亲环素A在巨噬细胞荷脂过程中的影响

目的观察胆固醇转运复合物中关键蛋白亲环素A在氧化型低密度脂蛋白诱导的巨噬细胞荷脂过程中的表达变化及其与细胞内胆固醇蓄积的关系,进而分析亲环素A在巨噬源性泡沫细胞形成过程中的作用。方法采用75 mg/L氧化型低密度脂蛋白与RAW264.7细胞共同孵育,建立巨噬细胞荷脂化模型;Western-blot、免疫荧光法检测亲环素A蛋白的表达水平;高效液相色谱法检测细胞内胆固醇含量的变化。结果75 mg/L氧化型低密度脂蛋白与RAW264.7细胞共同孵育48 h后,亲环素A的蛋白表达逐渐减弱,48 h、72 h分别较未处理组下降了54.5%±6.3%、59.8%±5.9%(P<0.05)。间接免疫荧光定位检测发现氧化型低密度脂蛋白显著抑制RAW264.7细胞中亲环素A在胞膜、胞浆中的表达,且随着处理时间的延长作用更明显。细胞内胆固醇酯/总胆固醇的比值由未处理组的28.3%±1.2%上升至48 h的42.3%±5.9%(P均<0.05)。结论氧化型低密度脂蛋白诱导的RAW264.7巨噬细胞泡沫化过程中,亲环素A的表达下调与细胞胆固醇蓄积密切相关。

Effect of Cyclophilin A on Cellular Cholesterol Accumulation in Lipid-Loaded Macrophages Induced by Oxidized Low Density Lipoprotein

Aim To observe the protein expression of Cyclophilin A in lipid-loaded macrophages induced by oxidized low density lipoprotein and its effect on cellular cholesterol accumulation.Methods RAW264.7 mouse macrophages were treated with 75 mg/L oxidized low density lipoprotein(ox-LDL) for different time(control,24 hours,48 hours and 72 hours).Western-blot analysis and immunofluorescence were used to detect protein expression of Cyclophilin A.High performance liquid chromatography(HPLC) analysis was peformed to determine the content of cellular total cholesterol and cholesterol ester.Results Western-blot analysis and immunofluorescence showed that the protein expression of Cyclophilin A was significantly decreased in a time-dependent manner in macrophages.High performance liquid chromatography(HPLC) analysis was peformed the content of cellular total cholesterol and cholesterol ester were increased greatly.Conclusions The protein expression of Cyclophilin A was down-regulated in lipid-loaded macrophages while the content of cellular total cholesterol and cholesterol ester were increased greatly.