Neural stem cell transplantation for partial sciatic nerve transaction-induced neuropathic pain：the optimal cell number for transplantation / 中国组织工程研究

ABSTRACT

BACKGROUND:Studies have shown that neural stem cel transplantation has a certain effect on neuropathic pain, but the efficacy of transplanted cel number on neuropathic pain is not exactly understood. OBJECTIVE:To observe the effect of different amount of neural stem cels administered intrathecaly on the neuropathic pain and expression of glial-derived neurotrophic factor in the spinal cord dorsal horn and dorsal root ganglion in rats after partial sciatic nerve transaction. METHODS:A Sprague-Dawley rat at 14-16 days of pregnancy was used to prepare neural stem cel suspensions that were injected intrathecaly into rat models of partial sciatic nerve transaction at doses of 1×103, 1×104, 1×105, 1×106, 1×107cels per 30 μL, respectively. Additionaly, model group and sham-operated group were set up. Threshold values of mechanical and thermal pain were recorded 1 day before operation, 1, 3, 7, 14, 21 days after operation. Expressions of glial-derived neurotrophic factor protein and mRNA in the ipsilateral spinal cord dorsal horn and dorsal root ganglion were detected by immunohistochemistry and RT-PCR, respectively, at 7 and 21 days after partial sciatic nerve transaction. RESULTS AND CONCLUSION: Pain threshold values were decreased in al the groups except the sham-operated group at 1 day after operation, and reached the peak at 7 and 14 days after operation (P < 0.05). Compared with the model group, the pain threshold values and the expression of glial-derived neurotrophic factor protein and mRNA in the ipsilateral spinal cord dorsal horn and dorsal root ganglion were increased gradualy in a dose-dependent manner in the 1×104, 1×105, 1×106, 1×107 groups at 7 days after operation (P < 0.05). At 21 days post-operation, the pain threshold values showed no differences from the preoperative findings in the 1×105, 1×106, 1×107 groups, but the expression of glial-derived neurotrophic factor was significantly higher in the 1×105 group than the other groups (P < 0.05). Taken together, intrathecal transplantation of neural stem cels at a dose of 1×105 is the most effective in aleviating partial sciatic nerve transaction-induced neuropathic pain in rats.