中国神经再生研究(英文版) ›› 2025, Vol. 20 ›› Issue (7): 2095-2107.doi: 10.4103/NRR.NRR-D-23-01845

• 原著:周围神经损伤修复保护与再生 • 上一篇    下一篇

聚乙二醇融合修复横断的大鼠坐骨神经:轴突连续性重建和脊髓感觉神经末梢重组

  

  • 出版日期:2025-07-15 发布日期:2024-11-27

Polyethylene glycol fusion repair of severed rat sciatic nerves reestablishes axonal continuity and reorganizes sensory terminal fields in the spinal cord

Emily A. Hibbard1 , Liwen Zhou2 , Cathy Z. Yang2 , Karthik Venkudusamy2 , Yessenia Montoya2 , Alexa Olivarez2 , George D. Bittner2 , Dale R. Sengelaub1, *   

  1. 1 Program in Neuroscience, Indiana University, Bloomington, IN, USA;  2 Department of Neuroscience, University of Texas at Austin, Austin, TX, USA
  • Online:2025-07-15 Published:2024-11-27
  • Contact: Dale R. Sengelaub, PhD, sengelau@indiana.edu.
  • Supported by:
    This study was supported by the Department of Defense AFIRM III W81XWH-20-2-0029 grant subcontract; Lone Star Paralysis gift, UT POC19-1774-13 grant, Neuraptive Therapeutics Inc. 26-7724-56 grant and National Institutes of Health R01-NS128086 (all to GDB).

摘要:

周围神经损伤会导致远端神经片段迅速退化,使运动和感觉功能丧失。实验使用一种质膜融合剂--聚乙二醇融合大鼠横断坐骨神经的近端和远端轴突紧密贴合的开口端。课题组既往研究显示,通过聚乙二醇融合修复的坐骨神经轴突不会发生瓦勒变性,而且聚乙二醇 融合动物表现出快速(2-6 周内)和广泛的运动恢复。实验为考察聚乙二醇融合对坐骨神经感觉轴突的影响。建立单侧坐骨神经横断或消融损伤大鼠模型,随后在应用或不应用聚乙二醇(阴性对照)的情况下进行了神经修复。聚乙二醇融合修复后立即记录的复合动作电位证实了损伤部位的传导。通过坐骨神经功能指数测试证实了聚乙二醇融合的成功,修复后 35 天开始,聚乙二醇融合修复的大鼠运动功能有所改善。修复后 2-42 天,通过注射麦芽凝集素-辣根过氧化物酶对后爪背侧的感觉传入进行了逆行标记。聚乙二醇融合修复重建了大鼠损伤坐骨神经的轴突连续性。与未修复的动物比较,聚乙二醇融合动物损伤同侧的背角适当区域以及不适当的内外侧和喙尾区域都发现了标记的感觉传入。意想不到的是,在损伤和修复的对侧也观察到了类似的标记感觉传入重组。这种中枢重组可能是 聚乙二醇融合修复后行为恢复得到改善的原因之一,因而聚乙二醇融合修复是用于周围神经损伤修复的潜在方法。周围神经损伤会导致远端神经片段迅速退化,使运动和感觉功能丧失。实验使用一种质膜融合剂--聚乙二醇融合大鼠横断坐骨神经的近端和远端轴突紧密贴合的开口端。课题组既往研究显示,通过聚乙二醇融合修复的坐骨神经轴突不会发生瓦勒变性,而且聚乙二醇 融合动物表现出快速(2-6 周内)和广泛的运动恢复。实验为考察聚乙二醇融合对坐骨神经感觉轴突的影响。建立单侧坐骨神经横断或消融损伤大鼠模型,随后在应用或不应用聚乙二醇(阴性对照)的情况下进行了神经修复。聚乙二醇融合修复后立即记录的复合动作电位证实了损伤部位的传导。通过坐骨神经功能指数测试证实了聚乙二醇融合的成功,修复后 35 天开始,聚乙二醇融合修复的大鼠运动功能有所改善。修复后 2-42 天,通过注射麦芽凝集素-辣根过氧化物酶对后爪背侧的感觉传入进行了逆行标记。聚乙二醇融合修复重建了大鼠损伤坐骨神经的轴突连续性。与未修复的动物比较,聚乙二醇融合动物损伤同侧的背角适当区域以及不适当的内外侧和喙尾区域都发现了标记的感觉传入。意想不到的是,在损伤和修复的对侧也观察到了类似的标记感觉传入重组。这种中枢重组可能是 聚乙二醇融合修复后行为恢复得到改善的原因之一,因而聚乙二醇融合修复是用于周围神经损伤修复的潜在方法。

https://orcid.org/0000-0002-6166-8632 (Dale R. Sengelaub)

Abstract: Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions; behavioral recovery is typically poor. We used a plasmalemmal fusogen, polyethylene glycol (PEG), to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves. We have previously reported that sciatic nerve axons repaired by PEGfusion do not undergo Wallerian degeneration, and PEG-fused animals exhibit rapid (within 2–6 weeks) and extensive locomotor recovery. Furthermore, our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific, i.e., spinal motoneurons in PEGfused animals were found to project to appropriate as well as inappropriate target muscles. In this study, we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve. Young adult male and female rats (Sprague–Dawley) received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without (Negative Control) the application of PEG. Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site. The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively. At 2–42 days postoperatively, we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase. PEG-fusion repair reestablished axonal continuity. Compared to unoperated animals, labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn, as well as inappropriate mediolateral and rostrocaudal areas. Unexpectedly, despite having intact peripheral nerves, similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair. This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair, supporting the use of this novel repair methodology over currently available treatments.

Key words: axotomy,  dorsal horn,  peripheral nerve injury,  plasticity,  polyethylene glycol (PEG),  sciatic nerve,  sensory terminals,  wheat germ agglutinin horseradish peroxidase