scholarly journals Attenuated lncRNA NKILA Enhances the Secretory Function of Airway Epithelial Cells Stimulated by Mycoplasma pneumoniae via NF-κB

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fengxia Zhang ◽  
Jiamin Zhang ◽  
Feng Liu ◽  
Yao Zhou ◽  
Yun Guo ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mycoplasma Pneumoniae ◽  
Noncoding Rna ◽  
Nuclear Translocation ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Regulatory Function ◽  
Airway Epithelial ◽  
Secretory Function ◽  
Tnf Α

The secretory function of airway epithelial cells is important in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). To investigate the regulatory function of NKILA (nuclear factor-κB (NF-κB) interacting long noncoding RNA (lncRNA)) in MPP, we first detected NKILA as well as the concentration of interleukin 8 (IL-8) and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid of children with MPP. Then, NKILA was knocked down in epithelial cells to investigate its effect on their secretory function. The results suggested that NKILA was downregulated in children with MPP, while IL-8 and TNF-α levels increased. Knockdown of NKILA in vitro promoted the inflammatory effects of Mycoplasma pneumoniae (MP) in epithelial A549 and BEAS-2B cells. Knockdown of NKILA promoted inhibitor of κBα (IκBα) phosphorylation and degradation, and NF-κB p65 nuclear translocation. Furthermore, RNA immunoprecipitation showed that NKILA could physically bind to IκBα in MP-treated A549 cells. Collectively, our data demonstrated that attenuation of NKILA enhances the effects of MP-stimulated secretory functions of epithelial cells via regulation of NF-κB signaling.

scholarly journals Incomplete Regulation of NF-κB by IκBα during Respiratory Syncytial Virus Infection in A549 Cells

1999 ◽  
Vol 73 (5) ◽  
pp. 4502-4507 ◽  
Author(s):  
Michael A. Fiedler ◽  
Kara Wernke-Dollries
Keyword(s):  
Respiratory Syncytial Virus ◽  
Epithelial Cells ◽  
A549 Cells ◽  
Inhibitory Effect ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Rsv Infection ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) infection of airway epithelial cells results in persistent NF-κB activation and NF-κB-mediated interleukin-8 production. Previous studies in airway epithelial cells demonstrated that tumor necrosis factor alpha (TNF-α)-induced NF-κB activation is transient due to regulation by IκBα. However, during RSV infection, IκBα has only a partial inhibitory effect on NF-κB activation. Studies presented here demonstrate that neither increased IκBα production which occurs as a result of RSV-induced NF-κB activation nor inhibition of proteasome-mediated IκBα degradation results in a reversal of RSV-induced NF-κB activation. Thus, while manipulation of IκBα results in reversal of TNF-α-induced NF-κB activation, manipulation of IκBα does not result in a reversal of RSV-induced NF-κB activation.

scholarly journals The uptake of a Klebsiella pneumoniae capsule polysaccharide mutant triggers an inflammatory response by human airway epithelial cells

Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 555-566 ◽  
Author(s):  
Verónica Regueiro ◽  
Miguel A. Campos ◽  
Jaume Pons ◽  
Sebastián Albertí ◽  
José A. Bengoechea
Keyword(s):  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Inflammatory Response ◽  
Nuclear Translocation ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Wild Type ◽  
Cellular Activation ◽  
Epithelial Cell Surface

