Mechanisms of gastrointestinal cell responses to Notch Signaling

胃肠道细胞对Notch信号反应的机制

• 批准号: 8354133
• 负责人: Tae- Hee Kim
• 金额: $ 9万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8354133
• 关键词: Adult; Area; Award; Binding; Biochemistry; Bioinformatics; Biological Models; Biology; Cell Count; Cell Differentiation process; Cell Lineage; Cell Proliferation; Cells; ChIP-seq; Clinical; Collaborations; Congenital Disorders; Coupled; DNA Sequence; Dana-Farber Cancer Institute; Data; Data Set; Defect; Development; Digestive System Disorders; Disease; Embryo; Enhancers; Enteroendocrine Cell; Environment; Epigenetic Process; Epithelial; Epithelial Cell Proliferation; Epithelial Cells; Epithelium; Faculty; Foundations; Future; Gastrointestinal Diseases; Gastrointestinal tract structure; Gene Expression; Gene Targeting; Genes; Genetic; Genetic Transcription; Genome; Genomics; Goals; Homologous Gene; Inflammation; Institutes; Intestines; Knockout Mice; Knowledge; Learning; Life; Malignant Neoplasms; Maps; Mediating; Mentors; Mentorship; Metaplasia; Methods; Molecular; Molecular Biology; Mus; Organ; Paper; Pathway interactions; Phase; Play; Postdoctoral Fellow; Principal Investigator; Process; Proteins; Publications; Publishing; Recruitment Activity; Regulation; Research; Research Personnel; Risk; Role; Scientist; Secretory Cell; Signal Pathway; Signal Transduction; Staging; Stem cells; Stomach; Surface; Systems Biology; T cell factor 4; Testing; Training; base; career; cell type; chromatin immunoprecipitation; crypt cell; design; developmental genetics; epigenomics; fetal; gastrointestinal; genome-wide; graduate student; improved; in vivo; insight; interest; intestinal crypt; medical schools; new technology; next generation; notch protein; novel; overexpression; progenitor; programs; promoter; protein function; response; self-renewal; stem; stem cell biology; stem cell division; tool; transcription factor; tumorigenesis

DESCRIPTION (provided by applicant): I am interested in understanding the relationship between normal development and mechanisms of disease. I therefore built a strong foundation in molecular biology, biochemistry and developmental genetics as a graduate student. As a postdoctoral fellow, I have used the digestive tract as a model system to study fundamental developmental questions of stem cell renewal and differentiation in fetal and adult mice. Notch signaling plays critical roles in these processes. Using powerful mouse genetic tools, I have demonstrated roles for Notch signaling and its key downstream intestine-restricted transcription factor Atoh1 in gut stem and progenitor cell proliferation, dedifferentiation and cancer, leading t 4 first-author publications. To further understand mechanisms of gastrointestinal cell response to Notch signaling in epithelial cells, I now aim to investigate transcription factors that act downstream of Notch signaling. To systemically identify novel transcription factors that play important roles in intestinal cell differentiation and study the underlying transcriptional mechanisms, I will learn and apply the new genome-wide approach of chromatin immunoprecipitation coupled with high-throughput DNA sequencing (ChIP-Seq). I will analyze genome-wide binding of the secretory transcription factors Atoh1 and Tcf4, and test specific mechanistic hypotheses regarding their interactions in cell replication and in differentiation of te intestinal secretory cell lineage. In the stomach, which does not express the crucial downstream factor Atoh1, I will test the novel hypothesis that a stomach-restricted homologue, Ascl1, acts downstream of Notch signaling to regulate epithelial cell proliferation and enteroendocrine differentiation. The studies I propose will hence provide novel and significant insights into central mechanisms of gastrointestinal epithelial differentiation and help illuminate the molecular basis of diseases ranging from congenital disorders and inflammation to cancer. I aim to become an independent principal investigator in the area of gastrointestinal biology, with expertise in lineage differentiation. A K99/R00 award will facilitate my transition to full independence through sequential mentored and independent phases. In the short-term, this award will allow me to learn new technologies including ChIP-Seq and bioinformatics analysis, hence broadening my expertise to include knowledge of systems biology and genomics, under the mentorship of Ramesh Shivdasani. His lab has successfully completed projects and published important papers that apply such approaches, providing a perfect training environment. Furthermore, the exceptional institutional environment at the Dana-Farber Cancer Institute and Harvard Medical School will further enable my transition to independence by providing institutional programs, facilities, opportunities for collaboration, and broad mentorship My mentorship committee includes world-leading Harvard faculty in the fields of gastrointestinal biology, transcription and genomics to provide guidance and support towards developing my own research program. Furthermore, the Harvard Stem Cell Institute and the Center for Functional Cancer Epigenetics (CFCE) at Dana-Farber Cancer institute will not only give me outstanding opportunities to refine my methods but will also allow me to interact and collaborate with eminent scientists in stem cell biology and epigenomics. Thus, a K99/R00 award will provide critical support at a crucial stage in my career and permit me to make a long-term commitment toward studying the unique biology that underlies gastrointestinal diseases. In the long-term future as a successful independent investigator, I will devote myself to understanding basic mechanisms of gastrointestinal diseases, leading collaborative efforts with clinical and computational biologists, and educating the next generation of basic and clinical scientists. PUBLIC HEALTH RELEVANCE: The gastrointestinal surface is continually replenished through the activity of stomach and intestinal stem cells that differentiate into specialized cell types. Although these cells harbor the risk of developing diseases such as cancer and inflammation, understanding of their molecular regulation is incomplete. This proposal for a K99/R00 award focuses on important organ-specific transcription factors, i.e., proteins that control hundreds of other genes, and I propose to study how these proteins function within a prominent developmental signaling pathway known as Notch. These studies will help define molecular mechanisms of gastrointestinal cell differentiation and identify new targets for therapy of digestive tract diseases.

