Molecular characterization of biliverdin IXbeta reductase

申请人姓名(最后、第一、中间)：巴侯，瓦迪·F。 项目摘要/摘要 这项拨款申请中提出的研究建立在广泛的遗传学、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还原酶作为新的细胞靶标的作用 在应激性造血状态下调节人类血小板的产生，并伴随着对 红系发育和再繁殖。尽管人们在很大程度上把血红素的降解作为一种加工过程来研究 旨在清除细胞衰老(或新陈代谢)过程中产生的促氧化(游离)血红素的途径， 众所周知，血红素分解代谢酶还维持细胞信号和细胞保护的功能(S)，以及 四吡咯的副产物胆绿素(BV)和胆红素(BR)在氧化还原反应中作为有效的缓冲作用(S) 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 分解代谢在一条独特的代谢途径中的作用，该途径控制着不同的造血系的命运 对红系/巨核细胞平衡的影响。研究目标是通过两个协同作用来实现的 特异靶，旨在(1)阐明BLVRB调节的MK/红系氧化还原偶联的细胞机制 和体外细胞保护，以及(2)定义和扩展谱系限制物种形成和 体内的细胞保护，共同设计来剖析Blvrb调节的控制E/Meg的扰动通路 应激造血过程中MEP的谱系物种形成。基础科学的影响广泛地与 (1)造血的代谢和生物能量影响，(2)血红素调节的氧化还原化学，以及(3) 新颖的细胞靶标验证。临床/翻译含义旨在增强我们的理解 研究与干细胞新陈代谢、衰老、贫血和血小板生成有关的疾病机制。独一无二 产生和鉴定的试剂和细胞系包括(1)Blvrb和BlvrA缺乏的小鼠模型， (2)具有靶向BLRB基因敲除的IPSC模型，(3)胆绿素IX(和IX，IX)异构体检测和 生产方法。所有拟议的研究都是根据受试者队列中先前存在的研究制定的，以及 建议的实验是基于目前可用的或先进的试剂和专业知识 研究团队之间的发展。 PHS 416-9(6/09版)页面延续格式页面

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