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Prostaglandin E 2 (PGE 2 ) plays pivotal roles in controlling microglial activation with the EP 2 receptor, a PGE 2 receptor subtype. Activated microglia are often reported to increase cyclooxygenase (COX)-2 expression, followed by PGE 2 production, but it is unclear whether extracellular PGE 2 is involved in microglial PGE 2 synthesis. In the present study, we report that PGE 2 increases COX-2 protein in microglia. In a culture system, PGE 2 at 10 -6 M for 3 h increased COX-2 and microsomal PGE synthase (mPGES)-1 mRNA levels, and reduced mPGES-2, but did not affect COX-1 or cytosolic PGE synthase (cPGES) in microglia. PGE 2 at 10 -6 M for 3 h also increased the COX-2 protein level, but did not affect COX-1, mPGES-1, mPGES-2, or cPGES. An EP 2 agonist, ONO-AE1-259-01, also increased COX-2 and mPGES-1 mRNA levels, and reduced mPGES-2, but did not affect COX-1 or cPGES, whereas an EP 1 agonist, ONO-DI-004, an EP 3 agonist, ONO-AE-248, and an EP 4 agonist, ONO-AE1-329, had no effect. Similar to PGE 2 , ONO-AE1-259-01 increased the COX-2 protein level, but did not affect COX-1, mPGES-1, mPGES-2, or cPGES. In addition, the effects of PGE 2 were inhibited by an EP 2 antagonist, PF-04418948, but not by an EP 1 antagonist, ONO-8713, an EP 3 antagonist, ONO-AE3-240, or an EP 4 antagonist, ONO-AE3-208, at 10 -6 M. On the other hand, lipopolysaccharide (LPS) increased PGE 2 production, but the LPS-induced PGE 2 production was not affected by ONO-8713, PF-04418948, ONO-AE3-240, or ONO-AE3-208. These results indicate that PGE 2 increases COX-2 protein in microglia through the EP 2 receptor supporting the idea that extracellular PGE 2 has a triggering aspect for microglial activation., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Ankylosing spondylitis (AS) is a chronic autoimmune arthritis disease with a genetic background, affecting the skeletal axis, sacroiliac, and peripheral joints. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for AS to alleviate the inflammation and pain. Despite the beneficial effect, their use is accompanied by a wide variety of possible side effects in the gastrointestinal and kidneys. The α-l-guluronic acid (G2013) is a new nonsteroidal anti-inflammatory patented (PCT/EP2017/067920) drug, which has shown its anti-inflammatory properties in the previous investigations. The present study revealed the oral administration effect of G2013 on COX-1 and COX-2 gene expression in AS patients. The blood samples of twelve 18-45 years old patients suffering AS and BASDAI >4, and BASFI >4, before and after 12 weeks of treatment with G2013 and 12 blood samples of healthy volunteers were collected and the effect of G2013 on the gene expression of COX-1 and COX-2 enzymes were assessed by Real-Time PCR. The results indicate that G2013 is able to reduce the gene expression level of COX-1 and COX-2 enzymes in treated AS patients compared to healthy control. Statistically significant differences were not observed between the treatment and the healthy control groups. According to the findings, G2013 might be categorized and introduced as a novel NSAID for the treatment of AS., (© 2020 Wiley Periodicals LLC.)

Aim: Gastrodia elata and Radix aconiti lateralis preparrata are respectively named as Tian-Ma and Fu-Zi (TF) in Chinese. We explored the active components against rheumatoid arthritis (RA) from an extensively used couplet of Chinese herbs, Gastrodia elata and Radix aconiti lateralis preparata (TF) via untargeted metabolomics and network pharmacological approaches., Methods: Water extracts of TF were mixed at ratios 1:1, 3:2 and 2:3 (w/w). Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was then utilized as metabolomics screening. Human Metabolome (http://www.hmdb.ca/) and Lipidmaps (http://www.lipidmaps.org/) databases were used to annotate detected compounds. Further identification of vital genes and important pathways associated with the anti-RA properties of the TF preparations was done via network pharmacology, and verified by real-time quantitative polymerase chain reaction (RT-qPCR)., Results: Four key compounds involved in unsaturated fatty acid biosynthesis and isoflavonoid biosynthesis were identified through metabolomics analyses. Three key components of TF associated with anti-RA activity were linoleic acid, daidzein, and daidzin. Results of RT-qPCR revealed that all 3 tested TF couplets (1:1, 3:2, and 2:3) markedly suppressed the transcription of PTGS2. These results were consistent with our network pharmacological predictions., Conclusions: The anti-RA properties of Tian-Ma and Fu-Zi are associated with the inhibition of arachidonic acid metabolism pathway., (© 2021 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Background: The molecular mechanisms underlying aortic valve calcification are poorly understood. Here, we aimed to identify the master regulators of calcification by comparison of genes in valve interstitial cells (VICs) with calcified and noncalcified aortic valves., Methods: Calcified aortic valves were surgically excised from patients with aortic valve stenosis who required aortic valve replacements. Noncalcified and calcified sections were obtained from aortic valve leaflets. Collagenase-digested tissues were seeded into dishes, and VICs adhering to the dishes were cultured for 3 weeks, followed by comprehensive gene expression analysis. Functional analyses of identified proteins were performed by in vitro calcification assays. Tissue localization was determined by immunohistochemical staining for normal (n = 11) and stenotic valves (n = 30)., Results: We found 87 genes showing greater than a twofold change in calcified tissues. Among these genes, 68 were downregulated and 19 were upregulated. Cyclooxygenase-1 (COX1) messenger RNA and protein levels were upregulated in VICs from calcified tissues. The COX1 messenger RNA and protein levels in VICs were also strongly increased by stimulation with osteoblast differentiation medium. These were VIC-specific phenotypes and were not observed in other cell types. Immunohistochemical staining revealed that COX1-positive VICs were specifically localized in the calcified area of aortic valve tissues., Conclusions: The VIC-specific COX1 overexpression played a crucial role in calcification by promoting osteoblast differentiation in aortic valve tissues., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Aims: We investigated the cardiac effects of ethanol withdrawal and the possible role of AT1 receptors in such response., Methods: Male Wistar rats were treated with increasing doses of ethanol (3 to 9%, vol./vol.) for 21 days. The cardiac effects of ethanol withdrawal were investigated 48 h after abrupt discontinuation of ethanol. Some animals were orally treated with losartan (10 mg/kg/day), a selective AT1 receptor antagonist., Results: Ethanol withdrawal did not affect serum levels of creatine kinase (CK)-MB. Losartan prevented ethanol withdrawal-induced increase in superoxide anion (O2•-) production in the left ventricle (LV). However, ethanol withdrawal did no alter the levels of thiobarbituric acid reactive substances (TBARS) or the expression of Nox1, Nox2 or Nox4 were found in the LV. Ethanol withdrawal reduced the concentration of hydrogen peroxide (H2O2) in the LV and this response was prevented by losartan. Ethanol withdrawal increased catalase activity in the LV and losartan attenuated this response. No changes on superoxide dismutase (SOD) activity or expression were detected in the LV during ethanol withdrawal. The expression of AT1, AT2 or angiotensin converting enzyme (ACE) was not affected by ethanol withdrawal. Similarly, no changes on the expression of ERK1/2, SAPK/JNK, COX-1 or COX-2 were found in the LV during ethanol withdrawal., Conclusions: Ethanol withdrawal altered the cardiac oxidative state through AT1-dependent mechanisms. Our findings showed a role for angiotensin II/AT1 receptors in the initial steps of the cardiac effects induced by ethanol withdrawal., (© The Author(s) 2019. Medical Council on Alcohol and Oxford University Press. All rights reserved.)

