EGCG对H2O2诱导的螺旋神经节细胞MnSOD基因表达的影响

目的：探讨表没食子儿茶素没食子酸盐（EGCG）在双氧水（H2O2）诱导耳蜗螺旋神经节细胞（SGCs）氧化损伤中对线粒体抗氧化酶基因-MnSOD基因表达的影响。方法：培养离体SGCs，采用半定量RT-PCR方法检测加入不同浓度H2O2和/或EGCG后螺旋神经元MnSOD基因的表达情况。以经典抗氧化剂维生素C作对照。结果：随着H2O2浓度提高，MnSOD基因的表达亦随之升高；在H2O2浓度大于100 μmol/L时MnSOD基因表达明显上调(P<0.05)，100 μg/ml EGCG能明显抑制H2O2诱导的MnSOD基因表达(P<0.05)。 结论：EGCG可能通过清除氧自由基，提高MnSOD酶活性，抑制H2O2诱导的螺旋神经节细胞MnSOD基因表达。

Effect of EGCG on H2O2 -induced MnSOD gene expression in cultured spiral ganglion cells

OBJECTIVE: To investigate the influence of EGCG on H2O2-induced gene expression of manganese superoxide dismutase (MnSOD or SOD2) in cultured spiral ganglion cells (SGCs) in vitro. METHODS: SGCs were cultured in vitro, and H2O2 and/or EGCG in different concentrations were used. Semi-quantitative RT-PCR was applied to observe MnSOD gene expression in SGCs after H2O2 and EGCG treatment. RESULTS: The expression of MnSOD gene was up-regulated with the increase of the concentration of H2O2 in cultured SGCs, and MnSOD gene expression was significantly up-regulated at a dose of H2O2 > or =100 micromol/L. However, this up-regulation was suppressed after simultaneously treated with 100 microg/ml EGCG. CONCLUSION: EGCG suppresses H2O2-induced up-regulation of MnSOD gene expression in cultured SGCs by getting rid of oxygen free radicals, reinforcing the activity of antioxidant enzymes such as MnSOD, and protects cultured SGCs from H2O2-induced oxidizing damage.