A型肉毒杆菌神经毒素重链干预大鼠脊髓损伤后蛋白表达的初步研究

Botulinum neurotoxin type A heavy chain intervenes in expression of general proteins in spinal cord after unilateral spinal cord injury in rats

目的:初步观察大鼠脊髓损伤模型基础上局部注射小剂量A型肉毒杆菌神经毒素重链(BoNT/A HC)后对局部蛋白表达谱的影响,为探讨BoNT/A HC干预在体神经损伤后相关蛋白表达及其干预神经再生机制提供实验基础。方法:复制大鼠单侧腰段脊髓损伤模型;采用SDS-PAGE及双向电泳观察不同剂量BoNT/A HC(2μg、4μg、6μg和8μg)对脊髓损伤后局部(包括损伤部位及其近头端部分脊髓组织)蛋白表达谱的干预作用。结果:大鼠单侧腰段脊髓损伤2 d时局部脊髓组织结构明显破坏崩解,损伤波及左侧脊髓灰质及白质;脊髓损伤局部SDS-PAGE及考马斯亮蓝染色显示,于损伤同时局部一次性注射不同剂量BoNT/A HC后,某些蛋白表达与单纯损伤组相比明显不同,而与正常组基本一致;双向电泳结果进一步显示,损伤局部注射6μg BoNT/A HC后2 d和20 d时,在不同等电点及不同蛋白分子量水平上,有10余种蛋白表达与单纯损伤组明显不同,呈向正常转化的趋势。结论:大鼠脊髓损伤局部注射BoNT/A HC一定时间可影响损伤局部蛋白表达谱的变化,这种变化呈现由损伤造成的蛋白表达变化被转向正常的趋势。

AIM：To observe the effect of botulinum neurotoxin type A heavy chain（ BoNT/A HC） on the pattern of spinal protein expression by intrathecal injection after spinal cord injury in rats,and to explore the role of BoNT/A HC intervention in spinal protein expression and some of its mechanisms in nerve regeneration after injury.METHODS：The model of unilateral lumbar spinal cord injury was established.The effects of BoNT/A HC intervention at different doses（ 2 μg,4 μg,6 μg and 8 μg） on the general pattern of protein expression in the spinal cord tissues at the injury site and the cranial part adjacent to the injury site was measured and evaluated by SDS-PAGE and Coomassie brilliant blue staining first,and then by two-dimensional SDS-PAGE.RESULTS：The histological structure of the ipsilateral side of lumbar spinal cord showed obvious destruction and degradation,mainly affecting both gray and white matter of the left side of the cord.The result of SDS-PAGE with Coomassie brilliant blue staining from injured spinal cord tissue displayed that the expression of some proteins after one-time BoNT/A HC treatment appeared obviously different from that without BoNT/A HC treatment.Moreover,the pattern of the protein expression affected by BoNT/A HC was similar to that of the normal spinal cord.The more detail information from two-dimensional SDS-PAGE indicated that more than 10 proteins with different molecular weight and isoelectronic points were differentially expressed at day 2 and day 20 after local injection of 6 μg BoNT/A HC.This altered expression actually appeared a tendency toward the pattern shown in normal group.CONCLUSION：The immediate application of BoNT/A HC at the injury site after unilateral lumbar spinal cord injury is able to affect the pattern of local protein expression.The altered protein expression by injury could be reversed back to normal or approximately normal by local BoNT/A HC administration.