CircRNA_01754 Regulates Milk Fat Production Through the Hippo Signaling Pathway.

BACKGROUND: Milk fat metabolism is a complex process regulated by non-coding RNAs. circRNAs (circRNAs) can act as miRNA sponges to regulate target gene expression. PURPOSE: This study aimed to investigate the role and mechanism of the circRNA_01754/miR-302c/LATS2 axis in regulating milk fat metabolism in bovine mammary epithelial cells (BMECs). METHODS: mRNA sequencing was performed on bovine mammary gland tissues from different lactation stages to analyze the expression profiles. The interactions between circRNA_01754, miR-302c, and LATS2 were verified using dual-luciferase reporter assays, qRT-PCR, and Western blot. The functional effects on triglyceride (TAG) and cholesterol synthesis were assessed. RESULTS: CircRNA_01754 was identified as a direct sponge for miR-302c. Overexpression of circRNA_01754 increased LATS2 expression by sequestering miR-302c. Functional experiments showed that circRNA_01754 and LATS2 promoted TAG synthesis, whereas miR-302c inhibited it. Furthermore, miR-302c was found to regulate the expression of YAP1, a key effector of the Hippo pathway, through LATS2. CONCLUSIONS: Our findings reveal that circRNA_01754 promotes milk fat synthesis by acting as a ceRNA for miR-302c to upregulate LATS2. This study lays the groundwork for producing high-quality milk and opens up new avenues for enhancing public dietary health.