Sample records for e2 pge2 receptor

  1. Estradiol-17beta, prostaglandin E2 (PGE2), and the PGE2 receptor are involved in PGE2 positive feedback loop in the porcine endometrium.

    PubMed

    Waclawik, Agnieszka; Jabbour, Henry N; Blitek, Agnieszka; Ziecik, Adam J

    2009-08-01

    Before implantation, the porcine endometrium and trophoblast synthesize elevated amounts of luteoprotective prostaglandin estradiol-17beta (E(2)) (PGE(2)). We hypothesized that embryo signal, E(2), and PGE(2) modulate expression of key enzymes in PG synthesis: PG-endoperoxide synthase-2 (PTGS2), microsomal PGE synthase (mPGES-1), PGF synthase (PGFS), and PG 9-ketoreductase (CBR1) as well as PGE(2) receptor (PTGER2 and -4) expression and signaling within the endometrium. We determined the site of action of PGE(2) in endometrium during the estrous cycle and pregnancy. Endometrial tissue explants obtained from gilts (n = 6) on d 11-12 of the estrous cycle were treated with vehicle (control), PGE(2) (100 nM), E(2) (1-100 nm), or phorbol 12-myristate 13-acetate (100 nm, positive control). E(2) increased PGE(2) secretion through elevating expression of mPGES-1 mRNA and PTGS2 and mPGES-1 protein in endometrial explants. By contrast, E(2) decreased PGFS and CBR1 protein expression. E(2) also stimulated PTGER2 but not PTGER4 protein content. PGE(2) enhanced mPGES-1 and PTGER2 mRNA as well as PTGS2, mPGES-1, and PTGER2 protein expression. PGE(2) had no effect on PGFS, CBR1, and PTGER4 expression and PGF(2alpha) release. Treatment of endometrial tissue with PGE(2) increased cAMP production. Cotreatment with PTGER2 antagonist (AH6809) but not PTGER4 antagonist (GW 627368X) inhibited significantly PGE(2)-mediated cAMP production. PTGER2 protein was localized in luminal and glandular epithelium and blood vessels of endometrium and was significantly up-regulated on d 11-12 of pregnancy. Our results suggest that E(2) prevents luteolysis through enzymatic modification of PG synthesis and that E(2), PGE(2), and endometrial PTGER2 are involved in a PGE(2) positive feedback loop in porcine endometrium.

  2. Estradiol-17β, prostaglandin E2 (PGE2) and the prostaglandin E2 receptor are involved in PGE2 positive feedback loop in the porcine endometrium

    PubMed Central

    Waclawik, Agnieszka; Jabbour, Henry N.; Blitek, Agnieszka; Ziecik, Adam J.

    2009-01-01

    Before implantation, the porcine endometrium and trophoblast synthesize elevated amounts of luteoprotective prostaglandin E2 (PGE2). We hypothesized that embryo signal, estradiol-17β (E2) and PGE2 modulate expression of key enzymes in PG synthesis: prostaglandin-endoperoxide synthase-2 (PTGS2), PGE synthase (mPGES-1), PGF synthase (PGFS), and prostaglandin 9-ketoreductase (CBR1); as well as PGE2 receptor (PTGER2 and 4) expression and signaling within the endometrium. We determinated the site of action of PGE2 in endometrium during the estrous cycle and pregnancy. Endometrial tissue explants obtained from gilts (n=6) on days 11-12 of the estrous cycle were treated with vehicle (control), PGE2 (100 nM), E2 (1-100 nM) or phorbol 12-myristate 13-acetate (100 nM, positive control). E2 increased PGE2 secretion through elevating expression of mPGES-1 mRNA and PTGS2 and mPGES-1 protein in endometrial explants. By contrast, E2 decreased PGFS and CBR1 protein expression. E2 also stimulated PTGER2 but not PTGER4 protein content. PGE2 enhanced mPGES-1 and PTGER2 mRNA as well as PTGS2, mPGES-1 and PTGER2 protein expression. PGE2 had no effect on PGFS, CBR1 and PTGER4 expression and PGF2α release. Treatment of endometrial tissue with PGE2 increased cAMP production. Co-treatment with PTGER2 antagonist (AH6809) but not PTGER4 antagonist (GW 627368X) inhibited significantly PGE2-mediated cAMP production. PTGER2 protein was localized in luminal and glandular epithelium and blood vessels of endometrium, and was significantly up-regulated on days 11-12 of pregnancy. Our results suggest that E2, prevents luteolysis through enzymatic modification of PG synthesis and that E2, PGE2 and endometrial PTGER2 are involved in PGE2 positive feedback loop in porcine endometrium. PMID:19359378

  3. EP2 receptors mediate airway relaxation to substance P, ATP, and PGE2.

    PubMed

    Fortner, C N; Breyer, R M; Paul, R J

    2001-08-01

    Substance P (SP) and ATP evoke transient, epithelium-dependent relaxation of constricted mouse tracheal smooth muscle. Relaxation to either SP or ATP is blocked by indomethacin, but the specific eicosanoid(s) involved have not been definitively identified. SP and ATP are reported to release PGE2 from airway epithelium in other species, suggesting PGE2 as a likely mediator in epithelium-dependent airway relaxation. Using mice homozygous for a gene-targeted deletion of the EP2 receptor [EP2(-/-)], one of the PGE2 receptors, we tested the hypothesis that PGE2 is the primary mediator of relaxation to SP or ATP. Relaxation in response to SP or ATP was significantly reduced in tracheas from EP2(-/-) mice. There were no differences between EP2(-/-) and wild-type tracheas in their physical dimensions, contraction to ACh, or relaxation to isoproterenol, thus ruling out any general alterations of smooth muscle function. There were also no differences between EP2(-/-) and wild-type tracheas in basal or stimulated PGE2 production. Exogenous PGE2 produced significantly less relaxation in EP2(-/-) tracheas compared with the wild type. Taken together, this experimental evidence supports the following two conclusions: EP2 receptors are of primary importance in airway relaxation to PGE2 and relaxation to SP or ATP is mediated through PGE2 acting on EP2 receptors.

  4. In vivo intra-luteal implants of prostaglandin (PG) E(1) or E(2) (PGE(1), PGE(2)) prevent luteolysis in cows. I. Luteal weight, circulating progesterone, mRNA for luteal luteinizing hormone (LH) receptor, and occupied and unoccupied luteal receptors for LH.

    PubMed

    Weems, Yoshie S; Arreguin-Arevalo, J Alejandro; Nett, Torrance M; Vann, Rhonda C; Ford, Stephen P; Bridges, Phillip J; Welsh, Thomas H; Lewis, Andrew W; Neuendorff, Don A; Randel, Ronald D; Weems, Charles W

    2011-08-01

    Previously, it was reported that chronic intra-uterine infusion of PGE(1) or PGE(2) every four hours inhibited luteolysis in ewes. However, estradiol-17β or PGE(2) given intra-uterine every 8h did not inhibit luteolysis in heifers, but infusion of estradiol+PGE(2) inhibited luteolysis in heifers. The objective of this experiment was to determine whether and how intra-luteal implants containing PGE(1) or PGE(2) prevent luteolysis in Angus or Brahman cows. On day-13 post-estrus, Angus cows received no intra-luteal implant and corpora lutea were retrieved or Angus and Brahman cows received intra-luteal silastic implants containing Vehicle, PGE(1), or PGE(2) and corpora lutea were retrieved on day-19. Coccygeal blood was collected daily for analysis for progesterone. Breed did not influence the effect of PGE(1) or PGE(2) on luteal mRNA for LH receptors or unoccupied or occupied luteal LH receptors did not differ (P>0.05) so the data were pooled. Luteal weights of Vehicle-treated Angus or Brahman cows from days-13-19 were lower (P<0.05) than those treated with intra-luteal implants containing PGE(1) or PGE(2). Day-13 Angus luteal weights were heavier (P<0.05) than Vehicle-treated Angus cows on day-19 and luteal weights of day-13 corpora lutea were similar (P>0.05) to Angus cows on day-19 treated with intra-luteal implants containing PGE(1) or PGE(2). Profiles of circulating progesterone in Angus or Brahman cows treated with intra-luteal implants containing PGE(1) or PGE(2) differed (P<0.05) from controls, but profiles of progesterone did not differ (P>0.05) between breeds or between cows treated with intra-luteal implants containing PGE(1) or PGE(2). Intra-luteal implants containing PGE(1) or PGE(2) prevented (P<0.05) loss of luteal mRNA for LH receptors and unoccupied or occupied receptors for LH compared to controls. It is concluded that PGE(1) or PGE(2) alone delays luteolysis regardless of breed. We also conclude that either PGE(1) or PGE(2) prevented luteolysis in

  5. PGE2 signaling through the EP4 receptor on fibroblasts upregulates RANKL and stimulates osteolysis.

    PubMed

    Tsutsumi, Ryosuke; Xie, Chao; Wei, Xiaochao; Zhang, Minjie; Zhang, Xinping; Flick, Lisa M; Schwarz, Edward M; O'Keefe, Regis J

    2009-10-01

    Periprosthetic osteolysis is the most common cause of aseptic loosening in total joint arthroplasty. The role of inflammatory mediators such as prostaglandin E2 (PGE2) and osteoclast promoting factors including RANKL in the pathogenesis of osteolysis has been well characterized. However, the PGE2 receptor (EP1, EP2, or EP4), and cell type in which it is expressed, which is responsible for PGE2 induction of RANKL during wear debris-induced osteolysis, has yet to be elucidated. To address this, we used mice genetically deficient in these EP receptors to assess PGE2 and wear debris responses in vitro and in vivo. Wear debris-induced osteolysis and RANKL expression were observed at similar levels in WT, EP1(-/-), and EP2(-/-) mice, indicating that these receptors do not mediate PGE2 signals in this process. A conditional knockout approach was used to eliminate EP4 expression in FSP1(+) fibroblasts that are the predominant source of RANKL. In the absence of EP4, fibroblasts do not express RANKL after stimulation with particles or PGE2, nor do they exhibit high levels of osteoclasts and osteolysis. These results show that periprosthetic fibroblasts are important mediators of osteolysis through the expression of RANKL, which is induced after PGE2 signaling through the EP4 receptor.

  6. PGE2 maintains the tone of the guinea pig trachea through a balance between activation of contractile EP1 receptors and relaxant EP2 receptors

    PubMed Central

    Säfholm, J; Dahlén, S-E; Delin, I; Maxey, K; Stark, K; Cardell, L-O; Adner, M

    2013-01-01

    Background and Purpose The guinea pig trachea (GPT) is commonly used in airway pharmacology. The aim of this study was to define the expression and function of EP receptors for PGE2 in GPT as there has been ambiguity concerning their role. Experimental Approach Expression of mRNA for EP receptors and key enzymes in the PGE2 pathway were assessed by real-time PCR using species-specific primers. Functional studies of GPT were performed in tissue organ baths. Key Results Expression of mRNA for the four EP receptors was found in airway smooth muscle. PGE2 displayed a bell-shaped concentration–response curve, where the initial contraction was inhibited by the EP1 receptor antagonist ONO-8130 and the subsequent relaxation by the EP2 receptor antagonist PF-04418948. Neither EP3 (ONO-AE5-599) nor EP4 (ONO-AE3-208) selective receptor antagonists affected the response to PGE2. Expression of COX-2 was greater than COX-1 in GPT, and the spontaneous tone was most effectively abolished by selective COX-2 inhibitors. Furthermore, ONO-8130 and a specific PGE2 antibody eliminated the spontaneous tone, whereas the EP2 antagonist PF-04418948 increased it. Antagonists of other prostanoid receptors had no effect on basal tension. The relaxant EP2 response to PGE2 was maintained after long-term culture, whereas the contractile EP1 response showed homologous desensitization to PGE2, which was prevented by COX-inhibitors. Conclusions and Implications Endogenous PGE2, synthesized predominantly by COX-2, maintains the spontaneous tone of GPT by a balance between contractile EP1 receptors and relaxant EP2 receptors. The model may be used to study interactions between EP receptors. PMID:22934927

  7. PGE2 released by primary sensory neurons modulates Toll-like receptor 4 activities through an EP4 receptor-dependent process.

    PubMed

    Tse, Kai-Hei; Chow, Kevin B S; Wise, Helen

    2016-04-15

    Exogenous prostaglandin E2 (PGE2) displays mixed regulatory properties with regard to inflammatory gene expression in dorsal root ganglion (DRG) cells. We show here that endogenously-produced nanomolar concentrations of PGE2, such as that generated in response to Toll-like receptor 4 (TLR4) stimulation, inhibits both cyclooxygenase-2 (COX-2) and tumour necrosis factor alpha (TNFα) mRNA expression in DRG cells in an EP4 receptor-dependent manner. DRG neurons appear to be the major source of PGE2 in the DRG and likely serve as both an autocrine and paracrine system for limiting over-activation of both DRG neurons and glial cells in response to TLR4 stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. The anti-inflammatory effects of PGE2 on human lung macrophages are mediated by the EP4 receptor.

    PubMed

    Gill, Sharonjit K; Yao, Yiwen; Kay, Linda J; Bewley, Martin A; Marriott, Helen M; Peachell, Peter T

    2016-11-01

    PGE 2 inhibits cytokine generation from human lung macrophages. However, the EP receptor that mediates this beneficial anti-inflammatory effect of PGE 2 has not been defined. The aim of this study was to identify the EP receptor by which PGE 2 inhibits cytokine generation from human lung macrophages. This was determined by using recently developed EP receptor ligands. The effects of PGE 2 and EP-selective agonists on LPS-induced generation of TNF-α and IL-6 from macrophages were evaluated. The effects of EP 2 -selective (PF-04852946, PF-04418948) and EP 4 -selective (L-161,982, CJ-042794) receptor antagonists on PGE 2 responses were studied. The expression of EP receptor subtypes by human lung macrophages was determined by RT-PCR. PGE 2 inhibited LPS-induced and Streptococcus pneumoniae-induced cytokine generation from human lung macrophages. Analysis of mRNA levels indicated that macrophages expressed EP 2 and EP 4 receptors. L-902,688 (EP 4 receptor-selective agonist) was considerably more potent than butaprost (EP 2 receptor-selective agonist) as an inhibitor of TNF-α generation from macrophages. EP 2 receptor-selective antagonists had marginal effects on the PGE 2 inhibition of TNF-α generation, whereas EP 4 receptor-selective antagonists caused rightward shifts in the PGE 2 concentration-response curves. These studies demonstrate that the EP 4 receptor is the principal receptor that mediates the anti-inflammatory effects of PGE 2 on human lung macrophages. This suggests that EP 4 receptor agonists could be effective anti-inflammatory agents in human lung disease. © 2016 The British Pharmacological Society.

  9. Proteinase-activated receptor-2 stimulates prostaglandin production in keratinocytes: analysis of prostaglandin receptors on human melanocytes and effects of PGE2 and PGF2alpha on melanocyte dendricity.

    PubMed

    Scott, Glynis; Leopardi, Sonya; Printup, Stacey; Malhi, Namrita; Seiberg, Miri; Lapoint, Randi

    2004-05-01

    Prostaglandins (PG) are key mediators of diverse functions in the skin and several reports suggest that PG mediate post-inflammatory pigmentary changes through modulation of melanocyte dendricity and melanin synthesis. The proteinase-activated receptor 2 (PAR-2) is important for skin pigmentation because activation of keratinocyte PAR-2 stimulates uptake of melanosomes through phagocytosis in a Rho-dependent manner. In this report, we show that activation of keratinocyte PAR-2 stimulates release of PGE(2) and PGF(2alpha) and that PGE(2) and PGF(2alpha) act as paracrine factors that stimulate melanocyte dendricity. We characterized the expression of the EP and FP receptors in human melanocytes and show that human melanocytes express EP1 and EP3, and the FP receptor, but not EP2 and EP4. Treatment of melanocytes with EP1 and EP3 receptor agonists resulted in increased melanocyte dendricity, indicating that both EP1 and EP3 receptor signaling contribute to PGE(2)-mediated melanocyte dendricity. Certain EP3 receptor subtypes have been shown to increase adenosine 3',5'-cyclic monophosphate (cAMP) through coupling to Gs, whereas EP1 is known to couple to Gq to activate phospholipase C with elevation in Ca(2+). The cAMP/protein kinase A system is known to modulate melanocyte dendrite formation through modulation of Rac and Rho activity. Neither PGF(2alpha) or PGE(2) elevated cAMP in human melanocytes showing that dendricity observed in response to PGE(2) and PGF(2alpha) is cAMP-independent. Our data suggest that PAR-2 mediates cutaneous pigmentation both through increased uptake of melanosomes by keratinocytes, as well as by release of PGE(2) and PGF(2alpha) that stimulate melanocyte dendricity through EP1, EP3, and FP receptors.

  10. Anti-inflammatory effects of PGE2 in the lung: role of the EP4 receptor subtype.

    PubMed

    Birrell, Mark A; Maher, Sarah A; Dekkak, Bilel; Jones, Victoria; Wong, Sissie; Brook, Peter; Belvisi, Maria G

    2015-08-01

    Asthma and chronic obstructive pulmonary disease (COPD) are chronic inflammatory diseases of the airway. Current treatment options (long acting β-adrenoceptor agonists and glucocorticosteroids) are not optimal as they are only effective in certain patient groups and safety concerns exist regarding both compound classes. Therefore, novel bronchodilator and anti-inflammatory strategies are being pursued. Prostaglandin E2 (PGE2) is an arachidonic acid-derived eicosanoid produced by the lung which acts on four different G-protein coupled receptors (EP1-4) to cause an array of beneficial and deleterious effects. The aim of this study was to identify the EP receptor mediating the anti-inflammatory actions of PGE2 in the lung using a range of cell-based assays and in vivo models. It was demonstrated in three distinct model systems (innate stimulus, lipopolysaccharide (LPS); allergic response, ovalbumin (OVA); inhaled pollutant, cigarette smoke) that mice missing functional EP4 (Ptger4(-/-)) receptors had higher levels of airway inflammation, suggesting that endogenous PGE2 was suppressing inflammation via EP4 receptor activation. Cell-based assay systems (murine and human monocytes/alveolar macrophages) demonstrated that PGE2 inhibited cytokine release from LPS-stimulated cells and that this was mimicked by an EP4 (but not EP1-3) receptor agonist and inhibited by an EP4 receptor antagonist. The anti-inflammatory effect occurred at the transcriptional level and was via the adenylyl cyclase/cAMP/ cAMP-dependent protein kinase (PKA) axis. This study demonstrates that EP4 receptor activation is responsible for the anti-inflammatory activity of PGE2 in a range of disease relevant models and, as such, could represent a novel therapeutic target for chronic airway inflammatory conditions. 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.

  11. Prostaglandin E2 suppresses beta1-integrin expression via E-prostanoid receptor in human monocytes/macrophages.

    PubMed

    Hasegawa, Shunji; Ichiyama, Takashi; Kohno, Fumitaka; Korenaga, Yuno; Ohsaki, Ayami; Hirano, Reiji; Haneda, Yasuhiro; Fukano, Reiji; Furukawa, Susumu

    2010-01-01

    Beta1-integrins mediate cell attachment to different extracellular matrix proteins, intracellular proteins, and intercellular adhesions. Recently, it has been reported that prostaglandin E2 (PGE2) has anti-inflammatory properties such as inhibition of the expression of adhesion molecules or production of chemokines. However, the effect of PGE2 on the expression of beta1-integrin remains unknown. In this study, we investigated the effects of PGE2 on the expression of beta1-integrin in the human monocytic cell line THP-1 and in CD14+ monocytes/macrophages in human peripheral blood. For this, we examined the role of four subtypes of PGE2 receptors and E-prostanoid (EP) receptors on PGE2-mediated inhibition. We found that PGE2 significantly inhibited the expression of beta1-integrin, mainly through EP4 receptors in THP-1 cells and CD14+ monocytes/macrophages in human peripheral blood. We suggest that PGE2 has anti-inflammatory effects, leading to the inhibited expression of beta1-integrin in human monocytes/macrophages, and that the EP4 receptor may play an important role in PGE2-mediated inhibition. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  12. Prostaglandin E/sub 2/ localization and receptor identification within the developing murine secondary palate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jones, J.

    1986-01-01

    Transient elevations in murine secondary palatal adenosine 3',5'-monophosphate (cAMP) levels occur during palate ontogeny. Since palatal processes exposed to dibutyryl cAMP differentiate precociously, increases in palatal cAMP levels are of interest. Prostaglandin E/sub 2/ (PGE/sub 2/), which is synthesized by murine embryonic palate mesenchyme cells (MEPM), regulates cAMP levels in adult tissues via specific membrane bound receptors coupled to adenylate cyclase. Therefore, a PGE/sub 2/ receptor-adenylate cyclase systems was proposed in the developing murine secondary palate. Utilizing a radioligand binding assay, it was determined that murine palatal tissue on day 13 of gestation contained PGE/sub 2/ receptors that were saturable,more » of high affinity and low capacity. Specific (/sup 3/H)-PGE/sub 2/ binding was reversible by 30 min. The order of prostanoid binding affinity at specific PGE/sub 2/ binding sites was E/sub 2/ > F/sub 2//sub ..cap alpha../ > A/sub 2/ > E/sub 1/ = D/sub 2/ indicating specificity of the receptor for PGE/sub 2/. The ability of MEPM cells to respond to PGE/sub 2/ with dose-dependent accumulations of intracellular cAMP demonstrated the functional nature of these binding sites. Analysis of palatal PGE/sub 2/ receptor characteristics on days 12 and 14 of palate development indicated temporal alterations in receptor affinity and density during palate ontogeny.« less

  13. P2X7 receptor-stimulation causes fever via PGE2 and IL-1β release.

    PubMed

    Barberà-Cremades, Maria; Baroja-Mazo, Alberto; Gomez, Ana I; Machado, Francisco; Di Virgilio, Francesco; Pelegrín, Pablo

    2012-07-01

    Prostaglandins (PGs) are important lipid mediators involved in the development of inflammatory associated pain and fever. PGE2 is a well-established endogenous pyrogen activated by proinflammatory cytokine interleukin (IL)-1β. P2X7 receptors (P2X7Rs) expressed by inflammatory cells are stimulated by the danger signal extracellular ATP to activate the inflammasome and release IL-1β. Here we show that P2X7R activation is required for the release of PGE2 and other autacoids independent of inflammasome activation, with an ATP EC(50) for PGE2 and IL-1β release of 1.58 and 1.23 mM, respectively. Furthermore, lack of P2X7R or specific antagonism of P2X7R decreased the febrile response in mice triggered after intraperitoneal LPS or IL-1β inoculation. Accordingly, LPS inoculation caused intraperitoneal ATP accumulation. Therefore, P2X7R antagonists emerge as novel therapeutics for the treatment for acute inflammation, pain and fever, with wider anti-inflammatory activity than currently used cyclooxygenase inhibitors.-Barberà-Cremades, M., Baroja-Mazo, A., Gomez, A. I., Machado, F., Di Virgilio, F., Pelegrín, P. P2X7 receptor-stimulation causes fever via PGE2 and IL-1β release.

  14. Misoprostol, an anti-ulcer agent and PGE2 receptor agonist, protects against cerebral ischemia.

    PubMed

    Li, Jun; Liang, Xibin; Wang, Qian; Breyer, Richard M; McCullough, Louise; Andreasson, Katrin

    2008-06-20

    Induction of COX-2 activity in cerebral ischemia results in increased neuronal injury and infarct size. Recent studies investigating neurotoxic mechanisms of COX-2 demonstrate both toxic and paradoxically protective effects of downstream prostaglandin receptor signaling pathways. We tested whether misoprostol, a PGE(2) receptor agonist that is utilized clinically as an anti-ulcer agent and signals through the protective PGE(2) EP2, EP3, and EP4 receptors, would reduce brain injury in the murine middle cerebral artery occlusion-reperfusion (MCAO-RP) model. Administration of misoprostol, at the time of MCAO or 2h after MCAO, resulted in significant rescue of infarct volume at 24 and 72h. Immunocytochemistry demonstrated dynamic regulation of the EP2 and EP4 receptors during reperfusion in neurons and endothelial cells of cerebral cortex and striatum, with limited expression of EP3 receptor. EP3-/- mice had no significant changes in infarct volume compared to control littermates. Moreover, administration of misoprostol to EP3+/+ and EP3-/- mice showed similar levels of infarct rescue, indicating that misoprostol protection was not mediated through the EP3 receptor. Taken together, these findings suggest a novel function for misoprostol as a protective agent in cerebral ischemia acting via the PGE(2) EP2 and/or EP4 receptors.

  15. Prostaglandin E2 modulates dendritic cell function via EP2 and EP4 receptor subtypes.

    PubMed

    Harizi, Hedi; Grosset, Christophe; Gualde, Norbert

    2003-06-01

    We have reported previously that PGE(2) inhibits dendritic cells (DC) functions. Because E prostanoid receptor (EPR) subtypes involved in this action are unknown, expression and functions of these receptors were examined in DC. Western blot and flow cytometry analyses showed that all EPRs were coexpressed in DC. In a dose-dependent manner, lipopolysaccharide (LPS) enhanced EP(2)R/EP(4)R but not EP(1)R/EP(3)R expressions. NS-398, a cyclooxygenase (COX)-2-selective inhibitor, suppressed LPS-enhanced EP(2)R/EP(4)R expression, suggesting that COX-2-issued prostaglandin E(2) (PGE(2)) modulates DC function through stimulation of specific EPR subtypes. Using selective agonists, we found that butaprost, an EP(2)R agonist, and PGE(1) alcohol, an EP(2)R and EP(2)R/EP(4)R agonist, inhibited major histocompatibility complex class II expression and enhanced interleukin-10 production from DC. However, no effect was observed with sulprostone and 17-phenyl-omega-trinor-PGE(2), selective agonists for EP(1)R and EP(1)R/EP(3)R, respectively. Treatment of DC with dibutyryl cyclic adenosine monophosphate (cAMP), an analog of cAMP, mimics PGE(2)-induced, inhibitory effects. Taken together, our data demonstrate that EP(2)R/EP(4)R are efficient for mediating PGE(2)-induced modulation of DC functions.

  16. PGE2 is a UVR-inducible autocrine factor for human melanocytes that stimulates tyrosinase activation

    PubMed Central

    Starner, Renny J.; McClelland, Lindy; Abdel-Malek, Zalfa; Fricke, Alex; Scott, Glynis

    2013-01-01

    Melanocyte proliferation, dendrite formation, and pigmentation are controlled by paracrine factors, particularly following exposure to ultraviolet radiation (UVR). Little is known about autocrine factors for melanocytes. Prostaglandins activate signaling pathways involved in growth, differentiation and apoptosis. Prostaglandin E2 (PGE2) is the most abundant prostaglandin released by keratinocytes following UVR, and stimulates the formation of dendrites in melanocytes. Synthesis of PGE2 is controlled by cPLA2, which releases arachidonic acid from membranes, and COX-2 and prostaglandin E2 synthases (PGES), which convert arachidonic acid to PGH2 and PGH2 to PGE2, respectively. In this report we show that multiple irradiations of human melanocytes with UVR stimulates tyrosinase activity, independent of expression of a functional melanocortin 1 receptor, suggesting the presence of a non-melanocortin autocrine factor. Irradiation of melanocytes activated cPLA2, the rate-limiting step in eicosanoid synthesis, and stimulated PGE2 secretion. PGE2 increased cAMP production, tyrosinase activity and proliferation in melanocytes. PGE2 binds to four distinct G-protein coupled receptors (EP1–4). We show that EP4 receptor signaling stimulates cAMP production in melanocytes. Conversely, stimulation of the EP3 receptor lowered basal cAMP levels. These data suggest that relative levels or activity of these receptors controls effects of PGE2 on cAMP in melanocytes. The data are the first to identify PGE2 as an UVR-inducible autocrine factor for melanocytes that stimulates tyrosinase activity and proliferation, and to show that EP3 and EP4 receptor signaling have opposing effects on cAMP production, a critical signaling pathway that regulates proliferation and melanogenesis in melanocytes. PMID:20500768

  17. Prostaglandin E2 Regulates Its Own Inactivating Enzyme, 15-PGDH, by EP2 Receptor-Mediated Cervical Cell-Specific Mechanisms

    PubMed Central

    Kishore, A. Hari; Owens, David

    2014-01-01

    Context: Prostaglandins play important roles in parturition and have been used to induce cervical ripening and labor. Prior to cervical ripening at term, 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is highly expressed in the cervix and metabolizes cyclooxygenase-2-mediated increases in active prostaglandin E2 (PGE2) to inactive 15-keto PGE2. At term, 15-PGDH gene expression decreases and PGE2 accumulates, leading to cervical ripening and labor. Previously, we found that the cervical isoform of microphthalmia-associated transcription factor (MiTF-CX) serves as a progestational transcription factor that represses IL-8 and hypoxia-mediated increases in cyclooxygenase-2. Objective: We tested the hypothesis that PGE2 regulates its own inactivation through MiTF-CX. Design: We used human cervical stromal cells to investigate the regulation of 15-PGDH. Setting: This was a laboratory-based study using cells from clinical tissue samples. Main Outcome Measures: We evaluated the mechanisms by which PGE2 regulates 15-PGDH in human cervical stromal cells. Results: PGE2 repressed MiTF-CX and 15-PGDH, whereas ectopic overexpression of MiTF-CX induced 15-PGDH expression levels. Stabilization of HIF-1α by deferoxamine resulted in concomitant down-regulation of MiTF-CX and 15-PGDH. Ectopic overexpression of MiTF-CX abrogated PGE2- and deferoxamine-mediated loss of MiTF-CX and 15-PGDH. PGE2-induced loss of MiTF-CX and 15-PGDH was mediated through prostaglandin E2 receptor (EP2) receptors (PTGER2), but not cAMP. Conclusions: The 15-PGDH gene is a MiTF-CX target gene in cervical stromal cells and is down-regulated by PGE2 through EP2 receptors. The findings suggest that EP2 receptor-specific antagonists may be used as an adjunct to present clinical management for the prevention of preterm cervical ripening and preterm labor. PMID:24471568

  18. The role of PGE2 receptor EP4 in pathologic ocular angiogenesis.

    PubMed

    Yanni, Susan E; Barnett, Joshua M; Clark, Monika L; Penn, John S

    2009-11-01

    PGE(2) binds to PGE(2) receptors (EP(1-4)). The purpose of the present study was to investigate the role of the EP(4) receptor in angiogenic cell behaviors of retinal Müller cells and retinal microvascular endothelial cells (RMECs) and to assess the efficacy of an EP(4) antagonist in rat models of oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (LCNV). Müller cells derived from COX-2-null mice were treated with increasing concentrations of the EP(4) agonist PGE(1)-OH, and wild-type Müller cells were treated with increasing concentrations of the EP(4) antagonist L-161982; VEGF production was assessed. Human RMECs (HRMECs) were treated with increasing concentrations of L-161982, and cell proliferation and tube formation were assessed. Rats subjected to OIR or LCNV were administered L-161982, and the neovascular area was measured. COX-2-null mouse Müller cells treated with increasing concentrations of PGE(1)-OH demonstrated a significant increase in VEGF production (P < or = 0.0165). Wild-type mouse Müller cells treated with increasing concentrations of L-161982 demonstrated a significant decrease in VEGF production (P < or = 0.0291). HRMECs treated with increasing concentrations of L-161982 demonstrated a significant reduction in VEGF-induced cell proliferation (P < or = 0.0033) and tube formation (P < 0.0344). L-161982 treatment significantly reduced pathologic neovascularization in OIR (P < 0.0069) and LCNV (P < or = 0.0329). Preliminary investigation has demonstrated that EP(4) activation or inhibition influences the behaviors of two retinal cell types known to play roles in pathologic ocular angiogenesis. These findings suggest that the EP(4) receptor may be a valuable therapeutic target in neovascular eye disease.

  19. Role of EP2 and EP4 receptors in airway microvascular leak induced by prostaglandin E2.

    PubMed

    Jones, Victoria C; Birrell, Mark A; Maher, Sarah A; Griffiths, Mark; Grace, Megan; O'Donnell, Valerie B; Clark, Stephen R; Belvisi, Maria G

    2016-03-01

    Airway microvascular leak (MVL) involves the extravasation of proteins from post-capillary venules into surrounding tissue. MVL is a cardinal sign of inflammation and an important feature of airway inflammatory diseases such as asthma. PGE2, a product of COX-mediated metabolism of arachidonic acid, binds to four receptors, termed EP1–4. PGE2 has a wide variety of effects within the airway, including modulation of inflammation, sensory nerve activation and airway tone. However, the effect of PGE2 on airway MVL and the receptor/s that mediate this have not been described. Evans Blue dye was used as a marker of airway MVL, and selective EP receptor agonists and antagonists were used alongside EP receptor-deficient mice to define the receptor subtype involved. PGE2 induced significant airway MVL in mice and guinea pigs. A significant reduction in PGE2-induced MVL was demonstrated in Ptger2−/− and Ptger4−/− mice and in wild-type mice pretreated simultaneously with EP2 (PF-04418948) and EP4 (ER-819762) receptor antagonists. In a model of allergic asthma, an increase in airway levels of PGE2 was associated with a rise in MVL; this change was absent in Ptger2−/− and Ptger4−/− mice. PGE2 is a key mediator produced by the lung and has widespread effects according to the EP receptor activated. Airway MVL represents a response to injury and under ‘disease’ conditions is a prominent feature of airway inflammation. The data presented highlight a key role for EP2 and EP4 receptors in MVL induced by PGE2.

  20. Decursinol angelate inhibits PGE2-induced survival of the human leukemia HL-60 cell line via regulation of the EP2 receptor and NFκB pathway

    PubMed Central

    Shehzad, Adeeb; Islam, Salman Ul; Ahn, Eun-Mi; Lee, You Mie; Lee, Young Sup

    2016-01-01

    ABSTRACT Decursinol angelate (DA), an active pyranocoumarin compound from the roots of Angelica gigas, has been reported to possess anti-inflammatory and anti-cancer activities. In a previous study, we demonstrated that prostaglandin E2 (PGE2) plays a survival role in HL-60 cells by protecting them from the induction of apoptosis via oxidative stress. Flow cytometry and Hoechst staining revealed that PGE2 suppresses menadione-induced apoptosis, cell shrinkage, and chromatin condensation, by blocking the generation of reactive oxygen species. Treatment of DA was found to reverse the survival effect of PGE2 as well as restoring the menadione-mediated cleavage of caspase-3, lamin B, and PARP. DA blocked PGE2-induced activation of the EP2 receptor signaling pathway, including the activation of PKA and the phosphorylation of CREB. DA also inhibited PGE2-induced expression of cyclooxygenase-2 and the activation of the Ras/Raf/ Erk pathway, which activates downstream targets for cell survival. Finally, DA greatly reduced the PGE2-induced activation of NF-κB p50 and p65 subunits. These results elucidate a novel mechanism for the regulation of cell survival and apoptosis, and open a gateway for further development and combinatory treatments that can inhibit PGE2 in cancer cells. PMID:27414656

  1. Decursinol angelate inhibits PGE2-induced survival of the human leukemia HL-60 cell line via regulation of the EP2 receptor and NFκB pathway.

    PubMed

    Shehzad, Adeeb; Islam, Salman Ul; Ahn, Eun-Mi; Lee, You Mie; Lee, Young Sup

    2016-09-01

    Decursinol angelate (DA), an active pyranocoumarin compound from the roots of Angelica gigas, has been reported to possess anti-inflammatory and anti-cancer activities. In a previous study, we demonstrated that prostaglandin E2 (PGE2) plays a survival role in HL-60 cells by protecting them from the induction of apoptosis via oxidative stress. Flow cytometry and Hoechst staining revealed that PGE2 suppresses menadione-induced apoptosis, cell shrinkage, and chromatin condensation, by blocking the generation of reactive oxygen species. Treatment of DA was found to reverse the survival effect of PGE2 as well as restoring the menadione-mediated cleavage of caspase-3, lamin B, and PARP. DA blocked PGE2-induced activation of the EP2 receptor signaling pathway, including the activation of PKA and the phosphorylation of CREB. DA also inhibited PGE2-induced expression of cyclooxygenase-2 and the activation of the Ras/Raf/ Erk pathway, which activates downstream targets for cell survival. Finally, DA greatly reduced the PGE2-induced activation of NF-κB p50 and p65 subunits. These results elucidate a novel mechanism for the regulation of cell survival and apoptosis, and open a gateway for further development and combinatory treatments that can inhibit PGE2 in cancer cells.

  2. Prostaglandin E2 regulates Th17 cell differentiation and function through cyclic AMP and EP2/EP4 receptor signaling

    PubMed Central

    Boniface, Katia; Bak-Jensen, Kristian S.; Li, Ying; Blumenschein, Wendy M.; McGeachy, Mandy J.; McClanahan, Terrill K.; McKenzie, Brent S.; Kastelein, Robert A.; de Waal Malefyt, René

    2009-01-01

    Prostaglandins, particularly prostaglandin E2 (PGE2), play an important role during inflammation. This is exemplified by the clinical use of cyclooxygenase 2 inhibitors, which interfere with PGE2 synthesis, as effective antiinflammatory drugs. Here, we show that PGE2 directly promotes differentiation and proinflammatory functions of human and murine IL-17–producing T helper (Th17) cells. In human purified naive T cells, PGE2 acts via prostaglandin receptor EP2- and EP4-mediated signaling and cyclic AMP pathways to up-regulate IL-23 and IL-1 receptor expression. Furthermore, PGE2 synergizes with IL-1β and IL-23 to drive retinoic acid receptor–related orphan receptor (ROR)-γt, IL-17, IL-17F, CCL20, and CCR6 expression, which is consistent with the reported Th17 phenotype. While enhancing Th17 cytokine expression mainly through EP2, PGE2 differentially regulates interferon (IFN)-γ production and inhibits production of the antiinflammatory cytokine IL-10 in Th17 cells predominantly through EP4. Furthermore, PGE2 is required for IL-17 production in the presence of antigen-presenting cells. Hence, the combination of inflammatory cytokines and noncytokine immunomodulators, such as PGE2, during differentiation and activation determines the ultimate phenotype of Th17 cells. These findings, together with the altered IL-12/IL-23 balance induced by PGE2 in dendritic cells, further highlight the crucial role of the inflammatory microenvironment in Th17 cell development and regulation. PMID:19273625

  3. Estrogen Receptor-Related Receptor α Mediates Up-Regulation of Aromatase Expression by Prostaglandin E2 in Prostate Stromal Cells

    PubMed Central

    Miao, Lin; Shi, Jiandang; Wang, Chun-Yu; Zhu, Yan; Du, Xiaoling; Jiao, Hongli; Mo, Zengnan; Klocker, Helmut; Lee, Chung; Zhang, Ju

    2010-01-01

    Estrogen receptor-related receptor α (ERRα) is an orphan member of the nuclear receptor superfamily of transcription factors. ERRα is highly expressed in the prostate, especially in prostate stromal cells. However, little is known about the regulation and function of ERRα, which may contribute to the progression of prostatic diseases. We previously found that prostaglandin E2 (PGE2) up-regulated the expression of aromatase in prostate stromal cells. Here we show that PGE2 also up-regulates the expression of ERRα, which, as a transcription factor, further mediates the regulatory effects of PGE2 on the expression of aromatase. ERRα expression was up-regulated by PGE2 in prostate stromal cell line WPMY-1, which was mediated mainly through the protein kinase A signaling pathway by PGE2 receptor EP2. Suppression of ERRα activity by chlordane (an antagonist of ERRα) or small interfering RNA knockdown of ERRα blocked the increase of expression and promoter activity of aromatase induced by PGE2. Overexpression of ERRα significantly increased aromatase expression and promoter activity, which were further augmented by PGE2. Chromatin immunoprecipitation assay demonstrated that ERRα directly bound to the aromatase promoter in vivo, and PGE2 enhanced the recruitment of ERRα and promoted transcriptional regulatory effects on aromatase expression in WPMY-1. 17β-Estradiol concentration in WPMY-1 medium was up-regulated by ERRα expression, and that was further increased by PGE2. Our results provided evidence that ERRα contributed to local estrogen production by up-regulating aromatase expression in response to PGE2 and provided further insights into the potential role of ERRα in estrogen-related prostatic diseases. PMID:20351196

  4. Synergistic suppression of early phase of adipogenesis by microsomal PGE synthase-1 (PTGES1)-produced PGE2 and aldo-keto reductase 1B3-produced PGF2α.

    PubMed

    Fujimori, Ko; Yano, Mutsumi; Ueno, Toshiyuki

    2012-01-01

    We recently reported that aldo-keto reductase 1B3-produced prostaglandin (PG) F(2α) suppressed the early phase of adipogenesis. PGE(2) is also known to suppress adipogenesis. In this study, we found that microsomal PGE(2) synthase (PGES)-1 (mPGES-1; PTGES1) acted as the PGES in adipocytes and that PGE(2) and PGF(2α) synergistically suppressed the early phase of adipogenesis. PGE(2) production was detected in preadipocytes and transiently enhanced at 3 h after the initiation of adipogenesis of mouse adipocytic 3T3-L1 cells, followed by a quick decrease; and its production profile was similar to the expression of the cyclooxygenase-2 (PTGS2) gene. When 3T3-L1 cells were transfected with siRNAs for any one of the three major PTGESs, i.e., PTGES1, PTGES2 (mPGES-2), and PTGES3 (cytosolic PGES), only PTGES1 siRNA suppressed PGE(2) production and enhanced the expression of adipogenic genes. AE1-329, a PTGER4 (EP4) receptor agonist, increased the expression of the Ptgs2 gene with a peak at 1 h after the initiation of adipogenesis. PGE(2)-mediated enhancement of the PTGS2 expression was suppressed by the co-treatment with L-161982, a PTGER4 receptor antagonist. Moreover, AE1-329 enhanced the expression of the Ptgs2 gene by binding of the cyclic AMP response element (CRE)-binding protein to the CRE of the Ptgs2 promoter; and its binding was suppressed by co-treatment with L-161982, which was demonstrated by promoter luciferase and chromatin immunoprecipitation assays. Furthermore, when 3T3-L1 cells were caused to differentiate into adipocytes in medium containing both PGE(2) and PGF(2α), the expression of the adipogenic genes and the intracellular triglyceride level were decreased to a greater extent than in medium containing either of them, revealing that PGE(2) and PGF(2α) independently suppressed adipogenesis. These results indicate that PGE(2) was synthesized by PTGES1 in adipocytes and synergistically suppressed the early phase of adipogenesis of 3T3-L1 cells in

  5. Synergistic Suppression of Early Phase of Adipogenesis by Microsomal PGE Synthase-1 (PTGES1)-Produced PGE2 and Aldo-Keto Reductase 1B3-Produced PGF2α

    PubMed Central

    Fujimori, Ko; Yano, Mutsumi; Ueno, Toshiyuki

    2012-01-01

    We recently reported that aldo-keto reductase 1B3-produced prostaglandin (PG) F2α suppressed the early phase of adipogenesis. PGE2 is also known to suppress adipogenesis. In this study, we found that microsomal PGE2 synthase (PGES)-1 (mPGES-1; PTGES1) acted as the PGES in adipocytes and that PGE2 and PGF2α synergistically suppressed the early phase of adipogenesis. PGE2 production was detected in preadipocytes and transiently enhanced at 3 h after the initiation of adipogenesis of mouse adipocytic 3T3-L1 cells, followed by a quick decrease; and its production profile was similar to the expression of the cyclooxygenase-2 (PTGS2) gene. When 3T3-L1 cells were transfected with siRNAs for any one of the three major PTGESs, i.e., PTGES1, PTGES2 (mPGES-2), and PTGES3 (cytosolic PGES), only PTGES1 siRNA suppressed PGE2 production and enhanced the expression of adipogenic genes. AE1-329, a PTGER4 (EP4) receptor agonist, increased the expression of the Ptgs2 gene with a peak at 1 h after the initiation of adipogenesis. PGE2-mediated enhancement of the PTGS2 expression was suppressed by the co-treatment with L-161982, a PTGER4 receptor antagonist. Moreover, AE1-329 enhanced the expression of the Ptgs2 gene by binding of the cyclic AMP response element (CRE)-binding protein to the CRE of the Ptgs2 promoter; and its binding was suppressed by co-treatment with L-161982, which was demonstrated by promoter luciferase and chromatin immunoprecipitation assays. Furthermore, when 3T3-L1 cells were caused to differentiate into adipocytes in medium containing both PGE2 and PGF2α, the expression of the adipogenic genes and the intracellular triglyceride level were decreased to a greater extent than in medium containing either of them, revealing that PGE2 and PGF2α independently suppressed adipogenesis. These results indicate that PGE2 was synthesized by PTGES1 in adipocytes and synergistically suppressed the early phase of adipogenesis of 3T3-L1 cells in cooperation with PGF2

  6. Prostaglandin E2 promotes proliferation of skeletal muscle myoblasts via EP4 receptor activation.

    PubMed

    Mo, Chenglin; Zhao, Ruonan; Vallejo, Julian; Igwe, Orisa; Bonewald, Lynda; Wetmore, Lori; Brotto, Marco

    2015-01-01

    We recently demonstrated that conditioned media (CM) from osteocytes enhances myogenic differentiation of myoblasts, suggesting that signaling from bone may be important for skeletal muscle myogenesis. The effect of CM was closely mimicked by prostaglandin E2 (PGE2), a bioactive lipid mediator in various physiological or pathological conditions. PGE2 is secreted at high levels by osteocytes and such secretion is further enhanced under loading conditions. Although four types of receptors, EP1 to EP4, mediate PGE2 signaling, it is unknown whether these receptors play a role in myogenesis. Therefore, in this study, the expression of EPs in mouse primary myoblasts was characterized, followed by examination of their roles in myoblast proliferation by treating myoblasts with PGE2 or specific agonists. All four PGE2 receptor mRNAs were detectable by quantitative real-time PCR (qPCR), but only PGE2 and EP4 agonist CAY 10598 significantly enhance myoblast proliferation. EP1/EP3 agonist 17-phenyl trinor PGE2 (17-PT PGE2) and EP2 agonist butaprost did not have any significant effects. Moreover, treatment with EP4 antagonist L161,982 dose-dependently inhibited myoblast proliferation. These results were confirmed by cell cycle analysis and the gene expression of cell cycle regulators. Concomitant with the inhibition of myoblast proliferation, treatment with L161,982 significantly increased intracellular reactive oxygen species (ROS) levels. Cotreatment with antioxidant N-acetyl cysteine (NAC) or sodium ascorbate (SA) successfully reversed the inhibition of myoblast proliferation and ROS overproduction caused by L161,982. Therefore, PGE2 signaling via the EP4 receptor regulates myogenesis by promoting myoblast proliferation and blocking this receptor results in increased ROS production in myoblasts.

  7. Prostaglandin E2 promotes proliferation of skeletal muscle myoblasts via EP4 receptor activation

    PubMed Central

    Mo, Chenglin; Zhao, Ruonan; Vallejo, Julian; Igwe, Orisa; Bonewald, Lynda; Wetmore, Lori; Brotto, Marco

    2015-01-01

    We recently demonstrated that conditioned media (CM) from osteocytes enhances myogenic differentiation of myoblasts, suggesting that signaling from bone may be important for skeletal muscle myogenesis. The effect of CM was closely mimicked by prostaglandin E2 (PGE2), a bioactive lipid mediator in various physiological or pathological conditions. PGE2 is secreted at high levels by osteocytes and such secretion is further enhanced under loading conditions. Although four types of receptors, EP1 to EP4, mediate PGE2 signaling, it is unknown whether these receptors play a role in myogenesis. Therefore, in this study, the expression of EPs in mouse primary myoblasts was characterized, followed by examination of their roles in myoblast proliferation by treating myoblasts with PGE2 or specific agonists. All four PGE2 receptor mRNAs were detectable by quantitative real-time PCR (qPCR), but only PGE2 and EP4 agonist CAY 10598 significantly enhance myoblast proliferation. EP1/EP3 agonist 17-phenyl trinor PGE2 (17-PT PGE2) and EP2 agonist butaprost did not have any significant effects. Moreover, treatment with EP4 antagonist L161,982 dose-dependently inhibited myoblast proliferation. These results were confirmed by cell cycle analysis and the gene expression of cell cycle regulators. Concomitant with the inhibition of myoblast proliferation, treatment with L161,982 significantly increased intracellular reactive oxygen species (ROS) levels. Cotreatment with antioxidant N-acetyl cysteine (NAC) or sodium ascorbate (SA) successfully reversed the inhibition of myoblast proliferation and ROS overproduction caused by L161,982. Therefore, PGE2 signaling via the EP4 receptor regulates myogenesis by promoting myoblast proliferation and blocking this receptor results in increased ROS production in myoblasts. PMID:25785867

  8. A positive feedback loop between progesterone and microsomal prostaglandin E synthase-1-mediated PGE2 promotes production of both in mouse granulosa cells.

    PubMed

    Tamura, Kazuhiro; Naraba, Hiroaki; Hara, Takahiko; Nakamura, Kota; Yoshie, Mikihiro; Kogo, Hiroshi; Tachikawa, Eiichi

    2016-03-01

    Microsomal prostaglandin E synthase-1 (mPGES-1) is primarily expressed in granulosa cells (GCs) in the preovulatory follicle. Both prostaglandin E2 (PGE2) and progesterone (P4) are implicated in various reproductive functions. Here, we demonstrate that mPges-1 may be a direct downstream target gene of the P4 receptor and P4-stimulated PGE2 secretion can stimulate P4 production in a newly generated mouse GC line (GtsT). Treatment of GtsT cells with a P4 receptor agonist, norgestrel, markedly increased mPGES-1 expression detected by RT-PCR analysis. PGE2 secretion measured by an enzyme-linked immunosorbent assay was enhanced by P4 treatment. Luciferase assays revealed that the proximal promoter region of the mPges-1 gene was responsible for the effects of P4 treatment. Conversely, PGE2 treatment stimulated P4 secretion, which coordinated with mRNA expression of steroidogenic acute regulatory protein. Taken together, P4 may regulate mPGES-1 expression to increase PGE2 secretion and in turn P4 production. An autocrine loop between P4 and PGE2 might function to maintain the increased levels of both in GCs. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Prostaglandin E(2) stimulates glutamate receptor-dependent astrocyte neuromodulation in cultured hippocampal cells.

    PubMed

    Sanzgiri, R P; Araque, A; Haydon, P G

    1999-11-05

    Recent Ca(2+) imaging studies in cell culture and in situ have shown that Ca(2+) elevations in astrocytes stimulate glutamate release and increase neuronal Ca(2+) levels, and that this astrocyte-neuron signaling can be stimulated by prostaglandin E(2) (PGE(2)). We investigated the electrophysiological consequences of the PGE(2)-mediated astrocyte-neuron signaling using whole-cell recordings on cultured rat hippocampal cells. Focal application of PGE(2) to astrocytes evoked a Ca(2+) elevation in the stimulated cell by mobilizing internal Ca(2+) stores, which further propagated as a Ca(2+) wave to neighboring astrocytes. Whole-cell recordings from neurons revealed that PGE(2) evoked a slow inward current in neurons adjacent to astrocytes. This neuronal response required the presence of an astrocyte Ca(2+) wave and was mediated through both N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors. Taken together with previous studies, these data demonstrate that PGE(2)-evoked Ca(2+) elevations in astrocyte cause the release of glutamate which activates neuronal ionotropic receptors. Copyright 1999 John Wiley & Sons, Inc.

  10. Injured nerve-derived COX2/PGE2 contributes to the maintenance of neuropathic pain in aged rats.

    PubMed

    Ma, Weiya; Chabot, Jean-Guy; Vercauteren, Freya; Quirion, Remi

    2010-07-01

    Neuropathic pain (NeP) is a debilitating disease afflicting mostly the aged population. Inflammatory responses in injured nerves play a pivotal role in the pathogenesis of NeP. Injured nerve derived cyclooxygenase 2/prostaglandin E2 (COX2/PGE2) contributes to the genesis of NeP at the early stage in young rats. Here we show that COX2/PGE2 is involved in the maintenance of NeP at a chronic stage in aged rats. Eighteen months after partial sciatic nerve ligation (PSNL), NeP remained prominent in aged rats. COX2 expressing macrophages and PGE2 levels were increased in injured nerves. PGE2 receptors (EP1 and EP4) and pain-related ion channel transient receptor potential vanilloid-1 (TRPV1) were increased in the ipsilateral dorsal root ganglion (DRG) neurons of aged PSNL rats. Perineural injection of a selective COX2 inhibitor NS-398 relieved NeP, reversed PSNL increased expression of EP1, EP4 and TRPV1 and suppressed the levels of pain-related peptide substance P and calcitonin gene-related peptide in DRG neurons. These data suggest that injured nerve-derived PGE2 contributes to the maintenance of NeP at the chronic stage in aged rats. Chronically facilitating the synthesis of pain-related molecules in nociceptive DRG neurons is a novel mechanism underpinning the contribution of PGE2. Copyright 2008 Elsevier Inc. All rights reserved.

  11. Prostaglandin E2 (PGE2) and risedronate was superior to PGE2 alone in maintaining newly added bone in the cortical bone site after withdrawal in older intact rats

    NASA Technical Reports Server (NTRS)

    Ma, Y. F.; Lin, B. Y.; Jee, W. S.; Lin, C. H.; Chen, Y. Y.; Ke, H. Z.; Li, X. J.

    1997-01-01

    The objects of this study were (1) to determine the effects of risedronate (Ris) and prostaglandin E2 (PGE2) alone and in combination, on tibial diaphyses of older intact female rats; and (2) to observe the fate of any extra bone if formed after withdrawal of the treatment. Nine-month-old female Sprague-Dawley rats were treated with 6 mg of PGE2/kg/day, 1 or 5 micrograms of Ris/kg twice a week, or 6 mg of PGE2/kg/day plus 1 or 5 micrograms of Ris/kg twice a week for the first 60 days and followed by vehicle injections for another 60 days. Cross-sections of double fluorescent labeled, undecalcified tibial diaphyses proximal to the tibiofibular junction were processed for histomorphometry. We found that: (1) neither the 1 microgram nor the 5 micrograms of Ris treatment in the 60-day on/60-day off group showed any histomorphometric differences from age-related controls; (2) while the 60 days of PGE2 treatment added extra cortical bone (6%) on the tibial shaft (due to stimulation of periosteal, endocortical, and marrow trabecular bone formation), the new endocortical and most of the new marrow trabecular bone were lost when treatment was withdrawn; however, the new periosteal bone remained; (3) PGE2 with Ris added the same amount of new bone to tibial diaphysis as did PGE2 alone and upon withdrawal, new marrow trabecular bone was lost but new periosteal and endocortical bones were preserved in PGE2 + 1 microgram of Ris on/off group. In contrast, all the new bone was maintained in the PGE2 + 5 micrograms of Ris on/off group; (4) PGE2 + Ris cotreatment failed to block the increase in cortical bone porosity induced by PGE2; and (5) in the PGE2 alone and PGE2 + 1 microgram of Ris on/off groups bone turnover was higher than that in the PGE2 + 5 micrograms of Ris on/off group. These results indicate that on/off treatment with PGE2 and Ris is superior to PGE2 alone in that it forms the same amount of new bone during treatment, but preserves more cortical bone during

  12. PGE2/EP3/SRC signaling induces EGFR nuclear translocation and growth through EGFR ligands release in lung adenocarcinoma cells

    PubMed Central

    Bazzani, Lorenzo; Donnini, Sandra; Finetti, Federica; Christofori, Gerhard; Ziche, Marina

    2017-01-01

    Prostaglandin E2 (PGE2) interacts with tyrosine kinases receptor signaling in both tumor and stromal cells supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, A549 and GLC82, PGE2 promotes nuclear translocation of epidermal growth factor receptor (nEGFR), affects gene expression and induces cell growth. Indeed, cyclin D1, COX-2, iNOS and c-Myc mRNA levels are upregulated following PGE2 treatment. The nuclear localization sequence (NLS) of EGFR as well as its tyrosine kinase activity are required for the effect of PGE2 on nEGFR and downstream signaling activities. PGE2 binds its bona fide receptor EP3 which by activating SRC family kinases, induces ADAMs activation which, in turn, releases EGFR-ligands from the cell membrane and promotes nEGFR. Amphiregulin (AREG) and Epiregulin (EREG) appear to be involved in nEGFR promoted by the PGE2/EP3-SRC axis. Pharmacological inhibition or silencing of the PGE2/EP3/SRC-ADAMs signaling axis or EGFR ligands i.e. AREG and EREG expression abolishes nEGFR induced by PGE2. In conclusion, PGE2 induces NSCLC cell proliferation by EP3 receptor, SRC-ADAMs activation, EGFR ligands shedding and finally, phosphorylation and nEGFR. Since nuclear EGFR is a hallmark of cancer aggressiveness, our findings reveal a novel mechanism for the contribution of PGE2 to tumor progression. PMID:28415726

  13. Prostaglandin metabolising enzymes and PGE2 are inversely correlated with vitamin D receptor and 25(OH)2D3 in breast cancer.

    PubMed

    Thill, Marc; Fischer, Dorothea; Hoellen, Friederike; Kelling, Katharina; Dittmer, Christine; Landt, Solveig; Salehin, Darius; Diedrich, Klaus; Friedrich, Michael; Becker, Steffi

    2010-05-01

    Breast cancer is associated with inflammatory processes based on an up-regulation of cyclooxygenase-2 (COX-2) expression. The antiproliferative effects of calcitriol (1,25(OH)(2)D(3)) mediated via the vitamin D receptor (VDR) render vitamin D a promising target in breast cancer therapy. First data suggest a correlation between vitamin D and prostaglandin metabolism. We determined the expression of VDR, COX-2, 15-PGDH and the prostaglandin receptors EP(2)/EP(4) in normal and malignant breast tissue by real-time PCR and Western blot analysis, as well as 25(OH)(2)D(3) and PGE(2) plasma levels from healthy and breast cancer patients. Significantly higher COX-2, lower VDR and lower EP(2) and EP(4) receptor protein levels in the malignant tissue and a significantly lower 15-PGDH protein level in normal breast tissue were detected. Breast cancer patients older than 45 years, diagnosed and sampled in the winter time had significantly lower 25(OH)(2)D(3) and higher PGE(2) serum levels. The inverse correlation between VDR and both COX-2 and 15-PGDH, as well as between PGE(2) and 25(OH)(2)D(3) levels, suggests a possible link between VDR-associated target genes and prostaglandin metabolism.

  14. Regulation by PGE2 of IL-2, IL-3 and IFN production by cortico-resistant thymocytes.

    PubMed

    Daculsi, R; Vaillier, D; Gualde, N

    1993-11-01

    We have investigated the role of prostaglandin E2 (PGE2) in the regulation of cytokine release (IL-2, IL-3 and IFN) by cortico-resistant thymocytes (CRT) stimulated or not through the T-cell antigen receptor by an anti-CD3 monoclonal antibody (mAb). CRT were found to spontaneously produce IL-2 and IL-3 on day 4 of culture, but not IFN. After activation with an anti-CD3 mAb, the maximal levels for IL-2 and IFN were observed on day 1 and for IL-3 on day 4. Addition of PGE2 inhibits IL-2 production and has no effect on IFN production. Indomethacin, an inhibitor of the cyclooxygenase pathway, enhanced both IL-2 and IFN production. In contrast, IL-3 secretion by anti-CD3 activated CRT was up-regulated by PGE2, and its level was decreased in the presence of indomethacin in both stimulated or unstimulated cells. As has been observed with PGE2, forskolin which activates adenylate cyclase increases the IL-3 level. Thus PGE2 may interfere in the process of thymocyte proliferation and/or differentiation by regulating differentially the interleukin production.

  15. Cox-2-derived PGE2 induces Id1-dependent radiation resistance and self-renewal in experimental glioblastoma.

    PubMed

    Cook, Peter J; Thomas, Rozario; Kingsley, Philip J; Shimizu, Fumiko; Montrose, David C; Marnett, Lawrence J; Tabar, Viviane S; Dannenberg, Andrew J; Benezra, Robert

    2016-10-01

    In glioblastoma (GBM), Id1 serves as a functional marker for self-renewing cancer stem-like cells. We investigated the mechanism by which cyclooxygenase-2 (Cox-2)-derived prostaglandin E2 (PGE2) induces Id1 and increases GBM self-renewal and radiation resistance. Mouse and human GBM cells were stimulated with dimethyl-PGE2 (dmPGE2), a stabilized form of PGE2, to test for Id1 induction. To elucidate the signal transduction pathway governing the increase in Id1, a combination of short interfering RNA knockdown and small molecule inhibitors and activators of PGE2 signaling were used. Western blotting, quantitative real-time (qRT)-PCR, and chromatin immunoprecipitation assays were employed. Sphere formation and radiation resistance were measured in cultured primary cells. Immunohistochemical analyses were carried out to evaluate the Cox-2-Id1 axis in experimental GBM. In GBM cells, dmPGE2 stimulates the EP4 receptor leading to activation of ERK1/2 MAPK. This leads, in turn, to upregulation of the early growth response1 (Egr1) transcription factor and enhanced Id1 expression. Activation of this pathway increases self-renewal capacity and resistance to radiation-induced DNA damage, which are dependent on Id1. In GBM, Cox-2-derived PGE2 induces Id1 via EP4-dependent activation of MAPK signaling and the Egr1 transcription factor. PGE2-mediated induction of Id1 is required for optimal tumor cell self-renewal and radiation resistance. Collectively, these findings identify Id1 as a key mediator of PGE2-dependent modulation of radiation response and lend insight into the mechanisms underlying radiation resistance in GBM patients. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Molecular cloning and characterization of chicken prostaglandin E receptor subtypes 2 and 4 (EP2 and EP4).

    PubMed

    Kwok, Amy Ho Yan; Wang, Yajun; Wang, Crystal Ying; Leung, Frederick C

    2008-06-01

    Prostaglandin E(2) (PGE(2)) is an important chemical mediator responsible for regulation of many vital physiological processes. Four receptor subtypes have been identified to mediate its biological actions. Among these subtypes, prostaglandin E receptor subtypes 2 and 4 (EP(2) and EP(4)), both coupled to cAMP-protein kinase A (cAMP-PKA) signaling pathway, are proposed to play crucial roles under both physiological and pathological conditions. Though both receptors were extensively studied in mammals, little is known about their functionality and expression in non-mammalian species including chicken. In present study, the full-length cDNAs for chicken EP(2) and EP(4) receptors were first cloned from adult chicken ovary and testis, respectively. Chicken EP(2) is 356 amino acids in length and shows high amino acid identity to that of human (61%), mouse (63%), and rat (61%). On the other hand, the full-length cDNA of EP(4) gene encodes a precursor of 475 amino acids with a high degree of amino acid identity to that of mammals, including human (87%), mouse (86%), rat (84%), dog (85%), and cattle (83%), and a comparatively lower sequence identity to zebrafish (52%). RT-PCR assays revealed that EP(2) mRNA was expressed in all tissues examined including the oviduct, while EP(4) expression was detected only in a few tissues. Using the pGL3-CRE-luciferase reporter system, we also demonstrated that PGE(2) could induce luciferase activity in DF-1 cells expressing EP(2) and EP(4) in dose-dependent manners (EC(50): <1 nM), confirming that both receptors could be activated by PGE(2) and functionally coupled to the cAMP-PKA signaling pathway. Together, our study establishes a molecular basis to understand the physiological roles of PGE(2) in target tissues of chicken.

  17. Genetic deletion of the P2Y2 receptor offers significant resistance to development of lithium-induced polyuria accompanied by alterations in PGE2 signaling.

    PubMed

    Zhang, Yue; Pop, Ioana L; Carlson, Noel G; Kishore, Bellamkonda K

    2012-01-01

    Lithium (Li)-induced polyuria is due to resistance of the medullary collecting duct (mCD) to the action of arginine vasopressin (AVP), apparently mediated by increased production of PGE(2). We previously reported that the P2Y(2) receptor (P2Y(2)-R) antagonizes the action of AVP on the mCD and may play a role in Li-induced polyuria by enhancing the production of PGE(2) in mCD. Hence, we hypothesized that genetic deletion of P2Y(2)-R should ameliorate Li-induced polyuria. Wild-type (WT) or P2Y(2)-R knockout (KO) mice were fed normal or Li-added diets for 14 days and euthanized. Li-induced polyuria, and decreases in urine osmolality and AQP2 protein abundance in the renal medulla, were significantly less compared with WT mice despite the lack of differences in Li intake or terminal serum or inner medullary tissue Li levels. Li-induced increased urinary excretion of PGE(2) was not affected in KO mice. However, prostanoid EP(3) receptor (EP3-R) protein abundance in the renal medulla of KO mice was markedly lower vs. WT mice, irrespective of the dietary regimen. The protein abundances of other EP-Rs were not altered across the groups irrespective of the dietary regimen. Ex vivo stimulation of mCD with PGE(2) generated significantly more cAMP in Li-fed KO mice (130%) vs. Li-fed WT mice (100%). Taken together, these data suggest 1) genetic deletion of P2Y(2)-R offers significant resistance to the development of Li-induced polyuria; and 2) this resistance is apparently due to altered PGE(2) signaling mediated by a marked decrease in EP3-R protein abundance in the medulla, thus attenuating the EP3-mediated decrease in cAMP levels in mCD.

  18. MDMA Increases Excitability in the Dentate Gyrus: Role of 5HT2A Receptor Induced PGE2 Signaling

    PubMed Central

    Collins, Stuart A.; Huff, Courtney; Chiaia, Nicolas; Gudelsky, Gary A.; Yamamoto, Bryan K.

    2015-01-01

    MDMA is a widely abused psychostimulant which causes release of serotonin in various forebrain regions. Recently, we reported that MDMA increases extracellular glutamate concentrations in the dentate gyrus, via activation of 5HT2A receptors. We examined the role of prostaglandin signaling in mediating the effects of 5HT2A receptor activation on the increases in extracellular glutamate and the subsequent long-term loss of parvalbumin interneurons in the dentate gyrus caused by MDMA. Administration of MDMA into the dentate gyrus of rats increased PGE2 concentrations which was prevented by coadministration of MDL100907, a 5HT2A receptor antagonist. MDMA-induced increases in extracellular glutamate were inhibited by local administration of SC-51089, an inhibitor of the EP1 prostaglandin receptor. Systemic administration of SC-51089 during injections of MDMA prevented the decreases in parvalbumin interneurons observed 10 days later. The loss of parvalbumin immunoreactivity after MDMA exposure coincided with a decrease in paired-pulse inhibition and afterdischarge threshold in the dentate gyrus. These changes were prevented by inhibition of EP1 and 5HT2A receptors during MDMA. Additional experiments revealed an increased susceptibility to kainic acid-induced seizures in MDMA treated rats which could be prevented with SC51089 treatments during MDMA exposure. Overall, these findings suggest that 5HT2A receptors mediate MDMA-induced PGE2 signaling and subsequent increases in glutamate. This signaling mediates parvalbumin cell losses as well as physiologic changes in the dentate gyrus, suggesting that the lack of the inhibition provided by these neurons increases the excitability within the dentate gyrus of MDMA treated rats. PMID:26670377

  19. Interaction of prostanoid EP3 and TP receptors in guinea-pig isolated aorta: contractile self-synergism of 11-deoxy-16,16-dimethyl PGE2

    PubMed Central

    Jones, RL; Woodward, DF

    2011-01-01

    BACKGROUND AND PURPOSE Surprisingly high contractile activity was reported for 11-deoxy-16,16-dimethyl prostaglandin E2 (DX-DM PGE2) on pig cerebral artery when used as a selective EP3 receptor agonist. This study investigated the selectivity profile of DX-DM PGE2, focusing on the interaction between its EP3 and TP (thromboxane A2-like) agonist activities. EXPERIMENTAL APPROACH Contraction of guinea-pig trachea (EP1 system) and aorta (EP3 and TP systems) was measured in conventional organ baths. KEY RESULTS Strong contraction of guinea-pig aorta to sulprostone and 17-phenyl PGE2 (EP3 agonists) was only seen under priming with a second contractile agent such as phenylephrine, histamine or U-46619 (TP agonist). In contrast, DX-DM PGE2 induced strong contraction, which on the basis of treatment with (DG)-3ap (EP3 antagonist) and/or BMS-180291 (TP antagonist) was attributed to self-synergism arising from co-activation of EP3 and TP receptors. EP3/TP self-synergism also accounted for contraction induced by PGF2α and its analogues (+)-cloprostenol and latanoprost-FA. DX-DM PGE2 also showed significant EP1 agonism on guinea-pig trachea as defined by the EP1 antagonists SC-51322, (ONO)-5-methyl-1 and AH-6809, although AH-6809 exhibited poor specificity at concentrations ≥3 µM. CONCLUSIONS AND IMPLICATIONS EP3/TP self-synergism, as seen with PGE/PGF analogues in this study, may confound EP3 agonist potency comparisons and the characterization of prostanoid receptor systems. The competitive profile of a TP antagonist may be distorted by variation in the silent/overt contraction profile of the EP3 system in different studies. The relevance of self-synergism to in vivo actions of natural prostanoid receptor agonists is discussed. PMID:20955363

  20. Mapping PTGERs to the Ovulatory Follicle: Regional Responses to the Ovulatory PGE2 Signal1

    PubMed Central

    Kim, Soon Ok; Duffy, Diane M.

    2016-01-01

    Prostaglandin E2 (PGE2) is a key intrafollicular mediator of ovulation in many, if not all, mammalian species. PGE2 acts at follicular cells via four distinct PGE2 receptors (PTGERs). Within the ovulatory follicle, each cell type (e.g., oocyte, cumulus granulosa cell, mural granulosa cell, theca cell, endothelial cell) expresses a different subset of the four PTGERs. Expression of a subset of PTGERs has consequences for the generation of intracellular signals and ultimately the unique functions of follicular cells that respond to PGE2. Just as the ovulatory LH surge regulates PGE2 synthesis, the LH surge also regulates expression of the four PTGERs. The pattern of expression of the four PTGERs among follicular cells before and after the LH surge forms a spatial and temporal map of PGE2 responses. Differential PTGER expression, coupled with activation of cell-specific intracellular signals, may explain how a single paracrine mediator can have pleotropic actions within the ovulatory follicle. Understanding the role of each PTGER in ovulation may point to previously unappreciated opportunities to both promote and prevent fertility. PMID:27307073

  1. Prostaglandin E2 mediates growth arrest in NFS-60 cells by down-regulating interleukin-6 receptor expression.

    PubMed

    de Silva, Kumudika I; Daud, Asif N; Deng, JiangPing; Jones, Stephen B; Gamelli, Richard L; Shankar, Ravi

    2003-02-15

    Interleukin-6 (IL-6), a potent myeloid mitogen, and the immunosuppressive prostanoid prostaglandin E2 (PGE2) are elevated following thermal injury and sepsis. We have previously demonstrated that bone marrow myeloid commitment shifts toward monocytopoiesis and away from granulocytopoiesis during thermal injury and sepsis and that PGE2 plays a central role in this alteration. Here we investigated whether PGE2 can modulate IL-6-stimulated growth in the promyelocytic cell line, NFS-60, by down-regulating IL-6 receptor (IL-6r) expression. Exposure of NFS-60 cells to PGE2 suppressed IL-6-stimulated proliferation as well as IL-6r expression. Receptor down-regulation is functionally significant since IL-6-induced signal transduction through activators of transcription (STAT)-3 is also decreased. Down-regulation of IL-6r correlated with the ability of PGE2 to arrest cells in the G0/G1 phase of the cell cycle. PGE2 appears to signal through EP2 receptors. Butaprost (EP2 agonist) but not sulprostone (EP3 agonist) inhibited IL-6-stimulated proliferation. In addition, an EP2 antagonist (AH6809) alleviated the anti-proliferative effects of PGE2. NFS-60 cells express predominantly EP2 and EP4 receptors. While PGE2 down-regulated both the IL-6r protein and mRNA expression, it had no influence on EP2 or EP4 mRNA expression. The present study demonstrates that PGE2 is a potent down-regulator of IL-6r expression and thus may provide a mechanistic explanation for the granulocytopenia seen in thermal injury and sepsis.

  2. Vasopressin-independent targeting of aquaporin-2 by selective E-prostanoid receptor agonists alleviates nephrogenic diabetes insipidus

    PubMed Central

    Olesen, Emma T. B.; Rützler, Michael R.; Moeller, Hanne B.; Praetorius, Helle A.; Fenton, Robert A.

    2011-01-01

    In the kidney, the actions of vasopressin on its type-2 receptor (V2R) induce increased water reabsorption alongside polyphosphorylation and membrane targeting of the water channel aquaporin-2 (AQP2). Loss-of-function mutations in the V2R cause X-linked nephrogenic diabetes insipidus. Treatment of this condition would require bypassing the V2R to increase AQP2 membrane targeting, but currently no specific pharmacological therapy is available. The present study examined specific E-prostanoid receptors for this purpose. In vitro, prostaglandin E2 (PGE2) and selective agonists for the E-prostanoid receptors EP2 (butaprost) or EP4 (CAY10580) all increased trafficking and ser-264 phosphorylation of AQP2 in Madin-Darby canine kidney cells. Only PGE2 and butaprost increased cAMP and ser-269 phosphorylation of AQP2. Ex vivo, PGE2, butaprost, or CAY10580 increased AQP2 phosphorylation in isolated cortical tubules, whereas PGE2 and butaprost selectively increased AQP2 membrane accumulation in kidney slices. In vivo, a V2R antagonist caused a severe urinary concentrating defect in rats, which was greatly alleviated by treatment with butaprost. In conclusion, EP2 and EP4 agonists increase AQP2 phosphorylation and trafficking, likely through different signaling pathways. Furthermore, EP2 selective agonists can partially compensate for a nonfunctional V2R, providing a rationale for new treatment strategies for hereditary nephrogenic diabetes insipidus. PMID:21768374

  3. Vasopressin-independent targeting of aquaporin-2 by selective E-prostanoid receptor agonists alleviates nephrogenic diabetes insipidus.

    PubMed

    Olesen, Emma T B; Rützler, Michael R; Moeller, Hanne B; Praetorius, Helle A; Fenton, Robert A

    2011-08-02

    In the kidney, the actions of vasopressin on its type-2 receptor (V2R) induce increased water reabsorption alongside polyphosphorylation and membrane targeting of the water channel aquaporin-2 (AQP2). Loss-of-function mutations in the V2R cause X-linked nephrogenic diabetes insipidus. Treatment of this condition would require bypassing the V2R to increase AQP2 membrane targeting, but currently no specific pharmacological therapy is available. The present study examined specific E-prostanoid receptors for this purpose. In vitro, prostaglandin E2 (PGE2) and selective agonists for the E-prostanoid receptors EP2 (butaprost) or EP4 (CAY10580) all increased trafficking and ser-264 phosphorylation of AQP2 in Madin-Darby canine kidney cells. Only PGE2 and butaprost increased cAMP and ser-269 phosphorylation of AQP2. Ex vivo, PGE2, butaprost, or CAY10580 increased AQP2 phosphorylation in isolated cortical tubules, whereas PGE2 and butaprost selectively increased AQP2 membrane accumulation in kidney slices. In vivo, a V2R antagonist caused a severe urinary concentrating defect in rats, which was greatly alleviated by treatment with butaprost. In conclusion, EP2 and EP4 agonists increase AQP2 phosphorylation and trafficking, likely through different signaling pathways. Furthermore, EP2 selective agonists can partially compensate for a nonfunctional V2R, providing a rationale for new treatment strategies for hereditary nephrogenic diabetes insipidus.

  4. Prostaglandin E2 Prevents Hyperosmolar-Induced Human Mast Cell Activation through Prostanoid Receptors EP2 and EP4

    PubMed Central

    Torres-Atencio, Ivonne; Ainsua-Enrich, Erola; de Mora, Fernando; Picado, César; Martín, Margarita

    2014-01-01

    Background Mast cells play a critical role in allergic and inflammatory diseases, including exercise-induced bronchoconstriction (EIB) in asthma. The mechanism underlying EIB is probably related to increased airway fluid osmolarity that activates mast cells to the release inflammatory mediators. These mediators then act on bronchial smooth muscle to cause bronchoconstriction. In parallel, protective substances such as prostaglandin E2 (PGE2) are probably also released and could explain the refractory period observed in patients with EIB. Objective This study aimed to evaluate the protective effect of PGE2 on osmotically activated mast cells, as a model of exercise-induced bronchoconstriction. Methods We used LAD2, HMC-1, CD34-positive, and human lung mast cell lines. Cells underwent a mannitol challenge, and the effects of PGE2 and prostanoid receptor (EP) antagonists for EP1–4 were assayed on the activated mast cells. Beta-hexosaminidase release, protein phosphorylation, and calcium mobilization were assessed. Results Mannitol both induced mast cell degranulation and activated phosphatidyl inositide 3-kinase and mitogen-activated protein kinase (MAPK) pathways, thereby causing de novo eicosanoid and cytokine synthesis. The addition of PGE2 significantly reduced mannitol-induced degranulation through EP2 and EP4 receptors, as measured by beta-hexosaminidase release, and consequently calcium influx. Extracellular-signal-regulated kinase 1/2, c-Jun N-terminal kinase, and p38 phosphorylation were diminished when compared with mannitol activation alone. Conclusions Our data show a protective role for the PGE2 receptors EP2 and EP4 following osmotic changes, through the reduction of human mast cell activity caused by calcium influx impairment and MAP kinase inhibition. PMID:25329458

  5. Piracy of PGE2/EP receptor mediated signaling by Kaposi’s sarcoma associated herpes virus (KSHV/HHV-8) for latency gene expression: Strategy of a successful pathogen

    PubMed Central

    Paul, Arun George; Sharma-Walia, Neelam; Kerur, Nagaraj; White, Carl; Chandran, Bala

    2010-01-01

    KSHV is implicated in the pathogenesis of KS, a chronic inflammation associated malignancy. COX-2 and its metabolite PGE2, two pivotal proinflammatory/oncogeneic molecules, are proposed to play roles in the expression of major KSHV latency associated nuclear antigen-1 (LANA-1). Microsomal prostaglandin E2 synthase (mPGES), PGE2 and its receptors (EP1, EP2, EP3, and EP4) were detected in KS lesions with the distinct staining of EP2/EP4 in KS lesions. In latently infected endothelial TIVE-LTC cells, EP receptor antagonists down-regulated LANA-1 expression as well as Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB, which are also some of the signal molecules proposed to be important in KS pathogenesis. Exogenous PGE2 and EP receptor agonists induced the LANA-1 promoter in 293 cells, and YY1, Sp1, Oct-1, Oct-6, C/EBP and c-Jun transcription factors appear to be involved in this induction. PGE2/EP receptor induced LANA-1 promoter activity was down-regulated significantly by the inhibition of Ca2+, p-Src, p-PI3K, p-PKCζ/λ, and p-NF-κB. These findings implicate the inflammatory PGE2/EP receptors and the associated signal molecules in herpes virus latency and uncover a novel paradigm that demonstrates the evolution of KSHV genome plasticity to utilize inflammatory response for its survival advantage of maintaining latent gene expression. This data also suggests that potential use of anti-COX-2 and anti-EP receptor therapy may not only ameliorate the chronic inflammation associated with KS but could also lead to elimination of the KSHV latent infection and the associated KS lesions. PMID:20388794

  6. Reactive astrocyte COX2-PGE2 production inhibits oligodendrocyte maturation in neonatal white matter injury.

    PubMed

    Shiow, Lawrence R; Favrais, Geraldine; Schirmer, Lucas; Schang, Anne-Laure; Cipriani, Sara; Andres, Christian; Wright, Jaclyn N; Nobuta, Hiroko; Fleiss, Bobbi; Gressens, Pierre; Rowitch, David H

    2017-12-01

    Inflammation is a major risk factor for neonatal white matter injury (NWMI), which is associated with later development of cerebral palsy. Although recent studies have demonstrated maturation arrest of oligodendrocyte progenitor cells (OPCs) in NWMI, the identity of inflammatory mediators with direct effects on OPCs has been unclear. Here, we investigated downstream effects of pro-inflammatory IL-1β to induce cyclooxygenase-2 (COX2) and prostaglandin E2 (PGE2) production in white matter. First, we assessed COX2 expression in human fetal brain and term neonatal brain affected by hypoxic-ischemic encephalopathy (HIE). In the developing human brain, COX2 was expressed in radial glia, microglia, and endothelial cells. In human term neonatal HIE cases with subcortical WMI, COX2 was strongly induced in reactive astrocytes with "A2" reactivity. Next, we show that OPCs express the EP1 receptor for PGE2, and PGE2 acts directly on OPCs to block maturation in vitro. Pharmacologic blockade with EP1-specific inhibitors (ONO-8711, SC-51089), or genetic deficiency of EP1 attenuated effects of PGE2. In an IL-1β-induced model of NWMI, astrocytes also exhibit "A2" reactivity and induce COX2. Furthermore, in vivo inhibition of COX2 with Nimesulide rescues hypomyelination and behavioral impairment. These findings suggest that neonatal white matter astrocytes can develop "A2" reactivity that contributes to OPC maturation arrest in NWMI through induction of COX2-PGE2 signaling, a pathway that can be targeted for neonatal neuroprotection. © 2017 Wiley Periodicals, Inc.

  7. Prostaglandin E2-stimulated prostanoid EP4 receptors induce prolonged de novo prostaglandin E2 synthesis through biphasic phosphorylation of extracellular signal-regulated kinases mediated by activation of protein kinase A in HCA-7 human colon cancer cells.

    PubMed

    Fujino, Hiromichi; Seira, Naofumi; Kurata, Naoki; Araki, Yumi; Nakamura, Hiroyuki; Regan, John W; Murayama, Toshihiko

    2015-12-05

    Approximately two decades have passed since E-type prostanoid 4 (EP4) receptors were cloned, and the signaling pathways mediated by these receptors have since been implicated in cancer development through the alliance of Gαi-protein/phosphatidylinositol 3-kinase (PI3K)/extracellular signal-regulated kinases (ERKs) activation. Although prostanoid EP4 receptors were initially identified as Gαs-coupled receptors, the specific/distinctive role(s) of prostanoid EP4 receptor-induced cAMP/protein kinase A (PKA) pathways in cancer development have not yet been elucidated in detail. We previously reported using HCA-7 human colon cancer cells that prostaglandin E2 (PGE2)-stimulated prostanoid EP4 receptors induced cyclooxygenase-2 (COX-2) as an initiating event in development of colon cancer. Moreover, this induction of COX-2 was mediated by transactivation of epidermal growth factor (EGF) receptors. However, direct activation of EGF receptors by EGF also induced similar amounts of COX-2 in this cell line. Thus, the emergence of unique role(s) for prostanoid EP4 receptors is expected by clarifying the different signaling mechanisms between PGE2-stimulated prostanoid EP4 receptors and EGF-stimulated EGF receptors to induce COX-2 and produce PGE2. We here demonstrated that prostanoid EP4 receptor activation by PGE2 in HCA-7 cells led to PKA-dependent re-activation of ERKs, which resulted in prolonged de novo synthesis of PGE2. Although EGF-stimulated EGF receptors in cells also induced COX-2 and the de novo synthesis of PGE2, the activation of this pathway was transient and not mediated by PKA. Therefore, the novel mechanism underlying prolonged de novo synthesis of PGE2 has provided an insight into the importance of prostanoid EP4 receptor-mediated Gαs-protein/cAMP/PKA pathway in development of colon cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Intestinal myofibroblast-specific Tpl2-Cox-2-PGE2 pathway links innate sensing to epithelial homeostasis

    PubMed Central

    Roulis, Manolis; Nikolaou, Christoforos; Kotsaki, Elena; Kaffe, Eleanna; Karagianni, Niki; Koliaraki, Vasiliki; Salpea, Klelia; Ragoussis, Jiannis; Aidinis, Vassilis; Martini, Eva; Becker, Christoph; Herschman, Harvey R.; Vetrano, Stefania; Danese, Silvio; Kollias, George

    2014-01-01

    Tumor progression locus-2 (Tpl2) kinase is a major inflammatory mediator in immune cell types recently found to be genetically associated with inflammatory bowel diseases (IBDs). Here we show that Tpl2 may exert a dominant homeostatic rather than inflammatory function in the intestine mediated specifically by subepithelial intestinal myofibroblasts (IMFs). Mice with complete or IMF-specific Tpl2 ablation are highly susceptible to epithelial injury-induced colitis showing impaired compensatory proliferation in crypts and extensive ulcerations without significant changes in inflammatory responses. Following epithelial injury, IMFs sense innate or inflammatory signals and activate, via Tpl2, the cyclooxygenase-2 (Cox-2)-prostaglandin E2 (PGE2) pathway, which we show here to be essential for the epithelial homeostatic response. Exogenous PGE2 administration rescues mice with complete or IMF-specific Tpl2 ablation from defects in crypt function and susceptibility to colitis. We also show that Tpl2 expression is decreased in IMFs isolated from the inflamed ileum of IBD patients indicating that Tpl2 function in IMFs may be highly relevant to human disease. The IMF-mediated mechanism we propose also involves the IBD-associated genes IL1R1, MAPK1, and the PGE2 receptor-encoding PTGER4. Our results establish a previously unidentified myofibroblast-specific innate pathway that regulates intestinal homeostasis and may underlie IBD susceptibility in humans. PMID:25316791

  9. PGE2-EP2 signalling in endothelium is activated by haemodynamic stress and induces cerebral aneurysm through an amplifying loop via NF-κB

    PubMed Central

    Aoki, T; Nishimura, M; Matsuoka, T; Yamamoto, K; Furuyashiki, T; Kataoka, H; Kitaoka, S; Ishibashi, R; Ishibazawa, A; Miyamoto, S; Morishita, R; Ando, J; Hashimoto, N; Nozaki, K; Narumiya, S

    2011-01-01

    BACKGROUND AND PURPOSE Cerebral aneurysm is a frequent cerebrovascular event and a major cause of fatal subarachnoid haemorrhage, but there is no medical treatment for this condition. Haemodynamic stress and, recently, chronic inflammation have been proposed as major causes of cerebral aneurysm. Nevertheless, links between haemodynamic stress and chronic inflammation remain ill-defined, and to clarify such links, we evaluated the effects of prostaglandin E2 (PGE2), a mediator of inflammation, on the formation of cerebral aneurysms. EXPERIMENTAL APPROACH Expression of COX and prostaglandin E synthase (PGES) and PGE receptors were examined in human and rodent cerebral aneurysm. The incidence, size and inflammation of cerebral aneurysms were evaluated in rats treated with COX-2 inhibitors and mice lacking each prostaglandin receptor. Effects of shear stress and PGE receptor signalling on expression of pro-inflammatory molecules were studied in primary cultures of human endothelial cells (ECs). KEY RESULTS COX-2, microsomal PGES-1 and prostaglandin E receptor 2 (EP2) were induced in ECs in the walls of cerebral aneurysms. Shear stress applied to primary ECs induced COX-2 and EP2. Inhibition or loss of COX-2 or EP2in vivo attenuated each other's expression, suppressed nuclear factor κB (NF-κB)-mediated chronic inflammation and reduced incidence of cerebral aneurysm. EP2 stimulation in primary ECs induced NF-κB activation and expression of the chemokine (C-C motif) ligand 2, essential for cerebral aneurysm. CONCLUSIONS AND IMPLICATIONS These results suggest that shear stress activated PGE2-EP2 pathway in ECs and amplified chronic inflammation via NF-κB. We propose EP2 as a therapeutic target in cerebral aneurysm. PMID:21426319

  10. The prostaglandin E2 receptor PTGER2 and prostaglandin F2α receptor PTGFR mediate oviductal glycoprotein 1 expression in bovine oviductal epithelial cells.

    PubMed

    Zhang, Nan; Mao, Wei; Zhang, Ying; Huang, Na; Liu, Bo; Gao, Long; Zhang, Shuangyi; Cao, Jinshan

    2018-04-13

    Oviductal glycoprotein 1 (OVGP1), an oviductin, is involved in the maintenance of sperm viability and motility and contributes to sperm capacitation in the oviduct. In this study, the regulatory effects exerted by prostaglandin E 2 (PGE 2 ) and F 2α (PGF 2α ) on OVGP1 expression via their corresponding receptors in bovine oviductal epithelial cells (BOECs) were investigated. BOECs were cultured in vitro, and their expression of receptors of PGE 2 (PTGER1, PTGER2, PTGER3, and PTGER4) and PGF 2α (PTGFR) was measured using RT-qPCR. Ca 2+ concentration was determined with a fluorescence-based method and cAMP was quantified by enzyme-linked immunosorbent assays to verify activation of PTGER2 and PTGFR by their corresponding agonists in these cells. OVGP1 mRNA and protein expression was measured using RT-qPCR and western blotting, respectively, following PTGER2 and PTGFR agonist-induced activation. PTGER1, PTGER2, PTGER4, and PTGFR were found to be present in BOECs; however, PTGER3 expression was not detected. OVGP1 expression was significantly promoted by 10 -6 M butaprost (a PTGER2 agonist) and decreased by 10 -6 M fluprostenol (a PTGFR agonist). In addition, 3 μM H-89 (a PKA inhibitor) and 3 μM U0126 (an ERK inhibitor) effectively inhibited PGE 2 -induced upregulation of OVGP1, and 5 μM chelerythrine chloride (a PKC inhibitor) and 3 μM U0126 negated OVGP1 downregulation by PGF 2α . In conclusion, this study demonstrates that OVGP1 expression in BOECs is enhanced by PGE 2 via PTGER2-cAMP-PKA signaling, and reduced by PGF 2α through the PTGFR-Ca 2+ -PKC pathway.

  11. Des-aspartate-angiotensin I causes specific release of PGE2 and PGI2 in HUVEC via the angiotensin AT1 receptor and biased agonism.

    PubMed

    Wen, Qiang; Lee, Kok-Onn; Sim, Sai-Zhen; Xu, Xiao-Guang; Sim, Meng-Kwoon

    2015-12-05

    DAA-I (des-aspartate-angiotensin I), an endogenous angiotensin, had been shown earlier to ameliorate animal models of cardiovascular diseases via the angiotensin AT1 receptor and prostaglandins. The present study investigated further the action of DAA-I on the release of PGE2, PGI2, PGF2α and TXA2 in HUVEC. 10(-11)-10(-8)M DAA-I and 15min incubation specifically released PGE2 and PGI2. The release was inhibited by losartan and indomethacin but not by PD123319 and NS398 indicating that the angiotensin AT1 receptor and COX-1 mediate the release. At concentrations higher than 10(-7)M, DAA-I mimics the action of angiotensin II by releasing TXA2 but had no effect on the production of PGF2α. At similar concentrations and 4h incubation, DAA-I increased the release of the 4 prostaglandins via the angiotensin AT1 receptor and COX-2, again mimicking the action of angiotensin II. HUVEC that were preincubated with DAA-I or angiotensin II, released similar profiles of prostaglandins when incubated with arachidonic acid after the angiotensin had been washed off. We postulate that the internalized DAA-I/receptor complex remains active and mediates the conversion of arachidonic acid to the respective prostaglandins. The release of PGE2 and PGI2 via the angiotensin AT1 receptor and COX-1 is a novel specific action of DAA-I and is likely responsible for its beneficial effects seen in earlier studies. This specific action is definable as a biased agonism of the angiotensin AT1 receptor, which identifies DAA-I as a novel biased agonist and potential therapeutic that is able to produce specific prostaglandins at nanomolar concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells

    PubMed Central

    Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye

    2017-01-01

    Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated. PMID:28472126

  13. Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells.

    PubMed

    Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye; Cheng, Lei

    2017-01-01

    Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated.

  14. Induction of cyclooxygenase-2 expression by prostaglandin E2 stimulation of the prostanoid EP4 receptor via coupling to Gαi and transactivation of the epidermal growth factor receptor in HCA-7 human colon cancer cells.

    PubMed

    Yoshida, Kenji; Fujino, Hiromichi; Otake, Sho; Seira, Naofumi; Regan, John W; Murayama, Toshihiko

    2013-10-15

    Increased expressions of cyclooxygenase-2 (COX-2) and its downstream metabolite, prostaglandin E2 (PGE2), are well documented events in the development of colorectal cancer. Interestingly, PGE2 itself can induce the expression of COX-2 thereby creating the potential for positive feedback. Although evidence for such a positive feedback has been previously described, the specific E-type prostanoid (EP) receptor subtype that mediates this response, as well as the relevant signaling pathways, remain unclear. We now report that the PGE2 stimulated induction of COX-2 expression in human colon cancer HCA-7 cells is mediated by activation of the prostanoid EP4 receptor subtype and is followed by coupling of the receptor to Gαi and the activation of phosphatidylinositol 3-kinase. Subsequent activation of metalloproteinases releases membrane bound heparin-binding epidermal growth factor-like growth factor resulting in the transactivation of epidermal growth factor receptors and the activation of the extracellular signal-regulated kinases and induction of COX-2 expression. This induction of COX-2 expression by PGE2 stimulation of the prostanoid EP4 receptor may underlie the upregulation of COX-2 during colorectal cancer and appears to be an early event in the process of tumorigenesis. © 2013 Elsevier B.V. All rights reserved.

  15. Direct Melanoma Cell Contact Induces Stromal Cell Autocrine Prostaglandin E2-EP4 Receptor Signaling That Drives Tumor Growth, Angiogenesis, and Metastasis*

    PubMed Central

    Inada, Masaki; Takita, Morichika; Yokoyama, Satoshi; Watanabe, Kenta; Tominari, Tsukasa; Matsumoto, Chiho; Hirata, Michiko; Maru, Yoshiro; Maruyama, Takayuki; Sugimoto, Yukihiko; Narumiya, Shuh; Uematsu, Satoshi; Akira, Shizuo; Murphy, Gillian; Nagase, Hideaki; Miyaura, Chisato

    2015-01-01

    The stromal cells associated with tumors such as melanoma are significant determinants of tumor growth and metastasis. Using membrane-bound prostaglandin E synthase 1 (mPges1−/−) mice, we show that prostaglandin E2 (PGE2) production by host tissues is critical for B16 melanoma growth, angiogenesis, and metastasis to both bone and soft tissues. Concomitant studies in vitro showed that PGE2 production by fibroblasts is regulated by direct interaction with B16 cells. Autocrine activity of PGE2 further regulates the production of angiogenic factors by fibroblasts, which are key to the vascularization of both primary and metastatic tumor growth. Similarly, cell-cell interactions between B16 cells and host osteoblasts modulate mPGES-1 activity and PGE2 production by the osteoblasts. PGE2, in turn, acts to stimulate receptor activator of NF-κB ligand expression, leading to osteoclast differentiation and bone erosion. Using eicosanoid receptor antagonists, we show that PGE2 acts on osteoblasts and fibroblasts in the tumor microenvironment through the EP4 receptor. Metastatic tumor growth and vascularization in soft tissues was abrogated by an EP4 receptor antagonist. EP4-null Ptger4−/− mice do not support B16 melanoma growth. In vitro, an EP4 receptor antagonist modulated PGE2 effects on fibroblast production of angiogenic factors. Our data show that B16 melanoma cells directly influence host stromal cells to generate PGE2 signals governing neoangiogenesis and metastatic growth in bone via osteoclast erosive activity as well as angiogenesis in soft tissue tumors. PMID:26475855

  16. Molecular and preclinical basis to inhibit PGE2 receptors EP2 and EP4 as a novel nonsteroidal therapy for endometriosis

    PubMed Central

    Arosh, Joe A.; Lee, JeHoon; Balasubbramanian, Dakshnapriya; Stanley, Jone A.; Long, Charles R.; Meagher, Mary W.; Osteen, Kevin G.; Bruner-Tran, Kaylon L.; Burghardt, Robert C.; Starzinski-Powitz, Anna; Banu, Sakhila K.

    2015-01-01

    Endometriosis is a debilitating, estrogen-dependent, progesterone-resistant, inflammatory gynecological disease of reproductive age women. Two major clinical symptoms of endometriosis are chronic intolerable pelvic pain and subfertility or infertility, which profoundly affect the quality of life in women. Current hormonal therapies to induce a hypoestrogenic state are unsuccessful because of undesirable side effects, reproductive health concerns, and failure to prevent recurrence of disease. There is a fundamental need to identify nonestrogen or nonsteroidal targets for the treatment of endometriosis. Peritoneal fluid concentrations of prostaglandin E2 (PGE2) are higher in women with endometriosis, and this increased PGE2 plays important role in survival and growth of endometriosis lesions. The objective of the present study was to determine the effects of pharmacological inhibition of PGE2 receptors, EP2 and EP4, on molecular and cellular aspects of the pathogenesis of endometriosis and associated clinical symptoms. Using human fluorescent endometriotic cell lines and chimeric mouse model as preclinical testing platform, our results, to our knowledge for the first time, indicate that selective inhibition of EP2/EP4: (i) decreases growth and survival of endometriosis lesions; (ii) decreases angiogenesis and innervation of endometriosis lesions; (iii) suppresses proinflammatory state of dorsal root ganglia neurons to decrease pelvic pain; (iv) decreases proinflammatory, estrogen-dominant, and progesterone-resistant molecular environment of the endometrium and endometriosis lesions; and (v) restores endometrial functional receptivity through multiple mechanisms. Our novel findings provide a molecular and preclinical basis to formulate long-term nonestrogen or nonsteroidal therapy for endometriosis. PMID:26199416

  17. Direct Melanoma Cell Contact Induces Stromal Cell Autocrine Prostaglandin E2-EP4 Receptor Signaling That Drives Tumor Growth, Angiogenesis, and Metastasis.

    PubMed

    Inada, Masaki; Takita, Morichika; Yokoyama, Satoshi; Watanabe, Kenta; Tominari, Tsukasa; Matsumoto, Chiho; Hirata, Michiko; Maru, Yoshiro; Maruyama, Takayuki; Sugimoto, Yukihiko; Narumiya, Shuh; Uematsu, Satoshi; Akira, Shizuo; Murphy, Gillian; Nagase, Hideaki; Miyaura, Chisato

    2015-12-11

    The stromal cells associated with tumors such as melanoma are significant determinants of tumor growth and metastasis. Using membrane-bound prostaglandin E synthase 1 (mPges1(-/-)) mice, we show that prostaglandin E2 (PGE2) production by host tissues is critical for B16 melanoma growth, angiogenesis, and metastasis to both bone and soft tissues. Concomitant studies in vitro showed that PGE2 production by fibroblasts is regulated by direct interaction with B16 cells. Autocrine activity of PGE2 further regulates the production of angiogenic factors by fibroblasts, which are key to the vascularization of both primary and metastatic tumor growth. Similarly, cell-cell interactions between B16 cells and host osteoblasts modulate mPGES-1 activity and PGE2 production by the osteoblasts. PGE2, in turn, acts to stimulate receptor activator of NF-κB ligand expression, leading to osteoclast differentiation and bone erosion. Using eicosanoid receptor antagonists, we show that PGE2 acts on osteoblasts and fibroblasts in the tumor microenvironment through the EP4 receptor. Metastatic tumor growth and vascularization in soft tissues was abrogated by an EP4 receptor antagonist. EP4-null Ptger4(-/-) mice do not support B16 melanoma growth. In vitro, an EP4 receptor antagonist modulated PGE2 effects on fibroblast production of angiogenic factors. Our data show that B16 melanoma cells directly influence host stromal cells to generate PGE2 signals governing neoangiogenesis and metastatic growth in bone via osteoclast erosive activity as well as angiogenesis in soft tissue tumors. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. PGE2 maintains self-renewal of human adult stem cells via EP2-mediated autocrine signaling and its production is regulated by cell-to-cell contact.

    PubMed

    Lee, Byung-Chul; Kim, Hyung-Sik; Shin, Tae-Hoon; Kang, Insung; Lee, Jin Young; Kim, Jae-Jun; Kang, Hyun Kyoung; Seo, Yoojin; Lee, Seunghee; Yu, Kyung-Rok; Choi, Soon Won; Kang, Kyung-Sun

    2016-05-27

    Mesenchymal stem cells (MSCs) possess unique immunomodulatory abilities. Many studies have elucidated the clinical efficacy and underlying mechanisms of MSCs in immune disorders. Although immunoregulatory factors, such as Prostaglandin E2 (PGE2), and their mechanisms of action on immune cells have been revealed, their effects on MSCs and regulation of their production by the culture environment are less clear. Therefore, we investigated the autocrine effect of PGE2 on human adult stem cells from cord blood or adipose tissue, and the regulation of its production by cell-to-cell contact, followed by the determination of its immunomodulatory properties. MSCs were treated with specific inhibitors to suppress PGE2 secretion, and proliferation was assessed. PGE2 exerted an autocrine regulatory function in MSCs by triggering E-Prostanoid (EP) 2 receptor. Inhibiting PGE2 production led to growth arrest, whereas addition of MSC-derived PGE2 restored proliferation. The level of PGE2 production from an equivalent number of MSCs was down-regulated via gap junctional intercellular communication. This cell contact-mediated decrease in PGE2 secretion down-regulated the suppressive effect of MSCs on immune cells. In conclusion, PGE2 produced by MSCs contributes to maintenance of self-renewal capacity through EP2 in an autocrine manner, and PGE2 secretion is down-regulated by cell-to-cell contact, attenuating its immunomodulatory potency.

