Effects of dexamethasone on Muc5ac mucin production by primary airway goblet cells

2005 ◽  
Vol 288 (1) ◽  
pp. L52-L60 ◽  
Author(s):  
Wenju Lu ◽  
Erik P. Lillehoj ◽  
K. Chul Kim
Keyword(s):  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Mucus Production ◽  
Mucin Production ◽  
Proinflammatory Mediators ◽  
A Cell ◽  
The Stability

Mucus hypersecretion associated with airway inflammation is reduced by glucocorticoids. Two mechanisms of glucocorticoid-mediated inhibition of mucus production have been proposed, direct inhibition of mucus production by airway epithelial cells and indirectly through inhibition of proinflammatory mediators that stimulate mucus production. In this study, we examined the effect of dexamethasone (DEX) on mRNA expression and synthesis of MUC5AC by A549 human lung adenocarcinoma cells as well as Muc5ac and total high-molecular-weight (HMW) mucins by primary rat tracheal surface epithelial (RTSE) cells. Our results showed that in primary RTSE cells, DEX 1) dose dependently suppressed Muc5ac mRNA levels, but the levels of cellular Muc5ac protein and HMW mucins were unaffected; 2) did not affect constitutive or UTP-stimulated mucin secretion; 3) enhanced the translation of Muc5ac; and 4) increased the stability of intracellular Muc5ac protein by a mechanism other than the inhibition of the proteasomal degradation. In A549 cells, however, DEX suppressed both MUC5AC mRNA levels and MUC5AC protein secretion in a dose-dependent manner. We conclude that whereas DEX inhibits the levels of Muc5ac mRNA in primary RTSE cells, the levels of Muc5ac protein remain unchanged as a consequence of increases in both translation and protein stability. Interestingly, some of the effects of DEX were opposite in a cell line.

scholarly journals Regulation of MUC5AC mucin secretion and airway surface liquid metabolism by IL-1β in human bronchial epithelia

2004 ◽  
Vol 286 (2) ◽  
pp. L320-L330 ◽  
Author(s):  
Thomas Gray ◽  
Ray Coakley ◽  
Andrew Hirsh ◽  
David Thornton ◽  
S. Kirkham ◽  
...  
Keyword(s):  
Defense Mechanism ◽  
Early Response ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Airway Surface Liquid ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Mucin Production ◽  
Inflammatory Stimuli ◽  
Surface Liquid

Mucociliary transport in the airways significantly depends on the liquid and mucin components of the airway surface liquid (ASL). The regulation of ASL water and mucin content during pathological conditions is not well understood. We hypothesized that airway epithelial mucin production and liquid transport are regulated in response to inflammatory stimuli and tested this hypothesis by investigating the effects of the pleiotropic, early-response cytokine, IL-1β, on cultured primary human bronchial epithelial and second-passage, normal human tracheo-bronchial epithelial (NHTBE) cell cultures. Fully differentiated NHTBE cultures secreted two major airway mucins, MUC5AC and MUC5B. IL-1β, in a dose- and time-dependent manner, increased the secretion of MUC5AC, but not MUC5B. MUC5AC mRNA levels were only transiently increased at 1 and 4 h after the start of IL-1β treatment and returned to control levels thereafter, even though MUC5AC mucin production remained elevated for at least 72 h. Synchronous with elevated MUC5AC secretion, ASL volume increased, its percentage of solid was reduced, and the pH/[[Formula: see text]] of the ASL was elevated. ASL volume changes reflected altered ion transport, including an upregulation of Cl- secretory currents (via CFTR and Ca2+-activated Cl- conductance) and an inhibition of epithelial sodium channel (ENaC)-mediated absorptive Na+ currents. IL-1β increased CFTR mRNA levels without affecting those for ENaC subunits. The synchronous regulation of ASL mucin and liquid metabolism triggered by IL-1β may be an important defense mechanism of the airway epithelium to enhance mucociliary clearance during airway inflammation.

