Effects of nano-sized and micro-sized silicon dioxide on expression levels of antioxidant enzymes in HaCaT cells

Objective To explore the effects of 15 nm and 100 nm SiO2 on expression levels of 3 oxidative-stress-related proteins including Cu-Zn superoxide dismutase-1(SOD-1),catalase(CAT) and glutathione reductase(GSR) in HaCaT cells. Methods HaCaT cells were treated with 15 nm and 100 nm SiO2 at the concentrations of 5.0,10.0,15.0 mg/L for 24 hours,respectively.The protein levels of SOD-1,CAT and GSR were analyzed by the method of Western blotting. Results Compared with those of the control,the treatment with 15 nm and 100 nm SiO2 could significantly alter the expression levels of SOD-1,CAT and GSR.When treated with 15 nm SiO2,the changes of SOD-1,CAT and GSH were down-regulated along with the SiO2 concentration increased.On the other hand,these 3 antioxidant enzymes were up-regulated along with 100 nm SiO2 concentration increased. Conclusion The data indicated that alternation of protein levels of antioxidant enzymes could be involved in cytotoxicity of HaCaT cells induced by 15 nm and 100 nm SiO2.The biological effects were related closely with particle size in HaCaT cells.