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Wise GE, Que BG, Huang H. Synthesis and secretion of MCP-1 by dental follicle cells--implications for tooth eruption. J Dent Res 1999; 78:1677-81. [PMID: 10576162 DOI: 10.1177/00220345990780110301] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The monocyte chemotactic protein-1 (MCP-1) gene is expressed in the dental follicle, a loose connective tissue sac that must be present for eruption to occur. The role of MCP-1 may be to recruit mononuclear cells (monocytes) to the dental follicle, where these cells, in turn, fuse to form osteoclasts to resorb alveolar bone for the formation of an eruption pathway. Thus, it was the aim of this study to determine if MCP-1 is secreted by dental follicle cells in culture and if its secretion is enhanced by potential tooth eruption molecules. Western blotting and a two-site capture enzyme-linked immunoabsorbent assay demonstrated that MCP-1 was synthesized and secreted into the medium by the follicle cells. Incubation of the cells with either transforming growth factor-beta one (TGF-beta 1) or interleukin-one alpha (IL-1 alpha) enhanced the secretion of MCP-1 by the cells. Measurement of the chemotactic ability of the conditioned medium to attract mouse monocytes demonstrated that the chemotaxis of the medium was increased if the cells had previously been incubated in IL-1 alpha, although there appears to be a threshold concentration of MCP-1 above which chemotaxis is not enhanced. These combined results suggest that the critical initial cellular event of tooth eruption, an influx of mononuclear cells into the dental follicle at an early post-natal age, may be initiated by the secretion of MCP-1 by the dental follicle cells.
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Affiliation(s)
- G E Wise
- Department of Veterinary Anatomy and Cell Biology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803-8408, USA
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52
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Merril AH, Nikolova-Karakashian M, Schmelz EM, Morgan ET, Stewart J. Regulation of cytochrome P450 expression by sphingolipids. Chem Phys Lipids 1999; 102:131-9. [PMID: 11001567 DOI: 10.1016/s0009-3084(99)00081-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Sphingolipids modulate many aspects of cell function, including the expression of cytochrome P450, a superfamily of heme proteins that participate in the oxidation of a wide range of compounds of both endogenous (steroid hormones and other lipids) and exogenous (e.g. alcohol, drugs and environmental pollutants) origin. Cytochrome P450-2C11 (CYP 2C11) is down-regulated in response to interleukin-1beta (IL-1beta), and this response involves the hydrolysis of sphingomyelin to ceramide as well as ceramide to sphingosine, and phosphorylation of sphingosine to sphingosine 1-phosphate. Activation of ceramidase(s) are a key determinant of which bioactive sphingolipid metabolites are formed in response to IL-1beta. Ceramidase activation also appears to account for the loss of expression of CYP 2C11 when hepatocytes are placed in cell culture, and the restoration of expression when they are plated on Matrigel; hence, this pathway is influenced by, and may mediate, interactions between hepatocytes and the extracellular matrix. Recent studies using inhibitors of sphingolipid metabolism have discovered that sphingolipids are also required for the induction of CYP1A1 by 3-methylcholanthrene, however, in this case, the requirement is for de novo sphingolipid biosynthesis rather than the turnover of complex sphingolipids. These findings illustrate how changes in sphingolipid metabolism can influence the regulation of at least several isoforms of cytochrome P450.
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Affiliation(s)
- A H Merril
- Department of Biochemistry, Rollins Research Center, Emory University School of Medicine, Atlanta, GA 30322-3050, USA.
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53
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Hammond EA, Smart D, Toulmond S, Suman-Chauhan N, Hughes J, Hall MD. The interleukin-1 type I receptor is expressed in human hypothalamus. Brain 1999; 122 ( Pt 9):1697-707. [PMID: 10468509 DOI: 10.1093/brain/122.9.1697] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Several lines of evidence suggest that interleukin-1 (IL-1) acts directly on the central nervous system, probably within the hypothalamus, causing effects such as fever, activation of the immune response and sickness behaviour. IL-1 has also been shown to be involved in the aetiology of several neuronal diseases, including neurodegeneration, stroke and Alzheimer's disease. However, the question as to whether the full-length type I IL-1 receptor (IL-1RI) is expressed in the human hypothalamus has yet to be addressed. Using the polymerase chain reaction, we cloned a full-length cDNA encoding the human hypothalamic IL-1RI from human hypothalamic cDNA. The DNA sequence of the human hypothalamic receptor was identical to that of the human fibroblast IL-1RI. The IL-1RI receptor protein was detected in astrocytes of normal human hypothalamic brain sections using immunocytochemical techniques. To ascertain that the cloned receptor was functional, Chinese hamster ovary (CHO) cells were transfected with a plasmid vector containing the IL-1RI coding region. IL-1RI-mediated-signal transduction was assessed by microphysiometry and activation of p38 MAP (mitogen-activated protein) kinase. We report the first demonstration that both the type I IL-1 transcript and the protein are expressed in the human hypothalamus. The receptor was expressed in a stable CHO cell line, providing a tool with which to embark on a thorough analysis of the signalling mechanisms mediated by IL-1 via this receptor.
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Affiliation(s)
- E A Hammond
- Parke-Davis Neuroscience Research Centre, Cambridge University and School of Biological Sciences, Manchester, UK.
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Coogan AN, O'Neill LA, O'Connor JJ. The P38 mitogen-activated protein kinase inhibitor SB203580 antagonizes the inhibitory effects of interleukin-1beta on long-term potentiation in the rat dentate gyrus in vitro. Neuroscience 1999; 93:57-69. [PMID: 10430470 DOI: 10.1016/s0306-4522(99)00100-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Levels of the pro-inflammatory cytokine interleukin-1beta are known to be elevated in patients with chronic disorders such as Alzheimer's disease. We have investigated the effects of interleukin-1beta on long-term potentiation and N-methyl-D-aspartate receptor-mediated field potentials in the rat dentate gyrus in vitro utilizing field extracellular recordings obtained from the middle third of the molecular layer of the dentate gyrus. Presynaptic stimulation was applied to the commissural/association pathway at a frequency of 0.05 Hz and at a distance of 50 microm from the granule cell body layer. As previously reported, interleukin-1beta (1 ng/ml) caused an inhibition of long-term potentiation (108+/-2% of baseline 1 h following application of tetanic stimulation compared with 145+/-5% in vehicle control slices). This action of interleukin-1beta on long-term potentiation, as well as an inhibition of N-methyl-D aspartate receptor-mediated field potentials, was attenuated by pre-treatment of slices with the p38 mitogen-associated protein kinase inhibitor SB203580 (1 microM). SB203580 alone had no significant affect on long-term potentiation, but did cause an increase in baseline synaptic transmission [107+/-2% of baseline, 1 h after SB203580 (1 microM) treatment]. The p42/44 mitogen-activated protein kinase cascade inhibitor PD98059 (50 microM) did not inhibit the interleukin-1beta-induced inhibition of N-methyl-D-aspartate receptor-mediated field potentials. The cyclooxygenase inhibitor indomethacin (50 microM) was found to attenuate the interleukin-1beta-induced effects on both long-term potentiation and N-methyl-D-aspartate receptor-mediated field potentials. The lipid second messenger analogue C2 ceramide (20 microM) was found to attenuate the expression of long-term potentiation (108+/-3% of baseline 1 h following tetanic stimulation), and this effect was not blocked by pre-treatment with SB203580. To investigate a possible role for interleukin-1beta in the normal expression of long-term potentiation, the interleukin-1 receptor antagonist (25 ng/ml) was applied during the maintenance phase of long-term potentiation. This was found to depress the sustained expression of long-term potentiation (116+/-6% of baseline 1 h following tetanic stimulation). Our results indicate possible signalling mechanisms by which interleukin-1beta at pathophysiological concentrations may serve to inhibit long-term potentiation, and also suggests a role for IL-1beta in the physiological expression of synaptic plasticity in the rat dentate gyrus in vitro.
