MiR-128-1-5p regulates differentiation of ovine stromal vascular fraction by targeting the KLF11 5′-UTR

Fat content is an important index to evaluate the individual performance of livestock animals such as sheep for meat production purposes. Reducing the subcutaneous and visceral fat while increasing the intramuscular fat is a valuable goal to achieve for the meat production industry. Here, we investigated the effect of miR-128-1-5p on adipogenesis of subcutaneous fat by targeting 5’-UTR in KLF11, a rare mechanism where most miRNAs bind the 3’-UTR of mRNAs. A dual fluorescence reporter assay was conducted to validate the binding sites of miR-128-1-5p on 5’-UTR of KLF11 mRNA. Roles of miR-128-1-5p in KLF11 expression were measured through co-transfecting miRNA mimics with KLF11-expressing vectors (CDSs together with or without the 5′-UTR) into ovine stromal vascular fractions (SVF). Additionally, functional roles of miR-128-1-5p, and KLF11 in adipogenesis of ovine subcutaneous fat were investigated. Results showed that miR-128-1-5p targeted KLF11 5′-UTR, reduced the fluorescence activity of the dual fluorescent reporter vector, as well as KLF11 mRNA, and protein expression levels. During the differentiation of SVF, disturbing the expression of miR-128-1-5p and KLF11 changed the adipogenic differentiation of SVF as observed in the lipid formation, and adipogenic marker genes. This study indicates that miR-128-1-5p promotes the expression of lipogenic marker genes and the formation of lipid droplets by targeting KLF11 5′-UTR. Furthermore, overexpression, and inhibition of KLF11 indicate that KLF11 inhibited SVF differentiation. In summary, the 5’-UTR binding mechanism discovered in this study extends the understanding of miRNA functions. Key roles of miR-128-1-5p and KLF11 in the adipogenesis of sheep subcutaneous fat have potential values for improving the meat and/or fat ratio of domestic animals.