ASPECTS OF UTERINE RECEPTIVITY FOR IMPLANTATION

着床前胚胎与囊胚的同步发育 子宫处于接受状态的阶段和准备是必不可少的。 做植入手术。胚泡着床的子宫容受性是 依赖时间和类固醇激素。在大鼠和小鼠中，子宫 感受性只在怀孕期间的一段有限的时间内发生， 假孕，或当动物被黄体酮(P4)和 雌激素(E)适量。在这些物种中，子宫敏感性是 分为中性阶段、接受阶段和非接受(难接受)阶段。 在怀孕或假孕的小鼠中，子宫只在 第4天(植入当天)，而到第5天(如在 通过胚胎移植假孕小鼠)，子宫变得难治性 并且对胚泡或创伤性刺激的存在没有反应 用于诱导着床或蜕膜细胞反应(DCR)。这个 当子宫只暴露于P4时，就达到了中性阶段。在……下面 这种情况下，虽然子宫可以进行一些DCR后 创伤后，它不会对胚泡的存在产生反应。P4- 如果准备好的小鼠子宫可以接受胚泡植入， 在P4刺激24-48小时后暴露于少量E。子宫 在注射E后24至36小时内变得难治，这 只要继续P4治疗，阶段就保持不变。虽然 子宫敏感性的不同阶段可以在实验中诱导 啮齿动物，适合这些阶段的细胞或分子标记还没有 但已被确认身份。几种生长因子的表达及其意义 围着床期子宫和胚胎中的受体 表明这些生长因子在调节胚胎发育过程中起重要作用。 植入过程中子宫的相互作用。需要检验的假设 这里表达的是转化生长因子-α(TGF-α) 在接受子宫的腔上皮中，顶端有一层膜-- 结合前体(原转化生长因子-α)可作为受性子宫的标志物 并与表达的表皮生长因子受体(EGF-R)相互作用 在胚泡滋养外胚层(Tr)的细胞表面顶端 在小鼠体内启动植入过程。我们的具体目标是 检测：(1)前转化生长因子-α在中性、感受性和 (2)EGF-R在子宫内膜异位症中的表达 中性、接受性和非接受性(难治性)子宫，以及在 延迟的和激活的囊胚；(3)囊胚状态的作用 受孕子宫内着床活动；以及(4)相互作用 子宫腔上皮原转化生长因子-α与囊胚EGF-R的关系这个 这些研究的结果将确定腔上皮细胞 ProTGF-α或Tr-EGF-R可作为子宫容受性的标志物 或胚泡的活动状态，以及是否前转化生长因子-α/EGF-R 信号传递对于植入很重要。Northern印迹，原位 采用杂交和RT-PCR方法检测转化生长因子-α和表皮生长因子受体 MRNAs、免疫组织化学、Western blotting和ELISA将用于 检测转化生长因子原-α和表皮生长因子受体蛋白。还将对EGF-R进行研究 ~(125)I-EGF的放射自显影结合和亲和交联。 原转化生长因子-α和EGF-R之间的相互作用将通过以下方式进行测试 EGF-R和磷脂酶c-γ的磷酸化。

Synchronized development of the preimplantation embryo to the blastocyst stage and preparation of the uterus to the receptive state are essential for implantation. Uterine receptivity for blastocyst implantation is time and steroid hormone dependent. In the rat and mouse, uterine receptivity occurs only for a limited period during pregnancy, pseudopregnancy, or when the animal is treated with progesterone (P4) and estrogen (E) appropriately. In these species, uterine sensitivity is divided into neutral, receptive, and non-receptive (refractory) phases. In the pregnant or pseudopregnant mouse, the uterus is receptive only on day 4 (the day of implantation), while by day 5 (as examined in the pseudopregnant mouse by embryo transfer), the uterus becomes refractory and fails to respond to the presence of blastocysts or traumatic stimuli for the induction of implantation or decidual cell reaction (DCR). The neutral phase is achieved when the uterus is exposed to P4 only. Under this condition, although the uterus can undergo some DCR after traumatization, it does not respond to the presence of a blastocyst. P4- primed mouse uterus can be receptive for blastocyst implantation if exposed to a small amount of E after 24-48 h of P4 priming. The uterus becomes refractory between 24 and 36 h after an injection of E, and this phase is maintained as long as P4 treatment is continued. Although various phases of uterine sensitivity can be induced experimentally in rodents, suitable cellular or molecular markers for these phases have not yet been identified. Expression of several growth factors and their receptors in the uterus and embryo during the periimplantation period suggests that these growth factors are important in mediating embryo- uterine interactions during implantation. The hypothesis to be tested herein is that transforming growth factor-alpha (TGF-alpha), expressed apically in the luminal epithelium of the receptive uterus as a membrane- bound precursor (proTGF-alpha), serves as a marker for receptive uterus and interacts with the epidermal growth factor receptor (EGF-R) expressed apically on the cell surface of the blastocyst trophectoderm (Tr) to initiate the process of implantation in the mouse. Our specific aims are to examine: (1) Expression of proTGF-alpha in the neutral, receptive and non-receptive (refractory) uterus; (2) Expression of EGF-R in the neutral, receptive and non-receptive (refractory) uterus, and in the delayed and activated blastocysts; (3) Role of blastocyst's states of activity in implantation in the receptive uterus; and (4) Interaction between luminal epithelial proTGF-alpha and blastocyst EGF-R. The results of these studies will establish whether luminal epithelial proTGF-alpha or Tr EGF-R can serve as a marker for uterine receptivity or blastocyst's states of activity, and whether proTGF-alpha/EGF-R signalling is important for implantation. Northern blotting, in situ hybridization and RT-PCR will be used to detect TGF-alpha and EGF-R mRNAs, immunohistochemistry, Western blotting and ELISA will be used to detect proTGF-alpha and EGF-R proteins. EGF-R will also be studied by autoradiographic binding of 125I-EGF and affinity cross-linking. Interaction between proTGF-alpha and EGF-R will be tested by phosphorylation of EGF-R and phospholipase c-gamma.