【摘要】 目的研究雌激素和高浓度胰岛素对胰岛素受体底物(IRS)-1和-2表达的分子机理。方法将IRS-1,2基因5′调控区克隆至含荧光素酶表达载体pGL3质粒,转染HeLa细胞,加雌激素(1nmol/L)或高浓度胰岛素(100nmol/L)培养,检测IRS-1,2基因5′调控区相对转录活性。结果高浓度胰岛素刺激细胞48h,IRS-2基因5′调控区相对转录活性减低,IRS-1无明显差异;雌激素处理显著增加IRS-1,2基因5′调控区的相对转录活性。结论高胰岛素可能通过作用于IRS-2基因5′调控区中胰岛素作用元件,使其转录活性降低。而雌激素则通过作用于IRS-1,2基因5′调控序列,使其转录活性提高,增强其表达。更多还原

【Abstract】 AIM: To study the molecular mechanism in modulation of expression of insulin receptor substrate-1 and-2 (IRS-1,-2) by estrogen and high concentration of insulin. METHODS: The 5′-regulatory regions of IRS-1 and IRS-2 gene were cloned into the pGL3 plasmid with luciferase reporter, and the clones were transfected into HeLa cells. The cells were incubated with estradiol (1 nmol/L) and high concentration of insulin (100 nmol/L). The relatively transcriptional activity of the 5′-regulatory regions of IRS-1 and IRS-2 gene was detected. RESULTS: It was found that the relatively transcriptional activity of the 5′-modulatory regions of IRS-2 reduced markedly after cells were incubated with 100 nmol/L insulin (P<0.05), but that of IRS-1 was not affected. Estradiol increased the relatively transcriptional activity of the 5′-regulatory regions of IRS-1 and-2 distinctly (P<0.05). CONCLUSIONS: High concentration of insulin decreases the expression of IRS-2 by acting on its insulin reactive element, and estradiol elevates the expression of IRS-1 and-2 by acting on their 5′-modulatory regions. [更多还原