雌二醇对骨形态发生蛋白受体表达的影响(英文)

Effects of 17β-estradiol on the gene expression of bone morphoge neticprotein receptor

目的:研究骨髓基质细胞向成骨细胞分化过程中,雌二醇对其骨形态发生蛋白受体(BMPR)ⅠA,ⅠBmRNA表达的影响,探讨雌二醇对成骨细胞生成的作用,试阐明绝经后高转换骨代谢始动环节的可能机制。方法:SD大鼠骨髓基质细胞在生长培养基中传代培养后,用1,25(OH)2D3和地塞米松(DEX)诱导骨髓基质细胞向成骨细胞分化,17β-雌二醇(E2)处理培养细胞,观察E2对骨髓基质细胞分化过程中骨形态发生蛋白受体ⅠA、ⅠBmRNA、碱性磷酸酶(ALP)活性和Ⅰ型胶原合成的影响,β-actin作内对照半定量RT-PCR分析骨形态发生蛋白受体ⅠA,ⅠBmRNA的表达,以α-磷酸奈酚为底物,测定细胞碱性磷酸酶的活性,VanGieson染色法显示Ⅰ型胶原的含量。结果:E2能明显抑制骨髓基质细胞分化过程中BMPR-ⅠAmRNA的表达,且呈剂量依赖性,随E2浓度增加(0～1×103nmol/L)BMPR-ⅠAmRNA从(27.0±3.4)%降至(17.0±1.8)%(t=5.2,P<0.01)和(9.3±1.6)%(t=9.2,P<0.01);BMPR-ⅠBmRNA随E2浓度增加而增加,从(2.0±0.8)%增至(4.8±1.5)%(t=3.3,P<0.05)和(17.2±2.2)%(t=13,P<0.01)。Northernblot结果显示在上述E2浓度时BMPR-ⅠAmRNA的表达从4.21±0.36降至1.24±0.10(t=18.2,P<0.01);BMPR-ⅠBmRNA的表达从1.72±0.11增至3.73±0.31(t=12.2,P<0.01)。ALP活性随E2浓度增加而?

AIM:To investigate the effects of 17β-estradiol (E 2 )on the gene expression of typeⅠA and typeⅠB bone morphogenetic protein recept or(BMPR-ⅠA,ⅠB)in rat bone marrow stromal cells exposu red to the di fferentiation medium an d to elucidate the effects of E 2 on osteoblastogenesis.METHODS:Adherent bone marrow stromal cells w ere cul tured in differenti-ation mediumcontaining DEX(1×10 -7 mol /L)and 1,25(OH) 2 D 3 (1×10 -9 mol /L)and different concentrations of E 2 .The gene expression of BMPR-ⅠA,ⅠB was quantified by semiquantitative R T-PCRand demonstrated by Northern blot.RESULTS:E 2 evidently inhibited the expression of BMPR-ⅠA mRNA in bone marrow stromal cell.The suppre ssion was dose dependent.When ex-amined under various concent ration s of E 2 (0-1×10 -6 mol /L),the ex-pression of BMPR-ⅠA mRNA were decreased from(27.0 ±3.4)%to(22.3±2.6)%(t=2.2,P>0.05),(17.0±1. 8)%(t=5.2,P<0.01)and(9.3±1.6)%(t=9.2,P<0.01 ).Increase of BMPR-ⅠB mRNA with increasing of E 2 concentrationfrom(2.0±0.8)%to(4.8±1.5)%,t=3.3,P <0.05,(8.4±1.4)%(t=7.9,P<0.01)and(17.3±2. 2)%(t=13.1,P<0.01)above the control.Northern blot showed the ex pression of BMPR-ⅠA mRNA decreased from 4.21±0.36to1.24±0.10 (t=18.2,P<0.01)and the expression of BMPR-ⅠB mRNA increased from 1.72±0.11to 3.73±0.31(t=12.2,P<0.01).The activit y of ALP decreased significantly at higher concentrations of E 2 ,from(42.6±2.5)U /g to(17.9±2.0)U /g(t=15,P<0 .01),(10.8±1.5)U /g(t=22,P<0.01)and(3.6±0.7) U /g(t=30,P<0.01).The amount of typeⅠcollagen was suppressed by E 2 .CONCLUSION:E_2 can suppress the gene expression of BMPR-ⅠA of bone marrow stromal cells and inhibited osteoblastogenesis in vitro.