Quercetin Suppresses the Progression of Atherosclerosis by Regulating MST1-Mediated Autophagy in ox-LDL-Induced RAW264.7 Macrophage Foam Cells

• Published in: International journal of molecular sciences Vol. 20; no. 23; p. 6093
• Main Authors: Cao, Hui, Jia, Qingling, Yan, Li, Chen, Chuan, Xing, Sanli, Shen, Dingzhu
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.12.2019; MDPI
• Subjects: Accumulation; Adenine - analogs & derivatives; Adenine - pharmacology; Aging; Animals; Apoptosis; Arteriosclerosis; Atherosclerosis; Atherosclerosis - pathology; Autophagy; Autophagy - drug effects; Bcl-2 protein; Cell Survival - drug effects; Cell viability; Cellular Senescence - drug effects; Cholecystokinin; Cyclin-Dependent Kinase Inhibitor p16 - metabolism; Cyclin-dependent kinase inhibitor p21; Cyclin-Dependent Kinase Inhibitor p21 - metabolism; Cyclin-dependent kinases; Disease Progression; Foam Cells - drug effects; Foam Cells - metabolism; Foam Cells - pathology; Galactosidase; Hepatocyte Growth Factor - metabolism; Immunofluorescence; In vitro methods and tests; Kinases; Lipid Metabolism - drug effects; Lipids; Lipoproteins, LDL - pharmacology; Low density lipoprotein; Macrophages; Metabolism; Mice; Mitochondria; Oxidative stress; Phagocytosis; Phagosomes; Phenotypes; Proteins; Proto-Oncogene Proteins - metabolism; Quercetin; Quercetin - pharmacology; Rapamycin; RAW 264.7 Cells; Senescence; Sirolimus - pharmacology; Staining; Survival; Up-Regulation - drug effects; β-Galactosidase; atherosclerosis; senescence; quercetin; autophagy; RAW264.7
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20236093

To investigate the process by which quercetin suppresses atherosclerosis by upregulating MST1-mediated autophagy in RAW264.7 macrophages. An in vitro foam cell model was established by culturing RAW264.7 macrophages with oxidized low-density lipoprotein (ox-LDL). The cells were treated with quercetin alone or in combination with the autophagy inhibitor, 3-methyladenine, and autophagy agonist, rapamycin. Cell viability was detected with a CCK-8 kit. Lipid accumulation was detected by oil red O staining, senescence was detected by SA-β-gal (senescence-associated β-galactosidase) staining, reactive oxygen species were detected by ROS assay kit. Autophagosomes and mitochondria were detected by transmission electron microscope (TEM), and expression of MST1, LC3-II/I, Beclin1, Bcl-2, P21, and P16 were detected by immunofluorescence and Western blot. Ox-LDL induced RAW264.7 macrophage-derived foam cell formation, reduced survival, aggravated cell lipid accumulation, and induced a senescence phenotype. This was accompanied by decreased formation of autophagosome; increased expression of P53, P21, and P16; and decreased expression of LC3-II/I and Beclin1. After intervention with quercetin, the cell survival rate was increased, and lipid accumulation and senescence phenotype were reduced. Furthermore, the expression of LC3-II/I and Beclin1 were increased, which was consistent with the ability of quercetin to promote autophagy. Ox-LDL also increased the expression of MST1, and this increase was blocked by quercetin, which provided a potential mechanism by which quercetin may protect foam cells against age-related detrimental effects. Quercetin can inhibit the formation of foam cells induced by ox-LDL and delay senescence. The mechanism may be related to the regulation of MST1-mediated autophagy of RAW264.7 cells.