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 27E10 antigen is a heterodimer of MRP8 and MRP14, two Ca(2+)-binding proteins related to the S-100 protein family. Previous studies have shown that 27E10 epitope-bearing monocyte subsets are prevalent in early acute but absent in chronic inflammatory conditions. These observations further provide an impetus for identifying the cellular mechanisms responsible for the appearance of different monocyte subpopulations during inflammation. Therefore this in vitro study was carried out to investigate the influence of adhesion in inducing 27E10-positive subsets. In adhesion assays the role of 27E10 antigen in spontaneous adherence was obvious, as a monoclonal antibody directed against the 27E10 antigen significantly inhibited the adherence of monocytes to collagen and fibronectin. In contrast, these extracellular matrix (ECM) proteins induce the cell surface expression and association of 27E10 antigen with cytoskeleton (CSK), detected by flow cytometry and confocal laser scan microscopy, respectively. Similar results were obtained on cross-linking with specific antibodies, thus showing involvement of the integrin molecules VLA-2 and VLA-4. In addition, the association with CSK could be confirmed by differential detergent extraction. The observed redistribution of 27E10 antigen guided by collagen compared with fibronectin was also paralleled by an augmented release of inflammatory cytokines interleukin-6, tumor necrosis factor alpha, and superoxide anions. Thus, this study demonstrates that under inflammatory conditions the interactions of extravasating monocytes with the ECM may induce an activated phenotype of monocytes marked by 27E10.
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PMID:Heterodimers of the calcium-binding proteins MRP8 and MRP14 are expressed on the surface of human monocytes upon adherence to fibronectin and collagen. Relation to TNF-alpha, IL-6, and superoxide production. 782 73

Long-term bone marrow cultures (LTBMC) from patients with multiple myeloma (MM) and normal donors were analyzed for immunophenotype and cytokine production. Both LTBMC adherent cells from myeloma and normal donor origin expressed CD10, CD13, the adhesion molecules CD44, CD54, vascular cell adhesion molecule 1, very late antigen 2 (VLA-2), and VLA-5, and were positive for extracellular matrix components fibronectin, laminin, and collagen types 3 and 4. LTBMC from myeloma patients and normal donors spontaneously secreted interleukin-6 (IL-6). However, levels of IL-6 correlated with the stage of disease; highest levels of IL-6 were found in LTBMC from patients with active myeloma. To identify the origin of IL-6 production, LTBMC from MM patients and normal donors were cocultured with BM-derived myeloma cells and cells from myeloma cell lines. IL-6 was induced by plasma cell lines that adhered to LTBMC such as ARH-77 and RPMI-8226, but not by nonadhering cell lines U266 and FRAVEL. Myeloma cells strongly stimulated IL-6 secretion in cocultures with LTBMC adherent cells from normal donors and myeloma patients. When direct cellular contact between LTBMC and plasma cells was prevented by tissue-culture inserts, no IL-6 production was induced. This implies that intimate cell-cell contact is a prerequisite for IL-6 induction. Binding of purified myeloma cells to LTBMC adherent cells was partly inhibited by monoclonal antibodies against adhesion molecules VLA-4, CD44, and lymphocyte function-associated antigen 1 (LFA-1) present on the plasma cell. Antibodies against VLA-4, CD29, and LFA-1 also inhibited the induced IL-6 secretion in plasma cell-LTBMC cocultures. In situ hybridization studies performed before and after coculture with plasma cells indicated that LTBMC adherent cells produce the IL-6. These results suggest that the high levels of IL-6 found in LTBMC of MM patients with active disease are a reflection of their previous contact with tumor cells in vivo. These results provide a new perspective on tumor growth in MM and emphasize the importance of plasma cell-LTBMC interaction in the pathophysiology of MM.
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PMID:Primary tumor cells of myeloma patients induce interleukin-6 secretion in long-term bone marrow cultures. 791 45