Effect of defensins on interleukin-8 synthesis in airway epithelial cells

1997 ◽  
Vol 272 (5) ◽  
pp. L888-L896 ◽  
Author(s):  
S. Van Wetering ◽  
S. P. Mannesse-Lazeroms ◽  
M. A. Van Sterkenburg ◽  
M. R. Daha ◽  
J. H. Dijkman ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Neutrophil Elastase ◽  
Proteinase Inhibitor ◽  
De Novo ◽  
Tissue Injury ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Epithelial Cell Line ◽  
Mrna Levels ◽  
Airway Epithelial

Neutrophils play an important role in inflammatory processes in the lung and may cause tissue injury through, for example, release of proteinases such as neutrophil elastase. In addition to neutrophil elastase, stimulated neutrophils also release small nonenzymatic and cationic polypeptides termed defensins. The aim of the present study was to investigate whether defensins induce interleukin (IL)-8 expression in cells of the A549 lung epithelial cell line and in human primary bronchial epithelial cells (PBEC). Supernatants of defensin-treated A549 cells contained increased neutrophil chemotactic activity (16-fold) that was inhibited by antibodies against IL-8. Concurrently, within 3 and 6 h, defensins significantly increased the IL-8 levels in supernatants of both A549 cells (n = 6, P < 0.05 and P < 0.01, respectively) and PBEC (n = 4, P < 0.001 and P < 0.001, respectively). This defensin-induced increase was fully inhibited by the serine proteinase inhibitor alpha 1-proteinase inhibitor. In addition, defensins also increased IL-8 mRNA levels (12-fold); this increase was dependent on de novo mRNA synthesis and did not require protein synthesis. Furthermore, defensins did not affect IL-8 mRNA stability, indicating that the enhanced IL-8 expression was due to increased transcription. Our findings suggest that defensins, released by stimulated neutrophils, stimulate IL-8 synthesis by airway epithelial cells and thus may mediate the recruitment of additional neutrophils into the airways.

scholarly journals Ets-1 is a negative regulator of Th17 differentiation

2007 ◽  
Vol 204 (12) ◽  
pp. 2825-2835 ◽  
Author(s):  
Jacques Moisan ◽  
Roland Grenningloh ◽  
Estelle Bettelli ◽  
Mohamed Oukka ◽  
I-Cheng Ho
Keyword(s):  
Th17 Cells ◽  
Inhibitory Effect ◽  
Airway Epithelial Cells ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Mucus Production ◽  
Th Cells ◽  
Th17 Differentiation ◽  
High Level

IL-17 is a proinflammatory cytokine that plays a role in the clearance of extracellular bacteria and contributes to the pathology of many autoimmune and allergic conditions. IL-17 is produced mainly by a newly characterized subset of T helper (Th) cells termed Th17. Although the role of Th17 cells in the pathology of autoimmune diseases is well established, the transcription factors regulating the differentiation of Th17 cells remain poorly characterized. We report that Ets-1–deficient Th cells differentiated more efficiently to Th17 cells than wild-type cells. This was attributed to both low IL-2 production and increased resistance to the inhibitory effect of IL-2 on Th17 differentiation. The resistance to IL-2 suppression was caused by a defect downstream of STAT5 phosphorylation, but was not caused by a difference in the level of RORγt. Furthermore, Ets-1–deficient mice contained an abnormally high level of IL-17 transcripts in their lungs and exhibited increased mucus production by airway epithelial cells in an IL-17–dependent manner. Based on these observations, we report that Ets-1 is a negative regulator of Th17 differentiation.

scholarly journals Macrolides Inhibit Fusobacterium nucleatum-Induced MUC5AC Production in Human Airway Epithelial Cells

2013 ◽  
Vol 57 (4) ◽  
pp. 1844-1849 ◽  
Author(s):  
Kentaro Nagaoka ◽  
Katsunori Yanagihara ◽  
Yosuke Harada ◽  
Koichi Yamada ◽  
Yohei Migiyama ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Fusobacterium Nucleatum ◽  
Airway Epithelial Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Content Type ◽  
Mucin Production ◽  
Tract Infections

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

scholarly journals Neutrophil elastase increasesMUC5ACmRNA and protein expression in respiratory epithelial cells

1999 ◽  
Vol 276 (5) ◽  
pp. L835-L843 ◽  
Author(s):  
Judith A. Voynow ◽  
Lisa Rosenthal Young ◽  
Yiqiong Wang ◽  
Teresa Horger ◽  
Mary C. Rose ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Epithelial Cells ◽  
Serine Protease ◽  
Neutrophil Elastase ◽  
A549 Cells ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Mucin Production ◽  
Mucin Gene

