rno-miR-184靶向HIF-1α/LDHA介导“痫性发作预适应”的抗癫痫形成机制研究

At present, antiepileptic drugs mainly act on ion channels or receptors to suppress seizures, and they don't have direct antiepileptogenesis effect. Seizure preconditioning can activate endogenous protective pathway for antiepileptogenesis. We found hippocampal rno-miR-184 was greatly elevated after seizure preconditioning，resulting in decrease of neuronal apoptosis and loss, and then antiepileptogenesis. Further research found that rno-miR-184 not only inhibited the expression of LDHA through HIF-1α, but also directly decreased the expression of LDHA. Therefore, we show two possible mechanisms about that rno-miR-184 decreases the expression of LDHA and then involves in the mechanisms of antiepileptogenesis of seizure preconditioning: indirect and direct regulation mechanisms. In our study, we aim to reveal and verify the proposed mechanisms underlying LDHA regulation by rno-miR-184 combined the methods of electrophysiology, molecular biology, tissue morphology and animal behavior. Upregulation of hippocampal rno-miR-184 after seizure preconditioning is supposed to decrease free HIF-1α by absorbing a large amount of HIF-1α, leading to inhibited LDHA expression. rno-miR-184 upregulation also can directly decrease expression of LDHA, which eventually cause enhanced pyruvate and decreased lactic acid. We will also reveal novel biomarker and therapeutic target. This project is an interdisciplinary study based on medicine and engineering. The results will help to provide biological evidences for the prevention and management of temporal lobe epilepsy and for the development of new antiepileptic drugs.

目前抗癫痫药主要是作用于离子通道或受体抑制癫痫发作，并无抗癫痫形成作用。“痫性发作预适应”可激活内源性保护途径起抗癫痫形成。前期发现痫性发作预适应24h后大鼠海马rno-miR-184显著增高，可减少神经元凋亡和丢失，最终抗癫痫形成。通过预实验发现rno-miR-184既可通过HIF-1α抑制LDHA，又可以直接下调LDHA表达。因此我们提出rno-miR-184调控LDHA介导“痫性发作预适应”抗癫痫形成的两种机制：间接和直接调控模式。本课题将从临床和动物二个层面，采用离体/在体电极记录、分子生物学、组织形态及行为学验证：痫性发作预适应rno-miR-184↑→竞争结合HIF-1α能力↑，游离HIF-1α↓或直接与LDHA相互作用→LDHA↓→丙酮酸↑，乳酸↓→抗癫痫形成。并探索早期发病相关分子标记及靶向治疗药物。本研究将医学与工程方法结合，为颞叶癫痫一级预防和新药研发提供理论依据。

颞叶癫痫是成人最常见的局灶性癫痫，其发病过程相对复杂且缓慢，因而也成为药物难治性癫痫中最常见的类型。从出现致痫因素到发展为癫痫之间的这段潜伏期被称为癫痫形成。目前抗癫痫药主要是作用于离子通道或受体抑制癫痫发作，并无抗癫痫形成作用。深入研究癫痫形成的分子机制，寻找其核心调控因子及早期有效预测的分子标记，是目前癫痫研究领域迫切需要解决的关键问题，这对于靶向降低患者耐药、提高远期无发作率具有重要的现实意义。. “痫性发作预适应”可激活内源性保护途径起抗癫痫形成。本课题拟从临床和动物二个层面，采用电极记录、分子生物学、组织形态学及行为学发现其中分子机制。. 本课题发现大鼠海马区域rno-miR-184可以与LDHA相互作用，并直接参与调控LDHA表达。预适应24h后海马区域rno-miR-184显著增高，抑制LDHA表达，同时区域神经元凋亡以及丢失减少。LDHA位于HIF-1信号通路，具有内源性神经保护作用的痫性发作预适应使得大鼠海马中rno-miR-184增高，通过影响HIF-1信号通路，从而抑制下游LDHA基因表达，最终抑制癫痫形成的信号转导通路。本项目研究它们在癫痫形成和发展演变中的表达变化和作用机制，为寻找新的有效一级预防及难治性癫痫诊断、治疗和术后预后奠定研究基础，具有重要的科学意义和应用价值。