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Yao Z, Qiu S, Wang L, Lu R, Zhou CL, Zhao PP, Li HQ, Gao WY. Tripeptide tyroserleutide enhances the antitumor effects of macrophages and stimulates macrophage secretion of IL-1beta, TNF-alpha, and NO in vitro. Cancer Immunol Immunother 2006; 55:56-60. [PMID: 16091933 PMCID: PMC11030685 DOI: 10.1007/s00262-005-0024-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Accepted: 05/05/2005] [Indexed: 11/26/2022]
Abstract
Tyroserleutide (YSL) is a type of active, low molecular weight polypeptide, comprised of three amino acids, which has antitumor effects. YSL has various advantages over the other bioactive peptides such as its low molecular weight, simple construction, nonimmunogenicity, specificity, few side effects, and ease of synthesis. However, the biological activities contributing to it's antitumor effects are not yet known. We studied the effects of YSL on the in vitro cytotoxic activity of BALB/c mice peritoneal macrophages (PEMphi) against the target tumor cell lines BEL-7402 and B16-F10. We also measured the concentrations of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and nitric oxide (NO) produced by YSL-activated Mphi, and we determined the concentrations of IL-1beta and NO secreted by YSL-activated murine macrophage RAW264.7 cells. YSL activated Mphi in vitro, inhibited BEL-7402 proliferation, enhanced PEMphi antitumor effects, and stimulated IL-1beta, TNF-alpha, and NO production by RAW264.7 cells. These data suggest that YSL activates the monocyte-macrophage system, which enhances Mphi antitumor effects against BEL-7402 and B16-F10 cells and stimulates the secretion by Mphi of cytotoxic effectors such as IL-1beta, TNF-alpha, and NO.
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Affiliation(s)
- Zhi Yao
- Department of Immunology, Tianjin Medical University, 22 Qixiangtai Road, Tianjin, 300070, China.
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Philpott M, Ching LM, Baguley BC. The antitumour agent 5,6-dimethylxanthenone-4-acetic acid acts in vitro on human mononuclear cells as a co-stimulator with other inducers of tumour necrosis factor. Eur J Cancer 2001; 37:1930-7. [PMID: 11576850 DOI: 10.1016/s0959-8049(01)00210-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
5,6-dimethylxanthenone-4-acetic acid (DMXAA), currently in phase I trials, demonstrates excellent activity against transplantable murine tumours with established vasculature. The induction of cytokines, particularly of tumour necrosis factor (TNF), appears to be critical to its action. We investigated TNF induction by DMXAA in cultured human peripheral blood leucocytes (HPBL). TNF was measured by an enzyme-linked immunosorbent assay after 8 h, and NF-kappaB induction by electrophoretic mobility shift assays (EMSA) after 2 h. DMXAA (800 microg/ml) had no effect alone on TNF production but augmented, by up to 4-fold, the ability of bacterial lipopolysaccharide (LPS) to induce TNF. Previously reported results showing TNF production by DMXAA alone were traced to the presence in an earlier batch of DMXAA of a small amount of LPS, the action of which could be blocked by polymyxin B. DMXAA stimulated TNF production by deacylated LPS, which alone had little effect. An antibody (MEM-18) to the CD14 receptor, while blocking the induction of TNF by LPS, enabled DMXAA to both synthesise TNF and induce NF-kappaB. The structurally related drug, flavone acetic acid (FAA), did not induce TNF or synergise with anti-CD14 antibody. DMXAA strongly augmented the ability of suboptimal concentrations of interleukin-1 (IL-1) (25 ng/ml), okadaic acid (OA) (20 ng/ml) and phorbol-12-myristate-13-acetate (PMA) (5 ng/ml) to induce TNF production, suggesting that it affects multiple pathways converging on NF-kappaB activation. Sodium salicylate, a drug reported to inhibit the beta-subunit of IkappaB kinase (IKK), appeared to competitively inhibit TNF production by DMXAA in the presence of anti-CD14 antibody. Taken together, the results indicate DMXAA acts in vitro on HPBL to co-stimulate TNF production by a wide variety of agents, and suggests that IKK is the target that mediates this action.