Chronic neutrophil-predominant inflammation and hypersecretion of mucus are common pathophysiological features of cystic fibrosis, chronic bronchitis, and viral- or pollution-triggered asthma. Neutrophils release elastase, a serine protease, that causes increased mucin production and secretion. The molecular mechanisms of elastase-induced mucin production are unknown. We hypothesized that as part of this mechanism, elastase upregulates expression of a major respiratory mucin gene, MUC5AC. A549, a human lung carcinoma cell line that expresses MUC5AC mRNA and protein, and normal human bronchial epithelial cells in an air-liquid interface culture were stimulated with neutrophil elastase. Neutrophil elastase increased MUC5AC mRNA levels in a time-dependent manner in both cell culture systems. Neutrophil elastase treatment also increased MUC5AC protein levels in A549 cells. The mechanism of MUC5AC gene regulation by elastase was determined in A549 cells. The induction of MUC5AC gene expression required serine protease activity; other classes of proteases had no effect on MUC5AC gene expression. Neutrophil elastase increased MUC5AC mRNA levels by enhancing mRNA stability. This is the first report of mucin gene regulation by this mechanism.

scholarly journals Targeting a central feature of asthma using a cell type-selective IL-13-responsive enhancer

2021 ◽  
Author(s):  
Kyung Duk Koh ◽  
Luke R Bonser ◽  
Walter L Eckalbar ◽  
Jiangshan Shen ◽  
Ofer Yizhar-Barnea ◽  
...  
Keyword(s):  
Regulatory Elements ◽  
Airway Epithelial Cells ◽  
Secretory Cells ◽  
Central Feature ◽  
Airway Epithelial ◽  
Cell Type ◽  
Mucin Production ◽  
Genome Wide ◽  
A Cell

IL-13 is a central mediator of asthma. Here, we used genome-wide approaches to characterize genes and regulatory elements modulated by IL-13 and other asthma-associated cytokines in airway epithelial cells and showed how they can be used for therapeutic purposes. Using bulk and single cell RNA-seq, we found distinctive responses to IL-13, IL-17, and interferons in human bronchial epithelial basal, ciliated, and secretory cells. H3K27ac ChIP-seq revealed that IL-13 had widespread effects on regulatory elements. Detailed characterization of an enhancer of SPDEF, a transcription factor required for pathologic mucin production, revealed that STAT6 and KLF5 binding sites cooperate to drive IL-13-dependent transcription selectively in secretory cells. Using this enhancer to drive CRISPRi and knockdown either SPDEF or the mucin MUC5AC showed the potential use of this approach for asthma therapeutics. This work identifies numerous genes and regulatory elements involved in cell type-selective cytokine responses and showcases their use for therapeutic purposes.

scholarly journals PPARγ inhibits airway epithelial cell inflammatory response through a MUC1-dependent mechanism

2012 ◽  
Vol 302 (7) ◽  
pp. L679-L687 ◽  
Author(s):  
Yong Sung Park ◽  
Erik P. Lillehoj ◽  
Kosuke Kato ◽  
Choon Sik Park ◽  
Kwang Chul Kim
Keyword(s):  
Epithelial Cells ◽  
Culture Media ◽  
A549 Cells ◽  
Luciferase Reporter ◽  
Muc1 Expression ◽  
Mrna Levels ◽  
Airway Epithelial ◽  
Pparγ Agonist ◽  
Tnf Α ◽  
Primary Mouse

This study was conducted to examine the relationship between the peroxisome proliferator-associated receptor-γ (PPARγ) and MUC1 mucin, two anti-inflammatory molecules expressed in the airways. Treatment of A549 lung epithelial cells or primary mouse tracheal surface epithelial (MTSE) cells with phorbol 12-myristate 13-acetate (PMA) increased the levels of tumor necrosis factor (TNF)-α in cell culture media compared with cells treated with vehicle alone. Overexpression of MUC1 in A549 cells decreased PMA-stimulated TNF-α levels, whereas deficiency of Muc1 expression in MTSE cells from Muc1 null mice increased PMA-induced TNF-α levels. Treatment of A549 or MTSE cells with the PPARγ agonist troglitazone (TGN) blocked the ability of PMA to stimulate TNF-α levels. However, the effect of TGN required the presence of MUC1/Muc1, since no differences in TNF-α levels were seen between PMA and PMA plus TGN in MUC1/Muc1-deficient cells. Similarly, whereas TGN decreased interleukin-8 (IL-8) levels in culture media of MUC1-expressing A549 cells treated with Pseudomonas aeruginosa strain K (PAK), no differences in IL-8 levels were seen between PAK and PAK plus TGN in MUC1-nonexpressing cells. EMSA confirmed the presence of a PPARγ-binding element in the MUC1 gene promoter. Finally, TGN treatment of A549 cells increased MUC1 promoter activity measured using a MUC1-luciferase reporter gene, augmented MUC1 mRNA levels by quantitative RT-PCR, and enhanced MUC1 protein expression by Western blot analysis. These combined data are consistent with the hypothesis that PPARγ stimulates MUC1/Muc1 expression, thereby blocking PMA/PAK-induced TNF-α/IL-8 production by airway epithelial cells.

