knockdown also partially corrected IFN-γ-mediated acidification. The direct correlation between intracellular pH and Panx1 open probability was shown in oocytes. Therefore, airway epithelial cells release less ATP in response to hypotonic stress in an inflammatory environment (IFN-γ exposure). Decreased Panx1 function is a response to cell acidification mediated by IFN-γ-induced up-regulation of Duox2, representing a novel mechanism for mucociliary dysfunction in inflammatory airway diseases. PMID:26823467

  3. INHIBITION OF PROTEIN TYROSINE PHOSPHATASE ACTIVITY MEDIATES EPIDERMAL GROWTH FACTOR RECEPTOR SIGNALING IN HUMAN AIRWAY EPITHELIAL CELLS

    EPA Science Inventory

    Epidemiological studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden PM inhibits protein tyrosine phosphatase (PTP) activity in human primary bronchial epithelial cells (HAEC) and leads t...

  4. The impact of oil spill to lung health--Insights from an RNA-seq study of human airway epithelial cells.

    PubMed

    Liu, Yao-Zhong; Roy-Engel, Astrid M; Baddoo, Melody C; Flemington, Erik K; Wang, Guangdi; Wang, He

    2016-03-01

    The Deepwater Horizon oil spill (BP oil spill) in the Gulf of Mexico was a unique disaster event, where a huge amount of oil spilled from the sea bed and a large volume of dispersants were applied to clean the spill. The operation lasted for almost 3 months and involved >50,000 workers. The potential health hazards to these workers may be significant as previous research suggested an association of persistent respiratory symptoms with exposure to oil and oil dispersants. To reveal the potential effects of oil and oil dispersants on the respiratory system at the molecular level, we evaluated the transcriptomic profile of human airway epithelial cells grown under treatment of crude oil, the dispersants Corexit 9500 and Corexit 9527, and oil-dispersant mixtures. We identified a very strong effect of Corexit 9500 treatment, with 84 genes (response genes) differentially expressed in treatment vs. control samples. We discovered an interactive effect of oil-dispersant mixtures; while no response gene was found for Corexit 9527 treatment alone, cells treated with Corexit 9527+oil mixture showed an increased number of response genes (46 response genes), suggesting a synergic effect of 9527 with oil on airway epithelial cells. Through GO (gene ontology) functional term and pathway-based analysis, we identified upregulation of gene sets involved in angiogenesis and immune responses and downregulation of gene sets involved in cell junctions and steroid synthesis as the prevailing transcriptomic signatures in the cells treated with Corexit 9500, oil, or Corexit 9500+oil mixture. Interestingly, these key molecular signatures coincide with important pathological features observed in common lung diseases, such as asthma, cystic fibrosis and chronic obstructive pulmonary disease. Our study provides mechanistic insights into the detrimental effects of oil and oil dispersants to the respiratory system and suggests significant health impacts of the recent BP oil spill to those people

  5. Induction of regulator of G-protein signaling 2 expression by long-acting β2-adrenoceptor agonists and glucocorticoids in human airway epithelial cells.

    PubMed

    Holden, Neil S; George, Tresa; Rider, Christopher F; Chandrasekhar, Ambika; Shah, Suharsh; Kaur, Manminder; Johnson, Malcolm; Siderovski, David P; Leigh, Richard; Giembycz, Mark A; Newton, Robert

    2014-01-01

    In asthma and chronic obstructive pulmonary disease (COPD) multiple mediators act on Gαq-linked G-protein-coupled receptors (GPCRs) to cause bronchoconstriction. However, acting on the airway epithelium, such mediators may also elicit inflammatory responses. In human bronchial epithelial BEAS-2B cells (bronchial epithelium + adenovirus 12-SV40 hybrid), regulator of G-protein signaling (RGS) 2 mRNA and protein were synergistically induced in response to combinations of long-acting β2-adrenoceptor agonist (LABA) (salmeterol, formoterol) plus glucocorticoid (dexamethasone, fluticasone propionate, budesonide). Equivalent responses occurred in primary human bronchial epithelial cells. Concentrations of glucocorticoid plus LABA required to induce RGS2 expression in BEAS-2B cells were consistent with the levels achieved therapeutically in the lungs. As RGS2 is a GTPase-activating protein that switches off Gαq, intracellular free calcium ([Ca(2+)]i) flux was used as a surrogate of responses induced by histamine, methacholine, and the thromboxane receptor agonist U46619 [(Z)-7-[(1S,4R,5R,6S)-5-[(E,3S)-3-hydroxyoct-1-enyl]-3-oxabicyclo[2.2.1]heptan-6-yl]hept-5-enoic acid]. This was significantly attenuated by salmeterol plus dexamethasone pretreatment, or RGS2 overexpression, and the protective effect of salmeterol plus dexamethasone was abolished by RGS2 RNA silencing. Although methacholine and U46619 induced interleukin-8 (IL-8) release and this was inhibited by RGS2 overexpression, the repression of U46619-induced IL-8 release by salmeterol plus dexamethasone was unaffected by RGS2 knockdown. Given a role for Gαq-mediated pathways in inducing IL-8 release, we propose that RGS2 acts redundantly with other effector processes to repress IL-8 expression. Thus, RGS2 expression is a novel effector mechanism in the airway epithelium that is induced by glucocorticoid/LABA combinations. This could contribute to the efficacy of glucocorticoid/LABA combinations in asthma and

  6. Morselized Amniotic Membrane Tissue for Refractory Corneal Epithelial Defects in Cicatricial Ocular Surface Diseases

    PubMed Central

    Cheng, Anny M. S.; Chua, Lorraine; Casas, Victoria; Tseng, Scheffer C. G.

    2016-01-01

    Purpose To evaluate the clinical efficacy of morselized amniotic membrane and umbilical cord tissue (MAU) in treating refractory corneal epithelial defect in ocular cicatricial diseases. Methods Retrospective review of four patients with ocular cicatricial diseases treated with topical MAU for corneal epithelial defects refractory to conventional treatments including topical lubricants, autologous serum, bandage contact lens, and tarsorraphy. Their symptoms, corneal staining, conjunctival inflammation, and visual acuity were compared before and after treatment. Results After topical application of MAU twice daily, two patients demonstrated rapid corneal epithelialization with prompt visual acuity improvement at the first day. All patients showed corneal epithelialization in 7.3 ± 2.6 days accompanied by a significant relief of symptoms, reduction of ocular surface inflammation, and improvement of visual acuity. Conclusion This pilot study suggests topical MAU can be developed into a novel treatment for treating refractory corneal epithelial defects. Translational Relevance Topical MAU can be an effective novel treatment for refractory corneal epithelial defects. PMID:27226933

  7. TMEM16A Inhibitors Reveal TMEM16A as a Minor Component of Calcium-activated Chloride Channel Conductance in Airway and Intestinal Epithelial Cells*

    PubMed Central

    Namkung, Wan; Phuan, Puay-Wah; Verkman, A. S.

    2011-01-01

    TMEM16A (ANO1) functions as a calcium-activated chloride channel (CaCC). We developed pharmacological tools to investigate the contribution of TMEM16A to CaCC conductance in human airway and intestinal epithelial cells. A screen of ∼110,000 compounds revealed four novel chemical classes of small molecule TMEM16A inhibitors that fully blocked TMEM16A chloride current with an IC50 < 10 μm, without interfering with calcium signaling. Following structure-activity analysis, the most potent inhibitor, an aminophenylthiazole (T16Ainh-A01), had an IC50 of ∼1 μm. Two distinct types of inhibitors were identified. Some compounds, such as tannic acid and the arylaminothiophene CaCCinh-A01, fully inhibited CaCC current in human bronchial and intestinal cells. Other compounds, including T16Ainh-A01 and digallic acid, inhibited total CaCC current in these cells poorly, but blocked mainly an initial, agonist-stimulated transient chloride current. TMEM16A RNAi knockdown also inhibited mainly the transient chloride current. In contrast to the airway and intestinal cells, all TMEM16A inhibitors fully blocked CaCC current in salivary gland cells. We conclude that TMEM16A carries nearly all CaCC current in salivary gland epithelium, but is a minor contributor to total CaCC current in airway and intestinal epithelia. The small molecule inhibitors identified here permit pharmacological dissection of TMEM16A/CaCC function and are potential development candidates for drug therapy of hypertension, pain, diarrhea, and excessive mucus production. PMID:21084298

  8. Primary in vitro culture of porcine tracheal epithelial cells in an air-liquid interface as a model to study airway epithelium and Aspergillus fumigatus interactions.

