干细胞在心肌组织中增殖及胞吐对磁共振在体示踪信号影响规律及其机制的实验研究

项目名称： 干细胞在心肌组织中增殖及胞吐对磁共振在体示踪信号影响规律及其机制的实验研究

项目编号： No.81201208

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 影像医学与生物医学工程

项目作者： 刘琼

作者单位： 中国医学科学院

项目金额： 22万元

中文摘要： 目前对于骨髓间充质干细胞移植于心肌组织后的增殖和胞吐规律尚不明确。干细胞分裂增殖及胞吐可能是干细胞被顺磁性氧化铁颗粒（SPIO）标记后排除标记物的主要机制，也是造成磁共振在体示踪信号不能客观反映实际存活干细胞数量的主要原因。本项目以大鼠为研究对象，将磁共振成像及生物发光成像相结合, 以病理组织学、分子生物学及细胞学实验为佐证，动态量化分析干细胞移植于心肌后增殖、凋亡、胞吐等生物学行为演变规律。借助细胞内对比剂SPIO明确磁共振在体示踪信号衰减规律与干细胞生物学行为之间的联系。结合细胞学实验、通过膜片钳技术检测膜电容变化探索干细胞在体外及在心肌组织中的胞吐规律，以EdU掺入法、流式细胞仪及增殖细胞核抗原免疫组化检测干细胞在体内外的增殖规律。在此基础上，探索干细胞在心肌组织中的分裂增殖及胞吐对磁共振在体量化移植干细胞的影响规律；并进一步探索缺血缺氧对干细胞增殖及胞吐等生物学行为的影响。

中文关键词： 干细胞；心肌梗死；磁共振成像；；

英文摘要： To develop effective mesencymal stem cells (MSCs)-based therapies for myocardial repair, the location, distribution, and long-term viability of the cells must be determined in a noninvasive manner. Magnetic resonance imaging (MRI) of cells labeled with magnetically visible contrast agents has the potential to fulfill this aim. The most sensitive existing markers for cell labeling using MRI are superparamagnetic iron oxide (SPIO) particles. But the accuracy of quantification of transplanted stem cells by MRI was unreliable because the signal of SPIO will underestimate the quantification of live stem cells in myocardium. It is supposed that the proliferation and exocytosis should be the main mechanism that MSCs exclude SPIO. In the culture medium, the proliferation of MSCs will be assessed by the EdU incorporation assay. The flow cytometry and the exocytosis of MSCs will be explored by the fluorescence of FM4-64 displaying in the cell membrane and by patch clamp detecting membrane capacitance. Furthermore, the animal study will be executed to explore the proliferation, exocytosis and apoptosis in vivo. The animal models of myocardial infarction are prepared with rats. Accordingly the rats suffered from sham operation will be control groups. All the animal models are divided into six experimental groups and the cor

英文关键词： stem cells；myocardial infarction；magnetic resonance imaging；；