  19. PGE2 through the EP4 receptor controls smooth muscle gene expression patterns in the ductus arteriosus critical for remodeling at birth

    PubMed Central

    Gruzdev, Artiom; Nguyen, MyTrang; Kovarova, Martina; Koller, Beverly H.

    2012-01-01

    The ductus arteriosus (DA) is a fetal shunt that directs right ventricular outflow away from pulmonary circulation and into the aorta. Critical roles for prostaglandin E2 (PGE2) and the EP4 receptor (EP4) have been established in maintaining both the patency of the vessel in utero and in its closure at birth. Here we have generated mice in which loss of EP4 expression is limited to either the smooth muscle (SMC) or endothelial cells and demonstrated that SMC, but not endothelial cell expression of EP4 is required for DA closure. The genome wide expression analysis of full term wild type and EP4−/− DA indicates that PGE2/EP4 signaling modulates expression of a number of unique pathways, including those involved in SMC proliferation, cell migration, and vascular tone. Together this supports a mechanism by which maturation and increased contractility of the vessel is coupled to the potent smooth muscle dilatory actions of PGE2. PMID:22342504

  20. Gut Microbiota Promotes Obesity-Associated Liver Cancer through PGE2-Mediated Suppression of Antitumor Immunity.

    PubMed

    Loo, Tze Mun; Kamachi, Fumitaka; Watanabe, Yoshihiro; Yoshimoto, Shin; Kanda, Hiroaki; Arai, Yuriko; Nakajima-Takagi, Yaeko; Iwama, Atsushi; Koga, Tomoaki; Sugimoto, Yukihiko; Ozawa, Takayuki; Nakamura, Masaru; Kumagai, Miho; Watashi, Koichi; Taketo, Makoto M; Aoki, Tomohiro; Narumiya, Shuh; Oshima, Masanobu; Arita, Makoto; Hara, Eiji; Ohtani, Naoko

    2017-05-01

    Obesity increases the risk of cancers, including hepatocellular carcinomas (HCC). However, the precise molecular mechanisms through which obesity promotes HCC development are still unclear. Recent studies have shown that gut microbiota may influence liver diseases by transferring its metabolites and components. Here, we show that the hepatic translocation of obesity-induced lipoteichoic acid (LTA), a Gram-positive gut microbial component, promotes HCC development by creating a tumor-promoting microenvironment. LTA enhances the senescence-associated secretory phenotype (SASP) of hepatic stellate cells (HSC) collaboratively with an obesity-induced gut microbial metabolite, deoxycholic acid, to upregulate the expression of SASP factors and COX2 through Toll-like receptor 2. Interestingly, COX2-mediated prostaglandin E 2 (PGE 2 ) production suppresses the antitumor immunity through a PTGER4 receptor, thereby contributing to HCC progression. Moreover, COX2 overexpression and excess PGE 2 production were detected in HSCs in human HCCs with noncirrhotic, nonalcoholic steatohepatitis (NASH), indicating that a similar mechanism could function in humans. Significance: We showed the importance of the gut-liver axis in obesity-associated HCC. The gut microbiota-driven COX2 pathway produced the lipid mediator PGE 2 in senescent HSCs in the tumor microenvironment, which plays a pivotal role in suppressing antitumor immunity, suggesting that PGE 2 and its receptor may be novel therapeutic targets for noncirrhotic NASH-associated HCC. Cancer Discov; 7(5); 522-38. ©2017 AACR. This article is highlighted in the In This Issue feature, p. 443 . ©2017 American Association for Cancer Research.

  1. Pathophysiological role of prostaglandin E2-induced up-regulation of the EP2 receptor in motor neuron-like NSC-34 cells and lumbar motor neurons in ALS model mice.

    PubMed

    Kosuge, Yasuhiro; Miyagishi, Hiroko; Yoneoka, Yuki; Yoneda, Keiko; Nango, Hiroshi; Ishige, Kumiko; Ito, Yoshihisa

    2017-07-04

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by selective degeneration of motor neurons. The primary triggers for motor neuronal death are still unknown, but inflammation is considered to be an important factor contributing to the pathophysiology of ALS both clinically and in ALS models. Prostaglandin E2 (PGE2) and its corresponding four E-prostanoid receptors play a pivotal role in the degeneration of motor neurons in human and transgenic models of ALS. It has also been shown that PGE2-EP2 signaling in glial cells (astrocytes or microglia) promotes motor neuronal death in G93A mice. The present study was designed to investigate the levels of expression of EP receptors in the spinal motor neurons of ALS model mice and to examine whether PGE2 alters the expression of EP receptors in differentiated NSC-34 cells, a motor neuron-like cell line. Immunohistochemical staining demonstrated that EP2 and EP3 immunoreactivity was localized in NeuN-positive large cells showing the typical morphology of motor neurons in mice. Semi-quantitative analysis showed that the immunoreactivity of EP2 in motor neurons was significantly increased in the early symptomatic stage in ALS model mice. In contrast, the level of EP3 expression remained constant, irrespective of age. In differentiated NSC-34 cells, bath application of PGE2 resulted in a concentration-dependent decrease of MTT reduction. Although PGE2 had no effect on cell survival at concentrations of less than 10 μM, pretreatment with 10 μM PGE2 significantly up-regulated EP2 and concomitantly potentiated cell death induced by 30 μM PGE2. These results suggest that PGE2 is an important effector for induction of the EP2 subtype in differentiated NSC-34 cells, and that not only EP2 up-regulation in glial cells but also EP2 up-regulation in motor neurons plays a pivotal role in the vulnerability of motor neurons in ALS model mice. Copyright © 2017 Elsevier Ltd. All rights

  2. Prostaglandin E2 produced by Entamoeba histolytica binds to EP4 receptors and stimulates interleukin-8 production in human colonic cells.

    PubMed

    Dey, Indranil; Chadee, Kris

    2008-11-01

    Entamoeba histolytica pathogenesis in the colon occurs in a stepwise fashion. It begins with colonization of the mucin layer, which is followed by stimulation of a proinflammatory response that causes nonspecific tissue damage that may facilitate parasite invasion of the underlying colonic mucosa. Unfortunately, the parasite and/or host factors that stimulate a proinflammatory response in the gut are poorly understood. In this study, we found that live E. histolytica or secretory or proteins (SP) and soluble ameba components (SAP) can markedly increase interleukin-8 (IL-8) mRNA expression and protein production in colonic epithelial cells. The IL-8-stimulating molecule produced by live amebae was identified as prostaglandin E(2) (PGE(2)) as trophozoites treated with cyclooxygenase inhibitors inhibited the biosynthesis of PGE(2) and eliminated IL-8 production induced by live parasites or ameba components. Moreover, using specific prostaglandin EP2 and EP4 receptor agonists and antagonists, we found that PGE(2) binds exclusively through EP4 receptors in colonic epithelial cells to stimulate IL-8 production. Silencing of EP4 receptors with EP4 small interfering RNA completely eliminated SP- and SAP-induced IL-8 production. These studies identified bioactive PGE(2) as a one of the major virulence factors produced by E. histolytica that can stimulate the potent neutrophil chemokine and activator IL-8, which can trigger an acute host inflammatory response. Thus, the induction of IL-8 production in response to E. histolytica-derived PGE(2) may be a mechanism that explains the initiation and amplification of acute inflammation associated with intestinal amebiasis.

  3. Interleukin-6 and soluble interleukin-6 receptor suppress osteoclastic differentiation by inducing PGE(2) production in chondrocytes.

    PubMed

    Honda, Kazuhiro

    2011-03-01

    This study examined how interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6r) influence osteoclastic differentiation through the function of chondrocytes. Chondrocytes were cultured with or without IL-6 and/or sIL-6r in the presence or absence of NS398, a specific inhibitor of cyclooxygenase (COX)-2, for up to 28 days. Chondrocytes were also cultured with or without IL-6 and sIL-6r for 28 days, and the conditioned medium from cells cultured without IL-6 and sIL-6r was used to induce differentiation of RAW264.7 cells into osteoclast precursors. Osteoclastic differentiation was assessed by tartrate-resistant acid phosphatase (TRAP) staining. Expression of osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), COX-2, and prostaglandin E(2) (PGE(2)) increased in cells exposed to IL-6 and sIL-6r, whereas expression of macrophage colony-stimulating factor (M-CSF) and bone resorption-related enzymes decreased. NS398 blocked the stimulatory/suppressive effects of IL-6 and sIL-6r on the expression of OPG, RANKL, and M-CSF. Fewer TRAP-positive multinucleated cells were detected after treatment with conditioned medium from IL-6- and sIL-6r-treated chondrocytes than after treatment with conditioned medium from untreated chondrocytes. These results suggest that IL-6 and sIL-6r interfere with osteoclast function through the involvement of chondrocytes. Specifically, they appear to suppress the differentiation of osteoclast precursors into osteoclasts by inducing chondrocytic PGE(2) production, which, in turn, increases OPG secretion and decreases M-CSF secretion by chondrocytes.

  4. CO2-evoked release of PGE2 modulates sighs and inspiration as demonstrated in brainstem organotypic culture

    PubMed Central

    Forsberg, David; Horn, Zachi; Tserga, Evangelia; Smedler, Erik; Silberberg, Gilad; Shvarev, Yuri; Kaila, Kai; Uhlén, Per; Herlenius, Eric

    2016-01-01

    Inflammation-induced release of prostaglandin E2 (PGE2) changes breathing patterns and the response to CO2 levels. This may have fatal consequences in newborn babies and result in sudden infant death. To elucidate the underlying mechanisms, we present a novel breathing brainstem organotypic culture that generates rhythmic neural network and motor activity for 3 weeks. We show that increased CO2 elicits a gap junction-dependent release of PGE2. This alters neural network activity in the preBötzinger rhythm-generating complex and in the chemosensitive brainstem respiratory regions, thereby increasing sigh frequency and the depth of inspiration. We used mice lacking eicosanoid prostanoid 3 receptors (EP3R), breathing brainstem organotypic slices and optogenetic inhibition of EP3R+/+ cells to demonstrate that the EP3R is important for the ventilatory response to hypercapnia. Our study identifies a novel pathway linking the inflammatory and respiratory systems, with implications for inspiration and sighs throughout life, and the ability to autoresuscitate when breathing fails. DOI: http://dx.doi.org/10.7554/eLife.14170.001 PMID:27377173

  5. Airway remodeling in murine asthma correlates with a defect in PGE2 synthesis by lung fibroblasts

    PubMed Central

    Stumm, Camila Leindecker; Wettlaufer, Scott H.; Jancar, Sonia

    2011-01-01

    Asthma is a chronic lung disease characterized by local inflammation that can result in structural alterations termed airway remodeling. One component of airway remodeling involves fibroblast accumulation and activation, resulting in deposition of collagen I around small bronchi. Prostaglandin E2 (PGE2) is the main eicosanoid lipid mediator produced by lung fibroblasts, and it exerts diverse anti-fibrotic actions. Dysregulation of the PGE2 synthesis/response axis has been identified in human pulmonary fibrotic diseases and implicated in the pathogenesis of animal models of lung parenchymal fibrosis. Here we investigated the relationship between the fibroblast PGE2 axis and airway fibrosis in an animal model of chronic allergic asthma. Airway fibrosis increased progressively as the number of airway challenges with antigen increased from 3 to 7 to 12. Compared with cells from control lungs, fibroblasts grown from the lungs of asthmatic animals, regardless of challenge number, exhibited no defect in the ability of PGE2 or its analogs to inhibit cellular proliferation and collagen I expression. This correlated with intact expression of the EP2 receptor, which is pivotal for PGE2 responsiveness. However, cytokine-induced upregulation of PGE2 biosynthesis as well as expression of cyclooxygenase-2 (COX-2) and microsomal PGE synthase-1 declined with increasing numbers of antigen challenges. In addition, treatment with the COX-2-selective inhibitor nimesulide potentiated the degree of airway fibrosis following repeated allergen challenge. Because endogenous COX-2-derived PGE2 acts as a brake on airway fibrosis, the inability of fibroblasts to upregulate PGE2 generation in the inflammatory milieu presented by repeated allergen exposure could contribute to the airway remodeling and fibrosis observed in chronic asthma. PMID:21873451

  6. Silymarin suppresses the PGE2 -induced cell migration through inhibition of EP2 activation; G protein-dependent PKA-CREB and G protein-independent Src-STAT3 signal pathways.

    PubMed

    Woo, Seon Min; Min, Kyoung-Jin; Chae, In Gyeong; Chun, Kyung-Soo; Kwon, Taeg Kyu

    2015-03-01

    Silymarin has been known as a chemopreventive agent, and possesses multiple anti-cancer activities including induction of apoptosis, inhibition of proliferation and growth, and blockade of migration and invasion. However, whether silymarin could inhibit prostaglandin (PG) E2 -induced renal cell carcinoma (RCC) migration and what are the underlying mechanisms are not well elucidated. Here, we found that silymarin markedly inhibited PGE2 -stimulated migration. PGE2 induced G protein-dependent CREB phosphorylation via protein kinase A (PKA) signaling, and PKA inhibitor (H89) inhibited PGE2 -mediated migration. Silymarin reduced PGE2 -induced CREB phosphorylation and CRE-promoter activity. PGE2 also activated G protien-independent signaling pathways (Src and STAT3) and silymarin reduced PGE2 -induced phosphorylation of Src and STAT3. Inhibitor of Src (Saracatinib) markedly reduced PGE2 -mediated migration. We found that EP2, a PGE2 receptor, is involved in PGE2 -mediated cell migration. Down regulation of EP2 by EP2 siRNA and EP2 antagonist (AH6809) reduced PGE2 -inudced migration. In contrast, EP2 agonist (Butaprost) increased cell migration and silymarin effectively reduced butaprost-mediated cell migration. Moreover, PGE2 increased EP2 expression through activation of positive feedback mechanism, and PGE2 -induced EP2 expression, as well as basal EP2 levels, were reduced in silymarin-treated cells. Taken together, our study demonstrates that silymarin inhibited PGE2 -induced cell migration through inhibition of EP2 signaling pathways (G protein dependent PKA-CREB and G protein-independent Src-STAT3). © 2013 Wiley Periodicals, Inc.

  7. Inflammation in gastric cancer: Interplay of the COX-2/prostaglandin E2 and Toll-like receptor/MyD88 pathways.

    PubMed

    Echizen, Kanae; Hirose, Osamu; Maeda, Yusuke; Oshima, Masanobu

    2016-04-01

    Cyclooxygenase-2 (COX-2) and its downstream product prostaglandin E2 (PGE2 ) play a key role in generation of the inflammatory microenvironment in tumor tissues. Gastric cancer is closely associated with Helicobacter pylori infection, which stimulates innate immune responses through Toll-like receptors (TLRs), inducing COX-2/PGE2 pathway through nuclear factor-κB activation. A pathway analysis of human gastric cancer shows that both the COX-2 pathway and Wnt/β-catenin signaling are significantly activated in tubular-type gastric cancer, and basal levels of these pathways are also increased in other types of gastric cancer. Expression of interleukin-11, chemokine (C-X-C motif) ligand 1 (CXCL1), CXCL2, and CXCL5, which play tumor-promoting roles through a variety of mechanisms, is induced in a COX-2/PGE2 pathway-dependent manner in both human and mouse gastric tumors. Moreover, the COX-2/PGE2 pathway plays an important role in the maintenance of stemness with expression of stem cell markers, including CD44, Prom1, and Sox9, which are induced in both gastritis and gastric tumors through a COX-2/PGE2 -dependent mechanism. In contrast, disruption of Myd88 results in suppression of the inflammatory microenvironment in gastric tumors even when the COX-2/PGE2 pathway is activated, indicating that the interplay of the COX-2/PGE2 and TLR/MyD88 pathways is needed for inflammatory response in tumor tissues. Furthermore, TLR2/MyD88 signaling plays a role in maintenance of stemness in normal stem cells as well as gastric tumor cells. Accordingly, these results suggest that targeting the COX-2/PGE2 pathway together with TLR/MyD88 signaling, which would suppress the inflammatory microenvironment and maintenance of stemness, could be an effective preventive or therapeutic strategy for gastric cancer. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  8. Evidence of substance P autocrine circuitry that involves TNF-α, IL-6, and PGE2 in endogenous pyrogen-induced fever.

    PubMed

    Brito, Haissa Oliveira; Barbosa, Felipe L; Reis, Renata Cristiane Dos; Fraga, Daniel; Borges, Beatriz S; Franco, Celia R C; Zampronio, Aleksander Roberto

    2016-04-15

    Substance P (SP) is involved in fever that is induced by lipopolysaccharide (LPS) but not by interleukin-1β or macrophage inflammatory protein-1α. Intracerebroventricular (i.c.v.) administration of the neurokinin-1 (NK1) receptor antagonist SR140333B in rats reduced fever that was induced by an i.c.v. injection of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), corticotropin-releasing factor (CRF), endothelin-1 (ET-1), and morphine (MOR). Furthermore, an i.c.v. injection of SP induced a febrile response that was inhibited by indomethacin concomitant with an increase in PGE2 levels in cerebrospinal fluid. Lipopolysaccharide and PGE2 caused higher expression and internalization of NK1 receptors in the hypothalamus which were prevented by SR140333B. These data suggest that SP is an important mediator of fever, in which it induces a prostaglandin-dependent response and is released after TNF-α, IL-6, PGE2, CRF, endogenous opioids, and ET-1. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. ERK1/2/COX-2/PGE2 signaling pathway mediates GPR91-dependent VEGF release in streptozotocin-induced diabetes

    PubMed Central

    Li, Tingting; Hu, Jianyan; Du, Shanshan; Chen, Yongdong; Wang, Shuai

    2014-01-01

    Purpose Retinal vascular dysfunction caused by vascular endothelial growth factor (VEGF) is the major pathological change that occurs in diabetic retinopathy (DR). It has recently been demonstrated that G protein-coupled receptor 91 (GPR91) plays a major role in both vasculature development and retinal angiogenesis. In this study, we examined the signaling pathways involved in GPR91-dependent VEGF release during the early stages of retinal vascular change in streptozotocin-induced diabetes. Methods Diabetic rats were assigned randomly to receive intravitreal injections of shRNA lentiviral particles targeting GPR91 (LV.shGPR91) or control particles (LV.shScrambled). Accumulation of succinate was assessed by gas chromatography-mass spectrometry (GC-MS). At 14 weeks, the ultrastructure and function of the retinal vessels of diabetic retinas with or without shRNA treatment were assessed using hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), and Evans blue dye permeability. The expression of GPR91, extracellular signal-regulated kinases 1 and 2 (ERK1/2) and cyclooxygenase-2 (COX-2) were measured using immunofluorescence and western blotting. COX-2 and VEGF mRNA were determined by quantitative RT–PCR. Prostaglandin E2 (PGE2) and VEGF secretion were detected using an enzyme-linked immunosorbent assay. Results Succinate exhibited abundant accumulation in diabetic rat retinas. The retinal telangiectatic vessels, basement membrane thickness, and Evans blue dye permeability were attenuated by treatment with GPR91 shRNA. In diabetic rats, knockdown of GPR91 inhibited the activities of ERK1/2 and COX-2 as well as the expression of PGE2 and VEGF. Meanwhile, COX-2, PGE2, and VEGF expression was inhibited by ERK1/2 inhibitor U0126 and COX-2 inhibitor NS-398. Conclusions Our data suggest that hyperglycemia causes succinate accumulation and GPR91 activity in retinal ganglion cells, which mediate VEGF-induced retinal vascular change via the ERK1/2/COX-2

  10. Renoprotective effect of berberine via regulating the PGE2 -EP1-Gαq-Ca(2+) signalling pathway in glomerular mesangial cells of diabetic rats.

    PubMed

    Ni, Wei-Jian; Tang, Li-Qin; Zhou, Hong; Ding, Hai-Hua; Qiu, Yuan-Ye

    2016-08-01

    G-protein coupled receptor-mediated pathogenesis is of great importance in the development of diabetic complications, but the detailed mechanisms have not yet been clarified. Therefore, we aimed to explore the roles of the prostaglandin E2 receptor 1 (EP1)-mediated signalling pathway and develop a corresponding treatment for diabetic nephropathy (DN). To create the DN model, rats fed a high-fat and high-glucose diet were injected with a single dose of streptozotocin (35 mg/kg, i.p.). Then, rats were either treated or not with berberine (100 mg/kg per day, i.g., 8 weeks). Cells were isolated from the renal cortex and cultured in high-sugar medium with 20% foetal bovine serum. Prostaglandin E2 (PGE2 ) levels were determined by ELISA, and cells were identified by fluorescence immunoassay. We measured the biochemical characteristics and observed morphological changes by periodic-acid-Schiff staining. The expression of the EP1 receptor and the roles of GRK2 and β-arrestin2 were identified using western blotting and flow cytometry. Downstream proteins were detected by western blot, while molecular changes were assessed by ELISA and laser confocal scanning microscopy. Berberine not only improved the majority of biochemical and renal functional parameters but also improved the histopathological alterations. A significant increase in PGE2 level, EP1 membrane expression and Gαq expression, and concentration of Ca(2+) were observed, accompanied by increased GRK2 and β-arrestin2 levels soon afterwards. Berberine decreased the abnormal concentration of Ca(2+) , the increased levels of PGE2 , the high expression of EP1 and Gαq and suppressed the proliferation of mesangial cells. The EP1 receptor, a critical therapeutic target of the signalling pathway, contributed to mesangial cell abnormalities, which are linked to renal injury in DN. The observed renoprotective effects of berberine via regulating the PGE2 -EP1-Gαq-Ca(2+) signalling pathway indicating that berberine

  11. Suppression of inflammation with conditional deletion of the prostaglandin E2 EP2 receptor in macrophages and brain microglia.

    PubMed

    Johansson, Jenny U; Pradhan, Suraj; Lokteva, Ludmila A; Woodling, Nathaniel S; Ko, Novie; Brown, Holden D; Wang, Qian; Loh, Christina; Cekanaviciute, Egle; Buckwalter, Marion; Manning-Bog, Amy B; Andreasson, Katrin I

    2013-10-02

    Prostaglandin E2 (PGE2), a potent lipid signaling molecule, modulates inflammatory responses through activation of downstream G-protein coupled EP(1-4) receptors. Here, we investigated the cell-specific in vivo function of PGE2 signaling through its E-prostanoid 2 (EP2) receptor in murine innate immune responses systemically and in the CNS. In vivo, systemic administration of lipopolysaccharide (LPS) resulted in a broad induction of cytokines and chemokines in plasma that was significantly attenuated in EP2-deficient mice. Ex vivo stimulation of peritoneal macrophages with LPS elicited proinflammatory responses that were dependent on EP2 signaling and that overlapped with in vivo plasma findings, suggesting that myeloid-lineage EP2 signaling is a major effector of innate immune responses. Conditional deletion of the EP2 receptor in myeloid lineage cells in Cd11bCre;EP2(lox/lox) mice attenuated plasma inflammatory responses and transmission of systemic inflammation to the brain was inhibited, with decreased hippocampal inflammatory gene expression and cerebral cortical levels of IL-6. Conditional deletion of EP2 significantly blunted microglial and astrocytic inflammatory responses to the neurotoxin MPTP and reduced striatal dopamine turnover. Suppression of microglial EP2 signaling also increased numbers of dopaminergic (DA) neurons in the substantia nigra independent of MPTP treatment, suggesting that microglial EP2 may influence development or survival of DA neurons. Unbiased microarray analysis of microglia isolated from adult Cd11bCre;EP2(lox/lox) and control mice demonstrated a broad downregulation of inflammatory pathways with ablation of microglial EP2 receptor. Together, these data identify a cell-specific proinflammatory role for macrophage/microglial EP2 signaling in innate immune responses systemically and in brain.

  12. Suppression of Inflammation with Conditional Deletion of the Prostaglandin E2 EP2 Receptor in Macrophages and Brain Microglia

    PubMed Central

    Johansson, Jenny U.; Pradhan, Suraj; Lokteva, Ludmila A.; Woodling, Nathaniel S.; Ko, Novie; Brown, Holden D.; Wang, Qian; Loh, Christina; Cekanaviciute, Egle; Buckwalter, Marion; Manning-Boğ, Amy B.

    2013-01-01

    Prostaglandin E2 (PGE2), a potent lipid signaling molecule, modulates inflammatory responses through activation of downstream G-protein coupled EP1–4 receptors. Here, we investigated the cell-specific in vivo function of PGE2 signaling through its E-prostanoid 2 (EP2) receptor in murine innate immune responses systemically and in the CNS. In vivo, systemic administration of lipopolysaccharide (LPS) resulted in a broad induction of cytokines and chemokines in plasma that was significantly attenuated in EP2-deficient mice. Ex vivo stimulation of peritoneal macrophages with LPS elicited proinflammatory responses that were dependent on EP2 signaling and that overlapped with in vivo plasma findings, suggesting that myeloid-lineage EP2 signaling is a major effector of innate immune responses. Conditional deletion of the EP2 receptor in myeloid lineage cells in Cd11bCre;EP2lox/lox mice attenuated plasma inflammatory responses and transmission of systemic inflammation to the brain was inhibited, with decreased hippocampal inflammatory gene expression and cerebral cortical levels of IL-6. Conditional deletion of EP2 significantly blunted microglial and astrocytic inflammatory responses to the neurotoxin MPTP and reduced striatal dopamine turnover. Suppression of microglial EP2 signaling also increased numbers of dopaminergic (DA) neurons in the substantia nigra independent of MPTP treatment, suggesting that microglial EP2 may influence development or survival of DA neurons. Unbiased microarray analysis of microglia isolated from adult Cd11bCre;EP2lox/lox and control mice demonstrated a broad downregulation of inflammatory pathways with ablation of microglial EP2 receptor. Together, these data identify a cell-specific proinflammatory role for macrophage/microglial EP2 signaling in innate immune responses systemically and in brain. PMID:24089506

  13. Prostaglandin transporter (OATP2A1/SLCO2A1) contributes to local disposition of eicosapentaenoic acid-derived PGE3.

    PubMed

    Gose, Tomoka; Nakanishi, Takeo; Kamo, Shunsuke; Shimada, Hiroaki; Otake, Katsumasa; Tamai, Ikumi

    2016-01-01

    Eicosapentaenoic acid (EPA)-derived prostaglandin E3 (PGE3) possesses an anti-inflammatory effect; however, information for transporters that regulate its peri-cellular concentration is limited. The present study, therefore, aimed to clarify transporters involved in local disposition of PGE3. PGE3 uptake was assessed in HEK293 cells transfected with OATP2A1/SLCO2A1, OATP1B1/SLCO1B1, OATP2B1/SLCO2B1, OAT1/SLC22A6, OCT1/SLC22A1 or OCT2/SLC22A2 genes, compared with HEK293 cells transfected with plasmid vector alone (Mock). PGE3 uptake by OATP2A1-expressing HEK293 cells (HEK/2A1) was the highest and followed by HEK/1B1, while no significantly higher uptake of PGE3 than Mock cells was detected by other transporters. Saturation kinetics in PGE3 uptake by HEK/2A1 estimated the Km as 7.202 ± 0.595 μM, which was 22 times higher than that of PGE2 (Km=0.331 ± 0.131 μM). Furthermore, tissue disposition of PGE3 was examined in wild-type (WT) and Slco2a1-deficient (Slco2a1(-/-)) mice after oral administration of EPA ethyl ester (EPA-E) when they underwent intraperitoneal injection of endotoxin (e.g., lipopolysaccharide). PGE3 concentration was significantly higher in the lung, and tended to increase in the colon, stomach, and kidney of Slco2a1(-/-), compared to WT mice. Ratio of PGE2 metabolite 15-keto PGE2 over PGE2 concentration was significantly lower in the lung and colon of Slco2a1(-/-) than that of WT mice, suggesting that PGE3 metabolism is downregulated in Slco2a1(-/-) mice. In conclusion, PGE3 was found to be a substrate of OATP2A1, and local disposition of PGE3 could be regulated by OATP2A1 at least in the lung. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Prostaglandin E2 Inhibits Histamine-Evoked Ca2+ Release in Human Aortic Smooth Muscle Cells through Hyperactive cAMP Signaling Junctions and Protein Kinase A

    PubMed Central

    Taylor, Emily J. A.; Pantazaka, Evangelia; Shelley, Kathryn L.

    2017-01-01

    In human aortic smooth muscle cells, prostaglandin E2 (PGE2) stimulates adenylyl cyclase (AC) and attenuates the increase in intracellular free Ca2+ concentration evoked by activation of histamine H1 receptors. The mechanisms are not resolved. We show that cAMP mediates inhibition of histamine-evoked Ca2+ signals by PGE2. Exchange proteins activated by cAMP were not required, but the effects were attenuated by inhibition of cAMP-dependent protein kinase (PKA). PGE2 had no effect on the Ca2+ signals evoked by protease-activated receptors, heterologously expressed muscarinic M3 receptors, or by direct activation of inositol 1,4,5-trisphosphate (IP3) receptors by photolysis of caged IP3. The rate of Ca2+ removal from the cytosol was unaffected by PGE2, but PGE2 attenuated histamine-evoked IP3 accumulation. Substantial inhibition of AC had no effect on the concentration-dependent inhibition of Ca2+ signals by PGE2 or butaprost (to activate EP2 receptors selectively), but it modestly attenuated responses to EP4 receptors, activation of which generated less cAMP than EP2 receptors. We conclude that inhibition of histamine-evoked Ca2+ signals by PGE2 occurs through “hyperactive signaling junctions,” wherein cAMP is locally delivered to PKA at supersaturating concentrations to cause uncoupling of H1 receptors from phospholipase C. This sequence allows digital signaling from PGE2 receptors, through cAMP and PKA, to histamine-evoked Ca2+ signals. PMID:28877931

  15. Kinetics of prostaglandin E2 and thromboxane A2 synthesis and suppression of PHA-stimulated peripheral blood mononuclear leucocytes.

    PubMed Central

    Awara, W; Hillier, K; Jones, D

    1986-01-01

    The immunomodulatory effects of thromboxane A2 and prostaglandin E2 on peripheral blood mononuclear leucocytes stimulated with PHA in vitro, and the relationship of this to the time-course of their synthesis in culture, were investigated using prostaglandin E2, a thromboxane A2 synthesis inhibitor (UK37248), a thromboxane A2 mimic (U46619) and a thromboxane A2 receptor blocker (EP045). The inhibitory effect of prostaglandin E2 on PHA-induced human peripheral blood mononuclear leucocyte proliferation diminishes if the addition of PGE2 is delayed. If added 4 hr after a maximum concentration of PHA (5 micrograms/ml), the effect of PGE2 was reduced by 60%. If a submaximal concentration of PHA (1 microgram/ml) was used, the effect of PGE2 was not reduced if added 4 hr later but fell by about 60% after 16 hr. UK37248 moderately inhibited PHA-induced activation while substantially inhibiting thromboxane A2 synthesis and simultaneously enhancing PGE2 synthesis. The enhanced accumulation of PGE2 occurs while sensitivity to PGE2 is dropping. U46619, exogenously applied as a thromboxane A2 mimic, inhibited PHA-induced activation at concentrations that did not significantly alter PGE2 synthesis. EP045, which may modulate the effects of endogenous thromboxane A2 by blocking receptors, did not alter PHA-induced activation. We conclude that thromboxane A2 may have a role in inhibiting PHA-induced activation on the basis of the effect of U46619. However, this study highlights difficulties in utilizing prostaglandin and thromboxane receptor and synthesis inhibitors to examine their endogenous role in the modulation of mitogen-induced activation in vitro. If sensitivity to the purported endogenous substance is limited to the early stages of culture and if only low levels are synthesized at this early stage, then blocking drugs would have little effect. PMID:3468061

  16. Effect of PGE2 on the cell surface molecule expression in PMA treated thymocytes.

    PubMed

    Daculsi, R; Vaillier, D; Carron, J C; Gualde, N

    1998-02-01

    PGE2 is produced by cells of the thymic microenvironment. The effects of PGE2 are mediated by cAMP through binding to its intracellular receptor protein kinase A (PKA). Phorbol 12-myristate 13-acetate (PMA) is known to modulate CD molecule expression on thymocytes, probably through activation of protein kinase C (PKC). We have hypothesized that cross-talk between these two signalling pathways may affect modulation of the CD molecules on the cell surface of thymocytes. For this purpose, we compare the effects of PMA alone or combined with PGE2 on CD3, CD4 and CD8 expression on mouse thymocytes by flow-cytometric analysis. PMA treatment almost completely abolished CD4 expression and slightly decreased CD3 and CD8 expression. PGE2 alone did not change the CD3, CD4 and CD8 molecule expression. Combined with PMA, PGE2 can overcome the decrease induced by PMA of the CD3 expression and partially reduced the disappearance of the CD4 molecule. On the other hand PGE2 accelerated the loss of CD8 molecule expression. These events occurred only in CD4+ CD8+ immature thymocytes. An analogue of cAMP (dibutyryl cAMP) mimics the effect of PGE2, but not Br-cGMP. This differential regulation by PGE2 of the CD molecule expression on immature thymocytes may provide additional evidence on the role of PGE2 during the process of thymic differentiation.

  17. [Effect of M8046 on expression of COX-2/PGE2 in spinal cord and DRG in rats with neuropathic pain].

    PubMed

    Ou, Guo-Kun; Wang, Rui-Xian; Li, Jia-Jia; Cao, Hong; Lian, Qing-Quan; Li, Jun

    2013-03-01

    To investigate the effects of glucocorticoid receptor antagonist-M8046 on the behavior and the cyclooxygenase-2/prostaglandin E2( COX-2/PGE2) expression in spinal cord dorsal horn and dorsal root ganglia (DRG) in chronic constrictive injury (CCI) rats. One hundred and forty-four male SD rats were randomly divided into 4 groups, 36 rats in each group: Sham operation group (Sham), chronic constrictive group (CCI), M8046 treated group (M8046) and solvent controlled group (Sc). M8046 3 mg/(kg x d) intraperitoneal injection was given after operation in group M8046. Paw thennal withdrawal (PTWL) and paw mechanical withdrawal threshold (PMWT) of rats were measured on 2 pre-operative and 1, 3, 7, 10, 14 post-operative days. The spinal cord and L15 DRG of the operated side was removed at 3, 7, 14 days after surgery. The change of COX-2 and PGE2 expression was determined by immunohistochemical staining and ELISA separately. PTWL and PMWT in CCI group were significantly lower than those in Sham group on every post-operative day (P < 0.05). PTWL and PMWT in M8046 group were significantly higher than those in CCI group on 7, 10, 14 post-operative day (P < 0.05). In spinal dorsal horn, the level of COX-2 and PGE2 expression in CCI group was significantly higher than that in Sham group (P < 0.05). M8046 could significantly attenuate the activation of COX-2 and PGE2 induced by CCI (P < 0.05). The expression of COX-2 and PGE2 in DRG was similar to that in spinal dorsal horn. The effects of M8046 ameliorate the CCI-induced neuropathic pain may be related to attenuate the expression of COX-2 and PGE2 in spinal cord and DRG.

  18. Anti-M(3) muscarinic cholinergic autoantibodies from patients with primary Sjögren's syndrome trigger production of matrix metalloproteinase-3 (MMP-3) and prostaglandin E(2) (PGE(2)) from the submandibular glands.

    PubMed

    Reina, Silvia; Sterin-Borda, Leonor; Passafaro, Daniela; Borda, Enri

    2011-05-01

    We demonstrated that serum immunoglobulin G (IgG) from patients with primary Sjögren's syndrome (pSS), interacting with the second extracellular loop of human glandular M(3) muscarinic acetylcholine receptors (M(3) mAChR), trigger the production of matrix metalloproteinase-3 (MMP-3) and prostaglandin E(2) (PGE(2)). Enzyme-linked immunosorbent assays (ELISAs) were performed in the presence of M(3) mAChR synthetic peptide as antigen to detect in serum the autoantibodies. Further, MMP-3 and PGE(2) production were determined in the presence of anti-M(3) mAChR autoantibodies. An association was observed between serum and anti-M(3) mAChR autoantibodies and serum levels of MMP-3 and PGE(2) in pSS patients. Thus, we established that serum anti-M(3) mAChR autoantibodies, MMP-3 and PGE(2) may be considered to be early markers of pSS associated with inflammation. Affinity-purified anti-M(3) mAChR peptide IgG from pSS patients, whilst stimulating salivary-gland M(3) mAChR, causes an increase in the level of MMP-3 and PGE(2) as a result of the activation of phospholipase A(2) (PLA(2)) and cyclooxygenase-2 (COX-2) (but not COX-1). These results provide a novel insight into the role that cholinoceptor antibodies play in the development of glandular inflammation. This is the first report showing that an antibody interacting with glandular mAChR can induce the production of pro-inflammatory mediators (MMP-3/PGE(2)). Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. PGE2 /EP4 Signaling Controls the Transfer of the Mammary Stem Cell State by Lipid Rafts in Extracellular Vesicles.

    PubMed

    Lin, Meng-Chieh; Chen, Shih-Yin; Tsai, Ho-Min; He, Pei-Lin; Lin, Yen-Chun; Herschman, Harvey; Li, Hua-Jung

    2017-02-01

    Prostaglandin E 2 (PGE 2 )-initiated signaling contributes to stem cell homeostasis and regeneration. However, it is unclear how PGE 2 signaling controls cell stemness. This study identifies a previously unknown mechanism by which PGE 2 /prostaglandin E receptor 4 (EP 4 ) signaling regulates multiple signaling pathways (e.g., PI3K/Akt signaling, TGFβ signaling, Wnt signaling, EGFR signaling) which maintain the basal mammary stem cell phenotype. A shift of basal mammary epithelial stem cells (MaSCs) from a mesenchymal/stem cell state to a non-basal-MaSC state occurs in response to prostaglandin E receptor 4 (EP 4 ) antagonism. EP 4 antagonists elicit release of signaling components, by controlling their trafficking into extracellular vesicles/exosomes in a lipid raft/caveolae-dependent manner. Consequently, EP 4 antagonism indirectly inactivates, through induced extracellular vesicle/exosome release, pathways required for mammary epithelial stem cell homeostasis, e.g. canonical/noncanonical Wnt, TGFβ and PI3K/Akt pathways. EP 4 antagonism causes signaling receptors and signaling components to shift from non-lipid raft fractions to lipid raft fractions, and to then be released in EP 4 antagonist-induced extracellular vesicles/exosomes, resulting in the loss of the stem cell state by mammary epithelial stem cells. In contrast, luminal mammary epithelial cells can acquire basal stem cell properties following ingestion of EP 4 antagonist-induced stem cell extracellular vesicles/exosomes, and can then form mammary glands. These findings demonstrate that PGE 2 /EP 4 signaling controls homeostasis of mammary epithelial stem cells through regulating extracellular vesicle/exosome release. Reprogramming of mammary epithelial cells can result from EP 4 -mediated stem cell property transfer by extracellular vesicles/exosomes containing caveolae-associated proteins, between mammary basal and luminal epithelial cells. Stem Cells 2017;35:425-444. © 2016 The Authors STEM CELLS

  20. Prostaglandin E2 Induces IL-6 and IL-8 Production by the EP Receptors/Akt/NF-κB Pathways in Nasal Polyp-Derived Fibroblasts.

    PubMed

    Cho, Jung-Sun; Han, In-Hye; Lee, Hye Rim; Lee, Heung-Man

    2014-09-01

    Interleukin 6 (IL-6) and IL-8 participate in the pathogenesis of chronic rhinosinusitis with nasal polyps, and their levels are increased by prostaglandin E2 (PGE2) in different cell types. The purposes of this study were to determine whether PGE2 has any effect on the increase in the levels of IL-6 and IL-8 in nasal polyp-derived fibroblasts (NPDFs) and subsequently investigate the possible mechanism of this effect. Different concentrations of PGE2 were used to stimulate NPDFs at different time intervals. NPDFs were treated with agonists and antagonists of E prostanoid (EP) receptors. To determine the signaling pathway for the expression of PGE2-induced IL-6 and IL-8, PGE2 was treated with Akt and NF-κB inhibitors in NPDFs. Reverse transcription-polymerase chain reaction for IL-6 and IL-8 mRNAs was performed. IL-6 and IL-8 levels were measured byenzyme-linked immunosorbent assay (ELISA). The activation of Akt and NF-κB was evaluated by western blot analysis. PGE2 significantly increased the mRNA and protein expression levels of IL-6 and IL-8 in NPDFs. The EP2 and EP4 agonists and antagonists induced and inhibited IL-6 expression. However, the EP4 agonist and antagonist were only observed to induce and inhibit IL-8 expression level. The Akt and NF-κB inhibitors significantly blocked PGE2-induced expression of IL-6 and IL-8. PGE2 increases IL-6 expression via EP2 and EP4 receptors, and IL-8 expression via the EP4 receptor in NPDFs. It also activates the Akt and NF-κB signal pathways for the production of IL-6 and IL-8 in NPDFs. These results suggest that signaling pathway for IL-6 and IL-8 expression induced by PGE2 might be a useful therapeutic target for the treatment of nasal polyposis.

  1. Paracoccidioides brasiliensis interferes on dendritic cells maturation by inhibiting PGE2 production.

    PubMed

    Fernandes, Reginaldo K; Bachiega, Tatiana F; Rodrigues, Daniela R; Golim, Marjorie de A; Dias-Melicio, Luciane A; Balderramas, Helanderson de A; Kaneno, Ramon; Soares, Ângela M V C

    2015-01-01

    Paracoccidioidomycosis (PCM) is a systemic mycosis, endemic in most Latin American countries, especially in Brazil, whose etiologic agent is the thermodimorphic fungus of the genus Paracoccidioides, comprising cryptic species of Paracoccidioides brasiliensis, S1, PS2, PS3 and Paracoccidioides lutzii. The mechanisms involved in the initial interaction of the fungus with cells of the innate immune response, as dendritic cells (DCs), deserve to be studied. Prostaglandins (PGs) are eicosanoids that play an important role in modulating functions of immune cells including DCs. Here we found that human immature DCs derived from the differentiation of monocytes cultured with GM-CSF and IL-4 release substantial concentrations of PGE2, which, however, were significantly inhibited after challenge with P. brasiliensis. In vitro blocking of pattern recognition receptors (PRRs) by monoclonal antibodies showed the involvement of mannose receptor (MR) in PGE2 inhibition by the fungus. In addition, phenotyping assays showed that after challenge with the fungus, DCs do not change their phenotype of immature cells to mature ones, as well as do not produce IL-12 p70 or adequate concentrations of TNF-α. Assays using exogenous PGE2 confirmed an association between PGE2 inhibition and failure of cells to phenotypically mature in response to P. brasiliensis. We conclude that a P. brasiliensis evasion mechanism exists associated to a dysregulation on DC maturation. These findings may provide novel information for the understanding of the complex interplay between the host and this fungus.

  2. Prevotella intermedia induces prostaglandin E2 via multiple signaling pathways.

    PubMed

    Guan, S-M; Fu, S-M; He, J-J; Zhang, M

    2011-01-01

    Prostaglandin E(2) (PGE(2)) plays important roles in the bone resorption of inflammatory diseases such as rheumatoid arthritis and periodontitis via specific prostaglandin receptors (i.e., EP1-EP4). In this study, the authors examined whether Prevotella intermedia regulates PGE(2) production and EP expression in human periodontal ligament fibroblasts (hPDLs); they also explored the potential signaling pathways involved in PGE(2) production. P. intermedia induced PGE(2) production and cyclooxygenase-2 (COX-2) expression in a dose- and time-dependent manner. Indomethacin and NS-398 completely abrogated the P. intermedia-induced PGE(2) production without modulating COX-2 expression. Specific inhibitors of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, phosphatidylinositol 3-kinase, and protein kinase C--but not c-AMP and protein kinase A--significantly attenuated the P. intermedia-induced COX-2 and PGE(2) expression. P. intermedia reduced EP1 expression in a concentration- and time-dependent manner. The results indicate that the COX-2-dependent induction of PGE(2) by P. intermedia in hPDLs is mediated by multiple signaling pathways.

  3. PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells

    PubMed Central

    Bazzani, Lorenzo; Donnini, Sandra; Giachetti, Antonio; Christofori, Gerhard; Ziche, Marina

    2018-01-01

    Prostaglandin E2 (PGE2) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1, PTGS2, MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE2-induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression. PMID:29599917

  4. PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells.

    PubMed

    Bazzani, Lorenzo; Donnini, Sandra; Giachetti, Antonio; Christofori, Gerhard; Ziche, Marina

    2018-03-13

    Prostaglandin E 2 (PGE 2 ) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE 2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE 2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE 2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE 2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1 , PTGS2 , MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE 2 -induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression.

  5. IL-1β Stimulates COX-2 Dependent PGE2 Synthesis and CGRP Release in Rat Trigeminal Ganglia Cells

    PubMed Central

    Neeb, Lars; Hellen, Peter; Boehnke, Carsten; Hoffmann, Jan; Schuh-Hofer, Sigrid; Dirnagl, Ulrich; Reuter, Uwe

    2011-01-01

    Objective Pro-inflammatory cytokines like Interleukin-1 beta (IL-1β) have been implicated in the pathophysiology of migraine and inflammatory pain. The trigeminal ganglion and calcitonin gene-related peptide (CGRP) are crucial components in the pathophysiology of primary headaches. 5-HT1B/D receptor agonists, which reduce CGRP release, and cyclooxygenase (COX) inhibitors can abort trigeminally mediated pain. However, the cellular source of COX and the interplay between COX and CGRP within the trigeminal ganglion have not been clearly identified. Methods and Results 1. We used primary cultured rat trigeminal ganglia cells to assess whether IL-1β can induce the expression of COX-2 and which cells express COX-2. Stimulation with IL-1β caused a dose and time dependent induction of COX-2 but not COX-1 mRNA. Immunohistochemistry revealed expression of COX-2 protein in neuronal and glial cells. 2. Functional significance was demonstrated by prostaglandin E2 (PGE2) release 4 hours after stimulation with IL-1β, which could be aborted by a selective COX-2 (parecoxib) and a non-selective COX-inhibitor (indomethacin). 3. Induction of CGRP release, indicating functional neuronal activation, was seen 1 hour after PGE2 and 24 hours after IL-1β stimulation. Immunohistochemistry showed trigeminal neurons as the source of CGRP. IL-1β induced CGRP release was blocked by parecoxib and indomethacin, but the 5-HT1B/D receptor agonist sumatriptan had no effect. Conclusion We identified a COX-2 dependent pathway of cytokine induced CGRP release in trigeminal ganglia neurons that is not affected by 5-HT1B/D receptor activation. Activation of neuronal and glial cells in the trigeminal ganglion by IL-β leads to an elevated expression of COX-2 in these cells. Newly synthesized PGE2 (by COX-2) in turn activates trigeminal neurons to release CGRP. These findings support a glia-neuron interaction in the trigeminal ganglion and demonstrate a sequential link between COX-2 and CGRP. The

  6. Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term.

    PubMed

    Kelly, Anthony J; Malik, Sidra; Smith, Lee; Kavanagh, Josephine; Thomas, Jane

    2009-10-07

    Prostaglandins have been used for induction of labour since the 1960s. Initial work focused on prostaglandin F2a as prostaglandin E2 was considered unsuitable for a number of reasons. With the development of alternative routes of administration, comparisons were made between various formulations of vaginal prostaglandins. To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol). We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009) and bibliographies of relevant papers. Clinical trials comparing vaginal prostaglandins used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods. We assessed studies and extracted data independently. Sixty-three (10,441 women) have been included.Vaginal prostaglandin E2 compared with placebo or no treatment reduced the likelihood of vaginal delivery not being achieved within 24 hours (18.1% versus 98.9%, risk ratio (RR) 0.19, 95% confidence interval (CI) 0.14 to 0.25, two trials, 384 women). The risk of the cervix remaining unfavourable or unchanged was reduced (21.6% versus 40.3%, RR 0.46, 95% CI 0.35 to 0.62, five trials, 467 women); and the risk of oxytocin augmentation reduced (35.1% versus 43.8%, RR 0.83, 95% CI 0.73 to 0.94, 12 trials, 1321 women) when PGE2 was compared to placebo. There was no evidence of a difference between caesarean section rates, although the risk of uterine hyperstimulation with fetal heart rate changes was increased (4.4% versus 0.49%, RR 4.14, 95% CI 1.93 to 8.90, 14 trials, 1259 women).PGE2 tablet, gel and pessary appear to be as efficacious as each other and the use of sustained release PGE2 inserts appear to be associated with a reduction in instrumental vaginal delivery rates (9.9 % versus 19.5%, RR 0

  7. Prostaglandin E2 Regulates Liver versus Pancreas Cell Fate Decisions and Endodermal Outgrowth

    PubMed Central

    Nissim, Sahar; Sherwood, Richard I.; Wucherpfennig, Julia; Saunders, Diane; Harris, James M.; Esain, Virginie; Carroll, Kelli J.; Frechette, Gregory M.; Kim, Andrew J.; Hwang, Katie L.; Cutting, Claire C.; Elledge, Susanna; North, Trista E.; Goessling, Wolfram

    2014-01-01

    SUMMARY The liver and pancreas arise from common endodermal progenitors. How these distinct cell fates are specified is poorly understood. Here, we describe prostaglandin E2 (PGE2) as a regulator of endodermal fate specification during development. Modulating PGE2 activity has opposing effects on liver-versus-pancreas specification in zebrafish embryos as well as mouse endodermal progenitors. The PGE2 synthetic enzyme cox2a and receptor ep2a are patterned such that cells closest to PGE2 synthesis acquire a liver fate whereas more distant cells acquire a pancreas fate. PGE2 interacts with the bmp2b pathway to regulate fate specification. At later stages of development, PGE2 acting via the ep4a receptor promotes outgrowth of both the liver and pancreas. PGE2 remains important for adult organ growth, as it modulates liver regeneration. This work provides in vivo evidence that PGE2 may act as a morphogen to regulate cell fate decisions and outgrowth of the embryonic endodermal anlagen. PMID:24530296

  8. Interaction between head and neck squamous cell carcinoma cells and fibroblasts in the biosynthesis of PGE2

    PubMed Central

    Alcolea, Sonia; Antón, Rosa; Camacho, Mercedes; Soler, Marta; Alfranca, Arantzazu; Avilés-Jurado, Francesc-Xavier; Redondo, Juan-Miguel; Quer, Miquel; León, Xavier; Vila, Luis

    2012-01-01

    Prostaglandin (PG)E2 is relevant in tumor biology, and interactions between tumor and stroma cells dramatically influence tumor progression. We tested the hypothesis that cross-talk between head and neck squamous cell carcinoma (HNSCC) cells and fibroblasts could substantially enhance PGE2 biosynthesis. We observed an enhanced production of PGE2 in cocultures of HNSCC cell lines and fibroblasts, which was consistent with an upregulation of COX-2 and microsomal PGE-synthase-1 (mPGES-1) in fibroblasts. In cultured endothelial cells, medium from fibroblasts treated with tumor cell-conditioned medium induced in vitro angiogenesis, and in tumor cell induced migration and proliferation, these effects were sensitive to PGs inhibition. Proteomic analysis shows that tumor cells released IL-1, and tumor cell-induced COX-2 and mPGES-1 were suppressed by the IL-1-receptor antagonist. IL-1α levels were higher than those of IL-1β in the tumor cell-conditioning medium and in the secretion from samples obtained from 20 patients with HNSCC. Fractionation of tumor cell-conditioning media indicated that tumor cells secreted mature and unprocessed forms of IL-1. Our results support the concept that tumor-associated fibroblasts are a relevant source of PGE2 in the tumor mass. Because mPGES-1 seems to be essential for a substantial biosynthesis of PGE2, these findings also strengthen the concept that mPGES-1 may be \\a target for therapeutic intervention in patients with HNSCC. PMID:22308510

  9. TLR9 Ligands Induce S100A8 in Macrophages via a STAT3-Dependent Pathway which Requires IL-10 and PGE2

    PubMed Central

    Hsu, Kenneth; Chung, Yuen Ming; Endoh, Yasumi; Geczy, Carolyn L.

    2014-01-01

    S100A8 and S100A9 are highly-expressed calcium-binding proteins in neutrophils and monocytes, and in subsets of macrophages in inflammatory lesions. Unmethylated CpG motifs found in bacterial and viral DNA are potent activators of innate immunity via Toll-like receptor 9 (TLR9). S100A8, but not S100A9, mRNA and protein was directly induced by CpG-DNA in murine and human macrophages. Induction in murine macrophages peaked at 16 h. CpG-DNA-induced S100A8 required de novo protein synthesis; IL-10 and Prostaglandin E2 (PGE2) synergistically enhanced expression and promoted earlier gene induction. Inhibitors of endogenous IL-10, PGE2, and the E prostanoid (EP) 4 receptor strongly suppressed S100A8 expression, particularly when combined. Thus, S100A8 induction by E. coli DNA required both IL-10 and PGE2/EP4 signaling. The MAPKs, PI3K and JAK pathways were essential, whereas ERK1/2 appeared to play a direct role. S100A8 induction by CpG-DNA was controlled at the transcriptional level. The promoter region responsible for activation, either directly, or indirectly via IL-10 and PGE2, was located within a −178 to −34-bp region and required STAT3 binding. Because of the robust links connecting IL-10 and PGE2 with an anti-inflammatory macrophage phenotype, the induction profile of S100A8 strongly indicates a role for this protein in resolution of inflammation. PMID:25098409

  10. TLR9 ligands induce S100A8 in macrophages via a STAT3-dependent pathway which requires IL-10 and PGE2.

    PubMed

    Hsu, Kenneth; Chung, Yuen Ming; Endoh, Yasumi; Geczy, Carolyn L

    2014-01-01

    S100A8 and S100A9 are highly-expressed calcium-binding proteins in neutrophils and monocytes, and in subsets of macrophages in inflammatory lesions. Unmethylated CpG motifs found in bacterial and viral DNA are potent activators of innate immunity via Toll-like receptor 9 (TLR9). S100A8, but not S100A9, mRNA and protein was directly induced by CpG-DNA in murine and human macrophages. Induction in murine macrophages peaked at 16 h. CpG-DNA-induced S100A8 required de novo protein synthesis; IL-10 and Prostaglandin E2 (PGE2) synergistically enhanced expression and promoted earlier gene induction. Inhibitors of endogenous IL-10, PGE2, and the E prostanoid (EP) 4 receptor strongly suppressed S100A8 expression, particularly when combined. Thus, S100A8 induction by E. coli DNA required both IL-10 and PGE2/EP4 signaling. The MAPKs, PI3K and JAK pathways were essential, whereas ERK1/2 appeared to play a direct role. S100A8 induction by CpG-DNA was controlled at the transcriptional level. The promoter region responsible for activation, either directly, or indirectly via IL-10 and PGE2, was located within a -178 to -34-bp region and required STAT3 binding. Because of the robust links connecting IL-10 and PGE2 with an anti-inflammatory macrophage phenotype, the induction profile of S100A8 strongly indicates a role for this protein in resolution of inflammation.

  11. PGE(2) inhibition of TGF-beta1-induced myofibroblast differentiation is Smad-independent but involves cell shape and adhesion-dependent signaling.

    PubMed

    Thomas, Peedikayil E; Peters-Golden, Marc; White, Eric S; Thannickal, Victor J; Moore, Bethany B

    2007-08-01

    Myofibroblasts are pathogenic in pulmonary fibrotic disease due to their exuberant production of matrix rich in collagen that interferes with gas exchange and the ability of these cells to contract and distort the alveolar space. Transforming growth factor-beta1 (TGF-beta1) is a well-known inducer of myofibroblast differentiation. TGF-beta1-induced transformation of fibroblasts to apoptosis-resistant myofibroblasts is adhesion-dependent and focal adhesion kinase (FAK)-mediated. Prostaglandin E(2) (PGE(2)) inhibits this differentiation via E prostanoid receptor 2 (EP2) signaling and cAMP elevation, but whether PGE(2) does so by interfering with TGF-beta1 signaling is unknown. Thus we examined the effects of PGE(2) in the presence and absence of TGF-beta1 stimulation on candidate signaling pathways in human lung fibroblasts. We now demonstrate that PGE(2) does not interfere with TGF-beta1-induced Smad phosphorylation or its translocation to the nucleus. Rather, PGE(2) has dramatic effects on cell shape and cytoskeletal architecture and disrupts the formation of appropriate focal adhesions. PGE(2) treatment diminishes TGF-beta1-induced phosphorylation of paxillin, STAT-3, and FAK and, in turn, limits activation of the protein kinase B (PKB/Akt) pathway. These alterations do not, however, result in increased apoptosis within the first 24 h of treatment. Interestingly, the effects of PGE(2) stimulation alone do not always mirror the effects of PGE(2) in the presence of TGF-beta1, indicating that the context for EP2 signaling is different in the presence of TGF-beta1. Taken together, our results demonstrate that PGE(2) has the potential to limit TGF-beta1-induced myofibroblast differentiation via adhesion-dependent, but Smad-independent, pathways.

  12. Genetic variability of prostaglandin E2 receptor subtype EP4 gene in aspirin-intolerant chronic urticaria.

    PubMed

    Palikhe, Nami Shrestha; Sin, Hye Jung; Kim, Seung Hyun; Sin, Hyun Jung; Hwang, Eui Kyung; Ye, Young Min; Park, Hae-Sim

    2012-08-01

    Prostaglandin E2 receptor subtype EP4 (PTGER4) is one of the four subtypes of receptors for prostaglandin E2 (PGE2). Overproduction of cysteinyl leukotriene in mast cells may be related with suppression of PGE2 in patients with aspirin hypersensitivity. Considering the association of PTGER4 in mast cells, urticaria- and aspirin-related disease, we hypothesized the genetic variability of PTGER4 may be associated with aspirin-intolerant chronic urticaria (AICU). The case-control study was performed in 141 with AICU, 153 with aspirin-tolerant chronic urticaria (ATCU) and 174 with normal controls (NCs). PTGER4 promoter single-nucleotide polymorphism was genotyped using a primer extension method with the SNAPshot ddNTP primer extension kit. The functional variability of PTGER4 promoter polymorphism was carried out by dual-luciferase system and electrophoretic mobility shift assay (EMSA) in human mast cells (HMC-1). Furthermore, the effect of aspirin was performed for PTGER4 mRNA expression using real-time PCR, and PGE2 production was checked in HMC-1 cells using ELISA. AICU patients carrying GG genotype at -1254 G>A showed significantly higher frequency compared with NC (P=0.032). Similarly, the minor allele frequency, G allele was significantly higher in AICU compared with NC (P=0.031). In vitro functional study demonstrated that the -1254 G allele had lower luciferase activity (P<0.001) in HMC-1 cells. EMSA finding showed that PTGER4 -1254 G produced a specific band. Significantly decreased PTGER4 expression (P=0.008) and PGE2 production by aspirin exposure was confirmed in in vitro HMC cell line model (P=0.001). The PTGER4 -1254 G allele demonstrated a higher frequency in AICU patients and lower promoter activity with decreased expression of PTGER4 and contributes to the development of AICU.

  13. Intracrine prostaglandin E2 pro-tumoral actions in prostate epithelial cells originate from non-canonical pathways.

    PubMed

    Madrigal-Martínez, Antonio; Fernández-Martínez, Ana B; Lucio Cazaña, Francisco J

    2018-04-01

    Prostaglandin E 2 (PGE 2 ) increases cell proliferation and stimulates migratory and angiogenic abilities in prostate cancer cells. However, the effects of PGE 2 on non-transformed prostate epithelial cells are unknown, despite the fact that PGE 2 overproduction has been found in benign hyperplastic prostates. In the present work we studied the effects of PGE 2 in immortalized, non-malignant prostate epithelial RWPE-1 cells and found that PGE 2 increased cell proliferation, cell migration, and production of vascular endothelial growth factor-A, and activated in vitro angiogenesis. These actions involved a non-canonic intracrine mechanism in which the actual effector was intracellular PGE 2 (iPGE 2 ) instead of extracellular PGE 2 : inhibition of the prostaglandin uptake transporter (PGT) or antagonism of EP receptors prevented the effects of PGE 2 , which indicated that PGE 2 activity depended on its carrier-mediated translocation from the outside to the inside of cells and that EP receptors located intracellularly (iEP) mediated the effects of PGE 2 . iPGE 2 acted through transactivation of epidermal growth factor-receptor (EGFR) by iEP, leading to increased expression and activity of hypoxia-inducible factor-1α (HIF-1α). Interestingly, iPGE 2 also mediates the effects of PGE 2 on prostate cancer PC3 cells through the axis iPGE 2 -iEP receptors-EGFR-HIF-1α. Thus, this axis might be responsible for the growth-stimulating effects of PGE 2 on prostate epithelial cells, thereby contributing to prostate proliferative diseases associated with chronic inflammation. Since this PGT-dependent non-canonic intracrine mechanism of PGE 2 action operates in both benign and malignant prostate epithelial cells, PGT inhibitors should be tested as a novel therapeutic modality to treat prostate proliferative disease. © 2017 Wiley Periodicals, Inc.

  14. mPGES-1-derived PGE2 mediates dehydration natriuresis

    PubMed Central

    Jia, Zhanjun; Liu, Gang; Sun, Ying; Kakizoe, Yutaka; Guan, Guangju; Zhang, Aihua; Zhou, Shu-Feng

    2013-01-01

    PGE2 is a natriuretic factor whose production is elevated after water deprivation (WD) but its role in dehydration natriuresis is not well-defined. The goal of the present study was to investigate the role of microsomal prostaglandin E synthase-1 (mPGES-1) in dehydration natriuresis. After 24-h WD, wild-type (WT) mice exhibited a significant increase in 24-h urinary Na+ excretion accompanied with normal plasma Na+ concentration and osmolality. In contrast, WD-induced elevation of urinary Na+ excretion was completely abolished in mPGES-1 knockout (KO) mice in parallel with increased plasma Na+ concentration and a trend increase in plasma osmolality. WD induced a 1.8-fold increase in urinary PGE2 output and a 1.6-fold increase in PGE2 content in the renal medulla of WT mice, both of which were completely abolished by mPGES-1 deletion. Similar patterns of changes were observed for urinary nitrate/nitrite and cGMP. The natriuresis in dehydrated WT mice was associated with a significant downregulation of renal medullary epithelial Na channel-α mRNA and protein, contrasting to unaltered expressions in dehydrated KO mice. By quantitative RT-PCR, WD increased the endothelial nitric oxide synthase (eNOS), inducible NOS, and neuronal NOS expressions in the renal medulla of WT mice by 3.9-, 1.48-, and 2.6-fold, respectively, all of which were significantly blocked in mPGES-1 KO mice. The regulation of eNOS expression was further confirmed by immunoblotting. Taken together, our results suggest that mPGES-1-derived PGE2 contributes to dehydration natriuresis likely via NO/cGMP. PMID:23171554

  15. Sequence analysis and identification of new isoform of EP4 receptors in different atlantic salmon tissues (Salmo salar L.) and its role in PGE2 induced immunomodulation in vitro.

    PubMed

    Guo, Tz Chun; Gamil, Amr Ahmed Abdelrahim; Koenig, Melanie; Evensen, Øystein

    2015-01-01

    PGE2 plays an important role in a broad spectrum of physiological and pathological processes mediated through a membrane-bound G protein-coupled receptor (GPCR) called EP receptor. In mammals, four subtypes of EP receptor (EP 1-4) are identified and each of them functions through different signal transduction pathways. Orthologous EP receptors have also been identified in other non-mammalian species, such as chicken and zebrafish. EP4 is the only identified PGE2 receptor to date in Atlantic salmon but its tissue distribution and function have not been studied in any detail. In this study, we first sequenced EP4 receptor in different tissues and found that the presence of the 3nt deletion in the 5' untranslated region was accompanied by silent mutation at nt 668. While attempting to amplify the same sequence in TO cells (an Atlantic salmon macrophage-like cell line), we failed to obtain the full-length product. Further investigation revealed different isoform of EP4 receptor in TO cells and we subsequently documented its presence in different Atlantic salmon tissues. These two isoforms of EP4 receptor share high homology in their first half of sequence but differ in the second half part with several deletion segments though the final length of coding sequence is the same for two isoforms. We further studied the immunomodulation effect of PGE2 in TO cells and found that PGE2 inhibited the induction of CXCL-10, CCL-4, IL-8 and IL-1β genes expression in a time dependent manner and without cAMP upregulation.

  16. The prostaglandin E2 E-prostanoid 4 receptor exerts anti-inflammatory effects in brain innate immunity.

    PubMed

    Shi, Ju; Johansson, Jenny; Woodling, Nathaniel S; Wang, Qian; Montine, Thomas J; Andreasson, Katrin

    2010-06-15

    Peripheral inflammation leads to immune responses in brain characterized by microglial activation, elaboration of proinflammatory cytokines and reactive oxygen species, and secondary neuronal injury. The inducible cyclooxygenase (COX), COX-2, mediates a significant component of this response in brain via downstream proinflammatory PG signaling. In this study, we investigated the function of the PGE2 E-prostanoid (EP) 4 receptor in the CNS innate immune response to the bacterial endotoxin LPS. We report that PGE2 EP4 signaling mediates an anti-inflammatory effect in brain by blocking LPS-induced proinflammatory gene expression in mice. This was associated in cultured murine microglial cells with decreased Akt and I-kappaB kinase phosphorylation and decreased nuclear translocation of p65 and p50 NF-kappaB subunits. In vivo, conditional deletion of EP4 in macrophages and microglia increased lipid peroxidation and proinflammatory gene expression in brain and in isolated adult microglia following peripheral LPS administration. Conversely, EP4 selective agonist decreased LPS-induced proinflammatory gene expression in hippocampus and in isolated adult microglia. In plasma, EP4 agonist significantly reduced levels of proinflammatory cytokines and chemokines, indicating that peripheral EP4 activation protects the brain from systemic inflammation. The innate immune response is an important component of disease progression in a number of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In addition, recent studies demonstrated adverse vascular effects with chronic administration of COX-2 inhibitors, indicating that specific PG signaling pathways may be protective in vascular function. This study supports an analogous and beneficial effect of PGE2 EP4 receptor signaling in suppressing brain inflammation.

  17. CD40 engagement on dendritic cells induces cyclooxygenase-2 and EP2 receptor via p38 and ERK MAPKs.

    PubMed

    Harizi, Hedi; Limem, Ilef; Gualde, Norbert

    2011-02-01

    We have previously reported that cyclooxygenase (COX)-2-derived prostaglandin (PG)E2 critically regulates dendritic cell (DC) inflammatory phenotype and function through EP2/EP4 receptor subtypes. As genes activated by CD40 engagement are directly relevant to inflammation, we examined the effects of CD40 activation on inflammatory PGs in murine bone marrow-derived DC (mBM-DC). We showed for the first time that activation of mBM-DC with agonist anti-CD40 monoclonal antibody (anti-CD40 mAb) dose dependently induces the synthesis of significant amounts of PGE2 via inducible expression of COX-2 enzyme, as NS-398, a COX-2-selective inhibitor reduces this upregulation. In contrast to lipopolysaccharide, which upregulates mBM-DC surface levels of EP2 and EP4 receptors, CD40 crosslinking on mBM-DC increases EP2, but not EP4, receptor expression. Flow cytometry analysis and radioligand-binding assay showed that EP2 was the major EP receptor subtype, which binds to PGE2 at the surface of anti-CD40-activated mBM-DC. Upregulation of COX-2 and EP2 levels by CD40 engagement was accompanied by dose-dependent phosphorylation of p38 and ERK1/2 mitogen-activated protein kinase (MAPK) and was abrogated by inhibitors of both pathways. Collectively, we demonstrated that CD40 engagement on mBM-DC upregulates COX-2 and EP2 receptor expression through activation of p38 and ERK1/2 MAPK signaling. Triggering the PGE2/EP2 pathway by anti-CD40 mAb resulted on the induction of Th2 immune response. Thus, CD40-induced production of PGE2 by mBM-DC could represent a negative feedback mechanism involving EP2 receptor and limiting the propagation of Th1 responses. Blocking CD40 pathway may represent a novel therapeutic pathway of inhibiting COX-2-derived prostanoids in chronically inflamed tissues (that is, arthritis).

  18. Inhibition of microsomal prostaglandin E-synthase-1 (mPGES-1) selectively suppresses PGE2 in an in vitro equine inflammation model.

    PubMed

    Martin, Emily M; Jones, Samuel L

    2017-10-01

    Inhibition of prostaglandin E 2 (PGE 2 ) production effectively limits inflammation in horses, however nonspecific prostaglandin blockade via cyclooxygenase (COX) inhibition elicits deleterious gastrointestinal side effects in equine patients. Thus, more selective PGE 2 targeting therapeutics are needed to treat inflammatory disease in horses. One potential target is microsomal prostaglandin E-synthase-1 (mPGES-1), which is the terminal enzyme downstream of COX-2 in the inducible PGE 2 synthesis cascade. This enzyme has yet to be studied in equine leukocytes, which play a pivotal role in equine inflammatory disease. The objective of this study was to determine if mPGES-1 is a PGE 2 -selective anti-inflammatory target in equine leukocytes. To evaluate this objective, leukocyte-rich plasma (LRP) was isolated from equine whole blood collected via jugular venipuncture of six healthy adult horses of mixed breeds and genders. LRP was primed with granulocyte-monocyte colony-stimulating factor (GM-CSF) and stimulated with lipopolysaccharide (LPS) in the presence or absence of an mPGES-1 inhibitor (MF63), a COX-2 inhibitor (NS-398), or a nonselective COX inhibitor (indomethacin). Following treatment, mPGES-1 and COX-2 mRNA and protein levels were measured via qPCR and western blot, respectively, and PGE 2 , thromboxane (TXA 2 ) and prostacyclin (PGI 2 ) levels were measured in cellular supernatants via ELISA. This study revealed that LPS significantly increased mPGES-1 mRNA, but not protein levels in equine LRP as measured by qPCR and western blot, respectively. In contrast, COX-2 mRNA and protein were coordinately induced by LPS. Importantly, treatment of LPS-stimulated leukocytes with indomethacin and NS-398 significantly reduced extracellular concentrations of multiple prostanoids (PGE 2 , TXA 2 and PGI 2 ), while the mPGES-1 inhibitor MF63 selectively inhibited PGE 2 production only. mPGES-1 inhibition also preserved higher basal levels of PGE 2 production when compared

  19. The H(2)-receptor antagonist ranitidine interferes with clopidogrel-mediated P2Y(12) inhibition in platelets.

    PubMed

    Schäfer, Andreas; Flierl, Ulrike; Pförtsch, Stephanie; Seydelmann, Nora; Micka, Jan; Bauersachs, Johann

    2010-10-01

    Use of proton-pump inhibitors (PPIs) is common in patients on dual antiplatelet therapy (DAT). Recent warnings about potential interactions of PPIs with clopidogrel metabolism leading to impaired DAT efficacy has prompted the recommendation of substituting PPIs with H(2)-receptor antagonists such as ranitidine. We investigated whether ranitidine interacts with P2Y(12) inhibition on the platelet level. Blood was collected from 15 patients with stable coronary artery disease, who had undergone elective coronary intervention. Clopidogrel responsiveness was assessed 24h after the administration of a 600mg loading dose using the P2Y(12) specific platelet-reactivity-index (PRI) and light-transmittance aggregometry in the presence and absence of a pharmacologically relevant concentration of the H(2)-receptor antagonist ranitidine (400ng/ml). Adding ranitidine enhanced P2Y(12)-mediated platelet reactivity to ADP assessed by the PRI (mean PRI+/-SEM: before ranitidine 28+/-5%; after ranitidine 37+/-5%, p=0.0025). Similarly, prostaglandin E1 (PGE(1))-mediated inhibition of ADP-induced aggregation was abrogated in the presence of ranitidine (Agg(max)+/-SEM: before PGE(1) 41+/-2%; after PGE(1) 29+/-2%, p<0.01 vs. before PGE(1); after PGE(1)+ranitidine 42+/-2%, p<0.01 vs. after PGE(1)). Exposition of platelets with ranitidine significantly enhanced their responsiveness to ADP and contributed to impaired P2Y(12) inhibition suggesting that ranitidine interacts with clopidogrel efficacy through adenylyl cyclase inhibition on the platelet level. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Characterization of prostaglandin E2 generation through the cyclooxygenase (COX)-2 pathway in human neutrophils

    PubMed Central

    St-Onge, Mireille; Flamand, Nicolas; Biarc, Jordane; Picard, Serge; Bouchard, Line; Dussault, Andrée-Anne; Laflamme, Cynthia; James, Michael J.; Caughey, Gillian E.; Cleland, Leslie G.; Borgeat, Pierre; Pouliot, Marc

    2010-01-01

    In the present study, we characterized the generation of prostaglandin (PG)E2 in human neutrophils. We found that the Ca2+-dependent type IV cytosolic phospholipase A2 (cPLA2) was pivotally involved in the COX-2-mediated generation of PGE2 in response to a calcium ionophore, as determined by the use of selected PLA2 inhibitors. PGE2 biosynthesis elicited by bacterial-derived peptides or by phagocytic stimuli acting on cell surface receptors also showed to be dependent on cPLA2 activity. We then assessed metabolism of unesterified arachidonic acid (AA), and observed that PGE2 production becomes favored over that of LTB4 with higher AA concentrations. Withdrawal of calcium prevented the generation of PGE2 in response to a calcium ionophore but did not affect the up-regulation of COX-2 or its capacity to convert AA, thus limiting its implication at the level of cPLA2 activation. Of the main eicosanoids produced by neutrophils, only LTB4 was able to up-regulate COX-2 expression. Finally, the only PGE synthase isoform found in neutrophils is microsomal PGE synthase-1; it co-localized with COX-2 and its expression appeared mainly constitutive. These results highlight key differences in regulatory processes of the 5-LO and COX pathways, and enhance our knowledge at several levels in the PGE2 biosynthesis in neutrophils. PMID:17643350

  1. Effects of intraluteal implants of prostaglandin E1 or E2 on angiogenic growth factors in luteal tissue of Angus and Brahman cows.

    PubMed

    Weems, Yoshie S; Ma, Yan; Ford, Stephen P; Nett, Terry M; Vann, Rhonda C; Lewis, Andrew W; Neuendorff, Don A; Welsh, Thomas H; Randel, Ronald D; Weems, Charles W

    2014-12-01

    Previously, it was reported that intraluteal implants containing prostaglandin E1 or E2 (PGE1 and PGE2) in Angus or Brahman cows prevented luteolysis by preventing loss of mRNA expression for luteal LH receptors and luteal unoccupied and occupied LH receptors. In addition, intraluteal implants containing PGE1 or PGE2 upregulated mRNA expression for FP prostanoid receptors and downregulated mRNA expression for EP2 and EP4 prostanoid receptors. Luteal weight during the estrous cycle of Brahman cows was reported to be lesser than that of Angus cows but not during pregnancy. The objective of this experiment was to determine whether intraluteal implants containing PGE1 or PGE2 alter vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), angiopoietin-1 (ANG-1), and angiopoietin-2 (ANG-2) protein in Brahman or Angus cows. On Day 13 of the estrous cycle, Angus cows received no intraluteal implant and corpora lutea were retrieved, or Angus and Brahman cows received intraluteal silastic implants containing vehicle, PGE1, or PGE2 on Day 13 and corpora lutea were retrieved on Day 19. Corpora lutea slices were analyzed for VEGF, FGF-2, ANG-1, and ANG-2 angiogenic proteins via Western blot. Day-13 Angus cow luteal tissue served as preluteolytic controls. Data for VEGF were not affected (P > 0.05) by day, breed, or treatment. PGE1 or PGE2 increased (P < 0.05) FGF-2 in luteal tissue of Angus cows compared with Day-13 and Day-19 Angus controls but decreased (P < 0.05) FGF-2 in luteal tissue of Brahman cows when compared w Day-13 or Day-19 Angus controls. There was no effect (P > 0.05) of PGE1 or PGE2 on ANG-1 in Angus luteal tissue when compared with Day-13 or Day-19 controls, but ANG-1 was decreased (P < 0.05) by PGE1 or PGE2 in Brahman cows when compared with Day-19 Brahman controls. ANG-2 was increased (P < 0.05) on Day 19 in Angus Vehicle controls when compared with Day-13 Angus controls, which was prevented (P < 0.05) by PGE1 but not by PGE2 in Angus

  2. Compressive force induces osteoclast differentiation via prostaglandin E(2) production in MC3T3-E1 cells.

    PubMed

    Sanuki, Rina; Shionome, Chieko; Kuwabara, Akiko; Mitsui, Narihiro; Koyama, Yuki; Suzuki, Naoto; Zhang, Fan; Shimizu, Noriyoshi; Maeno, Masao

    2010-04-01

    In orthodontic tooth movement, prostaglandin E(2) (PGE(2)) released from osteoblasts can alter the normal process of bone remodeling. We previously showed that compressive force (CF) controls bone formation by stimulating the production of PGE(2) and Ep2 and/or Ep4 receptors in osteoblasts. The present study was undertaken to examine the effect of CF on the production of PGE(2), cyclooxygenase-2 (COX-2), macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL), and osteoprotegerin (OPG) using osteoblastic MC3T3-E1 cells and to examine the indirect effect of CF on osteoclast differentiation using RAW264.7 cells as osteoclast precursors. MC3T3-E1 cells were cultured with or without continuous CF (1.0 or 3.0 g/cm(2)) for 24 hr, and PGE(2) production was determined using ELISA. The expression of COX-2, M-CSF, RANKL, and OPG genes and proteins was determined using real-time PCR and ELISA, respectively. Osteoclast differentiation was estimated using tartrate-resistant acid phosphatase (TRAP) staining of RAW 264.7 cells cultured for 10 days with conditioned medium from CF-treated MC3T3-E1 cells and soluble RANKL. As CF increased, PGE(2) production and the expression of COX-2, M-CSF, and RANKL increased, whereas OPG expression decreased. The number of TRAP-positive cells increased as CF increased. Celecoxib, a specific inhibitor of COX-2, blocked the stimulatory effect of CF on TRAP staining and the production of PGE(2), M-CSF, RANKL, and OPG. These results suggest that CF induces osteoclast differentiation by increasing M-CSF production and decreasing OPG production via PGE(2) in osteoblasts.

  3. Bromelain treatment leads to maturation of monocyte-derived dendritic cells but cannot replace PGE2 in a cocktail of IL-1β, IL-6, TNF-α and PGE2.

    PubMed

    Karlsen, M; Hovden, A-O; Vogelsang, P; Tysnes, B B; Appel, S

    2011-08-01

    Immunotherapy using dendritic cells (DC) has shown promising results. However, the use of an appropriate DC population is critical for the outcome of this treatment, and the search for an optimal DC subset is still ongoing. The DC used in immunotherapy today are usually matured with a cytokine cocktail consisting of TNF-α, IL-1β, IL-6 and PGE(2). These cells have deficits in their cytokine production, particularly IL-12p70, mainly because of the presence of PGE(2). Bromelain is a pineapple stem extract containing a mixture of proteases that has been used clinically in adjuvant cancer treatment. In this study, we analysed the effect of bromelain on human monocyte-derived DC. We added bromelain to the cytokine cocktail and modified cytokine cocktails with either no PGE(2) or reduced amounts of PGE(2), respectively. Combining bromelain with the cytokine cocktails containing PGE(2) resulted in an increased surface expression of CD83, CD80 and CD86. The chemokine receptor CCR7 was also considerably upregulated in these DC populations compared with DC treated with the cytokine cocktail alone. Removal or reduction of PGE(2) from the cytokine cocktail did not increase the IL-12p70 secretion from stimulated DC, and addition of bromelain to the different cytokine cocktails resulted in only a minor increase in IL-12p70 production. Moreover, combining bromelain with the cytokine cocktails did not improve the T cell stimulatory capacity of the generated DC populations. In conclusion, bromelain treatment of monocyte-derived DC does not improve the functional quality compared with the standard cytokine cocktail. © 2011 The Authors. Scandinavian Journal of Immunology © 2011 Blackwell Publishing Ltd.

  4. Effect of LTB4 on the inhibition of natural cytotoxic activity by PGE2.

    PubMed

    Vaillier, D; Daculsi, R; Gualde, N; Bezian, J H

    1992-01-01

    NK activity is regulated by arachidonic acid metabolites. More precisely PGE2 and LTB4 decreases and increases respectively non-MHC-restricted cytotoxicity in humans. We have observed similar data in mice since NK activity was inhibited by PGE2 (10(-6) to 10(-8) M) and enhanced by LTB4 (10(-8) to 10(-12) M). On the other hand when PGE2 and LTB4 were combined during the same assay the lysis percentage was smaller than the one which was induced by PGE2 alone. Because PGE2 increases intracellular cyclic AMP and that LTB4 augments cyclic GMP we used a cAMP inducer (forskolin) and a cGMP analogue (8 Br-cGMP) instead of eicosanoids and we observed similar data (i.e., a decrease of natural killing) as when PGE2 was combined with LTB4. When splenocytes are cultured for 1-4 days alone, cytotoxic activity decreases unless they are cultured in the presence of indomethacin. Cytotoxic activity of spleen cells cultured in the presence of PGE2 or LTB4 is respectively decreased or increased. However, splenocytes that were cultured alone for at least 24 hr were no longer sensitive to inhibition by PGE2 but were still PGE2-sensitive when cultured in the presence of LTB4.

  5. Intraluteal prostaglandin biosynthesis and signaling are selectively directed towards PGF2alpha during luteolysis but towards PGE2 during the establishment of pregnancy in sheep.

    PubMed

    Lee, JeHoon; McCracken, John A; Stanley, Jone A; Nithy, Thamizh K; Banu, Sakhila K; Arosh, Joe A

    2012-10-01

    In ruminants, endometrial prostalgandin (PG) F(2alpha) causes functional luteolysis, whereas luteal synthesis of PGF(2alpha) is required for structural luteolysis. PGE(2) is considered to be a luteoprotective mediator. Molecular aspects of luteal PGF(2alpha) and PGE(2) biosynthesis and signaling during the estrous cycle and establishment of pregnancy are largely unknown. The objectives of the present study were 1) to determine the regulation of proteins involved in PGF(2alpha) and PGE(2) biosynthesis, catabolism, transport and signaling in the corpus luteum (CL); 2) to investigate the transport of interferon tau (IFNT), PGF(2alpha), and PGE(2) from the uterus to the ovary through the vascular utero-ovarian plexus (UOP); and 3) to compare the intraluteal production of PGF(2alpha) and PGE(2) on Days 12, 14, and 16 of the estrous cycle and pregnancy in sheep. Our results indicate that luteal PG biosynthesis is selectively directed towards PGF(2alpha) at the time of luteolysis and towards PGE(2) during the establishment of pregnancy. Moreover, the ability of the CL of early pregnancy to resist luteolysis is due to increased intraluteal biosynthesis of PGE(2) and PGE(2) receptor (PTGER) 2 (also known as EP2)- and PTGER4 (also known as EP4)-mediated signaling. We also found that IFNT protein is not transported through the UOP from the uterus to the ovary; in contrast, a large proportion of endometrial PGE(2) is transported from the uterus to the ovary through the UOP. These results indicate that endometrial PGE(2) stimulated by pregnancy is transported locally to the ovary, which increases luteal PGE(2) biosynthesis and hence activates luteal PTGER2 and PTGER4 signaling, thus protecting the CL during the establishment of pregnancy in sheep.

  6. Expression of vitamin D receptor (VDR), cyclooxygenase-2 (COX-2) and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in benign and malignant ovarian tissue and 25-hydroxycholecalciferol (25(OH2)D3) and prostaglandin E2 (PGE2) serum level in ovarian cancer patients.

    PubMed

    Thill, Marc; Fischer, Dorothea; Kelling, Katharina; Hoellen, Friederike; Dittmer, Christine; Hornemann, Amadeus; Salehin, Darius; Diedrich, Klaus; Friedrich, Michael; Becker, Steffi

    2010-07-01

    Ovarian carcinomas are associated with increased inflammation which is based upon an up-regulation of inducible cyclooxygenase-2 (COX-2). Moreover, based on our previous published data, the extra-renal vitamin D metabolism seems to be dysregulated in comparison to healthy tissue. In order to gain further insight into the prostaglandin (PG)- and vitamin D-metabolism in ovarian carcinomas, the study aimed to evaluate the expression of the PG metabolising enzymes COX-2 and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) compared to the vitamin D receptor (VDR) in benign and malignant ovarian tissues. Additionally, we determined the 25-hydroxycholecalciferol (25(OH2)D3) serum levels. Expression of VDR, COX-2 and 15-PGDH was determined by Western blot analysis. Serum levels of 25(OH2)D3 and PGE2 were measured by chemiluminescence-based and colorimetric immunoassay. We detected significantly higher expressions of the PG metabolising enzymes 15-PGDH and COX-2 in malignant tissue and PGE2 serum levels were 2-fold higher in tumour patients. Furthermore, we found an inverse correlation to the VDR-expression which was 62.1% lower in malignant tissues compared to that in benign tissues. Surprisingly, we could not detect any differences between the 25(OH2)D3 serum levels in either group (n=20). These data suggest a correlation between PG- and vitamin D-metabolism in ovarian carcinomas. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  7. Changes in PGE2 signaling after submandibulectomy alter post-tooth extraction socket healing.

    PubMed

    Mohn, Claudia Ester; Troncoso, Gastón Rodolfo; Bozzini, Clarisa; Conti, María Inés; Fernandez Solari, Javier; Elverdin, Juan Carlos

    2018-03-10

    Saliva is very important to oral health, and a salivary deficit has been shown to bring serious problems to oral health. There is scant information about the mechanisms through which salivary glands participate in post-tooth extraction socket healing. Therefore, the aim of the present study was to investigate the effect of submandibulectomy (SMx), consisting of the ablation of submandibular and sublingual glands (SMG and SLG, respectively), on PGE 2 signaling and other bone regulatory molecules, such as OPG and RANKL, involved in tooth extraction socket healing. Male Wistar rats, 70 g body weight, were assigned to an experimental (subjected to SMx) or a control group (sham operated). One week later, the animals in both groups underwent bilateral extraction of the first mandibular molars. The effect of SMx on different stages of socket healing after tooth extraction (7, 14, and 30 days) was studied by evaluating some parameters of inflammation, including PGE 2 and its receptors, and of bone metabolism, as well as by performing bone biomechanical studies. SMx increased TNFα and PGE 2 content as well as cyclooxygenase-II (COX-II) expression in tooth socket tissue at almost all the studied time points. SMx also had an effect on mRNA expression of PGE 2 receptors at the different time points, but did not significantly alter osteoprotegerin (OPG) and RANKL mRNA expression at any of the studied time points. In addition, an increase in bone mass density was observed in SMx rats compared with matched controls, and the structural and mechanical bone properties of the mandibular socket bone were also affected by SMx. Our results suggest that the SMG/SLG complex regulates cellular activation and differentiation by modulating the production of molecules intervening in tooth extraction socket repair, including the PGE 2 signaling system, which would therefore account for the higher density and resistance of the newly formed bone in SMx rat. © 2018 by the Wound Healing Society.

  8. The effects of increasing PGE2 on translocation of labeled albumin into rat brain.

    PubMed

    Messripour, M; Mesripour, A; Mashayekhie, F J

    2015-01-01

    Under pathophysiological conditions, infiltration of leukocyte plays a key role in the progression of the neuroinflammatory reaction in the CNS. Prostaglandin E2 (PGE2) is known to accumulate at lesion sites of the post-ischemic brain. Although post-ischemic treatments with cyclooxygenase-2 inhibitors reduce blood-brain barrier (BBB) leukocyte infiltration, the direct effect of PGE2 on BBB has not been fully implemented. Therefore, the direct effect of increasing PGE2 infusion on translocation of labeled albumin into the brain was assessed. Under anesthesia rats were drilled stereo-taxicaly a burr hole in the right forebrain and PGE2 was infused into the forebrain and the hole was occluded. The animals were then injected with fluorescent labeled albumin (FA), via internal right jugular vein and decapitated at different infusion time points. The forebrain was removed and each forebrain hemisphere was homogenized and fluorescence intensities were measured in the supernatant. The fluorescence intensities measured in the right and left forebrain hemispheres of the control group (0.0 μg PGE2) were almost identical. Four hours after infusion of PGE2 at doses higher than 250 μg, fluorescence intensity increased in the right forebrain supernatant, even if it was not statistically significant. The fluorescence intensity was detectable in the brain supernatant 4 h after infusion of PGE2 in doses higher than 250 μg PGE2. The highest fluorescence intensity was 16 h after infusion of 500 μg PGE2, which returned to near control values after 48 h. Increased fluorescence intensity in the brain following PGE2 infusion is concluded to be associated with disruption of the BBB.

  9. Apigenin inhibits COX-2, PGE2, and EP1 and also initiates terminal differentiation in the epidermis of tumor bearing mice.

    PubMed

    Kiraly, Alex J; Soliman, Eman; Jenkins, Audrey; Van Dross, Rukiyah T

    2016-01-01

    Non-melanoma skin cancer (NMSC) is the most prevalent cancer in the United States. NMSC overexpresses cyclooxygenase-2 (COX-2). COX-2 synthesizes prostaglandins such as PGE2 which promote proliferation and tumorigenesis by engaging G-protein-coupled prostaglandin E receptors (EP). Apigenin is a bioflavonoid that blocks mouse skin tumorigenesis induced by the chemical carcinogens, 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). However, the effect of apigenin on the COX-2 pathway has not been examined in the DMBA/TPA skin tumor model. In the present study, apigenin decreased tumor multiplicity and incidence in DMBA/TPA-treated SKH-1 mice. Analysis of the non-tumor epidermis revealed that apigenin reduced COX-2, PGE2, EP1, and EP2 synthesis and also increased terminal differentiation. In contrast, apigenin did not inhibit the COX-2 pathway or promote terminal differentiation in the tumors. Since fewer tumors developed in apigenin-treated animals which contained reduced epidermal COX-2 levels, our data suggest that apigenin may avert skin tumor development by blocking COX-2. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effect of PGE2 on thymocyte proliferation induced by Con A or IL-4 + PMA.

    PubMed

    Daculsi, R; Vaillier, D; Bezian, J H; Gualde, N

    1993-02-01

    Prostaglandin E2 (PGE2) is known to inhibit peripheral T-lymphocyte and thymocyte proliferation activated by antigens, mitogens or anti-CD3 antibodies. In this study, we have investigated, the effect of PGE2 on thymocyte proliferation induced by the combination of IL-4 plus PMA. PGE2 inhibits the proliferation of thymocytes activated by ConA, whatever the culture period; in contrast PGE2 shifts the kinetics of thymocyte proliferation after stimulation by IL-4 plus PMA, but does not sustain the proliferation beyond day 3. This effect depends upon cell density, IL-4 concentration and on the time that PGE2 is added to the culture. By use of the cAMP inducer, forskolin, or a cAMP analog, db-cAMP, we observed the same results, PGE2 increases the proliferation of CD8+ corticoresistant thymocytes (CRT) activated by IL-4 plus PMA, but inhibits that of CD4+ CRT. These results suggest that PGE2 can regulate thymocyte proliferation differently according to the activation pathway and the thymic subpopulations.

  11. A novel antagonist of the prostaglandin E(2) EP(4) receptor inhibits Th1 differentiation and Th17 expansion and is orally active in arthritis models.

    PubMed

    Chen, Q; Muramoto, K; Masaaki, N; Ding, Y; Yang, H; Mackey, M; Li, W; Inoue, Y; Ackermann, K; Shirota, H; Matsumoto, I; Spyvee, M; Schiller, S; Sumida, T; Gusovsky, F; Lamphier, M

    2010-05-01

    Rheumatoid arthritis (RA) is an autoimmune disorder involving subsets of activated T cells, in particular T helper (Th) 1 and Th17 cells, which infiltrate and damage tissues and induce inflammation. Prostaglandin E(2) (PGE(2)) enhances the Th17 response, exacerbates collagen-induced arthritis (CIA) and promotes inflammatory pain. The current study investigated whether selective antagonism of the PGE(2) EP(4) receptor would suppress Th1/Th17 cell development and inflammatory arthritis in animal models of RA. Effects of PGE(2) and a novel EP(4) receptor antagonist ER-819762 on Th1 differentiation, interleukin-23 (IL-23) production by dendritic cells (DCs), and Th17 development were assessed in vitro. The effect of ER-819762 was evaluated in CIA and glucose-6-phosphate isomerase (GPI)-induced arthritis models. In addition, the effects of ER-819762 on pain were evaluated in a model of chronic inflammatory pain induced by complete Freund's adjuvant (CFA) in the rat. Stimulation of the EP(4) receptor enhanced Th1 differentiation via phosphatidylinositol 3 kinase signalling, selectively promoted Th17 cell expansion, and induced IL-23 secretion by activated DCs, effects suppressed by ER-819762 or anti-PGE(2) antibody. Oral administration of ER-19762 suppressed Th1 and Th17 cytokine production, suppressed disease in collagen- and GPI-induced arthritis in mice, and suppressed CFA-induced inflammatory pain in rats. PGE(2) stimulates EP(4) receptors to promote Th1 differentiation and Th17 expansion and is critically involved in development of arthritis in two animal models. Selective suppression of EP(4) receptor signalling may have therapeutic value in RA both by modifying inflammatory arthritis and by relieving pain.

  12. Myeloid Cell Prostaglandin E2 Receptor EP4 Modulates Cytokine Production but Not Atherogenesis in a Mouse Model of Type 1 Diabetes.

    PubMed

    Vallerie, Sara N; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E; Breyer, Richard M; Andreasson, Katrin I; Bornfeldt, Karin E

    2016-01-01

    Type 1 diabetes mellitus (T1DM) is associated with cardiovascular complications induced by atherosclerosis. Prostaglandin E2 (PGE2) is often raised in states of inflammation, including diabetes, and regulates inflammatory processes. In myeloid cells, a key cell type in atherosclerosis, PGE2 acts predominately through its Prostaglandin E Receptor 4 (EP4; Ptger4) to modulate inflammation. The effect of PGE2-mediated EP4 signaling specifically in myeloid cells on atherosclerosis in the presence and absence of diabetes is unknown. Because diabetes promotes atherosclerosis through increased arterial myeloid cell accumulation, we generated a myeloid cell-targeted EP4-deficient mouse model (EP4M-/-) of T1DM-accelerated atherogenesis to investigate the relationship between myeloid cell EP4, inflammatory phenotypes of myeloid cells, and atherogenesis. Diabetic mice exhibited elevated plasma PGE metabolite levels and elevated Ptger4 mRNA in macrophages, as compared with non-diabetic littermates. PGE2 increased Il6, Il1b, Il23 and Ccr7 mRNA while reducing Tnfa mRNA through EP4 in isolated myeloid cells. Consistently, the stimulatory effect of diabetes on peritoneal macrophage Il6 was mediated by PGE2-EP4, while PGE2-EP4 suppressed the effect of diabetes on Tnfa in these cells. In addition, diabetes exerted effects independent of myeloid cell EP4, including a reduction in macrophage Ccr7 levels and increased early atherogenesis characterized by relative lesional macrophage accumulation. These studies suggest that this mouse model of T1DM is associated with increased myeloid cell PGE2-EP4 signaling, which is required for the stimulatory effect of diabetes on IL-6, markedly blunts the effect of diabetes on TNF-α and does not modulate diabetes-accelerated atherogenesis.

  13. Myeloid Cell Prostaglandin E2 Receptor EP4 Modulates Cytokine Production but Not Atherogenesis in a Mouse Model of Type 1 Diabetes

    PubMed Central

    Vallerie, Sara N.; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E.; Breyer, Richard M.; Andreasson, Katrin I.; Bornfeldt, Karin E.

    2016-01-01

    Type 1 diabetes mellitus (T1DM) is associated with cardiovascular complications induced by atherosclerosis. Prostaglandin E2 (PGE2) is often raised in states of inflammation, including diabetes, and regulates inflammatory processes. In myeloid cells, a key cell type in atherosclerosis, PGE2 acts predominately through its Prostaglandin E Receptor 4 (EP4; Ptger4) to modulate inflammation. The effect of PGE2-mediated EP4 signaling specifically in myeloid cells on atherosclerosis in the presence and absence of diabetes is unknown. Because diabetes promotes atherosclerosis through increased arterial myeloid cell accumulation, we generated a myeloid cell-targeted EP4-deficient mouse model (EP4M-/-) of T1DM-accelerated atherogenesis to investigate the relationship between myeloid cell EP4, inflammatory phenotypes of myeloid cells, and atherogenesis. Diabetic mice exhibited elevated plasma PGE metabolite levels and elevated Ptger4 mRNA in macrophages, as compared with non-diabetic littermates. PGE2 increased Il6, Il1b, Il23 and Ccr7 mRNA while reducing Tnfa mRNA through EP4 in isolated myeloid cells. Consistently, the stimulatory effect of diabetes on peritoneal macrophage Il6 was mediated by PGE2-EP4, while PGE2-EP4 suppressed the effect of diabetes on Tnfa in these cells. In addition, diabetes exerted effects independent of myeloid cell EP4, including a reduction in macrophage Ccr7 levels and increased early atherogenesis characterized by relative lesional macrophage accumulation. These studies suggest that this mouse model of T1DM is associated with increased myeloid cell PGE2-EP4 signaling, which is required for the stimulatory effect of diabetes on IL-6, markedly blunts the effect of diabetes on TNF-α and does not modulate diabetes-accelerated atherogenesis. PMID:27351842

  14. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  15. Regulation of PGE(2) and PGI(2) release from human umbilical vein endothelial cells by actin cytoskeleton

    NASA Technical Reports Server (NTRS)

    Sawyer, S. J.; Norvell, S. M.; Ponik, S. M.; Pavalko, F. M.

    2001-01-01

    Disruption of microfilaments in human umbilical vein endothelial cells (HUVEC) with cytochalasin D (cytD) or latrunculin A (latA) resulted in a 3.3- to 5.7-fold increase in total synthesis of prostaglandin E(2) (PGE(2)) and a 3.4- to 6.5-fold increase in prostacyclin (PGI(2)) compared with control cells. Disruption of the microtubule network with nocodazole or colchicine increased synthesis of PGE(2) 1.7- to 1.9-fold and PGI(2) 1.9- to 2.0-fold compared with control cells. Interestingly, however, increased release of PGE(2) and PGI(2) from HUVEC into the media occurred only when microfilaments were disrupted. CytD treatment resulted in 6.7-fold more PGE(2) and 3.8-fold more PGI(2) released from HUVEC compared with control cells; latA treatment resulted in 17.7-fold more PGE(2) and 11.2-fold more PGI(2) released compared with control cells. Both increased synthesis and release of prostaglandins in response to all drug treatments were completely inhibited by NS-398, a specific inhibitor of cyclooxygenase-2 (COX-2). Disruption of either microfilaments using cytD or latA or of microtubules using nocodazole or colchicine resulted in a significant increase in COX-2 protein levels, suggesting that the increased synthesis of prostaglandins in response to drug treatments may result from increased activity of COX-2. These results, together with studies demonstrating a vasoprotective role for prostaglandins, suggest that the cytoskeleton plays an important role in maintenance of endothelial barrier function by regulating prostaglandin synthesis and release from HUVEC.

