齐墩果酸对Aβ25-35诱导PC12细胞凋亡的影响及机制研究

Effects of oleanic acid on apoptosis of PC12 cells induced by Aβ25-35

目的研究琐琐葡萄提取物齐墩果酸(oleanolic acid,OA)对β淀粉样蛋白25-35(Aβ25-35)诱导PC12细胞凋亡的保护作用及其机制。方法采用20μmol/L Aβ25-35诱导PC12细胞损伤构建阿尔茨海默病(AD)细胞模型,20、40和80μg/mL OA干预,CCK-8法检测各组细胞的存活率,乳酸脱氢酶(LDH)法检测细胞膜通透性及完整性,Annexin V-FITC流式细胞术检测细胞凋亡率,实时荧光定量PCR(real-time PCR)检测细胞凋亡相关基因bcl-2和bax表达。结果与模型组比较,20、40和80μg/mL OA预处理可有效提高PC12细胞存活率,减少乳酸脱氢酶渗漏,降低细胞凋亡率,下调bax mRNA表达(P<0.05),40、80μg/mL OA预处理上调bcl-2 mRNA表达(P<0.05)。结论 OA对Aβ25-35诱导的PC12细胞凋亡损伤具有明显的保护作用,其机制可能与OA通过调节细胞凋亡相关基因表达,从而抑制凋亡有关。

[Objective] To investigate protective effects of oleanic acid on apoptosis of PC12 cells induced by β-amyloidprotein （Aβ25-35）. [Methods] The PC12 cells were divided into control group, model group in- duced by Aβ25-35, OA groups （OA at 80, 40, 20 μg/mL were added into the cultures of PC12 cells in the presence of 20 mol/L Aβ25-35）. Cell viability was detected by CKK-8 method. The content of LDH was determined by Mieroplate Reader method. The apoptotic rates were examined by Annexin V - FITC and staining with PI. The mRNA expression of bcl-2 and bax was quantified by real-time PCR. [Results] Cells were injuried by Aβ25-35 in model group. Compared with the model group, cell viability was improved, the content of LDH in supernatant fluid was reduced, and the apoptotie rates was reduced in OA groups （P 〈 0.05）. In addition, mRNA expression of bcl-2 increased and that of bax decreased （P〈0.05）, then between 20 μg/mL OA group and model group bcl-2 transcription level was not different. [Conclusion] OA inhibits apoptosis of PC12 cells induced by Aβ25-35, which may be involved adjust Bcl-2 and Bax gene expression in the mechanism of anti-apoptosis.