Molecular Imaging of Stem Cell Transplantation in the Heart

心脏干细胞移植的分子成像

基本信息

批准号：
7613398
负责人：
Juri George Gelovani
金额：
$ 38.5万
依托单位：
UNIVERSITY OF TX MD ANDERSON CAN CTR
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-15 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7613398
关键词：
Adult Anatomy Animals Biological Assay CD34 gene Cardiac Cardiac Myocytes Cell Separation Cells Dose Engraftment Ensure Fluorescence Frequencies Gene Expression Generations Genes Gold Green Fluorescent Proteins Heart Herpesviridae Home environment Human Image Imagery Imaging Techniques Immune Immunohistochemistry In Situ In Vitro Infarction Label Lentivirus Vector Location Magnetic Resonance Magnetic Resonance Imaging Methods Microarray Analysis Microscopic Modality Modeling Morphologic artifacts Motion Mus Muscle Cells Myocardial Myocardial Infarction Myocardial tissue Myocardium Myosin Heavy Chains Natural regeneration Pattern Positron-Emission Tomography Process Proteins Radiation Tolerance Regression Analysis Reperfusion Injury Reporter Reporter Genes Research Personnel Signal Transduction Site Smooth Muscle Myocytes Source Stem cell transplant Stem cells Surface System Techniques Thymidine Kinase Time Tissues Transplantation Troponin T Undifferentiated Vascular Endothelial Cell base cell motility cell transformation cellular transduction human stem cells in vivo injured insight iron oxide molecular imaging nanoparticle novel peripheral blood progenitor programs promoter radiotracer red fluorescent protein sensor trafficking

项目摘要

DESCRIPTION (provided by applicant): Our objective is to develop and validate cellular and molecular imaging techniques that can be used to track recruitment and differentiation of progenitor cells into cardiomyocytes in vivo. In preliminary studies, we showed that adult peripheral blood CD34+ cells injected intraventricularly into severe combined immune- deficient (SCID) mice could transform into myocytes and smooth muscle cells in the heart. However, it is difficult to follow the recruitment of progenitor cells into the heart and their subsequent differentiation/fusion into various cardiac cells in vivo. In this proposal, we wish to develop cellular and molecular imaging techniques that will allow us to reliably track recruitment of progenitor cells into the injured heart and to follow the time course of their differentiation or fusion into cardiomyocytes. Human stem cells derived from different sources will be assayed in a SCID mouse myocardial regeneration model for selection of the best source of stem cells; the selected cells then will be genetically modified using retroviral or lentiviral vectors bearing a dual positron emission tomography (PET) reporter gene construct. This construct will encode for a constitutively expressed "beacon" reporter gene-the truncated human thymidine kinase type two fused with red fluorescent protein (hTK2RFP)-and a "sensor" reporter gene, consisting of the herpes virus type one thymidine kinase fused with green fluorescent protein (sr39TKGFP) controlled by the a-myosin heavy chain promoter. In vivo PET imaging of the hTK2RFP "beacon" reporter will be accomplished with hTK2-specific radiotracer [18FJFEAU. PET imaging of the sr39TKGFP "sensor" will be performed with sr39HSV1-TK specific radiotracer [18F]FHBG. Importantly, PET imaging with [18F]FHBG does not detect the hTK2RFP "beacon" reporter expression. Repetitive whole body in vivo imaging of "beacon" gene expression will provide quantitative information about the dynamics and patterns of "reporter cell" migration, engraftment, and viability of progeny cells. Most importantly, PET images of "sensor" gene expression will reflect the status of cardiomyocyte-specific differentiation of transplanted progenitors and the distribution of progeny cells. The PET images will be co-registered with the magnetic resonance (MR) images, which will be obtained in the same animals for better anatomic localization of PET-detected stem cells and their progeny tissues. This approach will provide insights into the fate of human stem cell transplantation into the heart.

描述（由申请人提供）：我们的目标是开发和验证细胞和分子成像技术，这些技术可用于跟踪祖细胞在体内募集和分化为心肌细胞中的募集和分化。在初步研究中，我们表明成年外周血CD34+细胞注射室内注射为严重的免疫缺陷（SCID）小鼠可以转变为心脏中心肌细胞和平滑肌细胞。但是，很难跟随祖细胞募集到心脏，然后在体内分化/融合到各种心脏细胞中。在此提案中，我们希望开发细胞和分子成像技术，使我们能够可靠地跟踪祖细胞募集到受伤的心脏中，并遵循其分化或融合到心肌细胞中的时间过程。将在SCID小鼠心肌再生模型中测定来自不同来源的人类干细胞，以选择最佳的干细胞来源。然后，将使用带有双正电子发射断层扫描（PET）报告基因构建体的逆转录病毒或慢病毒载体对所选细胞进行基因修饰。该构造将编码为组成型表达的“信标”报告基因基因 - 截短的人胸苷激酶，二型与红色荧光蛋白（HTK2RFP）融合的二型 - 传感器”记者基因，由一型胸腺胺激酶与绿色的荧光素蛋白融合（SR399）（SR399）（SR399）（SR399）（SR399）发起人。 HTK2RFP“ Beacon”记者的体内PET成像将使用HTK2特异性的放射性示踪器[18FJFEAU。 SR39TKGFP“传感器”的PET成像将使用SR39HSV1-TK特异性放射性示例[18F] FHBG进行。重要的是，使用[18F] FHBG的PET成像未检测到HTK2RFP“ Beacon”记者的表达。 “信标”基因表达的体内成像的重复整体将提供有关“报道细胞”迁移，植入和后代细胞生存能力的动力学和模式的定量信息。最重要的是，“传感器”基因表达的PET图像将反映出移植祖细胞和后代细胞分布的心肌细胞特异性分化的状态。 PET图像将与磁共振（MR）图像共同注册，该图像将在同一动物中获得，以更好地对宠物探测的干细胞及其后代组织的解剖学定位。这种方法将为人类干细胞移植到心脏的命运提供见解。