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）：在此提案中要检验的假设是，糖皮质激素（GC）对控制脂多多亚酸（LPS）诱导的单核细胞/巨噬细胞（MOMAC）激活计划的关键成分的控制产生了双相影响。 PI和CO-I提出了一个模型，以调和中等皮质醇水平的刺激性（“允许”）作用与高皮质醇水平的抑制作用。该模型预测了钟形曲线，可用于皮质醇对昼夜皮质醇变化上层或附近峰值的炎症介质的影响。由于GC的允许作用不及抑制作用，因此它们提供了我们提出的对MOMAC激活的介体和调节剂的研究的重点。具体目的是：（1）测试GC对响应LPS的细胞因子产生和MOMAC表型产生双相影响的假设，以及（2）阐明GC对MOMAC激活程序的允许和抑制作用的分子机制。我们建议解决使用体外和人体体内系统的这些问题。最初，我们将使用REATRIATIAD MO的培养物，该培养物将在将皮质醇保持在预测的水平上，该水平将其接触到LPS。我们将使用ELISA和流式细胞仪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和皮质醇在剂量和时间上首先确定的时间最大程度地增强或抑制CD 163和IL-6，我们将检查其他细胞因子，信号分子和受体已被LPS诱导或抑制的受体。我们还将使用人类实验性内毒素血症的良好控制范式来阐明生理和分子机制，这些机制导致GC在体内对内毒素反应期间抑制或增强了假定的促促促疾病和抗炎分子的产生和作用。我们认为，这些研究将对GC既增强和抑制免疫和炎症功能的机制产生重要的见解，从而导致更有效的方法在炎症的临床环境中使用。