中文摘要：

E-钙粘素是在胚胎发育中最早表达的分子之一，它可以与Catenin家族成员形成钙粘素／Catenin复合物参与多种细胞功能，对于胚胎植入和胎盘发生具有重要作用．通过RT-PCR、免疫组织化学、细胞粘附分析等方法，在人正常妊娠和输卵管妊娠母胎界面上，发现E-钙粘素主要定位于绒毛细胞滋养层细胞和滋养层细胞柱，从滋养层细胞柱近端向远端，其蛋白质水平逐渐降低．正常胎盘组织中E-钙粘素水平在妊娠早期较高，妊娠中期直至分娩期均维持低水平．在体外培养的人正常胎盘细胞滋养层细胞系（NPC细胞）中，转化生长因子β（TGFβ1）显著上调E-钙粘素蛋白和mRNA的表达，并呈现时间和剂量依赖性，同时，TGFβ1促进NPC细胞之间的粘附．上述结果表明，胎盘中存在E-钙粘素的旁分泌调节机制，E-钙粘素可通过调节滋养层细胞粘附而参与细胞侵润的有节制调控．

英文摘要：

E-cadherin was one of the early expressed genes during embryo development. The intact form of E-cadherin can link to cytoskeleton via β catenin, and the complex plays essential roles in cell adhesion. Evidences indicated the essential functions of E-cadherin in processes of embryoic implantation and placentation. Immunohistochemistry and RT-PCR were used to identify the localization of E-cadherin in human placenta. It was found that E-cadherin was expressed mainly in villous cytotrophoblasts and trophoblast column, with the immunoreactivity decreased obviously in distal trophoblast column. Temporally, the mRNA level of E-cadherin in placenta was the highest at gestaional week 6, and began to be down-regulated from week 8 on, reaching a nadir at week 9. However, the mRNA expression was up-regulated in placenta at week 26 and full-term. In human normal placenta origin cytotrophoblast cell line （NPC）, the mRNA and protein expressions of E-cadherin was significantly stimulated by TGFβ1 in dose- and time-dependent manners. Meanwhile, the cell-cell adhesion of NPC cells was promoted by TGFβ1. All these data indicated that there exists paracrine regulation of E-cadherin in human placenta, and E-cadherin may be involved in regulating trophoblast cell behaviors, likely inhibiting cell invasion through facilitating cell-cell adhesion.