Prostaglandin A1 Inhibits Replication of Classical Swine Fever Virus

Prostaglandins (Pgs) have been shown to inhibit the replication of several DNA and RNA viruses. Here we report the effect of prostaglandin (PgA1) on the multiplication of a positive strand RNA virus, Classical Swine Fever Virus (CSFV) in PK15 cells. PgA1 was found to inhibit the multiplication of CSFV. At a concentration of 5 µg/ml, which was nontoxic to the cells, PgA1 inhibitis virus production in 99%. In PgA1 treated cells the size and number of characteristic Classical Swine Fever focus decreased in amount.

Reactive Nitrogen and Oxygen Intermediates in Patients with Cutaneous Leishmaniasis

The metabolisms of reactive nitrogen and oxygen intermediates (RNI and ROI) in patients with cutaneous leishmaniasis (CL) were investigated and compared with those of healthy subjects. To determine RNI metabolism, nitrite plus nitrate concentrations were measured spectrophotometrically. Nitrite concentration in plasma was determined directly by the Griess method. Nitrate levels in plasma were measured after reduction into nitrite by using copper-cadmium-zinc. ROI metabolism was evaluated by measuring erythrocyte superoxide dismutase, catalase and glutathione peroxidase activities. Plasma nitrite plus nitrate levels and erythrocyte superoxide dismutase activity were higher in the patient group than healthy subjects (p<0.01). In contrast, erythrocyte catalase and glutathione peroxidase activities were lower (p<0.05, p<0.01, respectively). ROI metabolism was altered in relation to hydrogen peroxide elevation in patients with CL. These alterations in ROI enable nitric oxide (NO) to amplify its leishmanicidal effect. The determination of ROI and RNI in patients with CL may be a useful tool to evaluate effector mechanisms of NO and clinical manifestations.

Prostaglandin transporter mutations cause pachydermoperiostosis with myelofibrosis.

Pachydermoperiostosis, or primary hypertrophic osteoarthropathy (PHO), is an inherited multisystem disorder, whose features closely mimic the reactive osteoarthropathy that commonly accompanies neoplastic and inflammatory pathologies. We previously described deficiency of the prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (HPGD) as a cause of this condition, implicating elevated circulating prostaglandin E(2) (PGE(2) ) as causative of PHO, and perhaps also as the principal mediator of secondary HO. However, PHO is genetically heterogeneous. Here, we use whole-exome sequencing to identify recessive mutations of the prostaglandin transporter SLCO2A1, in individuals lacking HPGD mutations. We performed exome sequencing of four probands with severe PHO, followed by conventional mutation analysis of SLCO2A1 in nine others. Biallelic SLCO2A1 mutations were identified in 12 of the 13 families. Affected individuals had elevated urinary PGE(2) , but unlike HPGD-deficient patients, also excreted considerable quantities of the PGE(2) metabolite, PGE-M. Clinical differences between the two groups were also identified, notably that SLCO2A1-deficient individuals have a high frequency of severe anemia due to myelofibrosis. These findings reinforce the key role of systemic or local prostaglandin excess as the stimulus to HO. They also suggest that the induction or maintenance of hematopoietic stem cells by prostaglandin may depend upon transporter activity. Hum Mutat 33:1175-1181, 2012. © 2012 Wiley Periodicals, Inc.

Prostaglandin E2 promotes integrin alpha Vbeta 3-dependent endothelial cell adhesion, rac-activation, and spreading through cAMP/PKA-dependent signaling.

