摘要
目的探讨体外氧化修饰后的高密度脂蛋白(ox-HDL)对人外周血单核细胞源性泡沫细胞内胆固醇流出的影响。方法采用一次性密度梯度超速离心法从血浆中分离低密度脂蛋白(LDL)及高密度脂蛋白(HDL),分别以Cu2+诱导法将其氧化修饰成ox-LDL及ox-HDL。采用密度梯度离心法和塑料吸附法从人外周血中分离出单核细胞,以50nmol/L佛波酯(PMA)刺激48h使之转化为巨噬细胞。细胞分为对照组(ox-LDL组)、阳性对照组(HDL组)及实验组(ox-HDL组),对照组仅加入终浓度为80mg/L的ox-LDL;HDL组和ox-HDL组分别先加入终浓度均为50mg/L的HDL和ox-HDL共孵育1h后,再分别加入终浓度为80mg/L的ox-LDL,并于实验的0、6、12及24h测定细胞内总胆固醇(TC)、游离胆固醇(FC)及蛋白(Pro)含量。观察不同时间点各组细胞内TC/Pro比值的变化,并比较ox-HDL与HDL对细胞内TC/Pro比值影响的时效关系。结果成功地由体外氧化修饰了LDL及HDL并制备出理想的泡沫细胞模型。在实验的6、12及24h,ox-HDL组细胞内TC/Pro比值均较HDL组细胞高,差异具有统计学意义(P<0.05)。结论体外氧化修饰后的HDL导致其胆固醇逆向转运(RCT)功能与效率的降低。
AIM To study the effects of oxidized high density lipoprotein （ox-HDL） on cholesterol efflux of human monocyte-derived foam cells. METHODS Low density lipoprotein （LDL） and high density lipoprotein （HDL） were isolated from human plasma by one time density gradient centrifugation, and Cu^2＋ at concentration of 10 μmol/L was used to induce the oxidation of LDL （ox-LDL）. Monocytes were isolated from human peripheral blood by Ficoll-Hypaque density gradient centrifugation and plastic adsorptive process. The isolated cells were induced and stimulated by phorbol 12-myristate 13-acetate （PMA） at concentration of 50 nmol/L for 48 h to transfer them to macrophages. The cells were then allocated to control group （ ox-LDL group ）, positive control group （ HDL group ） and experimental group （ox-HDL group）, ox-LDL alone at a final concentration of 80mg/L was added to control group, while HDL and ox-HDL at 50 mg/L were co-incubated in HDL group and ox-HDL group for 1h, followed by addition of ox-LDL at a final concentration of 80mg/L to both groups. The total cholesterol （ TC ） , free cholesterol （FC） and protein （Pro） in cultured cells were detected at 6, 12 and 24 h of culture. The ratio of TC to Pro in cells at different time points was observed and the time-effect relationship of HDL and ox-HDL to cells was compared. RESULTS The isolated LDL and HDL were successfully oxidative modified in vitro and a human peripheral blood monocyte-derived foam cell model was established. Ratio of TC to Pro at 6, 12 and 24 h in ox-HDL group was significantly higher than that of HDL group （P 〈 0.05）. CONCLUSION The reverse cholesterol transport （RCT） capacity and efficiency of HDL in cells decrease greatly following oxidization in vitro.
出处
《心脏杂志》
CAS
2008年第4期373-375,380,共4页
Chinese Heart Journal
基金
广东省自然科学基金资助(06024444)
关键词
高密度脂蛋白
氧化修饰
泡沫细胞
胆固醇
流出
High density lipoprotein
Oxidative modification
Foam cells
Cholesterol
Efflux
