Actively translating transcriptome (Ribotag) profiling of mouse retinal endothelial cells during postnatal development

Angiogenesis, a process mediating the expansion of vascular beds in many physiological and pathological settings, requires dynamic changes in endothelial cell (EC) behavior. The molecular mechanisms governing EC activity during different phases of vascular growth, remodeling, maturation, and quiescence remain elusive. Here, we have employed actively translating transcriptome analysis of mouse retinal ECs for the characterization of dynamic gene expression changes during postnatal development and the identification of critical angiogenic factors. In silico computational analyses of these data enabled the identification of candidate regulators controlling EC behavior at different developmental checkpoints. The detailed characterization of Mafb, one of the identified candidates, established that this transcription factor controls endothelial sprouting in vitro and in vivo. Integrative analysis of RNA-Seq and ChIP-Seq data defined putative direct Mafb targets, which are repressed or activated by the transcriptional regulator. Together, our results identify novel cell-autonomous regulatory mechanisms controlling sprouting angiogenesis. Overall design: 2 retinas from a mouse were used for single library / 3 biological replicates (individual mouse) per sample / 5 developmental stages of P6, P10, P15, P21 and P50 / EC-specific Mafb conditional KO