Mir-let-7a/g Enhances Uterine Receptivity via Suppressing Wnt/β-Catenin Under the Modulation of Ovarian Hormones

Microarray has indicated a huge number of miRNAs exist in reproductive tissues and cells. Moreover, the expression of miRNA in the reproductive system varies under the strict monitoring of different regulations. To understand the role of miRNA-mediated post-transcriptional gene regulation in female reproduction, we investigated the level and function of a mir-let-7 family member in both mice and human uterine receptivity. As we observed, mir-let-7 a/g had a higher expression in mouse and human receptive uterine epithelium; the level of mir-let-7a was under the inverse regulation of estrogen and progesterone; upregulated mir-let-7a/g in mouse and human uterine epithelium increased uterine receptivity, thus improved implantation-related embryo attachment and outgrowth ability; the let-7a/g enhanced uterine receptivity through suppressing canonical Wnt signaling. In summary, our findings suggest that mir-let-7 a/g increases uterine receptivity via inhibiting Wnt signaling and under the modulation of ovarian hormones.