Background: The vessel restenosis is related to the inflammatory events in subendothelial space. It is proposed that the inflammatory agents affect the prostaglandin synthesis pathway. In this study, we investigated the COX-1, COX-2, PTGDS and miRNA-520a-5p expression levels and the serum 15-Deoxy-Δ 12,14 -PGJ2 metabolite values in patients with the stenosed and re-stenosed vessels. Furthermore, the associations between genes and miR-520 were evaluated in the monocyte transfection studies., Methods: The subjects (n=60) were included three groups; healthy subjects (control (stenosis < 5%), stent no restenosis (SNR, restenosis < 5%) and in-stent restenosis (ISR, restenosis > 70%)). The miRNA and gene expression levels were measured by RT-qPCR technique. 15-Deoxy-Δ 12,14 -PGJ2 values were measured by the ELISA technique. The miR-520 was transfected into myocytes using PEI polymer., Results: The monocyte COX-1, COX-2 and PTGDS gene expression levels and the serum 15-Deoxy- Δ 12,14 -PGJ2 values increased significantly in the patients. Furthermore, the miR-520 correlated conversely with the COX-1, and PTGDS gene expression levels., Conclusion: The results showed that the PGD2 synthesis pathway is active in the patients and, miR- 520 may be involved in the function of this pathway., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Prostaglandins (PGs) have critical signaling functions in a variety of processes including the establishment and maintenance of pregnancy, and the initiation of labor. Most PGs are non-enzymatically degraded, however, the two PGs most prominently implicated in the termination of pregnancy, including the initiation of labor, prostaglandin E2 (PGE 2 ) and prostaglandin F2α (PGF 2α ), are enzymatically degraded by 15-hydroxyprostaglandin dehydrogenase (15-HPGD). The role of PG metabolism by 15-HPGD in the maintenance of pregnancy remains largely unknown, as direct functional studies are lacking. To test the hypothesis that 15-PGDH-mediated PG metabolism is essential for pregnancy maintenance and normal labor timing, we generated and analyzed pregnancy in 15-HPGD knockout mice (Hpgd -/- ). We report here that pregnancies resulting from matings between 15-HPGD KO mice (Hpgd -/- X Hpgd -/- KO mating) are terminated at mid gestation due to a requirement for embryo derived 15-HPGD. Aside from altered implantation site spacing, pregnancies from KO matings look grossly and histologically normal at days post coitum (dpc) 6.5 and 7.5 of pregnancy. However, virtually all of these pregnancies are resorbed by dpc 8.5. This resorption is preceded by elevation of PGF 2∝ but is not preceded by a decrease in circulating progesterone, suggesting that pregnancy loss is a local inflammatory phenomenon rather than a centrally mediated phenomena. This pregnancy loss can be temporarily deferred by indomethacin treatment, but treated pregnancies are not maintained to term and indomethacin treatment increases maternal mortality. We conclude that PG metabolism to inactive products by embryo derived 15-HPGD is essential for pregnancy maintenance in mice, and may serve a similar function during human pregnancy.

Background: Sixty percent of the mammalian brain is composed of lipids including arachidonic acid (AA). AA released from cell membranes is metabolised in the cyclooxygenase (COX) pathway to prostanoids - biologically active substances involved in the regulation of many processes including inflammation. It has been shown that long-term exposure to fluoride in pre and neonatal period is dangerous because this element is able to penetrate through the placenta and to cross the blood-brain barrier. Exposure to fluoride during the development affects metabolism and physiology of neurons and glia which results in the impairment of cognitive functions but the exact mechanisms of fluoride neurotoxicity are not clearly defined., Objective: The aim of this study was to determine whether exposure to fluoride during the development affects COXes activity and the synthesis of prostanoids., Material and Methods: Pre- and postnatal toxicity model in Wistar rats was used. Experimental animals received 50 mg/L of NaF in drinking water ad libitum, while control animals received tap water. In cerebral cortex, hippocampus, cerebellum and striatum were measured fluoride concentration, COX1 and COX2 genes expression, immunolocalization of the enzymatic proteins and concentration of PGE2 and TXB2., Results: of this study showed statistically significant changes in the concentration of fluoride in brain structures between study group and control animals. Moreover, significant changes in the expression level of COX1 and COX2, and in the concentration of PGE2 and TXB2 were observed., Conclusion: Exposure to fluoride in the prenatal and neonatal period result in the increase in COX2 activity and increase in PGE2 concentration in rats brain, which may lead to disturbances in central nervous system homeostasis.‬‬., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The Moringa plant (Moringa oleifera) is known for its potential medicinal properties and health benefits in addition to its high nutritional value. The current study aimed to investigate the antiulcer effect of moringa leaves and its aqueous extract on pro-inflammatory cytokines and inflammatory mediators in ulcerative rats. Rats were treated with either moringa leaves (10%) or moringa extract (300 mg/kg body weight) for 4 weeks then treated with a single dose of aspirin to induce gastric ulcer. Moringa leaves and its extract markedly reduced ulcer index, gastric volume and total acidity. Both treatments induced a significant increase in gastric mucosal mucin content and plasma NO level associated with significant decrease in plasma TNFα. Moringa leaves and its extract prompted down-regulation of TNFα, TGFβ1 and COX2 genes expression by 2.7, 3.5, and 8.4 fold-change for moringa leaves and 2.7, and 2.3, 4.1 fold-change for moringa extract, respectively. Moringa leaves and extract treatments altered the COX-1 gene expression levels to near normal values. This study confirms the gastro-protective influence of moringa leaves and its extract on aspirin-induced ulcer in rats as manifested by its significant reduction in inflammatory cytokines and normalization of gastric mucosal mucin and NO level. Overall, moringa leaves powder is more efficient as antiulcer agent than moringa extract.

Patients surviving an acute coronary syndrome (ACS) remain at increased risk of ischemic events long term. This paper reviews current evidence and guidelines for oral antiplatelet therapy for secondary prevention following ACS, with respect to decreased risk of ischemic events versus bleeding risk according to individual patient characteristics and risk factors. Specifically, data are reviewed from clinical studies of clopidogrel, prasugrel, ticagrelor and vorapaxar, as well as the results of systematic reviews and meta-analyses looking at the benefits and risks of oral antiplatelet therapy, and the relative merits of shorter versus longer duration of dual antiplatelet therapy, in different patient groups.

This study evaluated whether mRNA expression of major genes regulating formation of prostaglandin (PG)E 2 in the colon and colonic fatty acid concentrations are associated with the reduction in colonic mucosal PGE 2 after dietary supplementation with omega-3 (ω-3) fatty acids. Supplementation with ω-3 fatty acids was done for 12 weeks using personalized dosing that was expected to reduce colonic PGE 2 by 50%. In stepwise linear regression models, the ω-3 fatty acid dose and baseline BMI explained 16.1% of the inter-individual variability in the fold change of colonic PGE 2 post-supplementation. Increases in mRNA gene expression after supplementation were, however, modest and were not associated with changes in PGE 2 . When baseline expression of PTGS1, PTGS2 and HPGD genes was included in the linear regression model containing dose and BMI, only PTGS2, the gene coding for the inducible form cyclooxygenase, was a significant predictor. Higher relative expression of PTGS2 predicted greater decreases in colonic PGE 2 , accounting for an additional 13.6% of the inter-individual variance. In the final step of the regression model, greater decreases in total colonic fatty acid concentrations predicted greater decreases in colonic PGE 2 , contributing to an additional 18.7% of the variance. Overall, baseline BMI, baseline expression of PTGS2 and changes in colonic total fatty acids together accounted for 48% of the inter-individual variability in the change in colonic PGE 2 . This is consistent with biochemical data showing that fatty acids which are not substrates for cyclooxygenases can activate cyclooxygenase-2 allosterically. Further clinical trials are needed to elucidate the factors that regulate the fatty acid milieu of the human colon and how this interacts with key lipid metabolizing enzymes. Given the central role of PGE 2 in colon carcinogenesis, these pathways may also impact on colon cancer prevention by other dietary and pharmacological approaches., (Copyright © 2018. Published by Elsevier Ltd.)

Given the hepatotoxicity and an unfavorable pharmacokinetic profile of zileuton (Zyflo ® ), currently the only approved and clinically used 5-Lipoxygenase (5-LO) inhibitor, the search for potent and safe 5-LO inhibitors is highly demanded. The action of several phenolic acid phenethyl esters as potential 5-Lipoxygenase (5-LO) inhibitors has been investigated. For this purpose, a series of 14 phenethyl esters was synthesized and their impact on 5-LO inhibition was evaluated. The effects of position and number of hydroxyl and methoxy groups on the phenolic acid were investigated. The shortening of the linker between the carbonyl and the catechol moiety as well as the presence of the α,β-unsaturated carbonyl group was also explored. The sinapic acid phenethyl ester (10), which can be named SAPE (10) by analogy to caffeic acid phenethyl ester (CAPE), inhibited 5-LO in a concentration-dependent manner and outperformed both zileuton (1) and CAPE (2). With an IC 50 of 0.3 μm, SAPE (10) was threefold more potent than CAPE (2) and 10-fold more potent than zileuton (1), the only 5-LO inhibitor approved for clinical use. Unlike CAPE (2), SAPE (10) had no effect on 12-lipoxygenase (12-LO) and less effect on cyclooxygenase 1 (COX-1) which makes it a more selective 5-LO inhibitor., (© 2018 John Wiley & Sons A/S.)

