Diesel exhaust particles up-regulate interleukin-17A expression via ROS/NF-κB in airway epithelium.

PubMed

Weng, Chih-Ming; Lee, Meng-Jung; He, Jung-Re; Chao, Ming-Wei; Wang, Chun-Hua; Kuo, Han-Pin

2018-05-01

IL-17A is implicated in many aspects of pathogenesis of severe asthma, including inducing neutrophilic inflammation, airway hyperresponsiveness, steroid insensitivity and airway remodeling. Diesel exhaust particles (DEP) emission from vehicles has been shown to expand Th17 cells to increase IL-17A release that contributes to DEP-mediated exacerbation of asthma severity. It is not known whether non-immune cells in airways may also release IL-17A in response to DEP exposure. In this study, We found IL-17A expression was upregulated in the epithelium of severe allergic asthma patients from high road traffic pollution areas compared to those in low. Furthermore, we found DEP concentration-dependently increased IL-17A synthesis and release by 122.3 ± 15.72% and 235.5 ± 18.37%, respectively in primary bronchial epithelial cells (PBEC), accompanied with increased ROS production. Pretreatment of ROS scavenger (NAC) significantly inhibited DEP-induced IL-17A mRNA expression. DEP-induced IκBα degradation can be inhibited by NAC. We also found DEP increased p65 and RelB subunits expression, and pretreatment of NF-κB inhibitor (SN50) also inhibited DEP-induced IL-17A expression. We further found DEP increased NF-κB subunit RelB recruitment to IL-17A promoter in PBEC and airway tissue of severe allergic asthma patients from high road traffic pollution areas. These results indicate DEP stimulates IL-17A expression in airway epithelium through ROS/NF-κB pathway, and provide a possible link between traffic pollution exposure and IL-17A-related responses in severe allergic asthma patients. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of azelastine on sulphur dioxide induced impairment of ciliary motility in airway epithelium.

PubMed Central

Tamaoki, J; Chiyotani, A; Sakai, N; Takeyama, K; Konno, K

1993-01-01

OBJECTIVE--The effect of azelastine on airway mucociliary transport function was studied by measuring ciliary motility of human bronchial epithelium in vitro with a photoelectric method. METHOD--Bronchial epithelial cells were obtained by fibreoptic bronchoscopy, mounted in a Rose chamber, and perfused with Krebs-Henseleit solution. The preparations were placed on a microscope stage equipped with an illuminator, and the variations of light intensity caused by ciliary beating were detected by a photometer. RESULTS--The addition of azelastine to the perfusate increased ciliary beat frequency (CBF) in a dose dependent manner without ciliary discoordination. The mean (SE) maximal increase from the baseline value and the concentration required to produce a half maximal effect were 27.0 (4.2)% and 9.2 x 10(-6) mol/l, respectively. Exposure of the cells to the perfusate containing 3 ppm sulphur dioxide rapidly decreased CBF by 59.2 (5.0)%, and was accompanied by a reduction in intracellular cyclic AMP levels from 38.1 (4.3) to 10.1 (2.4) pmol/mg protein. This effect was prevented by pretreatment of cells with azelastine in a dose dependent manner. CONCLUSIONS--Azelastine not only stimulates ciliary motility of airway epithelium and hence mucociliary transport function, but may also protect against sulphur dioxide induced ciliary dysfunction, probably by inhibiting intracellular cyclic AMP loss. PMID:8322244

Hypoxia-inducible factor-1 signalling promotes goblet cell hyperplasia in airway epithelium

PubMed Central

Polosukhin, Vasiliy V; Cates, Justin M; Lawson, William E; Milstone, Aaron P; Matafonov, Anton G; Massion, Pierre P; Lee, Jae Woo; Randell, Scott H; Blackwell, Timothy S

2018-01-01

Goblet cell hyperplasia is a common feature of chronic obstructive pulmonary disease (COPD) airways, but the mechanisms that underlie this epithelial remodelling in COPD are not understood. Based on our previous finding of hypoxia-inducible factor-1α (HIF-1α) nuclear localization in large airways from patients with COPD, we investigated whether hypoxia-inducible signalling could influence the development of goblet cell hyperplasia. We evaluated large airway samples obtained from 18 lifelong non-smokers and 13 former smokers without COPD, and 45 former smokers with COPD. In these specimens, HIF-1α nuclear staining occurred almost exclusively in COPD patients in areas of airway remodelling. In COPD patients, 93.2 ± 3.9% (range 65 – 100%) of goblet cells were HIF-1α positive in areas of goblet cell hyperplasia, whereas nuclear HIF-1α was not detected in individuals without COPD or in normal-appearing pseudostratified epithelium from COPD patients. To determine the direct effects of hypoxia-inducible signalling on epithelial cell differentiation in vitro, human bronchial epithelial cells (HBECs) were grown in air-liquid interface cultures under hypoxia (1% O2) or following treatment with a selective HIF-1α stabilizer, (2R)-[(4-biphenylylsulphonyl)amino]-N-hydroxy-3-phenyl-propionamide (BiPS). HBECs grown in hypoxia or with BiPS treatment were characterized by HIF-1α activation, carbonic anhydrase IX expression, mucus-producing cell hyperplasia and increased expression of MUC5AC. Analysis of signal transduction pathways in cells with HIF-1α activation showed increased ERK1/2 phosphorylation without activation of epidermal growth factor receptor, Ras, PI3K-Akt or STAT6. These data indicate an important effect of hypoxia-inducible signalling on airway epithelial cell differentiation and identify a new potential target to limit mucus production in COPD. PMID:21557221

The small airway epithelium as a target for the adverse pulmonary effects of silver nanoparticle inhalation.

PubMed

Guo, Chang; Buckley, Alison; Marczylo, Tim; Seiffert, Joanna; Römer, Isabella; Warren, James; Hodgson, Alan; Chung, Kian Fan; Gant, Timothy W; Smith, Rachel; Leonard, Martin O

2018-05-11

Experimental modeling to identify specific inhalation hazards for nanomaterials has in the main focused on in vivo approaches. However, these models suffer from uncertainties surrounding species-specific differences and cellular targets for biologic response. In terms of pulmonary exposure, approaches which combine 'inhalation-like' nanoparticulate aerosol deposition with relevant human cell and tissue air-liquid interface cultures are considered an important complement to in vivo work. In this study, we utilized such a model system to build on previous results from in vivo exposures, which highlighted the small airway epithelium as a target for silver nanoparticle (AgNP) deposition. RNA-SEQ was used to characterize alterations in mRNA and miRNA within the lung. Organotypic-reconstituted 3D human primary small airway epithelial cell cultures (SmallAir) were exposed to the same spark-generated AgNP and at the same dose used in vivo, in an aerosol-exposure air-liquid interface (AE-ALI) system. Adverse effects were characterized using lactate, LDH release and alterations in mRNA and miRNA. Modest toxicological effects were paralleled by significant regulation in gene expression, reflective mainly of specific inflammatory events. Importantly, there was a level of concordance between gene expression changes observed in vitro and in vivo. We also observed a significant correlation between AgNP and mass equivalent silver ion (Ag + ) induced transcriptional changes in SmallAir cultures. In addition to key mechanistic information relevant for our understanding of the potential health risks associated with AgNP inhalation exposure, this work further highlights the small airway epithelium as an important target for adverse effects.

Toll-like receptor 2 is upregulated by hog confinement dust in an IL-6 dependent manner in the airway epithelium

PubMed Central

Bailey, KL; Poole, JA; Mathisen, TL; Wyatt, TA; Von Essen, SG; Romberger, DJ

2009-01-01

Hog confinement workers are at high risk to develop chronic bronchitis as a result of their exposure to organic dust. Chronic bronchitis is characterized by inflammatory changes of the airway epithelium. A key mediator in inflammation is Toll-like receptor 2 (TLR2). We investigated the role of TLR2 in pulmonary inflammation induced by hog confinement dust. Normal Human Bronchial Epithelial Cells (NHBE) were grown in culture and exposed to hog confinement dust extract. Hog confinement dust upregulated airway epithelial cell TLR2 mRNA in a concentration and time-dependent manner using real-time PCR. There was a similar increase in TLR2 protein at 48 hours as shown by Western blot. TLR2 was upregulated on the surface of airway epithelial cells as shown by flow cytometry. A similar upregulation of pulmonary TLR2 mRNA and protein was shown in a murine model of hog confinement dust exposure. Hog confinement dust is known to stimulate epithelial cells to produce IL-6. In order to determine whether TLR2 expression was being regulated by IL-6, the production of IL-6 was blocked using an IL-6 neutralizing antibody. This resulted in attenuation of the dust-induced upregulation of TLR2. To further demonstrate the importance of IL-6 in the regulation of TLR2, NHBE were directly stimulated with recombinant human IL-6. IL-6 alone was able to upregulate TLR2 in airway epithelial cells. Hog confinement dust upregulates TLR2 in the airway epithelium through an IL-6 dependent mechanism. PMID:18359883

Decreased expression of monocarboxylate transporter 1 and 4 in the branching airway epithelium of nitrofen-induced congenital diaphragmatic hernia.

PubMed

Takahashi, Toshiaki; Friedmacher, Florian; Zimmer, Julia; Puri, Prem

2016-06-01

Monocarboxylate transporters (MCTs) are crucial for the maintenance of intracellular pH homeostasis in developing fetal lungs. MCT1/4 is strongly expressed by epithelial airway cells throughout lung branching morphogenesis. Functional inhibition of MCT1/4 in fetal rat lung explants has been shown to result in airway defects similar to pulmonary hypoplasia (PH) in congenital diaphragmatic hernia (CDH). We hypothesized that pulmonary expression of MCT1/4 is decreased during lung branching morphogenesis in the nitrofen model of CDH-associated PH. Timed-pregnant rats received nitrofen or vehicle on gestational day 9 (D9). Fetuses were harvested on D15, D18, and D21, and divided into control and nitrofen-exposed group. Pulmonary gene expression levels of MCT1/4 were analyzed by qRT-PCR. Immunofluorescence staining for MCT1/4 was combined with E-cadherin in order to evaluate protein expression in branching airway tissue. Relative mRNA levels of MCT1/4 were significantly reduced in lungs of nitrofen-exposed fetuses on D15, D18, and D21 compared to controls. Confocal laser scanning microscopy confirmed markedly decreased immunofluorescence of MCT1/4 in distal bronchial and primitive alveolar epithelium of nitrofen-exposed fetuses on D15, D18, and D21 compared to controls. Decreased expression of MCT1/4 in distal airway epithelium may disrupt lung branching morphogenesis and thus contribute to the development of PH in the nitrofen-induced CDH model. Copyright © 2016 Elsevier Inc. All rights reserved.

SPDEF regulates goblet cell hyperplasia in the airway epithelium

PubMed Central

Park, Kwon-Sik; Korfhagen, Thomas R.; Bruno, Michael D.; Kitzmiller, Joseph A.; Wan, Huajing; Wert, Susan E.; Khurana Hershey, Gurjit K.; Chen, Gang; Whitsett, Jeffrey A.

2007-01-01

Goblet cell hyperplasia and mucous hypersecretion contribute to the pathogenesis of chronic pulmonary diseases including cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In the present work, mouse SAM pointed domain-containing ETS transcription factor (SPDEF) mRNA and protein were detected in subsets of epithelial cells lining the trachea, bronchi, and tracheal glands. SPDEF interacted with the C-terminal domain of thyroid transcription factor 1, activating transcription of genes expressed selectively in airway epithelial cells, including Sftpa, Scgb1a1, Foxj1, and Sox17. Expression of Spdef in the respiratory epithelium of adult transgenic mice caused goblet cell hyperplasia, inducing both acidic and neutral mucins in vivo, and stainined for both acidic and neutral mucins in vivo. SPDEF expression was increased at sites of goblet cell hyperplasia caused by IL-13 and dust mite allergen in a process that was dependent upon STAT-6. SPDEF was induced following intratracheal allergen exposure and after Th2 cytokine stimulation and was sufficient to cause goblet cell differentiation of Clara cells in vivo. PMID:17347682

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

Chlorinated pool attendance, airway epithelium defects and the risks of allergic diseases in adolescents: Interrelationships revealed by circulating biomarkers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernard, Alfred, E-mail: Alfred.bernard@uclouvain.be; Nickmilder, Marc; Dumont, Xavier

It has been suggested that allergic diseases might be epithelial disorders driven by various environmental stressors but the epidemiological evidence supporting this concept is limited. In a cross-sectional study of 835 school adolescents (365 boys; mean age, 15.5 yr), we measured the serum concentrations of Club cell protein (CC16), surfactant-associated protein D (SP-D) and of total and aeroallergen-specific IgE. We used the serum CC16/SP-D concentration ratio as an index integrating changes in the permeability (SP-D) and secretory function (CC16) of the airway epithelium. In both sexes, early swimming in chlorinated pools emerged as the most consistent and strongest predictor ofmore » low CC16 and CC16/SP-D ratio in serum. Among girls, a low CC16/SP-D ratio was associated with increased odds (lowest vs. highest tertile) for pet sensitization (OR 2.97, 95% CI 1.19–8.22) and for hay fever in subjects sensitized to pollen (OR 4.12, 95% CI 1.28–14.4). Among boys, a low CC16/SP-D ratio was associated with increased odds for house-dust mite (HDM) sensitization (OR 2.01, 95% CI 1.11–3.73), for allergic rhinitis in subjects sensitized to HDM (OR 3.52, 95% CI 1.22–11.1) and for asthma in subjects sensitized to any aeroallergen (OR 3.38, 95% CI 1.17–11.0), HDM (OR 5.20, 95% CI 1.40–24.2) or pollen (OR 5.82, 95% CI 1.51–27.4). Odds for allergic sensitization or rhinitis also increased with increasing SP-D or decreasing CC16 in serum. Our findings support the hypothesis linking the development of allergic diseases to epithelial barrier defects due to host factors or environmental stressors such as early swimming in chlorinated pools. - Highlights: • We conducted a cross-sectional study of 835 school adolescents. • The airway epithelium integrity was evaluated by measuring serum pneumoproteins. • The risk of allergic diseases was associated with a defective airway epithelium. • Childhood swimming in chlorinated pools can cause persistent epithelial

Finding genes discriminating smokers from non-smokers by applying a growing self-organizing clustering method to large airway epithelium cell microarray data.

PubMed

Shahdoust, Maryam; Hajizadeh, Ebrahim; Mozdarani, Hossein; Chehrei, Ali

2013-01-01

Cigarette smoking is the major risk factor for development of lung cancer. Identification of effects of tobacco on airway gene expression may provide insight into the causes. This research aimed to compare gene expression of large airway epithelium cells in normal smokers (n=13) and non-smokers (n=9) in order to find genes which discriminate the two groups and assess cigarette smoking effects on large airway epithelium cells. Genes discriminating smokers from non-smokers were identified by applying a neural network clustering method, growing self-organizing maps (GSOM), to microarray data according to class discrimination scores. An index was computed based on differentiation between each mean of gene expression in the two groups. This clustering approach provided the possibility of comparing thousands of genes simultaneously. The applied approach compared the mean of 7,129 genes in smokers and non-smokers simultaneously and classified the genes of large airway epithelium cells which had differently expressed in smokers comparing with non-smokers. Seven genes were identified which had the highest different expression in smokers compared with the non-smokers group: NQO1, H19, ALDH3A1, AKR1C1, ABHD2, GPX2 and ADH7. Most (NQO1, ALDH3A1, AKR1C1, H19 and GPX2) are known to be clinically notable in lung cancer studies. Furthermore, statistical discriminate analysis showed that these genes could classify samples in smokers and non-smokers correctly with 100% accuracy. With the performed GSOM map, other nodes with high average discriminate scores included genes with alterations strongly related to the lung cancer such as AKR1C3, CYP1B1, UCHL1 and AKR1B10. This clustering by comparing expression of thousands of genes at the same time revealed alteration in normal smokers. Most of the identified genes were strongly relevant to lung cancer in the existing literature. The genes may be utilized to identify smokers with increased risk for lung cancer. A large sample study is now

The Idiopathic Pulmonary Fibrosis Honeycomb Cyst Contains A Mucocilary Pseudostratified Epithelium

PubMed Central

Seibold, Max A.; Smith, Russell W.; Urbanek, Cydney; Groshong, Steve D.; Cosgrove, Gregory P.; Brown, Kevin K.; Schwarz, Marvin I.

2013-01-01

Background We previously identified a MUC5B gene promoter-variant that is a risk allele for sporadic and familial Idiopathic Pulmonary Fibrosis/Usual Interstitial Pneumonia (IPF/UIP). This allele was strongly associated with increased MUC5B gene expression in lung tissue from unaffected subjects. Despite the strong association of this airway epithelial marker with disease, little is known of mucin expressing structures or of airway involvement in IPF/UIP. Methods Immunofluorescence was used to subtype mucus cells according to MUC5B and MUC5AC expression and to identify ciliated, basal, and alveolar type II (ATII) cells in tissue sections from control and IPF/UIP subjects. Staining patterns were quantified for distal airways (Control and IPF/UIP) and in honeycomb cysts (HC). Results MUC5B-expressing cells (EC) were detected in the majority of control distal airways. MUC5AC-EC were identified in half of these airways and only in airways that contained MUC5B-EC. The frequency of MUC5B+ and MUC5AC+ distal airways was increased in IPF/UIP subjects. MUC5B-EC were the dominant mucus cell type in the HC epithelium. The distal airway epithelium from control and IPF/UIP subjects and HC was populated by basal and ciliated cells. Most honeycombing regions were distinct from ATII hyperplasic regions. ATII cells were undetectable in the overwhelming majority of HC. Conclusions The distal airway contains a pseudostratified mucocilary epithelium that is defined by basal epithelial cells and mucus cells that express MUC5B predominantly. These data suggest that the HC is derived from the distal airway. PMID:23527003

Neuronal NOS localises to human airway cilia.

PubMed

Jackson, Claire L; Lucas, Jane S; Walker, Woolf T; Owen, Holly; Premadeva, Irnthu; Lackie, Peter M

2015-01-30

Airway NO synthase (NOS) isoenzymes are responsible for rapid and localised nitric oxide (NO) production and are expressed in airway epithelium. We sought to determine the localisation of neuronal NOS (nNOS) in airway epithelium due to the paucity of evidence. Sections of healthy human bronchial tissue in glycol methacrylate resin and human nasal polyps in paraffin wax were immunohistochemically labelled and reproducibly demonstrated nNOS immunoreactivity, particularly at the proximal portion of cilia; this immunoreactivity was blocked by a specific nNOS peptide fragment. Healthy human epithelial cells differentiated at an air-liquid interface (ALI) confirmed the presence of all three NOS isoenzymes by immunofluorescence labelling. Only nNOS immunoreactivity was specific to the ciliary axonemeand co-localised with the cilia marker β-tubulin in the proximal part of the ciliary axoneme. We report a novel localisation of nNOS at the proximal portion of cilia in airway epithelium and conclude that its independent and local regulation of NO levels is crucial for normal cilia function. Copyright © 2014 Elsevier Inc. All rights reserved.

Basal Cells Are a Multipotent Progenitor Capable of Renewing the Bronchial Epithelium

PubMed Central

Hong, Kyung U.; Reynolds, Susan D.; Watkins, Simon; Fuchs, Elaine; Stripp, Barry R.

2004-01-01

Commitment of the pulmonary epithelium to bronchial and bronchiolar airway lineages occurs during the transition from pseudoglandular to cannalicular phases of lung development, suggesting that regional differences exist with respect to the identity of stem and progenitor cells that contribute to epithelial maintenance in adulthood. We previously defined a critical role for Clara cell secretory protein-expressing (CE) cells in renewal of bronchiolar airway epithelium following injury. Even though CE cells are also the principal progenitor for maintenance of the bronchial airway epithelium, CE cell injury is resolved through a mechanism involving recruitment of a second progenitor cell population that we now identify as a GSI-B4 reactive, cytokeratin-14-expressing basal cell. These cells exhibit multipotent differentiation capacity as assessed by analysis of cellular phenotype within clones of LacZ-tagged cells. Clones were derived from K14-expressing cells tagged in a cell-type-specific fashion by ligand-regulable Cre recombinase-mediated genomic rearrangement of the ROSA26 recombination substrate allele. We conclude that basal cells represent an alternative multipotent progenitor cell population of bronchial airways and that progenitor cell selection is dictated by the type of airway injury. PMID:14742263

Demonstration of carboxylesterase in cytology samples of human nasal respiratory epithelium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodgers, D.A.; Nikula, K.J.; Avila, K.

1995-12-01

The epithelial lining of the nasal airways is a target for responses induced by a variety of toxicant exposures. The high metabolic capacity of this tissue has been suggested to play a role in both protection of the airways through detoxication of certain toxicants, as well as in activation of other compounds to more toxic metabolites. Specifically, nasal carboxylesterase (CE) has been shown to mediate the toxicity of inhaled esters and acrylates by converting them to more toxic acid and alcohol metabolites which can be cytotoxic and/or carcinogenic to the nasal mucosa. Due to difficulties in extrapolating rodent models tomore » human, new paradigms using human cells and tissues are essential to understanding and evaluating the metabolic processes in human nasal epithelium.« less

Alcohol and Airways Function in Health and Disease

PubMed Central

Sisson, Joseph H.

2007-01-01

The volatility of alcohol promotes the movement of alcohol from the bronchial circulation across the airway epithelium and into the conducting airways of the lung. The exposure of the airways through this route likely accounts for many of the biologic effects of alcohol on lung airway functions. The impact of alcohol on lung airway functions is dependent on the concentration, duration and route of exposure. Brief exposure to mild concentrations of alcohol may enhance mucociliary clearance, stimulates bronchodilation and probably attenuates the airway inflammation and injury observed in asthma and COPD. Prolonged and heavy exposure to alcohol impairs mucociliary clearance, may complicate asthma management and likely worsens outcomes including lung function and mortality in COPD patients. Non-alcohol congeners and alcohol metabolites act as triggers for airway disease exacerbations especially in atopic asthmatics and in Asian populations who have a reduced capacity to metabolize alcohol. Research focused on the mechanisms of alcohol-mediated changes in airway functions has identified specific mechanisms that mediate alcohol effects within the lung airways. These include prominent roles for the second messengers calcium and nitric oxide, regulatory kinases including PKG and PKA, alcohol and acetaldehyde-metabolizing enzymes such as aldehyde dehydrogenase type 2 (ALDH2). The role alcohol may play in the pathobiology of airway mucus, bronchial blood flow, airway smooth muscle regulation and the interaction with other airway exposure agents, such as cigarette smoke, represent opportunities for future investigation. PMID:17764883

Alcohol and airways function in health and disease.

PubMed

Sisson, Joseph H

2007-08-01

The volatility of alcohol promotes the movement of alcohol from the bronchial circulation across the airway epithelium and into the conducting airways of the lung. The exposure of the airways through this route likely accounts for many of the biologic effects of alcohol on lung airway functions. The effect of alcohol on lung airway functions is dependent on the concentration, duration, and route of exposure. Brief exposure to mild concentrations of alcohol may enhance mucociliary clearance, stimulates bronchodilation, and probably attenuates the airway inflammation and injury observed in asthma and chronic obstructive pulmonary disease (COPD). Prolonged and heavy exposure to alcohol impairs mucociliary clearance, may complicate asthma management, and likely worsens outcomes including lung function and mortality in COPD patients. Nonalcohol congeners and alcohol metabolites act as triggers for airway disease exacerbations especially in atopic asthmatics and in Asian populations who have a reduced capacity to metabolize alcohol. Research focused on the mechanisms of alcohol-mediated changes in airway functions has identified specific mechanisms that mediate alcohol effects within the lung airways. These include prominent roles for the second messengers calcium and nitric oxide, regulatory kinases including PKG and PKA, alcohol- and acetaldehyde-metabolizing enzymes such as aldehyde dehydrogenase 2. The role alcohol may play in the pathobiology of airway mucus, bronchial blood flow, airway smooth muscle regulation, and the interaction with other airway exposure agents, such as cigarette smoke, represents opportunities for future investigation.

Glucocorticoids inhibit sulfur mustard-induced airway muscle hyperresponsiveness to substance P.

PubMed

Calvet, J H; D'Ortho, M P; Jarreau, P H; Levame, M; Harf, A; Macquin-Mavier, I

1994-11-01

To explore the mechanisms of airway hyperreactivity to aerosolized substance P observed in guinea pigs 14 days after intratracheal injection of sulfur mustard (SM), we studied the effects of epithelium removal and inhibition of neutral endopeptidase (NEP) activity on airway muscle responsiveness. Tracheal rings from SM-intoxicated guinea pigs expressed a greater contractile response to substance P than rings from nonintoxicated guinea pigs. After epithelium removal or incubation with the NEP inhibitor phosphoramidon, the contractile responses of tracheal rings to substance P did not differ in guinea pigs injected with SM or ethanol (SM solvent). Treatment of the guinea pigs with betamethasone for 7 days before measurement abolished the airway muscle hyperresponsiveness observed in untreated SM-intoxicated guinea pigs and partially restored tracheal epithelium NEP activity. In addition, the tracheal epithelium height and cell density of SM-intoxicated guinea pigs treated with betamethasone were significantly greater than in those without betamethasone. These results demonstrate that SM intoxication induces airway muscle hyperresponsiveness to substance P by reducing tracheal epithelial NEP activity and that glucocorticoids might inhibit this hyperresponsiveness by increasing this activity.

Levcromakalim- and isoprenaline-induced relaxation of human isolated airways--role of the epithelium and of K+ channel activation.

PubMed

Black, J L; Johnson, P R; McKay, K O; Carey, D; Armour, C L

1994-06-01

In this study we have investigated the mechanism of action of levcromakalim and isoprenaline in human isolated airways with respect to the K+ channels they activate and the possibility that these smooth muscle relaxants activate K+ channels on the airway epithelium. Mechanical removal of the epithelial layer (mean percentage of epithelium present 20 +/- 3%, n = 20 tissues) did not affect the relaxation responses to levcromakalim or isoprenaline, either in terms of maximal relaxation or sensitivity. Whilst having no effect on isoprenaline-induced relaxation, studied from basal tone, the ATP-sensitive K+ channel blocker BRL 31660 (10, 30 and 50 microM) reduced relaxation responses induced (from basal tone) by levcromakalim from 74 +/- 6% (of the maximal response to isoprenaline) to 48 +/- 12% (n = 7), 9 +/- 9% (n = 4) and 0 (n = 4), respectively. Charybdotoxin, a blocker of high conductance Ca(2+)-activated K+ channels, at concentrations of 30 and 100 nM, had no effect on either levcromakalim- or or isoprenaline-induced relaxation responses and yet charybdotoxin was active at KCa channels in outside-out patches of hippocampal granule cells. Moreover, tetraethylammonium (10 mM) inhibited neither isoprenaline- nor levcromakalim-induced relaxation. This study has demonstrated that the relaxation responses elicited in human bronchus to isoprenaline and levcromakalim are likely to be the result of direct effects on the smooth muscle with no contribution from epithelial receptors or K+ channels. The actions of levcromakalim appear to be mediated only via activation of KATP channels. Further, we have made the important observation that, under the experimental conditions of our study, isoprenaline does not activate the KCa channel to produce relaxation in human bronchus.

Attenuation of Cigarette Smoke-Induced Airway Mucus Production by Hydrogen-Rich Saline in Rats

PubMed Central

Zhang, Jingxi; Dong, Yuchao; Xu, Wujian; Li, Qiang

2013-01-01

Background Over-production of mucus is an important pathophysiological feature in chronic airway disease such as chronic obstructive pulmonary disease (COPD) and asthma. Cigarette smoking (CS) is the leading cause of COPD. Oxidative stress plays a key role in CS-induced airway abnormal mucus production. Hydrogen protected cells and tissues against oxidative damage by scavenging hydroxyl radicals. In the present study we investigated the effect of hydrogen on CS-induced mucus production in rats. Methods Male Sprague-Dawley rats were divided into four groups: sham control, CS group, hydrogen-rich saline pretreatment group and hydrogen-rich saline control group. Lung morphology and tissue biochemical changes were determined by immunohistochemistry, Alcian Blue/periodic acid-Schiff staining, TUNEL, western blot and realtime RT-PCR. Results Hydrogen-rich saline pretreatment attenuated CS-induced mucus accumulation in the bronchiolar lumen, goblet cell hyperplasia, muc5ac over-expression and abnormal cell apoptosis in the airway epithelium as well as malondialdehyde increase in the BALF. The phosphorylation of EGFR at Tyr1068 and Nrf2 up-regulation expression in the rat lungs challenged by CS exposure were also abrogated by hydrogen-rich saline. Conclusion Hydrogen-rich saline pretreatment ameliorated CS-induced airway mucus production and airway epithelium damage in rats. The protective role of hydrogen on CS-exposed rat lungs was achieved at least partly by its free radical scavenging ability. This is the first report to demonstrate that intraperitoneal administration of hydrogen-rich saline protected rat airways against CS damage and it could be promising in treating abnormal airway mucus production in COPD. PMID:24376700

Emerging concepts in smooth muscle contributions to airway structure and function: implications for health and disease

PubMed Central

2016-01-01

Airway structure and function are key aspects of normal lung development, growth, and aging, as well as of lung responses to the environment and the pathophysiology of important diseases such as asthma, chronic obstructive pulmonary disease, and fibrosis. In this regard, the contributions of airway smooth muscle (ASM) are both functional, in the context of airway contractility and relaxation, as well as synthetic, involving production and modulation of extracellular components, modulation of the local immune environment, cellular contribution to airway structure, and, finally, interactions with other airway cell types such as epithelium, fibroblasts, and nerves. These ASM contributions are now found to be critical in airway hyperresponsiveness and remodeling that occur in lung diseases. This review emphasizes established and recent discoveries that underline the central role of ASM and sets the stage for future research toward understanding how ASM plays a central role by being both upstream and downstream in the many interactive processes that determine airway structure and function in health and disease. PMID:27742732

Repair of tracheal epithelium by basal cells after chlorine-induced injury

PubMed Central

2012-01-01

Background Chlorine is a widely used toxic compound that is considered a chemical threat agent. Chlorine inhalation injures airway epithelial cells, leading to pulmonary abnormalities. Efficient repair of injured epithelium is necessary to restore normal lung structure and function. The objective of the current study was to characterize repair of the tracheal epithelium after acute chlorine injury. Methods C57BL/6 mice were exposed to chlorine and injected with 5-ethynyl-2′-deoxyuridine (EdU) to label proliferating cells prior to sacrifice and collection of tracheas on days 2, 4, 7, and 10 after exposure. Airway repair and restoration of a differentiated epithelium were examined by co-localization of EdU labeling with markers for the three major tracheal epithelial cell types [keratin 5 (K5) and keratin 14 (K14) for basal cells, Clara cell secretory protein (CCSP) for Clara cells, and acetylated tubulin (AcTub) for ciliated cells]. Morphometric analysis was used to measure proliferation and restoration of a pseudostratified epithelium. Results Epithelial repair was fastest and most extensive in proximal trachea compared with middle and distal trachea. In unexposed mice, cell proliferation was minimal, all basal cells expressed K5, and K14-expressing basal cells were absent from most sections. Chlorine exposure resulted in the sloughing of Clara and ciliated cells from the tracheal epithelium. Two to four days after chlorine exposure, cell proliferation occurred in K5- and K14-expressing basal cells, and the number of K14 cells was dramatically increased. In the period of peak cell proliferation, few if any ciliated or Clara cells were detected in repairing trachea. Expression of ciliated and Clara cell markers was detected at later times (days 7–10), but cell proliferation was not detected in areas in which these differentiated markers were re-expressed. Fibrotic lesions were observed at days 7–10 primarily in distal trachea. Conclusion The data are

Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells.

PubMed Central

Kelley, T J; Drumm, M L

1998-01-01

It has been reported that exhaled nitric oxide levels are reduced in cystic fibrosis (CF) patients. We have examined the inducible isoform of nitric oxide synthase (iNOS) in the airways by immunostaining and found that iNOS is constitutively expressed in the airway epithelia of non-CF mouse and human tissues but essentially absent in the epithelium of CF airways. We explored potential consequences of lost iNOS expression and found that iNOS inhibition significantly increases mouse nasal trans-epithelial potential difference, and hindered the ability of excised mouse lungs to prevent growth of Pseudomonas aeruginosa. The absence of continuous nitric oxide production in epithelial cells of CF airways may play a role in two CF-associated characteristics: hyperabsorption of sodium and susceptibility to bacterial infections. PMID:9739054

Culturing of respiratory viruses in well-differentiated pseudostratified human airway epithelium as a tool to detect unknown viruses

PubMed Central

Jazaeri Farsani, Seyed Mohammad; Deijs, Martin; Dijkman, Ronald; Molenkamp, Richard; Jeeninga, Rienk E; Ieven, Margareta; Goossens, Herman; van der Hoek, Lia

2015-01-01

Background Currently, virus discovery is mainly based on molecular techniques. Here, we propose a method that relies on virus culturing combined with state-of-the-art sequencing techniques. The most natural ex vivo culture system was used to enable replication of respiratory viruses. Method Three respiratory clinical samples were tested on well-differentiated pseudostratified tracheobronchial human airway epithelial (HAE) cultures grown at an air–liquid interface, which resemble the airway epithelium. Cells were stained with convalescent serum of the patients to identify infected cells and apical washes were analyzed by VIDISCA-454, a next-generation sequencing virus discovery technique. Results Infected cells were observed for all three samples. Sequencing subsequently indicated that the cells were infected by either human coronavirus OC43, influenzavirus B, or influenzavirus A. The sequence reads covered a large part of the genome (52%, 82%, and 57%, respectively). Conclusion We present here a new method for virus discovery that requires a virus culture on primary cells and an antibody detection. The virus in the harvest can be used to characterize the viral genome sequence and cell tropism, but also provides progeny virus to initiate experiments to fulfill the Koch's postulates. PMID:25482367

Migration of guinea pig airway epithelial cells in response to bombesin analogues.

PubMed

Kim, J S; McKinnis, V S; White, S R

1997-03-01

Bombesin-like peptides within neuroepithelial cells elicit proliferation of normal and malignant airway epithelial cells. It is not clear that these peptides also elicit epithelial cell migration, a necessary component of airway repair after injury. We studied the effects of the bombesin analogues, gastrin releasing peptide (GRP) and neuromedin B (NMB), on guinea pig tracheal epithelial cell (GPTEC) migration. Primary GPTEC were allowed to migrate through 8-microm-pore gelatin-coated filters for 6 h in a chemotaxis chamber, after which the number of migrated cells per 10 high power fields (10 hpf) were counted. Both neuropeptides elicited migration of GPTEC: 24.8 +/- 4.5 cells for 10(-11) M NMB (P < 0.001 versus control, n = 4) and 16.8 +/- 1.2 cells for 10(-12) M GRP (P < 0.001 versus control, n = 8). Migration was attenuated substantially by a bombesin receptor antagonist. To investigate further the relationship of migration through a filter to the repair of a damaged epithelium, we studied the repair of epithelial cells by video microscopy. A 0.3- to 0.5-microm2 wound was created in a confluent monolayer of GPTEC, and wound closure was followed over 24 h. There was no significant acceleration in the rate of repair of GRP- or NMB-stimulated monolayers compared to control. These data demonstrate that GRP and NMB elicit migration of airway epithelial cells but may not play a significant role in the early repair of the airway epithelium in culture.

Integrin Beta 1 Suppresses Multilayering of a Simple Epithelium

PubMed Central

Chen, Jichao; Krasnow, Mark A.

2012-01-01

Epithelia are classified as either simple, a single cell layer thick, or stratified (multilayered). Stratified epithelia arise from simple epithelia during development, and transcription factor p63 functions as a key positive regulator of epidermal stratification. Here we show that deletion of integrin beta 1 (Itgb1) in the developing mouse airway epithelium abrogates airway branching and converts this monolayer epithelium into a multilayer epithelium with more than 10 extra layers. Mutant lung epithelial cells change mitotic spindle orientation to seed outer layers, and cells in different layers become molecularly and functionally distinct, hallmarks of normal stratification. However, mutant lung epithelial cells do not activate p63 and do not switch to the stratified keratin profile of epidermal cells. These data, together with previous data implicating Itgb1 in regulation of epidermal stratification, suggest that the simple-versus-stratified developmental decision may involve not only stratification inducers like p63 but suppressors like Itgb1 that prevent simple epithelia from inappropriately activating key steps in the stratification program. PMID:23285215

A Dynamic Bronchial Airway Gene Expression Signature of Chronic Obstructive Pulmonary Disease and Lung Function Impairment

PubMed Central

Steiling, Katrina; van den Berge, Maarten; Hijazi, Kahkeshan; Florido, Roberta; Campbell, Joshua; Liu, Gang; Xiao, Ji; Zhang, Xiaohui; Duclos, Grant; Drizik, Eduard; Si, Huiqing; Perdomo, Catalina; Dumont, Charles; Coxson, Harvey O.; Alekseyev, Yuriy O.; Sin, Don; Pare, Peter; Hogg, James C.; McWilliams, Annette; Hiemstra, Pieter S.; Sterk, Peter J.; Timens, Wim; Chang, Jeffrey T.; Sebastiani, Paola; O’Connor, George T.; Bild, Andrea H.; Postma, Dirkje S.; Lam, Stephen

2013-01-01

Rationale: Molecular phenotyping of chronic obstructive pulmonary disease (COPD) has been impeded in part by the difficulty in obtaining lung tissue samples from individuals with impaired lung function. Objectives: We sought to determine whether COPD-associated processes are reflected in gene expression profiles of bronchial airway epithelial cells obtained by bronchoscopy. Methods: Gene expression profiling of bronchial brushings obtained from 238 current and former smokers with and without COPD was performed using Affymetrix Human Gene 1.0 ST Arrays. Measurements and Main Results: We identified 98 genes whose expression levels were associated with COPD status, FEV1% predicted, and FEV1/FVC. In silico analysis identified activating transcription factor 4 (ATF4) as a potential transcriptional regulator of genes with COPD-associated airway expression, and ATF4 overexpression in airway epithelial cells in vitro recapitulates COPD-associated gene expression changes. Genes with COPD-associated expression in the bronchial airway epithelium had similarly altered expression profiles in prior studies performed on small-airway epithelium and lung parenchyma, suggesting that transcriptomic alterations in the bronchial airway epithelium reflect molecular events found at more distal sites of disease activity. Many of the airway COPD-associated gene expression changes revert toward baseline after therapy with the inhaled corticosteroid fluticasone in independent cohorts. Conclusions: Our findings demonstrate a molecular field of injury throughout the bronchial airway of active and former smokers with COPD that may be driven in part by ATF4 and is modifiable with therapy. Bronchial airway epithelium may ultimately serve as a relatively accessible tissue in which to measure biomarkers of disease activity for guiding clinical management of COPD. PMID:23471465

Trefoil factor-2 reverses airway remodeling changes in allergic airways disease.

PubMed

Royce, Simon G; Lim, Clarice; Muljadi, Ruth C; Samuel, Chrishan S; Ververis, Katherine; Karagiannis, Tom C; Giraud, Andrew S; Tang, Mimi L K

2013-01-01

Trefoil factor 2 (TFF2) is a small peptide with an important role in mucosal repair. TFF2 is up-regulated in asthma, suggesting a role in asthma pathogenesis. Given its known biological role in promoting epithelial repair, TFF2 might be expected to exert a protective function in limiting the progression of airway remodeling in asthma. The contribution of TFF2 to airway remodeling in asthma was investigated by examining the expression of TFF2 in the airway and lung, and evaluating the effects of recombinant TFF2 treatment on established airway remodeling in a murine model of chronic allergic airways disease (AAD). BALB/c mice were sensitized and challenged with ovalbumin (OVA) or saline for 9 weeks, whereas mice with established OVA-induced AAD were treated with TFF2 or vehicle control (intranasally for 14 d). Effects on airway remodeling, airway inflammation, and airway hyperresponsiveness were then assessed, whereas TFF2 expression was determined by immunohistochemistry. TFF2 expression was significantly increased in the airways of mice with AAD, compared with expression levels in control mice. TFF2 treatment resulted in reduced epithelial thickening, subepithelial collagen deposition, goblet-cell metaplasia, bronchial epithelium apoptosis, and airway hyperresponsiveness (all P < 0.05, versus vehicle control), but TFF2 treatment did not influence airway inflammation. The increased expression of endogenous TFF2 in response to chronic allergic inflammation is insufficient to prevent the progression of airway inflammation and remodeling in a murine model of chronic AAD. However, exogenous TFF2 treatment is effective in reversing aspects of established airway remodeling. TFF2 has potential as a novel treatment for airway remodeling in asthma.

A novel bronchial ring bioassay for the evaluation of small airway smooth muscle function in mice.

PubMed

Liu, John Q; Yang, Dennis; Folz, Rodney J

2006-08-01

Advances in our understanding of murine airway physiology have been hindered by the lack of suitable, ex vivo, small airway bioassay systems. In this study, we introduce a novel small murine airway bioassay system that permits the physiological and pharmacological study of intrapulmonary bronchial smooth muscle via a bronchial ring (BR) preparation utilizing BR segments as small as 200 microm in diameter. Using this ex vivo BR bioassay, we characterized small airway smooth muscle contraction and relaxation in the presence and absence of bronchial epithelium. In control BRs, the application of mechanical stretch is followed by spontaneous bronchial smooth muscle relaxation. BRs pretreated with methacholine (MCh) partially attenuate this stretch-induced relaxation by as much as 42% compared with control. MCh elicited a dose-dependent bronchial constriction with a maximal tension (E(max)) of 8.7 +/- 0.2 mN at an EC(50) of 0.33 +/- 0.02 microM. In the presence of nifedipine, ryanodine, 2-aminoethoxydiphenyl borate, and SKF-96365, E(max) to MCh was significantly reduced. In epithelium-denuded BRs, MCh-induced contraction was significantly enhanced to 11.4 +/- 1.0 mN with an EC(50) of 0.16 +/- 0.04 microM (P < 0.01). Substance P relaxed MCh-precontracted BR by 62.1%; however, this bronchial relaxation effect was completely lost in epithelium-denuded BRs. Papaverine virtually abolished MCh-induced constriction in both epithelium-intact and epithelium-denuded bronchial smooth muscle. In conclusion, this study introduces a novel murine small airway BR bioassay that allows for the physiological study of smooth muscle airway contractile responses that may aid in our understanding of the pathophysiology of asthma.

Local small airway epithelial injury induces global smooth muscle contraction and airway constriction.

PubMed

Zhou, Jian; Alvarez-Elizondo, Martha B; Botvinick, Elliot; George, Steven C

2012-02-01

Small airway epithelial cells form a continuous sheet lining the conducting airways, which serves many functions including a physical barrier to protect the underlying tissue. In asthma, injury to epithelial cells can occur during bronchoconstriction, which may exacerbate airway hyperreactivity. To investigate the role of epithelial cell rupture in airway constriction, laser ablation was used to precisely rupture individual airway epithelial cells of small airways (<300-μm diameter) in rat lung slices (∼250-μm thick). Laser ablation of single epithelial cells using a femtosecond laser reproducibly induced airway contraction to ∼70% of the original cross-sectional area within several seconds, and the contraction lasted for up to 40 s. The airway constriction could be mimicked by mechanical rupture of a single epithelial cell using a sharp glass micropipette but not with a blunt glass pipette. These results suggest that soluble mediators released from the wounded epithelial cell induce global airway contraction. To confirm this hypothesis, the lysate of primary human small airway epithelial cells stimulated a similar airway contraction. Laser ablation of single epithelial cells triggered a single instantaneous Ca(2+) wave in the epithelium, and multiple Ca(2+) waves in smooth muscle cells, which were delayed by several seconds. Removal of extracellular Ca(2+) or decreasing intracellular Ca(2+) both blocked laser-induced airway contraction. We conclude that local epithelial cell rupture induces rapid and global airway constriction through release of soluble mediators and subsequent Ca(2+)-dependent smooth muscle shortening.

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

PubMed

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

2016-08-18

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.

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

Generation of Distal Airway Epithelium from Multipotent Human Foregut Stem Cells.

PubMed

Hannan, Nicholas R F; Sampaziotis, Fotios; Segeritz, Charis-Patricia; Hanley, Neil A; Vallier, Ludovic

2015-07-15

Collectively, lung diseases are one of the largest causes of premature death worldwide and represent a major focus in the field of regenerative medicine. Despite significant progress, only few stem cell platforms are currently available for cell-based therapy, disease modeling, and drug screening in the context of pulmonary disorders. Human foregut stem cells (hFSCs) represent an advantageous progenitor cell type that can be used to amplify large quantities of cells for regenerative medicine applications and can be derived from any human pluripotent stem cell line. Here, we further demonstrate the application of hFSCs by generating a near homogeneous population of early pulmonary endoderm cells coexpressing NKX2.1 and FOXP2. These progenitors are then able to form cells that are representative of distal airway epithelium that express NKX2.1, GATA6, and cystic fibrosis transmembrane conductance regulator (CFTR) and secrete SFTPC. This culture system can be applied to hFSCs carrying the CFTR mutation Δf508, enabling the development of an in vitro model for cystic fibrosis. This platform is compatible with drug screening and functional validations of small molecules, which can reverse the phenotype associated with CFTR mutation. This is the first demonstration that multipotent endoderm stem cells can differentiate not only into both liver and pancreatic cells but also into lung endoderm. Furthermore, our study establishes a new approach for the generation of functional lung cells that can be used for disease modeling as well as for drug screening and the study of lung development.

NEUTROPHILS PLAY A CRITICAL ROLE IN THE DEVELOPMENT OF LPS-INDUCED AIRWAY DISEASE

EPA Science Inventory

ETD-02-045 (GAVETT) GPRA # 10108

Neutrophils Play a Critical Role in the Development of LPS-Induced Airway Disease.
Jordan D. Savov, Stephen H. Gavett*, David M. Brass, Daniel L. Costa*, and David A. Schwartz

ABSTRACT
We investigated the role of neutrophils...

RSV-encoded NS2 promotes epithelial cell shedding and distal airway obstruction

PubMed Central

Liesman, Rachael M.; Buchholz, Ursula J.; Luongo, Cindy L.; Yang, Lijuan; Proia, Alan D.; DeVincenzo, John P.; Collins, Peter L.; Pickles, Raymond J.

2014-01-01

Respiratory syncytial virus (RSV) infection is the major cause of bronchiolitis in young children. The factors that contribute to the increased propensity of RSV-induced distal airway disease compared with other commonly encountered respiratory viruses remain unclear. Here, we identified the RSV-encoded nonstructural 2 (NS2) protein as a viral genetic determinant for initiating RSV-induced distal airway obstruction. Infection of human cartilaginous airway epithelium (HAE) and a hamster model of disease with recombinant respiratory viruses revealed that NS2 promotes shedding of infected epithelial cells, resulting in two consequences of virus infection. First, epithelial cell shedding accelerated the reduction of virus titers, presumably by clearing virus-infected cells from airway mucosa. Second, epithelial cells shedding into the narrow-diameter bronchiolar airway lumens resulted in rapid accumulation of detached, pleomorphic epithelial cells, leading to acute distal airway obstruction. Together, these data indicate that RSV infection of the airway epithelium, via the action of NS2, promotes epithelial cell shedding, which not only accelerates viral clearance but also contributes to acute obstruction of the distal airways. Our results identify RSV NS2 as a contributing factor for the enhanced propensity of RSV to cause severe airway disease in young children and suggest NS2 as a potential therapeutic target for reducing the severity of distal airway disease. PMID:24713657

Tachykinin receptors and the airways.

PubMed

Frossard, N; Advenier, C

1991-01-01

The tachykinins, substance P, neurokinin A and neurokinin B, belong to a structural family of peptides. In mammalian airways, substance P and neurokinin A are colocalized to afferent C-fibres. Substance P-containing fibres are close to bronchial epithelium, smooth muscle, mucus glands and blood vessels. Sensory neuropeptides may be released locally, possibly as a result of a local reflex, and produce bronchial obstruction through activation of specific receptors on these various tissues. Three types of tachykinin receptors, namely NK-1, NK-2 and NK-3 receptors, have been characterized by preferential activation by substance P, neurokinin A and neurokinin B respectively. NK-1 and NK-2 receptors were recently cloned. The determination of receptor types involved in the effects of tachykinins in the airways has been done with synthetic agonists and antagonists binding specifically to NK-1, NK-2 and NK-3 receptors. Although the existence of species differences, the conclusion that bronchial smooth muscle contraction is mainly related to activation of NK-2 receptors on bronchial smooth muscle cell has been drawn. The hypothesis of a NK-2 receptor subclassification has been proposed with NK-2A receptor subtype in the guinea-pig airways. Other effects in the airways are related to stimulation of NK-1 receptors on mucus cells, vessels, epithelium and inflammatory cells. A non-receptor-mediated mechanism is also involved in the effect of substance P on inflammatory cells and mast cells.

Airway smooth muscle in airway reactivity and remodeling: what have we learned?

PubMed Central

2013-01-01

It is now established that airway smooth muscle (ASM) has roles in determining airway structure and function, well beyond that as the major contractile element. Indeed, changes in ASM function are central to the manifestation of allergic, inflammatory, and fibrotic airway diseases in both children and adults, as well as to airway responses to local and environmental exposures. Emerging evidence points to novel signaling mechanisms within ASM cells of different species that serve to control diverse features, including 1) [Ca2+]i contractility and relaxation, 2) cell proliferation and apoptosis, 3) production and modulation of extracellular components, and 4) release of pro- vs. anti-inflammatory mediators and factors that regulate immunity as well as the function of other airway cell types, such as epithelium, fibroblasts, and nerves. These diverse effects of ASM “activity” result in modulation of bronchoconstriction vs. bronchodilation relevant to airway hyperresponsiveness, airway thickening, and fibrosis that influence compliance. This perspective highlights recent discoveries that reveal the central role of ASM in this regard and helps set the stage for future research toward understanding the pathways regulating ASM and, in turn, the influence of ASM on airway structure and function. Such exploration is key to development of novel therapeutic strategies that influence the pathophysiology of diseases such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. PMID:24142517

Local small airway epithelial injury induces global smooth muscle contraction and airway constriction

PubMed Central

Zhou, Jian; Alvarez-Elizondo, Martha B.; Botvinick, Elliot

2012-01-01

Small airway epithelial cells form a continuous sheet lining the conducting airways, which serves many functions including a physical barrier to protect the underlying tissue. In asthma, injury to epithelial cells can occur during bronchoconstriction, which may exacerbate airway hyperreactivity. To investigate the role of epithelial cell rupture in airway constriction, laser ablation was used to precisely rupture individual airway epithelial cells of small airways (<300-μm diameter) in rat lung slices (∼250-μm thick). Laser ablation of single epithelial cells using a femtosecond laser reproducibly induced airway contraction to ∼70% of the original cross-sectional area within several seconds, and the contraction lasted for up to 40 s. The airway constriction could be mimicked by mechanical rupture of a single epithelial cell using a sharp glass micropipette but not with a blunt glass pipette. These results suggest that soluble mediators released from the wounded epithelial cell induce global airway contraction. To confirm this hypothesis, the lysate of primary human small airway epithelial cells stimulated a similar airway contraction. Laser ablation of single epithelial cells triggered a single instantaneous Ca2+ wave in the epithelium, and multiple Ca2+ waves in smooth muscle cells, which were delayed by several seconds. Removal of extracellular Ca2+ or decreasing intracellular Ca2+ both blocked laser-induced airway contraction. We conclude that local epithelial cell rupture induces rapid and global airway constriction through release of soluble mediators and subsequent Ca2+-dependent smooth muscle shortening. PMID:22114176

Phenotypic and physiologic variability in nasal epithelium cultured from smokers and non-smokers exposed to secondhand tobacco smoke

EPA Science Inventory

The emergence of air-liquid interface (ALI) culturing of mammalian airway epithelium is a recent innovation for experimental modeling of airway epithelial development, function, and pathogenic mechanisms associated with infectious agent and irritant exposure. This construct provi...

Endothelial MMP14 is required for endothelial-dependent growth support of human airway basal cells

PubMed Central

Ding, Bi-Sen; Gomi, Kazunori; Rafii, Shahin; Crystal, Ronald G.; Walters, Matthew S.

2015-01-01

ABSTRACT Human airway basal cells are the stem (or progenitor) population of the airway epithelium, and play a central role in anchoring the epithelium to the basement membrane. The anatomic position of basal cells allows for potential paracrine signaling between them and the underlying non-epithelial stromal cells. In support of this, we have previously demonstrated that endothelial cells support growth of basal cells during co-culture through vascular endothelial growth factor A (VEGFA)-mediated signaling. Building on these findings, we found, by RNA sequencing analysis, that basal cells expressed multiple fibroblast growth factor (FGF) ligands (FGF2, FGF5, FGF11 and FGF13) and that only FGF2 and FGF5 were capable of functioning in a paracrine manner to activate classical FGF receptor (FGFR) signaling. Antibody-mediated blocking of FGFR1 during basal-cell–endothelial-cell co-culture significantly reduced the endothelial-cell-dependent basal cell growth. Stimulation of endothelial cells with basal-cell-derived growth factors induced endothelial cell expression of matrix metallopeptidase 14 (MMP14), and short hairpin RNA (shRNA)-mediated knockdown of endothelial cell MMP14 significantly reduced the endothelial-cell-dependent growth of basal cells. Overall, these data characterize a new growth-factor-mediated reciprocal ‘crosstalk’ between human airway basal cells and endothelial cells that regulates proliferation of basal cells. PMID:26116571

Differential susceptibility of inbred mouse strains to chlorine-induced airway fibrosis

PubMed Central

Mo, Yiqun; Chen, Jing; Schlueter, Connie F.

2013-01-01

Chlorine is a reactive gas that is considered a chemical threat agent. Humans who develop acute lung injury from chlorine inhalation typically recover normal lung function; however, a subset can experience chronic airway disease. To examine pathological changes following chlorine-induced lung injury, mice were exposed to a single high dose of chlorine, and repair of the lung was analyzed at multiple times after exposure. In FVB/NJ mice, chlorine inhalation caused pronounced fibrosis of larger airways that developed by day 7 after exposure and was associated with airway hyperreactivity. In contrast, A/J mice had little or no airway fibrosis and had normal lung function at day 7. Unexposed FVB/NJ mice had less keratin 5 staining (basal cell marker) than A/J mice in large intrapulmonary airways where epithelial repair was poor and fibrosis developed after chlorine exposure. FVB/NJ mice had large areas devoid of epithelium on day 1 after exposure leading to fibroproliferative lesions on days 4 and 7. A/J mice had airways covered by squamous keratin 5-stained cells on day 1 that transitioned to a highly proliferative reparative epithelium by day 4 followed by the reappearance of ciliated and Clara cells by day 7. The data suggest that lack of basal cells in the large intrapulmonary airways and failure to effect epithelial repair at these sites are factors contributing to the development of airway fibrosis in FVB/NJ mice. The observed differences in susceptibility to chlorine-induced airway disease provide a model in which mechanisms and treatment of airway fibrosis can be investigated. PMID:23171502

Differential susceptibility of inbred mouse strains to chlorine-induced airway fibrosis.

PubMed

Mo, Yiqun; Chen, Jing; Schlueter, Connie F; Hoyle, Gary W

2013-01-15

Chlorine is a reactive gas that is considered a chemical threat agent. Humans who develop acute lung injury from chlorine inhalation typically recover normal lung function; however, a subset can experience chronic airway disease. To examine pathological changes following chlorine-induced lung injury, mice were exposed to a single high dose of chlorine, and repair of the lung was analyzed at multiple times after exposure. In FVB/NJ mice, chlorine inhalation caused pronounced fibrosis of larger airways that developed by day 7 after exposure and was associated with airway hyperreactivity. In contrast, A/J mice had little or no airway fibrosis and had normal lung function at day 7. Unexposed FVB/NJ mice had less keratin 5 staining (basal cell marker) than A/J mice in large intrapulmonary airways where epithelial repair was poor and fibrosis developed after chlorine exposure. FVB/NJ mice had large areas devoid of epithelium on day 1 after exposure leading to fibroproliferative lesions on days 4 and 7. A/J mice had airways covered by squamous keratin 5-stained cells on day 1 that transitioned to a highly proliferative reparative epithelium by day 4 followed by the reappearance of ciliated and Clara cells by day 7. The data suggest that lack of basal cells in the large intrapulmonary airways and failure to effect epithelial repair at these sites are factors contributing to the development of airway fibrosis in FVB/NJ mice. The observed differences in susceptibility to chlorine-induced airway disease provide a model in which mechanisms and treatment of airway fibrosis can be investigated.

EGR-1 and DUSP-1 are important negative regulators of pro-allergic responses in airway epithelium.

PubMed

Golebski, Korneliusz; van Egmond, Danielle; de Groot, Esther J; Roschmann, Kristina I L; Fokkens, Wytske J; van Drunen, Cornelis M

2015-05-01

Primary nasal epithelium of house dust mite allergic individuals is in a permanently activated inflammatory transcriptional state. To investigate whether a deregulated expression of EGR-1 and/or DUSP-1, two potential negative regulators of pro-inflammatory responses, could contribute to the activation of the inflammatory state. We silenced the expression of EGR-1 or DUSP-1 in the airway epithelial cell line NCI-H292. The cell lines were stimulated in a 24-h time course with the house dust mite allergen or poly(I:C). RNA expression profiles of cytokines were established using q-PCR and protein levels were determined in supernatants with ELISA. The shRNA-mediated gene silencing reduced expression levels of EGR-1 by 92% (p<0.0001) and of DUSP-1 by 76% (p<0.0001). Both mutant cells lines showed an increased and prolonged response to the HDM allergen. The mRNA induction of IL-6 was 4.6 fold (p=0.02) and 2.4 fold higher (p=0.01) in the EGR-1 and DUSP-1 knock-down, respectively when compared to the induced levels in the control cell line. For IL-8, the induction levels were 4.6 fold (p=0.01) and 13.0 (p=0.001) fold higher. The outcome was largely similar, yet not identical at the secreted protein levels. Furthermore, steroids were able to suppress the poly(I:C) induced cytokine levels by 70-95%. Deregulation of EGR-1 and/or DUSP-1 in nasal epithelium could be responsible for the prolonged activated transcriptional state observed in vivo in allergic disease. This could have clinical consequences as cytokine levels after the steroid treatment in EGR-1 or DUSP-1 knock-down remained higher than in the control cell line. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single-Cell RNA Sequencing of the Bronchial Epithelium in Smokers With Lung Cancer

DTIC Science & Technology

2015-07-01

AWARD NUMBER: W81XWH-14-1-0234 TITLE: Single-Cell RNA Sequencing of the Bronchial Epithelium in Smokers With Lung Cancer PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE Single-Cell RNA Sequencing of the Bronchial Epithelium in Smokers With Lung Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH...single cell RNA sequencing on airway epithelial cells obtained from smokers with and without lung cancer to identify cell-type dependent gene expression

Human airway epithelial cell cultures for modeling respiratory syncytial virus infection.

PubMed

Pickles, Raymond J

2013-01-01

Respiratory syncytial virus (RSV) is an important human respiratory pathogen with narrow species tropism. Limited availability of human pathologic specimens during early RSV-induced lung disease and ethical restrictions for RSV challenge studies in the lower airways of human volunteers has slowed our understanding of how RSV causes airway disease and greatly limited the development of therapeutic strategies for reducing RSV disease burden. Our current knowledge of RSV infection and pathology is largely based on in vitro studies using nonpolarized epithelial cell-lines grown on plastic or in vivo studies using animal models semipermissive for RSV infection. Although these models have revealed important aspects of RSV infection, replication, and associated inflammatory responses, these models do not broadly recapitulate the early interactions and potential consequences of RSV infection of the human columnar airway epithelium in vivo. In this chapter, the pro et contra of in vitro models of human columnar airway epithelium and their usefulness in respiratory virus pathogenesis and vaccine development studies will be discussed. The use of such culture models to predict characteristics of RSV infection and the correlation of these findings to the human in vivo situation will likely accelerate our understanding of RSV pathogenesis potentially identifying novel strategies for limiting the severity of RSV-associated airway disease.

Genetic modification of adeno-associated viral vector type 2 capsid enhances gene transfer efficiency in polarized human airway epithelial cells.

PubMed

White, April F; Mazur, Marina; Sorscher, Eric J; Zinn, Kurt R; Ponnazhagan, Selvarangan

2008-12-01

Cystic fibrosis (CF) is a common genetic disease characterized by defects in the expression of the CF transmembrane conductance regulator (CFTR) gene. Gene therapy offers better hope for the treatment of CF. Adeno-associated viral (AAV) vectors are capable of stable expression with low immunogenicity. Despite their potential in CF gene therapy, gene transfer efficiency by AAV is limited because of pathophysiological barriers in these patients. Although a few AAV serotypes have shown better transduction compared with the AAV2-based vectors, gene transfer efficiency in human airway epithelium has still not reached therapeutic levels. To engineer better AAV vectors for enhanced gene delivery in human airway epithelium, we developed and characterized mutant AAV vectors by genetic capsid modification, modeling the well-characterized AAV2 serotype. We genetically incorporated putative high-affinity peptide ligands to human airway epithelium on the GH loop region of AAV2 capsid protein. Six independent mutant AAV were constructed, containing peptide ligands previously reported to bind with high affinity for known and unknown receptors on human airway epithelial cells. The vectors were tested on nonairway cells and nonpolarized and polarized human airway epithelial cells for enhanced infectivity. One of the mutant vectors, with the peptide sequence THALWHT, not only showed the highest transduction in undifferentiated human airway epithelial cells but also indicated significant transduction in polarized cells. Interestingly, this modified vector was also able to infect cells independently of the heparan sulfate proteoglycan receptor. Incorporation of this ligand on other AAV serotypes, which have shown improved gene transfer efficiency in the human airway epithelium, may enhance the application of AAV vectors in CF gene therapy.

Decreased Fibronectin Production Significantly Contributes to Dysregulated Repair of Asthmatic Epithelium

PubMed Central

Kicic, Anthony; Hallstrand, Teal S.; Sutanto, Erika N.; Stevens, Paul T.; Kobor, Michael S.; Taplin, Christopher; Paré, Peter D.; Beyer, Richard P.; Stick, Stephen M.; Knight, Darryl A.

2010-01-01

Rationale: Damage to airway epithelium is followed by deposition of extracellular matrix (ECM) and migration of adjacent epithelial cells. We have shown that epithelial cells from children with asthma fail to heal a wound in vitro. Objectives: To determine whether dysregulated ECM production by the epithelium plays a role in aberrant repair in asthma. Methods: Airway epithelial cells (AEC) from children with asthma (n = 36), healthy atopic control subjects (n = 23), and healthy nonatopic control subjects (n = 53) were investigated by microarray, gene expression and silencing, transcript regulation analysis, and ability to close mechanical wounds. Measurements and Main Results: Time to repair a mechanical wound in vitro by AEC from healthy and atopic children was not significantly different and both were faster than AEC from children with asthma. Microarray analysis revealed differential expression of multiple gene sets associated with repair and remodeling in asthmatic AEC. Fibronectin (FN) was the only ECM component whose expression was significantly lower in asthmatic AEC. Expression differences were verified by quantitative polymerase chain reaction and ELISA, and reduced FN expression persisted in asthmatic cells over passage. Silencing of FN expression in nonasthmatic AEC inhibited wound repair, whereas addition of FN to asthmatic AEC restored reparative capacity. Asthmatic AEC failed to synthesize FN in response to wounding or cytokine/growth factor stimulation. Exposure to 5′, 2′deoxyazacytidine had no effect on FN expression and subsequent analysis of the FN promoter did not show evidence of DNA methylation. Conclusions: These data show that the reduced capacity of asthmatic epithelial cells to secrete FN is an important contributor to the dysregulated AEC repair observed in these cells. PMID:20110557

Brain-Derived Neurotrophic Factor in the Airways

PubMed Central

Prakash, Y.S.; Martin, Richard J.

2014-01-01

In addition to their well-known roles in the nervous system, there is increasing recognition that neurotrophins such as brain derived neurotrophic factor (BDNF) as well as their receptors are expressed in peripheral tissues including the lung, and can thus potentially contribute to both normal physiology and pathophysiology of several diseases. The relevance of this family of growth factors lies in emerging clinical data indicating altered neurotrophin levels and function in a range of diseases including neonatal and adult asthma, sinusitis, influenza, and lung cancer. The current review focuses on 1) the importance of BDNF expression and signaling mechanisms in early airway and lung development, critical to both normal neonatal lung function and also its disruption in prematurity and insults such as inflammation and infection; 2) how BDNF, potentially derived from airway nerves modulate neurogenic control of airway tone, a key aspect of airway reflexes as well as dysfunctional responses to allergic inflammation; 3) the emerging idea that local BDNF production by resident airway cells such as epithelium and airway smooth muscle can contribute to normal airway structure and function, and to airway hyperreactivity and remodeling in diseases such as asthma. Furthermore, given its pleiotropic effects in the airway, BDNF may be a novel and appealing therapeutic target. PMID:24560686

Airway surface liquid homeostasis in cystic fibrosis: pathophysiology and therapeutic targets.

PubMed

Haq, Iram J; Gray, Michael A; Garnett, James P; Ward, Christopher; Brodlie, Malcolm

2016-03-01

Cystic fibrosis (CF) is a life-limiting disease characterised by recurrent respiratory infections, inflammation and lung damage. The volume and composition of the airway surface liquid (ASL) are important in maintaining ciliary function, mucociliary clearance and antimicrobial properties of the airway. In CF, these homeostatic mechanisms are impaired, leading to a dehydrated and acidic ASL. ASL volume depletion in CF is secondary to defective anion transport by the abnormal cystic fibrosis transmembrane conductance regulator protein (CFTR). Abnormal CFTR mediated bicarbonate transport creates an unfavourable, acidic environment, which impairs antimicrobial function and alters mucus properties and clearance. These disease mechanisms create a disordered airway milieu, consisting of thick mucopurulent secretions and chronic bacterial infection. In addition to CFTR, there are additional ion channels and transporters in the apical airway epithelium that play a role in maintaining ASL homeostasis. These include the epithelial sodium channel (ENaC), the solute carrier 26A (SLC26A) family of anion exchangers, and calcium-activated chloride channels. In this review we discuss how the ASL is abnormal in CF and how targeting these alternative channels and transporters could provide an attractive therapeutic strategy to correct the underlying ASL abnormalities evident in CF. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Prostaglandin I2 promotes the development of IL-17-producing γδ T cells that associate with the epithelium during allergic lung inflammation

PubMed Central

Jaffar, Zeina; Ferrini, Maria E.; Shaw, Pamela K.; FitzGerald, Garret A.; Roberts, Kevan

2011-01-01

γδ T cells rapidly produce cytokines and represent a first line of defence against microbes and other environmental insults at mucosal tissues and are thus thought to play a local immunoregulatory role. We show that allergic airway inflammation was associated with an increase in innate IL-17-producing γδ T (γδ-17) cells that expressed the αEβ7 integrin and were closely associated with the airway epithelium. Importantly, prostaglandin (PG)I2 and its receptor IP, which downregulated airway eosinophilic inflammation, promoted the emergence of these intraepithelial γδ-17 cells into the airways by enhancing IL-6 production by lung eosinophils and dendritic cells. Accordingly, a pronounced reduction of γδ-17 cells was observed in the thymus of naïve mice lacking the PGI2 receptor IP, as well as in the lungs during allergic inflammation, implying a critical role for PGI2 in the programming of “natural” γδ-17 cells. Conversely, iloprost, a stable analog of PGI2, augmented IL-17 production by γδ T cells but significantly reduced the airway inflammation. Together, these findings suggest that PGI2 plays a key immunoregulatory role by promoting the development of innate intraepithelial γδ-17 cells through an IL-6-dependent mechanism. By enhancing γδ-17 cell responses, stable analogs of PGI2 may be exploited in the development of new immunotherapeutic approaches. PMID:21976777

Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

PubMed

Ugonna, Kelechi; Bingle, Colin D; Plant, Karen; Wilson, Kirsty; Everard, Mark L

2014-01-01

We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

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.

Endogenous gamma-aminobutyric acid modulates tonic guinea pig airway tone and propofol-induced airway smooth muscle relaxation.

PubMed

Gallos, George; Gleason, Neil R; Virag, Laszlo; Zhang, Yi; Mizuta, Kentaro; Whittington, Robert A; Emala, Charles W

2009-04-01

Emerging evidence indicates that an endogenous autocrine/paracrine system involving gamma-aminobutyric acid (GABA) is present in airways. GABAA channels, GABAB receptors, and the enzyme that synthesizes GABA have been identified in airway epithelium and smooth muscle. However, the endogenous ligand itself, GABA, has not been measured in airway tissues. The authors sought to demonstrate that GABA is released in response to contractile agonists and tonically contributes a prorelaxant component to contracted airway smooth muscle. The amount and cellular localization of GABA in upper guinea pig airways under resting and contracted tone was determined by high pressure liquid chromatography and immunohistochemistry, respectively. The contribution that endogenous GABA imparts on the maintenance of airway smooth muscle acetylcholine-induced contraction was assessed in intact guinea pig airway tracheal rings using selective GABAA antagonism (gabazine) under resting or acetylcholine-contracted conditions. The ability of an allosteric agent (propofol) to relax a substance P-induced relaxation in an endogenous GABA-dependent manner was assessed. GABA levels increased and localized to airway smooth muscle after contractile stimuli in guinea pig upper airways. Acetylcholine-contracted guinea pig tracheal rings exhibited an increase in contracted force upon addition of the GABAA antagonist gabazine that was subsequently reversed by the addition of the GABAA agonist muscimol. Propofol dose-dependently relaxed a substance P contraction that was blocked by gabazine. These studies demonstrate that GABA is endogenously present and increases after contractile stimuli in guinea pig upper airways and that endogenous GABA contributes a tonic prorelaxant component in the maintenance of airway smooth muscle tone.

Endogenous γ-aminobutyric Acid Modulates Tonic Guinea Pig Airway Tone and Propofol-induced Airway Smooth Muscle Relaxation

PubMed Central

Gallos, George; Gleason, Neil R.; Virag, Laszlo; Zhang, Yi; Mizuta, Kentauro; Whittington, Robert A.; Emala, Charles W.

