scholarly journals In Vitro Cellular Toxicity PredictsPseudomonas aeruginosa Virulence in Lung Infections

1998 ◽  
Vol 66 (7) ◽  
pp. 3242-3249 ◽  
Author(s):  
Teiji Sawa ◽  
Maria Ohara ◽  
Kiyoyasu Kurahashi ◽  
Sally S. Twining ◽  
Dara W. Frank ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Quorum Sensing ◽  
Homoserine Lactone ◽  
Lung Epithelial Cells ◽  
Cellular Damage ◽  
Culture Cells ◽  
Invasive Strain ◽  
In Vivo Cytotoxicity

ABSTRACT The role of quorum sensing by Pseudomonas aeruginosa in producing cytotoxicity has not been fully investigated. Strains ofP. aeruginosa have been characterized as having an invasive or a cytotoxic phenotype (S. M. J. Fleiszig et al., Infect. Immun. 65:579–586, 1997). We noted that the application of a large inoculum of the invasive strain 6294 caused cytotoxicity of cultured epithelial cells. To investigate this dose-related cytotoxicity, we compared the behavior of 6294 to that of another invasive strain, PAO1, and determined whether the cytotoxicity could be related to quorum sensing. Both invasive strains, 6294 and PAO1, appear to have quorum-sensing systems that were operative when large doses of bacteria were applied to cultured lung epithelial cells or instilled into the lungs of animals. Nonetheless, only 6294 was cytotoxic. Cytotoxicity induced by 6294 correlated with increased elastase production. These experiments suggest that there are multiple mechanisms for the induction of cytotoxicity, pathology, and mortality in vivo. However, in vivo cytotoxicity and mortality, but not pathology, could be predicted by quantitative in vitro cellular damage experiments utilizing a range of bacteria-to-cell ratios. It appears that quorum sensing may inversely correlate with virulence in that strains that produced PAI [N-(3-oxododecanoyl) homoserine lactone] also appeared to attract more polymorphonuclear leukocytes in vivo and were possibly eliminated more quickly. In addition, exoproduct production in bacteriological medium in vitro may differ significantly from exoproduct expression from infections in vivo or during cocultivation of bacteria with tissue culture cells.

In vitro and in vivo pathologic effects of Vibrio parahaemolyticus on human epithelial cells

1984 ◽  
Vol 30 (3) ◽  
pp. 381-388 ◽  
Author(s):  
B. R. Merrell ◽  
R. I. Walker ◽  
S. W. Joseph
Keyword(s):  
Epithelial Cells ◽  
Epithelial Tissue ◽  
Ileal Mucosa ◽  
Cytotoxic Factor ◽  
Culture Cells ◽  
Vibrio Parahemolyticus ◽  
Buccal Epithelial Cells ◽  
Culture Supernate

The initial interaction and adherence of Vibrio parahemolyticus to epithelial tissue culture cells, human buccal epithelial cells, and the ileal mucosa of mice were studied. Using scanning electron microscopy, adherent bacteria were observed only on degenerating human embryonic intestinal, HeLa, and buccal cells; healthy normal cells were devoid of bacteria. Sheared V. parahaemolyticus, i.e., lacking flagella, did not adhere to either normal or degenerating tissue cells. Neither ultraviolet-inactivated organisms nor cell-free culture supernate affected the epithelial cells. Similar findings were observed on the mucosa of the ileum in mice inoculated with V. parahaemolyticus. It appears that V. parahaemolyticus possesses a cytotoxic factor which alters epithelial cells. This factor appears to be closely associated with viable organisms and may be a functional element in the adherence process of flagellated V. parahaemolyticus to mammalian epithelial cells.

scholarly journals Influenza A Virus Infection Induces Apical Redistribution of Na+, K+-ATPase in Lung Epithelial Cells In Vitro and In Vivo

2019 ◽  
Vol 61 (3) ◽  
pp. 395-398
Author(s):  
Christin Peteranderl ◽  
Irina Kuznetsova ◽  
Jessica Schulze ◽  
Martin Hardt ◽  
Emilia Lecuona ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Influenza A Virus Infection

scholarly journals A High Content Screen for Mucin-1-Reducing Compounds Identifies Fostamatinib as a Candidate for Rapid Repurposing for Acute Lung Injury during the COVID-19 pandemic

2020 ◽  
Author(s):  
Maria Alimova ◽  
Eriene-Heidi Sidhom ◽  
Abhigyan Satyam ◽  
Moran Dvela-Levitt ◽  
Michelle Melanson ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Drug Repurposing ◽  
Lung Epithelial Cells ◽  
Drug Candidate ◽  
Mucin 1 ◽  
Standing Up

