【摘要】 探讨雌激素在动脉粥样硬化形成过程中的角色,特别是研究雌二醇(estradiol)对氧化低密度脂蛋白(ox-LDL)诱导的鼠单核/巨噬细胞源性泡沫细胞J774a.1中胆固醇代谢的影响。以鼠单核/巨噬细胞J774a.1作为研究对象,分为空白对照组、泡沫细胞组和雌二醇组,用不同浓度的雌二醇(1、0.1和0.01μmol·L-1)对泡沫细胞进行干预。采用油红O染色观察泡沫细胞形成,胆固醇氧化酶荧光法检测泡沫细胞内胆固醇含量的变化;蛋白质印迹法、实时荧光定量PCR法(RTFQ-PCR)检测泡沫细胞表面清道夫受体(SR-BⅠ)的表达。结果表明,与对照组相比,泡沫细胞组内总胆固醇及胆固醇酯含量升高(P<0.001)、SR-BⅠ基因表达降低(P<0.01);与泡沫细胞组相比,不同浓度雌二醇干预组细胞内总胆固醇及胆固醇酯含量下降(P<0.05)、SR-BⅠ蛋白及基因表达升高(P<0.01),呈现出一定的浓度依赖性。结果提示,雌二醇通过降低泡沫细胞内胆固醇含量、上调SR-BⅠ的表达,从而抑制鼠单核/巨噬细胞源性泡沫细胞的形成。更多还原

【Abstract】 To explore the anti-atherosclerotic mechanism of estrogen and especially observe the effect of estradiol on the content of cholesterol in J774a.1 mouse mononuclear/macrophage-derived foam cells which were incubated with oxidized low-density lipoproteins(ox-LDL). J774a.1 mouse mononuclear/macrophages were incubated with ox-LDL or with both ox-LDL and estradiol(1, 0.1 or 0.01 μmol·L-1). Oil red O staining was used to observe the formation of foam cells, and cholesterol oxidase fluorometric was used to determine the content of cellular cholesterol content. Western blotting and RTFQ-PCR were used to observe the expressions of scavenger receptor class B type I(SR-BⅠ) in J774a.1 foam cells. Compared with the control cells, J774a.1 mouse mononuclear/macrophage-derived foam cells showed significantly increased contents of total cholesterol and cholesterol ester(P < 0.001) and decreased SR-BⅠ mRNA expression(P < 0.01). Estradiol treatment significantly lowered the contents of total cholesterol and cholesterol ester(P < 0.05), and increased SR-BⅠprotein and mRNA expression(P < 0.01) in the foam cells in a dose-dependent manner. Estradiol can inhibit the formation of mononuclear/macrophage-derived foam cells by decreasing the contents of total cholesterol and cholesterol ester and up-regulating the expression of SR-BⅠ in the foam cells.更多还原