Mesenchymal stem cell–derived extracellular vesicle treatment of induced pluripotent stem cell–derived motor neurons with different amyotrophic lateral sclerosis genetic backgrounds

Motor neurons derived from induced human pluripotent stem cells offer a powerful model to study motor neuron diseases, such as amyotrophic lateral sclerosis. While widely used, our knowledge of the proteomic changes in these models is rather rudimentary. In this study, we conducted a comparative proteomic analysis of induced pluripotent stem cell-derived motor neurons carrying amyotrophic lateral sclerosis-associated mutations in C9ORF72, TARDBP, or FUS. This revealed both mutation-specific and shared proteomic signatures, unveiling common and divergent disease mechanisms. Using these new insights, we then evaluated the therapeutic potential of mesenchymal stem cell-derived extracellular vesicles. These experiments showed a functional effect of mesenchymal stem cell-derived extracellular vesicles in amyotrophic lateral sclerosis-FUS motor neurons in vitro and their ability to reverse proteomic changes more generally in motor neurons with different amyotrophic lateral sclerosis genetic backgrounds. These findings highlight key molecular pathways involved in amyotrophic lateral sclerosis at the protein level and support the potential of mesenchymal stem cell-derived extracellular vesicles as a versatile therapeutic approach.