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Baldys A, Pande P, Mosleh T, Park SH, Aust AE. Apoptosis induced by crocidolite asbestos in human lung epithelial cells involves inactivation of Akt and MAPK pathways. Apoptosis 2006; 12:433-47. [PMID: 17191120 DOI: 10.1007/s10495-006-0577-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Exposure of human lung epithelial (A549) cells to asbestos fibers causes apoptosis, which is largely attributed to release of iron and generation of reactive oxygen species (ROS) within the cells. To mimic the highly oxidative environment generated by asbestos exposure in the absence of the actual fibers, we used two chemicals; buthione sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis and ferric ammonium citrate (FAC), a source of iron. Here, we report that exposure of A549 cells to crocidolite asbestos led to a significant time-dependent inactivation of signaling proteins, i.e. Akt and all mitogen-activated protein kinases (MAPKs) (p38, ERK1/2 and SAPK/JNK), and subsequently to apoptosis. Unlike crocidolite treatment, the use of BSO and FAC, independently or combined, did not change the phosphorylation status of proteins, nor did it induce apoptosis. Taken together, our results presented herein point to the possibility that crocidolite-induced apoptosis of human lung epithelial cells is not a mere consequence of generation of oxidants but also requires inactivation of major cell growth and differentiation pathways.
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Affiliation(s)
- Aleksander Baldys
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
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2
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Manning CB, Mossman BT, Taatjes DJ. Analysis of asbestos-induced gene expression changes in bronchiolar epithelial cells using laser capture microdissection and quantitative reverse transcriptase-polymerase chain reaction. Methods Mol Biol 2006; 319:231-6. [PMID: 16719358 DOI: 10.1007/978-1-59259-993-6_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Laser capture microdissection (LCM) enables the removal of discrete microstructures or cell types from properly prepared histological sections. Extraction of RNA from microdissected tissue followed by quantitative reverse transcriptase-polymerase chain (QRT-PCR) reaction permits the analysis of cell-type or microstructure-specific gene expression changes that occur in response to various stimuli in the environment. In our lab, the combination of LCM and QRT-PCR has proven very useful in the determination of the in vivo gene expression changes that occur in bronchiolar epithelium in response to inhalation of crocidolite asbestos. A detailed description of the preparation of cDNA from bronchiolar epithelial cells obtained by LCM is described in this work.
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Cassiola F, Rogers RA, Kiyohara PK, Joekes I. Yeast cells long-term interaction with asbestos fibers. Colloids Surf B Biointerfaces 2005; 41:277-83. [PMID: 15748823 DOI: 10.1016/j.colsurfb.2004.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2004] [Revised: 12/04/2004] [Accepted: 12/17/2004] [Indexed: 11/22/2022]
Abstract
Saccharomyces cerevisiae was supported on chrysotile, crocidolite and lixiviated chrysotile. Samples of the supported cells and free cells were observed by confocal laser scanning microscopy. After 30 days, the free cells showed no viability when stored at 30 degrees C, and a viability of 40% when stored at 4 degrees C. Supported cells stored at 30 degrees C were more viable than the free cells at early times, but showed no viability after 30 days. Samples stored at 4 degrees C showed that the adhered cells are more viable than the free cells, up to 30 days. Cells supported on chrysotile and lixiviated chrysotile had 80% viability, and on crocidolite 70% viability. Scanning electron microscopy showed that cells supported on lixiviated chrysotile are fully covered by the support, but crocidolite fibers adhere less, since they are stiffer. Fermentation experiments performed after 3 years storage showed that four from the five lixiviated chrysotile samples and one of the three crocidolite samples were active. In all cases, a delay time for the onset of fermentation was observed indicating a state of latency.
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Affiliation(s)
- Flávia Cassiola
- Departamento de Físico Química, Instituto de Química, Universidade Estadual de Campinas, UNICAMP, Cx Postal 6154,13083-862 Campinas, SP, Brazil
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Iakhiaev A, Idell S. Asbestos induces tissue factor in Beas-2B cells via PI3 kinase-PKC-mediated signaling. J Toxicol Environ Health A 2004; 67:1537-1547. [PMID: 15371228 DOI: 10.1080/15287390490486716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Treatment of Beas-2B airway epithelial cells with crocidolite asbestos induced tissue factor (TF) mRNA and TF-dependent procoagulant activity. The mitogen-activated protein kinase (MAPK) inhibitors UO126 and SB203850 decreased TF expression in both naive and crocidolite-treated Beas-2B cells to the same extent. Calphostin, an inhibitor of classical and novel protein kinase C (PKC) isotypes, reduced TF mRNA in both intact and crocidolite-treated Beas-2B cells by about 50%. Conversely, the phosphatidylinositol 3-kinase (PI3 kinase) inhibitor LY294002 and a selective PKCzeta inhibitory peptide decreased TF mRNA expression in asbestos-treated cells to a greater extent than in naive cells, suggesting that signaling via this pathway contributes to asbestos-induced TF expression. These results demonstrate that crocidolite asbestos induces TF expression by Beas-2B cells and suggest that the process involves the PI3 kinase-PKCzeta signaling pathway, representing a newly recognized potential mechanism by which asbestos may contribute to lung remodeling.
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Affiliation(s)
- Alexei Iakhiaev
- Department of Specialty Care Services, University of Texas Health Center at Tyler, Tyler, Texas 75708, USA.
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Swain WA, O'Byrne KJ, Faux SP. Activation of p38 MAP kinase by asbestos in rat mesothelial cells is mediated by oxidative stress. Am J Physiol Lung Cell Mol Physiol 2004; 286:L859-65. [PMID: 14617514 DOI: 10.1152/ajplung.00162.2003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asbestos fibers are biopersistent particles that are capable of stimulating chronic inflammatory responses in the pleura of exposed individuals. Exposure of pleural mesothelial cells, the progenitor cell of malignant mesothelioma, to asbestos induces an array of cellular responses. The present studies investigated whether the p38 mitogen-activated protein kinase cascade was induced under asbestos-exposed conditions. p38 plays a vital role in the response to stressful stimuli and enables the cell to enter an inflammatory state characterized by cytokine production. Western blot and in vitro kinase assays showed increases in dual phosphorylation and actual activity of p38 after exposure to fibrous and nonfibrous (milled) crocidolite; in contrast, polystyrene beads and iron (III) oxide had no such effects. In common with other asbestos-induced events, this was shown to be an oxidative stress-sensitive effect, inasmuch as preincubation with N-acetyl-l-cysteine or α-tocopherol (vitamin E) ameliorated the effect. The present studies show that p38 activity is important for crocidolite-induced activator protein-1 DNA binding, inasmuch as an inhibitor of p38, SB-203580, reduced this activity. Crocidolite-induced cytotoxicity was also reduced with SB-203580, indicating a role for p38 in asbestos-mediated cell death. Our studies suggest that p38 activity could be a crucial factor in the chronic immune response elicited by asbestos and may represent a target for future pharmacological intervention.
