Identification and Initial Functional Characterization of SENCR, a Long Non-Coding RNA Enriched in Human Vascular Cells

RNA sequencing (RNA-seq) analysis revealed 31 novel lncRNAs in HCASMC, including a vascular cell-enriched lncRNA called SENCR (for Smooth muscle and Endothelial cell long Non-Coding RNA). RT-PCR and hybridization studies show SENCR exists in two isoforms and is transcribed antisense from the 5’ end of the FLI1 gene. Knockdown of SENCR has no effect on FLI1 mRNA or protein expression. Biochemical fractionation and RNA fluorescence in situ hybridization (FISH) studies indicate SENCR is a cytoplasmic lncRNA. RNA-seq experiments in HCASMC where SENCR is attenuated disclose decreased expression of Myocardin and many SMC contractile genes; conversely a pro-migratory gene signature is increased. RT-PCR and Western blotting validated several differentially expressed genes following SENCR knockdown. Loss-of-function studies in scratch wound and Boyden chamber assays support SENCR as an inhibitor of vascular cell migration. Total RNAs of 3 replicates of normal human coronary artery smooth muscle cells (Mock1, Mock2 and Mock3) were sequenced and analyzed for identification of novel lncRNAs. One of identified novel lncRNAs from that experiment is SENCR. To study its function, SENCR knock-down experiment were performed and then RNA-seq profiles of 3 replicates of both SENCR-knockdown samples and corresponding controls were compared.