Cellular and Molecular Aspects of Implantation

描述(申请人提供)：植入后蜕膜的形成被认为是保护胚胎免受母体侮辱的屏障。因此，植入缺陷和子宫蜕膜化可能是早期妊娠丢失的原因。鉴定胚胎细胞类型(S)和胚胎因子(S)用于着床和蜕膜形成将是提高繁殖力的一项重大成果。紧密连接(TJ)形成了限制细胞旁通透性的屏障，仅存在于上皮细胞中，而不存在于基质中。我们首次注意到，在妊娠第6天，胚泡周围的初级蜕膜区(PDZ)的基质细胞表达TJ及其相关蛋白occludin、claudin-1、zonula occludens-1(ZO-1)和ZO-2，而次级蜕膜区(SDZ)没有表达。我们的初步结果表明，胚泡的滋养层(Tr)，而不是内细胞团(ICM)，通过在PDZ中正确表达ZO-1而诱导着床和蜕膜化反应。我们还提供了证据表明，胚泡产生的肝素结合-表皮生长因子样生长因子(HB-EGF)对PDZ的着床、蜕膜形成和ZO-1表达是重要的。这些观察结果以及大分子染料对静脉注射后正常胚泡诱导的PDZ的通过的限制，而不是人工诱导的蜕膜形成，表明胚胎HB-EGF影响着床、PDZ的形成和PDZ内TJ的发生，从而产生一种保护胚胎的无血管通透性屏障。因此，我们的具体目标是在小鼠模型中确定：1)Tr在着床和PDZ形成中的影响，2)胚胎HB-EGF在着床和PDZ形成中的影响，3)HB-EGF在基质细胞向具有上皮特征的蜕膜细胞转化中的影响，以及4)PDZ作为母胎界面屏障的重要性。我们将使用多种实验方法，包括RT-PCR、Northern和原位杂交、免疫组织化学/免疫荧光、Western blotting、磷酸化、电子显微镜、胚胎培养和移植、细胞培养、体内/体外腺病毒载体驱动的基因传递等来实现我们的目标。这些结果将进一步加深我们对子宫保护机制(S)对早期妊娠着床胚胎保护的理解。

DESCRIPTION (provided by applicant): The formation of deciduum following implantation is considered to function as a protective barrier to the embryo from the maternal insults. Thus, defective implantation and uterine decidualization may account for early pregnancy losses. Identification of embryonic cell-type(s) and embryonic factor(s) for implantation and decidualization will be a major achievement to improve fecundity. The tight junction (TJ) that creates a barrier restricting the paracellular permeability is present only in cells of the epithelium, but not in the stroma. We noticed for the first time that the stromal cells of the primary decidual zone (PDZ) surrounding the implanting blastocyst, but not the secondary decidual zone (SDZ), on day 6 of pregnancy express the TJ and its associated proteins, occludin, claudin-1, and zonula occludens-1 (ZO-1) and ZO-2. Our preliminary results show that the trophoblast (Tr), but not the inner cell mass (ICM), of the blastocyst induces implantation and decidualization reactions with correct expression of ZO-1 in the PDZ. We also provide evidence here that heparin binding-epidermal growth factor-like growth factor (HB-EGF) produced by the blastocyst is important for implantation, decidualization, and ZO-1 expression in the PDZ. These observations together with the restriction of passage of macromolecular dye to the PDZ induced by normal blastocysts after intravenous administration, but not by artificially induced decidualization, suggest that the embryonic HB-EGF influences implantation, the PDZ formation, and genesis of the TJ in the PDZ which creates an avascular permeability barrier to protect the embryo. Therefore, our specific aims are to determine in a murine model: 1) Influence of the Tr in implantation and the PDZ formation, 2) Influence of embryonic HB-EGF in implantation and the PDZ formation, 3) Influence of HB-EGF in the transformation of stromal cells to decidual cells with epithelial characteristics, and 4) The importance of the PDZ as a barrier at the maternal-fetal interface. We will use multiple experimental approaches including RT-PCR, Northern and in situ hybridizations, immunohistochemistry/ immunofluorescence, Western blotting, phosphorylation, electron microscopy, embryo culture and transfer, cell culture, in vivo/in vitro adenoviral vector-driven gene delivery, and others to accomplish our goals. These results will further our understanding regarding uterine protective mechanism(s) to the safeguard of the implanting embryo during early pregnancy.