(A) Experimental design and representative images of immunostaining showing sEVs are internalized by primary microglia, neurons, and astrocytes. PKH26 labeled sEVs (red) are taken up by cells labeled for specific markers; primary microglia (anti-CD11b), neurons (anti-NeuN), and astrocytes (anti-GFAP). Scale bar = 20 µm. (B) Schematic of in vitro experiment and qPCR analysis of miRNAs in recipient cells incubated with sEVs. The sEVs isolated from RAW 264.7 cell conditioned media from naïve (Exo(−) or after 24 h stimulation with 1µg LPS (Exo(+) were incubated with primary cells for 24 hours. Exo(+) sEVs treatment increased relative levels of miR-146a, miR-146b and miR-21 in recipient cells. Expression of miR-146a, miR-146b and miR-21 were normalized to U6 snRNA (n=3). All data shown as mean ± SEM and analyzed with one-way ANOVA *p < 0.05, **p <0.01.