Effects of Copper-Zinc Type Superoxide Dismutase on the Proliferation and Migration of Cultured Vascular Smooth Muscle Cells Induced by Oxidized Low Density Lipoprotein

Abstract

We have investigated the effects of copper-zinc type superoxide dismutase (Cu, Zn-SOD) on the function of oxidized low density lipoprotein, utilizing cultured smooth muscle cells (SMC), obtained from rabbit aorta. We added native LDL (nLDL), minimally oxidized LDL (MmLDL) and copper ion-induced oxidized LDL (OxLDL) to the culture media. No remarkable change was found out by adding nLDL. The numbers of SMC, including migrated SMC, were increased by the addition of MmLDL. Cu, Zn-SOD significantly inhibited the reactions induced by MmLDL. The SMC numbers were markedly decreased by OxLDL addition without recovery by adding Cu, Zn-SOD. Thus, MmLDL significantly promoted the SMC proliferation and migration. OxLDL revealed strong cytotoxicity against SMC. Cu, Zn-SOD inhibited both the migration and the proliferation of SMC induced by MmLDL, and did not alter the effect of OxLDL. In conclusion, Cu, Zn-SOD inhibited some functions of MmLDL, and may play an important role in protecting against the atherosclerotic processes evoked by MmLDL.