LncRNA RP11‐301G19.1 is required for the maintenance of vascular smooth muscle cell contractile phenotype via sponging miR‐17‐5P/ATOH8 axis

Abstract Long noncoding RNAs (LncRNAs) play essential roles in regulating gene expression in various biological processes. However, the function of lncRNAs in vascular smooth muscle cell (VSMC) transformation remains to be explained. In this work, we discover that a new bone marrow protein (BMP) signaling target, lncRNA RP11‐301G19.1, is significantly induced in BMP7‐treated VSMCs through lncRNA microarray analysis. Addition of BMP signaling inhibitor LDN‐193189 attenuates the expression of ACTA2 and SM‐22α, as well as the mRNA level of RP11‐301G19.1. Furthermore, lncRNA RP11‐301G19.1 is critical to the VSMC differentiation and is directly activated by SMAD1/9. Mechanistically, knocking down of RP11‐301G19.1 leads to the decrease of ATOH8, another BMP target, while the forced expression of RP11‐301G19.1 reactivates ATOH8. In addition, miR‐17‐5p, a miRNA negatively regulated by BMP‐7, contains predicted binding sites for lncRNA RP11‐301G19.1 and ATOH8 3′UTR. Accordingly, overexpression of miR‐17‐5p decreases the levels of them. Together, our results revealed the role of lncRNA RP11‐301G19.1 as a miRNA sponge to upregulate ATOH8 in VSMC phenotype transformation.