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: 8391135
• 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/8391135
• 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; public health relevance; 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.

描述（由申请人提供）： 红细胞生成素（Epo）是红细胞生成的主要调节剂，因为它控制红系祖细胞的存活、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贫血以及其他类型的贫血。然而，已经报道了EPO在非红细胞组织中的不同临床作用，并且在脑、内皮、造血干细胞、乳腺、卵巢、睾丸和其他组织中发现了EPO和/或其受体（EPOR）基因的转录物。报道的Epo的有益作用包括其在中风患者的缺血性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施用也可能是有害的。据报道，在几项临床研究中，由HIF-1和/或HIF-2调节的Epo和EpoR的水平与癌症患者的存活率降低和癌症侵袭性增加相关，并且在癌症患者中Epo治疗的一些临床研究表明Epo施用可能是有害的。此外，在一些正常组织以及许多癌症中发现了EPO和EPOR转录物。由于Epo或EpoR缺失小鼠的胚胎致死性和缺乏适当的动物模型，非红系细胞中Epo功能的研究受到限制。以前，我们产生了两个可行的敲入小鼠模型，减少Epo信号（这些小鼠贫血）和增强Epo信号（这些小鼠红细胞增多症）。这些小鼠是研究Epo在非红系组织中功能的基础。我们已经产生了红细胞特异性Cre表达小鼠。这些小鼠将用于恢复仅在血液中的Epo信号，从而拯救转基因小鼠免于贫血。通过与脑特异性cre小鼠杂交，这些小鼠将用于在脑等感兴趣组织中产生功能获得性EpoR小鼠。缺氧诱导因子（HIF）是由缺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1-亚基（3种同种型; HIF-11、HIF-21、HIF-31）和共同的b-亚基组成的异二聚体。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控，但在某些情况下，它们的基因调控是组织特异性和基因特异性的。HIF调控的分子基础正在深入研究中。虽然Epo是第一个被鉴定的具有用于HIF结合的定义的寡核苷酸序列的基因，其被指定为缺氧反应元件（HRE），但EpoR基因不具有保守的HRE。我们已经研究了HIF调节Epo转录的机制，使用染色质免疫沉淀（ChIP），并发现了多个HRE的Epo基因。我们的数据表明，这些HRE差异利用HIF- 1和HIF-2在组织特异性的方式。基于这一证据，我们建议使用我们机构购买的全基因组Chip-Seq仪器在低氧和常氧条件下研究选定组织中的HRE。对兽医保健的影响：老年退伍军人，以及新返回的退伍军人从波斯湾地区，患有认知，血管和恶性疾病。从该项目获得的数据将用于表征在一些人类恶性肿瘤中报告的增强的Epo/EpoR信号传导，并且可以作为潜在的治疗癌症靶点，而在其他情况下（即，中风），在所选组织中Epo/EpoR的治疗性增强可能是有益的。我们正在进行的和未来计划的研究应该阐明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。