Hamster: A Unique Model for Studying Implantation

描述(申请人提供)：每个物种都制定了自己的植入策略。利用跨物种异源基因芯片，我们发现C型利钠肽(CNP)可能是金黄地鼠着床的信号分子。金黄地鼠的着床类似于兔、猪、猴，最有可能的是人。CNP是利钠肽(NP)家族的第三个成员，该家族还包括心房性和脑源性NPs(ANP和BNP)。所有NPs都通过两种类型的鸟苷酸环化酶(GC)受体发挥作用，即GC-A和GC-B。CNP偏爱GC-B，而ANP和BNP偏爱GC-A。我们的初步结果表明，虽然CNP信号在金黄地鼠着床部位占优势，但ANP/BNP和CNP信号在小鼠和金黄地鼠着床部位都是活跃的。这些观察结果与CNP和ANP的子宫松弛特性、BNP对滋养层细胞的生长、BNP诱导着床以及GC-B基因缺失女性的不孕不育一起表明，NP信号强烈影响着着床过程。因此，我们提出了一个工作假说，即NP配体-受体信号影响着着床的几个生物学和临床重要方面：1)受孕子宫的肌张力，2)着床前胚泡-子宫的串扰，3)滋养细胞的附着、生长和侵袭，以及4)子宫基质细胞的蜕膜化。因此，我们的具体目标是在仓鼠身上研究：1)胚泡在着床前和着床时对子宫的影响；2)NPs在着床前和着床期间调节子宫收缩的功能；以及3)NP配体-受体信号在着床起始和蜕膜形成中的作用。我们将使用多种实验方法，包括qPCR、Northern和原位杂交、免疫组织化学、在体腺病毒载体驱动的基因抑制、体外子宫收缩研究等来实现我们的目标。破译植入所需的调节事件将提供对植入缺陷和女性不孕的潜在原因的洞察。因此，这些在仓鼠身上进行的研究表明，孕酮依赖的植入可能会为开发诊断和治疗工具提供有用的信息，这些工具可以用于检测、预防和治疗女性生殖障碍，并改进辅助生殖和避孕技术。 公共卫生相关性：该提案将解决利钠肽配体-受体信号在调节早孕事件中的作用。子宫缺陷会导致女性不孕不育和妊娠丢失。这项研究将对子宫容受性/着床/蜕膜形成的分子机制提供更深入的了解，并有助于设计临床治疗方法来识别、治疗和预防妇女的生殖问题。

DESCRIPTION (provided by applicant): Each species has developed its own strategy for implantation. Using a cross- species heterologous microarray we identified C-type natriuretic peptide (CNP) as a possible implantation signaling molecule in hamsters which exhibit progesterone- dependent implantation similar to rabbits, pigs, monkeys and most likely in humans. CNP is the third member of the natriuretic peptide (NP) family which also includes atrial- and brain-NPs (ANP and BNP). All NPs act via two types of guanylyl cyclase (GC) receptors, GC-A and GC-B. CNP has more preference for GC-B, while ANP and BNP prefer GC-A. Our preliminary results show that while CNP signaling predominates at the implantation site of hamsters, both ANP/BNP and CNP signalings are active at the implantation sites of both mice and hamsters. These observations together with uterine relaxation properties of CNP and ANP, trophoblast outgrowth by BNP, induction of implantation by BNP, and infertility in GC-B null females suggest that NP signaling strongly influences the implantation process. Thus, we formulated a working hypothesis that NP ligand-receptor signaling influences several biologically and clinically important aspects of implantation: 1) muscular tone of the receptive uterus, 2) blastocyst-uterine cross talk prior to implantation, 3) trophoblast attachment, outgrowth and invasion, and 4) uterine stromal cell decidualization. Therefore, our Specific Aims are to study in hamsters: 1) influence of the blastocyst on the uterus prior to and at the time of implantation; 2) functions of NPs in regulation of uterine contractility prior to and during the time of implantation; and 3) the role of NP ligand-receptor signaling in initiation of implantation and decidualization. We will use multiple experimental approaches including qPCR, Northern and in situ hybridization, immunohistochemistry, in vivo adenoviral vector-driven gene inhibition, in vitro uterine contraction studies, and others to accomplish our goals. Deciphering the regulatory events required for implantation will provide insight into the potential causes of defects in implantation and infertility in women. Thus, these studies in hamsters that show progesterone-dependent implantation may provide useful information in the development of diagnostic and therapeutic tools that can be used in detection, prevention and treatment of female reproductive disorders, and improved technologies for assisted reproduction and contraception. PUBLIC HEALTH RELEVANCE: This proposal will address the role of natriuretic peptide ligand-reeptor signaling in the regulation of early pregnancy events. Defects in the uterus can cause infertility and pregnancy loss in women. This research will provide deeper insight into the molecular mechanisms underlying establishment of uterine receptivity/implantation/decidualization, and help to design clinical therapies to identify, treat and prevent reproductive problems in women.