Inflammation is an important factor in the development of many diseases of the central nervous system, including Alzheimer's disease and other types of dementia. ‪Given that acetylcholinesterase inhibitors are also currently believed to have anti-inflammatory properties, the purpose of this study was to investigate the effect of acetylcholinesterase inhibitors (rivastigmine, donepezil) on cyclooxygenase activity and expression using the proinflammatory action of fluoride (F - ) on cultured macrophages obtained from THP-1 monocytes. COX-1 and COX-2 activity was determined through measurement of the products of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) in cell culture supernatants. Expression of COX-1 and COX-2 proteins was examined immunocytochemically, and mRNA expression was determined by qRT PCR. ‪‪ Our study confirmed the inhibitory effects of donepezil and rivastigmine on the production of PGE2, TXB2, COX-1 and COX-2 mRNA and protein expression in macrophages. We also demonstrated that the pro-inflammatory effect of fluoride may be reduced by the use of both drugs. The additive effect of these drugs cannot be ruled out, and effects other than those observed in the use of one drug should also be taken into account., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Ameloblastoma is a locally aggressive neoplasm with a poorly understood pathogenesis. Therefore, the aim of this study is to investigate whether COX-2 expression is associated with ameloblastoma microvascular density (MVD) and with tumor aggressiveness. Sixty-three cases of primary ameloblastomas arranged in tissue microarray were submitted to immunohistochemistry against cyclooxigenase-2 (COX-2) and CD34. Clinicopathological parameters regarding sex, age, tumour size, tumour duration, tumour location, treatment, recurrences, radiographic features, vestibular/lingual and basal cortical disruption and follow-up data were obtained from patients' medical records and correlated with the proteins expression. The results on BRAF-V600E expression were obtained from our previous study and correlated with COX-2 and CD34 expressions. Log-rank univariate analysis and multivariate Cox regression model were done to investigate the prognostic potential of the molecular markers. Twenty-eight cases (44.4%) exhibited cytoplasmic positivity for COX-2, predominantly in the columnar peripheral cells, with a mean MVD of 2.2 vessels/mm 2 . COX-2 was significantly associated with recurrences (p < 0.001) and BRAF-V600E expression (p < 0.001), whereas lower MVD was associated with the use of conservative therapy (p = 0.004). Using univariate and multivariate analyses, COX-2 was significantly associated with a lower 5-year disease-free survival (DFS) rate (p < 0.001 and p = 0.012, respectively), but not with a higher MVD (p = 0.68). In conclusion, COX-2 expression in ameloblastomas is not associated with MVD, but it is significantly associated with recurrences and with a lower DFS., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Airway smooth muscle cells (ASMCs) are phenotypically regulated to exist in either a proliferative or a contractile state. However, the influence of other airway structural cell types on ASMC phenotype is largely unknown. Although epithelial cells are known to drive ASM proliferation, their effects on the contractile phenotype are uncertain. In the current study, we tested the hypothesis that epithelial cells reduce the contractile phenotype of ASMCs. To do so, we measured force production by traction microscopy, gene and protein expression, as well as calcium release by Fura-2 ratiometric imaging. ASMCs incubated with epithelial-derived medium produced less force after histamine stimulation. We observed reduced expression of myocardin, α-smooth muscle actin, and calponin within ASMCs after coculture with epithelial cells. Peak calcium release in response to histamine was diminished, and depended on the synthesis of cyclo-oxygenase-1 products by ASM and on prostaglandin E receptors 2 and 4. Together, these in vitro results demonstrate that epithelial cells have the capacity to coordinately reduce ASM contraction by functional antagonism and by reduction of the expression of certain contractile proteins.

The Fas-activated serine/threonine kinase (FASTK) family of proteins has recently emerged as a central regulator of mitochondrial gene expression through the function of an unusual RNA-binding domain named RAP (for RNA-binding domain abundant in Apicomplexans), shared by all six members of the family. Here we describe the role of one of the less characterized members, FASTKD3, in mitochondrial RNA metabolism. First, we show that, in contrast to FASTK, FASTKD2, and FASTKD5, FASTKD3 does not localize in mitochondrial RNA granules, which are sites of processing and maturation of mtRNAs and ribosome biogenesis. Second, we generated FASTKD3 homozygous knock-out cell lines by homologous recombination and observed that the absence of FASTKD3 resulted in increased steady-state levels and half-lives of a subset of mature mitochondrial mRNAs: ND2, ND3, CYTB, COX2, and ATP8/6. No aberrant processing of RNA precursors was observed. Rescue experiments demonstrated that RAP domain is required for FASTKD3 function in mRNA stability. Besides, we describe that FASTKD3 is required for efficient COX1 mRNA translation without altering mRNA levels, which results in a decrease in the steady-state levels of COX1 protein. This finding is associated with reduced mitochondrial complex IV assembly and activity. Our observations suggest that the function of this family of proteins goes beyond RNA processing and ribosome assembly and includes RNA stability and translation regulation within mitochondria., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

Mitochondrial ribosomes translate membrane integral core subunits of the oxidative phosphorylation system encoded by mtDNA. These translation products associate with nuclear-encoded, imported proteins to form enzyme complexes that produce ATP. Here, we show that human mitochondrial ribosomes display translational plasticity to cope with the supply of imported nuclear-encoded subunits. Ribosomes expressing mitochondrial-encoded COX1 mRNA selectively engage with cytochrome c oxidase assembly factors in the inner membrane. Assembly defects of the cytochrome c oxidase arrest mitochondrial translation in a ribosome nascent chain complex with a partially membrane-inserted COX1 translation product. This complex represents a primed state of the translation product that can be retrieved for assembly. These findings establish a mammalian translational plasticity pathway in mitochondria that enables adaptation of mitochondrial protein synthesis to the influx of nuclear-encoded subunits., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)

Previous studies suggest that cyclooxygenase-2 (COX-2) might influence megakaryocyte (MK) maturation and platelet production in vitro. Using a gene deletion model, we analysed the effect of COX-2 deficiency on megakaryopoiesis and platelet function. COX-2-/- mice (10-12 weeks old) have hyper-responsive platelets as suggested by their enhanced aggregation, TXA2 biosynthesis, CD62P and CD41/CD61 expression, platelet-fibrinogen binding, and increased thromboembolic death after collagen/epinephrine injection compared to wild-type (WT). Moreover, increased platelet COX-1 expression and reticulated platelet fraction were observed in COX-2-/- mice while platelet count was similar to WT. MKs were significantly reduced in COX-2-/- bone marrows (BMs), with high nuclear/cytoplasmic ratios, low ploidy and poor expression of lineage markers of maturation (CD42d, CD49b). However, MKs were significantly increased in COX-2-/- spleens, with features of MK maturation markers which were not observed in MKs of WT spleens. Interestingly, the expression of COX-1, prostacyclin and PGE2 synthases and prostanoid pattern were modified in BMs and spleens of COX-2-/- mice. Moreover, COX-2 ablation reduced the percentage of CD49b+ cells, the platelet formation and the haematopoietic stem cells in bone marrow and increased their accumulation in the spleen. Splenectomy decreased peripheral platelet number, reverted their hyper-responsive phenotype and protected COX-2-/- mice from thromboembolism. Interestingly, fibrosis was observed in spleens of old COX-2-/- mice (28 weeks old). In conclusion, COX-2 deletion delays BM megakaryopoiesis promoting a compensatory splenic MK hyperplasia, with a release of hyper-responsive platelets and increased thrombogenicity in vivo. COX-2 seems to contribute to physiological MK maturation and pro-platelet formation.