2009-01-01

Background Emerging evidence indicates that an endogenous autocrine/paracrine system involving γ-aminobutyric acid (GABA) is present in airways. GABAA channels, GABAB receptors and the enzyme that synthesizes GABA have been identified in airway epithelium and smooth muscle. However, the endogenous ligand itself, GABA, has not been measured in airway tissues. We sought to demonstrate that GABA is released in response to contractile agonists and tonically contributes a pro-relaxant component to contracted airway smooth muscle. Methods The amount and cellular localization of GABA in upper guinea pig airways under resting and contracted tone was determined by high pressure liquid chromatography and immunohistochemistry, respectively. The contribution that endogenous GABA imparts on the maintenance of airway smooth muscle acetylcholine-induced contraction was assessed in intact guinea pig airway tracheal rings using selective GABAA antagonism (gabazine) under resting or acetylcholine-contracted conditions. The ability of an allosteric agent (propofol) to relax a substance P-induced relaxation in an endogenous GABA-dependent manner was assessed. Results GABA levels increased and localized to airway smooth muscle following contractile stimuli in guinea pig upper airways. Acetylcholine-contracted guinea pig tracheal rings exhibited an increase in contracted force upon addition of the GABAA antagonist gabazine which was subsequently reversed by the addition of the GABAA agonist muscimol. Propofol dose-dependently relaxed a substance P contraction that was blocked by gabazine. Conclusion These studies demonstrate that GABA is endogenously present and increases following contractile stimuli in guinea pig upper airways and that endogenous GABA contributes a tonic pro-relaxant component in the maintenance of airway smooth muscle tone. PMID:19322939

Early growth response gene 1 is essential for urban particulate matter-induced inflammation and mucus hyperproduction in airway epithelium.

PubMed

Xu, Feng; Cao, Jiaofei; Luo, Man; Che, Luanqing; Li, Wen; Ying, Songmin; Chen, Zhihua; Shen, Huahao

2018-05-19

Particulate matter (PM) has been implicated as a risk factor for human airway disorders. However, the biological mechanisms underlying the correlation between PM exposure and adverse airway effects have not yet been fully clarified. The objective of this study was to explore the possible role of early growth response gene 1 (Egr-1) in PM-induced toxic effects in pulmonary inflammation and mucus hyperproduction in vitro and in vivo. Particulate matter exposure induced a rapid Egr-1 expression in human bronchial epithelial (HBE) cells and in mouse lungs. Genetic blockage of Egr-1 markedly reduced PM-induced inflammatory cytokines, e.g., IL6 and IL8, and MUC5AC in HBE cells, and these effects were mechanistically mediated by the nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) pathways, respectively. Egr-1-knockout mice displayed significantly reduced airway inflammation and mucus hyperproduction in response to PM exposure in vivo. Moreover, polycyclic aromatic hydrocarbons (PAHs) contained in the PM also induced Egr-1 expression, and also played a role in the inflammatory responses and mucus production. Taken together, our data reveal novel Egr-1 signaling that mediates the NF-κB and AP-1 pathways to orchestrate PM-induced pulmonary inflammation and mucus hyperproduction, suggesting that Egr-1 inhibition could be an effective therapeutic approach for airway disorders or disease exacerbations induced by airborne particulate pollution. Copyright © 2018. Published by Elsevier B.V.

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...

Inhibition of CD23-mediated IgE transcytosis suppresses the initiation and development of airway allergic inflammation

USDA-ARS?s Scientific Manuscript database

The epithelium lining the airway tract and allergen-specific IgE are considered essential controllers of inflammatory responses to allergens. The human IgE receptor, CD23 (Fc'RII), is capable of transporting IgE or IgE-allergen complexes across the polarized human airway epithelial cell (AEC) monola...

High Degree of Overlap between Responses to a Virus and to the House Dust Mite Allergen in Airway Epithelial Cells

PubMed Central

Golebski, Korneliusz; Luiten, Silvia; van Egmond, Danielle; de Groot, Esther; Röschmann, Kristina Irene Lisolette; Fokkens, Wytske Johanna; van Drunen, Cornelis Maria

2014-01-01

Background Airway epithelium is widely considered to play an active role in immune responses through its ability to detect changes in the environment and to generate a microenvironment for immune competent cells. Therefore, besides its role as a physical barrier, epithelium affects the outcome of the immune response by the production of various pro-inflammatory mediators. Methods We stimulated airway epithelial cells with viral double stranded RNA analogue poly(I:C) or with house dust mite in a time course of 24 hours. In order to determine cytokines production by stimulated cells, we performed multiplex enzyme linked immunosorbant assay (ELISA). Results We demonstrate that the temporal pattern of the genes that respond to virus exposure in airway epithelium resembles to a significant degree their pattern of response to HDM. The gene expression pattern of EGR1, DUSP1, FOSL1, JUN, MYC, and IL6 is rather similar after viral (poly(I:C)) and HDM exposure. However, both triggers also induce a specific response (e.g. ATF3, FOS, and NFKB1). We confirmed these data by showing that epithelial cells produce a variety of similar mediators in response to both poly(I:C) and HDM challenge (IL1-RA, IL-17, IFN-α and MIP1-α), sometimes with a quantitative difference in response (IL2-R, IL-6, IL-8, MCP-1, MIG, and HGF). Interestingly, only four mediators (IL-12, IP-10, RANTES and VEGF) where up-regulated specifically by poly(I:C) and not by HDM. Additionally, we report that pre-exposure to HDM deregulates production of cytokines and mediators in response to poly(I:C). Conclusions Epithelial cells responses to the HDM-allergen and a virus strongly resemble both in gene expression and in protein level explaining why these two responses may affect each other. PMID:24498371

High degree of overlap between responses to a virus and to the house dust mite allergen in airway epithelial cells.

PubMed

Golebski, Korneliusz; Luiten, Silvia; van Egmond, Danielle; de Groot, Esther; Röschmann, Kristina Irene Lisolette; Fokkens, Wytske Johanna; van Drunen, Cornelis Maria

2014-01-01

Airway epithelium is widely considered to play an active role in immune responses through its ability to detect changes in the environment and to generate a microenvironment for immune competent cells. Therefore, besides its role as a physical barrier, epithelium affects the outcome of the immune response by the production of various pro-inflammatory mediators. We stimulated airway epithelial cells with viral double stranded RNA analogue poly(I:C) or with house dust mite in a time course of 24 hours. In order to determine cytokines production by stimulated cells, we performed multiplex enzyme linked immunosorbant assay (ELISA). We demonstrate that the temporal pattern of the genes that respond to virus exposure in airway epithelium resembles to a significant degree their pattern of response to HDM. The gene expression pattern of EGR1, DUSP1, FOSL1, JUN, MYC, and IL6 is rather similar after viral (poly(I:C)) and HDM exposure. However, both triggers also induce a specific response (e.g. ATF3, FOS, and NFKB1). We confirmed these data by showing that epithelial cells produce a variety of similar mediators in response to both poly(I:C) and HDM challenge (IL1-RA, IL-17, IFN-α and MIP1-α), sometimes with a quantitative difference in response (IL2-R, IL-6, IL-8, MCP-1, MIG, and HGF). Interestingly, only four mediators (IL-12, IP-10, RANTES and VEGF) where up-regulated specifically by poly(I:C) and not by HDM. Additionally, we report that pre-exposure to HDM deregulates production of cytokines and mediators in response to poly(I:C). Epithelial cells responses to the HDM-allergen and a virus strongly resemble both in gene expression and in protein level explaining why these two responses may affect each other.

EP2 receptors mediate airway relaxation to substance P, ATP, and PGE2.

PubMed

Fortner, C N; Breyer, R M; Paul, R J

2001-08-01

Substance P (SP) and ATP evoke transient, epithelium-dependent relaxation of constricted mouse tracheal smooth muscle. Relaxation to either SP or ATP is blocked by indomethacin, but the specific eicosanoid(s) involved have not been definitively identified. SP and ATP are reported to release PGE2 from airway epithelium in other species, suggesting PGE2 as a likely mediator in epithelium-dependent airway relaxation. Using mice homozygous for a gene-targeted deletion of the EP2 receptor [EP2(-/-)], one of the PGE2 receptors, we tested the hypothesis that PGE2 is the primary mediator of relaxation to SP or ATP. Relaxation in response to SP or ATP was significantly reduced in tracheas from EP2(-/-) mice. There were no differences between EP2(-/-) and wild-type tracheas in their physical dimensions, contraction to ACh, or relaxation to isoproterenol, thus ruling out any general alterations of smooth muscle function. There were also no differences between EP2(-/-) and wild-type tracheas in basal or stimulated PGE2 production. Exogenous PGE2 produced significantly less relaxation in EP2(-/-) tracheas compared with the wild type. Taken together, this experimental evidence supports the following two conclusions: EP2 receptors are of primary importance in airway relaxation to PGE2 and relaxation to SP or ATP is mediated through PGE2 acting on EP2 receptors.

FAMM Flap in Reconstructing Postsurgical Nasopharyngeal Airway Stenosis

PubMed Central

Nangole, Ferdinand Wanjala; Khainga, Stanley Ominde

2014-01-01

Introduction. Postsurgical nasopharyngeal airway stenosis can be a challenge to manage. The stenosis could be as a result of any surgical procedure in the nasopharyngeal region that heals extensive scarring and fibrosis. Objective. To evaluate patients with nasopharyngeal stenosis managed with FAMM flap. Study Design. Prospective study of patients with nasopharyngeal stenosis at the Kenyatta National Hospital between 2010 and 2013 managed with FAMM flap. Materials and Methods. Patients with severe nasopharyngeal airway stenosis were reviewed and managed with FAMM flaps at the Kenyatta National Hospital. Postoperatively they were assessed for symptomatic improvement in respiratory distress, patency of the nasopharyngeal airway, and donor site morbidity. Results. A total of 8 patients were managed by the authors in a duration of 4 years with nasopharyngeal stenosis. Five patients were managed with unilateral FAMM flaps in a two-staged surgical procedure. Four patients had complete relieve of the airway obstruction with a patent airway created. One patient had a patent airway created though with only mild improvement in airway obstruction. Conclusion. FAMM flap provides an alternative in the management of postsurgical severe nasopharyngeal stenosis. It is a reliable flap that is easy to raise and could provide adequate epithelium for the stenosed pharynx. PMID:25328699

Differential antiviral activities of respiratory syncytial virus (RSV) inhibitors in human airway epithelium.

PubMed

Mirabelli, Carmen; Jaspers, Martine; Boon, Mieke; Jorissen, Mark; Koukni, Mohamed; Bardiot, Dorothée; Chaltin, Patrick; Marchand, Arnaud; Neyts, Johan; Jochmans, Dirk

2018-03-27

We report the use of reconstituted 3D human airway epithelium cells (HuAECs) of bronchial origin in an air-liquid interface to study respiratory syncytial virus (RSV) infection and to assess the efficacy of RSV inhibitors in (pre-)clinical development. HuAECs were infected with RSV-A Long strain (0.01 CCID50/cell, where CCID50 represents 50% cell culture infectious dose in HEp2 cells) on the apical compartment of the culture. At the time of infection or at 1 or 3 days post-infection, selected inhibitors were added and refreshed daily on the basal compartment of the culture. Viral shedding was followed up by apical washes collected daily and quantifying viral RNA by RT-qPCR. RSV-A replicates efficiently in HuAECs and viral RNA is shed for weeks after infection. RSV infection reduces the ciliary beat frequency of the ciliated cells as of 4 days post-infection, with complete ciliary dyskinesia observed by day 10. Treatment with RSV fusion inhibitors resulted in an antiviral effect only when added at the time of infection. In contrast, the use of replication inhibitors (both nucleoside and non-nucleoside) elicited a marked antiviral effect even when the start of treatment was delayed until 1 day or even 3 days after infection. Levels of the inflammation marker RANTES (mRNA) increased ∼200-fold in infected, untreated cultures (at 3 weeks post-infection), but levels were comparable to those of uninfected cultures in the presence of PC786, an RSV replication inhibitor, suggesting that an efficient antiviral treatment might inhibit virus-induced inflammation in this model. Overall, HuAECs offer a robust and physiologically relevant model to study RSV replication and to assess the efficacy of antiviral compounds.

Uptake and transport of B12-conjugated nanoparticles in airway epithelium☆

PubMed Central

Fowler, Robyn; Vllasaliu, Driton; Falcone, Franco H.; Garnett, Martin; Smith, Bryan; Horsley, Helen; Alexander, Cameron; Stolnik, Snow

2013-01-01

Non-invasive delivery of biotherapeutics, as an attractive alternative to injections, could potentially be achieved through the mucosal surfaces, utilizing nanoscale therapeutic carriers. However, nanoparticles do not readily cross the mucosal barriers, with the epithelium presenting a major barrier to their translocation. The transcytotic pathway of vitamin B12 has previously been shown to ‘ferry’ B12-decorated nanoparticles across intestinal epithelial (Caco-2) cells. However, such studies have not been reported for the airway epithelium. Furthermore, the presence in the airways of the cell machinery responsible for transepithelial trafficking of B12 is not widely reported. Using a combination of molecular biology and immunostaining techniques, our work demonstrates that the bronchial cell line, Calu-3, expresses the B12-intrinsic factor receptor, the transcobalamin II receptor and the transcobalamin II carrier protein. Importantly, the work showed that sub-200 nm model nanoparticles chemically conjugated to B12 were internalised and transported across the Calu-3 cell layers, with B12 conjugation not only enhancing cell uptake and transepithelial transport, but also influencing intracellular trafficking. Our work therefore demonstrates that the B12 endocytotic apparatus is not only present in this airway model, but also transports ligand-conjugated nanoparticles across polarised epithelial cells, indicating potential for B12-mediated delivery of nanoscale carriers of biotherapeutics across the airways. PMID:24008152

ORMDL3 may participate in the pathogenesis of bronchial epithelial‑mesenchymal transition in asthmatic mice with airway remodeling.

PubMed

Cheng, Qi; Shang, Yunxiao

2018-01-01

Asthma is a common chronic respiratory disease in children that is caused by a complex interaction between genetic and environmental factors. Orosomucoid‑like 3 (ORMDL3) is a candidate gene that has been strongly associated with asthma; however, the underlying mechanisms are unknown. ORMDL3 regulates the expression of metalloproteinases and transforming growth factor‑β, and ORMDL3 transgenic mice exhibit increased airway remodeling. Therefore, ORMDL3 may be associated with airway remodeling. The present study attempted to examine the associations between ORMDL3 and the severity of airway remodeling in asthmatic mice, and also to determine whether ORMDL3 induces epithelial‑mesenchymal transition (EMT) in the bronchial epithelium. For this purpose, BALB/c mice were randomly assigned to control and asthma groups. Lung tissues were collected on days 3, 7 and 14 of the ovalbumin (OVA) challenge. Airway remodeling in asthmatic mice was then observed by hematoxylin and eosin, and Masson staining. Morphological changes in the bronchial epithelium were assessed by transmission electron microscopy. The EMT‑associated indicators E‑cadherin (E‑cad), fibroblast‑specific protein 1 (FSP1) and Vimentin (VIM) were assessed by western blotting and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) at different time points of airway remodeling in asthmatic mice to detect the trend in EMT. Then, the localization of ORMDL3 was observed by immunohistochemistry, and its protein and mRNA expression was examined by western blotting and RT‑qPCR, respectively. Furthermore, the bronchial epithelial cell line 16HBE14o‑was transfected with an ORMDL3‑expressing plasmid, and the differences in E‑cad, FSP‑1 and VIM expression were detected by immunofluorescence, western blotting and RT‑qPCR; the cell invasive ability was assessed by microscopy. The results revealed that ORMDL3 expression in the bronchial epithelium was associated with airway

Mast Cells Can Amplify Airway Reactivity and Features of Chronic Inflammation in an Asthma Model in Mice

PubMed Central

Williams, Cara M.M.; Galli, Stephen J.

2000-01-01

The importance of mast cells in the development of the allergen-induced airway hyperreactivity and inflammation associated with asthma remains controversial. We found that genetically mast cell–deficient WBB6F1-W/Wv mice that were sensitized to ovalbumin (OVA) without adjuvant, then challenged repetitively with antigen intranasally, exhibited much weaker responses in terms of bronchial hyperreactivity to aerosolized methacholine, lung tissue eosinophil infiltration, and numbers of proliferating cells within the airway epithelium than did identically treated WBB6F1-+/+ normal mice. However, W/Wv mice that had undergone selective reconstitution of tissue mast cells with in vitro–derived mast cells of congenic +/+ mouse origin exhibited airway responses that were very similar to those of the +/+ mice. By contrast, W/Wv mice that were sensitized with OVA emulsified in alum and challenged with aerosolized OVA exhibited levels of airway hyperreactivity and lung tissue eosinophil infiltration that were similar to those of the corresponding +/+ mice. Nevertheless, these W/Wv mice exhibited significantly fewer proliferating cells within the airway epithelium than did identically treated +/+ mice. These results show that, depending on the “asthma model” investigated, mast cells can either have a critical role in, or not be essential for, multiple features of allergic airway responses in mice. PMID:10934234

Mechanical Forces Program the Orientation of Cell Division during Airway Tube Morphogenesis.

PubMed

Tang, Zan; Hu, Yucheng; Wang, Zheng; Jiang, Kewu; Zhan, Cheng; Marshall, Wallace F; Tang, Nan

2018-02-05

Oriented cell division plays a key role in controlling organogenesis. The mechanisms for regulating division orientation at the whole-organ level are only starting to become understood. By combining 3D time-lapse imaging, mouse genetics, and mathematical modeling, we find that global orientation of cell division is the result of a combination of two types of spindles with distinct spindle dynamic behaviors in the developing airway epithelium. Fixed spindles follow the classic long-axis rule and establish their division orientation before metaphase. In contrast, rotating spindles do not strictly follow the long-axis rule and determine their division orientation during metaphase. By using both a cell-based mechanical model and stretching-lung-explant experiments, we showed that mechanical force can function as a regulatory signal in maintaining the stable ratio between fixed spindles and rotating spindles. Our findings demonstrate that mechanical forces, cell geometry, and oriented cell division function together in a highly coordinated manner to ensure normal airway tube morphogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Acid-Sensing Ion Channel 1a Contributes to Airway Hyperreactivity in Mice

PubMed Central

Reznikov, Leah R.; Meyerholz, David K.; Adam, Ryan J.; Abou Alaiwa, Mahmoud; Jaffer, Omar; Michalski, Andrew S.; Powers, Linda S.; Price, Margaret P.; Stoltz, David A.; Welsh, Michael J.

2016-01-01

Neurons innervating the airways contribute to airway hyperreactivity (AHR), a hallmark feature of asthma. Several observations suggested that acid-sensing ion channels (ASICs), neuronal cation channels activated by protons, might contribute to AHR. For example, ASICs are found in vagal sensory neurons that innervate airways, and asthmatic airways can become acidic. Moreover, airway acidification activates ASIC currents and depolarizes neurons innervating airways. We found ASIC1a protein in vagal ganglia neurons, but not airway epithelium or smooth muscle. We induced AHR by sensitizing mice to ovalbumin and found that ASIC1a-/- mice failed to exhibit AHR despite a robust inflammatory response. Loss of ASIC1a also decreased bronchoalveolar lavage fluid levels of substance P, a sensory neuropeptide secreted from vagal sensory neurons that contributes to AHR. These findings suggest that ASIC1a is an important mediator of AHR and raise the possibility that inhibiting ASIC channels might be beneficial in asthma. PMID:27820848

Activation of MTOR in pulmonary epithelium promotes LPS-induced acute lung injury.

PubMed

Hu, Yue; Lou, Jian; Mao, Yuan-Yuan; Lai, Tian-Wen; Liu, Li-Yao; Zhu, Chen; Zhang, Chao; Liu, Juan; Li, Yu-Yan; Zhang, Fan; Li, Wen; Ying, Song-Min; Chen, Zhi-Hua; Shen, Hua-Hao

2016-12-01

MTOR (mechanistic target of rapamycin [serine/threonine kinase]) plays a crucial role in many major cellular processes including metabolism, proliferation and macroautophagy/autophagy induction, and is also implicated in a growing number of proliferative and metabolic diseases. Both MTOR and autophagy have been suggested to be involved in lung disorders, however, little is known about the role of MTOR and autophagy in pulmonary epithelium in the context of acute lung injury (ALI). In the present study, we observed that lipopolysaccharide (LPS) stimulation induced MTOR phosphorylation and decreased the expression of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β)-II, a hallmark of autophagy, in mouse lung epithelium and in human bronchial epithelial (HBE) cells. The activation of MTOR in HBE cells was mediated by TLR4 (toll-like receptor 4) signaling. Genetic knockdown of MTOR or overexpression of autophagy-related proteins significantly attenuated, whereas inhibition of autophagy further augmented, LPS-induced expression of IL6 (interleukin 6) and IL8, through NFKB signaling in HBE cells. Mice with specific knockdown of Mtor in bronchial or alveolar epithelial cells exhibited significantly attenuated airway inflammation, barrier disruption, and lung edema, and displayed prolonged survival in response to LPS exposure. Taken together, our results demonstrate that activation of MTOR in the epithelium promotes LPS-induced ALI, likely through downregulation of autophagy and the subsequent activation of NFKB. Thus, inhibition of MTOR in pulmonary epithelial cells may represent a novel therapeutic strategy for preventing ALI induced by certain bacteria.

Observing planar cell polarity in multiciliated mouse airway epithelial cells.

PubMed

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Ion transport by primary cultures of canine tracheal epithelium: methodology, morphology, and electrophysiology.

PubMed

Welsh, M J

1985-01-01

Canine tracheal epithelial cells were isolated by enzymatic and mechanical dispersion and cultured on permeable supports. The cells formed confluent monolayers and retained most of the morphologic characteristics of the intact epithelium, including apical microvilli, apical tight junctions, and a moderately interdigitated lateral intercellular space. The cells also retained the functional properties of the epithelium. The monolayer responded to addition of isoproterenol with the characteristic changes in cellular electrical properties expected for stimulation of C1 secretion: isoproterenol increased transepithelial voltage, depolarized apical membrane voltage, and decreased both transepithelial resistance and the ratio of apical-to-basolateral membrane resistance. Examination of the cellular response to ion substitutions and inhibitors of C1 secretion indicate that the cultured monolayers retain the same cellular mechanisms of ion transport as the intact epithelium. Thus, primary cultures of tracheal epithelium may provide a useful preparation for future studies of the mechanism and regulation of C1 secretion by airway epithelia.

Effects of nitrous oxide on the production of cytokines and chemokines by the airway epithelium during anesthesia with sevoflurane and propofol.

PubMed

Kumakura, Seiichiro; Yamaguchi, Keisuke; Sugasawa, Yusuke; Murakami, Taisuke; Kikuchi, Toshihiro; Inada, Eiichi; Nagaoka, Isao

2013-12-01

The aim of this study was to evaluate the effects of nitrous oxide (a gaseous anesthetic) on the in vivo production of inflammatory cytokines and chemokines by the airway epithelium, when combined with sevoflurane or propofol. Subjects undergoing simple or segmental mastectomy were randomly assigned to the sevoflurane and nitrous oxide, sevoflurane and air, propofol and nitrous oxide, or propofol and air group (all n=13). Epithelial lining fluid (ELF) was obtained using the bronchoscopic microsampling method prior to and following the mastectomy to enable measurement of the pre- and post-operative levels of certain inflammatory cytokines and chemokines using a cytometric bead array system. Notably, the levels of interleukin (IL)-1β, IL-8 and monocyte chemotactic protein-1 (MCP-1) in the ELF were significantly increased following the operations which involved the inhalation of sevoflurane and nitrous oxide, although the levels of these molecules were not significantly changed by the inhalation of sevoflurane and air. Furthermore, the IL-12p70 levels were significantly reduced in the ELF following the operations that involved the inhalation of sevoflurane and air, although the IL-12p70 levels were not significantly changed by the inhalation of nitrous oxide and sevoflurane. These observations suggest that the combination of sevoflurane and nitrous oxide induces an inflammatory response (increased production of IL-1β, IL-8 and MCP-1) and suppresses the anti-inflammatory response (reduced production of IL-12p70) in the local milieu of the airway. Thus, the combination of these compounds should be carefully administered for anesthesia.

ZMappTM Reinforces the Airway Mucosal Barrier Against Ebola Virus.

PubMed

Yang, Bing; Schaefer, Alison; Wang, Ying-Ying; McCallen, Justin; Lee, Phoebe; Newby, Jay M; Arora, Harendra; Kumar, Priya A; Zeitlin, Larry; Whaley, Kevin J; McKinley, Scott A; Fischer, William A; Harit, Dimple; Lai, Samuel K

2018-04-24

Filoviruses, including Ebola, have the potential to be transmitted via virus-laden droplets deposited onto mucus membranes. Protecting against such emerging pathogens will require understanding how they may transmit at mucosal surfaces and developing strategies to reinforce the airway mucus barrier.Here, we prepared Ebola pseudovirus (with Zaire strain glycoproteins) and employed high resolution multiple particle tracking to track the motions of hundreds of individual pseudoviruses in fresh and undiluted human airway mucus isolated from extubated endotracheal tubes.We found that Ebola pseudovirus readily penetrate human airway mucus. Addition of ZMappTM, a cocktail of Ebola-binding IgG antibodies, effectively reduced mobility of Ebola pseudovirus in the same mucus secretions. Topical delivery of ZMappTM to the mouse airways also facilitated rapid elimination of Ebola pseudovirus.Our work demonstrates that antibodies can immobilize virions in airway mucus and reduce access to the airway epithelium, highlighting topical delivery of pathogen-specific antibodies to the lungs as a potential prophylactic or therapeutic approach against emerging viruses or biowarfare agents.

Increased Expression of FoxM1 Transcription Factor in Respiratory Epithelium Inhibits Lung Sacculation and Causes Clara Cell Hyperplasia

PubMed Central

Wang, I-Ching; Zhang, Yufang; Snyder, Jonathan; Sutherland, Mardi J.; Burhans, Michael S.; Shannon, John M.; Park, Hyun Jung; Whitsett, Jeffrey A.; Kalinichenko, Vladimir V.

2010-01-01

Foxm1 is a member of the Forkhead Box (Fox) family of transcription factors. Foxm1 (previously called Foxm1b, HFH-11B, Trident, Win, or MPP2) is expressed in multiple cell types and plays important roles in cellular proliferation, differentiation and tumorigenesis. Genetic deletion of Foxm1 from mouse respiratory epithelium during initial stages of lung development inhibits lung maturation and causes respiratory failure after birth. However, the role of Foxm1 during postnatal lung morphogenesis remains unknown. In the present study, Foxm1 expression was detected in epithelial cells of conducting and peripheral airways and changing dynamically with lung maturation. To discern the biological role of Foxm1 in the prenatal and postnatal lung, a novel transgenic mouse line that expresses a constitutively active form of FoxM1 (FoxM1 N-terminal deletion mutant or FoxM1-ΔN) under the control of lung epithelial-specific SPC promoter was produced. Expression of the FoxM1-ΔN transgene during embryogenesis caused epithelial hyperplasia, inhibited lung sacculation and expression of the type II epithelial marker, pro-SPC. Expression of FoxM1-ΔN mutant during the postnatal period did not influence alveologenesis but caused focal airway hyperplasia and increased proliferation of Clara cells. Likewise, expression of FoxM1-ΔN mutant in conducting airways with Scgb1a1 promoter was sufficient to induce Clara cell hyperplasia. Furthermore, FoxM1-ΔN cooperated with activated K-Ras to induce lung tumor growth in vivo. Increased activity of Foxm1 altered lung sacculation, induced proliferation in the respiratory epithelium and accelerated lung tumor growth, indicating that precise regulation of Foxm1 is critical for normal lung morphogenesis and development of lung cancer. PMID:20816795

Myb permits multilineage airway epithelial cell differentiation

PubMed Central

Pan, Jie-hong; Adair-Kirk, Tracy L.; Patel, Anand C.; Huang, Tao; Yozamp, Nicholas S.; Xu, Jian; Reddy, E. Premkumar; Byers, Derek E.; Pierce, Richard A.; Holtzman, Michael J.; Brody, Steven L.

2014-01-01

The epithelium of the pulmonary airway is specially differentiated to provide defense against environmental insults, but also subject to dysregulated differentiation that results in lung disease. The current paradigm for airway epithelial differentiation is a one-step program whereby a p63+ basal epithelial progenitor cell generates a ciliated or secretory cell lineage, but the cue for this transition and whether there are intermediate steps is poorly defined. Here we identify transcription factor Myb as a key regulator that permits early multilineage differentiation of airway epithelial cells. Myb+ cells were identified as p63− and therefore distinct from basal progenitor cells, but were still negative for markers of differentiation. Myb RNAi treatment of primary-culture airway epithelial cells and Myb gene deletion in mice resulted in a p63− population with failed maturation of Foxj1+ ciliated cells, as well as Scbg1a1+ and Muc5ac+ secretory cells. Consistent with these findings, analysis of whole genome expression of Myb-deficient cells identified Myb-dependent programs for ciliated and secretory cell differentiation. Myb+ cells were rare in human airways but were increased in regions of ciliated cells and mucous cell hyperplasia in samples from subjects with chronic obstructive pulmonary disease. Together, the results show that a p63− Myb+ population of airway epithelial cells represents a distinct intermediate stage of differentiation that is required under normal conditions and may be heightened in airway disease. PMID:25103188

Human Lung Small Airway-on-a-Chip Protocol.

PubMed

Benam, Kambez H; Mazur, Marc; Choe, Youngjae; Ferrante, Thomas C; Novak, Richard; Ingber, Donald E

2017-01-01

Organs-on-chips are microfluidic cell culture devices created using microchip manufacturing techniques that contain hollow microchannels lined by living cells, which recreate specialized tissue-tissue interfaces, physical microenvironments, and vascular perfusion necessary to recapitulate organ-level physiology in vitro. Here we describe a protocol for fabrication, culture, and operation of a human lung "small airway-on-a-chip," which contains a differentiated, mucociliary bronchiolar epithelium exposed to air and an underlying microvascular endothelium that experiences fluid flow. First, microengineering is used to fabricate a multilayered microfluidic device that contains two parallel elastomeric microchannels separated by a thin rigid porous membrane; this requires less than 1 day to complete. Next, primary human airway bronchiolar epithelial cells isolated from healthy normal donors or patients with respiratory disease are cultured on the porous membrane within one microchannel while lung microvascular endothelial cells are cultured on the opposite side of the same membrane in the second channel to create a mucociliated epithelium-endothelium interface; this process take about 4-6 weeks to complete. Finally, culture medium containing neutrophils isolated from fresh whole human blood are flowed through the microvascular channel of the device to enable real-time analysis of capture and recruitment of circulating leukocytes by endothelium under physiological shear; this step requires less than 1 day to complete. The small airway-on-a-chip represents a new microfluidic tool to model complex and dynamic inflammatory responses of healthy and diseased lungs in vitro.

Exploring the context of the lung proteome within the airway mucosa following allergen challenge.

PubMed

Fehniger, Thomas E; Sato-Folatre, José-Gabriel; Malmström, Johan; Berglund, Magnus; Lindberg, Claes; Brange, Charlotte; Lindberg, Henrik; Marko-Varga, György

2004-01-01

The lung proteome is a dynamic collection of specialized proteins related to pulmonary function. Many cells of different derivations, activation states, and levels of maturity contribute to the changing environment, which produces the lung proteome. Inflammatory cells reacting to environmental challenge, for example from allergens, produce and secrete proteins which have profound effects on both resident and nonresident cells located in airways, alveoli, and the vascular tree which provides blood cells to the parenchyma alveolar bed for gas exchange. In an experimental model of allergic airway inflammation, we have compared control and allergen challenged lung compartments to determine global protein expression patterns using 2D-gel electrophoresis and subsequent spot identification by MS/MS mass spectrometry. We have then specifically isolated the epithelial mucosal layer, which lines conducting airways, from control and allergen challenged lungs, using laser capture technology and performed proteome identification on these selected cell samples. A central component of our investigations has been to contextually relate the histological features of the dynamic pulmonary environment to the changes in protein expression observed following challenge. Our results provide new information of the complexity of the submucosa/epithelium interface and the mechanisms behind the transformation of airway epithelium from normal steady states to functionally activated states.

Morphological findings in the tracheal epithelium of dogs exposed to the inhalation of poorly conditioned gases under use of an endotracheal tube or laryngeal mask airway.

PubMed

Dias, Norimar Hernandes; Braz, José Reinaldo Cerqueira; Defaveri, Júlio; Carvalho, Lídia Raquel; Martins, Regina Helena Garcia

2011-10-01

To study morphological findings in the tracheal epithelium of dogs exposed to the inhalation of poorly conditioned gases under use of an endotracheal tube (ET) or laryngeal mask airway (LMA). Twelve dogs randomly were allocated to two groups: ET group (n-6) and LMA group (n-6), anaesthetized and mechanically ventilated, without CO(2) reabsorption. Haemodynamic and ventilatory parameters, tympanic temperature, temperature, relative and absolute humidity of the ambient and inhaled gases were analyzed during three hours. The animals were submitted to euthanasia and biopsies were carried out along the tracheal segment to morphological study. Three healthy dogs were used to morphological control. Inhaled gas temperature was maintained between 24ºC and 26ºC, relative humidity between 10% and 12%, and absolute humidity between 2 - 3 mg H(2)O.L(-1) with no significant differences between groups. In both groups, histological analysis showed epithelial inflammation and congestion in the corion and scanning electron microscopy showed ciliary grouping and disorganization. Transmission electron microscopy showed higher alterations in ET group than LMA group as widening of cell junctions, ciliary disorientation, cytoplasmic vacuolization, nuclear abnormalities, picnosis and chromatin condensation. LMA determined less pronounced changes in the tracheal epithelium in dogs exposed to the inhalation of poorly conditioned gases.

Onset of diabetes modulates the airway smooth muscle reactivity of guinea pigs: role of epithelial mediators.

PubMed

Saidullah, Bano; Muralidhar, Kambadur; Fahim, Mohammad

2014-01-01

Diabetes induces lung dysfunction, leading to alteration in the pulmonary functions. Our aim was to investigate whether the early stage of diabetes alters the epithelium-dependent bronchial responses and whether nitric oxide (NO), KATP channels and cyclooxygenase (COX) pathways contribute in this effect. Guinea pigs were treated with a single injection of streptozotocin (180 mg/kg, i.p.) for induction of diabetes. Airway conductivity was assessed by inhaled histamine, using a non-invasive body plethysmography. The contractile responses of tracheal rings induced by acetylcholine (ACh) and relaxant responses of precontracted rings, induced by isoproterenol (IP) were compared in the presence and absence of the epithelium. Effects of N(ω)-Nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor), glybenclamide (a KATP channel inhibitor) and indomethacin (a COX inhibitor) were also assessed in diabetic guinea pigs. Early stage diabetes did not alter the airway conductivity. ACh-induced bronchoconstriction in epithelium intact tracheal rings was not affected by the onset of diabetes, however a reduction in the increased ACh responses due to epithelium removal, to L-NAME or to indomethacin was observed. The relaxation response to IP was impaired in trachea from guinea pigs in which diabetes had just developed. Early diabetes significantly reduced the IP response to glybenclamide and to indomethacin. Our results demonstrate that the early stage of diabetes, modulate the bronchial reactivity to both ACh and IP by disrupting the NO, KATP channels and COX pathways, without affecting the airway conductivity in guinea pigs.

Structural Development, Cellular Differentiation and Proliferation of the Respiratory Epithelium in the Bovine Fetal Lung.

PubMed

Drozdowska, J; Cousens, C; Finlayson, J; Collie, D; Dagleish, M P

2016-01-01

Fetal bovine lung samples of 11 different gestational ages were assigned to a classical developmental stage based on histological morphology. Immunohistochemistry was used to characterize the morphology of forming airways, proliferation rate of airway epithelium and the presence of epithelial cell types (i.e. ciliated cells, club cells, neuroepithelial cells (NECs) and type II pneumocytes). Typical structural organization of pseudoglandular (84-98 days gestational age [DGA]), canalicular (154-168 DGA) and alveolar (224-266 DGA) stages was recognized. In addition, transitional pseudoglandular-canalicular (112-126 DGA) and canalicular-saccular (182 DGA) morphologies were present. The embryonic stage was not observed. A significantly (P <0.05) higher proliferation rate of pulmonary epithelium, on average 5.5% and 4.4% in bronchi and bronchioles, respectively, was present in the transitional pseudoglandular-canalicular phase (112-126 DGA) compared with all other phases, while from 8 weeks before term (224-266 DGA) proliferation had almost ceased. The first epithelial cells identified by specific marker proteins in the earliest samples available for study (84 DGA) were ciliated cells and NECs. Club cells were present initially at 112 DGA and type II pneumocytes at 224 DGA. At the latest time points (224-226 DGA) these latter cell types were still present at a much lower percentage compared with adult cattle. This study characterized bovine fetal lung development by histological morphology and cellular composition of the respiratory epithelium and suggests that the apparent structural anatomical maturity of the bovine lung at term is not matched by functional maturity of the respiratory epithelium. Copyright © 2015 Elsevier Ltd. All rights reserved.

How the airway smooth muscle in cystic fibrosis reacts in proinflammatory conditions: implications for airway hyper-responsiveness and asthma in cystic fibrosis.

PubMed

McCuaig, Sarah; Martin, James G

2013-04-01

Among patients with cystic fibrosis there is a high prevalence (40-70%) of asthma signs and symptoms such as cough and wheezing and airway hyper-responsiveness to inhaled histamine or methacholine. Whether these abnormal airway responses are due to a primary deficiency in the cystic fibrosis transmembrane conductance regulator (CFTR) or are secondary to the inflammatory environment in the cystic fibrosis lungs is not clear. A role for the CFTR in smooth muscle function is emerging, and alterations in contractile signalling have been reported in CFTR-deficient airway smooth muscle. Persistent bacterial infection, especially with Pseudomonas aeruginosa, stimulates interleukin-8 release from the airway epithelium, resulting in neutrophilic inflammation. Increased neutrophilia and skewing of CFTR-deficient T-helper cells to type 2 helper T cells creates an inflammatory environment characterised by high concentrations of tumour necrosis factor α, interleukin-8, and interleukin-13, which might all contribute to increased contractility of airway smooth muscle in cystic fibrosis. An emerging role of interleukin-17, which is raised in patients with cystic fibrosis, in airway smooth muscle proliferation and hyper-responsiveness is apparent. Increased understanding of the molecular mechanisms responsible for the altered smooth muscle physiology in patients with cystic fibrosis might provide insight into airway dysfunction in this disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of long-term administered CRAC channels blocker on the functions of respiratory epithelium in guinea pig allergic asthma model.

PubMed

Sutovska, Martina; Kocmalova, Michaela; Joskova, Marta; Adamkov, Marian; Franova, Sona

2015-04-01

Previously, therapeutic potency of CRAC channels blocker was evidenced as a significant decrease in airway smooth muscle hyperreactivity, antitussive and anti-inflammatory effects. The major role of the respiratory epithelium in asthma pathogenesis was highlighted only recently and CRAC channels were proposed as the most significant route of Ca2+ entry into epithelial cells. The aim of the study was to analyse the impact of long-term administered CRAC channels blocker on airway epithelium, e.g. cytokine production and ciliary beat frequency (CBF) using an animal model of allergic asthma. Ovalbumin-induced allergic airway inflammation of guinea pigs was followed by long-term (14 days lasted) therapy by CRAC blocker (3-fluoropyridine-4-carboxylic acid, FPCA). The influence of long-term therapy on cytokines (IL-4, IL-5 and IL-13) in BALF and in plasma, immunohistochemical staining of pulmonary tissue (c-Fos positivity) and CBF in vitro were used for analysis. Decrease in cytokine levels and in c-Fos positivity confirmed an anti-inflammatory effect of long-term administered FPCA. Cytokine levels in BALF and distribution of c-Fos positivity suggested that FPCA was a more potent inhibitor of respiratory epithelium secretory functions than budesonide. FPCA and budesonide reduced CBF only insignificantly. All findings supported CRAC channels as promising target in the new strategy of antiasthmatic treatment.

Popcorn flavoring effects on reactivity of rat airways in vivo and in vitro.

PubMed

Zaccone, Eric J; Thompson, Janet A; Ponnoth, Dovenia S; Cumpston, Amy M; Goldsmith, W Travis; Jackson, Mark C; Kashon, Michael L; Frazer, David G; Hubbs, Ann F; Shimko, Michael J; Fedan, Jeffrey S

2013-01-01

"Popcorn workers' lung" is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 h after a 6-h inhalation exposure to diacetyl or 2,3-pentanedione (100-360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (≥3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism.

POPCORN FLAVORING EFFECTS ON REACTIVITY OF RAT AIRWAYS IN VIVO AND IN VITRO

PubMed Central

Zaccone, Eric J.; Thompson, Janet A.; Ponnoth, Dovenia S.; Cumpston, Amy M.; Goldsmith, W. Travis; Jackson, Mark C.; Kashon, Michael L.; Frazer, David G.; Hubbs, Ann F.; Shimko, Michael J.; Fedan, Jeffrey S.

2015-01-01

“Popcorn workers’ lung” is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 h after a 6-h inhalation exposure to diacetyl or 2,3-pentanedione (100–360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (≥3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism. PMID:23941636

HIV Impairs Lung Epithelial Integrity and Enters the Epithelium to Promote Chronic Lung Inflammation.

PubMed

Brune, Kieran A; Ferreira, Fernanda; Mandke, Pooja; Chau, Eric; Aggarwal, Neil R; D'Alessio, Franco R; Lambert, Allison A; Kirk, Gregory; Blankson, Joel; Drummond, M Bradley; Tsibris, Athe M; Sidhaye, Venkataramana K

2016-01-01

Several clinical studies show that individuals with HIV are at an increased risk for worsened lung function and for the development of COPD, although the mechanism underlying this increased susceptibility is poorly understood. The airway epithelium, situated at the interface between the external environment and the lung parenchyma, acts as a physical and immunological barrier that secretes mucins and cytokines in response to noxious stimuli which can contribute to the pathobiology of chronic obstructive pulmonary disease (COPD). We sought to determine the effects of HIV on the lung epithelium. We grew primary normal human bronchial epithelial (NHBE) cells and primary lung epithelial cells isolated from bronchial brushings of patients to confluence and allowed them to differentiate at an air- liquid interface (ALI) to assess the effects of HIV on the lung epithelium. We assessed changes in monolayer permeability as well as the expression of E-cadherin and inflammatory modulators to determine the effect of HIV on the lung epithelium. We measured E-cadherin protein abundance in patients with HIV compared to normal controls. Cell associated HIV RNA and DNA were quantified and the p24 viral antigen was measured in culture supernatant. Surprisingly, X4, not R5, tropic virus decreased expression of E-cadherin and increased monolayer permeability. While there was some transcriptional regulation of E-cadherin, there was significant increase in lysosome-mediated protein degradation in cells exposed to X4 tropic HIV. Interaction with CXCR4 and viral fusion with the epithelial cell were required to induce the epithelial changes. X4 tropic virus was able to enter the airway epithelial cells but not replicate in these cells, while R5 tropic viruses did not enter the epithelial cells. Significantly, X4 tropic HIV induced the expression of intercellular adhesion molecule-1 (ICAM-1) and activated extracellular signal-regulated kinase (ERK). We demonstrate that HIV can enter airway

Airway hyperresponsiveness; smooth muscle as the principal actor

PubMed Central

Lauzon, Anne-Marie; Martin, James G.

2016-01-01

Airway hyperresponsiveness (AHR) is a defining characteristic of asthma that refers to the capacity of the airways to undergo exaggerated narrowing in response to stimuli that do not result in comparable degrees of airway narrowing in healthy subjects. Airway smooth muscle (ASM) contraction mediates airway narrowing, but it remains uncertain as to whether the smooth muscle is intrinsically altered in asthmatic subjects or is responding abnormally as a result of the milieu in which it sits. ASM in the trachea or major bronchi does not differ in its contractile characteristics in asthmatics, but the more pertinent peripheral airways await complete exploration. The mass of ASM is increased in many but not all asthmatics and therefore cannot be a unifying hypothesis for AHR, although when increased in mass it may contribute to AHR. The inability of a deep breath to reverse or prevent bronchial narrowing in asthma may reflect an intrinsic difference in the mechanisms that lead to softening of contracted ASM when subjected to stretch. Cytokines such as interleukin-13 and tumor necrosis factor-α promote a more contractile ASM phenotype. The composition and increased stiffness of the matrix in which ASM is embedded promotes a more proliferative and pro-inflammatory ASM phenotype, but the expected dedifferentiation and loss of contractility have not been shown. Airway epithelium may drive ASM proliferation and/or molecular remodeling in ways that may lead to AHR. In conclusion, AHR is likely multifactorial in origin, reflecting the plasticity of ASM properties in the inflammatory environment of the asthmatic airway. PMID:26998246

Manipulation of Cell Physiology Enables Gene Silencing in Well-differentiated Airway Epithelia

PubMed Central

Krishnamurthy, Sateesh; Behlke, Mark A; Ramachandran, Shyam; Salem, Aliasger K; McCray Jr, Paul B; Davidson, Beverly L

2012-01-01

The application of RNA interference-based gene silencing to the airway surface epithelium holds great promise to manipulate host and pathogen gene expression for therapeutic purposes. However, well-differentiated airway epithelia display significant barriers to double-stranded small-interfering RNA (siRNA) delivery despite testing varied classes of nonviral reagents. In well-differentiated primary pig airway epithelia (PAE) or human airway epithelia (HAE) grown at the air–liquid interface (ALI), the delivery of a Dicer-substrate small-interfering RNA (DsiRNA) duplex against hypoxanthine–guanine phosphoribosyltransferase (HPRT) with several nonviral reagents showed minimal uptake and no knockdown of the target. In contrast, poorly differentiated cells (2–5-day post-seeding) exhibited significant oligonucleotide internalization and target knockdown. This finding suggested that during differentiation, the barrier properties of the epithelium are modified to an extent that impedes oligonucleotide uptake. We used two methods to overcome this inefficiency. First, we tested the impact of epidermal growth factor (EGF), a known enhancer of macropinocytosis. Treatment of the cells with EGF improved oligonucleotide uptake resulting in significant but modest levels of target knockdown. Secondly, we used the connectivity map (Cmap) database to correlate gene expression changes during small molecule treatments on various cells types with genes that change upon mucociliary differentiation. Several different drug classes were identified from this correlative assessment. Well-differentiated epithelia treated with DsiRNAs and LY294002, a PI3K inhibitor, significantly improved gene silencing and concomitantly reduced target protein levels. These novel findings reveal that well-differentiated airway epithelia, normally resistant to siRNA delivery, can be pretreated with small molecules to improve uptake of synthetic oligonucleotide and RNA interference (RNAi) responses. PMID

Airway epithelial phosphoinositide 3-kinase-δ contributes to the modulation of fungi-induced innate immune response.

PubMed

Jeong, Jae Seok; Lee, Kyung Bae; Kim, So Ri; Kim, Dong Im; Park, Hae Jin; Lee, Hern-Ku; Kim, Hyung Jin; Cho, Seong Ho; Kolliputi, Narasaiah; Kim, Soon Ha; Lee, Yong Chul

2018-04-05

Respiratory fungal exposure is known to be associated with severe allergic lung inflammation. Airway epithelium is an essential controller of allergic inflammation. An innate immune recognition receptor, nucleotide-binding domain, leucine-rich-containing family, pyrin-domain-containing-3 (NLRP3) inflammasome, and phosphoinositide 3 kinase (PI3K)-δ in airway epithelium are involved in various inflammatory processes. We investigated the role of NLRP3 inflammasome in fungi-induced allergic lung inflammation and examined the regulatory mechanism of NLRP3 inflammasome, focusing on PI3K-δ in airway epithelium. We used two in vivo models induced by exposure to Aspergillus fumigatus ( Af ) and Alternaria alternata ( Aa ), as well as an Af -exposed in vitro system. We also checked NLRP3 expression in lung tissues from patients with allergic bronchopulmonary aspergillosis (ABPA). Assembly/activation of NLRP3 inflammasome was increased in the lung of Af -exposed mice. Elevation of NLRP3 inflammasome assembly/activation was observed in Af -stimulated murine and human epithelial cells. Similarly, pulmonary expression of NLRP3 in patients with ABPA was increased. Importantly, neutralisation of NLRP3 inflammasome derived IL-1β alleviated pathophysiological features of Af -induced allergic inflammation. Furthermore, PI3K-δ blockade improved Af -induced allergic inflammation through modulation of NLRP3 inflammasome, especially in epithelial cells. This modulatory role of PI3K-δ was mediated through the regulation of mitochondrial reactive oxygen species (mtROS) generation. NLRP3 inflammasome was also implicated in Aa -induced eosinophilic allergic inflammation, which was improved by PI3K-δ blockade. These findings demonstrate that fungi-induced assembly/activation of NLRP3 inflammasome in airway epithelium may be modulated by PI3K-δ, which is mediated partly through the regulation of mtROS generation. Inhibition of PI3K-δ may have potential for treating fungi-induced severe

The multi-faceted role of allergen exposure to the local airway mucosa.

PubMed

Golebski, K; Röschmann, K I L; Toppila-Salmi, S; Hammad, H; Lambrecht, B N; Renkonen, R; Fokkens, W J; van Drunen, C M

2013-02-01

Airway epithelial cells are the first to encounter aeroallergens and therefore have recently become an interesting target of many studies investigating their involvement in the modulation of allergic inflammatory responses. Disruption of a passive structural barrier composed of epithelial cells by intrinsic proteolytic activity of allergens may facilitate allergen penetration into local tissues and additionally affect chronic and ongoing inflammatory processes in respiratory tissues. Furthermore, the ability of rhinoviruses to disrupt and interfere with epithelial tight junctions may alter the barrier integrity and enable a passive passage of inhaled allergens through the airway epithelium. On the other hand, epithelial cells are no longer considered to act only as a physical barrier toward inhaled allergens, but also to actively contribute to airway inflammation by detecting and responding to environmental factors. Epithelial cells can produce mediators, which may affect the recruitment and activation of more specialized immune cells to the local tissue and also create a microenvironment in which these activated immune cells may function and propagate the inflammatory processes. This review presents the dual role of epithelium acting as a passive and active barrier when encountering an inhaled allergen and how this double role contributes to the start of local immune responses. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

The human airway trypsin-like protease modulates the urokinase receptor (uPAR, CD87) structure and functions.

PubMed

Beaufort, Nathalie; Leduc, Dominique; Eguchi, Hiroshi; Mengele, Karin; Hellmann, Daniela; Masegi, Tsukio; Kamimura, Takashi; Yasuoka, Susumu; Fend, Falko; Chignard, Michel; Pidard, Dominique

2007-05-01

The human airway trypsin-like protease (HAT) is a respiratory epithelium-associated, type II transmembrane serine protease, which is also detected as an extracellular enzyme in lung fluids during airway inflammatory disorders. We have evaluated its capacity to affect the urokinase-type plasminogen activator receptor (uPAR), a membrane glycolipid-anchored, three-domain (D1D2D3) glycoprotein that plays a crucial role in innate immunity and inflammation by supporting cell migration and matrix degradation, with structure and biological properties that can be regulated via limited endoproteolysis. With the use of immunoblotting, flow immunocytometry, and ELISA analyses applied to a recombinant uPAR protein and to uPAR-expressing monocytic and human bronchial epithelial cells, it was shown that exposure of uPAR to soluble HAT in the range of 10-500 nM resulted in the proteolytic processing of the full-length (D1D2D3) into the truncated (D2D3) species, with cleavage occurring in the D1 to D2 linker sequence after arginine residues at position 83 and 89. Using immunohistochemistry, we found that both HAT and uPAR were expressed in the human bronchial epithelium. Moreover, transient cotransfection in epithelial cells showed that membrane coexpression of the two partners produced a constitutive and extensive shedding of the D1 domain, occurring for membrane-associated HAT concentrations in the nanomolar range. Because the truncated receptor was found to be unable to bind two of the major uPAR ligands, the adhesive matrix protein vitronectin and the serine protease urokinase, it thus appears that proteolytic regulation of uPAR by HAT is likely to modulate cell adherence and motility, as well as tissue remodeling during the inflammatory response in the airways.

Composition of nasal airway surface liquid in cystic fibrosis and other airway diseases determined by X-ray microanalysis.

PubMed

Vanthanouvong, V; Kozlova, I; Johannesson, M; Nääs, E; Nordvall, S L; Dragomir, A; Roomans, G M

2006-04-01

The ionic composition of the airway surface liquid (ASL) in healthy individuals and in patients with cystic fibrosis (CF) has been debated. Ion transport properties of the upper airway epithelium are similar to those of the lower airways and it is easier to collect nasal ASL from the nose. ASL was collected with ion exchange beads, and the elemental composition of nasal fluid was determined by X-ray microanalysis in healthy subjects, CF patients, CF heterozygotes, patients with rhinitis, and with primary ciliary dyskinesia (PCD). In healthy subjects, the ionic concentrations were approximately isotonic. In CF patients, CF heterozygotes, rhinitis, and PCD patients, [Na] and [Cl] were significantly higher compared when compared with those in controls. [K] was significantly higher in CF and PCD patients compared with that in controls. Severely affected CF patients had higher ionic concentrations in their nasal ASL than in patients with mild or moderate symptoms. Female CF patients had higher levels of Na, Cl, and K than male patients. As higher salt concentrations in the ASL are also found in other patients with airway diseases involving chronic inflammation, it appears likely that inflammation-induced epithelial damage is important in determining the ionic composition of the ASL. Copyright (c) 2006 Wiley-Liss, Inc.

Nitric oxide deficiency contributes to impairment of airway relaxation in cystic fibrosis mice.

PubMed

Mhanna, M J; Ferkol, T; Martin, R J; Dreshaj, I A; van Heeckeren, A M; Kelley, T J; Haxhiu, M A

2001-05-01

The pulmonary disease of cystic fibrosis (CF) is characterized by persistent airway obstruction, which has been attributed to chronic endobronchial infection and inflammation. The levels of exhaled nitric oxide (NO) are reduced in CF patients, which could contribute to bronchial obstruction through dysregulated constriction of airway smooth muscle. Because airway epithelium from CF mice has been shown to have reduced expression of inducible NO synthase, we examined airway responsiveness and relaxation in isolated tracheas of CF mice. Airway relaxation as measured by percent relaxation of precontracted tracheal segments to electrical field stimulation (EFS) and substance P, a nonadrenergic, noncholinergic substance, was significantly impaired in CF mice. The airway relaxation in response to prostaglandin E2 was similar in CF and non-CF animals. Treatment with the NO synthase inhibitor NG-nitro-L-arginine methylester reduced tracheal relaxation induced by EFS in wild-type animals but had virtually no effect in the CF mice. Conversely, exogenous NO and L-arginine, a NO substrate, reversed the relaxation defect in CF airway. We conclude that the relative absence of NO compromises airways relaxation in CF, and may contribute to the bronchial obstruction seen in the disease.

Airway inflammation in chronic obstructive pulmonary disease (COPD): a true paradox.

PubMed

Eapen, Mathew Suji; Myers, Stephen; Walters, Eugene Haydn; Sohal, Sukhwinder Singh

2017-10-01

Chronic obstructive pulmonary disease (COPD) is primarily an airway condition, which mainly affects cigarette smokers and presents with shortness of breath that is progressive and poorly reversible. In COPD research, there has been a long held belief that airway disease progression is due to inflammation. Although this may be true in the airway lumen with innate immunity activated by the effect of smoke or secondary to infection, the accurate picture of inflammatory cells in the airway wall, where the pathophysiological COPD remodeling occurs, is uncertain and debatable. Areas covered: The current review provides a comprehensive literature survey of the changes in the main inflammatory cells in human COPD patients and focuses on contrarian views that affect the prevailing dogma on inflammation. The review also delves into the role of oxidative stress and inflammasomes in modulating the immune response in COPD. Further, the effects of inflammation in affecting the epithelium, fibroblasts, and airway remodeling are discussed. Expert commentary: Inflammation as a driving force for airway wall damage and remodelling in early COPD is at the very least 'oversimplified' and is likely to be misleading. This has serious implications for rational thinking about the illness, including pathogenesis and designing therapy.

Notch3-Jagged signaling controls the pool of undifferentiated airway progenitors

PubMed Central

Mori, Munemasa; Mahoney, John E.; Stupnikov, Maria R.; Paez-Cortez, Jesus R.; Szymaniak, Aleksander D.; Varelas, Xaralabos; Herrick, Dan B.; Schwob, James; Zhang, Hong; Cardoso, Wellington V.

2015-01-01

Basal cells are multipotent airway progenitors that generate distinct epithelial cell phenotypes crucial for homeostasis and repair of the conducting airways. Little is known about how these progenitor cells expand and transition to differentiation to form the pseudostratified airway epithelium in the developing and adult lung. Here, we show by genetic and pharmacological approaches that endogenous activation of Notch3 signaling selectively controls the pool of undifferentiated progenitors of upper airways available for differentiation. This mechanism depends on the availability of Jag1 and Jag2, and is key to generating a population of parabasal cells that later activates Notch1 and Notch2 for secretory-multiciliated cell fate selection. Disruption of this mechanism resulted in aberrant expansion of basal cells and altered pseudostratification. Analysis of human lungs showing similar abnormalities and decreased NOTCH3 expression in subjects with chronic obstructive pulmonary disease suggests an involvement of NOTCH3-dependent events in the pathogenesis of this condition. PMID:25564622

Activation of Influenza A Viruses by Host Proteases from Swine Airway Epithelium

PubMed Central

Peitsch, Catharina; Klenk, Hans-Dieter; Garten, Wolfgang

2014-01-01

Pigs are important natural hosts of influenza A viruses, and due to their susceptibility to swine, avian, and human viruses, they may serve as intermediate hosts supporting adaptation and genetic reassortment. Cleavage of the influenza virus surface glycoprotein hemagglutinin (HA) by host cell proteases is essential for viral infectivity. Most influenza viruses, including human and swine viruses, are activated at a monobasic HA cleavage site, and we previously identified TMPRSS2 and HAT to be relevant proteases present in human airways. We investigated the proteolytic activation of influenza viruses in primary porcine tracheal and bronchial epithelial cells (PTEC and PBEC, respectively). Human H1N1 and H3N2 viruses replicated efficiently in PTECs and PBECs, and viruses containing cleaved HA were released from infected cells. Moreover, the cells supported the proteolytic activation of HA at the stage of entry. We found that swine proteases homologous to TMPRSS2 and HAT, designated swTMPRSS2 and swAT, respectively, were expressed in several parts of the porcine respiratory tract. Both proteases cloned from primary PBECs were shown to activate HA with a monobasic cleavage site upon coexpression and support multicycle replication of influenza viruses. swAT was predominantly localized at the plasma membrane, where it was present as an active protease that mediated activation of incoming virus. In contrast, swTMPRSS2 accumulated in the trans-Golgi network, suggesting that it cleaves HA in this compartment. In conclusion, our data show that HA activation in porcine airways may occur by similar proteases and at similar stages of the viral life cycle as in human airways. PMID:24155384

Impaired airway epithelial cell responses from children with asthma to rhinoviral infection.

PubMed

Kicic, A; Stevens, P T; Sutanto, E N; Kicic-Starcevich, E; Ling, K-M; Looi, K; Martinovich, K M; Garratt, L W; Iosifidis, T; Shaw, N C; Buckley, A G; Rigby, P J; Lannigan, F J; Knight, D A; Stick, S M

2016-11-01

The airway epithelium forms an effective immune and physical barrier that is essential for protecting the lung from potentially harmful inhaled stimuli including viruses. Human rhinovirus (HRV) infection is a known trigger of asthma exacerbations, although the mechanism by which this occurs is not fully understood. To explore the relationship between apoptotic, innate immune and inflammatory responses to HRV infection in airway epithelial cells (AECs) obtained from children with asthma and non-asthmatic controls. In addition, to test the hypothesis that aberrant repair of epithelium from asthmatics is further dysregulated by HRV infection. Airway epithelial brushings were obtained from 39 asthmatic and 36 non-asthmatic children. Primary cultures were established and exposed to HRV1b and HRV14. Virus receptor number, virus replication and progeny release were determined. Epithelial cell apoptosis, IFN-β production, inflammatory cytokine release and epithelial wound repair and proliferation were also measured. Virus proliferation and release was greater in airway epithelial cells from asthmatics but this was not related to the number of virus receptors. In epithelial cells from asthmatic children, virus infection dampened apoptosis, reduced IFN-β production and increased inflammatory cytokine production. HRV1b infection also inhibited wound repair capacity of epithelial cells isolated from non-asthmatic children and exaggerated the defective repair response seen in epithelial cells from asthmatics. Addition of IFN-β restored apoptosis, suppressed virus replication and improved repair of airway epithelial cells from asthmatics but did not reduce inflammatory cytokine production. Collectively, HRV infection delays repair and inhibits apoptotic processes in epithelial cells from non-asthmatic and asthmatic children. The delayed repair is further exaggerated in cells from asthmatic children and is only partially reversed by exogenous IFN-β. © 2016 John Wiley & Sons

Serelaxin Elicits Bronchodilation and Enhances β-Adrenoceptor-Mediated Airway Relaxation

PubMed Central

Lam, Maggie; Royce, Simon G.; Donovan, Chantal; Jelinic, Maria; Parry, Laura J.; Samuel, Chrishan S.; Bourke, Jane E.

2016-01-01

Treatment with β-adrenoceptor agonists does not fully overcome the symptoms associated with severe asthma. Serelaxin elicits potent uterine and vascular relaxation via its cognate receptor, RXFP1, and nitric oxide (NO) signaling, and is being clinically evaluated for the treatment of acute heart failure. However, its direct bronchodilator efficacy has yet to be explored. Tracheal rings were prepared from male Sprague-Dawley rats (250–350 g) and tricolor guinea pigs, and precision cut lung slices (PCLSs) containing intrapulmonary airways were prepared from rats only. Recombinant human serelaxin (rhRLX) alone and in combination with rosiglitazone (PPARγ agonist; recently described as a novel dilator) or β-adrenoceptor agonists (isoprenaline, salbutamol) were added either to pre-contracted airways, or before contraction with methacholine or endothelin-1. Regulation of rhRLX responses by epithelial removal, indomethacin (cyclooxygenase inhibitor), L-NAME (nitric oxide synthase inhibitor), SQ22536 (adenylate cyclase inhibitor) and ODQ (guanylate cyclase inhibitor) were also evaluated. Immunohistochemistry was used to localize RXFP1 to airway epithelium and smooth muscle. rhRLX elicited relaxation in rat trachea and PCLS, more slowly than rosiglitazone or isoprenaline, but potentiated relaxation to both these dilators. It markedly increased β-adrenoceptor agonist potency in guinea pig trachea. rhRLX, rosiglitazone, and isoprenaline pretreatment also inhibited the development of rat tracheal contraction. Bronchoprotection by rhRLX increased with longer pre-incubation time, and was partially reduced by epithelial removal, indomethacin and/or L-NAME. SQ22536 and ODQ also partially inhibited rhRLX-mediated relaxation in both intact and epithelial-denuded trachea. RXFP1 expression in the airways was at higher levels in epithelium than smooth muscle. In summary, rhRLX elicits large and small airway relaxation via epithelial-dependent and -independent mechanisms, likely

Lubiprostone targets prostanoid EP₄ receptors in ovine airways.

PubMed

Cuthbert, A W

2011-01-01

Lubiprostone, a prostaglandin E₁ derivative, is reported to activate ClC-2 chloride channels located in the apical membranes of a number of transporting epithelia. Lack of functioning CFTR chloride channels in epithelia is responsible for the genetic disease cystic fibrosis, therefore, surrogate channels that can operate independently of CFTR are of interest. This study explores the target receptor(s) for lubiprostone in airway epithelium. All experiments were performed on the ventral tracheal epithelium of sheep. Epithelia were used to measure anion secretion from the apical surface as short circuit current or as fluid secretion from individual airway submucosal glands, using an optical method. The EP₄ antagonists L-161982 and GW627368 inhibited short circuit current responses to lubiprostone, while EP₁(,)₂(&)₃ receptor antagonists were without effect. Similarly, lubiprostone induced secretion in airway submucosal glands was inhibited by L-161982. L-161982 effectively competed with lubiprostone with a K(d) value of 0.058 µM, close to its value for binding to human EP₄ receptors (0.024 µM). The selective EP₄ agonist L-902688 and lubiprostone behaved similarly with respect to EP₄ receptor antagonists. Results of experiments with H89, a protein kinase A inhibitor, were consistent with lubiprostone acting through a G(s) -protein coupled EP₄ receptor/cAMP cascade. Lubiprostone-induced short-circuit currents and submucosal gland secretions were inhibited by selective EP₄ receptor antagonists. The results suggest EP₄ receptor activation by lubiprostone triggers cAMP production necessary for CFTR activation and the secretory responses, a possibility precluded in CF tissues. © 2010 The Author. British Journal of Pharmacology © 2010 The British Pharmacological Society.

Autofluorescence multiphoton microscopy for visualization of tissue morphology and cellular dynamics in murine and human airways.

PubMed

Kretschmer, Sarah; Pieper, Mario; Hüttmann, Gereon; Bölke, Torsten; Wollenberg, Barbara; Marsh, Leigh M; Garn, Holger; König, Peter

2016-08-01

The basic understanding of inflammatory airway diseases greatly benefits from imaging the cellular dynamics of immune cells. Current imaging approaches focus on labeling specific cells to follow their dynamics but fail to visualize the surrounding tissue. To overcome this problem, we evaluated autofluorescence multiphoton microscopy for following the motion and interaction of cells in the airways in the context of tissue morphology. Freshly isolated murine tracheae from healthy mice and mice with experimental allergic airway inflammation were examined by autofluorescence multiphoton microscopy. In addition, fluorescently labeled ovalbumin and fluorophore-labeled antibodies were applied to visualize antigen uptake and to identify specific cell populations, respectively. The trachea in living mice was imaged to verify that the ex vivo preparation reflects the in vivo situation. Autofluorescence multiphoton microscopy was also tested to examine human tissue from patients in short-term tissue culture. Using autofluorescence, the epithelium, underlying cells, and fibers of the connective tissue, as well as blood vessels, were identified in isolated tracheae. Similar structures were visualized in living mice and in the human airway tissue. In explanted murine airways, mobile cells were localized within the tissue and we could follow their migration, interactions between individual cells, and their phagocytic activity. During allergic airway inflammation, increased number of eosinophil and neutrophil granulocytes were detected that moved within the connective tissue and immediately below the epithelium without damaging the epithelial cells or connective tissues. Contacts between granulocytes were transient lasting 3 min on average. Unexpectedly, prolonged interactions between granulocytes and antigen-uptaking cells were observed lasting for an average of 13 min. Our results indicate that autofluorescence-based imaging can detect previously unknown immune cell

Airway Basal Cells. The “Smoking Gun” of Chronic Obstructive Pulmonary Disease

PubMed Central

2014-01-01

The earliest abnormality in the lung associated with smoking is hyperplasia of airway basal cells, the stem/progenitor cells of the ciliated and secretory cells that are central to pulmonary host defense. Using cell biology and ’omics technologies to assess basal cells isolated from bronchoscopic brushings of nonsmokers, smokers, and smokers with chronic obstructive pulmonary disease (COPD), compelling evidence has been provided in support of the concept that airway basal cells are central to the pathogenesis of smoking-associated lung diseases. When confronted by the chronic stress of smoking, airway basal cells become disorderly, regress to a more primitive state, behave as dictated by their inheritance, are susceptible to acquired changes in their genome, lose the capacity to regenerate the epithelium, are responsible for the major changes in the airway that characterize COPD, and, with persistent stress, can undergo malignant transformation. Together, these observations led to the conclusion that accelerated loss of lung function in susceptible individuals begins with disordered airway basal cell biology (i.e., that airway basal cells are the “smoking gun” of COPD, a potential target for the development of therapies to prevent smoking-related lung disorders). PMID:25354273

Host-microbe interactions in distal airways: relevance to chronic airway diseases.

PubMed

Martin, Clémence; Burgel, Pierre-Régis; Lepage, Patricia; Andréjak, Claire; de Blic, Jacques; Bourdin, Arnaud; Brouard, Jacques; Chanez, Pascal; Dalphin, Jean-Charles; Deslée, Gaetan; Deschildre, Antoine; Gosset, Philippe; Touqui, Lhousseine; Dusser, Daniel

2015-03-01

This article is the summary of a workshop, which took place in November 2013, on the roles of microorganisms in chronic respiratory diseases. Until recently, it was assumed that lower airways were sterile in healthy individuals. However, it has long been acknowledged that microorganisms could be identified in distal airway secretions from patients with various respiratory diseases, including cystic fibrosis (CF) and non-CF bronchiectasis, chronic obstructive pulmonary disease, asthma and other chronic airway diseases (e.g. post-transplantation bronchiolitis obliterans). These microorganisms were sometimes considered as infectious agents that triggered host immune responses and contributed to disease onset and/or progression; alternatively, microorganisms were often considered as colonisers, which were considered unlikely to play roles in disease pathophysiology. These concepts were developed at a time when the identification of microorganisms relied on culture-based methods. Importantly, the majority of microorganisms cannot be cultured using conventional methods, and the use of novel culture-independent methods that rely on the identification of microorganism genomes has revealed that healthy distal airways display a complex flora called the airway microbiota. The present article reviews some aspects of current literature on host-microbe (mostly bacteria and viruses) interactions in healthy and diseased airways, with a special focus on distal airways. Copyright ©ERS 2015.

Arsenic Alters ATP-Dependent Ca2+ Signaling in Human Airway Epithelial Cell Wound Response

PubMed Central

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

2011-01-01

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., < 4μM 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

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.

Operative endoscopy of the airway

PubMed Central

Walters, Dustin M.

2016-01-01

Airway endoscopy has long been an important and useful tool in the management of thoracic diseases. As thoracic specialists have gained experience with both flexible and rigid bronchoscopic techniques, the technology has continued to evolve so that bronchoscopy is currently the foundation for diagnosis and treatment of many thoracic ailments. Airway endoscopy plays a significant role in the biopsy of tumors within the airways, mediastinum, and lung parenchyma. Endoscopic methods have been developed to treat benign and malignant airway stenoses and tracheomalacia. And more recently, techniques have been conceived to treat end-stage emphysema and prolonged air leaks in select patients. This review describes the abundant uses of airway endoscopy, as well as technical considerations and limitations of the current technologies. PMID:26981263

Airway epithelial wounds in rhesus monkey generate ionic currents that guide cell migration to promote healing

PubMed Central

Sun, Yao-Hui; Reid, Brian; Fontaine, Justin H.; Miller, Lisa A.; Hyde, Dallas M.; Mogilner, Alex

2011-01-01

Damage to the respiratory epithelium is one of the most critical steps to many life-threatening diseases, such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. The mechanisms underlying repair of the damaged epithelium have not yet been fully elucidated. Here we provide experimental evidence suggesting a novel mechanism for wound repair: endogenous electric currents. It is known that the airway epithelium maintains a voltage difference referred to as the transepithelial potential. Using a noninvasive vibrating probe, we demonstrate that wounds in the epithelium of trachea from rhesus monkeys generate significant outward electric currents. A small slit wound produced an outward current (1.59 μA/cm2), which could be enhanced (nearly doubled) by the ion transport stimulator aminophylline. In addition, inhibiting cystic fibrosis transmembrane conductance regulator (CFTR) with CFTR(Inh)-172 significantly reduced wound currents (0.17 μA/cm2), implicating an important role of ion transporters in wound induced electric potentials. Time-lapse video microscopy showed that applied electric fields (EFs) induced robust directional migration of primary tracheobronchial epithelial cells from rhesus monkeys, towards the cathode, with a threshold of <23 mV/mm. Reversal of the field polarity induced cell migration towards the new cathode. We further demonstrate that application of an EF promoted wound healing in a monolayer wound healing assay. Our results suggest that endogenous electric currents at sites of tracheal epithelial injury may direct cell migration, which could benefit restitution of damaged airway mucosa. Manipulation of ion transport may lead to novel therapeutic approaches to repair damaged respiratory epithelium. PMID:21719726

Cellular distribution and function of ion channels involved in transport processes in rat tracheal epithelium.

