Stimulation of chondrocyte‐mediated cartilage destruction by S100A8 in experimental murine arthritis

Abstract

Objective. To investigate whether S100A8 is actively involved in matrix metalloproteinase (MMP)-mediated chondrocyte activation.Methods. S100A8 and S100A9 proteins were detected in inflamed knee joints from mice with various forms of murine arthritis, using immunolocalization. Murine chondrocyte cell line H4 was stimulated with proinflammatory cytokines or recombinant S100A8. Messenger RNA (mRNA) and protein levels were measured using reverse transcriptase-polymerase chain reaction and intracellular fluorescence-activated cell sorting (FACS). Breakdown of aggrecan on the pericellular surface of the chondrocytes was measured using VDIPEN and NITEGE antibodies and FACS, and breakdown in patellar cartilage was measured by immunolocalization.Results. S100A8 and S100A9 proteins were abundantly expressed in and around chondrocytes in inflamed knee joints after induction of antigen-induced arthritis or onset of spontaneous arthritis in interleukin-1 (IL-1) receptor antagonist-knockout mice. Stimulation of chondrocytes by the proinflammatory cytokines tumor necrosis factor ␣, IL-1␤, IL-17, and interferon-␥ caused strong up-regulation of S100A8 mRNA and protein levels and up-regulation to a lesser extent of S100A9 levels. Stimulation of chondrocytes with S100A8 induced significant up-regulation of MMP-2, MMP-3, MMP-9, MMP-13, ADAMTS-4, and ADAMTS-5 mRNA levels (up-regulated 4, 4, 3, 16, 8, and 4 times, respectively). VDIPEN and NITEGE neoepitopes were significantly elevated in a concentrationdependent manner in chondrocytes treated with 0.2, 1, or 5 g/ml of S100A8. (VDIPEN levels were elevated 17%, 67%, and 108%, respectively, and NITEGE levels were elevated 8%, 33%, and 67%, respectively.) S100A8 significantly increased the effect of IL-1␤ on MMP-3, MMP-13, and ADAMTS-5. Mouse patellae incubated with both IL-1␤ and S100A8 had elevated levels of NITEGE within the cartilage matrix when compared with patellae incubated with IL-1␤ or S100A8 alone.Conclusion. These findings indicate that S100A8 and S100A9 are found in and around chondrocytes in experimental arthritis. S100A8 up-regulates and activates MMPs and aggrecanase-mediated pericellular matrix degradation.Breakdown of the cartilage matrix is one of the hallmarks of rheumatoid arthritis (RA). Cartilage destruction is predominantly mediated by cytokines, enzymes, and oxygen radicals (1,2). These mediators are released by synovial cells and by chondrocytes. In experimental arthritis, clear pericellular activation of chondrocytes is observed based on expression of large amounts of neoepitopes induced by metalloproteinases, which results in pericellular breakdown of the matrix (3), eventually leading to erosion.

Tumor necrosis factor–interleukin‐17 interplay induces S100A8, interleukin‐1β, and matrix metalloproteinases, and drives irreversible cartilage destruction in murine arthritis: Rationale for combination treatment during arthritis

“…Previous studies from our group have shown that S100A8 can stimulate chondrocytes to produce MMPs, to activate latent MMPs, and to degrade the actual cartilage matrix, and these effects were even further enhanced in the presence of IL-1 (46). These previous findings and our current observations in S100A9 Ϫ/Ϫ mice lacking IL-17/TNF-induced NITEGE epitopes suggest that the enhanced up-regulation of S100A8 may very well contribute to the cartilage destruction induced by TNF/IL-17 synergy.…”

Genomic Analysis and Differential Expression of HMG and S100A Family in Human Arthritis: Upregulated Expression of Chemokines, IL-8 and Nitric Oxide by HMGB1

“…For example, (1) increased levels of the S100A family of proteins stimulate chondrocyte hypertrophy and catabolic activity (Cecil and Terkeltaub, 2008;Van Lent et al, 2008;Bian, 2011;Yammani, 2012); (2) Age-related loss of HMGB2 is associated with reduced cellularity and onset of OA. HMGB2 and LEF-1 enhance Wnt signaling and promote superficial zone chondrocyte survival in mice.…”

Calprotectin in rheumatic diseases

“…18,19 Under specific conditions, other cell lines can express and secrete CLP such as endothelial cells, keratinocytes, osteoclasts, chondrocytes, and fibroblast-like synoviocytes. [20][21][22][23][24] ( Figure 1). The precise function of CLP in the immune process has not been unraveled yet.…”