scholarly journals 969. GRP78 and Integrin β1/α3 Play Disparate Roles in Epithelium Invasion During Mucormycosis

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S37-S37
Author(s):  
Abdullah Alqarihi ◽  
Teclegiorgis Gebremariam ◽  
Sondus Alkhazraji ◽  
Priya Uppuluri ◽  
John E Edwards ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Host Cell ◽  
Cell Injury ◽  
Lung Epithelial Cells ◽  
Host Cells ◽  
Β1 Integrin ◽  
Dependent Manner ◽  
Cell Receptors ◽  
Lung Epithelial

Abstract Background Mucormycosis is a lethal fungal infection caused by Mucorales. Inhalation is the major route of entry resulting in rhino-orbital or pulmonary infections. Nasal and lung epithelial cells are among the first cells that encounter inhaled spores. We sought to identify the nasal and lung epithelial cell receptors interacting with Rhizopus during tissue invasion. Methods R. delemar-induced nasal (CCL30) or lung epithelial (A549) cell invasion was studied using Uvetix dye, while host cell injury was determined by 51Cr-release assay. Epithelial cell receptors were isolated by affinity purification of biotinylated host cell membrane proteins and then identified by LC-MS. Blocking antibodies were used to confirm the role of the receptor in the invasion/injury assays. For survival studies, ICR mice were immunosuppressed with cyclophosphamide and cortisone acetate on day-2, +3, and +8. Mice were infected with 2.5 × 105R. delemar spores intratracheally, and then treated with a single dose of 100 μg (i.p.) anti-β1 integrin antibody. Placebo mice received 100 µg of isotype-matching IgG. Results R. delemar invades and damages both cells in a time-dependent manner. Nasal Grp78 and alveolar β1α3 integrin were isolated as putative receptors. Polyclonal antibodies targeting Grp78 or β1 integrin blocked R. delemar-mediated endocytosis of nasal and lung cells by ~70%. Also, anti-Grp78 and anti-β1 integrin antibodies blocked R. delemar-induced nasal and lung cell injury by ~60% (P < 0.001). Elevated glucose, iron, or BHB increased the expression of nasal Grp78 by 2- to 6-fold which resulted in enhanced R. delemar-mediated invasion and injury of host cells, while having no effect on β1α3 integrin expression. Finally, β1 antibodies protected mice from mucormycosis with median survival time of 16 days for treated mice versus 11 days for placebo and an overall survival of 30% versus 0% for placebo mice (P = 0.0006). Conclusion The upregulation of Grp78 on nasal epithelial cells in response to physiological elevated concentrations of glucose, iron, and BHB and subsequent enhanced invasion likely to provide insights into why diabetics in ketoacidosis are infected with the rhino-orbital mucormycosis rather than pulmonary disease. Our studies also provide a foundation for therapeutic interventions against mucormycosis. Disclosures All authors: No reported disclosures.

scholarly journals Paracoccidioides brasiliensis downmodulates α3 integrin levels in human lung epithelial cells in a TLR2-dependent manner

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bianca Carla Silva Campitelli de Barros ◽  
Bruna Rocha Almeida ◽  
Erika Suzuki
Keyword(s):  
Epithelial Cells ◽  
Host Cell ◽  
Paracoccidioides Brasiliensis ◽  
Cell Signalling ◽  
Lung Epithelial Cells ◽  
Host Cells ◽  
Signalling Pathways ◽  
Dependent Manner ◽  
Lung Epithelial ◽  
Α3 Integrin

Abstract Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin America and may be caused by the species Paracoccidioides brasiliensis. In the lungs, this fungus interacts with epithelial cells, activating host cell signalling pathways, resulting in the production of inflammatory mediators. This event may be initiated through the activation of Pattern-Recognition Receptors such as Toll-like Receptors (TLRs). By interacting with cell wall components, TLR2 is frequently related to fungal infections. In this work, we show that, after 24 h post-infection with P. brasiliensis, A549 lung epithelial cells presented higher TLR2 levels, which is important for IL-8 secretion. Besides, integrins may also participate in pathogen recognition by host cells. We verified that P. brasiliensis increased α3 integrin levels in A549 cells after 5 h of infection and promoted interaction between this receptor and TLR2. However, after 24 h, surprisingly, we verified a decrease of α3 integrin levels, which was dependent on direct contact between fungi and epithelial cells. Likewise, we observed that TLR2 is important to downmodulate α3 integrin levels after 24 h of infection. Thus, P. brasiliensis can modulate the host inflammatory response by exploiting host cell receptors and cell signalling pathways.

scholarly journals An In Vitro Model to Assess Early Immune Markers following Co-Exposure of Epithelial Cells to Carbon Black (nano)Particles in the Presence of S. Aureus: Differential Induction of Cytokines.

