ARHGEF9基因突变可导致早期婴儿型癫痫性脑病，目前已知的主要致病机制为其编码的CB蛋白功能受损，从而影响突触后膜抑制性受体内桥尾蛋白支架的组装和定位，但无法解释该基因不同结构域突变患者癫痫临床表现的显著异质性。课题组前期研究发现ARHGEF9基因DH结构域突变患者癫痫症状相对严重，进一步实验提示DH结构域突变可导致mTOR信号通路的异常激活。据此，提出该基因DH结构域突变通过mTOR信号通路的过度激活作用参与到严重癫痫性脑病过程中的假设。本项目拟通过建立体外细胞模型及mTOR信号通路异常激活的子宫电穿孔小鼠模型，研究DH结构域突变影响mTOR信号通路的机制；深入探索异常激活的mTOR信号通路对神经细胞及突触相关功能的影响，以期阐明不同结构域突变影响神经系统并导致不同严重程度癫痫的潜在机制；同时利用mTOR抑制剂进行治疗研究的探索，为癫痫性脑病患者的精准诊疗提供理论依据。

Mutations in ARHGEF9 gene leads to early infantile epilepsy encephalopathy. Major pathogenic mechanism currently available is impaired function of collybistin protein encoded by ARHGEF9, which affects the assembly and localization of gephyrin scaffolds in the postsynaptic membrane inhibitory receptors. However, the mechanism under significant heterogeneity of epilepsy among patients with mutations located in different domain remains unknown. In our previous study, we found that patients with mutations in the DH domain of the ARHGEF9 gene had relatively severe epilepsy symptoms, and further experiments suggested that DH domain mutation could abnormally activate mTOR signaling pathway. Therefore, the hypothesis that the DH domain mutation of the gene is involved in the process of severe epileptic encephalopathy through the over activation of mTOR signaling pathway is proposed. In this project, we intend to establish in vitro cell model and uterine electroporation mouse model with abnormal activation of mTOR signaling pathway to study the mechanism of DH domain mutation affecting mTOR signaling pathway, and further explore the effect of abnormal activation of mTOR signaling pathway on nerve cells and synaptic function, so as to clarify the potential mechanism of different domain mutations affecting nervous system and leading to epilepsy of different severity. At the same time, exploration of therapeutic research using mTOR inhibitors will be carried out, and provide theoretical basis for accurate diagnosis and treatment of patients with epilepsy encephalopathy.