Genetic Control of Intestinal Epithelial Stem Cell Maintenance & Differentiation

肠上皮干细胞维持的遗传控制

• 批准号: 8913314
• 负责人: SCOTT T MAGNESS
• 金额: $ 6.36万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-21 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8913314
• 关键词: Ablation; Adult; Biological Assay; Biological Markers; Boxing; Cell Adhesion; Cell Adhesion Molecules; Cell Differentiation process; Cell Line; Cell Lineage; Cell Maintenance; Cell Proliferation; Cell-Cell Adhesion; Cells; Characteristics; Chromatin; Coculture Techniques; Colon; Communication; Competence; Critical Pathways; DNA; Data; Data Set; Defect; Disease; Embryonic Development; Enteroendocrine Cell; Epithelial; Family; Gene Targeting; Genes; Genetic; Genomics; Goblet Cells; Grant; High-Throughput Nucleotide Sequencing; In Vitro; Intestinal Diseases; Intestines; Knowledge; Lead; Link; Mediator of activation protein; Modeling; Molecular; Molecular Biology Techniques; Mono-S; Mus; Natural regeneration; Nurses; Paneth Cells; Paracrine Communication; Pathway interactions; Phenotype; Physiological; Play; Process; RNA; Regulation; Regulator Genes; Regulatory Pathway; Research; Role; Signal Transduction; Small Intestines; Stem cells; Tamoxifen; Testing; Time; Tissues; base; cell behavior; cell motility; field study; functional loss; in vivo; insight; intestinal epithelium; intestinal homeostasis; member; mouse model; mutant; next generation; novel; paracrine; progenitor; recombinase; self-renewal; stem cell biology; stem cell niche; stemness; transcription factor

DESCRIPTION (provided by applicant): The intestinal epithelium is constantly renewed by a pool of multipotent intestinal epithelial stem cells (IESCs) located at the crypt base. IESCs are defined by their a) competence to self-renew, and b) multipotency to give rise to all terminally differentiated intestinal epithelial lineages - characteristics otherwise known as 'stemness'. A major question in IESC biology is what controls stemness. Members of the Sox (Sry Box) family of transcription factors function as master control switches for stemness in other tissues. This proposal aims to define the specific roles and gene targets of Sox9 in IESC stemness. We recently demonstrated that distinct levels of Sox9 differentially mark functional IESCs, progenitors, enteroendocrine cells and Paneth cells. Sox9 and Lgr5 both mark IESCs that are intercalated between and make intimate contact with Paneth cells. New evidence suggests that Paneth cells serve as 'nurse' cells and are critical for IESC maintenance. Ablation of Sox9 in intestinal epithelium during embryogenesis results in the loss of Paneth cells and increased proliferation within the crypts of the small intestine and colon. Our new preliminary data on short-term effects of inducible Sox9 ablation in the adult intestinal epithelium confirm crypt hyperproliferation, but also provide novel evidence for additional phenotypic consequences including expansion and displacement of Paneth cels, morphological defects in Paneth cells, mis-expression of goblet biomarker Muc2 in Paneth cells, reductions in crypt-based enteroendocrine cells and goblet cells, and loss of epithelial mono-layer characteristics. Gene microarray on normal small intestine versus intestine from inducible conditional Sox9-mutants indicates that Sox9 controls genes and pathways involved in proliferation, cell adhesion and migration. Since our preliminary studies ablated Sox9 in a pan-epithelial manner, they do not distinguish which phenotypic effects result from the loss of Sox9 in the IESC versus other Sox9-expressing cell lineages, including Paneth cells. The central hypothesis is that Sox9 normally limits IESC proliferation and preserves multipotency by a) intrinsic regulation of specific target genes within IESCs, and b) regulation of Paneth cell specific genes that extrinsically control IESC proliferation or potency by paracrine influences or by restricting Paneth cells to the IESC niche. To test this hypothesis we propose the following aims: 1) to determine the specific roles of Sox9 in IESCs, 2) to determine how Sox9 regulated genes in Paneth cells impacts IESC stemness, 3) to identify specific gene targets and networks regulated by Sox9 in a) IESCs and b) Paneth cells. Successful completion of these studies will lead to novel findings including intrinsic and extrinsic mechanisms controlling IESC behavior. These findings will likely extend to parallel fields of study related to other tissue specific stem cells.

描述（由申请人提供）：肠上皮不断地被位于隐窝碱基的多元肠上皮干细胞（IESC）池恢复。 IESC由它们的a）自我更新的能力定义，b）产生所有终端分化的肠上皮谱系的多能力 - 特征 - 否则称为“ stemness”。 IESC生物学中的一个主要问题是控制茎。 Sox（Sry Box）转录因子家族的成员充当其他组织中干性的主控制开关。该建议旨在定义SOX9在IESC茎中的特定作用和基因靶标。我们最近证明，不同水平的SOX9差异标记了功能性IESC，祖细胞，肠内分泌细胞和泛细胞。 Sox9和lgr5两个标记IESC在与Paneth细胞之间进行了插入并保持亲密接触。新的证据表明，Paneth细胞是“护士”细胞，对于IESC维持至关重要。胚胎发生过程中肠道上皮中Sox9的消融导致泛细胞的丧失，并增加了小肠和结肠的隐窝内的增殖。 Our new preliminary data on short-term effects of inducible Sox9 ablation in the adult intestinal epithelium confirm crypt hyperproliferation, but also provide novel evidence for additional phenotypic consequences including expansion and displacement of Paneth cels, morphological defects in Paneth cells, mis-expression of goblet biomarker Muc2 in Paneth cells, reductions in crypt-based enteroendocrine cells and goblet cells, and上皮单层特征的丧失。基因微阵列在正常的小肠与诱导条件Sox9突变体的肠道上，表明SOX9控制着与增殖，细胞粘附和迁移有关的基因和途径。由于我们的初步研究以泛表的方式消除了Sox9，因此它们没有区分IESC中SOX9与包括Paneth细胞在内的其他表达SOX9细胞谱系的SOX9的丢失所致哪种表型效应。中心假设是SOX9通常会限制IESC的增殖，并通过a）通过IESC中的特定靶基因进行固有调节，b）b）调节Paneth细胞特异性基因，这些基因外在控制了IESC的IESC增殖或通过对旁分泌影响或通过对Paneth细胞对IESC Niche的PANETH细胞的限制。为了检验该假设，我们提出以下目的：1）确定SOX9在IESC中的特定作用，2）确定Sox9调节Paneth细胞中的基因如何影响IESC茎，3）识别由SOX9在A）IESC和B）Paneth细胞中识别由SOX9调节的特定基因靶标和网络。这些研究的成功完成将导致新发现，包括控制IESC行为的固有和外部机制。这些发现可能会扩展到与其他特定组织干细胞有关的研究领域。