Pathogenic Role of Malondialdehyde-Acetaldehyde Adducts in Rheumatoid Arthritis

丙二醛-乙醛加合物在类风湿性关节炎中的致病作用

• 批准号: 10045500
• 负责人: TED RICHARD MIKULS
• 金额: --
• 依托单位: OMAHA VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10045500
• 关键词: Acetaldehyde; Adjuvant; Affect; Age; Aging; Antibodies; Antigens; Arginine deiminase; Arthritis; Attenuated; Autoantibodies; Autoimmune Responses; Autoimmunity; Binding; Biological; Bypass; Calcium; Carrier Proteins; Cell Line; Cells; Characteristics; Chinese Hamster Ovary Cell; Citrulline; Data; Development; Diagnosis; Dihydropyridines; Disease; Disease Progression; Epitopes; Event; Fibrosis; Frequencies; Future; General Population; Healthcare; Human; Immune; Immune response; Immunization; Immunologic Adjuvants; Immunologics; In Vitro; Individual; Inflammation; Inflammatory; Inflammatory Response; Joints; Laboratories; Lead; Link; Lipid Peroxidation; MHC Class II Genes; Malondialdehyde; Mediating; Modification; Morbidity - disease rate; Mus; Outcome; Oxidative Stress; Pathogenesis; Pathogenicity; Patients; Peptides; Play; Post-Translational Protein Processing; Prevention; Process; Prognosis; Proteins; Reporting; Research; Rheumatoid Arthritis; Role; Sampling; Seminal; Signal Transduction; Structure; Synovial Cell; Synovial Membrane; T cell response; Time; Tissues; Veterans; Woman; Work; adaptive immune response; adduct; base; cell type; chelation; citrullinated protein; cytotoxic; design; disability; experience; experimental study; immunogenic; improved; in vivo; inhibitor/antagonist; innovation; insight; joint destruction; mRNA Expression; male; men; military veteran; mortality; mortality risk; neoantigens; novel marker; novel strategies; receptor; receptor binding; response; rheumatologist; scavenger receptor; seropositive; societal costs; systemic autoimmune disease; uptake

It has been estimated that rheumatologist-diagnosed Rheumatoid arthritis (RA) is seen in up to 2% of the users of VA healthcare. Moreover, compared to RA in women, RA in men (the primary VA demographic) leads to greater morbidity, a higher frequency of extra-articular manifestations, and worse disease-related outcomes. With an aging and predominantly male veteran population, it is anticipated that the burden posed by RA will grow dramatically in the VA in coming years. This is highly relevant given the association of RA with; substantially higher mortality risk among veterans, in addition to high rates of work-related disability, and annual societal costs approaching $40 billion in the US alone. Over the past few years, there have been substantial advances in our understanding of RA pathogenesis. Anti-citrullinated protein antibody (ACPA) is highly specific to RA with recent studies suggesting that ACPA are pathogenic with seropositivity portending a poor prognosis including more rapid joint destruction. However, the mechanism(s) by which citrullinated proteins/ peptides are recognized and processed and presented in the context of co-stimulatory molecules is still not well understood. Studies have shown that a unique post-translational modification of proteins that occurs under oxidative stress by malondialdehyde (MDA) and acetaldehyde (AA), termed MAA, up- regulates MHC Class II, increases co-stimulatory molecules and generates cytotoxic and pro-inflammatory responses in the absence of exogenous adjuvant. For the first time, our group has shown that MAA modified proteins are detected in synovial tissues of RA patients and co-localize with citrullinated antigen. Additionally, anti-MAA antibody isotypes are independently associated with ACPA concentration (p < 0.0001) in patients with established RA. Therefore, our overarching hypothesis is that these two post-translational modifications (MAA modification and citrullination) act in concert to drive tolerance loss resulting in the anti-citrulline autoimmune responses characteristic of RA. To investigate this hypothesis, studies in Aim 1 will evaluate adaptive immune responses (autoantibody and T cell responses) to citrullinated and/or MAA-modified proteins. We anticipate that compared to antigens that are only citrullinated or only MAA modified, immune responses to co-modified proteins will be higher in mice following immunization and in RA patients. As prior data has demonstrated that SRs mediate the biological effects of MAA-modified proteins on APCs and other cells, Aim 2 is designed to identify the specific SRs that mediate the effects of citrullinated and/or MAA-modified proteins in RA. In Sub-Aim #1, studies will leverage Chinese Hamster Ovary (CHO) cell lines that are already available in our laboratory and that have been transfected with each of the various SRs. Results of initial experiments will inform the design of subsequent binding studies using human APCs (that simultaneously express multiple SRs) and cell types unique to synovial tissue. Using available SR inhibitors alone or in combination will aid in defining which receptors are found on each cell type. In Sub-Aim #2, will focus on the biological effects (fibrosis, inflammation, calcium influx, PAD expression and citrullination) of the binding of MAA modified and/or citrullinated proteins to the different cell types. Thus, the innovative aspect of this proposal is its focus on the melding of two naturally occurring biological events (citrullination and oxidative stress) that conspire to initiate highly specific autoimmune responses, promoting the development and progression of RA.