PubMed

Hahn, Anne; Faulhaber, Johannes; Srisawang, Lalita; Stortz, Andreas; Salomon, Johanna J; Mall, Marcus A; Frings, Stephan; Möhrlen, Frank

2017-06-01

Transport of water and electrolytes in airway epithelia involves chloride-selective ion channels, which are controlled either by cytosolic Ca 2+ or by cAMP The contributions of the two pathways to chloride transport differ among vertebrate species. Because rats are becoming more important as animal model for cystic fibrosis, we have examined how Ca 2+ - dependent and cAMP- dependent Cl - secretion is organized in the rat tracheal epithelium. We examined the expression of the Ca 2+ -gated Cl - channel anoctamin 1 (ANO1), the cystic fibrosis transmembrane conductance regulator (CFTR) Cl - channel, the epithelial Na + channel ENaC, and the water channel aquaporin 5 (AQP5) in rat tracheal epithelium. The contribution of ANO1 channels to nucleotide-stimulated Cl - secretion was determined using the channel blocker Ani9 in short-circuit current recordings obtained from primary cultures of rat tracheal epithelial cells in Ussing chambers. We found that ANO1, CFTR and AQP5 proteins were expressed in nonciliated cells of the tracheal epithelium, whereas ENaC was expressed in ciliated cells. Among nonciliated cells, ANO1 occurred together with CFTR and Muc5b and, in addition, in a different cell type without CFTR and Muc5b. Bioelectrical studies with the ANO1-blocker Ani9 indicated that ANO1 mediated the secretory response to the nucleotide uridine-5'-triphosphate. Our data demonstrate that, in rat tracheal epithelium, Cl - secretion and Na + absorption are routed through different cell types, and that ANO1 channels form the molecular basis of Ca 2+ -dependent Cl - secretion in this tissue. These characteristic features of Cl - -dependent secretion reveal similarities and distinct differences to secretory processes in human airways. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Swine confinement buildings: effects of airborne particles and settled dust on airway smooth muscles.

PubMed

Demanche, Annick; Bonlokke, Jakob; Beaulieu, Marie-Josee; Assayag, Evelyne; Cormier, Yvon

2009-01-01

Swine confinement workers are exposed to various contaminants. These agents can cause airway inflammation and bronchoconstriction. This study was undertaken to evaluate if the bronchoconstrictive effects of swine barn air and settled dust are mediated by endotoxin, and if these effects are directly mediated on airway smooth muscles. Mouse tracheas where isolated and mounted isometrically in organ baths. Tracheas, with or without epithelium, were attached to a force transducer and tension was recorded. Concentrated swine building air at 68 EU/ml or settled dust extract at 0.01 g/ml were added for 20 minutes and tracheal smooth muscle contraction was measured. Direct role of LPS was assessed by removing it from air concentrates with an endotoxin affinity resin. Swine barn air and settled dust extract caused contraction of tracheal smooth muscle by 26 and 20%, respectively, of the maximal induced by methacholine. Removal of epithelium did not affect the contractile effects. LPS alone and LPS with peptidoglycans did not induce contraction. However, when endotoxin was removed from swine barn air concentrates, it lost 24% of its contractile effect. Concentrated swine barn air and settled dust have direct effects on airway smooth muscles. This effect is partially due to LPS but a synergy with other components of the environment of swine confinement buildings is required.

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

PubMed

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; Mall, Marcus A; Bracke, Ken R

2015-01-01

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. 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). 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. 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. We conclude that airway surface dehydration is a risk factor that aggravates CS-induced hallmarks of COPD.

Fank1 and Jazf1 promote multiciliated cell differentiation in the mouse airway epithelium

PubMed Central

Johnson, Jo-Anne; Watson, Julie K.

2018-01-01

ABSTRACT The airways are lined by secretory and multiciliated cells which function together to remove particles and debris from the respiratory tract. The transcriptome of multiciliated cells has been extensively studied, but the function of many of the genes identified is unknown. We have established an assay to test the ability of over-expressed transcripts to promote multiciliated cell differentiation in mouse embryonic tracheal explants. Overexpression data indicated that Fibronectin type 3 and ankyrin repeat domains 1 (Fank1) and JAZF zinc finger 1 (Jazf1) promoted multiciliated cell differentiation alone, and cooperatively with the canonical multiciliated cell transcription factor Foxj1. Moreover, knock-down of Fank1 or Jazf1 in adult mouse airway epithelial cultures demonstrated that these factors are both required for ciliated cell differentiation in vitro. This analysis identifies Fank1 and Jazf1 as novel regulators of multiciliated cell differentiation. Moreover, we show that they are likely to function downstream of IL6 signalling and upstream of Foxj1 activity in the process of ciliated cell differentiation. In addition, our in vitro explant assay provides a convenient method for preliminary investigation of over-expression phenotypes in the developing mouse airways. This article has an associated First Person interview with the first author of the paper. PMID:29661797

Vitronectin Expression in the Airways of Subjects with Asthma and Chronic Obstructive Pulmonary Disease

PubMed Central

Salazar-Peláez, Lina M.; Abraham, Thomas; Herrera, Ana M.; Correa, Mario A.; Ortega, Jorge E.; Paré, Peter D.; Seow, Chun Y.

2015-01-01

Vitronectin, a multifunctional glycoprotein, is involved in coagulation, inhibition of the formation of the membrane attack complex (MAC), cell adhesion and migration, wound healing, and tissue remodeling. The primary cellular source of vitronectin is hepatocytes; it is not known whether resident cells of airways produce vitronectin, even though the glycoprotein has been found in exhaled breath condensate and bronchoalveolar lavage from healthy subjects and patients with interstitial lung disease. It is also not known whether vitronectin expression is altered in subjects with asthma and COPD. In this study, bronchial tissue from 7 asthmatic, 10 COPD and 14 control subjects was obtained at autopsy and analyzed by immunohistochemistry to determine the percent area of submucosal glands occupied by vitronectin. In a separate set of experiments, quantitative colocalization analysis was performed on tracheobronchial tissue sections obtained from donor lungs (6 asthmatics, 4 COPD and 7 controls). Vitronectin RNA and protein expressions in bronchial surface epithelium were examined in 12 subjects who undertook diagnostic bronchoscopy. Vitronectin was found in the tracheobronchial epithelium from asthmatic, COPD, and control subjects, although its expression was significantly lower in the asthmatic group. Colocalization analysis of 3D confocal images indicates that vitronectin is expressed in the glandular serous epithelial cells and in respiratory surface epithelial cells other than goblet cells. Expression of the 65-kDa vitronectin isoform was lower in bronchial surface epithelium from the diseased subjects. The cause for the decreased vitronectin expression in asthma is not clear, however, the reduced concentration of vitronectin in the epithelial/submucosal layer of airways may be linked to airway remodeling. PMID:25768308

Lubiprostone targets prostanoid EP4 receptors in ovine airways

PubMed Central

Cuthbert, AW

2011-01-01

BACKGROUND AND PURPOSE Lubiprostone, a prostaglandin E1 derivative, is reported to activate ClC-2 chloride channels located in the apical membranes of a number of transporting epithelia. Lack of functioning CFTR chloride channels in epithelia is responsible for the genetic disease cystic fibrosis, therefore, surrogate channels that can operate independently of CFTR are of interest. This study explores the target receptor(s) for lubiprostone in airway epithelium. EXPERIMENTAL APPROACH All experiments were performed on the ventral tracheal epithelium of sheep. Epithelia were used to measure anion secretion from the apical surface as short circuit current or as fluid secretion from individual airway submucosal glands, using an optical method. KEY RESULTS The EP4 antagonists L-161982 and GW627368 inhibited short circuit current responses to lubiprostone, while EP1,2&3 receptor antagonists were without effect. Similarly, lubiprostone induced secretion in airway submucosal glands was inhibited by L-161982. L-161982 effectively competed with lubiprostone with a Kd value of 0.058 µM, close to its value for binding to human EP4 receptors (0.024 µM). The selective EP4 agonist L-902688 and lubiprostone behaved similarly with respect to EP4 receptor antagonists. Results of experiments with H89, a protein kinase A inhibitor, were consistent with lubiprostone acting through a Gs-protein coupled EP4 receptor/cAMP cascade. CONCLUSIONS AND IMPLICATIONS Lubiprostone-induced short-circuit currents and submucosal gland secretions were inhibited by selective EP4 receptor antagonists. The results suggest EP4 receptor activation by lubiprostone triggers cAMP production necessary for CFTR activation and the secretory responses, a possibility precluded in CF tissues. PMID:20883477

Changes in the Adult Vertebrate Auditory Sensory Epithelium After Trauma

PubMed Central

Oesterle, Elizabeth C.

2012-01-01

Auditory hair cells transduce sound vibrations into membrane potential changes, ultimately leading to changes in neuronal firing and sound perception. This review provides an overview of the characteristics and repair capabilities of traumatized auditory sensory epithelium in the adult vertebrate ear. Injured mammalian auditory epithelium repairs itself by forming permanent scars but is unable to regenerate replacement hair cells. In contrast, injured non-mammalian vertebrate ear generates replacement hair cells to restore hearing functions. Non-sensory support cells within the auditory epithelium play key roles in the repair processes. PMID:23178236

Critical role of actin-associated proteins in smooth muscle contraction, cell proliferation, airway hyperresponsiveness and airway remodeling.

PubMed

Tang, Dale D

2015-10-30

Asthma is characterized by airway hyperresponsiveness and airway remodeling, which are largely attributed to increased airway smooth muscle contractility and cell proliferation. It is known that both chemical and mechanical stimulation regulates smooth muscle contraction. Recent studies suggest that contractile activation and mechanical stretch induce actin cytoskeletal remodeling in smooth muscle. However, the mechanisms that control actin cytoskeletal reorganization are not completely elucidated. This review summarizes our current understanding regarding how actin-associated proteins may regulate remodeling of the actin cytoskeleton in airway smooth muscle. In particular, there is accumulating evidence to suggest that Abelson tyrosine kinase (Abl) plays a critical role in regulating airway smooth muscle contraction and cell proliferation in vitro, and airway hyperresponsiveness and remodeling in vivo. These studies indicate that Abl may be a novel target for the development of new therapy to treat asthma.

Airway Epithelial Barrier Dysfunction in Chronic Obstructive Pulmonary Disease: Role of Cigarette Smoke Exposure.

PubMed

Aghapour, Mahyar; Raee, Pourya; Moghaddam, Seyed Javad; Hiemstra, Pieter S; Heijink, Irene H

2018-02-01

The epithelial lining of the airway forms the first barrier against environmental insults, such as inhaled cigarette smoke, which is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). The barrier is formed by airway epithelial junctions, which are interconnected structures that restrict permeability to inhaled pathogens and environmental stressors. Destruction of the epithelial barrier not only exposes subepithelial layers to hazardous agents in the inspired air, but also alters the normal function of epithelial cells, which may eventually contribute to the development of COPD. Of note, disruption of epithelial junctions may lead to modulation of signaling pathways involved in differentiation, repair, and proinflammatory responses. Epithelial barrier dysfunction may be particularly relevant in COPD, where repeated injury by cigarette smoke exposure, pathogens, inflammatory mediators, and impaired epithelial regeneration may compromise the barrier function. In the current review, we discuss recent advances in understanding the mechanisms of barrier dysfunction in COPD, as well as the molecular mechanisms that underlie the impaired repair response of the injured epithelium in COPD and its inability to redifferentiate into a functionally intact epithelium.

Development of an airway mucus defect in the cystic fibrosis rat

PubMed Central

Birket, Susan E.; Davis, Joy M.; Fernandez, Courtney M.; Tuggle, Katherine L.; Oden, Ashley M.; Chu, Kengyeh K.; Tearney, Guillermo J.; Fanucchi, Michelle V.; Sorscher, Eric J.

2018-01-01

The mechanisms underlying the development and natural progression of the airway mucus defect in cystic fibrosis (CF) remain largely unclear. New animal models of CF, coupled with imaging using micro-optical coherence tomography, can lead to insights regarding these questions. The Cftr–/– (KO) rat allows for longitudinal examination of the development and progression of airway mucus abnormalities. The KO rat exhibits decreased periciliary depth, hyperacidic pH, and increased mucus solid content percentage; however, the transport rates and viscoelastic properties of the mucus are unaffected until the KO rat ages. Airway submucosal gland hypertrophy develops in the KO rat by 6 months of age. Only then does it induce increased mucus viscosity, collapse of the periciliary layer, and delayed mucociliary transport; stimulation of gland secretion potentiates this evolution. These findings could be reversed by bicarbonate repletion but not pH correction without counterion donation. These studies demonstrate that abnormal surface epithelium in CF does not cause delayed mucus transport in the absence of functional gland secretions. Furthermore, abnormal bicarbonate transport represents a specific target for restoring mucus clearance, independent of effects on periciliary collapse. Thus, mature airway secretions are required to manifest the CF defect primed by airway dehydration and bicarbonate deficiency. PMID:29321377

Allergen challenge-induced extravasation of plasma in mouse airways.

PubMed

Erjefält, J S; Andersson, P; Gustafsson, B; Korsgren, M; Sonmark, B; Persson, C G

1998-08-01

Mouse models are extensively used to study genetic and immunological mechanisms of potential importance to inflammatory airway diseases, e.g. asthma. However, the airway pathophysiology in allergic mice has received less attention. For example, plasma extravasation and the ensuing tissue-deposition of plasma proteins, which is a hallmark of inflammation, has not been examined in allergic mice. This study aims to examine the vascular permeability and the distribution of plasma proteins in mouse airways following exposure to allergen and serotonin. Extravasated plasma was quantified by a dual isotop technique using intravascular (131I-albumin) and extrasvascular (125I-albumin) plasma tracers. Histological visualization of fibrinogen and colloidal gold revealed the tissue distribution of extravasated plasma. Allergen aerosol exposure (3% OVA, 15min) of sensitized animals resulted in a marked plasma extravasation response in the trachea (P < 0.01) and the bronchi but not in the lung parenchyma. A similar extravasation response was induced by serotonin (P<0.001). Extravasating vessels (assessed by Monastral blue dye) were identified as intercartilaginous venules. Extravasated plasma abounded in the subepithelial tissue but was absent in the epithelium and airway lumen. The allergen-induced response was dose-dependently inhibited by iv administration of formoterol (P < 0.001), a vascular antipermeability agent. The present study demonstrates that serotonin and allergen challenge of sensitized mice increase airway venular permeability to cause transient extravasation and lamina propria distribution of plasma in the large airways. We suggest that the extravasation response is a useful measure of the intensity and the distribution of active inflammation

Effects of local nasal immunotherapy in allergic airway inflammation: Using urea denatured Dermatophagoides pteronyssinus

PubMed Central

Yu, Sheng-Jie; Liao, En-Chih; Tsai, Jaw-Ji

2015-01-01

Despite improvements in anti-allergy medication, the prevalence of allergic airway inflammation remains high, affecting up to 40% of the population worldwide. Allergen immunotherapy is effective for inducing tolerance but has the adverse effect of severe allergic reaction. This can be avoided by denaturing with urea. In this study, we demonstrated that the serum level of allergen-specific IgE in mice sensitized with native Dermatophagoides pteronyssinus (Der p) crude extract after receiving local nasal immunotherapy (LNIT) with urea-denatured Der p crude extract (DN-Dp) significantly decreased compared to that in the normal saline (NS) treatment group. Expressions of IL-4 were significantly reduced in lung tissues after treatment. Inflammation around the bronchial epithelium improved and airway hypersensitivity was down-regulated. LNIT with DN-Dp can down-regulate IL-1b, IL-6 and TNF-a expression and then decrease Der p-induced allergic airway inflammation. This therapeutic modality may be used as an alternative treatment for airway allergic diseases. PMID:25933184

Epithelium

MedlinePlus

The term "epithelium" refers to layers of cells that line hollow organs and glands. It is also those cells that make ... Kierszenbaum AL, Tres LL. Epithelium. In: Kierszenbaum AL, Tres LL, ... to Pathology . 4th ed. Philadelphia, PA: Elsevier Saunders; ...

Efficient delivery of RNA interference oligonucleotides to polarized airway epithelia in vitro

PubMed Central

Ramachandran, Shyam; Krishnamurthy, Sateesh; Jacobi, Ashley M.; Wohlford-Lenane, Christine; Behlke, Mark A.; Davidson, Beverly L.

2013-01-01

Polarized and pseudostratified primary airway epithelia present barriers that significantly reduce their transfection efficiency and the efficacy of RNA interference oligonucleotides. This creates an impediment in studies of the airway epithelium, diminishing the utility of loss-of-function as a research tool. Here we outline methods to introduce RNAi oligonucleotides into primary human and porcine airway epithelia grown at an air-liquid interface and difficult-to-transfect transformed epithelial cell lines grown on plastic. At the time of plating, we reverse transfect small-interfering RNA (siRNA), Dicer-substrate siRNA, or microRNA oligonucleotides into cells by use of lipid or peptide transfection reagents. Using this approach we achieve significant knockdown in vitro of hypoxanthine-guanine phosphoribosyltransferase, IL-8, and CFTR expression at the mRNA and protein levels in 1–3 days. We also attain significant reduction of secreted IL-8 in polarized primary pig airway epithelia 3 days posttransfection and inhibition of CFTR-mediated Cl− conductance in polarized air-liquid interface cultures of human airway epithelia 2 wk posttransfection. These results highlight an efficient means to deliver RNA interference reagents to airway epithelial cells and achieve significant knockdown of target gene expression and function. The ability to reliably conduct loss-of-function assays in polarized primary airway epithelia offers benefits to research in studies of epithelial cell homeostasis, candidate gene function, gene-based therapeutics, microRNA biology, and targeting the replication of respiratory viruses. PMID:23624792

Calcium-activated chloride channel TMEM16A modulates mucin secretion and airway smooth muscle contraction.

PubMed

Huang, Fen; Zhang, Hongkang; Wu, Meng; Yang, Huanghe; Kudo, Makoto; Peters, Christian J; Woodruff, Prescott G; Solberg, Owen D; Donne, Matthew L; Huang, Xiaozhu; Sheppard, Dean; Fahy, John V; Wolters, Paul J; Hogan, Brigid L M; Finkbeiner, Walter E; Li, Min; Jan, Yuh-Nung; Jan, Lily Yeh; Rock, Jason R

2012-10-02

Mucous cell hyperplasia and airway smooth muscle (ASM) hyperresponsiveness are hallmark features of inflammatory airway diseases, including asthma. Here, we show that the recently identified calcium-activated chloride channel (CaCC) TMEM16A is expressed in the adult airway surface epithelium and ASM. The epithelial expression is increased in asthmatics, particularly in secretory cells. Based on this and the proposed functions of CaCC, we hypothesized that TMEM16A inhibitors would negatively regulate both epithelial mucin secretion and ASM contraction. We used a high-throughput screen to identify small-molecule blockers of TMEM16A-CaCC channels. We show that inhibition of TMEM16A-CaCC significantly impairs mucus secretion in primary human airway surface epithelial cells. Furthermore, inhibition of TMEM16A-CaCC significantly reduces mouse and human ASM contraction in response to cholinergic agonists. TMEM16A-CaCC blockers, including those identified here, may positively impact multiple causes of asthma symptoms.

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.

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

Ozone-Induced Injury and Oxidative Stress in Bronchiolar Epithelium Are Associated with Altered Pulmonary Mechanics

PubMed Central

Sunil, Vasanthi R.

2013-01-01

In these studies, we analyzed the effects of ozone on bronchiolar epithelium. Exposure of rats to ozone (2 ppm, 3h) resulted in rapid (within 3h) and persistent (up to 72h) histological changes in the bronchiolar epithelium, including hypercellularity, loss of cilia, and necrotizing bronchiolitis. Perivascular edema and vascular congestion were also evident, along with a decrease in Clara cell secretory protein in bronchoalveolar lavage, which was maximal 24h post-exposure. Ozone also induced the appearance of 8-hydroxy-2′-deoxyguanosine, Ym1, and heme oxygenase-1 in the bronchiolar epithelium. This was associated with increased expression of cleaved caspase-9 and beclin-1, indicating initiation of apoptosis and autophagy. A rapid and persistent increase in galectin-3, a regulator of epithelial cell apoptosis, was also observed. Following ozone exposure (3–24h), increased expression of cyclooxygenase-2, inducible nitric oxide synthase, and arginase-1 was noted in bronchiolar epithelium. Ozone-induced injury and oxidative stress in bronchiolar epithelium were linked to methacholine-induced alterations in pulmonary mechanics. Thus, significant increases in lung resistance and elastance, along with decreases in lung compliance and end tidal volume, were observed at higher doses of methacholine. This indicates that ozone causes an increase in effective stiffness of the lung as a consequence of changes in the conducting airways. Collectively, these studies demonstrate that bronchiolar epithelium is highly susceptible to injury and oxidative stress induced by acute exposure to ozone; moreover, this is accompanied by altered lung functioning. PMID:23492811

Cyclosporine a inhibits apoptosis of rat gingival epithelium.

PubMed

Ma, Su; Liu, Peihong; Li, Yanwu; Hou, Lin; Chen, Li; Qin, Chunlin

2014-08-01

The use of cyclosporine A (CsA) induces hyperplasia of the gingival epithelium in a site-specific response manner, but the molecular mechanism via which the lesion occurs is unclear. The present research aims to investigate the site-specific effect of CsA on the apoptosis of gingival epithelium associated with gingival hyperplasia. Forty Wistar rats were divided into CsA-treated and non-treated groups. Paraffin-embedded sections of mandibular first molars were selected for hematoxylin and eosin staining, immunohistochemistry analyses of bcl-2 and caspase-3, and the staining of terminal deoxynucleotidyl transfer-mediated dUTP nick-end labeling (TUNEL). The area of the whole gingival epithelium and the length of rete pegs were measured, and the number of bcl-2- and caspase-3-positive cells in the longest rete peg were counted. The analysis of variance for factorial designs and Fisher least significant difference test for post hoc analysis were used to determine the significance levels. In CsA-treated rats, bcl-2 expression was significantly upregulated, whereas caspase-3 expression was downregulated, along with a reduced number of TUNEL-positive cells. The site-specific distribution of bcl-2 was consistent with the site-specific hyperplasia of the gingival epithelium in CsA-treated rats. CsA inhibited gingival epithelial apoptosis via the mitochondrial pathway and common pathway. The antiapoptotic protein bcl-2 might play a critical role in the pathogenesis of the site-specific hyperplasia of gingival epithelium induced by CsA. There were mechanistic differences in the regulation of apoptosis for cells in the attached gingival epithelium, free gingival epithelium, and junctional epithelium.

Receptor for advanced glycation end products and its ligand high-mobility group box-1 mediate allergic airway sensitization and airway inflammation.

PubMed

Ullah, Md Ashik; Loh, Zhixuan; Gan, Wan Jun; Zhang, Vivian; Yang, Huan; Li, Jian Hua; Yamamoto, Yasuhiko; Schmidt, Ann Marie; Armour, Carol L; Hughes, J Margaret; Phipps, Simon; Sukkar, Maria B

2014-08-01

The receptor for advanced glycation end products (RAGE) shares common ligands and signaling pathways with TLR4, a key mediator of house dust mite (Dermatophagoides pteronyssinus) (HDM) sensitization. We hypothesized that RAGE and its ligand high-mobility group box-1 (HMGB1) cooperate with TLR4 to mediate HDM sensitization. To determine the requirement for HMGB1 and RAGE, and their relationship with TLR4, in airway sensitization. TLR4(-/-), RAGE(-/-), and RAGE-TLR4(-/-) mice were intranasally exposed to HDM or cockroach (Blatella germanica) extracts, and features of allergic inflammation were measured during the sensitization or challenge phase. Anti-HMGB1 antibody and the IL-1 receptor antagonist Anakinra were used to inhibit HMGB1 and the IL-1 receptor, respectively. The magnitude of allergic airway inflammation in response to either HDM or cockroach sensitization and/or challenge was significantly reduced in the absence of RAGE but not further diminished in the absence of both RAGE and TLR4. HDM sensitization induced the release of HMGB1 from the airway epithelium in a biphasic manner, which corresponded to the sequential activation of TLR4 then RAGE. Release of HMGB1 in response to cockroach sensitization also was RAGE dependent. Significantly, HMGB1 release occurred downstream of TLR4-induced IL-1α, and upstream of IL-25 and IL-33 production. Adoptive transfer of HDM-pulsed RAGE(+/+)dendritic cells to RAGE(-/-) mice recapitulated the allergic responses after HDM challenge. Immunoneutralization of HMGB1 attenuated HDM-induced allergic airway inflammation. The HMGB1-RAGE axis mediates allergic airway sensitization and airway inflammation. Activation of this axis in response to different allergens acts to amplify the allergic inflammatory response, which exposes it as an attractive target for therapeutic intervention. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Airway hyper-responsiveness to neurokinin A and bradykinin following Mycoplasma pneumoniae infection associated with reduced epithelial neutral endopeptidase.

PubMed

Tamaoki, J; Chiyotani, A; Tagaya, E; Araake, M; Nagai, A

1998-09-01

To determine whether mycoplasma infection produces airway hyper-responsiveness to tachykinins and bradykinin and, if so, to elucidate the role of neutral endopeptidase (NEP), isolated hamster tracheal segments were studied under isometric conditions in vitro. Nasal inoculation with Mycoplasma pneumoniae potentiated contractile responses to neurokinin A and bradykinin, causing a leftward shift of the dose-response curves to a lower concentration by 1 log unit for each agonist, whereas there was no response with acetylcholine. Pretreatment of tissues with the NEP inhibitor phosphoramidon augmented neurokinin A- and bradykinin-induced contractions in saline-treated control tissues, but did not further potentiate the responsiveness in M. pneumoniae-infected tissues. NEP activity in the tracheal epithelium, but not in epithelium-denuded tissues, was decreased in infected animals. These results suggest that M. pneumoniae infection causes airway bronchoconstrictor hyper-responsiveness to neurokinin A and bradykinin and that this effect may be associated with an inhibition of epithelial NEP activity.

Caveolin-1: Functional Insights into Its Role in Muscarine- and Serotonin-Induced Smooth Muscle Constriction in Murine Airways

PubMed Central

Keshavarz, Maryam; Schwarz, Heike; Hartmann, Petra; Wiegand, Silke; Skill, Melanie; Althaus, Mike; Kummer, Wolfgang; Krasteva-Christ, Gabriela

2017-01-01

An increased bronchoconstrictor response is a hallmark in the progression of obstructive airway diseases. Acetylcholine and 5-hydroxytryptamine (5-HT, serotonin) are the major bronchoconstrictors. There is evidence that both cholinergic and serotonergic signaling in airway smooth muscle (ASM) involve caveolae. We hypothesized that caveolin-1 (cav-1), a structural protein of caveolae, plays an important regulatory role in ASM contraction. We analyzed airway contraction in different tracheal segments and extra- and intrapulmonary bronchi in cav-1 deficient (cav-1−/−) and wild-type mice using organ bath recordings and videomorphometry of methyl-beta-cyclodextrin (MCD) treated and non-treated precision-cut lung slices (PCLS). The presence of caveolae was investigated by electron microscopy. Receptor subtypes driving 5-HT-responses were studied by RT-PCR and videomorphometry after pharmacological inhibition with ketanserin. Cav-1 was present in tracheal epithelium and ASM. Muscarine induced a dose dependent contraction in all airway segments. A significantly higher Emax was observed in the caudal trachea. Although, caveolae abundancy was largely reduced in cav-1−/− mice, muscarine-induced airway contraction was maintained, albeit at diminished potency in the middle trachea, in the caudal trachea and in the bronchus without changes in the maximum efficacy. MCD-treatment of PLCS from cav-1−/− mice reduced cholinergic constriction by about 50%, indicating that cholesterol-rich plasma domains account for a substantial portion of the muscarine-induced bronchoconstriction. Notably, cav-1-deficiency fully abrogated 5-HT-induced contraction of extrapulmonary airways. In contrast, 5-HT-induced bronchoconstriction was fully maintained in cav-1-deficient intrapulmonary bronchi, but desensitization upon repetitive stimulation was enhanced. RT-PCR analysis revealed 5-HT1B, 5-HT2A, 5-HT6, and 5-HT7 receptors as the most prevalent subtypes in the airways. The 5-HT

Sensory neuropeptides and the human lower airways: present state and future directions.

PubMed

Joos, G F; Germonpre, P R; Kips, J C; Peleman, R A; Pauwels, R A

1994-06-01

The sensory neuropeptides, substance P and neurokinin A, are present in human airway nerves, beneath and within the epithelium, around blood vessels and submucosal glands, and within the bronchial smooth muscle layer. Studies on autopsy tissue, bronchoalveolar lavage and sputum suggest that in asthma the substance P content of the airways may be increased. Neurokinin A is a more potent bronchoconstrictor than substance P. Asthmatics are hyperresponsive to neurokinin A and substance P. The neuropeptide degrading enzyme, neutral endopeptidase is present in the airways and is involved in the degradation of endogenously released and exogenously administered substance P and neurokinin A, both in normal and asthmatic subjects. As for other indirect bronchoconstrictor stimuli, the effect of neurokinin A on airway calibre in asthmatics can be inhibited by pretreatment with nedocromil sodium. Evidence is accumulating, not only from studies in animals but also from experiments on human airways, that tachykinins may also cause mucus secretion and plasma extravasation. They also have important proinflammatory effects, such as the chemoattraction of eosinophils and neutrophils, the adhesion of neutrophils, and the stimulation of lymphocytes, macrophages and mast cells. The tachykinins interact with the targets on the airways by specific tachykinin receptors. The NK1 and the NK2 receptor have been characterized in human airways, both pharmacologically and by cloning. The NK2 receptor is responsible for the in vitro contraction of normal airways, whilst the NK1 receptor is responsible for most of the other airway effects. Because of their presence in the airways and because of their ability to mimic the various pathophysiological features of asthma, substance P and neurokinin A are presently considered as possible mediators of asthma. The present development of potent and selective tachykinin antagonists will allow us to further define the role of tachykinins in the pathogenesis

Airway compliance and dynamics explain the apparent discrepancy in length adaptation between intact airways and smooth muscle strips.

PubMed

Dowie, Jackson; Ansell, Thomas K; Noble, Peter B; Donovan, Graham M

2016-01-01

Length adaptation is a phenomenon observed in airway smooth muscle (ASM) wherein over time there is a shift in the length-tension curve. There is potential for length adaptation to play an important role in airway constriction and airway hyper-responsiveness in asthma. Recent results by Ansell et al., 2015 (JAP 2014 10.1152/japplphysiol.00724.2014) have cast doubt on this role by testing for length adaptation using an intact airway preparation, rather than strips of ASM. Using this technique they found no evidence for length adaptation in intact airways. Here we attempt to resolve this apparent discrepancy by constructing a minimal mathematical model of the intact airway, including ASM which follows the classic length-tension curve and undergoes length adaptation. This allows us to show that (1) no evidence of length adaptation should be expected in large, cartilaginous, intact airways; (2) even in highly compliant peripheral airways, or at more compliant regions of the pressure-volume curve of large airways, the effect of length adaptation would be modest and at best marginally detectable in intact airways; (3) the key parameters which control the appearance of length adaptation in intact airways are airway compliance and the relaxation timescale. The results of this mathematical simulation suggest that length adaptation observed at the level of the isolated ASM may not clearly manifest in the normal intact airway. Copyright © 2015 Elsevier B.V. All rights reserved.

Neurokinin-1 receptor mediates stress-exacerbated allergic airway inflammation and airway hyperresponsiveness in mice.

PubMed

Joachim, Ricarda A; Sagach, Viktoriya; Quarcoo, David; Dinh, Q Thai; Arck, Petra C; Klapp, Burghard F

2004-01-01

A wealth of clinical observation has suggested that stress and asthma morbidity are associated. We have previously established a mouse model of stress-exacerbated allergic airway inflammation, which reflects major clinical findings. The aim of the current study was to investigate the role of the neurokinin- (NK-)1 receptor in the mediation of stress effects in allergic airway inflammation. BALB/c mice were systemically sensitized with ovalbumin (OVA) on assay days 1, 14, and 21 and repeatedly challenged with OVA aerosol on days 26 and 27. Sound stress was applied to the animals for 24 hours, starting with the first airway challenge. Additionally, one group of stressed and one group of nonstressed mice received the highly specific NK-1 receptor antagonist RP 67580. Bronchoalveolar lavage fluid was obtained, and cell numbers and differentiation were determined. Airway hyperreactivity was measured in vitro by electrical field stimulation of tracheal smooth-muscle elements. Application of stress in sensitized and challenged animals resulted in a significant increase in leukocyte number in the bronchoalveolar lavage fluid. Furthermore, stressed animals showed enhanced airway reactivity. The increase of inflammatory cells and airway reactivity was blocked by treatment of animals with the NK-1 receptor antagonist. These data indicate that the NK-1 receptor plays an important role in mediating stress effects in allergen-induced airway inflammation.

Endoscopic diode-laser applications in airway surgery

NASA Astrophysics Data System (ADS)

Pankratov, Michail M.; Wang, Zhi; Rebeiz, Elie E.; Perrault, Donald F., Jr.; Shapshay, Stanley M.; Gleich, Lyon L.

1994-09-01

A technique was developed to secure small mucosal grafts onto the airway wound with fibrin/albumin tissue adhesive mixed with ICG dye and irradiated with a 810 nm diode laser. An in vitro study of the tensile strength produced strong mucosal soldering which was adequate to fix grafts in place. In vivo studies showed that wounds with mucosal grafts were completely covered by regenerated squamous cells in 1 week and by ciliated epithelium in 2 weeks. Excellent healing was observed at 6 and 14 days postoperatively and the histology at 28 days found normal epithelium over the vocal cord lesion. This soldering technique is a less traumatic treatment for patients with extensive lesions of the larynx of various origin. Diode laser soldering with ICG-doped fibrin tissue adhesive was evaluated in tracheal anastomosis as a substitute for absorbable sutures. In vitro studies demonstrated strong anastomoses with minimal tissue damage. In vivo animal study showed that these anastomoses had less fibrosis and tissue damage than control animals repaired with sutures only.

Differentiated human airway organoids to assess infectivity of emerging influenza virus.

PubMed

Zhou, Jie; Li, Cun; Sachs, Norman; Chiu, Man Chun; Wong, Bosco Ho-Yin; Chu, Hin; Poon, Vincent Kwok-Man; Wang, Dong; Zhao, Xiaoyu; Wen, Lei; Song, Wenjun; Yuan, Shuofeng; Wong, Kenneth Kak-Yuen; Chan, Jasper Fuk-Woo; To, Kelvin Kai-Wang; Chen, Honglin; Clevers, Hans; Yuen, Kwok-Yung

2018-06-26

Novel reassortant avian influenza H7N9 virus and pandemic 2009 H1N1 (H1N1pdm) virus cause human infections, while avian H7N2 and swine H1N1 virus mainly infect birds and pigs, respectively. There is no robust in vitro model for assessing the infectivity of emerging viruses in humans. Based on a recently established method, we generated long-term expanding 3D human airway organoids which accommodate four types of airway epithelial cells: ciliated, goblet, club, and basal cells. We report differentiation conditions which increase ciliated cell numbers to a nearly physiological level with synchronously beating cilia readily discernible in every organoid. In addition, the differentiation conditions induce elevated levels of serine proteases, which are essential for productive infection of human influenza viruses and low-pathogenic avian influenza viruses. We also established improved 2D monolayer culture conditions for the differentiated airway organoids. To demonstrate the ability of differentiated airway organoids to identify human-infective virus, 3D and 2D differentiated airway organoids are applied to evaluate two pairs of viruses with known distinct infectivity in humans, H7N9/Ah versus H7N2 and H1N1pdm versus an H1N1 strain isolated from swine (H1N1sw). The human-infective H7N9/Ah virus replicated more robustly than the poorly human-infective H7N2 virus; the highly human-infective H1N1pdm virus replicated to a higher titer than the counterpart H1N1sw. Collectively, we developed differentiated human airway organoids which can morphologically and functionally simulate human airway epithelium. These differentiated airway organoids can be applied for rapid assessment of the infectivity of emerging respiratory viruses to human. Copyright © 2018 the Author(s). Published by PNAS.

Analysis of Cell Turnover in the Bronchiolar Epithelium Through the Normal Aging Process.

PubMed

Ortega-Martínez, Marta; Rodríguez-Flores, Laura E; Ancer-Arellano, Adriana; Cerda-Flores, Ricardo M; de-la-Garza-González, Carlos; Ancer-Rodríguez, Jesús; Jaramillo-Rangel, Gilberto

2016-08-01

Aging is associated with changes in the lung that leads to a decrease in its function. Alterations in structure and function in the small airways are well recognized in chronic lung diseases. The aim of this study was the assessment of cell turnover in the bronchiolar epithelium of mouse through the normal aging process. Lungs from CD1 mice at the age of 2, 6, 12, 18, or 24 months were fixed in neutral-buffered formalin and paraffin-embedded. Proliferating cell nuclear antigen was examined by immunohistochemistry. Apoptosis was analyzed by in situ end-labeling of fragmented DNA. Epithelial dimensions were analyzed by morphometry. The 2-month-old mice showed significantly higher number of proliferating cells when compared with mice at all other age groups. The number of apoptotic cells in mice at 24 months of age was significantly greater than in mice at all other age groups. Thus, the number of epithelial cells decreased as the age of the subject increased. We also found reductions in both area and height of the bronchiolar epithelium in mice at 18 and 24 months of age. We found a decrease in the total number of epithelial cells in the aged mice, which was accompanied by a thinning of the epithelium. These changes reflect a dysregulated tissue regeneration process in the bronchiolar epithelium that might predispose to respiratory diseases in elderly subjects.

Airway Obstruction Due to Bronchial Vascular Injury after Sulfur Mustard Analog Inhalation

PubMed Central

Veress, Livia A.; O'Neill, Heidi C.; Hendry-Hofer, Tara B.; Loader, Joan E.; Rancourt, Raymond C.; White, Carl W.

2010-01-01

Rationale: Sulfur mustard (SM) is a frequently used chemical warfare agent, even in modern history. SM inhalation causes significant respiratory tract injury, with early complications due to airway obstructive bronchial casts, akin to those seen after smoke inhalation and in single-ventricle physiology. This process with SM is poorly understood because animal models are unavailable. Objectives: To develop a rat inhalation model for airway obstruction with the SM analog 2-chloroethyl ethyl sulfide (CEES), and to investigate the pathogenesis of bronchial cast formation. Methods: Adult rats were exposed to 0, 5, or 7.5% CEES in ethanol via nose-only aerosol inhalation (15 min). Airway microdissection and confocal microscopy were used to assess cast formation (4 and 18 h after exposure). Bronchoalveolar lavage fluid (BALF) retrieval and intravascular dye injection were done to evaluate vascular permeability. Measurements and Main Results: Bronchial casts, composed of abundant fibrin and lacking mucus, occluded dependent lobar bronchi within 18 hours of CEES exposure. BALF contained elevated concentrations of IgM, protein, and fibrin. Accumulation of fibrin-rich fluid in peribronchovascular regions (4 h) preceded cast formation. Monastral blue dye leakage identified bronchial vessels as the site of leakage. Conclusions: After CEES inhalation, increased permeability from damaged bronchial vessels underlying damaged airway epithelium leads to the appearance of plasma proteins in both peribronchovascular regions and BALF. The subsequent formation of fibrin-rich casts within the airways then leads to airways obstruction, causing significant morbidity and mortality acutely after exposure. PMID:20639443

Matrilysin (Matrix Metalloproteinase-7) Mediates E-Cadherin Ectodomain Shedding in Injured Lung Epithelium

PubMed Central

McGuire, John K.; Li, Qinglang; Parks, William C.

2003-01-01

Matrilysin (matrix metalloproteinase-7) is highly expressed in lungs of patients with pulmonary fibrosis and other conditions associated with airway and alveolar injury. Although matrilysin is required for closure of epithelial wounds ex vivo, the mechanism of its action in repair is unknown. We demonstrate that matrilysin mediates shedding of E-cadherin ectodomain from injured lung epithelium both in vitro and in vivo. In alveolar-like epithelial cells, transfection of activated matrilysin resulted in shedding of E-cadherin and accelerated cell migration. In vivo, matrilysin co-localized with E-cadherin at the basolateral surfaces of migrating tracheal epithelium, and the reorganization of cell-cell junctions seen in wild-type injured tissue was absent in matrilysin-null samples. E-cadherin ectodomain was shed into the bronchoalveolar lavage fluid of bleomycin-injured wild-type mice, but was not shed in matrilysin-null mice. These findings identify E-cadherin as a novel substrate for matrilysin and indicate that shedding of E-cadherin ectodomain is required for epithelial repair. PMID:12759241

Pro-inflammatory mediators disrupt glucose homeostasis in airway surface liquid ‡

PubMed Central

Garnett, James P.; Nguyen, Trang T.; Moffatt, James D.; Pelham, Elizabeth R.; Kalsi, Kameljit K.; Baker, Emma H.; Baines, Deborah L.

2012-01-01

The glucose concentration of the airway surface liquid (ASL) is much lower than blood and is tightly regulated by the airway epithelium. ASL glucose is elevated in patients with viral colds, cystic fibrosis, chronic obstructive pulmonary disease (COPD) and asthma. Elevated ASL glucose is also associated with increased incidence of respiratory infection. However, the mechanism by which ASL glucose increases under inflammatory conditions is unknown. The aim of this study was to investigate the effect of pro-inflammatory mediators (PIMs) on the mechanisms governing airway glucose homeostasis in polarised monolayers of human airway (H441) and primary human bronchial epithelial (HBE) cells. Monolayers were treated with TNF-α, IFN-γ and LPS over 72 hours. PIM treatment led to increase in ASL glucose concentration and significantly reduced H441 and HBE transepithelial resistance (RT). This decline in RT was associated with an increase in paracellular permeability of glucose. Similar enhanced rates of paracellular glucose flux were also observed across excised trachea from LPS-treated mice. Interestingly, PIMs enhanced glucose uptake across the apical, but not the basolateral, membrane of H441 and HBE monolayers. This increase was predominantly via phloretin-sensitive GLUT-mediated uptake, which coincided with an increase in GLUT2 and GLUT10 abundance. In conclusion, exposure of airway epithelial monolayers to PIMs results in increased paracellular glucose flux, and apical GLUT-mediated glucose uptake. However uptake was insufficient to limit glucose accumulation in ASL. These data provide for the first time, a mechanism to support clinical findings that ASL glucose concentration is increased in patients with airway inflammation. PMID:22623330

Human Rhinovirus Infection of Epithelial Cells Modulates Airway Smooth Muscle Migration.

PubMed

Shariff, Sami; Shelfoon, Christopher; Holden, Neil S; Traves, Suzanne L; Wiehler, Shahina; Kooi, Cora; Proud, David; Leigh, Richard

2017-06-01

Airway remodeling, a characteristic feature of asthma, begins in early life. Recurrent human rhinovirus (HRV) infections are a potential inciting stimulus for remodeling. One component of airway remodeling is an increase in airway smooth muscle cell (ASMC) mass with a greater proximity of the ASMCs to the airway epithelium. We asked whether human bronchial epithelial cells infected with HRV produced mediators that are chemotactic for ASMCs. ASMC migration was investigated using the modified Boyden Chamber and the xCELLigence Real-Time Cell Analyzer (ACEA Biosciences Inc., San Diego, CA). Multiplex bead analysis was used to measure HRV-induced epithelial chemokine release. The chemotactic effects of CCL5, CXCL8, and CXCL10 were also examined. Supernatants from HRV-infected epithelial cells caused ASMC chemotaxis. Pretreatment of ASMCs with pertussis toxin abrogated chemotaxis, as did treatment with formoterol, forskolin, or 8-bromo-cAMP. CCL5, CXCL8, and CXCL10 were the most up-regulated chemokines produced by HRV-infected airway epithelial cells. When recombinant CCL5, CXCL8, and CXCL10 were used at levels found in epithelial supernatants, they induced ASMC chemotaxis similar to that seen with epithelial cell supernatants. When examined individually, CCL5 was the most effective chemokine in causing ASMC migration, and treatment of supernatant from HRV-infected epithelial cells with anti-CCL5 antibodies significantly attenuated ASMC migration. These findings suggest that HRV-induced CCL5 can induce ASMC chemotaxis and thus may contribute to the pathogenesis of airway remodeling in patients with asthma.

Aspergillus fumigatus Infection-Induced Neutrophil Recruitment and Location in the Conducting Airway of Immunocompetent, Neutropenic, and Immunosuppressed Mice.

PubMed

Shevchenko, Marina A; Bogorodskiy, Andrey O; Troyanova, Natalia I; Servuli, Ekaterina A; Bolkhovitina, Elena L; Büldt, Georg; Fahlke, Christoph; Gordeliy, Valentin I; Gensch, Thomas; Borshchevskiy, Valentin I; Sapozhnikov, Alexander M

2018-01-01

Susceptibility to fungal infection is commonly associated with impaired neutrophil responses. To study the mechanisms underlying this association, we investigated neutrophil recruitment to the conducting airway wall after Aspergillus fumigatus conidium inhalation in mouse models of drug-induced immunosuppression and antibody-mediated neutrophil depletion (neutropenia) by performing three-dimensional confocal laser-scanning microscopy of whole-mount primary bronchus specimens. Actin staining enabled visualization of the epithelial and smooth muscle layers that mark the airway wall. Gr-1 + or Ly6G + neutrophils located between the epithelium and smooth muscles were considered airway wall neutrophils. The number of airway wall neutrophils for immunocompetent, immunosuppressed, and neutropenic mice before and 6 h after A. fumigatus infection were analyzed and compared. Our results show that the number of conducting airway wall neutrophils in immunocompetent mice significantly increased upon inflammation, while a dramatic reduction in this number was observed following immunosuppression and neutropenia. Interestingly, a slight increase in the infiltration of neutrophils into the airway wall was detected as a result of infection, even in immunosuppressed and neutropenic mice. Taken together, these data indicate that neutrophils are present in intact conducting airway walls and the number elevates upon A. fumigatus infection. Conducting airway wall neutrophils are affected by both neutropenia and immunosuppression.

Aspergillus fumigatus Infection-Induced Neutrophil Recruitment and Location in the Conducting Airway of Immunocompetent, Neutropenic, and Immunosuppressed Mice

PubMed Central

Bogorodskiy, Andrey O.; Troyanova, Natalia I.; Servuli, Ekaterina A.; Bolkhovitina, Elena L.; Büldt, Georg; Fahlke, Christoph; Gordeliy, Valentin I.; Gensch, Thomas; Sapozhnikov, Alexander M.

2018-01-01

Susceptibility to fungal infection is commonly associated with impaired neutrophil responses. To study the mechanisms underlying this association, we investigated neutrophil recruitment to the conducting airway wall after Aspergillus fumigatus conidium inhalation in mouse models of drug-induced immunosuppression and antibody-mediated neutrophil depletion (neutropenia) by performing three-dimensional confocal laser-scanning microscopy of whole-mount primary bronchus specimens. Actin staining enabled visualization of the epithelial and smooth muscle layers that mark the airway wall. Gr-1+ or Ly6G+ neutrophils located between the epithelium and smooth muscles were considered airway wall neutrophils. The number of airway wall neutrophils for immunocompetent, immunosuppressed, and neutropenic mice before and 6 h after A. fumigatus infection were analyzed and compared. Our results show that the number of conducting airway wall neutrophils in immunocompetent mice significantly increased upon inflammation, while a dramatic reduction in this number was observed following immunosuppression and neutropenia. Interestingly, a slight increase in the infiltration of neutrophils into the airway wall was detected as a result of infection, even in immunosuppressed and neutropenic mice. Taken together, these data indicate that neutrophils are present in intact conducting airway walls and the number elevates upon A. fumigatus infection. Conducting airway wall neutrophils are affected by both neutropenia and immunosuppression. PMID:29577051

Urban particulate matter increases human airway epithelial cell IL-1β secretion following scratch wounding and H1N1 influenza A exposure in vitro.

PubMed

Hirota, Jeremy A; Marchant, David J; Singhera, Gurpreet K; Moheimani, Fatemeh; Dorscheid, Delbert R; Carlsten, Christopher; Sin, Don; Knight, Darryl

2015-01-01

The airway epithelium represents the first line of defense against inhaled environmental insults including air pollution, allergens, and viruses. Epidemiological and experimental evidence has suggested a link between air pollution exposure and the symptoms associated with respiratory viral infections. We hypothesized that multiple insults integrated by the airway epithelium NLRP3 inflammasome would result in augmented IL-1β release and downstream cytokine production following respiratory virus exposure. We performed in vitro experiments with a human airway epithelial cell line (HBEC-6KT) that involved isolated or combination exposure to mechanical wounding, PM10, house dust mite, influenza A virus, and respiratory syncytial virus. We performed confocal microscopy to image the localization of PM10 within HBEC-6KT and ELISAs to measure soluble mediator production. Airway epithelial cells secrete IL-1β in a time-dependent fashion that is associated with internalization of PM10 particles. PM10 exposure primes human airway epithelial cells to subsequent models of cell damage and influenza A virus exposure. Prior PM10 exposure had no effect on IL-1β responses to RSV exposure. Finally we demonstrate that PM10-priming of human airway epithelial cell IL-1β and GM-CSF responses to influenza A exposure are sensitive to NLRP3 inflammasome inhibition. Our results suggest the NLRP3 inflammasome may contribute to exaggerated immune responses to influenza A virus following periods of poor air quality. Intervention strategies targeting the NLRP3 inflammasome in at risk individuals may restrict poor air quality priming of mucosal immune responses that result from subsequent viral exposures.

Expression of protease activated receptor-2 (PAR-2) in central airways of smokers and non-smokers

PubMed Central

Miotto, D; Hollenberg, M; Bunnett, N; Papi, A; Braccioni, F; Boschetto, P; Rea, F; Zuin, A; Geppetti, P; Saetta, M; Maestrelli, P; Fabbri, L; Mapp, C

2002-01-01

Background: Protease activated receptor-2 (PAR-2) is a transmembrane G protein coupled receptor preferentially activated by trypsin and tryptase. The protease activated receptors play an important role in most components of injury responses including cell proliferation, migration, matrix remodelling, and inflammation. Cigarette smoking causes an inflammatory process in the central airways, peripheral airways, lung parenchyma, and adventitia of pulmonary arteries. Methods: To quantify the expression of PAR-2 in the central airways of smokers and non-smokers, surgical specimens obtained from 30 subjects undergoing lung resection for localised pulmonary lesions (24 with a history of cigarette smoking and six non-smoking control subjects) were examined. Central airways were immunostained with an antiserum specific for PAR-2 and PAR-2 expression was quantified using light microscopy and image analysis. Results: PAR-2 expression was found in bronchial smooth muscle, epithelium, glands, and in the endothelium and smooth muscle of bronchial vessels. PAR-2 expression was similar in the central airways of smokers and non-smokers. When smokers were divided according to the presence of symptoms of chronic bronchitis and chronic airflow limitation, PAR-2 expression was increased in smooth muscle (median 3.8 (interquartile range 2.9–5.8) and 1.4 (1.07–3.4) respectively); glands (33.3 (18.2–43.8) and 16.2 (11.5–22.2), respectively); and bronchial vessels (54.2 (48.7–56.8) and 40.0 (36–40.4), respectively) of smokers with symptoms of chronic bronchitis with normal lung function compared with smokers with chronic airflow limitation (COPD), but the increase was statistically significant (p<0.005) only for bronchial vessels. Conclusions: PAR-2 is present in bronchial smooth muscle, glands, and bronchial vessels of both smokers and non-smokers. An increased expression of PAR-2 was found in bronchial vessels of patients with bronchitis compared with those with COPD. PMID

Directional secretory response of double stranded RNA-induced thymic stromal lymphopoetin (TSLP) and CCL11/eotaxin-1 in human asthmatic airways.

PubMed

Nino, Gustavo; Huseni, Shehlanoor; Perez, Geovanny F; Pancham, Krishna; Mubeen, Humaira; Abbasi, Aleeza; Wang, Justin; Eng, Stephen; Colberg-Poley, Anamaris M; Pillai, Dinesh K; Rose, Mary C

2014-01-01

Thymic stromal lymphoproetin (TSLP) is a cytokine secreted by the airway epithelium in response to respiratory viruses and it is known to promote allergic Th2 responses in asthma. This study investigated whether virally-induced secretion of TSLP is directional in nature (apical vs. basolateral) and/or if there are TSLP-mediated effects occurring at both sides of the bronchial epithelial barrier in the asthmatic state. Primary human bronchial epithelial cells (HBEC) from control (n = 3) and asthmatic (n = 3) donors were differentiated into polarized respiratory tract epithelium under air-liquid interface (ALI) conditions and treated apically with dsRNA (viral surrogate) or TSLP. Sub-epithelial effects of TSLP were examined in human airway smooth muscle cells (HASMC) from normal (n = 3) and asthmatic (n = 3) donors. Clinical experiments examined nasal airway secretions obtained from asthmatic children during naturally occurring rhinovirus-induced exacerbations (n = 20) vs. non-asthmatic uninfected controls (n = 20). Protein levels of TSLP, CCL11/eotaxin-1, CCL17/TARC, CCL22/MDC, TNF-α and CXCL8 were determined with a multiplex magnetic bead assay. Our data demonstrate that: 1) Asthmatic HBEC exhibit an exaggerated apical, but not basal, secretion of TSLP after dsRNA exposure; 2) TSLP exposure induces unidirectional (apical) secretion of CCL11/eotaxin-1 in asthmatic HBEC and enhanced CCL11/eotaxin-1 secretion in asthmatic HASMC; 3) Rhinovirus-induced asthma exacerbations in children are associated with in vivo airway secretion of TSLP and CCL11/eotaxin-1. There are virally-induced TSLP-driven secretory immune responses at both sides of the bronchial epithelial barrier characterized by enhanced CCL11/eotaxin-1 secretion in asthmatic airways. These results suggest a new model of TSLP-mediated eosinophilic responses in the asthmatic airway during viral-induced exacerbations.

Directional Secretory Response of Double Stranded RNA-Induced Thymic Stromal Lymphopoetin (TSLP) and CCL11/Eotaxin-1 in Human Asthmatic Airways

PubMed Central

Perez, Geovanny F.; Pancham, Krishna; Mubeen, Humaira; Abbasi, Aleeza; Wang, Justin; Eng, Stephen; Colberg-Poley, Anamaris M.; Pillai, Dinesh K.; Rose, Mary C.

2014-01-01

Background Thymic stromal lymphoproetin (TSLP) is a cytokine secreted by the airway epithelium in response to respiratory viruses and it is known to promote allergic Th2 responses in asthma. This study investigated whether virally-induced secretion of TSLP is directional in nature (apical vs. basolateral) and/or if there are TSLP-mediated effects occurring at both sides of the bronchial epithelial barrier in the asthmatic state. Methods Primary human bronchial epithelial cells (HBEC) from control (n = 3) and asthmatic (n = 3) donors were differentiated into polarized respiratory tract epithelium under air-liquid interface (ALI) conditions and treated apically with dsRNA (viral surrogate) or TSLP. Sub-epithelial effects of TSLP were examined in human airway smooth muscle cells (HASMC) from normal (n = 3) and asthmatic (n = 3) donors. Clinical experiments examined nasal airway secretions obtained from asthmatic children during naturally occurring rhinovirus-induced exacerbations (n = 20) vs. non-asthmatic uninfected controls (n = 20). Protein levels of TSLP, CCL11/eotaxin-1, CCL17/TARC, CCL22/MDC, TNF-α and CXCL8 were determined with a multiplex magnetic bead assay. Results Our data demonstrate that: 1) Asthmatic HBEC exhibit an exaggerated apical, but not basal, secretion of TSLP after dsRNA exposure; 2) TSLP exposure induces unidirectional (apical) secretion of CCL11/eotaxin-1 in asthmatic HBEC and enhanced CCL11/eotaxin-1 secretion in asthmatic HASMC; 3) Rhinovirus-induced asthma exacerbations in children are associated with in vivo airway secretion of TSLP and CCL11/eotaxin-1. Conclusions There are virally-induced TSLP-driven secretory immune responses at both sides of the bronchial epithelial barrier characterized by enhanced CCL11/eotaxin-1 secretion in asthmatic airways. These results suggest a new model of TSLP-mediated eosinophilic responses in the asthmatic airway during viral-induced exacerbations. PMID:25546419

Loop diuretics inhibit cholinergic and noncholinergic nerves in guinea pig airways.

PubMed

Elwood, W; Lötvall, J O; Barnes, P J; Chung, K F

1991-06-01

Furosemide, a loop diuretic, is known to inhibit the response to a variety of indirect bronchial challenges in humans but does not inhibit bronchoconstriction induced by inhaled methacholine or histamine. We have investigated the effects of the two loop diuretics, furosemide (10(-6) to 10(-3) M) and bumetanide (10(-7) to 10(-4) M), on airway smooth muscle contraction in vitro induced by electrical field stimulation (EFS), or exogenously applied acetylcholine (ACh) or substance P (SP) in guinea pig tracheal and bronchial smooth muscle strips pretreated with indomethacin (10(-5) M) and propranolol (10(-6) M). Both furosemide and bumetanide caused a concentration-dependent inhibition of cholinergically mediated neural contraction in the trachea. The effect of furosemide was not influenced by the presence of airway epithelium. Furthermore, both furosemide and bumetanide inhibited in a concentration-dependent fashion nonadrenergic, noncholinergic (NANC) contraction induced by electrical field stimulation of bronchi pretreated with atropine (10(-5) M). Neither drug at the highest concentration inhibited the responses to exogenous acetylcholine (10(-8) to 10(-2) M) or substance P (10(-9) to 10(-5) M). Thus loop diuretics inhibit the neurally induced contraction of guinea pig airways without a direct effect on airway smooth muscle. We conclude that loop diuretics inhibit both cholinergic and excitatory NANC neurotransmission in guinea pig airways and that this effect may be related to their inhibitory effects on the sodium-potassium-chloride cotransporter.

Chloride and potassium channels in cystic fibrosis airway epithelia

NASA Astrophysics Data System (ADS)

Welsh, Michael J.; Liedtke, Carole M.

1986-07-01

Cystic fibrosis, the most common lethal genetic disease in Caucasians, is characterized by a decreased permeability in sweat gland duct and airway epithelia. In sweat duct epithelium, a decreased Cl- permeability accounts for the abnormally increased salt content of sweat1. In airway epithelia a decreased Cl- permeability, and possibly increased sodium absorption, may account for the abnormal respiratory tract fluid2,3. The Cl- impermeability has been localized to the apical membrane of cystic fibrosis airway epithelial cells4. The finding that hormonally regulated Cl- channels make the apical membrane Cl- permeable in normal airway epithelial cells5 suggested abnormal Cl- channel function in cystic fibrosis. Here we report that excised, cell-free patches of membrane from cystic fibrosis epithelial cells contain Cl- channels that have the same conductive properties as Cl- channels from normal cells. However, Cl- channels from cystic fibrosis cells did not open when they were attached to the cell. These findings suggest defective regulation of Cl- channels in cystic fibrosis epithelia; to begin to address this issue, we performed two studies. First, we found that isoprenaline, which stimulates Cl- secretion, increases cellular levels of cyclic AMP in a similar manner in cystic fibrosis and non-cystic fibrosis epithelial cells. Second, we show that adrenergic agonists open calcium-activated potassium channels, indirectly suggesting that calcium-dependent stimulus-response coupling is intact in cystic fibrosis. These data suggest defective regulation of Cl- channels at a site distal to cAMP accumulation.

Dual p38/JNK Mitogen Activated Protein Kinase Inhibitors Prevent Ozone-Induced Airway Hyperreactivity in Guinea Pigs

PubMed Central

Verhein, Kirsten C.; Salituro, Francesco G.; Ledeboer, Mark W.; Fryer, Allison D.; Jacoby, David B.

2013-01-01

Ozone exposure causes airway hyperreactivity and increases hospitalizations resulting from pulmonary complications. Ozone reacts with the epithelial lining fluid and airway epithelium to produce reactive oxygen species and lipid peroxidation products, which then activate cell signaling pathways, including the mitogen activated protein kinase (MAPK) pathway. Both p38 and c-Jun NH2 terminal kinase (JNK) are MAPK family members that are activated by cellular stress and inflammation. To test the contribution of both p38 and JNK MAPK to ozone-induced airway hyperreactivity, guinea pigs were pretreated with dual p38 and JNK MAPK inhibitors (30 mg/kg, ip) 60 minutes before exposure to 2 ppm ozone or filtered air for 4 hours. One day later airway reactivity was measured in anesthetized animals. Ozone caused airway hyperreactivity one day post-exposure, and blocking p38 and JNK MAPK completely prevented ozone-induced airway hyperreactivity. Blocking p38 and JNK MAPK also suppressed parasympathetic nerve activity in air exposed animals, suggesting p38 and JNK MAPK contribute to acetylcholine release by airway parasympathetic nerves. Ozone inhibited neuronal M2 muscarinic receptors and blocking both p38 and JNK prevented M2 receptor dysfunction. Neutrophil influx into bronchoalveolar lavage was not affected by MAPK inhibitors. Thus p38 and JNK MAPK mediate ozone-induced airway hyperreactivity through multiple mechanisms including prevention of neuronal M2 receptor dysfunction. PMID:24058677

Asthmatic bronchial epithelium activated by the proteolytic allergen Der p 1 increases selective dendritic cell recruitment.

PubMed

Pichavant, Muriel; Charbonnier, Anne-Sophie; Taront, Solenne; Brichet, Anne; Wallaert, Benoît; Pestel, Joel; Tonnel, André-Bernard; Gosset, Philippe

2005-04-01

Airway dendritic cells (DCs) are crucial for allergen-induced sensitization and inflammation in allergic asthma. After allergen challenge, an increased number of DCs is observed in airway epithelium from patients with allergy. Because Der p 1, a cysteine protease allergen from Dermatophagoides pteronyssinus , induces chemokine production by bronchial epithelial cells (BECs), the purpose of this investigation was to evaluate the capacity of BEC exposed to Der p 1 to recruit DCs. Chemotactic activity of BEAS-2B, a bronchial epithelial cell line, and BECs from nonatopic controls and patients with allergic asthma was evaluated on the migration of precursors, immature and mature monocyte-derived DCs (MDDCs), and CD34 + -derived Langerhans cells (LCs). C-C chemokine ligand (CCL)-2, CCL5, and C-X-C chemokine ligand 10 production by BEAS-2B and BEC was increased after Der p 1 exposure, whereas the proenzyme proDer p 1 devoid of enzymatic activity had no effect. Der p 1 stimulation of BEAS-2B and BEC from both groups increased significantly the recruitment of MDDC precursors, depending on CCL2, CCL5, and C-X-C chemokine ligand 10 production. In a reconstituted polarized epithelium, apical application of Der p 1 enhanced MDDC precursor migration into the epithelial layer. Moreover, Der p 1 stimulation of BEC from patients with asthma but not from controls increased the migration of LC precursors, mainly dependent on CCL20 secretion. No migration of immature and mature DCs was observed. These data confirmed that BECs participate in the homeostasis of the DC network present within the bronchial epithelium through the secretion of chemokines. In allergic asthma, upregulation of CCL20 production induced LC recruitment, the role of which remains to be determined.

The junctional epithelium originates from the odontogenic epithelium of an erupted tooth.

PubMed

Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

2014-05-02

The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period.

Microfluidic lung airway-on-a-chip with arrayable suspended gels for studying epithelial and smooth muscle cell interactions.

PubMed

Humayun, Mouhita; Chow, Chung-Wai; Young, Edmond W K

2018-05-01

Chronic lung diseases (CLDs) are regulated by complex interactions between many different cell types residing in lung airway tissues. Specifically, interactions between airway epithelial cells (ECs) and airway smooth muscle cells (SMCs) have been shown in part to play major roles in the pathogenesis of CLDs, but the underlying molecular mechanisms are not well understood. To advance our understanding of lung pathophysiology and accelerate drug development processes, new innovative in vitro tissue models are needed that can reconstitute the complex in vivo microenvironment of human lung tissues. Organ-on-a-chip technologies have recently made significant strides in recapitulating physiological properties of in vivo lung tissue microenvironments. However, novel advancements are still needed to enable the study of airway SMC-EC communication with matrix interactions, and to provide higher throughput capabilities and manufacturability. We have developed a thermoplastic-based microfluidic lung airway-on-a-chip model that mimics the lung airway tissue microenvironment, and in particular, the interactions between SMCs, ECs, and supporting extracellular matrix (ECM). The microdevice is fabricated from acrylic using micromilling and solvent bonding techniques, and consists of three vertically stacked microfluidic compartments with a bottom media reservoir for SMC culture, a middle thin hydrogel layer, and an upper microchamber for achieving air-liquid interface (ALI) culture of the epithelium. A unique aspect of the design lies in the suspended hydrogel with upper and lower interfaces for EC and SMC culture, respectively. A mixture of type I collagen and Matrigel was found to promote EC adhesion and monolayer formation, and SMC adhesion and alignment. Optimal culturing protocols were established that enabled EC-SMC coculture for more than 31 days. Epithelial monolayers displayed common morphological markers including ZO-1 tight junctions and F-actin cell cortices, while

The effects of human serum to the morphology, proliferation and gene expression level of the respiratory epithelium in vitro.

PubMed

Yunus, Mohd Heikal Mohd; Siang, Kan Chan; Hashim, Nurul Izzati; Zhi, Ng Pei; Zamani, Nur Fathurah; Sabri, Primuharsa Putra; Busra, Mohd Fauzi; Chowdhury, Shiplu Roy; Idrus, Ruszymah Binti Haji

2014-08-01

The culture of human airway epithelial cells has played an important role in advancing our understanding of the metabolic and molecular mechanisms underlying normal function and disease pathology of airway epithelial cells. The present study focused on investigating the effects of human serum (HS) on the qualitative and quantitative properties of the human respiratory epithelium compared to the fetal bovine serum (FBS), as a supplement in culture. Respiratory epithelial (RE) cells derived from human nasal turbinate were co-cultured with fibroblasts, subsequently separated at 80-90% confluency by differential trypsinization. RE cells were then sub-cultured into 2 different plates containing 5% allogenic HS and FBS supplemented media respectively up to passage 1 (P1). Cell morphology, growth rate, cell viability and population doubling time were assessed under light microscope, and levels of gene expression were measured via real time reverse transcriptase-polymerase chain reaction (qRT-PCR). RE cells appeared as polygonal shape and expanded when cultured in HS whereas RE cells in FBS were observed to be easily matured thus limit the RE cells expansion. Proliferation rate of RE cells in HS supplemented media (7673.18 ± 1207.15) was 3 times higher compared to RE in FBS supplemented media (2357.68 ± 186.85). Furthermore, RE cells cultured in HS-supplemented media required fewer days (9.15 ± 1.10) to double in numbers compared to cells cultured in FBS-supplemented media (13.66 ± 0.81). Both the differences were significant (p<0.05). However, there were no significant differences in the viability of RE cells in both groups (p=0.105). qRT-PCR showed comparable expressions of gene Cytokeratin-14 (CK-14), Cytokeratin-18 (CK-18) and Mucin-5 subtype B (MUC5B) in RE cells cultured in both groups (p>0.05). In conclusion, HS is a comparatively better choice of media supplement in accelerating growth kinetics of RE cells in vitro thus producing a better quality of respiratory

Air pollution induces enhanced mitochondrial oxidative stress in cystic fibrosis airway epithelium.

PubMed

Kamdar, O; Le, Wei; Zhang, J; Ghio, A J; Rosen, G D; Upadhyay, D

2008-10-29

We studied the effects of airborne particulate matters (PM) on cystic fibrosis (CF) epithelium. We noted that PM enhanced human CF bronchial epithelial apoptosis, activated caspase-9 and PARP-1; and reduced mitochondrial membrane potential. Mitochondrial inhibitors (4,4-diisothiocyanatostilbene-2,2'disulfonic acid, rotenone and thenoyltrifluoroacetone) blocked PM-induced generation of reactive oxygen species and apoptosis. PM upregulated pro-apoptotic Bad, Bax, p53 and p21; and enhanced mitochondrial localization of Bax. The anti-apoptotic Bcl-2, Bcl-xl, Mcl-1 and Xiap remained unchanged; however, overexpression of Bcl-xl blocked PM-induced apoptosis. Accordingly, we provide the evidence that PM enhances oxidative stress and mitochondrial signaling mediated apoptosis via the modulation of Bcl family proteins in CF.

The junctional epithelium originates from the odontogenic epithelium of an erupted tooth

PubMed Central

Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

2014-01-01

The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period. PMID:24785116

Secreted mucins and airway bacterial colonization in non-CF bronchiectasis.

PubMed

Sibila, Oriol; Suarez-Cuartin, Guillermo; Rodrigo-Troyano, Ana; Fardon, Thomas C; Finch, Simon; Mateus, Eder Freddy; Garcia-Bellmunt, Laia; Castillo, Diego; Vidal, Silvia; Sanchez-Reus, Ferran; Restrepo, Marcos I; Chalmers, James D

2015-10-01

Secreted mucins play a key role in antibacterial defence in the airway, but have not previously been characterized in non-cystic fibrosis (CF) bronchiectasis patients. We aim to investigate the relationship between secreted mucins levels and the presence of bacterial colonization due to potentially pathogenic microorganisms (PPM) in the airways of stable bronchiectasis patients. Clinically stable bronchiectasis patients were studied prospectively at two centres. Patients with other pulmonary conditions were excluded. Spontaneous sputum was subject to bacterial culture, and secreted mucins (MUC2, MUC5AC and MUC5B) were measured in sputum supernatants by ELISA. A total of 50 patients were included. PPM were identified from sputum samples in 30 (60%), with Pseudomonas aeruginosa (n = 10) and Haemophilus influenzae (n = 10) as the most common PPM. There were no baseline differences among airway colonized and non-colonized patients. Patients with airways colonized by PPM presented higher levels of airway MUC2. No differences in MUC5AC levels were found among groups, whereas MUC5B levels were undetectable. Patients with P. aeruginosa colonization expressed the highest levels of MUC2. High levels of MUC2 and MUC5AC are also correlated with disease severity using the Bronchiectasis Severity Index. Airway MUC2 levels were higher in bronchiectasis patients colonized with PPM compared with those without airway colonization, especially in patients with P. aeruginosa. These findings suggest that airway-secreted mucins levels may play a role in the pathogenesis of airway infection in non-CF bronchiectasis. © 2015 Asian Pacific Society of Respirology.

