Cholesteryl Ester Accumulation in Macrophages Treated with Oxidized Low Density Lipoprotein

Abstract

The ability of CuSO₄- and hypochlorite-oxidized LDL to promote cholesterol accumulation in macrophages was examined. Both CuSO₄- and hypochlorite-oxidized LDL were rapidly metabolized by mouse peritoneal macrophages to a level approximately 10 times that observed for native LDL and both modified lipoproteins increased the accumulation of unesterified cholesterol. However when each modified lipoprotein was incubated with macrophages for 40 h, only hypochlorite-oxidized LDL produced significant accumulation of cholesteryl esters, with levels approaching 85 μg/mg cell protein. This finding was verified by nile red staining. The cholesteryl ester content of cupric sulfate-modified LDL was found to be significantly decreased when compared to either native or hypochlorite-modified LDL promotes massive cholesteryl ester accumulation because the cholesteryl ester content of the LDL particle is preserved.