Nicotinic acetylcholine receptor-mediated neuroprotection by donepezil against glutamate neurotoxicity in rat cortical neurons
Nicotinic acetylcholine receptor-mediated neuroprotection by donepezil against glutamate neurotoxicity in rat cortical neurons
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DOI：
10.1124/jpet.103.050104
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发表时间：
2003-08-01
影响因子：
3.5
通讯作者：
Akaike, A
中科院分区：
文献类型：
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作者：
Takada, Y;Yonezawa, A;Akaike, A
多奈哌齐是一种有效的和选择性的乙酰胆碱酯酶（AChE）抑制剂，用于治疗阿尔茨海默病。为了阐明多奈哌齐是否显示神经保护作用，除了改善认知缺陷，我们研究了多奈哌齐对谷氨酸诱导的神经毒性的影响，使用大鼠皮层神经元的原代培养。培养物暴露于谷氨酸10分钟，然后与无谷氨酸培养基孵育1小时，导致活力明显丧失，如台盼蓝排除法所测定。谷氨酸神经毒性的预防24小时多奈哌齐预处理浓度依赖性的方式。在AChE抑制剂检查，多奈哌齐和某些AChE抑制剂，如他克林和加兰他敏表现出强大的神经保护作用，虽然毒扁豆碱不影响谷氨酸神经毒性。多奈哌齐的神经保护作用被烟碱型乙酰胆碱受体（nAChR）拮抗剂美加明拮抗，但不被毒蕈碱型乙酰胆碱受体拮抗剂东莨菪碱拮抗。此外，α 4 β 2-神经元nAChR拮抗剂二氢-β-赤藓定和α 7-nAChR拮抗剂甲基甘草次碱均显著拮抗多奈哌齐的作用。接下来，我们研究了多奈哌齐对谷氨酸诱导的细胞凋亡的影响。暴露100 μ M谷氨酸皮质神经元24小时诱导神经元凋亡和核碎裂。多奈哌齐24小时前和24小时期间谷氨酸暴露防止核碎裂和谷氨酸诱导的细胞凋亡。这些结果表明，多奈哌齐不仅通过α 4 β 2-和α 7-nAChR保护皮质神经元免受谷氨酸神经毒性，而且还防止凋亡性神经元死亡。
Donepezil is a potent and selective acetylcholinesterase (AChE) inhibitor developed for the treatment of Alzheimer's disease. To elucidate whether donepezil shows neuroprotective action in addition to amelioration of cognitive deficits, we examined the effects of donepezil on glutamate-induced neurotoxicity using primary cultures of rat cortical neurons. A 10-min exposure of cultures to glutamate followed by a 1-h incubation with glutamate-free medium caused a marked loss of viability, as determined by Trypan blue exclusion. Glutamate neurotoxicity was prevented by 24-h pretreatment of donepezil in a concentration-dependent manner. Among AChE inhibitors examined, donepezil and certain AChE inhibitors such as tacrine and galanthamine showed potent neuroprotective action, although physostigmine did not affect glutamate neurotoxicity. Neuroprotective action of donepezil was antagonized by mecamylamine, a nicotinic acetylcholine receptor (nAChR) antagonist, but not by scopolamine, a muscarinic acetylcholine receptor antagonist. Furthermore, both dihydro-beta-erythroidine, an alpha4beta2-neuronal nAChR antagonist, and methyllycaconitine, an alpha7-nAChR antagonist, each also significantly antagonized the effect of donepezil. Next, we examined the effects of donepezil on glutamate-induced apoptosis. Exposure of 100 muM glutamate to cortical neurons for 24 h induced apoptotic neuronal death and nuclear fragmentation. Donepezil for 24 h before and 24 h during glutamate exposure prevented nuclear fragmentation and glutamate-induced apoptosis. These results suggest that donepezil not only protects cortical neurons against glutamate neurotoxicity via alpha4beta2- and alpha7-nAChRs but also prevents apoptotic neuronal death.