Institute of Bioinformatics, International Technology Park, Bangalore 560066, India.
Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam 690525, India.
Clin Proteomics. 2013 Sep 6;10(1):11. doi: 10.1186/1559-0275-10-11.
Arthritis refers to inflammation of joints and includes common disorders such as rheumatoid arthritis (RA) and spondyloarthropathies (SpAs). These diseases differ mainly in terms of their clinical manifestations and the underlying pathogenesis. Glycoproteins in synovial fluid might reflect the disease activity status in the joints affected by arthritis; yet they have not been systematically studied previously. Although markers have been described for assisting in the diagnosis of RA, there are currently no known biomarkers for SpA.
We sought to determine the relative abundance of glycoproteins in RA and SpA by lectin affinity chromatography coupled to iTRAQ labeling and LC-MS/MS analysis. We also used ELISA to validate the overexpression of VCAM-1, one of the candidate proteins identified in this study, in synovial fluid from RA patients.
We identified proteins that were previously reported to be overexpressed in RA including metalloproteinase inhibitor 1 (TIMP1), myeloperoxidase (MPO) and several S100 proteins. In addition, we discovered several novel candidates that were overexpressed in SpA including Apolipoproteins C-II and C-III and the SUN domain-containing protein 3 (SUN3). Novel molecules found overexpressed in RA included extracellular matrix protein 1 (ECM1) and lumican (LUM). We validated one of the candidate biomarkers, vascular cell adhesion molecule 1 (VCAM1), in 20 RA and SpA samples using ELISA and confirmed its overexpression in RA (p-value <0.01). Our quantitative glycoproteomic approach to study arthritic disorders should open up new avenues for additional proteomics-based discovery studies in rheumatological disorders.
关节炎是指关节炎症，包括常见疾病，如类风湿关节炎（RA）和脊柱关节病（SpA）。这些疾病主要在临床表现和潜在发病机制方面存在差异。滑液中的糖蛋白可能反映受关节炎影响的关节的疾病活动状态；然而，它们以前并未得到系统研究。虽然已经描述了用于协助 RA 诊断的标志物，但目前尚无用于 SpA 的已知生物标志物。
我们试图通过凝集素亲和色谱法与 iTRAQ 标记和 LC-MS/MS 分析来确定 RA 和 SpA 中的糖蛋白相对丰度。我们还使用 ELISA 验证了在 RA 患者的滑液中，本研究中鉴定出的候选蛋白之一 VCAM-1 的过表达。
我们鉴定出了以前报道在 RA 中过表达的蛋白，包括金属蛋白酶抑制剂 1（TIMP1）、髓过氧化物酶（MPO）和几种 S100 蛋白。此外，我们还发现了几种在 SpA 中过表达的新候选物，包括载脂蛋白 C-II 和 C-III 以及 SUN 结构域包含蛋白 3（SUN3）。在 RA 中发现过表达的新分子包括细胞外基质蛋白 1（ECM1）和亮氨酸丰富重复蛋白聚糖（LUM）。我们使用 ELISA 在 20 个 RA 和 SpA 样本中验证了一个候选生物标志物，血管细胞黏附分子 1（VCAM1），并证实其在 RA 中过表达（p 值<0.01）。我们研究关节炎疾病的定量糖蛋白质组学方法应该为风湿病学疾病中的其他基于蛋白质组学的发现研究开辟新途径。
