Cell-by-cell analysis of VEGFR1 and VEGFR2 distribution on ex vivo and in vitro cells.

<p>(A) Human and mouse endothelial cells display similar distributions of VEGFR1, the magnified traces show the distributions at the range encompassing a majority of the endothelial cells expressing VEGFR1, and it shows that the histograms overlap considerably, while the higher-VEGFR1-expressing fibroblasts have a much broader distribution of VEGFR1. (B) The histograms representing VEGFR2 levels on human in vitro endothelial cells, mouse ex vivo endothelial cells, and mouse in vitro fibroblasts have distinct profiles. The mouse endothelial cells have a large population expressing low levels of VEGFR2, and a broader range of cells expressing high levels of VEGFR2 relative to the mouse fibroblasts, which are more homogenous in their surface expression of VEGFR2. The human endothelial cells have much higher numbers of VEGFR2 on the cell surface, and the greatest heterogeneity in endothelial, VEGFR2 surface numbers.