scholarly journals A bilayer tissue culture model of the bovine alveolus

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 357
Author(s):  
Diane Lee ◽  
Mark Chambers
Keyword(s):  
Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Host Pathogen Interactions ◽  
Alveolar Type Ii Cells ◽  
Permeable Membrane ◽  
Host Pathogen

The epithelial lining of the lung is often the first point of interaction between the host and inhaled pathogens, allergens and medications. Epithelial cells are therefore the main focus of studies which aim to shed light on host-pathogen interactions, to dissect the mechanisms of local host immunity and study toxicology. If these studies are not to be conducted exclusively in vivo, it is imperative that in vitro models are developed with a high in vitro-in vivo correlation. We describe here a co-culture bilayer model of the bovine alveolus, designed to overcome some of the limitations encountered with mono-culture and live animal models. Our system includes bovine pulmonary arterial endothelial cells (BPAECs) seeded onto a permeable membrane in 24 well Transwell format. The BPAECs are overlaid with immortalised bovine alveolar type II epithelial cells and the bilayer cultured at air-liquid interface for 14 days before use; in our case to study host-mycobacterial interactions. Characterisation of novel cell lines and the bilayer model have provided compelling evidence that immortalised bovine alveolar type II cells are an authentic substitute for primary alveolar type II cells and their culture as a bilayer in conjunction with BPAECs provides a physiologically relevant in vitro model of the bovine alveolus.   The bilayer model may be used to study dynamic intracellular and extracellular host-pathogen interactions, using proteomics, genomics, live cell imaging, in-cell ELISA and confocal microscopy. The model presented in this article enables other researchers to establish an in vitro model of the bovine alveolus that is easy to set up, malleable and serves as a comparable alternative to in vivo models, whilst allowing study of early host-pathogen interactions, currently not feasible in vivo. The model therefore achieves one of the 3Rs objectives in that it replaces the use of animals in research of bovine respiratory diseases.

scholarly journals A co-culture model of the bovine alveolus

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 357 ◽  
Author(s):  
Diane Lee ◽  
Mark Chambers
Keyword(s):  
Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Host Pathogen Interactions ◽  
Alveolar Type Ii Cells ◽  
Culture Model ◽  
Host Pathogen

The epithelial lining of the lung is often the first point of interaction between the host and inhaled pathogens, allergens and medications. Epithelial cells are therefore the main focus of studies which aim to shed light on host-pathogen interactions, to dissect the mechanisms of local host immunity and study toxicology. If these studies are not to be conducted exclusively in vivo, it is imperative that in vitro models are developed with a high in vitro- in vivo correlation. We describe here a co-culture model of the bovine alveolus, designed to overcome some of the limitations encountered with mono-culture and live animal models. Our system includes bovine pulmonary arterial endothelial cells (BPAECs) seeded onto a permeable membrane in 24 well Transwell format. The BPAECs are overlaid with immortalised bovine alveolar type II epithelial cells and cultured at air-liquid interface for 14 days before use; in our case to study host-mycobacterial interactions. Characterisation of novel cell lines and the co-culture model have provided compelling evidence that immortalised bovine alveolar type II cells are an authentic substitute for primary alveolar type II cells and their co-culture with BPAECs provides a physiologically relevant in vitro model of the bovine alveolus.   The co-culture model may be used to study dynamic intracellular and extracellular host-pathogen interactions, using proteomics, genomics, live cell imaging, in-cell ELISA and confocal microscopy. The model presented in this article enables other researchers to establish an in vitro model of the bovine alveolus that is easy to set up, malleable and serves as a comparable alternative to in vivo models, whilst allowing study of early host-pathogen interactions, currently not feasible in vivo. The model therefore achieves one of the 3Rs objectives in that it replaces the use of animals in research of bovine respiratory diseases.

Differential Effects of Halothane and Thiopental on Surfactant Protein C Messenger RNA  In Vivo and  In Vitro in Rats 

2000 ◽  
Vol 93 (3) ◽  
pp. 805-810 ◽  
Author(s):  
Catherine Paugam-Burtz ◽  
Serge Molliex ◽  
Bernard Lardeux ◽  
Corinne Rolland ◽  
Michel Aubier ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Protein C ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Mechanically Ventilated ◽  
Mrna Content

