Radial Glial Neural Progenitors Regulate Nascent Brain Vascular Network Stabilization Via Inhibition of Wnt Signaling
(A–B′) Cortical EC proliferation at E16.5. BrdU labeling (in red) revealed increased clusters (arrowheads) of BrdU+ ECs (IB4 in green) in mutants (B and B′). (C–D′) Ki67 staining at E16.5. Increased clusters of Ki67+ ECs (in red, arrowheads) were observed in mutants (D and D′). (E–F) Glut-1 expression in ECs at E16.5. Up-regulation of Glut-1 expression (in red) was observed in mutants (F). (G–H) Expression of Wnt reporter BAT-lacZ in ECs at E16.5. X-Gal reaction revealed increased numbers of lacZ+ (in blue, arrowheads) ECs (IB4 in brown) in mutants (H). BAT-lacZ up-regulation in neural cells appears largely restricted to the intermediate zone (IZ). (I–J) Western blot analysis of Glut-1 expression at E16.5. Stronger bands were observed in mutants (I). Quantification showed a >150% increase in mutants (J) (p = 0.03, n = 3). (K–L) Quantification of EC proliferation and BAT-lacZ expression at E16.5. The density of both BrdU+ (p = 0.001; n = 4) and lacZ+ (p = 0.001; n = 3) ECs is significantly increased in mutants. Scale bar (in D): 200 µm for (A–H).