Isolation and characterization of eight tumor necrosis factor-induced gene sequences from human fibroblasts

Identification of TNFAIP6 as a reliable prognostic indicator of low-grade glioma

Glioma is the most common primary malignant tumor in the brain, characterizing by high disability rate and high recurrence rate. Although low-grade glioma (LGG) has a relative benign biological behavior, the prognosis of LGG patients still varies greatly. Glioma stem cells (GSCs) are considered as the chief offenders of glioma cell proliferation, invasion and resistance to therapies. Our study screened a series of glioma stem cell-related genes (GSCRG) based on mDNAsi and WCGNA, and finally established a reliable single-gene prognostic model through 101 combinations of 10 machine learning methods. Our result suggested that the expression level of TNFAIP6 is negatively correlated with the prognosis of LGG patients, which may be the result of pro-cancer signaling pathways activation and immunosuppression. In general, this study revealed that TNFAIP6 is a robust and valuable prognostic factor in LGG, and may be a new target for LGG treatment.

TSG-6 (Tumor Necrosis Factor-α-Stimulated Gene/Protein-6): An Emerging Remedy for Renal Inflammation

The inflammatory response is a major pathological feature in most kidney diseases and often evokes compensatory mechanisms. Recent evidence suggests that TSG-6 (tumor necrosis factor-α-stimulated gene/protein-6) plays a pivotal role in anti-inflammation in various renal diseases, including immune-mediated and nonimmune-mediated renal diseases. TSG-6 has a diverse repertoire of anti-inflammatory functions: it potentiates antiplasmin activity of IαI (inter-α-inhibitor) by binding to its light chain, crosslinks hyaluronan to promote its binding to cell surface receptor CD44, and thereby regulate the migration and adhesion of lymphocytes, inhibits chemokine-stimulated transendothelial migration of neutrophils by directly interacting with the glycosaminoglycan binding site of CXCL8 (CXC motif chemokine ligand-8), and upregulates COX-2 (cyclooxygenase-2) to produce anti-inflammatory metabolites. Hopefully, further developments can target this anti-inflammatory molecule to the kidney and harness its remedial properties. This review provides an overview of the emerging role of TSG-6 in blunting renal inflammation.

Noncovalent hyaluronan crosslinking by TSG-6: Modulation by heparin, heparan sulfate, and PRG4

The size, conformation, and organization of the glycosaminoglycan hyaluronan (HA) affect its interactions with soluble and cell surface-bound proteins. HA that is induced to form stable networks has unique biological properties relative to unmodified soluble HA. AlphaLISA assay technology offers a facile and general experimental approach to assay protein-mediated networking of HA in solution. Connections formed between two end-biotinylated 50 kDa HA (bHA) chains can be detected by signal arising from streptavidin-coated donor and acceptor beads being brought into close proximity when the bHA chains are bridged by proteins. We observed that incubation of bHA with the protein TSG-6 (tumor necrosis factor alpha stimulated gene/protein 6, TNFAIP/TSG-6) leads to dimerization or higher order multimerization of HA chains in solution. We compared two different heparin (HP) samples and two heparan sulfate (HS) samples for the ability to disrupt HA crosslinking by TSG-6. Both HP samples had approximately three sulfates per disaccharide, and both were effective in inhibiting HA crosslinking by TSG-6. HS with a relatively high degree of sulfation (1.75 per disaccharide) also inhibited TSG-6 mediated HA networking, while HS with a lower degree of sulfation (0.75 per disaccharide) was less effective. We further identified Proteoglycan 4 (PRG4, lubricin) as a TSG-6 ligand, and found it to inhibit TSG-6-mediated HA crosslinking. The effects of HP, HS, and PRG4 on HA crosslinking by TSG-6 were shown to be due to HP/HS/PRG4 inhibition of HA binding to the Link domain of TSG-6. Using the AlphaLISA platform, we also tested other HA-binding proteins for ability to create HA networks. The G1 domain of versican (VG1) effectively networked bHA in solution but required a higher concentration than TSG-6. Cartilage link protein (HAPLN1) and the HA binding protein segment of aggrecan (HABP, G1-IGD-G2) showed only low and variable magnitude HA networking effects. This study unambiguously demonstrates HA crosslinking in solution by TSG-6 and VG1 proteins, and establishes PRG4, HP and highly sulfated HS as modulators of TSG-6 mediated HA crosslinking.

Correlation of plasma TSG-6 with cardiac function, myocardial fibrosis, and prognosis in dilated cardiomyopathy patients with heart failure

OBJECTIVES

Tumor necrosis factor α stimulated gene 6 (TSG-6) protein is an inflammation-inducing protein. In recent years, TSG-6 protein has been found to play an anti-inflammatory and anti-fibrosis role in a variety of disease models. The level of TSG-6 protein in circulating blood is considered to be a biological indicator for the evaluation of acute coronary syndrome, severe infection, and other diseases, and it is closely related to the prognosis. The clinical correlation between TSG-6 protein and dilated cardiomyopathy (DCM) patients with heart failure has not been reported. This study aims to investigate the changes of plasma TSG-6 protein levels in cardiomyopathy patients with heart failure and its correlation with cardiac function, myocardial fibrosis, and prognosis.

METHODS

Based on the prospective studies, a number of 90 DCM patients with heart failure were selected as a DCM heart failure group from Dec.1, 2019 to Sept.1, 2020. Thirty-nine healthy people were served as a control group. Plasma TSG-6, Collagen Ⅰ, Collagen III, and α-smooth muscle actin (α-SMA) were measured with ELISA test. Echocardiography was used to evaluate the structure and function of the heart. DCM patients with heart failure were followed up for 3 months. The patients were assigned into 2 groups according to whether they had major adverse cardiovascular events (MACE). The general clinical data, plasma TSG-6, Collagen Ⅰ, Collagen III, and α-SMA protein levels were compared between the control group and the DCM heart failure group. At the same time, the correlation between plasma TSG-6 protein level and cardiac function grade, myocardial fibrosis or prognosis of patients in the DCM heart failure group was analyzed.

RESULTS

Compared with the control group, the heart rate, TSG-6, Collagen Ⅰ, Collage III, α-SMA, hemoglobin, atrial natriuretic peptide (NT-proBNP), hypersensitive C-reactive protein, aspartate aminotransferase, serum creatinine, lactate dehydrogenase, and left ventricular end diastolic diameter (LVEDD) increased significantly (all P<0.001). High-density lipoprotein, left ventricular short axis shortening rate (LVFS), and left ventricular ejection fraction (LVEF) decreased significantly in the DCM heart failure group (all P<0.001). Plasma levels of TSG-6 were positively correlated with NT-proBNP, Collagen Ⅰ, Collagen III, α-SMA, and LVEDD (all P<0.001), while they were negatively correlated with LVFS and LVEF (all P<0.001). With the increase of NYHA heart function classification, plasma levels of TSG-6, Collagen Ⅰ, Collagen III, and α-SMA increased significantly (all P<0.001). The increases in plasma levels of NT-proBNP and TSG-6 was associated with poor prognosis in DCM patients with heart failure (all P<0.05). The sensitivity and specificity of plasma NT-proBNP for evaluating the prognosis of DCM heart failure were 76.2% and 68.1%, respectively. The sensitivity and specificity of plasma TSG-6 for evaluating the prognosis of DCM heart failure were 95.2% and 66.7%, respectively. The sensitivity and specificity of plasma TSG-6 combined with NT-proBNP for prognostic evaluation of DCM heart failure were 85.7% and 81.2%, respectively. The specificity of plasma TSG-6 combined with NT-proBNP for the prognosis of heart failure was better than that of NT-proBNP or TSG-6 alone (P<0.001).

CONCLUSIONS

The plasma levels TSG-6 in DCM patients with heart failure increase significantly, and the plasma levels TSG-6 could be used as a new predictor for cardiac function, myocardial fibrosis, and prognosis.