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Affiliation(s)
- M Philpott
- Auckland Cancer Society Research Centre, University of Auckland School of Medicine, Auckland, New Zealand
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3
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Valledor AF, Xaus J, Comalada M, Soler C, Celada A. Protein kinase C epsilon is required for the induction of mitogen-activated protein kinase phosphatase-1 in lipopolysaccharide-stimulated macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:29-37. [PMID: 10604989 DOI: 10.4049/jimmunol.164.1.29] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
LPS induces in bone marrow macrophages the transient expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1). Because MKP-1 plays a crucial role in the attenuation of different MAPK cascades, we were interested in the characterization of the signaling mechanisms involved in the control of MKP-1 expression in LPS-stimulated macrophages. The induction of MKP-1 was blocked by genistein, a tyrosine kinase inhibitor, and by two different protein kinase C (PKC) inhibitors (GF109203X and calphostin C). We had previously shown that bone marrow macrophages express the isoforms PKC beta I, epsilon, and zeta. Of all these, only PKC beta I and epsilon are inhibited by GF109203X. The following arguments suggest that PKC epsilon is required selectively for the induction of MKP-1 by LPS. First, in macrophages exposed to prolonged treatment with PMA, MKP-1 induction by LPS correlates with the levels of expression of PKC epsilon but not with that of PKC beta I. Second, Gö6976, an inhibitor selective for conventional PKCs, including PKC beta I, does not alter MKP-1 induction by LPS. Last, antisense oligonucleotides that block the expression of PKC epsilon, but not those selective for PKC beta I or PKC zeta, inhibit MKP-1 induction and lead to an increase of extracellular-signal regulated kinase activity during the macrophage response to LPS. Finally, in macrophages stimulated with LPS we observed significant activation of PKC epsilon. In conclusion, our results demonstrate an important role for PKC epsilon in the induction of MKP-1 and the subsequent negative control of MAPK activity in macrophages.
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Affiliation(s)
- A F Valledor
- Departament de Fisiologia (Biologia del Macròfag), Facultat de Biologia, Fundació August Pi i Sunyer, Universitat de Barcelona, Spain
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Shapira L, Sylvia VL, Halabi A, Soskolne WA, Van Dyke TE, Dean DD, Boyan BD, Schwartz Z. Bacterial lipopolysaccharide induces early and late activation of protein kinase C in inflammatory macrophages by selective activation of PKC-epsilon. Biochem Biophys Res Commun 1997; 240:629-34. [PMID: 9398616 DOI: 10.1006/bbrc.1997.7717] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Experiments from our and other laboratories have shown that specific inhibitors of protein kinase C (PKC) inhibited the secretion of nitric oxide, TNF alpha, and IL-1 beta from lipopolysaccharide (LPS)-stimulated macrophages, suggesting an important role for PKC in the inflammatory response. The present study was designed to investigate the mechanism whereby LPS stimulates PKC activity in inflammatory macrophages. Mouse macrophages were stimulated with 0-1 microgram/ml LPS for 0-18 hours, and PKC activity was detected in cell lysates. PKC isoform specificity was determined by blocking PKC activity with isoform-specific antibodies. Treatment of macrophages with 1 microgram/ml LPS induced a two-fold increase in PKC activity within 15 minutes and an additional more significant peak of PKC activity appeared 3 hours post-LPS stimulation. A lower dose of LPS (10 ng/ml) induced the later peak only. The enhancement in PKC activity induced by LPS occurred in both the cytosol and membrane fractions, but the enhancement in the membrane fraction was significantly greater than in the cytosol. The increase in PKC activity in both peaks was abolished only by the addition of anti-PKC-epsilon antibody. The present experiments suggest that PKC activation is an important pathway in the LPS-induced secretory response of macrophages and that PKC-epsilon is the major isoform involved.