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Affiliation(s)
- A N Coogan
- Department of Human Anatomy and Physiology, University College, Dublin, Ireland
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55
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Belt AR, Baldassare JJ, Molnár M, Romero R, Hertelendy F. The nuclear transcription factor NF-kappaB mediates interleukin-1beta-induced expression of cyclooxygenase-2 in human myometrial cells. Am J Obstet Gynecol 1999; 181:359-66. [PMID: 10454683 DOI: 10.1016/s0002-9378(99)70562-4] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Up-regulation of prostaglandin production by gestational tissues in the setting of intrauterine infection has been implicated as an important contributor to preterm labor and parturition. In this study we investigated the possible role of the nuclear transcription factor NF-kappaB in interleukin-1 signaling, leading to the expression of cyclooxygenase 2 and prostaglandin production in human myometrial cell cultures. STUDY DESIGN Human myometrial smooth muscle cells from an immortalized line were used as a model system between passages 20 and 35. Growth-arrested cell cultures were stimulated with human recombinant interleukin 1, and the activation of NF-kappaB was assessed by the degradation of the inhibitory protein IkappaB-alpha (Western analysis), as well as by nuclear binding of NF-kappaB by using an electrophoretic mobility shift assay. The abundance of cyclooxygenase-2 messenger ribonucleic acid and protein was measured by Northern and Western analyses, whereas prostaglandin (prostaglandin I(2 ) and prostaglandin E(2 )) production was determined by specific radioimmunoassays. RESULTS Within 15 minutes of stimulation with interleukin 1, 90% of IkappaB-alpha was degraded. This was temporally associated with nuclear translocation and binding of NF-kappaB. Within 30 minutes, cyclooxygenase 2 messenger ribonucleic acid appeared, with steady-state levels increasing up to 4 hours. This was followed by an up to 80-fold increase in cyclooxygenase 2 protein and a corresponding time-dependent increase in prostaglandin production. When IkappaB-alpha degradation was blocked with calpain I inhibitor, NF-kappaB translocation, cyclooxygenase 2 messenger ribonucleic acid and protein expression, and prostaglandin synthesis were also inhibited. CONCLUSION Stimulation of human myometrial cells with interleukin 1 leads to rapid activation of the transcription factor NF-kappaB, which is functionally linked to the expression of cyclooxygenase 2 messenger ribonucleic acid, protein, and prostaglandin synthesis.
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Affiliation(s)
- A R Belt
- Department of Pharmacological Science, St. Louis University, Missouri, USA
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56
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Li X, Commane M, Burns C, Vithalani K, Cao Z, Stark GR. Mutant cells that do not respond to interleukin-1 (IL-1) reveal a novel role for IL-1 receptor-associated kinase. Mol Cell Biol 1999; 19:4643-52. [PMID: 10373513 PMCID: PMC84262 DOI: 10.1128/mcb.19.7.4643] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutagenized human 293 cells containing an interleukin-1 (IL-1)-regulated herpes thymidine kinase gene, selected in IL-1 and gancyclovir, have yielded many independent clones that are unresponsive to IL-1. The four clones analyzed here carry recessive mutations and represent three complementation groups. Mutant A in complementation group I1 lacks IL-1 receptor-associated kinase (IRAK), while the mutants in the other two groups are defective in unknown components that function upstream of IRAK. Expression of exogenous IRAK in I1A cells (I1A-IRAK) restores their responsiveness to IL-1. Neither NFkappaB nor Jun kinase is activated in IL-1-treated I1A cells, but these responses are restored in I1A-IRAK cells, indicating that IRAK is required for both. To address the role of the kinase activity of IRAK in IL-1 signaling, its ATP binding site was mutated (K239A), completely abolishing kinase activity. In transfected I1A cells, IRAK-K239A was still phosphorylated upon IL-1 stimulation and, surprisingly, still complemented all the defects in the mutant cells. Therefore, IRAK must be phosphorylated by a different kinase, and phospho-IRAK must play a role in IL-1-mediated signaling that does not require its kinase activity.
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Affiliation(s)
- X Li
- Department of Molecular Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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57
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Sizemore N, Leung S, Stark GR. Activation of phosphatidylinositol 3-kinase in response to interleukin-1 leads to phosphorylation and activation of the NF-kappaB p65/RelA subunit. Mol Cell Biol 1999; 19:4798-805. [PMID: 10373529 PMCID: PMC84278 DOI: 10.1128/mcb.19.7.4798] [Citation(s) in RCA: 536] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The work of Reddy et al. (S. A. Reddy, J. A. Huang, and W. S. Liao, J. Biol. Chem. 272:29167-29173, 1997) reveals that phosphatidylinositol 3-kinase (PI3K) plays a role in transducing a signal from the occupied interleukin-1 (IL-1) receptor to nuclear factor kappaB (NF-kappaB), but the underlying mechanism remains to be determined. We have found that IL-1 stimulates interaction of the IL-1 receptor accessory protein with the p85 regulatory subunit of PI3K, leading to the activation of the p110 catalytic subunit. Specific PI3K inhibitors strongly inhibit both PI3K activation and NF-kappaB-dependent gene expression but have no effect on the IL-1-stimulated degradation of IkappaBalpha, the nuclear translocation of NF-kappaB, or the ability of NF-kappaB to bind to DNA. In contrast, PI3K inhibitors block the IL-1-stimulated phosphorylation of NF-kappaB itself, especially the p65/RelA subunit. Furthermore, by using a fusion protein containing the p65/RelA transactivation domain, we found that overexpression of the p110 catalytic subunit of PI3K induces p65/RelA-mediated transactivation and that the specific PI3K inhibitor LY294,002 represses this process. Additionally, the expression of a constitutively activated form of either p110 or the PI3K-activated protein kinase Akt also induces p65/RelA-mediated transactivation. Therefore, IL-1 stimulates the PI3K-dependent phosphorylation and transactivation of NF-kappaB, a process quite distinct from the liberation of NF-kappaB from its cytoplasmic inhibitor IkappaB.
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Affiliation(s)
- N Sizemore
- Department of Molecular Biology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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58
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Kaibori M, Sakitani K, Oda M, Kamiyama Y, Masu Y, Nishizawa M, Ito S, Okumura T. Immunosuppressant FK506 inhibits inducible nitric oxide synthase gene expression at a step of NF-kappaB activation in rat hepatocytes. J Hepatol 1999; 30:1138-45. [PMID: 10406194 DOI: 10.1016/s0168-8278(99)80270-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND/AIMS Recent evidence indicates that an increase in nitric oxide production after liver transplantation is associated with acute allograft rejection. Nitric oxide mediates cellular injury under various pathological conditions in the liver. Studies were performed to determine whether the immunosuppressants FK506 and cyclosporin A directly influence gene expression of inducible nitric oxide synthase by interleukin 1beta in hepatocytes. METHODS Primary cultures of rat hepatocytes were treated with interleukin 1beta in the presence and absence of FK506 or cyclosporin A. Release of nitrite (nitric oxide metabolite) into culture medium, levels of inducible nitric oxide synthase protein and mRNA, and activation of nuclear factor-kappaB were compared with the two drugs. RESULTS Interleukin 1beta increased levels of inducible nitric oxide synthase protein and inducible nitric oxide synthase mRNA, as well as nitric oxide production, in the cultured hepatocytes. Nuclear factor-kappaB, an important transcription factor in inducible nitric oxide synthase gene expression in response to inflammation, also appeared in the nuclear fraction of hepatocytes after addition of interleukin 1beta. FK506 markedly inhibited the nitric oxide formation, inducible nitric oxide synthase protein synthesis and inducible nitric oxide synthase mRNA expression induced by interleukin 1beta, but cyclosporin A had no effects. Furthermore, FK506 inhibited nuclear factor-kappaB activation and decreased mRNA levels of the p50/p65 subunits of nuclear factor-kappaB. CONCLUSIONS These results demonstrate that FK506, but not cyclosporin A, inhibits the induction of inducible nitric oxide synthase expression during nuclear factor-kappaB activation. FK506 may influence liver function during diseases by modulating the nitric oxide pathway, in addition to its immunosuppressive effect.
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Affiliation(s)
- M Kaibori
- First Department of Surgery, Kansai Medical University, Moriguchi, Osaka, Japan
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59
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Tsuji F, Oki K, Senda T, Horiuchi M, Mita S. Effects of mitogen-activated protein kinase inhibitors or phosphodiesterase inhibitors on interleukin-1-induced cytokines production in synovium-derived cells. Immunol Lett 1999; 68:275-9. [PMID: 10424432 DOI: 10.1016/s0165-2478(99)00051-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of mitogen-activated protein (MAP) kinase inhibitors or phosphodiesterase (PDE) inhibitors on interleukin (IL)-1-induced cytokines production in synovium-derived cells were investigated. Human synoviocyte (HS) or synovial sarcoma (SW982) stimulated by IL-1beta (100 ng/ml) produced various cytokines including IL-6, IL-8, GROalpha, VEGF, basic FGF and tumor necrosis factor alpha (TNFalpha) in vitro. SB202190 or SB203580, an inhibitor of p38 MAP kinase, inhibited all cytokines production in both cells. PD98059, an inhibitor of MAP kinase kinase (MEK), inhibited IL-6, IL-8 and basic FGF production in HS and all cytokines production except basic FGF in SW982. However, many of its effects were weaker than those of SB202190 or SB203580. Quazinone, an inhibitor of cyclic GMP-inhibited PDE, scarcely affected cytokines production in both cells. Rolipram or R0201724, an inhibitor of cyclic AMP-specific PDE, inhibited IL-8 and basic FGF production in HS and TNFalpha production in SW982, however, it enhanced the other cytokines production in SW982. These results suggest that the activation of MAP kinase cascade may be important for IL-1-induced cytokines production in synovium-derived cells. On the other hand, the role of cyclic AMP may be dependent on cell and cytokine types.
