Novel Translational Concept: Axon-to-Muscle Exosomal Signaling as an Emerging Therapeutic Target in Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) has transitioned from a uniformly fatal disease to a treatable condition, yet incomplete neuromuscular recovery underscores the limits of current SMN-restorative therapies. Emerging data implicate disrupted axon-to-muscle exosomal signaling as an important, overlooked driver of residual dysfunction. Exosomes, nanovesicles mediating bidirectional neuronal-muscular communication, carry synaptic organizers, trophic factors, and microRNAs essential for neuromuscular junction integrity. SMN deficiency alters exosomal biogenesis and cargo, leading to loss of agrin-MuSK signaling, impaired β-actin transport, and muscle atrophy. Comparative insights from amyotrophic lateral sclerosis and muscular dystrophy reveal that stem-cell-derived or engineered exosomes restore synaptic stability, enhance regeneration, and cross biological barriers safely. Thus, we speculate herein on a translational model integrating exosome-based therapies with existing genetic interventions to achieve durable, systems-level recovery in SMA. Exosomal profiling may further yield minimally invasive biomarkers for disease monitoring and treatment optimization, establishing vesicle-mediated communication as a novel therapeutic axis in neuromuscular medicine.