miR-107 targets WNT3A and BTRC to promote bovine endometrial epithelial cells receptivity.

When the endometrium achieves a receptive state, endometrial epithelial cells (EECs) are reshaped to facilitate embryo implantation. The establishment of endometrial receptivity is crucial for embryo implantation and successful pregnancy. This study investigated the regulatory effect of bta-miR-107 on endometrial receptivity in beef cattle at the molecular level. The research results indicated that miR-107 is upregulated in the blood of pregnant cattle and bovine endometrial epithelial cells (bEECs) induced by a combination of progesterone (P4) and interferon tau (IFN-τ). RNA-seq analysis illustrated that overexpression of miR-107 leads to differential expression of 69 mRNAs in receptive bEECs. These differentially expressed mRNAs (DE-mRNAs) were primarily enriched in steroid hormone biosynthesis, ovarian steroidogenesis and cAMP signaling pathways, which are implicated in endometrial receptivity. miR-107 overexpression and inhibition experiments results demonstrated that miR-107 promoted the receptivity and apoptosis of bEECs and inhibited the activity and proliferation ability of receptive bEECs. A dual luciferase reporter gene experiment showed that WNT3A and BTRC are target genes of miR-107. Moreover, interference with WNT3A and BTRC played a role similar to overexpression of miR-107. These results indicate that miR-107 promotes bEECs receptivity and apoptosis by downregulating WNT3A and BTRC expression and inhibits cell proliferation during the formation of bEECs receptivity.