Autologous Adipose-Derived Mesenchymal Stem Cells Combined with Shockwave Therapy Synergistically Ameliorates the Osteoarthritic Pathological Factors in Knee Joint

Adipose-derived mesenchymal stem cells (ADSCs) and shockwave (SW) therapy have been shown to exert a chondroprotective effect for osteoarthritis (OA). The results of this study demonstrated that autologous ADSCs had dose-dependent and synergistic effects with SW therapy (0.25 mJ/mm2 with 800 impulses) in OA rat knee joint. Autologous, high-dose 2 × 106 ADSCs (ADSC2 group) combined with SW therapy significantly increased the bone volume, trabecular thickness, and trabecular number among in the treatment groups. ADSC2 combined with SW therapy significantly reduced the synovitis score and OARSI score in comparison with other treatments. In the analysis of inflammation-induced extracellular matrix factors of the articular cartilage in OA, the results displayed that ADSC2 combined with SW therapy had a greater than other treatments in terms of reducing tumor necrosis factor-inducible gene (TSG)-6 and proteoglycan (PRG)-4, in addition to increasing tissue inhibitor matrix metalloproteinase (TIMP)-1 and type II collagen. Furthermore, ADSC2 combined with SW therapy significantly reduced the expression of inflammation-induced bone morphogenetic protein (BMP)-2 and BMP-6. Therefore, the results demonstrated that ADSC2 combined with SW therapy had a synergistic effect to ameliorate osteoarthritic pathological factors in OA joints.

TSG-6 Is Weakly Chondroprotective in Murine OA but Does not Account for FGF2-Mediated Joint Protection

OBJECTIVE

Tumor necrosis factor α-stimulated gene 6 (TSG-6) is an anti-inflammatory protein highly expressed in osteoarthritis (OA), but its influence on the course of OA is unknown.

METHODS

Cartilage injury was assessed by murine hip avulsion or by recutting rested explants. Forty-two previously validated injury genes were quantified by real-time polymerase chain reaction in whole joints following destabilization of the medial meniscus (DMM) (6 hours and 7 days). Joint pathology was assessed at 8 and 12 weeks following DMM in 10-week-old male and female fibroblast growth factor 2 (FGF2)^-/- , TSG-6^-/- , TSG-6^tg (overexpressing), FGF2^-/- ;TSG-6^tg (8 weeks only) mice, as well as strain-matched, wild-type controls. In vivo cartilage repair was assessed 8 weeks following focal cartilage injury in TSG-6^tg and control mice. FGF2 release following cartilage injury was measured by enzyme-linked immunosorbent assay.

RESULTS

TSG-6 messenger RNA upregulation was strongly FGF2-dependent upon injury in vitro and in vivo. Fifteeen inflammatory genes were significantly increased in TSG-6^-/- joints, including IL1α, Ccl2, and Adamts5 compared with wild type. Six genes were significantly suppressed in TSG-6^-/- joints including Timp1, Inhibin βA, and podoplanin (known FGF2 target genes). FGF2 release upon cartilage injury was not influenced by levels of TSG-6. Cartilage degradation was significantly increased at 12 weeks post-DMM in male TSG-6^-/- mice, with a nonsignificant 30% reduction in disease seen in TSG-6^tg mice. No differences were observed in cartilage repair between genotypes. TSG-6 overexpression was unable to prevent accelerated OA in FGF2^-/- mice.

CONCLUSION

TSG-6 influences early gene regulation in the destabilized joint and exerts a modest late chondroprotective effect. Although strongly FGF2 dependent, TSG-6 does not explain the strong chondroprotective effect of FGF2.

Strategies to prevent hypertrophic scar formation: a review of therapeutic interventions based on molecular evidence

Once scar tissues mature, it is impossible for the surrounding tissue to regenerate normal dermal tissue. Therefore, it is essential to understand the fundamental mechanisms and establish effective strategies to inhibit aberrant scar formation. Hypertrophic scar formation is considered a result of the imbalance between extracellular matrix synthesis and degradation during wound healing. However, the underlying mechanisms of hypertrophic scar development are poorly understood. The purpose of this review was to outline the management in the early stage after wound healing to prevent hypertrophic scar formation, focusing on strategies excluding therapeutic agents of internal use. Treatment aimed at molecular targets, including cytokines, will be future options to prevent and treat hypertrophic scars. More basic studies and clinical trials, including combination therapy, are required to investigate the mechanisms and prevent hypertrophic scar formation.

Inflamm-Aging Is Associated with Lower Plasma PTX3 Concentrations and an Impaired Capacity of PBMCs to Express hTERT following LPS Stimulation

Age-related elevations in proinflammatory cytokines, known as inflamm-aging, are associated with shorter immune cell telomere lengths. Purpose. This study examined the relationship of plasma PTX3 concentrations, a biomarker of appropriate immune function, with telomere length in 15 middle-aged (40-64 years) and 15 young adults (20-31 years). In addition, PBMCs were isolated from middle-aged and young adults to examine their capacity to express a key mechanistic component of telomere length maintenance, human telomerase reverse transcriptase (hTERT), following ex vivo cellular stimulation. Methods. Plasma PTX3 and inflammatory cytokines (i.e., IL-6, IL-10, TGF-β, and TNF-α), PBMC telomere lengths, and PBMC hTERT gene expression and inflammatory protein secretion following exposure to LPS, PTX3, and PTX3+LPS were measured. Results. Aging was accompanied by the accumulation of centrally located visceral adipose tissue, without changes in body weight and BMI, and alterations in the systemic inflammatory milieu (decreased plasma PTX3 and TGF-β; increased TNF-α (p ≤ 0.050)). In addition, shorter telomere lengths in middle-aged compared to young adults (p = 0.011) were negatively associated with age, body fat percentages, and plasma TNF-α (r = -0.404, p = 0.027; r = -0.427, p = 0.019; and r = -0.323, p = 0.041, respectively). Finally, the capacity of PBMCs to increase hTERT gene expression following ex vivo stimulation was impaired in middle-aged compared to young adults (p = 0.033) and negatively associated with telomere lengths (r = 0.353, p = 0.028). Conclusions. Proinflammation and the impaired hTERT gene expression capacity of PBMCs may contribute to age-related telomere attrition and disease.

High TNFAIP6 level is associated with poor prognosis of urothelial carcinomas

PURPOSE

Inflammatory responses affect each stage of carcinogenesis, from initiation, through invasion, to metastasis. Studies have shown that chronic inflammation induced by environmental and occupational exposures increase the risk of developing urothelial carcinoma (UC). Using a published UC transcriptome (GSE32894), we identified that among genes associated with inflammatory response (GO:0006954), TNFAIP6 was significantly upregulated during UC progression. Therefore, we investigated the association of TNFAIP6 with disease features, metastasis and survival in our well-characterized cohort of UC.

METHODS

We determined TNFAIP6 expression in 340 upper urinary tract UCs (UTUC) and 295 urinary bladder UCs (UBUC) using immunohistochemistry and evaluated the results using H-score. TNFAIP6 expression correlated with clinicopathological features, disease-specific survival, and metastasis-free survival. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards model.

RESULTS

High TNFAIP6 expression was significantly associated with advanced pathological stage, lymph node metastasis, perineural invasion, vascular invasion, and high mitotic activity. Multivariate analysis identified high TNFAIP6 expression as an independent predictor of disease-specific survival (hazard ratio in UTUC: 2.891, P = 0.003; in UBUC: 2.175, P = 0.017) and metastasis-free survival (hazard ratio in UTUC: 3.803, P < 0.001; in UBUC: 3.845, P < 0.001).

CONCLUSION

High TNFAIP6 expression is associated with aggressive clinicopathological features and poor prognosis in UCs, suggesting it may serve as a novel prognosticator and treatment target. TNFAIP6 immunostaining may be used with current pathological examinations for better risk stratification for UCs.

