Effects of MicroRNA-23a on Differentiation and Gene Expression Profiles in 3T3-L1 Adipocytes.

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate growth, development, and programmed death of cells. A newly-published study has shown that miRNA-23a could regulate 3T3-L1 adipocyte differentiation. Here, we identified miRNA-23a as a negative regulator of 3T3-L1 adipocyte differentiation again. Over-expression of miRNA-23a inhibited differentiation and decreased lipogenesis as well as down-regulated mRNA and protein expression of both peroxisome proliferator-activated receptor (PPAR) γ and fatty acid binding protein (FABP) 4, whereas knock down of miRNA-23a showed the opposite effects on differentiation as well as increasing the number of apoptotic cells. Additionally, digital gene expression profiling sequencing (DGE-Seq) was used to assay changes in gene expression profiles following alterations in the level of miR-23a. In total, over-expression or knock down of miRNA-23a significantly changed the expression of 313 and 425 genes, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these genes were mainly involved in the stress response, immune system, metabolism, cell cycle, among other pathways. Additionally, the signal transducer and activator of transcription 1 (Stat1) was shown to be a target of miRNA-23a by computational and dual-luciferase reporter assays that indicated Janus Kinase (Jak)-Stat signal pathway was implicated in regulating adipogenesis mediated by miRNA-23a in adipocytes.