Department of Emergency, Chinese PLA General Hospital, Beijing 100853, P.R. China.
Department of Orthopedics, Chinese PLA General Hospital, Beijing 100853, P.R. China.
Mol Med Rep. 2018 Feb;17(2):2827-2836. doi: 10.3892/mmr.2017.8250. Epub 2017 Dec 11.
The lack of early diagnostic maneuvers and effective pharmacotherapy for osteoarthritis (OA) is predominantly attributed to current limited understanding of its pathogenesis. In the present study, the alteration of synovial fluid (SF) proteome in OA were analyzed using SWATH‑mass spectrometry (SWATH‑MS) to further elucidate the pathogenesis of OA. SF samples were collected from 10 OA and 10 rheumatoid arthritis (RA) patients undergoing arthroplasty and 10 patients undergoing arthroscopy for traumatic arthritis (meniscus injury without cartilage lesion). According to the Kellgren‑Lawrence (KL) radiographic grading criteria, all the OA and RA patients were classified as KL grade 4. SWATH‑MS was applied to identify differentially expressed proteins specifically regulated in OA. Differentially expressed proteins identified by SWATH‑MS were subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation. Proteins of interest were quantified by enzyme‑linked immunosorbent assay (ELISA) following identification. With the use of SWATH‑MS, 131 proteins were identified to be differentially expressed in OA, of which 93 corresponded to upregulation and 38 to downregulation. Complement C1r was the most significantly upregulated protein in OA. Twenty‑eight out of the 131 proteins were specifically regulated in OA, of which 17 were upregulated and 11 were downregulated. Dickkopf‑related protein 2 (DKK2) was one of the proteins specifically upregulated in OA. Furthermore, KEGG pathway annotation indicated that differentially expressed proteins in OA were enriched in complement and coagulation cascades. ELISA indicated that OA severity was positively correlated with the levels of complement C1r (r=0.549; P<0.001) and DKK2 (r=0.79; P<0.001) in the SF. The results indicate that complement and coagulation cascades are involved in the pathogenesis of OA. Differentially expressed proteins, including complement C1r and DKK2 may be used as potential biomarkers or drug targets, which may facilitate with intervention of OA.
骨关节炎（OA）缺乏早期诊断手段和有效的药物治疗主要归因于目前对其发病机制的认识有限。在本研究中，我们使用 SWATH-MS 分析 OA 患者滑液（SF）蛋白质组的变化，以进一步阐明 OA 的发病机制。收集了 10 例 OA 和 10 例类风湿关节炎（RA）患者（行关节置换术）以及 10 例创伤性关节炎（半月板损伤无软骨病变，行关节镜检查）患者的 SF 样本。根据 Kellgren-Lawrence（KL）放射学分级标准，所有 OA 和 RA 患者均被归类为 KL 分级 4。SWATH-MS 用于鉴定 OA 特异性调节的差异表达蛋白。SWATH-MS 鉴定的差异表达蛋白进行基因本体（GO）和京都基因与基因组百科全书（KEGG）途径注释。鉴定后通过酶联免疫吸附测定（ELISA）定量感兴趣的蛋白。使用 SWATH-MS，鉴定出 131 种在 OA 中差异表达的蛋白，其中 93 种蛋白上调，38 种蛋白下调。补体 C1r 是 OA 中上调最显著的蛋白。在 131 种差异表达蛋白中，有 28 种蛋白在 OA 中特异性调节，其中 17 种蛋白上调，11 种蛋白下调。Dickkopf 相关蛋白 2（DKK2）是 OA 中特异性上调的蛋白之一。此外，KEGG 途径注释表明 OA 中差异表达蛋白富集在补体和凝血级联反应中。ELISA 表明 SF 中补体 C1r（r=0.549；P<0.001）和 DKK2（r=0.79；P<0.001）水平与 OA 严重程度呈正相关。结果表明，补体和凝血级联反应参与 OA 的发病机制。差异表达蛋白，包括补体 C1r 和 DKK2，可用作潜在的生物标志物或药物靶点，可能有助于 OA 的干预。