    PubMed

    Khoufache, Khaled; Cabaret, Odile; Farrugia, Cécile; Rivollet, Danièle; Alliot, Annie; Allaire, Eric; Cordonnier, Catherine; Bretagne, Stéphane; Botterel, Françoise

    2010-12-01

    Since the airway epithelium is the first tissue encountered by airborne fungal spores, specific models are needed to study this interaction. We developed such a model using primary porcine tracheal epithelial cells (PTEC) as a possible alternative to the use of primary human cells. PTEC were obtained from pigs and were cultivated in an air-liquid interface. Fluorescent brightener was employed to quantify the internalization of Aspergillus fumigatus conidia. Potential differences (Vt) and transepithelial resistances (Rt) after challenge with the mycotoxin, verruculogen, were studied. Primers for porcine inflammatory mediator genes IL-8, TNF-alpha, and GM-CSF were designed for a quantitative real-time PCR procedure to study cellular responses to challenges with A. fumigatus conidia. TEM showed the differentiation of ciliated cells and the PTEC ability to internalize conidia. The internalization rate was 21.9 ± 1.4% after 8 h of incubation. Verruculogen (10(-6) M) significantly increased Vt without having an effect on the Rt. Exposure of PTEC to live A. fumigatus conidia for 24 h induced a 10- to 40-fold increase in the mRNA levels of inflammatory mediator genes. PTEC behave similarly to human cells and are therefore a suitable alternative to human cells for studying interaction between airway epithelium and A. fumigatus. PMID:20608777

  9. Luteolin inhibited the gene expression, production and secretion of MUC5AC mucin via regulation of nuclear factor kappa B signaling pathway in human airway epithelial cells.

    PubMed

    Lee, Hyun Jae; Seo, Hyo-Seok; Ryu, Jiho; Yoon, Yong Pill; Park, Su Hyun; Lee, Choong Jae

    2015-04-01

    Luteolin, a flavonoidal compound derived from Lonicera japonica Thunb. and Chrysanthemum indicum L., has been reported to show anti-inflammatory, anti-oxidative and anti-carcinogenic effects. In this study, we investigated whether luteolin significantly affects the secretion, production and gene expression of airway mucin. Confluent NCI-H292 cells were pretreated with luteolin for 30 min and then stimulated with EGF (epidermal growth factor) or PMA (phorbol 12-myristate 13-acetate) for 24 h or the indicated periods. The MUC5AC mucin gene expression was measured by RT-PCR. Production and secretion of MUC5AC mucin protein were measured by ELISA. To elucidate the action mechanism of luteolin, effect of luteolin on PMA-induced NF-κB signaling pathway was investigated by western blot analysis. The results were as follows: (1) Luteolin inhibited the secretion of MUC5AC mucin protein induced by EGF or PMA; (2) Luteolin inhibited the production of MUC5AC mucin protein and the expression of MUC5AC mucin gene induced by EGF or PMA; (3) Luteolin inhibited PMA-induced phosphorylation and degradation of inhibitory kappa Bα (IκBα); (4) Luteolin inhibited PMA-induced phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB) p65. This result suggests that luteolin can regulate the secretion, production and gene expression of mucin by acting on airway epithelial cells via regulation of NF-kB signaling pathway. PMID:25285988

  10. Regulation of airway neurogenic inflammation by neutral endopeptidase.

    PubMed

    Di Maria, G U; Bellofiore, S; Geppetti, P

    1998-12-01

    Airway neurogenic inflammation is caused by tachykinins released from peripheral nerve endings of sensory neurons within the airways, and is characterized by plasma protein extravasation, airway smooth muscle contraction and increased secretion of mucus. Tachykinins are degraded and inactivated by neutral endopeptidase (NEP), a membrane-bound metallopeptidase, which is located mainly at the surface of airway epithelial cells, but is also present in airway smooth muscle cells, submucosal gland cells and fibroblasts. The key role of NEP in limiting and regulating the neurogenic inflammation provoked by different stimuli has been demonstrated in a large series of studies published in recent years. It has also been shown that a variety of factors, which are relevant for airway diseases, including viral infections, allergen exposure, inhalation of cigarette smoke and other respiratory irritants, is able to reduce NEP activity, thus enhancing the effects of tachykinins within the airways. On the basis of these observations, the reduction of neutral endopeptidase activity may be regarded as a factor that switches neurogenic airway responses from their physiological and protective functions to a detrimental role that increases and perpetuates airway inflammation. However, further studies are needed to assess the role of neutral endopeptidase down regulation in the pathogenesis of asthma and other inflammatory airway diseases. PMID:9877509

  11. Effect of surface tension of mucosal lining liquid on upper airway mechanics in anesthetized humans.

    PubMed

    Kirkness, Jason P; Eastwood, Peter R; Szollosi, Irene; Platt, Peter R; Wheatley, John R; Amis, Terence C; Hillman, David R

    2003-07-01

    Upper airway (UA) patency may be influenced by surface tension (gamma) operating within the (UAL). We examined the role of gamma of UAL in the maintenance of UA patency in eight isoflurane-anesthetized supine human subjects breathing via a nasal mask connected to a pneumotachograph attached to a pressure delivery system. We evaluated 1). mask pressure at which the UA closed (Pcrit), 2). UA resistance upstream from the site of UA collapse (RUS), and 3). mask pressure at which the UA reopened (Po). A multiple pressure-transducer catheter was used to identify the site of airway closure (velopharyngeal in all subjects). UAL samples (0.2 microl) were collected, and the gamma of UAL was determined by using the "pull-off force" technique. Studies were performed before and after the intrapharyngeal instillation of 5 ml of exogenous surfactant (Exosurf, Glaxo Smith Kline). The gamma of UAL decreased from 61.9 +/- 4.1 (control) to 50.3 +/- 5.0 mN/m (surfactant; P < 0.02). Changes in Po, RUS, and Po - Pcrit (change = control - surfactant) were positively correlated with changes in gamma (r2 > 0.6; P < 0.02) but not with changes in Pcrit (r2 = 0.4; P > 0.9). In addition, mean peak inspiratory airflow (no flow limitation) significantly increased (P < 0.04) from 0.31 +/- 0.06 (control) to 0.36 +/- 0.06 l/s (surfactant). These findings suggest that gamma of UAL exerts a force on the UA wall that hinders airway opening. Instillation of exogenous surfactant into the UA lowers the gamma of UAL, thus increasing UA patency and augmenting reopening of the collapsed airway. PMID:12626492

  12. Pseudomonas aeruginosa triggers CFTR-mediated airway surface liquid secretion in swine trachea

    PubMed Central

    Luan, Xiaojie; Campanucci, Verónica A.; Nair, Manoj; Yilmaz, Orhan; Belev, George; Machen, Terry E.; Chapman, Dean; Ianowski, Juan P.

    2014-01-01

    Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the gene encoding for the anion channel cystic fibrosis transmembrane conductance regulator (CFTR). Several organs are affected in CF, but most of the morbidity and mortality comes from lung disease. Recent data show that the initial consequence of CFTR mutation is the failure to eradicate bacteria before the development of inflammation and airway remodeling. Bacterial clearance depends on a layer of airway surface liquid (ASL) consisting of both a mucus layer that traps, kills, and inactivates bacteria and a periciliary liquid layer that keeps the mucus at an optimum distance from the underlying epithelia, to maximize ciliary motility and clearance of bacteria. The airways in CF patients and animal models of CF demonstrate abnormal ASL secretion and reduced antimicrobial properties. Thus, it has been proposed that abnormal ASL secretion in response to bacteria may facilitate the development of the infection and inflammation that characterize CF airway disease. Whether the inhalation of bacteria triggers ASL secretion, and the role of CFTR, have never been tested, however. We developed a synchrotron-based imaging technique to visualize the ASL layer and measure the effect of bacteria on ASL secretion. We show that the introduction of Pseudomonas aeruginosa and other bacteria into the lumen of intact isolated swine tracheas triggers CFTR-dependent ASL secretion by the submucosal glands. This response requires expression of the bacterial protein flagellin. In patients with CF, the inhalation of bacteria would fail to trigger ASL secretion, leading to infection and inflammation. PMID:25136096

  13. PI3K-delta mediates double-stranded RNA-induced upregulation of B7-H1 in BEAS-2B airway epithelial cells

    SciTech Connect

    Kan-o, Keiko; Matsumoto, Koichiro; Asai-Tajiri, Yukari; Fukuyama, Satoru; Hamano, Saaka; Seki, Nanae; Nakanishi, Yoichi; Inoue, Hiromasa

    2013-05-31

    Highlights: •Double-stranded RNA upregulates B7-H1 on BEAS-2B airway epithelial cells. •The upregulation of B7-H1 is attenuated by inhibition of PI3Kδ isoform. •PI3Kδ-mediated upregulation of B7-H1 is independent of NF-κB activation. •Inhibition of PI3Kδ may prevent persistent viral infection induced by B7-H1. -- Abstract: Airway viral infection disturbs the health-related quality of life. B7-H1 (also known as PD-L1) is a coinhibitory molecule associated with the escape of viruses from the mucosal immunity, leading to persistent infection. Most respiratory viruses generate double-stranded (ds) RNA during replication. The stimulation of cultured airway epithelial cells with an analog of viral dsRNA, polyinosinic-polycytidylic acid (poly IC) upregulates the expression of B7-H1 via activation of the nuclear factor κB(NF-κB). The mechanism of upregulation was investigated in association with phosphatidylinositol 3-kinases (PI3Ks). Poly IC-induced upregulation of B7-H1 was profoundly suppressed by a pan-PI3K inhibitor and partially by an inhibitor or a small interfering (si)RNA for PI3Kδ in BEAS-2B cells. Similar results were observed in the respiratory syncytial virus-infected cells. The expression of p110δ was detected by Western blot and suppressed by pretreatment with PI3Kδ siRNA. The activation of PI3Kδ is typically induced by oxidative stress. The generation of reactive oxygen species was increased by poly IC. Poly IC-induced upregulation of B7-H1 was attenuated by N-acetyl-L-cysteine, an antioxidant, or by oxypurinol, an inhibitor of xanthine oxidase. Poly IC-induced activation of NF-κB was suppressed by a pan-PI3K inhibitor but not by a PI3Kδ inhibitor. These results suggest that PI3Kδ mediates dsRNA-induced upregulation of B7-H1 without affecting the activation of NF-κB.

