Transcriptional Regulation of the Intestinal Epithelium

肠上皮的转录调控

• 批准号: 7952403
• 负责人: MICHAEL P. VERZI
• 金额: $ 14.36万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7952403
• 关键词: Address; Adult; Affect; Arts; Automobile Driving; Binding; Binding Sites; Biological Assay; Biological Models; Biology; CDX2 gene; Cardiovascular system; Cell Differentiation process; Cell Maintenance; Cells; Communities; Complex; Coupling; DNA; Dana-Farber Cancer Institute; Data; Development; Disease; Environment; Epithelial; Epithelial Cells; Epithelium; Equipment; Etiology; Faculty; Functional disorder; Future; Gastrointestinal tract structure; Gene Expression; Gene Targeting; Genes; Genetic; Genetic Models; Genome; Goals; Grant; Hospitals; Immune system; Indium; Individual; Inflammatory; Intestinal Diseases; Intestines; Knock-out; Laboratories; Lead; Maintenance; Malignant Neoplasms; Maps; Mediating; Medical; Mentors; Mitotic; Modeling; Molecular; Mucous body substance; Mus; Natural regeneration; Nutrient; Pattern; Phenotype; Play; Population; Postdoctoral Fellow; Proliferating; Property; Regulator Genes; Research; Resistance; Resources; Role; Scientist; Staging; Stem cells; Technology; Testing; Thick; Tissues; Toxin; Training; Training Programs; Transcriptional Regulation; Villus; Whole Organism; Work; career; chromatin immunoprecipitation; college; gastrointestinal; gastrointestinal function; homeodomain; in vivo; insight; interest; intestinal crypt; intestinal epithelium; loss of function; medical schools; new technology; next generation; nutrition; pathogen; progenitor; programs; public health relevance; research study; stem; transcription factor; transcription factor CDX2

DESCRIPTION (provided by applicant): Candidate and choice of Mentor: The purpose of this K01 application is to continue my training in transcriptional mechanisms of gastrointestinal development and disease with the long-term goal of a career pursuing and hopefully curing the molecular etiologies of GI disorders and diseases. My interest in transcriptional mechanisms began in college and became my focus during graduate training with Dr. Brian Black at UCSF where I studied the transcriptional regulation of MEF2C, a gene with important functions in cardiovascular development. These studies yielded important insights on how an individual gene is regulated. For my postdoctoral work I was interested in expanding these studies to understand not how only one gene was regulated, but to employ new technologies to uncover entire gene regulatory programs. I sought a mentor pursuing the molecular mechanisms of gastrointestinal function with a fantastic track-record in training young scientists with expertise in transcriptional regulation. Ramesh Shivdasani and his laboratory will provide an outstanding training environment to pursue the transcriptional regulatory mechanisms controlling intestinal epithelial functions. Project: The intestine undergoes continual cell turnover as cells differentiate from stem and progenitor cells to differentiated intestinal cells that quickly carry out their functions and then are shed into the lumen. Progenitor and differentiated cells have very different gene expression patterns but the factors controlling these expression patterns are incompletely described. The homeodomain transcription factor CDX2 has the properties of a master regulator of the intestine in that it can dominantly induce intestine-type epithelium in non-intestinal tissues. Because CDX2 is expressed and has known target genes in both progenitor and differentiated cells, it is believed to play a role in mediating gene expression changes that occur during differentiation. Yet despite such profound functions, the molecular details of CDX2 actions are incompletely defined - particularly during the course of differentiation. My proposal applies recent advances in technology (whole genome chromatin immunoprecipitation) to comprehensively describe the molecular details of CDX2 function in both intestinal progenitor cells and their differentiated descendants. Firstly, CDX2 binding sites will be mapped in the genomes of progenitor cells and differentiated cells to determine whether the binding sites change concurrent with cellular state. This work will allow us to define how CDX2 can mediate gene expression changes during differentiation. Secondly, we have preliminary evidence to suggest CDX2 differentially cooperates with specific transcription factors in progenitor and differentiated cells, GATA6 and HNF4(, respectively. Whether CDX2 partners with these transcription factors and how these multi-factor complexes are assembled on the DNA will be determined. Finally, a proper genetic model to determine the requirement for CDX2 in the adult intestine will be generated. An inducible knockout of CDX2 will be analyzed to test the hypothesis that this factor is required for intestinal differentiation in the homeostatic adult intestine. Together, these experiments will provide molecular insights into how an important transcription factor mediates intestinal differentiation. This work will hopefully open avenues for future studies as an independent scientist where I hope to define gene programs susceptible to insults that result in intestinal disorders and cancers. Training Environment. The Dana Farber Cancer Institute and the affiliated hospitals of Harvard Medical School together provide tremendous resources to execute this training plan. Several instructional programs have been established to help transition late-stage postdoctoral fellows into independent scientists. In addition to full access to all necessary state-of-the-art research equipment and facilities, the Harvard Medical Community will be an asset by providing access to outstanding faculty from which I have assembled a mentoring committee comprised of experts in gastrointestinal biology and transcriptional mechanisms that will oversee my training progress and council me in my pursuit of an independent research program. Together with a strong mentor, well-founded research program and training plan, I hope this proposal will provide a strong beginning to a career investigating the molecular underpinnings of GI disease. PUBLIC HEALTH RELEVANCE: The intestinal epithelium is a one-cell-thick layer that is permissive to nutrients while resistant to toxins and pathogens within the intestinal lumen. This critical epithelial layer is susceptible to inflammatory diseases and cancer making it imperative to understand the molecular framework upon which normal functions are built. The proposed training grant will focus on developing a career pursuing the underlying transcriptional mechanisms of intestinal epithelial cell maintenance.

