运用基因编码的钙荧光探针研究心肌线粒体微区钙信号

项目名称： 运用基因编码的钙荧光探针研究心肌线粒体微区钙信号

项目编号： No.30800371

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 医药、卫生

项目作者： 陈敏

作者单位： 北京大学

项目金额： 22万元

中文摘要： 钙离子是真核细胞内广泛分布的信使物质，对细胞功能具有重要的调节作用。线粒体在细胞能量代谢中起着核心作用，与细胞的生理和病理活动有着直接的关系。线粒体钙不仅直接参与线粒体的功能调节，也是细胞钙信号的重要组成部分，对于我们完整地理解钙信号的调控机制以及线粒体的功能调节都是必不可少的。本课题以新一代的基因编码的荧光探针为基础，深入研究了肌细胞线粒体的钙信号，以及密切相关的活性氧信号，结果表明不同类型的细胞因功能需要，其线粒体钙具有不同的动力学特征，其特异的调节机制将会是有效的干预治疗靶点。而线粒体活性氧的量子化释放是一种普遍的生理现象，其活性和能量代谢密切相关，在代谢性疾病的研究中具有一定的意义。同时心肌细胞的能量代谢和钙信号调节是相互偶联在一起的，转录共激活因子PGC-1α22312;其中起了关键的作用，对其有效的干预是改善心功能的一个新途径。此外我们还揭示了一种新的微区钙信号（钙闪烁）在细胞迁移转向中的作用。因此，本研究通过建立新的方法，克服以往研究中的干扰因素，来揭示线粒体与相关信号分子在细胞能量代谢和生理功能间的联系，寻找心血管和代谢疾病中潜在的干预治疗靶点。

中文关键词： 钙信号；线粒体；心肌细胞；荧光探针

英文摘要： As a message molecular widely distributed within the eukaryotic cells, calcium ion plays an important role in the regulation of cell function. Mitochondria are pivotal for cellular energy metabolism and are associated with cellular physiological and pathophysiological activities. Mitochondrial calcium signaling not only is directly involved in the regulation of mitochondrial function, but also is an important part of cellular calcium signaling, which is essential for us to completely understand the regulatory mechanism of calcium signaling and mitochondrial function. In this project, based on the new generation of genetically encoded fluorescent probes, we deeply studied mitochondrial calcium signaling in myocytes, and the closely relative signal molecular, reactive oxygen species (ROS). The results showed that the different types of cells had different dynamic characteristics of mitochondrial calcium signaling because of different cell function. The specific regulatory mechanisms will be the effective targets for therapy and intervention. For the first time, in vivo, we confirmed that the quantized release of mitochondrial ROS is a common physiological phenomenon, and its activity is closely related to energy metabolism, which are significant for the study of metabolic diseases. We also found that the cardiomyocyte's energy metabolism coupled with cytosol calcium signaling that is involved in E-C coupling, which was mediated by a transcriptional co-activator, PGC-1a. The effective intervention to this pathway could be a new way to improve cardiac function. In addition, we also revealed that a new microdomain calcium signaling (calcium flicker) played a role in steering cell migration. Thus, by establishing the new methods, we could overcome the interferential factor in previous studies to reveal the role of mitochondria and related signaling molecules in cellular energy metabolism and physiological functions, which is benefit to search potential targets for therapy of cardiovascular and metabolic disease.

英文关键词： calcium signaling; mitochondria; cardiomyocyte; fluorescent indicator