低密度脂蛋白诱导巨噬细胞Raw264.7脂质筏的聚集

Native Low Density Lipoprotein Induces Lipid Raft Aggregation in Macrophages Raw264.7

目的:探究低密度脂蛋白(LDL)与脂质筏之间的关系。方法:运用荧光漂白恢复技术(FRAP),对LDL刺激的细胞和未经LDL刺激的细胞进行观测;采用密度梯度离心的方法分离脂质筏,对各层中胆固醇含量进行测定,通过Western Blot对脂质筏标志性蛋白flotillin-1,caveolin-1进行分析;β-环糊精孵育后,扫描电子显微镜观测细胞形态。结果:经LDL刺激的Raw264.7细胞表现出荧光漂白恢复时间延长;脂质筏区的胆固醇含量增多,脂质筏区标志性蛋白flotillin-1,caveolin-1增加;β-环糊精孵育后细胞形态发生改变,细胞胆固醇含量降低。结论:LDL能诱导细胞膜上脂质筏的聚集。

Objective:To explore the relationship between LDL and the lipid raft in macrophages Raw264.7.Methods:The fluidity of cell membrane in the Raw 264.7stimulated with or without LDL was observed by fluorescence recovery after photobleaching(FRAP).After density gradient centrifugation,the total cholesterol in different layer of the product was separated and measured.The content of flotillin-1and caveolin-1were analyzed by Western Blot.Then,cells were incubated withβ-cyclodextrin,and the cellular morphology was detected by scanning electron microscope.Results:Recovery time after bleaching in the Raw 264.7cell stimulated with LDL was extended.More cholesterol and increased flotillin-1and caveolin-1were presented in the lipid rafts.After incubation withβ-cyclodextrin,the cellular morphology was changed and cholesterol content was decreased.Conclusion:LDL may induce the aggregation of lipid rafts in the membrane of Raw 264.7cells.