Control of Cardiac Lineage Commitment and Differentiation in Murine Development

小鼠发育中心脏谱系承诺和分化的控制

• 批准号: 8238397
• 负责人: IBRAHIM J DOMIAN
• 金额: $ 13.8万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8238397
• 关键词: Adult; Advisory Committees; Affect; American; Area; Biology; Cardiac; Cardiology; Cardiovascular Diseases; Cardiovascular system; Clinical; Color; Committee Members; Congenital Abnormality; Defect; Development; Developmental Biology; Diagnosis; Disease; Doctor of Philosophy; ES Cell Line; Ectoderm; Embryo; Embryonic Development; Endoderm; Equilibrium; Event; Family; Functional RNA; Future; Gene Expression; Gene Targeting; General Hospitals; Genes; Genetic Markers; Heart; Heart Diseases; Hospitalization; Human; In Situ Hybridization; In Vitro; Institutes; Internal Medicine; Knock-in Mouse; Left ventricular structure; Massachusetts; Mentorship; Mesoderm; MicroRNAs; Molecular; Morbidity - disease rate; Morphogenesis; Mus; Myocardial; Pathway interactions; Phenotype; Physicians; Physiological; Physiology; Play; Population; Program Development; Proteins; Regenerative Medicine; Research; Research Personnel; Right ventricular structure; Role; Scientist; Small RNA; Stem cells; System; Testing; Training; Training Programs; Transgenic Mice; Transgenic Organisms; United States; Ventricular septum; Work; base; career; career development; congenital heart disorder; dosage; embryonic stem cell; homeodomain; in vivo; islet; loss of function; medical schools; mortality; progenitor; programs; public health relevance; recombinase; regenerative therapy; research study; stem cell biology; tool; transcription factor

DESCRIPTION (provided by applicant): This proposal describes a five-year training program for the development of an academic career in Cardiology. The principle investigator obtained his MD/PhD from Stanford School of Medicine and has completed clinical training in Internal Medicine, Cardiology, and Interventional Cardiology at Massachusetts General Hospital (MGH). He will now focus on the study of stem cell and developmental biology as it pertains to cardiac disease under the mentorship of Dr. Kenneth Chien. Dr. Chien, a leader in the field of cardiac development, is chief of the Cardiovascular Research Center (CVRC) at the MGH and Leader of the Cardiovascular Disease Program at the Harvard Stem Cell Institute (HSCI). He has trained numerous physician scientists. To promote training in stem cell biology, the principle investigator has already spent one year training with Dr. Stuart Orkin, a pioneer in stem cell biology. Dr. Orkin will continue to play a prominent role in training the principle investigator as an Advisory Committee member. In addition, Dr. Kenneth Bloch and Dr. Randall Peterson, both recognized leaders in cardiovascular biology, will serve mentorship roles on the Advisory Committee. The CVRC and the HSCI provide an ideal setting for training physician- scientists in the rapidly converging areas of cardiac development and stem cell biology. The research program will focus on lineage commitment and differentiation during murine cardiac development. Acquired and congenital heart disease represents a leading cause of mortality and morbidity in the world and many of the genes important in cardiac development have been implicated in human congenital heart disease. Defining the molecular pathways that control cardiac development is essential to understanding the pathophysiologic basis of these diseases and will contribute to the scientific basis of regenerative medicine. Recently, small non-coding RNA molecules called microRNAs (miRNAs) have been shown to regulate gene expression by titrating the dosage of critical proteins. Although several miRNAs are enriched in the developing heart and appear to control the balance of myocardial expansion and differentiation, the full temporal and spatial repertoire of cardiac miRNAs has yet to be established. The mammalian heart develops from two closely related sets of cardiac progenitors, first heart field (FHF) which gives rise to the left ventricle (LV) and the second heart field (SHF) which gives rise to the right ventricle (RV) and outflow tract (OFT). To investigate the role of miRNAs in controlling the development of these lineages, we have used distinct genetic markers to develop a two-color transgenic murine system. We were thereby able to purify FHF and SHF progenitors from embryos and embryonic stem cells differentiating in vitro, and to identify a set of miRNAs that are differentially expressed in the two cardiac lineages. Significantly we identify miR200a and miR200b (miR200), two closely related miRNAs transcribed in a polycistronic fashion, as the first miRNAs specific for early FHF progenitors within the developing heart and in preliminary experiments demonstrate that they appear to play a key role in the normal development of that lineage. We hypothesize that miR200 regulates cardiac development by promoting FHF progenitor expansion and differentiation and suppressing commitment to other lineages. We further hypothesize that miR200 functions by controlling specific target genes and is necessary for normal morphogenesis and function of the mature mammalian heart. To test this, we propose the following specific aims: 1) Determine if miR200 is promotes FHF development by supporting mesoderm differentiation and suppressing endoderm and ectoderm differentiation; 2) Determine the mechanisms by which miR200 controls FHF development; 3) Determine the role of miR200 during embryonic development. The tools and understanding developed here will contribute to the scientific basis of cardiac regenerative therapies. PUBLIC HEALTH RELEVANCE: Heart disease affects millions of Americans every year and is a leading cause of hospitalization in the United States. Understanding how the heart develops will help us understand how the heart becomes diseased. This study will give us clues for the future on how to diagnose and treat cardiac birth defects and adult diseases.

