Identification of microRNAs involved in dexamethasone-induced muscle atrophy.

MicroRNAs (miRNAs), a novel class of post-transcriptional gene regulators, have been demonstrated to be involved in several cellular processes regulating the expression of protein-coding genes. To investigate the mechanisms of miRNA-mediated regulation during the process of muscle atrophy, we performed miRNA microarray hybridization between normal differentiated C2C12 cells and dexamethasone (DEX)-treated C2C12 cells. We observed that 11 miRNAs were significantly up-regulated and six miRNAs were down-regulated in the differentiated C2C12 cells after being treated with DEX. Stem-loop real-time RT-PCR confirmed the differential expression of six selected miRNAs (miR-1, miR-147, miR-322, miR-351, and miR-503*, miR-708). miRNA potential target prediction was accomplished using TargetScan, and many target genes related to muscle growth and atrophy have been reported in previous studies. The results of the current study suggested the potential roles of these differentially expressed miRNAs in skeletal muscle atrophy.