Glucocorticoid/cytokine mechanisms in endotoxemia.

内毒素血症中的糖皮质激素/细胞因子机制。

• 批准号: 6872467
• 负责人: PAUL GUYRE
• 金额: $ 39.5万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6872467
• 关键词: CD antigens; I kappa B beta; autoimmunity; clinical research; corticosteroid receptors; cortisol; cytokine; endotoxins; enzyme linked immunosorbent assay; flow cytometry; glucocorticoids; hormone regulation /control mechanism; human tissue; immunologic assay /test; interleukin 6; leukocyte activation /transformation; lipopolysaccharides; luciferin monooxygenase; macrophage; messenger RNA; monocyte; nuclear factor kappa beta; polymerase chain reaction; receptor expression; septicemia; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): The hypothesis to be tested in this proposal is that glucocorticoids (GC) exert a biphasic effect on the control of key components of the lipopolysaccharride (LPS)-induced monocyte/ macrophage (MOMac) activation program. A model was proposed by the PI and Co-I to reconcile the stimulatory ("permissive") actions of moderate cortisol levels with the suppressive actions of high cortisol levels. This model predicts a bell-shaped curve for the effects of cortisol on inflammatory mediators that peaks at or near the upper levels of diurnal cortisol variation. As the permissive effects of GC are less well understood than the inhibitory actions, they provide the focus of our proposed studies on mediators and regulators of MOMac activation. The Specific Aims are: (1) To test the hypothesis that GC exert a biphasic influence on cytokine production and MOMac phenotype in response to LPS, and (2) To elucidate the molecular mechanisms of permissive and suppressive effects of GC on the MOMac activation program. We propose to address these questions employing both in vitro and human in vivo systems. Initially, we will use cultures of elutriated MO that will be exposed to LPS under conditions in which cortisol is maintained at levels predicted to be sub-permissive, permissive or suppressive. We will use ELISA and flow cytometric analyses to determine the interactive effects of cortisol and LPS on two key components of the MOMac activation program--IL-6 and CD163. Using LPS and cortisol at dosages and times that are first determined to result in maximal enhancement or inhibition of CD 163 and IL-6, we will examine additional cytokines, signaling molecules and receptors that have been shown to be induced or suppressed by LPS. We will also use a well-controlled paradigm of human experimental endotoxemia to elucidate the physiologic and molecular mechanisms that lead GC to either suppress or enhance the production and actions of putative pro- and anti-inflammatory molecules during the response to endotoxin in vivo. We believe that these studies will yield important insights into the mechanisms by which GC can both enhance and suppress immune and inflammatory functions, leading to more effective approaches to their use in clinical settings of inflammation.

描述（由申请人提供）：本提案中需要验证的假设是糖皮质激素（GC）对脂多糖（LPS）诱导的单核细胞/巨噬细胞（MOMac）激活程序的关键组分的控制具有双相作用。PI和Co-I提出了一个模型来调和中等皮质醇水平的刺激（“允许”）作用和高皮质醇水平的抑制作用。该模型预测了皮质醇对炎症介质影响的钟形曲线，该曲线在皮质醇日变化的最高水平或附近达到峰值。由于GC的允许作用比抑制作用更不为人所知，因此它们是我们提出的MOMac激活的介质和调节因子研究的重点。具体目的是：(1)验证LPS对细胞因子产生和MOMac表型双相影响的假设；(2)阐明GC对MOMac激活程序的允许和抑制作用的分子机制。我们建议利用体外和人体体内系统来解决这些问题。最初，我们将使用洗脱的MO培养物，在皮质醇维持在亚允许、允许或抑制水平的条件下，将其暴露于LPS。我们将使用ELISA和流式细胞术分析来确定皮质醇和LPS对MOMac激活程序的两个关键组成部分——IL-6和CD163的相互作用。使用LPS和皮质醇的剂量和时间，首先确定最大程度地增强或抑制CD 163和IL-6，我们将研究其他细胞因子、信号分子和受体，这些细胞因子已被证明是由LPS诱导或抑制的。我们还将使用一个控制良好的人类实验内毒素血症范例来阐明导致GC抑制或增强体内内毒素反应过程中推定的促炎和抗炎分子的产生和作用的生理和分子机制。我们相信这些研究将对GC增强和抑制免疫和炎症功能的机制产生重要的见解，从而为其在炎症的临床应用提供更有效的方法。