  16. Aspirin provocation increases 8-iso-PGE2 in exhaled breath condensate of aspirin-hypersensitive asthmatics.

    PubMed

    Mastalerz, Lucyna; Januszek, Rafał; Kaszuba, Marek; Wójcik, Krzysztof; Celejewska-Wójcik, Natalia; Gielicz, Anna; Plutecka, Hanna; Oleś, Krzysztof; Stręk, Paweł; Sanak, Marek

    2015-09-01

    Isoprostanes are bioactive compounds formed by non-enzymatic oxidation of polyunsaturated fatty acids, mostly arachidonic, and markers of free radical generation during inflammation. In aspirin exacerbated respiratory disease (AERD), asthmatic symptoms are precipitated by ingestion of non-steroid anti-inflammatory drugs capable for pharmacologic inhibition of cyclooxygenase-1 isoenzyme. We investigated whether aspirin-provoked bronchoconstriction is accompanied by changes of isoprostanes in exhaled breath condensate (EBC). EBC was collected from 28 AERD subjects and 25 aspirin-tolerant asthmatics before and after inhalatory aspirin challenge. Concentrations of 8-iso-PGF2α, 8-iso-PGE2, and prostaglandin E2 were measured using gas chromatography/mass spectrometry. Leukotriene E4 was measured by immunoassay in urine samples collected before and after the challenge. Before the challenge, exhaled 8-iso-PGF2α, 8-iso-PGE2, and PGE2 levels did not differ between the study groups. 8-iso-PGE2 level increased in AERD group only (p=0.014) as a result of the aspirin challenge. Urinary LTE4 was elevated in AERD, both in baseline and post-challenge samples. Post-challenge airways 8-iso-PGE2 correlated positively with urinary LTE4 level (p=0.046), whereas it correlated negatively with the provocative dose of aspirin (p=0.027). A significant increase of exhaled 8-iso-PGE2 after inhalatory challenge with aspirin was selective and not present for the other isoprostane measured. This is a novel finding in AERD, suggesting that inhibition of cyclooxygenase may elicit 8-iso-PGE2 production in a specific mechanism, contributing to bronchoconstriction and systemic overproduction of cysteinyl leukotrienes. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. PGE2, Kidney Disease, and Cardiovascular Risk: Beyond Hypertension and Diabetes

    PubMed Central

    Nasrallah, Rania; Hassouneh, Ramzi

    2016-01-01

    An important measure of cardiovascular health is obtained by evaluating the global cardiovascular risk, which comprises a number of factors, including hypertension and type 2 diabetes, the leading causes of illness and death in the world, as well as the metabolic syndrome. Altered immunity, inflammation, and oxidative stress underlie many of the changes associated with cardiovascular disease, diabetes, and the metabolic syndrome, and recent efforts have begun to elucidate the contribution of PGE2 in these events. This review summarizes the role of PGE2 in kidney disease outcomes that accelerate cardiovascular disease, highlights the role of cyclooxygenase-2/microsomal PGE synthase 1/PGE2 signaling in hypertension and diabetes, and outlines the contribution of PGE2 to other aspects of the metabolic syndrome, particularly abdominal adiposity, dyslipidemia, and atherogenesis. A clearer understanding of the role of PGE2 could lead to new avenues to improve therapeutic options and disease management strategies. PMID:26319242

  18. Prostaglandin E2 induces chloride secretion through crosstalk between cAMP and calcium signaling in mouse inner medullary collecting duct cells

    PubMed Central

    Rajagopal, Madhumitha; Thomas, Sheela V.; Kathpalia, Paru P.; Chen, Yu

    2013-01-01

    Under conditions of high dietary salt intake, prostaglandin E2 (PGE2) production is increased in the collecting duct and promotes urinary sodium chloride (NaCl) excretion; however, the molecular mechanisms by which PGE2 increases NaCl excretion in this context have not been clearly defined. We used the mouse inner medullary collecting duct (mIMCD)-K2 cell line to characterize mechanisms underlying PGE2-regulated NaCl transport. When epithelial Na+ channels were inhibited, PGE2 exclusively stimulated basolateral EP4 receptors to increase short-circuit current (IscPGE2). We found that IscPGE2 was sensitive to inhibition by H-89 and CFTR-172, indicating that EP4 receptors signal through protein kinase A to induce Cl− secretion via cystic fibrosis transmembrane conductance regulator (CFTR). Unexpectedly, we also found that IscPGE2 was sensitive to inhibition by BAPTA-AM (Ca2+ chelator), 2-aminoethoxydiphenyl borate (2-APB) (inositol triphosphate receptor blocker), and flufenamic acid (FFA) [Ca2+-activated Cl− channel (CACC) inhibitor], suggesting that EP4 receptors also signal through Ca2+ to induce Cl− secretion via CACC. Additionally, we observed that PGE2 stimulated an increase in Isc through crosstalk between cAMP and Ca2+ signaling; BAPTA-AM or 2-APB inhibited a component of IscPGE2 that was sensitive to CFTR-172 inhibition; H-89 inhibited a component of IscPGE2 that was sensitive to FFA inhibition. Together, our findings indicate that PGE2 activates basolateral EP4 receptors and signals through both cAMP and Ca2+ to stimulate Cl− secretion in IMCD-K2 cells. We propose that these signaling pathways, and the crosstalk between them, may provide a concerted mechanism for enhancing urinary NaCl excretion under conditions of high dietary NaCl intake. PMID:24284792

  19. Dectin-1/2–induced autocrine PGE2 signaling licenses dendritic cells to prime Th2 responses

    PubMed Central

    Kaisar, Maria M. M.; Jónasdóttir, Hulda S.; van der Ham, Alwin J.; Pelgrom, Leonard R.; Schramm, Gabriele; Layland, Laura E.; Sancho, David; Prazeres da Costa, Clarissa; Giera, Martin; Yazdanbakhsh, Maria

    2018-01-01

    The molecular mechanisms through which dendritic cells (DCs) prime T helper 2 (Th2) responses, including those elicited by parasitic helminths, remain incompletely understood. Here, we report that soluble egg antigen (SEA) from Schistosoma mansoni, which is well known to drive potent Th2 responses, triggers DCs to produce prostaglandin E2 (PGE2), which subsequently—in an autocrine manner—induces OX40 ligand (OX40L) expression to license these DCs to drive Th2 responses. Mechanistically, SEA was found to promote PGE2 synthesis through Dectin-1 and Dectin-2, and via a downstream signaling cascade involving spleen tyrosine kinase (Syk), extracellular signal-regulated kinase (ERK), cytosolic phospholipase A2 (cPLA2), and cyclooxygenase 1 and 2 (COX-1 and COX-2). In addition, this pathway was activated independently of the actions of omega-1 (ω-1), a previously described Th2-priming glycoprotein present in SEA. These findings were supported by in vivo murine data showing that ω-1–independent Th2 priming by SEA was mediated by Dectin-2 and Syk signaling in DCs. Finally, we found that Dectin-2−/−, and to a lesser extent Dectin-1−/− mice, displayed impaired Th2 responses and reduced egg-driven granuloma formation following S. mansoni infection, highlighting the physiological importance of this pathway in Th2 polarization during a helminth infection. In summary, we identified a novel pathway in DCs involving Dectin-1/2-Syk-PGE2-OX40L through which Th2 immune responses are induced. PMID:29668708

  20. Direct growth-inhibitory effects of prostaglandin E2 in pancreatic cancer cells in vitro through an EP4/PKA-mediated mechanism.

    PubMed

    Schmidt, Andrea; Sinnett-Smith, James; Young, Steven; Chang, Hui-Hua; Hines, O Joe; Dawson, David W; Rozengurt, Enrique; Eibl, Guido

    2017-06-01

    There is strong evidence linking inflammation and the development of pancreatic ductal adenocarcinoma. Cyclooxygenase-2 (COX-2) and COX-2-derived PGE 2 are overexpressed in human and murine pancreatic ductal adenocarcinoma. Several studies have demonstrated an important role of COX-2-derived PGE 2 in tumor-stroma interactions; however, the direct growth effects of prostaglandin E 2 (PGE 2 ) on pancreatic ductal adenocarcinoma cells is less well defined. Our aim was to investigate the effects of PGE 2 on pancreatic ductal adenocarcinoma cell growth and to characterize the underlying mechanisms. Human pancreatic ductal adenocarcinoma cell lines, Panc-1 and MIA PaCa-2, were treated with PGE 2 in varying doses (0-10 μM). Effects on the phosphorylation of ERK1/2 were evaluated by Western blot. Colony formation was observed for cells treated with PGE 2 for 11 days. DNA synthesis was determined by (3H)-thymidine incorporation assay. Gene expression of E-type prostaglandin (EP)2/EP4 receptors and their correlation with survival in patients with pancreatic ductal adenocarcinoma were assessed using the RNA-Seq data set from The Cancer Genome Atlas Research Network. PGE 2 decreased the size and number of colonies in Panc-1 but not MIA PaCa-2 cells. In the Panc-1 cells, PGE 2 activated PKA/CREB and decreased phosphorylation of ERK1/2, which was reversed by an EP4 receptor antagonist, while an EP2 receptor antagonist had no effect. In contrast, in MIA PaCa-2 cells, PGE 2 had no effect on ERK1/2 phosphorylation. Treatment of both Panc-1 and MIA PaCa-2 cells with forskolin/IBMX decreased ERK1/2 phosphorylation. Finally, PGE 2 decreased DNA synthesis only in Panc-1 cells, which was reversed by an EP4 receptor antagonist. In human pancreatic ductal adenocarcinoma, high EP2 and low EP4 gene expression was correlated to worse median overall survival (15.6 vs 20.8 months, log-rank P = .017). Our study provides evidence that PGE 2 can inhibit directly pancreatic ductal

  1. PGE2 receptor EP3 inhibits water reabsorption and contributes to polyuria and kidney injury in a streptozotocin-induced mouse model of diabetes.

    PubMed

    Hassouneh, Ramzi; Nasrallah, Rania; Zimpelmann, Joe; Gutsol, Alex; Eckert, David; Ghossein, Jamie; Burns, Kevin D; Hébert, Richard L

    2016-06-01

    The first clinical manifestation of diabetes is polyuria. The prostaglandin E2 (PGE2) receptor EP3 antagonises arginine vasopressin (AVP)-mediated water reabsorption and its expression is increased in the diabetic kidney. The purpose of this work was to study the contribution of EP3 to diabetic polyuria and renal injury. Male Ep 3 (-/-) (also known as Ptger3 (-/-)) mice were treated with streptozotocin (STZ) to generate a mouse model of diabetes and renal function was evaluated after 12 weeks. Isolated collecting ducts (CDs) were microperfused to study the contribution of EP3 to AVP-mediated fluid reabsorption. Ep 3 (-/-)-STZ mice exhibited attenuated polyuria and increased urine osmolality compared with wild-type STZ (WT-STZ) mice, suggesting enhanced water reabsorption. Compared with WT-STZ mice, Ep 3 (-/-)-STZ mice also had increased protein expression of aquaporin-1, aquaporin-2, and urea transporter A1, and reduced urinary AVP excretion, but increased medullary V2 receptors. In vitro microperfusion studies indicated that Ep 3 (-/-) and WT-STZ CDs responded to AVP stimulation similarly to those of wild-type mice, with a 60% increase in fluid reabsorption. In WT non-injected and WT-STZ mice, EP3 activation with sulprostone (PGE2 analogue) abrogated AVP-mediated water reabsorption; this effect was absent in mice lacking EP3. A major finding of this work is that Ep 3 (-/-)-STZ mice showed blunted renal cyclooxygenase-2 protein expression, reduced renal hypertrophy, reduced hyperfiltration and reduced albuminuria, as well as diminished tubular dilation and nuclear cysts. Taken together, the data suggest that EP3 contributes to diabetic polyuria by inhibiting expression of aquaporins and that it promotes renal injury during diabetes. EP3 may prove to be a promising target for more selective management of diabetic kidney disease.

  2. PG&E WaveConnect Program Final Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brendan P. Dooher; Edward Cheslak; Robert Booth

    and from different device manufacturers could be tested. PG&E was to provide permitting, subsea cables, and on-shore facilities necessary to connect WaveConnect to an existing PG&E substation, while the WEC manufacturers would provide, operate and maintain their devices during the test period. Technology and Commercial Readiness: PG&E issued a Request for Information to the wave power industry to assess the technical and commercial capabilities of WEC manufacturers. Sixteen manufacturers responded, representing the four best-known and most mature designs. PG&E found that WECs are early-stage devices with evolving designs and little real-world operating experience. These characteristics made environmental impacts difficult to assess, which complicated permitting efforts. It also made a megawatt-scale demonstration project difficult to support because early stage WECs are costly and have limited track records for performance and reliability. Results: PG&E withdrew its FERC DPLA for HWC in November 2010 and surrendered its preliminary permit for CCWC in May 2011, effectively discontinuing the project for the following combination of reasons: Permitting issues were much more challenging than originally anticipated. Stage One project funding of $6 million proved insufficient to complete the necessary development and permitting work. During Stage One development, PG&E determined that permitting costs would be $2 million to $5 million greater than originally budgeted. The cost of developing a five-year, 5-MW pilot project at Humboldt Bay is much greater than the $15 million to $20 million originally estimated. Even assuming that vendors provide WEC devices at no cost to the utility, which was the proposed strategy with WaveConnect, PG&E concluded that a pilot project comparable to HWC would cost approximately $47 million. If WEC devices were purchased for such a project, its total cost would be on the order of $90 million. It is unclear when or if wave power will become

  3. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dimov, V.; Green, K.; Bygdeman, M.

    1983-02-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2.

  4. Dipyrone metabolite 4-MAA induces hypothermia and inhibits PGE2-dependent and -independent fever while 4-AA only blocks PGE2-dependent fever

    PubMed Central

    Malvar, David do C; Aguiar, Fernando A; Vaz, Artur de L L; Assis, Débora C R; de Melo, Miriam C C; Jabor, Valquíria A P; Kalapothakis, Evanguedes; Ferreira, Sérgio H; Clososki, Giuliano C; de Souza, Glória E P

    2014-01-01

    BACKGROUND AND PURPOSE The antipyretic and hypothermic prodrug dipyrone prevents PGE2-dependent and -independent fever induced by LPS from Escherichia coli and Tityus serrulatus venom (Tsv) respectively. We aimed to identify the dipyrone metabolites responsible for the antipyretic and hypothermic effects. EXPERIMENTAL APPROACH Male Wistar rats were treated i.p. with indomethacin (2 mg·kg−1), dipyrone, 4-methylaminoantipyrine (4-MAA), 4-aminoantipyrine (4-AA) (60–360 mg·kg−1), 4-formylaminoantipyrine, 4-acethylaminoantipyrine (120–360 mg·kg−1) or vehicle 30 min before i.p. injection of LPS (50 μg·kg−1), Tsv (150 μg·kg−1) or saline. Rectal temperatures were measured by tele-thermometry and dipyrone metabolite concentrations determined in the plasma, CSF and hypothalamus by LC-MS/MS. PGE2 concentrations were determined in the CSF and hypothalamus by elisa. KEY RESULTS In contrast to LPS, Tsv-induced fever was not followed by increased PGE2 in the CSF or hypothalamus. The antipyretic time-course of 4-MAA and 4-AA on LPS-induced fever overlapped with the period of the highest concentrations of 4-MAA and 4-AA in the hypothalamus, CSF and plasma. These metabolites reduced LPS-induced fever and the PGE2 increase in the plasma, CSF and hypothalamus. Only 4-MAA inhibited Tsv-induced fever. The higher doses of dipyrone and 4-MAA also induced hypothermia. CONCLUSIONS AND IMPLICATIONS The presence of 4-MAA and 4-AA in the CSF and hypothalamus was associated with PGE2 synthesis inhibition and a decrease in LPS-induced fever. 4-MAA was also shown to be an antipyretic metabolite for PGE2-independent fever induced by Tsv suggesting that it is responsible for the additional antipyretic mechanism of dipyrone. Moreover, 4-MAA is the hypothermic metabolite of dipyrone. PMID:24712707

  5. Dipyrone metabolite 4-MAA induces hypothermia and inhibits PGE2 -dependent and -independent fever while 4-AA only blocks PGE2 -dependent fever.

    PubMed

    Malvar, David do C; Aguiar, Fernando A; Vaz, Artur de L L; Assis, Débora C R; de Melo, Miriam C C; Jabor, Valquíria A P; Kalapothakis, Evanguedes; Ferreira, Sérgio H; Clososki, Giuliano C; de Souza, Glória E P

    2014-08-01

    The antipyretic and hypothermic prodrug dipyrone prevents PGE2 -dependent and -independent fever induced by LPS from Escherichia coli and Tityus serrulatus venom (Tsv) respectively. We aimed to identify the dipyrone metabolites responsible for the antipyretic and hypothermic effects. Male Wistar rats were treated i.p. with indomethacin (2 mg·kg(-1) ), dipyrone, 4-methylaminoantipyrine (4-MAA), 4-aminoantipyrine (4-AA) (60-360 mg·kg(-1) ), 4-formylaminoantipyrine, 4-acethylaminoantipyrine (120-360 mg·kg(-1) ) or vehicle 30 min before i.p. injection of LPS (50 μg·kg(-1) ), Tsv (150 μg·kg(-1) ) or saline. Rectal temperatures were measured by tele-thermometry and dipyrone metabolite concentrations determined in the plasma, CSF and hypothalamus by LC-MS/MS. PGE2 concentrations were determined in the CSF and hypothalamus by elisa. In contrast to LPS, Tsv-induced fever was not followed by increased PGE2 in the CSF or hypothalamus. The antipyretic time-course of 4-MAA and 4-AA on LPS-induced fever overlapped with the period of the highest concentrations of 4-MAA and 4-AA in the hypothalamus, CSF and plasma. These metabolites reduced LPS-induced fever and the PGE2 increase in the plasma, CSF and hypothalamus. Only 4-MAA inhibited Tsv-induced fever. The higher doses of dipyrone and 4-MAA also induced hypothermia. The presence of 4-MAA and 4-AA in the CSF and hypothalamus was associated with PGE2 synthesis inhibition and a decrease in LPS-induced fever. 4-MAA was also shown to be an antipyretic metabolite for PGE2 -independent fever induced by Tsv suggesting that it is responsible for the additional antipyretic mechanism of dipyrone. Moreover, 4-MAA is the hypothermic metabolite of dipyrone. © 2014 The British Pharmacological Society.

  6. Selective inhibition of prostaglandin E2 receptors EP2 and EP4 inhibits adhesion of human endometriotic epithelial and stromal cells through suppression of integrin-mediated mechanisms.

    PubMed

    Lee, JeHoon; Banu, Sakhila K; Burghardt, Robert C; Starzinski-Powitz, Anna; Arosh, Joe A

    2013-03-01

    Endometriosis is a chronic gynecological disease of reproductive age women characterized by the presence of functional endometrial tissues outside the uterine cavity. Interactions between the endometriotic cells and the peritoneal extracellular matrix proteins (ECM) are crucial mechanisms that allow adhesion of the endometriotic cells into peritoneal mesothelia. Prostaglandin E2 (PGE2) plays an important role in the pathogenesis of endometriosis. In previous studies, we have reported that selective inhibition of PGE2 receptors PTGER2 and PTGER4 decreases survival and invasion of human endometriotic epithelial and stromal cells through multiple mechanisms. Results of the present study indicates that selective inhibition of PTGER2- and PTGER4-mediated PGE2 signaling 1) decreases the expression and/or activity of specific integrin receptor subunits Itgb1 (beta1) and Itgb3 (beta3) but not Itgb5 (beta5), Itga1 (alpha1), Itga2 (alpha2), Itga5 (alpha5), and Itgav (alphav); 2) decreases integrin-signaling components focal adhesion kinase or protein kinase 2 (PTK2) and talin proteins; 3) inhibits interactions between Itgb1/Itgb3 subunits, PTK2, and talin and PTGER2/PTGER4 proteins through beta-arrestin-1 and Src kinase protein complex in human endometriotic epithelial cells 12Z and stromal cells 22B; and 4) decreases adhesion of 12Z and 22B cells to ECM collagen I, collagen IV, fibronectin, and vitronectin in a substrate-specific manner. These novel findings provide an important molecular framework for further evaluation of selective inhibition of PTGER2 and PTGER4 as potential nonsteroidal therapy to expand the spectrum of currently available treatment options for endometriosis in child-bearing age women.

  7. Prostaglandin E2 is essential for efficacious skeletal muscle stem-cell function, augmenting regeneration and strength.

    PubMed

    Ho, Andrew T V; Palla, Adelaida R; Blake, Matthew R; Yucel, Nora D; Wang, Yu Xin; Magnusson, Klas E G; Holbrook, Colin A; Kraft, Peggy E; Delp, Scott L; Blau, Helen M

    2017-06-27

    Skeletal muscles harbor quiescent muscle-specific stem cells (MuSCs) capable of tissue regeneration throughout life. Muscle injury precipitates a complex inflammatory response in which a multiplicity of cell types, cytokines, and growth factors participate. Here we show that Prostaglandin E2 (PGE2) is an inflammatory cytokine that directly targets MuSCs via the EP4 receptor, leading to MuSC expansion. An acute treatment with PGE2 suffices to robustly augment muscle regeneration by either endogenous or transplanted MuSCs. Loss of PGE2 signaling by specific genetic ablation of the EP4 receptor in MuSCs impairs regeneration, leading to decreased muscle force. Inhibition of PGE2 production through nonsteroidal anti-inflammatory drug (NSAID) administration just after injury similarly hinders regeneration and compromises muscle strength. Mechanistically, the PGE2 EP4 interaction causes MuSC expansion by triggering a cAMP/phosphoCREB pathway that activates the proliferation-inducing transcription factor, Nurr1 Our findings reveal that loss of PGE2 signaling to MuSCs during recovery from injury impedes muscle repair and strength. Through such gain- or loss-of-function experiments, we found that PGE2 signaling acts as a rheostat for muscle stem-cell function. Decreased PGE2 signaling due to NSAIDs or increased PGE2 due to exogenous delivery dictates MuSC function, which determines the outcome of regeneration. The markedly enhanced and accelerated repair of damaged muscles following intramuscular delivery of PGE2 suggests a previously unrecognized indication for this therapeutic agent.

  8. Regional expression of prostaglandin E2 and F2alpha receptors in human myometrium, amnion, and choriodecidua with advancing gestation and labor.

    PubMed

    Grigsby, Peta L; Sooranna, Suren R; Adu-Amankwa, Bernice; Pitzer, Brad; Brockman, Diane E; Johnson, Mark R; Myatt, Leslie

    2006-08-01

    The change from uterine quiescence to enhanced contractile activity may be due to the differential expression of prostaglandin receptors within the myometrium and fetal membranes, in a temporal and topographically distinct manner. To address this question, we determined the localization and expression of the PGE2 receptor subtypes (PTGER1-4) and the PGF2alpha receptor (PTGFR) in paired upper and lower segment myometrium, amnion, and choriodecidual samples throughout human pregnancy, with and without labor. All receptor subtypes were found throughout the muscle layers in both the upper and lower uterine segments, colocalizing with alpha smooth muscle actin. A change in intracellular localization was observed at term labor, where PTGER1 and PTGER4 were predominately associated with the nucleus. Minimal changes in the expression of the PGE2 and PGF2alpha receptor subtypes were observed with gestational age, labor, or between the upper and lower myometrial segments. Receptor expression in maternal and fetal tissues differed between the receptor subtypes; PTGER1 and PTGER4 were predominately expressed in the fetal membranes, PTGER2 was greatest in the myometrium, whereas PTGER3 and PTGFR were similarly expressed in the myometrium and fetal membranes. Myometrial activation through the prostaglandin receptors is perhaps more subtle and may be mediated by a balance between one or several of the prostaglandin receptor subtypes together with other known contraction associated proteins. Lack of coordination in receptor expression between the myometrium and fetal membranes may indicate different regulatory mechanisms between these tissues, or it may suggest a function for these receptors in the amnion and choriodecidua that is independent of that seen in the myometrium.

  9. Pirfenidone attenuates IL-1β-induced COX-2 and PGE2 production in orbital fibroblasts through suppression of NF-κB activity.

    PubMed

    Choi, Youn-Hee; Back, Keum Ok; Kim, Hee Ja; Lee, Sang Yeul; Kook, Koung Hoon

    2013-08-01

    The aim of this study was to determine the effect of pirfenidone on interleukin (IL)-1β-induced cyclooxygenase (COX)-2 and prostaglandin (PG)E2 expression in orbital fibroblasts from patients with thyroid-associated ophthalmopathy (TAO). Primary cultures of orbital fibroblasts from patients with TAO (n = 4) and non-TAO subjects (n = 4) were prepared. The level of PGE2 in orbital fibroblasts treated with IL-1β in the presence or absence of pirfenidone was measured using an enzyme-linked immunosorbent assay. The effect of pirfenidone on IL-1β-induced COX-2 expression in orbital fibroblasts from patients with TAO was evaluated by reverse transcription-polymerase chain reaction (PCR) and quantitative real-time PCR analyses, and verified by Western blot. Activation of nuclear factor-κB (NF-κB) was evaluated by immunoblotting for inhibitor of κB (IκB)α and phosphorylated IκBα, and DNA-binding activity of p50/p65 NF-κB was analyzed by electrophoretic mobility shift assay. In addition, IL-1 receptor type 1 (IL-1R1) expression was assessed by RT-PCR in IL-1β-treated cells with or without pirfenidone. Pirfenidone significantly attenuated IL-1β-induced PGE2 release in both TAO and non-TAO cells. IL-1β-induced COX-2 mRNA and protein expression decreased significantly following co-treatment with pirfenidone. IL-1β-induced IκBα phosphorylation and degradation decreased in the presence of pirfenidone and led to decreased nuclear translocation and DNA binding of the active NF-κB complex. In our system, neither IL-1β nor pirfenidone co-treatment influenced IL-1R1 expression. Our results suggest that pirfenidone attenuates the IL-1β-induced PGE2/COX-2 production in TAO orbital fibroblasts, which is related with suppression of the NF-κB activation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Norepinephrine enhances the LPS-induced expression of COX-2 and secretion of PGE2 in primary rat microglia

    PubMed Central

    2010-01-01

    Background Recent studies suggest an important role for neurotransmitters as modulators of inflammation. Neuroinflammatory mediators such as cytokines and molecules of the arachidonic acid pathway are generated and released by microglia. The monoamine norepinephrine reduces the production of cytokines by activated microglia in vitro. However, little is known about the effects of norepinephrine on prostanoid synthesis. In the present study, we investigate the role of norepinephrine on cyclooxygenase- (COX-)2 expression/synthesis and prostaglandin (PG)E2 production in rat primary microglia. Results Interestingly, norepinephrine increased COX-2 mRNA, but not protein expression. Norepinephrine strongly enhanced COX-2 expression and PGE2 production induced by lipopolysaccharide (LPS). This effect is likely to be mediated by β-adrenoreceptors, since β-, but not α-adrenoreceptor agonists produced similar results. Furthermore, β-adrenoreceptor antagonists blocked the enhancement of COX-2 levels induced by norepinephrine and β-adrenoreceptor agonists. Conclusions Considering that PGE2 displays different roles in neuroinflammatory and neurodegenerative disorders, norepinephrine may play an important function in the modulation of these processes in pathophysiological conditions. PMID:20064241

  11. Targeted prostaglandin E2 inhibition enhances antiviral immunity through induction of type I interferon and apoptosis in macrophages.

    PubMed

    Coulombe, François; Jaworska, Joanna; Verway, Mark; Tzelepis, Fanny; Massoud, Amir; Gillard, Joshua; Wong, Gary; Kobinger, Gary; Xing, Zhou; Couture, Christian; Joubert, Philippe; Fritz, Jörg H; Powell, William S; Divangahi, Maziar

    2014-04-17

    Aspirin gained tremendous popularity during the 1918 Spanish Influenza virus pandemic, 50 years prior to the demonstration of their inhibitory action on prostaglandins. Here, we show that during influenza A virus (IAV) infection, prostaglandin E2 (PGE2) was upregulated, which led to the inhibition of type I interferon (IFN) production and apoptosis in macrophages, thereby causing an increase in virus replication. This inhibitory role of PGE2 was not limited to innate immunity, because both antigen presentation and T cell mediated immunity were also suppressed. Targeted PGE2 suppression via genetic ablation of microsomal prostaglandin E-synthase 1 (mPGES-1) or by the pharmacological inhibition of PGE2 receptors EP2 and EP4 substantially improved survival against lethal IAV infection whereas PGE2 administration reversed this phenotype. These data demonstrate that the mPGES-1-PGE2 pathway is targeted by IAV to evade host type I IFN-dependent antiviral immunity. We propose that specific inhibition of PGE2 signaling might serve as a treatment for IAV. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Up-regulation of cyclooxygenase-2 by product-prostaglandin E2

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Hughes-Fulford, M.

    1997-01-01

    The development of prostate cancer has been linked to high level of dietary fat intake. Our laboratory investigates the connection between cancer cell growth and fatty acid products. Studying human prostatic carcinoma PC-3 cells, we found that prostaglandin E2 (PGE2) increased cell growth and up-regulated the gene expression of its own synthesizing enzyme, cyclooxygenase-2 (COX-2). PGE2 increased COX-2 mRNA expression dose-dependently with the highest levels of stimulation seen at the 3-hour period following PGE2 addition. The NSAID flurbiprofen (5 microM), in the presence of exogenous PGE2, inhibited the up-regulation of COX-2 mRNA and cell growth. These data suggest that the levels of local intracellular PGE2 play a major role in the growth of prostate cancer cells through an activation of COX-2 gene expression.

  13. Netrin-1 regulates the inflammatory response of neutrophils and macrophages, and suppresses ischemic acute kidney injury by inhibiting COX-2 mediated PGE2 production

    PubMed Central

    Ranganathan, Punithavathi Vilapakkam; Jayakumar, Calpurnia; Mohamed, Riyaz; Dong, Zheng; Ramesh, Ganesan

    2012-01-01

    Netrin-1 regulates inflammation but the mechanism by which this occurs is unknown. Here we explore the role of netrin-1 in regulating the production of the prostanoid metabolite PGE2 from neutrophils in in vitro and in vivo disease models. Ischemia reperfusion in wild-type and RAG-1 knockout mice induced severe kidney injury that was associated with a large increase in neutrophil infiltration and COX-2 expression in the infiltrating leukocytes. Administration of netrin-1 suppressed COX-2 expression, PGE2 and thromboxane production, and neutrophil infiltration into the kidney. This was associated with reduced apoptosis, inflammatory cytokine and chemokine expression, and improved kidney function. Treatment with the PGE2 receptor EP4 agonist enhanced neutrophil infiltration and renal injury which was not inhibited by netrin-1. Consistent with in vivo data, both LPS and IFNγ-induced inflammatory cytokine production in macrophages and IL-17-induced IFNγ production in neutrophils were suppressed by netrin-1 in vitro by suppression of COX-2 expression. Moreover, netrin-1 regulates COX-2 expression at the transcriptional level through the regulation of NFκB activation. Thus, netrin-1 regulates the inflammatory response of neutrophils and macrophages through suppression of COX-2 mediated PGE2 production. This could be a potential drug for treating many inflammatory immune disorders. PMID:23447066

  14. Osteoblast Differentiation Decreases Hypergravity-Stimulated Release of PGE(sub 2)

    NASA Technical Reports Server (NTRS)

    Searby, Nancy D.; Steele, Charles R.; Globus, Ruth K.

    2002-01-01

    We determined if progressive differentiation of osteoblasts influences their sensitivity to gravitational loading. Osteoblasts were cultured for 4 days (confluent monolayer), 6 days (prenodules), 9 days (nodules) and 19 days (mineralized nodules), then centrifuged at 10 times gravity (g) or 50-g for 3 hours using the NASA Ames 1-ft. Diameter Centrifuge. Stationary controls were placed in an adjacent incubator. Following centrifugation, conditioned media were collected and analyzed for PGE, by ELISA. Microtubules were fluorescently labeled and analyzed by confocal microscopy to determine microtubule network morphology and height. Centrifugation at 10-g reduced microtubule network height by 15% on d4 and 10% on d6, with variable changes in more mature cultures. No major changes in microtubule morphology were observed. PGE(sub 2) release by d4 cultures increased in a dose-dependent fashion (3-fold at 10-g and 6-fold at 50-g relative to controls). D6 cultures produced a 5-fold increase for both 10-g and 50-g. PGE(sub 2) increased only 1.5-fold by d9, and by d19, PGE(sub 2) was not delectable in either the control or hypergravity-stimulated cells. Thus, as osteoblasts differentiate in culture, responsiveness of the microtubule cytoskeleton and the PGE(sub 2) pathway to hypergravity declines.

  15. Nitrooleic acid protects against cisplatin nephropathy: role of COX-2/mPGES-1/PGE2 cascade.

    PubMed

    Wang, Haiping; Jia, Zhanjun; Sun, Jing; Xu, Liang; Zhao, Bing; Yu, Kezhou; Yang, Meng; Yang, Tianxin; Wang, Rong

    2015-01-01

    Nitrooleic acid (OA-NO2) is an endogenous lipid product which has novel signaling properties, particularly the activation of peroxisome proliferator-activated receptors. The current study aimed to evaluate the protective effects of OA-NO2 against cisplatin-induced kidney injury in mice. Mice were pretreated with OA-NO2 for 48 h before cisplatin administration, and the cisplatin-caused nephrotoxicity was evaluated. After the cisplatin treatment (72 h), the vehicle-treated mice displayed renal dysfunction, as evidenced by the elevated plasma urea and creatinine, which was consistent with the histological damage, such as tubular necrosis, dilation, protein cast, and desquamation of epithelial cells. In contrast, the severity of the renal dysfunction and histological change were reduced in the OA-NO2 pretreated mice. The renal COX-2 and mPGES-1 mRNAs and their respective proteins expression, together with the renal PGE2 amounts, were induced by the cisplatin treatment, but their initiation was reduced by OA-NO2. Moreover, the circulating TNF-α, renal TNF-α, IL-1β, MCP-1, ICAM-1, and VACAM-1 mRNA levels were higher in the cisplatin-treated mice, compared with the controls, but they were attenuated in the OA-NO2 pretreatment group. In summary, the pretreatment with OA-NO2 remarkably ameliorated the cisplatin-induced kidney injury in mice, possibly via the inhibition of the inflammatory response, associated with the COX-2/mPGES-1/PGE2 cascade.

  16. CYP2S1 depletion enhances colorectal cell proliferation is associated with PGE2-mediated activation of β-catenin signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Chao; College of Life Science, Anhui Normal University, Wuhu 241000, Anhui; Li, Changyuan

    2015-02-15

    Colorectal epithelial cancer is one of the most common cancers in the world and its 5-year survival rate is still relatively low. Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in the oxidative metabolism of a wide range of xenobiotics, including (pro-)carcinogens and endogenous compounds. Although CYP2S1, a member of CYP family, strongly expressed in many extrahepatic tissues, the role of CYP2S1 in cancer remains unclear. To investigate whether CYP2S1 involves in colorectal carcinogenesis, cell proliferation was analyzed in HCT116 cells depleted of CYP2S1 using small hairpin interfering RNA. Our data show thatmore » CYP2S1 knockdown promotes cell proliferation through increasing the level of endogenous prostaglandin E2(PGE2). PGE2, in turn, reduces phosphorylation of β-catenin and activates β-catenin signaling, which contributes to the cell proliferation. Furthermore, CYP2S1 knockdown increase tumor growth in xenograft mouse model. In brief, these results demonstrate that CYP2S1 regulates colorectal cancer growth through associated with PGE2-mediated activation of β-catenin signaling. - Highlights: • Knockdown of CYP2S1 expression improve HCT116 cell proliferation in vitro and in vivo. • Elevate PGE2 production in CYP2S1 knockdown cell is associated with its proliferation. • Elevate PGE2 level in CYP2S1 knockdown cells enhance β-catenin accumulation. • β-catenin activate TCF/LEF and target gene expression thus promote cell proliferation.« less

  17. Prostaglandin E(2) mediates acid-induced heartburn in healthy volunteers.

    PubMed

    Kondo, Takashi; Oshima, Tadayuki; Tomita, Toshihiko; Fukui, Hirokazu; Watari, Jiro; Okada, Hiroki; Kikuchi, Shojiro; Sasako, Mitsuru; Matsumoto, Takayuki; Knowles, Charles H; Miwa, Hiroto

    2013-03-15

    Prostaglandin E(2) (PGE(2)) plays a major role in pain processing and hypersensitivity. This study investigated whether PGE(2) levels are increased in the esophageal mucosa after acid infusion and whether increases in PGE(2) are associated with heartburn. Furthermore, expression of the PGE(2) receptor EP1 was investigated in human esophageal mucosa. Fourteen healthy male volunteers were randomized to 30-min lower esophageal acid (1% HCl) or saline perfusion. Before and after acid perfusion, endoscopic biopsies were taken from the distal esophagus. PGE(2) concentration (pg/mg protein) and EP1 mRNA and protein in biopsy samples were measured by ELISA, RT-PCR, and Western blotting. Symptom status of heartburn was evaluated with a validated categorical rating scale with a higher values corresponding to increasing intensity. PGE(2) levels in the esophageal mucosa significantly increased after acid infusion (before vs. after acid infusion: 23.2 ± 8.6 vs. 68.6 ± 18.3, P < 0.05), but not after saline infusion (before vs. after saline infusion: 9.3 ± 2.5 vs. 9.0 ± 3.2, NS). Time to first sensation (min) after acid infusion was less than after saline (saline vs. acid infusion: 22.1 ± 4.1 vs. 5.4 ± 1.5, P < 0.05). Intensity of heartburn in the acid-infusion group was also significantly greater compared with saline (saline vs. acid infusion: 54.3 ± 13.1 vs. 178.5 ± 22.8, P < 0.01). Changes in PGE(2) levels in the esophagus correlated with symptom intensity score (r = 0.80, P = 0.029). EP1 mRNA and protein expression were observed in the normal human esophageal mucosa. Esophageal PGE(2) expression is associated with mucosal acid exposure and heartburn.

  18. COX-2/PGE2: molecular ambassadors of Kaposi's sarcoma-associated herpes virus oncoprotein-v-FLIP

    PubMed Central

    Sharma-Walia, N; Patel, K; Chandran, K; Marginean, A; Bottero, V; Kerur, N; Paul, A G

    2012-01-01

    Kaposi's sarcoma herpesvirus (KSHV) latent oncoprotein viral FLICE (FADD-like interferon converting enzyme)-like inhibitory protein (v-FLIP) or K13, a potent activator of NF-κB, has well-established roles in KSHV latency and oncogenesis. KSHV-induced COX-2 represents a novel strategy employed by KSHV to promote latency and inflammation/angiogenesis/invasion. Here, we demonstrate that v-FLIP/K13 promotes tumorigenic effects via the induction of host protein COX-2 and its inflammatory metabolite PGE2 in an NF-κB-dependent manner. In addition to our previous studies demonstrating COX-2/PGE2's role in transcriptional regulation of KSHV latency promoter and latent gene expression, the current study adds to the complexity that though LANA-1 (latency associated nuclear antigen) is utilizing COX-2/PGE2 as critical factors for its transcriptional regulation, it is the v-FLIP/K13 gene in the KSHV latency cluster that maintains continuous COX-2/PGE2 levels in the infected cells. We demonstrate that COX-2 inhibition, via its chemical inhibitors (NS-398 or celecoxib), reduced v-FLIP/K13-mediated NF-κB induction, and extracellular matrix (ECM) interaction-mediated signaling, mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) levels, and subsequently downregulated detachment-induced apoptosis (anoikis) resistance. vFLIP expression mediated the secretion of cytokines, and spindle cell differentiation activated the phosphorylation of p38, RSK, FAK, Src, Akt and Rac1-GTPase. The COX-2 inhibition in v-FLIP/K13-HMVECs reduced inflammation and invasion/metastasis-related genes, along with reduced anchorage-independent colony formation via modulating ‘extrinsic' as well as ‘intrinsic' cell death pathways. COX-2 blockade in v-FLIP/K13-HMVEC cells drastically augmented cell death induced by removal of essential growth/survival factors secreted in the microenvironment. Transformed cells obtained from anchorage-independent colonies of COX-2 inhibitor-treated v

  19. Tumor-secreted PGE2 inhibits CCL5 production in activated macrophages through cAMP/PKA signaling pathway.

    PubMed

    Qian, Xuesong; Zhang, Jidong; Liu, Jianguo

    2011-01-21

    One of the major characteristics of tumors is their ability to evade immunosurveillance through altering the properties and functions of host stromal and/or immune cells. CCL5 has been shown to play important roles in T cell proliferation, IFN-γ, and IL-2 production, which promotes the differentiation and proliferation of Th1 cells important for immune defense against intracellular infection. In this study we found that tumor-bearing mice were more susceptible to bacterial infection and showed reduced CCL5 levels in serum during endotoxic shock. Our data further demonstrated that the soluble factors secreted by mammary gland tumor cells but not normal mammary gland epithelial cells inhibited CCL5 expression in macrophages in response to LPS, but not to TNF-α stimulation. The inhibitory effect of tumor-secreted molecules on LPS-induced CCL5 expression was regulated at the post-transcriptional level. Blocking PGE(2) synthesis by NS398 or through the use of PGE(2) receptor antagonists AH-6809 (EP2 antagonist) and AH-23848 (EP4 antagonist) completely reversed the inhibitory effect of tumor-conditioned medium (TCM) on LPS-induced CCL5 expression. Moreover, PGE(2) and the cAMP analog forskolin could mimic tumor-mediated CCL5 inhibition, and the inhibitory effects of TCM, PGE(2), and cAMP analog on LPS-induced CCL5 expression could be completely reversed by the PKA inhibitor H89. Furthermore, blocking PGE(2) synthesis in vivo led to partial recovery of CCL5 production during endotoxic shock. Taken together, our data indicate that PGE(2) secreted from breast cancer cells suppresses CCL5 secretion in LPS-activated macrophages through a cAMP/PKA signaling pathway, which may result in suppression of host immune responses against subsequent bacterial infection.

  20. Immunolocalization of adipocytes and prostaglandin E2 and its four receptor proteins EP1, EP2, EP3, and EP4 in the caprine cervix during spontaneous term labor.

    PubMed

    Gu, Guosheng; Gao, Qian; Yuan, Xuejun; Huang, Libo; Ge, Lijiang

    2012-05-01

    The mechanisms of cervical ripening and dilation in mammals remain obscure. Information is lacking about the localization of prostaglandin E(2) (PGE(2))-producing cells and PGE(2) receptors (EP) in intrapartum cervix and whether cervical dilation at parturition is an active process. To reveal these mechanisms, immunolocalization of EP1-EP4 (official gene symbols PTGER1-PTGER4) and PGE(2)-producing cells in caprine cervix during nonpregnancy, pregnancy, and parturition was assayed by immunohistochemistry (IHC); the mRNA expression levels of PTGS2, PTGER2 (EP2), and PTGER4 (EP4) were determined using quantitative PCR; and the existence of adipocytes in the cervix at various stages was demonstrated with Oil Red O staining and IHC of perilipin A. The results suggested that in intrapartum caprine cervix staining of the PGE(2) was observed in the overall tissues, for example, blood vessels, canal or glandular epithelia, serosa, circular and longitudinal muscles, and stroma in addition to adipocytes; EP2 was detectable in all the tissues other than glandular epithelia; EP4 was strongly expressed in all the tissues other than serosa; EP1 was detected mainly in arterioles and canal or glandular epithelia; and EP3 was poorly expressed only in stroma, canal epithelia, and circular muscles. Little or no expression of EP2, EP3, and EP4 as well as PGE(2) in all cervical tissues was observed during nonpregnancy and pregnancy except for the strong expression of EP1 in canal or glandular epithelia during pregnancy. The mRNA expression levels of PTGS2, PTGER2, and PTGER4 were significantly higher in intrapartum than nonpregnant and midpregnant cervices (P < 0.01). Adipocytes appear only in the intrapartum cervix. These results support the concept that PGE(2) modulates specific functions in various anatomical structures of the caprine cervix at labor and the appearance of adipocytes at labor is likely related to caprine cervical dilation.

  1. Impact of maternal dexamethasone on coronary PGE2 production and prostaglandin-dependent coronary reactivity

    PubMed Central

    Volk, Kenneth A.; Lamb, Fred S.; Segar, Jeffrey L.

    2012-01-01

    Intrauterine growth restriction is associated with increased fetal glucocorticoid exposure and an increased risk of adult coronary artery disease. Coronary arteries from sheep exposed to early gestation dexamethasone (Dex) have increased constriction to angiotensin II (ANG II). Prostaglandin E2 (PGE2) helps maintain coronary dilation, but PGE2 production is acutely decreased by Dex administration. We hypothesized early gestation Dex exposure impairs adult coronary PGE2 production with subsequent increases in coronary reactivity. Dex was administered to ewes at 27–28 days gestation (term 145 days). Coronary reactivity was assessed by wire myography in offspring at 4 mo of age (N = 5 to 7). Coronary smooth muscle cells were cultured and prostaglandin production was measured after 90 min incubation with radiolabeled arachidonate. Coronary myocytes from Dex-exposed lambs had a significant decrease in PGE2 production that was reversed with ANG II incubation. Dex-exposed coronary arteries had increased constriction to ANG II and attenuated dilatation to arachidonic acid, with the greatest difference seen after the endothelium was inactivated by rubbing. Preincubation with the cyclooxygenase (COX) inhibitor indomethacin altered control responses and recapitulated the heightened coronary tone seen following Dex exposure. We conclude that impaired coronary smooth muscle COX-mediated PGE2 production contributes to the coronary dysfunction elicited by early gestation Dex. Programmed inhibition of vasodilatory prostanoid production may link an adverse intrauterine environment with adult coronary artery disease. PMID:22832534

  2. Antigenicity of primary endodontic infection against macrophages by the levels of PGE(2) production.

    PubMed

    Martinho, Frederico C; Chiesa, Wanderson Miguel Maia; Leite, Fabio R M; Cirelli, Joni A; Gomes, Brenda P F A

    2011-05-01

    Root canal contents are potent stimuli for proinflammatory cytokines involved in apical periodontitis. This study investigated target gram-negative bacterial species and endotoxins in primary endodontic infection with apical periodontitis, determined their antigenicity against macrophages through the levels of PGE(2), and evaluated their relationship with clinical findings. Samples were taken from 21 root canals with primary infection and apical periodontitis by using paper points. Polymerase chain reaction (16S rDNA) was used for bacterial detection and limulus amebocyte lysate assay for endotoxin measurement. Levels of prostaglandin E2 (PGE(2)) were measured by enzyme-linked immunosorbent assay (Duoset Kit; R&D, Minneapolis, MN). Prevotella nigrescens (13/21), Fusobacterium nucleatum (6/21), and Porphyromonas endodontalis (6/21) were the most frequently observed species. A positive association was found between F. nucleatum and P. endodontalis (P < .05). A correlation was found between the number of gram-negative bacterial species and the levels of endotoxins, such as PGE(2) (P < .05). Higher levels of endotoxin were detected in teeth with exudation, whereas elevated levels of PGE(2) were found in teeth with tenderness to percussion and pain on palpation. Our findings imply an additive effect between the number of gram-negative bacterial species involved in endodontic infection regarding the induction of proinflammatory cytokine by macrophage cells. Moreover, teeth with clinical symptomatology were related to higher levels of endotoxins and PGE(2) secretion. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. A selective EP4 PGE2 receptor agonist alleviates disease in a new mouse model of X-linked nephrogenic diabetes insipidus

    PubMed Central

    Li, Jian Hua; Chou, Chung-Lin; Li, Bo; Gavrilova, Oksana; Eisner, Christoph; Schnermann, Jürgen; Anderson, Stasia A.; Deng, Chu-Xia; Knepper, Mark A.; Wess, Jürgen

    2009-01-01

    X-linked nephrogenic diabetes insipidus (XNDI) is a severe kidney disease caused by inactivating mutations in the V2 vasopressin receptor (V2R) gene that result in the loss of renal urine-concentrating ability. At present, no specific pharmacological therapy has been developed for XNDI, primarily due to the lack of suitable animal models. To develop what we believe to be the first viable animal model of XNDI, we generated mice in which the V2R gene could be conditionally deleted during adulthood by administration of 4-OH-tamoxifen. Radioligand-binding studies confirmed the lack of V2R-binding sites in kidneys following 4-OH-tamoxifen treatment, and further analysis indicated that upon V2R deletion, adult mice displayed all characteristic symptoms of XNDI, including polyuria, polydipsia, and resistance to the antidiuretic actions of vasopressin. Gene expression analysis suggested that activation of renal EP4 PGE2 receptors might compensate for the lack of renal V2R activity in XNDI mice. Strikingly, both acute and chronic treatment of the mutant mice with a selective EP4 receptor agonist greatly reduced all major manifestations of XNDI, including changes in renal morphology. These physiological improvements were most likely due to a direct action on EP4 receptors expressed on collecting duct cells. These findings illustrate the usefulness of the newly generated V2R mutant mice for elucidating and testing new strategies for the potential treatment of humans with XNDI. PMID:19729836

  4. E-type prostanoid receptor 4 (EP4) in disease and therapy

    PubMed Central

    Konya, Viktoria; Marsche, Gunther; Schuligoi, Rufina; Heinemann, Akos

    2013-01-01

    The large variety of biological functions governed by prostaglandin (PG) E2 is mediated by signaling through four distinct E-type prostanoid (EP) receptors. The availability of mouse strains with genetic ablation of each EP receptor subtype and the development of selective EP agonists and antagonists have tremendously advanced our understanding of PGE2 as a physiologically and clinically relevant mediator. Moreover, studies using disease models revealed numerous conditions in which distinct EP receptors might be exploited therapeutically. In this context, the EP4 receptor is currently emerging as most versatile and promising among PGE2 receptors. Anti-inflammatory, anti-thrombotic and vasoprotective effects have been proposed for the EP4 receptor, along with its recently described unfavorable tumor-promoting and pro-angiogenic roles. A possible explanation for the diverse biological functions of EP4 might be the multiple signaling pathways switched on upon EP4 activation. The present review attempts to summarize the EP4 receptor-triggered signaling modules and the possible therapeutic applications of EP4-selective agonists and antagonists. PMID:23523686

  5. COX-2/mPGES-1/PGE2 cascade activation mediates uric acid-induced mesangial cell proliferation.

    PubMed

    Li, Shuzhen; Sun, Zhenzhen; Zhang, Yue; Ruan, Yuan; Chen, Qiuxia; Gong, Wei; Yu, Jing; Xia, Weiwei; He, John Ci-Jiang; Huang, Songming; Zhang, Aihua; Ding, Guixia; Jia, Zhanjun

    2017-02-07

    Hyperuricemia is not only the main feature of gout but also a cause of gout-related organ injuries including glomerular hypertrophy and sclerosis. Uric acid (UA) has been proven to directly cause mesangial cell (MC) proliferation with elusive mechanisms. The present study was undertaken to examined the role of inflammatory cascade of COX-2/mPGES-1/PGE2 in UA-induced MC proliferation. In the dose- and time-dependent experiments, UA increased cell proliferation shown by the increased total cell number, DNA synthesis rate, and the number of cells in S and G2 phases in parallel with the upregulation of cyclin A2 and cyclin D1. Interestingly, UA-induced cell proliferation was accompanied with the upregulation of COX-2 and mPGES-1 at both mRNA and protein levels. Strikingly, inhibition of COX-2 via a specific COX-2 inhibitor NS-398 markedly blocked UA-induced MC proliferation. Meanwhile, UA-induced PGE2 production was almost entirely abolished. Furthermore, inhibiting mPGES-1 by a siRNA approach in MCs also ameliorated UA-induced MC proliferation in line with a significant blockade of PGE2 secretion. More importantly, in gout patients, we observed a significant elevation of urinary PGE2 excretion compared with healthy controls, indicating a translational potential of this study to the clinic. In conclusion, our findings indicated that COX-2/mPGES-1/PGE2 cascade activation mediated UA-induced MC proliferation. This study offered new insights into the understanding and the intervention of UA-related glomerular injury.

  6. The importance of brain PGE2 inhibition versus paw PGE2 inhibition as a mechanism for the separation of analgesic and antipyretic effects of lornoxicam in rats with paw inflammation.

    PubMed

    Futaki, Nobuko; Harada, Masahiro; Sugimoto, Masanori; Hashimoto, Yuki; Honma, Yusuke; Arai, Iwao; Nakaike, Shiro; Hoshi, Keiko

    2009-05-01

    Lornoxicam is a non-selective cyclooxygenase inhibitor that exhibits strong analgesic and anti-inflammatory effects but a weak antipyretic effect in rat models. Our aim was to investigate the mechanism of separation of potencies or analgesic and antipyretic effects of lornoxicam in relation to its effect on prostaglandin E2 (PGE2) production in the inflammatory paw and the brain. A model of acute or chronic paw inflammation was induced by Freund's complete adjuvant injection into the rat paw. Lornoxicam (0.01-1 mg/kg), celecoxib (0.3-30 mg/kg) or loxoprofen (0.3-30 mg/kg) was administered orally to the rats and the analgesic and antipyretic effects were compared. The paw hyperalgesia was assessed using the Randall-Selitto test or the flexion test. Dorsal subcutaneous body temperature was measured as indicator of pyresis. After the measurement of activities, the rats were sacrificed and the PGE2 content in the paw exudate, cerebrospinal fluid or brain hypothalamus was measured by enzyme-immunoassay. In a chronic model of arthritis, lornoxicam, celecoxib and loxoprofen reduced hyperalgesia with an effective dose that provides 50% inhibition (ED50) of 0.083, 3.9 and 4.3 mg/kg respectively, whereas the effective dose of these drugs in pyresis was 0.58, 0.31 and 0.71 mg/kg respectively. These drugs significantly reduced the PGE2 level in paw exudate and the cerebrospinal fluid. In acute oedematous rats, lornoxicam 0.16 mg/kg, celecoxib 4 mg/kg and loxoprofen 2.4 mg/kg significantly reduced hyperalgesia to a similar extent. On the other hand, lornoxicam did not affect the elevated body temperature, whereas celecoxib and loxoprofen significantly reduced the pyrexia to almost the normal level. These drugs significantly reduced the PGE2 level in inflamed paw exudate lo almost the normal level. On the other hand, lornoxicam did not change PGE2 level in the brain hypothalamus, whereas celecoxib and loxoprofen strongly decreased it. Lornoxicam exhibits strong analgesic but

  7. COX2/mPGES1/PGE2 pathway regulates PD-L1 expression in tumor-associated macrophages and myeloid-derived suppressor cells

    PubMed Central

    Prima, Victor; Kaliberova, Lyudmila N.; Kaliberov, Sergey; Curiel, David T.; Kusmartsev, Sergei

    2017-01-01

    In recent years, it has been established that programmed cell death protein ligand 1 (PD-L1)–mediated inhibition of activated PD-1+ T lymphocytes plays a major role in tumor escape from immune system during cancer progression. Lately, the anti–PD-L1 and –PD-1 immune therapies have become an important tool for treatment of advanced human cancers, including bladder cancer. However, the underlying mechanisms of PD-L1 expression in cancer are not fully understood. We found that coculture of murine bone marrow cells with bladder tumor cells promoted strong expression of PD-L1 in bone marrow–derived myeloid cells. Tumor-induced expression of PD-L1 was limited to F4/80+ macrophages and Ly-6C+ myeloid-derived suppressor cells. These PD-L1–expressing cells were immunosuppressive and were capable of eliminating CD8 T cells in vitro. Tumor-infiltrating PD-L1+ cells isolated from tumor-bearing mice also exerted morphology of tumor-associated macrophages and expressed high levels of prostaglandin E2 (PGE2)-forming enzymes microsomal PGE2 synthase 1 (mPGES1) and COX2. Inhibition of PGE2 formation, using pharmacologic mPGES1 and COX2 inhibitors or genetic overexpression of PGE2-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH), resulted in reduced PD-L1 expression. Together, our study demonstrates that the COX2/mPGES1/PGE2 pathway involved in the regulation of PD-L1 expression in tumor-infiltrating myeloid cells and, therefore, reprogramming of PGE2 metabolism in tumor microenvironment provides an opportunity to reduce immune suppression in tumor host. PMID:28096371

  8. Inhibition of anti-CD3 monoclonal antibody-induced T-cell proliferation and interleukin-2 secretion by physiologic combinations of dexamethasone and prostaglandin E2.

    PubMed

    Elliott, L; Brooks, W; Roszman, T

    1993-12-01

    1. The purpose of these studies was to characterize further previous observations from our laboratory indicating that physiologic concentrations of dexamethasone (DEX) and prostaglandin E2 (PGE2) added together result in synergistic inhibition of the proliferative response of T cells stimulated via the T-cell receptor CD3 signaling complex (TCR/CD3). 2. Various physiologic concentrations of DEX and PGE2 were added to T cells stimulated with immobilized anti-CD3 monoclonal antibody (mAb) and cultured at optimal and suboptimal cell densities. The results demonstrate that the proliferative response of anti-CD3 mAb-stimulated T cells cultured at a suboptimal cell density is more suppressed than that of T cells cultured at optimal concentrations. 3. The proliferative response of CD4+ T cells to immobilized anti-CD3 mAb was also determined in the presence of PGE2 and DEX. The data indicate that the CD4+ subset of T cells is more sensitive to the synergistic antiproliferative effects of DEX and PGE2 compared to whole T-cell populations. 4. Various concentrations of DEX and/or PGE2 were added to T cells stimulated with anti-CD3 mAb and the secretion of interleukin-2 (IL-2) was determined. The results demonstrate that concentrations of DEX and PGE2 which individually do not significantly suppress IL-2 synthesis act together to inhibit the synthesis of IL-2 synergistically. 5. The addition of an exogenous source of recombinant IL-2 (rIL-2) to T cells stimulated in the presence of DEX and PGE2 completely reversed the synergistic antiproliferative effect of these two compounds. This reversal was even more pronounced with T cells cultured at a suboptimal cell density. Additionally, PGE2 and DEX did not affect expression of the IL-2 receptor (IL-2R), as measured by upregulation of the alpha chain, on anti-CD3 mAb stimulated T cells. 6. Collectively these data indicate that physiologic concentrations of PGE2 and DEX, which alone have no effect on anti-CD3 mAb-induced T

  9. Prostaglandin E2 stimulates normal bronchial epithelial cell growth through induction of c-Jun and PDK1, a kinase implicated in oncogenesis.

    PubMed

    Fan, Yu; Wang, Ye; Wang, Ke

    2015-12-18

    Cyclooxygenase-2-derived prostaglandin E2 (PGE2), a bioactive eicosanoid, has been implicated in many biological processes including reproduction, inflammation and tumor growth. We previously showed that PGE2 stimulated lung cancer cell growth and progression through PGE2 receptor EP2/EP4-mediated kinase signaling pathways. However, the role of PGE2 in controlling lung airway epithelial cell phenotype remains unknown. We evaluated the effects of c-Jun and 3-phosphoinositede dependent protein kinase-1 (PDK1) in mediating epithelial cell hyperplasia induced by PGE2. The bronchial epithelial cell lines BEAS-2B and HBEc14-KT were cultured and then treated with PGE2. PDK1 small interfering RNA (siRNA) and a PDK1 inhibitor, an antagonist of the PGE2 receptor subtype EP4 and EP4 siRNA, c-Jun siRNA, and overexpressions of c-Jun and PDK1 have been used to evaluate the effects on cell proliferation. We demonstrated that PGE2 increased normal bronchial epithelial cell proliferation through induction of PDK1, an ankyrin repeat-containing Ser/Thr kinase implicated in the induction of apoptosis and the suppression of tumor growth. PDK1 siRNA and a PDK1 inhibitor blocked the effects of PGE2 on normal cell growth. The PGE2-induced PDK1 expression was blocked by an antagonist of the PGE2 receptor subtype EP4 and by EP4 siRNA. In addition, we showed that induction of PDK1 by PGE2 was associated with induction of the transcription factor, c-Jun protein. Silencing of c-Jun using siRNA and point mutations of c-Jun sites in the PDK1 gene promoter resulted in blockade of PDK1 expression and promoter activity induced by PGE2. In contrast, overexpression of c-Jun induced PDK1 gene promoter activity and expression followed increased cell proliferation. PGE2 increases normal bronchial epithelial cell proliferation through increased PDK1 gene expression that is dependent on EP4 and induction of c-Jun. Therewith, our data suggest a new role of c-Jun and PDK1 in mediating epithelial cell

  10. Prostaglandin E2 Stimulates EP2, Adenylate Cyclase, Phospholipase C, and Intracellular Calcium Release to Mediate Cyclic Adenosine Monophosphate Production in Dental Pulp Cells.

    PubMed

    Chang, Mei-Chi; Lin, Szu-I; Lin, Li-Deh; Chan, Chiu-Po; Lee, Ming-Shu; Wang, Tong-Mei; Jeng, Po-Yuan; Yeung, Sin-Yuet; Jeng, Jiiang-Huei

    2016-04-01

    Prostaglandin E2 (PGE2) plays a crucial role in pulpal inflammation and repair. However, its induction of signal transduction pathways is not clear but is crucial for future control of pulpal inflammation. Primary dental pulp cells were exposed to PGE2 and 19R-OH PGE2 (EP2 agonist) or sulprostone (EP1/EP3 agonist) for 5 to 40 minutes. Cellular cyclic adenosine monophosphate (cAMP) levels were measured using the enzyme-linked immunosorbent assay. In some experiments, cells were pretreated with SQ22536 (adenylate cyclase inhibitor), H89 (protein kinase A inhibitor), dorsomorphin (adenosine monophosphate-activated protein kinase inhibitor), U73122 (phospholipase C inhibitor), thapsigargin (inhibitor of intracellular calcium release), W7 (calmodulin antagonist), verapamil (L-type calcium channel blocker), and EGTA (extracellular calcium chelator) for 20 minutes before the addition of PGE2. PGE2 and 19R-OH PGE2 (EP2 agonist) stimulated cAMP production, whereas sulprostone (EP1/EP3 agonist) shows little effect. PGE2-induced cAMP production was attenuated by SQ22536 and U73122 but not H89 and dorsomorphin. Intriguingly, thapsigargin and W7 prevented PGE2-induced cAMP production, but verapamil and EGTA showed little effect. These results indicate that PGE2-induced cAMP production is associated with EP2 receptor and adenylate cyclase activation. These events are mediated by phospholipase C, intracellular calcium release, and calcium-calmodulin signaling. These results are helpful for understanding the role of PGE2 in pulpal inflammation and repair and possible future drug intervention. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Intrauterine group A streptococcal infections are exacerbated by prostaglandin E2.

    PubMed

    Mason, Katie L; Rogers, Lisa M; Soares, Elyara M; Bani-Hashemi, Tara; Erb Downward, John; Agnew, Dalen; Peters-Golden, Marc; Weinberg, Jason B; Crofford, Leslie J; Aronoff, David M

    2013-09-01

    Streptococcus pyogenes (Group A Streptococcus; GAS) is a major cause of severe postpartum sepsis, a re-emerging cause of maternal morbidity and mortality worldwide. Immunological alterations occur during pregnancy to promote maternofetal tolerance, which may increase the risk for puerperal infection. PGE2 is an immunomodulatory lipid that regulates maternofetal tolerance, parturition, and innate immunity. The extent to which PGE2 regulates host immune responses to GAS infections in the context of endometritis is unknown. To address this, both an in vivo mouse intrauterine (i.u.) GAS infection model and an in vitro human macrophage-GAS interaction model were used. In C57BL/6 mice, i.u. GAS inoculation resulted in local and systemic inflammatory responses and triggered extensive changes in the expression of eicosanoid pathway genes. The i.u. administration of PGE2 increased the mortality of infected mice, suppressed local IL-6 and IL-17A levels, enhanced neutrophilic inflammation, reduced uterine macrophage populations, and increased bacterial dissemination. A role for endogenous PGE2 in the modulation of antistreptococcal host defense was suggested, because mice lacking the genes encoding the microsomal PGE2 synthase-1 or the EP2 receptor were protected from death, as were mice treated with the EP4 receptor antagonist, GW627368X. PGE2 also regulated GAS-macrophage interactions. In GAS-infected human THP-1 (macrophage-like) cells, PGE2 inhibited the production of MCP-1 and TNF-α while augmenting IL-10 expression. PGE2 also impaired the phagocytic ability of human placental macrophages, THP-1 cells, and mouse peritoneal macrophages in vitro. Exploring the targeted disruption of PGE2 synthesis and signaling to optimize existing antimicrobial therapies against GAS may be warranted.

  12. Characterization of biosynthesis and modes of action of prostaglandin E2 and prostacyclin in guinea pig mesenteric lymphatic vessels.

    PubMed

    Rehal, Sonia; Blanckaert, Pauline; Roizes, Simon; von der Weid, Pierre-Yves

    2009-12-01

    Rhythmical transient constrictions of the lymphatic vessels provide the means for efficient lymph drainage and interstitial tissue fluid balance. This activity is critical during inflammation, to avoid or limit oedema resulting from increased vascular permeability, mediated by the release of various inflammatory mediators. In this study, we investigated the mechanisms by which prostaglandin E(2) (PGE(2)) and prostacyclin modulate lymphatic contractility in isolated guinea pig mesenteric lymphatic vessels. Quantitative RT-PCR was used to assess the expression of mRNA for enzymes and receptors involved in the production and action of PGE(2) and prostacyclin in mesenteric collecting lymphatic vessels. Frequency and amplitude of lymphatic vessel constriction were measured in the presence of these prostaglandins and the role of their respective EP and IP receptors assessed. Prostaglandin E(2) and prostacyclin decreased concentration-dependently the frequency, without affecting the amplitude, of lymphatic constriction. Data obtained in the presence of the EP(4) receptor antagonists, GW627368x (1 microM) and AH23848B (30 microM) and the IP receptor antagonist CAY10441 (0.1 microM) suggest that PGE(2) predominantly activates EP(4), whereas prostacyclin mainly stimulates IP receptors. Inhibition of responses to either prostaglandin with H89 (10 microM) or glibenclamide (1 microM) suggested a role for the activation of protein kinase A and ATP-sensitive K(+) channels. Our findings characterized the inhibition of lymphatic pumping induced by PGE(2) or prostacyclin in guinea pig mesenteric lymphatics. This action is likely to impair oedema resolution and to contribute to the pro-inflammatory actions of these prostaglandins.

  13. Prostaglandin E2 regulates B cell proliferation through a candidate tumor suppressor, Ptger4.

    PubMed

    Murn, Jernej; Alibert, Olivier; Wu, Ning; Tendil, Simon; Gidrol, Xavier

    2008-12-22

    B cell receptor (BCR) signaling contributes to the pathogenesis of B cell malignancies, and most B cell lymphomas depend on BCR signals for survival. Identification of genes that restrain BCR-mediated proliferation is therefore an important goal toward improving the therapy of B cell lymphoma. Here, we identify Ptger4 as a negative feedback regulator of proliferation in response to BCR signals and show that its encoded EP4 receptor is a principal molecule conveying the growth-suppressive effect of prostaglandin E2 (PGE2). Stable knockdown of Ptger4 in B cell lymphoma markedly accelerated tumor spread in mice, whereas Ptger4 overexpression yielded significant protection. Mechanistically, we show that the intrinsic activity of Ptger4 and PGE2-EP4 signaling target a similar set of activating genes, and find Ptger4 to be significantly down-regulated in human B cell lymphoma. We postulate that Ptger4 functions in B cells as a candidate tumor suppressor whose activity is regulated by PGE2 in the microenvironment. These findings suggest that targeting EP4 receptor for prostaglandin may present a novel strategy for treatment of B cell malignancies.

  14. Prostaglandin E2 regulates B cell proliferation through a candidate tumor suppressor, Ptger4

    PubMed Central

    Murn, Jernej; Alibert, Olivier; Wu, Ning; Tendil, Simon; Gidrol, Xavier

    2008-01-01

    B cell receptor (BCR) signaling contributes to the pathogenesis of B cell malignancies, and most B cell lymphomas depend on BCR signals for survival. Identification of genes that restrain BCR-mediated proliferation is therefore an important goal toward improving the therapy of B cell lymphoma. Here, we identify Ptger4 as a negative feedback regulator of proliferation in response to BCR signals and show that its encoded EP4 receptor is a principal molecule conveying the growth-suppressive effect of prostaglandin E2 (PGE2). Stable knockdown of Ptger4 in B cell lymphoma markedly accelerated tumor spread in mice, whereas Ptger4 overexpression yielded significant protection. Mechanistically, we show that the intrinsic activity of Ptger4 and PGE2–EP4 signaling target a similar set of activating genes, and find Ptger4 to be significantly down-regulated in human B cell lymphoma. We postulate that Ptger4 functions in B cells as a candidate tumor suppressor whose activity is regulated by PGE2 in the microenvironment. These findings suggest that targeting EP4 receptor for prostaglandin may present a novel strategy for treatment of B cell malignancies. PMID:19075289

  15. Signaling of Prostaglandin E Receptors, EP3 and EP4 Facilitates Wound Healing and Lymphangiogenesis with Enhanced Recruitment of M2 Macrophages in Mice.

    PubMed

    Hosono, Kanako; Isonaka, Risa; Kawakami, Tadashi; Narumiya, Shuh; Majima, Masataka

    2016-01-01

    Lymphangiogenesis plays an important role in homeostasis, metabolism, and immunity, and also occurs during wound-healing. Here, we examined the roles of prostaglandin E2 (PGE2) receptor (EP) signaling in enhancement of lymphangiogenesis in wound healing processes. The hole-punch was made in the ears of male C57BL/6 mice using a metal ear punch. Healing process and lymphangiogenesis together with macrophage recruitment were analyzed in EP knockout mice. Lymphangiogenesis was up-regulated in the granulation tissues at the margins of punched-hole wounds in mouse ears, and this increase was accompanied by increased expression levels of COX-2 and microsomal prostaglandin E synthase-1. Administration of celecoxib, a COX-2 inhibitor, suppressed lymphangiogenesis in the granulation tissues and reduced the induction of the pro-lymphangiogenic factors, vascular endothelial growth factor (VEGF) -C and VEGF-D. Topical applications of selective EP receptor agonists enhanced the expressions of lymphatic vessel endothelial hyaluronan receptor-1 and VEGF receptor-3. The wound-healing processes and recruitment of CD11b-positive macrophages, which produced VEGF-C and VEGF-D, were suppressed under COX-2 inhibition. Mice lacking either EP3 or EP4 exhibited reduced wound-healing, lymphangiogenesis and recruitment of M2 macrophages, compared with wild type mice. Proliferation of cultured human lymphatic endothelial cells was not detected under PGE2 stimulation. Lymphangiogenesis and recruitment of M2 macrophages that produced VEGF-C/D were suppressed in mice treated with a COX-2 inhibitor or lacking either EP3 or EP4 during wound healing. COX-2 and EP3/EP4 signaling may be novel targets to control lymphangiogenesis in vivo.

  16. Selective inhibition of prostaglandin E2 receptors EP2 and EP4 induces apoptosis of human endometriotic cells through suppression of ERK1/2, AKT, NFkappaB, and beta-catenin pathways and activation of intrinsic apoptotic mechanisms.

    PubMed

    Banu, Sakhila K; Lee, JeHoon; Speights, V O; Starzinski-Powitz, Anna; Arosh, Joe A

    2009-08-01

    Endometriosis is a benign chronic gynecological disease of reproductive-age women characterized by the presence of functional endometrial tissues outside the uterine cavity. It is an estrogen-dependent disease. Current treatment modalities to inhibit biosynthesis and actions of estrogen compromise menstruation, pregnancy, and the reproductive health of women and fail to prevent reoccurrence of disease. There is a critical need to identify new specific signaling modules for non-estrogen-targeted therapies for endometriosis. In our previous study, we reported that selective inhibition of cyclooxygenase-2 prevented survival, migration, and invasion of human endometriotic epithelial and stromal cells, which was due to decreased prostaglandin E(2) (PGE(2)) production. In this study, we determined mechanisms through which PGE(2) promoted survival of human endometriotic cells. Results of the present study indicate that 1) PGE(2) promotes survival of human endometriotic cells through EP2 and EP4 receptors by activating ERK1/2, AKT, nuclear factor-kappaB, and beta-catenin signaling pathways; 2) selective inhibition of EP2 and EP4 suppresses these cell survival pathways and augments interactions between proapoptotic proteins (Bax and Bad) and antiapoptotic proteins (Bcl-2/Bcl-XL), facilitates the release of cytochrome c, and thus activates caspase-3/poly (ADP-ribose) polymerase-mediated intrinsic apoptotic pathways; and 3) these PGE(2) signaling components are more abundantly expressed in ectopic endometriosis tissues compared with eutopic endometrial tissues during the menstrual cycle in women. These novel findings may provide an important molecular framework for further evaluation of selective inhibition of EP2 and EP4 as potential therapy, including nonestrogen target, to expand the spectrum of currently available treatment options for endometriosis in women.

  17. Prostaglandin E2 blocks menadione-induced apoptosis through the Ras/Raf/Erk signaling pathway in promonocytic leukemia cell lines.

    PubMed

    Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

    2012-04-01

    Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E(2) (PGE(2)) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE(2) as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE(2) markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP(2) receptor antagonist AH6809 abrogated the inhibitory effect of PGE(2), suggesting the role of the EP(2)/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE(2). The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE(2) on menadione-treated cells. Furthermore, PGE(2) activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE(2) via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics.

  18. Prostaglandin E2 Blocks Menadione-Induced Apoptosis through the Ras/Raf/Erk Signaling Pathway in Promonocytic Leukemia Cell Lines

    PubMed Central

    Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

    2012-01-01

    Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E2 (PGE2) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE2 as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE2 markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP2 receptor antagonist AH6809 abrogated the inhibitory effect of PGE2, suggesting the role of the EP2/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE2. The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE2 on menadione-treated cells. Furthermore, PGE2 activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE2 via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics. PMID:22450688

  19. Hyaluronan inhibits prostaglandin E2 production via CD44 in U937 human macrophages.

    PubMed

    Yasuda, Tadashi

    2010-03-01

    Prostaglandin E(2) (PGE(2)) is one of the key mediators of inflammation in affected joints of rheumatoid arthritis (RA). Intra-articular injection of high molecular weight hyaluronan (HA) into RA knee joints relieves arthritic pain. Although HA has been shown to inhibit PGE(2) production in cytokine-stimulated synovial fibroblasts, it remains unclear how HA suppresses PGE(2) production in activated cells. Furthermore, HA effect on macrophages has rarely been investigated in spite of their contribution to RA joint pathology. This study was aimed to investigate the inhibitory mechanism of HA on lipopolysaccharide (LPS)-stimulated PGE(2) production in U937 human macrophages. Stimulation of U937 macrophages with LPS enhanced PGE(2) production in association with increased protein levels of cyclooxygenase-2 (COX-2). Pretreatment with HA of 2,700 kDa resulted in suppression of the LPS-mediated induction of COX-2, leading to a decrease in PGE(2) production. Likewise, the LPS-stimulated PGE(2) production was inhibited by the pretreatment with a specific COX2 inhibitor, NS-398, or a specific inhibitor of nuclear factor (NF)-kappaB, BAY11-7085. HA also decreased the degree of phosphorylation and nuclear translocation of NF-kappaB enhanced by LPS. Fluorescence cytochemistry demonstrated that HA bound to CD44, the principal HA receptor, on U937 macrophages. Anti-CD44 antibody reversed the inhibitory effects of HA on the LPS-mediated increase in PGE(2) production, COX-2 induction, and activation of NF-kappaB. These results indicate that HA suppresses the LPS-stimulated PGE(2) production via CD44 through down-regulation of NF-kappaB. Administration of HA into RA joints may decrease PGE(2) production by activated macrophages, which could result in improvement of arthritic pain.

  20. Arginine vasopressin antagonizes the effects of prostaglandin E2 on the spontaneous activity of warm-sensitive and temperature-insensitive neurons in the medial preoptic area in rats.

    PubMed

    Xu, Jian-Hui; Hou, Xiao-Yu; Tang, Yu; Luo, Rong; Zhang, Jie; Liu, Chang; Yang, Yong-Lu

    2018-01-01

    Arginine vasopressin (AVP) plays an important role in thermoregulation and antipyresis. We have demonstrated that AVP could change the spontaneous activity of thermosensitive and temperature insensitive neurons in the preoptic area. However, whether AVP influences the effects of prostaglandin E 2 (PGE 2 ) on the spontaneous activity of neurons in the medial preoptic area (MPO) remains unclear. Our experiment showed that PGE 2 decreased the spontaneous activity of warm-sensitive neurons, and increased that of low-slope temperature-insensitive neurons in the MPO. AVP attenuated the inhibitory effect of PGE 2 on warm-sensitive neurons, and reversed the excitatory effect of PGE 2 on low-slope temperature-insensitive neurons, demonstrating that AVP antagonized the effects of PGE 2 on the spontaneous activity of these neurons. The effect of AVP was suppressed by an AVP V 1a receptor antagonist, suggesting that V 1a receptor mediated the action of AVP. We also demonstrated that AVP attenuated the PGE 2 -induced decrease in the prepotential's rate of rise in warm-sensitive neurons and the PGE 2 -induced increase in that in low-slope temperature-insensitive neurons through the V 1a receptor. Together, these data indicated that AVP antagonized the PGE 2 -induced change in the spontaneous activity of warm-sensitive and low-slope temperature-insensitive neurons in the MPO partly by reducing the PGE 2 -induced change in the prepotential of these neurons in a V 1a receptor-dependent manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Fibroblast growth factor-23 increases mouse PGE2 production in vivo and in vitro.

    PubMed

    Syal, Ashu; Schiavi, Susan; Chakravarty, Sumana; Dwarakanath, Vangipuram; Quigley, Raymond; Baum, Michel

    2006-02-01

    Fibroblast growth factor-23 (FGF-23) has been implicated in the renal phosphate wasting in X-linked hypophosphatemia, tumor-induced osteomalacia, and autosomal dominant hypophosphatemic rickets. Recently, we demonstrated that Hyp mice have greater urinary PGE2 levels compared with C57/B6 mice and that indomethacin administration in vivo and in vitro ameliorates the phosphate transport defect in Hyp mice. To determine further whether altered prostaglandin metabolism plays a role in the renal phosphate transport defect in Hyp mice, we incubated renal proximal tubules with arachidonic acid. We find that PGE2 production was higher in Hyp mice than in C57/B6 mice. Incubation of C57/B6 mouse renal proximal tubules with FGF-23R176Q, an active mutant form of FGR23, increased tubular PGE2 production, an effect that was inhibited by 50 microM PD-98059 and 10 microM SB-203580, inhibitors of the MAP kinase pathway. C57/B6 mice injected with FGF-23R176Q had a approximately 10-fold increase in PGE2 excretion 24 h after intraperitoneal injection of FGF-23R176Q compared with vehicle-treated controls. Finally, we show that PGE2 inhibited both phosphate and volume absorption in mouse proximal convoluted tubules perfused in vitro and reduced brush-border membrane vesicle NaPi-2a protein abundance from renal cortex incubated in vitro with PGE2. In conclusion, FGF-23 increases urinary and renal tubular PGE2 production via the MAP kinase pathway and PGE2 inhibits proximal tubule phosphate transport.

  2. Fibroblast growth factor-23 increases mouse PGE2 production in vivo and in vitro

    PubMed Central

    Syal, Ashu; Schiavi, Susan; Chakravarty, Sumana; Dwarakanath, Vangipuram; Quigley, Raymond; Baum, Michel

    2014-01-01

    Fibroblast growth factor-23 (FGF-23) has been implicated in the renal phosphate wasting in X-linked hypophosphatemia, tumor-induced osteomalacia, and autosomal dominant hypophosphatemic rickets. Recently, we demonstrated that Hyp mice have greater urinary PGE2 levels compared with C57/B6 mice and that indomethacin administration in vivo and in vitro ameliorates the phosphate transport defect in Hyp mice. To determine further whether altered prostaglandin metabolism plays a role in the renal phosphate transport defect in Hyp mice, we incubated renal proximal tubules with arachidonic acid. We find that PGE2 production was higher in Hyp mice than in C57/B6 mice. Incubation of C57/B6 mouse renal proximal tubules with FGF-23R176Q, an active mutant form of FGR23, increased tubular PGE2 production, an effect that was inhibited by 50 μM PD-98059 and 10 μM SB-203580, inhibitors of the MAP kinase pathway. C57/B6 mice injected with FGF-23R176Q had a ~10-fold increase in PGE2 excretion 24 h after intraperitoneal injection of FGF-23R176Q compared with vehicle-treated controls. Finally, we show that PGE2 inhibited both phosphate and volume absorption in mouse proximal convoluted tubules perfused in vitro and reduced brush-border membrane vesicle NaPi-2a protein abundance from renal cortex incubated in vitro with PGE2. In conclusion, FGF-23 increases urinary and renal tubular PGE2 production via the MAP kinase pathway and PGE2 inhibits proximal tubule phosphate transport. PMID:16144964

  3. CYP2S1 depletion enhances colorectal cell proliferation is associated with PGE2-mediated activation of β-catenin signaling.

    PubMed

    Yang, Chao; Li, Changyuan; Li, Minle; Tong, Xuemei; Hu, Xiaowen; Yang, Xuhan; Yan, Xiaomei; He, Lin; Wan, Chunling

    2015-02-15

    Colorectal epithelial cancer is one of the most common cancers in the world and its 5-year survival rate is still relatively low. Cytochrome P450 (CYP) enzymes in epithelial cells lining the alimentary tract play an important role in the oxidative metabolism of a wide range of xenobiotics, including (pro-)carcinogens and endogenous compounds. Although CYP2S1, a member of CYP family, strongly expressed in many extrahepatic tissues, the role of CYP2S1 in cancer remains unclear. To investigate whether CYP2S1 involves in colorectal carcinogenesis, cell proliferation was analyzed in HCT116 cells depleted of CYP2S1 using small hairpin interfering RNA. Our data show that CYP2S1 knockdown promotes cell proliferation through increasing the level of endogenous prostaglandin E2(PGE2). PGE2, in turn, reduces phosphorylation of β-catenin and activates β-catenin signaling, which contributes to the cell proliferation. Furthermore, CYP2S1 knockdown increase tumor growth in xenograft mouse model. In brief, these results demonstrate that CYP2S1 regulates colorectal cancer growth through associated with PGE2-mediated activation of β-catenin signaling. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

    NASA Technical Reports Server (NTRS)

    Chen, Y.; Hughes-Fulford, M.

    2000-01-01

    Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

  5. Prostaglandin E2 inhibits Tr1 cell differentiation through suppression of c-Maf

    PubMed Central

    Hooper, Kirsten Mary; Kong, Weimin

    2017-01-01

    Prostaglandin E2 (PGE2), a major lipid mediator abundant at inflammatory sites, acts as a proinflammatory agent in models of inflammatory/autoimmune diseases by promoting CD4 Th1/Th17 differentiation. Regulatory T cells, including the IL-10 producing Tr1 cells counterbalance the proinflammatory activity of effector Th1/Th17 cells. Tr1 cell differentiation and function are induced by IL-27, and depend primarily on sustained expression of c-Maf in addition to AhR and Blimp-1. In agreement with the in vivo proinflammatory role of PGE2, here we report for the first time that PGE2 inhibits IL-27-induced differentiation and IL-10 production of murine CD4+CD49b+LAG-3+Foxp3- Tr1 cells. The inhibitory effect of PGE2 was mediated through EP4 receptors and induction of cAMP, leading to a significant reduction in c-Maf expression. Although PGE2 reduced IL-21 production in differentiating Tr1 cells, its inhibitory effect on Tr1 differentiation and c-Maf expression also occurred independent of IL-21 signaling. PGE2 did not affect STAT1/3 activation, AhR expression and only marginally reduced Egr-2/Blimp-1 expression. The effect of PGE2 on CD4+CD49b+LAG-3+ Tr1 differentiation was not associated with either induction of Foxp3 or IL-17 production, suggesting a lack of transdifferentiation into Foxp3+ Treg or effector Th17 cells. We recently reported that PGE2 inhibits the expression and production of IL-27 from activated conventional dendritic cells (cDC) in vivo and in vitro. The present study indicates that PGE2 also reduces murine Tr1 differentiation and function directly by acting on IL-27-differentiating Tr1 cells. Together, the ability of PGE2 to inhibit IL-27 production by cDC, and the direct inhibitory effect on Tr1 differentiation mediated through reduction in c-Maf expression, represent a new mechanistic perspective for the proinflammatory activity of PGE2. PMID:28604806

  6. Estrogen receptors regulate the estrous behavior induced by progestins, peptides, and prostaglandin E2.

    PubMed

    Lima-Hernández, F J; Gómora-Arrati, P; García-Juárez, M; Blaustein, J D; Etgen, A M; Beyer, C; González-Flores, O

    2014-07-01

    The role of classical estrogen receptors (ERs) in priming female reproductive behavior has been studied previously; however, the participation of this receptor during activation of estrous behavior has not been extensively studied. The purpose of this work was to test the possibility that the facilitation of lordosis behavior in estrogen-primed rats by progesterone (P) and its 5α- and 5β-reduced metabolites, gonadotropin-releasing hormone (GnRH), leptin, prostaglandin E2 (PGE2) and vagino-cervical stimulation (VCS) involves interactions with classical ERs by using the selective ER modulator, tamoxifen. To further assess the role of ERs, we also explored the effects of the pure ER antagonist, ICI182780 (ICI), on estrous behavior induced by P and GnRH. Ovariectomized, estrogen-primed rats (5μg estradiol benzoate 40h earlier) were injected intraventricularly with the above-mentioned compounds, or they received VCS. All compounds and VCS effectively facilitated estrous behavior when tested at 60, 120 or 240min after infusion or application of VCS. Intraventricular infusion of tamoxifen (5μg), 30min before, significantly attenuated estrous behaviors induced in estradiol-primed rats by P, most of its 5α- and 5β-reduced metabolites, GnRH, and PGE2, but not by VCS. Although there was a trend for reduction, tamoxifen did not significantly decrease lordosis in females treated with 5β-pregnan-3,20-dione. ICI also inhibited lordosis behavior induced by P and GnRH at some testing intervals. These results suggest that activation of classical ERs participates in the triggering effects on estrous behavior induced by agents with different chemical structures that do not bind directly to ERs. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Rebamipide retards CCl4-induced hepatic fibrosis in rats: Possible role for PGE2.

    PubMed

    Zakaria, Sherin; El-Sisi, Alaa

    2016-07-01

    Prostaglandin E2 (PGE2) is a potent physiological suppressor of liver fibrosis. Because the anti-ulcer drug rebamipide can induce the formation of endogenous PGE2, this study investigated the potential effects of rebamipide on development of a hepatic fibrosis that was inducible by carbon tetrachloride (CCl4). Groups of Wistar rats received intraperitoneal (IP) injections of CCl4 (0.45 ml/kg [0.72 g CCl4/kg]) over the course of for 4 weeks. Sub-sets of CCl4-treated rats were also treated concurrently with rebamipide at 60 or 100 mg/kg. At 24 h after the final treatments, liver function and oxidative stress were indirectly assessed. The extent of hepatic fibrosis was evaluated using two fibrotic markers, hyaluronic acid (HA) and pro-collagen-III (Procol-III); isolated liver tissues underwent histology and were evaluated for interleukin (IL)-10 and PGE2 content. The results indicated that treatment with rebamipide significantly inhibited CCl4-induced increases in serum ALT and AST and also reduced oxidative stress induced by CCl4. Fibrotic marker assays revealed that either dose of rebamipide decreased the host levels of Procol-III and HA that had become elevated due to the CCl4. At the higher dose tested, rebamipide appeared to be able to permit the hosts to have a normal liver histology and to minimize any CCl4-induced collagen precipitation in the liver. Lastly, the use of rebamipide was seen to be associated with significant increases in liver levels of both PGE2 and the anti-inflammatory cytokine IL-10. Based on these findings, it is concluded that rebamipide can retard hepatic fibrosis induced by CCl4 and that this effect may, in part, be mediated by an induction of PGE2 and IL-10 in the liver itself.

  8. Sulforaphane inhibits IL-1β-induced proliferation of rheumatoid arthritis synovial fibroblasts and the production of MMPs, COX-2, and PGE2.

    PubMed

    Choi, Yun Jung; Lee, Won-Seok; Lee, Eun-Gyeong; Sung, Myung-Soon; Yoo, Wan-Hee

    2014-10-01

    This study was performed to define the effects of sulforaphane on interleukin-1β (IL-1β)-induced proliferation of rheumatoid arthritis synovial fibroblasts (RASFs), the expression of matrix metalloproteinases (MMPs) and cyclooxygenase (COX), and the production of prostaglandin E2 (PGE2) by RASFs. The proliferation of RASFs was evaluated with CCK-8 reagent in the presence of IL-1β with/without sulforaphane. The expression of MMPs, tissue inhibitor of metalloproteinase-1, COXs, intracellular mitogen-activated protein kinase signalings, including p-ERK, p-p38, p-JNK, and nuclear factor-kappaB (NF-kB), and the production of PGE2 were examined by Western blotting or semi-quantitative RT-PCR and ELISA. Sulforaphane inhibits unstimulated and IL-1β-induced proliferation of RASFs; the expression of MMP-1, MMP-3, and COX-2 mRNA and protein; and the PGE2 production induced by IL-1β. Sulforaphane also inhibits the phosphorylation of ERK-1/2, p-38, and JNK and activation of NF-kB by IL-1β. These results indicate that sulforaphane inhibits the proliferation of synovial fibroblasts, the expression of MMPs and COX-2, and the production of PGE2, which are involved in synovitis and destruction of RA, and suggest that sulforaphane might be a new therapeutic agent for RA.

  9. Dendritic cells issued in vitro from bone marrow produce PGE(2) that contributes to the immunomodulation induced by antigen-presenting cells.

    PubMed

    Harizi, H; Juzan, M; Grosset, C; Rashedi, M; Gualde, N

    2001-04-10

    Given that preliminary work has indicated that prostaglandins can play a role in modulating dendritic cell (DC) functions, we addressed the prostaglandin E(2) (PGE(2)) biosynthetic capacity of mouse DC produced in vitro from bone marrow cells. We observed production of significant amounts of PGE(2), which was reduced by at least 80% when cells were incubated in the presence of indomethacin, a COX-1 preferential inhibitor. Indeed, when tested by Western blot analysis with specific COX-1 and COX-2 antibodies, only COX-1 expression could be detected in the bone marrow (BM)-DC. For lipopolysaccharide (LPS)-treated BM-DC, inhibition of PGE(2) production by indomethacin or by NS-398 (a COX-2-selective inhibitor) used alone was less potent. After LPS treatment of BM-DC, COX-1 and COX-2 expression was potent, and inhibition of PGE(2) synthesis needed the presence of both indomethacin and NS-398. We also observed that exogenous PGE(2) diminished the expression of MHC class II molecules by BM-DC and that prostaglandin and indomethacin had antagonistic effects on cell proliferation during the mixed lymphocyte reaction using BM-DC as stimulatory cells. This assessment of PGE(2) suggests that endogenous PGE(2) produced by DC might play a role as an immunomodulating factor during the immune response. This hypothesis is sustained by the fact that IL-12 production by BM-DC is modulated by exogenous PGE(2) as well as endogenous prostaglandin, since either the addition of exogenous PGE(2) or the presence of LPS (which increases endogenous PGE(2) synthesis) decreases IL-12 production, while NS-398 (which decreases LPS-induced PGE(2) synthesis) increases IL-12 synthesis. Copyright 2001 Academic Press.

  10. Prostaglandin E2 mediates phosphorylation and down-regulation of the tuberous sclerosis-2 tumor suppressor (tuberin) in human endometrial adenocarcinoma cells via the Akt signaling pathway.

    PubMed

    Sales, Kurt J; Battersby, Sharon; Williams, Alistair R W; Anderson, Richard A; Jabbour, Henry N

    2004-12-01

    Prostaglandin (PG) E2 promotes tumor growth via interaction with its G protein-coupled receptors and activation of intracellular signaling. Tuberous sclerosis 2 (tuberin) is a tumor suppressor, which negatively regulates cell growth. Its phosphorylation results in its inactivation and targeted down- regulation, thus lifting the growth inhibition effects. This study investigated the expression and localization of tuberin in neoplastic and normal endometrium and the effect of PGE2 on phosphorylation of tuberin via the Akt pathway. Quantitative RT-PCR and Western blot analysis demonstrated reduced expression of tuberin in neoplastic tissue, compared with normal endometrial tissue. Tuberin expression was localized by immunohistochemistry to the glandular epithelial compartment in neoplastic and normal endometrium. We investigated the effect of PGE2 on phosphorylation of tuberin via the Akt pathway. Treatment of neoplastic and normal endometrium with 100 nm PGE2 enhanced phosphorylated tuberin immunoreactivity in the glandular epithelium. PGE2 also phosphorylated Akt and tuberin in Ishikawa endometrial adenocarcinoma cells, leading to a reduction in expression of total tuberin protein. Cotreatment of cells with wortmannin or LY294002 inhibited the PGE2-induced phosphorylation of Akt and tuberin. These data suggest that PGE2 signaling may promote endometrial tumorigenesis by inactivation of tuberin after its phosphorylation via the Akt signaling pathway.

  11. Prostaglandin E(2) and insulin-like growth factor I interact to enhance proliferation of theca externa cells from chicken prehierarchical follicles.

    PubMed

    Jia, Yudong; Lin, Jinxing; Mi, Yuling; Zhang, Caiqiao

    2013-10-01

    The interactive effect of insulin-like growth factor I (IGF-I) and prostaglandin E2 (PGE2) on the proliferation of theca externa cells (TECs) was investigated in the prehierarchical small yellow follicles of laying hens. IGF-I manifested a proliferating effect like PGE2 on TECs, but this stimulating effect was restrained by AG1024 (IGF-IR inhibitor), KP372-1 (PKB/AKT inhibitor) or NS398 (COX-2 inhibitor). AG1024, KP372-1 or NS398 abolished IGF-I-stimulated COX-2 expression and PGE2 production. Meanwhile, KP372-1, NS398 or AG1024 depressed the PGE2-stimulated expression of COX-2 and IGF-IR mRNA. Therefore, the IGF-I receptor pathway up-regulates COX-2 expression and PGE2 synthesis via PKB signaling cascade, and then PGE2 stimulates IGF-IR mRNA expression to promote TEC proliferation in an autocrine pattern. Overall, the reciprocal stimulation of intracellular PGE2 and IGF-I may enhance TEC proliferation and facilitate the development of chicken prehierarchical follicles. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. The antipyretic effect of dipyrone is unrelated to inhibition of PGE2 synthesis in the hypothalamus

    PubMed Central

    do C Malvar, David; Soares, Denis M; Fabrício, Aline SC; Kanashiro, Alexandre; Machado, Renes R; Figueiredo, Maria J; Rae, Giles A; de Souza, Glória EP

    2011-01-01

    BACKGROUND AND PURPOSE Bacterial lipopolysaccharide (LPS) induces fever through two parallel pathways; one, prostaglandin (PG)-dependent and the other, PG-independent and involving endothelin-1 (ET-1). For a better understanding of the mechanisms by which dipyrone exerts antipyresis, we have investigated its effects on fever and changes in PGE2 content in plasma, CSF and hypothalamus induced by either LPS or ET-1. EXPERIMENTAL APPROACH Rats were given (i.p.) dipyrone (120 mg·kg−1) or indomethacin (2 mg·kg−1) 30 min before injection of LPS (5 µg·kg−1, i.v.) or ET-1 (1 pmol, i.c.v.). Rectal temperature was measured by tele-thermometry. PGE2 levels were determined in the plasma, CSF and hypothalamus by elisa. KEY RESULTS LPS or ET-1 induced fever and increased CSF and hypothalamic PGE2 levels. Two hours after LPS, indomethacin reduced CSF and hypothalamic PGE2 but did not inhibit fever, while at 3 h it reduced all three parameters. Three hours after ET-1, indomethacin inhibited the increase in CSF and hypothalamic PGE2 levels but did not affect fever. Dipyrone abolished both the fever and the increased CSF PGE2 levels induced by LPS or ET-1 but did not affect the increased hypothalamic PGE2 levels. Dipyrone also reduced the increase in the venous plasma PGE2 concentration induced by LPS. CONCLUSIONS AND IMPLICATIONS These findings confirm that PGE2 does not play a relevant role in ET-1-induced fever. They also demonstrate for the first time that the antipyretic effect of dipyrone was not mechanistically linked to the inhibition of hypothalamic PGE2 synthesis. PMID:21133897

  13. Effect of oxybenzone on PGE2-production in vitro and on plaque and gingivitis in vivo.

    PubMed

    Jannesson, Lillemor; Birkhed, Dowen; Scherl, Dale; Gaffar, Abdul; Renvert, Stefan

    2004-02-01

    To study the effect of oxybenzone on prostaglandin E2 (PGE2) production in cell culture and to evaluate the effect of an oxybenzone-containing dentifrice on plaque and gingivitis in a 6-week clinical trial. Human embryo palatal mesenchyme (HEPM) cells were used for testing the inhibition of IL-1beta-stimulated PGE2-production in vitro by different concentrations of oxybenzone. For the in vivo study, a total of 66 individuals with a Quigley & Hein plaque index of at least 1.5 and an Ainamo & Bay gingival index of at least 0.2 were included in a double-blind clinical trial with two cells and a parallel design. Two compositions of fluoride dentifrice were used, one with the addition of 0.5% oxybenzone, and one without. Plaque and gingival index were obtained at three time points: (1) at baseline, (2) after 3 weeks, and (3) after 6 weeks. A dose-dependent inhibition of PGE2-production was found in the HEPM cell culture following oxybenzone exposure. In the clinical trial, a 25% reduction of gingival index was observed in the oxybenzone group (p<0.001) after 6 weeks as compared with 2% for the placebo group. These findings indicate that PGE2-production is reduced by oxybenzone in vitro and that the use of oxybenzone in a dentifrice reduces gingivitis in vivo. Copyright Blackwell Munksgaard, 2004.

  14. PGE2 contributes to TGF-β induced T regulatory cell function in human non-small cell lung cancer

    PubMed Central

    Baratelli, Felicita; Lee, Jay M; Hazra, Saswati; Lin, Ying; Walser, Tonya C; Schaue, Dorthe; Pak, Peter S; Elashoff, David; Reckamp, Karen; Zhang, Ling; Fishbein, Michael C; Sharma, Sherven; Dubinett, Steven M

    2010-01-01

    CD4+CD25bright regulatory T cells (Treg) play an important role in cancer-mediated immunosuppression. We and others have previously shown that prostaglandin E2 (PGE2) and transforming growth factor beta (TGF-β) induce CD4+CD25brightFOXP3+Treg. Based on these studies, we investigated the requirement for PGE2 in Treg induction by TGF-β. TGF-β stimulation of human CD4+ T cells induced COX-2-dependent production of PGE2. PGE2-neutralizing antibody treatment significantly reduced the suppressive function of TGF-β-induced Treg (TGF-β-Treg) in vitro. TGF-β concentration measured in the plasma of non-small cell lung cancer (NSCLC) patients directly correlated with the frequency of circulating CD4+CD25brightFOXP3+T cells. Flow cytometry analysis showed increased FOXP3 expression in circulating CD4+CD25+HLA-DR- cells of lung cancer patients compared to control subjects. Immunohistochemical analysis revealed co-expression of TGF-β, COX-2, and FOXP3 in serial sections from resected lung tumor tissues. All together these observations suggest interplay between TGF-β and COX-2 in the induction of Treg activities. Interrupting TGF-β and PGE2 signaling may be important in therapeutic interventions that aim to limit Tregfunction in lung cancer. PMID:20733946

  15. Indomethacin Inhibits Circulating PGE2 and Reverses Postexercise Suppression of Natural Killer Cell Activity

    DTIC Science & Technology

    1999-01-01

    after the oral administration of a placebo, the PG inhibitor indomethacin (75 mg/day for 5 days), or naltrexone (reported elsewhere). Circulating...which blocks PGE2 biosynthe- sis via inhibition of cyclooxygenase activity (57). Maxi- mal suppression of PG production occurs with doses between 50...and 150 mg (1). In addition to the indepen- dent effects of PGE2 on NKCA, low circulating levels of PGE2 can synergize with endogenous glucocorticoids

  16. PGE2 pulsing of murine bone marrow cells reduces migration of daughter monocytes/macrophages in vitro and in vivo

    PubMed Central

    McGonigle, Terence A.; Dwyer, Amy R.; Greenland, Eloise L.; Scott, Naomi M.; Keane, Kevin N.; Newsholme, Philip; Goodridge, Helen S.; Zon, Leonard I.; Pixley, Fiona J.; Hart, Prue H.

