原花青素对Aβ_(25-35)诱导PC12细胞凋亡的影响及其机制的研究

目的　探讨原花青素(Procyanidins,PC)对β淀粉样肽25~35(βamyloidpeptide25 -35, Aβ25-35 )诱导PC12细胞凋亡的影响及其机制。方法　采用MTT比色法分析细胞存活率, Hoechst33258 PI荧光染色法检测凋亡, RT PCR检测P53和bcl 2基因mRNA表达,Westernblot检测P53和Bcl 2蛋白表达。结果　不同剂量PC预处理PC12细胞 1h可剂量依赖性对抗Aβ25-35引起的凋亡,提高细胞的存活率,减少Aβ25-35引起的核固缩,凝聚和碎裂,降低P53mRNA表达以及P53蛋白表达,增加bcl 2mRNA表达以及Bcl 2蛋白表达。结论　PC可剂量依赖性对抗Aβ25-35对PC12细胞的毒性作用,其机制可能与下调凋亡基因P53和上调抗凋亡基因bcl 2表达有关。

Effects of procyanidins on apoptosis of PC12 cells induced by Aβ25-35 and its mechanism

Aim To study the effects of Procyanidins (PC) on apoptosis of PC12 cells induced by Aβ 25-35. Methods Cell survival rate was evaluated by MTT assay, and apoptosis was analyzed by Hoechst-PI fluorescence staining. The expressions of mRNA and protein for P53 and Bcl-2 were tested by RT-PCR and Western blot. Results Pretreatment with different concentrations of PC (10~30 mg·L -1) for 1h increased the survival rate of PC12 cells in a dose-dependent fashion. PC prevented the PC12 cells nuclei from shrinkage, condensation and cleavage induced by Aβ 25-35. PC decreased the expressions of P53 mRNA and P53 protein, and increased the expression of bcl-2 mRNA and Bcl-2 protein. Conclusion These results indicated that PC can protect PC12 cells from apoptosis induced by Aβ 25-35. The mechanism of protection is likely related to decreasing P53 gene expression, and increasing bcl-2 gene expression.