Defective excitation-contraction coupling and mitochondrial respiration precede mitochondrial Ca2+ accumulation in spinobulbar muscular atrophy skeletal muscle

Marchioretti and colleagues show that in the skeletal muscle of SBMA mice and patients there is an early, but reversible alteration of expression of genes involved in muscle contraction and of mitochondrial respiration, followed by accumulation of calcium inside the mitochondria, which is concomitant with the onset of motor dysfunction, and late alteration of muscle structure.