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Affiliation(s)
- F Tsuji
- Discovery Research Division, Santen Pharmaceutical, Osaka, Japan
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60
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Staats HF, Ennis FA. IL-1 Is an Effective Adjuvant for Mucosal and Systemic Immune Responses When Coadministered with Protein Immunogens. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.10.6141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Mucosal immunization with soluble protein Ag alone may induce Ag-specific tolerance, whereas mucosal immunization with Ag in the presence of a mucosal adjuvant may induce Ag-specific systemic and mucosal humoral and cell-mediated immune responses. The most widely used and studied mucosal adjuvant is cholera toxin (CT). Although the mechanism of adjuvanticity of CT is not completely understood, it is known that CT induces mucosal epithelial cells to produce the proinflammatory cytokines IL-1, IL-6, and IL-8 and up-regulates macrophage production of IL-1 and the costimulatory molecule B7.2. Because IL-1 may duplicate many of the activities of CT, we evaluated IL-1α and IL-1β for their ability to serve as mucosal adjuvants when intranasally administered with soluble protein Ags. IL-1α and IL-1β were as effective as CT for the induction of Ag-specific serum IgG, vaginal IgG and IgA, systemic delayed-type hypersensitivity, and lymphocyte proliferative responses when intranasally administered with soluble protein Ag. Our results indicate that IL-1α and IL-1β may be useful as mucosal vaccine adjuvants. Such an adjuvant may be useful, and possibly required, for vaccine-mediated protection against pathogens that infect via the mucosal surfaces of the host such as HIV.
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Affiliation(s)
- Herman F. Staats
- Departments of Medicine and Immunology, Center for AIDS Research, Duke University Medical Center, Durham, NC 27710
| | - Francis A. Ennis
- Departments of Medicine and Immunology, Center for AIDS Research, Duke University Medical Center, Durham, NC 27710
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Kolomytkin OV, Marino AA, Sadasivan KK, Wolf RE, Albright JA. Intracellular signaling mechanisms of interleukin-1beta in synovial fibroblasts. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:C9-C15. [PMID: 9886915 DOI: 10.1152/ajpcell.1999.276.1.c9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The possibility that membrane depolarization of synovial fibroblasts caused by interleukin-1beta (IL-1beta) was mediated by protein kinase C (PKC) and Ca2+ influx was studied using inhibitor and activator analysis. The effect of IL-1beta was blocked by bisindolylmaleimide I, an inhibitor of PKC, and by the Ca2+ channel blockers nifedipine and verapamil. In other experiments, PKC was activated using phorbol 12-myristate 13-acetate, and Ca2+ influx was increased by means of a Ca2+ ionophore. Simultaneous application of phorbol ester and Ca2+ ionophore in the absence of IL-1beta mimicked the depolarization caused by IL-1beta. The results were consistent with the hypothesis that, under the conditions studied, activation of PKC and Ca2+ influx are necessary and sufficient processes in the transduction of IL-1beta by synovial cells leading to membrane depolarization. The essential role of protein phosphorylation and Ca2+ influx in the early electrophysiological response of synovial fibroblasts to IL-1beta was therefore established. The role of IL-1beta-induced depolarization in regulating protein expression by the cells remains to be determined, but the results reported here, taken together with observations that protein phosphorylation and Ca2+ influx also mediate the effect of IL-1beta on protease production (1, 2), suggest that electrophysiological changes are actually part of the pathway for expression of proteases in response to IL-1beta.
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Affiliation(s)
- O V Kolomytkin
- Department of Orthopaedic Surgery, Department of Medicine, Louisiana State University Medical Center, Shreveport, Louisiana 71130-3932, USA
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62
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Miyazawa K, Mori A, Miyata H, Akahane M, Ajisawa Y, Okudaira H. Regulation of interleukin-1beta-induced interleukin-6 gene expression in human fibroblast-like synoviocytes by p38 mitogen-activated protein kinase. J Biol Chem 1998; 273:24832-8. [PMID: 9733787 DOI: 10.1074/jbc.273.38.24832] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Involvement of p38 mitogen-activated protein (MAP) kinase in interleukin (IL)-6 gene expression of human fibroblast-like synoviocytes (FLSs) was assessed. p38 MAP kinase was constitutively expressed in human FLSs and activated in response to IL-1beta. A pyridinylimidazole compound, SB203580, inhibited p38 MAP kinase activity in vivo, since the activity of MAPKAP kinase-2 (a substrate of p38 MAP kinase) in IL-1beta-stimulated FLSs was totally suppressed by it. SB203580 concentration-dependently inhibited protein production and gene expression of IL-6 by human FLSs. The effect of SB203580 was dependent on de novo protein synthesis. SB203580 significantly reduced the stability of IL-6 mRNA without affecting the rate of IL-6 gene transcription. Here, we provide evidence that p38 MAP kinase is activated in response to IL-1beta in human FLSs and is involved in IL-6 synthesis by stabilizing IL-6 mRNA.
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Affiliation(s)
- K Miyazawa
- Central Research Laboratories, Kissei Pharmaceutical Co., Ltd., Nagano-Pref. 399-8304, Japan.
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63
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Pfeilschifter J, Huwiler A. Identification of ceramide targets in interleukin-1 and tumor necrosis factor-alpha signaling in mesangial cells. KIDNEY INTERNATIONAL. SUPPLEMENT 1998; 67:S34-9. [PMID: 9736250 DOI: 10.1046/j.1523-1755.1998.06707.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An increasing number of cell-surface receptors have been shown to trigger sphingomyelin turnover and generation of the lipid signaling molecule ceramide. Ceramide plays a role in mediating cellular responses as diverse as inflammation, differentiation, gene expression, growth suppression, and apoptosis. A radioiodinated, photoaffinity-labeling analog of ceramide ([125I]TID-ceramide) was used to identify downstream signaling targets of ceramide. Ceramide was found to bind specifically to and activate protein kinase c-Raf, leading to subsequent activation of the extracellular signal-regulated kinase (ERK) module in mesangial cells. We found also that ceramide binds to and differentially modulates the activity of distinct protein kinase C isoenzymes. These data are discussed in the context of interleukin 1beta-induced inflammatory gene expression in mesangial cells.
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Affiliation(s)
- J Pfeilschifter
- Zentrum der Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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64
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Chang SL, Wu GD, Patel NA, Vidal EL, Fiala M. The effects of interaction between morphine and interleukin-1 on the immune response. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 437:67-72. [PMID: 9666258 DOI: 10.1007/978-1-4615-5347-2_8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The findings presented here clearly indicate an association between opioid- and cytokine-dependent systems. Exposure to exogenous opioids can produce profound effects on IL-1-mediated immune responses. Chronic exposure to morphine appears to disrupt the brain-immune axis by desensitizing the IL-1 activation of the HPA axis, and consequently potentiate the LEA response to IL-1. On the other hand, endogeneous IL-1, secreted in response to disease or stress, may alter the endogenous opioid pathway by inducing the expression of opioid receptors in endothelial cells. Clinically, the potential impact on the body's defense mechanisms resulting from the interaction between opioids, such as morphine, and cytokines, such as IL-1, can be substantial. Further investigation of this interaction is essential to understanding the extent of damage in human body caused by drugs of abuse, such as morphine.
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Affiliation(s)
- S L Chang
- Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA
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65
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Kanemaki T, Kitade H, Kaibori M, Sakitani K, Hiramatsu Y, Kamiyama Y, Ito S, Okumura T. Interleukin 1beta and interleukin 6, but not tumor necrosis factor alpha, inhibit insulin-stimulated glycogen synthesis in rat hepatocytes. Hepatology 1998; 27:1296-303. [PMID: 9581683 DOI: 10.1002/hep.510270515] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Recent evidence indicates that inflammatory cytokines are involved in changes of blood glucose concentrations and hepatic glucose metabolism in infectious diseases, including sepsis. However, little is known regarding how cytokines interact with glucoregulatory hormones such as insulin. The objective of the present study is to investigate if and how cytokines influence insulin-stimulated glycogen metabolism in the liver. Interleukin 1beta (IL-1beta) and interleukin 6 (IL-6) markedly inhibited the increase of glycogen deposition stimulated by insulin in primary rat hepatocyte cultures; however, tumor necrosis factor alpha had no effect. Labeling experiments revealed that both cytokines counteracted insulin action by decreasing [14C]-glucose incorporation into glycogen and by increasing [14C]-glycogen degradation. Furthermore, it was discovered that IL-1beta and IL-6 inhibited glycogen synthase activity and, in contrast, accelerated glycogen phosphorylase activity. In experiments with kinase inhibitors, serine/threonine kinase inhibitor K252a blocked IL-1beta- and IL-6-induced inhibitions of glycogen deposition, as well as glycogen synthase activity, whereas another kinase inhibitor staurosporine blocked only IL-6-induced inhibition. Tyrosine kinase inhibitor herbimycin A blocked only IL-1beta-induced inhibition. These results indicate that IL-1beta and IL-6 regulate insulin-stimulated glycogen synthesis through different pathways involving protein phosphorylation in hepatocytes. They may mediate the change of hepatic glucose metabolism under pathological and even physiological conditions by modifying insulin action in vivo.
