Red blood cell ATP export and transfusion in sepsis

脓毒症中红细胞 ATP 输出和输血

• 批准号: 10584768
• 负责人: ALLAN DOCTOR
• 金额: $ 73.14万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-05 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10584768
• 关键词: Acute Lung Injury; Acute Respiratory Distress Syndrome; Adenine; Adhesions; Adhesives; Adult; Anemia; Attenuated; Blood; Blood Transfusion; Blood Vessels; Blood flow; Blood specimen; Caliber; Cardiac Output; Cells; Child; Clinical; Consumption; Coupling; Critical Illness; Cryopreserved Cell; Depressed mood; Endothelial Cells; Endothelium; Ensure; Erythrocyte Transfusion; Erythrocytes; Exposure to; Functional disorder; Genetic; Hemoglobin; Homeostasis; Human; Hypoxemia; Hypoxia; Immune response; Impairment; In Vitro; Incubated; Infection; Inflammation; Influenza; Inosine; Intervention; Investigation; Leukocytes; Lung; Mediating; Mediator; Metabolic; Methods; Modeling; Morbidity - disease rate; Mus; Oral; Organ; Outcome; Oxygen; Patients; Peripheral; Persons; Phase; Phenotype; Pyruvate; Pyruvate Kinase; Respiration Disorders; Respiratory physiology; Risk; Risk Factors; Role; Sampling; Scheme; Sepsis; Signal Transduction; Site; Specimen; Testing; Therapeutic; Tissues; Transfusion; Translations; biobank; candidate identification; cecal ligation puncture; cell injury; cell type; clinical investigation; clinical translation; clinically relevant; design; empowerment; experimental study; genetic approach; improved; in vivo; inorganic phosphate; insight; lead candidate; mortality; mouse model; novel; pharmacologic; preservation; prospective; respiratory; response; septic; tissue oxygenation; uptake

ABSTRACT O2 uptake in the lung and O2 delivery peripherally depend on the efficient matching of blood flow to regional O2 availability in the lung and O2 consumption in tissues. To achieve this matching, red blood cell (RBC) hemoglobin allostery regulates not only trans-erythrocytic O2 flux but also RBC export of vasoactive mediators that respond to O2 demand. RBCs export vasoregulatory ATP basally and in response to O2 deficit. This RBC-based vascular control of the uptake and delivery of O2 may be disrupted by endogenous (e.g., in sepsis) and exogenous (via storage for transfusion) RBC injuries. Septic persons with moderate anemia are frequently transfused, but infrequently benefit. Yet conversely any anemia is a negative risk factor. Lung morbidity is frequent after RBC transfusion, possibly due to impaired RBC ability to export ATP, disrupting O2 uptake via pulmonary RBC- endothelial adhesion. We show in septic mice (cecal ligation/puncture, CLP) that the RBC’s ability to produce and export ATP is impaired. We will test the hypothesis that the O2-transport dysfunction in sepsis is mediated in part by impaired export by RBCs of vasoregulatory ATP, a dysfunction compounded by transfused RBCs, exacerbating acute lung injury (ALI) and hypoxemia, by achieving these Aims: Aim 1. Determine the role of RBC ATP export in mortality and ALI in a mouse model of sepsis and transfusion. Exchange transfusion of CLP RBCs into healthy mice exposed to hypoxia drives mortality. RBC ATP export takes place via pannexin 1 (Px1). We will determine the role and mechanism of depressed RBC ATP export via Px1 in the mortality, ALI, and O2 transport responses to sepsis (CLP or severe influenza) and transfusion in mice using genetic and pharmacological approaches. Aim 2. Determine the influence of augmenting transfusate RBC ATP content and/or export on organ function and O2 transport in septic mice. RBC ATP export can be augmented via clinically available approaches: hypoxic RBC storage; transfusate incubation with PIPA (phosphate, inosine, pyruvate, adenine) solution that preserves stored-RBC ATP and DPG; or using an activator of RBC pyruvate kinase (PKR), which augments RBC ATP with little effect on DPG or P50. We will test these approaches to augment or preserve RBC ATP content on ATP export in mice transfused during sepsis. Aim 3. Determine the influence of human sepsis on RBC vasoregulatory function ex vivo, and the functional influence of candidate modulators of ATP content and export in septic RBCs. We validated a novel RBC cryopreservation scheme with superior phenotype fidelity. We built a unique biobank of RBC specimens from septic children and adults. We prospectively sampled over 150 patients with severe sepsis; most subjects have ALI. We will determine the influence of translation-ready lead candidates identified in Aim 2 to augment RBC ATP export on key RBC respiratory functions: vasoactivity, anti-adhesivity, and O2 transport. We will model the effects of transfusate intervention in admixed septic and stored RBCs. Our novel focus on disrupted signaling by RBCs will produce novel, practical, and relevant insight into respiratory dysfunction in sepsis and transfusion.