We have recently reported that the inhibition of endothelial cell COX-2 by non-steroidal anti-inflammatory drugs suppresses alpha(V)beta(3)- (but not alpha(5)beta(1)-) dependent Rac activation, endothelial cell spreading, migration, and angiogenesis (Dormond, O., Foletti, A., Paroz, C., and Ruegg, C. (2001) Nat. Med. 7, 1041-1047). Here we investigated the role of the COX-2 metabolites PGE(2) and TXA2 in regulating human umbilical vein endothelial cell (HUVEC) adhesion and spreading. We report that PGE(2) accelerated alpha(V)beta(3)-mediated HUVEC adhesion and promoted Rac activation and cell spreading, whereas the TXA2 agonist retarded adhesion and inhibited spreading. We show that the cAMP level and the cAMP-regulated protein kinase A (PKA) activity are critical mediators of these PGE(2) effects. alpha(V)beta(3)-mediated adhesion induced a transient COX-2-dependent rise in cAMP levels, whereas the cell-permeable cAMP analogue 8-brcAMP accelerated adhesion, promoted Rac activation, and cell spreading in the presence of the COX-2 inhibitor NS-398. Pharmacological inhibition of PKA completely blocked alpha(V)beta(3)-mediated adhesion. A constitutively active Rac mutant (L61Rac) rescued alpha(V)beta(3)-dependent spreading in the presence of NS398 or, but did not accelerate adhesion, whereas a dominant negative Rac mutant (N17Rac) suppressed spreading without affecting adhesion. alpha(5)beta(1)-mediated HUVEC adhesion, Rac activation, and spreading were not affected by PGE(2), 8-brcAMP, or the inhibition of PKA. In conclusion, these results demonstrate that PGE(2) accelerates alpha(V)beta(3)-mediated endothelial cell adhesion through cAMP-dependent PKA activation and induces alpha(V)beta(3)-dependent spreading via cAMP- and PKA-dependent Rac activation and may contribute to the further understanding of the regulation of vascular integrins alpha(V)beta(3) by COX-2/PGE(2) during tumor angiogenesis and inflammation.

Preferential synthesis of prostaglandin D2 by neurons and prostaglandin E2 by fibroblasts and nonneuronal cells in chick dorsal root ganglia.

To determine the type and the relative amount of prostaglandins (PGs) synthesized by various neural tissues, homogenates of meninges, dorsal root ganglia (DRG) capsules, decapsulated DRG, and unsheathed sciatic nerves were incubated with [1-14C]arachidonic acid. Homogenates of cultured cells (meningeal cells, fibroblasts, and nonneuronal or neuronal DRG cells) were used to specify the cells producing particular PGs. The highest synthetic capacity was found in fibroblast-rich tissues (meninges and DRG capsules) and in cultures of meningeal cells or fibroblasts. Two major cyclooxygenase products were formed: [14C]PGE2 and an unusual 14C-labeled compound, Y. The accumulation of compound Y, corresponding probably to 15-hydroperoxy PGE2, was completely impaired by addition of exogenous GSH, which conversely enhanced the synthesis of [14C]PGE2 and promoted the formation of [14C]PGD2. In contrast, decapsulated DRG or unsheathed sciatic nerves displayed a 10-20 times lower capacity to synthesize PGs than fibroblast-rich tissues and produced mainly [14C]PGE2 and [14C]PGD2. In this case, [14C]PGE2 or [14C]PGD2 synthesis was neither enhanced nor promoted by addition of exogenous GSH. Neuron-enriched DRG cell cultures allowed us to specify that [14C]PGD2 is the major prostanoid produced by primary sensory neurons as compared with nonneuronal DRG cells. Because PGD2 synthesis in DRG and more specifically in DRG neurons does not depend on exogenous GSH and differs from PGD2 synthesis in fibroblast-rich tissues, it is concluded that at least two distinct enzymatic processes contribute to PGD2 formation in the nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Futile cycling of intermediates of fatty acid biosynthesis toward peroxisomal beta-oxidation in Saccharomyces cerevisiae.

The flux of fatty acids toward beta-oxidation was analyzed in Saccharomyces cerevisiae by monitoring polyhydroxyalkanoate synthesis in the peroxisome from the polymerization, by a bacterial polyhydroxyalkanoate synthase, of the beta-oxidation intermediates 3-hydroxyacyl-CoAs. Synthesis of polyhydroxyalkanoate was dependent on the beta-oxidation enzymes acyl-CoA oxidase and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase multifunctional protein, which are involved in generating 3-hydroxyacyl-CoAs, and on the peroxin PEX5, which is involved in the import of proteins into the peroxisome. In wild type cells grown in media containing fatty acids, the polyhydroxyalkanoate monomer composition was largely influenced by the nature of the external fatty acid, such that even-chain monomers are generated from oleic acid and odd-chain monomers are generated from heptadecenoic acid. In contrast, polyhydroxyalkanoate containing predominantly 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate was synthesized in a mutant deficient in the peroxisomal 3-ketothiolase (fox3 Delta 0) growing either on oleic acid or heptadecenoic acid as well as in wild type and fox3 Delta 0 mutants grown on glucose or raffinose, indicating that 3-hydroxyacyl-CoAs used for polyhydroxyalkanoate synthesis were generated from the degradation of intracellular short- and medium-chain fatty acids by the beta-oxidation cycle. Inhibition of fatty acid biosynthesis with cerulenin blocked the synthesis of polyhydroxyalkanoate from intracellular fatty acids but still enabled the use of extracellular fatty acids for polymer production. Mutants affected in the synthesis of lipoic acid showed normal polyhydroxyalkanoate synthesis capacity. Together, these results uncovered the existence of a substantial futile cycle whereby short- and medium-chain intermediates of the cytoplasmic fatty acid biosynthetic pathway are directed toward the peroxisomal beta-oxidation pathway.

