辛伐他汀抑制机械牵张力和氧化低密度脂蛋白所致血管平滑肌细胞全基因组甲基化水平的降低

摘要

目的 探讨小鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)在机械牵张力(stretch stress,SS)和氧化低密度脂蛋白(oxidized low-density lipoprotein,oxLDL)作用下全基因组甲基化水平的变化,并进一步考察辛伐他汀(simvastatin,SIM)对此变化的影响.方法 血浆制备氧化型低密度脂蛋白,体外常规培养VSMCs,施加机械牵张力和/或氧化型低密度脂蛋白,或用辛伐他汀预处理1h后再施加刺激,用荧光探针5-甲基胞嘧啶检测VSMCs全基因组甲基化水平.以细胞免疫荧光定量阳性率和SPSS统计软件对甲基化水平进行分析.结果 机械牵张力和氧化型低密度脂蛋白均可降低VSMCs的全基因组甲基化水平,且两者联合作用大于单一因素,辛伐他汀预处理VSMCs可部分抑制机械牵张力和/或氧化低密度脂蛋白诱导的全基因组甲基化水平降低.结论 机械牵张力和氧化低密度脂蛋白可分别促进VSMCs全基因组甲基化水平降低,当两者共处理时呈相加作用,辛伐他汀可部分抑制上述效应.%Objective To investigate genome-wide methylation in mouse vascular smooth muscle cells (VSMCs) induced by stretch stress(SS) and oxidized low-density lipoprotein (oxLDL),and the role of simvastatin in this process.Methods VSMCs were treated with SS and/or oxLDL prepared from plasma with or without pre-incubation of simvastatin for 60 min.The methylation was detected using 5-methylcytosine fluorescent probe.The level of methylation was determined by fluorescence positive rate which was quantified using SPSS analysis.Results Either SS or ox-LDL decreased the genome-wide methylation of VSMCs.The combination of both caused more significant reduction.Simvastatin partly inhibited the effect induced by SS and/or oxLDL.Conclusion Both SS and ox-LDL can reduce genome-wide methylation in VSMCs independently,and to a higher degree when applied together.Simvastatin can partly abolish this effect.