Epicardial progenitors in the developing and postnatal heart

发育中和出生后心脏中的心外膜祖细胞

• 批准号: 8898180
• 负责人: William Tswenching Pu
• 金额: $ 44.13万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8898180
• 关键词: Adult; Animals; Blood Vessels; Blood capillaries; Bone Marrow; Cardiac; Cardiac Myocytes; Cells; Clinical; Clinical Research; Coronary; Data; Development; EFRAC; Endothelial Cells; Epicardium; Epithelium; Fetal Heart; Fibroblasts; Genetic; Genetic screening method; Goals; Growth; Health; Heart; Heart Diseases; Heart Injuries; Heart failure; Homeostasis; IGF1 gene; Infarction; Knowledge; Label; Lead; MAP Kinase Gene; Mesenchymal; Messenger RNA; Modeling; Molecular; Morbidity - disease rate; Myocardial; Myocardial Infarction; Myocardium; Myofibroblast; NRG1 gene; Natural regeneration; Nephroblastoma; Outcome; Paracrine Communication; Pathway interactions; Perfusion; Population; Pre-Clinical Model; Process; Property; Regulation; Research Project Grants; Role; Signal Pathway; Signal Transduction; Smooth Muscle Myocytes; Stem cells; Technology; Testing; Therapeutic; Time; Translating; Translations; Tumor Suppressor Proteins; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factor Receptor-2; Vascular Endothelial Growth Factors; Vascular blood supply; WT1 gene; Wilms Tumor Suppressor 1; capillary; cardiac regeneration; cardiac repair; cell behavior; density; design; effective therapy; epithelial to mesenchymal transition; fetal; improved; injured; insight; loss of function; mortality; novel; novel therapeutics; paracrine; postnatal; progenitor; regenerative; repaired; research study; response to injury; small molecule; thymosin beta(4); transcription factor; vasculogenesis

DESCRIPTION (provided by applicant): Heart failure is the leading cause of morbidity and mortality world-wide. Current heart failure treatments are not effective in enhancing myocardial repair or regenerating lost heart muscle. Improving myocardial repair after myocardial infarction will require enhancing vascular supply to regions with marginal perfusion and stimulating myocardial regeneration through formation of new cardiomyocytes and supporting vasculature. The epicardium, a polarized epithelium covering the heart, is an essential regulator of fetal myocardial growth and coronary vasculogenesis. Epicardium and myocardium engage in elaborate paracrine signaling to regulate each other's development. Furthermore, epicardial cells undergo epithelial to mesenchymal transition (EMT), generating epicardium-derived mesenchymal cells (EPDCs) that migrate into the heart and differentiate into fibroblasts, vascular smooth muscle cells, endothelial cells, and potentially cardiomyocytes. In the adult heart, epicardium is an important modulator of the myocardial injury response, and recent studies indicate that the developmental properties of epicardium may be harnessed for therapeutic regeneration. Our preliminary data show that chemically modified mRNA (m*RNA) drives transient, high level paracrine factor expression in the heart. VEGF-A m*RNA, delivered once at the time of experimental myocardial infarction (MI), enhanced capillary density, reduced infarct size, improved ejection fraction, and enhanced survival for up to one year. Epicardial progenitors, marked by expression of the transcription factor Wt1 (Wilms Tumor Suppressor 1), were a major target of VEGF-A m*RNA activity. VEGF-A expanded and mobilized post-MI WT1+ epicardial progenitors. Remarkably, VEGF-A m*RNA altered the fate of these cells, enhancing their differentiation into endothelial cells and cardiomyocytes and reducing their differentiation into myofibroblasts. Our data suggest a novel therapeutic paradigm, in which brief activation of paracrine signaling pathways alters resident progenitor cell fate to achieve sustained therapeutic benefit. This cell-free therapeutic paradigm can be readily translated to large animal and clinical studies. In this proposal, we further investigate the regulation of adul epicardial cell behavior develop the therapeutic paradigm advanced by our preliminary data, through the following Specific Aims: (1) Determine the mechanism by which VEGF-A redirects EPDC fate. (2) Define the role of Wt1 in regulating adult epicardial progenitor activity in the normal and injured adult heart. (3) Identify additional factors with beneficial activity in myocardal infarction. By combining novel m*RNA technology with the Pu lab's established expertise in epicardial progenitors and their role in fetal and adult heart, this proposal will lead to mechanistic insights into myocardial regeneration, advance application of m*RNA technology to myocardial regeneration, and lead to new avenues for clinical translation.

描述(由申请人提供)：心力衰竭是全球发病率和死亡率的主要原因。目前的心力衰竭治疗在加强心肌修复或再生丢失的心肌方面并不有效。改善心肌梗死后的心肌修复需要增加对边缘灌注区的血管供应，并通过形成新的心肌细胞和支持血管系统来刺激心肌再生。心外膜是一种覆盖在心脏上的极化上皮，是胎儿心肌生长和冠状动脉血管生成的重要调节因子。心外膜和心肌参与复杂的旁分泌信号，以调节彼此的发育。此外，心外膜细胞经历上皮间充质转化(EMT)，产生心外膜来源的间充质细胞(EPDCs)，迁移到心脏并分化为成纤维细胞、血管平滑肌细胞、内皮细胞和潜在的心肌细胞。在成人心脏中，心外膜是心肌损伤反应的重要调节因子，最近的研究表明，心外膜的发育特性可能被用于治疗性再生。我们的初步数据显示，化学修饰的信使核糖核酸(m*RNA)在心脏中驱动瞬时的、高水平的旁分泌因子表达。在实验性心肌梗死(MI)时注射一次的VEGF-A m*RNA可增加毛细血管密度，缩小梗死面积，改善射血分数，并提高长达一年的存活率。心外膜前体细胞以转录因子Wt1(Wilms肿瘤抑制因子1)的表达为标志，是血管内皮生长因子-A m*RNA活性的主要靶点。血管内皮生长因子-A扩增和动员心肌梗死后WT1+心外膜祖细胞。值得注意的是，VEGF-A m*RNA改变了这些细胞的命运，促进了它们向内皮细胞和心肌细胞的分化，减少了它们向肌成纤维细胞的分化。我们的数据提示了一种新的治疗模式，即短暂激活旁分泌信号通路改变常驻祖细胞的命运，以实现持续的治疗效果。这种无细胞的治疗模式可以很容易地转化为大型动物和临床研究。在这个方案中，我们进一步研究了肾上腺心外膜细胞行为的调节，开发了我们初步数据提出的治疗范例，通过以下具体目的：(1)确定血管内皮生长因子-A重定向EPDC命运的机制。(2)明确Wt1在正常和损伤成人心脏中对成体心外膜祖细胞活性的调节作用。(3)找出心肌梗死中具有有益活性的其他因素。通过将新的m*RNA技术与Pu实验室在心外膜前体细胞及其在胎儿和成人心脏中的作用方面的成熟专业知识相结合，这项建议将导致对心肌再生的机械性见解，推动m*RNA技术在心肌再生中的应用，并为临床翻译开辟新的途径。