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目的观察雌二醇和孕酮对人成骨细胞胰岛素受体底物(IRS)表达的影响。探讨雌、孕激素对绝经后骨质疏松症的作用机制。方法用半定量RTPCR检测细胞IRS1、IRS2mRNA的表达;分别用免疫印迹和免疫共沉淀检测细胞IRS1、IRS2蛋白表达及磷酸化。结果雌二醇和孕酮均使人成骨细胞IRS2mRNA的表达上调,分别为对照组的421%±68%(P<0.05)和327%±54%(P<0.05),两者联合干预能进一步诱导人成骨细胞IRS2mRNA的表达上调496%±54%(P<0.01),但IRS1mRNA的表达不受影响(P>0.05)。雌二醇、孕酮、雌二醇和孕酮联合干预上调细胞IRS2蛋白的表达,分别为对照组的487%±65%、507%±54%和552%±47%,雌二醇、孕酮、雌二醇和孕酮联合干预使IRS1去磷酸化,分别为对照组的54%±7.6%(P<0.05),37%±4.2%,21.2%±3.0%(P<0.01),对IRS1蛋白的表达无影响。结论雌二醇和孕酮均可使人成骨细胞IRS2mRNA及蛋白的表达上调,并促使IRS2的磷酸化,二者之间存在正性协同效应。虽然二者在转录和翻译水平对IRS1表达无影响,但可促使IRS1蛋白去磷酸化。因而,雌激素与孕激素合用在骨质疏松的防治中可能具有重要的意义。
Objective To investigate the effects of estradiol and progesterone on the expression of insulin receptor substrate (IRS) in human osteoblasts. To explore the mechanism of action of estrogen and progesterone on postmenopausal osteoporosis. Methods The expression of IRS1 and IRS2 mRNA was detected by semi-quantitative RT-PCR. The expressions of IRS1 and IRS2 protein and phosphorylation were detected by Western blotting and co-immunoprecipitation. Results Both estradiol and progesterone up-regulated the expression of IRS2 mRNA in human osteoblasts, which were 421% ± 68% (P <0.05) and 327% ± 54% (P <0.05) respectively in the control group, and the combined intervention could further The expression of IRS2 mRNA in human osteoblasts was up-regulated by 496% ± 54% (P <0.01), but the expression of IRS1 mRNA was not affected (P> 0.05). The intervention of estradiol, progesterone, estradiol and progesterone up-regulated the expression of IRS2 protein in cells, which were 487% ± 65%, 507% ± 54% and 552% ± 47% (P <0.05), 37% ± 4.2%, 21.2% ± 3.0% (P <0.01) of the IRS1 protein, respectively. The IRS1 protein No effect on expression. Conclusion Both estradiol and progesterone can up-regulate the expression of IRS2 mRNA and protein in human osteoblasts and promote the phosphorylation of IRS2, with a positive synergistic effect. Although both have no effect on IRS1 expression at the transcription and translation level, they can promote IRS1 protein dephosphorylation. Therefore, the combined use of estrogen and progesterone in the prevention and treatment of osteoporosis may have important significance.