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Affiliation(s)
- L Shapira
- Department of Periodontology, Hebrew University Hadassah Faculty of Dental Medicine, Jerusalem, Israel
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Dackiw AP, Grinstein S, Brisseau GF, McGilvray ID, Nathens AB, McGuire JA, Romanek R, Cheung PY, Rotstein OD. The role of tyrosine phosphorylation in lipopolysaccharide- and zymosan-induced procoagulant activity and tissue factor expression in macrophages. Infect Immun 1997; 65:2362-70. [PMID: 9169775 PMCID: PMC175327 DOI: 10.1128/iai.65.6.2362-2370.1997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The expression of surface procoagulants by exudative macrophages represents an important mechanism underlying local fibrin deposition at sites of extravascular inflammation. The present studies investigated the contribution of tyrosine phosphorylation to the generation of macrophage procoagulant activity (PCA) and tissue factor expression in response to proinflammatory stimuli. Both lipopolysaccharide (LPS) and zymosan rapidly stimulated tyrosine phosphorylation in elicited murine peritoneal macrophages. This effect was prevented by the tyrosine kinase inhibitors genistein and herbimycin and augmented by the addition of the phosphotyrosine phosphatase inhibitor vanadate. The vanadate-mediated rise in phosphotyrosine accumulation was abrogated by the use of diphenylene iodonium, an inhibitor of the respiratory burst oxidase, suggesting a role for peroxides of vanadate as contributors to the tyrosine phosphorylation. This notion was supported by the finding that vanadyl hydroperoxide markedly increased the accumulation of phosphotyrosine residues. To define the role of tyrosine phosphorylation in the induction of macrophage PCA by LPS, the effects of tyrosine kinase inhibition by genistein and herbimycin were investigated. Both agents inhibited the expression of macrophage PCA. Further, Northern blot analysis with the cDNA probe for murine tissue factor indicated that the inhibition occurred at the mRNA level or earlier. Since vanadate augmented phosphotyrosine accumulation, it was hypothesized that it might enhance generation of macrophage products. However, vanadate reduced induction of PCA in response to LPS. By contrast, vanadate augmented basal prostaglandin E2 (PGE2) release and stimulated PGE2 release by macrophages. Indomethacin prevented the increase in PGE2 but only partially restored normal levels of PCA. The effect of vanadate on tissue factor expression appeared to be posttranscriptional. These studies thus demonstrate, by functional Western blotting and Northern blotting techniques, that tyrosine phosphorylation plays a role in the regulation of macrophage PCA and tissue factor expression in response to proinflammatory stimuli.
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Affiliation(s)
- A P Dackiw
- Department of Surgery, Toronto Hospital and the University of Toronto, Ontario, Canada
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Saito A, Sojar HT, Genco RJ. Interleukin-1 gene expression in macrophages induced by surface protein components of Porphyromonas gingivalis: role of tyrosine kinases in signal transduction. ORAL MICROBIOLOGY AND IMMUNOLOGY 1997; 12:135-40. [PMID: 9467398 DOI: 10.1111/j.1399-302x.1997.tb00369.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We examined interleukin-beta (IL-1 beta) mRNA expression and protein tyrosine kinase activities induced by surface protein components of Porphyromonas gingivalis to gain insights into signaling pathways leading to macrophage responses. Reverse transcriptase-polymerase chain reaction analyses showed that native fimbriae, full-length recombinant fimbrillin, and a lectin-like 12-kDa antigen of P. gingivalis induced rapid expression of mRNA encoding IL-1 beta in BALB/c and lympopolysaccharide-hyporesponsive C3H/HeJ peritoneal macrophages. The antigens also specifically activated tyrosine kinase(s) in macrophages. The ability of the surface protein components to induce the cytokine mRNA accumulation was markedly abrogated by tyrosine kinase inhibitors. The findings reported here suggest that IL-1 beta expression in macrophages is a functional consequence of tyrosine kinase activation by the P. gingivalis surface protein components.
