The role of peroxidasin in Goodpasture's disease

过氧化物酶在古德帕斯彻氏病中的作用

• 批准号: 9066686
• 负责人: Abraham Scott McCall
• 金额: $ 4.74万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2017-05-12
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9066686
• 关键词: Achievement; Affect; Affinity Chromatography; Anabolism; Antibodies; Appearance; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Basement membrane; Binding; Biochemical; Biological Assay; Cell Culture Techniques; Cessation of life; Characteristics; Clinical; Collaborations; Collagen Type IV; Complex; Data; Department of Defense; Disease; Early Diagnosis; Enzymes; Epitope Mapping; Glomerular basement membrane antibody; Health; Hydrogen Peroxide; Immunization; Interferometry; Kinetics; Lead; Letters; Link; Lung; Mass Spectrum Analysis; Mission; Modeling; Nature; Normal tissue morphology; Nucleotides; Oxidants; Oxidative Stress; PRTN3 gene; Pathogenesis; Patients; Peptide Fragments; Peroxidases; Physiological; Pilot Projects; Play; Proteolysis; Public Health; Research; Role; Sampling; Serum; Source; Specificity; Techniques; Testing; Time; Tissues; Work; base; chemical bond; cofactor; crosslink; domain mapping; eosinophil peroxidase; extracellular; glomerular basement membrane; grasp; human disease; hypobromous acid; in vivo; inhibiting antibody; insight; meetings; novel; oxidation; peroxidasin; prevent; repository; temporal measurement; tissue culture

DESCRIPTION (provided by applicant): Goodpasture's (GP) disease is an autoimmune disorder which affects the glomerular basement membrane (GBM) and pulmonary vasculature resulting in death for 50% of cases. In GP disease, antibodies specifically target the non-collagenous 1 (NC1) domain of the �3 and 5 chains of the collagen IV network. The NC1 domain occurs as hexamers that are covalently crosslinked by a sulfilimine chemical bond (-S=N-), which renders the NC1 hexamer inert to binding of GP autoantibodies. This bond is formed by the recently identified enzyme peroxidasin (PXDN) which putatively utilizes hydrogen peroxide as an initial oxidant to form hypobromous acid (HOBr) as the terminal oxidant for S=N bond formation. The highly reactive nature of HOBr suggests that peroxidasin complexes with the NC1 domain in vivo to maximize the potential efficiency of S=N bond formation and decrease collateral oxidative stress on the surrounding tissue. The pathogenesis of Goodpasture's disease may involve the disruption of PXDN function and normal cross-linking which would lead to proteolysis and self-immunization with auto-antigenic peptide fragments. The objective of this particular proposal is to determine peroxidasin's role in the pathogenesis of Goodpasture's disease. My pilot data has revealed novel anti-PXDN antibodies in GP patients which inhibit S=N bond formation. Additionally, I have found that PXDN can form the S=N bond using nucleotide monophosphates for oxidation rather than hydrogen peroxide (H2O2). These findings lead to the central hypothesis that anti-peroxidasin antibodies play a key role in the pathogenesis of GP disease by preventing the formation of the sulfilimine bond. This hypothesis will be interrogated with three specific aims: Aim 1: To characterize anti-peroxidasin antibodies in Goodpasture's patients. I have identified Goodpasture's patients who have anti-peroxidasin antibodies. We hypothesize that anti-peroxidasin antibodies target the peroxidase domain and inactivate S=N bond forming activity. Aim 2: To determine the time course of appearance and binding characteristics of anti-peroxidasin antibodies in Goodpasture's disease patients. Serial serum samples from 30 patients before the appearance of Goodpasture's disease will give temporal resolution to anti-PXDN antibodies. We hypothesize that anti-peroxidasin antibodies play a causal role in Goodpasture's disease. Aim 3: To identify the initial oxidant source used to form the S=N bond by peroxidasin. Hydrogen peroxide is the putative oxidant for peroxidasin but preliminary data shows that PXDN is capable of using nucleotide monophosphates as the initial oxidant for S=N bond formation. We hypothesize peroxidasin uses O2 and extracellular nucleotides as initial oxidants to form HOBr for the biosynthesis of the S=N bond. The achievement of these aims will provide insight into a novel mechanism of autoimmune disease pathogenesis and potentially enable early diagnosis of GP disease through understanding the inhibition of an unprecedented enzymatic mechanism in tissue biosynthesis.

描述（由申请人提供）：古德帕斯彻 (GP) 病是一种自身免疫性疾病，影响肾小球基底膜 (GBM) 和肺血管系统，导致 50% 的病例死亡。在 GP 病中，抗体专门针对非胶原蛋白 1 (。 IV 型胶原蛋白网络的 3 和 5 链的 NC1) 结构域 NC1 结构域以六聚体形式存在，通过共价交联。硫亚胺化学键 (-S=N-)，使 NC1 六聚体对 GP 自身抗体的结合呈惰性。该键是由最近发现的过氧化酶 (PXDN) 形成的，该酶可能利用过氧化氢作为初始氧化剂来形成次溴酸。 HOBr) 作为 S=N 键形成的末端氧化剂 HOBr 的高反应性表明过氧化物酶在体内与 NC1 结构域形成复合物。最大限度地提高 S=N 键形成的潜在效率并减少周围组织的附带氧化应激 Goodpasture 病的发病机制可能涉及 PXDN 功能和正常交联的破坏，从而导致蛋白水解和自身免疫。该特定提案的目的是确定过氧化物酶在发病机制中的作用。 我的试验数据显示，GP 患者体内存在新型抗 PXDN 抗体，可抑制 S=N 键的形成。此外，我发现 PXDN 可以使用单磷酸核苷酸而不是过氧化氢 (H2O2) 来形成 S=N 键。这些发现引出了一个中心假设，即抗过氧化物酶抗体通过阻止硫亚胺键的形成在 GP 疾病的发病机制中发挥关键作用。该假设将受到质疑。具有三个具体目标： 目标 1：表征 Goodpasture 患者中的抗过氧化物酶抗体 我已鉴定出具有抗过氧化物酶抗体的 Goodpasture 患者，我们发现抗过氧化物酶抗体靶向过氧化物酶结构域并使 S=N 键形成活性失活。目标 2：确定古德帕斯彻氏病患者血清样本中抗过氧化物酶抗体的出现时间过程和结合特征。古德帕斯彻氏病出现之前的 30 名患者将提供抗 PXDN 抗体的时间分辨率，我们发现抗过氧化物酶抗体在古德帕斯彻氏病中起着因果作用。 目标 3：确定用于形成 S=N 键的初始氧化剂来源。过氧化氢是过氧化酶的推定氧化剂，但初步数据表明 PXDN 能够使用核苷酸单磷酸作为初始氧化剂。我们研究过氧化物酶使用 O2 和细胞外核苷酸作为初始氧化剂形成 HOBr，用于 S=N 键的生物合成。这些目标的实现将为了解自身免疫性疾病发病机制提供新的见解。通过了解组织生物合成中前所未有的酶促机制的抑制，能够早期诊断 GP 疾病。