Fig. 3

The glycosylation at N102-N143 and N143-N184 of SR-AI were important for oAβ internalization. COS-7 cells were transfected with human SR-AI, the single mutation of asparagine residues at 82, 102, 143, 184, 221, 249 and 267 to glutamine or the double mutation of asparagine residues at 102-143, 102-184 and 143-184 to glutamine. Cells were incubated with FAM-labeled oAβ. a and b Representative confocal images of surface-targeted SR-AI (red) and internalized FAM-oAβ (green) of the cells tranfected with SR-AI-single mutant (a) and double mutant (b). Nuclei were stained with Hoechst 33258 (blue). Scale bar, 10 μm. The result was repeated for three times (N = 3). c Relative fluorescence intensities of internalized oAβ were quantified in more than 100 SR-A-positive cells using MetaMorph software. Bars indicate mean ± SEM of at least three independent experiments. The data are presented as the percentage relative to the wild type SR-AI transfected cells. Significant differences between vector and wild type SR-AI transfected cells are indicated by ***, P < 0.001. Significant differences between wild type SR-AI transfected cells and the mutant transfected cells are indicated by #, P < 0.05