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Lung Cells (lung + cell)

Distribution by Scientific Domains

Medical Sciences	66%
Life Sciences	27%

Selected Abstracts

Intracellular glutathione in stretch-induced cytokine release from alveolar type-2 like cells

RESPIROLOGY, Issue 1 2004
Behrouz Jafari
Objective: Ventilator-induced lung injury (VILI) is characterized by release of inflammatory cytokines, but the mechanisms are not well understood. We hypothesized that stretch-induced cytokine production is dependent on oxidant release and is regulated by intracellular glutathione (GSH) inhibition of nuclear factor ,B (NF-,B) and activator protein-1 (AP-1) binding. Methodology: Type 2-like alveolar epithelial cells (A549) were exposed to cyclic stretch at 15% strain for 4 h at 20 cycles/min with or without N-acetylcysteine (NAC) or glutathione monoethylester (GSH-e) to increase intracellular GSH, or buthionine sulfoximine (BSO), to deplete intracellular GSH. Results: Cyclic stretch initially caused a decline in intracellular GSH and a rise in the levels of isoprostane, a marker of oxidant injury. This was followed by a significant increase in intracellular GSH and a decrease in isoprostane. Stretch-induced IL-8 and IL-6 production were significantly inhibited when intracellular GSH was further increased by NAC or GSH-e (P < 0.0001). Stretch-induced IL-8 and IL-6 production were augmented when intracellular GSH was depleted by BSO (P < 0.0001). NAC blocked stretch-induced NF-,B and AP-1 binding and inhibited IL-8 mRNA expression. Conclusions: We conclude that oxidant release may play a role in lung cell stretch-induced cytokine release, and antioxidants, which increase intracellular GSH, may protect lung cells against stretch-induced injury. [source]

Contractile activity of skeletal musculature involved in breathing is essential for normal lung cell differentiation, as revealed in Myf5,/,:MyoD,/, embryos

DEVELOPMENTAL DYNAMICS, Issue 3 2005
Mohammad Reza Inanlou
Abstract In the current study, the role of contractile activity of respiratory muscles in fetal lung growth and cell differentiation was examined using Myf5,/,:MyoD,/, mouse embryos. As previously found, Myf5,/,:MyoD,/, mouse embryos had no respiratory musculature. Consequently, they suffered from pulmonary hypoplasia and died shortly after birth. The hypoplastic lung had decreased proliferation and increased apoptotic index as early as embryonic day 14.5. By contrast, only at the last gestational day, the number of lung cells expressing platelet derived growth factor B and insulin growth factor I was decreased, while the gradient of the thyroid transcription factor 1 was not maintained. Type II pneumocytes had a failure in glycogen utilization and surfactant storage and secretion but were able to synthesize the surfactant-associated proteins. Type I pneumocytes were readily detectable using an early differentiation marker (i.e., Gp38). However, the late differentiation of type I pneumocytes never occurred, as revealed by transmission electron microscopy. Together, our findings suggest that pulmonary distension due to fetal breathing-like movements plays an important role not only in lung growth but also in lung cell differentiation. Developmental Dynamics 233:772,782, 2005. © 2005 Wiley-Liss, Inc. [source]

Timeless in lung morphogenesis

DEVELOPMENTAL DYNAMICS, Issue 1 2003
Jing Xiao
Abstract The Clock gene, timeless, regulates circadian rhythm in Drosophila, but its vertebrate homolog is critical to embryonic development. Timeless was shown to be involved in murine urethral bud branching morphogenesis. We generated a polyclonal antibody to mouse TIMELESS (mTIM) and studied its distribution and its potential role during lung development, which also requires branching morphogenesis. In the early mouse embryo, TIM was localized to all organs, especially the neural epithelium. In embryonic day (E) 9.5 embryos, TIM was present in both epithelial and mesenchymal cells at the onset of lung morphogenesis. In E15 embryos, TIM decreased in the mesenchyme but remained pronounced in the epithelium of both large and small airways. Later, TIM was localized to a specific subset of epithelial cells with alveolar type 2 phenotype. This finding was verified by immunostaining of isolated alveolar type 2 cells. In the proximal airways, TIM was colocalized with CCSP to nonciliated columnar epithelial cells. Antisense oligonucleotides to mTim specifically inhibited branching morphogenesis of embryonic lungs in explant culture without affecting SpC expression an alveolar type 2 cell marker. In cultured lung cells, expression of TIM is independent of cell cycle and proliferation. These studies indicate that the function of Timeless is highly conserved in organs whose formation requires branching morphogenesis. Developmental Dynamics 228:82,94, 2003. © 2003 Wiley-Liss, Inc. [source]