  14. Direct particle-to-cell deposition of coarse ambient particulate matter increases the production of inflammatory mediators from cultured human airway epithelial cells

    PubMed Central

    Volckens, John; Dailey, Lisa; Walters, Glenn; Devlin, Robert B.

    2010-01-01

    Exposure of cultured cells to particulate matter air pollution is usually accomplished by collecting particles on a solid matrix, extracting the particles from the matrix, suspending them in liquid, and applying the suspension to cells grown on plastic and submerged in medium. The objective of this work was to develop a more physiologically and environmentally relevant model of air pollutant deposition on cultures of human primary airway epithelial cells. We hypothesize that the toxicology of inhaled particulate matter depends strongly on both the particulate dispersion state and the mode of delivery to cells. Our exposure system employs a combination of unipolar charging and electrostatic force to deposit particles directly from the air onto cells grown at an air-liquid interface in a heated, humidified exposure chamber. Normal human bronchial epithelial cells exposed to concentrated, coarse ambient particulate matter in this system expressed increased levels of inflammatory biomarkers at 1 hour following exposure and relative to controls exposed to particle-free air. More importantly, these effects are seen at particulate loadings that are 1-2 orders of magnitude lower than levels applied using traditional in vitro systems. PMID:19603682

  15. Putting the Squeeze on Airway Epithelia.

    PubMed

    Park, Jin-Ah; Fredberg, Jeffrey J; Drazen, Jeffrey M

    2015-07-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  16. Putting the Squeeze on Airway Epithelia

    PubMed Central

    Park, Jin-Ah; Fredberg, Jeffrey J.

    2015-01-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  17. Targeted delivery of antiprotease to the epithelial surface of human tracheal xenografts.

    PubMed

    Ferkol, Thomas; Cohn, Leah A; Phillips, Thomas E; Smith, Arnold; Davis, Pamela B

    2003-05-15

    The cystic fibrosis (CF) lung is uniquely susceptible to Pseudomonas aeruginosa, and infection with this organism incites an intense, compartmentalized inflammatory response that leads to chronic airway obstruction and bronchiectasis. Neutrophils migrate into the airway, and released neutrophil elastase contributes to the progression of the lung disease characteristic of CF. We have developed a strategy that permits the delivery of antiproteases to the inaccessible CF airways by targeting the respiratory epithelium via the human polymeric immunoglobulin receptor (hpIgR). A fusion protein consisting of a single-chain Fv directed against secretory component, the extracellular portion of the pIgR, linked to human alpha1-antitrypsin is effectively ferried across human tracheal xenografts and delivers the antiprotease to the apical surface to a much greater extent than occurs by passive diffusion of human alpha1-antitrypsin alone. Targeted antiprotease delivery paralleled hpIgR expression in the respiratory epithelium in vivo and was not increased by escalating dose, so airway penetration was receptor-dependent, not dose-dependent. Thus, this approach provides us with the ability to deliver therapeutics, like antiproteases, specifically to the lumenal surface of the respiratory epithelium, within the airway surface fluid, where it will be in highest concentration at this site. PMID:12615618

  18. Regulation of secretory leukocyte proteinase inhibitor (SLPI) and elastase-specific inhibitor (ESI/elafin) in human airway epithelial cells by cytokines and neutrophilic enzymes.

    PubMed

    Sallenave, J M; Shulmann, J; Crossley, J; Jordana, M; Gauldie, J

    1994-12-01

    The regulation of the activity of potentially harmful proteinases secreted by neutrophils during inflammation is important for the prevention of excessive tissue injury. Secretory leukocyte proteinase inhibitor (SLPI), also called antileukoprotease (ALP) or mucus proteinase inhibitor (MPI), is a serine proteinase inhibitor that has been found in a variety of mucous secretions and that is secreted by bronchial epithelial cells. We recently reported the presence of SLPI and of an elastase-specific inhibitor (ESI), also called elafin, in the supernatants of two cell lines, NCI-H322 and A549, which have features of Clara cells and type II alveolar cells, respectively. We showed in addition that epithelial cell lines produce the elastase-specific inhibitor as a 12 to 16 kD precursor of the elafin molecule (6 kD) called pre-elafin. In the present study, we show that NCI-H322 cells produced higher amounts of both inhibitors than A549 cells and that basal production of SLPI in both cell lines is higher than the production of elafin/pre-elafin. In addition, we show that interleukin-1 beta and tumor necrosis factor induce significant SLPI expression and are major inducers of elafin/pre-elafin expression. Moreover, induction is greater in A549 cells than in NCI-H322 cells. The implications of these findings for the peripheral airways are twofold: (1) alveolar epithelial cells may respond to cytokines secreted during the onset of inflammation by increasing their antiprotease shield; (2) elafin/pre-elafin seems to be a true local "acute phase reactant" whereas SLPI, in comparison, may be less responsive to local inflammatory mediators. PMID:7946401

  19. A novel dissociative steroid VBP15 reduces MUC5AC gene expression in airway epithelial cells but lacks the GRE mediated transcriptional properties of dexamethasone.

    PubMed

    Garvin, Lindsay M; Chen, Yajun; Damsker, Jesse M; Rose, Mary C

    2016-06-01

    Overproduction of secretory mucins contributes to morbidity/mortality in inflammatory lung diseases. Inflammatory mediators directly increase expression of mucin genes, but few drugs have been shown to directly repress mucin gene expression. IL-1β upregulates the MUC5AC mucin gene in part via the transcription factors NFκB while the glucocorticoid Dexamethasone (Dex) transcriptionally represses MUC5AC expression by Dex-activated GR binding to two GRE cis-sites in the MUC5AC promoter in lung epithelial cells. VBP compounds (ReveraGen BioPharma) maintain anti-inflammatory activity through inhibition of NFκB but exhibit reduced GRE-mediated transcriptional properties associated with adverse side-effects and thus have potential to minimize harmful side effects of long-term steroid therapy in inflammatory lung diseases. We investigated VBP15 efficacy as an anti-mucin agent in two types of airway epithelial cells and analyzed the transcription factor activity and promoter binding associated with VBP15-induced MUC5AC repression. VBP15 reduced MUC5AC mRNA abundance in a dose- and time-dependent manner similar to Dex in the presence or absence of IL-1β in A549 and differentiated human bronchial epithelial cells. Repression was abrogated in the presence of RU486, demonstrating a requirement for GR in the VBP15-induced repression of MUC5AC. Inhibition of NFκB activity resulted in reduced baseline expression of MUC5AC indicating that constitutive activity maintains MUC5AC production. Chromatin immunoprecipitation analysis demonstrated lack of GR and of p65 (NFκB) binding to composite GRE domains in the MUC5AC promoter following VBP15 exposure of cells, in contrast to Dex. These data demonstrate that VBP15 is a novel anti-mucin agent that mediates the reduction of MUC5AC gene expression differently than the classical glucocorticoid, Dex. PMID:27133900

  20. An improved method for fixation of the respiratory epithelial surface with the mucous and surfactant layers

    SciTech Connect

    Hulbert, W.C.; Forster, B.B.; Laird, W.; Pihl, C.E.; Walker, D.C.

    1982-10-01

    A new technique for the stabilization of the mucous layers in the upper respiratory tree is described. The methodology combines perfusion of the thoracic vasculature through the carotid, thyroid, and bronchial arteries, with aerosolization of fixative onto the airway surface through a tracheostomy. The biphasic nature of the mucous layer in healthy animals is confirmed and is compared with the nature of the mucus in animals exposed to cigarette smoke. The fundamental advantage of the technique is that, because airway surface phenomena are stabilized, more thorough correlates of physiology and morphology can be accomplished. The intrapulmonary airways and parenchyma are also fixed by using this technique, and the results are discussed. A preliminary communication using this technique to document leukocyte transit across the respiratory mucosa has been published.

