Figure 5. C/EBP-δ is expressed in vascular endothelial cells, and regulates cell motility and angiogenesis.

Pulmonary microvascular endothelial cells were isolated from age and sex matched C/EBP-δ null mice and littermate WT mice (pooled from 5 mice per group). Expression of C/EBP-δ in endothelial cells was examined by semi quantitative RT-PCR (Panel A). Endothelial cell migration was evaluated in a Transwell assay with seeding the primary murine endothelial cells in the upper chamber and addition of recombinant VEGF protein at 20 ng/ml in the bottom chamber (Panel B). The migrated cells were counted 5 hours later (Panel C). **p < 0.01. Murine endothelial cells were seeded on the top of Matrigel and incubated for 24 hours. Vascular network formation was imaged under microscopy (Panel D). The number of cross point of vascular structures was counted in 10 randomly selected fields under microscopy (Panel E). **p < 0.01. Aortas collected from age and sex matched WT and C/EBP-δ null mice (n = 3 mice per group) were cut into small pieces, embedded in fibrin gel and overlaid with EGM. The number of vascular sprouts was imaged and counted under microscopy after one week in culture (Panel F and G). **p < 0.01, *p < 0.05. All in vitro and ex vivo data were done in triplicates and collected from three independent experiments, and expressed as mean ± SD. Representative images are shown in each study.