Nickel potentiates the genotoxic effect of benzo[a]pyrene in Chinese hamster lung V79 cells

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2006
Cheng Z. Deng
Abstract The modulating effect of acute exposure to NiCl2 on the induction of chromosome aberrations by a model carcinogen, benzo[a]pyrene (B[a]P), was examined in Chinese hamster V79 lung cells. At concentrations up to 20 ,g/ml (84.2 ,M), NiCl2 did not significantly increase the frequency of chromosome aberrations in V79 cells when the cells were exposed concomitantly to 0.5 ,g/ml B[a]P. Addition of the S15 liver microsomal fraction together with the B[a]P did not alter the results. Addition of NiCl2 2 hr before treatment of cells with 0.5 ,g/ml B[a]P also did not result in a significant elevation of the frequency of chromosome aberrations, even at NiCl2 concentrations as high as 20 ,g/ml. Contrasting sharply with these findings, when V79 cells were treated with NiCl2 immediately after B[a]P exposure, a significant increase in the frequency of chromosome damage was observed at NiCl2 concentrations as low as 5 ,g/ml (21.1 ,M). NiCl2 -mediated enhancement of chromosome damage was also observed when V79 cells were exposed to the reactive B[a]P intermediate, benzo[a]pyrene,r,7,t,8-dihydrodiol- t,9,10-epoxide (BPDE). In the BPDE-treated cells, the level of NiCl2 -mediated enhancement was similar to that observed with the tumor promoter 12- o -tetradecanoylphorbol-13-acetate (TPA, 100 ng/ml). These results are consistent with the view that the effect of nickel (II) on B[a]P-induced genetic damage is dependent on the relative times of exposure to Ni2+ and B[a]P. NiCl2 did not enhance the frequency of chromosome aberrations induced by Chromium (VI), regardless of the order of addition of the chemicals to the V79 cells. These results suggest that nickel may act as a promoter of chemically-induced genetic damage through induction of error-prone repair. Environ. Mol. Mutagen., 2006. © 2005 Wiley-Liss, Inc. [source]

Acute exposure of human lung cells to 1,3-butadiene diepoxide results in G1 and G2 cell cycle arrest

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2005
Michael Schmiederer
Abstract 1,3-butadiene (BD) causes genetic damage, including adduct formation, sister chomatid exchange, and point mutations. Previous studies have focused on the types of genetic damage and tumors found after long-term exposure of rodents to butadiene. This study examined the effect of the most active BD metabolite, butadiene diepoxide (BDO2), on cell cycle entry and progression in human lung fibroblasts (LU cells) with a normal diploid karyotype. Serum-arrested (G0) LU cells were exposed to BDO2 for 1 hr and stimulated to divide with medium containing 10% fetal bovine serum. The BDO2 -treated LU cells were evaluated for cell cycle progression, nuclear localization of arrest mediators, mitotic index, and cellular proliferation. The BDO2 -treated cells demonstrated a substantial inhibition of cell proliferation when treated with 100 ,M BDO2 for 1 hr. No appreciable levels of apoptosis or mitotic figures were observed in the BDO2 -treated cells through 96 hr posttreatment. Flow cytometric analysis revealed that the lack of proliferation in BDO2 -treated LU cells was related to G1 arrest in about half of the cells and a delayed progression through S and G2 arrest in nearly all of the remaining cells. Both G1 and G2 arrest were prolonged and only a very small percentage of BDO2 -treated cells were eventually able to replicate. Increased nuclear localization of both p53 and p21cip1 was observed in BDO2 -treated cells, suggesting that the cell cycle arrest was p21cip1 -mediated. These results demonstrate that BDO2 induces cell cycle perturbation and arrest even with short-term exposure that does not produce other pathologic cellular effects. Environ. Mol. Mutagen., 2005. © 2005 Wiley-Liss, Inc. [source]

