scholarly journals Retinoic acid-receptor activation of SP-B gene transcription in respiratory epithelial cells

1998 ◽  
Vol 275 (2) ◽  
pp. L239-L246 ◽  
Author(s):  
Cong Yan ◽  
Manely Ghaffari ◽  
Jeffrey A. Whitsett ◽  
Xin Zeng ◽  
Zvjezdana Sever ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Receptor Activation ◽  
Pulmonary Adenocarcinoma ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Target Cells ◽  
Adenocarcinoma Cells

Retinoids are known to play important roles in organ development of the lung. Retinoids exert their activity by modulating the expression of numerous genes, generally influencing gene transcription, in target cells. In the present work, the mechanism by which retinoic acid (RA) regulates surfactant protein (SP) B expression was assessed in vitro. RA (9- cis-RA) enhanced SP-B mRNA in pulmonary adenocarcinoma cells (H441 cells) and increased transcriptional activity of the SP-B promoter in both H441 and mouse lung epithelial cells (MLE-15). Cotransfection of H441 cells with retinoid nuclear receptor (RAR)-α, -β, and -γ and retinoid X receptor (RXR)-γ further increased the response of the SP-B promoter to RA. Treatment of H441 cells with RA increased immunostaining for the SP-B proprotein and increased the number of cells in which the SP-B proprotein was detected. An RA responsive element mediating RA stimulation of the human SP-B promoter was identified. RAR-α and -γ and RXR-α but not RAR-β or RXR-β and -γ were detected by immunohistochemical analysis of H441 cells. RA, by activating RAR activity, stimulated the transcription and synthesis of SP-B in pulmonary adenocarcinoma cells.

scholarly journals Effect of Slit/Robo signaling on regeneration in lung emphysema

2021 ◽  
Author(s):  
Jin-Soo Park ◽  
RyeonJin Cho ◽  
Eun-Young Kang ◽  
Yeon-Mok Oh
Keyword(s):  
Epithelial Cells ◽  
Mouse Model ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Chronic Obstructive ◽  
Irreversible Damage ◽  
Lung Epithelial ◽  
And Migration ◽  
Proliferation And Migration

AbstractEmphysema, a pathological component of chronic obstructive pulmonary disease, causes irreversible damage to the lung. Previous studies have shown that Slit plays essential roles in cell proliferation, angiogenesis, and organ development. In this study, we evaluated the effect of Slit2 on the proliferation and migration of mouse lung epithelial cells and its role in regeneration in an emphysema lung mouse model. Here, we have shown that Slit2/Robo signaling contributes to the regeneration of lungs damaged by emphysema. Mouse epithelial lung cells treated with Slit2 exhibited increased proliferation and migration in vitro. Our results also showed that Slit2 administration improved alveolar regeneration in the emphysema mouse model in vivo. Furthermore, Slit2/Robo signaling increased the phosphorylation of ERK and Akt, which was mediated by Ras activity. These Slit2-mediated cellular signaling processes may be involved in the proliferation and migration of mouse lung epithelial cells and are also associated with the potential mechanism of lung regeneration. Our findings suggest that Slit2 administration may be beneficial for alveolar regeneration in lungs damaged by emphysema.

scholarly journals Inhibition of hSP-B promoter in respiratory epithelial cells by a dominant negative retinoic acid receptor

1999 ◽  
Vol 276 (3) ◽  
pp. L398-L404 ◽  
Author(s):  
Manely Ghaffari ◽  
Jeffrey A. Whitsett ◽  
Cong Yan
Keyword(s):  
Retinoic Acid ◽  
Epithelial Cells ◽  
Retinoic Acid Receptor ◽  
Nuclear Hormone Receptor ◽  
Dominant Negative ◽  
Mouse Lung ◽  
Dominant Negative Mutant ◽  
Respiratory Epithelial Cells ◽  
Respiratory Epithelial

Retinoic acid (RA) receptors (RARs) belong to the nuclear hormone receptor superfamily and play important roles in lung differentiation, growth, and gene regulation. Surfactant protein (SP) B is a small hydrophobic protein synthesized and secreted by respiratory epithelial cells in the lung. Expression of the SP-Bgene is modulated at the transcriptional and posttranscriptional levels. In the present work, immunohistochemical staining revealed that RAR-α is present on day 14.5 of gestation in the fetal mouse lung. To assess whether RAR is required for SP-B gene transcription, a dominant negative mutant human (h) RAR-α403 was generated. The hRAR-α403 mutant was transcribed and translated into the truncated protein product by reticulocyte lysate in vitro. The mutant retained DNA binding activity in the presence of retinoid X receptor-γ to an RA response element in the hSP-B promoter. When transiently transfected into pulmonary adenocarcinoma epithelial cells (H441 cells), the mutant hRAR-α403 was readily detected in the cell nucleus. Cotransfection of the mutant hRAR-α403 repressed activity of the hSP-B promoter and inhibited RA-induced surfactant proprotein B production in H441 cells, supporting the concept that RAR is required for hSP-Bgene transcription in vitro.