Background Pulmonary surfactant is a complex mixture of proteins and phospholipids synthetized by alveolar type II cells. Volatile anesthetics have been shown to reduce surfactant phospholipid biosynthesis by rat alveolar type II cells. Surfactant-associated protein C (SP-C) is critical for the alveolar surfactant functions. Our goal was to evaluate the effects of halothane and thiopental on SP-C messenger RNA (mRNA) expression in vitro in rat alveolar type II cells and in vivo in mechanically ventilated rats. Methods In vitro, freshly isolated alveolar type II cells were exposed to halothane during 4 h (1, 2, 4%) and 8 h (1%), and to thiopental during 4 h (10, 100 micrometer) and 8 h (100 micrometer). In vivo, rats were anesthetized with intraperitoneal thiopental or inhaled 1% halothane and mechanically ventilated for 4 or 8 h. SP-C mRNA expression was evaluated by ribonuclease protection assay. Results In vitro, 4-h exposure of alveolar type II cells to thiopental 10 and 100 micrometer increased their SP-C mRNA content to 145 and 197%, respectively, of the control values. In alveolar type II cells exposed for 4 h to halothane 1, 2, and 4%, the SP-C mRNA content increased dose-dependently to 160, 235, and 275%, respectively, of the control values. In vivo, in mechanically ventilated rats, 4 h of halothane anesthesia decreased the lung SP-C mRNA content to 53% of the value obtained in control (nonanesthetized, nonventilated) animals; thiopental anesthesia increased to 150% the lung SP-C mRNA content. Conclusions These findings indicate that halothane and thiopental used at clinically relevant concentrations modulate the pulmonary SP-C mRNA content in rats. In vivo, the additive role of mechanical ventilation is suggested.

Distinct effects of SP-B and SP-C on the uptake of surfactant-like liposomes by alveolar cells in vivo and in vitro

2004 ◽  
Vol 287 (5) ◽  
pp. L1056-L1065 ◽  
Author(s):  
D. L. H. Poelma ◽  
L. J. Zimmermann ◽  
W. A. van Cappellen ◽  
J. J. Haitsma ◽  
B. Lachmann ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Divalent Cations ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Cells ◽  
Alveolar Type Ii Cells ◽  
Lipid Ratio

The effects of surfactant protein B (SP-B) and SP-C on the uptake of surfactant-like liposomes by alveolar type II cells and alveolar macrophages were studied both in vivo and in vitro. In vivo, mechanically ventilated rats were intratracheally instilled with fluorescently labeled liposomes that had SP-B and/or SP-C incorporated in different concentrations. Consequently, the alveolar cells were isolated, and cell-associated fluorescence was determined using flow cytometry. The results show that the incorporation of SP-B does not influence the uptake, and it also does not in the presence of essential cofactors. The inclusion of SP-C in the liposomes enhanced the alveolar type II cells at a SP-C to lipid ratio of 2:100. If divalent cations (calcium and magnesium) were present at physiological concentrations in the liposome suspension, uptake of liposomes by alveolar macrophages was also enhanced. In vitro, the incorporation of SP-B affected uptake only at a protein-to-lipid ratio of 8:100, whereas the inclusion of SP-C in the liposomes leads to an increased uptake at a protein-to-lipid ratio of 1:100. From these results, it can be concluded that SP-B is unlikely to affect uptake of surfactant, whereas SP-C in combination with divalent cations and other solutes are capable of increasing the uptake.

Mechanisms of Surfactant Exocytosis in Alveolar Type II Cells In Vitro and In Vivo

Physiology ◽  
2001 ◽  
Vol 16 (5) ◽  
pp. 239-243 ◽  
Author(s):  
Paul Dietl ◽  
Thomas Haller ◽  
Norbert Mair ◽  
Manfred Frick
Keyword(s):  
Surface Tension ◽  
In Vitro Studies ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Surfactant Secretion

Surfactant secretion must be regulated to maintain a low surface tension in the lung during various conditions such as exercise. In vitro studies reveal a slow, unique exocytotic process at the interface of stimulated and constitutive exocytosis. The exocytotic mechanisms and sites of regulation in vivo, however, are still poorly understood.