SummaryDrug repurposing is the only method capable of delivering treatments on the shortened time-scale required for patients afflicted with lung disease arising from SARS-CoV-2 infection. Mucin-1 (MUC1), a membrane-bound molecule expressed on the apical surfaces of most mucosal epithelial cells, is a biochemical marker whose elevated levels predict the development of acute lung injury (ALI) and respiratory distress syndrome (ARDS), and correlate with poor clinical outcomes. In response to the pandemic spread of SARS-CoV-2, we took advantage of a high content screen of 3,713 compounds at different stages of clinical development to identify FDA-approved compounds that reduce MUC1 protein abundance. Our screen identified Fostamatinib (R788), an inhibitor of spleen tyrosine kinase (SYK) approved for the treatment of chronic immune thrombocytopenia, as a repurposing candidate for the treatment of ALI. In vivo, Fostamatinib reduced MUC1 abundance in lung epithelial cells in a mouse model of ALI. In vitro, SYK inhibition by Fostamatinib promoted MUC1 removal from the cell surface. Our work reveals Fostamatinib as a repurposing drug candidate for ALI and provides the rationale for rapidly standing up clinical trials to test Fostamatinib efficacy in patients with COVID-19 lung injury.

scholarly journals DPP4 inhibition by sitagliptin attenuates LPS-induced lung injury in mice

2018 ◽  
Vol 315 (5) ◽  
pp. L834-L845 ◽  
Author(s):  
Takeshi Kawasaki ◽  
Weiguo Chen ◽  
Yu Maw Htwe ◽  
Koichiro Tatsumi ◽  
Steven M. Dudek
Keyword(s):  
Epithelial Cells ◽  
Lung Injury ◽  
Human Lung ◽  
Cell Number ◽  
Lung Epithelial Cells ◽  
Dpp4 Inhibitors ◽  
Anti Inflammatory ◽  
Dpp4 Inhibition

Acute respiratory distress syndrome (ARDS) is a severe clinical condition marked by acute respiratory failure and dysregulated inflammation. Pulmonary vascular endothelial cells (PVECs) function as an important pro-inflammatory source in ARDS, suggesting that modulation of inflammatory events at the endothelial level may have a therapeutic benefit. Dipeptidyl peptidase-4 (DPP4) inhibitors, widely used for the treatment of diabetes mellitus, have been reported to have possible anti-inflammatory effects. However, the potential anti-inflammatory effects of DPP4 inhibition on PVEC function and ARDS pathophysiology are unknown. Therefore, we evaluated the effects of sitagliptin, a DPP4 inhibitor in wide clinical use, on LPS-induced lung injury in mice and in human lung ECs in vitro. In vivo, sitagliptin reduced serum DPP4 activity, bronchoalveolar lavage protein concentration, cell number, and proinflammatory cytokine levels after LPS and alleviated histological findings of lung injury. LPS decreased the expression levels of CD26/DPP4 on pulmonary epithelial cells and PVECs isolated from mouse lungs, and the effect was partially reversed by sitagliptin. In vitro, human lung microvascular ECs (HLMVECs) expressed higher levels of CD26/DPP4 than human pulmonary arterial ECs. LPS induced the release of TNFα, IL-6, and IL-8 by HLMVECs that were inhibited by sitagliptin. LPS promoted the proliferation of HLMVECs, and sitagliptin suppressed this response. However, sitagliptin failed to reverse LPS-induced permeability in cultured ECs or lung epithelial cells in vitro. In summary, sitagliptin attenuates LPS-induced lung injury in mice and exerts anti-inflammatory effects on HLMVECs. These novel observations indicate DPP4 inhibitors may have potential as therapeutic drugs for ARDS.

scholarly journals Engineering quorum quenching enzymes: progress and perspectives

2019 ◽  
Vol 47 (3) ◽  
pp. 793-800 ◽  
Author(s):  
Shereen A. Murugayah ◽  
Monica L. Gerth
Keyword(s):  
Quorum Sensing ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Microbial Pathogens ◽  
Human Pathogens ◽  
New Approach ◽  
Signalling Molecules ◽  
The Stability

Abstract Quorum sensing is a key contributor to the virulence of many important plant, animal and human pathogens. The disruption of this signalling—a process referred to as ‘quorum quenching’—is a promising new approach for controlling microbial pathogens. In this mini-review, we have focused on efforts to engineer enzymes that disrupt quorum sensing by inactivating acyl-homoserine lactone signalling molecules. We review different approaches for protein engineering and provide examples of how these engineering approaches have been used to tailor the stability, specificity and activities of quorum quenching enzymes. Finally, we grapple with some of the issues around these approaches—including the disconnect between in vitro biochemistry and potential in vivo applications.

