Dual mechanism forMycobacterium tuberculosiscytotoxicity on lung epithelial cells

2012 ◽  
Vol 58 (7) ◽  
pp. 909-916 ◽  
Author(s):  
Jorge Castro-Garza ◽  
W. Edward Swords ◽  
Russell K. Karls ◽  
Frederick D. Quinn
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Neutralizing Antibodies ◽  
Cytotoxic Effect ◽  
Alveolar Epithelial Cell ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Lung Epithelial

Mycobacterium tuberculosis strains CDC1551 and Erdman were used to assess cytotoxicity in infected A549 human alveolar epithelial cell monolayers. Strain CDC1551 was found to induce qualitatively greater disruption of A549 monolayers than was strain Erdman, although total intracellular and cell-associated bacterial growth rates over the course of the infections were not significantly different. Cell-free culture supernatants from human monocytic cells infected with either of the 2 M. tuberculosis strains produced a cytotoxic effect on A549 cells, correlating with the amount of tumor necrosis factor alpha (TNF-α) released by the infected monocytes. The addition of TNF-α-neutralizing antibodies to the supernatants from infected monocyte cultures did prevent the induction of a cytotoxic effect on A549 cells overlaid with this mixture but did not prevent the death of epithelial cells when added prior to infection with M. tuberculosis bacilli. Thus, these data agree with previous observations that lung epithelial cells infected with M. tuberculosis bacilli are rapidly killed in vitro. In addition, the data indicate that some of the observed epithelial cell killing may be collateral damage; the result of TNF-α released from M. tuberculosis-infected monocytes.

scholarly journals TNF Family Cytokines Induce Distinct Cell Death Modalities in the A549 Human Lung Epithelial Cell Line when Administered in Combination with Ricin Toxin

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 450 ◽  
Author(s):  
Hodges ◽  
Kempen ◽  
McCaig ◽  
Parker ◽  
Mantis ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Human Lung ◽  
Lung Epithelial Cells ◽  
Lung Epithelial Cell ◽  
Distinct Cell ◽  
Tnf Α ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

Ricin is a member of the ribosome-inactivating protein (RIP) family of toxins and is classified as a biothreat agent by the Centers for Disease Control and Prevention (CDC). Inhalation, the most potent route of toxicity, triggers an acute respiratory distress-like syndrome that coincides with near complete destruction of the lung epithelium. We previously demonstrated that the TNF-related apoptosis-inducing ligand (TRAIL; CD253) sensitizes human lung epithelial cells to ricin-induced death. Here, we report that ricin/TRAIL-mediated cell death occurs via apoptosis and involves caspases -3, -7, -8, and -9, but not caspase-6. In addition, we show that two other TNF family members, TNF-α and Fas ligand (FasL), also sensitize human lung epithelial cells to ricin-induced death. While ricin/TNF-α- and ricin/FasL-mediated killing of A549 cells was inhibited by the pan-caspase inhibitor, zVAD-fmk, evidence suggests that these pathways were not caspase-dependent apoptosis. We also ruled out necroptosis and pyroptosis. Rather, the combination of ricin plus TNF-α or FasL induced cathepsin-dependent cell death, as evidenced by the use of several pharmacologic inhibitors. We postulate that the effects of zVAD-fmk were due to the molecule’s known off-target effects on cathepsin activity. This work demonstrates that ricin-induced lung epithelial cell killing occurs by distinct cell death pathways dependent on the presence of different sensitizing cytokines, TRAIL, TNF-α, or FasL.

The effects of PM10 particles and oxidative stress on macrophages and lung epithelial cells: modulating effects of calcium-signaling antagonists

2007 ◽  
Vol 292 (6) ◽  
pp. L1444-L1451 ◽  
Author(s):  
David M. Brown ◽  
Laura Hutchison ◽  
Kenneth Donaldson ◽  
Vicki Stone
Keyword(s):  
Oxidative Stress ◽  
Calcium Antagonist ◽  
Epithelial Cells ◽  
Calcium Signaling ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Tnf Α ◽  
Lung Epithelial

