Dr Melissa Bowerman : ‘Spinal muscular atrophy: more than just a motoneuron pathology’

Spinal muscular atrophy (SMA) is the most common genetic disease resulting in infant death, affecting approximately 1 in 6000 to 10000 births. This autosomal recessive disorder, resulting from the loss-of-function of the survival motor neuron 1 (SMN1) gene, is characterized by severe loss of spinal cord motoneurons, muscular atrophy and eventual paralysis. While the spinal cord motoneuron is undeniably the primary cellular target in SMA, we, along with others, have uncovered various non-neuronal roles for Smn at the neuromuscular junction, in skeletal muscle, in heart, in glial cells, in the pancreas as well as in glucose metabolism. However, the precise pathological pathways that are misregulated in these Smn-depleted non-neuronal compartments and/or tissues are not fully understood. With the contribution of peripheral tissues to SMA pathogenesis in mind, we are therefore investigating i) specific aberrant muscle atrophy signaling cascades that may promote and maintain the denervation-induced muscular atrophy, ii) the extent of metabolic perturbations in various metabolic tissues and iii) the therapeutic potential of targeting an ASO-conjugated cell penetrating peptide to both the central nervous system and the periphery for SMA therapy. Our overall goal is to better understand the cell- and non-cell-autonomous pathways that contribute to the pathophysiology of SMA and importantly, develop novel therapeutic strategies to correct the identified defects.