胚胎着床是妊娠成功与否的关键环节之一，机制尚未阐明。研究显示CircRNA与多种生理病理过程密切相关，可充当竞争性内源RNA与miRNA结合，进而解除miRNA对其靶基因的抑制，上调靶基因表达。课题组前期系统研究了miRNA在胚胎着床过程中的作用，但其上游CircRNA在胚胎着床子宫内膜容受性建立这一过程中的作用尚未有研究报道。本研究拟对临床流产患者、正常妊娠者蜕膜组织以及妊娠小鼠子宫内膜胚胎着床点及其旁组织进行CircRNA芯片检测，筛选子宫内膜容受性相关CircRNA，同时结合课题组前期miRNA芯片数据和基因芯片数据，按照“CircRNA-miRNA-mRNA”的思路，对CircRNA调控的下游靶miRNA-mRNA进行预测和验证，并通过一系列体内外功能实验证实CircRNA在容受性建立中的作用及调控机制。本项目将对着床失败所致不孕症的诊断和治疗以及新的生殖调控手段的开发有重要意义。

Embryo implantation is one of the key links in the pregnancy success, but the mechanism has not yet been elucidated. Studies have shown that CircRNA is closely related to a variety of physiological and pathological process. It can act as competitive endogenous RNA combined with miRNA, then remove the miRNA inhibition to its target genes and increase the expression of target genes. In embryo implantation, the function of miRNAs was systematically studied in our preliminary work, but its upstream circRNA function in embryo implantation and establishment of endometrial receptivity are unclear at present. This project aims to detect circRNA expression of decidual tissue from abortion patients and normal pregnancy as well as endometrial tissue of implantation site and inter-implantation site in the mouse by circRNA chip, in order to screen relevant CircRNA of the endometrial receptivity establishment. At the same time, combined with the our previous work of miRNA chip data and gene chip data, the downstream target miRNA - mRNA of CircRNA regulation will be predicted by bioinformatics according to the "CircRNA - micrornas - mRNA" train of thought, and further confirm its role and regulation mechanism in receptivity establishment through a series of functional trials in vivo and in vitro. This project will have a great clinical value in the diagnosis and treatment of infertility caused by Implantation failure and the improvement of assited reproduction.