    2018-01-01

    Monocytes/macrophages differentiating from bone marrow (BM) cells pulsed for 2 hours at 37°C with a stabilized derivative of prostaglandin E2, 16,16-dimethyl PGE2 (dmPGE2), migrated less efficiently toward a chemoattractant than monocytes/macrophages differentiated from BM cells pulsed with vehicle. To confirm that the effect on BM cells was long lasting and to replicate human BM transplantation, chimeric mice were established with donor BM cells pulsed for 2 hours with dmPGE2 before injection into marrow-ablated congenic recipient mice. After 12 weeks, when high levels (90%) of engraftment were obtained, regenerated BM-derived monocytes/macrophages differentiating in vitro or in vivo migrated inefficiently toward the chemokines colony-stimulating factor-1 (CSF-1) and chemokine (C-C motif) ligand 2 (CCL2) or thioglycollate, respectively. Our results reveal long-lasting changes to progenitor cells of monocytes/macrophages by a 2-hour dmPGE2 pulse that, in turn, limits the migration of their daughter cells to chemoattractants and inflammatory mediators. PMID:28822771

  17. GW627368X ((N-{2-[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetyl} benzene sulphonamide): a novel, potent and selective prostanoid EP4 receptor antagonist

    PubMed Central

    Wilson, Richard J; Giblin, Gerard M P; Roomans, Susan; Rhodes, Sharron A; Cartwright, Kerri-Ann; Shield, Vanessa J; Brown, Jason; Wise, Alan; Chowdhury, Jannatara; Pritchard, Sara; Coote, Jim; Noel, Lloyd S; Kenakin, Terry; Burns-Kurtis, Cynthia L; Morrison, Valerie; Gray, David W; Giles, Heather

    2006-01-01

    N-{2-[4-(4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl]acetyl}benzene sulphonamide (GW627368X) is a novel, potent and selective competitive antagonist of prostanoid EP4 receptors with additional human TP receptor affinity. At recombinant human prostanoid EP4 receptors expressed in HEK293 cells, GW627368X produced parallel rightward shifts of PGE2 concentration–effect (E/[A]) curves resulting in an affinity (pKb) estimate of 7.9±0.4 and a Schild slpoe not significantly different from unity. The affinity was independent of the agonist used. In rings of phenylephrine precontracted piglet saphenous vein, GW627368X (30–300 nM) produced parallel rightward displacement of PGE2 E/[A] curves (pKb=9.2±0.2; slope=1). GW627368X appears to bind to human prostanoid TP receptors but not the TP receptors of other species. In human washed platelets, GW627368X (10 μM) produced 100% inhibition of U-46619 (EC100)-induced aggregation (approximate pA2 ∼7.0). However, in rings of rabbit and piglet saphenous vein and of guinea-pig aorta GW627368X (10 μM) did not displace U-46619 E/[A] curves indicating an affinity of <5.0 for rabbit and guinea-pig prostanoid TP receptors. In functional assays GW627368X is devoid of both agonism and antagonist affinity for prostanoid CRTH2, EP2, EP3, IP and FP receptors. At prostanoid EP1 receptors, GW627368X was an antagonist with a pA2 of 6.0, and at prostanoid IP receptors the compound increased the maximum effect of iloprost by 55%. At rabbit prostanoid EP2 receptors the pA2 of GW627368X was <5.0. In competition radioligand bioassays, GW627368X had affinity for human prostanoid EP4 and TP receptors (pKi=7.0±0.2 (n=10) and 6.8 (n=2), respectively). Affinity for all other human prostanoid receptors was <5.3. GW627368X will be a valuable tool to explore the role of the prostanoid EP4 receptor in many physiological and pathological settings. PMID:16604093

  18. The whipworm (Trichuris suis) secretes prostaglandin E2 to suppress proinflammatory properties in human dendritic cells.

    PubMed

    Laan, Lisa C; Williams, Andrew R; Stavenhagen, Kathrin; Giera, Martin; Kooij, Gijs; Vlasakov, Iliyan; Kalay, Hakan; Kringel, Helene; Nejsum, Peter; Thamsborg, Stig M; Wuhrer, Manfred; Dijkstra, Christine D; Cummings, Richard D; van Die, Irma

    2017-02-01

    Clinical trials have shown that administration of the nematode Trichuris suis can be beneficial in treating various immune disorders. To provide insight into the mechanisms by which this worm suppresses inflammatory responses, an active component was purified from T. suis soluble products (TsSPs) that suppress---- TNF and IL-12 secretion from LPS-activated human dendritic cells (DCs). Analysis by liquid chromatography tandem mass spectrometry identified this compound as prostaglandin (PG)E2. The purified compound showed similar properties compared with TsSPs and commercial PGE2 in modulating LPS-induced expression of many cytokines and chemokines and in modulating Rab7B and P2RX7 expression in human DCs. Furthermore, the TsSP-induced reduction of TNF secretion from DCs is reversed by receptor antagonists for EP2 and EP4, indicating PGE2 action. T. suis secretes extremely high amounts of PGE2 (45-90 ng/mg protein) within their excretory/secretory products but few related lipid mediators as established by metabololipidomic analysis. Culture of T. suis with several cyclooxygenase (COX) inhibitors that inhibit mammalian prostaglandin synthesis affected the worm's motility but did not inhibit PGE2 secretion, suggesting that the worms can synthesize PGE2 via a COX-independent pathway. We conclude that T. suis secretes PGE2 to suppress proinflammatory responses in human DCs, thereby modulating the host's immune response.-Laan, L. C., Williams, A. R., Stavenhagen, K., Giera, M., Kooij, G., Vlasakov, I., Kalay, H., Kringel, H., Nejsum, P., Thamsborg, S. M., Wuhrer, M., Dijkstra, C. D., Cummings, R. D., van Die, I. The whipworm (Trichuris suis) secretes prostaglandin E2 to suppress proinflammatory properties in human dendritic cells. © FASEB.

  19. Vaginal Lactoferrin Modulates PGE2, MMP-9, MMP-2, and TIMP-1 Amniotic Fluid Concentrations

    PubMed Central

    Maritati, Martina; Gonelli, Arianna; Greco, Pantaleo

    2016-01-01

    Inflammation plays an important role in pregnancy, and cytokine and matrix metalloproteases (MMPs) imbalance has been associated with premature rupture of membranes and increased risk of preterm delivery. Previous studies have demonstrated that lactoferrin (LF), an iron-binding protein with anti-inflammatory properties, is able to decrease amniotic fluid (AF) levels of IL-6. Therefore, we aimed to evaluate the effect of vaginal LF administration on amniotic fluid PGE2 level and MMP-TIMP system in women undergoing genetic amniocentesis. One hundred and eleven women were randomly divided into controls (n = 57) or treated with LF 4 hours before amniocentesis (n = 54). Amniotic fluid PGE2, active MMP-9 and MMP-2, and TIMP-1 and TIMP-2 concentrations were determined by commercially available assays and the values were normalized by AF creatinine concentration. PGE2, active MMP-9, and its inhibitor TIMP-1 were lower in LF-treated group than in controls (p < 0.01, p < 0.005, and p < 0.001, resp.). Conversely, active MMP-2 (p < 0.0001) and MMP-2/TIMP-2 molar ratio (p < 0.001) were increased, whilst TIMP-2 was unchanged. Our data suggest that LF administration is able to modulate the inflammatory response following amniocentesis, which may counteract cytokine and prostanoid imbalance that leads to abortion. This trial is registered with Clinical Trial number NCT02695563. PMID:27872513

  20. Prostaglandin E2 acts via bone marrow macrophages to block PTH-stimulated osteoblast differentiation in vitro

    PubMed Central

    Choudhary, Shilpa; Blackwell, Katherine; Voznesensky, Olga; Roy, Abhijit Deb; Pilbeam, Carol

    2014-01-01

    Intermittent PTH is the major anabolic therapy for osteoporosis while continuous PTH causes bone loss. PTH acts on the osteoblast (OB) lineage to regulate bone resorption and formation. PTH also induces cyclooxygenase-2 (COX-2), producing prostaglandin E2 (PGE2) that can act on both OBs and osteoclasts (OCs). Because intermittent PTH is more anabolic in Cox-2 knockout (KO) than wild type (WT) mice, we hypothesized COX-2 might contribute to the effects of continuous PTH by suppressing PTH-stimulated differentiation of mesenchymal stem cells into OBs. We compared effects of continuous PTH on bone marrow stromal cells (BMSCs) and primary OBs (POBs) from Cox-2 KO mice, mice with deletion of PGE2 receptors (Ptger4 and Ptger2 KO mice), and WT controls. PTH increased OB differentiation in BMSCs only in the absence of COX-2 expression or activity. In the absence of COX-2, PTH stimulated differentiation if added during the first week of culture. In Cox-2 KO BMSCs, PTH-stimulated differentiation was prevented by adding PGE2 to cultures. Co-culture of POBs with M-CSF-expanded bone marrow macrophages (BMMs) showed that the inhibition of PTH-stimulated OB differentiation required not only COX-2 or PGE2 but also BMMs. Sufficient PGE2 to mediate the inhibitory effect was made by either WT POBs or WT BMMs. The inhibitory effect mediated by COX-2/PGE2 was transferred by conditioned media from RANKL-treated BMMs and could be blocked by osteoprotegerin, which interferes with RANKL binding to its receptor on OC lineage cells. Deletion of Ptger4, but not Ptger2, in BMMs prevented the inhibition of PTH-stimulated OB differentiation. As expected, PGE2 also stimulated OB differentiation, but when given in combination with PTH, the stimulatory effects of both were abrogated. These data suggest that PGE2, acting via EP4R on BMMs committed to the OC lineage, stimulated secretion of a factor or factors that acted to suppress PTH-stimulated OB differentiation. This suppression of OB

  1. Celecoxib can suppress expression of genes associated with PGE2 pathway in chondrocytes under inflammatory conditions.

    PubMed

    Sun, Tian-Wen; Wu, Zhi-Hong; Weng, Xi-Sheng

    2015-01-01

    This study aimed to investigate the effect of a selective cyclooxygenase-2 (COX-2) inhibitor (celecoxib) on the expression of arachidonate-associated inflammatory genes in cultured human normal chondrocytes. Normal chondrocytes were obtained from the cartilage of three different amputated patients without osteoarthritis (OA). Affymetrix Human microarray was used to assess the alterations in gene expression in three groups of cells: untreated cells (negative control group), cells treated with interleukin-1β (IL-1β) (positive control group), and cells treated with IL-1β and celecoxib. The patterns of up-regulation and down-regulation of gene expression were further validated by real-time PCR. A total of 1091 up-regulated genes and 1252 down-regulated genes were identified in the positive control group compared with the negative control group. Among them, PTGS2, ADAMTS5, PTGER2, mPTGES and PTGER4 are known to be involved in chondrocyte inflammation, while VEGFA, BCL2, TRAF1, CYR61, BMP6, DAPK1, DUSP7, IL1RN, MMP13 and TNFSF10 were reported being associated with cytokine and chemokine signaling. 189 up-regulated genes and 177 down-regulated genes were identified in the positive control group compared with intervention group. PTGS1, PTGS2, ADAMTS5, PTGER2, mPTGES and PTGER4 were among the genes down-regulated upon the treatment with celecoxib. Our results demonstrated that the OA chondrocytes are the site of active eicosanoid production. IL-1β can activate inflammation in chondrocytes and trigger the production of various proteins involved in cyclooxygenase pathway. The expression of genes corresponding to these proteins can be down-regulated by celecoxib. The findings indicate that the therapy with prostaglandin E2 (PGE2)-blocking agents may decrease the PGE2 production not only by direct inhibition of COX-2 activity, but also by down-regulating the expression of genes encoding for COX-2, microsomal prostaglandin-endoperoxide synthase 1 (mPGES-1) and prostaglandin

  2. Human umbilical cord mesenchymal stem cells hUC-MSCs exert immunosuppressive activities through a PGE2-dependent mechanism.

    PubMed

    Chen, Ke; Wang, Ding; Du, Wei Ting; Han, Zhi-Bo; Ren, He; Chi, Ying; Yang, Shao Guang; Zhu, Delin; Bayard, Francis; Han, Zhong Chao

    2010-06-01

    Human umbilical-cord-derived mesenchymal stem cells (hUC-MSCs) constitute an attractive alternative to bone-marrow-derived MSCs for potential clinical applications because of easy preparation and lower risk of viral contamination. In this study, both proliferation of human peripheral blood mononuclear cells (hPBMCs) and their IFN-gamma production in response to mitogenic or allogeneic stimulus were effectively inhibited by hUC-MSCs. Co-culture experiments in transwell systems indicated that the suppression was largely mediated by soluble factor(s). Blocking experiments identified prostaglandin E(2) (PGE(2)) as the major factor, because inhibition of PGE(2) synthesis almost completely mitigated the immunosuppressive effects, whereas neutralization of TGF-beta, IDO, and NO activities had little effects. Moreover, the inflammatory cytokines, IFN-gamma and IL-1beta, produced by hPBMCs upon activation notably upregulated the expression of cyclooxygenase-2 (COX-2) and the production of PGE(2) by hUC-MSCs. In conclusion, our data have demonstrated for the first time the PGE(2)-mediated mechanism by which hUC-MSCs exert their immunomodulatory effects. Copyright 2010 Elsevier Inc. All rights reserved.

  3. Role of the Prostaglandin E2 EP1 Receptor in Traumatic Brain Injury

    PubMed Central

    Glushakov, Alexander V.; Fazal, Jawad A.; Narumiya, Shuh; Doré, Sylvain

    2014-01-01

    Brain injuries promote upregulation of so-called proinflammatory prostaglandins, notably prostaglandin E2 (PGE2), leading to overactivation of a class of its cognate G-protein-coupled receptors, including EP1, which is considered a promising target for treatment of ischemic stroke. However, the role of the EP1 receptor is complex and depends on the type of brain injury. This study is focused on the investigation of the role of the EP1 receptor in a controlled cortical impact (CCI) model, a preclinical model of traumatic brain injury (TBI). The therapeutic effects of post-treatments with a widely studied EP1 receptor antagonist, SC-51089, were examined in wildtype and EP1 receptor knockout C57BL/6 mice. Neurological deficit scores (NDS) were assessed 24 and 48 h following CCI or sham surgery, and brain immunohistochemical pathology was assessed 48 h after surgery. In wildtype mice, CCI resulted in an obvious cortical lesion and localized hippocampal edema with an associated significant increase in NDS compared to sham-operated animals. Post-treatments with the selective EP1 receptor antagonist SC-51089 or genetic knockout of EP1 receptor had no significant effects on cortical lesions and hippocampal swelling or on the NDS 24 and 48 h after CCI. Immunohistochemistry studies revealed CCI-induced gliosis and microglial activation in selected ipsilateral brain regions that were not affected by SC-51089 or in the EP1 receptor-deleted mice. This study provides further clarification on the respective contribution of the EP1 receptor in TBI and suggests that, under this experimental paradigm, the EP1 receptor would have limited effects in modulating acute neurological and anatomical pathologies following contusive brain trauma. Findings from this protocol, in combination with previous studies demonstrating differential roles of EP1 receptor in ischemic, neurotoxic, and hemorrhagic conditions, provide scientific background and further clarification of potential therapeutic

  4. Sulfonamide derivatives of styrylheterocycles as a potent inhibitor of COX-2-mediated prostaglandin E2 production.

    PubMed

    Lim, Chaemin; Lee, Minhee; Park, Eun-Jung; Cho, Ran; Park, Hyen-Joo; Lee, Seong Jin; Cho, Heeyeong; Lee, Sang Kook; Kim, Sanghee

    2010-12-01

    The overproduction of prostaglandin E(2) (PGE(2)) plays an important role in a variety of pathophysiological processes including inflammation and carcinogenesis. Therefore, the modulation of PGE(2) production is a promising target in the design of chemotherapeutic agents. In the present study, the inhibitory effects of a series of styrylheterocycles having either a p-SO(2)NH(2) or p-SO(2)Me group on the production of cyclooxygenase-2-mediated PGE(2) were evaluated in lipopolysaccharide-stimulated RAW264.7 murine macrophages. Among the series of styrylheterocycle derivatives, (E)-4-(2-(thiophen-3-yl)vinyl)benzenesulfonamide exhibited a potent inhibitory activity, with an IC(50) value of 0.013 μM. The inhibitory activity against the overproduction of PGE(2) by the active compound was found to be due in part to the suppression of COX-2 mRNA expression. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Accurate quantification of PGE2 in the polyposis in rat colon (Pirc) model by surrogate analyte-based UPLC-MS/MS.

    PubMed

    Yun, Changhong; Dashwood, Wan-Mohaiza; Kwong, Lawrence N; Gao, Song; Yin, Taijun; Ling, Qinglan; Singh, Rashim; Dashwood, Roderick H; Hu, Ming

    2018-01-30

    An accurate and reliable UPLC-MS/MS method is reported for the quantification of endogenous Prostaglandin E2 (PGE 2 ) in rat colonic mucosa and polyps. This method adopted the "surrogate analyte plus authentic bio-matrix" approach, using two different stable isotopic labeled analogs - PGE 2 -d9 as the surrogate analyte and PGE 2 -d4 as the internal standard. A quantitative standard curve was constructed with the surrogate analyte in colonic mucosa homogenate, and the method was successfully validated with the authentic bio-matrix. Concentrations of endogenous PGE 2 in both normal and inflammatory tissue homogenates were back-calculated based on the regression equation. Because of no endogenous interference on the surrogate analyte determination, the specificity was particularly good. By using authentic bio-matrix for validation, the matrix effect and exaction recovery are identically same for the quantitative standard curve and actual samples - this notably increased the assay accuracy. The method is easy, fast, robust and reliable for colon PGE 2 determination. This "surrogate analyte" approach was applied to measure the Pirc (an Apc-mutant rat kindred that models human FAP) mucosa and polyps PGE 2 , one of the strong biomarkers of colorectal cancer. A similar concept could be applied to endogenous biomarkers in other tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A prostaglandin E2 receptor antagonist prevents pregnancies during a preclinical contraceptive trial with female macaques.

    PubMed

    Peluffo, M C; Stanley, J; Braeuer, N; Rotgeri, A; Fritzemeier, K-H; Fuhrmann, U; Buchmann, B; Adevai, T; Murphy, M J; Zelinski, M B; Lindenthal, B; Hennebold, J D; Stouffer, R L

    2014-07-01

    Can administration of a prostaglandin (PG) E2 receptor 2 (PTGER2) antagonist prevent pregnancy in adult female monkeys by blocking periovulatory events in the follicle without altering menstrual cyclicity or general health? This is the first study to demonstrate that a PTGER2 antagonist can serve as an effective non-hormonal contraceptive in primates. The requirement for PGE2 in ovulation and the release of an oocyte surrounded by expanded cumulus cells (cumulus-oocyte expansion; C-OE) was established through the generation of PTGS2 and PTGER2 null-mutant mice. A critical role for PGE2 in primate ovulation is supported by evidence that intrafollicular injection of indomethacin in rhesus monkeys suppressed follicle rupture, whereas co-injection of PGE2 with indomethacin resulted in ovulation. First, controlled ovulation protocols were performed in adult, female rhesus monkeys to analyze the mRNA levels for genes encoding PGE2 synthesis and signaling components in the naturally selected pre-ovulatory follicle at different times after the ovulatory hCG stimulus (0, 12, 24, 36 h pre-ovulation; 36 h post-ovulation, n = 3-4/time point). Second, controlled ovarian stimulation cycles were utilized to obtain multiple cumulus-oocyte complexes (COCs) from rhesus monkeys to evaluate the role of PGE2 in C-OE in vitro (n = 3-4 animals/treatment; ≥3 COCs/animal/treatment). Third, adult cycling female cynomolgus macaques were randomly assigned (n = 10/group) to vehicle (control) or PTGER2 antagonist (BAY06) groups to perform a contraceptive trial. After the first treatment cycle, a male of proven fertility was introduced into each group and they remained housed together for the duration of the 5-month contraceptive trial that was followed by a post-treatment reversibility trial. Quantitative real-time PCR, COC culture and expansion, immunofluorescence/confocal microscopy, enzyme immunoassay, contraceptive trial, ultrasonography, complete blood counts, serum biochemistry tests

  7. Synthesis and PGE(2) production inhibition of 1H-furan-2,5-dione and 1H-pyrrole-2,5-dione derivatives.

    PubMed

    Moon, Jong Taik; Jeon, Ji Young; Park, Hang Ah; Noh, Young-Soo; Lee, Kyung-Tae; Kim, Jungahn; Choo, Dong Joon; Lee, Jae Yeol

    2010-01-15

    3,4-Diphenyl-substituted 1H-furan-2,5-dione and 1H-pyrrole-2,5-dione derivatives were synthesized and evaluated for the inhibitory activities on LPS-induced PGE(2) production in RAW 264.7 macrophage cells. Both 1H-furan-2,5-dione and 1H-pyrrole-2,5-dione rings as main scaffolds were easily obtained using one of three synthetic methods. Among the compounds investigated, 1H-3-(4-sulfamoylphenyl)-4-phenyl-pyrrole-2,5-dione (6l) showed a strong inhibitory activity (IC(50)=0.61microM) of PGE(2) production. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Orexin neurons are indispensable for prostaglandin E2-induced fever and defence against environmental cooling in mice

    PubMed Central

    Takahashi, Yoshiko; Zhang, Wei; Sameshima, Kohei; Kuroki, Chiharu; Matsumoto, Ami; Sunanaga, Jinko; Kono, Yu; Sakurai, Takeshi; Kanmura, Yuichi; Kuwaki, Tomoyuki

    2013-01-01

    We recently showed using prepro-orexin knockout (ORX-KO) mice and orexin neuron-ablated (ORX-AB) mice that orexin neurons in the hypothalamus, but not orexin peptides per se, are indispensable for stress-induced thermogenesis. To examine whether orexin neurons are more generally involved in central thermoregulatory mechanisms, we applied other forms of thermogenic perturbations, including brain prostaglandin E2 (PGE2) injections which mimic inflammatory fever and environmental cold exposure, to ORX-KO mice, ORX-AB mice and their wild-type (WT) litter mates. ORX-AB mice, but not ORX-KO mice, exhibited a blunted PGE2-induced fever and intolerance to cold (5°C) exposure, and these findings were similar to the results previously obtained with stress-induced thermogenesis. PGE2-induced shivering was also attenuated in ORX-AB mice. Both mutants responded similarly to environmental heating (39°C). In WT and ORX-KO mice, the administration of PGE2 and cold exposure activated orexin neurons, as revealed by increased levels of expression of c-fos. Injection of retrograde tracer into the medullary raphe nucleus revealed direct and indirect projection from the orexin neurons, of which the latter seemed to be preserved in the ORX-AB mice. In addition, we found that glutamate receptor antagonists (d-(–)-2-amino-5-phosphonopentanoic acid and 6-cyano-7-nitroquinoxaline-2,3-dione) but not orexin receptor antagonists (SB334867 and OX2 29) successfully inhibited PGE2-induced fever in WT mice. These results suggest that orexin neurons are important in general thermogenic processes, and their importance is not restricted to stress-induced thermogenesis. In addition, these results indicate the possible involvement of glutamate in orexin neurons implicated in PGE2-induced fever. PMID:23959674

  9. Orexin neurons are indispensable for prostaglandin E2-induced fever and defence against environmental cooling in mice.

    PubMed

    Takahashi, Yoshiko; Zhang, Wei; Sameshima, Kohei; Kuroki, Chiharu; Matsumoto, Ami; Sunanaga, Jinko; Kono, Yu; Sakurai, Takeshi; Kanmura, Yuichi; Kuwaki, Tomoyuki

    2013-11-15

    We recently showed using prepro-orexin knockout (ORX-KO) mice and orexin neuron-ablated (ORX-AB) mice that orexin neurons in the hypothalamus, but not orexin peptides per se, are indispensable for stress-induced thermogenesis. To examine whether orexin neurons are more generally involved in central thermoregulatory mechanisms, we applied other forms of thermogenic perturbations, including brain prostaglandin E2 (PGE2) injections which mimic inflammatory fever and environmental cold exposure, to ORX-KO mice, ORX-AB mice and their wild-type (WT) litter mates. ORX-AB mice, but not ORX-KO mice, exhibited a blunted PGE2-induced fever and intolerance to cold (5°C) exposure, and these findings were similar to the results previously obtained with stress-induced thermogenesis. PGE2-induced shivering was also attenuated in ORX-AB mice. Both mutants responded similarly to environmental heating (39°C). In WT and ORX-KO mice, the administration of PGE2 and cold exposure activated orexin neurons, as revealed by increased levels of expression of c-fos. Injection of retrograde tracer into the medullary raphe nucleus revealed direct and indirect projection from the orexin neurons, of which the latter seemed to be preserved in the ORX-AB mice. In addition, we found that glutamate receptor antagonists (D-(-)-2-amino-5-phosphonopentanoic acid and 6-cyano-7-nitroquinoxaline-2,3-dione) but not orexin receptor antagonists (SB334867 and OX2 29) successfully inhibited PGE2-induced fever in WT mice. These results suggest that orexin neurons are important in general thermogenic processes, and their importance is not restricted to stress-induced thermogenesis. In addition, these results indicate the possible involvement of glutamate in orexin neurons implicated in PGE2-induced fever.

  10. Contribution of reactive oxygen species to migration/invasion of human glioblastoma cells U87 via ERK-dependent COX-2/PGE(2) activation.

    PubMed

    Chiu, Wen-Ta; Shen, Shing-Chuan; Chow, Jyh-Ming; Lin, Cheng-Wei; Shia, Ling-Tin; Chen, Yen-Chou

    2010-01-01

    In the presence of 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulation, an increase in the migration/invasion of U87 glioblastoma cells was detected by a wound healing assay, transwell analysis, and spheroid formation assay by inducing matrix metalloproteinase-9 (MMP-9) enzyme activity via a gelatin zymographic analysis. A dose- and time-dependent increase in cyclooxygenase-2 (COX-2) gene expression with elevated prostaglandin E(2) (PGE(2)) production was identified in TPA- but not in 4alpha-TPA (a respective inactive compound)-treated U87 cells TPA-induced migration/invasion was significantly blocked by adding the COX-2-specific inhibitor, NS398, through a reduction in PGE(2) production. Data from the pharmacological studies using specific chemical inhibitors showed that activation of protein kinase C (PKC) and extracellular signal-regulated kinases (ERKs) was involved in TPA-induced migration/invasion, COX-2 protein expression, and MMP-9 activation. Stimulation of intracellular peroxide production by TPA was detected by a DCHF-DA assay, and the addition of superoxide dismutase (SOD) or tempol significantly inhibited TPA-induced migration/invasion and COX-2 protein expression accompanied by a decrease in peroxide production. An increase in NADPH oxidase activity by TPA was examined, and TPA-induced migration/invasion was blocked by adding DPI, an NADPH oxidase inhibitor. Additionally, the natural flavonoids quercetin (QE), baicalein (BE), and myricetin (ME) effectively blocked TPA-induced migration/invasion while simultaneously inhibiting COX-2/PGE(2) production, MMP-9 enzyme activity, and peroxide production in U87 cells. The contribution of ROS production to the migration/invasion of U87 glioblastoma cells via ERK-activated COX-2/PGE(2) and MMP-9 induction was first investigated here, and agents such as QE, BE, and ME with the ability to block these events possess the potential to be developed for use against migration/invasion by glioblastomas.

  11. Roles of prostaglandin E2 in the cochlea.

    PubMed

    Nakagawa, Takayuki

    2011-06-01

    Prostaglandins are one of the major groups of chemical mediators in the mammalian body. Among prostaglandins, prostaglandin E2 (PGE2) is the most abundant prostanoid in humans and involved in regulating many different fundamental biological functions. PGE2 signaling is mediated by four distinct E-prostanoid receptors (EPs) namely EP1-4. Recently, accumulating evidence indicates critical, but complex roles of EP signaling in the pathogenesis of neuronal diseases depending on the context of neuronal injury. Four distinct EPs are expressed in the stria vascularis, spiral ligament, spiral ganglion and organ of Corti, indicating an involvement of EP signaling in the cochlear function. Activation of EP4 in cochleae significantly attenuates noise-induced damage in cochleae, and activation of EP2 or EP4 induces the formation of vascular endothelial growth factor in cochleae. These findings strongly suggest that individual EP signaling may be involved in the maintenance of the cochlear sensory system similarly to the central nervous system. This review highlights recent findings on EP signaling in the central nervous system, and presents its possible roles in regulation of blood flow, protection of sensory cells and immune responses in cochleae. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Functional reconstitution of prostaglandin E receptor from bovine adrenal medulla with guanine nucleotide binding proteins

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Negishi, M.; Ito, S.; Yokohama, H.

    1988-05-15

    Prostaglandin E/sub 2/ (PEG/sub 2/) was found to bind specifically to a 100,000 x g pellet prepared from bovine adrenal medulla. The PGE receptor was associated with a GTP-binding protein (G-protein) and could be covalently cross-linked with this G-protein by dithiobis(succinimidyl propionate) in the 100,000 x g pellet. In order to characterize the G-protein associated with the PGE receptor and reconstitute these proteins in phospholipid vesicles, the authors purified the G-protein to apparent homogeneity from the 100,000 x g pellet. The G-protein served as a substrate of pertussis toxin but differed in its ..cap alpha.. subunit from two known pertussismore » toxin substrate G-proteins (G/sub i/ and G/sub 0/) purified from bovine brain. The molecular weight of the ..cap alpha.. subunit was 40,000, which is between those of G/sub i/ and G/sub 0/. The purified protein was also distinguished immunologically from G/sub i/ and G/sub 0/ and was referred to as G/sub am/. Reconstitution of the PGE receptor with pure C/sub am/, G/sub i/, or G/sub 0/ in phospholipid vesicles resulted in a remarkable restoration of (/sup 3/H)PGE/sub 2/ binding activity in a GTP-dependent manner. The efficiency of these three G-proteins in this capacity was roughly equal. When pertussis toxin- or N-ethylmaleimide-treated G-proteins, instead of the native ones, were reconstituted into vesicles, the restoration of binding activity was no longer observed. These results indicate that the PGE receptor can couple functionally with G/sub am/, G/sub i/, or G/sub 0/ in phospholipid vesicles and suggest that G/sub am/ may be involved in signal transduction of the PGE receptor in bovine adrenal medulla.« less

  13. Prostaglandin E2 regulates melanocyte dendrite formation through activation of PKCζ

    PubMed Central

    Scott, Glynis; Fricke, Alex; Fender, Anne; McClelland, Lindy; Jacobs, Stacey

    2007-01-01

    Prostaglandins are lipid signaling intermediates released by keratinocytes in response to ultraviolet irradiation (UVR) in the skin. The main prostaglandin released following UVR is PGE2, a ligand for 4 related G-protein coupled receptors (EP1, EP2, EP3 and EP4). Our previous work established that PGE2 stimulates melanocyte dendrite formation through activation of the EP1 and EP3 receptors. The purpose of the present report is to define the signaling intermediates involved in EP1 and EP3-dependent dendrite formation in human melanocytes. We recently showed that activation of the atypical PKCζ isoform stimulates melanocyte dendricity in response to treatment with lysophosphatidylcholine. We therefore examined the potential contribution of PKCζ activation on EP1 and EP3-dependent dendrite formation in melanocytes. Stimulation of the EP1 and EP3 receptors by selective agonists activated PKCζ, and inhibition of PKCζ activation abrogated EP1 and EP3-receptor mediated melanocyte dendricity. Because of the importance of Rho-GTP binding proteins in the regulation of melanocyte dendricity, we also examined the effect of EP1 and EP3 receptor activation on Rac and Rho activity. Neither Rac nor Rho was activated upon treatment with EP1,3-receptor agonists. We show that melanocytes express only the EP3A1 isoform, but not the EP3B receptor isoform, previously associated with Rho activation, consistent with a lack of Rho stimulation by EP3 agonists. Our data suggest that PKCζ activation plays a predominant role in regulation of PGE2-dependent melanocyte dendricity. PMID:17850789

  14. [Labor induction with extra-amnial administration of PGE2 vaginal tablets].

    PubMed

    Roztocil, A; Koudelka, M; Jelínek, J; Miklica, J; Pilka, L

    1996-08-01

    During the period between Jan. 1 1992 and Dec. 31, 1995 at the Second Department of Gynaecology and Obstetrics in Brno labour was induced in 1159 patients by extraamnial fractionated administration of PGE2 vaginal tablets. After assessment of the indication and the baseline examination (NST, amnioscopy, US biometry and cervical score) according to the CS to the patient the first dose of PGE2 was administered into the extraamnial space beyond the inner os uteri (CS 5-8:1.0 mg PGE2, CS > 8 : 0.5 mg PGE2). After two hours the patient was examined again and if regular uterine contractions had started or the finding on the os uteri was larger than 2 cm, the amniotic sac was disrupted. If not, another dose was administered. After two hours the patient was re-examined and if the os was larger than 2 cm, and there were regular uterine contractions, the amniotic sac was disrupted. If the changes did not take place, the induction was considered a failure. there were 1007 successful inductions (95.5%), the mean period from the onset of induction to the onset of uterine contractions was < 120 mins-269 (24.6%), 120-180 mins.: 501 (45.9%) and > 180 mins.: 322 (29.5%). The mean period of the first stage of labour was 228 mins., stage II 10 mins., stage III 8 mins. Five times uterine hypertonus was recorded and a blood loss greater than 500 ml occurred in four patients. Forty-nine Caesarean sections were made (4.2%) and 51 (4.4%) forceps deliveries. The rate of epidural analgesia was 27 (2.3%). Revision of the uterine cavity was made in 39 patients (3.4%) and manual lysis of the placenta in 30 (2.6%). The Apgar score was inferior to 6 in 10 neonates (0.9%). The protocol of induction of labour described by the authors is effective and associated with a minimum of side-effects, safe for the mother and foetus, well tolerated by patients and cost-effective.

  15. Tromboxane B2 inhibits the pulmonary inactivation of prostaglandin E2 in the dog.

    PubMed Central

    Fitzpatrick, T. M.; Friedman, L. S.; Kot, P. A.; Ramwell, P. W.

    1980-01-01

    1 The systemic vasodepressor response to intravenously administered prostaglandin E2 (PGE2, 0.3, 1.0 and 3.0 micrograms/kg) is potentiated during intravenous infusion of thromboxane B2 (TXB2, 1.0 micrograms kg-1 min-1) in the anaesthetized dog. 2 The augmented haemodynamic response returns toward control values following cessation of the TXB2 infusion. 3 The systemic haemodynamic responses to intra-arterially administered PGE2, PGF2 alpha and PGI2 as well as intravenously administered PGF2 alpha and PGI2 are not altered by TXB2 infusion. 4. This study suggests that TXB2 inhibits the pulmonary inactivation of PGE2. 5 Arachidonic acid metabolites may interact, producing haemodynamic responses differing from their individual effects. PMID:7000216

  16. PGE(2) activation of apical membrane Cl(-) channels in A6 epithelia: impedance analysis.

    PubMed Central

    Păunescu, T G; Helman, S I

    2001-01-01

    Measurements of transepithelial electrical impedance of continuously short-circuited A6 epithelia were made at audio frequencies (0.244 Hz to 10.45 kHz) to investigate the time course and extent to which prostaglandin E(2) (PGE(2)) modulates Cl(-) transport and apical membrane capacitance in this cell-cultured model epithelium. Apical and basolateral membrane resistances were determined by nonlinear curve-fitting of the impedance vectors at relatively low frequencies (<50 Hz) to equations (Păunescu, T. G., and S. I. Helman. 2001. Biophys. J. 81:838--851) where depressed Nyquist impedance semicircles were characteristic of the membrane impedances under control Na(+)-transporting and amiloride-inhibited conditions. In all tissues (control, amiloride-blocked, and amiloride-blocked and furosemide-pretreated), PGE(2) caused relatively small (< approximately 3 microA/cm(2)) and rapid (<60 s) maximal increase of chloride current due to activation of a rather large increase of apical membrane conductance that preceded significant activation of Na(+) transport through amiloride-sensitive epithelial Na(+) channels (ENaCs). Apical membrane capacitance was frequency-dependent with a Cole-Cole dielectric dispersion whose relaxation frequency was near 150 Hz. Analysis of the time-dependent changes of the complex frequency-dependent equivalent capacitance of the cells at frequencies >1.5 kHz revealed that the mean 9.8% increase of capacitance caused by PGE(2) was not correlated in time with activation of chloride conductance, but rather correlated with activation of apical membrane Na(+) transport. PMID:11463630

  17. Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Dahiya, R.; Hughes-Fulford, M.

    1997-01-01

    Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

  18. JP-8 jet fuel exposure rapidly induces high levels of IL-10 and PGE2 secretion and is correlated with loss of immune function.

    PubMed

    Harris, David T; Sakiestewa, Debbie; Titone, Dominic; Witten, Mark

    2007-05-01

    The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has demonstrated that JP-8 exposure is immunosuppressive. In the present study, the potential mechanisms for the effects of JP-8 exposure on the immune system were investigated. Exposure of mice to JP-8 for 1 h/day resulted in immediate secretion of two immunosuppressive agents; namely, interleukin-10 (IL-10) and prostaglandin E2 (PGE2). JP-8 exposure rapidly induced a persistently high level of serum IL-10 and PGE2 at an exposure concentration of 1000 mg/m3. IL-10 levels peaked at 2 h post-JP-8 exposure and then stabilized at significantly elevated serum levels, while PGE2 levels peaked after 2-3 days of exposure and then stabilized. Elevated IL-10 and PGE2 levels may at least partially explain the effects of JP-8 exposure on immune function. Elevated IL-10 and PGE2 levels, however, cannot explain all of the effects due to JP-8 exposure (e.g., decreased organ weights and decreased viable immune cells), as treatment with a PGE2 inhibitor did not completely reverse the immunosuppressive effects of jet fuel exposure. Thus, low concentration JP-8 jet fuel exposures have significant effects on the immune system, which can be partially explained by the secretion of immunosuppressive modulators, which are cumulative over time.

  19. Dual inhibition of nitric oxide and prostaglandin E2 production by polysubstituted 2-aminopyrimidines.

    PubMed

    Zídek, Zdeněk; Kverka, Miloslav; Dusilová, Adéla; Kmoníčková, Eva; Jansa, Petr

    2016-07-01

    The present in vitro experiments demonstrate inhibitory effects of polysubstituted 2-aminopyrimidines on high output production of nitric oxide (NO) and prostaglandin E2 (PGE2) stimulated by interferon-γ and lipopolysaccharide (LPS) in peritoneal macrophages of mouse and rat origin. PGE2 production was inhibited also in LPS-activated human peripheral blood mononuclear cells. A tight dependence of the suppressive activities on chemical structure of pyrimidines was observed. Derivatives containing hydroxyl groups at the C-4 and C-6 positions of pyrimidine ring were devoid of any influence on NO and PGE2. Remarkable inhibitory potential was acquired by the replacement of hydroxyl groups with chlorine, the 4,6-dichloro derivatives being more effective than the monochloro analogues. The effects were further intensified by modification of the amino group at the C-2 position, changing it to the (N,N-dimethylamino)methyleneamino or the formamido ones. There was no substantial difference in the expression of NO-inhibitory effects among derivatives containing distinct types of substituents at the C-5 position (hydrogen, methyl, ethyl, propyl, butyl, phenyl, and benzyl). In contrast to NO, larger substituents then methyl were required to inhibit PGE2 production. Overall, no significant correlation between the extent of NO and PGE2 suppression was observed. The IC50s of derivatives with the strongest effects on both NO and PGE2 were within the range of 2-10 μM. Their NO-inhibitory potential of pyrimidines was stronger than that of non-steroidal anti-inflammatory drugs (NSAIDs) aspirin and indomethacin. The PGE2-inhibitory effectiveness of pyrimidines was about the same as that of aspirin, but weaker as compared to indomethacin. The NO- and PGE2-inhibitory activity of tested pyrimidines has been found associated with decreased expression of iNOS mRNA and COX-2 mRNA, respectively, and with post-translation interactions. Selected NO-/PGE2-inhibitory derivatives decreased

  20. Regulation of ocular surface inflammation by prostaglandin E receptor subtype EP3.

    PubMed

    Ueta, Mayumi

    2010-11-01

    We first investigated whether the prostaglandin (PG) E2-PGE receptor subtype EP3 axis regulates the development of murine experimental allergic conjunctivitis because it has been reported that this pathway negatively regulates allergic reactions in a murine allergic asthma model. We observed that EP3 is constitutively expressed in mice conjunctival epithelium. EP3 knockout mice demonstrated significantly increased eosinophil infiltration in conjunctiva after ragweed challenge compared with wild-type mice. Consistently, significantly higher expression of eotaxin-1 messenger RNA was observed in Ptger3-/- mice. Conversely, treatment of wild-type mice with an EP3-selective agonist significantly decreased eosinophil infiltration, which was blunted in Ptger3-/- mice. Expression of cyclooxygenase-2 and PGE synthases was upregulated and PGE2 content increased in the eyelids after ragweed challenge. These data suggest that PGE2 acts on EP3 in the conjunctival epithelium and downregulates the progression of experimental allergic conjunctivitis. We next examined and compared the expression of EP3 in human conjunctival epithelium in various ocular surface diseases. Human conjunctival epithelium expressed EP3-specific messenger RNA and EP3 protein. Although we could clearly find positive signals in the conjunctival epithelium from patients with noninflammatory ocular surface diseases such as conjunctivochalasis and pterygium, we could not find positive signals in that from those with inflammatory disorders such as Stevens-Johnson syndrome and ocular cicatricial pemphigoid. Likewise, expression of the PGE receptor subtype EP4 was clearly found in the conjunctival epithelium from patients with conjunctivochalasis and pterygium but not from patients with Stevens-Johnson syndrome and ocular cicatricial pemphigoid.

  1. Prostanoid receptor EP2 as a therapeutic target.

    PubMed

    Ganesh, Thota

    2014-06-12

    Cycoloxygenase-2 (COX-2) induction is prevalent in a variety of (brain and peripheral) injury models where COX-2 levels correlate with disease progression. Thus, COX-2 has been widely explored for anti-inflammatory therapy with COX-2 inhibitors, which proved to be effective in reducing the pain and inflammation in patients with arthritis and menstrual cramps, but they have not provided any benefit to patients with chronic inflammatory neurodegenerative disease. Recently, two COX-2 drugs, rofecoxib and valdecoxib, were withdrawn from the United States market due to cardiovascular side effects. Thus, future anti-inflammatory therapy could be targeted through a specific prostanoid receptor downstream of COX-2. The PGE2 receptor EP2 is emerging as a pro-inflammatory target in a variety of CNS and peripheral diseases. Here we highlight the latest developments on the role of EP2 in diseases, mechanism of activation, and small molecule discovery targeted either to enhance or to block the function of this receptor.

  2. Activation of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) increases the expression of prostaglandin E2 receptor subtype EP4. The roles of phosphatidylinositol 3-kinase and CCAAT/enhancer-binding protein beta.

    PubMed

    Han, ShouWei; Ritzenthaler, Jeffrey D; Wingerd, Byron; Roman, Jesse

    2005-09-30

    The prostaglandin E2 receptor subtype EP4 has been implicated in the growth and progression of human non-small cell lung carcinoma (NSCLC). However, the factors that control its expression have not been entirely elucidated. Our studies show that NSCLC cells express peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) protein and that treatment with a selective PPARbeta/delta agonist (GW501516) increases EP4 mRNA and protein levels. GW501516 induced NSCLC cell proliferation, and this effect was prevented by PPARbeta/delta antisense or EP4 short interfering RNA (siRNA). GW501516 increased the phosphorylation of Akt and decreased PTEN expression. The selective inhibitor of phosphatidylinositol 3-kinase (PI3-K), wortmannin, and PPARbeta/delta antisense, abrogated the effect of GW501516 on EP4 expression, whereas that of the inhibitor of Erk did not. GW501516 also increased EP4 promoter activity through effects on the region between -1555 and -992 bp in the EP4 promoter, and mutation of the CCAAT/enhancer-binding protein (C/EBP) site in this region abrogated the effect of GW501516. GW501516 increased not only the binding activity of C/EBP to the NF-IL6 site in the EP4 promoter, which was prevented by the inhibitor of PI3-K, but also increased C/EBPbeta protein in a dose- and PPARbeta/delta-dependent manner. The effect of GW501516 on EP4 protein was eliminated in the presence of C/EBPbeta siRNA. Finally, we showed that pretreatment of NSCLC with GW501516 further increased NSCLC cell proliferation in response to exogenous dimethyl-prostaglandin E2 (PGE2) that was diminished in the presence of PPARbeta/delta antisense and EP4 siRNA. Taken together, these findings suggest that activation of PPARbeta/delta induces PGE2 receptor subtype EP4 expression through PI3-K signals and increases human lung carcinoma cell proliferation in response to PGE2. The increase in transcription of the EP4 gene by PPARbeta/delta agonist was associated with increased C

  3. A prostaglandin E2 receptor antagonist prevents pregnancies during a preclinical contraceptive trial with female macaques

    PubMed Central

    Peluffo, M.C.; Stanley, J.; Braeuer, N.; Rotgeri, A.; Fritzemeier, K.-H.; Fuhrmann, U.; Buchmann, B.; Adevai, T.; Murphy, M.J.; Zelinski, M.B.; Lindenthal, B.; Hennebold, J.D.; Stouffer, R.L.

    2014-01-01

    STUDY QUESTION Can administration of a prostaglandin (PG) E2 receptor 2 (PTGER2) antagonist prevent pregnancy in adult female monkeys by blocking periovulatory events in the follicle without altering menstrual cyclicity or general health? SUMMARY ANSWER This is the first study to demonstrate that a PTGER2 antagonist can serve as an effective non-hormonal contraceptive in primates. WHAT IS KNOWN ALREADY The requirement for PGE2 in ovulation and the release of an oocyte surrounded by expanded cumulus cells (cumulus–oocyte expansion; C-OE) was established through the generation of PTGS2 and PTGER2 null-mutant mice. A critical role for PGE2 in primate ovulation is supported by evidence that intrafollicular injection of indomethacin in rhesus monkeys suppressed follicle rupture, whereas co-injection of PGE2 with indomethacin resulted in ovulation. STUDY DESIGN, SIZE, DURATION First, controlled ovulation protocols were performed in adult, female rhesus monkeys to analyze the mRNA levels for genes encoding PGE2 synthesis and signaling components in the naturally selected pre-ovulatory follicle at different times after the ovulatory hCG stimulus (0, 12, 24, 36 h pre-ovulation; 36 h post-ovulation, n = 3–4/time point). Second, controlled ovarian stimulation cycles were utilized to obtain multiple cumulus–oocyte complexes (COCs) from rhesus monkeys to evaluate the role of PGE2 in C-OE in vitro (n = 3–4 animals/treatment; ≥3 COCs/animal/treatment). Third, adult cycling female cynomolgus macaques were randomly assigned (n = 10/group) to vehicle (control) or PTGER2 antagonist (BAY06) groups to perform a contraceptive trial. After the first treatment cycle, a male of proven fertility was introduced into each group and they remained housed together for the duration of the 5-month contraceptive trial that was followed by a post-treatment reversibility trial. PARTICIPANTS/MATERIALS, SETTING, METHODS Quantitative real-time PCR, COC culture and expansion, immunofluorescence

  4. Copper amplification of prostaglandin E/sub 2/ stimulation of the release of luteinizing hormone-releasing hormone is a postreceptor event

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barnea, A.; Cho, G.

    1987-01-01

    The authors have shown that copper amplifies prostaglandin E/sub 2/ (PGE/sub 2/) stimulation of luteinizing hormone-releasing hormone (LH-RH) from explants of the median eminence area (MEA) and that this process is calcium-dependent. Since a Ca-cAMP pathway has been implicated in PGE/sub 2/ action on the LH-RH neuron, in this study the authors wished to ascertain if copper exerts its effect on the PGE/sub 2/ receptor or on a postreceptor component involved in PGE/sub 2/ action. MEA of adult male rats were incubated for 5 min with 200 ..mu..M Cu/histidine and then incubated for 15 min either with 10 ..mu..M PGE/submore » 2/ (Cu/PGE/sub 2/), 100 ..mu..M forskolin (Cu/forskolin), or 1 mM 8-bromoadenosine 3',5'-cyclic monophosphate (Cu/cAMP). Basal release of LH-RH was 4.6 +/- 0.45 pg/15 min per MEA determined by radioimmunoassay. Net stimulated release during the 15-min exposure to PGE/sub 2/, forskolin, or 8-bromoadenosine 3',5'-cyclic monophosphate was 3.6 +/- 0.52, 3.1 +/- 0.39, and 1.6 +/- 0.42 pg/15 min per MEA, respectively. Net stimulated release after exposure to Cu/PGE/sub 2/, Cu/forskolin, or Cu/cAMP indicated that copper amplifies the action of PGE/sub 2/ and forskolin but not cAMP action. When MEA were exposed to a mixture of PGE/sub 2/ and forskolin for 15 min, the effects of these two secretagogues on LH-RH release were not additive. In contrast to PGE/sub 2/ and forskolin, copper did not amplify K/sup +/ stimulation of OH-RH release. These results are supportive of the proposition that PGE/sub 2/ stimulation of OH-RH release is mediated by the Ca-cAMP pathway and that copper amplification of PGE/sub 2/ action is a postreceptor event.« less

  5. Aerosolized PGE1, PGI2 and nitroprusside protect against vascular leakage in lung ischaemia-reperfusion.

    PubMed

    Schütte, H; Löckinger, A; Seeger, W; Grimminger, F

    2001-07-01

    High permeability oedema is an important feature in lung injury secondary to ischaemia-reperfusion. This study investigated the influence of aerosolized prostaglandin E1 (PGE1), prostaglandin I2 (PCI2) and the nitric oxide (NO)-donor, sodium nitroprusside (SNP) on microvascular barrier function in pulmonary ischaemia-reperfusion. Buffer-perfused rabbit lungs were exposed to 180 or 210 min of warm ischaemia while maintaining anoxic ventilation and a positive intravascular pressure. Reperfusion provoked a transient, mostly precapillary elevation of vascular resistance, followed by a severe increase of the capillary filtration coefficient (Kfc) versus nonischaemic controls (3.17+/-0.34 versus 0.85+/-0.05 cm3 x s(-1) cmH2O(-1) x g(-1) x 10(-4) after 30 min of reperfusion), and progressive oedema formation. Short-term aerosolization of SNP, PGE1 or PGI2 at the beginning of ischaemia largely suppressed the Kfc increase (1.36+/-0.22, 1.32+/-0.23 and 1.32+/-0.22 cm3 x s(-1) x cmH2O(-1) x g(-1) x 10(-4), respectively) and oedema formation. In contrast, application prior to reperfusion was much less effective, with some reduction of Kfc increase by PGI2 and SNP and no effect of PGE, (1.79+/-0.31, 2.2+/-0.53 and 3.2+/-0.05 cm3 x s(-1) x cmH2O(-1) x g(-1) x 10(-4), respectively). Haemodynamics, including microvascular pressure, were only marginally affected by the chosen doses of aerosolized vasodilators. It is concluded that short-term aerosolization of prostaglandin E1, prostaglandin I2 and sodium nitroprusside at the onset of ischaemia is highly effective in maintaining endothelial barrier properties in pulmonary ischaemia-reperfusion. This effect is apparently attributable to nonvasodilatory mechanisms exerted by these agents. Alveolar deposition of prostaglandins and/or nitric oxide donors by the aerosol technique may offer pulmonary protection in ischaemia-reperfusion injury.

  6. Stretch independent regulation of prostaglandin E(2) production within the isolated guinea-pig lamina propria.

    PubMed

    Nile, Christopher J; de Vente, Jan; Gillespie, James I

    2010-02-01

    To use an isolated preparation of the guinea-pig bladder lamina propria (LP) to investigate the effects of adenosine tri-phosphate (ATP) and nitric oxide (NO) on the release of prostaglandin E(2) (PGE(2)). The bladders of female guinea-pigs (200-400 g) were isolated and opened to expose the urothelial surface. The LP was dissected free of the underlying detrusor muscle and cut into strips from the dome to base. Strips were then incubated in Krebs buffer at 37 degrees C. Each tissue piece was then exposed to the stable ATP analogue, BzATP, and a NO donor, diethylamine-NONOate (DEANO), and the effect on PGE(2) output into the supernatant determined using the Parameter(TM) PGE(2) enzyme immunoassay kit (R & D Systems, Abingdon, UK). Experiments were repeated in the presence of purinergic receptor and cyclooxygenase (COX) enzymes, COX I and COX II, antagonists. The cellular location of COX I, COX II and neuronal NO synthase (nNOS) within the bladder LP was also determined by immunohistochemistry. PGE(2) production was significantly increased by BzATP. Antagonist studies showed the purinergic stimulation involved both P(2)X and P(2)Y receptors. The BzATP response was inhibited by the COX inhibitor indomethacin (COX I >COX II) but not by DUP 697 (COX II >COX I). Thus, BzATP stimulation occurs because of COX I stimulation. NO had no effect on PGE(2) production over the initial 10 min of an exposure. However, PGE(2) output was increased 100 min after exposure to the NO donor. In the presence of NO, the BzATP stimulation was abolished. Immunohistochemistry was used to confirm the location of COX I to the basal and inner intermediate urothelial layers and to cells within the diffuse layer of LP interstitial cells. In addition, nNOS was also located in the basal urothelial layers whilst COX II was found in the interstitial cell layers. There is complex interaction between ATP and NO to modulate PGE(2) release from the bladder LP in the un-stretched preparation. Such

  7. The prostaglandin receptor EP2 activates multiple signaling pathways and β-arrestin1 complex formation during mouse skin papilloma development

    PubMed Central

    Chun, Kyung-Soo; Lao, Huei-Chen; Trempus, Carol S.; Okada, Manabu; Langenbach, Robert

    2009-01-01

    Prostaglandin E2 (PGE2) is elevated in many tumor types, but PGE2's contributions to tumor growth are largely unknown. To investigate PGE2's roles, the contributions of one of its receptors, EP2, were studied using the mouse skin initiation/promotion model. Initial studies indicated that protein kinase A (PKA), epidermal growth factor receptor (EGFR) and several effectors—cyclic adenosine 3′,5′-monophosphate response element-binding protein (CREB), H-Ras, Src, protein kinase B (AKT) and extracellular signal-regulated kinase (ERK)1/2—were activated in 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted papillomas and that PKA and EGFR inhibition (H89 and AG1478, respectively) decreased papilloma formation. EP2's contributions to the activation of these pathways and papilloma development were determined by inhibiting endogenous TPA-induced PGE2 production with indomethacin (Indo) and concomitantly treating with the EP2 agonist, CAY10399 (CAY). CAY treatment restored papilloma formation in TPA/Indo-treated mice and increased cyclic adenosine 3′,5′-monophosphate and PKA activation as measured by p-CREB formation. CAY treatment also increased EGFR and Src activation and their inhibition by AG1478 and PP2 indicated that Src was upstream of EGFR. CAY also increased H-Ras, ERK1/2 and AKT activation, and AG1478 decreased their activation indicating EGFR being upstream. Supporting EP2's contribution, EP2−/− mice exhibited 65% fewer papillomas and reduced Src, EGFR, H-Ras, AKT and ERK1/2 activation. G protein-coupled receptor (GPCR) activation of EGFR has been reported to involve Src's activation via a GPCR–β-arrestin–Src complex. Indeed, immunoprecipitation of β-arrestin1 or p-Src indicated the presence of an EP2–β-arrestin1–p-Src complex in papillomas. The data indicated that EP2 contributed to tumor formation via activation of PKA and EGFR and that EP2 formed a complex with β-arrestin1 and Src that contributed to signaling and/or EP2

  8. Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term.

    PubMed

    Kelly, A J; Kavanagh, J; Thomas, J

    2003-01-01

    augmentation reduced (53.9% versus 89.1%, RR 0.60, 95% CI 0.43 to 0.84, 11 trials, 1265 women) with the use of vaginal PGF2a. There were insufficient data to make meaningful conclusions for the comparison of vaginal PGE2 and PGF2a.PGE2 tablet, gel and pessary appear to be as efficacious as each other. Lower dose regimens, as defined in the review, appear as efficacious as higher dose regimens. The primary aim of this review was to examine the efficacy of vaginal prostaglandin E2 and F2a. This is reflected by an increase in successful vaginal delivery rates in 24 hours, no increase in operative delivery rates and significant improvements in cervical favourability within 24 to 48 hours. Further research is needed to quantify the cost-analysis of induction of labour with vaginal prostaglandins, with special attention to different methods of administration.

  9. Aromatase expression in a human osteoblastic cell line increases in response to prostaglandin E(2) in a dexamethasone-dependent fashion.

    PubMed

    Watanabe, M; Noda, M; Nakajin, S

    2007-09-01

    Recent progress supports the importance of local estrogen secretion in human bone tissue to increase and maintain bone-mineral density. In a previous report, we found that forskolin (FSK) synergistically induces aromatase (CYP19: a rate-limiting enzyme for estrogen synthesis) expression in dexamethasone (Dex) dependent manner in a human osteoblastic cell line, SV-HFO [Watanabe M, Ohno S, Nakajin S. Forskolin and dexamethasone synergistically induce aromatase (CYP19) expression in the human osteoblastic cell line SV-HFO. Eur J Endocrinol 2005;152:619-24]. In this report, we investigated whether prostaglandin (PG) E(2) induces estrogen production, in other words, if PGE(2) exerts the same effect as FSK because PGE(2) is the major prostanoid in the bone and is one of the key molecules in the osteoblast. We found PGE(2) up-regulates aromatase activity synergistically, but this up-regulation depends on Dex. CYP19 gene expression was also increased synergistically by Dex and PGE(2). Promoter I.4 was activated synergistically by PGE(2) and Dex. PGE(2) receptor, EP(1), EP(2) and EP(4) were involved in the up-regulation of aromatase activity in response to PGE(2) in a Dex-dependent manner. The cAMP-PKA pathway and Ca(2+) signaling pathway were involved in the up-regulation of aromatase activity in response to PGE(2). Furthermore, glucocorticoid response element on promoter I.4 sequence was an essential minimum requirement for its activity and synergism of PGE(2) and Dex. These findings are the first report on osteoblastic cell line which uses predominantly promoter I.4 to drive aromatase expression. These findings also suggest that endogenous PGE(2) produced in bone mainly may synergistically support local estrogen production in osteoblastic cells in the presence of glucocorticoid.

  10. Coculture with endothelial cells enhances osteogenic differentiation of periodontal ligament stem cells via cyclooxygenase-2/prostaglandin E2/vascular endothelial growth factor signaling under hypoxia.

    PubMed

    Zhao, Lixing; Wu, Yeke; Tan, Lijun; Xu, Zhenrui; Wang, Jun; Zhao, Zhihe; Li, Xiaoyu; Li, Yu; Yang, Pu; Tang, Tian

    2013-12-01

    During periodontitis and orthodontic tooth movement, periodontal vasculature is severely impaired, leading to a hypoxic microenvironment of periodontal cells. However, the impact of hypoxia on periodontal cells is poorly defined. The present study investigates responses of cocultured endothelial cells (ECs) and periodontal ligament stem cells (PDLSCs) to hypoxia. Osteogenic differentiation, molecular characterization, and various behaviors of PDLSCs and human umbilical venous ECs under hypoxia were assessed by quantitative real-time reverse-transcription polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. Moreover, the effect of ECs on PDLSC osteogenic differentiation was tested using NS398 (cyclooxygenase 2 blocker), SU5416 (vascular endothelial growth factor [VEGF] receptor inhibitor), AH6809, L-798106, and L-161982 (EP1/2/3/4 antagonists). First, hypoxia promoted osteogenic differentiation in PDLSCs and enhanced EC migration, whereas PD98059 (extracellular signal-regulated protein kinase [ERK] inhibitor) blocked, and cocultured ECs further enhanced, hypoxia-induced osteogenic differentiation. Second, NS398 impaired EC migration and prostaglandin E2 (PGE2)/VEGF release, whereas cocultured PDLSCs and exogenous PGE2 partially reversed it. Third, NS398 (pretreated ECs) decreased PGE2/VEGF concentrations. NS398-treated ECs and AH6809/SU5416-treated PDLSCs impaired cocultured EC-induced enhancement of PDLSC osteogenic differentiation. Hypoxia enhances ERK-mediated osteogenic differentiation in PDLSCs. Coculture with EC further augments PDLSC osteogenic differentiation via cyclooxygenase-2/PGE2/VEGF signaling.

  11. Microsomal PGE2 synthase-1 regulates melanoma cell survival and associates with melanoma disease progression

    PubMed Central

    Kim, Sun-Hee; Hashimoto, Yuuri; Cho, Sung-Nam; Roszik, Jason; Milton, Denái R.; Dal, Fulya; Kim, Sangwon F.; Menter, David G.; Yang, Peiying; Ekmekcioglu, Suhendan; Grimm, Elizabeth A.

    2016-01-01

    Summary COX-2 and its product PGE2 enhance carcinogenesis and tumor progression, which has been previously reported in melanoma. As most COX inhibitors cause much toxicity, the downstream microsomal PGE2 synthase-1 (mPGES1) is a consideration for targeting. Human melanoma TMAs were employed for testing mPGES1 protein staining intensity and percentage levels and both increased with clinical stage; employing a different Stage III TMA, mPGES1 intensity (not percentage) associated with reduced patient survival. Our results further show that iNOS was also highly expressed in melanoma tissues with high mPGES1 levels, and iNOS-mediated NO promoted mPGES1 expression and PGE2 production. An mPGES1specific inhibitor (CAY10526) as well as siRNA attenuated cell survival and increased apoptosis. CAY10526 significantly suppressed tumor growth and increased apoptosis in melanoma xenografts. Our findings support the value of a prognostic and predictive role for mPGES1, and suggest targeting this molecule in the PGE2 pathway as another avenue toward improving melanoma therapy. PMID:26801201

  12. P2X7 ionotropic receptor is functionally expressed in rabbit articular chondrocytes and mediates extracellular ATP cytotoxicity.

    PubMed

    Tanigawa, Hitoshi; Toyoda, Futoshi; Kumagai, Kosuke; Okumura, Noriaki; Maeda, Tsutomu; Matsuura, Hiroshi; Imai, Shinji

    2018-05-29

    Extracellular ATP regulates various cellular functions by engaging multiple subtypes of P2 purinergic receptors. In many cell types, the ionotropic P2X7 receptor mediates pathological events such as inflammation and cell death. However, the importance of this receptor in chondrocytes remains largely unexplored. Here, we report the functional identification of P2X7 receptor in articular chondrocytes and investigate the involvement of P2X7 receptors in ATP-induced cytotoxicity. Chondrocytes were isolated from rabbit articular cartilage, and P2X7 receptor currents were examined using the whole-cell patch-clamp technique. ATP-induced cytotoxicity was evaluated by measuring caspase-3/7 activity, lactate dehydrogenase (LDH) leakage, and prostagrandin E 2 (PGE 2 ) release using microscopic and fluorimetric/colorimetric evaluation. Extracellular ATP readily evoked a cationic current without obvious desensitization. This ATP-activated current was dose related, but required millimolar concentrations. A more potent P2X7 receptor agonist, BzATP, also activated this current but at 100-fold lower concentrations. ATP-induced currents were largely abolished by selective P2X7 antagonists, suggesting a predominant role for the P2X7 receptor. RT-PCR confirmed the presence of P2X7 in chondrocytes. Heterologous expression of a rabbit P2X7 clone successfully reproduced the ATP-induced current. Exposure of chondrocytes to ATP increased caspase-3/7 activities, an effect that was totally abrogated by P2X7 receptor antagonists. Extracellular ATP also enhanced LDH release, which was partially attenuated by the P2X7 inhibitor. The P2X7 receptor-mediated elevation in apoptotic caspase signaling was accompanied by increased PGE 2 release and was attenuated by inhibition of either phospholipase A 2 or cyclooxygenase-2. This study provides direct evidence for the presence of functional P2X7 receptors in articular chondrocytes. Our results suggest that the P2X7 receptor is a potential therapeutic

  13. Misoprostol inhibits gastric mucosal release of endogenous prostaglandin E2 and thromboxane B2 in healthy volunteers.

    PubMed Central

    Mertz-Nielsen, A; Eskerod, O; Bukhave, K; Rask-Madsen, J

    1995-01-01

    Prostaglandin analogues of the E-series theoretically offer the ideal antiulcer drugs. Peptic ulcer healing with prostaglandin analogues is, however, no better than would be predicted from their ability to inhibit gastric acid secretion and they are less effective than histamine H2 receptor antagonists in preventing ulcer relapse. It could be that prostaglandin analogues inhibit gastric mucosal synthesis or release of endogenous eicosanoids, thereby abrogating their own effects. This study, therefore, examined how a single therapeutic dose (200 micrograms) of misoprostol, a synthetic analogue of prostaglandin E1, influences gastric mucosal release of endogenous prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and chemotactic leukotriene B4 (LTB4) during basal conditions and in response to gastric luminal acidification (0.1 M HCl; 5 ml/min for 10 minutes). Nine healthy volunteers were studied in a single blind, cross over design. In each subject misoprostol or placebo was instilled in randomised order into the stomach, which was subsequently perfused with isotonic mannitol. Misoprostol significantly decreased basal as well as acid stimulated output of PGE2 and TXB2, without affecting output of LTB4. These data show that misoprostol inhibits gastric mucosal synthesis of prostanoids. Decreased concentrations, or even a changed profile, of native eicosanoids modulating the release of inflammatory mediators from immune cells might explain why prostaglandin analogues have a comparatively poor clinical performance in ulcer healing and prevention. PMID:7737555

  14. Inhibition of COX-2 and PGE2 in LPS-stimulated RAW264.7 cells by lonimacranthoide VI, a chlorogenic acid ester saponin

    PubMed Central

    GUAN, FUQIN; WANG, HAITING; SHAN, YU; CHEN, YU; WANG, MING; WANG, QIZHI; YIN, MIN; ZHAO, YOUYI; FENG, XU; ZHANG, JIANHUA

    2014-01-01

    Lonimacranthoide VI, first isolated from the flower buds of Lonicera macranthoides in our previous study, is a rare chlorogenic acid ester acylated at C-23 of hederagenin. In the present study, the anti-inflammatory effects of lonimacranthoide VI were studied. Lipopolysaccharides (LPS) induced an inflammatory response through the production of prostaglandin E2 (PGE2), and these levels were reduced when lonimacranthoide VI was pre-administered. Additionally, the mechanism of the anti-inflammatory effects of lonimacranthoide VI was investigated by measuring cyclooxygenase (COX) activity and mRNA expression. The results showed that lonimacranthoide VI inhibited mRNA expression and in vitro activity of COX-2 in a dose-dependent manner, whereas only the higher lonimacranthoide VI concentration possibly reduced COX-1 expression and in vitro activity. Taken together, these results indicate that lonimacranthoide VI is an important anti-inflammatory constituent of Lonicera macranthoides and that the anti-inflammatory effect is attributed to the inhibition of PGE2 production through COX activity and mRNA expression. PMID:25054024

  15. Hypoxia and prostaglandin E receptor 4 signalling pathways synergise to promote endometrial adenocarcinoma cell proliferation and tumour growth.

    PubMed

    Catalano, Rob D; Wilson, Martin R; Boddy, Sheila C; McKinlay, Andrew T M; Sales, Kurt J; Jabbour, Henry N

    2011-05-12

    The prostaglandin endoperoxide synthase (PTGS) pathway is a potent driver of tumour development in humans by enhancing the biosynthesis and signalling of prostaglandin (PG) E(2). PTGS2 expression and PGE(2) biosynthesis is elevated in endometrial adenocarcinoma, however the mechanism whereby PTGS and PGE(2) regulate endometrial tumour growth is unknown. Here we investigated (a) the expression profile of the PGE synthase enzymes (PTGES, PTGES-2, PTGES-3) and PGE receptors (PTGER1-4) in endometrial adenocarcinomas compared with normal endometrium and (b) the role of PTGER4 in endometrial tumorigenesis in vivo. We found elevated expression of PTGES2 and PTGER4 and suppression of PTGER1 and PTGER3 in endometrial adenocarcinomas compared with normal endometrium. Using WT Ishikawa endometrial adenocarcinoma cells and Ishikawa cells stably transfected with the full length PTGER4 cDNA (PTGER4 cells) xenografted in the dorsal flanks of nude mice, we show that PTGER4 rapidly and significantly enhances tumour growth rate. Coincident with enhanced PTGER4-mediated tumour growth we found elevated expression of PTGS2 in PTGER4 xenografts compared with WT xenografts. Furthermore we found that the augmented growth rate of the PTGER4 xenografts was not due to enhanced angiogenesis, but regulated by an increased proliferation index and hypoxia. In vitro, we found that PGE(2) and hypoxia independently induce expression of PTGER4 indicating two independent pathways regulating prostanoid receptor expression. Finally we have shown that PGE(2) and hypoxia synergise to promote cellular proliferation of endometrial adenocarcinoma cells.

  16. Hypoxia and Prostaglandin E Receptor 4 Signalling Pathways Synergise to Promote Endometrial Adenocarcinoma Cell Proliferation and Tumour Growth

    PubMed Central

    Catalano, Rob D.; Wilson, Martin R.; Boddy, Sheila C.; McKinlay, Andrew T. M.; Sales, Kurt J.; Jabbour, Henry N.

    2011-01-01

    The prostaglandin endoperoxide synthase (PTGS) pathway is a potent driver of tumour development in humans by enhancing the biosynthesis and signalling of prostaglandin (PG) E2. PTGS2 expression and PGE2 biosynthesis is elevated in endometrial adenocarcinoma, however the mechanism whereby PTGS and PGE2 regulate endometrial tumour growth is unknown. Here we investigated (a) the expression profile of the PGE synthase enzymes (PTGES, PTGES-2, PTGES-3) and PGE receptors (PTGER1–4) in endometrial adenocarcinomas compared with normal endometrium and (b) the role of PTGER4 in endometrial tumorigenesis in vivo. We found elevated expression of PTGES2 and PTGER4 and suppression of PTGER1 and PTGER3 in endometrial adenocarcinomas compared with normal endometrium. Using WT Ishikawa endometrial adenocarcinoma cells and Ishikawa cells stably transfected with the full length PTGER4 cDNA (PTGER4 cells) xenografted in the dorsal flanks of nude mice, we show that PTGER4 rapidly and significantly enhances tumour growth rate. Coincident with enhanced PTGER4-mediated tumour growth we found elevated expression of PTGS2 in PTGER4 xenografts compared with WT xenografts. Furthermore we found that the augmented growth rate of the PTGER4 xenografts was not due to enhanced angiogenesis, but regulated by an increased proliferation index and hypoxia. In vitro, we found that PGE2 and hypoxia independently induce expression of PTGER4 indicating two independent pathways regulating prostanoid receptor expression. Finally we have shown that PGE2 and hypoxia synergise to promote cellular proliferation of endometrial adenocarcinoma cells. PMID:21589857

  17. Polymorphisms in the prostaglandin receptor EP2 gene confers susceptibility to tuberculosis.

    PubMed

    Liang, Li; Zhang, Qing; Luo, Liu-Lin; Yue, Jun; Zhao, Yan-Lin; Han, Min; Liu, Li-Rong; Xiao, He-Ping

    2016-12-01

    Prostaglandin E2 (PGE2) is an important lipid mediator of the inflammatory immune response during acute and chronic infections. PGE2 modulates a variety of immune functions via four receptors (EP1-EP4), which mediate distinct PGE2 effects. Mice lacking EP2 are more susceptible to infection by Mycobacterium tuberculosis (M.tb), have a higher bacterial load, and increase size and number of granulomatous lesions. Our aim was to assess whether single nucleotide polymorphisms (SNPs) in EP2 increase the risk of tuberculosis. DNA re-sequencing revealed five common EP2 variants in the Chinese Han population. We sequenced the EP2 gene from 600 patients and 572 healthy controls to measure SNP frequencies in association with tuberculosis infections (TB) within the population. The rs937337 polymorphism is associated with increased risk to tuberculosis (p=0.0044, odds ratio [OR], 1.67; 95% confidential interval,1.22-2.27). The rs937337 AA genotype and the rs1042618 CC genotype were significantly associated with TB. An estimation of the frequencies of haplotypes revealed a single protective haplotype GACGC for tuberculosis (p=0.00096, odds ratio [OR], 0.56; 95% confidential interval, 0.41-0.77). Furthermore, we determined that the remaining SNPs of EP2 were nominally associated with clinical patterns of disease. We identified genetic polymorphisms in EP2 associated with susceptibility to tuberculosis within a Chinese population. Our data support that EP2 SNPs are genetic predispositions of increased susceptibility to TB and to different clinical patterns of disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Microsomal PGE2 synthase-1 regulates melanoma cell survival and associates with melanoma disease progression.

    PubMed

    Kim, Sun-Hee; Hashimoto, Yuuri; Cho, Sung-Nam; Roszik, Jason; Milton, Denái R; Dal, Fulya; Kim, Sangwon F; Menter, David G; Yang, Peiying; Ekmekcioglu, Suhendan; Grimm, Elizabeth A

    2016-05-01

    COX-2 and its product PGE2 enhance carcinogenesis and tumor progression, which has been previously reported in melanoma. As most COX inhibitors cause much toxicity, the downstream microsomal PGE2 synthase-1 (mPGES1) is a consideration for targeting. Human melanoma TMAs were employed for testing mPGES1 protein staining intensity and percentage levels, and both increased with clinical stage; employing a different Stage III TMA, mPGES1 intensity (not percentage) associated with reduced patient survival. Our results further show that iNOS was also highly expressed in melanoma tissues with high mPGES1 levels, and iNOS-mediated NO promoted mPGES1 expression and PGE2 production. An mPGES1-specific inhibitor (CAY10526) as well as siRNA attenuated cell survival and increased apoptosis. CAY10526 significantly suppressed tumor growth and increased apoptosis in melanoma xenografts. Our findings support the value of a prognostic and predictive role for mPGES1, and suggest targeting this molecule in the PGE2 pathway as another avenue toward improving melanoma therapy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. MicroRNA-144 is regulated by CP2 and decreases COX-2 expression and PGE2 production in mouse ovarian granulosa cells

    PubMed Central

    Zhou, Jiawei; Lei, Bin; Li, Huanan; Zhu, Lihua; Wang, Lei; Tao, Hu; Mei, Shuqi; Li, Fenge

    2017-01-01

    Mammalian folliculogenesis is a complex process in which primordial follicles develop into pre-ovulatory follicles, followed by ovulation to release mature oocytes. In this study, we explored the role of miR-144 in ovulation. miR-144 was one of the differentially expressed microRNAs, which showed 5.59-fold changes, in pre-ovulatory ovarian follicles between Large White and Chinese Taihu sows detected by Solexa deep sequencing. We demonstrated that overexpression of miR-144 significantly decreased the luciferase reporter activity under the control of the cyclooxygenase-2 (COX-2) or mothers against decapentaplegic homologue 4 (Smad4) 3'-untranslated region (3'-UTR) and suppressed COX-2 and Smad4 expression. In contrast, a miR-144 inhibitor increased COX-2 and Smad4 expression in mouse granulosa cells (mGCs). Meanwhile, Smad4 upregulated COX-2 expression, but this effect was abolished when the mGCs were treated with the transforming growth factor beta signalling pathway inhibitor SB431542. Moreover, luciferase reporter, chromatin immunoprecipitation and electrophoretic mobility shift assay results showed that the transcription factor CP2 upregulated miR-144 expression, which partially contributed to the suppression of COX-2 in mGCs. Both CP2 and miR-144 alter prostaglandin E2 (PGE2) production by regulating COX-2 expression. In addition, miR-144 regulated mGC apoptosis and affected follicular atresia, but these activities did not appear to be through COX-2 and Smad4. Taken together, we revealed an important CP2/miR-144/COX-2/PGE2/ovulation pathway in mGCs. PMID:28182010

  20. Prostaglandin PGE2: a possible mechanism for bone destruction in calcinosis circumscripta.

    PubMed

    Caniggia, A; Gennari, C; Vattimo, A; Runci, F; Bombardieri, S

    1978-02-28

    A patient showed evident osteolysis in phalanges and heavy periarticular calcium deposits of the fingers, wrists and toes which avidly took up 47Ca. The dense, white, tooth-paste like fluid contained in the periarticular calcium deposits has been studied by two different X-ray diffraction methods, by Ubatuba's bioassay for prostaglandin, by thin layer chromatography and by mass spectrometry. The calcium deposits were hydroxyapatite and prostaglandin PGE2 was detected in them. The bone resorption stimulating activity of PGE2 would be expected to result in increased bone destruction with release of calcium salts and this could be a working hypothesis of the pathogenesis of calcinosis circumscripta.

  1. Isoliquiritigenin, a flavonoid from licorice, blocks M2 macrophage polarization in colitis-associated tumorigenesis through downregulating PGE{sub 2} and IL-6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhao, Haixia; Zhang, Xinhua; Chen, Xuewei

    M2 macrophage polarization is implicated in colorectal cancer development. Isoliquiritigenin (ISL), a flavonoid from licorice, has been reported to prevent azoxymethane (AOM) induced colon carcinogenesis in animal models. Here, in a mouse model of colitis-associated tumorigenesis induced by AOM/dextran sodium sulfate (DSS), we investigated the chemopreventive effects of ISL and its mechanisms of action. Mice were treated with AOM/DSS and randomized to receive either vehicle or ISL (3, 15 and 75 mg/kg). Tumor load, histology, immunohistochemistry, and gene and protein expressions were determined. Intragastric administration of ISL for 12 weeks significantly decreased colon cancer incidence, multiplicity and tumor size bymore » 60%, 55.4% and 42.6%, respectively. Moreover, ISL inhibited M2 macrophage polarization. Such changes were accompanied by downregulation of PGE{sub 2} and IL-6 signaling. Importantly, depletion of macrophages by clodronate (Clod) or zoledronic acid (ZA) reversed the effects of ISL. In parallel, in vitro studies also demonstrated that ISL limited the M2 polarization of RAW264.7 cells and mouse peritoneal macrophages with concomitant inactivation of PGE{sub 2}/PPARδ and IL-6/STAT3 signaling. Conversely, exogenous addition of PGE{sub 2} or IL-6, or overexpression of constitutively active STAT3 reversed ISL-mediated inhibition of M2 macrophage polarization. In summary, dietary flavonoid ISL effectively inhibits colitis-associated tumorigenesis through hampering M2 macrophage polarization mediated by the interplay between PGE{sub 2} and IL-6. Thus, inhibition of M2 macrophage polarization is likely to represent a promising strategy for chemoprevention of colorectal cancer. - Highlights: • Isoliquiritigenin (ISL) prevents colitis-associated tumorigenesis. • ISL inhibits M2 macrophage polarization in vivo and in vitro. • ISL inhibits PGE{sub 2} and IL-6 signaling in colitis-associated tumorigenesis. • ISL may be an attractive candidate

  2. Hyperforin, an Anti-Inflammatory Constituent from St. John's Wort, Inhibits Microsomal Prostaglandin E2 Synthase-1 and Suppresses Prostaglandin E2 Formation in vivo

    PubMed Central

    Koeberle, Andreas; Rossi, Antonietta; Bauer, Julia; Dehm, Friederike; Verotta, Luisella; Northoff, Hinnak; Sautebin, Lidia; Werz, Oliver

    2010-01-01

    The acylphloroglucinol hyperforin (Hyp) from St. John's wort possesses anti-inflammatory and anti-carcinogenic properties which were ascribed among others to the inhibition of 5-lipoxygenase. Here, we investigated whether Hyp also interferes with prostanoid generation in biological systems, particularly with key enzymes participating in prostaglandin (PG)E2 biosynthesis, i.e., cyclooxygenases (COX)-1/2 and microsomal PGE2 synthase (mPGES)-1 which play key roles in inflammation and tumorigenesis. Similar to the mPGES-1 inhibitors MK-886 and MD-52, Hyp significantly suppressed PGE2 formation in whole blood assays starting at 0.03–1 μM, whereas the concomitant generation of COX-derived 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, thromboxane B2, and 6-keto PGF1α was not significantly suppressed up to 30 μM. In cell-free assays, Hyp efficiently blocked the conversion of PGH2 to PGE2 mediated by mPGES-1 (IC50 = 1 μM), and isolated COX enzymes were not (COX-2) or hardly (COX-1) suppressed. Intraperitoneal (i.p.) administration of Hyp (4 mg kg−1) to rats impaired exudate volume and leukocyte numbers in carrageenan-induced pleurisy associated with reduced PGE2 levels, and Hyp (given i.p.) inhibited carrageenan-induced mouse paw edema formation (ED50 = 1 mg kg−1) being superior over indomethacin (ED50 = 5 mg kg−1). We conclude that the suppression of PGE2 biosynthesis in vitro and in vivo by acting on mPGES-1 critically contributes to the anti-inflammatory efficiency of Hyp. PMID:21687502

  3. Creatine supplementation reduces plasma levels of pro-inflammatory cytokines and PGE2 after a half-ironman competition.

    PubMed

    Bassit, R A; Curi, R; Costa Rosa, L F B P

    2008-08-01

    The effect of creatine supplementation upon plasma levels of pro-inflammatory cytokines: Interleukin (IL) 1 beta and IL-6, Tumor Necrosis Factor alpha (TNFalpha), and Interferon alpha (INF alpha) and Prostaglandin E(2) (PGE(2)) after a half-ironman competition were investigated. Eleven triathletes, each with at least three years experience of participation in this sport were randomly divided between the control and experimental groups. During 5 days prior to competition, the control group (n = 6) was supplemented with carbohydrate (20 g x d(-1)) whereas the experimental group (n = 5) received creatine (20 g x d(-1)) in a double-blind trial. Blood samples were collected 48 h before and 24 and 48 h after competition and were used for the measurement of cytokines and PGE(2). Forty-eight hours prior to competition there was no difference between groups in the plasma concentrations (pg x ml(-1), mean +/- SEM) of IL-6 (7.08 +/- 0.63), TNFalpha (76.50 +/- 5.60), INF alpha (18.32 +/- 1.20), IL-1 beta (23.42 +/- 5.52), and PGE(2) (39.71 +/- 3.8). Twenty-four and 48 h after competition plasma levels of TNFalpha, INF alpha, IL-1 beta and PGE(2) were significantly increased (P < 0.05) in both groups. However, the increases in these were markedly reduced following creatine supplementation. An increase in plasma IL-6 was observed only after 24 h and, in this case, there was no difference between the two groups. Creatine supplementation before a long distance triathlon competition may reduce the inflammatory response induced by this form of strenuous of exercise.

  4. Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

    PubMed

    Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

    2003-12-01

    Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p < 0.001). Blocking of COX-2 by NS398 abolished PGE2 production, but did not alter the cytokine patterns induced by Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

  5. [Induced abortion using prostaglandin E2 and F2alpha gel].

    PubMed

    Lippert, T H; Modly, T

    1974-01-01

    In this study of 20 patients in the 13th-17th week of pregnancy abortion was induced with intrauterine, extraamniotic application of prostaglandins (PG) E2 or F2 in gel form. The gel composition was as follows: 4% tylose MH 300, 2% glycerine, 1% chlorhexidine digluconate, 83% sterile distilled water and 10% PG stock solution. Both PGE2 and PGF2 gels were used. Final concentration was 2.5 mg E2 or 2.5 mg F2 per g of gel. Gel was applied via transcervical, extraamniotic polyethylene catheter every 2-3 hours. Results: PGE2-gel was used in 14 cases. After 3-4 applications both fetus and placenta were expelled. Average dose used was 4.6 mg E2/patient. First contractions started in 30 minutes; induction to expulsion time was 11 hours 35 minutes. F2-gel given to 6 patients resulted in expulsion of the fetus in all cases but placenta needed removal by curettage in 4 patients. Average dose per patient was 17.7 mg of F2; first contractions in 30 minutes, average expulsion time 17 hours 38 minutes. With both PGs there were painful contractions which were controlled with a combination of pentazocine and Valium. PGE2 caused vomiting in 5 patients. No increased bleeding or postabortion infection occurred. Follow-up curettage was done in all patients to ensure removal of all tissues. Overall evaluation of the PG-gels was considered good. PG stability in gel form is good; during 8 months of preservation in sterile aluminum tubes at -25 degrees Celsius no decline in clinical effectiveness was noted. The gel application is less expensive than the slow-injection pump method.

  6. Novel contraceptive targets to inhibit ovulation: the prostaglandin E2 pathway

    PubMed Central

    Duffy, Diane M.

    2015-01-01

    BACKGROUND Prostaglandin E2 (PGE2) is an essential intrafollicular regulator of ovulation. In contrast with the one-gene, one-protein concept for synthesis of peptide signaling molecules, production and metabolism of bioactive PGE2 requires controlled expression of many proteins, correct subcellular localization of enzymes, coordinated PGE2 synthesis and metabolism, and prostaglandin transport in and out of cells to facilitate PGE2 action and degradation. Elevated intrafollicular PGE2 is required for successful ovulation, so disruption of PGE2 synthesis, metabolism or transport may yield effective contraceptive strategies. METHODS This review summarizes case reports and studies on ovulation inhibition in women and macaques treated with cyclooxygenase inhibitors published from 1987 to 2014. These findings are discussed in the context of studies describing levels of mRNA, protein, and activity of prostaglandin synthesis and metabolic enzymes as well as prostaglandin transporters in ovarian cells. RESULTS The ovulatory surge of LH regulates the expression of each component of the PGE2 synthesis-metabolism-transport pathway within the ovulatory follicle. Data from primary ovarian cells and cancer cell lines suggest that enzymes and transporters can cooperate to optimize bioactive PGE2 levels. Elevated intrafollicular PGE2 mediates key ovulatory events including cumulus expansion, follicle rupture and oocyte release. Inhibitors of the prostaglandin-endoperoxide synthase 2 (PTGS2) enzyme (also known as cyclooxygenase-2 or COX2) reduce ovulation rates in women. Studies in macaques show that PTGS2 inhibitors can reduce the rates of cumulus expansion, oocyte release, follicle rupture, oocyte nuclear maturation and fertilization. A PTGS2 inhibitor reduced pregnancy rates in breeding macaques when administered to simulate emergency contraception. However, PTGS2 inhibition did not prevent pregnancy in monkeys when administered to simulate monthly contraceptive use. CONCLUSION

  7. Prostaglandin E2 stimulates a Ca2+-dependent K+ channel in human erythrocytes and alters cell volume and filterability.

    PubMed

    Li, Q; Jungmann, V; Kiyatkin, A; Low, P S

    1996-08-02

    To understand the mechanism by which human red blood cells (RBCs) contribute to hemostasis and thrombosis, we have examined the effects of metabolites released by activated platelets on intact RBCs. Prostaglandin E2 (PGE2), a signal molecule produced by activated platelets, was observed to lower the filterability of human erythrocytes by approximately 30% at 10(-10) M. PGE2 also caused a reduction in mean cell volume of approximately 10%. The shrinkage of red cells after PGE2 treatment was confirmed by documenting a decrease in osmotic fragility and an increase in cell density following exposure to the hormone. Careful analysis, however, revealed that only approximately 15% of the erythrocytes responded to stimulation with PGE2. Examination of the cause of cell shrinkage showed that induction of a PGE2-stimulated K+ efflux pathway leading to rapid loss of cellular K+ was responsible. The PGE2-stimulated K+ loss was also observed to be Ca2+-dependent, suggesting the possible involvement of the Gardos channel. Gardos channel participation was supported by the observation that two Gardos channel inhibitors, charybdotoxin and clotrimazole, independently blocked the PGE2-stimulated K+ efflux. Further evidence for Gardos channel activation came from experiments aimed at characterizing the efflux pathway followed by the obligatory counterion. Thus, K+ efflux was readily stimulated even when NO3- was substituted for Cl-, suggesting that neither KCl cotransport nor Na/K/2Cl cotransport plays a prominent role in the PGE2-induced cell shrinkage. Further, the anion transporter band 3 was implicated as the counterion efflux route, since DIDS inhibited the PGE2-stimulated cell volume change without blocking the change in membrane potential. Taken together, we propose that release of PGE2 by activated platelets constitutes part of a mechanism by which activated platelets may recruit adjacent erythrocytes to assist in clot formation.

  8. Prostaglandin E2 EP2 activation reduces memory decline in R6/1 mouse model of Huntington's disease by the induction of BDNF-dependent synaptic plasticity.

    PubMed

    Anglada-Huguet, Marta; Vidal-Sancho, Laura; Giralt, Albert; García-Díaz Barriga, Gerardo; Xifró, Xavier; Alberch, Jordi

    2016-11-01

    Huntington's disease (HD) patients and mouse models show learning and memory impairment even before the onset of motor symptoms. Deficits in hippocampal synaptic plasticity have been involved in the HD memory impairment. Several studies show that prostaglandin E2 (PGE2) EP2 receptor stimulates synaptic plasticity and memory formation. However, this role was not explored in neurodegenerative diseases. Here, we investigated the capacity of PGE2 EP2 receptor to promote synaptic plasticity and memory improvements in a model of HD, the R6/1 mice, by administration of the agonist misoprostol. We found that misoprostol increases dendritic branching in cultured hippocampal neurons in a brain-derived neurotrophic factor (BDNF)-dependent manner. Then, we implanted an osmotic mini-pump system to chronically administrate misoprostol to R6/1 mice from 14 to 18weeks of age. We observed that misoprostol treatment ameliorates the R6/1 long-term memory deficits as analyzed by the T-maze spontaneous alternation task and the novel object recognition test. Importantly, administration of misoprostol promoted the expression of hippocampal BDNF. Moreover, the treatment with misoprostol in R6/1 mice blocked the reduction in the number of PSD-95 and VGluT-1 positive particles observed in hippocampus of vehicle-R6/1 mice. In addition, we observed an increase of cAMP levels in the dentate ` of WT and R6/1 mice treated with misoprostol. Accordingly, we showed a reduction in the number of mutant huntingtin nuclear inclusions in the dentate gyrus of R6/1 mice. Altogether, these results suggest a putative therapeutic effect of PGE2 EP2 receptor in reducing cognitive deficits in HD. Copyright © 2016. Published by Elsevier Inc.

  9. Prostaglandin E2 promotes intestinal repair through an adaptive cellular response of the epithelium.

    PubMed

    Miyoshi, Hiroyuki; VanDussen, Kelli L; Malvin, Nicole P; Ryu, Stacy H; Wang, Yi; Sonnek, Naomi M; Lai, Chin-Wen; Stappenbeck, Thaddeus S

    2017-01-04

    Adaptive cellular responses are often required during wound repair. Following disruption of the intestinal epithelium, wound-associated epithelial (WAE) cells form the initial barrier over the wound. Our goal was to determine the critical factor that promotes WAE cell differentiation. Using an adaptation of our in vitro primary epithelial cell culture system, we found that prostaglandin E2 (PGE 2 ) signaling through one of its receptors, Ptger4, was sufficient to drive a differentiation state morphologically and transcriptionally similar to in vivo WAE cells. WAE cell differentiation was a permanent state and dominant over enterocyte differentiation in plasticity experiments. WAE cell differentiation was triggered by nuclear β-catenin signaling independent of canonical Wnt signaling. Creation of WAE cells via the PGE 2 -Ptger4 pathway was required in vivo, as mice with loss of Ptger4 in the intestinal epithelium did not produce WAE cells and exhibited impaired wound repair. Our results demonstrate a mechanism by which WAE cells are formed by PGE 2 and suggest a process of adaptive cellular reprogramming of the intestinal epithelium that occurs to ensure proper repair to injury. © 2016 The Authors.

  10. Withaferin A down-regulates lipopolysaccharide-induced cyclooxygenase-2 expression and PGE2 production through the inhibition of STAT1/3 activation in microglial cells.

    PubMed

    Min, Kyoung-Jin; Choi, Kyounghwa; Kwon, Taeg Kyu

    2011-08-01

    Microglia are the major immune effector cells in the brain, and microglia activated by injury and infection can produce inflammatory mediators. A number of studies have reported that withaferin A has anti-inflammatory functions. However, the effects of withaferin A on the microglial inflammatory response have not been investigated. Our results show that withaferin A inhibited lipopolysaccharide (LPS)-induced cyclooxygenase (COX)-2 mRNA and protein expression and prostaglandin E2 (PGE(2)) production in BV2 murine microglial cells. Withaferin A had no effect on LPS-induced Akt and ERK phosphorylation, but phosphorylation of p38 and JNK was slightly decreased by withaferin A. Withaferin A significantly inhibited LPS-induced STAT1 and STAT3 phosphorylation in a dose-dependent manner. Furthermore, withaferin A inhibited nuclear translocation of STAT1 and interferon-gamma activated sequence (GAS)-promoter activity. Taken together, these results suggest that withaferin A inhibits LPS-induced PGE(2) production and COX-2 expression, at least in part, by blocking STAT1 and STAT3 activation. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. [HTRF-based high-throughput PGE2 release prohibition model and application in discovering traditional Chinese medicine active ingredients].

    PubMed

    Bai, Zhi-Ru; Fei, Hong-Qiang; Li, Na; Cao, Liang; Zhang, Chen-Feng; Wang, Tuan-Jie; Ding, Gang; Wang, Zhen-Zhong; Xiao, Wei

    2016-02-01

    Prostaglandin (PG) E2 is an active substance in pathological and physiological mechanisms, such as inflammation and pain. The in vitro high-throughput assay for screening the inhibitors of reducing PEG2 production is a useful method for finding out antiphlogistic and analgesic candidates. The assay was based on LPS-induced PGE2 production model using a homogeneous time-resolved fluorescence(HTRF) PGE2 testing kit combined with liquid handling automation and detection instruments. The critical steps, including the cell density optimization and IC50 values determination of a positive compound, were taken to verify the stability and sensibility of the assay. Low intra-plate, inter-plate and day-to-day variability were observed in this 384-well, high-throughput format assay. Totally 5 121 samples were selected from the company's traditional Chinese medicine(TCM) material base library and used to screen PGE2 inhibitors. In this model, the cell plating density was 2 000 cells for each well; the average IC₅₀ value for positive compounds was (7.3±0.1) μmol; the Z' factor for test plates was more than 0.5 and averaged at 0.7. Among the 5 121 samples, 228 components exhibited a PGE2 production prohibition rate of more than 50%, and 23 components exhibited more than 80%. This model reached the expected standards in data stability and accuracy, indicating the reliability and authenticity of the screening results. The automated screening system was introduced to make the model fast and efficient, with a average daily screening amount exceeding 14 000 data points and provide a new model for discovering new anti-inflammatory and analgesic drug and quickly screening effective constituents of TCM in the early stage. Copyright© by the Chinese Pharmaceutical Association.

  12. Canine mesenchymal stem cells treated with TNF-α and IFN-γ enhance anti-inflammatory effects through the COX-2/PGE2 pathway.

    PubMed

    Yang, Hye-Mi; Song, Woo-Jin; Li, Qiang; Kim, Su-Yeon; Kim, Hyeon-Jin; Ryu, Min-Ok; Ahn, Jin-Ok; Youn, Hwa-Young

    2018-05-14

    Mesenchymal stem cells (MSCs) have been used in studies on treatment of various diseases, and their application to immune-mediated diseases has garnered interest. Various methods for enhancing the immunomodulation effect of human MSCs have been used; however, similar approaches for canine MSCs are relatively unexplored. Accordingly, we evaluated immunomodulatory effects and mechanisms in canine MSCs treated with TNF-α and IFN-γ. Lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were incubated with the conditioned media (CM) from canine MSCs for 48 h. Expression of RNA was assessed by quantitative reverse transcription PCR (qRT-PCR), and protein levels were assessed by western blot. Expression of inducible nitric oxide synthase (iNOS), IL-6 and IL-1β was significantly (one-way ANOVA) decreased in LPS-stimulated RAW 264.7 cells incubated with CM from canine MSCs compared to that in LPS-stimulated RAW 264.7 cells alone. Furthermore, anti-inflammatory effects of TNF-α- and IFN-γ-primed canine MSCs were significantly increased compared with those of naïve canine MSCs. Expression of cyclooxygenase 2 (COX-2) and prostaglandin E 2 (PGE 2 ) were likewise significantly increased in primed canine MSCs. The level of iNOS protein in LPS-stimulated RAW 264.7 cells incubated with CM from the primed canine MSCs was decreased, but it increased when the cells were treated with NS-398(PGE 2 inhibitor). In conclusion, compared with naïve canine MSCs, cells primed with TNF-α and IFN-γ cause a greater reduction in release of anti-inflammatory cytokines from LPS-stimulated RAW 264.7 cells; the mechanism is upregulation of the COX-2/PGE 2 pathway. Copyright © 2018. Published by Elsevier Ltd.

  13. Anti-cancer Effects of a Novel Quinoline Derivative 83b1 on Human Esophageal Squamous Cell Carcinoma through Down-Regulation of COX-2 mRNA and PGE2.

    PubMed

    Pun, Ivan Ho Yuen; Chan, Dessy; Chan, Sau Hing; Chung, Po Yee; Zhou, Yuan Yuan; Law, Simon; Lam, Alfred King Yin; Chui, Chung Hin; Chan, Albert Sun Chi; Lam, Kim Hung; Tang, Johnny Cheuk On

    2017-01-01

    83b1 is a novel quinoline derivative that has been shown to inhibit cancer growth in human esophageal squamous cell carcinoma (ESCC). This study was conducted to comprehensively evaluate the cytotoxic effects of 83b1 on a series of ESCC cell lines and investigate the mechanisms by which 83b1 suppresses cancer growth based on molecular docking analysis. A series of ESCC and nontumor immortalized cell lines were exposed to 83b1 and cisplatin (CDDP) in a dose-dependent manner, and the cytotoxicity was examined by a MTS assay kit. Prediction of the molecular targets of 83b1 was conducted by molecular docking analysis. Expression of cyclooxygenase 2 (COX-2) mRNA and COX-2-derived prostaglandin E 2 (PGE 2 ) were measured by quantitative real-time polymerase chain reaction and enzymelinked immuno-sorbent assay, respectively. In vivo anti-tumor effect was determined using a nude mice xenografted model transplanted with an ESCC cell line, KYSE-450. 83b1 showed the significant anti-cancer effects on all ESCC cell lines compared to CDDP; however, 83b1 revealed much lower toxic effects on non-tumor cell lines than CDDP. The predicted molecular target of 83b1 is peroxisome proliferator-activated receptor delta (PPARδ), which is a widely known oncoprotein. Additionally the expression of COX-2 mRNA and COX-2-derived PGE 2 were down-regulated by 83b1 in a dose-dependent manner in ESCC cell lines. Furthermore, 83b1 was shown to significantly reduce the tumor size in nude mice xenograft. The results of this study suggest that the potential anti-cancer effects of 83b1 on human esophageal cancers occur through the possible oncotarget, PPARδ, and down-regulation of the cancer related genes and molecules.

  14. Circadian and estral changes in the hypothalamic prostaglandin e content and [h]prostaglandin e binding in female rats.

    PubMed

    Bommelaer-Bayet, M C; Wisner, A; Renard, C A; Levi, F A; Dray, F

    1990-04-01

    Abstract Prostaglandin E(2), (PGE(2)) is involved in the luteinizing hormone-releasing hormone-stimulated luteinizing hormone surge in female rats and may act via specific membrane receptors. The following studies were performed to determine whether there were any changes in the hypothalamic PGE(2) binding and/or PGE(2) content which were specific to proestrus and not to the rest of the estrous cycle. Groups of female Wistar rats were sacrificed at 3-h intervals throughout the estrous cycle to determine both the circadian and circaestral changes in the hypothalamic PGE(2) content and [(3)H]PGE(2) binding. The hypothalamic PGE(2) content was maximal at 1700 h on each of the 4 consecutive days of the estrous cycle but was independent of the stage of the cycle. [(3)H]PGE(2) binding also displayed a circadian rhythm; the lowest binding occurred near the circadian peak of PGE(2), suggesting that the PGE(2) binding sites were occupied by endogenous PGE(2). Since such circadian rhythms were not observed in the hypothalamus of male rats, they may be under the control of ovarian steroids. Also, since PGE(2) binding and the PGE(2) content both exhibit a diurnal pattern independent of the day of the cycle, there may be changes in the PGE(2) receptor-mediated process coupled to an adenylyl cyclase which could explain the luteinizing hormone surge in proestrus.

  15. 16,16-Dimethyl prostaglandin E2 increases survival in mice following irradiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Walden, T.L. Jr.; Patchen, M.; Snyder, S.L.

    1987-03-01

    16,16-Dimethyl prostaglandin E2 (DiPGE2), a stable analog of PGE2, increases the LD50/30 survival in CD2F1 male mice when given prior to ionizing radiation. Subcutaneous administration of 40 micrograms of DiPGE2 30 min prior to /sup 60/Co gamma irradiation extends the LD50/30 from 9.39 Gy in the control animals to 16.14 Gy in DiPGE2 treated, with a dose reduction factor of 1.72 (95% confidence limits: 1.62, 1.82). The degree of protection is dependent on both the time of administration and the dose of the prostaglandin. Ten micrograms administered 5 min prior to receiving a lethal dose of 10 Gy provides 90%more » survival but only 10% survival if administered 30 min prior to irradiation. Experiments to determine the in vivo concentration of DiPGE2 in organs postinjection show increased levels over time, but these are not correlated with protection. At 30 min after injection, as much as 80% of the DiPGE2 present in the spleen and plasma is unmetabolized. These results suggest that the protection results from the physiologic action of DiPGE2 rather than direct in vivo detoxification of radicals.« less

  16. Elevated interleukin 6 is induced by prostaglandin E2 in a murine model of inflammation: possible role of cyclooxygenase-2.

