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: 7796916
• 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/7796916
• 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; 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

DESCRIPTION (provided by applicant): 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 1- subunit (3 isotypes; HIF-11, HIF-21, HIF-31) and a common b-subunit. HIF-11 and HIF-21 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. PUBLIC HEALTH RELEVANCE: Project Narrative/Relevance to Veterans Health The VA population consists, in part, of patients with cardiovascular and cerebrovascular diseases. Elderly populations, such as those in the VA, as well as current returning veterans from Iraq and Afghanistan are also at high risk for traumatic brain injury. The possibility that Epo may play a beneficial as well as detrimental role in endothelial/cardiovascular, neurological abnormalities, and cancers is relevant to a significant portion of VA patients.

描述(由申请人提供)： 项目摘要/摘要促红细胞生成素(EPO)是红细胞生成的主要调节因子，因为它控制着红系祖细胞的存活、增殖和分化。重组人促红细胞生成素已被广泛用于纠正肾功能衰竭的贫血和其他类型的贫血。然而，EPO在非红系组织中的临床作用有多种报道，在脑、内皮、造血干细胞、乳腺、卵巢、睾丸等组织中发现了EPO和/或其受体(EPOR)基因的转录本。已报道的EPO的有益作用包括在中风患者的缺氧性脑中观察到的低氧应激的神经保护作用，而其他研究表明，EPO的应用也可能是有害的。一些临床研究表明，受HIF-1和/或HIF-2调控的EPO和EPOR水平与癌症患者的生存率降低和肿瘤侵袭性增加有关，一些临床研究表明EPO治疗癌症患者可能是有害的。此外，在一些正常组织和许多癌症中也发现了EPO和EPOR转录本。由于EPO或EPOR基因缺失小鼠的胚胎致死性，以及缺乏合适的动物模型，有关EPO在非红系细胞中的作用的研究一直受到限制。在此之前，我们建立了两种可行的敲入小鼠模型，一种是EPO信号减少(这些小鼠贫血)，另一种是EPO信号增强(这些小鼠是红细胞增多症)。这些小鼠是研究EPO在非红系组织中功能的基础。我们已经产生了表达红系特异性Cre的小鼠。这些小鼠将仅用于恢复血液中的EPO信号，从而将转基因小鼠从贫血中拯救出来。这些小鼠将通过与大脑特有的cre小鼠杂交，在大脑等感兴趣的组织中产生功能增强的EPOR小鼠。低氧诱导因子(HIF)是低氧诱导的关键转录因子(从EPO基因调控研究中发现)，在癌症中升高。HIF是由一个1-亚基(3个亚型：HIF-11、HIF-21、HIF-31)和一个共同的b-亚基组成的杂二聚体。HIF-11和HIF-21具有显著的同源性，虽然它们可能共享它们的一些靶基因的调节，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调控的分子基础正在深入研究中。EPO基因是第一个确定了与HIF结合的寡核苷酸序列的基因，被命名为缺氧反应元件(HRE)，而EPOR基因没有保守的HRE。我们用染色质免疫沉淀(ChIP)研究了HIF对EPO转录的调控机制，发现了EPO基因的多个HRE。我们的数据表明，这些HRE被HIF-1和HIF-2以组织特异性的方式差异地利用。基于这一证据，我们建议使用本研究所购买的全基因组芯片序列仪器来研究低氧和常氧条件下选定组织中的HRE。对退伍军人医疗保健的影响：来自波斯湾地区的老年退伍军人以及新归来的退伍军人患有认知、血管和恶性疾病。从这个项目中获得的数据将被用来表征在一些人类恶性肿瘤中报告的增强的EPO/EPOR信号，并可能作为潜在的治疗癌症的靶点，而在其他情况下(如中风)，在选定的组织中对EPO/EPOR进行治疗增强可能是有益的。我们正在进行的和未来计划中的研究应该阐明EPO对动脉粥样硬化、高血压、认知功能和预防缺血诱导的组织损伤的影响。 公共卫生相关性： 项目简介/与退伍军人健康的相关性退伍军人群体部分由心脑血管疾病患者组成。老年人口，如退伍军人，以及目前从伊拉克和阿富汗归来的退伍军人，也是创伤性脑损伤的高危人群。促红细胞生成素可能在血管内皮细胞/心血管、神经异常和癌症中发挥有益和有害的作用，这一可能性与相当一部分VA患者有关。