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Bronchial Epithelial Cells (bronchial + epithelial_cell)
Kinds of Bronchial Epithelial Cells Selected AbstractsEthanol Blocks Adenosine Uptake via Inhibiting the Nucleoside Transport System in Bronchial Epithelial CellsALCOHOLISM, Issue 5 2009Diane S. Allen-Gipson Background:, Adenosine uptake into cells by nucleoside transporters plays a significant role in governing extracellular adenosine concentration. Extracellular adenosine is an important signaling molecule that modulates many cellular functions via 4 G-protein-coupled receptor subtypes (A1, A2A, A2B, and A3). Previously, we demonstrated that adenosine is critical in maintaining airway homeostasis and airway repair and that airway host defenses are impaired by alcohol. Taken together, we hypothesized that ethanol impairs adenosine uptake via the nucleoside transport system. Methods:, To examine ethanol-induced alteration on adenosine transport, we used a human bronchial epithelial cell line (BEAS-2B). Cells were preincubated for 10 minutes in the presence and absence of varying concentrations of ethanol (EtOH). In addition, some cells were pretreated with S-(4-Nitrobenzyl)-6-thioinosine (100 ,M: NBT), a potent adenosine uptake inhibitor. Uptake was then determined by addition of [3H]-adenosine at various time intervals. Results:, Increasing EtOH concentrations resulted in increasing inhibition of adenosine uptake when measured at 1 minute. Cells pretreated with NBT effectively blocked adenosine uptake. In addition, short-term EtOH revealed increased extracellular adenosine concentration. Conversely, adenosine transport became desensitized in cells exposed to EtOH (100 mM) for 24 hours. To determine the mechanism of EtOH-induced desensitization of adenosine transport, cAMP activity was assessed in response to EtOH. Short-term EtOH exposure (10 minutes) had little or no effect on adenosine-mediated cAMP activation, whereas long-term EtOH exposure (24 hours) blocked adenosine-mediated cAMP activation. Western blot analysis of lysates from unstimulated BEAS-2B cells detected a single 55 kDa band indicating the presence of hENT1 and hENT2, respectively. Real-time RT-PCR of RNA from BEAS-2B revealed transcriptional expression of ENT1 and ENT2. Conclusions:, Collectively, these data reveal that acute exposure of cells to EtOH inhibits adenosine uptake via a nucleoside transporter, and chronic exposure of cells to EtOH desensitizes the adenosine transporter to these inhibitory effects of ethanol. Furthermore, our data suggest that inhibition of adenosine uptake by EtOH leads to an increased extracellular adenosine accumulation, influencing the effect of adenosine at the epithelial cell surface, which may alter airway homeostasis. [source] Quantitative cytokine gene expression in CF airway,PEDIATRIC PULMONOLOGY, Issue 5 2004Marianne S. Muhlebach MD Abstract Bronchoalveolar lavage fluid (BALF) in cystic fibrosis (CF) shows increased inflammation, which could be due to abnormal cytokine regulation. Bronchial epithelial cells and migratory inflammatory cells produce these cytokines, but few quantitative in vivo data are available comparing young CF patients with controls. We hypothesized that IL-8 mRNA abundance was higher in young CF vs. non-CF disease control patients in lung epithelium and inflammatory cells. Bronchial epithelial cells (BEC) were obtained by brush biopsy, and airway inflammatory cells (BALFC) by bronchoalveolar lavage, in 17 CF and 21 non-CF patients <5 years old undergoing clinically indicated bronchoscopy. Cellular mRNA expression was quantified by real-time PCR and normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Abundance of IL-8/GAPDH in BEC was significantly higher in CF (14.8,±,3.3) than non-CF (4.2,±,0.6) samples, and this difference was also significant when patients were stratified according to infection. In BALFC, the difference in IL-8 expression did not reach statistical significance: CF (17.1,±,6.5) vs. non-CF (6.8,±,1.9), but BALF cell number/ml was significantly higher in CF. IL-10 mRNA was very low in all samples, without showing a decrease in CF vs. non-CF patients. We conclude that early in the disease, IL-8 mRNA expression in BEC is increased in CF in vivo. Although IL-8 mRNA in migratory cells was not significantly higher in CF, these cells may still contribute to elevated IL-8 in airway secretions, secondary to increased cell density in BALF. Pediatr Pulmonol. 2004; 37:393,399. © 2004 Wiely-Liss, Inc. [source] Induction of insulin-like growth factor-I by interleukin-17F in bronchial epithelial cellsCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2010M. Kawaguchi Summary Cite this as: M. Kawaguchi, J. Fujita, F. Kokubu, G. Ohara, S-K Huang, S. Matsukura, Y. Ishii, M. Adachi, H. Satoh and N. Hizawa, Clinical & Experimental Allergy, 2010 (40) 1036,1043. Background Increased expression of IL-17F has been noted in the airway of asthmatic patients, but its role in asthma has not been fully elucidated. Insulin-like growth factor-I (IGF-I) is known to be involved in airway remodelling and inflammation, while its regulatory mechanisms remain to be defined. Objective To further clarify the biological function of IL-17F, we investigated whether IL-17F is able to regulate the expression of IGF-I in bronchial epithelial cells. Methods Bronchial epithelial cells were stimulated with IL-17F in the presence or absence of T-helper type 2 cytokines. Various kinase inhibitors were added to the culture to identify the key signalling events leading to the expression of IGF-I, in conjunction with the use of short interfering RNAs (siRNAs) targeting mitogen- and stress-activated protein kinase (MSK) 1, p90 ribosomal S6 kinase (p90RSK), and cyclic AMP response element-binding protein (CREB). Results IL-17F significantly induced IGF-I gene and protein expression, and co-stimulation with IL-4 and IL-13 augmented its production. MAP kinase kinase (MEK) inhibitors and the Raf1 kinase inhibitor significantly inhibited IGF-I production, and the combination of PD98059 and Raf1 kinase inhibitor showed further inhibition. Overexpression of Raf1 and Ras dominant-negative mutants inhibited its expression. MSK1 inhibitors significantly blocked IL17F-induced IGF-I expression. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked its expression. Conclusions In bronchial epithelial cells, IL-17F is able to induce the expression of IGF-I via the Raf1,MEK1/2,ERK1/2,MSK1/p90RSK,CREB pathway in vitro. [source] Toluene diisocyanate enhances human bronchial epithelial cells' permeability partly through the vascular endothelial growth factor pathwayCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2009H. Zhao Summary Background Toluene diisocyanate (TDI) is a recognized chemical asthmogen; yet, the mechanisms of its toxicity have not been elucidated. Objective To investigate the influence of TDI on the permeability of human bronchial epithelial cell (HBE; HBE135-E6E7) monolayers in vitro, and the expression of vascular endothelial growth factor (VEGF) in these cells. Methods TDI,human serum albumin (HSA) conjugates were prepared by a modification of Son's method. Fluorescein isothiocyanate-labelled dextran and transmission electron microscopy were used to evaluate the effects of TDI,HSA on HBE135-E6E7 permeability. RT-PCR and ELISA were used to evaluate VEGF gene expression and protein release from HBE135-E6E7 cells stimulated by TDI,HSA. A VEGF-neutralizing antibody was used in monolayer permeability experiments to determine the role of the VEGF pathway in this process. Results TDI,HSA significantly increased the permeability coefficients of HBE135-E6E7 monolayers (P<0.01). TDI,HSA treatment significantly increased the expression of VEGF165 and VEGF189 genes (P<0.01). ELISA showed that TDI significantly induces VEGF release from HBE135-E6E7 cells. Cells treated with TDI,HSA and VEGF-neutralizing antibody had significantly lower permeability coefficients than cells treated with TDI,HSA only (P<0.01), but still significantly higher than control cells (P<0.01). Cells treated with TDI,HSA had fewer tight junctions (TJs) than control and HSA-treated cells, and addition of the anti-VEGF antibody did not restore the original number of TJs. Conclusion TDI increases the permeability of HBE cell monolayers, partly through a VEGF-mediated pathway. This suggests the importance of VEGF in TDI-induced pulmonary diseases, but shows that other pathways may be involved in the pathogenic process. [source] Rhinovirus infection and house dust mite exposure synergize in inducing bronchial epithelial cell interleukin-8 releaseCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2008A. Bossios Summary Background Human rhinoviruses (HRVs) and house dust mites (HDMs) are among the most common environmental factors able to induce airway inflammation in asthma. Although epidemiological studies suggest that they also synergize in inducing asthma exacerbations, there is no experimental evidence to support this, nor any information on the possible mechanisms involved. Objective To investigate their interaction on the induction of airway epithelial inflammatory responses in vitro. Methods BEAS-2B cells were exposed to activated HDM Dermatophagoides pteronyssinus major allergen I (Der p I), HRVs (HRV1b or HRV16) or both in different sequences. IL-8/CXCL8 release, intercellular adhesion molecule (ICAM)-1 surface expression and nuclear factor ,B (NF-,B) translocation were evaluated. Complementary, primary human bronchial epithelial cells (HBECs) exposed to both Der p I and RVs and IL-8, IL-6, IFN-,-induced protein (IP)-10/CXCL10, IFN-,1/IL-29, regulated upon activation normal T lymphocyte expressed and secreted (RANTES)/CCL5 release were measured. Results RV and Der p I up-regulated IL-8 release, ICAM-1 expression and NF-,B translocation in BEAS-2B cells. Simultaneous exposure to both factors, as well as when cells were initially exposed to HRV and then to Der p I, resulted in further induction of IL-8 in a synergistic manner. Synergism was not observed when cells were initially exposed to Der p I and then to HRV. This was the pattern in ICAM-1 induction although the phenomenon was not synergistic. Concurrent exposure induced an early synergistic NF-,B translocation induction, differentiating with time, partly explaining the above observation. In HBECs, both HRV and Der p I induced IL-8, IL-6, IL-29 and IP-10, while RANTES was induced only by HRV. Synergistic induction was observed only in IL-8. Conclusion HRV and enzymatically active Der p I can act synergistically in the induction of bronchial epithelial IL-8 release, when HRV infection precedes or is concurrent with Der p I exposure. Such a synergy may represent an important mechanism in virus-induced asthma exacerbations. [source] Rhinovirus increases human ,-defensin-2 and -3 mRNA expression in cultured bronchial epithelial cellsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2003Louise A Duits Abstract Human ,-defensins (hBDs) are antimicrobial peptides that play important roles in host defense against infection, inflammation and immunity. Previous studies showed that micro-organisms and proinflammatory mediators regulate the expression of these peptides in airway epithelial cells. The aim of the present study was to investigate the modulation of expression of hBDs in cultured primary bronchial epithelial cells (PBEC) by rhinovirus-16 (RV16), a respiratory virus responsible for the common cold and associated with asthma exacerbations. RV16 was found to induce expression of hBD-2 and -3 mRNA in PBEC, but did not affect hBD-1 mRNA. Viral replication appeared essential for rhinovirus-induced ,-defensin mRNA expression, since UV-inactivated rhinovirus did not increase expression of hBD-2 and hBD-3 mRNA. Exposure to synthetic double-stranded RNA (dsRNA) molecule polyinosinic:polycytidylic acid had a similar effect as RV16 on mRNA expression of these peptides in PBEC. In line with this, PBEC were found to express TLR3, a Toll-like receptor involved in recognition of dsRNA. This study shows that rhinovirus infection of PBEC leads to increased hBD-2 and hBD-3 mRNA expression, which may play a role in both the uncomplicated common cold and in virus-associated exacerbations of asthma. [source] Lactoferrin decreases pollen antigen-induced allergic airway inflammation in a murine model of asthmaIMMUNOLOGY, Issue 2 2006Marian L. Kruzel Summary Pollen grains contain reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidases and in contact with mucosal surfaces generate superoxide anion (O2,,). In the presence of iron, O2,, may be converted to more reactive oxygen radicals, such as to H2O2 and/or ,OH, which may augment antigen-induced airway inflammation. The aim of the study was to examine the impact of lactoferrin (LF), an iron-binding protein, on ragweed (Ambrosia artemisiifolia) pollen extract (RWE)-induced cellular oxidative stress levels in cultured bronchial epithelial cells and accumulation of inflammatory and mucin-producing cells in airways in a mouse model of allergic airway inflammation. Results show that LF lowered RWE-induced increase in cellular reactive oxygen species (ROS) levels in bronchial epithelial cells. Most importantly, LF significantly decreased accumulation of eosinophils into airways and subepithelium of intranasally challenged, sensitized mice. LF also prevented development of mucin-producing cells. Amb a 1, the major allergenic ragweed pollen antigen lacking NAD(P)H oxidase activity, induced low-grade airway inflammation. When administered along with glucose oxidase (G-ox), a superoxide-generating enzyme, Amb a 1 induced robust airway inflammation, which was significantly lowered by LF. Surprisingly, LF decreased also inflammation caused by Amb a 1 alone. Iron-saturated hololactoferrin had only a marginal effect on RWE-induced cellular ROS levels and RWE- or