Effect of olive oil on early and late events of colon carcinogenesis in rats: modulation of arachidonic acid metabolism and local prostaglandin E2 synthesis.

BACKGROUND Animal model studies have shown that the colon tumour promoting effect of dietary fat depends not only on the amount but on its fatty acid composition. With respect to this, the effect of n9 fatty acids, present in olive oil, on colon carcinogenesis has been scarcely investigated. AIMS To assess the effect of an n9 fat diet on precancer events, carcinoma development, and changes in mucosal fatty acid composition and prostaglandin (PG)E2 formation in male Sprague-Dawley rats with azoxymethane induced colon cancer. METHODS Rats were divided into three groups to receive isocaloric diets (5% of the energy as fat) rich in n9, n3, or n6 fat, and were administered azoxymethane subcutaneously once a week for 11 weeks at a dose rate of 7.4 mg/kg body weight. Vehicle treated groups received an equal volume of normal saline. Groups of animals were colectomised at weeks 12 and 19 after the first dose of azoxymethane or saline. Mucosal fatty acids were assessed at 12 and 19 weeks. Aberrant crypt foci and the in vivo intracolonic release of PGE2 were assessed at week 12, and tumour formation at week 19. RESULTS Rats on the n6 diet were found to have colonic aberrant crypt foci and adenocarcinomas more often than those consuming either the n9 or n3 diet. There were no differences between the rats on the n9 and n3 diets. On the other hand, administration of both n9 and n3 diets was associated with a decrease in mucosal arachidonate concentrations as compared with the n6 diet. Carcinogen treatment induced an appreciable increase in PGE2 formation in rats fed the n6 diet, but not in those fed the n3 and n9 diets. CONCLUSIONS Dietary olive oil prevented the development of aberrant crypt foci and colon carcinomas in rats, suggesting that olive oil may have chemopreventive activity against colon carcinogenesis. These effects may be partly due to modulation of arachidonic acid metabolism and local PGE2synthesis.

Effect of selective phosphodiesterase inhibitors on response of ovine pulmonary arteries to prostaglandin E2.

Several adenosine 3',5'-cyclic monophosphate (cAMP)-hydrolyzing phosphodiesterase isozymes are present in the pulmonary vasculature. The present study was designed to determine the effect of selective inhibitors of phosphodiesterase subtypes on prostaglandin E2 (PGE2)-induced relaxation of isolated fourth-generation pulmonary arteries of newborn lambs. PGE2 and forskolin caused pulmonary arteries to relax and induced an increase in the intracellular cAMP content in the vessels. The relaxation and change in cAMP content were augmented by milrinone and rolipram, inhibitors of phosphodiesterase type 3 (PDE3) and type 4 (PDE4), respectively. The augmentation in relaxation and the increase in cAMP content caused by milrinone plus rolipram was greater than the sum of the responses caused by either of the inhibitors alone. 8-Methoxymethyl-1-methyl-3-(2-methylpropyl)xanthine, an inhibitor of phosphodiesterase type 1, had no effect on relaxation and change in cAMP induced by PGE2 and forskolin. Acetylcholine alone had no effect on cAMP content in the vessels but augmented the relaxation and the increase in cAMP induced by PGE2 and forskolin in arteries with endothelium. This effect was not observed in arteries without endothelium or in arteries with endothelium treated with NG-nitro-L-arginine. These results suggest that PDE3 and PDE4 are the primary enzymes hydrolyzing cAMP of pulmonary arteries of newborn lambs and that an inhibition of both PDE3 and PDE4 would result in a greater effect than that caused by inhibition of either one of the subtype isozymes alone. Furthermore, endothelium-derived nitric oxide may enhance cAMP-mediated relaxation by inhibition of PDE3.