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Affiliation(s)
- William A Swain
- Dept. of Oncology, Osborne Bldg., Univ. of Leicester, Leicester, UK.
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Xu A, Wu LJ, Tk H, Yu ZL. [CD59 mutation and DNA oxidative damage in A(L) cells induced by crocidolite fibers]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2004; 22:43-6. [PMID: 15033018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE To determine the effects of buthionine sulfoximine (BSO) and free radical scavenger, dimethyl sulfoxide (DMSO), on mutation frequency and the formation of 8-hydroxydeoxyganosine (8-OHdG) induced by crocidolite fibers in human-hamster hybrid (A(L)) cells. METHODS The cytotoxicity and mutagenicity were determined by the formation of colonies. 8-OHdG was examined by immunoperoxidase staining. Non-protein sulfhydryl (NPSH) compound was assayed by modified Tietze's method. RESULTS The level of NPSH in A(L) cell pretreated with 25 micro mol/L of BSO was decreased to 2 nmol/10(7) cells, only 5% of the control after 24 h. The mutation frequency of CD59 gene of A(L) cell in crocidolite alone treated group was 208 +/- 18 while that in BSO pretreated group (397 +/- 55) was about twice the former (P < 0.05). The mutation frequency of CD59 gene in the group treated with crocidolite and in the presence of DMSO (57 +/- 8) was 72.6% less than that in crocidolite alone treated group. Crocidolite fibers induced a dose-effect relationship in the formation of 8-OHdG in A(L) cells (y = 150 + 20x, r = 0.9621). The level of 8-OHdG in cells was 289 +/- 6 at the dose of 6 micro g/cm(2) crocidolite, which was about twice the control group (137 +/- 9). In the presence of DMSO, 8-OHdG level decreased to 170 +/- 3 at the same dose of crocidolite. CONCLUSION Free radicals are the important inducer of mutagenesis and DNA damage in A(L) cells caused by crocidolite, which has dose-effect relationship.
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Affiliation(s)
- An Xu
- Key Laboratory of Ion Beam Bioengineering of Institute of Plasma Physics, Chinese Academic of Sciences, Hefei 230031, China
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Iwagaki A, Choe N, Li Y, Hemenway DR, Kagan E. Asbestos inhalation induces tyrosine nitration associated with extracellular signal-regulated kinase 1/2 activation in the rat lung. Am J Respir Cell Mol Biol 2003; 28:51-60. [PMID: 12495932 DOI: 10.1165/rcmb.2002-0013oc] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Nitration of proteins by peroxynitrite (ONOO-) has been shown to critically alter protein function in vitro. We have shown previously that asbestos inhalation induced nitrotyrosine formation, a marker of ONOO- production, in the rat lung. To determine whether asbestos-induced protein nitration may affect mitogen-activated protein kinase (MAPK) signaling pathways, lung lysates from crocidolite and chrysotile asbestos-exposed rats and from sham-exposed rats were immunoprecipitated with anti-nitrotyrosine antibody, and captured proteins were subjected to Western blotting with anti-phospho-extracellular signal-regulated kinase (ERK)1/2 antibodies. Both types of asbestos inhalation induced significantly greater phosphorylation of ERK1/2 in rat lung lysates than was noted after sham exposure. Phosphorylated ERK proteins co-immunoprecipitated with nitrotyrosine. Moreover, in MAPK functional assays using Elk-1 substrate, immunoprecipitated phospho-ERK1/2 in lung lysates from both crocidolite-exposed and chrysotile-exposed rats demonstrated significantly greater phosphorylation of Elk-1 than was noted after sham exposure. Asbestos inhalation also induced ERK phosphorylation in bronchoalveolar lavage cells. Lung sections from rats exposed to crocidolite or chrysotile (but not from sham-exposed rats nor from rats exposed to "inert" carbonyl iron particles) demonstrated strong immunoreactivity for nitrotyrosine and phospho-ERK1/2 in alveolar macrophages and bronchiolar epithelium. These findings suggest that asbestos fibers may activate the ERK signaling pathway by generating ONOO- or other nitrating species that induce tyrosine nitration and phosphorylation of critical signaling molecules.
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Affiliation(s)
- Akitaka Iwagaki
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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Riganti C, Aldieri E, Bergandi L, Fenoglio I, Costamagna C, Fubini B, Bosia A, Ghigo D. Crocidolite asbestos inhibits pentose phosphate oxidative pathway and glucose 6-phosphate dehydrogenase activity in human lung epithelial cells. Free Radic Biol Med 2002; 32:938-49. [PMID: 11978496 DOI: 10.1016/s0891-5849(02)00800-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cytotoxicity of asbestos has been related to its ability to increase the production of reactive oxygen species (ROS), via the iron-catalyzed reduction of oxygen and/or the activation of NADPH oxidase. The pentose phosphate pathway (PPP) is generally activated by the cell exposure to oxidant molecules. Contrary to our expectations, asbestos (crocidolite) fibers caused a dose- and time-dependent inhibition of PPP and decreased its activation by an oxidative stress in human lung epithelial cells A549. In parallel, the intracellular activity of the PPP rate-limiting enzyme, glucose 6-phosphate dehydrogenase (G6PD), was significantly diminished by crocidolite exposure. This inhibition was selective, as the activity of other PPP and glycolysis enzymes was not modified, and was not attributable to a decreased expression of G6PD. On the opposite, the incubation with glass fibers MMVF10 did not modify PPP and G6PD activity. PPP and G6PD inhibition did not correlate with the increased nitric oxide (NO) production elicited by crocidolite in A549 cells. Experiments with the purified enzyme suggest that crocidolite inhibits G6PD by directly interacting with the protein. We propose here a new mechanism of asbestos-evoked oxidative stress, wherein fibers increase the intracellular ROS levels also by inhibiting the main antioxidant pathway of the cell.
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Affiliation(s)
- Chiara Riganti
- Interdepartmental Center "G. Scansetti" for Studies on Asbestos and other Toxic Particulates, University of Torino, Italy
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Aldieri E, Ghigo D, Tomatis M, Prandi L, Fenoglio I, Costamagna C, Pescarmona G, Bosia A, Fubini B. Iron inhibits the nitric oxide synthesis elicited by asbestos in murine macrophages. Free Radic Biol Med 2001; 31:412-7. [PMID: 11461780 DOI: 10.1016/s0891-5849(01)00612-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crocidolite fibers stimulated nitric oxide synthase (NOS) activity and expression in glial and alveolar murine macrophages: this effect was inhibited by iron supplementation and enhanced by iron chelation. We suggest that in these cells crocidolite stimulates NOS expression by decreasing the iron bioavailability and activating an iron-sensitive transcription factor.
