Pro-angiogenic transcriptome of zebrafish endothelial cells

To identify previously unknown determinants of endothelial cell sprouting, we defined and exploited a pharmacological strategy for the manipulation of angiogenic cell behavior in vivo. Whereas high vascular endothelial growth factor receptor (Vegfr) signaling is known to promote tip cell (TC) specification, activation of the Notch receptor via its ligand Delta-like 4 (Dll4) represses the TC phenotype to promote stalk cell (SC) fate. Conversely, suppression of Notch activity upon antagonistic interaction with its ligand Jagged1 pro- motes TC formation. Hence, specification of TCs involves tight spatiotemporal control of Vegfr/Notch signaling. Consequently, we hypothesized that the pharmacological manipulation of Vegfr/Notch signaling selectively during zebrafish intersegmental vessel (ISV) angiogenesis would enable the precise control of angiogenic EC behavior and sprouting- associated gene expression in vivo. For more information, see Herbert et al., 2012, PMID 22921365. Zebrafish embryos were treated with DMSO (Control), DAPT (hypersprouting condition), SU5416(inhibition of sprouting) or both from 22hpf to 30hpf.At 30hpf, cells were dissociated and endothelial cells were isiolated for further RNA extraction