    PubMed Central

    Hinson, R M; Williams, J A; Shacter, E

    1996-01-01

    Injection of mineral oils such as pristane into the peritoneal cavities of BALB/c mice results in a chronic peritonitis associated with high tissue levels of interleukin 6 (IL-6). Here we show that increased prostaglandin E2 (PGE2) synthesis causes induction of IL-6 and that expression of an inducible cyclooxygenase, Cox-2, may mediate this process. Levels of both PGE2 and IL-6 are elevated in inflammatory exudates from pristane-treated mice compared with lavage samples from untreated mice. The Cox-2 gene is induced in the peritoneal macrophage fraction isolated from the mice. A cause and effect relationship between increased macrophage PGE2 and IL-6 production is shown in vitro. When peritoneal macrophages are activated with an inflammatory stimulus (polymerized albumin), the Cox-2 gene is induced and secretion of PGE2 and IL-6 increases, with elevated PGE2 appearing before IL-6. Cotreatment with 1 microM indomethacin inhibits PGE2 production by the cells and reduces the induction of IL-6 mRNA but has no effect on Cox-2 mRNA, consistent with the fact that the drug inhibits catalytic activity of the cyclooxygenase but does not affect expression of the gene. Addition of exogenous PGE2 to macrophages induces IL-6 protein and mRNA synthesis, indicating that the eicosanoid stimulates IL-6 production at the level of gene expression. PGE2-stimulated IL-6 production is unaffected by addition of indomethacin. Taken together with the earlier finding that indomethacin diminishes the elevation of IL-6 in pristane-treated mice, the results show that PGE2 can induce IL-6 production in vivo and implicate expression of the Cox-2 gene in the regulation of this cytokine. Images Fig. 2 Fig. 4 Fig. 5 Fig. 6 Fig. 8 PMID:8643498

  17. Endothelial E-type prostanoid 4 receptors promote barrier function and inhibit neutrophil trafficking.

    PubMed

    Konya, Viktoria; Üllen, Andreas; Kampitsch, Nora; Theiler, Anna; Philipose, Sonia; Parzmair, Gerald P; Marsche, Gunther; Peskar, Bernhard A; Schuligoi, Rufina; Sattler, Wolfgang; Heinemann, Akos

    2013-02-01

    Increased vascular permeability is a fundamental characteristic of inflammation. Substances that are released during inflammation, such as prostaglandin (PG) E(2), can counteract vascular leakage, thereby hampering tissue damage. In this study we investigated the role of PGE(2) and its receptors in the barrier function of human pulmonary microvascular endothelial cells and in neutrophil trafficking. Endothelial barrier function was determined based on electrical impedance measurements. Neutrophil recruitment was assessed based on adhesion and transendothelial migration. Morphologic alterations are shown by using immunofluorescence microscopy. We observed that activation of E-type prostanoid (EP) 4 receptor by PGE(2) or an EP4-selective agonist (ONO AE1-329) enhanced the barrier function of human microvascular lung endothelial cells. EP4 receptor activation prompted similar responses in pulmonary artery and coronary artery endothelial cells. These effects were reversed by an EP4 antagonist (ONO AE3-208), as well as by blocking actin polymerization with cytochalasin B. The EP4 receptor-induced increase in barrier function was independent of the classical cyclic AMP/protein kinase A signaling machinery, endothelial nitric oxide synthase, and Rac1. Most importantly, EP4 receptor stimulation showed potent anti-inflammatory activities by (1) facilitating wound healing of pulmonary microvascular endothelial monolayers, (2) preventing junctional and cytoskeletal reorganization of activated endothelial cells, and (3) impairing neutrophil adhesion to endothelial cells and transendothelial migration. The latter effects could be partially attributed to reduced E-selectin expression after EP4 receptor stimulation. These data indicate that EP4 agonists as anti-inflammatory agents represent a potential therapy for diseases with increased vascular permeability and neutrophil extravasation. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc

  18. Oxytocin and tumor necrosis factor alpha stimulate expression of prostaglandin E2 synthase and secretion of prostaglandin E2 by luminal epithelial cells of the porcine endometrium during early pregnancy.

    PubMed

    Waclawik, Agnieszka; Blitek, Agnieszka; Ziecik, Adam J

    2010-10-01

    Oxytocin (OXT) and tumor necrosis factor α (TNF) have been implicated in the control of luteolysis by stimulating endometrial secretion of luteolytic prostaglandin F(2α) (PGF(2α)). Nevertheless, OXT concentration in porcine uterine lumen increases markedly on days 11-12 of pregnancy, and TNF is expressed in endometrium during pregnancy. The objective of the study was to determine the effect of OXT and TNF on expression of the enzymes involved in PG synthesis: PG-endoperoxide synthase 2 (PTGS2), PGE(2) synthase (mPGES-1) and PGF synthase, and PGE(2) receptor (PTGER2), as well as on PG secretion by endometrial luminal epithelial cells (LECs) on days 11-12 of the estrous cycle and pregnancy. LECs isolated from gilts on days 11-12 of the estrous cycle (n=8) and pregnancy (n=7) were treated with OXT (100  nmol/l) and TNF (0.6  nmol/l) for 24  h. OXT increased PTGS2 mRNA and mPGES-1 protein contents, as well as PGE(2) secretion but only on days 11-12 of pregnancy. TNF stimulated PTGS2 and mPGES-1 mRNA, as well as mPGES-1 protein expression and PGE(2) release on days 11-12 of pregnancy and the estrous cycle. In addition, expressions of PTGER2 and PTGER4 were determined in corpus luteum (CL). Abundance of PTGER2 mRNA and PTGER4 protein in CL was upregulated on day 14 of pregnancy versus day 14 of the estrous cycle. This study indicates that TNF and OXT regulate PGE(2) synthesis in LECs during early pregnancy. PGE(2) secreted by LECs, after reaching ovaries, could have a luteoprotective effect through luteal PTGER2 and PTGER4, or may directly promote uterine function and conceptus development.

  19. Acute Effects of Prostaglandin E1 and E2 on Vascular Reactivity and Blood Flow in situ in the Chick Chorioallantoic Membrane

    PubMed Central

    Fay, K.; Dunn, B.E.; Gruenloh, S.K.; Narayanan, J.; Jacobs, E.R.; Medhora, M.

    2013-01-01

    1. The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE1&2 for vascular effects and signaling in the CAM. Application of PGE1&2 induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP2-4, and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP3 and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo. PMID:22858445

  20. Identification of Francisella novicida mutants that fail to induce prostaglandin E2 synthesis by infected macrophages

    PubMed Central

    Woolard, Matthew D.; Barrigan, Lydia M.; Fuller, James R.; Buntzman, Adam S.; Bryan, Joshua; Manoil, Colin; Kawula, Thomas H.; Frelinger, Jeffrey A.

    2013-01-01

    Francisella tularensis is the causative agent of tularemia. We have previously shown that infection with F. tularensis Live Vaccine Strain (LVS) induces macrophages to synthesize prostaglandin E2 (PGE2). Synthesis of PGE2 by F. tularensis infected macrophages results in decreased T cell proliferation in vitro and increased bacterial survival in vivo. Although we understand some of the biological consequences of F. tularensis induced PGE2 synthesis by macrophages, we do not understand the cellular pathways (neither host nor bacterial) that result in up-regulation of the PGE2 biosynthetic pathway in F. tularensis infected macrophages. We took a genetic approach to begin to understand the molecular mechanisms of bacterial induction of PGE2 synthesis from infected macrophages. To identify F. tularensis genes necessary for the induction of PGE2 in primary macrophages, we infected cells with individual mutants from the closely related strain F. tularensis subspecies novicida U112 (U112) two allele mutant library. Twenty genes were identified that when disrupted resulted in U112 mutant strains unable to induce the synthesis of PGE2 by infected macrophages. Fourteen of the genes identified are located within the Francisella pathogenicity island (FPI). Genes in the FPI are required for F. tularensis to escape from the phagosome and replicate in the cytosol, which might account for the failure of U112 with transposon insertions within the FPI to induce PGE2. This implies that U112 mutant strains that do not grow intracellularly would also not induce PGE2. We found that U112 clpB::Tn grows within macrophages yet fails to induce PGE2, while U112 pdpA::Tn does not grow yet does induce PGE2. We also found that U112 iglC::Tn neither grows nor induces PGE2. These findings indicate that there is dissociation between intracellular growth and the ability of F. tularensis to induce PGE2 synthesis. These mutants provide a critical entrée into the pathways used in the host for PGE2

  1. Mycophenolate mofetil decreases endothelial prostaglandin E2 in response to allogeneic T cells or cytokines.

    PubMed

    Blaheta, R A; Nelson, K; Oppermann, E; Leckel, K; Harder, S; Cinatl, J; Weber, S; Shipkova, M; Encke, A; Markus, B H

    2000-05-15

    Prostaglandin E2 (PGE2) is a powerful endogenous immune suppressant and interferes with various T-cell functions. However, it is not known in detail whether immunosuppressive drugs influence the PGE2-driven immune response in transplant patients. Therefore, we investigated the effect of several immunosuppressive compounds, in particular the novel drug mycophenolate mofetil (MMF), on endothelial PGE2 release. Endothelial cells (HUVEC) were activated by either allogeneic CD4+ or CD8+ T cells, or by the cytokines interleukin-1 or gamma-interferon. Using an enzyme-linked immunosorbent assay, we analyzed PGE2 release of the activated HWEC in the presence of MMF, cyclosporine, or tacrolimus. As verapamil and mibefradil also possess immunosuppressive properties, they were included in the study as well. Activation of HUVEC with interleukin-1 or T cells resulted in a drastic accumulation of PGE2 in the supernatant. Cyclosporine or tacrolimus had no effect on PGE2 release. However, Ca2+ channel blockers, when applied at higher dosages, caused a significant increase in PGE2. Interestingly, MMF strongly diminished the PGE2 level in the cell culture supernatant in a concentration-dependent manner. The results demonstrate an inhibitory effect of MMF on PGE2 production, which may lower the benefits of the PGE2-triggered immune response after organ transplantation.

  2. Effect of prostaglandin E2 on cytotoxic activity and granzyme A protease release by murine adherent IL-2 activated killer cells.

    PubMed

    Vaillier, D; Daculsi, R; Gualde, N

    1994-04-01

    The effects of prostaglandin E2 (PGE2) have been studied on a highly purified population of murine IL-2 activated killer cells obtained by selecting plastic-adherent splenocytes (AK cells) after incubation with high doses of recombinant IL-2. AK cells were highly cytotoxic for YAC-1 target cells. The cytotoxic activity was detectable at one hour after initiation of the cytotoxic assay and then increased with time. Cytotoxic activity of AK cells was inhibited by the addition of PGE2 or forskolin during the cytotoxic assay. When AK cells were generated in the presence of PGE2, the yielding cytotoxic activity was lower than the one expressed by "regular" AK cells but were insensitive to the inhibitory effect of PGE2 even if their lytic capability was still suppressed by forskolin. The presence of PGE2 during the AK cell culture had no effect on the cellular proliferation. Moreover, using tetrazolium-based colorimetric assay which reflects the cellular activation, it was observed that AK cells cultured in presence of PGE2 had an increased capacity to cleave the tetrazolium salt to formazan. Since the cytotoxic activity of killer cells is related to expression of serine esterase enzymes we evaluated the effects of PGE2 on serine esterase (Granzyme A) release after one hour of incubation of AK cells either alone or in presence of PGE2, YAC-1 cells or both. We observed that (i) AK cells spontaneously release granzyme A, (ii) the level of granzyme A was significantly increased when AK cells were incubated either with YAC-1 cells or PGE2 but did not change when YAC-1 cells and PGE2 were both associated with AK cells.

  3. Colonic Saturated Fatty Acid Concentrations and Expression of COX-1, but not Diet, Predict Prostaglandin E2 in Normal Human Colon Tissue.

    PubMed

    Sidahmed, ElKhansa; Sen, Ananda; Ren, Jianwei; Patel, Arsh; Turgeon, D Kim; Ruffin, Mack T; Brenner, Dean E; Djuric, Zora

    2016-10-01

    Prostaglandin E2 (PGE2) in the colon is a pro-inflammatory mediator that is associated with increased risk of colon cancer. In this study, expression of genes in the PGE2 pathway were quantified in colon biopsies from a trial of a Mediterranean versus a Healthy Eating diet in 113 individuals at high risk for colon cancer. Colon biopsies were obtained before and after 6 months of intervention. Quantitative, real-time PCR was used to measure mRNA expression of prostaglandin H synthases (PTGS1 and 2), prostaglandin E synthases (PTGES1 and 3), prostaglandin dehydrogenase (HPGD), and PGE2 receptors (PTGER2, PTGER4). The most highly expressed genes were HPGD and PTGS1. In multivariate linear regression models of baseline data, both colon saturated fatty acid concentrations and PTGS1 expression were significant, positive predictors of colon PGE2 concentrations after controlling for nonsteroidal anti-inflammatory drug use, gender, age, and smoking status. The effects of dietary intervention on gene expression were minimal with small increases in expression noted for PTGES3 in both arms and in PTGER4 in the Mediterranean arm. These results indicate that short-term dietary change had little effect on enzymes in the prostaglandin pathway in the colon and other factors, such as differences in fatty acid metabolism, might be more influential.

  4. Effects of Prostaglandin E2 and Risedronate Administration on Cancellous Bone in Older Female Rats

    NASA Technical Reports Server (NTRS)

    Lin, B. Y.; Jee, W. S. S.; Ma, Y. F.; Ke, H. Z.; Kimmel, D. B.; Li, X. J.

    1994-01-01

    The effects of Prostaglandin E2 (PGE2) and Risedronate (Ris) both separately and in combination (PGE2 + Ris) were studied on the intact aged female rat skeleton to determine whether the combination of PGE2 with an antiresorptive agent is more effective anabolically than PGE2 alone. Nine month-old Sprague-Dawley rats were injected subcutaneously either with vehicle, 6 mg PGE2/kg per day, 1 or 5 microgram Ris/kg twice a week, or 6 mg PGE2/kg per day plus 1 or 5 microgram Ris/kg twice a week (PGE2 + 1 Ris or PGE2 + 5 Ris) for 60 days. After the treatment, we determined the longitudinal bone growth rate, the qualitative appearance of the primary spongiosa (PS), and the static and dynamic bone histomorphometry of the secondary spongiosa (SS) of the proximal tibial metaphysis (PTM) by examining undecalcified longitudinal sections after double fluorescent labeling. The relative effects of these treatments on longitudinal bone growth were ranked as follows: PGE2 + 5 Ris greater than PGE2 + 1 Ris = basal greater than PGE2 greater than 1 microgram Ris = 5 microgram Ris = aging. The density of the PS was ranked as follows: PGE2 + 5 Ris greater than PGE2 + 1 Ris = PGE2 = 5 microgram Ris = 1 microgram Ris greater than basal = aging. The increase in density of the PS was the result of stimulated longitudinal growth and the action of bisphosphonate. Bone mass in the SS was ranked as follows: PGE2 + 5 Ris = PGE2 + 1 Ris = PGE2 greater than 5 microgram Ris = 1 microgram Ris = aging = basal. However, PGE2 alone and its cotreatment with Ris accumulated bone by different tissue mechanisms. PGE2 alone created new bone by increasing activation frequency 8.3-fold and the formation to resorption ratio 1.3-fold from the controls. The combination of PGE2 and Ris depressed activation frequency (-54% to -74%), and bone formation rate (tissue-based -31%, and bone-based -42%) and eroded surface (-79% to -81%), so as to increase the formation to resorption ratio (three- to four-fold) over PGE2

  5. Inhibition by prostaglandin E(2) of anaphylatoxin C5a- but not zymosan-induced prostanoid release from rat Kupffer cells.

    PubMed

    Pestel, Sabine; Jungermann, Kurt; Götze, Otto; Schieferdecker, Henrike L

    2002-04-01

    The proinflammatory anaphylatoxin C5a induces the release of prostanoids, ie, prostaglandins (PG) and thromboxane (TX), from the resident liver macrophages (Kupffer cells [KC]). Because KC themselves express prostanoid receptors, prostanoids--besides having paracrine functions--might regulate their own release in an autocrine loop. So far, such a possible feedback regulation has not been investigated systematically, probably because of methodological difficulties to measure newly synthesized prostanoids in the presence of added prostanoids. Here, after prelabeling of phospholipids with [(14)C]arachidonate, cellularly formed [(14)C]prostanoids were determined in the presence of added unlabelled prostanoids by thin layer chromatography. In cultured KC, recombinant rat C5a (rrC5a) rapidly increased PGD(2), PGE(2), and TXA(2) release, which was strongly reduced by PGE(2), but neither by PGD(2) nor by the TXA(2) analog U46619. The inhibitory effect of PGE(2) was mimicked by cAMP, indicating that the G(s)-coupled PGE(2) receptors type 2 or 4 were involved. Zymosan also enhanced prostanoid release from KC, but with slightly slower kinetics; this action was neither inhibited by PGE(2) nor by cAMP. Also in perfused rat livers, rrC5a enhanced prostanoid release from KC as shown by prostanoid overflow and thereby indirectly increased glucose output from hepatocytes. Again, PGE(2), but not PGD(2), inhibited rrC5a-elicited prostanoid overflow. This resulted in a complete inhibition of rrC5a-induced, prostanoid-mediated glucose output. Thus, PGE(2) can inhibit specifically the C5a-induced prostanoid release from KC via a feedback mechanism and thereby limit prostanoid-mediated hepatocellular defense reactions, eg, glucose release.

  6. Antagonistic effects of acetylshikonin on LPS-induced NO and PGE2 production in BV2 microglial cells via inhibition of ROS/PI3K/Akt-mediated NF-κB signaling and activation of Nrf2-dependent HO-1.

    PubMed

    Jayasooriya, Rajapaksha Gedara Prasad Tharanga; Lee, Kyoung-Tae; Choi, Yung Hyun; Moon, Sung-Kwon; Kim, Wun-Jae; Kim, Gi-Young

    2015-10-01

    Although acetylshikonin (ACS) is known to have antioxidant and antitumor activities, whether ACS regulates the expression of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated microglial cells remains unclear. In this study, it was found that ACS isolated from Lithospermum erythrorhizon inhibits LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) release by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in BV2 microglial cells. Furthermore, ACS reduced the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) and subsequently suppressed iNOS and COX-2 expression. Consistent with these data, ACS attenuated the phosphorylation of PI3K and Akt and suppressed the DNA-binding activity of NF-κB by inducing the generation of reactive oxygen species (ROS) in LPS-stimulated cells. In addition, ACS enhanced heme oxygenase-1 (HO-1) expression via nuclear factor-erythroid 2-related factor 2 (Nrf2) activation. Zinc protoporphyrin, a specific HO-1 inhibitor, partially attenuated the antagonistic effects of ACS on LPS-induced NO and PGE2 production. By contrast, the presence of cobalt protoporphyrin, a specific HO-1 inducer, potently suppressed LPS-induced NO and PGE2 production. These data indicate that ACS downregulates proinflammatory mediators such as NO and PGE2 by suppressing PI3K/Akt-dependent NF-κB activity induced by ROS as well as inducing Nrf2-dependent HO-1 activity. Taken together, ACS might be a good candidate to regulate LPS-mediated inflammatory diseases.

  7. Heterogeneity of murine adherent interleukin-2-activated killer cells. Differential effect of prostaglandin E2 and forskolin.

    PubMed

    Vaillier, D; Daculsi, R; Gualde, N

    1995-01-01

    We have studied the relationship between cytotoxic activity, size and granularity of murine interleukin-2-activated adherent killer cells issued from spleen cells cultured with high levels of IL-2. The effects of prostaglandin E2 (PGE2) and forskolin upon these cells were assessed. All adherent spleen cells obtained after 5 days of culture were large granular lymphocytes but presented a heterogeneity in size and granularity. After fractionation on a discontinuous-density Percoll gradient, four cellular subpopulations were isolated. Fluorescence-activated cell sorting analysis showed that cells of the lightest fraction (F1) were the largest, while the cells found in the heaviest fraction (F4) were much more granular than the cells collected in the two intermediate fractions (F2 and F3). The serine esterases level was higher in F4 than in unfractionated cells and diminished to about 40% in cells of fractions F2 and F3, which expressed a cytotoxic activity against YAC-1 cells higher than that in unfractionated cells or in F1 or F4, which presented the lowest cytotoxic activity. When AK cells were cultured for 48 h in the presence of either PGE2 or forskolin, which induce an intracellular increase of cAMP, we observed that PGE2 (1 microM) inhibited the cytotoxic activity, but surprisingly forskolin (2 microM) exerted a stimulating effect on the induction of cytotoxic activity. After fractionation on a discontinuous Percoll gradient we observed the same cellular distribution among PGE2 or forskolin-treated or -untreated cells, but PGE2 induced an increase of size and granularity. This effect of PGE2 was more potent on the cells collected in F4. However this variation of granularity was not associated with any variation in the serine esterase level. The cytotoxic activity of PGE2- or forskolin-treated cells did not present any significant variation relative to the control for cells collected in F2 and F3; on the other hand, forskolin-treated cells collected in F4 showed

  8. The Aryl Hydrocarbon Receptor Binds to E2F1 and Inhibits E2F1-induced Apoptosis

    PubMed Central

    Marlowe, Jennifer L.; Fan, Yunxia; Chang, Xiaoqing; Peng, Li; Knudsen, Erik S.; Xia, Ying

    2008-01-01

    Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr−/− fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, γH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of E2F1 expression. In contrast, ligand-dependent AHR activation protects these cells from etoposide-induced cell death. In cells expressing both proteins, AHR and E2F1 interact independently of the retinoblastoma protein (RB), because AHR and E2F1 coimmunoprecipitate from extracts of RB-negative cells. Additionally, chromatin immunoprecipitation assays indicate that AHR and E2F1 bind to the Apaf1 promoter at a region containing a consensus E2F1 binding site but no AHR binding sites. AHR activation represses Apaf1 and TAp73 mRNA induction by a constitutively active CHK2 expression vector. Furthermore, AHR overexpression blocks the transcriptional induction of Apaf1 and p73 and the accumulation of sub-G0/G1 cells resulting from ectopic overexpression of E2F1. These results point to a proproliferative, antiapoptotic function of the Ah receptor that likely plays a role in tumor progression. PMID:18524851

  9. PTGS-2-PTGER2/4 signaling pathway partially protects from diabetogenic toxicity of streptozotocin in mice.

    PubMed

    Vennemann, Antje; Gerstner, Anemone; Kern, Niklas; Ferreiros Bouzas, Nerea; Narumiya, Shuh; Maruyama, Takayuki; Nüsing, Rolf M

    2012-07-01

    Prostanoids are suggested to participate in diabetes pathology, but their roles are controversially discussed. The purpose of the current study was to examine the role of cyclooxygenase (prostaglandin synthase [PTGS]) enzymes and prostaglandin (PG) E(2) signaling pathways in streptozotocin (STZ)-induced type 1 diabetes. Blood glucose, insulin, and survival rate were studied in mice with targeted disruption of the genes for PTGS and PGE receptors (PTGERs). PGE(2) was found as the main prostanoid formed by the pancreas. Contrarily to PTGS-1, deficiency of PTGS-2 activity significantly amplified STZ effect, causing dramatic loss of insulin production and rise in blood glucose and death rate. STZ metabolism was unaffected by PTGS deficiency. Diabetogenicity of STZ in PTGER1(-/-), PTGER2(-/-), PTGER3(-/-), and PTGER4(-/-) mice was comparable to control mice. In striking contrast, combined knockout of PTGER2 and PTGER4 by blocking PTGER4 in PTGER2(-/-) mice strongly enhanced STZ pathology. Treatment of PTGS-2(-/-) and wild-type mice with PTGER2/PTGER4 agonists partially protected against STZ-induced diabetes and restored β-cell function. Our data uncover a previously unrecognized protective role of PTGS-2-derived PGE(2) in STZ-induced diabetes mediated by the receptor types PTGER2 and PTGER4. These findings offer the possibility to intervene in early progression of type 1 diabetes by using PTGER-selective agonists.

  10. Autocrine prostaglandin E2 signaling promotes promonocytic leukemia cell survival via COX-2 expression and MAPK pathway

    PubMed Central

    Lee, Jaetae; Lee, Young Sup

    2015-01-01

    The COX-2/PGE2 pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, PGE2, in cancer survival remain unknown. Herein, we investigated PGE2-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with PGE2 activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. PGE2 not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of PGE2, and restored the menadione-induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the PGE2-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that PGE2 signaling acts in an autocrine manner, and specific inhibition of PGE2 will provide a novel approach for the treatment of leukemia. [BMB Reports 2015; 48(2): 109-114] PMID:24965577

  11. Modulation of NF-κB activation by resveratrol in LPS treated human intestinal cells results in downregulation of PGE2 production and COX-2 expression.

    PubMed

    Cianciulli, Antonia; Calvello, Rosa; Cavallo, Pasqua; Dragone, Teresa; Carofiglio, Vito; Panaro, Maria Antonietta

    2012-10-01

    Resveratrol is a natural phytoalexin present in a variety of plant species, such as grapes and red wine, that is well known for its anti-inflammatory effects. In addition, a cancer chemotherapeutic activity of resveratrol has been described. Here we evaluated the effect of resveratrol on COX-2 and prostaglandin E(2) production in human intestinal cells Caco-2 cells treated with lipopolysaccharide (LPS). Resveratrol concentration-dependently inhibited the expression of COX-2 mRNA in the LPS-treated cells, as well as protein expression, resulting in a decreased production of PGE(2). In order to investigate the mechanisms through which resveratrol exhibited these anti-inflammatory effects, we examined the activation of IκB in LPS-stimulated intestinal cells. Results demonstrated that resveratrol inhibited the translocation of NF-κB p65 subunits from the cytosol to the nucleus, which correlated with its inhibitory effects on IκBα phosphorylation and degradation. These results suggest that the down-regulation of COX-2 and PGE(2) by resveratrol may be related to NF-κB inhibition through the negative regulation of IKK phosphorylation in intestinal cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Prostaglandin E2 Receptor Expression by Osteoblasts is Modulated by Implant Surface Roughness and Prostaglandin E2

    DTIC Science & Technology

    2006-05-01

    al. 1996; Trancik et al. 1989). Thus, it is of vital importance to the field of dental implantology to investigate how prostaglandins mediate their...of Texas Graduate School of Biomedical Sciences at San Antonio Supervising Professor: David D. Dean, Ph.D. While the predictability of dental implants...control media lacking PGE2. Cells were incubated for an additional 3, 6, or 120 hrs to simulate the early response after dental implant placement, after

  13. Promoter-dependent and -independent activation of insulin-like growth factor binding protein-5 gene expression by prostaglandin E2 in primary rat osteoblasts

    NASA Technical Reports Server (NTRS)

    McCarthy, T. L.; Casinghino, S.; Mittanck, D. W.; Ji, C. H.; Centrella, M.; Rotwein, P.

    1996-01-01

    Insulin-like growth factor (IGF) action is mediated by high affinity cell surface IGF receptors and modulated by a family of secreted IGF binding proteins (IGFBPs). IGFBP-5, the most conserved of six IGFBPs characterized to date, uniquely potentiates the anabolic actions of IGF-I for skeletal cells. In osteoblasts, IGFBP-5 production is stimulated by prostaglandin E2 (PGE2), a local factor that mediates certain effects induced by parathyroid hormone, cytokines such as interleukin-1 and transforming growth factor-beta, and mechanical strain. In this study, we show that transcriptional and post-transcriptional events initiated by PGE2 collaborate to enhance IGFBP-5 gene expression in primary fetal rat osteoblast cultures. PGE2 treatment stimulated up to a 7-fold rise in steady-state levels of IGFBP-5 mRNA throughout 32 h of incubation. Analysis of nascent IGFBP-5 mRNA suggested that PGE2 had only a modest stimulatory effect on IGFBP-5 gene transcription, and transient transfection studies with IGFBP-5 promoter-reporter genes confirmed that PGE2 enhanced promoter activity by approximately 2-fold. Similar stimulatory effects were seen with forskolin. A DNA fragment with only 51 base pairs of the 5'-flanking sequence retained hormonal responsiveness, which may be mediated by a binding site for transcription factor AP-2 located at positions -44 to -36 in the proximal IGFBP-5 promoter. Incubation of osteoblasts with the mRNA transcriptional inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole demonstrated that PGE2 enhanced IGFBP-5 mRNA stability by 2-fold, increasing the t1/2 from 9 to 18 h. The effects of PGE2 on steady-state IGFBP-5 transcripts were abrogated by preincubating cells with cycloheximide, indicating that the effects of PGE2 on both gene transcription and mRNA stability required ongoing protein synthesis. Therefore, both promoter-dependent and -independent pathways converge to enhance IGFBP-5 gene expression in response to PGE2 in osteoblasts.

  14. Lipo-PGE1, a new lipid-encapsulated preparation of prostaglandin E1: placebo-and prostaglandin E1-controlled multicenter trials in patients with diabetic neuropathy and leg ulcers.

    PubMed

    Toyota, T; Hirata, Y; Ikeda, Y; Matsuoka, K; Sakuma, A; Mizushima, Y

    1993-11-01

    Several clinical trials have shown that prostaglandin E1 (PGE1) is effective in treating peripheral occlusive vascular disease, but not definitely for diabetic neuropathy. We developed a new preparation of PGE1 incorporated in lipid microspheres (lipo-PGE1) that was designed to accumulate at vascular lesions. The effect of lipo-PGE1 (10 micrograms/day) was compared with placebo and the normal dose of a free PGE1 preparation (PGE1-CD, 40 micrograms/day) in two studies (double-blind and well-controlled) which enrolled 364 diabetic patients with neuropathy and/or leg ulcers. The drugs were given intravenously (bolus or drip infusion) for 4 weeks. Clinical improvement was noted in 61.6% of the lipo-PGE1 group and 30.0% of the placebo group in Trial 1 (p < 0.01), while the figures were 58.3% in the lipo-PGE1 group and 37.1% in the PGE1-CD group in Trial 2 (p < 0.01). Leg ulcers became smaller in the lipo-PGE1 groups in both trials (p < 0.01). In Trial 2, motor conduction velocity improved in the lipo-PGE1 group (p = 0.016). Side effects occurred in few patients receiving lipo-PGE1 or placebo, but more patients developed local side effects in the PGE1-CD group (p < 0.01). Thus, bolus intravenous injection of lipo-PGE1 improved diabetic neuropathy and leg ulcers with minimal side effects.

  15. Abnormal TNF-alpha production in diabetes-prone BB rats: enhanced TNF-alpha expression and defective PGE2 feedback inhibition.

    PubMed Central

    Rothe, H; Ongören, C; Martin, S; Rösen, P; Kolb, H

    1994-01-01

    Upon stimulation with lipopolysaccharide (LPS), peritoneal macrophages from diabetes-prone Bio-Breeding (BB) rats secrete more tumour necrosis factor-alpha (TNF-alpha) than macrophages from diabetes-resistant BB or normal Wistar rats. Enhanced transcription was demonstrated by Northern blot analysis and at the single cell level by mRNA: RNA hybridization. Cytofluorometry analysis showed 2-4 times more plasma membrane and total cell-associated TNF-alpha in macrophages of diabetes-prone BB rats. The analysis of fluorescence intensity showed a single peak, and TNF-alpha mRNA was found in > 90% of macrophages. These findings exclude TNF hypersecretion as being due to an abnormal subfraction of cells. TNF-alpha gene hyperexpression in diabetes-prone BB rats was not due to mutations in the regulatory regions of the promoter, which could be shown by cloning and sequencing of the TNF-alpha promoter in the three rat strains. When searching for other regulatory defects we found the production of prostaglandin E2 (PGE2) in response to LPS to be up to 10 times lower in macrophages from diabetes-prone BB rats than from Wistar rats. Furthermore, BB rats macrophages required significantly higher concentrations of PGE2 for suppression of TNF-alpha secretion. We conclude that abnormal TNF-alpha production in macrophages from diabetes-prone BB rats is due to enhanced gene transcription and translation and that this is associated with defective PGE2 feedback inhibition. Images Figure 1 Figure 2 PMID:8206514

  16. Further evidence implicating prostaglandin E sub 2 in the genesis of pyrogen fever

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coceani, F.; Lees, J.; Bishai, I.

    1988-03-01

    Conscious cats were used to study the effects of endotoxin and interleukin 1 (IL 1) on levels of prostaglandin (PG) E{sub 2} and thromboxane (TX) B{sub 2} (the stable TXA{sub 2} byproduct) in cerebrospinal fluid (CSF) from the third ventricle. Pyrogens were given intravenously or intraventricularly and prostanoids were measured by radioimmunoassay. PGE{sub 2} was normally less abundant than TXB{sub 2}, and its level increased severalfold during the sustained fever following intravenous endotoxin (bolus) or IL 1 (bolus plus infusion). PGE{sub 2} elevation preceded the fever and was maintained thereafter. Likewise, intraventricular pyrogens promoted PGE{sub 2} formation, and their effectmore » was also manifest during the latent period of the fever. The PGE{sub 2} metabolite, 13,14-dihydro-15-keto-PGE{sub 2}, was not measurable in CSF from either afebrile or febrile animals. Basal content of PGE{sub 2}, on the other hand, was higher in animals pretreated with probenecid, confirming the importance of transport processes in removing prostanoids from brain. Unlike PGE{sub 2}, TXB{sub 2} levels did not change during the fever to intravenous endotoxin. TXB{sub 2} rose instead in response to intraventricular endotoxin, although the elevation did not extend beyond fever uprise. Furthermore, a TXA{sub 2} analog had inconsistent effects on body temperature, while a TXA{sub 2} antagonist did not interfere with endotoxin fever. These findings strongly support a causative role for PGE{sub 2} in the onset and progression of pyrogen fever. No evidence of a similar role was obtained for TXA{sub 2}.« less

  17. Cellular density-dependent down-regulation of EP4 prostanoid receptors via the up-regulation of hypoxia-inducible factor-1α in HCA-7 human colon cancer cells.

    PubMed

    Otake, Sho; Yoshida, Kenji; Seira, Naofumi; Sanchez, Christopher M; Regan, John W; Fujino, Hiromichi; Murayama, Toshihiko

    2015-02-01

    Increases in prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) levels are features of colon cancer. Among the different E-type prostanoid receptor subtypes, EP4 receptors are considered to play a crucial role in carcinogenesis by, for example, inducing COX-2 when stimulated with PGE2. However, EP4 receptor levels and PGE2-induced cellular responses are inconsistent among the cellular conditions. Therefore, the connections responsible for the expression of EP4 receptors were investigated in the present study by focusing on cell density-induced hypoxia-inducible factor-1α (HIF-1α). The expression of EP4 receptors was examined using immunoblot analysis, quantitative polymerase chain reaction, and reporter gene assays in HCA-7 human colon cancer cells with different cellular densities. The involvement of HIF-1α and its signaling pathways were also examined by immunoblot analysis, reporter gene assays, and with siRNA. We here demonstrated that EP4 receptors as well as EP4 receptor-mediated COX-2 expression levels decreased with an increase in cellular density. In contrast, HIF-1α levels increased in a cellular density-dependent manner. The knockdown of HIF-1α by siRNA restored the expression of EP4 receptors and EP4 receptor-mediated COX-2 in cells at a high density. Thus, the cellular density-dependent increase observed in HIF-1α expression levels reduced the expression of COX-2 by decreasing EP4 receptor levels. This novel regulation mechanism for the expression of EP4 receptors by HIF-1α may provide an explanation for the inconsistent actions of PGE2. The expression levels of EP4 receptors may vary depending on cellular density, which may lead to the differential activation of their signaling pathways by PGE2. Thus, cellular density-dependent PGE2-mediated signaling may determine the fate/stage of cancer cells, i.e., the surrounding environments could define the fate/stage of malignancies associated with colon cancer.

  18. Cellular density-dependent down-regulation of EP4 prostanoid receptors via the up-regulation of hypoxia-inducible factor-1α in HCA-7 human colon cancer cells

    PubMed Central

    Otake, Sho; Yoshida, Kenji; Seira, Naofumi; Sanchez, Christopher M; Regan, John W; Fujino, Hiromichi; Murayama, Toshihiko

    2015-01-01

    Increases in prostaglandin E2 (PGE2) and cyclooxygenase-2 (COX-2) levels are features of colon cancer. Among the different E-type prostanoid receptor subtypes, EP4 receptors are considered to play a crucial role in carcinogenesis by, for example, inducing COX-2 when stimulated with PGE2. However, EP4 receptor levels and PGE2-induced cellular responses are inconsistent among the cellular conditions. Therefore, the connections responsible for the expression of EP4 receptors were investigated in the present study by focusing on cell density-induced hypoxia-inducible factor-1α (HIF-1α). The expression of EP4 receptors was examined using immunoblot analysis, quantitative polymerase chain reaction, and reporter gene assays in HCA-7 human colon cancer cells with different cellular densities. The involvement of HIF-1α and its signaling pathways were also examined by immunoblot analysis, reporter gene assays, and with siRNA. We here demonstrated that EP4 receptors as well as EP4 receptor-mediated COX-2 expression levels decreased with an increase in cellular density. In contrast, HIF-1α levels increased in a cellular density-dependent manner. The knockdown of HIF-1α by siRNA restored the expression of EP4 receptors and EP4 receptor-mediated COX-2 in cells at a high density. Thus, the cellular density-dependent increase observed in HIF-1α expression levels reduced the expression of COX-2 by decreasing EP4 receptor levels. This novel regulation mechanism for the expression of EP4 receptors by HIF-1α may provide an explanation for the inconsistent actions of PGE2. The expression levels of EP4 receptors may vary depending on cellular density, which may lead to the differential activation of their signaling pathways by PGE2. Thus, cellular density-dependent PGE2-mediated signaling may determine the fate/stage of cancer cells, i.e., the surrounding environments could define the fate/stage of malignancies associated with colon cancer. PMID:25692008

  19. The role of prostaglandins E1 and E2, dinoprostone, and misoprostol in cervical ripening and the induction of labor: a mechanistic approach.

    PubMed

    Bakker, Ronan; Pierce, Stephanie; Myers, Dean

    2017-08-01

    Prostaglandins play a critical role in cervical ripening by increasing inflammatory mediators in the cervix and inducing cervical remodeling. Prostaglandin E1 (PGE1) and prostaglandin E2 (PGE2) exert different effects on these processes and on myometrial contractility. These mechanistic differences may affect outcomes in women treated with dinoprostone, a formulation identical to endogenous PGE2, compared with misoprostol, a PGE1 analog. The objective of this review is to evaluate existing evidence regarding mechanistic differences between PGE1 and PGE2, and consider the clinical implications of these differences in patients requiring cervical ripening for labor induction. We conducted a critical narrative review of peer-reviewed articles identified using PubMed and other online databases. While both dinoprostone and misoprostol are effective in cervical ripening and labor induction, they differ in their clinical and pharmacological profiles. PGE2 has been shown to stimulate interleukin-8, an inflammatory cytokine that promotes the influx of neutrophils and induces remodeling of the cervical extracellular matrix, and to induce functional progesterone withdrawal. Misoprostol has been shown to elicit a dose-dependent effect on myometrial contractility, which may affect rates of uterine tachysystole in clinical practice. Differences in the mechanism of action between misoprostol and PGE2 may contribute to their variable effects in the cervix and myometrium, and should be considered to optimize outcomes.

  20. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes

    PubMed Central

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Background: Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. Objective: In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Materials and Methods: Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11–7082. Results: Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11–7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Conclusions: Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. SUMMARY Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits

  1. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes.

    PubMed

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11-7082. Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11-7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits production of cartilage degrading PGE2 via inhibition of COX-2 expression

  2. Dihydroartemisinin inhibits indoxyl sulfate (IS)-promoted cell cycle progression in mesangial cells by targeting COX-2/mPGES-1/PGE2 cascade.

    PubMed

    Mungun, Harr-Keshauve; Li, Shuzhen; Zhang, Yue; Huang, Songming; Jia, Zhanjun; Ding, Guixia; Zhang, Aihua

    2018-01-01

    Dihydroartemisinin (DHA) is a semisynthetic derivative of artemisinin and has been used as an antimalarial drug. Recently, roles of artemisinin and its derivatives in treating diseases besides antimalarial effect were documented. Thus, this study was undertaken to investigate the role of DHA in indoxyl sulfate (IS)-promoted cell cycle progression in glomerular mesangial cells, as well as the potential mechanisms. Under the basal condition, DHA significantly retarded the cell cycle progression as shown by decreased cell percentage in S phase and increased cell percentage in G1/G0 phases in line with reduced cell cycle proteins cyclin A2 and cyclin D1. Interestingly, DHA also inactivated the COX-2/mPGES-1/PGE 2 cascade which has been shown to play a critical role in promoting the mesangial cell cycle progression by our previous studies. Next, we investigated the role of DHA in IS-triggered cell cycle progression in this mesangial cell line. As expected, DHA treatment significantly retarded IS-induced cell cycle progression and inhibited the activation of COX-2/mPGES-1/PGE 2 cascade induced by IS. In summary, these data indicated that DHA inhibited the cell cycle progression in glomerular mesangial cells under normal condition or IS challenge possibly through the inhibition of COX-2/mPGES-1/PGE 2 cascade, suggesting a potential of DHA in treating glomerular diseases with mesangial cell proliferation.

  3. In vitro pharmacological characterization of CJ-042794, a novel, potent, and selective prostaglandin EP(4) receptor antagonist.

    PubMed

    Murase, Akio; Taniguchi, Yasuhito; Tonai-Kachi, Hiroko; Nakao, Kazunari; Takada, Junji

    2008-01-16

    Activation of the prostaglandin E(2) (PGE(2)) EP(4) receptor, a G-protein-coupled receptor (GPCR), results in increases in intracellular cyclic AMP (cAMP) levels via stimulation of adenylate cyclase. Here we describe the in vitro pharmacological characterization of a novel EP(4) receptor antagonist, CJ-042794 (4-{(1S)-1-[({5-chloro-2-[(4-fluorophenyl)oxy]phenyl}carbonyl)amino]ethyl}benzoic acid). CJ-042794 inhibited [(3)H]-PGE(2) binding to the human EP(4) receptor with a mean pK(i) of 8.5, a binding affinity that was at least 200-fold more selective for the human EP(4) receptor than other human EP receptor subtypes (EP(1), EP(2), and EP(3)). CJ-042794 did not exhibit any remarkable binding to 65 additional proteins, including GPCRs, enzymes, and ion channels, suggesting that CJ-042794 is highly selective for the EP(4) receptor. CJ-042794 competitively inhibited PGE(2)-evoked elevations of intracellular cAMP levels in HEK293 cells overexpressing human EP(4) receptor with a mean pA(2) value of 8.6. PGE(2) inhibited the lipopolysaccharide (LPS)-induced production of tumor necrosis factor alpha (TNFalpha) in human whole blood (HWB); CJ-042794 reversed the inhibitory effects of PGE(2) on LPS-induced TNFalpha production in a concentration-dependent manner. These results suggest that CJ-042794, a novel, potent, and selective EP(4) receptor antagonist, has excellent pharmacological properties that make it a useful tool for exploring the physiological role of EP(4) receptors.

  4. mPGES-1-derived prostaglandin E2 stimulates Stat3 to promote podocyte apoptosis.

    PubMed

    Yu, Jing; Wu, Yimei; Wang, Lu; Zhang, Wen; Xu, Man; Song, Jiayu; Fu, Yu; Cui, Yiyun; Gong, Wei; Li, Shuzhen; Xia, Weiwei; Huang, Songming; Zhang, Aihua; Jia, Zhanjun

    2017-11-01

    We previously reported that microsomal prostaglandin E synthase-1 (mPGES-1) contributed to adriamycin (Adr)-induced podocyte apoptosis. However, the molecular mechanism remains unclear. Here we studied the role of mPGES-1/PGE2 cascade in activating Stat3 signaling and the contribution of Stat3 in PGE2- and Adr-induced podocyte apoptosis. In murine podocytes, PGE2 dose- and time-dependently increased the phosphorylation of Stat3 in line with the enhanced cell apoptosis and reduced podocyte protein podocin. In agreement with the increased Stat3 phosphorylation, Stat3-derived cytokines including IL-6, IL-17, MCP-1, and ICAM-1 were significantly upregulated following PGE2 treatment. By application of a specific Stat3 inhibitor S3I-201, PGE2-induced podocyte apoptosis was largely abolished in parallel with a blockade of podocin reduction. Next, we observed that Adr treatment also enhanced p-Stat3 and activated mPGES-1/PGE2 cascade. Blockade of Stat3 by S3I-201 significantly ameliorated Adr-induced cell apoptosis and podocin reduction. More interestingly, silencing mPGES-1 in podocytes by mPGES-1 siRNA blocked Adr-induced increments of Stat-3 phosphorylation, PGE2 production, and Stat3-derived inflammatory cytokines. Taken together, this study suggested that mPGES-1-derived PGE2 could activate Stat3 signaling to promote podocyte apoptosis. Targeting mPGES-1/PGE2/Stat3 signaling might be a potential strategy for the treatment of podocytopathy.

  5. Sources of anthropogenic platinum-group elements (PGE): Automotive catalysts versus PGE-processing industries.

    PubMed

    Zereini, F; Dirksen, F; Skerstupp, B; Urban, H

    1998-01-01

    Soil samples from the area of Hanau (Hessen, Germany) were analyzed for anthropogenic platinum-group elements (PGE). The results confirm the existence of two different sources for anthropogenic PGE: 1. automotive catalysts, and 2. PGE-processing plants. Both sources emit qualitatively and quantitatively different PGE spectra and PGE interelemental ratios (especially the Pt/Rh ratio). Elevated PGE values which are due to automotive catalysts are restricted to a narrow-range along roadside soil, whereas those due to PGE-processing plants display a large-area dispersion. The emitted PGE-containing particles in the case of automotive catalysts are subject to transport by wind and water, whereas those from PGE-processing plants are preferably transported by wind. This points to a different aerodynamic particle size. Pt, Pd, and Rh concentrations along motorways are dependent on the amount of traffic and the driving characteristics.

  6. Antioxidant Biomarkers from Vanda coerulea Stems Reduce Irradiated HaCaT PGE-2 Production as a Result of COX-2 Inhibition

    PubMed Central

    Simmler, Charlotte; Antheaume, Cyril; Lobstein, Annelise

    2010-01-01

    Background In our investigations towards the isolation of potentially biologically active constituents from Orchidaceae, we carried out phytochemical and biological analyses of Vanda species. A preliminary biological screening revealed that Vanda coerulea (Griff. ex. Lindl) crude hydro-alcoholic stem extract displayed the best DPPH /•OH radical scavenging activity and in vitro inhibition of type 2 prostaglandin (PGE-2) release from UVB (60 mJ/cm2) irradiated HaCaT keratinocytes. Principal Findings Bio-guided fractionation and phytochemical analysis led to the isolation of five stilbenoids: imbricatin (1) methoxycoelonin (2) gigantol (3) flavidin (4) and coelonin (5). Stilbenoids (1–3) were the most concentrated in crude hydro-alcoholic stem extract and were considered as Vanda coerulea stem biomarkers. Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/•OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC50 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC50 20.6 µM). In turn, the latter showed a constant inhibition of PGE-2 production, stronger than stilbenoids (1) and (2) (IC50 12.2 µM and 19.3 µM, respectively). Western blot analysis revealed that stilbenoids (1–3) inhibited COX-2 expression at 23 µM. Interestingly, stilbenoids (1) and (2) but not (3) were able to inhibit human recombinant COX-2 activity. Conclusions Major antioxidant stilbenoids (1–3) from Vanda coerulea stems displayed an inhibition of UVB-induced COX-2 expression. Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells. Our studies suggest that stilbenoids (1–3) could be potentially used for skin protection against the damage caused by UVB exposure. PMID:21060890

  7. Areca nut components stimulate ADAM17, IL-1α, PGE2 and 8-isoprostane production in oral keratinocyte: role of reactive oxygen species, EGF and JAK signaling.

    PubMed

    Chang, Mei-Chi; Chan, Chiu-Po; Chen, Yi-Jane; Hsien, Hsiang-Chi; Chang, Ya-Ching; Yeung, Sin-Yuet; Jeng, Po-Yuan; Cheng, Ru-Hsiu; Hahn, Liang-Jiunn; Jeng, Jiiang-Huei

    2016-03-29

    Betel quid (BQ) chewing is an etiologic factor of oral submucous fibrosis (OSF) and oral cancer. There are 600 million BQ chewers worldwide. The mechanisms for the toxic and inflammatory responses of BQ are unclear. In this study, both areca nut (AN) extract (ANE) and arecoline stimulated epidermal growth factor (EGF) and interleukin-1α (IL-1α) production of gingival keratinocytes (GKs), whereas only ANE can stimulate a disintegrin and metalloproteinase 17 (ADAM17), prostaglandin E2 (PGE2) and 8-isoprostane production. ANE-induced EGF production was inhibited by catalase. Addition of anti-EGF neutralizing antibody attenuated ANE-induced cyclooxygenase-2 (COX-2), mature ADAM9 expression and PGE2 and 8-isoprostane production. ANE-induced IL-1α production was inhibited by catalase, anti-EGF antibody, PD153035 (EGF receptor antagonist) and U0126 (MEK inhibitor) but not by α-naphthoflavone (cytochrome p450-1A1 inhibitor). ANE-induced ADAM17 production was inhibited by pp2 (Src inhibitor), U0126, α-naphthoflavone and aspirin. AG490 (JAK inhibitor) prevented ANE-stimulated ADAM17, IL-1α, PGE2 production, COX-2 expression, ADAM9 maturation, and the ANE-induced decline in keratin 5 and 14, but showed little effect on cdc2 expression and EGF production. Moreover, ANE-induced 8-isoprostane production by GKs was inhibited by catalase, anti-EGF antibody, AG490, pp2, U0126, α-naphthoflavone, Zinc protoporphyrin (ZnPP) and aspirin. These results indicate that AN components may involve in BQ-induced oral cancer by induction of reactive oxygen species, EGF/EGFR, IL-1α, ADAMs, JAK, Src, MEK/ERK, CYP1A1, and COX signaling pathways, and the aberration of cell cycle and differentiation. Various blockers against ROS, EGF, IL-1α, ADAM, JAK, Src, MEK, CYP1A1, and COX can be used for prevention or treatment of BQ chewing-related diseases.

  8. Cyclooxygenase-2-issued prostaglandin e(2) enhances the production of endogenous IL-10, which down-regulates dendritic cell functions.

    PubMed

    Harizi, Hedi; Juzan, Monique; Pitard, Vincent; Moreau, Jean-François; Gualde, Norbert

    2002-03-01

    PGE(2) is a well-known immunomodulator produced in the immune response by APCs, such as dendritic cells (DCs), the most potent APC of the immune system. We investigated the PGE(2) biosynthetic capacity of bone marrow-derived DC (BM-DC) and the effects of PG on the APC. We observed that BM-DC produce PGE(2) and other proinflammatory mediators, such as leukotriene B(4) and NO, after LPS exposure. Constitutively present in BM-DC, cyclooxygenase (COX)-1 did not contribute significantly to the total pool of PGE(2) compared with the LPS-induced COX-2-produced PGE(2). Treatment of BM-DC with exogenous PGE(2) induced the production of large amounts of IL-10 and less IL-12p70. In addition, selective inhibition of COX-2, but not COX-1, was followed by significant decrements in PGE(2) and IL-10, a concomitant restoration of IL-12 production, and an enhancement of DC stimulatory potential. In contrast, we found no demonstrable role for leukotriene B(4) or NO. In view of the potential of PGE(2) to stimulate IL-10, we examined the possibility that the suppressive effect of PGE(2) is mediated via IL-10. We found that exogenous IL-10 inhibits IL-12p70 production in the presence of NS-398, a COX-2 selective inhibitor, while the inhibitory effects of PGE(2) were totally reversed by anti-IL-10. We conclude that COX-2-mediated PGE(2) up-regulates IL-10, which down-regulates IL-12 production and the APC function of BM-DC.

  9. Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47{sup phox} pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsai, Ming-Horng; Lin, Zih-Chan; Liang, Chan-Jung

    2014-09-01

    Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phoxmore » activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47{sup phox}/JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47{sup phox} inhibition. • Eupafolin may be used in the treatment of skin diseases involving

  10. PTGS-2–PTGER2/4 Signaling Pathway Partially Protects From Diabetogenic Toxicity of Streptozotocin in Mice

    PubMed Central

    Vennemann, Antje; Gerstner, Anemone; Kern, Niklas; Ferreiros Bouzas, Nerea; Narumiya, Shuh; Maruyama, Takayuki; Nüsing, Rolf M.

    2012-01-01

    Prostanoids are suggested to participate in diabetes pathology, but their roles are controversially discussed. The purpose of the current study was to examine the role of cyclooxygenase (prostaglandin synthase [PTGS]) enzymes and prostaglandin (PG) E2 signaling pathways in streptozotocin (STZ)-induced type 1 diabetes. Blood glucose, insulin, and survival rate were studied in mice with targeted disruption of the genes for PTGS and PGE receptors (PTGERs). PGE2 was found as the main prostanoid formed by the pancreas. Contrarily to PTGS-1, deficiency of PTGS-2 activity significantly amplified STZ effect, causing dramatic loss of insulin production and rise in blood glucose and death rate. STZ metabolism was unaffected by PTGS deficiency. Diabetogenicity of STZ in PTGER1−/−, PTGER2−/−, PTGER3−/−, and PTGER4−/− mice was comparable to control mice. In striking contrast, combined knockout of PTGER2 and PTGER4 by blocking PTGER4 in PTGER2−/− mice strongly enhanced STZ pathology. Treatment of PTGS-2−/− and wild-type mice with PTGER2/PTGER4 agonists partially protected against STZ-induced diabetes and restored β-cell function. Our data uncover a previously unrecognized protective role of PTGS-2–derived PGE2 in STZ-induced diabetes mediated by the receptor types PTGER2 and PTGER4. These findings offer the possibility to intervene in early progression of type 1 diabetes by using PTGER-selective agonists. PMID:22522619

  11. Lactobacillus fermentum ZYL0401 Attenuates Lipopolysaccharide-Induced Hepatic TNF-α Expression and Liver Injury via an IL-10- and PGE2-EP4-Dependent Mechanism

    PubMed Central

    Lv, Longxian; Yang, Jianzhuan; Lu, Haifeng; Li, Lanjuan

    2015-01-01

    Lipopolysaccharide (LPS) has essential role in the pathogenesis of D-galactosamine-sensitized animal models and alcoholic liver diseases of humans, by stimulating release of pro-inflammatory mediators that cause hepatic damage and intestinal barrier impairment. Oral pretreatment of probiotics has been shown to attenuate LPS-induced hepatic injury, but it is unclear whether the effect is direct or due to improvement in the intestinal barrier. The present study tested the hypothesis that pretreatment with probiotics enables the liver to withstand directly LPS-induced hepatic injury and inflammation. In a mouse model of LPS-induced hepatic injury, the levels of hepatic tumor necrosis factor-alpha (TNF-α) and serum alanine aminotransferase (ALT) of mice with depleted intestinal commensal bacteria were not significantly different from that of the control models. Pre-feeding mice for 10 days with Lactobacillus fermentum ZYL0401 (LF41), significantly alleviated LPS-induced hepatic TNF-α expression and liver damage. After LF41 pretreatment, mice had dramatically more L.fermentum-specific DNA in the ileum, significantly higher levels of ileal cyclooxygenase (COX)-2 and interleukin 10 (IL-10) and hepatic prostaglandin E2 (PGE2). However, hepatic COX-1, COX-2, and IL-10 protein levels were not changed after the pretreatment. There were also higher hepatic IL-10 protein levels after LPS challenge in LF41-pretreaed mice than in the control mice. Attenuation of hepatic TNF-α was mediated via the PGE2/E prostanoid 4 (EP4) pathway, and serum ALT levels were attenuated in an IL-10-dependent manner. A COX-2 blockade abolished the increase in hepatic PGE2 and IL-10 associated with LF41. In LF41-pretreated mice, a blockade of IL-10 caused COX-2-dependent promotion of hepatic PGE2, without affecting hepatic COX-2levels. In LF41-pretreated mice, COX2 prevented enhancing TNF-α expression in both hepatic mononuclear cells and the ileum, and averted TNF-α-mediated increase in

  12. Prostaglandin E2 increases hematopoietic stem cell survival and accelerates hematopoietic recovery after radiation injury

    PubMed Central

    Porter, Rebecca L.; Georger, Mary; Bromberg, Olga; McGrath, Kathleen E.; Frisch, Benjamin J.; Becker, Michael W.; Calvi, Laura M.

    2013-01-01

    Hematopoietic stem and progenitor cells (HSPCs), which continuously maintain all mature blood cells, are regulated within the marrow microenvironment. We previously reported that pharmacologic treatment of naïve mice with prostaglandin E2 (PGE2) expands HSPCs. However, the cellular mechanisms mediating this expansion remain unknown. Here we demonstrate that PGE2 treatment in naïve mice inhibits apoptosis of HSPCs without changing their proliferation rate. In a murine model of sub-lethal total body irradiation (TBI), in which HSPCs are rapidly lost, treatment with a long-acting PGE2 analogue (dmPGE2) reversed the apoptotic program initiated by TBI. dmPGE2 treatment in vivo decreased the loss of functional HSPCs following radiation injury, as demonstrated both phenotypically and by their increased reconstitution capacity. The antiapoptotic effect of dmPGE2 on HSPCs did not impair their ability to differentiate in vivo, resulting instead in improved hematopoietic recovery after TBI. dmPGE2 also increased microenvironmental cyclooxygenase-2 expression and expanded the α-SMA+ subset of marrow macrophages, thus enhancing the bone marrow microenvironmental response to TBI. Therefore, in vivo treatment with PGE2 analogues may be particularly beneficial to HSPCs in the setting of injury by targeting them both directly and also through their niche. The current data provide rationale for in vivo manipulation of the HSPC pool as a strategy to improve recovery after myelosuppression. PMID:23169593

  13. Differential effect of ethanol and hydrogen peroxide on barrier function and prostaglandin E2 release in differentiated Caco-2 cells: selective prevention by growth factors.

    PubMed

    Catalioto, Rose-Marie; Festa, Carla; Triolo, Antonio; Altamura, Maria; Maggi, Carlo Alberto; Giuliani, Sandro

    2009-02-01

    The present study investigates the effects of ethanol and hydrogen peroxide (H(2)O(2)) on the barrier function and prostaglandin E(2) (PGE(2)) release in differentiated Caco-2 cells. Epithelial barrier integrity was estimated by measuring transepithelial electrical resistance (TEER), the transport of reference compounds and lactate dehydrogenase leakage, the PGE(2) release by enzyme immunoassay. Ethanol and H(2)O(2) decreased TEER and increased the transport of lucifer yellow without affecting that of propranolol and phenylalanine. Only the effects of ethanol were accompanied by PGE(2) production and were reversible without causing long-term cytotoxicity. The cyclooxygenase-2 inhibitor, NS-398, prevented the effect of ethanol on both PGE(2) release and TEER, while inhibition of both cyclooxygenase-2 and tyrosine kinase drastically compromised cell viability and TEER recovery. Hepatocyte growth factor, keratinocyte growth factor or insulin prevented the effect of ethanol on cell permeability, but not on PGE(2) release. Their combination prevented the effect of H(2)O(2). In conclusion, ethanol and H(2)O(2) increased paracellular permeability in differentiated Caco-2 cells without affecting transcellular and active transport. Cyclooxygenase-2 stimulated PGE(2) release mediated the reversible effect of ethanol on tight junctions and, meanwhile, contributed to cell survival. Growth factors, normally present in the intestine, exerted a selective protective effect toward paracellular permeability increase induced by irritants.

  14. Effects of balneotherapy on serum IL-1, PGE2 and LTB4 levels in fibromyalgia patients.

    PubMed

    Ardiç, Füsum; Ozgen, Merih; Aybek, Hülya; Rota, Simin; Cubukçu, Duygu; Gökgöz, Ali

    2007-03-01

    The purpose of this study was to investigate the clinical effects of balneotherapy in the treatment of Fibromyalgia Syndrome (FMS) and to determine if balneotherapy influences serum levels of inflammation markers, IL-1, PGE2 and LTB4. 24 primary fibromyalgia female patients diagnosed according to American College of Rheumatology criteria were included to the study. Their ages ranged between 33 and 55 years. FMS patients were randomly assigned in two groups as, group 1 (n = 12) and group 2 (n = 12). Group 1 received 20-min bathing, once in a day for five days per week. Patients participated in the study for 3 weeks (total of 15 sessions) in Denizli. Group 2 did not receive balneotherapy. FMS patients were evaluated by tenderness measurements (tender point count and algometry), Visual Analogue Scale, Beck's Depression Index, Fibromyalgia Impact Questionnaire. Ten healthy women recruited group three as the controls. Serum PGE2, LTB4 and IL1-alpha levels were measured in all three groups. The biochemical measurements and clinical assessments were performed before and at the end of general period of therapy. Statistically significant alterations in algometric score, Visual Analogue score, Beck's Depression Index and PGE2 levels (P < 0.001), numbers of tender points (P < 0.01) and Fibromyalgia Impact Questionnaire score (P < 0.05) were found after the balneotherapy between group 1 and 2. Mean PGE2 level of FMS patients were higher compared to healthy control group (P < 0.0001) and decreased after the treatment period, only in group 1 (P < 0.05). As in the group 2 and 3, detectable IL-1 and LTB4 measurements were insufficient, statistical analysis was performed, only in group 1. After balneotherapy IL-1 and LTB4 significantly decreased in group 1 (P < 0.05). In conclusion, balneotherapy is an effective choice of treatment in patients with FMS relieving the clinical symptoms, and possibly influencing the inflammatory mediators.

  15. Argon laser irradiation of rabbits' eyes-changes in prostaglandin E2 levels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Naveh, N.; Peer, J.; Bartov, E.

    1991-02-01

    Laser irradiation of the eye is a widely used therapeutic measure in various ocular disorders. We investigated in laser-treated rabbits' eyes the changes in prostaglandin E2 (PGE2) levels of the tissue affected by the laser (the retina/choroid) and of its adjacent vitreous over a two-week period. The parameters studied were; PGE2 in vitro production by the retina/choroid, as well as PGE2 and protein levels in the vitreous, the latter indicative of a break in the blood retinal barrier (BRB). The effect of noncoherent light exposure used for illumination, and that of the mechanical manipulation involved (sham exposure) were also studied.more » Following laser exposure vitreal PGE2 levels were increased two-fold above baseline (days three and 14), whereas light exposure resulted in a single peak. PGE2 in vitro production by the retina/choroid in the laser-exposed group was elevated throughout the observation period, peaking twice (days 3 and 14), in the light-exposed group the enhanced production was evident during a shorter period, whereas in the sham group it remained unchanged from baseline. An elevation in vitreal protein levels to above baseline levels occurred in both the laser- and, to a lesser degree, in the noncoherent light-exposed groups, but not in the sham group. Our study demonstrated an enhanced PGE2 in vitro production by retina/choroid of laser-exposed eyes, which might be attributable to the additive effect of the laser induced trauma, and the noncoherent light photochemical changes; the clinical significance of the recurrent increase in vitreal PGE2 levels in laser-treated eyes might be related to its anti-inflammatory properties.« less

  16. Peripheral Sensitization Increases Opioid Receptor Expression and Activation by Crotalphine in Rats

    PubMed Central

    Zambelli, Vanessa Olzon; Fernandes, Ana Carolina de Oliveira; Gutierrez, Vanessa Pacciari; Ferreira, Julio Cesar Batista; Parada, Carlos Amilcar; Mochly-Rosen, Daria; Cury, Yara

    2014-01-01

    Inflammation enhances the peripheral analgesic efficacy of opioid drugs, but the mechanisms involved in this phenomenon have not been fully elucidated. Crotalphine (CRP), a peptide that was first isolated from South American rattlesnake C.d. terrificus venom, induces a potent and long-lasting anti-nociceptive effect that is mediated by the activation of peripheral opioid receptors. Because the high efficacy of CRP is only observed in the presence of inflammation, we aimed to elucidate the mechanisms involved in the CRP anti-nociceptive effect induced by inflammation. Using real-time RT-PCR, western blot analysis and ELISA assays, we demonstrate that the intraplantar injection of prostaglandin E2 (PGE2) increases the mRNA and protein levels of the µ- and κ-opioid receptors in the dorsal root ganglia (DRG) and paw tissue of rats within 3 h of the injection. Using conformation state-sensitive antibodies that recognize activated opioid receptors, we show that PGE2, alone does not increase the activation of these opioid receptors but that in the presence of PGE2, the activation of specific opioid receptors by CRP and selective µ- and κ-opioid receptor agonists (positive controls) increases. Furthermore, PGE2 down-regulated the expression and activation of the δ-opioid receptor. CRP increased the level of activated mitogen-activated protein kinases in cultured DRG neurons, and this increase was dependent on the activation of protein kinase Cζ. This CRP effect was much more prominent when the cells were pretreated with PGE2. These results indicate that the expression and activation of peripheral opioid receptors by opioid-like drugs can be up- or down-regulated in the presence of an acute injury and that acute tissue injury enhances the efficacy of peripheral opioids. PMID:24594607

  17. The zebrafish orphan nuclear receptor genes nr2e1 and nr2e3 are expressed in developing eye and forebrain.

    PubMed

    Kitambi, Satish Srinivas; Hauptmann, Giselbert

    2007-02-01

    Mammalian Nr2e1 (Tailless, Mtll or Tlx) and Nr2e3 (photoreceptor-specific nuclear receptor, Pnr) are highly related orphan nuclear receptors, that are expressed in eye and forebrain-derived structures. In this study, we analyzed the developmental expression patterns of zebrafish nr2e1 and nr2e3. RT-PCR analysis showed that nr2e1 and nr2e3 are both expressed during embryonic and post-embryonic development. To examine the spatial distribution of nr2e1 and nr2e3 during development whole-mount in situ hybridization was performed. At tailbud stage, initial nr2e1 expression was localized to the rostral brain rudiment anterior to pax2.1 and eng2 expression at the prospective midbrain-hindbrain boundary. During subsequent stages, nr2e1 became widely expressed in fore- and midbrain primordia, eye and olfactory placodes. At 24hpf, strong nr2e1 expression was detected in telencephalon, hypothalamus, dorsal thalamus, pretectum, midbrain tectum, and retina. At 2dpf, the initially widespread nr2e1 expression became more restricted to distinct regions within the fore- and midbrain and to the retinal ciliary margin, the germinal zone which gives rise to retina and presumptive iris. Expression of nr2e3 was exclusively found in the developing retina and epiphysis. In both structures, nr2e3 expression was found in photoreceptor cells. The developmental expression profile of zebrafish nr2e1 and nr2e3 is consistent with evolutionary conserved functions in eye and rostral brain structures.

  18. IL-10 administration reduces PGE-2 levels and promotes CR3-mediated clearance of Escherichia coli K1 by phagocytes in meningitis.

    PubMed

    Mittal, Rahul; Gonzalez-Gomez, Ignacio; Panigrahy, Ashok; Goth, Kerstin; Bonnet, Richard; Prasadarao, Nemani V

    2010-06-07

    Ineffectiveness of antibiotics in treating neonatal Escherichia coli K1 meningitis and the emergence of antibiotic-resistant strains evidently warrants new prevention strategies. We observed that administration of interleukin (IL)-10 during high-grade bacteremia clears antibiotic-sensitive and -resistant E. coli from blood of infected mice. Micro-CT studies of brains from infected animals displayed gross morphological changes similar to those observed in infected human neonates. In mice, IL-10, but not antibiotic or anti-TNF antibody treatment prevented brain damage caused by E. coli. IL-10 administration elevated CR3 expression in neutrophils and macrophages of infected mice, whereas infected and untreated mice displayed increased expression of FcgammaRI and TLR2. Neutrophils or macrophages pretreated with IL-10 ex vivo exhibited a significantly greater microbicidal activity against E. coli compared with cells isolated from wild-type or IL-10-/- mice. The protective effect of IL-10 was abrogated when CR3 was knocked-down in vivo by siRNA. The increased expression of CR3 in phagocytes was caused by inhibition of prostaglandin E-2 (PGE-2) levels, which were significantly increased in neutrophils and macrophages upon E. coli infection. These findings describe a novel modality of IL-10-mediated E. coli clearance by diverting the entry of bacteria via CR3 and preventing PGE-2 formation in neonatal meningitis.

  19. Pharmacological characterisation of CR6086, a potent prostaglandin E2 receptor 4 antagonist, as a new potential disease-modifying anti-rheumatic drug.

    PubMed

    Caselli, Gianfranco; Bonazzi, Albino; Lanza, Marco; Ferrari, Flora; Maggioni, Daniele; Ferioli, Cristian; Giambelli, Roberto; Comi, Eleonora; Zerbi, Silvia; Perrella, Marco; Letari, Ornella; Di Luccio, Elena; Colovic, Milena; Persiani, Stefano; Zanelli, Tiziano; Mennuni, Laura; Piepoli, Tiziana; Rovati, Lucio Claudio

    2018-03-01

    Prostaglandin E 2 (PGE 2 ) acts via its EP4 receptor as a cytokine amplifier (e.g., interleukin [IL]-6) and induces the differentiation and expansion of inflammatory T-helper (Th) lymphocytes. These mechanisms play a key role in the onset and progression of rheumatoid arthritis (RA). We present the pharmacological characterisation of CR6086, a novel EP4 receptor antagonist, and provide evidence for its potential as a disease-modifying anti-rheumatic drug (DMARD). CR6086 affinity and pharmacodynamics were studied in EP4-expressing HEK293 cells by radioligand binding and cyclic adenosine monophosphate (cAMP) production, respectively. In immune cells, IL-6 and vascular endothelial growth factor (VEGF) expression were analysed by RT-PCR, and IL-23 and IL-17 release were measured by enzyme-linked immunosorbent assay (ELISA). In collagen-induced arthritis (CIA) models, rats or mice were immunised with bovine collagen type II. Drugs were administered orally (etanercept and methotrexate intraperitoneally) starting at disease onset. Arthritis progression was evaluated by oedema, clinical score and histopathology. Anti-collagen II immunoglobulin G antibodies were measured by ELISA. CR6086 showed selectivity and high affinity for the human EP4 receptor (K i = 16.6 nM) and functioned as a pure antagonist (half-maximal inhibitory concentration, 22 nM) on PGE 2 -stimulated cAMP production. In models of human immune cells in culture, CR6086 reduced key cytokine players of RA (IL-6 and VEGF expression in macrophages, IL-23 release from dendritic cells, IL-17 release from Th17 cells). In the CIA model of RA in rats and mice, CR6086 significantly improved all features of arthritis: severity, histology, inflammation and pain. In rats, CR6086 was better than the selective cyclooxygenase-2 inhibitor rofecoxib and at least as effective as the Janus kinase inhibitor tofacitinib. In mice, CR6086 and the biologic DMARD etanercept were highly effective, whereas the non-steroidal anti

  20. P2Y receptors and atherosclerosis in apolipoprotein E-deficient mice

    PubMed Central

    Guns, Pieter-Jan DF; Hendrickx, Jan; Van Assche, Tim; Fransen, Paul; Bult, Hidde

    2010-01-01

    Background and purpose: P2Y nucleotide receptors are involved in the regulation of vascular tone, smooth muscle cell (SMC) proliferation and inflammatory responses. The present study investigated whether they are involved in atherosclerosis. Experimental approach: mRNA of P2Y receptors was quantified (RT-PCR) in atherosclerotic and plaque-free aorta segments of apolipoprotein E-deficient (apoE–/–) mice. Macrophage activation was assessed in J774 macrophages, and effects of non-selective purinoceptor antagonists on atherosclerosis were evaluated in cholesterol-fed apoE–/– mice. Key results: P2Y6 receptor mRNA was consistently elevated in segments with atherosclerosis, whereas P2Y2 receptor expression remained unchanged. Expression of P2Y1 or P2Y4 receptor mRNA was low or undetectable, and not influenced by atherosclerosis. P2Y6 mRNA expression was higher in cultured J774 macrophages than in cultured aortic SMCs. Furthermore, immunohistochemical staining of plaques demonstrated P2Y6-positive macrophages, but few SMCs, suggesting that macrophage recruitment accounted for the increase in P2Y6 receptor mRNA during atherosclerosis. In contrast to ATP, the P2Y6-selective agonist UDP increased mRNA expression and activity of inducible nitric oxide synthase and interleukin-6 in J774 macrophages; this effect was blocked by suramin (100–300 µM) or pyridoxal-phosphate-6-azophenyl-2′-4′-disulphonic acid (PPADS, 10–30 µM). Finally, 4-week treatment of cholesterol-fed apoE–/– mice with suramin or PPADS (50 and 25 mg·kg−1·day−1 respectively) reduced plaque size, without changing plaque composition (relative SMC and macrophage content) or cell replication. Conclusions and implications: These results suggest involvement of nucleotide receptors, particularly P2Y6 receptors, during atherosclerosis, and warrant further research with selective purinoceptor antagonists or P2Y6 receptor-deficient mice. PMID:20050854

  1. Prostaglandin E2 Prevents Ovariectomy-Induced Cancellous Bone Loss in Rats

    NASA Technical Reports Server (NTRS)

    Ke, Hua Zhu; Li, Mei; Jee, Webster S. S.

    1992-01-01

    The object of this study was to determine whether prostaglandin E2, (PGE2) can prevent ovariectomy induced cancellous bone loss. Thirty-five 3-month-old female Sprague-Dawley rats were divided into two groups. The rats in the first group were ovariectomized (OVX) while the others received sham operation (sham-OVX). The OVX group was further divided into three treatment groups. The daily doses for the three groups were 0,1 and 6 mg PGE2/kg for 90 days. Bone histomorphometric analyses were performed on double-fluorescent-labeled undecalcified proximal tibial metaphysis (PTM). We confirmed that OVX induces massive cancellous bone loss (-80%) and a higher bone turnover (+143%). The new findings from the present study demonstrate that bone loss due to ovarian hormone deficiency can be prevented by a low-dose (1 mg) daily administration of PGE2. Furthermore, a higher-dose (6 mg) daily administration of PGE2 not only prevents bone loss but also adds extra bone to the proximal tibial metaphyses. PGE, at the 1-mg dose level significantly increased trabecular bone area, trabecular width, trabecular node density, density of node to node, ratio of node to free end, and thus significantly decreased trabecular separation from OVX controls. At this dose level, these same parameters did not differ significantly from sham-OVX controls. However, at the 6-mg dose level PGE2, there were significant increases in trabecular bone area, trabecular width, trabecular node density, density of node to node, and ratio of node to free end, while there was significant decrease in trabecular separation from both OVX and sham-operated controls. The changes in indices of trabecular bone microanatomical structure indicated that PGE2 prevented bone loss as well as the disconnection of existing trabeculae. In summary, PGE2, administration to OVX rats decreased bone turnover and increased bone formation parameters resulting in a positive bone balance that prevented bone loss (in both lower and higher

  2. Prostaglandins in the kidney: developments since Y2K.

    PubMed

    Nasrallah, Rania; Clark, Jordan; Hébert, Richard L

    2007-10-01

    There are five major PGs (prostaglandins/prostanoids) produced from arachidonic acid via the COX (cyclo-oxygenase) pathway: PGE(2), PGI(2) (prostacyclin), PGD(2), PGF(2alpha) and TXA(2) (thromboxane A(2)). They exert many biological effects through specific G-protein-coupled membrane receptors, namely EP (PGE(2) receptor), IP (PGI(2) receptor), DP (PGD(2) receptor), FP (PGF(2alpha) receptor) and TP (TXA(2) receptor) respectively. PGs are implicated in physiological and pathological processes in all major organ systems, including cardiovascular function, gastrointestinal responses, reproductive processes, renal effects etc. This review highlights recent insights into the role of each prostanoid in regulating various aspects of renal function, including haemodynamics, renin secretion, growth responses, tubular transport processes and cell fate. A thorough review of the literature since Y2K (year 2000) is provided, with a general overview of PGs and their synthesis enzymes, and then specific considerations of each PG/prostanoid receptor system in the kidney.

  3. Low physiological levels of prostaglandins E2 and F2α improve human sperm functions.

    PubMed

    Rios, Mariana; Carreño, Daniela V; Oses, Carolina; Barrera, Nelson; Kerr, Bredford; Villalón, Manuel

    2016-03-01

    Prostaglandins (PGs) have been reported to be present in the seminal fluid and cervical mucus, affecting different stages of sperm maturation from spermatogenesis to the acrosome reaction. This study assessed the effects of low physiological PGE2 and PGF2α concentrations on human sperm motility and on the ability of the spermatozoa to bind to the zona pellucida (ZP). Human spermatozoa were isolated from seminal samples with normal concentration and motility parameters and incubated with 1μM PGE2, 1μM PGF2α or control solution to determine sperm motility and the ability to bind to human ZP. The effects of both PGs on intracellular calcium levels were determined. Incubation for 2 or 18h with PGE2 or PGF2α resulted in a significant (P<0.05) increase in the percentage of spermatozoa with progressive motility. In contrast with PGF2α, PGE2 alone induced an increase in sperm intracellular calcium levels; however, the percentage of sperm bound to the human ZP was doubled for both PGs. These results indicate that incubation of human spermatozoa with low physiological levels of PGE2 or PGF2α increases sperm functions and could improve conditions for assisted reproduction protocols.

  4. Long-term anabolic effects of prostaglandin-E2 on tibial diaphyseal bone in male rats

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Ke, Hua Zhu; Li, Xiao Jian

    1991-01-01

    The effects of long-term prostaglandin E2 (PGE2) on tibial diaphyseal bone were studied in 7-month-old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3 and 6 mg PGE2/kg/day for 60, 120 and 180 days. The tibial shaft was measured by single photon absorptiometry and dynamic histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial diaphyseal bone samples. Exogenous PGE2 administration produced the following transient changes in a dose-response manner between zero and 60 days: (1) increased bone width and mineral density; (2) increased total tissue and total bone areas; (3) decreased marrow area; (4) increased periosteal and corticoendosteal lamellar bone formation; (5) activated corticoendosteal lamellar and woven trabecular bone formation; and (6) activated intracortical bone remodeling. A new steady-state of increased tibial diaphyseal bone mass and elevated bone activities were observed from day 60 onward. The elevated bone mass level attained after 60 days of PGE2 treatment was maintained at 120 and 180 days. These observations indicate that the powerful anabolic effects of PGE2 will increase both periosteal and corticoendosteal bone mass and sustain the transient increase in bone mass with continuous daily administration of PGE2.

  5. The prostaglandin EP1 receptor potentiates kainate receptor activation via a protein kinase C pathway and exacerbates status epilepticus

    PubMed Central

    Rojas, Asheebo; Gueorguieva, Paoula; Lelutiu, Nadia; Quan, Yi; Shaw, Renee; Dingledine, Raymond

    2014-01-01

    Prostaglandin E2 (PGE2) regulates membrane excitability, synaptic transmission, plasticity, and neuronal survival. The consequences of PGE2 release following seizures has been the subject of much study. Here we demonstrate that the prostaglandin E2 receptor 1 (EP1, or Ptger1) modulates native kainate receptors, a family of ionotropic glutamate receptors widely expressed throughout the central nervous system. Global ablation of the EP1 gene in mice (EP1-KO) had no effect on seizure threshold after kainate injection but reduced the likelihood to enter status epilepticus. EP1-KO mice that did experience typical status epilepticus had reduced hippocampal neurodegeneration and a blunted inflammatory response. Further studies with native prostanoid and kainate receptors in cultured cortical neurons, as well as with recombinant prostanoid and kainate receptors expressed in Xenopus oocytes, demonstrated that EP1 receptor activation potentiates heteromeric but not homomeric kainate receptors via a second messenger cascade involving phospholipase C, calcium and protein kinase C. Three critical GluK5 C-terminal serines underlie the potentiation of the GluK2/GluK5 receptor by EP1 activation. Taken together, these results indicate that EP1 receptor activation during seizures, through a protein kinase C pathway, increases the probability of kainic acid induced status epilepticus, and independently promotes hippocampal neurodegeneration and a broad inflammatory response. PMID:24952362

  6. Prostaglandin E2 is critical for the development of niacin-deficiency-induced photosensitivity via ROS production

    NASA Astrophysics Data System (ADS)

    Sugita, Kazunari; Ikenouchi-Sugita, Atsuko; Nakayama, Yasuko; Yoshioka, Haruna; Nomura, Takashi; Sakabe, Jun-Ichi; Nakahigashi, Kyoko; Kuroda, Etsushi; Uematsu, Satoshi; Nakamura, Jun; Akira, Shizuo; Nakamura, Motonobu; Narumiya, Shuh; Miyachi, Yoshiki; Tokura, Yoshiki; Kabashima, Kenji

    2013-10-01

    Pellagra is a photosensitivity syndrome characterized by three ``D's'': diarrhea, dermatitis, and dementia as a result of niacin deficiency. However, the molecular mechanisms of photosensitivity dermatitis, the hallmark abnormality of this syndrome, remain unclear. We prepared niacin deficient mice in order to develop a murine model of pellagra. Niacin deficiency induced photosensitivity and severe diarrhea with weight loss. In addition, niacin deficient mice exhibited elevated expressions of COX-2 and PGE syntheses (Ptges) mRNA. Consistently, photosensitivity was alleviated by a COX inhibitor, deficiency of Ptges, or blockade of EP4 receptor signaling. Moreover, enhanced PGE2 production in niacin deficiency was mediated via ROS production in keratinocytes. In line with the above murine findings, human skin lesions of pellagra patients confirmed the enhanced expression of Ptges. Niacin deficiency-induced photosensitivity was mediated through EP4 signaling in response to increased PGE2 production via induction of ROS formation.

  7. Characterization of the EP receptor types that mediate longitudinal smooth muscle contraction of human colon, mouse colon and mouse ileum.

    PubMed

    Fairbrother, S E; Smith, J E; Borman, R A; Cox, H M

    2011-08-01

    Prostaglandin E(2) (PGE(2) ) is an inflammatory mediator implicated in several gastrointestinal pathologies that affect normal intestinal transit. The aim was to establish the contribution of the four EP receptor types (EP(1-4) ), in human colon, that mediate PGE(2) -induced longitudinal smooth muscle contraction. Changes in isometric muscle tension of human colon, mouse colon and mouse ileum were measured in organ baths in response to receptor-specific agonists and antagonists. In addition, lidocaine was used to block neurogenic activity to investigate whether EP receptors were pre- or post-junctional. PGE(2) contracted longitudinal muscle from human and mouse colon and mouse ileum. These contractions were inhibited by the EP(1) receptor antagonist, EP(1) A in human colon, whereas a combination of EP(1) A and the EP(3) antagonist, L798106 inhibited agonist responses in both mouse preparations. The EP(3) agonist, sulprostone also increased muscle tension in both mouse tissues, and these responses were inhibited by lidocaine in the colon but not in the ileum. Although PGE(2) consistently contracted all three muscle preparations, butaprost decreased tension by activating smooth muscle EP(2) receptors in both colonic tissues. Alternatively, in mouse ileum, butaprost responses were lidocaine-sensitive, suggesting that it was activating prejunctional EP(2) receptors on inhibitory motor neurons. Conversely, EP(4) receptors were not functional in all the intestinal muscle preparations tested. PGE(2) -induced contraction of longitudinal smooth muscle is mediated by EP(1) receptors in human colon and by a combination of EP(1) and EP(3) receptors in mouse intestine, whereas EP(2) receptors modulate relaxation in all three preparations. © 2011 Blackwell Publishing Ltd.

  8. Prostaglandin E2 enhances long-term repopulation but does not permanently alter inherent stem cell competitiveness.

    PubMed

    Hoggatt, Jonathan; Mohammad, Khalid S; Singh, Pratibha; Pelus, Louis M

    2013-10-24

    Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for malignant and nonmalignant hematologic diseases and metabolic disorders. Although successful, hematopoietic transplantation can be hindered by inadequate stem cell number or poor engrafting efficiency. To overcome these deficits, we and others have previously reported the HSC-enhancing ability of a short-term exposure of prostaglandin E2 (PGE2); this strategy has now progressed to phase 1 clinical trials in double cord blood transplantation. To further analyze the short- and long-term effects of HSC exposure to PGE2, we followed the repopulation kinetics of PGE2-treated hematopoietic grafts through 5 serial transplantations and compared inherent long-term competitiveness in a HSC head-to-head secondary transplantation model. Treatment with PGE2 did not result in a long-term increase in HSC competitiveness, lineage bias, or enhanced proliferative potential, demonstrating that pulse exposure to PGE2 results in transient increases in HSC homing and engraftment potential.

  9. Hit-to-lead optimization of phenylsulfonyl hydrazides for a potent suppressor of PGE2 production: Synthesis, biological activity, and molecular docking study.

    PubMed

    Kim, Minju; Lee, Sunhoe; Park, Eun Beul; Kim, Kwang Jong; Lee, Hwi Ho; Shin, Ji-Sun; Fischer, Katrin; Koeberle, Andreas; Werz, Oliver; Lee, Kyung-Tae; Lee, Jae Yeol

    2016-01-01

    Preliminary hit-to-lead optimization of a novel series of phenylsulfonyl hydrazide derivatives, which were derived from the high throughput screening hit compound 1 (IC50=5700nM against PGE2 production), for a potent suppressor of PGE2 production is described. Subsequent optimization led to the identification of the potent lead compound 8n with IC50 values of 4.5 and 6.9nM, respectively, against LPS-induced PGE2 production and NO production in RAW 264.7 macrophage cells. In addition, 8n was about 30- and >150-fold more potent against mPGES-1 enzyme in a cell-free assay (IC50=70nM) than MK-886 and hit compound 1, respectively. Molecular docking suggests that compound 8n could inhibit PGE2 production by blocking the PGH2 binding site of human mPGES-1 enzyme. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Covalent modification of proteins by ligands of steroid hormone receptors.

    PubMed Central

    Takahashi, N; Breitman, T R

    1992-01-01

    Retinoylation, acylation with retinoic acid (RA), is a covalent modification of proteins occurring in a variety of eukaryotic cell lines. In this study, we found that proteins in HL-60 cells were labeled by 17 beta-[3H]estradiol (E2), [3H]progesterone (Pg), 1 alpha,25-dihydroxy[3H]vitamin D3 [1,25(OH)2D3], [125I]triiodothyronine (T3), [125I]thyroxine (T4), and [3H]prostaglandin E2 (PGE2). All of these hormones, except PGE2, are ligands of the steroid hormone receptor family. Addition to the growth medium of 5 microM ketoconazole, an inhibitor of cytochrome P450-dependent enzymes, increased about 2-fold the labeling of proteins by T3, T4, 1,25(OH)2D3, and PGE2. In contrast, ketoconazole did not change markedly the extent of labeling by RA, E2, or Pg. Alkaline methanolysis, which cleaves ester bonds, released variable percentages of the radioactive ligands bound to protein. These values were about 80% for RA and PGE2; 50% for T3, T4, and Pg; and 20% for E2 and 1,25(OH)2D3. Treatment with thioether-cleavage reagents, iodomethane or Raney nickel catalyst, released < 2% of the covalently bound ligands. Two-dimensional polyacrylamide gel electrophoresis patterns of labeled proteins were unique for each ligand. Proteins of M(r) 47,000 and 51,000 were labeled by RA, E2, T3, and T4. These proteins had the same mobilities as RI and RII, the cAMP-binding regulatory subunits of type I and type II cAMP-dependent protein kinases. 1,25(OH)2D3 also bound to proteins of M(r) 47,000 and 51,000. However, these proteins had pI values different from those of RI or RII. These results suggest that some activities of ligands of the steroid hormone receptor family and of PGE2 may be mediated by their covalent modification of proteins. Images PMID:1438281

  11. Covalent modification of proteins by ligands of steroid hormone receptors.

    PubMed

    Takahashi, N; Breitman, T R

    1992-11-15

    Retinoylation, acylation with retinoic acid (RA), is a covalent modification of proteins occurring in a variety of eukaryotic cell lines. In this study, we found that proteins in HL-60 cells were labeled by 17 beta-[3H]estradiol (E2), [3H]progesterone (Pg), 1 alpha,25-dihydroxy[3H]vitamin D3 [1,25(OH)2D3], [125I]triiodothyronine (T3), [125I]thyroxine (T4), and [3H]prostaglandin E2 (PGE2). All of these hormones, except PGE2, are ligands of the steroid hormone receptor family. Addition to the growth medium of 5 microM ketoconazole, an inhibitor of cytochrome P450-dependent enzymes, increased about 2-fold the labeling of proteins by T3, T4, 1,25(OH)2D3, and PGE2. In contrast, ketoconazole did not change markedly the extent of labeling by RA, E2, or Pg. Alkaline methanolysis, which cleaves ester bonds, released variable percentages of the radioactive ligands bound to protein. These values were about 80% for RA and PGE2; 50% for T3, T4, and Pg; and 20% for E2 and 1,25(OH)2D3. Treatment with thioether-cleavage reagents, iodomethane or Raney nickel catalyst, released < 2% of the covalently bound ligands. Two-dimensional polyacrylamide gel electrophoresis patterns of labeled proteins were unique for each ligand. Proteins of M(r) 47,000 and 51,000 were labeled by RA, E2, T3, and T4. These proteins had the same mobilities as RI and RII, the cAMP-binding regulatory subunits of type I and type II cAMP-dependent protein kinases. 1,25(OH)2D3 also bound to proteins of M(r) 47,000 and 51,000. However, these proteins had pI values different from those of RI or RII. These results suggest that some activities of ligands of the steroid hormone receptor family and of PGE2 may be mediated by their covalent modification of proteins.

  12. Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression.

    PubMed

    Ramos, Gerardo; Kazimi, Nasser; Nghiem, Dat X; Walterscheid, Jeffrey P; Ullrich, Stephen E

    2004-03-15

    Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependent manner. The release of biological response modifiers, particularly prostaglandin E2 (PGE2), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE2 secretion. Jet fuel-induced PGE2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin.

  13. Differential expression of upstream stimulatory factor (USF) 2 variants in eutopic endometria from women with endometriosis: estradiol regulation.

    PubMed

    Castro, Jazmin; Araya, Germán; Inostroza, Pamela; Hidalgo, Paulina; González-Ramos, Reinaldo; Sovino, Hugo; Boric, M Angélica; Fuentes, Ariel; Johnson, M Cecilia

    2015-10-09

    Endometriosis, pro-inflammatory and invasive benign disease estrogen dependent, abnormally express in endometria the enzyme P450Arom, positively regulated by steroid factor-1 (SF-1). Our objective was to study the nuclear protein contents of upstream stimulating factor 2 (USF2a and USF2b), a positive regulator of SF-1, throughout the menstrual cycle in eutopic endometria from women with and without (control) endometriosis and the involvement of nuclear estrogen receptors (ER) and G-coupled protein estrogen receptor (GPER)-1. Upstream stimulating factor 2 protein contents were higher in mid (USF2b) and late (USF2a and USF2b) secretory phase in eutopic endometria from endometriosis than control (p < 0.05). In isolated control epithelial cells incubated with E2 and PGE2, to resemble the endometriosis condition, the data showed: (a) significant increase of USF2a and USF2b nuclear protein contents when treated with E2, PPT (specific agonist for ERα) or G1 (specific agonist for GPER1); (b) no increase in USF2 binding to SF-1 E-Box/DNA consensus sequence in E2-treated cells; (c) USF2 variants protein contents were not modified by PGE2; (d) SF-1 nuclear protein content was significantly higher than basal when treated with PGE2, E2 or G1, stimulation unaffected by ICI (nuclear ER antagonist); and (e) increased (p < 0.05) cytosolic protein contents of P450Arom when treated with PGE2, E2, PPT or G1 compared to basal, effect that was additive with E2 + PGE2 together. Nevertheless, in endometriosis cells, the high USF2, SF-1 and P450Arom protein contents in basal condition were unmodified. These data strongly suggest that USF2 variants and P450Arom are regulated by E2 through ERα and GPER1, whereas SF-1 through GPER1, visualized by the response of the cells obtained from control endometria, being unaffected the endogenously stimulated cells from endometriosis origin. The lack of E2 stimulation on USF2/SF-1 E-Box/DNA-sequence binding and the absence of PGE2 effect on USF

  14. Role of carbonic anhydrase in bone resorption induced by prostaglandin E2 in vitro

    NASA Technical Reports Server (NTRS)

    Hall, G. E.; Kenny, A. D.

    1985-01-01

    The possible role of carbonic anhydrase in bone resorption induced by prostaglandin E2 (PGE2) was studied using an in vitro neonatal mouse calvarial culture system. PGE2 (10 to the -6th M) was effective in stimulating resorption, as assessed by calcium release into culture media. This enhanced resorption was accompanied by significant increases in calvarial carbonic anhydrase activity over control values at 48 and 96 h. At 48 h, bones treated with PGE2 had 20 percent more carbonic anhydrase activity than controls. By 96 h, treated bones contained 79 percent more carbonic anhydrase activity than controls. PGE2-induced bone resorption was inhibited by the carbonic anhydrase inhibitor acetazolamide in a dose-dependent fashion from 10 to the -5th to 10 to the -4th M with 77 percent inhibition observed at 10 to the -4th M. The acetazolamide analogue CL 13,850 (N-t-butylacetazolamide), which does not inhibit carbonic anhydrase, failed to inhibit PGE2-induced resorption. These results are consistent with the hypothesis that carbonic anhydrase is a necessary component of the osteoclastic bone resorptive mechanism.

  15. Regulation of Calcium Channels and Exocytosis in Mouse Adrenal Chromaffin Cells by Prostaglandin EP3 Receptors

    PubMed Central

    Jewell, Mark L.; Breyer, Richard M.

    2011-01-01

    Prostaglandin (PG) E2 controls numerous physiological functions through a family of cognate G protein-coupled receptors (EP1–EP4). Targeting specific EP receptors might be therapeutically useful and reduce side effects associated with nonsteroidal anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors that block prostanoid synthesis. Systemic immune challenge and inflammatory cytokines have been shown to increase expression of the synthetic enzymes for PGE2 in the adrenal gland. Catecholamines and other hormones, released from adrenal chromaffin cells in response to Ca2+ influx through voltage-gated Ca2+ channels, play central roles in homeostatic function and the coordinated stress response. However, long-term elevation of circulating catecholamines contributes to the pathogenesis of hypertension and heart failure. Here, we investigated the EP receptor(s) and cellular mechanisms by which PGE2 might modulate chromaffin cell function. PGE2 did not alter resting intracellular [Ca2+] or the peak amplitude of nicotinic acetylcholine receptor currents, but it did inhibit CaV2 voltage-gated Ca2+ channel currents (ICa). This inhibition was voltage-dependent and mediated by pertussis toxin-sensitive G proteins, consistent with a direct Gβγ subunit-mediated mechanism common to other Gi/o-coupled receptors. mRNA for all four EP receptors was detected, but using selective pharmacological tools and EP receptor knockout mice, we demonstrated that EP3 receptors mediate the inhibition of ICa. Finally, changes in membrane capacitance showed that Ca2+-dependent exocytosis was reduced in parallel with ICa. To our knowledge, this is the first study of EP receptor signaling in mouse chromaffin cells and identifies a molecular mechanism for paracrine regulation of neuroendocrine function by PGE2. PMID:21383044

  16. Prostaglandin E2 Regulation of Chondrocyte Proliferation and Differentiation

    DTIC Science & Technology

    1994-05-01

    lipopolysaccharide- and TNF-induced cartilage breakdown in bovine nasal cartilage(121’. The use of medications that modulate PGE2 production may have an adverse...Levine, P. Goldhaber. 1972. Evidence that the bone resorption stimulating factor produced by mouse fibrosarcoma cells is prostaglandin E2. J. Exp. Med

  17. [IL-1beta and PGE2 production in whole blood and gingival fluid in women with periodontitis and preterm low birth weight].

    PubMed

    Konopka, Tomasz; Rutkowska, Monika; Hirnle, Lidia; Kopeć, Wacław

    2004-05-01

    The aim of the investigation was to evaluate of IL-1beta and PGE2 concentrations in gingival fluid, whole blood as well as IL-1beta, PGE2 production after Escherichia coli lipopolysaccharide stimulation in whole blood in women with preterm low birth weight (PLBW), as compared to the control group. A case-control study of 88 postpartum women aged 17 to 39 was performed. The case group consisted of 52 women with PLBW and the control group consisted of 36 women giving birth in time. Concentration of inflammatory mediators in gingival fluid, blood serum and IL-1beta, PGE2 production in whole blood after bacterial lipopolysaccharide stimulation were determined by means of immunoenzymatic method. The levels of IL-1beta and PGE2 in gingival fluid were significantly higher in all PLBW mothers (also PLBW primiparous) than in the control group. In addition in the primiparous with PLBW group significantly higher PGE2 concentration in blood serum was found compared to the primiparous controls. There were no significant differences between women with PLBW and the controls together with a significantly higher production of IL-1beta and PGE2 in whole blood after LPS stimulation in women with periodontitis and gingivitis compared to subjects with healthy periodontium. Such findings suggest that inflammatory mediator synthesis is mainly result of specific cells exposition to bacterial products. Therefore it seems that more frequent occurrence of the phenotype of hyperactive cells that synthesise these mediators is not responsible for PLBW.

  18. Pivotal role of PGE2 and IL-10 in the cross-regulation of dendritic cell-derived inflammatory mediators.

    PubMed

    Harizi, Hedi; Gualde, Norbert

    2006-08-01

    Exposure to pathogens induces antigen-presenting cells (APC) such as macrophages and dendritic cells (DC) to produce various endogenous mediators, including arachidonic acid (AA)-derived eicosanoids, cytokines, and nitric oxide (NO). Many secreted products of activated APC can act by themselves in an autocrine manner and modulate their function. Moreover, the cross-interaction between endogenous bioactive molecules regulates the function of professional APC with important consequences for their ability to activate and sustain immune and inflammatory responses, and to regulate immune homeostasis. Although neglected for many years when compared to their role in cardiovascular homeostasis, cancer and inflammation, the importance of eicosanoids in immunology is becoming more defined. The role of prostaglandin (PG) E2 (PGE2), one of the best known and most well studied eicosanoids, is of particular interest. It modulates the activities of professional DC by acting on their differentiation, maturation and their ability to secrete cytokines. Uniquely among haematopoietic cytokines, interleukin-10 (IL-10) is a pleiotropic molecule that displays both immunostimulatory and immunoregulatory activities. IL-10 has attached much attention because of its anti-inflammatory properties. It modulates expression of cytokines, soluble mediators and cell surface molecules by cells of myeloid origin, particularly macrophages and DC. We previously reported that PGE2 is a potent inducer of IL-10 in bone marrow-derived DC (BM-DC), and PGE2-induced IL-10 is a key regulator of the BM-DC pro-inflammatory phenotype. BM-DC may be considered as an important model to study complex interactions between endogenous mediators, and autocrine IL-10 plays a pivotal role in the crossregulation of AA-derived lipid mediators, cytokines, and NO, with critical effects on immune and inflammatory responses.

  19. Prostaglandin E2 Activates YAP and a Positive-Signaling Loop to Promote Colon Regeneration After Colitis but Also Carcinogenesis in Mice.

    PubMed

    Kim, Han-Byul; Kim, Minchul; Park, Young-Soo; Park, Intae; Kim, Tackhoon; Yang, Sung-Yeun; Cho, Charles J; Hwang, DaeHee; Jung, Jin-Hak; Markowitz, Sanford D; Hwang, Sung Wook; Yang, Suk-Kyun; Lim, Dae-Sik; Myung, Seung-Jae

    2017-02-01

    Prostaglandin E 2 (PGE 2 ) is mediator of inflammation that regulates tissue regeneration, but its continual activation has been associated with carcinogenesis. Little is known about factors in the PGE 2 signaling pathway that contribute to tumor formation. We investigated whether yes-associated protein 1 (YAP1), a transcriptional co-activator in the Hippo signaling pathway, mediates PGE 2 function. DLD-1 and SW480 colon cancer cell lines were transfected with vectors expressing transgenes or small hairpin RNAs and incubated with recombinant PGE 2 , with or without pharmacologic inhibitors of signaling proteins, and analyzed by immunoblot, immunofluorescence, quantitative reverse-transcription polymerase chain reaction, transcriptional reporter, and proliferation assays. Dextran sodium sulfate (DSS) was given to induce colitis in C57/BL6 (control) mice, as well as in mice with disruption of the hydroxyprostaglandin dehydrogenase 15 gene (15-PGDH-knockout mice), Yap1 gene (YAP-knockout mice), and double-knockout mice. Some mice also were given indomethacin to block PGE 2 synthesis. 15-PGDH knockout mice were crossed with mice with intestine-specific disruption of the salvador family WW domain containing 1 gene (Sav1), which encodes an activator of Hippo signaling. We performed immunohistochemical analyses of colon biopsy samples from 26 patients with colitis-associated cancer and 51 age-and sex-matched patients with colorectal cancer (without colitis). Incubation of colon cancer cell lines with PGE 2 led to phosphorylation of cyclic adenosine monophosphate-responsive element binding protein 1 and increased levels of YAP1 messenger RNA, protein, and YAP1 transcriptional activity. This led to increased transcription of the prostaglandin-endoperoxide synthase 2 gene (PTGS2 or cyclooxygenase 2) and prostaglandin E-receptor 4 gene (PTGER4 or EP4). Incubation with PGE 2 promoted proliferation of colon cancer cell lines, but not cells with knockdown of YAP1. Control mice

  20. Regulation of PGE2 signaling pathways and TNF-alpha signaling pathways on the function of bone marrow-derived dendritic cells and the effects of CP-25.

