Differential ability of cells to promote oxidation of low density lipoproteins in vitro.

Atherosclerosis and focal segmental glomerulosclerosis share some common histological features and it is speculated that they result from similar pathobiological mechanisms. There is strong evidence that oxidation of low density lipoprotein (LDL) may be an initiating event in atherogenesis and that oxidised LDL may also be involved in the glomerulosclerotic process. In vitro studies have demonstrated that cells present in the arterial intima and kidney-derived cells promote LDL oxidation. The aim of this study was to compare LDL oxidation by kidney-derived human mesangial cells and proximal tubular cells, with human umbilical vein endothelial cells and the human monocyte cell line THP-1. We used the thiobarbituric acid assay and agarose gel electrophoresis to measure the extent of LDL oxidation. Our results demonstrate that all of the cell types used had the ability to oxidise LDL significantly more than cell-free controls and that endothelial cells induced the highest degree of oxidative modification of LDL under our experimental conditions.