Amb a 1 plus G-ox-induced inflammation. We postulate that free iron in the airways chemically reduces O2,, to more reactive species which augment antigen-induced inflammation in a mouse model of asthma. Our results suggest the utility of LF in human allergic inflammatory disorders. [source] Role for dipeptidyl peptidase IV in tumor suppression of human non small cell lung carcinoma cellsINTERNATIONAL JOURNAL OF CANCER, Issue 6 2004Umadevi V. Wesley Abstract Lung cancer is the leading cause of cancer death. Lung cancers produce a variety of mitogenic growth factors that stimulate tumor cell proliferation and migration. The cell surface protease, dipeptidyl peptidase IV (DPPIV), is involved in diverse biologic functions, including peptide-mediated cellular growth and differentiation. DPPIV is expressed in various normal tissues, including lung tissue, and its expression is lost in many types of human cancers. DPPIV expression and its enzymatic activity are detected in normal bronchial and alveolar epithelium but different histologic subtypes of lung carcinomas lose DPPIV expression. To investigate the role of DPPIV in lung carcinoma, we examined the expression of DPPIV at both mRNA and protein levels in non small cell lung cancer (NSCLC) cell lines and normal human bronchial epithelial cells. DPPIV expression was detectable in normal lung epithelial cells, but was absent or markedly reduced in all NSCLC cell lines at both mRNA and protein levels. Restoration of DPPIV expression in NSCLC cells resulted in profound morphologic changes, inhibition of cell proliferation, anchorage-independent growth, in vitro cell migration and tumorigenicity in nude mice. DPPIV reexpression also correlated with increased p21 expression, leading to induction of apoptosis and cell cycle arrest in G1 stage. These effects were accompanied by increased expression of cell surface proteins, fibroblast-activating protein (Fap,) and CD44 that are associated with suppression of tumor growth and metastasis. Thus, DPPIV functions as a tumor suppressor, and its downregulation may contribute to the loss of growth control in NSCLC cells. © 2004 Wiley-Liss, Inc. [source] Cigarette smoke extract affects functional activity of MRP1 in bronchial epithelial cellsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2007Margaretha van der Deen Abstract Cigarette smoke is the principal risk factor for development of chronic obstructive pulmonary disease (COPD). Multidrug resistance-associated protein 1 (MRP1) is a member of the ATP-binding cassette (ABC) superfamily of transporters, which transport physiologic and toxic substrates across cell membranes. MRP1 is highly expressed in lung epithelium. This study aims to analyze the effect of cigarette smoke extract (CSE) on MRP1 activity. In the human bronchial epithelial cell line 16HBE14o,, MRP1 function was studied flow cytometrically by cellular retention of carboxyfluorescein (CF) after CSE incubation and MRP1 downregulation by RNA interference (siRNA). Cell survival was measured by the MTT assay. Immunocytochemically, it was shown that 16HBE14o, expressed MRP1 and breast cancer resistance protein. Coincubation of CSE IC50 (1.53% ± 0.22%) with MK571 further decreased cell survival 31% (p, = 0.018). CSE increased cellular CF retention dose dependently from 1.7-fold at 5% CSE to 10.3-fold at 40% CSE (both p < 0.05). siRNA reduced MRP1 RNA expression with 49% and increased CF accumulation 67% versus control transfected cells. CSE exposure further increased CF retention 24% (p = 0.031). A linear positive relation between MRP1 function and CSE-modulating effects (r = 0.99, p =0.089) was shown in untransfected, control transfected, and MRP1 downregulated 16HBE14o, cells analogous to blocking effects with MRP1 inhibitor MK571 (r = 0.99, p = 0.034). In conclusion, cigarette smoke extract affects MRP1 activity probably competitively in bronchial epithelial cells. Inhibition of MRP1 in turn results in higher CSE toxicity. We propose that MRP1 may be a protective protein for COPD development. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:243,251, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20187 [source] Expression of SLURP-1, an endogenous ,7 nicotinic acetylcholine receptor allosteric ligand, in murine bronchial epithelial cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 12 2009Kazuhide Horiguchi Abstract Mammalian secreted lymphocyte antigen-6/urokinase-type plasminogen activator receptor-related peptide-1 (SLURP-1) is a positive allosteric ligand for ,7 nicotinic acetylcholine (ACh) receptors (,7 nAChRs) that potentiates responses to ACh and elicits proapoptotic activity in human keratinocytes. Mutations in the gene encoding SLURP-1 have been detected in patients with Mal de Meleda, a rare autosomal recessive skin disorder characterized by transgressive palmoplantar keratoderma. On the basis of these findings, SLURP-1 is postulated to be involved in regulating tumor necrosis factor-, (TNF-,) release from keratinocytes and macrophages via ,7 nAChR-mediated pathways. In the present study, we assessed SLURP-1 expression in lung tissue from C57BL/6J mice to investigate the functions of SLURP-1 in pulmonary physiology and pathology. Immunohistochemical and in situ hybridization analyses revealed expression of SLURP-1 protein and mRNA, respectively, exclusively in ciliated bronchial epithelial cells. This was supported by Western blotting showing the presence of the 9.5-kDa SLURP-1 protein in whole-lung tissue and trachea. In addition, high-affinity choline transporter (CHT1) was detected in apical regions of bronchial epithelial cells and in neurons located in the lamina propria of the bronchus, suggesting that bronchial epithelial cells are able to synthesize both SLURP-1 and ACh. We also observed direct contact between F4/80-positive macrophages and bronchial epithelial cells and the presence of invading macrophages in close proximity to CHT1-positive nerve elements. Collectively, these results suggest that SLURP-1 contributes to the maintenance of bronchial epithelial cell homeostasis and to the regulation of TNF-, release from macrophages in bronchial tissue. © 2009 Wiley-Liss, Inc. [source] Alcohol Functionally Upregulates Toll-Like Receptor 2 in Airway Epithelial CellsALCOHOLISM, Issue 3 2009Kristina L. Bailey Background:, Alcoholics are known to have more severe airway diseases of the lung, such as bronchitis. Little is known about why this phenomenon is observed. We hypothesized that alcohol may modulate Toll-like receptor 2 (TLR2), which regulates inflammation caused by gram-positive bacteria. Methods:, Airway epithelial cells [primary bronchial epithelial cells (NHBE) and 16HBE 14o-] were exposed to 0 to 100 mM alcohol for 0 to 24 hours. Real time PCR was used to quantify TLR2 mRNA. Protein levels of TLR2 were determined using Western blots and fluorescence activated cell sorting (FACS) on cells exposed to 0, 50, and 100 mM