Uterine Vascular Remodeling during Pregnancy

描述（由申请人提供）：我们的实验室最近鉴定了一种新型鼠G蛋白偶联受体（GPCR），其响应于植入胚胎而在蜕膜化基质隔室中上调（7倍）。RT-PCR和原位杂交表明，新的GPCR是在时间和空间上限制在其表达模式的子宫间质室在怀孕期间，并没有在其他组织/器官中表达。使用人类蜕膜化基质细胞的研究表明，在人类蜕膜化过程中表达了功能对应物。因此，拟议的研究可能会对人类怀孕产生影响。同样，已证实妊娠早期子宫内膜中的肾素（一种通过血管紧张素原的蛋白水解裂解产生活性血液动力学肽的酶）上调。我们的假设是，孤儿GPCR是正常妊娠所必需的功能，这种新的受体介导血管紧张素-（1-7）诱导的血管舒张在母胎界面。在具体目标1中，我们建议在插入突变研究中证明受体的功能要求，其中cre重组酶插入受体基因位点。将特别关注子宫血管动力学和前列腺素的生产在怀孕早期。产生GPCR-cre小鼠系的一个重要方面是，由于蜕膜化子宫的受体的表达受限，小鼠可以在未来的实验中用作急需的研究工具，以使用Cre/LoxP技术研究被认为对子宫蜕膜化重要的其他基因。在具体目标2中，我们将测试GPCR启动子驱动转基因表达的功能。该研究项目的成功完成将对受体信号传导领域产生广泛的应用，并将促进我们对母胚相互作用的理解。

DESCRIPTION (provided by applicant): Our laboratory recently identified a novel murine G-protein coupled receptor (GPCR) that becomes up- regulated (7-fold) in the decidualizing stromal compartment in response to the implanting embryo. RT-PCR and in situ hybridization reveal that the novel GPCR is temporally and spatially restricted in its expression pattern to the stromal compartment of the uterus during pregnancy and is not expressed in other tissues/organs. Studies using human decidualized stromal cells suggest that a functional counterpart is expressed during human decidualization. The proposed studies will therefore have likely implications for human pregnancy. Likewise, it was established that renin, an enzyme that generates active hemodynamic peptides through proteolytic cleavage of angiotensinogen, is up-regulated in the endometrium during early gestation. Our hypothesis is that the orphaned GPCR is functionally required for normal pregnancy, and that this novel receptor serves to mediate angiotensin-(1-7)-induced vasodilation at the maternal-embryo interface. In Specific Aim 1 we propose to demonstrate the functional requirement of the receptor in insertional mutagenesis studies in which cre recombinase is inserted into the receptor gene locus. Particular focus will be given to uterine vascular dynamics and prostaglandin production during early pregnancy. One important aspect of generating the GPCR-cre mouse line is that, due to the restricted expression of the receptor to the decidualizing uterus, the mouse can be used in future experiments as a much needed research tool to study other genes thought to be important for uterine decidualization using Cre/LoxP technology. In Specific Aim 2, we will test the functionality of the GPCR promoter to drive transgene expression. Findings derived from the successful completion of this research project will have broad application to the field of receptor signaling and will advance our understanding of maternal-embryo interactions.