Maresin 1 Maintains the Permeability of Lung Epithelial Cells In Vitro and In Vivo

Inflammation ◽  
2016 ◽  
Vol 39 (6) ◽  
pp. 1981-1989 ◽  
Author(s):  
Lin Chen ◽  
Hong Liu ◽  
Yaxin Wang ◽  
Haifa Xia ◽  
Jie Gong ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Maresin 1

scholarly journals Bactofection of lung epithelial cells in vitro and in vivo using a genetically modified Escherichia coli

Gene Therapy ◽  
2008 ◽  
Vol 15 (6) ◽  
pp. 434-442 ◽  
Author(s):  
M D B Larsen ◽  
U Griesenbach ◽  
S Goussard ◽  
D C Gruenert ◽  
D M Geddes ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Genetically Modified ◽  
Lung Epithelial Cells ◽  
Lung Epithelial

scholarly journals Role of the C-Terminal Domain of the Alpha Subunit of RNA Polymerase in LuxR-Dependent Transcriptional Activation of the lux Operon during Quorum Sensing

2002 ◽  
Vol 184 (16) ◽  
pp. 4520-4528 ◽  
Author(s):  
Angela H. Finney ◽  
Robert J. Blick ◽  
Katsuhiko Murakami ◽  
Akira Ishihama ◽  
Ann M. Stevens
Keyword(s):  
Quorum Sensing ◽  
Rna Polymerase ◽  
Transcriptional Activation ◽  
Homoserine Lactone ◽  
Dependent Manner ◽  
Α Subunit ◽  
Terminal Domain

ABSTRACT During quorum sensing in Vibrio fischeri, the luminescence, or lux, operon is regulated in a cell density-dependent manner by the activator LuxR in the presence of an acylated homoserine lactone autoinducer molecule [N-(3-oxohexanoyl) homoserine lactone]. LuxR, which binds to the lux operon promoter at a position centered at −42.5 relative to the transcription initiation site, is thought to function as an ambidextrous activator making multiple contacts with RNA polymerase (RNAP). The specific role of the α-subunit C-terminal domain (αCTD) of RNAP in LuxR-dependent transcriptional activation of the lux operon promoter has been investigated. The effects of 70 alanine substitution variants of the α subunit were determined in vivo by measuring the rate of transcription of the lux operon via luciferase assays in recombinant Escherichia coli. The mutant RNAPs from strains exhibiting at least twofold-increased or -decreased activity in comparison to the wild type were further examined by in vitro assays. Since full-length LuxR has not been purified, an autoinducer-independent N-terminally truncated form of LuxR, LuxRΔN, was used for in vitro studies. Single-round transcription assays were performed using reconstituted mutant RNAPs in the presence of LuxRΔN, and 14 alanine substitutions in the αCTD were identified as having negative effects on the rate of transcription from the lux operon promoter. Five of these 14 α variants were also involved in the mechanisms of both LuxR- and LuxRΔN-dependent activation in vivo. The positions of these residues lie roughly within the 265 and 287 determinants in α that have been identified through studies of the cyclic AMP receptor protein and its interactions with RNAP. This suggests a model where residues 262, 265, and 296 in α play roles in DNA recognition and residues 290 and 314 play roles in α-LuxR interactions at the lux operon promoter during quorum sensing.

scholarly journals Study Effects of Drug Treatment and Physiological Physical Stimulation on Surfactant Protein Expression of Lung Epithelial Cells Using a Biomimetic Microfluidic Cell Culture Device

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 400 ◽  
Author(s):  
Ting-Ru Lin ◽  
Sih-Ling Yeh ◽  
Chien-Chung Peng ◽  
Wei-Hao Liao ◽  
Yi-Chung Tung
Keyword(s):  
Cell Culture ◽  
Epithelial Cells ◽  
Drug Treatment ◽  
Surfactant Protein ◽  
Lung Epithelial Cells ◽  
Single Chip ◽  
Physical Stimulation ◽  
Lung Epithelial

This paper reports a biomimetic microfluidic device capable of reconstituting physiological physical microenvironments in lungs during fetal development for cell culture. The device integrates controllability of both hydrostatic pressure and cyclic substrate deformation within a single chip to better mimic the in vivo microenvironments. For demonstration, the effects of drug treatment and physical stimulations on surfactant protein C (SPC) expression of lung epithelial cells (A549) are studied using the device. The experimental results confirm the device’s capability of mimicking in vivo microenvironments with multiple physical stimulations for cell culture applications. Furthermore, the results indicate the critical roles of physical stimulations in regulating cellular behaviors. With the demonstrated functionalities and performance, the device is expected to provide a powerful tool for further lung development studies that can be translated to clinical observation in a more straightforward manner. Consequently, the device is promising for construction of more in vitro physiological microenvironments integrating multiple physical stimulations to better study organ development and its functions.

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