scholarly journals Delayed Treatment with Isoflurane Attenuates Lipopolysaccharide and Interferon γ–induced Activation and Injury of Mouse Microglial Cells

2009 ◽  
Vol 111 (3) ◽  
pp. 566-573 ◽  
Author(s):  
Jie-Ae Kim ◽  
Liaoliao Li ◽  
Zhiyi Zuo
Keyword(s):  
Protein Kinase C ◽  
Lactate Dehydrogenase ◽  
Protein Kinase ◽  
Cell Viability ◽  
Inos Expression ◽  
Microglial Cells ◽  
Lactate Dehydrogenase Release ◽  
Kinase C ◽  
Nitrite Production ◽  
Isoflurane Treatment

Background Isoflurane pretreatment can induce protection against lipopolysaccharide and interferon gamma (IFNgamma)-induced injury and activation of mouse microglial cells. This study's goal was to determine whether delayed isoflurane treatment is protective. Methods Mouse microglial cells were exposed to various concentrations of isoflurane for 1 h immediately after the initiation of lipopolysaccharide (10 or 1000 ng/ml) and IFNgamma (10 U/ml) stimulation or to 2% isoflurane for 1 h at various times after initiation of the stimulation. Nitrite production, lactate dehydrogenase release, and cell viability measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay were assessed after stimulation with lipopolysaccharide and IFNgamma for 24 h. Inducible nitric oxide synthase (iNOS) protein expression was quantified by Western blotting. The iNOS expression in mouse brain was also studied. Results Isoflurane applied 0 and 2 h after the initiation of lipopolysaccharide and IFNgamma stimulation improved cell viability. Isoflurane at 2%, but not at 1 or 3%, reduced the lipopolysaccharide and IFNgamma-induced nitrite production and decreased cell viability. Aminoguanidine, an iNOS inhibitor, also attenuated this decreased cell viability. Chelerythrine and bisindolylmalemide IX, protein kinase C inhibitors, abolished isoflurane effects on cell viability and iNOS expression after lipopolysaccharide and IFNgamma application. Isoflurane also decreased lipopolysaccharide-induced iNOS expression in mouse brain. Late isoflurane application to microglial cells reduced lipopolysaccharide and IFNgamma-induced lactate dehydrogenase release that was not inhibited by aminoguanidine. Conclusions These results suggest that delayed isoflurane treatment can reduce lipopolysaccharide and IFNgamma-induced activation and injury of microglial cells. These effects may be mediated by protein kinase C.

scholarly journals Possible role of protein kinase C-ε isoenzyme in inhibition of interleukin 1β induction of nitric oxide synthase in rat renal mesangial cells

1994 ◽  
Vol 303 (2) ◽  
pp. 607-612 ◽  
Author(s):  
H Mühl ◽  
J Pfeilschifter
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nitric Oxide Synthase ◽  
Phorbol Ester ◽  
Mesangial Cells ◽  
Inos Expression ◽  
Kinase C ◽  
Nitrite Production ◽  
Oxide Synthase

In cultured glomerular mesangial cells, interleukin 1 beta (IL-1 beta) has been shown to induce a dose- and time-dependent accumulation of nitrite, a stable metabolite of nitric oxide (NO). In parallel, increased levels of mRNA of an inducible macrophage-type of nitric oxide synthase (iNOS) were observed after incubating mesangial cells with IL-1 beta. Here we report that addition of the biologically active phorbol esters, phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu), dose-dependently inhibited the IL-1 beta-stimulated increase in iNOS mRNA levels and nitrite production. In contrast, the biologically inactive phorbol ester 4 alpha-phorbol 12,13-didecanoate, had no effect on cytokine induction of iNOS and nitrite formation. Incubation of mesangial cells with PMA or PDBu alone, in the absence of IL-1 beta, did not trigger any iNOS expression. Time-course studies indicated that phorbol ester needs to be added for only 1 h in order to maximally inhibit cytokine-induced nitrite production. Down-regulation of protein kinase C (PKC)-alpha and -delta isoenzymes by 8 h PMA or PDBu treatment before stimulation with IL-1 beta still resulted in full inhibition of iNOS induction. In contrast, a 24 h treatment of mesangial cells with PMA or PDBu, a regimen that also causes depletion of PKC-epsilon, abolished inhibition of IL-1 beta-induced iNOS expression and nitrite production. In addition, the selective PKC inhibitor calphostin C potentiated IL-1 beta induction of iNOS activity. In summary these data suggest that IL-1 beta induction of iNOS expression is tonically suppressed by PKC and the epsilon-isoenzyme is the most likely candidate mediating this effect.

