Figure 8.

Effect of SDC3 on Aβ1–42 uptake and fibrillation in neurons. SDC3 transfectants created in SH-SY5Y cells were selected by measuring SDC3 expression with flow cytometry using APC-labeled anti-SDC3 antibody. HS expression of SDC3 transfectants, along with WT SH-SY5Y, was also measured with flow cytometry using anti-HS antibody. SDC3 transfectants and WT SH-SY5Y cells were treated with Aβ1–42 (with or without FITC label) at a concentration of 5 μM at 37 °C. Cells incubated with Aβ1–42 for 18 h were then processed for uptake, fibrillation studies and scanning electron microscopy. (a) Flow cytometry histograms representing SDC3, HS expression levels and intracellular fluorescence of Aβ1–42-treated WT SH-SY5Y cells and SDC3 transfectants. (b) Fold change in SDC3 and HS expression, along with Aβ1–42 uptake and fibrillation following SDC3 overexpression. The bars represent mean ± SEM of six independent experiments. Statistical significance vs Aβ1–42-treated WT SH-SY5Y cells (standards) was assessed by analysis of variance (ANOVA). *p < 0.05 vs Aβ1–42-treated WT SH-SY5Y cells (standards). (c,d) Linear regression between HS or SDC3 expression and Aβ1–42 uptake or fibrillation. (e) Scanning electron microscopy visualization of Aβ1–42 attachment and fibrillation on WT SH-SY5Y cells and SDC3 mutants. Representative images of three independent experiments are shown. Scale bar = 2 μm.