miR-454 regulates triglyceride synthesis in bovine mammary epithelial cells by targeting PPAR-γ.

Triglycerides account for 99% of milk fat and play a central role in determining dairy product quality. Many factors influence triglyceride synthesis and milk fat secretion. MicroRNAs have been verified to be involved in numerous biological processes, but little is known about their roles in milk fat biosynthesis. In this study, we aim to explore whether miR-454 could regulate triglyceride synthesis in bovine mammary epithelial cells (BMECs) by targeting PPAR-γ. A luciferase reporter assay showed that the predicted target site was correct and that miR-454 and PPAR-γ had a direct interaction. In addition, miR-454 mimics and inhibitors were transfected into BMECs. The results showed that both the mRNA and protein levels of PPAR-γ were negatively correlated with miR-454 expression. Fat droplet accumulation and triglyceride production were also inversely correlated with miR-454 expression. Our results indicate that miR-454 regulates triglyceride synthesis by directly targeting the PPAR-γ 3' UTR in BMECs, suggesting that miR-454 could potentially be a new factor to elevate dairy product quality.