中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2015, Vol. 10 ›› Issue (2): 225-229.doi: 10.4103/1673-5374.152375

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

脊髓损伤后神经再生的障碍：Nogo-A随时间变化的动态表达

  

  • 收稿日期:2014-09-17 出版日期:2015-02-17 发布日期:2015-02-17
  • 基金资助:

    江苏省自然科学基金（no.bk2011180），江苏省普通高校研究生科研创新项目（no.cxzz13-0614），江苏省普通高校研究生科研创新项目（no.cxzz12-0609）

Nogo-A expression dynamically varies after spinal cord injury

Jian-wei Wang 1, Jun-feng Yang 1, Yong Ma 2, Zhen Hua 2, Yang Guo 1, Xiao-lin Gu 2, Ya-feng Zhang 1   

  1. 1 Wuxi Hospital of Traditional Chinese Medicine, Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine, Wuxi, Jiangsu Province, China
    2 Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
  • Received:2014-09-17 Online:2015-02-17 Published:2015-02-17
  • Contact: Ya-feng Zhang, Ph.D., orthozhang@sina.com.
  • Supported by:

    This study was financially supported by a grant from the Natural Science Foundation of Jiangsu Province, No. BK2011180; Ordinary University Graduate Student Scientific Research Innovation Projects of Jiangsu Province, No. CXZZ13-0614, CXZZ12-0609.

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摘要：

目前普遍认为Nogo-A可抑制神经元轴突再生，但脊髓组织损伤后神经再生的障碍的具体机制尚不清楚，实验拟进一步揭示，脊髓损伤后Nogo-A随时间表达的变化。以重物自由落体打击法建立脊髓损伤模型大鼠，通过免疫组化及Western Blot检测大鼠脊髓组织中Nogo-A免疫阳性反应及蛋白的表达，以荧光定量PCR检测Nogo-A mRNA表达，观察大鼠脊髓损伤后神经生长抑制因子Nogo-A在脊髓组织中的动态表达变化。结果发现，Nogo-A mRNA、蛋白和免疫阳性反应的变化趋势基本一致，脊髓损伤后24 h，Nogo-A mRNA、蛋白和免疫阳性反应表达下降，3 d后下降至最低，7 d后迅速上升达到高峰，至14 d再逐渐下降。结果揭示，大鼠脊髓损伤后，Nogo-A蛋白在早期一过性下降后可持续保持高水平表达，这可能是造成脊髓损伤后中枢神经系统神经再生困难的重要原因之一。

关键词: 神经再生, 脊髓损伤, 挫伤, Nogo-A蛋白, 受体, 轴突生长, 免疫组化, 荧光定量PCR, 蛋白质印迹法, 大鼠

Abstract:

The mechanism involved in neural regeneration after spinal cord injury is unclear. The myelin-derived protein Nogo-A, which is specific to the central nervous system, has been identified to negatively affect the cytoskeleton and growth program of axotomized neurons. Studies have shown that Nogo-A exerts immediate and chronic inhibitory effects on neurite outgrowth. In vivo, inhibitors of Nogo-A have been shown to lead to a marked enhancement of regenerative axon extension. We established a spinal cord injury model in rats using a free-falling weight drop device to subsequently investigate Nogo-A expression. Nogo-A mRNA and protein expression and immunoreactivity were detected in spinal cord tissue using real-time quantitative PCR, immunohistochemistry and western blot analysis. At 24 hours after spinal cord injury, Nogo-A protein and mRNA expression was low in the injured group compared with control and sham-operated groups. The levels then continued to drop further and were at their lowest at 3 days, rapidly rose to a peak after 7 days, and then gradually declined again after 14 days. These changes were observed at both the mRNA and protein level. The transient decrease observed early after injury followed by high levels for a few days indicates Nogo-A expression is time dependent. This may contribute to the lack of regeneration in the central nervous system after spinal cord injury. The dynamic variation of Nogo-A should be taken into account in the treatment of spinal cord injury. 

Key words: nerve regeneration, spinal cord injury, contusion, Nogo-A, axon growth, immunohistochemistry, fluorescent quantitative PCR, neural regeneration