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Affiliation(s)
- T Kanemaki
- First Department of Surgery, Kansai Medical University, Moriguchi, Osaka, Japan
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66
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Yoon DY, Dinarello CA. Antibodies to Domains II and III of the IL-1 Receptor Accessory Protein Inhibit IL-1β Activity But Not Binding: Regulation of IL-1 Responses Is Via Type I Receptor, Not the Accessory Protein. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.7.3170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The IL-1R accessory protein (IL-1RAcP) plays a role in IL-1R signaling by forming a complex with IL-1RI bound to the IL-1 ligand. We identified four hydrophilic peptide regions of the extracellular IL-1RAcP that may be available for complex formation (peptide 1, 71–83 domain I; peptide 2, 204–211 domain II; peptide 3, 282–292 domain III; and peptide 4, 304–314 domain III). These peptides were synthesized, coupled to keyhole limpet hemocyanin, and used to produce rabbit antisera. Each affinity-purified antiserum showed specificity for the respective peptide without cross-reactivity. Anti-peptide 2, 3, and 4 recognized surface expression of IL-1RAcP on the Th2 D10S cells by FACS and inhibited IL-1-driven proliferation. Anti-peptide 4 recognized intact IL-1RAcP and soluble IL-1RAcP. Anti-IL-1RAcP-peptide 4, which targets the terminal segment of domain III, inhibited 80% of IL-1β-driven proliferation of D10S cells. However, these IL-1RAcP Abs had no effect on the activity of human or mouse IL-1α. Whereas IL-1β down-regulated IL-1RI surface expression (p < 0.05), there was no change in the surface expression of IL-1RAcP. Moreover, murine IL-10 increased surface expression of IL-1RI, but did not affect expression of IL-1RAcP or the proliferation of D10S cells. Steady state levels of mRNA for IL-1RAcP and IL-1RI in D10S cells showed a similar pattern to that of surface expression of the respective receptors. We conclude that 1) blocking IL-1RAcP inhibits IL-1 signaling in D10S cells, 2) domains-II and III may be involved in complex formation with IL-1RI, 3) IL-1RAcP is not regulated as is IL-1RI in the same cells, and 4) IL-1 responsiveness is dependent on the expression of IL-1RI, not IL-1RAcP.
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Affiliation(s)
- Do-Young Yoon
- Division of Infectious Diseases, University of Colorado Health Sciences Center, Denver, CO 80262
| | - Charles A. Dinarello
- Division of Infectious Diseases, University of Colorado Health Sciences Center, Denver, CO 80262
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67
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Miyazawa K, Mori A, Yamamoto K, Okudaira H. Transcriptional roles of CCAAT/enhancer binding protein-beta, nuclear factor-kappaB, and C-promoter binding factor 1 in interleukin (IL)-1beta-induced IL-6 synthesis by human rheumatoid fibroblast-like synoviocytes. J Biol Chem 1998; 273:7620-7. [PMID: 9516466 DOI: 10.1074/jbc.273.13.7620] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The involvement of interleukin (IL)-6 in the pathogenesis of rheumatoid arthritis (RA) has been recently demonstrated. IL-1beta stimulated rheumatoid fibroblast-like synoviocytes (FLSs) to produce IL-6 in a concentration- and time-dependent manner. In the present study we investigated how the IL-6 promoter is transcriptionally regulated in rheumatoid FLSs in response to a physiologically relevant mediator of inflammation, IL-1beta. Deletion analysis showed that the IL-6 promoter is regulated by two positive elements (located at -159 to -142 base pairs (bp) and -77 to -59 bp). Electrophoretic mobility shift assays revealed that CCAAT/enhancer binding protein-beta (C/EBPbeta) binding to nucleotides -159 to -142 bp was constitutively present. The probe corresponding to nucleotides -77 to -59 bp gave three positive bands. The two slower migrating bands were induced by IL-1beta and comprised an nuclear factor (NF)-kappaB p50/p65 heterodimer and a p65/p65 homodimer. The faster migrating band was constitutively expressed and identified as Epstein-Barr virus C-promoter binding factor 1, CBF1. Site-specific mutagenesis analysis demonstrated that the NF-kappaB and CBF1 binding elements regulated inducible activity of the IL-6 promoter in response to IL-1beta stimulation, whereas the C/EBPbeta binding element mainly regulated basal activity. We also provide the first evidence that CBF1 functions as a positive regulator of human IL-6 gene transcription.
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Affiliation(s)
- K Miyazawa
- Department of Medicine and Physical Therapy, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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68
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Utal AK, Stopka AL, Coleman PD. Interleukin-1 beta stimulates mitogen-activated protein kinase in U373 astrocytoma cells without the production of lipid second messengers. Neurochem Res 1998; 23:235-42. [PMID: 9475519 DOI: 10.1023/a:1022493228015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
IL-1 beta is one of the cytokines known to affect astroglial cells in normal brain development, brain injury and neurodegenerative diseases. IL-1 beta causes astrocytes to become more reactive, alter the expression and release of molecules and in some cases to proliferate. We have investigated the mitogenic effect and signal transduction pathway induced by IL-1 beta in U373 cells, a human astrocytoma cell-line. Recombinant human IL-1 beta induced mitogenesis of U373 cells in a dose-dependent fashion as assessed by tritiated thymidine incorporation. The following signal transduction mechanisms, reported to be induced in other systems by IL-1 beta, were investigated in U373 cells: (1) activation of phosphatidylcholine-specific phospholipase C as assayed by incorporation of tritiated choline into cellular phospholipids, (2) production of diacylglycerol, a lipid second messenger, (3) activation of sphingomyelinase, and (4) activation of mitogen-activated protein kinase (MAPK). Of these, IL-1 beta activated only MAPK. In cultured rat astrocytes, IL-1 beta caused activation of MAPK without inducing proliferation.
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Affiliation(s)
- A K Utal
- Dept. of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, NY 14642, USA.
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69
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Vidal EL, Patel NA, Wu G, Fiala M, Chang SL. Interleukin-1 induces the expression of mu opioid receptors in endothelial cells. IMMUNOPHARMACOLOGY 1998; 38:261-6. [PMID: 9506826 DOI: 10.1016/s0162-3109(97)00085-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Immunocytokines, such as interleukin-1 (IL-1), have been shown to be involved in the activation and/or induction of a variety of transcription factors which may modulate the expression of genes possessing DNA binding sites on which these transcription factors act. The promoter DNA sequence of the mu opioid receptor gene contains IL-1 response elements such as NF-IL6, and, therefore, the receptor gene may be responsive to IL-1. To investigate the effect of IL-1 on the opioid receptor gene, the in vitro expression of mu opioid receptor mRNA in neural microvascular endothelial cells (NMVEC) was determined before and after IL-1 treatment. PCR analysis revealed that there was virtually no mu opioid receptor expression at basal levels and no increase after either IL-1alpha or IL-1beta treatment. However, simultaneous treatment with both IL-1alpha and IL-1beta increased mu opioid receptor expression. This upregulation of mu opioid receptor expression provides direct evidence of a relationship between opioid and cytokine actions, and suggests that opioid-dependent pathways may be modulated in the disease state.