Stem cells and pulmonary metamorphosis: New concepts in repair and regeneration

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2005
Jason M. Aliotta
Adult stem cells are likely to have much more versatile differentiation capabilities than once believed. Numerous studies have appeared over the past decade demonstrating the ability of adult stem cells to differentiate into a variety of cells from non-hematopoietic organs, including the lung. The goal of this review is to provide an overview of the growth factors which are thought to be involved in lung development and disease, describe the cells within the lung that are believed to replace cells that have been injured, review the studies that have demonstrated the transformation of bone marrow-derived stem cells into lung cells, and describe potential clinical applications with respect to human pulmonary disease. © 2005 Wiley-Liss, Inc. [source]

Absorption of polyethylene glycol (PEG) polymers: The effect of PEG size on permeability

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2009
Hema Gursahani
Abstract Polyethylene glycol (PEG) polymers are large amphiphilic molecules that are highly hydrated in solution. To explore the permeability properties of different sized PEG polymers across epithelial membranes in vivo, we examined the absorption of fluorescently labeled PEG conjugates sized 0.55,20 kDa from the lung, since this system provides a reservoir that limits rapid diffusion of molecules away from the site of delivery and enables permeability over longer times to be examined. Following intratracheal delivery in rats, the PEG polymers underwent absorption with first-order kinetics described by single exponential decay curves. PEG size produced a marked influence on the rate of uptake from the lung, with half-lives ranging from 2.4 to 13 h, although above a size of 5 kDa, no further change in rate was observed. PEG size likewise affected retention in alveolar macrophages and in lung tissue; whereas smaller PEG sizes (<2 kDa) were effectively cleared within 48 h, larger PEG sizes (>5 kDa) remained in lung cells and tissue for up to 7 days. These data demonstrate that PEG polymers can be absorbed across epithelial membranes and that PEG size plays a dominant role in controlling the rate and mechanism of absorption. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2847,2856, 2009 [source]

Piperine inhibits eosinophil infiltration and airway hyperresponsiveness by suppressing T cell activity and Th2 cytokine production in the ovalbumin-induced asthma model

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2009
Seung-Hyung Kim
Abstract Objectives This study aimed to investigate the effect of piperine on airway hyper-responsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production, immunoglobulin E and histamine production in a murine model of asthma. Methods Asthma was induced in Balb/c mice by ovalbumin sensitization and inhalation. Piperine (4.5 and 2.25 mg/kg) was orally administered 5 times a week for 8 weeks. At 1 day after the last ovalbumin exposure, airway hyperresponsiveness was determined and samples of bronchoalveolar lavage fluid, lung cells and serum were collected for further analysis. Key findings Piperine-treated groups had suppressed eosinophil infiltration, allergic airway inflammation and airway hyperresponsiveness, and these occurred by suppression of the production of interleukin-4, interleukin-5, immunoglobulin E and histamine. Moreover, polymerase chain reaction products for thymus and activation regulated chemokine from lung cell RNA preparations were decreased in the piperine-treated group compared with control groups, although transforming growth factor-, products were increased in the piperine-treated group. Conclusions The results suggest that the therapeutic mechanism by which piperine effectively treats asthma is based on a reduction of Th2 cytokines (interleukin-4, interleukin-5), eosinophil infiltration, and by marked reduction of thymus and activation regulated chemokine, eotaxin-2 and interleukin-13 mRNA expression (especially transcription of nuclear factor-, dependent genes) in lung tissue, as well as reduced interleukin-4, interleukin-5 and eotaxin levels in bronchoalveolar lavage fluid, and histamine and ovalbumin-specific immunoglobulin E production in serum. [source]

