Amentoflavone inhibits M1 polarization of THP-1-derived foam cells by activating PPAR-α/γ

Abstract

To investigate the mechanism by which amentoflavone inhibits polarization of THP-1-derived foam cells to M1 phenotype. Human monocyte cell line THP-1 was stimulated to differentiate into M1-type macrophages using phorbol 12-myrislate13-acetate (PMA) combined with lipopolysaccharide (LPS) and recombinant human interferon-γ (rhlFN-γ). M1 polarization of THP-1-derived macrophages was confirmed by observing morphological changes of the cells and detecting the mRNA expression of L-6 and TNF-α with RT-qPCR. THP-1-derived foam cells treated with 5 or 10 μmol/L amentoflavone for 24 h were examined for cytokines using ELISA. The mRNA and protein expressions of IL-6, IL-10, TNF-α, TGF-β, PPAR-α/γ, Arg-1 and Fizz1 in the cells were detected using RT-qPCR and Western blotting. Amentoflavone prevented induced M1 polarization of THP-1 cells. Amentoflavone down-regulated the mRNA expressions of IL-6 and TNF-α, up-regulated mRNA expressions of IL-8 and TGF-β mRNA (P < 0.05), and increased the protein expressions of PPAR-α/γ, Arg-1 and Fizz1. Molecular docking simulation showed that amentoflavone could bind to the surface of PPARα/γ. Amentoflavone can inhibit the differentiation of macrophages into M1 type by activating PPAR-α/γ and restoring the expressions of the gene Arg-1 and Fizz1.