DES and the Regulation of the Uterine Cytodifferentiation

描述（由申请人提供）：己烯雌酚（DES）是第一种用于孕妇预防流产的合成雌激素化合物。在1947年至1971年期间，超过一百万名美国妇女在子宫内暴露于DES，这使她们在年轻时易患生殖道图案缺陷和阴道或子宫颈透明细胞腺癌。生殖系统发育的变化随后导致了这些妇女的不孕问题。更糟糕的是，DES被引入环境中是因为它能够加速牛的生长。仅在1971年，就有超过27，600公斤的DES被用于牲畜饲料。不幸的是，我们对DES影响生殖道发育的分子机制仍然知之甚少。解决这一机制很重要，因为我们目前接触的许多合成和天然化学物质也模仿雌激素，并可能以类似于DES的方式影响下一代的健康。该建议将剖析DES在女性生殖道（FRT）发育过程中影响的遗传途径。我们的初步研究表明，在子宫细胞分化的关键时期，DES调控了几个发育控制基因。特别是，同源结构域蛋白Msx2在抵消DES对发育FRT的影响方面显得至关重要，因为DES在Msx2突变体中诱导非常显著的生殖模式缺陷，这是由这些突变体中改变的分子变化引起的。目前的资助将继续测试DES可以通过影响控制子宫细胞分化的遗传途径来改变子宫上皮细胞命运的假设。在目标1中，将严格检查Msx2在子宫和阴道发育以及DES诱导的FRT畸形中的作用。在目的II中，我们将使用体内功能获得和丧失的方法来检查Klf4对于DES诱导的子宫化生是否是必要的和足够的。最后，在目标III中，我们将检验DES通过调节Wnt通路影响管腔上皮结构的假设。通过完成这些研究，我们应该能够建立控制子宫发育的遗传途径，并解决DES如何通过调节这些途径引起异常FRT模式。我们的长期目标是利用小鼠作为模型来研究生殖道发育以及外源性因素如何影响这一过程。

DESCRIPTION (provided by applicant): Diethylstilbestrol (DES) is the first synthetic estrogenic compound prescribed to pregnant women to prevent miscarriage. Between 1947 and 1971, more than one million U.S. women were exposed to DES in utero, which predisposed them to reproductive tract patterning defects and clear-cell adenocarcinoma of the vagina or cervix at a young age. Changes in reproductive system development have subsequently led to infertility problems for these women. Even worse, DES was introduced into the environment for its ability to accelerate cattle growth. In 1971 alone, more than 27,600 kilograms of DES were used in livestock feed lots. Unfortunately, we still know very little about the molecular mechanism by which DES affects reproductive tract development. To address this mechanism is important because many synthetic and naturally occurring chemicals we are currently exposed to also mimic estrogen and could affect the health of the next generation in a similar fashion as DES did. This proposal will dissect the genetic pathways affected by DES during female reproductive tract (FRT) development. Our preliminary studies show that several developmental control genes are regulated by DES during critical period of uterine cytodifferentiation. In particular, homeodomain protein Msx2 appears crucial in counteracting the effect of DES on the devleoping FRT as DES induces very dramatic reproductive patterning defects in Msx2 mutants, resulted from altered molecular changes in these mutants. The present grant will continue to test the hypothesis that DES can change uterine epithelial cell fate by affecting genetic pathways governing uterine cytodifferentiation. In aim 1, the role of Msx2 in uterine and vaginal development and DES-induced FRT malformations will be rigorously examined. In aim II, we will use gain and loss of function approaches in vivo to examine whether Klf4 is both necessary and sufficient for DES-induced uterine metaplasia. Finally in aim III, we will test the hypothesis that DES affects luminal epithelial architecture through modulation of the Wnt pathway. By completing these studies, we should be able to build genetic pathways controlling uterine development and address how DES can cause abnormal FRT patterning through modulation of these pathways. Our long term goal is to use mouse as a model to study reproductive tract development and how exogenous factors can influence this process.