Aims: Investigate the effects of chronic ethanol consumption on erectile function and on the corpus cavernosum (CC) reactivity to endothelin-1 (ET-1)., Main Methods: Male Wistar rats were treated with ethanol (20% v/v) for six weeks., Key Findings: Ethanol-treated rats showed impaired erectile function represented by decreased intracavernosal pressure/mean arterial pressure (ICP/MAP) responses. Ethanol consumption increased the contractile response induced by ET-1 in the isolated CC. Tiron increased ET-1-induced contraction in CC from control and ethanol-treated rats. No differences in the maximal contraction to ET-1 were observed after incubation of CC with PEG-catalase. SC560 and SC236 increased ET-1-induced contraction in CC from ethanol-treated rats. Y27632 reduced the contraction induced by ET-1 in CC from control and ethanol-treated rats. Ethanol increased plasma TBARS, superoxide anion (O2(-)) levels and intracellular reactive oxygen species (ROS) generation in the rat CC. Reduced hydrogen peroxide (H2O2) levels in CC and increased catalase (CAT) activity in plasma and CC were detected after treatment with ethanol. Ethanol decreased superoxide dismutase (SOD) activity in the rat CC. Increased expression of COX-1 was observed in CC from ethanol-treated rats. Treatment with ethanol decreased COX-2 expression but did not alter the expression of Nox1, RhoA and p-RhoA (ser(188)) in the rat CC., Significance: The major new findings of our study are that ethanol consumption induces erectile dysfunction (ED) and increases the contraction induced by ET-1 in the rat CC by a mechanism that involves decreased generation of H2O2 and vasodilator prostanoids as well as increased activation of the RhoA/Rho-kinase pathway., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: NOSH-aspirin, a novel hybrid that releases nitric oxide (NO) and hydrogen sulfide (H 2 S) was designed to overcome the potential side effects of aspirin., Aim: We compared the cell growth inhibitory properties of ortho-, meta-, and para-NOSH-aspirins. Effects of electron donating/withdrawing groups on the stability and biological activity of these novel compounds were also evaluated., Methods: Cell line: HT-29 (Cyclooxygenase, COX-1 & -2 expressing) and HCT 15 (COX null) human colon adenocarcimoa; Cell growth: MTT; Cell cycle phase distribution: Flow cytometry; Apoptosis: subdiploid (sub-G 0 /G 1 ) peak in DNA content histograms; Proliferation: PCNA; ROS: measured hydrogen peroxide and super oxide by flow cytometry using DCFDA and DHE dyes., Results: The IC 50 s for growth inhibition in µM at 24h were, HT-29: ortho-NOSH-ASA (0.04±0.011), meta-NOSH-ASA (0.24±0.11), para-NOSH-ASA (0.46±0.17); significance between the groups were: o vs m P>0.05, o vs p P<0.05, m vs p P>0.05; HCT 15: ortho-NOSH-ASA (0.062±0.006), meta-NOSH-ASA (0.092±0.004), para-NOSH-ASA (0.37±0.04); significance between the groups were: o vs m P<0.01, o vs p P<0.001, m vs p P<0.001. Electron donating/withdrawing groups significantly affected these IC 50 s. All positional isomers qualitatively had similar effects on proliferation, apoptosis, and caused G 0 /G 1 cell cycle arrest in both colon cancer cell lines. The underlying mechanism for these observations appeared to be mediated through ROS, as pretreatment of the cells with N-acetylcysteine, partially blocked these effects., Conclusions: Positional isomerism affects the potency of NOSH-aspirin. The effects appear to be COX independent., (Copyright © 2015. Published by Elsevier B.V.)

This study aimed to investigate the modulation of nitric oxide/reactive oxygen species in sodium nitroprusside relaxation in mice aorta. Sodium nitroprusside induced relaxation in endothelium-intact (e+) and endothelium-denuded (e-) aortas with greater potency in e+ than in e-. The nitric oxide synthase inhibitor did not alter the sodium nitroprusside relaxation in both e+ and e- aortas. However, the superoxide anion scavenger abolished the difference in sodium nitroprusside potency between e+ and e-. Sodium nitroprusside reduced dihydroethidium-derived fluorescent products in both groups; however, the difference between intact and denuded mice aorta remains. The glutathione levels and basal antioxidant activity of superoxide dismutase were reduced in e- aorta when compared with e+, and these values were not altered by sodium nitroprusside. Confirming these results, the levels of lipid peroxidation in e+ were significantly lower when compared to e-, and these values were not altered by sodium nitroprusside. The sodium nitroprusside potency in the presence of a nonselective COX inhibitor or the EP/DP prostaglandin receptor antagonist in endothelium denuded was similar to that in intact mice aorta. Based on these results, we performed the COX-1 and COX-2 mRNA level studies, and in denuded mice aorta, there was an upregulation in COX-1 mRNA levels. Taken together, our findings show that in the absence of endothelium, there is an enhancement of superoxide levels, leading to GSH consumption and higher levels of lipid peroxidation, showing an intense redox status. Furthermore, in denuded mice aorta, there was an upregulation of COX-1 mRNA expression, leading to vasoconstrictor prostanoids synthesis. The interaction of vasoconstrictor prostanoids with its receptors EP/DP negatively modulates the vascular relaxation induced by SNP in denuded mice aorta., (© 2015 Société Française de Pharmacologie et de Thérapeutique.)

Experimental, epidemiological, and clinical data from the last two decades have each supported the hypothesis that aspirin possesses anticancer properties, and that its use may also reduce the lifetime probability of developing or dying from a number of cancers. Aspirin's ability to act on multiple key metabolic and signaling pathways via inhibition of the cyclooxygenase (COX) enzyme, as well as through COX-independent mechanisms, makes it particularly relevant in the fight against cancer. A growing body of evidence indicates that aspirin may not only reduce cancer risk, but also prevent metastasis and angiogenesis while slowing the rate of mutation-inducing DNA damage. These emerging benefits of aspirin are offset to some extent by the known risks of treatment, such as cardiovascular events and gastrointestinal bleeding. However, it has been shown that pre-treatment risk assessment of individual patients and the use of proton pump inhibitors or Helicobacter pylori eradication therapy concomitantly with aspirin treatment can reduce these potential risks. Thus, the significant benefits of aspirin treatment, coupled with recent data concerning its risks, may prove to tip the balance in favor of aspirin use in cancer prevention., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: We investigated a subject with an isolated cytochrome c oxidase (COX) deficiency presenting with an unusual phenotype characterised by neuropathy, exercise intolerance, obesity, and short stature., Methods and Results: Blue-native polyacrylamide gel electrophoresis (BN-PAGE) analysis showed an almost complete lack of COX assembly in subject fibroblasts, consistent with the very low enzymatic activity, and pulse-labelling mitochondrial translation experiments showed a specific decrease in synthesis of the COX1 subunit, the core catalytic subunit that nucleates assembly of the holoenzyme. Whole exome sequencing identified compound heterozygous mutations (c.199dupC, c.215A>G) in COA3, a small inner membrane COX assembly factor, resulting in a pronounced decrease in the steady-state levels of COA3 protein. Retroviral expression of a wild-type COA3 cDNA completely rescued the COX assembly and mitochondrial translation defects, confirming the pathogenicity of the mutations, and resulted in increased steady-state levels of COX1 in control cells, demonstrating a role for COA3 in the stabilisation of this subunit. COA3 exists in an early COX assembly complex that contains COX1 and other COX assembly factors including COX14 (C12orf62), another single pass transmembrane protein that also plays a role in coupling COX1 synthesis with holoenzyme assembly. Immunoblot analysis showed that COX14 was undetectable in COA3 subject fibroblasts, and that COA3 was undetectable in fibroblasts from a COX14 subject, demonstrating the interdependence of these two COX assembly factors., Conclusions: The mild clinical course in this patient contrasts with nearly all other cases of severe COX assembly defects that are usually fatal early in life, and underscores the marked tissue-specific involvement in mitochondrial diseases., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Intramural ganglia are present in the bladder wall of several species including human, pig, and guinea-pig. It has been suggested that there is a network of intramural ganglia in the bladder of these species that may be part of a motor-sensory system and receive afferent input. Prostaglandins (PG) have been suggested to play a role in this afferent signalling mechanism. To investigate the distribution of the prostaglandin E2 receptors EP1 and EP2 in and around intramural ganglia of the guinea pig, bladders of 6 guinea pigs were dissected, and processed for immunohistochemistry. Sections were examined for prostaglandin E2 receptor EP1- and EP2-immuno-reactivity and co-stained for vimentin, a marker for interstitial cells (IC) and cyclo-oxygenase 1 (COX I), the enzyme responsible for PG synthesis. Immunoreactivities for EP1 and EP2 were found in intramural ganglion cells. These cells were observed in between muscle bundles and on, or close to the serosal surface of the bladder. Furthermore, COX I was present in interstitial cells close to ganglion cells, indicating the possibility of a local synthesis of prostaglandins near the ganglia. The co-staining of EP1 or EP2 with vimentin showed that processes of interstitial cells run through the ganglia, often encircling or ensheathing cells. Therefore, it can be concluded that there is a close relationship between the intramural ganglia and the network of interstitial cells in the muscular layers of the bladder. EP1 and EP2 receptors are expressed on the ganglia and this arrangement suggests that intramural ganglia are involved in (pre)processing afferent information., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Vanadium is a metal present in air pollution. Its compounds may have both anticancer and carcinogenic properties. Vanadium compounds are tested in treatment of diabetes and cancer. An important research direction aimed at better understanding of the mechanisms of action of the vanadium compounds is a more detailed insight into their impact on inflammatory reactions. The aim of this study was to examine the effect of micromolar concentrations of sodium orthovanadate, Na3VO4, on the activity and expression of cyclooxygenases: COX-1 and COX-2. PMA-activated THP-1 macrophages were incubated in vitro for 48 h with micromolar concentrations of sodium orthovanadate. As shown by an ELISA assay, sodium orthovanadate increases the quantity of prostaglandin E2 being released into the medium in a dose-dependent manner as well as impacts the quantity of the stable metabolite of thromboxane A2: thromboxane B2. The use of a COX-2 inhibitor, NS-398, revealed that this effect was independent of changes in the activity of COX-2. Western blotting analysis showed that sodium orthovanadate increased the expression of COX-2 when used with NS-398. Quantitative real-time PCR measurements of mRNA levels of genes PTGS1 and PTGS2 revealed no effect of the tested vanadium compound on the levels of analyzed transcripts.

