Neutrophil Extracellular DNA Traps Induce Autoantigen Production by Airway Epithelial Cells

The hypothesis of autoimmune involvement in asthma has received much recent interest. Autoantibodies, such as anti-cytokeratin (CK) 18, anti-CK19, and anti-α-enolase antibodies, react with self-antigens and are found at high levels in the sera of patients with severe asthma (SA). However, the mechanisms underlying autoantibody production in SA have not been fully determined. The present study was conducted to demonstrate that neutrophil extracellular DNA traps (NETs), cytotoxic molecules released from neutrophils, are a key player in the stimulation of airway epithelial cells (AECs) to produce autoantigens. This study showed that NETs significantly increased the intracellular expression of tissue transglutaminase (tTG) but did not affect that of CK18 in AECs. NETs induced the extracellular release of both tTG and CK18 in a concentration-dependent manner. Moreover, NETs directly degraded intracellularα-enolase into small fragments. However, antibodies against neutrophil elastase (NE) or myeloperoxidase (MPO) attenuated the effects of NETs on AECs. Furthermore, each NET isolated from healthy controls (HC), nonsevere asthma (NSA), and SA had different characteristics. Taken together, these findings suggest that AECs exposed to NETs may exhibit higher autoantigen production, especially in SA. Therefore, targeting of NETs may represent a new therapy for neutrophilic asthma with a high level of autoantigens.

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Poly-L-Arginine Induces Apoptosis of NCI-H292 Cells via ERK1/2 Signaling Pathway

Journal of Immunology Research ◽

10.1155/2018/3651743 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Ya-Ni Wang ◽

Ling-Ling Zhang ◽

Xiao-Yun Fan ◽

Sha-Sha Wu ◽

Sheng-Quan Zhang

Keyword(s):

Epithelial Cells ◽

Caspase 3 ◽

Underlying Mechanism ◽

Mitochondrial Pathway ◽

Airway Epithelial Cells ◽

Dependent Manner ◽

Airway Epithelial ◽

Cationic Protein ◽

Concentration Dependent Manner

Cationic protein is a cytotoxic protein secreted by eosinophils and takes part in the damage of airway epithelium in asthma. Poly-L-arginine (PLA), a synthetic cationic protein, is widely used to mimic the biological function of the natural cationic protein in vitro. Previous studies demonstrated the damage of the airway epithelial cells by cationic protein, but the molecular mechanism is unclear. The purpose of this study aimed at exploring whether PLA could induce apoptosis of human airway epithelial cells (NCI-H292) and the underlying mechanism. Methods. The morphology of apoptotic cells was observed by transmission electron microscopy. The rate of apoptosis was analyzed by flow cytometry (FCM). The expressions of the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), Bcl-2/Bax, and cleaved caspase-3 were assessed by western blot. Results. PLA can induce apoptosis in NCI-H292 cells in a concentration-dependent manner. Moreover, the phosphorylation of the ERK1/2 and the unbalance of Bcl2/Bax, as well as the activation of caspase-3, were involved in the PLA-induced apoptosis. Conclusions. PLA can induce the apoptosis in NCI-H292 cells, and this process at least involved the ERK1/2 and mitochondrial pathway. The results could have some indications in revealing the apoptotic damage of the airway epithelial cells. Besides, inhibition of cationic protein-induced apoptotic death in airway epithelial cells could be considered as a potential target of anti-injury or antiremodeling in asthmatics.

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MARCKS and HSP70 interactions regulate mucin secretion by human airway epithelial cells in vitro

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00337.2012 ◽

2013 ◽

Vol 304 (8) ◽

pp. L511-L518 ◽

Cited By ~ 13

Author(s):

Shijing Fang ◽

Anne L. Crews ◽

Wei Chen ◽

Joungjoa Park ◽

Qi Yin ◽

...

Keyword(s):