The Long Pentraxin PTX3 Is an Endogenous Inhibitor of Hyperoxaluria-Related Nephrocalcinosis and Chronic Kidney Disease

The long pentraxin 3 (PTX3) exerts a variety of regulatory functions in acute and chronic tissue inflammation. In particular, PTX3 acts as an opsonin for a variety of pathogens and endogenous particles. We hypothesized that PTX3 would exhibit opsonin-like functions toward calcium oxalate crystals, too, and inhibit crystal growth. This process is fundamental in kidney stone disease as well as in hyperoxaluria-related nephrocalcinosis, the paradigmatic cause of chronic kidney disease (CKD) in children with primary hyperoxaluria type I due to genetic defects in oxalate metabolism. Direct effects of PTX3 on calcium oxalate crystals were investigated in chemico by adding recombinant PTX3 to supersaturated calcium and oxalate solutions. PTX3, but not isomolar concentrations of albumin, dose-dependently inhibited crystal growth. In vivo, the PTX3 protein was undetectable in tubular epithelial cells and urine of wild-type mice under physiological conditions. However, its levels increased within 3 weeks of feeding an oxalate-rich diet, an exposure inducing hyperoxaluria-related nephrocalcinosis and CKD in selected mouse strains (male and female C57BL/6N and male Balb/c mice) but not in others (male and female 129SV and CD-1, male and female Balb/c mice). Genetic ablation of ptx3 in nephrocalcinosis un-susceptible B6;129 mice was sufficient to raise the oxalate nephropathy phenotype observed in susceptible strains. We conclude that PTX3 is an endogenous inhibitor of calcium oxalate crystal growth. This mechanism limits hyperoxaluria-related nephrocalcinosis, e.g., in primary or secondary hyperoxaluria, and potentially also in the more prevalent kidney stone disease.

Emerging Roles of Tumor Necrosis Factor-Stimulated Gene-6 in the Pathophysiology and Treatment of Atherosclerosis

Tumor necrosis factor-stimulated gene-6 (TSG-6) is a 35-kDa glycoprotein that has been shown to exert anti-inflammatory effects in experimental models of arthritis, acute myocardial infarction, and acute cerebral infarction. Several lines of evidence have shed light on the pathophysiological roles of TSG-6 in atherosclerosis. TSG-6 suppresses inflammatory responses of endothelial cells, neutrophils, and macrophages as well as macrophage foam cell formation and vascular smooth muscle cell (VSMC) migration and proliferation. Exogenous TSG-6 infusion and endogenous TSG-6 attenuation with a neutralizing antibody for four weeks retards and accelerates, respectively, the development of aortic atherosclerotic lesions in ApoE-deficient mice. TSG-6 also decreases the macrophage/VSMC ratio (a marker of plaque instability) and promotes collagen fibers in atheromatous plaques. In patients with coronary artery disease (CAD), plasma TSG-6 levels are increased and TSG-6 is abundantly expressed in the fibrous cap within coronary atheromatous plaques, indicating that TSG-6 increases to counteract the progression of atherosclerosis and stabilize the plaque. These findings indicate that endogenous TSG-6 enhancement and exogenous TSG-6 replacement treatments are expected to emerge as new lines of therapy against atherosclerosis and related CAD. Therefore, this review provides support for the clinical utility of TSG-6 in the diagnosis and treatment of atherosclerotic cardiovascular diseases.

TSG-6 - a double-edged sword for osteoarthritis (OA)

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 < 0.0002) with inflammatory mediators including TIMP-1, A2M, MMP3, VEGF, VCAM-1, ICAM-1 and IL-6. Although TSG-6 protein and mRNA were highly expressed in damaged articular and meniscal cartilage and cytokine-treated chondrocytes, there was little or no cartilage expression of components of the IαI complex (containing HC1). By IHC, TSG-6 was present throughout lesioned cartilage but HC1 only at lesioned surfaces. TSG-6 impaired HA-aggrecan assembly, but TSG-6 mediated HA-HC formation reduced this negative effect.

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.

TSG-6 is highly expressed in human abdominal aortic aneurysms

BACKGROUND

The formation of abdominal aortic aneurysms (AAA) is characterized by a dominance of proinflammatory forces that result in smooth muscle cell apoptosis, extracellular matrix degradation, and progressive diameter expansion. Additional defects in the antiinflammatory response may also play a role but have yet to be fully characterized. TSG-6 (TNF-stimulated gene-6) is a potent antiinflammatory protein involved in extracellular matrix stabilization and cell migration active in many pathological conditions. Here, we describe its role in AAA formation.

METHODS

Blood and/or aortic tissue samples were collected from organ donors, subjects undergoing elective AAA screening, and open surgical AAA repair. Aortic specimens collected were preserved for IHC or immediately assayed after tissue homogenization. Protein concentrations in tissue and plasma were assayed by ELISA. All immune cell populations were assayed using FACS. In vitro, macrophage polarization from monocytes was performed with young, healthy donor PBMCs.

RESULTS

TSG-6 was found to be abnormally elevated in both the plasma and aortic wall of patients with AAA compared with healthy and risk-factor matched non-AAA donors. We observed the highest tissue concentration of TSG-6 in the less-diseased proximal and distal shoulders compared with the central aspect of the aneurysm. IHC localized most TSG-6 to the tunica media with minor expression in the tunica adventitia of the aortic wall. Higher concentrations of both M1 and M2 macrophages where also observed, however M1/M2 ratios were unchanged from healthy controls. We observed no difference in M1/M2 ratios in the peripheral blood of risk-factor matched non-AAA and AAA patients. Interesting, TSG-6 inhibited the polarization of the antiinflammatory M2 phenotype in vitro.

CONCLUSIONS

AAA formation results from an imbalance of inflammatory forces causing aortic wall infiltration of mononuclear cells leading to the vessel breakdown. In the AAA condition, we report an elevation of TSG-6 expression in both the aortic wall and the peripheral circulation.

HCV-induced regulatory alterations of IL-1β, IL-6, TNF-α, and IFN-ϒ operative, leading liver en-route to non-alcoholic steatohepatitis

Over the course of time, Hepatitis C has become a universal health menace. Its deleterious effects on human liver encompass a lot of physiological, genetic as well as epigenetic alterations. Fatty liver (Hepatic steatosis) is an inflammation having multifactorial ancestries; one of them is HCV (steatohepatitis). HCV boosts several cellular pathways involving up-regulation of a number of cytokines. Current study reviews the regulation of some selective key cytokines during HCV infection, to help generate an improved understanding of their role. These cytokines, IL-1β, IL-6, TNF-α, and IFN-ϒ, are inflammatory markers of the body. These particular markers along with others help hepatocytes against viral infestation. However, recently, their association has been found in degradation of liver on the trail heading to non-alcoholic steatohepatitis (NASH). Consequently, the disturbance in their equilibrium has been repeatedly reported during HCV infection. Quite a number of findings are affirming their up-regulation. Although these cell markers are stimulated by hepatocytes as their standard protection mechanism, but modern studies have testified the paradoxical nature of this defense line. Nevertheless, direct molecular or epigenetic research is needed to question the actual molecular progressions and directions commanding liver to steatosis, cirrhosis, or eventually HCC (Hepatocellular Carcinoma).

Extrinsic and Intrinsic Mechanisms by Which Mesenchymal Stem Cells Suppress the Immune System

Mesenchymal stem cells (MSCs) are a group of fibroblast-like multipotent mesenchymal stromal cells that have the ability to differentiate into osteoblasts, adipocytes, and chondrocytes. Recent studies have demonstrated that MSCs possess a unique ability to exert suppressive and regulatory effects on both adaptive and innate immunity in an autologous and allogeneic manner. A vital step in stem cell transplantation is overcoming the potential graft-versus-host disease, which is a limiting factor to transplantation success. Given that MSCs attain powerful differentiation capabilities and also present immunosuppressive properties, which enable them to survive host immune rejection, MSCs are of great interest. Due to their ability to differentiate into different cell types and to suppress and modulate the immune system, MSCs are being developed for treating a plethora of diseases, including immune disorders. Moreover, in recent years, MSCs have been genetically engineered to treat and sometimes even cure some diseases, and the use of MSCs for cell therapy presents new perspectives for overcoming tissue rejection. In this review, we discuss the potential extrinsic and intrinsic mechanisms that underlie MSCs' unique ability to modulate inflammation, and both innate and adaptive immunity.

