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Anthony J Day - One of the best experts on this subject based on the ideXlab platform.
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TSG-6: A multifunctional protein with anti-inflammatory and tissue-protective properties.
Matrix biology : journal of the International Society for Matrix Biology, 2018Co-Authors: Anthony J Day, Caroline M. MilnerAbstract:Tumor necrosis factor- (TNF) stimulated gene-6 (TSG-6) is an inflammation-associated secreted protein that has been implicated as having important and diverse tissue protective and anti-inflammatory properties, e.g. mediating many of the immunomodulatory and beneficial activities of mesenchymal stem/stromal cells. TSG-6 is constitutively expressed in some tissues, which are either highly metabolically active or subject to challenges from the environment, perhaps providing protection in these contexts. The diversity of its functions are dependent on the binding of TSG-6 to numerous ligands, including matrix molecules such as glycosaminoglycans, as well as immune regulators and growth factors that themselves interact with these linear polysaccharides. It is becoming apparent that TSG-6 can directly affect matrix structure and modulate the way extracellular signalling molecules interact with matrix. In this review, we focus mainly on the literature for TSG-6 over the last 10 years, summarizing its expression, structure, ligand-binding properties, biological functions and highlighting TSG-6's potential as a therapeutic for a broad range of disease indications.
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tumor necrosis factor stimulated gene 6 tsg 6 is constitutively expressed in adult central nervous system cns and associated with astrocyte mediated glial scar formation following spinal cord injury
Journal of Biological Chemistry, 2016Co-Authors: Vivien J Coulsonthomas, Anthony J Day, Mark Lauer, Sara Soleman, Chao Zhao, Vincent C Hascall, James W FawcettAbstract:Tumor necrosis factor (TNF)-stimulated gene-6 (TSG-6) binds to hyaluronan and can reorganize/stabilize its structure, also enhancing the binding of this glycosaminoglycan to its cell surface receptor, CD44. TSG-6 is rapidly up-regulated in response to inflammatory cytokines protecting tissues from the damaging effects of inflammation. Despite TSG-6 treatment having been shown to improve outcomes in an experimental model of traumatic brain injury, TSG-6 expression has not been extensively studied in the central nervous system (CNS). We hereby analyzed the expression profile of TSG-6 in the developing CNS and following injury. We show that TSG-6 is expressed in the rat CNS by GFAP+ and CD44+ astrocytes, solely in the mature brain and spinal cord, and is not present during the development of the CNS. TSG-6−/− mice present a reduced number of GFAP+ astrocytes when compared with the littermate TSG-6+/− mice. TSG-6 expression is drastically up-regulated after injury, and the TSG-6 protein is present within the glial scar, potentially coordinating and stabilizing the formation of this hyaluronan-rich matrix. This study shows that TSG-6 is expressed in the CNS, suggesting a role for TSG-6 in astrocyte activation and tissue repair. We hypothesize that within this context TSG-6 could participate in the formation of the glial scar and confer anti-inflammatory properties. Further studies are required to elucidate the therapeutic potential of targeting TSG-6 after CNS injury to promote its protective effects while reducing the inhibitory properties of the glial scar in axon regeneration.
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196 TSG-6: A Novel Regulator Of VSMC Differentiation and Calcification?
Heart, 2014Co-Authors: Rebecca Taylor, Anthony J Day, Ann E. CanfieldAbstract:Vascular calcification is the formation of bone-like structures in the vessel wall. The pathology is characterised by osteogenic differentiation of vascular smooth muscle cells (VSMCs) and mineralisation of the extracellular matrix. Tumour necrosis factor-stimulated gene-6 (TSG-6) is an inflammation-associated protein that has been implicated in the inhibition of bone formation and thus, we hypothesised, may also influence vascular calcification. Confluent VSMCs were cultured with 3 mM beta-glycerophosphate (BGP) to induce mineralisation. Calcification was confirmed by staining with alizarin red. Osteogenic differentiation was demonstrated by the up-regulation of osteogenic markers (e.g. Runx2 and Msx2) and down-regulation of smooth muscle cell markers (e.g. aSMA) by qPCR. TSG-6 mRNA expression is significantly up-regulated (6-fold, p 86%) confirmed using qPCR and western blotting. Loss of TSG-6 expression significantly increased mineralisation (1.6-fold, p In conclusion, TSG-6 is a novel regulator of vascular calcification, which can modulate both mineralisation and osteogenic differentiation of VSMCs. Our data also suggest that basal TSG-6 expression is crucial in maintaining the VSMC synthetic state, as loss of basal TSG-6 promotes a mature, contractile VSMC phenotype.
