Erythropoietin in Non-Erythroid Cells: Function and Regulation

非红细胞中的促红细胞生成素：功能和调节

• 批准号: 8195889
• 负责人: JOSEF T PRCHAL
• 金额: --
• 依托单位: VA SALT LAKE CITY HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8195889
• 关键词: Address; Afghanistan; Aging; Alleles; Anemia; Animal Model; Atherosclerosis; Binding; Bioinformatics; Biological Assay; Blood; Blood Circulation; Blood Vessels; Brain; Breast; Cancer Patient; Cardiovascular Diseases; Cardiovascular system; Cell physiology; Cells; Cerebrovascular Disorders; ChIP-seq; Clinical; Clinical Research; Cognitive; Congenital Disorders; Crossbreeding; Cytomegalovirus; Data; Disease; EPO gene; EPOR gene; Elderly; Elements; Embryo; Endothelium; Erythrocytes; Erythroid; Erythroid Cells; Erythropoietin; Exhibits; Foundations; Future; Gene Expression Regulation; Gene Targeting; Generations; Genes; Genetic Transcription; Genotype; Germ Cells; Goals; Grant Review; Health; Healthcare; Hematopoietic; Hematopoietic stem cells; Human; Hypertension; Hypoxia; Hypoxia Inducible Factor; Hypoxia-Responsive Elements; Individual; Inherited; Institutes; Institution; Institutional Review Boards; Intervention; Introns; Investigation; Iraq; Ischemia; Kidney Failure; Knock-in Mouse; Knockout Mice; Knowledge; Malignant - descriptor; Malignant Neoplasms; Membrane; Methods; Modeling; Molecular; Mus; Mutation; Nervous system structure; Neurologic; Normal tissue morphology; Oligonucleotides; Oocytes; Ovary; Pathology; Patients; Persian Gulf; Pharmacologic Substance; Play; Polycythemia; Population; Positioning Attribute; Prevention; Prevention strategy; Principal Investigator; Production; Protocols documentation; Receptor Gene; Regulation; Relative (related person); Renal carcinoma; Reporter; Reporting; Research; Role; Signal Transduction; Site; Specificity; Stress; Stroke; Technology; Testing; Testis; Therapeutic; Tissues; Transcript; Transgenic Mice; Traumatic Brain Injury; Universities; Utah; Variant; Veterans; abstracting; bHLH-PAS factor HLF; base; chromatin immunoprecipitation; clinical effect; clinically significant; cognitive function; erythroid differentiation; gain of function; genome-wide; high risk; hypoxia inducible factor 1; improved; instrument; interest; mouse model; novel; progenitor; programs; promoter; receptor; recombinant human erythropoietin; response; transcription factor

PROJECT SUMMARY/ABSTRACT Erythropoietin (Epo) is the principle regulator of red cell production, as it controls the survival, proliferation, and differentiation of erythroid progenitors. Recombinant human Epo has been widely used to correct the anemia of renal failure as well as other types of anemias. However, diverse clinical effects of Epo in nonerythroid tissues have been reported and transcripts of EPO and/or its receptor (EPOR) genes are found in brain, endothelium, hematopoietic stem cells, breast, ovary, testes, and other tissues. Reported beneficial effects of Epo include its neuroprotective role in hypoxic stress observed in the ischemic brains of stroke patients, while other studies demonstrated that Epo administration can also be detrimental. Levels of Epo and EpoR, regulated by HIF-1 and/or HIF-2, are reported to be associated with decreased survival of cancer patients and increased cancer aggressiveness in several clinical studies, and some clinical studies of Epo therapy in cancer patient suggested that Epo administration can be detrimental. Further, EPO and EPOR transcripts have been found in some normal tissues as well as in many cancers. Due to the embryonic lethality of Epo or EpoR null mice and the absence of a proper animal model, the study of Epo function in nonerythroid cells has been limited. Previously, we generated two viable knock-in mouse models with reduced Epo signaling (these mice are anemic) and with augmented Epo signaling (these mice are polycythemic). These mice are the foundation for studying Epo function in nonerythroid tissue. We have already generated erythroid-specific Cre-expressing mice. These mice will be used to restore Epo signaling only in blood, thus rescuing the transgenic mice from anemia. These mice will be used for the generation of a gain-of-function EpoR mouse in tissues of interest such as brain, by crossbreeding with brain-specific cre mice. Hypoxia-inducible factors (HIF) are the key transcription factors that are induced by hypoxia (discovered from studies of EPO gene regulation) and that are elevated in cancer. HIFs are heterodimers that consist of an ¿- subunit (3 isotypes; HIF-1¿, HIF-2¿, HIF-3¿) and a common b-subunit. HIF-1¿ and HIF-2¿ have significant homology, and while they may share regulation of some of their target genes, in some instances their gene regulation is tissue- and gene-specific. The molecular basis of HIF regulation is under intense investigation. While Epo was the first identified gene with a defined oligonucleotide sequence for HIF binding that was designated as Hypoxia Responsive Element (HRE), the EpoR gene does not have a conserved HRE. We have studied the mechanism of HIF regulation of Epo transcription using chromatin immunoprecipitation (ChIP) and have found multiple HREs of the Epo gene. Our data suggest that these HREs are differentially utilized by HIF- 1 and HIF-2 in a tissue-specific manner. Based on this evidence, we propose to study HRE in selected tissues under hypoxic and normoxic conditions using a genome-wide Chip-Seq instrument purchased by our institution. IMPACT ON VETERANS HEALTHCARE: Aging veterans, as well as newly returning veterans from Persian Gulf region, suffer from cognitive, vascular, and malignant disorders. The data obtained from this project will be used to characterize augmented Epo/EpoR signaling reported in some human malignancies and may serve as potential therapeutic cancer targets, while in other situations (i.e., strokes) the therapeutic augmentation of Epo/EpoR in selected tissues may be beneficial. Our ongoing and future planned studies should clarify the effect of Epo on atherosclerosis, hypertension, cognitive function, and prevention of ischemia-induced tissue damage.

