Genetic dissection of the impact of lncRNA AI662270 during the development of atherosclerosis

BackgroundAtherosclerosis is driven by synergistic interactions between pathological biomechanical and lipid metabolic factors. Long noncoding RNAs (LncRNAs) have been implicated in atherogenesis. The purpose of this study was to investigate the potential mechanism of lncRNA AI662270 on macrophage cholesterol transport in atherosclerosis.MethodsApolipoprotein E deficiency (ApoE(-/-)) mice were fed a high fat diet for 16 weeks to construct atherosclerotic model, and the mice were injected with recombinant lentivirus carrying AI662270 gene to overexpress AI662270. Macrophages were cleared by liposomal clondronate in vivo. Fundamental experiments and functional assays, hematoxylin and eosin staining, oil red O staining and others, were performed to evaluate the function of AI662270 on atherogenesis. Peritoneal macrophages were treated with oxidized low density lipoprotein (ox-LDL) to simulate in vitro model. Mechanism assays, RNA-interacting protein immunoprecipitation, RNA-protein pulldown and others, were performed to study the regulatory mechanism of AI662270 in macrophages.ResultsThe novel AI662270 was mainly enriched in macrophages, but not in endothelial cells, smooth muscle cells and fibroblasts of mouse atherosclerotic lesions and was upregulated by ox-LDL. Overexpression of AI662270 resulted in lipid accumulation, larger atherosclerotic plaques and cardiac dysfunction in vivo. After macrophages were removed, the pro-atherogenic effect of AI662270 disappeared. Downregulation of AI662270 in macrophages protected against foam cell formation by potentiating cholesterol efflux and reducing intracellular total cholesterol. The opposite effect was observed in macrophage-specific AI662270-overexpressed cells in vitro. AI662270 bound to adenosine triphosphate-binding cassette transporter A1 (Abca1) responsible for regulating cholesterol efflux in macrophages. Forced expression of AI662270 in macrophages decreased Abca1 expression. The reverse occurred when expression of AI662270 was repressed.ConclusionThese findings reveal an essential role for AI662270 in atherosclerosis progression by regulating cholesterol efflux from macrophages.

Automated summary

This study investigates the potential mechanism of lncRNA AI662270 on macrophage cholesterol transport in atherosclerosis. It is found that overexpression of AI662270 leads to lipid accumulation, larger atherosclerotic plaques, and cardiac dysfunction. Mechanism assays reveal that AI662270 regulates cholesterol efflux from macrophages, playing a crucial role in atherosclerosis progression.