ETV2 functions as a pioneer factor to regulate and reprogram the endothelial lineage. Mus musculus

The vasculature is an essential organ for the delivery of blood and oxygen to all tissues of the body and thus relevant to. the treatment of ischemic diseases, injury-induced regeneration, and solid tumor growth. Therefore, the definition of pioneer factors and regulatory pathways that govern the specification and differentiation of endothelial progenitors will serve as a platform for targeted therapies to promote cardiovascular regeneration and treatment of solid organ tumors. Previously, we demonstrated that ETV2 was an essential transcription factor for the development of cardiac, endothelial and hematopoietic lineages. Here, we report that ETV2 functions as a novel pioneer factor that relaxes closed chromatin and regulates endothelial development. Using engineered inducible embryonic stem cell and fibroblast cell lines in combination with single cell RNA-seq, ATAC-seq and ChIP-seq techniques, we demonstrated that ETV2 was able to bind nucleosomal DNA and function as a pioneer factor independent of the cellular context. We determined that ETV2 performs a pioneering role by recruiting BRG1 to remodel chromatin around endothelial genes and help maintain an open configuration. ETV2 chromatin binding also resulted in increased H3K27ac deposition. Collectively, these results will serve as a platform for the development of therapeutic initiatives directed towards cardiovascular and oncological diseases.