Nkx2.1 transcription factor in lung cells and a transforming growth factor-,1 heterozygous mouse model of lung carcinogenesis,

MOLECULAR CARCINOGENESIS, Issue 4 2004
Yang Kang
Abstract The Nkx2.1 homeobox gene and transforming growth factor-,1 (TGF-,1) are essential for organogenesis and differentiation of the mouse lung. NKX2.1 is a marker of human lung carcinomas, but it is not known whether this gene participates in early tumorigenesis. Addition of TGF-,1 to TGF-,1-responsive nontumorigenic mouse lung cells cotransfected with a NKX2.1Luc luciferase reporter and either a Sp1 or Sp3 plasmid showed a significant increase or decrease, respectively, in NKX2.1Luc transcription. Cotransfection of Sp3 and dominant-negative TGF-, type II receptor plasmids negated the effect of Sp1. Cotransfected Sp1 plasmid with either dominant-negative Smad2 or Smad3 or Smad4 plasmids significantly decreased NKX2.1Luc transcription. Electrophoretic mobility shift assays revealed binding of Sp1 and Smad4 to the NKX2.1 promoter. With a TGF-,1 heterozygous mouse model, Nkx2.1 mRNA and protein in lungs of TGF-,1 heterozygous mice were significantly lower compared to wildtype (WT) littermates. Competitive reverse transcription (RT)-polymerase chain reaction (PCR) and immunostaining showed that Nkx2.1 mRNA and protein decreased significantly in adenomas and adenocarcinomas compared to normal lung tissue. Our in vitro data showed that regulation of Nkx2.1 by TGF-,1 occurs through TGF-, type II receptor and Smad signaling, with Sp1 and Sp3 in lung cells. Our in vivo data showed reduced Nkx2.1 in lungs of TGF-,1 heterozygous mice compared to WT mice, that is detectable in adenomas, and that is further reduced in carcinogenesis, and that correlates with reduction of Sp1, Sp3, and Smads in lung adenocarcinomas. Our findings suggest that reduced Nkx2.1 and TGF-,1 signaling components may contribute to tumorigenesis in the lungs of TGF-,1 heterozygous mice. Published 2004 Wiley-Liss, Inc. [source]

Mechanical ventilation with high tidal volume or frequency is associated with increased expression of nerve growth factor and its receptor in rabbit lungs

PEDIATRIC PULMONOLOGY, Issue 7 2009
Rashmi A. Mittal MD
Abstract Objective Nerve growth factor (NGF), a neurotrophin, is induced in lung cells by proinflammatory cytokines, and has a role in bronchial hyperreactivity and lung tissue repair. Ventilation induced lung injury, on the other hand, is known to increase the levels of proinflammatory cytokines in the lungs. We investigated whether, and to what extent, various degrees of lung injury induced by short-term ventilation affect NGF levels in the lung tissue of adolescent rabbits. Methods The rabbits were randomized to different modes of ventilation: (1) CON: normal ventilation for 30,min; (2) NVT: normal ventilation for 6,hr; (3) HFQ: ventilation for 6,hr at double frequency, but normal tidal volume (VT); and (4) HVT: 6,hr ventilation at double VT but normal frequency. Results NGF protein was detected in bronchoalveolar lavage fluid (BALF) and lung tissue in all animals. Ventilation for 6,hr significantly increased NGF levels, in both BALF and lung tissue, in the HFQ and HVT groups as compared to control (P,<,0.05). The maximum increase in BALF NGF was seen in the HVT group (P,=,0.02 vs. CON and NVT groups, and P,=,0.05 vs. HFQ). A parallel increase in interleukin 1-, (IL1-,) was observed. Expression of the high-affinity NGF-receptor, tropomyosin-related kinase A (TrkA), was also upregulated in these two groups. Conclusion Injurious modes of mechanical ventilation upregulate NGF and its receptor TrkA in rabbit lungs, and IL1-beta may be a mediator for this response. We speculate that this increase in NGF level may translate into the development of bronchial hyperreactivity. Pediatr Pulmonol. 2009; 44:713,719. © 2009 Wiley-Liss, Inc. [source]