描述（由申请人提供）： 导师的候选人和选择：这个K 01应用程序的目的是继续我的胃肠道发育和疾病的转录机制的培训，追求并希望治愈胃肠道疾病和疾病的分子病因学的职业生涯的长期目标。我对转录机制的兴趣始于大学，并成为我在UCSF与Brian Black博士研究生培训期间的重点，在那里我研究了MEF 2C的转录调控，MEF 2C是一种在心血管发育中具有重要功能的基因。这些研究对个体基因是如何调控的产生了重要的见解。对于我的博士后工作，我有兴趣扩展这些研究，以了解不仅仅是一个基因是如何调控的，而是采用新技术来揭示整个基因调控程序。我寻找了一位导师，他追求胃肠道功能的分子机制，在培养具有转录调控专业知识的年轻科学家方面有着出色的记录。Ramesh Shivdasani和他的实验室将提供一个优秀的培训环境，以追求控制肠上皮功能的转录调控机制。 项目名称：随着细胞从干细胞和祖细胞分化为分化的肠细胞，肠细胞经历持续的细胞更新，所述分化的肠细胞快速执行其功能，然后脱落到管腔中。祖细胞和分化的细胞具有非常不同的基因表达模式，但控制这些表达模式的因素并不完全描述。同源结构域转录因子CDX 2具有肠的主调节因子的性质，因为它可以在非肠组织中显性诱导结肠上皮型上皮。由于CDX 2在祖细胞和分化细胞中表达并具有已知的靶基因，因此认为其在介导分化期间发生的基因表达变化中起作用。然而，尽管有如此深刻的功能，CDX 2作用的分子细节并不完全确定-特别是在分化过程中。 我的建议应用最新的技术进展（全基因组染色质免疫沉淀）来全面描述肠道祖细胞及其分化后代中CDX 2功能的分子细节。首先，将在祖细胞和分化细胞的基因组中定位CDX 2结合位点，以确定结合位点是否与细胞状态同时变化。这项工作将使我们能够确定CDX 2如何在分化过程中介导基因表达的变化。其次，我们有初步的证据表明，CDX 2与祖细胞和分化细胞中的特异性转录因子GATA 6和HNF 4（分别为）有差异地合作。将确定CDX 2是否与这些转录因子配对以及这些多因子复合物如何在DNA上组装。最后，将产生适当的遗传模型来确定成人肠道中对CDX 2的需求。将分析CDX 2的诱导型敲除，以检验该因子是稳态成人肠中肠分化所需的假设。总之，这些实验将提供一个重要的转录因子如何介导肠道分化的分子见解。作为一名独立科学家，这项工作有望为未来的研究开辟道路，我希望定义容易受到导致肠道疾病和癌症的侮辱的基因程序。 训练环境。达纳法伯癌症研究所和哈佛医学院的附属医院一起提供了巨大的资源来执行这个培训计划。已经建立了几个教学计划，以帮助后期博士后过渡到独立的科学家。除了可以充分使用所有必要的最先进的研究设备和设施外，哈佛医学界还可以提供优秀的教师，我已经组建了一个由胃肠道生物学和转录机制专家组成的指导委员会，他们将监督我的培训进度，并在我追求独立研究计划时为我提供理事会。再加上一个强大的导师，有充分依据的研究计划和培训计划，我希望这个建议将提供一个强有力的开始，以调查胃肠道疾病的分子基础的职业生涯。 公共卫生相关性： 肠上皮是一个单细胞厚的层，其允许营养物质，同时抵抗肠腔内的毒素和病原体。这一关键的上皮层易受炎性疾病和癌症的影响，因此必须了解正常功能所依赖的分子框架。拟议的培训补助金将侧重于发展追求肠上皮细胞维持的潜在转录机制的职业生涯。