ACTIONS AND INTERACTIONS OF UVEITIC MEDIATORS

葡萄膜炎介质的作用和相互作用

• 批准号: 3266019
• 负责人: LLOYD N FLEISHER
• 金额: $ 10.83万
• 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/3266019
• 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; 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，应在 至少在一定程度上是因为涉及的调解人众多，而且 对其规则的理解。肿瘤坏死因子(TNF)和 白介素1(IL-1)是两种功能相关的细胞因子，具有很强的 眼外炎症效应和最近表现出的炎症 对眼睛的影响。我们认为，肿瘤坏死因子和白介素1是主要的介导物。 葡萄膜炎通过两种不同的方式对葡萄膜组织产生影响 机制：1)它们引起二十烷类化合物(代谢物)的二次释放 花生四烯酸)和血小板活化因子(PAF)； 直接与葡萄膜细胞相互作用，影响细胞水平的周期 通过与细胞表面特异性结合的核苷酸-“G”蛋白连接 感受器。这一假说的第一部分将通过注射肿瘤坏死因子来解决 和IL-1注入兔眼玻璃体腔的实验研究 它们在剂量-反应、时间进程和细胞因子水平方面的作用 和互动。二十烷类化合物的贡献将通过确定 在细胞因子诱导的葡萄膜炎期间增加，然后测量 环氧合酶(消炎痛、萘普生)及其联合应用能力 环氧合酶/脂氧合酶(SK&F 86002)抑制剂改变细胞因子- 诱导效应。PAF将通过释放的方式在房水提取物中进行测量 血小板5-羟色胺的表达及其在细胞因子诱导的葡萄膜炎中的作用 通过测定一种特定的PAF受体拮抗剂的效果进行评估 (SRI 63-441)和玻璃体内注射PAF和 PAF/二十烷类化合物(在细胞因子诱导过程中增加的那些 葡萄膜炎)，以复制组合的效果(那些增加 在细胞因子诱导的葡萄膜炎期间)以重现 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’-环化的能力 虹膜、睫状体个别制剂生产一磷酸(CAMP) 身体和睫状突，以及影响 腺苷环化酶活性改变细胞因子诱导的cAMP产生 在体外，将被测量。这些药物包括Gs蛋白激活剂(F-； 鸟苷5‘-[β，g-亚氨基]三磷酸)，一种胃肠道抑制物(百日咳 毒素)、蛋白激酶C(PKC)激活剂(4β-佛波醇12-肉豆蔻酸盐13- 醋酸盐)和抑制剂(H7；星孢菌素)和腺苷环化酶激活剂 (Forskolin；Mn2+)。这些研究将提供有价值的洞察 肿瘤坏死因子和白介素1调节补体生成的机制 信使、cAMP和控制膜通透性的关键物质 和房水的制作。很重要的一点是， 肿瘤坏死因子和白介素1这两种辅助调节这些效应的特定物质， 以及这些细胞因子对葡萄膜环核苷酸产生的影响 由于新的药理方法即将问世，因此需要澄清 可能用于葡萄膜炎的治疗。