Cellular oxidative damage of HEK293T cells induced by combination of CdCl₂ and Nano-TiO₂

Abstract

This study investigated the conjoined cellular oxidative damage of human embryo kidney 293T (HEK293T) cells induced by cadmium chloride (CdCl₂) and nanometer titanium dioxide (nano-TiO₂). RT-PCR technique was used to detect the expressions of Heme oxygenase-1 (HO-1) and 8-oxoguanine DNA glycosylase (OGG1). The activities of superoxide dismutase (SOD) and catalase enzyme (CAT) and concentrations of reactive oxygen species (ROS) and maldondialdehyde (MDA) were measured by different approaches. The results showed that CdCl₂ and nano-TiO₂ at a low concentration of 0.75 total toxic unit (TU) exerted an additive effects on HO-1 gene expression, CAT activities and MDA concentrations. When the total TU was increased to 1 or 1.25 TU, the interaction was synergetic. Moreover, the mixture with high proportion of CdCl₂ produced an additive effect on the OGG1 gene expression, and the interaction was changed to be synergetic when the concentration of CdCl₂ was lower than or equal to that of nano-TiO₂. Synergetic effects of CdCl₂ and nano-TiO₂ on cellular oxidative damage of HEK293T cells were found as indicated by the changes in the SOD activities and ROS concentrations. It was concluded that CdCl₂ and nano-TiO₂ exerts synergistic effects on the cellular oxidative damage of HEK293T cells, and the sensitivity of these indicators of oxidative damage varies with the proportion of CdCl₂ and nano-TiO₂ in the mixture.

Keywords

cadmium chloride / nano-TiO₂ / oxidative damage / HEK293T cells

References

[1] IARC.. Beryllium, cadmium, mercury, and exposures in the glass manufacturing industry. Working Group views and expert opinions, Lyon, 9–16 February 1993. IARC Monogr Eval Carcinog Risks Hum, 1993, 58: 1-415

[2] ShaikhZ.A., VuT.T., ZamanK.. Oxidative stress as a mechanism of chronic cadmium-induced hepatotoxicity and renal toxicity and protection by antioxidants. Toxicol Appl Pharmacol, 1999, 154(3): 256-263

[3] BanfalviG., LittlefieldN., HassB., et al.. Effect of cadmium on the relationship between replicative and repair DNA synthesis in synchronized CHO cells. Eur J Biochem, 2000, 267(22): 6580-6585

[4] CasalinoE., SblanoC., CalzarettiG., et al.. Acute cadmium intoxication induces alpha-class glutathione S-transferase protein synthesis and enzyme activity in rat liver. Toxicology, 2006, 217(2-3): 240-245

[5] IkediobiC.O., BadisaV.L., Ayuk-TakemL.T., et al.. Response of antioxidant enzymes and redox metabolites to cadmium-induced oxidative stress in CRL-1439 normal rat liver cells. Int J Mol Med, 2004, 14(1): 87-92

[6] KarmakarR., BanerjeeA., DattaS., et al.. Influence of cadmium intoxication on hepatic lipid peroxidation, glutathione level, and glutathione S-transferase and gamma-glutamyl transpeptidase activities: correlation with chromosome aberrations in bone marrow cells. J Environ Pathol Toxicol Oncol, 1999, 18(4): 277-287

[7] KoizumiT., ShirakuraH., KumagaiH., et al.. Mechanism of cadmium-induced cytotoxicity in rat hepatocytes: cadmium-induced active oxygen-related permeability changes of the plasma membrane. Toxicology, 1996, 114(2): 125-134

[8] MikhailovaM.V., LittlefieldN.A., HassB.S., et al.. Cadmium-induced 8-hydroxydeoxyguanosine formation, DNA strand breaks and antioxidant enzyme activities in lymphoblastoid cells. Cancer Lett, 1997, 115(2): 141-148

[9] YanoC.L., MarcondesM.C.. Cadmium chloride-induced oxidative stress in skeletal muscle cells in vitro. Free Radic Biol Med, 2005, 39(10): 1378-1384

[10] LinC., LinK.S.. Photocatalytic oxidation of toxic organohalides with TiO₂/UV: the effects of humic substances and organic mixtures. Chemosphere, 2007, 66(10): 1872-1877

[11] QuanX., ZhaoX., ChenS., et al.. Enhancement of p,p′-DDT photodegradation on soil surfaces using TiO₂ induced by UV-light. Chemosphere, 2005, 60(2): 266-273

[12] GurrJ.R., WangA.S., ChenC.H., et al.. Ultrafine titanium dioxide particles in the absence of photoactivation can induce oxidative damage to human bronchial epithelial cells. Toxicology, 2005, 213(1–2): 66-73

[13] KarlssonH.L., CronholmP., GustafssonJ., et al.. Copper oxide nanoparticles are highly toxic: a comparison between metal oxide nanoparticles and carbon nanotubes. Chem Res Toxicol, 2008, 21(9): 1726-1732

