长链非编码RNA linc00284调控滋养细胞EMT过程参与子痫前期发病机制研究

Preeclampsia (PE) is associated closely with the increased maternal and perinatal mortality. Too shallow of trophoblast invasion and the failure of uterine spiral artery remodeling contribute importantly to the pathological mechanisms of PE. Epithelial-mesenchymal transition (EMT) process is proved to be a critical step in trophoblast cells obtaining invasive phenotype. Long non-coding RNAs (lncRNAs) have been confirmed to play regulatory role in cell invasion process with specific mechnisms . Our previous study have found a 60% decrease of lncRNA linc00284 in PE placentas than normal in our previous study. Then the in vitro experiments showed that trophoblast invasion was increased by overexpression of linc00284, probably through EMT. As a competitive endogenous RNA (ceRNA), lncRNA could regulate the expression of down-stream target genes by binding to micorRNA. And we verified a direct binding between linc00284 and miR-29b. Therefore, we speculate that the lower expression of linc00284 in PE results in a reduction of competitive binding of miR-29b while an increase of free miR-29b, which thereby inhibits its target gene IGF-1 expression. The inhibition of IGF-1 thus arrested trophoblastic EMT process with attenuation in trophoblast cell migration, invasion and the failure of spiral artery remodeling finally. We intend to reveal the epigenetic role of linc00284 in the pathogenesis of PE. We attempt to systematically clarify the role and related mechanisms of linc00284 in trophoblast invasion and remodeling of spiral artery. Wish to further enrich the etiology of PE, as well as to provide evidence for PE early clinical diagnosis and prevention in the future.

子痫前期（PE）是孕产妇和围产儿病死率升高的重要原因。滋养细胞侵袭过浅和子宫螺旋动脉重铸障碍是PE发病的重要病理机制，而上皮-间质转化（EMT）过程是滋养细胞获取侵袭表型的关键步骤。近来长链非编码RNA（lncRNA）调节细胞侵袭的上游机制不断被证实。课题组前期发现：PE胎盘中linc00284表达下调，其过表达可增强滋养细胞侵袭力，可能参与EMT调控。lncRNA可作为竞争性内源性RNA结合miRNA进而调控靶基因表达，进一步实验发现linc00284与miR-29b直接结合。据此提出假设：PE中下调的linc00284竞争性结合miR-29b减少，游离miR-29b增加使靶基因IGF-1表达受抑，导致滋养细胞EMT进程受阻，细胞侵袭能力下降、螺旋动脉重铸障碍。本研究拟系统阐释linc00284参与PE发病及其机制，进一步为PE病因学研究提供新的分子靶标，为临床早期预测及防治开辟新的思路

本课题旨在进一步明确长链非编码RNA linc00284与子痫前期（PE）滋养细胞侵袭及螺旋动脉重铸之间的关系。通过临床标本、细胞水平及在体实验三部分证明linc00284参与PE发病的具体作用机制：PE中下调的linc00284，使竞争性结合的miR-29b减少，抑制靶基因IGF-1表达，削弱滋养细胞侵袭及血管形成潜能，介导PE螺旋动脉重铸障碍。扩大样本量进一步在60例子痫前期孕妇胎盘组织中证实linc00284表达较正常组织显著下调。在滋养细胞中敲低linc00284的表达，表现出滋养细胞增殖减弱，细胞凋亡增加，迁移/侵袭能力明显下降，且脐静脉内皮细胞的血管形成能力削弱；双荧光素酶报告基因实验正式 linc00284与miR-29b 存在靶向结合，miR-29b与 IGF-1 的之间亦存在靶向调控关系；干预linc00284后滋养细胞 EMT相关标记分子明显改变，证明EMT过程受阻，从而累及细胞侵袭及螺旋动脉重铸过程。本研究系统阐释了linc00284参与PE发病及其机制，临床与基础有机结合，分别从体内、外水平探究 linc00284 调节 EMT 过程参与PE 螺旋动脉重铸过程的机制，进一步丰富了 PE 发病机制，为PE病因学研究提供新的分子靶标，为临床早期预测及防治开辟新的思路。