MicroRNA-224 Impairs Adipogenic Differentiation of Bovine Preadipocytes by Targeting LPL

In this study, the potential functions of miR-224 in regulating adipogenic differentiation were explored in bovine preadipocytes. Comparative transcriptome analysis between castrated male cattle with increased intramuscular fat (IMF) and intact male cattle revealed that miR-224 and LPL were abnormally expressed, correlating negatively, and LPL was a predicted target of miR-224. A dual luciferase reporter assay confirmed the negative targeting regulatory relationship between miR-224 and LPL. When miR-224 was either overexpressed or silenced, qRT-PCR showed a negative regulatory effect on LPL. mRNA expression levels of the fat-formation-related biomarkers C/EBPα, C/EBPβ, PPARγ, FASN and PLIN1 decreased when miR-224 was overexpressed, while the opposite effect occurred and adipogenic differentiation followed when miR-224 was inhibited. Oil Red O staining. Triglyceride (TG) levels and immunostaining revealed that the accumulation of lipid droplets decreased or increased accordingly. Taken together, our data demonstrated that miR-224 regulated the adipogenic differentiation of bovine preadipocytes by targeting LPL. This provides insight into the molecular basis of IMF deposition in beef cattle.