雌激素对Aβ25-35致PC12细胞损伤的影响

Effects of estrogen on PC12 cell damage due to Aβ25-35

目的观察可溶性Aβ25-35作用下PC12细胞细胞活力的改变及17β-雌二醇(17βE2)对此改变的影响。方法培养的PC12细胞作为神经细胞体外模型,可溶性Aβ25-35作用于PC12细胞作为AD早期病理损害的细胞模型,实验设空白对照组、Aβ损伤组、雌激素干预组,雌激素干预组再分为五个剂量亚组,分别于培育各时间点(0.5,6,24,48,72 h),用噻唑蓝(MTT)法检测细胞活力,乳酸脱氢酶(LDH)法检测细胞损伤程度。结果Aβ损伤组与空白对照组相比,PC12细胞代谢活力(MTT还原率)明显降低(P<0.01),细胞培养液上清中LDH漏出明显增多(P<0.01),以上损伤出现较早,并随着时间的延长而加重。与Aβ损伤组比较,在10-9-10-6mol/L各浓度下,17βE2组细胞MTT还原率均有显著提高,细胞培养液上清LDH漏出均有显著降低,且有剂量依赖性。结论超生理量的Aβ即使呈可溶解状态也可以对神经元细胞造成毒性损害,雌激素具有剂量依赖性的抗Aβ损伤和神经细胞保护作用。

Objective To investigate the change of viability of PC12 cells acted by soluble Aβ25-35 and the effect of 17β-estradiol （17βFe） on this change. Methods PC12 cells were divided into 3 groups： blank group, Aβ group （treated with 5 μmol/L soluble Aβ25-35）, and 17βE2 intervention group （treated with 5 μmol/L soluble Aβ25-35 plus 17β-E2）. For 17βE2 intervention group, PC12 cells were again divided into five subgroups according to concentration gradient. Cell viability was detected by MTT method and degree of injury by lactate dehydrogenase （LDH） method at 0.5,6,24,48 and 72 h respectively after adherence. Results Compared to blank group, OD570 for Aβ group decreased significantly （P〈0.01） and leakage concentrations of LDH for Aβ group increased significantly （P〈0.01） at every time point and dynamically in a time-dependent manner. For 10^-9 - 10^-6mol/L 17βE2 intervention groups, MTT reduction increased significantly compared to Aβ group （P〈0.01） at every time point except 0.5 h in a dose-dependent manner, and leakage concentrations of LDH decreased significantly （P〈0.01 or P〈0.05） at every time point in a dose-dependent manner. Conclusion Ultra-physiologic dose Aβ, even in soluble form, is of toxic action early and time-dependently on neurons with their viability cutting down and membrane integrity damage. PC12 cells injured by soluble Aβ25-35 can be used as cell model that represents earlier pathological lesion of AD. Estrogen has anti-Aβ and neuroprotective effect in a dose-dependent manner.