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MESH Headings
- Cells, Cultured
- DNA Primers
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Humans
- Interleukin-1/pharmacology
- Polymerase Chain Reaction
- Promoter Regions, Genetic/genetics
- RNA, Messenger/analysis
- Receptors, Opioid, mu/biosynthesis
- Receptors, Opioid, mu/genetics
- Tumor Cells, Cultured
- Up-Regulation/drug effects
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Affiliation(s)
- E L Vidal
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA
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70
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Abstract
Interleukin-1 (IL-1) is the prototypic pro-inflammatory cytokine. There are two forms of IL-1, IL-1alpha and IL-1beta and in most studies, their biological activities are indistinguishable. IL-1 affects nearly every cell type, often in concert with another pro-inflammatory cytokine, tumor necrosis factor (TNF). Although IL-1 can upregulate host defenses and function as an immunoadjuvant, IL-1 is a highly inflammatory cytokine. The margin between clinical benefit and unacceptable toxicity in humans is exceedingly narrow. In contrast, agents that reduce the production and/or activity of IL-1 are likely to have an impact on clinical medicine. The synthesis, processing, secretion and activity of IL-1, particularly IL-1beta, are tightly regulated events. A unique aspect of cytokine biology is the naturally occurring IL-1 receptor antagonist (IL-1Ra). IL-1Ra is structurally similar to IL-1beta but lacking agonist activity is used in clinical trials to reduce disease severity. In addition, regulation of IL-1 activity extends to low numbers of surface receptors, circulating soluble receptors and a cell surface "decoy" receptor to down-regulate responses to IL-1beta. This review updates the current knowledge on IL-1.
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Affiliation(s)
- C A Dinarello
- Department of Medicine, University of Colorado Health Science Center, Denver 80262, USA
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71
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Guesdon F, Knight CG, Rawlinson LM, Saklatvala J. Dual specificity of the interleukin 1- and tumor necrosis factor-activated beta casein kinase. J Biol Chem 1997; 272:30017-24. [PMID: 9374476 DOI: 10.1074/jbc.272.48.30017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Tumor necrosis factor (TNF) and interleukin 1 (IL1) activate a protein kinase, TIP kinase, which phosphorylates beta casein in vitro. We have now identified its main phosphorylation site on beta casein, Ser124 (Km approximately 28 mu M), and a minor phosphorylation site, Ser142 (Km approximately 0.7 mM). The sequence motif that determined the phosphorylation of Ser124 by the kinase was studied with synthetic peptides bearing deletions or substitutions of the neighboring residues. This allowed synthesis of improved substrates (Km approximately 6 mu M) and showed that efficient phosphorylation of Ser124 was favored by the presence of large hydrophobic residues at positions +1, +9, +11, and +13 (counted relative to the position of the phosphoacceptor amino acid) and of a cysteine at position -2. Peptides in which Ser124 was replaced by tyrosine were also phosphorylated by TIP kinase, showing it to have dual specificity. It is unable to phosphorylate the MAP kinases in vitro and is therefore not directly involved in their activation. Its biochemical characteristics indicate that TIP kinase is a novel dual specificity kinase, perhaps related to the mixed lineage kinases. It copurified with a phosphoprotein of about 95 kDa, which could correspond either to the autophosphorylated kinase or to an associated substrate.
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Affiliation(s)
- F Guesdon
- Department of Cell Adhesion and Signaling, Strangeways Research Laboratory, Cambridge, CB1 4RN, United Kingdom.
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72
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Reddy SA, Huang JH, Liao WS. Phosphatidylinositol 3-kinase in interleukin 1 signaling. Physical interaction with the interleukin 1 receptor and requirement in NFkappaB and AP-1 activation. J Biol Chem 1997; 272:29167-73. [PMID: 9360994 DOI: 10.1074/jbc.272.46.29167] [Citation(s) in RCA: 198] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The signaling mechanisms utilized by the proinflammatory cytokine interleukin-1 (IL-1) to activate the transcription factors NFkappaB and activator protein-1 (AP-1) are poorly defined. We present evidence here that IL-1 not only stimulates a dramatic increase in phosphatidylinositol 3-kinase (PI 3-kinase) activity but also induces the physical interaction of its type I receptor with the p85 regulatory subunit of PI 3-kinase. Furthermore, two PI 3-kinase-specific inhibitors, wortmannin and a dominant-negative mutant of the p85 subunit, inhibited IL-1-induced activation of both NFkappaB and AP-1. Transient transfection experiments indicated that whereas overexpression of PI 3-kinase may be sufficient to induce AP-1 and increase nuclear c-Fos protein levels, PI 3-kinase may need to cooperate with other IL-1-inducible signals to fully activate NFkappaB-dependent gene expression. In this regard, cotransfection studies suggested that PI 3-kinase may functionally interact with the recently-identified IL-1-receptor-associated kinase to activate NFkappaB. Our results thus indicate that PI 3-kinase is a novel signal transducer in IL-1 signaling and that it may differentially mediate the activation of NFkappaB and AP-1.
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Affiliation(s)
- S A Reddy
- Department of Biochemistry and Molecular Biology, Box 117, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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73
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Abstract
Hepatic P450 activities are profoundly affected by various infectious and inflammatory stimuli, and this has clinical and toxicological consequences. Whereas the expression of most P450s in the liver is suppressed, some are induced. Many of the effects observed in vivo can be mimicked by pro-inflammatory cytokines and IFNs, and P450s are differentially regulated by these agents. Therefore, different cytokine profiles and concentrations in the vicinity of the hepatocyte in different models of inflammation may result in qualitatively and quantitatively different effects on populations of P450s. In addition to cytokines, glucocorticoids may have an important role in P450 regulation in stress conditions, including that caused by inflammatory stimuli. Although in many cases the decreases in activity are due primarily to a down-regulation of P450 gene transcription, it is likely that modulation of RNA and protein turnover, as well as enzyme inhibition, contributes to some of the observed effects. The mechanisms whereby these effects are produced may also vary with both the P450 under study and the time course of the effect. The complexity of the P450 response to inflammation and infection means that all of the above factors must be considered when trying to predict the effect of a given infectious or inflammatory condition on the clinical or toxic response of humans or animals to an administered drug or toxin. The question of whether the down-regulation of the hepatic P450 system to inflammation or infection is a homeostatic or pathological response cannot be answered at present. It is difficult to discern the physiological benefit of reducing hepatic P450 activities, unless it is to prevent the generation of reactive oxygen species generated by uncoupled catalytic turnover of the enzymes. On the other hand, as we proposed some years ago [64], the suppression of P450 may be due to the liver's need to utilize its transcriptional machinery and energy for the synthesis of APPs involved in the inflammatory response. In that case, one could ask why the organism has gone to the trouble of employing differential mechanisms for suppression of P450. One answer could be that the response evolved after the divergence of many of the P450 genes, necessitating the evolution of multiple redundant mechanisms for P450 suppression. In contrast to the down-regulation of P450s in the liver, the induction of several forms in this and other tissues suggests a more specific homeostatic role of these effects, e.g., in generation or catabolism of bioactive metabolites.
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Affiliation(s)
- E T Morgan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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74
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Borge L, Lemare F, Demignot S, Adolphe M. Restoration of the differentiated functions of serially passaged chondrocytes using staurosporine. In Vitro Cell Dev Biol Anim 1997; 33:703-9. [PMID: 9358286 DOI: 10.1007/s11626-997-0128-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Among the various directions explored in order to have a large number of differentiated articular chondrocytes easily available, the restoration of the differentiated properties after cell multiplication in monolayer has been proposed. It has been clearly shown that the synthesis of cartilage proteoglycans and type II collagen synthesis is coincident with the presence of a faint microfibrillar architecture but is absent in chondrocytes showing well-defined actin cables. Staurosporin, mainly described as a protein kinase C inhibitor, has also been shown to rapidly induce the disruption of the actin microfilaments. The purpose of this paper was to investigate whether properties of differentiated chondrocytes were reinitiated upon staurosporin treatment of serially passaged chondrocytes. Results showed, after staurosporine treatment of cells at Passage two for 5 d, complete suppression of type I and type III collagen synthesis and induction of type II collagen synthesis and of Alcian blue stainable matrix. Additionally, we showed that staurosporin restored metabolic responses that chondrocytes in primary culture exhibit upon interleukin-1 beta treatment (decrease of Alcian blue- positive cells, induction of expression of the 92 kDa gelatinase, nitric oxide production). We conclude that staurosporin is a potent redifferentiating agent of articular chondrocytes that have been subcultured up to Passage two for multiplication. Taking into account that the cellularity of cartilage is very low, staurosporine-treated chondrocytes could be useful as an alternative cellular model to evaluate pharmacotoxicological effects of drugs.
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Affiliation(s)
- L Borge
- Laboratoire de Pharmacologie Cellulaire de l'Ecole Pratique des Hautes Etudes, Centre de Recherches Biomédicales des Cordeliers, Paris, France
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75
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Keenan C, Long A, Kelleher D. Protein kinase C and T cell function. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1358:113-26. [PMID: 9332448 DOI: 10.1016/s0167-4889(97)00080-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- C Keenan
- Department of Biochemistry, Oxford University, UK.
