Signaling Pathways in Cardiovascular Differentiation

描述（由申请人提供）：心力衰竭是所有患者死亡的主要原因。这在很大程度上反映了心脏有限的自我修复能力，使得基于细胞的再生心脏干预策略非常有吸引力。尽管为此目的研究了许多类型的细胞，但人类胚胎干细胞（ES）或诱导多能干细胞（iPS）提供了特别有前途和可靠的心脏细胞来源。该项目的总体目标是阐明人类胚胎干细胞和iPS细胞在心血管细胞发育过程中的信号通路，从而为心血管疾病的有效介入治疗提供依据。为了实现我们的研究目标，提出了两个具体的目标。在Aim 1中，我们将确定Wnt信号在人类胚胎干细胞和iPS细胞向心肌细胞分化中的作用，使用一组细胞类型特异性标记来估计心脏分化的效率。在目标2中，我们将研究来自人类胚胎干细胞和iPS细胞的多能心血管祖细胞。这些祖细胞将通过其血管内皮生长因子受体2 （VEGFR2）的表达来鉴定。我们将测试激活素A、BMP4和Wnt信号通路增强这些祖细胞生成的能力。此外，我们将探索这些细胞在响应Wnt、VEGF和PDGF信号分子时分化为心肌细胞、平滑肌细胞和内皮细胞的能力。从公共卫生的角度来看，心脏病是美国人死亡的头号原因，也是最使人衰弱的慢性疾病之一，尽管治疗策略不断取得进展。我们提出了一种现代方法来研究关键信号分子在控制胚胎和诱导多能干细胞向功能心血管细胞分化中的作用。这将提高我们产生以细胞为基础的心脏病再生疗法的能力。

DESCRIPTION (provided by applicant): Heart failure is a leading cause of death among all patient populations. This largely reflects the heart's limited ability for self-repair, making cell-based strategies for regenerative cardiac intervention highly attractive. Although many cell types have been examined for this purpose, human embryonic stem (ES) cells or induced pluripotent stem (iPS)cells provide particularly promising and reliable sources of cardiac cells. The overall goal of this project is to elucidate signaling pathways in the development of cardiovascular cells from human ES and iPS cells, from which effective interventional therapies for cardiovascular disease can be derived. Two specific aims are proposed to accomplish our research goals. In Aim 1, we will determine the role of Wnt signaling in the differentiation of human ES and iPS cells into cardiomyocytes, using a panel of cell-type specific markers to estimate the efficiency of cardiac differentiation. In Aim 2, we will study multipotent cardiovascular progenitor cells derived from human ES and iPS cells. These progenitors will be identified by their expression of vascular endothelial growth factor receptor 2 (VEGFR2). We will test the ability of Activin A, BMP4, and Wnt signaling pathways to enhance generation of these progenitors. In addition, we will explore the ability of these cells to differentiate into cardiomyocytes, smooth muscle cells, and endothelial cells in response to Wnt, VEGF and PDGF signaling molecules. From a public health perspective, heart disease is the number one cause of death in the United States and among the most debilitating chronic diseases, despite continuing advances in treatment strategies. We propose a modern approach to examine the role of key signaling molecules in controlling the differentiation of embryonic and induced pluripotent stem cells into functional cardiovascular cells. This will improve our ability to generate cell-based regenerative therapies for heart disease.