Parthenolide: a novel pharmacological approach to promote nerve regeneration.

Abstract

Traumatic axonal lesions disrupt the connections between neurons and their targets, leading to loss of motoric and sensory functions. Although lesioned peripheral nerves can principally regenerate, the rate of recovery depends on the mode and severity of the respective injury (Grinsell and Keating, 2014). While injuries close to the innervation site have good chances of recovery, long distance regeneration is particularly problematic due to relatively slow axonal growth rates, which even under favorable conditions do not normally exceed 1–2 mm per day (Sunderland, 1947). For this reason, re-growth into the respective target tissue can take several months or even years after nerve injuries in arms and legs. Within months, however, the regenerative support of Schwann cells declines and denervated muscles atbecome atrophic. Under these conditions, re-innervation of appropriate targets and consequently functional recovery are at least impaired if not impossible. Moreover, regenerating axons are often misguided and form so-called neuromas around the injury site, causing chronic, difficult-to-treat pain. Despite a high capacity for axonal regrowth in the peripheral nervous system, nerve injuries therefore often seriously impair the quality of life of affected patients and are overall associated with high socio-economic costs and long professional downtimes (Lad et al., 2010).