The Regeneration of Peripheral Nerves Depends on Repair Schwann Cells

After nerve injury, axons can potentially regenerate. In large part, this is because distal to injury, myelin and Remak Schwann cells convert to repair Schwann cells, which are specialized to promote repair. This cellular reprogramming combines activation of a repair program with the dedifferentiation of myelin cells. The repair program involves upregulation of trophic factors and cytokines, morphological transformation to form Bungner bands, and myelinophagy to remove myelin sheaths. The transcription factor c-Jun plays a central part in the control of the repair program. In the absence of c-Jun in Schwann cells, damage results in the formation of a dysfunctional repair cells, neuronal death, and failure of functional recovery. In the future, c-Jun, STAT3, and other signals, which control repair cells, require further analysis so that pharmacological tools that boost and maintain the repair Schwann cell phenotype can be developed.