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)

We previously showed that sphingosine 1-phosphate (SPP) acts as a second messenger for tumor necrosis factor alpha-induced interleukin-6 (IL-6) synthesis in osteoblast-like MC3T3-E1 cells. In the present study, we further investigated the mechanism of IL-6 synthesis induced by SPP in MC3T3-E1 cells. SPP significantly induced p42/p44 mitogen-activated protein (MAP) kinase activity. PD98059, an inhibitor of MAP kinase kinase, suppressed SPP-induced IL-6 synthesis as well as SPP-induced MAP kinase activation. The patterns of both inhibitions were similar. TMB-8, an inhibitor of Ca2+ mobilization from intracellular Ca2+ stores, significantly suppressed the SPP-induced IL-6 synthesis. These results strongly suggest that SPP-induced IL-6 synthesis is mediated via p42/p44 MAP kinase activation in osteoblast-like cells and that the SPP-induced IL-6 synthesis is dependent on intracellular Ca2+ mobilization.
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PMID:Activation of mitogen-activated protein kinase is involved in sphingosine 1-phosphate-stimulated interleukin-6 synthesis in osteoblasts. 941 15

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic cytokine that elicits a large number of biological effects. However, the intracellular signaling mechanisms that are responsible for the TNF-alpha effects remain largely unknown. We have previously demonstrated that cultured mouse Sertoli cells, after TNF-alpha treatment, increase the surface expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and interleukin-6 (IL-6) production (Riccioli, A., Filippini, A., De Cesaris, P., Barbacci, E., Stefanini, M., Starace, G., and Ziparo, E. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 5808-5812). Here, we show that, in cultured Sertoli cells, TNF-alpha activates the mitogen-activated protein kinase pathway (p38, c-Jun N-terminal protein kinase/stress-activated protein kinase, and the p42/p44 mitogen-activated protein kinases) as revealed by an increased phosphorylation of p38, activating transcription factor-2, c-Jun, and Elk-1. Furthermore, our data indicate that the biological effects induced by TNF-alpha in Sertoli cells (enhancement of ICAM-1, VCAM-1, and IL-6 expression) depend on the activation of different signaling pathways. SB203580, a highly specific p38 inhibitor, does not affect ICAM-1 and VCAM-1 expression, but strongly inhibits IL-6 production. Moreover, interferon-gamma, which up-regulates adhesion molecule expression and reduces IL-6 production, does not induce phosphorylation of p38. Our data strongly support the hypothesis that, in response to TNF-alpha, activation of p38 leads to IL-6 production, whereas ICAM-1 and VCAM-1 expression could be induced by activation of the c-Jun N-terminal protein kinase/stress-activated protein kinase pathway.
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PMID:Tumor necrosis factor-alpha induces interleukin-6 production and integrin ligand expression by distinct transduction pathways. 951 59

The biliary epithelium is exposed to mediators of inflammation such as bacterial endotoxin or lipopolysaccharide (LPS) in a variety of inflammatory conditions. These conditions are also characterized by cholangiocyte proliferation and a predisposition to malignancy. Furthermore, LPS can enhance the expression of interleukin-6 (IL-6), a known biliary mitogen. However, the effects of LPS on cholangiocyte proliferation or IL-6 secretion are unknown. Thus, our aims were to determine if LPS stimulates cholangiocyte proliferation by IL-6-dependent signaling pathways. H69 cells derived from normal human intrahepatic cholangiocytes proliferated in response to LPS. Cholangiocytes responded to LPS (and other inflammatory cytokines such as tumor necrosis factor alpha [TNF-alpha] and IL-1beta) by increased secretion of IL-6, which had a mitogenic effect on H69 cells. Preincubation with anti-IL-6 neutralizing antibodies inhibited LPS-induced proliferation. Furthermore, cholangiocytes possessed the IL-6 receptor complex subunits and intact signaling mechanisms leading to activation of signal transducers and activators of transcription (STAT) factors. Although both p38 and p44/p42 mitogen-activated protein kinases (MAPKs) were constitutively present and active in cholangiocytes, IL-6 increased p44/p42, but not p38 MAPK activity. PD098059 inhibited activation of p44/p42 MAPK in cholangiocytes and completely blocked DNA synthesis in response to IL-6 or LPS. These studies identify a critical role for the p44/p42 MAPK in cholangiocyte proliferation and demonstrate that the proliferative response of cholangiocytes to inflammatory mediators such as LPS involves IL-6-mediated activation of the p44/p42 MAPK pathway.
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PMID:Lipopolysaccharide induces cholangiocyte proliferation via an interleukin-6-mediated activation of p44/p42 mitogen-activated protein kinase. 1009 43

