摘要
【目的】探讨在以NG108-15细胞作为神经元代表、β-淀粉样蛋白25-35片段(Aβ25-35)诱导凋亡的阿尔茨海默病体外细胞模型中,人参皂苷Rg1保护神经元的作用及其机制。【方法】采用倒置显微镜观察细胞形态,结合流式细胞仪检测凋亡率,进行Aβ25-35造模浓度与时间的选择以及Rg1预处理最佳浓度时间的选择;在此基础上,采用荧光显微镜和数据处理系统(DMR)图像分析仪检测免疫细胞化学法标记的核因子-κB(NF-κB)的活性;采用免疫组化染色法检测B细胞淋巴瘤/白血病-2(Bcl-2)的表达;采用酶标光度计、半胱氨酸/天冬氨酸蛋白酶-3(caspase-3)比色检测试剂盒检测caspase-3活性。【结果】20μmol/L Aβ25-35作用24 h可诱导NG108-15细胞凋亡,2μmol/L Rg1组的NF-κB活性与模型组比较显著性提高(P<0.01),Rg1预处理组Bcl-2表达呈阳性,且caspase-3活性较模型组显著性降低(P<0.01)。【结论】高浓度聚焦状的Aβ25-35可下调神经元内NF-κB的活性,诱导细胞凋亡,Rg1通过启动神经元中NF-κB的活化从而上调Bcl-2表达,抑制caspase-3活性而发挥保护神经元的作用。
[Objective] To observe the protective effect of ginsenoside Rgl on neurons and to explore its mechanism in Alzheimer＇s disease （AD） cellular model. [Methods] With NG108-15 cell as the representative of neurons, AD cellular model was induced by β-amyloid protein 25-35 （Aβ25-35）. The optimal concentration and treating time of Aβ25-35 for the modeling as well as those of Rgl for pretreatment were screened by monitoring the morphological changes of NG108-15 with invert microscope and the apoptotic rate with flow cytometer. Then the nuclear factor-kappaB （NF-kB） activity marked by immunocytochemical method was detected with fluorescene microscope and DMR picture analysis, Bcl-2 expression assayed with SABC immunohistocheimal method, and caspase-3 activity assayed with microplate reader and caspase-3 colorimetric assay kit. [Results] Treated with 20μmol/L Aβ25-35 for 24 hours, NG10-15 cell apoptosis can be induced successfully. NF-kB activity in 2 μmol/L Rgl group was markedly increased and caspase-3 activity was obviously decreased （P 〈 0.01 as compared with the model group）, and Bcl-2 expression was positive in Rgl pretreatment group. [ Conclusion] High-concentration aggregated A,825-35 can down-regulate NF-kB activity in neurons and induce cell apoptosis. The protective mechanism of Rgl on neurons is associated with the up-regulation of Bcl-2 and inhibition of caspase-3 by switching on the activation of NF-kB in neurons.
出处
《广州中医药大学学报》
CAS
2007年第2期126-131,共6页
Journal of Guangzhou University of Traditional Chinese Medicine
基金
广东省自然科学基金项目(编号:31479)
