scholarly journals Necrosis of Lung Epithelial Cells during Infection withMycobacterium tuberculosis Is Preceded by Cell Permeation

2000 ◽  
Vol 68 (11) ◽  
pp. 6300-6310 ◽  
Author(s):  
Karen M. Dobos ◽  
Ellen A. Spotts ◽  
Frederick D. Quinn ◽  
C. Harold King
Keyword(s):  
Epithelial Cells ◽  
A549 Cell ◽  
Cell Monolayer ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Infected Cells ◽  
Cellular Necrosis ◽  
Ldh Release

ABSTRACT Mycobacterium tuberculosis establishes infection, progresses towards disease, and is transmitted from the alveolus of the lung. However, the role of the alveolar epithelium in any of these pathogenic processes of tuberculosis is unclear. In this study, lung epithelial cells (A549) were used as a model in which to examine cytotoxicity during infection with either virulent or avirulent mycobacteria in order to further establish the role of the lung epithelium during tuberculosis. Infection of A549 cells with M. tuberculosis strains Erdman and CDC1551 demonstrated significant cell monolayer clearing, whereas infection with eitherMycobacterium bovis BCG or Mycobacterium smegmatis LR222 did not. Clearing of M. tuberculosis-infected A549 cells correlated to necrosis, not apoptosis. Treatment of M. tuberculosis-infected A549 cells with streptomycin, but not cycloheximide, demonstrated a significant reduction in the necrosis of A549 cell monolayers. This mycobacterium-induced A549 necrosis did not correlate to higher levels of intracellular or extracellular growth by the mycobacteria during infection. Staining of infected cells with propidium iodide demonstrated that M. tuberculosis induced increased permeation of A549 cell membranes within 24 h postinfection. Quantitation of lactate dehydrogenase (LDH) release from infected cells further demonstrated that cell permeation was specific to M. tuberculosis infection and correlated to A549 cellular necrosis. Inactivated M. tuberculosis or its subcellular fractions did not result in A549 necrosis or LDH release. These studies demonstrate that lung epithelial cell cytotoxicity is specific to infection by virulent mycobacteria and is caused by cellular necrosis. This necrosis is not a direct correlate of mycobacterial growth or of the expression of host cell factors, but is preceded by permeation of the A549 cell membrane and requires infection with live bacilli.

scholarly journals Puerarin Inhibits Ferroptosis and Inflammation of Lung Injury Caused by Sepsis in LPS Induced Lung Epithelial Cells

2021 ◽  
Author(s):  
Baiye Xu ◽  
Haidao Wang ◽  
Zhen Chen
Keyword(s):  
Epithelial Cells ◽  
Lung Injury ◽  
Cell Viability ◽  
A549 Cell ◽  
A549 Cells ◽  
Total Iron ◽  
Lung Epithelial Cells ◽  
Expression Level ◽  
Lung Epithelial ◽  
Related Proteins

Abstract Background: Ferroptosis is a new type of programmed cell death, which plays an important role in lung injury caused by sepsis. Studies have reported that Puerarin (Pue) can treat lung injury caused by sepsis in children, but whether it plays a role by regulating iron death has not been reported.Methods: LPS induced human alveolar epithelial cell A549 to form a model of lung injury caused by sepsis. MTT detected the effect of Pue on A549 cell viability and the effect of Pue on LPS-induced A549 cell viability. The effects of Pue on LPS-induced inflammatory cytokines TNF-α, IL-8, IL-1β in A549 cells were determined by ELISA assay. The expression level of MDA was detected by TBARS colorimetric quantitative detection kit. GSH kit was used to detect the expression of GSH in cells. The iron kit detected the total iron level and the expression level of ferric divalent ions in the cells. DCFH-DA fluorescent probe was used to detect ROS levels. Western blot was used to detect the expression of ferroptosis-related proteins in cells. Results: Pue alleviated LPS-induced injury and inflammatory response in A549 cells, and Pue reduced the expression of ROS, MDA and GSH in LPS-induced A549 cells. In addition, Pue reduced total iron levels and ferrous ion levels in LPS-induced A549 cells, and decreased the expression of iron ferroptosis-related proteins. Conclusion: Puerarin inhibited ferroptosis and inflammation of lung injury caused by sepsis in children in LPS induced lung epithelial cells.

scholarly journals Puerarin Inhibits Ferroptosis and Inflammation of Lung Injury Caused by Sepsis in LPS Induced Lung Epithelial Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Baiye Xu ◽  
Haidao Wang ◽  
Zhen Chen
Keyword(s):  
Epithelial Cells ◽  
Lung Injury ◽  
Cell Viability ◽  
A549 Cell ◽  
A549 Cells ◽  
Total Iron ◽  
Lung Epithelial Cells ◽  
Expression Level ◽  
Lung Epithelial ◽  
Related Proteins

