In utero nicotine exposure alters fetal rat lung alveolar type II cell proliferation, differentiation, and metabolism

2007 ◽  
Vol 292 (1) ◽  
pp. L323-L333 ◽  
Author(s):  
Virender K. Rehan ◽  
Ying Wang ◽  
Sharon Sugano ◽  
Jamie Santos ◽  
Sanjay Patel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
In Utero ◽  
Alveolar Type ◽  
Nicotine Exposure ◽  
Concomitant Treatment ◽  
Type Ii ◽  
Ppar Γ ◽  
Atii Cell ◽  
Surfactant Synthesis

We recently suggested that alveolar interstitial fibroblast-to-myofibroblast transdifferentiation may be a key mechanism underlying in utero nicotine-induced lung injury. However, the effects of in utero nicotine exposure on fetal alveolar type II (ATII) cells have not been fully determined. Placebo, nicotine (1 mg/kg), or nicotine (1 mg/kg) + the peroxisome proliferator-activated receptor (PPAR)-γ agonist prostaglandin J2 (PGJ2, 0.3 mg/kg) was administered intraperitoneally once daily to time-mated pregnant Sprague-Dawley rats from embryonic day 6 until their death on embryonic day 20. Fetal ATII cells were isolated, and ATII cell proliferation, differentiation (surfactant synthesis), and metabolism (metabolic profiling with the stable isotope [1,2-13C2]-d-glucose) were determined after nicotine exposure in utero or in vitro. In utero nicotine exposure significantly stimulated ATII cell proliferation, differentiation, and metabolism. Although the effects on ATII cell proliferation and metabolism were almost completely prevented by concomitant treatment with PGJ2, the effects on surfactant synthesis were not. On the basis of in utero and in vitro data, we conclude that surfactant synthesis is stimulated by nicotine's direct effect on ATII cells, whereas cell proliferation and metabolism are affected via a paracrine mechanism(s) secondary to its effects on the adepithelial fibroblasts. These data provide evidence for direct and indirect effects of in utero nicotine exposure on fetal ATII cells that could permanently alter the “developmental program” of the developing lung. More importantly, concomitant administration of PPAR-γ agonists can effectively attenuate many of the effects of in utero exposure to nicotine on ATII cells.

Inhibition of alveolar type II cell ATP and surfactant synthesis by nitric oxide

1996 ◽  
Vol 270 (6) ◽  
pp. L898-L906 ◽  
Author(s):  
I. Y. Haddad ◽  
S. Zhu ◽  
J. Crow ◽  
E. Barefield ◽  
T. Gadilhe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lipid Synthesis ◽  
Alveolar Epithelium ◽  
Alveolar Type ◽  
Type Ii ◽  
Surfactant Synthesis ◽  
Cell Energy ◽  
Type Ii Cell

Alveolar type II (ATII) cells, are often exposed to increased concentration of endogenous and exogenous nitric oxide (.NO). Exposure of freshly isolated rat ATII cells for 2 h to 1-3 microM .NO, generated by S-nitroso-N-penicillamine (SNAP), spermine NONOate, or 3-morpholino-sydnonimine (SIN-1) in the presence of superoxide dismutase, resulted in approximately 60% decrease in the rate of surfactant synthesis, as measured by the rate of incorporation of [methyl-3H]choline into phosphatidylcholine, and 60-80% inhibition of cellular ATP levels, as determined by bioluminescence. Similar results were obtained after incubation of ATII cells with authentic peroxynitrite (0.5 mM) but not SIN-1, a putative generator of peroxynitrite. Addition into the medium of oxyhemoglobin (20 microM), which scavenged .NO, or enhancement of ATII glutathione levels by preincubation with glutathione ester (5 mM) totally prevented the NONOate (100 microM) inhibition of cellular ATP. In contrast to the in vitro findings, normal levels of ATP and lipid synthesis were measured in ATII cells isolated from the lungs of rats that breathed .NO gas (80 ppm) in 21% O2 for 2 h (n = 4). This lack of effect may be due either to the presence of various antioxidants (such as glutathione) in the epithelial lining fluid or to the relatively low concentrations of .NO reaching the alveolar epithelium. We conclude that .NO and peroxynitrite, at concentrations likely to be encountered in vivo during inflammation, decrease ATII cell energy stores and surfactant synthesis, which may lead to derangement of important physiological functions.

