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)

The effect of bradykinin (BK) on proteinase activity, prostaglandin synthesis, and the production of interleukin-6 (IL-6) was investigated in cultures of human osteoblast-like cells. Bradykinin had no effect on stromelysin activity and plasminogen activator activity produced by human osteoblast-like cells. However, BK stimulated the production of prostaglandin E2, an effect that was markedly enhanced by pre-incubation with recombinant interleukin-1 alpha (rhIL-1 alpha), but was apparently unaffected by BK receptor antagonists types 1 and 2. Bradykinin stimulated the intracellular accumulation of total inositol phosphates suggesting that its effects were mediated by stimulation of phosphoinositide metabolism. Bradykinin within the dose range of 10(-11)-10(-5) M also significantly stimulated the production of IL-6. Bradykinin may, therefore, mediate a variety of responses in bone under both physiological and pathological conditions.
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PMID:Bradykinin stimulates the production of prostaglandin E2 and interleukin-6 in human osteoblast-like cells. 159 Dec 76

The gene expression of five matrix metalloproteinases (MMPs) and two tissue inhibitors of metalloproteinases (TIMPs) was studied in human gliomas in vivo and in vitro to evaluate their roles in glioma invasion. Simultaneous expression of one to four MMP genes and two TIMP genes was found in 17 surgical glioma specimens, and one MMP (gelatinase A) gene and two TIMP genes were simultaneously expressed in tissue of three brains. The concomitant overexpression of gelatinase A, gelatinase B, and occasional matrilysin genes was associated with the malignancy of gliomas and accompanied by overexpression of the TIMP-1 gene. In five human glioma cell lines, gelatinase A, TIMP-1, and TIMP-2 genes were constitutively expressed in alll cell lines: the matrilysin gene in three cell lines; the stromelysin gene in two cell lines; and the interstitial collagenase gene in one cell line. There was a clear difference in the expression of gelatinase B and stromelysin genes between surgical glioma specimens and glioma cell lines: the gelatinase B gene was not expressed constitutively in vitro but was overexpressed in vivo, whereas the stromelysin gene was not expressed in vivo but was expressed in some cell lines. To find the cause of that difference in vivo and in vitro, the transcriptional regulations of MMP and TIMP genes by tumor promoter, growth factors, or cytokines were studied in vitro. Interstitial collagenase, gelatinase B, stromelysin, and TIMP-1 genes were upregulated in many cell lines by phorbol-12-myristate-13-acetate (PMA) and in some cell lines by epidermal growth factor, tumor necrosis factor-alpha, or interleukin-1 beta. Transforming growth factor-beta 1 (TGF beta 1) upregulated gelatinase A and matrilysin genes in some cell lines, and there were no clear responses from any MMP and TIMP genes to interleukin-6. Thus, the transcriptional modulation of MMP genes by these growth factors and cytokines seemed insufficient to explain the difference in gelatinase B and stromelysin gene expressions in vivo and in vitro and was suggestive of the genetic alteration of glioma cells in vitro, the heterogeneous cell population in glioma tissues, or both. Furthermore, the in vitro invasion of glioma cells through Matrigel in response to PMA, TGF beta 1, or TIMP-1 was assessed by chemoinvasion assay. In most cell lines, invasion was significantly stimulated by PMA or TGF beta 1 but suppressed by TIMP-1.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Matrix metalloproteinases and tissue inhibitors of metalloproteinases in human gliomas. 761 76

The in-vitro effects of avocado and soybean unsaponifiable residues on neutral metalloproteinase activity, cytokines and prostaglandin E2 (PGE2) production by human articular chondrocytes were investigated. Avocado and soybean unsaponifiable residues were mixed in three ratios: 1:2 (A1S2), 2:1 (A2S1) or 1:1 (A2S2). Freshly isolated human chondrocytes were cultured for 72 h in the absence or presence of interleukin-1beta, (IL-1beta) (17 ng/ml), with or without unsaponifiable residue mixtures at a concentration of 10 microg/ml. A/S unsaponifiable residues were also tested separately at concentrations of 3.3, 6.6 and 10 microg/ml. All A/S unsaponifiable mixtures reduced the spontaneous production of stromelysin, interleukin-6 (IL-6), interleukin-8 (IL-8) and prostaglandin E2 (PGE2) by chrondrocytes. At concentrations of 3.3 and 6.6 microg/ml, A/S residues, tested separately, were potent inhibitors of the production of IL-8 and PGE2. Nevertheless, only avocado residue inhibited IL-6 production at these concentrations. A/S unsaponifiable mixtures had a more pronounced inhibitory effect on cytokine production than avocado or soybean residues added alone. As anticipated, IL-1beta induced a marked release of collagenase, stromelysin, IL-6, IL-8 and PGE2. A/S unsaponifiable mixtures partially reversed the IL-1 effects on chrondrocytes. These findings suggest a potential role for A/S unsaponifiable extracts in mitigating the deleterious effects of IL-1beta: on cartilage.
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PMID:Effects of three avocado/soybean unsaponifiable mixtures on metalloproteinases, cytokines and prostaglandin E2 production by human articular chondrocytes. 958 76

