ADULT-DERIVED STEM CELL DIFFERENTIATION IN THE HEART

描述（由申请人提供）：心力衰竭是美国过早死亡和残疾的主要原因。 成人来源的干细胞可以为有效的治疗提供基础。 该建议是基于我们的发现，即从成年大鼠肝脏中分离出的一种充分表征的成体干细胞系（WB-F344）在成年心脏中体内分化为心脏细胞。 我们将使用WB-F344干细胞系和Fischer 344（F344）大鼠在正常心脏和左前降支（LAD）冠状动脉结扎模型。 我们将测试：假设1。 WB-F344细胞植入心脏，获得结构心脏表型，并在体内分化为成熟心肌细胞。 在两种模型中，这些过程将受到不同的宿主心脏微环境的影响。 我们将定性和定量地研究这些过程。 B-半乳糖苷酶活性将用于鉴定WB-F344衍生的肌细胞。 将使用转录因子、肌丝蛋白和膜蛋白的表达以及解剖学偶联的重塑及其分布来检查心脏谱系的承诺和心脏表型的获得。 假设2. WB-F344衍生的心肌细胞获得成年心肌细胞的功能表型。 在两种模型中，这些功能特性将受到宿主心脏微环境的影响。 我们将研究分离的单个WB-F344衍生的肌细胞和宿主肌细胞的机械和电生理特性，以及它们与宿主细胞的原位通讯。 假设3. WB-F344衍生的心肌细胞影响体内心室功能。 心肌梗死后心脏的左心室功能障碍将由WB-F344衍生的心肌细胞调节。 将使用超声心动图和心导管检查WB-F344细胞植入和分化对体内左心室功能和大小的影响。 这些研究将为干细胞来源的心肌细胞的功能特性和基于干细胞的方法治疗心力衰竭的潜在价值提供新的重要信息。

DESCRIPTION (provided by applicant): Heart failure is a major cause of premature death and disability in the United States. Adult-derived stem cells could provide a basis for effective therapies. This proposal is based on our finding that a well characterized adult-derived stem cell line (WB-F344), isolated from the adult rat liver, differentiates in vivo in the adult heart into heart cells. We will use the WB-F344 stem cell line and Fischer 344 (F344) rats in the normal heart and left anterior descending (LAD) coronary artery ligation model. We will test:Hypothesis 1. WB-F344 cells engraft in the heart, acquire a structural cardiac phenotype, and differentiate into mature cardiac myocytes in vivo. These processes will be affected by the different host cardiac microenvironments in the two models. We will examine these processes qualitatively and quantitatively. B-galactosidase activity will be used to identify WB-F344-derived myocytes. The commitment to a cardiac lineage and acquisition of a cardiac phenotype will be examined using expression of transcription factors, myofilament proteins, and membrane proteins and the remodeling of anatomical couplings, and their distribution. Hypothesis 2. WB-F344-derived myocytes acquire the functional phenotype of adult cardiac myocytes. These functional properties will be affected by the host cardiac microenvironments in the two models. We will examine the mechanical and electrophysiological properties of isolated single WB-F344-derived myocytes and host myocytes in vitro and their communication with host cells in situ. Hypothesis 3. WB-F344-derived cardiac myocytes affect ventricular function in vivo. Left ventricular dysfunction in the post myocardial infarction heart will be moderated by WB-F344-derived myocytes. The effects of WB-F344 cell engraftment and differentiation on in vivo left ventricular function and size will be examined, using echocardiography and cardiac catheterization. The proposed studies will provide new and important information about the functional properties of stem cell-derived cardiac myocytes and the potential value of stem cell-based approaches to treating heart failure.