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76
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Kelley KW, Hutchison K, French R, Bluthé RM, Parnet P, Johnson RW, Dantzer R. Central interleukin-1 receptors as mediators of sickness. Ann N Y Acad Sci 1997; 823:234-46. [PMID: 9292049 DOI: 10.1111/j.1749-6632.1997.tb48395.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
These data establish that cytokines, such as IL-1, can act on specific receptors within the brain to induce many symptoms of sickness. A number of inflammatory stimuli in the periphery can activate both the transcription and translation of IL-1 within the central nervous system. It will now be important to determine if similar central IL-1 pathways are activated during SLE and whether these central inflammatory cytokines are involved in the neurologic complications that often accompany this disease.
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Affiliation(s)
- K W Kelley
- Laboratory of Immunophysiology, University of Illinois, Urbana 61801, USA.
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77
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Nikolova-Karakashian M, Morgan ET, Alexander C, Liotta DC, Merrill AH. Bimodal regulation of ceramidase by interleukin-1beta. Implications for the regulation of cytochrome p450 2C11. J Biol Chem 1997; 272:18718-24. [PMID: 9228043 DOI: 10.1074/jbc.272.30.18718] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Interleukin 1beta (IL-1beta) induces the hydrolysis of sphingomyelin (SM) to ceramide (Cer) in primary cultures of rat hepatocytes, and Cer has been proposed to play a role in the down-regulation of cytochrome P450 2C11 (CYP2C11) and induction of alpha1-acid glycoprotein (AGP) by this cytokine (Chen, J., Nikolova-Karakashian, M., Merrill, A. H. & Morgan, E. T. (1995) J. Biol. Chem. 270, 25233-25238). Nonetheless, some of the features of the down-regulation of CYP2C11 do not fit a simple model of Cer as a second messenger as follows: N-acetylsphinganine (C2-DHCer) is as potent as N-acetylsphingosine (C2-Cer) in suppression of CYP2C11; the IL-1beta concentration dependence for SM turnover is different from that for the increase in Cer; and the increase in Cer mass is not equivalent to the amount of SM hydrolyzed nor the time course of SM hydrolysis. In this article, we report that these discrepancies are due to activation of ceramidase by the low concentrations of IL-1beta ( approximately 2.5 ng/ml) that maximally down-regulate CYP2C11 expression, whereas higher IL-1beta concentrations (that induce AGP) do not activate ceramidase and allow Cer accumulation. This bimodal concentration dependence is demonstrated both by in vitro ceramidase assays and in intact hepatocytes using a fluorescence Cer analog, 6-((N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-Cer (NBD-Cer), and following release of the NBD-fatty acid. IL-1beta increases both acid and neutral ceramidase activities, which appear to be regulated by tyrosine phosphorylation because pretreatment of hepatocytes with sodium vanadate increases (and 25 microM genistein reduces) the basal and IL-1beta-stimulated ceramidase activities. Since these findings suggested that sphingosine (and, possibly, subsequent metabolites) is the primary mediator of the down-regulation of CYP2C11 by IL-1beta, the effects of exogenous sphingosine and C2-Cer on expression of this gene were compared. Sphingosine was more potent than C2-Cer in down-regulation of CYP2C11 when added alone or with fumonisin B1 to block acylation of the exogenous sphingosine. Furthermore, the suppression of CYP2C11 by C2-Cer (and C2-DHCer) is probably mediated by free sphingoid bases, rather than the short chain Cer directly, because both are hydrolyzed by hepatocytes and increase cellular levels of sphingosine and sphinganine. From these observations we conclude that sphingosine, possibly via sphingosine 1-phosphate, is a mediator of the regulation of CYP2C11 by IL-1beta in rat hepatocytes and that ceramidase activation provides a "switch" that determines which sphingolipids are elevated by this cytokine to produce multiple intracellular responses.
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78
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Coogan A, O'Connor JJ. Inhibition of NMDA receptor-mediated synaptic transmission in the rat dentate gyrus in vitro by IL-1 beta. Neuroreport 1997; 8:2107-10. [PMID: 9243593 DOI: 10.1097/00001756-199707070-00004] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The action of interleukin-1 beta (IL-1 beta) and its receptor antagonist IL-1ra were investigated on dual component, isolated AMPA and NMDA field excitatory post-synaptic potentials (EPSP) and on the induction and maintenance of long-term potentiation in the rat dentate gyrus in vitro. Perfusion with IL-1 beta (1 ng/ml) for 1 h had no significant effect on the dual component EPSP or the isolated AMPA-EPSP. In contrast IL-1 beta had a significant inhibitory effect on the isolated NMDA-EPSP amplitude (54 +/- 7% at 1 h compared with controls; n = 9; p < 0.001). This effect was fully antagonized in the presence of 100 ng/ml IL-1 receptor antagonist. IL-1 beta also inhibited LTP of the dual component EPSP but had no effect on the maintenance phase when applied post-induction of LTP. This study demonstrates for the first time that the inhibitory effect of IL-1 beta on LTP in the dentate gyrus may be at least partially due to a block of post-synaptic NMDA receptors.
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Affiliation(s)
- A Coogan
- Department of Human Anatomy and Physiology, University College, Dublin, Ireland
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79
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Mahon TM, Matthews JS, O'Neill LA. Staurosporine, but not Ro 31-8220, induces interleukin 2 production and synergizes with interleukin 1alpha in EL4 thymoma cells. Biochem J 1997; 325 ( Pt 1):39-45. [PMID: 9224627 PMCID: PMC1218526 DOI: 10.1042/bj3250039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Protein kinase C (PKC) has been implicated in interleukin 1 (IL1) signal transduction in a number of cellular systems, either as a key event in IL1 action or as a negative regulator. Here we have examined the effects of two PKC inhibitors, staurosporine and the more selective agent Ro 31-8220, on IL1 responses in the murine thymoma line EL4.NOB-1. A 1 h pulse of staurosporine was found to strongly potentiate the induction of IL2 by IL1alpha in these cells. In contrast, neither a pulse nor prolonged incubation with Ro 31-8220 affected the response to IL1alpha. Both agents blocked the response to PMA, however. A 1 h pulse of staurosporine was also found to induce IL2 production on its own, activate the transcription factor nuclear factor kappaB (NFkappaB) and increase the expression of a NFkappaB-linked reporter gene. It synergized with IL1alpha in all of these responses. Ro 31-8220 was again without effect, although both staurosporine and Ro 31-8220 blocked the activation of NFkappaB by PMA. Finally, staurosporine caused the translocation of PKC-alpha and -epsilon, and to a lesser extent PKC-beta, but not PKC-θ or -zeta, from the cytosol to the membrane, although a similar effect was observed with Ro 31-8220. The results suggest that PKC is not involved in IL1alpha signalling in EL4 cells. Furthermore, the potentiating effect of staurosporine on IL1alpha action does not involve PKC inhibition, and is likely to be at the level of NFkappaB activation.
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Affiliation(s)
- T M Mahon
- Department of Biochemistry, Trinity College Dublin, Dublin 2, Ireland
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80
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Finder JD, Litz JL, Blaskovich MA, McGuire TF, Qian Y, Hamilton AD, Davies P, Sebti SM. Inhibition of protein geranylgeranylation causes a superinduction of nitric-oxide synthase-2 by interleukin-1beta in vascular smooth muscle cells. J Biol Chem 1997; 272:13484-8. [PMID: 9153192 DOI: 10.1074/jbc.272.21.13484] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Recently, we have designed farnesyltransferase and geranylgeranyltransferase I inhibitors (FTI-277 and GGTI-298) that selectively block protein farnesylation and geranylgeranylation, respectively. In this study, we describe the opposing effects of these inhibitors on interleukin-1beta (IL-1beta)-stimulated induction of nitric-oxide synthase-2 (NOS-2) in rat pulmonary artery smooth muscle cells (RPASMC) and rat hepatocytes. Pretreatment of cells with GGTI-298 caused a superinduction of NOS-2 by IL-1beta. RPASMC treated with GGTI-298 (10 microM) prior to IL-1beta (10 ng/ml) expressed levels of NOS-2 protein five times higher than those exposed to IL-1beta alone. This superinduction of NOS-2 protein by pretreatment with GGTI-298 resulted in nitrite concentrations in the medium that were 5-fold higher at 10 ng/ml IL-1beta and 10-fold higher at 1 ng/ml IL-1beta. Furthermore, NOS-2 mRNA levels in RPASMC were also increased 6- and 14-fold (at 10 and 1 ng/ml IL-1beta, respectively) when the cells were pretreated with GGTI-298. In contrast, treatment of cells with the inhibitor of protein farnesylation, FTI-277 (10 microM), blocked IL-1beta-induced NOS-2 expression at mRNA and protein levels. Pretreatment with lovastatin, an inhibitor of protein prenylation, resulted in superinduction of NOS-2. This superinduction was reversed by geranylgeraniol, but not by farnesol, further confirming that inhibition of geranylgeranylation, not farnesylation, is responsible for enhanced NOS-2 expression. The results demonstrate that a farnesylated protein(s) mediates IL-1beta induction of NOS-2, whereas a geranylgeranylated protein(s) represses this induction.