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MESH Headings
- Adhesins, Bacterial/physiology
- Animals
- Antigens, Surface/immunology
- Antigens, Surface/metabolism
- Bacterial Proteins/immunology
- Bacterial Proteins/metabolism
- Enzyme Activation/immunology
- Female
- Fimbriae Proteins
- Fimbriae, Bacterial/chemistry
- Fimbriae, Bacterial/immunology
- Interleukin-1/biosynthesis
- Interleukin-1/genetics
- Interleukin-1/immunology
- Macrophage Activation/physiology
- Macrophages, Peritoneal/enzymology
- Macrophages, Peritoneal/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Porphyromonas gingivalis/immunology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/immunology
- Protein-Tyrosine Kinases/metabolism
- RNA, Messenger/analysis
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Affiliation(s)
- A Saito
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, USA
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Wilson MA, Chou MC, Spain DA, Downard PJ, Qian Q, Cheadle WG, Garrison RN. Fluid resuscitation attenuates early cytokine mRNA expression after peritonitis. THE JOURNAL OF TRAUMA 1996; 41:622-7. [PMID: 8858019 DOI: 10.1097/00005373-199610000-00005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To study the hypothesis that fluid resuscitation alters cytokine gene expression after experimental murine peritonitis. MATERIALS AND METHODS Mice underwent cecal ligation and puncture (CLP) to induce peritonitis and were randomized to receive variable amounts of normal saline (0, 0.25, 1.0 ml. subcutaneously) and serum (0 or 0.1 mL) after operation. Hepatic and small intestinal (ileal) tissue were harvested at 3 or 6 hours after CLP, and total tissue RNA was extracted. Reverse transcriptase polymerase chain reaction was used to provide relative quantitation of tumor necrosis factor-alpha and interleukin (IL)-1 beta messenger RNA (mRNA) compared with beta-actin. RESULTS CLP without resuscitation resulted in significant increases in hepatic tumor necrosis factor-alpha mRNA (1190% at 6 hours compared with normal animals), and IL-1 beta mRNA (1475%), and intestinal IL-1 beta mRNA (1243%). Volume administration attenuated cytokine expression at both 3 and 6 hours, and saline seemed to have more potent effects than serum. The volume of resuscitation correlated with survival at 18 hours. Survival in the saline (1 mL) + serum group was 90% at 18 hours compared with 20 to 40% in the groups with little or no resuscitation. Overall, there were no survivors at 30 hours. CONCLUSIONS Fluid resuscitation (amount, composition, timing) should be an important consideration in the utilization of experimental infection models. Furthermore, optimization of the patient's intravascular volume status during sepsis may have important effects on immune responses, in addition to improving hemodynamic variables.
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Affiliation(s)
- M A Wilson
- Price Institute for Surgical Research, Department of Surgery, University of Louisville, KY 40292, USA
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Meisel C, Vogt K, Platzer C, Randow F, Liebenthal C, Volk HD. Differential regulation of monocytic tumor necrosis factor-alpha and interleukin-10 expression. Eur J Immunol 1996; 26:1580-6. [PMID: 8766564 DOI: 10.1002/eji.1830260726] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Activation of human monocytes by bacterial endotoxin (LPS) results in an initial burst of inflammatory cytokines like tumor necrosis factor (TNF)-alpha which is followed by the secretion of anti-inflammatory mediators like interleukin (IL)-10. The signaling pathways in IL-10 induction are unknown. Here, we show that the regulation of IL-10 expression is more complex than that of TNF-alpha. LPS-induced TNF-alpha and IL-10 expression requires early activation of protein tyrosine kinases (PTK). Moreover, delayed addition of PTK inhibitors blocked IL-10, but not TNF-alpha, suggesting the impact of a late PTK activity. Two inducers of PTK activity are the downstream mediators of LPS activation, TNF-alpha and cyclic adenosine monophosphate (cAMP). Both mediators synergistically up-regulate IL-10 expression. Downstream of PTK activation, they use distinct pathways. TNF-alpha, but not cAMP-induced IL-10 gene expression was inhibited by pyrrolidine dithiocarbamate, suggesting the involvement of reactive oxygen species. Inhibition of protein kinase C (PKC) suppressed LPS-induced TNF-alpha and IL-10 expression as well, but, unlike TNF-alpha, direct activation of PKC by phorbol 12-myristate 13-acetate (PMA) did not induce IL-10 expression. Furthermore, PKC is not involved in late events of IL-10 activation, as delayed addition of PKC inhibitors did not suppress LPS-induced IL-10 expression and did not influence cAMP- or TNF-alpha-induced IL-10. The modulation of IL-10 expression by inflammatory mediators suggests a regulatory circuit of the inflammatory response.
