Exploration of targets regulated by miR-125b in porcine adipocytes

MicroRNA (miRNA) has been proved to play a key role in lipid metabolism. In our previous study, miR-125b was validated to be differentially expressed in preadipocytes and adipocytes, which was also proved to involve in lipid metabolism. To explore the comprehensive targets of miR-125b in adipocytes, isobaric tag for relative and absolute quantitation (iTRAQ) analysis was performed to obtain differentially expressed proteins in adipocytes comparing negative control (NC) and miR-125b mimic, combining with digital gene expression (DGE) profiling of mRNA incorporated into RNA-induced silencing complex (RISC) pulled down by biotinylated miR-125b mimic and targets prediction of miR-125b by three algorithms, acyl-CoA dehydrogenase short chain (ACADS) and mitochondrial trans-2-enoyl-CoA reductase (MECR) were screened out as miR-125b direct targets. Luciferase reporter assay further validated that miR-125b mimic significantly inhibited the luciferase activity by targeting wild type (WT) 3'-UTR compared with NC. qPCR analysis of ACADS and MECR mRNA from adipose tissues of miR-125b knockout (KO) mice further confirmed the inhibition of miR-125b on ACADS and MECR expressions. Here we report miR-125b play a vital role in maintaining homeostasis of fatty acid metabolism by targeting key enzyme ACADS and MECR in the process of fatty acid elongation and degradation.