环状RNA circ_0010419靶向miR-18a-5p调控滋养细胞侵袭力在子痫前期发病中的作用及机制研究

Preeclampsia is still a leading cause of maternal and perinatal morbidity and mortality. The exact pathogenesis of preeclampsia is still unknown, but it has been widely accepted that superficial trophoblast invasion plays a crucial role in the development of preeclampsia..Circular RNAs are a special type of non–coding RNA in mammalian cells that interact closely with miRNAs. In the previous study, we found that lots of circRNAs were differentially expressed in PE placental tissues versus their controls by high throughput sequencing. The expression levels of circRNA_0010419 was validated as significantly up-regulated in PE group compared with the controls. CircRNA_0010419 was found to inhibit trophoblast invasion by over-expression approaches. We found that circRNA_0010419 shares miRNA response elements of miR-18a-5p by bioinformatic analysis, which was reported to inhibit invasion and promotes apoptosis of human trophoblast cells. Thus we aim to investigate the role of circRNA_0010419/ miR-18a-5p in regulating trophoblast invasion, to confirm the relationship between circRNA_0010419 and miR-18a-5p, to investigate the effect of circRNA_0010419/ miR-18a-5p in the pathology of preeclampsia，to determine the valve of circRNA_0010419 for the prediction of pre-eclampsia. The ultimate goal is to find effective treatment for preeclampsia.

子痫前期严重危害母婴健康,绒毛外滋养细胞侵袭力下降在其发病中发挥重要作用。环状 RNA具有内源性竞争miRNA、调控基因表达等作用。本课题组前期发现子痫前期患者胎盘组织中circRNA_0010419表达升高；细胞实验：上调circRNA_0010419表达后，滋养细胞侵袭力下降；生物信息学分析：circRNA_0010419存在miR-18a-5p应答元件。据此，申请者提出“circRNA_0010419 靶向miR-18a-5p调控滋养细胞侵袭力，参与子痫前期发病”的假说。本项目拟通过上调/下调circRNA_0010419后验证滋养细胞侵袭力变化，明确其是否发挥miR-18a-5p分子“海绵”作用；借助子痫前期大鼠模型探讨circRNA_0010419在子痫前期发病中的作用；利用临床资源，验证circRNA_0010419在子痫前期发病中的预测价值，以期为子痫前期诊疗提供新思路。

子痫前期是一种以高血压和蛋白尿为特点，严重危害母婴健康的妊娠期特发性疾病，发病机制至今不明。滋养细胞侵蚀力下降在子痫前期的发病中发挥重要作用，前期研究发现circRNA_0010419在子痫前期患者和正常孕妇的胎盘组织中存在表达差异，circRNA_0010419可调控滋养细胞侵袭力，但其具体作用机制以及其在子痫前期发病中的预测价值尚不清楚。本项目通过生物信息学分析、qRT-PCR实验、Western blot实验、CCK8实验、RIP实验、Pull down实验、双荧光报告系统等实验，研究发现与正常孕妇相比，circRNA_0010419在重度子痫前期患者的胎盘组织中高表达，miR-18a-5p在重度子痫前期患者的胎盘组织中低表达。circRNA_0010419可通过“海绵吸附”miR-18a-5p，与正常孕妇相比，子痫前期患者的胎盘组织中miR-18a-5p表达下调，miR-18a-5p可靶向调控滋养细胞中FBP1基因的表达，circRNA_0010419/miR-18a-5p/FBP1在调控滋养细胞的增殖、侵袭和迁移中发挥重要作用，参与子痫前期的发病。通过前瞻性临床研究发现，子痫前期患者中孕期外周血中circRNA_0010419表达水平低于正常孕妇，但是差异并不具有统计学意义。此外，在本项目的支持下，我们扩充研究内容，探讨子痫前期的遗传发病机制以及miR-125b与滋养细胞凋亡的关系。结果发现APELA 基因5’-UTR区的两个突变与子痫前期的发病密切相关，并可调控APELA 基因的表达。miR-125b可以靶向MCL1基因诱导HTR-8/SVneo滋养细胞凋亡，在胎盘发育过程中发挥重要作用。总之，本项目多角度探讨子痫前期的发病机制，为子痫前期的诊疗提供了新思路。