Tenascin in rat lung development: in situ localization and cellular sources

1995 ◽  
Vol 269 (4) ◽  
pp. L482-L491 ◽  
Author(s):  
Y. Zhao ◽  
S. L. Young
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Lung Tissue ◽  
Lung Development ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Rat Lung ◽  
Alveolar Epithelial

Tenascin (TN) is a hexameric extracellular matrix glycoprotein that may play an important role during lung development. TN protein is temporally and spatially restricted during lung organogenesis. The temporo-spatial and cellular expression of TN mRNA in lung remains unclear. Localization of message expression of TN in rat lung tissue was first investigated by using in situ hybridization performed with an antisense RNA probe. TN mRNA was present primarily within the mesenchyme of day 16 gestational age fetal rat lung tissue, whereas immunoreactive TN protein was found along the basement membrane. In postnatal day 3 rat lung tissue, TN mRNA was detected along alveolar septal walls and was concentrated at secondary septal tips. Expression of TN message was consistent with localization of immunoreactive TN protein. Accumulation of TN mRNA in alveolar septal tips suggests that mesenchyme may be the major source of TN mRNA. To investigate the cellular source of TN in rat lung, we studied the expression of TN in cultured rat lung fibroblasts, endothelial cells, and alveolar epithelial cells. Two TN isoforms having molecular mass of 230 and 180 kDa were in conditioned medium and in cellular extracts of lung fibroblasts and endothelial cells. TN was secreted and deposited in the extracellular matrix closely associated with the surface of lung fibroblasts and endothelial cells. Lung alveolar epithelial cells showed undetectable or barely detectable amounts of TN. These studies demonstrated that TN isoforms are expressed not only by lung fibroblasts but also by lung endothelial cells. The unique spatial localization of TN mRNA during lung development and expression of TN by different lung cell types suggested TN may be involved in matrix organization and cell-cell interactions during lung development.

scholarly journals VEGF in the lung: a role for novel isoforms

2010 ◽  
Vol 298 (6) ◽  
pp. L768-L774 ◽  
Author(s):  
Julia Varet ◽  
Samantha K. Douglas ◽  
Laura Gilmartin ◽  
Andrew R. L. Medford ◽  
David O. Bates ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Lung Tissue ◽  
Alveolar Epithelial Cell ◽  
Vascular Endothelial Cell ◽  
Alveolar Epithelial Cells ◽  
Normal Lung ◽  
Alveolar Type ◽  
Thymidine Uptake ◽  
Alveolar Epithelial

Vascular endothelial cell growth factor (VEGF) is a potent mitogen and permogen that increases in the plasma and decreases in the alveolar space in respiratory diseases such as acute respiratory distress syndrome (ARDS). This observation has led to controversy over the role of this potent molecule in lung physiology and disease. We hypothesized that some of the VEGF previously detected in normal lung may be of the anti-angiogenic family (VEGFxxxb) with significant potential effects on VEGF bioactivity. VEGFxxxb protein expression was assessed by indirect immunohistochemistry in normal and ARDS tissue. Expression of VEGFxxxb was also detected by immunoblotting in normal lung tissue, primary human alveolar type II (ATII) cells, and bronchoalveolar lavage (BAL) fluid in normal subjects and by ELISA in normal, “at risk,” and ARDS subjects. The effect of VEGF165 and VEGF165b on both human primary endothelial cells and alveolar epithelial cell proliferation was assessed by [3H]thymidine uptake. We found that VEGF165b was widely expressed in normal healthy lung tissue but is reduced in ARDS lung. VEGF121b and VEGF165b were present in whole lung, BAL, and ATII lysate. The proliferative effect of VEGF165 on both human primary endothelial cells and human alveolar epithelial cells was significantly inhibited by VEGF165b ( P < 0.01). These data demonstrate that the novel VEGFxxxb family members are expressed in normal lung and are reduced in ARDS. A specific functional effect on primary human endothelial and alveolar epithelial cells has also been shown. These data suggest that the VEGFxxxb family may have a role in repair after lung injury.

scholarly journals Inhibition Mir-92a Alleviates Oxidative Stress and Apoptosis of Alveolar Epithelial Cells Induced by Lipopolysaccharide Exposure through TLR2/AP-1 Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Jian Cui ◽  
Huanhuan Ding ◽  
Yongyuan Yao ◽  
Wei Liu
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Inflammatory Response ◽  
Lung Tissue ◽  
Cell Apoptosis ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Rat Lung ◽  
Alveolar Epithelial

