Modulation of the Receptive Endometrium by CG

描述(由申请人提供)：蜕膜化是灵长类和啮齿动物成功怀孕的一个绝对必要的过程。蜕膜过程与成纤维细胞向高度分泌上皮样细胞的形态转化以及子宫内膜间质细胞的生化重编程有关。作为这种分化过程的结果，蜕膜基质细胞获得了独特的能力来调节滋养层细胞的侵袭，抵抗炎症和氧化侮辱，并抑制局部的母体免疫反应。然而，允许这些细胞启动其分化级联的早期事件尚未阐明。对这些机制的理解是至关重要的，因为蜕膜功能受损与许多妇科恶性肿瘤有关，这些疾病的病因从不孕到早孕都有。在之前的资助期间，我们证明了灵长类早期胚胎信号绒毛膜促性腺激素(CG)与孕酮结合，直接调节子宫内膜基因的表达，并改变子宫基质成纤维细胞的细胞骨架结构。这些细胞骨架的改变是必要的，以防止间质细胞在概念周期中发生凋亡，并允许在蜕膜转化期间进行细胞重组。我们的数据还首次证明了进化保守的Notch1蛋白在体内和体外子宫内膜间质细胞中受到CG和黄体酮的调节，Notch1蛋白在细胞命运决定中发挥关键作用。Notch1在蜕膜化过程中的重要性在一个转基因小鼠模型中很明显，当Notch1在子宫中被特定切除时，该模型无法蜕膜。在这些研究的基础上，提出了三个特定的目的来阐明Notch1在抑制基质细胞凋亡和启动蜕膜形成过程中的作用。在特定的目标1中，我们将检验这样一种假设，即在子宫基质成纤维细胞中，需要CG和孕酮诱导和激活Notch1来诱导平滑肌肌动蛋白(SMA)。拟议的研究将集中在Notch1对间质成纤维细胞中SMA表达的转录调控，以及这是否反过来阻止细胞发生凋亡。特殊目的2将验证这样的假设，即Notch1介导的FOXO3a减少和Notch1介导的IL-11增加是启动蜕膜化的必要前提。FOXO3a在蜕膜化过程中被抑制，另一种Notch1靶标IL-11是蜕膜化过程的早期启动者。在这两个目标中提出的研究将利用人子宫成纤维细胞(Huf细胞)。在具体目标3中，我们将使用我们生成的PRCre/+Notch1Flox/FLOX双基因小鼠。该模型显示了一个显著的蜕膜化失败，并提供了一个体内模型来确定蜕膜化反应所需的Notch1的分子和细胞靶点。预计这些研究将提供有关蜕膜形成过程的关键信息，并转化为Notch1对有蜕膜缺陷的妇女的治疗潜力。我们相信，更好地了解蜕膜形成和植入的分子机制将提高临床医生发现、诊断和治疗早期妊娠丢失的能力。与公共卫生相关：低估蜕膜形成的机制对成功确定妊娠至关重要。一些疾病，如子宫内膜异位症和子宫内膜癌，与蜕膜功能受损有关。该提案的研究将集中在Notch 1在基质细胞分化中的作用。尽管它参与了细胞命运和多种恶性肿瘤的发育调控，但其在子宫生物学中的生理作用从未被研究过。因此，鉴于其目前的临床潜力，这些研究可能为蜕膜失败的新治疗靶点提供洞察力。

DESCRIPTION (provided by applicant): Decidualization is an absolutely essential process for the successful establishment of pregnancy in primates and rodents. The decidual process is associated with a morphological transformation of fibroblast cells to highly secretory epitheloid-like cells coupled with a biochemical reprogramming of the endometrial stromal cells. As a consequence of this differentiation process, decidualized stromal cells acquire the unique ability to regulate trophoblast invasion, resist inflammatory and oxidative insults and dampen local maternal immune responses. However, the early events that permit these cells to initiate their differentiation cascade have yet to be elucidated. The understanding of these mechanisms is critical since impaired decidualization is associated with numerous gynecological malignancies in women with a broad range of etiologies from infertility to early pregnancy loss. During the previous funding period we demonstrated that the early primate embryonic signal, chorionic gonadotropin (CG), coupled with progesterone, directly modulates endometrial gene expression and alters the cytoskeletal architecture of uterine stromal fibroblasts. These cytoskeletal changes are necessary to prevent the stromal cells from undergoing apoptosis in a conceptual cycle and allow for cellular restructuring during decidual transformation. Our data also demonstrated for the first time that the evolutionary conserved Notch1 protein, which plays a critical role in cell fate decisions, is regulated by CG and progesterone in endometrial stromal cells in vivo and in vitro. The importance of Notch1 in the decidualization process was evident in a genetically modified mouse model that failed to decidualize when Notch1 was specifically ablated in the uterus. Based on these studies three specific aims are proposed in this application to elucidate the role of Notch1 in inhibiting stromal cell apoptosis and initiating the decidualization process. In Specific Aim 1 we will test the hypothesis that the induction and activation of Notch1 by CG and progesterone is required to induce -smooth muscle actin (SMA) in uterine stromal fibroblasts. The proposed studies will focus on the transcriptional regulation of SMA expression by Notch1 in stromal fibroblasts and whether this in turn prevents the cells from undergoing apoptosis. Specific Aim 2 will test the hypothesis that the Notch1 mediated decrease in FOXO3a and Notch1 mediated increase in IL-11 is a necessary prerequisite for the initiation of decidualization. FOXO3a is suppressed during decidualization and another Notch1 targert, IL-11, is an earlier initiator of the decidualization process. Studies proposed in these two aims will utilize human uterine fibroblast cells (HuF cells). In Specific Aim 3 we will use the PRCre/+Notch1flox/flox bigenic mouse mouse that we have generated. This model demonstrates a significant decidualization failure and provides an in vivo model to identify the molecular and cellular targets of Notch1 that are required for the decidualization response. It is anticipated that these studies will provide critical information on the decidualization process and translate to therapeutic potentials of Notch1 for women with decidual defects. We believe a better understanding of the molecular mechanisms responsible for decidualization and implantation will improve clinician's ability to detect, diagnose and treat early pregnancy loss. PUBLIC HEALTH RELEVANCE: Understating the mechanisms that govern decidualization is critical to the successful establishment of pregnancy. Several disease conditions such as endometriosis and endometrial cancer are associated with impaired decidualization. The proposal studies will focus on the role of Notch 1 in stromal cell differentiation. Although implicated in the developmental regulation of cell fate and multiple malignancies its physiological role in uterine biology has never been studied. Thus, given its current clinical potential these studies may provide insight into new therapeutic targets for decidualization failure.