alcohol. Finally, cells were "primed" with alcohol, stimulated with a TLR2 agonist (peptidoglycan), and interleukin 8 (IL-8) release was measured. Results:, Alcohol, at biologically relevant concentrations (25 to 100 mM), caused a 2 to 3-fold time- and concentration-dependent increase in TLR2 mRNA in normal human bronchial epithelial cells and 16HBE 14o- cells. Western blots for TLR2 revealed a qualitative increase in TLR2 protein in cells exposed to 100 mM alcohol. FACS showed that TLR2 was quantitatively increased on the surface of airway epithelial cells that were exposed to alcohol. Airway cells that were primed with alcohol produced nearly twice as much IL-8 in response to 40 ng of peptidoglycan than naive cells. Conclusions:, Alcohol upregulates TLR2 message and protein in the airway epithelium. This leads to exaggerated inflammation in response to environmental stimuli that would normally be well tolerated in airway epithelial cells. This may be a partial explanation of why alcoholics have more severe airway disease than nonalcoholics. [source] Alcohol Primes the Airway for Increased Interleukin-13 SignalingALCOHOLISM, Issue 3 2009Patrick O. Mitchell Background:, Using an experimental model of airway fibrosis following lung transplantation, we recently showed that chronic alcohol ingestion by donor rats amplifies airway fibrosis in the recipient. Associated with alcohol-mediated amplification of airway fibrosis is increased transforming growth factor ,-1(TGF,1) and ,-smooth muscle actin expression. Other studies have shown that interleukin-13 (IL-13) modulates TGF,1 signaling during experimentally-induced airway fibrosis. Therefore, we hypothesized that IL-13 is a component of alcohol-mediated amplification of pro-fibrotic mediators in the alcoholic lung. Methods:, To test this hypothesis, we analyzed tracheal epithelial cells and type II alveolar cells from control- or alcohol-fed rats, alcohol-treated mouse lung fibroblasts, and human bronchial epithelial cells in vitro for expression of various components of the IL-13 signaling pathway. Signaling via the IL-13 pathway was assessed by measuring levels of phosphorylated signal transducers and activators of transcription-6 (STAT6). In addition, we performed heterotopic tracheal transplantation using control-fed and alcohol-fed donor rats and analyzed tracheal allografts for expression of components of the IL-13 signaling pathway by RT-PCR and immunocytochemical analyses. Results:, Interleukin-13 expression was detected in type II alveolar epithelial cells and human bronchial epithelial cells, but not in lung fibroblasts. IL-13 expression was decreased in whole lung and type II cells in response to alcohol exposure. In all cell types analyzed, expression of IL-13 signaling receptor (IL-13R,1) mRNA was markedly increased. In contrast, mRNA and protein expression of the IL-13 decoy receptor (IL-13R,2) were decreased in all cells analyzed. Exposure to alcohol also increased STAT6 phosphorylation in response to IL-13 and lipopolysaccharide. Conclusions:, Data from multiple cell types in the pulmonary system suggest that IL-13 and its receptors play a role in alcohol-mediated activation of pro-fibrotic pathways. Taken together, these data suggest that alcohol primes the airway for increased IL-13 signaling and subsequent tissue remodeling upon injury such as transplantation. [source] Ethanol Treatment Reduces Bovine Bronchial Epithelial Cell MigrationALCOHOLISM, Issue 4 2005John R. Spurzem Background: Chronic ethanol abuse is associated with significant lung disease. Excessive alcohol intake increases risk for a variety of respiratory tract diseases, including pneumonia and bronchitis. Damage to airway epithelium is critical to the pathogenesis of airway disorders such as chronic bronchitis and chronic obstructive pulmonary disease. The ability of the airway epithelium to repair itself is an important step in the resolution of airway inflammation and disease. Ethanol exposure is known to modulate signaling systems in bronchial epithelial cells. We hypothesize that chronic ethanol exposure down-regulates the adenosine 3,:5,-cyclic monophosphate signaling cascade in airway epithelial cells, resulting in decreased epithelial cell migration and repair. Methods: We evaluated the effect of ethanol on primary cultures of bovine bronchial epithelial cells in in vitro models of cell migration, wound repair, cell attachment, and cell spreading. Results: Ethanol causes a concentration-dependent effect on closure of mechanical wounds in cell monolayers. Pretreatment of cells with 100 mm ethanol for 24 hr further slows wound closure. Ethanol pretreatment also reduced the protein kinase A response to wounding and made the cells unresponsive to stimuli of protein kinase A that accelerate wound closure. The effects of ethanol on cell migration in wound closure were confirmed in another assay of migration, the Boyden chamber cell migration assay. Prolonged treatment with ethanol also reduced other cell functions, such as spreading and attachment, which are necessary for epithelial repair. Conclusions: Ethanol modulates signaling systems that are relevant to airway injury and repair, suggesting that chronic, heavy ethanol ingestion has a detrimental impact on airway repair. Impaired response to inflammation and injury may contribute to chronic airway disease. [source] Respiratory virus induction of alpha-, beta- and lambda-interferons in bronchial epithelial cells and peripheral blood mononuclear cellsALLERGY, Issue 3 2009M. R. Khaitov Background:, Respiratory viruses, predominantly rhinoviruses are the major cause of asthma exacerbations. Impaired production of interferon-, in rhinovirus infected bronchial epithelial cells (BECs) and of the newly discovered interferon-,s in both BECs and bronchoalveolar lavage cells, is implicated in asthma exacerbation pathogenesis. Thus replacement of deficient interferon is a candidate new therapy for asthma exacerbations. Rhinoviruses and other respiratory viruses infect both BECs and macrophages, but their relative capacities for ,-, ,- and ,-interferon production are unknown. Methods:, To provide guidance regarding which interferon type is the best candidate for development for treatment/prevention of asthma exacerbations we investigated respiratory virus induction of ,-, ,- and ,-interferons in BECs and peripheral blood mononuclear cells (PBMCs) by reverse transferase-polymerase chain reaction and enzyme-linked immunosorbent assay. Results:, Rhinovirus infection of BEAS-2B BECs induced interferon-, mRNA expression transiently at 8 h and interferon-, later at 24 h while induction of interferon-, was strongly induced at both time points. At 24 h, interferon-, protein was not detected, interferon-, was weakly induced while interferon-, was strongly induced. Similar patterns of mRNA induction were observed in primary BECs, in response to both rhinovirus and influenza A virus infection, though protein