Contribution of IL-1β and TNF-α to the initiation of the peripheral lung response to atmospheric particulates (PM10)

2004 ◽  
Vol 287 (1) ◽  
pp. L176-L183 ◽  
Author(s):  
Hiroshi Ishii ◽  
Takeshi Fujii ◽  
James C. Hogg ◽  
Shizu Hayashi ◽  
Hiroshi Mukae ◽  
...  

Alveolar macrophages (AM) play a key role in clearing atmospheric particulates from the lung surface and stimulating epithelial cells to produce proinflammatory mediators. The present study examines the role of “acute response” cytokines TNF-α and IL-1β released by AM exposed to ambient particulate matter with a diameter of <10 μm (PM10) in amplifying the proinflammatory mediator expression by A549 cells and human bronchial epithelial cells (HBEC). The results showed that supernatants from human AM incubated 24 h with PM10(100 μg/ml) contained more TNF-α, IL-1β, granulocyte-macrophage colony stimulating factor, IL-6, and IL-8 than nonexposed AM supernatants. The 3-h treatment of A549 cells with PM10-exposed AM supernatants increased TNF-α, IL-1β, IL-8, regulated on activation normal T-cells expressed and secreted (RANTES), and leukemia inhibitory factor mRNA compared with the treatment with nonexposed AM supernatants and, compared with untreated A549 cells, additionally increased ICAM-1 and monocyte chemotactic protein-1 mRNA. Preincubating PM10-exposed AM supernatants with anti-IL-1β antibodies reduced all the above mediators as well as VEGF mRNA expression ( P < 0.05), while anti-TNF-α antibodies were less effective ( P > 0.05), and the combination of the two antibodies most effective. When HBEC were treated similarly, anti-TNF-α antibodies had the greatest effect. In A549 cells PM10-exposed AM supernatants increased NF-κB, activator protein (AP)-1 and specificity protein 1 binding, while anti-TNF-α and anti-IL-1β antibodies reduced NF-κB and AP-1 binding. We conclude that AM-derived TNF-α and IL-1β provide a major stimulus for the production of proinflammatory mediators by lung epithelial cells and that their relative importance may depend on the type of epithelial cell target.

2002 ◽  
Vol 282 (2) ◽  
pp. L237-L248 ◽  
Author(s):  
L. A. Jiménez ◽  
E. M. Drost ◽  
P. S. Gilmour ◽  
I. Rahman ◽  
F. Antonicelli ◽  
...  

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.


2012 ◽  
Vol 58 (7) ◽  
pp. 909-916 ◽  
Author(s):  
Jorge Castro-Garza ◽  
W. Edward Swords ◽  
Russell K. Karls ◽  
Frederick D. Quinn

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.


2003 ◽  
Vol 71 (2) ◽  
pp. 614-620 ◽  
Author(s):  
Jun Yang ◽  
W. Craig Hooper ◽  
Donald J. Phillips ◽  
Maria L. Tondella ◽  
Deborah F. Talkington

ABSTRACT Chlamydia pneumoniae is an obligate intracellular human pathogen that causes acute respiratory diseases such as pneumonia and bronchitis. Previous studies have established that C. pneumoniae can induce cytokines in mouse and/or human cells, but little information is available on the cytokine response of respiratory epithelial cells, a first line of infection. In this study, heparin treatment of C. pneumoniae significantly reduced its ability to induce interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) mRNA in human lung carcinoma cells, indicating that cytadherence is an important early stimulus for induction of proinflammatory mediators. Although the IL-8, gamma interferon, and TNF-α message was consistently induced by infection of A549 cells not treated with heparin, only an elevation of IL-8 protein was detected in A549 supernatants. A549 IL-β and IL-6 mRNA and supernatant protein profiles were not significantly changed by infection. Heat or UV inactivation of C. pneumoniae only partially reduced the cytokine response, and inhibition of C. pneumoniae protein or DNA synthesis did not affect its ability to induce cytokine gene expression. To prevent stress-induced cytokine release by the A549 cells, centrifugation was not utilized for infection experiments. These experiments establish the importance of cytadherence in cytokine release by cells of respiratory epithelial origin and suggest that further work in the area of cytokine mediators is warranted to gain valuable pathogenic and therapeutic insights.


