The Role of ARNT in Endothelial Cells

ARNT 在内皮细胞中的作用

• 批准号: 8040730
• 负责人: DIANA L RAMIREZ-BERGERON
• 金额: $ 40.14万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8040730
• 关键词: ARNT gene; Address; Adult; Affect; Anatomy; Behavior; Biological; Blood Vessels; Cardiovascular system; Cell Hypoxia; Cell Proliferation; Cell Survival; Cells; Chemotaxis; Clinical; Data; Defect; Dependency; Development; Disease; Embryo; Embryonic Development; Endothelial Cells; Endothelium; Environment; Experimental Designs; Gene Expression; Generations; Genes; Genetic; Genetic Programming; Genetic Transcription; Growth; Hematopoietic; Homeostasis; Human; Hypoxia; Hypoxia Inducible Factor; Hypoxia-Inducible Factor Pathway; Impairment; Injury; Investigation; Ischemia; Laboratories; Lead; Maintenance; Mediating; Molecular; Mus; Myocardium; Nutrient; Oxygen; Pathology; Pathway interactions; Phenotype; Physiological; Play; Pre-Eclampsia; Process; Production; Regulation; Research; Role; Signal Transduction; Staging; Stimulus; System; Testing; Therapeutic Agents; Tissues; Vascular Diseases; Vascular Endothelial Cell; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factors; Vascular remodeling; Work; Wound Healing; angiogenesis; bHLH-PAS factor HLF; embryo tissue; human ARNT protein; hypoxia inducible factor 1; in vivo; innovation; insight; loss of function; migration; programs; response; sensor; skeletal; tissue regeneration; transcription factor; tumor; tumorigenesis; vasculogenesis

DESCRIPTION (provided by applicant): Hypoxia Inducible Factor (HIF) is a critical sensor of tissue O2 levels and governs angiogenic gene expression programs operating during embryogenesis as well as in post-natal pathologies including wound healing and ischemia. In principle, HIF contributes to important genetic programs responsible for moderating and controlling vascular growth. Mice deficient in HIF display developmental arrest due to multiple cardiovascular anomalies. However, the significance of a specific role for the HIF-canonical pathway in vascular endothelial cells (ECs) is lacking. The long-term research objective of this application is to determine how HIF, in response to the hypoxic (low oxygen) environment, regulates vascular growth necessary for maintaining tissue homeostasis. It has been demonstrated the specific activity of HIF is cell- and context- dependent. This proposal addresses the general hypothesis that EC- HIF activates distinct genes regulating specific types of vessel growth at various stages of vascular development and in post-natal angiogenesis. We will further determine whether HIF, in response to hypoxia, moderates the temporal expression of VEGF receptors that are important in mediating specific signals in ECs including their survival, proliferation, and behavior. The experimental design utilizes an Arnt-conditional (HIF-2 obligatory subunit in vessels) mouse genetic system that completely inactivates HIF-transcriptional activity in ECs at various stages of embryonic development as well as in the adult vasculature enabling the investigations of HIF's requirement(s) and role(s) within ECs during the establishment, maturation, and maintenance of blood vessels as well as in response to vascular injury. Specific Aim 1 will examine how HIF inactivation in ECs at critical stages of embryonic development lead to specific angiogenic defects. Aim 2 addresses the requirement(s) for HIF in adult vessel homeostasis and various types of vascular responses (neoangiogenesis, angiogenesis, and arteriogenesis). Finally, Aim 3 will examine the intrinsic requirements of HIF within ECs and test the hypothesis that HIF is important in promoting EC survival in part by regulating the expression of VEGF receptors. The studies proposed herein intend to expand our understanding of the mechanisms by which hypoxia regulates vessel generation and homeostasis in both normal and pathological settings. PUBLIC HEALTH RELEVANCE: Defective vessel development and/or maintenance is a feature of multiple human pathological vascular diseases including tumorigenesis and tissue ischemia. By using in vivo genetic approaches, we can methodically investigate the biological and molecular vascular processes driven by endothelial HIF transcriptional responses. This work will provide a molecular framework aimed at understanding the biological significance of HIF activity in endothelial cells during physiological and pathological vascular responses observed in embryos and adults. Such investigation is of clinical importance since it can provide new directions for the development of therapeutic agents targeting vascular growth processes.

描述（由申请人提供）：缺氧诱导因子 (HIF) 是组织 O2 水平的关键传感器，控制着胚胎发生期间以及产后病理（包括伤口愈合和缺血）中运行的血管生成基因表达程序。原则上，HIF 有助于调节和控制血管生长的重要遗传程序。缺乏 HIF 的小鼠由于多种心血管异常而表现出发育停滞。然而，HIF 经典通路在血管内皮细胞 (EC) 中的特定作用的意义尚不明确。该应用的长期研究目标是确定 HIF 如何响应缺氧（低氧）环境，调节维持组织稳态所需的血管生长。已经证明 HIF 的比活性是细胞和环境依赖性的。该提案提出了一个普遍的假设，即 EC-HIF 在血管发育的各个阶段和出生后血管生成中激活调节特定类型血管生长的不同基因。我们将进一步确定 HIF 是否会响应缺氧而调节 VEGF 受体的时间表达，而 VEGF 受体对于介导 EC 中的特定信号（包括其生存、增殖和行为）非常重要。实验设计利用 Arnt 条件性（血管中 HIF-2 必需亚基）小鼠遗传系统，该系统可完全灭活胚胎发育各个阶段以及成人脉管系统中 EC 中的 HIF 转录活性，从而能够研究在血管建立、成熟和维持以及对血管损伤的反应过程中 HIF 在 EC 中的需求和作用。具体目标 1 将研究胚胎发育关键阶段 EC 中 HIF 失活如何导致特定的血管生成缺陷。目标 2 解决了成人血管稳态和各种类型血管反应（新血管生成、血管生成和动脉生成）中 HIF 的要求。最后，目标 3 将检查 EC 内 HIF 的内在需求，并检验 HIF 在部分通过调节 VEGF 受体的表达来促进 EC 存活方面发挥重要作用的假设。本文提出的研究旨在扩大我们对正常和病理环境下缺氧调节血管生成和稳态的机制的理解。 公众健康相关性：血管发育和/或维护缺陷是多种人类病理性血管疾病（包括肿瘤发生和组织缺血）的一个特征。通过使用体内遗传方法，我们可以系统地研究由内皮 HIF 转录反应驱动的生物和分子血管过程。这项工作将提供一个分子框架，旨在了解在胚胎和成人中观察到的生理和病理血管反应期间内皮细胞中 HIF 活性的生物学意义。这种研究具有临床重要性，因为它可以为开发针对血管生长过程的治疗剂提供新的方向。