Comprehensive in vivo MRI of mouse embryonic stem cell myocardial engraftment

描述(由申请人提供)： 摘要：提交本提案是为了请求继续在干细胞研究K18职业提升奖(02/01/07-01/31/09)期间进行的研究。在这项拟议的研究中，进一步的研究是为了增强体内细胞和分子磁共振对心肌移植后mESC的存活和增殖(畸胎瘤形成)的研究。这项研究的基本原理来自再生医学的一个基本概念：移植的细胞必须存活下来，才能触发一系列复杂的生物过程，以再生和永久恢复受损的心肌。虽然MRI已经成为追踪体外标记细胞和评估受体心肌功能恢复的主要手段之一，但关于细胞存活和增殖的确切信息在体内还无法评估。这项研究建议开发强大的体内MRI方法来检测和定量移植到受损心肌中的存活细胞，这将使再生医学的治疗效果得到准确评估，同时还可以监测潜在的畸胎瘤形成。新的MRI方法、创新的细胞和分子技术以及一系列成熟的方法被整合在一起，以研究三个假设驱动的特定目标：特定目标1锰(Mn2+)引导的活体细胞MRI将能够对mESC移植到受损小鼠心肌中后的存活进行纵向评估。特定目的2报告基因(RG)引导的基因工程细胞体内分子磁共振成像将使纵向评估mESC移植到受损小鼠心肌后的存活。具体目的3适量存活的mESC可修复受损心肌，减少畸胎瘤的形成。这项研究计划概述了对体内细胞和分子磁共振的严格研究，以解决再生医学中的一个基本挑战：mESC在进入受损心肌后的存活和异常增殖。这项建议旨在推进体内细胞和分子磁共振方法，并进行概念验证。MRI的高空间和时间分辨率将通过特定活性的细胞和分子信号放大技术来优化，以生成移植到靶器官后细胞存活和畸胎瘤形成的定量数据。在这项研究成功完成后，将开发一个全面的MRI平台来量化细胞的存活、增殖和心肌恢复。这项新兴技术的跨学科应用将为评估任何移植细胞的基本干细胞生物学和评估任何人体器官的受者组织功能提供技术支持。 公共卫生相关声明(由申请者提供)：干细胞研究正处于关键时刻。人类皮肤细胞核重编程以产生多能干细胞，以及人类胚胎干细胞定向分化为心肌细胞的最新进展，可能会在治疗充血性心力衰竭这一公共卫生流行病方面带来重大临床突破。建议的体内磁共振成像系统代表了一个专门的平台，使基础干细胞科学能够系统地转化为临床应用。

DESCRIPTION (provided by applicant): ABSTRACT: This proposal is submitted to request a continuation of the research conducted during the K18 Career Enhancement Award in Stem Cell Research (02/01/07-01/31/09). In this proposed research, further investigation to enhance in vivo cellular and molecular MRI of mESC survival and proliferation (teratoma formation) following transplantation into the myocardium is described. The rationale of this research comes from a fundamental notion underlying regenerative medicine: the transplanted cells must survive to trigger a complex cascade of biological processes to regenerate and restore the injured myocardium permanently. Although MRI has become one of the predominant modalities to track ex vivo labeled cells and to evaluate functional restoration of the recipient myocardium, definitive information on cellular viability and proliferation can not be assessed in vivo. This research study proposes to develop robust in vivo MRI methods to detect and quantitate viable cells following delivery into the injured myocardium, which will enable accurate assessment of therapeutic efficacy of regenerative medicine while also monitor for potential teratoma formation. Novel MRI methods, innovative cellular and molecular techniques, and an array of established methodologies have been integrated to study 3 hypothesis driven Specific Aims: Specific Aim 1 Manganese (Mn2+)-guided in vivo cellular MRI will enable longitudinal evaluation of mESC survival following transplantation into the injured murine myocardium. Specific Aim 2 Reporter gene (RG)-guided in vivo molecular MRI of genetically engineered cells will enable longitudinal evaluation of mESC survival following transplantation into the injured murine myocardium. Specific Aim 3 Optimal quantity of viable mESC will restore the injured myocardium and minimize teratoma formation. This research proposal outlines a rigorous study of in vivo cellular and molecular MRI to address a fundamental challenge in regenerative medicine: mESC survival and abnormal proliferation following delivery into the injured myocardium. This proposal has been designed to advance in vivo cellular and molecular MRI methods with demonstrated proof-of-concept. High spatial and temporal resolution of MRI will be optimized with viability-specific cellular and molecular signal amplification techniques to generate quantitative data on cell survival and teratoma formation following transplantation into target organ. Upon successful conclusion of this research, a comprehensive MRI platform will be developed to quantitate cellular viability, proliferation, and myocardial restoration. Cross-disciplinary application of this nascent technology will provide enabling technology to assess fundamental stem cell biology of any transplanted cell and evaluate recipient tissue function of any human organ. Public Health Relevance Statement (provided by applicant): Stem cell research stands at a critical juncture. Recent development in nuclear reprogramming of human skin cells to generate pluripotent stem cells and directed differentiation of human embryonic stem cells into cardiomyocyte may lead to significant clinical breakthrough in the treatment of congestive heart failure, a public health epidemic. The proposed in vivo MRI system represents a dedicated platform to enable systematic translation of basic stem cell science to clinical application.