睾酮抑制大鼠血管平滑肌细胞泡沫化及机制研究

Inhitory effect of testosterone on foam formation in rat vascular smooth muscle cells and its mechanism

目的研究睾酮对氧化型低密度脂蛋白(ox-LDL)诱导大鼠血管平滑肌细胞(VSMC)转化为泡沫细胞的抑制作用,并探讨其可能机制。方法培养大鼠VSMC,分为对照组、ox-LDL组、低(1nmol/L)、中(10nmol/L)、高(100nmol/L)浓度睾酮组。另外,设置睾酮组(100nmol/L)、氟他胺组(1μmol/L)、睾酮与氟他胺合用组,并与ox-LDL共培养建立泡沫细胞模型。利用油红O染色及酶荧光法检测不同浓度睾酮及氟他胺预处理对VSMC内脂质含量的影响,免疫印迹法检测各组细胞内线粒体融合素2(Mfn2)、清道夫受体CD36和ATP结合盒转运蛋白A1(ABCA1)的表达变化。结果与ox-LDL组比较,不同浓度睾酮组VSMC脂质蓄积减少,总胆固醇、游离胆固醇和胆固醇酯的含量均降低(P<0.05),Mfn2和ABCA1表达增加(P<0.05),CD36表达降低(P<0.05)。与睾酮组比较,睾酮与氟他胺合用组VSMC脂质蓄积增加,总胆固醇、游离胆固醇和胆固醇酯的含量均增加(P<0.05),Mfn2和ABCA1表达降低(P<0.05),CD36表达增加(P<0.05)。结论睾酮以雄激素受体依赖的方式,抑制ox-LDL诱导的VSMC泡沫化过程,其作用与睾酮上调Mfn2表达进而调节CD36和ABCA1表达有关。

Objective To study the inhibitory effect of testosterone on ox-LDL-induced foam formation in rat vascular smooth muscle cells（VSMC）and its mechanism.Methods VSMC were divided into control group,ox-LDL group,1nmol/L testosterone group,10nmol/L testosterone group,100nmol/L testosterone group.A model of foam cells was established after the last 4groups were cultured in 50μg/ml ox-LDL for 48 h.The 100nmol/L testosterone group,1μmol/L flutamide group,testosterone＋flutamide group were cocultured with ox-LDL to establish the model of foam cells.Effect of testosterone and flutamide pretreated at different concentrations on intracellular lipid of VSMC was detected by enzymatic fluorometry with oil Red O staining.Expressions of Mfn2,CD36,ATP and ABCA1 were detected by Western blot.Results The accumulated lipid level was significantly lower in different testosterone level groups than in ox-LDL group（P〈0.05）.The expression levels of Mfn2 and ABCA1were significantly higher while that of CD36 was significantly lower in different testosterone level groups than in ox-LDL group（P〈0.05）.The serum levels of lipid,TC,free cholesterol,cholesterol ester were significantly higher while the expression levels of Mfn2 and ABCA1were significantly lower and that of CD36 was significantly higher in testosterone＋flutamide group than in testosterone group（P〈0.05）.Conclusion Testosterone inhibits ox-LDL-induced foam formation in rat VSMC in an androgen receptor-dependent manner by upregulating the expression of Mfn2,CD36 and ABCA1.