Expressions of TRPVs in the cholesteatoma epithelium.

PubMed

Do, Ba Hung; Koizumi, Hiroki; Ohbuchi, Toyoaki; Kawaguchi, Rintaro; Suzuki, Hideaki

2017-10-01

We have recently proposed a hypothesis that acid leakage through the cholesteatoma epithelium mediates bone resorption in middle ear cholesteatoma. In the present study, we investigated the expressions of transient receptor potential vanilloid (TRPV) channels, which have been shown to play roles in the regulation of epidermal barrier function, in the cholesteatoma epithelium in comparison with the normal skin. Cholesteatoma epithelium and postauricular skin were collected from 17 patients with primary acquired middle ear cholesteatoma who underwent tympanomastoidectomy. Expressions of TRPV1, TRPV3, TRPV4, and TRPV6 were explored by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). TRPV1, TRPV3, TRPV4, and TRPV6 mRNAs were all detected by qRT-PCR both in the skin and cholesteatoma tissue. Immunohistochemical staining showed that TRPV1 and TRPV3 were positive in the viable cell layers of the epidermis of the skin, and only TRPV3 was positive in those of the cholesteatoma epithelium. The immunoreactivity for TRPV3 was significantly weaker in cholesteatoma than in the skin. The lower expression of TRPV3 in cholesteatoma may be one of the mechanisms underlying the increased permeability of this tissue. On the other hand, TRPV1, TRPV4, and TRPV6 are unlikely to be involved in the regulation of epithelial permeability in cholesteatoma.

Administration of SIN-1 induces guinea pig airway hyperresponsiveness through inactivation of airway neutral endopeptidase.

PubMed

Kanazawa, H; Hirata, K; Yoshikawa, J

1999-12-01

Peroxynitrite plays an important role in the pathogenesis of airway inflammation. We have already found that peroxynitrite may contribute to decreased beta(2)-adrenoceptor responses in airway smooth muscle. However, it is not known whether peroxynitrite can alter neutral endopeptidase (EC 3.4.24.11; NEP) activity in the airways. This study was designed to determine whether peroxynitrite induces airway hyperresponsiveness to substance P (SP) and endothelin-1 (ET-1) through the inactivation of airway NEP. We examined whether the administration of S-morpholinosydnonimine (SIN-1), a compound that releases peroxynitrite, increased bronchoconstrictor responses to SP and ET-1 in anesthetized guinea pigs. In addition, we assayed NEP activity in the airways of SIN-1-exposed guinea pigs. Though SIN-1 (10(-7) M) alone had no effect on pulmonary resistance, pretreatment with SIN-1 significantly enhanced SP- and ET-1-induced bronchoconstriction. Pretreatment with phosphoramidon, an NEP inhibitor, also enhanced SP- and ET-1-induced bronchoconstriction. However, simultaneous administration of phosphoramidon and SIN-1 had no additive effect on SP- and ET-1-induced bronchoconstriction. Peroxynitrite formation by SIN-1 was completely inhibited by N-acetylcysteine (NAC) and glutathione (GSH) in vitro, and pretreatment with NAC and GSH significantly reversed the potentiation by SIN-1 of SP-induced bronchoconstriction. In addition, the NEP activity of the trachea after SIN-1 exposure was significantly reduced compared to the level in control guinea pigs (solvent for SIN-1: 30.0+/-4.2 fmol.min(-1).mg tissue(-1); 10(-7) M SIN-1; 15.5+/-4.5 fmol.min(-1).mg tissue(-1), p<0.05). These findings suggest that peroxynitrite induces airway hyperresponsiveness to SP and ET-1 through the inactivation of airway NEP, and that peroxynitrite is an important mediator of the alterations in airway functions.

[Epithelial mesenchymal transition in airway remodeling of asthma and its molecular regulation].

PubMed

Zhu, Xiaohua; Li, Qiugen

2018-05-28

Asthma is a chronic inflammatory disease of the airway. Repeated inflammatory injury and tissue repair can lead to airway remodeling. The airway epithelial mesenchymal transformation (EMT) plays an important role in airway remodeling of asthma. Various cytokines and signaling pathways, such as transforming growth factor β (TGF-β), nuclear factor-kappa B (NF-κB) and bromodomain-containing protein 4 (BRD4), are involved in the molecular regulation of EMT.

Enhanced Viral Replication and Modulated Innate Immune Responses in Infant Airway Epithelium following H1N1 Infection

PubMed Central

Clay, Candice C.; Reader, J. Rachel; Gerriets, Joan E.; Wang, Theodore T.; Harrod, Kevin S.

2014-01-01

ABSTRACT Influenza is the cause of significant morbidity and mortality in pediatric populations. The contribution of pulmonary host defense mechanisms to viral respiratory infection susceptibility in very young children is poorly understood. As a surrogate to compare mucosal immune responses of infant and adult lungs, rhesus monkey primary airway epithelial cell cultures were infected with pandemic influenza A/H1N1 virus in vitro. Virus replication, cytokine secretion, cell viability, and type I interferon (IFN) pathway PCR array profiles were evaluated for both infant and adult cultures. In comparison with adult cultures, infant cultures showed significantly increased levels of H1N1 replication, reduced alpha interferon (IFN-α) protein synthesis, and no difference in cell death following infection. Age-dependent differences in expression levels of multiple genes associated with the type I IFN pathway were observed in H1N1-infected cultures. To investigate the pulmonary and systemic responses to H1N1 infection in early life, infant monkeys were inoculated with H1N1 by upper airway administration. Animals were monitored for virus and parameters of inflammation over a 14-day period. High H1N1 titers were recovered from airways at day 1, with viral RNA remaining detectable until day 9 postinfection. Despite viral clearance, bronchiolitis and alveolitis persisted at day 14 postinfection; histopathological analysis revealed alveolar septal thickening and intermittent type II pneumocyte hyperplasia. Our overall findings are consistent with the known susceptibility of pediatric populations to respiratory virus infection and suggest that intrinsic developmental differences in airway epithelial cell immune function may contribute to the limited efficacy of host defense during early childhood. IMPORTANCE To the best of our knowledge, this study represents the first report of intrinsic developmental differences in infant airway epithelial cells that may contribute to the

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Difficult Airway Society 'ADEPT' guidance on selecting airway devices: the basis of a strategy for equipment evaluation.

PubMed

Pandit, J J; Popat, M T; Cook, T M; Wilkes, A R; Groom, P; Cooke, H; Kapila, A; O'Sullivan, E

2011-08-01

Faced with the concern that an increasing number of airway management devices were being introduced into clinical practice with little or no prior evidence of their clinical efficacy or safety, the Difficult Airway Society formed a working party (Airway Device Evaluation Project Team) to establish a process by which the airway management community within the profession could itself lead a process of formal device/equipment evaluation. Although there are several national and international regulations governing which products can come on to the market and be legitimately sold, there has hitherto been no formal professional guidance relating to how products should be selected (i.e. purchased). The Airway Device Evaluation Project Team's first task was to formulate such advice, emphasising evidence-based principles. Team discussions led to a definition of the minimum level of evidence needed to make a pragmatic decision about the purchase or selection of an airway device. The Team concluded that this definition should form the basis of a professional standard, guiding those with responsibility for selecting airway devices. We describe how widespread adoption of this professional standard can act as a driver to create an infrastructure in which the required evidence can be obtained. Essential elements are that: (i) the Difficult Airway Society facilitates a coherent national network of research-active units; and (ii) individual anaesthetists in hospital trusts play a more active role in local purchasing decisions, applying the relevant evidence and communicating their purchasing decisions to the Difficult Airway Society. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

Mathematical model reveals role of nucleotide signaling in airway surface liquid homeostasis and its dysregulation in cystic fibrosis

PubMed Central

Sandefur, Conner I.; Boucher, Richard C.; Elston, Timothy C.

2017-01-01

Mucociliary clearance is composed of three components (i.e., mucin secretion, airway surface hydration, and ciliary-activity) which function coordinately to clear inhaled microbes and other foreign particles from airway surfaces. Airway surface hydration is maintained by water fluxes driven predominantly by active chloride and sodium ion transport. The ion channels that mediate electrogenic ion transport are regulated by extracellular purinergic signals that signal through G protein-coupled receptors. These purinoreceptors and the signaling pathways they activate have been identified as possible therapeutic targets for treating lung disease. A systems-level description of airway surface liquid (ASL) homeostasis could accelerate development of such therapies. Accordingly, we developed a mathematical model to describe the dynamic coupling of ion and water transport to extracellular purinergic signaling. We trained our model from steady-state and time-dependent experimental measurements made using normal and cystic fibrosis (CF) cultured human airway epithelium. To reproduce CF conditions, reduced chloride secretion, increased potassium secretion, and increased sodium absorption were required. The model accurately predicted ASL height under basal normal and CF conditions and the collapse of surface hydration due to the accelerated nucleotide metabolism associated with CF exacerbations. Finally, the model predicted a therapeutic strategy to deliver nucleotide receptor agonists to effectively rehydrate the ASL of CF airways. PMID:28808008

Expression of taste receptors in Solitary Chemosensory Cells of rodent airways

PubMed Central

2011-01-01

Background Chemical irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnea, and laryngeal closure. Inhaled irritants can activate either chemosensitive free nerve endings, laryngeal taste buds or solitary chemosensory cells (SCCs). The SCC population lies in the nasal respiratory epithelium, vomeronasal organ, and larynx, as well as deeper in the airway. The objective of this study is to map the distribution of SCCs within the airways and to determine the elements of the chemosensory transduction cascade expressed in these SCCs. Methods We utilized a combination of immunohistochemistry and molecular techniques (rtPCR and in situ hybridization) on rats and transgenic mice where the Tas1R3 or TRPM5 promoter drives expression of green fluorescent protein (GFP). Results Epithelial SCCs specialized for chemoreception are distributed throughout much of the respiratory tree of rodents. These cells express elements of the taste transduction cascade, including Tas1R and Tas2R receptor molecules, α-gustducin, PLCβ2 and TrpM5. The Tas2R bitter taste receptors are present throughout the entire respiratory tract. In contrast, the Tas1R sweet/umami taste receptors are expressed by numerous SCCs in the nasal cavity, but decrease in prevalence in the trachea, and are absent in the lower airways. Conclusions Elements of the taste transduction cascade including taste receptors are expressed by SCCs distributed throughout the airways. In the nasal cavity, SCCs, expressing Tas1R and Tas2R taste receptors, mediate detection of irritants and foreign substances which trigger trigeminally-mediated protective airway reflexes. Lower in the respiratory tract, similar chemosensory cells are not related to the trigeminal nerve but may still trigger local epithelial responses to irritants. In total, SCCs should be considered chemoreceptor cells that help in preventing damage to the respiratory tract caused by inhaled irritants and pathogens. PMID:21232137

Expression of taste receptors in solitary chemosensory cells of rodent airways.

PubMed

Tizzano, Marco; Cristofoletti, Mirko; Sbarbati, Andrea; Finger, Thomas E

2011-01-13

Chemical irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnea, and laryngeal closure. Inhaled irritants can activate either chemosensitive free nerve endings, laryngeal taste buds or solitary chemosensory cells (SCCs). The SCC population lies in the nasal respiratory epithelium, vomeronasal organ, and larynx, as well as deeper in the airway. The objective of this study is to map the distribution of SCCs within the airways and to determine the elements of the chemosensory transduction cascade expressed in these SCCs. We utilized a combination of immunohistochemistry and molecular techniques (rtPCR and in situ hybridization) on rats and transgenic mice where the Tas1R3 or TRPM5 promoter drives expression of green fluorescent protein (GFP). Epithelial SCCs specialized for chemoreception are distributed throughout much of the respiratory tree of rodents. These cells express elements of the taste transduction cascade, including Tas1R and Tas2R receptor molecules, α-gustducin, PLCβ2 and TrpM5. The Tas2R bitter taste receptors are present throughout the entire respiratory tract. In contrast, the Tas1R sweet/umami taste receptors are expressed by numerous SCCs in the nasal cavity, but decrease in prevalence in the trachea, and are absent in the lower airways. Elements of the taste transduction cascade including taste receptors are expressed by SCCs distributed throughout the airways. In the nasal cavity, SCCs, expressing Tas1R and Tas2R taste receptors, mediate detection of irritants and foreign substances which trigger trigeminally-mediated protective airway reflexes. Lower in the respiratory tract, similar chemosensory cells are not related to the trigeminal nerve but may still trigger local epithelial responses to irritants. In total, SCCs should be considered chemoreceptor cells that help in preventing damage to the respiratory tract caused by inhaled irritants and pathogens.

IL-33: biological properties, functions, and roles in airway disease.

PubMed

Drake, Li Yin; Kita, Hirohito

2017-07-01

Interleukin (IL)-33 is a key cytokine involved in type 2 immunity and allergic airway diseases. Abundantly expressed in lung epithelial cells, IL-33 plays critical roles in both innate and adaptive immune responses in mucosal organs. In innate immunity, IL-33 and group 2 innate lymphoid cells (ILC2s) provide an essential axis for rapid immune responses and tissue homeostasis. In adaptive immunity, IL-33 interacts with dendritic cells, Th2 cells, follicular T cells, and regulatory T cells, where IL-33 influences the development of chronic airway inflammation and tissue remodeling. The clinical findings that both the IL-33 and ILC2 levels are elevated in patients with allergic airway diseases suggest that IL-33 plays an important role in the pathogenesis of these diseases. IL-33 and ILC2 may also serve as biomarkers for disease classification and to monitor the progression of diseases. In this article, we reviewed the current knowledge of the biology of IL-33 and discussed the roles of the IL-33 in regulating airway immune responses and allergic airway diseases. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yuan, E-mail: yuan.xu@ki.se; Cardell, Lars-Olaf

Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin-more » (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance

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. © 2016 Asian Pacific Society of Respirology.

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.

Polymeric nanocarriers for transport modulation across the pulmonary epithelium: dendrimers, polymeric nanoparticles, and their nanoblends.

PubMed

Bharatwaj, Balaji; Dimovski, Radovan; Conti, Denise S; da Rocha, Sandro R P

2014-05-01

The purpose of this study was to (a) Determine the cellular transport and uptake of amine-terminated generation 3 (G3) poly(amido amine) (PAMAM) dendrimers across an in vitro model of the pulmonary epithelium, and the ability to modulate their transport by forming nanoblends of the dendrimers with biodegradable solid polymeric nanoparticles (NPs) and (b) to formulate dendrimer nanocarriers in portable oral inhalation devices and evaluate their aerosol characteristics. To that end, fluorescein isothiocyanate (FITC)-labeled G3 PAMAM dendrimer nanocarriers (DNCs) were synthesized, and also encapsulated within poly lactide-co-glycolide nanoparticles (NPs). Transport and uptake of both DNCs encapsulated within NPs (nanoblends) and unencapsulated DNCs were tracked across polarized monolayers of airway epithelial cells, Calu-3. DNCs were also formulated as core-shell microparticles in pressurized metered-dose inhalers (pMDIs) and their aerodynamic properties evaluated by Andersen cascade impaction. The apparent permeability of DNCs across the airway epithelial model was similar to that of a paracellular marker of comparable molar mass--order of 10(-7) cm s(-1). The transport and cellular internalization of the DNCs can be modulated by formulating them as nanoblends. The transport of the DNCs across the lung epithelium was completely suppressed within the time of the experiment (5 h) when formulated as blends. The encapsulation also prevents saturation of the cellular internalization profile. Nanoblending may be a potential strategy to modulate the rate of transport and cellular uptake of DNCs, and thus be used as a design strategy to achieve enhanced local or systemic drug delivery.

[Surfactants of the airways. Critical review and personal research].

PubMed

Mira, E; Benazzo, M; De Paoli, F; Casasco, A; Calligaro, A

1997-02-01

The literature proving the presence of a surface tension lowering substance (STLS) on the lining layer of mammalian Eustachian tube (ET) is critically reviewed. A further review of the chemical studies on tubal washings based on chromatographic analysis methods (TLC and HPLC) is performed, and is concluded that ET epithelium is coated by a mixture of phospholipids, similar but not identical to the pulmonary surfactant and with similar but less powerful surface activity. In both cases, and with minor differences between the different mammalian species, phosphatidylcholine (PC), and in particular its disaturated fraction, dipalmitoilphosphatidylcholine (DPPC), is the predominating and the most active compound. ET surfactant is synthesized by ET epithelium and secreted in form of osmiophilic multilamellar bodies into the tubal lumen. The exact function of the ET surfactant is not fully understood: it may play an important role in ET physiology by facilitating the tubal opening to allow for aeration of the middle ear and adequate drainage or could act as a release agent, preventing solid-to-solid adhesion of the tubal walls and contrasting the adhesive action of the glycoproteins of the mucous blanket. On the other hand a phospholipidic surfactant seems to be produced by the mucosa of the other parts of the upper airways, i.e. nose and trachea. In this case a surface active agent could act in preventing the transudation of serum into the lumen, in enhancing the phagocytosis or in facilitating the mucociliary transport. Recent data on humans, suggesting that a relative deficiency or an alterated production of tubal surfactant could play a role in the pathogenesis of secretory otitis media (SOM) or middle ear effusion (MEE), are reviewed. Administration of exogenous surfactant or pharmacological stimulation of the production of tubal surfactant could improve ET function and be of value in some cases of SOM. Personal data, suggesting than ambroxol (a drug stimulating the

Airway Fibrinogenolysis and the Initiation of Allergic Inflammation

PubMed Central

Millien, Valentine Ongeri; Lu, Wen; Mak, Garbo; Yuan, Xiaoyi; Knight, J. Morgan; Porter, Paul; Kheradmand, Farrah

2014-01-01

The past 15 years of allergic disease research have produced extraordinary improvements in our understanding of the pathogenesis of airway allergic diseases such as asthma. Whereas it was previously viewed as largely an immunoglobulin E-mediated process, the gradual recognition that T cells, especially Type 2 T helper (Th2) cells and Th17 cells, play a major role in asthma and related afflictions has inspired clinical trials targeting cytokine-based inflammatory pathways that show great promise. What has yet to be clarified about the pathogenesis of allergic inflammatory disorders, however, are the fundamental initiating factors, both exogenous and endogenous, that drive and sustain B- and T-cell responses that underlie the expression of chronic disease. Here we review how proteinases derived from diverse sources drive allergic responses. A central discovery supporting the proteinase hypothesis of allergic disease pathophysiology is the role played by airway fibrinogen, which in part appears to serve as a sensor of unregulated proteinase activity and which, when cleaved, both participates in a novel allergic signaling pathway through Toll-like receptor 4 and forms fibrin clots that contribute to airway obstruction. Unresolved at present is the ultimate source of airway allergenic proteinases. From among many potential candidates, perhaps the most intriguing is the possibility such enzymes derive from airway fungi. Together, these new findings expand both our knowledge of allergic disease pathophysiology and options for therapeutic intervention. PMID:25525732

Comparison of vectorial ion transport in primary murine airway and human sinonasal air-liquid interface cultures, models for studies of cystic fibrosis, and other airway diseases.

PubMed

Zhang, Shaoyan; Fortenberry, James A; Cohen, Noam A; Sorscher, Eric J; Woodworth, Bradford A

2009-01-01

The purpose of this study was to compare vectorial ion transport within murine trachea, murine nasal septa, and human sinonasal cultured epithelium. Our hypothesis is that murine septal epithelium, rather than trachea, will more closely mimic the electrophysiology properties of human sinonasal epithelium. Epithelium from murine trachea, murine septa, and human sinonasal tissue were cultured at an air-liquid interface to confluence and full differentiation. A limited number of homozygous dF508 epithelia were also cultured. Monolayers were mounted in modified Ussing chambers to investigate pharmacologic manipulation of ion transport. The change in forskolin-stimulated current (delta-I(SC), expressed as micro-A/cm(2)) in murine septal (n = 19; 16.84 +/- 2.09) and human sinonasal (n = 18; 12.15 +/- 1.93) cultures was significantly increased over murine tracheal cultures (n = 15; 6.75 +/- 1.35; p = 0.035 and 0.0005, respectively). Forskolin-stimulated I(SC) was inhibited by the specific cystic fibrosis transmembrane regulator (CFTR) inhibitor INH-172 (5 microM). No forskolin-stimulated I(SC) was shown in cultures of dF508 homozygous murine septal epithelium (n = 3). Murine septal I(SC) was largely inhibited by amiloride (12.03 +/- 0.66), whereas human sinonasal cultures had a very limited response (0.70 +/- 0.47; p < 0.0001). The contribution of CFTR to stimulated chloride current as measured by INH-172 was highly significantly different between all groups (murine septa, 19.51 +/- 1.28; human sinonasal, 11.12 +/- 1.58; murine trachea, 4.85 +/- 0.49; p < 0.0001). Human sinonasal and murine septal epithelial cultures represent a useful model for studying CFTR activity and may provide significant advantages over lower airway tissues for investigating upper and lower respiratory pathophysiology.

Bacillus licheniformis in geogenic dust induces inflammation in respiratory epithelium.

PubMed

Pickering, Janessa; Teo, Teck Hui; Thornton, Ruth B; Kirkham, Lea-Ann; Zosky, Graeme R; Clifford, Holly D

2018-07-01

Exposure to environmental geogenic (or earth-derived) dust can lead to more frequent and severe infections in the human airway. Particulate matter < 10 µm (PM 10 ) is the component of air pollution that is commonly associated with the exacerbation of respiratory diseases. We have previously demonstrated that mice exposed to geogenic dust PM 10 experienced an exacerbation of inflammatory responses to influenza A virus. Whether geogenic dust PM 10 also exacerbates respiratory bacterial infection is not yet known, nor are the components of the dust that drive these responses. We treated airway bronchial epithelial cells (NuLi-1) with UV-irradiated geogenic dust PM 10 from six remote Western Australian towns. High levels of IL-6 and IL-8 production were observed, as well as persistent microbial growth. 16 S rRNA sequencing of the growth identified the microbe as Bacillus licheniformis, a spore-forming, environmentally abundant bacterium. We next investigated the interaction of B. licheniformis with respiratory epithelium in vitro to determine whether this exacerbated infection with a bacterial respiratory pathogen (non-typeable Haemophilus influenzae, NTHi). Heat treatment (100 °C) of all PM 10 samples eliminated B. licheniformis contamination and reduced epithelial inflammatory responses, suggesting that heat-labile and/or microbial factors were involved in the host response to geogenic dust PM 10 . We then exposed NuLi-1 epithelium to increasing doses of the isolated Bacillus licheniformis (multiplicity of infection of 10:1, 1:1 or 0.1:1 bacteria: cells) for 1, 3, and 24 h. B. licheniformis and NTHi infection (association and invasion) was assessed using a standard gentamicin survival assay, and epithelial release of IL-6 and IL-8 was measured using a bead based immunoassay. B. licheniformis was cytotoxic to NuLi-1 cells at 24 h. At 3 h post-challenge, B. licheniformis elicited high IL-6 and IL-8 inflammatory responses from NuLi-1 cells compared with

Regulation of xanthine dehydrogensase gene expression and uric acid production in human airway epithelial cells

PubMed Central

Huff, Ryan D.; Hsu, Alan C-Y.; Nichol, Kristy S.; Jones, Bernadette; Knight, Darryl A.; Wark, Peter A. B.; Hansbro, Philip M.

2017-01-01

Introduction The airway epithelium is a physical and immunological barrier that protects the pulmonary system from inhaled environmental insults. Uric acid has been detected in the respiratory tract and can function as an antioxidant or damage associated molecular pattern. We have demonstrated that human airway epithelial cells are a source of uric acid. Our hypothesis is that uric acid production by airway epithelial cells is induced by environmental stimuli associated with chronic respiratory diseases. We therefore examined how airway epithelial cells regulate uric acid production. Materials and methods Allergen and cigarette smoke mouse models were performed using house dust mite (HDM) and cigarette smoke exposure, respectively, with outcome measurements of lung uric acid levels. Primary human airway epithelial cells isolated from clinically diagnosed patients with asthma and chronic obstructive pulmonary disease (COPD) were grown in submerged cultures and compared to age-matched healthy controls for uric acid release. HBEC-6KT cells, a human airway epithelial cell line, were grown under submerged monolayer conditions for mechanistic and gene expression studies. Results HDM, but not cigarette smoke exposure, stimulated uric acid production in vivo and in vitro. Primary human airway epithelial cells from asthma, but not COPD patients, displayed elevated levels of extracellular uric acid in culture. In HBEC-6KT, production of uric acid was sensitive to the xanthine dehydrogenase (XDH) inhibitor, allopurinol, and the ATP Binding Cassette C4 (ABCC4) inhibitor, MK-571. Lastly, the pro-inflammatory cytokine combination of TNF-α and IFN-γ elevated extracellular uric acid levels and XDH gene expression in HBEC-6KT cells. Conclusions Our results suggest that the active production of uric acid from human airway epithelial cells may be intrinsically altered in asthma and be further induced by pro-inflammatory cytokines. PMID:28863172

Bronchial airway gene expression signatures in mouse lung squamous cell carcinoma and their modulation by cancer chemopreventive agents

PubMed Central

Szabo, Eva; Miller, Mark Steven; Lubet, Ronald A.; You, Ming; Wang, Yian

2017-01-01

Due to exposure to environmental toxicants, a “field cancerization” effect occurs in the lung resulting in the development of a field of initiated but morphologically normal appearing cells in the damaged epithelium of bronchial airways with dysregulated gene expression patterns. Using a mouse model of lung squamous cell carcinoma (SCC), we performed transcriptome sequencing (RNA-Seq) to profile bronchial airway gene expression and found activation of the PI3K and Myc signaling networks in cytologically normal bronchial airway epithelial cells of mice with preneopastic lung SCC lesions, which was reversed by treatment with the PI3K Inhibitor XL-147 and pioglitazone, respectively. Activated MYC signaling was also present in premalignant and tumor tissues from human lung SCC patients. In addition, we identified a key microRNA, mmu-miR-449c-5p, whose suppression significantly up-regulated Myc expression in the normal bronchial airway epithelial cells of mice with early stage SCC lesions. We developed a novel bronchial genomic classifier in mice and validated it in humans. In the classifier, Ppbp (pro-platelet basic protein) was overexpressed 115 fold in the bronchial airways of mice with preneoplastic lung SCC lesions. This is the first report that demonstrates Ppbp as a novel biomarker in the bronchial airway for lung cancer diagnosis. PMID:27935865

Molecular architecture of the fruit fly's airway epithelial immune system.

PubMed

Wagner, Christina; Isermann, Kerstin; Fehrenbach, Heinz; Roeder, Thomas

2008-09-29

immune system of the fly's airway epithelium has a very peculiar organization. A great variety of pattern recognition receptors as well as of potential effector molecules are conspicuous, whereas signalling presumably occurs through a single NF-kappaB activating pathway. This architecture will allow reacting if confronted with different bacterial or fungal elicitors by activation of a multitude of effectors.

Use of optical coherence tomography in delineating airways microstructure: comparison of OCT images to histopathological sections

NASA Astrophysics Data System (ADS)

Yang, Ying; Whiteman, Suzanne; Gey van Pittius, Daniel; He, Yonghong; Wang, Ruikang K.; Spiteri, Monica A.

2004-04-01

An ideal diagnostic system for the human airways should be able to detect and define early development of premalignant pathological lesions, to facilitate optimal curative treatment and prevent irreversible and/or invasive lung disease. There is great need for exploration of safe, repeatable imaging techniques which can run at real-time and with high spatial resolution. In this study, optical coherence tomography (OCT) was utilized to acquire cross-sectional images of upper and lower airways using fresh pig lung resections as a model system. Obtained OCT images were compared with parallel tissue characterization by conventional histological analysis. Our objective was to determine whether OCT differentiates the composite structural layers and inherent anatomical variations along different airway locations. The data show that OCT can clearly display the multilayered structure of the airways. The subtle architectural differences in three separate anatomical locations including trachea, main bronchus and tertiary bronchus were clearly delineated. Images of the appropriate anatomical profiles, with depth of up to 2 mm and 10 µm spatial resolution were obtained by our current OCT system, which was sufficient for recognition of the epithelium, subepithelial tissues and cartilage. In addition, the relative thickness of individual structural components was accurately reflected and comparable to histological sections. These data support OCT as a highly feasible, optical biopsy tool, which merits further exploration for early diagnosis of human airway epithelial pathology.

Normoxic Cyclic GMP-independent Oxidative Signaling by Nitrite Enhances Airway Epithelial Cell Proliferation and Wound Healing

PubMed Central

Wang, Ling; Frizzell, Sheila A.; Zhao, Xuejun; Gladwin, Mark T.

2013-01-01

The airway epithelium provides important barrier and host defense functions. Recent studies reveal that nitrite is an endocrine reservoir of nitric oxide (NO) bioactivity that is converted to NO by enzymatic reductases along the physiological oxygen gradient. Nitrite signaling has been described as NO dependent activation mediated by reactions with deoxygenated redox active hemoproteins, such as hemoglobin, myoglobin, neuroglobin, xanthine oxidoreductase (XO) and NO synthase at low pH and oxygen tension. However, nitrite can also be readily oxidized to nitrogen dioxide (NO2•) via heme peroxidase reactions, suggesting the existence of alternative oxidative signaling pathways for nitrite under normoxic conditions. In the present study we examined normoxic signaling effects of sodium nitrite on airway epithelial cell wound healing. In an in vitro scratch injury model under normoxia, we exposed cultured monolayers of human airway epithelial cells to various concentrations of sodium nitrite and compared responses to NO donor. We found sodium nitrite potently enhanced airway epithelium wound healing at physiological concentrations (from 1uM). The effect of nitrite was blocked by the NO and NO2• scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (c-PTIO). Interestingly, nitrite treatment did not increase cyclic guanosine monophosphate (cGMP) levels under these normoxic conditions, even in the presence of a phosphodiesterase 5 inhibitor, suggesting cGMP independent signaling. Consistent with an oxidative signaling pathway requiring hydrogen peroxide (H2O2)/heme peroxidase/NO2• signaling, the effects of nitrite were potentiated by superoxide dismutase (SOD) and low concentration H2O2, whereas inhibited completely by catalase, followed by downstream extracellular-signal-regulated kinase (ERK) 1/2 activation. Our data represent the first description of normoxic nitrite signaling on lung epithelial cell proliferation and wound healing and suggest

Purification and characterization of factors produced by Aspergillus fumigatus which affect human ciliated respiratory epithelium.

PubMed Central

Amitani, R; Taylor, G; Elezis, E N; Llewellyn-Jones, C; Mitchell, J; Kuze, F; Cole, P J; Wilson, R

1995-01-01

The mechanisms by which Aspergillus fumigatus colonizes the respiratory mucosa are unknown. Culture filtrates of eight of nine clinical isolates of A. fumigatus slowed ciliary beat frequency and damaged human respiratory epithelium in vitro. These changes appeared to occur concurrently. Culture filtrates of two clinical isolates of Candida albicans had no effect on ciliated epithelium. We have purified and characterized cilioinhibitory factors of a clinical isolate of A. fumigatus. The cilioinhibitory activity was heat labile, reduced by dialysis, and partially extractable into chloroform. The activity was associated with both high- and low-molecular-weight factors, as determined by gel filtration on Sephadex G-50. A low-molecular-weight cilioinhibitory factor was further purified by reverse-phase high-performance liquid chromatography and shown by mass spectrometry to be gliotoxin, a known metabolite of A. fumigatus. Gliotoxin significantly slowed ciliary beat frequency in association with epithelial damage at concentrations above 0.2 microgram/ml; other Aspergillus toxins, i.e., fumagillin and helvolic acid, were also cilioinhibitory but at much higher concentrations. High-molecular-weight (> or = 35,000 and 25,000) cilioinhibitory materials had neither elastolytic nor proteolytic activity and remain to be identified. Thus, A. fumigatus produces a number of biologically active substances which slow ciliary beating and damage epithelium and which may influence colonization of the airways. PMID:7543879

Purification and characterization of factors produced by Aspergillus fumigatus which affect human ciliated respiratory epithelium.

PubMed

Amitani, R; Taylor, G; Elezis, E N; Llewellyn-Jones, C; Mitchell, J; Kuze, F; Cole, P J; Wilson, R

1995-09-01

The mechanisms by which Aspergillus fumigatus colonizes the respiratory mucosa are unknown. Culture filtrates of eight of nine clinical isolates of A. fumigatus slowed ciliary beat frequency and damaged human respiratory epithelium in vitro. These changes appeared to occur concurrently. Culture filtrates of two clinical isolates of Candida albicans had no effect on ciliated epithelium. We have purified and characterized cilioinhibitory factors of a clinical isolate of A. fumigatus. The cilioinhibitory activity was heat labile, reduced by dialysis, and partially extractable into chloroform. The activity was associated with both high- and low-molecular-weight factors, as determined by gel filtration on Sephadex G-50. A low-molecular-weight cilioinhibitory factor was further purified by reverse-phase high-performance liquid chromatography and shown by mass spectrometry to be gliotoxin, a known metabolite of A. fumigatus. Gliotoxin significantly slowed ciliary beat frequency in association with epithelial damage at concentrations above 0.2 microgram/ml; other Aspergillus toxins, i.e., fumagillin and helvolic acid, were also cilioinhibitory but at much higher concentrations. High-molecular-weight (> or = 35,000 and 25,000) cilioinhibitory materials had neither elastolytic nor proteolytic activity and remain to be identified. Thus, A. fumigatus produces a number of biologically active substances which slow ciliary beating and damage epithelium and which may influence colonization of the airways.

Visualization of ex vivo human ciliated epithelium and induced flow using optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ling, Yuye; Gamm, Uta A.; Yao, Xinwen; Arteaga-Solis, Emilio; Emala, Charles W.; Choma, Michael A.; Hendon, Christine P.

2017-04-01

The ciliated epithelium is important to the human respiratory system because it clears mucus that contains harmful microorganisms and particulate matter. We report the ex vivo visualization of human trachea/bronchi ciliated epithelium and induced flow characterized by using spectral-domain optical coherence tomography (SD-OCT). A total number of 17 samples from 7 patients were imaged. Samples were obtained from Columbia University Department of Anesthesiology's tissue bank. After excision, the samples were placed in Gibco Medium 199 solution with oxygen at 4°C until imaging. The samples were maintained at 36.7°C throughout the experiment. The imaging protocol included obtaining 3D volumes and 200 consecutive B-scans parallel to the head-to-feet direction (superior-inferior axis) of the airway, using Thorlabs Telesto system at 1300 nm at 28 kHz A-line rate and a custom built high resolution SDOCT system at 800nm at 32 kHz A-line rate. After imaging, samples were processed with H and E histology. Speckle variance of the time resolved datasets demonstrate significant contrast at the ciliated epithelium sites. Flow images were also obtained after injecting 10μm polyester beads into the solution, which shows beads traveling trajectories near the ciliated epithelium areas. In contrary, flow images taken in the orthogonal plane show no beads traveling trajectories. This observation is in line with our expectation that cilia drive flow predominantly along the superior-inferior axis. We also observed the protective function of the mucus, shielding the epithelium from the invasion of foreign objects such as microspheres. Further studies will be focused on the cilia's physiological response to environmental changes such as drug administration and physical injury.

Abnormal epithelial structure and chronic lung inflammation after repair of chlorine-induced airway injury

PubMed Central

Mo, Yiqun; Chen, Jing; Humphrey, David M.; Fodah, Ramy A.; Warawa, Jonathan M.

2014-01-01

Chlorine is a toxic gas used in a variety of industrial processes and is considered a chemical threat agent. High-level chlorine exposure causes acute lung injury, but the long-term effects of acute chlorine exposure are unclear. Here we characterized chronic pulmonary changes following acute chlorine exposure in mice. A/J mice were exposed to 240 parts per million-hour chlorine or sham-exposed to air. Chlorine inhalation caused sloughing of bronchial epithelium 1 day after chlorine exposure, which was repaired with restoration of a pseudostratified epithelium by day 7. The repaired epithelium contained an abnormal distribution of epithelial cells containing clusters of club or ciliated cells rather than the uniformly interspersed pattern of these cells in unexposed mice. Although the damaged epithelium in A/J mice was repaired rapidly, and minimal airway fibrosis was observed, chlorine-exposed mice developed pneumonitis characterized by infiltration of alveoli with neutrophils and prominent, large, foamy macrophages. Levels of CXCL1/KC, CXCL5/LPS-induced CXC chemokine, granulocyte colony-stimulating factor, and VEGF in bronchoalveolar (BAL) fluid from chlorine-exposed mice showed steadily increasing trends over time. BAL protein levels were increased on day 4 and remained elevated out to day 28. The number of bacteria cultured from lungs of chlorine-exposed mice 4 wk after exposure was not increased compared with sham-exposed mice, indicating that the observed pneumonitis was not driven by bacterial infection of the lung. The results indicate that acute chlorine exposure may cause chronic abnormalities in the lungs despite rapid repair of injured epithelium. PMID:25398987

Metachronal waves in epithelium cilia to transport bronchial mucus in airways

NASA Astrophysics Data System (ADS)

Favier, Julien; Sylvain, Chateau; D'Ortona, Umberto; Poncet, Sébastien

2017-11-01

Metachronal waves of beating cilia are an efficient mechanism to transport mucus in human airways. The numerical results we will present will shed new light on the understanding of chronic respiratory diseases, such as Asthma of COPD. A coupled lattice Boltzmann - Immersed Boundary is used to simulate the multiphase environment in which the cilia are immersed: a periciliary layer and the mucus layer. A purely hydrodynamical feedback of the fluids is taken into account, and a coupling parameter α is introduced, allowing the tuning of both the direction of the wave propagation, and the strength of the fluid feedback. The cilia, initially set in a random state, quickly synchronize with their immediate neighbors giving birth to metachronal waves. A comparative study of both antipleptic and sympleptic waves is performed by imposing the metachrony. Antiplectic waves are found to be the most efficient to transport and mix fluids compared to other random or synchronised cilia motions. The numerical results will be discussed and compared to experimental and clinical results obtained by collaborators, to progress on the understanding of the inner mechanisms of chronic respiratory diseases.

Airway somatosensory deficits and dysphagia in Parkinson's disease.

PubMed

Hammer, Michael J; Murphy, Caitlin A; Abrams, Trisha M

2013-01-01

Individuals with Parkinson's disease (PD) often experience substantial impairment of swallow control, and are typically unaware of the presence or severity of their impairments suggesting that these individuals may also experience airway sensory deficits. However, the degree to which impaired swallow function in PD may relate to airway sensory deficits has yet to be formally tested. The purpose of this study was to examine whether airway sensory function is associated with swallow impairment in PD. Eighteen PD participants and 18 healthy controls participated in this study and underwent endoscopic assessment of airway somatosensory function, endoscopic assessment of swallow function, and clinical ratings of swallow and disease severity. PD participants exhibited abnormal airway somatosensory function and greater swallow impairment compared with healthy controls. Swallow and sensory deficits in PD were correlated with disease severity. Moreover, PD participants reported similar self-rated swallow function as healthy controls, and swallow deficits were correlated with sensory function suggesting an association between impaired sensory function and poor self-awareness of swallow deficits in PD. These results suggest that control of swallow is influenced by airway somatosensory function, that swallow-related deficits in PD are related to abnormal somatosensation, and that swallow and airway sensory function may degrade as a function of disease severity. Therefore, the basal ganglia and related neural networks may play an important role to integrate airway sensory input for swallow-related motor control. Furthermore, the airway deficits observed in PD suggest a disintegration of swallow-related sensory and motor control.

Ion Transport by Pulmonary Epithelia

PubMed Central

Hollenhorst, Monika I.; Richter, Katrin; Fronius, Martin

2011-01-01

The lung surface of air-breathing vertebrates is formed by a continuous epithelium that is covered by a fluid layer. In the airways, this epithelium is largely pseudostratified consisting of diverse cell types such as ciliated cells, goblet cells, and undifferentiated basal cells, whereas the alveolar epithelium consists of alveolar type I and alveolar type II cells. Regulation and maintenance of the volume and viscosity of the fluid layer covering the epithelium is one of the most important functions of the epithelial barrier that forms the outer surface area of the lungs. Therefore, the epithelial cells are equipped with a wide variety of ion transport proteins, among which Na+, Cl−, and K+ channels have been identified to play a role in the regulation of the fluid layer. Malfunctions of pulmonary epithelial ion transport processes and, thus, impairment of the liquid balance in our lungs is associated with severe diseases, such as cystic fibrosis and pulmonary oedema. Due to the important role of pulmonary epithelial ion transport processes for proper lung function, the present paper summarizes the recent findings about composition, function, and ion transport properties of the airway epithelium as well as of the alveolar epithelium. PMID:22131798

Infection-induced airway fibrosis in two rat strains with differential susceptibility.

PubMed Central

McIntosh, J C; Simecka, J W; Ross, S E; Davis, J K; Miller, E J; Cassell, G H

1992-01-01

Chronic infections play a significant role in the morbidity and mortality of patients with chronic airflow limitation. By stimulating airway inflammation, persistent infection has the potential to cause airway fibrosis. However, in patient this condition is most typically found in lungs damaged by other factors, such as smoking, abnormal secretions, or barotrauma. We report the characterization of Mycoplasma pulmonis infection-induced lung fibrosis in two immunocompetent rat strains with no preexisting lung disease. The fibrosis was predominantly in the airways, as demonstrated by the findings for infected animals of increased airway inflammation, airway fibrosis, and airway wall thickness, which correlated with the collagen content of the lungs. Also, the physiological alterations were the opposite of those found in interstitial fibrosis, with a positive correlation between lung compliance and collagen content. The airway fibrosis was noted earlier and to a greater extent in Lewis rats than in Fisher rats, and this result apparently was related to regulation of the inflammatory response. Airway wall thickness, airway inflammation, and airway fibrosis are commonly reported in tissue specimens from patients with chronic airway diseases and have been shown to correlate with airflow limitation in patients with chronic obstructive pulmonary disease. Thus, this model may be useful in furthering our understanding of the role of chronic infection and airway inflammation in airflow obstruction. Images PMID:1612760

Functional short- and long-term effects of nasal CPAP with and without humidification on the ciliary function of the nasal respiratory epithelium.

PubMed

Sommer, J Ulrich; Kraus, Marius; Birk, Richard; Schultz, Johannes D; Hörmann, Karl; Stuck, Boris A

2014-03-01

Continuous positive airway pressure (CPAP) is the gold standard in the treatment of obstructive sleep apnea (OSA), but its impact on ciliary function is unclear to date. Furthermore, CPAP is associated with numerous side effects related to the nose and upper airway. Humidified CPAP is used to relieve these symptoms, but again, little is known regarding its effect on ciliary function of the nasal respiratory epithelium. In this prospective, randomized, crossover trial, 31 patients with OSA (AHI >15/h) were randomized to two treatment arms: nasal continuous positive airway pressure (nCPAP) with humidification or nCPAP without humidification for one night in each modality to assess short-term effects of ciliary beat frequency (CBF) and mucus transport time (MTT) and consecutively for 8 weeks in each modality to assess long-term effects in a crossover fashion. The baseline CBF was 4.8 ± 0.6 Hz, and baseline MTT was 540 ± 221 s. After one night of CPAP with and without humidification, ciliary function increased moderately yet with statistical significance (p <0.05). The short-term groups with and without humidification did not differ statistically significant. Regarding long-term effects of CPAP, a statistically significant increase in ciliary function above the baseline level and above the short-term level was shown without humidification (7.2 ± 0.4 Hz; 402 ± 176 s; p <0.01). The increase above baseline level was even more pronounced with humidification (9.3 ± 0.7 Hz; 313 ± 95 s; p <0.01). There was a statistically significant difference between both groups at long-term assessment with regard to CBF (p <0.01). Independent of airway humidification, nCPAP has moderate effects on short-term ciliary function of the nasal respiratory epithelium. However, a significant increase in ciliary function-both in terms of an increased CBF and a decreased MTT-was detected after long-term use. The effect was more pronounced when humidification was used during nCPAP.

Role of airway epithelial injury in murine orthotopic tracheal allograft rejection.

PubMed

Kuo, Elbert; Bharat, Ankit; Shih, Jennifer; Street, Tyler; Norris, Jenyi; Liu, Wei; Parks, William; Walter, Michael; Patterson, G Alexander; Mohanakumar, T

2006-10-01

Murine tracheal transplantation is a model used to study bronchiolitis obliterans syndrome, a major cause of morbidity and mortality after lung transplantation. Unlike murine heterotopic tracheal transplants, orthotopic transplantation does not cause luminal obliteration despite major histocompatibility antigen mismatch. Repopulation of the tracheal allografts with recipient-derived epithelium confers protection against luminal obliteration. The purpose of this study was to determine whether (1) orthotopic tracheal transplantation showed signs of allograft rejection, and (2) airway epithelial cell injury promoted orthotopic tracheal allograft rejection. Forty isogeneic (C57BL/6 to C57BL/6) and 40 allogeneic (BALB/c to C57BL/6) orthotopic tracheal transplants were performed. Damage to airway epithelial cells was induced by Sendai viral (SdV) infection and tracheal transplantation into non-reepithelializing matrix metalloproteinase-7 knockout (MMP7-KO) recipient mice. Percent fibrosis and lamina propria to cartilage ratio were calculated with computer assistance on harvested allografts. Allografts showed significantly more intramural fibrosis compared with isografts at 30, 60, and 180 days after transplant without luminal occlusion. Tracheal allografts infected with SdV showed an increase in fibrosis and lamina propria to cartilage ratio compared with noninfected controls. Allografts retrieved from MMP7-KO recipients also showed a significant increase in fibrosis and lamina propria to cartilage ratio. Although orthotopic tracheal transplantation does not cause luminal obliteration, it results in increased fibrosis in allografts. Damage to the respiratory epithelium by viral infection or defective reepithelialization after transplant as seen in MMP7-KO recipient mice leads to changes consistent with chronic allograft rejection, suggesting a role for epithelial injury in bronchiolitis obliterans syndrome development.

Central Role of the NF-κB Pathway in the Scgb1a1-Expressing Epithelium in Mediating Respiratory Syncytial Virus-Induced Airway Inflammation.

PubMed

Tian, Bing; Yang, Jun; Zhao, Yingxin; Ivanciuc, Teodora; Sun, Hong; Wakamiya, Maki; Garofalo, Roberto P; Brasier, Allan R

2018-06-01

Lower respiratory tract infection with respiratory syncytial virus (RSV) produces profound inflammation. Despite an understanding of the role of adaptive immunity in RSV infection, the identity of the major sentinel cells initially triggering inflammation is controversial. Here we evaluate the role of nonciliated secretoglobin ( Scgb1a1 )-expressing bronchiolar epithelial cells in RSV infection. Mice expressing a tamoxifen (TMX)-inducible Cre recombinase-estrogen receptor fusion protein (CreERTM) knocked into the Scgb1a1 locus were crossed with mice that harbor a RelA conditional allele ( RelA fl ), with loxP sites flanking exons 5 to 8 of the Rel homology domain. The Scgb1a1 CreERTM/+ × RelA fl/fl mouse is a RelA conditional knockout (RelA CKO ) of a nonciliated epithelial cell population enriched in the small bronchioles. TMX-treated RelA CKO mice have reduced pulmonary neutrophilic infiltration and impaired expression and secretion of NF-κB-dependent cytokines in response to RSV. In addition, RelA CKO mice had reduced expression levels of interferon (IFN) regulatory factor 1/7 (IRF1/7) and retinoic acid-inducible gene I (RIG-I), components of the mucosal IFN positive-feedback loop. We demonstrate that RSV replication induces RelA to complex with bromodomain-containing protein 4 (BRD4), a cofactor required for RNA polymerase II (Pol II) phosphorylation, activating the atypical histone acetyltransferase (HAT) activity of BRD4 required for phospho-Ser2 Pol II formation, histone H3K122 acetylation, and cytokine secretion in vitro and in vivo TMX-treated RelA CKO mice have less weight loss and reduced airway obstruction/hyperreactivity yet similar levels of IFN-γ production despite higher levels of virus production. These data indicate that the nonciliated Scgb1a1 -expressing epithelium is a major innate sensor for restricting RSV infection by mediating neutrophilic inflammation and chemokine and mucosal IFN production via the RelA-BRD4 pathway. IMPORTANCE RSV

Effects of the calcium ionophore A23187 on airway responsiveness to histamine and substance P in guinea pigs.

PubMed

Uno, D; Tsukagoshi, H; Hisada, T; Iwamae, S; Mori, M

1997-03-01

We evaluated the mechanism of the airway hyperresponsiveness (AHR) induced by a calcium ionophore in guinea pigs. Airway responsiveness to intravenous histamine (HS) and substance P (SP) was measured 24 h after a 1-h exposure to aerosolized A23187 (0.03 or 0.1 mg/ml) or its vehicle (10% DMSO). Changes were assessed by calculating -logPC350HS and logPC350SP. Neutral endopeptidase (NEP) activity in the airway tissues, as well as the nitrite (NO2) levels and the cell population in bronchoalveolar lavage fluid (BALF) was determined after measurement of pulmonary function. Changes in SP-induced vascular permeability 24 h after exposure to A23187 were measured by the Evans Blue dye extravasation technique. Exposure to A23187 caused a significant AHR to SP, along with a significant increase in the number of neutrophils and epithelial cells in the BALF. While there was no significant change in NEP activity in the airway tissues, the levels of nitrite in the BALF were significantly decreased in A23187-exposed animals. Significant correlations were found between the number of epithelial cells in the BALF and logPC350SP (r = 0.477, p < 0.05) and between nitrite levels in the BALF and -logPC350SP (r = 0.491, p < 0.05) A23187 exposure did not significantly change the SP-induced airway microvascular leakage. These data suggest that A23187 exposure induced AHR to SP possibly by reducing NO levels in the airway tissues. This may be due to damaged airway epithelium and/or NO breakdown by activated inflammatory cells in the airways of these guinea pigs.

Quantification of transcriptome responses of the rumen epithelium to butyrate infusion

USDA-ARS?s Scientific Manuscript database

Short-chain fatty acids (SCFAs), such as butyrate, produced by gut microorganisms play an important role in energy metabolism and physiology in ruminants as well as in human health. Butyrate is a preferred substrate in the rumen epithelium where approximately 90% of butyrate is metabolized. Additi...

Nicotine-induced activation of soluble adenylyl cyclase participates in ion transport regulation in mouse tracheal epithelium.

PubMed

Hollenhorst, Monika I; Lips, Katrin S; Kummer, Wolfgang; Fronius, Martin

2012-11-27

Functional nicotinic acetylcholine receptors (nAChR) have been identified in airway epithelia and their location in the apical and basolateral membrane makes them targets for acetylcholine released from neuronal and non-neuronal sources. One function of nAChR in airway epithelia is their involvement in the regulation of transepithelial ion transport by activation of chloride and potassium channels. However, the mechanisms underlying this nicotine-induced activation of ion transport are not fully elucidated. Thus, the aim of this study was to investigate the involvement of adenylyl cyclases in the nicotine-induced ion current in mouse tracheal epithelium. To evaluate the nicotine-mediated changes of transepithelial ion transport processes electrophysiological Ussing chamber measurements were applied and nicotine-induced ion currents were recorded in the absence and presence of adenylyl cyclase inhibitors. The ion current changes induced by nicotine (100 μM, apical) were not altered in the presence of high doses of atropine (25 μM, apical and basolateral), underlining the involvement of nAChR. Experiments with the transmembrane adenylyl cyclase inhibitor 2'5'-dideoxyadenosine (50 μM, apical and basolateral) and the soluble adenylyl cyclase inhibitor KH7 (10 μM, apical and basolateral) both reduced the nicotine-mediated ion current to a similar extent. Yet, a statistically significant reduction was obtained only in the experiments with KH7. This study indicates that nicotine binding to nAChR in mouse tracheal epithelium activates transepithelial ion transport involving adenylyl cyclase activity. This might be important for novel therapeutic strategies targeting epithelial ion transport mediated by the non-neuronal cholinergic system. Copyright © 2012 Elsevier Inc. All rights reserved.

FABP4 regulates eosinophil recruitment and activation in allergic airway inflammation.

PubMed

Ge, Xiao Na; Bastan, Idil; Dileepan, Mythili; Greenberg, Yana; Ha, Sung Gil; Steen, Kaylee A; Bernlohr, David A; Rao, Savita P; Sriramarao, P

2018-04-26

Fatty acid binding protein 4 (FABP4), a member of a family of lipid-binding proteins, is known to play a role in inflammation by virtue of its ability to regulate intracellular events such as lipid fluxes and signaling. Studies have indicated a pro-inflammatory role for FABP4 in allergic asthma, although its expression and function in eosinophils, the predominant inflammatory cells recruited to allergic airways, was not investigated. We examined expression of FABP4 in murine eosinophils and its role in regulating cell recruitment in vitro as well as in cockroach antigen (CRA)-induced allergic airway inflammation. CRA exposure led to airway recruitment of FABP4-expressing inflammatory cells, specifically eosinophils, in wild type (WT) mice. FABP4 expression in eosinophils was induced by TNF-α as well as IL-4 and IL-13. FABP4-deficient eosinophils exhibited markedly decreased cell spreading/formation of leading edges on vascular cell adhesion molecule-1 and significantly decreased adhesion to intercellular adhesion molecule-1 associated with reduced β2 integrin expression relative to WT cells. Further, FABP4-deficient eosinophils exhibited decreased migration, F-actin polymerization, calcium flux and ERK (1/2) phosphorylation in response to eotaxin-1. In vivo, CRA-challenged FABP4-deficient mice exhibited attenuated eosinophilia and significantly reduced airway inflammation (improved airway reactivity, lower IL-5, IL-13, TNFα and LTC4 levels, decreased airway structural changes) compared to WT mice. In conclusion, expression of FABP4 in eosinophils is induced during conditions of inflammation and plays a pro-inflammatory role in the development of allergic asthma by promoting eosinophil adhesion and migration and contributing to the development of various aspects of airway inflammation.

Influence of pirfenidone on airway hyperresponsiveness and inflammation in a Brown-Norway rat model of asthma.

PubMed

Mansoor, Jim K; Decile, Kendra C; Giri, Shri N; Pinkerton, Kent E; Walby, William F; Bratt, Jennifer M; Grewal, Harinder; Margolin, Solomon B; Schelegle, Edward S

2007-01-01

Pirfenidone was administered to sensitized Brown Norway rats prior to a series of ovalbumin challenges. Airway hyperresponsiveness, inflammatory cell infiltration, mucin and collagen content, and the degree of epithelium and smooth muscle staining for TGF-beta were examined in control, sensitized, and sensitized/challenged rats fed a normal diet or pirfenidone diet. Pirfenidone had no effect on airway hyperresponsiveness, but reduced distal bronchiolar cell infiltration and proximal and distal mucin content. Statistical analysis showed that the control group and sensitized/challenged pirfenidone diet group TGF-beta staining intensity scores were not significantly different from isotype controls, but that the staining intensity scores for the sensitized/challenged normal diet group was significantly different from isotype controls. These results suggest that pirfenidone treatment is effective in reducing some of the components of acute inflammation induced by allergen challenge.

Dimethylthiourea protects against chlorine induced changes in airway function in a murine model of irritant induced asthma.

PubMed

McGovern, Toby K; Powell, William S; Day, Brian J; White, Carl W; Govindaraju, Karuthapillai; Karmouty-Quintana, Harry; Lavoie, Normand; Tan, Ju Jing; Martin, James G

2010-10-06

Exposure to chlorine (Cl2) causes airway injury, characterized by oxidative damage, an influx of inflammatory cells and airway hyperresponsiveness. We hypothesized that Cl2-induced airway injury may be attenuated by antioxidant treatment, even after the initial injury. Balb/C mice were exposed to Cl2 gas (100 ppm) for 5 mins, an exposure that was established to alter airway function with minimal histological disruption of the epithelium. Twenty-four hours after exposure to Cl2, airway responsiveness to aerosolized methacholine (MCh) was measured. Bronchoalveolar lavage (BAL) was performed to determine inflammatory cell profiles, total protein, and glutathione levels. Dimethylthiourea (DMTU;100 mg/kg) was administered one hour before or one hour following Cl2 exposure. Mice exposed to Cl2 had airway hyperresponsiveness to MCh compared to control animals pre-treated and post-treated with DMTU. Total cell counts in BAL fluid were elevated by Cl2 exposure and were not affected by DMTU treatment. However, DMTU-treated mice had lower protein levels in the BAL than the Cl2-only treated animals. 4-Hydroxynonenal analysis showed that DMTU given pre- or post-Cl2 prevented lipid peroxidation in the lung. Following Cl2 exposure glutathione (GSH) was elevated immediately following exposure both in BAL cells and in fluid and this change was prevented by DMTU. GSSG was depleted in Cl2 exposed mice at later time points. However, the GSH/GSSG ratio remained high in chlorine exposed mice, an effect attenuated by DMTU. Our data show that the anti-oxidant DMTU is effective in attenuating Cl2 induced increase in airway responsiveness, inflammation and biomarkers of oxidative stress.

Abnormal epithelial structure and chronic lung inflammation after repair of chlorine-induced airway injury.

PubMed

Mo, Yiqun; Chen, Jing; Humphrey, David M; Fodah, Ramy A; Warawa, Jonathan M; Hoyle, Gary W

2015-01-15

Chlorine is a toxic gas used in a variety of industrial processes and is considered a chemical threat agent. High-level chlorine exposure causes acute lung injury, but the long-term effects of acute chlorine exposure are unclear. Here we characterized chronic pulmonary changes following acute chlorine exposure in mice. A/J mice were exposed to 240 parts per million-hour chlorine or sham-exposed to air. Chlorine inhalation caused sloughing of bronchial epithelium 1 day after chlorine exposure, which was repaired with restoration of a pseudostratified epithelium by day 7. The repaired epithelium contained an abnormal distribution of epithelial cells containing clusters of club or ciliated cells rather than the uniformly interspersed pattern of these cells in unexposed mice. Although the damaged epithelium in A/J mice was repaired rapidly, and minimal airway fibrosis was observed, chlorine-exposed mice developed pneumonitis characterized by infiltration of alveoli with neutrophils and prominent, large, foamy macrophages. Levels of CXCL1/KC, CXCL5/LPS-induced CXC chemokine, granulocyte colony-stimulating factor, and VEGF in bronchoalveolar (BAL) fluid from chlorine-exposed mice showed steadily increasing trends over time. BAL protein levels were increased on day 4 and remained elevated out to day 28. The number of bacteria cultured from lungs of chlorine-exposed mice 4 wk after exposure was not increased compared with sham-exposed mice, indicating that the observed pneumonitis was not driven by bacterial infection of the lung. The results indicate that acute chlorine exposure may cause chronic abnormalities in the lungs despite rapid repair of injured epithelium. Copyright © 2015 the American Physiological Society.

The contribution of airway smooth muscle to airway narrowing and airway hyperresponsiveness in disease.

PubMed

Martin, J G; Duguet, A; Eidelman, D H

2000-08-01

Airway hyperresponsiveness (AHR), the exaggerated response to constrictor agonists in asthmatic subjects, is incompletely understood. Changes in either the quantity or properties of airway smooth muscle (ASM) are possible explanations for AHR. Morphometric analyses demonstrate structural changes in asthmatic airways, including subepithelial fibrosis, gland hyperplasia/hypertrophy, neovascularization and an increase in ASM mass. Mathematical modelling of airway narrowing suggests that, of all the changes in structure, the increase in ASM mass is the most probable cause of AHR. An increase in ASM mass in the large airways is more closely associated with a greater likelihood of dying from asthma than increases in ASM mass in other locations within the airway tree. ASM contraction is opposed by the elastic recoil of the lungs and airways, which appears to limit the degree of bronchoconstriction in vivo. The cyclical nature of tidal breathing applies stresses to the airway wall that enhance the bronchodilating influence of the lung tissues on the contracting ASM, in all probability by disrupting cross-bridges. However, the increase in ASM mass in asthma may overcome the limitation resulting from the impedances to ASM shortening imposed by the lung parenchyma and airway wall tissues. Additionally, ASM with the capacity to shorten rapidly may achieve shorter lengths and cause a greater degree of bronchoconstriction when stimulated to contract than slower ASM. Changes in ASM properties are induced by the process of sensitization and allergen-exposure such as enhancement of phospholipase C activity and inositol phosphate turnover, and increases in myosin light chain kinase activity. Whether changes in ASM mass or biochemical/biomechanical properties form the basis for asthma remains to be determined.

Airway-parenchymal interdependence

PubMed Central

Paré, Peter D; Mitzner, Wayne

2015-01-01

In this manuscript we discuss the interaction of the lung parenchyma and the airways as well as the physiological and pathophysiological significance of this interaction. These two components of the respiratory organ can be thought of as two independent elastic structures but in fact the mechanical properties of one influence the behavior of the other. Traditionally the interaction has focused on the effects of the lung on the airways but there is good evidence that the opposite is also true, i.e., that the mechanical properties of the airways influence the elastic properties of the parenchyma. The interplay between components of the respiratory system including the airways, parenchyma and vasculature is often referred to as “interdependence.” This interdependence transmits the elastic recoil of the lung to create an effective pressure that dilates the airways as transpulmonary pressure and lung volume increase. By using a continuum mechanics analysis of the lung parenchyma, it is possible to predict the effective pressure between the airways and parenchyma, and these predictions can be empirically evaluated. Normal airway caliber is maintained by this pressure in the adventitial interstitium of the airway, and it counteracts airway compression during forced expiration as well as the ability of airway smooth muscle to narrow airways. Interdependence has physiological and pathophysiological significance. Weakening of the forces of interdependence contributes to airway dysfunction and gas exchange impairment in acute and chronic airway diseases including asthma and emphysema. PMID:23723029

Does personality play a role in continuous positive airway pressure compliance?

PubMed Central

Maschauer, Emily L.; Fairley, Donna M.

2017-01-01

Key points Continuous positive airway pressure (CPAP) adherence is low among individuals with obstructive sleep apnoea. Type D personality and high scores on the depression and hypochondriasis scales on the Minnesota Multiphasic Personality Inventory (MMPI) have been identified as factors contributing to non-compliance with CPAP. Further research into personality type may assist in understanding why some people adhere to CPAP, while others fail. Obstructive sleep apnoea (OSA) is a condition characterised by repetitive, intermittent partial or complete collapse/obstruction of the upper airway during sleep. Continuous positive airway pressure (CPAP) is highly efficacious in treating OSA but its effectiveness is limited due to suboptimal acceptance and adherence rates, with as many as 50% of OSA patients discontinuing CPAP treatment within the first year. Until recently, research has focused on examining mechanistic and demographic factors that could explain nonadherence (e.g. age, sex, race and education level) with limited applicability in a prospective or clinical manner. More recent research has focused on personality factors or types of patients with OSA who comply and do not comply with CPAP adherence in an attempt to enhance the accuracy of predicting treatment compliance. Type D personality has been found to be prevalent in one third of patients with OSA. The presence of Type D personality increases noncompliance and poor treatment outcomes due to negative affectivity, social inhibition, unhealthy lifestyle, and a reluctance to consult and/or follow medical advice. Conversely, individuals who are more likely to adhere to CPAP treatment tend to have a high internal locus of control and high self-efficacy, self-refer for treatment, and have active coping skills. By assessing personality and coping skills, the clinician may gain insight into the likelihood of a patient’s adherence to treatment. If the patient displays potential risk factors for CPAP

Transforming Growth Factor β1 Function in Airway Remodeling and Hyperresponsiveness. The Missing Link?

PubMed

Ojiaku, Christie A; Yoo, Edwin J; Panettieri, Reynold A

2017-04-01

The pathogenesis of asthma includes a complex interplay among airway inflammation, hyperresponsiveness, and remodeling. Current evidence suggests that airway structural cells, including bronchial smooth muscle cells, myofibroblasts, fibroblasts, and epithelial cells, mediate all three aspects of asthma pathogenesis. Although studies show a connection between airway remodeling and changes in bronchomotor tone, the relationship between the two remains unclear. Transforming growth factor β1 (TGF-β1), a growth factor elevated in the airway of patients with asthma, plays a role in airway remodeling and in the shortening of various airway structural cells. However, the role of TGF-β1 in mediating airway hyperresponsiveness remains unclear. In this review, we summarize the literature addressing the role of TGF-β1 in airway remodeling and shortening. Through our review, we aim to further elucidate the role of TGF-β1 in asthma pathogenesis and the link between airway remodeling and airway hyperresponsiveness in asthma and to define TGF-β1 as a potential therapeutic target for reducing asthma morbidity and mortality.

S100A8 protein attenuates airway hyperresponsiveness by suppressing the contraction of airway smooth muscle.

PubMed

Xu, Yu-Dong; Wang, Yu; Yin, Lei-Miao; Park, Gyoung-Hee; Ulloa, Luis; Yang, Yong-Qing

2017-02-26

Airway hyperresponsiveness (AHR) is a major clinical problem in allergic asthma mainly caused by the hypercontractility of airway smooth muscles (ASM). S100A8 is an important member of the S100 calcium-binding protein family with a potential to regulate cell contractility. Here, we analyze the potential of S100A8 to regulate allergen-induced AHR and ASM contraction. Treatment with recombinant S100A8 (rS100A8) diminished airway hyperresponsiveness in OVA-sensitized rats. ASM contraction assays showed that rS100A8 reduced hypercontractility in both isolated tracheal rings and primary ASM cells treated by acetylcholine. rS100A8 markedly rescued the phosphorylation level of myosin light chain induced by acetylcholine in ASM cells. These results show that rS100A8 plays a protective role in regulating AHR in asthma by inhibiting ASM contraction. These results support S100A8 as a novel therapeutic target to control ASM contraction in asthma. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

LYSOSOMAL FRACTIONS FROM TRANSITIONAL EPITHELIUM

PubMed Central

Kanczak, Norbert M.; Krall, Joseph I.; Hayes, E. Russell; Elliott, Willard B.

1965-01-01

Histochemical data suggested that the so called lipoid granules of transitional epithelium in some species are equivalent to lysosomes. Scrapings of bovine and canine transitional epithelium were subjected to differential centrifugation to confirm this identification biochemically. Fractions of rat liver, the classic source of lysosomes, were also prepared by the same methods to compare with the fractions obtained from urinary epithelium. In contrast to rat liver, uroepithelial fractions with a high relative specific activity for hydrolases were sedimented before the heavy mitochondria. Microscopically, these fractions contained the highest proportion of lipoid granules. The size and sedimentation characteristics of lysosomes from transitional epithelium more closely resembled those of lysosomes derived from rat kidney than those isolated from liver. PMID:14326111

Increase of poorly proliferated p63+ /Ki67+ basal cells forming multiple layers in the aberrant remodeled epithelium in nasal polyps.

PubMed

Zhao, L; Li, Y Y; Li, C W; Chao, S S; Liu, J; Nam, H N; Dung, N T N; Shi, L; Wang, D Y

2017-06-01

Aberrant epithelial remodeling with the ectopic expression of p63 (basal cell markers) is an important pathologic phenomenon seen in chronically inflamed airway epithelium such as in nasal polyps (NPs). Biopsies were obtained from 55 NP patients and 18 healthy controls (inferior turbinate). Among NP patients, 15 were treated with oral and nasal steroids, so that two sets of NP biopsies were taken before and after the treatments. p63, Ki67, type IV β-tubulin, and cell cycle markers were investigated in these specimens. The number of p63 + cells is significantly higher in both hyperplastic (1.53-fold, P < 0.0001) and squamous metaplastic (2.02-fold, P < 0.0001) epithelium from NPs than from healthy controls. There are three types of proliferative basal cells (p63 + /Ki67 + ) which are in different phases of the cell cycle, such as G1 phase (type I cells), S to G2 phase (type II cells), and mitosis (type III cells). Of importance, some type I cells may arrest after proliferation although they may still be p63 + /Ki67 + . In healthy epithelium, the ratio of the type I and II cells is almost 50:50. However, less type II cells are found in hyperplastic epithelium (34.85%, P = 0.012) and in squamous metaplastic epithelium (30.77%, P = 0.02) together with the presence of type III cells (3.45%, P = 0.01). These findings were not changed after steroid treatments. An increase of poorly proliferated basal cells forming multiple layers, which may stain for basal cell markers but does not form a proper epidermal barrier, is an important histopathologic phenomenon in aberrant remodeled epithelium of NPs. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MTOR Suppresses Cigarette Smoke-Induced Epithelial Cell Death and Airway Inflammation in Chronic Obstructive Pulmonary Disease.

PubMed

Wang, Yong; Liu, Juan; Zhou, Jie-Sen; Huang, Hua-Qiong; Li, Zhou-Yang; Xu, Xu-Chen; Lai, Tian-Wen; Hu, Yue; Zhou, Hong-Bin; Chen, Hai-Pin; Ying, Song-Min; Li, Wen; Shen, Hua-Hao; Chen, Zhi-Hua

2018-04-15

Airway epithelial cell death and inflammation are pathological features of chronic obstructive pulmonary disease (COPD). Mechanistic target of rapamycin (MTOR) is involved in inflammation and multiple cellular processes, e.g., autophagy and apoptosis, but little is known about its function in COPD pathogenesis. In this article, we illustrate how MTOR regulates cigarette smoke (CS)-induced cell death, airway inflammation, and emphysema. Expression of MTOR was significantly decreased and its suppressive signaling protein, tuberous sclerosis 2 (TSC2), was increased in the airway epithelium of human COPD and in mouse lungs with chronic CS exposure. In human bronchial epithelial cells, CS extract (CSE) activated TSC2, inhibited MTOR, and induced autophagy. The TSC2-MTOR axis orchestrated CSE-induced autophagy, apoptosis, and necroptosis in human bronchial epithelial cells; all of which cooperatively regulated CSE-induced inflammatory cytokines IL-6 and IL-8 through the NF-κB pathway. Mice with a specific knockdown of Mtor in bronchial or alveolar epithelial cells exhibited significantly augmented airway inflammation and airspace enlargement in response to CS exposure, accompanied with enhanced levels of autophagy, apoptosis, and necroptosis in the lungs. Taken together, these data demonstrate that MTOR suppresses CS-induced inflammation and emphysema-likely through modulation of autophagy, apoptosis, and necroptosis-and thus suggest that activation of MTOR may represent a novel therapeutic strategy for COPD. Copyright © 2018 by The American Association of Immunologists, Inc.