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tsg 6 inhibits neutrophil migration via direct interaction with the chemokine cxcl8
Journal of Immunology, 2014Co-Authors: Douglas P Dyer, Anthony J Day, Jennifer M Thomson, Aurelie Hermant, Thomas A Jowitt, Tracy M Handel, Amanda E I Proudfoot, Caroline M. MilnerAbstract:TNF-stimulated gene/protein-6 (TSG-6) is expressed by many different cell types in response to proinflammatory cytokines and plays an important role in the protection of tissues from the damaging consequences of acute inflammation. Recently, TSG-6 was identified as being largely responsible for the beneficial effects of multipotent mesenchymal stem cells, for example in the treatment of animal models of myocardial infarction and corneal injury/allogenic transplant. The protective effect of TSG-6 is due in part to its inhibition of neutrophil migration, but the mechanisms underlying this activity remain unknown. In this study, we have shown that TSG-6 inhibits chemokine-stimulated transendothelial migration of neutrophils via a direct interaction (KD, ∼ 25 nM) between TSG-6 and the glycosaminoglycan binding site of CXCL8, which antagonizes the association of CXCL8 with heparin. Furthermore, we found that TSG-6 impairs the binding of CXCL8 to cell surface glycosaminoglycans and the transport of CXCL8 across an endothelial cell monolayer. In vivo this could limit the formation of haptotactic gradients on endothelial heparan sulfate proteoglycans and, hence, integrin-mediated tight adhesion and migration. We further observed that TSG-6 suppresses CXCL8-mediated chemotaxis of neutrophils; this lower potency effect might be important at sites where there is high local expression of TSG-6. Thus, we have identified TSG-6 as a CXCL8-binding protein, making it, to our knowledge, the first soluble mammalian chemokine-binding protein to be described to date. We have also revealed a potential mechanism whereby TSG-6 mediates its anti-inflammatory and protective effects. This could inform the development of new treatments for inflammation in the context of disease or following transplantation.
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Inter-α-inhibitor Impairs TSG-6-induced Hyaluronan Cross-linking
The Journal of biological chemistry, 2013Co-Authors: Natalia S Baranova, Jan J. Enghild, Anthony J Day, Caroline M. Milner, David Briggs, Simon J. Foulcer, Viranga Tilakaratna, Ralf P. RichterAbstract:Under inflammatory conditions and in the matrix of the cumulus-oocyte complex, the polysaccharide hyaluronan (HA) becomes decorated covalently with heavy chains (HCs) of the serum glycoprotein inter-α-inhibitor (IαI). This alters the functional properties of the HA as well as its structural role within extracellular matrices. The covalent transfer of HCs from IαI to HA is catalyzed by TSG-6 (tumor necrosis factor-stimulated gene-6), but TSG-6 is also known as a HA cross-linker that induces condensation of the HA matrix. Here, we investigate the interplay of these two distinct functions of TSG-6 by studying the ternary interactions of IαI and TSG-6 with well defined films of end-grafted HA chains. We demonstrate that TSG-6-mediated cross-linking of HA films is impaired in the presence of IαI and that this effect suppresses the TSG-6-mediated enhancement of HA binding to CD44-positive cells. Furthermore, we find that the interaction of TSG-6 and IαI in the presence of HA gives rise to two types of complexes that independently promote the covalent transfer of heavy chains to HA. One type of complex interacts very weakly with HA and is likely to correspond to the previously reported covalent HC·TSG-6 complexes. The other type of complex is novel and binds stably but noncovalently to HA. Prolonged incubation with TSG-6 and IαI leads to HA films that contain, in addition to covalently HA-bound HCs, several tightly but noncovalently bound molecular species. These findings have important implications for understanding how the biological activities of TSG-6 are regulated, such that the presence or absence of IαI will dictate its function.
Hans Georg Wisniewski - One of the best experts on this subject based on the ideXlab platform.
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TSG-6 - a double-edged sword for osteoarthritis (OA).
Osteoarthritis and cartilage, 2017Co-Authors: Ching-heng Chou, Philip A. Band, Hans Georg Wisniewski, David E. Attarian, Virginia B. KrausAbstract:Summary Purpose To explore mechanisms underlying the association of TSG-6 with osteoarthritis (OA) progression. Methods TSG-6-mediated heavy chain (HC) transfer (TSG-6 activity) and its association with inflammatory mediators were quantified in knee OA (n=25) synovial fluids (SFs). Paired intact and damaged cartilages from the same individuals (20 tibial and 12 meniscal) were analyzed by qRT-PCR and immunohistochemistry (IHC) for gene and protein expression of TSG-6 and components of Inter-alpha-Inhibitor (IαI) and TSG-6 activity ± spiked in IαI. Primary chondrocyte cultures (n=5) ± IL1β or TNFα were evaluated for gene expression. The effects of TSG-6 activity on cartilage extracellular matrix (ECM) assembly were explored using quantitative hyaluronan (HA)-aggrecan binding assays. Results TSG-6 activity was significantly associated ( R > 0.683, P Conclusions TSG-6 activity is a global inflammatory biomarker in knee OA SF. IαI, supplied from outside cartilage, only penetrates the cartilage surface, restricting TSG-6 activity (HC transfer) to this region. Therefore, unopposed TSG-6 in intermediate and deep regions of OA cartilage could possibly block matrix assembly, leading to futile synthesis and account for increased risk of OA progression.
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TSG-6 activity as a novel biomarker of progression in knee osteoarthritis.