Background: Ferroptosis is a new type of programmed cell death, which plays an important role in lung injury caused by sepsis. Studies have reported that Puerarin (Pue) can treat lung injury caused by sepsis in children, but whether it plays a role by regulating iron death has not been reported.Methods: LPS induced human alveolar epithelial cell A549 to form a model of lung injury caused by sepsis. MTT detected the effect of Pue on A549 cell viability and the effect of Pue on LPS-induced A549 cell viability. The effects of Pue on LPS-induced inflammatory cytokines TNF-α, IL-8, IL-1β in A549 cells were determined by ELISA assay. The expression level of MDA was detected by TBARS colorimetric quantitative detection kit. GSH kit was used to detect the expression of GSH in cells. The iron kit detected the total iron level and the expression level of ferric divalent ions in the cells. DCFH-DA fluorescent probe was used to detect ROS levels. Western blot was used to detect the expression of ferroptosis-related proteins in cells.Results: Pue alleviated LPS-induced injury and inflammatory response in A549 cells, and Pue reduced the expression of ROS, MDA and GSH in LPS-induced A549 cells. In addition, Pue reduced total iron levels and ferrous ion levels in LPS-induced A549 cells, and decreased the expression of iron ferroptosis-related proteins.Conclusion: Puerarin inhibited ferroptosis and inflammation of lung injury caused by sepsis in children in LPS induced lung epithelial cells.

scholarly journals Transcriptomic Signatures of Airway Epithelium Infected With SARS-CoV-2: A Balance Between Anti-infection and Virus Load

2021 ◽  
Vol 9 ◽  
Author(s):  
Lingzhang Meng ◽  
Houji Qin ◽  
Jingjie Zhao ◽  
Siyuan He ◽  
Qiuju Wei ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Differentially Expressed Gene ◽  
High Viral Load ◽  
Lung Epithelial Cells ◽  
Therapeutic Drugs ◽  
Lung Epithelial ◽  
Infected Cells ◽  
Transcriptome Expression ◽  
The Relationship

COVID-19 pneumonia requires effective medical therapies. However, it is a challenge to find therapeutic drugs that not only inhibit viral replication, but also inhibit the accompanying cytokine storm and maintain an appropriate immune response. In this study, the effects of SARS-CoV-2 on gene expression in lung epithelial cells from patients with COVID-19 were systematically evaluated with bioinformatics analysis methods. Transcriptome expression specific to bystander (exposed but uninfected) and infected cells were found, and the vital pathways were identified by conducting differentially expressed gene analysis regarding the relationship between gene signatures of COVID-19 infection and disease severity. We found that a high viral load did not necessarily imply a low response of epithelial cells or a poor disease convalescence. The ability to distinguish the role of virus-correlated genes facilitates the development of potential new medicines and therapies for COVID-19 infection.

scholarly journals Amphiregulin induces interleukin-8 production and cell proliferation in lung epithelial cells through PI3K-Akt/ ERK pathways

2021 ◽  
Vol 19 ◽  
pp. 205873922199820
Author(s):  
Fangfang Yang ◽  
Wei Xu ◽  
Yanli Pei
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
A549 Cells ◽  
Specific Inhibitor ◽  
Neutralizing Antibody ◽  
Lung Epithelial Cells ◽  
Signal Pathways ◽  
Lung Epithelial ◽  
Epidermal Growth

Amphiregulin (AR), belongs to the epidermal growth factor (EGF) family, is able to induce a series of pathological and physiological responses by binding and activating epidermal growth factor receptor (EGFR). Interleukin-8 (IL-8) or CXCL8, a pro-inflammatory chemokine, has been suggested to be involved in tumor cell proliferation and inflammatory microenvironment via transactivation of the EGFR. However, whether there is a crosstalk between AR with IL-8 during inflammatory response remain to be fully understood. The current study was designed to investigate the possible mechanism of the interactions between AR and IL-8 production in human lung epithelial cells in vitro. Lung epithelial A549 cells were stimulated with lipopolysaccharide (LPS) to generate ALI model. LPS-induced AR and IL-8 production by A549 cells was measured by real-time PCR, Western Blot, and ELISA. The AR neutralizing antibody, PI3K specific inhibitor LY294002, JNK specific inhibitor SP60012, ERK specific inhibitor PD98089, and p38 inhibitor SB203580 were used to investigate the role of these signal pathways in LPS-induced cell proliferation, AR and IL-8 expression. LPS could induce AR through PI3K/Akt and ERK signal pathways. Furthermore, LPS induced AR promoted the production of IL-8 requires activation of EGFR, PI3K/Akt, and ERK signal pathways. The neutralizing antibody to AR prevented production of IL-8 induced by LPS. Treatment with Erlotinib, PI3K inhibitors, ERK inhibitor significantly inhibited AR-induced IL-8 production and cell proliferation. Our data indicate that a distinct role of EGFR–PI3K–Akt/ERK pathway as a bridge of interaction between AR and IL-8 production, as one of potential mechanisms to regulate inflammation and cell proliferation in human lung epithelial cells.