    PubMed

    Li, Ying; Sheng, Kangliang; Chen, Jingyu; Wu, Yujing; Zhang, Feng; Chang, Yan; Wu, Huaxun; Fu, Jingjing; Zhang, Lingling; Wei, Wei

    2015-12-15

    This study was to investigate PGE2 and TNF-alpha signaling pathway involving in the maturation and activation of bone marrow dendritic cells (DCs) and the effect of CP-25. Bone marrow DCs were isolated and stimulated by PGE2 and TNF-alpha respectively. The markers of maturation and activation expressed on DCs, such as CD40, CD80, CD83, CD86, MHC-II, and the ability of antigen uptake of DCs were analyzed by flow cytometry. The proliferation of T cells co-cultured with DCs, the signaling pathways of PGE2-EP4-cAMP and TNF-alpha-TRADD-TRAF2-NF-κB in DCs were analyzed. The results showed that both PGE2 and TNF-alpha up-regulated the expressions of CD40, CD80, CD83, CD86, and MHC-II, decreased the antigen uptake of DCs, and DCs stimulated by PGE2 or TNF-alpha could increase T cell proliferation. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased significantly the expressions of CD40, CD80, CD83, CD86 and MHC-II, increased the antigen uptake of DCs, and suppressed T cell proliferation induced by DCs. PGE2 increased the expressions of EP4, NF-κB and down-regulated cAMP level of DCs. TNF-alpha could also up-regulate TNFR1, TRADD, TRAF2, and NF-κB expression of DCs. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased the expressions of EP4 and NF-κB, increased cAMP level in DCs stimulated by PGE2. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) also could down-regulate significantly TNFR1, TRADD, TRAF2, and NF-κB expression in DCs stimulated by TNF-alpha. These results demonstrate that PGE2 and TNF-alpha could enhance DCs functions by mediating PGE2-EP4-cAMP pathway, TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathway respectively. CP-25 might inhibit the function of DCs through regulating PGE2-EP4-cAMP and TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Caveolin-1–mediated Suppression of Cyclooxygenase-2 via a β-catenin-Tcf/Lef–dependent Transcriptional Mechanism Reduced Prostaglandin E2 Production and Survivin Expression

    PubMed Central

    Rodriguez, Diego A.; Tapia, Julio C.; Fernandez, Jaime G.; Torres, Vicente A.; Muñoz, Nicolas; Galleguillos, Daniela; Leyton, Lisette

    2009-01-01

    Augmented expression of cyclooxygenase-2 (COX-2) and enhanced production of prostaglandin E2 (PGE2) are associated with increased tumor cell survival and malignancy. Caveolin-1 is a scaffold protein that has been proposed to function as a tumor suppressor in human cancer cells, although mechanisms underlying this ability remain controversial. Intriguingly, the possibility that caveolin-1 regulates the expression of COX-2 has not been explored. Here we show that augmented caveolin-1 expression in cells with low basal levels of this protein, such as human colon cancer (HT29, DLD-1), breast cancer (ZR75), and embryonic kidney (HEK293T) cells reduced COX-2 mRNA and protein levels and β-catenin-Tcf/Lef and COX-2 gene reporter activity, as well as the production of PGE2 and cell proliferation. Moreover, COX-2 overexpression or PGE2 supplementation increased levels of the inhibitor of apoptosis protein survivin by a transcriptional mechanism, as determined by PCR analysis, survivin gene reporter assays and Western blotting. Furthermore, addition of PGE2 to the medium prevented effects attributed to caveolin-1–mediated inhibition of β-catenin-Tcf/Lef–dependent transcription. Finally, PGE2 reduced the coimmunoprecipitation of caveolin-1 with β-catenin and their colocalization at the plasma membrane. Thus, by reducing COX-2 expression, caveolin-1 interrupts a feedback amplification loop involving PGE2-induced signaling events linked to β-catenin/Tcf/Lef–dependent transcription of tumor survival genes including cox-2 itself and survivin. PMID:19244345

  2. Angiogenesis in the Primate Ovulatory Follicle Is Stimulated by Luteinizing Hormone via Prostaglandin E21

    PubMed Central

    Trau, Heidi A.; Davis, John S.; Duffy, Diane M.

    2014-01-01

    ABSTRACT Rapid angiogenesis occurs as the ovulatory follicle is transformed into the corpus luteum. To determine if luteinizing hormone (LH)-stimulated prostaglandin E2 (PGE2) regulates angiogenesis in the ovulatory follicle, cynomolgus macaques received gonadotropins to stimulate multiple follicular development and chorionic gonadotropin (hCG) substituted for the LH surge to initiate ovulatory events. Before hCG, vascular endothelial cells were present in the perifollicular stroma but not amongst granulosa cells. Endothelial cells entered the granulosa cell layer 24–36 h after hCG, concomitant with the rise in follicular PGE2 and prior to ovulation, which occurs about 40 h after hCG. Intrafollicular administration of the PG synthesis inhibitor indomethacin was coupled with PGE2 replacement to demonstrate that indomethacin blocked and PGE2 restored follicular angiogenesis in a single, naturally developed monkey follicle in vivo. Intrafollicular administration of indomethacin plus an agonist selective for a single PGE2 receptor showed that PTGER1 and PTGER2 agonists most effectively stimulated angiogenesis within the granulosa cell layer. Endothelial cell tracing and three-dimensional reconstruction indicated that these capillary networks form via branching angiogenesis. To further explore how PGE2 mediates follicular angiogenesis, monkey ovarian microvascular endothelial cells (mOMECs) were isolated from ovulatory follicles. The mOMECs expressed all four PGE2 receptors in vitro. PGE2 and all PTGER agonists increased mOMEC migration. PTGER1 and PTGER2 agonists promoted sprout formation while the PTGER3 agonist inhibited sprouting in vitro. While PTGER1 and PTGER2 likely promote the formation of new capillaries, each PGE2 receptor may mediate aspects of PGE2's actions and, therefore, LH's ability to regulate angiogenesis in the primate ovulatory follicle. PMID:25376231

  3. Production of New Trabecular Bone in Osteopenic Ovariectomized Rats by Prostaglandin E2

    NASA Technical Reports Server (NTRS)

    Mori, S.; Jee, W. S. S.; Li, X. J.

    1992-01-01

    Serum chemistry and bone morphometry of the proximal tibial metaphysis were performed in 3 month-old double fluorescent-labeled, female Sprague-Dawley rats subjected to bilateral ovariectomy or sham surgery for 4 months prior to treatment with 0, 0.3, 1,3, or 6 mg of prostaglandin E2 (PGE2)/kg/day subcutaneously for 30 days. The 4 month postovariectomized rats possessed an osteopenic proximal tibial metaphysis with 7% trabecular area compared with controls (19%). PGE2 treatment elevated osteocalcin levels and augmented proximal tibial metaphyseal bone area in ovariectomized and sham-operated rats. Osteopenic, ovariectomized rats treated with 6 mg (PGE2)/kg/day for 30 days restored bone area to levels of agematched sham-operated rats. Morphometric analyses showed increased woven and lamellar bone area, fluorescent-labeled perimeter (osteoblastic recruitment), mineral apposition rate (osteoblastic activity), bone formation rate (BFR/BV), and longitudinal bone growth. These dramatic bone changes were all significantly increased at the doseresponse manner. This study showed that in vivo PGE2 is a powerful activator of bone remodeling, it increases both bone resorption and bone formation, and produces an anabolic effect by shifting bone balance to the positive direction. Furthermore, PGE2-induced augmentation of metaphyseal bone area in ovariectomized rats was at least two times greater than in sham-operated rats.

  4. An EP2 Agonist Facilitates NMDA-Induced Outward Currents and Inhibits Dendritic Beading through Activation of BK Channels in Mouse Cortical Neurons

    PubMed Central

    Hayashi, Yoshinori; Morinaga, Saori; Liu, Xia; Zhang, Jing; Wu, Zhou; Yokoyama, Takeshi; Nakanishi, Hiroshi

    2016-01-01

    Prostaglandin E2 (PGE2), a major metabolite of arachidonic acid produced by cyclooxygenase pathways, exerts its bioactive responses by activating four E-prostanoid receptor subtypes, EP1, EP2, EP3, and EP4. PGE2 enables modulating N-methyl-D-aspartate (NMDA) receptor-mediated responses. However, the effect of E-prostanoid receptor agonists on large-conductance Ca2+-activated K+ (BK) channels, which are functionally coupled with NMDA receptors, remains unclear. Here, we showed that EP2 receptor-mediated signaling pathways increased NMDA-induced outward currents (I NMDA-OUT), which are associated with the BK channel activation. Patch-clamp recordings from the acutely dissociated mouse cortical neurons revealed that an EP2 receptor agonist activated I NMDA-OUT, whereas an EP3 receptor agonist reduced it. Agonists of EP1 or EP4 receptors showed no significant effects on I NMDA-OUT. A direct perfusion of 3,5′-cyclic adenosine monophosphate (cAMP) through the patch pipette facilitated I NMDA-OUT, which was abolished by the presence of protein kinase A (PKA) inhibitor. Furthermore, facilitation of I NMDA-OUT caused by an EP2 receptor agonist was significantly suppressed by PKA inhibitor. Finally, the activation of BK channels through EP2 receptors facilitated the recovery phase of NMDA-induced dendritic beading in the primary cultured cortical neurons. These results suggest that a direct activation of BK channels by EP2 receptor-mediated signaling pathways plays neuroprotective roles in cortical neurons. PMID:27298516

  5. Prostaglandin D2 effects and DP1 /DP2 receptor distribution in guinea pig urinary bladder out-flow region.

    PubMed

    Guan, Na N; Svennersten, Karl; de Verdier, Petra J; Wiklund, N Peter; Gustafsson, Lars E

    2017-02-01

    The proximal urethra and urinary bladder trigone play important roles in continence. We have previously shown that PGD 2 is released from guinea pig bladder urothelium/suburothelium and can inhibit detrusor contractile responses. We presently wished to investigate PGD 2 actions in guinea pig out-flow region and the distribution of DP 1 /DP 2 receptors. The effects of PGD 2 on urothelium-intact trigone and proximal urethra contractility were studied in organ bath experiments. Expression of DP 1 /DP 2 receptor proteins was analysed by western blot. Immunohistochemistry was used to identify distribution of DP 1 /DP 2 receptors. PGD 2 in a dose-dependent manner inhibited trigone contractions induced by electrical field stimulation (EFS) and inhibited spontaneous contractions of the proximal urethra. PGD 2 was equally (trigone) or slightly less potent (urethra) compared with PGE 2 . Expression of DP 1 and DP 2 receptors was found in male guinea pig bladder trigone, neck and proximal urethra. In the trigone and proximal urethra, DP 1 receptors were found on the membrane of smooth muscle cells and weak immunoreactivty was observed in the urothelium. DP 2 receptors were distributed more widespread, weakly and evenly in the urothelium and smooth muscles. Inhibitory effects by PGD 2 on motor activity of guinea pig trigone and proximal urethra are consistent with finding DP 1 and DP 2 receptors located in the urothelium and smooth muscle cells of the trigone and proximal urethra, and PGD 2 may therefore be a modulator of the bladder out-flow region, possibly having a function in regulation of micturition and a role in overactive bladder syndrome. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  6. Increased urinary prostaglandin E2 metabolite: A potential therapeutic target of Gitelman syndrome.

    PubMed

    Peng, Xiaoyan; Jiang, Lanping; Chen, Chen; Qin, Yan; Yuan, Tao; Wang, Ou; Xing, Xiaoping; Li, Xuemei; Nie, Min; Chen, Limeng

    2017-01-01

    Gitelman syndrome (GS), an inherited autosomal recessive salt-losing renal tubulopathy caused by mutations in SLC12A3 gene, has been associated with normal prostaglandin E2 (PGE2) levels since 1995 by a study involving 11 clinically diagnosed patients. However, it is difficult to explain why cyclooxygenase-2 (COX2) inhibitors, which pharmacologically reduce PGE2 synthesis, are helpful to patients with GS, and few studies performed in the last 20 years have measured PGE2 levels. The relationships between the clinical manifestations and PGE2 levels were never thoroughly analyzed. This study involved 39 GS patients diagnosed by SLC12A3 gene sequencing. Plasma and 24-h urine samples as well as the clinical data were collected at admission. PGE2 and PGEM levels were detected in plasma and urine samples by enzyme immunoassays. The in vivo function of the sodium-chloride co-transporter (NCC) in GS patients was evaluated using a modified thiazide test. The association among PGE2 levels, clinical manifestations and the function of NCC in GS patients were analyzed. Significantly higher levels of urinary and plasma PGEM were observed in GS patients than in the healthy volunteers. Higher urinary PGEM levels indicated more severe clinical manifestations and NCC dysfunction estimated by the increase of Cl- clearance. A higher PGEM level was found in male GS patients, who showed earlier onset age and more severe hypokalemia, hypochloremia and metabolic alkalosis than female GS patients. No relationship between renin angiotensin aldosterone system activation and PGEM level was observed. Higher urinary PGEM levels indicated more severe clinical manifestations and NCC dysfunction in GS patients. COX2 inhibition might be a potential therapeutic target in GS patients with elevated PGEM levels.

  7. Apolipoprotein E Is a Ligand for Triggering Receptor Expressed on Myeloid Cells 2 (TREM2)*

    PubMed Central

    Atagi, Yuka; Liu, Chia-Chen; Painter, Meghan M.; Chen, Xiao-Fen; Verbeeck, Christophe; Zheng, Honghua; Li, Xia; Rademakers, Rosa; Kang, Silvia S.; Xu, Huaxi; Younkin, Steven; Das, Pritam; Fryer, John D.; Bu, Guojun

    2015-01-01

    Several heterozygous missense mutations in the triggering receptor expressed on myeloid cells 2 (TREM2) have recently been linked to risk for a number of neurological disorders including Alzheimer disease (AD), Parkinson disease, and frontotemporal dementia. These discoveries have re-ignited interest in the role of neuroinflammation in the pathogenesis of neurodegenerative diseases. TREM2 is highly expressed in microglia, the resident immune cells of the central nervous system. Along with its adaptor protein, DAP12, TREM2 regulates inflammatory cytokine release and phagocytosis of apoptotic neurons. Here, we report apolipoprotein E (apoE) as a novel ligand for TREM2. Using a biochemical assay, we demonstrated high-affinity binding of apoE to human TREM2. The functional significance of this binding was highlighted by increased phagocytosis of apoE-bound apoptotic N2a cells by primary microglia in a manner that depends on TREM2 expression. Moreover, when the AD-associated TREM2-R47H mutant was used in biochemical assays, apoE binding was vastly reduced. Our data demonstrate that apoE-TREM2 interaction in microglia plays critical roles in modulating phagocytosis of apoE-bound apoptotic neurons and establish a critical link between two proteins whose genes are strongly linked to the risk for AD. PMID:26374899

  8. Prostaglandin E2 alters Wnt-dependent migration and proliferation in neuroectodermal stem cells: implications for autism spectrum disorders

    PubMed Central

    2014-01-01

    Prostaglandin E2 (PGE2) is a natural lipid-derived molecule that is involved in important physiological functions. Abnormal PGE2 signalling has been associated with pathologies of the nervous system. Previous studies provide evidence for the interaction of PGE2 and canonical Wnt signalling pathways in non-neuronal cells. Since the Wnt pathway is crucial in the development and organization of the brain, the main goal of this study is to determine whether collaboration between these pathways exists in neuronal cell types. We report that PGE2 interacts with canonical Wnt signalling through PKA and PI-3K in neuroectodermal (NE-4C) stem cells. We used time-lapse microscopy to determine that PGE2 increases the final distance from origin, path length travelled, and the average speed of migration in Wnt-activated cells. Furthermore, PGE2 alters distinct cellular phenotypes that are characteristic of Wnt-induced NE-4C cells, which corresponds to the modified splitting behaviour of the cells. We also found that in Wnt-induced cells the level of β-catenin protein was increased and the expression levels of Wnt-target genes (Ctnnb1, Ptgs2, Ccnd1, Mmp9) was significantly upregulated in response to PGE2 treatment. This confirms that PGE2 activated the canonical Wnt signalling pathway. Furthermore, the upregulated genes have been previously associated with ASD. Our findings show, for the first time, evidence for cross-talk between PGE2 and Wnt signalling in neuronal cells, where PKA and PI-3K might act as mediators between the two pathways. Given the importance of PGE2 and Wnt signalling in prenatal development of the nervous system, our study provides insight into how interaction between these two pathways may influence neurodevelopment. PMID:24656144

  9. Prostaglandin E2 alters Wnt-dependent migration and proliferation in neuroectodermal stem cells: implications for autism spectrum disorders.

    PubMed

    Wong, Christine T; Ahmad, Eizaaz; Li, Hongyan; Crawford, Dorota A

    2014-03-23

    Prostaglandin E2 (PGE2) is a natural lipid-derived molecule that is involved in important physiological functions. Abnormal PGE2 signalling has been associated with pathologies of the nervous system. Previous studies provide evidence for the interaction of PGE2 and canonical Wnt signalling pathways in non-neuronal cells. Since the Wnt pathway is crucial in the development and organization of the brain, the main goal of this study is to determine whether collaboration between these pathways exists in neuronal cell types. We report that PGE2 interacts with canonical Wnt signalling through PKA and PI-3K in neuroectodermal (NE-4C) stem cells. We used time-lapse microscopy to determine that PGE2 increases the final distance from origin, path length travelled, and the average speed of migration in Wnt-activated cells. Furthermore, PGE2 alters distinct cellular phenotypes that are characteristic of Wnt-induced NE-4C cells, which corresponds to the modified splitting behaviour of the cells. We also found that in Wnt-induced cells the level of β-catenin protein was increased and the expression levels of Wnt-target genes (Ctnnb1, Ptgs2, Ccnd1, Mmp9) was significantly upregulated in response to PGE2 treatment. This confirms that PGE2 activated the canonical Wnt signalling pathway. Furthermore, the upregulated genes have been previously associated with ASD. Our findings show, for the first time, evidence for cross-talk between PGE2 and Wnt signalling in neuronal cells, where PKA and PI-3K might act as mediators between the two pathways. Given the importance of PGE2 and Wnt signalling in prenatal development of the nervous system, our study provides insight into how interaction between these two pathways may influence neurodevelopment.

  10. Ca(2+)-mediated prostaglandin E2 induction reduces haematoporphyrin-derivative-induced cytotoxicity of T24 human bladder transitional carcinoma cells in vitro.

    PubMed Central

    Penning, L C; Keirse, M J; VanSteveninck, J; Dubbelman, T M

    1993-01-01

    The effects of haematoporphyrin-derivative-mediated photodynamic treatment on arachidonic acid metabolism and its relation to clonogenicity have been studied in human bladder-tumour cells. Photodynamic treatment resulted in a transient release of arachidonic acid-derived compounds; prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) especially were strongly increased. This release was reduced by chelation of intracellular Ca2+ with Quin-2 or by lowering the extracellular Ca2+ concentration in the medium with EGTA, presumably resulting in inhibition of phospholipase A2. A similar reduction was obtained when indomethacin, an inhibitor of the cyclo-oxygenase pathway, was added prior to light exposure. These three treatments enhanced the photosensitivity, as revealed by the clonogenicity assay. Incubation with PGE2 prior to light exposure, but not with TXB2, protected against reproductive-cell death. The results of these experiments suggest that Ca(2+)-mediated activation of cyclo-oxygenase, resulting in increased levels of PGE2, participates in a cellular-defence mechanism against photodynamic cell killing. PMID:8503851

  11. Effect of a single intra-articular injection of bupivacaine on synovial fluid prostaglandin E2 concentrations in normal canine stifles.

    PubMed

    Giangarra, Jenna E; Barry, Sabrina L; Dahlgren, Linda A; Lanz, Otto I; Benitez, Marian E; Werre, Stephen R

    2018-04-25

    To identify if synovial fluid prostaglandin E 2 increases in response to a single intra-articular dose of bupivacaine in the normal canine stifle. There were no significant differences in synovial fluid prostaglandin E 2 (PGE 2 ) concentrations between treatment groups or over time within bupivacaine or saline groups. Samples requiring ≥ 3 arthrocentesis attempts had significantly higher PGE 2 concentrations compared to samples requiring 1 or 2 attempts. Following correction for number of arthrocentesis attempts, PGE 2 concentrations were significantly higher than baseline at 24 and 48 h in the bupivacaine group; however there were no significant differences between the bupivacaine and saline groups. In normal dogs, a single bupivacaine injection did not cause significant synovial inflammation, as measured by PGE 2 concentrations, compared to saline controls. Future research should minimize aspiration attempts and include evaluation of the synovial response to bupivacaine in clinical cases with joint disease.

  12. Gonadotropin-dependent regulation of the prostaglandin E2 receptor in equine preovulatory follicles during the ovulatory process in mares.

    PubMed

    Sayasith, Khampoune; Bouchard, Nadine; Doré, Monique; Sirois, Jean

    2009-02-01

    The objectives of the study were to clone the primary structure of the prostaglandin E2 receptor subtype 2 (PTGER2) cDNA and to characterize its regulation in equine follicles during gonadotropin-induced ovulation. Results from DNA isolation indicated that the equine PTGER2 cDNA encodes a predicted 353-amino acid protein, which is highly similar (76-85%) to known mammalian homologues. The regulation of PTGER2 was studied by semi-quantitative RT-PCR/Southern blot using preparations of theca interna and mural granulosa cells isolated from equine follicles 0-39 hr post-treatment with human chorionic gonadotropin (hCG). Results indicated that a significant increase of PTGER2 mRNA occurred at 24 and 39 hr post-hCG in granulosa cells, and 30 and 33 hr post-hCG in theca cells (P < 0.05). Immunohistochemical staining and immunoblotting performed on equine follicular samples showed a corresponding increase of PTGER2 protein in both cell types after treatment with hCG. Levels of PTGER2 mRNA were also high in uterus, thymus and spleen, but moderate to low in other tested tissues. In the ovary, the expression of PTGER4 mRNA was observed and predominantly occurred in granulosa cells, with highest abundance of transcripts observed at 12 and 39 hr post-hCG. Thus, this study reports for the first time in mares that the ovulatory process is accompanied by the gonadotropin-dependent up-regulation of PTGER2 and PTGER4, which may in turn regulate PGE2-mediated preovulatory effects. (c) 2008 Wiley-Liss, Inc.

  13. Release of LHRH-activity from human fetal membranes upon exposure to PGE/sub 2/, oxytocin and isoproterenol

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Poisner, A.M.; Poisner, R.; Becca, C.R.

    1986-03-01

    The authors have previously reported that superfused chorion laeve (fetal membranes) release LHRH-like immunoreactivity upon exposure to angiotensin II. They have now studied the effects of other agonists on the release of LHRH-activity and something of its chemical nature. Fetal membranes were obtained from placentas delivered by cesarean section, the amnion stripped from the chorion, and the chorion superfused in an Amicon thin-channel device with the maternal surface facing up. The whole device was submerged in a 37 C water bath and perfused with a modified Locke's solution at 0.4 - 1.0 ml/min. LHRH-activity was measured by radioimmunoassay using threemore » different antisera against LHRH. The release of LHRH-activity was stimulated by 6-10 min exposure to PGE/sub 2/, oxytocin, and isoproterenol. Extracts of chorion were studied using gel filtration on Sephacryl S-200 and ultrafiltration with Amicon PM-10 filters. The bulk of the LHRH-activity appeared as a higher molecular weight form (about 70,000 daltons). Since oxytocin has been reported to release PGE/sub 2/ from chorion, it may release LHRH-activity by virtue of liberating endogenous PGE/sub 2/. The chemical nature of the LHRH-activity is presently under investigation.« less

  14. Prostaglandin E2 and SOCS1 have a role in intestinal immune tolerance

    PubMed Central

    Chinen, Takatoshi; Komai, Kyoko; Muto, Go; Morita, Rimpei; Inoue, Naoko; Yoshida, Hideyuki; Sekiya, Takashi; Yoshida, Ryoko; Nakamura, Kazuhiko; Takayanagi, Ryoichi; Yoshimura, Akihiko

    2011-01-01

    Interleukin 10 (IL-10) and regulatory T cells (Tregs) maintain tolerance to intestinal microorganisms. However, Il10−/−Rag2−/− mice, which lack IL-10 and Tregs, remain healthy, suggesting the existence of other mechanisms of tolerance. Here, we identify suppressor of cytokine signalling 1 (SOCS1) as an essential mediator of immune tolerance in the intestine. Socs1−/−Rag2−/− mice develop severe colitis, which can be prevented by the reduction of microbiota and the transfer of IL-10-sufficient Tregs. Additionally, we find an essential role for prostaglandin E2 (PGE2) in the maintenance of tolerance within the intestine in the absence of Tregs. Socs1−/− dendritic cells are resistant to PGE2-mediated immunosuppression because of dysregulated cytokine signalling. Thus, we propose that SOCS1 and PGE2, potentially interacting together, act as an alternative intestinal tolerance mechanism distinct from IL-10 and Tregs. PMID:21304519

  15. NO2 inhalation promotes Alzheimer’s disease-like progression: cyclooxygenase-2-derived prostaglandin E2 modulation and monoacylglycerol lipase inhibition-targeted medication

    NASA Astrophysics Data System (ADS)

    Yan, Wei; Yun, Yang; Ku, Tingting; Li, Guangke; Sang, Nan

    2016-03-01

    Air pollution has been reported to be associated with increased risks of cognitive impairment and neurodegenerative diseases. Because NO2 is a typical primary air pollutant and an important contributor to secondary aerosols, NO2-induced neuronal functional abnormalities have attracted greater attention, but the available experimental evidence, modulating mechanisms, and targeting medications remain ambiguous. In this study, we exposed C57BL/6J and APP/PS1 mice to dynamic NO2 inhalation and found for the first time that NO2 inhalation caused deterioration of spatial learning and memory, aggravated amyloid β42 (Aβ42) accumulation, and promoted pathological abnormalities and cognitive defects related to Alzheimer’s disease (AD). The microarray and bioinformation data showed that the cyclooxygenase-2 (COX-2)-mediated arachidonic acid (AA) metabolism of prostaglandin E2 (PGE2) played a key role in modulating this aggravation. Furthermore, increasing endocannabinoid 2-arachidonoylglycerol (2-AG) by inhibiting monoacylglycerol lipase (MAGL) prevented PGE2 production, neuroinflammation-associated Aβ42 accumulation, and neurodegeneration, indicating a therapeutic target for relieving cognitive impairment caused by NO2 exposure.

  16. Prostaglandin E2 Increased Rat Cortical Bone Mass When Administered Immediately Following Ovariectomy

    NASA Technical Reports Server (NTRS)

    Ke, Hua Zhu; Jee, Webster S.S.; Zeng, Qing Qiang; Li, Mei; Lin, Bai Yun

    1993-01-01

    To investigate the effects of ovariectomy and the simultaneous administration of prostaglandin E2 (PGE2) on rat tibial shaft cortical bone histomorphometry, thirty-five 3 month-old female Sprague-Dawley rats were either ovariectomized (OVX), or sham ovariectomy (sham-OVX). The OVX rats were divided into three groups and treated with 0, 1 and 6 mg PGE2/kg/day for 90 days. The double fluorescent labeled undecalcified tibial shaft cross sections (proximal to the tibiofibular junction) of all the subjects were used for histomorphometry analysis. No differences in cross-sectional area and cortical bone area were found between sham-OVX and OVX controls, but OVX increased marrow area, intracortical porosity area and endocortical eroded perimeter. Periosteal and endocortical bone formation rates decreased with aging yet OVX prevented these changes. These OVX-induced increases in marrow area and endocortical eroded perimeter were prevented by 1 mg PGE2/kg/day treatment and added bone to periosteal and endocortical surfaces and to the marrow cavity. At the 6 mg/kg/day dose level, PGE2-treated OVX rats increased total tissue area, cortical bone area, marrow trabmular bone area, minimal cortical width and intracortical porosity area, and decreased marrow area compared to basal, sham-OVX and OVX controls. In addition, periosteal bone formation was elevated in the 6 mg PGE2/kg/day-treated OVX rats compared to OVX controls. Endocortical eroded perimeter increased from basal and sham-OVX control levels, but decreased from OVX control levels in the 6 mg PGE2/kg/day-treated OVX rats. Our study confirmed that ovariectomy does not cause osteopenia in tibial shaft cortical bone in rats, but it does stimulate endocortical bone resorption and enlarges marrow area. The new findings from the present study demonstrate that PGE2 prevents the OVX-induced increases in endocortical bone resorption and marrow area and adds additional bone to periosteal and endocortical surfaces and to marrow

  17. Prostaglandin E2-induced up-regulation of c-fos messenger ribonucleic acid is primarily mediated by 3',5'-cyclic adenosine monophosphate in MC3T3-E1 osteoblasts

    NASA Technical Reports Server (NTRS)

    Fitzgerald, J.; Dietz, T. J.; Hughes-Fulford, M.

    2000-01-01

    The mechanism by which the proto-oncogene, c-fos, is up-regulated in response to PGE2 in the mouse osteoblastic (MC3T3-E1) cell line was investigated using RT-PCR. c-fos messenger RNA up-regulation by dmPGE2 is rapid, starting 10 min post stimulation, and transient. The specific protein kinase A (PKA) inhibitor, H89, inhibited c-fos induction. Moreover, down-regulation of protein kinase C (PKC) activity by chronic TPA treatment had no effect on the induction of c-fos by dmPGE2. We conclude that up-regulation of c-fos by dmPGE2 is primarily dependent on PKA in MC3T3-E1 osteoblasts. In S49 lymphoma wild-type but not S49 cyc- cells, which are deficient in cAMP signaling, dmPGE2 up-regulates c-fos and increases cell growth compared with unstimulated cells. Thus in S49 lymphoma cells, c-fos induction by PGE2 is also dependent on cAMP signaling. The minimal c-fos promoter region required for dmPGE2-induced expression was identified by transfecting c-fos promoter deletion constructs coupled to the chloramphenicol acetyltransferase (CAT) reporter gene into Vero cells. Transfection of a plasmid containing 99 bp c-fos proximal promoter was sufficient to direct c-fos/CAT expression following stimulation with dmPGE2. Because induction of c-fos is mediated by cAMP, these data are consistent with activation of c-fos via the CRE/ATF cis element.

  18. Anabolic Responses of an Adult Cancellous Bone Site to Prostaglandin E2 in the Rat

    NASA Technical Reports Server (NTRS)

    Ito, Hiroshi; Ke, Hua Zhu; Jee, Webster S. S.; Sakou, Takashi

    1993-01-01

    The objects of this study were to determine: (1) the response of a non-growing cancellous bone site to daily prostaglandin E2 (PGE2) administration; and (2) the differences in the effects of daily PGE2, administration in growing (proximal tibial metaphysis, PTM) and non-growing cancellous bone sites (distal tibial metaphysis, DTM). Seven-month-old male Sprague-Dawley rats were given daily subcutaneous injections of 0, 1, 3 and 6 mg PGE2/kg per day for 60, 120 and 180 days. The static and dynamic histomorphometric analyses were performed on double-fluorescent labeled undecalcified distal tibial metaphyses (DTM). No age-related changes were found in static and dynamic histomorphometry of DTM cancellous bone between 7 and 13 months of age. The DTM of 7-month-old (basal controls) rats consisted of a 24.5 +/- 7.61%-metaphyseal cancellous bone mass, and a thick trabeculae (92 +/- 12 micro-m). It also had a very low tissue-base bone formation rate (3.0 +/- 7.31%/year). Exogenous PGE2 administration produced the following transient changes in a dose-response manner between zero and 60 days: (1) increased trabecular bone mass and improved architecture (increased trabecular bone area, width and number, and decreased trabecular separation); (2) increased trabecular interconnections: (3) increased bone formation parameters; and (4) decreased eroded perimeter. A new steady state with more cancellous bone mass and higher bone turnover was observed from day 60 onward, The elevated bone mass induced by the first 60 days of PGE2 treatment was maintained by another 60 and 120 days with continuous daily PGE2 treatment. When these findings were compared to those previously reported for the PTM, we found that the DTM was much more responsive to PGE2 treatment than the PTM. Percent trabecular bone area and tissue based bone formation rate increased significantly more in DTM as compared to PTM after the 60 days of 6 mg PGE2 treatment. These observations indicate that a non

  19. The effects of prostaglandin E2 in growing rats - Increased metaphyseal hard tissue and cortico-endosteal bone formation

    NASA Technical Reports Server (NTRS)

    Jee, W. S. S.; Ueno, K.; Deng, Y. P.; Woodbury, D. M.

    1985-01-01

    The role of in vivo prostaglandin E2 (PGE2) in bone formation is investigated. Twenty-five male Sprague-Dawley rats weighing between 223-267 g were injected subcutaneously with 0.3, 1.0, 3.0, and 6.0 mg of PGE2-kg daily for 21 days. The processing of the tibiae for observation is described. Radiographs and histomorphometric analyses are also utilized to study bone formation. Body weight, weights of soft tissues and bones morphometry are evaluated. It is observed that PGE2 depressed longitudinal bone growth, increased growth cartilage thickness, decreased degenerative cartilage cell size and cartilage cell production, and significantly increased proximal tibial metaphyseal hard tissue mass. The data reveal that periosteal bone formation is slowed down at higher doses of PGE2 and endosteal bone formation is slightly depressed less than 10 days post injection; however, here is a late increase (10 days after post injection) in endosteal bone formation and in the formation of trabecular bone in the marrow cavity of the tibial shaft. It is noted that the effects of PGE2 on bone formation are similar to the responses of weaning rats to PGE2.

  20. Expression of Angiotensin II Types 1 and 2 Receptors in Endometriotic Lesions.

    PubMed

    Nakao, Takehiro; Chishima, Fumihisa; Sugitani, Masahiko; Tsujimura, Ryusuke; Hayashi, Chuyu; Yamamoto, Tatsuo

    2017-01-01

    The aim of this study was to evaluate the gene and protein expression of angiotensin type (AT) 1, AT2 receptors in endometriotic lesions and its relation to prostaglandin (PG) synthases. Endometriosis samples were obtained from 32 patients with endometriotic cysts. Endometrial tissues were obtained during operations for benign gynecological conditions. The expression of the AT1 and AT2 receptor mRNA and that of PG-endoperoxide synthase 2 and microsomal PGE2 synthase-1 (mPGES-1) was examined by quantitative RT-PCR. Immunohistochemical staining was performed for these receptors. AT1 and AT2 receptor proteins were mostly located in endometrial glandular epithelium and some stromal cells. Immunoreactivity of the receptor proteins was observed in both the eutopic endometrium and endometriotic lesions. The AT1/AT2 ratio in endometriotic cysts (median 7.29, range 1.88-187.60) was significantly increased compared with that in the eutopic endometrium in the proliferative-phase in controls (median 1.01, range 0.37-2.09, p < 0.001). There was a relationship between the AT1 mRNA expression and that of mPGES-1 mRNA in the endometriotic cysts (r = 0.394089, p < 0.05). There was a significant relationship between the mRNA expression of the AT2 receptor and that of mPGES-1 in eutopic endometrium of non-endometriotic control (r = 0.610714, p < 0.05). Renin-angiotensin system may play an important role in the pathophysiology of endometriosis. © 2016 S. Karger AG, Basel.

  1. Kinetics and peptide dependency of the binding of the inhibitory NK receptor CD94/NKG2-A and the activating receptor CD94/NKG2-C to HLA-E.

    PubMed Central

    Valés-Gómez, M; Reyburn, H T; Erskine, R A; López-Botet, M; Strominger, J L

    1999-01-01

    The lytic function of human natural killer (NK) cells is markedly influenced by recognition of class I major histocompatibility complex (MHC) molecules, a process mediated by several types of activating and inhibitory receptors expressed on the NK cell. One of the most important of these mechanisms of regulation is the recognition of the non-classical class I MHC molecule HLA-E, in complex with nonamer peptides derived from the signal sequences of certain class I MHC molecules, by heterodimers of the C-type lectin-like proteins CD94 and NKG2. Using soluble, recombinant HLA-E molecules assembled with peptides derived from different leader sequences and soluble CD94/NKG2-A and CD94/NKG2-C proteins, the binding of these receptor-ligand pairs has been analysed. We show first that these interactions have very fast association and dissociation rate constants, secondly, that the inhibitory CD94/NKG2-A receptor has a higher binding affinity for HLA-E than the activating CD94/NKG2-C receptor and, finally, that recognition of HLA-E by both CD94/NKG2-A and CD94/NKG2-C is peptide dependent. There appears to be a strong, direct correlation between the binding affinity of the peptide-HLA-E complexes for the CD94/NKG2 receptors and the triggering of a response by the NK cell. These data may help to understand the balance of signals that control cytotoxicity by NK cells. PMID:10428963

  2. Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression

    PubMed Central

    Liu, Fei; Mih, Justin D.; Shea, Barry S.; Kho, Alvin T.; Sharif, Asma S.; Tager, Andrew M.

    2010-01-01

    Tissue stiffening is a hallmark of fibrotic disorders but has traditionally been regarded as an outcome of fibrosis, not a contributing factor to pathogenesis. In this study, we show that fibrosis induced by bleomycin injury in the murine lung locally increases median tissue stiffness sixfold relative to normal lung parenchyma. Across this pathophysiological stiffness range, cultured lung fibroblasts transition from a surprisingly quiescent state to progressive increases in proliferation and matrix synthesis, accompanied by coordinated decreases in matrix proteolytic gene expression. Increasing matrix stiffness strongly suppresses fibroblast expression of COX-2 (cyclooxygenase-2) and synthesis of prostaglandin E2 (PGE2), an autocrine inhibitor of fibrogenesis. Exogenous PGE2 or an agonist of the prostanoid EP2 receptor completely counteracts the proliferative and matrix synthetic effects caused by increased stiffness. Together, these results demonstrate a dominant role for normal tissue compliance, acting in part through autocrine PGE2, in maintaining fibroblast quiescence and reveal a feedback relationship between matrix stiffening, COX-2 suppression, and fibroblast activation that promotes and amplifies progressive fibrosis. PMID:20733059

  3. PGE2 suppresses intestinal T cell function in thermal injury: a cause of enhanced bacterial translocation.

    PubMed

    Choudhry, M A; Fazal, N; Namak, S Y; Haque, F; Ravindranath, T; Sayeed, M M

    2001-09-01

    Increased gut bacterial translocation in burn and trauma patients has been demonstrated in a number of previous studies, however, the mechanism for such an increased gut bacterial translocation in injured patients remains poorly understood. Utilizing a rat model of burn injury, in the present study we examined the role of intestinal immune defense by analyzing the T cell functions. We investigated if intestinal T cells dysfunction contributes to bacterial translocation after burn injury. Also our study determined if burn-mediated alterations in intestinal T cell functions are related to enhanced release of PGE2. Finally, we examined whether or not burn-related alterations in intestinal T cell function are due to inappropriate activation of signaling molecule P59fyn, which is required for T cell activation and proliferation. The results presented here showed an increase in gut bacterial accumulation in mesenteric lymph nodes after thermal injury. This was accompanied by a decrease in the intestinal T cell proliferative responses. Furthermore, the treatments of burn-injured animals with PGE2 synthesis blocker (indomethacin or NS398) prevented both the decrease in intestinal T cell proliferation and enhanced bacterial translocation. Finally, our data suggested that the inhibition of intestinal T cell proliferation could result via PGE2-mediated down-regulation of the T cell activation-signaling molecule P59fyn. These findings support a role of T cell-mediated immune defense against bacterial translocation in burn injury.

  4. Prostaglandin E2 to diagnose between reversible and irreversible pulpitis.

    PubMed

    Petrini, M; Ferrante, M; Ciavarelli, L; Brunetti, L; Vacca, M; Spoto, G

    2012-01-01

    The aim of this work is to verify a correlation between the grade of inflammation and the concentration of PGE2 in human dental pulp. A total of 25 human dental pulps were examined by histological analysis and radioimmunologic dosage of PGE2. The pulps used in this experiment were from healthy and symptomatic teeth; the first ones were collected from teeth destined to be extracted for orthodontic reasons. An increase was observed of PGE2 in reversible pulpitis compared with healthy pulps and with the irreversible pulpitis and the clear decrease of these when NSAIDs are taken. This study demonstrates that PGE2 level is correlated to histological analysis thus allowing to distinguish symptomatic teeth in reversible and irreversible pulpitis.

  5. Src kinase signaling mediates estrous behavior induced by 5β-reduced progestins, GnRH, prostaglandin E2 and vaginocervical stimulation in estrogen-primed rats.

    PubMed

    Lima-Hernández, Francisco J; Beyer, Carlos; Gómora-Arrati, Porfirio; García-Juárez, Marcos; Encarnación-Sánchez, José L; Etgen, Anne M; González-Flores, Oscar

    2012-11-01

    The progesterone receptor (PR) is a dual function protein that acts in the nucleus as a transcriptional factor and at the cytoplasm as a scaffold for the Src-MAPK signaling pathway. Several agents lacking affinity for the PR, such as 5β-reduced progestins, GnRH or prostaglandin E(2) (PGE(2)) facilitate estrous behavior in ovariectomized (ovx), estrogen-primed rats yet their action is blocked by the antiprogestin RU486. We hypothesize that these agents act by using the PR-Src-mitogen activated protein kinase alternative pathway. To test this hypothesis we used PP2, a specific inhibitor of the Src kinase family. Intraventricular infusion of 30 μg of PP2, 30 min before behavioral testing, significantly attenuated estrous behaviors induced in estradiol benzoate (E(2)B)-primed rats by 5β-dihydroprogesterone (5β-DHP), 5β-pregnan-3β-ol-20-one (5β,3β-Pgl), GnRH, PGE(2) and by manual flank/vaginocervical stimulation. These results suggest that the Src signaling system, by activating mitogen-activated protein kinases, participates in the facilitation of estrous behavior in E(2)B-primed rats induced by agents lacking affinity for the PR. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Prostaglandin E(2) synthase inhibition as a therapeutic target.

    PubMed

    Iyer, Jitesh P; Srivastava, Punit K; Dev, Rishabh; Dastidar, Sunanda G; Ray, Abhijit

    2009-07-01

    Most NSAIDs function by inhibiting biosynthesis of PGE(2) by inhibition of COX-1 and/or COX-2. Since COX-1 has a protective function in the gastro-intestinal tract (GIT), non-selective inhibition of both cycloxy genases leads to moderate to severe gastro-intestinal intolerance. Attempts to identify selective inhibitors of COX-2, led to the identification of celecoxib and rofecoxib. However, long-term use of these drugs has serious adverse effects of sudden myocardial infarction and thrombosis. Drug-mediated imbalance in the levels of prostaglandin I(2) (PGI(2)) and thromboxane A(2) (TXA(2)) with a bias towards TXA(2) may be the primary reason for these events. This resulted in the drugs being withdrawn from the market, leaving a need for an effective and safe anti-inflammatory drug. Recently, the focus of research has shifted to enzymes downstream of COX in the prosta glandin biosynthetic pathway such as prostaglandin E(2) synthases. Microsomal prostaglandin E(2) synthase-1 (mPGES-1) specifically isomerizes PGH(2) to PGE(2), under inflammatory conditions. In this review, we examine the biology of mPGES-1 and its role in disease. Progress in designing molecules that can selectively inhibit mPGES-1 is reviewed. mPGES-1 has the potential to be a target for anti-inflammatory therapy, devoid of adverse GIT and cardiac effects and warrants further investigation.

  7. The ApoE receptors Vldlr and Apoer2 in central nervous system function and disease.

    PubMed

    Lane-Donovan, Courtney; Herz, Joachim

    2017-06-01

    The LDL receptor (LDLR) family has long been studied for its role in cholesterol transport and metabolism; however, the identification of ApoE4, an LDLR ligand, as a genetic risk factor for late-onset Alzheimer's disease has focused attention on the role this receptor family plays in the CNS. Surprisingly, it was discovered that two LDLR family members, ApoE receptor 2 (Apoer2) and VLDL receptor (Vldlr), play key roles in brain development and adult synaptic plasticity, primarily by mediating Reelin signaling. This review focuses on Apoer2 and Vldlr signaling in the CNS and its role in human disease. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  8. The nuclear receptor NR2E1/TLX controls senescence.

    PubMed

    O'Loghlen, Ana; Martin, Nadine; Krusche, Benjamin; Pemberton, Helen; Alonso, Marta M; Chandler, Hollie; Brookes, Sharon; Parrinello, Simona; Peters, Gordon; Gil, Jesús

    2015-07-30

    The nuclear receptor NR2E1 (also known as TLX or tailless) controls the self-renewal of neural stem cells (NSCs) and has been implied as an oncogene which initiates brain tumors including glioblastomas. Despite NR2E1 regulating targets like p21(CIP1) or PTEN we still lack a full explanation for its role in NSC self-renewal and tumorigenesis. We know that polycomb repressive complexes also control stem cell self-renewal and tumorigenesis, but so far, no formal connection has been established between NR2E1 and PRCs. In a screen for transcription factors regulating the expression of the polycomb protein CBX7, we identified NR2E1 as one of its more prominent regulators. NR2E1 binds at the CBX7 promoter, inducing its expression. Notably CBX7 represses NR2E1 as part of a regulatory loop. Ectopic NR2E1 expression inhibits cellular senescence, extending cellular lifespan in fibroblasts via CBX7-mediated regulation of p16(INK4a) and direct repression of p21(CIP1). In addition NR2E1 expression also counteracts oncogene-induced senescence. The importance of NR2E1 to restrain senescence is highlighted through the process of knocking down its expression, which causes premature senescence in human fibroblasts and epithelial cells. We also confirmed that NR2E1 regulates CBX7 and restrains senescence in NSCs. Finally, we observed that the expression of NR2E1 directly correlates with that of CBX7 in human glioblastoma multiforme. Overall we identified control of senescence and regulation of polycomb action as two possible mechanisms that can join those so far invoked to explain the role of NR2E1 in control of NSC self-renewal and cancer.

  9. 75 FR 23710 - Order Finding That the ICE PG&E Citygate Financial Basis Contract Traded on the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... Pipe Line, LLC, serves as a juncture for 13 different pipelines. These pipelines bring in natural gas... ``hub'' refers to a juncture where two or more natural gas pipelines are connected. Hubs also serve as... analysis of PG&E Citygate natural gas prices showed that 55 percent of the observations were more than 2.5...

  10. Behaviour of Ni-PGE-Au-Cu in mafic-ultramafic volcanic suites of the 2.7 Ga Kambalda Sequence, Kalgoorlie Terrane, Yilgarn Craton

    NASA Astrophysics Data System (ADS)

    Said, Nuru; Kerrich, Robert; Maier, W. D.; McCuaig, Campbell

    2011-05-01

    The 2.7 Ga Kambalda Sequence comprises a mafic to ultramafic dominated volcanic rock sequence of the Kalgoorlie Terrane, Yilgarn Craton, Western Australia. The Sequence is divided into Lower and Upper Units separated by the Kambalda Komatiite Formation. Five basalt suites of the Lower Unit are tholeiitic where MgO spans 5-10 wt.% MgO, with minor assimilation-fractional crystallization (AFC), whereas six volcanic suites identified in the Upper Unit are tholeiitic to komatiitic-basalts with MgO 24-5 wt.% having generally greater degrees of AFC. Upper suites plot at Al 2O 3/TiO 2 (17-26) close to the primitive mantle ratio of 21, and Pt + Pd (19-31 ppb), whereas the PGE-depleted Lower basalts plot at generally lower Al 2O 3/TiO 2 (<16) and Pt + Pd (<10 ppb). Most suites have an average Pt/Pd ratio of 1.11, despite large variations in MgO contents, broadly consistent with the Pt/Pd ratio in the primitive mantle. On primitive mantle-normalised PGE plots, Upper suites generally display less fractionated patterns of the IPGE (Os, Ir, Ru and Rh) from the PPGE (Pt and Pd) relative to the Lower basalts. Most suites exhibit patterns with positive slopes reflecting relative enrichment of Pd, Pt, Au and Cu relative to Ni and IPGE. In suites of both Units, the concentrations of Ir and Ru fall with decreasing MgO contents, indicating their broadly compatible behaviour during magmatic evolution that involved AFC. Platinum and Pd behave as incompatible elements in the high-MgO suites, whereas Pt and Pd behave compatibly during crystallisation of the Lower basalt magmas, an interpretation consistent with progressively higher Cu/Pt and Cu/Pd ratios at decreasing MgO contents, and with falling Pt/Ti, collectively due to sulphur saturation induced by AFC as recorded in an antivariance of Pd/Ir with Nb/Th, a monitor of AFC. Collectively, the data suggest that several of the Lower Basalt suites crystallised under sulphide-saturated conditions, whereas most of the Upper Basalt Sequences

  11. Novel mechanisms and signaling pathways of esophageal ulcer healing: the role of prostaglandin EP2 receptors, cAMP, and pCREB

    PubMed Central

    Ahluwalia, Amrita; Baatar, Dolgor; Jones, Michael K.

    2014-01-01

    Clinical studies indicate that prostaglandins of E class (PGEs) may promote healing of tissue injury e.g., gastroduodenal and dermal ulcers. However, the precise roles of PGEs, their E-prostanoid (EP) receptors, signaling pathways including cAMP and cAMP response element-binding protein (CREB), and their relation to VEGF and angiogenesis in the tissue injury healing process remain unknown, forming the rationale for this study. Using an esophageal ulcer model in rats, we demonstrated that esophageal mucosa expresses predominantly EP2 receptors and that esophageal ulceration triggers an increase in expression of the EP2 receptor, activation of CREB (the downstream target of the cAMP signaling), and enhanced VEGF gene expression. Treatment of rats with misoprostol, a PGE1 analog capable of activating EP receptors, enhanced phosphorylation of CREB, stimulated VEGF expression and angiogenesis, and accelerated esophageal ulcer healing. In cultured human esophageal epithelial (HET-1A) cells, misoprostol increased intracellular cAMP levels (by 163-fold), induced phosphorylation of CREB, and stimulated VEGF expression. A cAMP analog (Sp-cAMP) mimicked, whereas an inhibitor of cAMP-dependent protein kinase A (Rp-cAMP) blocked, these effects of misoprostol. These results indicate that the EP2/cAMP/protein kinase A pathway mediates the stimulatory effect of PGEs on angiogenesis essential for tissue injury healing via the induction of CREB activity and VEGF expression. PMID:25059824

  12. Thymoquinone suppresses migration of LoVo human colon cancer cells by reducing prostaglandin E2 induced COX-2 activation.

    PubMed

    Hsu, Hsi-Hsien; Chen, Ming-Cheng; Day, Cecilia Hsuan; Lin, Yueh-Min; Li, Shin-Yi; Tu, Chuan-Chou; Padma, Viswanadha Vijaya; Shih, Hui-Nung; Kuo, Wei-Wen; Huang, Chih-Yang

    2017-02-21

    To identify potential anti-cancer constituents in natural extracts that inhibit cancer cell growth and migration. Our experiments used high dose thymoquinone (TQ) as an inhibitor to arrest LoVo (a human colon adenocarcinoma cell line) cancer cell growth, which was detected by cell proliferation assay and immunoblotting assay. Low dose TQ did not significantly reduce LoVo cancer cell growth. Cyclooxygenase 2 (COX-2) is an enzyme that is involved in the conversion of arachidonic acid into prostaglandin E2 (PGE2) in humans. PGE2 can promote COX-2 protein expression and tumor cell proliferation and was used as a control. Our results showed that 20 μmol/L TQ significantly reduced human LoVo colon cancer cell proliferation. TQ treatment reduced the levels of p-PI3K, p-Akt, p-GSK3β, and β-catenin and thereby inhibited the downstream COX-2 expression. Results also showed that the reduction in COX-2 expression resulted in a reduction in PGE2 levels and the suppression of EP2 and EP4 activation. Further analysis showed that TG treatment inhibited the nuclear translocation of β-catenin in LoVo cancer cells. The levels of the cofactors LEF-1 and TCF-4 were also decreased in the nucleus following TQ treatment in a dose-dependent manner. Treatment with low dose TQ inhibited the COX-2 expression at the transcriptional level and the regulation of COX-2 expression efficiently reduced LoVo cell migration. The results were further verified in vivo by confirming the effects of TQ and/or PGE2 using tumor xenografts in nude mice. TQ inhibits LoVo cancer cell growth and migration, and this result highlights the therapeutic advantage of using TQ in combination therapy against colorectal cancer.

  13. Enhanced cyclooxygenase-2 expression levels and metalloproteinase 2 and 9 activation by Hexachlorobenzene in human endometrial stromal cells.

    PubMed

    Chiappini, Florencia; Bastón, Juan Ignacio; Vaccarezza, Agustina; Singla, José Javier; Pontillo, Carolina; Miret, Noelia; Farina, Mariana; Meresman, Gabriela; Randi, Andrea

    2016-06-01

    Hexachlorobenzene (HCB) is an organochlorine pesticide that induces toxic reproductive effects in laboratory animals. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is characterized by the presence of functional endometrial tissues outside the uterine cavity. Experimental studies indicate that exposure to organochlorines can interfere with both hormonal regulation and immune function to promote endometriosis. Altered expression of metalloproteinases (MMPs) in patients with endometriosis, suggests that MMPs may play a critical role. In the endometriotic lesions, prostaglandin E2 (PGE2) produced by cyclooxygenase-2 (COX-2), binds to its EP4 receptor (EP4), and via c-Src kinase induces MMPs activation, promoting endometriosis. We examined the HCB action on MMP-2 and MMP-9 activities and expression, COX-2 levels, PGE2 signaling, and the AhR involvement in HCB-induced effects. We have used different in vitro models: (1) human endometrial stromal cell line T-HESC, (2) primary cultures of Human Uterine Fibroblast (HUF), and (3) primary cultures of endometrial stromal cells from eutopic endometrium of control (CESC) and subjects with endometriosis (EESC). Our results show that HCB enhances MMP-2 and MMP-9 activities in T-HESC, HUF and ESC cells. The MMP-9 levels were elevated in all models, while the MMP-2 expression only increased in ESC cells. HCB enhanced COX-2 and EP4 expression, PGE2 secretion and the c-Src kinase activation in T-HESC. Besides, we observed that AhR is implicated in these HCB-induced effects. In conclusion, our results show that HCB exposure could contribute to endometriosis development, affecting inflammation and invasion parameters of human endometrial cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Evaluation of PGE Liberation and Chromium Isolation in a Solid UG2 Chromitite Concentrates at Moderate Temperatures Using ICP-OES

    NASA Astrophysics Data System (ADS)

    Chiweshe, Trevor T.; Purcell, Walter; Venter, Johan A.

    2016-06-01

    Complete sample digestion is a prerequisite in achieving accurate and reproducible results in wet chemical analysis as well as effective element recovery in hydrometallurgical beneficiation processes. Inductively coupled plasma-optical emission spectroscopy was used to evaluate the efficiency of (NH4)2HPO4/(NH4)H2PO4, Na2HPO4/NaH2PO4·H2O (800°C), NH4F·HF flux (250°C), microwave dissolution using HCl and aqua regia acids (240°C) to dissolve and liberate the platinum group metals (PGE) in a Upper Group 2 (UG2) chromitite concentrate sample. Complete digestion of the UG2 chromitite ore was achieved using Na2HPO4/NaH2PO4·H2O and (NH4)2HPO4/(NH4)H2PO4 flux mixtures and average PGE (Ru, Os and Pt) yields of 1.90 g/kg (Ru), 0.88 g/kg (Os), 2.52 g/kg (Pt) were obtained using Sc as internal standard. Fusion with NH4F·HF yielded 0.85 g/kg (Ru), 0.72 g/kg (Os) and 0.95 g/kg (Pt) whilst microwave dissolution using HCl and aqua regia yielded an average of 0.77 g/kg (Ru), 0.08 g/kg (Os) and 0.35 g/kg (Pt). Sodium phosphate flux, however, introduced Na+ ions as easily ionised elements, which affected the emission intensities to yield slightly inflated PGE (Ru, Os and Pt) yields. The use of ammonium phosphate and sodium phosphate at 800°C (after the selective removal of Na+ ions) proved to better the fluxes and produced higher and consistent PGE yields. The use of ammonium phosphate flux was also shown to facilitate the isolation of a green chromium precipitate with a 98.9% purity, which may assist in a hydrometallurgical beneficiation process of the UG2 chromitite concentrate ore and may also have important implications for the ferro-chrome industry.

  15. Prostaglandin E2 Prevents Bone Loss and Adds Extra Bone to Immobilized Distal Femoral Metaphysis in Female Rats

    NASA Technical Reports Server (NTRS)

    Akamine, T.; Jee, W. S. S.; Ke, H. Z.; Li, X. J.; Lin, B. Y.

    1992-01-01

    The object of this study was to determine whether prostaglandin E2 (PGE2) can prevent disuse (underloading)-induced cancellous bone loss. Thirteen-month-old retired female Sprague-Dawley breeders served as controls or were subjected to right hindlimb immobilization by bandaging and simultaneously treated subcutaneously daily with 0, 1, 3, or 6 mg PGE2/kg/d for two and six weeks. Histomorphometric analyses were performed on the cancellous bone using double-fluorescent labeled, 20 micron thick, undecalcified distal femoral metaphysis sections. We found that PGE2 administration not only prevented disuse-induced bone loss, but also added extra bone to disuse cancellous bone in a dose-response manner. PGE2 prevented the disuse-induced osteopenia by stimulating more bone formation than and shortening the period of bone remodeling. It activated woven bone formation, stimulated lamellar bone formation, and increased the eroded bone surface above that caused by disuse alone. While underloading increased the remodeling period (sigma), PGE2 treatment of underloaded bone shortened the time for osteoclastic bone resorption and bone remodeling, and thus reduced the remodeling space. The study shows that PGE2 is a powerful anabolic agent that prevents disuse-induced osteopenia and adds extra bone to these same bones.

  16. Re-establishment of gap junctional intercellular communication (GJIC) between human endometrial carcinomas by prostaglandin E(2).

    PubMed

    Schlemmer, Scott R; Kaufman, David G

    2012-12-01

    Reduced intercellular communication via gap junctions is correlated with carcinogenesis. Gap junctional intercellular communication (GJIC), between normal human endometrial epithelial cells is enhanced when endometrial stromal cells were present in culture. This enhancement of GJIC between normal epithelial cells also occurs when they are cultured in medium conditioned by stromal cells. This observation indicated that a soluble compound (or compounds) produced and secreted by stromal cells mediates GJIC in epithelial cells. Previous studies have shown that endometrial stromal cells release prostaglandin E(2) (PGE(2)) and prostaglandin F(2α) (PGF(2α)) under physiological conditions. When we evaluated the response of normal endometrial epithelial cells to various concentrations of PGE(2,) we found enhanced GJIC with 1nM PGE(2). This is a smaller increase in GJIC than that induced by medium conditioned by stromal cells. When the extracellular concentration of PGE(2) was measured after incubation with stromal cells, it was found to be similar to the concentrations showing maximal GJIC between the normal epithelial cells. When indomethacin was used to inhibit prostaglandin synthesis by stromal cells, GJIC was reduced but not eliminated between normal endometrial epithelial cells. These observations suggest that although PGE(2) secreted by stromal cells is an important mediator of GJIC between the epithelial cells, it is not the sole mediator. Transformed endometrial epithelial cells did not demonstrate GJIC even in the presence of stromal cells. However, we were able to re-establish GJIC in transformed epithelial cells when we added PGE(2) to the cells. Our findings show that PGE(2) may serve as an intercellular mediator between stromal and epithelial cells that regulates GJIC in normal and malignant epithelial cells. This suggests that maintenance of GJIC by preserving or replacing PGE(2) secretion by endometrial stromal cells may have the potential to suppress

  17. Discovery of (1R,2S)-2-{[(2,4-Dimethylpyrimidin-5-yl)oxy]methyl}-2-(3-fluorophenyl)-N-(5-fluoropyridin-2-yl)cyclopropanecarboxamide (E2006): A Potent and Efficacious Oral Orexin Receptor Antagonist.

    PubMed

    Yoshida, Yu; Naoe, Yoshimitsu; Terauchi, Taro; Ozaki, Fumihiro; Doko, Takashi; Takemura, Ayumi; Tanaka, Toshiaki; Sorimachi, Keiichi; Beuckmann, Carsten T; Suzuki, Michiyuki; Ueno, Takashi; Ozaki, Shunsuke; Yonaga, Masahiro

    2015-06-11

    The orexin/hypocretin receptors are a family of G protein-coupled receptors and consist of orexin-1 (OX1) and orexin-2 (OX2) receptor subtypes. Orexin receptors are expressed throughout the central nervous system and are involved in the regulation of the sleep/wake cycle. Because modulation of these receptors constitutes a promising target for novel treatments of disorders associated with the control of sleep and wakefulness, such as insomnia, the development of orexin receptor antagonists has emerged as an important focus in drug discovery research. Here, we report the design, synthesis, characterization, and structure-activity relationships (SARs) of novel orexin receptor antagonists. Various modifications made to the core structure of a previously developed compound (-)-5, the lead molecule, resulted in compounds with improved chemical and pharmacological profiles. The investigation afforded a potential therapeutic agent, (1R,2S)-2-{[(2,4-dimethylpyrimidin-5-yl)oxy]methyl}-2-(3-fluorophenyl)-N-(5-fluoropyridin-2-yl)cyclopropanecarboxamide (E2006), an orally active, potent orexin antagonist. The efficacy was demonstrated in mice in an in vivo study by using sleep parameter measurements.

  18. In vitro effects of prostaglandin E2 on leucocytes from sticklebacks (Gasterosteus aculeatus) infected and not infected with the cestode Schistocephalus solidus.

    PubMed

    Kutyrev, Ivan A; Franke, Frederik; Büscher, Janine; Kurtz, Joachim; Scharsack, Jörn P

    2014-12-01

    Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations (granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of ROS decreased significantly with high (0.1 μmol L(-1)) PGE2 concentrations. In long-term (96 h) cultures high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L(-1)) and intermediate (0.1 nmol L(-1)) concentrations of PGE2 caused elevated leucocyte viability compared to controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2 concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an immunomodulator in tapeworm-fish parasite-host interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Prostaglandin E2: from clinical applications to its potential role in bone- muscle crosstalk and myogenic differentiation.

    PubMed

    Mo, Chenglin; Romero-Suarez, Sandra; Bonewald, Lynda; Johnson, Mark; Brotto, Marco

    2012-12-01

    Prostaglandin E(2) (PGE(2)), a prostanoid synthesized from arachidonic acid via the cyclooxygenase pathway, is a modulator of physiological responses including inflammation, fever, and muscle regeneration. Several patents have been filed that are related to PGE(2), one of them being directly related to skeletal muscles. In this report, we first summarize the key patents describing inventions for the utilization of PGE(2) for either diagnostic or therapeutic purposes, including skeletal muscle. In the second part of our work we present new and exciting data that demonstrates that PGE(2) accelerates skeletal muscle myogenic differentiation. Our discovery resulted from our recent and novel concept of bone-muscle crosstalk. Bone and muscle are anatomically intimate endocrine organs and we aimed to determine whether this anatomical intimacy also translates into a biochemical communication from bone cells to muscle cells at the in vitro level. The effects of MLOY4 osteocyte-like cell conditioned medium (CM) and three osteocyte-secreted factors, PGE(2), sclerostin and monocyte chemotactic protein (MCP-3), on C2C12 myogenic differentiation were evaluated using morphological analyses, a customized 96-gene PCR array, and measurements of intracellular calcium levels. MLO-Y4 CM and PGE(2), but not sclerostin and MCP-3, induced acceleration of myogenesis of C2C12 myoblasts that was linked with significant modifications in intracellular calcium homeostasis. This finding should further stimulate the pursuit of new patents to explore the use of PGE(2) and the new concept of bone-muscle crosstalk for the development and application of inventions designed to treat muscle diseases characterized by enhanced muscle wasting, such as sarcopenia.

  20. 159. Credit PG&E. Using mules and horses to transport generator ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    159. Credit PG&E. Using mules and horses to transport generator base plate from Anderson, CA, to Northern California's Kilarc powerhouse, c. 1903. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  1. Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, Yuan, E-mail: yuan.xu@ki.se; Cardell, Lars-Olaf

    Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin-more » (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance

  2. Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and {beta}-adrenergic receptor signaling pathways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.

    Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor ({alpha}7 nAChR) and {beta}-adrenergic receptors. Treatment of cells with {alpha}-bungarotoxin ({alpha}-BTX, {alpha}7nAChR antagonist) or propranolol ({beta}-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE{sub 2} and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE{sub 2} induction canmore » only be suppressed by propranolol, but not {alpha}-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.« less

  3. Structural modelling and phylogenetic analyses of PgeIF4A2 (Eukaryotic translation initiation factor) from Pennisetum glaucum reveal signature motifs with a role in stress tolerance and development

    PubMed Central

    Agarwal, Aakrati; Mudgil, Yashwanti; Pandey, Saurabh; Fartyal, Dhirendra; Reddy, Malireddy K

    2016-01-01

    Eukaryotic translation initiation factor 4A (eIF4A) is an indispensable component of the translation machinery and also play a role in developmental processes and stress alleviation in plants and animals. Different eIF4A isoforms are present in the cytosol of the cell, namely, eIF4A1, eIF4A2, and eIF4A3 and their expression is tightly regulated in cap-dependent translation. We revealed the structural model of PgeIF4A2 protein using the crystal structure of Homo sapiens eIF4A3 (PDB ID: 2J0S) as template by Modeller 9.12. The resultant PgeIF4A2 model structure was refined by PROCHECK, ProSA, Verify3D and RMSD that showed the model structure is reliable with 77 % amino acid sequence identity with template. Investigation revealed two conserved signatures for ATP-dependent RNA Helicase DEAD-box conserved site (VLDEADEML) and RNA helicase DEAD-box type, Q-motif in sheet-turn-helix and α-helical region respectively. All these conserved motifs are responsible for response during developmental stages and stress tolerance in plants. PMID:28358146

  4. Structural modelling and phylogenetic analyses of PgeIF4A2 (Eukaryotic translation initiation factor) from Pennisetum glaucum reveal signature motifs with a role in stress tolerance and development.

    PubMed

    Agarwal, Aakrati; Mudgil, Yashwanti; Pandey, Saurabh; Fartyal, Dhirendra; Reddy, Malireddy K

    2016-01-01

    Eukaryotic translation initiation factor 4A (eIF4A) is an indispensable component of the translation machinery and also play a role in developmental processes and stress alleviation in plants and animals. Different eIF4A isoforms are present in the cytosol of the cell, namely, eIF4A1, eIF4A2, and eIF4A3 and their expression is tightly regulated in cap-dependent translation. We revealed the structural model of PgeIF4A2 protein using the crystal structure of Homo sapiens eIF4A3 (PDB ID: 2J0S) as template by Modeller 9.12. The resultant PgeIF4A2 model structure was refined by PROCHECK, ProSA, Verify3D and RMSD that showed the model structure is reliable with 77 % amino acid sequence identity with template. Investigation revealed two conserved signatures for ATP-dependent RNA Helicase DEAD-box conserved site (VLDEADEML) and RNA helicase DEAD-box type, Q-motif in sheet-turn-helix and α-helical region respectively. All these conserved motifs are responsible for response during developmental stages and stress tolerance in plants.

  5. Cyclooxygenase-2 up-regulates CCR7 expression via AKT-mediated phosphorylation and activation of Sp1 in breast cancer cells.

    PubMed

    Chuang, Chun-Wei; Pan, Mei-Ren; Hou, Ming-Feng; Hung, Wen-Chun

    2013-02-01

    Up-regulation of cyclooxygenase-2 (COX-2) is frequently found in human cancers and is significantly associated with tumor metastasis. Our previous results demonstrate that COX-2 and its metabolite prostaglandin E2 (PGE2) stimulate the expression of CCR7 chemokine receptor via EP2/EP4 receptors to promote lymphatic invasion in breast cancer cells. In this study, we address the underlying mechanism of COX-2/PGE2-induced CCR7 expression. We find that COX-2/PGE2 increase CCR7 expression via the AKT signaling pathway in breast cancer cells. Promoter deletion and mutation assays identify the Sp1 site located at the -60/-57 region of CCR7 gene promoter is critical for stimulation. Chromatin immunoprecipitation (ChIP) assay confirms that in vivo binding of Sp1 to human CCR7 promoter is increased by COX-2 and PGE2. Knockdown of Sp1 by shRNA reduces the induction of CCR7 by PGE2. We demonstrate for the first time that AKT may directly phosphorylate Sp1 at S42, T679, and S698. Phosphorylation-mimic Sp1 protein harboring S42D, T679D, and S698D mutation strongly activates CCR7 expression. In contrast, change of these three residues to alanine completely blocks the induction of CCR7 by PGE2. Pathological investigation demonstrates that CCR7 expression is strongly associated with phospho-AKT and Sp1 in 120 breast cancer tissues. Collectively, our results demonstrate that COX-2 up-regulates CCR7 expression via AKT-mediated phosphorylation and activation of Sp1 and this pathway is highly activated in metastatic breast cancer. Copyright © 2012 Wiley Periodicals, Inc.

  6. Inhibition of the biosynthesis of prostaglandin E2 by low dose aspirin: implications for adenocarcinoma metastasis

    PubMed Central

    Boutaud, Olivier; Sosa, I. Romina; Amin, Taneem; Oram, Denise; Adler, David; Hwang, Hyun S.; Crews, Brenda C.; Milne, Ginger; Harris, Bradford K.; Hoeksema, Megan; Knollmann, Bjorn C.; Lammers, Philip E.; Marnett, Lawrence J.; Massion, Pierre P.; Oates, John A.

    2016-01-01

    Meta-analyses have demonstrated that low dose aspirin reduces the risk of developing adenocarcinoma metastasis, and when colon cancer is detected during aspirin treatment, there is a remarkable 83% reduction in risk of metastasis. As platelets participate in the metastatic process, the anti-platelet action of low dose aspirin likely contributes to its anti-metastatic effect. Cycloxooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) also contributes to metastasis, and we addressed the hypothesis that low dose aspirin also inhibits PGE2 biosynthesis. We show that low dose aspirin inhibits systemic PGE2 biosynthesis by 45% in healthy volunteers (p <0.0001). Aspirin is found to be more potent in colon adenocarcinoma cells than in the platelet, and in lung adenocarcinoma cells its inhibition is equivalent to that in the platelet. Inhibition of COX by aspirin in colon cancer cells is in the context of the metastasis of colon cancer primarily to the liver, the organ exposed to the same high concentrations of aspirin as the platelet. We find that the interaction of activated platelets with lung adenocarcinoma cells up-regulates COX-2 expression and PGE2 biosynthesis, and inhibition of platelet COX-1 by aspirin inhibits PGE2 production by the platelet-tumor cell aggregates. In conclusion, low dose aspirin has a significant effect on extraplatelet cyclooxygenase, and potently inhibits COX-2 in lung and colon adenocarcinoma cells. This supports a hypothesis that the remarkable prevention of metastasis from adenocarcinomas, and particularly from colon adenocarcinomas, by low dose aspirin results from its effect on platelet COX-1 combined with inhibition of PGE2 biosynthesis in metastasizing tumor cells. PMID:27554763

  7. Prostaglandin E2 releases ovine fetal ACTH from a site not perfused by the carotid vasculature.

    PubMed

    Cudd, T A; Wood, C E

    1992-07-01

    Placental prostaglandin E2 (PGE2) is thought to influence the ovine fetal adrenocortical system to control the timing of parturition. We investigated whether physiological infusions of PGE2 increase fetal immunoreactive adrenocorticotropin (iACTH) at the fetal brain or pituitary or at a site not perfused by the carotid vasculature. PGE2 was infused into the carotid artery (ica) at 0 (n = 5), 10 (n = 5), or 100 ng/min (n = 4) or into the vena cava (ivc) at 10 (n = 5) or 100 ng/min (n = 5) for 30 min in fetuses between 119 and 130 days gestation. Blood gases, vasopressin, cortisol, and arterial and central venous pressure were unchanged. Heart rate increased only in the 100 ng/min ica group. iACTH increased only in the 100 ng/min ivc group from 59 +/- 26 to 180 +/- 73 pg/ml. We conclude that PGE2 infused to create physiological plasma concentrations similar to those at the end of gestation stimulates iACTH from a site other than the fetal brain or pituitary.

  8. Oligonol supplementation attenuates body temperature and the circulating levels of prostaglandin E2 and cyclooxygenase-2 after heat stress in humans.

    PubMed

    Shin, Young Oh; Lee, Jeong Beom; Song, Young Ju; Min, Young Ki; Yang, Hun Mo

    2013-04-01

    Oligonol, a phenolic production from lychee, has been reported to exhibit anti-oxidative and anti-inflammatory effects. This study investigated the effect of Oligonol supplementation on circulating levels of prostaglandin E2 (PGE2) and cyclooxygenase (COX)-2, as well as body temperature, after heat stress in 17 healthy human male volunteers (age, 21.6±2.1 years). All experiments were performed in an automated climate chamber (26.0°C±0.5°C, relative humidity 60%±3.0%, air velocity less than 1 m/sec) between 2 and 5 p.m. Subjects ingested an Oligonol (100 mg)-containing beverage or placebo beverage before half-body immersion into hot water (42°C±0.5°C for 30 min). Tympanic and skin temperatures were measured and mean body temperatures were calculated. Serum concentrations of PGE2 and COX-2 were analyzed before, immediately after, and 60 min after immersion. Oligonol intake significantly prevented elevation of tympanic (temperature difference: 0.17°C at Post, P<.05; 0.17°C at Re-60, P<.05) and mean body temperatures (temperature difference: 0.18°C at Post, P<.05; 0.15°C at Re-60, P<.05), and lowered concentrations of serum PGE2 (increased by 13.3% vs. 29.6% at Post, P<.05) and COX-2 (increased by 15.6% vs. 21.8% at Post, P<.05), compared to placebo beverage. Our result suggests that Oligonol has the potential to suppress increases in body temperature under heat stress, and this is associated with decreases in serum levels of PGE2 and COX-2.

  9. Expression of programmed cell death1 in T follicular helper cells is regulated by prostaglandin E2 secreted by HBV-infected HepG2.2.1.5 cells.

    PubMed

    Sui, Zhefeng; Shi, Ying; Gao, Zhiling; Yang, Deguang; Wang, Zhihao

    2017-06-01

    The present study aimed to investigate the distribution of T follicular helper (Tfh)-cell subsets in patients with hepatitis B virus (HBV) and determine the underlying mechanism of HBV regulation of Tfh cells. The frequency of peripheral blood Tfh subsets was analyzed using flow cytometry. The expression level of programmed cell death‑1 (PD‑1) and prostaglandin E2 (PGE2) was quantified using reverse transcription‑quantitative polymerase chain reaction and western blotting. The PGE2 level in culture supernatant was detected using enzyme‑linked immunosorbent assay. A Transwell chamber was used to co‑culture Tfh cells with HepG2 and HepG2.2.1.5. The percentage of inducible T‑cell costimulator (ICOS)+ and total Tfh cells was high at the immune activation (IA) group; however, it was reduced in the immune tolerance (IT), responders with HBsAg seroconversion (RP) and healthy control (HC) groups. The percentage of PD‑1+ Tfh cells was significantly higher in IA and IT compared with RP and HC. The ratio of PD‑1+/total Tfh cells was positively correlated with the load of HBV DNA; therefore, this ratio may act as an indicator for HBV replication. The expression level of PD‑1 in Tfh cells was higher in the HepG2.2.1.5 co‑cultured group compared with the HepG2 group, this may be due to the high PGE2 expression level in HBV‑infected HepG2.2.1.5 cells. The findings of the present study revealed an imbalanced distribution of PD‑1+ Tfh cells in patients with HBV at different immune phases. Additionally, HBV may upregulate the expression of PD‑1 in Tfh cells by promoting HepG2.2.1.5 to secret PGE2. Identifying the effect of HBV on Tfh‑cell subsets is crucial for improving immuno-based therapy for HBV.

  10. Fyn kinase-mediated phosphorylation of NMDA receptor NR2B subunit at Tyr1472 is essential for maintenance of neuropathic pain.

    PubMed

    Abe, Tetsuya; Matsumura, Shinji; Katano, Tayo; Mabuchi, Tamaki; Takagi, Kunio; Xu, Li; Yamamoto, Akitsugu; Hattori, Kotaro; Yagi, Takeshi; Watanabe, Masahiko; Nakazawa, Takanobu; Yamamoto, Tadashi; Mishina, Masayoshi; Nakai, Yoshihide; Ito, Seiji

    2005-09-01

    Despite abundant evidence implicating the importance of N-methyl-D-aspartate (NMDA) receptors in the spinal cord for pain transmission, the signal transduction coupled to NMDA receptor activation is largely unknown for the neuropathic pain state that lasts over periods of weeks. To address this, we prepared mice with neuropathic pain by transection of spinal nerve L5. Wild-type, NR2A-deficient, and NR2D-deficient mice developed neuropathic pain; in addition, phosphorylation of NR2B subunits of NMDA receptors at Tyr1472 was observed in the superficial dorsal horn of the spinal cord 1 week after nerve injury. Neuropathic pain and NR2B phosphorylation at Tyr1472 were attenuated by the NR2B-selective antagonist CP-101,606 and disappeared in mice lacking Fyn kinase, a Src-family tyrosine kinase. Concomitant with the NR2B phosphorylation, an increase in neuronal nitric oxide synthase activity was visualized in the superficial dorsal horn of neuropathic pain mice by NADPH diaphorase histochemistry. Electron microscopy showed that the phosphorylated NR2B was localized at the postsynaptic density in the spinal cord of mice with neuropathic pain. Indomethacin, an inhibitor of prostaglandin (PG) synthesis, and PGE receptor subtype EP1-selective antagonist reduced the NR2B phosphorylation in these mice. Conversely, EP1-selective agonist stimulated Fyn kinase-dependent nitric oxide formation in the spinal cord. The present study demonstrates that Tyr1472 phosphorylation of NR2B subunits by Fyn kinase may have dual roles in the retention of NMDA receptors in the postsynaptic density and in activation of nitric oxide synthase, and suggests that PGE2 is involved in the maintenance of neuropathic pain via the EP1 subtype.

  11. Partial Loss of Anabolic Effect of Prostaglandin E2 on Bone After Its Withdrawal in Rats

    NASA Technical Reports Server (NTRS)

    Ke, H. Z.; Li, X. J.; Jee, Webster S. S.

    1991-01-01

    The object of this study was to determine the fate of PGE(sub 2)-induced new bone mass after withdrawal of PGE(sub 2) administration. Seven-month-old male Sprague-Dawley rats were given subcutaneous injections of 1, 3, and 6 mg PGE(sub 2)/kg/d for 60 days and then withdrawn for 60 and 120 days. Histomorphometric analyses were performed on double fluorescent labeled undecalcified proximal tibial bone specimens. After 60 days of PGE(sub 2) treatment, a new steady state of increased trabecular bone area (+67% and +81% with 3 and 6 mg PGE(sub 2)/kg/d) from woven bone and stimulated lamellar bone formation, elevated bone turnover, and shortened remodeling periods were achieved compared to age-matched controls. In contrast, after 60 and 120 days withdrawal of PGE(sub 2), a new steady state characterized by less trabecular bone area (+40% to +60% of controls with 3 and 6 mg/kg/d doses), normal lamellar bone formation, no woven bone formation from controls, and eroded surface greater than those seen in controls and previously in 60-day PGE(sub 2) treated rats. The decrease in new bone mass after withdrawal of PGE(sub 2) was due to a further elevation of bone resorption above that induced by the PGE(sub 2) treatment and a reduction in PGE(sub 2) stimulated bone formation activities. Although there is more trabecular bone than in controls after 120 days' withdrawal of PGE(sub 2), we postulate that the skeletal adaptation to mechanical usage will eventually reduce the bone mass to control levels. Thus, it is conservative to conclude that the anabolic effect of PGE(sub 2) was dependent upon continuous daily administration of PGE(sub 2) in these older rats.

  12. Corn silk induced cyclooxygenase-2 in murine macrophages.

    PubMed

    Kim, Kyung A; Shin, Hyun-Hee; Choi, Sang Kyu; Choi, Hye-Seon

    2005-10-01

    Stimulation of murine macrophages with corn silk induced cyclooxygenase (COX)-2 with secretion of PGE2. Expression of COX-2 was inhibited by pyrolidine dithiocarbamate (PDTC), and increased DNA binding by nuclear factor kappa B (NF-kappaB), indicating that COX-2 induction proceeds also via the NF-kappaB signaling pathway. A specific inhibitor of COX-2 decreased the expression level of inducible nitric oxide synthase (iNOS) stimulated by corn silk. PGE2 elevated the expression level of iNOS, probably via EP2 and EP4 receptors on the surface of the macrophages.

  13. Magmatic ore deposits in layered intrusions - Descriptive model for reef-type PGE and contact-type Cu-Ni-PGE deposits

    USGS Publications Warehouse

    Zientek, Michael L.

    2012-01-01

    Layered, ultramafic to mafic intrusions are uncommon in the geologic record, but host magmatic ore deposits containing most of the world's economic concentrations of platinum-group elements (PGE) (figs. 1 and 2). These deposits are mined primarily for their platinum, palladium, and rhodium contents (table 1). Magmatic ore deposits are derived from accumulations of crystals of metallic oxides, or immiscible sulfide, or oxide liquids that formed during the cooling and crystallization of magma, typically with mafic to ultramafic compositions. "PGE reefs" are stratabound PGE-enriched lode mineralization in mafic to ultramafic layered intrusions. The term "reef" is derived from Australian and South African literature for this style of mineralization and used to refer to (1) the rock layer that is mineralized and has distinctive texture or mineralogy (Naldrett, 2004), or (2) the PGE-enriched sulfide mineralization that occurs within the rock layer. For example, Viljoen (1999) broadly defined the Merensky Reef as "a mineralized zone within or closely associated with an unconformity surface in the ultramafic cumulate at the base of the Merensky Cyclic Unit." In this report, we will use the term PGE reef to refer to the PGE-enriched mineralization, not the host rock layer. Within a layered igneous intrusion, reef-type mineralization is laterally persistent along strike, extending for the length of the intrusion, typically tens to hundreds of kilometers. However, the mineralized interval is thin, generally centimeters to meters thick, relative to the stratigraphic thickness of layers in an intrusion that vary from hundreds to thousands of meters. PGE-enriched sulfide mineralization is also found near the contacts or margins of layered mafic to ultramafic intrusions (Iljina and Lee, 2005). This contact-type mineralization consists of disseminated to massive concentrations of iron-copper-nickel-PGE-enriched sulfide mineral concentrations in zones that can be tens to hundreds

  14. Lipo-PGE1 suppresses collagen production in human dermal fibroblasts via the ERK/Ets-1 signaling pathway.

    PubMed

    Yang, Yoolhee; Kim, Hee Jung; Woo, Kyong-Je; Cho, Daeho; Bang, Sa Ik

    2017-01-01

    Dysregulation of collagen production contributes to various pathological processes, including tissue fibrosis as well as impaired wound healing. Lipo-prostaglandin E1 (Lipo-PGE1), a lipid microsphere-incorporated prostaglandin E1, is used as a vasodilator for the treatment of peripheral vascular diseases. Lipo-PGE1 was recently shown to enhance human dermal fibroblast (HDF) migration and in vivo wound healing. No published study has characterized the role of Lipo-PGE1 in collagen regulation in HDFs. Here, we investigated the cellular signaling mechanism by which Lipo-PGE1 regulates collagen in HDFs. Collagen production was evaluated by the Sircol collagen assay, Western blot analysis of type I collagen and real time PCR. Unexpectedly, Lipo-PGE1 decreased mRNA expression of collagen 1A1, 1A2, and 3A1. Lipo-PGE1 markedly inhibited type I collagen and total soluble collagen production. In addition, Lipo-PGE1 inhibited transforming growth factor-β-induced collagen expression via Smad2 phosphorylation. To further investigate whether extracellular signal-regulated kinase (ERK)/Ets-1 signaling, a crucial pathway in collagen regulation, is involved in Lipo-PGE1-inhibited collagen production, cells were pretreated with an ERK-specific inhibitor, PD98059, prior to the addition of Lipo-PGE1. Lipo-PGE1-inhibited collagen mRNA expression and total soluble collagen production were recovered by pretreatment with PD98059. Moreover, Lipo-PGE1 directly induced the phosphorylation of ERK. Furthermore, silencing of Ets-1 recovered Lipo-PGE1-inhibited collagen production and PD98059 blocked Lipo-PGE1-enhanced Ets-1 expression. The present study reveals an important role for Lipo-PGE1 as a negative regulator of collagen gene expression and production via ERK/Ets-1 signaling. These results suggest that Lipo-PGE1 could potentially be a therapeutic target in diseases with deregulated collagen turnover.

  15. Jak2 FERM Domain Interaction with the Erythropoietin Receptor Regulates Jak2 Kinase Activity▿

    PubMed Central

    Funakoshi-Tago, Megumi; Pelletier, Stéphane; Moritake, Hiroshi; Parganas, Evan; Ihle, James N.

    2008-01-01

    Janus kinases are essential for signal transduction by a variety of cytokine receptors and when inappropriately activated can cause hematopoietic disorders and oncogenesis. Consequently, it can be predicted that the interaction of the kinases with receptors and the events required for activation are highly controlled. In a screen to identify phosphorylation events regulating Jak2 activity in EpoR signaling, we identified a mutant (Jak2-Y613E) which has the property of being constitutively activated, as well as an inactivating mutation (Y766E). Although no evidence was obtained to indicate that either site is phosphorylated in signaling, the consequences of the Y613E mutation are similar to those observed with recently described activating mutations in Jak2 (Jak2-V617F and Jak2-L611S). However, unlike the V617F or L611S mutant, the Y613E mutant requires the presence of the receptor but not Epo stimulation for activation and downstream signaling. The properties of the Jak2-Y613E mutant suggest that under normal conditions, Jak2 that is not associated with a receptor is locked into an inactive state and receptor binding through the FERM domain relieves steric constraints, allowing the potential to be activated with receptor engagement. PMID:18160720

  16. Effects of Daily Administration of Prostaglandin E2 and Its Withdrawal on the Lumbar Vertebral Bodies in Male Rats

    NASA Technical Reports Server (NTRS)

    Ke, Hua Zhu; Jee, Webster S. S.

    1992-01-01

    The effects of daily prostaglandin E2 (PGE2) treatment (on) and PGE2 treatment followed by withdrawal (on-off) on cancellous bone in lumbar vertebral bodies were studied in 7 month-old male Sprague-Dawley rats. The first groups of rats were given daily subcutaneous injections of 0, 1, 3, and 6 mg PGE2/kg/d for 60,120, and 180 days, and the second group of rats were given PGE2 for 60 days followed by withdrawal for 60 and 120 days. Histomorphometric analyses were performed on double-fluorescent labeled undecalcified sections of fourth lumbar vertebral bodies. Systemic PGE2 treatment elevated cancerous bone mass of lumbar vertebral bodies 26-60%, above control levels within 60 days and continued treatment maintained it for another 120 days, but the excess bone was lost after the treatment was witndrawn. PGE2 treatment for 60 days increased trabecular bone area, trabecular width, and bone formation parameters, and shortened remodeling periods in a dose-response manner. These changes were sustained at the levels achieved by 60-day treatment in the rats treated for 120 and 180 days. The eroded perimeter increased at day 60 and further at day 120 and then plateaued. In the on-off treated rats, the cancenous bone area, bone formation, and resorption parameters returned to near age-related controls by 60 days after withdrawal and were maintained there after 120 days of withdrawal. Therefore, we conclude that the continuous treatment is needed in order to maintain the PGE2-induced bone gain. When these findings were compared to those previously reported for the proximal tibial metaphyses, we found that the proximal tibial spongiosa was much more responsive to PGE2 treatment than the fourth lumbar vertebral body.

  17. In search of selective P2 receptor ligands: interaction of dihydropyridine derivatives at recombinant rat P2X(2) receptors.

    PubMed

    Jacobson, K A; Kim, Y C; King, B F

    2000-07-03

    1,4-Dihydropyridines are regarded as privileged structures for drug design, i.e. they tend to bind to a wide variety of receptor sites. We have shown that upon appropriate manipulation of the substituent groups on a 1,4-dihydropyridine template, high affinity and selectivity for the A(3) subtype of adenosine receptors ('P1 receptors') may be attained. In the present study we have begun to extend this approach to P2 receptors which are activated by ATP and other nucleotides. Nicardipine, a representative dihydropyridine, used otherwise as an L-type calcium channel blocker, was shown to be an antagonist at recombinant rat P2X(2) (IC(50)=25 microM) and P2X(4) (IC(50) approximately 220 microM) receptors expressed in Xenopus oocytes. Thus, this class of compounds represents a suitable lead for enhancement of affinity through chemical synthesis. In an attempt to modify the 1,4-dihydropyridine structure with a predicted P2 receptor recognition moiety, we have replaced one of the ester groups with a negatively charged phosphonate group. Several 4-phenyl-5-phosphonato-1,4-dihydropyridine derivatives, MRS 2154 (2, 6-dimethyl), MRS 2155 (6-methyl-2-phenyl), and MRS 2156 (2-methyl-6-phenyl), were synthesized through three component condensation reactions. These derivatives were not pure antagonists of the effects of ATP at P2X(2) receptors, rather were either inactive (MRS 2156) or potentiated the effects of ATP in a concentration-dependent manner (MRS 2154 in the 0.3-10 microM range and MRS 2155 at >1 microM). Antagonism of the effects of ATP at P2X(2) receptor superimposed on the potentiation was also observed at >10 microM (MRS 2154) or 0.3-1 microM (MRS 2155). Thus, while a conventional dihydropyridine, nicardipine, was found to antagonize rat P2X(2) receptors ninefold more potently than P2X(4) receptors, the effects of novel, anionic 5-phosphonate analogues at the receptor were more complex.

  18. Partial Loss of Anabolic Effect of Prostaglandin E(sub 2) on Bone After Its Withdrawal in Rats

    NASA Technical Reports Server (NTRS)

    Ke, H. Z.; Li, X. J.; Jee, W. S. S.

    1991-01-01

    The object of this study was to determine the fate of PGE(sub 2)-induced new bone mass after withdrawal of PGE(sub 2) administration. Seven-month-old male Sprague-Dawley rats were given subcutaneous injections of 1, 3, and 6 mg PGE(sub 2),/kg/d for 60 days and then withdrawn for 60 and 120 days. Histomorphometric analyses were performed on double fluorescent labeled undecalcified proximal tibial bone specimens. After 60 days of PGE(sub 2) treatment, a new steady state of increased trabecular bone area (+67% and +81% with 3 and 6 mg PGE(sub 2)/kg/d) from woven bone and stimulated lamellar bone formation, elevated bone turnover, and shortened remodeling periods were achieved compared to age-matched controls. In contrast, after 60 and 120 days withdrawal of PGE(sub 2), a new steady state characterized by less trabecular bone area (+40% to +60% of controls with 3 and 6 mg/kg/d doses), normal lamellar bone formation, no woven bone formation from controls, and eroded surface greater than those seen in controls and previously in 60-day PGE(sub 2) treated rats. The decrease in new bone mass after withdrawal of PGE(sub 2), was due to a further elevation of bone resorption above that induced by the PGE(sub 2) treatment and a reduction in PGE(sub 2), stimulated bone formation activities. Although there is more trabecular bone than in controls after 120 days withdrawal of PGE(sub 2), we postulate that the skeletal adaptation to mechanical usage will eventually reduce the bone mass to control levels. Thus, it is conservative to conclude that the anabolic effect of PGE(sub 2) was dependent upon continuous daily administration of PGE(sub 2) in these older rats.

  19. Protection of mice against mixed fission neutron-gamma (n: gamma = 1:1) irradiation by WR-2721, 16,16-dimethyl PGE2, and the combination of both agents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Steel, L.K.; Walden, T.L. Jr.; Hughes, H.N.

    1988-09-01

    The survival of mice after whole-body exposure to a modified fission neutron-gamma field (n: gamma = 1:1) was used to examine radiation protection by WR-2721, 16,16-dimethyl PGE2(DiPGE2), and the combination of both agents. Administration of WR-2721 (453 mg/kg) increased the LD50/30 from 5.24 to 7.17 Gy (DMF = 1.37), whereas pretreatment with DiPGE2 (1.6 mg/kg) increased the LD50/30 to 5.77 Gy (dose modification factor (DMF) = 1.10). The combination of 453 mg/kg WR-2721 and 0.4 mg/kg DiPGE2 resulted in an LD50/30 of 7.33 Gy, yielding a DMF of 1.39. However, no significant difference in protection was obtained with the combinationmore » of the two agents compared to that seen with WR-2721 alone.« less

  20. Granulocyte elastase activity and PGE2 levels in gingival crevicular fluid in relation to the presence of subgingival periodontopathogens in subjects with untreated adult periodontitis.

    PubMed

    Jin, L J; Söder, P O; Leung, W K; Corbet, E F; Samaranayake, L P; Söder, B; Davies, W I

    1999-08-01

    This study aimed to determine the association between the levels of granulocyte elastase and prostaglandin E2 (PGE2) in GCE and the concomitant presence of periodontopathogens in untreated adult periodontitis (AP). GCF and subgingival plaque were sampled by paper strips and paper points respectively, from various periodontal sites in 16 AP subjects. Granulocyte elastase activity in GCF was analyzed with a low molecular weight substrate specific for granulocyte elastase, pGluProVal-pNA, and the maximal rate of elastase activity (MR-EA, mAbs/min/site) was calculated. PGE2 levels in GCF were determined by radioimmunoassay. 5 species-specific DNA probes were used to detect the presence of A. actinomyceterncomitans (A.a., ATCC 43718), B. forsythus (B.f, ATCC 43037), P. gingivalis (P.g., ATCC 33277), P. intermedia (P.i., ATCC 33563), and T. denticola (T.d., ATCC 35405), with a sensitivity of 10(3) cells/paper point. No A.a. was detectable from all sites sampled. The predominant combination of species detected was B.f., P.g., P.i. & T.d. and it was significantly higher at periodontitis sites (68%) than at healthy (7%) or gingivitis sites (29%) (p<0.05). Overall, MR-EA values were strongly correlated with PGE2 levels (r=0.655, p<0.001), especially at these periodontitis sites co-infected by B.f., P.g., P.i. & T.d. (r=0.722, p<0.001). The periodontitis sites co-infected by the 4 species were observable from 15 subjects. These sites were sub-grouped into 8 subjects with a high MR-EA and 7 subjects with a low MR-EA. The PGE2 levels in the high MR-EA group were significantly higher than in the low MR-EA group (p<0.05). No significant differences in clinical or bacterial data were found between the two groups. While within the high MR-EA group, similar results were found between the paired periodontitis sites in each subject with highest and lowest MR-EA values. This study shows that the local host response to bacterial challenge in untreated periodontal pockets is diverse in

  1. 171. Credit PG&E. Hamden Holmes Noble, founder of the Keswick ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    171. Credit PG&E. Hamden Holmes Noble, founder of the Keswick Electric Power Company. President of Keswick Power and its successor companies -- Northern California Power Company and Northern California Power Company, Consolidated (until 1915). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  2. Relaxant effect of ghrelin on guinea pig isolated tracheal smooth muscle: role of epithelial NO and PGE2.

    PubMed

    Al-Ayed, Mohammed Saeed Zayed

    2018-06-01

    This study aimed at investigating the potential ghrelin relaxing effect on guinea pig isolated tracheal smooth muscle (TSM). Using an in vitro experimental approach, the physiological role of the airway epithelium on smooth muscle relaxation has been investigated by analyzing the dose-response curves for carbachol- or histamine-induced contractions on epithelium intact versus denuded tracheal tissue. The relaxant effect of ghrelin (5-200 μmol/L) then investigated on carbachol-contracted, non-sensitized, and ovalbumin (OVA)-sensitized guinea pig TSM with an intact or denuded epithelium. The isolated TSMs from identical guinea pigs were incubated in Krebs solution aerated with 95% O 2 and 5% CO 2 through an automated tissue organ bath system (n = 6 for each group). The ghrelin relaxation mechanism was assessed by adding L-NAME, indomethacin, and YIL-781 for GHS-R1 into the tissue chamber. The spasmogens carbachol and histamine have shown a significantly higher contracting effect on epithelium-denuded than in epithelium-intact TSM confirmed by the significantly higher mean pEC50 of both agonists on the epithelium-denuded trachea (p < 0.05). Ghrelin has shown a concentration-dependent relaxing effect on carbachol-contracted TSM (r = 0.96, p = 0.00). The effect was more evident in the intact non-sensitized than in epithelium-denuded or OVA-sensitized groups (p < 0.05). Preincubation with nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) inhibitors has significantly reduced the ghrelin-induced relaxation on epithelium-intact TSM suggesting an epithelium-dependant mechanism. However, GHS-R1a antagonist has also succeeded to reduce ghrelin relaxant effect, which needs further clarification. Ghrelin proved to have a potential TSM relaxant effect possibly through epithelium-dependant mechanisms involving NO and PGE 2 .

  3. Prostaglandin E2 from Candida albicans Stimulates the Growth of Staphylococcus aureus in Mixed Biofilms

    PubMed Central

    Krause, Jan; Geginat, Gernot; Tammer, Ina

    2015-01-01

    Background Previous studies showed that Staphylococcus aureus and Candida albicans interact synergistically in dual species biofilms resulting in enhanced mortality in animal models. Methodology/Principal Findings The aim of the current study was to test possible candidate molecules which might mediate this synergistic interaction in an in vitro model of mixed biofilms, such as farnesol, tyrosol and prostaglandin (PG) E2. In mono-microbial and dual biofilms of C.albicans wild type strains PGE2 levels between 25 and 250 pg/mL were measured. Similar concentrations of purified PGE2 significantly enhanced S.aureus biofilm formation in a mode comparable to that observed in dual species biofilms. Supernatants of the null mutant deficient in PGE2 production did not stimulate the proliferation of S.aureus and the addition of the cyclooxygenase inhibitor indomethacin blocked the S.aureus biofilm formation in a dose-dependent manner. Additionally, S. aureus biofilm formation was boosted by low and inhibited by high farnesol concentrations. Supernatants of the farnesol-deficient C. albicans ATCC10231 strain significantly enhanced the biofilm formation of S. aureus but at a lower level than the farnesol producer SC5314. However, C. albicans ATCC10231 also produced PGE2 but amounts were significantly lower compared to SC5314. Conclusion/Significance In conclision, we identified C. albicans PGE2 as a key molecule stimulating the growth and biofilm formation of S. aureus in dual S. aureus/C. albicans biofilms, although C. albicans derived farnesol, but not tyrosol, may also contribute to this effect but to a lesser extent. PMID:26262843

  4. G protein-coupled estrogen receptor inhibits the P2Y receptor-mediated Ca(2+) signaling pathway in human airway epithelia.

    PubMed

    Hao, Yuan; Chow, Alison W; Yip, Wallace C; Li, Chi H; Wan, Tai F; Tong, Benjamin C; Cheung, King H; Chan, Wood Y; Chen, Yangchao; Cheng, Christopher H; Ko, Wing H

    2016-08-01

    P2Y receptor activation causes the release of inflammatory cytokines in the bronchial epithelium, whereas G protein-coupled estrogen receptor (GPER), a novel estrogen (E2) receptor, may play an anti-inflammatory role in this process. We investigated the cellular mechanisms underlying the inhibitory effect of GPER activation on the P2Y receptor-mediated Ca(2+) signaling pathway and cytokine production in airway epithelia. Expression of GPER in primary human bronchial epithelial (HBE) or 16HBE14o- cells was confirmed on both the mRNA and protein levels. Stimulation of HBE or 16HBE14o- cells with E2 or G1, a specific agonist of GPER, attenuated the nucleotide-evoked increases in [Ca(2+)]i, whereas this effect was reversed by G15, a GPER-specific antagonist. G1 inhibited the secretion of two proinflammatory cytokines, interleukin (IL)-6 and IL-8, in cells stimulated by adenosine 5'-(γ-thio)triphosphate (ATPγS). G1 stimulated a real-time increase in cAMP levels in 16HBE14o- cells, which could be inhibited by adenylyl cyclase inhibitors. The inhibitory effects of E2 or G1 on P2Y receptor-induced increases in Ca(2+) were reversed by treating the cells with a protein kinase A (PKA) inhibitor. These results demonstrated that the inhibitory effects of G1 or E2 on P2Y receptor-mediated Ca(2+) mobilization and cytokine secretion were due to GPER-mediated activation of a cAMP-dependent PKA pathway. This study has reported, for the first time, the expression and function of GPER as an anti-inflammatory component in human bronchial epithelia, which may mediate through its opposing effects on the pro-inflammatory pathway activated by the P2Y receptors in inflamed airway epithelia.

