MOV10 Promotes the Proliferation of Goat Mammary Epithelial Cells by Regulating the miR-21-5p-Mediated TGFβ/Smad7 Signaling Pathway

The number of mammary epithelial cells in lactating dairy goats is important for milk yield and is influenced by both hormonal and nutritional factors. Previous studies have reported that the MOV10 is involved in the miRNA splicing process. Moreover, MOV10 has been confirmed to play an important regulatory role in the proliferation of goat epithelial cells; however, its specific molecular regulatory network remains unclear. Therefore, this study aims to further elucidate the mechanism of action of MOV10 in goat epithelial cells. This study demonstrates that MOV10 plays a critical regulatory role in the proliferation and apoptosis of mammary epithelial cells. Downregulating the expression of MOV10 inhibited proliferation and promoted apoptosis, whereas upregulating its expression produced the opposite effect. RNA immunoprecipitation (RIP) assays revealed that MOV10 binds to pre-miR-21 and promotes its processing into mature miR-21-5p. miR-21-5p subsequently activates the TGF-β/Smad signaling pathway by targeting and inhibiting Smad7, thereby promoting epithelial cell proliferation. This study provides a novel perspective on lactation in dairy goats, suggesting that targeting MOV10-mediated signaling may represent an important strategy for increasing the milk yield.