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为了探讨雌激素17β-estradiol对H2O2诱导的氧化应激的影响及其可能机制。本研究将H2O2作用于大鼠皮层神经元,利用四甲基偶氮唑盐(MTT)检测单独H2O2或者17β-estradiol存在时其对细胞活力和乳酸脱氢酶(LDH)释放的影响;检测单独H2O2或者17β-estradiol存在时其对糖原合成激酶-3β(GSK-3β)活性的影响及其对磷酸化和非磷酸化GSK-3β表达的影响;检测GSK-3β抑制剂LiCl对H2O2诱导的细胞活力的影响;检测雌激素受体抑制剂ICI-182780存在时17β-estradiol对GSK-3β表达的影响。结果显示:(1)H2O2作用于大鼠皮层神经元后显著降低细胞的活力,各种浓度的17β-estradiol预处理细胞后均能部分阻断H2O2对细胞活力的影响;(2)H2O2作用后显著增加细胞乳酸脱氢酶的释放,而17β-estradiol则部分拮抗此种作用;(3)H2O2增加了GSK-3β的活性,而提前加入17β-estradiol则可以降低H2O2诱导的GSK-3β活性增加;(4)H2O2降低了GSK-3β的磷酸化,而17β-estradiol则部分拮抗了这种作用;(5)GSK-3β抑制剂LiCl也可以拮抗H2O2诱导的细胞活力下降;(6)与对照组相比,17β-estradiol本身亦可增加GSK-3β的磷酸化,此作用可被雌激素受体抑制剂ICI-182780部分拮抗,而ICI-182780本身对GSK-3β的磷酸化无显著影响。以上结果提示,17β-estradiol可以拮抗H2O2诱导的氧化应激作用,17β-estradiol通过与其受体结合而抑制GSK-3β的活性可能是其发挥保护作用的机制之一。
To investigate the effect of estrogen 17β-estradiol on H2O2-induced oxidative stress and its possible mechanism. In this study, H2O2 was applied to rat cortical neurons. The effects of H2O2 alone or 17β-estradiol on cell viability and lactate dehydrogenase (LDH) release were measured by MTT assay. H2O2 or 17β-estradiol on glycogen synthase kinase-3β (GSK-3β) activity and its effect on the phosphorylation and non-phosphorylation of GSK-3β in the presence of H2O2, and the effect of GSK-3β inhibitor LiCl on H2O2-induced The effect of 17β-estradiol on the expression of GSK-3β was detected in the presence of estrogen receptor inhibitor ICI-182780. The results showed that: (1) H 2 O 2 significantly decreased the viability of cells in the cortical neurons of rats. After pretreatment with various concentrations of 17β-estradiol, the cell viability was partially blocked; (2) 17β-estradiol partially antagonized this effect; (3) H2O2 increased the activity of GSK-3β, while the addition of 17β-estradiol could reduce the increase of H2O2-induced GSK-3β activity ; (4) H2O2 decreased phosphorylation of GSK-3β, while 17β-estradiol partially antagonized this effect; (5) GSK-3β inhibitor LiCl can also antagonize H2O2-induced cell viability decreased; (6) 17β-estradiol itself also increased GSK-3β phosphorylation, which was partially antagonized by the estrogen receptor inhibitor ICI-182780, whereas ICI-182780 itself had no significant effect on GSK-3β phosphorylation. The above results suggest that 17β-estradiol can antagonize the H2O2-induced oxidative stress and that 17β-estradiol may inhibit the activity of GSK-3β by binding to its receptor, which may be one of the protective mechanisms.