In vivo and in vitro uptake of surfactant lipids by alveolar type II cells and macrophages

2002 ◽  
Vol 283 (3) ◽  
pp. L648-L654 ◽  
Author(s):  
D. L. H. Poelma ◽  
L. J. I. Zimmermann ◽  
H. H. Scholten ◽  
B. Lachmann ◽  
J. F. van Iwaarden
Keyword(s):  
Alveolar Macrophages ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Cells ◽  
Alveolar Type Ii Cells ◽  
Small Subpopulation

The uptake of fluorescent-labeled liposomes (with a surfactant-like composition) by alveolar macrophages and alveolar type II cells was studied using flow cytometry, in vivo by instillation of the labeled liposomes in the trachea of ventilated rats followed by isolation of the alveolar cells and determination of the cell-associated fluorescence, and in vitro by incubation of isolated alveolar cells with the fluorescent liposomes. The results show that the uptake of liposomes by the alveolar cells is time and concentration dependent. In vivo alveolar macrophages internalize more than three times as many liposomes as alveolar type II cells, whereas in vitro, the amount of internalized liposomes by these cells is approximately the same. In vitro, practically all the cells (70–75%) internalize liposomes, whereas in vivo only 30% of the alveolar type II cells ingest liposomes vs. 70% of the alveolar macrophages. These results indicate that in vivo, only a small subpopulation of alveolar type II cells is able to internalize surfactant liposomes.

scholarly journals IL-17A and TNF-α Exert Synergistic Effects on Expression of CXCL5 by Alveolar Type II Cells In Vivo and In Vitro

2011 ◽  
Vol 186 (5) ◽  
pp. 3197-3205 ◽  
Author(s):  
Yuhong Liu ◽  
Junjie Mei ◽  
Linda Gonzales ◽  
Guang Yang ◽  
Ning Dai ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Tnf Α

scholarly journals Effects of vascular endothelial growth factor on isolated fetal alveolar type II cells

2004 ◽  
Vol 286 (6) ◽  
pp. L1293-L1301 ◽  
Author(s):  
William Raoul ◽  
Bernadette Chailley-Heu ◽  
Anne-Marie Barlier-Mur ◽  
Christophe Delacourt ◽  
Bernard Maître ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Transcript Level ◽  
Alveolar Type ◽  
Vegf Receptor ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells

Previous investigations gained from in vivo or lung explant studies suggested that VEGF is an autocrine proliferation and maturation factor for developing alveolar type II cells. The objective of this work was to determine whether VEGF exerted its growth and maturation effects directly on isolated type II cells. These were isolated from 19-day fetal rat lung and cultured in defined medium. The presence of VEGF receptor-2 was assessed in cultured cells at the pre- and posttranslational levels. Recombinant VEGF165, formerly found to be active on lung explants, failed to enhance type II cell proliferation estimated by thymidine and 5-bromo-2′-deoxy-uridine incorporation. It increased choline incorporation in saturated phosphatidylcholine by 27% but did not increase phospholipid surfactant pool size. VEGF (100 ng/ml) left unchanged the transcript level of surfactant proteins (SP)-A, SP-C, and SP-D but increased SP-B transcripts to four times the control steady-state level. VEGF slightly retarded, but did not prevent, the in vitro transdifferentiation of type II into type I cells, as assessed by immunolabeling of the type I cell marker T1α. We conclude that, with the exception of SP-B expression, which appears to be controlled directly, the previously observed effects of this VEGF isoform on type II cells are likely to be exerted indirectly through reciprocal paracrine interactions involving other lung cell types.

Hypoxia decreases proteins involved in epithelial electrolyte transport in A549 cells and rat lung

2000 ◽  
Vol 279 (6) ◽  
pp. L1110-L1119 ◽  
Author(s):  
Ralf Wodopia ◽  
Hyun Soo Ko ◽  
Javiera Billian ◽  
Rudolf Wiesner ◽  
Peter Bärtsch ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Tissue ◽  
A549 Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Alveolar Epithelial

Fluid reabsorption from alveolar space is driven by active Na reabsorption via epithelial Na channels (ENaCs) and Na-K-ATPase. Both are inhibited by hypoxia. Here we tested whether hypoxia decreases Na transport by decreasing the number of copies of transporters in alveolar epithelial cells and in lungs of hypoxic rats. Membrane fractions were prepared from A549 cells exposed to hypoxia (3% O2) as well as from whole lung tissue and alveolar type II cells from rats exposed to hypoxia. Transport proteins were measured by Western blot analysis. In A549 cells, α1- and β1-Na-K-ATPase, Na/K/2Cl cotransport, and ENaC proteins decreased during hypoxia. In whole lung tissue, α1-Na-K-ATPase and Na/K/2Cl cotransport decreased. α- and β-ENaC mRNAs also decreased in hypoxic lungs. Similar results were seen in alveolar type II cells from hypoxic rats. These results indicate a slow decrease in the amount of Na-transporting proteins in alveolar epithelial cells during exposure to hypoxia that also occurs in vivo in lungs from hypoxic animals. The reduced number of transporters might account for the decreased transport activity and impaired edema clearance in hypoxic lungs.

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