- 作者: Yu-Chiuan Huang; Wen-Chang Chang; Jyan-Gwo J. Su; Jheng-Liang Cai; Chun-Chia Chen; Jan-Jong Hung; Yi-Wen Liu
- 作者服務機構: 1 Graduate Institute of Biopharmaceutics, College of Life Sciences, National Chiayi University, Chiayi, 600, Taiwan; ; 2 Department of Pharmacology, College of Medicine, and Center for Gene Regulation and Signal Transduction Research, National Cheng Kung University, Tainan, 701, Taiwan; ; 3 Institute of Biotechnology, College of Life Sciences, National Chiayi University, Chiayi, 600, Taiwan
- 中文摘要: --
- 英文摘要: Peptidoglycan-activated gene expression is mediated through various transcription factors including CCAAT/enhancer-binding protein δ (C/EBPδ). The purpose of the present study is to elucidate the mechanism of PGN-activated C/EBPδ gene. PGN stimulated C/EBPδ protein and mRNA expression in mouse macrophages RAW 264.7 cells. Analysis of C/EBPδ promoter activity by luciferase reporter assay indicated that PGN-induced C/EBPδ gene activation is partially mediated by the -345 to +24 bp of C/EBPδ gene promoter. The in vitro protein-DNA binding assay showed that Sp1, c-Rel and c-Jun are the major protein binding to this PGN-response element of C/EBPδ promoter, and the binding of c-Rel and c-Jun is increased after PGN treatment. All of these binding activities were abolished when Sp1-, NF-κΒ/ APRE-, CRE-sites were mutated. Furthermore, analysis of this promoter region by site-directed mutants constructed in luciferase reporter vector indicated that two Sp1-sites, one NF-κB/APRE-site and one CRE-site are prominent for PGN-induced gene expression. In addition, when Sp1, c-Rel or c-Jun transcription factors were overexpressed in cells, all of them enhanced C/EBPδ promoter activity. In summary, we suggest that Sp1, c-Rel and c-Jun transcription factors play important roles in activation of C/EBPδ gene promoter under the stimulation of PGN. Given the importance of C/EBPδ in inflammatory disease, these results reveal a clue as a potential therapeutic target for suppression of C/EBPδ expression under PGN stimulation.
- 中文關鍵字: --
- 英文關鍵字: macrophages, C/EBPδ, Sp 1, c-Rel, c-Jun, peptidoglycan