MC1568 inhibits HDAC6/8 activity and influenza A virus replication in lung epithelial cells: role of Hsp90 acetylation

2016 ◽  
Vol 8 (17) ◽  
pp. 2017-2031 ◽  
Author(s):  
Simona Panella ◽  
Maria Elena Marcocci ◽  
Ignacio Celestino ◽  
Sergio Valente ◽  
Clemens Zwergel ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Lung Epithelial Cells ◽  
Lung Epithelial

Ionizing radiation enhances matrix metalloproteinase-2 production in human lung epithelial cells

2001 ◽  
Vol 280 (1) ◽  
pp. L30-L38 ◽  
Author(s):  
Jun Araya ◽  
Muneharu Maruyama ◽  
Kazuhiko Sassa ◽  
Tadashi Fujita ◽  
Ryuji Hayashi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ionizing Radiation ◽  
Basement Membrane ◽  
Lung Injury ◽  
Human Lung ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Radiation Induced ◽  
Human Lung Epithelial Cells

Radiation pneumonitis is a major complication of radiation therapy. However, the detailed cellular mechanisms have not been clearly defined. Based on the recognition that basement membrane disruption occurs in acute lung injury and that matrix metalloproteinase (MMP)-2 can degrade type IV collagen, one of the major components of the basement membrane, we hypothesized that ionizing radiation would modulate MMP-2 production in human lung epithelial cells. To evaluate this, the modulation of MMP-2 with irradiation was investigated in normal human bronchial epithelial cells as well as in A549 cells. We measured the activity of MMP-2 in the conditioned medium with zymography and the MMP-2 mRNA level with RT-PCR. Both of these cells constitutively expressed 72-kDa gelatinolytic activity, corresponding to MMP-2, and exposure to radiation increased this activity. Consistent with the data of zymography, ionizing radiation increased the level of MMP-2 mRNA. This radiation-induced increase in MMP-2 expression was mediated via p53 because the p53 antisense oligonucleotide abolished the increase in MMP-2 activity as well as the accumulation of p53 after irradiation in A549 cells. These results indicate that MMP-2 expression by human lung epithelial cells is involved in radiation-induced lung injury.

scholarly journals HIV-1 Productively Infects and Integrates in Bronchial Epithelial Cells

2021 ◽  
Vol 10 ◽  
Author(s):  
Dinesh Devadoss ◽  
Shashi P. Singh ◽  
Arpan Acharya ◽  
Kieu Chinh Do ◽  
Palsamy Periyasamy ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Lung Epithelial Cells ◽  
People Living With Hiv ◽  
Sequencing Analysis ◽  
Hiv Reservoirs ◽  
Bronchial Epithelial ◽  
Lung Epithelial ◽  
Hiv 1

BackgroundThe role of lung epithelial cells in HIV-1-related lung comorbidities remains unclear, and the major hurdle in curing HIV is the persistence of latent HIV reservoirs in people living with HIV (PLWH). The advent of combined antiretroviral therapy has considerably increased the life span; however, the incidence of chronic lung diseases is significantly higher among PLWH. Lung epithelial cells orchestrate the respiratory immune responses and whether these cells are productively infected by HIV-1 is debatable.MethodsNormal human bronchial epithelial cells (NHBEs) grown on air–liquid interface were infected with X4-tropic HIV-1LAV and examined for latency using latency-reversing agents (LRAs). The role of CD4 and CXCR4 HIV coreceptors in NHBEs were tested, and DNA sequencing analysis was used to analyze the genomic integration of HIV proviral genes, Alu-HIVgag-pol, HIV-nef, and HIV-LTR. Lung epithelial sections from HIV-infected humans and SHIV-infected macaques were analyzed by FISH for HIV-gag-pol RNA and epithelial cell-specific immunostaining.Results and DiscussionNHBEs express CD4 and CXCR4 at higher levels than A549 cells. NHBEs are infected with HIV-1 basolaterally, but not apically, by X4-tropic HIV-1LAV in a CXCR4/CD4-dependent manner leading to HIV-p24 antigen production; however, NHBEs are induced to express CCR5 by IL-13 treatment. In the presence of cART, HIV-1 induces latency and integration of HIV provirus in the cellular DNA, which is rescued by the LRAs (endotoxin/vorinostat). Furthermore, lung epithelial cells from HIV-infected humans and SHIV-infected macaques contain HIV-specific RNA transcripts. Thus, lung epithelial cells are targeted by HIV-1 and could serve as potential HIV reservoirs that may contribute to the respiratory comorbidities in PLWH.