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Affiliation(s)
- E Aldieri
- Department of Genetics, Biology, and Biochemistry, University of Torino, Via Santena, 5/bis-10126 Torino, Italy.
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Abstract
We showed previously that both crocidolite and chrysotile asbestos inhalation induced a persistent macrophage inflammatory response within the pleural space of the rat. We postulated that the stimulus for pleural macrophage recruitment after asbestos exposure was the induction of monocyte chemoattractant protein-1 (MCP-1) synthesis by pleural mesothelial cells. To test this hypothesis, rat pleural mesothelial cells (RPMC) were cultured with or without chrysotile or crocidolite asbestos fibers (8 micrograms/cm2) in the presence (50 ng/mL) or absence of either tumor necrosis factor-alpha (TNF-alpha) or interleukin-1 beta (IL-1 beta). MCP-1 mRNA expression was assessed by RT-PCR in RPMC cultured for 2 to 24 hours, and MCP-1 protein secretion was measured by ELISA in conditioned medium from 24-hour and 48-hour cultures. Crocidolite and chrysotile fibers induced MCP-1 mRNA expression in RPMC which was maximal after 12 hours in the absence of cytokines, but which peaked after 2 hours when RPMC were challenged with asbestos + TNF-alpha or IL-1 beta. Both types of asbestos also significantly increased MCP-1 protein secretion after 24 and 48 hours (P < .0001), an effect that was potentiated by cytokine stimulation. Rats exposed by inhalation to either chrysotile or crocidolite asbestos fibers also had greater amounts of MCP-1 protein in their pleural lavage fluid than did sham-exposed rats. These findings suggest that MCP-1 secretion by RPMC may have a role in the initiation and/or potentiation of asbestos-induced pleural injury.
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Affiliation(s)
- S Tanaka
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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Marchi E, Liu W, Broaddus VC. Mesothelial cell apoptosis is confirmed in vivo by morphological change in cytokeratin distribution. Am J Physiol Lung Cell Mol Physiol 2000; 278:L528-35. [PMID: 10710525 DOI: 10.1152/ajplung.2000.278.3.l528] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Apoptosis of mesothelial cells has been demonstrated in vitro but not in vivo. To identify apoptotic pleural cells as mesothelial, we used cytokeratin as a marker and found a striking spheroid, aggregated appearance of cytokeratin in apparently apoptotic mesothelial cells. In in vitro studies, we found that the aggregated cytokeratin pattern correlated with apoptosis in primary mesothelial cells from mice, rabbits, and humans and was not seen with necrosis. In in vivo studies in mice, we then used this cytokeratin pattern to identify and quantitate apoptotic mesothelial cells. Apoptotic mesothelial cells were best harvested by pleural lavage, indicating that they were loosely adherent or nonadherent. Instillation of RPMI 1640 medium or wollastonite for 24 h induced apoptosis in 0.1 +/- 0. 1 (SE) and 1.0 +/- 0.7%, respectively, of all mesothelial cells recovered, whereas instillation of known apoptotic stimuli, crocidolite asbestos (25 microg) for 24 h or actinomycin D plus murine tumor necrosis factor-alpha for 12 h, induced apoptosis in 5. 1 +/- 0.5 and 22.4 +/- 4.5%, respectively (significantly greater than in control experiments, P < 0.05). By analysis of cytokeratin staining, mesothelial cell apoptosis has been confirmed in vivo.
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Affiliation(s)
- E Marchi
- Lung Biology Center, San Francisco General Hospital, San Francisco, California 94143-0854, USA
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12
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Perkins RC, Broaddus VC, Shetty S, Hamilton S, Idell S. Asbestos upregulates expression of the urokinase-type plasminogen activator receptor on mesothelial cells. Am J Respir Cell Mol Biol 1999; 21:637-46. [PMID: 10536123 DOI: 10.1165/ajrcmb.21.5.3225] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Inhalation of asbestos is associated with pathologic changes in the pleural space, including pleural thickening, pleural plaques, and mesothelioma. These processes are characterized by altered local proteolysis, cellular proliferation, and cell migration, suggesting that the urokinase-type plasminogen activator receptor (uPAR) could be involved in the pathogenesis of asbestos-induced pleural disease. We hypothesized that mesothelial cell uPAR expression is induced by exposure to asbestos. To test this hypothesis, we used complementary techniques in rabbit and human mesothelial cells to determine whether uPAR expression is altered by exposure to asbestos. uPAR expression was induced by chrysotile and crocidolite asbestos, but not by wollastonite, as indicated by binding of radiolabeled urokinase-type plasminogen activator (uPA) to rabbit or human mesothelial cells. uPA was not induced by fiber exposure. Exposure to exogenous uPA increased uPA activity of cells exposed to wollastonite but not asbestos-treated MeT5A cells. uPAR expression increased further when asbestos was preincubated with vitronectin (VN) or serum. Increases in uPAR expression were confirmed by binding of uPA to uPAR in cell membrane preparations and immunofluorescent staining of uPAR at the cell surface, and were associated with increases in steady-state uPAR messenger RNA. Mesothelial cell uPAR expression was also induced by media from monocytes cultured with asbestos incubated with VN and serum. By antibody neutralization, the latter effect appeared to be in part mediated by transforming growth factor-beta. We found that asbestos increases uPAR at the surface of rabbit and human mesothelial cells, suggesting that altered expression of this receptor could be involved in asbestos-induced remodeling of the pleural mesothelium.
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Affiliation(s)
- R C Perkins
- Department of Specialty Care, The University of Texas Health Center at Tyler, Tyler, Texas 75710, USA.
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Zanella CL, Timblin CR, Cummins A, Jung M, Goldberg J, Raabe R, Tritton TR, Mossman BT. Asbestos-induced phosphorylation of epidermal growth factor receptor is linked to c-fos and apoptosis. Am J Physiol 1999; 277:L684-93. [PMID: 10516208 DOI: 10.1152/ajplung.1999.277.4.l684] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the mechanisms of interaction of crocidolite asbestos fibers with the epidermal growth factor (EGF) receptor (EGFR) and the role of the EGFR-extracellular signal-regulated kinase (ERK) signaling pathway in early-response protooncogene (c-fos/c-jun) expression and apoptosis induced by asbestos in rat pleural mesothelial (RPM) cells. Asbestos fibers, but not the nonfibrous analog riebeckite, abolished binding of EGF to the EGFR. This was not due to a direct interaction of fibers with ligand, inasmuch as binding studies using fibers and EGF in the absence of membranes showed that EGF did not adsorb to the surface of asbestos fibers. Exposure of RPM cells to asbestos caused a greater than twofold increase in steady-state message and protein levels of EGFR (P < 0.05). The tyrphostin AG-1478, which inhibits the tyrosine kinase activity of the EGFR, but not the tyrphostin A-10, which does not affect EGFR activity, significantly ameliorated asbestos-induced increases in mRNA levels of c-fos but not of c-jun. Pretreatment of RPM cells with AG-1478 significantly reduced apoptosis in cells exposed to asbestos. Our findings suggest that asbestos-induced binding to EGFR initiates signaling pathways responsible for increased expression of the protooncogene c-fos and the development of apoptosis. The ability to block asbestos-induced elevations in c-fos mRNA levels and apoptosis by small-molecule inhibitors of EGFR phosphorylation may have therapeutic implications in asbestos-related diseases.