2021 ◽  
Author(s):  
Scott M Brown ◽  
Stephen J Evans ◽  
Michael J Burgum ◽  
Llinos G Harris ◽  
Rowena E Jenkins ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Carbon Black ◽  
Human Skin ◽  
Lung Epithelial Cells ◽  
Nano Particles ◽  
Ageing Population ◽  
Dependent Manner ◽  
Lung Epithelial

Abstract Human exposure to carbon black (CB) is inevitable due to its widespread applications in the medical, industrial and consumer sectors. With an ageing population, it is imperative that the effects of (nano)particle exposure in individuals with compromised immunity or infection are considered. Since barrier immunity provides the first line of defence against CB and the human skin and lung pathogen, Staphylococcus aureus, this work focuses on studying the impact of CB exposure upon compromised immunity during infection on human skin and lung epithelial cells in vitro. The principal aim of the work was to develop an epithelial cell model to characterise (co-)exposure to CB and S. aureus. The work used two human epithelial cell lines, HaCaT (skin) and A549 (lung), ELISA technology to assess the (pro-)inflammatory response, aseptic microbiology techniques to grow S. aureus and a Zetasizer, EDX spectroscopy, and both scanning and transmission electron microscopy (SEM and TEM) to characterise the CB under the conditions used in the study. Physicochemical characterisation of CB confirmed its shape, dramatic polydispersity and potential to aggregate. CB significantly inhibited S. aureus growth, but in a biological media dependent manner. CB did not induce cytokines or antimicrobial peptides from skin and lung epithelial cells, when given alone. In contrast, S. aureus induced a robust interleukin (IL)-8 response in both skin and lung epithelial cells. IL-6 and human beta defensin (hβD)-2 could only be detected when cells were stimulated with S. aureus. However, co-exposure to CB (100µg/ml) and S. aureus resulted in significant inhibition of IL-8 (compared to S. aureus only induced levels). Furthermore, the same co-exposure induced significantly more hβD-2 (compared to S. aureus alone). The ability to detect pathogen responses to particle, in addition to epithelial responses to particle and pathogen is an advance on assessing cell responses under ‘healthy’ conditions and supports the need for developing exposure models under stressed or immunosuppressed conditions. This model will be useful for studying mechanisms of exposure in at-risk groups, including factory workers, the elderly and immunocompromised. Advanced models, that better represent human pathophysiology are essential for understanding cellular mechanisms of toxicity in the 21st Century.

scholarly journals miR-185 mediates lung epithelial cell death after oxidative stress

2016 ◽  
Vol 310 (7) ◽  
pp. L700-L710 ◽  
Author(s):  
Duo Zhang ◽  
Heedoo Lee ◽  
Yong Cao ◽  
Charles S. Dela Cruz ◽  
Yang Jin
Keyword(s):  
Cell Death ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial Cell ◽  
Time Dependent ◽  
Dependent Manner ◽  
Lung Epithelial ◽  
Class Iia Hdacs ◽  
Epithelial Cell Death

Lung epithelial cell death is a prominent feature involved in the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Hyperoxia-induced ALI is an established animal model mimicking human ARDS. Small noncoding RNAs such as microRNAs (miRNAs) have potent physiological and pathological functions involving multiple disease processes. Emerging interests focus on the potential of miRNAs to serve as novel therapeutic targets and diagnostic biomarkers. We found that hyperoxia highly induces miR-185 and its precursor in human lung epithelial cells in a time-dependent manner, and this observation is confirmed using mouse primary lung epithelial cells. The hyperoxia-induced miR-185 is mediated by reactive oxygen species. Furthermore, histone deacetylase 4 (HDAC4) locates in the promoter region of miR-185. We found that hyperoxia suppresses HDAC4 specifically in a time-dependent manner and subsequently affects histone deacetylation, resulting in an elevated miR-185 transcription. Using MC1586, an inhibitor of class IIa HDACs, we showed that inhibition of class IIa HDACs upregulates the expression of miR-185, mimicking the effects of hyperoxia. Functionally, miR-185 promotes hyperoxia-induced lung epithelial cell death through inducing DNA damage. We confirmed functional roles of miR-185 using both the loss- and gain-of-function approaches. Moreover, multiple 14-3-3δ pathway proteins are highly attenuated by miR-185 in the presence of hyperoxia. Taken together, hyperoxia-induced miR-185 in lung epithelial cells contributes to oxidative stress-associated epithelial cell death through enhanced DNA damage and modulation of 14-3-3δ pathways.

scholarly journals Host DNA Repair Proteins in Response toPseudomonas aeruginosain Lung Epithelial Cells and in Mice

2010 ◽  
Vol 79 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Min Wu ◽  
Huang Huang ◽  
Weidong Zhang ◽  
Shibichakravarthy Kannan ◽  
Andrew Weaver ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Epithelial Cells ◽  
Critical Role ◽  
Lung Epithelial Cells ◽  
Host Cells ◽  
Myeloperoxidase Activity ◽  
Gram Negative ◽  
Lung Epithelial ◽  
Dna Repair Proteins

ABSTRACTAlthough DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacteriumPseudomonas aeruginosasignificantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection withP. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate thatP. aeruginosainfection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response toP. aeruginosainfection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.

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.

