| 초록 |
Dental alloys are known to release metal ions into oral cavity and to induce biological reactions mostly though oxidative stress. In this study, we developed a new method for the assessment of cellular oxidative stress with a genetically-engineered yeast, Saccharomyces cerevisiae. An oxidative-stress responding gene, superoxide dismutase 1 (SOD1), of the yeast cell was tagged with GFP, and the expression level was measured by fluorescence intensity of GFP. H2O2, an oxidant, increased fluorescence intensity dose and time dependently. Cadmium ion also induced increase of fluorescence within 1 hr at the concentrations over 1 ?M. The fluorescence response appeared at the concentrations inhibiting cell growth, suggesting that the oxidative stress generated by cadmium ion is a major factors affecting cell growth. Nickel ion did not changed the fluorescence intensity of the yeast cells even at the concentrations exhibiting suppression of yeast growth. We also tested amalgam extract and TEGDMA, a dental resin monomer, for evaluation of oxidative stress. Amalgam extract induced fluorescence dose-dependently. There was no fluorescence changes and inhibition of cell growth at all concentrations of TEGDMA. Intracellular infiltration of TEGDMA should be confirmed to conclude the absence of oxidative stress by the resin monomer. In conclusion, the yeast cell bearing SOD1-GFP developed in this study was able to response to oxidative stress and seems useful for evaluation of toxic effects of some metal ions. |
