Abstract 1666 long non-coding RNA-regulated endothelial stress response (in diabetes)

Lining the critical interface between circulating blood and vascular wall, endothelial cells (ECs) play vital functions in health and disease. The optimal gene expression in ECs is essential to maintain endothelial homeostasis, and its dysregulation can lead to EC dysfunction, a common mechanism underlying many metabolic and cardiovascular diseases, e.g. diabetes and diabetes-associated vasculopathy. In this work, we aim to identify the role of long non-coding RNAs in the regulation of endothelial gene expression and function in the context of diabetes. We used RNA-seq to profile lncRNAs in human endothelial cells responding to hypoxia, high glucose, and TNFa, which was combined with scRNA-seq to profile transcriptome in human mesenteric arteries. We identified LINC00520 to be an enhancer-derived lncRNA that enhances endothelial nitric oxide synthase (eNOS) expression, aka LEENE in ECs. LEENE is suppressed in diabetes conditions in ECs in vitro, in vivo, and in human arteries. Knockout of leene homologue in mouse resulted in impaired microvascular function, evident in a diabetic hindlimb ischemia model. Overexpression of human LEENE RNA in the knockout mice rescued the ischemic recovery, resembling that of wildtype animals at tissue function and transcriptome, and single cell gene expression levels. Mechanistically, LEENE binds to LEO1 protein and the promoters of a set of pro-angiogenic genes to induce their transcription, as revealed by chromatin isolation with RNA pulldown assays. Taken together, our work demonstrates an essential role for LEENE in the regulation of tissue perfusion and regeneration. Additionally, we mapped genome-wide chromatin-associated RNAs in EC undergoing diabetes-mimicking stress conditions and identified new lncRNA candidates for further studies. Collectively, our studies identify novel role of lncRNAs in endothelial stress response and suggest the targeting of select lncRNAs as a potential strategy to tackle diabetes-associated vascular diseases such as peripheral arterial disease. NIH R01HL145170 R01HL106089 Ella Fitzgerald Foundation