Role of miR‐15a‐5p and miR‐199a‐3p in the inflammatory pathway regulated by NF‐κB in experimental and human atherosclerosis

Abstract

Background: Cardiovascular diseases (CVDs) prevalence has significantlyincreased in the last decade and atherosclerosis development is the main trig-ger. MicroRNAs (miRNAs) are non-coding RNAs that negatively regulate geneexpression of their target and their levels are frequently altered in CVDs. Methods: By RT-qPCR, we analysed miR-9-5p, miR-15a-5p, miR-16-5p andmiR-199a-3p levels in aorta from apolipoprotein knockout (ApoE−/−) mice, anexperimental model of hyperlipidemia-induced atherosclerosis, and in humanaortic and carotid atherosclerotic samples. By in silico studies, Western blotanalysis and immunofluorescence studies, we detected the targets of the alteredmiRNAs. Results: Our results show that miR-15a-5p and miR-199a-3p are significantlydecreased in carotid and aortic samples from patients and mice with atheroscle-rosis. In addition, we found an increased expression in targets of both miRNAsthat participate in the inflammatory pathway of nuclear factor kappa B (NF-κB), such as IKKα,IKKβand p65. In human vein endothelial cells (HUVECs)and vascular smooth muscle cells (VSMCs), the overexpression of miR-15a-5p ormiR-199a-3p decreased IKKα,IKKβand p65 protein levels as well as NF-κB acti-vation. On the other hand, miR-15a-5p and miR-199a-3p overexpression reducedox-LDL uptake and the inflammation regulated by NF-κB in VSMCs. Moreover,although miR-15a-5p and miR-199a-3p were significantly increased in exosomes from patients with advanced carotid atherosclerosis, only in the ROC analysesfor miR-15a-5p, the area under the curve was 0.8951 with apvalue of .0028. Conclusions: Our results suggest that the decrease of miR-199a-3p and miR-15a-5p in vascular samples from human and experimental atherosclerosis could beinvolvedintheNF-κBactivationpathway,aswellasinox-LDLuptakebyVSMCs,contributing to inflammation and progression atherosclerosis. Finally, miR-15a-5p could be used as a novel diagnostic biomarker for advanced atherosclerosis.