臂丛损伤再生中GAP-43 mRNA及其蛋白的表达

目的：分析臂丛损伤后脊髓前角运动神经元表达GAP-43 mRNA及其蛋白的变化规律，探讨神经损伤再生的机制。方法：建立3种臂丛损伤模型：右C₇前根撕脱（A组）；右C₇前根撕脱＋同侧C5-T₁后根断离（B组）；右C₇前根撕脱+右C₅C₆间脊髓半横断（C组）。用荧光定量RT-PCR方法检测术后14 d时 C₇前角GAP-43 mRNA的表达量。用免疫组化方法检测术后1、 3、 7、14 d脊髓前角GAP-43免疫阳性运动神经元的表达。结果：对照组C₇前角GAP-43 mRNA呈低表达，损伤组GAP-43 mRNA表达显著上调。损伤组术后1 d、3 d时均未见C₇前角 GAP-43免疫阳性神经元，术后7 d各损伤组GAP-43免疫阳性神经元开始出现，14 d时免疫阳性神经元数目达到高峰。3组间比较，C组表达量最高，B组最低，A组居中。结论：臂丛损伤诱导运动神经元GAP-43 mRNA及其蛋白表达上调，GAP-43合成增加是神经元蛋白重组所致，与轴索再生和神经功能重建有关。

Expression of GAP-43 mRNA and protein following brachial plexus avulsion injury

AIM:To investigate the expression of GAP-43 mRNA and protein of the motor neurons in spinal cord following the brachial plexus avulsion injury.METHODS: In the present study,three kinds of models of brachial plexus avulsion injury were made: right C7 anterior root avulsion(group A),C7 anterior root avulsion with right C5-T1 posterior roots breaking(group B),right C7 anterior root avulsion with hemi-transect between C5 and C6 segment of spinal cord(group C).The expression of GAP-43 mRNA in anterior horn of spinal cord was detected at 14 days after operation by SYBR green quantification RT-PCR technique.The amounts of GAP-43 positive neurons in spinal cord were detected at 1,3,7 and 14 days after operation by immunohistochemistry technique.RESULTS: In control group,the expression of GAP-43 mRNA was very low in anterior horn.By 14 days after operation,the expression of GAP-43 mRNA was evidently up-regulated compared with control group.GAP-43 positive neuron was observed in control group at 1st day and 3rd day after operation.GAP-43 positive neurons appeared at 7th day and peaked at 14th day after operation.The expression of GAP-43 mRNA and protein were maximum in group C,group B was the lowest.CONCLUSION: The expression of GAP-43 mRNA and GAP-43 protein were up-regulated following brachial plexus injury.The expression of GAP-43 protein results from the recombination of proteins.GAP-43 is closely related to the axon regeneration and functional reconstruction.