Li Heng, Wu Wutian
School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, the University of Hong Kong, L1-39, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China.
State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
Eur J Neurosci. 2017 Jul;46(1):1650-1662. doi: 10.1111/ejn.13585. Epub 2017 May 19.
A spinal root avulsion injury disconnects spinal roots with the spinal cord. The rampant motoneuron death, inhibitory CNS/PNS transitional zone (TZ) for axonal regrowth and limited regeneration speed together lead to motor dysfunction. Microtubules rearrange to assemble a new growth cone and disorganized microtubules underline regeneration failure. It has been shown that microtubule-stabilizing drug, Epothilone B, enhanced axonal regeneration and attenuated fibrotic scaring after spinal cord injury. Here, we are reporting that after spinal root avulsion+ re-implantation in adult rats, EpoB treatment improved motor functional recovery and potentiated electrical responses of motor units. It facilitated axons to cross the TZ and promoted more and bigger axons in the peripheral nerve. Neuromuscular junctions were reformed with better preserved postsynaptic structure, and muscle atrophy was prevented by EpoB administration. Our study showed that EpoB was a promising therapy for promoting axonal regeneration after peripheral nerve injury.
脊髓神经根撕脱伤会使脊髓神经根与脊髓断开连接。运动神经元的大量死亡、轴突再生的抑制性中枢神经系统/外周神经系统过渡区（TZ）以及有限的再生速度共同导致运动功能障碍。微管重新排列以组装新的生长锥，而紊乱的微管是再生失败的原因。研究表明，微管稳定药物埃坡霉素B（Epothilone B）可增强脊髓损伤后的轴突再生并减轻纤维化瘢痕形成。在此，我们报告，在成年大鼠脊髓神经根撕脱并重新植入后，埃坡霉素B治疗改善了运动功能恢复并增强了运动单位的电反应。它促进轴突穿过过渡区，并在外周神经中促进更多且更粗的轴突生长。神经肌肉接头得以重新形成，突触后结构保存得更好，并且通过给予埃坡霉素B可防止肌肉萎缩。我们的研究表明，埃坡霉素B是促进外周神经损伤后轴突再生的一种有前景的治疗方法。
