Figure 1
Selective ablation of Tgfbr2 gene expression in embryonic neuroepithelial cells does not lead to brain vascular pathologies. (a, b) Images of E12.5 control (a) and Nestin-Cre(+);Tgfbr2f/f mutant (b) embryos reveal a lack of brain vascular pathologies in the absence of TGF-β receptor signaling in the neuroepithelium. In contrast, E12.5 Nestin-Cre(+);Itgavf/f embryo (c) display intracerebral hemorrhages in the forebrain area (arrow). (d) Genomic DNA isolated from primary neonatal astrocytes was amplified with primers to monitor the presence of the Cre transgene (lower panel) or Cre-mediated deletion of the Tgfbr2-flox allele (top panel). The genotypes of the cells are listed above the top panel. (e) Control and mutant primary astrocytes were stimulated with TGF-β1 for 0, 30, and 60 min. Detergent-soluble cell lysates were immunoblotted with anti-phospho-SMAD2 or anti-actin antibodies. Note the TGF-β-dependent phosphorylation of SMAD2 in control cells, whereas there is no pSMAD2 detected in mutant cell lysates. (f, g) Primary astrocytes isolated from control (f) and mutant (g) P0 pups were stimulated with TGF-β1 for 0, 30, and 60 min. Cells were then immunofluorescently labeled with an anti-SMAD2/3 antibody. Note the TGF-β-mediated accumulation of SMAD2/3 protein in the nuclei of control cells, whereas no SMAD2/3 nuclear accumulation is detected in mutant cells.