scholarly journals TRIM28 regulates SARS-CoV-2 cell entry by targeting ACE2

2020 ◽  
Author(s):  
Yinfang Wang ◽  
Yingzhe Fan ◽  
Yitong Huang ◽  
Tao Du ◽  
Zongjun Liu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nk Cells ◽  
Interleukin 2 ◽  
A549 Cells ◽  
Endogenous Retrovirus ◽  
Alveolar Epithelial Cells ◽  
Cell Entry ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Ifn Γ

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), it binds to angiotensin-converting enzyme 2 (ACE2) to enter into human cells. The expression level of ACE2 potentially determine the susceptibility and severity of COVID-19, it is thus of importance to understand the regulatory mechanism of ACE2 expression. Tripartite motif containing 28 (TRIM28) is known to be involved in multiple processes including antiviral restriction, endogenous retrovirus latency and immune response, it is recently reported to be co-expressed with SARS-CoV-2 receptor in type II pneumocytes; however, the roles of TRIM28 in ACE2 expression and SARS-CoV-2 cell entry remain unclear. This study showed that knockdown of TRIM28 induces ACE2 expression and increases pseudotyped SARS-CoV-2 cell entry of A549 cells and primary pulmonary alveolar epithelial cells (PAEpiCs). In a co-culture model of NK cells and lung epithelial cells, our results demonstrated that NK cells inhibit TRIM28 and promote ACE2 expression in lung epithelial cells, which was partially reversed by depletion of interleukin-2 and blocking of granzyme B in the co-culture medium. Furthermore, TRIM28 knockdown enhanced interferon-γ (IFN-γ)-induced ACE2 expression through a mechanism involving upregulating IFN-γ receptor 2 (IFNGR2) in both A549 and PAEpiCs. Importantly, the upregulated ACE2 induced by TRIM28 knockdown and co-culture of NK cells was partially reversed by dexamethasone in A549 cells but not PAEpiCs. Our study identified TRIM28 as a novel regulator of ACE2 expression and SARS-CoV-2 cell entry.

scholarly journals Role of protein kinase C in cytokine secretion by lung epithelial cells during infection withParacoccidioides brasiliensis

2015 ◽  
Vol 73 (7) ◽  
pp. ftv045 ◽  
Author(s):  
Cristiane Alcantara ◽  
Paloma Korehisa Maza ◽  
Bianca Carla Silva Campitelli Barros ◽  
Erika Suzuki
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Cytokine Secretion ◽  
Kinase C ◽  
Lung Epithelial

Expression and role of E- and P-cadherin adhesion molecules in embryonic histogenesis. I. Lung epithelial morphogenesis

Development ◽  
1989 ◽  
Vol 105 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Y. Hirai ◽  
A. Nose ◽  
S. Kobayashi ◽  
M. Takeichi
Keyword(s):  
Monoclonal Antibody ◽  
Cell Adhesion ◽  
Epithelial Cells ◽  
Adhesion Molecules ◽  
Lung Epithelial Cells ◽  
Early Developmental Stage ◽  
Subtle Effect ◽  
Lung Epithelial ◽  
Cell Cell

The role of Ca2+-dependent cell-cell adhesion molecules, E- and P-cadherins, in the histogenesis of mouse embryonic lung was studied. All epithelial cells of the lung express both E- and P-cadherin at the early developmental stage. P-cadherin, however, gradually disappears during development, initially from the main bronchi and eventually from all epithelial cells. When a monoclonal antibody to E-cadherin (ECCD-1) was added to monolayer cultures of lung epithelial cells, it induced a partial disruption of their cell-cell adhesion, while a monoclonal antibody to P-cadherin (PCD-1) showed a subtle effect. A mixture of the two antibodies, however, displayed a synergistic effect. We then tested the effect of the antibodies on the morphogenesis of lung primordia using an organ culture system. In control media, the explants formed typical bronchial trees. In the presence of ECCD-1, the explants grew up at the same rate as in the control, but their morphogenesis was affected. The control explants formed round epithelial lobules with an open luminal space at the tips of the bronchial trees, whereas the lobules of explants incubated with ECCD-1 tended to be flat and devoid of the luminal space. PCD-1 showed a similar but very small effect. A mixture of the two antibodies, however, showed a stronger effect: the branching of epithelia was partially suppressed and the arrangement of epithelial cells was distorted in many places. These results suggest that E- and P-cadherin have a synergistic role in the organization of epithelial cells in lung morphogenesis.

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