To assess the effect of interleukin-6 (IL-6) on the coagulation and the fibrinolytic systems, we administered a single subcutaneous injection of recombinant glycosylated human interleukin-6 (r-hIL-6) 100 micrograms per kg body weight) to four baboons (Papio ursinus). Four saline injected baboons served as controls. In serial plasma or serum samples collected over a period of seven days we measured several key parameters of the coagulation and the fibrinolytic systems, IL-6 and a set of acute phase proteins. Three hours after the injection, the serum IL-6 levels peaked at 50 ng/ml and then gradually declined with a terminal half-life of around 4 hours. The biological efficacy was demonstrated by the significant increases of several acute phase proteins, circulating platelets and the decrease of prealbumin and fibronectin. Between days 1 and 3, marked effects on the coagulation system were observed with a prolongation of the activated partial thromboplastin time, prothrombin time and thrombin time. Plasma concentrations of fibrinopeptide A and D-dimer increased. The antithrombin III antigen and activity levels decreased, but the thrombin-antithrombin III complex concentrations did not change. The fibrinolytic system rapidly showed striking modifications after 6-8 hours, the concentrations of tissue-type plasminogen activator and of plasminogen activator inhibitor type 1 peaked at respectively four and thirty times the basal concentrations. No changes were seen in the control group. We conclude that besides its well-known acute phase inducing and hematopoietic activities, subcutaneous rhIL-6 also modulates several parameters of the coagulation and the fibrinolytic systems.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vivo modulation of coagulation and fibrinolysis by recombinant glycosylated human interleukin-6 in baboons. 794 65

Because fibronectin (FN) is known to be present in membranes in proliferative vitreoretinopathy, we sought to identify cytokines that regulate the release of FN by retinal pigment epithelial cells (RPE). Levels of FN in the supernatant of cultured human RPE cells were quantified with an ELISA, after which the cells were stimulated with human recombinant cytokines, interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), interferon gamma (IFN-gamma), transforming growth factor beta 1 and 2 (TGF-beta), and phorbol myristate acetate (PMA). Protein kinase C (PKC) was blocked by 2 nM calphostin C or 1 mM staurosporine. RPE cells released FN into the supernatant constitutively. TGF-beta 1 and TGF-beta 2 upregulated the FN release in a dose- and time-dependent manner. The other cytokines tested were without effect. In combination, IFN-gamma and IL-1 beta reduced the effect of TGF-beta. PMA, which is a PKC activator, also increased the release of FN in a dose-dependent manner. Blocking of PKC with specific inhibitors abolished the effects of TGF-beta and PMA. The results show that TGF-beta is a potent stimulator of FN release by RPE cells, and exerts its effects via signal transduction involving PKC. Its effect is reduced by IFN-gamma.
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PMID:Cytokine effect on fibronectin release by retinal pigment epithelial cells. 795 9

Multiple myeloma is characterized by the presence of malignant plasma cells predominantly localized in bone marrow. Our prior studies have suggested that human myeloma derived-cell lines adhere specifically to fibronectin and to bone marrow stromal cells (BMSCs) via beta 1 and beta 2 integrins as well as RGD peptide, and that tumour cell to BMSC contact triggers interleukin-6 (IL-6) secretion from BMSCs. Since IL-6 is a growth factor for myeloma, adhesion may be important in paracrine IL-6 mediated tumour cell growth. We therefore examined phenotypic expression of adhesion molecules on the U266 and IM-9 human myeloma-derived cell lines using the panel of monoclonal antibodies (MoAbs) directed at adhesion molecules submitted to the Vth International Conference on Human Leukocyte Differentiation Antigens. U266 and IM-9 myeloma cell lines express mainly CD29, CD49d, VLA-1, CD18, CD54, ICAM-2 and ICAM-3. In contrast, CD49b, VLA-3, CD49f, CD11b, VCAM-1, selectins and selectin-ligands were not expressed on these cell lines. Specific adherence of IM-9 cells to BMSC line LP101 was demonstrated which could be partially blocked by pre-incubation and culture of tumour cells with anti-beta 1 integrin, anti-beta 2 integrin, anti-CD49d, anti-VLA-5, anti-CD11a, anti-CD44 and anti-CD54 MoAbs. The combination of these MoAbs (anti-CD29, CD18, CD11a, CD49d, VLA-5, CD44, CD54, ICAM-2, ICAM-3 MoAbs) decreased but did not completely abrogate binding of IM-9 to BMSCs. Moreover, increases in IL-6 secretion from BMSCs after adherence of IM-9 cells were also partially blocked by these MoAbs. These findings suggest that multiple adhesion pathways may mediate adherence of myeloma cell lines to BMSCs, localizing tumour cells in the marrow microenvironment and triggering IL-6 secretion by BMSCs which may augment tumour cell growth.
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PMID:Cell surface expression and functional significance of adhesion molecules on human myeloma-derived cell lines. 799 88

