Figure 5. ABCA1 influences the intracellular degradation of Aβ by microglia.

(A) Loss of Abca1 impairs Aβ degradation in primary microglia. Primary microglia from Abca1 +/+, +/− and −/− mice were treated with 2 µg/ml Aβ₄₂ for 24 hours. The cellular levels of Aβ₄₂ were measured in lysates by ELISA. The data were normalized to total protein and represent the outcome of 5 independent experiments. (B) Primary microglia from Abca1 +/+ and −/− mice were pretreated with DMSO or 1 µM GW3965 for 18 hours. The cells were then incubated with 2 µg/ml Aβ₄₂ in the presence or absence of 1 µM GW3965 for 24 hours. Cellular lysates were subjected to SDS-PAGE and Western blotted for ABCA1, ApoE, Aβ and β-actin. Representative blots from 3 independent experiments are shown. (C) Primary microglia from Abca1 +/+ and −/− mice were treated as above. Intracellular Aβ levels were quantified using ELISA for Aβ₄₂ and normalized to total protein. The data represent the outcome of 6 independent experiments (*P<0.05; ***P<0.001).