Enriched conditioning expands the regenerative ability of sensory neurons after spinal cord injury via neuronal intrinsic redox signaling

Nat Commun. 2020 Dec 21;11(1):6425. doi: 10.1038/s41467-020-20179-z.

Abstract

Overcoming the restricted axonal regenerative ability that limits functional repair following a central nervous system injury remains a challenge. Here we report a regenerative paradigm that we call enriched conditioning, which combines environmental enrichment (EE) followed by a conditioning sciatic nerve axotomy that precedes a spinal cord injury (SCI). Enriched conditioning significantly increases the regenerative ability of dorsal root ganglia (DRG) sensory neurons compared to EE or a conditioning injury alone, propelling axon growth well beyond the spinal injury site. Mechanistically, we established that enriched conditioning relies on the unique neuronal intrinsic signaling axis PKC-STAT3-NADPH oxidase 2 (NOX2), enhancing redox signaling as shown by redox proteomics in DRG. Finally, NOX2 conditional deletion or overexpression respectively blocked or phenocopied enriched conditioning-dependent axon regeneration after SCI leading to improved functional recovery. These studies provide a paradigm that drives the regenerative ability of sensory neurons offering a potential redox-dependent regenerative model for mechanistic and therapeutic discoveries.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / pathology
  • Axotomy
  • Ganglia, Spinal / pathology
  • Mice, Inbred C57BL
  • NADPH Oxidase 2 / metabolism
  • Nerve Regeneration*
  • Neuronal Outgrowth
  • Neuronal Plasticity
  • Oxidation-Reduction
  • Phosphorylation
  • Promoter Regions, Genetic / genetics
  • Protein Kinase C / metabolism
  • Protein Subunits / metabolism
  • Reactive Oxygen Species / metabolism
  • STAT3 Transcription Factor / metabolism
  • Sciatic Nerve / physiopathology
  • Sensory Receptor Cells / metabolism*
  • Sensory Receptor Cells / pathology*
  • Signal Transduction*
  • Spinal Cord Injuries / physiopathology*
  • Up-Regulation

Substances

  • Protein Subunits
  • Reactive Oxygen Species
  • STAT3 Transcription Factor
  • Cybb protein, mouse
  • NADPH Oxidase 2
  • Protein Kinase C