The addition of fibronectin fragments to cultured cartilage causes an initial suppression of proteoglycan synthesis, induction of matrix metalloproteinases, and resultant decrease in proteoglycan content by about 50% during the first few days in culture. Because the proteoglycan loss appears to be limited, we investigated whether the fibronectin fragments induce anabolic responses that might counter the damage. The effects of various lengths of exposure of cultured cartilage to the fibronectin fragment on proteoglycan content, proteoglycan synthesis rates, stromelysin-1 release, and tumor necrosis factor-alpha, interleukin-1alpha, and interleukin-6 release were investigated. The results showed that about 7 days of exposure of cultured cartilage to the fibronectin fragment was required for maximal cytokine release, proteoglycan depletion, and stromelysin-1 release. However, nearly maximal suppression of proteoglycan synthesis occurred within 1 day of the addition of the fibronectin fragment and, after its removal, the rates increased to supernormal levels. Decreasing exposure to 3 days caused only a small decrease in cartilage proteoglycan content, although stromelysin-1 release still occurred. Decreasing exposure to 1 day caused an immediate increase in proteoglycan synthesis and an increase to supernormal proteoglycan contents. The effect of first treating cartilage with the fibronectin fragment for various periods and then allowing a recovery was to make the cartilage more resistant to secondary exposures. This study shows that cartilage damage can be caused by short exposures to the fibronectin fragment and that exposures either optimal or suboptimal for damage additionally amplify anabolic processes to make the cartilage resistant to further damage and, thus, condition it against pending amplification of damage.
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PMID:Exposure of cartilage to a fibronectin fragment amplifies catabolic processes while also enhancing anabolic processes to limit damage. 962 98

Ultraviolet-B irradiation of human dermal fibroblasts has earlier been shown to induce matrix-degrading metalloproteinases, thus driving connective tissue degradation in photoaging and photocarcinogenesis. Herein, we report that Ultraviolet-B irradiation led to a dramatic increase in specific mRNA and protein levels of interstitial collagenase, stromelysin and interleukin-6. By contrast, the major tissue inhibitor of matrix-degrading metalloproteinases, TIMP-1, was unaffected. Monospecific neutralizing antibodies directed against human interleukin-6 significantly reduced the interstitial collagenase and stromelysin-1 protein levels. Taken together, our data provide the first evidence that Ultraviolet-B induction of interstitial collagenase and stromelysin-1 occurs via the synthesis and release of interleukin-6. Hence, this newly identified autocrine mechanism may contribute to dermal photodamage.
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PMID:Ultraviolet-B induction of interstitial collagenase and stromelyin-1 occurs in human dermal fibroblasts via an autocrine interleukin-6-dependent loop. 1022 23

Sex steroids are important regulators of bone cell function and osteoblast-derived matrix metalloproteinases (MMPs) are key mediators of bone resorption during the initial stage of osteoid removal prior to osteoclast attachment. To investigate the mechanism of bone loss following estrogen deficiency, we examined the effects of estrogen on osteoblast synthesis of MMPs and tissue inhibitor of metalloproteinases (TIMPs). Immunolocalization in mouse bone samples ex vivo and primary mouse osteoblast (MOB) cultures was used to document the synthesis of mouse interstitial collagenase (MMP-13), stromelysin-1 (MMP-3), gelatinase-A (MMP-2), and gelatinase-B (MMP-9). Endosteal bone lining cells from distal femoral head and lumbar vertebral body showed an increase in the pattern of synthesis of stromelysin-1 following ovariectomy, compared with sham-operated controls; the synthesis of other MMPs was unaffected. The expression of all classes of MMPs and TIMP-1 and TIMP-2 by MOB in culture was demonstrated by reverse transcriptase-polymerase chain reaction. Following the withdrawal of 17beta-estradiol, MOB cultures showed a significant increase in the number of cells synthesizing stromelysin-1; this effect was enhanced by stimulation with either interleukin-1 or interleukin-6. Northern blot analysis showed only a slight increase in stromelysin-1 mRNA message following the withdrawal of 17beta-estradiol. Our data show an unexpected up-regulation of stromelysin-1 synthesis by osteoblasts both in vivo and in vitro following estrogen withdrawal. Although this effect was not reflected in a significant change in stromelysin-1 mRNA expression in vitro, there is evidence to suggest a role for this enzyme in the early stages of bone loss during the pathogenesis of osteoporosis.
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PMID:Stromelysin (MMP-3) synthesis is up-regulated in estrogen-deficient mouse osteoblasts in vivo and in vitro. 1057 88

The functional 5A/6A polymorphism of the stromelysin-1 promoter has been implicated as a potential genetic marker for the progression of angiographically determined atherosclerosis in patients with coronary artery disease. Recently, a novel interleukin-6 (IL-6) gene functional G/C polymorphism at -174 in the promoter has also been reported. In this study, we analyzed the relation of these two polymorphisms with carotid artery atherosclerosis in 109 randomly selected, middle-aged men without exercise-induced ischemia. Atherosclerosis was quantified as intima-media thickness (IMT) by high-resolution ultrasonography. Univariately, stromelysin genotype was significantly (P:=0.015) associated with IMT, and this relation remained (P:=0.033) after adjustments for age, cardiorespiratory fitness, body mass index, smoking, LDL cholesterol, and systolic blood pressure and for sonographers. The 5A/6A polymorphism independently explained 7% of the variance in carotid bifurcation IMT. The IL-6 polymorphism was also significantly associated (P:=0. 036) with increased IMT, with men homozygous for the G allele having IMT that was 11% greater than men homozygous for the C allele. Men who were homozygous for both the 6A and G alleles had an covariate adjusted IMT that was 36% greater than men who were homozygous for neither allele (P:<0.003). These data suggest that genetic factors that predispose to reduced matrix remodeling (stromelysin 6A allele) and to increased inflammation (IL-6 G allele) combine to increase susceptibility for intima-media thickening in the carotid bifurcation, a predilection site for atherosclerosis.
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PMID:Stromelysin-1 and interleukin-6 gene promoter polymorphisms are determinants of asymptomatic carotid artery atherosclerosis. 1111 68

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


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