levels were below assay detection limits. In PBMCs interferon-,, interferon-, and interferon-, mRNAs were all strongly induced by rhinovirus at both 8 and 24 h and proteins were induced: interferon-,>-,>-,. Thus respiratory viruses induced expression of ,-, ,- and ,-interferons in BECs and PBMCs. In PBMCs interferon-,>-,>-, while in BECs, interferon-,>-,>-,. Conclusions:, We conclude that interferon-,s are likely the principal interferons produced during innate responses to respiratory viruses in BECs and interferon-,s in PBMCs, while interferon-, is produced by both cell types. [source] German cockroach proteases regulate matrix metalloproteinase-9 in human bronchial epithelial cellsALLERGY, Issue 8 2006K. Page Background:, Matrix metalloproteinases (MMPs) digest extracellular matrix proteins and may play a role in the pathogenesis of bronchial asthma. MMP-9 levels are increased in the bronchoalveolar lavage fluid and sputum of asthmatics compared with that of controls. As exposure to cockroaches is an environmental risk factor for asthma, we sought to investigate the role of German cockroach fecal remnants (frass) on MMP-9 expression. Methods:, Human bronchial epithelial cells (16HBE14o-) and primary normal human bronchial epithelial cells were treated with cockroach frass in the absence or presence of tumor necrosis factor (TNF),. MMP-9 mRNA, protein levels and pro-MMP-9 activity were determined using real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and zymogram assays. Pretreatment of frass with aprotinin abolished protease activity. PD98059, a chemical inhibitor of extracellular signal regulated kinase (ERK), and SLIGKV, an activator of protease-activated receptor (PAR)-2 were also used. AP-1DNA binding was determined by electrophoretic mobility shift assay (EMSA) and ERK phosphorylation by Western blot analysis. Results:, Cockroach frass augmented TNF, -mediated MMP-9 mRNA and protein expression by a mechanism dependent on active serine proteases within frass and not on endogenous endotoxin. Frass increased ERK phosphorylation, and chemical inhibition of ERK attenuated cockroaches' effects on MMP-9. Serine proteases are known to activate the PAR-2 receptor. We found that selective activation of PAR-2 using the peptide SLIGKV augmented TNF, -induced MMP-9 protein levels and increased ERK phosphorylation. Frass and SLIGKV each increased AP-1 translocation and DNA binding. Conclusions:, These data suggest that German cockroach frass contains active serine proteases which augment TNF, -induced MMP-9 expression by a mechanism involving PAR-2, ERK and AP-1. [source] Lipoxins in asthma: potential therapeutic mediators on bronchial inflammation?ALLERGY, Issue 10 2004C. Bonnans Arachidonic acid metabolism represents an important source of mediators with ambivalent actions. Among these, lipoxins (LXs) are the first agents identified and recognized as anti-inflammatory endogenous lipid mediators, which are involved in the resolution of inflammation and are present in the airways of asthmatic patients. Lipoxins result mainly from the interaction between 5 and 15-lipoxygenases (LO) and their levels are modulated by the degree of bronchial inflammation as well as by the long-term glucocorticoid treatments. In the airways, LX synthesis is higher in mild asthmatics than in severe asthmatics, whereas in vitro chemokine release inhibition by LXs is more effective in cells from severe asthmatics than from mild asthmatics. LipoxinA4 effects on interleukin (IL)-8 released by blood mononuclear cells and on calcium influx in epithelial cells are mediated by the specific receptor ALX. Lipoxin generation by lung epithelial cells depends mainly on 15-LO activity. Mild asthmatics present higher 15-LOb expression at the epithelium level than severe patients, whereas the LX deficit in severe asthma is associated with an up-regulation of the 15-LOa expressions. Therefore, bronchial epithelial cells become a target for therapeutic intervention and LXs represent a potential therapeutic solution for bronchial inflammation resolution in asthma. [source] Loss of Betaig-h3 protein is frequent in primary lung carcinoma and related to tumorigenic phenotype in lung cancer cellsMOLECULAR CARCINOGENESIS, Issue 2 2006Yongliang Zhao Abstract Betaig-h3 as a secreted protein induced by transforming growth factor-, has been suggested to modulate cell adhesion and tumor formation. Although we have previously shown that downregulation of Betaig-h3 gene is involved in the cellular transformation of human bronchial epithelial cells induced by radiation, its regulation in primary human lung cancers is not clearly understood. In this study, Betaig-h3 expression was studied in 130 primary human lung carcinomas by immunohistochemistry. Betaig-h3 protein was absent or reduced by more than two-fold in 45 of 130 primary lung carcinomas relative to normal lung tissues examined. Recovery of Betaig-h3 expression in H522 lung cancer cells lacking endogenous Betaig-h3 protein significantly suppressed their in vitro cellular growth and in vivo tumorigenicity. In addition, parental H522 cancer cells are resistant to the etoposide induced apoptosis compared with normal human bronchial epithelial cells. However, recovery of Betaig-h3 expression in H522 cancer cells results in significantly higher sensitivity to apoptotic induction than parental tumor cells. IGFBP3 is upregulated in Betaigh3-transfected H522 cells that may mediate the apoptotic sensitivity and antitumor function of Betaig-h3 gene. These observations demonstrate that downregulation of Betaig-h3 gene is a frequent event and related to the tumor progression in human lung cancer. © 2005 Wiley-Liss, Inc. [source] Cytokine induction by respiratory syncytial virus and adenovirus in bronchial epithelial cellsPEDIATRIC PULMONOLOGY, Issue 3 2007Jong-Seo Yoon MD Abstract In order to broaden our knowledge of the primary immune responses to respiratory syncytial virus (RSV) and adenovirus infections, we compared the concentrations of interleukin (IL)-6, IL-8, and regulated on activation, normal T cell expressed and secreted (RANTES) produced in vitro during RSV and adenovirus infections of bronchial epithelial cells. We infected BEAS-2B cells,a human bronchial epithelial cell line,with RSV, adenovirus serotype 3, or serotype 7 and measured the concentrations of IL-6, IL-8, and RANTES in the cell culture supernatants. When the multiplicity of infection (MOI) was 1, RSV induced the production of markedly higher concentrations of IL-6, IL-8, and RANTES than the adenovirus. When the MOI of the adenovirus was increased to 100, the production of IL-6 and IL-8 increased. However, the amounts produced were still lower than those produced by RSV with the MOI of 1. There was no statistically significant increase in the production of RANTES in spite of the MOI of the adenovirus was increased to 100. Adenovirus serotype 7 induced the production of considerably more IL-6 and IL-8 than serotype 3 in the MOI of 100. However, neither adenovirus serotype triggered an increase in the production of RANTES in spite of the MOI of 100. This demonstrates that RSV could have a superior capacity to stimulate the production of IL-6, IL-8, and RANTES in the bronchial epithelial cells. This study may help to explain the differences in the clinical outcomes of RSV and adenovirus infections. Pediatr Pulmonol. 