Fox Transcription Factors in Development of Pulmonary Capillaries

肺毛细血管发育中的 Fox 转录因子

• 批准号: 7079705
• 负责人: Vladimir Kalinichenko
• 金额: $ 38.25万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7079705
• 关键词: biological signal transduction; capillary; cell differentiation; cell proliferation; developmental genetics; embryogenesis; gene expression; genetic transcription; genetically modified animals; laboratory mouse; lung; lung development; mesoderm; respiratory function; tissue /cell culture; transcription factor; vascular endothelium

DESCRIPTION (provided by applicant): Forkhead Box (Fox) transcription factors Foxml and Foxfl are expressed in developing pulmonary endothelial cells and play an essential role in lung development. Deficiency of either one of these Fox genes is associated with severe defects in formation of peripheral pulmonary capillaries as well as abnormalities in many organs causing embryonic lethality. Our hypothesis is that Foxml and Foxfl regulate transcription of genes critical for proliferation and differentiation of endothelial cells during pulmonary vascular development. In order to test this hypothesis, we will use the Tie2 promoter driven Tamoxifen-inducible Cre recombinase (Tie2-Cre-ERT2) transgene to mediate developmental-stage-specific deletion of either Foxfl or Foxml LoxP/LoxP (fl/fl) targeted allele in endothelial cells. In Aim 1, we describe plans to use Tie2-Cre-ERT2 Foxml fl/fl embryonic lungs and cultured pulmonary endothelial cells derived from these embryos to determine whether Foxml is required for endothelial cell proliferation and differentiation during lung vascular development. In Aim 2, we will develop a mouse containing a Foxfl fl/fl targeted allele and use the Tie2-Cre- ERT2 transgene to mediate temporal endothelial-specific deletion of the Foxfl fl/fl at different stages of lung development. We will use Tie2-Cre-ERT2 Foxfl fl/fl mice to determine whether Foxfl directly regulates endothelial cell differentiation and identify a time period during which Foxfl function is required to elicit proper vascular lung development and to regulate Foxfl target genes. We have shown that Foxfl regulates expression of genes involved in Notch-2 signaling and that the Notch-2 pathway is critical for normal development of lung microvasculature. In Aim 3, we propose to generate mice with the endothelial-specific Tie-2 promoter driven Notch-2 transgene. These Tie-2 Notch-2 mice will be bred with Foxfl mice to determine whether increased Notch-2 receptor levels in embryonic Foxfl lung will restore normalcy to the development of alveolar microvasculature and prevent perinatal pulmonary hemorrhage in Foxfl newborn mice. Completion of the proposed studies will enable us to determine the role of Foxfl and Foxml proteins in endothelial cells during lung development. These Fox proteins may also provide novel targets in genetic screening, diagnosis and treatment of human pediatric lung diseases including perinatal pulmonary hemorrhage and respiratory distress syndrome of premature born babies.

描述（由申请人提供）： Forkhead Box（Fox）转录因子Foxml和Foxfl在发育中的肺内皮细胞中表达并在肺发育中发挥重要作用。这些 Fox 基因中任何一个的缺陷都与周围肺毛细血管形成的严重缺陷以及导致胚胎致死的许多器官的异常有关。我们的假设是 Foxml 和 Foxfl 调节对肺血管发育过程中内皮细胞增殖和分化至关重要的基因的转录。为了检验这一假设，我们将使用 Tie2 启动子驱动的他莫昔芬诱导型 Cre 重组酶 (Tie2-Cre-ERT2) 转基因来介导 Foxfl 或 Foxml LoxP/LoxP (fl/fl) 目标等位基因的发育阶段特异性删除在内皮细胞中。在目标 1 中，我们描述了使用 Tie2-Cre-ERT2 Foxml fl/fl 胚胎肺和源自这些胚胎的培养肺内皮细胞的计划，以确定 Foxml 是否是肺血管发育过程中内皮细胞增殖和分化所必需的。在目标 2 中，我们将培育一只含有 Foxfl fl/fl 靶向等位基因的小鼠，并使用 Tie2-Cre-ERT2 转基因在肺发育的不同阶段介导 Foxfl fl/fl 的颞内皮特异性缺失。我们将使用 Tie2-Cre-ERT2 Foxfl fl/fl 小鼠来确定 Foxfl 是否直接调节内皮细胞分化，并确定需要 Foxfl 功能来引发适当的血管肺发育和调节 Foxfl 靶基因的时间段。我们已经证明 Foxfl 调节参与 Notch-2 信号传导的基因的表达，并且 Notch-2 途径对于肺微血管系统的正常发育至关重要。在目标 3 中，我们建议生成具有内皮特异性 Tie-2 启动子驱动的 Notch-2 转基因的小鼠。这些Tie-2 Notch-2小鼠将与Foxfl小鼠一起饲养，以确定胚胎Foxfl肺中Notch-2受体水平的增加是否会恢复肺泡微血管发育的正常状态并预防Foxfl新生小鼠的围产期肺出血。完成拟议的研究将使我们能够确定 Foxfl 和 Foxml 蛋白在肺发育过程中内皮细胞中的作用。这些Fox蛋白还可能为人类小儿肺部疾病（包括围产期肺出血和早产儿呼吸窘迫综合征）的基因筛查、诊断和治疗提供新靶点。