Targeting protein kinase C by Enzastaurin restrains proliferation and secretion in human pancreatic endocrine tumors

2011 ◽  
Vol 18 (4) ◽  
pp. 439-450 ◽  
Author(s):  
Daniela Molè ◽  
Teresa Gagliano ◽  
Erica Gentilin ◽  
Federico Tagliati ◽  
Claudio Pasquali ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase C ◽  
Insulin Secretion ◽  
Protein Kinase ◽  
Cell Viability ◽  
Cell Line ◽  
Primary Cultures ◽  
Endocrine Tumors ◽  
Kinase C ◽  
Pancreatic Endocrine Tumors

Dysregulation of the protein kinase C (PKC) signaling pathway has been implicated in tumor progression. In this study, we investigate the effects of a PKC inhibitor, Enzastaurin, in human pancreatic neuroendocrine neoplasms (PNN) primary cultures and in the human pancreatic endocrine cancer cell line, BON1. To this aim six human PNN dispersed in primary cultures and BON1 cells were treated without or with 1–10 μM Enzastaurin and/or 100 nM IGF1 in the presence or absence of serum. Cell viability and apoptosis were evaluated after 48–72 h; Chromogranin A (CgA) and/or insulin secretion was assessed after 6 h of incubation. PKC expression was investigated by immunofluorescence and western blot. We found that Enzastaurin significantly reduced human PNN primary culture cell viability, as well as CgA and insulin secretion. Moreover, in the BON1 cell line Enzastaurin inhibited cell proliferation at 5 and 10 μM by inducing caspase-mediated apoptosis, and reduced phosphorylation of glycogen synthetase kinase 3β (GSK3β) and of Akt, both downstream targets of PKC pathway and pharmacodynamic markers for Enzastaurin. In addition, Enzastaurin blocked the stimulatory effect of IGF1 on cell proliferation, and reduced CgA expression and secretion in BON1 cells. Two different PKC isoforms are expressed at different levels and have partially different subcellular localization in BON1 cells. In conclusion, Enzastaurin reduces cell proliferation by inducing apoptosis, with a mechanism likely involving GSK3β signaling, and inhibits secretory activity in PNN in vitro models, suggesting that Enzastaurin might represent a possible medical treatment of human PNN.

scholarly journals Isoflurane Preconditioning Reduces the Rat NR8383 Macrophage Injury Induced by Lipopolysaccharide and Interferon γ

2008 ◽  
Vol 108 (4) ◽  
pp. 643-650 ◽  
Author(s):  
Xuebing Xu ◽  
Jifeng Feng ◽  
Zhiyi Zuo
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nitric Oxide Synthase ◽  
Cell Viability ◽  
Interferon Gamma ◽  
Inducible Nitric Oxide Synthase ◽  
Kinase C ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background Isoflurane exposure before an insult can reduce the insult-induced injury in various organs. This phenomenon is called isoflurane preconditioning. The authors hypothesize that isoflurane can precondition macrophages, cells that travel to all tissues and are important in the host defense and inflammation responses. Methods Rat NR8383 macrophages were pretreated with or without 1-3% isoflurane for 1 h at 30 min before they were incubated with or without 100 ng/ml lipopolysaccharide plus 50 U/ml interferon gamma for 24 h. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry was performed after cells were stained with annexin V and propidium iodide. Inducible nitric oxide synthase protein expression in macrophages was quantified by Western blotting. Results Lipopolysaccharide plus interferon gamma decreased cell viability by approximately 50%. This decrease was dose-dependently inhibited by aminoguanidine, an inducible nitric oxide synthase inhibitor. Lipopolysaccharide plus interferon gamma caused inducible nitric oxide synthase expression. This expression was inhibited by pretreatment with 2% but not 1% or 3% isoflurane. Isoflurane at 2% inhibited lipopolysaccharide plus interferon gamma-induced accumulation of nitrite, an oxidation product of nitric oxide. Pretreatment with 2% but not 1% or 3% isoflurane improved cell viability. Lipopolysaccharide plus interferon gamma increased the number of propidium iodide-positive staining cells. This increase was attenuated by 2% isoflurane pretreatment. The protective effect of 2% isoflurane was abolished by chelerythrine, calphostin C, or bisindolylmaleimide IX, protein kinase C inhibitors. Conclusions Lipopolysaccharide plus interferon gamma causes an inducible nitric oxide synthase-dependent macrophage injury. Isoflurane induces preconditioning effects that may be mediated by protein kinase C in macrophages.