Objective. To probe into the role of miR-92a in alleviating oxidative stress and apoptosis of alveolar epithelial cell (AEC) injury induced by lipopolysaccharide (LPS) exposure through the Toll-like receptor (TLR) 2/activator protein-1 (AP-1) pathway. Methods. Acute lung injury (ALI) rat model and ALI alveolar epithelial cell model were constructed to inhibit the expression of miR-92a/TLR2/AP-1 in rat and alveolar epithelial cells (AECs), to detect the changes of oxidative stress, inflammatory response, and cell apoptosis in rat lung tissues and AECs, and to measure the changes of wet-dry weight (W/D) ratio in rat lung tissues. Results. Both inhibition of miR-92a expression and knockout of TLR2 and AP-1 gene could reduce LPS-induced rat ALI, alleviate pulmonary edema, inhibit oxidative stress and inflammatory response, and reduce apoptosis of lung tissue cells. In addition, the TLR2 and AP-1 levels in the lung tissues of ALI rats were noticed to be suppressed when inhibiting the expression of miR-92a, and the AP-1 level was also decreased after the knockout of TLR2 gene. Further, we verified this relationship in AECs and found that inhibition of miR-92a/TLR2/AP-1 also alleviated LPS-induced AEC injury, reduced cell apoptosis, and inhibited oxidative stress and inflammatory response. What is more, like that in rat lung tissue, the phenomenon also existed in AECs, that is, when the expression of miR-92a was inhibited, the expression of TLR2 and AP-1 was inhibited, and silencing TLR2 can reduce the expression level of AP-1. Conclusion. MiR-92a/TLR2/AP-1 is highly expressed in ALI, and its inhibition can improve oxidative stress and inflammatory response and reduce apoptosis of AECs.

CD40 amplifies Fas-mediated apoptosis: a mechanism contributing to emphysema

2012 ◽  
Vol 303 (2) ◽  
pp. L141-L151 ◽  
Author(s):  
Ayako Shigeta ◽  
Yuji Tada ◽  
Ji-Yang Wang ◽  
Shunsuke Ishizaki ◽  
Junichi Tsuyusaki ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Pulmonary Emphysema ◽  
Alveolar Epithelial Cells ◽  
Alveolar Cells ◽  
Alveolar Epithelial ◽  
Cd40 Stimulation ◽  
Ifn Γ ◽  
Apoptosis And Inflammation

Excessive apoptosis and prolonged inflammation of alveolar cells are associated with the pathogenesis of pulmonary emphysema. We aimed to determine whether CD40 affects alveolar epithelial cells and endothelial cells, with regard to evoking apoptosis and inflammation. Mice were repeatedly treated with agonistic-anti CD40 antibody (Ab), with or without agonistic-anti Fas Ab, and evaluated for apoptosis and inflammation in lungs. Human pulmonary microvascular endothelial cells and alveolar epithelial cells were treated with agonistic anti-CD40 Ab and/or anti-Fas Ab to see their direct effect on apoptosis and secretion of proinflammatory molecules in vitro. Furthermore, plasma soluble CD40 ligand (sCD40L) level was evaluated in patients with chronic obstructive pulmonary disease (COPD). In mice, inhaling agonistic anti-CD40 Ab induced moderate alveolar enlargement. CD40 stimulation, in combination with anti-Fas Ab, induced significant emphysematous changes and increased alveolar cell apoptosis. CD40 stimulation also enhanced IFN-γ-mediated emphysematous changes, not via apoptosis induction, but via inflammation with lymphocyte accumulation. In vitro, Fas-mediated apoptosis was enhanced by CD40 stimulation and IFN-γ in endothelial cells and by CD40 stimulation in epithelial cells. CD40 stimulation induced secretion of CCR5 ligands in endothelial cells, enhanced with IFN-γ. Plasma sCD40L levels were significantly increased in patients with COPD, inversely correlating to the percentage of forced expiratory volume in 1 s and positively correlating to low attenuation area score by CT scan, regardless of smoking history. Collectively CD40 plays a contributing role in the development of pulmonary emphysema by sensitizing Fas-mediated apoptosis in alveolar cells and increasing the secretion of proinflammatory chemokines.

