Dataset Information

Identification of psoriatic arthritis mediators in synovial fluid by quantitative mass spectrometry.

ABSTRACT:

Background

Synovial fluid (SF) is a dynamic reservoir for proteins originating from the synovial membrane, cartilage, and plasma, and may therefore reflect the pathophysiological conditions that give rise to arthritis. Our goal was to identify and quantify protein mediators of psoriatic arthritis (PsA) in SF.

Methods

Age and gender-matched pooled SF samples from 10 PsA and 10 controls [early osteoarthritis (OA)], were subjected to label-free quantitative proteomics using liquid chromatography coupled to mass spectrometry (LC-MS/MS), to identify differentially expressed proteins based on the ratios of the extracted ion current of each protein between the two groups. Pathway analysis and public database searches were conducted to ensure these proteins held relevance to PsA. Multiplexed selected reaction monitoring (SRM) assays were then utilized to confirm the elevated proteins in the discovery samples and in an independent set of samples from patients with PsA and controls.

Results

We determined that 137 proteins were differentially expressed between PsA and control SF, and 44 were upregulated. The pathways associated with these proteins were acute-phase response signalling, granulocyte adhesion and diapedesis, and production of nitric oxide and reactive oxygen species in macrophages. The expression of 12 proteins was subsequently quantified using SRM assays.

Conclusions

Our in-depth proteomic analysis of the PSA SF proteome identified 12 proteins which were significantly elevated in PsA SF compared to early OA SF. These proteins may be linked to the pathogenesis of PsA, as well serve as putative biomarkers and/or therapeutic targets for this disease.

SUBMITTER: Cretu D

PROVIDER: S-EPMC4108225 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Publications

Identification of psoriatic arthritis mediators in synovial fluid by quantitative mass spectrometry.

Cretu Daniela D Prassas Ioannis I Saraon Punit P Batruch Ihor I Gandhi Rajiv R Diamandis Eleftherios P EP Chandran Vinod V

Clinical proteomics 20140701 1

<h4>Background</h4>Synovial fluid (SF) is a dynamic reservoir for proteins originating from the synovial membrane, cartilage, and plasma, and may therefore reflect the pathophysiological conditions that give rise to arthritis. Our goal was to identify and quantify protein mediators of psoriatic arthritis (PsA) in SF.<h4>Methods</h4>Age and gender-matched pooled SF samples from 10 PsA and 10 controls [early osteoarthritis (OA)], were subjected to label-free quantitative proteomics using liquid ch ...[more]

PMID: 25097465

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Project description:Background:Inflammatory arthritis (IA) is an immunological disorder in which loss of immune tolerance to endogenous self-antigens perpetuates synovitis and eventual destruction of the underlying cartilage and bone. Pathological changes in the joint are expected to be represented by synovial fluid (SF) proteins and peptides. In the present study, a mass spectrometry-based approach was utilized for the identification of key protein and peptide mediators of IA. Methods:Age-matched SF samples from 10 rheumatoid arthritis patients, 10 psoriatic arthritis patients and 10 cadaveric controls were subjected to an integrated proteomic and peptidomic protocol using liquid chromatography tandem mass spectrometry. Significant differentially abundant proteins and peptides were identified between cohorts according to the results of a Mann-Whitney U test coupled to the Benjamini-Hochberg correction for multiple hypothesis testing. Fold change ratios were computed for each protein and peptide according to their log-transformed extracted ion current. Pathway analysis and antimicrobial peptide (AMP) prediction were conducted to clarify the pathophysiological relevance of identified proteins and peptides to IA. Results:We determined that 144 proteins showed significant differential abundance between the IA and control SF proteomes, of which 11 protein candidates were selected for future follow-up studies. Similar analyses applied to our peptidomic data identified 15 peptide sequences, originating from 4 protein precursors, to have significant differential abundance in IA compared to the control SF peptidome. Pathway enrichment analysis of the IA SF peptidome along with AMP prediction suggests a possible mechanistic role of microbes in eliciting an immune response which drives the development of IA. Conclusions:The discovery-phase data generated herein has provided a basis for the identification of candidates with the greatest potential to serve as novel serum biomarkers specific to inflammatory arthritides. Moreover, these findings facilitate the understanding of possible disease mechanisms specific to each subtype.

Project description: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.

Project description:The aim was to study changes in immunohistochemical expression markers of synovial and skin inflammation, clinical outcomes and magnetic resonance imaging (MRI) scores with abatacept treatment in patients with psoriatic arthritis (PsA).Biological-treatment-naïve PsA patients with active disease including synovitis of a knee were enrolled in this single-centre, crossover study. Patients were randomised to receive intravenous abatacept 3 mg/kg of body weight or placebo infusion on day 1, 15 and 29; thereafter abatacept 10 mg/kg of body weight was administered every 28 days for 5 months. Clinical data were collected at each visit. Synovial biopsy of the involved knee was obtained at baseline and 2 and 6 months. MRI of the same knee and skin biopsy was performed prior to arthroscopy.Fifteen patients were recruited. Significant improvements in the joint-related measures were observed; 90% were European League Against Rheumatism criteria responders and 30% achieved psoriasis area severity index (PASI)50 at 6 months. Reduction in synovitis (P?=?0.016) and vascularity (P?=?0.039) macroscopic scores consistent with decrease in total MRI score (P?=?0.016) were noticed. Abatacept decreased the immunohistological expression of FOXP3+ cells (P?=?0.027), specifically the expression of CD4+FOXP3+ regulatory T cells (Tregs) (P?=?0.008) in the synovium over 6 months. There was no significant clinical or immunohistological change in any of the skin measures.This is the first study assessing synovial and psoriatic skin immunpathological changes following abatacept treatment in PsA. Reduction in Treg expression in the synovium but not in the psoriatic lesion suggests abnormal Treg function in PsA with differential suppressive capacity in the synovium compared to the lesional skin. The results of this study demonstrate that abatacept 10 mg/kg of body weight might be an effective treatment option for joint disease in patients with PsA.Irish Health Products Regulatory Authority.CT 900/489/1 - Abatacept (case number: 2077284, EudraCT Number: 2009-017525-19, Protocol number: 77777). Registered on 12 March 2010.

Dataset Information

Identification of psoriatic arthritis mediators in synovial fluid by quantitative mass spectrometry.

Background

Methods

Results

Conclusions

Publications

Identification of psoriatic arthritis mediators in synovial fluid by quantitative mass spectrometry.

Similar Datasets

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