Effects of recombinant interleukin-1 beta on decorin gene expression in human periodontal ligament fibroblast and its possible transcriptional regulation.
Interleukin-1 beta (IL-1 beta) is a potent regulator of osteoprogenitor cells and fibroblasts, and is believed to be responsible for the bone loss and connective tissue breakdown that occurs in periodontitis. Decorin, a major small proteoglycan in the periodontium, has been shown as an important mediator of the organization of the pericellular and extracellular matrix. Since the HPLF play a significant role in the regulation of extracellular matrix metabolism, it was important to clarify the causal relationship between cytokines, HPLF and proteoglycans. We investigated the effect of IL-1 beta on decorin gene expression and its functional regulation to elucidate the intracellular mechanism mediating the action of IL-1 beta. Quiescently confluent HPLF cultures were incubated for different treatment periods with various concentrations of IL-1 beta and/or 10(-4) M cycloheximide (Cx) in culture medium supplemented with 1% charcoal-stripped serum for different treatment periods. Northern hybridization analyses, using decorin cDNA probe, showed that IL-1 beta increased the abundance of decorin mRNA in both a dose- and time-dependent manner. Most of the stimulation was blocked by Cx, indicating that the regulation of decorin gene expression by IL-1 beta may be via an indirect pathway, requiring new protein synthesis which regulates the promoter. Gel mobility shift analyses detected the specific DNA binding activity of a nuclear extract of AP-1, but not NF-kappa B, that could bind to the recognition site of decorin gene promoter fragments with the increased abundance in IL-1 beta treatment groups. These results suggest that the increased transcription of decorin gene by HPLF in the presence of IL-1 beta is mediated at least in part through the interaction of AP-1 with the decorin gene promoter.
Lin
J M
JM
Department of Orthodontics, Kanagawa Dental College, Japan.
Yamauchi
M
M
Sato
S
S
D016301:Alveolar Bone Loss / Q000503:physiopathology; D015152:Blotting, Northern; D002478:Cells, Cultured; D003238:Connective Tissue / Q000503:physiopathology; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D015342:DNA Probes; D018076:DNA, Complementary; D058575:Decorin; D004305:Dose-Response Relationship, Drug; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins; D005347:Fibroblasts / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology* / Q000502:physiology; D016328:NF-kappa B / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D010012:Osteogenesis; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D010518:Periodontitis / Q000503:physiopathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011509:Proteoglycans / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
C546878:DCN protein, human; D015342:DNA Probes; D018076:DNA, Complementary; D058575:Decorin; D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D016328:NF-kappa B; D011500:Protein Synthesis Inhibitors; D011509:Proteoglycans; D012333:RNA, Messenger; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D004247:DNA; D003513:Cycloheximide