Simão Fabrício, Zamin Lauren L, Frozza Rudimar, Nassif Melissa, Horn Ana Paula, Salbego Christianne G
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS, Brazil.
Neurol Res. 2009 Dec;31(10):1044-8. doi: 10.1179/174313209X385671. Epub 2009 Jul 2.
Brain ischemia results in cellular degeneration and loss of brain function. Oxcarbazepine (OXC), one of the newer antiepileptic drugs, has been demonstrating its efficacy on wide spectrum neurological disorders. In this paper, we investigated the neuroprotective profile of OXC in an in vitro model of ischemia, which consists in the exposure of organotypic hippocampal slice cultures to oxygen and glucose deprivation.
OXC (30 microM) was added to the medium before and/or during and/or after the oxygen and glucose deprivation induction. Cell death was quantified by propidium iodide uptake measurement. Immunoblotting was used to detect the phosphorylation of Akt.
Our results showed a decrease in propidium iodide incorporation when OXC was added before oxygen and glucose deprivation, suggesting a neuroprotective effect. This effect was prevented when cultures were previously treated with LY294002, an inhibitor of phosphoinositide-3-kinase (PI3K) pathway. We also analysed the effect of OXC on Akt phosphorylation. Immunoblotting revealed that OXC did not induce any change in phosphorylation/activation of Akt.
Our results reinforce the neuroprotective effect of OXC and add some evidence that its mechanism may involve the PI3K pathway, suggesting that such effect could be upstream Akt. This indicates that with respect to OXC neuroprotective, Akt may not play a crucial role in determining cell survival.
脑缺血会导致细胞变性和脑功能丧失。奥卡西平（OXC）是一种新型抗癫痫药物，已在多种神经系统疾病中显示出疗效。在本文中，我们在缺血的体外模型中研究了奥卡西平的神经保护作用，该模型是将海马脑片培养物暴露于缺氧缺糖环境。
在缺氧缺糖诱导之前和/或期间和/或之后，向培养基中添加奥卡西平（30微摩尔）。通过测量碘化丙啶摄取量来定量细胞死亡。免疫印迹法用于检测Akt的磷酸化。
我们的结果显示，在缺氧缺糖之前添加奥卡西平后，碘化丙啶掺入量减少，表明具有神经保护作用。当培养物预先用磷酸肌醇-3-激酶（PI3K）途径抑制剂LY294002处理时，这种作用被阻断。我们还分析了奥卡西平对Akt磷酸化的影响。免疫印迹显示，奥卡西平不会诱导Akt的磷酸化/激活发生任何变化。
我们的结果强化了奥卡西平的神经保护作用，并提供了一些证据表明其机制可能涉及PI3K途径，提示这种作用可能在Akt上游。这表明在奥卡西平的神经保护方面，Akt可能在决定细胞存活中不发挥关键作用。
