Gene Expression Profile Signatures Indicate a Role for Wnt Signaling in Endothelial Commitment From Embryonic Stem Cells

Abstract
We have used global gene expression analysis to establish a comprehensive list of candidate genes in the developing vasculature during embryonic (ES) cell differentiation in vitro. A large set of genes, including growth factors, cell surface molecules, transcriptional factors, and members of several signal transduction pathways that are known to be involved in vasculogenesis or angiogenesis, were found to have expression patterns as expected. Some unknown or functionally uncharacterized genes were differentially regulated in flk1+ cells compared with flk1− cells, suggesting possible roles for these genes in vascular commitment. Particularly, multiple components of the Wnt signaling pathway were differentially regulated in flk1+ cells, including Wnt proteins, their receptors, downstream transcriptional factors, and other components belonging to this pathway. Activation of the Wnt signal was able to expand vascular progenitor populations whereas suppression of Wnt activity reduced flk1+ populations. Suppres...