MECHANISMS AND MODULATION OF ACCELLULAR HbA TOXICITY

描述（由申请人提供）：该项目旨在确定与血液中脱细胞血红蛋白（Hbs）相关的毒性的机制，并建立预防或逆转这些毒性的策略。研究结果将对血液学和输血医学产生重大影响：(1)提供合理的治疗方法，以尽量减少与慢性或急性疾病患者的自体溶血红细胞和用于输血的异源储存血液释放Hb相关的临床问题；(2)确定细胞外Hb基氧载体（HBOCs）商业失败的根本原因，并提供减轻或消除这些问题的策略。优化其体积扩张和组织灌注效果，降低毒性。长期目标是提供更安全、更有效的输血，使用使输血策略与临床需要和新鲜储存血液的可用性相匹配的治疗方案。这些目标将通过3个项目和4个核心设施来实现。项目1 （UCSD， M. Intaglietta， PI）将使用微血管灌注标记物来识别Hb相关的毛细血管功能变化，并检查急性和慢性血管功能障碍期间的Hb毒性。项目2 （Rice U.， J. Olson， PI和A. Alayash， FDA）将设计具有不同（高/低）02结合、NO双氧、氧化和变性特性的重组Hb，并使用它们来测试NO清除、氧化降解、变性和沉淀的重要性，以及在细胞、器官和整个动物模型系统中引起血浆Hb毒性的清除受损。项目3 （AECOM， J. Friedman， PI）将评估Hb的聚乙二醇化或聚合，Hb产生生物活性NO，注射释放NO或GSNO的纳米颗粒，以及注入还原剂和接触珠蛋白是否可以有效地用于限制脱细胞Hb氧化反应产生的毒性。四个核心是：核心A，行政单位（AECOM, Friedman， PI）；核心B， HbA化学修饰和纳米颗粒生产（AECOM, Nacharaju，领导者）；核心C，体内毒性研究的重组HbA生产（Rice U. Olson，领导）；核心D，化学，细胞和动物毒性评估（FDA， Alayash领导者）

DESCRIPTION (provided by applicant): This program seeks to determine the mechanisms responsible for toxicities associated with acellular hemoglobins (Hbs) in blood and to establish strategies to prevent or reverse these toxicities. The results will have a significant impact on hematology and transfusion medicine by: (1) providing rational therapies to minimize the clinical problems associated with Hb released from autologous, hemolyzed red blood cells in patients with chronic or acute diseases and from heterologous stored blood used for transfusions and (2) Identifying the underlying causes of the commercial failure of extracellular Hb-based oxygen carriers (HBOCs), providing strategies to mitigate or eliminate these problems, and optimizing their efficacy for volume expansion and tissue perfusion with reduced toxicity. A long term goal is to provide safer and more effective blood transfusions using therapeutic options that match transfusion strategies with clinical needs and availability of fresh stored blood. These objectives will be achieved through 3 projects, and 4 core facilities. Project 1 (UCSD, M. Intaglietta, PI) wil use microvascular perfusion markers to identity Hb-related changes in capillary function and examine Hb toxicity during acute and chronic vascular dysfunction. Project 2 (Rice U., J. Olson, PI and A. Alayash, FDA) will engineer recombinant Hb with varied (high/low) 02 binding, NO dioxygenation, oxidation, and denaturation properties and use them to test the importance of NO scavenging, oxidative degradation, denaturation and precipitation, and impaired clearance in causing plasma Hb toxicity in cellular, organ, and whole animal model systems. Project 3 (AECOM, J. Friedman, PI) will evaluate whether PEGylation or polymerization of Hb, generation of bioactive NO by Hb, injection of nanoparticles releasing NO or GSNO, and the infusion of reducing agents and haptoglobin can be used effectively to limit toxicity derived from the oxidative reactions of acellular Hb. The four Cores are: Core A, Administrative unit (AECOM, Friedman, PI); Core B, HbA Chemical Modifications and Nanoparticle Production (AECOM, Nacharaju, leader); Core C, Recombinant HbA Production for In Vivo Toxicity Studies (Rice U. Olson, leader); Core D, Chemical, Cellular, And Animal Toxicity Evaluations (FDA, Alayash leader)