Osteoarthritis and cartilage, 2013Co-Authors: Hans Georg Wisniewski, Elisa Colón, Philip A. Band, Viktoriia Liublinska, Raj Karia, Thomas Stabler, Mukundan Attur, Steven B. Abramson, Virginia B. KrausAbstract:Summary Objective To establish whether there is an association between TSG-6 activity and osteoarthritis progression. Design TSG-6 activity was determined in 132 synovial fluids from patients with OA of the knee, using a novel quantitative TSG-6 activity assay. The association between TSG-6 activities at baseline and four distinct disease progression states, determined at 3-year follow-up, was analyzed using logistic regression. Results There was a statistically significant relationship between TSG-6 activity at baseline and all OA progression states over a 3-year period. Patient knees with TSG-6 activities in the top tenth percentile, compared to the median activity, had an odds ratio (OR) of at least 7.86 (confidence interval (CI) [3.2, 20.5]) for total knee arthroplasty (TKA) within 3 years, and of at least 5.20 (CI [1.8, 13.9]) after adjustment for confounding factors. Receiver operating characteristic (ROC) analysis for knee arthroplasty yielded a cut-off point of 13.3 TSG-6 activity units/ml with the following parameters: area under the curve 0.90 (CI [0.804, 0.996]), sensitivity 0.91 (CI [0.59, 0.99]), specificity 0.82 (CI [0.74, 0.88]) and a negative predictive value (NPV) of 0.99 (CI [0.934, 0.994]). Conclusion The TSG-6 activity is a promising independent biomarker for OA progression. Given the high NPV, this assay may be particularly suitable for identifying patients at low risk of rapid disease progression and to assist in the timing of arthroplasty.
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Transfer of inter-α-inhibitor heavy chains to hyaluronan by surface-linked hyaluronan-TSG-6 complexes
The Journal of biological chemistry, 2008Co-Authors: Elisa Colón, Anastasia Shytuhina, Mary K. Cowman, Philip A. Band, Kristian W. Sanggaard, Jan J. Enghild, Hans Georg WisniewskiAbstract:Abstract Inter-α-inhibitor, TSG-6, and hyaluronan have important functions in fertility and inflammation. Two subunits of inter-α-inhibitor, the heavy chains, form covalent bonds with TSG-6 or hyaluronan in vitro. TSG-6-heavy chain complexes serve as intermediates in the transfer of heavy chains from inter-α-inhibitor to hyaluronan. In vivo, in addition to these complexes, stable ternary complexes of hyaluronan with both TSG-6 and heavy chains have been demonstrated in the ovulatory cumulus oophorus. In our ongoing efforts to characterize the multiple interactions between hyaluronan, TSG-6 and inter-α-inhibitor, we recently characterized the formation of highly stable complexes of TSG-6 with hyaluronan that had been tethered to a solid surface. Here we show that these hyaluronan-TSG-6 complexes are functionally active and transfer heavy chain subunits from inter-α-inhibitor to either free or surface-bound hyaluronan. Transitional hyaluronan-TSG-6-heavy chain complexes do not accumulate in vitro. Our data show the capability for heavy chain transfer by both free TSG-6 and preformed hyaluronan-TSG-6 complexes, suggesting that both might contribute to hyaluronan modification in vivo. Transfer of heavy chains to surface-tethered hyaluronan by either free TSG-6 or surface-tethered hyaluronan-TSG-6 complexes did not affect the CD 44-mediated binding of BW 5147 cells in vitro. We show how TSG-6 and hyaluronan together can deplete inter-α-inhibitor and generate bikunin, as has been observed in sepsis, and discuss the role of TSG-6 in the generation of hyaluronan-heavy chain complexes associated with ovulation, arthritis, and sepsis.
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TSG-6 transfers proteins between glycosaminoglycans via a Ser28-mediated covalent catalytic mechanism
The Journal of biological chemistry, 2008Co-Authors: Kristian W. Sanggaard, Hans Georg Wisniewski, Carsten S. Sonne-schmidt, Toke P. Krogager, Torsten Nygaard Kristensen, Ida B. Thøgersen, Jan J. EnghildAbstract:Abstract Studies of the interaction between Bikunin proteins, tumor necrosis factor-stimulated gene-6 protein (TSG-6), and glycosaminoglycans have revealed a unique catalytic activity where TSG-6/heavy chain 2 transfer heavy chain subunits between glycosaminoglycan chains. The activity is mediated by TSG-6/heavy chain 2 and involves a transient SDS stable interaction between TSG-6 and the heavy chain to be transferred. The focus of this study was to characterize the molecular structure of this cross-link to gain further insight into the catalytic mechanism. The result showed that the C-terminal Asp residue of the heavy chains forms an ester bond to Ser28 β-carbon of TSG-6 suggesting that this residue plays a role during catalysis.
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Up-regulation of cyclooxygenase-2 expression by TSG-6 protein in macrophage cell line.
