Role of TGF-? Signaling in Embryonic Stem Cell Maintenance and Endodermal Differe

TGF-的作用？

• 批准号: 8431397
• 负责人: ALAN C MULLEN
• 金额: $ 15.92万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8431397
• 关键词: Advisory Committees; B-Lymphocytes; Binding; Binding Sites; Biological Assay; Cell Cycle Arrest; Cell Line; Cell Maintenance; Cell Nucleus; Cell Therapy; Cells; Cellular biology; Cirrhosis; Clinical; Clinical Immunology; Co-Immunoprecipitations; Committee Members; DNA; DNA Binding; Data; Development; Doctor of Philosophy; Ectopic Expression; Endoderm; Environment; Family; Gastroenterology; Gene Expression Regulation; Gene Targeting; General Hospitals; Genes; Genetic Transcription; Genomics; Goals; Hepatocyte; Human; Human Development; Institutes; Knowledge; Laboratories; Learning; Liver; Liver diseases; Luciferases; Maintenance; Massachusetts; Mentors; Modeling; Molecular Genetics; Mus; Muscle Cells; Mutation Analysis; Neoplasm Metastasis; Pancreas; Phosphorylation; Physicians; Play; Population; Process; Production; Proteins; RNA Interference; Recruitment Activity; Regenerative Medicine; Reporter; Reporting; Research; Research Personnel; Role; Scientist; Signal Pathway; Signal Transduction; Site; Systems Biology; Training; Work; cell type; direct application; embryonic stem cell; experience; genome-wide; human disease; human embryonic stem cell; improved; interest; planetary Atmosphere; pluripotency; precursor cell; protein protein interaction; public health relevance; receptor; research and development; research study; response; stem cell biology; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): TGF-2 signaling directs diverse cellular responses including differentiation, proliferation, and cell cycle arrest and through these responses plays a central role human development and disease. Activation of the TGF-2 receptor leads to phosphorylation of the transcription factors, Smad2 and Smad3 (Smad2/3). Once phosphorylated, Smad2/3 accumulates in the nucleus where they must interact with other transcription factors in order to bind DNA and regulate transcription. The mechanism by which activation of Smad2/3 directs such diverse responses remains unclear. Specific transcription factors have been reported to interact with Smad2/3 but these transcription factors are present in many different cell types and interact with Smad2/3 at only a few genes. Our preliminary data provides a clue to understand the diverse effects of TGF-2 signaling. We found that lineage-specific transcription factors may determine which genes Smad2/3 regulate. TGF-2 signaling is required to maintain human embryonic stem cells and is also required to direct embryonic stem cells to differentiate into endoderm, which will give rise to the cells of the liver, gut and pancreas. ES cells can be differentiated into hepatocytes, but low yields and contaminating cells are major hurdles to overcome in growing hepatocytes for human therapy. The goal of this project is to understand how TGF-2 signaling can direct endodermal differentiation and use this knowledge to improve our ability to grow hepatocytes for use in regenerative medicine. To achieve these goals the project will 1) identify the key transcription factors that co- occupy DNA sites with Smad2/3 in human ES cells, 2) identify key transcription factors that co-occupy DNA sites with Smad2/3 during endodermal differentiation and are required for endodermal differentiation, and 3) determine which factors directly interact with Smad2/3 to recruit them to bind DNA in embryonic stem cells and during endodermal differentiation. Identification of specific protein-protein interactions that determine how developing cells respond to TGF-2 signaling would provide potential targets to modulate TGF-2 signaling in during development and improve the ability to produce hepatocytes and pancreatic cells for therapy. This research will be performed by Dr. Mullen in the laboratory of Dr. Richard Young at the Whitehead Institute, a leader in the fields of stem cell biology, transcription and genomics. Dr. Mullen received his Ph.D. training in immunology and clinical training in gastroenterology. He is building on a background in molecular genetics and cell biology and a clinical interest in liver disease to develop a proposal to apply genomics and systems biology to understand the role of TGF-2 signaling in embryonic stem cells maintenance and endodermal differentiation. The Whitehead Institute is the ideal environment in which to perform this research given the collaborative atmosphere, facilities, educational opportunities and experience training successful physician scientist. Dr. Mullen will also work closely with his co-mentor at Massachusetts General Hospital, Dr. Ramnik Xavier who has expertise in genomics and application of systems biology to signaling pathways. In addition, Dr. Mullen has formed an advisory committee to support his research and his development into an independent investigator. The committee members are experts in stem cell biology, development and signal transduction and have extensive experience mentoring physician scientists. !

描述(申请人提供)：转化生长因子-2信号引导不同的细胞反应，包括分化、增殖和细胞周期停滞，并通过这些反应在人类发育和疾病中发挥核心作用。转化生长因子-2受体的激活导致转录因子Smad2和Smad3(Smad2/3)的磷酸化。一旦被磷酸化，Smad2/3就会聚集在细胞核中，在那里它们必须与其他转录因子相互作用，才能结合DNA并调节转录。Smad2/3的激活是如何引导这种不同反应的机制尚不清楚。已有研究报道Smad2/3与特定的转录因子相互作用，但这些转录因子存在于许多不同的细胞类型中，并且只在少数基因上与Smad2/3相互作用。我们的初步数据为理解转化生长因子-2信号的不同作用提供了线索。我们发现，谱系特异的转录因子可能决定了Smad2/3调节哪些基因。转化生长因子-2信号是维持人类胚胎干细胞所必需的，也是引导胚胎干细胞分化为内胚层所必需的，内胚层将产生肝脏、肠道和胰腺的细胞。ES细胞可以分化为肝细胞，但产量低和污染细胞是培养肝细胞用于人类治疗的主要障碍。这个项目的目标是了解转化生长因子-2信号如何引导内胚层分化，并利用这一知识来提高我们培养肝细胞用于再生医学的能力。为了实现这些目标，该项目将1)确定在人类ES细胞中与Smad2/3共占据DNA位点的关键转录因子，2)确定在内胚层分化过程中与Smad2/3共占据DNA位点且是内胚层分化所必需的关键转录因子，以及3)确定哪些因子直接与Smad2/3相互作用以招募它们在胚胎干细胞和内胚层分化过程中结合DNA。识别特定的蛋白质-蛋白质相互作用决定了发育细胞对转化生长因子-2信号的反应，这将为在发育过程中调节转化生长因子-2信号提供潜在的靶点，并提高产生肝细胞和胰腺细胞用于治疗的能力。这项研究将由马伦博士在怀特黑德研究所理查德·杨博士的实验室进行，他是干细胞生物学、转录和基因组学领域的领先者。马伦博士接受了免疫学博士培训和胃肠病学临床培训。他在分子遗传学和细胞生物学的背景以及对肝病的临床兴趣的基础上，提出了一项应用基因组学和系统生物学来了解转化生长因子-2信号在胚胎干细胞维持和内胚层分化中的作用的建议。怀特黑德研究所是进行这项研究的理想环境，因为那里有合作的氛围、设施、教育机会和培养成功的内科科学家的经验。马伦还将与他在马萨诸塞州总医院的导师拉姆尼克·泽维尔博士密切合作，后者在基因组学和系统生物学在信号通路中的应用方面拥有专业知识。此外，马伦博士还成立了一个顾问委员会，以支持他的研究和发展成为一名独立调查员。委员会成员是干细胞生物学、发育和信号转导方面的专家，并拥有指导内科科学家的丰富经验。好了！