Effect of Oxidized Low Density Lipoprotein on the Production of Interleukin-18 in and the Proliferation of Cultured Human Umbilical Vein Endothelial Cells

Objective To investigate the effects of oxidized low density lipoprotein(ox-LDL) on the production of interleukin-18(IL18) and the proliferation in cultured human umbilical vein endothelial cells(HUVECs).Methods Cultured HUVECs at passage 3 to 6 were used for experiment.There were control group and ox-LDL groups with different concentration.HUVECs were incubated with different concentration(10,20,50,100,200 mg/L) of ox-LDL for different periods(12,24,36,48h).IL18 in supernatant medium was detected by cell ELISA and cell proliferation was measured by MTT colorimetric assay.Results Ox-LDL(10 mg/L) could enhance the proliferation of HUVECs,but ox-LDL(20~200 mg/L) could inhibit it in a dose-dependent manner(P0.05,P0.01).HUVECs didn't release IL18 without stimulation.The production of IL18 activated by Ox-LDL in HUVECs remarkably increased in a dose-dependent manner.Maximal levels of IL18 occurred at 100mg/L of LDL.The enhancing effect was also time-dependent.Compared with 12h,the levels of IL18 were significantly increased at 24,36,48 h of stimulation with Ox-LDL(P0.05,P0.01).Conclusion ox-LDL could obviously stimulate the production of IL18 in HUVECs and inhibit the proliferation of HUVECs,which may thereby influence the pathogenesis of atherosclerosis.