Epithelial Cells ◽

Fluorescent Protein ◽

Yellow Fluorescent Protein ◽

Airway Epithelial Cells ◽

Dependent Manner ◽

Airway Epithelial ◽

Mucin Secretion ◽

Concentration Dependent Manner

Myristoylated alanine-rich C kinase substrate (MARCKS) protein has been recognized as a key regulatory molecule controlling mucin secretion by airway epithelial cells in vitro and in vivo. We recently showed that two intracellular chaperones, heat shock protein 70 (HSP70) and cysteine string protein (CSP), associate with MARCKS in the secretory mechanism. To elucidate more fully MARCKS-HSP70 interactions in this process, studies were performed in well-differentiated normal human bronchial epithelial (NHBE) cells maintained in air-liquid interface culture utilizing specific pharmacological inhibition of HSP70 with pyrimidinone MAL3-101 and siRNA approaches. The results indicate that HSP70 interaction with MARCKS is enhanced after exposure of the cells to the protein kinase C activator/mucin secretagogue, phorbol 12-myristate 13-acetate (PMA). Pretreatment of NHBEs with MAL3-101 attenuated in a concentration-dependent manner PMA-stimulated mucin secretion and interactions among HSP70, MARCKS, and CSP. In additional studies, trafficking of MARCKS in living NHBE cells was investigated after transfecting cells with fluorescently tagged DNA constructs: MARCKS-yellow fluorescent protein, and/or HSP70-cyan fluorescent protein. Cells were treated with PMA 48 h posttransfection, and trafficking of the constructs was examined by confocal microscopy. MARCKS translocated rapidly from plasma membrane to cytoplasm, whereas HSP70 was observed in the cytoplasm and appeared to associate with MARCKS after PMA exposure. Pretreatment of cells with either MAL3-101 or HSP70 siRNA inhibited translocation of MARCKS. These results provide evidence of a role for HSP70 in mediating mucin secretion via interactions with MARCKS and that these interactions are critical for the cytoplasmic translocation of MARCKS upon its phosphorylation.

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Osteosarcoma Phenotype Is Inhibited by 3,4-Methylenedioxy-β-nitrostyrene

Sarcoma ◽

10.1155/2012/479712 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Patrick J. Messerschmitt ◽

Ashley N. Rettew ◽

Nicholas O. Schroeder ◽

Robert E. Brookover ◽

Avanti P. Jakatdar ◽

...

Keyword(s):

Epithelial Cells ◽

Cell Lines ◽

Colony Formation ◽

Metastatic Potential ◽

Airway Epithelial Cells ◽

Osteosarcoma Cell ◽

Dependent Manner ◽

Airway Epithelial ◽

Human Osteoblasts ◽

Metastatic Cell Line

β-nitrostyrene compounds, such as 3,4-methylenedioxy-β-nitrostyrene (MNS), inhibit growth and induce apoptosis in tumor cells, but no reports have investigated their role in osteosarcoma. In this study, human osteosarcoma cell families with cell lines of varying tumorigenic and metastatic potential were utilized. Scrape motility assays, colony formation assays, and colony survival assays were performed with osteosarcoma cell lines, both in the presence and absence of MNS. Effects of MNS on human osteoblasts and airway epithelial cells were assessed in monolayer cultures. MNS decreased metastatic cell line motility by 72–76% and colony formation by 95–100%. MNS consistently disrupted preformed colonies in a time-dependent and dose-dependent manner. MNS had similar effects on human osteoblasts but little effect on airway epithelial cells. An inactive analog of MNS had no detectable effects, demonstrating specificity. MNS decreases motility and colony formation of osteosarcoma cells and disrupts preformed cell colonies, while producing little effect on pulmonary epithelial cells.

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Human Papillomavirus Type 16 E6 Activates NF-κB, Induces cIAP-2 Expression, and Protects against Apoptosis in a PDZ Binding Motif-Dependent Manner

Journal of Virology ◽

10.1128/jvi.01942-05 ◽

2006 ◽

Vol 80 (11) ◽

pp. 5301-5307 ◽

Cited By ~ 96

Author(s):

Michael A. James ◽

John H. Lee ◽

Aloysius J. Klingelhutz

Keyword(s):

Human Papillomavirus ◽

Epithelial Cells ◽

Transcriptional Activation ◽

Pdz Domain ◽

Airway Epithelial Cells ◽

Binding Motif ◽

Dependent Manner ◽

Airway Epithelial ◽

Transcript Accumulation ◽

Human Telomerase Reverse Transcriptase

ABSTRACT Infection with human papillomavirus (HPV) is a critical factor in the pathogenesis of most cervical cancers and some aerodigestive cancers. The HPV E6 oncoprotein from high-risk HPV types contributes to the immortalization and transformation of cells by multiple mechanisms, including degradation of p53, transcriptional activation of human telomerase reverse transcriptase (hTERT), and degradation of several proteins containing PDZ domains. The ability of E6 to bind PDZ domain-containing proteins is independent of p53 degradation or hTERT activation but does correlate with oncogenic potential (R. A. Watson, M. Thomas, L. Banks, and S. Roberts, J. Cell Sci. 116:4925-4934, 2003) and is essential for induction of epithelial hyperplasia in vivo (M. L. Nguyen, M. M. Nguyen, D. Lee, A. E. Griep, and P. F. Lambert, J. Virol. 77:6957-6964, 2003). In this study, we found that HPV type 16 E6 was able to activate NF-κB in airway epithelial cells through the induction of nuclear binding activity of p52-containing NF-κB complexes in a PDZ binding motif-dependent manner. Transcript accumulation for the NF-κB-responsive antiapoptotic gene encoding cIAP-2 and binding of nuclear factors to the proximal NF-κB binding site of the cIAP-2 gene promoter are induced by E6 expression. Furthermore, E6 is able to protect cells from TNF-induced apoptosis. All of these E6-dependent phenotypes are dependent on the presence of the PDZ binding motif of E6. Our results imply a role for targeting of PDZ proteins by E6 in NF-κB activation and protection from apoptosis in airway epithelial cells.