The oncolytic virus dl922-947 reduces IL-8/CXCL8 and MCP-1/CCL2 expression and impairs angiogenesis and macrophage infiltration in anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human solid tumor and current treatments are ineffective in increasing patients' survival. Thus, the development of new therapeutic approaches for ATC is needed. We have previously shown that the oncolytic adenovirus dl922-947 induces ATC cell death in vitro and tumor regression in vivo. However, the impact of dl922-947 on the pro-tumorigenic ATC microenvironment is still unknown. Since viruses are able to regulate cytokine and chemokine production from infected cells, we sought to investigate whether dl922-947 virotherapy has such effect on ATC cells, thereby modulating ATC microenvironment. dl922-947 decreased IL-8/CXCL8 and MCP-1/CCL2 production by the ATC cell lines 8505-c and BHT101-5. These results correlated with dl922-947-mediated reduction of NF-κB p65 binding to IL8 promoter in 8505-c and BHT101-5 cells and CCL2 promoter in 8505-c cells. IL-8 stimulates cancer cell proliferation, survival and invasion, and also angiogenesis. dl922-947-mediated reduction of IL-8 impaired ATC cell motility in vitro and ATC-induced angiogenesis in vitro and in vivo. We also show that dl922-947-mediated reduction of the monocyte-attracting chemokine CCL2 decreased monocyte chemotaxis in vitro and tumor macrophage density in vivo. Interestingly, dl922-947 treatment induced the switch of tumor macrophages toward a pro-inflammatory M1 phenotype, likely by increasing the expression of the pro-inflammatory cytokine interferon-γ. Altogether, we demonstrate that dl922-947 treatment re-shape the pro-tumorigenic ATC microenvironment by modulating cancer-cell intrinsic factors and the immune response. An in-depth knowledge of dl922-947-mediated effects on ATC microenvironment may help to refine ATC virotherapy in the context of cancer immunotherapy.

Anti-inflammatory cytokine TSG-6 inhibits hypertrophic scar formation in a rabbit ear model

Hypertrophic scars are characterized by excessive fibrosis and extracellular matrix (ECM) deposition and can be functionally and cosmetically problematic; however, there are few satisfactory treatments for controlling hypertrophic scars. The inflammatory cells and cytokines involved in excessive inflammation during wound healing facilitate fibroblast proliferation and collagen deposition, leading to pathologic scar formation. TSG-6 exhibits anti-inflammatory activity. This study examined the effect of recombinant TSG-6 on inflammation in hypertrophic scars using a rabbit ear model. Six 7-mm, full-thickness, circular wounds were made on the ears of 12 rabbits. TSG-6 and PBS were intradermally injected into the right and left ear wounds, respectively. The methods of TEM and TUNEL were used to detect fibroblast apoptosis. The expressions of inflammatory factors: IL-1β, IL-6 and TNF-α, were detected by immunohistochemistry and real time polymerase chain reaction. Collagen I and III expression detected by immunohistochemistry and Masson׳s trichrome staining and SEI (scar elevation index) was used to evaluate the extent of scarring. TSG-6 injection mitigated the formation of a hypertrophic scar in the rabbit ear. TSG-6-treated wounds exhibited decreased inflammation compared with the control group, as evidenced by the lower levels of IL-1β, IL-6, TNF-α and MPO. The SEI and the synthesis of collagens I and III were significantly decreased in the TSG-6-treated scars compared with control scars. The apoptosis rate was higher in the TSG-6-treated scars. TSG-6 exhibited anti-inflammatory effects during the wound healing process and cicatrization and significantly diminished hypertrophic scar formation in a rabbit ear model.

Concise Review: Mesenchymal Stem Cells Ameliorate Tissue Injury via Secretion of Tumor Necrosis Factor-α Stimulated Protein/Gene 6

Numerous reports have described therapeutic benefits in various disease models after administration of the adult stem/progenitor cells from bone marrow or other tissues referred to as mesenchymal stem cells/multipotent mesenchymal stromal cells (MSCs). They all showed that one of the important effects of MSCs is to act against excessive inflammatory responses and repair the damaged tissues. The therapeutic benefits of MSCs were initially interpreted by their migration, engraftment, and differentiation into target tissues. However, remarkable anatomical structural repairs and functional improvements were increasingly observed with a small number of or even no MSCs in the injured tissues. This suggests that most beneficial effects are largely due to paracrine secretions or cell-to-cell contacts that have multiple effects involving modulation of inflammatory and immune responses. Currently, the therapeutic benefits of MSCs are in part explained by the cells being activated by signals from injured tissues to express an anti-inflammatory protein, tumor-necrosis-factor-α-induced protein 6. This important mechanism of action has attracted increasing attention, and therefore we conducted this review to summarize the latest research.

Selective expression of Narp in primary nociceptive neurons: role in microglia/macrophage activation following nerve injury

Neuronal activity regulated pentraxin (Narp) is a secreted protein implicated in regulating synaptic plasticity via its association with the extracellular surface of AMPA receptors. We found robust Narp immunostaining in dorsal root ganglia (DRG) that is largely restricted to small diameter neurons, and in the superficial layers of the dorsal horn of the spinal cord. In double staining studies of DRG, we found that Narp is expressed in both IB4- and CGRP-positive neurons, markers of distinct populations of nociceptive neurons. Although a panel of standard pain behavioral assays were unaffected by Narp deletion, we found that Narp knockout mice displayed an exaggerated microglia/macrophage response in the dorsal horn of the spinal cord to sciatic nerve transection 3days after surgery compared with wild type mice. As other members of the pentraxin family have been implicated in regulating innate immunity, these findings suggest that Narp, and perhaps other neuronal pentraxins, also regulate inflammation in the nervous system.

Design, synthesis and evaluation of novel diaryl pyrrolopyrimidine and pyrrolothiazine derivatives as inhibitors of tumor necrosis factor stimulated gene-14 (TSG-14) production

A novel series of pyrrolothiazines 2-4 and pyrrolopyrimidines 5-7 have been synthesized. The structures of these compounds were established by spectroscopic and element microanalytical data. The newly synthesized compounds were evaluated as inhibitors of TSG-14. The most effective results were obtained by the S-sec-butyl derivatives 6e (80%) and the N-ethyl derivatives 4e (70%).

TSG-6 activity as a novel biomarker of progression in knee osteoarthritis

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.

Expression microarray analysis identifies novel epithelial-derived protein markers in eosinophilic esophagitis

Gene expression studies in eosinophilic esophagitis support an immune-mediated etiology associated with differential regulation of inflammatory and epithelial-derived genes. We aimed to further characterize epithelial gene expression alterations in eosinophilic esophagitis and to explore the use of immunohistochemistry to identify these alterations. Esophageal biopsies from pediatric patients with eosinophilic esophagitis before and after therapy with topical steroids (N=7) were screened by gene expression microarray and results were validated by RT-PCR. A larger group of eosinophilic esophagitis patients (N=42) was then used to evaluate protein expression by immunohistochemistry compared with reflux patients (N=15) and normal controls (N=17). Microarray and RT-PCR studies identified overexpression of ALOX15 and tumor necrosis factor alpha-induced factor 6 (TNFAIP6) and underexpression of filaggrin (FLG), SLURP1 and cysteine-rich secretory protein 3 (CRISP3) in eosinophilic esophagitis. Immunohistochemistry for ALOX15 was positive in 95% of eosinophilic esophagitis and negative in all controls, all eosinophilic esophagitis after therapy and all reflux biopsies (P<0.001). TNFAIP6 was positive in 88% of eosinophilic esophagitis samples versus 47% of controls, 29% of eosinophilic esophagitis after therapy and 40% of reflux samples (P=0.002). Overexpression of both ALOX15 and TNFAIP6 directly correlated with the degree of eosinophilic infiltration. FLG was positive in 88% of controls and 100% of reflux biopsies, but negative in all eosinophilic esophagitis samples, and its expression was regained in 86% of eosinophilic esophagitis after therapy patients (P<0.001). SLURP1 expression was positive in all controls and reflux samples, but only positive in 5% of eosinophilic esophagitis and was re-expressed to 100% positivity in eosinophilic esophagitis after therapy patients (P<0.001). The majority of controls (89%) and reflux biopsies (100%) were positive for CRISP3 while eosinophilic esophagitis before therapy were positive in 14% of samples (P<0.001) with partial recovery after treatment (43%, P=0.105). This study identified five epithelial-derived markers differentially expressed in eosinophilic esophagitis easily detectable by immunohistochemistry with potential diagnostic utility.

