circSnd1 promotes atherosclerosis progression through the miR-485-3p/Olr1 signaling pathway

BACKGROUND: Circular RNAs (circRNAs) participate in the development of atherosclerotic cardiovascular disease. Identifying and verifying the key competing endogenous RNA (ceRNA) network related to atherosclerosis (AS) is significant for understanding the development of AS. The aim of this study was to investigate the circRNA-miRNA‒mRNA network, identify a key circRNA and explore its role in the development of atherosclerosis. METHODS: Differentially expressed mRNAs (DEMs) and circRNAs (DECs) in the AS model were obtained from datasets in the Gene Expression Omnibus (GEO) database. R software and Cytoscape software were used to construct and visualize the ceRNA network. The dual-luciferase reporter experiment and the RNA pull-down experiment were used to verify the selected ceRNA axis. siRNA targeting circRNA, miRNA mimic, miRNA inhibitor, or gene overexpression plasmid was used for in vitro functional studies. ELISA and western blotting were used to detect inflammation and lipid transport-related proteins. Furthermore, an AS mouse model was established and treated with recombinant adeno-associated viral vectors to further verify the influence of the selected ceRNA axis on the occurrence and/or development of AS. RESULTS: A total of 497 DEMs were enriched in 25 pathways, based on which the circ_0082139 (circSnd1)/miR-485-3p/Olr1 axis was selected. In vitro, the interaction among the three molecules of this axis was validated and it was found to affect inflammation and lipid transport, which were characterized by the significant change of inflammatory factors (Il-6, Il-8, Tnf-α, Mcp-1, Vcam-1, and Icam-1), and lipid transport-related genes, including Abca1, Abcg1, Ldlr, Hdlbp, Lp-pla2, and Srebp-1c. Through animal experiments, we further verified that the circSnd1/miR-485-3p/Olr1 axis regulated these molecules and participated in the formation and/or development of AS in vivo. CONCLUSIONS: The circSnd1/miR-485-3p/Olr1 axis participates in the formation and development of atherosclerosis by regulating inflammation and lipid transport.