MiR-30a-5p plays an important role in various cardiovascular diseases, but its effect in atherosclerosis has not been reported. Apolipoprotein E-deficient (Apo E-/-) mice were used to investigate the role of miR-30a-5p in atherosclerosis, and the underlying mechanism was investigated in vivo and in vitro. The fluorescence in situ hybridization test revealed that miR-30a-5p was expressed in Apo E-/- mice lesions. Nevertheless, in RAW264.7 macrophages, the expression of miR-30a-5p was reduced by lipopolysaccharide (LPS) or oxidized low-density lipoprotein. MiR-30a-5p-ago-treated Apo E-/- mice significantly reduced lesion areas in the aorta and aortic root, reduced levels of lipoprotein and pro-inflammatory cytokines, and increased levels of anti-inflammatory cytokines. The ratio of M1/M2 macrophages was decreased in miR-30a-5p-ago-treated Apo E-/- mice and LPS-treated RAW264.7 macrophages by the regulation of Smad-1/2 phosphorylation. MiR-30a-5p reduced lipid uptake in oxidized low-density lipoprotein-treated macrophages by regulating the expression of PPAR-γ, ABCA1, ABCG1, LDLR, and PCSK9. Ubiquitinated ligase NEDD4L was identified as a target of miR-30a-5p. Interestingly, knockdown of NEDD4L decreased the M1/M2 ratio and oxidized low-density lipoprotein uptake in macrophages by inhibiting the ubiquitination of PPAR-γ and phosphorylation of Smad-1/2 and regulating ABCA1, ABCG1, LDLR, and PCSK9. We demonstrated a novel effect and mechanism of miR-30a-5p in atherosclerosis.
Keywords: ABCA1; ABCG1; LDLR; M1/M2 polarization; NEDD4L; PCSK9; Smad-1/2/3; macrophage; miR-30a-5p; ubiquitin.
© 2021 The Author(s).