Fig. 1

Analysis of extracellular vesicles (EVs) in cerebrospinal fluid (CSF) and choroid plexus (CP) of APP/PS1 mice. (a, b) nanoparticle Tracking Analysis (NTA; NanoSight) quantification (a) of CSF particles from 4 (n = 15 and n = 9), 7 (n = 20 and n = 13), 20 (n = 7 and n = 5) and 38 (n = 8 and n = 17) weeks old wild-type (WT) (black) and APP/PS1 (grey) mice. Size distribution (b) of CSF particles from 7 weeks old WT (black) (n = 20) and APP/PS1 (grey) (n = 13) mice. (c) Representative confocal images of ALIX, AnnexinA2 (ANXA2), CD63, Flotillin1 (FLOT1) and RAB5 (red) in the CP of 7 weeks old WT and APP/PS1 mice (n = 3). Nuclei are counterstained with Hoechst (blue) and the ependymal cell layer lining the ventricle wall is indicated by the white line. Scale bar represents 100 µm in the overview images and 10 µm in the zoomed-in images. (d, e) Quantification (d) and representative transmission electron microscopy (TEM) images (e) of 10 weeks old WT (black) and APP/PS1 (grey) mice (n = 4). Amount of multivesicular bodies (MVBs) per cell section and amount of intraluminal vesicles (ILVs) per cell section are displayed. Two regions of 20 CPE cells were manually counted for each biological replicate, resulting in the average amount of MVBs and ILVs in 40 CPE cells per cell section. White arrow heads point to ILVs present in MVBs. Scale bar represents 10 µm in the overview images and 1 µm in the zoomed-in images