Long noncoding RNAs C2dat1 enhances vascular smooth muscle cell proliferation and migration by targeting MiR-34a-5p

Deregulated proliferation of vascular smooth muscle cells (VSMCs) is one common phenomenon of atherosclerosis progression. Long noncoding RNAs (lncRNAs) are one group of noncoding RNAs that play essential roles in many cell biological processes, including cell development, growth, and migration. However, the role of a novel calcium/calmodulin-dependent protein kinase type II subunit delta (CAMK2D)-associated lncRNA, CAMK2D-associated transcript 1 (C2dat1), in VSMCs is still uncovered. In this study, we showed that the expression level of C2dat1 was higher in coronary artery disease (CAD) tissues than in normal arterial tissues and the C2dat1 expression level was upregulated in the proliferating VSMC after being treated with PDGF-bb or TNF-α. In addition, we indicated that overexpression of C2dat1 promoted VSMC growth and enhanced proliferating cell nuclear antigen (PCNA) expression in VSMC. Moreover, ectopic expression of C2dat1 increased VSMC migration. Furthermore, we showed that elevated expression of C2dat1 suppressed microRNA-34a (miR-34a) expression and promoted sirtuin 1 (SIRT1) expression, which was a direct target gene of miR-34a. We demonstrated that the expression level of miR-34a was lower in CAD tissues than in normal arterial tissues and the expression of miR-34a was negatively correlated with C2dat1 expression. Restored expression of C2dat1 increased VSMC proliferation and migration through promoting SIRT1 expression. These data suggested that lncRNA C2dat1 might be a potential therapeutic target to promote VSMC growth and migration in CAD.