Figure 1. Enhanced proliferation and decreased senescence of CD47-null murine endothelial cells is associated with increased expression of c-Myc.

(A) MTS assay for cell survival and growth over 72 h expressed as % of day 0 values at the indicated plating densities of first passage WT and CD47 null cells. (B) BrdU assay for DNA synthesis. (C) Percentage of senescence-associated β-galactosidase expression at passage 3. (D) Expression of genes associated with cell immortalization in WT and CD47 null cells. (E) c-Myc mRNA levels in lung endothelial cells of WT and CD47 null mice. (F) CD47 limits c-Myc protein levels. (G) c-Myc expression (red) in WT and CD47−/− endothelial cells. Blue = DAPI nuclear stain. (H) Flow cytometric analysis of c-Myc expression in WT and CD47−/− endothelial cells. (*p < 0.05, **p < 0.01).