Preserving neuromuscular synapses in ALS by stimulating MuSK with a therapeutic agonist antibody.

Abstract

In amyotrophic lateral sclerosis (ALS) and animal models of ALS, including <i>SOD1-G93A</i> mice, disassembly of the neuromuscular synapse precedes motor neuron loss and is sufficient to cause a decline in motor function that culminates in lethal respiratory paralysis. We treated <i>SOD1-G93A</i> mice with an agonist antibody to MuSK, a receptor tyrosine kinase essential for maintaining neuromuscular synapses, to determine whether increasing muscle retrograde signaling would slow nerve terminal detachment from muscle. The agonist antibody, delivered after disease onset, slowed muscle denervation, promoting motor neuron survival, improving motor system output, and extending the lifespan of <i>SOD1-G93A</i> mice. These findings suggest a novel therapeutic strategy for ALS, using an antibody format with clinical precedence, which targets a pathway essential for maintaining attachment of nerve terminals to muscle.