ACTIONS AND INTERACTIONS OF UVEITIC MEDIATORS

葡萄膜炎介质的作用和相互作用

• 批准号: 3266020
• 负责人: LLOYD N FLEISHER
• 金额: $ 14.97万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3266020
• 关键词: G protein; adenylate cyclase; arachidonate; chromatography; cyclic AMP; cyclic nucleoside monophosphate; eicosanoid metabolism; eicosanoids; interleukin 1; iris; laboratory rabbit; lipoxygenase; membrane permeability; naproxen; neoplastic cell culture for noncancer research; oxidoreductase inhibitor; pathologic process; pertussis toxin; platelet activating factor; prostaglandin endoperoxide synthase; protein kinase C; radioimmunoassay; second messengers; spectrometry; tumor necrosis factor alpha; uvea ciliary body; uveitis

Treating ocular inflammation (uveitis) has proven a difficult task, due at least in part to the numerous mediators involved and an inadequate understanding of its regulation. Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are two functionally related cytokines with potent inflammatory effects outside the eye and recently-demonstrated phlogistic effects in the eye. We suggest that TNF and IL-1 are key mediators of uveitis by virtue of their effects on uveal tissue via two distinct mechanisms: 1) They provoke secondary release of eicosanoids (metabolites of arachidonic acid) and platelet-activating factors (PAF); 2) They interact directly with uveal cells, affecting cellular levels of cyclic nucleotides through specific binding to cell surface-"G" protein-linked receptors. Part I of this hypothesis will be addressed by injecting TNF and IL-1 into the vitreal chamber of the rabbit eye and characterizing their effects in terms of dose-response, time course and cytokine levels and interactions. Eicosanoid contributions will be assessed by determining those that increase during cytokine-induced uveitis and then measuring the ability of cyclooxygenase (indomethacin, naproxen) and combined cyclooxygenase/lipoxygenase (SK&F 86002) inhibitors to alter cytokine- induced effects. PAF will be measured in aqueous humor extracts by release of [3H]-serotonin from platelets and its role in cytokine-induced uveitis assessed by determining the effect of a specific PAF receptor antagonist (SRI 63-441) and the ability of intravitreally-injected PAF and PAF/eicosanoid combinations (those which increase during cytokine-induced uveitis) to reproduce the effects of combinations (those which increase during cytokine-induced uveitis) to reproduce the effects of intravitreally-injected cytokines. In part II of this hypothesis the ability of cytokines, in vitro, to induce adenosine 3',5'-cyclic monophosphate (cAMP) production by individual preparations of iris, ciliary body and ciliary processes, and the ability of agents that influence adenylate cyclase activity to alter cytokine-induced cAMP production, in vitro, will be measured. These agents include Gs protein activators (F-; guanosine 5'-[beta, g-imino]triphosphate), a Gi inhibitor (pertussis toxin), protein kinase C (PKC) activators (4beta-phorbol 12-myristate 13- acetate) and inhibitors (H7; staurosporin) and adenylate cyclase activators (forskolin; Mn2+). These studies will provide valuable insight into the mechanisms by which TNF and IL-1 regulate production of the secondary messenger, cAMP, and pivotal substance controlling membrane permeability and aqueous humor production. It is important that the ocular effects of TNF and IL-1, the specific substances secondarily mediating these effects, and the influence of these cytokines on uveal cyclic nucleotide production be elucidated since new pharmacological modalities will soon be available for possible use in the treatment of uveitis.

治疗眼部炎症（葡萄膜炎）已被证明是一项艰巨的任务，因为 至少部分是由于涉及的调解员众多且调解员不足 了解其监管。 肿瘤坏死因子（TNF）和 白细胞介素-1 (IL-1) 是两种功能相关的细胞因子，具有强效作用 眼外炎症反应和最近出现的炎症 对眼睛的影响。 我们认为 TNF 和 IL-1 是 葡萄膜炎是由于它们通过两种不同的方式对葡萄膜组织产生影响 机制：1）它们引起类二十烷酸（代谢物）的二次释放 花生四烯酸）和血小板激活因子（PAF）； 2）他们 直接与葡萄膜细胞相互作用，影响循环细胞水平 核苷酸通过特异性结合到细胞表面-“G”蛋白连接 受体。 该假设的第一部分将通过注射 TNF 来解决 和 IL-1 进入兔眼玻璃体腔并表征 它们在剂量反应、时间进程和细胞因子水平方面的影响 和互动。 类二十烷酸的贡献将通过确定 那些在细胞因子诱导的葡萄膜炎期间增加的值，然后测量 环加氧酶（吲哚美辛、萘普生）和联合酶的能力 环加氧酶/脂氧合酶 (SK&F 86002) 抑制剂可改变细胞因子- 诱发效应。 将通过释放来测量房水提取物中的 PAF 血小板中的[3H]-血清素及其在细胞因子诱导的葡萄膜炎中的作用 通过确定特定 PAF 受体拮抗剂的作用进行评估 (SRI 63-441) 以及玻璃体内注射 PAF 和 PAF/类二十烷酸组合（在细胞因子诱导期间增加的组合） 葡萄膜炎）以重现组合的效果（那些增加 在细胞因子诱导的葡萄膜炎期间）重现以下效果 玻璃体内注射细胞因子。 在这个假设的第二部分中 细胞因子在体外诱导腺苷 3',5'-环状的能力 通过虹膜、睫状体的单独制剂产生单磷酸盐（cAMP） 身体和纤毛过程，以及影响因素的能力 腺苷酸环化酶活性改变细胞因子诱导的 cAMP 产生， 体外，将进行测量。 这些试剂包括 Gs 蛋白激活剂（F-； 鸟苷 5'-β, g-亚氨基]三磷酸），一种 Gi 抑制剂（百日咳 毒素）、蛋白激酶 C (PKC) 激活剂（4β-佛波醇 12-肉豆蔻酸酯 13- 乙酸盐）和抑制剂（H7；十字孢菌素）和腺苷酸环化酶激活剂 （毛喉素；Mn2+）。 这些研究将为我们提供宝贵的见解 TNF 和 IL-1 调节次级细胞产生的机制 信使、cAMP 和控制膜通透性的关键物质 和房水的产生。 重要的是对眼部的影响 TNF 和 IL-1 是介导这些作用的特定物质， 以及这些细胞因子对葡萄膜环核苷酸产生的影响 由于新的药理学方式很快就会被阐明 可能用于治疗葡萄膜炎。