miR-509-3p与其靶向circRNA在PCOS排卵障碍中相互调控的机制研究

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women. Abnormal folliculogenesis is considered a common characteristic of PCOS. Our previous studies have proven that the expression of miR-509-3p was up-regulated in PCOS cumulus cells while its target gene MAP3K8 was down-regulated. miR-509-3p mediates the MAPK signalling pathway and reduced the ERK1/2 phosphorylation to regulate E2 production by targeting MAP3K8. Excessive oestrogen will restrain the synthesis of FSH and lead to the occurrence of anovulation in PCOS. How was over-expressed miR-509-3p in PCOS cumulus cells regulated? Recently, it was reported that circRNA plays an important role in controlling the expression of miRNAs. So, in this study, miR-509-3p mimics or inhibitor vector will be constructed and transfected into PCOS cumulus cells. The differentially expressed circRNAs will be identified by microarray. Moreover, the interaction role of circRNA and miR-509-3p will be further investigated. In addition, candidate circRNAs will be expected as biomarkers to predict the occurrence of PCOS for adolescent female.

多囊卵巢综合征（PCOS）是育龄妇女常见的内分泌紊乱性疾病，主要特征是排卵障碍。我们前期研究发现，PCOS患者卵巢颗粒细胞中高表达的miRNA-509-3p直接靶向抑制MAP3K8的表达，通过减少下游ERK1/2的磷酸化水平，消弱对雌激素合成的抑制，导致雌激素合成过多。高水平的雌激素抑制FSH的分泌，最终引发卵泡发育停滞。如此高表达的miRNA-509-3p如何被调控呢？最新研究认为，环状RNA可能作为“miRNA海绵”对目标miRNA起调控作用。因此，本研究拟通过构建miRNA-509-3p的过表达及抑制表达慢病毒载体感染PCOS原代颗粒细胞，采用环状RNA芯片筛选可能与miRNA-509-3p作用的circRNA，验证miRNA-509-3p与靶向circRNA间相互调控的作用机制。期望筛选到可预测PCOS发生的circRNA分子标记，为青春期PCOS早期诊断提供分子依据。

多囊卵巢综合征（PCOS）是一种育龄妇女常见的内分泌疾病，发病率约为5-10％。环状RNA（circRNA）能够作为竞争性内源性RNA（ceRNA），海绵miRNA进而影响mRNA稳定性或翻译过程。目前，尚无关于circRNA调控颗粒细胞对PCOS发病机制的研究报道。本课题以卵丘颗粒细胞为实验材料，筛选PCOS中差异表达的circRNA，最终确定PCOS差异表达的circRNA为hsa_circ_0043532、hsa_circ_0043533，hsa_circ_0097636。选择hsa_circ_0043532和hsa_circ_0043533为研究对象，通过生物信息学预测及实验验证hsa-miR-1270及hsa-miR-409-3p是hsa_circ_0043532和hsa_circ_0043533的靶基因。进一步对miR-1270进行研究，确定其对卵巢类固醇生成通路中的关键酶CYP19A1在转录后水平有直接影响，并且受circ_0043532的内源性竞争调控。同时对hsa_circ_0043533进行研究，发现其抑制KGN细胞凋亡、促进迁移的作用能被miR-409-3p抑制。我们同步检测了PCOS患者外周血circRNA的变化，发现hsa_circ_0097636和hsa_circ_0043533有可能成为诊断PCOS的生物标志。