Activation of HGF/c-Met signaling by ultrafine carbon particles and its contribution to alveolar type II cell proliferation

2012 ◽  
Vol 302 (8) ◽  
pp. L755-L763 ◽  
Author(s):  
Chih-Ching Chang ◽  
Jia-Jhen Chiu ◽  
Shan-Ling Chen ◽  
Hui-Chun Huang ◽  
Hui-Fen Chiu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Kinase Inhibitor ◽  
Carbon Particle ◽  
Alveolar Type ◽  
Type Ii ◽  
Type Ii Cell ◽  
Met Phosphorylation

Hepatocyte growth factor (HGF) is a potent mitogen and motogen for various epithelial cells. The present study aimed to explore the role of HGF and c-Met receptor in ultrafine carbon particle-induced alveolar type II epithelial (type II) cell proliferation. ICR mice were intratracheally instilled with 100 μg ultrafine carbon black (ufCB) and killed at 21, 48, and 72 days postexposure to examine type II cell proliferation, HGF release, and c-Met activation. In vivo and in vitro applications of neutralizing anti-HGF antibody were used to investigate the causal role of HGF in cell proliferation. The Met kinase inhibitor SU11274 and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 were used to delineate the involvement of c-Met/ERK1/2 in rat L2 pulmonary epithelial cell proliferation. The results demonstrated that in vivo exposure to 100 μg ufCB caused increased HGF in bronchoalveolar lavage fluid, as well as increased HGF production, c-Met phosphorylation, and cell proliferation in type II cells. In vitro study revealed that ufCB caused a dose-dependent increase in HGF release, c-Met phosphorylation, and cell proliferation. Importantly, treatment with the neutralizing anti-HGF antibody significantly blocked ufCB-induced in vivo and in vitro type II cell proliferation. Moreover, SU11274 and PD98059 significantly reduced ufCB-increased L2 cell proliferation. Results from Western blotting demonstrated that SU11274 successfully suppressed ufCB-induced phosphorylation of c-Met and ERK1/2. In summary, the activation of HGF/c-Met signaling is a major pathway involved in ufCB-induced type II cell proliferation.

In vitro time- and dose-effect response of JP-8 and S-8 jet fuel on alveolar type II epithelial cells of rats

2010 ◽  
Vol 26 (6) ◽  
pp. 367-374 ◽  
Author(s):  
Tiffany M Robb ◽  
Michael J Rogers ◽  
Suann S Woodward ◽  
Simon S Wong ◽  
Mark L Witten
Keyword(s):  
Epithelial Cells ◽  
Jet Fuel ◽  
Dose Effect ◽  
Alveolar Type ◽  
Type Ii

Differential susceptibilities of isolated hamster lung cell types to amiodarone toxicity

1998 ◽  
Vol 76 (7-8) ◽  
pp. 721-727 ◽  
Author(s):  
M W Bolt ◽  
W J Racz ◽  
J F Brien ◽  
T M Bray ◽  
T E Massey
Keyword(s):  
Alveolar Macrophages ◽  
Gradient Centrifugation ◽  
Cell Types ◽  
Clara Cell ◽  
Blue Dye ◽  
Alveolar Type ◽  
Specific Cell ◽  
Type Ii ◽  
Clara Cells

Treatment of cardiac dysrhythmias with the iodinated benzofuran derivative amiodarone (AM) is limited by pulmonary toxicity. The susceptibilities of different lung cell types of male Golden Syrian hamsters to AM-induced cytotoxicity were investigated in vitro. Bronchoalveolar lavage and protease digestion to release cells, followed by centrifugal elutriation and density gradient centrifugation, resulted in preparations enriched with alveolar macrophages (98%), alveolar type II cells (75-85%), and nonciliated bronchiolar epithelial (Clara) cells (35-50%). Alveolar type II cell and Clara cell preparations demonstrated decreased viability (by 0.5% trypan blue dye exclusion) when incubated with 50 µM AM for 36 h, and all AM-treated cell preparations demonstrated decreased viability when incubated with 100 or 200 µM AM. Based on a viability index ((viability of AM-treated cells ÷ viability of controls) × 100%), the Clara cell fraction was significantly (p < 0.05) more susceptible than all of the other cell types to 50 µM AM. However, AM cytotoxicity was greatest (p < 0.05) in alveolar macrophages following incubation with 100 or 200 µM AM. There was no difference between any of the enriched cell preparations in the amount of drug accumulated following 24 h of incubation with 50 µM AM, whereas alveolar macrophages accumulated the most drug during incubation with 100 µM AM. Thus, the most susceptible cell type was dependent on AM concentration. AM-induced cytotoxicity in specific cell types may initiate processes leading to inflammation and pulmonary fibrosis.Key words: amiodarone, susceptibility, alveolar macrophage, accumulation.