Atypical hemolytic uremic syndrome-associated variants and autoantibodies impair binding of factor h and factor h-related protein 1 to pentraxin 3

Atypical hemolytic uremic syndrome (aHUS) is a renal disease associated with complement alternative pathway dysregulation and is characterized by endothelial injury. Pentraxin 3 (PTX3) is a soluble pattern recognition molecule expressed by endothelial cells and upregulated under inflammatory conditions. PTX3 activates complement, but it also binds the complement inhibitor factor H. In this study, we show that native factor H, factor H-like protein 1, and factor H-related protein 1 (CFHR1) bind to PTX3 and that PTX3-bound factor H and factor H-like protein 1 maintain their complement regulatory activities. PTX3, when bound to extracellular matrix, recruited functionally active factor H. Residues within short consensus repeat 20 of factor H that are relevant for PTX3 binding were identified using a peptide array. aHUS-associated factor H mutations within this binding site caused a reduced factor H binding to PTX3. Similarly, seven of nine analyzed anti-factor H autoantibodies isolated from aHUS patients inhibited the interaction between factor H and PTX3, and five autoantibodies also inhibited PTX3 binding to CFHR1. Moreover, the aHUS-associated CFHR1*B variant showed reduced binding to PTX3 in comparison with CFHR1*A. Thus, the interactions of PTX3 with complement regulators are impaired by certain mutations and autoantibodies affecting factor H and CFHR1, which could result in an enhanced local complement-mediated inflammation, endothelial cell activation, and damage in aHUS.

Human pentraxin 3 binds to the complement regulator c4b-binding protein

The long pentraxin 3 (PTX3) is a soluble recognition molecule with multiple functions including innate immune defense against certain microbes and the clearance of apoptotic cells. PTX3 interacts with recognition molecules of the classical and lectin complement pathways and thus initiates complement activation. In addition, binding of PTX3 to the alternative complement pathway regulator factor H was shown. Here, we show that PTX3 binds to the classical and lectin pathway regulator C4b-binding protein (C4BP). A PTX3-binding site was identified within short consensus repeats 1–3 of the C4BP α-chain. PTX3 did not interfere with the cofactor activity of C4BP in the fluid phase and C4BP maintained its complement regulatory activity when bound to PTX3 on surfaces. While C4BP and factor H did not compete for PTX3 binding, the interaction of C4BP with PTX3 was inhibited by C1q and by L-ficolin. PTX3 bound to human fibroblast- and endothelial cell-derived extracellular matrices and recruited functionally active C4BP to these surfaces. Whereas PTX3 enhanced the activation of the classical/lectin pathway and caused enhanced C3 deposition on extracellular matrix, deposition of terminal pathway components and the generation of the inflammatory mediator C5a were not increased. Furthermore, PTX3 enhanced the binding of C4BP to late apoptotic cells, which resulted in an increased rate of inactivation of cell surface bound C4b and a reduction in the deposition of C5b-9. Thus, in addition to complement activators, PTX3 interacts with complement inhibitors including C4BP. This balanced interaction on extracellular matrix and on apoptotic cells may prevent excessive local complement activation that would otherwise lead to inflammation and host tissue damage.

Characterization of hyaluronan and TSG-6 in skin scarring: differential distribution in keloid scars, normal scars and unscarred skin

Background Hyaluronan (HA) is a major component of the extracellular matrix (ECM) with increased synthesis during tissue repair. Tumour necrosis factor-stimulated gene-6 (TSG-6) is known to catalyze the covalent transfer of heavy chains (HC1 and HC2) from inter-α-inhibitor (IαI) onto HA, and resultant HC•HA complexes have been implicated in physiological and pathological processes related to remodelling and inflammation.

Objective The aims of this study were to determine the expression of HA, TSG-6 and the IαI polypeptides in unscarred skin, normal scars and keloid scars.

Methods Formalin-fixed paraffin-embedded sections of unscarred skin, normal scars and keloid scars were prepared from patient samples collected during scar revision surgery. Haematoxylin and eosin, as well as immunofluorescent staining for HA, TSG-6 and the three polypeptide chains of IαI (i.e. HC1, HC2 and bikunin) were performed.

Results All skin types stained positive for TSG-6, HC1, HC2 and bikunin, associated with keratinocytes, fibroblasts and skin appendages all in close proximity to HA. Keloid lesions showed altered HA organization patterns compared with unscarred skin and normal scars. TSG-6 staining was significantly more intense in the epidermis compared with the dermis of all sample types. There was a significant reduction in TSG-6 levels within keloid lesions compared with the dermis of unscarred skin (P = 0.017).

Conclusion TSG-6 is expressed in unscarred skin, where its close association with HA and IαI could give rise to TSG-6-mediated HC•HA formation within this tissue. A reduction in the beneficial effects of TSG-6, caused by diminished protein levels in keloid lesions, could contribute to this abnormal scarring process.

Plasma pentraxin3 and arterial stiffness in men with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) induces inflammation and vascular damage that might contribute to an increased risk of cardiovascular disease (CVD). However, the mechanisms linking OSA and CVD are not fully understood. Pentraxin3 may play a significant role in vascular inflammation and damage. Currently, there is lack of data on pentraxin3 and its role in vascular damage associated with OSA.

METHODS

We enrolled 50 males with OSA and 25 controls matched for age and body mass index (BMI). Patients with OSA were further divided into mild and moderate to severe groups. We measured plasma pentraxin3 and evaluated vascular damage using an arterial stiffness parameter--the cardio-ankle vascular index (CAVI)--in all subjects. In the moderate to severe OSA group, pentraxin3 and CAVI were repeatedly measured following continuous positive airway pressure (CPAP) therapy for 1 month.

RESULTS

Pentraxin3 levels in the moderate-to-severe OSA group were significantly higher than those in the mild OSA and control groups, with median levels (25th-75th percentile) of 2.36 (1.79-2.78), 1.63 (1.15-2.05), and 1.53 (1.14-2.04) ng/ml, respectively (P < 0.01). Pentraxin3 level was independently correlated with CAVI (coefficient, 0.34 P < 0.01). In the moderate-to-severe OSA group, pentraxin3 and CAVI levels were significantly reduced (P < 0.01 and P = 0.04, respectively) after 1 month of CPAP therapy.

CONCLUSIONS

Plasma pentraxin3 and arterial stiffness levels in the moderate-to-severe OSA group were greater than the corresponding levels in patients without OSA. However, pentraxin3 level can be managed by CPAP therapy for OSA.

The long pentraxin PTX3 is crucial for tissue inflammation after intestinal ischemia and reperfusion in mice

The pentraxin superfamily is a group of evolutionarily conserved proteins that play important roles in the immune system. The long pentraxin PTX3 protein was originally described as able to be induced by pro-inflammatory stimuli in a variety of cell types. In this study, we evaluated the phenotype of Ptx3(-/-) mice subjected to ischemia followed by reperfusion of the superior mesenteric artery. In reperfused wild-type mice, there was significant local and remote injury as demonstrated by increases in vascular permeability, neutrophil influx, nuclear factor-kappaB activation, and production of CXCL1 and tumor necrosis factor-alpha. PTX3 levels were elevated in both serum and intestine after reperfusion. In Ptx3(-/-) mice, local and remote tissue injury was inhibited, and there were decreased nuclear factor-kappaB translocation and cytokine production. Intestinal architecture was preserved, and there were decreased neutrophil influx and significant prevention of lethality in Ptx3(-/-) mice as well. PTX3 given intravenously before reperfusion reversed the protection observed in Ptx3(-/-) mice in a dose-dependent manner, and PTX3 administration significantly worsened tissue injury and lethality in wild-type mice. In conclusion, our studies demonstrate a major role for PTX3 in determining acute reperfusion-associated inflammation, tissue injury, and lethality and suggest the soluble form of this molecule is active in this system. Therapeutic blockade of PTX3 action may be useful in the control of the injuries associated with severe ischemia and reperfusion syndromes.