Cyclooxygenase is the rate limiting enzyme in the production of prostaglandins. In birds two isoforms are present: cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). Despite evidence implicating that cyclooxygenases and PGs are critical factors in female reproduction in birds, little is known about COX expression in the avian ovary. In birds, cyclooxygenases have been studied in very few species only. In this study we report on the expression of COX-1 and COX-2 in the ovary of the ostrich (Struthio camelus) using immunohistochemistry and non-radioactive in situ hybridization techniques. Our results demonstrate that COX-1 is strongly expressed in the cytoplasm of oocytes of previtellogenic follicles, whereas COX-2 shows the strongest immunostaining in the granulosa cells of previtellogenic follicles. The signals of both isoenzymes fade significantly with increasing diameter and finally nearly vanish in the vitellogenic follicles with a size >1.8 cm. This expression pattern in the ostrich (S. camelus) is, therefore, completely different from the localization of COX-1 and COX-2 in the hen (Gallus gallus), a finding which also suggests different functions of the cyclooxygenases in the ostrich species. Non-radioactive in situ hybridization confirmed that COX-1 is synthesized in the ooplasm and COX-2 in the granulosa layers of early previtellogenic follicles. According to the results of this study it appears unlikely that COX-1 or COX-2 play a major role in ovulation and oviposition in the ostrich., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

Objective: Platelet activation plays a pivotal role in the pathogenesis of thrombosis, which can lead to fatal diseases such as myocardial or cerebral infarction, and atherosclerosis. The present study focused on investigating the effect of CAPE-NO2 against collagen-induced platelet aggregation., Methods: Caffeic acid phenethyl ester (CAPE) is an active component in propolis. CAPE-NO2 is a nitro derivative of CAPE. Its effects on rat platelet aggregation induced by collagen were tested in vitro and the potential mechanisms underlying the activities were investigated., Results: CAPE-NO2 significantly inhibited collagen-induced platelet aggregation in a concentration-dependent manner. It also reduced TXB2 formation and COX-1 activity in collagen-activated platelets. Moreover, CAPE-NO2 caused an increase in NO production and cGMP levels and attenuated 5-HT release in the collagen-activated platelets., Conclusion: These findings suggest that the inhibitory mechanism of CAPE-NO2 on collagen-induced platelet aggregation might be associated with the down-regulation of TXB2, COX-1 and 5-HT and the elevation of NO and cGMP production. These indicators are closely related to platelet function. So CAPE-NO2 may be a promising candidate for the extension of the current spectrum of antiplatelet drugs.

In this study, we determined if vitamin D could inhibit oxidative stress-induced thromboxane production by placental trophoblasts. Trophoblast isolated from normal placentas were stimulated with CoCl2, a hypoxic mimicking agent, with or without pretreatment of 1,25(OH)2D3. Soluble phospholipase-A2, metabolites of thromboxane-A2 and prostacyclin, and 8-isoprostane were measured. Expression of cyclooxygenase-1 (COX-1), COX-2, and heme oxygenase-1 (HO-1) were determined. We found that pretreatment of trophoblasts with 1,25(OH)2D3 significantly reduced 8-isoprostane and the ratio of thromboxane-A2 to prostacyclin production, and blocked COX-2 expression induced by CoCl2. These results provide evidence of the beneficial effects of vitamin D on placental trophoblasts., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Brain death is linked to a systemic inflammatory response that includes prostaglandins and cytokines among its mediators. The levels of cyclooxygenase-1 and cyclooxygenase-2 (COX-1 and COX-2) affect graft survival, but it remains unknown whether these enzymes are modified during brain death. The aims of this study were to investigate the organ expression of COX and to analyse the cytokine response in the plasma, cerebrospinal fluid (CSF), and organs in a porcine model of intracerebral haemorrhage and brain death., Methods: Twenty pigs were randomly assigned to either a brain death group or a control group. Brain death was induced by an intracerebral injection of blood, and the animals were observed over the next 8 h. Tissue samples were tested for COX-1, COX-2 messenger RNA (mRNA) expression (heart, lung, and kidney), haeme oxygenase-1 (HO-1) (kidney), interleukin-1β (IL-1β), IL-6, IL-8, IL-10, and tumour necrosis factor-α. These cytokines were also measured at eight time points in the plasma and CSF., Results: At the organ level, the levels of COX-1 and COX-2 mRNA expression were increased only in the renal medulla (P = 0.03 and P = 0.02, respectively). The cytokine levels in the tissue, plasma, and CSF revealed no differences between the groups. HO-1 expression decreased (P = 0.0088)., Conclusion: Brain death increases the expression of COX-1 and COX-2 mRNA in the renal medulla. The release of cytokines into the plasma and CSF did not vary between the groups., (© 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Introduction: The pharmacological target of aspirin is the inhibition of cyclooxygenase-1 (COX1) and thromboxane-A2 (TX) synthesis. Very few data are available on TX assessment in patients with stroke. We studied platelet TX synthesis, COX1-independent platelet reactivity, the influence of platelet-erythrocyte interactions and the potential association between platelet responses and the severity of stroke, evaluated with a clinical score (NIHSS)., Material and Methods: We examined 157 aspirin-treated patients with acute stroke or TIA, 128 aspirin-free and 15 aspirin-treated healthy subjects (HS). Collagen-induced TX, platelet recruitment in whole blood and platelets ± erythrocytes (haematocrit 40%) were assessed in patients on daily-aspirin within three days from onset. Arachidonic-acid-, ADP-, thrombin-receptor activating peptide TRAP-, and collagen-induced aggregation were also evaluated., Results: Partial TX inhibition (<95% inhibition vs aspirin-free controls) was observed in 13% of patients. This was associated with marked increases in COX1-dependent responses (arachidonic-acid- and collagen-induced aggregation and platelet recruitment; P<0.0001) but not with differences in ADP- or TRAP-induced aggregation. Partial TX inhibition was independently associated with severe stroke (NIHSS ≥ 12) at both admission (P<0.05) and discharge (P<0.05). Among patients with fully blocked TX, those with elevated COX1-independent platelet reactivity (mean+2SD of aspirin-treated HS) were most likely to suffer severe stroke (P<0.05). Platelet-erythrocyte interactions enhanced platelet reactivity in these patients by COX1-dependent and -independent mechanisms (P<0.0001)., Conclusions: TX inhibition by aspirin varied across patients. Partial TX inhibition and COX1-independent platelet hyperfunction were associated with more-severe stroke., (Copyright © 2013. Published by Elsevier Ltd.)

Damaging of peripheral nerves may result in chronic neuropathic pain for which the likelihood is increased in the elderly. We assessed in mice if age-dependent alterations of endocannabinoids contributed to the heightened vulnerability to neuropathic pain at old age. We assessed nociception, endocannabinoids and the therapeutic efficacy of R-flurbiprofen in young and aged mice in the spared nerve injury model of neuropathic pain. R-flurbiprofen was used because it is able to reduce neuropathic pain in young mice in part by increasing anandamide. Aged mice developed stronger nociceptive hypersensitivity after sciatic nerve injury than young mice. This was associated with low anandamide levels in the dorsal root ganglia, spinal cord, thalamus and cortex, which further decreased after nerve injury. In aged mice, R-flurbiprofen had only weak antinociceptive efficacy and it failed to restore normal anandamide levels after nerve injury. In terms of the mechanisms, we found that fatty acid amide hydrolase (FAAH) which degrades anandamide, was upregulated after nerve injury at both ages, so that this upregulation likely did not account for the age-dependent differences. However, enzymes contributing to oxidative metabolism of anandamide, namely cyclooxygenase-1 and Cyp2D6, were increased in the brain of aged mice, possibly enhancing the oxidative breakdown of anandamide. This may overwhelm the capacity of R-flurbiprofen to restore anandamide homeostasis and may contribute to the heightened risk for neuropathic pain at old age., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Frozen shoulder is a debilitating condition characterized by gradual loss of glenohumeral motion with chronic inflammation and capsular fibrosis. Yet its pathogenesis remains largely unknown. We hypothesized that the subacromial bursa may be responsible for the pathogenesis of frozen shoulder by producing inflammatory cytokines., Materials and Methods: We obtained joint capsules and subacromial bursae from 14 patients with idiopathic frozen shoulder and from 7 control subjects to determine the expression levels of interleukin (IL) 1α, IL-1β, IL-6, tumor necrosis factor α (TNF-α), cyclooxygenase (COX) 1, and COX-2 by real-time reverse transcriptase-polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay., Results: IL-1α, IL-1β, TNF-α, COX-1, and COX-2 were expressed at significantly high levels in the joint capsules of the frozen shoulder group compared with those of the control group. Intriguingly, IL-1α, TNF-α, and COX-2 were also expressed at significantly high levels in the subacromial bursae of the frozen shoulder group compared with those of the control group. Immunohistochemical analysis showed increased expression of COX-2 in both the joint capsules and subacromial bursae of the frozen shoulder group., Conclusions: These findings imply that elevated levels of inflammatory cytokines in the subacromial bursa may be associated with the pathogenesis of inflammation evolving into fibrosis., (Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

