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）： 不可逆转的心脏组织损伤导致的心力衰竭是美国残疾和死亡率的主要原因。由于心脏的内在能力可以忽略不计，可以再生新的组织以替代因受伤而损失的组织，因此除了器官移植外，目前没有明确的心力衰竭治疗。最近的研究介绍了用来自外源多能干细胞或内源性心血管祖细胞衍生的健康心肌细胞替代受损的心脏组织的前景。治疗使用特别有希望的是胚胎茎（ES）细胞和自体诱导的多能干（IPS）细胞，这些细胞已被确定能够区分心肌细胞。然而，意识到干细胞的全部治疗潜力面临许多障碍，包括肿瘤形成的潜力，较低的心肌细胞形成率以及对哪些祖细胞成为心肌细胞的方式和哪些祖细胞的理解不足。缺乏药物来促进干细胞的治疗作用，也阻碍了目前的努力。后型肌吗啡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中体外心肌生成的最有效的化学诱导剂之一。但是，BMP抑制剂如何在ES细胞中诱导心脏形成。奇怪的是，在没有明显增加中胚层标记表达的情况下，心肌细胞诱导发生。由于背端词也具有对中胚层的关键型flk-1受体激酶的显着活性，因此明显的悖论可能是由于这种脱靶效应所致。为了测试这一点并鉴定具有最高心脏诱导能力的化合物，将将背词素对中胚层和心肌细胞形成的影响与纯BMP抑制剂DMH1的作用进行比较，后者没有针对FLK1+的非目标活性（AIM 1）。在ES细胞分化的最初24小时内用BMP抑制剂的治疗足以鲁棒性心脏诱导，并且心脏诱导与所有非心脏中胚层谱系的显着降低相吻合。这种反相关关系表明，在ES细胞分化的初始阶段的BMP抑制作用会提交早期的公共祖细胞，以实现心脏特异性发育计划。为了测试这一点，将检查DMH1对中胚层祖细胞细胞发育潜力的影响（AIM 2）。还将进行DMH1处理过的中胚层细胞的分子分析，以表征由DMH1诱导的早期心脏祖细胞。 AIM 3将采取下一个逻辑步骤来测试在体外诱导心肌细胞形成的小分子方法是否对干细胞疗法产生有益的影响，以改善心肌损伤小鼠模型中心脏重塑和功能。总之，拟议的研究将利用一类强有力的心肌生成化学诱导剂来阐明心脏规格和分化的机制，从而为未来的基于干细胞的治疗心脏病的策略提供了信息。 公共卫生相关性： 不可逆转的心脏损伤因超过500万美国人而受到的心力衰竭，是美国退伍军人残疾和死亡的主要原因之一。除了移植外，目前尚无心力衰竭的明确治疗方法。可以分化为心脏组织的干细胞为修复受损的心脏提供了真正的希望。在过去的几年中，这种希望随着方法从患者自己的皮肤制造干细胞的发展而变得越来越强烈。但是，干细胞疗法面临许多障碍，尤其是很难将干细胞变成心脏细胞的事实。我们最近发现了一类新型药物，这些药物会大大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测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患有心脏病发作的小鼠的有益作用。