Repurposing of Trimetazidine for Amyotrophic Lateral Sclerosis: a study in SOD1 G93A mice

Background and purpose: Amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by the degeneration of upper and lower motor neurons, progressive wasting and paralysis of voluntary muscles is currently incurable despite intense research and numerous unsuccessful clinical trials. Although considered as a pure motor neuron disease, increasing evidence indicates that the sole protection of motor neurons by a single target drug is not sufficient to improve the pathological phenotype. We therefore evaluated the therapeutic potential of the multi-target drug, trimetazidine, in SOD1G93A mice. Experimental approach: Trimetazidine is an anti-ischemic drug used for the treatment of coronary artery disease. As a metabolic modulator, Trimetazidine improves glucose metabolism. Furthermore, Trimetazidine enhances mitochondrial metabolism and promotes nerve regeneration, exerting an anti-inflammatory and antioxidant effect. Here, we orally treated SOD1G93A mice with Trimetazidine, solubilized in drinking water at a dose of 20 mg/kg, from disease onset. We assessed the impact of Trimetazidine on disease progression by studying metabolic parameters, grip strength, and histological alterations in skeletal muscle, peripheral nerve and spinal cord. Key results: Trimetazidine administration delays motor function decline, improves muscle performance and metabolism, and significantly extends overall survival of SOD1G93A mice (increased median survival of 16 days and 12.5 days for male and female respectively). Moreover, Trimetazidine prevents the dismantlement of neuromuscular junctions, attenuates motor neuron loss and reduces neuroinflammation in the spinal cord and in peripheral nerves. Conclusion and implications: In SOD1G93A mice, therapeutic effect of Trimetazidine is underpinned by its action on mitochondrial function in skeletal muscle and spinal cord. Keywords: Amyotrophic Lateral Sclerosis; Hypermetabolism; Mitochondria; Neurodegeneration; SOD1G93A mice; Trimetazidine.