It is well-established that prostaglandins (PGs) affect tumorigenesis, and evidence indicates that PGs also are important for the reduced food intake and body weight loss, the anorexia-cachexia syndrome, in malignant cancer. However, the identity of the PGs and the PG producing cyclooxygenase (COX) species responsible for cancer anorexia-cachexia is unknown. Here, we addressed this issue by transplanting mice with a tumor that elicits anorexia. Meal pattern analysis revealed that the anorexia in the tumor-bearing mice was due to decreased meal frequency. Treatment with a non-selective COX inhibitor attenuated the anorexia, and also tumor growth. When given at manifest anorexia, non-selective COX-inhibitors restored appetite and prevented body weight loss without affecting tumor size. Despite COX-2 induction in the cerebral blood vessels of tumor-bearing mice, a selective COX-2 inhibitor had no effect on the anorexia, whereas selective COX-1 inhibition delayed its onset. Tumor growth was associated with robust increase of PGE(2) levels in plasma - a response blocked both by non-selective COX-inhibition and by selective COX-1 inhibition, but not by COX-2 inhibition. However, there was no increase in PGE(2)-levels in the cerebrospinal fluid. Neutralization of plasma PGE(2) with specific antibodies did not ameliorate the anorexia, and genetic deletion of microsomal PGE synthase-1 (mPGES-1) affected neither anorexia nor tumor growth. Furthermore, tumor-bearing mice lacking EP(4) receptors selectively in the nervous system developed anorexia. These observations suggest that COX-enzymes, most likely COX-1, are involved in cancer-elicited anorexia and weight loss, but that these phenomena occur independently of host mPGES-1, PGE(2) and neuronal EP(4) signaling., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: For decades, there have been many ongoing attempts to use prostaglandin I(2) (PGI(2)) to treat heart diseases, such as pulmonary arterial hypertension. However, the short half life of PGI(2) has limited the therapeutic impact potential., Methods: Here, we have engineered a novel adipose tissue-derived cell that constantly produces PGI(2,) through transfecting of an engineered cDNA of a hybrid enzyme (human COX-1-10-aa-PGIS) which has superior triple catalytic functions in directly converting arachidonic acid into PGI(2)., Results: The gene-transfected cells were further converted into a stable cell line, in which cells constantly express the hybrid enzyme and are capable of producing large-amounts of PGI(2). In a comparison between un-transfected- and gene-transfected cells, it was determined that the majority of the endogenous AA metabolism shifted from that of unwanted PGE(2) (in un-transfected cells) to that of the preferred PGI(2) (in gene-transfected cells) with a PGI(2)/PGE(2) ratio change from 0.03 to 25. The PGI(2)-producing cell line not only exhibited an approximate 50-fold increase in PGI(2) biosynthesis, but also demonstrated superior anti-platelet aggregation in vitro, and increased reperfusion in the mouse ischemic hindlimb model in vivo., Conclusions: The cells, which have an ability to increase the biosynthesis of the vascular protector, PGI(2), while reducing that of the vascular inflammatory mediator, PGE(2), provide a dual effect on vascular protection, which is not available through any existing drug treatments. Thus, the current finding has potential to be an experimental intervention for PGI(2)-deficient heart diseases, such as pulmonary arterial hypertension., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The time-course for aging-associated effects on vascular reactivity to U46619, a stable analogue of thromboxane A(2) (TXA(2)), was studied in aorta from female senescence-accelerated mice-prone (SAMP8), a murine model of accelerated senescence. SAMP8 and senescence-accelerated mice-resistant (SAMR1) were divided into three groups: 3-, 6- and 10-month-old. Contractile curves to U46619 (10(-9) to 10(-6) M) were performed in aortic rings in the absence or in the presence of nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 10(-4) M) and/or cyclooxygenase (COX) inhibitor indomethacin (10(-5) M). Protein and gene expression for COX-1 and COX-2 were determined by immunofluorescence and real-time PCR, respectively. Maximal contraction to U46619 was markedly higher in SAMP8 at all ages. In SAMR1, increases were seen at 10 months, while SAMP8 displays augmented contraction at 6 months, which was further increased at 10 months. L-NAME enhanced U46619 contractions in both 6-month-old groups, although the increase was higher on vessels from SAMR1 at this age. Indomethacin equally increased U46619 contractions in both 3-month-old groups, suggesting the production of vasodilator prostaglandin in young animals. In contrast, at 6 and 10 months indomethacin decreased U46619 contractions in both groups, indicating an aging-associated swap to a release of contractile prostanoids in aorta. In conclusion, aging enhances contractile responses to TXA(2) in aorta from female mice by a mechanism involving a decrease of NO production and increased action of contractile prostanoids. This process occurs earlier in SAMP8 mice, establishing these mice as good model to study cardiovascular aging in a convenient and standard time-course.

Here we have characterized perthamide C, a cyclopeptide from a Solomon Lithistid sponge Theonella swinhoei, which displays an anti-inflammatory/immunomodulatory activity. The study has been performed using the carragenan-induced mouse paw edema that displays an early (0-6 h) and a late phase (24-96 h). Perthamide C significantly inhibits neutrophils infiltration in tissue both in the early and late phases. This effect was coupled to a reduced expression of the endothelial nitric oxide synthase (eNOS) in the early phase while cyclooxygenase-1 and 2 (COX-1, COX-2), and inducible NOS (iNOS) expression were unaffected. In the late phase perthamide C reduced expression of both NOS isoforms without affecting COXs expression. This peculiar selectivity toward the two enzymes deputed to produce NO lead us to investigate on a possible action of perthamide C on lymphocytes infiltration and activation. We found that perthamide C inhibited the proliferation of peripheral lymphocytes, and that this effect was secondary to its metabolic activation in vivo. Indeed, in vitro perthamide C did not inhibit proliferation as opposite to its metabolite perthamide H. In conclusion, perthamide C selectively interferes with NO generation triggered by either eNOS or iNOS without affecting either COX-1 or COX-2. This in turn leads to modulation of the inflammatory response through a reduction of vascular permeability, neutrophil infiltration as well as lymphocyte proliferation.

Chronic inflammation has been linked to cancer. Prostaglandin E₂ (PGE₂) is the most pro-inflammatory lipid and one of the downstream products of 2 isoforms of cyclooxygenase (COX) enzymes: COX-1 and COX-2. Ovarian cancer is the most lethal gynecological malignancy and mainly occurs in older women. The factors that contribute to the correlation of age and ovarian cancer are unknown. The purpose of this study was to examine the expression of COX enzymes and PGE₂ levels in ovaries and correlate them to ovarian cancer and aging. White Leghorn hens aged 1, 1.5, 2, 2.5, 3 and 3.5 years were used. The incidence of ovarian cancer was determined by gross pathology and histology. COX-1 and COX-2 protein and mRNA expression and PGE₂ concentrations in ovaries were measured using Western blot, quantitative real-time PCR and ELISA, respectively. Our results indicated an increase in ovarian cancer incidence and expression of both COX enzymes in ovaries of older hens. In correlation with ovarian cancer incidence and COX enzymes expression, PGE₂ concentrations were elevated with age. Ovaries with tumor had elevated COX-1 expression and PGE₂ concentration compared to normal ovaries. Our findings suggest that the up-regulation of COX enzymes with age is the main contributing factor in the age associated increase in PGE₂. Furthermore, elevated PGE₂ in ovaries of hens concomitant with age suggests its important role in early stages of ovarian carcinogenesis. These finding may provide the basis for clinical trials utilizing COX specific inhibitors or dietary intervention targeting prostaglandin biosynthesis for the prevention and treatment of ovarian cancer., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Calcium-independent phospholipase A(2) group VIA (iPLA(2)β) releases docosahexaenoic acid (DHA) from phospholipids in vitro. Mutations in the iPLA(2)β gene, PLA2G6, are associated with dystonia-parkinsonism and infantile neuroaxonal dystrophy. To understand the role of iPLA(2)β in brain, we applied our in vivo kinetic method using radiolabeled DHA in 4 to 5-month-old wild type (iPLA(2)β(+/+)) and knockout (iPLA(2)β(-/-)) mice, and measured brain DHA kinetics, lipid concentrations, and expression of PLA(2), cyclooxygenase (COX), and lipoxygenase (LOX) enzymes. Compared to iPLA(2)β(+/+) mice, iPLA(2)β(-/-) mice showed decreased rates of incorporation of unesterified DHA from plasma into brain phospholipids, reduced concentrations of several fatty acids (including DHA) esterified in ethanolamine- and serine-glycerophospholipids, and increased lysophospholipid fatty acid concentrations. DHA turnover in brain phospholipids did not differ between genotypes. In iPLA(2)β(-/-) mice, brain levels of iPLA(2)β mRNA, protein, and activity were decreased, as was the iPLA(2)γ (Group VIB PLA(2)) mRNA level, while levels of secretory sPLA(2)-V mRNA, protein, and activity and cytosolic cPLA(2)-IVA mRNA were increased. Levels of COX-1 protein were decreased in brain, while COX-2 protein and mRNA were increased. Levels of 5-, 12-, and 15-LOX proteins did not differ significantly between genotypes. Thus, a genetic iPLA(2)β deficiency in mice is associated with reduced DHA metabolism, profound changes in lipid-metabolizing enzyme expression (demonstrating lack of redundancy) and of phospholipid fatty acid content of brain (particularly of DHA), which may be relevant to neurologic abnormalities in humans with PLA2G6 mutations., (Published by Elsevier B.V.)

