南方医科大学学报 ›› 2004, Vol. 24 ›› Issue (04): 361-364.

• •    下一篇

大鼠坐骨神经再生过程中的神经元轴突自噬作用

朴仲贤1, 王万山2, 徐锡金1, 王启伟2, 霍霞1, 韩明虎3, 朴英杰2   

  1. 1. 第一军医大学解剖教研室, 广东, 广州, 510515;
    2. 汕头大学医学院中心实验室, 广东, 汕头, 515041;
    3. 西南大学达拉斯医学中心精神病学部, 德克萨斯, 达拉斯, 75390
  • 出版日期:2004-04-20 发布日期:2004-04-20
  • 基金资助:
    基金项目:Supported by National Natural Science Foundation of China(30300191)
    作者简介:PIAO Zhong-xian,M.Med,E-mail:piaozs@stu.edu.cn

Autophagy of neuron axon during regeneration of rat sciatic nerves

PIAO Zhong-xian1, WANG Wan-shan2, XU Xi-jin1, WANG Qi-wei2, HUO Xia1, HAN Ming-hu3, PIAO Ying-jie2   

  1. 1. 第一军医大学解剖教研室, 广东, 广州, 510515;
    2. 汕头大学医学院中心实验室, 广东, 汕头, 515041;
    3. 西南大学达拉斯医学中心精神病学部, 德克萨斯, 达拉斯, 75390
  • Online:2004-04-20 Published:2004-04-20

摘要: 目的 探讨大鼠坐骨神经变性轴突清除中的自噬作用。方法 横切大鼠坐骨神经制作Wallerian变性模型,造模后不同时间点取远断端组织行电镜结构观察和酸性磷酸酶(AcPase)活性检测。结果 坐骨神经横切后轴突发生变性,主要变化为术后第5小时~2天轴质肿胀,轴突与髓鞘分离,术后第4天轴质浓缩,轴突与髓鞘完全分离形成游离轴突体。术后初期变性轴突主要形成大小不等的空泡,后期轴突与髓鞘完全分离并形成较大的游离轴突体,轴突体外包一层轴突膜是神经元细胞膜的延续,轴突体轴质浓缩,含大量各级自噬泡和纵横交错的神经丝、微管和微丝。经酸性磷酸酶(AcPase)染色证实自噬泡均呈AcPase阳性,第7天后轴突体被降解吸收,形成的空腔内偶见巨噬细胞。结论 大鼠坐骨神经再生过程中变性轴突的清除主要靠轴突自身的自噬和施万细胞吞噬机制,而巨噬细胞只起辅助作用。

Abstract: Objective To investigate the autophagic clearance of degenerated neuron axon during regeneration of rat sciatic nerves. Methods Wallerian degeneration model was established in rats by sciatic nerve transection. Samples from the distal stump were collected at different time points after the transaction and ultrathin sections prepared for electron microscopic examination and acid phosphatase (AcPase) activity detection. Results Neuron axon degeneration occurred after transection of rat sciatic nerve, presenting predominantly swelling of the axoplasm and separation of the axon from the myelin sheath seen 5 h to 2 d after the transection. On day 4, axoplasm condensation took place and the axons were completely separated from the myelin sheath to form dissociative axon body. Vacuoles of various sizes were identified in the axon in the early stage after operation and later when the axons were completely dissociated from the nerve sheath, larger dissociative axon bodies occurred. The axolemma surrounding the axon body was derived from the neuronal cytomembrane, and the condensed axoplasm contained numerous autophagic vacuoles at all levels along with large number of neurofilaments, microtubules and microfilaments arranged in a crisscross pattern. The autophagic vacuoles exhibited acid phosphatase (AcPase) activities. Since the day 7, the axon bodies were absorbed after degradation and macrophages could be spotted occasionally. Conclusion The degenerated axons were cleared mainly through autophagy during regeneration of rat sciatic nerve and macrophages only assist in this process.

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