  5. A globotetraosylceramide (Gb₄) receptor-based ELISA for quantitative detection of Shiga toxin 2e.

    PubMed

    Togashi, Katsuhiro; Sasaki, Shiho; Sato, Wataru

    2015-08-01

    Currently, no simple assays are available for routine quantitative detection of Escherichia coli-produced Shiga toxin 2e (Stx2e) that causes porcine edema disease. Here, we present a novel quantitative detection method for Stx2e based on the measurement of Stx2e binding to the specific globotetraosylceramide (Gb4) receptor by ELISA (Gb4-ELISA). No cross-reactivity was found with the other Shiga toxins Stx1 and Stx2, indicating high specificity. When the recombinant Stx2e B subunit (Stx2eB) was used, the absorbance measured by Gb4-ELISA increased linearly with Stx2eB concentration in the range of 20-2,500 ng/ml. The Gb4-ELISA method can be easily performed, suggesting that it would be a useful diagnostic tool for porcine edema disease.

  6. Activation of E-prostanoid 3 receptor in macrophages facilitates cardiac healing after myocardial infarction

    PubMed Central

    Tang, Juan; Shen, Yujun; Chen, Guilin; Wan, Qiangyou; Wang, Kai; Zhang, Jian; Qin, Jing; Liu, Guizhu; Zuo, Shengkai; Tao, Bo; Yu, Yu; Wang, Junwen; Lazarus, Michael; Yu, Ying

    2017-01-01

    Two distinct monocyte (Mo)/macrophage (Mp) subsets (Ly6Clow and Ly6Chigh) orchestrate cardiac recovery process following myocardial infarction (MI). Prostaglandin (PG) E2 is involved in the Mo/Mp-mediated inflammatory response, however, the role of its receptors in Mos/Mps in cardiac healing remains to be determined. Here we show that pharmacological inhibition or gene ablation of the Ep3 receptor in mice suppresses accumulation of Ly6Clow Mos/Mps in infarcted hearts. Ep3 deletion in Mos/Mps markedly attenuates healing after MI by reducing neovascularization in peri-infarct zones. Ep3 deficiency diminishes CX3C chemokine receptor 1 (CX3CR1) expression and vascular endothelial growth factor (VEGF) secretion in Mos/Mps by suppressing TGFβ1 signalling and subsequently inhibits Ly6Clow Mos/Mps migration and angiogenesis. Targeted overexpression of Ep3 receptors in Mos/Mps improves wound healing by enhancing angiogenesis. Thus, the PGE2/Ep3 axis promotes cardiac healing after MI by activating reparative Ly6Clow Mos/Mps, indicating that Ep3 receptor activation may be a promising therapeutic target for acute MI. PMID:28256515

  7. Intravenous anesthetic propofol suppresses prostaglandin E2 production in murine dendritic cells.

    PubMed

    Inada, Takefumi; Kubo, Kozue; Ueshima, Hironobu; Shingu, Koh

    2011-01-01

    Propofol is an intravenous anesthetic that is widely used for anesthesia and sedation. Dendritic cells (DC) are one of the crucial immune cells that bridge innate and adaptive immunity, in which DC process antigens during innate immune responses to present them to naïve T-cells, leading to an establishment of adaptive immunity. Prostaglandin (PG)-E(2) may be secreted by DC into the microenvironment, considerably influencing DC phenotype and function, and thus determining the fate of adaptive immunity. Since propofol suppresses PGE(2) production in murine macrophages, the primary purpose of the present study was to determine whether propofol also suppresses PGE(2) production in DC. Assuming a positive finding of such suppression, we tested whether this also leads to alterations of interleukin (IL)-12 and IL-10 production and DC surface marker expression, both of which can be modulated by PGE(2). In bone marrow-derived DC, propofol significantly suppressed the PGE(2) production after lipopolysaccharide stimulation. Cyclo-oxygenase (COX) protein expression and arachidonic acid release were unaffected, while COX enzyme activity was significantly inhibited by propofol. The propofol-induced COX inhibition did not lead to the increased production of cysteinyl leukotrienes and leukotriene-B(4). Endogenous COX inhibition with propofol, as well as with the selective COX-2 inhibitor, NS-398, did not affect IL-12 and IL-10 production from DC. The surface expression of I-A(b) and CD40 on DC was not changed, while that of CD86 slightly increased, with both propofol and NS-398; expression of CD80 was not affected with propofol, but increased slightly with NS-398. Finally, endogenous COX inhibition with either propofol or NS-398 did not significantly affect the ability of DC to induce allogeneic T-cell proliferation. It is concluded that the intravenous anesthetic propofol suppresses COX enzyme activity in DC, with no consequences with respect to IL-12/IL-10 production and

  8. Influence of prostaglandin E2 on parturition in cattle.

    PubMed

    Hirsbrunner, G; Zanolari, P; Althaus, H; Hüsler, J; Steiner, A

    2007-09-22

    A double-blinded, randomised, placebo-controlled field study of the influence of prostaglandin E2 (PGE2) on cattle at parturition was carried out. The extent of cervical opening and the intensity of labour were scored before administration of the compound and 10 minutes later; routine birth assistance was then continued by the veterinarian. Successful birth occurred more quickly in the cows treated with PGE2. The extent of cervical opening before the administration of the drug had a significant effect on the time to delivery, but the intensity of labour and a concomitant infusion of calcium did not have significant effects on this period. The less open the cervix before administration of the drug, the more the duration of parturition differed between the two groups, with the placebo group taking longer. A telephone follow-up inquiry found no significant differences between the cows postpartum; there were cases of mastitis and hypocalcaemia in both groups. The incidence of retained fetal membranes and the mortality of the calves were higher in the placebo group, but in neither case was the difference significant.

  9. Vascular Smooth Muscle-Specific EP4 Receptor Deletion in Mice Exacerbates Angiotensin II-Induced Renal Injury.

    PubMed

    Thibodeau, Jean-Francois; Holterman, Chet E; He, Ying; Carter, Anthony; Cron, Gregory O; Boisvert, Naomi C; Abd-Elrahman, Khaled S; Hsu, Karolynn J; Ferguson, Stephen S G; Kennedy, Christopher R J

    2016-10-20

    Cyclooxygenase inhibition by non-steroidal anti-inflammatory drugs is contraindicated in hypertension, as it may reduce glomerular filtration rate (GFR) and renal blood flow. However, the identity of the specific eicosanoid and receptor underlying these effects is not known. We hypothesized that vascular smooth muscle prostaglandin E2 (PGE2) E-prostanoid 4 (EP4) receptor deletion predisposes to renal injury via unchecked vasoconstrictive actions of angiotensin II (AngII) in a hypertension model. Mice with inducible vascular smooth muscle cell (VSMC)-specific EP4 receptor deletion were generated and subjected to AngII-induced hypertension. EP4 deletion was verified by PCR of aorta and renal vessels, as well as functionally by loss of PGE2-mediated mesenteric artery relaxation. Both AngII-treated groups became similarly hypertensive, whereas albuminuria, foot process effacement, and renal hypertrophy were exacerbated in AngII-treated EP4 VSMC-/- but not in EP4 VSMC+/+ mice and were associated with glomerular scarring, tubulointerstitial injury, and reduced GFR. AngII-treated EP4 VSMC-/- mice exhibited capillary damage and reduced renal perfusion as measured by fluorescent bead microangiography and magnetic resonance imaging, respectively. NADPH oxidase 2 (Nox2) expression was significantly elevated in AngII-treated EP4 -/- mice. EP4-receptor silencing in primary VSMCs abolished PGE2 inhibition of AngII-induced Nox2 mRNA and superoxide production. These data suggest that vascular EP4 receptors buffer the actions of AngII on renal hemodynamics and oxidative injury. EP4 agonists may, therefore, protect against hypertension-associated kidney damage. Antioxid. Redox Signal. 25, 642-656.

  10. The role of protease-activated receptors PAR-1 and PAR-2 in the repair of 16HBE 14o(-) epithelial cell monolayers in vitro.

    PubMed

    Ewen, D; Clarke, S L; Smith, J R; Berger, C; Salmon, G; Trevethick, M; Shute, J K

    2010-03-01

    We recently reported that repair following mechanical wounding of epithelial cell layers in vitro is dependent on fibrin formation and the activity of locally expressed coagulation cascade proteins. Serine proteases of the coagulation cascade are an important group of protease-activated receptor (PAR) activators and PAR-1 to 4 are expressed by the normal bronchial epithelium. We tested the hypothesis that activation of PAR-1 and PAR-2 by coagulation cascade proteases stimulates epithelial repair via effects on fibrin formation. Using mechanically wounded 16HBE 14o(-) epithelial cell layers in culture, we investigated the effect of PAR-1 and PAR-2 agonist peptides, control partially scrambled peptides and PAR-neutralizing antibodies on the rate of repair and fibrin formation. Coagulation factors in culture supernatants were measured by immunoblot. RT-PCR was used to investigate PAR-1, PAR-2 and PGE2 receptor (EP-1 to EP-4) expression in this model and qRT-PCR to quantify responses to wounding. Additionally, we investigated the effect of exogenously added factor Xa (FXa) and neutrophil elastase and the influence of PGE2 and indomethacin on the repair response. PAR-1 and PAR-2 peptide agonists stimulated the rate of repair and enhanced the formation of a fibrin provisional matrix to support the repair process. Conversely, PAR-neutralizing antibodies inhibited repair. Under serum-free culture conditions, 16HBE 14o(-) cells expressed EP-2 and EP-3, but not EP-1 or EP-4, receptors. Wounding induced an increased expression of EP-3 but did not alter EP-2, PAR-1 or PAR-2 expression. In the absence of PAR agonists, there was no evidence for a role for PGE2 in fibrin formation or the repair process. Indomethacin attenuated fibrin formation in wounded cultures only in the presence of the PAR-2 peptide. FXa stimulated epithelial repair while neutrophil elastase reduced the levels of coagulation factors and inhibited repair. Locally expressed serine proteases of the coagulation

  11. Interleukin-6 as an endogenous pyrogen: induction of prostaglandin E2 in brain but not in peripheral blood mononuclear cells.

    PubMed

    Dinarello, C A; Cannon, J G; Mancilla, J; Bishai, I; Lees, J; Coceani, F

    1991-10-25

    Fever induced by endogenous as well as exogenous pyrogens is often prevented by cyclooxygenase inhibitors; endogenous pyrogens stimulate prostaglandin E2 (PGE2) in or near the thermoregulatory centers of the brain. The cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF), are two pyrogens which stimulate brain PGE2 formation during fever and also increase PGE2 synthesis in human mononuclear cells in vitro. In the present study, we examined whether interleukin-6 (IL-6) stimulates PGE2 formation in a manner similar to IL-1 and TNF. Both glycosylated and non-glycosylated forms of recombinant human IL-6 were tested. Following intravenous injection into rabbits, the glycosylated IL-6 was more pyrogenic than the non-glycosylated form and there was no evidence of synergy in the production of fever when IL-6 and IL-1 were given simultaneously. IL-6 fever was blocked by prior administration of the cyclooxygenase inhibitor ibuprofen. IL-6 was also pyrogenic in the cat by either the systemic or the intraventricular route. However, in both species, IL-6 was less effective than IL-1 beta. When given intraventricularly to cats, IL-6 produced an increase in PGE2 levels of the cerebrospinal fluid in parallel with the rise in body temperature. In the latter respect, IL-6 imitated IL-1 beta; however, IL-6 from 0.15-15 micrograms/ml did not increase mononuclear cell PGE2 production in vitro whereas IL-1 beta induced 20-30-fold increases in PGE2 at 100 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Central pathway for spontaneous and prostaglandin E2-evoked cutaneous vasoconstriction.

    PubMed

    Rathner, Joseph A; Madden, Christopher J; Morrison, Shaun F

    2008-07-01

    A reduction of heat loss to the environment through increased cutaneous vasoconstrictor (CVC) sympathetic outflow contributes to elevated body temperature during fever. We determined the role of neurons in the dorsomedial hypothalamus (DMH) in increases in CVC sympathetic tone evoked by PGE2 into the preoptic area (POA) in chloralose/urethane-anesthetized rats. The frequency of axonal action potentials of CVC sympathetic ganglion cells recorded from the surface of the tail artery was increased by 1.8 Hz following nanoinjections of bicuculline (50 pmol) into the DMH. PGE2 nanoinjection into the POA elicited a similar excitation of tail CVC neurons (+2.1 Hz). Subsequent to PGE2 into the POA, muscimol (400 pmol/side) into the DMH did not alter the activity of tail CVC neurons. Inhibition of neurons in the rostral raphé pallidus (rRPa) eliminated the spontaneous discharge of tail CVC neurons but only reduced the PGE2-evoked activity. Residual activity was abolished by subsequent muscimol into the rostral ventrolateral medulla. Transections through the neuraxis caudal to the POA increased the activity of tail CVC neurons, which were sustained through transections caudal to DMH. We conclude that while activation of neurons in the DMH is sufficient to activate tail CVC neurons, it is not necessary for their PGE2-evoked activity. These results support a CVC component of increased core temperature elicited by PGE2 in POA that arises from relief of a tonic inhibition from neurons in POA of CVC sympathetic premotor neurons in rRPa and is dependent on the excitation of CVC premotor neurons from a site caudal to DMH.

  13. Effect of inhibition of prostaglandin E2 production on pancreatic infection in experimental acute pancreatitis

    PubMed Central

    Coelho, Ana Maria M.; Sampietre, Sandra; Patzina, Rosely; Jukemura, Jose; Cunha, Jose Eduardo M.; Machado, Marcel C.C.

    2007-01-01

    Objective. Acute pancreatitis is one the important causes of systemic inflammatory response syndrome (SIRS). SIRS results in gut barrier dysfunction that allows bacterial translocation and pancreatic infection to occur. Indomethacin has been used to reduce inflammatory process and bacterial translocation in experimental models. The purpose of this study was to determine the effect of inhibition of prostaglandin E2 (PGE2) production on pancreatic infection. Materials and methods. An experimental model of severe acute pancreatitis (AP) was utilized. The animals were divided into three groups: sham (surgical procedure without AP induction); pancreatitis (AP induction); and indomethacin (AP induction plus administration of 3 mg/kg of indomethacin). Serum levels of interleukin (IL)-6 and IL-10, PGE2, and tumor necrosis factor (TNF)-α were measured 2 h after the induction of AP. We analyzed the occurrence of pancreatic infection with bacterial cultures performed 24 h after the induction of AP. The occurrence of pancreatic infection (considered positive when the CFU/g was >105), pancreatic histologic analysis, and mortality rate were studied. Results. In spite of the reduction of IL-6, IL-10, and PGE2 levels in the indomethacin group, TNF-α level, bacterial translocation, and pancreatic infection were not influenced by administration of indomethacin. The inhibition of PGE2 production did not reduce pancreatic infection, histologic score, or mortality rate. Conclusion. The inhibition of PGE2 production was not able to reduce the occurrence of pancreatic infection and does not have any beneficial effect in this experimental model. Further investigations will be necessary to discover a specific inhibitor that would make it possible to develop an anti-inflammatory therapy. PMID:18345325

  14. [Cervix ripening using drugs before oxytocin labor induction. Clinical study of a new prostaglandin E2 triacetin gel].

    PubMed

    Zahradnik, H P; Quaas, L; Kröner-Fehmel, E E; Kieback, D G; Lippert, T H

    1987-03-01

    In an open randomized clinical study, 50 of 100 gravidae with a low Bishop score (less than or equal to 5) at term were treated with prostaglandin E2 (0.5 mg PGE2 in 2.5 ml Triacetin gel. Prepidil, intracervically) 12 hours before the indicated i.v. oxytocin induction. In 50 patients labor was induced intravenously without any pretreatment. In 46 of 50 pretreated women (92%) there was an increase in the Bishop score of at least three points, and of only two points in the remaining four. In the control group no significant increase in the Bishop score was measurable. Sixteen patients delivered within the first 12 hours after PGE2 gel administration, before oxytocin induction. Three women in the untreated control group also delivered during this pre-observation period. In 14 (64%) of 22 women in whom cervical priming with PGE2 was performed and 26 (57%) of 47 patients in whom it was not the first intravenous oxytocin induction was successful. The frequency of cesarean sections was 10% (n = 5) in the PGE2 gel group and 12% (n = 6) in the oxytocin group. The oxytocin dose needed to induce labor was significantly lower after cervical priming. No severe side effects were observed during and after PGE2 treatment, in either the mothers or the children.

  15. Prostaglandin E2 Levels of Aqueous and Vitreous Humor in Ketorolac 0.4% and Nepafenac 0.1% Administered Healthy Rabbits.

    PubMed

    Acar, Ugur; Acar, Damla Erginturk; Tanriverdi, Cafer; Acar, Mutlu; Ozdemir, Ozdemir; Erikci, Acelya; Ornek, Firdevs

    2017-06-01

    To compare the lowering effects of ketorolac 0.4% and nepafenac 0.1% on aqueous and vitreous humor prostaglandin E 2 (PGE 2 ) levels in rabbits. Ketorolac and nepafenac ophthalmic solutions were administered to the right eyes of 24 healthy rabbits after randomized division into two groups. The left eyes of these rabbits were considered as controls for the two groups. On the 4th day of the experiment, the samples were taken from the aqueous and vitreous humors of the rabbits bilaterally, and PGE 2 levels were measured by an enzyme immune assay kit. Ketorolac and nepafenac achieved a statistically significant decrease (p<0.001, for each) in PGE 2 levels in the aqueous (11.75 ± 6.15 and 14.75 ± 7.60 pg/mL, respectively) and the vitreous humor (6.58 ± 4.62 and 9.83 ± 4.55 pg/mL, respectively). Both ketorolac and nepafenac inhibited PGE 2 levels in both the aqueous and vitreous humors of rabbits. Although PGE 2 -lowering effects were similar in the aqueous humor, nepafenac seemed to be more potent than ketorolac in the vitreous humor.

  16. Prostaglandin E2 inhibition of IL-27 production in murine dendritic cells: a novel mechanism which involves IRF1

    PubMed Central

    Hooper, Kirsten M; Yen, Jui-Hung; Kong, Weimin; Rahbari, Kate M; Kuo, Ping-Chang; Gamero, Ana M; Ganea, Doina

    2016-01-01

    IL-27, a multifunctional cytokine produced by antigen-presenting cells, antagonizes inflammation by affecting conventional dendritic cells (cDC), inducing IL-10, and promoting development of regulatory Tr1 cells. Although the mechanisms involved in IL-27 induction are well-studied, much less is known about the factors that negatively impact IL-27 expression. Prostaglandin E2 (PGE2), a major immunomodulatory prostanoid, acts as a pro-inflammatory agent in several models of inflammatory/autoimmune diseases, promoting primarily Th17 development and function. In this study, we report on a novel mechanism which promotes the pro-inflammatory function of PGE2. We showed previously that PGE2 inhibits IL-27 production in murine bone marrow derived DCs. Here, we show that, in addition to BMDCs, PGE2 inhibits IL-27 production in macrophages and in splenic cDC and we identify a novel pathway consisting of signaling through EP2/EP4→induction of cAMP→downregulation of IRF1 expression and binding to the p28 ISRE site. The inhibitory effect of PGE2 on p28 and irf1 expression does not involve endogenous IFNβ, STAT1 or STAT2, and inhibition of IL-27 does not appear to be mediated through PKA, EPAC, PI3K, or MAPKs. We observed similar inhibition of il27p28 expression in vivo in splenic DC following administration of dimethyl PGE2 in conjunction with LPS. Based on the anti-inflammatory role of IL-27 in cDC and through the generation of Tr1 cells, we propose that the PGE2-induced inhibition of IL-27 in activated cDC represents an important additional mechanism for its in vivo pro-inflammatory functions. PMID:28062696

  17. THE INVESTIGATION OF EFFECT OF FLURBIPROFEN AXETIL ON THE TISSUE GROWTH AND THE CONTENT OF PGE2 IN CERVICAL CANCER.

    PubMed

    Lu, Jing; Wang, Shenggang; Chen, Guiying; Sun, Xiaofeng; Li, Kezhong

    2016-11-01

    The aim of this study was to investigate whether flurbiprofen axetil can inhibit the tissue growth and the content of PGE2 in cervical cancer or not. Fifty female BALB/c nude mice were randomly divided into control group (C), tumor + saline group (T), tumor + flurbiprofen axetil 10 mg/kg (Cfl0) group, tumor + flurbiprofen axetil 25 mg/kg (Cf25) group, tumor + flurbiprofen axetil tumor 50 mg/kg (Cf50), so that each group had 10 animals. Then, the animal model of human cervical carcinoma was established, and the relative tumor volume (RTV), relative tumor proliferation rate (T/C) and tumor inhibition rate were measured. The content of PGE2 in tumor tissue was determined by using enzyme-linked immunosorbent assay. There was no tumor formation in group C, and the time of tumor growth in other groups was non-statistically different. The RVT in Cf50 group was lower than in other groups. It was evident from the curve of tumor growth that the tumor weight in T group was evidently higher than that of administration groups (p < 0.01). The tumor inhibition rates of Cf10, Cf25 and Cf50 groups were 16.8, 19.6 and 36%, respectively, and the relative tumor proliferation rate were 85, 91 and 72%, respectively. The PGE, level of Cf50 was statistically (p < 0.01) lower than that of Cfl0 and Cf25 groups. Flurbiprofen axetil can inhibit the growth of cervical cancer transplanted tumor in nude mice and this inhibitory effect was maximal in Cf50 group. Flurbiprofen axetil can inhibit the production of PGE2 in tumor tissue of cervical carcinoma in nude mice.

  18. The heterodimeric assembly of the CD94-NKG2 receptor family and implications for human leukocyte antigen-E recognition.

    PubMed

    Sullivan, Lucy C; Clements, Craig S; Beddoe, Travis; Johnson, Darryl; Hoare, Hilary L; Lin, Jie; Huyton, Trevor; Hopkins, Emma J; Reid, Hugh H; Wilce, Matthew C J; Kabat, Juraj; Borrego, Francisco; Coligan, John E; Rossjohn, Jamie; Brooks, Andrew G

    2007-12-01

    The CD94-NKG2 receptor family that regulates NK and T cells is unique among the lectin-like receptors encoded within the natural killer cell complex. The function of the CD94-NKG2 receptors is dictated by the pairing of the invariant CD94 polypeptide with specific NKG2 isoforms to form a family of functionally distinct heterodimeric receptors. However, the structural basis for this selective pairing and how they interact with their ligand, HLA-E, is unknown. We describe the 2.5 A resolution crystal structure of CD94-NKG2A in which the mode of dimerization contrasts with that of other homodimeric NK receptors. Despite structural homology between the CD94 and NKG2A subunits, the dimer interface is asymmetric, thereby providing a structural basis for the preferred heterodimeric assembly. Structure-based sequence comparisons of other CD94-NKG2 family members, combined with extensive mutagenesis studies on HLA-E and CD94-NKG2A, allows a model of the interaction between CD94-NKG2A and HLA-E to be established, in which the invariant CD94 chain plays a more dominant role in interacting with HLA-E in comparison to the variable NKG2 chain.

  19. Tilmicosin reduces lipopolysaccharide-stimulated bovine alveolar macrophage prostaglandin E(2) production via a mechanism involving phospholipases.

    PubMed

    Lakritz, Jeffrey; Tyler, Jeff W; Marsh, Antoinette E; Romesburg-Cockrell, Mary; Smith, Kathy; Holle, Julie M

    2002-01-01

    Tilmicosin is a potent antimicrobial with broad-spectrum activity against the bacterial agents involved in the bovine respiratory disease complex. Recent studies indicate that in addition to being bactericidal, tilmicosin is capable of modulating inflammation in the lung. A series of experiments were designed to determine whether tilmicosin alters alveolar macrophage-prostaglandin E(2) (PGE(2)) production induced by Escherichia coli (O55:B5) lipopolysaccharide (LPS). Twenty-two healthy Holstein bull calves were used to study the effects of LPS-induced PGE(2) production of alveolar macrophages after in vivo or in vitro treatment with tilmicosin. In Experiment 1, tilmicosin was given by subcutaneous injection (15 mg/kg) twice, 48 hours apart, to four calves; four control calves received no treatment. Twenty-four hours after the second treatment, alveolar macrophages were stimulated with LPS in vitro. In Experiment 2, alveolar macrophages from five untreated calves were harvested and treated in vitro with tilmicosin, followed by LPS stimulation. In Experiment 3, the ability of in vitro tilmicosin treatment to alter the expression of LPS-induced cyclooxygenase-2 (COX-2) mRNA was evaluated. In Experiments 4 and 5, secretory phospholipase A(2) activity was examined in untreated calves. Treatment of calves with tilmicosin resulted in reduced LPS-induced alveolar macrophage PGE(2) production. Similar reductions in PGE(2) by LPS-stimulated alveolar macrophages after in vitro tilmicosin treatment were noted. This in vitro tilmicosin treatment was not associated with reduction of the expression of LPS-induced COX-2. Alveolar macrophage phospholipase A(2) activity induced by LPS was significantly reduced by prior tilmicosin treatment in vitro. Tilmicosin (in vivo and in vitro) appears to reduce the PGE(2) eicosanoid response of LPS-stimulated alveolar macrophages by reducing the in vitro substrate availability without altering in vitro COX-2 mRNA expression.

  20. Prostaglandin potentiates 5-HT responses in stomach and ileum innervating visceral afferent sensory neurons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Sojin; Jin, Zhenhua; Lee, Goeun

    2015-01-02

    Highlights: • Prostaglandin E2 (PGE{sub 2}) effect was tested on visceral afferent neurons. • PGE{sub 2} did not evoke response but potentiated serotonin (5-HT) currents up to 167%. • PGE{sub 2}-induced potentiation was blocked by E-prostanoid type 4 receptors antagonist. • PGE{sub 2} effect on 5-HT response was also blocked by protein kinase A inhibitor KT5720. • Thus, PGE{sub 2} modulate visceral afferent neurons via synergistic signaling with 5-HT. - Abstract: Gastrointestinal disorder is a common symptom induced by diverse pathophysiological conditions that include food tolerance, chemotherapy, and irradiation for therapy. Prostaglandin E{sub 2} (PGE{sub 2}) level increase was oftenmore » reported during gastrointestinal disorder and prostaglandin synthetase inhibitors has been used for ameliorate the symptoms. Exogenous administration of PGE{sub 2} induces gastrointestinal disorder, however, the mechanism of action is not known. Therefore, we tested PGE{sub 2} effect on visceral afferent sensory neurons of the rat. Interestingly, PGE{sub 2} itself did not evoked any response but enhanced serotonin (5-HT)-evoked currents up to 167% of the control level. The augmented 5-HT responses were completely inhibited by a 5-HT type 3 receptor antagonist, ondansetron. The PGE{sub 2}-induced potentiation were blocked by a selective E-prostanoid type4 (EP{sub 4}) receptors antagonist, L-161,982, but type1 and 2 receptor antagonist AH6809 has no effect. A membrane permeable protein kinase A (PKA) inhibitor, KT5720 also inhibited PGE{sub 2} effects. PGE{sub 2} induced 5-HT current augmentation was observed on 15% and 21% of the stomach and ileum projecting neurons, respectively. Current results suggest a synergistic signaling in visceral afferent neurons underlying gastrointestinal disorder involving PGE{sub 2} potentiation of 5-HT currents. Our findings may open a possibility for screen a new type drugs with lower side effects than currently using steroidal

  1. Three-dimensional culture of sebaceous gland cells revealing the role of prostaglandin E{sub 2}-induced activation of canonical Wnt signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yoshida, Go J., E-mail: medical21go@yahoo.co.jp; Saya, Hideyuki

    Highlights: •Three-dimensional culture generates “semi-vivo” sebaceous glands. •Xenograft model failed to mimic the biology of sebaceous glands in vivo. •Proinflammatory cytokine PGE{sub 2} enhances Wnt signal activity in the organoids. •PGE{sub 2} influences on the mitochondrial and lipid metabolism in the organoids. •Considering 3R agenda, “semi-vivo” sebaceous glands are useful for research. -- Abstract: Background: Prostaglandin E{sub 2} (PGE{sub 2}) is a proinflammatory mediator and activates the canonical Wnt–β-catenin signaling pathway in hematopoietic stem cells. The SZ95 cell line was established from human sebaceous gland cells and is studied as a model system for these cells. Given that 2D culturemore » of SZ95 cells does not recapitulate the organization of sebaceous glands in situ, we developed a 3D culture system for these cells and examined the effects of PGE{sub 2} on cell morphology and function. Results: SZ95 cells maintained in 3D culture formed organoids that mimicked the organization of sebaceous glands in situ, including the establishment of a basement membrane. Organoids exposed to PGE{sub 2} were larger and adopted a more complex organization compared with control organoids. PGE{sub 2} activated the canonical Wnt signaling pathway as well as increased cell viability and proliferation, mitochondrial metabolism, and lipid synthesis in the organoids. Conclusions: Culture of SZ95 cells in 3D culture system recapitulates the structure and susceptibility to PGE{sub 2} of sebaceous glands in situ and should prove useful for studies of the response of these glands to inflammation and other environmental stressors. Our results also implicate PGE{sub 2}-induced activation of canonical Wnt signaling pathway in regulation of the morphology,proliferation, and function of “semi-vivo” sebaceous glands.« less

  2. Effects of Long-Term Daily Administration of Prostaglandin-E2 on Maintaining Elevated Proximal Tibial Metaphyseal Cancellous Bone Mass in Male Rats

    NASA Technical Reports Server (NTRS)

    Ke, Hua Zhu; Jee, Webster S. S.; Mori, Satoshi; Li, Xiao Jian; Kimmel, Donald B.

    1992-01-01

    The effects of long-term prostaglandin E(sub 2) (PGE(sub 2)) on cancellous bone in proximal tibial metaphysis were studied in 7 month old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3, and 6 mg PGE(sub 2)/kg/day and sacrificed after 60, 120, and 180 days. Histomorphometric analyses were performed on double fluorescent-labeled undecalcified bone specimens. After 60 days of treatment, PGE(sub 2) produced diffusely labeled trabecular bone area, increased trabecular bone area, eroded and labeled trabecular perimeter, mineral apposition rate, and bone formation rate at all dose levels when compared with age-matched controls. In rats given PGE(sub 2) for longer time periods (120 and 180 days), trabecular bone area, diffusely labeled trabecular bone area, labeled perimeter, mineral apposition, and bone formation rates were sustained at the elevated levels achieved earlier at 60-day treatment. The eroded perimeter continued to increase until 120 days, then plateau. The observation that continuous systemic PGE(sub 2) administration to adult male rats elevated metaphyseal cancellous bone mass to 3.5-fold of the control level within 60 days and maintained it for another 120 days indicates that the powerful skeletal anabolic effects of PGE2 can be sustained with continuous administration .

  3. Effect of an intraosseous injection of depo-medrol on pulpal concentrations of PGE2 and IL-8 in untreated irreversible pulpitis.

    PubMed

    Isett, James; Reader, Al; Gallatin, Eric; Beck, Mike; Padgett, David

    2003-04-01

    The purpose of this prospective, randomized, double-blind study was to evaluate the pulpal concentrations of prostaglandin E2 (PGE2) and interleukin-8 (IL-8) in untreated teeth with irreversible pulpitis after the administration of an intraosseous injection of Depo-Medrol. Forty emergency patients with a clinical diagnosis of irreversible pulpitis experiencing moderate to severe pain participated. After receiving local anesthesia, patients randomly received, in a double-blind manner, an intraosseous injection of either 1 ml of Depo-Medrol (40 mg) (20 patients) or 1 ml of sterile saline placebo (control) (20 patients). No endodontic treatment was initiated. At 1 or 3 days after the intraosseous injection, the teeth were extracted and the pulpal tissue harvested. Prostaglandin E2 and interleukin-8 concentrations were determined by enzyme immunoassay. Results demonstrated a significantly (p < 0.05) lower concentration of prostaglandin E2 compared to the saline group at day 1. There were no significant (p > 0.05) differences between the two groups at day 3. The pulpal concentrations of prostaglandin E2 were reduced at 1 day after the intraosseous injection of Depo-Medrol.

  4. Advanced Glycation End-Products Induce Apoptosis in Pancreatic Islet Endothelial Cells via NF-κB-Activated Cyclooxygenase-2/Prostaglandin E2 Up-Regulation

    PubMed Central

    Lan, Kuo-Cheng; Chiu, Chen-Yuan; Kao, Chia-Wei; Huang, Kuo-How; Wang, Ching-Chia; Huang, Kuo-Tong; Tsai, Keh-Sung

    2015-01-01

    Microvascular complications eventually affect nearly all patients with diabetes. Advanced glycation end-products (AGEs) resulting from hyperglycemia are a complex and heterogeneous group of compounds that accumulate in the plasma and tissues in diabetic patients. They are responsible for both endothelial dysfunction and diabetic vasculopathy. The aim of this study was to investigate the cytotoxicity of AGEs on pancreatic islet microvascular endothelial cells. The mechanism underlying the apoptotic effect of AGEs in pancreatic islet endothelial cell line MS1 was explored. The results showed that AGEs significantly decreased MS1 cell viability and induced MS1 cell apoptosis in a dose-dependent manner. AGEs dose-dependently increased the expressions of cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in MS1 cells. Treatment of MS1 cells with AGEs also resulted in increased nuclear factor (NF)-κB-p65 phosphorylation and cyclooxygenase (COX)-2 expression. However, AGEs did not affect the expressions of endoplasmic reticulum (ER) stress-related molecules in MS1 cells. Pretreatment with NS398 (a COX-2 inhibitor) to inhibit prostaglandin E2 (PGE2) production reversed the induction of cleaved caspase-3, cleaved PARP, and MS1 cell viability. Moreover, AGEs significantly increased the receptor for AGEs (RAGE) protein expression in MS1 cells, which could be reversed by RAGE neutralizing antibody. RAGE Neutralizing antibody could also reverse the induction of cleaved caspase-3 and cleaved PARP and decreased cell viability induced by AGEs. These results implicate the involvement of NF-κB-activated COX-2/PGE2 up-regulation in AGEs/RAGE-induced islet endothelial cell apoptosis and cytotoxicity. These findings may provide insight into the pathological processes within the pancreatic islet microvasculature induced by AGEs accumulation. PMID:25898207

  5. Induction of labor using prostaglandin E2 (PGE2) vaginal gel in triacetin base. An efficacy study comparing two dosage regimens.

    PubMed

    Seeras, R C; Olatunbosun, O A; Pierson, R A; Turnell, R W

    1995-01-01

    To compare two dosage regimens for the administration of vaginal prostaglandin gel in triacetin base for induction of labor. Seventy subjects planned for elective induction of labor at term were randomized to treatment with PGE2 vaginal gel every 6 or 12 hours. The 6-hourly group received an initial dose of 1 mg, followed by 2 mg at 6 hour intervals for a maximum of two additional doses if not in active labor. The 12-hourly group had an initial dose of 2 mg followed by two additional doses at 12 hour intervals if not in active labor. Successful induction rate was higher in the 12-hourly as compared to 6-hourly gel regimen (100% vs. 91%, P > 0.05). Twelve hours after the initial dose, delivery occurred in 34% delivery had occurred in 57% and 37% respectively (P < 0.01). We found no difference in the induction-active labor interval (P > 0.05), and the induction-delivery interval (P > 0.05) between the two groups. Active labor followed a single dose of gel in 66% of the 12-hourly group compared to 40% of the 6-hourly group (P < 0.01). Syntocinon augmentation was needed in 6% of subjects in the 12-hourly group as compared to 26% in the 6-hourly group (P < 0.01). The cesarean section rate was similar in both groups. Uterine hyperstimulation occurred less frequently in the 12-hourly group (P < 0.05). The perinatal outcome was similar in both groups. The 12-hourly regimen was more effective than the 6-hourly regimen in initiating labor. The majority of the subjects in the 12 hourly group achieved labor following a single dose of gel. Induction delivery interval, however, was similar in both groups.

  6. Predominant Role of Cytosolic Phospholipase A2α in Dioxin-induced Neonatal Hydronephrosis in Mice

    PubMed Central

    Yoshioka, Wataru; Kawaguchi, Tatsuya; Fujisawa, Nozomi; Aida-Yasuoka, Keiko; Shimizu, Takao; Matsumura, Fumio; Tohyama, Chiharu

    2014-01-01

    Hydronephrosis is a common disease characterized by dilation of the renal pelvis and calices, resulting in loss of kidney function in the most severe cases. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces nonobstructive hydronephrosis in mouse neonates through upregulation of prostaglandin E2 (PGE2) synthesis pathway consisting of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) by a yet unknown mechanism. We here studied possible involvement of cytosolic phospholipase A2α (cPLA2α) in this mechanism. To this end, we used a cPLA2α-null mouse model and found that cPLA2α has a significant role in the upregulation of the PGE2 synthesis pathway through a noncanonical pathway of aryl hydrocarbon receptor. This study is the first to demonstrate the predominant role of cPLA2α in hydronephrosis. Elucidation of the pathway leading to the onset of hydronephrosis using the TCDD-exposed mouse model will deepen our understanding of the molecular basis of nonobstructive hydronephrosis in humans. PMID:24509627

  7. The protective effect of the EP2 receptor on TGF-β1 induced podocyte injury via the PI3K / Akt signaling pathway

    PubMed Central

    Zhu, Xue-ling; Chen, Xu; Wu, Jian-hua; Guo, Nai-feng

    2018-01-01

    Transforming growth factor β1 (TGF-β1) plays a central role in chronic kidney diseases. TGF-β1 induction causes podocyte injury, which results in proteinuria and renal failure. However, the effect of the prostaglandin E2 /E-prostanoid receptor (EP2) on TGF-β1-induced podocyte injury remains unknown. Previous studies have shown that phosphoinositide 3-OH kinase (PI3K)/Akt is widespread in cells, and is vital for the regulation of cell proliferation, differentiation, apoptosis and metabolism. In this study, we cultured immortalized mouse podocytes in vitro in different groups: control group; TGF-β1 (5ng/ml) group; EP2 agonist Butaprost treatment (10−7, 10−6, or 10-5mol/L) +TGF-β1 group; EP2 antagonist AH6809 treatment (10−7, 10−6, or 10-5mol / L) + TGF-β1 group. We found that compared with the control group, proliferation of podocytes in the TGF-β1 group significantly decreased and apoptosis increased. Expression of cAMP decreased, whereas PGE2 increased. Meanwhile, expressions of nephrin, podocin and CD2AP mRNA and protein were dramatically downregulated, activated caspase-3 was increased, and activated PI3K/Akt activity were depressed. Butaprost intervention promoted podocyte proliferation with reduced apoptosis. Conversely, AH6809 intervention led to opposite results (P<0.05). Our findings suggested that EP2 agonist protects podocytes by increasing expression of cAMP, which creates feedback of inhibiting PGE2 expression. This causes the interaction of nephrin, podocin and CD2AP resulting the inhibition of apoptosis induced by activation of the PI3K / Akt signaling pathway. PMID:29746568

  8. The effect of intra-articular botulinum toxin A on substance P, prostaglandin E2, and tumor necrosis factor alpha in the canine osteoarthritic joint.

    PubMed

    Heikkilä, Helka M; Hielm-Björkman, Anna K; Innes, John F; Laitinen-Vapaavuori, Outi M

    2017-03-21

    Recently, intra-articular botulinum toxin A (IA BoNT A) has been shown to reduce joint pain in osteoarthritic dogs. Similar results have been reported in human patients with arthritis. However, the mechanism of the antinociceptive action of IA BoNT A is currently not known. The aim of this study was to explore this mechanism of action by investigating the effect of IA BoNT A on synovial fluid (SF) and serum substance P (SP), prostaglandin E 2 (PGE 2 ), and tumor necrosis factor alpha (TNF-α) in osteoarthritic dogs. Additionally, the aim was to compare SF SP and PGE 2 between osteoarthritic and non-osteoarthritic joints, and investigate associations between SP, PGE 2 , osteoarthritic pain, and the signalment of dogs. Thirty-five dogs with chronic naturally occurring osteoarthritis and 13 non-osteoarthritic control dogs were included in the study. Osteoarthritic dogs received either IA BoNT A (n = 19) or IA placebo (n = 16). Serum and SF samples were collected and osteoarthritic pain was evaluated before (baseline) and 2 and 8 weeks after treatment. Osteoarthritic pain was assessed with force platform, Helsinki Chronic Pain Index, and joint palpation. Synovial fluid samples were obtained from control dogs after euthanasia. The change from baseline in SP and PGE 2 concentration was compared between the IA BoNT A and placebo groups. The synovial fluid SP and PGE 2 concentration was compared between osteoarthritic and control joints. Associations between SP, PGE 2 , osteoarthritic pain, and the signalment of dogs were evaluated. There was no significant change from baseline in SP or PGE 2 after IA BoNT A. Synovial fluid PGE 2 was significantly higher in osteoarthritic compared to control joints. Synovial fluid PGE 2 correlated with osteoarthritic pain. No associations were found between SP or PGE 2 and the signalment of dogs. The concentration of TNF-α remained under the detection limit of the assay in all samples. The results suggest that the antinociceptive

  9. ER stress upregulated PGE2/IFNγ-induced IL-6 expression and down-regulated iNOS expression in glial cells

    NASA Astrophysics Data System (ADS)

    Hosoi, Toru; Honda, Miya; Oba, Tatsuya; Ozawa, Koichiro

    2013-12-01

    The disruption of endoplasmic reticulum (ER) function can lead to neurodegenerative disorders, in which inflammation has also been implicated. We investigated the possible correlation between ER stress and immune function using glial cells. We demonstrated that ER stress synergistically enhanced prostaglandin (PG) E2 + interferon (IFN) γ-induced interleukin (IL)-6 production. This effect was mediated through cAMP. Immune-activated glial cells produced inducible nitric oxide synthase (iNOS). Interestingly, ER stress inhibited PGE2 + IFNγ-induced iNOS expression. Similar results were obtained when cells were treated with dbcAMP + IFNγ. Thus, cAMP has a dual effect on immune reactions; cAMP up-regulated IL-6 expression, but down-regulated iNOS expression under ER stress. Therefore, our results suggest a link between ER stress and immune reactions in neurodegenerative diseases.

  10. Prostaglandin E2 activates the mTORC1 pathway through an EP4/cAMP/PKA- and EP1/Ca2+-mediated mechanism in the human pancreatic carcinoma cell line PANC-1.

    PubMed

    Chang, Hui-Hua; Young, Steven H; Sinnett-Smith, James; Chou, Caroline Ei Ne; Moro, Aune; Hertzer, Kathleen M; Hines, Oscar Joe; Rozengurt, Enrique; Eibl, Guido

    2015-11-15

    Obesity, a known risk factor for pancreatic cancer, is associated with inflammation and insulin resistance. Proinflammatory prostaglandin E2 (PGE2) and elevated insulin-like growth factor type 1 (IGF-1), related to insulin resistance, are shown to play critical roles in pancreatic cancer progression. We aimed to explore a potential cross talk between PGE2 signaling and the IGF-1/Akt/mammalian target of rapamycin complex 1 (mTORC1) pathway in pancreatic cancer, which may be a key to unraveling the obesity-cancer link. In PANC-1 human pancreatic cancer cells, we showed that PGE2 stimulated mTORC1 activity independently of Akt, as evaluated by downstream signaling events. Subsequently, using pharmacological and genetic approaches, we demonstrated that PGE2-induced mTORC1 activation is mediated by the EP4/cAMP/PKA pathway, as well as an EP1/Ca(2+)-dependent pathway. The cooperative roles of the two pathways were supported by the maximal inhibition achieved with the combined pharmacological blockade, and the coexistence of highly expressed EP1 (mediating the Ca(2+) response) and EP2 or EP4 (mediating the cAMP/PKA pathway) in PANC-1 cells and in the prostate cancer line PC-3, which also robustly exhibited PGE2-induced mTORC1 activation, as identified from a screen in various cancer cell lines. Importantly, we showed a reinforcing interaction between PGE2 and IGF-1 on mTORC1 signaling, with an increase in IL-23 production as a cellular outcome. Our data reveal a previously unrecognized mechanism of PGE2-stimulated mTORC1 activation mediated by EP4/cAMP/PKA and EP1/Ca(2+) signaling, which may be of great importance in elucidating the promoting effects of obesity in pancreatic cancer. Ultimately, a precise understanding of these molecular links may provide novel targets for efficacious interventions devoid of adverse effects. Copyright © 2015 the American Physiological Society.

  11. Somatostatin, prostaglandin E2 and atropine inhibition of the gastric actions of bombesin in the dog.

    PubMed

    Hirschowitz, B I; Molina, E

    1984-01-01

    Bombesin, acetylcholine, prostaglandins and somatostatin are all thought to be involved in the regulation of gastrin release and gastric secretion. We have studied the effects of low doses of atropine, 16-16(Me)2-prostaglandin E2 (PGE2) and somatostatin-14 on bombesin-stimulated gastrin release and gastric acid and pepsin secretion in conscious fistula dogs. For reference, synthetic gastrin G-17 was studied with and without somatostatin. Bombesin, in a dose-related manner, increased serum gastrin, which in turn stimulated gastric acid and pepsin secretion in a serum gastrin, concentration-dependent manner. Somatostatin inhibited gastrin release by bombesin as well as the secretory stimulation by G-17; the combination of sequential effects resulted in a marked inhibition of bombesin-stimulated gastric acid and pepsin secretion. PGE2 also strongly inhibited gastrin release and acid and pepsin secretion. Atropine had no significant effect on gastrin release, but greatly inhibited gastric secretion. Thus somatostatin and PGE2 inhibited at two sites, gastrin release and gastrin effects, while atropine affected only the latter.

  12. Saliva, Serum Levels of Interleukin-21, -33 and Prostaglandin E2 in Patients with Generalised Aggressive or Chronic Periodontitis.

    PubMed

    Gümüş, Pınar; Nizam, Nejat; Nalbantsoy, Ayşe; Özçaka, Özgün; Buduneli, Nurcan

    This cross-sectional study aims to evaluate saliva, serum levels of interleukin-21 (IL-21), IL-33, and prostaglandin E2 (PGE2) in patients with generalised chronic periodontitis or aggressive periodontitis. Before initiation of any periodontal treatment, saliva and serum samples were collected and clinical periodontal measurements were recorded from 94 participants (25 aggressive periodontitis patients, 25 chronic periodontitis patients, 44 periodontally healthy individuals). IL-21, IL-33 and PGE2 levels in serum and saliva samples were determined by ELISA. Data were tested statistically using Kruskal-Wallis, Mann-Whitney U-, and Spearman-rho rank tests. Saliva IL-33 levels were statistically significantly higher in the chronic than the aggressive group (p < 0.05). Serum IL-33, saliva and serum IL-21 and PGE2 levels were similar in the two periodontitis groups. Saliva IL-33 levels correlated with age in the chronic periodontitis group (p < 0.05). Statistically significant positive correlations were found between serum, saliva PGE2 levels and plaque index (p < 0.05). IL-33 and IL-21 levels in serum samples positively correlated in the periodontitis groups (p < 0.05). IL-21 and PGE2 analysis did not exhibit discriminating data between generalised chronic and aggressive periodontitis, but the present findings support the role of these cytokines in periodontitis. Statistically significantly higher saliva IL-33 levels in the chronic periodontitis group warrant further research.

  13. Prostaglandin D2 regulates human colonic ion transport via the DP1 receptor.

    PubMed

    Medani, M; Collins, D; Mohan, H M; Walsh, E; Winter, D C; Baird, A W

    2015-02-01

    Prostaglandin D2 is released by mast cells and is important in allergies. Its role in gastrointestinal function is not clearly defined. This study aimed to determine the effect of exogenous PGD2 on ion transport in ex vivo normal human colonic mucosa. Mucosal sheets were mounted in Ussing chambers and voltage clamped to zero electric potential. Ion transport was quantified as changes in short-circuit current. In separate experiments epithelial monolayers or colonic crypts, isolated by calcium chelation, were treated with PGD2 and cAMP levels determined by ELISA or calcium levels were determined by fluorimetry. PGD2 caused a sustained, concentration-dependent rise in short-circuit current by increasing chloride secretion (EC50=376nM). This effect of PGD2 is mediated by the DP1 receptor, as the selective DP1 receptor antagonist BW A686C inhibited PGD2-induced but not PGE2-induced rise in short-circuit current. PGD2 also increased intracellular cAMP in isolated colonic crypts with no measurable influence on cytosolic calcium. PGD2 induces chloride secretion in isolated human colonic mucosa in a concentration-dependent manner with concomitant elevation of cytoplasmic cAMP in epithelial cells. The involvement of DP2 receptor subtypes has not previously been considered in regulation of ion transport in human intestine. Since inflammatory stimuli may induce production of eicosanoids, selective regulation of these pathways may be pivotal in determining therapeutic strategies and in understanding disease. Copyright © 2014. Published by Elsevier Inc.

  14. A Topographical Atlas of Shiga Toxin 2e Receptor Distribution in the Tissues of Weaned Piglets.

    PubMed

    Steil, Daniel; Bonse, Robert; Meisen, Iris; Pohlentz, Gottfried; Vallejo, German; Karch, Helge; Müthing, Johannes

    2016-11-30

    Shiga toxin (Stx) 2e of Stx-producing Escherichia coli (STEC) is the primary virulence factor in the development of pig edema disease shortly after weaning. Stx2e binds to the globo-series glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer, Galα1-4Galβ1-4Glcβ1-1Cer) and globotetraosylceramide (Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1Cer), the latter acting as the preferential Stx2e receptor. We determined Stx receptor profiles of 25 different tissues of a male and a female weaned piglet using immunochemical solid phase binding assays combined with mass spectrometry. All probed tissues harbored GSL receptors, ranging from high (category I) over moderate (category II) to low content (category III). Examples of Gb4Cer expression in category I tissues are small intestinal ileum, kidney pelvis and whole blood, followed by colon, small intestinal duodenum and jejunum belonging to category II, and kidney cortex, cerebrum and cerebellum as members of category III organs holding true for both genders. Dominant Gb3Cer and Gb4Cer lipoforms were those with ceramides carrying constant sphingosine (d18:1) and a variable C16:0, C22:0 or C24:1/C24:0 fatty acid. From the mapping data, we created a topographical atlas for Stx2e receptors in piglet tissues and organs, which might be helpful to further investigations on the molecular and cellular mechanisms that underlie infections of Stx2e-producing STEC in pigs and their zoonotic potential for humans.

  15. A Topographical Atlas of Shiga Toxin 2e Receptor Distribution in the Tissues of Weaned Piglets

    PubMed Central

    Steil, Daniel; Bonse, Robert; Meisen, Iris; Pohlentz, Gottfried; Vallejo, German; Karch, Helge; Müthing, Johannes

    2016-01-01

    Shiga toxin (Stx) 2e of Stx-producing Escherichia coli (STEC) is the primary virulence factor in the development of pig edema disease shortly after weaning. Stx2e binds to the globo-series glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer, Galα1-4Galβ1-4Glcβ1-1Cer) and globotetraosylceramide (Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1Cer), the latter acting as the preferential Stx2e receptor. We determined Stx receptor profiles of 25 different tissues of a male and a female weaned piglet using immunochemical solid phase binding assays combined with mass spectrometry. All probed tissues harbored GSL receptors, ranging from high (category I) over moderate (category II) to low content (category III). Examples of Gb4Cer expression in category I tissues are small intestinal ileum, kidney pelvis and whole blood, followed by colon, small intestinal duodenum and jejunum belonging to category II, and kidney cortex, cerebrum and cerebellum as members of category III organs holding true for both genders. Dominant Gb3Cer and Gb4Cer lipoforms were those with ceramides carrying constant sphingosine (d18:1) and a variable C16:0, C22:0 or C24:1/C24:0 fatty acid. From the mapping data, we created a topographical atlas for Stx2e receptors in piglet tissues and organs, which might be helpful to further investigations on the molecular and cellular mechanisms that underlie infections of Stx2e-producing STEC in pigs and their zoonotic potential for humans. PMID:27916888

  16. Evaluation of peri-implant crevicular fluid prostaglandin E2 levels in augmented extraction sockets by different biomaterials.

    PubMed

    Alkan, Eylem Ayhan; Tüter, Gülay; Parlar, Ateş; Yücel, Ayşegül; Kurtiş, Bülent

    2016-10-01

    This study compares peri-implant crevicular fluid (PICF) prostaglandin E 2 (PGE 2 ) levels, clinical parameters and implant stability quotient (ISQ) values around implants placed in augmented extraction sockets. The sockets (24 in total) were randomly augmented using either EMD or Bio-Oss Collagen. Implant placements were performed after three months of healing. ISQ readings were evaluated at three points: at the time of surgery, at the first month and at the third month. PICF was collected for PGE 2 evaluation after the first and the third months of implant surgery. After the first month, a higher level of PICF PGE 2 was observed in the EMD group than in the Bio-Oss Collagen group, and this increase was of statistical significance; however, at the third month there was no statistically significant difference in PICF PGE 2 levels between the two groups. For implants placed in EMD sites, ISQ values were statistically higher at the third month than at the first month, while no significant differences in ISQ value were detected between the first and third months in Bio-Oss Collagen sites. The results of this research suggest that both EMD and Bio-Oss Collagen are effective treatment modalities for stimulating the formation of new bone at extraction sites prior to implant surgery.

  17. Influence of increased mechanical loading by hypergravity on the microtubule cytoskeleton and prostaglandin E2 release in primary osteoblasts

    NASA Technical Reports Server (NTRS)

    Searby, Nancy D.; Steele, Charles R.; Globus, Ruth K.

    2005-01-01

    Cells respond to a wide range of mechanical stimuli such as fluid shear and strain, although the contribution of gravity to cell structure and function is not understood. We hypothesized that bone-forming osteoblasts are sensitive to increased mechanical loading by hypergravity. A centrifuge suitable for cell culture was developed and validated, and then primary cultures of fetal rat calvarial osteoblasts at various stages of differentiation were mechanically loaded using hypergravity. We measured microtubule network morphology as well as release of the paracrine factor prostaglandin E2 (PGE2). In immature osteoblasts, a stimulus of 10x gravity (10 g) for 3 h increased PGE2 2.5-fold and decreased microtubule network height 1.12-fold without affecting cell viability. Hypergravity (3 h) caused dose-dependent (5-50 g) increases in PGE2 (5.3-fold at 50 g) and decreases (1.26-fold at 50 g) in microtubule network height. PGE2 release depended on duration but not orientation of the hypergravity load. As osteoblasts differentiated, sensitivity to hypergravity declined. We conclude that primary osteoblasts demonstrate dose- and duration-dependent sensitivity to gravitational loading, which appears to be blunted in mature osteoblasts.

  18. Recognition of the Class Ib Molecule Qa-1b by Putative Activating Receptors Cd94/Nkg2c and Cd94/Nkg2e on Mouse Natural Killer Cells

    PubMed Central

    Vance, Russell E.; Jamieson, Amanda M.; Raulet, David H.

    1999-01-01

    The heterodimeric CD94/NKG2A receptor, expressed by mouse natural killer (NK) cells, transduces inhibitory signals upon recognition of its ligand, Qa-1b, a nonclassical major histocompatibility complex class Ib molecule. Here we clone and express two additional receptors, CD94/NKG2C and CD94/NKG2E, which we show also bind to Qa-1b. Within their extracellular carbohydrate recognition domains, NKG2C and NKG2E share extensive homology with NKG2A (93–95% amino acid similarity); however, NKG2C/E receptors differ from NKG2A in their cytoplasmic domains (only 33% similarity) and contain features that suggest that CD94/NKG2C and CD94/NKG2E may be activating receptors. We employ a novel blocking anti-NKG2 monoclonal antibody to provide the first direct evidence that CD94/NKG2 molecules are the only Qa-1b receptors on NK cells. Molecular analysis reveals that NKG2C and NKG2E messages are extensively alternatively spliced and ∼20-fold less abundant than NKG2A message in NK cells. The organization of the mouse Cd94/Nkg2 gene cluster, presented here, shows striking similarity with that of the human, arguing that the entire CD94/NKG2 receptor system is relatively primitive in origin. Analysis of synonymous substitution frequencies suggests that within a species, NKG2 genes may maintain similarities with each other by concerted evolution, possibly involving gene conversion–like events. These findings have implications for understanding NK cells and also raise new possibilities for the role of Qa-1 in immune responses. PMID:10601355

  19. The importance of the adenosine A(2A) receptor-dopamine D(2) receptor interaction in drug addiction.

    PubMed

    Filip, M; Zaniewska, M; Frankowska, M; Wydra, K; Fuxe, K

    2012-01-01

    Drug addiction is a serious brain disorder with somatic, psychological, psychiatric, socio-economic and legal implications in the developed world. Illegal (e.g., psychostimulants, opioids, cannabinoids) and legal (alcohol, nicotine) drugs of abuse create a complex behavioral pattern composed of drug intake, withdrawal, seeking and relapse. One of the hallmarks of drugs that are abused by humans is that they have different mechanisms of action to increase dopamine (DA) neurotransmission within the mesolimbic circuitry of the brain and indirectly activate DA receptors. Among the DA receptors, D(2) receptors are linked to drug abuse and addiction because their function has been proven to be correlated with drug reinforcement and relapses. The recognition that D(2) receptors exist not only as homomers but also can form heteromers, such as with the adenosine (A)(2A) receptor, that are pharmacologically and functionally distinct from their constituent receptors, has significantly expanded the range of potential drug targets and provided new avenues for drug design in the search for novel drug addiction therapies. The aim of this review is to bring current focus on A(2A) receptors, their physiology and pharmacology in the central nervous system, and to discuss the therapeutic relevance of these receptors to drug addiction. We concentrate on the contribution of A(2A) receptors to the effects of different classes of drugs of abuse examined in preclinical behavioral experiments carried out with pharmacological and genetic tools. The consequences of chronic drug treatment on A(2A) receptor-assigned functions in preclinical studies are also presented. Finally, the neurochemical mechanism of the interaction between A(2A) receptors and drugs of abuse in the context of the heteromeric A(2A)-D(2) receptor complex is discussed. Taken together, a significant amount of experimental analyses provide evidence that targeting A(2A) receptors may offer innovative translational strategies

  20. Cancer/stroma interplay via cyclooxygenase-2 and indoleamine 2,3-dioxygenase promotes breast cancer progression.

    PubMed

    Chen, Jing-Yi; Li, Chien-Feng; Kuo, Cheng-Chin; Tsai, Kelvin K; Hou, Ming-Feng; Hung, Wen-Chun

    2014-07-25

    Expression of indoleamine 2,3-dioxygenase (IDO) in primary breast cancer increases tumor growth and metastasis. However, the clinical significance of stromal IDO and the regulation of stromal IDO are unclear. Metabolomics and enzyme-linked immunosorbent assay (ELISA) were used to study the effect of cyclooxygenase-2 (COX-2)-overexpressing breast cancer cells on IDO expression in co-cultured human breast fibroblasts. Biochemical inhibitors and short-hairpin RNA (shRNA) were used to clarify how prostaglandin E2 (PGE2) upregulates IDO expression. Associations of stromal IDO with clinicopathologic parameters were tested in tumor specimens. An orthotopic animal model was used to examine the effect of COX-2 and IDO inhibitors on tumor growth. Kynurenine, the metabolite generated by IDO, increases in the supernatant of fibroblasts co-cultured with COX-2-overexpressing breast cancer cells. PGE2 released by cancer cells upregulates IDO expression in fibroblasts through an EP4/signal transducer and activator of transcription 3 (STAT3)-dependent pathway. Conversely, fibroblast-secreted kynurenine promotes the formation of the E-cadherin/Aryl hydrocarbon receptor (AhR)/S-phase kinase-associated protein 2 (Skp2) complex, resulting in degradation of E-cadherin to increase breast cancer invasiveness. The enhancement of motility of breast cancer cells induced by co-culture with fibroblasts is suppressed by the IDO inhibitor 1-methyl-tryptophan. Pathological analysis demonstrates that upregulation of stromal IDO is a poor prognosis factor and is associated with of COX-2 overexpression. Co-expression of cancer COX-2 and stromal IDO predicts a worse disease-free and metastasis-free survival. Finally, COX-2 and IDO inhibitors inhibit tumor growth in vivo. Integration of metabolomics and molecular and pathological approaches reveals the interplay between cancer and stroma via COX-2, and IDO promotes tumor progression and predicts poor patient survival.

  1. Effect of PGE2 and LTB4 on vicia villosa binding lymphocytes.

    PubMed

    Gualde, N; Cook, J M; Guibert, F

    1988-06-01

    Since there is a good deal of evidence that vicia villosa lectin (VVA) binds to contrasuppressor cells, mouse splenocytes and thymocytes were sorted by binding to VVA-coated Petri dishes. It was observed that vicia villosa adherent cells (VVA(+)) did not proliferate when mitogens were added to cultures, but they did enhance the thymidine uptake of PHA or ConA stimulated vicia villosa non-adherent (VVA(-)) splenocytes. PGE2 treatment of VVA(+) splenocytes or VVA(+) immature thymocytes did not very much affect the VVA(+) cell behavior. On the other hand, LTB4 increased the enhancing capability of VVA(+) splenocytes. Therefore, investigations dealing with the effects of LTB4 on lymphocyte subsets which may include VVA(+) cells should take into consideration the possible presence of contrasuppressor cells.

  2. Effects of Litchi chinensis fruit isolates on prostaglandin E2 and nitric oxide production in J774 murine macrophage cells

    PubMed Central

    2012-01-01

    Background Litchi chinensis is regarded as one of the 'heating' fruits in China, which causes serious inflammation symptoms to people. Methods In the current study, the effects of isolates of litchi on prostaglandin E2 (PGE2) and nitric oxide (NO) production in J774 murine macrophage cells were investigated. Results The AcOEt extract (EAE) of litchi was found effective on stimulating PGE2 production, and three compounds, benzyl alcohol, hydrobenzoin and 5-hydroxymethyl-2-furfurolaldehyde (5-HMF), were isolated and identified from the EAE. Benzyl alcohol caused markedly increase in PGE2 and NO production, compared with lipopolysaccharide (LPS) as positive control, and in a dose-dependent manner. Hydrobenzoin and 5-HMF were found in litchi for the first time, and both of them stimulated PGE2 and NO production moderately in a dose-dependent manner. Besides, regulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA expression and NF-κB (p50) activation might be involved in mechanism of the stimulative process. Conclusion The study showed, some short molecular compounds in litchi play inflammatory effects on human. PMID:22380404

  3. Presenilin 1 mutations influence processing and trafficking of the ApoE receptor apoER2.

    PubMed

    Wang, Wei; Moerman-Herzog, Andrea M; Slaton, Arthur; Barger, Steven W

    2017-01-01

    Presenilin (PS)-1 is an intramembrane protease serving as the catalytic component of γ-secretase. Mutations in the PS1 gene are the most common cause of familial Alzheimer's disease (FAD). The low-density lipoprotein (LDL)-receptor family member apoER2 is a γ-secretase substrate that has been associated with AD in several ways, including acting as a receptor for apolipoprotein E (ApoE). ApoER2 is processed by γ-secretase into a C-terminal fragment (γ-CTF) that appears to regulate gene expression. FAD PS1 mutations were tested for effects on apoER2. PS1 mutation R278I showed impaired γ-secretase activity for apoER2 in the basal state or after exposure to Reelin. PS1 M146V mutation permitted accumulation of apoER2 CTFs after Reelin treatment, whereas no difference was seen between wild-type (WT) and M146V in the basal state. PS1 L282V mutation, combined with the γ-secretase inhibitor N-(N-[3,5-Difluorophenacetyl]-L-alanyl)-S-phenylglycine t-butyl ester, greatly reduced the cell-surface levels of apoER2 without affecting total apoER2 levels, suggesting a defect in receptor trafficking. These findings indicate that impaired processing or localization of apoER2 may contribute to the pathogenic effects of FAD mutations in PS1. Published by Elsevier Inc.

  4. Activation of G proteins mediates flow-induced prostaglandin E2 production in osteoblasts

    NASA Technical Reports Server (NTRS)

    Reich, K. M.; McAllister, T. N.; Gudi, S.; Frangos, J. A.

    1997-01-01

    Interstitial fluid flow may play a role in load-induced bone remodeling. Previously, we have shown that fluid flow stimulates osteoblast production of cAMP inositol trisphosphate (IP3), and PGE2. Flow-induced increases in cAMP and IP3 were shown to be a result of PG production. Thus, PGE2 production appears to be an important component in fluid flow induced signal transduction. In the present study, we investigated the mechanism of flow-induced PGE2 synthesis. Flow-induced a 20-fold increase in PGE2 production in osteoblasts. Increases were also observed with ALF4-(10mM) (98-fold), an activator of guanidine nucleotide-binding proteins (G proteins), and calcium ionophore A23187 (2 microM) (100-fold) in stationary cells. We then investigated whether flow stimulation is mediated by G proteins and increases in intracellular calcium. Flow-induced PGE2 production was inhibited by the G protein inhibitors GDP beta S (100 microM) and pertussis toxin (1 microgram/ml) by 83% and 72%, respectively. Chelation of extracellular calcium by EGTA (2 mM) and intracellular calcium by quin-2/AM (30 microM) blocked flow stimulation by 87% and 67%, respectively. These results suggest that G proteins and calcium play an important role in mediating mechanochemical signal transduction in osteoblasts.

  5. Prostaglandin E2 activates channel-mediated calcium entry in human erythrocytes: an indication for a blood clot formation supporting process.

    PubMed

    Kaestner, Lars; Tabellion, Wiebke; Lipp, Peter; Bernhardt, Ingolf

    2004-12-01

    Prostaglandin E(2) (PGE(2)) is released from platelets when they are activated. Using fluorescence imaging and the patch-clamp technique, we provide evidence that PGE(2) at physiological concentrations (10(-10) M) activates calcium rises mediated by calcium influx through a non-selective cation-channel in human red blood cells. The extent of calcium increase varied between cells with a total of 45% of the cells responding. It is well known that calcium increases elicited the calcium-activated potassium channel (Gardos channel) in the red cell membrane. Previously, it was shown that the Gardos channel activation results in potassium efflux and shrinkage of the cells. Therefore, we conclude that the PGE(2) responses of red blood cells described here reveal a direct and active participation of erythrocytes in blood clot formation.

  6. Increased levels of urinary PGE-M, a biomarker of inflammation, occur in association with obesity, aging and lung metastases in patients with breast cancer

    PubMed Central

    Morris, Patrick G.; Zhou, Xi Kathy; Milne, Ginger L.; Goldstein, Daniel; Hawks, Laura C.; Dang, Chau T.; Modi, Shanu; Fornier, Monica N.; Hudis, Clifford A.; Dannenberg, Andrew J.

    2013-01-01

    Elevated levels of cyclooxygenase (COX)-derived prostaglandin E2 (PGE2) occur in inflamed tissues. To evaluate the potential links between inflammation and breast cancer, levels of urinary prostaglandin E-metabolite (PGE-M), a stable end metabolite of PGE2, were quantified. We enrolled 400 patients with breast cancer: controls with early breast cancer (n=200), lung metastases (n=100) and metastases to other sites (n=100). Patients completed a questionnaire, provided urine and had measurements of height and weight. Urinary PGE-M was quantified by mass spectrometry. Ever smokers with lung metastasis who had not been exposed to NSAIDs had the highest PGE-M levels. PGE-M levels were increased in association with elevated BMI (p<0.001), aging (p<0.001), pack-year smoking history (p=0.02), lung metastases (p=0.02) and recent cytotoxic chemotherapy (p=0.03). Conversely, use of NSAIDs, prototypic inhibitors of COX activity, was associated with reduced PGE-M levels (p<0.001). Based on the current findings, PGE-M is likely to be a useful biomarker for the selection of high risk subgroups to determine the utility of interventions that aim to reduce inflammation and possibly the development and progression of breast cancer, especially in overweight and obese women. PMID:23531446

  7. Topical 0.1% Bromfenac Sodium for Intraoperative Miosis Prevention and Prostaglandin E2 Inhibition in Femtosecond Laser-Assisted Cataract Surgery.

    PubMed

    Chen, Hui; Lin, Haotian; Chen, Wan; Zhang, Bo; Xiang, Wu; Li, Jing; Chen, Weirong

    2017-04-01

    The purpose of this study was to evaluate the effect of topical 0.1% bromfenac sodium, a nonsteroidal anti-inflammatory drug (NSAID), on intraoperative pupil dilation maintenance and prostaglandin E 2 (PGE 2 ) inhibition during femtosecond laser-assisted cataract surgery. Sixty patients (30 each in study and control groups) were included in this study. The patients received 0.1% bromfenac ophthalmic solution or control placebo twice a day for 3 days before surgery. Pupil size was measured at the initiation of femtosecond laser pretreatment and phacoemulsification. Aqueous humor was collected at the beginning of routine cataract surgery. PGE 2 levels were measured with an enzyme-linked immunoassay. Laser flare photometry was measured preoperatively and at 1 day postoperatively. Compared with untreated patients, the change in pupil size and postoperative day 1 aqueous flare were significantly reduced throughout the operation in the patients treated with 0.1% bromfenac (P < 0.001). Mean PGE 2 concentrations were also significantly decreased by treatment with 0.1% bromfenac (P < 0.001). The reduction of the pupil area and postoperative day 1 aqueous flare were significantly correlated with PGE 2 levels (P < 0.001). NSAID treatment, when administered before femtosecond laser-assisted cataract surgery, was effective in maintaining intraoperative pupil dilation, preventing miosis, and reducing PGE 2 levels.

  8. [Association of CD(+)4 T lymphocyte count and gingival crevicular fluid prostaglandin E2 with periodontal parameters in HIV-positive periodontitis patients].

    PubMed

    Jia, Hongcheng; Wang, Xuan; Hua, Wenhao; Li, Xiaoguang; Hou, Wen; Fu, Qian

    2014-02-01

    To investigate the correlation of CD(+)4 T lymphocyte count and prostaglandin E2 (PGE2) in gingival crevicular fluid (GCF) with periodontal status in HIV-positive patients with periodontitis. Twenty subjects were selected according to inclusion criteria. The plasmatic CD(+)4 T lymphocytes were counted. All the individuals were divided into three groups, group A (CD(+)4 T lymphocyte count < 200 cell/mm(3)), group B (200 cell/mm(3) ≤ CD(+)4 T lymphocyte count ≤ 500 cell/mm(3)) and group C (CD(+)4 T lymphocyte count > 500 cell/mm(3)). Periodontal indexes, including plaque index(PLI), bleeding index(BI), attachment level(AL) and probing depth(PD) were recorded.GCF samples were taken from 120 index teeth by means of sterile paper strips.GCF PGE2 levels were determined by radioimmunoassays. Mann-Whitney was used to compare the periodontal indexes and PGE2 levels among the three groups. Partial correlations and Spearman correlations were applied to analyze the correlation of CD(+)4 T lymphocytes count and PGE2 in gingival crevicular fluid with periodontal status. BI value, PGE2 concentration and total PGE2 were 3.00(2.00), 90.75(30.60) µg/L, 447.58 (243.08) pg in group B, which were higher than those in group A[2.00(1.25), 79.75(30.50) µg/L and 339.52 (200.97) pg respectively] and group C[2.00(1.00), 73.38 (14.83) µg/L and 299.18 (108.33) pg respectively] (P < 0.0167). But the differences of PD and AL among the three groups were not significantly different(P > 0.0167). The correlations were observed between CD(+)4 T lymphocyte count and BI for the subpopulations with CD(+)4 T lymphocyte count <200 cells/mm(3) (r = 0.657, P < 0.05) and between 200-500 cells/mm(3) (r = -0.369, P < 0.05). PGE2 concentration was negatively correlated with BI, PD and AL (P < 0.05), and total PGE2 was positively correlated with PD and AL(P < 0.05). There was an association between the periodontal status and CD(+)4 T lymphocyte count in HIV(+) patients.GCF PGE2 level was related to

  9. Functional expression of 5-HT{sub 2A} receptor in osteoblastic MC3T3-E1 cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hirai, Takao; Kaneshige, Kota; Kurosaki, Teruko

    2010-05-28

    In the previous study, we reported the gene expression for proteins related to the function of 5-hydroxytryptamine (5-HT, serotonin) and elucidated the expression patterns of 5-HT{sub 2} receptor subtypes in mouse osteoblasts. In the present study, we evaluated the possible involvement of 5-HT receptor subtypes and its inactivation system in MC3T3-E1 cells, an osteoblast cell line. DOI, a 5-HT{sub 2A} and 5-HT{sub 2C} receptor selective agonist, as well as 5-HT concentration-dependently increased proliferative activities of MC3T3-E1 cells in their premature period. This effect of 5-HT on cell proliferation were inhibited by ketanserin, a 5-HT{sub 2A} receptor specific antagonist. Moreover, bothmore » DOI-induced cell proliferation and phosphorylation of ERK1 and 2 proteins were inhibited by PD98059 and U0126, selective inhibitors of MEK in a concentration-dependent manner. Furthermore, treatment with fluoxetine, a 5-HT specific re-uptake inhibitor which inactivate the function of extracellular 5-HT, significantly increased the proliferative activities of MC3T3-E1 cells in a concentration-dependent manner. Our data indicate that 5-HT fill the role for proliferation of osteoblast cells in their premature period. Notably, 5-HT{sub 2A} receptor may be functionally expressed to regulate mechanisms underlying osteoblast cell proliferation, at least in part, through activation of ERK/MAPK pathways in MC3T3-E1 cells.« less

  10. Soluble and insoluble immune complexes activate human neutrophil NADPH oxidase by distinct Fc gamma receptor-specific mechanisms.

    PubMed

    Crockett-Torabi, E; Fantone, J C

    1990-11-01

    Signal transduction initiated by interaction of immune complexes (IC) with Fc gamma RII and Fc gamma RIII receptors on human neutrophils was studied by investigating the capacity of well-defined complexes to stimulate O2- generation in neutrophils. IC consisting of polyclonal rabbit antibody to human albumin were prepared at equivalence (insoluble complexes) and at five times Ag excess (soluble complexes). Stimulation of human neutrophils with soluble and insoluble IC caused a dose-dependent activation of the respiratory burst and O2- generation. Incubation of neutrophils with cytochalasin B significantly enhanced O2- generation in neutrophils stimulated with soluble IC. In contrast, cytochalasin B treatment had a minimal effect on O2- generation in neutrophils stimulated with insoluble IC. Treatment of neutrophils with PGE1 or pertussis toxin (PTx) significantly inhibited O2- generation by soluble IC-stimulated neutrophils. However, neither PGE1 nor PTx treatment significantly altered O2- generation in neutrophils stimulated with insoluble complexes. Although O2- generation induced by soluble IC was significantly inhibited by mAb against both Fc gamma RII and Fc gamma RIII receptor, insoluble IC stimulation of neutrophil O2- generation was significantly diminished only by mAb against Fc gamma RIII receptor. Cross-linking of either Fc gamma RII or Fc gamma RIII receptors on neutrophil surfaces induced O2- generation, and this activation was inhibited by both PGE1 and PTx treatment. These findings indicate that soluble and insoluble ICs induce O2- production in human neutrophils through distinct mechanisms. Soluble IC induce activation of neutrophils through a PTx- and PGE1-sensitive pathway that is dependent upon both Fc gamma RII and Fc gamma RIII receptors. Although insoluble IC induce O2- production through a PTx and PGE1 insensitive pathway mediated primarily through Fc gamma RIII receptor.

  11. Enhancement of antineoplastic effect and attenuation of sister chromatid exchanges by prostaglandin E2 in Ehrlich ascites tumour cells treated with cyclophosphamide in vivo.

    PubMed

    Mourelatos, D; Kritsi, Z; Mioglou, E; Dozi-Vassiliades, J

    1993-09-01

    Reduced sister chromatid exchanges (SCE) frequency in response to cyclophosphamide (CP) was observed when Ehrlich ascites tumour (EAT) cells were exposed in vivo to 2 micrograms/g body weight of prostaglandin E2 (PGE2). 1 h before i.p. injection of 5-bromodeoxyuridine (BrdUrd) adsorbed to activated charcoal, EAT-bearing mice treated i.p. with CP appeared to have increased SCE rates and cell division delays. PGE2 had no effect on survival and in inhibiting tumour growth. CP had only a slight non-significant effect on survival and in inhibiting tumour growth. In mice treated with the combined CP (5 micrograms/g bd wt) plus PGE2 (2 micrograms/g bd wt) a significant enhancement (P < 0.01) of survival time was accompanied by inhibition of tumour growth (P < 0.01) in comparison with the untreated controls. These data imply that SCEs might result from errors in a repair process which might involve a PGE2 sensitive step.

  12. Protective effect of lafutidine, a histamine H2 receptor antagonist, against loxoprofen-induced small intestinal lesions in rats.

    PubMed

    Amagase, Kikuko; Ochi, Akimu; Sugihara, Tetsuya; Kato, Shinichi; Takeuchi, Koji

    2010-05-01

    We examined the effect of lafutidine, a histamine H(2) receptor antagonist with a mucosal protective action mediated by capsaicin-sensitive sensory neurons (CSN), on intestinal lesions produced by loxoprofen administration in rats. Animals were given loxoprofen (10-100 mg/kg p.o.) and killed 24 h later. Lafutidine (10 and 30 mg/kg), cimetidine (100 mg/kg) or famotidine (30 mg/kg) was given twice p.o. at 0.5 h before and 6 h after loxoprofen. Omeprazole (100 mg/kg) was given p.o. once 0.5 h before. Ampicillin (800 mg/kg) was given p.o. twice at 24 h and 0.5 h before loxoprofen, while 16,16-dimethyl prostaglandin E(2) (dmPGE(2); 0.01 mg/kg) was given i.v. twice at 5 min before and 6 h after. Loxoprofen dose-dependently produced hemorrhagic lesions in the small intestine, accompanied by invasion of enterobacteria and increased inducible nitric oxide synthase (iNOS) expression as well as myeloperoxidase activity in the mucosa. The ulcerogenic response to loxoprofen (60 mg/kg) was significantly prevented by lafutidine (30 mg/kg), similar to dmPGE(2) and ampicillin, and the effect of lafutidine was totally attenuated by ablation of CSN. Neither cimetidine, famotidine nor omeprazole had a significant effect against these lesions. Lafutidine alone increased mucus secretion and reverted the decreased mucus response to loxoprofen, resulting in suppression of bacterial invasion and iNOS expression. In addition, loxoprofen downregulated Muc2 expression, and this response was totally reversed by lafutidine mediated by CSN. Lafutidine protects the small intestine against loxoprofen-induced lesions, essentially mediated by the CSN, and this effect may be functionally associated with increased Muc2 expression/mucus secretion, an important factor in the suppression of bacterial invasion.

  13. Naturally occurring glucagon-like peptide-2 (GLP-2) receptors in human intestinal cell lines.

    PubMed

    Sams, Anette; Hastrup, Sven; Andersen, Marie; Thim, Lars

    2006-02-17

    Although clinical trials with GLP-2 receptor agonists are currently ongoing, the mechanisms behind GLP-2-induced intestinal epithelial growth remain to be understood. To approach the GLP-2 mechanism of action this study aimed to identify intestinal cell lines endogenously expressing the GLP-2 receptor. Here we report the first identification of a cell line endogenously expressing functional GLP-2 receptors. The human intestinal epithelial cell line, FHC, expressed GLP-2 receptor encoding mRNA (RT-PCR) and GLP-2 receptor protein (Western blot). In cultured FHC cells, GLP-2 induced concentration dependent cAMP accumulation (pEC(50)=9.7+/-0.04 (mean+/-S.E.M., n=4)). In addition, a naturally occurring human intestinal fibroblast cell line, 18Co, endogenously expressing GLP-2 receptor encoding mRNA (RT-PCR) and protein (Western blot) was identified. No receptor functionality (binding or G-protein signalling) could be demonstrated in 18Co cells. The identified gut-relevant cell lines provide tools for future clarification of the mechanisms underlying GLP-2-induced epithelial growth.

  14. Microsomal Prostaglandin E2 Synthase-1 Modulates the Response to Vascular Injury

    PubMed Central

    Wang, Miao; Ihida-Stansbury, Kaori; Kothapalli, Devashish; Tamby, Mathieu C.; Yu, Zhou; Chen, Lihong; Grant, Gregory; Cheng, Yan; Lawson, John A.; Assoian, Richard K.; Jones, Peter L.; FitzGerald, Garret A.

    2013-01-01

    Background Microsomal (m) prostaglandin (PG) E2 synthase (S)-1 catalyzes the formation of PGE2 from PGH2, a cyclooxygenase (COX) product that is derived from arachidonic acid. Previous studies in mice suggest that targeting mPGES-1 may be less likely to cause hypertension or thrombosis than COX-2 selective inhibition or deletion in vivo. Indeed, deletion of mPGES-1 retards atherogenesis and angiotensin II-induced aortic aneurysm formation. The role of mPGES-1 in the response to vascular injury is unknown. Methods and Results Mice were subjected to wire injury of the femoral artery. Both neointimal area and vascular stenosis were reduced significantly four weeks after injury in mPGES-1 knock out (KO) mice compared to wild type (WT) controls (65.6±5.7 vs 37.7±5.1×103 pixel area and 70.5±13.4% vs 47.7±17.4%, respectively; p < 0.01). Induction of tenascin C (TN-C) after injury, a pro-proliferative and promigratory extracellular matrix protein, was attenuated in the KOs. Consistent with in vivo rediversion of PG biosynthesis, mPGES-1 deleted vascular smooth muscle cells (VSMC) generated less PGE2, but more PGI2 and expressed reduced TN-C when compared with WT cells. Both suppression of PGE2 and augmentation of PGI2 attenuate TN-C expression, VSMC proliferation and migration in vitro. Conclusions Deletion of mPGES-1 in mice attenuates neointimal hyperplasia after vascular injury, in part by regulating TN-C expression. This raises for consideration the therapeutic potential of mPGES-1 inhibitors as adjuvant therapy for percutaneous coronary intervention. PMID:21282500

  15. Involvement of the anion exchanger SLC26A6 in prostaglandin E2- but not forskolin-stimulated duodenal HCO3- secretion.

    PubMed

    Tuo, Biguang; Riederer, Brigitte; Wang, Zhaohui; Colledge, William H; Soleimani, Manoocher; Seidler, Ursula

    2006-02-01

    SLC26A6 is a recently identified apical Cl(-)/HCO(3)(-) exchanger with strong expression in murine duodenum. The present study was designed to examine the role of SLC26A6 in prostaglandin E(2) (PGE(2))-, forskolin-, and carbachol-induced duodenal HCO(3)(-) secretion. Murine duodenal mucosal HCO(3)(-) secretion was examined in vitro in Ussing chambers and mucosal SLC26A6 expression levels were analyzed by semiquantitative reverse-transcription polymerase chain reaction. Basal HCO(3)(-) secretion was diminished by 20%, PGE(2)-stimulated HCO(3)(-) secretory response by 59%, and carbachol-stimulated response was reduced by 35% in SLC26A6-/- compared with +/+ duodenal mucosa, whereas the forskolin-stimulated HCO(3)(-) secretory response was not different. In Cl(-)-free solutions, PGE(2)- and carbachol-stimulated HCO(3)(-) secretion was reduced by 81% and 44%, respectively, whereas forskolin-stimulated HCO(3)(-) secretion was not altered significantly. PGE(2) and carbachol, but not forskolin, were able to elicit a Cl(-)-dependent HCO(3)(-) secretory response in the absence of short-circuit current changes in cystic fibrosis transmembrane conductance regulator knockout mice. In murine duodenum, PGE(2)-mediated HCO(3)(-) secretion is strongly SLC26A6 dependent and cystic fibrosis transmembrane conductance regulator independent, whereas forskolin-stimulated HCO(3)(-) secretion is completely SLC26A6 independent and cystic fibrosis transmembrane conductance regulator dependent. Carbachol-induced secretion is less pronounced, but occurs via both transport pathways. This suggests that PGE(2) and forskolin activate distinct HCO(3)(-) transport pathways in the murine duodenum.

  16. Clinical evaluation of endocervical prostaglandin E2-triacetin-gel for preinduction cervical softening in pregnant women at term.

    PubMed

    Kieback, D G; Zahradnik, H P; Quaas, L; Kröner-Fehmel, E E; Lippert, T H

    1986-07-01

    In an open randomized clinical trial 100 pregnant women with low Bishop Scores at term were treated either with intracervical Prostaglandin (PG) E2 (0.5 mg in 2.5 ml triacetin-gel) 12 hours before labor induction with intravenous oxytocin or with oxytocin infusion alone. In 46 of the 50 pretreated patients (92%) the Bishop Score progressed at least 3 points, in four cases only 2 points. The mean Bishop score in the untreated patients increased insignificantly. After PGE2-gel administration 16 patients delivered during the 12 hour interval compared to 3 in the group without pretreatment. The first induction attempt was successful in 14 (64%) of the 22 patients that were left to be induced after cervical softening and in 26 (57%) of the 47 women without cervical priming. The Cesarean section rate was 10% (n = 5) in the PGE2-gel group and 12% (n = 6) in the control group. Dosage of oxytocin required for labor induction was significantly lower after cervical softening. No serious fetal or maternal side effects were observed after PGE2 pretreatment.

  17. The expression of TRPV channels, prostaglandin E2 and pro-inflammatory cytokines during behavioural fever in fish.

    PubMed

    Boltana, Sebastian; Sanhueza, Nataly; Donoso, Andrea; Aguilar, Andrea; Crespo, Diego; Vergara, Daniela; Arriagada, Gabriel; Morales-Lange, Byron; Mercado, Luis; Rey, Sonia; Tort, Lluis; Mackenzie, Simon

    2018-03-21

    A fever, or increased body temperature, is a symptom of inflammation, which is a complex defence reaction of the organism to pathogenic infections. After pathogens enter the body, immune cells secrete a number of agents, the functions of which stimulate the body to develop a functional immune and fever response. In mammals it is known that PGE 2 is the principal mediator of fever. The extent to which PGE 2 and other pro-inflammatory cytokines such as TNF-α, IL-6, or IL-1β could be involved in the induction of behavioural fever in fish remains to be clarified. Several members of the transient receptor potential (TRP) family of ion channels have been implicated as transducers of thermal stimuli, including TRPV1 and TRPV2, which are activated by heat. Here we show that members of the TRP family, TRPV1 and TRPV4, may participate in the coordination of temperature sensing during the behavioural fever. To examine the behavioral fever mechanism in Salmo salar an infection with IPNV, infectious pancreatic necrosis virus, was carried out by an immersion challenge with 10 × 10 5 PFU/mL -1 of IPNV. Behavioural fever impacted upon the expression levels of both TRPV1 and TRPV4 mRNAs after the viral challenge and revealed a juxtaposed regulation of TRPV channels. Our results suggest that an increase in the mRNA abundance of TRPV1 is tightly correlated with a significant elevation in the expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and PGE 2 ) in the Pre-Optic Area (POA) and cytokine release in plasma. Together, these data indicate that the reduction of TRPV4 expression during behavioural fever may contribute to the onset of behavioural fever influencing movement toward higher water temperatures. Our data also suggest an effect of TRPV channels in the regulation of behavioural fever through activation of EP3 receptors in the central nervous system by PGE 2 induced by plasma-borne cytokines. These results highlight for first time in mobile ectotherms the

  18. A2A-D2 receptor-receptor interaction modulates gliotransmitter release from striatal astrocyte processes.

    PubMed

    Cervetto, Chiara; Venturini, Arianna; Passalacqua, Mario; Guidolin, Diego; Genedani, Susanna; Fuxe, Kjell; Borroto-Esquela, Dasiel O; Cortelli, Pietro; Woods, Amina; Maura, Guido; Marcoli, Manuela; Agnati, Luigi F

    2017-01-01

    Evidence for striatal A2A-D2 heterodimers has led to a new perspective on molecular mechanisms involved in schizophrenia and Parkinson's disease. Despite the increasing recognition of astrocytes' participation in neuropsychiatric disease vulnerability, involvement of striatal astrocytes in A2A and D2 receptor signal transmission has never been explored. Here, we investigated the presence of D2 and A2A receptors in isolated astrocyte processes prepared from adult rat striatum by confocal imaging; the effects of receptor activation were measured on the 4-aminopyridine-evoked release of glutamate from the processes. Confocal analysis showed that A2A and D2 receptors were co-expressed on the same astrocyte processes. Evidence for A2A-D2 receptor-receptor interactions was obtained by measuring the release of the gliotransmitter glutamate: D2 receptors inhibited the glutamate release, while activation of A2A receptors, per se ineffective, abolished the effect of D2 receptor activation. The synthetic D2 peptide VLRRRRKRVN corresponding to the receptor region involved in electrostatic interaction underlying A2A-D2 heteromerization abolished the ability of the A2A receptor to antagonize the D2 receptor-mediated effect. Together, the findings are consistent with heteromerization of native striatal astrocytic A2A-D2 receptors that via allosteric receptor-receptor interactions could play a role in the control of striatal glutamatergic transmission. These new findings suggest possible new pathogenic mechanisms and/or therapeutic approaches to neuropsychiatric disorders. © 2016 International Society for Neurochemistry.

  19. Inhibitory effect of fermented Arctium lappa fruit extract on the IgE-mediated allergic response in RBL‑2H3 cells.

    PubMed

    Yoo, Jae-Myung; Yang, Ju Hye; Yang, Hye Jin; Cho, Won-Kyung; Ma, Jin Yeul

    2016-02-01

    Arctium lappa fruit has been used in traditional medicine, and it is known to exert beneficial effects, such as antioxidant, anti-inflammatory and anticancer effects. However, the effects of the Arctium lappa fruit on the allergic response remain unknown. In this study, we evaluated the anti-allergic effects of Arctium lappa fruit extract (AFE) and its fermented form (F-AFE) using immunoglobulin E (IgE)-activated RBL‑2H3 cells. To investigate the anti-allergic effects of AFE or F-AFE, we examined the release of β-hexosaminidase, a key biomarker of degranulation during an allergic reaction, and the production of pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) in the cells treated with or without the above-mentioned extracts. AFE weakly inhibited the release of β-hexosaminidase, whereas F-AFE significantly suppressed the release of β-hexosaminidase in a dose-dependent manner. Consistently, F-AFE suppressed the production of TNF-α and PGE2 in a dose-dependent manner. F-AFE exerted an inhibitory effect on the production of β-hexosaminidase, TNF-α and PGE2 with an IC50 value of 30.73, 46.96 and 36.27 µg/ml, respectively. Furthermore, F-AFE inhibited the phosphorylation of Lyn, Fyn and Syk, which are involved in the FcεRI signaling pathway, that of phosphoinositide phospholipase C (PLC)γ1/2 and protein kinase C (PKC)δ, which are associated with the degranulation process, as well as that of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK), p38 and Akt, which are associated with cytokine expression. In the late phase, F-AFE partially suppressed the phosphorylation of cytosolic phospholipase A2 (cPLA2), but not the expression of cyclooxygenase (COX)-2. To compare and identify the major components of the two extracts, we used high-performance liquid chromatography. The levels of arctigenin, one of the major compounds, were elevated 6-fold in F-AFE compared with AFE, whereas the

  20. The effects of a cytokine suppressive anti-inflammatory drug on the output of prostaglandin E(2) and interleukin-1 beta from human fetal membranes.

    PubMed

    Sullivan, M H F; Alvi, S A; Brown, N L; Elder, M G; Bennett, P R

    2002-03-01

    Fetal membranes are a primary source of prostaglandins and pro-inflammatory cytokines implicated in human parturition, so the inhibition of inflammatory pathways may be of benefit in pregnancies complicated by premature labour. We have therefore investigated the effects of a cytokine-suppressant anti-inflammatory drug (CSAID) on the output of prostaglandin E(2) (PGE(2)) and interleukin (IL)-1 beta from human fetal membranes in vitro. Bacterial endotoxin increased the expression of mRNA for IL-1 beta and type-2 cyclo-oxygenase (COX-2), and there were corresponding increases in the output of IL-1 beta protein and PGE(2). The CSAID decreased IL-1 beta protein, COX-2 expression and PGE(2) output, but not mRNA for IL-1 beta, indicating a post-translational effect on the production of IL-1 beta and a transcriptional affect on COX-2, with an overall reduction in PGE(2). These findings are consistent with the effects of CSAIDs in other systems, and indicate that they are of possible use in premature labour.

  1. Purine ionotropic (P2X) receptors.

    PubMed

    Köles, L; Fürst, S; Illes, P

    2007-01-01

    Purinergic signaling is involved in the proper functioning of virtually all organs of the body. Although in some cases purines have a major influence on physiological functions (e.g. thrombocyte aggregation), more often they are just background modulators contributing to fine tuning of biological events. However, under pathological conditions, when a huge amount of adenosine 5'-triphosphate (ATP) can reach the extracellular space, their significance is increasing. ATP and its various degradation products activate membrane receptors divided into two main classes: the metabotropic P2Y and the ionotropic P2X family. This latter group, the purine ionotropic receptor, is the object of this review. After providing a description about the distribution and functional properties of P2X receptors in the body, their pharmacology will be summarized. In the second part of this review, the role of purines in those organ systems and body functions will be highlighted, where the (patho)physiological role of P2X receptors has been suggested or is even well established. Besides the regulation of organ systems, for instance in the cardiovascular, respiratory, genitourinary or gastrointestinal system, some special issues will also be discussed, such as the role of P2X receptors in pain, tumors, central nervous system (CNS) injury and embryonic development. Several examples will indicate that purine ionotropic receptors might serve as attractive targets for pharmacological interventions in various diseases, and that selective ligands for these receptors will probably constitute important future therapeutic tools in humans.

  2. Cocaine Inhibits Dopamine D2 Receptor Signaling via Sigma-1-D2 Receptor Heteromers

    PubMed Central

    Navarro, Gemma; Moreno, Estefania; Bonaventura, Jordi; Brugarolas, Marc; Farré, Daniel; Aguinaga, David; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carmen; Ferre, Sergi

    2013-01-01

    Under normal conditions the brain maintains a delicate balance between inputs of reward seeking controlled by neurons containing the D1-like family of dopamine receptors and inputs of aversion coming from neurons containing the D2-like family of dopamine receptors. Cocaine is able to subvert these balanced inputs by altering the cell signaling of these two pathways such that D1 reward seeking pathway dominates. Here, we provide an explanation at the cellular and biochemical level how cocaine may achieve this. Exploring the effect of cocaine on dopamine D2 receptors function, we present evidence of σ1 receptor molecular and functional interaction with dopamine D2 receptors. Using biophysical, biochemical, and cell biology approaches, we discovered that D2 receptors (the long isoform of the D2 receptor) can complex with σ1 receptors, a result that is specific to D2 receptors, as D3 and D4 receptors did not form heteromers. We demonstrate that the σ1-D2 receptor heteromers consist of higher order oligomers, are found in mouse striatum and that cocaine, by binding to σ1 -D2 receptor heteromers, inhibits downstream signaling in both cultured cells and in mouse striatum. In contrast, in striatum from σ1 knockout animals these complexes are not found and this inhibition is not seen. Taken together, these data illuminate the mechanism by which the initial exposure to cocaine can inhibit signaling via D2 receptor containing neurons, destabilizing the delicate signaling balance influencing drug seeking that emanates from the D1 and D2 receptor containing neurons in the brain. PMID:23637801

  3. Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Induces Prostaglandin E2 Production through Cyclooxygenase 1, Which Is Dependent on the ERK1/2-p-C/EBP-β Pathway

    PubMed Central

    Bi, Yanmin; Guo, Xue-kun; Zhao, Haiyan; Gao, Li; Wang, Lianghai; Tang, Jun

    2014-01-01

    ABSTRACT Atypical porcine reproductive and respiratory syndrome (PRRS) caused by highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever and high mortality. However, the mechanism underlying the fever induction is still unknown. Prostaglandin E2 (PGE2), synthesized by cyclooxygenase type 1/2 (COX-1/2) enzymes, is essential for inducing fever. In this study, we found that PGE2, together with COX-1, was significantly elevated by HP-PRRSV. We subsequently demonstrated that extracellular signal-regulated kinase 1/2 (ERK1/2) and phosphorylated ERK (p-ERK) were the key nodes to trigger COX-1 expression after HP-PRRSV infection. Furthermore, we proved the direct binding of p-C/EBP-β to the COX-1 promoter by luciferase reporter and chromatin immunoprecipitation assays. In addition, silencing of C/EBP-β remarkably impaired the enhancement of COX-1 production induced by HP-PRRSV infection. Taken together, our results indicate that HP-PPRSV elicits the expression of COX-1 through the ERK1/2-p-C/EBP-β signaling pathway, resulting in the increase of PGE2, which might be the cause of high fever in infected pigs. Our findings might provide new insights into the molecular mechanisms underlying the pathogenesis of HP-PRRSV infection. IMPORTANCE The atypical PRRS caused by HP-PRRSV was characterized by high fever, high morbidity, and high mortality in pigs of all ages, yet how HP-PRRSV induces high fever in pigs remains unknown. In the present study, we found out that HP-PRRSV infection could increase PGE2 production by upregulation of COX-1, and we subsequently characterized the underlying mechanisms about how HP-PRRSV enhances COX-1 production. PGE2 plays a critical role in inducing high temperature in hosts during pathogen infections. Thus, our findings here could help us have a better understanding of HP-PRRSV pathogenesis. PMID:24352469

  4. Hypothyroidism Affects D2 Receptor-mediated Breathing without altering D2 Receptor Expression

    PubMed Central

    Schlenker, Evelyn H.; Rio, Rodrigo Del; Schultz, Harold D.

    2015-01-01

    Bromocriptine depressed ventilation in air and D2 receptor expression in the nucleus tractus solitaries (NTS) in male hypothyroid hamsters. Here we postulated that in age- matched hypothyroid female hamsters, the pattern of D2 receptor modulation of breathing and D2 receptor expression would differ from those reported in hypothyroid males. In females hypothyroidism did not affect D2 receptor protein levels in the NTS, carotid bodies or striatum. Bromocriptine, but not carmoxirole (a peripheral D2 receptor agonist), increased oxygen consumption and body temperature in awake air-exposed hypothyroid female hamsters and stimulated their ventilation before and following exposure to hypoxia. Carmoxirole depressed frequency of breathing in euthyroid hamsters prior to, during and following hypoxia exposures and stimulated it in the hypothyroid hamsters following hypoxia. Although hypothyroidism did not affect expression of D2 receptors, it influenced central D2 modulation of breathing in a disparate manner relative to euthyroid hamsters. PMID:24434437

  5. Hypothyroidism affects D2 receptor-mediated breathing without altering D2 receptor expression.

    PubMed

    Schlenker, Evelyn H; Del Rio, Rodrigo; Schultz, Harold D

    2014-03-01

    Bromocriptine depressed ventilation in air and D2 receptor expression in the nucleus tractus solitaries (NTS) in male hypothyroid hamsters. Here we postulated that in age-matched hypothyroid female hamsters, the pattern of D2 receptor modulation of breathing and D2 receptor expression would differ from those reported in hypothyroid males. In females hypothyroidism did not affect D2 receptor protein levels in the NTS, carotid bodies or striatum. Bromocriptine, but not carmoxirole (a peripheral D2 receptor agonist), increased oxygen consumption and body temperature in awake air-exposed hypothyroid female hamsters and stimulated their ventilation before and following exposure to hypoxia. Carmoxirole depressed frequency of breathing in euthyroid hamsters prior to, during and following hypoxia exposures and stimulated it in the hypothyroid hamsters following hypoxia. Although hypothyroidism did not affect expression of D2 receptors, it influenced central D2 modulation of breathing in a disparate manner relative to euthyroid hamsters. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. [Role of central alpha-adrenoreceptors in the mechanism of the hyperthermic action of prostaglandin E2].

    PubMed

    Gurin, V N; Vismont, F I; Tsariuk, V V

    1984-01-01

    It has been demonstrated in rat experiments that the central action of PGE2 results in body temperature rise associated with a reduction in the functional activity of hypothalamic adrenergic systems. In contrast to PGE2 and the beta-adrenomimetic isoproterenol, the alpha-adrenomimetics noradrenaline, mezaton and clonidine were shown to lower body temperature. In the rabbit, clonidine and PGE2 were found to have opposing effects on the neuronal activity of the anterior hypothalamus.