Disparate cytokine regulation of ICAM-1 in rat alveolar epithelial cells and pulmonary endothelial cells in vitro

1995 ◽  
Vol 269 (1) ◽  
pp. L127-L135 ◽  
Author(s):  
W. W. Barton ◽  
S. Wilcoxen ◽  
P. J. Christensen ◽  
R. Paine
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Inflammatory Cytokines ◽  
Alveolar Epithelial Cells ◽  
Normal Lung ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

Intercellular adhesion molecule-1 (ICAM-1) is expressed at high levels on type I alveolar epithelial cells in the normal lung and is induced in vitro as type II cells spread in primary culture. In contrast, in most nonhematopoetic cells ICAM-1 expression is induced in response to inflammatory cytokines. We have formed the hypothesis that the signals that control ICAM-1 expression in alveolar epithelial cells are fundamentally different from those controlling expression in most other cells. To test this hypothesis, we have investigated the influence of inflammatory cytokines on ICAM-1 expression in isolated type II cells that have spread in culture and compared this response to that of rat pulmonary artery endothelial cells (RPAEC). ICAM-1 protein, determined both by a cell-based enzyme-linked immunosorbent assay and by Western blot analysis, and mRNA were minimally expressed in unstimulated RPAEC but were significantly induced in a time- and dose-dependent manner by treatment with tumor necrosis factor-alpha, interleukin-1 beta, or interferon-gamma. In contrast, these cytokines did not influence the constitutive high level ICAM-1 protein expression in alveolar epithelial cells and only minimally affected steady-state mRNA levels. ICAM-1 mRNA half-life, measured in the presence of actinomycin D, was relatively long at 7 h in alveolar epithelial cells and 4 h in RPAEC. The striking lack of response of ICAM-1 expression by alveolar epithelial cells to inflammatory cytokines is in contrast to virtually all other epithelial cells studied to date and supports the hypothesis that ICAM-1 expression by these cells is a function of cellular differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Characterization of Early Stages of Human Alveolar Infection by the Q Fever AgentCoxiella burnetii

2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Amanda L. Dragan ◽  
Richard C. Kurten ◽  
Daniel E. Voth
Keyword(s):  
Epithelial Cells ◽  
Lung Tissue ◽  
Alveolar Macrophages ◽  
Human Lung ◽  
Q Fever ◽  
Cell Types ◽  
Alveolar Epithelial Cells ◽  
Human Lung Tissue ◽  
Content Type ◽  
Alveolar Epithelial

ABSTRACTHuman Q fever is caused by the intracellular bacterial pathogenCoxiella burnetii. Q fever presents with acute flu-like and pulmonary symptoms or can progress to chronic, severe endocarditis. After human inhalation,C. burnetiiis engulfed by alveolar macrophages and transits through the phagolysosomal maturation pathway, resisting the acidic pH of lysosomes to form a parasitophorous vacuole (PV) in which to replicate. Previous studies showed thatC. burnetiireplicates efficiently in primary human alveolar macrophages (hAMs) inex vivohuman lung tissue. AlthoughC. burnetiireplicates in most cell typesin vitro, the pathogen does not grow in non-hAM cells of human lung tissue. In this study, we investigated the interaction betweenC. burnetiiand other pulmonary cell types apart from the lung environment.C. burnetiiformed a prototypical PV and replicated efficiently in human pulmonary fibroblasts and in airway, but not alveolar, epithelial cells. Atypical PV expansion in alveolar epithelial cells was attributed in part to defective recruitment of autophagy-related proteins. Further assessment of theC. burnetiigrowth niche showed that macrophages mounted a robust interleukin 8 (IL-8), neutrophil-attracting response toC. burnetiiand ultimately shifted to an M2-polarized phenotype characteristic of anti-inflammatory macrophages. Considering our findings together, this study provides further clarity on the uniqueC. burnetii-lung dynamic during early stages of human acute Q fever.

scholarly journals Lectin binding patterns to terminal sugars of rat lung alveolar epithelial cells.

1990 ◽  
Vol 38 (2) ◽  
pp. 233-244 ◽  
Author(s):  
D J Taatjes ◽  
L A Barcomb ◽  
K O Leslie ◽  
R B Low
Keyword(s):  
Epithelial Cells ◽  
Lectin Binding ◽  
Alveolar Epithelial Cells ◽  
Gold Complex ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Rat Lung ◽  
Alveolar Epithelial ◽  
I Cells

We used post-embedding cytochemical techniques to investigate the lectin binding profiles of rat lung alveolar epithelial cells. Sections from rat lung embedded in the hydrophilic resin Lowicryl K4M were incubated either directly with a lectin-gold complex or with an unlabeled lectin followed by a specific glycoprotein-gold complex. The binding patterns of the five lectins used could be divided into three categories according to their reactivity with alveolar epithelial cells: (a) the Limax flavus lectin and Ricinus communis I lectin bound to both type I and type II cell plasma membranes; (b) the Helix pomatia lectin and Sambucus nigra L. lectin bound to type II but not type I cells; and (c) the Erythrina cristagalli lectin reacted with type I cells but was unreactive with type II cells. The specificity of staining was assessed by control experiments, including pre-absorption of the lectins with various oligosaccharides and enzymatic pre-treatment of sections with highly purified glycosidases to remove specific sugar residues. The results demonstrate that these lectins can be used to distinguish between type I and type II cells and would therefore be useful probes for investigating cell dynamics during lung development and remodeling.

