一种circRNA作为ceRNA参与C19MC中一类miRNA簇靶向MMP2调控子痫前期滋养细胞功能的机制研究

Dysfunction of trophoblastic cells is one important reason for Preeclampsia and the mechanisms have not been able to fully elucidated. We have found miR-515-3p and miR-520g-5p located in C19MC cluster are increased in placenta of PE. And the two miRNAs may target 3’UTR of MMP2 to participate in pathogenesis of PE. We also found that circ_MMP2 was decreased in placenta of PE, bioinformatic analysis showed that circ_MMP2 has binding sites sponged to miR-515-3p and miR-520g-5p. We will discuss circ_MMP2 could adsorb miR-515-3p and miR-520g-5p by ceRNA network thus change expression of MMP2, and impact the function of trophoblastic cells.

胎盘滋养细胞功能障碍是导致子痫前期的重要原因之一，对其机制一直未能完全阐明。申请者在前期工作中发现，C19MC miRNA基因簇成员miR-515-3p及miR-520g-5p在子痫病人胎盘中显著增加，这两个miRNA均可能靶向基质金属蛋白酶2参与子痫发病，同时还发现circ_MMP2在PE病人胎盘中表达降低，信息分析表明，circ_MMP2上有结合miR-515-3p和miR-520g-5p的位点。鉴于目前子痫前期中circRNA与miRNA的关联研究报道极少，且作用机制未明。本项目拟在此基础上，进一步探讨滋养细胞中circ_MMP2通过CeRNA的方式吸附miR-515-3p和miR-520g-5p，并改变自身来源基因MMP2表达进而影响滋养细胞功能这一信号通路。

胎盘是子痫前期发病的重要环节，而滋养层细胞是其行使功能的基础，因此滋养细胞功能障碍可能是子痫前期发病的重要因素。非编码RNA（ncRNAs）尤其环状RNA（circRNAs）可能也参与了子痫前期的发生发展，我们在子痫前期孕妇胎盘中发现hsa_circ_0039411表达水平显著降低的同时miR-515-3p和miR-520g-5p表达显著增高。本项目主要证明hsa_circ_0039411作为分子海绵可以竞争性结合miR-515-3p和miR-520g-5p从而参与子痫前期的发生发展。我们使用高通量RNA转录组测序和RT-PCR技术在子痫前期病人和正常孕妇的胎盘中筛选出hsa_circ_0039411等差异性circRNAs，同时荧光素酶报告实验和AGO免疫共沉淀实验发现miR-515-3p和miR-520g-5p与hsa_circ_0039411有结合关系。我们通过细胞实验阐明miR-515-3p和miR-520g-5p对滋养细胞MMP2基因的调控作用，明确hsa_circ_0039411调控miR-515-3p和miR-520g-5p影响滋养细胞侵袭、迁移及凋亡的调控机制，证实hsa_circ_0039411对miR-515-3p和miR-520g-5p的分子海绵作用可以调控滋养细胞生物学行为，MMP2是其中重要的信号通路。我们的实验结果证实了hsa_circ_0039411可以作为分子海绵吸附miR-515-3p和miR-520g-5p调控MMP2的表达，影响滋养细胞功能从而参与子痫前期发病机制的假说，为子痫前期的诊断、治疗提供了新的靶点。