Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In our RT-PCR screen for cytokine expression in human brain tumors we discovered increased levels of oncostatin M (OSM), ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF), all belonging to the interleukin-6 (IL-6) cytokine family, in most of the tumors. The expression of these cytokines in normal adult brain tissue was found to be very low or below detection limit. OSM expression was elevated in most of the tumors and immunohistochemistry analysis showed that the tumor cells contained OSM in their cytoplasm, suggesting they produce this factor. Overexpression of OSM has not previously been reported in primary human brain tumors. The IL-6 cytokine family acts through a common gp130 receptor subunit that activates the JAK/STAT signaling pathway and therefore they have been suggested to have overlapping effects. Tissue inhibitor of metalloproteinase-1 (TIMP-1), matrix metalloproteinase 1 (MMP-1) and MMP-3 and IL-6 have been reported to be regulated by OSM. IL-6 was low or absent in the tumors. TIMP-1, MMP-1 and MMP-3 was expressed in most tumors but with no strict correlation to OSM levels.
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PMID:Expression of the IL-6 family cytokines in human brain tumors. 1149 26

Cytokines and proteases are secreted by fibroblasts in response to particulate wear debris, and these proteins are felt to play an important role in the development of osteolysis and implant loosening. Although metallic and polyethlyene debris have been studied extensively, little is known about the cellular responses to hydroxyapatite, despite the wide clinical use of these materials. Therefore, the effects of hydroxyapatite (HA) and hydroxyapatite/beta-tricalciumphosphate (HA/TCP) on cellular proliferation, cytokine gene expression and protein secretion, protease synthesis, and gelatinolytic activity were investigated in human fibroblasts. HA and HA/TCP particles were synthesized, and their effects were compared to the responses elicited by titanium and cobalt chromium. Sample characterization by scanning electron microscopy and Coulter Counter demonstrated that the materials had a mean particle size of less than 10 microm, and all of the particles were compared using the same concentration ranges. Aliquots of particle suspensions were added to human fibroblasts maintained in tissue culture, and dose-response and time-course experiments were performed. Effects of the particles on fibroblast proliferation were assessed, and alterations in cytokine levels were determined by specific enzyme linked immunosorbent assays (ELISA). Cytokines that were evaluated included interleukin-1 (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha), all of which have been demonstrated to enhance bone resorption and are associated with osteolysis and implant loosening. Gene expression was determined using Northern blot analysis with cytokine-specific probes, while secretion of the proteases collagenase and stromelysin was determined by Western blot analysis. Functional gelatinolytic assay was assessed using zymogram gels. The particles were evaluated in a concentration range from 0.000021 to 0.021 vol%. All of the particles produced increases in cellular proliferation up to 0.0021 vol%, with the largest increases being seen at 0.021 vol% with HA/TCP and titanium. At the highest concentration, both cobalt chromium and HA samples decreased cellular proliferation relative to lower doses, possibly representing cytotoxicity. Hydroxyapatite particles yielded a 30-fold increase in interleukin-6 secretion compared to unstimulated controls, which was also greater than three times the levels produced by cobalt chromium, titanium, or HA/TCP. HA particles also tripled the secretion of IL-1beta at 0.00021 vol%, and doubled TNF-alpha secretion at 0.021 vol%. Addition of conditioned media prepared by incubation of the particles in culture medium in the absence of cells did not alter the secretion of any of the cytokines. Northern blot analysis using IL-6 probes also demonstrated strong increases with HA compared to the other materials, suggesting that the action of the HA particles was at the level of transcription. Secretion of the protease collagenase was increased by all of the samples including HA when compared to unstimulated controls. Stromelysin secretion into the culture medium was decreased by cobalt chromium, but increased by titanium, HA, and HA/TCP. All of the particles including HA increased the gelatinolytic activity of the fibroblasts. These findings demonstrate that HA and HA/TCP particles are capable of stimulating the expression and secretion of cytokines and proteases that enhance bone resorption, and suggest that particulate debris from implants using these coatings may also increase osteolysis and loosening.
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PMID:Effects of hydroxyapatite particulate debris on the production of cytokines and proteases in human fibroblasts. 1151 71

