生物钟蛋白CLOCK缺失引发癫痫的机制及其治疗初探

There is no effective treatment that is currently available for intractable epilepsy whose pathogenesis remains largely unclear. Our recently published study on surgical samples from patients with intractable focal epilepsy had demonstrated that the expression of Circadian Locomotor Output Cycles Kaput (CLOCK) was significantly decreased in epileptogenic tissue. We have created a genetically modified mouse model with a selective deletion of CLOCK in excitatory neurons in the cortex (Emx cre; Clock flox/flox）and the animals develop spontaneous seizures, possibly due to the reduction of dendritic spines, and less inhibitory inputs than excitatory inputs in excitatory neurons. In the current study, we propose to use Emx cre; Clockflox/flox mice to study molecular mechanisms of CLOCK regulation by answering three questions: 1) what downstream genes of CLOCK have been affected that lead to the reduction of dendritic spines? 2) what are the changes among different subtypes of inhibitory interneurons regarding their number, morphology and neural circuits? 3) can small molecules that were proved to strengthen the CLOCK signals rescue the defect of neural circuits? We hope our study will provide new insights into the underlining pathogenesis and eventually lead to the development of novel therapeutics for intractable epilepsy.

顽固性癫痫仍缺乏有效的治疗措施，发病机理也尚未完全清楚。我们最近发表的研究发现：生物钟蛋白CLOCK在顽固性癫痫病灶组织中的表达明显降低；并且通过动物模型将小鼠大脑皮质兴奋性神经元的CLOCK基因敲除（Emx cre; Clock flox/flox）后，小鼠有自发性癫痫；其中原因可能是兴奋性神经元的树突棘明显减少，并且其抑制性神经输入的减少多于兴奋性神经输入的减少。本课题将以CLOCK敲除小鼠为动物模型，通过回答以下几个问题来深入研究其中的分子机理。1）哪一些CLOCK的下游基因发生了变化，并且可以引起神经元的树突棘的减少？2）抑制性神经元在亚型、数量、形态和神经环路方面分别有什么变化？3）改善“分子时钟”下游基因表达的小分子是否会逆转CLOCK缺失而引起的神经环路不平衡？该研究希望通过对“分子时钟”CLOCK和神经环路的研究，寻找新的顽固性癫痫的治疗途径。