Understanding and Improving Iron Distribution and Erythropoiesis in Beta-Thalasse

了解和改善 Beta-Thalasse 中的铁分布和红细胞生成

• 批准号: 8030271
• 负责人: Yelena Ginzburg
• 金额: $ 13.23万
• 依托单位: NEW YORK BLOOD CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-15 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8030271
• 关键词: Address; Affect; Anemia; Apoptosis; Award; Binding; Blood Circulation; Bone Marrow; Cell Survival; Cell physiology; Cells; Clinical; Cytosol; Data; Deposition; Development; Disease; Equilibrium; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Erythropoietin; Evaluation; Extramedullary; Foundations; Functional disorder; Generations; Genetic Transcription; Globin; Goals; Hematopoietic; Heme; Heme Iron; Hemoglobin; Human; Human Cell Line; In Transferrin; In Vitro; Intestines; Iron; Iron Overload; K-562; Laboratories; Measures; Medicine; Mentors; Methods; Morbidity - disease rate; Mus; Patients; Phenotype; Physiology; Play; Principal Investigator; Production; Recycling; Regulation; Relative (related person); Reticulocytosis; Role; Sampling; Scientist; Serum; Spleen; Splenomegaly; Staging; Testing; Thalassemia; Therapeutic; Toxic effect; Training Programs; Transferrin; Transferrin Receptor; Transfusion; Translations; absorption; alpha Globin; alternative treatment; beta Globin; beta Thalassemia; career; chelation; diferric transferrin; disease phenotype; erythroid differentiation; heme 1; hepcidin; human TFRC protein; human disease; improved; in vivo; insight; iron metabolism; mortality; pre-clinical; programs; therapeutic development; uptake; zinc protoporphyrin; Address; Affect; Anemia; Apoptosis; Award; Binding; Blood Circulation; Bone Marrow; Cell Survival; Cell physiology; Cells; Clinical; Cytosol; Data; Deposition; Development; Disease; Equilibrium; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Erythropoietin; Evaluation; Extramedullary; Foundations; Functional disorder; Generations; Genetic Transcription; Globin; Goals; Hematopoietic; Heme; Heme Iron; Hemoglobin; Human; Human Cell Line; In Transferrin; In Vitro; Intestines; Iron; Iron Overload; K-562; Laboratories; Measures; Medicine; Mentors; Methods; Morbidity - disease rate; Mus; Patients; Phenotype; Physiology; Play; Principal Investigator; Production; Recycling; Regulation; Relative (related person); Reticulocytosis; Role; Sampling; Scientist; Serum; Spleen; Splenomegaly; Staging; Testing; Thalassemia; Therapeutic; Toxic effect; Training Programs; Transferrin; Transferrin Receptor; Transfusion; Translations; absorption; alpha Globin; alternative treatment; beta Globin; beta Thalassemia; career; chelation; diferric transferrin; disease phenotype; erythroid differentiation; heme 1; hepcidin; human TFRC protein; human disease; improved; in vivo; insight; iron metabolism; mortality; pre-clinical; programs; therapeutic development; uptake; zinc protoporphyrin

