MiR-224 impairs adipocyte early differentiation and regulates fatty acid metabolism.

MicroRNAs (miRNAs) are small ~22 nucleotide regulatory RNAs that regulate the stability and translation of cognate messenger RNAs (mRNAs). MicroRNAs participate in the regulation of adipogenesis and identification of the full repertoire of MicroRNAs expressed in adipose tissue is likely to improve our understanding of adipose tissue growth and development significantly. In the present study, it is found that miR-224-5p abundance decreases first and then increases during adipogenesis of 3T3-L1 cells. And early growth response 2 (EGR2) and Acyl-CoA synthetase long-chain family member 4 (ACSL4) are direct targets of miR-224-5p. Further studies in mouse 3T3-L1 cell-line shows that miR-224-5p is a novel negative regulator of adipocyte differentiation through post-transcriptional regulation of early growth response 2 during early adipogenesis. Furthermore, miR-224-5p could regulate fatty acid metabolism through Acyl-CoA synthetase long-chain family member 4 at terminal differentiation. It indicates that miR-224 plays different roles on different stages of adipogenesis.