Abstract:Aim To observe the targeting regulation of miR-497-5p on nucleotide-binding oligomerization domain-like receptor protein 1 (NLRP1) and its effect on cholesterol efflux. Methods Bioinformatics and luciferase reporter gene assay were used to verify the targeted binding of miR-497-5p and NLRP1. Human THP-1 monocytes were induced into foam cells after treatment with phorbol ester and oxidized low density lipoprotein. miR-497-5p mimic and miR-497-5p inhibitor were used to treat cells. Real-time fluorescence quantitative PCR and Western blot were used to detect the expressions of NLRP1, cysteinyl aspartate specific proteinase 1 (Caspase-1) and apoptosis-associated speck-like protein containing a Caspase-recruitment domain (ASC). The contents of interleukin-1β (IL-1β) and IL-18 in cell culture medium were determined by enzyme-linked immunosorbent assay. Cholesterol efflux detection was performed by liquid scintillator. Lipid content in foam cells was detected by high performance liquid chromatography. Results The luciferase activity of wild type NLRP1 3′UTR reporter gene was significantly reduced by miR-497-5p mimic. Compared with the control group, the mRNA and protein expression levels of NLRP1, ASC and Caspase-1 in miR-497-5p mimic group were significantly down regulated, and the secretions of IL-1β and IL-18 was significantly reduced. Compared with the control group, miR-497-5p mimic significantly promoted the cellular cholesterol efflux and reduced the contents of total cholesterol, free cholesterol and cholesterol ester in cells. Conclusion miR-497-5p may inhibit the inflammatory response of macrophage-derived foam cells and promote cholesterol efflux by targeting regulation of NLRP1.