Human umbilical vein endothelial cells (HUVECs) were provided by The Cell Bank of Type Culture Collection of The Chinese Academy of Sciences and maintained at 37˚C in a humidified incubator with 5% CO2. HUVECs were cultured in F12K medium (Boster Biological Technology Co., Ltd.) supplemented with 10% FBS (Gibco; Thermo Fisher Scientific, Inc.), 100 µg/ml streptomycin and 100 IU/ml penicillin (Boster Biological Technology Co., Ltd.). HUVECs were treated with 100 µg/ml oxidized low-density lipoprotein (ox-LDL; UnionBiol Biotechnologies Co., Ltd.) for 24 h at 37˚C to simulate atherosclerosis, as previously described (20 (link)).