中国神经再生研究(英文版) ›› 2016, Vol. 11 ›› Issue (2): 210-211.doi: 10.4103/1673-5374.177713

• 观点:脊髓损伤修复保护与再生 • 上一篇    下一篇

酪蛋白激酶1δ及复合物形成在损伤脊髓轴突生长中的作用

  

  • 收稿日期:2015-11-16 出版日期:2016-02-15 发布日期:2016-02-15
  • 基金资助:

    该研究得到美国国立卫生研究院NS056991与NS067289基金资助。

Casein kinase signaling in axon regeneration

Nagi G. Ayad, Jae K. Lee, Vance P. Lemmon   

  1. The Center for Therapeutic Innovation, The Miami Project to Cure Paralysis, Department of Psychiatry and Behavioral Sciences,University of Miami, Miami, FL, USA (Ayad NG)
    The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami, Miami, FL, USA (Lee JK, Lemmon VP)
  • Received:2015-11-16 Online:2016-02-15 Published:2016-02-15
  • Contact: Nagi G. Ayad, Ph.D., nayad@miami.edu.
  • Supported by:

    We thank all members of the Center for Therapeutic Innovation and the Miami Project to Cure Paralysis for helpful suggestions.This work was supported by NS056991 and NS067289 to NGA.

摘要:

最近的研究表明,细胞周期途径可能含有治疗神经创伤的重要靶标。其中的一个例子是,研究发现脊椎动物细胞周期的蛋白水解途径在完全分化的细胞中仍有活动,而这些细胞周期在神经元中也同样存在。我们早已知道泛素连接酶,即后期促进复合物在细胞周期中需要通过M和G1期进行发展,并且也活跃在完全分化的不再分裂的神经元中。一些研究表示后期促进复合物在完全分化的神经元中起到抑制轴突生长的作用。因此,减少小脑颗粒细胞中后期促进复合物激活因子CDH1可以使轴突生长增强;同样,不可降解的后期促进复合物基底物过表达,如SnoN和Id2也能够起到促进小脑颗粒细胞神经轴突生长的作用。有趣的是,不可降解Id2过表达能够增强再生模型的神经突生长,这表明通过影响它们的降解率,并调节蛋白水平可能是神经创伤临床前模型极具吸引力的治疗方式之一。我们认为除了体外研究酪蛋白激酶1δ,在脊髓损伤模型中确定酪蛋白激酶1δ抑制剂是否能够体内降低神经突生长也是至关重要的。鉴于已证实的酪蛋白激酶1δ对神经突生长的体外作用,可以推测酪蛋白激酶1δ抑制剂应该可以减弱突起生长。然而,脊髓损伤后神经突生长也受炎症影响。有研究表明,抑制星形胶质细胞中的炎症可以减少炎症并增强脊髓损伤后的神经突向外生长。因此,对于酪蛋白激酶1δ在脊髓损伤后促进炎症的可能作用,或许能够表明酪蛋白激酶1δ抑制剂是一种具有吸引力的治疗措施之一。未来的研究将进一步界定酪蛋白激酶1δ在脊髓损伤后促进炎症和突起生长的作用。

Abstract:

Recent studies suggest that cell cycle pathways may contain therapeutic targets important for neurotrauma. An example of this is the finding that the vertebrate cell cycle exploits proteolysis pathways yet these activities persist in fully differentiated cells that have exited the cell cycle such as neurons. We have known for some time that a ubiquitin ligase, the Anaphase-Promoting Complex (APC/C) required for progression through the M and G1 phases of the cell cycle, is also active in fully differentiated neurons that are no longer dividing. Several studies demonstrated roles for APC/C in restraining neurite outgrowth in fully differentiated neurons. Depleting the APC/C activator Cdh1 increased neurite outgrowth in cerebellar granule cells. Similarly, overexpression of nondegradable APC/C substrates such as SnoN and Id2 promoted neurite outgrowth in cerebellar granule cells. Interestingly, nondegradable Id2 overexpression increased neurite outgrowth in a regeneration model, suggesting that modulating protein levels by affecting their degradation rates may be therapeutically attractive in preclinical models of neurotrauma. In addition to in vitro studies with CK1δ it will be important to determine whether CK1δ inhibition reduces neurite outgrowth in vivo in naïve animals but also in models of spinal cord injury. Given the reported role for CK1δ in neurite outgrowth in vitro the prediction is that CK1δ inhibition should reduce neurite outgrowth. However, after spinal cord injury neurite outgrowth is also affected by inflammation. Studies have shown that inhibition of inflammation in astrocytes reduces inflammation and increases neurite outgrowth after SCI. Thus, a possible role for CK1δ in promoting inflammation after SCI may suggest that CK1δ inhibition may be therapeutically attractive. Consistent with this notion is the finding that CK1δ inhibition reduces neuropathic pain after SCI, possibly via reducing inflammation. Future studies will delineate the role of CK1δ in promoting inflammation and neurite outgrowth after SCI. Furthermore, the contribution of APC/C dependent degradation should be analyzed to determine whether it is feasible to simultaneously stimulate APC/C-dependent degradation of CK1δ in inflammatory cells while inhibiting the APC/C-CK1δ interaction in neurons.