12月12日在线发表在国际著名期刊《自然—神经科学》(Nature Neuroscience)上,浙江大学医学院神经科学研究所李晓明教授课题组的一项研究结果"Neuregulin 1 regulates excitability of fast-spiking neurons through Kv1.1 and acts in epilepsy"称Neuregulin1/ErbB4是精神分裂症的易感基因。
俗称“羊角风”、“羊痫风” 的癫痫,医学界公认这是大脑神经元突发性异常放电造成的。是什么导致神经元的放电“刹不住车”?李晓明教授课题组的这项研究为此提供了新的回答。
癫痫是人群中发病率较高的一种疾病,影响总人口的大约1%,中国约有一千万患者,目前,经过现有的抗癫痫药物治疗,仍有大约30%的患者不能控制。对于药物不能控制的癫痫目前多采取手术治疗,而适合手术的患者只占一小部分。因此,寻找有效和安全的治疗药物是生物医学重要的目标之一。
现有的大量研究表明,Neuregulin1/ErbB4是精神分裂症的易感基因,李晓明教授的课题组在研究这对基因的过程中,“意外”地发现它们对抑制性神经元兴奋性有调节作用。“这令我们很兴奋。”李晓明介绍,大脑皮层神经元主要由兴奋性神经元和抑制性神经元组成,就像“油门”和“刹车”,双方在正常情况下保持平衡状态。如果“刹车”功能受损,大脑内兴奋性和抑制性神经环路就会失去平衡,引起大脑异常放电,导致癫痫发生。
接下来的研究表明,抑制性神经元上的ErbB4受体可以影响神经元的活性。神经调节素Neuregulin1通过结合ErbB4受体,增加“刹车”的活性。“如果ErbB4受体异常,很可能会导致‘刹车’失灵。”李晓明介绍。
论文第一作者,课题组成员之一李可心博士说,这一研究不但在基因敲除小鼠实验上进行了验证,还由本论文的共同作者、浙江大学医学院附属第二医院神经外科的张建明和朱君明主任医师在癫痫患者组织标本中得到了验证。“NRG和它的受体ErbB4可能是癫痫的易感基因,这不仅为探索癫痫抑制药物的新型有效分子“靶标”提供了研究方向,而且还为治疗以神经元兴奋性改变为基础的脑疾病的新药筛选提供了研究基础。”李晓明说。(生物谷bioon.com)
延伸阅读:
长时间用手机可能诱发癫痫
Steroid:青阳参对难治性癫痫有效
葛兰素癫痫药物获欧盟上市批准
doi:10.1038/nn.3006
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Neuregulin 1 regulates excitability of fast-spiking neurons through Kv1.1 and acts in epilepsy
Ke-Xin Li; Ying-Mei Lu; Zheng-Hao Xu; Jing Zhang; Jun-Ming Zhu; Jian-Ming Zhang; Shu-Xia Cao; Xiao-Juan Chen; Zhong Chen; Jian-Hong Luo; Shumin Duan; Xiao-Ming Li
Dysfunction of fast-spiking, parvalbumin-positive (FS-PV) interneurons is implicated in the pathogenesis of epilepsy. ErbB4, a key Neuregulin 1 (NRG1) receptor, is mainly expressed in this type of interneurons, and recent studies suggest that parvalbumin interneurons are a major target of NRG1-ErbB4 signaling in adult brain. Thus, we hypothesized that downregulation of NRG1-ErbB4 signaling in FS-PV interneurons is involved in epilepsy. We found that NRG1, through its receptor ErbB4, increased the intrinsic excitability of FS-PV interneurons. This effect was mediated by increasing the near-threshold responsiveness and decreasing the voltage threshold for action potentials through Kv1.1, a voltage-gated potassium channel. Furthermore, mice with specific deletion of ErbB4 in parvalbumin interneurons were more susceptible to pentylenetetrazole- and pilocarpine-induced models of epilepsy. Exogenous NRG1 delayed the onset of seizures and decreased their incidence and stage. Moreover, expression of ErbB4, but not ErbB2, was downregulated in human epileptogenic tissue. Together, our findings suggest that NRG1–ErbB4 signaling contributes to human epilepsy through regulating the excitability of FS-PV interneurons. ErbB4 may be a new target for anticonvulsant drugs in epilepsy.