The Impact of Hemoglobin S on Red Blood Cell Nitric Oxide Production

血红蛋白 S 对红细胞一氧化氮生成的影响

基本信息

批准号：
9376631
负责人：
Jon A Detterich
金额：
$ 8.33万
依托单位：
CHILDREN'S HOSPITAL OF LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-11 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9376631
关键词：
Acute Adhesions Affect Alpha Cell American Arteries Basal Cell Bioavailable Biochemical Biological Availability Biological Models Biophysics Blood Blood Vessels California Cells Centers for Disease Control and Prevention (U.S.)Child Chronic Clinical Research Complex Data Collection Diffuse Disease Dissociation Enzymes Erythrocytes Functional disorder Gene Mutation Generations Genes Goals Grant Health Heart Heme Hemoglobin Hemoglobin concentration result Hemolysis Hospitalization Human Hypoxia Inclusion Bodies Insurance Carriers Iron Kidney Diseases Laboratories Left Link Mechanical Stress Mechanics Mediating Mediator of activation protein Medicaid Mentored Patient-Oriented Research Career Development Award Metabolic Methods Modeling Morbidity - disease rate N,N-dimethylarginine NOS3 gene Nitric Oxide Nitrites Oxygen Pain Patients Phenotype Plasma Platelet aggregation Play Polymers Predisposition Priapism Privatization Process Production Pulmonary Hypertension Pulmonary artery structure Regulation Research Proposals Research Training Role Rupture Sickle Cell Sickle Cell Anemia Sickle Hemoglobin Skin Ulcer Source Stroke United States Variant Vascular Diseases Vascular remodeling Work acute chest syndrome arginase base beta Globin career development cost design improved inhibitor/antagonist mortality multimodality new therapeutic target novel oxidative damage patient oriented research polymerization pressure shear stress sickling statistics stem therapeutic target tissue oxygenation translational study vascular bed vascular inflammation vasoconstriction

项目摘要

Project Summary Sickle cell disease is a progressive vasculopathy stemming from decreased red blood cell (RBC) deformability. Vascular disease is at the heart of both acute and chronic sickle disease, including pain crisis, acute chest syndrome, stroke, skin ulcers, and pulmonary hypertension. However, the mechanisms linking decreased RBC deformability to chronic vasculopathy are multifactorial and poorly characterized. Nitric oxide (NO) is the key mediator linking blood mechanics to vessel tone and vascular remodeling. NO bioavailability is diminished in SCD because decellularized hemoglobin and arginase, released during hemolysis, scavenge NO and lower endothelial NO production. Recent evidence suggests that 50% of bioavailable NO is synthesized within RBC, themselves, through a shear-activated eNOS enzyme. RBC NO is primarily converted to nitrite and nitrosylated hemoglobins when tissue oxygenation is high, but deoxygenated hemoglobin converts these species to nitric oxide under hypoxic conditions. Thus, RBC generated NO appears to be a vital mediator of oxygen supply and demand and its role in sickle cell vasculopathy is unexplored. Early results from our lab suggest that tissue oxygenation is dependent on RBC deformability at high shear. Deformation of healthy and SCD RBC increases NO production to a similar degree, while basal NO production is higher in SCD RBC. With the addition of nitrite to fully oxygenated SCD RBC basal production of NO is increased whereas it did not change in healthy RBC. Our overall goal is to demonstrate that nitrite and NOS contribute to RBC NO production, which in turn plays a significant role in the vascular health of normal healthy subjects and patients with sickle cell disease, a human model of diffuse vasculopathy. This research proposal leverages our current work in sickle cell disease vascular function assessment and novel laboratory methods in RBC nitric oxide production. Multimodal characterization of the different vascular beds will lead to improved phenotypic categorization and pathophysiological links to the underlying RBC biophysical/biochemical derangements. We continue to explore whether RBC-generated NO has the ability to decreases platelet aggregation. The studies proposed in Aim I and II will separate the effect of basal and shear-mediated NO production allowing us to determine control mechanisms in healthy and SCD patients. We know that a paradox exists whereby tissue oxygenation is low in non-transfused SCD subjects, while microcirculatory flow is increased. This may be due to changes in nitric oxide production due to nitrite reduction from hemoglobin S deoxygenation, shear-mediated changes in NO production or both. Our overall design, which performs Aims I/II simultaneously with studies in Aim III, should resolve this paradox. The K23 mechanism represents the natural extension my career development to date, combining my previous laboratory and patient-oriented research expertise with the specific clinical research training necessary to conduct large translational studies of novel targets in vascular dysfunction.

项目概要镰状细胞病是一种由红细胞 (RBC) 变形能力下降引起的进行性血管病变。血管疾病是急性和慢性镰状病的核心，包括疼痛危象、急性胸部综合征、中风、皮肤溃疡和肺动脉高压。然而，连接机制减少了红细胞变形性对慢性血管病变的影响是多因素的，且特征很少。一氧化氮 (NO) 是将血液力学与血管张力和血管重塑联系起来的关键介质。 NO生物利用度降低在 SCD 中，因为溶血过程中释放的脱细胞血红蛋白和精氨酸酶可清除 NO 并降低内皮细胞NO的产生。最近的证据表明 50% 的生物可利用 NO 是在红细胞内合成的，通过剪切激活的 eNOS 酶自身。红细胞 NO 主要转化为亚硝酸盐当组织氧合作用高时，亚硝化血红蛋白会产生亚硝化血红蛋白，但脱氧血红蛋白会将这些转化为亚硝化血红蛋白。缺氧条件下转化为一氧化氮。因此，RBC 产生的 NO 似乎是氧气的供应和需求及其在镰状细胞性血管病中的作用尚未被探索。我们实验室的早期结果表明组织氧合取决于红细胞在高剪切力下的变形能力。健康与变形 SCD RBC 增加 NO 产生的程度相似，而 SCD RBC 的基础 NO 产生更高。和在完全氧化的 SCD RBC 中添加亚硝酸盐，NO 的基础产量增加，而没有增加健康红细胞的变化。我们的总体目标是证明亚硝酸盐和 NOS 有助于红细胞一氧化氮 (RBC NO) 产生，反过来对正常健康受试者的血管健康起着重要作用患有镰状细胞病的患者，这是一种弥漫性血管病的人类模型。本研究提案利用我们目前在镰状细胞病血管功能评估方面的工作和新颖的实验室方法红细胞一氧化氮的产生。不同血管床的多模态特征将导致改进表型分类和与潜在红细胞生物物理/生化的病理生理学联系精神错乱。我们继续探索红细胞产生的NO是否具有减少血小板的能力聚合。目标 I 和 II 中提出的研究将区分基础 NO 和剪切介导的 NO 的影响生产使我们能够确定健康和 SCD 患者的控制机制。我们知道，一个存在一个悖论，即非输血 SCD 受试者的组织氧合作用较低，而微循环流量增加了。这可能是由于血红蛋白 S 中的亚硝酸盐还原导致一氧化氮生成发生变化脱氧、剪切介导的 NO 产生变化或两者兼而有之。我们的整体设计，实现了目标 I/II 与目标 III 的研究同时进行，应该可以解决这个悖论。 K23机制代表自然延伸我迄今为止的职业发展，结合了我以前的实验室和以患者为导向的研究专业知识以及进行大型转化研究所需的特定临床研究培训血管功能障碍的新靶点。