E3泛素连接酶NEDD4调控神经元细胞周期重返及凋亡的机制研究

项目名称： E3泛素连接酶NEDD4调控神经元细胞周期重返及凋亡的机制研究

项目编号： No.31201018

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 遗传学与生物信息学、细胞生物学

项目作者： 邓其跃

作者单位： 中国人民解放军第三军医大学

项目金额： 23万元

中文摘要： 凋亡是神经系统外伤和退行性疾病中神经元死亡的主要共同机制，异常的细胞周期重返（cell cycle re-entry）是凋亡的诱发因素之一，但调控机制尚不清楚。PI3K/Akt通路参与细胞周期调控并显著影响细胞的存活，IGF-1R和PTEN分别激活和抑制该通路。神经元E3泛素连接酶NEDD4同时介导IGF-1R和PTEN的泛素化，可能经PI3K/Akt通路调控神经元细胞周期重返和凋亡。为验证该假设1）建立NEDD4表达上调或下调细胞模型，检测可能受NEDD4调控的细胞周期蛋白；2）以培养脊髓神经元为离体模型，在氧糖剥夺等应激条件下检测NEDD4相关分子，把IGF-1R与PTEN的泛素化、亚细胞定位、下游信号与细胞周期调控和凋亡联系起来；3）以小鼠脊髓损伤为模型检测NEDD4相关信号通路，在体验证该假设。通过以上研究探讨NEDD4介导泛素化对神经元细胞周期重返的调控机制，发现神经保护新靶点。

中文关键词： NEDD4-1；PTEN；神经元；细胞周期重返；MIF

英文摘要： Apoptosis represents one major common mechanism of neuronal death both in the nervous system injury and in neurodegenerative diseases. Aberrant cell cycle re-entry (CCE) has been found to be one mechanism leading to apoptosis in neurons. Because of its high specificity in protein degradation, ubiquitination is emerging as an important novel mechanism in cell cycle regulation. We found that the E3 ligase NEDD4 mediates the ubiquitination of both IGF-1R and PTEN, resulting in suppression and activation of PI3K/Akt signaling, respectively. Due to the important roles of PI3K/Akt signaling pathway in neuronal cell survival, we hypothesize that NEDD4 plays a role in neuronal cell cycle regulation. To test this hypothesis, we will use primary neurons to investigate multiple cell cycle associated molecules that may be regulated by NEDD4 (e.g., over-expressing NEDD4 using wt-NEDD4 or silencing NEDD4 with siRNA). Furthermore, we will investigate these changes under various neuronal stressed conditions such as oxygen-glucose deprivation, oxidation mediated by H2O2 and nitric oxide (NO) and Zn2+ homeostasis disturbance induced by ZnSO4; in particular, the downstream signaling and the sub-cellular localization of IGF-1R and PTEN will be studied in the context of neuronal cell cycle control and apoptosis. Lastly, we will val

英文关键词： NEDD4-1；PTEN；neuron；cell cycle re-entry；MIF