【摘要】 目的观察人神经母细胞瘤细胞(SH-SY5Y)对细胞外β-淀粉样蛋白(Aβ)摄取作用和在亚细胞结构定位。方法接种培养SH-SY5Y细胞,采用激光扫描共聚焦显微镜(LSCM)直接观察SH-SY5Y对细胞外Aβ1-42-fluo摄取的时程变化;用图像分析技术比较24h时SH-SY5Y对细胞外三种不同浓度Aβ1-42-fluo摄取的差异,同时采用免疫荧光多重染色分析SH-SY5Y摄入Aβ1-42-fluo的亚细胞结构定位。结果SH-SY5Y与200nmol/LAβ1-42-fluo共孵育1h后就开始摄取Aβ,Aβ被摄入的量随着时间的增加而增加;细胞外Aβ1-42-fluo浓度愈高,被摄入到细胞内Aβ1-42-fluo量也愈多,不同浓度各组间相比具有统计学差异(P<0.01或P<0.05);免疫荧光染色显示部分被内吞Aβ荧光颗粒与溶酶体标记物Lamp-1共定位。结论SH-SY5Y通过摄入Aβ机制以清除Aβ,呈时间和浓度依赖关系;被摄入的Aβ部分定位于溶酶体。更多还原

【Abstract】 Objective To observe the cellular uptake of beta amyloid protein (Aβ) by cultured human neuroblastoma (SH-SY5Y)cells and the location of Aβ in the subcellular structures. Methods The time course of cellular uptake of Aβ1-42-fluo in the SH-SY5Y cells was observed directly under laser scanning confocal microscope (LSCM). Image analysis was conducted to compare the differences of cellular Aβ uptake after treatment of the cells with different concentrations of extracellular Aβ for 24 h. Multiple immunofluorescence staining was employed to identify the location of Aβ in the subcellular structures. Results SH-SY5Y cells showed Aβ internalization after incubation with Aβ1-42-fluo (200 nmol/L) for 1 h, and the quantity of Aβ uptake was time-dependent. A higher concentration of extracellular Aβ1-42-fluo resulted in increased Aβ uptake, which differed significantly between the 3 groups with treatment at different concentrations (P<0.01 or 0.05). Immunofluorescence staining revealed a co-localization of part of the Aβ and Lamp-1 (a lysosome marker) in the cytosome. Conclusion SH-SY5Y cells can clear Aβ through a time-and dose-dependent cellular uptake mechanism. Part of the Aβ uptaken in the cytoplasm is located in the lysosome .更多还原