Stem Cell Differentiation for Myocardial Therapy

描述（由申请人提供）：受损心肌的细胞替代疗法一直是心力衰竭治疗中重要但难以实现的目标。我们实验室的总体目标是了解肌细胞增殖和分化的调节，以及这些过程如何介导心肌发育和疾病。我们目前的方法是鉴定和表征来自人胚胎干细胞（hESC）的心肌细胞，并使用这些细胞来模拟心肌发育和探索心肌疾病的细胞疗法。我们的目标是确定hESC的亚群，发展成不同的心肌细胞类型，确定hESC衍生的心肌细胞最有效地植入宿主组织的发育阶段，并证明hESC衍生的细胞可用于改善心肌损伤后的心脏功能。这些直接关系到PA-05-043的长期目标（定向干细胞分化用于心脏，肺，血液和衰老疾病的细胞治疗）。本发明的具体目的是：1）鉴定优先分化为心肌细胞的增殖hESC的特定亚群;我们将通过体外将特定hESC亚群分化为心肌细胞，并表征发育和室特异性基因表达和动作电位传播来实现这一点; 2）确定hESC衍生的心肌细胞在体内最有效地移植的发育阶段和组织环境在心肌细胞亚特化中的作用;我们将通过开发报告人胚胎干细胞系和“分子信标”策略来实现这一点，以在特定的发育时间点分离心肌细胞，并确定它们在体内小鼠心肌中的植入和分化;和3）证明在心肌梗塞小鼠模型中用hESC衍生的心肌细胞进行细胞治疗的效果;我们将通过评价移植hESC衍生的心肌细胞后心肌梗塞小鼠模型中的心脏功能和电传导来实现这一点。这些研究将为人类心肌发生提供新的见解，并为心肌再生提供新的方法。

DESCRIPTION (provided by applicant): Cell replacement therapy for damaged myocardium has been an important yet elusive goal in the treatment of heart failure. Our laboratory's overall goal is to understand the regulation of muscle cell proliferation and differentiation, and how such processes mediate myocardial development and disease. Our current approaches are to identify and characterize myocardial cells derived from human embryonic stem cells (hESCs), and to use these to both model myocardial development and explore cell therapies for myocardial diseases. Our goals for this proposal are to determine subpopulations of hESCs that develop into different cardiomyocyte types, identify the developmental stage at which hESC-derived myocardial cells most effectively engraft into host tissue, and demonstrate that hESC-derived cells can be used to improve cardiac function following myocardial injury. These relate directly to the long-range goal of PA-05-043 (Directed Stem Cell Differentiation for Cell-Based Therapies for Heart, Lung, And Blood, and Aging Diseases). The specific aims of this proposal are to: 1) identify specific subpopulations of proliferating hESCs that preferentially differentiate into cardiomyocytes; we will accomplish this by differentiating specific hESC subpopulations into cardiomyocytes in vitro, and characterizing developmental- and chamber-specific gene expression and action potential propagation; 2) determine the developmental stage at which hESC-derived myocardial cells most effectively engraft in vivo and the role of the tissue environment in cardiomyocyte subspecialization; we will accomplish this by developing reporter hESC lines and "molecular beacon" strategies for isolating myocardial cells at specific developmental time points, and determining their engraftment and differentiation in mouse myocardium in vivo; and 3) demonstrate the effects of cell therapy with hESC-derived myocardial cells in a mouse model of myocardial infarction; we will accomplish this by evaluating cardiac function and electrical conduction in a mouse model of myocardial infarction following transplant with hESC-derived myocardial cells. The proposed studies will provide new insight into human cardiac myogenesis, and offer novel approaches to myocardial regeneration.