The long pentraxin 3 and its role in autoimmunity

OBJECTIVES

To review the physiological and physiopathological roles of pentraxin 3 (PTX3), focusing on autoimmunity and vascular pathology.

METHODS

A systematic literature review using the keywords "pentraxin 3," "innate immunity," "apoptosis," "autoimmunity," and "endothelial dysfunction" from 1990 to 2007 was performed. All relevant articles and pertinent secondary references in English were reviewed.

RESULTS

PTX3 has a large number of multiple functions in different contexts. PTX3 plays an important role in innate immunity, inflammation, vascular integrity, fertility, pregnancy, and also in the central nervous system. In innate immunity, its normal function is to increase the immune response to selected pathogens while also exerting control over potential autoimmune reactions. It maintains a tightly homeostatic equilibrium in the local immune microenvironment by avoiding an exaggerated immune response and controlling peripheral tolerance to self-antigens. In contrast, in some autoimmune diseases, PTX3 appears to be involved in the development of autoimmune phenomena. A possible explanation for these apparent paradoxical functions may be related to the highly polymorphic PTX3 gene.

CONCLUSION

PTX3 is physiologically a protective molecule. However, in several autoimmune diseases PTX3 appears to facilitate the development of autoimmunity. The PTX3 gene could influence the development of autoimmune reactions and vascular involvement in human pathology.

Major differences in gene expression in human coronary smooth muscle cells after nebivolol or metoprolol treatment

OBJECTIVE

Vascular smooth muscle cells play a pivotal role in all stages of atherogenesis. Targeting their inflammatory and proliferative qualities might therefore inhibit the progression of atherosclerosis. This study aimed to characterize and compare the effects of the beta-receptor antagonists nebivolol and metoprolol on gene expression in human coronary artery smooth muscle cells (hcaSMC).

METHODS AND RESULTS

hcaSMC were incubated with nebivolol or metoprolol (10(-5) mol/l) for 72 h. The downregulated genes are involved in inflammatory processes, oxidative stress and smooth muscle cell proliferation: i.e. downregulated were by nebivolol: interleukin-1alpha, cyclooxygenase-2, tumor-necrosis-factor (TNF)-alpha-induced protein 6, PDGF-A, growth-related oncogenes 2 and 3. Metoprolol increased the expression of interleukin-1alpha, cyclooxygenase-1, TNF-alpha-induced protein 3, heme oxygenase 1 and granulocyte/macrophage-colony-stimulating factor. In addition downregulated was monocyte chemoattractant protein 1 (MCP-1) mRNA by nebivolol. Nebivolol (10(-5) mol/l) reduced the amount of basal NF-kappaB after 48 and 52 h but not metoprolol. In the culture supernatants, MCP-1 concentrations were reduced by nebivolol.

CONCLUSIONS

Nebivolol induced changes in the expression of inflammatory mediators in hcaSMC. These results add to data that suggest specific anti-inflammatory qualities of a beta-blocker of the third generation in comparison to metoprolol.

Upregulation of pentraxin-3 in human endothelial cells after lysophosphatidic acid exposure

OBJECTIVE

The earliest event in atherogenesis appears to be endothelium dysfunction. Lysophosphatidic acid (LPA), one of the major bioactive lipid components of oxidized low-density lipoproteins (oxLDL), can cause the activation of endothelial cells (ECs), which start to secrete multiple proinflammatory polypeptides/proteins. The purpose of this study was to better document the proatherogenic properties of LPA using a subproteomic approach focused on the secretome of LPA-treated ECs.

METHODS AND RESULTS

The secretome of LPA-treated ECs was analyzed using the 2D-DIGE approach. Among the 20 spots displaying significant variations of abundance compared with the control cells, we identified pentraxin-3 by mass spectrometry. Pentraxin-3 upregulation was confirmed at the mRNA and protein level, both on immortalized and primary ECs. LPA- but also oxLDL-induced pentraxin-3 upregulation was reduced in the presence of an antagonist of the LPA-receptors and largely dependent on NFkappaB activation. Finally, we demonstrated, for the first time, the chemotactic activity of pentraxin-3 on human THP-1 monocytes by using a chemotaxis assay.

CONCLUSIONS

Our findings favor the proatherogenic role of LPA, a bioactive lipid produced by activated platelets and present in oxLDL, because it enhances pentraxin-3 secretion that could contribute to the accumulation of monocytes in the atherosclerotic lesion.

Long pentraxin 3 in pulmonary infection and acute lung injury

Long pentraxin 3 (PTX3) is a newly discovered acute phase protein produced at the sites of infection and inflammation by tissue cells, macrophages, monocytes, and dendritic cells. PTX3 plays an important role in preventing infection of certain fungi, bacteria, and viruses in the lung. Recombinant PTX3 has been proposed as a potential antifungal molecule for therapy. However, under certain experimental conditions, such as intestinal ischemia-reperfusion, high volume mechanical ventilation, or severe bacterial infection, increased expression of PTX3 is associated with more severe lung injury. Therefore, it is necessary to further explore the sources of PTX3 in the lung and the regulatory mechanisms of its expression. It is also essential to further determine how PTX3 binds to pathogens, complement, and apoptotic cells, and to determine whether PTX3 has a specific receptor in targeted cells. These studies will provide insight into the pathological processes of pulmonary infection and acute lung injury and provide potential novel therapeutic strategies to control pulmonary infections without severe lung injury.

Mechanism of IFN-beta-mediated inhibition of IL-8 gene expression in astroglioma cells

IL-8 is a chemokine that recruits migrating neutrophils and leukocytes to areas of inflammation. In noninflamed tissue, IL-8 expression is low but can be rapidly induced by proinflammatory cytokines. Typically, inflammation and transient IL-8 expression are beneficial. However, some diseases are characterized by excessive inflammation and high levels of IL-8. Previous studies have shown that IFN-beta can inhibit the expression of IL-8, although the mechanism is unknown. Using chromatin immunoprecipitation assays, we define the IL-8 transcriptional program in the absence or presence of inducing stimuli and/or inhibition by IFN-beta. In the absence of stimuli, the IL-8 promoter is acetylated but negatively regulated by corepressor proteins. Upon PMA stimulation, the levels of these corepressors are reduced and the promoter is rapidly bound and activated by transcription factors, including NF-kappaB p65, C/EBPbeta, and c-Fos. In addition, RNA polymerase II is recruited to the IL-8 promoter to initiate transcription. However, in the presence of both PMA and IFN-beta, there are diminished levels of histone acetylation, reduced levels of transcription factors such as NF-kappaB p65 and RNA polymerase II, and an increased presence of corepressor proteins such as histone deacetylases 1 and 3 and silencing mediator of retinoic acid and thyroid hormone receptors. IFN-gamma-inducible protein-10 and MCP-1 genes, also regulated by NF-kappaB, are unaffected by IFN-beta, and IFN-beta does not prevent the activation, nuclear migration, or binding of NF-kappaB p65 to the kappaB element of the IFN-gamma-inducible protein-10 promoter. As such, these data show that the inhibitory effects of IFN-beta are specific to the IL-8 promoter.

TSG-6: a pluripotent inflammatory mediator?

TSG-6 is a multifunctional protein that is up-regulated in many pathological and physiological contexts, where it plays important roles in inflammation and tissue remodelling. For example, it is a potent inhibitor of neutrophil migration and can modulate the protease network through inhibition of plasmin. TSG-6 binds a wide range of GAGs (glycosaminoglycans) [i.e. HA (hyaluronan), chondroitin 4-sulphate, dermatan sulphate, heparin and heparan sulphate] as well as a variety of protein ligands, where these interactions can influence the activities of TSG-6. For example, through its association with HA, TSG-6 can mediate HA cross-linking via several different mechanisms, some of which promote leucocyte adhesion. Binding to heparin, however, enhances the ability of TSG-6 to potentiate the anti-plasmin activity of inter-alpha-inhibitor, which binds non-covalently to TSG-6 via its bikunin chain. Furthermore, although HA and heparin interact with distinct sites on the Link module, the binding of heparin can inhibit subsequent interaction with HA. In addition, the interactions of TSG-6 with HA, heparin and at least some of its protein ligands are sensitive to pH. Therefore it seems that in different tissue micro-environments (characterized, for example, by pH and GAG content), TSG-6 could be partitioned into functional pools with distinct activities.

