Pretreatment of nerve grafts with resveratrol improves axonal regeneration following replantation surgery for nerve root avulsion injury in rats.

BACKGROUND: Replantation of the avulsed nerve root has been proposed for the treatment of severe brachial plexus injury for several decades. However, due to the complexity of the technique and limited functional improvement, practical applications are yet to be implemented. OBJECTIVE: In the present study, we investigated the effect of pretreatment with resveratrol on nerve autografts used for replantation surgery in a rat model of nerve root avulsion. METHODS: Resveratrol pretreatment was performed using an explant culture technique. Two surgical procedures were performed. During the first surgery, Sprague-Dawley rats were subjected to left C6 nerve root avulsion, and nerves were harvested for autografting. The harvested grafts were explant-cultured for 1 week. A second procedure was performed to replant the C6 nerve root using the explant-cultured nerve graft 1 week after the first procedure. Histological and immunohistochemical analyses were performed 8 weeks after the second procedure. We first compared findings between explant-cultured nerve grafts and fresh nerve grafts, following which we compared findings between explant-cultured grafts pretreated with and without resveratrol. Changes induced within nerve grafts by 1 week of explant culture with or without resveratrol were investigated in vitro. RESULTS: There was no significant difference in outcomes between 1 week-explant-cultured and fresh nerve grafts. Addition of resveratrol to the explant culture medium resulted in a significant increase in the number and myelin thickness of regenerated axons, and in the number of regenerating motor neurons in the C6 spinal cord segment. In vitro analyses revealed that nerve grafts pretreated with resveratrol exhibited significant increases in glial cell line-derived neurotrophic factor (GDNF) expression and the number of dedifferentiated Schwann cells. CONCLUSIONS: Resveratrol may promote axonal regeneration following replantation surgery for the treatment of nerve root avulsion injury; however, further studies are required to verify these findings in humans.

Differentiation of neural stem cells transplanted into ventral horn of spinal cord after brachial plexus avulsion / 中华显微外科杂志

Objective To study the survival,migration and differentiation of the neural stem cells which transplanted into ventral horn of spinal cord after brachial plexus avulsion.Methods Neural stem ceils isolated from spinal cord of neogenetic rats and cultured,expanded,labeled by BrdU before transplanted. Twenty adult healthy SD rats preformed as the model of brochial plexus avulsion(Roots C_(5～7)),then transplan- rod stem ceils into the C_6 ventral horn of spinal cord.On 1,2,4,8,12 weeks postoperatively,immunohisto- chemistry assay were carried out in the spinal cord.Results Transplanted into ventral horn of spinal cord after brachial plexus avulsion.Neural stem cells can survive,migrate for at least one segment of spinal cord and differentiate to neurons and astrocytes.The differentiation of stem cells were time-depends.Conclusion Neural stem cells can survive,migrate and differentiate after transplanted into ventral horn of spinal cord in the rats which suffered from brachial plexus avulsion.