Vascular endothelial cells (ECs) line the interior of blood vessels and respond to inflammation through a series of well-characterized chemokines and receptors. Less is known about the cis-regulatory elements (CREs) that control the endothelial inflammatory response in humans and other mammals. The NF-kappaB complex, in particular its subunit RELA (p65), is an essential inflammatory mediator in ECs. To study the evolution and function of endothelial acute inflammatory response, we characterized RELA binding sites and epigenetic changes that occur after TNF-alpha treatment in primary aortic ECs isolated from human, mouse, and cow. We discovered ~5000 RELA binding sites at orthologous regions in all three species near genes involved in vascular development and pro-inflammatory responses. The conserved RELA binding sites were enriched for known regulatory disease mutations. We established a CRISPR/Cas9 gene editing approach in an immortalized human aortic EC line and used this platform to study the function of TNF-alpha-induced CREs. |