氢气通过调控酸敏感离子通道1a功能治疗难治性癫痫持续状态的实验研究

Refractory Status Epilepticus is one of the most life-threatening neurologic emergencies, with the mortality rate of more than 35 percent under the existing anticonvulsant treatments, thus it is urgent to explore a new fast and effective treatment. Recently we found that hydrogen gas could quickly terminate RSE in mice, but this effect was significantly attenuated in acid-sensing ion channel-1a (ASIC1a) knock-out mice. It is well known that ASIC1a was only activated in tissue acidification under pathology, mediating the NMDA receptor-independent Na+/Ca2+ internal flow, which is closely related to cellular excitability. So the above evidence suggests that hydrogen gas may terminate RSE through regulating ASIC1a. Based on the preliminary work, we will firstly investigate the efficiency of different hydrogen gas administrations on RSE models as well as their neuroprotective effects. Then we will observe the changes of expression profile, trafficking and function of ASIC1a in the hippocampus of RSE mice before and after hydrogen gas treatments. Finally, we will further explore the regulation effect of hydrogen on the ASIC1a function in different cells as well as its possible mechanisms by molecular biology and electrophysiological technique. Our study will provide a new, fast and effective treatment for RSE.

难治性癫痫持续状态（RSE）为神经科一急危重症，在现有抗惊厥药物治疗下，死亡率常常超过35%，探索新的快速起效的治疗方法十分迫切。近期我课题组预实验发现氢气可快速终止小鼠RSE，且在酸敏感离子通道1a(ASIC1a)基因敲除小鼠中效果明显减弱，已知ASIC1a仅在病理状态组织酸化后被激活，介导非NMDA受体依赖性的Na+/Ca2+内流，与细胞兴奋性密切相关，提示：氢气可能通过调控脑内ASIC1a功能治疗RSE。藉此我们拟在前期工作基础上，采用经典RSE动物模型，首先探讨不同给氢方式对小鼠RSE的疗效以及神经保护性作用；进而观察RSE模型中氢气治疗前后小鼠海马ASIC1a的表达、磷酸化及膜转运变化，最后采用分子生物学及电生理技术探索氢气对不同细胞上ASIC1a通道功能的调控作用以及可能的机制。本项目的完成将为临床治疗RSE提供一快速有效的新方法。

难治性癫痫持续状态（RSE）为神经科一急危重症，死亡率常常超过35%，探索新的快速起效的治疗方法十分迫切。我课题组前期研究发现氢气可快速终止小鼠RSE，且在酸敏感离子通道1a(ASIC1a)基因敲除小鼠中效果减弱，因此我们假设：氢气可能通过调控脑内ASIC1a功能治疗RSE。为了验证我们首先采用RSE动物模型，探讨不同剂量、不同给氢方式对小鼠RSE的疗效差异；进而观察RSE模型中氢气治疗前后小鼠海马ASIC1a的表达、磷酸化及膜转运变化；最后调控小鼠海马ASIC1a表达，观察氢气对RSE疗效的变化。研究发现：1、在RSE模型中，腹腔注射饱和氢水（Hydrogen-rich saline）可缩短小鼠SE的持续时间；且在给予治疗15分钟内行为学评分较对照组降低；2、Hydrogen-rich saline组小鼠海马CA1区神经元和星形胶质细胞发生坏死及凋亡均明显减少；3、在原代培养神经元的癫痫模型中，Hydrogen-rich saline通过降低SOD2和MAOA表达，减少神经元的死亡；4、Hydrogen-rich saline可上调体外培养神经元ASIC1a的表达，同时通过NR2B来调控ASIC1a的磷酸化水平；5、ASIC1a-/-组小鼠癫痫发作更严重且Hydrogen-rich saline对癫痫持续状态的终止作用在ASIC1a-/-组中降低。综上，本项目证实了氢气对难治性癫痫持续状态的治疗作用，并对其机制进行了探索，为难治性癫痫持续状态的治疗提供了新思路。