Total hip arthroplasty (THA) has provided dramatic pain relief and improvement in function for millions of patients with end-stage arthritis; however, periprosthetic osteolysis following THA has become increasingly recognized as a major clinical problem in both cemented and cementless reconstructions. An aggressive granulomatous tissue (interfacial membrane) consisting predominantly of fibroblasts, aggregates of macrophages, and foreign body giant cells develops at the interface of bone/prostheses or bone/cement. It is believed that particulate wear debris from prosthetic materials and/or bone cement are phagocytized by histiocytic cells of interfacial membrane and then these cells produce inflammatory mediators and proteolytic enzymes to provoke a cascade of osteolytic events. In this paper, we studied in vitro responsiveness of various cell types to particulate wear debris. Although titanium and titanium alloys demonstrate excellent biocompatibility in bulk from, titanium in particulate form can provoke a variety of cellular responses. We have found that small-sized Ti particles of phagocytosable size, a commonly encountered particle species in the periprosthetic tissues of failed THAs, stimulate macrophages to secrete various mediators of bone resorption (prostaglandin E(2), interleukin-1, interleukin-6, and tumor necrosis factor-alpha from macrophages and cause bone resorption in organ culture. In addition, we have shown that phagocytosable titanium particles stimulate fibroblasts to up-regulate the expression of matrix metalloproteinases (stromelysin and collagenase) without a substantial effect on the tissue inhibitor of these enzymes (TIMP). Titanium particulates also have a suppressive effect on procollagen synthesis by osteoblast-like cell line. Thus, titanium particulates have the capacity to stimulate bone resorption and inhibit bone matrix formation. In this series of experiments, we have also shown in vitro inhibitory effect of certain pharmaceutical components (indomethacin, misoprostol) upon bone resorption in organ culture, which may indicate a potential therapeutic intervention to prevent or treat particulate-induced pathological bone resorption in total joint arthroplasties.
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PMID:Particulate-Induced, Prostaglandin- and Cytokine-Mediated Bone Resorption in an Experimental System and in Failed Joint Replacements. 1185 95

STAT3, a member of signal transducers and activators of transcription (STATs) originally discovered as mediators in cytokine signaling pathways, plays an active role in oncogenesis. However, the function of STAT3 in signaling multistage carcinogenesis, especially in transformation of tumor-promotion sensitive epithelial cells has not been elucidated. The present study demonstrates that STAT3 is activated in interleukin-6 induced transformation in mouse skin epithelial cells. DNA binding and transcriptional activities of STAT3 were significantly increased by interleukin-6. This induced anchorage-independent transformation in tumor-promotion sensitive JB6 mouse skin P+ cells but not in the resistant variant P- cells. Two forms of dominant negative STAT3 (mutant of transcriptional domain, mF, or DNA-binding domain, mD) were stably transfected into P+ cells. Activation of STAT3 was abolished and importantly, interleukin-6 induced anchorage-independent growth was absent in both mutant STAT3 transfectants. To determine the genes targeted by STAT3, three matrix metalloproteinase proteins linked with carcinogenesis of epithelial cells were analysed. Both basal and interleukin-6 induced expression of collagenase I and stromelysin I, but not gelatinase A, were inhibited in the mutant STAT3 transfectants. Furthermore, transfection of a wild type STAT3 restored STAT3 transactivation and response to interleukin-6 induced transformation in mutant STAT3 transfectants, which up-regulated collagenase I and stromelysin I as well. Together, these results provide the first evidence that STAT3 activation is required in the progression of multistage carcinogenesis of mouse skin epithelial cells, and matrix metalloproteinases are actively involved in STAT3-mediated cell transformation.
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PMID:STAT3 activation is required for interleukin-6 induced transformation in tumor-promotion sensitive mouse skin epithelial cells. 1203 77

The aim of this study was to investigate the metabolic properties of human articular chondrocytes derived from young, aged and osteoarthritic subjects and their genetic adaptation to a catabolic challenge (i.e. the inflammatory cytokines interleukin-1alpha and tumor necrosis factor-alpha), in the absence or presence of diacerein, a drug potentially useful in osteoarthritis. Chondrocytes in primary culture were analyzed for newly secreted proteins, metalloproteinase synthesis and activity, and production of nitric oxide by-products. Results show that chondrocytes from normal but aged subjects present biochemical properties closer to osteoarthritic-derived cartilage than to normal young cartilage, as indicated by cell morphology, cell proliferation rate and pattern of protein secretion (in particular stromelysin-1 and interstitial collagenase). According to patient age and cartilage physiopathology, chondrocytes secrete increasing amounts of a protein identified by micro-sequencing as chitinase-like protein. Upon exposure to the inflammatory cytokines, chondrocytes, regardless the age or the status of the donor, significantly enhance their production of stromelysin-1, interstitial collagenase, interleukin-6 and interleukin-8. By contrast, the chitinase-like protein is not modulated by the cytokines. The pattern of protein secretion and metalloproteinase activity in chondrocytes from aged subjects appeared to be different from that of young patients, but was highly expressed in osteoarthritic chondrocytes. Diacerein, at therapeutically useful concentrations, consistently counteracts the stimulatory effect of cytokines on newly secreted proteins, metalloproteinase activity and nitric oxide production, whereas a selective nitric oxide blocker alone is ineffective. These data demonstrate that a specific gene program is turned on in cytokine-stimulated chondrocytes, which involves production of proteins engaged in remodeling and destruction of cartilage matrix. Part of these mechanisms appears to be operative also in unstimulated aged chondrocytes. Diacerein largely prevents the metabolic alterations caused by cytokine exposure in human chondrocytes, possibly through its ability to block early intracellular mediators after cytokine stimulation, such as oxygen radicals.
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PMID:Response of young, aged and osteoarthritic human articular chondrocytes to inflammatory cytokines: molecular and cellular aspects. 1222 10

