Notch 信号调控小管上皮细胞去分化在肾脏缺血耐受中的作用

项目名称： Notch 信号调控小管上皮细胞去分化在肾脏缺血耐受中的作用

项目编号： No.81200493

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 医学二处

项目作者： 蒋素华

作者单位： 复旦大学

项目金额： 23万元

中文摘要： 去分化是有机体长期进化过程中获得的一种保护性和适应性现象，细胞去分化后具有更强的存活力和增殖修复潜能，而Notch是调控细胞分化方向的重要信号通路。我们前期研究发现：预缺血（20 min）能诱导肾脏耐受4天后的第二次长时间缺血（40 min）,但机制尚不清楚。预实验显示：预处理营造的适度低氧微环境能激活Notch信号和促进肾小管上皮细胞去分化。推测：Notch信号调控的小管上皮细胞去分化可能是延迟性缺血预适应诱导肾脏缺血耐受的重要机制。研究采用免疫印迹、激光共聚焦、脂质体细胞转染等技术，结合体内和体外实验，1）观察预缺血后肾小管上皮细胞表型和生物学特性的动态变化，分析其与Notch信号活化和肾脏缺血耐受的关系；2）研究Notch信号抑制或过表达对细胞分化状态、能量代谢、增殖及肾脏结构和功能的影响。期望通过本项目研究，揭示肾脏延迟性缺血预适应的关键保护机制，为缺血性肾损伤的防治提供实验依据。

中文关键词： 肾脏；急性肾损伤；缺血预适应；细胞去分化；Notch 信号

英文摘要： Dedifferentiation is a protective and adaptive phenomenon. In order to survive from the injury, dedifferentiated cell has enhanced viability and proliferation potential. Notch signaling is important for maintaining the undifferentiated cell state. Our previous study showed that 20-min ischemia pretreatment protected the kidney from 40-min ischemia/reperfusion injury occurring four days later. However, the protective mechanism is unclear. We found hypoxia microenvironment, following ischemia pretreatment, can activate Notch signaling and promote the dedifferentiation of epithelial cells in proximal tubules. Thus, we speculate that tubular cell dedifferentiation is mediated by Notch survival signaling,and cell dedifferentiation in turn enhances ischemia tolerance in the kidney. In this study, Western blot, immunohistochemistry, confocal laser, and cell transfection technology will be used. In vivo and in vitro experiments, following ischemia or hypoxia pretreatment, we will observe the dynamic change in renal tubular epithelial cell phenotype, and further demonstrate its relationship with Notch signaling activation and renal ischemia tolerance. In the next step, through overexpressing of Notch intracellular domain and inhibiting Notch with γ-secretase inhibitor, the impact of Notch activation on cell dedifferent

英文关键词： Kidney；acute kidney injury；ischemic precontioning；cell dedifferentiation；Notch signaling