Synovial fluid proteome in rheumatoid arthritis

Abstract

BackgroundRheumatoid arthritis (RA) is a chronic autoinflammatory disorder that affects small joints. Despite intense efforts, there are currently no definitive markers for early diagnosis of RA and for monitoring the progression of this disease, though some of the markers like anti CCP antibodies and anti vimentin antibodies are promising. We sought to catalogue the proteins present in the synovial fluid of patients with RA. It was done with the aim of identifying newer biomarkers, if any, that might prove promising in future.MethodsTo enrich the low abundance proteins, we undertook two approaches—multiple affinity removal system (MARS14) to deplete some of the most abundant proteins and lectin affinity chromatography for enrichment of glycoproteins. The peptides were analyzed by LC–MS/MS on a high resolution Fourier transform mass spectrometer.ResultsThis effort was the first total profiling of the synovial fluid proteome in RA that led to identification of 956 proteins. From the list, we identified a number of functionally significant proteins including vascular cell adhesion molecule-1, S100 proteins, AXL receptor protein tyrosine kinase, macrophage colony stimulating factor (M-CSF), programmed cell death ligand 2 (PDCD1LG2), TNF receptor 2, (TNFRSF1B) and many novel proteins including hyaluronan-binding protein 2, semaphorin 4A (SEMA4D) and osteoclast stimulating factor 1. Overall, our findings illustrate the complex and dynamic nature of RA in which multiple pathways seems to be participating actively.ConclusionsThe use of high resolution mass spectrometry thus, enabled identification of proteins which might be critical to the progression of RA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12014-016-9113-1) contains supplementary material, which is available to authorized users.

ATP triggers a robust intracellular [Ca2+]‐mediated signalling pathway in human synovial fibroblasts

“…Additional tests confirmed (data not shown) that UTP (either 50 M, n = 2, or 100 M, n = 2) produced similar responses, as did ADP at 100 M, n = 4, or 250 M. In all cases, however, the ADP responses were significantly smaller (approx. 50%) than the 100 M ATP responses (Bhattacharjee et al, 2016;Hui, McCarty, Masuda, Firestein, & Sah, 2012; NCBI GEO dataset GSE21959).…”

“…This pattern of findings is corroborated by the NCBI GEO database dataset GSE21959 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE21959). This database consists of a comprehensive survey of relative transcript levels in human HSF cells under (i) normoxic or baseline conditions, (ii) hypoxic but otherwise baseline conditions, and both normoxic (iii) and hypoxic (iv) conditions in HSF cells from human articular joints in which the donors had documented and staged rheumatoid arthritis (Bhattacharjee et al., ; Hui, McCarty, Masuda, Firestein, & Sah, ; NCBI GEO dataset GSE21959).…”

“…However, we also anticipate that these studies will need to be designed and carried out in such a way that key elements and aspects of a sterile inflammatory environment can be introduced progressively, one element at a time – ATP, cytokines, osmolarity and pH changes, etc. (Bhattacharjee et al., ; McInnes & Schett, ) – and then in combination (cf. Dib‐Hajj, Black, Cummins, & Waxman, ).…”

“…Since some isoforms of adenylyl cyclase are Ca 2+ dependent it is possible that both of the agonists described in this paper could reduce fibrosis. Examination of this possibility and a number of others will be guided and accelerated by recent papers regarding the articular joint transciptome and proteome (Bhattacharjee et al., ; Cepika et al., )‐related systems biology methods and approaches (Distler et al., ; Groenendyk et al., ; Hui et al., ; Ogawa et al., ; Aitchison and Rout, ) and emerging knowledge of the cytokine profile in these joints under baseline conditions and as documented arthritis phenotypes are initiated and progress (Armaka et al., ).…”

Liquid‐phase based separation systems for depletion, prefractionation, and enrichment of proteins in biological fluids and matrices for in‐depth proteomics analysis—An update covering the period 2014–2016

“…A multiple affinity removal of HAPs and enrichment of glycoproteins from the SF of patients has been performed for facilitating identification of newer biomarkers for early diagnosis of rheumatoid arthritis . MARS‐14 mini spin column was employed to remove HAPs including albumin, IgG, antitrypsin, IgA, transferrin, haptoglobin, fibrinogen, alpha2‐macroglobulin, alpha1‐acid glycoprotein, IgM, apolipoprotein AI, apolipoprotein AII, complement C3, and transthyretin from SF.…”