FIGURE 1.

The effect of Syvn siRNA or a Syvn dominant-negative mutant (C307A) on secretion of Aβ. A, APP fibroblasts transfected with Syvn or control siRNAs. After 3 days of incubation, Aβ40 and Aβ42 levels in the conditioned media were measured by ELISA as described under “Experimental Procedures.” Values are expressed as mean ± S.E. from four independent experiments. *, p < 0.05; **, p < 0.001 (two-tailed Student's t test). B, the down-regulation of Syvn by its cognate RNAi was confirmed by Western blotting with an anti-Syvn antibody. Endogenous NCT levels were assessed with an anti-NCT antibody. The upper and lower bands represent mature and immature NCT, respectively. The space between the blots indicates that they were assembled from different areas of the same blot. Exogenous APP and endogenous β-actin served as a loading control were blotted with an anti-APP monoclonal antibody and anti-β-actin antibody, respectively. C, Aβ40 and Aβ42 levels in the conditioned media harvested from APP fibroblasts overexpressing Syvn C307A or from control cells (-) were measured by ELISA. Values are expressed as mean ± S.E. from four independent experiments. *, p < 0.05; **, p < 0.001 (two-tailed Student's t test).