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Effects of Air Pollution-Related Heavy Metals on the Viability and Inflammatory Responses of Human Airway Epithelial Cells

International Journal of Toxicology ◽

10.1177/1091581815575757 ◽

2015 ◽

Vol 34 (2) ◽

pp. 195-203 ◽

Cited By ~ 12

Author(s):

Akiko Honda ◽

Kenshi Tsuji ◽

Yugo Matsuda ◽

Tomohiro Hayashi ◽

Wataru Fukushima ◽

...

Keyword(s):

Heavy Metals ◽

Epithelial Cells ◽

Cell Viability ◽

Ambient Air ◽

Airway Epithelial Cells ◽

Oxidation States ◽

Dependent Manner ◽

Airway Epithelial ◽

Human Airway ◽

Human Airway Epithelial Cells

Various metals produced from human activity are ubiquitously detected in ambient air. The metals may lead to induction and/or exacerbation of respiratory diseases, but the significant metals and factors contributing to such diseases have not been identified. To compare the effects of each metal and different oxidation states of metals on human airway, we examined the viability and production of interleukin (IL)-6 and IL-8 using BEAS-2B cell line, derived from human airway epithelial cells. Airway epithelial cells were exposed to Mn2+, V4+, V5+, Cr3+, Cr6+, Zn2+, Ni2+, and Pb2+ at a concentration of 0.5, 5, 50, or 500 μmol/L for 24 hours. Mn and V decreased the cell viability in a concentration-dependent manner, and V5+ tended to have a greater effect than V4+. The Cr decreased the cell viability, and (Cr+6) at concentrations of 50 and 500 μmol/L was more toxic than (Cr+3). Zn at a concentration of 500 μmol/L greatly decreased the cell viability, whereas Ni at the same concentration increased it. Pb produced fewer changes. Mn and Ni at a concentration of 500 μmol/L induced the significant production of IL-6 and IL-8. However, most of the metals including (V+4, V+5), (Cr+3, Cr+6), Zn, and Pb inhibited the production of both IL-6 and IL-8. The present results indicate that various heavy metals have different effects on toxicity and the proinflammatory responses of airway epithelial cells, and those influences also depend on the oxidation states of the metals.

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Cultured Human Airway Epithelial Cells (Calu-3): A Model of Human Respiratory Function, Structure, and Inflammatory Responses

Critical Care Research and Practice ◽

10.1155/2010/394578 ◽

2010 ◽

Vol 2010 ◽

pp. 1-8 ◽

Cited By ~ 36

Author(s):

Yan Zhu ◽

Aaron Chidekel ◽

Thomas H. Shaffer

Keyword(s):

Epithelial Cells ◽

Cellular Response ◽

Inflammatory Responses ◽

Airway Epithelial Cells ◽

Treatment Modalities ◽

Positive Pressure ◽

Dependent Manner ◽

Airway Epithelial ◽

Human Airway ◽

Human Airway Epithelial Cells

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

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Apical location of ferroportin 1 in airway epithelia and its role in iron detoxification in the lung

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00456.2004 ◽

2005 ◽

Vol 289 (1) ◽

pp. L14-L23 ◽

Cited By ~ 28

Author(s):

Funmei Yang ◽

David J. Haile ◽

Xinchao Wang ◽

Lisa A. Dailey ◽

Jacqueline G. Stonehuerner ◽

...

Keyword(s):

Epithelial Cells ◽

Iron Homeostasis ◽

Imaging Techniques ◽

Basolateral Membrane ◽

Airway Epithelial Cells ◽

Dependent Manner ◽

Airway Epithelial ◽

Airway Epithelia ◽

Ferroportin 1 ◽

Immunofluorescence Labeling

Ferroportin 1 (FPN1; aka MTP1, IREG1, and SLC40A1), which was originally identified as a basolateral iron transporter crucial for nutritional iron absorption in the intestine, is expressed in airway epithelia and upregulated when these cells are exposed to iron. Using immunofluorescence labeling and confocal microscopic imaging techniques, we demonstrate that in human and rodent lungs, FPN1 localizes subcellularly to the apical but not basolateral membrane of the airway epithelial cells. The role of airway epithelial cells in iron mobilization in the lung was studied in an in vitro model of the polarized airway epithelium. Normal human bronchial epithelial cells, grown on membrane supports until differentiated, were exposed to iron, and the efficiency and direction of iron transportation were studied. We found that these cells can efficiently take up iron across the apical but not basolateral surface in a concentration-dependent manner. Most of the iron taken up by the cells is then released into the medium within 8 h in the form of less reactive protein-bound complexes including ferritin and transferrin. Interestingly, iron release also occurred across the apical but not basolateral membrane. Our findings indicate that FPN1, depending on its subcellular location, could have distinct functions in iron homeostasis in different cells and tissues. Although it is responsible for exporting nutrient iron from enterocytes to the circulation in the intestine, it could play a role in iron detoxification in airway epithelial cells in the lung.