Substantial evidence supports important independent roles for lymphangiogenic growth factor signaling and prostaglandins in the metastatic spread of cancer. The significance of the lymphangiogenic growth factors, vascular endothelial growth factor (VEGF)-C and VEGF-D, is well established in animal models of metastasis, and a strong correlation exits between an increase in expression of VEGF-C and VEGF-D, and metastatic spread in various solid human cancers. Similarly, key enzymes that control the production of prostaglandins, cyclooxygenases (COX-1 and COX-2, prototypic targets of Non-steroidal anti-inflammatory drugs (NSAIDs)), are frequently over-expressed or de-regulated in the progression of cancer. Recent data have suggested an intersection of lymphangiogenic growth factor signaling and the prostaglandin pathways in the control of metastatic spread via the lymphatic vasculature. Furthermore, this correlates with current clinical data showing that some NSAIDs enhance the survival of cancer patients through reducing metastasis. Here, we discuss the potential biochemical and cellular basis for such anti-cancer effects of NSAIDs through the prostaglandin and VEGF signaling pathways.

Cyclo-oxygenase (COX) enzymes are responsible for the formation from arachidonic acid of prostaglandins, among other metabolites. Prior studies have suggested that inhibition of the COX pathway attenuates the responses of sympathetic nerve activity and blood pressure during static muscle contraction. Static muscle contraction activates the exercise pressor reflex, which in turn increases sympathetic nerve activity and blood pressure. Also, COX products contribute to exaggeration of the exercise pressor reflex in heart failure (HF). This dysfunction of the exercise pressor reflex has previously been shown to be mediated primarily by muscle mechanoreflex overactivity. It is well known that COX-1 and COX-2 are two isoforms of the enzyme that lead to formation of these important biological mediators involved in the muscle reflex. Thus, in the present study, we determined whether the COX-1 and/or COX-2 pathway contribute(s) to the augmented mechanoreflex activity in HF. First, Western blot analysis was employed to examine protein expression of COX-1 and COX-2 in skeletal muscle tissue of control rats and rats with HF induced by myocardial infarction. Our data show that there is no significant difference in COX-1 expression in both experimental groups. However, COX-2 displays significant overexpression in rats with HF compared with control rats (optical density 1.06 ± 0.05 in control and 1.6 ± 0.05 in HF, P < 0.05 versus control). Second, the mechanoreflex was evoked by passive tendon stretch, and the reflex sympathetic and pressor responses to muscle stretch were examined after COX-1 and COX-2 inhibitors (FR-122047 and SC-236) were individually injected into the arterial blood supply of the hindlimb muscles. The results demonstrate that the stretch-evoked reflex responses in rats with HF were significantly attenuated by administration of SC-236, but not by FR-122047, i.e. renal sympathetic nerve activity and mean arterial pressure responses evoked by 0.5 kg of muscle tension were 52.3 ± 8.9% and 19 ± 1.4 mmHg, respectively, in control conditions and 26.4 ± 5.6% and 5.7 ± 1.6 mmHg (P < 0.05 versus control group) after 0.25 mg kg(-1) of SC-236. Muscle stretch-evoked renal sympathetic nerve activity and mean arterial pressure responses were 51.8 ± 8.2% and 18.7 ± 1.2 mmHg, respectively, in control conditions and 48.3 ± 5.3% and 17.5 ± 1.9 mmHg (P > 0.05 versus control group) after 1.0 mg kg(-1) of FR-122047. Accordingly, the results obtained from this study support our hypothesis that heightened COX-2 expression within the hindlimb muscles contributes to the exaggerated muscle mechanoreflex in congestive HF.

Recombinant human cyclooxygenase 1 (COX-1) was expressed from stably-transfected Drosophila melanogaster S2 (S2) cells. DMSO improved the expression of recombinant COX-1 by 180 %. DMSO increased the expression of nitric oxide synthase (NOS) at both the RNA and protein levels; NOS expression was closely correlated with the synthesis of recombinant COX-1 mRNA in stably-transfected S2 cells. DMSO also induced the gene encoding Kr-h1 which binds to the CACCC element of the metallothionein promoter to enhance the expression of recombinant COX-1. Therefore, DMSO improves the expression of recombinant COX-1 via NOS and/or the transcription factor Kr-h1.

Introduction: We have shown that diesel exhaust (DE) inhalation caused progression of atherosclerosis; however, the mechanisms are not fully understood. We hypothesize that exposure to DE upregulates cyclooxygenase (COX) expression and activity, which could play a role in DE-induced atherosclerosis., Methods: ApoE knockout mice (30-week old) fed with regular chow were exposed to DE (at 200 µg/m(3) of particulate matter) or filtered air (control) for 7 weeks (6 h/day, 5 days/week). The protein and mRNA expression of COX-1 and COX-2 were evaluated by immunohistochemistry analysis and quantitative real-time PCR, respectively. To examine COX activity, thoracic aortae were mounted in a wire myograph, and phenylephrine (PE)-stimulated vasoconstriction was measured with and without the presence of COX antagonists (indomethacin). COX-2 activity was further assessed by urine 2,3-dinor-6-keto PGF(1α) level, a major metabolite of prostacyclin I(2) (PGI(2))., Results: Immunohistochemistry analysis demonstrates that DE exposure enhanced COX-2 expression in both thoracic aorta (p < 0.01) and aortic root (p < 0.03), with no modification of COX-1 expression. The increased COX-2 expression was positively correlated with smooth muscle cell content in aortic lesions (R(2) = 0.4081, p < 0.008). The fractional changes of maximal vasoconstriction in the presence of indomethacin was attenuated by 3-fold after DE exposure (p < 0.02). Urine 2,3-dinor-6-keto PGF(1α) level was 15-fold higher in DE group than the control (p < 0.007). The mRNA expression of COX-2 (p < 0.006) and PGI synthase (p < 0.02), but not COX-1, was significantly augmented after DE exposure., Conclusion: We show that DE inhalation enhanced COX-2 expression, which is also associated with phenotypic changes of aortic lesion.

A dysregulation of the cyclooxygenases and a leukotriene/prostaglandin imbalance are assumed to be part of the pathogenesis of the aspirin (ASA) intolerance syndrome. Ozone is an air pollutant with known proinflammatory effects on exposed epithelia, however, its impact on the expression of the cyclooxygenases 1 and 2 (cox1/2) and prostaglandin E(2) (PGE(2)) in the nasal mucosa is not well known. Therefore, we analyzed cox expression and PGE(2) levels after ozone exposure in nasal mucosa and in nasal polyps considering ASA intolerance. Isolated epithelial nasal cells from control subjects without chronic rhinosinusitis (CRS), and those from patients with nasal polyps with and without ASA intolerance were cultured and exposed in vitro to ozone. Cox1/2 expression levels were analyzed by immunohistochemistry and PGE(2) release by ELISA. After ozone exposure cox1/2 expression remained unchanged in all the three groups. PGE(2) release was lowered in cell cultures from controls and from polyps of ASA tolerant but not in those of ASA intolerant patients after ozone exposure. In the latter, PGE(2) expression remained unchanged. Our in vitro data suggest that aspirin tolerant patients with polyps might be more affected by ozone compared to aspirin intolerant ones. The potential clinical impact of impaired PGE(2) expression caused by ozone on the functions of respiratory epithelia remains to be clarified.

