- Oral presentation
- Open Access
Transcriptional regulation of the mPGES-1 gene in primary cultured articular chondrocytes
Arthritis Res Ther volume 6, Article number: 10 (2004)
Healthy cartilage is maintained in a state of dynamic equilibrium by matrix synthesis and matrix degradation by the chondrocytes. Any dysregulation with increased degradation and/or inadequate synthesis leads to the loss of tissue structure and function, as in rheumatoid arthritis and osteoarthritis. The proinflammatory cytokine IL-1 plays a major role in this phenomenon. IL-1 acts on chondrocytes in part by stimulating the release of prostaglandin E2 (PGE2) at the sites of inflammation. Recently, a human membrane-associated prostaglandin E2 synthase-1 (mPGES-1) was cloned. This enzyme catalyzes the conversion of prostaglandin H2 to PGE2 in a highly specific manner. We previously demonstrated that mPGES-1 mRNA is induced by IL-1 in chondrocytes in a dose-dependent and time-dependent manner.
In order to study the transcriptional regulation of mPGES-1 in primary rabbit articular chondrocytes, we have cloned its promoter upstream of the CAT ORF (vector pCAT3-basic; Promega, Charbonnièresles-Bains, France). We show by transient transfection experiments that the mPGES-1 promoter is stimulated by IL-1. A close examination of putative binding sites has revealed the presence of two CCAAT/Enhancer Binding Protein (C/EBP) binding sequences (TTNNGNAAT) located between -548 to -558 base pairs and -610 to -619 base pairs. Co-transfections of expression vectors encoding the two different isoforms of C/EBP (β and δ) strongly stimulate the promoter activity. To further study the role of C/EBP in mPGES-1 expression, we performed gel shift experiments on wild-type and mutated oligonucleotides derived from the mPGES-1 sequence. These experiments confirm the specific binding of C/EBP on the mPGES-1 promoter. Taken together, our results suggest that C/EBP factors indeed bind and regulate the mPGES promoter in articular chondrocytes.
About this article
Cite this article
Bausero, P., Salvat, C., de Salinelles, V.M. et al. Transcriptional regulation of the mPGES-1 gene in primary cultured articular chondrocytes. Arthritis Res Ther 6, 10 (2004). https://doi.org/10.1186/ar1344
- Rheumatoid Arthritis
- Articular Chondrocytes
- Transfection Experiment
- Primary Rabbit