  1. Apoptotic epithelial cells control the abundance of Treg cells at barrier surfaces.

    PubMed

    Nakahashi-Oda, Chigusa; Udayanga, Kankanam Gamage Sanath; Nakamura, Yoshiyuki; Nakazawa, Yuta; Totsuka, Naoya; Miki, Haruka; Iino, Shuichi; Tahara-Hanaoka, Satoko; Honda, Shin-ichiro; Shibuya, Kazuko; Shibuya, Akira

    2016-04-01

    Epithelial tissues continually undergo apoptosis. Commensal organisms that inhabit the epithelium influence tissue homeostasis, in which regulatory T cells (Treg cells) have a central role. However, the physiological importance of epithelial cell apoptosis and how the number of Treg cells is regulated are both incompletely understood. Here we found that apoptotic epithelial cells negatively regulated the commensal-stimulated proliferation of Treg cells. Gut commensals stimulated CX3CR1(+)CD103(-)CD11b(+) dendritic cells (DCs) to produce interferon-β (IFN-β), which augmented the proliferation of Treg cells in the intestine. Conversely, phosphatidylserine exposed on apoptotic epithelial cells suppressed IFN-β production by the DCs via inhibitory signaling mediated by the cell-surface glycoprotein CD300a and thus suppressed Treg cell proliferation. Our findings reveal a regulatory role for apoptotic epithelial cells in maintaining the number of Treg cell and tissue homeostasis. PMID:26855029

  2. Immune-epithelial crosstalk at the intestinal surface.

    PubMed

    Wittkopf, Nadine; Neurath, Markus F; Becker, Christoph

    2014-03-01

    The intestinal tract is one of the most complex organs of the human body. It has to exercise various functions including food and water absorption, as well as barrier and immune regulation. These functions affect not only the gut itself, but influence the overall health of the organism. Diseases involving the gastrointestinal tract such as inflammatory bowel disease and colorectal cancer therefore severely affect the patient's quality of life and can become life-threatening. Intestinal epithelial cells (IECs) play an important role in intestinal inflammation, infection, and cancer development. IECs not only constitute the first barrier in the gut against the lumen, they also constantly signal information about the gut lumen to immune cells, thereby influencing their behaviour. In contrast, by producing various antimicrobial peptides, IECs shape the microbial community within the gut. IECs also respond to cytokines and other mediators of immune cells in the lamina propria. Interactions between epithelial cells and immune cells in the intestine are responsible for gut homeostasis, and modulations of this crosstalk have been reported in studies of gut diseases. This review discusses the wide field of immune-epithelial interactions and shows the importance of immune-epithelial crosstalk in the intestine to gut homeostasis and the overall health status. PMID:24469679

  3. Models of muco-ciliary transport and tracer dispersion in airway surface liquid

    NASA Astrophysics Data System (ADS)

    Smith, David; Blake, John; Gaffney, Eamonn

    2003-11-01

    The airways of the lungs are protected by a thin layer of mucus ( 5-15 microns) which traps dust and other pathogens. The mucus plaque is secreted by specialised epithelial cells, then transported axially towards the pharynx by the action of a dense mat of beating cilia. The cilia beat in a watery `periciliary liquid' (PCL). According to previous theoretical analysis, axial transport of PCL is relatively small, consistent with an impermeable epithelium. However, tracer dispersion experiments by Matsui et al. (1998) appear to show large axial transport, consistent with a highly permeable epithelium. The resolution of the question of the amount of absorption of PCL is related to the issue of the pathogensis of cystic fibrosis lung disease. We present the results of a new model of mucociliary transport which combines the best features of several very different previous models. We also present a model of tracer dispersion and show how this can be used to interpret the findings of Matsui et al. and relate them to our theoretical results.

  4. Effects of Human Parvovirus B19 and Bocavirus VP1 Unique Region on Tight Junction of Human Airway Epithelial A549 Cells

    PubMed Central

    Chiu, Chun-Ching; Shi, Ya-Fang; Yang, Jiann-Jou; Hsiao, Yuan-Chao; Tzang, Bor-Show; Hsu, Tsai-Ching

    2014-01-01

    As is widely recognized, human parvovirus B19 (B19) and human bocavirus (HBoV) are important human pathogens. Obviously, both VP1 unique region (VP1u) of B19 and HBoV exhibit the secreted phospholipase A2 (sPLA2)-like enzymatic activity and are recognized to participate in the pathogenesis of lower respiratory tract illnesses. However, exactly how, both VP1u from B19 and HBoV affect tight junction has seldom been addressed. Therefore, this study investigates how B19-VP1u and HBoV-VP1u may affect the tight junction of the airway epithelial A549 cells by examining phospholipase A2 activity and transepithelial electrical resistance (TEER) as well as performing immunoblotting analyses. Experimental results indicate that TEER is more significantly decreased in A549 cells by treatment with TNF-α (10 ng), two dosages of B19-VP1u and BoV-VP1u (400 ng and 4000 ng) or bee venom PLA2 (10 ng) than that of the control. Accordingly, more significantly increased claudin-1 and decreased occludin are detected in A549 cells by treatment with TNF-α or both dosages of HBoV-VP1u than that of the control. Additionally, more significantly decreased Na+/K+ ATPase is observed in A549 cells by treatment with TNF-α, high dosage of B19-VP1u or both dosages of BoV-VP1u than that of the control. Above findings suggest that HBoV-VP1u rather than B19 VP1u likely plays more important roles in the disruption of tight junction in the airway tract. Meanwhile, this discrepancy appears not to be associated with the secreted phospholipase A2 (sPLA2)-like enzymatic activity. PMID:25268969

  5. Signal Transducer and Activator of Transcription 1 (STAT1) is Essential for Chromium Silencing of Gene Induction in Human Airway Epithelial Cells

    PubMed Central

    Nemec, Antonia A.; Barchowsky, Aaron

    2009-01-01

    Hexavalent chromium (Cr(VI)) promotes lung injury and pulmonary diseases through poorly defined mechanisms that may involve the silencing of inducible protective genes. The current study investigated the hypothesis that Cr(VI) actively signals through a signal transducer and activator of transcription 1 (STAT1)–dependent pathway to silence nickel (Ni)–induced expression of vascular endothelial cell growth factor A (VEGFA), an important mediator of lung injury and repair. In human bronchial airway epithelial (BEAS-2B) cells, Ni-induced VEGFA transcription by stimulating an extracellular regulated kinase (ERK) signaling cascade that involved Src kinase–activated Sp1 transactivation, as well as increased hypoxia-inducible factor-1α (HIF-1α) stabilization and DNA binding. Ni-stimulated ERK, Src, and HIF-1α activities, as well as Ni-induced VEGFA transcript levels were inhibited in Cr(VI)-exposed cells. We previously demonstrated that Cr(VI) stimulates STAT1 to suppress VEGFA expression. In BEAS-2B cells stably expressing STAT1 short hairpin RNA, Cr(VI) increased VEGFA transcript levels and Sp1 transactivation. Moreover, in the absence of STAT1, Cr(VI), and Ni coexposures positively interacted to further increase VEGFA transcripts. This study demonstrates that metal-stimulated signaling cascades interact to regulate transcription and induction of adaptive or repair responses in airway cells. In addition, the data implicate STAT1 as a rate limiting mediator of Cr(VI)-stimulated gene regulation and suggest that cells lacking STAT1, such as many tumor cell lines, have opposite responses to Cr(VI) relative to normal cells. PMID:19403854

  6. Engineering Airway Epithelium

    PubMed Central

    Soleas, John P.; Paz, Ana; Marcus, Paula; McGuigan, Alison; Waddell, Thomas K.

    2012-01-01

    Airway epithelium is constantly presented with injurious signals, yet under healthy circumstances, the epithelium maintains its innate immune barrier and mucociliary elevator function. This suggests that airway epithelium has regenerative potential (I. R. Telford and C. F. Bridgman, 1990). In practice, however, airway regeneration is problematic because of slow turnover and dedifferentiation of epithelium thereby hindering regeneration and increasing time necessary for full maturation and function. Based on the anatomy and biology of the airway epithelium, a variety of tissue engineering tools available could be utilized to overcome the barriers currently seen in airway epithelial generation. This paper describes the structure, function, and repair mechanisms in native epithelium and highlights specific and manipulatable tissue engineering signals that could be of great use in the creation of artificial airway epithelium. PMID:22523471

  7. Basolateral chloride loading by the anion exchanger type 2: role in fluid secretion by the human airway epithelial cell line Calu-3

    PubMed Central

    Huang, Junwei; Shan, Jiajie; Kim, Dusik; Liao, Jie; Evagelidis, Alexandra; Alper, Seth L; Hanrahan, John W