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Affiliation(s)
- J D Finder
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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81
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Abstract
The unexpected notion that disease resistance mechanisms may use similar regulatory pathways to developmental processes has emerged from recent advances in understanding signal transduction pathways in insects, mammals and plants.
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Affiliation(s)
- I Wilson
- Carnegie Institution of Washington, Department of Plant Biology, 290 Panama Street, Stanford, California 94305, USA
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82
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McHowat J, Liu S. Interleukin-1beta stimulates phospholipase A2 activity in adult rat ventricular myocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:C450-6. [PMID: 9124287 DOI: 10.1152/ajpcell.1997.272.2.c450] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have examined whether interleukin (IL)-1beta modulates phospholipase A2 (PLA2) activity in ventricular myocytes. PLA2 activity was measured in isolated membrane and cytosol fractions with (16:0,[3H]18:1) plasmenylcholine and (16:0,[3H]18:1) phosphatidylcholine in the absence and presence of Ca2+. When measured in the absence of Ca2+ with plasmenylcholine, exposure to 5 ng/ml IL-1beta caused an increase in membrane-associated PLA2 activity for 10 min that returned to basal levels by 20 min. In the presence of Ca2+ with phosphatidylcholine, IL-1beta had no effect on membrane-associated PLA2 but decreased cytosolic PLA2 activity. Additionally, IL-1beta caused an increase in arachidonic acid release in 20 min. Pretreatment with E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one, a selective Ca2+-independent PLA2 inhibitor, blocked IL-1beta-induced increases in both PLA2 activity and arachidonic acid release. Exposure to IL-1 receptor antagonist (IL-1RA) alone had no effect on membrane-associated PLA2 activity. When incubated with IL-1beta, IL-1RA inhibited the IL-1beta-enhanced PLA2 activity. These results show that, via activation of its receptors, IL-1beta stimulates specifically membrane-associated Ca2+-independent plasmalogen-selective PLA2 in rat ventricular myocytes.
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Affiliation(s)
- J McHowat
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock 72205, USA
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83
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Brennan P, O'Neill LA. 2-mercaptoethanol restores the ability of nuclear factor kappa B (NF kappa B) to bind DNA in nuclear extracts from interleukin 1-treated cells incubated with pyrollidine dithiocarbamate (PDTC). Evidence for oxidation of glutathione in the mechanism of inhibition of NF kappa B by PDTC. Biochem J 1996; 320 ( Pt 3):975-81. [PMID: 9003388 PMCID: PMC1218023 DOI: 10.1042/bj3200975] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The metal chelator and anti-oxidant pyrollidine dithiocarbamate (PDTC) has been used extensively in studies implicating reactive oxygen intermediates in the activation of nuclear factor kappa B (NF kappa B). In agreement with other studies, we have shown that PDTC inhibits NF kappa B activation in response to the pro-inflammatory cytokines interleukin 1 (IL1) and tumour necrosis factor (TNF). However, we have found that the inhibition was reversed by treatment of inhibited nuclear extracts with the reducing agent 2-mercaptoethanol. This was observed in extracts prepared from IL1-treated EL4.NOB-1 thymoma cells and TNF-treated Jurkat E6.1 lymphoma cells. These results suggested that the inhibition was caused by oxidation of NF kappa B on a sensitive thiol, possibly on the p50 subunit (which was detected in NF kappa B complexes in both cell types), and not by inhibition of the activation pathway. The possibility that PDTC was acting as a pro-oxidant was therefore investigated. PDTC caused an increase in oxidized glutathione, suggesting that it acts as an oxidizing agent in the cells tested rather than as an anti-oxidant. Similar results were obtained with diamide, a compound designed to oxidize glutathione. Finally, an increase in the ratio of oxidized to reduced glutathione was shown to inhibit NF kappa B-DNA binding in vitro. On the basis of these results we suggest that, while NF kappa B activation is unaffected by PDTC, DNA binding is inhibited through a mechanism involving a shift towards oxidizing conditions, and that this is the mechanism of action of both PDTC and diamide in the cells tested here.
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Affiliation(s)
- P Brennan
- Department of Biochemistry, Trinity College, Dublin 2, Ireland
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84
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de-Mello MA, Flodström M, Eizirik DL. Ebselen and cytokine-induced nitric oxide synthase expression in insulin-producing cells. Biochem Pharmacol 1996; 52:1703-9. [PMID: 8986132 DOI: 10.1016/s0006-2952(96)00520-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Interleukin-1 (IL-1) may be a mediator of beta-cell damage in insulin-dependent diabetes mellitus (IDDM). The IL-1 mechanism of action on insulin-producing cells probably includes activation of the transcription nuclear factor kappa B (NF-kappa B), increased transcription of the inducible form of nitric oxide synthase (iNOS) and the subsequent production of nitric oxide (NO). Reactive oxygen intermediates, particularly H2O2, have been proposed as second messengers for NF-kappa B activation. In the present study, we tested whether ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), a glutathione peroxidase mimicking compound, could counteract the effects of IL-1 beta, H2O2 and alloxan in rat pancreatic islets and in the rat insulinoma cell line RINm5F (RIN cells). Some of these experiments were also reproduced in human pancreatic islets. Ebselen (20 microM) prevented the increase in nitrite production by rat islets exposed to IL-1 beta for 6 hr and induced significant protection against the acute inhibitory effects of alloxan or H2O2 exposure, as judged by the preserved glucose oxidation rates. However, ebselen failed to prevent the increase in nitrite production and the decrease in glucose oxidation and insulin release by rat islets exposed to IL-1 beta for 24 hr. Ebselen prevented the increase in nitrite production by human islets exposed for 14 hr to a combination of cytokines (IL-1 beta, tumor necrosis factor-alpha and interferon-gamma). In RIN cells, ebselen counteracted both the expression of iNOS mRNA and the increase in nitrite production induced by 6 hr exposure to IL-beta but failed to block IL-1 beta-induced iNOS expression following 24 hr exposure to the cytokine. Moreover, ebselen did not prevent IL-1 beta-induced NF-kappa B activation. As a whole, these data indicate that ebselen partially counteracts cytokine-induced NOS activation in pancreatic beta-cells, an effect not associated with inhibition of NF-kappa B activation.
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Affiliation(s)
- M A de-Mello
- Department of Medical Cell Biology, Uppsala University, Sweden
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85
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Ohtsuki T, Ruetzler CA, Tasaki K, Hallenbeck JM. Interleukin-1 mediates induction of tolerance to global ischemia in gerbil hippocampal CA1 neurons. J Cereb Blood Flow Metab 1996; 16:1137-42. [PMID: 8898685 DOI: 10.1097/00004647-199611000-00007] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A series of experiments was performed to determine the role of interleukin (IL)-1 in the induction of tolerance to global ischemia in Mongolian gerbils. In Group I, a 2-min "preconditioning" ischemia protected CA1 hippocampal neurons in gerbils subjected to 3.5 min ischemia 3 days later. CA1 neuronal density was: sham, 171 +/- 3/mm; 3.5 min ischemia, 30 +/- 30/mm; 2 and 3.5 min ischemia 162 +/- 6/mm. Experiments in Group II addressed the role of IL-1 in the induction of tolerance by sublethal ischemia. Arterial IL-1 alpha and IL-1 beta became elevated between 1 and 3 days after a 2-min ischemic exposure. IL-1 alpha was: sham, 6.4 +/- 0.6 ng/ml; and 2-day, 10.2 +/- 1.2 ng/ml. IL-1 beta was: sham, 6.4 +/- 0.5 ng/ml; and 2-day, 17.3 +/- 2 ng/ml. Recombinant human IL-1 receptor antagonist (IL-1ra) i.p. blocked ischemic tolerance induction by 2-min preconditioning ischemia: 2-min ischemia + vehicle, 162 +/- 6/mm; and 2-min ischemia + IL-1ra, 67 +/- 17/mm. Experiments in Group III assessed the capacity of IL-1 to induce tolerance to brain ischemia. IL-1 alpha i.p. (0, 10, 20 micrograms/kg) for 3 days prior to 3.5-min forebrain ischemia provided significant CA1 neuroprotection in a dose-dependent manner: 2 +/- 2, 68 +/- 83, and 129 +/- 42/mm, respectively. IL-1 beta (15 micrograms/kg) in combination with either IL-1ra (100 mg/kg) or IL-1ra vehicle i.p. on the same schedule demonstrated a significant CA1 neuroprotection that could be nullified by IL-1ra: IL-1 beta + IL-1ra vehicle, 153 +/- 16/mm; and IL-1 beta + IL-1ra, 67 +/- 36/mm. Recognition that tolerance arises from stimulation of a known receptor (IL-1RI) permits molecular analysis of the intracellular signaling that is critical for production of that state.
