Validation of extracellular histones as biomarker and therapeutic target in sepsi

描述（由申请人提供）：本申请涉及广泛的挑战领域（03）生物标志物的发现和验证以及特定的挑战主题，03- hl -101：鉴定和验证临床相关的、可量化的血液、血管、心脏和呼吸道功能障碍诊断和治疗反应的生物标志物。本应用侧重于细胞外组蛋白在脓毒症病理生理学中的新作用，特别是旨在验证组蛋白作为严重脓毒症和伴随的多器官功能障碍或衰竭（MODS/MOF）的生物标志物、介质和治疗靶点。严重脓毒症是一个主要的医学问题，在美国，每年约有75万名重症监护室患者入院，花费超过170亿美元，造成22.5万人死亡。我们的研究小组最近发现，核组蛋白在细胞外环境中释放，以响应炎症挑战，是败血症诱导的器官衰竭和死亡的重要介质。组蛋白血浆水平与动物（小鼠和狒狒）以及脓毒症患者的器官功能障碍和死亡相关。Xigris（活化蛋白C）可切割组蛋白并降低其毒性。用抗体或阻断肽抑制组蛋白可拯救实验性致死性败血症小鼠。本提案的目标是：(i)验证细胞外组蛋白作为介导组织损伤，最终导致器官衰竭的重要生物标志物，以及（ii）表征两种组蛋白阻断策略的治疗潜力。目的1采用外源性组蛋白激发来表征组蛋白在四种脓毒症小鼠模型中的体内细胞毒性、炎症和微血栓作用以及组蛋白的治疗靶向性。目的2将组蛋白抑制方法转化为大型动物大肠杆菌败血症的临床相关模型。目标3。将验证血浆组蛋白作为与临床结果相关的器官功能障碍的预后生物标志物，并有助于确定将受益于组蛋白阻断特异性抗菌治疗的患者。总的来说，该项目将促进对脓毒症诱导器官损伤的病理生理学的理解，将验证新的生物标志物，并为脓毒症和MOF患者开发新的潜在治疗方法。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (03) Biomarker Discovery and Validation and specific Challenge Topic, 03-HL-101: Identify and validate clinically relevant, quantifiable biomarkers of diagnostic and therapeutic responses for blood, vascular, cardiac, and respiratory tract dysfunction This application focuses on the novel role of extracellular histones in the pathophysiology of sepsis, particularly aiming to validate the histones as a biomarker, mediator and therapeutic target for severe sepsis and accompanying multiple organ dysfunction or failure (MODS/MOF). Severe sepsis is a major medical problem responsible for approximately 750,000 ICU admissions at a cost of over 17 billion dollars and 225,000 deaths in the U.S. annually. Our group has recently discovered that nuclear histones are released in the extracellular environment in response to inflammatory challenges and are important mediators of sepsis-induced organ failure and death. Histone plasma levels correlate with organ dysfunction and death in animals (mice and baboons), as well as in humans with sepsis. Xigris (activated protein C) cleaves histones and reduces their toxicity. Histone inhibition with antibodies or blocking peptides rescue mice from experimental lethal sepsis. The objectives of this proposal are: (i) to validate extracellular histones as important biomarkers that mediate of tissue damage, ultimately leading to organ failure, and (ii) characterize the therapeutic potential of two histone blocking strategies. Aim 1 employs exogenous histone challenge to characterize the in vivo cytotoxic, inflammatory and microthrombotic effects of histones and therapeutic targeting of histones in four mouse models of sepsis. Aim 2 will translate the histone inhibition approaches to a clinically relevant model of E. coli sepsis in a large animal. Aim 3. Will validate the plasma histones as a prognostic biomarker for organ dysfunction that correlates with clinical outcomes, and helps to identify the patients who will benefit from specific antisepsis therapies with histone blockade. Overall, this project will advance the understanding of the pathophysiology of sepsis induced organ damage, will validate new biomarkers and develop a novel potential treatment for patients with sepsis and MOF. PUBLIC HEALTH RELEVANCE: Sepsis is a multi-factorial disorder that triggers an uncontrolled inflammatory response, ultimately leading to multiple organ failure and death. We have evidence that during sepsis, histones are released in the extracellular environment and are mediators of organ dysfunction and lethality. The objectives of this proposal are to validate extracellular histones as an important cause and biomarker of tissue damage and to test two histone-blocking approaches as potential therapeutics in sepsis.