Shared Gene Expression Alterations in Nasal and Bronchial Epithelium for Lung Cancer Detection.

PubMed

2017-07-01

We previously derived and validated a bronchial epithelial gene expression biomarker to detect lung cancer in current and former smokers. Given that bronchial and nasal epithelial gene expression are similarly altered by cigarette smoke exposure, we sought to determine if cancer-associated gene expression might also be detectable in the more readily accessible nasal epithelium. Nasal epithelial brushings were prospectively collected from current and former smokers undergoing diagnostic evaluation for pulmonary lesions suspicious for lung cancer in the AEGIS-1 (n = 375) and AEGIS-2 (n = 130) clinical trials and gene expression profiled using microarrays. All statistical tests were two-sided. We identified 535 genes that were differentially expressed in the nasal epithelium of AEGIS-1 patients diagnosed with lung cancer vs those with benign disease after one year of follow-up ( P  < .001). Using bronchial gene expression data from the AEGIS-1 patients, we found statistically significant concordant cancer-associated gene expression alterations between the two airway sites ( P  < .001). Differentially expressed genes in the nose were enriched for genes associated with the regulation of apoptosis and immune system signaling. A nasal lung cancer classifier derived in the AEGIS-1 cohort that combined clinical factors (age, smoking status, time since quit, mass size) and nasal gene expression (30 genes) had statistically significantly higher area under the curve (0.81; 95% confidence interval [CI] = 0.74 to 0.89, P  = .01) and sensitivity (0.91; 95% CI = 0.81 to 0.97, P  = .03) than a clinical-factor only model in independent samples from the AEGIS-2 cohort. These results support that the airway epithelial field of lung cancer-associated injury in ever smokers extends to the nose and demonstrates the potential of using nasal gene expression as a noninvasive biomarker for lung cancer detection. © The Author 2017. Published by Oxford

Correlative Ultratructural Investigations of Airway Epithelium Following Experimental Exposure to Defined Air Pollutants and Lifestyle Exposure to Tobacco Smoke

EPA Science Inventory

Context: Investigations of cell/molecular level effects of in vivo exposure of airway mucosa of experimental animals to common irritant gases have demonstrated structural and physiological changes reflective of breaches in epithelial barrier function, presence of inflammatory cel...

Role of Airway Recruitment and Derecruitment in Lung Injury

PubMed Central

Ghadiali, S. N.; Huang, Y.

2011-01-01

The mechanical forces generated during the ventilation of patients with acute lung injury causes significant lung damage and inflammation. Low-volume ventilation protocols are commonly used to prevent stretch-related injury that occurs at high lung volumes. However, the cyclic closure and reopening of pulmonary airways at low lung volumes, i.e., derecruitment and recruitment, also causes significant lung damage and inflammation. In this review, we provide an overview of how biomedical engineering techniques are being used to elucidate the complex physiological and biomechanical mechanisms responsible for cellular injury during recruitment/derecruitment. We focus on the development of multiscale, multiphysics computational models of cell deformation and injury during airway reopening. These models, and the corresponding in vitro experiments, have been used to both elucidate the basic mechanisms responsible for recruitment/derecruitment injury and to develop alternative therapies that make the epithelium more resistant to injury. For example, models and experiments indicate that fluidization of the cytoskeleton is cytoprotective and that changes in cytoskeletal structure and cell mechanics can be used to mitigate the mechanotransduction of oscillatory pressure into inflammatory signaling. The continued application of biomedical engineering techniques to the problem of recruitment/derecruitment injury may therefore lead to novel and more effective therapies. PMID:22011235

Humidification and heating of inhaled gas in patients with artificial airway. A narrative review.

PubMed

Plotnikow, Gustavo Adrián; Accoce, Matias; Navarro, Emiliano; Tiribelli, Norberto

2018-03-01

Instrumentation of the airways in critical patients (endotracheal tube or tracheostomy cannula) prevents them from performing their function of humidify and heating the inhaled gas. In addition, the administration of cold and dry medical gases and the high flows that patients experience during invasive and non-invasive mechanical ventilation generate an even worse condition. For this reason, a device for gas conditioning is needed, even in short-term treatments, to avoid potential damage to the structure and function of the respiratory epithelium. In the field of intensive therapy, the use of heat and moisture exchangers is common for this purpose, as is the use of active humidification systems. Acquiring knowledge about technical specifications and the advantages and disadvantages of each device is needed for proper use since the conditioning of inspired gases is a key intervention in patients with artificial airway and has become routine care. Incorrect selection or inappropriate configuration of a device can have a negative impact on clinical outcomes. The members of the Capítulo de Kinesiología Intensivista of the Sociedad Argentina de Terapia Intensiva conducted a narrative review aiming to show the available evidence regarding conditioning of inhaled gas in patients with artificial airways, going into detail on concepts related to the working principles of each one.

Mast cell mediators in citric acid-induced airway constriction of guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, C.-H.; Lai, Y.-L.

2005-08-15

We demonstrated previously that mast cells play an important role in citric acid (CA)-induced airway constriction. In this study, we further investigated the underlying mediator(s) for this type of airway constriction. At first, to examine effects caused by blocking agents, 67 young Hartley guinea pigs were divided into 7 groups: saline + CA; methysergide (serotonin receptor antagonist) + CA; MK-886 (leukotriene synthesis inhibitor) + CA; mepyramine (histamine H{sub 1} receptor antagonist) + CA; indomethacin (cyclooxygenase inhibitor) + CA; cromolyn sodium (mast cell stabilizer) + CA; and compound 48/80 (mast cell degranulating agent) + CA. Then, we tested whether leukotriene C{submore » 4} (LTC{sub 4}) or histamine enhances CA-induced airway constriction in compound 48/80-pretreated guinea pigs. We measured dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV{sub 0.1}) during either baseline or recovery period. In addition, we detected histamine level, an index of pulmonary mast cell degranulation, in bronchoalveolar lavage (BAL) samples. Citric acid aerosol inhalation caused decreases in Crs and FEV{sub 0.1}, indicating airway constriction in the control group. This airway constriction was significantly attenuated by MK-886, mepyramine, cromolyn sodium, and compound 48/80, but not by either methysergide or indomethacin. Both LTC{sub 4} and histamine infusion significantly increased the magnitude of CA-induced airway constriction in compound 48/80-pretreated guinea pigs. Citric acid inhalation caused significant increase in histamine level in the BAL sample, which was significantly suppressed by compound 48/80. These results suggest that leukotrienes and histamine originating from mast cells play an important role in CA inhalation-induced noncholinergic airway constriction.« less

Transduction of ferret airway epithelia using a pre-treatment and lentiviral gene vector.

PubMed

Cmielewski, Patricia; Farrow, Nigel; Donnelley, Martin; McIntyre, Chantelle; Penny-Dimri, Jahan; Kuchel, Tim; Parsons, David

2014-11-21

The safety and efficiency of gene therapies for cystic fibrosis (CF) need to be assessed in pre-clinical models. Using the normal ferret, this study sought to determine whether ferret airway epithelia could be transduced with a lysophosphatidylcholine (LPC) pre-treatment followed by a VSV-G pseudotyped HIV-1 based lentiviral (LV) vector, in preparation for future studies in CF ferrets. Six normal ferrets (7 -8 weeks old) were treated with a 150 μL LPC pre-treatment, followed one hour later by a 500 μL LV vector dose containing the LacZ transgene. LacZ gene expression in the conducting airways and lung was assessed by X-gal staining after 7 days. The presence of transduction in the lung, as well as off-target transduction in the liver, spleen and gonads, were assessed by qPCR. The levels of LV vector p24 protein bio-distribution in blood sera were assessed by ELISA at 0, 1, 3, 5 and 7 days. The dosing protocol was well tolerated. LacZ gene expression was observed en face in the trachea of all animals. Histology showed that ciliated and basal cells were transduced in the trachea, with rare LacZ transduced single cells noted in lung. p24 levels was not detectable in the sera of 5 of the 6 animals. The LacZ gene was not detected in the lung tissue and no off-target transduction was detected by qPCR. This study shows that ferret airway epithelia are transducible using our unique two-step pre-treatment and LV vector dosing protocol. We have identified a number of unusual anatomical factors that are likely to influence the level of transduction that can be achieved in ferret airways. The ability to transduce ferret airway epithelium is a promising step towards therapeutic LV-CFTR testing in a CF ferret model.

Progenitor Epithelium

PubMed Central

Marty-Santos, Leilani

2015-01-01

Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

Differential effects of cyclic and constant stress on ATP release and mucociliary transport by human airway epithelia

PubMed Central

Button, Brian; Picher, Maryse; Boucher, Richard C

2007-01-01

In the lungs, the first line of defence against bacterial infection is the thin layer of airway surface liquid (ASL) lining the airway surface. The superficial airway epithelium exhibits complex regulatory pathways that blend ion transport to adjust ASL volume to maintain proper mucociliary clearance (MCC). We hypothesized that stresses generated by airflow and transmural pressures during breathing govern ASL volume by regulating the rate of epithelial ATP release. Luminal ATP, via interactions with apical membrane P2-purinoceptors, regulates the balance of active ion secretion versus absorption to maintain ASL volume at optimal levels for MCC. In this study we tested the hypothesis that cyclic compressive stress (CCS), mimicking normal tidal breathing, regulates ASL volume in airway epithelia. Polarized tracheobronchial epithelial cultures from normal and cystic fibrosis (CF) subjects responded to a range of CCS by increasing the rate of ATP release. In normal airway epithelia, the CCS-induced increase in ASL ATP concentration was sufficient to induce purinoceptor-mediated increases in ASL height and MCC, via inhibition of epithelial Na+-channel-mediated Na+ absorption and stimulation of Cl− secretion through CFTR and the Ca2+-activated chloride channels. In contrast, static, non-oscillatory stress did not stimulate ATP release, ion transport or MCC, emphasizing the importance of rhythmic mechanical stress for airway defence. In CF airway cultures, which exhibit basal ASL depletion, CCS was partially effective, producing less ASL volume secretion than in normal cultures, but a level sufficient to restore MCC. The present data suggest that CCS may (1) regulate ASL volume in the normal lung and (2) improve clearance in the lungs of CF patients, potentially explaining the beneficial role of exercise in lung defence. PMID:17317749

Effect of a chemical chaperone, tauroursodeoxycholic acid, on HDM-induced allergic airway disease

PubMed Central

Siddesha, Jalahalli M.; Nakada, Emily M.; Mihavics, Bethany R.; Hoffman, Sidra M.; Rattu, Gurkiranjit K.; Chamberlain, Nicolas; Cahoon, Jonathon M.; Lahue, Karolyn G.; Daphtary, Nirav; Aliyeva, Minara; Chapman, David G.; Desai, Dhimant H.; Poynter, Matthew E.

2016-01-01

Endoplasmic reticulum (ER) stress-induced unfolded protein response plays a critical role in inflammatory diseases, including allergic airway disease. However, the benefits of inhibiting ER stress in the treatment of allergic airway disease are not well known. Herein, we tested the therapeutic potential of a chemical chaperone, tauroursodeoxycholic acid (TUDCA), in combating allergic asthma, using a mouse model of house dust mite (HDM)-induced allergic airway disease. TUDCA was administered during the HDM-challenge phase (preventive regimen), after the HDM-challenge phase (therapeutic regimen), or therapeutically during a subsequent HDM rechallenge (rechallenge regimen). In the preventive regimen, TUDCA significantly decreased HDM-induced inflammation, markers of ER stress, airway hyperresponsiveness (AHR), and fibrosis. Similarly, in the therapeutic regimen, TUDCA administration efficiently decreased HDM-induced airway inflammation, mucus metaplasia, ER stress markers, and AHR, but not airway remodeling. Interestingly, TUDCA administered therapeutically in the HDM rechallenge regimen markedly attenuated HDM-induced airway inflammation, mucus metaplasia, ER stress markers, methacholine-induced AHR, and airway fibrotic remodeling. These results indicate that the inhibition of ER stress in the lungs through the administration of chemical chaperones could be a valuable strategy in the treatment of allergic airway diseases. PMID:27154200

Peripheral Airway Smooth Muscle, but Not the Trachealis, Is Hypercontractile in an Equine Model of Asthma.

PubMed

Matusovsky, Oleg S; Kachmar, Linda; Ijpma, Gijs; Bates, Genevieve; Zitouni, Nedjma; Benedetti, Andrea; Lavoie, Jean-Pierre; Lauzon, Anne-Marie

2016-05-01

Heaves is a naturally occurring equine disease that shares many similarities with human asthma, including reversible antigen-induced bronchoconstriction, airway inflammation, and remodeling. The purpose of this study was to determine whether the trachealis muscle is mechanically representative of the peripheral airway smooth muscle (ASM) in an equine model of asthma. Tracheal and peripheral ASM of heaves-affected horses under exacerbation, or under clinical remission of the disease, and control horses were dissected and freed of epithelium to measure unloaded shortening velocity (Vmax), stress (force/cross-sectional area), methacholine effective concentration at which 50% of the maximum response is obtained, and stiffness. Myofibrillar Mg(2+)-ATPase activity, actomyosin in vitro motility, and contractile protein expression were also measured. Horses with heaves had significantly greater Vmax and Mg(2+)-ATPase activity in peripheral airway but not in tracheal smooth muscle. In addition, a significant correlation was found between Vmax and the time elapsed since the end of the corticosteroid treatment for the peripheral airways in horses with heaves. Maximal stress and stiffness were greater in the peripheral airways of the horses under remission compared with controls and the horses under exacerbation, potentially due to remodeling. Actomyosin in vitro motility was not different between controls and horses with heaves. These data demonstrate that peripheral ASM is mechanically and biochemically altered in heaves, whereas the trachealis behaves as in control horses. It is therefore conceivable that the trachealis muscle may not be representative of the peripheral ASM in human asthma either, but this will require further investigation.

Cell-to-Cell Contact and Nectin-4 Govern Spread of Measles Virus from Primary Human Myeloid Cells to Primary Human Airway Epithelial Cells.

PubMed

Singh, Brajesh K; Li, Ni; Mark, Anna C; Mateo, Mathieu; Cattaneo, Roberto; Sinn, Patrick L

2016-08-01

addition, we sought to determine which immune cells transfer MeV infectivity to the human airway epithelium. Our studies are based on two types of human primary cells: (i) myeloid cells generated from donated blood and (ii) well-differentiated airway epithelial cells derived from donor lungs. We show that different types of myeloid cells, i.e., monocyte-derived macrophages and dendritic cells, transfer infection to airway epithelial cells. Furthermore, cell-to-cell contact is an important component of successful MeV transfer. Our studies elucidate a mechanism by which the most contagious human respiratory virus is delivered to the airway epithelium. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Histone deacetylase inhibitors up-regulate LL-37 expression independent of toll-like receptor mediated signalling in airway epithelial cells.

PubMed

Liu, Quan; Liu, Juan; Roschmann, Kristina Irene Lisolette; van Egmond, Danielle; Golebski, Korneliusz; Fokkens, Wytske Johanna; Wang, Dehui; van Drunen, Cornelis Maria

2013-04-11

HDAC inhibitors have been proposed as anticancer agents. However, their roles in innate genes expression remain not well known. Cathelicidin LL-37 is one of the few human bactericidal peptides, but the regulation of histone acetylation on LL-37 expression in airway epithelium remains largely unknown. Therefore, we investigated the effects of two non-selective HDACi, trichostatin A (TSA) and sodium butyrate (SB), on the expression of the cathelicidin LL-37 in human airway epithelial cells. LL37 in human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells(PNEC) in response to HDAC inhibitors with or without poly (I:C) stimulation was assessed using real-time PCR and western blot. In parallel, IL-6 expression was evaluated by ELISA. Our results showed that HDAC inhibitors up-regulated LL-37 gene expression independent of poly (I:C) stimulation in PNEC as well as in NCI-H292 cells. HDAC inhibitors increased LL37 protein expression in NCI-H292 cells but not in PNEC. In addition, HDAC inhibitors significantly inhibited poly (I:C)-induced IL-6 production in both of the epithelial cells. In conclusion, HDAC inhibitors directly up-regulated LL-37 gene expression in human airway epithelial cells.

Histone deacetylase inhibitors up-regulate LL-37 expression independent of toll-like receptor mediated signalling in airway epithelial cells

PubMed Central

2013-01-01

HDAC inhibitors have been proposed as anticancer agents. However, their roles in innate genes expression remain not well known. Cathelicidin LL-37 is one of the few human bactericidal peptides, but the regulation of histone acetylation on LL-37 expression in airway epithelium remains largely unknown. Therefore, we investigated the effects of two non-selective HDACi, trichostatin A (TSA) and sodium butyrate (SB), on the expression of the cathelicidin LL-37 in human airway epithelial cells. LL37 in human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells(PNEC) in response to HDAC inhibitors with or without poly (I:C) stimulation was assessed using real-time PCR and western blot. In parallel, IL-6 expression was evaluated by ELISA. Our results showed that HDAC inhibitors up-regulated LL-37 gene expression independent of poly (I:C) stimulation in PNEC as well as in NCI-H292 cells. HDAC inhibitors increased LL37 protein expression in NCI-H292 cells but not in PNEC. In addition, HDAC inhibitors significantly inhibited poly (I:C)-induced IL-6 production in both of the epithelial cells. In conclusion, HDAC inhibitors directly up-regulated LL-37 gene expression in human airway epithelial cells. PMID:23577829

dNP2-ctCTLA-4 inhibits German cockroach extract-induced allergic airway inflammation and hyper-responsiveness via inhibition of Th2 responses

PubMed Central

Lim, Sangho; Ho Sohn, Jung; Koo, Ja-Hyun; Park, Jung-Won; Choi, Je-Min

2017-01-01

German cockroaches are major household allergens that can trigger allergic airway inflammatory diseases with sensitive T-cell responses. Although the use of immune modulatory biologics, such as antibodies, to mediate allergic responses has recently been examined, only systemic administration is available because of the size limitations on intranasal administration. Here we utilized a cell-permeable peptide, dNP2, to deliver the cytoplasmic domain of cytotoxic T-lymphocyte antigen-4 (ctCTLA-4) through the airway epithelium to modulate Th2 responses in a German cockroach extract (GCE)-induced allergic airway inflammation model. The intranasal delivery efficiency of the dNP2-dTomato protein to the lungs was higher in GCE-induced asthmatic lung parenchymal cells compared to the sham cells. Intranasal administration of the dNP2-ctCTLA-4 protein inhibited airway hyper-responsiveness and reduced airway inflammation and remodeling, including goblet cell metaplasia and collagen deposition around the bronchi. The number of infiltrated cells, including eosinophils, and the levels of IL-4, IL-5, IL-13 and IFN-γ in the lungs were significantly reduced, presumably owing to inhibition of Th2 differentiation. However, intranasal administration of CTLA4-Ig did not inhibit airway inflammation. These results collectively suggest that dNP2-ctCTLA-4 is an efficient intranasally applicable candidate biologic for treating allergic asthma. PMID:28775364

dNP2-ctCTLA-4 inhibits German cockroach extract-induced allergic airway inflammation and hyper-responsiveness via inhibition of Th2 responses.

PubMed

Lim, Sangho; Ho Sohn, Jung; Koo, Ja-Hyun; Park, Jung-Won; Choi, Je-Min

2017-08-04

German cockroaches are major household allergens that can trigger allergic airway inflammatory diseases with sensitive T-cell responses. Although the use of immune modulatory biologics, such as antibodies, to mediate allergic responses has recently been examined, only systemic administration is available because of the size limitations on intranasal administration. Here we utilized a cell-permeable peptide, dNP2, to deliver the cytoplasmic domain of cytotoxic T-lymphocyte antigen-4 (ctCTLA-4) through the airway epithelium to modulate Th2 responses in a German cockroach extract (GCE)-induced allergic airway inflammation model. The intranasal delivery efficiency of the dNP2-dTomato protein to the lungs was higher in GCE-induced asthmatic lung parenchymal cells compared to the sham cells. Intranasal administration of the dNP2-ctCTLA-4 protein inhibited airway hyper-responsiveness and reduced airway inflammation and remodeling, including goblet cell metaplasia and collagen deposition around the bronchi. The number of infiltrated cells, including eosinophils, and the levels of IL-4, IL-5, IL-13 and IFN-γ in the lungs were significantly reduced, presumably owing to inhibition of Th2 differentiation. However, intranasal administration of CTLA4-Ig did not inhibit airway inflammation. These results collectively suggest that dNP2-ctCTLA-4 is an efficient intranasally applicable candidate biologic for treating allergic asthma.

Bronchoscopic assessment of airway retention time of aerosolized xylitol

PubMed Central

Durairaj, Lakshmi; Neelakantan, Srividya; Launspach, Janice; Watt, Janet L; Allaman, Margaret M; Kearney, William R; Veng-Pedersen, Peter; Zabner, Joseph

2006-01-01

Background Human airway surface liquid (ASL) has abundant antimicrobial peptides whose potency increases as the salt concentration decreases. Xylitol is a 5-carbon sugar that has the ability to lower ASL salt concentration, potentially enhancing innate immunity. Xylitol was detected for 8 hours in the ASL after application in airway epithelium in vitro. We tested the airway retention time of aerosolized iso-osmotic xylitol in healthy volunteers. Methods After a screening spirometry, volunteers received 10 ml of nebulized 5% xylitol. Bronchoscopy was done at 20 minutes (n = 6), 90 minutes (n = 6), and 3 hours (n = 5) after nebulization and ASL was collected using microsampling probes, followed by bronchoalveolar lavage (BAL). Xylitol concentration was measured by nuclear magnetic resonance spectroscopy and corrected for dilution using urea concentration. Results All subjects tolerated nebulization and bronchoscopy well. Mean ASL volume recovered from the probes was 49 ± 23 μl. The mean ASL xylitol concentration at 20, 90, and 180 minutes was 1.6 ± 1.9 μg/μl, 0.6 ± 0.6 μg/μl, and 0.1 ± 0.1 μg/μl, respectively. Corresponding BAL concentration corrected for dilution was consistently lower at all time points. The terminal half-life of aerosolized xylitol obtained by the probes was 45 minutes with a mean residence time of 65 minutes in ASL. Corresponding BAL values were 36 and 50 minutes, respectively. Conclusion After a single dose nebulization, xylitol was detected in ASL for 3 hours, which was shorter than our in vitro measurement. The microsampling probe performed superior to BAL when sampling bronchial ASL. PMID:16483382

Silibinin attenuates allergic airway inflammation in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Yun Ho; Jin, Guang Yu; Guo, Hui Shu

Highlights: Black-Right-Pointing-Pointer Silibinin diminishes ovalbumin-induced inflammatory reactions in the mouse lung. Black-Right-Pointing-Pointer Silibinin reduces the levels of various cytokines into the lung of allergic mice. Black-Right-Pointing-Pointer Silibinin prevents the development of airway hyperresponsiveness in allergic mice. Black-Right-Pointing-Pointer Silibinin suppresses NF-{kappa}B transcriptional activity. -- Abstract: Allergic asthma is a chronic inflammatory disease regulated by coordination of T-helper2 (Th2) type cytokines and inflammatory signal molecules. Silibinin is one of the main flavonoids produced by milk thistle, which is reported to inhibit the inflammatory response by suppressing the nuclear factor-kappa B (NF-{kappa}B) pathway. Because NF-{kappa}B activation plays a pivotal role in the pathogenesismore » of allergic inflammation, we have investigated the effect of silibinin on a mouse ovalbumin (OVA)-induced asthma model. Airway hyperresponsiveness, cytokines levels, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. Pretreatment of silibinin significantly inhibited airway inflammatory cell recruitment and peribronchiolar inflammation and reduced the production of various cytokines in bronchoalveolar fluid. In addition, silibinin prevented the development of airway hyperresponsiveness and attenuated the OVA challenge-induced NF-{kappa}B activation. These findings indicate that silibinin protects against OVA-induced airway inflammation, at least in part via downregulation of NF-{kappa}B activity. Our data support the utility of silibinin as a potential medicine for the treatment of asthma.« less

A study of airway smooth muscle in asthmatic and non-asthmatic airways using PS-OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Adams, David C.; Holz, Jasmin A.; Szabari, Margit V.; Hariri, Lida P.; Harris, R. Scott; Cho, Jocelyn L.; Hamilos, Daniel L.; Luster, Andrew D.; Medoff, Benjamin D.; Suter, Melissa J.

2016-03-01

Present understanding of the pathophysiological mechanisms of asthma has been severely limited by the lack of an imaging modality capable of assessing airway conditions of asthma patients in vivo. Of particular interest is the role that airway smooth muscle (ASM) plays in the development of asthma and asthma related symptoms. With standard Optical Coherence Tomography (OCT), imaging ASM is often not possible due to poor structural contrast between the muscle and surrounding tissues. A potential solution to this problem is to utilize additional optical contrast factors intrinsic to the tissue, such as birefringence. Due to its highly ordered structure, ASM is strongly birefringent. Previously, we demonstrated that Polarization Sensitive OCT(PS-OCT) has the potential to be used to visualize ASM as well as easily segment it from the surrounding (weakly) birefringent tissue by exploiting a property which allows it to discriminate the orientation of birefringent fibers. We have already validated our technology with a substantial set of histological comparisons made against data obtained ex vivo. In this work we present a comprehensive comparison of ASM distributions in asthmatic and non-asthmatic human volunteers. By isolating the ASM we parameterize its distribution in terms of both thickness and band width, calculated volumetrically over centimeters of airway. Using this data we perform analyses of the asthmatic and non-asthmatic airways using a broad number and variety and subjects.

Multitissue Transcriptomics Delineates the Diversity of Airway T Cell Functions in Asthma.

PubMed

Singhania, Akul; Wallington, Joshua C; Smith, Caroline G; Horowitz, Daniel; Staples, Karl J; Howarth, Peter H; Gadola, Stephan D; Djukanović, Ratko; Woelk, Christopher H; Hinks, Timothy S C

2018-02-01

Asthma arises from the complex interplay of inflammatory pathways in diverse cell types and tissues. We sought to undertake a comprehensive transcriptomic assessment of the epithelium and airway T cells that remain understudied in asthma and investigate interactions between multiple cells and tissues. Epithelial brushings and flow-sorted CD3 + T cells from sputum and BAL were obtained from healthy subjects (n = 19) and patients with asthma (mild, moderate, and severe asthma; n = 46). Gene expression was assessed using Affymetrix HT HG-U133 + PM GeneChips, and results were validated by real-time quantitative PCR. In the epithelium, IL-13 response genes (POSTN, SERPINB2, and CLCA1), mast cell mediators (CPA3 and TPSAB1), inducible nitric oxide synthase, and cystatins (CST1, CST2, and CST4) were upregulated in mild asthma, but, except for cystatins, were suppressed by corticosteroids in moderate asthma. In severe asthma-with predominantly neutrophilic phenotype-several distinct processes were upregulated, including neutrophilia (TCN1 and MMP9), mucins, and oxidative stress responses. The majority of the disease signature was evident in sputum T cells in severe asthma, where 267 genes were differentially regulated compared with health, highlighting compartmentalization of inflammation. This signature included IL-17-inducible chemokines (CXCL1, CXCL2, CXCL3, IL8, and CSF3) and chemoattractants for neutrophils (IL8, CCL3, and LGALS3), T cells, and monocytes. A protein interaction network in severe asthma highlighted signatures of responses to bacterial infections across tissues (CEACAM5, CD14, and TLR2), including Toll-like receptor signaling. In conclusion, the activation of innate immune pathways in the airways suggests that activated T cells may be driving neutrophilic inflammation and steroid-insensitive IL-17 response in severe asthma.

Ketamine relaxes airway smooth muscle contracted by endothelin.

PubMed

Sato, T; Matsuki, A; Zsigmond, E K; Rabito, S F

1997-04-01

Endothelins (ETs) are synthesized not only in vascular endothelial cells but also in airway epithelial cells. Increased ET-1 has been demonstrated in bronchial epithelium of asthmatic patients, and, in severe asthma attacks, ET-1 increases in plasma and bronchoalveolar lavage fluid. In this study, we investigated whether ketamine (KET) relaxes ET-induced tracheal contractions. Female guinea pigs were killed with an overdose of pentobarbital. The trachea was removed and cut spirally into two strips that were mounted in an organ bath filled with Krebs-bicarbonate buffer. The response of each strip to 10(-7) M carbachol was taken as 100% contraction to which the response to ET was referred. The contribution of the epithelium to the relaxant effect of KET was studied in denuded tracheae or in the presence of 5 x 10(-5) M indomethacin. ET-1 (3 x 10(-8) M) induced contractions that were 76 +/- 3% of those induced by carbachol. KET reversed the response to ET-1 in a dose-dependent fashion. Similarly, ET-2 (3 x 10(-8) M) induced contractions that were 74 +/- 5% of those induced by carbachol, and KET also reversed this response in a dose-dependent manner. In epithelium-denuded strips, ET-1 induced contractions that were 104 +/- 3% of those induced by carbachol, and KET still reversed this response. The tonic phase of the response to ET-1 was equal (100 +/- 6%) to the response to carbachol, and KET did not affect it significantly. In the presence of ryanodine, KET reduced the ET-1-induced contraction from 67 +/- 2% to 36 +/- 3.%, P < 0.01. In the presence of nicardipine, KET also inhibited the ET-1-induced contraction. We conclude that KET relaxes the tracheal smooth muscle contracted by ETs via a mechanism that is independent of the tracheal epithelium. The relaxant effect of KET on the ET-induced contraction of the trachealis muscle is not dependent upon blockade of 1) sarcolemma influx of Ca2+ through the dihydropyridine Ca2+ channel or 2) the release of intracellular Ca2

Effect of human rhinovirus infection on airway epithelium tight junction protein disassembly and transepithelial permeability.

PubMed

Looi, Kevin; Troy, Niamh M; Garratt, Luke W; Iosifidis, Thomas; Bosco, Anthony; Buckley, Alysia G; Ling, Kak-Ming; Martinovich, Kelly M; Kicic-Starcevich, Elizabeth; Shaw, Nicole C; Sutanto, Erika N; Zosky, Graeme R; Rigby, Paul J; Larcombe, Alexander N; Knight, Darryl A; Kicic, Anthony; Stick, Stephen M

2016-10-11

No studies have assessed the effects of human rhinovirus (HRV) infection on epithelial tight junctions (TJs) and resultant barrier function. To correlate viral infection with TJ disassembly, epithelial barrier integrity, and function. Human airway epithelial cells were infected with HRV minor serotype 1B (HRV-1B) at various 50% tissue culture infectivity doses (TCID 50 ) over 72 hours. HRV replication was assessed by quantitative-polymerase chain reaction (qPCR) while cell viability and apoptosis were assessed by proliferation and apoptotic assays, respectively. Protein expression of claudin-1, occludin, and zonula occludens protein-1 (ZO-1) was assessed using In-Cell™ Western assays. Transepithelial permeability assays were performed to assess effects on barrier functionality. RT 2 Profiler focused qPCR arrays and pathway analysis evaluating associations between human TJ and antiviral response were performed to identify potential interactions and pathways between genes of interests. HRV-1B infection affected viability that was both time and TCID 50 dependent. Significant increases in apoptosis and viral replication post-infection correlated with viral titer. Viral infection significantly decreased claudin-1 protein expression at the lower TCID 50 , while a significant decrease in all three TJ protein expressions occurred at higher TCID 50 . Decrease in protein expression was concomitant with significant increases in epithelial permeability of fluorescein isothiocynate labeled-dextran 4 and 20 kDa. Analysis of focused qPCR arrays demonstrated a significant decrease in ZO-1 gene expression. Furthermore, network analysis between human TJ and antiviral response genes revealed possible interactions and regulation of TJ genes via interleukin (IL)-15 in response to HRV-1B infection. HRV-1B infection directly alters human airway epithelial TJ expression leading to increased epithelial permeability potentially via an antiviral response of IL-15.

Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

NASA Astrophysics Data System (ADS)

Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

2006-03-01

Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

Electronic cigarette liquid increases inflammation and virus infection in primary human airway epithelial cells.

PubMed

Wu, Qun; Jiang, Di; Minor, Maisha; Chu, Hong Wei

2014-01-01

The use of electronic cigarettes (e-cigarettes) is rapidly increasing in the United States, especially among young people since e-cigarettes have been perceived as a safer alternative to conventional tobacco cigarettes. However, the scientific evidence regarding the human health effects of e-cigarettes on the lung is extremely limited. The major goal of our current study is to determine if e-cigarette use alters human young subject airway epithelial functions such as inflammatory response and innate immune defense against respiratory viral (i.e., human rhinovirus, HRV) infection. We examined the effects of e-cigarette liquid (e-liquid) on pro-inflammatory cytokine (e.g., IL-6) production, HRV infection and host defense molecules (e.g., short palate, lung, and nasal epithelium clone 1, SPLUNC1) in primary human airway epithelial cells from young healthy non-smokers. Additionally, we examined the role of SPLUNC1 in lung defense against HRV infection using a SPLUNC1 knockout mouse model. We found that nicotine-free e-liquid promoted IL-6 production and HRV infection. Addition of nicotine into e-liquid further amplified the effects of nicotine-free e-liquid. Moreover, SPLUNC1 deficiency in mice significantly increased lung HRV loads. E-liquid inhibited SPLUNC1 expression in primary human airway epithelial cells. These findings strongly suggest the deleterious health effects of e-cigarettes in the airways of young people. Our data will guide future studies to evaluate the impact of e-cigarettes on lung health in human populations, and help inform the public about potential health risks of e-cigarettes.

Postnatal remodeling of the neural components of the epithelial-mesenchymal trophic unit in the proximal airways of infant rhesus monkeys exposed to ozone and allergen.

PubMed

Larson, Shawnessy D; Schelegle, Edward S; Walby, William F; Gershwin, Laural J; Fanuccihi, Michelle V; Evans, Michael J; Joad, Jesse P; Tarkington, Brian K; Hyde, Dallas M; Plopper, Charles G

2004-02-01

Nerves and neuroendocrine cells located within the airway epithelium are ideally situated to sample a changing airway environment, to transmit that information to the central nervous system, and to promote trophic interactions between epithelial and mesenchymal cellular and acellular components. We tested the hypothesis that the environmental stresses of ozone (O(3)) and house dust mite allergen (HDMA) in atopic infant rhesus monkeys alter the distribution of airway nerves. Midlevel bronchi and bronchioles from 6-month-old infant monkeys that inhaled filtered air (FA), house dust mite allergen HDMA, O(3), or HDMA + O(3) for 11 episodes (5 days each, 0.5 ppm O(3), 8 h/day followed by 9 days recovery) were examined using immunohistochemistry for the presence of Protein gene product 9.5 (PGP 9.5), a nonspecific neural indicator, and calcitonin gene-related peptide (CGRP). Along the axial path between the sixth and the seventh intrapulmonary airway generations, there were small significant (P < 0.05) decrements in the density of epithelial nerves in monkeys exposed to HDMA or O(3), while in monkeys exposed to HDMA + O(3) there was a greater significant (P < 0.05) reduction in epithelial innervation. In animals exposed to O(3) or HDMA + O(3) there was a significant increase in the number of PGP 9.5 positive/CGRP negative cells that were anchored to the basal lamina and emitted projections in primarily the lateral plain and often intertwined with projections and cell bodies of other similar cells. We conclude that repeated cycles of acute injury and repair associated with the episodic pattern of ozone and allergen exposure alter the normal development of neural innervation of the epithelial compartment and the appearance of a new population of undefined PGP 9.5 positive cells within the epithelium.

Management of the Upper Airway in Cystic Fibrosis

PubMed Central

Illing, Elisa A.; Woodworth, Bradford A.

2015-01-01

Purpose of Review Upper airway disease engenders significant morbidity for patients with cystic fibrosis and is increasingly recognized as having a much greater role in pulmonary outcomes and quality of life than originally believed. Widespread disparate therapeutic strategies for cystic fibrosis chronic rhinosinusitis underscore the absence of a standardized treatment paradigm. This review outlines the most recent evidence-based trends in the management of upper airway disease in cystic fibrosis. Recent Findings The unified airway theory proposes that the sinuses are a focus of initial bacterial colonization which seeds the lower airway and may play a large role in maintaining lung infections. Mounting evidence suggests more aggressive treatment of the sinuses may confer significant improvement in pulmonary disease and quality of life outcomes in cystic fibrosis patients. However, there is a lack of high-level evidence regarding medical and surgical management of cystic fibrosis chronic rhinosinusitis that makes generalizations difficult. Summary Well designed clinical trials with long-term follow-up concerning medical and surgical interventions for cystic fibrosis sinus disease are required to establish standardized treatment protocols, but increased interest in the sinuses as a bacterial reservoir for pulmonary infections has generated considerable attention. PMID:25250804

Upper airway gene expression in smokers: the mouth as a "window to the soul" of lung carcinogenesis?

PubMed

Spira, Avrum

2010-03-01

This perspective on Boyle et al. (beginning on page 266 in this issue of the journal) explores transcriptomic profiling of upper airway epithelium as a biomarker of host response to tobacco smoke exposure. Boyle et al. have shown a striking relationship between smoking-related gene expression changes in the mouth and bronchus. This relationship suggests that buccal gene expression may serve as a relatively noninvasive surrogate marker of the physiologic response of the lung to tobacco smoke that could be used in large-scale screening and chemoprevention studies for lung cancer.

Diacetyl and 2,3-pentanedione exposure of human cultured airway epithelial cells: Ion transport effects and metabolism of butter flavoring agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaccone, Eric J.; Goldsmith, W. Travis; Shimko, Michael J.

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 ormore » 2,3-pentanedione vapors (25 or ≥ 60 ppm) and the effects on short circuit current and transepithelial resistance (R{sub t}) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na{sup +} transport, without affecting Cl{sup −} transport or Na{sup +},K{sup +}-pump activity. R{sub t} was unaffected. Na{sup +} 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. - Highlights: • Butter flavoring vapor effects on human cultured airway epithelium were studied. • Na transport was reduced by a 6-h exposure to 25 ppm diacetyl and 2,3-pentanedione. • Na transport recovered 18 h after exposure. • > 60 ppm transepithelial voltage and resistance were abolished; cells were damaged. • Cells metabolized diacetyl and 2,3-pentanedione

Terminal-Nerve-Derived Neuropeptide Y Modulates Physiological Responses in the Olfactory Epithelium of Hungry Axolotls (Ambystoma mexicanum)

PubMed Central

Mousley, Angela; Polese, Gianluca; Marks, Nikki J.; Eisthen, Heather L.

2007-01-01

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by L-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances. PMID:16855098

Terminal nerve-derived neuropeptide y modulates physiological responses in the olfactory epithelium of hungry axolotls (Ambystoma mexicanum).

PubMed

Mousley, Angela; Polese, Gianluca; Marks, Nikki J; Eisthen, Heather L

2006-07-19

The vertebrate brain actively regulates incoming sensory information, effectively filtering input and focusing attention toward environmental stimuli that are most relevant to the animal's behavioral context or physiological state. Such centrifugal modulation has been shown to play an important role in processing in the retina and cochlea, but has received relatively little attention in olfaction. The terminal nerve, a cranial nerve that extends underneath the lamina propria surrounding the olfactory epithelium, displays anatomical and neurochemical characteristics that suggest that it modulates activity in the olfactory epithelium. Using immunocytochemical techniques, we demonstrate that neuropeptide Y (NPY) is abundantly present in the terminal nerve in the axolotl (Ambystoma mexicanum), an aquatic salamander. Because NPY plays an important role in regulating appetite and hunger in many vertebrates, we investigated the possibility that NPY modulates activity in the olfactory epithelium in relation to the animal's hunger level. We therefore characterized the full-length NPY gene from axolotls to enable synthesis of authentic axolotl NPY for use in electrophysiological experiments. We find that axolotl NPY modulates olfactory epithelial responses evoked by l-glutamic acid, a food-related odorant, but only in hungry animals. Similarly, whole-cell patch-clamp recordings demonstrate that bath application of axolotl NPY enhances the magnitude of a tetrodotoxin-sensitive inward current, but only in hungry animals. These results suggest that expression or activity of NPY receptors in the olfactory epithelium may change with hunger level, and that terminal nerve-derived peptides modulate activity in the olfactory epithelium in response to an animal's changing behavioral and physiological circumstances.

Protective effects of valproic acid against airway hyperresponsiveness and airway remodeling in a mouse model of allergic airways disease.

PubMed

Royce, Simon G; Dang, William; Ververis, Katherine; De Sampayo, Nishika; El-Osta, Assam; Tang, Mimi L K; Karagiannis, Tom C

2011-12-01

Airway remodeling and airway hyperresponsiveness are major aspects of asthma pathology that are not targeted optimally by existing anti-inflammatory drugs. Histone deacetylase inhibitors have a wide range of effects that may potentially abrogate aspects of remodeling. One such histone deacetylase inhibitor is valproic acid (2-propylvaleric acid). Valproic acid is used clinically as an anti-epileptic drug and is a potent inhibitor of class I histone deacetylases but also inhibits class II histone deacetylases. We used valproic acid as a molecular model of histone deacetylase inhibition in vivo in chronic allergic airways disease mice with airway remodeling and airway hyperresponsiveness. Wild-type Balb/c mice with allergic airways disease were treated with valproic acid or vehicle control. Airway inflammation was assessed by bronchoalveolar lavage fluid cell counts and examination of lung tissue sections. Remodeling was assessed by morphometric analysis of histochemically stained slides and lung function was assessed by invasive plethysmography measurement of airway resistance. Valproic acid treatment did not affect inflammation parameters; however, valproic acid treatment resulted in reduced epithelial thickness as compared to vehicle treated mice (p < 0.01), reduced subepithelial collagen deposition (p < 0.05) and attenuated airway hyperresponsiveness (p < 0.05 and p < 0.01 for the two highest doses of methacholine, respectively). These findings show that treatment with valproic acid can reduce structural airway remodeling changes and hyperresponsiveness, providing further evidence for the potential use of histone deacetylase inhibitors for the treatment of asthma.

Airway stents

PubMed Central

Keyes, Colleen

2018-01-01

Stents and tubes to maintain the patency of the airways are commonly used for malignant obstruction and are occasionally employed in benign disease. Malignant airway obstruction usually results from direct involvement of bronchogenic carcinoma, or by extension of carcinomas occurring in the esophagus or the thyroid. External compression from lymph nodes or metastatic disease from other organs can also cause central airway obstruction. Most malignant airway lesions are surgically inoperable due to advanced disease stage and require multimodality palliation, including stent placement. As with any other medical device, stents have significantly evolved over the last 50 years and deserve an in-depth understanding of their true capabilities and complications. Not every silicone stent is created equal and the same holds for metallic stents. Herein, we present an overview of the topic as well as some of the more practical and controversial issues surrounding airway stents. We also try to dispel the myths surrounding stent removal and their supposed use only in central airways. At the end, we come to the long-held conclusion that stents should not be used as first line treatment of choice, but after ruling out the possibility of curative surgical resection or repair. PMID:29707506

Modelling airway smooth muscle passive length adaptation via thick filament length distributions

PubMed Central

Donovan, Graham M.

2013-01-01

We present a new model of airway smooth muscle (ASM), which surrounds and constricts every airway in the lung and thus plays a central role in the airway constriction associated with asthma. This new model of ASM is based on an extension of sliding filament/crossbridge theory, which explicitly incorporates the length distribution of thick sliding filaments to account for a phenomenon known as dynamic passive length adaptation; the model exhibits good agreement with experimental data for ASM force–length behaviour across multiple scales. Principally these are (nonlinear) force–length loops at short timescales (seconds), parabolic force–length curves at medium timescales (minutes) and length adaptation at longer timescales. This represents a significant improvement on the widely-used cross-bridge models which work so well in or near the isometric regime, and may have significant implications for studies which rely on crossbridge or other dynamic airway smooth muscle models, and thus both airway and lung dynamics. PMID:23721681

Nitric Oxide Promotes Airway Epithelial Wound Repair through Enhanced Activation of MMP-9

PubMed Central

Bove, Peter F.; Wesley, Umadevi V.; Greul, Anne-Katrin; Hristova, Milena; Dostmann, Wolfgang R.; van der Vliet, Albert

2007-01-01

The airway epithelium provides a protective barrier against inhaled environmental toxins and microorganisms, and epithelial injury initiates a number of processes to restore its barrier integrity, including activation of matrix metalloproteinases such as MMP-9 (92-kD gelatinase B). Airway epithelial cells continuously produce nitric oxide (NO), which has been linked to cell migration and MMP-9 regulation in several cell types, but the importance of epithelial NO in mediating airway epithelial repair or MMP-9 activation is unknown. Using primary or immortalized human bronchial epithelial cells, we demonstrate that low concentrations of NO promote epithelial cell migration and wound repair in an in vitro wound assay, which was associated with increased localized expression and activation of MMP-9. In addition, in HBE1 cells that were stably transfected with inducible NOS (NOS2), to mimic constitutive epithelial NOS2 expression in vivo, NOS inhibition decreased epithelial wound repair and MMP-9 expression. The stimulatory effects of NO on epithelial wound repair and MMP-9 expression were dependent on cGMP-mediated pathways and were inhibited by 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylyl cyclase. Inhibition of cGMP-dependent protein kinase (PKG) attenuated NO-mediated epithelial wound closure, but did not affect MMP-9 expression. However, pharmacologic MMP inhibition and siRNA knockdown of MMP-9 expression demonstrated the contribution of MMP-9 to NO-mediated wound closure. Overall, our results demonstrate that NOS2-derived NO contributes to airway epithelial repair by both PKG-dependent and -independent mechanisms, and involves NO-dependent expression and activation of MMP-9. PMID:16980554

Atopic asthmatic immune phenotypes associated with airway microbiota and airway obstruction.

PubMed

Turturice, Benjamin A; McGee, Halvor S; Oliver, Brian; Baraket, Melissa; Nguyen, Brian T; Ascoli, Christian; Ranjan, Ravi; Rani, Asha; Perkins, David L; Finn, Patricia W

2017-01-01

Differences in asthma severity may be related to inflammation in the airways. The lower airway microbiota has been associated with clinical features such as airway obstruction, symptom control, and response to corticosteroids. To assess the relationship between local airway inflammation, severity of disease, and the lower airway microbiota in atopic asthmatics. A cohort of young adult, atopic asthmatics with intermittent or mild/moderate persistent symptoms (n = 13) were assessed via bronchoscopy, lavage, and spirometry. These individuals were compared to age matched non-asthmatic controls (n = 6) and to themselves after six weeks of treatment with fluticasone propionate (FP). Inflammation of the airways was assessed via a cytokine and chemokine panel. Lower airway microbiota composition was determined by metagenomic shotgun sequencing. Unsupervised clustering of cytokines and chemokines prior to treatment with FP identified two asthmatic phenotypes (AP), termed AP1 and AP2, with distinct bronchoalveolar lavage inflammatory profiles. AP2 was associated with more obstruction, compared to AP1. After treatment with FP reduced MIP-1β and TNF-α and increased IL-2 was observed. A module of highly correlated cytokines that include MIP-1β and TNF-α was identified that negatively correlated with pulmonary function. Independently, IL-2 was positively correlated with pulmonary function. The airway microbiome composition correlated with asthmatic phenotypes. AP2, prior to FP treatment, was enriched with Streptococcus pneumoniae. Unique associations between IL-2 or the cytokine module and the microbiota composition of the airways were observed in asthmatics subjects prior to treatment but not after or in controls. The underlying inflammation in atopic asthma is related to the composition of microbiota and is associated with severity of airway obstruction. Treatment with inhaled corticosteroids was associated with changes in the airway inflammatory response to microbiota.

Humidification and heating of inhaled gas in patients with artificial airway. A narrative review

PubMed Central

Plotnikow, Gustavo Adrián; Accoce, Matias; Navarro, Emiliano; Tiribelli, Norberto

2018-01-01

Instrumentation of the airways in critical patients (endotracheal tube or tracheostomy cannula) prevents them from performing their function of humidify and heating the inhaled gas. In addition, the administration of cold and dry medical gases and the high flows that patients experience during invasive and non-invasive mechanical ventilation generate an even worse condition. For this reason, a device for gas conditioning is needed, even in short-term treatments, to avoid potential damage to the structure and function of the respiratory epithelium. In the field of intensive therapy, the use of heat and moisture exchangers is common for this purpose, as is the use of active humidification systems. Acquiring knowledge about technical specifications and the advantages and disadvantages of each device is needed for proper use since the conditioning of inspired gases is a key intervention in patients with artificial airway and has become routine care. Incorrect selection or inappropriate configuration of a device can have a negative impact on clinical outcomes. The members of the Capítulo de Kinesiología Intensivista of the Sociedad Argentina de Terapia Intensiva conducted a narrative review aiming to show the available evidence regarding conditioning of inhaled gas in patients with artificial airways, going into detail on concepts related to the working principles of each one. PMID:29742220

Efficient replication of the novel human betacoronavirus EMC on primary human epithelium highlights its zoonotic potential.

PubMed

Kindler, Eveline; Jónsdóttir, Hulda R; Muth, Doreen; Hamming, Ole J; Hartmann, Rune; Rodriguez, Regulo; Geffers, Robert; Fouchier, Ron A M; Drosten, Christian; Müller, Marcel A; Dijkman, Ronald; Thiel, Volker

2013-02-19

The recent emergence of a novel human coronavirus (HCoV-EMC) in the Middle East raised considerable concerns, as it is associated with severe acute pneumonia, renal failure, and fatal outcome and thus resembles the clinical presentation of severe acute respiratory syndrome (SARS) observed in 2002 and 2003. Like SARS-CoV, HCoV-EMC is of zoonotic origin and closely related to bat coronaviruses. The human airway epithelium (HAE) represents the entry point and primary target tissue for respiratory viruses and is highly relevant for assessing the zoonotic potential of emerging respiratory viruses, such as HCoV-EMC. Here, we show that pseudostratified HAE cultures derived from different donors are highly permissive to HCoV-EMC infection, and by using reverse transcription (RT)-PCR and RNAseq data, we experimentally determined the identity of seven HCoV-EMC subgenomic mRNAs. Although the HAE cells were readily responsive to type I and type III interferon (IFN), we observed neither a pronounced inflammatory cytokine nor any detectable IFN responses following HCoV-EMC, SARS-CoV, or HCoV-229E infection, suggesting that innate immune evasion mechanisms and putative IFN antagonists of HCoV-EMC are operational in the new host. Importantly, however, we demonstrate that both type I and type III IFN can efficiently reduce HCoV-EMC replication in HAE cultures, providing a possible treatment option in cases of suspected HCoV-EMC infection. IMPORTANCE A novel human coronavirus, HCoV-EMC, has recently been described to be associated with severe respiratory tract infection and fatalities, similar to severe acute respiratory syndrome (SARS) observed during the 2002-2003 epidemic. Closely related coronaviruses replicate in bats, suggesting that, like SARS-CoV, HCoV-EMC is of zoonotic origin. Since the animal reservoir and circumstances of zoonotic transmission are yet elusive, it is critically important to assess potential species barriers of HCoV-EMC infection. An important first

Circular flow patterns induced by ciliary activity in reconstituted human bronchial epithelium

NASA Astrophysics Data System (ADS)

Viallat, Annie; Khelloufi, Kamel; Gras, Delphine; Chanez, Pascal; Aix Marseille Univ., CNRS, CINaM, Marseille, France Team; Aix Marseille Univ., CNRS, Inserm, LAI, Marseille, France Team

2016-11-01

Mucociliary clearance is the transport at the surface of airways of a complex fluid layer, the mucus, moved by the beats of microscopic cilia present on epithelial ciliated cells. We explored the coupling between the spatial organisation and the activity of cilia and the transport of surface fluids on reconstituted cultures of human bronchial epithelium at air-liquid interface, obtained by human biopsies. We reveal the existence of stable local circular surface flow patterns of mucus or Newtonian fluid at the epithelium surface. We find a power law over more than 3 orders of magnitude showing that the average ciliated cell density controls the size of these flow patterns, and, therefore the distance over which mucus can be transported. We show that these circular flow patterns result from the radial linear increase of the local propelling forces (due to ciliary beats) on each flow domain. This linear increase of local forces is induced by a fine self-regulation of both cilia density and orientation of ciliary beats. Local flow domains grow and merge during ciliogenesis to provide macroscopic mucus transport. This is possible only when the viscoelastic mucus continuously exerts a shear stress on beating cilia, revealing a mechanosensitive function of cilia. M. K. Khelloufi thanks the society MedBioMed for financial support. This work was supported by the ANR MUCOCIL project, Grant ANR-13-BSV5-0015 of the French Agence Nationale de la Recherche.

Molecular Profiles for Lung Cancer Pathogenesis and Detection in U.S. Veterans

DTIC Science & Technology

2014-12-01

airway epithelium [1, 6, 7], and 2) these changes can be detected and serve as biomarker for early detection of lung cancer [8, 9], in the current...biospecimens from seven locations: nasal epithelium , proximal and distal bronchial airway epithelium obtained at bronchoscopy (ipsilateral and...contralateral to the tumor) as well as the tumor/benign lesion, adjacent normal parenchyma, and sub- segmental bronchial epithelium at time of lobectomy

Comparison of the effects of epithelium removal and of an enkephalinase inhibitor on the neurokinin-induced contractions of guinea-pig isolated trachea.

PubMed Central

Devillier, P.; Advenier, C.; Drapeau, G.; Marsac, J.; Regoli, D.

1988-01-01

1. The influence of epithelium removal and/or thiorphan on the effects of neurokinins (substance P (SP), neurokinin A (NKA), neurokinin B (NKB)) and related peptides on airway contractility was investigated on the guinea-pig isolated trachea. 2. Removing the tracheal epithelium significantly enhanced the sensitivity but not the maximum contractile responses to the peptides. 3. After removal of the epithelial layer, the shifts to the left of the log concentration response curves were greater for SP and SP-OMe (1.62 and 1.94 log units, respectively) than for two SP analogues substituted in position 9 namely [Pro9]SP sulfone and [beta-Ala4, Sar9]SP(4-11) sulfone (0.66 and 0.68 log units, respectively). The leftward shifts for compounds related to NKA or NKB lay between 0.58 and 0.73 log units. 4. The leftward shifts of the log concentration-response curves for SP, SP-OMe, [Pro9]SP sulfone, [beta-Ala4, Sar9]SP(4-11) sulfone and NKA were of similar magnitude after removal of the epithelium or after pretreatment with thiorphan (10(-5) M), an enkephalinase inhibitor, in the presence of epithelium. No significant additional shift of the curves to the left was observed with thiorphan plus epithelium removal. 5. The results obtained with the selective agonists for each of the three classes of neurokinin receptor (i.e NK1, NK2, NK3) suggest that the guinea-pig trachea contains receptors for SP and NKA but few if any for NKB. 6. It was concluded that neurokinins and related peptides (especially SP and analogues not substituted in position 9) are degraded by enkephalinase mainly located in the tracheal epithelium and that the addition of thiorphan or epithelium removal results in an inhibition or loss of enkephalinase activity, thereby increasing similarly the potencies of these peptides. It was, therefore, suggested that the supersensitivity to neurokinins produced by epithelium removal was due neither to the elimination of a permeability barrier nor to reduced production of a

A Comparative Immunohistochemical Study of Anal Canal Epithelium in Humans and Swine, Focusing on the Anal Transitional Zone Epithelium and the Anal Glands.

PubMed

Muranaka, Futoshi; Nakajima, Tomoyuki; Iwaya, Mai; Ishii, Keiko; Higuchi, Kayoko; Ogiwara, Naoko; Miyagawa, Shinichi; Ota, Hiroyoshi

2018-05-01

To better understand the cellular origins and differentiation of anal canal epithelial neoplasms, the immunohistochemical profiles of the anal canal epithelium in humans and swine were evaluated. Formalin-fixed tissue sections were immunostained for mucin (MUC: MUC2, MUC5AC, MUC5B), desmoglein 3 (DGS3), p63, CDX2, SOX2, and α-smooth muscle actin (α-SMA). The anal transitional zone (ATZ) epithelium covered the anal sinus and consisted of a stratified epithelium with mucous cells interspersed within the surface lining. Anal glands opened into the anal sinus. Ducts and acini of intraepithelial or periepithelial mucous type were the main structures of human anal glands, whereas those of swine were compound tubuloacinar mixed glands. Distal to the ATZ epithelium, non-keratinized stratified squamous epithelium merged with the keratinized stratified squamous epithelium of the perianal skin. MUC5AC expression predominated over MUC5B expression in the ATZ epithelium, while MUC5B expression was higher in the anal glands. SOX2 was positive in the ATZ epithelium, anal glands, and squamous epithelium except in the perianal skin. In humans, DGS3 was expressed in the ATZ epithelium, anal gland ducts, and squamous epithelium. p63 was detected in the ATZ epithelium, anal glands, and squamous epithelium. Myoepithelial cells positive for α-SMA and p63 were present in the anal glands of swine. Colorectal columnar cells were MUC5B + /MUC2 + /CDX2 + /MUC5AC - /SOX2 - . The ATZ epithelium seems to be a distinctive epithelium, with morphological and functional features allowing smooth defecation. The MUC5AC + /SOX2 + /MUC2 - /CDX2 - profile of the ATZ epithelium and anal glands is a useful feature for diagnosing adenocarcinoma arising from these regions. Anat Rec, 301:796-805, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

PubMed

Schebesta, Karl; Hüpfl, Michael; Rössler, Bernhard; Ringl, Helmut; Müller, Michael P; Kimberger, Oliver

2012-06-01

Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

Rhinovirus disrupts the barrier function of polarized airway epithelial cells.

PubMed

Sajjan, Umadevi; Wang, Qiong; Zhao, Ying; Gruenert, Dieter C; Hershenson, Marc B

2008-12-15

Secondary bacterial infection following rhinovirus (RV) infection has been recognized in chronic obstructive pulmonary disease. We sought to understand mechanisms by which RV infection facilitates secondary bacterial infection. Primary human airway epithelial cells grown at air-liquid interface and human bronchial epithelial (16HBE14o-) cells grown as polarized monolayers were infected apically with RV. Transmigration of bacteria (nontypeable Haemophilus influenzae and others) was assessed by colony counting and transmission electron microscopy. Transepithelial resistance (R(T)) was measured by using a voltmeter. The distribution of zona occludins (ZO)-1 was determined by immunohistochemistry and immunoblotting. Epithelial cells infected with RV showed 2-log more bound bacteria than sham-infected cultures, and bacteria were recovered from the basolateral media of RV- but not sham-infected cells. Infection of polarized airway epithelial cell cultures with RV for 24 hours caused a significant decrease in R(T) without causing cell death or apoptosis. Ultraviolet-treated RV did not decrease R(T), suggesting a requirement for viral replication. Reduced R(T) was associated with increased paracellular permeability, as determined by flux of fluorescein isothiocyanate (FITC)-inulin. Neutralizing antibodies to tumor necrosis factor (TNF)-alpha, IFN-gamma and IL-1beta reversed corresponding cytokine-induced reductions in R(T) but not that induced by RV, indicating that the RV effect is independent of these proinflammatory cytokines. Confocal microscopy and immunoblotting revealed the loss of ZO-1 from tight junction complexes in RV-infected cells. Intranasal inoculation of mice with RV1B also caused the loss of ZO-1 from the bronchial epithelium tight junctions in vivo. RV facilitates binding, translocation, and persistence of bacteria by disrupting airway epithelial barrier function.

RGS4 Overexpression in Lung Attenuates Airway Hyperresponsiveness in Mice.

PubMed

Madigan, Laura A; Wong, Gordon S; Gordon, Elizabeth M; Chen, Wei-Sheng; Balenga, Nariman; Koziol-White, Cynthia J; Panettieri, Reynold A; Levine, Stewart J; Druey, Kirk M

2018-01-01

A cardinal feature of asthma is airway hyperresponsiveness (AHR) to spasmogens, many of which activate G protein-coupled receptors (GPCRs) on airway smooth muscle (ASM) cells. Asthma subtypes associated with allergy are characterized by eosinophilic inflammation in the lung due to the type 2 immune response to allergens and proinflammatory mediators that promote AHR. The degree to which intrinsic abnormalities of ASM contribute to this phenotype remains unknown. The regulators of G protein signaling (RGS) proteins are a large group of intracellular proteins that inhibit GPCR signaling pathways. RGS2- and RGS5-deficient mice develop AHR spontaneously. Although RGS4 is upregulated in ASM from patients with severe asthma, the effects of increased RGS4 expression on AHR in vivo are unknown. Here, we examined the impact of forced RGS4 overexpression in lung on AHR using transgenic (Tg) mice. Tg RGS4 was expressed in bronchial epithelium and ASM in vivo, and protein expression in lung was increased at least 4-fold in Tg mice compared with wild-type (WT) mice. Lung slices from Tg mice contracted less in response to the m3 muscarinic receptor agonist methacholine compared with the WT, although airway resistance in live, unchallenged mice of both strains was similar. Tg mice were partially protected against AHR induced by fungal allergen challenge due to weakened contraction signaling in ASM and reduced type 2 cytokine (IL-5 and IL-13) levels in Tg mice compared with the WT. These results provide support for the hypothesis that increasing RGS4 expression and/or function could be a viable therapeutic strategy for asthma.

Characterization of endocytosis and exocytosis of cationic nanoparticles in airway epithelium cells

NASA Astrophysics Data System (ADS)

Youta Dombu, Christophe; Kroubi, Maya; Zibouche, Rima; Matran, Regis; Betbeder, Didier

2010-09-01

A major challenge of drug delivery using colloids via the airway is to understand the mechanism implied in their interactions with epithelial cells. The purpose of this work was to characterize the process of endocytosis and exocytosis of cationic nanoparticles (NPs) made of maltodextrin which were developed as a delivery system for antigens in vaccine applications. Confocal microscopy demonstrated that these NP are rapidly endocytosed after as little as 3 min incubation, and that the endocytosis was also faster than NP binding since most of the NPs were found in the middle of the cells around the nuclei. A saturation limit was observed after a 40 min incubation, probably due to an equilibrium becoming established between endocytosis and exocytosis. Endocytosis was dramatically reduced at 4 °C compared with 37 °C, or by NaN3 treatment, both results suggesting an energy dependent process. Protamine pretreatment of the cells inhibited NPs uptake and we found that clathrin pathway is implied in their endocytosis. Cholesterol depletion increased NP uptake by 300% and this phenomenon was explained by the fact that cholesterol depletion totally blocked NP exocytosis. These results suggest that these cationic NPs interact with anionic sites, are quickly endocytosed via the clathrin pathway and that their exocytosis is cholesterol dependent, and are similar to those obtained in other studies with viruses such as influenza.

Acute Lung Injury and Persistent Small Airway Disease in a Rabbit Model of Chlorine Inhalation

PubMed Central

Musah, Sadiatu; Schlueter, Connie F.; Humphrey, David M.; Powell, Karen S.; Roberts, Andrew M.; Hoyle, Gary W.

2016-01-01

Chlorine is a pulmonary toxicant to which humans can be exposed through accidents or intentional releases. Acute effects of chlorine inhalation in humans and animal models have been well characterized, but less is known about persistent effects of acute, high-level chlorine exposures. In particular, animal models that reproduce the long-term effects suggested to occur in humans are lacking. Here, we report the development of a rabbit model in which both acute and persistent effects of chlorine inhalation can be assessed. Male New Zealand White rabbits were exposed to chlorine while the lungs were mechanically ventilated. After chlorine exposure, the rabbits were extubated and were allowed to survive for up to 24 h after exposure to 800 ppm chlorine for 4 min to study acute effects or up to 7 days after exposure to 400 ppm for 8 min to study longer term effects. Acute effects observed 6 or 24 h after inhalation of 800 ppm chlorine for 4 min included hypoxemia, pulmonary edema, airway epithelial injury, inflammation, altered baseline lung mechanics, and airway hyperreactivity to inhaled methacholine. Seven days after recovery from inhalation of 400 ppm chlorine for 8 min, rabbits exhibited mild hypoxemia, increased area of pressure-volume loops, and airway hyperreactivity. Lung histology 7 days after chlorine exposure revealed abnormalities in the small airways, including inflammation and sporadic bronchiolitis obliterans lesions. Immunostaining showed a paucity of club and ciliated cells in the epithelium at these sites. These results suggest that small airway disease may be an important component of persistent respiratory abnormalities that occur following acute chlorine exposure. This non-rodent chlorine exposure model should prove useful for studying persistent effects of acute chlorine exposure and for assessing efficacy of countermeasures for chlorine-induced lung injury. PMID:27913141

Acute lung injury and persistent small airway disease in a rabbit model of chlorine inhalation.

PubMed

Musah, Sadiatu; Schlueter, Connie F; Humphrey, David M; Powell, Karen S; Roberts, Andrew M; Hoyle, Gary W

2017-01-15

Chlorine is a pulmonary toxicant to which humans can be exposed through accidents or intentional releases. Acute effects of chlorine inhalation in humans and animal models have been well characterized, but less is known about persistent effects of acute, high-level chlorine exposures. In particular, animal models that reproduce the long-term effects suggested to occur in humans are lacking. Here, we report the development of a rabbit model in which both acute and persistent effects of chlorine inhalation can be assessed. Male New Zealand White rabbits were exposed to chlorine while the lungs were mechanically ventilated. After chlorine exposure, the rabbits were extubated and were allowed to survive for up to 24h after exposure to 800ppm chlorine for 4min to study acute effects or up to 7days after exposure to 400ppm for 8min to study longer term effects. Acute effects observed 6 or 24h after inhalation of 800ppm chlorine for 4min included hypoxemia, pulmonary edema, airway epithelial injury, inflammation, altered baseline lung mechanics, and airway hyperreactivity to inhaled methacholine. Seven days after recovery from inhalation of 400ppm chlorine for 8min, rabbits exhibited mild hypoxemia, increased area of pressure-volume loops, and airway hyperreactivity. Lung histology 7days after chlorine exposure revealed abnormalities in the small airways, including inflammation and sporadic bronchiolitis obliterans lesions. Immunostaining showed a paucity of club and ciliated cells in the epithelium at these sites. These results suggest that small airway disease may be an important component of persistent respiratory abnormalities that occur following acute chlorine exposure. This non-rodent chlorine exposure model should prove useful for studying persistent effects of acute chlorine exposure and for assessing efficacy of countermeasures for chlorine-induced lung injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Inhibition of neutrophil elastase attenuates airway hyperresponsiveness and inflammation in a mouse model of secondary allergen challenge: neutrophil elastase inhibition attenuates allergic airway responses

PubMed Central

2013-01-01

Background Chronic asthma is often associated with neutrophilic infiltration in the airways. Neutrophils contain elastase, a potent secretagogue in the airways, nonetheless the role for neutrophil elastase as well as neutrophilic inflammation in allergen-induced airway responses is not well defined. In this study, we have investigated the impact of neutrophil elastase inhibition on the development of allergic airway inflammation and airway hyperresponsiveness (AHR) in previously sensitized and challenged mice. Methods BALB/c mice were sensitized and challenged (primary) with ovalbumin (OVA). Six weeks later, a single OVA aerosol (secondary challenge) was delivered and airway inflammation and airway responses were monitored 6 and 48 hrs later. An inhibitor of neutrophil elastase was administered prior to secondary challenge. Results Mice developed a two-phase airway inflammatory response after secondary allergen challenge, one neutrophilic at 6 hr and the other eosinophilic, at 48 hr. PAR-2 expression in the lung tissues was enhanced following secondary challenge, and that PAR-2 intracellular expression on peribronchial lymph node (PBLN) T cells was also increased following allergen challenge of sensitized mice. Inhibition of neutrophil elastase significantly attenuated AHR, goblet cell metaplasia, and inflammatory cell accumulation in the airways following secondary OVA challenge. Levels of IL-4, IL-5 and IL-13, and eotaxin in BAL fluid 6 hr after secondary allergen challenge were significantly suppressed by the treatment. At 48 hr, treatment with the neutrophil elastase inhibitor significantly reduced the levels of IL-13 and TGF-β1 in the BAL fluid. In parallel, in vitro IL-13 production was significantly inhibited in spleen cells from sensitized mice. Conclusion These data indicate that neutrophil elastase plays an important role in the development of allergic airway inflammation and hyperresponsiveness, and would suggest that the neutrophil elastase inhibitor

Airway Humidification Reduces the Inflammatory Response During Mechanical Ventilation.

PubMed

Jiang, Min; Song, Jun-Jie; Guo, Xiao-Li; Tang, Yong-Lin; Li, Hai-Bo

2015-12-01

Currently, no clinical or animal studies have been performed to establish the relationship between airway humidification and mechanical ventilation-induced lung inflammatory responses. Therefore, an animal model was established to better define this relationship. Rabbits (n = 40) were randomly divided into 6 groups: control animals, sacrificed immediately after anesthesia (n = 2); dry gas group animals, subjected to mechanical ventilation for 8 h without humidification (n = 6); and experimental animals, subjected to mechanical ventilation for 8 h under humidification at 30, 35, 40, and 45°C, respectively (n = 8). Inflammatory cytokines in the bronchi alveolar lavage fluid (BALF) were measured. The integrity of the airway cilia and the tracheal epithelium was examined by scanning and transmission electron microscopy, respectively. Peripheral blood white blood cell counts and the wet to dry ratio and lung pathology were determined. Dry gas group animals showed increased tumor necrosis factor alpha levels in BALF compared with control animals (P < .05). The tumor necrosis factor alpha and interleukin-8 levels in the BALF reached baseline levels when the humidification temperature was increased to 40°C. Scanning and transmission electron microscopy analysis revealed that cilia integrity was maintained in the 40°C groups. Peripheral white blood cell counts were not different among those groups. Compared with control animals, the wet to dry ratio was significantly elevated in the dry gas group (P < .05). Moreover, humidification at 40°C resulted in reduced pathologic injury compared with the other groups based on the histologic score. Pathology and reduced inflammation observed in animals treated at 40°C was similar to that observed in the control animals, suggesting that appropriate humidification reduced inflammatory responses elicited as a consequence of mechanical ventilation, in addition to reducing damage to the cilia and reducing water loss in the airway

Spatiotemporal expression of Ezh2 in the developing mouse cochlear sensory epithelium.