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Affiliation(s)
- T Ohtsuki
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4128, USA
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86
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Communications. Br J Pharmacol 1996. [DOI: 10.1111/j.1476-5381.1996.tb17246.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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87
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Seki T, Gelehrter TD. Interleukin-1 induction of type-1 plasminogen activator inhibitor (PAI-1) gene expression in the mouse hepatocyte line, AML 12. J Cell Physiol 1996; 168:648-56. [PMID: 8816919 DOI: 10.1002/(sici)1097-4652(199609)168:3<648::aid-jcp17>3.0.co;2-v] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Type-1 plasminogen activator inhibitor (PAI-1), the major regulator of fibrinolysis, is an important component of the acute phase (AP) response, the coordinated systemic reaction of an organism to tissue injury. As part of a combined in vivo and in vitro study of AP regulation of PAI-1 gene expression in murine hepatocytes, we have characterized the cytokine regulation of PAI-1 gene expression in AML 12 cells, an established line of normal hepatocytes derived from an adult transgenic mouse overexpressing transforming growth factor alpha. Interleukin (IL)-1 caused a rapid and transient 4-fold increase in PAI-1 mRNA that was maximal at 1 h. Half-maximal induction by IL-1 was obtained at 50 U/ml and maximal effects were seen at approximately 500 U/ml. Tumor necrosis factor alpha induced PAI-1 mRNA accumulation with the same magnitude and time course as IL-1, and was not additive with IL-1. IL-6 and dexamethasone alone had no effect on PAI-1 mRNA accumulation and did not enhance the effect of IL-1. Transforming growth factor beta caused a sustained 5- to 7-fold increase in the accumulation of PAI-1 mRNA that was maximal after 2 to 4 h. The IL-1 induction of PAI-1 was inhibited by actinomycin D, but not by cycloheximide. Nuclear run-on studies demonstrated that IL-1 induced a rapid and transient increase in PAI-1 gene transcription that was maximal at 30 min. IL-1 did not stabilize PAI-1 mRNA, and might, in fact, accelerate its rate of decay. These data demonstrate that IL-1, a potent mediator of AP response, induces the accumulation of PAI-1 mRNA in murine hepatocytes, at least in part, by rapidly and transiently increasing the rate of transcription of the PAI-1 gene.
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Affiliation(s)
- T Seki
- Department of Human Genetics, The University of Michigan Medical School, Ann Arbor 48109-0618, USA
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88
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Berg DT, Calnek DS, Grinnell BW. Trans-repressor BEF-1 phosphorylation. A potential control mechanism for human ApoE gene regulation. J Biol Chem 1996; 271:4589-92. [PMID: 8617716 DOI: 10.1074/jbc.271.9.4589] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human apolipoprotein E is a plasma lipoprotein that appears to play an important protective role in the development of atherosclerosis. While little is known about the regulation of apoE, recent studies have shown that cytokines repress apoE synthesis both in vivo and in vitro. Furthermore, we have recently shown that the endogenous apoE gene is negatively regulated by the nuclear trans-repressor BEF-1 in the human HepG2 cell line. In this study we demonstrate that treatment of HepG2 cells with the cytokine interleukin-1 and interleukin-6 resulted in the induction of an isoform of BEF-1, designated B1. The induction of the B1 isoform could be blocked by the protein kinase inhibitor staurosporine, suggesting that B1 is a phosphorylated form of BEF-1. As further support, the B1 isoform could also be induced by phorbol ester, and subsequently inhibited by staurosporine, implicating a role for protein kinase C-mediated phosphorylation. Quantitation of the levels of the BEF-1 isoforms, and studies in the presence of cyclohexamide, provided evidence for the phosphorylation of an existing intracellular pool of BEF-1, with no change in the total intracellular level. Under conditions that generated increased levels of the B1 isoform, there was a concomitant and proportional decrease in the level of apoE mRNA. The effect did not appear to be the result of improved binding to the apoE regulatory region as the DNA binding affinity of B1 was identical to native BEF-1. Our data suggest that the regulation of apoE by BEF-1 is modulated by differential phosphorylation, possibly through the protein kinase C pathway.
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Affiliation(s)
- D T Berg
- Division of Cardiovascular Research, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, Indiana 46285, USA
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89
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Cunningham AJ, Murray CA, O'Neill LA, Lynch MA, O'Connor JJ. Interleukin-1 beta (IL-1 beta) and tumour necrosis factor (TNF) inhibit long-term potentiation in the rat dentate gyrus in vitro. Neurosci Lett 1996; 203:17-20. [PMID: 8742036 DOI: 10.1016/0304-3940(95)12252-4] [Citation(s) in RCA: 323] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of the cytokine, interleukin-1 beta (IL-1 beta), and its receptor antagonist IL-1ra, were studied on long-term potentiation in the dentate gyrus of rat hippocampal slices. Field excitatory postsynaptic potentials were recorded extracellularly in the molecular region of the dentate gyrus in response to stimulation of the medial perforant path. Low frequency synaptic transmission was unaffected by IL-1 beta (1 ng/ml), but pre-treatment with IL-1 beta completely blocked induction of long-term potentiation. Co-application of IL-1 beta and IL-1ra (100 ng/ml) attenuated the inhibitory effect of IL-1 beta. In parallel with these findings, we demonstrate that IL-1 beta also inhibited 45Ca influx into the slices. The inhibitory effect of IL-1 beta on induction was mimicked by tumour necrosis factor (TNF; 4.5 ng/ml) and lipopolysaccharide (LPS; 10 micrograms/ml). These results indicate a modulatory role for cytokines in hippocampus and suggest that the inhibitory effect of IL-1 beta on long-term potentiation may relate to its inhibitory effect on calcium channel activity.
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Affiliation(s)
- A J Cunningham
- Department of Human Anatomy and Physiology, University College, Dublin, Irela
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90
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91
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Rothwell NJ, Loddick SA, Stroemer P. Interleukins and cerebral ischaemia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1996; 40:281-98. [PMID: 8989625 DOI: 10.1016/s0074-7742(08)60724-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- N J Rothwell
- School of Biological Sciences, University of Manchester, UK
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92
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Mahon TM, O'Neill LA. Studies into the effect of the tyrosine kinase inhibitor herbimycin A on NF-kappa B activation in T lymphocytes. Evidence for covalent modification of the p50 subunit. J Biol Chem 1995; 270:28557-64. [PMID: 7499370 DOI: 10.1074/jbc.270.48.28557] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The tyrosine kinase inhibitor herbimycin A was found to block NF-kappa B stimulation in response to interleukin-1 and phorbol 12-myristate 13-acetate in EL4.NOB-1 thymoma cells and phorbol 12-myristate 13-acetate in Jurkat T lymphoma cells. The effect appeared not to involve inhibition of tyrosine kinase activation as neither interleukin-1 nor phorbol 12-myristate 13-acetate induced major changes in tyrosine phosphorylation in EL4.NOB-1 or Jurkat cells, respectively. Herbimycin A did not interfere with I kappa B-alpha degradation, and in unstimulated cells, it modified NF-kappa B prior to chemical dissociation with sodium deoxycholate. Because herbimycin A is thiol-reactive, we suspected that the target was the p50 subunit of NF-kappa B, which has a key thiol at cysteine 62. Herbimycin A inhibited DNA binding when added to nuclear extracts prepared from stimulated cells, which were shown to contain high levels of p50. Incubation of herbimycin A with 2-mercaptoethanol attenuated the effect. Herbimycin A was also shown to react directly with p50, blocking its ability to bind to the NF-kappa B consensus sequence. However, a mutant form of p50 in which cysteine 62 was mutated to serine was insensitive to herbimycin A. Finally, we demonstrated that the compound inhibited the expression of interleukin-2 (an NF-kappa B-regulated gene) in EL4.NOB-1 cells. These data therefore suggest that herbimycin A inhibits NF-kappa B by modifying the p50 subunit on cysteine 62 in the NF-kappa B complex, which blocks DNA binding and NF-kappa B-driven gene expression. The results urge caution in the use of herbimycin A as a specific tyrosine kinase inhibitor and suggest that the development of agents that selectively modify p50 may have potential as a means of inhibiting NF-kappa B-dependent gene transcription.
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Affiliation(s)
- T M Mahon
- Department of Biochemistry, Trinity College, Dublin, Ireland
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