Interaction between blastocyst and Uterine endometrium

描述（由申请人提供）：早孕是所有哺乳动物的一个特征，在女性中尤其高。这是一个重大的公共卫生问题。超过50%的正常怀孕在胚胎附着在子宫并开始植入的时期失败。其中的原因是胚胎发育异常，从滋养外胚层（胎盘的前体）发出的信号较弱或较晚，以及母体子宫准备不足。在这里，我们将从两个方面来研究妊娠早期的孕母关系。第一个（目标1）是确定转录因子Cdx2在滋养外胚层分化和功能分化中的作用。目的1A是证实Cdx2在营养外胚层信号分子干扰素-tau （IFN-T）和其他特征性上调基因的转录控制中起关键作用。Aim 1B将验证Cdx2在指导小鼠和牛胚胎的滋养外胚层出现和维持极化上皮中所必需的假设。Aim 1C将证实Cdx2是早在2细胞发育阶段推定的滋养外胚层的标记物的初步研究。我们还将确定它是否是牛胚胎中细胞命运的类似标记。该项目的目标2是确定Sin1的功能，Sin1是一种新发现的蛋白，与IFN受体亚基IFNAR2的胞质结构域羧基端相关。我们假设母体对妊娠的识别涉及局部炎症反应和着床部位母体子宫内膜应激途径的调节，并且Sin1将IFN反应途径与信号转导途径联系起来，包括应激激活蛋白激酶（SAPK）途径。目的2A是通过使用酵母双杂交筛选来确定子宫内膜信号中Sin1的伴侣。Aim 2B将验证当IFN-T结合到子宫上皮细胞表面时，Sin 1会被募集，这一事件会导致应激激活信号转导通路活性的变化。Aim 2C将检查IFN-T与细胞结合后是否存在Sin1的细胞移位。Aim 2D将尝试通过RNAi敲低Sin1的表达，并通过使用这种方法，确定Sin1是否在I型IFN对哺乳动物细胞的一些不同（多效性）作用中发挥作用。Aim 2E将探讨Sin1蛋白不同结构域的过表达是否会干扰正常的Sin1功能。目的2F是创建Sin1缺失小鼠，以便更全面地了解Sin1在整个动物以及子宫内膜中的功能。这些研究预计将为妊娠早期的两个关键事件提供信息，即早期胎盘的形成和母体对附着在子宫壁上的微小胚胎的即时反应。

DESCRIPTION (provided by applicant): Early pregnancy loss is a feature of all mammals and is particularly high in women. It is a major public health concern. More than 50% of normally conceived pregnancies fail in the period at about the time the embryo attaches to the uterus and begins to implant. Among the causes are developmental abnormalities of the embryo, weak or late signaling from the trophectoderm (the precursor of the placenta) and an ill- prepared maternal uterus. Here we shall study two aspects of conceptus-maternal relationship in early pregnancy. The first (goal 1) is to define the role of the transcription factor Cdx2 in trophectoderm specification and functional differentiation. Aim 1A is to confirm that Cdx2 plays a key role in the transcriptional control of the genes for the signaling molecule interferon-tau (IFN-T) and other genes characteristically up-regulated in trophectoderm. Aim 1B will test the hypothesis that Cdx2 is necessary in directing trophectoderm emergence in murine and bovine embryos and in maintaining a polarized epithelium. Aim 1C will confirm preliminary studies that Cdx2 is a marker of presumptive trophectoderm as early as the 2-cell stage of development. We shall also determine whether it is an analogous marker of cell fate in the bovine embryo. Goal 2 of this project is to define the function of Sin1, a newly discovered protein that associates with carboxyl end of the cytoplasmic domain of the IFN receptor subunit, IFNAR2. We hypothesize that maternal recognition of pregnancy involves a localized inflammatory response and the modulation of stress pathways in maternal endometrium at the site of implantation, and that Sin1 links the IFN response pathway to signal transduction pathways, including the stress-activated protein kinase (SAPK) pathway. Aim 2A is to define partners for Sin1 in endometrial signaling through the use of a yeast two-hybrid screen. Aim 2B will test the hypothesis that when IFN-T binds to the cell surface of uterine epithelial cells Sin 1 will be recruited, and this event will precede changes in the activities of stress-activated signal transduction pathways. Aim 2C will examine whether there is cellular relocation of Sin1 following IFN-T binding to the cell. Aim 2D will attempt to knock down Sin1 expression by RNAi and, by using this approach, determine whether Sin1 plays a role in some of the varied (pleiotropic) actions of type I IFN on mammalian cells. Aim 2E will explore whether the over-expression of different domains of the Sin1 protein can interfere with normal Sin1 function. Aim 2F is to create Sin1 null mice in order to gain a more complete insight into Sin1 function in the whole animal as well as in uterine endometrium. Together these studies are expected to provide information on two key events in early pregnancy, the formation of an early placenta and immediate maternal responses to the presence of a tiny embryo attaching to her uterine wall.