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Affiliation(s)
- C L Zanella
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
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14
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Choe N, Zhang J, Iwagaki A, Tanaka S, Hemenway DR, Kagan E. Asbestos exposure upregulates the adhesion of pleural leukocytes to pleural mesothelial cells via VCAM-1. Am J Physiol 1999; 277:L292-300. [PMID: 10444523 DOI: 10.1152/ajplung.1999.277.2.l292] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was designed to assess the effects of in vitro and in vivo asbestos exposure on the adhesion of rat pleural leukocytes (RPLs) labeled with the fluorochrome calcein AM to rat pleural mesothelial cells (RPMCs). Exposure of RPMCs for 24 h to either crocidolite or chrysotile fibers (1.25-10 microgram/cm(2)) increased the adhesion of RPLs to RPMCs in a dose-dependent fashion, an effect that was potentiated by interleukin-1beta. These findings were not observed with nonfibrogenic carbonyl iron particles. Crocidolite and chrysotile plus interleukin-1beta also upregulated vascular cell adhesion molecule-1 mRNA and protein expression in RPMCs, and the binding of RPL to asbestos-treated RPMCs was abrogated by anti-vascular cell adhesion molecule-1 antibody. PRLs exposed by intermittent inhalation to crocidolite for 2 wk manifested significantly greater binding to RPMCs than did RPLs from sham-exposed animals. The ability of asbestos fibers to upregulate RPL adhesion to RPMCs may play a role in the induction and/or potentiation of asbestos-induced pleural injury.
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Affiliation(s)
- N Choe
- Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA
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15
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Ding M, Dong Z, Chen F, Pack D, Ma WY, Ye J, Shi X, Castranova V, Vallyathan V. Asbestos induces activator protein-1 transactivation in transgenic mice. Cancer Res 1999; 59:1884-9. [PMID: 10213496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Activation of activator protein (AP-1) by crocidolite asbestos was examined in vitro in a JB6 P+ cell line stably transfected with AP-1-luciferase reporter plasmid and in vivo using AP-1-luciferase reporter transgenic mice. In in vitro studies, crocidolite asbestos caused a dose- and time-dependent induction of AP-1 activation in cultured JB6 cells. The elevated AP-1 activity persisted for at least 48 h. Crocidolite asbestos also induced AP-1 transactivation in the pulmonary and bronchial tissues of transgenic mice. AP-1 activation was observed at 2 days after intratracheal instillation of the mice with asbestos. At 3 days postexposure, AP-1 activation was elevated 10-fold in the lung tissue and 22-fold in bronchiolar tissue as compared with their controls. The induction of AP-1 activity by asbestos appeared to be mediated through the activation of mitogen-activated protein kinase family members, including extracellular signal-regulating protein kinase, Erk1 and Erk2. Aspirin inhibited asbestos-induced AP-1 activity in JB6 cells. Pretreatment of the mice with aspirin also inhibited asbestos-induced AP-1 activation in bronchiolar tissue. The data suggest that further investigation of the role of AP-1 activation in asbestos-induced cell proliferation and carcinogenesis is warranted. In addition, investigation of the potential therapeutic benefits of aspirin in the prevention/amelioration of asbestos-induced cancer is justified.
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Affiliation(s)
- M Ding
- Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA
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16
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Abstract
Treatment of human lung epithelial (A549) cells with crocidolite asbestos resulted in the induction of the inducible form of nitric oxide synthase (iNOS), production of NO, and a dramatic decrease in intracellular reduced glutathione (GSH). Iron, mobilized from the crocidolite fibers (27% iron by weight), and the formation of NO were required for the formation of 2'-deoxy-7-hydro-8-oxoguanosine in the DNA of the A549 cells, but not for the decrease in GSH. Therefore, we investigated the role of GSH and iron in the induction of iNOS in A549 cells by crocidolite. Iron was required for the induction of iNOS by crocidolite. A fivefold higher amount of chrysotile asbestos (3% iron by weight) was required to cause a similar decrease in intracellular GSH and induction of iNOS. In the absence of asbestos, treatment with either buthionine sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or ferric ammonium citrate (FAC), a soluble form of iron, did not result in induction of iNOS. However, iNOS was induced when A549 cells were treated simultaneously with BSO and FAC. The presence of 5 mM N-acetylcysteine prevented induction of iNOS in crocidolite-treated A549 cells. These observations suggest that the induction of iNOS resulted from a decrease in intracellular GSH and the presence of iron from the asbestos fibers.
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Affiliation(s)
- S H Park
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322-0300, USA
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17
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Fung H, Kow YW, Van Houten B, Taatjes DJ, Hatahet Z, Janssen YM, Vacek P, Faux SP, Mossman BT. Asbestos increases mammalian AP-endonuclease gene expression, protein levels, and enzyme activity in mesothelial cells. Cancer Res 1998; 58:189-94. [PMID: 9443389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Only two DNA repair enzymes, DNA polymerase beta and O6-methylguanine-DNA methyltransferase, have been shown to be inducible in mammalian cells by genotoxic agents. We show here that crocidolite asbestos induces the DNA repair enzyme, apurinic/apyrimidinic (AP)-endonuclease, in isolated mesothelial cells, the progenitor cells of malignant mesothelioma. Asbestos at nontoxic concentrations of 1.25 and 2.5 microg/cm2 significantly increased AP-endonuclease mRNA and protein levels as well as enzyme activity (P < 0.05) in a dose-dependent manner in rat pleural mesothelial cells. These increases were persistent from 24 to 72 h after initial exposure to fibers. Changes were not observed with glass beads, a noncarcinogenic particle. Confocal scanning laser microscopy showed that AP-endonuclease was primarily localized in the nucleus but also in mitochondria. Our data are the first to demonstrate the inducibility of AP-endonuclease by a human class I carcinogen associated with oxidant stress in normal cells of the lung.
