Thorase在脑卒中发生过程中对神经元保护作用的研究

There are no efficacious therapeutic medicines or approaches available for treating stroke patients. In a functional screening strategy aimed at identifying neuroprotective genes, we identified a novel AAA+ ATPase, Thorase, with neuroprotective properties. In vitro assay showed that overexpression of Thorase could prevent primary cultured cortical neurons from NMDA or OGD (oxygen-glucose deprivation)-induced damage. About 80% of Thorase Knockout mice die from a stroke-like syndrome on postnatal day 19 to 25. In this application we will study the roles of Thorase in regulating neuronal survival and death using both "loss of function" strategy - Thorase KO mice and "gain of function" strategy - Thorase transgenic mice. We propose that Thorase provides neuroprotective function by regulating glutamate receptor mediated excitotoxicity. This study will confirm if Thorase has neuroprotective function during stroke and may have implications for our understanding of the molecular mechanisms that underlie cell death during stroke. Furthermore, by controlling its ATPase activity Thorase might potentially be a "druggable" target for pharmacological interventions in stroke and other neurodegenerative diseases.

目前世界上缺乏有效的治疗和预防脑卒中的药物和手段。我们通过一个功能性筛选发现了一种新的AAA+ ATP水解酶-Thorase对神经元具有保护作用。体外过表达Thorase能够使神经元免受NMDA或氧糖剥离（OGD）诱导的损伤。大约80%的Thorase基因敲除小鼠在出生19-25天之间死于类似中风症状的疾病。在本课题中我们将运用"功能丧失"-基因敲除小鼠和"功能增益"-转基因小鼠两种策略来研究Thorase在脑卒中发生过程中对神经元存活与死亡的调控。我们认为Thorase可能通过调节谷氨酸受体介导的神经元兴奋性来调控神经元的存活与死亡。本研究将证明Thorase是否在脑族中发生过程中对神经元具有保护作用，帮助人们进一步了解脑卒中病人脑组织内神经元死亡的机制。同时，通过调控其ATP水解酶活性，Thorase有望作为药物靶标开发具有对脑卒中或其他神经变性性疾病具有治疗和／或预防作用的药物。

在体外或体内对神经元一个非致死性预处理（Preconditioning）可以诱导对神经元有保护作用的蛋白表达，但是分子机制尚不清楚。在本研究中我们发现AAA + ATP水解酶Thorase表达在体外或体内预处理的神经元高表达，并发挥ATP水解酶活性依赖性的神经保护作用，高表达Thorase可以对抗氧糖剥夺（OGD）神经毒性或谷氨酸N-甲基-D-天冬氨酸（NMDA）受体介导的兴奋性毒性作用。基因敲除Thorase （KO）神经元对OGD或NMDA诱导的神经毒性损伤更加敏感，并破坏预处理（Preconditioning）诱导的对OGD和NMDA神经毒性反应的神经保护作用。Thorase 转基因小鼠对脑缺血引起的脑损伤有保护作用，条件性Thorase KO小鼠对于脑缺血更加敏感。该研究结果证实Thorase对神经元具有保护作用，可以为脑卒中等神经疾病的治疗提供新策略。