描述（由申请人提供）：该提案描述了一个为期五年的心脏病学学术生涯发展培训计划。主要研究者在斯坦福医学院获得医学博士学位，并在马萨诸塞州总医院（MGH）完成了内科、心脏病学和介入性心脏病学的临床培训。他现在将专注于干细胞和发育生物学的研究，因为它与心脏疾病有关。简博士是心脏发育领域的领导者，是MGH心血管研究中心（CVRC）的主任，也是哈佛干细胞研究所（HSCI）心血管疾病项目的负责人。他培养了许多内科科学家。为了促进干细胞生物学的培训，首席研究员已经花了一年的时间与干细胞生物学的先驱斯图亚特·奥金博士一起培训。Orkin博士将继续在培训主要研究者成为咨询委员会成员方面发挥重要作用。此外，心血管生物学领域公认的领导者Kenneth Bloch博士和Randall Peterson博士将在咨询委员会担任指导角色。CVRC和HSCI为在心脏发育和干细胞生物学快速融合的领域培训医师科学家提供了理想的环境。该研究项目将重点关注小鼠心脏发育过程中的谱系承诺和分化。获得性和先天性心脏病是世界上死亡率和发病率的主要原因，许多在心脏发育中重要的基因都与人类先天性心脏病有关。定义控制心脏发育的分子途径对于理解这些疾病的病理生理基础至关重要，并将有助于再生医学的科学基础。最近，被称为microRNAs （miRNAs）的小非编码RNA分子被证明可以通过滴定关键蛋白质的剂量来调节基因表达。虽然有几种mirna在发育中的心脏中富集，并似乎控制心肌扩张和分化的平衡，但心脏mirna的完整时空库尚未确定。哺乳动物的心脏由两组密切相关的心脏祖细胞发育而来，第一心野（FHF）产生左心室（LV），第二心野（SHF）产生右心室（RV）和流出道（OFT）。为了研究mirna在控制这些谱系发育中的作用，我们使用不同的遗传标记开发了一个双色转基因小鼠系统。因此，我们能够从胚胎和体外分化的胚胎干细胞中纯化FHF和SHF祖细胞，并鉴定出一组在两种心脏谱系中差异表达的mirna。值得注意的是，我们确定了miR200a和miR200b (miR200)，这两个密切相关的mirna以多顺子方式转录，作为发育中的心脏中早期FHF祖细胞特异性的第一个mirna，并在初步实验中证明它们似乎在该谱系的正常发育中发挥关键作用。我们假设miR200通过促进FHF祖细胞的扩张和分化以及抑制对其他谱系的承诺来调节心脏发育。我们进一步假设miR200通过控制特定的靶基因发挥功能，并且是成熟哺乳动物心脏正常形态发生和功能所必需的。为了验证这一点，我们提出了以下具体目标：1)确定miR200是否通过支持中胚层分化和抑制内胚层和外胚层分化来促进FHF的发展；2)确定miR200控制FHF发展的机制；3)确定miR200在胚胎发育中的作用。这里发展的工具和理解将有助于心脏再生治疗的科学基础。