Bta-miR-365-3p-targeted FKBP5 participates in the AMPK/mTOR signaling pathway in the regulation of preadipocyte differentiation in cattle.

OBJECTIVE: MicroRNAs (miRNAs) are endogenous non-coding RNAs that can play a role in the post-transcriptional regulation of mammalian preadipocyte differentiation. However, the precise functional mechanism of its regulation of fat metabolism is not fully understood.

METHODS: We identified bta-miR-365-3p, which specifically targets the 3'untranslated region (3'UTR) of the FK506-binding protein 5 (FKBP5),and verified its mechanisms for regulating expression and involvement in adipogenesis.

RESULTS: In this study, we found that the overexpression of bta-miR-365-3p significantly decreased the lipid accumulation and triglyceride content in the adipocytes. Compared to inhibiting bta-miR-365-3p group, overexpression of bta-miR-365-3p can inhibit the expression of adipocyte differentiation-related genes C/EBPα and PPARγ. The dual-luciferase reporter system further validated the targeting relationship between bta-miR-365-3p and FKBP5. FKBP5 mRNA and protein expression were detected by qRT-PCR and Western blot. Overexpression of bta-miR-365-3p significantly down-regulated FKBP5 expression, while inhibition of bta-miR-365-3p showed the opposite, indicating that bta-miR-365-3p negatively regulates FKBP5. AMPK/mTOR signaling pathway is closely related to the regulation of cell growth and is involved in the development of bovine adipocytes. In this study, overexpression of bta-miR-365-3p significantly inhibited mRNA and protein expression of AMPK, mTOR, and SREBP1 genes, while the inhibition of bta-miR-365-3p expression was contrary to these results. Overexpression of FKBP5 significantly upregulated AMPK, mTOR, and SREBP1 gene expression, while inhibition of FKBP5 expression was contrary to the above experimental results.

CONCLUSION: In conclusion, these results indicate that bta-miR-365-3p may be involved in the AMPK/mTOR signaling pathway in regulating Yanbian yellow cattle preadipocytes differentiation by targeting the FKBP5 gene.