Pilocapine alters NMDA receptor expression and function in hippocampal neurons: NADPH oxidase and ERK1/2 mechanisms
Pilocapine alters NMDA receptor expression and function in hippocampal neurons: NADPH oxidase and ERK1/2 mechanisms
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DOI：
10.1016/j.nbd.2011.02.012
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发表时间：
2011-06-01
影响因子：
6.1
通讯作者：
Greenamyre, J. Timothy
中科院分区：
文献类型：
--
作者：
Di Maio, Roberto;Mastroberardino, Pier G.;Greenamyre, J. Timothy
癫痫发生的分子基础仍然不清楚，但反复或长期癫痫发作可导致海马N-甲基D-天冬氨酸受体（NMDAR）化学计量学改变，海马神经元丢失和异常苔藓纤维发芽。使用毒蕈碱受体1（m1 R）激动剂，毛果芸香碱（PILO），在海马细胞培养，我们探讨了早期序列的分子事件发生在24小时内的初始侮辱，并导致癫痫发生过程中改变神经元功能。我们的研究结果表明，PILO诱导的，m1 R介导的，肌醇1，4，5-三磷酸（IP 3）的合成构成了NMDAR超活化和随后的NADPH氧化酶（NOX）活化和NMDAR非依赖性ERK 1/2磷酸化所需的早期，关键的生化事件。NOX活化和ERK 1/2磷酸化共同但不单独地通过上调NR 1和NR 2B亚基诱导NMDAR化学计量的改变。最后，我们证明PILO介导的氧化应激通过半胱氨酸残基的氧化还原调节改变NMDAR功能。与硫醇氧化、NOX活化、ERK 1/2磷酸化和NMDAR上调相关的体外结果在用PILO处理成年大鼠后24小时在体内得到证实。在PILO处理的原代海马神经元中获得的这些结果-并在PILO后的同一时间点在体内证实-提供了对癫痫发生期间早期细胞反应的更好理解，并确定了预防慢性癫痫发展的潜在治疗靶点。(C)2011 Elsevier Inc. All rights reserved.
The molecular basis for epileptogenesis remains poorly defined, but repeated or prolonged seizures can cause altered hippocampal N-methyl D-aspartate receptor (NMDAR) stoichiometry, loss of hippocampal neurons, and aberrant mossy fiber sprouting. Using the muscarinic receptor 1 (m1R) agonist, pilocarpine (PILO), in hippocampal cell cultures we explored the early sequence of molecular events that occur within 24 h of the initial insult and result in altered neuronal function during epileptogenesis. Our findings show that PILO-induced, m1R-mediated, inositol 1,4,5-trisphosphate (IP3) synthesis constitutes an early, crucial biochemical event required for NMDAR hyperactivation and subsequent NADPH oxidase (NOX) activation and NMDAR-independent ERK1/2 phoshorylation. Together, but not separately, NOX activation and ERK1/2 phosphorylation induce alterations in NMDAR stoichiometry through the upregulation of NR1 and NR2B subunits. Lastly, we demonstrated that PILO-mediated oxidative stress alters NMDAR function through the redox modulation of cysteine residues. The in vitro results related to thiol oxidation, NOX activation, ERK1/2 phosphorylation and NMDAR upregulation were confirmed in vivo, 24 h after treatment of adult rats with PILO. These results obtained in PILO-treated primary hippocampal neurons - and confirmed in vivo at the same time-point after PILO - provide a better understanding of the early cellular responses during epileptogenesis and identify potential therapeutic targets to prevent development of chronic epilepsy. (C) 2011 Elsevier Inc. All rights reserved.