携miR-181a外泌体介导的神经元-星形胶质细胞间信息传递在癫痫病理进程中的作用机制研究

Traditional antiepileptic drugs have limited effects by treating neuronal ion channels for epilepsy. The abnormal ability of astrocytes to uptake synaptic glutamate is an important cause of refractory epilepsy, but the cause and mechanism of this process are unclear. Recently, neuronal-astrocyte signaling has been found to be a key mechanism for maintaining glial glutamate uptake and inhibiting neuronal over-excitation. Pre-experiments have demonstrated that exosomes secreted by epileptic neurons express higher level of miR-181a. The glutamate uptake capacity and the expression of Bcl-2 and GLT-1 of astrocytes cultured with these exosomes decreased significantly, furthermore these astrocytes caused a sustained increase in neuronal electrical excitability. Therefore, we hypothesized that after seizure, neurons secrete exosomes to their surroundings. These exosomes carrying the miR-181a signal are received by astrocytes and induce a decrease in glutamate uptake through the Bcl-2 pathway which promote the epileptogenesis process. Thus, this subject intended to use gene regulation, patch clamp and other techniques from in vitro and in vivo environment to further explore the mechanism of exosome-mediated neuronal-astrocyte information transmission in the process of epilepsy, i and provide experimental evidence for finding new targets for prevention and treatment of epilepsy.

传统药物通过抑制神经元兴奋治疗癫痫效果有限，星形胶质细胞摄取突触间隙谷氨酸的能力异常是导致难治性癫痫的重要原因，但导致此进程的原因和机制不清。新近发现外泌体介导的神经元-星形胶质细胞间信号传递是维持胶质细胞谷氨酸摄取、抑制神经元过度兴奋的关键机制，预实验证明癫痫神经元分泌的外泌体高表达miR-181a，与其共培养后的星形胶质细胞谷氨酸摄取能力明显下降，同时Bcl-2、GLT-1表达降低，且此胶质细胞可引起神经元电兴奋性持续性升高。故提出假设：致痫刺激后神经元向其周围分泌外泌体，这些携带miR-181a信号的外泌体被星形胶质细胞接收并通过Bcl-2通路诱导其谷氨酸摄取能力下降进而推进癫痫进程。据此，本课题将从体外和体内环境角度，采用基因调控、膜片钳等技术，深入探讨外泌体介导的神经元-星形胶质细胞信息传递在癫痫进程中的作用机制，为寻找防治癫痫新靶点提供实验依据。

传统药物通过抑制神经元兴奋治疗癫痫效果有限，星形胶质细胞摄取突触间隙谷氨酸的能力异常是导致难治性癫痫的重要原因，但导致此进程的原因和机制不清。外泌体介导的神经元-星形胶质细胞间信号传递是维持胶质细胞谷氨酸摄取、抑制神经元过度兴奋的关键机制。我们实验发现癫痫神经元分泌的外泌体高表达miR-181c-5p，与其共培养后的星形胶质细胞谷氨酸摄取能力明显下降，同时CREB、GLT-1表达降低，且此胶质细胞可引起神经元电兴奋性持续性升高。故我们认为致痫刺激后神经元向其周围分泌外泌体，这些携带miR-181c-5p信号的外泌体被星形胶质细胞接收并通过CREB通路诱导其谷氨酸摄取能力下降进而推进癫痫进程。据此，本课题将从体外和体内环境角度，采用基因调控、膜片钳等技术，深入探讨外泌体介导的神经元-星形胶质细胞信息传递在癫痫进程中的作用机制，为寻找防治癫痫新靶点提供实验依据。