scholarly journals Asymmetric dimethylarginine potentiates lung inflammation in a mouse model of allergic asthma

2010 ◽  
Vol 299 (6) ◽  
pp. L816-L825 ◽  
Author(s):  
Elizabeth Klein ◽  
Jason Weigel ◽  
Mary C. Buford ◽  
Andrij Holian ◽  
Sandra M. Wells
Keyword(s):  
Epithelial Cells ◽  
Lung Inflammation ◽  
Lavage Fluid ◽  
Lung Lavage ◽  
Airway Epithelial Cells ◽  
Inos Expression ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Lung Epithelial

Nitric oxide (NO), formed by nitric oxide synthase (NOS), is an important mediator of lung inflammation in allergic asthma. Asymmetric dimethylarginine (ADMA), a competitive endogenous inhibitor of NOS, is metabolized by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). Elevated ADMA has been shown to affect lung function in mice, and by inhibiting NOS it alters NO and reactive oxygen species production in mouse lung epithelial cells. However, the effects of altered ADMA levels during lung inflammation have not been explored. A model of allergen-induced airway inflammation was utilized in combination with the modulation of endogenous circulating ADMA levels in mice. Airway inflammation was assessed by quantifying inflammatory cell infiltrates in lung lavage and by histology. Lung DDAH expression was assessed by quantitative PCR and immunohistochemistry. Nitrite levels were determined in lung lavage fluid as a measure of NO production. iNOS expression was determined by immunohistochemistry, immunofluorescence, Western blot, and quantitative PCR. NF-κB binding activity was assessed by a transcription factor binding assay. Allergen-induced lung inflammation was potentiated in mice with elevated circulating ADMA and was reduced in mice overexpressing DDAH. Elevated ADMA reduced nitrite levels in lung lavage fluid in both allergen-challenged and control animals. ADMA increased iNOS expression in airway epithelial cells in vivo following allergen challenge and in vitro in stimulated mouse lung epithelial cells. ADMA also increased NF-κB binding activity in airway epithelial cells in vitro. These data support that ADMA may play a role in inflammatory airway diseases such as asthma through modulation of iNOS expression in lung epithelial cells.

Bleomycin initiates apoptosis of lung epithelial cells by ROS but not by Fas/FasL pathway

2006 ◽  
Vol 290 (4) ◽  
pp. L790-L796 ◽  
Author(s):  
Shulamit B. Wallach-Dayan ◽  
Gabriel Izbicki ◽  
Pazit Y. Cohen ◽  
Regina Gerstl-Golan ◽  
Alan Fine ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Lung Epithelial ◽  
Induced Apoptosis

Epithelial cells are considered to be a main target of bleomycin-induced lung injury, which leads to fibrosis in vivo. We studied the characteristics of in vitro bleomycin-induced apoptosis in a mouse lung epithelial (MLE) cell line. Bleomycin caused an increase of reactive oxygen species (ROS) resulting in oxidative stress, mitochondrial leakage, and apoptosis. These were associated with elevated caspase-8 and resultant caspase-9 activity and with upregulation of Fas expression. Glutathione and inhibitors of caspase-8 or caspase-9, but not of FasL, inhibited these effects, suggesting their dependence on ROS, caspase-8 and -9, in a Fas/FasL-independent pathway. However, postbleomycin-exposed MLE cells were more sensitive to Fas-mediated apoptosis. These results demonstrate that the initial bleomycin-induced oxidative stress causes a direct apoptotic effect in lung epithelial cells involving a regulatory role of caspase-8 on caspase-9. Fas represents an amplification mechanism, and not a direct trigger of bleomycin-induced epithelial cell apoptosis.

scholarly journals Berberine and Obatoclax Inhibit SARS-Cov-2 Replication in Primary Human Nasal Epithelial Cells In Vitro

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 282
Author(s):  
Finny S. Varghese ◽  
Esther van Woudenbergh ◽  
Gijs J. Overheul ◽  
Marc J. Eleveld ◽  
Lisa Kurver ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Early Stage ◽  
Antiviral Drugs ◽  
Target Cells ◽  
Nasal Epithelial Cells ◽  
Cytokines And Chemokines ◽  
Human Nasal Epithelial Cells ◽  
Apoptotic Protein ◽  
Air Liquid Interface