We have previously examined the ability of air pollution particles (PM10) to promote release of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) from human peripheral blood mononuclear cells and demonstrated a role for calcium as a signaling molecule in this process. We have now studied the ability of oxidative stress induced by a synthetic oxidant tert-butyl hydroperoxide (tBHP) to induce TNF-α production via calcium signaling in the mouse macrophage cell line (J774). The oxidant tBHP significantly increased intracellular calcium and the release of TNF-α in J774 cells, an effect that was reduced to control levels by inhibition of calcium signaling with verapamil, BAPTA-AM, and W-7. This study also investigated interactions between PM10-treated macrophages and epithelial cells by using conditioned medium (CM) from PM10-treated mononuclear cells to stimulate the release of the neutrophil chemoattractant chemokine IL-8 from A549 lung epithelial cells. TNF-α protein release was demonstrated in human mononuclear cells after PM10 treatment, an effect that was inhibited by calcium antagonists. Treatment of A549 cells with monocyte/PM10 CM produced increased IL-8 release that was reduced with CM from monocyte/PM10/calcium antagonist treatments. The expression of ICAM-1 was increased after incubation with CM from monocyte/PM10 treatment, and this increase was prevented by treatment with CM from monocyte/PM10/calcium antagonist. These data demonstrate a link between oxidative stress, calcium, and inflammatory mediator production in macrophages and lung epithelial cells.

ThePseudomonassecretory product pyocyanin inhibits catalase activity in human lung epithelial cells

2003 ◽  
Vol 285 (5) ◽  
pp. L1077-L1086 ◽  
Author(s):  
Yunxia Q. O'Malley ◽  
Krzysztof J. Reszka ◽  
George T. Rasmussen ◽  
Maher Y. Abdalla ◽  
Gerene M. Denning ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Catalase Activity ◽  
Alveolar Epithelial Cell ◽  
A549 Cells ◽  
Human Cells ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Free System

Pyocyanin, produced by Pseudomonas aeruginosa, has many deleterious effects on human cells that relate to its ability to generate reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. Human cells possess several mechanisms to protect themselves from ROS, including manganese superoxide dismutase (MnSOD), copper zinc superoxide dismutase (CuZnSOD), and catalase. Given the link between pyocyanin-mediated epithelial cell injury and oxidative stress, we assessed pyocyanin's effect on MnSOD, CuZnSOD, and catalase levels in the A549 human alveolar epithelial cell line and in normal human bronchial epithelial cells. In both cell types, CuZnSOD and MnSOD were unaltered, but over 24 h pyocyanin significantly decreased cellular catalase activity and protein content. Pyocyanin also decreased catalase mRNA. Overexpression of MnSOD in A549 cells prevented pyocyanin-mediated loss of catalase protein, but catalase activity still declined. Furthermore, pyocyanin decreased catalase activity, but not protein, in A549 cells overexpressing human catalase. These data suggest a direct effect of pyocyanin on catalase activity. Addition of pyocyanin to catalase in a cell-free system also decreased catalase activity. Mammalian catalase binds four NADPH molecules, helping maintain enzyme activity. Spin-trapping data suggest that pyocyanin directly oxidizes this NADPH, producing superoxide. We conclude that pyocyanin may decrease cellular catalase activity via both transcriptional regulation and direct inactivation of the enzyme. Decreased cellular catalase activity and failure to augment MnSOD could contribute to pyocyanin-dependent cytotoxicity.

PM10-exposed macrophages stimulate a proinflammatory response in lung epithelial cells via TNF-α

2002 ◽  
Vol 282 (2) ◽  
pp. L237-L248 ◽  
Author(s):  
L. A. Jiménez ◽  
E. M. Drost ◽  
P. S. Gilmour ◽  
I. Rahman ◽  
F. Antonicelli ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
A549 Cells ◽  
Conditioned Media ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Protein Levels ◽  
Proinflammatory Mediators ◽  
Tnf Α ◽  
Lung Epithelial

There is now considerable evidence for an association between the levels of particulate air pollution [particulate matter <10 μm in aerodynamic diameter (PM10)] and various adverse health endpoints. The release of proinflammatory mediators from PM10-exposed macrophages may be important in stimulating cytokine release from lung epithelial cells, thus amplifying the inflammatory response. A549 cells were treated with conditioned media from monocyte-derived macrophages stimulated with PM10, titanium dioxide (TiO2), or ultrafine TiO2. We demonstrate that only conditioned media from PM10-stimulated macrophages significantly increased nuclear factor-κB and activator protein-1 DNA binding, enhanced interleukin-8 (IL-8) mRNA levels as assessed by RT-PCR, and augmented IL-8 protein levels, over untreated controls. Furthermore, PM10-conditioned media also caused transactivation of IL-8 as determined by an IL-8-chloramphenicol acetyl transferase reporter. Analysis of these conditioned media revealed marked increases in tumor necrosis factor-α (TNF-α) and protein levels and enhanced chemotactic activity for neutrophils. Preincubation of conditioned media with TNF-α-neutralizing antibodies significantly reduced IL-8 production. These data suggest that PM10-activated macrophages may amplify the inflammatory response by enhancing IL-8 release from lung epithelial cells, in part, via elaboration of TNF-α.

