Objective: To determine whether an aggrecan 32-mer fragment derived from dual ADAMTS and matrix metalloproteinase (MMP) cleavage in the aggrecan interglobular domain was bioactive and, if so, to elucidate its mechanism of action.
Methods: Mouse primary chondrocytes, synovial fibroblasts, or peritoneal macrophages, human primary chondrocytes, and cells or cell lines from myeloid differentiation factor 88 (MyD88)-deficient and Toll-like receptor 2 (TLR-2)-deficient mice were stimulated with synthetic mouse 32-mer peptide, human 32-mer peptide, a 32-mer scrambled peptide, or native, glycosylated 32-mer peptide. Cells stimulated with 32-mer peptide were analyzed for changes in messenger RNA (mRNA) expression by quantitative polymerase chain reaction. Conditioned medium was analyzed for levels of interleukin-6 protein by an AlphaLISA or for levels of MMP-3 and MMP-13 protein by Western blotting. NF-κB activation was measured in a luciferase reporter assay.
Results: Treatment of mouse cells or cartilage explants with 32-mer peptide or scrambled peptide revealed that the 32-mer peptide, but not the scrambled peptide, had antianabolic, procatabolic, and proinflammatory bioactivity in vitro. Chondrocytes, synovial fibroblasts, and macrophages from MyD88-deficient mice failed to respond to 32-mer peptide stimulation. A macrophage cell line derived from TLR-2-deficient mice also failed to respond to 32-mer peptide stimulation. Stimulation of human chondrocytes with human 32-mer peptide increased the expression of catabolic markers at the mRNA and protein levels. Mouse and human 32-mer peptide stimulated NF-κB activation in a TLR-2-dependent reporter assay, and the response of chondrocytes from both species to native, glycosylated 32-mer peptide was similar to the response to synthetic peptides.
Conclusion: The aggrecan 32-mer fragment is a novel endogenous ligand of TLR-2 with the potential to accelerate cartilage destruction in vivo.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/art.39063 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The C-terminal 32-mer fragment of hemoglobin alpha is an amyloidogenic peptide with antimicrobial properties.
Cell Mol Life Sci
May 2023
Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany.
Antimicrobial peptides (AMPs) are major components of the innate immune defense. Accumulating evidence suggests that the antibacterial activity of many AMPs is dependent on the formation of amyloid-like fibrils. To identify novel fibril forming AMPs, we generated a spleen-derived peptide library and screened it for the presence of amyloidogenic peptides.
View Article and Find Full Text PDFProteomic Profiling of Mouse Brain Pyruvate Kinase Binding Proteins: A Hint for Moonlighting Functions of PKM1?
Int J Mol Sci
April 2023
Institute of Biomedical Chemistry, 10 Pogodinskaya Street, Moscow 119121, Russia.
Affinity-based proteomic profiling is widely used for the identification of proteins involved in the formation of various interactomes. Since protein-protein interactions (PPIs) reflect the role of particular proteins in the cell, identification of interaction partners for a protein of interest can reveal its function. The latter is especially important for the characterization of multifunctional proteins, which can play different roles in the cell.
View Article and Find Full Text PDFT-cell surface generation of dual bivalent, bispecific T-cell engaging, RNA duplex cross-linked antibodies (dbBiTERs) for re-directed tumor cell lysis.
Biotechnol J
February 2022
Department of Immunology and Theranostics, City of Hope, Duarte, California, USA.
Background: Genetic engineered Bispecific T-cell engagers (BiTEs) generate potent cytotoxic effects.
Methods: Alternately, click chemistry engineered, dual specific bivalent Bispecific T-cell engaging antibodies (dbBiTEs) on T-cell surfaces can be generated from parent monoclonal antibodies.
Results: We show the formation of dbBiTEs on the surface of T-cells along with the introduction of complementary 2'-OMe RNA 32-mer oligonucleotides allowing duplex formation between antibodies, designated as dbBiTERs.
New-Level Insights into the Effects of Grape Seed Polyphenols on the Intestinal Processing and Transport of a Celiac Disease Immunodominant Peptide.
J Agric Food Chem
November 2021
LAQV-REQUIMTE Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, Porto 4169-007, Portugal.
The effect of three dietary tannins (procyanidin B3, B6, and T2) on the bioavailability of the 32-mer gliadin-derived immunogenic peptide was evaluated. An enterocyte-like Caco-2 cell line was used to mimic the epithelial transport of the 32-mer peptide, which was modeled by kinetic parameters with a mass spectrometry approach. The hydrolysis pattern on the enterocytes was analyzed, and the released peptides were quantified during the assay.
View Article and Find Full Text PDFInflammation and joint destruction may be linked to the generation of cartilage metabolites of ADAMTS-5 through activation of toll-like receptors.
Osteoarthritis Cartilage
May 2020
Rheumatology, Nordic Bioscience, Herlev Hovedgade 207, DK-2730, Herlev, Denmark. Electronic address:
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.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!