C3 exoenzyme lacks effects on peripheral axon regeneration in vivo
C3 exoenzyme lacks effects on peripheral axon regeneration in vivo
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DOI：
10.1111/jns5.12004
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发表时间：
2013-03-01
影响因子：
3.8
通讯作者：
Klimaschewski, Lars
中科院分区：
文献类型：
--
作者：
Auer, Maria;Allodi, Ilary;Klimaschewski, Lars
外周神经损伤触发脊髓运动和外周感觉神经元中的小GTdR RhoA的激活。C3转移酶是肉毒梭菌产生的一种胞外酶，通过ADP-核糖基化使RhoA失活，已成功应用于中枢神经系统（CNS）损伤模型，以促进功能和形态学上的再生。到目前为止，尚未证明C3 bot是否也对外周轴突再生产生积极影响。在器官型脊髓制备，C3 bot减少轴突生长的运动神经元，而没有影响感觉轴突生长的背根神经节（DRG）外植体观察。无酶活性的C3 E174 Q在两种培养模型中均无效。脊髓切片表现出显着增加，小胶质细胞/巨噬细胞的治疗后，C3 bot的轴突生长的抑制表明炎症组分。然后将C3 bot或C3 E174 Q施加到大鼠坐骨神经横断后植入的管道中。通过电生理学、伤害感受和步行轨迹测试进行的功能评价未显示出活性或突变型C3 E174 Q组之间的任何显著差异。再生神经的透射电子显微镜显示，术后6周有髓和无髓轴突的数量没有显着差异。与CNS相比，RhoA的功能意义在促进生长的环境中的神经再生期间可能是有限的。
Peripheral nerve injury triggers the activation of the small GTPase RhoA in spinal motor and peripheral sensory neurons. C3 transferase, an exoenzyme produced by Clostridium botulinum that inactivates RhoA by ADP-ribosylation, has been successfully applied in central nervous system (CNS) lesion models to facilitate regeneration functionally and morphologically. Until now it has not been demonstrated if C3bot exerts positive effects on peripheral axon regeneration as well. In organotypic spinal cord preparations, C3bot reduced axonal growth of motoneurons, while no effect on sensory axon outgrowth from dorsal root ganglia (DRG) explants was observed. Enzymatically inactive C3E174Q was ineffective in both culture models. Spinal cord slices exhibited a significant increase in microglia/macrophages after treatment with C3bot suggesting an inflammatory component in the inhibition of axon growth. C3bot or C3E174Q were then applied into conduits implanted after transection of the sciatic nerve in rats. Functional evaluation by electrophysiology, nociception, and walking track tests did not show any significant difference between groups with active or mutant C3E174Q. Transmission electron microscopy of the regenerated nerves revealed no significant differences in the number of myelinated and unmyelinated axons 6 weeks after surgery. Compared to the CNS, the functional significance of RhoA may be limited during nerve regeneration in a growth-promoting environment.