Origin of the spectral shifts among the early intermediates of the rhodopsin photocycle.

A combined strategy based on the computation of absorption energies, using the ZINDO/S semiempirical method, for a statistically relevant number of thermally sampled configurations extracted from QM/MM trajectories is used to establish a one-to-one correspondence between the structures of the different early intermediates (dark, batho, BSI, lumi) involved in the initial steps of the rhodopsin photoactivation mechanism and their optical spectra. A systematic analysis of the results based on a correlation-based feature selection algorithm shows that the origin of the color shifts among these intermediates can be mainly ascribed to alterations in intrinsic properties of the chromophore structure, which are tuned by several residues located in the protein binding pocket. In addition to the expected electrostatic and dipolar effects caused by the charged residues (Glu113, Glu181) and to strong hydrogen bonding with Glu113, other interactions such as π-stacking with Ala117 and Thr118 backbone atoms, van der Waals contacts with Gly114 and Ala292, and CH/π weak interactions with Tyr268, Ala117, Thr118, and Ser186 side chains are found to make non-negligible contributions to the modulation of the color tuning among the different rhodopsin photointermediates.

Mining the human phenome using allelic scores that index biological intermediates.

It is common practice in genome-wide association studies (GWAS) to focus on the relationship between disease risk and genetic variants one marker at a time. When relevant genes are identified it is often possible to implicate biological intermediates and pathways likely to be involved in disease aetiology. However, single genetic variants typically explain small amounts of disease risk. Our idea is to construct allelic scores that explain greater proportions of the variance in biological intermediates, and subsequently use these scores to data mine GWAS. To investigate the approach's properties, we indexed three biological intermediates where the results of large GWAS meta-analyses were available: body mass index, C-reactive protein and low density lipoprotein levels. We generated allelic scores in the Avon Longitudinal Study of Parents and Children, and in publicly available data from the first Wellcome Trust Case Control Consortium. We compared the explanatory ability of allelic scores in terms of their capacity to proxy for the intermediate of interest, and the extent to which they associated with disease. We found that allelic scores derived from known variants and allelic scores derived from hundreds of thousands of genetic markers explained significant portions of the variance in biological intermediates of interest, and many of these scores showed expected correlations with disease. Genome-wide allelic scores however tended to lack specificity suggesting that they should be used with caution and perhaps only to proxy biological intermediates for which there are no known individual variants. Power calculations confirm the feasibility of extending our strategy to the analysis of tens of thousands of molecular phenotypes in large genome-wide meta-analyses. We conclude that our method represents a simple way in which potentially tens of thousands of molecular phenotypes could be screened for causal relationships with disease without having to expensively measure these variables in individual disease collections.

Prostaglandin E(2) promotes colorectal adenoma growth via transactivation of the nuclear peroxisome proliferator-activated receptor delta.

Cyclooxygenase-derived prostaglandin E(2) (PGE(2)) is the predominant prostanoid found in most colorectal cancers (CRC) and is known to promote colon carcinoma growth and invasion. However, the key downstream signaling pathways necessary for PGE(2)-induced intestinal carcinogenesis are unclear. Here we report that PGE(2) indirectly transactivates PPARdelta through PI3K/Akt signaling, which promotes cell survival and intestinal adenoma formation. We also found that PGE(2) treatment of Apc(min) mice dramatically increased intestinal adenoma burden, which was negated in Apc(min) mice lacking PPARdelta. We demonstrate that PPARdelta is a focal point of crosstalk between the prostaglandin and Wnt signaling pathways which results in a shift from cell death to cell survival, leading to increased tumor growth.

Synthesis of polyhydroxyalkanoate in the peroxisome of Saccharomyces cerevisiae by using intermediates of fatty acid beta-oxidation.

