scholarly journals Organic dust inhibits surfactant protein expression by reducing thyroid transcription factor-1 levels in human lung epithelial cells

2019 ◽  
Vol 25 (2) ◽  
pp. 118-131 ◽  
Author(s):  
Kartiga Natarajan ◽  
Keerthi Gangam ◽  
Velmurugan Meganathan ◽  
Koteswara R Gottipati ◽  
Courtney Mitchell ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Respiratory Diseases ◽  
Lung Epithelial Cells ◽  
Organic Dust ◽  
Protein Levels ◽  
Thyroid Transcription Factor 1 ◽  
Thyroid Transcription Factor ◽  
Lung Epithelial ◽  
Transcription Factor 1 ◽  
Dust Extract

Exposure to organic dust is a risk factor for the development of respiratory diseases. Surfactant proteins (SP) reduce alveolar surface tension and modulate innate immune responses to control lung inflammation. Therefore, changes in SP levels could contribute to the development of organic-dust-induced respiratory diseases. Because information on the effects of organic dust on SP levels is lacking, we studied the effects of dust from a poultry farm on SP expression. We found that dust extract reduced SP-A and SP-B mRNA and protein levels in H441 human lung epithelial cells by inhibiting their promoter activities, but did not have any effect on SP-D protein levels. Dust extract also reduced SP-A and SP-C levels in primary human alveolar epithelial cells. The inhibitory effects were not due to LPS or protease activities present in dust extract or mediated via oxidative stress, but were dependent on a heat-labile factor(s). Thyroid transcription factor-1, a key transcriptional activator of SP expression, was reduced in dust-extract-treated cells, indicating that its down-regulation mediates inhibition of SP levels. Our study implies that down-regulation of SP levels by organic dust could contribute to the development of lung inflammation and respiratory diseases in humans.

scholarly journals Thyroid transcription factor-1 (TTF-1) gene: identification of ZBP-89, Sp1, and TTF-1 sites in the promoter and regulation by TNF-α in lung epithelial cells

2011 ◽  
Vol 301 (4) ◽  
pp. L427-L440 ◽  
Author(s):  
Aparajita Das ◽  
Sunil Acharya ◽  
Koteswara Rao Gottipati ◽  
James B. McKnight ◽  
Hemakumar Chandru ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Surfactant Protein ◽  
Serine Phosphorylation ◽  
Lung Epithelial Cells ◽  
Proximal Promoter ◽  
Protein Levels ◽  
Thyroid Transcription Factor 1 ◽  
Thyroid Transcription Factor ◽  
Tnf Α ◽  
Transcription Factor 1

Thyroid transcription factor-1 (TTF-1/Nkx2.1/TITF1) is a homeodomain-containing transcription factor essential for the morphogenesis and differentiation of the lung. In the lung, TTF-1 controls the expression of surfactant proteins that are essential for lung stability and lung host defense. In this study, we identified functionally important transcription factor binding sites in the TTF-1 proximal promoter and studied tumor necrosis factor-α (TNF-α) regulation of TTF-1 expression. TNF-α, a proinflammatory cytokine, has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) and inhibits surfactant protein levels. Deletion analysis of TTF-1 5′-flanking DNA indicated that the TTF-1 proximal promoter retained high-level activity. Electrophoretic mobility shift assay, chromatin immunoprecipitation, and mutational analysis experiments identified functional ZBP-89, Sp1, Sp3, and TTF-1 sites in the TTF-1 proximal promoter. TNF-α inhibited TTF-1 protein levels in H441 and primary alveolar type II cells. TNF-α inhibited TTF-1 gene transcription and promoter activity, indicating that transcriptional mechanisms play important roles in the inhibition of TTF-1 levels. TNF-α inhibited TTF-1 but not Sp1 or hepatocyte nuclear factor-3 DNA binding to TTF-1 promoter. Transactivation experiments in A549 cells indicated that TNF-α inhibited TTF-1 promoter activation by exogenous Sp1 and TTF-1 without altering their levels, suggesting inhibition of transcriptional activities of these proteins. TNF-α inhibition of TTF-1 expression was associated with increased threonine, but not serine, phosphorylation of Sp1. Because TTF-1 serves as a positive regulator for surfactant protein gene expression, TNF-α inhibition of TTF-1 expression could have important implications for the reduction of surfactant protein levels in diseases such as ARDS.