Both spaceflight and skeletal unloading suppress the haematopoietic differentiation of macrophages (Sonnenfeld et al., Aviat. Space Environ. Med., 61:648-653, 1990; Armstrong et al., J. Appl. Physiol., 75:2734-2739, 1993). The mechanism behind this reduction in haematopoiesis has yet to be elucidated. However, changes in bone marrow extracellular matrix (ECM) may be involved. To further understand the role of ECM products in macrophage differentiation, we have performed experiments evaluating the effects of fibronectin, laminin, collagen type I, and collagen type IV on macrophage development and function. Bone marrow-derived macrophages cultured on four different ECM substrates in liquid culture medium showed less growth than those cultured on plastic. Significant morphological differences were seen on each of the substrates used. Phenotypically and functionally, as measured by class II major histocompatibility molecule (MHCII) expression, MAC-2 expression, and the secretion of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), these macrophages were similar. In contrast, bone marrow-derived macrophages cultured in suspension, using agar, showed no difference in growth when exposed to ECM proteins. However, IL-6 and TNF-alpha secretion was affected by fibronectin, laminin, collagen type I, and collagen type IV in a concentration-dependent manner. We conclude that the ECM products fibronectin, laminin, collagen type I, and collagen type IV have profound effects on macrophage development and function. Additionally, we suggest that an ECM-supplemented agar culture system provides an environment more analogous to in vivo bone marrow than does a traditional liquid culture system.
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PMID:Effects of extracellular matrix proteins on macrophage differentiation, growth, and function: comparison of liquid and agar culture systems. 801 14

Acute exposure of animals and humans to ozone results in decrements in lung function, development of airway hyperreactivity, inflammation, edema, damage to pulmonary cells, and production of several compounds with tissue damaging, fibrinogenic or fibrotic potential. The contribution of airway epithelial cells and alveolar macrophages to these processes is unclear. In this study we have directly exposed human alveolar macrophages and human airway epithelial cells to ozone in vitro and measured the cytotoxic effects of ozone, as well as the production of the inflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), and fibronectin, all of which are substantially elevated in the bronchoalveolar lavage fluid of humans exposed to ozone. Cells were grown on rigid, collagen-impregnated filter supports, and the interaction of cells with ozone facilitated by exposing them to the gas with medium below the support but no medium on top of the cells. The results show that, although macrophages are much more sensitive to ozone than epithelial cells, they do not produce increased amounts of IL-6, IL-8, or fibronectin following ozone exposure. In contrast, epithelial cells produce substantially more of all three proteins following ozone exposure, and both IL-6 and fibronectin are secreted vectorially. An immortalized human airway epithelial cell line (BEAS 2B) was used in these experiments since human airway epithelial cells are infrequently available for in vitro studies. Data from this study extend previous findings which suggest that the BEAS cell line is a useful model to study the interaction between airway epithelial cells and environmental toxicants.
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PMID:Ozone-induced release of cytokines and fibronectin by alveolar macrophages and airway epithelial cells. 802 49

Altered polymorphonuclear leukocyte (PMN) function is thought to contribute to organ dysfunction during the systemic inflammatory response syndrome (SIRS). To test this hypothesis, we evaluated whole blood PMN function adherent to fibronectin or laminin in patients with mild or severe acute pancreatitis as a paradigm for sirs. Whole-blood PMN intracellular H2O2 production, expression of CD32w (Fc gamma R II), CD16 (Fc gamma R III), and phagocytosis were performed using dichlorofluorescein diacetate, fluorescein isothiocyanate-labeled anti-CD32w, CD16, and serum-opsonized fluorescent microspheres. Group I (n x 7) represents normal control individuals; group II (n x 11) represents patients with mild acute pancreatitis. Group III (n x 15) represents critically ill patients with severe acute pancreatitis. Adherence of PMN from groups I and II to matrix proteins resulted in a 5% to 20% increase in each PMN function assayed whereas adherence of PMN from group III to matrix proteins resulted in 50% to 75% increases in each PMN function assayed. Pertussis toxin, pentoxifylline, and dibutyryl cyclic adenosine monophosphate (cAMP) each reduced group I-II H2O2 production and phagocytosis. Pentoxifylline and dibutyryl cAMP but not pertussis toxin reduced group III H2O2 production. Both intracellular H2O2 and phagocytosis assays from group III but not groups I-II showed exaggerated upregulation when exposed to NaF (4 mmol/L). Anti-interleukin-6 reduced the increase in intracellular H2O2 production in group III patients and significantly altered the exaggerated oxidative response to NaF. Longitudinal studies of group III whole-blood PMN showed persistent upregulation of intracellular H2O2 production in those patients whose hospital courses were complicated by multiple system organ failure. These results demonstrate abnormal whole blood PMN function during the systemic inflammatory response syndrome in the presence of fibronectin, or laminin and that this is mediated in part via a pertussis toxin insensitive altered guanosine triphosphate-binding protein.
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PMID:Polymorphonuclear leukocyte dysregulation during the systemic inflammatory response syndrome. 811 41

