OBJECTIVES: Our previous studies have demonstrated that the Damage Associated Molecular Pattern (DAMP) protein, S100A4, is overexpressed in the involved skin and peripheral blood of patients with SSc. It is associated with skin and lung involvement, and disease activity. By contrast, lack of S100A4 prevented the development of experimental dermal fibrosis. Herein we aimed to evaluate the effect of murine anti-S100A4 mAb 6B12 in the treatment of preestablished experimental dermal fibrosis. METHODS: The effects of 6B12 were assessed at therapeutic dosages in a modified bleomycin-induced dermal fibrosis mouse model by evaluating fibrotic (dermal thickness, proliferation of myofibroblasts, hydroxyproline content, phosphorylated Smad3-positive cell count) and inflammatory (leukocytes infiltrating the lesional skin, systemic levels of selected cytokines and chemokines) outcomes, and transcriptional profiling (RNA sequencing). RESULTS: Treatment with 7.5 mg/kg 6B12 attenuated and might even reduce pre-existing dermal fibrosis induced by bleomycin as evidenced by reduction in dermal thickness, myofibroblast count and collagen content. These antifibrotic effects were mediated by the downregulation of TGF-β/Smad signalling and partially by reducing the number of leukocytes infiltrating the lesional skin and decrease in the systemic levels of IL-1α, eotaxin, CCL2 and CCL5. Moreover, transcriptional profiling demonstrated that 7.5 mg/kg 6B12 also modulated several profibrotic and proinflammatory processes relevant to the pathogenesis of SSc. CONCLUSION: Targeting S100A4 by the 6B12 mAb demonstrated potent antifibrotic and anti-inflammatory effects on bleomycin-induced dermal fibrosis and provided further evidence for the vital role of S100A4 in the pathophysiology of SSc.

• Keywords
• 6B12, S100A4, SSc, established dermal fibrosis, monoclonal antibody, treatment,
• MeSH
• Alarmins * MeSH
• Bleomycin toxicity   MeSH
• Fibrosis MeSH
• Skin * pathology   MeSH
• Humans MeSH
• Disease Models, Animal MeSH
• Antibodies, Monoclonal pharmacology   MeSH
• Mice MeSH
• S100 Calcium-Binding Protein A4 genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alarmins * MeSH
• Bleomycin MeSH
• Antibodies, Monoclonal MeSH
• S100 Calcium-Binding Protein A4 MeSH
• S100A4 protein, human MeSH Browser

S100A11 (calgizzarin), a member of S100 family, is associated with several autoimmune diseases, including rheumatoid arthritis (RA). Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of RA and in the externalization of some S100 family members. Therefore, we aimed to determine the association between S100A11 and NETs in RA. For this purpose, the levels of S100A11 and NETosis markers were detected in the RA synovial fluid by immunoassays. The expression of S100A11 by neutrophils in the RA synovial tissue was assessed. Neutrophils isolated from peripheral blood were exposed to S100A11 or stimulated to release NETs. The levels of NETosis- and inflammation-associated proteins were analysed by immunoassays. NETs were visualized by immunofluorescence. We showed that S100A11 was expressed by the neutrophils in the RA synovial tissue. Moreover, S100A11 in the RA synovial fluid correlated with several NETosis markers. In vitro, S100A11 was abundantly released by neutrophils undergoing NETosis compared to untreated cells (p < 0.001). Extracellular S100A11 increased the secretion of IL-6 (p < 0.05) and TNF (p < 0.05) by neutrophils but did not induce NETosis. This study demonstrates, for the first time, that the release of S100A11 is dependent on NETosis and that extracellular S100A11 augments the inflammatory response by inducing pro-inflammatory cytokines in neutrophils.

• MeSH
• Adult MeSH
• Extracellular Traps metabolism   MeSH
• Interleukin-6 metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Neutrophils metabolism   pathology   MeSH
• S100 Proteins metabolism   MeSH
• Arthritis, Rheumatoid metabolism   pathology   MeSH
• Aged MeSH
• Synovial Fluid metabolism   MeSH
• Tumor Necrosis Factor-alpha metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• IL6 protein, human MeSH Browser
• Interleukin-6 MeSH
• S100 Proteins MeSH
• S100A11 protein, human MeSH Browser
• Tumor Necrosis Factor-alpha MeSH

BACKGROUND: S100A4 is a member of calcium binding S100 protein family well known for its role in cancer progression and metastasis. Nevertheless, S100A4 also serves as a negative regulator of bone formation. Dickkopf-1 (DKK-1), marker of bone remodelling, is also implicated in the process of syndesmophyte formation in ankylosing spondylitis. The aim of our study was to evaluate plasma levels of S100A4 in patients with axial spondyloarthritis and to determine the potential association of S100A4 with disease severity, clinical manifestations and with bone changes in a cross-sectional study. METHODS: Fifty-eight patients with axial spondyloarthritis and 40 healthy controls were studied. Biological samples were analysed for S100A4 and Dickkopf-1. Disease activity was assessed according to the Bath Ankylosing Spondylitis Disease Activity Index. C-reactive protein (CRP) was used as a marker of inflammation. Radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). RESULTS: The plasma levels of S100A4 were significantly higher in patients with axial spondyloarthritis compared to heathy controls (p < 0.0001). The levels of S100A4 were higher in early stages of the disease and lower in patients with the presence of syndesmophytes (p = 0.009). Furthermore, we found weak but significant inverse correlation of plasma S100A4 with the mSASSS (r = - 0.363, p = 0.030). Levels of S100A4 were negatively associated with disease duration (r = - 0.404, p = 0.002) and positively with Dickkopf-1 binding capacity (r = 0.312, p = 0.023). CONCLUSIONS: This is the first study showing elevated circulating levels of S100A4 in patients with axial spondyloarthritis, particularly in early stages of the disease prior to spinal involvement, and its significantly lower levels in patients with syndesmophytes. The role of S100A4 in the pathogenesis of axial spondyloarthritis can be suggested.