Excessive production of interleukin-6 (IL-6) and metalloproteinases (MMPs) have been implicated in the pathogenesis of rheumatoid arthritis. Lipoxin A4 (LXA4) and transforming growth factor beta 2 (TGF-beta 2), mediators with potential anti-inflammatory activities, were tested to determine how they affect IL-1 beta-dependent release of IL-6 and MMPs in human fibroblast like synoviocytes. The results showed dramatic differences between the mediators: TGF-beta 2 acted synergistically with IL-1 beta to stimulate IL-6 protein levels, whereas LXA4 inhibited IL-6 expression in dose- and time-dependent manner. Inhibition, by LXA4 was abrogated when cells were pre-incubated with antibody against the LXA4R whereas TGF-beta 2 by itself had no significant effect on IL-6 or MMP levels. LXA4, at nanomolar concentrations, altered the MMP-1 and MMP-3 expression levels of IL-1 beta and TGF-beta 2 stimulated fibroblast like synoviocytes at 5 days. Furthermore, IL-1 beta and TGF-beta 2 up-regulated LXA4R mRNA. These results demonstrate, for the first time, that LXA4Rs mediate the effects of LXA4 on inflammatory responses after combined stimulation of human fibroblast like synoviocytes with IL-1 beta and TGF-beta 2. These activities might constitute an important mechanism by which LXA4 regulates human synovial fibroblast activation.
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PMID:Lipoxin A4 counteracts synergistic activation of human fibroblast-like synoviocytes. 1500 Aug 62

The structural rearrangement of collagen fibres in hypertrophic scar causes abnormal contracture, low tensile strength, and raised scars, which cause functional impairment and disfigurement. It is hypothesized that changes in the genes of cytokines, extracellular matrix proteins, and proteins regulating programmed cell death are related to hypertrophic scar formation. To test this hypothesis, fibroblasts were cultured from hypertrophic scars and their response to interleukin-6 (IL-6) stimulation was studied by defining their gene expression profiles. Affymetrix gene chip analysis was used to identify up- or down-regulation in the 12 625 genes present in the affymetrix array. RT-PCR and ELISA assays were used to validate microarray expression profiles further. Comparison of gene profiles showed an increase of 12 genes in hypertrophic scar fibroblasts compared with normal skin fibroblasts, while the expression of 14 genes decreased. Thirty-three genes were affected by IL-6 treatment in the hypertrophic scar fibroblasts, while 57 genes were affected in normal skin fibroblasts. Messenger RNA to beta-actin ratios for matrix metalloproteinase-1 (MMP-1) and MMP-3 were increased with IL-6 in normal skin fibroblasts from 2.43 +/- 0.06 to 5.50 +/- 0.45 and from 0.75 +/- 0.09 to 1.98 +/- 0.01, respectively. No change in these matrix metalloproteinases could be shown with IL-6 stimulation in hypertrophic scar fibroblasts. Secreted protein levels of pro-MMP-1 and MMP-3 were elevated in the supernatants from normal skin fibroblasts from 2.00 +/- 0.09 and 1.72 +/- 0.10 ng/ml to 4.60 +/- 0.12 and 3.41 +/- 0.20 ng/ml, respectively, after treatment with IL-6 (p < 0.05). No changes were observed in hypertrophic scar fibroblasts treated with IL-6. Values are means +/- SEM. The absence of any up-regulation of MMP-1 and MMP-3 in hypertrophic scar fibroblasts, in response to IL-6, suggests that suppression of matrix metalloproteinases may play a role in the excessive accumulation of collagen formed in hypertrophic scars. While the pathogenesis of abnormal hypertrophic scars remains poorly understood, the use of gene expression arrays may prove helpful in identifying the mechanisms responsible for this type of abnormal scar formation and in formulating an effective therapeutic protocol.
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PMID:Gene expression profiles from hypertrophic scar fibroblasts before and after IL-6 stimulation. 1509 75

Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of infrared radiation on skin aging. In addition to photons, heat is likely to be generated as a consequence of infrared irradiation, and heat shock is widely considered to be an environmental stress. Here we investigated the effect of heat shock on the expressions of matrix metalloproteinase (MMP)-1, MMP-2, and MMP-3 in cultured human skin fibroblasts. Heat shock induced the expression of MMP-1 and MMP-3, but not MMP-2, at the mRNA and protein levels in a temperature-dependent manner, and caused the rapid activation of three distinct mitogen-activated protein kinases (MAPK), extracelluar signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. The heat shock-induced MMP-1 and MMP-3 expression was suppressed by the inhibition of ERK and JNK but not by p38 MAPK inhibition. Furthermore, heat shock increased the synthesis and release of interleukin-6 (IL-6) into culture media. The specific inhibition of IL-6 using a monoclonal antibody against IL-6 greatly reduced the expression of MMP-1 and MMP-3 induced by heat shock. Taken together, our results suggest that ERK and JNK play an important role in the induction of MMP-1 and MMP-3 by heat shock and that the heat shock-induced expression of MMP-1 and MMP-3 is mediated via an IL-6-dependent autocrine mechanism.
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PMID:Heat shock-induced matrix metalloproteinase (MMP)-1 and MMP-3 are mediated through ERK and JNK activation and via an autocrine interleukin-6 loop. 1561 May 7

Tumor embolism occurs in 30 to 50% of all cases of cardiac myxoma, but the causes are still uncertain. Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade the extracellular matrix (ECM) and play a crucial role in plaque instability and aortic aneurysm development, in addition to cancer and heart failure. To determine whether MMP activity contributes to tumor embolism, we examined 27 left atrium-sided myxomas, 10 of which showed clinical signs of peripheral embolism. Immunohistochemistry (in all cases) and Western blotting, and in situ and in-gel zymography (in four embolic and six nonembolic consecutive tumors) demonstrated higher expression and activity of MT1-MMP, pro-MMP-2, and pro-MMP-9 in embolic myxomas, whereas pro-MMP-1, MMP-3, and TIMP-1 levels were similar to those of nonembolic tumors. Reverse transcriptase-polymerase chain reaction demonstrated that increased MMP activity was due, at least in part, to increased transcription and that TIMP-2 transcripts increased in embolic myxomas. In vitro, embolic tumor cells retained higher MT1-MMP and pro-MMP-2 levels in basal conditions and after stimulation with interleukin-1beta and interleukin-6. Increased MMP synthesis and release correlated with enhanced ECM degradation products containing glycosaminoglycan chains in embolic myxoma tissue. Our results strongly suggest that MMP overexpression may contribute to an excessive degradation of tumor ECM and increase the risk of embolism in cardiac myxomas.
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PMID:Increased expression and activity of matrix metalloproteinases characterize embolic cardiac myxomas. 1592 Jan 47

Seventy-three samples of acute wound fluid were collected from 47 patients during the first 3 postoperative days (POD) following mastectomy for cancer (n=47 on POD-1, n=19 on POD-2, and n=7 POD-3). Samples were analyzed by enzyme-linked immunosorbent assay for growth factor levels (epidermal [EGF], platelet-derived [PDGF], basic fibroblast [bFGF], transforming growth factor-beta1 [TGF-beta1], vascular endothelial [VEGF]), interleukin-6 (IL-6), matrix metalloproteinases (MMPs-2, -3, -9), and the tissue inhibitor of metalloproteinase 1 (TIMP-1). The levels of EGF, bFGF, PDGF, and interleukin-6 peaked on POD-1, with a significant decrease by POD-3, while total and active MMP-2, MMP-3, and tissue inhibitor of metalloproteinase 1 showed a progressive and significant increase from days 1 to 3. The wounds that later developed an infection (11%) were found to have a significantly lower PDGF and EGF on day 1 (PDGF, median 169 pg/mL [range, 86-2,595]) than the noninfected wounds (2,098 [17-66,506] p<0.05, Mann-Whitney U-test). Sixty-two percent patients developed a seroma and the levels of bFGF were significantly less in these patients (441 pg/mL [45-4,108]) than in those patients where there was no seroma (807 [245-3,133] p<0.05). The levels of certain growth factors in acute wound fluid may be important markers for wound outcomes.
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PMID:Temporal and quantitative profiles of growth factors and metalloproteinases in acute wound fluid after mastectomy. 1808 93


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