二苯乙烯苷对神经细胞淀粉样肽前体蛋白表达的影响及其与CREB调节相关的作用机制

摘要

目的 探讨二苯乙烯苷(tetrahydroxystilbene glucoside,TSG)对培养神经细胞淀粉样肽前体蛋白(amyloid precursor protein,APP)表达的影响及其作用机制.方法 应用Western blotting法检测APP和cAMP效应元件结合蛋白(cAMP responsive element-binding protein,CREB)的表达.用Matinspector软件分析APP启动子区CRE顺式反应元件;构建不同长度APP启动子区荧光素酶表达质粒;用双荧光素酶报告基因系统检测细胞中荧光素酶活性.结果 由Forskolin激活SH-SY5Y细胞中CREB的同时可下调APP表达,成功构建了含有CRE元件的APP启动子区荧光素酶表达质粒.TSG能够抑制SH-SY5Y细胞内APP表达,并对APP启动子转染细胞内含有CRE1和2的APP荧光素酶报告基因质粒表达有显著抑制作用.结论 TSG能够下调神经细胞中APP的表达,其机制可能与影响CREB与CRE元件的结合有关.%Objective To explore the effects of tetrahydroxystilbene glucoside (TSG) on the expression of amyloid precursor protein (APP) and its mechanism in cultured nerve cells.Methods The expression of APP and cAMP responsive element-binding protein (CREB) was detected by Western blotting assay.The CRE cis-elements of APP promoter were analyzed by Matinspector software.The plasmids expressing serial deletion mutants of APP promoter were constructed.The luciferase activity in cells was measured by luciferase double reporter gene system.Results Activation of CREB by Forskolin down-regulated APP expression in SH-SY5Y cells.The luciferase expression plasmids of APP promoter containing CRE elements were successfully constructed.TSG treatment decreased APP level in SH-SY5Y cells,and reduced luciferase activity of APP reporter gene containing CRE1 and CRE2 cis-elements in APP promoter plasmidstransfected cells.Conclusion TSG down-regulated APP expression in nerve cells,and its mechanism may be related to affecting the binding of CREB with CRE eis-elements.