Biochemical and biophysical research communications, 2005Co-Authors: Catalin Mindrescu, Hans Georg Wisniewski, Jan VilcekAbstract:TNF-stimulated gene 6 (TSG-6) encodes a 35 kDa inducible secreted glycoprotein important in inflammation and female fertility. Previous studies have shown that TSG-6 has anti-inflammatory activity in models of acute and chronic inflammation. In the present study, we show that treatment of the RAW 264.7 murine macrophage cell line with TSG-6 protein up-regulates the expression of inducible cyclooxygenase-2 (COX-2), a key enzyme in inflammation and immune responses. This action of TSG-6 protein was abolished by heat denaturation, trypsin digestion, or anti-TSG-6 antibodies. TSG-6 treatment also resulted in a rapid increase in COX-2 mRNA levels, suggesting that TSG-6 up-regulates COX-2 gene expression. Up-regulation of COX-2 was accompanied by an increase in the production of prostaglandins, especially PGD2. As the PGD2 metabolite, 15-deoxy-Delta12,14-PGJ2, can act as a negative regulator of inflammation, these TSG-6 actions may explain, at least in part, the anti-inflammatory effect of TSG-6 observed in the intact organism.
Jan Vilcek - One of the best experts on this subject based on the ideXlab platform.
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Up-regulation of cyclooxygenase-2 expression by TSG-6 protein in macrophage cell line.
Biochemical and biophysical research communications, 2005Co-Authors: Catalin Mindrescu, Hans Georg Wisniewski, Jan VilcekAbstract:TNF-stimulated gene 6 (TSG-6) encodes a 35 kDa inducible secreted glycoprotein important in inflammation and female fertility. Previous studies have shown that TSG-6 has anti-inflammatory activity in models of acute and chronic inflammation. In the present study, we show that treatment of the RAW 264.7 murine macrophage cell line with TSG-6 protein up-regulates the expression of inducible cyclooxygenase-2 (COX-2), a key enzyme in inflammation and immune responses. This action of TSG-6 protein was abolished by heat denaturation, trypsin digestion, or anti-TSG-6 antibodies. TSG-6 treatment also resulted in a rapid increase in COX-2 mRNA levels, suggesting that TSG-6 up-regulates COX-2 gene expression. Up-regulation of COX-2 was accompanied by an increase in the production of prostaglandins, especially PGD2. As the PGD2 metabolite, 15-deoxy-Delta12,14-PGJ2, can act as a negative regulator of inflammation, these TSG-6 actions may explain, at least in part, the anti-inflammatory effect of TSG-6 observed in the intact organism.
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TSG-6 Protein Binding to Glycosaminoglycans FORMATION OF STABLE COMPLEXES WITH HYALURONAN AND BINDING TO CHONDROITIN SULFATES
The Journal of biological chemistry, 2005Co-Authors: Hans Georg Wisniewski, Catalin Mindrescu, Evan S. Snitkin, Moshe H. Sweet, Jan VilcekAbstract:TSG-6 protein, up-regulated in inflammatory lesions and in the ovary during ovulation, shows anti-inflammatory activity and plays an essential role in female fertility. Studies in murine models of acute inflammation and experimental arthritis demonstrated that TSG-6 has a strong anti-inflammatory and chondroprotective effect. TSG-6 protein is composed of the N-terminal link module that binds hyaluronan and a C-terminal CUB domain, present in a variety of proteins. Interactions between the isolated link module and hyaluronan have been studied extensively, but little is known about the binding of full-length TSG-6 protein to hyaluronan and other glycosaminoglycans. We show that TSG-6 protein and hyaluronan, in a temperature-dependent fashion, form a stable complex that is resistant to dissociating agents. The formation of such stable complexes may underlie the activities of TSG-6 protein in inflammation and fertility, e.g. the TSG-6-dependent cross-linking of hyaluronan in the cumulus cell-oocyte complex during ovulation. Because adhesion to hyaluronan is involved in cell trafficking in inflammatory processes, we also studied the effect of TSG-6 on cell adhesion. TSG-6 binding to immobilized hyaluronan did not interfere with subsequent adhesion of lymphoid cells. In addition to immobilized hyaluronan, full-length TSG-6 also binds free hyaluronan and all chondroitin sulfate isoforms under physiological conditions. These interactions may contribute to the localization of TSG-6 in cartilage and to its chondroprotective and anti-inflammatory effects in models of arthritis.
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Amelioration of collagen-induced arthritis in DBA/1J mice by recombinant TSG-6, a tumor necrosis factor/interleukin-1-inducible protein.
Arthritis and rheumatism, 2000Co-Authors: Catalin Mindrescu, Jan Vilcek, Michael J. Klein, G. J. Thorbecke, Hans Georg WisniewskiAbstract:Objective. To examine the effect of recombinant TSG-6 on collagen-induced arthritis (CIA) in DBA/1J mice. TSG-6 is a tumor necrosis factor (TNF)/ interleukin-1 (IL.1)-inducible hyaluronan-binding protein produced by synovial cells and chondrocytes that is present in synovial fluids of patients with rheumatoid arthritis. Methods. To determine the effect of TSG-6 on chronic inflammatory joint disease, we induced CIA in DBA/1J mice by immunization with bovine type II collagen. Animals were treated with 12 intraperitoneal doses of 200 μg of recombinant TSG-6, beginning 3 days before the expected onset of disease symptoms. Progression of arthritis was monitored by determining the disease incidence, arthritis index, and footpad swelling. Levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen and serum concentrations of IL-6 were determined at various time points. Histologic examination of affected joints was performed ∼20 days after the onset of arthritis. Results. Treatment with recombinant TSG-6 protein had a potent ameliorative effect, manifested by decreases in the disease incidence, arthritis index, and footpad swelling. Histologic examination of affected joints in TSG-6-treated animals revealed little pannus formation and cartilage erosion, features which were conspicuous in control mice. Animals treated with recombinant TSG-6 developed significantly reduced levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen. Conclusion. The antiinflammatory effect of the TNF/IL-1-inducible TSG-6 protein in murine CIA suggests a role for this protein as an endogenous regulator of the inflammatory process.
