大鼠脊髓顿挫伤后CRMP-2的表达变化

The expression change of CRMP-2 in rats after spinal cord contusion

目的:观察大鼠脊髓顿挫伤后脑衰反应蛋白2(CRMP-2)在脊髓组织中的分布及基因表达变化。方法:采用Allen's重物法打击SD大鼠制备脊髓顿挫伤模型。采用BBB评分方法评估大鼠后肢运动功能:采用免疫组织化学技术(IHC)观察CRMP-2在损伤脊髓中的定位,实时定量PCR(qRT-PCR)方法观察CRMP-2在大鼠脊髓顿挫伤后的基因表达变化。结果:脊髓顿挫伤后,BBB评分结果表明大鼠后肢运动功能明显下降,在损伤后1d,7 d,14 d,21 d和28 d的BBB评分逐渐恢复,但是仍然低于对照组。免疫组织化学染色结果显示:CRMP-2在脊髓前角运动神经元和神经胶质细胞中广泛表达在脊髓损伤后12 h,3 d,7 d,14 d和28 d,CRMP-2免疫阳性细胞数相比sham组均有明显的减少。定量qRT-PCR结果显示:脊髓顿挫伤后CRMP-2基因表达下降,并持续至术后28 d。结论:脊髓顿挫伤后,CRMP-2大量存在于脊髓前角运动神经元及神经胶质细胞中,在损伤脊髓中的基因表达持续下降。结果提示脊髓顿挫伤后CRMP-2可能影响神经细胞的生长,分化和迁移。

Objective：To observe the gene expression change and location of collapsin response mediator protein-2（CRMP-2） in spinal cord of rats after spinal cord contusion.Methods：The models of spinal cord contusion（cSCI） of SD rats were established according to the Allen＇s method.BBB score was used to evaluate the motor function recovery of hind limbs in rats.qRT-PCR was used to detect the gene expression of CRMP-2,whose location was also examined in spinal cord through immunohistochemistry（IHC）.Results：After spinal cord contusion,motor dysfunction of rats appeared and was followed by recovery at 1 d,2 d,14 d,21 d and 28 d as evaluated by BBB score,but it still could not reach the normal level.Immunohistochemistry showed abundant expression of CRMP-2 in motor neurons and glial cells of spinal ventral horn.CRMP-2 immunopositive cells were located in neurons of anterior horn of spinal cord and astrocytes in spinal cord,whch significantly decreased compared with sham group on 12 h,3 d,7 d,14 d and 28 d post injury.qRT-PCR results showed the down regulation of CRMP-2,which persisted till 28 days post-surgery.Conclusion：CRMP-2 widely exists in the spinal cord anterior horn motor neurons and glial cells and followed by a down regulation of CRMP-2 after cSCI.These results indicate that CRMP-2 may affect the growth,differentiation and migration of nerve cells after cSCI.