LncRNA-ATB调控滋养细胞生物学行为在重度子痫前期中的作用及机制研究

Severe preeclampsia is one of leading causes of maternal and perinatal mortality and morbidity worldwide. Although it is generally accepted inadequate trophoblast invasion and aberrant spiral arterial remodeling is the critical cause of the disease，the exact pathogenesis of that process is urgently needed to be further clarified. LncRNA-ATB is verified to be aberrantly expressed in many cancers and promotes the invasion-metastasis and proliferation cascades, but little is known of lncRNA-ATB's role in severe preeclampsia since trophoblast cells and malignant cells share many similar characteristics including extensive proliferation, migration, invasion abilities. In our preliminary studies, it is first demonstrated that lncRNA-ATB was intense stained in the trophoblast of the placenta and it was significantly decreased in the placenta samples of severe preeclampsia. Moreover, further research suggested that lncRNA-ATB could affect the proliferation, migration, invasion and tube formation abilities of HTR-8/SVneo cells line probably by regulating the expression of the major biomarkers (such as E-cadherin, N-cadherin) involved in migration and invasion processes, indicating the aberrant placenta lncRNA-ATB expression might be the key mechanism of the severe preeclampsia pathogenesis. In the present project, in vitro cell-based experiments, the 3D remodeling model, and an animal model are employed to investigate the effect of lncRNA-ATB on the trophoblast invasion and spiral arterial remodeling, and then illuminate the key proteins or molecules interplayed with lncRNA-ATB. Further, a case-control study will be conducted to observe the relationship between placenta lncRNA-ATB level and the key molecules involved in the lncRNA-ATB pathway. Overall, the results of the present project will explicit the exact effect and mechanism of lncRNA-ATB on the severe preeclampsia via affecting the trophoblast behaviors and enrich the pathogenesis theory of severe preeclampsia, providing more evidence on developing a new target for prevention and management of this disease.

重度子痫前期严重威胁母儿健康，目前公认滋养细胞侵润过浅和螺旋动脉重铸障碍是其发病的关键，但机制亟待阐明。课题组前期研究首次发现lncRNA-ATB主要在胎盘滋养细胞表达，更重要的是lncRNA-ATB的表达在重度子痫前期者胎盘显著降低，而且发现其可调控滋养细胞株增殖、迁移、侵袭、血管形成及迁移侵袭中重要标记分子的表达，强烈提示胎盘lncRNA-ATB的异常表达可能是重度子痫前期发病的关键机制。本项目拟通过体外细胞学、3D重铸模型及动物体内模型探讨lncRNA-ATB对滋养细胞侵润及对螺旋动脉重铸的影响，探寻lncRNA-ATB影响细胞生物学行为的关键分子及机制，在此基础上进一步研究重度子痫前期者胎盘lncRNA-ATB表达与其作用通路中关键分子的相关性，揭示lncRNA-ATB通过调控滋养细胞生物学行为在重度子痫前期中的作用及机制，不仅将丰富和完善该病的发病机制研究，也为其防治提供新思路。

重度子痫前期严重威胁母儿健康，目前公认滋养细胞侵润过浅和螺旋动脉重铸障碍是其发病的关键，但机制亟待阐明。本项目在前期研究的基础上，从临床样本、体外细胞学和体内动物实验等方面探索lncRNA-ATB对滋养细胞生物学行为的作用和关键分子及机制。研究发现，通过体外构建3D重铸模型模拟体内螺旋动脉重铸过程，证实敲低lncRNA-ATB表达可抑制滋养细胞替换内皮细胞的能力；数据库预测并验证miR-651-3p为lncRNA-ATB的竞争性内源RNA，二者表达呈负相关，挽救实验确证lncRNA-ATB通过调控miR-651-3p的表达影响3D重铸模型；通过数据库预测并验证YY1为miR-651-3p的靶基因，YY1在重度子痫前期胎盘中表达下降，并与miR-651-3p的表达呈负相关，挽救实验证实miR-651-3p通过调节YY1的表达对3D重铸模型产生影响。通过pull-down和RIP实验发现PABPC1与lncRNA-ATB直接结合，重度子痫前期患者胎盘中lncRNA-ATB和PABPC1均呈低表达，且二者具有正相关，敲低PABPC1表达可抑制滋养细胞的增殖、迁移、侵袭及成管能力；通过查阅文献及利用STRING在线数据库和免疫共沉淀实验鉴定PABPC1和MDM2的相互作用，证实PABPC1敲低抑制滋养细胞的生物学行为，在重度子痫前期胎盘中PABPC1与MDM2的表达呈正相关，MDM2敲低也可抑制滋养细胞的生物学行为；进一步验证PABPC1和MDM2之间的相互作用通过p53实现；过表达及敲低lncRNA-ATB的HTR8/SVneo细胞均未能侵入子宫壁，或是由于HTR8/SVneo细胞具有时空局限性及螺旋动脉重铸为多细胞多因子相互作用的过程。综上，lncRNA-ATB/miR-651-3p/ YY1通路不仅影响螺旋动脉重铸障碍过程，同时lncRNA-ATB/PABPC1可能通过p53-MDM2通路调控滋养细胞的生物学行为，从而在重度子痫前期的发病机制中发挥重要作用。本项目的结果丰富和完善了lncRNA-ATB调控螺旋动脉重铸及影响滋养细胞生物学行为的机制，为进一步探索子痫前期的发病机制提供了详实的实验依据，具有重要的科学意义。