• Keywords
• Axial spondyloarthritis, Disease duration, Disease severity, S100A4, Syndesmophyte,
• Publication type
• Journal Article MeSH

S100 proteins are currently being investigated as potential diagnostic and prognostic biomarkers of several cancers and inflammatory diseases. The aims of this study were to analyse the plasma levels of S100A4, S100A8/9 and S100A12 in patients with incomplete systemic lupus erythematosus (iSLE), in patients with established SLE and in healthy controls (HCs) and to investigate the potential utility of the S100 proteins as diagnostic or activity-specific biomarkers in SLE. Plasma levels were measured by ELISA in a cross-sectional cohort study of 44 patients with SLE, 8 patients with iSLE and 43 HCs. Disease activity was assessed using the SLEDAI-2K. The mean levels of all S100 proteins were significantly higher in SLE patients compared to HCs. In iSLE patients, the levels of S100A4 and S100A12 but not S100A8/9 were also significantly higher compared to HCs. There were no significant differences in S100 levels between the iSLE and SLE patients. Plasma S100 proteins levels effectively discriminated between SLE patients and HCs. The area under the curve (AUC) for S100A4, S100A8/9 and S100A12 plasma levels was 0.989 (95% CI 0.976-1.000), 0.678 (95% CI 0.563-0.792) and 0.807 (95% CI 0.715-0.899), respectively. S100 levels did not differentiate between patients with high and low disease activity. Only the S100A12 levels were significantly associated with SLEDAI-2K and with cSLEDAI-2K. S100 proteins were significantly higher in SLE patients compared HCs and particularly S100A4 could be proposed as a potential diagnostic biomarker for SLE.

• Keywords
• Biomarkers, Disease activity, S100 proteins, SLE,
• MeSH
• Adult MeSH
• Calgranulin A blood   MeSH
• Calgranulin B blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• S100A12 Protein blood   MeSH
• S100 Proteins blood   MeSH
• Cross-Sectional Studies MeSH
• S100 Calcium-Binding Protein A4 blood   MeSH
• Case-Control Studies MeSH
• Lupus Erythematosus, Systemic blood   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Calgranulin A MeSH
• Calgranulin B MeSH
• S100A12 Protein MeSH
• S100 Proteins MeSH
• S100 Calcium-Binding Protein A4 MeSH
• S100A12 protein, human MeSH Browser
• S100A4 protein, human MeSH Browser
• S100A8 protein, human MeSH Browser
• S100A9 protein, human MeSH Browser

BACKGROUND: Calgizzarin (S100A11) is a member of the S100 protein family that acts in different tumors by regulating a number of biologic functions. Recent data suggest its association with low-grade inflammation in osteoarthritis (OA). The aim of our study is to compare S100A11 expression in the synovial tissues, synovial fluid and serum of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to characterize the potential association between S100A11 and disease activity. METHODS: S100A11 protein expression was detected in synovial tissue from patients with RA (n = 6) and patients with OA (n = 6) by immunohistochemistry and immunofluorescence. Serum and synovial fluid S100A11 levels were measured by ELISA in patients with RA (n = 40) and patients with OA (n = 34). Disease activity scores in 28 joints based on C-reactive protein (DAS28-CRP) were used to assess disease activity. Cytokine content in peripheral blood mononuclear cells (PBMCs), synovial fibroblasts (SFs) and synovial fluid was analysed by ELISA, western blotting or cytometric bead array. RESULTS: S100A11 expression was significantly up-regulated in the synovial lining and sublining layers (p < 0.01) and vessels (p < 0.05) of patients with RA compared to patients with OA, and was associated with fibroblasts and T cells. S100A11 was significantly increased in synovial fluid (p < 0.0001) but not in serum (p = 0.158) from patients with RA compared to patients with OA when adjusted for age and sex. Synovial fluid S100A11 correlated with DAS28 (r = 0.350, p = 0.027), serum CRP (r = 0.463, p = 0.003), synovial fluid leukocyte count (r = 0.677, p < 0.001), anti-cyclic citrullinated peptide antibodies (anti-CCP) (r = 0.424, p = 0.006) and IL-6 (r = 0.578, p = 0.002) and IL-8 (r = 0.740, p < 0.001) in synovial fluid from patients with RA. PBMCs and SFs isolated from patients with RA synthesized and spontaneously secreted higher levels of S100A11 in comparison with PBMCs and SFs from patients with OA (p = 0.011 and 0.03, respectively). S100A11 stimulated the production of the pro-inflammatory cytokine IL-6 by PBMCs (p < 0.05) and SFs (p < 0.01). CONCLUSIONS: Our data provide the first evidence of S100A11 up-regulation and its association with inflammation and disease activity in patients with RA.

• Keywords
• Calgizzarin, Disease activity, Inflammation, Rheumatoid arthritis, S100 proteins,
• MeSH
• Biomarkers MeSH
• Adult MeSH
• Cells, Cultured MeSH
• Middle Aged MeSH
• Humans MeSH
• Inflammation Mediators metabolism   MeSH
• Disease Progression * MeSH
• S100 Proteins metabolism   MeSH
• Cross-Sectional Studies MeSH
• Arthritis, Rheumatoid diagnosis   metabolism   MeSH
• Aged MeSH
• Synovial Fluid metabolism   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biomarkers MeSH
• Inflammation Mediators MeSH
• S100 Proteins MeSH
• S100A11 protein, human MeSH Browser