PREVENTION OF ARTHRITIS WITH DIETARY GLYCINE

用膳食甘氨酸预防关节炎

• 批准号: 6201494
• 负责人: RONALD G THURMAN
• 金额: $ 21.8万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6201494
• 关键词: arthritis; arthritis therapy; bacterial polysaccharides; calcium flux; chemoprevention; chloride channels; cytokine; diet therapy; dietary aminoacid; disease /disorder model; disease /disorder prevention /control; glycine; histopathology; inflammation; laboratory rat; macrophage; membrane potentials; nonhuman therapy evaluation; nuclear factor kappa beta; nutrition related tag; tumor necrosis factor alpha

Certain forms of inflammatory arthritis involve autoreactive immunologic processes (1-3), which are accompanied by an increase in the pivotal inflammatory cytokine, TNF-alpha. Our laboratory has shown that a diet rich in glycine can prevent increases in TNFalpha in several other models of inflammatory tissue injury. Thus, it is hypothesized that glycine will prevent arthritis by decreasing TNFalpha production by macrophages. In studies of liver injury, glycine blunted the LPS-induced increased in calcium and cytokines in Kupffer cells, a phenomenon which was blocked by strychnine and was dependent on chloride, just like the glycine-gated chloride channel in the CNS. In a initial series of proposed experiments, 4 groups of Lewis female rats (10 each) will be compared in a model of arthritis using bacterial group A steptococcal peptidoglycan- polysaccharide (PG-PS) (control, glycine 5%, PG-PS and glycine + PG-PS). In the acute phase of this model, inflammation peaks in 1-2 days after the i.a. injection of PG-PS and resolves in 3 weeks. Subsequent i.v. injections of PG-PS causes 100% reactivation of chronic inflammation. Food consumption, body weight, the arthritis index and ankle thickness will be monitored at 1-3 day intervals for 6 weeks. When maximal swelling occurs, rats will be sacrificed and joint tissue will be fixed for histological evaluation. We expect dietary glycine to minimize or prevent arthritis. Second, the dose-response for glycine in PG-PS induced arthritis will be determined. Dietary glycine will be varied (0% to 5%) and the parameters described above will be evaluated. In all groups, blood samples will be collected and serum glycine levels determined. We expect glycine to be protective in experimental arthritis in the 0.5-1.0 Mm range. Third, the ability of glycine to reverse arthritis will be evaluated. To test this unique idea, glycine or control diet will be initiated at the peak of inflammation and the time course of recovery will be evaluated. Fourth, to evaluate mechanism, splenic macrophages and blood lymphocytes will be isolated at the peaks of inflammation in the 4 groups detailed above. Changes in intracellular calcium, membrane potential and key cytokines (TNFalpha, IFNgamma, IL-2, IL-4 and IL-10) will be measured as well as the response to added PG-PS. The transcription factor NFkappaB will also be determined as it is pivotal in TNFalpha production. We expect that glycine will prevent arthritis b activating a strychnine sensitive glycine-gated chloride channel in macrophages and/or T-lymphocytes making them less responsive to inflammatory agonists. Collectively, we expect these studies to demonstrate that dietary glycine will block cytokine release, reduce inflammation and prevent arthritis. This work is timely and practical and will lead to simple, dietary interventions to prevent arthritis.

某些形式的炎性关节炎涉及自身反应性免疫 过程（1-3），这是伴随着增加的关键 炎性细胞因子TNF-α。我们的实验室已经证明， 富含甘氨酸可以防止其他几种模型中TNF α的增加 炎性组织损伤因此，假设甘氨酸将 通过减少巨噬细胞产生TNF α来预防关节炎。在 肝损伤的研究中，甘氨酸减弱了LPS诱导的肝细胞凋亡的增加。 Kupffer细胞中的钙和细胞因子，这一现象被 士的宁和依赖于氯，就像甘氨酸门控 氯离子通道。在最初的一系列实验中， 将在以下模型中比较4组刘易斯雌性大鼠（每组10只）： 关节炎使用细菌A组链球菌肽聚糖 多糖（PG-PS）（对照，甘氨酸5%，PG-PS和甘氨酸+ PG-PS）。 在该模型的急性期，炎症在施用后1-2天达到峰值。 I.A.注射PG-PS并在3周内消退。后续静脉注射 注射PG-PS导致慢性炎症100%再活化。食品 消耗，体重，关节炎指数和踝关节厚度将是 每隔1-3天监测6周。当最大肿胀发生时， 处死大鼠，固定关节组织进行组织学检查 评价我们希望饮食甘氨酸能减少或预防关节炎。 第二，甘氨酸在PG-PS诱导的关节炎中的剂量-反应将是： 测定饮食甘氨酸将变化（0%至5%），参数 将对上述内容进行评估。在所有组中，将采集血样， 收集并测定血清甘氨酸水平。我们希望甘氨酸 在0.5-1.0 μ m范围内对实验性关节炎有保护作用。三是 评价甘氨酸逆转关节炎的能力。为了验证这一 独特的想法，甘氨酸或控制饮食将开始在高峰期， 将评估炎症和恢复的时间过程。四是大力 评价机制，脾巨噬细胞和血淋巴细胞将被 在上述4组中的炎症高峰时分离。 细胞内钙、膜电位和关键细胞因子的变化 将测量TNF α、IFN γ、IL-2、IL-4和IL-10，以及 对加入PG-PS的反应。转录因子NF κ B也将被 因为它在TNF α产生中是关键的。我们认为甘氨酸 将防止关节炎B激活士的宁敏感甘氨酸门控 巨噬细胞和/或T淋巴细胞中的氯离子通道使它们减少 对炎症激动剂有反应。总的来说，我们希望这些研究 为了证明饮食甘氨酸会阻断细胞因子的释放， 炎症和预防关节炎。这项工作是及时和实际的， 将导致简单的饮食干预来预防关节炎。