Chemical Induction of Cardiomyogenesis

心肌发生的化学诱导

• 批准号: 7930352
• 负责人: CHARLES C HONG
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7930352
• 关键词: American; Animals; Autologous; Blood Vessels; Brachyury protein; Cardiac; Cardiac Myocytes; Cardiovascular system; Cell Lineage; Cell Therapy; Cells; Cessation of life; Chemicals; Clinical; Commit; Development; Embryonic Stem Cell Transplantation; Face; Future; Heart; Heart Diseases; Heart failure; Hematopoietic; Hour; Human; In Vitro; Injury; Lead; Life; Mesoderm; Mesoderm Cell; Methods; Molecular Profiling; Mus; Myocardial; Myocardial Infarction; Nature; Organ Transplantation; Patients; Pharmaceutical Preparations; Pharmacologic Substance; Phosphotransferases; Play; Pluripotent Stem Cells; Process; Regenerative Medicine; Role; Route; Signal Transduction; Skin; Smooth Muscle Myocytes; Somatic Cell; Staging; Stem cells; Teratoma; Testing; Therapeutic; Therapeutic Effect; Therapeutic Uses; Tissues; Translations; Transplantation; Tube; Vascular Endothelial Growth Factor Receptor; Veterans; adult stem cell; analog; base; cell type; cellular engineering; disability; embryonic stem cell; heart cell; improved; in vivo; in vivo regeneration; induced pluripotent stem cell; inhibitor/antagonist; mature animal; method development; mortality; mouse model; novel; postnatal; progenitor; programs; receptor; regenerative; repaired; small molecule; stem cell differentiation; stem cell therapy; tissue regeneration; tumor

DESCRIPTION (provided by applicant): Heart failure from irreversible cardiac tissue damage is a leading cause of disability and mortality in US. Because the heart has negligible intrinsic capacity to regenerate new tissues to replace those lost to injury, there is currently no definitive heart failure treatment, other than organ transplantation. Recent studies have introduced the prospect of replacing damaged heart tissues with healthy cardiomyocytes derived from exogenous pluripotent stem cells or endogenous cardiovascular progenitors. Particularly promising for therapeutic use are embryonic stem (ES) cells and autologous induced pluripotent stem (iPS) cells, which have been definitively shown to be capable of differentiating into cardiomyocytes. However, realizing the full therapeutic potential of stem cells faces numerous hurdles, including the potential for tumor formation, a low rate of cardiomyocyte formation, and an inadequate understanding of how and which progenitors become cardiomyocytes. Current efforts are also hampered by a lack of pharmaceutical agents to boost therapeutic effects of stem cells. Dorsomorphin, the first known small molecule BMP inhibitor, and its structural analogs are among the most potent chemical inducers of in vitro cardiomyogenesis in mouse embryonic stem cells. However, how the BMP inhibitors induce cardiac formation in ES cells is unclear. Curiously, the cardiomyocyte induction occurs in the absence of a significant increase in mesoderm marker expression. As dorsomorphin also has significant activity against the Flk-1 receptor kinase, a key mesoderm maker, the apparent paradox could be due to this off-target effect. To test this and to identify compounds having the highest capacity for cardiac induction, the effects of dorsomorphin on mesoderm and cardiomyocyte formation will be compared to those of a pure BMP inhibitor DMH1, which has no off-target activity against Flk1+ (Aim 1). Treatment with the BMP inhibitors during the first 24 hours of ES cell differentiation is sufficient for robust cardiac induction, and the cardiac induction coincides with a significant reduction in all of the noncardiac mesoderm lineages. Such an inverse relationship suggests that BMP inhibition during the initial stages of ES cell differentiation commits an early common progenitor toward the cardiac-specific developmental program. To test this, the impact of DMH1 on the developmental potential of mesoderm progenitor cells will be examined (Aim 2). Molecular profiling of the DMH1 treated mesoderm cells will also be performed to characterize the early cardiac progenitor cells induced by DMH1. The Aim 3 will take the next logical step to test whether small molecule-based methods found to robustly induce cardiomyocyte formation in vitro can have a beneficial impact on stem cell therapies to improve cardiac remodeling and function in a mouse model of myocardial injury. In conclusion, the proposed study will utilize a class of potent chemical inducers of cardiomyogenesis to elucidate the mechanism of cardiac specification and differentiation, and thereby inform future stem cell-based strategies to treat heart disease. PUBLIC HEALTH RELEVANCE: Heart failure from irreversible heart damage afflicts over 5 million Americans and is one of the leading causes of disability and death in American veterans. Apart from transplantation, there is currently no definitive treatment for heart failure. Stem cells, which can differentiate into heart tissues, offer real hope for repairing damaged hearts. Such hope has grown more intense in past couple of years with the development of methods to make stem cells from patient's own skin. However, stem cell therapy faces many obstacles, particularly the fact that it is difficult to turn stem cells into heart cells. We recently discovered a class of novel drugs that dramatically promote heart cell formation in stem cells. This project aims to study how these drugs promote heart cell formation in test tubes and to examine whether they can boost the beneficial effects of stem cells in mice suffering heart attacks.