PubMed

Chen, Yan; Li, Wenyan; Li, Wen; Chai, Renjie; Li, Huawei

2016-09-01

The enhancer of zeste 2 polycomb repressive complex 2 subunit (Ezh2) is a histone-lysine Nmethyltransferase enzyme that participates in DNA methylation. Ezh2 has also been reported to play crucial roles in stem cell proliferation and differentiation. However, the detailed expression profile of Ezh2 during mouse cochlear development has not been investigated. Here, we examined the spatiotemporal expression of Ezh2 in the cochlea during embryonic and postnatal development. Ezh2 expression began to be observed in the whole otocyst nuclei at embryonic day 9.5 (E9.5). At E12.5, Ezh2 was expressed in the nuclei of the cochlear prosensory epithelium. At E13.5 and E15.5, Ezh2 was expressed from the apical to the basal turns in the nuclei of the differentiating cochlear epithelium. At postnatal day (P) 0 and 7, the Ezh2 expression was located in the nuclei of the cochlear epithelium in all three turns and could be clearly seen in outer and inner hair cells, supporting cells, the stria vascularis, and spiral ganglion cells. Ezh2 continued to be expressed in the cochlear epithelium of adult mice. Our results provide the basic Ezh2 expression pattern and might be useful for further investigating the detailed role of Ezh2 during cochlear development.

Parasympathetic Control of Airway Submucosal Glands: Central Reflexes and the Airway Intrinsic Nervous System

PubMed Central

Wine, Jeffrey J.

2007-01-01

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences

CCAAT/Enhancer Binding Protein–α Regulates the Protease/Antiprotease Balance Required for Bronchiolar Epithelium Regeneration

PubMed Central

Sato, Atsuyasu; Xu, Yan; Whitsett, Jeffrey A.

2012-01-01

Many transcription factors that regulate lung morphogenesis during development are reactivated to mediate repairs of the injured adult lung. We hypothesized that CCAAT/enhancer binding protein–α (C/EBPα), a transcription factor critical for perinatal lung maturation, regulates genes required for the normal repair of the bronchiolar epithelium after injury. Transgenic CebpαΔ/Δ mice, in which Cebpa was conditionally deleted from Clara cells and Type II cells after birth, were used in this study. Airway injury was induced in mice by the intraperitoneal administration of naphthalene to ablate bronchiolar epithelial cells. Although the deletion of C/EBPα did not influence lung structure and function under unstressed conditions, C/EBPα was required for the normal repair of terminal bronchiolar epithelium after naphthalene injury. To identify cellular processes that are influenced by C/EBPα during repair, mRNA microarray was performed on terminal bronchiolar epithelial cells isolated by laser-capture microdissection. Normal repair of the terminal bronchiolar epithelium was highly associated with the mRNAs regulating antiprotease activities, and their induction required C/EBPα. The defective deposition of fibronectin in CebpαΔ/Δ mice was associated with increased protease activity and delayed differentiation of FoxJ1-expressing ciliated cells. The fibronectin and ciliated cells were restored by the intratracheal treatment of CebpαΔ/Δ mice with the serine protease inhibitor. In conclusion, C/EBPα regulates the expression of serine protease inhibitors that are required for the normal increase of fibronectin and the restoration of ciliated cells after injury. Treatment with serine protease inhibitor may aid in the recovery of injured bronchiolar epithelial cells, and prevent common chronic lung diseases. PMID:22652201

Following damage, the majority of bone marrow-derived airway cells express an epithelial marker.

PubMed

MacPherson, Heather; Keir, Pamela A; Edwards, Carol J; Webb, Sheila; Dorin, Julia R

2006-12-19

Adult-derived bone marrow stem cells are capable of reconstituting the haematopoietic system. However there is ongoing debate in the literature as to whether bone marrow derived cells have the ability to populate other tissues and express tissue specific markers. The airway has been an organ of major interest and was one of the first where this was demonstrated. We have previously demonstrated that the mouse airway can be repopulated by side population bone marrow transplanted cells. Here we investigate the frequency and phenotypic nature of these bone marrow derived cells. Female mice were engrafted with male whole bone marrow or side population (SP) cells and subjected to detergent-induced damage after 3 months. Donor cells were identified by Y chromosome fluorescence in situ hybridisation and their phenotype was assessed by immunohistochemistry on the same sections. Slides were visualised by a combination of widefield and deconvolved microscopy and whole cells were analysed on cytospin preparations. The frequencies of engraftment of male cells in the airway of mice that show this (9/10), range from 1.0-1.6% with whole marrow and 0.6-1.5% with SP cells. Undamaged controls have only between 0.1 and 0.2% male cells in the trachea. By widefield microscopy analysis we find 60.2% (53/88) of male donor derived cells express cytokeratins as a marker of epithelial cells. These results were reinforced using deconvolved microscopy and scored by two independent investigators. In addition cytospin analysis of cells dissociated from the damaged trachea of engrafted mice also reveals donor derived Y chromosome positive cells that are immunopositive for cytokeratin. Using cytokeratin and the universal haematopoietic marker CD45 immunohistochemistry, we find the donor derived cells fall into four phenotypic classes. We do not detect cytokeratin positive cells in whole bone marrow using cytokeratin immunostaining and we do not detect any cytokeratin mRNA in SP or bone marrow

Ventilation heterogeneity is a major determinant of airway hyperresponsiveness in asthma, independent of airway inflammation

PubMed Central

Downie, Sue R; Salome, Cheryl M; Verbanck, Sylvia; Thompson, Bruce; Berend, Norbert; King, Gregory G

2007-01-01

Background Airway hyperresponsiveness is the ability of airways to narrow excessively in response to inhaled stimuli and is a key feature of asthma. Airway inflammation and ventilation heterogeneity have been separately shown to be associated with airway hyperresponsiveness. A study was undertaken to establish whether ventilation heterogeneity is associated with airway hyperresponsiveness independently of airway inflammation in subjects with asthma and to determine the effect of inhaled corticosteroids on this relationship. Methods Airway inflammation was measured in 40 subjects with asthma by exhaled nitric oxide, ventilation heterogeneity by multiple breath nitrogen washout and airway hyperresponsiveness by methacholine challenge. In 18 of these subjects with uncontrolled symptoms, measurements were repeated after 3 months of treatment with inhaled beclomethasone dipropionate. Results At baseline, airway hyperresponsiveness was independently predicted by airway inflammation (partial r2 = 0.20, p<0.001) and ventilation heterogeneity (partial r2 = 0.39, p<0.001). Inhaled corticosteroid treatment decreased airway inflammation (p = 0.002), ventilation heterogeneity (p = 0.009) and airway hyperresponsiveness (p<0.001). After treatment, ventilation heterogeneity was the sole predictor of airway hyperresponsiveness (r2 = 0.64, p<0.001). Conclusions Baseline ventilation heterogeneity is a strong predictor of airway hyperresponsiveness, independent of airway inflammation in subjects with asthma. Its persistent relationship with airway hyperresponsiveness following anti‐inflammatory treatment suggests that it is an important independent determinant of airway hyperresponsiveness. Normalisation of ventilation heterogeneity is therefore a potential goal of treatment that may lead to improved long‐term outcomes. PMID:17311839

Challenges and opportunities for tissue-engineering polarized epithelium.

PubMed

Paz, Ana C; Soleas, John; Poon, James C H; Trieu, Dennis; Waddell, Thomas K; McGuigan, Alison P

2014-02-01

The epithelium is one of the most important tissue types in the body and the specific organization of the epithelial cells in these tissues is important for achieving appropriate function. Since many tissues contain an epithelial component, engineering functional epithelium and understanding the factors that control epithelial maturation and organization are important for generating whole artificial organ replacements. Furthermore, disruption of the cellular organization leads to tissue malfunction and disease; therefore, engineered epithelium could provide a valuable in vitro model to study disease phenotypes. Despite the importance of epithelial tissues, a surprisingly limited amount of effort has been focused on organizing epithelial cells into artificial polarized epithelium with an appropriate structure that resembles that seen in vivo. In this review, we provide an overview of epithelial tissue organization and highlight the importance of cell polarization to achieve appropriate epithelium function. We next describe the in vitro models that exist to create polarized epithelium and summarize attempts to engineer artificial epithelium for clinical use. Finally, we highlight the opportunities that exist to translate strategies from tissue engineering other tissues to generate polarized epithelium with a functional structure.

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.

Structural and functional localization of airway effects from episodic exposure of infant monkeys to allergen and/or ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joad, Jesse P.; Kott, Kayleen S.; Bric, John M.

2006-08-01

Both allergen and ozone exposure increase asthma symptoms and airway responsiveness in children. Little is known about how these inhalants may differentially modify airway responsiveness in large proximal as compared to small distal airways. We evaluated whether bronchi and respiratory bronchioles from infant monkeys exposed episodically to allergen and/or ozone differentially develop intrinsic hyperresponsiveness to methacholine and whether eosinophils and/or pulmonary neuroendocrine cells play a role. Infant monkeys were exposed episodically for 5 months to: (1) filtered air, (2) aerosolized house dust mite allergen, (3) ozone 0.5 ppm, or (4) house dust mite allergen + ozone. Studying the function/structure relationshipmore » of the same lung slices, we evaluated methacholine airway responsiveness and histology of bronchi and respiratory bronchioles. In bronchi, intrinsic responsiveness was increased by allergen exposure, an effect reduced by bombesin antagonist. In respiratory bronchioles, intrinsic airway responsiveness was increased by allergen + ozone exposure. Eosinophils were increased by allergen and allergen + ozone exposure in bronchi and by allergen exposure in respiratory bronchioles. In both airways, exposure to allergen + ozone resulted in fewer tissue eosinophils than did allergen exposure alone. In bronchi, but not in respiratory bronchioles, the number of eosinophils and neuroendocrine cells correlated with airway responsiveness. We conclude that episodically exposing infant monkeys to house dust mite allergen with or without ozone increased intrinsic airway responsiveness to methacholine in bronchi differently than in respiratory bronchioles. In bronchi, eosinophils and neuroendocrine cells may play a role in the development of airway hyperresponsiveness.« less

Investigations of Pulmonary Epithelial Cell Damage due to Air-Liquid Interfacial Stresses in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Gaver, Donald P., III; Bilek, A. M.; Kay, S.; Dee, K. C.

2004-01-01

Pulmonary airway closure is a potentially dangerous event that can occur in microgravity environments and may result in limited gas exchange for flight crew during long-term space flight. Repetitive airway collapse and reopening subjects the pulmonary epithelium to large, dynamic, and potentially injurious mechanical stresses. During ventilation at low lung volumes and pressures, airway instability leads to repetitive collapse and reopening. During reopening, air must progress through a collapsed airway, generating stresses on the airway walls, potentially damaging airway tissues. The normal lung can tolerate repetitive collapse and reopening. However, combined with insufficient or dysfunctional pulmonary surfactant, repetitive airway collapse and reopening produces severe lung injury. Particularly at risk is the pulmonary epithelium. As an important regulator of lung function and physiology, the degree of pulmonary epithelial damage influences the course and outcome of lung injury. In this paper we present experimental and computational studies to explore the hypothesis that the mechanical stresses associated with airway reopening inflict injury to the pulmonary epithelium.

Alterations in Bronchial Airway miRNA Expression for Lung Cancer Detection.

PubMed

Pavel, Ana B; Campbell, Joshua D; Liu, Gang; Elashoff, David; Dubinett, Steven; Smith, Kate; Whitney, Duncan; Lenburg, Marc E; Spira, Avrum

2017-11-01

We have previously shown that gene expression alterations in normal-appearing bronchial epithelial cells can serve as a lung cancer detection biomarker in smokers. Given that miRNAs regulate airway gene expression responses to smoking, we evaluated whether miRNA expression is also altered in the bronchial epithelium of smokers with lung cancer. Using epithelial brushings from the mainstem bronchus of patients undergoing bronchoscopy for suspected lung cancer (as part of the AEGIS-1/2 clinical trials), we profiled miRNA expression via small-RNA sequencing from 347 current and former smokers for which gene expression data were also available. Patients were followed for one year postbronchoscopy until a final diagnosis of lung cancer ( n = 194) or benign disease ( n = 153) was made. Following removal of 6 low-quality samples, we used 138 patients (AEGIS-1) as a discovery set to identify four miRNAs (miR-146a-5p, miR-324-5p, miR-223-3p, and miR-223-5p) that were downregulated in the bronchial airway of lung cancer patients (ANOVA P < 0.002, FDR < 0.2). The expression of these miRNAs is significantly more negatively correlated with the expression of their mRNA targets than with the expression of other nontarget genes (K-S P < 0.05). Furthermore, these mRNA targets are enriched among genes whose expression is elevated in cancer patients (GSEA FDR < 0.001). Finally, we found that the addition of miR-146a-5p to an existing mRNA biomarker for lung cancer significantly improves its performance (AUC) in the 203 samples (AEGIS-1/2) serving an independent test set (DeLong P < 0.05). Our findings suggest that there are miRNAs whose expression is altered in the cytologically normal bronchial epithelium of smokers with lung cancer, and that they may regulate cancer-associated gene expression differences. Cancer Prev Res; 10(11); 651-9. ©2017 AACR . ©2017 American Association for Cancer Research.

Does Inhalation of Virgin Coconut Oil Accelerate Reversal of Airway Remodelling in an Allergic Model of Asthma?

PubMed

Kamalaldin, N A; Sulaiman, S A; Yusop, M R; Yahaya, B

2017-01-01

Many studies have been done to evaluate the effect of various natural products in controlling asthma symptoms. Virgin coconut oil (VCO) is known to contain active compounds that have beneficial effects on human health and diseases. The objective of this study was to evaluate the effect of VCO inhalation on airway remodelling in a rabbit model of allergic asthma. The effects of VCO inhalation on infiltration of airway inflammatory cells, airway structures, goblet cell hyperplasia, and cell proliferation following ovalbumin induction were evaluated. Allergic asthma was induced by a combination of ovalbumin and alum injection and/or followed by ovalbumin inhalation. The effect of VCO inhalation was then evaluated via the rescue or the preventive route. Percentage of inflammatory cells infiltration, thickness of epithelium and mucosa regions, and the numbers of goblet and proliferative cells were reduced in the rescue group but not in preventive group. Analysis using a gas chromatography-mass spectrometry found that lauric acid and capric acid were among the most abundant fatty acids present in the sample. Significant improvement was observed in rescue route in alleviating the asthma symptoms, which indicates the VCO was able to relieve asthma-related symptoms more than preventing the onset of asthma.

Does Inhalation of Virgin Coconut Oil Accelerate Reversal of Airway Remodelling in an Allergic Model of Asthma?

PubMed Central

Sulaiman, S. A.

2017-01-01

Many studies have been done to evaluate the effect of various natural products in controlling asthma symptoms. Virgin coconut oil (VCO) is known to contain active compounds that have beneficial effects on human health and diseases. The objective of this study was to evaluate the effect of VCO inhalation on airway remodelling in a rabbit model of allergic asthma. The effects of VCO inhalation on infiltration of airway inflammatory cells, airway structures, goblet cell hyperplasia, and cell proliferation following ovalbumin induction were evaluated. Allergic asthma was induced by a combination of ovalbumin and alum injection and/or followed by ovalbumin inhalation. The effect of VCO inhalation was then evaluated via the rescue or the preventive route. Percentage of inflammatory cells infiltration, thickness of epithelium and mucosa regions, and the numbers of goblet and proliferative cells were reduced in the rescue group but not in preventive group. Analysis using a gas chromatography-mass spectrometry found that lauric acid and capric acid were among the most abundant fatty acids present in the sample. Significant improvement was observed in rescue route in alleviating the asthma symptoms, which indicates the VCO was able to relieve asthma-related symptoms more than preventing the onset of asthma. PMID:28660089

Acute lung injury and persistent small airway disease in a rabbit model of chlorine inhalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musah, Sadiatu; Schlueter, Connie F.; Humphrey, Da

Chlorine is a pulmonary toxicant to which humans can be exposed through accidents or intentional releases. Acute effects of chlorine inhalation in humans and animal models have been well characterized, but less is known about persistent effects of acute, high-level chlorine exposures. In particular, animal models that reproduce the long-term effects suggested to occur in humans are lacking. Here, we report the development of a rabbit model in which both acute and persistent effects of chlorine inhalation can be assessed. Male New Zealand White rabbits were exposed to chlorine while the lungs were mechanically ventilated. After chlorine exposure, the rabbitsmore » were extubated and were allowed to survive for up to 24 h after exposure to 800 ppm chlorine for 4 min to study acute effects or up to 7 days after exposure to 400 ppm for 8 min to study longer term effects. Acute effects observed 6 or 24 h after inhalation of 800 ppm chlorine for 4 min included hypoxemia, pulmonary edema, airway epithelial injury, inflammation, altered baseline lung mechanics, and airway hyperreactivity to inhaled methacholine. Seven days after recovery from inhalation of 400 ppm chlorine for 8 min, rabbits exhibited mild hypoxemia, increased area of pressure–volume loops, and airway hyperreactivity. Lung histology 7 days after chlorine exposure revealed abnormalities in the small airways, including inflammation and sporadic bronchiolitis obliterans lesions. Immunostaining showed a paucity of club and ciliated cells in the epithelium at these sites. These results suggest that small airway disease may be an important component of persistent respiratory abnormalities that occur following acute chlorine exposure. This non-rodent chlorine exposure model should prove useful for studying persistent effects of acute chlorine exposure and for assessing efficacy of countermeasures for chlorine-induced lung injury. - Highlights: • A novel rabbit model of chlorine-induced lung disease was

Engineering Functional Epithelium for Regenerative Medicine and In Vitro Organ Models: A Review

PubMed Central

Vrana, Nihal E.; Lavalle, Philippe; Dokmeci, Mehmet R.; Dehghani, Fariba; Ghaemmaghami, Amir M.

2013-01-01

Recent advances in the fields of microfabrication, biomaterials, and tissue engineering have provided new opportunities for developing biomimetic and functional tissues with potential applications in disease modeling, drug discovery, and replacing damaged tissues. An intact epithelium plays an indispensable role in the functionality of several organs such as the trachea, esophagus, and cornea. Furthermore, the integrity of the epithelial barrier and its degree of differentiation would define the level of success in tissue engineering of other organs such as the bladder and the skin. In this review, we focus on the challenges and requirements associated with engineering of epithelial layers in different tissues. Functional epithelial layers can be achieved by methods such as cell sheets, cell homing, and in situ epithelialization. However, for organs composed of several tissues, other important factors such as (1) in vivo epithelial cell migration, (2) multicell-type differentiation within the epithelium, and (3) epithelial cell interactions with the underlying mesenchymal cells should also be considered. Recent successful clinical trials in tissue engineering of the trachea have highlighted the importance of a functional epithelium for long-term success and survival of tissue replacements. Hence, using the trachea as a model tissue in clinical use, we describe the optimal structure of an artificial epithelium as well as challenges of obtaining a fully functional epithelium in macroscale. One of the possible remedies to address such challenges is the use of bottom-up fabrication methods to obtain a functional epithelium. Modular approaches for the generation of functional epithelial layers are reviewed and other emerging applications of microscale epithelial tissue models for studying epithelial/mesenchymal interactions in healthy and diseased (e.g., cancer) tissues are described. These models can elucidate the epithelial/mesenchymal tissue interactions at the

Engineering functional epithelium for regenerative medicine and in vitro organ models: a review.

PubMed

Vrana, Nihal E; Lavalle, Philippe; Dokmeci, Mehmet R; Dehghani, Fariba; Ghaemmaghami, Amir M; Khademhosseini, Ali

2013-12-01

Recent advances in the fields of microfabrication, biomaterials, and tissue engineering have provided new opportunities for developing biomimetic and functional tissues with potential applications in disease modeling, drug discovery, and replacing damaged tissues. An intact epithelium plays an indispensable role in the functionality of several organs such as the trachea, esophagus, and cornea. Furthermore, the integrity of the epithelial barrier and its degree of differentiation would define the level of success in tissue engineering of other organs such as the bladder and the skin. In this review, we focus on the challenges and requirements associated with engineering of epithelial layers in different tissues. Functional epithelial layers can be achieved by methods such as cell sheets, cell homing, and in situ epithelialization. However, for organs composed of several tissues, other important factors such as (1) in vivo epithelial cell migration, (2) multicell-type differentiation within the epithelium, and (3) epithelial cell interactions with the underlying mesenchymal cells should also be considered. Recent successful clinical trials in tissue engineering of the trachea have highlighted the importance of a functional epithelium for long-term success and survival of tissue replacements. Hence, using the trachea as a model tissue in clinical use, we describe the optimal structure of an artificial epithelium as well as challenges of obtaining a fully functional epithelium in macroscale. One of the possible remedies to address such challenges is the use of bottom-up fabrication methods to obtain a functional epithelium. Modular approaches for the generation of functional epithelial layers are reviewed and other emerging applications of microscale epithelial tissue models for studying epithelial/mesenchymal interactions in healthy and diseased (e.g., cancer) tissues are described. These models can elucidate the epithelial/mesenchymal tissue interactions at the

Parasympathetic control of airway submucosal glands: central reflexes and the airway intrinsic nervous system.

PubMed

Wine, Jeffrey J

2007-04-30

Airway submucosal glands produce the mucus that lines the upper airways to protect them against insults. This review summarizes evidence for two forms of gland secretion, and hypothesizes that each is mediated by different but partially overlapping neural pathways. Airway innate defense comprises low level gland secretion, mucociliary clearance and surveillance by airway-resident phagocytes to keep the airways sterile in spite of nearly continuous inhalation of low levels of pathogens. Gland secretion serving innate defense is hypothesized to be under the control of intrinsic (peripheral) airway neurons and local reflexes, and these may depend disproportionately on non-cholinergic mechanisms, with most secretion being produced by VIP and tachykinins. In the genetic disease cystic fibrosis, airway glands no longer secrete in response to VIP alone and fail to show the synergy between VIP, tachykinins and ACh that is observed in normal glands. The consequent crippling of the submucosal gland contribution to innate defense may be one reason that cystic fibrosis airways are infected by mucus-resident bacteria and fungi that are routinely cleared from normal airways. By contrast, the acute (emergency) airway defense reflex is centrally mediated by vagal pathways, is primarily cholinergic, and stimulates copious volumes of gland mucus in response to acute, intense challenges to the airways, such as those produced by very vigorous exercise or aspiration of foreign material. In cystic fibrosis, the acute airway defense reflex can still stimulate the glands to secrete large amounts of mucus, although its properties are altered. Importantly, treatments that recruit components of the acute reflex, such as inhalation of hypertonic saline, are beneficial in treating cystic fibrosis airway disease. The situation for recipients of lung transplants is the reverse; transplanted airways retain the airway intrinsic nervous system but lose centrally mediated reflexes. The consequences

Fatty Acid Binding Protein 4 Regulates VEGF-Induced Airway Angiogenesis and Inflammation in a Transgenic Mouse Model

PubMed Central

Ghelfi, Elisa; Yu, Chen-Wei; Elmasri, Harun; Terwelp, Matthew; Lee, Chun G.; Bhandari, Vineet; Comhair, Suzy A.; Erzurum, Serpil C.; Hotamisligil, Gökhan S.; Elias, Jack A.; Cataltepe, Sule

2014-01-01

Neovascularization of the airways occurs in several inflammatory lung diseases, including asthma. Vascular endothelial growth factor (VEGF) plays an important role in vascular remodeling in the asthmatic airways. Fatty acid binding protein 4 (FABP4 or aP2) is an intracellular lipid chaperone that is induced by VEGF in endothelial cells. FABP4 exhibits a proangiogenic function in vitro, but whether it plays a role in modulation of angiogenesis in vivo is not known. We hypothesized that FABP4 promotes VEGF-induced airway angiogenesis and investigated this hypothesis with the use of a transgenic mouse model with inducible overexpression of VEGF165 under a CC10 promoter [VEGF-TG (transgenic) mice]. We found a significant increase in FABP4 mRNA levels and density of FABP4-expressing vascular endothelial cells in mouse airways with VEGF overexpression. FABP4−/− mouse airways showed a significant decrease in neovessel formation and endothelial cell proliferation in response to VEGF overexpression. These alterations in airway vasculature were accompanied by attenuated expression of proinflammatory mediators. Furthermore, VEGF-TG/FABP4−/− mice showed markedly decreased expression of endothelial nitric oxide synthase, a well-known mediator of VEGF-induced responses, compared with VEGF-TG mice. Finally, the density of FABP4-immunoreactive vessels in endobronchial biopsy specimens was significantly higher in patients with asthma than in control subjects. Taken together, these data unravel FABP4 as a potential target of pathologic airway remodeling in asthma. PMID:23391391

The skin of fish as a transport epithelium: a review.

PubMed

Glover, Chris N; Bucking, Carol; Wood, Chris M

2013-10-01

The primary function of fish skin is to act as a barrier. It provides protection against physical damage and assists with the maintenance of homoeostasis by minimising exchange between the animal and the environment. However in some fish, the skin may play a more active physiological role. This is particularly true in species that inhabit specialised environmental niches (e.g. amphibious and air-breathing fish such as the lungfish), those with physiological characteristics that may subvert the need for the integument as a barrier (e.g. the osmoconforming hagfish), and/or fish with anatomical modifications of the epidermis (e.g. reduced epithelial thickness). Using examples from different fish groups (e.g. hagfishes, elasmobranchs and teleosts), the importance of fish skin as a transport epithelium for gases, ions, nitrogenous waste products, and nutrients was reviewed. The role of the skin in larval fish was also examined, with early life stages often utilising the skin as a surrogate gill, prior to the development of a functional branchial epithelium.

Olfactory epithelium changes in germfree mice

PubMed Central

François, Adrien; Grebert, Denise; Rhimi, Moez; Mariadassou, Mahendra; Naudon, Laurent; Rabot, Sylvie; Meunier, Nicolas

2016-01-01

Intestinal epithelium development is dramatically impaired in germfree rodents, but the consequences of the absence of microbiota have been overlooked in other epithelia. In the present study, we present the first description of the bacterial communities associated with the olfactory epithelium and explored differences in olfactory epithelium characteristics between germfree and conventional, specific pathogen-free, mice. While the anatomy of the olfactory epithelium was not significantly different, we observed a thinner olfactory cilia layer along with a decreased cellular turn-over in germfree mice. Using electro-olfactogram, we recorded the responses of olfactory sensitive neuronal populations to various odorant stimulations. We observed a global increase in the amplitude of responses to odorants in germfree mice as well as altered responses kinetics. These changes were associated with a decreased transcription of most olfactory transduction actors and of olfactory xenobiotic metabolising enzymes. Overall, we present here the first evidence that the microbiota modulates the physiology of olfactory epithelium. As olfaction is a major sensory modality for most animal species, the microbiota may have an important impact on animal physiology and behaviour through olfaction alteration. PMID:27089944

The New Perilaryngeal Airway (CobraPLA™)1 Is as Efficient as the Laryngeal Mask Airway (LMA™)2, But Provides Better Airway Sealing Pressures

PubMed Central

Akça, Ozan; Wadhwa, Anupama; Sengupta, Papiya; Durrani, Jaleel; Hanni, Keith; Wenke, Mary; Yücel, Yüksel; Lenhardt, Rainer; Doufas, Anthony G.; Sessler, Daniel I.

2006-01-01

The Laryngeal Mask Airway (LMA) is a frequently-used efficient airway device, yet it sometimes seals poorly, thus reducing the efficacy of positive-pressure ventilation. The Perilaryngeal Airway (CobraPLA) is a novel airway device with a larger pharyngeal cuff (when inflated). We tested the hypothesis that the CobraPLA was superior to LMA with regard to insertion time and airway sealing pressure and comparable to LMA in airway adequacy and recovery characteristics. After midazolam and fentanyl, 81 ASA I-II outpatients having elective surgery were randomized to receive an LMA or CobraPLA. Anesthesia was induced with propofol (2.5 mg/kg, IV), and the airway inserted. We measured 1) insertion time; 2) adequacy of the airway (no leak at 15-cm-H2O peak pressure or tidal volume of 5 ml/kg); 3) airway sealing pressure; 4) number of repositioning attempts; and 5) sealing quality (no leak at tidal volume of 8 ml/kg). At the end of surgery, gastric insufflation, postoperative sore throat, dysphonia, and dysphagia were evaluated. Data were compared with unpaired t-tests, chi-square tests, or Fisher’s Exact tests; P<0.05 was significant. Patient characteristics, insertion times, airway adequacy, number of repositioning attempts, and recovery were similar in each group. Airway sealing pressure was significantly greater with CobraPLA (23±6 cm H2O) than LMA (18±5 cm H2O, P<0.001). The CobraPLA has insertion characteristics similar to LMA, but better airway sealing capabilities. PMID:15281543

Targeting Phosphoinositide 3-Kinase γ in Airway Smooth Muscle Cells to Suppress Interleukin-13-Induced Mouse Airway Hyperresponsiveness

PubMed Central

Jiang, Haihong; Xie, Yan; Abel, Peter W.; Toews, Myron L.; Townley, Robert G.; Casale, Thomas B.

2012-01-01

We recently reported that phosphoinositide 3-kinase γ (PI3Kγ) directly regulates airway smooth muscle (ASM) contraction by modulating Ca2+ oscillations. Because ASM contraction plays a critical role in airway hyperresponsiveness (AHR) of asthma, the aim of the present study was to determine whether targeting PI3Kγ in ASM cells could suppress AHR in vitro and in vivo. Intranasal administration into mice of interleukin-13 (IL-13; 10 μg per mouse), a key pathophysiologic cytokine in asthma, induced AHR after 48 h, as assessed by invasive tracheostomy. Intranasal administration of a broad-spectrum PI3K inhibitor or a PI3Kγ-specific inhibitor 1 h before AHR assessment attenuated IL-13 effects. Airway responsiveness to bronchoconstrictor agonists was also examined in precision-cut mouse lung slices pretreated without or with IL-13 for 24 h. Acetylcholine and serotonin dose-response curves indicated that IL-13-treated lung slices had a 40 to 50% larger maximal airway constriction compared with controls. Furthermore, acetylcholine induced a larger initial Ca2+ transient and increased Ca2+ oscillations in IL-13-treated primary mouse ASM cells compared with control cells, correlating with increased cell contraction. As expected, PI3Kγ inhibitor treatment attenuated IL-13-augmented airway contractility of lung slices and ASM cell contraction. In both control and IL-13-treated ASM cells, small interfering RNA-mediated knockdown of PI3Kγ by 70% only reduced the initial Ca2+ transient by 20 to 30% but markedly attenuated Ca2+ oscillations and contractility of ASM cells by 50 to 60%. This report is the first to demonstrate that PI3Kγ in ASM cells is important for IL-13-induced AHR and that acute treatment with a PI3Kγ inhibitor can ameliorate AHR in a murine model of asthma. PMID:22543031

Visualisation of Multiple Tight Junctional Complexes in Human Airway Epithelial Cells.

PubMed

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

2018-01-01

Apically located tight junctions in airway epithelium perform a fundamental role in controlling macromolecule migration through paracellular spaces. Alterations in their expression may lead to disruptions in barrier integrity, which subsequently facilitates entry of potential bacterial and other pathogens into the host. Furthermore, there is emerging evidence that the barrier integrity of the airway in certain airway inflammatory diseases may be altered. However, there is little consensus on the way this is assessed and measured and the type of cells used to achieve this. Here, we assessed four fixation methods including; (i) 4% ( v /v) paraformaldehyde; (ii) 100% methanol; (iii) acetone or; (iv) 1:1 methanol: acetone. Pre-extraction with Triton X-100 was also performed and assessed on cells prior to fixation with either methanol or paraformaldehyde. Cells were also permeabilized with 0.1% (v/v) Saponin in 1× TBS following fixation and subsequently stained for tight junction proteins. Confocal microscopy was then used to visualise, compare and evaluate staining intensity of the tight junctional complexes in order to determine a standardised workflow of reproducible staining. Positive staining was observed following methanol fixation for claudin-1 and ZO-1 tight junction proteins but no staining was detected for occludin in 16HBE14o- cells. Combinatorial fixation with methanol and acetone also produced consistent positive staining for both occludin and ZO-1 tight junction proteins in these cells. When assessed using primary cells cultured at air-liquid interface, similar positive staining for claudin-1 and ZO-1 was observed following methanol fixation, while similar positive staining for occludin and ZO-1 was observed following the same combinatorial fixation with methanol and acetone. The present study demonstrates the importance of a personalised approach to optimise staining for the visualisation of different tight junction proteins. Of significance, the

Airway surface mycosis in chronic TH2-associated airway disease.

PubMed

Porter, Paul C; 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

2014-08-01

Environmental fungi have been linked to TH2 cell-related airway inflammation and the TH2-associated chronic airway diseases asthma, chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), and allergic fungal rhinosinusitis (AFRS), but whether these organisms participate directly or indirectly in disease pathology remains unknown. To determine the frequency of fungus isolation and fungus-specific immunity in patients with TH2-associated and non-TH2-associated airway disease. Sinus lavage fluid and blood were collected from sinus surgery patients (n = 118) including patients with CRSwNP, patients with CRS without nasal polyps, patients with AFRS, and non-CRS/nonasthmatic control patients. Asthma status was determined from medical history. Sinus lavage fluids were cultured and directly examined for evidence of viable fungi. PBMCs were restimulated with fungal antigens in an enzyme-linked immunocell spot assay to determine total memory fungus-specific IL-4-secreting cells. These data were compared with fungus-specific IgE levels measured from plasma by ELISA. Filamentous fungi were significantly more commonly cultured in patients with TH2-associated airway disease (asthma, CRSwNP, or AFRS: n = 68) than in control patients with non-TH2-associated disease (n = 31): 74% vs 16%, respectively (P < .001). Both fungus-specific IL-4 enzyme-linked immunocell spot (n = 48) and specific IgE (n = 70) data correlated with TH2-associated diseases (sensitivity 73% and specificity 100% vs 50% and 77%, respectively). 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. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility

PubMed Central

Cook, Daniel P.; Rector, Michael V.; Bouzek, Drake C.; Michalski, Andrew S.; Gansemer, Nicholas D.; Reznikov, Leah R.; Li, Xiaopeng; Stroik, Mallory R.; Ostedgaard, Lynda S.; Abou Alaiwa, Mahmoud H.; Thompson, Michael A.; Prakash, Y. S.; Krishnan, Ramaswamy; Meyerholz, David K.; Seow, Chun Y.

2016-01-01

Rationale: An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. Objectives: Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. Methods: Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. Measurements and Main Results: We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. Conclusions: Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing. PMID:26488271

Aerosolized polymerized type I collagen reduces airway inflammation and remodelling in a guinea pig model of allergic asthma.

PubMed

Moreno-Alvarez, Paola; Sánchez-Guerrero, Edgar; Martínez-Cordero, Erasmo; Hernández-Pando, Rogelio; Campos, María G; Cetina, Lucely; Bazán-Perkins, Blanca

2010-04-01

Collagen-polyvinylpyrrolidone (Collagen-PVP) has been demonstrated to elicit immunomodulatory properties in different chronic inflammatory diseases. Nevertheless, its effects on asthma are still unknown. We have evaluated whether collagen-PVP could modulate airway inflammation and remodelling in a guinea pig model of allergic asthma. Sensitized guinea pigs were challenged with the allergen (ovalbumin) six times (at 10-day intervals). From the third challenge on, animals were treated every 5 days with saline aerosols containing 0.16, 0.33, or 0.66 mg/ml of collagen-PVP (n = 5, respectively). Some guinea pigs, sensitized and challenged with saline as well as treated with 0 or 0.66 mg/ml collagen-PVP, were included in the study as control (n = 7) and sham groups (n = 5), respectively. From the first challenge on, ovalbumin induced a transient airway obstruction, measured by barometric plethysmography, which was not modified by collagen-PVP treatments. After the last allergen challenge, guinea pigs were anesthetized to obtain bronchoalveolar lavage (BAL) and the left lung caudal lobe. As expected, BAL cell count from allergen-challenged guinea pigs showed abundant neutrophils and eosinophils, as well as numerous tumor necrosis factor (TNF)-alpha-expressing granulocytes and macrophages in airway wall (determined by immunohistochemical assay). Neutrophilia and TNF-alpha-expressing leukocytes, from collagen-PVP treated animals, diminished from 0.16 mg/ml, and eosinophilia from 0.66 mg/ml of collagen-PVP doses. Histological changes induced by allergen challenges include thickening of connective tissue below airway epithelium and vascular wall widening of airway adjacent vessels; these changes were reduced by collagen-PVP treatment. Collagen-PVP seems to have anti-inflammatory and antifibrotic properties in this guinea pig asthma model.

Cytokeratin expression in mouse lacrimal gland germ epithelium.

PubMed

Hirayama, Masatoshi; Liu, Ying; Kawakita, Tetsuya; Shimmura, Shigeto; Tsubota, Kazuo

2016-05-01

The lacrimal gland secretes tear fluids that protect the ocular surface epithelium, and its dysfunction leads to dry eye disease (DED). The functional restoration of the lacrimal gland by engraftment of a bioengineered lacrimal gland using lacrimal gland germ epithelial cells has been proposed to cure DED in mice. Here, we investigate the expression profile of cytokeratins in the lacrimal gland germ epithelium to clarify their unique characteristics. We performed quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC) analysis to clarify the expression profile of cytokeratin in the lacrimal gland germ epithelium. The mRNA expression of keratin (KRT) 5, KRT8, KRT14, KRT15, and KRT18 in the lacrimal gland germ epithelium was increased compared with that in mouse embryonic stem cells and the lacrimal gland germ mesenchyme, as analyzed by Q-PCR. The expression level of KRT15 increased in the transition from stem cells to lacrimal gland germ epithelium, then decreased as the lacrimal gland matured. IHC revealed that the expression set of these cytokeratins in the lacrimal gland germ epithelium was different from that in the adult lacrimal gland. The expression of KRT15 was observed in the lacrimal gland germ epithelium, and it segmentalized into some of the basal cells in the intercanulated duct in mature gland. We determined the expression profile of cytokeratins in the lacrimal gland epithelium, and identified KRT15 as a candidate unique cellular marker for the lacrimal gland germ epithelium. Copyright © 2015 Elsevier Ltd. All rights reserved.

DNA damage in lens epithelium of cataract patients in vivo and ex vivo.

PubMed

Øsnes-Ringen, Oyvind; Azqueta, Amaia O; Moe, Morten C; Zetterström, Charlotta; Røger, Magnus; Nicolaissen, Bjørn; Collins, Andrew R

2013-11-01

DNA damage has been described in the human cataractous lens epithelium, and oxidative stress generated by UV radiation and endogenous metabolic processes has been suggested to play a significant role in the pathogenesis of cataract. In this study, the aim was to explore the quality and relative quantity of DNA damage in lens epithelium of cataract patients in vivo and after incubation in a cell culture system. Capsulotomy specimens were analysed, before and after 1 week of ex vivo cultivation, using the comet assay to measure DNA strand breaks, oxidized purine and pyrimidine bases and UV-induced cyclobutane pyrimidine dimers. DNA strand breaks were barely detectable, oxidized pyrimidines and pyrimidine dimers were present at low levels, whereas there was a relatively high level of oxidized purines, which further increased after cultivation. The observed levels of oxidized purines in cataractous lens epithelium may support a theory consistent with light damage and oxidative stress as mediators of molecular damage to the human lens epithelium. Damage commonly associated with UV-B irradiation was relatively low. The levels of oxidized purines increased further in a commonly used culture system. This is of interest considering the importance and versatility of ex vivo systems in studies exploring the pathogenesis of cataract. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

Adoptive transfer of induced-Treg cells effectively attenuates murine airway allergic inflammation.

PubMed

Xu, Wei; Lan, Qin; Chen, Maogen; Chen, Hui; Zhu, Ning; Zhou, Xiaohui; Wang, Julie; Fan, Huimin; Yan, Chun-Song; Kuang, Jiu-Long; Warburton, David; Togbe, Dieudonnée; Ryffel, Bernhard; Zheng, Song-Guo; Shi, Wei

2012-01-01

Both nature and induced regulatory T (Treg) lymphocytes are potent regulators of autoimmune and allergic disorders. Defects in endogenous Treg cells have been reported in patients with allergic asthma, suggesting that disrupted Treg cell-mediated immunological regulation may play an important role in airway allergic inflammation. In order to determine whether adoptive transfer of induced Treg cells generated in vitro can be used as an effective therapeutic approach to suppress airway allergic inflammation, exogenously induced Treg cells were infused into ovalbumin-sensitized mice prior to or during intranasal ovalbumin challenge. The results showed that adoptive transfer of induced Treg cells prior to allergen challenge markedly reduced airway hyperresponsiveness, eosinophil recruitment, mucus hyper-production, airway remodeling, and IgE levels. This effect was associated with increase of Treg cells (CD4(+)FoxP3(+)) and decrease of dendritic cells in the draining lymph nodes, and with reduction of Th1, Th2, and Th17 cell response as compared to the controls. Moreover, adoptive transfer of induced Treg cells during allergen challenge also effectively attenuate airway inflammation and improve airway function, which are comparable to those by natural Treg cell infusion. Therefore, adoptive transfer of in vitro induced Treg cells may be a promising therapeutic approach to prevent and treat severe asthma.

Adoptive Transfer of Induced-Treg Cells Effectively Attenuates Murine Airway Allergic Inflammation

PubMed Central

Chen, Maogen; Chen, Hui; Zhu, Ning; Zhou, Xiaohui; Wang, Julie; Fan, Huimin; Yan, Chun-Song; Kuang, Jiu-Long; Warburton, David; Togbe, Dieudonnée; Ryffel, Bernhard; Zheng, Song-Guo; Shi, Wei

2012-01-01

Both nature and induced regulatory T (Treg) lymphocytes are potent regulators of autoimmune and allergic disorders. Defects in endogenous Treg cells have been reported in patients with allergic asthma, suggesting that disrupted Treg cell-mediated immunological regulation may play an important role in airway allergic inflammation. In order to determine whether adoptive transfer of induced Treg cells generated in vitro can be used as an effective therapeutic approach to suppress airway allergic inflammation, exogenously induced Treg cells were infused into ovalbumin-sensitized mice prior to or during intranasal ovalbumin challenge. The results showed that adoptive transfer of induced Treg cells prior to allergen challenge markedly reduced airway hyperresponsiveness, eosinophil recruitment, mucus hyper-production, airway remodeling, and IgE levels. This effect was associated with increase of Treg cells (CD4+FoxP3+) and decrease of dendritic cells in the draining lymph nodes, and with reduction of Th1, Th2, and Th17 cell response as compared to the controls. Moreover, adoptive transfer of induced Treg cells during allergen challenge also effectively attenuate airway inflammation and improve airway function, which are comparable to those by natural Treg cell infusion. Therefore, adoptive transfer of in vitro induced Treg cells may be a promising therapeutic approach to prevent and treat severe asthma. PMID:22792275

Expression of nitric oxide synthase-2 in the lungs decreases airway resistance and responsiveness.

PubMed

Hjoberg, Josephine; Shore, Stephanie; Kobzik, Lester; Okinaga, Shoji; Hallock, Arlene; Vallone, Joseph; Subramaniam, Venkat; De Sanctis, George T; Elias, Jack A; Drazen, Jeffrey M; Silverman, Eric S

2004-07-01

Individuals with asthma have increased levels of nitric oxide in their exhaled air. To explore its role, we have developed a regulatable transgenic mouse capable of overexpressing inducible nitric oxide synthase in a lung-specific fashion. The CC10-rtTA-NOS-2 mouse contains two transgenes, a reverse tetracycline transactivator under the control of the Clara cell protein promoter and the mouse nitric oxide synthase-2 (NOS-2) coding region under control of a tetracycline operator. Addition of doxycycline to the drinking water of CC10-rtTA-NOS-2 mice causes an increase in nitric oxide synthase-2 that is largely confined to the airway epithelium. The fraction of expired nitric oxide increases over the first 24 h from approximately 10 parts per billion to a plateau of approximately 20 parts per billion. There were no obvious differences between CC10-rtTA-NOS-2 mice, with or without doxycycline, and wild-type mice in lung histology, bronchoalveolar protein, total cell count, or count differentials. However, airway resistance was lower in CC10-rtTA-NOS-2 mice with doxycycline than in CC10-rtTA-NOS-2 mice without doxycycline or wild-type mice with doxycycline. Moreover, doxycycline-treated CC10-rtTA-NOS-2 mice were hyporesponsive to methacholine compared with other groups. These data suggest that increased nitric oxide in the airways has no proinflammatory effects per se and may have beneficial effects on pulmonary function.

Systemic and airway oxidative stress in competitive swimmers.

PubMed

Škrgat, Sabina; Marčun, Robert; Kern, Izidor; Šilar, Mira; Šelb, Julij; Fležar, Matjaž; Korošec, Peter

2018-04-01

The environment in swimming pools, which contain chlorine, might interact with the airway epithelium, resulting in oxidative stress and/or inflammation during high intensity training periods. We evaluated pulmonary functional (metacholine challenge test, FEV1 and VC), cellular (eosinophils and neutrophils), inflammatory (FeNo, IL-5, IL-6, IL-8 and TNF-α), oxidative (8-isoprostanes) and angiogenesis factors (VEGF) in induced sputum and peripheral blood of 41 healthy non-asthmatic elite swimmers (median 16 years) during the period of high intensity training before a national championship. The second paired sampling was performed seven months later after training had been stopped for one month. There was a ten-fold increase (median 82-924 pg/ml; P < 0.001) in 8-isoprostanes in induced sputum and five-fold increase (median 82-924 pg/ml; P < 0.001) in sera during training in comparison to the period of rest. However, there was no difference in FEV1 (113 vs 116%), VC (119 vs 118%), FeNo (median 34 vs 38 ppb), eosinophils (2.7 vs 2.9% in sputum; 180 vs 165 cells/μl in blood), neutrophils, different cytokines or VEGF in induced sputum or sera. The only exception was TNF-α, which was moderately increased in sera (median 23 vs 40 pg/ml; P = 0.02) during the peak training period. Almost half (18 of 41) of swimmers showed bronchial hyperresponsiveness during the peak training period (PC20 cutoff was 4 mg/ml). There was no correlation between hyperresponsiveness and the markers of oxidative stress or inflammation. High intensity training in healthy, non-asthmatic competitive swimmers results in marked oxidative stress at the airway and systemic levels, but does not lead to airway inflammation. However, we could not confirm that oxidative stress is associated with bronchial hyperresponsiveness (AHR), which is often observed during the peak exercise training period. Copyright © 2018. Published by Elsevier Ltd.

The eicosanoid, 15-(S)-HETE, stimulates secretion of mucin-like glycoprotein by the corneal epithelium.

PubMed

Jackson , R S; Van Dyken, S J; McCartney, M D; Ubels, J L

2001-07-01

The eicosanoid, 15-(S)-hydroxyeicosa-5Z, 8Z-11Z, 13E-tetraenoic acid (15-(S)-HETE), is known to stimulate production of mucin glycoprotein by airway epithelium. This study investigated the effect of 15-(S)-HETE on the mucin glycoprotein secretion by the corneal epithelium. To determine the effect of dose, corneas of anesthetized New Zealand White rabbits were treated with 50, 500, or 5,000 nM 15-(S)-HETE in artificial tears for 120 minutes. To determine the time to onset of the response, corneas were treated with 500 or 1,000 nM 15-(S)-HETE in balanced salt solution for periods ranging from 5 to 120 minutes. Corneas were fixed for electron microscopy in fixative containing 0.5% cetylpyridinium chloride (CPC) to stabilize the layer of mucin-like glycoprotein on the corneal surface. The mucin layer thickness was measured by image analysis of electron micrographs. The layer of CPC-fixed mucin-like glycoprotein on the surface of control corneas was 0.46 +/- 0.04 microm thick. After treatment with 15-(S)-HETE, the thickness of the mucin layer increased to 0.64 +/- 0.1 microm at 50 or 5,000 nM HETE and as much as 1.02 +/- 0.2 microm in response to 500 nM HETE. Mucin thickness reached a statistical maximum of 0.59 +/- 0.1 microm after only 5 minutes of exposure to 500 or 1,000 nM HETE. Exposure of the cornea to 15-(S)-HETE causes a rapid-onset increase in the thickness of a layer of mucin-like glycoprotein on the surface of the corneal epithelium. This supports previous reports that corneal epithelial cells produce mucin and suggests that treatment with topical 15-(S)-HETE may be effective in treating ocular surface mucin deficiency in dry eye syndrome.

Difficult airway response team: a novel quality improvement program for managing hospital-wide airway emergencies.

PubMed

Mark, Lynette J; Herzer, Kurt R; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I; Berkow, Lauren C; Haut, Elliott R; Hillel, Alexander T; Miller, Christina R; Feller-Kopman, David J; Schiavi, Adam J; Xie, Yanjun J; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W; Mirski, Marek A

2015-07-01

Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. We developed a quality improvement program-the Difficult Airway Response Team (DART)-to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had 3 core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a Web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index >40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous or current tracheostomy. Twenty

Difficult Airway Response Team: A Novel Quality Improvement Program for Managing Hospital-Wide Airway Emergencies

PubMed Central

Mark, Lynette J.; Herzer, Kurt R.; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I.; Berkow, Lauren C.; Haut, Elliott R.; Hillel, Alexander T.; Miller, Christina R.; Feller-Kopman, David J.; Schiavi, Adam J.; Xie, Yanjun J.; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W.; Mirski, Marek A.

2015-01-01

Background Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. Methods We developed a quality improvement program—the Difficult Airway Response Team (DART)—to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had three core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Results Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index > 40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous

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

Role of Aquaporin Water Channels in Airway Fluid Transport, Humidification, and Surface Liquid Hydration

PubMed Central

Song, Yuanlin; Jayaraman, Sujatha; Yang, Baoxue; Matthay, Michael A.; Verkman, A.S.

2001-01-01

Several aquaporin-type water channels are expressed in mammalian airways and lung: AQP1 in microvascular endothelia, AQP3 in upper airway epithelia, AQP4 in upper and lower airway epithelia, and AQP5 in alveolar epithelia. Novel quantitative methods were developed to compare airway fluid transport–related functions in wild-type mice and knockout mice deficient in these aquaporins. Lower airway humidification, measured from the moisture content of expired air during mechanical ventilation with dry air through a tracheotomy, was 54–56% efficient in wild-type mice, and reduced by only 3–4% in AQP1/AQP5 or AQP3/AQP4 double knockout mice. Upper airway humidification, measured from the moisture gained by dry air passed through the upper airways in mice breathing through a tracheotomy, decreased from 91 to 50% with increasing ventilation from 20 to 220 ml/min, and reduced by 3–5% in AQP3/AQP4 knockout mice. The depth and salt concentration of the airway surface liquid in trachea was measured in vivo using fluorescent probes and confocal and ratio imaging microscopy. Airway surface liquid depth was 45 ± 5 μm and [Na+] was 115 ± 4 mM in wild-type mice, and not significantly different in AQP3/AQP4 knockout mice. Osmotic water permeability in upper airways, measured by an in vivo instillation/sample method, was reduced by ∼40% by AQP3/AQP4 deletion. In doing these measurements, we discovered a novel amiloride-sensitive isosmolar fluid absorption process in upper airways (13% in 5 min) that was not affected by aquaporin deletion. These results establish the fluid transporting properties of mouse airways, and indicate that aquaporins play at most a minor role in airway humidification, ASL hydration, and isosmolar fluid absorption. PMID:11382807

Early Detection of Ovarian Cancer by Tumor Epithelium-Targeted Molecular Ultrasound

DTIC Science & Technology

2014-10-01

successful pregnancy outcome. *PIF Proprietary G-12 IL-33-responsive group 2 innate lymphoid cells are present in mouse uterine tissue and may play roles in... innate lymphoid cells (ILC2s) that are responsive to IL-33 drive helminth immunity, type 2 immune responses, and tissue pathology and homeostasis in...16 (IL-16) secreted by immune cells . Inflammation of the ovary and tubal epithelium due to frequent ovulation leads to the development of oxidative

Laryngeal mask airway for airway control during percutaneous dilatational tracheostomy.

PubMed

Pratt, T; Bromilow, J

2011-11-01

Percutaneous dilatational tracheostomy is a common bedside procedure in critical care for patients requiring prolonged mechanical ventilation. The traditional technique requires withdrawal of the endotracheal tube to a proximal position to facilitate tracheostomy insertion, but this carries the risk of inadvertent extubation and does not prevent cuff rupture. Use of a supraglottic airway such as the laryngeal mask airway may avoid these risks and could provide a safe alternative to the endotracheal tube. We present an appraisal of the literature to date. We found reasonable evidence to show improved ventilation and bronchoscopic visualisation with the laryngeal mask airway, but this has not been translated into improved outcome. There is currently insufficient evidence to draw conclusions about the safety of the laryngeal mask airway during percutaneous dilatational tracheostomy.

Alterations in vasodilator-stimulated phosphoprotein (VASP) phosphorylation: associations with asthmatic phenotype, airway inflammation and beta2-agonist use.

PubMed

Hastie, Annette T; Wu, Min; Foster, Gayle C; Hawkins, Gregory A; Batra, Vikas; Rybinski, Katherine A; Cirelli, Rosemary; Zangrilli, James G; Peters, Stephen P

2006-02-15

Vasodilator-stimulated phosphoprotein (VASP) mediates focal adhesion, actin filament binding and polymerization in a variety of cells, thereby inhibiting cell movement. Phosphorylation of VASP via cAMP and cGMP dependent protein kinases releases this "brake" on cell motility. Thus, phosphorylation of VASP may be necessary for epithelial cell repair of damage from allergen-induced inflammation. Two hypotheses were examined: (1) injury from segmental allergen challenge increases VASP phosphorylation in airway epithelium in asthmatic but not nonasthmatic normal subjects, (2) regular in vivo beta2-agonist use increases VASP phosphorylation in asthmatic epithelium, altering cell adhesion. Bronchial epithelium was obtained from asthmatic and non-asthmatic normal subjects before and after segmental allergen challenge, and after regularly inhaled albuterol, in three separate protocols. VASP phosphorylation was examined in Western blots of epithelial samples. DNA was obtained for beta2-adrenergic receptor haplotype determination. Although VASP phosphorylation increased, it was not significantly greater after allergen challenge in asthmatics or normals. However, VASP phosphorylation in epithelium of nonasthmatic normal subjects was double that observed in asthmatic subjects, both at baseline and after challenge. Regularly inhaled albuterol significantly increased VASP phosphorylation in asthmatic subjects in both unchallenged and antigen challenged lung segment epithelium. There was also a significant increase in epithelial cells in the bronchoalveolar lavage of the unchallenged lung segment after regular inhalation of albuterol but not of placebo. The haplotypes of the beta2-adrenergic receptor did not appear to associate with increased or decreased phosphorylation of VASP. Decreased VASP phosphorylation was observed in epithelial cells of asthmatics compared to nonasthmatic normals, despite response to beta-agonist. The decreased phosphorylation does not appear to be

What evidence implicates airway smooth muscle in the cause of BHR?

PubMed

Dulin, Nickolai O; Fernandes, Darren J; Dowell, Maria; Bellam, Shashi; McConville, John; Lakser, Oren; Mitchell, Richard; Camoretti-Mercado, Blanca; Kogut, Paul; Solway, Julian

2003-02-01

Bronchial hyperresponsiveness (BHR), the occurrence of excessive bronchoconstriction in response to relatively small constrictor stimuli, is a cardinal feature of asthma. Here, we consider the role that airway smooth muscle might play in the generation of BHR. The weight of evidence suggests that smooth muscle isolated from asthmatic tissues exhibits normal sensitivity to constrictor agonists when studied during isometric contraction, but the increased muscle mass within asthmatic airways might generate more total force than the lesser amount of muscle found in normal bronchi. Another salient difference between asthmatic and normal individuals lies in the effect of deep inhalation (DI) on bronchoconstriction. DI often substantially reverses induced bronchoconstriction in normals, while it often has much less effect on spontaneous or induced bronchoconstriction in asthmatics. It has been proposed that abnormal dynamic aspects of airway smooth muscle contraction velocity of contraction or plasticity- elasticity balance might underlie the abnormal DI response in asthma. We suggest a speculative model in which abnormally long actin filaments might account for abnormally increased elasticity of contracted airway smooth muscle.

SLC26A9-mediated chloride secretion prevents mucus obstruction in airway inflammation

PubMed Central

Anagnostopoulou, Pinelopi; Riederer, Brigitte; Duerr, Julia; Michel, Sven; Binia, Aristea; Agrawal, Raman; Liu, Xuemei; Kalitzki, Katrin; Xiao, Fang; Chen, Mingmin; Schatterny, Jolanthe; Hartmann, Dorothee; Thum, Thomas; Kabesch, Michael; Soleimani, Manoocher; Seidler, Ursula; Mall, Marcus A.

2012-01-01

Asthma is a chronic condition with unknown pathogenesis, and recent evidence suggests that enhanced airway epithelial chloride (Cl–) secretion plays a role in the disease. However, the molecular mechanism underlying Cl– secretion and its relevance in asthma pathophysiology remain unknown. To determine the role of the solute carrier family 26, member 9 (SLC26A9) Cl– channel in asthma, we induced Th2-mediated inflammation via IL-13 treatment in wild-type and Slc26a9-deficient mice and compared the effects on airway ion transport, morphology, and mucus content. We found that IL-13 treatment increased Cl– secretion in the airways of wild-type but not Slc26a9-deficient mice. While IL-13–induced mucus overproduction was similar in both strains, treated Slc26a9-deficient mice exhibited airway mucus obstruction, which did not occur in wild-type controls. In a study involving healthy children and asthmatics, a polymorphism in the 3′ UTR of SLC26A9 that reduced protein expression in vitro was associated with asthma. Our data demonstrate that the SLC26A9 Cl– channel is activated in airway inflammation and suggest that SLC26A9-mediated Cl– secretion is essential for preventing airway obstruction in allergic airway disease. These results indicate that SLC26A9 may serve as a therapeutic target for airway diseases associated with mucus plugging. PMID:22945630

Unjamming and cell shape in the asthmatic airway epithelium

NASA Astrophysics Data System (ADS)

Park, Jin-Ah; Kim, Jae Hun; Bi, Dapeng; Mitchel, Jennifer A.; Qazvini, Nader Taheri; Tantisira, Kelan; Park, Chan Young; McGill, Maureen; Kim, Sae-Hoon; Gweon, Bomi; Notbohm, Jacob; Steward, Robert, Jr.; Burger, Stephanie; Randell, Scott H.; Kho, Alvin T.; Tambe, Dhananjay T.; Hardin, Corey; Shore, Stephanie A.; Israel, Elliot; Weitz, David A.; Tschumperlin, Daniel J.; Henske, Elizabeth P.; Weiss, Scott T.; Manning, M. Lisa; Butler, James P.; Drazen, Jeffrey M.; Fredberg, Jeffrey J.

2015-10-01

From coffee beans flowing in a chute to cells remodelling in a living tissue, a wide variety of close-packed collective systems--both inert and living--have the potential to jam. The collective can sometimes flow like a fluid or jam and rigidify like a solid. The unjammed-to-jammed transition remains poorly understood, however, and structural properties characterizing these phases remain unknown. Using primary human bronchial epithelial cells, we show that the jamming transition in asthma is linked to cell shape, thus establishing in that system a structural criterion for cell jamming. Surprisingly, the collapse of critical scaling predicts a counter-intuitive relationship between jamming, cell shape and cell-cell adhesive stresses that is borne out by direct experimental observations. Cell shape thus provides a rigorous structural signature for classification and investigation of bronchial epithelial layer jamming in asthma, and potentially in any process in disease or development in which epithelial dynamics play a prominent role.

Use of a Novel Airway Kit and Simulation in Resident Training on Emergent Pediatric Airways.

PubMed

Melzer, Jonathan M; Hamersley, Erin R S; Gallagher, Thomas Q

2017-06-01

Objective Development of a novel pediatric airway kit and implementation with simulation to improve resident response to emergencies with the goal of improving patient safety. Methods Prospective study with 9 otolaryngology residents (postgraduate years 1-5) from our tertiary care institution. Nine simulated pediatric emergency airway drills were carried out with the existing system and a novel portable airway kit. Response times and time to successful airway control were noted with both the extant airway system and the new handheld kit. Results were analyzed to ensure parametric data and compared with t tests. A Bonferroni adjustment indicated that an alpha of 0.025 was needed for significance. Results Use of the airway kit significantly reduced the mean time of resident arrival by 47% ( P = .013) and mean time of successful intubation by 50% ( P = .007). Survey data indicated 100% improved resident comfort with emergent airway scenarios with use of the kit. Discussion Times to response and meaningful intervention were significantly reduced with implementation of the handheld airway kit. Use of simulation training to implement the new kit improved residents' comfort and airway skills. This study describes an affordable novel mobile airway kit and demonstrates its ability to improve response times. Implications for Practice The low cost of this airway kit makes it a tenable option even for smaller hospitals. Simulation provides a safe and effective way to familiarize oneself with novel equipment, and, when possible, realistic emergent airway simulations should be used to improve provider performance.

Efficacy of Surgical Airway Plasty for Benign Airway Stenosis.

PubMed

Tsukioka, Takuma; Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Inoue, Hidetoshi; Yamamoto, Ryoji

2016-01-01

Long-term patency is required during treatment for benign airway stenosis. This study investigated the effectiveness of surgical airway plasty for benign airway stenosis. Clinical courses of 20 patients, who were treated with surgical plasty for their benign airway stenosis, were retrospectively investigated. Causes of stenosis were tracheobronchial tuberculosis in 12 patients, post-intubation stenosis in five patients, malacia in two patients, and others in one patient. 28 interventional pulmonology procedures and 20 surgical plasty were performed. Five patients with post-intubation stenosis and four patients with tuberculous stenosis were treated with tracheoplasty. Eight patients with tuberculous stenosis were treated with bronchoplasty, and two patients with malacia were treated with stabilization of the membranous portion. Anastomotic stenosis was observed in four patients, and one to four additional treatments were required. Performance status, Hugh-Jones classification, and ventilatory functions were improved after surgical plasty. Outcomes were fair in patients with tuberculous stenosis and malacia. However, efficacy of surgical plasty for post-intubation stenosis was not observed. Surgical airway plasty may be an acceptable treatment for tuberculous stenosis. Patients with malacia recover well after surgical plasty. There may be untreated patients with malacia who have the potential to benefit from surgical plasty.

Efficacy of Surgical Airway Plasty for Benign Airway Stenosis

PubMed Central

Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Inoue, Hidetoshi; Yamamoto, Ryoji

2015-01-01

Background: Long-term patency is required during treatment for benign airway stenosis. This study investigated the effectiveness of surgical airway plasty for benign airway stenosis. Methods: Clinical courses of 20 patients, who were treated with surgical plasty for their benign airway stenosis, were retrospectively investigated. Results: Causes of stenosis were tracheobronchial tuberculosis in 12 patients, post-intubation stenosis in five patients, malacia in two patients, and others in one patient. 28 interventional pulmonology procedures and 20 surgical plasty were performed. Five patients with post-intubation stenosis and four patients with tuberculous stenosis were treated with tracheoplasty. Eight patients with tuberculous stenosis were treated with bronchoplasty, and two patients with malacia were treated with stabilization of the membranous portion. Anastomotic stenosis was observed in four patients, and one to four additional treatments were required. Performance status, Hugh–Jones classification, and ventilatory functions were improved after surgical plasty. Outcomes were fair in patients with tuberculous stenosis and malacia. However, efficacy of surgical plasty for post-intubation stenosis was not observed. Conclusion: Surgical airway plasty may be an acceptable treatment for tuberculous stenosis. Patients with malacia recover well after surgical plasty. There may be untreated patients with malacia who have the potential to benefit from surgical plasty. PMID:26567879

Three-dimensional Culture of Human Airway Epithelium in Matrigel for Evaluation of Human Rhinovirus C and Bocavirus Infections.

PubMed

Chen, A Xiong; Xie, Guang Cheng; Pan, Dong; DU, Ya Rong; Pang, Li Li; Song, Jing Dong; Duan, Zhao Jun; Hu, Bu Rong

2018-02-01

Newly identified human rhinovirus C (HRV-C) and human bocavirus (HBoV) cannot propagate in vitro in traditional cell culture models; thus obtaining knowledge about these viruses and developing related vaccines are difficult. Therefore, it is necessary to develop a novel platform for the propagation of these types of viruses. A platform for culturing human airway epithelia in a three-dimensional (3D) pattern using Matrigel as scaffold was developed. The features of 3D culture were identified by immunochemical staining and transmission electron microscopy. Nucleic acid levels of HRV-C and HBoV in 3D cells at designated time points were quantitated by real-time polymerase chain reaction (PCR). Levels of cytokines, whose secretion was induced by the viruses, were measured by ELISA. Properties of bronchial-like tissues, such as the expression of biomarkers CK5, ZO-1, and PCK, and the development of cilium-like protuberances indicative of the human respiration tract, were observed in 3D-cultured human airway epithelial (HAE) cultures, but not in monolayer-cultured cells. Nucleic acid levels of HRV-C and HBoV and levels of virus-induced cytokines were also measured using the 3D culture system. Our data provide a preliminary indication that the 3D culture model of primary epithelia using a Matrigel scaffold in vitro can be used to propagate HRV-C and HBoV. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Beneficial effects of ursodeoxycholic acid via inhibition of airway remodelling, apoptosis of airway epithelial cells, and Th2 immune response in murine model of chronic asthma.

PubMed

Işık, S; Karaman, M; Çilaker Micili, S; Çağlayan-Sözmen, Ş; Bağrıyanık, H Alper; Arıkan-Ayyıldız, Z; Uzuner, N; Karaman, Ö

In previous studies, anti-inflammatory, anti-apoptotic and immunomodulatory effects of ursodeoxycholic acid (UDCA) on liver diseases have been shown. In this study, we aimed to investigate the effects of UDCA on airway remodelling, epithelial apoptosis, and T Helper (Th)-2 derived cytokine levels in a murine model of chronic asthma. Twenty-seven BALB/c mice were divided into five groups; PBS-Control, OVA-Placebo, OVA-50mg/kg UDCA, OVA-150mg/kg UDCA, OVA-Dexamethasone. Mice in groups OVA-50mg/kg UDCA, OVA-150mg/kg UDCA, OVA-Dexamethasone received the UDCA (50mg/kg), UDCA (150mg/kg), and dexamethasone, respectively. Epithelium thickness, sub-epithelial smooth muscle thickness, number of mast and goblet cells of samples isolated from the lung were measured. Immunohistochemical scorings of the lung tissue for matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEG-F), transforming growth factor-beta (TGF-β), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases (caspase)-3 were determined. IL-4, IL-5, IL-13, Nitric oxide, ovalbumin-specific immunoglobulin (Ig) E levels were quantified. The dose of 150mg/kg UDCA treatment led to lower epithelial thickness, sub-epithelial smooth muscle thickness, goblet and mast cell numbers compared to placebo. Except for MMP-9 and TUNEL all immunohistochemical scores were similar in both UDCA treated groups and the placebo. All cytokine levels were significantly lower in group IV compared to the placebo. These findings suggested that the dose of 150mg/kg UDCA improved all histopathological changes of airway remodelling and its beneficial effects might be related to modulating Th-2 derived cytokines and the inhibition of apoptosis of airway epithelial cells. Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

Advanced Optical Technologies for Defense Trauma and Critical Care

DTIC Science & Technology

2008-11-01

aid in successful transitioning of optical imaging platforms from the laboratory setting to the clinical environment. Project #2: Airway Injury, Part...characterize the response of an in vitro tissue model of the lung epithelium to chlorine inhalation injury, and evaluate the potential use of this...to more effectively simulate a human airway epithelium . This tissue model of the bronchial epithelium was then exposed to different doses of

The Pivotal Role of Airway Smooth Muscle in Asthma Pathophysiology

PubMed Central

Ozier, Annaïg; Allard, Benoit; Bara, Imane; Girodet, Pierre-Olivier; Trian, Thomas; Marthan, Roger; Berger, Patrick

2011-01-01

Asthma is characterized by the association of airway hyperresponsiveness (AHR), inflammation, and remodelling. The aim of the present article is to review the pivotal role of airway smooth muscle (ASM) in the pathophysiology of asthma. ASM is the main effector of AHR. The mechanisms of AHR in asthma may involve a larger release of contractile mediators and/or a lower release of relaxant mediators, an improved ASM cell excitation/contraction coupling, and/or an alteration in the contraction/load coupling. Beyond its contractile function, ASM is also involved in bronchial inflammation and remodelling. Whereas ASM is a target of the inflammatory process, it can also display proinflammatory and immunomodulatory functions, through its synthetic properties and the expression of a wide range of cell surface molecules. ASM remodelling represents a key feature of asthmatic bronchial remodelling. ASM also plays a role in promoting complementary airway structural alterations, in particular by its synthetic function. PMID:22220184

Allergen and ozone exacerbate serotonin-induced increases in airway smooth muscle contraction in a model of childhood asthma.

PubMed

Moore, Brian D; Hyde, Dallas; Miller, Lisa; Wong, Emily; Frelinger, Jessica; Schelegle, Edward S

2012-01-01

Serotonin (5-HT) modulates cholinergic neurotransmission and exacerbates airway smooth muscle (ASM) contraction in normal animal and nonasthmatic human tissue. Exposure to house dust mite allergen (HDMA) and ozone (O(3)) leads to airway hyperreactivity and 5-HT-positive cells in the airway epithelium of infant rhesus monkeys. Research shows that concomitant exposure in allergic animals has an additive effect on airway hyperreactivity. In this study, the hypothesis is that the exposure of allergic infant rhesus monkeys to HDMA, O(3) and in combination, acting through 5-HT receptors, enhances 5-HT modulation of postganglionic cholinergic ASM contraction. Twenty-four HDMA-sensitized infant monkeys were split into 4 groups at the age of 1 month, and were exposed to filtered air (FA), HDMA, O(3) or in combination (HDMA+O(3)). At the age of 6 months, airway rings were harvested and postganglionic, and parasympathetic-mediated ASM contraction was evaluated using electrical-field stimulation (EFS). 5-HT exacerbated the EFS response within all exposure groups, but had no effect in the FA group. 5-HT(2), 5-HT(3) and 5-HT(4) receptor agonists exacerbated the response. 5-HT concentration-response curves performed after incubation with specific receptor antagonists confirmed the involvement of 5-HT(2), 5-HT(3) and 5-HT(4) receptors. Conversely, a 5-HT(1) receptor agonist attenuated the tension across all groups during EFS, and in ASM contracted via exogenous acetylcholine. HDMA, O(3) and HDMA+O(3) exposure in a model of childhood allergic asthma enhances 5-HT exacerbation of EFS-induced ASM contraction through 5-HT(2), 5-HT(3) and 5-HT(4) receptors. A nonneurogenic inhibitory pathway exists, unaffected by exposure, mediated by 5-HT(1) receptors located on ASM. Copyright © 2012 S. Karger AG, Basel.