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TSG-6: An IL-1 /TNF-inducible protein with anti-inflammatory activity
Cytokine & growth factor reviews, 1997Co-Authors: Hans Georg Wisniewski, Jan VilcekAbstract:The pro-inflammatory cytokines IL-1 and TNF-alpha are primary mediators of the acute phase response, the complex reaction of the mammalian organism to infection and injury. Among the genes activated by TNF-alpha and IL-1 in a variety of cells is TNF-stimulated gene 6 (TSG-6). The TSG-6 cDNA encodes a secreted 35 kDa glycoprotein which is abundant in synovial fluids of patients with various forms of arthritis and detectable in serum of patients with different inflammatory or autoimmune disorders. TSG-6 protein consists of two structural domains: a hyaluronan-binding link module, the characteristic domain of the hyaladherin family of proteins, and a C-terminal CUB domain, present in a variety of diverse proteins. TSG-6 forms a stable complex with components of the plasma protein inter-alpha-inhibitor (I[alpha]I), a Kunitz-type serine protease inhibitor. TSG-6 and I(alpha)I synergize to inhibit plasmin, a serine protease involved in the activation of matrix metalloproteinases which are part of the proteolytic cascade associated with inflammation. Recombinant human TSG-6 protein exerts a potent anti-inflammatory effect in a murine model of acute inflammation. Modulation of the proteolytic network associated with inflammatory processes may be a mechanism whereby TSG-6, in cooperation with I(alpha)I, inhibits inflammation. Activation of the TSG-6 gene by pro-inflammatory cytokines, presence of TSG-6 protein in inflammatory lesions and its anti-inflammatory effect suggest a role for TSG-6 in a negative feed-back control of the inflammatory response.
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tnf il 1 inducible protein tsg 6 potentiates plasmin inhibition by inter alpha inhibitor and exerts a strong anti inflammatory effect in vivo
Journal of Immunology, 1996Co-Authors: Hans Georg Wisniewski, Jan Vilcek, J C Hua, D M Poppers, Dwight Naime, Bruce N CronsteinAbstract:TNF-stimulated gene 6 (tsg6), encoding a 35-kDa secretory glycoprotein (TSG-6), is induced in fibroblasts, chondrocytes, synovial cells, and mononuclear cells by the proinflammatory cytokines TNF-alpha and IL-1, or by LPS. Large amounts of TSG-6 protein were found in synovial fluids of patients with rheumatoid arthritis. TSG-6 protein forms a stable complex with components of the serine protease inhibitor, inter-alpha-inhibitor (I alpha I). In this work, we show that TSG-6 potentiates the inhibitory effect of l alpha l on the protease activity of plasmin. The plasmin/plasminogen activator system is important in the protease network associated with inflammation. To test the hypothesis that through their cooperative inhibitory effect on plasmin TSG-6 and l alpha l can modulate the protease network and thus inhibit inflammation, we examined the effect of TSG-6 on experimentally induced inflammation. Human recombinant TSG-6 protein showed a potent anti-inflammatory activity in the murine air pouch model of carrageenan- or IL-1-induced acute inflammation. The inhibitory effect of locally administered TSG-6 on the IL-1-induced cellular infiltration was comparable with that of systemic dexamethasone treatment. Two mutant TSG-6 proteins with single amino acid substitutions close to the N terminus showed a complete or partial loss of anti-inflammatory activity. The anti-inflammatory effect of the TNF/IL-1-inducible TSG-6 protein, along with its ability to inhibit protease action through interaction with l alpha l, suggests that TSG-6 production during inflammation is part of a negative feedback loop operating through the protease network.
Vincent C Hascall - One of the best experts on this subject based on the ideXlab platform.
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tumor necrosis factor stimulated gene 6 tsg 6 is constitutively expressed in adult central nervous system cns and associated with astrocyte mediated glial scar formation following spinal cord injury
Journal of Biological Chemistry, 2016Co-Authors: Vivien J Coulsonthomas, Mark Lauer, Sara Soleman, Chao Zhao, Vincent C Hascall, James W FawcettAbstract:Abstract Tumor necrosis factor (TNF)-stimulated gene-6 (TSG-6) binds to HA and can reorganize/stabilize its structure, also enhancing the binding of this glycosaminoglycan to its cell surface receptor, CD44. TSG-6 is rapidly up-regulated in response to inflammatory cytokines protecting tissues from the damaging effects of inflammation. Despite TSG-6 treatment having been shown to improve outcomes in an experimental model of traumatic brain injury, TSG-6 expression has not been extensively studied in the central nervous system (CNS). We hereby analyzed the expression profile of TSG-6 in the developing CNS and following injury. We show that TSG-6 is expressed in the rat CNS by GFAP+ and CD44+ astrocytes, solely in the mature brain and spinal cord, and is not present during the development of the CNS. TSG-6-/- mice present a reduced number of GFAP+ astrocytes when compared to the littermate TSG-6+/- mice. TSG-6 expression is drastically up-regulated after injury, and the TSG-6 protein is present within the glial scar, potentially coordinating and stabilizing the formation of this HA-rich matrix. This study shows that TSG-6 is expressed in the CNS, suggesting a role for TSG-6 in astrocyte activation and tissue repair. We hypothesize that within this context TSG-6 could participate in the formation of the glial scar and also confer anti-inflammatory properties. Further studies are required to elucidate the therapeutic potential of targeting TSG-6 after CNS injury in order to promote its protective effects while reducing the inhibitory properties of the glial scar in axon regeneration.