项目概要/摘要 促红细胞生成素 (Epo) 是红细胞生成的主要调节因子，因为它控制着生存、增殖、 和红系祖细胞的分化。重组人Epo已被广泛用于纠正 肾衰竭贫血以及其他类型的贫血。然而，Epo 的临床效果多种多样。 据报道，非红细胞组织中发现了 EPO 和/或其受体 (EPOR) 基因的转录本 脑、内皮、造血干细胞、乳腺、卵巢、睾丸和其他组织。报告的有益效果 Epo 的作用包括在中风患者缺血性大脑中观察到的缺氧应激中的神经保护作用， 而其他研究表明，EPO 给药也可能有害。 Epo 和 EpoR 水平， 受 HIF-1 和/或 HIF-2 调节，据报道与癌症患者的生存率降低有关 多项临床研究显示癌症侵袭性增加，以及 Epo 治疗癌症的一些临床研究 患者认为 Epo 给药可能有害。此外，EPO 和 EPOR 转录本已 存在于一些正常组织以及许多癌症中。由于 Epo 或 EpoR null 的胚胎致死性 小鼠和缺乏适当的动物模型，非红系细胞中 Epo 功能的研究一直是 有限的。此前，我们生成了两种 Epo 信号减弱的可行敲入小鼠模型（这些小鼠 贫血）和 Epo 信号增强（这些小鼠是红细胞增多症）。这些老鼠是基础 用于研究非红细胞组织中的 Epo 功能。我们已经生成了红细胞特异性 Cre 表达 老鼠。这些小鼠将仅用于恢复血液中的 Epo 信号传导，从而将转基因小鼠从 贫血。这些小鼠将用于在感兴趣的组织中产生功能获得性 EpoR 小鼠，例如 作为大脑，通过与大脑特异性的 cre 小鼠杂交。 缺氧诱导因子（HIF）是缺氧诱导的关键转录因子（发现于 EPO 基因调控的研究）并且在癌症中升高。 HIF 是由 ¿- 组成的异二聚体 亚基（3 个同种型；HIF-1¿、HIF-2¿、HIF-3¿）和一个常见的 b 亚基。 HIF-1¿ 和 HIF-2¿ 具有显着的 同源性，虽然它们可能共享某些靶基因的调控，但在某些情况下它们的基因 调节是组织和基因特异性的。 HIF 调节的分子基础正在深入研究中。 虽然 Epo 是第一个被鉴定具有用于 HIF 结合的确定寡核苷酸序列的基因， EpoR 基因被称为缺氧反应元件 (HRE)，没有保守的 HRE。我们有 使用染色质免疫沉淀 (ChIP) 研究 HIF 调节 Epo 转录的机制 发现了 Epo 基因的多个 HRE。我们的数据表明，这些 HRE 被 HIF 不同地利用 1 和 HIF-2 以组织特异性方式。基于这一证据，我们建议研究选定组织中的 HRE 使用我们机构购买的全基因组芯片测序仪器在低氧和常氧条件下进行。 对退伍军人医疗保健的影响：老龄化退伍军人以及刚从波斯回归的退伍军人 海湾地区患有认知、血管和恶性疾病。从该项目获得的数据将 可用于表征某些人类恶性肿瘤中报告的增强的 Epo/EpoR 信号传导，并可作为 潜在的癌症治疗目标，而在其他情况下（即中风），治疗增强 Epo/EpoR 在某些组织中可能是有益的。我们正在进行的和未来计划的研究应该澄清 Epo 对动脉粥样硬化、高血压、认知功能和预防组织缺血的影响 损害。