We previously reported that endothelin-1 induces synthesis of interleukin-6 (IL-6) via activation of protein kinase C in osteoblast-like MC3T3-E1 cells. In the present study, we further investigated whether p42/p44 mitogen-activated protein (MAP) kinase is involved in endothelin-1-induced IL-6 synthesis in these cells. Endothelin-1 stimulated p42/p44 MAP kinase activation in a dose-dependent manner in the range between 0.1 nmol/L and 0.1 micromol/L. PD98059, a specific inhibitor of the upstream kinase that activates p42/p44 MAP kinase, suppressed endothelin-1-induced IL-6 synthesis as well as endothelin-1-activated p42/p44 MAP kinase. Both p42/p44 MAP kinase activation and IL-6 synthesis induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C-activating phorbol ester, were reduced by PD98059. Calphostin C, a highly specific inhibitor of protein kinase C, suppressed endothelin-1-stimulated p42/p44 MAP kinase activation as well as endothelin-1-induced IL-6 synthesis. These results strongly suggest that protein kinase C-dependent p42/p44 MAP kinase activation is involved in endothelin-1-induced IL-6 synthesis in osteoblast-like cells.
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PMID:Involvement of p42/p44 MAP kinase in endothelin-1-induced interleukin-6 synthesis in osteoblast-like cells. 1022 43

Prostaglandin F2alpha (PGF2alpha) significantly induced p42/p44 mitogen-activated protein (MAP) kinase activity in osteoblast-like MC3T3-E1 cells. PD98059, a selective inhibitor of MAP kinase kinase, inhibited PGF2alpha-induced interleukin-6 (IL-6) synthesis as well as PGF2alpha-induced p42/p44 MAP kinase activation. PD98059 suppressed the IL-6 synthesis induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a protein kinase C (PKC) activator, or NaF, an activator of heterotrimeric GTP-binding protein, as well as the p42/p44 MAP kinase activation by TPA or NaF. Calphostin C, a highly potent and specific inhibitor of PKC, inhibited the PGF2alpha-induced p42/p44 MAP kinase activity. These results strongly suggest that PKC-dependent p42/p44 MAP kinase activatioin is involved in PGF2alpha-induced IL-6 synthesis in osteoblasts.
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PMID:p42/p44 mitogen-activated protein kinase activation is involved in prostaglandin F2alpha-induced interleukin-6 synthesis in osteoblasts. 1037 4

We previously showed that sphingosine 1-phosphate acts as a second messenger for tumor necrosis factor alpha-induced interleukin-6 synthesis in osteoblast-like MC3T3-E1 cells and that the synthesis by sphingosine 1-phosphate is dependent on p42/p44 mitogen-activated protein (MAP) kinase activation. In the present study, we investigated the effect of sphingosine 1-phosphate on the induction of heat shock protein 27 (HSP27) in MC3T3-E1 cells. Not C2-ceramide, but sphingosine and sphingosine 1-phosphate significantly induced HSP27 accumulation dose dependently in the range between 1microM and 30 microM. DL-threo-dihydrosphingosine, an inhibitor of sphingosine kinase, markedly inhibited the sphingosine-induced HSP27 accumulation. Sphingosine 1-phosphate induced increase in the levels of the mRNA for HSP27. Sphingosine 1-phosphate stimulated the phosphorylation of p38 MAP kinase. The sphingosine 1-phosphate-induced HSP27 accumulation was dose dependently suppressed by SB203580, an inhibitor of p38 MAP kinase, but not PD98059, an inhibitor of the upstream kinase that activates p42/p44 MAP kinase. SB203580 reduced the sphingosine 1-phosphate-induced increase of mRNA for HSP27. These results strongly suggest that sphingosine 1-phosphate-stimulated HSP27 induction is mediated via p38 MAP kinase activation in osteoblasts.
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PMID:Sphingosine 1-phosphate induces heat shock protein 27 via p38 mitogen-activated protein kinase activation in osteoblasts. 1049 Dec 24

Tumor necrosis factor alpha (TNF-alpha) is a cytokine implicated in the pathogenesis of numerous chronic and acute inflammatory conditions. We have previously shown that mouse Sertoli cells respond to TNF-alpha by increasing interleukin-6 production and intercellular adhesion molecule-1 (ICAM-1) expression (1). In this cell type TNF-alpha activates the mitogen-activated protein kinase (MAPK) pathways p42/p44 MAPK, JNK/SAPK, and p38, the last of which is responsible for interleukin-6 production (1). To determine which MAPK signaling pathway is required for TNF-alpha induction of ICAM-1 expression, we have utilized the protein kinase inhibitor dimethylaminopurine, demonstrating that treatment of Sertoli cells with such compound significantly reduced ICAM-1 expression and JNK/SAPK activation. Moreover, dimethylaminopurine treatment increased the expression of MAPK phosphatase-2, providing a possible mechanism of action of this compound. By using agonist antibodies to p55 and to p75 TNF-alpha receptors and both human and mouse TNF-alpha, we demonstrate that both TNF receptors are expressed and that only the p55 receptor is involved in ICAM-1 expression. The p55 receptor activates all of the three pathways, whereas p75 failed to activate any of the MAPKs. Altogether our results demonstrate that TNF-alpha up-regulates ICAM-1 expression through the activation of the JNK/SAPK transduction pathway mediated by the p55 receptor.
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PMID:Activation of Jun N-terminal kinase/stress-activated protein kinase pathway by tumor necrosis factor alpha leads to intercellular adhesion molecule-1 expression. 1050 45