2007; 42:277,282. © 2007 Wiley-Liss, Inc. [source] Analysis of gene expression in human bronchial epithelial cells upon influenza virus infection and regulation by p38 mitogen-activated protein kinase and c-Jun-N-terminal kinaseRESPIROLOGY, Issue 2 2008Shinichi HAYASHI Background and objective: Airway epithelial cells, which are the initial site of influenza virus (IV) infection, participate in the inflammatory process through the expression of various genes. In this process, mitogen-activated protein kinase (MAPK) may be associated with the expression of many genes, but its precise role remains unknown. Methods: A comprehensive analysis was performed of gene expression in human bronchial epithelial cells upon IV infection, using an Affymetrix gene chip containing 12 000 genes. Regulation of gene expression by MAPK was also analysed. Results: A total of 5998 genes were detected. Upon IV infection, 165 genes were upregulated and 49 of these were interferon-stimulated genes. The functions of 129 genes, including 14 apoptosis-related genes and 6 antiviral genes, were well characterized; however, those of 36 genes were unknown. The expression of 29 genes was inhibited either by SB 203580, a specific inhibitor of p38 MAPK, or by CEP-11004, a specific inhibitor of the c-Jun-N-terminal kinase (JNK) cascade, and the percentage inhibition by SB 203580 correlated with that by CEP-11004, suggesting that p38 and JNK participate in a common downstream pathway involved in the regulation of gene expression. p38 MAPK- or JNK-dependent genes were functionally classified into diverse categories. Conclusions: Although further studies are needed to obtain a more complete understanding of gene expression and the role of MAPK in gene expression, the present results are important in understanding the molecular mechanisms involved in the response of bronchial epithelial cells to IV infection. [source] Infection of replication-deficient adenoviral vector enhances interleukin-8 production in small airway epithelial cells more than in large airway epithelial cellsRESPIROLOGY, Issue 4 2001YUZO KODAMA Objective: In clinical trials or experiments of gene therapy, airway administration of an adenoviral-based vector (E1A-deleted) elicits a dose-dependent inflammatory response with limitation in the duration of transgene expression. The purpose of this study was to evaluate the possibility that the adenoviral-based vector directly enhances IL-8 production independent of adenoviral E1A in normal human airway epithelial cells and to examine the different responses between primary human bronchial epithelial cells (HBE) and primary human small airway epithelial cells (HSAE) in production of IL-8 following exposure to an adenovirus vector. Methodology: Interleukin (IL)-8 levels were evaluated in the culture medium from HBE and HSAE treated with increasing doses of E1A-deleted adenoviral vector contained the Escherichia coli LacZ reporter gene (AdCMVLacZ). To clarify the mechanism of enhancing IL-8 production in airway epithelial cells by infection with adenovirus vector, ,v,5 agonistic antibody as an analogue of adenoviral capsid and adenoviral capsid vector denatured by exposure to ultraviolet (UV) light were used in the present study. Results: Inoculation of HBE with AdCMVLacZ at a multiplicity of infection (MOI) of between 1 and 200 resulted in a dose-dependent expression of LacZ, and maximal expression was observed at a MOI of 100. In contrast, inoculation of HSAE with AdCMVLacZ resulted in maximum expression of LacZ at a MOI of 10. Interleukin-8 levels in culture media from the same experiments revealed significantly greater production of IL-8 in HSAE inoculated with AdCMVLacZ at a MOI of 50, compared to HBE under the same conditions. The capsid-denatured adenoviral vector did not enhance IL-8 production, and ,v,5 agonistic antibody induced IL-8 enhancement. Conclusion: These results suggest that the adenoviral vector directly induces the expression of airway epithelial inflammatory cytokines in the pathogenesis of inflammation and that small airway cells have a greater affinity for adenovirus than other airway epithelial cells. [source] N -acetyl- L -cysteine inhibits bleomycin-induced interleukin-8 secretion by bronchial epithelial cellsRESPIROLOGY, Issue 4 2000Yasuhiro Gon Objective: Bleomycin (BLM) has proven effective for the treatment of cancers, but the most serious dose-limiting side-effect is the development of pulmonary toxicity. Although the precise mechanism in the pathogenesis of BLM-induced lung injury has not been determined, oxygen radicals and neutrophils are indicated to play a key role in it. Interleukin-8 (IL-8) is thought to be an important mediator of the pathogenesis of acute lung injury. Methodology: The IL-8 production from bronchial epithelial cell line, BEAS-2B cells was measured by enzyme-linked immunosorbent assays for IL-8. Results: The concentrations of IL-8 were reportedly elevated in BLM-induced lung injury, suggesting the involvement of IL-8 in the pathogenesis of BLM-induced lung injury. In the present study, we showed that BLM induced the expression of IL-8 protein and mRNA in BEAS-2B cells, and N -acetyl- L -cysteine (NAC) inhibited IL-8 expression. In addition, the structurally unrelated anti-oxidant, pyrrolidine dithiocarbamate (PDTC) also effectively inhibited BLM-induced IL-8 production. Conclusion: These results suggest that anti-oxidant-sensitive mechanism might be involved in the inhibition of IL-8 secretion by BLM-stimulated bronchial epithelial cells and that NAC might be useful for the treatment of BLM-induced lung injury. [source] Inflammation and Epithelial to Mesenchymal Transition in Lung Transplant Recipients: Role in Dysregulated Epithelial Wound RepairAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010L. A. Borthwick Epithelial to mesenchymal transition (EMT) has been implicated in the pathogenesis of obliterative bronchiolitis (OB) after lung transplant. Although TNF-, accentuates TGF-,1 driven EMT in primary human bronchial epithelial cells (PBECs), we hypothesized that other acute pro-inflammatory cytokines elevated in the airways of patients with OB may also accentuate EMT and contribute to dysregulated epithelial wound repair. PBECs from lung transplant recipients were stimulated with TGF-,1 ± IL-1,, IL-8, TNF-, or activated macrophages in co-culture and EMT assessed. The quality and rate of wound closure in a standardized model of lung epithelial injury was assessed in response to above stimuli. Co-treatment