Fig. 3

Fig. 3

Mrc1a-positive perivascular cells are Fluorescent Granular Perithelial cells (FGPs).

(a,b) Yellow/green epifluorescence microscopic images of the optic lobes (top) and a portion of the cerebellum of the dissected brain of a non-transgenic wild type adult zebrafish (n = 3 adult brains). Dorsal views rostral at top. Box in a shows region imaged in panel b, where autofluorescent granules are clearly visible in close association with blood vessels. (c,d) Confocal images of Mrc1a:eGFP-positive perivascular cells (green) filled with numerous vacuoles closely apposed to Kdrl:mCherry-positive blood vessels (grey) on the surface of the optic lobe of a dissected brain of a Tg(mrc1a:eGFP);Tg(kdrl:mCherry) double-transgenic adult zebrafish (n = 3 adult brains). Box in panel (c) shows region imaged in panel d. (e) Confocal and transmitted light (grey) overlay image of Lyve1:dsRed-positive perivascular cells (magenta) filled with large vacuoles (black arrows) in the brain of an adult Tg(lyve1:dsRed) transgenic zebrafish (n = 3 adult brains). Dashed lines demarcate an adjacent blood vessel. (f) Confocal image of the same Lyve1:dsRed-positive cells (magenta) showing that the vacuoles are all yellow autofluorescent (green, white arrows). (g) Confocal image of a transverse section through the brain of an adult mouse, at the level of the cerebral cortex, stained with anti-CD206 (MRC1; green) and DAPI (magenta), n = 3 brains, three sections. (h) Higher magnification confocal images of the brain section imaged in panel g, showing CD206-positive cells on the outermost surface of the brain. (i,j) Confocal images of Mrc1a:eGFP-positive perivascular cells (green) containing numerous vacuoles (red and black) on the surface of an optic lobe of a dissected brain of a Tg(mrc1a:eGFP) transgenic adult zebrafish injected intracranially with India ink. Panel (j) shows transmitted light image. Yellow dotted lines in j represent the outline of Mrc1a:eGFP-positive cells. Black vacuoles contain India ink internalized by Mrc1a:eGFP-positive cells (n = 3/10 injected brains). (k,l) Confocal images of Mrc1a:eGFP-positive perivascular cells (green) on Kdrl:mCherry-positive blood vessels (magenta) on the surface of the optic lobes of dissected brain of a normally (k) fed and high cholesterol diet (HCD) fed (l) Tg(mrc1a:eGFP);Tg(kdrl:mCherry) double-transgenic adult zebrafish (n = 3 per treatment). (m,n) Quantification of average FGP cell length (panel m; T-test, p-value=1.7×10⁻¹⁰, n = 347 FGPs from 3 adult brains) and average vacuole number (panel n; T-test, p-value=9.2×10⁻⁶, n = 354 FGPs from 3 adult brains) in control versus HCD fed Tg(mrc1a:eGFP);Tg(kdrl:mCherry) double-transgenic adult zebrafish. Scale bars: 50 µm (c,d), 10 µm (e,f), 500 μm (g), 20 μm (h), 25 µm (i,j), 50 µm (k,l).