Objective: TSG-6 (the product of tumor necrosis factor [TNF]-stimulated gene 6) has a potent inhibitory effect on RANKL-mediated bone erosion. The aim of this study was to compare the activity of TSG-6 with that of osteoprotegerin (OPG) and to investigate its role as an autocrine modulator of cytokine-mediated osteoclast formation/activation. We also determined TSG-6 expression in inflammatory joint disease.
Methods: The effects of TSG-6, OPG, and the inflammation mediators TNFα, interleukin-1 (IL-1), and IL-6 on the formation of osteoclasts from peripheral blood mononuclear cells and synovial fluid (SF) macrophages were determined by tartrate-resistant acid phosphatase staining. Lacunar resorption and filamentous actin ring formation were measured as indicators of osteoclast activity. The amount of TSG-6 in culture media or SF was quantified by enzyme-linked immunosorbent assay, and expression of TSG-6 in synovial tissue was assessed by immunohistochemistry.
Results: TSG-6 acted in synergy with OPG to inhibit RANKL-mediated bone resorption and was produced by osteoclast precursors and mature osteoclasts in response to TNFα, IL-1, and IL-6. Expression of TSG-6 correlated with inhibition of lacunar resorption; this effect was ameliorated by an anti-TSG-6 antibody. The level of TSG-6 protein was determined in SF from patients with various arthritides; it was highest in patients with inflammatory conditions such as rheumatoid arthritis, in which it correlated with the amount of TSG-6 immunostaining in the synovium. TSG-6 inhibited the activation but not the formation of osteoclasts from SF macrophages.
Conclusion: In the presence of inflammatory cytokines, osteoclasts produced TSG-6 at concentrations that are sufficient to inhibit lacunar resorption. This may represent an autocrine mechanism to limit the degree of bone erosion during joint inflammation.
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http://dx.doi.org/10.1002/art.30201 | DOI Listing |
iScience
December 2024
Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Kidney tissue injury in renal artery stenosis (RAS) involves inflammation, endoplasmic reticulum stress (ERS), and mitochondria damage. Tumor necrosis factor-stimulated gene-6 (TSG-6), an endogenous reparative molecule, may decrease ERS and improve renal function. To assess its impact on the stenotic murine kidney, we injected TSG-6 or vehicle for two weeks in mice with RAS.
View Article and Find Full Text PDFJ Orthop Surg Res
December 2024
Associated Tissue Bank, Faculty of Medicine, P.J. Safarik University and L. Pasteur University Hospital in Kosice, Tr. SNP 1, Kosice, 04011, Slovakia.
Background: Although osteoarthritis (OA) is the most prevalent form of arthritis, there is still no effective treatment capable of combining immunomodulatory effects with cartilage repair. Extracellular vesicles (EVs) represent a promising new generation of cell-free therapies for OA. Blood-derived products, including plasma, are an easily available and abundant source of EVs with anti-inflammatory and regenerative properties.
View Article and Find Full Text PDFmSystems
November 2024
Department of Pediatrics, Critical Care, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, Arkansas, USA.
A consistent feature of lung injury is a rapid and sustained accumulation of hyaluronan (HA). The rodent gut-dwelling nematode (Nb) induces tissue damage as it migrates through the lungs. Type 2 immune responses are essential for the repair of the lungs, hence Nb infection is a well-established model to study immune-mediated lung repair.
View Article and Find Full Text PDFStem Cells
November 2024
Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio.
Introduction: Mesenchymal stromal cells (MSCs) can modulate immune responses and suppress inflammation in autoimmune diseases. Although their safety has been established in clinical trials, the efficacy of MSCs is inconsistent due to variability in potency among different preparations and limited specificity in targeting mechanisms driving autoimmune diseases.
Methods: We utilized High-Dimensional Design of Experiments methodology to identify factor combinations that modulate gene expression by MSCs to mitigate inflammation.
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