scholarly journals Proteolytic release of the receptor for advanced glycation end products from in vitro and in situ alveolar epithelial cells

2011 ◽  
Vol 300 (4) ◽  
pp. L516-L525 ◽  
Author(s):  
Naoko Yamakawa ◽  
Tokujiro Uchida ◽  
Michael A. Matthay ◽  
Koshi Makita
Keyword(s):  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
Alveolar Epithelial Cells ◽  
Advanced Glycation ◽  
Alveolar Epithelial ◽  
Lps Challenge ◽  
Soluble Rage ◽  
Glycation End Products ◽  
End Products

Although the receptor for advanced glycation end products (RAGE) has been used as a biological marker of alveolar epithelial cell injury in clinical studies, the mechanism for release of soluble RAGE from lung epithelial cells has not been well studied. Therefore, these studies were designed to determine the mechanism for release of soluble RAGE after lipopolysaccharide (LPS) challenge. For these purposes, alveolar epithelial cells from rat lungs were cultured on Transwell inserts, and LPS was added to the apical side (500 μg/ml) for 16 h on day 7. On day 7, RAGE was expressed predominantly in surfactant protein D-negative cells, and LPS challenge induced release of RAGE into the medium. This response was partially blocked by matrix metalloproteinase (MMP) inhibitors. Transcripts of MMP-3 and MMP-13 were upregulated by LPS, whereas RAGE transcripts did not change. Proteolysis by MMP-3 and MMP-13 resulted in soluble RAGE expression in the bronchoalveolar lavage fluid in the in situ rat lung, and this reaction was inhibited by MMP inhibitors. In human studies, both MMP-3 and -13 antigen levels were significantly correlated with the level of RAGE in pulmonary edema fluid samples. These results support the conclusion that release of RAGE is primarily mediated by proteolytic damage in alveolar epithelial cells in the lung, caused by proteases in acute inflammatory conditions in the distal air spaces.

scholarly journals Enhancement of alveolar epithelial sodium channel activity with decreased cystic fibrosis transmembrane conductance regulator expression in mouse lung

2011 ◽  
Vol 301 (4) ◽  
pp. L557-L567 ◽  
Author(s):  
Ahmed Lazrak ◽  
Asta Jurkuvenaite ◽  
Lan Chen ◽  
Kim M. Keeling ◽  
James F. Collawn ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Transmembrane Conductance Regulator ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Alveolar Epithelial ◽  
Cystic Fibrosis Transmembrane

We sought to establish whether the cystic fibrosis transmembrane conductance regulator (CFTR) regulates the activity of amiloride-sensitive sodium channels (ENaC) in alveolar epithelial cells of wild-type, heterozygous ( Cftr +/−), knockout ( Cftr −/−), and ΔF508-expressing mice in situ. RT-PCR studies confirmed the presence of CFTR message in freshly isolated alveolar type II (ATII) cells from wild-type mice. We patched alveolar type I (ATI) and ATII cells in freshly prepared lung slices from these mice and demonstrated the presence of 4-pS ENaC channels with the following basal open probabilities (Po): wild-type=0.21 ± 0.015: Cftr +/−=0.4 ± 0.03; ΔF508=0.55 ± 0.01; and Cftr −/−=and 0.81 ± 0.016 (means ± SE; n ≥ 9). Forskolin (5 μM) or trypsin (2 μM), applied in the pipette solution, increased the Po and number of channels in ATII cells of wild-type, Cftr +/−, and ΔF508, but not in Cftr −/− mice, suggesting that the latter were maximally activated. Western blot analysis showed that lungs of all groups of mice had similar levels of α-ENaC; however, lungs of Cftr +/− and Cftr −/− mice had significantly higher levels of an α-ENaC proteolytic fragment (65 kDa) that is associated with active ENaC channels. Our results indicate that ENaC activity is inversely correlated to predicted CFTR levels and that CFTR heterozygous and homozygous mice have higher levels of proteolytically processed ENaC fragments in their lungs. This is the first demonstration of functional ENaC-CFTR interactions in alveolar epithelial cells in situ.

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