Reference gene selection for real-time polymerase chain reaction in human lung cells subjected to cyclic mechanical strain

RESPIROLOGY, Issue 7 2008
Liao PINHU
Background and objective: The respiratory system is constantly exposed to mechanical forces that influence cellular phenotype in health and disease. Quantitative real-time PCR (qPCR) is widely used to determine gene expression. The validity of qPCR depends on using stable reference genes for normalization. The effect of cyclic mechanical strain on reference gene expression by lung epithelial, fibroblast and endothelial cells has not been studied systematically. Methods: The stability of expression of fourteen potential reference genes in response to six different regimens of cyclic mechanical strain was ranked using the geNorm tool in human lung epithelial cell lines (A549 and H441), human fetal lung fibroblasts (HFL-1), human lung microvascular endothelial cells, primary human lung fibroblasts and primary human alveolar type 2 (hAT2) cells. The expression variation of these reference genes was also screened in unstimulated whole human lung. Results: The stability of the selected reference genes varied within and between cell types, the variation in expression being greatest in primary cultures of hAT2. Correspondingly, the effect of expressing message for the stretch responsive gene IL-8 normalized to the 14 reference genes was greatest in the hAT2 cells, there being an almost fivefold difference in mRNA relative change comparing different reference genes in the same samples. The minimum number of genes required to derive a reliable normalization factor for experiments on single lung cell types undergoing mechanical strain was two and for whole human lung it was four. Conclusions: These results demonstrate that the optimal reference genes for lung cells subjected to CMS are cell type specific. [source]

Intracellular glutathione in stretch-induced cytokine release from alveolar type-2 like cells

Evidence for cocaine and methylecgonidine stimulation of M2 muscarinic receptors in cultured human embryonic lung cells

BRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2001
Yinke Yang
Muscarinic cholinoceptor stimulation leads to an increase in guanylyl cyclase activity and to a decrease in adenylyl cyclase activity. This study examined the effects of cocaine and methylecgonidine (MEG) on muscarinic receptors by measurement of cyclic GMP and cyclic AMP content in cultured human embryonic lung (HEL299) cells which specifically express M2 muscarinic receptors. A concentration-dependent increase in cyclic GMP production was observed in HEL299 cells incubated with carbachol, cocaine, or MEG for 24 h. The increase in cyclic GMP content was 3.6 fold for 1 ,M carbachol (P<0.01), 3.1 fold for 1 ,M cocaine (P<0.01), and 7.8 fold for 1 ,M MEG (P<0.001), respectively. This increase in cyclic GMP content was significantly attenuated or abolished by the muscarinic receptor antagonist atropine or the M2 blocker methoctramine. In contrast, cocaine, MEG, and carbachol produced a significant inhibition of cyclic AMP production in HEL299 cells. Compared to the control, HEL299 cells treated with 1 ,M cocaine decreased cyclic AMP production by 30%. MEG and carbachol at 1 ,M decreased cyclic AMP production by 37 and 38%, respectively. Atropine or methoctramine at 1 or 10 ,M significantly attenuated or abolished the cocaine-induced decrease in cyclic AMP production. However, the antagonists alone had neither an effect on cyclic GMP nor cyclic AMP production. Pretreatment of HEL299 cells with pertussis toxin prevented the cocaine-induced reduction of cyclic AMP production. Western blot analysis showed that HEL299 cells specifically express M2 muscarinic receptors without detectable M1 and M3. Incubation of HEL299 cells with cocaine, carbachol, and atropine did not alter the expression of M2 protein levels. However, the inducible isoform of nitric oxide synthase (iNOS) was induced in the presence of cocaine or carbachol and this induction was significantly attenuated after addition of atropine or methoctramine. The present data show that cocaine and MEG significantly affect cyclic GMP and cyclic AMP production in cultured HEL299 cells. Our results also show that these effects result from the drug-induced stimulation of M2 muscarinic receptors accompanied with no alterations of receptor expression. However, the induction of iNOS by cocaine may result in the increase in cyclic GMP production. British Journal of Pharmacology (2001) 132, 451,460; doi:10.1038/sj.bjp.0703819 [source]