Dual function of the long pentraxin PTX3 in resistance against pulmonary infection with Klebsiella pneumoniae in transgenic mice

The long pentraxin PTX3 is expressed during acute inflammation and appears to control nitric oxide (NO) and tumor necrosis factor (TNF)-alpha production. In the present study, the physiological function of PTX3 was investigated in a model of pulmonary infection caused by the Gram-negative bacterium Klebsiella pneumoniae. Transgenic mice expressing multiple copies of PTX3 under the control of its own promoter were used to assess lethality rates, bacterial counts and inflammatory indices following pulmonary infection of mice. Expression of PTX3 is enhanced during pulmonary infection in wild-type mice. In transgenic mice given a high inoculum, overt PTX3 expression was associated with faster lethality. Faster lethality correlated with enhanced nitrate in plasma, an inability of neutrophils to migrate to lung tissue and greater dissemination of bacteria to blood at 20h after infection. In contrast, transgenic PTX3 expression conferred protection to mice given lower pulmonary inocula. In the latter experiments, there was enhanced TNF-alpha production, greater neutrophil influx and phagocytosis of bacteria by migrated neutrophils. By controlling the production of TNF-alpha and NO, and depending on the intensity of the inflammatory response induced by a given inoculum, the expression of PTX3 may favor or disfavor the influx of neutrophils and the ability of the murine host to deal with pulmonary infection with K. pneumoniae. These experiments highlight the delicate balance that exists among the various mediators that control the inflammatory response and suggest that PTX3 is an essential part of the ability of a host to deal with bacterial infection.

An assay for bacterial and eukaryotic chondroitinases using a chondroitin sulfate-binding protein

A simple, rapid, and reproducible microtiter-based chondroitinase (CSase) assay is reported here, based on the competition of chondroitin sulfate (CS) with immobilized hyaluronan (HA) for the binding of TSG-6 protein, the product of TNF-inducible gene 6. Although the catabolic reaction of bacterial and other prokaryotic CSase enzymes, often referred to as the chondroitin lyases, can be followed by tracking the generation of unsaturated bonds by the spectrophotometrical determination of the absorbance at 232 nm, no rapid, sensitive, and simple assay has been devised to date for measuring the activity of the vertebrate enzymes that cleave their substrate exclusively by hydrolysis. We provide data demonstrating that the CSase assay described here is suitable for the determination of the activities of both classes of enzymes. For the bacterial enzyme CSase ABC, both the determination of the absorbance at 232 nm and the assay based on TSG-6 binding are suitable using the same range of enzyme activities. However, for testicular hyaluronidase, considerably higher enzyme activities were needed to cleave CS than to cleave HA. Using the HA-binding domain of aggrecan for a comparison, we determined that the interaction between TSG-6 and chondroitin sulfate is uniquely suited for this CSase assay.

Synergy in cytokine and chemokine networks amplifies the inflammatory response

The inflammatory response is a highly co-ordinated process involving multiple factors acting in a complex network as stimulators or inhibitors. Upon infection, the sequential release of exogenous agents (e.g. bacterial and viral products) and induction of endogenous mediators (e.g. cytokines and chemokines) contribute to the recruitment of circulating leukocytes to the inflamed tissue. Microbial products trigger multiple cell types to release cytokines, which in turn are potent inducers of chemokines. Primary cytokines act as endogenous activators of the immune response, whereas inducible chemokines act as secondary mediators to attract leukocytes. Interaction between exogenous and endogenous mediators thus enhances the inflammatory response. In this review, the synergistic interaction between cytokines to induce chemokine production and the molecular mechanisms of the cooperation amongst co-induced chemokines to further increase leukocyte recruitment to the site of inflammation are discussed.

Expression of tumor necrosis factor-alpha stimulated gene-6 mRNA in cultured human uterine cervical fibroblasts

BACKGROUND

Uterine cervical ripening process is an active biochemical process similar in part to inflammatory reaction. In this process, hyaluronan plays important roles including facilitation of tissue hydration, release of matrix metalloproteinases and migration of inflammatory cells. The activities of hyaluronan are mediated by the hyaluronan binding proteins, hyaladherins. In the present study, we investigated the mRNA expression of tumor necrosis factor-alpha stimulated gene-6 (TSG-6), a member of the hyaladherin family, in cultured human uterine fibroblasts and uterine cervical tissues.

METHODS

We developed one-step RT-PCR method for the quantification of TSG-6 mRNA and quantified the expression of TSG-6 mRNA in cultured human uterine fibroblasts, treated with or not proinflammatory cytokines, and TSG-6 mRNA in uterine cervical tissues.

RESULTS

We clarified that [1] TSG-6 mRNA was expressed constitutively in cultured human uterine cervical fibroblasts, [2] expression of TSG-6 mRNA was upregulated in a dose dependent manner by proinflammatory cytokines, such as IL-1beta and TNF-alpha, which were key mediators in the cervical ripening process, [3] expression of TSG-6 mRNA in uterine cervices during parturition was significantly (P < 0.05) higher than that in a non-pregnant state.

CONCLUSIONS

Our results suggest that TSG-6 might participate in the cervical ripening process.

Up-regulation of cyclooxygenase-2 expression by TSG-6 protein in macrophage cell line

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.

Modified atherogenic lipoproteins induce expression of pentraxin-3 by human vascular smooth muscle cells

Inflammation is a critical contributing factor to the development and the progression of atherosclerosis. Recently, the acute-phase protein pentraxin-3 (PTX3), which has C-terminal sequence homology with the classic pentraxin C-reactive protein (CRP), was described to be increased in patients with myocardial infarction. In this study, we have investigated the capacity of human primary vascular smooth muscle cells (VSMC), derived from arterial specimens of ten different patients, to express PTX3 after incubation with atherogenic lipoproteins. Enzymatically degraded LDL (E-LDL), which is present in human early lesions, mediated a rapid cholesterol loading and foam cell transformation of primary VSMC, which was paralleled by a marked dose- and time-dependent expression of PTX3 mRNA and release of the acute-phase protein. Expression of PTX3 mRNA was delayed and remained almost undetectable for up to 6 h of incubation with E-LDL. However, during extended exposure to E-LDL for more than 24 h, PTX3 mRNA expression increased by more than 15-fold in VSMC foam cells, which was reflected by a concomitant release of up to 211 ng/ml PTX3 protein. We provide evidence for marked expression of PTX3 by VSMC induced by degraded lipoproteins, which may lead to an in situ vascular acute-phase reaction, contributing to the inflammatory pathogenesis of atherosclerosis.

The TSG-6 and IαI Interaction Promotes a Transesterification Cleaving the Protein-Glycosaminoglycan-Protein (PGP) Cross-link

During co-incubation of human inter-alpha-inhibitor (IalphaI) and human tumor necrosis factor-stimulated gene 6 protein (TSG-6) SDS-stable interactions are formed between the two proteins. We have analyzed the products of this reaction and characterized the mechanism of complex formation. Following the incubation seven new bands not previously identified were apparent in SDS-PAGE. Three of these bands did not contain TSG-6, including heavy chain (HC)1.bikunin, HC2.bikunin, and free bikunin. In addition high molecular weight complexes composed of the same components as I alpha I, including HC1, HC2, and bikunin, were formed. The formation of these complexes was prevented by the addition of hyaluronan. The cross-links stabilizing these complexes displaying properties similar to the protein-glycosaminoglycan-protein (PGP) cross-link. The TSG-6-containing SDS-stable complexes were composed of HC1.TSG-6 or HC2.TSG-6 exclusively. Both glycosylated and non-glycosylated TSG-6 participated in the complex formation. The HC.TSG-6 cross-links were different from the PGP cross-link and were determined to be ester bonds between the alpha-carbonyl of the C-terminal Asp of the heavy chain and most likely a hydroxyl group containing the TSG-6 residue. The mechanism involved cleaving the PGP cross-link of I alpha I during a transesterification reaction. A TSG-6 hydroxyl group reacts with the ester bond between the alpha-carbonyl of the C-terminal Asp residues of HC1 or HC2 and carbon-6 of an internal N-acetylgalactosamine of the chondroitin-4-sulfate chain. An intermediate is formed resulting in a partitioning of the reaction between HC(1 or 2).TSG-6 complexes and transfer of HC(1 or 2) to the chondroitin via competing pathways.

