Inhibition of LPS-induced C/EBP delta by trichostatin A has a positive effect on LPS-induced cyclooxygenase 2 expression in RAW264.7 cells.
Cyclooxygenase 2 (COX-2) is an important inflammatory factor. Previous studies have indicated that COX-2 is induced with lipopolysaccharide (LPS) treatment. Here, we found that an inhibitor of histone deacetylase (HDAC), trichostatin A (TSA), cannot repress LPS-induced COX-2 but it increased the COX-2 level in RAW264.7 cells. We found no significant difference in NF-kappaB activation and ERK1/2 phosphorylation, but LPS-induced C/EBP delta expression was completely abolished after TSA treatment of LPS-treated cells. Interesting, reporter assay of C/EBP delta promoter revealed that Sp1-binding site is important. Although there was no alteration in c-Jun levels, but the phosphorylation of c-Jun at its C-terminus was increased dramatically. A DNA-associated protein assay (DAPA) and chromatin immunoprecipitation assay (ChIP) indicated that c-Jun was recruited via Sp1 to the promoter of C/EBP delta after LPS treatment; this recruitment of c-Jun was repressed by TSA. C/EBP delta inhibition by TSA resulted in increased binding of C/EBP alpha and C/EBP beta to the COX-2 promoter. Therefore, TSA has a positive effect on LPS-induced COX-2 since it decreases the C/EBP delta level by reducing c-Jun recruitment by Sp1 to the C/EBP delta promoter, resulting in increased the recruitment of C/EBP alpha and C/EBP beta to the COX-2 promoter.
Liu
Yi-Wen
YW
College of Life Science, Graduate Institute of Biopharmaceutics, National Chiayi University, Chiayi 600, Taiwan.
Wang
Shao-An
SA
Hsu
Tsung-Yi
TY
Chen
Tsu-An
TA
Chang
Wen-Chang
WC
Hung
Jan-Jong
JJ
D000818:Animals; D015153:Blotting, Western; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000235:genetics / Q000378:metabolism; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics / Q000378:metabolism; D051743:CCAAT-Enhancer-Binding Protein-delta / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006877:Hydroxamic Acids / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction
D022763:CCAAT-Enhancer-Binding Protein-alpha; D022782:CCAAT-Enhancer-Binding Protein-beta; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D008070:Lipopolysaccharides; D016328:NF-kappa B; D051743:CCAAT-Enhancer-Binding Protein-delta; C012589:trichostatin A; D051546:Cyclooxygenase 2