Molecular inflammatory mediators in peripheral nerve degeneration and regeneration.

Wallerian degeneration, the self-destructive set of cellular and molecular processes by which degenerating axons and myelin are cleared after injury, is initiated by macrophages and Schwann cells. Molecular inflammatory mediators such as cytokines (IL-1, IL-6, IL-10, and TNF-alpha, among others), transcription factors (NF-kappaB, c-Jun), the complement system and arachidonic acid metabolites have been shown to modulate these processes in various studies. However, the exact role that each of these mediators plays during axonal degeneration and regeneration has not been fully established. Understanding the molecular basis of these interactions between the immune system and peripheral nerve injury would open the possibility of targeting these inflammatory mediators as therapeutic interventions. In this review we attempt to integrate the current evidence generated around this issue, and to explore the therapeutic possibilities that arise.