Sirtuin-1 activation and antioxidant-based strategies for boosting exon-skipping efficiency in Duchenne Muscular Dystrophy: combination approach and nutraceutics in innovative pharmacotherapy

Duchenne Muscular Dystrophy (DMD) is an X-linked degenerative illness caused by mutations of DMD gene encoding dystrophin. DMD has an incidence of 1:3500-5000 and a prevalence of 4.8:100,000 males worldwide. It is characterized by progressive muscle wasting and weakness, leading to respiratory failure. Cardiomyocyte loss and diastolic dysfunction progress towards dilated cardiomyopathy and end-stage heart failure complicating the DMD prognosis. A resolutive therapy for DMD is still lacking as pharmacological approaches limit or slow damage but do not cure the defect; interventions regulating gene expression, while solving the pathogenic defect, suffer from limits in bioavailability that reduce their efficacy. The aim of this project is to solve this conundrum acting both by enhancing the bioavailability of gene expression-based therapeutics and to act downstream of it with effective pharmacological strategies that target downstream pathogenic events, to improve effectiveness and clarify novel targets of relevance. Exon-skipping therapy via antisense oligonucleotides (AO) is one of the most promising gene repair therapies for DMD. Different AO treatments are currently in use for DMD, although their efficacy remains controversial. A combined treatment of AO-mediated exon-skipping therapy with different drugs that have a role in muscle homeostasis could help in maintaining muscle integrity limiting muscle wasting. SIRT1, a NADH-dependent class III histone deacetylase, when overexpressed attenuated muscle injury of dystrophic mice. We will test the combination of AO therapy with sirtuin-1 (SIRT1) activator SRT2104, that exerts positive effects on dystrophic muscle in our preliminary data. We will also test anti-oxidants that may act as nutraceuticals. The use of anti-oxidants combined with exon-skipping, may be a potent, feasible and safe therapy for boosting DMD muscle fibres repair. Anti-oxidants can be found as adjuvant diet integration and may reduce the indices of oxidative stress in DMD patients exerting protective effect. We will combine AO-mediated exon-skipping, SRT2104, and appropriate anti-oxidants to enhance therapeutic effects of gene expression approaches in animal models of DMD. Using in vivo and in systems, four multidisciplinary tasks will be designed to assess the potential synergistic effects of: A) exon-skipping + SRT2104; B) SRT2104 + anti-oxidants; C) exon-skipping + anti-oxidants; D) exon-skipping + SRT2104 + anti-oxidants. We will evaluate in detail the restoring of both skeletal and cardiac muscle at structural, molecular, and functional level. This will allow a better chance of identifying suitable therapeutic intervention and to have a comprehensive view of the bounty of the approaches identified to modulate DMD targets. If accomplished, this project would provide a proof-of-concept preclinical study of innovative pharmacotherapy able to boost, as an add-on treatment, the therapeutic gene repair of muscular dystrophy.