scholarly journals Effect of Alpha-1 Antitrypsin on CFTR Levels in Primary Human Airway Epithelial Cells Grown at the Air-Liquid-Interface

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2639
Author(s):  
Frauke Stanke ◽  
Sabina Janciauskiene ◽  
Stephanie Tamm ◽  
Sabine Wrenger ◽  
Ellen Luise Raddatz ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Liquid Interface ◽  
Lung Epithelial Cells ◽  
Western Blots ◽  
Mesenchymal Transition ◽  
Protein Levels ◽  
Lung Epithelial ◽  
Cftr Protein ◽  
Air Liquid Interface

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is influenced by the fundamental cellular processes like epithelial differentiation/polarization, regeneration and epithelial–mesenchymal transition. Defects in CFTR protein levels and/or function lead to decreased airway surface liquid layer facilitating microbial colonization and inflammation. The SERPINA1 gene, encoding alpha1-antitrypsin (AAT) protein, is one of the genes implicated in CF, however it remains unknown whether AAT has any influence on CFTR levels. In this study we assessed CFTR protein levels in primary human lung epithelial cells grown at the air-liquid-interface (ALI) alone or pre-incubated with AAT by Western blots and immunohistochemistry. Histological analysis of ALI inserts revealed CFTR- and AAT-positive cells but no AAT-CFTR co-localization. When 0.5 mg/mL of AAT was added to apical or basolateral compartments of pro-inflammatory activated ALI cultures, CFTR levels increased relative to activated ALIs. This finding suggests that AAT is CFTR-modulating protein, albeit its effects may depend on the concentration and the route of administration. Human lung epithelial ALI cultures provide a useful tool for studies in detail how AAT or other pharmaceuticals affect the levels and activity of CFTR.

scholarly journals Down-Regulation of p23 in Normal Lung Epithelial Cells Reduces Toxicities From Exposure to Benzo[a]pyrene and Cigarette Smoke Condensate via an Aryl Hydrocarbon Receptor-Dependent Mechanism

2018 ◽  
Vol 167 (1) ◽  
pp. 239-248 ◽  
Author(s):  
Jinyun Chen ◽  
Poonam Yakkundi ◽  
William K Chan
Keyword(s):  
Epithelial Cells ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Lung Epithelial Cells ◽  
Normal Lung ◽  
Cigarette Smoke Condensate ◽  
Down Regulation ◽  
Protein Levels ◽  
Aryl Hydrocarbon ◽  
Lung Epithelial

Abstract The aryl hydrocarbon receptor (AHR) is a ligand-activated signaling molecule which controls tumor growth and metastasis, T cell differentiation, and liver development. Expression levels of this receptor protein is sensitive to the cellular p23 protein levels in immortalized cancer cell lines. As little as 30% reduction of the p23 cellular content can suppress the AHR function. Here we reported that down-regulation of the p23 protein content in normal, untransformed human bronchial/tracheal epithelial cells to 48% of its content also suppresses the AHR protein levels to 54% of its content. This p23-mediated suppression of AHR is responsible for the suppression of (1) the ligand-dependent induction of the cyp1a1 gene transcription; (2) the benzo[a]pyrene- or cigarette smoke condensate-induced CYP1A1 enzyme activity, and (3) the benzo[a]pyrene and cigarette smoke condensate-mediated production of reactive oxygen species. Reduction of the p23 content does not alter expression of oxidative stress genes and production of PGE2. Down regulation of p23 suppresses the AHR protein levels in two other untransformed cell types, namely human breast MCF-10A and mouse immune regulatory Tr1 cells. Collectively, down-regulation of p23 suppresses the AHR protein levels in normal and untransformed cells and can in principle protect our lung epithelial cells from AHR-dependent oxidative damage caused by exposure to agents from environment and cigarette smoking.

