【摘要】 目的初步探讨Daxx在氧化型低密度脂蛋白(ox-LDL)诱导巨噬细胞凋亡中的作用。方法通过MTT比色法检测ox-LDL对小鼠源性巨噬细胞(RAW264.7)细胞生长的影响:用AO/EB染色、流式细胞仪和DNA断裂片段分析研究ox-LDL诱导的细胞凋亡。Real time PCR检测细胞内Daxx mRNA的表达情况。结果ox-LDL能抑制RAW264.7细胞的生长,抑制作用呈剂量-效应关系;50 mg/L ox-LDL处理RAW 264.7细胞48 h后,AO/EB染色细胞呈凋亡特征性改变,并且DNA断裂片段分析显示电泳图出现梯形条带;流式细胞检测显示相同时间不同浓度ox-LDL(0、12.5、25、50、75 mg/L)处理RAW264.7细胞48 h和相同浓度不同时间(50 mg/L,487、2 h)处理细胞,细胞凋亡率逐渐升高;Real timePCR结果表明不同时间和不同浓度的ox-LDL处理RAW264.7细胞后,Daxx mRNA表达水平呈时间和浓度依赖性增加,其中50 mg/L ox-LDL处理细胞48 h组Daxx mRNA表达最高。结论ox-LDL有诱导RAW264.7巨噬细胞凋亡的作用,其机制可能与Daxx表达增高从而启动细胞凋亡有关。更多还原

【Abstract】 Objective To investigate the function of Daxx on oxidized low density lipoprotein(ox-LDL)-induced apoptosis in RAW264.7 murine macrophages.Methods RAW264.7 macrophages growth inhibition was measured by MTT assay.The effect of oxidized low density lipoprotein(ox-LDL)-induced apoptosis in RAW264.7 cells was researched by AO/EB fluorescence dyeing,flow Email:dfliao66@yahoo.com.cncytometry and DNA agarose,respectively.Real-time PCR detected the expression changes of apoptosis-related genes Daxx.Results Oxidized low density lipoprotein significantly inhibited the growth of RAW264.7 cells with a dose-dependent effect.After 48 hours exposure to 50 mg/L oxidized low density lipoprotein,partial cells showed typical apoptotic morphological changes under fluorescent microscopy.Apoptotic peak was found by flow cytometry.When RAW264.7 cells were exposed to oxidized low density lipoprotein(0、12.5、25、50、75 mg/L,48h;50 mg/L,48、72h),the apoptosis indexes were increased with a dose-dependent and time-dependent effect.RAW264.7 cells "Ladder" bands were observed after exposure to 50mg/L oxidized low density lipoprotein in 48h.Real-time PCR revealed that ox-LDL increased expression level of Daxx mRNA in a dose-dependent and time-dependent manner.Conclusions Oxidized low density lipoprotein could significantly induce apoptosis of RAW264.7 macrophages,and the mechanism of apoptosis is closely associated with up-regulation of the ratio of Daxx.更多还原