Abstract
1 In this study, we examined the role of Ca2+ in linking proteinase-activated receptor-2 (PAR2) to the nuclear factor kappa B (NFkappaB) pathway in a skin epithelial cell line NCTC2544 stably expressing PAR2 (clone G). 2 In clone G, PAR2-mediated NFkappaB luciferase reporter activity and NFkappaB DNA-binding activity was reduced by preincubation with BAPTA-AM but not BAPTA. Trypsin stimulation of inhibitory kappa B kinases, IKKalpha and IKKbeta, was also inhibited following pretreatment with BAPTA-AM. 3 BAPTA/AM also prevented PAR2-mediated IKKalpha activation in cultured primary human keratinocytes. 4 The effect of BAPTA-AM was also selective for the IKK/NFkappaB signalling axis; PAR2 coupling to ERK, or p38 MAP kinase was unaffected. 5 Pharmacological inhibition of the Ca2+-dependent regulatory protein calcineurin did not inhibit trypsin-stimulated IKK activity or NFkappaB-DNA binding; however, inhibition of Ca2+-dependent protein kinase C isoforms or InsP3 formation using GF109203X or the phospholipase C inhibitor U73122, respectively, reduced both IKK activity and NFkappaB-DNA binding. 6 Mutation of PAR2 within the C-terminal to produce a mutant receptor, which does not couple to Ca2+ signalling, but is able to activate ERK, abrogated NFkappaB-DNA binding and IKK activity stimulated by trypsin. 7 These results suggest a predominant role for the InsP3/Ca2+ axis in the regulation of IKK signalling and NFkappaB transcriptional activation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / analogs & derivatives
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
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Calcium / physiology*
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Cell Line
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Chelating Agents / pharmacology
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Egtazic Acid / analogs & derivatives
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Egtazic Acid / pharmacology
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Enzyme Inhibitors / pharmacology
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Estrenes / pharmacology
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Humans
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I-kappa B Kinase
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Indoles / pharmacology
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Keratinocytes / cytology
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Keratinocytes / drug effects
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Keratinocytes / physiology*
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Maleimides / pharmacology
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Mitogen-Activated Protein Kinases / metabolism
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NF-kappa B / genetics
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NF-kappa B / metabolism
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NF-kappa B / physiology*
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Oligonucleotides / metabolism
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Phosphodiesterase Inhibitors / pharmacology
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Protein Binding / drug effects
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Protein Kinase C / antagonists & inhibitors
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Protein Kinase C / metabolism
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Protein Serine-Threonine Kinases / metabolism
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Pyrrolidinones / pharmacology
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Receptor, PAR-2 / genetics
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Receptor, PAR-2 / metabolism
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Receptor, PAR-2 / physiology*
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Signal Transduction / drug effects
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Signal Transduction / physiology*
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Tacrolimus / pharmacology
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Tetradecanoylphorbol Acetate / pharmacology
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Trypsin / pharmacology
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Type C Phospholipases / antagonists & inhibitors
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Type C Phospholipases / metabolism
Substances
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Chelating Agents
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Enzyme Inhibitors
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Estrenes
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Indoles
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Maleimides
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NF-kappa B
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Oligonucleotides
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Phosphodiesterase Inhibitors
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Pyrrolidinones
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Receptor, PAR-2
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1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
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1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester
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Egtazic Acid
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KN 62
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Protein Serine-Threonine Kinases
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CHUK protein, human
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I-kappa B Kinase
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IKBKB protein, human
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IKBKE protein, human
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Protein Kinase C
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Mitogen-Activated Protein Kinases
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Type C Phospholipases
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Trypsin
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1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
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bisindolylmaleimide I
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Tetradecanoylphorbol Acetate
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Calcium
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Tacrolimus