Effect of montelukast pretreatment on inducible nitric oxide synthase mRNA expression in the lungs of antigen-challenged allergic mice

CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2003
K. Sade
Summary Background Growing evidence suggests that inducible nitric oxide synthase (iNOS) is the main source of the high output of exhaled nitric oxide (NO) in asthma. Treatment of asthmatic patients with glucocorticoids reduces high levels of exhaled NO mainly by inhibiting the transcription of iNOS. A similar reduction in exhaled NO was recently observed in patients treated with the leukotriene receptor antagonists, but the exact interaction between these drugs and iNOS remains obscure. Objective The purpose of this study was to evaluate the effect of a leukotriene receptor antagonist, montelukast, on the expression and activity of iNOS in a murine model of allergic asthma. Methods Twenty-four BALB/c mice were sensitized to OVA and were equally divided into 3 groups (Groups 1,3). Eight additional mice were sham sensitized and served as a negative control group (Group 4). Group 1 received montelukast 1 mg/kg/day in their drinking water, Group 2 received dexamethasone 1 mg/kg/day in their drinking water and Groups 3 and 4 received plain tap water. After 1 week, the animals were challenged by inhalation of OVA and, 3 h later, they were killed and their lung cells were isolated by enzymatic tissue digestion. NO generation was measured by a Griess assay, and iNOS mRNA was studied by RT-PCR. Results A significant increase in iNOS mRNA expression and in NO generation was evident after allergen challenge compared with the controls. Pretreatment with montelukast mildly decreased NO production without producing a concomitant significant decrease in iNOS mRNA expression. Conclusion: Unlike pretreatment with glucocorticoids, we failed to find compelling evidence for a major role for montelukast treatment in the modulation of iNOS mRNA in a murine model of acute asthma. [source]

CD4+ CD25+ transforming growth factor-,-producing T cells are present in the lung in murine tuberculosis and may regulate the host inflammatory response,

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
C. M. Mason
Summary CD4+ CD25+ regulatory T cells produce the anti-inflammatory cytokines transforming growth factor (TGF)-, or interleukin (IL)-10. Regulatory T cells have been recognized to suppress autoimmunity and promote self-tolerance. These cells may also facilitate pathogen persistence by down-regulating the host defence response during infection with Mycobacterium tuberculosis. We evaluated TGF-,+ and IL-10+ lung CD4+ CD25+ T cells in a murine model of M. tuberculosis. BALB/c mice were infected with ,50 colony-forming units of M. tuberculosis H37Rv intratracheally. At serial times post-infection, lung cells were analysed for surface marker expression (CD3, CD4, CD25) and intracellular IL-10, TGF-,, and interferon (IFN)-, production (following stimulation in vitro with anti-CD3 and anti-CD28 antibodies). CD4+ lung lymphocytes were also selected positively after lung digestion, and stimulated in vitro for 48 h with anti-CD3 and anti-CD28 antibodies in the absence and presence of anti-TGF-, antibody, anti-IL-10 antibody or rmTGF-, soluble receptor II/human Fc chimera (TGF,srII). Supernatants were assayed for elicited IFN-, and IL-2. Fluorescence activated cell sorter analyses showed that TGF-,- and IL-10-producing CD4+ CD25+ T cells are present in the lungs of infected mice. Neutralization of TGF-, and IL-10 each resulted in increases in elicited IFN-,, with the greatest effect seen when TGF,srII was used. Elicited IL-2 was not affected significantly by TGF-, neutralization. These results confirm the presence of CD4+ CD25+ TGF-,+ T cells in murine pulmonary tuberculosis, and support the possibility that TGF-, may contribute to down-regulation of the host response. [source]