scholarly journals Anti-Inflammatory Properties of Fructo-Oligosaccharides in a Calf Lung Infection Model and in Mannheimia haemolytica-Infected Airway Epithelial Cells

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3514
Author(s):  
Yang Cai ◽  
Myrthe S. Gilbert ◽  
Walter J. J. Gerrits ◽  
Gert Folkerts ◽  
Saskia Braber
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Mannheimia Haemolytica ◽  
Epithelial Barrier ◽  
Infection Model ◽  
Airway Epithelial ◽  
Clinical Scores ◽  
Lung Infections ◽  
Anti Inflammatory

Emerging antimicrobial-resistant pathogens highlight the importance of developing novel interventions. Here, we investigated the anti-inflammatory properties of Fructo-oligosaccharides (FOS) in calf lung infections and in airway epithelial cells stimulated with pathogens, and/or bacterial components. During a natural exposure, 100 male calves were fed milk replacer with or without FOS for 8 weeks. Then, immune parameters and cytokine/chemokine levels in the bronchoalveolar lavage fluid (BALF) and blood were measured, and clinical scores were investigated. Calf primary bronchial epithelial cells (PBECs) and human airway epithelial cells (A549) were treated with Mannheimia haemolytica, lipopolysaccharides (LPS), and/or flagellin, with or without FOS pretreatment. Thereafter, the cytokine/chemokine levels and epithelial barrier function were examined. Relative to the control (naturally occurring lung infections), FOS-fed calves had greater macrophage numbers in BALF and lower interleukin (IL)-8, IL-6, and IL-1β concentrations in the BALF and blood. However, FOS did not affect the clinical scores. At slaughter, FOS-fed calves had a lower severity of lung lesions compared to the control. Ex vivo, FOS prevented M. haemolytica-induced epithelial barrier dysfunction. Moreover, FOS reduced M. haemolytica- and flagellin-induced (but not LPS-induced) IL-8, TNF-α, and IL-6 release in PBECs and A549 cells. Overall, FOS had anti-inflammatory properties during the natural incidence of lung infections but had no effects on clinical symptoms.

Hypoxia induces hexokinase II gene expression in human lung cell line A549

2000 ◽  
Vol 278 (2) ◽  
pp. L407-L416 ◽  
Author(s):  
Suzette R. Riddle ◽  
Aftab Ahmad ◽  
Shama Ahmad ◽  
Samir S. Deeb ◽  
Mari Malkki ◽  
...  
Keyword(s):  
Luciferase Activity ◽  
Regulatory Region ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Luciferase Reporter ◽  
Airway Epithelial ◽  
Hexokinase Ii ◽  
Pulmonary Cells ◽  
Promoter Construct ◽  
Human Lung Cell Line

During adaptation to hypoxic and hyperoxic conditions, the genes involved in glucose metabolism are upregulated. To probe involvement of the transcription factor hypoxia-induced factor-1 (HIF-1) in hexokinase (HK) II expression in human pulmonary cells, A549 cells and small-airway epithelial cells (SAECs) were exposed to stimuli such as hypoxia, deferoxamine (DFO), and metal ions. The largest increase in HK-II (20-fold for mRNA and 2.5-fold for enzymatic activity) was observed in A549 cells when exposed to DFO. All stimuli selectively increased the 5.5-kb rather than 4-kb transcript in A549 cells. Cycloheximide and actinomycin D inhibited these responses. In addition, cells were transfected with luciferase reporter constructs driven by the full-length HK-II 5′-regulatory region (4.0 kb) or various deletions of that region. A549 cells transfected with the 4.0-kb construct and exposed to hypoxia or DFO increased their luciferase activity 7- and 10-fold, respectively, indicating that HK-II induction is, at least in part, due to increased gene transcription. Sixty percent of the inducible activity of the 4.0-kb construct was shown to reside within the proximal 0.5 kb. Additionally, cotransfection with a stable HIF-1 mutant and the 4.0-kb promoter construct resulted in increased luciferase activity under normoxic conditions. These results strongly suggest that HK-II is selectively regulated in pulmonary cells by a HIF-1-dependent mechanism.

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