Abstract

Elevated amounts of cholesterol are thought to be involved in several severe diseases. Despite the fact that many studies have been performed and published, the action of cholesterol-lowering agents used to diminish the plasma cholesterol level is not fully understood yet. In this study, the effects of the HMG-CoA reductase inhibitor rosuvastatin and the new CYP51A1 inhibitor 2-((3,4-dichlorophenethyl)(propyl)amino)-1-(pyridin-3-yl)ethanol (LEK-935) on the proteome of primary human hepatocytes were analyzed for the first time. To get an idea about interindividual differences, two different human donors were used. The cytosolic and microsomal fractions of the cells were analyzed in a semiquantitative manner by two-dimensional-polyacrylamide gel electrophoresis and capillary high-performance liquid chromatography-mass spectrometry, respectively. Thereby, a set of 44 proteins was found to be differentially presented. The chosen experimental set-up was validated by proteins already known to be affected by statins and involved in the cholesterol biosynthesis. Other proteins found to be regulated cannot be directly related to cholesterol metabolism and have not been described to be affected by cholesterol-lowering agents so far. Some of these proteins may represent interesting targets for further investigations into the analysis of severe side-effects as well as pleiotropic effects of the statins. During the proteome analysis of the two different donors, interindividual differences were observed that were validated by real-time reverse transcription-polymerase chain reaction measurements. Thus, new information and a deeper insight into the processes taking place inside cells treated with cholesterol-lowering agents can be drawn from this study.