CDYL/Kisspeptin/KISS1R信号通路异常致卵巢储备功能下降的机制研究

卵巢储备功能下降（DOR）严重影响女性生殖健康，颗粒细胞过度凋亡是导致DOR的重要原因，凋亡诱因不详。表观调控因子CDYL在生殖中发挥关键作用，预实验发现：其在卵巢储备正常女性颗粒细胞表达丰富；DOR患者颗粒细胞中CDYL表达下降，且凋亡增加；颗粒细胞条件性敲除Cdyl雌鼠呈类似DOR表型，生育力下降，颗粒细胞凋亡增加；颗粒细胞转录组测序和验证发现KISS1是CDYL下游关键因子，在DOR组表达升高；细胞系中敲低CDYL，致KISS1启动子区表观修饰改变，KISS1表达升高，凋亡增加；抑制KISS1或KISS1R，凋亡均减少；由此推测CDYL表达下降激活Kisspeptin/KISS1R信号通路促进颗粒细胞凋亡。本项目拟从细胞、分子水平并借助模型雌鼠，从表观调控角度深入研究CDYL低表达致DOR患者颗粒细胞过度凋亡新机制，揭示其在维持卵巢储备中的新功能，为预测和改善卵巢储备功能提供新思路。

Decreased ovarian reserve function (DOR) seriously affects female reproductive health. Excessive apoptosis of granulosa cells, the mechanism under which remaining unknown, is an important cause of DOR. CDYL, an epigenetic inhibitory factor plays an important role in the reproduction. Our preliminary experiments showed that CDYL was highly expressed in female granulosa cells with normal ovarian reserve function, while significantly decreased in the DOR group with increased granulosa cell apoptosis. Mice with Cdyl conditional deficiency in ovarian granulosa cells (Cdyl cko) exhibited a DOR-like phenotype with poor fecundity and increased granulosa cell apoptosis. RNA sequencing of granulosa cells and the following verification suggested that KISS1 was determined as the crucial downstream target of CDYL, and the expression of KISS1 in DOR group was significantly increased. The low expression of CDYL caused changes of epigenetic modification of KISS1 promoter region and increased KISS1 expression and granulosa cell apoptosis as well, while knockdown of KISS1 or knockdown of KISS1R reduced cell apoptosis. Thus, we hypothesized that under-expression of CDYL activated granulosa cell apoptosis by regulating of the Kisspeptin/KISS1R signaling pathway. Through exploring from the molecular, cellular, and established Cdyl cko mice model levels, this project intends to reveal the new mechanism of abnormal apoptosis of granulosa cells in DOR patients caused by decreased expression of CDYL, thus to elucidate the new function of CDYL in ovarian reserve，and to provide insights for the prediction and improvement of ovarian reserve function.