LncEGFL7OS Regulates Human Angiogenesis by Interacting with MAX at the EGFL7/miR-126 locus

In an effort to identify human endothelial cell (EC)-enriched lncRNAs,~500 lncRNAswere shown to be highly restricted in primary human ECs. Among them,lncEGFL7OS, located inthe opposite strand of theEGFL7/miR-126gene, is regulated by ETS factors through abidirectional promoter in ECs. It is enriched in highly vascularized human tissues, and upregulatedin the hearts of dilated cardiomyopathy patients. LncEGFL7OS silencing impairs angiogenesis asshown by EC/fibroblast co-culture, in vitro/in vivo and ex vivo human choroid sproutingangiogenesis assays, while lncEGFL7OS overexpression has the opposite function. Mechanistically,lncEGFL7OS is required for MAPK and AKT pathway activation by regulating EGFL7/miR-126expression. MAX protein was identified as a lncEGFL7OS-interacting protein that functions toregulate histone acetylation in the EGFL7/miR-126 promoter/enhancer. CRISPR-mediated targetingof EGLF7/miR-126/lncEGFL7OS locus inhibits angiogenesis, inciting therapeutic potentialargeting this locus. Our study establishes lncEGFL7OS as a human/primate-specific EC-restricted lncRNA critical for human angiogenesis