Figure 6: Vessel regression in Wt1 KO animals.
From: The Wilms’ tumour suppressor Wt1 is a major regulator of tumour angiogenesis and progression
(a) Time-dependent reduction in vessel patency and vascular density upon Tie2-Cre-mediated knockout of Wt1 (controls, n=6; Wt1 KO, n=5). Lectin staining matches Pecam-1 immunoreactivity in control animals (upper panel). Nine days after tamoxifen administration, lectin is largely reduced (arrows) indicating loss of vessel patency (middle panel). Eighteen days after tamoxifen treatment, also Pecam-1 immunoreactivity is diminished in Wt1 KO mice indicating vascular regression. Bar graphs show area density of Pecam-1 and lectin signals (right panel). (b) Collagen IV/Pecam-1 double-labelling shows a regular architecture of endothelial cells and basement membranes in control animals (upper panel, n=6), but remaining of only some membrane ghosts 18 days after tamoxifen treatment in Wt1 KO mice (lower panel, n=5). Quantification of area density of Pecam-1 and collagen IV signals is shown (right panel). (c) Pecam-1/desmin double-labelling shows close proximity between endothelial cells and pericytes in control animals (upper panel, n=6), but clear reduction of both signals and some remaining scattered pericytes (arrows) in Wt1 KO mice (lower panel, n=5). Quantification of area density of Pecam-1 and desmin is depicted in the bar graphs (right panel). Scale bars, 50 μm. Data are the mean±s.e.m. *P<0.05, **P<0.01, ***P<0.001.