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tumor necrosis factor stimulated gene 6 tsg 6 is constitutively expressed in adult central nervous system cns and associated with astrocyte mediated glial scar formation following spinal cord injury
Journal of Biological Chemistry, 2016Co-Authors: Vivien J Coulsonthomas, Anthony J Day, Mark Lauer, Sara Soleman, Chao Zhao, Vincent C Hascall, James W FawcettAbstract:Tumor necrosis factor (TNF)-stimulated gene-6 (TSG-6) binds to hyaluronan and can reorganize/stabilize its structure, also enhancing the binding of this glycosaminoglycan to its cell surface receptor, CD44. TSG-6 is rapidly up-regulated in response to inflammatory cytokines protecting tissues from the damaging effects of inflammation. Despite TSG-6 treatment having been shown to improve outcomes in an experimental model of traumatic brain injury, TSG-6 expression has not been extensively studied in the central nervous system (CNS). We hereby analyzed the expression profile of TSG-6 in the developing CNS and following injury. We show that TSG-6 is expressed in the rat CNS by GFAP+ and CD44+ astrocytes, solely in the mature brain and spinal cord, and is not present during the development of the CNS. TSG-6−/− mice present a reduced number of GFAP+ astrocytes when compared with the littermate TSG-6+/− mice. TSG-6 expression is drastically up-regulated after injury, and the TSG-6 protein is present within the glial scar, potentially coordinating and stabilizing the formation of this hyaluronan-rich matrix. This study shows that TSG-6 is expressed in the CNS, suggesting a role for TSG-6 in astrocyte activation and tissue repair. We hypothesize that within this context TSG-6 could participate in the formation of the glial scar and confer anti-inflammatory properties. Further studies are required to elucidate the therapeutic potential of targeting TSG-6 after CNS injury to promote its protective effects while reducing the inhibitory properties of the glial scar in axon regeneration.
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Tumor Necrosis Factor-stimulated Gene-6 (TSG-6) Amplifies Hyaluronan Synthesis by Airway Smooth Muscle Cells
The Journal of biological chemistry, 2012Co-Authors: Mark E. Lauer, Shadi Swaidani, Georgiana Cheng, Mark A. Aronica, Paul H. Weigel, Vincent C HascallAbstract:We tested the hypothesis that the artificial addition of heavy chains from inter-α-inhibitor to hyaluronan (HA), by adding recombinant TSG-6 (TNF-stimulated gene-6) to the culture medium of murine airway smooth muscle (MASM) cells, would enhance leukocyte binding to HA cables produced in response to poly(I:C). As predicted, the addition of heavy chains to HA cables enhanced leukocyte adhesion to these cables, but it also had several unexpected effects. (i) It produced thicker, more pronounced HA cables. (ii) It increased the accumulation of HA in the cell-associated matrix. (iii) It decreased the amount of HA in the conditioned medium. Importantly, these effects were observed only when TSG-6 was administered in the presence of poly(I:C), and TSG-6 did not exert any effect on its own. Increased HA synthesis occurred during active, poly(I:C)-induced HA synthesis and did not occur when TSG-6 was added after poly(I:C)-induced HA synthesis was complete. MASM cells derived from TSG-6−/−, HAS1/3−/−, and CD44−/− mice amplified HA synthesis in response to poly(I:C) + TSG-6 in a manner similar to WT MASM cells, demonstrating that they are expendable in this process. We conclude that TSG-6 increases the accumulation of HA in the cell-associated matrix, partially by preventing its dissolution from the cell-associated matrix into the conditioned medium, but primarily by inducing HA synthesis.
