Lack of dystrophin in mdx mice modulates the expression of genes involved in neuron survival and differentiation

Duchenne muscular dystrophy is an X-linked disease characterized by progressive and lethal muscular wasting. Dystrophic patients, however, are also afflicted by several neurological disorders, the importance of which is generally underestimated. As promising therapies for muscles are currently in clinical trial stages, with the potential to provide an increase in the lifespan of young patients, determination of the genetic and molecular aspects characterizing this complex disease is crucial in order to allow the development of therapeutic approaches specifically designed for the nervous system. In this study, differences in gene expression in the superior cervical ganglion of postnatal day (P)5, P10 and 67-week-old wild-type and genetically dystrophic mdx mice were evaluated by DNA microarray analysis. The main aim was to verify whether the lack of dystrophin affected the transcript levels of genes related to different aspects of neuron development and differentiation. Ontological analysis of more than 500 modulated genes showed significant differences in genetic class enrichment at each postnatal date. Upregulated genes mainly fell in the categories of vesicular trafficking, and cytoskeletal and synaptic organization, whereas downregulated genes were associated with axon development, growth factors, intracellular signal transduction, metabolic processes, gene expression regulation, synapse morphogenesis, and nicotinic receptor clustering. These data strongly suggest that the structural and functional alterations previously described in both the autonomic and central nervous systems of mdx mice with respect to wild-type mice and related to crucial aspects of neuron life (i.e. postnatal development, differentiation, and plasticity) result not only from protein post-translational modifications, but also from direct and/or indirect modulation of gene expression.