ABSTRACT
To identify special metabolites in synovial fluid of osteoarthritis (OA) via a metabolomics approach. Synovial fluid of 35 participants (25 OA patients and 10 controls) was detected by GC-TOF/MS and multivariate data analysis was applied to analyze correlation among the observations. Different metabolites were screened by VIP value (VIP > 1), student t-test (p < 0.05), and fold change (fold >1.5), and verified with the standard metabolites in the synovial fluid of 24 OA patients and 11 controls by LC/MS. The classification performance of different metabolites was analyzed by receiver operating characteristic (ROC) analysis. The results showed that six different metabolites (glutamine, 1,5-anhydroglucitol, gluconic lactone, tyramine, threonine, and 8-aminocaprylic acid) were strongly associated with OA in global metabolomics. Verified results of the first three metabolites were the same as the identified results using targeted metabolomics. ROC curve analysis demonstrated that their concentrations in synovial fluid were strongly correlated to OA. In addition, the concentrations of gluconic lactone were significantly different between OA and RA. Metabolites with altered levels may be contributors to OA pathogenesis and can be used as potential diagnosis criteria for OA. Gluconic lactone may prove to be a novel criterion for differential diagnosis of OA from RA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1973-1981, 2017.
Subject(s)
Metabolome , Osteoarthritis, Knee/metabolism , Synovial Fluid/metabolism , Arthritis, Rheumatoid/metabolism , Case-Control Studies , Deoxyglucose/metabolism , Female , Gluconates/metabolism , Glutamine/metabolism , Humans , Lactones/metabolism , Male , Metabolomics , Middle AgedABSTRACT
10-hydroxy-2-decenoic acid (10H2DA) is suggested to be a potential medication for rheumatoid arthritis (RA) by activation of matrix metalloproteinases (MMPs) via mitogen-activated protein kinase signaling pathways. The aim of the present work was to seek differentially expressed proteins in rheumatoid arthritis synovial fibroblasts (RASFs) treated with 10H2DA by comparative proteomics analysis. Two-dimensional electrophoresis (2-DE) and LC-MS/MS were performed to identify changes in protein expression after 24-h 10H2DA treatment. Differentially expressed proteins were identified by real-time PCR and Western blot analysis. Influence of down-regulation of connective tissue growth factor (CTGF) expression on MMPs was studied by RNAi. Ten proteins were up-regulated and 9 proteins were down-regulated after 24-h 10H2DA treatment. A total of 19 differentially expressed proteins were identified and found to be associated with glycolysis, lipid metabolism, cell adhesion, ATP synthesis, oxidation reduction, and anti-apoptosis. CTGF, a member of the C-terminal cystein-rich proteins (CCN) family, was down-regulated after 24-h 10H2DA treatment. MMPs were down-regulated after RNAi (CTGFi). These results suggest that CTGF is a regulator factor in the expression of MMPs, and 10H2DA down-regulate the concentration of MMPs probably by down-regulating the expression of CTGF.
Subject(s)
Arthritis, Rheumatoid/metabolism , Connective Tissue Growth Factor/metabolism , Down-Regulation/drug effects , Fatty Acids, Monounsaturated/pharmacology , Matrix Metalloproteinases/metabolism , Arthritis, Rheumatoid/pathology , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Connective Tissue Growth Factor/drug effects , Connective Tissue Growth Factor/genetics , Humans , Matrix Metalloproteinases/drug effects , Proteomics , RNA, Small Interfering/pharmacology , Synovial Membrane/drug effects , Synovial Membrane/metabolism , Synovial Membrane/pathologyABSTRACT
AIM OF THE STUDY: Rheumatoid arthritis synovial fibroblasts (RASFs) are known to produce matrix metalloproteinases (MMPs) and cause joint destruction. The purpose of this study is to develop a potential medicine for rheumatoid arthritis (RA). MATERIALS AND METHODS: To this end, first, the MMPs inhibition factor was purified from an alkali-solubilized fraction of RJ (Apis mellifera) by C18 reverse-phase column chromatography and identified as 10-hydroxy-2-decenoic acid (10H2DA) by LTQ XL analysis. Next, Experimental test 10H2DA how to inhibited the activities of MMPs: with RASFs isolated from rheumatoid tissues by enzymatic digestion, cultures in monolayers were treated with 10H2DA (0.5mM, 1mM, and 2mM) or PBS for 2h followed by stimulation with TNF-alpha (10 ng/ml) for 2h, mRNA. Protein levels of MMP-1 and MMP-3 were measured by real-time PCR and enzyme-linked immunosorbent assay (ELISA), the DNA-binding activity of activator protein-1 (AP-1) and nuclear factor kappaB (NF-kappaB) by electrophoretic mobility shift assay (EMSA), and the protein kinase activity of p38, ERK and JNK by kinase assay. RESULTS: The molecular investigation revealed that the 10H2DA-mediated suppression was likely to occur through blocking p38 kinase and c-Jun N-terminal kinase-AP-1 signaling pathways. In contrast, 10H2DA had no effect on extracellular signal-regulated kinase activity, NF-kappaB DNA-binding activity and IkappaBalpha degradation. CONCLUSION: These results suggest that 10H2DA may be of potential therapeutic value in inhibiting joint destruction in RA.
