Figure 3. PGRN–sortilin interaction enhances PSAP uptake in primary cortical neurons.

(a) Primary cortical neurons (DIV12) were pretreated with either GST-RAP (50 μg ml⁻¹) or PBS (control) for 30 min, and were then treated with recombinant hPSAP (1 μg ml⁻¹) and/or hPGRN (1 μg ml⁻¹), hPGRNΔ3aa (1 μg ml⁻¹) in the presence or absence of GST-RAP (50 μg ml⁻¹) for 16 h as indicated. (b) Quantification of endocytosed neuronal PGRN in (a), normalized to PGRN alone (set as 100%). n=3, ***, P<0.001, Repeated Measures ANOVA. Data are presented as mean±SEM.