CDX1影响滋养细胞侵袭能力的机制分析

CDX1, a gene which expressed significant hypermethylation in the placenta with preeclampsia, was found by us via the process of filtering by high-density methlation microarray . Previous study found that CDX1, located in placental tissue and primary trophoblast cells during preelampsia, demonstrated significant hypermethlation, decreased protein expression and the inhibition of PI3K-Akt pathway. The fact that over-expression of CDX1 can enhance the invasiveness of trophoblast cells and activate PI3K-Akt pathway suggested that CDX1 protein expression was decreased and PI3K-Akt pathway was inhibited during preeclampsia, which resulted in the decline of trophoblast cells' invasiveness. This study will select clinical tissue samples of diseases related to abnormality of trophoblast's invasiveness to assess the general relevance of CDX1 expression changes and trophoblast's invasiveness. We will also observe the changes of trophoblast's invasiveness and PI3K-Akt pathway when CDX1 over-expresses or silences. Then we will point to the intervention of PI3K-Akt pathway to demonstrate the role of this pathway in CDX1's effecting changes of trophoblast's invasivess by application of the pathway inhibitors, agonists and overexpressed Akt. The effect of CDX1 on trophoblasts's invasiveness and its mechanism have not been reported, so this study is of certain orginality and will provide new clues and intervention target for early prevention and treatment of diseases related to changes of trophoblast's invasiveness.

CDX1是我们应用高密度甲基化芯片筛选发现的、在子痫前期患者胎盘组织中显著超甲基化的基因。前期发现：子痫前期胎盘组织及原代滋养细胞中CDX1显著超甲基化、蛋白表达下调，PI3K-Akt通路抑制；CDX1过表达可致滋养细胞侵袭力增强，PI3K-Akt通路激活，提示子痫前期时CDX1蛋白表达下调、抑制PI3K-Akt通路、致滋养细胞侵袭力下降。本研究拟：选取滋养细胞侵袭力异常相关疾病的临床组织标本，评估CDX1表达变化与滋养细胞侵袭力改变的普遍相关性；观察CDX1过表达、表达沉默时，滋养细胞侵袭力及PI3K-Akt通路的变化；以PI3K-Akt通路为干预点，应用此通路抑制剂、激动剂和过表达Akt，论证此通路在CDX1致滋养细胞侵袭力变化中的作用。CDX1致滋养细胞侵袭力改变及其机制未见报道，因此本研究具有源头创新性，可为滋养细胞侵袭力改变所致相关疾病的早期防治提供新线索和干预靶标。

子痫前期是妊娠期特有的疾病，是孕产妇和围生儿患病率、死亡率的重要因素，严重影响母婴健康。然而子痫前期的病因及发病机制非常复杂，至今仍未阐明。目前认为：滋养细胞侵袭能力下降，导致胎盘着床过浅及胎盘着床部位子宫螺旋动脉重铸障碍，是子痫前期发病的关键因素，因此揭示滋养细胞侵袭能力下降的原因及机制对研究子痫前期的病因学有重要意义。.CDX1基因是我们通过高密度甲基化芯片筛选，并用亚硫酸氢盐反转测序法（BSP法）进行验证，筛选到的一个在正常与子痫前期患者胎盘样本中差异表达的基因。本项目以CDX1过表达在HTR-8/SVneo滋养层细胞中进行体外研究，评价CDX1对滋养细胞的侵袭力的影响，并采用Transwell侵袭模型检测滋养细胞的侵袭能力，real-time PCR检测CDX1 mRNA表达水平、Western-Blot法检测CDX1，MMP-9与TIMP-1蛋白的表达量及PI3K-Akt信号通路的变化，分析CDX1基因对滋养细胞侵袭力的影响，论证CDX1在子痫前期中的作用及致病的可能机制。.研究发现：1）子痫前期胎盘组织及原代滋养细胞中CDX1显著超甲基化、蛋白表达下调，PI3K-Akt通路抑制；2）CDX1过表达可致滋养细胞侵袭力增强， MMP-9表达上升、TIMP-1表达下降，PI3K-Akt通路激活；CDX1表达沉默时滋养细胞侵袭力无变化， MMP-9、TIMP-1表达无明显变化，PI3K-Akt通路无变化。并且本研究进一步以PI3K-Akt信号通路为切入点，深入探讨异常超甲基化使CDX1表达下降、致滋养细胞侵袭力下降的分子机制。由于目前CDX1致滋养细胞侵袭力改变及其机制、CDX1超甲基化的临床意义均未见文献报道，因此本研究具有源头创新性，可为子痫前期早期防治提供新线索和干预靶标。.本课题与原科研设计完全一致。通过研究，已完成了计划任务及预期研究目标，较充分地获得了CDX1 影响滋养细胞侵袭能力的证据，系统揭示了CDX1 影响滋养细胞侵袭能力的机制，阐明了滋养细胞侵袭能力下降在子痫前期发病中的作用，获得了较多有用的实验依据，为后续研究提供了新线索、新经验、新依据。.本项目完成了研究计划，取得了一系列的创新成果，共完成高质量论文9篇，其中SCI论文6篇。