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Affiliation(s)
- C Meisel
- Institute of Medical Immunology, Medical Faculty Charité, Humboldt-University, Berlin, Germany
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Lake FR, Dempsey EC, Spahn JD, Riches DW. Involvement of protein kinase C in macrophage activation by poly(I.C). THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:C134-42. [PMID: 8304411 DOI: 10.1152/ajpcell.1994.266.1.c134] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The expression of cytocidal activity is initiated by the interaction of macrophages with priming [e.g., interferon (IFN)] and triggering stimuli (polyinosinic-polycytidylic acid). We have shown that the triggering step can be initiated in a Ca(2+)-dependent fashion and hypothesized that protein kinase C (PKC) may couple the Ca2+ signal to the expression of a gene product, Bf, that accompanies the expression of macrophage cytocidal activity. Exposure of IFN-primed macrophages to polyinosinic-polycytidylic acid in the presence of the PKC inhibitors H-7 or sphingosine or after downregulation of PKC with phorbol myristate acetate markedly inhibited Bf synthesis. Western blots of macrophage lysates revealed the presence of the alpha-, delta-, and zeta-isozymes of PKC, and all were found to be downregulated by phorbol myristate acetate. Inhibition of PKC also prevented the increase in IFN-beta mRNA levels and partially blocked the response to IFN-beta. These data suggest that the alpha-, delta-, and zeta-isozymes of PKC are involved in signaling leading to Bf expression and that the level of involvement is restricted to the induction and response to IFN-beta.
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Affiliation(s)
- F R Lake
- Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206
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Dong Z, Qi X, Fidler IJ. Tyrosine phosphorylation of mitogen-activated protein kinases is necessary for activation of murine macrophages by natural and synthetic bacterial products. J Exp Med 1993; 177:1071-7. [PMID: 8384652 PMCID: PMC2190980 DOI: 10.1084/jem.177.4.1071] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The purpose of these studies was to determine the intracellular signal transduction pathways of bacterial products in murine macrophages from lipopolysaccharide (LPS)-responder C3H/HeN and LPS-nonresponder C3H/HeJ mice. Both LPS and synthetic lipopeptide CGP 31362 (LPP) induced production of tumor necrosis factor alpha (TNF-alpha) in C3H/HeN macrophages. In C3H/HeJ macrophages, however, TNF-alpha was induced only by incubation with LPP. Both LPS and LPP induced tyrosine phosphorylation on proteins with apparent molecular masses of 39, 41, and 45 kD (p35, p41, and p45) in C3H/HeN macrophages, whereas in C3H/HeJ macrophages, tyrosine phosphorylation was induced only by LPP. 20-h incubation with LPS or LPP downregulated TNF-alpha production/secretion and tyrosine phosphorylation in C3H/HeN macrophages induced by additional LPS or LPP. In C3H/HeJ macrophages, however, the downregulation of TNF-alpha production and tyrosine phosphorylation were observed only with LPP. Protein kinase assays, Western blotting analyses, phenyl-Sepharose chromatography, and immunocomplex kinase assay suggested that p45 and p39 were similar or identical to mitogen-activated protein (MAP) kinase 1 and 2, respectively. Pretreatment of macrophages with LPS or LPP did not change the amount of kinase proteins but inhibited the stimulation of kinase activity by the agents. These data suggest that MAP kinases are among target proteins involved in the transduction of LPS and LPP signals that lead to activation of murine macrophages to produce/secrete TNF.
