scholarly journals Phospholipid synthesis in isolated alveolar type II cells exposed in vitro to paraquat and hyperoxia

1987 ◽  
Vol 245 (1) ◽  
pp. 119-126 ◽  
Author(s):  
H P Haagsman ◽  
E A J M Schuurmans ◽  
J J Batenburg ◽  
L M Van Golde
Keyword(s):  
Lipid Metabolism ◽  
Neutral Lipids ◽  
Lipid Synthesis ◽  
Gas Diffusion ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Acetate Incorporation ◽  
Type Ii ◽  
Alveolar Type Ii Cells

Isolated alveolar epithelial type II cells were exposed to paraquat and to hyperoxia by gas diffusion through the thin Teflon bottom of culture dishes. After exposure, type II cells were further incubated in the presence of labelled substrates to assess their capacity to synthesize lipids. Hyperoxia alone (90% O2; 5 h) had minor effects on lipid metabolism in the type II cells. At low paraquat concentrations (5 and 10 microM), hyperoxia enhanced the paraquat-induced decrease of [Me-14C]choline incorporation into phosphatidylcholines. The incorporation rates of [Me-14C]choline, [1-14C]palmitate, [1-14C]glucose and [1,3-3H]glycerol into various phospholipid classes and neutral lipids were decreased by paraquat, depending on the concentration and duration of the exposure. The incorporation of [1-14C]acetate into phosphatidylcholines, phosphatidylglycerols and neutral lipids appeared to be very sensitive to inactivation by paraquat. At 5 microM-paraquat the rate of [1-14C]acetate incorporation was decreased to 50% of the control values. The rate of [1-14C]palmitate incorporation into lipids was much less sensitive; it even increased at low paraquat concentrations. At 10 microM-paraquat both NADPH and ATP were significantly decreased. It is concluded that lipid synthesis in isolated alveolar type II cells is extremely sensitive to paraquat. At low concentrations of this herbicide, lipid synthesis, and particularly fatty acid synthesis, is decreased. The effects on lipid metabolism may be partly related to altered NADPH and ATP concentrations.

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.

Prevention of Paraquat Toxicity in Suspensions of Alveolar Type II Cells by Paraquat-Specific Antibodies

1994 ◽  
Vol 13 (8) ◽  
pp. 551-557 ◽  
Author(s):  
Nian Chen ◽  
Mark R. Bowles ◽  
Susan M. Pond
Keyword(s):  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Specific Antibodies ◽  
Fab Fragments ◽  
Paraquat Toxicity ◽  
Specific Igg ◽  
Energy Dependent

1 The herbicide, paraquat, is accumulated by the energy-dependent polyamine uptake pathway of alveolar type II cells. There it undergoes redox cycling that results in an amplified production of toxic reactive oxygen species and depletion of NADPH and other reducing equivalents. These processes account for the lung being the major target organ for paraquat toxicity. 2 We postulated that paraquat-specific antibodies would inhibit the uptake of the herbicide by type II cells and prevent its toxicity. Accordingly, we examined the effects of paraquat-specific monoclonal antibodies and Fab fragments on the uptake, efflux and cytotoxicity of 50 μM paraquat in suspensions of alveolar type II cells isolated from the rat. 3 The uptake of paraquat was linear over 40 min. Over this time, the uptake rate was inhibited significantly (% inhibition, 73-89) by IgG (25 or 50 μM) or Fab fragments (50 or 100 μM). 4 The apparent efflux rate of paraquat, studied over 16 h, was increased significantly from 0.12 h-1 for the control cells in medium to 0.17 h-1 by paraquat-specific Fab fragments but was unaffected by the specific IgG. 5 Cytotoxicity was determined by measuring the release of 51Cr from the cells. The cytotoxicity of 50 μM paraquat was decreased significantly (percent decrease, 56-80%) in the presence of specific antibodies. 6 These studies in vitro suggest some potential for immunotherapy in selected cases of paraquat poisoning.

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.

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.

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.

scholarly journals Pulmonary Surfactant Preserves Viability of Alveolar Type II Cells Exposed to Polymyxin B In Vitro

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e62105 ◽  
Author(s):  
Guido Stichtenoth ◽  
Egbert Herting ◽  
Mario Rüdiger ◽  
Andreas Wemhöner
Keyword(s):  
Pulmonary Surfactant ◽  
Polymyxin B ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells

Characterization of Rat Alveolar Type II Cells in vitro by Immunological, Biochemical, and Morphological Criteria

1986 ◽  
Vol 11 (4) ◽  
pp. 263-275 ◽  
Author(s):  
James B. McMahon ◽  
Adaline C. Smith ◽  
Anthony del Campo ◽  
Gurmukh Singh ◽  
Sikandar L. Katyal ◽  
...  
Keyword(s):  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Morphological Criteria

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.

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