Skip to main content
main-content

01.12.2018 | Research article | Ausgabe 1/2018 Open Access

Arthritis Research & Therapy 1/2018

Two independent proteomic approaches provide a comprehensive analysis of the synovial fluid proteome response to Autologous Chondrocyte Implantation

Zeitschrift:
Arthritis Research & Therapy > Ausgabe 1/2018
Autoren:
Charlotte H. Hulme, Emma L. Wilson, Heidi R. Fuller, Sally Roberts, James B. Richardson, Pete Gallacher, Mandy J. Peffers, Sally L. Shirran, Catherine H. Botting, Karina T. Wright
Wichtige Hinweise

Electronic supplementary material

The online version of this article (https://​doi.​org/​10.​1186/​s13075-018-1573-4) contains supplementary material, which is available to authorized users.

Abstract

Background

Autologous chondrocyte implantation (ACI) has a failure rate of approximately 20%, but it is yet to be fully understood why. Biomarkers are needed that can pre-operatively predict in which patients it is likely to fail, so that alternative or individualised therapies can be offered. We previously used label-free quantitation (LF) with a dynamic range compression proteomic approach to assess the synovial fluid (SF) of ACI responders and non-responders. However, we were able to identify only a few differentially abundant proteins at baseline. In the present study, we built upon these previous findings by assessing higher-abundance proteins within this SF, providing a more global proteomic analysis on the basis of which more of the biology underlying ACI success or failure can be understood.

Methods

Isobaric tagging for relative and absolute quantitation (iTRAQ) proteomic analysis was used to assess SF from ACI responders (mean Lysholm improvement of 33; n = 14) and non-responders (mean Lysholm decrease of 14; n = 13) at the two stages of surgery (cartilage harvest and chondrocyte implantation). Differentially abundant proteins in iTRAQ and combined iTRAQ and LF datasets were investigated using pathway and network analyses.

Results

iTRAQ proteomic analysis confirmed our previous finding that there is a marked proteomic shift in response to cartilage harvest (70 and 54 proteins demonstrating ≥ 2.0-fold change and p < 0.05 between stages I and II in responders and non-responders, respectively). Further, it highlighted 28 proteins that were differentially abundant between responders and non-responders to ACI, which were not found in the LF study, 16 of which were altered at baseline. The differential expression of two proteins (complement C1s subcomponent and matrix metalloproteinase 3) was confirmed biochemically. Combination of the iTRAQ and LF proteomic datasets generated in-depth SF proteome information that was used to generate interactome networks representing ACI success or failure. Functional pathways that are dysregulated in ACI non-responders were identified, including acute-phase response signalling.

Conclusions

Several candidate biomarkers for baseline prediction of ACI outcome were identified. A holistic overview of the SF proteome in responders and non-responders to ACI  has been profiled, providing a better understanding of the biological pathways underlying clinical outcome, particularly the differential response to cartilage harvest in non-responders.
Zusatzmaterial
Additional file 1: Table S1. Canonical pathways altered in the synovial fluid of clinical nonresponders at stage I compared with stage II of ACI, identified using Ingenuity Pathway Analysis based on proteins that were identified using iTRAQ proteomics (≥ 1.2-fold change). Significance was assessed using a right-sided Fisher’s exact test; therefore, the most significant canonical pathways represent those that are the least likely to have been identified because of molecules being in the canonical pathway by random chance. The z-score represents canonical pathways that are likely activated or inhibited (based on the pattern of differentially abundant proteins); NaN means no prediction could be made based on the number of differentially abundant proteins in the pathway. Table S2. Canonical pathways altered in the synovial fluid of clinical responders at stage I compared with stage II of ACI, identified using Ingenuity Pathway Analysis, based on proteins which were identified using iTRAQ proteomics (≥ 1.2-fold change). Significance was assessed using a right-sided Fisher’s exact test; therefore, the most significant canonical pathways represent those that are the least likely to have been identified because of molecules being in the canonical pathway by random chance. The z-score represents canonical pathways that are likely activated or inhibited (based on the pattern of differentially abundant proteins); NaN means no prediction could be made based on the number of differentially abundant proteins in the pathway. (XLSX 19 kb)
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2018

Arthritis Research & Therapy 1/2018 Zur Ausgabe