β-淀粉样蛋白寡聚体对人神经母细胞瘤SH-SY5Y细胞Munc-18表达的调节

β-Amyloid Oligomers Regulate Munc-18 Expression in the Human Neuroblatoma SH-SY5Y Cells

为了观察阿尔茨海默病(AD)起始因素β-淀粉样蛋白(Aβ)对Munc-18表达的调节作用,采用Zn2+诱导制备Aβ寡聚体,分化的人神经母细胞瘤SH-SY5Y细胞经纳摩尔浓度Aβ寡聚体作用后用免疫印迹和流式细胞术的方法检测SH-SY5Y细胞的Munc-18蛋白水平,用MTT法分析纳摩尔浓度Aβ寡聚体的细胞毒性。结果发现,1nmol/L Aβ寡聚体作用1天后,SH-SY5Y细胞的Munc-18蛋白水平明显下调,随后逐渐增加。高浓度的Aβ寡聚体也有相似的作用效应,但抑制Munc-18蛋白表达的效应更明显。另外,相同浓度Aβ单体对Munc-18表达没有明显的影响,纳摩尔浓度的Aβ寡聚体也没有对细胞代谢产生显著的抑制。结果表明,纳摩尔水平Aβ寡聚体对Munc-18的表达有调节作用。

This study is to explore whether the β-amyloid (Aβ), a pathogenic factor of Alzheimer’s disease, could affect Munc-18 expression. The assembly of monomer Aβ to oligomeric form was induced with Zn2+. The effect of oligomeric Aβ at low nanomolar concentration on Munc-18 expression of the differentiated human neuroblatoma SH-SY5Y cells was analyzed with western blot and flow cytometry methods. In addition, the cytotox- icity of oligomeric Aβ was also studied with MTT method. Results showed that Munc-18 protein expression signifi- cantly decreased at 1 day after 1 nmol/L Aβ oligomers treatment and followed by an increase at 2 day and 3 day. Similar changes of Munc-18 expression were also observed with higher Aβ concentration, but inhibitive effect on Munc-18 expression was more obvious. Meanwhile, oligomeric Aβ at low nanomolar concentration did not signifi- cantly inhibit metabolism of SH-SY5Y cells. We concluded that Aβ oligomers at low nanomolar concentration could regulate the expression of Munc-18 in differentiated neuroblastoma SH-SY5Y cells.