Cell Viability and Cytokine Production of Human Alveolar Epithelial Cells Following Exposure to Sulphur Dioxide
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Abstract
Exposure to air pollutants is significantly associated with health risks ranging from bronchial reactivity to morbidity and mortality. However, the precise mechanisms are not always fully understood. The aim of this study was to investigate the effects of sulphur dioxide (SO2) on cell viability and cytokine production of A549-human pulmonary epithelial cells. Test atmospheres of SO2 were generated using a direct dilution method and calibrated by ion-chromatography. Test atmospheres were delivered to lung cells cultured on porous membranes (0.4 μm) using Harvard Navicyte horizontal diffusion chamber systems. The cytotoxic endpoints were investigated using the MTS (tetrazolium salt; Promega), NRU (neutral red uptake; Sigma) and ATP (adenosine triphosphate; Promega) assays. Expression of inflammatory markers including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were evaluated using double-antibody immunometric assays. Dose-dependent effects of SO2 were observed in A549 cells using all in vitro assays at test concentrations (10-200 ppm). The ATP assay appeared to be the most sensitive test (IC50 = 48 ± 2.83 ppm) that may related to the impaired metabolic activity of the cells following SO2 exposure. After analysis of TNF-α, no statistically significant differences were observed between control and exposed cells. However, the IL-6 production in A549 cells was significantly reduced in a dose-dependent manner (p<0.05). These results suggest that SO2 may induce a functional alteration of cells of the pulmonary epithelial preventing cells to produce adequate amounts of IL-6. IL-6 as a multifunctional proinflammatory cytokine may regulate cellular responses and plays a significant role in inflammation and tissue injury.
Klaassen CD (Ed). Casarett and Doull's Toxicology: the basic science of poisons, 6th ed. Mc Graw-Hill, New York, USA, 2001.
Chauhan AJ, Johnston SL. Air pollution and infection in respiratory illness. Br Med Bull 2003; 68 (1): 95-112.
Greenberg MI, Hamilton RJ, Phillips SD, McCluskey GJ (Eds). Occupational, Industrial, and Environmental Toxicology. 2nd ed. Mosby Inc, Philadelphia, Pennsylvania, 2003.
Winder C, Stacey NH (Eds). Occupational Toxicology, 2nd ed. CRC Press, Boca Raton, 2004.
Bakand S, Winder C, Khalil C, Hayes A. Toxicity assessment of industrial chemicals and airborne contaminants: Transition from in vivo to in vitro test methods; A review. Inhal Toxicol 2005; 17: 775-787.
Hayes A, Bakand S. Inhalation Toxicology. In: Luch A (Ed). Molecular, Clinical and Environmental Toxicology, Volume 2. Birkhäuser Publishing, Basel, 2010, pp 461-488.
Schlesinger RB, Chen LC, Zelikoff JT. Sulfur and nitrogen oxides. In: Cohen MD, Zelikoff JT, Schlesinger RB (Eds). Pulm Immunotoxicol. Kluwer Academic Publishers: Boston, 2000, pp 337-352.
McDow SR, Tollerud DJ. Outdoor air pollution. In: Greenberg MI, Hamilton RJ, Phillips SD, McCluskey GJ (Eds). Occupational, Industrial, and Environmental Toxicology. 2nd ed. Mosby Inc, Philadelphia, Pennsylvania, 2003, pp 622-635.
Knorst MM, Kienast K, Muller-Quernheim J. Effect of sulfur dioxide on cytotoxine production of human alveolar macrophages in vitro. Arch Environ Health 1996; 51: 150-156.
Winder C. Toxicology of gases, vapours and particulates. In: Winder C and Stacey NH (Eds). Occupational Toxicology. 2nd ed. CRC Press, Boca Raton, 2004, pp 399-424.
Meng Z, Liu Y, Wu D. Effect of sulphur dioxide inhalation on cytokine levels in lungs and serum of mice. Inhal Toxicol 2005; 17: 303- 307.
Bakand S, Winder C, Khalil C, Hayes A. An experimental in vitro model for dynamic direct exposure of human cells to airborne contaminants. Toxicol Let 2006; 165: 1-10.
Bakand S, Hayes A, Winder C. An integrated in vitro approach for toxicity testing of airborne contaminants. J Toxicol Environ Health Part A, 2007; 70: 1604-1612.
Bakand S and Hayes A. Throubleshooting Methods for Toxicity Testing of Airborne Chemicals In Vitro. J Pharm Toxicol Method 2010; 61: 76-85.
Bakand S, Hayes A, Winder C, Khalil C, Markovic B. In vitro cytotoxicity testing of airborne formaldehyde collected in serum-free culture media. Toxicol Ind Health 2005; 21:147-154.
Bakand S, Winder C, Khalil C, Hayes A. A novel in vitro exposure technique for toxicity testing of selected volatile organic compounds. J Environ Monit 2006; 8: 100-105.
Promega. CellTiter 96® Aqueous Non-Radioactive Cell Proliferation Assay. Technical Bulletin No 169. Promega Corporation, Madison, USA, 2001.
Babich H, Borenfreund E. Neutral red assay for toxicology in vitro. In: Watson, RR (Ed). In Vitro Methods of Toxicology. CRC Press Inc, Boca Raton, 1992, pp 237-252.
Borenfreund E, Babich H. The neutral red cytotoxicity assay, INVITTOX Protocol 64.1992; Available from: http://ecvam-sis.jrc.it/invittox/static/index.html.
Promega. CellTiter-GIO Luminescent Cell Viability Assay. Technical Bulletin No. 288. Promega Corporation, Madison, USA, 2004.
OSHA. Sulfur Dioxide in Workplace Atmospheres, Method Number: ID-104. US Occupational Safety & Health Administration. 1989.
Bakand S, Hayes A, Winder C. Development of in vitro methods for toxicity testing of workplace air contaminants. Int J Occup Hyg 2009; 1 (1): 27- 34.
Driscoll KE. Cytokines and regulation of pulmonary inflammation. In: Gardner DE, Crapo JD and McClellan RO (Eds). Toxicology of the Lung, 3rd ed. Taylor & Francis, Philadelphia, 1999, pp 149-172.
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| Issue | Vol 3 No 2 (2011) | |
| Section | Articles | |
| Keywords | ||
| Adenosine triphosphate Interleukin-6 In vitro cytotoxicity Neutral red uptake Sulphur dioxide Tetrazolium salt Tumor necrosis factor-a | ||
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