Figure 7:

Systemic inflammation activates the exosomal machinery in the choroid plexus. A. Representative confocal images of CD63, RAB5, and ANXA2 (red) in the choroid plexus (CP) at 0, 4, and 8 h after LPS treatment. Hoechst (blue) was used to stain the nucleus. The dotted line indicates the ependymal cells that line the ventricle, and the square boxes indicate the zoomed insert images displayed at the right corner of each image. Scale bars, 100 μm. B, C. Representative TEM images showed the presence of MVBs in the CPE cells before (B) and 6 h after (C) LPS administration in vivo. Black arrowheads point to exosomes present in MVBs. Scale bars, 9 μm. D–F. Quantification of number of MVBs per cell section (D), number of exosomes per MVB (E), and number of exosomes per cell section (F), based on TEM analysis of several adjacent cells (0 h, n = 20; 3 h, n = 21; 4 h, n = 13; 6 h, n = 23). G–J. Quantitative real-time polymerase chain reaction (qPCR) analysis of miR-1a (G), miR-9 (H), miR-146a (I), and miR-155 (J). Data is presented as relative expression normalized with housekeeping miRs by TaqMan qPCR assay (0 h, n = 4; 1 h, n = 5; 6 h, n = 5; 24 h, n = 3). K. NanoSight analysis of CSF isolated from LPS-injected mice followed by icv injection of vehicle or GW4869, a neutral sphingomyelinase inhibitor that inhibits exosome secretion (n = 8). L. qPCR analysis of the expression of miR-1a, miR-9, miR-146a, and miR-155 in the choroid plexus of mice injected with LPS and then icv injected with vehicle (black) or GW4869 (gray) (n = 4). M. NanoSight analysis of the supernatant of choroid plexus explants from PBS- or LPS-injected mice (n = 6). Data information: Data in (D–M) are displayed as mean ± SEM and analyzed by Student’s t-test. Significance levels are indicated on the graphs: *0.01 ≤ P < 0.05; **0.001 ≤ P < 0.01; ***0.0001 ≤ P < 0.001; ****P < 0.0001. Adapted from Balusu et al. (2016)²¹³, Copyright @ EMBO Press.