Translatomic analysis of regenerating and degenerating spinal motor neurons in injury and ALS

The neuromuscular junction (NMJ) is a specialized synapse that allows for the communication between spinal motor neurons and muscle fibers. Maintenance of motor-muscle connectivity at the NMJ is critical for the preservation of muscle strength and coordinated motor function. Unlike injuries that damage the central nervous system, motor neurons can mount a robust regenerative response after peripheral nerve injuries. In contrast, motor neurons selectively degenerate in diseases such as amyotrophic lateral sclerosis (ALS), which leads to progressive muscle wasting and paralysis. To assess how different insults affect motor neurons in vivo, we adapted the RiboTag methodology developed by Sanz et al. to perform ribosomal profiling of mouse motor neurons. Using this strategy we isolated and sequenced motor neuron-specific transcripts from spinal cord tissue following sciatic nerve crush, a model of acute injury and regeneration, and in the SOD1-G93A mouse model of ALS. 50 total samples are included, in replicates of 3 (except 3-month RiboWT group, n=4). An RPL22-HA immunopreciptiation (IP) and input lysate controls is included for each sample. Injury samples contain injured (INJ) and uninjured (UNJ) controls and ALS samples are from RiboALS and RiboWT littermate mice at 1-mo, 3-mo, and 4-mo ages.