雌激素对NMDA诱导离体大鼠海马神经元凋亡的作用

Effect of estrone on hippocampal neuronal apoptosis induced by NMDA in rat primary culture

目的观察雌激素对NMDA诱导离体海马神经元凋亡的作用,探讨雌激素的神经保护作用机制。方法用形态学鉴定和细胞死亡率的测定以及Western blot方法分析雌激素对NMDA诱导神经元凋亡的作用。结果培养的神经细胞经形态学鉴定绝大多数是神经元,占总细胞数目的81·3%,凋亡细胞百分数为15·1%,NMDA(300μmol·L-1+甘氨酸5μmol·L-1)能明显诱导神经元凋亡,凋亡发生数为31·6%(与对照组相比P<0·05),雌激素(300μmol·L-1)能明显拮抗NMDA的凋亡毒性作用,凋亡发生数为18·2%(与对照组相比P>0·05)。MTT实验测定细胞生存率:NMDA组为70·2%(与对照组相比P<0·05),NMDA+雌激素组为89·7%(与对照组相比P>0·05)。蛋白印迹也显示,caspase-3的活性能被雌激素所抑制。结论雌激素具有神经保护作用,作用机制可能通过抑制凋亡相关酶的活性来实现。实验结果为开发雌激素的临床应用和寻找神经保护作用药物提供实验参考依据。

Aim To observe the action of estrone on the hippocampal neuronal apoptosis induced by NMDA in vitro and to analyse the mechanism underlying the neuroprotection of estrone. Methods The methods of both morphological analysis and cell viabilities were used, and Western blot was also used to analyce the role of antitoxiciy of estrone. Results The cultures were conformed with fluorescent dye of Hoechst 33258 and NeuN. About 31.6% neurons were induced into apoptosis by NMDA （300μmol · L^-1 ＋ glycine 5μmol · L^-1, compared with control group, P 〈 0. 05 ）, estrone（300μmol · L^-1） can inhibit the apoptotic action of NMDA （ compared with control group, P 〉 0. 05 ）.MTT test also showed that estrone can protect cultures from apoptosis induced by NMDA, it can raise the cell viabilities exposed to NMDA. Western blot showed that activities of caspase-3 can be inhibited by estrone, the segments of caspase-3 can diminished after application of estrone together with NMDA. Conclusion Estrone had neuronal protection, this role maybe relate to the inhibition of caspase-3, a common pathway in apoptosis. The results can provide some clues to the explovation of the clinical use of estrone and to the development of a neuronal protective drug.