Prostaglandin E synthase in rheumatoid arthritis

描述(由申请人提供)： 非类固醇抗炎药和特异性环氧合酶(COX)-2抑制剂治疗关节炎的有效性提供了临床证据，表明关节组织中前列腺素(PG)的产生增加导致疼痛、肿胀和僵硬的症状。PG的生物合成需要COX和PG合成酶的顺序作用。在促炎细胞因子的刺激下，包括滑膜成纤维细胞在内的许多不同类型的细胞中PGE2的表达优先增加。我们证明，人类原代滑膜细胞对促炎细胞因子的反应增加PGE2是由于微粒体前列腺素E合成酶(MPGES)-1的诱导。这项建议的总体目标是表征mPGES-1和其他PGE合成酶在免疫性炎症性关节炎中二十烷类生物合成中的作用。我们假设mPGES-1需要达到最大的PGE2产量，并且mPGES-1衍生的PGE2在形成免疫炎症反应中起作用。我们建议使用特定的COX酶抑制剂和抑制性RNA(RNAi)来确定mPGES-1相对于其他合成酶在人滑膜成纤维细胞中合成PGE2的特定作用。我们将研究环氧合酶-1、环氧合酶-2或mPGES-1缺陷小鼠细胞中二十烷类化合物的产生途径。将确定COX和PGES酶在关节炎或非关节炎受试者的滑膜组织中的表达及其相对亚细胞定位。此外，我们还将研究mPGES-1缺陷对基因缺失小鼠的先天免疫和获得性免疫的影响。我们将测定mPGES-1基因缺失小鼠巨噬细胞、脾细胞和树突状细胞的二十烷基类化合物和细胞因子谱。我们将确定mPGES-1缺乏对树突状细胞表型和功能的影响。我们将使用胶原诱导的关节炎和K/BxN血清模型来确定PGE2在关节炎免疫和炎症机制中的作用。这些数据将为确定mPGES-1是否是关节炎治疗干预的合适靶点提供科学基础。

DESCRIPTION (provided by applicant): The effectiveness of non-steroidal anti-inflammatory drugs and specific cyclooxygenase (COX)-2 inhibitors for treatment of arthritis provides clinical evidence that increased prostaglandin (PG) production in joint tissues contributes to symptoms of pain, swelling, and stiffness. PG biosynthesis requires the sequential action of COX and PG synthase enzymes. After stimulation with pro-inflammatory cytokines, there is a preferential increase in PGE2 in many different cell types, including synovial fibroblasts. We demonstrated that increased PGE2 in response to pro-inflammatory cytokines in human primary synovial cells is due to induction of microsomal PGE synthase (mPGES)-1. The overall goal of this proposal is to characterize the role of mPGES-1 and other PGE synthases in eicosanoid biosynthesis in immune inflammatory arthritis. We hypothesize a requirement for mPGES-1 to achieve maximal PGE2 production and a role for mPGES-1-derived PGE2 in shaping the immune inflammatory response. We propose to determine the specific role of mPGES-1 relative to other synthetic enzymes for biosynthesis of PGE2 in human synovial fibroblasts using specific COX enzyme inhibitors and inhibitory RNA (RNAi). We will investigate eicosanoid production pathways in cells from mice deficient for COX-1, COX-2 or mPGES-1. Expression of the COX and PGES enzymes in synovial tissues from patients with arthritis or non-arthritic subjects and their relative subcellular localization will be determined. In addition, we will examine the consequences of mPGES-1 deficiency for innate and acquired immunity in genetically null mice. We will determine eicosanoid and cytokine profiles of macrophages, splenocytes, and dendritic cells in mPGES-1 null mice. We will determine the impact of mPGES-1 deficiency on dendritic cell phenotype and function. We will determine the role of PGE2 on immune versus inflammatory mechanisms of arthritis using the collagen-induced arthritis and K/BxN serum models. These data will provide the scientific basis by which to determine if mPGES-1 is an appropriate target for therapeutic intervention in arthritis.