Home About us Contact | |||
Human Bronchial Epithelial Cells (human + bronchial_epithelial_cell)
Kinds of Human Bronchial Epithelial Cells Selected AbstractsGerman 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] 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] 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] 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] 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] 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] 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] 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] 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] |