    2012-01-01

    Anion exchanger type 2 (AE2 or SLC4A2) is an electroneutral Cl−/HCO3− exchanger expressed at the basolateral membrane of many epithelia. It is thought to participate in fluid secretion by airway epithelia. However, the role of AE2 in fluid secretion remains uncertain, due to the lack of specific pharmacological inhibitors, and because it is electrically silent and therefore does not contribute directly to short-circuit current (Isc). We have studied the role of AE2 in Cl− and fluid secretion by the airway epithelial cell line Calu-3. After confirming expression of its mRNA and protein, a knock-down cell line called AE2-KD was generated by lentivirus-mediated RNA interference in which AE2 mRNA and protein levels were reduced ≥90%. Suppressing AE2 increased the expression of the cystic fibrosis transmembrane conductance regulator (CFTR) by ∼70% without affecting the levels of NKCC1 (Na+–K+–2Cl− cotransporter) or NBCe1 (Na+–nHCO3− cotransporter). cAMP agonists stimulated fluid secretion by parental Calu-3 and scrambled shRNA cells >6.5-fold. In AE2-KD cells this response was reduced by ∼70%, and the secreted fluid exhibited elevated pH and [HCO3−] as compared with the control lines. Unstimulated equivalent short-circuit current (Ieq) was elevated in AE2-KD cells, but the incremental response to forskolin was unaffected. The modest bumetanide-induced reductions in both Ieq and fluid secretion were more pronounced in AE2-KD cells. Basolateral Cl−/HCO3− exchange measured by basolateral pH-stat in cells with permeabilized apical membranes was abolished in AE2-KD monolayers, and the intracellular alkalinization resulting from basolateral Cl− removal was reduced by ∼80% in AE2-KD cells. These results identify AE2 as a major pathway for basolateral Cl− loading during cAMP-stimulated secretion of Cl− and fluid by Calu-3 cells, and help explain the large bumetanide-insensitive component of fluid secretion reported previously in airway

  8. Effects of reduced mucus oxygen concentration in airway Pseudomonas infections of cystic fibrosis patients

    PubMed Central

    Worlitzsch, Dieter; Tarran, Robert; Ulrich, Martina; Schwab, Ute; Cekici, Aynur; Meyer, Keith C.; Birrer, Peter; Bellon, Gabriel; Berger, Jürgen; Weiss, Tilo; Botzenhart, Konrad; Yankaskas, James R.; Randell, Scott; Boucher, Richard C.; Döring, Gerd

    2002-01-01

    Current theories of CF pathogenesis predict different predisposing “local environmental” conditions and sites of bacterial infection within CF airways. Here we show that, in CF patients with established lung disease, Psuedomonas aeruginosa was located within hypoxic mucopurulent masses in airway lumens. In vitro studies revealed that CF-specific increases in epithelial O2 consumption, linked to increased airway surface liquid (ASL) volume absorption and mucus stasis, generated steep hypoxic gradients within thickened mucus on CF epithelial surfaces prior to infection. Motile P. aeruginosa deposited on CF airway surfaces penetrated into hypoxic mucus zones and responded to this environment with increased alginate production. With P. aeruginosa growth in oxygen restricted environments, local hypoxia was exacerbated and frank anaerobiosis, as detected in vivo, resulted. These studies indicate that novel therapies for CF include removal of hypoxic mucus plaques and antibiotics effective against P. aeruginosa adapted to anaerobic environments. PMID:11827991

  9. Let-7a modulates particulate matter (≤ 2.5 μm)-induced oxidative stress and injury in human airway epithelial cells by targeting arginase 2.

    PubMed

    Song, Lei; Li, Dan; Gu, Yue; Li, Xiaoping; Peng, Liping

    2016-10-01

    Epidemiological studies show that particulate matter (PM) with an aerodynamic diameter ≤ 2.5 μm (PM2.5) is associated with cardiorespiratory diseases via the induction of excessive oxidative stress. However, the precise mechanism underlying PM2.5-mediated oxidative stress injury has not been fully elucidated. Accumulating evidence has indicated the microRNA let-7 family might play a role in PM-mediated pathological processes. In this study, we investigated the role of let-7a in oxidative stress and cell injury in human bronchial epithelial BEAS2B (B2B) cells after PM2.5 exposure. The let-7a level was the most significantly decreased in B2B cells after PM2.5 exposure. The overexpression of let-7a suppressed intracellular reactive oxygen species levels and the percentage of apoptotic cells after PM2.5 exposure, while the let-7a level decreased arginase 2 (ARG2) mRNA and protein levels in B2B cells by directly targeting the ARG2 3'-untranslated region. ARG2 expression was upregulated in B2B cells during PM2.5 treatment, and ARG2 knockdown could remarkably reduce oxidative stress and cellular injury. Moreover, its restoration could abrogate the protective effects of let-7a against PM2.5-induced injury. In conclusion, let-7a decreases and ARG2 increases resulting from PM2.5 exposure may exacerbate oxidative stress, cell injury and apoptosis of B2B cells. The let-7a/ARG2 axis is a likely therapeutic target for PM2.5-induced airway epithelial injury. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26989813

  10. Acidic pH increases airway surface liquid viscosity in cystic fibrosis.

    PubMed

    Tang, Xiao Xiao; Ostedgaard, Lynda S; Hoegger, Mark J; Moninger, Thomas O; Karp, Philip H; McMenimen, James D; Choudhury, Biswa; Varki, Ajit; Stoltz, David A; Welsh, Michael J

    2016-03-01

    Cystic fibrosis (CF) disrupts respiratory host defenses, allowing bacterial infection, inflammation, and mucus accumulation to progressively destroy the lungs. Our previous studies revealed that mucus with abnormal behavior impaired mucociliary transport in newborn CF piglets prior to the onset of secondary manifestations. To further investigate mucus abnormalities, here we studied airway surface liquid (ASL) collected from newborn piglets and ASL on cultured airway epithelia. Fluorescence recovery after photobleaching revealed that the viscosity of CF ASL was increased relative to that of non-CF ASL. CF ASL had a reduced pH, which was necessary and sufficient for genotype-dependent viscosity differences. The increased viscosity of CF ASL was not explained by pH-independent changes in HCO3- concentration, altered glycosylation, additional pH-induced disulfide bond formation, increased percentage of nonvolatile material, or increased sulfation. Treating acidic ASL with hypertonic saline or heparin largely reversed the increased viscosity, suggesting that acidic pH influences mucin electrostatic interactions. These findings link loss of cystic fibrosis transmembrane conductance regulator-dependent alkalinization to abnormal CF ASL. In addition, we found that increasing Ca2+ concentrations elevated ASL viscosity, in part, independently of pH. The results suggest that increasing pH, reducing Ca2+ concentration, and/or altering electrostatic interactions in ASL might benefit early CF. PMID:26808501

  11. Acidic pH increases airway surface liquid viscosity in cystic fibrosis

    PubMed Central

    Tang, Xiao Xiao; Ostedgaard, Lynda S.; Hoegger, Mark J.; Moninger, Thomas O.; Karp, Philip H.; McMenimen, James D.; Choudhury, Biswa; Varki, Ajit; Stoltz, David A.; Welsh, Michael J.

    2016-01-01

    Cystic fibrosis (CF) disrupts respiratory host defenses, allowing bacterial infection, inflammation, and mucus accumulation to progressively destroy the lungs. Our previous studies revealed that mucus with abnormal behavior impaired mucociliary transport in newborn CF piglets prior to the onset of secondary manifestations. To further investigate mucus abnormalities, here we studied airway surface liquid (ASL) collected from newborn piglets and ASL on cultured airway epithelia. Fluorescence recovery after photobleaching revealed that the viscosity of CF ASL was increased relative to that of non-CF ASL. CF ASL had a reduced pH, which was necessary and sufficient for genotype-dependent viscosity differences. The increased viscosity of CF ASL was not explained by pH-independent changes in HCO3– concentration, altered glycosylation, additional pH-induced disulfide bond formation, increased percentage of nonvolatile material, or increased sulfation. Treating acidic ASL with hypertonic saline or heparin largely reversed the increased viscosity, suggesting that acidic pH influences mucin electrostatic interactions. These findings link loss of cystic fibrosis transmembrane conductance regulator–dependent alkalinization to abnormal CF ASL. In addition, we found that increasing Ca2+ concentrations elevated ASL viscosity, in part, independently of pH. The results suggest that increasing pH, reducing Ca2+ concentration, and/or altering electrostatic interactions in ASL might benefit early CF. PMID:26808501

  12. Normalization of raised sodium absorption and raised calcium-mediated chloride secretion by adenovirus-mediated expression of cystic fibrosis transmembrane conductance regulator in primary human cystic fibrosis airway epithelial cells.