Action of protein kinase C in endothelin-induced contractions in rat aortic rings

1996 ◽  
Vol 271 (1) ◽  
pp. C398-C404 ◽  
Author(s):  
G. K. Oriji ◽  
H. R. Keiser
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nitric Oxide Release ◽  
Kinase C ◽  
Nitrite Production ◽  
Pkc Inhibitors ◽  
Potent Vasoconstrictor ◽  
Nitrate And Nitrite ◽  
Oxide Synthase

Endothelin (ET) is a potent vasoconstrictor peptide that induces characteristically long-lasting contractions. We used both intact and endothelium-denuded rat aortic rings to investigate the role of protein kinase C (PKC) in ET-induced contractions. ET (10(-9) M) and phorbol 12,13-dibutyrate (PDBu), a PKC activator, produced a gradual and sustained contraction of greater magnitude in denuded aortic rings than in intact rings. When aortic rings were pretreated with graded concentrations of different PKC inhibitors, inhibition of ET-induced contractions began at 10(-9)M and was nearly complete at 10(-3)M, and the reduction was greater in intact than in denuded rings. Pretreatment of aortic rings with PDBu or NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, potentiated ET-induced contractions. PKC enzyme assay showed activation of PKC in aortic rings that were treated with either ET or PDBu, inhibition after pretreatment with PKC inhibitors, and no change with 4 alpha-phorbol 12,13-didecanoate (PDD), an inactive phorbol ester. ET significantly increased nitrate and nitrite production, which was further increased by pretreatment with PKC inhibitors. PDBu prevented ET-induced nitrate/nitrite production, and PDD had no effect. These results strongly suggest that PKC mediates, in part, ET-induced contractions in rat aortic rings and that an intact endothelium is required for maximum inhibition by PKC inhibitors because PKC stimulated by ET inhibits nitric oxide release.

scholarly journals Cannabinoid CB2 Receptor Mediates Nicotine-Induced Anti-Inflammation in N9 Microglial Cells Exposed toβAmyloid via Protein Kinase C

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ji Jia ◽  
Jie Peng ◽  
Zhaoju Li ◽  
Youping Wu ◽  
Qunlin Wu ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Microglial Activation ◽  
Microglial Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cb2 Receptor ◽  
Arginase 1 ◽  
Kinase C ◽  
Activated State ◽  
Anti Inflammation

Background. Reducingβamyloid- (Aβ-) induced microglial activation is considered to be effective in treating Alzheimer’s disease (AD). Nicotine attenuates Aβ-induced microglial activation; the mechanism, however, is still elusive. Microglia could be activated into classic activated state (M1 state) or alternative activated state (M2 state); the former is cytotoxic and the latter is neurotrophic. In this investigation, we hypothesized that nicotine attenuates Aβ-induced microglial activation by shifting microglial M1 to M2 state, and cannabinoid CB2 receptor and protein kinase C mediate the process.Methods. We used Aβ1–42 to activate N9 microglial cells and observed nicotine-induced effects on microglial M1 and M2 biomarkers by using western blot, immunocytochemistry, and enzyme-linked immunosorbent assay (ELISA).Results. We found that nicotine reduced the levels of M1 state markers, including inducible nitric oxide synthase (iNOS) expression and tumor necrosis factorα(TNF-α) and interleukin- (IL-) 6 releases; meanwhile, it increased the levels of M2 state markers, including arginase-1 (Arg-1) expression and brain-derived neurotrophic factor (BDNF) release, in the Aβ-stimulated microglia. Coadministration of cannabinoid CB2 receptor antagonist or protein kinase C (PKC) inhibitor partially abolished the nicotine-induced effects.Conclusion. These findings indicated that cannabinoid CB2 receptor mediates nicotine-induced anti-inflammation in microglia exposed to Aβvia PKC.

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