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: 8443831
• 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/8443831
• 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.

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职业发展培训计划。主要研究者在斯坦福大学医学院获得医学博士/博士学位，并在马萨诸塞州总医院 (MGH) 完成了内科、心脏病学和介入心脏病学的临床培训。他现在将在 Kenneth Chien 博士的指导下专注于干细胞和发育生物学的研究，因为它与心脏病有关。 Chien 博士是心脏发育领域的领军人物，是麻省总医院心血管研究中心 (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。他培养了许多医学科学家。为了促进干细胞生物学的培训，首席研究员已经与干细胞生物学先驱Stuart Orkin博士一起接受了一年的培训。奥金博士将继续在培训首席研究员作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中担任指导职务。 CVRC 和 HSCI 为心脏发育和干细胞生物学快速融合领域的医师科学家培训提供了理想的环境。该研究计划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和发病的主要原因，许多对心脏发育重要的基因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学基础至关重要，并将有助于再生医学的科学基础。最近，被称为 microRNA (miRNA) 的小非编码 RNA 分子已被证明可以通过滴定关键蛋白质的剂量来调节基因表达。尽管一些 miRNA 在发育中的心脏中富集，并且似乎控制心肌扩张和分化的平衡，但心脏 miRNA 的完整时间和空间库尚未建立。哺乳动物心脏由两组密切相关的心脏祖细胞发育而来，第一心区（FHF）产生左心室（LV），第二心区（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来开发双色转基因小鼠系统。因此，我们能够从体外分化的胚胎和胚胎干细胞中纯化 FHF 和 SHF 祖细胞，并鉴定出一组在两个心脏谱系中差异表达的 miRNA。值得注意的是，我们鉴定出 miR200a 和 miR200b (miR200)，这两种以多顺反子方式转录的密切相关的 miRNA，是第一个对发育中的心脏内的早期 FHF 祖细胞具有特异性的 miRNA，并且在初步实验中证明它们似乎在该谱系的正常发育中发挥着关键作用。我们假设 miR200 通过促进 FHF 祖细胞扩增和分化并抑制向其他谱系的分化来调节心脏发育。我们进一步假设 miR200 通过控制特定靶基因发挥功能，并且对于成熟哺乳动物心脏的正常形态发生和功能是必需的。为了测试这一点，我们提出以下具体目标：1）确定miR200是否通过支持中胚层分化并抑制内胚层和外胚层分化来促进FHF发育； 2）确定miR200控制FHF发生的机制； 3)确定miR200在胚胎发育过程中的作用。这里开发的工具和理解将有助于心脏再生疗法的科学基础。