中文摘要：

目的以铝致神经母细胞瘤细胞（SH—SY5Y）为模型，研究用RNA干扰的方法阻抑bak基因的表达，找到其最优的序列、最适的转染浓度和转染时间，以减少铝引起的神经细胞凋亡。方法将三对bak基因小干扰RNA（siRNA）序列用不同浓度铝染毒细胞，分别测定不同的siRNA序列、不同的转染浓度及不同的转染时间对细胞活力的影响。用荧光染色法计数转染效率，用荧光定量PCR法检测干扰效率，用免疫组织化学染色法测定阻抑Bak蛋白表达效果。最后，用选定的bak siRNAl作用于染铝后的神经瘤细胞，并检测其对细胞的凋亡率及坏死率的影响。结果siRNAI序列为最有效的序列，最适转染浓度为10nmol／L，最适作用时间为转染后24h。siRNA的转染效率〉90％，最大干扰效率为57．76％，并表现了对Bak蛋白表达的明显的阻抑效应。bak siRNAI作用于染铝后的神经瘤细胞，可以明显降低细胞的凋亡率，但对细胞的坏死率的影响并不明显。结论凋亡是铝致SH-SY5Y细胞死亡的重要途径，针对bak基因，用化学法合成siRNA并将其导人神经细胞，可以有效降低bak基因和Bak蛋白的表达，提高细胞活力和降低细胞的凋亡率，为预防及治疗铝诱导的神经细胞凋亡及神经退行性变的发生发展提供理论依据。

英文摘要：

Objective To find the optimal design of small interfering RNA compounds,transfection concentration and transfection time to reduce the M-induced apoptosis in SH-SY5Y ceils. Methods Three siRNA sequences on bak gene were designed and transfected into SH-SY5Y ceils, which were treated at various concentrations of aluminum. Ceil viability was detected by CCK-8 kit on different siRNA sequences,various transfection concentrations, and diverse transfection courses. Transfection efficiency was determined by fluorescent staining of CY3, and interference efficiency was measured by QRT-PCR. Besides, immunohistochemical staining was used to express Bak protein content. Finally,apoptotic rate and necrotic rate in AI treated SHSY5Y ceils transfecting by the selected bak siRNA1 were detected. Results Based on the viability of siRNA sequences, siRNA1 was selected as the optimal siRNA sequences. The optimal transfection concentration was 10 nmol/L,and the optimal time course was 24 h after transfection. The transfection efficiency was above 90% and the interference efficiency with bak gene was 57.76%. Furthermore, there was significant transfection effect on Bak protein. The apoptotic rate in AI treated SH-SY5Y ceils were significantly decreased by bak siRNAI transfection. Conclusion Apoptosis is one of the major ceil death pathways in SH-SY5Y ceils induced by aluminum. When chemically synthesized siRNA is inducted to neural ceils,it can significantly reduce bak gene level,decrease Bak protein expression and apoptotic rate,which may serve as the basis for preventing neural ceils apoptosis and inhibiting the development of neurodegenerative diseases.