Signal pathways JNK and NF-[kappa]B, identified by global gene expression profiling, are involved in regulation of TNF[alpha]-induced mPGES-1 and COX-2 expression in gingival fibroblasts

• Published in: BMC genomics Vol. 11; pp. 241 - 481
• Main Authors: Båge, Tove, Lindberg, Johan, Lundeberg, Joakim, Modéer, Thomas, Yucel-Lindberg, Tülay
• Format: Journal Article
• Language: English
• Published: BioMed Central Ltd 15.04.2010
• Subjects: Cellular signal transduction; Genetic aspects; Health aspects; Periodontitis; Physiological aspects; Risk factors; Transcription factors; Tumor necrosis factor; Sweden
• ISSN: 1471-2164; 1471-2164
• DOI: 10.1186/1471-2164-11-241

Prostaglandin E.sub.2 (PGE.sub.2 ) is involved in several chronic inflammatory diseases including periodontitis, which causes loss of the gingival tissue and alveolar bone supporting the teeth. We have previously shown that tumor necrosis factor [alpha] (TNF[alpha]) induces PGE.sub.2 synthesis in gingival fibroblasts. In this study we aimed to investigate the global gene expression profile of TNF[alpha]-stimulated primary human gingival fibroblasts, focusing on signal pathways related to the PGE.sub.2 -synthesizing enzymes prostaglandin E synthases (PGES), as well as the upstream enzyme cyclooxygenase-2 (COX-2) and PGE.sub.2 production. Microarray and western blot analyses showed that the mRNA and protein expression of the inflammatory induced microsomal prostaglandin E synthase-1 (mPGES-1) was up-regulated by the cytokine TNF[alpha], accompanied by enhanced expression of COX-2 and increased production of PGE.sub.2 . In contrast, the expression of the isoenzymes microsomal prostaglandin E synthase-2 (mPGES-2) and cytosolic prostaglandin E synthase (cPGES) was unaffected by TNF[alpha] treatment. Using oligonucleotide microarray analysis in a time-course factorial design including time points 1, 3 and 6 h, differentially expressed genes in response to TNF[alpha] treatment were identified. Enrichment analysis of microarray data indicated two positively regulated signal transduction pathways: c-Jun N-terminal kinase (JNK) and Nuclear Factor-[kappa]B (NF-[kappa]B). To evaluate their involvement in the regulation of mPGES-1 and COX-2 expression, we used specific inhibitors as well as phosphorylation analysis. Phosphorylation analysis of JNK (T183/Y185) and NF-[kappa]B p65 (S536) showed increased phosphorylation in response to TNF[alpha] treatment, which was decreased by specific inhibitors of JNK (SP600125) and NF-[kappa]B (Bay 11-7082, Ro 106-9920). Inhibitors of JNK and NF-[kappa]B also decreased the TNF[alpha]-stimulated up-regulation of mPGES-1 and COX-2 as well as PGE.sub.2 production. In the global gene expression profile, the enrichment analysis of microarray data identified the two signal transduction pathways JNK and NF-[kappa]B as positively regulated by the cytokine TNF[alpha]. Inhibition of these TNF[alpha]-activated signal pathways reduced the expression of mPGES-1 and COX-2 as well as their end product PGE.sub.2 in gingival fibroblasts. The involvement of the signal pathways JNK and NF-[kappa]B in the regulation of PGE.sub.2 induced by TNF[alpha] may suggest these two pathways as possible attractive targets in the chronic inflammatory disease periodontitis.