Modulation of the Receptive Endometrium by CG

描述（由申请人提供）：蜕膜化是灵长类动物和啮齿类动物成功建立妊娠的绝对必要过程。蜕膜过程与成纤维细胞向高度分泌的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。由于这种分化过程，蜕膜基质细胞获得独特的能力，以调节滋养层入侵，抵抗炎症和氧化损伤，并抑制局部母体免疫反应。然而，允许这些细胞启动其分化级联的早期事件尚未阐明。这些机制的理解是至关重要的，因为受损的蜕膜化与许多妇科恶性肿瘤的妇女与广泛的病因从不孕症到早期妊娠丢失。在之前的资助期间，我们证明了早期灵长类动物胚胎信号，绒毛膜促性腺激素（CG），加上孕酮，直接调节子宫内膜基因表达和改变子宫间质成纤维细胞的细胞骨架结构。这些细胞骨架的变化是必要的，以防止基质细胞在概念周期中发生凋亡，并允许在蜕膜转化过程中的细胞重组。我们的数据还首次表明，进化保守的Notch 1蛋白，这在细胞命运的决定中起着关键作用，在体内和体外子宫内膜间质细胞中的CG和孕酮的调节。Notch 1在蜕膜化过程中的重要性在转基因小鼠模型中是显而易见的，当Notch 1在子宫中被特异性消融时，该小鼠模型未能蜕膜化。基于这些研究，在本申请中提出了三个具体的目的，以阐明Notch 1在抑制基质细胞凋亡和启动蜕膜化过程中的作用。在具体目标1，我们将测试的假设，即诱导和激活Notch 1的CG和孕酮是需要诱导子宫间质成纤维细胞平滑肌肌动蛋白（SMA）。拟议的研究将集中在基质成纤维细胞中Notch 1对SMA表达的转录调控，以及这是否反过来阻止细胞发生凋亡。具体目标2将检验Notch 1介导的FOXO 3a减少和Notch 1介导的IL-11增加是蜕膜化启动的必要先决条件的假设。FOXO 3a在蜕膜化过程中受到抑制，另一个Notch 1靶点IL-11是蜕膜化过程的早期启动子。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）。在特定目标3中，我们将使用我们已经产生的PRCre/+ Notch 1flox/flox双基因小鼠。该模型证明了一个显着的蜕膜化失败，并提供了一个体内模型，以确定蜕膜化反应所需的Notch 1的分子和细胞靶点。预计这些研究将提供有关蜕膜化过程的关键信息，并转化为Notch 1对蜕膜缺陷女性的治疗潜力。我们相信，更好地了解负责蜕膜化和植入的分子机制，将提高临床医生的能力，检测，诊断和治疗早期妊娠丢失。公共卫生相关性：了解支配蜕膜化的机制对成功建立妊娠至关重要。一些疾病如子宫内膜异位症和子宫内膜癌与蜕膜化受损有关。该研究计划将重点关注Notch 1在基质细胞分化中的作用。虽然涉及细胞命运和多种恶性肿瘤的发育调节，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，这些研究可能会提供深入了解新的治疗靶点蜕膜化失败。

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.