Article ID Journal Published Year Pages File Type
1949394 Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 2012 8 Pages PDF
Abstract

Large numbers of monocytes are recruited in the infarcted myocardium. Their cell membranes contain cholesterol-rich microdomains called lipids rafts, which participate in numerous signaling cascades. In addition to its cholesterol-lowering effect, pravastatin has several pleiotropic effects and is widely used as secondary prevention treatment after myocardial infarction (MI). The aim of this study was to investigate the effects of pravastatin on the organization of cholesterol within monocyte membrane rafts from patients who had suffered myocardial infarction. Monocytes from healthy donors and acute MI patients were cultured with or without 4 μM pravastatin. Lipid rafts were extracted by Lubrol WX, caveolae and flat rafts were separated using a modified sucrose gradient. Cholesterol level and caveolin-1 expression in lipid rafts were determined. In healthy donors, cholesterol was concentrated in flat rafts (63 ± 3 vs 13 ± 1%, p < 0.001). While monocytes from MI patients presented similar cholesterol distribution in both caveolae and flat rafts. Cholesterol distribution was higher in flat rafts in healthy donors, compared to MI patients (63 ± 3 vs 41 ± 2%, p < 0.001), with less distribution in caveolae (13 ± 1 vs 34 ± 2%, p < 0.001). Pravastatin reversed the cholesterol distribution in MI patients cells between flat rafts (41 ± 2 vs 66 ± 3%, p < 0.001) and caveolae (34 ± 2 vs 18 ± 1%, p < 0.001). In conclusion, MI redistributes cholesterol from flat rafts to caveolae indicating monocyte membrane reorganization. In vitro pravastatin treatment restored basal conditions in MI monocytes, suggesting another effect of statins.

► Description of a new methodology to separate membrane lipid microdomains. ► Applying this methodology to monocytes from healthy and myocardial infarction patients. ► Analyzing the differences in membrane reorganization between these groups. ► Myocardial infarction redistributes cholesterol to caveolae. ► Pravastatin restored original conditions.

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