[14] RahmanQ., LohaniM., DoppE., et al.. Evidence that ultrafine titanium dioxide induces micronuclei and apoptosis in Syrian hamster embryo fibroblasts. Environ Health Perspect, 2002, 110(8): 797-800

[15] SayesC.M., WahiR., KurianP.A., et al.. Correlating nanoscale titania structure with toxicity: a cytotoxicity and inflammatory response study with human dermal fibroblasts and human lung epithelial cells. Toxicol Sci, 2006, 92(1): 174-185

[16] WamerW.G., YinJ.J., WeiR.R.. Oxidative damage to nucleic acids photosensitized by titanium dioxide. Free Radic Biol Med, 1997, 23(6): 851-858

[17] WangJ., ZhouG., ChenC., et al.. Acute toxicity and biodistribution of different sized titanium dioxide particles in mice after oral administration. Toxicol Lett, 2007, 168(2): 176-185

[18] GallegoA., Martin-GonzalezA., OrtegaR., et al.. Flow cytometry assessment of cytotoxicity and reactive oxygen species generation by single and binary mixtures of cadmium, zinc and copper on populations of the ciliated protozoan Tetrahymena thermophila. Chemosphere, 2007, 68(4): 647-661

[19] BertinG., AverbeckD.. Cadmium: cellular effects, modifications of biomolecules, modulation of DNA repair and genotoxic consequences (a review). Biochimie, 2006, 88(11): 1549-1559

[20] LiN., SioutasC., ChoA., et al.. Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage. Environ Health Perspect, 2003, 111(4): 455-460

[21] AfaqF., AbidiP., MatinR., et al.. Cytotoxicity, pro-oxidant effects and antioxidant depletion in rat lung alveolar macrophages exposed to ultrafine titanium dioxide. J Appl Toxicol, 1998, 18(5): 307-312

[22] HussainS.M., HessK.L., GearhartJ.M., et al.. In vitro toxicity of nanoparticles in BRL 3A rat liver cells. Toxicol In Vitro, 2005, 19(7): 975-983

[23] JinC.Y., ZhuB.S., WangX.F., et al.. Cytotoxicity of titanium dioxide nanoparticles in mouse fibroblast cells. Chem Res Toxicol, 2008, 21(9): 1871-1877

[24] LongT.C., SalehN., TiltonR.D., et al.. Titanium dioxide (P25) produces reactive oxygen species in immortalized brain microglia (BV2): implications for nanoparticle neurotoxicity. Environ Sci Technol, 2006, 40(14): 4346-4352

[25] LongT.C., TajubaJ., SamaP., et al.. Nanosize titanium dioxide stimulates reactive oxygen species in brain microglia and damages neurons in vitro. Environ Health Perspect, 2007, 115(11): 1631-1637

[26] PetersK., UngerR.E., KirkpatrickC.J., et al.. Effects of nano-scaled particles on endothelial cell function in vitro: studies on viability, proliferation and inflammation. J Mater Sci Mater Med, 2004, 15(4): 321-325

[27] ChenG., ZhaoJ., LiuX., et al.. Electrochemical sensing DNA damage with nano-titanium dioxide and repair with a medicinal herb species resveratrol. J Biotechnol, 2007, 127(4): 653-656

[28] LlesuyS.F., TomaroM.L.. Heme oxygenase and oxidative stress. Evidence of involvement of bilirubin as physiological protector against oxidative damage. Biochim Biophys Acta, 1994, 1223(1): 9-14

[29] PossK.D., TonegawaS.. Heme oxygenase 1 is required for mammalian iron reutilization. Proc Natl Acad Sci USA, 1997, 94(20): 10919-10924

[30] SuttnerD.M., SridharK., LeeC.S., et al.. Protective effects of transient HO-1 overexpression on susceptibility to oxygen toxicity in lung cells. Am J Physiol, 1999, 276(3Pt1): L443-451

[31] GabelovaA., ValovicovaZ., LabajJ., et al.. Assessment of oxidative DNA damage formation by organic complex mixtures from airborne particles PM(10). Mutat Res, 2007, 620(1-2): 135-144

[32] XiaT., KovochichM., BrantJ., et al.. Comparison of the abilities of ambient and manufactured nanoparticles to induce cellular toxicity according to an oxidative stress paradigm. Nano Lett, 2006, 6(8): 1794-1807

[33] ShinmuraK., KasaiH., SasakiA., et al.. 8-hydroxyguanine (7,8-dihydro-8-oxoguanine) DNA glycosylase and AP lyase activities of hOGG1 protein and their substrate specificity. Mutat Res, 1997, 385(1): 75-82

[34] ParkE.J., YiJ., ChungK.H., et al.. Oxidative stress and apoptosis induced by titanium dioxide nanoparticles in cultured BEAS-2B cells. Toxicol Lett, 2008, 180(3): 222-229