Fig. 4

Human primary pericytes take up extracellular Aβ40 via LRP1-mediated endocytosis and generate Aβ34 via BACE1-mediated enzymatic degradation. a Immunostaining of human primary pericytes with PDGFR-β, LRP1, BACE1 and DAPI (blue). (Scale bar 10 μm) b Levels of PDGFR-β and LRP1 in pericyte lysates from different passages (passage 4 (P4), passage 5 (P5) and passage 6 (P6)) assessed by western blot. Levels of BACE1 in pericyte lysate were also assessed by western blot following immunoprecipitation (IP). c Aβ34 levels in cell lysate and medium following 3 days incubation with varying concentrations of human recombinant Aβ40 peptide. Aβ34 levels were normalized and shown as fold-change compared to lowest concentration of Aβ40 treatment (1 μM). d Aβ34 levels in cell lysate and medium following incubation with 5 μM human recombinant Aβ40 peptide for varying durations. Aβ34 levels were normalized and shown as fold-change compared to shortest duration of Aβ40 treatment (12 h). e Aβ34 levels in cell lysate and medium following 2 h incubation with 10 μM IPA3 or 500 nM RAP prior to 12 h incubation with 2 μM Aβ40. Aβ34 levels were normalized and shown as fold-change compared to only Aβ40 treated cells. f Aβ34 levels in cell lysate and medium following 12 h incubation with varying concentrations of BACE1 inhibitor (Inhibitor IV) prior to 12 h incubation with 2 μM Aβ40. Aβ34 levels were normalized and shown as fold-change compared to only Aβ40 treated cells. The graphs (c-f) represent the mean ± SD. **** (p < 0.0001), *** (p < 0.001), ** (p < 0.01) and * (p < 0.05) were determined by 1-way ANOVA followed by Tukey’s multiple comparison test