Interleukin-6 (IL-6) is involved in the pathophysiology of various diseases of the CNS. Because the molecular mechanism of action of this cytokine in human neurons is not well understood, we were interested in characterizing and defining a model system for IL-6-induced activation of signal transduction cascades, transcriptional activation, and protein synthesis in human neuronal cells. We show that IL-6 leads to transcriptional activation of signal transducer and activator of transcription 3 (STAT3) in human SH-SY5Y neuroblastoma cells. IL-6-induced activation and translocation of STAT3 and to a lesser degree STAT1 but not STAT5 are demonstrated. STAT3 is phosphorylated on Tyr705 and Ser727 residues on stimulation with IL-6, suggesting maximal activation of transcription. We also show IL-6-induced phosphorylation of p42/44 mitogen-activated protein (MAP) kinase, providing evidence for MAP kinase pathway activation. The physiological relevance of our results is confirmed by IL-6-induced phosphorylation of key signaling proteins of both STAT and MAP kinase pathway in rat primary hippocampal neurons. Furthermore, de novo protein synthesis on IL-6 activation is demonstrated.
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PMID:Interleukin-6 activates signal transducer and activator of transcription and mitogen-activated protein kinase signal transduction pathways and induces de novo protein synthesis in human neuronal cells. 1053 60

We previously reported that endothelin-1 (ET-1) activates p42/p44 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells and consequently induces synthesis of interleukin-6. In the present study, we investigated the effect of ET-1 on the induction of heat shock protein 27 (HSP 27) in MC3T3-E1 cells. ET-1 time and dose dependently stimulated HSP 27 accumulation. ET-1 induced an increase in the levels of mRNA for HSP 27. Both staurosporine and calphostin C, inhibitors of protein kinase C (PKC), suppressed the ET-1-induced HSP 27 accumulation. 12-O-tetradecanoylphorbol 13-acetate (TPA), a PKC activator, induced the HSP 27 accumulation and the expression of mRNA for HSP 27. The ET-1-stimulated HSP 27 accumulation was reduced in PKC-downregulated MC3T3-E1 cells. The HSP 27 accumulation by ET-1 was not suppressed by PD-98059, an inhibitor of the upstream kinase that activates p42/p44 MAP kinase. ET-1 or TPA induced the phosphorylation of p38 MAP kinase. SB-203580, an inhibitor of p38 MAP kinase, reduced the ET-1-stimulated HSP 27 accumulation. Calphostin C and U-73122, a phospholipase C inhibitor, suppressed the ET-1-induced phosphorylation of p38 MAP kinase. U-73122 and propranolol, a phosphatidic acid phosphohydrolase inhibitor, reduced the ET-1-stimulated HSP 27 accumulation. SB-203580 suppressed the ET-1-stimulated increase in the mRNA levels for HSP 27. These results strongly suggest that ET-1 stimulates HSP 27 induction in osteoblasts and that p38 MAP kinase activation is involved in the HSP 27 induction.
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PMID:Endothelin-1 stimulates heat shock protein 27 induction in osteoblasts: involvement of p38 MAP kinase. 1060 Jul 94

Cardiotrophin-1 (CT-1) originally was discovered as a factor that can induce hypertrophy of cardiac myocytes, both in vitro and in vivo. Subsequently, CT-1 has been shown to have a wide variety of different effects on cardiac and noncardiac, cells including the ability to stimulate the survival of both cardiac and neuronal cells. Like other members of the interleukin-6 family of cytokines, CT-1 stimulates both the p42/p44 mitogen-activated protein kinase pathway and the Janus-activated kinase/signal transducers and activators of transcription pathway. Interestingly, whilst activation of the p42/p44 mitogen-activated protein kinase pathway is necessary for the survival-promoting effects of CT-1 in cardiac cells, it is not required for its hypertrophic effect, which is likely to involve activation of the Janus-activated kinase/signal transducer and activator of transcription-3 pathway. CT-1, therefore, may be of use as a novel cardioprotective agent, particularly if its hypertrophic effect can be specifically inhibited.
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PMID:Cardiotrophin-1: a novel cytokine and its effects in the heart and other tissues. 1067 12


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