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

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.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8514 ◽  
Author(s):  
Yanni Gui ◽  
Jian Sun ◽  
Wenjie You ◽  
Yuanhui Wei ◽  
Han Tian ◽  
...  

Background Epithelial-mesenchymal transition (EMT) plays an important role in fibrosis, chronic inflammation, tumor metastasis, etc. Glycyrrhizin, an active component extracted from licorice plant, has been reported to treat a variety of inflammatory reactions through inhibiting high-mobility group box1 (HMGB1), which has been suggested to be a significant mediator in EMT process. However, whether glycyrrhizin affects the EMT process or not remains unclear. Methods Human alveolar epithelial cell line A549 and normal human bronchial epithelial cell line BEAS-2B were treated with extrinsic TGF-β1 to induce EMT. Elisa was used to detect HMGB1 concentrations in cell supernatant. RNA interference and lentivirus infection experiments were performed to investigate the involvement of HMGB1 in EMT process. Cell Counting Kit-8 (CCK-8) was used to detect the viability of A549 and BEAS-2B cells treated with glycyrrhizin. Finally, the effects of glycyrrhizin on EMT changes, as well as the underlying mechanisms, were evaluated via Western blot, immunofluorescence and transwell assays. Results Our results showed that HMGB1 expression was increased by TGF-β1, and knockdown of HMGB1 expression reversed TGF-β1-induced EMT in A549 and BEAS-2B cells. Ectopic HMGB1 expression or TGF-β1 treatment caused a significant increase in HMGB1 release. Notably, we found that glycyrrhizin treatment effectively suppressed TGF-β1-induced EMT process by inhibiting HMGB1. Also, glycyrrhizin significantly inhibited the migration of both A549 and BEAS-2B cells promoted by TGF-β1. Mechanistically, HMGB1 overexpression could activate Smad2/3 signaling in A549 and BEAS-2B cells. Glycyrrhizin significantly blocked the phosphorylation of Smad2/3 stimulated either by TGF-β1 or by ectopic HMGB1 in A549 and BEAS-2B cells. Conclusions HMGB1 is a vital mediator of EMT changes induced by TGF-β1 in lung epithelial cells. Importantly, glycyrrhizin can effectively block Smad2/3 signaling pathway through inhibiting HMGB1, thereby suppressing the EMT progress.


2005 ◽  
Vol 79 (15) ◽  
pp. 10083-10087 ◽  
Author(s):  
Yee-Joo Tan ◽  
Puay-Yoke Tham ◽  
Daphne Z. L. Chan ◽  
Chih-Fong Chou ◽  
Shuo Shen ◽  
...  

ABSTRACT Here we analyzed the gene expression profile of cells that stably express the severe acute respiratory syndrome coronavirus (SARS-CoV) 3a protein to determine its effects on host functions. A lung epithelial cell-line, A549, was chosen for this study because the lung is the primary organ infected by SARS-CoV and fatalities resulted mainly from pulmonary complications. Our results showed that the expression of 3a up-regulates the mRNA levels of all three subunits, Aα, Bβ, and γ, of fibrinogen. Consequently, the intracellular levels as well as the secretion of fibrinogen were increased. We also observed increased fibrinogen levels in SARS-CoV-infected Vero E6 cells.


1992 ◽  
Vol 263 (1) ◽  
pp. L137-L141 ◽  
Author(s):  
J. H. Wilkens ◽  
A. Becker ◽  
H. Wilkens ◽  
M. Emura ◽  
M. Riebe-Imre ◽  
...  

Epithelium-derived factors of unknown identity have been proposed to modulate airway smooth muscle tone. We developed a novel sensitive bioassay system that allows serial perfusion of cultured respiratory epithelial cells and guinea pig trachea (GPT). GPT responses were assessed as diameter changes by computerized video microscopy (resolution, 15 microns). A permanent hamster lung epithelial cell line was grown on microcarrier beads and perfused in a cell column. When the outflow tubing from the epithelial cell column was connected to the inflow cannula, the detector GPT contracted, reaching 28 +/- 6% of the maximum methacholine (100 microM)-induced contraction (n = 12, P less than 0.001). Perfusion of the cell column with diclofenac (10 microM) or lysin-mono-acetylsalicylic acid (100 microM) abolished the GPT contraction, whereas selective perfusion of the detector GPT with either agent did not block the contraction. Analysis of the effluent of the epithelial cell column demonstrated a significant basal release of prostaglandins F2 alpha and E2 (PGF2 alpha and PGE2) and 6-ketoprostaglandin F1 alpha, whereas only marginal amounts of thromboxane B2 were detected. When given exogenously, PGF2 alpha, PGE2, PGI2, and U-46619 all contracted the GPT. It is concluded that lung epithelial cells can contract GPT by releasing a transferable factor. This factor is likely to be a constrictor cyclooxygenase product that is not produced in epithelium-denuded GPT.