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Neutrophil elastase increases secretory leukocyte protease inhibitor transcript levels in airway epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1993.265.3.l286 ◽

1993 ◽

Vol 265 (3) ◽

pp. L286-L292 ◽

Cited By ~ 10

Author(s):

J. M. Abbinante-Nissen ◽

L. G. Simpson ◽

G. D. Leikauf

Keyword(s):

Epithelial Cells ◽

Protease Inhibitor ◽

Neutrophil Elastase ◽

Airway Epithelial Cells ◽

Secretory Leukocyte Protease Inhibitor ◽

Cathepsin G ◽

Dependent Manner ◽

Airway Epithelial ◽

Necrosis Factor Alpha ◽

Transcript Levels

Airway inflammation is often associated with the infiltration of activated neutrophils and subsequent protease release. Although aiding in the digestion and phagocytosis of foreign proteins and microorganisms, neutrophil proteases can indiscriminately damage healthy lung tissue. In the conducting airway, proteases, particularly neutrophil elastase, are counter-balanced by several antiproteases, including secretory leukocyte protease inhibitor (SLPI). SLPI can be produced locally by a number of cells including the airway epithelial cell. To examine the effects of neutrophil granule components on SLPI transcript levels, airway epithelial cells were treated (up to 96 h) with elastase, other proteases, or enzymes isolated from human sputum. We found that neutrophil elastase increased SLPI transcript levels in primary and transformed human airway epithelial cells in a time- and dose-dependent manner. Other neutrophil products, such as cathepsin G, myeloperoxidase, and lysozyme, had little or no effect on SLPI transcript levels. However, two nonneutrophil proteases, trypsin and pancreatic elastase, also increased SLPI transcript levels at higher doses than that required of neutrophil elastase. Two inflammatory cytokines, tumor necrosis factor-alpha and interleukin-8, produced little or no effect on SLPI transcript levels. This study demonstrates one way in which SLPI is regulated, via a protease that it inhibits, neutrophil elastase.

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The novel antiviral properties of brassicasterol against human adenovirus

Future Virology ◽

10.2217/fvl-2021-0087 ◽

2021 ◽

Author(s):

Peifeng Yu ◽

Dan Lou ◽

Lifeng Qi ◽

Zewei Chen

Keyword(s):

Dna Replication ◽

Epithelial Cells ◽

Viral Entry ◽

Human Adenovirus ◽

Airway Epithelial Cells ◽

Dependent Manner ◽

The Novel ◽

Airway Epithelial ◽

Infected Cells ◽

Dose Dependent

Aim: To investigate whether brassicasterol has inhibitory effects against adenovirus (AdV). Materials and methods: The antiviral effects of brassicasterol against AdV 3 and 7 were tested in human airway epithelial cells. Brassicasterol cytotoxicity was assessed by WST-1 assay. AdV DNA was quantified by qPCR. Results: Brassicasterol inhibited AdV 3 and 7 infection of airway epithelial cells in a dose-dependent manner. Similarly, brassicasterol also inhibited AdV 3 and 7 production in infected cells. No apparent cytotoxicity of brassicasterol was detected. Further study showed that brassicasterol inhibited AdV DNA replication, but had no impact on viral entry of cells and viral genome import to nucleus. Conclusion: Brassicasterol exerts anti-AdV effects probably through the inhibition of viral DNA replication.

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

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00526.2007 ◽

2008 ◽

Vol 294 (6) ◽

pp. L1049-L1054 ◽

Cited By ~ 34

Author(s):

K. L. Bailey ◽

J. A. Poole ◽

T. L. Mathisen ◽

T. A. Wyatt ◽

S. G. Von Essen ◽

...

Keyword(s):

Epithelial Cells ◽

Chronic Bronchitis ◽

Airway Epithelium ◽

Airway Epithelial Cells ◽

Dust Exposure ◽

Dependent Manner ◽

Airway Epithelial ◽

Toll Like Receptor ◽

Toll Like Receptor 2 ◽

Tlr2 Mrna

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 h 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. 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.

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