MicroRNA signature in mdx dystrophic mice overexpressing mIGF-1 in Abstracts of the XII annual meeting of the Interuniversity Institute of Myology | Reggio Emilia, Italy, October 1-4, 2015

Duchenne muscular dystrophy (DMD) is a genetic disease in which loss of functional dystrophin protein results in progressive skeletal muscle degeneration. Although the genetic defect is widely known, the mechanisms by which the absence of dystrophin leads to the complex pathophisiology of the disease is not completely understood. MiRNAs are small non coding RNA that are important regulatory elements for muscle development and function [1]. Altered levels of specific miRNAs were found in several muscular disorders, including DMD [2, 3]. In particular it has been identified a specific DMD-signature miRNAs that may serve as a marker for therapeutic purposes [4]. Moreover, in a recent work it has been defined a specific group of miRNAs strictly correlated to dystrophin levels and whose deregulated expression could explain several pathogenetic features of DMD [5]. Previously we have demonstrated that the local expression of mIGF-1 in mdx mice ameliorates the dystrophic phenotype reducing myonecrosis and upregulating survival pathways such as AKT pathway [6]. In this work, we show that a specific group of miRNAs, dystrophin-indipendent, are modulated by mIGF-1 expression. In particular, local expression of mIGF-1 promotes the modulation of miR-206 and miR-24 as well as muscle specific genes associated with maturation of regenerating muscle fibers and differentiation. These results indicates that local overexpression of the anabolic factor mIGF-1 in mdx mice ameliorates the dystrophic microenviroment modulating the expression of a specific group of miRNAs and inducing a partial rescue of the characteristic DMD-signature.