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TSG-6 Protein Is Crucial for the Development of Pulmonary Hyaluronan Deposition, Eosinophilia, and Airway Hyperresponsiveness in a Murine Model of Asthma
The Journal of biological chemistry, 2012Co-Authors: Shadi Swaidani, Vincent C Hascall, Katalin Mikecz, Georgiana Cheng, Mark E. Lauer, Manisha Sharma, Mark A. AronicaAbstract:Hyaluronan (HA) deposition is often correlated with mucosal inflammatory responses, where HA mediates both protective and pathological responses. By modifying the HA matrix, Tnfip6 (TNF-α-induced protein-6; also known as TSG-6 (TNF-stimulated gene-6)) is thought to potentiate anti-inflammatory and anti-plasmin effects that are inhibitory to leukocyte extravasation. In this study, we examined the role of endogenous TSG-6 in the pathophysiological responses associated with acute allergic pulmonary inflammation. Compared with wild-type littermate controls, TSG-6−/− mice exhibited attenuated inflammation marked by a significant decrease in pulmonary HA concentrations measured in the bronchoalveolar lavage and lung tissue. Interestingly, despite the equivalent induction of both humoral and cellular Th2 immunity and the comparable levels of cytokines and chemokines typically associated with eosinophilic pulmonary inflammation, airway eosinophilia was significantly decreased in TSG-6−/− mice. Most importantly, contrary to their counterpart wild-type littermates, TSG-6−/− mice were resistant to the induction of airway hyperresponsiveness and manifested improved lung mechanics in response to methacholine challenge. Our study demonstrates that endogenous TSG-6 is dispensable for the induction of Th2 immunity but is essential for the robust increase in pulmonary HA deposition, propagation of acute eosinophilic pulmonary inflammation, and development of airway hyperresponsiveness. Thus, TSG-6 is implicated in the experimental murine model of allergic pulmonary inflammation and is likely to contribute to the pathogenesis of asthma.
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TSG-6 protein, a negative regulator of inflammatory arthritis, forms a ternary complex with murine mast cell tryptases and heparin.
The Journal of biological chemistry, 2011Co-Authors: Gyorgy Nagyeri, Vincent C Hascall, Marianna Radacs, Sheida Ghassemi-nejad, Beata Tryniszewska, Katalin Olasz, Gabor Hutas, Zsuzsa Gyorfy, Tibor T. Glant, Katalin MikeczAbstract:TSG-6 (TNF-α-stimulated gene/protein 6), a hyaluronan (HA)-binding protein, has been implicated in the negative regulation of inflammatory tissue destruction. However, little is known about the tissue/cell-specific expression of TSG-6 in inflammatory processes, due to the lack of appropriate reagents for the detection of this protein in vivo. Here, we report on the development of a highly sensitive detection system and its use in cartilage proteoglycan (aggrecan)-induced arthritis, an autoimmune murine model of rheumatoid arthritis. We found significant correlation between serum concentrations of TSG-6 and arthritis severity throughout the disease process, making TSG-6 a better biomarker of inflammation than any of the other arthritis-related cytokines measured in this study. TSG-6 was present in arthritic joint tissue extracts together with the heavy chains of inter-α-inhibitor (IαI). Whereas TSG-6 was broadly detectable in arthritic synovial tissue, the highest level of TSG-6 was co-localized with tryptases in the heparin-containing secretory granules of mast cells. In vitro, TSG-6 formed complexes with the tryptases murine mast cell protease-6 and -7 via either heparin or HA. In vivo TSG-6-tryptase association could also be detected in arthritic joint extracts by co-immunoprecipitation. TSG-6 has been reported to suppress inflammatory tissue destruction by enhancing the serine protease-inhibitory activity of IαI against plasmin. TSG-6 achieves this by transferring heavy chains from IαI to HA, thus liberating the active bikunin subunit of IαI. Because bikunin is also present in mast cell granules, we propose that TSG-6 can promote inhibition of tryptase activity via a mechanism similar to inhibition of plasmin.
Caroline M. Milner - One of the best experts on this subject based on the ideXlab platform.
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TSG-6: A multifunctional protein with anti-inflammatory and tissue-protective properties.
Matrix biology : journal of the International Society for Matrix Biology, 2018Co-Authors: Anthony J Day, Caroline M. MilnerAbstract:Tumor necrosis factor- (TNF) stimulated gene-6 (TSG-6) is an inflammation-associated secreted protein that has been implicated as having important and diverse tissue protective and anti-inflammatory properties, e.g. mediating many of the immunomodulatory and beneficial activities of mesenchymal stem/stromal cells. TSG-6 is constitutively expressed in some tissues, which are either highly metabolically active or subject to challenges from the environment, perhaps providing protection in these contexts. The diversity of its functions are dependent on the binding of TSG-6 to numerous ligands, including matrix molecules such as glycosaminoglycans, as well as immune regulators and growth factors that themselves interact with these linear polysaccharides. It is becoming apparent that TSG-6 can directly affect matrix structure and modulate the way extracellular signalling molecules interact with matrix. In this review, we focus mainly on the literature for TSG-6 over the last 10 years, summarizing its expression, structure, ligand-binding properties, biological functions and highlighting TSG-6's potential as a therapeutic for a broad range of disease indications.
