Atherosclerosis (AS) is a cardiovascular disorder accompanied by endothelial dysfunction. Extensive evidence demonstrates the regulatory functions of long noncoding RNAs (lncRNAs) in cardiovascular disease, including AS. Here, the function of lncRNA small nucleolar RNA host gene 12 (SNHG12) in AS progression was investigated. A cell model of AS was established in human umbilical endothelial cells (HUVECs) using oxidative low-density lipoprotein (ox-LDL). CCK-8, flow cytometry, TUNEL, ELISA, and western blotting analyses were performed. Apolipoprotein E-deficient (apoE-/-) mice fed a Western diet were used as in vivo models of AS. RT-qPCR determined the levels of SNHG12, microRNA-218-5p (miR-218-5p) and insulin-like growth factor-II (IGF2). The molecular mechanisms were investigated using luciferase reporter and RNA pull-down assays. We found that SNHG12 and IGF2 expression levels were high and miR-218-5p expression levels were low in AS patients and ox-LDL-treated HUVECs. SNHG12 depletion attenuated ox-LDL-induced injury in HUVECs, whereas miR-218-5p suppression partially abated this effect. Moreover, IGF2 overexpression prevented the alleviative role of miR-218-5p in ox-LDL-treated HUVECs. SNHG12 upregulated IGF2 expression by sponging miR-218-5p. More importantly, SNHG12 increased proinflammatory cytokine production and augmented atherosclerotic lesions in vivo. Overall, SNHG12 promotes the development of AS by the miR-218-5p/IGF2 axis.
Keywords: Atherosclerosis; HUVECs; IGF2; SNHG12; miR-218-5p; ox-LDL.