The role of Sphingosine Kinase 1 in a Mouse Model of Chronic Inflammation

鞘氨醇激酶 1 在慢性炎症小鼠模型中的作用

• 批准号: 7678750
• 负责人: DeAnna Baker Frost
• 金额: $ 3.69万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7678750
• 关键词: Affect; Anti-Inflammatory Agents; Anti-inflammatory; Area; Arthritis; Autoimmune Diseases; Cell membrane; Cells; Chronic; Clinical; Dinoprostone; Disease; Disease Progression; Enzymes; Excision; Fibroblasts; Gene Expression; Goals; Human; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Investigation; Joints; Lead; Link; Literature; Mediating; Medicine; Methodology; Mus; Necrosis; PTGS2 gene; Pathogenesis; Pathway interactions; Patients; Production; Proteins; Rheumatoid Arthritis; Role; SPHK1 enzyme; Severities; Small Interfering RNA; Sphingolipids; Stress; TNF gene; Testing; Tissues; Transgenic Mice; Tumor Necrosis Factor-alpha; Work; arthritis therapy; cyclooxygenase 2; cytokine; human TNF protein; in vivo; knock-down; mouse model; new therapeutic target; novel; sphingosine 1-phosphate; tumor

DESCRIPTION (provided by applicant): Project Summary: Rheumatoid Arthritis (RA) is an autoimmune disease that affects people world wide. The underlying mechanism is unknown, but patients tend to have high levels of tumor necrosis alpha (TNF) in their joints. TNF helps protect the body when under stress, but it can also be damaging to un-infected cells and the surrounding tissue by causing inflammation leading to production of harmful proteins and destruction of non-inflammed areas. Despite advances in medicine, anti-inflammatory therapies currently available are not totally effective and are often costly, thus, novel therapies are needed. Sphingolipids are found in the cell membrane but have also been shown to be involved in the cellular pathways that promote inflammation. One specific sphingolipid, sphingosine-1-phosphate (S1P), has been shown in the literature to cause an increase in inflammatory mediators. Addition of S1P leads to increased prostaglandin E2 (PGE2) and COX-2 protein. Simultaneous stimulation with TNF and S1P increases PGE2 and COX-2 more than S1P alone. Therefore, decreased formation of S1P has been hypothesized to lead to decreases in inflammation. S1P is formed through the action of sphingosine kinase (SphK) 1 and 2; however SphK1 is the major enzyme responsible for S1P formation in the inflammatory pathway. Using siRNA to remove of SphK1 in fibroblast cells lead to decreases in S1P, COX-2, and PGE2 formation. The effects seen after TNF stimulation in these cells were removed with the elimination of SphK1 suggesting a relationship between TNF and SphK1. The goal of this project is to study the effects of SphK1 on inflammation in mice that over express human TNF, like RA patients, and do not have a working copy of the SphK1. In preliminary investigations, mice that are missing functional copies of SphK1 have decreased arthritis score despite the fact that TNF alpha is being expressed at constant levels. The aims of the study are 1) determine the contribution of sphingosine kinase 1 in the pathogenesis of TNF alpha induced arthritis in vivo; 2) characterize gene expression in joints from TNF alpha transgenic mice with and without functioning copies of SphK1; 3) determine the mechanism in which removal of SphK1 affects inflammation using FLS. The primary methodology of these studies will be to utilize the TNF/SphK1 mouse model to determine the mechanism of SphK1 affects inflammation. Relevance: This project seeks to define the significance of TNF alpha and SphK1 in chronic inflammation, potentially leading to the discovery of a novel therapeutic target for chronic inflammatory diseases like RA.

描述（由申请人提供）： 项目摘要：类风湿性关节炎 (RA) 是一种影响全世界人民的自身免疫性疾病。其潜在机制尚不清楚，但患者的关节中往往存在高水平的肿瘤坏死因子 α (TNF)。 TNF 有助于在压力下保护身体，但它也可能通过引起炎症而损害未感染的细胞和周围组织，从而导致有害蛋白质的产生和非发炎区域的破坏。尽管医学取得了进步，但目前可用的抗炎疗法并不完全有效，而且往往成本高昂，因此需要新的疗法。鞘脂存在于细胞膜中，但也被证明参与促进炎症的细胞途径。文献表明，一种特定的鞘脂，1-磷酸鞘氨醇 (S1P)，会导致炎症介质增加。添加 S1P 会导致前列腺素 E2 (PGE2) 和 COX-2 蛋白增加。 TNF 和 S1P 同时刺激比单独使用 S1P 更能增加 PGE2 和 COX-2。因此，假设 S1P 形成减少会导致炎症减少。 S1P是通过鞘氨醇激酶（SphK）1和2的作用形成的；然而，SphK1 是炎症途径中负责 S1P 形成的主要酶。使用 siRNA 去除成纤维细胞中的 SphK1 会导致 S1P、COX-2 和 PGE2 形成减少。 TNF 刺激这些细胞后所观察到的效应随着 SphK1 的消除而消失，这表明 TNF 和 SphK1 之间存在关系。该项目的目标是研究 SphK1 对过度表达人类 TNF 的小鼠（如 RA 患者）炎症的影响，并且没有 SphK1 的工作副本。在初步研究中，尽管 TNF α 的表达水平恒定，但缺失 SphK1 功能性拷贝的小鼠关节炎评分却有所下降。该研究的目的是1）确定鞘氨醇激酶1在体内TNFα诱导的关节炎发病机制中的作用； 2) 表征具有或不具有功能性 SphK1 拷贝的 TNF α 转基因小鼠关节中的基因表达； 3) 使用 FLS 确定去除 SphK1 影响炎症的机制。这些研究的主要方法是利用 TNF/SphK1 小鼠模型来确定 SphK1 影响炎症的机制。相关性：该项目旨在明确 TNF α 和 SphK1 在慢性炎症中的重要性，从而有可能发现 RA 等慢性炎症性疾病的新治疗靶点。