描述（由申请人提供）： 在美国，由不可逆心脏组织损伤引起的心力衰竭是导致残疾和死亡的主要原因。由于心脏再生新组织以取代因损伤而失去的组织的内在能力可以忽略不计，因此除了器官移植外，目前还没有明确的心力衰竭治疗方法。近年来的研究表明，由外源性多能干细胞或内源性心血管祖细胞衍生的健康心肌细胞具有替代受损心脏组织的前景。特别有希望用于治疗用途的是胚胎干（ES）细胞和自体诱导多能干（iPS）细胞，其已明确显示能够分化成心肌细胞。然而，实现干细胞的全部治疗潜力面临着许多障碍，包括肿瘤形成的潜力，心肌细胞形成的低速率，以及对祖细胞如何以及哪些祖细胞成为心肌细胞的理解不足。目前的努力也受到缺乏药剂来提高干细胞治疗效果的阻碍。Dorsomorphin是第一个已知的小分子BMP抑制剂，其结构类似物是小鼠胚胎干细胞体外心肌发生的最有效的化学诱导剂之一。然而，BMP抑制剂如何在ES细胞中诱导心脏形成尚不清楚。奇怪的是，心肌细胞诱导在中胚层标记物表达没有显著增加的情况下发生。由于dorsomorphin对Flk-1受体激酶（一种关键的中胚层标记物）也具有显著的活性，因此明显的矛盾可能是由于这种脱靶效应。为了测试这一点并鉴定具有最高心脏诱导能力的化合物，将dorsomorphin对中胚层和心肌细胞形成的作用与纯BMP抑制剂DMH 1的作用进行比较，所述纯BMP抑制剂DMH 1对Flk 1+没有脱靶活性（目的1）。在ES细胞分化的前24小时期间用BMP抑制剂处理足以进行稳健的心脏诱导，并且心脏诱导与所有非心脏中胚层谱系的显著减少一致。这种反向关系表明，在胚胎干细胞分化的初始阶段，BMP抑制使早期共同祖细胞向心脏特异性发育程序发展。为了测试这一点，将检查DMH 1对中胚层祖细胞发育潜力的影响（目的2）。还将进行DMH 1处理的中胚层细胞的分子谱分析以表征DMH 1诱导的早期心脏祖细胞。Aim 3将采取下一个合乎逻辑的步骤来测试基于小分子的方法在体外强烈诱导心肌细胞形成是否可以对干细胞治疗产生有益的影响，以改善心肌损伤小鼠模型中的心脏重塑和功能。总之，这项研究将利用一类有效的心肌发生化学诱导剂来阐明心脏特化和分化的机制，从而为未来基于干细胞的心脏病治疗策略提供信息。 公共卫生相关性： 不可逆心脏损伤导致的心力衰竭困扰着超过500万美国人，是美国退伍军人残疾和死亡的主要原因之一。除了移植，目前还没有明确的治疗心力衰竭的方法。干细胞可以分化成心脏组织，为修复受损的心脏提供了真实的希望。在过去的几年里，随着从患者自身皮肤中制造干细胞的方法的发展，这种希望变得更加强烈。然而，干细胞治疗面临着许多障碍，特别是很难将干细胞转化为心脏细胞。我们最近发现了一类新型药物，可以显著促进干细胞中的心脏细胞形成。该项目旨在研究这些药物如何促进试管中的心脏细胞形成，并检查它们是否可以增强干细胞对心脏病发作小鼠的有益作用。