FIGURE 6.

Degradation of Aβ in microglia. A, Aβ42 (25 μm) was incubated in the presence or absence of N2a-derived exosomes at 37 °C for 5 h. The incubation mixtures were subsequently administered to BV-2 cells (final concentration of Aβ, 0.5 μm) for 3 h. After removal of free Aβ and exosomes by washing in medium, the cells were further cultured for up to 48 h. Intracellular levels of Aβ42 were determined at the indicated times by ELISA. B, exosomes were labeled with PKH26 (red) and added to cultures of BV-2 cells. After a 3-h incubation, cells were stained with LysoTracker Green and analyzed by confocal microscopy. Scale bar, 5 μm. C, PKH26-labeled exosomes were mixed with the fluorescent FAM-coupled Aβ42 (25 μm). After a 5-h incubation, the mixtures were administered to cultures of BV-2 cells for 3 h and stained with LysoTracker Blue. Scale bar, 5 μm.