Inhibition of cyclooxygenase-2 gene expression by the heat shock response in J774 murine macrophages.
The heat shock response is a highly conserved mechanism of protection elicited in the cell by various kinds of stimuli, such as heat, sodium arsenite, oxidants and inflammation. Among the mechanisms potentially involved in mediating the protective effects of hsp, one of the most investigated is the inhibition of pro-inflammatory gene expression such as inducible nitric oxide synthase (iNOS) and inflammatory cytokines. Nevertheless, data about the effects of heat shock response on cyclooxygenase-2 expression in activated macrophages are so far not available in literature. The aim of this study was to investigate the changes in cyclooxygenase-2 expression following lipopolysaccharide stimulation of heat shocked J774 murine macrophages. We found, by Western blotting analysis and reverse transcription-polymerase chain reaction analysis (RT-PCR), that the lipopolysaccharide-induced cyclooxygenase-2 gene expression was reduced in heat shocked cells. Such a reduction was associated to activation of heat shock factor, increased levels of heat shock protein 72 and inhibition of lipopolysaccharide-induced nuclear factor-kappaB binding activity. These data suggest that the heat shock response inhibits cyclooxygenase-2 gene expression at transcriptional level, i.e. by preventing the activation of nuclear factor-kappaB, and provide additional information about mechanism(s) underlying the anti-inflammatory effect of the heat shock proteins.
Ialenti
Armando
A
Department of Experimental Pharmacology, University of Naples Federico II, Via Domenico Montesano 49, 80131 Naples, Italy.
Di Meglio
Paola
P
D'Acquisto
Fulvio
F
Pisano
Barbara
B
Maffia
Pasquale
P
Grassia
Gianluca
G
Di Rosa
Massimo
M
Ianaro
Angela
A
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D051546:Cyclooxygenase 2; D004268:DNA-Binding Proteins / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D024202:Electrophoretic Mobility Shift Assay; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D014157:Transcription Factors; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone