丹参酮ⅡA对泡沫细胞胆固醇平衡的影响

目的通过体外细胞实验阐明丹参酮ⅡA对泡沫细胞胆固醇平衡的影响。方法体外培养小鼠RAW264.7细胞,以氧化型低密度脂蛋白诱导为泡沫细胞模型,并用不同浓度的丹参酮ⅡA进行处理,通过油红O染色观察细胞内脂质堆积情况,酶比色法定量检测细胞内总胆固醇和胆固醇酯的变化,荧光定量PCR和WesternBlot检测细胞中CD36、三磷酸腺苷结合盒转运体A1(ABCA1)、肝脏X受体α(LXRα)、过氧化体增殖物激活型受体α(PPARα)及PPARγ的mRNA和蛋白表达。结果 0～20 mg/L的丹参酮ⅡA对泡沫细胞增殖活力无明显影响,20 mg/L丹参酮ⅡA干预后,泡沫细胞内胆固醇酯与总胆固醇的比值显著降低,细胞内脂质累积减少,并上调AB-CA1、LXRα和PPARα的mRNA和蛋白表达,但对CD36表达无明显作用。结论丹参酮ⅡA能抑制泡沫细胞的形成,其机制可能是通过诱导PPARα、LXRα和ABCA1表达,促进胆固醇的外排。

Effect of Tanshinone Ⅱ A on Cholesterol Homeostasis in Foam Cells

AimThe effect of tanshinoneⅡA on cholesterol homeostasis in foam cells was studied in vitro.MethodsThe foam cell induced from RAW264.7 macrophage with oxidized low density lipoprotein(ox-LDL) were treated with different concentration of tanshinoneⅡA.The relative cell viability were detected by MTT methods,and the change of total cholesterol and cholesterol ester in the cells were detected with the enzyme colorimetric quantifies.The lipid accumulation in cell was observed by oil red O dyeing,then the expressions of CD36,ATP binding cassette transporter A1(ABCA1),liver X receptor α(LXRα) and peroxisome proliferator activated receptors γ(PPARγ),PPARα were detected with the methods of fluorescent quantitation PCR and Western Blot.ResultsThe cell viability was not affected when tanshinone ⅡA concentrations were in the range of 0～20 mg/L.The ratio of cholesterol ester and total cholesterol decreased and lipid accumulation decreased when the foam cells were treated with 20 mg/L tanshinone ⅡA.Meanwhile,the expression of ABCA1,LXRα,PPARα were increased,but the expression of CD36 had no obvious variance.ConclusionTanshinoneⅡA can inhibit the formation of foam cells induced from RAW264.7 by ox-LDL,the mechanism is possibly related to inducing the expressions of PPARα,LXRα and ABCA1 and promoting the excretion of cholesterol.