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Affiliation(s)
- H Fung
- Department of Pathology, University of Vermont, Burlington 05405, USA
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18
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Levresse V, Renier A, Fleury-Feith J, Levy F, Moritz S, Vivo C, Pilatte Y, Jaurand MC. Analysis of cell cycle disruptions in cultures of rat pleural mesothelial cells exposed to asbestos fibers. Am J Respir Cell Mol Biol 1997; 17:660-71. [PMID: 9409553 DOI: 10.1165/ajrcmb.17.6.2854] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The control of DNA integrity in mammalian cells is important to maintain the cell homeostasis and prevent neoplastic transformation. Control of cell division and cell death permits repair or elimination of damaged cells. Since asbestos fibers can produce DNA damage, chromosome alterations and apoptosis in several sorts of cells, including mesothelial cells, it was interesting to investigate cell cycle disturbances in rat pleural mesothelial cells (RPMC) treated with asbestos fibers. Cell cycle analyses were performed in RPMC exposed to crocidolite (10 and 20 microg/cm2) and chrysotile (5 and 10 microg/cm2) for different times (4 to 48 h). Both fiber types entailed a G2/M accumulation in agreement with a delay in the mitosis course. Chrysotile fibers produced a G0/G1 accumulation associated with a time-dependent p53 and p21 expression. Crocidolite exposure resulted in a delay in the G1/S transition paralleling a low rate of p53 expression. These results are in agreement with a DNA damaging potential of asbestos fibers since similar results were found following RPMC exposure to gamma rays. In asbestos-treated RPMC, a low rate of apoptosis was found suggesting that RPMC may follow a DNA repair pathway that could contribute to the formation of DNA lesions. In addition, the cell cycle disturbances at the G2/M checkpoint suggest that genetically altered cells have progressed through the cycle and support the already published findings on the ability of asbestos fibers to impair cell division.
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Affiliation(s)
- V Levresse
- INSERM U 139, Institut mondor de Médècine Moliculaire, Faculté de Médecine, Créteil, France
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19
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Jiménez LA, Zanella C, Fung H, Janssen YM, Vacek P, Charland C, Goldberg J, Mossman BT. Role of extracellular signal-regulated protein kinases in apoptosis by asbestos and H2O2. Am J Physiol 1997; 273:L1029-35. [PMID: 9374731 DOI: 10.1152/ajplung.1997.273.5.l1029] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Stimulation of cell signaling cascades by oxidants may be important in the pathogenesis of pulmonary and pleural diseases. Here, we demonstrate in rat pleural mesothelial cells that apoptotic concentrations of crocidolite asbestos and H2O2 induce phosphorylation and activation of extracellular signal-regulated protein kinases (ERK). Activation of c-jun-NH2-terminal protein kinases (JNK)/stress-activated protein kinases was also observed in response to H2O2. In contrast, asbestos caused more protracted activation of ERK without JNK activation. Both H2O2- and asbestos-induced activation of ERK was abolished by catalase. Moreover, chelation of surface iron from crocidolite fibers or addition of N-acetyl-L-cysteine prevented ERK activation and apoptosis by crocidolite, indicating an oxidative mechanism of cell signaling. The MEK1 inhibitor PD-98059 abrogated asbestos-induced apoptosis, confirming a causal relationship between ERK activation and apoptosis. These results suggest that distinct cell-signaling cascades may be important in phenotypic responses elicited by oxidant stresses.
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Affiliation(s)
- L A Jiménez
- Department of Pathology, College of Medicine, University of Vermont, Burlington 05405, USA
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20
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Simeonova PP, Toriumi W, Kommineni C, Erkan M, Munson AE, Rom WN, Luster MI. Molecular regulation of IL-6 activation by asbestos in lung epithelial cells: role of reactive oxygen species. J Immunol 1997; 159:3921-8. [PMID: 9378980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
IL-6 has been characterized as a pleiotropic cytokine with multiple biologic activities, but its induction and role in asbestos diseases have not been studied. Asbestos fibers were found to stimulate IL-6 expression and secretion in pulmonary type II-like epithelial A549 cells as well as in normal human bronchial epithelial cells. IL-6 induction was dependent on the intracellular redox-oxidative state, since intracellular hydroxyl scavengers and N-acetylcysteine, a precursor of glutathione, abrogated IL-6 secretion by asbestos or H2O2. IL-6 induction paralleled increased DNA binding activity to the nuclear factor-kappa B (NF-kappa B)- and NF-IL-6-recognized sites in the IL-6 promoter. The NF-kappa B and NF-IL-6 DNA binding proteins were immunochemically characterized as a heterodimer p65/p50 and a homodimer C/EBP beta, respectively. Stimulation of DNA binding activity to the NF-kappa B and NF-IL-6 binding sites of the IL-6 promoter by asbestos or H2O2 were inhibited by tetramethylthiourea, a hydroxyl radical scavenger. The role of local IL-6 production in the pathophysiologic processes of fiber-induced lung disorders was examined. Although less active than fibroblast growth factor, human rIL-6 also stimulated lung fibroblast growth, as evidenced by increased [3H]thymidine incorporation. Furthermore, elevated IL-6 levels were found in bronchoalveolar lavage fluids from patients diagnosed with lung fibrosis and work-related histories of long term asbestos exposure. Taken together, the results suggest that asbestos-induced oxidative stress is involved in the activation of NF-kappa B and NF-IL-6 transcription factors, which recognize the IL-6 promoter. The resulting increase in IL-6 expression may be involved in both inflammatory and fibrotic processes in the lung.
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Affiliation(s)
- P P Simeonova
- Toxicology and Molecular Biology Branch, National Institute of Occupational Safety and Health, Morgantown, WV 26505, USA
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21
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Goldberg JL, Zanella CL, Janssen YM, Timblin CR, Jimenez LA, Vacek P, Taatjes DJ, Mossman BT. Novel cell imaging techniques show induction of apoptosis and proliferation in mesothelial cells by asbestos. Am J Respir Cell Mol Biol 1997; 17:265-71. [PMID: 9308911 DOI: 10.1165/ajrcmb.17.3.2991] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We developed in situ dual-fluorescence detection techniques for measuring apoptosis and proliferation simultaneously in single dishes of cells. The deoxyribonucleic acid (DNA)-specific labeling method, terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), first was used in conjunction with a 4',6-diamidino-2-phenylindole (DAPI) counterstain to detect and measure morphologic characteristics of apoptotic rat pleural mesothelial (RPM) cells isolated from Fischer 344 rats and exposed to 300 microM hydrogen peroxide (H2O2). For this purpose, 100 TUNEL-positive nuclei were measured while being viewed with DAPI counterstaining for area, perimeter, longest diameter, and average diameter, using imaging software and an image-collection apparatus. We then exposed cells to a range of concentrations of crocidolite asbestos and putative apoptotic and mitogenic agents. Exposure to crocidolite asbestos (5 microg/cm2) caused a striking dose-dependent apoptotic response at 24 h, 48 h, and 72 h. The nonfibrous crocidolite analogue riebeckite failed to induce apoptosis. At 24 h, tumor necrosis factor-alpha (TNF-alpha) (10 ng/ml) caused an increase in apoptotic nuclei. A second method, utilizing an antibody to 5'-bromodeoxyridine (BrdU) and oxazole yellow homodimer (YOYO), showed a dose-dependent increase in proliferation occurring in cells exposed to asbestos (5 microg/cm2) at 48 h and 72 h. In addition, increased numbers of rat pleural mesothelial (RPM) cells exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA), TNF-alpha, and epidermal growth factor (EGF) exhibited incorporation of BrdU at these time points, although total numbers of cells per unit area were unchanged. Results indicate a dynamic balance between apoptosis and increased DNA synthesis after exposure of mesothelial cells to asbestos.
