Progenitor Cells in Lung Development and Repair

肺发育和修复中的祖细胞

• 批准号: 7456820
• 负责人: BRIGID L.M. HOGAN
• 金额: $ 39万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-05 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7456820
• 关键词: Address; Adult; Alleles; Alveolar Cell; Basal Cell; Biological Assay; Biological Models; Birth; Cell Separation; Cell physiology; Cells; Chromosome Mapping; Clara cell; Condition; Daughter; Defect; Development; Distal; Embryo; Embryonic Development; Epithelial; Epithelial Cells; Epithelium; Exposure to; Flow Cytometry; Functional RNA; Gene Expression; Gene Expression Profile; Genes; Genetic; Genetic Models; Genetic Recombination; Genetically Engineered Mouse; Homeostasis; Human; Individual; Injury; Lead; Link; Lung; Main Bronchus; Maintenance; MicroRNAs; Molecular; Multipotent Stem Cells; Mus; Naphthalene; Naphthalenes; Numbers; Organism; Pathway interactions; Physiologic pulse; Population; Protein Overexpression; Pseudostratified Epithelium; Pulse taking; Regulator Genes; Relative (related person); Risk; Role; Small RNA; Stem cells; Sulfur Dioxide; System; Tamoxifen; Testing; Therapeutic; Time; Trachea; Transgenic Organisms; Work; aptamer; direct application; genetic manipulation; improved; in vivo; loss of function; lung development; member; progenitor; repaired; research study; self-renewal; time use; tool; transcription factor

DESCRIPTION (provided by applicant): Relatively little is known about the molecular pathways defining the epithelial progenitor cells of the embryonic and adult lung and their role in lung development, steady state homeostasis and repair after damage caused by environmental and other agents. In this competitive renewal we will build on previous discoveries to obtain new information about basic mechanisms controlling the specification, proliferation, and differentiation of lung epithelial progenitor/stem cells, using the mouse as a model genetic organism. In Aim 1 we will test the hypothesis that the developmental potential of epithelial progenitor cells in the distal tips of the embryonic lung changes in an orderly way over time so that early born descendants give rise to cells in the proximal airways while late born daughters give rise to alveolar cells. For this aim we have already generated two new lines of genetically engineered mice, Id2-GFP and Id2-CreER. These will enable us to follow the developmental fate of distal tip cells in vivo, isolate the cells at different times using flow cytometry, analyze their transcriptome using gene arrays, and test the role of candidate regulatory genes using gain and loss of function experiments. In Aim 2 we will focus on the adult trachea and main bronchi which has a pseudostratified epithelium, as in a large proportion of the human airways. We will test the relative contribution of basal stem cells and secretory (Clara) cells in maintaining this region and in repairing it after injury by exposure to naphthalene or sulfur dioxide. This will be achieved using new K5-CreEr and Scgb1a1-CreEr alleles for fate mapping and gene manipulation. We will also elucidate basic mechanisms regulating the specification, self-renewal and differentiation of basal stem cells, focusing initially on the role of the transcription factor, Sox2. Finally, in a high risk Aim 3, we will test the hypothesis that small non-coding RNAs known as microRNAs can reversibly enhance the self-renewal potential of progenitor cells in the adult lung, either in the steady state or during repair. To do this we will initially inducibly express in basal and Clara cells the miR17-92 gene that encodes a conserved cluster of six microRNAs. We have already shown that this cluster enhances the proliferation of epithelial progenitors in the embryonic lung at the expense of their differentiation and we will now test this in adult progenitors. We will then test the activity of individual miR17-92 members or combinations of them. In the long term we will ask whether this activity can be obtained by direct application of double stranded small RNAs linked to cell-specific aptamers. PROJECT NARRATIVE. This work will increase our understanding of basic mechanisms regulating the embryonic development of the lung and the ability of the epithelial cells to undergo repair in the adult. In the long term the work may lead to potential therapies or predictive assays for pathological conditions related to defects in the supply, proliferation or differentiation of progenitor/stem cells in the human lung.

描述（由申请人提供）：关于定义胚胎和成人肺上皮祖细胞及其在肺发育中的作用，稳态稳态和修复后的分子途径，相对较少了解。在这种竞争性更新中，我们将建立以前的发现，以获取有关控制肺上皮祖细胞/干细胞的基本机制，使用小鼠作为模型遗传生物的基本机制。在AIM 1中，我们将测试以下假设：胚胎肺远端的上皮祖细胞的发育潜力随着时间的流逝而有序变化，以便早期出生的后代在近端气道中引起细胞，而后期出生的女儿则会引起肺泡细胞。为此，我们已经生成了两条新的基因工程小鼠，ID2-GFP和ID2-CREER。这些将使我们能够在体内遵循远端尖端细胞的发育命运，使用流式细胞仪在不同时间分离细胞，使用基因阵列分析其转录组，并使用功能实验的增益和丧失来测试候选调节基因的作用。在AIM 2中，我们将重点放在具有假上皮的成年气管和主支气管上，就像大部分人类呼吸道一样。我们将测试基底干细胞和分泌细胞（CLARA）细胞在维持该区域以及通过暴露于萘或二氧化硫损伤后修复的相对贡献。这将使用新的K5-Creer和SCGB1A1-CREER等位基因进行命运图和基因操纵来实现。我们还将阐明调节基础干细胞规范，自我更新和分化的基本机制，最初集中在转录因子SOX2的作用上。最后，在高风险目标3中，我们将检验以下假设：在稳态或修复过程中，小型非编码RNA被称为microRNA的小型无编码RNA可以可逆地增强成年肺中祖细胞的自我更新潜力。为此，我们最初将在基底和克拉拉细胞中表达MiR17-92基因，该基因编码了六个microRNA的保守簇。我们已经表明，该簇增强了胚胎肺中上皮祖细胞的增殖，但它们以分化为代价，现在我们将在成年祖细胞中进行测试。然后，我们将测试单个MiR17-92成员或它们组合的活性。从长远来看，我们将询问是否可以通过直接应用与细胞特异性适体相关的双链小RNA来获得此活动。项目叙述。这项工作将增加我们对调节肺部胚胎发育的基本机制以及上皮细胞在成年人进行修复的能力的理解。从长远来看，这项工作可能导致对与人类肺中祖细胞/干细胞的供应，增殖或分化相关的病理状况的潜在疗法或预测分析。