DESCRIPTION (provided by applicant): This application describes a five-year mentored training program to develop an independent clinician-scientist whose career in academic medicine will focus on furthering our understanding of human red blood cell development. Beta-thalassemia in humans is a disease associated with anemia, splenomegaly, and ineffective erythropoiesis; iron overload in this disease results from transfusion and increased iron absorption from hepcidin deficiency. Our lab previously demonstrated that treatment with transferrin in mice with beta- thalassemia improves the disease phenotype with reversal of anemia, splenomegaly, and ineffective erythropoiesis and an increase in hepcidin expression. Surprisingly, although there are more red cells in circulation, their size and hemoglobin content is reduced in treated mice. We hypothesize that supplemental transferrin results in more iron deficient erythropoiesis, reducing the imbalance between heme, alpha-globin, and beta-globin synthesis in beta-thalassemia. My goal in the studies proposed for this award is to test this hypothesis. I plan two specific aims to evaluate this: 1) to determine if iron uptake by erythroid precursors is altered when additional transferrin is available in vivo and in vitro; and 2) to determine if the regulation and production of hemoglobin components as well as iron and heme export is altered when supplemental transferrin is added in normal and beta-thalassemic cells in vivo and in vitro. These studies will test my hypothesis that exogenous transferrin restricts iron entry into erythroid precursors and protects early erythroid cells from heme toxicity, will provide insight into the physiology responsible for the phenotype in beta- thalassemia, and will further our understanding of normal and disordered erythropoiesis. I will accomplish these specific aims by the following methods: 1) characterize the ferrokinetics of erythroid precursors in mice given additional transferrin, analyze the expression of transferrin receptor in these cells in vivo, and evaluate cytosolic iron uptake in cell lines and human cells in culture; 2) evaluate expression levels and regulators of heme and globin production, measure levels of zinc protoporphyrin and free heme in the cytosol, and characterize the effect on FLVCR and FPN-1B, heme and iron exporters, respectively, during erythroid precursor differentiation in mouse bone marrow and spleen samples as well as in human samples in culture. These studies focus on basic red blood cell physiology and may lend insight into human diseases where red blood cell development is disturbed. Lastly, progress in understanding mechanisms of transferrin efficacy in beta-thalassemic mice may enable its therapeutic development for patients with this disease. PUBLIC HEALTH RELEVANCE: Our laboratory previously demonstrated that using the main iron carrying molecule, transferrin, to treat mice with the disease, beta-thalassemia reverses many of the abnormalities present in this disease. We will systematically analyze the mechanisms underlying this effect in order to create a foundation for further testing of transferrin. The treatment for Beta-thalassemia is suboptimal, but has remained unchanged for the past fifty years. Ultimately, our goal is to provide an alternative treatment for these patients that could possibly be effective for other diseases associated with anemia and iron overload.

描述（由申请人提供）：本申请描述了一项为期五年的指导培训计划，以开发一个独立的临床医生，其学术医学的职业将着重于我们对人类红细胞发展的理解。人类中的β-甲性甲性疾病是一种与贫血，脾肿大和无效的红细胞生成有关的疾病。该疾病中的铁超负荷是由于输血和肝素缺乏的铁吸收增加而导致的。我们的实验室先前证明，在β-丘脑的小鼠中用转铁蛋白进行治疗可以通过贫血，脾肿大和无效的erythropoiesis逆转来改善疾病表型，并提高肝素表达。令人惊讶的是，尽管循环中有更多的红细胞，但在处理的小鼠中，它们的大小和血红蛋白含量降低。我们假设补充转铁蛋白会导致更多的铁缺乏红细胞生成，从而降低了血红素，α-珠蛋白和β-珠蛋白合成之间的不平衡。我在该奖项提出的研究中的目标是检验该假设。我计划两个具体的目的来评估这一点：1）确定当在体内和体外可用的其他转移蛋白时，会改变红细胞前体的铁摄取； 2）确定当在体内和体外添加补充β-丘脑症细胞中补充转运蛋白时，血红蛋白成分以及铁和血红素的调节以及铁和血红素是否会改变。这些研究将检验我的假设，即外源转铁蛋白限制了铁进入红斑前体，并保护早期的红细胞细胞免受血红素毒性的侵害，它将深入了解负责β-甲状腺肿的表型的生理学，并将进一步进一步了解正常和无序的eriythropoiesis。我将通过以下方法来完成这些特定目标：1）表征给定其他转铁蛋白的小鼠红斑前体的铁子学，分析体内这些细胞中转移蛋白受体的表达，并评估培养细胞和人类细胞中的胞质铁摄取； 2）评估血红素和球蛋白产生的表达水平和调节剂，锌原磷脂的测量水平和细胞质中的自由血红素水平，并分别表征对FLVCR和FPN-1b，血红素和铁出口商的影响，在红细胞骨骨髓和斑点样品中的红细胞前体分化过程中，在红细胞的前体分化过程中以及人类培养物中的样品中的效果。这些研究集中于基本的红细胞生理学，并可能洞悉被扰乱红细胞发育的人类疾病。最后，理解β-丘脑小鼠的转铁蛋白功效机制方面的进展可能会使该疾病患者的治疗性发育。 公共卫生相关性：我们的实验室以前证明，使用主要铁分子转铁蛋白，将疾病治疗小鼠，β-核阿无血病逆转了这种疾病中存在的许多异常。我们将系统地分析此效果的基础机制，以创建进一步测试转铁蛋白的基础。 β-地中海贫血的治疗方法是最佳的，但在过去的五十年中一直保持不变。最终，我们的目标是为这些患者提供另一种治疗方法，该治疗可能对与贫血和铁超负荷相关的其他疾病有效。