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tsg 6 inhibits neutrophil migration via direct interaction with the chemokine cxcl8
Journal of Immunology, 2014Co-Authors: Douglas P Dyer, Anthony J Day, Jennifer M Thomson, Aurelie Hermant, Thomas A Jowitt, Tracy M Handel, Amanda E I Proudfoot, Caroline M. MilnerAbstract:TNF-stimulated gene/protein-6 (TSG-6) is expressed by many different cell types in response to proinflammatory cytokines and plays an important role in the protection of tissues from the damaging consequences of acute inflammation. Recently, TSG-6 was identified as being largely responsible for the beneficial effects of multipotent mesenchymal stem cells, for example in the treatment of animal models of myocardial infarction and corneal injury/allogenic transplant. The protective effect of TSG-6 is due in part to its inhibition of neutrophil migration, but the mechanisms underlying this activity remain unknown. In this study, we have shown that TSG-6 inhibits chemokine-stimulated transendothelial migration of neutrophils via a direct interaction (KD, ∼ 25 nM) between TSG-6 and the glycosaminoglycan binding site of CXCL8, which antagonizes the association of CXCL8 with heparin. Furthermore, we found that TSG-6 impairs the binding of CXCL8 to cell surface glycosaminoglycans and the transport of CXCL8 across an endothelial cell monolayer. In vivo this could limit the formation of haptotactic gradients on endothelial heparan sulfate proteoglycans and, hence, integrin-mediated tight adhesion and migration. We further observed that TSG-6 suppresses CXCL8-mediated chemotaxis of neutrophils; this lower potency effect might be important at sites where there is high local expression of TSG-6. Thus, we have identified TSG-6 as a CXCL8-binding protein, making it, to our knowledge, the first soluble mammalian chemokine-binding protein to be described to date. We have also revealed a potential mechanism whereby TSG-6 mediates its anti-inflammatory and protective effects. This could inform the development of new treatments for inflammation in the context of disease or following transplantation.
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Inter-α-inhibitor Impairs TSG-6-induced Hyaluronan Cross-linking
The Journal of biological chemistry, 2013Co-Authors: Natalia S Baranova, Jan J. Enghild, Anthony J Day, Caroline M. Milner, David Briggs, Simon J. Foulcer, Viranga Tilakaratna, Ralf P. RichterAbstract:Under inflammatory conditions and in the matrix of the cumulus-oocyte complex, the polysaccharide hyaluronan (HA) becomes decorated covalently with heavy chains (HCs) of the serum glycoprotein inter-α-inhibitor (IαI). This alters the functional properties of the HA as well as its structural role within extracellular matrices. The covalent transfer of HCs from IαI to HA is catalyzed by TSG-6 (tumor necrosis factor-stimulated gene-6), but TSG-6 is also known as a HA cross-linker that induces condensation of the HA matrix. Here, we investigate the interplay of these two distinct functions of TSG-6 by studying the ternary interactions of IαI and TSG-6 with well defined films of end-grafted HA chains. We demonstrate that TSG-6-mediated cross-linking of HA films is impaired in the presence of IαI and that this effect suppresses the TSG-6-mediated enhancement of HA binding to CD44-positive cells. Furthermore, we find that the interaction of TSG-6 and IαI in the presence of HA gives rise to two types of complexes that independently promote the covalent transfer of heavy chains to HA. One type of complex interacts very weakly with HA and is likely to correspond to the previously reported covalent HC·TSG-6 complexes. The other type of complex is novel and binds stably but noncovalently to HA. Prolonged incubation with TSG-6 and IαI leads to HA films that contain, in addition to covalently HA-bound HCs, several tightly but noncovalently bound molecular species. These findings have important implications for understanding how the biological activities of TSG-6 are regulated, such that the presence or absence of IαI will dictate its function.
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TSG-6, a new protein ligand for CXCL8, modulates the activity of this pro-inflammatory chemokine (54.12)
Journal of Immunology, 2011Co-Authors: Douglas P Dyer, Caroline M. Milner, Anthony J DayAbstract:TSG-6, a 35 kDa secreted protein, is expressed during inflammation (e.g. in the cartilage/synovium of arthritis patients) and delays the onset/reduces the severity of joint damage in models of inflammatory arthritis. For example, TSG-6-/- mice with proteoglycan-induced arthritis exhibit elevated neutrophil invasion and protease activity in the paw joints compared to controls. The aim of this study is to investigate potential mechanisms for the anti-inflammatory and chondroprotective effects of TSG-6, focusing on its interaction with CXCL8. This chemokine is known to promote neutrophil migration and to induce matrix metalloproteinase (MMP) secretion by endothelial cells. Using plate-based assays and surface plasmon resonance we have demonstrated that TSG-6 binds to CXCL8 in a pH-dependent manner and that TSG-6 can inhibit the interaction of CXCL8 with heparin. Since the sequestration of CXCL8 by endothelial glycosaminoglycans (e.g. heparan sulphate) contributes to its pro-migratory activity, this might represent one mechanism through which TSG-6 limits neutrophil extravasation. We have also shown, using gelatin zymography, that TSG-6 can block the CXCL8-mediated production of active MMPs by endothelial cells. MMPs have been implicated in the destruction of articular cartilage in arthritis, where they occur at elevated levels (e.g. in RA synovial fluids). Inhibition of the expression and/or activation of MMPs could, therefore, contribute to TSG-6’s chondroprotective effect.
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TSG-6 inhibits osteoclast activity via an autocrine mechanism and is functionally synergistic with osteoprotegerin.
Arthritis and rheumatism, 2011Co-Authors: David J Mahoney, Anthony J Day, Catherine Swales, Nicholas A. Athanasou, Michele Bombardieri, Costantino Pitzalis, K Kliskey, Mohammed Sharif, Caroline M. Milner, Afsie SabokbarAbstract: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.
