中国神经再生研究(英文版) ›› 2022, Vol. 17 ›› Issue (1): 91-92.doi: 10.4103/1673-5374.314298

• 观点:脑损伤修复保护与再生 • 上一篇    下一篇

卒中和其他神经元损伤后通过环磷酸腺苷内化的Nogo-A受体可克服轴突生长抑制剂

  

  • 出版日期:2022-01-05 发布日期:2021-09-18

Nogo-A receptor internalization by cyclic adenosine monophosphate in overcoming axonal growth inhibitors after stroke

Rayudu Gopalakrishna*, Charlotte Lin, Mark S. Kindy, William J. Mack   

  1. Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA (Gopalakrishna R, Lin C) 
    Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA (Mack WJ)  
    Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA (Kindy MS)
  • Online:2022-01-05 Published:2021-09-18
  • Contact: Rayudu Gopalakrishna, PhD, rgopalak@usc.edu.
  • Supported by:
    This work was supported by NINDS, NIH NS116720 (to RG and WJM).

摘要:

Neural Regen Res Nogo-A受体内化作用可克服轴突生长抑制剂并加强卒中和其他神经元损伤后的功能恢复

   目前还没有药物可用于卒中和其他神经损伤(如创伤性脑损伤和脊髓损伤)的康复。神经功能恢复需要轴突再生,轴突再生受到多种轴突生长抑制剂的抑制,如Nogo-A、髓鞘相关糖蛋白、少突胶质细胞髓鞘糖蛋白和硫酸软骨素蛋白多糖等。

   细胞内环磷酸腺苷克服了髓鞘引起的神经元生长抑制,改善了神经元损伤后的功能恢复,可能通过诱导特定基因的转录激活来阻断轴突生长抑制剂的作用。

    最近的研究证明各种细胞内环磷酸腺苷升高剂诱导细胞表面相关NgR1的快速内化。NgR1的内化依赖于由环磷酸腺苷直接激活的交换蛋白,并且独立于蛋白激酶aNgR1脱敏神经元细胞内化为Nogo-66诱导的神经突起生长锥塌陷。几种生理性药物和天然产物具有提高细胞内环磷酸腺苷的神经保护和神经生成能力。推测这些药物可能诱导NgR1内化,以克服轴突生长抑制剂,促进中风和其他神经损伤后的功能恢复。一些天然产物,如绿茶多酚、白藜芦醇、大豆苷元和肌苷,具有治疗卒中、创伤性脑损伤和脊髓损伤的潜力。所有这些药物都能诱导神经元环磷酸腺苷的升高,推测这些升高环磷酸腺苷的药物也能诱导NgR1内化。

    来自美国南加州大学凯克医学院的Rayudu Gopalakrishna团队认为腺苷酸环化酶和磷酸二酯在神经元内有几种不同定位的同工酶。这可能导致环磷酸腺苷的局部产生和NgR1在神经元表面特定部位的表达改变,从而导致轴突向特定方向生长的减少或增加。与这种生理调节不同,环磷酸腺苷通路的持续药理性全局激活可导致认知能力下降、过度兴奋和痛觉过敏。然而,通过选择合适的天然产物或同功酶特异性磷酸二酯抑制剂,局部刺激NgR1内化所必需的环磷酸腺苷-交换蛋白系统是可能的。通过这种方法,神经再生可以实现,同时尽量减少神经毒性。神经元不仅受到轴突生长抑制物等细胞外信号的影响,而且能够自我调节对轴突生长抑制物的敏感性,这是由神经元内环磷酸腺苷的局部产生所影响的。这一生理过程在药理学上可用于开发药物或利用天然产物来克服轴突生长抑制剂并增强卒中和其他神经损伤(如创伤性脑损伤和脊髓损伤)后的功能恢复。

    文章在《中国神经再生研究(英文版)》杂志2022 1 1 期发表。

https://orcid.org/0000-0002-0398-3166 (Rayudu Gopalakrishna)

Abstract: Currently, there are no clinically proven drugs for recovery from stroke and other neuronal injuries such as traumatic brain injury and spinal cord injury. Recovery therapy requires axonal regeneration, which is inhibited by diverse axonal growth inhibitors, such as Nogo-A, myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMgp), and chondroitin sulfate proteoglycans (CSPGs) (Chaudhry and Filbin, 2007; Carmichael, 2010; Schwab and Strittmatter, 2014). A cell-surface receptor for Nogo-A, NgR1, mediates the inhibitory action of not only Nogo-A but also other axonal inhibitors (MAG, OMgp, and CSPGs) as well. Intracellular cyclic adenosine monophosphate (cAMP) overcomes neuronal growth inhibition caused by myelin and improves functional recovery from neuronal injuries (Chaudhry and Filbin, 2007). It may block the actions of axonal growth inhibitors by inducing a transcriptional activation of specific genes.  In some cases, cAMP rapidly prevents axonal growth inhibitors from acting through an unknown mechanism (Murray and Shewan, 2008).