Following damage, the majority of bone marrow-derived airway cells express an epithelial marker

PubMed Central

MacPherson, Heather; Keir, Pamela A; Edwards, Carol J; Webb, Sheila; Dorin, Julia R

2006-01-01

Background Adult-derived bone marrow stem cells are capable of reconstituting the haematopoietic system. However there is ongoing debate in the literature as to whether bone marrow derived cells have the ability to populate other tissues and express tissue specific markers. The airway has been an organ of major interest and was one of the first where this was demonstrated. We have previously demonstrated that the mouse airway can be repopulated by side population bone marrow transplanted cells. Here we investigate the frequency and phenotypic nature of these bone marrow derived cells. Methods Female mice were engrafted with male whole bone marrow or side population (SP) cells and subjected to detergent-induced damage after 3 months. Donor cells were identified by Y chromosome fluorescence in situ hybridisation and their phenotype was assessed by immunohistochemistry on the same sections. Slides were visualised by a combination of widefield and deconvolved microscopy and whole cells were analysed on cytospin preparations. Results The frequencies of engraftment of male cells in the airway of mice that show this (9/10), range from 1.0 – 1.6% with whole marrow and 0.6 – 1.5% with SP cells. Undamaged controls have only between 0.1 and 0.2% male cells in the trachea. By widefield microscopy analysis we find 60.2% (53/88) of male donor derived cells express cytokeratins as a marker of epithelial cells. These results were reinforced using deconvolved microscopy and scored by two independent investigators. In addition cytospin analysis of cells dissociated from the damaged trachea of engrafted mice also reveals donor derived Y chromosome positive cells that are immunopositive for cytokeratin. Using cytokeratin and the universal haematopoietic marker CD45 immunohistochemistry, we find the donor derived cells fall into four phenotypic classes. We do not detect cytokeratin positive cells in whole bone marrow using cytokeratin immunostaining and we do not detect any

Airway management in neuroanesthesiology.

PubMed

Aziz, Michael

2012-06-01

Airway management for neuroanesthesiology brings together some key principles that are shared throughout neuroanesthesiology. This article appropriately targets the cervical spine with associated injury and the challenges surrounding airway management. The primary focus of this article is on the unique airway management obstacles encountered with cervical spine injury or cervical spine surgery, and unique considerations regarding functional neurosurgery are addressed. Furthermore, topics related to difficult airway management for those with rheumatoid arthritis or pituitary surgery are reviewed. Copyright © 2012 Elsevier Inc. All rights reserved.

Imaging of mucus clearance in the airways of living spontaneously breathing mice by optical coherence microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pieper, Mario; Schulz-Hildebrandt, Hinnerk; Hüttmann, Gereon; König, Peter

2016-03-01

Mucus transport is essential to remove inhaled particles and pathogens from the lung. Impaired removal of mucus often results in worsening of lung diseases. To understand the mechanisms of mucus transport and to monitor the impact of therapeutic strategies, it is essential to visualize airways and mucus in living animals without disturbing transport processes by intubation or surgically opening the airways. We developed a custom-built optical coherence microscope (OCM) providing a lateral and axial resolution of approximately 1.5 µm with a field of view of 2 mm at up to 150 images/s. Images of the intact trachea and its mucus transport were recorded in anesthetized spontaneously breathing mice. NaCl solution (0.9% and 7%) or Lipopolysaccharide were applied intranasally. OCM resolved detailed structure of the trachea and enabled measuring the airway surface liquid (ASL) thickness through the tracheal wall. Without stimulation, the amount of ASL was only a few µm above the epithelium and remained constant. After intranasal application of 30 µl saline at different concentrations, an early fast cough-like fluid removal with velocities higher than 1 mm/s was observed that removed a high amount of liquid. The ASL thickness increased transiently and quickly returned to levels before stimulation. In contrast to saline, application of Lipopolysaccharide induced substantial mucus release and an additional slow mucus transport by ciliary beating (around 100 µm/s) towards the larynx was observed. In conclusion, OCM is appropriate unique tool to study mechanisms of mucus transport in the airways and effects of therapeutic interventions in living animals.

High rhinovirus burden in lower airways of children with cystic fibrosis.

PubMed

Kieninger, Elisabeth; Singer, Florian; Tapparel, Caroline; Alves, Marco P; Latzin, Philipp; Tan, Hui-Leng; Bossley, Cara; Casaulta, Carmen; Bush, Andrew; Davies, Jane C; Kaiser, Laurent; Regamey, Nicolas

2013-03-01

Rhinovirus (RV)-induced pulmonary exacerbations are common in cystic fibrosis (CF) and have been associated with impaired virus clearance by the CF airway epithelium in vitro. Here, we assess in vivo the association of RV prevalence and load with antiviral defense mechanisms, airway inflammation, and lung function parameters in children with CF compared with a control group and children with other chronic respiratory diseases. RV presence and load were measured by real-time reverse transcription-polymerase chain reaction in BAL samples and were related to antiviral and inflammatory mediators measured in BAL and to clinical parameters. BAL samples were obtained from children with CF (n = 195), non-CF bronchiectasis (n = 40), or asthma (n = 29) and from a control group (n = 35) at a median (interquartile range [IQR]) age of 8.2 (4.0-11.7) years. RV was detected in 73 samples (24.4%). RV prevalence was similar among groups. RV load (median [IQR] x 10(3) copies/mL) was higher in children with CF (143.0 [13.1-1530.0]), especially during pulmonary exacerbations, compared with children with asthma (3.0 [1.3-25.8], P = .006) and the control group (0.5 [0.3-0.5], P < .001), but similar to patients with non-CF bronchiectasis (122.1 [2.7-4423.5], P = not significant). In children with CF, RV load was negatively associated with interferon (IFN)- b and IFN- l , IL-1ra levels, and FEV 1 , and positively with levels of the cytokines CXCL8 and CXCL10. RV load in CF BAL is high, especially during exacerbated lung disease. Impaired production of antiviral mediators may lead to the high RV burden in the lower airways of children with CF. Whether high RV load is a cause or a consequence of inflammation needs further investigation in longitudinal studies.

Abrogation of Airway Hyperresponsiveness but not Inflammation by Rho kinase Insufficiency

PubMed Central

Kasahara, David I.; Ninin, Fernanda M.C.; Wurmbrand, Allison P.; Liao, James K.; Shore, Stephanie A.

2015-01-01

Background Major features of allergic asthma include airway hyperresponsiveness (AHR), eosinophilic inflammation, and goblet cell metaplasia. Rho kinase (ROCK) is a serine/threonine protein kinase that regulates the actin cytoskeleton. By doing so, it can modulate airway smooth muscle cell contraction and leukocyte migration and proliferation. This study was designed to determine the contributions of the two ROCK isoforms, ROCK1 and ROCK2, to AHR, inflammation and goblet cell metaplasia in a mast-cell dependent model of allergic airways disease. Methods and Results Repeated intranasal challenges with OVA caused AHR, eosinophilic inflammation, and goblet cell hyperplasia in wildtype (WT) mice. OVA-induced AHR was partially or completely abrogated in mice haploinsufficient for ROCK2 (ROCK2+/−) or ROCK1 (ROCK1+/−), respectively. In contrast, there was no effect of ROCK insufficiency on allergic airways inflammation, although both ROCK1 and ROCK2 insufficiency attenuated mast cell degranulation. Goblet cell hyperplasia, as indicated by PAS staining, was not different in ROCK1+/− versus WT mice. However, in ROCK2+/− mice, goblet cell hyperplasia was reduced in medium but not large airways. Maximal acetylcholine-induced force generation was reduced in tracheal rings from ROCK1+/− and ROCK2+/− versus WT mice. The ROCK inhibitor, fasudil, also reduced airway responsiveness in OVA-challenged mice, without affecting inflammatory responses. Conclusion In a mast cell model of allergic airways disease, ROCK1 and ROCK2 both contribute to AHR, likely through direct effects on smooth muscle cell and effects on mast-cell degranulation. In addition, ROCK2 but not ROCK1 plays a role in allergen-induced goblet cell hyperplasia. PMID:25323425

[The research on the airway hyperresponsiveness and IOS airway resistance index of industrial area resident].

PubMed

Xu, Jin; Wang, Zhen; Sun, Hongcun

2015-09-01

To study airway reactivity and impulse oscillation (IOS)-measured airway resistance indicators of residents of Zhenhai industrial area in Ningbo city. In the form of follow-up, both. airway reactivity and respiratory functions of populations in Zhenhai industrial zone (n = 215) and urban (n = 203) were measured, comparing difference degree between different regions. Ninty-five of 215 cases in industrial area were identified as suspected airway hyperresponsiveness, but only 43 of 203 cases were in urban areas. Forty-seven of 95 cases (49.5%) in industrial zone were positive, while only 14 cases (32.6%) in urban. The proportions of people in the two regions on different types of airway hyperresponsiveness were significantly different (P < 0.01). All airway resistance indexes of urban populations were significantly lower than that of industrial zone (P < 0.05). The prevalence of airway hyperresponsiveness and IOS airway resistance aspects of industrial area residents was higher than that of urban residents. Monitoring and evaluating the airway diseases, inflammatory lesions and respiratory function in the region were good for understanding the severe pollution in the local area in certain significance.

The airway microbiota in early cystic fibrosis lung disease.

PubMed

Frayman, Katherine B; Armstrong, David S; Grimwood, Keith; Ranganathan, Sarath C

2017-11-01

Infection plays a critical role in the pathogenesis of cystic fibrosis (CF) lung disease. Over the past two decades, the application of molecular and extended culture-based techniques to microbial analysis has changed our understanding of the lungs in both health and disease. CF lung disease is a polymicrobial disorder, with obligate and facultative anaerobes recovered alongside traditional pathogens in varying proportions, with some differences observed to correlate with disease stage. While healthy lungs are not sterile, differences between the lower airway microbiota of individuals with CF and disease-controls are already apparent in childhood. Understanding the evolution of the CF airway microbiota, and its relationship with clinical treatments and outcome at each disease stage, will improve our understanding of the pathogenesis of CF lung disease and potentially inform clinical management. This review summarizes current knowledge of the early development of the respiratory microbiota in healthy children and then discusses what is known about the airway microbiota in individuals with CF, including how it evolves over time and where future research priorities lie. © 2017 Wiley Periodicals, Inc.

Emergency airway puncture

MedlinePlus

... support for only a very short period of time. Alternative Names Needle cricothyrotomy Images Emergency airway puncture Cricoid cartilage Emergency airway puncture - series References Hebert RB, Bose S, Mace SE. Cricothyrotomy and ...

GS143, an I{kappa}B ubiquitination inhibitor, inhibits allergic airway inflammation in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirose, Koichi; Wakashin, Hidefumi; Oki, Mie

2008-09-26

Asthma is characterized by airway inflammation with intense eosinophil infiltration and mucus hyper-production, in which antigen-specific Th2 cells play critical roles. Nuclear factor-{kappa}B (NF-{kappa}B) pathway has been demonstrated to be essential for the production of Th2 cytokines and chemokines in the airways in murine asthma models. In the present study, we examined the effect of GS143, a novel small-molecule inhibitor of I{kappa}B ubiquitination, on antigen-induced airway inflammation and Th2 cytokine production in mice. Intranasal administration of GS143 prior to antigen challenge suppressed antigen-induced NF-{kappa}B activation in the lung of sensitized mice. Intranasal administration of GS143 also inhibited antigen-induced eosinophil andmore » lymphocyte recruitment into the airways as well as the expression of Th2 cytokines and eotaxin in the airways. Moreover, GS143 inhibited antigen-induced differentiation of Th2 cells but not of Th1 cells in vitro. Taken together, these results suggest that I{kappa}B ubiquitination inhibitor may have therapeutic potential against asthma.« less

Airway mucus, inflammation and remodeling: emerging links in the pathogenesis of chronic lung diseases.

PubMed

Zhou-Suckow, Zhe; Duerr, Julia; Hagner, Matthias; Agrawal, Raman; Mall, Marcus A

2017-03-01

Airway mucus obstruction is a hallmark of many chronic lung diseases including rare genetic disorders such as cystic fibrosis (CF) and primary ciliary dyskinesia, as well as common lung diseases such as asthma and chronic obstructive pulmonary disease (COPD), which have emerged as a leading cause of morbidity and mortality worldwide. However, the role of excess airway mucus in the in vivo pathogenesis of these diseases remains poorly understood. The generation of mice with airway-specific overexpression of epithelial Na + channels (ENaC), exhibiting airway surface dehydration (mucus hyperconcentration), impaired mucociliary clearance (MCC) and mucus plugging, led to a model of muco-obstructive lung disease that shares key features of CF and COPD. In this review, we summarize recent progress in the understanding of causes of impaired MCC and in vivo consequences of airway mucus obstruction that can be inferred from studies in βENaC-overexpressing mice. These studies confirm that mucus hyperconcentration on airway surfaces plays a critical role in the pathophysiology of impaired MCC, mucus adhesion and airway plugging that cause airflow obstruction and provide a nidus for bacterial infection. In addition, these studies support the emerging concept that excess airway mucus per se, probably via several mechanisms including hypoxic epithelial necrosis, retention of inhaled irritants or allergens, and potential immunomodulatory effects, is a potent trigger of chronic airway inflammation and associated lung damage, even in the absence of bacterial infection. Finally, these studies suggest that improvement of mucus clearance may be a promising therapeutic strategy for a spectrum of muco-obstructive lung diseases.

Exposure to Ozone Modulates Human Airway Protease/Antiprotease Balance Contributing to Increased Influenza A Infection

PubMed Central

Kesic, Matthew J.; Meyer, Megan; Bauer, Rebecca; Jaspers, Ilona

2012-01-01

Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility. PMID

Coordination of Cellular Dynamics Contributes to Tooth Epithelium Deformations

PubMed Central

Morita, Ritsuko; Kihira, Miho; Nakatsu, Yousuke; Nomoto, Yohei; Ogawa, Miho; Ohashi, Kazumasa; Mizuno, Kensaku; Tachikawa, Tetsuhiko; Ishimoto, Yukitaka; Morishita, Yoshihiro; Tsuji, Takashi

2016-01-01

The morphologies of ectodermal organs are shaped by appropriate combinations of several deformation modes, such as invagination and anisotropic tissue elongation. However, how multicellular dynamics are coordinated during deformation processes remains to be elucidated. Here, we developed a four-dimensional (4D) analysis system for tracking cell movement and division at a single-cell resolution in developing tooth epithelium. The expression patterns of a Fucci probe clarified the region- and stage-specific cell cycle patterns within the tooth germ, which were in good agreement with the pattern of the volume growth rate estimated from tissue-level deformation analysis. Cellular motility was higher in the regions with higher growth rates, while the mitotic orientation was significantly biased along the direction of tissue elongation in the epithelium. Further, these spatio-temporal patterns of cellular dynamics and tissue-level deformation were highly correlated with that of the activity of cofilin, which is an actin depolymerization factor, suggesting that the coordination of cellular dynamics via actin remodeling plays an important role in tooth epithelial morphogenesis. Our system enhances the understanding of how cellular behaviors are coordinated during ectodermal organogenesis, which cannot be observed from histological analyses. PMID:27588418

Corneal epithelium and UV-protection of the eye.

PubMed

Ringvold, A

1998-04-01

To study UV-absorption and UV-induced fluorescence in the bovine corneal epithelium. Spectrophotometry and spectrofluorimetry. The corneal epithelium absorbs UV-B radiation mainly owing to its content of protein, RNA, and ascorbate. Some of the absorbed energy is transformed to the less biotoxic UV-A radiation by fluorescence. RNA and ascorbate reduce tissue fluorescence. The corneal epithelium acts as a UV-filter, protecting internal eye structures through three different mechanisms: (1) Absorption of UV-B roughly below 310 nm wavelength. (2) Fluorescence-mediated ray transformation to longer wavelengths. (3) Fluorescence reduction. The extremely high ascorbate concentration in the corneal epithelium has a key role in two of these processes.

Allergic Sensitization through the Airway Primes Th17-dependent Neutrophilia and Airway Hyperresponsiveness

PubMed Central

Wilson, Rhonda H.; Whitehead, Gregory S.; Nakano, Hideki; Free, Meghan E.; Kolls, Jay K.; Cook, Donald N.

2009-01-01

Rationale: In humans, immune responses to inhaled aeroallergens develop in the lung and draining lymph nodes. Many animal models of asthma bypass this route and instead use intraperitoneal injections of allergen using aluminum hydroxide as an adjuvant. Objectives: We investigated whether allergic sensitization through the airway elicits immune responses qualitatively different than those arising in the peritoneum. Methods: Mice were sensitized to allergen through the airway using low-dose LPS as an adjuvant, or through the peritoneum using aluminum hydroxide as an adjuvant. After a single allergen challenge, ELISA and flow cytometry were used to measure cytokines and leukocyte subsets. Invasive measurements of airway resistance were used to measure allergen-induced airway hyperreactivity (AHR). Measurements and Main Results: Sensitization through the peritoneum primed strong Th2 responses and eosinophilia, but not AHR, after a single allergen challenge. By contrast, allergic sensitization through the airway primed only modest Th2 responses, but strong Th17 responses. Th17 cells homed to the lung and released IL-17 into the airway on subsequent encounter with inhaled allergen. As a result, these mice developed IL-17–dependent airway neutrophilia and AHR. This AHR was neutrophil-dependent because it was abrogated in CXCR2-deficient mice and also in wild-type mice receiving a neutrophil-depleting antibody. Individually, neither IL-17 nor ongoing Th2 responses were sufficient to confer AHR, but together they acted synergistically to promote neutrophil recruitment, eosinophil recruitment and AHR. Conclusions: Allergic sensitization through the airway primes modest Th2 responses but strong Th17 responses that promote airway neutrophilia and acute AHR. These findings support a causal role for neutrophils in severe asthma. PMID:19661246

Careers in Airway Science.

ERIC Educational Resources Information Center

Federal Aviation Administration (DOT), Washington, DC.

The Federal Aviation Administration (FAA) has initiated the Airway Science curriculum as a method of preparing the next generation of aviation technicians and managers. This document: (1) discusses the FAA's role in the Airway Science program; (2) describes some of the career fields that FAA offers to Airway Science graduates (air traffic control…

THE PERMEABILITY OF RAT TRANSITIONAL EPITHELIUM

PubMed Central

Hicks, R. M.

1966-01-01

Permeability barriers must exist in transitional epithelium to prevent the free flow of water from underlying blood capillaries through the epithelium into the hypertonic urine, and such a barrier has now been demonstrated in isolated bladders. This barrier is passive in function and can be destroyed by damaging the luminal surface of the transitional epithelium with sodium hydroxide and 8 M urea solutions, by digesting it with trypsin, lecithinase C, and lecithinase D, or by treating it with lipid solvents such as Triton x 100 and saponin. From this it is concluded that the barrier depends on the integrity of lipoprotein cell membranes. The barrier function is also destroyed by sodium thioglycollate solutions, and electron microscope investigations show that sodium thioglycollate damages the thick asymmetric membrane which limits the luminal face of the superficial squamous cell. Cytochemical staining shows the epithelium to contain disulfide and thiol groups and to have a concentration of these groups at the luminal margin of the superficial cells. It thus appears that the permeability barrier also depends on the presence of disulfide bridges in the epithelium, and it is presumed that these links are located in keratin. Because of the effect of thioglycollates, both on the barrier function and on the morphology of the membrane, it is suggested that keratin may be incorporated in the thick barrier membrane. It is proposed that the cells lining the urinary bladder and ureters should be regarded as a keratinizing epitheluim. PMID:5901498

Corneal epithelium, visual acuity, and laser refractive keratectomy

NASA Astrophysics Data System (ADS)

Simon, Gabriel; Parel, Jean-Marie A.; Kervick, Gerard N.; Rol, Pascal O.; Hanna, Khalil; Thompson, Keith P.

1991-06-01

Photorefractive keratectomy (PRK) using an argon fluoride excimer laser for photoablation of the cornea shows potential for the precise correction of refractive errors in patients. Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed depths and shapes that are based on known ablation rates for these tissues. After four day's time, the epithelium has regrown. Assuming the epithelium to be preoperatively uniform in thickness across the central optical zone, and assuming that it regrows to the same thickness, a theoretical precision of +/- 0.05 diopters is achievable with PRK. Keratometric measurements of the epithelium and of Bowman's layer were made at the 2.0 and 3.6 mm optical zones on 10 fresh cadaver eyes (<21 hours postmortem). In the eyes studied, the epithelium thickness was found to vary across the central optical zone, accounting for the measured refractive differences of 0.5 to 1.8 diopters. Bowman's layer was found to be more prolated than the epithelial surface (ratios: 1.005 compared to 1.033). In addition, the surface of Bowman's layer had a larger degree of astigmatism. Other studies have shown that the epithelium regrowth is a function of the newly exposed corneal topography as the wing cells compensate for irregularities in Bowman's surface. As the preoperative topography of the epithelium cannot be used as a reference surface when computing photoablation depth, intraoperative keratometry of Bowman's surface becomes a necessity in PRK.

Curcumin regulates airway epithelial cell cytokine responses to the pollutant cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rennolds, Jessica; Malireddy, Smitha; Hassan, Fatemat

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 cadmiummore » 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.« less

Mast cells in airway diseases and interstitial lung disease.

PubMed

Cruse, Glenn; Bradding, Peter

2016-05-05

Mast cells are major effector cells of inflammation and there is strong evidence that mast cells play a significant role in asthma pathophysiology. There is also a growing body of evidence that mast cells contribute to other inflammatory and fibrotic lung diseases such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. This review discusses the role that mast cells play in airway diseases and highlights how mast cell microlocalisation within specific lung compartments and their cellular interactions are likely to be critical for their effector function in disease. Published by Elsevier B.V.

Development and maintenance of force and stiffness in airway smooth muscle.

PubMed

Lan, Bo; Norris, Brandon A; Liu, Jeffrey C-Y; Paré, Peter D; Seow, Chun Y; Deng, Linhong

2015-03-01

Airway smooth muscle (ASM) plays a central role in the excessive narrowing of the airway that characterizes the primary functional impairment in asthma. This phenomenon is known as airway hyper-responsiveness (AHR). Emerging evidence suggests that the development and maintenance of ASM force involves dynamic reorganization of the subcellular filament network in both the cytoskeleton and the contractile apparatus. In this review, evidence is presented to support the view that regulation of ASM contraction extends beyond the classical actomyosin interaction and involves processes within the cytoskeleton and at the interfaces between the cytoskeleton, the contractile apparatus, and the extracellular matrix. These processes are initiated when the muscle is activated, and collectively they cause the cytoskeleton and the contractile apparatus to undergo structural transformation, resulting in a more connected and solid state that allows force generated by the contractile apparatus to be transmitted to the extracellular domain. Solidification of the cytoskeleton also serves to stiffen the muscle and hence the airway. Oscillatory strain from tidal breathing and deep inspiration is believed to be the counter balance that prevents hypercontraction and stiffening of ASM in vivo. Dysregulation of this balance could lead to AHR seen in asthma.

Neurotoxic, inflammatory, and mucosecretory responses in the nasal airways of mice repeatedly exposed to the macrocyclic trichothecene mycotoxin roridin A: dose-response and persistence of injury.

PubMed

Corps, Kara N; Islam, Zahidul; Pestka, James J; Harkema, Jack R

2010-04-01

Macrocyclic trichothecene mycotoxins encountered in water-damaged buildings have been suggested to contribute to illnesses of the upper respiratory tract. Here, the authors characterized the adverse effects of repeated exposures to roridin A (RA), a representative macrocyclic trichothecene, on the nasal airways of mice and assessed the persistence of these effects. Young, adult, female C57BL/6 mice were exposed to single daily, intranasal, instillations of RA (0.4, 2, 10, or 50 microg/kg body weight [bw]) in saline (50 microl) or saline alone (controls) over 3 weeks or 250 microg/kg RA over 2 weeks. Histopathologic, immunohistochemical, and morphometric analyses of nasal airways conducted 24 hr after the last instillation revealed that the lowest-effect level was 10 microg/kg bw. RA exposure induced a dose-dependent, neutrophilic rhinitis with mucus hypersecretion, atrophy and exfoliation of nasal transitional and respiratory epithelium, olfactory epithelial atrophy and loss of olfactory sensory neurons (OSNs). In a second study, the persistence of lesions in mice instilled with 250 microg/kg bw RA was assessed. Nasal inflammation and excess luminal mucus were resolved after 3 weeks, but OSN loss was still evident in olfactory epithelium (OE). These results suggest that nasal inflammation, mucus hypersecretion, and olfactory neurotoxicity could be important adverse health effects associated with short-term, repeated, airborne exposures to macrocyclic trichothecenes.

Relapsing polychondritis and airway involvement.

PubMed

Ernst, Armin; Rafeq, Samaan; Boiselle, Phillip; Sung, Arthur; Reddy, Chakravarthy; Michaud, Gaetane; Majid, Adnan; Herth, Felix J F; Trentham, David

2009-04-01

To assess the prevalence and characteristics of airway involvement in relapsing polychondritis (RP). Retrospective chart review and data analysis of RP patients seen in the Rheumatology Clinic and the Complex Airway Center at Beth Israel Deaconess Medical Center from January 2004 through February 2008. RP was diagnosed in 145 patients. Thirty-one patients had airway involvement, a prevalence of 21%. Twenty-two patients were women (70%), and they were between 11 and 61 years of age (median age, 42 years) at the time of first symptoms. Airway symptoms were the first manifestation of disease in 17 patients (54%). Dyspnea was the most common symptom in 20 patients (64%), followed by cough, stridor, and hoarseness. Airway problems included the following: subglottic stenosis (n = 8; 26%); focal and diffuse malacia (n = 15; 48%); and focal stenosis in different areas of the bronchial tree in the rest of the patients. Twelve patients (40%) required and underwent intervention including balloon dilatation, stent placement, tracheotomy, or a combination of the above with good success. The majority of patients experienced improvement in airway symptoms after intervention. One patient died during the follow-up period from the progression of airway disease. The rest of the patients continue to undergo periodic evaluation and intervention. In this largest cohort described in the English language literature, we found symptomatic airway involvement in RP to be common and at times severe. The nature of airway problems is diverse, with tracheomalacia being the most common. Airway intervention is frequently required and in experienced hands results in symptom improvement.

Airway recovery after face transplantation.

PubMed

Fischer, Sebastian; Wallins, Joe S; Bueno, Ericka M; Kueckelhaus, Maximilian; Chandawarkar, Akash; Diaz-Siso, J Rodrigo; Larson, Allison; Murphy, George F; Annino, Donald J; Caterson, Edward J; Pomahac, Bohdan

2014-12-01

Severe facial injuries can compromise the upper airway by reducing airway volume, obstructing or obliterating the nasal passage, and interfering with oral airflow. Besides the significant impact on quality of life, upper airway impairments can have life-threatening or life-altering consequences. The authors evaluated improvements in functional airway after face transplantation. Between 2009 and 2011, four patients underwent face transplantation at the authors' institution, the Brigham and Women's Hospital. Patients were examined preoperatively and postoperatively and their records reviewed for upper airway infections and sleeping disorders. The nasal mucosa was biopsied after face transplantation and analyzed using scanning electron microscopy. Volumetric imaging software was used to evaluate computed tomographic scans of the upper airway and assess airway volume changes before and after transplantation. Before transplantation, two patients presented an exposed naked nasal cavity and two suffered from occlusion of the nasal passage. Two patients required tracheostomy tubes and one had a prosthetic nose. Sleeping disorders were seen in three patients, and chronic cough was diagnosed in one. After transplantation, there was no significant improvement in sleeping disorders. The incidence of sinusitis increased because of mechanical interference of the donor septum and disappeared after surgical correction. All patients were decannulated after transplantation and were capable of nose breathing. Scanning electron micrographs of the respiratory mucosa revealed viable tissue capable of mucin production. Airway volume significantly increased in all patients. Face transplantation successfully restored the upper airway in four patients. Unhindered nasal breathing, viable respiratory mucosa, and a significant increase in airway volume contributed to tracheostomy decannulation.

Effects of multi-walled carbon nanotubes on a murine allergic airway inflammation model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inoue, Ken-ichiro; Koike, Eiko; Yanagisawa, Rie

The development of nanotechnology has increased the risk of exposure to types of particles other than combustion-derived particles in the environment, namely, industrial nanomaterials. On the other hand, patients with bronchial asthma are sensitive to inhaled substances including particulate matters. This study examined the effects of pulmonary exposure to a type of nano-sized carbon nanotube (multi-walled nanotubes: MWCNT) on allergic airway inflammation in vivo and their cellular mechanisms in vitro. In vivo, ICR mice were divided into 4 experimental groups. Vehicle, MWCNT (50 {mu}g/animal), ovalbumin (OVA), and OVA + MWCNT were repeatedly administered intratracheally. Bronchoalveolar lavage (BAL) cellularity, lung histology,more » levels of cytokines related to allergic inflammation in lung homogenates/BAL fluids (BALFs), and serum immunoglobulin levels were studied. Also, we evaluated the impact of MWCNT (0.1-1 {mu}g/ml) on the phenotype and function of bone marrow-derived dendritic cells (DC) in vitro. MWCNT aggravated allergen-induced airway inflammation characterized by the infiltration of eosinophils, neutrophils, and mononuclear cells in the lung, and an increase in the number of goblet cells in the bronchial epithelium. MWCNT with allergen amplified lung protein levels of Th cytokines and chemokines compared with allergen alone. MWCNT exhibited adjuvant activity for allergen-specific IgG{sub 1} and IgE. MWCNT significantly increased allergen (OVA)-specific syngeneic T-cell proliferation, particularly at a lower concentration in vitro. Taken together, MWCNT can exacerbate murine allergic airway inflammation, at least partly, via the promotion of a Th-dominant milieu. In addition, the exacerbation may be partly through the inappropriate activation of antigen-presenting cells including DC.« less

Inhibition of TRPC3 downregulates airway hyperresponsiveness, remodeling of OVA-sensitized mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lingwei; Li, Jie; Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou

Airway hyperresponsiveness (AHR), airway remodeling and inflammation are the fundamental pathological alterations that occur in asthma. Transient receptor potential canonical 3 (TRPC3) has been implicated in diverse functions of airway smooth muscle cells (ASMCs) in asthma. However, the underlying mechanisms remain incompletely understood. We investigated the mRNA and protein expression of TRPC3 in ASMCs from normal and OVA-sensitized mouse. And the effects of inhibition or knockdown of TRPC3 with Ethyl-1- (4- (2,3,3-trichloroacrylamide) phenyl) −5 - (trifluoromethyl) -1H -pyrazole -4-carboxylate (Pyr3) and lentiviral shRNA on OVA-sensitized mouse AHR, airway remodeling, circulating inflammatory cytokines, cell proliferation and migration. We found that TRPC3 mRNAmore » and protein expression levels were significantly increased in ASMCs from OVA-sensitized mouse. Inhibiting TRPC3 with continuous subcutaneous administration of Pyr3 decreased enhanced pause (Penh) of OVA-sensitized mouse. Meanwhile, both Pyr3 and lentiviral shRNA treatment of ASMCs in OVA-sensitized mouse significantly decreased their proliferation and migration. These results suggest that TRPC3 plays a critical role in asthma and represents a promising new target for asthma treatment. - Highlights: • Penh, airway remodeling and the gene expression and protein of TRPC3 are increased in OVA-sensitized mice. • Inhibition of TRPC3 suppresses the OVA-sensitized mice Penh and airway remodeling. • Inhibition of TRPC3 decreases OVA-sensitized mice ASMC proliferation and migration.« less

The Immunoexpression of Glucocorticoid Receptors in Breast Carcinomas, Lactational Change, and Normal Breast Epithelium and Its Possible Role in Mammary Carcinogenesis

PubMed Central

Wazir, Javed Fayyaz; Brahmi, Urmil Prabha; Fakhro, Abdul Rahman

2017-01-01

The role of estrogen and progesterone receptors in breast cancer biology is well established. In contrast, other steroid hormones are less well studied. Glucocorticoids (GCs) are known to play a role in mammary development and differentiation; thus, it is of interest to attempt to delineate their immunoexpression across a spectrum of mammary epithelia. Aim. To delineate the distribution pattern of glucocorticoid receptors (GRs) in malignant versus nonmalignant epithelium with particular emphasis on lactational epithelium. Materials and Methods. Immunohistochemistry (IHC) for GRs was performed on archival formalin-fixed paraffin-embedded tissue blocks of 96 cases comprising 52 invasive carcinomas, 21 cases with lactational change, and 23 cases showing normal mammary tissue histology. Results. Results reveal an overexpression of GRs in mammary malignant epithelium as compared to both normal and lactational groups individually and combined. GR overexpression is significantly more pronounced in HER-2-negative cancers. Discussion. This is the first study to compare GR expression in human lactating epithelium versus malignant and normal epithelium. The article discusses the literature related to the pathobiology of GCs in the breast with special emphasis on breast cancer. Conclusion. The lactational epithelium did not show overexpression of GR, while GR was overexpressed in mammary NST (ductal) carcinoma, particularly HER-2-negative cancers. PMID:29348941

Effect of neutral endopeptidase inhibition on substance-P-induced increase in short-circuit current of canine cultured tracheal epithelium.

PubMed

Tamaoki, J; Sakai, N; Isono, K; Kanemura, T; Chiyotani, A; Yamauchi, F; Takizawa, T; Konno, K

1991-01-01

We studied the effect of substance P (SP) on the electric properties of cultured canine tracheal epithelium and its possible modulation by neutral endopeptidase (NEP) by Ussing's short-circuited technique in vitro. Addition of SP (5 x 10(-6) M) to the mucosal side increased short-circuit current (SCC) from 5.1 +/- 0.9 to 10.3 +/- 2.2 microA/cm2 (mean +/- SE; p less than 0.01), which was accompanied by increases in transepithelial potential difference and conductance. The effect of the mucosal SP on SCC was dose-dependent, with the maximal increase from the baseline value being 5.8 +/- 1.0 microA/cm2 observed at 5 x 10(-5) M. The NEP inhibitor phosphoramidon (10(-5) M) did not affect these responses. On the other hand, SCC was not altered by the addition of SP to the submucosal side. However, it was increased dose-dependently in the presence of phosphoramidon (10(-5) M) but not in the presence of captopril, bestatin or leupeptin. This stimulatory effect of submucosal SP was abolished by furosemide, diphenylamine-2-carboxylate and Cl-free medium, but not by amiloride. These results suggest that SP may selectively stimulate Cl secretion across the airway epithelium and that this effect may be modulated by submucosal NEP.

[Quality assurance in airway management: education and training for difficult airway management].

PubMed

Kaminoh, Yoshiroh

2006-01-01

Respiratory problem is one of the main causes of death or severe brain damage in perioperative period. Three major factors of respiratory problem are esophageal intubation, inadequate ventilation, and difficult airway. The wide spread of pulse oximeter and capnograph reduced the incidences of esophageal intubation and inadequate ventilation, but the difficult airway still occupies the large portion in the causes of adverse events during anesthesia. "Practice guideline for management of the difficult airway" was proposed by American Society of Anesthesiologists (ASA) in 1992 and 2002. Improvement of knowledge, technical skills, and cognitive skills are necessary for the education and training of the difficult airway management. "The practical seminar of difficult airway management (DAM practical seminar)" has been cosponsored by the Japanese Association of Medical Simulation (JAMS) in the 51 st and 52 nd annual meetings of Japanese Society of Anesthesiologists and the 24th annual meeting of Japanese Society for Clinical Anesthesia. The DAM practical seminar is composed of the lecture session for ASA difficult airway algorithm, the hands-on training session for technical skills, and the scenario-based training session for cognitive skills. Ninty six Japanese anesthesiologists have completed the DAM practical seminar in one year. "The DAM instructor course" should be immediately prepared to organize the seminar more frequently.

Neurokinin-neurotrophin interactions in airway smooth muscle

PubMed Central

Meuchel, Lucas W.; Stewart, Alecia; Smelter, Dan F.; Abcejo, Amard J.; Thompson, Michael A.; Zaidi, Syed I. A.; Martin, Richard J.

2011-01-01

Neurally derived tachykinins such as substance P (SP) play a key role in modulating airway contractility (especially with inflammation). Separately, the neurotrophin brain-derived neurotrophic factor (BDNF; potentially derived from nerves as well as airway smooth muscle; ASM) and its tropomyosin-related kinase receptor, TrkB, are involved in enhanced airway contractility. In this study, we hypothesized that neurokinins and neurotrophins are linked in enhancing intracellular Ca2+ concentration ([Ca2+]i) regulation in ASM. In rat ASM cells, 24 h exposure to 10 nM SP significantly increased BDNF and TrkB expression (P < 0.05). Furthermore, [Ca2+]i responses to 1 μM ACh as well as BDNF (30 min) effects on [Ca2+]i regulation were enhanced by prior SP exposure, largely via increased Ca2+ influx (P < 0.05). The enhancing effect of SP on BDNF signaling was blunted by the neurokinin-2 receptor antagonist MEN-10376 (1 μM, P < 0.05) to a greater extent than the neurokinin-1 receptor antagonist RP-67580 (5 nM). Chelation of extracellular BDNF (chimeric TrkB-Fc; 1 μg/ml), as well as tyrosine kinase inhibition (100 nM K252a), substantially blunted SP effects (P < 0.05). Overnight (24 h) exposure of ASM cells to 50% oxygen increased BDNF and TrkB expression and potentiated both SP- and BDNF-induced enhancement of [Ca2+]i (P < 0.05). These results suggest a novel interaction between SP and BDNF in regulating agonist-induced [Ca2+]i regulation in ASM. The autocrine mechanism we present here represents a new area in the development of bronchoconstrictive reflex response and airway hyperreactive disorders. PMID:21515660

Prevalence of ciliated epithelium in apical periodontitis lesions.

PubMed

Ricucci, Domenico; Loghin, Simona; Siqueira, José F; Abdelsayed, Rafik A

2014-04-01

This article reports on the morphologic features and the frequency of ciliated epithelium in apical cysts and discusses its origin. The study material consisted of 167 human apical periodontitis lesions obtained consecutively from patients presenting for treatment during a period of 12 years in a dental practice operated by one of the authors. All of the lesions were obtained still attached to the root apices of teeth with untreated (93 lesions) or treated canals (74 lesions). The former were obtained by extraction and the latter by extraction or apical surgery. Specimens were processed for histopathologic and histobacteriologic analyses. Lesions were classified, and the type of epithelium, if present, was recorded. Of the lesions analyzed, 49 (29%) were diagnosed as cysts. Of these, 26 (53%) were found in untreated teeth, and 23 (47%) related to root canal-treated teeth. Ciliated columnar epithelium was observed partially or completely lining the cyst wall in 4 cysts, and all of them occurred in untreated maxillary molars. Three of these lesions were categorized as pocket cysts, and the other was a true cyst. Ciliated columnar epithelium-lined cysts corresponded to approximately 2% of the apical periodontitis lesions and 8% of the cysts of endodontic origin in the population studied. This epithelium is highly likely to have a sinus origin in the majority of cases. However, the possibility of prosoplasia or upgraded differentiation into ciliated epithelium from the typical cystic lining squamous epithelium may also be considered. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Airway malacia in children with achondroplasia.

PubMed

Dessoffy, Kimberly E; Modaff, Peggy; Pauli, Richard M

2014-02-01

This study was undertaken to assess the frequency of airway malacia in infants and young children with achondroplasia, a population well known to be at risk for a variety of respiratory problems. We also wished to evaluate what, if any, contribution airway malacia makes to the complex respiratory issues that may be present in those with achondroplasia. Retrospective chart review of all infants and young children with achondroplasia who were assessed through the Midwest Regional Bone Dysplasia Clinics from 1985 through 2012 (n = 236) was completed. Records of comprehensive clinical examinations, polysomnographic assessments, and airway visualization were reviewed and abstracted using a data collection form. Analyses were completed comparing the group with and those without evidence for airway malacia. Thirteen of 236 patients (5.5%) were found to have airway malacia. Most of those affected had lower airway involvement (9/13). The presence of airway malacia was correlated with an increased occurrence of obstructive sleep apnea as well as need for oxygen supplementation, airway surgeries and tracheostomy placement. Although estimates of the frequency of airway malacia in the general population are limited, its frequency in children with achondroplasia appears to be much higher than any published general population estimate. The presence of airway malacia appears to confound other breathing abnormalities in this population and results in the need for more invasive airway treatments. © 2013 Wiley Periodicals, Inc.

The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity

PubMed Central

Workman, Alan D.; Palmer, James N.; Adappa, Nithin D.

2016-01-01

Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function. PMID:26492878

Extraglottic airway devices: technology update.

PubMed

Sharma, Bimla; Sahai, Chand; Sood, Jayashree

2017-01-01

Extraglottic airway devices (EADs) have revolutionized the field of airway management. The invention of the laryngeal mask airway was a game changer, and since then, there have been several innovations to improve the EADs in design, functionality, safety and construction material. These have ranged from changes in the shape of the mask, number of cuffs and material used, like rubber, polyvinylchloride and latex. Phthalates, which were added to the construction material in order to increase device flexibility, were later omitted when this chemical was found to have serious adverse reproductive outcomes. The various designs brought out by numerous companies manufacturing EADs resulted in the addition of several devices to the airway market. These airway devices were put to use, many of them with inadequate or no evidence base regarding their efficacy and safety. To reduce the possibility of compromising the safety of the patient, the Difficult Airway Society (DAS) formed the Airway Device Evaluation Project Team (ADEPT) to strengthen the evidence base for airway equipment and vet the new extraglottic devices. A preuse careful analysis of the design and structure may help in better understanding of the functionality of a particular device. In the meantime, the search for the ideal EAD continues.

Airway Protective Mechanisms

PubMed Central

Pitts, Teresa

2014-01-01

Cough and swallow are highly coordinated reflex behaviors whose common purpose is to protect the airway. The pharynx is the common tube for air and food/liquid movement from the mouth into the thorax, has been largely overlooked, and is potentially seen as just a passive space. The thyropharyngeus muscle responds to cough inducing stimuli to prepare a transient holding area for material that has been removed from the subglottic airway. The cricopharyngeus muscle participates with the larynx to ensure regulation of pressure when a bolus/air is moving from the upper airway through to the thorax (i.e inspiration or swallow) or the reverse (i.e expiration reflex or vomiting).These vital mechanisms have not been evaluated in clinical conditions, but could be impaired in many neurodegenerative diseases leading to aspiration pneumonia. These newly described airway protective mechanisms need further study, especially in healthy and pathologic human populations. PMID:24297325

The effect of body weight on distal airway function and airway inflammation.

PubMed

van de Kant, Kim D G; Paredi, Paolo; Meah, Sally; Kalsi, Harpal S; Barnes, Peter J; Usmani, Omar S

Obesity is a global health problem that adversely influences the respiratory system. We assessed the effects of body mass index (BMI) on distal airway function and airway inflammation. Impulse oscillometry (IOS) as a measure of distal airway function, together with spirometry, were assessed in adults with a range of different BMIs. Airway inflammation was assessed with the fraction of exhaled nitric oxide (FeNO) and participants exhaled at various exhalation flows to determine alveolar and bronchial NO. In total 34 subjects were enrolled in the study; 19 subjects had a normal BMI (18.50-24.99), whilst 15 subjects were overweight (BMI 25.00-29.99), or obese (BMI ≥30). All subjects had normal spirometry. However, IOS measures of airway resistance (R) at 5Hz, 20Hz and frequency dependence (R 5-20 ) were elevated in overweight/obese individuals, compared to subjects with a normal BMI (median (interquartile range)); 5Hz: 0.41 (0.37, 0.45) vs. 0.32 (0.30, 0.37)kPa/l/s; 20Hz: 0.34 (0.30, 0.37) vs. 0.30 (0.26, 0.33)kPa/l/s; R 5-20 : 0.06 (0.04, 0.11) vs. 0.03 (0.01, 0.05)kPa/l/s; p<0.05), whereas airway reactance at 20Hz was decreased in overweight/obese individuals (20Hz: 0.07 (0.03, 0.09) vs. 0.10 (0.07, 0.13)kPa/l/s, p=0.009; 5Hz: -0.12 (-0.15, -0.10) vs. -0.10 (-0.13, -0.09)kPa/l/s, p=0.07). In contrast, within-breath IOS measures (a sign of expiratory flow limitation) and FeNO inflammatory measures, did not differ between groups (p>0.05). Being overweight has significant effects on distal and central airway function as determined by IOS, which is not detected by spirometry. Obesity does not influence airway inflammation as measured by FeNO. IOS is a reliable technique to identify airway abnormalities in the presence of normal spirometry in overweight people. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Definitive airway management after pre-hospital supraglottic airway insertion: Outcomes and a management algorithm for trauma patients.

PubMed

Hernandez, Matthew C; Aho, Johnathon M; Zielinski, Martin D; Zietlow, Scott P; Kim, Brian D; Morris, David S

2018-01-01

Prehospital airway management increasingly involves supraglottic airway insertion and a paucity of data evaluates outcomes in trauma populations. We aim to describe definitive airway management in traumatically injured patients who necessitated prehospital supraglottic airway insertion. We performed a single institution retrospective review of multisystem injured patients (≥15years) that received prehospital supraglottic airway insertion during 2009 to 2016. Baseline demographics, number and type of: supraglottic airway insertion attempts, definitive airway and complications were recorded. Primary outcome was need for tracheostomy. Univariate and multivariable statistics were performed. 56 patients met inclusion criteria and were reviewed, 78% were male. Median age [IQR] was 36 [24-56] years. Injuries comprised blunt (94%), penetrating (4%) and burns (2%). Median ISS was 26 [22-41]. Median number of prehospital endotracheal intubation (PETI) attempts was 2 [1-3]. Definitive airway management included: (n=20, 36%, tracheostomy), (n=10, 18%, direct laryngoscopy), (n=6, 11%, bougie), (n=9, 15%, Glidescope), (n=11, 20%, bronchoscopic assistance). 24-hour mortality was 41%. Increasing number of PETI was associated with increasing facial injury. On regression, increasing cervical and facial injury patterns as well as number of PETI were associated with definitive airway control via surgical tracheostomy. After supraglottic airway insertion, operative or non-operative approaches can be utilized to obtain a definitive airway. Patients with increased craniofacial injuries have an increased risk for airway complications and need for tracheostomy. We used these factors to generate an evidence based algorithm that requires prospective validation. Level IV - Retrospective study. Retrospective single institution study. Copyright © 2017 Elsevier Inc. All rights reserved.

A texture analysis method for MR images of airway dilator muscles: a feasibility study

PubMed Central

Järnstedt, J; Sikiö, M; Viik, J; Dastidar, P; Peltomäki, T; Eskola, H

2014-01-01

Objectives: Airway dilator muscles play an important role in the analysis of breathing-related symptoms, such as obstructive sleep apnoea. Texture analysis (TA) provides a new non-invasive method for analysing airway dilator muscles. In this study, we propose a TA methodology for airway dilator muscles and prove the robustness of this method. Methods: 15 orthognathic surgery patients underwent 3-T MRI. Computerized TA was performed on 20 regions of interest (ROIs) in the patients' airway dilator muscles. 53 texture parameters were calculated for all ROIs. The robustness of the TA method was analysed by altering the locations, sizes and shapes of the ROIs. Results: Our study shows that there is significant difference in TA results as the size or shape of ROI changes. The change of location of the ROI inside the studied muscle does not affect the TA results. Conclusions: The TA method is valid for airway dilator muscles. We propose a methodology in which the number of co-occurrence parameters is reduced by using mean values from four different directions (0°, 45°, 90° and 135°) with pixel spacing of 1 pixel. PMID:24773626

Acute and Chronic Changes in the Subglottis Induced by Graded CO2 Laser Injury in the Rabbit Airway*

PubMed Central

Otteson, Todd D.; Sandulache, Vlad C.; Barsic, Mark; DiSilvio, Gregory M.; Hebda, Patricia A.; Dohar, Joseph E.

2010-01-01

Objective To investigate the repair process following CO2 laser injury to the upper airway mucosa (UAM) during the development of chronic subglottic stenosis (SGS). Design Animals were assigned to either sham control (cricothyroidotomy only) or injured (cricothyroidotomy and posterior subglottic laser) groups using various CO2 laser exposures (8W, 12W, 16W) for 4 seconds. Subjects 24 New Zealand white rabbits. Interventions The subglottis was approached via cricothyroidotomy. Sham control airways were immediately closed while injured airways were subjected to graded CO2 laser exposures prior to closure. Airways were endoscopically monitored preoperatively, postoperatively, and on postoperative days 7,14,28,42,56,70 and 84. Animals were sacrificed at 14 and 84 days. Subglottic tissue was harvested for histological evaluation (re-epithelialization, extracellular matrix, vascularity and inflammation). Results 1) Increases in UAM thickness up to five times thicker than normal mucosa were observed, but were limited primarily to the lamina propria. The mucosal epithelium regenerated without chronic changes. Focal areas of cartilage repair were encountered acutely post-injury and to a greater extent in the chronic phases of repair. 2) Acutely, the thickened lamina propria was comprised of poorly organized extracellular matrix components and demonstrated increases in blood vessel size and number. 3) Histological changes present in the acute phase only partially resolved in progression to chronic SGS. Chronic SGS was characterized by thick collagen fiber bundles extending into the remodeled subglottic cartilage. Conclusions The CO2 laser induces acute changes to lamina propria architecture and vascularity which persist chronically. Elucidating responsible signaling pathways may facilitate the development of therapeutic agents to prevent or reduce the formation of SGS. PMID:18645117

Inhalation of honey reduces airway inflammation and histopathological changes in a rabbit model of ovalbumin-induced chronic asthma.

PubMed

Kamaruzaman, Nurfatin Asyikhin; Sulaiman, Siti Amrah; Kaur, Gurjeet; Yahaya, Badrul

2014-05-29

Honey is widely used in folk medicine to treat cough, fever, and inflammation. In this study, the effect of aerosolised honey on airway tissues in a rabbit model of ovalbumin (OVA)-induced asthma was investigated. The ability of honey to act either as a rescuing agent in alleviating asthma-related symptoms or as a preventive agent to preclude the occurrence of asthma was also assessed. Forty New Zealand white rabbits were sensitized twice with mixture of OVA and aluminium hydroxide on days 1 and 14. Honey treatments were given from day 23 to day 25 at two different doses (25% (v/v) and 50% (v/v) of honey diluted in sterile phosphate buffer saline. In the aerosolised honey as a rescue agent group, animals were euthanized on day 28; for the preventive group, animals were further exposed to aerosolised OVA for 3 days starting from day 28 and euthanized on day 31. The effects of honey on inflammatory cell response, airway inflammation, and goblet cell hyperplasia were assessed for each animal. Histopathological analyses revealed that aerosolised honey resulted in structural changes of the epithelium, mucosa, and submucosal regions of the airway that caused by the induction with OVA. Treatment with aerosolised honey has reduced the number of airway inflammatory cells present in bronchoalveolar lavage fluid and inhibited the goblet cell hyperplasia. In this study, aerosolised honey was used to effectively treat and manage asthma in rabbits, and it could prove to be a promising treatment for asthma in humans. Future studies with a larger sample size and studies at the gene expression level are needed to better understand the mechanisms by which aerosolised honey reduces asthma symptoms.

Spatial pattern of receptor expression in the olfactory epithelium.

PubMed Central

Nef, P; Hermans-Borgmeyer, I; Artières-Pin, H; Beasley, L; Dionne, V E; Heinemann, S F

1992-01-01

A PCR-based strategy for amplifying putative receptors involved in murine olfaction was employed to isolate a member (OR3) of the seven-transmembrane-domain receptor superfamily. During development, the first cells that express OR3 appear adjacent to the wall of the telencephalic vesicle at embryonic day 10. The OR3 receptor is uniquely expressed in a subset of olfactory cells that have a characteristic bilateral symmetry in the adult olfactory epithelium. This receptor and its specific pattern of expression may serve a functional role in odor coding or, alternatively, may play a role in the development of the olfactory system. Images PMID:1384038

Loss of the Wnt receptor frizzled 7 in the mouse gastric epithelium is deleterious and triggers rapid repopulation in vivo

PubMed Central

2017-01-01

ABSTRACT The gastric epithelium consists of tubular glandular units, each containing several differentiated cell types, and populations of stem cells, which enable the stomach to secrete the acid, mucus and various digestive enzymes required for its function. Very little is known about which cell signalling pathways are required for homeostasis of the gastric epithelium. Many diseases, such as cancer, arise as a result of deregulation of signalling pathways that regulate homeostasis of the diseased organ. Therefore, it is important to understand the biology of how normal conditions are maintained in a tissue to help inform the mechanisms driving disease in that same tissue, and to identify potential points of therapeutic intervention. Wnt signalling regulates several cell functions, including proliferation, differentiation and migration, and plays a crucial role during homeostasis of several tissues, including the intestinal epithelium. Wnt3a is required in the culture medium of gastric organoids, suggesting it is also important for the homeostasis of the gastric epithelium, but this has not been investigated in vivo. Here, we show that the Wnt receptor frizzled 7 (Fzd7), which is required for the homeostasis of the intestine, is expressed in the gastric epithelium and is required for gastric organoid growth. Gastric-specific loss of Fzd7 in the adult gastric epithelium of mice is deleterious and triggers rapid epithelial repopulation, which we believe is the first observation of this novel function for this tissue. Taken together, these data provide functional evidence of a crucial role for Wnt signalling, via the Fzd7 receptor, during homeostasis of the gastric epithelium. PMID:28600348

Transport across the choroid plexus epithelium.

PubMed

Praetorius, Jeppe; Damkier, Helle Hasager

2017-06-01

The choroid plexus epithelium is a secretory epithelium par excellence. However, this is perhaps not the most prominent reason for the massive interest in this modest-sized tissue residing inside the brain ventricles. Most likely, the dominant reason for extensive studies of the choroid plexus is the identification of this epithelium as the source of the majority of intraventricular cerebrospinal fluid. This finding has direct relevance for studies of diseases and conditions with deranged central fluid volume or ionic balance. While the concept is supported by the vast majority of the literature, the implication of the choroid plexus in secretion of the cerebrospinal fluid was recently challenged once again. Three newer and promising areas of current choroid plexus-related investigations are as follows: 1 ) the choroid plexus epithelium as the source of mediators necessary for central nervous system development, 2 ) the choroid plexus as a route for microorganisms and immune cells into the central nervous system, and 3 ) the choroid plexus as a potential route for drug delivery into the central nervous system, bypassing the blood-brain barrier. Thus, the purpose of this review is to highlight current active areas of research in the choroid plexus physiology and a few matters of continuous controversy. Copyright © 2017 the American Physiological Society.

Alterations in vasodilator-stimulated phosphoprotein (VASP) phosphorylation: associations with asthmatic phenotype, airway inflammation and β2-agonist use

PubMed Central

Hastie, Annette T; Wu, Min; Foster, Gayle C; Hawkins, Gregory A; Batra, Vikas; Rybinski, Katherine A; Cirelli, Rosemary; Zangrilli, James G; Peters, Stephen P

2006-01-01

Background Vasodilator-stimulated phosphoprotein (VASP) mediates focal adhesion, actin filament binding and polymerization in a variety of cells, thereby inhibiting cell movement. Phosphorylation of VASP via cAMP and cGMP dependent protein kinases releases this "brake" on cell motility. Thus, phosphorylation of VASP may be necessary for epithelial cell repair of damage from allergen-induced inflammation. Two hypotheses were examined: (1) injury from segmental allergen challenge increases VASP phosphorylation in airway epithelium in asthmatic but not nonasthmatic normal subjects, (2) regular in vivo β2-agonist use increases VASP phosphorylation in asthmatic epithelium, altering cell adhesion. Methods Bronchial epithelium was obtained from asthmatic and non-asthmatic normal subjects before and after segmental allergen challenge, and after regularly inhaled albuterol, in three separate protocols. VASP phosphorylation was examined in Western blots of epithelial samples. DNA was obtained for β2-adrenergic receptor haplotype determination. Results Although VASP phosphorylation increased, it was not significantly greater after allergen challenge in asthmatics or normals. However, VASP phosphorylation in epithelium of nonasthmatic normal subjects was double that observed in asthmatic subjects, both at baseline and after challenge. Regularly inhaled albuterol significantly increased VASP phosphorylation in asthmatic subjects in both unchallenged and antigen challenged lung segment epithelium. There was also a significant increase in epithelial cells in the bronchoalveolar lavage of the unchallenged lung segment after regular inhalation of albuterol but not of placebo. The haplotypes of the β2-adrenergic receptor did not appear to associate with increased or decreased phosphorylation of VASP. Conclusion Decreased VASP phosphorylation was observed in epithelial cells of asthmatics compared to nonasthmatic normals, despite response to β-agonist. The decreased

Inhibition of TRPC3 downregulates airway hyperresponsiveness, remodeling of OVA-sensitized mouse.

PubMed

Wang, Lingwei; Li, Jie; Zhang, Jian; He, Qi; Weng, Xuanwen; Huang, Yanmei; Guan, Minjie; Qiu, Chen

2017-02-26

Airway hyperresponsiveness (AHR), airway remodeling and inflammation are the fundamental pathological alterations that occur in asthma. Transient receptor potential canonical 3 (TRPC3) has been implicated in diverse functions of airway smooth muscle cells (ASMCs) in asthma. However, the underlying mechanisms remain incompletely understood. We investigated the mRNA and protein expression of TRPC3 in ASMCs from normal and OVA-sensitized mouse. And the effects of inhibition or knockdown of TRPC3 with Ethyl-1- (4- (2,3,3-trichloroacrylamide) phenyl) -5 - (trifluoromethyl) -1H -pyrazole -4-carboxylate (Pyr3) and lentiviral shRNA on OVA-sensitized mouse AHR, airway remodeling, circulating inflammatory cytokines, cell proliferation and migration. We found that TRPC3 mRNA and protein expression levels were significantly increased in ASMCs from OVA-sensitized mouse. Inhibiting TRPC3 with continuous subcutaneous administration of Pyr3 decreased enhanced pause (Penh) of OVA-sensitized mouse. Meanwhile, both Pyr3 and lentiviral shRNA treatment of ASMCs in OVA-sensitized mouse significantly decreased their proliferation and migration. These results suggest that TRPC3 plays a critical role in asthma and represents a promising new target for asthma treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of upper airway in ventilatory control in awake and sleeping dogs.

PubMed

Stradling, J R; England, S J; Harding, R; Kozar, L F; Andrey, S; Phillipson, E A

1987-03-01

We examined the role of the upper airway in the regulation of the pattern of breathing in six adult dogs during wakefulness and sleep. The dogs breathed through a fenestrated endotracheal tube inserted through a tracheostomy. The tube was modified to allow airflow to be directed either through the nose or through the tracheostomy. When airflow was diverted from nose to tracheostomy there was an abrupt increase in the rate of expiratory airflow, resulting in prolongation of the end-expiratory pause but no change in overall expiratory duration or respiratory frequency. Furthermore, electromyogram recordings from implanted diaphragmatic and laryngeal muscle electrodes did not show any changes that could be interpreted as an attempt to delay expiratory airflow or increase end-expiratory lung volume. The effects of switching from nose to tracheostomy breathing could be reversed by adding a resistance to the endotracheal tube so as to approximate upper airway resistance. The findings indicate that under normal conditions in the adult dog upper airway receptors play little role in regulation of respiratory pattern and that the upper airway exerts little influence on the maintenance of end-expiratory lung volume.

Critical Airway Team: A Retrospective Study of an Airway Response System in a Pediatric Hospital.

PubMed

Sterrett, Emily C; Myer, Charles M; Oehler, Jennifer; Das, Bobby; Kerrey, Benjamin T

2017-12-01

Objective Study the performance of a pediatric critical airway response team. Study Design Case series with chart review. Setting Freestanding academic children's hospital. Subjects and Methods A structured review of the electronic medical record was conducted for all activations of the critical airway team. Characteristics of the activations and patients are reported using descriptive statistics. Activation of the critical airway team occurred 196 times in 46 months (March 2012 to December 2015); complete data were available for 162 activations (83%). For 49 activations (30%), patients had diagnoses associated with difficult intubation; 45 (28%) had a history of difficult laryngoscopy. Results Activation occurred at least 4 times per month on average (vs 3 per month for hospital-wide codes). The most common reasons for team activation were anticipated difficult intubation (45%) or failed intubation attempt (20%). For 79% of activations, the team performed an airway procedure, most commonly direct laryngoscopy and tracheal intubation. Bronchoscopy was performed in 47% of activations. Surgical airway rescue was attempted 4 times. Cardiopulmonary resuscitation occurred in 41 activations (25%). Twenty-nine patients died during or following team activation (18%), including 10 deaths associated with the critical airway event. Conclusion Critical airway team activation occurred at least once per week on average. Direct laryngoscopy, tracheal intubation, and bronchoscopic procedures were performed frequently; surgical airway rescue was rare. Most patients had existing risk factors for difficult intubation. Given our rate of serious morbidity and mortality, primary prevention of critical airway events will be a focus of future efforts.

A 4-Week Model of House Dust Mite (HDM) Induced Allergic Airways Inflammation with Airway Remodeling.

PubMed

Woo, L N; Guo, W Y; Wang, X; Young, A; Salehi, S; Hin, A; Zhang, Y; Scott, J A; Chow, C W

2018-05-02

Animal models of allergic airways inflammation are useful tools in studying the pathogenesis of asthma and potential therapeutic interventions. The different allergic airways inflammation models available to date employ varying doses, frequency, duration and types of allergen, which lead to the development of different features of asthma; showing varying degrees of airways inflammation and hyper-responsiveness (AHR) and airways remodeling. Models that also exhibit airway remodeling, a key feature of asthma, in addition to AHR and airway inflammation typically require 5-12 weeks to develop. In this report, we describe a 4-week mouse model of house dust mite (HDM)-induced allergic airways inflammation, and compare the phenotypic features of two different doses of HDM exposures (10 µg and 25 µg) for 5 days/week with a well-characterized 8-week chronic HDM model. We found that 4 weeks of intranasal HDM (25 µg in 35 µl saline; 5 days/week) resulted in AHR, airway inflammation and airway remodeling that were comparable to the 8-week model. We conclude that this new 4-week HDM model is another useful tool in studies of human asthma that offers advantages of shorter duration for development and decreased costs when compared to other models that require longer durations of exposure (5-12 weeks) to develop.

Effects of sodium metabisulphite on guinea pig contractile airway smooth muscle responses in vitro.

PubMed

Sun, J; Sakamoto, T; Chung, K F

1995-08-01

Sodium metabisulphite (MBS) is known to induce bronchoconstriction in asthmatic patients. The effects of MBS on guinea pig airway smooth muscle and on neurally mediated contraction in vitro have been examined. Tracheal and bronchial airway segments were placed in oxygenated buffer solution and electrical field stimulation was performed in the presence of indomethacin (10(-5) M) and propranolol (10(-6) M) for the measurement of isometric tension. Atropine (10(-6) M) was added to bronchial tissues. Concentrations of MBS up to 10(-3) M had no direct effect on airway smooth muscle contraction and did not alter either tracheal smooth muscle contraction induced by electrical field stimulation at all frequencies or acetylcholine-induced tracheal smooth muscle contraction. There was a similar response in the absence of epithelium, except for potentiation of the response induced by electrical field stimulation at 0.5 Hz (24 (10)% increase). However, MBS (10(-5), 10(-6) and 10(-7) M) augmented neurally-mediated non-adrenergic non-cholinergic contractile responses in the bronchi (13.3 (3.2)%, 23.8 (9.6)%, and 6.4 (1.6)%, respectively). MBS had no effect on the contractile response induced by substance P, but at higher concentrations (10(-3) M and 10(-4) M) it caused a time-dependent attenuation of responses induced by either electrical field stimulation or exogenously applied acetylcholine or substance P. MBS had no direct contractile responses but enhanced bronchoconstriction induced by activation of non-cholinergic neural pathways in the bronchus, probably through increased release of neuropeptides. At high concentrations MBS inhibited contractile responses initiated by receptor or neural stimulation.

Effects of sodium metabisulphite on guinea pig contractile airway smooth muscle responses in vitro.

PubMed Central

Sun, J.; Sakamoto, T.; Chung, K. F.

1995-01-01

BACKGROUND--Sodium metabisulphite (MBS) is known to induce bronchoconstriction in asthmatic patients. The effects of MBS on guinea pig airway smooth muscle and on neurally mediated contraction in vitro have been examined. METHODS--Tracheal and bronchial airway segments were placed in oxygenated buffer solution and electrical field stimulation was performed in the presence of indomethacin (10(-5) M) and propranolol (10(-6) M) for the measurement of isometric tension. Atropine (10(-6) M) was added to bronchial tissues. RESULTS--Concentrations of MBS up to 10(-3) M had no direct effect on airway smooth muscle contraction and did not alter either tracheal smooth muscle contraction induced by electrical field stimulation at all frequencies or acetylcholine-induced tracheal smooth muscle contraction. There was a similar response in the absence of epithelium, except for potentiation of the response induced by electrical field stimulation at 0.5 Hz (24 (10)% increase). However, MBS (10(-5), 10(-6) and 10(-7) M) augmented neurally-mediated non-adrenergic non-cholinergic contractile responses in the bronchi (13.3 (3.2)%, 23.8 (9.6)%, and 6.4 (1.6)%, respectively). MBS had no effect on the contractile response induced by substance P, but at higher concentrations (10(-3) M and 10(-4) M) it caused a time-dependent attenuation of responses induced by either electrical field stimulation or exogenously applied acetylcholine or substance P. CONCLUSIONS--MBS had no direct contractile responses but enhanced bronchoconstriction induced by activation of non-cholinergic neural pathways in the bronchus, probably through increased release of neuropeptides. At high concentrations MBS inhibited contractile responses initiated by receptor or neural stimulation. Images PMID:7570440

Purinergic P2Y receptors in airway epithelia: from ion transport to immune functions.

PubMed

Hao, Yuan; Ko, Wing-hung

2014-02-25

The regulated transport of salt and water is essential to the integrated function of many organ systems, including the respiratory, reproductive, and digestive tracts. Airway epithelial fluid secretion is a passive process that is driven by osmotic forces, which are generated by ion transport. The main determinant of a luminally-directed osmotic gradient is the mucosal transport of chloride ions (Cl(-)) into the lumen. As with many epithelial cells, a number of classic signal transduction cascades are involved in the regulation of ion transport. There are two well-known intracellular signaling systems: an increase in intracellular Ca(2+) concentration ([Ca(2+)]i) and an increase in the rate of synthesis of cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP). Therefore, Cl(-) secretion is primarily activated via the opening of apical Ca(2+)- or cAMP-dependent Cl(-) channels at the apical membrane. The opening of basolateral Ca(2+)- or cAMP-activated K(+) channels, which hyperpolarizes the cell to maintain the driving force for Cl(-) exit through apical Cl(-) channels that are constitutively open, is also important in regulating transepithelial ion transport. P2Y receptors are expressed in the apical and/or basolateral membranes of virtually all polarized epithelia to control the transport of fluid and electrolytes. Human airway epithelial cells express multiple nucleotide receptors. Extracellular nucleotides, such as UTP and ATP, are calcium-mobilizing secretagogues. They are released into the extracellular space from airway epithelial cells and act on the same cell in an autocrine fashion to stimulate transepithelial ion transport. In addition, recent data support the role of P2Y receptors in releasing inflammatory cytokines in the bronchial epithelium and other immune cells.

Phosphoinositide 3-kinase gamma regulates airway smooth muscle contraction by modulating calcium oscillations.

PubMed

Jiang, Haihong; Abel, Peter W; Toews, Myron L; Deng, Caishu; Casale, Thomas B; Xie, Yan; Tu, Yaping

2010-09-01

Phosphoinositide 3-kinase gamma (PI3Kgamma) has been implicated in the pathogenesis of asthma, but its mechanism has been considered indirect, through release of inflammatory cell mediators. Because airway smooth muscle (ASM) contractile hyper-responsiveness plays a critical role in asthma, the aim of the present study was to determine whether PI3Kgamma can directly regulate contractility of ASM. Immunohistochemistry staining indicated expression of PI3Kgamma protein in ASM cells of mouse trachea and lung, which was confirmed by Western blot analysis in isolated mouse tracheal ASM cells. PI3Kgamma inhibitor II inhibited acetylcholine (ACh)-stimulated airway contraction of cultured precision-cut mouse lung slices in a dose-dependent manner with 75% inhibition at 10 muM. In contrast, inhibitors of PI3Kalpha, PI3Kbeta, or PI3Kdelta, at concentrations 40-fold higher than their reported IC(50) values for their primary targets, had no effect. It is noteworthy that airways in lung slices pretreated with PI3Kgamma inhibitor II still exhibited an ACh-induced initial contraction, but the sustained contraction was significantly reduced. Furthermore, the PI3Kgamma-selective inhibitor had a small inhibitory effect on the ACh-stimulated initial Ca(2+) transient in ASM cells of mouse lung slices or isolated mouse ASM cells but significantly attenuated the sustained Ca(2+) oscillations that are critical for sustained airway contraction. This report is the first to show that PI3Kgamma directly controls contractility of airways through regulation of Ca(2+) oscillations in ASM cells. Thus, in addition to effects on airway inflammation, PI3Kgamma inhibitors may also exert direct effects on the airway contraction that contribute to pathologic airway hyper-responsiveness.

Phosphoinositide 3-Kinase γ Regulates Airway Smooth Muscle Contraction by Modulating Calcium Oscillations

PubMed Central

Jiang, Haihong; Abel, Peter W.; Toews, Myron L.; Deng, Caishu; Casale, Thomas B.; Xie, Yan

2010-01-01

Phosphoinositide 3-kinase γ (PI3Kγ) has been implicated in the pathogenesis of asthma, but its mechanism has been considered indirect, through release of inflammatory cell mediators. Because airway smooth muscle (ASM) contractile hyper-responsiveness plays a critical role in asthma, the aim of the present study was to determine whether PI3Kγ can directly regulate contractility of ASM. Immunohistochemistry staining indicated expression of PI3Kγ protein in ASM cells of mouse trachea and lung, which was confirmed by Western blot analysis in isolated mouse tracheal ASM cells. PI3Kγ inhibitor II inhibited acetylcholine (ACh)-stimulated airway contraction of cultured precision-cut mouse lung slices in a dose-dependent manner with 75% inhibition at 10 μM. In contrast, inhibitors of PI3Kα, PI3Kβ, or PI3Kδ, at concentrations 40-fold higher than their reported IC50 values for their primary targets, had no effect. It is noteworthy that airways in lung slices pretreated with PI3Kγ inhibitor II still exhibited an ACh-induced initial contraction, but the sustained contraction was significantly reduced. Furthermore, the PI3Kγ-selective inhibitor had a small inhibitory effect on the ACh-stimulated initial Ca2+ transient in ASM cells of mouse lung slices or isolated mouse ASM cells but significantly attenuated the sustained Ca2+ oscillations that are critical for sustained airway contraction. This report is the first to show that PI3Kγ directly controls contractility of airways through regulation of Ca2+ oscillations in ASM cells. Thus, in addition to effects on airway inflammation, PI3Kγ inhibitors may also exert direct effects on the airway contraction that contribute to pathologic airway hyper-responsiveness. PMID:20501633

In vivo effects of endotoxin on DNA synthesis in rat nasal epithelium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harkema, J.R.; Hotchkiss, J.A.