scholarly journals CD34 Expression in the Stromal Cells of Alveolar Adenoma

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Nicolina De Rosa ◽  
Alfonso Maiorino ◽  
Ilaria De Rosa ◽  
Carlo Curcio ◽  
Carmine Sellitto ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Stromal Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Thyroid Transcription Factor 1 ◽  
Thyroid Transcription Factor ◽  
Rare Benign Tumor ◽  
Transcription Factor 1 ◽  
Cd34 Positivity

The alveolar adenoma of the lung is a rare benign tumor characterized by a proliferation of both the alveolar epithelial cells and the mesenchymal septal cells. Immunohistochemically, the epithelial cells stain for cytokeratin (CK) AE1AE3, CK7, thyroid transcription factor 1 (TTF1), and surfactant apoprotein confirming the derivation by the type 2 pneumocytes. The stromal cells are negative for these markers but they show focally smooth muscle and muscle-specific actin positivity. We describe two cases that showed immunohistochemically a CD34 positivity of the mesenchymal septal cells. This aspect has been previously described in a two cases report, but not emphasized by the authors as a distinctive feature of the lesion. We consider this CD34 positivity as a marker of immaturity or stemness of the lesional septal spindle cells, that could be responsible of the different phenotypic and morphological profile of the interstitial cells, that could be, therefore, considered neoplastic and not reactive.

scholarly journals Overexpression of USP14 Protease Reduces I-κB Protein Levels and Increases Cytokine Release in Lung Epithelial Cells

2013 ◽  
Vol 288 (22) ◽  
pp. 15437-15441 ◽  
Author(s):  
Rachel K. Mialki ◽  
Jing Zhao ◽  
Jianxin Wei ◽  
Daniel F. Mallampalli ◽  
Yutong Zhao
Keyword(s):  
Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Cytokine Release ◽  
Protein Levels ◽  
Lung Epithelial

scholarly journals IGFBP2 protects against pulmonary fibrosis through inhibiting P21-mediated senescence

2021 ◽  
Author(s):  
Chin Chiahsuan ◽  
John Lee ◽  
Ranjith Ravichandran ◽  
Timothy Fleming ◽  
Stephen Wheatcroft ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Lung Epithelial Cells ◽  
Mouse Lung ◽  
Type Ii ◽  
P21 Protein ◽  
Aged Mice ◽  
Protein Levels ◽  
Age Related ◽  
Lung Epithelial

AbstractAccumulation of senescent cells contributes to age related diseases including idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding proteins (IGFBPs) are evolutionarily conserved proteins that play a vital role in many biological processes. Overall, little is known about the functions of IGFBP2 in the epigenetic regulation of cellular senescence and pulmonary fibrosis. Here, we show that Igfbp2 expression was significantly downregulated at both mRNA and protein levels in a low-dose bleomycin-induced pulmonary fibrosis model of aged mice. Using the reduced representation of bisulfite sequencing technique, we demonstrated Igfbp2 downregulation is attributed to DNA methylation of CpG islands in fibrotic lungs of aged mice. Furthermore, Igfbp2 siRNA knockdown increased both P53 and P21 protein levels in mouse lung epithelial cells exposed to hypoxia treatment. Lentiviral mediated expression of Igfb2 decreased P21 protein levels and significantly reduced beta galactosidase activity in mouse lung epithelial cells challenged with a senescent drug (atazanavir) and hypoxia treatments. Using the RT2 Profiler PCR Array, we found that P21, PAI-1, IRF-5 and IRF-7, important regulators of senescence pathway, were significantly downregulated specifically in type-II alveolar epithelial cells (AECs) of aged human-Igfbp2 transgenic mice after bleomycin challenge. Finally, transgenic expression of human-Igfbp2 in type-II AECs from aged bleomycin challenged mice significantly decreased senescent associated secretory phenotype factors and also reduced extracellular matrix markers compared to aged wild-type mice challenged with bleomycin injury. Collectively, these findings reveal that epigenetic repression of Igfbp2 promotes pulmonary fibrosis and that restoring IGFBP2 in fibrotic lungs could prove effective in IPF treatment.

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