Anti-inflammatory Signalling Molecule Improved Peripheral Nerve Repair

  • Fatemeh Basiri
  • Abbass Ali Imani Fooladi
  • Masoumeh Foroutan Koudehi
  • Babak Farzam
  • Shahnaz Shekarforoush
  • Mohammad Reza Nourani
Keywords: Tumor necrosis factor-α; Nerve Regeneration


Introduction: Early inflammatory procedures may inhibit functional recovery after nerve injury. Tumor necrosis factor-α (TNF) plays a crucial role in the initiation of degenerative cascades after peripheral nerve injury.The aim of this study was to test the effects of TNF antagonist etanerceptonnerve regeneration in a rat model of sciatic nerve crush injury.

Experimental Procedures: 15 adult Wistar rats underwent a surgical procedure involving right sciatic nerve crush injury. Etanercept(6 mg/kg) was administered intra-peritoneally (IP)once immediately after nerve crush in the experimental group.  Rats in the control group received saline IP post surgery. Genomic and immune-histochemical tests were done at 1, 3, 7, 21 and 42 days after injury. Functional and electromyography (EMG) assessments of nerves were performed at 7, 21 and 42 days after injury. Functional recovery was analyzed using hot plate test, a walking track assessment and quantified using the sciatic functional index (SFI).

Results: TNF mRNA expression was induced at 1 day and returned to baseline at the end of 1 week after injury in nerve. Etanerceptprevented increase of TNF in the crush site and enhanced the rate of axonal regeneration, as determined by increased number of characteristic clusters of regenerating nerve fibers distal to nerve crush segments, but it was not significant statistically with control group on 42 days. The statistical analyses of EMG studies showed that the latency and the amplitude in experimental group of 21 and 42 days were significantly different from the control group. SFI in the experimental group on 21 and 42 days was significantly higher than that of the control group.

Conclusion: This study established that immediate therapy with etanercept promotes the regeneration of peripheral nerve injuries in a rat model.


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