LDLR DNA甲基化在Hcy致泡沫细胞形成中作用机制的研究

摘要

目的 探讨低密度脂蛋白受体(LDLR)DNA甲基化在同型半胱氨酸(Hcy)致泡沫细胞形成中的作用机制.方法 原代培养单核细胞,采用佛波酯( PMA)和ox - LDL刺激复制泡沫细胞模型,用50、100、200、500μM Hcy干预72h,油红0染色半定量分析泡沫细胞数量,酶免法检测泡沫细胞中ox - LDL含量；同位素法测定LDLR活性,分析Hcy对LDLR的影响,巢式降落式PCR(nMS- PCR)法检测LDLR甲基化的变化,观察Hcy对LDLR的作用.结果 泡沫细胞与0、50、100、200、500μM Hcy培养72h后,泡沫细胞数量明显增加,细胞中ox-LDL含量和LDLR活性明显增加,LDLR DNA呈低甲基化改变,与对照组比较差异有统计学意义(P＜0.05,P＜0.01).结论 Hcy引起泡沫细胞形成除了氧化应激外,LDLR DNA甲基化异常也可能是泡沫细胞形成和Hcy引起AS的又一重要机制.%Objective To explore the mechanism of low density lipoprotein receptor (LDLR) DNA methyla-tion induced the formation of foam cells in homocysteine (Hey). Methods Replicate foam cell modeled by phorbol ester( PMA) and ox - LDL stimulation. 0,50,100,200,500jjlM concentrations of Hey were added into the primary cultured mononuclear cells for 72h. The quantity of foam cells were detected by oil red 0 stained; The ox - LDL content of foam cells were determined by ELJSA; LDLR activity of foam cells were detected by isotope method; and LDLR methylation were detected by Nms - PCR. Results After the foam cells were treated by 0,50,100,200,500 y,M Hey for 72 h, the quantity of foam cells,the levels of ox-LDL and LDLR activity increased significantly, it showed that LDLR DNA were hypomethylated, there were significantly, compared with control group(P<0,05 or <0.01). Conclusion The abnormalities of LDLR DNA methylation may play an important role in the formation of foam cells and the pathogenesis of atherosclerosis.