中国神经再生研究(英文版) ›› 2016, Vol. 11 ›› Issue (1): 79-80.doi: 10.4103/1673-5374.169635

• 观点:脑损伤修复保护与再生 • 上一篇    下一篇

益智药可重建大脑神经架构

  

  • 收稿日期:2015-10-15 出版日期:2016-01-15 发布日期:2016-01-15

Nootropics with potential to (re)build neuroarchitecture

Kyoko Koshibu   

  1. Neuroscience Therapeutic Area, UCB Pharma SA, Braine-l’Alleud,Belgium
  • Received:2015-10-15 Online:2016-01-15 Published:2016-01-15
  • Contact: Kyoko Koshibu, Ph.D., Kyoko.koshibu@ucb.com or Kyoko_koshibu@yahoo.com.

摘要:

以往益智药物主要用于症状缓解,而不是抑制或修复已经损伤的神经组织。例如美金刚,旨在抑制beta淀粉样蛋白诱导的兴奋性中毒。在研究新的治疗方法之中,研究人员越来越多将注意力转移到了解现有益智药物对神经发生和轴突形成的细胞作用,这是大脑可塑性和再生长过程中神经网络形成的中心过程,并可以确定其对神经架构形成的潜在作用,研究表明选择性促认知化合物确实具有这样的性质。文章表明,乙酰胆碱酯酶抑制剂多奈哌齐可以显著促进神经轴突向外生长,乙酰胆碱酯酶抑制剂的细胞效应可能包括刺激神经发生,因为胆碱能受体可在神经祖细胞中表达并被耦合到细胞增殖之中。然而,他们的研究结果也表明多奈哌齐促进轴突形成的作用可能在缺乏他克林的条件下不同于乙酰胆碱酯酶效果。特别是多奈哌齐结合sigma1受体以高亲和力在低纳摩尔范围内可作为有效的sigma1受体的激动剂。

Abstract:

Development of effective treatments for neurodegenerative disorders is a clinical conundrum that has puzzled many researchers. Currently available drugs target symptomatic relief rather than suppressing, ceasing or repairing the devastating neural damages. For Alzheimer’s disease, there are two classes of procognitive compounds that are approved as a treatment of the disease. Acetylcholinesterase (AChE) inhibitors, such as tacrine, donepezil, galantamine and rivastigmine, inhibit the hydrolysis of acetylcholine and elevate the acetylcholine neurotransmitter level. The other class of drug is N-methyl-D-aspartate (NMDA) receptor antagonists, such as memantine, intended to suppress ?-amyloid induced excitotoxicity. These compounds have produced only modest improvements in cognitive and behavioral symptoms in some Alzheimer’s patients. Thus, tremendous efforts are being made to discover and develop more effective treatments for Alzheimer’s disease. In the midst of the intense investigation for new treatments, there have been increasing effort to understand the cellular effects of the existing nootropic compounds on neurogenesis and neuritogenesis, a central process for the formation of neural networks during brain plasticity and (re)growth, to determine their potential for molding neuroarchitecture. Interestingly, studies have shown that selective procognitive compounds indeed possess such properties. We have recently shown that an AChE inhibitor donepezil can significantly promote neurite outgrowth in a primary cortical culture system. The cellular effects of AChE inhibitors conceivably include stimulation of neurogenesis, because cholinergic receptors are expressed on neuronal progenitors and are coupled to cell proliferation. However, the actual molecular targets of donepezil that promotes neuritogenesis may differ from AChE in light of the lack of effect of tacrine in our study. Donepezil is known to have various other targets in addition to AChE. In particular, donepezil binds sigma1 receptors with high affinity at a low nanomolar range in vitro and behave as an effective sigma1 receptor agonist. Neuroprotective effects of donepezil have been reported to involve a sigma1 interaction in a mouse model and in rodent cortical culture. The authors have reported that donepezil and sigma1 receptor agonist Pre-084 provide a complete neuroprotection in mice treated with β-amyloid peptide 25–35 while only a partial neuroprotection can be achieved with AChE inhibitor tacrine. Furthermore, pre-administration of the sigma1 receptor antagonist BD1047 or in vivo antisense probe treatment blocks the memory-enhancing effect of donepezil. These studies suggest that the procognitive and neuroprotective activities of donepezil are at least partially mediated by sigma1 receptor.