Qin Li, Qin Xu-Ping, Wang Zuo, Zhu Bing-Yang, Liao Duan-Fang
Institute of Pharmacy and Pharmacology, Nanhua University, Hengyang 421001, China.
Sheng Li Xue Bao. 2006 Feb 25;58(1):47-52.
The purpose of the present study was to investigate the effect of pravastatin on cholesteryl esters in foam cells of murine macrophages and the relation with caveolin-1. RAW 264.7 murine macrophages were coincubated with 80 mg/L oxidized low density lipoprotein (ox-LDL) and pravastatin (0100 mumol/L) respectively for 24 h. When the best control concentration of pravastatin was confirmed, RAW 264.7 murine macrophages were coincubated with 80 mg/L ox-LDL and pravastatin of the best concentration respectively for 0, 6, 12, 24 h. Oil red O dyeing experiment was used to show the lipid droplets in foam cells. High performance liquid chromatography (HPLC) analysis was performed to determine the content of cellular cholesterol. The level of caveolin-1 was determined by Western blot analysis. The result showed that when macrophages were incubated with 80 mg/L ox-LDL, the ratio of cellular cholesteryl ester to total cholesterol (CE/TC) was beyond 50% through HPLC analysis, and a great deal of lipid droplets displayed in cells through Oil red O dyeing experiment, which manifested the formation of the foam cells. Pravastatin could decrease CE in foam cells in a concentration-dependent manner (1100 mumol/L). At the concentration of 100 mumol/L, pravastatin decreased cellular CE more than 50%. The effects of pravastatin on the decrease of CE in murine macrophages also displayed a time-dependent manner (incubated with 100 mumol/L pravastatin from 6 to 24 h). Moreover, the expression of caveolin-1 was decreased when the macrophages were incubated with ox-LDL (80 mg/L), while treatment with pravastatin increased the level of caveolin-1 and displayed a concentration- and time-dependent manner. These results suggest that pravastatin could inhibit the development of foam cells through the decrease of cellular CE, which may be related to the upregulation of caveolin-1.
本研究旨在探讨普伐他汀对小鼠巨噬细胞泡沫细胞中胆固醇酯的影响及其与小窝蛋白-1的关系。将RAW 264.7小鼠巨噬细胞分别与80 mg/L氧化低密度脂蛋白（ox-LDL）和普伐他汀（0100 μmol/L）共孵育24小时。确定普伐他汀的最佳对照浓度后，将RAW 264.7小鼠巨噬细胞分别与80 mg/L ox-LDL和最佳浓度的普伐他汀共孵育0、6、12、24小时。采用油红O染色实验显示泡沫细胞中的脂滴。进行高效液相色谱（HPLC）分析以测定细胞胆固醇含量。通过蛋白质免疫印迹分析测定小窝蛋白-1的水平。结果显示，当巨噬细胞与80 mg/L ox-LDL孵育时，通过HPLC分析细胞胆固醇酯与总胆固醇的比值（CE/TC）超过50%，并且通过油红O染色实验在细胞中显示出大量脂滴，这表明泡沫细胞的形成。普伐他汀可呈浓度依赖性（1100 μmol/L）降低泡沫细胞中的CE。在100 μmol/L浓度下，普伐他汀使细胞CE降低超过50%。普伐他汀对小鼠巨噬细胞中CE降低的作用也呈时间依赖性（与100 μmol/L普伐他汀共孵育6至24小时）。此外，当巨噬细胞与ox-LDL（80 mg/L）孵育时，小窝蛋白-1的表达降低，而用普伐他汀处理可增加小窝蛋白-1的水平，并呈浓度和时间依赖性。这些结果表明，普伐他汀可通过降低细胞CE来抑制泡沫细胞的形成，这可能与小窝蛋白-1的上调有关。