    PubMed Central

    Johnson, L G; Boyles, S E; Wilson, J; Boucher, R C

    1995-01-01

    Cystic fibrosis airway epithelia exhibit a spectrum of ion transport properties that differ from normal, including not only defective cAMP-mediated Cl- secretion, but also increased Na+ absorption and increased Ca(2+)-mediated Cl- secretion. In the present study, we examined whether adenovirus-mediated (Ad5) transduction of CFTR can correct all of these CF ion transport abnormalities. Polarized primary cultures of human CF and normal nasal epithelial cells were infected with Ad5-CBCFTR at an moi (10(4)) which transduced virtually all cells or Ad5-CMV lacZ as a control. Consistent with previous reports, Ad5-CBCFTR, but not Ad5-CMV lacZ, corrected defective CF cAMP-mediated Cl- secretion. Basal Na+ transport rates (basal Ieq) in CF airway epithelial sheets (-78.5 +/- 9.8 microA/cm2) were reduced to levels measured in normal epithelial sheets (-30.0 +/- 2.0 microA/cm2) by Ad5-CBCFTR (-36.9 +/- 4.8 microA/cm2), but not Ad5-CMV lacZ (-65.8 +/- 6.1 microA/cm2). Surprisingly, a significant reduction in delta Ieq in response to ionomycin, a measure of Ca(2+)-mediated Cl- secretion, was observed in CFTR-expressing (corrected) CF epithelial sheets (-6.9 +/- 11.8 microA/cm2) when compared to uninfected CF epithelial sheets (-76.2 +/- 15.1 microA/cm2). Dose response effects of Ad5-CBCFTR on basal Na+ transport rates and Ca(2+)-mediated Cl- secretion suggest that the mechanism of regulation of these two ion transport functions by CFTR may be different. In conclusion, efficient transduction of CFTR corrects hyperabsorption of Na+ in primary CF airway epithelial cells and restores Ca(2+)-mediated Cl- secretion to levels observed in normal airway epithelial cells. Moreover, assessment of these ion transport abnormalities may represent important endpoints for testing the efficacy of gene therapy for cystic fibrosis. Images PMID:7533790

  13. Effect of surface potential on epithelial cell adhesion, proliferation and morphology.

    PubMed

    Chang, Hsun-Yun; Kao, Wei-Lun; You, Yun-Wen; Chu, Yi-Hsuan; Chu, Kuo-Jui; Chen, Peng-Jen; Wu, Chen-Yi; Lee, Yu-Hsuan; Shyue, Jing-Jong

    2016-05-01

    Cell adhesion is the basis of individual cell survival, division and motility. Hence, understanding the effects that the surface properties have on cell adhesion, proliferation and morphology are crucial. In particular, surface charge/potential has been identified as an important factor that affects cell behavior. However, how cells respond to incremental changes in surface potential remains unclear. By using binary self-assembled monolayer (SAM) modified Au surfaces that are similar in mechanical/chemical properties and provide a series of surface potentials, the effect of surface potential on the behavior of cells can be studied. In this work, the effect of surface potential on epithelial cells, including human embryonic kidney (HEK293T) and human hepatocellular carcinoma (HepG2), were examined. The results showed that the adhesion density of epithelial cells increased with increasing surface potential, which is similar to but varied more significantly compared with fibroblasts. The proliferation rate is found to be independent of surface potential in both cell types. Furthermore, epithelial cells show no morphological change with respect to surface potential, whereas the morphology of the fibroblasts clearly changed with the surface potential. These differences between the cell types were rationalized by considering the difference in extracellular matrix composition. Laminin-dominant epithelial cells showed higher adhesion density and less morphological change than did fibronectin-dominant fibroblasts because the more significant adsorption of positively charged laminin on the surface enhanced the adhesion of epithelial cells. In contrast, due to the dominance of negatively charged fibronectin that adsorbed weakly on the surface, fibroblasts had to change their morphology to fit the inhomogeneous fibronectin-adsorbed area. PMID:26852101

  14. Upper surfaces of epithelial sheets and of fluid lipid films are nonadhesive for platelets.

    PubMed Central

    Margolis, L B; Vasilieva, E J; Vasiliev, J M; Gelfand, I M

    1979-01-01

    Platelet-rich rabbit plasma was incubated with surfaces of two different types--sheets of cultured mouse kidney epithelium and films of different lipids. The upper surface of epithelial sheets was found to be nonadhesive for platelets; in the same cultures, the platelets attached easily to the glass surface not covered by epithelial cells. Platelets did not attach to the surface of lipids (egg lecthin and dioleoyllecithin) that were in the liquid-crystalline state at 23 degrees C. In contrast, the surface of the films made of lipids (dipalmitoyl- and distearoyllecithin) that were in the crystalline state at 23 degrees C was adhesive for platelets. It had been found previously that the surfaces of epithelial sheets and of liquid lipid films are nonadhesive for fibroblasts. Possible mechanisms responsible for the nonadhesiveness of these surfaces are discussed. It is stressed that the factors responsible for nonadhesiveness of epithelial surfaces may be similar to those responsible for nonadhesiveness of the luminal surface of endothelium in blood vessels. Images PMID:287072

  15. Store-Operated Ca2+ Release-Activated Ca2+ Channels Regulate PAR2-Activated Ca2+ Signaling and Cytokine Production in Airway Epithelial Cells.

    PubMed

    Jairaman, Amit; Yamashita, Megumi; Schleimer, Robert P; Prakriya, Murali

    2015-09-01

    The G-protein-coupled protease-activated receptor 2 (PAR2) plays an important role in the pathogenesis of various inflammatory and auto-immune disorders. In airway epithelial cells (AECs), stimulation of PAR2 by allergens and proteases triggers the release of a host of inflammatory mediators to regulate bronchomotor tone and immune cell recruitment. Activation of PAR2 turns on several cell signaling pathways of which the mobilization of cytosolic Ca(2+) is likely a critical but poorly understood event. In this study, we show that Ca(2+) release-activated Ca(2+) (CRAC) channels encoded by stromal interaction molecule 1 and Orai1 are a major route of Ca(2+) entry in primary human AECs and drive the Ca(2+) elevations seen in response to PAR2 activation. Activation of CRAC channels induces the production of several key inflammatory mediators from AECs including thymic stromal lymphopoietin, IL-6, and PGE2, in part through stimulation of gene expression via nuclear factor of activated T cells (NFAT). Furthermore, PAR2 stimulation induces the production of many key inflammatory mediators including PGE2, IL-6, IL-8, and GM-CSF in a CRAC channel-dependent manner. These findings indicate that CRAC channels are the primary mechanism for Ca(2+) influx in AECs and a vital checkpoint for the induction of PAR2-induced proinflammatory cytokines. PMID:26238490

  16. Serum- and Glucocorticoid-induced Protein Kinase 1 (SGK1) Increases the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) in Airway Epithelial Cells by Phosphorylating Shank2E Protein*

    PubMed Central

    Koeppen, Katja; Coutermarsh, Bonita A.; Madden, Dean R.; Stanton, Bruce A.

    2014-01-01

    The glucocorticoid dexamethasone increases cystic fibrosis transmembrane conductance regulator (CFTR) abundance in human airway epithelial cells by a mechanism that requires serum- and glucocorticoid-induced protein kinase 1 (SGK1) activity. The goal of this study was to determine whether SGK1 increases CFTR abundance by phosphorylating Shank2E, a PDZ domain protein that contains two SGK1 phosphorylation consensus sites. We found that SGK1 phosphorylates Shank2E as well as a peptide containing the first SGK1 consensus motif of Shank2E. The dexamethasone-induced increase in CFTR abundance was diminished by overexpression of a dominant-negative Shank2E in which the SGK1 phosphorylation sites had been mutated. siRNA-mediated reduction of Shank2E also reduced the dexamethasone-induced increase in CFTR abundance. Taken together, these data demonstrate that the glucocorticoid-induced increase in CFTR abundance requires phosphorylation of Shank2E at an SGK1 consensus site. PMID:24811177

  17. Influenza A virus nucleoprotein induces apoptosis in human airway epithelial cells: implications of a novel interaction between nucleoprotein and host protein Clusterin

    PubMed Central

    Tripathi, S; Batra, J; Cao, W; Sharma, K; Patel, J R; Ranjan, P; Kumar, A; Katz, J M; Cox, N J; Lal, R B; Sambhara, S; Lal, S K

    2013-01-01

    Apoptosis induction is an antiviral host response, however, influenza A virus (IAV) infection promotes host cell death. The nucleoprotein (NP) of IAV is known to contribute to viral pathogenesis, but its role in virus-induced host cell death was hitherto unknown. We observed that NP contributes to IAV infection induced cell death and heterologous expression of NP alone can induce apoptosis in human airway epithelial cells. The apoptotic effect of IAV NP was significant when compared with other known proapoptotic proteins of IAV. The cell death induced by IAV NP was executed through the intrinsic apoptosis pathway. We screened host cellular factors for those that may be targeted by NP for inducing apoptosis and identified human antiapoptotic protein Clusterin (CLU) as a novel interacting partner. The interaction between IAV NP and CLU was highly conserved and mediated through β-chain of the CLU protein. Also CLU was found to interact specifically with IAV NP and not with any other known apoptosis modulatory protein of IAV. CLU prevents induction of the intrinsic apoptosis pathway by binding to Bax and inhibiting its movement into the mitochondria. We found that the expression of IAV NP reduced the association between CLU and Bax in mammalian cells. Further, we observed that CLU overexpression attenuated NP-induced cell death and had a negative effect on IAV replication. Collectively, these findings indicate a new function for IAV NP in inducing host cell death and suggest a role for the host antiapoptotic protein CLU in this process. PMID:23538443

  18. Small airway epithelial cells exposure to printer-emitted engineered nanoparticles induces cellular effects on human microvascular endothelial cells in an alveolar-capillary co-culture model.