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Affiliation(s)
- J L Goldberg
- Department of Pathology, University of Vermont, Burlington 05405, USA
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22
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Amati M, Visonà I, Valentino M, Scancarello G, Governa M. [Reactive oxygen species produced by the addition of sepiolite and vermiculite (expanded or not) to suspensions of human polymorphonuclear phagocytes and bovine alveolar macrophages]. G Ital Med Lav Ergon 1997; 19:59-61. [PMID: 9377750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have studied a sample of commercial sepiolite and two samples of commercial vermiculite, which are clay minerals advised to replace asbestos. We have in vitro tested their abilities to produce reacting oxygen species (ROS) after they have been added to suspension of human polymorphonuclear leukocytes and bovine alveolar macrophages. The behaviour of sepiolite and vermiculite have been compared with those of asbestos fibres given by Unione Internationale contre le Cancer (UICC) and with kaolin and illite. Sepiolite was not able to induce ROS production, while vermiculite was able to induce a relevant ROS generation, even if the values were always lower than that obtained from chrysotile. Kaolin was able to generate a high ROS production.
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Affiliation(s)
- M Amati
- Clinica di Medicina del Lavoro, Università di Ancona, Ospedale Regionale di Torrette AN
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23
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Zanella CL, Posada J, Tritton TR, Mossman BT. Asbestos causes stimulation of the extracellular signal-regulated kinase 1 mitogen-activated protein kinase cascade after phosphorylation of the epidermal growth factor receptor. Cancer Res 1996; 56:5334-8. [PMID: 8968079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Asbestos fibers are human carcinogens with undefined mechanisms of action. In studies here, we examined signal transduction events induced by asbestos in target cells of mesothelioma and potential cell surface origins for these cascades. Asbestos fibers, but not their nonfibrous analogues, induced protracted phosphorylation of the mitogen-activated protein (MAP) kinases and extracellular signal-regulated kinases (ERK) 1 and 2, and increased kinase activity of ERK2. ERK1 and ERK2 phosphorylation and activity were initiated by addition of exogenous epidermal growth factor (EGF) and transforming growth factor-alpha, but not by isoforms of platelet-derived growth factor or insulin-like growth factor-1 in mesothelial cells. MAP kinase activation by asbestos was attenuated by suramin, which inhibits growth factor receptor interactions, or tyrphostin AG 1478, a specific inhibitor of EGF receptor tyrosine kinase activity (IC50 = 3 nM). Moreover, asbestos caused autophosphorylation of the EGF receptor, an event triggering the ERK cascade. These studies are the first to establish that a MAP kinase signal transduction pathway is initiated after phosphorylation of a peptide growth factor receptor following exposure to asbestos fibers.
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Affiliation(s)
- C L Zanella
- Department of Pathology, Vermont Cancer Center, University of Vermont College of Medicine, Burlington 05405, USA
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24
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Aufderheide M, Knebel JW, Schulte P. Differences in the sensitivity of hamster and rat lung cells exposed in vitro to natural and man-made fibres. Exp Toxicol Pathol 1996; 48:505-7. [PMID: 8954333 DOI: 10.1016/s0940-2993(96)80067-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- M Aufderheide
- Institute of Experimental Pathology, Hannover Medical School, Germany
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25
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Gelzleichter TR, Mangum JB, Bermudez E, Wong BA, Moss OR, Everitt JI. Pulmonary and pleural leukocytes from F344 rats produce elevated levels of fibronectin following inhalation of refractory ceramic fibers. Exp Toxicol Pathol 1996; 48:487-9. [PMID: 8954328 DOI: 10.1016/s0940-2993(96)80062-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T R Gelzleichter
- Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina, USA
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26
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BéruBé KA, Quinlan TR, Fung H, Magae J, Vacek P, Taatjes DJ, Mossman BT. Apoptosis is observed in mesothelial cells after exposure to crocidolite asbestos. Am J Respir Cell Mol Biol 1996; 15:141-7. [PMID: 8679218 DOI: 10.1165/ajrcmb.15.1.8679218] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Asbestos causes protracted, dose-dependent increases in steady-state mRNA levels of the proto-oncogenes c-fos and c-jun, and AP-1 DNA-binding activity in normal rat pleural mesothelial (RPM) cells (1). To determine the phenotypic end points of overexpression of these early response genes by asbestos, both cell proliferation and apoptosis were examined in confluent RPM cells exposed to a range of concentrations (1.25 to 10 micrograms/cm2 dish) of crocidolite asbestos for 24 and 48 h. Quantitation of RPM cells pulsed with 5-bromo-2'-deoxyuridine revealed that asbestos caused dose-dependent decreases in cells undergoing DNA synthesis. Decreases in cell proliferation were accompanied by dose-related increases in apoptosis using (1) terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (i.e., ApopTag technique), (2) 4',6-diamidino-2-phenylindole cell staining, and (3) fluorescent-activated cell sorter after incorporation of propidium iodide. Less striking but significant dose-related increases in apoptosis were observed in RPM cells exposed to H2O2 (300 microM), and no apoptosis was seen after exposure of cells to high concentrations (10 micrograms/cm2 dish) of glass beads. Our results are unique in that they demonstrate that asbestos induces apoptosis in mesothelial cells at concentrations eliciting increased expression of the proto-oncogenes c-fos and c-jun.