Prostaglandin E(2) (PGE(2)) is a bioactive prostanoid implicated in the inflammatory processes of acute lung injury/acute respiratory distress syndrome. This study investigated whether PGE(2) can induce production of interleukin (IL)-8, the major chemokine for neutrophil activation, from human pulmonary microvascular endothelial cells (HPMVECs). PGE(2) significantly enhanced IL-8 protein production with increases in IL-8 mRNA expression and intracellular cAMP levels. HPMVECs expressed only EP4 receptor mRNA. The PGE(2) effects were mimicked by a selective EP4 receptor agonist, ONO-AE1-329, and inhibited by a selective EP4 receptor antagonist, ONO-AE3-208, or a protein kinase A inhibitor, Rp-adenosine 3',5'-cyclic monophosphorothioate triethylamine salt. The specific agonist for EP1, EP2, or EP3 receptor did not induce IL-8 production. PGE(2)-induced IL-8 production was accompanied by p38 phosphorylation and was significantly inhibited by a p38 inhibitor, SB-203580, but not by an ERK1/2 inhibitor, U-0126, or a JNK inhibitor, SP-600125. Additionally, PGE(2) increased cyclooxygenase-2 expression with no change in constitutive cyclooxygenase-1 expression, suggesting possible involvement of an autocrine or paracrine manner. In conclusion, PGE(2) enhances IL-8 production via EP4 receptor coupled to G(s) protein in HPMVECs. Activation of the cAMP/protein kinase A pathway, followed by p38 activation, is essential for these mechanisms. Because neutrophils play a critical role in the inflammation of acute lung injury/acute respiratory distress syndrome, IL-8 released from the pulmonary microvasculature in response to PGE(2) may contribute to pathophysiology of this disease.

We investigated a family in which the index subject presented with severe congenital lactic acidosis and dysmorphic features associated with a cytochrome c oxidase (COX)-assembly defect and a specific decrease in the synthesis of COX I, the subunit that nucleates COX assembly. Using a combination of microcell-mediated chromosome transfer, homozygosity mapping, and transcript profiling, we mapped the gene defect to chromosome 12 and identified a homozygous missense mutation (c.88G>A) in C12orf62. C12orf62 was not detectable by immunoblot analysis in subject fibroblasts, and retroviral expression of the wild-type C12orf62 cDNA rescued the biochemical phenotype. Furthermore, siRNA-mediated knockdown of C12orf 62 recapitulated the biochemical defect in control cells and exacerbated it in subject cells. C12orf62 is apparently restricted to the vertebrate lineage. It codes for a very small (6 kDa), uncharacterized, single-transmembrane protein that localizes to mitochondria and elutes in a complex of ∼110 kDa by gel filtration. COX I, II, and IV coimmunoprecipated with an epitope-tagged version of C12orf62, and 2D blue-native-polyacrylamide-gel-electrophoresis analysis of newly synthesized mitochondrial COX subunits in subject fibroblasts showed that COX assembly was impaired and that the nascent enzyme complex was unstable. We conclude that C12orf62 is required for coordination of the early steps of COX assembly with the synthesis of COX I., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

The imidazoquinoline derivative 1 was found as a novel mPGES-1 inhibitor. Optimization of 1 led to the identification of the 2-chlorophenyl group at the C(2)-position and the quinolone structure at the C(4)-position. Compound 33, the most potent synthesized compound, showed excellent mPGES-1 inhibition (IC(50)=9.1nM) with high selectivity (>1000-fold) over both COX-1 and COX-2., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: Cyclooxygenase(COX)-2 is implicated in variety of pathophysiological processes, although its role in acute reflux oesophagitis is debatable. This study was designed to evaluate the role of COX-2 during oesophagitis and in melatonin-elicited protection in rats., Methods: Reflux oesophagitis was induced in rats by ligating the pyloric end and the limiting ridge of the stomach for 5 h. Celecoxib (COX-2 blocker; 10 mg/kg), 16,16-dimethyl prostaglandinE(2) (dmPGE(2); a synthetic analogue of PGE(2) ; 10 µg/kg), melatonin (20 and 40 mg/kg) and omeprazole (10 mg/kg) were given intra-peritoneally 45 min before induction of oesophagitis in rats. Alterations in COX-1 and 2 gene expression and protein levels level were analysed via RT-PCR and Western blotting, respectively. Mucosal PGE(2) level and myeloperoxidase (MPO) activity were measured using an enzyme immunoassay (EIA) kit and spectrophotometrically, respectively., Key Findings: COX-2 over-expression during reflux oesophagitis promotes inflammation of the oesophagus as celecoxib pretreatment significantly reduced tissue damage and MPO activity in rats with reflux oesophagitis (RE-rats). By contrast, dmPGE(2) pretreatment significantly exacerbated tissue injury and simultaneously increased COX-2 expression, PGE(2) levels and MPO activity in RE-rats. Further, melatonin pretreatment significantly reduced the tissue injury, COX-2 over-expression, PGE(2) level and MPO activity in RE-rats. Melatonin offered more potent suppression of COX-2, PGE(2) and MPO activity than the proton-pump inhibitor omeprazole; however, both reduced the lesion injury to a similar extent. Melatonin at a dose of 20 mg/kg failed to inhibit significantly the dmPGE(2) -induced tissue damage, COX-2 expression, PGE(2) level and MPO activity in RE-rats while at a higher dose of 40 mg/kg it significantly attenuated these changes., Conclusion: Our results suggest that COX-2 plays an important pro-inflammatory role during acute reflux oesophagitis in rats and its inhibition contributes significantly to melatonin-exerted protection against reflux oesophagitis., (© 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.)

We tested if modulation in mRNA expression of cyclooxygenase isoforms (COX-1 and COX-2) can be related to protective effects of phototherapy in skeletal muscle. Thirty male Wistar rats were divided into five groups receiving either one of four laser doses (0.1, 0.3, 1.0 and 3.0 J) or a no-treatment control group. Laser irradiation (904 nm, 15 mW average power) was performed immediately before the first contraction for treated groups. Electrical stimulation was used to induce six tetanic tibial anterior muscle contractions. Immediately after sixth contraction, blood samples were collected to evaluate creatine kinase activity and muscles were dissected and frozen in liquid nitrogen to evaluate mRNA expression of COX-1 and COX-2. The 1.0 and 3.0 J groups showed significant enhancement (P < 0.01) in total work performed in six tetanic contractions compared with control group. All laser groups, except the 3.0 J group, presented significantly lower post-exercise CK activity than control group. Additionally, 1.0 J group showed increased COX-1 and decreased COX-2 mRNA expression compared with control group and 0.1, 0.3 and 3.0 J laser groups (P < 0.01). We conclude that pre-exercise infrared laser irradiation with dose of 1.0 J enhances skeletal muscle performance and decreases post-exercise skeletal muscle damage and inflammation., (© 2011 The Authors. Photochemistry and Photobiology © 2011 The American Society of Photobiology.)

Background: Human platelets express both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Variation in COX-2 expression could be a mechanism for variable response to aspirin., Hypothesis/objectives: The hypotheses were that circulating canine platelets express COX-1 and COX-2, and that aspirin alters COX expression. The objective was to identify changes in platelet COX expression and in platelet function caused by aspirin administration to dogs., Animals: Eight female, intact hounds., Methods: A single population, repeated measures design was used to evaluate platelet COX-1 and COX-2 expression by flow cytometry before and after aspirin (10 mg/kg Q12h for 10 days). Platelet function was analyzed via PFA-100(®) (collagen/epinephrine), and urine 11-dehydro-thromboxane B(2) (11-dTXB(2)) was measured and normalized to urinary creatinine. Differences in COX expression, PFA-100(®) closure times, and urine 11-dTXB(2 ): creatinine ratio were analyzed before and after aspirin administration., Results: Both COX-1 and COX-2 were expressed in canine platelets. COX-1 mean fluorescent intensity (MFI) increased in all dogs, by 250% (range 63-476%), while COX-2 expression did not change significantly (P = 0.124) after aspirin exposure, with large interindividual variation. PFA-100(®) closure times were prolonged and urine 11-dTXB(2) concentration decreased in all dogs after aspirin administration., Conclusions and Clinical Importance: Canine platelets express both COX isoforms. After aspirin exposure, COX-1 expression increased despite impairment of platelet function, while COX-2 expression varied markedly among dogs. Variability in platelet COX-2 expression should be explored as a potential mechanism for, or marker of, variable aspirin responsiveness., (Copyright © 2011 by the American College of Veterinary Internal Medicine.)