    PubMed

    Sisler, Jennifer D; Pirela, Sandra V; Friend, Sherri; Farcas, Mariana; Schwegler-Berry, Diane; Shvedova, Anna; Castranova, Vincent; Demokritou, Philip; Qian, Yong

    2015-01-01

    The printer is one of the most common office equipment. Recently, it was reported that toner formulations for printing equipment constitute nano-enabled products (NEPs) and contain engineered nanomaterials (ENMs) that become airborne during printing. To date, insufficient research has been performed to understand the potential toxicological properties of printer-emitted particles (PEPs) with several studies using bulk toner particles as test particles. These studies demonstrated the ability of toner particles to cause chronic inflammation and fibrosis in animal models. However, the toxicological implications of inhalation exposures to ENMs emitted from laser printing equipment remain largely unknown. The present study investigates the toxicological effects of PEPs using an in vitro alveolar-capillary co-culture model with Human Small Airway Epithelial Cells (SAEC) and Human Microvascular Endothelial Cells (HMVEC). Our data demonstrate that direct exposure of SAEC to low concentrations of PEPs (0.5 and 1.0 µg/mL) caused morphological changes of actin remodeling and gap formations within the endothelial monolayer. Furthermore, increased production of reactive oxygen species (ROS) and angiogenesis were observed in the HMVEC. Analysis of cytokine and chemokine levels demonstrates that interleukin (IL)-6 and MCP-1 may play a major role in the cellular communication observed between SAEC and HMVEC and the resultant responses in HMVEC. These data indicate that PEPs at low, non-cytotoxic exposure levels are bioactive and affect cellular responses in an alveolar-capillary co-culture model, which raises concerns for potential adverse health effects. PMID:25387250

  19. THE EFFECTS OF COMBINATORIAL EXPOSURE OF PRO-INFLAMMATORY AND ANTI-INFLAMMATORY CYTOKINES ON AIRWAY EPITHELIAL CELL RELEASE OF CHEMOTACTIC MEDIATORS

    EPA Science Inventory

    Asthma is a chronic inflammatory disorder of the airways affecting nearly 15 million individuals nationally. Within the inflamed asthmatic airway there exist complex interactions between many cells and the cytokines they release, in particular mast cells, eosinophils, T-lymphocy...

  20. Cold-inducible RNA binding protein regulates mucin expression induced by cold temperatures in human airway epithelial cells.

    PubMed

    Ran, DanHua; Chen, LingXiu; Xie, WenYue; Xu, Qing; Han, Zhong; Huang, HuaPing; Zhou, XiangDong

    2016-08-01

    Mucus overproduction is an important manifestation of chronic airway inflammatory diseases, however, the mechanisms underlying the association between cold air and mucus overproduction remain unknown. We found that the expression of the cold-inducible RNA binding protein (CIRP) was increased in patients with chronic obstructive pulmonary disease (COPD). In the present study, we tested whether CIRP was involved in inflammatory factors and mucin5AC (MUC5AC) expression after cold stimulation and investigated the potential signaling pathways involved in this process. We found that CIRP was highly expressed in the bronchi of COPD patients. The expression of CIRP, interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) were increased, and the CIRP was localized in cytoplasm after cold stimulation. MUC5AC mRNA and protein expression levels were elevated in a temperature- and time-dependent manner after cold stimulation and were associated with the phosphorylation of ERK and NF-κB, which reflected their activation. These responses were suppressed by knockdown of CIRP with a specific siRNA or the ERK and NF-κB inhibitors. These results demonstrated that CIRP was expressed in the bronchi of human COPD patients and was involved in inflammatory factors and MUC5AC expression after cold stimulation through the ERK and NF-κB pathways. PMID:27184164

  1. Effect of anticholinesterase agents on airway epithelial function. Annual report, 15 July 1986-14 July 1987

    SciTech Connect

    Marin, M.G.

    1987-08-01

    Irreversible anticholinesterase compounds have potential serious deleterious health effects when employed as chemical warfare agents. Intoxication with these agents causes an accumulation of acetylcholine at nerve muscle and nerve gland junctions. Because tracheal submucosal glands have rich cholinergic innervation, we hypothesized that exposure to anticholinesterase agents, such as soman, would stimulate glandular secretion. This would cause pathological changes in the important lung defense mechanism of mucociliary clearance. Despite the potential importance of anticholinesterase agents on lung function, little information was available concerning the effects of these agents on mucociliary transport. During the past year, studies were completed designed to determine the effect of soman and its antidotes on mucociliary transport. Mucociliary transport was measured on radiopertechnetate-tagged microaggregated albumin in anesthetized ferrets, utilizing two sodium-iodized crystals, collimated to detect the rate of tracheal movement over a 19-mm length of airway. In experimental animals, the author injected intravenously either soman or soman plus an antidote or an antidote alone, between the two periods. Soman resulted in a significant dose-related increase in mucociliary transport relative to control. Neither atropine nor pralidoxime alone had a significant effect on transport rate. While atropine injected simultaneously with soman blocked the stimulatory effects of soman on transport, pralidoxime failed to alter this increase in transport. Studies performed were also to determine the effect of soman and its antidotes on submucosal glandular secretion in vivo.

  2. S100A8, S100A9 and S100A12 activate airway epithelial cells to produce MUC5AC via extracellular signal-regulated kinase and nuclear factor-κB pathways.

    PubMed

    Kang, Jin Hyun; Hwang, Sae Mi; Chung, Il Yup

    2015-01-01

    Airway mucus hyperproduction is a common feature of chronic airway diseases such as severe asthma, chronic obstructive pulmonary disease and cystic fibrosis, which are closely associated with neutrophilic airway inflammation. S100A8, S100A9 and S100A12 are highly abundant proteins released by neutrophils and have been identified as important biomarkers in many inflammatory diseases. Herein, we report a new role for S100A8, S100A9 and S100A12 for producing MUC5AC, a major mucin protein in the respiratory tract. All three S100 proteins induced MUC5AC mRNA and the protein in normal human bronchial epithelial cells as well as NCI-H292 lung carcinoma cells in a dose-dependent manner. A Toll-like receptor 4 (TLR4) inhibitor almost completely abolished MUC5AC expression by all three S100 proteins, while neutralization of the receptor for advanced glycation end-products (RAGE) inhibited only S100A12-mediated production of MUC5AC. The S100 protein-mediated production of MUC5AC was inhibited by the pharmacological agents that block prominent signalling molecules for MUC5AC expression, such as mitogen-activated protein kinases, nuclear factor-κB (NF-κB) and epidermal growth factor receptor. S100A8, S100A9 and S100A12 equally elicited both phosphorylation of extracellular signal-regulated kinase (ERK) and nuclear translocation of NF-κB/degradation of cytosolic IκB with similar kinetics through TLR4. In contrast, S100A12 preferentially activated the ERK pathway rather than the NF-κB pathway through RAGE. Collectively, these data reveal the capacity of these three S100 proteins to induce MUC5AC production in airway epithelial cells, suggesting that they all serve as key mediators linking neutrophil-dominant airway inflammation to mucin hyperproduction. PMID:24975020

  3. Mucolytic treatment with N-acetylcysteine L-lysinate metered dose inhaler in dogs: airway epithelial function changes.

    PubMed

    Tomkiewicz, R P; App, E M; Coffiner, M; Fossion, J; Maes, P; King, M

    1994-01-01

    N-acetylcysteine L-lysinate Nacystelyn (L-NAC) is a newly synthesized mucolytic agent, of which the action in vivo has not been well defined. In six healthy mongrel dogs, the rheological properties of mucus, its mucociliary and cough clearability, and the transepithelial potential difference (PD) of the tracheobronchial epithelium were evaluated after placebo and L-NAC metered dose inhaler (MDI) aerosols. The principal index of mucus rigidity, log G*, decreased at all airway sites with L-NAC administration, i.e. the mucus became less rigid and more deformable (the overall change in G* was 0.29 log units, i.e. ca. twofold decrease). The viscoelasticity-derived mucus transportability parameters, mucociliary (MCI) and cough (CCI) clearability indices, increased with L-NAC MDI, particularly CCI, which predicts the effect of mucus rheology on cough clearability. PD increased significantly with L-NAC administration at all measurement sites, which appears to be a novel effect for a direct acting mucolytic agent. Tracheal mucus linear velocity (TMV) increased after L-NAC compared with placebo, as did the normalized frog palate transport rate (NFPTR). The increase in NFPTR was greater than that predicted from the mucus rheological properties alone, suggesting that L-NAC still resident in the collected mucus stimulated the frog palate cilia. The index of mucus flux, the collection rate in mg.min-1, was higher with L-NAC compared with placebo. From our results, we conclude that L-NAC shows potential benefit in terms of improving mucus rheological properties and clearability. It may act, in part, by stimulating the fresh secretion of mucus of lower viscoelasticity. The stimulation of mucociliary clearance could be related to ion flux changes, as indicated by the increase in PD. PMID:8143836