据估计，经风湿病专家诊断的类风湿性关节炎 (RA) 的患病率高达 2% VA 医疗保健的用户。此外，与女性 RA 相比，男性 RA（主要 VA 人群） 导致更高的发病率、更高频率的关节外表现以及更严重的疾病相关症状 结果。随着退伍军人人口老龄化且以男性为主，预计退伍军人所带来的负担 未来几年，RA 将在 VA 中急剧增长。鉴于 RA 与以下因素的关联，这是高度相关的： 退伍军人的死亡风险显着升高，此外，与工作相关的残疾率很高，每年的死亡率也很高。 仅在美国，社会成本就接近 400 亿美元。在过去的几年里，已经发生了大量的 我们对 RA 发病机制的理解取得了进展。抗瓜氨酸蛋白抗体 (ACPA) 具有高度特异性 最近的研究表明 ACPA 具有致病性，血清阳性预示着 RA 的患病率较差 预后包括更快速的关节破坏。然而，瓜氨酸蛋白/ 肽在共刺激分子的背景下被识别、加工和呈递仍然没有 很好理解。研究表明，蛋白质的独特翻译后修饰 在丙二醛（MDA）和乙醛（AA）的氧化应激下发生，称为MAA，up- 调节 MHC II 类，增加共刺激分子并产生细胞毒性和促炎性 在没有外源佐剂的情况下的反应。我们小组首次证明 MAA 修改了 在 RA 患者的滑膜组织中检测到蛋白质，并与瓜氨酸抗原共定位。此外， 抗 MAA 抗体同种型与患者的 ACPA 浓度独立相关 (p < 0.0001) 已建立 RA。因此，我们的总体假设是这两个翻译后 修饰（MAA 修饰和瓜氨酸化）协同作用，导致耐受性损失，导致 RA 的抗瓜氨酸自身免疫反应特征。为了研究这一假设，研究人员 目标 1 将评估对瓜氨酸和/或的适应性免疫反应（自身抗体和 T 细胞反应） MAA 修饰的蛋白质。我们预计，与仅瓜氨酸化或仅 MAA 的抗原相比 免疫后小鼠和 RA 中对共修饰蛋白的免疫反应会更高 患者。先前的数据表明 SR 介导 MAA 修饰蛋白的生物效应 在 APC 和其他细胞上，目标 2 旨在识别介导以下作用的特定 SR： RA 中的瓜氨酸化和/或 MAA 修饰的蛋白质。在子目标#1中，研究将利用中国仓鼠 我们实验室已有且已转染的卵巢 (CHO) 细胞系 每个不同的 SR。初始实验的结果将为后续结合研究的设计提供信息 使用人类 APC（同时表达多个 SR）和滑膜组织特有的细胞类型。使用 可用的 SR 抑制剂单独或组合将有助于确定每个细胞上发现的受体 类型。在子目标 #2 中，将重点关注生物效应（纤维化、炎症、钙流入、PAD MAA 修饰和/或瓜氨酸化蛋白与不同细胞的结合 类型。因此，该提案的创新之处在于其重点是两种自然发生的生物物质的融合 共同引发高度特异性自身免疫反应的事件（瓜氨酸化和氧化应激）， 促进RA的发生和进展。