摘要 肺中的氧气摄取和外周的氧气输送依赖于血流与局部氧气的有效匹配 肺中的利用度和组织中的氧气消耗。为了实现这种匹配，红细胞(RBC)血红蛋白 变构不仅调节跨红细胞的O2流量，而且调节RBC输出的血管活性介质 对氧气的需求。红细胞基础上输出血管调节性三磷酸腺苷，并对氧气缺乏作出反应。这种以红细胞为基础的血管 内源性(例如，在脓毒症中)和外源性(通过 储存输血)RBC损伤。有中度贫血的败血症患者经常输血，但 很少受益。然而，相反，任何贫血都是一个负面的风险因素。RBC后肺部并发症多见 输血，可能是由于红细胞输出ATP的能力受损，扰乱了通过肺红细胞摄取氧气的能力- 内皮细胞粘连。我们在脓毒症小鼠(盲肠结扎/穿孔，CLP)中表明，红细胞产生 以及出口ATP受到损害。我们将验证脓毒症患者O2-转运功能障碍的假设 部分原因是红细胞对血管调节三磷酸腺苷的输出受损，这种功能障碍由 通过输注红细胞，加重急性肺损伤(ALI)和低氧血症，达到以下目的：1. 在脓毒症和输血的小鼠模型中，确定RBC-ATP输出在死亡率和ALI中的作用。 在暴露在低氧环境下的健康小鼠中交换输注CLP红细胞可增加死亡率。RBC ATP导出 通过pAnnexin 1(PX1)发生。我们将通过以下途径确定抑制红细胞ATP出口的作用和机制 PX1在脓毒症(CLP或严重流感)和输血引起的小鼠死亡率、ALI和O2转运反应中的作用 使用遗传和药理学方法。目的2.确定增加输血量的影响 败血症小鼠红细胞ATP含量和/或输出对器官功能和O2转运的影响。RBC ATP出口可以 通过临床可用的方法：低氧保存红细胞；与PIPA输注孵育 (磷酸盐、肌苷、丙酮酸、腺嘌呤)保存储存的红细胞ATP和DPG的溶液；或使用激活剂 RBC丙酮酸激酶(PKR)升高RBC ATP，但对DPG或P50影响不大。我们将测试这些 在脓毒症期间输血的小鼠体内增加或保存红细胞ATP含量的方法。目标3. 体外测定人脓毒症对RBC血管调节功能的影响 脓毒症红细胞中ATP含量和输出的候选调节剂的影响。我们验证了一种新的红细胞 表型保真度高的冷冻保存方案。我们建立了一个独特的红血球样本生物库 败血症儿童和成人。我们前瞻性地抽样了150多名严重脓毒症患者；大多数受试者都有 阿里。我们将确定目标2中确定的可用于翻译的主要候选人对增强RBC的影响 ATP输出对关键的红细胞呼吸功能：血管活性、抗粘附性和氧气运输。我们将为 输注干预对混合败血症和储存红细胞的影响。我们的新重点是通过以下方式中断信号 红细胞计数将对败血症和输血中的呼吸功能障碍产生新的、实用的和相关的见解。