Molecular characterization of biliverdin IXbeta reductase

申请人姓名（姓、名、中）：BAHOU，Wadie F. 项目总结/摘要 这项资助申请中提出的研究建立在广泛的遗传、生物化学和动物研究的基础上 旨在进一步表征和验证胆绿素IX还原酶（BLVRB）作为一种新的细胞靶点， 在应激性造血情况下调节人血小板生成， 红细胞发育和再增殖。虽然血红素降解主要是作为一种加工过程来研究的， 旨在清除细胞衰老（或代谢）期间产生的促氧化剂（游离）血红素的途径， 还已知血红素分解代谢酶在细胞信号传导和细胞保护中维持功能， 四吡咯副产物胆绿素（BV）和胆红素（BR）在氧化还原反应中作为有效的缓冲剂， 氧化应激我们现在挑战现有的教条，假设涉及血红素的氧化还原调节活动 catalysts在一个独特的代谢途径中发挥作用，控制造血谱系的命运， 对红细胞/巨核细胞平衡的影响。研究目标是通过两个协同 特定目的，旨在（1）描述BLVRB调节的Mk/红细胞氧化还原偶联的细胞机制 和体外细胞保护，（2）定义和扩展谱系限制性物种形成的机制， 体内细胞保护，共同设计用于剖析控制E/Meg的Blvrb调节的扰动途径 应激造血过程中MEP的谱系物种形成。基础科学的影响广泛涉及到 (1)造血的代谢和生物能量后果，（2）血红素调节的氧化还原化学，和（3） 新的细胞靶点验证。临床/翻译含义旨在增强我们的理解 与干细胞代谢、衰老、贫血和血小板生成有关的疾病机制。独特 生成和表征的试剂和细胞系包括（1）Blvrb和Blvra缺陷的鼠模型， (2)具有靶向BLVRB敲除的iPSC模型，（3）胆绿素IX β（和IX β，IX β）异构体检测，和 生产方法。所有拟定研究均基于受试者队列中的既有研究制定，并且 拟议的实验是基于目前可用或先进的试剂和专业知识。 研究团队的发展。 PHS 416-9（Rev. 6/09）

Name of Applicant (Last, First, Middle): BAHOU, Wadie F. Project Summary/Abstract Research proposed in this grant application builds on extensive genetic, biochemical and animal studies designed to further characterize and validate biliverdin IX reductase (BLVRB) as a novel cellular target regulating human platelet production in situations of stress hematopoiesis, with concomitant effects on erythroid development and repopulation. Although heme degradation is largely studied as a processing pathway designed to clear pro-oxidant (free) heme generated during cellular senescence (or metabolism), heme catabolic enzymes are also known to maintain function(s) in cellular signaling and cytoprotection, and tetrapyrrole byproducts biliverdin (BV) and bilirubin (BR) function in redox reactions as potent buffer(s) against oxidant stress. We now challenge existing dogma, hypothesizing that redox-regulated activity involving heme catabolism functions in a unique metabolic pathway controlling hematopoietic lineage fate with divergent effects on erythroid/megakaryocyte balance. Research goals are accomplished through two synergistic specific aims, designed to (1) delineate cellular mechanisms of BLVRB-regulated Mk/Erythroid redox coupling and cytoprotection in vitro, and (2) define and expand upon mechanisms of lineage-restricted speciation and cytoprotection in vivo, collectively designed to dissect Blvrb-regulated perturbed pathways controlling E/Meg lineage speciation from MEPs during stress hematopoiesis. Basic science implications are broadly relevant to (1) metabolic and bioenergetic consequences of hematopoiesis, (2) heme-regulated redox chemistry, and (3) novel cellular target validation. Clinical/translational implications are designed to enhance our understanding of mechanisms of disease pertaining to stem cell metabolism, aging, anemia and platelet production. Unique reagents and cell lines generated and characterized include (1) murine models of Blvrb- and Blvra-deficiency, (2) iPSC models with targeted BLVRB knock-outs, (3) biliverdin IX (and IX, IX) isomer detection and production methodologies. All proposed studies are formulated on pre-existing studies in subject cohorts, and proposed experiments are predicated on reagents and expertise currently available or in advanced development among the research team. PHS 416-9 (Rev. 6/09) Page Continuation Format Page