Interleukin-6 modifies the expression profile of microRNA in rat primary skeletal muscle cells

In the present study we examined the expression profile of microRNA in rat primary skeletal muscle cells (RSkMC) treated with IL-6, a known adipo-myokine and an inflammation-associated factor. The miRNA microarray analysis revealed increased expression of 2 miRNA species, which were not yet described in skeletal muscle, in RSkMC exposed to IL-6 (1 ng/ml) for 11 days of differentiation. In order to verify the microarray data, qRT-PCR analysis was performed to quantify miRNA expression. We confirmed the increased expression of miR-154-3p (fold change =3.25) and miR-338-3p (fold change =3.37). Using Target Scan database we found potential targets for these miRNAs with expression modified by IL-6 and focused our further interest on genes involved in cytoskeleton organization and cell migration, that is: ephrinA4, pacsin3, actin, alpha-actinin, dyneins and desmin. We compared the miRNA expression profiles of RSkMC exposed to IL-6 (1 ng/ml) for 11 days of differentiation to control group (untreated samples). Three or four microarrays were done for each experimental condition.