Regulated in Development and DNA Damage Response 1 Knockdown Alleviates Lipopolysaccharide-Induced Acute Lung Injury

2021 ◽  
Vol 11 (7) ◽  
pp. 1333-1338
Author(s):  
Han Han ◽  
Zhenxi Yu ◽  
Mei Feng
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Cell Activity ◽  
Lung Epithelial Cells ◽  
Lung Epithelial Cell ◽  
Inflammatory Factors ◽  
Lung Epithelial ◽  
Damage Response

Regulated in Development and DNA Damage Response 1 (REDD1) knockdown can reduce the endoplasmic reticulum stress response in liver injury. However, its role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored. This study aimed to evaluate the effect of REDD1 on lung epithelial cells induced by LPS. Rt-qPCR and Western blot were used to detect REDD1 expression in 16HBE cells induced by LPS. The interfering REDD1 plasmid was constructed, and CCK8 was used to detect the effect of interference with REDD1 on LPS-induced lung epithelial cell activity. The expression of inflammatory factors was detected by ELISA and the apoptotic level was detected by TUNEL staining. String database was used to predict the combination of REDD1 and EP300 in lung epithelial cells, which was verified by CoIP experiment. An overexpressed plasmid of EP300 was constructed to detect the effects of EP300 on inflammatory factors and apoptosis in REDD1 lung epithelial cells. LPS-induced increased REDD1 expression in lung epithelial cells. Interference with REDD1 inhibits LPS-induced lung epithelial cell activity injury and inflammatory factor expression and inhibits LPS-induced lung epithelial cell apoptosis. After interference with REDD1, the expression of EP300 in LPS-induced lung epithelial cells was inhibited, and the overexpression of EP300 was reversed to promote the production of inflammatory factors and apoptosis. In conclusion, these results demonstrate that REDD1 knockdown alleviates LPS-induced acute lung injury.

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 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 Autocrine Regulation and Experimental Modulation of Interleukin-6 Expression by Human Pulmonary Epithelial Cells Infected with Respiratory Syncytial Virus

1998 ◽  
Vol 72 (3) ◽  
pp. 2496-2499 ◽  
Author(s):  
Zili Jiang ◽  
Masaru Kunimoto ◽  
Janak A. Patel
Keyword(s):  
Respiratory Syncytial Virus ◽  
Epithelial Cells ◽  
Cell Cultures ◽  
Interleukin 6 ◽  
Neutralizing Antibodies ◽  
Antiviral Agent ◽  
Significant Inhibition ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Syncytial Virus

ABSTRACT The mechanisms of regulation of interleukin-6 (IL-6) production in respiratory syncytial virus (RSV)-infected respiratory epithelial cells were evaluated in A549 cell cultures. Incubation with purified RSV resulted in significant production of IL-1α, IL-1β, IL-6, and tumor necrosis factor alpha (TNF-α). Addition of saturating concentrations of neutralizing antibodies against IL-1α, IL-1β, or TNF-α into purified RSV-infected cell cultures resulted in a significant inhibition of IL-6 production, although anti-IL-1α antibody had the most predominant effect (80% inhibition). Anti-IL-1α antibody also almost completely blocked the expression of mRNA for IL-6. Addition of therapeutic concentrations of dexamethasone (1 μM) or ribavirin (90 μg/ml), an antiviral agent, also significantly inhibited the synthesis of IL-6. Hence, in clinical settings, pharmacological agents such as the specific antagonists of IL-6-inducing cytokines, as well as dexamethasone and ribavirin, could be used to modulate IL-6 production.

The lack of attachment of transformed embryonic lung epithelial cells to collagen I is corrected by fibronectin and FXIII

1986 ◽  
Vol 86 (1) ◽  
pp. 95-107
Author(s):  
M. Paye ◽  
C.M. Lapiere
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Lung Epithelial Cells ◽  
Collagen I ◽  
Epithelial Cell Line ◽  
Embryonic Lung ◽  
Lung Epithelial ◽  
Minimal Concentration ◽  
Pulmonary Epithelial Cell

PER cells, a transformed pulmonary epithelial cell line that adhered to a large extent to a fibronectin substratum, were found to be attachment-deficient to collagen I. Although fibronectin can bind to collagen I monomers and polymers, the addition of exogenous fibronectin in the attachment medium induced the adhesion of these cells to collagen I polymers but not to monomers. By adding the transglutaminase of blood coagulation, FXIII, in the presence of fibronectin, the attachment of PER cells to collagen I monomers could be recovered while the minimal concentration of fibronectin needed to promote their adhesion to polymers was lowered. These studies indicate that FXIII enhances the fibronectin-mediated attachment of PER cells to collagen I.

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