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.

败血症综合征和败血性休克是发病率和死亡率的重要原因 危重病人的死亡率。尽管技术和 随着重症监护的治疗进展，脓毒症仍然是关键 外科重症监护室 40% 至 60% 的死亡是由该因素造成的。败血症 每年有 500,000 名患者出现该综合征，是第 13 位最常见的综合征 造成美国约 100,000 人死亡 每年死亡人数。不幸的是，脓毒症综合征的发病率出现 全国范围内不断增加。很明显，替代方法 必须找到脓毒症的预防和/或治疗方法。近期临床 研究表明 (1->3)-β-D-葡聚糖可激活巨噬细胞 将显着降低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，抗菌功效 葡聚糖可以通过改变高级结构（即支化 频率和聚合度）的分子。研究 该提案中概述的内容将解决两个关键问题。一、有吗 (1->3)-β-D-葡聚糖的分子构象将发挥最佳作用 抗败血症功效？二.细胞和分子机制是什么 与葡聚糖诱导的败血症保护有关吗？我们将聘用 小鼠败血症盲肠结扎穿刺（CLP）模型 败血性休克。鉴定 (1->3)-β-D-葡聚糖聚合物 显着的抗脓毒活性，我们将进行结构/活动 关系研究以确定是否改变分子 构象、侧链支化频率和/或聚合物尺寸将 增强小鼠 CLP 模型中的抗败血症功效。当 (1->3)- β-D-葡聚糖具有最佳的抗败血症活性 确定后，我们将开发该聚合物的分子模型。我们将 检查 (1->3)-β-D-葡聚糖的细胞和分子机制 通过确定脓毒症； i) 葡聚糖与巨噬细胞的结合是否涉及 特定受体以及脓毒症对葡聚糖巨噬细胞受体的影响 绑定； ii) 葡聚糖和/或败血症对巨噬细胞信号的影响 转导途径。此外，我们还将进行系统性的比较和对比 以及巨噬细胞 TNFα、IL-1β、IL-6 和一氧化氮水平 葡聚糖的存在和不存在以及败血症。我们也会比较和 对比巨噬细胞 TNFα、IL-1β、IL-6、IL-8 和诱导型硝酸盐 氧化物合酶基因的转录、翻译和精化 葡聚糖的存在和不存在以及败血症。将特别强调 在检查 TNFα 时，因为葡聚糖可能会抑制 通过下调巨噬细胞 TNFα 的释放来治疗脓毒症后遗症。长- 这项研究的目标是了解其机制 葡聚糖可改善败血症和败血性休克。这些数据最终可能会导致 为患者制定更好的管理策略 易患败血症和败血性休克。