Cytokine-induced gene expression at the crossroads of innate immunity, inflammation and fertility: TSG-6 and PTX3/TSG-14

Two cytokine-inducible gene products, important in inflammation and infection, also play essential roles in female fertility. One of these is the product of tumor necrosis factor (TNF)-stimulated gene 6 (TSG-6), alternatively termed TNFAIP6 (for TNF-alpha-induced protein 6), originally cloned from diploid human fibroblasts stimulated with TNF. The second is pentraxin 3 (PTX3), also termed TSG-14, originally isolated from TNF-stimulated human fibroblasts and from interleukin-1 (IL-1)-stimulated vascular endothelial cells. TSG-6, which specifically binds to hyaluronan (HA) and to inter-alpha-inhibitor (I alpha I), shows potent anti-inflammatory activity in acute and chronic inflammation, notably in several models of autoimmune arthritis. PTX3 was shown to play an important role in resistance to fungal infection with Aspergillus fumigatus. Both TSG-6 and PTX3 are synthesized in the ovary prior to ovulation, where they become components of an expanding viscoelastic matrix that surrounds the oocyte before its release from the follicle at the ovarian surface. Female mice with a targeted disruption of either the TSG-6 or PTX3 gene show severe defects in fertility.

Enhanced neutrophil extravasation and rapid progression of proteoglycan-induced arthritis in TSG-6-knockout mice

OBJECTIVE

To gain insight into the mechanisms of the antiinflammatory effect of tumor necrosis factor alpha (TNFalpha)-induced protein 6 (Tnfip6) in arthritis, using Tnfip6-deficient animals.

METHODS

TNFalpha-stimulated gene 6 (TSG-6) coding for Tnfip6 was disrupted. Tnfip6-deficient mice were backcrossed into proteoglycan-induced arthritis (PGIA)-susceptible BALB/c mice, and arthritis was induced by systemic immunization with cartilage proteoglycan (PG). Thioglycollate-induced sterile peritonitis was also assessed, to monitor the early events of neutrophil extravasation in wild-type and Tnfip6-deficient mice in the presence or absence of treatment with recombinant murine Tnfip6.

RESULTS

The onset of PGIA was similar, but progression and severity were significantly greater, in Tnfip6-deficient mice compared with wild-type BALB/c mice. However, this was not associated with enhanced T or B cell responses to cartilage PGs, but rather, an early and more extensive infiltration of the synovium with neutrophil leukocytes was the most prominent histopathologic feature of PGIA in Tnfip6-deficient mice. This was accompanied by elevated serum levels of interleukin-6 and amyloid A, and significantly increased activities of the enzymes plasmin, myeloperoxidase, and neutrophil elastase in the inflamed paw joints of Tnfip6-null mice, when compared with that of the wild-type littermates. Loss of control over several components of inflammation resulted in extensive and rapid cartilage degradation, bone erosion, joint ankylosis, and deformities in Tnfip6-null animals. In support of the antiinflammatory effect of Tnfip6 via the inhibition of polymorphonuclear (PMN) cell efflux, neutrophil invasion during thioglycollate-induced peritonitis was 2-fold higher in Tnfip6-deficient animals than in wild-type animals, but was dramatically suppressed by intravenous injection of recombinant murine Tnfip6.

CONCLUSION

Tnfip6 is a multifunctional antiinflammatory protein that is produced at the site of inflammation and can be retained by the hyaluronan-rich extracellular matrix. A major effect of Tnfip6 is the inhibition of the extravasation of PMN cells, predominantly neutrophils, into the site of inflammation, most likely via a CD44/hyaluronan/Tnfip6-mediated blocking mechanism.

PTX3 function as an opsonin for the dectin-1-dependent internalization of zymosan by macrophages

Pentraxin 3 (PTX3) is a tumor necrosis factor and interleukin-1beta-stimulated gene that encodes a long PTX with proinflammatory activity. Here, we show that peritoneal macrophages derived from PTX3 transgenic (Tg) mice express higher levels of PTX3 mRNA than macrophages from wild-type (WT) mice, at basal level as well as upon stimulation with zymosan (Zy). Macrophages from Tg mice also showed improved opsonin-independent phagocytosis of Zy particles and the yeast form of the fungus Paracoccidioides brasiliensis. In the case of P. brasiliensis, an enhanced microbicidal activity accompanied by higher production of nitric oxide was also observed in macrophages from Tg mice. Using fluorescein-activated cell sorter analysis and reverse transcriptase-polymerase chain reaction, we demonstrated that basal level of Toll-like receptor-6 and Zy-induced dectin-1 expression was slightly but consistently higher in macrophages from Tg mice than in macrophages from WT mice. Recombinant (r)PTX3 protein binds to Zy particles as well as to yeast cells of P. brasiliensis and addition of rPTX3, to a culture of WT-derived macrophages containing Zy leads to an increase in the phagocytic index, which parallels that of Tg-derived macrophages, demonstrating the opsonin-like activity of PTX3. It is important that blockade of dectin-1 receptor inhibited the phagocytosis of Zy particles by WT and PTX3 Tg macrophages, pointing out the relevant role of dectin-1 as the main receptor involved in Zy uptake. Our results provide evidence for a role of PTX3 as an important component of the innate-immune response and as part of the host mechanisms that control fungal recognition and phagocytosis.

TSG-6: a multifunctional protein associated with inflammation

TSG-6 expression is upregulated in many cell types in response to a variety of proinflammatory mediators and growth factors. This protein is detected in several inflammatory disease states (e.g. rheumatoid arthritis) and in the context of inflammation-like processes, such as ovulation, and is often associated with extracellular matrix remodelling. TSG-6 has anti-inflammatory and chondroprotective effects in various models of inflammation and arthritis, which suggest that it is a component of a negative feedback loop capable of downregulating the inflammatory response. Growing evidence also indicates that TSG-6 acts as a crucial factor in ovulation by influencing the expansion of the hyaluronan-rich cumulus extracellular matrix in the preovulatory follicle. TSG-6 is a member of the Link module superfamily and binds to hyaluronan (a vital component of extracellular matrix), as well as other glycosaminoglycans, via its Link module. In addition, TSG-6 forms both covalent and non-covalent complexes with inter-alpha-inhibitor (a serine protease inhibitor present at high levels in serum) and potentiates its anti-plasmin activity.

Decreased expression of tumor necrosis factor-alpha-stimulated gene 6 in cumulus cells of the cyclooxygenase-2 and EP2 null mice

Ovulation, the release of fertilizable oocytes from mature follicles, involves tissue remodeling and increased prostaglandin (PG) signaling. Cyclooxygenase (COX)-2 is the rate-limiting enzyme during PG synthesis. Female mice null for either COX-2 or the PGE(2) receptor EP2 are infertile, show decreased ovulation, and exhibit abnormal cumulus expansion. Cumulus expansion is the production of a complex extracellular matrix surrounding the cumulus-oocyte complex (COC). Matrix components consist of hyaluronan, proteoglycans, and proteins with hyaluronan binding domains. One such hyaluronan binding protein is TNFalpha-stimulated gene 6 (TSG-6). By various methods, we show induction of TSG-6 and hyaluronan synthase-2 mRNA in ovaries of mice treated with pregnant mare serum gonadotropin and human chorionic gonadotropin. By in situ hybridization, we show that both genes are expressed in periantral mural granulosa cells and cumulus cells of the mouse ovary. Notably, RT-PCR and in situ hybridization show that TSG-6 mRNA but not hyaluronan synthase-2 mRNA expression is selectively reduced in cumulus cells of COX-2 and EP2 null mice. Western analysis further confirms that TSG-6 protein is reduced in isolated COCs but remains covalently associated with inter alpha-trypsin inhibitor in COX-2 null mice. These observations identify TSG-6 as a target of PG action and show that its production in ovulatory follicles is associated with proper formation of the cumulus-derived extracellular matrix.