多囊卵巢综合征（PCOS）女性子宫内膜质量下降及内膜病变比例高已经被证实，申请者前期研究报道miR-125b可以调节HCG日高孕酮女性子宫内膜容受性，但是miR-125b调节PCOS女性子宫内膜病理机制及其上游调控元件的作用机理仍不清楚。本项目借助已完成的PCOS女性子宫内膜circRNA芯片数据为基础，通过5个与miR-125b具有表达调控关系的circRNA分子的表达特征分析，明确circRNA分子与miR-125b的正/负调控关系，阐明其通过介导miR-125b影响增殖期子宫内膜功能的分子途径，确证circRNA——miR-125b调控单元在mRNA水平上的靶标分子，系统论证PCOS女性性激素紊乱诱导“circRNA —— miR-125b —— 靶基因”的级联调控机制。本研究成果可以为临床改善PCOS女性子宫内膜质量，预防子宫内膜病变提供理论基础。

It has been verified that the quality of endometrium is poor and its pathologic ratio is high in women with polycystic ovary syndrome(PCOS). In previous studies we reported that miR-125b can regulate endometrial receptivity targeting MMP26 in women with elevated progesterone on HCG priming day. Building on data of circRNA chip of endometrium with PCOS, we aim to demonstrate the mechanism of cascade regulation relationship among circRNA—miRNA-125b—targeting gene here in PCOS patients with sex hormone disorders systematically by analyzing five circRNAs which are associated with miR-125b and demonstrating their expression characteristics, clarifying the regulation relationship between circRNAs and miR-125b, thus confirming the potential molecular pathway of miR-125b effecting endometrium regulated by circRNAs, further ascertaining targeting molecules and signal pathways between the regulating element of circRNA—miR-125b in mRNA levels. This project can shed a new light on how to improve endometrium quality and provide a theoretical foundation for preventing endometrium disease by confirming the molecular mechanisms of miR-125b regulating endometrium in PCOS patients from the perspective of circRNA.