中文摘要：

目的：以人O-GlcNAc糖基转移酶（OGT）基因为靶点,研究小干扰RNA（small interference RNA,siRNA）对HEK293T细胞中OGT基因表达的抑制作用,以及这种抑制作用对tau蛋白磷酸化与糖基化修饰的影响。方法：根据人OGT基因序列特点,设计高效且特异性强的siRNA。用脂质体转染siRNA进入HEK293T细胞,通过实时PCR检测siRNA对OGT基因表达的抑制。用蛋白免疫印迹法检测tau蛋白糖基化与磷酸化修饰的变化。结果：设计的siRNA能够有效抑制OGT基因的表达,与空白组相比,抑制效率可达78.1%左右。OGT基因表达的下调使tau蛋白糖基化水平下降,而磷酸化水平增高。结论：tau蛋白的糖基化负调节其磷酸化,葡萄糖摄入减少或代谢降低可能在阿尔茨海默尔病的发生发展中起关键作用。

英文摘要：

Objective ： To investigate the inhibitory effect of small interference RNA （siRNA） targeting OGT gene on the alteration of tau phosphorylation and glycosylation level in human being. Methods： The siRNA-NC and the siRNA targeting OGT gene were chemically synthesized and transfected into HEK293T cells via lipofectamine2000. Real-time PCR was employed to evaluate the efficacy of RNA interference. The level of tau phosphorylation and glycosylation were detected by Western blot. Results： The designed siRNA could effectivly downregnlate the OGT mRNA expression to 78.1% while compared with blank group. The level of the tau phosphorylation at various sites was significantly upregnlated and the level of the tau glycosylation was downregnlated with the inhibition of OGT gene expression. Conclusion： The modification of phosphorylation and glycosylation of tau protein indicated the apparent negative correlation, which probably was induced by deficient brain glucose uptake/metabolism in Alzheimer＇s disease