Translational Regulation in Initial Stages of the Neuronal Injury Response. Mus musculus

Transcriptional events leading to outgrowth of neuronal axons have been intensively studied, but the role of translational regulation in this process is not well understood. Here we use translatome analyses by ribosome pull-down and protein synthesis characterization by metabolic isotopic labeling to study nerve injury and axon outgrowth proteomes in rodent dorsal root ganglia (DRG) and sensory neurons. We identify over 1600 gene products that are primarily translationally regulated in DRG neurons after nerve injury, many of which contain a 5’UTR CERT motif, implicating the translation initiation factor Eif4e in the injury response. We further identified approximately 200 proteins that undergo robust de novo synthesis in the initial stages of axon growth. ApoE is one of the highly synthesized proteins in neurons, and inhibition of its signaling affects axon outgrowth. These findings suggest prominent roles for translational regulation in initial stages of the neuronal injury response and axon extension. Overall design: Use Ribotag mice to identify cell type specific translatomes within dorsal root ganglia and observe their change following an injury to the sciatic nerve