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.

scholarly journals Cytotoxic Effects of Air Freshener Biocides in Lung Epithelial Cells

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800
Author(s):  
Jung-Taek Kwon ◽  
Mimi Lee ◽  
Gun-Baek Seo ◽  
Hyun-Mi Kim ◽  
Ilseob Shim ◽  
...  
Keyword(s):  
Dna Damage ◽  
Epithelial Cells ◽  
Cell Viability ◽  
Lung Epithelial Cells ◽  
Ros Generation ◽  
Dependent Manner ◽  
Cytotoxic Effects ◽  
Lung Epithelial ◽  
Dose Dependent ◽  
A549 Lung

This study evaluated the cytotoxicity of mixtures of citral (CTR) and either benzisothiazolinone (BIT, Mix-CTR-BIT) or triclosan (TCS, Mix-CTR-TCS) in human A549 lung epithelial cells. We investigated the effects of various mix ratios of these common air freshener ingredients on cell viability, cell proliferation, reactive oxygen species (ROS) generation, and DNA damage. Mix-CTR-BIT and Mix-CTR-TCS significantly decreased the viability of lung epithelial cells and inhibited cell growth in a dose-dependent manner. In addition, both mixtures increased ROS generation, compared to that observed in control cells. In particular, cell viability, growth, and morphology were affected upon increase in the proportion of BIT or TCS in the mixture. However, comet analysis showed that treatment of cells with Mix-CTR-BIT or Mix-CTR-TCS did not increase DNA damage. Taken together, these data suggested that increasing the content of biocides in air fresheners might induce cytotoxicity, and that screening these compounds using lung epithelial cells may contribute to hazard assessment.

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.

Captopril inhibits apoptosis in human lung epithelial cells: a potential antifibrotic mechanism

1998 ◽  
Vol 275 (5) ◽  
pp. L1013-L1017 ◽  
Author(s):  
Bruce D. Uhal ◽  
Claudia Gidea ◽  
Raed Bargout ◽  
Antonio Bifero ◽  
Olivia Ibarra-Sunga ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Dna Fragmentation ◽  
Cell Apoptosis ◽  
Human Lung ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Epithelial Cell Apoptosis

The angiotensin-converting enzyme inhibitor captopril has been shown to inhibit fibrogenesis in the lung, but the mechanisms underlying this action are unclear. Apoptosis of lung epithelial cells is believed to be involved in the pathogenesis of pulmonary fibrosis. For these reasons, we studied the effect of captopril on Fas-induced apoptosis in a human lung epithelial cell line. Monoclonal antibodies that activate the Fas receptor induced epithelial cell apoptosis as detected by chromatin condensation, nuclear fragmentation, DNA fragmentation, and increased activities of caspase-1 and -3. Apoptosis was not induced by isotype-matched nonimmune mouse immunoglobulins or nonactivating anti-Fas monoclonal antibodies. When applied simultaneously with anti-Fas antibodies, 50 ng/ml of captopril completely abrogated apoptotic indexes based on morphology, DNA fragmentation, and inducible caspase-1 activity and significantly decreased the inducible activity of caspase-3. Inhibition of apoptosis by captopril was concentration dependent, with an IC50 of 70 pg/ml. These data suggest that the inhibitory actions of captopril on pulmonary fibrosis may be related to prevention of lung epithelial cell apoptosis.

scholarly journals Inhibition of acute lethal pulmonary inflammation by the IDO–AhR pathway

2017 ◽  
Vol 114 (29) ◽  
pp. E5881-E5890 ◽  
Author(s):  
Soung-Min Lee ◽  
Ha Young Park ◽  
Young-Sill Suh ◽  
Eun Hye Yoon ◽  
Juyang Kim ◽  
...  
Keyword(s):  
T Cells ◽  
Epithelial Cells ◽  
Pulmonary Inflammation ◽  
Lung Parenchyma ◽  
Lung Epithelial Cells ◽  
Dependent Manner ◽  
Independent Manner ◽  
Hematopoietic Stem ◽  
Lung Epithelial ◽  
Ifn Γ

The lung is a prototypic organ that was evolved to reduce immunopathology during the immune response to potentially hazardous endogenous and exogenous antigens. In this study, we show that donor CD4+ T cells transiently induced expression of indoleamine 2,3-dioxygenase (IDO) in lung parenchyma in an IFN-γ–dependent manner early after allogeneic hematopoietic stem cell transplantation (HSCT). Abrogation of host IDO expression by deletion of the IDO gene or the IFN-γ gene in donor T cells or by FK506 treatment resulted in acute lethal pulmonary inflammation known as idiopathic pneumonia syndrome (IPS). Interestingly, IL-6 strongly induced IDO expression in an IFN-γ–independent manner when deacetylation of STAT3 was inhibited. Accordingly, a histone deacetylase inhibitor (HDACi) could reduce IPS in the state where IFN-γ expression was suppressed by FK506. Finally, l-kynurenine produced by lung epithelial cells and alveolar macrophages during IPS progression suppresses the inflammatory activities of lung epithelial cells and CD4+ T cells through the aryl hydrocarbon receptor pathway. Taken together, our results reveal that IDO is a critical regulator of acute pulmonary inflammation and that regulation of IDO expression by HDACi may be a therapeutic approach for IPS after HSCT.

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