2007 ◽  
Vol 293 (5) ◽  
pp. L1208-L1218 ◽  
Author(s):  
Ewa Ostrowska ◽  
Elena Sokolova ◽  
Georg Reiser

Protease-activated receptors (PARs) are involved in the contribution of airway epithelial cells to the development of inflammation by release of pro- and anti-inflammatory mediators. Here, we evaluated in epithelial cells the influence of LPS and continuous PAR activation on PAR expression level and the release of the proinflammatory chemokine IL-8. We studied primary human small airway epithelial cells and two airway epithelial cell lines, A549 and HBE cells. LPS specifically upregulated expression of PAR-2 but not of PAR-1. Exposure of epithelial cells to PAR-1 or PAR-2 agonists increased the PAR-1 expression level. The PAR-2 agonist exhibited higher potency than PAR-1 activators. However, the combined exposure of epithelial cells to LPS and PAR agonists abrogated the PAR-1 upregulation. The PAR-2 expression level was also upregulated after exposure to PAR-1 or PAR-2 agonists. This elevation was higher than the effect of PAR agonists on the PAR-1 level. In contrast to the PAR-1 level, the PAR-2 level remained elevated under concomitant stimulation with LPS and PAR-2 agonist. Furthermore, activation of PAR-2, but not of PAR-1, caused production of IL-8 from the epithelial cells. Interestingly, both in the epithelial cell line and in primary epithelial cells, there was a potentiation of the stimulation of the IL-8 synthesis and release by PAR-2 agonist together with LPS. In summary, these results underline the important role of PAR-2 in human lung epithelial cells. Moreover, our study shows an intricate interplay between LPS and PAR agonists in affecting PAR regulation and IL-8 production.


2008 ◽  
Vol 76 (7) ◽  
pp. 2833-2842 ◽  
Author(s):  
Robin R. Craven ◽  
Joshua D. Hall ◽  
James R. Fuller ◽  
Sharon Taft-Benz ◽  
Thomas H. Kawula

ABSTRACT Francisella tularensis, a gram-negative facultative intracellular bacterial pathogen, causes disseminating infections in humans and other mammalian hosts. Macrophages and other monocytes have long been considered the primary site of F. tularensis replication in infected animals. However, recently it was reported that F. tularensis also invades and replicates within alveolar epithelial cells following inhalation in a mouse model of tularemia. TC-1 cells, a mouse lung epithelial cell line, were used to study the process of F. tularensis invasion and intracellular trafficking within nonphagocytic cells. Live and paraformaldehyde-fixed F. tularensis live vaccine strain organisms associated with, and were internalized by, TC-1 cells at similar frequencies and with indistinguishable differences in kinetics. Inhibitors of microfilament and microtubule activity resulted in significantly decreased F. tularensis invasion, as did inhibitors of phosphatidylinositol 3-kinase and tyrosine kinase activity. Collectively, these results suggest that F. tularensis epithelial cell invasion is mediated by a preformed ligand on the bacterial surface and driven entirely by host cell processes. Once internalized, F. tularensis-containing endosomes associated with early endosome antigen 1 (EEA1) followed by lysosome-associated membrane protein 1 (LAMP-1), with peak coassociation frequencies occurring at 30 and 120 min postinoculation, respectively. By 2 h postinoculation, 70.0% (± 5.5%) of intracellular bacteria were accessible to antibody delivered to the cytoplasm, indicating vacuolar breakdown and escape into the cytoplasm.


2000 ◽  
Vol 23 (4) ◽  
pp. 485-491 ◽  
Author(s):  
Michael Kasper ◽  
Cora Roehlecke ◽  
Martin Witt ◽  
Heinz Fehrenbach ◽  
Andreas Hofer ◽  
...  

2014 ◽  
Vol 40 (5) ◽  
pp. 237-250 ◽  
Author(s):  
Aili Zhang ◽  
Xixin Yan ◽  
Honglin Li ◽  
Zhenfang Gu ◽  
Peng Zhang ◽  
...  

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