17β-雌二醇对体外培养人成骨细胞CTGF和PAIP-1基因表达的作用

目的　观察结缔组织生长因子 (CTGF)和多聚腺苷酸结合蛋白相互作用蛋白 1(PAIP 1)mRNA在体外培养的人成骨细胞增殖分化不同阶段的表达 ,研究 17β- 雌二醇 (E2 )对成骨细胞CTGF和PAIP 1mRNA表达的作用 ,探讨雌激素对骨组织保护作用的新机制。方法　用改良的钙 钴法ALP染色 ,vanGieson法 1型胶原染色 ,0. 1%茜素红矿化结节染色 ,半定量RT- PCR检测成骨细胞碱性磷酸酶 (ALP)、骨钙素 (OC)和 1型胶原mRNA的表达 ,半定量RT- PCR和Northernblot方法检测成骨细胞CTGF和PAIP- 1mRNA表达。结果　半定量RT -PCR和组织化学染色的结果均表明 ,成骨细胞接种培养后 0～11d为细胞增殖阶段 ,7～ 15d为骨基质成熟阶段 ,15d后为骨基质矿化阶段 ;在成骨细胞培养的不同阶段 ,均检测到CTGF和PAIP- 1mRNA的表达 ,E2 可显著下调成骨细胞CTGFmRNA的表达 ,呈时间剂量依赖关系 (P <0 . 0 1) ,但对PAIP 1mRNA表达无明显作用。结论　E2 时间剂量依赖性下调成骨细胞CTGFmRNA的表达 ,但对PAIP 1mRNA表达无明显影响。

Effects of 17beta-estradiol on expression of CTGF and PAIP-1 in human osteoblasts in bitro

Objective To observe the expression of connective tissue growth factor(CTGF) and polyadenylate-binding protein interacting protein 1(PAIP-1) mRNA during human osteoblast proliferation and differentiation,investigate the effects of 17beta-estradiol on expression of CTGF and PAIP-1,and try to provide new mechanisms of estrogens on bone tissues. Methods The expression of type 1 collagen,alkaline phosphatase and osteocalcin was determined by semiquantitative RT-PCR.Cultured cells were stained with van Gieson procedure and modified Gomori's assay.Mineralized matrix staining was performed with 0.1% Alizarin red.The expressions of CTGF and PAIP-1 mRNA was examined through semiquantitative RT-PCR and Northern blotting. Results By the combination of molecular and histochemical approaches,three stages of human osteoblast proliferation and differention can be defined as follows:cell proliferation(days 0-11),matrix maturation(day 7-15) and mineralization(days 15-). CTGF mRNA and PAIP-1 mRNA were all detected during three stages.RT-PCR and Northern blot showed that 17beta-estradiol downregulated the expression of CTGF mRNA,but had no effects on PAIP-1 mRNA.Conclusions 17beta-estradiolcan downregulate the expression of CTGF mRNA in human osteoblasts, but has no effects on the expression of PAIP-1 mRNA.