This review compares the clinical usefulness of immunological methods for the detection of structural components and metabolites of bacteria and fungi. Bacterial antigens (especially those of Mycobacterium, Neisseria, Staphylococcus aureus, Yersinia enterocolitica, Escherichia coli, Salmonella, Chlamydia, and Brucella) are best detected by enzyme-linked immunosorbent assay. Methods involving antibodies are more expensive and are effective only when performed in series. The detection of antibodies that recognize S aureus teichoic acid merely confirms the presence of a metastatic complication. Tissue invasion by Candida albicans is not yet reliably detectable by the presence of a specific antigen. Simple, but not completely reliable methods are available such as the latex test for mannans detection and/or agglutination with liposomes for detecting 48-kDa cytoplasmic protein antigen and an assay for detecting enolase antigen. A latex agglutination test has also been developed for the mannans antigen of Aspergillus and for Cryptococcus neoformans capsular polysaccharide; the latter test is more cost effective. The sensitivity of both tests is improved by serial assays. A negative finding with hemagglutination-based antibody tests rules out C albicans infection, and titers of 1/640 or higher have been associated with disseminated infection by Aspergillus. Concentrations of C albicans blastopore antigen antibodies higher than 400 IU/ml can be seen in disseminated candidiasis. High concentrations of endotoxin are indicative of imminent septic shock. Some biological indicators (C reactive protein, angiotensin converting enzyme, fibronectin, elastase-alpha 1-antitrypsin complex, tumor necrosis factor and interleukin-6) have been used to rule out a bacterial cause of fever.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunological methods for the detection of structural components and metabolites of bacteria and fungi in blood. 821 14

Previous studies show that human myeloma-derived cell lines specifically adhere to fibronectin (FN) through very late antigen-4 (VLA-4; alpha 4 beta 1 integrin complex) and RGD-peptide mechanisms, which may contribute to the localization of tumor cells in bone marrow (BM). In these studies, we characterized the adhesion of myeloma-derived cell lines to both normal and myeloma BM stromal cells (BMSCs) and the effect of adhesion on DNA synthesis. Because interleukin-6 (IL-6) plays an important role in the pathogenesis of multiple myeloma, we also examined the effects of tumor cell adhesion on IL-6 secretion by BMSCs. In 51chromium binding assays, the U266, ARH-77, and IM-9 cell lines showed 52% +/- 12%, 55% +/- 6%, and 47% +/- 7% specific adherence, respectively, to normal BMSCs and 74% +/- 4%, 60% +/- 3%, and 61% +/- 6% specific adherence, respectively, to myeloma BMSCs. In contrast, only 12% to 13% specific binding of HS-Sultan cells to BMSCs was noted. The binding of myeloma cells to BMSCs was partially blocked with anti-beta 1 monoclonal antibody (MoAb), anti-beta 2 integrin MoAb, and excess RGD peptide, suggesting multiple mechanisms for the adhesion of myeloma cell lines to BMSCs. Binding of cell lines to FN or myeloma BMSCs did not affect cell line proliferation; however, adhesion of myeloma cell lines to normal BMSCs decreased DNA synthesis, ie, stimulation indices are 0.1 +/- 0.04, 0.2 +/- 0.1, 0.2 +/- 0.07, and 0.1 +/- 0.06 for the adherent non-IL-6-dependent U266, ARH-77, HS-Sultan, and IM-9 cells, respectively (n = 5, P < .01). In contrast, adherence of IL-6-dependent B9 cells increased their proliferation (stimulation index, 3.2 +/- 0.7). Significant (twofold to eightfold) increases in IL-6 secretion were evident in cell line-adherent (> or = 12 hours) normal and myeloma BMSC cultures. Paraformaldehyde fixation of BMSCs before adhesion completely abrogated IL-6 secretion, suggesting that IL-6 secretion was triggered in BMSCs rather than in cell lines. Partial blocking of cell line adhesion to BMSCs, using anti-beta 1 integrin and anti-beta 2 integrin MoAbs and RGD peptide, also partially blocked the triggering of IL-6 secretion by BMSCs. When cell lines were placed in Transwell inserts and then cultured with either normal or myeloma BMSCs, permitting juxtaposition without cell to cell contact between myeloma cell lines and BMSCs, no increase in IL-6 secretion was observed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Adhesion of human myeloma-derived cell lines to bone marrow stromal cells stimulates interleukin-6 secretion. 826 Jul 8


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