Membrane potential and Calcium Signaling in Neutrophil Development and Inflammation

中性粒细胞发育和炎症中的膜电位和钙信号传导

• 批准号: 10529325
• 负责人: Regina Clemens
• 金额: $ 39.21万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-19 至 2026-10-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10529325
• 关键词: Acute; Acute Lung Injury; Bacteria; Bacterial Infections; Biological; Biology; Calcium; Calcium Channel; Calcium Signaling; Calcium ion; Calcium-Activated Potassium Channel; Cell membrane; Cell physiology; Cells; Charge; Clinical; Communicable Diseases; Coupling; Cytoplasmic Granules; Cytotoxin; Data; Development; Disease; Emergency Situation; Enzymes; Event; Functional disorder; Genetic; Goals; Gout; Granulopoiesis; Hemolysin; Host Defense; Human; Immune; Infection; Inflammation; Inflammatory; Innate Immune System; Ion Channel; Knowledge; Laboratories; Lymphocyte; Mediating; Mediator; Membrane Potentials; Molecular; Mus; Mycoses; Neutropenia; Neutrophil Activation; Pathogenesis; Pathway interactions; Patients; Predisposition; Process; Reactive Oxygen Species; Regulation; Rheumatoid Arthritis; Role; Sepsis; Signal Pathway; Signal Transduction; Staphylococcus aureus; Stimulus; Testing; Therapeutic Intervention; Tissues; Toxic Neutrophil; Toxin; Virulence; chronic inflammatory disease; driving force; extracellular; first responder; immune system function; insight; mast cell; mouse model; neutrophil; pathogen; pathogenic bacteria; response

PROJECT SUMMARY Neutrophils are essential for host defense against bacteria, however toxic neutrophil mediators such as reactive oxygen radicals, granule enzymes and neutrophil extracellular traps contribute the pathogenesis of acute and chronic inflammatory diseases. While the ability of neutrophils to phagocytose and kill pathogens has been known for over 100 years, our knowledge of the molecular mechanisms guiding neutrophil activation lags significantly behind that of other immune cells, precluding the development of strategic therapeutic interventions targeting neutrophils. Our long-term goal is to define the mechanisms by which ion channels and associated signaling pathways regulate neutrophil activation, and to leverage this knowledge to modify disease. Calcium signals initiated via store-operated calcium entry (SOCE) are required for neutrophil activation. The cell membrane potential directly influences influx of positively charged calcium ions. While the functional role of the cell membrane potential has been extensively studied in excitable cells, little is known about how the membrane potential modifies cellular processes in neutrophils in the context of development and inflammation. This proposal is based on four fundamental observations from our laboratory: 1) ORAI1 and ORAI2 calcium channels are critical for neutrophil SOCE and host defense during infection with S. aureus. 2) Calcium responses in mouse neutrophils are heterogenous, with the magnitude of the calcium response modulated in part by differential regulation of the cell membrane potential. 3) Expression of the calcium- activated potassium channel KCa3.1 (Kcnn4) drives cell hyperpolarization and enhanced SOCE in a subset of neutrophils. 4) The membrane potential-SOCE relationship is modulated during neutrophil development and emergency granulopoiesis. Moreover, we have observed that a S. aureus pore-forming toxin manipulates the neutrophil membrane potential and SOCE. Together these observations illustrate that the membrane potential is a key modifier of calcium-dependent neutrophil function, and suggest that this pathway is a strategic target of human pathogenic bacteria that secrete pore-forming cytotoxins to overcome host neutrophil defenses. The objective of this proposal is to characterize the mechanisms by which membrane potential regulates SOCE during neutrophil development and inflammation. We will test the central hypothesis that the membrane potential is a critical modifier of neutrophil calcium signaling in mature neutrophils and homeostatic and emergency granulopoiesis. In Aims 1 and 2 we will investigate the role of KCa3.1 in neutrophil SOCE and calcium-dependent activation in mature and developing neutrophils. In Aim 3 we will expand these studies to investigate how exogenous manipulation of the cell membrane potential by bacterial pore-forming toxins disrupts calcium-dependent neutrophil function. The insight derived from these studies is anticipated to engender new clinical opportunities for modulation of neutrophil-dependent infectious and inflammatory disease, and potentially inform a broader understanding of membrane potential in immune cell function.

项目摘要 中性粒细胞对于宿主防御细菌至关重要，但是有毒的中性粒细胞介质（例如 活性氧自由基，颗粒酶和中性粒细胞外陷阱促成 急性和慢性炎症性疾病。而嗜中性粒细胞的吞噬和杀死病原体的能力 我们闻名了100多年，我们对指导中性粒细胞激活的分子机制的了解 落后于其他免疫细胞的滞后，排除了战略治疗的发展 针对中性粒细胞的干预措施。我们的长期目标是定义离子渠道和 相关的信号通路调节中性粒细胞的激活，并利用这些知识来修改 疾病。中性粒细胞需要通过商店经营的钙进入（SOCE）发起的钙信号 激活。细胞膜电位直接影响带正电荷的钙离子的流入。而 细胞膜电位的功能作用已在激发细胞中广泛研究，鲜为人知 关于膜电位如何在发育的背景下改变中性粒细胞中的细胞过程 和炎症。该提案基于我们实验室的四个基本观察：1）Orai1和 Orai2钙通道对于伴有金黄色葡萄球菌感染期间中性粒细胞SOCE和宿主防御至关重要。 2） 小鼠中性粒细胞中的钙反应是异质的，钙反应的大小 部分由细胞膜电位的差异调节调节。 3）钙的表达 活化的钾通道KCA3.1（KCNN4）驱动细胞超极化并在一部分中增强了SOCE 中性粒细胞。 4）在中性粒细胞发育和 紧急颗粒。此外，我们已经观察到金黄色葡萄球菌形成毛孔的毒素可以操纵 中性粒细胞膜的潜力和SOCE。这些观察结果共同说明了膜电位 是钙依赖性嗜中性粒细胞功能的关键修饰符，并建议该途径是一种战略目标 分泌形成孔的细胞毒素以克服宿主嗜中性粒细胞防御的人类致病细菌。这 该建议的目的是表征膜电位调节SOCE的机制 在中性粒细胞发育和炎症期间。我们将测试膜的中心假设 势是成熟嗜中性粒细胞和稳态中嗜中性粒细胞信号传导的关键修饰剂， 紧急颗粒。在目标1和2中，我们将研究KCA3.1在中性粒细胞SOCE和 成熟和发展中性粒细胞中钙依赖性激活。在AIM 3中，我们将将这些研究扩展到 研究如何通过细菌形成孔毒素对细胞膜电位的外源操纵 破坏依赖钙的嗜中性粒细胞功能。预计从这些研究中得出的见解将会 为调节中性粒细胞依赖性感染性和炎症引起新的临床机会 疾病，并有可能更广泛地了解免疫细胞功能中的膜潜力。