Expression of thioredoxin-1 in the ASJ neuron corresponds with and enhances intrinsic regenerative capacity under lesion conditioning in C. elegans

Abstract

A conditioning lesion of the peripheral sensory axon triggers robust central axon regeneration in mammals. We trigger conditioned regeneration in the C. elegans ASJ neuron by laser surgery or genetic disruption of sensory pathways. Conditioning upregulates trx-1 expression, as indicated by trx-1 promoter-driven green fluorescent protein and fluorescence in situ hybridization, suggesting trx-1 levels and associated fluorescence indicate regenerative capacity. Redox activity of trx-1 functionally enhances conditioned regeneration, but both redox-dependent and -independent activity inhibit non-conditioned regeneration. Six strains isolated in a forward genetic screen for reduced fluorescence, which suggests diminished regenerative potential, also show reduced axon outgrowth. We demonstrate an association between trx-1 expression and the conditioned state that we leverage to rapidly assess regenerative capacity.