2007 ◽  
Vol 292 (6) ◽  
pp. L1444-L1451 ◽  
Author(s):  
David M. Brown ◽  
Laura Hutchison ◽  
Kenneth Donaldson ◽  
Vicki Stone

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.


1997 ◽  
Vol 273 (6) ◽  
pp. L1103-L1111 ◽  
Author(s):  
Mariette L. Yu ◽  
Andrew H. Limper

Inflammatory cell recruitment contributes to respiratory impairment during Pneumocystis carinii pneumonia. We evaluated expression of intercellular adhesion molecule-1 (ICAM-1), a key participant in leukocyte accumulation, in rats with P. carinii pneumonia. Immunostaining for ICAM-1 was most marked on bronchiolar epithelium but was also evident on type II pneumocytes, endothelium, and macrophages. Lung from normal and dexamethasone-treated uninfected animals exhibited markedly less ICAM-1. We hypothesized that P. carinii promoted ICAM-1 expression in epithelium through tumor necrosis factor-α (TNF-α) release from macrophages or that P. carinii directly stimulated ICAM-1 expression. Alveolar macrophages were incubated with P. carinii, and the medium was added to A549 epithelial cells. Treatment of macrophages with P. carinii enhanced A549 ICAM-1, which was inhibited with antibody to TNF-α. To determine whether P. carinii alone also stimulated ICAM-1, A549 cells were cultured with P. carinii, also augmenting ICAM-1. Of note, A549 ICAM-1 expression from P. carinii alone was less than with P. carinii-exposed macrophages. Thus ICAM-1 is enhanced in lung epithelium during P. carinii infection, in part, through TNF-α-mediated mechanisms.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5091
Author(s):  
Acharya Balkrishna ◽  
Siva Kumar Solleti ◽  
Sudeep Verma ◽  
Anurag Varshney

Zebrafish has been a reliable model system for studying human viral pathologies. SARS-CoV-2 viral infection has become a global chaos, affecting millions of people. There is an urgent need to contain the pandemic and develop reliable therapies. We report the use of a humanized zebrafish model, xeno-transplanted with human lung epithelial cells, A549, for studying the protective effects of a tri-herbal medicine Coronil. At human relevant doses of 12 and 58 µg/kg, Coronil inhibited SARS-CoV-2 spike protein, induced humanized zebrafish mortality, and rescued from behavioral fever. Morphological and cellular abnormalities along with granulocyte and macrophage accumulation in the swim bladder were restored to normal. Skin hemorrhage, renal cell degeneration, and necrosis were also significantly attenuated by Coronil treatment. Ultra-high-performance liquid chromatography (UHPLC) analysis identified ursolic acid, betulinic acid, withanone, withaferine A, withanoside IV–V, cordifolioside A, magnoflorine, rosmarinic acid, and palmatine as phyto-metabolites present in Coronil. In A549 cells, Coronil attenuated the IL-1β induced IL-6 and TNF-α cytokine secretions, and decreased TNF-α induced NF-κB/AP-1 transcriptional activity. Taken together, we show the disease modifying immunomodulatory properties of Coronil, at human equivalent doses, in rescuing the pathological features induced by the SARS-CoV-2 spike protein, suggesting its potential use in SARS-CoV-2 infectivity.


2012 ◽  
Vol 302 (7) ◽  
pp. L679-L687 ◽  
Author(s):  
Yong Sung Park ◽  
Erik P. Lillehoj ◽  
Kosuke Kato ◽  
Choon Sik Park ◽  
Kwang Chul Kim

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.


2001 ◽  
Vol 280 (1) ◽  
pp. L30-L38 ◽  
Author(s):  
Jun Araya ◽  
Muneharu Maruyama ◽  
Kazuhiko Sassa ◽  
Tadashi Fujita ◽  
Ryuji Hayashi ◽  
...  

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.


2020 ◽  
Author(s):  
Yinfang Wang ◽  
Yingzhe Fan ◽  
Yitong Huang ◽  
Tao Du ◽  
Zongjun Liu ◽  
...  

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.


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