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Microsomal Prostaglandin E (microsomal + prostaglandin_e)
Selected AbstractsMicrosomal prostaglandin E synthase-1 and 5-lipoxygenase: potential drug targets in cancerJOURNAL OF INTERNAL MEDICINE, Issue 1 2010O. Rådmark Abstract., Rådmark O, Samuelsson B (Karolinska Institutet, Stockholm, Sweden). Microsomal prostaglandin Esynthase-1 and 5-lipoxygenase: potential drug targets in cancer (Review). J Intern Med 2010; 268:5,14. There is strong evidence for a role of prostaglandin (PG)E2 in cancer cell proliferation and tumour development. In PGE2 biosynthesis, cyclooxygenases (COX-1/2) convert arachidonic acid to PGH2, which can be isomerized to PGE2 by PGE synthases, including microsomal PGE synthase-1 (MPGES-1). Data describing genetic deletions of MPGES-1 are reviewed. The results suggest that MPGES-1 is an alternative therapeutic target for cancer cells and tumours that express this enzyme. Several compounds that target COX-2 or MPGES-1 also inhibit 5-lipoxygenase. This may be advantageous for treatment of some forms of cancer. [source] CREB-dependent cyclooxygenase-2 and microsomal prostaglandin E synthase-1 expression is mediated by protein kinase C and calciumJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2006Hung Pham Abstract Cellular production of prostaglandins (PGs) is controlled by the concerted actions of cyclooxygenases (COX) and terminal PG synthases on arachidonic acid in response to agonist stimulation. Recently, we showed in an ileal epithelial cell line (IEC-18), angiotensin II-induced COX-2-dependent PGI2 production through p38MAPK, and calcium mobilization (J. Biol. Chem. 280: 1582,1593, 2005). Agonist binding to the AT1 receptor results in activation of PKC activity and Ca2+ signaling but it is unclear how each pathway contributes to PG production. IEC-18 cells were stimulated with either phorbol-12,13-dibutyrate (PDB), thapsigargin (TG), or in combination. The PG production and COX-2 and PG synthase expression were measured. Surprisingly, PDB and TG produced PGE2 but not PGI2. This corresponded to induction of COX-2 and mPGES-1 mRNA and protein. PGIS mRNA and protein levels did not change. Activation of PKC by PDB resulted in the activation of ERK1/2, JNK, and CREB whereas activation of Ca2+ signaling by TG resulted in the delayed activation of ERK1/2. The combined effect of PKC and Ca2+ signaling were prolonged COX-2 and mPGES-1 mRNA and protein expression. Inhibition of PKC activity, MEK activity, or Ca2+ signaling blocked agonist induction of COX-2 and mPGES-1. Expression of a dominant negative CREB (S133A) blocked PDB/TG-dependent induction of both COX-2 and mPGES-1 promoters. Decreased CREB expression by siRNA blocked PDB/TG-dependent expression of COX-2 and mPGES-1 mRNA. These findings demonstrate a coordinated induction of COX-2 and mPGES-1 by PDB/TG that proceeds through PKC/ERK and Ca2+ signaling cascades, resulting in increased PGE2 production. J. Cell. Biochem. © 2006 Wiley-Liss, Inc. [source] Triclosan reduces microsomal prostaglandin E synthase-1 expression in human gingival fibroblastsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2005M. Mustafa Abstract Objective: The effect of triclosan (2,4,4,-trichloro-2,-hydroxydiphenyl ether) on the expression of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) and on the translocation of the nuclear factor- ,B (NF- ,B) in relation to prostaglandin E2 (PGE2) production was investigated in human gingival fibroblasts challenged with tumor necrosis factor , (TNF,). Methods: Fibroblasts were established from gingival biopsies obtained from six children. COX-2 mRNA and protein expression was quantified using mRNA quantitation and enzyme immunometric assay kits. mPGES-1 mRNA was analysed by RT-PCR, mPGES-1 protein and NF-,B translocation by immunoblotting. PGE2 was determined by radioimmunoassay. Results: The cytokine TNF, enhanced the expression of mRNA as well as the protein levels of both COX-2 and mPGES-1 and subsequently the production of PGE2 in gingival fibroblasts. Treatment of gingival fibroblasts with triclosan (1 ,g/ml) significantly reduced the stimulatory effect of TNF, (10 ng/ml) on the expression of mPGES-1 at both the mRNA and the protein level by an average of 21% and 43%, respectively, and subsequently the production of PGE2 (p<0.01). Triclosan did not, however, affect the translocation of NF- ,B or the expression of COX-2 in TNF,- stimulated cells. Conclusion: The results show that triclosan reduces the augmented biosynthesis of PGE2 by inhibiting the mRNA and the protein expression of mPGES-1 in gingival fibroblasts. This finding may partly explain the anti-inflammatory effect of the agent previously reported in clinical studies. [source] Detection of fascin and CCR-7 positive mature dendritic cells in oral lichen planusJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 4 2009Shotaro Mukae Background:, Dendritic cells (DC) play a crucial role in the pathogenesis of oral lichen planus (OLP) with respect to antigens presented to T cells. We performed immunohistochemical analysis to elucidate the process of activation of DC in OLP. Methods:, Thirty biopsy specimens were obtained from the patients with OLP. The expressions of CD1a, Langerin, S-100, fascin, chemokine receptor-7 (CCR-7), D2-40, cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1) in DC from OLP and disease free control were investigated using specific antibodies. The distribution and number (1 mm2) of DC were assessed in the intra-epithelium and the submucosa specimens. Correlation between the number of DC and epithelium thickness was also determined. Result:, Immature DC (Langerin+, CD1a+, and S-100+) were identified in the epithelia from OLP patients and control, though the numbers of Langerin+ and CD1a+ positive cells were decreased in the OLP samples as compared to the control. Mature DC (fascin+) were identified in the submucosa specimens, not found in the epithelium from OLP or control. Double immunostaining revealed DC positive for fascin and CCR-7 in the submucosa, which had migrated into D2-40+ lymph vessels. Furthermore, keratinocytes expressed both Prostaglandin E2 (PGE2) converting enzymes, COX-2, and mPGES-1, indicating PGE2 synthesis in the epithelial layer of the OLP specimens. Conclusion:, Our results indicate that DC change from immature to mature in the epithelium and are then drawn out to the submucosa. We demonstrate that mature DC localized in the submucosa, it consequently migrates into lymph vessels. This maturation process of DC is an important immunopathological feature of OLP. [source] | ||||||||||