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a new human pathogen in late 2019 and it has infected over 100 million people in less than a year. There is a clear need for effective antiviral drugs to complement current preventive measures, including vaccines. In this study, we demonstrate that berberine and obatoclax, two broad-spectrum antiviral compounds, are effective against multiple isolates of SARS-CoV-2. Berberine, a plant-derived alkaloid, inhibited SARS-CoV-2 at low micromolar concentrations and obatoclax, which was originally developed as an anti-apoptotic protein antagonist, was effective at sub-micromolar concentrations. Time-of-addition studies indicated that berberine acts on the late stage of the viral life cycle. In agreement, berberine mildly affected viral RNA synthesis, but it strongly reduced infectious viral titers, leading to an increase in the particle-to-pfu ratio. In contrast, obatoclax acted at the early stage of the infection, which is in line with its activity to neutralize the acidic environment in endosomes. We assessed infection of primary human nasal epithelial cells that were cultured on an air-liquid interface and found that SARS-CoV-2 infection induced and repressed expression of specific sets of cytokines and chemokines. Moreover, both obatoclax and berberine inhibited SARS-CoV-2 replication in these primary target cells. We propose berberine and obatoclax as potential antiviral drugs against SARS-CoV-2 that could be considered for further efficacy testing.

scholarly journals The CRISPR/Cas9 Minipig—A Transgenic Minipig to Produce Specific Mutations in Designated Tissues

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3024
Author(s):  
Martin Fogtmann Berthelsen ◽  
Maria Riedel ◽  
Huiqiang Cai ◽  
Søren H. Skaarup ◽  
Aage K. O. Alstrup ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Somatic Cells ◽  
Genetic Alterations ◽  
Lung Epithelial Cells ◽  
Target Cells ◽  
Multiple Gene ◽  
Conditional Expression ◽  
Gene Alterations

The generation of large transgenic animals is impeded by complex cloning, long maturation and gastrulation times. An introduction of multiple gene alterations increases the complexity. We have cloned a transgenic Cas9 minipig to introduce multiple mutations by CRISPR in somatic cells. Transgenic Cas9 pigs were generated by somatic cell nuclear transfer and were backcrossed to Göttingen Minipigs for two generations. Cas9 expression was controlled by FlpO-mediated recombination and was visualized by translation from red to yellow fluorescent protein. In vitro analyses in primary fibroblasts, keratinocytes and lung epithelial cells confirmed the genetic alterations executed by the viral delivery of single guide RNAs (sgRNA) to the target cells. Moreover, multiple gene alterations could be introduced simultaneously in a cell by viral delivery of sgRNAs. Cells with loss of TP53, PTEN and gain-of-function mutation in KRASG12D showed increased proliferation, confirming a transformation of the primary cells. An in vivo activation of Cas9 expression could be induced by viral delivery to the skin. Overall, we have generated a minipig with conditional expression of Cas9, where multiple gene alterations can be introduced to somatic cells by viral delivery of sgRNA. The development of a transgenic Cas9 minipig facilitates the creation of complex pre-clinical models for cancer research.

Nitric oxide increases IL-8 gene transcription and mRNA stability to enhance IL-8 gene expression in lung epithelial cells

2004 ◽  
Vol 287 (4) ◽  
pp. L764-L773 ◽  
Author(s):  
Loretta Sparkman ◽  
Vijayakumar Boggaram
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Mrna Stability ◽  
Inflammatory Responses ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Lung Epithelial

Interleukin (IL)-8, a C-X-C chemokine, is a potent chemoattractant and an activator for neutrophils, T cells, and other immune cells. The airway and respiratory epithelia play important roles in the initiation and modulation of inflammatory responses via production of cytokines and surfactant. The association between elevated levels of nitric oxide (NO) and IL-8 in acute lung injury associated with sepsis, acute respiratory distress syndrome, respiratory syncytial virus infection in infants, and other inflammatory diseases suggested that NO may play important roles in the control of IL-8 gene expression in the lung. We investigated the role of NO in the control of IL-8 gene expression in H441 lung epithelial cells. We found that a variety of NO donors significantly induced IL-8 mRNA levels, and the increase in IL-8 mRNA was associated with an increase in IL-8 protein. NO induction of IL-8 mRNA was due to increases in IL-8 gene transcription and mRNA stability. NO induction of IL-8 mRNA levels was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively, and 8-bromo-cGMP did not increase IL-8 mRNA levels. This indicated that NO induces IL-8 mRNA levels independently of changes in the intracellular cGMP levels. NO induction of IL-8 mRNA was significantly reduced by inhibitors of extracellular regulated kinase and protein kinase C. IL-8 induction by NO was also reduced by hydroxyl radical scavengers such as dimethyl sulfoxide and dimethylthiourea, indicating the involvement of hydroxyl radicals in the induction process. NO induction of IL-8 gene expression could be a significant contributing factor in the initiation and induction of inflammatory response in the respiratory epithelium.

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