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Affiliation(s)
- K A BéruBé
- Department of Pathology, University of Vermont, Burlington 05405, USA
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27
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Broser M, Zhang Y, Aston C, Harkin T, Rom WN. Elevated interleukin-8 in the alveolitis of individuals with asbestos exposure. Int Arch Occup Environ Health 1996; 68:109-14. [PMID: 8720280 DOI: 10.1007/bf00381242] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Asbestosis is a fibrotic and inflammatory interstitial lung disease occurring after chronic occupational exposure to asbestos. An alveolitis has been described with activated alveolar macrophages and increased neutrophils as sampled by bronchoalveolar lavage (BAL). Animal models and in vitro studies demonstrate that asbestos can stimulate alveolar macrophages to release neutrophil chemotactic factor. We performed BAL on 18 nonsmoking individuals with asbestos exposure and observed a twofold increase in percent neutrophils recovered. Alveolar macrophages cultured in vitro from the asbestos-exposed individuals spontaneously released significant amounts of the neutrophil chemotaxin, interleukin-8 (IL-8). In addition, the alveolar macrophages expressed a 2.7-fold increase in steady state mRNA levels compared to unexposed normal controls utilizing the reverse transcriptase/polymerase chain reaction. In vitro experiments confirmed that crocidolite or chrysotile asbestos could stimulate the release of IL-8 from mononuclear phagocytes in a dose-dependent fashion. We conclude that asbestos exposure causes a mild neutrophilic alveolitis, and that IL-8 is one potential mediator capable of contributing to this inflammation in the lower respiratory tract.
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Affiliation(s)
- M Broser
- Department of Medicine, New York University Medical Center, New York 10016, USA
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28
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Janssen YM, Heintz NH, Mossman BT. Induction of c-fos and c-jun proto-oncogene expression by asbestos is ameliorated by N-acetyl-L-cysteine in mesothelial cells. Cancer Res 1995; 55:2085-9. [PMID: 7743507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Asbestos fibers cause dose-dependent, persistent increases in mRNA levels of c-jun and c-fos proto-oncogenes in rat pleural mesothelial (RPM) cells, the progenitor cells of asbestos-induced mesothelioma (N. Heintz, Y. M. W. Janssen, and B. T. Mossman. Proc. Natl. Acad. Sci. USA, 90: 3299-3303, 1993). Here we report that addition of N-acetyl-L-cysteine decreases asbestos-mediated induction of c-fos and c-jun mRNA levels in a dose-dependent fashion. Exposure of RPM cells to asbestos causes depletion of total cellular glutathione, a response that can be abolished by pretreatment with N-acetyl-L-cysteine. Pretreatment of cells with buthionine sulfoximine, an agent which diminishes glutathione pools, increases the magnitude of induction of c-fos and c-jun mRNA by asbestos. To determine whether asbestos-induced effects on proto-oncogene expression could be attributed to extracellular generation of active oxygen species (AOS), RPM cells were exposed to H2O2 or xanthine and xanthine oxidase, a generating system of AOS. These oxidant stresses did not decrease cellular glutathione levels nor alter mRNA levels of c-fos or c-jun. However, increased mRNA levels of manganese-containing superoxide dismutase and heme oxygenase were observed, indicating that RPM cells respond to AOS by increased expression of genes encoding antioxidant enzymes. These data indicate that the signaling pathways leading to c-fos/c-jun proto-oncogene induction by asbestos are not triggered directly by formation of extracellular AOS. However, intracellular thiol levels appear to influence the expression of c-fos and c-jun, suggesting a redox-sensitive component in the signaling cascade which modulates gene expression of c-fos and c-jun by asbestos.
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Affiliation(s)
- Y M Janssen
- Department of Pathology, University of Vermont College of Medicine, Burlington 05405, USA
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29
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Leikauf GD, Fink SP, Miller ML, Lockey JE, Driscoll KE. Refractory ceramic fibers activate alveolar macrophage eicosanoid and cytokine release. J Appl Physiol (1985) 1995; 78:164-71. [PMID: 7713806 DOI: 10.1152/jappl.1995.78.1.164] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Refractory ceramic fiber has been developed for industrial processes requiring materials with high thermal and mechanical stability. To evaluate the biological activity of this fiber, rat alveolar macrophages were exposed for < or = 24 h to 0-1,000 micrograms/ml of refractory ceramic fiber, crocidolite asbestos, silica (fibrogenic particles), or titanium dioxide (a nonfibrogenic particle), and eicosanoid, tumor necrosis factor-alpha (TNF), and lactate dehydrogenase release were measured. Particle dimensions were determined by electron microscopy. Radioactivity coeluting with leukotriene B4 (LTB4) and immunoreactive LTB4 and TNF release increased after refractory ceramic fiber and were similar in magnitude after asbestos but less than after silica. For example, the total [3H]eicosanoid release increased 3.9-fold after refractory ceramic fiber, 4.6-fold after asbestos, and 8.7-fold after silica. Refractory ceramic fiber and asbestos also have similar particle dimensions (diameter, length, and surface area). Inasmuch as macrophage-derived LTB4 and TNF are potent mediators in inflammatory events, including migration and activation of neutrophils, these findings suggest that refractory ceramic fiber can activate macrophages in vitro to release mediators relevant to in vivo findings of inflammation and fibrotic lung disease in laboratory animals.
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Affiliation(s)
- G D Leikauf
- Department of Environmental Health, College of Medicine, University of Cincinnati 45267
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30
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Thomas G, Ando T, Verma K, Kagan E. Asbestos fibers and interferon-gamma up-regulate nitric oxide production in rat alveolar macrophages. Am J Respir Cell Mol Biol 1994; 11:707-15. [PMID: 7524571 DOI: 10.1165/ajrcmb.11.6.7524571] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The present study was undertaken to determine whether asbestos exposure induces the formation of nitric oxide (NO.) radical by rat alveolar macrophages (AM). For this purpose, AM from Sprague-Dawley rats were cultured for 48 h in the presence or absence of either chrysotile (serpentine) or crocidolite (amphibole) asbestos fibers. The effects of asbestos fibers were compared with those of nonfibrogenic carbonyl iron particles. Nitrite (NO2-), the stable oxidation product of NO. in macrophage conditioned medium, was assayed by the Griess reaction. Production of NO2- by AM was significantly increased by both chrysotile (P < 0.01) and crocidolite (P < 0.05) asbestos fibers (10 micrograms/ml). Since interferon-gamma (IFN-gamma) is known to induce NO. synthase within macrophages, and since elevated levels of intrapulmonary IFN-gamma have been noted in asbestos workers, the combined effects of asbestos and IFN-gamma also were studied in the context of NO. formation. Addition of IFN-gamma (250 to 500 IU/ml) synergistically enhanced the formation of NO2- induced by chrysotile and crocidolite. Notably, carbonyl iron had no significant effect on NO. production by AM. NO2- production was significantly attenuated by the NO. synthase inhibitor, NG-monomethyl-L-arginine (0.5 to 1 mg/ml). By contrast, superoxide dismutase (150 U/ml) significantly enhanced asbestos-induced NO2- production by AM (P < 0.001). Since superoxide anion can interact with NO. to generate the toxic hydroxyl radical, and since superoxide dismutase is known to protect against asbestos-induced injury, the induction of NO. radical by asbestos fibers may represent a novel form of asbestos-related injury.
