[Morphological observation of cellular uptake of beta amyloid protein in cultured human neuroblastoma cells].
OBJECTIVE
To observe the cellular uptake of beta amyloid protein (Abeta) by cultured human neuroblastoma (SH-SY5Y) cells and the location of Abeta in the subcellular structures.


METHODS
The time course of cellular uptake of Abeta1-42-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 Abeta uptake after treatment of the cells with different concentrations of extracellular Abeta for 24 h. Multiple immunofluorescence staining was employed to identify the location of Abeta in the subcellular structures.


RESULTS
SH-SY5Y cells showed Abeta internalization after incubation with Abeta1-42-fluo (200 nmol/L) for 1 h, and the quantity of Abeta uptake was time-dependent. A higher concentration of extracellular Abeta1-42-fluo resulted in increased Abeta 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 Abeta and Lamp-1 (a lysosome marker) in the cytosome.


CONCLUSIONS
SH-SY5Y cells can clear Abeta through a time- and dose-dependent cellular uptake mechanism. Part of the Abeta uptaken in the cytoplasm is located in the lysosome .
Qian
Yi-hua
YH
Department of Human Anatomy and Histology-Embryology, Xi'an Jiaotong University College of Medicine, Xi'an, China. qianyh38@mail.xjtu.edu.cn
Hu
Xiao-dan
XD
Han
Hua
H
Liu
Yong
Y
D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology*; D010446:Peptide Fragments / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)