Induced microsomal PGE synthase-1 is involved in cyclooxygenase-2-dependent PGE2 production in gastric fibroblasts
| Autor: | Kazumasa Miyake, Yoko Shinji, Atsushi Tatsuguchi, Tetsuro Hiratsuka, Kenji Suzuki, Kei Shinoki, Choitsu Sakamoto, Seiji Futagami, Ken Wada, Taku Tsukui, Katya Gudis, Masafumi Kusunoki |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Vascular Endothelial Growth Factor A
Indoles Physiology medicine.medical_treatment Gene Expression Biology Prostaglandin E synthase Isozyme Dinoprostone Cell Line Cytosol Microsomes Physiology (medical) medicine Humans Cyclooxygenase Inhibitors Fibroblast Nitrobenzenes Prostaglandin-E synthase activity chemistry.chemical_classification Sulfonamides Cyclooxygenase 2 Inhibitors Hepatology ATP synthase Stomach Gastroenterology Membrane Proteins Fibroblasts Molecular biology Cytokine medicine.anatomical_structure Enzyme chemistry Cyclooxygenase 2 Prostaglandin-Endoperoxide Synthases Cyclooxygenase 1 biology.protein Pyrazoles lipids (amino acids peptides and proteins) Cyclooxygenase Interleukin-1 |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 288:G308-G315 |
| ISSN: | 1522-1547 0193-1857 |
| Popis: | We have previously shown that the cyclooxygenase (COX)-2/PGE2 pathway plays a key role in VEGF production in gastric fibroblasts. Recent studies have identified three PGE synthase (PGES) isozymes: cytosolic PGES (cPGES) and microsomal PGES (mPGES)-1 and -2, but little is known regarding the expression and roles of these enzymes in gastric fibroblasts. Thus we examined IL-1β-stimulated mPGES-1 and cPGES mRNA and protein expression in gastric fibroblasts by quantitative PCR and Western blot analysis, respectively, and studied both their relationship to COX-1 and -2 and their roles in PGE2 and VEGF production in vitro. IL-1β stimulated increases in both COX-2 and mPGES-1 mRNA and protein expression levels. However, COX-2 mRNA and protein expression were more rapidly induced than mPGES-1 mRNA and protein expression. Furthermore, MK-886, a nonselective mPGES-1 inhibitor, failed to inhibit IL-1β-induced PGE2 release at the 8-h time point, while totally inhibiting PGE2 at the later stage. However, MK-886 did inhibit IL-1β-stimulated PGES activity in vitro by 86.8%. N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulfonamide (NS-398), a selective COX-2 inhibitor, totally inhibited PGE2 production at both the 8-h and 24-h time points, suggesting that COX-2-dependent PGE2 generation does not depend on mPGES-1 activity at the early stage. In contrast, NS-398 did not inhibit VEGF production at 8 h, and only partially at 24 h, whereas MK-886 totally inhibited VEGF production at each time point. These results suggest that IL-1β-induced mPGES-1 protein expression preferentially coupled with COX-2 protein at late stages of PGE2 production and that IL-1β-stimulated VEGF production was totally dependent on membrane-associated proteins involved in eicosanoid and glutathione metabolism (MAPEG) superfamily proteins, which includes mPGES-1, but was partially dependent on the COX-2/PGE2 pathway. |
| Databáze: | OpenAIRE |
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