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MESH Headings
- Amino Acid Oxidoreductases/antagonists & inhibitors
- Amino Acid Oxidoreductases/metabolism
- Animals
- Aorta/physiology
- Arginine/analogs & derivatives
- Arginine/pharmacology
- Asbestos, Crocidolite/pharmacology
- Asbestos, Crocidolite/toxicity
- Asbestos, Serpentine/pharmacology
- Asbestos, Serpentine/toxicity
- Biological Assay
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Interferon-gamma/pharmacology
- Iron Carbonyl Compounds
- L-Lactate Dehydrogenase/metabolism
- Macrophages, Alveolar/metabolism
- Male
- Muscle, Smooth, Vascular/physiology
- Nitric Oxide/biosynthesis
- Nitric Oxide Synthase
- Organometallic Compounds/pharmacology
- Organometallic Compounds/toxicity
- Rats
- Rats, Sprague-Dawley
- Superoxide Dismutase/pharmacology
- Up-Regulation/drug effects
- omega-N-Methylarginine
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Affiliation(s)
- G Thomas
- Department of Pathology, Georgetown University School of Medicine, Washington, DC
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31
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Abstract
Neutron-activated crocidolite, containing 55Fe and 59Fe, was used to determine whether iron was mobilized from crocidolite phagocytized by cultured human lung carcinoma cells (A549 cells). Cells were treated with neutron-activated crocidolite in medium at pH 6.8 or 7.4 for 24 h. The mobilization of iron into two subcellular fractions, 10,000g supernatant (total iron) or < 10,000 MW [low-molecular-weight (LMW)] was monitored using scintillation counting. Iron was mobilized from crocidolite at a rate similar to that observed in vitro when citrate was incubated with crocidolite for 24 h at pH 7.4, but the amount mobilized was greater when cells were cultured at pH 6.8 than at 7.4. Iron mobilization was not due to the medium nor did it appear to be due to differences in the amount of crocidolite phagocytized. At the highest concentration of crocidolite used for treatment at pH 7.4 (4.5 micrograms/cm2), a total of 3600 pmol iron/10(6) cells was mobilized of which 54 pmol/10(6) cells was in a LMW fraction. After estimation of the volume of the cells, this was calculated to be equivalent to an intracellular concentration of 1.4 mM iron of which 22 microM was in the LMW fraction. Cell survival decreased linearly as the iron mobilized into the LMW fraction increased, independent of the pH of the culture medium being used. These results suggest that iron mobilization from crocidolite into a LMW fraction may represent "iron overload" in cells which have phagocytized the fibers and may be responsible for crocidolite-dependent cytotoxicity and possibly other crocidolite-dependent biological effects.
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Affiliation(s)
- C C Chao
- Department of Chemistry and Biochemistry, Utah State University, Logan 84322-0300
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32
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Abstract
This study has shown, for the first time, that in vitro exposure of rat AMs to either crocidolite (amphibole) or chrysotile (serpentine) asbestos fibers induces the synthesis not only of the O2*- anion, but also of the nitrogen radical, NO*. Furthermore, this asbestos-related effect is enhanced in the presence of interferon-gamma. NO* has been implicated in several pathologic reactions, such as inflammation and immune complex-mediated cell injury. Additionally, NO* may interact with secondary amines to generate nitrosamines, which are potent carcinogens. Our findings could represent a novel type of asbestos-mediated injury, and we propose that the injurious effects of asbestos might be mediated via the interaction of NO* with O2*-, with the generation of ONOO- and other potent toxic free radicals.
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Affiliation(s)
- G Thomas
- Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, District of Columbia 20007
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33
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Ghio AJ, Kennedy TP, Stonehuerner JG, Crumbliss AL, Hoidal JR. DNA strand breaks following in vitro exposure to asbestos increase with surface-complexed [Fe3+]. Arch Biochem Biophys 1994; 311:13-8. [PMID: 8185309 DOI: 10.1006/abbi.1994.1202] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Surface functional groups on silicate dusts complex iron cations which can cycle through reduction and oxidation states to generate free radicals. These oxidants have a capacity to produce DNA strand breaks and mutations which are primary events in cancer induction. A differential in the capacity of fibrous silicates to produce carcinoma is recognized with the amphiboles demonstrating a greater biologic effect than the serpentine fiber chrysotile. We tested the hypothesis that the differences in genotoxicity of these fibrous silicates correspond to varying concentrations of iron complexed to the surface. Relative to chrysotile, the amphibole fibers complexed greater amounts of iron cations from both inorganic and in vivo sources. Increased concentrations of surface-complexed iron were associated with greater oxidant generation, measured as thiobarbituric acid-reactive products of deoxyribose, and more covalently closed, circular DNA strand scission. These results indicate that genotoxic effects of these fibers may correspond to their capacity to complex iron at the surface.
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Affiliation(s)
- A J Ghio
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
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Li XY, Lamb D, Donaldson K. The production of TNF-alpha and IL-1-like activity by bronchoalveolar leucocytes after intratracheal instillation of crocidolite asbestos. Int J Exp Pathol 1993; 74:403-10. [PMID: 8398814 PMCID: PMC2001853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We have used a rat intratracheal instillation model to study the effect of crocidolite asbestos exposure on cytokine production by bronchoalveolar lavage (BAL) leucocytes. In unexposed controls, the normal BAL leucocytes were mostly macrophages which spontaneously produced interleukin 1 (IL-1)-like activity and tumour necrosis factor (TNF-alpha) in culture; these levels were enhanced by stimulation with LPS. In animals exposed to crocidolite asbestos, two new types of cell, neutrophils and eosinophils, were recruited into the bronchoalveolar space by 1-3 days after instillation. However, the BAL profile had returned to normal by 14 days. The production of IL-1-like activity was decreased considerably compared to control from 1 to 14 days after asbestos instillation, but was increased at 30 days. However, the leucocytes produced increased TNF-alpha as early as 3 days after asbestos instillation and maintained this elevated level throughout the experimental period. Crocidolite asbestos in vitro also stimulated normal BAL leucocytes to release significantly increased amounts of IL-1-like activity and TNF-alpha. We conclude that the deposition of crocidolite asbestos fibre in the lung by instillation causes reduced production of IL-1-like activity in the acute phase, but elevated production of both IL-1-like activity and TNF in the chronic phase, suggesting that enhanced activities of these cytokines may contribute to the development of lung pathological changes in the long term.
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Affiliation(s)
- X Y Li
- Department of Medicine (RIE), University of Edinburgh, City Hospital, UK
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