Takahashi T, Eitzman B, Bossert N L, Walmer D, Sparrow K, Flanders K C, McLachlan J, Nelson K G
Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Cell Growth Differ. 1994 Sep;5(9):919-35.
Increasing evidence suggests that the differential regulation of multiple peptide growth factors by steroid hormones contributes significantly to the pleiotropic effects elicited in target tissues. We report here an evaluation of the effects of the potent estrogen, diethylstilbestrol, on the expression of the three mammalian transforming growth factor beta (TGF beta) isoforms, TGF beta 1, TGF beta 2, and TGF beta 3, in both the uterus and the vagina of the prepubescent mouse. Immunohistochemical protein detection, in situ hybridization, and Northern RNA analyses demonstrate overlapping but distinct time-dependent and site-specific induction of all three TGF beta genes in the reproductive tract in response to estrogen. Temporal analysis of steady-state levels of the TGF beta mRNAs in the uterus by Northern blotting clearly demonstrates that diethylstilbestrol significantly but transiently up-regulates TGF beta 3 mRNA within 30 min and TGF beta 1 and TGF beta 2 mRNAs by 3 h with decreases to/or below control levels by 6 h. The vagina also responds to diethylstilbestrol with similar kinetics of induction for TGF beta 2 and TGF beta 3 mRNAs as that observed in the uterus; however, TGF beta 1 mRNA levels increase gradually and peak around 16 h after treatment. Investigation of the steroid specificity demonstrates predominant estrogen specificity in the control of TGF beta expression in the immature mouse reproductive tract. In situ hybridization localizes the mRNAs for all three TGF beta isoforms, primarily to the uterine and vaginal epithelium. Unlike the transient nature of TGF beta mRNA induction elicited by estrogen, immunohistochemistry demonstrates that estrogen treatment results in a more prolonged elevation of the proteins for TGF beta 1, TGF beta 2, and TGF beta 3 in the epithelium of both tissues. Investigation of specific binding of 125I-TGF beta 1 by affinity labeling reveals the existence of the receptor/binding proteins (types I, II, and III) in the uterus. Estrogen treatment significantly reduces binding to each of these components in the uterus, which suggests that estrogen may modulate TGF beta responsiveness at the receptor level. A comparison of TGF beta mRNA expression to the induction of other estrogen-regulated genes, TGF alpha, insulin-like growth factor-1, c-myc, progesterone receptor and lactotransferrin reveals that, in general, the TGF beta transcript levels are regulated in a more transient manner by estrogen.(ABSTRACT TRUNCATED AT 400 WORDS)
越来越多的证据表明，类固醇激素对多种肽生长因子的差异调节在很大程度上促成了靶组织中产生的多效性效应。我们在此报告对强效雌激素己烯雌酚对青春期前小鼠子宫和阴道中三种哺乳动物转化生长因子β（TGFβ）亚型，即TGFβ1、TGFβ2和TGFβ3表达的影响的评估。免疫组织化学蛋白质检测、原位杂交和Northern RNA分析表明，响应雌激素时，生殖道中所有三种TGFβ基因均呈现重叠但不同的时间依赖性和位点特异性诱导。通过Northern印迹对子宫中TGFβ mRNA稳态水平进行的时间分析清楚地表明，己烯雌酚在30分钟内显著但短暂地上调TGFβ3 mRNA，在3小时上调TGFβ1和TGFβ2 mRNA，到6小时时降至对照水平或低于对照水平。阴道对己烯雌酚的反应与子宫中观察到的TGFβ2和TGFβ3 mRNA诱导动力学相似；然而，TGFβ1 mRNA水平逐渐升高并在处理后约16小时达到峰值。类固醇特异性研究表明，在未成熟小鼠生殖道中，TGFβ表达的控制主要具有雌激素特异性。原位杂交将所有三种TGFβ亚型的mRNA主要定位在子宫和阴道上皮。与雌激素引起的TGFβ mRNA诱导的短暂性质不同，免疫组织化学表明，雌激素处理导致两种组织上皮中TGFβ1、TGFβ2和TGFβ3的蛋白质水平升高时间更长。通过亲和标记对125I-TGFβ1特异性结合的研究揭示了子宫中存在受体/结合蛋白（I、II和III型）。雌激素处理显著降低了子宫中与这些成分的结合，这表明雌激素可能在受体水平调节TGFβ反应性。将TGFβ mRNA表达与其他雌激素调节基因，即TGFα、胰岛素样生长因子-1、c-myc孕酮受体和乳铁传递蛋白的诱导进行比较发现，一般来说，TGFβ转录水平受雌激素调节的方式更为短暂。（摘要截于400字）
