【摘要】 目的:研究大豆苷原对成骨细胞MC3T3-E1甾体激素受体辅激活因子1（steroid receptorcoactivator-1,SRC-1）和核受体辅抑制因子（nuclear receptor corepressor,NcoR）表达的调节作用及其机制。方法:体外培养MC3T3-E1细胞于含2%胎牛血清（fetal bovine serum,FBS）的α最低必须培养基（α-minimal essential medium,α-MEM）中,给予不同浓度大豆苷原或10^-8mol/L的雌二醇作用3 d后收获细胞,采用蛋白质印迹法观察SRC-1和NcoR蛋白的表达水平。分别应用雌激素受体（estrogen receptor,ER）拮抗剂ICI182780(Faslodex,ICI,10^-7 mol/L)和雌激素受体α（estrogen receptorα,ERα）特异性拮抗剂(methyl-piperidino-pyrazole,MPP,10^-6 mol/L)干预,观察大豆苷原对细胞SRC-1和NcoR蛋白表达水平的影响。结果:大豆苷原可上调MC3T3-E1细胞SRC-1的表达,10^-7mol/L和10^-5mol/L大豆苷原组SRC-1的蛋白水平分别增加至对照组的2.5倍（P<0.05）和2倍（P<0.05）。各剂量组NcoR表达水平与对照组比较差异无统计学意义。雌二醇组SRC-1水平与对照组比较未见明显变化,而其NcoR表达水平较对照组下调35%（P<0.05）。ICI182780可拮抗大豆苷原对SRC-1的上调作用。在ICI182780作用下,各剂量组SRC-1蛋白水平与对照组比较差异无统计学意义;MPP干预下,10^-7mol/L和10^-5 mol/L大豆苷原组SRC-1的蛋白水平分别为对照组的1.8倍（P<0.05）和2.4倍（P<0.05）。结论:大豆苷原可增加成骨细胞SRC-1的蛋白表达水平,提高细胞SRC-1/NcoR比值。ERβ参与了大豆苷原对SRC-1的调节过程。成骨细胞内SRC-1蛋白的增加和SRC-1/NcoR比值的提高是大豆苷原促进成骨细胞分化的机制之一。更多还原

【Abstract】 Objective:To investigate the roles of daidzein in the expressions of steroid receptor coactivator-1（SRC-1） and nuclear receptor corepressor（NcoR） in MC3T3-E1 osteoblastic cells. Methods:MC3T3-E1 cells were cultured inα-minimal essential medium（α-MEM） containing 2%fetal bovine serum and treated with various concentrations of daidzein(10^-9,10^-7 and 10^-5 mol/L) or 17β-estradiol at 10^-8 mol/L for 3 d.The protein levels of SRC-1 and NcoR in MC3T3-E1 cells were determined by Western blotting.Estrogen receptor（ER） antagonist ICI182780 at 10^-7 mol/L or specific ERαantagonist methyl-piperidino-pyrazole （MPP） at 10^-6 mol/L were used to block the corresponding receptors,and then MC3T3-E1 cells were treated with daidzein at 10^-7 mol/L or 10^-5 mol/L for 3 d.SRC-1 and NcoR protein levels were detected by Western blotting. Results:The protein levels of SRC-1 increased by 2.5 fold（P<0.05） and 2 fold（P<0.05） by 10^-7 and 10^-5 mol/L of daidzein respectively,while the NcoR levels were not significantly altered.17β-Estradiol at dose of 10^-8 mol/L did not affect the expression of SRC-1 but decreased NcoR protein expression by 35% （P<0.05）.Compared with the control,daidzein at 10^-7 and 10^-5 mol/L did not increase SRC-1 expression when ERs were blocked by antagonist ICI182780.Daidzein at 10^-7 and 10^-5 mol/L up-regulated SRC-1 by 1.8 fold（P<0.05） and 2.4 fold（P<0.05） respectively while ERαwas blocked by MPP. Conclusion:Daidzein increases protein level of SRC-1 and the ratio of SRC-1/NcoR.ERβ,instead of ERα, participates in the action of daidzein in regulating SRC-1 expression.Up-regulation of SRC-1 and increase of SRC-1/NcoR are part of the mechanism of the estrogenic effect of daidzein in improving osteogenesis.更多还原