with TGF-,1 + TNF-, or IL-1, significantly accentuates phenotypic and some functional features of EMT compared to TGF-,1 alone. Co-treatment with TGF-,1 + TNF-, or IL-1, accelerates epithelial wound closure however the quality of repair is highly dysregulated. Co-treatment with TGF-,1 + IL-8 has no significant effect on EMT or the speed or quality of wound healing. Activated macrophages dramatically accentuate TGF-,1-driven EMT and cause dysregulated wound repair. Crosstalk between macrophage-derived acute inflammation in the airway and elevated TGF-,1 may favor dysregulated airway epithelial repair and fibrosis in the lung allograft via EMT. [source] Immunohistochemical Study of HLA-G Expression in Lung Transplant RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2009O Brugière Human leukocyte antigen-G (HLA-G), a nonclassical HLA class I protein, promotes immune tolerance of solid-organ allografts, yet its role in lung transplantation (LTx) is unknown. We examined the expression of HLA-G in lung allografts through immunohistochemistry by a cross-sectional study of 64 LTx recipients, classified into four groups (stable patients, acute rejection [AR], bronchiolitis obliterans syndrome [BOS] and symptomatic viral shedders). A marked expression of HLA-G in bronchial epithelial cells (BEC) was frequently observed in stable recipients (n = 18/35 [51%]), but not in patients with AR (n = 14) or with BOS (n = 8). HLA-G was also expressed by 4 of 7 symptomatic viral shedders. In addition, HLA-G-positive patients from the stable group (n = 35) experienced lower incidence of resistant AR and/or BOS during long-term follow-up, as compared with their HLA-G-negative counterparts. Finally, in vitro data showed that interferon-,, a cytokine present in lung allograft microenvironment, upregulated HLA-G mRNA and protein expression in primary cultured human BEC. We conclude that HLA-G expression in the bronchial epithelium of lung allograft is elevated in some LTx recipients in association with their functional stability, suggesting a potential role of HLA-G as a tolerance marker. [source] Posttransplant Bronchiolitis Obliterans Syndrome Is Associated with Bronchial Epithelial to Mesenchymal TransitionAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009S. Hodge Bronchiolitis obliterans syndrome (BOS) compromises lung transplant outcomes and is characterised by airway epithelial damage and fibrosis. The process whereby the normal epithelial configuration is replaced by fibroblastic scar tissue is poorly understood, but recent studies have implicated epithelial mesenchymal transition (EMT). The primary aim of this study was to assess the utility of flow cytometry in detecting and quantifying EMT in bronchial epithelial cells. Large airway brushings were obtained at 33 bronchoscopies in 16 BOS-free and 6 BOS grade 1,3 patients at 2,120 months posttransplant. Flow cytometry was used to assess expression of the mesenchymal markers ,SMA, S100A4 and ED-A FN and HLA-DR. TGF ,1 and HGF were measured in Bronchoalveolar lavage (BAL). Expression of all three mesenchymal markers was increased in BOS, as was HLA-DR. BAL HGF, but not TGF ,1 was increased in BOS. Longitudinal investigation of one patient revealed a 100% increase in EMT markers concurrent with a 6-fold increase in BAL TGF ,1 and the diagnosis of BOS at 17 months posttransplant. Flow cytometric evaluation of bronchial epithelium may provide a novel and rapid means to assess lung allografts at risk of BOS. [source] Soluble membrane-type 1 matrix metalloproteinase (MT1-MMP) and gelatinase A (MMP-2) in induced sputum and bronchoalveolar lavage fluid of human bronchial asthma and bronchiectasisAPMIS, Issue 11 2002PÄIVI MAISI The aim of this study was to investigate the involvement of the MT1-MMP/MMP-2 cascade in induced sputum (IS) and bronchoalveolar lavage fluid (BALF) from bronchial asthma (BA) and bronchiectasis (BE) patients and healthy controls. The molecular forms and cellular origins of MT1-MMP and MMP-2 were determined by Western immunoblotting, immunohistochemistry and in situ hybridization. Elevated levels of soluble activated and autocatalyzed MT1-MMP species as well as activated forms of MMP-2 in IS and BALF samples from BA and BE patients were evidenced. The activation degrees of soluble MT1-MMP and MMP-2 were significantly correlated in BA and BE IS and BALF. Only low levels of both these MMPs were observed in healthy control IS and BALF. The co-expression of MMP-2 with MT1-MMP was evidenced by double immunostaining in bronchial epithelial cells, submucosal glandular cells, smooth muscle cells and monocyte/macrophages. The MT1-MMP/MMP-2 cascade is present and active in human inflammatory lung disease fluid and tissue samples. This cascade seemingly reflects the active destructive phases of these chronic lung diseases. [source] Induction of glucocorticoid receptor-, expression in epithelial cells of asthmatic airways by T-helper type 17 cytokinesCLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2010A. Vazquez-Tello Summary Background Corticosteroid insensitivity in asthmatics is associated with an increased expression of glucocorticoid receptor-, (GR-,) in many cell types. T-helper type 17 (Th17) cytokine (IL-17A and F) expressions increase in mild and in difficult-to-treat asthma. We hypothesize that IL-17A and F cytokines alone or in combination, induce the expression of GR-, in bronchial epithelial cells. Objectives To confirm the expression of the GR-, and IL-17 cytokines in the airways of normal subjects and mild asthmatics and to examine the effect of cytokines IL-17A and F on the expression of GR-, in bronchial epithelial cells obtained from normal subjects and asthmatic patients. Methods The expression of IL-17A and F, GR-, and GR-, was analysed in bronchial biopsies from mild asthmatics and normal subjects by Q-RT-PCR. Immunohistochemistry for IL-17 and GR-, was performed in bronchial biopsies from normal and asthmatic subjects. The expression of IL-6 in response to IL-17A and F and dexamethasone was determined by Q-RT-PCR using primary airway epithelial cells from normal and asthmatic subjects. Results We detected significantly higher levels of IL-17A mRNA expression in the bronchial biopsies from mild asthmatics, compared with normal. GR-, expression was significantly lower in the biopsies from asthmatics compared with controls. The expression of IL-17F and GR-, in biopsies from asthmatics was not significantly different from that of controls. Using primary epithelial cells isolated from normal subjects and asthmatics, we found an increased expression of GR-, in response to IL-17A and F in the cells from asthmatics (P0.05). This effect was only partially significant in the normal cells. Dexamethasone significantly decreased the IL-17-induced IL-6 expression in cells from normal individuals but not in those from asthmatics (P0.05). Conclusion Evidence of an increased GR-, expression in epithelial