轴突起始段异常在DEPDC5相关癫痫的致痫机制研究

DEPDC5相关癫痫（DRE）合并皮质畸形时，对抗痫药物反应差，常进展为难治性癫痫。局部敲除大鼠神经元Depdc5会过度活化mTOR通路导致神经元体积增大和自发癫痫，mTOR抑制剂依维莫司虽可减小突变神经元体积，但未能减少痫样发作；在胚系新皮质Depdc5小鼠中，发现轴突起始段(AIS)标志性蛋白Ankyrin-G （AnkG）异常，可能是其癫痫难以控制的关键点，但该模型长期存活率极低，进一步验证受限。结合胶质细胞在癫痫研究中的新近发现，我们推测只敲除胶质细胞Depdc5可望构建理想的DRE模型；AAV9过表达AnkG调节AIS，有望减少其痫样发作。拟用Aldh1l1-Cre/ERT2构建星形胶质细胞特异的新模型，免疫荧光染色、免疫蛋白印迹、视频脑电图、膜片钳等检验其特点；比较过表达AnkG和依维莫司的疗效差异，以明确AIS异常在DRE癫痫进程中的作用。为DRE研究提供新的模型和治疗思路。

DEPDC5-related epilepsy (DRE) is the common cause of familial focal epilepsy. There is currently no evidence that seizures respond well to one particular antiepileptic drug. In patients with focal cortical dysplasia, the possibility of epilepsy surgery should be explored for refractory epilepsy. We generated a rodent model with hyperactivate mTOR pathway, increased neuron sizes and spontaneous focal seizure by knock-out of Depdc5. Everolimus as mTOR inhibitor rescued these neurons but no significant effect on seizures. Neocortex-specific Depdc5 conditional knockout mice have shortened axon initial segment (AIS) as the marker Ankyrin-G (AnkG) shows, which may be the key process of seizures. However it hasn't be confirmed due to the extremely low survival rate of this model. With the knowledge of glial cells' role in epilepsy, we hypothesize that non-neuronal cells knockout of Depdc5 mouse is an idea DRE model and overexpression of AnkG (AnkG OE) by adeno-associated airus serotype 9 (AAV9) is possible to anti-seizure by protecting AIS. This new model is developed by Aldh1l1-Cre/ERT2. The characteristics are tested by immunofluorescence staining, western blotting, video electroencephalograph and patch clamp with administration of everolimus or AnkG OE, paving the way toward understanding the role of AIS in pathogenesis and developing new model and mechanistic-based therapies for refractory epilepsy in DRE.