Inflammation and joint destruction may be linked to the generation of cartilage metabolites of ADAMTS-5 through activation of toll-like receptors
Research output: Contribution to journal › Journal article › Research › peer-review
Objective: Links between pain and joint degradation are poorly understood. We investigated the role of activation of Toll-like receptors (TLR) by cartilage metabolites in initiating and maintaining the inflammatory loop in OA causing joint destruction.
Methods: Synovial membrane explants (SMEs) were prepared from OA patients' synovial biopsies. SMEs were cultured for 10 days under following conditions: culture medium alone, OSM thorn TNF alpha, TLR2 agonist - Pam2CSK4, Pam3CSK4 or synthetic aggrecan 32-mer, TLR4 agonist - Lipid A. Release of pro-inflammatory and degradation biomarkers (acMMP3 and C3M) were measured by ELISA in conditioned media along with IL-6. Additionally, human cartilage was digested with ADAMTS-5, with or without the ADAMTS-5 inhibiting nanobody - M6495. Digested cartilage solution (DCS) and synthetic 32-mer were tested for TLR activation in SEAP based TLR reporter assay.
Results: Western blotting confirmed TLR2 and TLR4 in untreatedOA synovial biopsies. TLR agonists showed an increase in release of biomarkers - acMMP3 and C3M in SME. Synthetic 32-mer showed no activation in the TLR reporter assay. ADAMTS-5 degraded cartilage fragments activated TLR2 in vitro. AddingM6495 - an anti-ADAMTS-5 inhibiting nanobody (R), blocked ADAMTS-5-mediated DCS TLR2 activation.
Conclusion: TLR2 is expressed in synovium of OA patients and their activation by synthetic ligands causes increased tissue turnover. ADAMTS-5-mediated cartilage degradation leads to release of aggrecan fragments which activates the TLR2 receptor in vitro. M6495 suppressed cartilage degradation by ADAMTS-5, limiting the activation of TLR2. In conclusion, pain and joint destruction may be linked to generation of ADAMTS-5 cartilage metabolites. (C) 2019 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Original language | English |
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Journal | Osteoarthritis and Cartilage |
Volume | 28 |
Issue number | 5 |
Pages (from-to) | 658-668 |
ISSN | 1063-4584 |
DOIs | |
Publication status | Published - 2020 |
- Toll like receptors (TLRs), Synovial membrane, Osteoarthritis (OA), Inflammation, Innate immunity, OSTEOARTHRITIS PATIENTS, DEGRADATION, PATHOGENESIS, HYALURONAN, EXPRESSION, SYNOVITIS, SYMPTOMS, COLLAGEN, DISEASE, TISSUE
Research areas
ID: 252473712