描述(申请人提供)：我对了解正常发育和疾病机制之间的关系感兴趣。因此，作为一名研究生，我在分子生物学、生物化学和发育遗传学方面奠定了坚实的基础。作为博士后，我使用消化道作为模型系统，研究胚胎和成年小鼠干细胞更新和分化的基本发育问题。Noch信号在这些过程中起着关键作用。使用强大的小鼠遗传工具，我已经证明了Notch信号及其关键的下游肠道限制性转录因子Atoh1在肠道干细胞和祖细胞增殖、去分化和癌症中的作用，领先于4篇第一作者出版物。为了进一步了解上皮细胞中胃肠道细胞对Notch信号的反应机制，我现在的目标是研究Notch信号下游的转录因子。为了系统地鉴定在肠道细胞分化中发挥重要作用的新的转录因子并研究其潜在的转录机制，我将学习并应用染色质免疫沉淀结合高通量DNA测序的新的全基因组方法(CHIP-SEQ)。我将分析分泌转录因子Atoh1和TCF4在全基因组范围内的结合，并测试关于它们在细胞复制和TE肠道分泌细胞系分化中相互作用的特定机制假说。在不表达关键下游因子Atoh1的胃中，我将测试一个新的假设，即胃限制性同系物Ascl1作用于Notch信号的下游，调节上皮细胞的增殖和肠道内分泌分化。因此，我提出的研究将为胃肠道上皮细胞分化的中心机制提供新的和重要的见解，并有助于阐明分子 从先天性疾病、炎症到癌症等各种疾病的基础。我的目标是成为胃肠道生物学领域的独立首席研究员，拥有谱系分化方面的专业知识。K99/R00奖将促进我通过连续的指导阶段和独立阶段过渡到完全独立。在短期内，这个奖项将让我在Ramesh Shivdasani的指导下学习包括芯片序列和生物信息学分析在内的新技术，从而扩大我的专业知识，包括系统生物学和基因组学知识。他的实验室成功地完成了应用这种方法的项目并发表了重要论文，提供了一个完美的培训环境。此外，达纳-法伯癌症研究所和哈佛医学院特殊的机构环境将进一步使我能够通过提供机构项目、设施、合作机会和广泛的导师来过渡到独立。我的导师委员会包括胃肠道生物学、转录和基因组学领域的世界领先的哈佛大学教师，为我发展自己的研究项目提供指导和支持。此外，哈佛干细胞研究所和达纳-法伯癌症研究所的功能性癌症表观遗传学中心(CFCE)不仅将为我提供完善方法的绝佳机会，还将使我能够与干细胞生物学和表观基因组学领域的知名科学家互动和合作。因此，K99/R00奖将在我职业生涯的关键阶段提供关键支持，并使我能够长期致力于研究胃肠道疾病背后的独特生物学。在长期的未来，作为一名成功的独立研究员，我将致力于了解胃肠道疾病的基本机制，领导与临床和计算生物学家的合作努力，并培养下一代基础和临床科学家。 与公共健康相关：胃肠道表面通过胃和肠道干细胞的活动不断得到补充，这些干细胞分化为专门的细胞类型。尽管这些细胞有罹患癌症和炎症等疾病的风险，但对其分子调控的了解尚不完全。这项K99/R00奖的建议侧重于重要的器官特异性转录因子，即控制数百个其他基因的蛋白质，我建议研究这些蛋白质如何在一种名为Notch的重要发育信号通路中发挥作用。这些研究将有助于确定胃肠道细胞分化的分子机制，并为消化系统疾病的治疗寻找新的靶点。