  4. Oxidant stress stimulates anion secretion from the human airway epithelial cell line calu-3: implications for cystic fibrosis lung disease

    PubMed Central

    Cowley, Elizabeth A; Linsdell, Paul

    2002-01-01

    Exposure to reactive oxygen species (ROS) is associated with tissue damage in the lung and may be a common element in the pathogenesis of all inflammatory lung diseases. Exposure to the ROS hydrogen peroxide (H2O2) evoked a rapid increase in transepithelial anion secretion across monolayers of the human submucosal gland serous cell line Calu-3. This increase was almost entirely abolished by the addition of diphenylamine-2-carboxylate (DPC), implicating the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel in the response. The response was also reduced by inhibitors of basolateral K+ channels. Studies of electrically isolated apical and basolateral membranes revealed that H2O2 stimulated both apical Cl− and basolateral K+ conductances (GCl and GK). Apical GCl was sensitive to DPC, but unaffected by 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), suggesting that CFTR is the major anion conduction pathway mediating the response to H2O2. Additionally, H2O2 had no effect on GCl in the presence of the adenylate cyclase inhibitor SQ22536 or following maximal stimulation of GCl with forskolin, implicating the cAMP-dependent protein kinase pathway in the apical response to H2O2. Basolateral GK was reduced by the K+ channel inhibitors clotrimazole and clofilium, indicating roles for KCNN4 and KCNQ1 in the H2O2-stimulated response. We propose that ROS-stimulated anion secretion from serous cells plays an important role in keeping the airways clear from damaging radicals that could potentially initiate tissue destruction. Our finding that this response is CFTR dependent suggests that an important host defence mechanism would be dysfunctional in the cystic fibrosis (CF) lung. Loss of this compensatory protective mechanism could expose the CF lung to ROS for extended periods, which could be important in the pathogenesis of CF lung disease. PMID:12181292

  5. Oxidant stress stimulates anion secretion from the human airway epithelial cell line Calu-3: implications for cystic fibrosis lung disease.

    PubMed

    Cowley, Elizabeth A; Linsdell, Paul

    2002-08-15

    Exposure to reactive oxygen species (ROS) is associated with tissue damage in the lung and may be a common element in the pathogenesis of all inflammatory lung diseases. Exposure to the ROS hydrogen peroxide (H2O2) evoked a rapid increase in transepithelial anion secretion across monolayers of the human submucosal gland serous cell line Calu-3. This increase was almost entirely abolished by the addition of diphenylamine-2-carboxylate (DPC), implicating the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel in the response. The response was also reduced by inhibitors of basolateral K+ channels. Studies of electrically isolated apical and basolateral membranes revealed that H2O2 stimulated both apical Cl- and basolateral K+ conductances (G(Cl) and G(K)). Apical G(Cl) was sensitive to DPC, but unaffected by 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), suggesting that CFTR is the major anion conduction pathway mediating the response to H2O2. Additionally, H2O2 had no effect on G(Cl) in the presence of the adenylate cyclase inhibitor SQ22536 or following maximal stimulation of G(Cl) with forskolin, implicating the cAMP-dependent protein kinase pathway in the apical response to H2O2. Basolateral G(K) was reduced by the K+ channel inhibitors clotrimazole and clofilium, indicating roles for KCNN4 and KCNQ1 in the H2O2-stimulated response. We propose that ROS-stimulated anion secretion from serous cells plays an important role in keeping the airways clear from damaging radicals that could potentially initiate tissue destruction. Our finding that this response is CFTR dependent suggests that an important host defence mechanism would be dysfunctional in the cystic fibrosis (CF) lung. Loss of this compensatory protective mechanism could expose the CF lung to ROS for extended periods, which could be important in the pathogenesis of CF lung disease. PMID:12181292

  6. Infection of Polarized Airway Epithelial Cells by Normal and Small-Colony Variant Strains of Staphylococcus aureus Is Increased in Cells with Abnormal Cystic Fibrosis Transmembrane Conductance Regulator Function and Is Influenced by NF-κB ▿

    PubMed Central

    Mitchell, Gabriel; Grondin, Gilles; Bilodeau, Ginette; Cantin, André M.; Malouin, François

    2011-01-01

    The infection of nonphagocytic host cells by Staphylococcus aureus and more particularly by small-colony variants (SCVs) may contribute to the persistence of this pathogen in the lungs of cystic fibrosis (CF) patients. The development of chronic infections is also thought to be facilitated by the proinflammatory status of CF airways induced by an activation of NF-κB. The aim of this study was to compare the infection of non-CF and CF-like airway epithelial cells by S. aureus strains (normal and SCVs) and to determine the impact of the interaction between cystic fibrosis transmembrane conductance regulator (CFTR) and NF-κB on the infection level of these cells by S. aureus. We developed an S. aureus infection model using polarized airway epithelial cells grown at the air-liquid interface and expressing short hairpin RNAs directed against CFTR to mimic the CF condition. A pair of genetically related CF coisolates with the normal and SCV phenotypes was characterized and used. Infection of both cell lines (non-CF and CF-like) was more productive with the SCV strain than with its normal counterpart. However, both normal and SCV strains infected more CF-like than non-CF cells. Accordingly, inhibition of CFTR function by CFTRinh-172 increased the S. aureus infection level. Experimental activation of NF-κB also increased the level of infection of polarized pulmonary epithelial cells by S. aureus, an event that could be associated with that observed when CFTR function is inhibited or impaired. This study supports the hypothesis that the proinflammatory status of CF tissues facilitates the infection of pulmonary epithelial cells by S. aureus. PMID:21708986

  7. Relationship between surface tension of upper airway lining liquid and upper airway collapsibility during sleep in obstructive sleep apnea hypopnea syndrome.

    PubMed

    Kirkness, Jason P; Madronio, Melanie; Stavrinou, Rosie; Wheatley, John R; Amis, Terence C

    2003-11-01

    Lowering surface tension (gamma) of upper airway lining liquid (UAL) reduces upper airway opening (anesthetized humans) and closing (anesthetized rabbits) pressures. We now hypothesize that in sleeping obstructive sleep apnea hypopnea syndrome (OSAHS) patients lowering gamma of UAL will enhance upper airway stability and decrease the severity of sleep-disordered breathing. Nine OSAHS patients [respiratory disturbance index (RDI): 49 +/- 8 (SE) events/h, diagnostic night] participated in a two-part, one-night, polysomnography study. In the first part, upper airway closing pressures (during non-rapid eye movement sleep, Pcrit) were measured and samples of UAL (awake) were obtained before and after 2.5 ml of surfactant (Exosurf, Glaxo Smith Kline) was instilled into the posterior pharynx. The gamma of UAL was determined with the use of the "pull-off" force technique. In the second part, subjects received a second application of 2.5 ml of surfactant and then slept the remainder of the night (205 +/- 30 min). Instillation of surfactant decreased the gamma of UAL from 60.9 +/- 3.1 mN/m (control) to 45.2 +/- 2.5 mN/m (surfactant group) (n = 9, P < 0.001). Pcrit decreased from 1.19 +/- 1.14 cmH2O (control) to -0.56 +/- 1.15 cmH2O (surfactant group) (n = 7, P < 0.02). Compared with the second half of diagnostic night, surfactant decreased RDI from 51 +/- 8 to 35 +/- 8 events/h (n = 9, P < 0.03). The fall in RDI (deltaRDI) correlated with the fall in gamma of UAL (deltagamma) (deltaRDI = 1.8 x deltagamma, r = 0.68, P = 0.04). Hypopneas decreased approximately 50% from 42 +/- 8 to 20 +/- 5 events/h (n = 9, P < 0.03, paired t-test). The gamma of UAL measured the next morning remained low at 49.5 +/- 2.7 mN/m (n = 9, P < 0.001, ANOVA, compared with control). In conclusion, instillation of surfactant reduced the gamma of UAL in OSAHS patients and decreased Pcrit and the occurrence of hypopneas. Therapeutic manipulation of gamma of UAL may be beneficial in reducing the severity

  8. The TAK1→IKKβ→TPL2→MKK1/MKK2 Signaling Cascade Regulates IL-33 Expression in Cystic Fibrosis Airway Epithelial Cells Following Infection by Pseudomonas aeruginosa

    PubMed Central

    Farias, Raquel; Rousseau, Simon

    2016-01-01

    In cystic fibrosis (CF), chronic respiratory infections result in an exaggerated and uncontrolled inflammatory response that ultimately lead to a decrease in pulmonary function. We have previously described the presence of the alarmin IL-33 in lung explants from CF patients. The signals regulating IL-33 expression in the airway epithelium following a gram-negative bacterial infection are currently unknown. Our objective was to characterize the pathways in CF airway<