线粒体硫加双氧酶ETHE1介导细胞自噬过度活化在贫铀肾毒性中的作用及其机制研究

项目名称： 线粒体硫加双氧酶ETHE1介导细胞自噬过度活化在贫铀肾毒性中的作用及其机制研究

项目编号： No.81472913

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 郝玉徽

作者单位： 中国人民解放军第三军医大学

项目金额： 70万元

中文摘要： 贫铀被广泛应用于民事和军事活动中，肾脏是其中毒的靶器官，但中毒机制有待于研究。我们前期研究发现人胚肾细胞HEK293暴露于贫铀后24h，胞内自噬体增多，自噬体膜标志蛋白LC3-Ⅱ增高，而使用自噬抑制剂后，贫铀的细胞毒性降低，提示自噬过度活化可能在贫铀肾毒性中发挥了重要作用。同时还发现，随贫铀诱导细胞自噬水平的增高，细胞内线粒体硫加双氧酶ETHE1逐渐降低。结合最新研究进展，ETHE1是p53的抑制蛋白，而p53/AMPK又是自噬调节的关键通路，推测贫铀可能通过下调ETHE1，激活p53/AMPK信号通路，抑制mTOR途径，促进细胞自噬过度活化而导致其肾毒性。为证实这一假说，拟利用本室已建立的体内外贫铀中毒模型，采用分子生物学、基因转染、siRNA干扰、流式细胞术等技术，评价贫铀对肾细胞自噬的影响及其在肾毒性中的作用，探讨ETHE1、p53及AMPK对其调控机制，为防治贫铀中毒提供新靶点。

中文关键词： 贫铀；肾毒性；自噬；凋亡

英文摘要： Depleted uranium (DU) is widely used in the civil and military activities, and kidney is the main target organ of toxicity of DU. However, the mechanism of DU-induced nephrotoxicity needs to clarify. Our previous research has confirmed that after 24h exposure to DU, the autophagic vacuoles in the human embryonic kidney cells (HEK293) increase, the autophagy marker LC3-Ⅱ increases, and cytotoxicity decreases after using autophagy inhibitor, suggesting that autophagy may play an important role in DU-induced nephrotoxicity. Meanwhile, mitochondrial sulfur dioxygenase ETHE1 decreases as the exposure dose of DU increases, with increasiong autoghagy flux. ETHE1 is a p53 inhibitor, and p53/AMPK axis is an important signal pathway of autophagy. On the basis of the latest research, we speculate that through reducing ETHE1, activation of p53/AMPK pathway and inhibiting mTOR pathways, DU might induce autophagy overactive which affects the nephrotoxicity. To confirm this hypothesis, in vitro and vivo model of DU-induced nephrotoxicity will be set by using HEK293 cells and mice. Molecular biology, siRNA technology and flow cytometry will be used to determine the effect of DU on autophagy and the role of autophage on the nephrotoxicity, and explore the mechanisms of DU-induced autophagy by EHTE1, p53 and AMPK. This study will provide a novel therapeutic target for the prevention and treatment of DU-induced nephrotoxicity.

英文关键词： depleted uranium;nephrotoxicity;autophagy;apoptosis