Medium-chain-length polyhydroxyalkanoates (PHAs) are polyesters having properties of biodegradable thermoplastics and elastomers that are naturally produced by a variety of pseudomonads. Saccharomyces cerevisiae was transformed with the Pseudomonas aeruginosa PHAC1 synthase modified for peroxisome targeting by the addition of the carboxyl 34 amino acids from the Brassica napus isocitrate lyase. The PHAC1 gene was put under the control of the promoter of the catalase A gene. PHA synthase expression and PHA accumulation were found in recombinant S. cerevisiae growing in media containing fatty acids. PHA containing even-chain monomers from 6 to 14 carbons was found in recombinant yeast grown on oleic acid, while odd-chain monomers from 5 to 15 carbons were found in PHA from yeast grown on heptadecenoic acid. The maximum amount of PHA accumulated was 0.45% of the dry weight. Transmission electron microscopy of recombinant yeast grown on oleic acid revealed the presence of numerous PHA inclusions found within membrane-bound organelles. Together, these data show that S. cerevisiae expressing a peroxisomal PHA synthase produces PHA in the peroxisome using the 3-hydroxyacyl coenzyme A intermediates of the beta-oxidation of fatty acids present in the media. S. cerevisiae can thus be used as a powerful model system to learn how fatty acid metabolism can be modified in order to synthesize high amounts of PHA in eukaryotes, including plants.

Influence of misoprostol or prostaglandin E(2) for induction of labor on the incidence of pathological CTG tracing: a randomized trial.

OBJECTIVE: To compare the efficacy and safety of misoprostol (prostaglandin E(1) (PGE(1))) with dinoprostone (prostaglandin E(2) (PGE(2))) for third trimester cervical ripening and labor induction. STUDY DESIGN: Patients requiring induction of labor were randomly assigned to receive either 50 microg of intravaginal misoprostol every 4 h or 0.5 mg of intracervical dinoprostone gel every 6 h. Eligibility criteria included gestation = 36 weeks. Primary outcome was the time interval from induction to delivery; secondary outcomes were mode of delivery, perinatal outcome, and interpretation of cardiotocogram (CTG) records. RESULTS: Two hundred women were randomly enrolled to receive either misoprostol (n = 100) or dinoprostone (n = 100). Time induction-to-delivery at 12, 24 and 48 h and the need for oxytocin were reduced with misoprostol (P < 0.05). Pathological CTG tracing according to FIGO and Melchior scores were more frequent in the misoprostol-treated group (P < 0.001). CONCLUSION: Misoprostol shortened the induction-to-delivery interval, but is associated with a higher incidence of abnormal CTG than prostaglandin E(2).

Lipoxin A₄ prevents the progression of de novo and established endometriosis in a mouse model by attenuating prostaglandin E₂ production and estrogen signaling.

Endometriosis, a leading cause of pelvic pain and infertility, is characterized by ectopic growth of endometrial-like tissue and affects approximately 176 million women worldwide. The pathophysiology involves inflammatory and angiogenic mediators as well as estrogen-mediated signaling and novel, improved therapeutics targeting these pathways are necessary. The aim of this study was to investigate mechanisms leading to the establishment and progression of endometriosis as well as the effect of local treatment with Lipoxin A4 (LXA₄), an anti-inflammatory and pro-resolving lipid mediator that we have recently characterized as an estrogen receptor agonist. LXA₄ treatment significantly reduced endometriotic lesion size and downregulated the pro-inflammatory cytokines IL-1β and IL-6, as well as the angiogenic factor VEGF. LXA₄ also inhibited COX-2 expression in both endometriotic lesions and peritoneal fluid cells, resulting in attenuated peritoneal fluid Prostaglandin E₂ (PGE₂) levels. Besides its anti-inflammatory effects, LXA₄ differentially regulated the expression and activity of the matrix remodeling enzyme matrix metalloproteinase (MMP)-9 as well as modulating transforming growth factor (TGF)-β isoform expression within endometriotic lesions and in peritoneal fluid cells. We also report for first time that LXA₄ attenuated aromatase expression, estrogen signaling and estrogen-regulated genes implicated in cellular proliferation in a mouse model of disease. These effects were observed both when LXA₄ was administered prior to disease induction and during established disease. Collectively, our findings highlight potential targets for the treatment of endometriosis and suggest a pleotropic effect of LXA₄ on disease progression, by attenuating pro-inflammatory and angiogenic mediators, matrix remodeling enzymes, estrogen metabolism and signaling, as well as downstream proliferative pathways.