Peptidylarginine deiminase type 6 in rheumatoid arthritis pathogenesis

类风湿性关节炎发病机制中的 6 型肽基精氨酸脱亚胺酶

基本信息

批准号：
10317620
负责人：
Felipe Andrade
金额：
$ 39.63万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-23 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10317620
关键词：
Address Antigens Area Arginine Autoantibodies Binding Binding Sites Biochemical Biological Assay C-terminal Calcium Calcium Binding Catalysis Cells Cessation of life Citrulline Data Disease Disease Outcome Enzymes Event Family Germ Cells Goals Human Immune Immune Targeting Immune system Isoenzymes Joints Kinetics Lead Length Leukocytes Link Liver Lung Mediating Oocytes Pathogenesis Pathogenicity Pathologic Pathway interactions Patients Physiological Play Process Production Protein Isoforms Protein-arginine deiminase Proteins RNA Splicing Regulatory Pathway Research Rest Rheumatoid Arthritis Role Small Intestines Source Spleen Synovial Fluid Therapeutic Intervention Time Tissues Transcript Variant Work citrullinated protein human model in vitro activity in vivo insight interest member mutant neutrophil novel novel therapeutic intervention novel therapeutics peripheral blood response skeletal

项目摘要

PROJECT SUMMARY/ABSTRACT Citrullinated proteins are major targets of the immune system in rheumatoid arthritis (RA), with recent evidence suggesting that mechanisms that enhance citrullination are associated with the worst disease outcome. Protein citrullination is the enzymatic conversion of arginine residues to citrulline and is mediated by the family of calcium- dependent peptidylarginine deiminase (PAD) enzymes. Five PAD members have been found in humans, PAD1- 4, and the catalytically inactive PAD6. While several mechanisms have been linked to abnormal citrullination in RA, including hyperactivation of PADs (particularly PAD4) during neutrophil death and the production of autoantibodies that enhance PAD4 activity, regulatory pathways that control citrullination are poorly understood. Since PADs require supraphysiologic concentrations of calcium for activity in vitro, it is suspected that PAD activation in vivo requires additional factors that modulate the enzyme’s sensitivity for calcium. Such co-factors, however, have not been identified. Our preliminary data demonstrate that PAD6, which has no citrullinating activity, and 3 novel PAD6 splicing variants described for the first time in this proposal, act as co-factors that decrease the calcium requirement of PAD4 for catalysis. Moreover, we found that all PAD6 variants are abundant in neutrophils, which are considered a major source of citrullinated proteins in the RA joint. Taken together, we hypothesize that PAD6 and its variants may be responsible for modulating the magnitude of PAD4 activity both in physiologic and pathologic conditions. We will examine this hypothesis directly in the human model in three specific aims. In Aim 1, we will define how PAD6 variants regulate PAD4 activity with the goal of identifying the biochemical mechanisms by which PAD6 variants decrease the calcium requirement of PAD4. Aim 2 will define the expression and function of PAD6 and its splicing variants at the cellular level. Aim 3 will study the expression of PAD6 isoforms in RA synovial fluid to address their relationship with the abnormal production of citrullinated proteins in RA. Together, these studies will define novel interacting mechanisms of disease amplification relevant to sustain the production of citrullinated proteins in the RA joints. Furthermore, these studies may provide evidence for targeting PAD6 as a novel therapeutic strategy to modulate PAD4 activity, which is highly significant for diseases in which citrullination has been pathogenically implicated.

项目摘要/摘要瓜氨酸蛋白是类风湿关节炎（RA）的免疫系统的主要靶标，最近的证据表明增强柠檬化的机制与最严重的疾病结果有关。蛋白质柠檬化是精氨酸残基到瓜氨酸的酶促转化，由钙的家族介导依赖性肽基金氨氨酸脱节酶（PAD）酶。在人类中发现了五个PAD成员，Pad1- 4和催化无效的垫子6。虽然几种机制已与异常的柠檬化有关 RA，包括在中性粒细胞死亡期间垫（尤其是PAD4）的过度激活和产生对控制柠檬酸的调节途径增强PAD4活性的自身抗体对控制柠檬酸的了解很少。由于垫需要钙的超生理浓度才能在体外活性，因此怀疑垫子是否存在体内激活需要调节酶对钙的敏感性的其他因素。这样的联合因素，但是，尚未确定。我们的初步数据表明，PAD6，没有粉状的粉状活性和3个新型PAD6剪接变体首次在此提案中描述减少PAD4催化的钙需求。此外，我们发现所有PAD6变体都丰富在中性粒细胞中，这被认为是RA关节中瓜氨酸蛋白的主要来源。总的来说，我们假设PAD6及其变体可能负责调节PAD4活性的大小在生理和病理状况中。我们将直接在三个人类模型中检查这一假设具体目标。在AIM 1中，我们将定义PAD6变体如何调节PAD4活动，以识别 PAD6变体降低PAD4的钙需求的生化机制。 AIM 2将定义 PAD6及其剪接变体在细胞水平上的表达和功能。 AIM 3将研究表达 RA滑液中的PAD6同工型，以解决它们与瓜氨酸异常产生的关系 RA中的蛋白质。这些研究将共同定义疾病扩增的新型相互作用机制相关维持RA关节中瓜氨酸蛋白的生产。此外，这些研究可能提供将PAD6作为一种新型治疗策略来调节PAD4活动的证据，这是非常重要的对于柠檬酸的疾病，已在病原上涉及。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Heavy Chain Constant Region Usage in Antibodies to Peptidylarginine Deiminase 4 as a Marker of Disease Subsets in Rheumatoid Arthritis.

DOI：
10.1002/art.42262
发表时间：
2022-11
期刊：
ARTHRITIS & RHEUMATOLOGY
影响因子：
13.3
作者：
Gomez-Banuelos, E.;Shi, J.;Wang, H.;Danila, M., I;Bridges, S. L.;Giles, J. T.;Sims, G. P.;Andrade, F.;Darrah, E.
通讯作者：
Darrah, E.

Microbial pathways to subvert host immunity generate citrullinated neoantigens targeted in rheumatoid arthritis.