Fluid transport across cultured rat alveolar epithelial cells: a novel in vitro system

2004 ◽  
Vol 287 (1) ◽  
pp. L104-L110 ◽  
Author(s):  
Xiaohui Fang ◽  
Yuanlin Song ◽  
Rachel Zemans ◽  
Jan Hirsch ◽  
Michael A. Matthay
Keyword(s):  
Epithelial Cells ◽  
Fluid Transport ◽  
Alveolar Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Morphological Evidence ◽  
Alveolar Type ◽  
Type Ii ◽  
In Vitro System ◽  
Alveolar Epithelial

Previous studies have used fluid-instilled lungs to measure net alveolar fluid transport in intact animal and human lungs. However, intact lung studies have two limitations: the contribution of different distal lung epithelial cells cannot be studied separately, and the surface area for fluid absorption can only be approximated. Therefore, we developed a method to measure net vectorial fluid transport in cultured rat alveolar type II cells using an air-liquid interface. The cells were seeded on 0.4-μm microporous inserts in a Transwell system. At 96 h, the transmembrane electrical resistance reached a peak level (1,530 ± 115 Ω·cm2) with morphological evidence of tight junctions. We measured net fluid transport by placing 150 μl of culture medium containing 0.5 μCi of 131I-albumin on the apical side of the polarized cells. Protein permeability across the cell monolayer, as measured by labeled albumin, was 1.17 ± 0.34% over 24 h. The change in concentration of 131I-albumin in the apical fluid was used to determine the net fluid transported across the monolayer over 12 and 24 h. The net basal fluid transport was 0.84 μl·cm−2·h−1. cAMP stimulation with forskolin and IBMX increased fluid transport by 96%. Amiloride inhibited both the basal and stimulated fluid transport. Ouabain inhibited basal fluid transport by 93%. The cultured cells retained alveolar type II-like features based on morphologic studies, including ultrastructural imaging. In conclusion, this novel in vitro system can be used to measure net vectorial fluid transport across cultured, polarized alveolar epithelial cells.

scholarly journals Expression of highly selective sodium channels in alveolar type II cells is determined by culture conditions

2001 ◽  
Vol 280 (4) ◽  
pp. L646-L658 ◽  
Author(s):  
Lucky Jain ◽  
Xi-Juan Chen ◽  
Semra Ramosevac ◽  
Lou Ann Brown ◽  
Douglas C. Eaton
Keyword(s):  
Single Channel ◽  
Apical Membrane ◽  
Culture Conditions ◽  
Alveolar Type ◽  
Type Ii ◽  
Biophysical Properties ◽  
Air Interface ◽  
The Individual ◽  
Permeable Supports

Alveolar fluid clearance in the developing and mature lungs is believed to be mediated by some form of epithelial Na channels (ENaC). However, single-channel studies using isolated alveolar type II (ATII) cells have failed to demonstrate consistently the presence of highly selective Na+ channels that would be expected from ENaC expression. We postulated that in vitro culture conditions might be responsible for alterations in the biophysical properties of Na+conductances observed in cultured ATII cells. When ATII cells were grown on glass plates submerged in media that lacked steroids, the predominant channel was a 21-pS nonselective cation channel (NSC) with a Na+-to-K+ selectivity of 1; however, when grown on permeable supports in the presence of steroids and air interface, the predominant channel was a low-conductance (6.6 ± 3.4 pS, n = 94), highly Na+-selective channel (HSC) with a P Na/ P K >80 that is inhibited by submicromolar concentrations of amiloride ( K 0.5 = 37 nM) and is similar in biophysical properties to ENaC channels described in other epithelia. To establish the relationship of this HSC channel to the cloned ENaC, we employed antisense oligonucleotide methods to inhibit the individual subunit proteins of ENaC (α, β, and γ) and used patch-clamp techniques to determine the density of this channel in apical membrane patches of ATII cells. Overnight treatment of cells with antisense oligonucleotides to any of the three subunits of ENaC resulted in a significant decrease in the density of HSC channels in the apical membrane cell-attached patches. Taken together, these results show that when grown on permeable supports in the presence of steroids and air interface, the predominant channels expressed in ATII cells have single-channel characteristics resembling channels that are associated with the coexpression of the three cloned ENaC subunits α-, β-, and γ-ENaC.

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.

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