The means by which airway epithelial cells sense a bacterial infection and which intracellular signalling pathways are activated upon infection are poorly understood. A549 cells and human primary airway cells (NHBE) were used to investigate the response to infection with Klebsiella pneumoniae. Infection of A549 and NHBE with K. pneumoniae 52K10, a capsule polysaccharide (CPS) mutant, increased the surface levels of ICAM-1 and caused the release of IL-8. By contrast, the wild-type strain did not elicit these responses. Consistent with a functional role for these responses, there was a correlation between ICAM-1 levels and the number of adherent leukocytes on the epithelial cell surface. In addition, treatment of neutrophils with IL-8 enhanced their ability to kill K. pneumoniae. Strain 52K10 was internalized by A549 cells more efficiently than the wild-type, and when infections with 52K10 were performed in the presence of cytochalasin D the inflammatory response was abrogated. These findings suggest that cellular activation is mediated by bacterial internalization and that CPS prevents the activation through the blockage of bacterial adhesion and uptake. Collectively, the results indicate that bacterial internalization by airway epithelial cells could be the triggering signal for the activation of the innate immune system of the airway. Infection of A549 cells by 52K10 was shown to trigger the nuclear translocation of NF-κB. Evidence is presented showing that 52K10 activated IL-8 production through Toll-like receptor (TLR) 2 and TLR4 pathways and that A549 cells could use soluble CD14 as TLR co-receptor.

scholarly journals Ozone effect on inflammatory and proteomic profile of human macrophages and airway epithelial cells

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
L Falcone ◽  
E Aruffo ◽  
P Di Carlo ◽  
P Del Boccio ◽  
M C Cufaro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Air Pollution ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Urban Areas ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Proteomics Analysis ◽  
Human Macrophages ◽  
Tnf Α

Abstract Background Reactive oxygen species (ROS) and oxidative stress in the respiratory system are involved in lung inflammation and tumorigenesis. Ozone (O3) is one of the main components of air pollution in urban areas able to act as strong pro-oxidant agent, however its effects on human health is still poorly investigated. In this study the effect of O3 has been evaluated in THP-1 monocytes differentiated into macrophages with PMA and in HBEpC (primary human bronchial epithelial) cells, two model systems for in vitro studies and translational research. Methods Cell viability, ROS and pro-inflammatory cytokines like interleukin-8(IL-8) and tumor necrosis factor(TNF-α) have been tested in the above-mentioned cell lines not exposed to any kind of pollution (basal condition-b.c.) or exposed to O3 at a concentration of 120 ppb. In HBEpC a labelfree shotgun proteomics analysis has been also performed in the same conditions. Results Ozone significantly increased the production of IL-8 and TNF-α in THP-1 whereas no changes were shown in HBEpC. In both cell lines lipopolysaccharide(LPS) caused an increase of IL-8 and TNF-α production in b.c. and O3 treatment potentiated this effect. Ozone exposure increased ROS formation in a time dependent manner in both cell lines and in THP-1 cells a decrease in catalase activity was also shown. Finally, according to these data, functional proteomics analysis revealed that in HBEpC exposure to O3 many differential proteins are related to oxidative stress and inflammation. Conclusions Our results indicate that O3, at levels that can be reached in urban areas, causes an increase of pro-inflammatory agents either per se or potentiating the effect of immune response stimulators in cell models of human macrophages and human airway epithelial cells. Interestingly, the proteomic analysis showed that besides the dysregulated proteins, O3 induced the expression of AKR1D1 and AKR1B10, proteins recognized to play a significant role in cancer development. Key messages This study adds new pieces of information on the association between O3 exposure and detrimental effects on respiratory system. This study suggests the need for further research on the mechanisms involved and for a continued monitoring/re-evaluation of air pollution standards aimed at safeguarding human health.

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.

scholarly journals LncRNA HOTAIR Increases Inflammatory Responses by Activating NF-κB Pathway in LPS-Induced Acute Lung Injury

2020 ◽  
Author(s):  
XiaoMei Huang ◽  
ZeXun Mo ◽  
YuJun Li ◽  
Hua He ◽  
KangWei Wang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Noncoding Rna ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
A549 Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Qrt Pcr ◽  
Tnf Α ◽  
Lncrna Hotair