Airway inflammation in bacterial infections is characterized by the presence of neutrophils and often epithelial injury and repair. Release of endotoxin from bacteria may contribute to these processes. The purpose of this study was to determine the in vivo effects of repeated endotoxin exposure on DNA synthesis in rat nasal epithelium in the presence and absence of neutrophilic influx. Rats were intranasally instilled, once a day for 3 days, with endotoxin or saline (controls). Before the first and third instillations, half of the saline and endotoxin-instilled animals were depleted of circulating blood neutrophils by administering a rabbit anti-rat neutrophil antiserum.more » Rats were sacrificed 6 or 24 h after the last instillation. Two hours prior to sacrifice, rats were intraperitoneally injected with bromodeoxyuridine (BrdU), an analog of thymidine that is incorporated in the nucleus of cells in the S-phase of the cell cycle. Nasal tissues were processed for light microscopy and immunohistochemical detection of BrdU in nasal epithelial cells. The numbers of nasal epithelial cells, BrdU-labeled epithelial nuclei, and neutrophils per millimeter of basal lamina in the epithelium lining the nasal turbinates in the proximal nasal passages were determined by morphometric analysis. The authors did not observe a neutrophilic influx in the nasal tissues of neutrophil-depleted rats at 6 or 24 h after the last endotoxin instillation; however, the numbers of nasal epithelial cells and the BrdU-labeling index were significantly increased compared to saline-instilled controls. In contrast, non-neutrophil-depleted rats instilled with endotoxin had a marked neutrophilic influx, but no significant differences in the number of nasal epithelial cells at 6 or 24 h, compared to controls. In addition, the BrdU-labeling index in neutrophil-sufficient rats was increased only 6 h after the last instillation, compared to controls.« less

3D-modelling of radon-induced cellular radiobiological effects in bronchial airway bifurcations: direct versus bystander effects.

PubMed

Szőke, István; Farkas, Arpád; Balásházy, Imre; Hofmann, Werner; Madas, Balázs G; Szőke, Réka

2012-06-01

The primary objective of this paper was to investigate the distribution of radiation doses and the related biological responses in cells of a central airway bifurcation of the human lung of a hypothetical worker of the New Mexico uranium mines during approximately 12 hours of exposure to short-lived radon progenies. State-of-the-art computational modelling techniques were applied to simulate the relevant biophysical and biological processes in a central human airway bifurcation. The non-uniform deposition pattern of inhaled radon daughters caused a non-uniform distribution of energy deposition among cells, and of related cell inactivation and cell transformation probabilities. When damage propagation via bystander signalling was assessed, it produced more cell killing and cell transformation events than did direct effects. If bystander signalling was considered, variations of the average probabilities of cell killing and cell transformation were supra-linear over time. Our results are very sensitive to the radiobiological parameters, derived from in vitro experiments (e.g., range of bystander signalling), applied in this work and suggest that these parameters may not be directly applicable to realistic three-dimensional (3D) epithelium models.

In vivo μOCT imaging of the airways(Conference Presentation)

NASA Astrophysics Data System (ADS)

Leung, Hui Min; Yonker, Lael M.; Mou, Hongmei; Som, Avira; Hurley, Bryan P.; Tearney, Guillermo J.

2017-04-01

Chronic dysregulated influx of neutrophil into the airway increases neutrophil burden and augments the inflammatory processes often observed in diseases such as cystic fibrosis. The quantification of neutrophil influx is often accomplished with the use of destructive tests such as imaging cytometry and myeloperoxidase assay. However, those methods are unable to capture information about the cascade of events that precede trans-epithelium migration. In this work, we employed a high resolution micro-optical coherence tomography (µOCT) technology to perform real time imaging of neutrophil activity across airway epithelial cells grown on the underside of Transwell permeable supports. This inverted configuration allows the creation of an air-liquid interface at the apical side of the cells. The µOCT imaging technology, based on the principles of spectral-domain OCT, has a lateral and axial resolution of 2 and 1.3µm, respectively. In addition, it has an axial range of approximately 300µm and is capable of recording cross-sectional images at 40 fps. By raster scanning the illumination beam, the behavior of the neutrophils across a 3D volume can be recorded over time. Thus, this imaging modality is capable of resolving individual neutrophils and, potentially, capturing the cascading events involving neutrophil tethering, subsequent adhesion to activated epithelial cells and the ultimate passage through the epithelial cells to the air space on the apical side. As a result, not only can the amount of neutrophil migration be quantified, how neutrophils behave, organize and interact with the epithelial cells and each other can also be more closely analyzed by µOCT imaging.

Stromal loss of TGFβ drives cancer growth in the epithelium via inflammation | Center for Cancer Research

Cancer.gov

Interactions between epithelial and stromal cells play an important role in cancer development and progression. Epithelial cancers develop when changes occur to tumor suppressor genes in stromal fibroblast cells. For example, loss of tumor suppressor, p53, in stromal fibroblasts leads to p53 inactivation in the epithelium in a prostate cancer model, and disruption of the

Hair cell regeneration in the avian auditory epithelium.

PubMed

Stone, Jennifer S; Cotanche, Douglas A

2007-01-01

Regeneration of sensory hair cells in the mature avian inner ear was first described just over 20 years ago. Since then, it has been shown that many other non-mammalian species either continually produce new hair cells or regenerate them in response to trauma. However, mammals exhibit limited hair cell regeneration, particularly in the auditory epithelium. In birds and other non-mammals, regenerated hair cells arise from adjacent non-sensory (supporting) cells. Hair cell regeneration was initially described as a proliferative response whereby supporting cells re-enter the mitotic cycle, forming daughter cells that differentiate into either hair cells or supporting cells and thereby restore cytoarchitecture and function in the sensory epithelium. However, further analyses of the avian auditory epithelium (and amphibian vestibular epithelium) revealed a second regenerative mechanism, direct transdifferentiation, during which supporting cells change their gene expression and convert into hair cells without dividing. In the chicken auditory epithelium, these two distinct mechanisms show unique spatial and temporal patterns, suggesting they are differentially regulated. Current efforts are aimed at identifying signals that maintain supporting cells in a quiescent state or direct them to undergo direct transdifferentiation or cell division. Here, we review current knowledge about supporting cell properties and discuss candidate signaling molecules for regulating supporting cell behavior, in quiescence and after damage. While significant advances have been made in understanding regeneration in non-mammals over the last 20 years, we have yet to determine why the mammalian auditory epithelium lacks the ability to regenerate hair cells spontaneously and whether it is even capable of significant regeneration under additional circumstances. The continued study of mechanisms controlling regeneration in the avian auditory epithelium may lead to strategies for inducing

Impairment of vascularization of the surface covering epithelium induces ischemia and promotes malignization: a new hypothesis of a possible mechanism of cancer pathogenesis.

PubMed

Karseladze, A I

2015-06-01

To study the peculiarities of vascularization at the stromal-epithelial interface in different types of epithelia and their alterations in precancerous lesions. Peritumoral tissues of 310 patients, tissues of 180 healthy persons and of 50 human embryos and fetuses were used. Traditional histological as well as immunohistochemical methods have been used. The study reveals that the occurrence of blood capillaries in surface squamous epithelium is an ordinary event, both in healthy persons and in peritumoral regions of the patients with squamous cell carcinoma. Glandular epithelial coverings, as well as transitional epithelium, do not contain blood vessels. In squamous epithelium, only basal cells are in contact with the membrane and underlying stroma, the cells of the upper layer receiving nutrients through diffusion. Thus, the cells of squamous epithelium are more vulnerable to blood deficiency, since for instance in the pseudo-multilayered respiratory epithelium each cell is attached directly to the basal membrane and has more ample access to the blood supply. Metaplastic squamous epithelium has a markedly reduced vascularization and seems to be more sensitive to carcinogenic stimuli. High-grade dysplastic squamous epithelium and carcinoma in situ do not contain blood vessels. The process of redistribution of vascular network occurring at the interface of epithelial-stromal frontier plays an important role in maintaining the adequate metabolism of cells including those of epithelial covering. Impairment of this mechanism most probably promotes precancerous alterations.

G protein-coupled estrogen receptor inhibits the P2Y receptor-mediated Ca(2+) signaling pathway in human airway epithelia.

PubMed

Hao, Yuan; Chow, Alison W; Yip, Wallace C; Li, Chi H; Wan, Tai F; Tong, Benjamin C; Cheung, King H; Chan, Wood Y; Chen, Yangchao; Cheng, Christopher H; Ko, Wing H

2016-08-01

P2Y receptor activation causes the release of inflammatory cytokines in the bronchial epithelium, whereas G protein-coupled estrogen receptor (GPER), a novel estrogen (E2) receptor, may play an anti-inflammatory role in this process. We investigated the cellular mechanisms underlying the inhibitory effect of GPER activation on the P2Y receptor-mediated Ca(2+) signaling pathway and cytokine production in airway epithelia. Expression of GPER in primary human bronchial epithelial (HBE) or 16HBE14o- cells was confirmed on both the mRNA and protein levels. Stimulation of HBE or 16HBE14o- cells with E2 or G1, a specific agonist of GPER, attenuated the nucleotide-evoked increases in [Ca(2+)]i, whereas this effect was reversed by G15, a GPER-specific antagonist. G1 inhibited the secretion of two proinflammatory cytokines, interleukin (IL)-6 and IL-8, in cells stimulated by adenosine 5'-(γ-thio)triphosphate (ATPγS). G1 stimulated a real-time increase in cAMP levels in 16HBE14o- cells, which could be inhibited by adenylyl cyclase inhibitors. The inhibitory effects of E2 or G1 on P2Y receptor-induced increases in Ca(2+) were reversed by treating the cells with a protein kinase A (PKA) inhibitor. These results demonstrated that the inhibitory effects of G1 or E2 on P2Y receptor-mediated Ca(2+) mobilization and cytokine secretion were due to GPER-mediated activation of a cAMP-dependent PKA pathway. This study has reported, for the first time, the expression and function of GPER as an anti-inflammatory component in human bronchial epithelia, which may mediate through its opposing effects on the pro-inflammatory pathway activated by the P2Y receptors in inflamed airway epithelia.

Ferret airway epithelial cell cultures support efficient replication of influenza B virus but not mumps virus.

PubMed

Elderfield, Ruth A; Parker, Lauren; Stilwell, Peter; Roberts, Kim L; Schepelmann, Silke; Barclay, Wendy S

2015-08-01

Ferrets have become the model animal of choice for influenza pathology and transmission experiments as they are permissive and susceptible to human influenza A viruses. However, inoculation of ferrets with mumps virus (MuV) did not lead to successful infections. We evaluated the use of highly differentiated ferret tracheal epithelium cell cultures, FTE, for predicting the potential of ferrets to support respiratory viral infections. FTE cultures supported productive replication of human influenza A and B viruses but not of MuV, whereas analogous cells generated from human airways supported replication of all three viruses. We propose that in vitro strategies using these cultures might serve as a method of triaging viruses and potentially reducing the use of ferrets in viral studies.

Yki/YAP, Sd/TEAD and Hth/MEIS Control Tissue Specification in the Drosophila Eye Disc Epithelium

PubMed Central

Pignoni, Francesca

2011-01-01

During animal development, accurate control of tissue specification and growth are critical to generate organisms of reproducible shape and size. The eye-antennal disc epithelium of Drosophila is a powerful model system to identify the signaling pathway and transcription factors that mediate and coordinate these processes. We show here that the Yorkie (Yki) pathway plays a major role in tissue specification within the developing fly eye disc epithelium at a time when organ primordia and regional identity domains are specified. RNAi-mediated inactivation of Yki, or its partner Scalloped (Sd), or increased activity of the upstream negative regulators of Yki cause a dramatic reorganization of the eye disc fate map leading to specification of the entire disc epithelium into retina. On the contrary, constitutive expression of Yki suppresses eye formation in a Sd-dependent fashion. We also show that knockdown of the transcription factor Homothorax (Hth), known to partner Yki in some developmental contexts, also induces an ectopic retina domain, that Yki and Scalloped regulate Hth expression, and that the gain-of-function activity of Yki is partially dependent on Hth. Our results support a critical role for Yki- and its partners Sd and Hth - in shaping the fate map of the eye epithelium independently of its universal role as a regulator of proliferation and survival. PMID:21811580

Objectivity in the classification of tumours of the nasal epithelium

PubMed Central

Michaels, L.; Hyams, V. J.

1975-01-01

A survey of tumours derived from each of the four cell types of nasal epithelium is presented. Criticism is levelled at the adoption of additional terms for tissue types such as lympho-epithelium and transitional cell epithelium and tumours said to be derived from them. Electron microscopy is of assistance in classification particularly in the detection of evidence of keratin synthesis. The proposed classification of tumours of the nasal epithelium is: (1) Pseudostratified columnar epithelium: (a) papillary adenoma, (b) papillary carcinoma. (2) Squamous epithelium: (a) everted squamous papilloma, (b) inverted papilloma, (c) squamous carcinoma of any grade of differentiation from well differentiated to undifferentiated. (3) Melanocyte: malignant melanoma. (4) Olfactory neuroepithelium: olfactory neuroblastoma. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13Fig. 14Fig. 15Fig. 16Fig. 17Fig. 18Fig. 19Fig. 21Fig. 20 PMID:1197175

Developmental origin of the posterior pigmented epithelium of iris.

PubMed

Wang, Xiaobing; Xiong, Kai; Lu, Lei; Gu, Dandan; Wang, Songtao; Chen, Jing; Xiao, Honglei; Zhou, Guomin

2015-03-01

Iris epithelium is a double-layered pigmented cuboidal epithelium. According to the current model, the neural retina and the posterior iris pigment epithelium (IPE) are derived from the inner wall of the optic cup, while the retinal pigment epithelium (RPE) and the anterior IPE are derived from the outer wall of the optic cup during development. Our current study shows evidence, contradicting this model of fetal iris development. We demonstrate that human fetal iris expression patterns of Otx2 and Mitf transcription factors are similar, while the expressions of Otx2 and Sox2 are complementary. Furthermore, IPE and RPE exhibit identical morphologic development during the early embryonic period. Our results suggest that the outer layer of the optic cup forms two layers of the iris epithelium, and the posterior IPE is the inward-curling anterior rim of the outer layer of the optic cup. These findings provide a reasonable explanation of how IPE cells can be used as an appropriate substitute for RPE cells.

Follistatin-like 1 expression is decreased in the alveolar epithelium of hypoplastic rat lungs with nitrofen-induced congenital diaphragmatic hernia.

PubMed

Takahashi, Toshiaki; Zimmer, Julia; Friedmacher, Florian; Puri, Prem

2017-05-01

Pulmonary hypoplasia (PH), characterized by incomplete alveolar development, remains a major therapeutic challenge associated with congenital diaphragmatic hernia (CDH). Follistatin-like 1 (Fstl1) is a crucial regulator of alveolar formation and maturation, which is strongly expressed in distal airway epithelium. Fstl1-deficient mice exhibit reduced airspaces, impaired alveolar epithelial cell differentiation, and insufficient production of surfactant proteins similar to PH in human CDH. We hypothesized that pulmonary Fstl1 expression is decreased during alveolarization in the nitrofen-induced CDH model. Timed-pregnant rats received nitrofen or vehicle on gestational day 9 (D9). Fetal lungs were harvested on D18 and D21 and divided into control-/nitrofen-exposed specimens. Alveolarization was assessed using morphometric analysis techniques. Pulmonary gene expression of Fstl1 was determined by qRT-PCR. Immunofluorescence-double-staining for Fstl1 and alveolar epithelial marker surfactant protein C (SP-C) was performed to evaluate protein expression/localization. Radial alveolar count was significantly reduced in hypoplastic lungs of nitrofen-exposed fetuses with significant down regulation of Fstl1 mRNA expression on D18 and D21 compared to controls. Confocal-laser-scanning-microscopy revealed strikingly diminished Fstl1 immunofluorescence and SP-C expression in distal alveolar epithelium of nitrofen-exposed fetuses with CDH-associated PH on D18 and D21 compared to controls. Decreased expression of Fstl1 in alveolar epithelium may disrupt alveolarization and pulmonary surfactant production, thus contributing to the development of PH in the nitrofen-induced CDH model. 2b (Centre for Evidence-Based Medicine, Oxford). Copyright © 2017 Elsevier Inc. All rights reserved.

Physical principle of airway design in human lungs

NASA Astrophysics Data System (ADS)

Park, Keunhwan; Son, Taeho; Kim, Wonjung; Kim, Ho-Young

2014-11-01

From an engineering perspective, lungs are natural microfluidic devices that extract oxygen from air. In the bronchial tree, airways branch by dichotomy with a systematic reduction of their diameters. It is generally accepted that in conducting airways, which air passes on the way to the acinar airways from the atmosphere, the reduction ratio of diameter is closely related to the minimization of viscous dissipation. Such a principle is formulated as the Hess-Murray law. However, in acinar airways, where oxygen transfer to alveolae occurs, the diameter reduction with progressive generations is more moderate than in conducting airways. Noting that the dominant transfer mechanism in acinar airways is diffusion rather than advection, unlike conducting airways, we construct a mathematical model for oxygen transfer through a series of acinar airways. Our model allows us to predict the optimal airway reduction ratio that maximizes the oxygen transfer in a finite airway volume, thereby rationalizing the observed airway reduction ratio in acinar airways.

Airway management in cervical spine injury

PubMed Central

Austin, Naola; Krishnamoorthy, Vijay; Dagal, Arman

2014-01-01

To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury. PMID:24741498

Relationships between equine airway reactivity measured by flowmetric plethysmography and specific indicators of airway inflammation in horses with suspected inflammatory airway disease.

PubMed

Wichtel, M; Gomez, D; Burton, S; Wichtel, J; Hoffman, A

2016-07-01

Agreement between airway reactivity measured by flowmetric plethysmography and histamine bronchoprovocation, and lower airway inflammation measured by bronchoalveolar lavage (BAL) cytology, has not been studied in horses with suspected inflammatory airway disease (IAD). We tested the hypothesis that airway reactivity is associated with BAL cytology in horses presenting for unexplained poor performance and/or chronic cough. Prospective clinical study. Forty-five horses, predominantly young Standardbred racehorses, presenting for unexplained poor performance or chronic cough, underwent endoscopic evaluation, tracheal wash, flowmetric plethysmography with histamine bronchoprovocation and BAL. Histamine response was measured by calculating PC35, the concentration of nebulised histamine eliciting an increase in Δflow of 35%. In this population, there was no significant correlation between histamine response and cell populations in BAL cytology. When airway hyperreactivity (AHR) was defined as ≥35% increase in Δflow at a histamine concentration of <6 mg/ml, 24 of the 45 horses (53%) were determined to have AHR. Thirty-three (73%) had either abnormal BAL cytology or AHR, and were diagnosed with IAD on this basis. Of horses diagnosed with IAD, 9 (27%) had an abnormal BAL, 11 (33%) had AHR and 13 (39%) had both. Airway reactivity and BAL cytology did not show concordance in this population of horses presenting for unexplained poor performance and/or chronic cough. Failure to include tests of airway reactivity may lead to underdiagnosis of IAD in young Standardbred racehorses that present with clinical signs suggestive of IAD. © 2015 EVJ Ltd.

Anatomic Optical Coherence Tomography of Upper Airways

NASA Astrophysics Data System (ADS)

Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

Radiology-guided forceps biopsy and airway stenting in severe airway stenosis.

PubMed

Li, Zong Ming; Wu, Gang; Han, Xin Wei; Ren, Ke Wei; Zhu, Ming

2014-01-01

We aimed to determine the feasibility, safety, and effectiveness of radiology-guided forceps biopsy and airway stenting in patients with severe airway stenosis. This study involved 28 patients with severe airway stenosis who underwent forceps biopsy between October 2006 and September 2011. Chest multislice computed tomography was used to determine the location and extent of stenosis. Sixteen patients had tracheal stenosis, two patients had stenosis of the tracheal carina, six patients had stenosis of the left main bronchus, and four patients had stenosis of the right main bronchus. Forceps biopsy and stenting of the stenosed area were performed under fluoroscopic guidance in digital subtraction angiography and the biopsy specimens were analyzed histopathologically. We contacted the patients via phone call and utilized a standardized questionnaire to determine their medical condition during a postoperative three-month follow-up. The technical success rate of radiology-guided forceps biopsy was 100%. Biopsy specimens were obtained in all patients. Dyspnea was relieved immediately after stent placement. No serious complications, such as tracheal hemorrhage or perforation, mediastinal emphysema, or asphyxia, occurred. Radiology-guided forceps biopsy and airway stenting can be used for the emergency treatment of severe airway stenosis. This method appears to be safe and effective, and it may be an alternative therapeutic option in patients who cannot tolerate fiberoptic bronchoscopy.

Radiology-guided forceps biopsy and airway stenting in severe airway stenosis

PubMed Central

Li, Zong-Ming; Wu, Gang; Han, Xin-Wei; Ren, Ke-Wei; Zhu, Ming

2014-01-01

PURPOSE We aimed to determine the feasibility, safety, and effectiveness of radiology-guided forceps biopsy and airway stenting in patients with severe airway stenosis. MATERIALS AND METHODS This study involved 28 patients with severe airway stenosis who underwent forceps biopsy between October 2006 and September 2011. Chest multislice computed tomography was used to determine the location and extent of stenosis. Sixteen patients had tracheal stenosis, two patients had stenosis of the tracheal carina, six patients had stenosis of the left main bronchus, and four patients had stenosis of the right main bronchus. Forceps biopsy and stenting of the stenosed area were performed under fluoroscopic guidance in digital subtraction angiography and the biopsy specimens were analyzed histopathologically. We contacted the patients via phone call and utilized a standardized questionnaire to determine their medical condition during a postoperative three-month follow-up. RESULTS The technical success rate of radiology-guided forceps biopsy was 100%. Biopsy specimens were obtained in all patients. Dyspnea was relieved immediately after stent placement. No serious complications, such as tracheal hemorrhage or perforation, mediastinal emphysema, or asphyxia, occurred. CONCLUSION Radiology-guided forceps biopsy and airway stenting can be used for the emergency treatment of severe airway stenosis. This method appears to be safe and effective, and it may be an alternative therapeutic option in patients who cannot tolerate fiberoptic bronchoscopy. PMID:24808434

20-HETE mediates ozone-induced, neutrophil-independent airway hyper-responsiveness in mice.

PubMed

Cooper, Philip R; Mesaros, A Clementina; Zhang, Jie; Christmas, Peter; Stark, Christopher M; Douaidy, Karim; Mittelman, Michael A; Soberman, Roy J; Blair, Ian A; Panettieri, Reynold A

2010-04-20

Ozone, a pollutant known to induce airway hyper-responsiveness (AHR), increases morbidity and mortality in patients with obstructive airway diseases and asthma. We postulate oxidized lipids mediate in vivo ozone-induced AHR in murine airways. Male BALB/c mice were exposed to ozone (3 or 6 ppm) or filtered air (controls) for 2 h. Precision cut lung slices (PCLS; 250 microm thickness) containing an intrapulmonary airway ( approximately 0.01 mm(2) lumen area) were prepared immediately after exposure or 16 h later. After 24 h, airways were contracted to carbachol (CCh). Log EC(50) and E(max) values were then calculated by measuring the airway lumen area with respect to baseline. In parallel studies, dexamethasone (2.5 mg/kg), or 1-aminobenzotriazol (ABT) (50 mg/kg) were given intraperitoneal injection to naïve mice 18 h prior to ozone exposure. Indomethacin (10 mg/kg) was administered 2 h prior. Cell counts, cytokine levels and liquid chromatography-mass spectrometry (LC-MS) for lipid analysis were assessed in bronchoalveolar lavage (BAL) fluid from ozone exposed and control mice. Ozone acutely induced AHR to CCh. Dexamethasone or indomethacin had little effect on the ozone-induced AHR; while, ABT, a cytochrome P450 inhibitor, markedly attenuated airway sensitivity. BAL fluid from ozone exposed animals, which did not contain an increase in neutrophils or interleukin (IL)-6 levels, increased airway sensitivity following in vitro incubation with a naïve PCLS. In parallel, significant increases in oxidized lipids were also identified using LC-MS with increases of 20-HETE that were decreased following ABT treatment. These data show that ozone acutely induces AHR to CCh independent of inflammation and is insensitive to steroid treatment or cyclooxygenase (COX) inhibition. BAL fluid from ozone exposed mice mimicked the effects of in vivo ozone exposure that were associated with marked increases in oxidized lipids. 20-HETE plays a pivotal role in mediating acute ozone

Satratoxin-G from the black mold Stachybotrys chartarum induces rhinitis and apoptosis of olfactory sensory neurons in the nasal airways of rhesus monkeys.

PubMed

Carey, Stephan A; Plopper, Charles G; Hyde, Dallas M; Islam, Zahidul; Pestka, James J; Harkema, Jack R

2012-08-01

Satratoxin-G (SG) is a trichothecene mycotoxin of Stachybotrys chartarum, the black mold suggested to contribute etiologically to illnesses associated with water-damaged buildings. We have reported that intranasal exposure to SG evokes apoptosis of olfactory sensory neurons (OSNs) and acute inflammation in the nose and brain of laboratory mice. To further assess the potential human risk of nasal airway injury and neurotoxicity, we developed a model of SG exposure in monkeys, whose nasal airways more closely resemble those of humans. Adult, male rhesus macaques received a single intranasal instillation of 20 µg SG (high dose, n = 3), or 5 µg SG daily for four days (repeated low dose, n = 3) in one nasal passage, and saline vehicle in the contralateral nasal passage. Nasal tissues were examined using light and electron microscopy and morphometric analysis. SG induced acute rhinitis, atrophy of the olfactory epithelium (OE), and apoptosis of OSNs in both groups. High-dose and repeated low-dose SG elicited a 13% and 66% reduction in OSN volume density, and a 14-fold and 24-fold increase in apoptotic cells of the OE, respectively. This model provides new insight into the potential risk of nasal airway injury and neurotoxicity caused by exposure to water-damaged buildings.

Comparative Study of Influenza Virus Replication in MDCK Cells and in Primary Cells Derived from Adenoids and Airway Epithelium

PubMed Central

Ikizler, Mine R.; Kawaoka, Yoshihiro; Rudenko, Larisa G.; Treanor, John J.; Subbarao, Kanta; Wright, Peter F.

2012-01-01

Although clinical trials with human subjects are essential for determination of safety, infectivity, and immunogenicity, it is desirable to know in advance the infectiousness of potential candidate live attenuated influenza vaccine strains for human use. We compared the replication kinetics of wild-type and live attenuated influenza viruses, including H1N1, H3N2, H9N2, and B strains, in Madin-Darby canine kidney (MDCK) cells, primary epithelial cells derived from human adenoids, and human bronchial epithelium (NHBE cells). Our data showed that despite the fact that all tissue culture models lack a functional adaptive immune system, differentiated cultures of human epithelium exhibited the greatest restriction for all H1N1, H3N2, and B vaccine viruses studied among three cell types tested and the best correlation with their levels of attenuation seen in clinical trials with humans. In contrast, the data obtained with MDCK cells were the least predictive of restricted viral replication of live attenuated vaccine viruses in humans. We were able to detect a statistically significant difference between the replication abilities of the U.S. (A/Ann Arbor/6/60) and Russian (A/Leningrad/134/17/57) cold-adapted vaccine donor strains in NHBE cultures. Since live attenuated pandemic influenza vaccines may potentially express a hemagglutinin and neuraminidase from a non-human influenza virus, we assessed which of the three cell cultures could be used to optimally evaluate the infectivity and cellular tropism of viruses derived from different hosts. Among the three cell types tested, NHBE cultures most adequately reflected the infectivity and cellular tropism of influenza virus strains with different receptor specificities. NHBE cultures could be considered for use as a screening step for evaluating the restricted replication of influenza vaccine candidates. PMID:22915797

Epithelium percentage estimation facilitates epithelial quantitative protein measurement in tissue specimens.

PubMed

Chen, Jing; Toghi Eshghi, Shadi; Bova, George Steven; Li, Qing Kay; Li, Xingde; Zhang, Hui

2013-12-01

The rapid advancement of high-throughput tools for quantitative measurement of proteins has demonstrated the potential for the identification of proteins associated with cancer. However, the quantitative results on cancer tissue specimens are usually confounded by tissue heterogeneity, e.g. regions with cancer usually have significantly higher epithelium content yet lower stromal content. It is therefore necessary to develop a tool to facilitate the interpretation of the results of protein measurements in tissue specimens. Epithelial cell adhesion molecule (EpCAM) and cathepsin L (CTSL) are two epithelial proteins whose expressions in normal and tumorous prostate tissues were confirmed by measuring staining intensity with immunohistochemical staining (IHC). The expressions of these proteins were measured by ELISA in protein extracts from OCT embedded frozen prostate tissues. To eliminate the influence of tissue heterogeneity on epithelial protein quantification measured by ELISA, a color-based segmentation method was developed in-house for estimation of epithelium content using H&E histology slides from the same prostate tissues and the estimated epithelium percentage was used to normalize the ELISA results. The epithelium contents of the same slides were also estimated by a pathologist and used to normalize the ELISA results. The computer based results were compared with the pathologist's reading. We found that both EpCAM and CTSL levels, measured by ELISA assays itself, were greatly affected by epithelium content in the tissue specimens. Without adjusting for epithelium percentage, both EpCAM and CTSL levels appeared significantly higher in tumor tissues than normal tissues with a p value less than 0.001. However, after normalization by the epithelium percentage, ELISA measurements of both EpCAM and CTSL were in agreement with IHC staining results, showing a significant increase only in EpCAM with no difference in CTSL expression in cancer tissues. These results

Endocrine cells in ectocervical epithelium. An immunohistochemical and ultrastructural analysis.

PubMed

Fetissof, F; Arbeille, B; Boivin, F; Sam-Giao, M; Henrion, C; Lansac, J

1987-01-01

A systematic study of endocrine cells in the ectocervix was carried out using histochemical, immunohistochemical and ultrastructural techniques. Serotonin and calcitonin immunoreactive cells were demonstrated in this site. Serotonin and calcitonin immunoreactivities were coexpressed in the same endocrine cell. These distinctive cells were encountered in two main morphological varieties of ectocervical epithelium. Normal-appearing stratified squamous epithelium contained only very rare serotonin and calcitonin cells. In contrast, endocrine cells were fairly abundant in a specific epithelium termed "transitional-like". This type of epithelium was not only confined to the transformation zone but could also extend onto the portio as far as the vaginal cut margin. In some cases, transitional-like epithelium bore morphological resemblance to urothelium. In other cases, it could be regarded as basal cell hyperplasia or immature squamous metaplasia. Of interest, serotonin and calcitonin cells have been well-documented as normal inhabitants of some other non-squamous epithelia, such as urothelium or pseudostratified columnar epithelium. Therefore, it is suggested that certain ectocervical epithelia show some similarities to urothelium, in respect of their morphological appearance and endocrine profile. Further investigations using more objective and specific markers of urothelial cells are needed to assess the exact degree of homology connecting all these types of epithelium.

Investigation of mucus transport in an idealized lung airway model using multiphase CFD analysis

NASA Astrophysics Data System (ADS)

Rajendran, Rahul; Banerjee, Arindam

2015-11-01

Mucus, a Bingham fluid is transported in the pulmonary airways by consistent beating of the cilia and exhibits a wide range of physical properties in response to the core air flow and various pathological conditions. A better understanding of the interfacial instability is required as it plays a crucial role in gas transport, mixing, mucus clearance and drug delivery. In the current study, mucus is modelled as a Newtonian fluid and the two phase gas-liquid flow in the airways is investigated using an inhomogeneous Eulerian-Eulerian approach. The complex interface between the phases is tracked using the conventional VOF (Volume of Fluid) method. Results from our CFD simulations which are performed in idealized single and double bifurcation geometries will be presented and the influence of airflow rate, mucus layer thickness, mucus viscosity, airway geometry (branching & diameter) and surface tension on mucus flow behavior will be discussed. Mean mucus layer thickness, pressure drop due to momentum transfer & increased airway resistance, mucus transport speed and the flow morphology will be compared to existing experimental and theoretical data.

Loss of the Wnt receptor frizzled 7 in the mouse gastric epithelium is deleterious and triggers rapid repopulation in vivo.

PubMed

Flanagan, Dustin J; Barker, Nick; Nowell, Cameron; Clevers, Hans; Ernst, Matthias; Phesse, Toby J; Vincan, Elizabeth

2017-08-01

The gastric epithelium consists of tubular glandular units, each containing several differentiated cell types, and populations of stem cells, which enable the stomach to secrete the acid, mucus and various digestive enzymes required for its function. Very little is known about which cell signalling pathways are required for homeostasis of the gastric epithelium. Many diseases, such as cancer, arise as a result of deregulation of signalling pathways that regulate homeostasis of the diseased organ. Therefore, it is important to understand the biology of how normal conditions are maintained in a tissue to help inform the mechanisms driving disease in that same tissue, and to identify potential points of therapeutic intervention. Wnt signalling regulates several cell functions, including proliferation, differentiation and migration, and plays a crucial role during homeostasis of several tissues, including the intestinal epithelium. Wnt3a is required in the culture medium of gastric organoids, suggesting it is also important for the homeostasis of the gastric epithelium, but this has not been investigated in vivo Here, we show that the Wnt receptor frizzled 7 (Fzd7), which is required for the homeostasis of the intestine, is expressed in the gastric epithelium and is required for gastric organoid growth. Gastric-specific loss of Fzd7 in the adult gastric epithelium of mice is deleterious and triggers rapid epithelial repopulation, which we believe is the first observation of this novel function for this tissue. Taken together, these data provide functional evidence of a crucial role for Wnt signalling, via the Fzd7 receptor, during homeostasis of the gastric epithelium. © 2017. Published by The Company of Biologists Ltd.

Morphological studies of the developing human esophageal epithelium.

PubMed

Ménard, D

1995-06-15

This article focusses on the structural development of human esophageal ciliated epithelium. A combination of transmission electron microscopic (TEM), scanning electron microscopic (SEM), radioautographic, and light microscopic (LM) analyses were carried out using intact fetal tissues between 8 and 20 weeks of gestation as well as cultured esophageal explants. Up to the age of 10 weeks, the stratified esophageal epithelium consisted of two longitudinal primary folds. The surface cells were undifferentiated and contained large glycogen aggregates. Between 11 and 16 weeks, the primary folds (now up to four) had developed secondary folds. The thickness of the epithelium drastically increased (123%) in concomittance with a differentiation of surface columnar ciliated cells. These highly specialized surface cells exhibited junctional complexes and well-developed organelles with numerous microvilli interspersed among the cilia. Transverse sections revealed the internal structure of the cilia with a consistent pattern of nine doublet microtubules surrounding a central pair of single microtubules. Freeze-fracture studies illustrated the presence of a ciliary necklace composed of 6 ring-like rows of intramembranous particles. They also revealed the structure of ciliary cell tight junctions consisting of up to nine anastomosing strands (P-face) or complementary grooves (E-face). Ultrastructural studies (LM, TEM, SEM) of the esophageal squamous epithelium obtained after 15 days of culture showed that the newly formed epithelium was similar to adult human epithelium. Finally LM and SEM observations established that the esophagogastric junction was not yet well delineated, consisting of a transitional area composed of a mixture of esophageal ciliated cells and gastric columnar mucous cells.

Inflammatory bowel disease and airway diseases.

PubMed

Vutcovici, Maria; Brassard, Paul; Bitton, Alain

2016-09-14

Airway diseases are the most commonly described lung manifestations of inflammatory bowel disease (IBD). However, the similarities in disease pathogenesis and the sharing of important environmental risk factors and genetic susceptibility suggest that there is a complex interplay between IBD and airway diseases. Recent evidence of IBD occurrence among patients with airway diseases and the higher than estimated prevalence of subclinical airway injuries among IBD patients support the hypothesis of a two-way association. Future research efforts should be directed toward further exploration of this association, as airway diseases are highly prevalent conditions with a substantial public health impact.

The active contribution of Toll-like receptors to allergic airway inflammation.

PubMed

Chen, Keqiang; Xiang, Yi; Yao, Xiaohong; Liu, Ying; Gong, Wanghua; Yoshimura, Teizo; Wang, Ji Ming

2011-10-01

Epithelia lining the respiratory tract represent a major portal of entry for microorganisms and allergens and are equipped with innate and adaptive immune signaling receptors for host protection. These include Toll-like receptors (TLRs) that recognize microbial components and evoke diverse responses in cells of the respiratory system. TLR stimulation by microorganism-derived molecules activates antigen presenting cells, control T helper (Th) 1, Th2, and Th17 immune cell differentiation, cytokine production by mast cells, and activation of eosinophils. It is clear that TLR are involved in the pathophysiology of allergic airway diseases such as asthma. Dendritic cells (DCs), a kind of antigen presenting cells, which play a key role in the induction of allergic airway inflammation, are privileged targets for pathogen associated molecular patterns (PAMPs). During the allergic responses, engagement of TLRs on DCs determines the Th2 polarization of the T cells. TLR signaling in mast cells increases the release of IL-5, and TLR activation of airway epithelial cells forces the generation of proallergic Th2 type of cytokines. Although these responses aim to protect the host, they may also result in inflammatory tissue damage in the airway. Under certain conditions, stimulation of TLRs, in particular, TLR9, may reduce Th2-dependent allergic inflammation by induction of Th1 responses. Therefore, understanding the complex regulatory roles of TLRs in the pathogenesis of allergic airway inflammation should facilitate the development of preventive and therapeutic measures for asthmatic patients. Copyright © 2011 Elsevier B.V. All rights reserved.

Microbiota promote secretory cell determination in the intestinal epithelium by modulating host Notch signaling.

PubMed

Troll, Joshua V; Hamilton, M Kristina; Abel, Melissa L; Ganz, Julia; Bates, Jennifer M; Stephens, W Zac; Melancon, Ellie; van der Vaart, Michiel; Meijer, Annemarie H; Distel, Martin; Eisen, Judith S; Guillemin, Karen

2018-02-23

Resident microbes promote many aspects of host development, although the mechanisms by which microbiota influence host tissues remain unclear. We showed previously that the microbiota is required for allocation of appropriate numbers of secretory cells in the zebrafish intestinal epithelium. Because Notch signaling is crucial for secretory fate determination, we conducted epistasis experiments to establish whether the microbiota modulates host Notch signaling. We also investigated whether innate immune signaling transduces microbiota cues via the Myd88 adaptor protein. We provide the first evidence that microbiota-induced, Myd88-dependent signaling inhibits host Notch signaling in the intestinal epithelium, thereby promoting secretory cell fate determination. These results connect microbiota activity via innate immune signaling to the Notch pathway, which also plays crucial roles in intestinal homeostasis throughout life and when impaired can result in chronic inflammation and cancer. © 2018. Published by The Company of Biologists Ltd.

Airway extravasation induced by increasing airway temperature in ovalbumin-sensitized rats

PubMed Central

Hsu, Chun-Chun; Tapia, Reyno J.; Lee, Lu-Yuan

2015-01-01

This study was carried out to determine whether hyperventilation of humidified warm air (HWA) induced airway extravasation in ovalbumin (Ova)-sensitized rats. Our results showed: 1) After isocapnic hyperventilation with HWA for 2 min, tracheal temperature (Ttr) was increased to 40.3°C, and the Evans blue contents in major airways and lung tissue were elevated to 651% and 707%, respectively, of that after hyperventilation with humidified room air in Ova-sensitized rats; this striking effect of HWA was absent in control rats. 2) The HWA-induced increase in Evans blue content in sensitized rats was completely prevented by a pretreatment with either L-732138, a selective antagonist of neurokinin type 1 (NK-1) receptor, or formoterol, a selective agonist of β2 adrenoceptor. This study demonstrated that an increase in airway temperature induced protein extravasation in the major airways and lung tissue of sensitized rats, and an activation of the NK-1 receptor by tachykinins released from bronchopulmonary C-fiber nerve endings was primarily responsible. PMID:25864799

Aspergillus antigen induces robust Th2 cytokine production, inflammation, airway hyperreactivity and fibrosis in the absence of MCP-1 or CCR2.

PubMed

Koth, Laura L; Rodriguez, Madeleine W; Bernstein, Xin Liu; Chan, Salina; Huang, Xiaozhu; Charo, Israel F; Rollins, Barrett J; Erle, David J

2004-09-15

Asthma is characterized by type 2 T-helper cell (Th2) inflammation, goblet cell hyperplasia, airway hyperreactivity, and airway fibrosis. Monocyte chemoattractant protein-1 (MCP-1 or CCL2) and its receptor, CCR2, have been shown to play important roles in the development of Th2 inflammation. CCR2-deficient mice have been found to have altered inflammatory and physiologic responses in some models of experimental allergic asthma, but the role of CCR2 in contributing to inflammation and airway hyperreactivity appears to vary considerably between models. Furthermore, MCP-1-deficient mice have not previously been studied in models of experimental allergic asthma. To test whether MCP-1 and CCR2 are each required for the development of experimental allergic asthma, we applied an Aspergillus antigen-induced model of Th2 cytokine-driven allergic asthma associated with airway fibrosis to mice deficient in either MCP-1 or CCR2. Previous studies with live Aspergillus conidia instilled into the lung revealed that MCP-1 and CCR2 play a role in anti-fungal responses; in contrast, we used a non-viable Aspergillus antigen preparation known to induce a robust eosinophilic inflammatory response. We found that wild-type C57BL/6 mice developed eosinophilic airway inflammation, goblet cell hyperplasia, airway hyperreactivity, elevations in serum IgE, and airway fibrosis in response to airway challenge with Aspergillus antigen. Surprisingly, mice deficient in either MCP-1 or CCR2 had responses to Aspergillus antigen similar to those seen in wild-type mice, including production of Th2 cytokines. We conclude that robust Th2-mediated lung pathology can occur even in the complete absence of MCP-1 or CCR2.

Androgens are bronchoactive drugs that act by relaxing airway smooth muscle and preventing bronchospasm.

PubMed

Montaño, Luis M; Espinoza, Julia; Flores-Soto, Edgar; Chávez, Jaime; Perusquía, Mercedes

2014-07-01

Changes in the androgen levels in asthmatic men may be associated with the severity of asthma. Androgens induce a nongenomic relaxation in airway smooth muscle, but the underlying mechanisms remain unclear. The aim of this study was to investigate the potential bronchorelaxing action of testosterone (TES) and its metabolites (5α- and 5β-dihydrotestosterone (DHT). A preventive effect on ovalbumin (OVA)-induced bronchospasm was observed in sensitized guinea pigs for each androgen. Androgens were studied in response to bronchoconstrictors: carbachol (CCh) and KCl in isolated trachea rings with and without epithelium from non-sensitized and sensitized animals as well as on OVA-induced contraction. Androgens concentration-dependently abolished the contraction in response to CCh, KCl, and OVA. There were significant differences in the sensitivity to the relaxation induced by each androgen. 5β-DHT was more potent for relaxing KCl-induced contraction, while TES and 5α-DHT were more potent for CCh- and OVA-induced contraction. No differences were found in preparations with and without epithelium or in the presence of a nitric oxide (NO) synthase inhibitor or an inhibitor of K(+) channels. These data indicate the absence of involvement of the epithelium-, NO- and K(+) channels-dependent pathway in androgen-induced relaxation. However, in dissociated tracheal myocytes loaded with the calcium-binding fluorescent dye Fura -2, physiological concentrations of androgens decreased the KCl-induced [Ca(2+)]i increment. 5β-DHT was the most potent at decreasing KCl-induced [Ca(2+)]i increment and preventing bronchospasm. We suggest that androgen-induced brochorelaxation was mediated via decreased Ca(2+) influx through L-type Ca(2+)channels but additional Ca(2+) entry blockade may be involved. Molecular changes in androgen structure may determine its preferential site of action. © 2014 Society for Endocrinology.

Inhalation of honey reduces airway inflammation and histopathological changes in a rabbit model of ovalbumin-induced chronic asthma

PubMed Central

2014-01-01

Background Honey is widely used in folk medicine to treat cough, fever, and inflammation. In this study, the effect of aerosolised honey on airway tissues in a rabbit model of ovalbumin (OVA)-induced asthma was investigated. The ability of honey to act either as a rescuing agent in alleviating asthma-related symptoms or as a preventive agent to preclude the occurrence of asthma was also assessed. Methods Forty New Zealand white rabbits were sensitized twice with mixture of OVA and aluminium hydroxide on days 1 and 14. Honey treatments were given from day 23 to day 25 at two different doses (25% (v/v) and 50% (v/v) of honey diluted in sterile phosphate buffer saline. In the aerosolised honey as a rescue agent group, animals were euthanized on day 28; for the preventive group, animals were further exposed to aerosolised OVA for 3 days starting from day 28 and euthanized on day 31. The effects of honey on inflammatory cell response, airway inflammation, and goblet cell hyperplasia were assessed for each animal. Results Histopathological analyses revealed that aerosolised honey resulted in structural changes of the epithelium, mucosa, and submucosal regions of the airway that caused by the induction with OVA. Treatment with aerosolised honey has reduced the number of airway inflammatory cells present in bronchoalveolar lavage fluid and inhibited the goblet cell hyperplasia. Conclusion In this study, aerosolised honey was used to effectively treat and manage asthma in rabbits, and it could prove to be a promising treatment for asthma in humans. Future studies with a larger sample size and studies at the gene expression level are needed to better understand the mechanisms by which aerosolised honey reduces asthma symptoms. PMID:24886260

Interleukin-1beta-induced airway hyperresponsiveness enhances substance P in intrinsic neurons of ferret airway.

PubMed

Wu, Z-X; Satterfield, B E; Fedan, J S; Dey, R D

2002-11-01

Interleukin (IL)-1beta causes airway inflammation, enhances airway smooth muscle responsiveness, and alters neurotransmitter expression in sensory, sympathetic, and myenteric neurons. This study examines the role of intrinsic airway neurons in airway hyperresponsiveness (AHR) induced by IL-1beta. Ferrets were instilled intratracheally with IL-1beta (0.3 microg/0.3 ml) or saline (0.3 ml) once daily for 5 days. Tracheal smooth muscle contractility in vitro and substance P (SP) expression in tracheal neurons were assessed. Tracheal smooth muscle reactivity to acetylcholine (ACh) and methacholine (MCh) and smooth muscle contractions to electric field stimulation (EFS) both increased after IL-1beta. The IL-1beta-induced AHR was maintained in tracheal segments cultured for 24 h, a procedure that depletes SP from sensory nerves while maintaining viability of intrinsic airway neurons. Pretreatment with CP-99994, an antagonist of neurokinin 1 receptor, attenuated the IL-1beta-induced hyperreactivity to ACh and MCh and to EFS in cultured tracheal segments. SP-containing neurons in longitudinal trunk, SP innervation of superficial muscular plexus neurons, and SP nerve fiber density in tracheal smooth muscle all increased after treatment with IL-1beta. These results show that IL-1beta-enhanced cholinergic airway smooth muscle contractile responses are mediated by the actions of SP released from intrinsic airway neurons.

[Effect of airway humidification on lung injury induced by mechanical ventilation].

PubMed

Song, Junjie; Jiang, Min; Qi, Guiyan; Xie, Yuying; Wang, Huaiquan; Tian, Yonggang; Qu, Jingdong; Zhang, Xiaoming; Li, Haibo

2014-12-01

To explore the effect of airway humidification on lung injury as a result of mechanical ventilation with different tidal volume (VT). Twenty-four male Japanese white rabbits were randomly divided into four groups: low VT with airway humidification group, high VT with airway humidification group, low VT and high VT group without humidification, with 6 rabbits in each group. Mechanical ventilation was started after intubation and lasted for 6 hours. Low VT denoted 8 mL/kg, while high VT was 16 mL/kg, fraction of inspired oxygen (FiO₂) denoted 0.40, positive end-expiratory pressure (PEEP) was 0. Temperature at Y piece of circuit in airway humidification groups was monitored and controlled at 40 centigrade. Arterial blood gas analysis, including pH value, arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), lung mechanics indexes, including peak airway pressure (P(peak)) and airway resistance (Raw), and lung compliance was measured at 0, 2, 4, 6 hours of mechanical ventilation. The levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in plasma and bronchoalveolar lavage fluid (BALF) were determined by enzyme linked immunosorbent assay (ELISA). The animals were sacrificed at the end of mechanical ventilation. The wet to dry (W/D) ratio of lung tissues was calculated. Histopathologic changes in the lung tissueies were observed with microscope, and lung injury score was calculated. Scanning and transmission electron microscopies were used to examine the integrity of the airway cilia and the tracheal epithelium. Compared with low V(T) group, pH value in high V(T) group was significantly increased, PaCO₂was significantly lowered, and no difference in PaO₂was found. P(peak), Raw, and lung compliance were significantly increased during mechanical ventilation. There were no significant differences in blood gas analysis and lung mechanics indexes between low V(T) with airway humidification group and low V

Combined Effects of Ventilation Mode and Positive End-Expiratory Pressure on Mechanics, Gas Exchange and the Epithelium in Mice with Acute Lung Injury

PubMed Central

Thammanomai, Apiradee; Hamakawa, Hiroshi; Bartolák-Suki, Erzsébet; Suki, Béla

2013-01-01

The accepted protocol to ventilate patients with acute lung injury is to use low tidal volume (VT) in combination with recruitment maneuvers or positive end-expiratory pressure (PEEP). However, an important aspect of mechanical ventilation has not been considered: the combined effects of PEEP and ventilation modes on the integrity of the epithelium. Additionally, it is implicitly assumed that the best PEEP-VT combination also protects the epithelium. We aimed to investigate the effects of ventilation mode and PEEP on respiratory mechanics, peak airway pressures and gas exchange as well as on lung surfactant and epithelial cell integrity in mice with acute lung injury. HCl-injured mice were ventilated at PEEPs of 3 and 6 cmH2O with conventional ventilation (CV), CV with intermittent large breaths (CVLB) to promote recruitment, and a new mode, variable ventilation, optimized for mice (VVN). Mechanics and gas exchange were measured during ventilation and surfactant protein (SP)-B, proSP-B and E-cadherin levels were determined from lavage and lung homogenate. PEEP had a significant effect on mechanics, gas exchange and the epithelium. The higher PEEP reduced lung collapse and improved mechanics and gas exchange but it also down regulated surfactant release and production and increased epithelial cell injury. While CVLB was better than CV, VVN outperformed CVLB in recruitment, reduced epithelial injury and, via a dynamic mechanotransduction, it also triggered increased release and production of surfactant. For long-term outcome, selection of optimal PEEP and ventilation mode may be based on balancing lung physiology with epithelial injury. PMID:23326543

The role of the small airways in the pathophysiology of asthma and chronic obstructive pulmonary disease.

PubMed

Bonini, Matteo; Usmani, Omar S

2015-12-01

Chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), represent a major social and economic burden for worldwide health systems. During recent years, increasing attention has been directed to the role of small airways in respiratory diseases, and their exact contribution to the pathophysiology of asthma and COPD continues to be clarified. Indeed, it has been suggested that small airways play a distinct role in specific disease phenotypes. Besides providing information on small airways structure and diagnostic procedures, this review therefore aims to present updated and evidence-based findings on the role of small airways in the pathophysiology of asthma and COPD. Most of the available information derives from either pathological studies or review articles and there are few data on the natural history of small airways disease in the onset or progression of asthma and COPD. Comparisons between studies on the role of small airways are hard to draw because both asthma and COPD are highly heterogeneous conditions. Most studies have been performed in small population samples, and different techniques to characterize aspects of small airways function have been employed in order to assess inflammation and remodelling. Most methods of assessing small airways dysfunction have been largely confined to research purposes, but some data are encouraging, supporting the utilization of certain techniques into daily clinical practice, particularly for early-stage diseases, when subjects are often asymptomatic and routine pulmonary function tests may be within normal ranges. In this context further clinical trials and real-life feedback on large populations are desirable. © The Author(s), 2015.

Spatial distribution of airway wall displacements during breathing and bronchoconstriction measured by ultrasound elastography using finite element image registration.

PubMed

Harvey, Brian C; Lutchen, Kenneth R; Barbone, Paul E

2017-03-01

With every breath, the airways within the lungs are strained. This periodic stretching is thought to play an important role in determining airway caliber in health and disease. Particularly, deep breaths can mitigate excessive airway narrowing in healthy subjects, but this beneficial effect is absent in asthmatics, perhaps due to an inability to stretch the airway smooth muscle (ASM) embedded within an airway wall. The heterogeneous composition throughout an airway wall likely modulates the strain felt by the ASM but the magnitude of ASM strain is difficult to measure directly. In this study, we optimized a finite element image registration method to measure the spatial distribution of displacements and strains throughout an airway wall during pressure inflation within the physiological breathing range before and after induced narrowing with acetylcholine (ACh). The method was shown to be repeatable, and displacements estimated from different image sequences of the same deformation agreed to within 5.3μm (0.77%). We found the magnitude and spatial distribution of displacements were radially and longitudinally heterogeneous. The region in the middle layer of the airway experienced the largest radial strain due to a transmural pressure (Ptm) increase simulating tidal breathing and a deep inspiration (DI), while the region containing the ASM (i.e., closest to the lumen) strained least. During induced narrowing with ACh, we observed temporal longitudinal heterogeneity of the airway wall. After constriction, the displacements and strain are much smaller than the relaxed airway and the pattern of strains changed, suggesting the airway stiffened heterogeneously. Copyright © 2016 Elsevier B.V. All rights reserved.

Region-specific role for Pten in maintenance of epithelial phenotype and integrity

PubMed Central

Flodby, Per; Sunohara, Mitsuhiro; Castillo, Dan R.; McConnell, Alicia M.; Krishnaveni, Manda S.; Banfalvi, Agnes; Li, Min; Stripp, Barry; Zhou, Beiyun; Crandall, Edward D.; Minoo, Parviz

2017-01-01

Previous studies have demonstrated resistance to naphthalene-induced injury in proximal airways of mice with lung epithelial-specific deletion of the tumor-suppressor gene Pten, attributed to increased proliferation of airway progenitors. We tested effects of Pten loss following bleomycin injury, a model typically used to study distal lung epithelial injury, in conditional PtenSFTPC-cre knockout mice. Pten-deficient airway epithelium exhibited marked hyperplasia, particularly in small bronchioles and at bronchoalveolar duct junctions, with reduced E-cadherin and β-catenin expression between cells toward the luminal aspect of the hyperplastic epithelium. Bronchiolar epithelial and alveolar epithelial type II (AT2) cells in PtenSFTPC-cre mice showed decreased expression of epithelial markers and increased expression of mesenchymal markers, suggesting at least partial epithelial-mesenchymal transition at baseline. Surprisingly, and in contrast to previous studies, mutant mice were exquisitely sensitive to bleomycin, manifesting rapid weight loss, respiratory distress, increased early mortality (by day 5), and reduced dynamic lung compliance. This was accompanied by sloughing of the hyperplastic airway epithelium with occlusion of small bronchioles by cellular debris, without evidence of increased parenchymal lung injury. Increased airway epithelial cell apoptosis due to loss of antioxidant defenses, reflected by decreased expression of superoxide dismutase 3, in combination with deficient intercellular adhesion, likely predisposed to airway sloughing in knockout mice. These findings demonstrate an important role for Pten in maintenance of airway epithelial phenotype integrity and indicate that responses to Pten deletion in respiratory epithelium following acute lung injury are highly context-dependent and region-specific. PMID:27864284

Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epithelia.

PubMed

Hatakeyama, S; Yaegashi, T; Oikawa, Y; Fujiwara, H; Mikami, T; Takeda, Y; Satoh, M

2006-08-01

The gingival epithelium is the physiologically important interface between the bacterially colonized gingival sulcus and periodontal soft and mineralized connective tissues, requiring protection from exposure to bacteria and their products. However, of the three epithelia comprising the gingival epithelium, the junctional epithelium has much wider intercellular spaces than the sulcular epithelium and oral gingival epithelium. Hence, the aim of the present study was to characterize the cell adhesion structure in the junctional epithelium compared with the other two epithelia. Gingival epithelia excised at therapeutic flap surgery from patients with periodontitis were examined for expression of adhesion molecules by immunofluorescence. In the oral gingival epithelium and sulcular epithelium, but not in the junctional epithelium, desmoglein 1 and 2 in cell-cell contact sites were more abundant in the upper than the suprabasal layers. E-cadherin, the main transmembranous molecule of adherens junctions, was present in spinous layers of the oral gingival epithelium and sulcular epithelium, but was scarce in the junctional epithelium. In contrast, desmoglein 3 and P-cadherin were present in all layers of the junctional epithelium as well as the oral gingival epithelium and sulcular epithelium. Connexin 43 was clearly localized to spinous layers of the oral gingival epithelium, sulcular epithelium and parts of the junctional epithelium. Claudin-1 and occludin were expressed in the cell membranes of a few superficial layers of the oral gingival epithelium. These findings indicated that the junctional epithelium contains only a few desmosomes, composed of only desmoglein 3; adherens junctions are probably absent because of defective E-cadherin. Thus, the anchoring junctions connecting junctional epithelium cells are lax, causing widened intercellular spaces. In contrast, the oral gingival epithelium, which has a few tight junctions, functions as a barrier.

A 'Good' muscle in a 'Bad' environment: the importance of airway smooth muscle force adaptation to airway hyperresponsiveness.

PubMed

Bossé, Ynuk; Chapman, David G; Paré, Peter D; King, Gregory G; Salome, Cheryl M

2011-12-15

Asthma is characterized by airway inflammation, with a consequent increase in spasmogens, and exaggerated airway narrowing in response to stimuli, termed airway hyperresponsiveness (AHR). The nature of any relationship between inflammation and AHR is less clear. Recent ex vivo data has suggested a novel mechanism by which inflammation may lead to AHR, in which increased basal ASM-tone, due to the presence of spasmogens in the airways, may "strengthen" the ASM and ultimately lead to exaggerated airway narrowing. This phenomenon was termed "force adaptation" [Bossé, Y., Chin, L.Y., Paré, P.D., Seow, C.Y., 2009. Adaptation of airway smooth muscle to basal tone: relevance to airway hyperresponsiveness. Am. J. Respir. Cell Mol. Biol. 40, 13-18]. However, it is unknown whether the magnitude of the effect of force adaptation ex vivo could contribute to exaggerated airway narrowing in vivo. Our aim was to utilize a computational model of ASM shortening in order to quantify the potential effect of force adaptation on airway narrowing when all other mechanical factors were kept constant. The shortening in the model is dictated by a balance between physiological loads and ASM force-generating capacity at different lengths. The results suggest that the magnitude of the effect of force adaptation on ASM shortening would lead to substantially more airway narrowing during bronchial challenge at any given airway generation. We speculate that the increased basal ASM-tone in asthma, due to the presence of inflammation-derived spasmogens, produces an increase in the force-generating capacity of ASM, predisposing to AHR during subsequent challenge. Copyright © 2011 Elsevier B.V. All rights reserved.

Mechanotransduction, asthma, and airway smooth muscle

PubMed Central

Fabry, Ben; Fredberg, Jeffrey J.

2008-01-01

Excessive force generation by airway smooth muscle is the main culprit in excessive airway narrowing during an asthma attack. The maximum force the airway smooth muscle can generate is exquisitely sensitive to muscle length fluctuations during breathing, and is governed by complex mechanotransduction events that can best be studied by a hybrid approach in which the airway wall is modeled in silico so as to set a dynamic muscle load comparable to that experienced in vivo. PMID:18836522

Cardiovascular causes of airway compression.

PubMed

Kussman, Barry D; Geva, Tal; McGowan, Francis X

2004-01-01

Compression of the paediatric airway is a relatively common and often unrecognized complication of congenital cardiac and aortic arch anomalies. Airway obstruction may be the result of an anomalous relationship between the tracheobronchial tree and vascular structures (producing a vascular ring) or the result of extrinsic compression caused by dilated pulmonary arteries, left atrial enlargement, massive cardiomegaly, or intraluminal bronchial obstruction. A high index of suspicion of mechanical airway compression should be maintained in infants and children with recurrent respiratory difficulties, stridor, wheezing, dysphagia, or apnoea unexplained by other causes. Prompt diagnosis is required to avoid death and minimize airway damage. In addition to plain chest radiography and echocardiography, diagnostic investigations may consist of barium oesophagography, magnetic resonance imaging (MRI), computed tomography, cardiac catheterization and bronchoscopy. The most important recent advance is MRI, which can produce high quality three-dimensional reconstruction of all anatomic elements allowing for precise anatomic delineation and improved surgical planning. Anaesthetic technique will depend on the type of vascular ring and the presence of any congenital heart disease or intrinsic lesions of the tracheobronchial tree. Vascular rings may be repaired through a conventional posterolateral thoracotomy, or utilizing video-assisted thoracoscopic surgery (VATS) or robotic endoscopic surgery. Persistent airway obstruction following surgical repair may be due to residual compression, secondary airway wall instability (malacia), or intrinsic lesions of the airway. Simultaneous repair of cardiac defects and vascular tracheobronchial compression carries a higher risk of morbidity and mortality.

Oxidative airway inflammation leads to systemic and vascular oxidative stress in a murine model of allergic asthma.

PubMed

Al-Harbi, Naif O; Nadeem, A; Al-Harbi, Mohamed M; Imam, F; Al-Shabanah, Othman A; Ahmad, Sheikh F; Sayed-Ahmed, Mohamed M; Bahashwan, Saleh A

2015-05-01

Oxidant-antioxidant imbalance plays an important role in repeated cycles of airway inflammation observed in asthma. It is when reactive oxygen species (ROS) overwhelm antioxidant defenses that a severe inflammatory state becomes apparent and may impact vasculature. Several studies have shown an association between airway inflammation and cardiovascular complications; however so far none has investigated the link between airway oxidative stress and systemic/vascular oxidative stress in a murine model of asthma. Therefore, this study investigated the contribution of oxidative stress encountered in asthmatic airways in modulation of vascular/systemic oxidant-antioxidant balance. Rats were sensitized intraperitoneally with ovalbumin (OVA) in the presence of aluminum hydroxide followed by several intranasal (i.n.) challenges with OVA. Rats were then assessed for airway and vascular inflammation, oxidative stress (ROS, lipid peroxides) and antioxidants measured as total antioxidant capacity (TAC) and thiol content. Challenge with OVA led to increased airway inflammation and oxidative stress with a concomitant increase in vascular inflammation and oxidative stress. Oxidative stress in the vasculature was significantly inhibited by antioxidant treatment, N-acetyl cysteine; whereas hydrogen peroxide (H2O2) inhalation worsened it. Therefore, our study shows that oxidative airway inflammation is associated with vascular/systemic oxidative stress which might predispose these patients to increased cardiovascular risk. Copyright © 2015 Elsevier B.V. All rights reserved.

Unusual epithelium in a subpubic sinus.

PubMed

Chao, Hong-Ming; Chuang, Chia-Jueng; Chen, Ke-Chi; Chu, Chih-Chun; Chou, Jung-Mao

2002-09-01

A 5-year-old male presented with the history of whitish discharge from a midline sinus opening just above the pubis for 2 months. Attempted radiography of the sinus revealed a blind fistula and voiding cystourethrography was normal. The fistula was excised deep to the subpubic space without any evidence of connection to the lower urinary tract. Pathologic evaluation of the lesion revealed a ciliated-columnar lining with stratified-squamous and transitional epithelium. To our knowledge, a subpubic sinus with this unique presentation of epithelium has not been reported previously.

21 CFR 868.2600 - Airway pressure monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper airway...

Awake Craniotomy: A New Airway Approach.

PubMed

Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

2016-02-01

Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique.

Airway structure and function in Eisenmenger's syndrome.

PubMed

McKay, K O; Johnson, P R; Black, J L; Glanville, A R; Armour, C L

1998-10-01

The responsiveness of airways from patients with Eisenmenger's syndrome (n = 5) was compared with that in airways from organ donors (n = 10). Enhanced contractile responses to cholinergic stimulation were found in airways from patients with Eisenmenger's syndrome. The maximal responses to acetylcholine, carbachol, and parasympathetic nerve stimulation in airway tissue from these patients were 221%, 139%, and 152%, respectively, of the maximal responses obtained in donor tissue. Further, relaxation responses to isoproterenol and levocromakalim were absent (n = 2) or markedly impaired (n = 3) in airways from patients with Eisenmenger's syndrome. This attenuated relaxation response was nonspecific in that it was also absent after vasoactive intestinal peptide, sodium nitroprusside, papaverine, and electrical field application. These observations can most likely be explained by a decrease in intrinsic smooth muscle tone, as precontraction of airways revealed relaxation responses that were equivalent to those obtained in donor tissues. Morphometric analysis of tissues used for the functional studies revealed no differences in the airway dimensions (internal perimeter) or airway wall components (e.g., smooth muscle, cartilage) or total area to explain these observations. Although the mechanism for this observed decrease in intrinsic airway smooth muscle tone is not certain, it may be due to alteration in the substructure of the airway wall or, alternatively, may result from the continued release of depressant factors in the vicinity of the smooth muscle which permanently alters smooth muscle responsiveness.

A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates.

PubMed

Hubble, Michael W; Wilfong, Denise A; Brown, Lawrence H; Hertelendy, Attila; Benner, Randall W

2010-01-01

Airway management is a key component of prehospital care for seriously ill and injured patients. Oral endotracheal intubation (OETI) is the definitive airway of choice in most emergency medical services (EMS) systems. However, OETI may not be an approved skill for some clinicians or may prove problematic in certain patients because of anatomic abnormalities, trauma, or inadequate relaxation. In these situations alternative airways are frequently employed. However, the reported success rates for these devices vary widely, and established benchmarks are lacking. We sought to determine pooled estimates of the success rates of alternative airway devices (AADs) and needle cricothyrotomy (NCRIC) and surgical cricothyrotomy (SCRIC) placement through a meta-analysis of the literature. We performed a systematic literature search for all English-language articles reporting success rates for AADs, SCRIC, and NCRIC. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique were calculated using a random-effects meta-analysis model. Of 2,005 prehospital airway titles identified, 35 unique studies were retained for analysis of AAD success rates, encompassing a total of 10,172 prehospital patients. The success rates for SCRIC and NCRIC were analyzed across an additional 21 studies totaling 512 patients. The pooled estimates (and 95% confidence intervals [CIs]) for intervention success across all clinicians and patients were as follows: esophageal obturator airway-esophageal gastric tube airway (EOA-EGTA) 92.6% (90.1%-94.5%); pharyngeotracheal lumen airway (PTLA) 82.1% (74.0%-88.0%); esophageal-tracheal Combitube (ETC) 85.4% (77.3%-91.0%); laryngeal mask airway (LMA) 87.4% (79.0%-92.8%); King Laryngeal Tube airway (King LT) 96.5% (71.2%-99.7%); NCRIC 65.8% (42.3%-83.59%); and SCRIC 90.5% (84

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

Coelomic epithelium-derived cells in visceral morphogenesis.

PubMed

Ariza, Laura; Carmona, Rita; Cañete, Ana; Cano, Elena; Muñoz-Chápuli, Ramón

2016-03-01

Coelomic cavities of vertebrates are lined by a mesothelium which develops from the lateral plate mesoderm. During development, the coelomic epithelium is a highly active cell layer, which locally is able to supply mesenchymal cells that contribute to the mesodermal elements of many organs and provide signals which are necessary for their development. The relevance of this process of mesenchymal cell supply to the developing organs is becoming clearer because genetic lineage tracing techniques have been developed in recent years. Body wall, heart, liver, lungs, gonads, and gastrointestinal tract are populated by cells derived from the coelomic epithelium which contribute to their connective and vascular tissues, and sometimes to specialized cell types such as the stellate cells of the liver, the Cajal interstitial cells of the gut or the Sertoli cells of the testicle. In this review we collect information about the contribution of coelomic epithelium derived cells to visceral development, their developmental fates and signaling functions. The common features displayed by all these processes suggest that the epithelial-mesenchymal transition of the embryonic coelomic epithelium is an underestimated but key event of vertebrate development, and probably it is shared by all the coelomate metazoans. © 2015 Wiley Periodicals, Inc.

Aspergillus antigen induces robust Th2 cytokine production, inflammation, airway hyperreactivity and fibrosis in the absence of MCP-1 or CCR2

PubMed Central

Koth, Laura L; Rodriguez, Madeleine W; Bernstein, Xin Liu; Chan, Salina; Huang, Xiaozhu; Charo, Israel F; Rollins, Barrett J; Erle, David J

2004-01-01

Background Asthma is characterized by type 2 T-helper cell (Th2) inflammation, goblet cell hyperplasia, airway hyperreactivity, and airway fibrosis. Monocyte chemoattractant protein-1 (MCP-1 or CCL2) and its receptor, CCR2, have been shown to play important roles in the development of Th2 inflammation. CCR2-deficient mice have been found to have altered inflammatory and physiologic responses in some models of experimental allergic asthma, but the role of CCR2 in contributing to inflammation and airway hyperreactivity appears to vary considerably between models. Furthermore, MCP-1-deficient mice have not previously been studied in models of experimental allergic asthma. Methods To test whether MCP-1 and CCR2 are each required for the development of experimental allergic asthma, we applied an Aspergillus antigen-induced model of Th2 cytokine-driven allergic asthma associated with airway fibrosis to mice deficient in either MCP-1 or CCR2. Previous studies with live Aspergillus conidia instilled into the lung revealed that MCP-1 and CCR2 play a role in anti-fungal responses; in contrast, we used a non-viable Aspergillus antigen preparation known to induce a robust eosinophilic inflammatory response. Results We found that wild-type C57BL/6 mice developed eosinophilic airway inflammation, goblet cell hyperplasia, airway hyperreactivity, elevations in serum IgE, and airway fibrosis in response to airway challenge with Aspergillus antigen. Surprisingly, mice deficient in either MCP-1 or CCR2 had responses to Aspergillus antigen similar to those seen in wild-type mice, including production of Th2 cytokines. Conclusion We conclude that robust Th2-mediated lung pathology can occur even in the complete absence of MCP-1 or CCR2. PMID:15377395

Investigating the geometry of pig airways using computed tomography