Role of NF-B in TNF--induced COX-2 Expression in Synovial Fibroblasts from Human TMJ

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http://jdr.iadrjournals.org/cgi/content/abstract/86/4/363?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=TMJ&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT

Role of NF-B in TNF--induced COX-2 Expression in Synovial Fibroblasts from Human TMJ
Journal of Dental Research 86(4):363-367, 2007

J. Ke1, X. Long1,2,*, Y. Liu3, Y.F. Zhang4, J. Li2, W. Fang2, and Q.G. Meng2
1 Key Lab. for Oral Biomedical Engineering, Ministry of Education,
2 Departments of Oral Maxillofacial Surgery and
4 Prosthodontics, School & Hospital of Stomatology,
3 Department of Radio-Chemotherapy of Zhongnan Hospital, Wuhan University, Wuhan 430079, PR China

* corresponding author, longxing_china@hotmail.com

In the temporomandibular joint (TMJ) synovium, cyclo-oxygenase-2 (COX-2) expression has been believed to be directly related to joint pain and synovitis. Here we investigated the role of Nuclear Factor B (NF-B) in the regulation of COX-2 expression in synovial fibroblasts from human TMJ induced by tumor necrosis factor- (TNF-). By reverse-transcriptase/polymerase chain-reaction (RT-PCR) and Western blotting analysis, TNF- induced a dose- and time-dependent increase in COX-2 expression. Electrophoretic mobility shift assay (EMSA) revealed that transient NF-B activation in the COX-2 promoter was triggered by TNF-. In parallel with transient NF-B activation, the rapid translocation of NF-B, particularly the p65 subunit, from the cytoplasm into the nucleus was demonstrated. Pre-treatment with pyrolidine dithiocarbamate (PDTC), one of the NF-B inhibitors, prevented binding to the COX-2 promoter and expression of COX-2 protein in response to TNF-. These findings indicate that activation of NF-B is responsible for TNF--induced COX-2 expression in synovial fibroblasts from the TMJ.

KEY WORDS: TMJ Ô COX-2 Ô NF-B Ô TNF- Ô synovial fibroblasts

© 2007 International and American Associations for Dental Research