Abstract Background Nuclear factor kappa-B (NF-κB) activation increased the expression of cytokines and further lead to lung injury was considered the main mechanism of acute lung injury (ALI). Here, we focus on exploring the potential regulatory mechanism between long noncoding RNA (LncRNA) HOX transcript antisense RNA (HOTAIR) and NF-κB on LPS-induced ALI. Methods A549 cells were then divided into 4 groups: HOTAIR group, NC group, si-HOTAIR group and si-NC group. These 4 groups were then treated with 1μg/mL lipopolysaccharides (LPS) or without LPS at 37°C for 24 h. The expression level of cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6) and LncRNA HOTAIR were evaluated by quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and Enzyme-linked immunosorbent assay (ELISA). Western Blot analysis was adopted for evaluating the level of p-IκBα/IκBα and p-p65/p65. Nuclear translocation of p65 was observed by immunofluorescence staining. Results qRT-PCR and ELISA assay showed that the expression of cytokines (IL-1β, IL-6 and TNF-α) and inflammatory gene HOTAIR was remarkably increased with LPS treatment (p < 0.01). Over-expression of HOTAIR significantly increased the expression of cytokines (including IL-1β, IL-6 and TNF-α) and NF-κB pathway associated proteins (including p-IκBα/IκBα and p-p65/p65), while knockdown of HOTAIR had the opposite effect (p < 0.01). The immunofluorescence assay showed that the level of p65 in the nucleus was significantly higher in the HOTAIR group and significantly lowers in the si-HOTAIR group (p < 0.01). Conclusion HOTAIR may play a pro-inflammatory response through NF-κB pathway in LPS-induced ALI, which may provide a perspective for further understanding the pathogenic mechanism of ALI.

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.

Inhibition of TNF-α-Induced MUC5AC Mucin Gene Expression and Production by Wogonin Through the Inactivation of NF-κB Signaling in Airway Epithelial Cells

2013 ◽  
Vol 28 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Md. Asaduzzaman Sikder ◽  
Hyun Jae Lee ◽  
Md. Zakaria Mia ◽  
Su Hyun Park ◽  
Jiho Ryu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Mucin Gene ◽  
Tnf Α

Pseudomonas aeruginosapyocyanin directly oxidizes glutathione and decreases its levels in airway epithelial cells

2004 ◽  
Vol 287 (1) ◽  
pp. L94-L103 ◽  
Author(s):  
Yunxia Q. O'Malley ◽  
Krzysztof J. Reszka ◽  
Douglas R. Spitz ◽  
Gerene M. Denning ◽  
Bradley E. Britigan
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Culture Media ◽  
Alveolar Epithelial Cell ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Alternative Source ◽  
Cell Functions

Production of pyocyanin enhances Pseudomonas aeruginosa virulence. Many of pyocyanin's in vitro and in vivo cytotoxic effects on human cells appear to result from its ability to redox cycle. Pyocyanin directly accepts electrons from NADH or NADPH with subsequent electron transfer to oxygen, generating reactive oxygen species. Reduced glutathione (GSH) is an important cellular antioxidant, and it contributes to the regulation of redox-sensitive signaling systems. Using the human bronchial epithelial (HBE) and the A549 human type II alveolar epithelial cell lines, we tested the hypothesis that pyocyanin can deplete airway epithelial cells of GSH. Incubation of both cell types with pyocyanin led to a concentration-dependent loss of cellular GSH (up to 50%) and an increase in oxidized GSH (GSSG) in the HBE, but not A549 cells, at 24 h. An increase in total GSH, mostly as GSSG, was detected in the culture media, suggesting export of GSH or GSSG from the pyocyanin-exposed cells. Loss of GSH could be due to pyocyanin-induced H2O2formation. However, overexpression of catalase only partially prevented the pyocyanin-mediated decline in cellular GSH. Cell-free electron paramagnetic resonance studies revealed that pyocyanin directly oxidizes GSH, forming pyocyanin free radical and O2−·. Pyocyanin oxidized other thiol-containing compounds, cysteine and N-acetyl-cysteine, but not methionine. Thus GSH may enhance pyocyanin-induced cytotoxicity by functioning as an alternative source of reducing equivalents for pyocyanin redox cycling. Pyocyanin-mediated alterations in cellular GSH may alter epithelial cell functions by modulating redox sensitive signaling events.

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