Fig. 2
From: Loss of the transcription factor RBPJ induces disease-promoting properties in brain pericytes
Ultrastructural changes and blood flow assessment in RbpjiPC brains. a Electron micrographs of P10 brain cortex capillaries. Note EC hyperplasia and lumen deformation in mutant. EC junctions are not compromised (arrows). Bottom panel shows higher magnification of the boxed inset in RbpjiPC for better appreciation of electron-dense and continuous junctions. The basement membrane between RbpjiPC ECs (E) and pericytes (P) is notably enlarged (arrowhead). Scale bar, 2 μm. b Electron micrographs of mouse brain cortex capillaries at P10. ECs (E), pericytes (P), astrocyte endfeet (A), and basement membrane (black arrowhead) are indicated. Note vacuolization (black arrows) in RbpjiPC samples as well as emission of luminal projection (white arrowheads), whereas EC junctions appear intact (dashed arrow). Scale bar, 1 μm (top panels) and 2 μm (bottom panel). c Quantitation of astrocyte endfeet coverage in P10 cortical blood vessels. p-values, Student’s t-test, n = 4. n.s., not statistically significant. d Confocal images of brain cortex blood vessels (tdT+, blue) showing areas of red blood cells (Ter119+, red) extravasation which are not associated to defects in astrocyte endfeet polarization (Aqp4+, white) or absence of recombined mural cells (GFP+, green). Scale bar, 50 μm. e In vivo two-photon imaging of brain blood vessels from P10 mice visualized by intravenous injection of Texas Red-dextran (white). Arrowheads (white, red, or cyan for capillaries, arteries, or veins, respectively) indicate the direction of blood flow, velocity (mm s−1) is annotated for specific vessel segments. Scale bar, 100 μm. f Quantitation of blood flow velocities of different brain vascular segments in P10 mice. p-values, one-way ANOVA with Sidak’s test, n = 3–4. n.s., not statistically significant. g Confocal images of brain cortex blood vessels stained for GLUT1 (red), PDGFRβ (white), and GFP (green) in P10 mice. Note that despite of vessel defects in the knockout animals, mural cell coverage is not affected. Scale bar, 100 μm. h Quantitation of mural cell coverage in cortical vasculature at P10. p-values, Welch’s t-test, n = 4. n.s., not statistically significant. Error bars represent s.e.m. Source data are provided as a Source Data file