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Affiliation(s)
- Z Dong
- Department of Cell Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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Bethea JR, Gillespie GY, Benveniste EN. Interleukin-1 beta induction of TNF-alpha gene expression: involvement of protein kinase C. J Cell Physiol 1992; 152:264-73. [PMID: 1639861 DOI: 10.1002/jcp.1041520207] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In the human astroglioma cell line CH235-MG, interleukin-1 beta (IL-1 beta) induces transcriptional activation of the tumor necrosis factor-alpha (TNF-alpha) gene, resulting in expression of TNF-alpha mRNA and biologically active TNF-alpha protein. This study was undertaken to elucidate intracellular signaling pathways involved in IL-1 beta induction of the TNF-alpha gene. We demonstrated that the protein kinase C (PKC) activator 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA) in concert with Ca++ ionophore A23187 induced expression of TNF-alpha mRNA and protein, whereas an inactive PMA analogue (alpha PMA) had no effect. Various cyclic nucleotide activators such as 8-Bromo cAMP, cholera toxin, and forskolin had no effect on TNF-alpha production. Two PKC inhibitors, H7 and staurosporine (SS), abrogated IL-1 beta induced TNF-alpha expression in a dose-dependent fashion. Treatment of CH235-MG cells with a high concentration of PMA (1 microM) for an extended period of time (48 h) caused a greater than 90% reduction in total PKC activity. Further strengthening a role for PKC in this cytokine response is the fact that IL-1 beta was no longer able to induce TNF-alpha expression in these PKC depleted cells. Last, IL-1 beta treatment produced an increase of total PKC activity in CH235-MG cells. Taken together, these data demonstrate that IL-1 beta induces TNF-alpha gene expression in CH235-MG cells in a PKC-dependent manner.
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Affiliation(s)
- J R Bethea
- Department of Cell Biology, University of Alabama, Birmingham 35294
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12
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Vincenti MP, Burrell TA, Taffet SM. Regulation of NF-kappa B activity in murine macrophages: effect of bacterial lipopolysaccharide and phorbol ester. J Cell Physiol 1992; 150:204-13. [PMID: 1730783 DOI: 10.1002/jcp.1041500127] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nuclear factor kappa-B (NF-kappa B) has been shown to play an important role in LPS-mediated induction of several genes in macrophages. Several studies have implicated protein kinase C (PKC) or cAMP-dependent protein kinase in the regulation of NF-kappa B activity. In this study we have investigated the mechanism of NF-kappa B induction in murine macrophages. A chloramphenicol acetyl transferase (CAT) expression vector containing multiple copies of the TNF-alpha NF-kappa B element was transfected into the RAW264 macrophage-like cell line and assessed for inducible CAT activity. LPS treatment of the transfected cells resulted in a significant induction of CAT activity. CAT activity was not induced by treatment with phorbol myristate acetate (PMA) or the cAMP analogue 8-bromo cAMP. To further study NF-kappa B induction, nuclear extracts were prepared from RAW264 cells. Extracts from RAW264 cells that were treated from 30 min to 2 hr with LPS had a significant increase in NF-kappa B binding activity as determined by the electrophoresis mobility shift assay (EMSA). Treatment of these cells from 30 min to 2 hr with PMA did not result in such binding activity. U.V. crosslinking analysis of the DNA-binding activity confirmed these results and indicated that LPS induced a 55 KD DNA-binding protein. Induction of this NF-kappa B binding activity was not inhibited by pretreatment with the PKC inhibitor H-7. H-7 did inhibit induction of TPA responsive element binding by either LPS or PMA. Prolonged exposure to phorbol ester, a treatment which down-regulates PKC, had no effect on LPS induction of NF-kappa B activity in these cells. These results suggest that the induction of NF-kappa B in macrophages by LPS is independent of PKC.
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Affiliation(s)
- M P Vincenti
- Department of Microbiology and Immunology, S.U.N.Y. Health Science Center, Syracuse 13210
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