AMELIORATION OF SEPSIS BY MACROPHAGE ACTIVATION

通过巨噬细胞激活改善脓毒症

• 批准号: 2685082
• 负责人: David L. Williams
• 金额: $ 16.64万
• 依托单位: EAST TENNESSEE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2685082
• 关键词: antisepsis; biological signal transduction; cellular pathology; chemical binding; chemical models; conformation; gene expression; genetic transcription; genetic translation; glucans; interleukin 1; interleukin 6; laboratory mouse; leukocyte activation /transformation; macrophage; model design /development; molecular pathology; nitric oxide; nitric oxide synthase; northern blottings; polymers; receptor binding; septic shock; tissue /cell culture; tumor necrosis factor alpha

Sepsis syndrome and septic shock are significant causes of morbidity and mortality in critically ill patients. Despite technological and therapeutic advances in critical care, sepsis continues to be a pivotal factor in 40% to 60% of deaths in surgical intensive care units. Sepsis syndrome occurs in 500,000 patients per year and is the 13th most common cause of death in the United States, resulting in an estimated 100,000 deaths per year. Unfortunately, the incidence of sepsis syndrome appears to be increasing nationwide. It is clear that alternative approaches to the prevention and/or management of sepsis must be found. Recent clinical studies indicate that macrophage activation with (1->3)-beta-D-glucans will significantly reduce septic morbidity and mortality in surgical patients. Our preliminary studies indicate that the antisepsis efficacy of glucans can be enhanced by altering the higher structure (i.e. branching frequency and degree of polymerization) of the molecule. The research outlined in this proposal will address two critical questions. I. Is there a molecular conformation of(1->3)-beta-D-glucan that will exert optimal anti-sepsis efficacy? II. What are the cellular and molecular mechanisms associated with glucan induced protection against sepsis? We will employ the murine cecal-ligation and puncture (CLP) model of septicemia and septic shock. To identify the (1->3)-beta-D-glucan polymer with the most significant anti-sepsis activity, we will conduct structure/activity relationship studies to determine whether altering the molecular conformation, side-chain branching frequency and/or polymer size will enhance anti-sepsis efficacy in the murine CLP model. When the (1->3)- beta-D-glucan that exerts optimal anti-sepsis activity has been identified, we will develop a molecular model of the polymer. We will examine the cellular and molecular mechanisms of (1->3)-beta-D-glucan in sepsis by determining; i) whether glucan binding to macrophages involves a specific receptor and the effect of sepsis on glucan-macrophage receptor binding; and ii) the effect of glucan and/or sepsis on macrophage signal transduction pathways. In addition, we will compare and contrast systemic and macrophage TNFalpha, IL-1beta, IL-6 and nitric oxide levels in the presence and absence of glucan and sepsis. We will also compare and contrast macrophage TNFalpha, IL-1beta, IL-6, IL-8 and inducible nitric oxide synthase gene transcription, translation and elaboration in the presence and absence of glucan and sepsis. Special emphasis will be placed on examination of TNFalpha, since glucans may inhibit the development of septic sequelae by down-regulating macrophage TNFalpha release. The long- range goal of this research is to understand the mechanism(s) by which glucans ameliorate sepsis and septic shock. These data may ultimately lead to the development of better management strategies for patients predisposed to sepsis and septic shock.

脓毒症综合征和脓毒性休克是发病的重要原因， 重症患者的死亡率。尽管技术和 在重症监护的治疗进展，脓毒症仍然是一个关键的 外科重症监护病房中40%至60%的死亡原因。败血症 每年有500，000名患者发生，是第13位最常见的 在美国的死亡原因，导致估计100，000 死亡人数。不幸的是，败血症综合征的发病率似乎 在全国范围内增加。很明显， 必须找到脓毒症的预防和/或管理。 研究表明，用（1->3）-β-D-葡聚糖激活巨噬细胞 将显著降低外科手术中脓毒症的发病率和死亡率， 患者我们的初步研究表明， 葡聚糖可以通过改变高级结构（即分支 频率和聚合度）。研究 本提案概述的内容将涉及两个关键问题。I.有没有 （1->3）-β-D-葡聚糖的分子构象， 抗菌功效？二.细胞和分子机制是什么 与葡聚糖诱导的脓毒症保护有关吗？我们会委聘 小鼠盲肠结扎穿孔（CLP）败血症模型， 败血性休克为了鉴定（1->3）-β-D-葡聚糖聚合物， 重要的抗菌活性，我们将进行结构/活动 关系研究，以确定是否改变分子 构象、侧链分支频率和/或聚合物尺寸将 增强在鼠CLP模型中的抗菌效力。当（1->3）- 发挥最佳抗菌活性的β-D-葡聚糖已被 确定，我们将开发一个聚合物的分子模型。我们将 研究（1->3）-β-D-葡聚糖在 脓毒症通过确定; i）葡聚糖与巨噬细胞的结合是否涉及 一种特异性受体及脓毒症对巨噬细胞葡聚糖受体的影响 结合;和ii）葡聚糖和/或脓毒症对巨噬细胞信号的影响 转导途径。此外，我们将比较和对比系统 和巨噬细胞TNF α、IL-1 β、IL-6和一氧化氮水平 存在和不存在葡聚糖和败血症。我们也会比较， 对比巨噬细胞TNF α、IL-1 β、IL-6、IL-8和诱导型一氧化氮 氧化物合酶基因的转录、翻译和加工 存在和不存在葡聚糖和败血症。将特别强调 在检查TNF α时，由于葡聚糖可以抑制 通过下调巨噬细胞TNF α的释放来治疗败血症后遗症。很长的- 本研究的范围目标是了解 葡聚糖改善脓毒症和脓毒性休克。这些数据可能最终导致 为患者制定更好的管理策略 易患败血症和感染性休克