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The intrinsic axon regeneration capacity is crucial for peripheral nerve regeneration after injury. Identifying key molecules involved in this process makes great contribution to the investigation of peripheral nerve injury repair. Alternative splicing (AS) is an important regulation mode of eukaryotic gene expression, which has been widely studied both in physiological and pathological processes. However, less is known about the role of AS in peripheral nerve regeneration. In this work, to identify the AS events associated with axon regeneration capacity, we analyzed the AS events during sciatic nerve injury repair by RNA sequencing (RNA-Seq) and replicate multivariate analysis of transcript splicing (rMATS). The differential AS events were underwent gene ontology enrichment and pathway analyses. Moreover, we identified a significantly increased AS event of neuronal cell adhesion molecule Nrcam (Nrcam-S), and demonstrated down-regulation of Nrcam-S by specific siRNAs inhibited axon regeneration of Dorsal Root Ganglion (DRG) neurons after sciatic nerve injury in vitro and in vivo . Additionally, we found expression levels of RNA binding proteins (RBPs) CUGBP Elav-like family member 3 (CELF3) and RNA binding protein fox-1 homolog 2 (Rbfox2) were markedly increased after sciatic nerve injury. Our data may serve as a resource useful for further understanding how AS contributes to molecular regulations in DRG during sciatic nerve regeneration. [ABSTRACT FROM AUTHOR]

Identifying novel molecules involved in axon regeneration of neurons in the peripheral nervous system (PNS) will be of benefit in obtaining a therapeutic strategy for repairing axon damage both in the PNS and the central nervous system (CNS). Metabolism and axon regeneration are tightly connected. However, the overall metabolic processes and the landscape of the metabolites in axon regeneration of PNS neurons are uncovered. Here, we used an ultra high performance liquid tandem chromatography quadrupole time of flight mass spectrometry (UHPLC‐QTOFMS)‐based untargeted metabolomics to analyze dorsal root ganglia (DRG) metabolic characteristics at different time points post sciatic nerve injury and acquired hundreds of differentially changed metabolites. In addition, the results reveal that several metabolic pathways were significantly altered, such as ‘Histidine metabolism’, ‘Glycine serine and threonine metabolism’, ‘Arginine and proline metabolism’, ‘taurine and hypotaurine metabolism’ and so on. Given metabolite could alter a cell's or an organism's phenotype, further investigation demonstrated that N, N‐dimethylglycine (DMG) has a promoting effect on the regenerative ability post injury. Overall, our data may serve as a resource useful for further understanding how metabolites contribute to axon regeneration in DRG during sciatic nerve regeneration and suggest DMG may be a candidate drug to repair nerve injury. [ABSTRACT FROM AUTHOR]

Increasing the intrinsic regeneration potential of neurons is the key to promote axon regeneration and repair of nerve injury. Therefore, identifying the molecular switches that respond to nerve injury may play critical role in improving intrinsic regeneration ability. The mechanisms by which injury unlocks the intrinsic axonal growth competence of mature neurons are not well understood. The present study identified the key regulatory genes after sciatic nerve crush injury by RNA sequencing (RNA-Seq) and found that the hub gene Vav1 was highly expressed at both early response and regenerative stages of sciatic nerve injury. Furthermore, Vav1 was required for axon regeneration of dorsal root ganglia (DRG) neurons and functional recovery. Krüppel-like factor 2 (Klf2) was induced by retrograde Ca2+ signaling from injured axons and could directly promote Vav1 transcription in adult DRG neurons. The increased Vav1 then promoted axon regeneration by activating Rac1 GTPase independent of its tyrosine phosphorylation. Collectively, these findings break through previous limited cognition of Vav1, and first reveal a crucial role of Vav1 as a molecular switch in response to axonal injury for promoting axon regeneration, which might further serve as a novel molecular therapeutic target for clinical nerve injury repair. • Hub gene Vav1 is elevated in DRG neurons after peripheral nerve injury • Vav1 is required for axon regeneration and functional recovery of DRG neurons • Transcription factor Klf2 regulates Vav1 during injury response • Vav1 promotes axon regeneration by activating Rac1 GTPase [ABSTRACT FROM AUTHOR]

Successful axon regeneration is crucial for the treatment of numerous nerve injuries and neurodegenerative diseases, which requires adequate and accurate protein synthesis, including mRNA translation, both in the neuron somas and locally in the axons. Recent studies have shed light on novel functions and mechanisms of protein synthesis that are relevant for axon regeneration, with a particular focus on local translation. Here, we review the new developed technologies and approaches for investigating local translation, discuss the roles of local translation in axon regeneration, and summarize the key signaling molecules and pathways that regulate local translation during axon regeneration. Additionally, we give an overview of local translation in the peripheral and central nervous systems neurons and the latest progress in protein synthesis in neuron somas respectively. Finally, we consider the potential directions for future research in this field to provide insights into protein synthesis in axon regeneration. • Protein synthesis plays an important role in axon regeneration. • New approaches were developed to investigate protein synthesis in axons. • Several molecules regulating protein synthesis for axon regeneration were identified. • The correlation between protein synthesis in the axon and soma is worth attention. [ABSTRACT FROM AUTHOR]