cells following IL-17 stimulation suggests a possible role for Th17-associated cytokines in the mechanism of steroid hypo-responsiveness in asthmatic subjects. Cite this as: A. Vazquez-Tello, A. Semlali, J. Chakir, J. G. Martin, D. Y. Leung, D. H. Eidelman and Q. Hamid, Clinical & Experimental Allergy, 2010 (40) 1312,1322. [source] Induction of insulin-like growth factor-I by interleukin-17F in bronchial epithelial cellsCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2010M. Kawaguchi Summary Cite this as: M. Kawaguchi, J. Fujita, F. Kokubu, G. Ohara, S-K Huang, S. Matsukura, Y. Ishii, M. Adachi, H. Satoh and N. Hizawa, Clinical & Experimental Allergy, 2010 (40) 1036,1043. Background Increased expression of IL-17F has been noted in the airway of asthmatic patients, but its role in asthma has not been fully elucidated. Insulin-like growth factor-I (IGF-I) is known to be involved in airway remodelling and inflammation, while its regulatory mechanisms remain to be defined. Objective To further clarify the biological function of IL-17F, we investigated whether IL-17F is able to regulate the expression of IGF-I in bronchial epithelial cells. Methods Bronchial epithelial cells were stimulated with IL-17F in the presence or absence of T-helper type 2 cytokines. Various kinase inhibitors were added to the culture to identify the key signalling events leading to the expression of IGF-I, in conjunction with the use of short interfering RNAs (siRNAs) targeting mitogen- and stress-activated protein kinase (MSK) 1, p90 ribosomal S6 kinase (p90RSK), and cyclic AMP response element-binding protein (CREB). Results IL-17F significantly induced IGF-I gene and protein expression, and co-stimulation with IL-4 and IL-13 augmented its production. MAP kinase kinase (MEK) inhibitors and the Raf1 kinase inhibitor significantly inhibited IGF-I production, and the combination of PD98059 and Raf1 kinase inhibitor showed further inhibition. Overexpression of Raf1 and Ras dominant-negative mutants inhibited its expression. MSK1 inhibitors significantly blocked IL17F-induced IGF-I expression. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked its expression. Conclusions In bronchial epithelial cells, IL-17F is able to induce the expression of IGF-I via the Raf1,MEK1/2,ERK1/2,MSK1/p90RSK,CREB pathway in vitro. [source] Rhinovirus infection and house dust mite exposure synergize in inducing bronchial epithelial cell interleukin-8 releaseCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2008A. Bossios Summary Background Human rhinoviruses (HRVs) and house dust mites (HDMs) are among the most common environmental factors able to induce airway inflammation in asthma. Although epidemiological studies suggest that they also synergize in inducing asthma exacerbations, there is no experimental evidence to support this, nor any information on the possible mechanisms involved. Objective To investigate their interaction on the induction of airway epithelial inflammatory responses in vitro. Methods BEAS-2B cells were exposed to activated HDM Dermatophagoides pteronyssinus major allergen I (Der p I), HRVs (HRV1b or HRV16) or both in different sequences. IL-8/CXCL8 release, intercellular adhesion molecule (ICAM)-1 surface expression and nuclear factor ,B (NF-,B) translocation were evaluated. Complementary, primary human bronchial epithelial cells (HBECs) exposed to both Der p I and RVs and IL-8, IL-6, IFN-,-induced protein (IP)-10/CXCL10, IFN-,1/IL-29, regulated upon activation normal T lymphocyte expressed and secreted (RANTES)/CCL5 release were measured. Results RV and Der p I up-regulated IL-8 release, ICAM-1 expression and NF-,B translocation in BEAS-2B cells. Simultaneous exposure to both factors, as well as when cells were initially exposed to HRV and then to Der p I, resulted in further induction of IL-8 in a synergistic manner. Synergism was not observed when cells were initially exposed to Der p I and then to HRV. This was the pattern in ICAM-1 induction although the phenomenon was not synergistic. Concurrent exposure induced an early synergistic NF-,B translocation induction, differentiating with time, partly explaining the above observation. In HBECs, both HRV and Der p I induced IL-8, IL-6, IL-29 and IP-10, while RANTES was induced only by HRV. Synergistic induction was observed only in IL-8. Conclusion HRV and enzymatically active Der p I can act synergistically in the induction of bronchial epithelial IL-8 release, when HRV infection precedes or is concurrent with Der p I exposure. Such a synergy may represent an important mechanism in virus-induced asthma exacerbations. [source] Synthetic double-stranded RNA induces multiple genes related to inflammation through Toll-like receptor 3 depending on NF-,B and/or IRF-3 in airway epithelial cellsCLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2006S. Matsukura Summary Background We hypothesized that synthetic double-stranded (ds)RNA may mimic viral infection and induce expression of genes related to inflammation in airway epithelial cells. Objective We analysed what gene was up-regulated by synthetic dsRNA poly I : C and then focused this study on the role of Toll-like receptor 3 (TLR3), a receptor of dsRNA and its transcriptional pathway. Methods Airway epithelial cell BEAS-2B and normal human bronchial epithelial cells were cultured in vitro. Expression of targets RNA and protein were analysed by PCR and ELISA. Localization of TLR3 expression in the cells was analysed with flow cytometry. To analyse the role of TLR3 and transcription factors, knockdown of these genes was performed with short interfering RNA (siRNA). Results Real-time PCR revealed that poly I : C significantly increased the expression of mRNAs for chemokines IP-10, RANTES, LARC, MIP-1,, IL-8, GRO-, and ENA-78 and cytokines IL-1,, GM-CSF, IL-6 and the cell adhesion molecule ICAM-1 in both cell types. Increases in protein levels were also observed. Expression of these genes was significantly inhibited in BEAS-2B cells in which TLR3 expression was knocked down. However, pre-treatment with anti-TLR3 mAb, which interferes with the function of TLR3 expressed on the cell surface, did not inhibit the genes expression and these data were concordant with the results that TLR3 was expressed inside airway epithelial cells. The study of siRNA for NF-,B and IRF3 showed that they transduce the signal of poly I : C, but their roles were different in each target gene. Conclusion TLR3 is expressed inside airway epithelial cells and transduces synthetic dsRNA signals. These signals may increase expression of inflammatory cytokines, chemokines and ICAM-1 through activation of transcription factors NF-,B and/or IRF3 in airway epithelial cells. [source] Eating their way out of trouble: selective uptake of apoptotic eosinophils by bronchial epithelial cellsCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2004N. Farahi First page of article [source] | ||||||||||||||||||||||||||||