HIF-2alpha, hypoxic gene regulation, and angiogenesis

HIF-2α、缺氧基因调控和血管生成

基本信息

批准号：
7281657
负责人：
M. CELESTE SIMON
金额：
$ 33.81万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-03-15 至 2008-07-01
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7281657
关键词：
26S proteasome ARNT gene ARNT2 gene Address Adult Affinity Chromatography Alleles Anabolism Astrocytoma Binding Biochemical Genetics Biological Assay Blood Vessels Catecholamines Cell Culture System Cell Differentiation process Cells Code Complement Complementary DNA Complex Condition Conventional (Clear Cell) Renal Cell Carcinoma DNA Microarray Chip DNA Microarray format Development Disease Embryo Embryonic Development Endothelial Cells Engineering Exhibits Exons Fibrinogen Gene Expression Gene Expression Regulation Gene Targeting Genes Genetic Genetic Recombination Glycolysis Goals Growth Hematopoiesis Hematopoietic Homeostasis Hypoxia Hypoxia Inducible Factor Individual Knock-in Mouse Knock-out Malignant Epithelial Cell Malignant Neoplasms Mammalian Cell Mass Spectrum Analysis Mediating Microarray Analysis Mus Mutation Nature Neural Crest Cell Numbers Oxygen Pattern Peptides Phenotype Pheochromocytoma Physiology Play Proteins Renal Cell Carcinoma Reporting Role Stem cells Testing Tetanus Helper Peptide Tissues Vascular Endothelial Cell Vascular Endothelial Growth Factors Von Hippel-Lindau Syndrome Von Hippel-Lindau Tumor Suppressor Protein angiogenesis bHLH-PAS factor HLF embryonic stem cell gene induction homologous recombination in vivo interest mutant neoplastic neoplastic cell novel research study response tumor tumor growth tumor progression ubiquitin ligase

项目摘要

The ability of mammalian cells to respond to changes in available oxygen (O2) levels is essential to normal development and physiology. The hypoxia-inducible factors (HIFs) play a central role in these responses by activating the expression of genes involved in glycolysis, angiogenesis, and hematopoiesis, all of which contribute to hypoxic adaptation. HIFs are heterodimers consisting of alpha (HIF-1alpha or HIF-2alpha) subunits. Activation of HIF complexes depends on hypoxic stabilization of the highly related HIF-1alpha and HIF-2alpha subunits, which are degraded by the 26S proteasome under normoxic conditions. We have previously studied a role for ARNT and ARNT2 in angiogenesis and hematopoiesis. Given that elimination of ARNT blocks all HIF activity, the current proposal will elucidate the unique activities of HIF-1alpha and HIF-2alpha in development and disease and address several important questions: What target genes do HIF-1alpha and HIF-2alpha each regulate? Do HIF-1alpha and HIF-2alpha interact with different transcriptional co-activators or repressors? In what cells do both HIF-1alpha and HIF-2alpha function during development and in what cells do they function independently? What unique roles does HIF-2alpha play in adult physiology and disease? We hypothesize that HIF-2alpha regulates unique target genes that distinguish its activity from HIF-1alpha activity during both embryogenesis and tumor progression. To test this hypothesis, we will (1) investigate the unique and overlapping activities of HIF-2alpha and HIF-1alpha by analyzing their unique and/or common target genes, (2) identify the tissue-/cell- specific regulators of HIF-2alpha, (3) determine the degree of overlapping function between HIF-1alpha and HIF-2alpha in vivo using a genetic "knock-in" approach, and (4) use a conditional knock-out allele to assess specific functions of HIF-2alpha in adult mice. The function of HIF-2alpha has been considerably less well studied than that of HIF-1alpha. The proposed experiments are timely, as recent reports suggest that HIF-2alpha, but not HIF-1alpha, is critical to the progression of specific malignancies such as renal clear cell carcinoma, pheochromocytoma, and astrocytoma. The overall goal of our studies is to elucidate how HIF-1alpha and HIF-2alpha differentially regulate hypoxic gene induction and how this contributes to embryogenesis, angiogenesis, and neoplastic disease.

哺乳动物细胞对可用氧 (O2) 水平变化做出反应的能力对于正常发育和生理机能至关重要。缺氧诱导因子 (HIF) 通过激活参与糖酵解、血管生成和造血作用的基因表达，在这些反应中发挥核心作用，所有这些都有助于缺氧适应。 HIF 是由 α（HIF-1α 或 HIF-2α）亚基组成的异二聚体。 HIF 复合物的激活取决于高度相关的 HIF-1α 和 HIF-2α 亚基的缺氧稳定性，这些亚基在常氧条件下会被 26S 蛋白酶体降解。我们之前研究过 ARNT 和 ARNT2 在血管生成和造血中的作用。鉴于消除 ARNT 会阻断所有 HIF 活性，当前的提案将阐明 HIF-1α 和 HIF-2α 在发育和疾病中的独特活性，并解决几个重要问题：HIF-1α 和 HIF-2α 各自调节哪些靶基因？ HIF-1α 和 HIF-2α 是否与不同的转录共激活因子或阻遏因子相互作用？在发育过程中，HIF-1α 和 HIF-2α 在哪些细胞中同时发挥作用？它们在哪些细胞中独立发挥作用？ HIF-2α 在成人生理和疾病中发挥什么独特作用？我们假设 HIF-2α 调节独特的靶基因，在胚胎发生和肿瘤进展过程中将其活性与 HIF-1α 活性区分开来。为了检验这一假设，我们将 (1) 通过分析 HIF-2α 和 HIF-1α 独特和/或共同的靶基因来研究其独特且重叠的活性，(2) 识别 HIF-2 的组织/细胞特异性调节因子。 2alpha，(3) 使用遗传“敲入”方法确定体内 HIF-1alpha 和 HIF-2alpha 之间功能重叠的程度，以及 (4) 使用条件敲除等位基因评估 HIF-2alpha 的特定功能在成年小鼠中。与 HIF-1α 相比，对 HIF-2α 功能的研究要少得多。拟议的实验是及时的，因为最近的报告表明，HIF-2α（而不是 HIF-1α）对于特定恶性肿瘤（如肾透明细胞癌、嗜铬细胞瘤和星形细胞瘤）的进展至关重要。我们研究的总体目标是阐明 HIF-1α 和 HIF-2α 如何差异调节缺氧基因诱导，以及它如何促进胚胎发生、血管生成和肿瘤疾病。