  7. PG&E's Seismic Network Goes Digital With Strong Motion: Successes and Challenges

    NASA Astrophysics Data System (ADS)

    Stanton, M. A.; Cullen, J.; McLaren, M. K.

    2008-12-01

    Pacific Gas and Electric Company (PG&E) is in year 3 of a 5-year project to upgrade the Central Coast Seismic Network (CCSN) from analog to digital. Located along the south-central California coast, the CCSN began operation in 1987, with 20 analog stations; 15 vertical component and 5 dual gain 3-component S-13 sensors. The analog signals travel over FM radio telemetry links and voice channels via PG&E's microwave network to our facility in San Francisco (SF), where the A/D conversion is performed on a computer running Earthworm v7.1, which also transmits the data to the USGS in Menlo Park. At the conversion point the dynamic ranges of the vertical and dual-gain sensors are 40-50dB and 60-70dB, respectively. Dynamic range exceedance (data clipping) generally occurs for a M2.5 or greater event within about 40 km of a station. The motivations to upgrade the seismic network were the need for higher dynamic range and to retire obsolete analog transmission equipment. The upgraded digital stations consist of the existing velocity sensors, a 131A-02/3 accelerometer and a Reftek 130-01 Broadband Seismic Recorder for digital data recording and transmission to SF. Vertical only stations have one component of velocity and 3 components of acceleration. Dual gain sites have 3 components of velocity and 3 of acceleration. To date we have successfully upgraded 6 sites; 3 more will be installed by the end of 2008. Some of the advantages of going digital are 1) data is recorded at each site and in SF, 2) substantially increased dynamic range of the velocity sensors to 120dB, as observed by on scale, close-by recordings from a M3.9 San Simeon aftershock on 04/29/2008, 3) accelerometers for on scale recording of large earthquakes, and 4) ability to contribute our strong motion data to USGS ShakeMaps. A significant challenge has been consistent radio communications. To resolve this issue we are installing point-to-multipoint Motorola Canopy spread spectrum radios at the stations and

  8. Laparoscopic application of PGE2 to re-establish oviducal patency and fertility in infertile mares: a preliminary study.

    PubMed

    Allen, W R; Wilsher, S; Morris, L; Crowhurst, J S; Hillyer, M H; Neal, H N

    2006-09-01

    Mares are occasionally encountered that consistently fail to conceive when inseminated, naturally or artificially, with fertile stallion semen in the absence of any identifiable pathology of either the structure or function of their reproductive tract. Temporary blockage of the oviducts by accumulations of naturally occurring oviducal masses may be preventing oviducal transport of the embryo to the uterus. Mares, with known reproductive histories, that had exhibited inexplicable failure of conception were treated by laparoscopically guided administration of PGE2-laced triacetin gel directly onto the surface of their oviducts. Fifteen mares age 10-21 years that had exhibited inexplicable failure of conception during 1-4 years were treated, of which 14 (93%) conceived within the same or subsequent breeding season. The high success rate of this treatment supports the tentative diagnosis of oviducal obstruction in these mares and indicates that blockage of the mare's oviducts may occur in the form of a moveable accumulation of debris rather than from permanent fibrous adhesions resulting from salpingitis. This laparoscopic application of PGE2 to the oviducts constitutes a sound and practical method of restoring fertility in mares suffering oviducal obstruction and further studies involving the procedure are warranted.

  9. Anti-Inflammatory and Osteoprotective Effects of Cannabinoid-2 Receptor Agonist HU-308 in a Rat Model of Lipopolysaccharide-Induced Periodontitis.

    PubMed

    Ossola, Cesar A; Surkin, Pablo N; Mohn, Claudia E; Elverdin, Juan C; Fernández-Solari, Javier

    2016-06-01

    Anti-inflammatory and immunologic properties of cannabinoids have been reported in several tissues. Expression of cannabinoid receptor Type 2 was reported in osteoblasts and osteoclasts, suggesting a key role in bone metabolism. The aim of this study is to assess the effect of treatment with cannabinoid-2 receptor agonist HU-308 in the oral health of rats subjected to lipopolysaccharide (LPS)-induced periodontitis. Twenty-four rats were distributed in four groups (six rats per group): 1) control rats; 2) sham rats; 3) rats submitted to experimental periodontitis (LPS); and 4) rats submitted to experimental periodontitis and treated with HU-308 (LPS+HU). In groups LPS and LPS+HU, periodontitis was induced by LPS (1 mg/mL) injected into the gingival tissue (GT) of maxillary and mandibular first molars and into the interdental space between the first and second molars, 3 days per week for 6 weeks. In group LPS+HU, HU-308 (500 ng/mL) was applied topically to the GT daily. Alveolar bone loss resulting from LPS-induced periodontitis was significantly attenuated with HU-308 treatment (LPS+HU), measured by macroscopic and histologic examination. Treatment also reduced gingival production of inflammatory mediators augmented in LPS-injected rats, such as: 1) inducible nitric oxide (iNOS) activity (LPS: 90.18 ± 36.51 pmol/minute/mg protein versus LPS+HU: 16.37 ± 4.73 pmol/minute/mg protein; P <0.05); 2) tumor necrosis factor alpha (LPS: 185.70 ± 25.63 pg/mg protein versus LPS+HU: 95.89 ± 17.47 pg/mg protein; P <0.05); and 3) prostaglandin E2 (PGE2) (LPS: 159.20 ± 38.70 pg/mg wet weight versus LPS+HU: 71.25 ± 17.75 pg/mg wet weight; P <0.05). Additionally, HU-308 treatment prevented the inhibitory effect of LPS-induced periodontitis on the salivary secretory response to pilocarpine. Moreover, iNOS activity and PGE2 content, which were increased by LPS-induced periodontitis in the submandibular gland, returned to control values after HU-308 treatment. This study

  10. EV-077 in vitro inhibits platelet aggregation in type-2 diabetics on aspirin.

    PubMed

    Sakariassen, Kjell S; Femia, Eti A; Daray, Federico M; Podda, Gian M; Razzari, Cristina; Pugliano, Mariateresa; Errasti, Andrea E; Armesto, Arnaldo R; Nowak, Wanda; Alberts, Pēteris; Meyer, Jean-Philippe; Sorensen, Alexandra S; Cattaneo, Marco; Rothlin, Rodolfo P

    2012-11-01

    This study aimed to characterize the in vitro effect of EV-077, a compound that antagonises the binding of prostanoids and isoprostanes to the thromboxane receptor (TP) and inhibits the thromboxane synthase (TS), on platelet aggregation of patients with type-2 diabetes and coronary artery disease (CAD) on chronic aspirin treatment. The effect of EV-077 on 8-iso-PGE(2)-mediated TP receptor contraction of human arteries was also investigated. Fifty-two type-2 diabetics with CAD on chronic aspirin (100 mg) treatment were studied. Arachidonic acid-induced platelet aggregation was measured by impedance aggregometry in platelet-rich plasma (PRP) and whole blood anticoagulated with hirudin, and by light transmission aggregometry in citrate-anticoagulated PRP following 10-min in vitro exposure to EV-077 (100 nmol/l) or control. The effect of EV-077 was measured on isometric contraction of 24 human umbilical arteries induced by isoprostane 8-iso-PGE(2). Arachidonic acid (1 mmol/l) induced substantial aggregation in hirudin-anticoagulated whole blood (63 ± 4 AU), which was significantly reduced by in vitro exposure to EV-077 (38 ± 3 AU, P<0.001). Virtually no arachidonic acid-induced aggregation in citrate-anticoagulated or hirudin-anticoagulated PRP was observed. EV-077 potently, competitively and reversibly inhibited TP mediated contraction of umbilical arteries by 8-iso-PGE(2) (P<0.01). Aspirin did not completely inhibit arachidonic acid-induced platelet aggregation in whole blood from type-2 diabetics with CAD. This aggregation is likely induced by prostanoids and/or isoprostanes produced by leukocytes, because it was significantly reduced by EV-077. The TP receptor-mediated contraction of human arteries induced by isoprostane 8-iso-PGE(2) was effectively inhibited by EV-077. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Prostaglandin E2 Adds Bone to a Cancellous Bone Site with a Closed Growth Plate and Low Bone Turnover in Ovariectomized Rats

    NASA Technical Reports Server (NTRS)

    Ma, Y. F.; Ke, H. Z.; Jee, W. S. S.

    1994-01-01

    The objects of this study were to determine the responses of a cancellous bone site with a closed growth plate (the distal tibial metaphysis, DTM) to ovariectomy (OVX) and OVX plus a prostaglandin E2 (PGE2) treatment, and compare the site's response to previous findings reported for another site (the proximal tibial metaphysis, PTM). Thirty-five 3-month old female Sprague-Dawley rats were divided into five groups: basal, sham-OVX, and OVX+0, +1, or +6 mg PGE2/kg/d injected subcutaneously for 3 months and given double fluorescent labels before sacrifice. Cancellous bone histomorphometric analyses were performed on 20-micron-thick undecalcified DTM sections. Similar to the PTM, the DTM showed age-related decreases in bone formation and increases in bone resorption, but it differed in that at 3 months post-OVX; there was neither bone loss nor changes in formation endpoints. Giving 1 mg PGE2/kg/d to OVX rats prevented most age-related changes and maintained the bone formation histomorphometry near basal levels. Treating OVX rats with 6 mg PGE2/kg/d prevented age-related bone changes, added extra bone, and improved microanatomical structure by stimulating bone formation without altering bone resorption. Furthermore, after PGE2 administration, the DTM, a cancellous bone site with a closed growth plate, inereased bone formation more than did the cancellous bone in the PTM.

  12. Effects of pulpotomy using mineral trioxide aggregate on prostaglandin transporter and receptors in rat molars.

    PubMed

    Ohkura, Naoto; Edanami, Naoki; Takeuchi, Ryosuke; Tohma, Aiko; Ohkura, Mariko; Yoshiba, Nagako; Yoshiba, Kunihiko; Ida-Yonemochi, Hiroko; Ohshima, Hayato; Okiji, Takashi; Noiri, Yuichiro

    2017-07-31

    Mineral trioxide aggregate (MTA) is a commonly used dental pulp-capping material with known effects in promoting reparative dentinogenesis. However, the mechanism by which MTA induces dentine repair remains unclear. The aim of the present study was to investigate the role of prostaglandin E 2 (PGE 2 ) in dentine repair by examining the localisation and mRNA expression levels of its transporter (Pgt) and two of its receptors (Ep2 and Ep4) in a rat model of pulpotomy with MTA capping. Ep2 expression was detected in odontoblasts, endothelial cells, and nerve fibres in normal and pulpotomised tissues, whereas Pgt and Ep4 were immunolocalised only in the odontoblasts. Moreover, mRNA expression of Slco2a1 (encoding Pgt), Ptger2 (encoding Ep2), and Ptger4 (encoding Ep4) was significantly upregulated in pulpotomised dental pulp and trigeminal ganglia after MTA capping. Our results provide insights into the functions of PGE 2 via Pgt and Ep receptors in the healing dentine/pulp complex and may be helpful in developing new therapeutic targets for dental disease.

  13. Receptor interaction profiles of novel N-2-methoxybenzyl (NBOMe) derivatives of 2,5-dimethoxy-substituted phenethylamines (2C drugs).

    PubMed

    Rickli, Anna; Luethi, Dino; Reinisch, Julian; Buchy, Danièle; Hoener, Marius C; Liechti, Matthias E

    2015-12-01

    N-2-methoxybenzyl-phenethylamines (NBOMe drugs) are newly used psychoactive substances with poorly defined pharmacological properties. The aim of the present study was to characterize the receptor binding profiles of a series of NBOMe drugs compared with their 2,5-dimethoxy-phenethylamine analogs (2C drugs) and lysergic acid diethylamide (LSD) in vitro. We investigated the binding affinities of 2C drugs (2C-B, 2C-C, 2C-D, 2C-E, 2C-H, 2C-I, 2C-N, 2C-P, 2C-T-2, 2C-T-4, 2C-T-7, and mescaline), their NBOMe analogs, and LSD at monoamine receptors and determined functional 5-hydroxytryptamine-2A (5-HT2A) and 5-HT2B receptor activation. Binding at and the inhibition of monoamine uptake transporters were also determined. Human cells that were transfected with the respective human receptors or transporters were used (with the exception of trace amine-associated receptor-1 [TAAR1], in which rat/mouse receptors were used). All of the compounds potently interacted with serotonergic 5-HT2A, 5-HT2B, 5-HT2C receptors and rat TAAR1 (most Ki and EC50: <1 μM). The N-2-methoxybenzyl substitution of 2C drugs increased the binding affinity at serotonergic 5-HT2A, 5-HT2C, adrenergic α1, dopaminergic D1-3, and histaminergic H1 receptors and monoamine transporters but reduced binding to 5-HT1A receptors and TAAR1. As a result, NBOMe drugs were very potent 5-HT2A receptor agonists (EC50: 0.04-0.5 μM) with high 5-HT2A/5-HT1A selectivity and affinity for adrenergic α1 receptors (Ki: 0.3-0.9 μM) and TAAR1 (Ki: 0.06-2.2 μM), similar to LSD, but not dopaminergic D1-3 receptors (most Ki:>1 μM), unlike LSD. The binding profile of NBOMe drugs predicts strong hallucinogenic effects, similar to LSD, but possibly more stimulant properties because of α1 receptor interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Direct pyrogenic input from prostaglandin EP3 receptor-expressing preoptic neurons to the dorsomedial hypothalamus

    PubMed Central

    Nakamura, Yoshiko; Nakamura, Kazuhiro; Matsumura, Kiyoshi; Kobayashi, Shigeo; Kaneko, Takeshi; Morrison, Shaun F.

    2008-01-01

    Fever is induced by the neuronal mechanism in the brain. Prostaglandin (PG) E2 acts as a pyrogenic mediator in the preoptic area (POA) probably through the EP3 subtype of PGE receptor expressed on GABAergic neurons, and this PGE2 action triggers neuronal pathways for sympathetic thermogenesis in peripheral effector organs including brown adipose tissue (BAT). To explore pyrogenic efferent pathways from the POA, we here determined projection targets of EP3 receptor-expressing POA neurons with a special focus on rat hypothalamic regions including the dorsomedial hypothalamic nucleus (DMH), which is known as a center for autonomic responses to stress. Among injections of cholera toxin b-subunit (CTb), a retrograde tracer, into hypothalamic regions at the rostrocaudal level of the DMH, injections into the DMH, lateral hypothalamic area (LH), and dorsal hypothalamic area (DH) resulted in EP3 receptor immunolabeling in substantial populations of CTb-labeled neurons in the POA. Bilateral microinjections of muscimol, a GABAA receptor agonist, into the DMH and a ventral region of the DH, but not those into the LH, inhibited thermogenic (BAT sympathetic nerve activity, BAT temperature, core body temperature, and expired CO2) and cardiovascular (arterial pressure and heart rate) responses to an intra-POA PGE2 microinjection. Further immunohistochemical observations revealed close association of POA-derived GABAergic axon swellings with DMH neurons projecting to the medullary raphe regions where sympathetic premotor neurons for febrile and thermoregulatory responses are localized. These results suggest that a direct projection of EP3 receptor-expressing POA neurons to the DMH/DH region mediates febrile responses via a GABAergic mechanism. PMID:16367780

  15. Mantle reservoirs (EM-1, OIB, E-MORB and N-MORB), long duration and polystages history for PGE-bearing paleoproterozoic layered intrusions in the N-E part of Fennoscandian Shield.

    NASA Astrophysics Data System (ADS)

    Bayanova, Tamara; Nerovich, Ludmila; Serov, Pavel; Kunakkuzin, Evgeniy; Elizarov, Dmitriy

    2015-04-01

    Paleoproterozoic layered PGE -bearing intrusions located in the N-E part of the Fennoscandian Shield and have a total are about 2000 km2. Long multidisciplinary studies using isotope Nd-Sr, U-Pb and 3He/4He systematics permit create a big bank of geochemistry data for different part of the intrusions: barren and main Cu-Ni-Cr-Ti-V and PGE phases, dykes complexes and host rocks. Based on U-Pb isotope data (on baddeleyite and zircon) and Sm-Nd mineral isochrones (on rock-forming and sulphides minerals) there is distinguished long magmatic duration from 2.53 to 2.40 Ga. Using precise U-Pb and Sm-Nd data for different part of the intrusions there are established four main impulses: 2.53, 2.50, 2.45, and 2.40 Ga of magmatic (LIP) activities for gabbronorite, anothosite et.set. rocks. The primary reservoir for all precious and multimetal massifs are considered as enriched mantle EM-1 using ɛNd- ISr system with negative ɛNd values and low ISr data for whole rocks of the intrusions. Dyke complexes are presented as three groups: high Ti-ferrodolerites, low Ti and low Fe-gabbronorites. Complex isotope (U-Pb, Sm-Nd) and geochemistry (REE, ɛNd, ISr) data investigations reflect OIB, E-MORB and N-MORB reservoirs for its origin (Nerovich et all., 2014). Isotope 3He/4He and 3He concentrations for accessory minerals ( ilmenite, magnetite et. set ) from the layered paleoproterozoic intrusions reflect significant lower mantle component and upper mantle contribution. According to the model of binary mixing (Jahn et all, 2000) there were calculated mantle and core component into plume magmatic reservoir connected with the origin of the PGE paleoproterozoic intrusions. The mantle contributions lie in the interval from 85 to 93% and core component are very less. All investigations are devoted to memory of academician RAS, professor F.Mitrofanov (Russia), he was a leader of scientific school for geology, geochemistry and metallogenesis of ore deposits. The studies are

  16. Ciproxifan, a histamine H{sub 3} receptor antagonist and inverse agonist, presynaptically inhibits glutamate release in rat hippocampus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, Cheng-Wei; Lin, Tzu-Yu

    2017-03-15

    Ciproxifan is an H{sub 3} receptor antagonist and inverse agonist with antipsychotic effects in several preclinical models; its effect on glutamate release has been investigated in the rat hippocampus. In a synaptosomal preparation, ciproxifan reduced 4-aminopyridine (4-AP)-evoked Ca{sup 2+}-dependent glutamate release and cytosolic Ca{sup 2+} concentration elevation but did not affect the membrane potential. The inhibitory effect of ciproxifan on 4-AP-evoked glutamate release was prevented by the Gi/Go-protein inhibitor pertussis toxin and Ca{sub v}2.2 (N-type) and Ca{sub v}2.1 (P/Q-type) channel blocker ω-conotoxin MVIIC, but was not affected by the intracellular Ca{sup 2+}-release inhibitors dantrolene and CGP37157. Furthermore, the phospholipase A{submore » 2} (PLA{sub 2}) inhibitor OBAA, prostaglandin E{sub 2} (PGE{sub 2}), PGE2 subtype 2 (EP{sub 2}) receptor antagonist PF04418948, and extracellular signal-regulated kinase (ERK) inhibitor FR180204 eliminated the inhibitory effect of ciproxifan on glutamate release. Ciproxifan reduced the 4-AP-evoked phosphorylation of ERK and synapsin I, a presynaptic target of ERK. The ciproxifan-mediated inhibition of glutamate release was prevented in synaptosomes from synapsin I-deficient mice. Moreover, ciproxifan reduced the frequency of miniature excitatory postsynaptic currents without affecting their amplitude in hippocampal slices. Our data suggest that ciproxifan, acting through the blockade of Gi/Go protein-coupled H{sub 3} receptors present on hippocampal nerve terminals, reduces voltage-dependent Ca{sup 2+} entry by diminishing PLA{sub 2}/PGE{sub 2}/EP{sub 2} receptor pathway, which subsequently suppresses the ERK/synapsin I cascade to decrease the evoked glutamate release. - Highlights: • Ciproxifan presynaptically reduces glutamate release in the hippocampus in vitro. • Decrease in voltage-dependent Ca{sup 2+} influx is involved. • A role for the PLA{sub 2}/PGE{sub 2}/EP{sub 2} pathway in the action of

  17. P2Y2 Receptor and EGFR Cooperate to Promote Prostate Cancer Cell Invasion via ERK1/2 Pathway.

    PubMed

    Li, Wei-Hua; Qiu, Ying; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2015-01-01

    As one member of G protein-coupled P2Y receptors, P2Y2 receptor can be equally activated by extracellular ATP and UTP. Our previous studies have proved that activation of P2Y2 receptor by extracellular ATP could promote prostate cancer cell invasion and metastasis in vitro and in vivo via regulating the expressions of some epithelial-mesenchymal transition/invasion-related genes (including IL-8, E-cadherin, Snail and Claudin-1), and the most significant change in expression of IL-8 was observed after P2Y2 receptor activation. However, the signaling pathway downstream of P2Y2 receptor and the role of IL-8 in P2Y2-mediated prostate cancer cell invasion remain unclear. Here, we found that extracellular ATP/UTP induced activation of EGFR and ERK1/2. After knockdown of P2Y2 receptor, the ATP -stimulated phosphorylation of EGFR and ERK1/2 was significantly suppressed. Further experiments showed that inactivation of EGFR and ERK1/2 attenuated ATP-induced invasion and migration, and suppressed ATP-mediated IL-8 production. In addition, knockdown of IL-8 inhibited ATP-mediated invasion and migration of prostate cancer cells. These findings suggest that P2Y2 receptor and EGFR cooperate to upregulate IL-8 production via ERK1/2 pathway, thereby promoting prostate cancer cell invasion and migration. Thus blocking of the P2Y2-EGFR-ERK1/2 pathway may provide effective therapeutic interventions for prostate cancer.

  18. Novel Roles for Hypoxia and Prostaglandin E2 in the Regulation of IL-8 During Endometrial Repair

    PubMed Central

    Maybin, Jacqueline A.; Hirani, Nikhil; Jabbour, Henry N.; Critchley, Hilary O.D.

    2011-01-01

    The endometrium has a remarkable capacity for efficient repair; however, factors involved remain undefined. Premenstrual progesterone withdrawal leads to increased prostaglandin (PG) production and local hypoxia. Here we determined human endometrial expression of interleukin-8 (IL-8) and the roles of PGE2 and hypoxia in its regulation. Endometrial biopsy specimens (n = 51) were collected. Endometrial cells and explants were exposed to 100 nmol/L of PGE2 or 0.5% O2. The endometrial IL-8 concentration peaked during menstruation (P < 0.001) and had a significant proangiogenic effect. IL-8 was increased by PGE2 and hypoxia in secretory but not proliferative explants, which suggests that exposure to progesterone is essential. In vitro progesterone withdrawal induced significant IL-8 up-regulation in proliferative explants primed with progestins, but only in the presence of hypoxia. Epithelial cells treated simultaneously with PGE2 and hypoxia demonstrated synergistic increases in IL-8. Inhibition of HIF-1 by short hairpin RNA abolished hypoxic IL-8 induction, and inhibition of NF-κB by an adenoviral dominant negative inhibitor decreased PGE2-induced IL-8 expression (P > 0.05). Increased menstrual IL-8 is consistent with a role in repair. Progesterone withdrawal, hypoxia, and PGE2 regulate endometrial IL-8 by acting via HIF-1 and NF-κB. Hence, progesterone withdrawal may activate two distinct pathways to initiate endometrial repair. PMID:21356375

  19. Biomechanical forces promote blood development through prostaglandin E2 and the cAMP–PKA signaling axis

    PubMed Central

    Diaz, Miguel F.; Li, Nan; Lee, Hyun Jung; Adamo, Luigi; Evans, Siobahn M.; Willey, Hannah E.; Arora, Natasha; Torisawa, Yu-suke; Vickers, Dwayne A.; Morris, Samantha A.; Naveiras, Olaia; Murthy, Shashi K.; Ingber, Donald E.

    2015-01-01

    Blood flow promotes emergence of definitive hematopoietic stem cells (HSCs) in the developing embryo, yet the signals generated by hemodynamic forces that influence hematopoietic potential remain poorly defined. Here we show that fluid shear stress endows long-term multilineage engraftment potential upon early hematopoietic tissues at embryonic day 9.5, an embryonic stage not previously described to harbor HSCs. Effects on hematopoiesis are mediated in part by a cascade downstream of wall shear stress that involves calcium efflux and stimulation of the prostaglandin E2 (PGE2)–cyclic adenosine monophosphate (cAMP)–protein kinase A (PKA) signaling axis. Blockade of the PGE2–cAMP–PKA pathway in the aorta-gonad-mesonephros (AGM) abolished enhancement in hematopoietic activity. Furthermore, Ncx1 heartbeat mutants, as well as static cultures of AGM, exhibit lower levels of expression of prostaglandin synthases and reduced phosphorylation of the cAMP response element–binding protein (CREB). Similar to flow-exposed cultures, transient treatment of AGM with the synthetic analogue 16,16-dimethyl-PGE2 stimulates more robust engraftment of adult recipients and greater lymphoid reconstitution. These data provide one mechanism by which biomechanical forces induced by blood flow modulate hematopoietic potential. PMID:25870199

  20. Analysis of tandem E-box motifs within human Complement receptor 2 (CR2/CD21) promoter reveals cell specific roles for RP58, E2A, USF and localized chromatin accessibility.

    PubMed

    Cruickshank, Mark N; Dods, James; Taylor, Rhonda L; Karimi, Mahdad; Fenwick, Emily J; Quail, Elizabeth A; Rea, Alexander J; Holers, V Michael; Abraham, Lawrence J; Ulgiati, Daniela

    2015-07-01

    Complement receptor 2 (CR2/CD21) plays an important role in the generation of normal B cell immune responses. As transcription appears to be the prime mechanism via which surface CR2/CD21 expression is controlled, understanding transcriptional regulation of this gene will have broader implications to B cell biology. Here we report opposing, cell-context specific control of CR2/CD21 promoter activity by tandem E-box elements, spaced 22 bp apart and within 70 bp of the transcription initiation site. We have identified E2A and USF transcription factors as binding to the distal and proximal E-box sites respectively in CR2-positive B-cells, at a site that is hypersensitive to restriction enzyme digestion compared to non-expressing K562 cells. However, additional unidentified proteins have also been found to bind these functionally important elements. By utilizing a proteomics approach we have identified a repressor protein, RP58, binding the distal E-box motif. Co-transfection experiments using RP58 overexpression constructs demonstrated a specific 10-fold repression of CR2/CD21 transcriptional activity mediated through the distal E-box repressor element. Taken together, our results indicate that repression of the CR2/CD21 promoter can occur through one of the E-box motifs via recruitment of RP58 and other factors to bring about a silenced chromatin context within CR2/CD21 non-expressing cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE2 induced pain model

    PubMed Central

    Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D.; da Silva, Carlos Antonio Trindade; Morisseau, Christophe; Hammock, Bruce D.

    2015-01-01

    Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100 mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3 mg/kg/day, p.o.) and OME (100 mg/kg/day, p.o., 7 days) + TPPU (3 mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE2 was monitored. While OME treatment by itself exhibited variable effects on PGE2 induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME + TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. PMID:26522832

  2. Lepeophtheirus salmonis: characterization of prostaglandin E(2) in secretory products of the salmon louse by RP-HPLC and mass spectrometry.

    PubMed

    Fast, M D; Ross, N W; Craft, C A; Locke, S J; MacKinnon, S L; Johnson, S C

    2004-01-01

    Lepeophtheirus salmonis is an ectoparasitic copepod that causes serious disease outbreaks in both wild and farmed salmonids. As the relationship between L. salmonis and its hosts is not well understood, the current investigation was undertaken to investigate whether any immunomodulatory compounds could be identified from secretions of L. salmonis. By incubating live L. salmonis adults with the neurotransmitter dopamine in seawater, we were able to obtain secretions from the parasite. These were analyzed by RP-HPLC column, as well as LC-MS. L. salmonis secretions contained a compound with the same retention time and mass of PGE(2). The identity of this compound as PGE(2) was confirmed by MS-in source dissociation. The concentrations of PGE(2) in L. salmonis secretions ranged from 0.2 to 12.3 ng/individual and varied with incubation temperature and time kept off the host. Prostaglandin E(2) is a potent vasodilator and thought to aid in parasite evasion from host immune responses. This is the first reported evidence of prostaglandin production in parasitic copepod secretions and its implications for the host-parasite relationship are discussed.

  3. Effects of endogenous pyrogen and prostaglandin E2 on hypothalamic neurons in rat brain slices.

    PubMed

    Watanabe, T; Morimoto, A; Murakami, N

    1987-06-01

    We investigated the effects of endogenous pyrogen and prostaglandin E2 (PGE2) on the preoptic and anterior hypothalamic (POAH) neurons using brain slice preparations from the rat. Partially purified endogenous pyrogen did not change the activities of most of the neurons in the POAH region when applied locally through a micropipette attached to the recording electrode in proximity to the neurons. This indicates that partially purified endogenous pyrogen does not act directly on the neuronal activity in the POAH region. The partially purified endogenous pyrogen, applied into a culture chamber containing a brain slice, facilitated the activities in 24% of the total neurons tested, regardless of the thermal specificity of the neurons. Moreover, PGE2 added to the culture chamber facilitated 48% of the warm-responsive, 33% of the cold-responsive, and 29% of the thermally insensitive neurons. The direction of change in neuronal activity induced by partially purified endogenous pyrogen appears to be almost the same as that induced by PGE2 when these substances were applied by perfusion to the same neuron in the culture chamber. These results suggest that partially purified pyrogen applied to the perfusate of the culture chamber stimulates some constituents of brain tissue to synthesize and release prostaglandin, which in turn affects the neuronal activity of the POAH region.

  4. Glial cells isolated from dorsal root ganglia express prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors.

    PubMed

    Ng, Kai Yu; Wong, Yung Hou; Wise, Helen

    2011-07-01

    Isolated cells from adult rat dorsal root ganglia (DRG) are frequently used as a model system to study responses of primary sensory neurons to nociceptor sensitizing agents such as prostaglandin E(2) and prostacyclin, which are presumed to act only on the neurons in typical mixed cell cultures. In the present study, we evaluated the expression of prostaglandin E(2) (EP(4)) and prostacyclin (IP) receptors in cultures of mixed DRG cells and in purified DRG glia. We show here that EP(4) and IP receptor agonists stimulated adenylyl cyclase activity in both mixed DRG cells and in purified DRG glia, and that these responses were specifically inhibited by EP(4) and IP receptor antagonists, respectively. The presence of EP(4) and IP receptors in DRG glia was further confirmed by the expression of EP(4) and IP receptor immunoreactivity and mRNA. With the increasing awareness of neuron-glial interactions within intact DRG and the use of isolated DRG cells in the study of mechanisms underlying nociception, it will be essential to consider the role played by EP(4) and IP receptor-expressing glial cells when evaluating prostanoid-induced sensitization of DRG neurons. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. PG&E and Silkwood

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1992-12-31

    The Supreme Court rendered its decision in PG&E in April 1983. The decision involved a challenge by a nuclear utility to a California state moratorium on the construction of new commercial nuclear power plants until the State Energy Resources Conservation and Development Commission could determine that there is a demonstrated and federally approved solution for the permanent disposal of high-level nuclear waste. The moratorium was based not on a state concern with the radiological hazards associated with new nuclear plants but, ostensibly on a state concern with the economics of new nuclear plants. In particular, the state had concluded thatmore » a new nuclear plant, in the absence of a solution for the permanent disposal of the high-level nuclear waste it would generate, would be an uneconomical and uncertain source of electric power. The nuclear utility that challenged the moratorium argued that its prohibition to new nuclear plant construction was in fact based on a state concern with radiation hazards. However, the Court accepted California`s {open_quotes}avowed economic purpose{close_quotes} and declined to second-guess the basis for the moratorium. The Court rendered its decision in Silkwood in January 1984. The decision involved an action brought by the administrator of the estate for a deceased employee of a nuclear fuel facility regulated by the NRC. Brought under Oklahoma state common law of torts, the action was for damages for radiological injuries suffered as a result of alleged plutonium contamination. A jury returned a verdict for the administrator as well as an award of actual and punitive damages.« less

  6. Inflammatory sensitization of nociceptors depends on activation of NMDA receptors in DRG satellite cells.

    PubMed

    Ferrari, Luiz Fernando; Lotufo, Celina Monteiro; Araldi, Dionéia; Rodrigues, Marcos A; Macedo, Larissa P; Ferreira, Sérgio H; Parada, Carlos Amilcar

    2014-12-23

    The present study evaluated the role of N-methyl-D-aspartate receptors (NMDARs) expressed in the dorsal root ganglia (DRG) in the inflammatory sensitization of peripheral nociceptor terminals to mechanical stimulation. Injection of NMDA into the fifth lumbar (L5)-DRG induced hyperalgesia in the rat hind paw with a profile similar to that of intraplantar injection of prostaglandin E2 (PGE2), which was significantly attenuated by injection of the NMDAR antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP-5) in the L5-DRG. Moreover, blockade of DRG AMPA receptors by the antagonist 6,7-dinitroquinoxaline-2,3-dione had no effect in the PGE2-induced hyperalgesia in the paw, showing specific involvement of NMDARs in this modulatory effect and suggesting that activation of NMDAR in the DRG plays an important role in the peripheral inflammatory hyperalgesia. In following experiments we observed attenuation of PGE2-induced hyperalgesia in the paw by the knockdown of NMDAR subunits NR1, NR2B, NR2D, and NR3A with antisense-oligodeoxynucleotide treatment in the DRG. Also, in vitro experiments showed that the NMDA-induced sensitization of cultured DRG neurons depends on satellite cell activation and on those same NMDAR subunits, suggesting their importance for the PGE2-induced hyperalgesia. In addition, fluorescent calcium imaging experiments in cultures of DRG cells showed induction of calcium transients by glutamate or NMDA only in satellite cells, but not in neurons. Together, the present results suggest that the mechanical inflammatory nociceptor sensitization is dependent on glutamate release at the DRG and subsequent NMDAR activation in satellite glial cells, supporting the idea that the peripheral hyperalgesia is an event modulated by a glutamatergic system in the DRG.

  7. Comparison of the effects of IV administration of meloxicam, carprofen, and flunixin meglumine on prostaglandin E(2) concentration in aqueous humor of dogs with aqueocentesis-induced anterior uveitis.

    PubMed

    Gilmour, Margi A; Payton, Mark E

    2012-05-01

    To compare the effects of meloxicam, carprofen, and flunixin meglumine administered IV on the concentration of prostaglandin E(2) (PGE(2)) in the aqueous humor of dogs with aqueocentesis-induced anterior uveitis. 15 adult dogs with ophthalmically normal eyes. Each dog was assigned to 1 of 4 treatment groups. Treatment groups were saline (0.9% NaCl) solution (1 mL, IV), meloxicam (0.2 mg/kg, IV), carprofen (4.4 mg/kg, IV), and flunixin meglumine (0.5 mg/kg, IV). Each dog was anesthetized, treatment was administered, and aqueocentesis was performed on each eye at 30 and 60 minutes after treatment. Aqueous humor samples were frozen at -80°C until assayed for PGE(2) concentration with an enzyme immunoassay kit. For all 4 treatment groups, PGE(2) concentration was significantly higher in samples obtained 60 minutes after treatment, compared with that in samples obtained 30 minutes after treatment, which indicated aqueocentesis-induced PGE(2) synthesis. For aqueous humor samples obtained 60 minutes after treatment, PGE(2) concentration did not differ significantly among groups treated with saline solution, meloxicam, and carprofen; however, the PGE(2) concentration for the group treated with flunixin meglumine was significantly lower than that for each of the other 3 treatment groups. Flunixin meglumine was more effective than meloxicam or carprofen for minimizing the PGE(2) concentration in the aqueous humor of dogs with experimentally induced uveitis. Flunixin meglumine may be an appropriate pre-medication for use prior to intraocular surgery in dogs.

  8. Pathophysiological roles of P2 receptors in glial cells.

    PubMed

    Abbracchio, Maria P; Verderio, Claudia

    2006-01-01

    Extracellular nucleotides act through specific receptors on target cells: the seven ionotropic P2X and the eight G protein-coupled P2Y receptors. All these receptors are expressed by brain astroglia and microglia. In astrocytes, P2 receptors have been implicated in short-term calcium-dependent cell-cell communication. Upon mechanical stimulation or activation by other transmitters, astrocytes release ATP and respond to ATP with a propagating wave of intracellular calcium increases, allowing a homotypic astrocyte-astrocyte communication, as well as an heterotypic signalling which also involves neurons, oligodendrocytes and microglia. Astrocytic P2 receptors also mediate reactive astrogliosis, a reaction contributing to neuronal death in neurodegenerative diseases. Signalling leading to inflammatory astrogliosis involves induction of cyclo-oxygenase 2 through stimulation of ERK1,2 and of the transcriptional factors AP-1 and NF-kappaB. Microglia also express several P2 receptors linked to intracellular calcium increases. P2 receptor subtypes are differentially regulated by typical proinflammatory signals for these cells (e.g. lipopolysaccharide), suggesting specific roles in brain immune responses. Globally, these findings highlight the roles of P2 receptors in glial cell pathophysiology suggesting a contribution to neurodegenerative diseases characterized by excessive gliosis and neuro-inflammation. They also open up the possibility of modulating brain damage by ligands selectively targeting the specific P2 receptor subtypes involved in the gliotic response.

  9. The SK-N-AS human neuroblastoma cell line develops osteolytic bone metastases with increased angiogenesis and COX-2 expression

    PubMed Central

    Tsutsumimoto, Takahiro; Williams, Paul; Yoneda, Toshiyuki

    2014-01-01

    Neuroblastoma (NB), which arises from embryonic neural crest cells, is the most common extra-cranial solid tumor of childhood. Approximately half of NB patients manifest bone metastasis accompanied with bone pain, fractures and bone marrow failure, leading to disturbed quality of life and poor survival. To study the mechanism of bone metastasis of NB, we established an animal model in which intracardiac inoculation of the SK-N-AS human NB cells in nude mice developed osteolytic bone metastases with increased osteoclastogenesis. SK-N-AS cells induced the expression of receptor activator of NF-κB ligand and osteoclastogenesis in mouse bone marrow cells in the co-culture. SK-N-AS cells expressed COX-2 mRNA and produced substantial amounts of prostaglandin E2 (PGE2). In contrast, the SK-N-DZ and SK-N-FI human NB cells failed to develop bone metastases, induce osteoclastogenesis, express COX-2 mRNA and produce PGE2. Immunohistochemical examination of SK-N-AS bone metastasis and subcutaneous tumor showed strong expression of COX-2. The selective COX-2 inhibitor NS-398 inhibited PGE2 production and suppressed bone metastases with reduced osteoclastogenesis. NS-398 also inhibited subcutaneous SK-N-AS tumor development with decreased angiogenesis and vascular endothelial growth factor-A expression. Of interest, metastasis to the adrenal gland, a preferential site for NB development, was also diminished by NS-398. Our results suggest that COX2/PGE2 axis plays a critical role in the pathophysiology of osteolytic bone metastases and tumor development of the SK-NS-AS human NB. Inhibition of angiogenesis by suppressing COX-2/PGE2 may be an effective therapeutic approach for children with NB. PMID:26909300

  10. The protease-activated receptor-2 upregulates keratinocyte phagocytosis.

    PubMed

    Sharlow, E R; Paine, C S; Babiarz, L; Eisinger, M; Shapiro, S; Seiberg, M

    2000-09-01

    The protease-activated receptor-2 (PAR-2) belongs to the family of seven transmembrane domain receptors, which are activated by the specific enzymatic cleavage of their extracellular amino termini. Synthetic peptides corresponding to the tethered ligand domain (SLIGRL in mouse, SLIGKV in human) can activate PAR-2 without the need for receptor cleavage. PAR-2 activation is involved in cell growth, differentiation and inflammatory processes, and was shown to affect melanin and melanosome ingestion by human keratinocytes. Data presented here suggest that PAR-2 activation may regulate human keratinocyte phagocytosis. PAR-2 activation by trypsin, SLIGRL or SLIGKV increased the ability of keratinocytes to ingest fluorescently labeled microspheres or E. coli K-12 bioparticles. This PAR-2 mediated increase in keratinocyte phagocytic capability correlated with an increase in actin polymerization and *-actinin reorganization, cell surface morphological changes and increased soluble protease activity. Moreover, addition of serine protease inhibitors downmodulated both the constitutive and the PAR-2 mediated increases in phagocytosis, suggesting that serine proteases mediate this functional activity in keratinocytes. PAR-2 involvement in keratinocyte phagocytosis is a novel function for this receptor.

  11. Hetero-oligomerization of the P2Y11 receptor with the P2Y1 receptor controls the internalization and ligand selectivity of the P2Y11 receptor.

    PubMed

    Ecke, Denise; Hanck, Theodor; Tulapurkar, Mohan E; Schäfer, Rainer; Kassack, Matthias; Stricker, Rolf; Reiser, Georg

    2008-01-01

    Nucleotides signal through purinergic receptors such as the P2 receptors, which are subdivided into the ionotropic P2X receptors and the metabotropic P2Y receptors. The diversity of functions within the purinergic receptor family is required for the tissue-specificity of nucleotide signalling. In the present study, hetero-oligomerization between two metabotropic P2Y receptor subtypes is established. These receptors, P2Y1 and P2Y11, were found to associate together when co-expressed in HEK293 cells. This association was detected by co-pull-down, immunoprecipitation and FRET (fluorescence resonance energy transfer) experiments. We found a striking functional consequence of the interaction between the P2Y11 receptor and the P2Y1 receptor where this interaction promotes agonist-induced internalization of the P2Y11 receptor. This is remarkable because the P2Y11 receptor by itself is not able to undergo endocytosis. Co-internalization of these receptors was also seen in 1321N1 astrocytoma cells co-expressing both P2Y11 and P2Y1 receptors, upon stimulation with ATP or the P2Y1 receptor-specific agonist 2-MeS-ADP. 1321N1 astrocytoma cells do not express endogenous P2Y receptors. Moreover, in HEK293 cells, the P2Y11 receptor was found to functionally associate with endogenous P2Y1 receptors. Treatment of HEK293 cells with siRNA (small interfering RNA) directed against the P2Y1 receptor diminished the agonist-induced endocytosis of the heterologously expressed GFP-P2Y11 receptor. Pharmacological characteristics of the P2Y11 receptor expressed in HEK293 cells were determined by recording Ca2+ responses after nucleotide stimulation. This analysis revealed a ligand specificity which was different from the agonist profile established in cells expressing the P2Y11 receptor as the only metabotropic nucleotide receptor. Thus the hetero-oligomerization of the P2Y1 and P2Y11 receptors allows novel functions of the P2Y11 receptor in response to extracellular nucleotides.

  12. Comparative study of labour induced by oral prostaglandin E2 and intravenous syntocinon.

    PubMed

    Murray, C P; Clinch, J

    1975-03-22

    The use of prostaglandin E2 for the induction of labor with intact membranes is described and its effectiveness is compared to intravenous syntocinon. 40 primigravida and 60 multigravid patients with previous medical and obstetrical histories were studied. The patients were numbered as they entered the trial, with the odd numbers in each group being given oral prostaglandin and the even numbers intravenous syntocinon. In no case was the pregnancy less than 38 weeks maturity. No patient was in labor prior to being given either drug. Prostaglandin E2 (PGE2) was supplied in ampoules containing 5 milligrams in 0.5 milliliter of ethanol. This was added to 49.5 milliliters of sterile water to produce a concentration of the drug of 0.1 milligrams per ml. The syntocinon infusion was prepared by putting 20 units of syntocinon into 1 liter of 5% dextrose in water to produce a solution concentration of 20 mu/ml. The accepted criteria for diagnosing established labor for both groups of patients was the presence of uterine contractions occurring once every 3 minutes, associated with progressive dilatation of the cervix. For both groups of patients it was decided that cervical dilatation should be at least 6 cm within 18 hours of the infusion starting. Using this criterion there was only 1 failure, occurring in the 1st primigravid patient given PGE2, the labor in this instance being completed with intravenous syntocinon. A further 8 patients failed to complete the trial as they had to be delivered by cesarian section. Syntocin was considerably more efficient than PGE2 in inducing labor in the remaining 91 patients particularly in primigravida. This was the case whether judged by the length of labor or by the induction delivery interval. Toco-dynamometric studies showed that the contractions produced by prostaglandin more closely resembled those of normal labor and were less painful.

  13. The release of spinal prostaglandin E2 and the effect of nitric oxide synthetase inhibition during strychnine-induced allodynia.

    PubMed

    Milne, B; Hall, S R; Sullivan, M E; Loomis, C

    2001-09-01

    The removal of spinal glycinergic inhibition by intrathecal strychnine produces an allodynia-like state in rodents. Our objective was to measure spinal prostaglandin E2 (PGE2) release during strychnine-allodynia and examine the effects of Nomega-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthetase. Under halothane, rats were fitted with intrathecal and spinal microdialysis catheters, and microelectrodes implanted into the locus coeruleus for measurement of catechol oxidation current (CAOC) using voltammetry. Animals were then administered urethane and treated as follows: 1) baseline control 10 min, intrathecal strychnine (40 microg) 10 min, 10 min of hair deflection, and 2) 10-min control followed by intrathecal strychnine (40 microg) with hair deflection for 60 min. Spinal dialysate samples were collected for PGE2 levels determined by using immunoassay. In separate experiments, the effect of intrathecal strychnine (40 microg) followed by hair deflection was studied in rats pretreated with intrathecal l-NOARG (50 nmol). After intrathecal strychnine, hair deflection significantly increased spinal PGE2 release (619% +/- 143%), locus coeruleus CAOC (181% +/- 6%), and mean arterial pressure (123% +/- 2%) P < 0.05. Pretreatment with intrathecal l-NOARG significantly inhibited strychnine-allodynia. In this model, hair deflection evokes spinal PGE2 release, locus coeruleus activation, and an increase in mean arterial pressure. L-NOARG pretreatment attenuated the locus coeruleus CAOC, a biochemical index of strychnine-allodynia, suggesting a mediator role of nitric oxide. A mediator role of nitric oxide is also implicated, helping to explain the pathophysiology of this allodynic pain.

  14. N-glycosylation of the β2 adrenergic receptor regulates receptor function by modulating dimerization.

    PubMed

    Li, Xiaona; Zhou, Mang; Huang, Wei; Yang, Huaiyu

    2017-07-01

    N-glycosylation is a common post-translational modification of G-protein-coupled receptors (GPCRs). However, it remains unknown how N-glycosylation affects GPCR signaling. β 2 adrenergic receptor2 AR) has three N-glycosylation sites: Asn6, Asn15 at the N-terminus, and Asn187 at the second extracellular loop (ECL2). Here, we show that deletion of the N-glycan did not affect receptor expression and ligand binding. Deletion of the N-glycan at the N-terminus rather than Asn187 showed decreased effects on isoproterenol-promoted G-protein-dependent signaling, β-arrestin2 recruitment, and receptor internalization. Both N6Q and N15Q showed decreased receptor dimerization, while N187Q did not influence receptor dimerization. As decreased β 2 AR homodimer accompanied with reduced efficiency for receptor function, we proposed that the N-glycosylation of β 2 AR regulated receptor function by influencing receptor dimerization. To verify this hypothesis, we further paid attention to the residues at the dimerization interface. Studies of Lys60 and Glu338, two residues at the receptor dimerization interface, exhibited that the K60A/E338A showed decreased β 2 AR dimerization and its effects on receptor signaling were similar to N6Q and N15Q, which further supported the importance of receptor dimerization for receptor function. This work provides new insights into the relationship among glycosylation, dimerization, and function of GPCRs. Peptide-N-glycosidase F (PNGase F, EC 3.2.2.11); endo-β-N-acetylglucosaminidase A (Endo-A, EC 3.2.1.96). © 2017 Federation of European Biochemical Societies.

  15. Structurally related odorant ligands of the olfactory receptor OR51E2 differentially promote metastasis emergence and tumor growth

    PubMed Central

    Sanz, Guenhaël; Leray, Isabelle; Grébert, Denise; Antoine, Sharmilee; Acquistapace, Adrien; Muscat, Adeline; Boukadiri, Abdelhak; Mir, Lluis M.

    2017-01-01

    Olfactory receptors are G protein-coupled receptors. Some of them are expressed in tumor cells, such as the OR51E2 receptor overexpressed in LNCaP prostate cancer cells. It is considered a prostate tumor marker. We previously demonstrated that this receptor is able to promote LNCaP cell invasiveness in vitro upon stimulation with its odorant agonist β-ionone, leading to increased generation of metastases in vivo. In the present study, we show that even a relatively short exposure to β-ionone is sufficient to promote metastasis emergence. Moreover, α-ionone, considered an OR51E2 antagonist, in fact promotes prostate tumor growth in vivo. The combination of α-ionone with β-ionone triggers a higher increase in the total tumor burden than each molecule alone. To support the in vivo results, we demonstrate in vitro that α-ionone is a real agonist of OR51E2, mainly sustaining LNCaP cell growth, while β-ionone mainly promotes cell invasiveness. So, while structurally close, α-ionone and β-ionone appear to induce different cellular effects, both leading to increased tumor aggressiveness. This behaviour could be explained by a different coupling to downstream effectors, as it has been reported for the so-called biased ligands of other G protein-coupled receptors. PMID:28032594

  16. Inhibition of cartilage degradation and suppression of PGE2 and MMPs expression by pomegranate fruit extract in a model of posttraumatic osteoarthritis.

    PubMed

    Akhtar, Nahid; Khan, Nazir M; Ashruf, Omer S; Haqqi, Tariq M

    2017-01-01

    Osteoarthritis (OA) is characterized by cartilage degradation in the affected joints. Pomegranate fruit extract (PFE) inhibits cartilage degradation in vitro. The aim of this study was to determine whether oral consumption of PFE inhibits disease progression in rabbits with surgically induced OA. OA was surgically induced in the tibiofemoral joints of adult New Zealand White rabbits. In one group, animals were fed PFE in water for 8 wk postsurgery. In the second group, animals were fed PFE for 2 wk before surgery and for 8 wk postsurgery. Histologic assessment and scoring of the cartilage was per Osteoarthritis Research Society International guidelines. Gene expression and matrix metalloproteinases (MMP) activity were determined using quantitative reverse transcriptase polymerase chain reaction and fluorometric assay, respectively. Interleukin (IL)-1 β, MMP-13, IL-6, prostaglandin (PG)E 2 , and type II collagen (COL2A1) levels in synovial fluid/plasma/culture media were quantified using enzyme-linked immunosorbent assay. Expression of active caspase-3 and poly (ADP-ribose) polymerase p85 was determined by immunohistochemistry. Effect of PFE and inhibitors of MMP-13, mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB was studied in IL-1 β-stimulated rabbit articular chondrocytes. Safranin-O-staining and chondrocyte cluster formation was significantly reduced in the anterior cruciate ligament transaction plus PFE fed groups. Expression of MMP-3, MMP-9, and MMP-13 mRNA was higher in the cartilage of rabbits given water alone but was significantly lower in the animals fed PFE. PFE-fed rabbits had lower IL-6, MMP-13, and PGE 2 levels in the synovial fluid and plasma, respectively, and showed higher expression of aggrecan and COL2A1 mRNA. Significantly higher numbers of chondrocytes were positive for markers of apoptosis in the joints of rabbits with OA given water only compared with those in the PFE-fed groups. PFE pretreatment significantly

  17. Stromal Cells Positively and Negatively Modulate the Growth of Cancer Cells: Stimulation via the PGE2-TNFα-IL-6 Pathway and Inhibition via Secreted GAPDH-E-Cadherin Interaction

    PubMed Central

    Kawada, Manabu; Inoue, Hiroyuki; Ohba, Shun-ichi; Yoshida, Junjiro; Masuda, Tohru; Yamasaki, Manabu; Usami, Ihomi; Sakamoto, Shuichi; Abe, Hikaru; Watanabe, Takumi; Yamori, Takao; Shibasaki, Masakatsu; Nomoto, Akio

    2015-01-01

    Fibroblast-like stromal cells modulate cancer cells through secreted factors and adhesion, but those factors are not fully understood. Here, we have identified critical stromal factors that modulate cancer growth positively and negatively. Using a cell co-culture system, we found that gastric stromal cells secreted IL-6 as a growth and survival factor for gastric cancer cells. Moreover, gastric cancer cells secreted PGE2 and TNFα that stimulated IL-6 secretion by the stromal cells. Furthermore, we found that stromal cells secreted glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Extracellular GAPDH, or its N-terminal domain, inhibited gastric cancer cell growth, a finding confirmed in other cell systems. GAPDH bound to E-cadherin and downregulated the mTOR-p70S6 kinase pathway. These results demonstrate that stromal cells could regulate cancer cell growth through the balance of these secreted factors. We propose that negative regulation of cancer growth using GAPDH could be a new anti-cancer strategy. PMID:25785838

  18. Promotion of adipogenesis by an EP2 receptor agonist via stimulation of angiogenesis in pulmonary emphysema.

    PubMed

    Tsuji, Takao; Yamaguchi, Kazuhiro; Kikuchi, Ryota; Itoh, Masayuki; Nakamura, Hiroyuki; Nagai, Atsushi; Aoshiba, Kazutetsu

    2014-08-01

    Body weight loss is a common manifestation in patients with chronic obstructive pulmonary disease (COPD), particularly those with severe emphysema. Adipose angiogenesis is a key mediator of adipogenesis and use of pro-angiogenic agents may serve as a therapeutic option for lean COPD patients. Since angiogenesis is stimulated by PGE2, we examined whether ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, might promote adipose angiogenesis and adipogenesis in a murine model of elastase-induced pulmonary emphysema (EIE mice). Mice were intratracheally instilled with elastase or saline, followed after 4 weeks by intraperitoneal administration of ONO-AE1-259 for 4 weeks. The subcutaneous adipose tissue (SAT) weight decreased in the EIE mice, whereas in the EIE mice treated with ONO-AE1-259, the SAT weight was largely restored, which was associated with significant increases in SAT adipogenesis, angiogenesis, and VEGF protein production. In contrast, ONO-AE1-259 administration induced no alteration in the weight of the visceral adipose tissue. These results suggest that in EIE mice, ONO-AE1-259 stimulated adipose angiogenesis possibly via VEGF production, and thence, adipogenesis. Our data pave the way for the development of therapeutic interventions for weight loss in emphysema patients, e.g., use of pro-angiogenic agents targeting the adipose tissue vascular component. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. A novel CCR2 antagonist inhibits atherogenesis in apoE deficient mice by achieving high receptor occupancy.

    PubMed

    Bot, Ilze; Ortiz Zacarías, Natalia V; de Witte, Wilhelmus E A; de Vries, Henk; van Santbrink, Peter J; van der Velden, Daniël; Kröner, Mara J; van der Berg, Dirk-Jan; Stamos, Dean; de Lange, Elizabeth C M; Kuiper, Johan; IJzerman, Adriaan P; Heitman, Laura H

    2017-03-03

    CC Chemokine Receptor 2 (CCR2) and its endogenous ligand CCL2 are involved in a number of diseases, including atherosclerosis. Several CCR2 antagonists have been developed as potential therapeutic agents, however their in vivo clinical efficacy was limited. In this report, we aimed to determine whether 15a, an antagonist with a long residence time on the human CCR2, is effective in inhibiting the development of atherosclerosis in a mouse disease model. First, radioligand binding assays were performed to determine affinity and binding kinetics of 15a on murine CCR2. To assess the in vivo efficacy, western-type diet fed apoE -/- mice were treated daily with 15a or vehicle as control. Treatment with 15a reduced the amount of circulating CCR2 + monocytes and the size of the atherosclerotic plaques in both the carotid artery and the aortic root. We then showed that the long pharmacokinetic half-life of 15a combined with the high drug concentrations ensured prolonged CCR2 occupancy. These data render 15a a promising compound for drug development and confirms high receptor occupancy as a key parameter when targeting chemokine receptors.

  20. The involvement of sympathetic nerves in plasma extravasation induced by prostaglandin E2 and substance P.

    PubMed

    Mathison, R; Davison, J S

    1994-05-02

    The effects of intravenous injection of prostaglandin E2 (PGE2), substance P (SP) and a metabolically stable SP analogue, [pGlu5,Me-Phe8,Sar9]-SP (5-11) on plasma extravasation of albumin in the rat after blockade of prostaglandin synthesis with indomethacin or chemical sympathectomy with guanethidine were studied. Blood pressure was decreased by all agonists, but only the hypotensive effects of SP were enhanced by pretreatment with indomethacin and guanethidine. The increase in plasma extravasation induced by PGE2 in the tongue, skin and lungs was blocked by both guanethidine and indomethacin. Pretreatment of the rats with guanethidine or indomethacin increased extravasation induced by SP in the tongue-tip, dorsal skin and foot, but decreased the enhanced permeability in the pinna, and did not alter the actions of the peptide in other tissues. In contrast, both guanethidine and indomethacin pretreatment increased vascular permeability responses to [pGlu5,Me-Phe8,Sar9]-SP (5-11) administration in 9 and 14 of 16 tissues examined, respectively. Thus, intact sympathetic nerves and functional cycloxygenase activity exert inhibitory constraints on the vascular permeability effects of intravenously administered SP or its analogue. On the other hand the integrity of the sympathetic nerves and prostaglandin synthesis are required for PGE2-induced increases in vascular leak.

  1. Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists.

    PubMed

    Cheng, Jianjun; McCorvy, John D; Giguere, Patrick M; Zhu, Hu; Kenakin, Terry; Roth, Bryan L; Kozikowski, Alan P

    2016-11-10

    On the basis of the structural similarity of our previous 5-HT 2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofuran-based compounds were designed and synthesized. The compounds were evaluated for their selectivity toward 5-HT 2A , 5-HT 2B , and 5-HT 2C receptors in the calcium flux assay with the ultimate goal to generate selective 5-HT 2C agonists. Selected compounds were studied for their functional selectivity by comparing their transduction efficiency at the G protein signaling pathway versus β-arrestin recruitment. The most functionally selective compound (+)-7e produced weak β-arrestin recruitment and also demonstrated less receptor desensitization compared to serotonin in both calcium flux and phosphoinositide (PI) hydrolysis assays. We report for the first time that selective 5-HT 2C agonists possessing weak β-arrestin recruitment can produce distinct receptor desensitization properties.

  2. Identification of the cAMP response element that controls transcriptional activation of the insulin-like growth factor-I gene by prostaglandin E2 in osteoblasts

    NASA Technical Reports Server (NTRS)

    Thomas, M. J.; Umayahara, Y.; Shu, H.; Centrella, M.; Rotwein, P.; McCarthy, T. L.

    1996-01-01

    Insulin-like growth factor-I (IGF-I), a multifunctional growth factor, plays a key role in skeletal growth and can enhance bone cell replication and differentiation. We previously showed that prostaglandin E2 (PGE2) and other agents that increase cAMP activated IGF-I gene transcription in primary rat osteoblast cultures through promoter 1 (P1), the major IGF-I promoter, and found that transcriptional induction was mediated by protein kinase A. We now have identified a short segment of P1 that is essential for full hormonal regulation and have characterized inducible DNA-protein interactions involving this site. Transient transfections of IGF-I P1 reporter genes into primary rat osteoblasts showed that the 328-base pair untranslated region of exon 1 was required for a full 5.3-fold response to PGE2; mutation in a previously footprinted site, HS3D (base pairs +193 to +215), reduced induction by 65%. PGE2 stimulated nuclear protein binding to HS3D. Binding, as determined by gel mobility shift assay, was not seen in nuclear extracts from untreated osteoblast cultures, was detected within 2 h of PGE2 treatment, and was maximal by 4 h. This DNA-protein interaction was not observed in cytoplasmic extracts from PGE2-treated cultures, indicating nuclear localization of the protein kinase A-activated factor(s). Activation of this factor was not blocked by cycloheximide (Chx), and Chx did not impair stimulation of IGF-I gene expression by PGE2. In contrast, binding to a consensus cAMP response element (CRE; 5'-TGACGTCA-3') from the rat somatostatin gene was not modulated by PGE2 or Chx. Competition gel mobility shift analysis using mutated DNA probes identified 5'-CGCAATCG-3' as the minimal sequence needed for inducible binding. All modified IGF-I P1 promoterreporter genes with mutations within this CRE sequence also showed a diminished functional response to PGE2. These results identify the CRE within the 5'-untranslated region of IGF-I exon 1 that is required for hormonal

  3. Nedd4 is a Specific E3 Ubiquitin Ligase for the NMDA Receptor Subunit GluN2D

    PubMed Central

    Gautam, Vivek; Trinidad, Jonathan C.; Rimerman, Ronald A.; Costa, Blaise M.; Burlingame, Alma L.; Monaghan, Daniel T.

    2013-01-01

    NMDA receptors are a family of glutamate-gated ion channels that regulate various CNS functions such as synaptic plasticity and learning. However hypo-or hyper-activation of NMDA receptors is critically involved in many neurological and psychiatric conditions such as pain, stroke, epilepsy, neurodegeneration, schizophrenia, and depression. Thus, it is important to identify mechanisms (such as by targeted ubiquitination) that regulate the levels of individual subtypes of NMDA receptors. In this study, we used a series of tagged, carboxy terminal constructs of GluN2D to identify associating proteins from rat brain. Of seven different GluN2D C-terminal fragments used as bait, only the construct containing amino acids 983-1097 associated with an E3 ligase, Nedd4. A direct interaction between GluN2D and Nedd4 was confirmed both in vivo and in vitro. This association is mediated by an interaction between GluN2D's C-terminal PPXY motif and the 2nd and 3rd WW domains of Nedd4. Of the four GluN2 subunits, Nedd4 directly interacted with GluN2D and also weakly with GluN2A. Nedd4 coexpression with GluN2D enhances GluN2D ubiquitination and reduces GluN1/GluN2D NMDA receptor responses. These results identify Nedd4 as a novel binding partner for GluN2D and suggest a mechanism for the regulation of NMDA receptors that contains GluN2D subunit through ubiquitination-dependent downregulation. PMID:23639431

  4. In vitro effect of. Delta. sup 9 -tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E sub 2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rettori, V.; Aguila, M.C.; McCann, S.M.

    Previous in vivo studies have shown that {Delta}{sup 9}-tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release.more » The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E{sub 2} (PGE{sub 2}) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE{sub 2} suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE{sub 2} synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release.« less

  5. Acetylsalicylic Acid Daily vs Acetylsalicylic Acid Every 3 Days in Healthy Volunteers: Effect on Platelet Aggregation, Gastric Mucosa, and Prostaglandin E2 Synthesis.

    PubMed

    Ferreira, Plinio Minghin Freitas; Gagliano-Jucá, Thiago; Zaminelli, Tiago; Sampaio, Marinalva Ferreira; Blackler, Rory Willian; Trevisan, Miriam da Silva; Novaes Magalhães, Antônio Frederico; De Nucci, Gilberto

    2016-07-01

    Substantial platelet inhibition was observed 3 days after a single administration of acetylsalicylic acid 81 mg to healthy volunteers. Here we investigate prostaglandin E2 (PGE2 ) antrum concentrations and gastrointestinal symptoms in two treatment groups: one receiving losartan and acetylsalicylic acid every day and the other receiving losartan every day and acetylsalicylic acid every 3 days. Twenty-eight healthy volunteers from both sexes received either 50 mg losartan and acetylsalicylic acid 81 mg daily or 50 mg losartan and acetylsalicylic acid 81 every 3 days with placebo on the other days. Therapy was delivered for 30 days for both groups. Gastric endoscopy was performed before and after treatment period. Biopsies were collected for PGE2 quantification. Platelet function tests were carried out before and during treatment and TXB2 release on platelet rich plasma was measured. The every 3 day low-dose acetylsalicylic acid regimen produced complete inhibition of platelet aggregation compared to the daily treatment. Thromboxane B2 release was substantially abolished for both groups during treatment. There was no significant difference on the endoscopic score of both treatment groups after the 30-day treatment (P = .215). There was over 50% suppression of antrum PGE2 content on volunteers receiving acetylsalicylic acid daily (P = .0016), while for the every 3 day dose regimen there was no significant difference between pre and post-treatment antrum PGE2 dosages (P = .4193). Since PGE2 is involved in gastric healing, we understand that this new approach could be safer and as efficient as the standard daily therapy on a long-term basis. © 2015, The American College of Clinical Pharmacology.

  6. Adenosine A2a receptors and O2 sensing in development

    PubMed Central

    2011-01-01

    Reduced mitochondrial oxidative phosphorylation, via activation of adenylate kinase and the resulting exponential rise in the cellular AMP/ATP ratio, appears to be a critical factor underlying O2 sensing in many chemoreceptive tissues in mammals. The elevated AMP/ATP ratio, in turn, activates key enzymes that are involved in physiologic adjustments that tend to balance ATP supply and demand. An example is the conversion of AMP to adenosine via 5′-nucleotidase and the resulting activation of adenosine A2A receptors, which are involved in acute oxygen sensing by both carotid bodies and the brain. In fetal sheep, A2A receptors associated with carotid bodies trigger hypoxic cardiovascular chemoreflexes, while central A2A receptors mediate hypoxic inhibition of breathing and rapid eye movements. A2A receptors are also involved in hypoxic regulation of fetal endocrine systems, metabolism, and vascular tone. In developing lambs, A2A receptors play virtually no role in O2 sensing by the carotid bodies, but brain A2A receptors remain critically involved in the roll-off ventilatory response to hypoxia. In adult mammals, A2A receptors have been implicated in O2 sensing by carotid glomus cells, while central A2A receptors likely blunt hypoxic hyperventilation. In conclusion, A2A receptors are crucially involved in the transduction mechanisms of O2 sensing in fetal carotid bodies and brains. Postnatally, central A2A receptors remain key mediators of hypoxic respiratory depression, but they are less critical for O2 sensing in carotid chemoreceptors, particularly in developing lambs. PMID:21677265

  7. Affinity purification of angiotensin type 2 receptors from N1E-115 cells: evidence for agonist-induced formation of multimeric complexes.

    PubMed

    Siemens, I R; Yee, D K; Reagan, L P; Fluharty, S J

    1994-01-01

    The murine neuroblastoma N1E-115 cell line possesses type 1 and type 2 angiotensin II (AngII) receptor subtypes. In vitro differentiation of these cells substantially increases the density of the AT2-receptor subtype, whereas the density of the AT1 receptors remains unchanged. In the present study, we report that the zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) selectively solubilized AT2 receptors from N1E-115 cell membranes and that these receptors could be purified further to near homogeneity by affinity chromatography. More specifically, the presence of an agonist (AngII) during affinity purification of AT2 receptors resulted in the elution of high (110-kDa) and low (66-kDa) molecular mass proteins as determined by gel electrophoresis under nonreducing conditions. In contrast, when the nonselective antagonist Sar1,Ile8-AngII was used during purification, only the lower 66-kDa protein was observed. Affinity purification in the presence of the peptide and nonpeptide AT2-receptor antagonists CGP42112A and PD123319 also resulted in elution of the same 66-kDa protein, but unlike that in the presence of Sar1,Ile8-AngII, some of the high molecular weight site was observed as well. On the other hand, Losartan, an AT1-receptor antagonist, was completely ineffective in eluting any AngII receptors from the affinity column, further confirming their AT2 identity. After agonist elution, the 110-kDa band dissociated into two low molecular mass bands of 66 kDa and 54 kDa when sodium dodecyl sulfate-gel electrophoresis was run under reducing conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Selective Imaging of Vascular Endothelial Growth Factor Receptor-1 and Receptor-2 in Atherosclerotic Lesions in Diabetic and Non-diabetic ApoE-/- Mice.

    PubMed

    Tekabe, Yared; Johnson, Lynne L; Rodriquez, Krissy; Li, Qing; Backer, Marina; Backer, Joseph M

    2018-02-01

    Plaque vulnerability is associated with inflammation and angiogenesis, processes that rely on vascular endothelial growth factor (VEGF) signaling via two receptors, VEGFR-1 and VEGFR-2. We have recently reported that enhanced uptake of scVEGF-PEG-DOTA/Tc-99m (scV/Tc) single photon emission computed tomography (SPECT) tracer that targets both VEGFR-1 and VEGFR-2, identifies accelerated atherosclerosis in diabetic relative to non-diabetic ApoE -/- mice. Since VEGFR-1 and VEGFR-2 may play different roles in atherosclerotic plaques, we reasoned that selective imaging of each receptor can provide more detailed information on plaque biology. Recently described VEGFR-1 and VEGFR-2 selective mutants of scVEGF, named scVR1 and scVR2, were site-specifically derivatized with Tc-99m chelator DOTA via 3.4 kDa PEG linker, and their selectivity to the cognate receptors was confirmed in vitro. scVR1 and scVR2 conjugates were radiolabeled with Tc-99m to specific activity of 110 ± 11 MBq/nmol, yielding tracers named scVR1/Tc and scVR2/Tc. 34-40 week old diabetic and age-matched non-diabetic ApoE -/- mice were injected with tracers, 2-3 h later injected with x-ray computed tomography (CT) contrast agent and underwent hybrid SPECT/CT imaging. Tracer uptake, localized to proximal aorta and brachiocephalic vessels, was quantified as %ID from. Tracer uptake was also quantified as %ID/g from gamma counting of harvested plaques. Harvested atherosclerotic arterial tissue was used for immunofluorescent analyses of VEGFR-1 and VEGFR-2 and various lineage-specific markers. Focal, receptor-mediated uptake in proximal aorta and brachiocephalic vessels was detected for both scVR1/Tc and scVR2/Tc tracers. Uptake of scVR1/Tc and scVR2/Tc was efficiently inhibited only by "cold" proteins of the same receptor selectivity. Tracer uptake in this area, expressed as %ID, was higher in diabetic vs. non- diabetic mice for scVR1/Tc (p = 0.01) but not for scVR2/Tc. Immunofluorescent analysis

  9. Prostaglandins and Their Receptors in Eosinophil Function and As Therapeutic Targets

    PubMed Central

    Peinhaupt, Miriam; Sturm, Eva M.; Heinemann, Akos

    2017-01-01

    Of the known prostanoid receptors, human eosinophils express the prostaglandin D2 (PGD2) receptors DP1 [also D-type prostanoid (DP)] and DP2 (also chemoattractant receptor homologous molecule, expressed on Th2 cells), the prostaglandin E2 receptors EP2 and EP4, and the prostacyclin (PGI2) receptor IP. Prostanoids can bind to either one or multiple receptors, characteristically have a short half-life in vivo, and are quickly degraded into metabolites with altered affinity and specificity for a given receptor subtype. Prostanoid receptors signal mainly through G proteins and naturally activate signal transduction pathways according to the G protein subtype that they preferentially interact with. This can lead to the activation of sometimes opposing signaling pathways. In addition, prostanoid signaling is often cell-type specific and also the combination of expressed receptors can influence the outcome of the prostanoid impulse. Accordingly, it is assumed that eosinophils and their (patho-)physiological functions are governed by a sensitive prostanoid signaling network. In this review, we specifically focus on the functions of PGD2, PGE2, and PGI2 and their receptors on eosinophils. We discuss their significance in allergic and non-allergic diseases and summarize potential targets for drug intervention. PMID:28770200

  10. Inhibition of microsomal prostaglandin E2 synthase-1 as a molecular basis for the anti-inflammatory actions of boswellic acids from frankincense

    PubMed Central

    Siemoneit, U; Koeberle, A; Rossi, A; Dehm, F; Verhoff, M; Reckel, S; Maier, TJ; Jauch, J; Northoff, H; Bernhard, F; Doetsch, V; Sautebin, L; Werz, O

    2011-01-01

    BACKGROUND AND PURPOSE Frankincense, the gum resin derived from Boswellia species, showed anti-inflammatory efficacy in animal models and in pilot clinical studies. Boswellic acids (BAs) are assumed to be responsible for these effects but their anti-inflammatory efficacy in vivo and their molecular modes of action are incompletely understood. EXPERIMENTAL APPROACH A protein fishing approach using immobilized BA and surface plasmon resonance (SPR) spectroscopy were used to reveal microsomal prostaglandin E2 synthase-1 (mPGES1) as a BA-interacting protein. Cell-free and cell-based assays were applied to confirm the functional interference of BAs with mPGES1. Carrageenan-induced mouse paw oedema and rat pleurisy models were utilized to demonstrate the efficacy of defined BAs in vivo. KEY RESULTS Human mPGES1 from A549 cells or in vitro-translated human enzyme selectively bound to BA affinity matrices and SPR spectroscopy confirmed these interactions. BAs reversibly suppressed the transformation of prostaglandin (PG)H2 to PGE2 mediated by mPGES1 (IC50 = 3–10 µM). Also, in intact A549 cells, BAs selectively inhibited PGE2 generation and, in human whole blood, β-BA reduced lipopolysaccharide-induced PGE2 biosynthesis without affecting formation of the COX-derived metabolites 6-keto PGF1α and thromboxane B2. Intraperitoneal or oral administration of β-BA (1 mg·kg−1) suppressed rat pleurisy, accompanied by impaired levels of PGE2 and β-BA (1 mg·kg−1, given i.p.) also reduced mouse paw oedema, both induced by carrageenan. CONCLUSIONS AND IMPLICATIONS Suppression of PGE2 formation by BAs via interference with mPGES1 contribute to the anti-inflammatory effectiveness of BAs and of frankincense, and may constitute a biochemical basis for their anti-inflammatory properties. PMID:20840544

  11. Restoration of prostaglandin E2-producing splenic macrophages in sup 89 Sr-treated mice with bone marrow from Corynebacterium parvum primed donors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shibata, Y.

    1989-05-01

    Administration of Corynebacterium parvum (CP), 56 mg/kg ip to CBA/J mice effected the induction of prostaglandin E2 (PGE2) producing macrophages (M phi) in the bone marrow and the spleen. Maximal release of PGE2 from M phi cultured in vitro with calcium ionophore A23187 for 2 h was reached by marrow M phi removed on 5 days after CP (450 ng/mg cell protein), and by splenic M phi 9 days after CP (400 ng/mg). Neither M phi population, however, yielded more than 6.0 ng/mg leukotriene C4. To assess ontogenic relationships mice were depleted of bone marrow and blood monocytes by ivmore » injection of the bone-seeking isotope, 89Sr. CP was given at several points before or after bone marrow cell depletion. PGE2 production by splenic M phi harvested on day 9 after CP was profoundly impaired when CP was administered either concurrently with or 3 days after 89Sr. When CP was administered 1, 3, 5, and 7 days before 89Sr, however, the induction of PGE2-producing M phi in the spleen was unaffected. To determine whether bone marrow cells from CP-injected donors can restore PGE2-producing splenic M phi (PGSM) in 89Sr-mice, recipient mice which had and had not received CP 3 days after 89Sr were transfused with 5 x 10(6) syngeneic bone marrow cells from donor mice prepared at varying intervals after CP administration. The results clearly indicate the capacity of bone marrow cells harvested on either day 1 or 2 following CP to restore PGSM in CP-primed, but not unprimed, recipients.« less

  12. Inhibition of microsomal prostaglandin E2 synthase-1 as a molecular basis for the anti-inflammatory actions of boswellic acids from frankincense.

    PubMed

    Siemoneit, U; Koeberle, A; Rossi, A; Dehm, F; Verhoff, M; Reckel, S; Maier, T J; Jauch, J; Northoff, H; Bernhard, F; Doetsch, V; Sautebin, L; Werz, O

    2011-01-01

    Frankincense, the gum resin derived from Boswellia species, showed anti-inflammatory efficacy in animal models and in pilot clinical studies. Boswellic acids (BAs) are assumed to be responsible for these effects but their anti-inflammatory efficacy in vivo and their molecular modes of action are incompletely understood. A protein fishing approach using immobilized BA and surface plasmon resonance (SPR) spectroscopy were used to reveal microsomal prostaglandin E(2) synthase-1 (mPGES1) as a BA-interacting protein. Cell-free and cell-based assays were applied to confirm the functional interference of BAs with mPGES1. Carrageenan-induced mouse paw oedema and rat pleurisy models were utilized to demonstrate the efficacy of defined BAs in vivo. Human mPGES1 from A549 cells or in vitro-translated human enzyme selectively bound to BA affinity matrices and SPR spectroscopy confirmed these interactions. BAs reversibly suppressed the transformation of prostaglandin (PG)H(2) to PGE(2) mediated by mPGES1 (IC(50) = 3-10 µM). Also, in intact A549 cells, BAs selectively inhibited PGE(2) generation and, in human whole blood, β-BA reduced lipopolysaccharide-induced PGE(2) biosynthesis without affecting formation of the COX-derived metabolites 6-keto PGF(1α) and thromboxane B(2) . Intraperitoneal or oral administration of β-BA (1 mg·kg(-1) ) suppressed rat pleurisy, accompanied by impaired levels of PGE(2) and β-BA (1 mg·kg(-1) , given i.p.) also reduced mouse paw oedema, both induced by carrageenan. Suppression of PGE(2) formation by BAs via interference with mPGES1 contribute to the anti-inflammatory effectiveness of BAs and of frankincense, and may constitute a biochemical basis for their anti-inflammatory properties. © 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society.

  13. Decoy Wnt receptor (sLRP6E1E2)-expressing adenovirus induces anti-fibrotic effect via inhibition of Wnt and TGF-β signaling.

    PubMed

    Lee, Won Jai; Lee, Jung-Sun; Ahn, Hyo Min; Na, Youjin; Yang, Chae Eun; Lee, Ju Hee; Hong, JinWoo; Yun, Chae-Ok

    2017-11-08

    Aberrant activation of the canonical Wingless type (Wnt) signaling pathway plays a key role in the development of hypertrophic scars and keloids, and this aberrant activation of Wnt pathway can be a potential target for the development of novel anti-fibrotic agents. In this study, we evaluated the anti-fibrotic potential of a soluble Wnt decoy receptor (sLRP6E1E2)-expressing non-replicating adenovirus (Ad; dE1-k35/sLRP6E1E2) on human dermal fibroblasts (HDFs), keloid fibroblasts (KFs), and keloid tissue explants. Higher Wnt3a and β-catenin expression was observed in the keloid region compared to the adjacent normal tissues. The activity of β-catenin and mRNA expression of type-I and -III collagen were significantly decreased following treatment with dE1-k35/sLRP6E1E2 in HDFs and KFs. The expression of LRP6, β-catenin, phosphorylated glycogen synthase kinase 3 beta, Smad 2/3 complex, and TGF-β1 were decreased in Wnt3a- or TGF-β1-activated HDFs, following administration of dE1-k35/sLRP6E1E2. Moreover, dE1-k35/sLRP6E1E2 markedly inhibited nuclear translocation of both β-catenin and Smad 2/3 complex. The expression levels of type-I and -III collagen, fibronectin, and elastin were also significantly reduced in keloid tissue explants after treatment with dE1-k35/sLRP6E1E2. These results indicate that Wnt decoy receptor-expressing Ad can degrade extracellular matrix in HDFs, KFs, and primary keloid tissue explants, and thus it may be beneficial for treatment of keloids.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cherukuri, Durga Prasad; Chen, Xiao B.O.; Goulet, Anne-Christine

    Accumulating evidence indicates that elevated levels of prostaglandin E{sub 2} (PGE{sub 2}) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE{sub 2} exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE{sub 2} to stimulate cell proliferation of human colon cancer cells. However, the EP receptor(s) that are involved in this process remain unknown. We provide evidence that L-161,982, a selective EP4 receptor antagonist, completely blocks PGE{sub 2}-induced ERK phosphorylation and cell proliferation of HCA-7 cells.more » In order to identify downstream target genes of ERK1/2 signaling, we found that PGE{sub 2} induces expression of early growth response gene-1 (EGR-1) downstream of ERK1/2 and regulates its expression at the level of transcription. PGE{sub 2} treatment induces phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 residue and CRE-mediated luciferase activity in HCA-7 cells. Studies with dominant-negative CREB mutant (ACREB) provide clear evidence for the involvement of CREB in PGE{sub 2} driven egr-1 transcription in HCA-7 cells. In conclusion, this study reveals that egr-1 is a target gene of PGE{sub 2} in HCA-7 cells and is regulated via the newly identified EP4/ERK/CREB pathway. Finally our results support the notion that antagonizing EP4 receptors may provide a novel therapeutic approach to the treatment of colon cancer.« less

  15. Prostaglandin E2 Adds Bone to a Cancellous Bone Site with a Closed Growth Plate and Low Bone Turnover in Ovariectomized Rats

    NASA Technical Reports Server (NTRS)

    Ma, Y. F.; Ke, H. Z.; Jee, W. S. S.

    1994-01-01

    The objects of this study were to determine the responses of a cancellous bone site with a closed growth plate, (the distal tibial metaphysis (DTM), to ovariectomy (OVX) and OVX plus a prostaglandin E(2) treatment, and compare the site's response to previous findings reported for another site, the proximal tibial metaphysis (PTM). Thirty five 3-month old female Sprague-Dawley rats were divided into five groups; basal, sham OVX, and OVX+0, +1, or +6 mg PGE(2)/kg/d injected subcutaneously for 3 months and given double fluorescent labels before sacrifice. Cancellous bone histomorphometric analyses were performed on 20 micrometer thick undecalcified DTM sections. Similar to the PTM, the DTM showed age-related decreases in bone formation and increases in bone resorption, but it differed in that at 3 months POST OVX there was neither bone loss nor changes in formation endpoints. Giving 1 mg PGE(2)/kg/d to OVX rats prevented most age-related changes and maintained the bone formation histomorphometry near basal levels. Treating OVX rats with 6 mg PGE(2)/kd/d prevented age-related bone changes, added extra bone, and improved microanatomical structure by stimulating bone formation, without altering bone resportion. Futhermore, After PGE(2) admimnistration, the DTM, a cancellous bone site with a closed growth plate, increased bone formation more than did the cancellous bone in the PTM.

  16. Histamine H2 receptor trafficking: role of arrestin, dynamin, and clathrin in histamine H2 receptor internalization.

    PubMed

    Fernandez, Natalia; Monczor, Federico; Baldi, Alberto; Davio, Carlos; Shayo, Carina

    2008-10-01

    Agonist-induced internalization of G protein-coupled receptors (GPCRs) has been implicated in receptor desensitization, resensitization, and down-regulation. In the present study, we sought to establish whether the histamine H2 receptor (H2r) agonist amthamine, besides promoting receptor desensitization, induced H2r internalization. We further studied the mechanisms involved and its potential role in receptor resensitization. In COS7 transfected cells, amthamine induced H2r time-dependent internalization, showing 70% of receptor endocytosis after 60-min exposure to amthamine. Agonist removal led to the rapid recovery of resensitized receptors to the cell surface. Similar results were obtained in the presence of cycloheximide, an inhibitor of protein synthesis. Treatment with okadaic acid, an inhibitor of the protein phosphatase 2A (PP2A) family of phosphatases, reduced the recovery of both H2r membrane sites and cAMP response. Arrestin 3 but not arrestin 2 overexpression reduced both H2r membrane sites and H2r-evoked cAMP response. Receptor cotransfection with dominant-negative mutants for arrestin, dynamin, Eps15 (a component of the clathrin-mediated endocytosis machinery), or RNA interference against arrestin 3 abolished both H2r internalization and resensitization. Similar results were obtained in U937 cells endogenously expressing H2r. Our findings suggest that amthamine-induced H2r internalization is crucial for H2r resensitization, processes independent of H2r de novo synthesis but dependent on PP2A-mediated dephosphorylation. Although we do not provide direct evidence for H2r interaction with beta-arrestin, dynamin, and/or clathrin, our results support their involvement in H2r endocytosis. The rapid receptor recycling to the cell surface and the specific involvement of arrestin 3 in receptor internalization further suggest that the H2r belongs to class A GPCRs.

  17. Modulation of E2F activity in primary mouse B cells following stimulation via surface IgM and CD40 receptors.

    PubMed

    Lam, E W; Glassford, J; van der Sman, J; Banerji, L; Pizzey, A R; Shaun, N; Thomas, B; Klaus, G G

    1999-10-01

    Since signals via CD40 and the B cell receptor are known to synergize to induce B cell activation, we have analyzed the pocket protein/E2F complexes in mouse B lymphocytes following stimulation by anti-IgM, anti-CD40, alone or together. We find that E2F4 and DP1 form the predominant E2F heterodimers in the G0 and G1 phases of the cell cycle, complexed with hypophosphorylated p130. During late G1 and S phase this complex is replaced by at least three different E2F complexes, one of which is an E2F complex containing p107 or pRB as well as two "free" E2F complexes consisting of E2F4/DP1 and E2F1-3/DP1. These effects were mirrored by the levels and phosphorylation status of the three pocket proteins. We also observed an increase in electrophoretic mobility of DP1 and E2F4 as B cells progressed from G0 into early G1, resulting from their dephosphorylation. This is known to correlate with a decrease in DNA binding capacity of these proteins and could also be important for derepression of genes negatively regulated through E2F sites in their promoters. These results therefore indicate that the pRB/E2F pathway integrates proliferative signals emanating from the sIgM and CD40 receptors.

  18. CJ-023,423, a novel, potent and selective prostaglandin EP4 receptor antagonist with antihyperalgesic properties.

    PubMed

    Nakao, Kazunari; Murase, Akio; Ohshiro, Hiroyuki; Okumura, Takako; Taniguchi, Kana; Murata, Yoko; Masuda, Masatoshi; Kato, Tomoki; Okumura, Yoshiyuki; Takada, Junji

    2007-08-01

    The prostaglandin (PG) EP(4) receptor subtype is expressed by peripheral sensory neurons. Although a potential role of EP(4) receptor in pain has been suggested, a limited number of selective ligands have made it difficult to explore the physiological functions of EP(4) or its potential as a new analgesic target. Here, we describe the in vitro and in vivo pharmacology of a novel EP(4) receptor antagonist, N-[({2-[4-(2-ethyl-4,6-dimethyl-1H-imidazo [4,5-c] pyridin-1-yl) phenyl]ethyl}amino) carbonyl]-4-methylbenzenesulfonamide (CJ-023,423). In vitro, CJ-023,423 inhibits [(3)H]PGE(2) binding to both human and rat EP(4) receptors with K(i) of 13 +/- 4 and 20 +/- 1 nM, respectively. CJ-023,423 is highly selective for the human EP(4) receptor over other human prostanoid receptor subtypes. It also inhibits PGE(2)-evoked elevation in intracellular cAMP at the human and rat EP(4) receptors with pA(2) of 8.3 +/- 0.03 and 8.2 +/- 0.2 nM, respectively. In vivo, oral administration of CJ-023,423 significantly reduces thermal hyperalgesia induced by intraplantar injection of PGE(2) (ED(50) = 12.8 mg/kg). CJ-023,423 is also effective in models of acute and chronic inflammatory pain. CJ-023,423 significantly reduces mechanical hyperalgesia in the carrageenan model. Furthermore, CJ-023,423 significantly reverses complete Freund's adjuvant-induced chronic inflammatory pain response. Taken together, the present data indicate that CJ-023,423, a highly potent and selective antagonist of both human and rat EP(4) receptors, produces antihyperalgesic effects in animal models of inflammatory pain. Thus, specific blockade of the EP(4) receptor signaling may represent a novel therapeutic approach for the treatment of inflammatory pain.

  19. Adenosine-A1 Receptor Agonist Induced Hyperalgesic Priming Type II

    PubMed Central

    Araldi, Dioneia; Ferrari, Luiz F.; Levine, Jon D.

    2016-01-01

    We have recently shown that repeated exposure of the peripheral terminal of the primary afferent nociceptor to the mu-opioid receptor (MOR) agonist DAMGO ([D-Ala2, N-Me-Phe4, Gly5-ol]-Enkephalin acetate salt) induces a model of the transition to chronic pain that we have termed Type II hyperalgesic priming. Similar to Type I hyperalgesic priming, there is a markedly prolonged response to subsequent administration of proalgesic cytokines, prototypically prostaglandin E2 (PGE2). However, Type II hyperalgesic priming differs from Type I in being rapidly induced, protein kinase A (PKA), rather than PKCε dependent, not reversed by a protein translation inhibitor, occurring in female as well as in male rats, and isolectin B4-negative neuron dependent. We report that as with the repeated injection of a MOR agonist, the repeated administration of an agonist at the A1-adenosine receptor, also a Gi-protein coupled receptor, N6-Cyclopentyladenosine (CPA), also produces priming similar to DAMGO-induced Type II hyperalgesic priming. In this study we demonstrate that priming induced by repeated exposure to this A1-adenosine receptor agonist shares the same mechanisms as MOR-agonist induced priming. However, the prolongation of PGE2 hyperalgesia induced by repeated administration of CPA depends on G-protein αi subunit activation, differently from DAMGO-induced Type II priming, in which it depends on the β/γ subunit. These data implicate a novel form of Gi-protein signaling pathway in the Type II hyperalgesic priming induced by repeated administration of an agonist at A1-adenosine receptor to the peripheral terminal of the nociceptor. PMID:26588695

  20. Interaction of PGHS-2 and glutamatergic mechanisms controlling the ovine fetal hypothalamus-pituitary-adrenal axis

    PubMed Central

    Knutson, Nathan

    2010-01-01

    Prostaglandins, generated within the fetal brain, are integral components of the mechanism controlling the fetal hypothalamus-pituitary-adrenal (HPA) axis. Previous studies in this laboratory demonstrated that prostaglandin G/H synthase isozyme 2 (PGHS-2) inhibition reduces the fetal HPA axis response to cerebral hypoperfusion, blocks the preparturient rise in fetal plasma ACTH concentration, and delays parturition. We also discovered that blockade of N-methyl-d-aspartate (NMDA) receptors reduces the fetal ACTH response to cerebral hypoperfusion. The present study was designed to test the hypothesis that PGHS-2 action and the downstream effect of HPA axis stimulation are stimulated by NMDA-mediated glutamatergic neurotransmission. Chronically catheterized late-gestation fetal sheep (n = 8) were injected with NMDA (1 mg iv). All responded with increases in fetal plasma ACTH and cortisol concentrations. Pretreatment with resveratrol (100 mg iv, n = 5), a specific inhibitor of PGHS-1, did not alter the magnitude of the HPA axis response to NMDA. Pretreatment with nimesulide (10 mg iv, n = 6), a specific inhibitor of PGHS-2, significantly reduced the HPA axis response to NMDA. To further explore this interaction, we injected NMDA in six chronically catheterized fetal sheep that were chronically infused with nimesulide (n = 6) at a rate of 1 mg/day into the lateral cerebral ventricle for 5–7 days. In this group, there was no significant ACTH response to NMDA. Finally, we tested whether the HPA axis response to prostaglandin E2 (PGE2) is mediated by NMDA receptors. Seven chronically catheterized late-gestation fetal sheep were injected with 100 ng of PGE2, which significantly increased fetal plasma ACTH and cortisol concentrations. Pretreatment with ketamine (10 mg iv), an NMDA antagonist, did not alter the ACTH or cortisol response to PGE2. We conclude that generation of prostanoids via the action of PGHS-2 in the fetal brain augments the fetal HPA axis response to

  1. Cyclooxygenases, microsomal prostaglandin E synthase-1, and cardiovascular function

    PubMed Central

    Cheng, Yan; Wang, Miao; Yu, Ying; Lawson, John; Funk, Colin D.; FitzGerald, Garret A.

    2006-01-01

    We investigated the mechanisms by which inhibitors of prostaglandin G/H synthase-2 (PGHS-2; known colloquially as COX-2) increase the incidence of myocardial infarction and stroke. These inhibitors are believed to exert both their beneficial and their adverse effects by suppression of PGHS-2–derived prostacyclin (PGI2) and PGE2. Therefore, the challenge remains to identify a mechanism whereby PGI2 and PGE2 expression can be suppressed while avoiding adverse cardiovascular events. Here, selective inhibition, knockout, or mutation of PGHS-2, or deletion of the receptor for PGHS-2–derived PGI2, was shown to accelerate thrombogenesis and elevate blood pressure in mice. These responses were attenuated by COX-1 knock down, which mimics the beneficial effects of low-dose aspirin. PGE2 biosynthesis is catalyzed by the coordinate actions of COX enzymes and microsomal PGE synthase-1 (mPGES-1). We show that deletion of mPGES-1 depressed PGE2 expression, augmented PGI2 expression, and had no effect on thromboxane biosynthesis in vivo. Most importantly, mPGES-1 deletion affected neither thrombogenesis nor blood pressure. These results suggest that inhibitors of mPGES-1 may retain their antiinflammatory efficacy by depressing PGE2, while avoiding the adverse cardiovascular consequences associated with PGHS-2–mediated PGI2 suppression. PMID:16614756

  2. The relevance of kalikrein-kinin system via activation of B2 receptor in LPS-induced fever in rats.

    PubMed

    Soares, Denis de Melo; Santos, Danielle R; Rummel, Christoph; Ott, Daniela; Melo, Míriam C C; Roth, Joachim; Calixto, João B; Souza, Glória E P

    2017-11-01

    This study evaluated the involvement of endogenous kallikrein-kinin system and the bradykinin (BK) B 1 and B 2 receptors on LPS- induced fever and the POA cells involved in this response. Male Wistar rats received either i.v. (1 mg/kg), i.c.v. (20 nmol) or i.h. (2 nmol) injections of icatibant (B 2 receptor antagonist) 30 or 60 min, respectively, before the stimuli. DALBK (B 1 receptor antagonist) was given either 15min before BK (i.c.v.) or 30 min before LPS (i.v.). Captopril (5 mg/kg, sc.,) was given 1 h prior LPS or BK. Concentrations of BK and total kininogenon CSF, plasma and tissue kallikrein were evaluated. Rectal temperatures (rT) were assessed by telethermometry. Ca ++ signaling in POA cells was performed in rat pup brain tissue microcultures. Icatibant reduced LPS fever while, captopril exacerbated that response, an effect abolished by icatibant. Icatibant (i.h.) reduced fever to BK (i.h.) but not that induced by LPS (i.v.). BK increased intracellular calcium concentration in neurons and astrocytes. LPS increased levels of bradykinin, tissue kallikrein and total kininogen. BK (i.c.v.) increased rT and decreased tail skin temperature. Captopril potentiated BK-induced fever an effect abolished by icatibant. DALBK reduced the fever induced by BK. BK (i.c.v.) increased the CSF PGE 2 concentration. Effect abolished by indomethacin (i.p.). LPS activates endogenous kalikrein-kinin system leading to production of BK, which by acting on B 2 -receptors of POA cells causes prostaglandin synthesis that in turn produces fever. Thus, a kinin B 2 -receptor antagonist that enters into the brain could constitute a new and interesting strategy to treat fever. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Correlation of prostaglandin E2 concentrations in synovial fluid with ground reaction forces and clinical variables for pain or inflammation in dogs with osteoarthritis induced by transection of the cranial cruciate ligament.

    PubMed

    Trumble, Troy N; Billinghurst, R Clark; McIlwraith, C Wayne

    2004-09-01

    To evaluate the temporal pattern of prostaglandin (PG) E2 concentrations in synovial fluid after transection of the cranial cruciate ligament (CCL) in dogs and to correlate PGE2 concentrations with ground reaction forces and subjective clinical variables for lameness or pain. 19 purpose-bred adult male Walker Hounds. Force plate measurements, subjective clinical analysis of pain or lameness, and samples of synovial fluid were obtained before (baseline) and at various time points after arthroscopic transection of the right CCL. Concentrations of PGE2 were measured in synovial fluid samples, and the PGE2 concentrations were correlated with ground reaction forces and clinical variables. The PGE2 concentration increased significantly above the baseline value throughout the entire study, peaking 14 days after transection. Peak vertical force and vertical impulse significantly decreased by day 14 after transection, followed by an increase over time without returning to baseline values. All clinical variables (eg, lameness, degree of weight bearing, joint extension, cumulative pain score, effusion score, and total protein content of synovial fluid, except for WBC count in synovial fluid) increased significantly above baseline values. Significant negative correlations were detected between PGE2 concentrations and peak vertical force (r, -0.5720) and vertical impulse (r, -0.4618), and significant positive correlations were detected between PGE2 concentrations and the subjective lameness score (r, 0.5016) and effusion score (r, 0.6817). Assessment of the acute inflammatory process by measurement of PGE2 concentrations in synovial fluid may be correlated with the amount of pain or lameness in dogs.

  4. Reciprocal Cross Talk between Gonadotropin-Releasing Hormone (GnRH) and Prostaglandin Receptors Regulates GnRH Receptor Expression and Differential Gonadotropin Secretion

    PubMed Central

    Naor, Zvi; Jabbour, Henry N.; Naidich, Michal; Pawson, Adam J.; Morgan, Kevin; Battersby, Sharon; Millar, Michael R.; Brown, Pamela; Millar, Robert P.

    2007-01-01

    The asynchronous secretion of gonadotrope LH and FSH under the control of GnRH is crucial for ovarian cyclicity but the underlying mechanism is not fully resolved. Because prostaglandins (PG) are autocrine regulators in many tissues, we determined whether they have this role in gonadotropes. We first demonstrated that GnRH stimulates PG synthesis by induction of cyclooxygenase-2, via the protein kinase C/c-Src/phosphatidylinositol 3′-kinase/MAPK pathway in the LβT2 gonadotrope cell line. We then demonstrated that PGF2α and PGI2, but not PGE2 inhibited GnRH receptor expression by inhibition of phosphoinositide turnover. PGF2α, but not PGI2 or PGE2, reduced GnRH-induction of LHβ gene expression, but not the α-gonadotropin subunit or the FSHβ subunit genes. The prostanoid receptors EP1, EP2, FP, and IP were expressed in rat gonadotropes. Incubations of rat pituitaries with PGF2α, but not PGI2 or PGE2, inhibited GnRH-induced LH secretion, whereas the cyclooxygenase inhibitor, indomethacin, stimulated GnRH-induced LH secretion. None of these treatments had any effect on GnRH-induced FSH secretion. The findings have thus elaborated a novel GnRH signaling pathway mediated by PGF2α-FP and PGI2-IP, which acts through an autocrine/paracrine modality to limit autoregulation of the GnRH receptor and differentially inhibit LH and FSH release. These findings provide a mechanism for asynchronous LH and FSH secretions and suggest the use of combination therapies of GnRH and prostanoid analogs to treat infertility, diseases with unbalanced LH and FSH secretion and in hormone-dependent diseases such as prostatic cancer. PMID:17138645

  5. Adenosine A2A receptors and depression.

    PubMed

    El Yacoubi, Malika; Costentin, Jean; Vaugeois, Jean-Marie

    2003-12-09

    Adenosine and its analogues have been shown to induce "behavioral despair" in animal models believed to be relevant to depression. Recent data have shown that selective adenosine A2A receptor antagonists (e.g., SCH 58261, ZM241385, and KW6002) or genetic inactivation of the receptor was effective in reversing signs of behavioral despair in the tail suspension and forced swim tests, two screening procedures predictive of antidepressant activity. A2A antagonists were active in the tail suspension test using either mice previously screened for having high immobility scores or mice that were selectively bred for their spontaneous "helplessness" in this test. At stimulant doses, caffeine, a nonselective A1/A2A receptor antagonist, was effective in the forced swim test. The authors have hypothesized that the antidepressant-like effect of selective A2A antagonists is linked to an interaction with dopaminergic transmission, possibly in the frontal cortex. In support of this idea, administration of the dopamine D2 receptor antagonist haloperidol prevented antidepressant-like effects elicited by SCH 58261 in the forced swim test (putatively involving cortex), whereas it had no effect on stimulant motor effects of SCH 58261 (putatively linked to ventral striatum). The interaction profile of caffeine with haloperidol differed markedly from that of SCH 58261 in the forced swim and motor activity tests. Therefore, a clear-cut antidepressant-like effect could not be ascribed to caffeine. In conclusion, available data support the proposition that a selective blockade of the adenosine A2A receptor may be an interesting target for the development of effective antidepressant agents.

  6. Agonists and antagonists for P2 receptors

    PubMed Central

    Jacobson, Kenneth A.; Costanzi, Stefano; Joshi, Bhalchandra V.; Besada, Pedro; Shin, Dae Hong; Ko, Hyojin; Ivanov, Andrei A.; Mamedova, Liaman

    2015-01-01

    Recent work has identified nucleotide agonists selective for P2Y1, P2Y2 and P2Y6 receptors and nucleotide antagonists selective for P2Y1, P2Y12 and P2X1 receptors. Selective non-nucleotide antagonists have been reported for P2Y1, P2Y2, P2Y6, P2Y12, P2Y13, P2X2/3/P2X3 and P2X7 receptors. For example, the dinucleotide INS 37217 (Up4dC) potently activates the P2Y2 receptor, and the non-nucleotide antagonist A-317491 is selective for P2X2/3/P2X3 receptors. Nucleotide analogues in which the ribose moiety is substituted by a variety of novel ring systems, including conformation-ally locked moieties, have been synthesized as ligands for P2Y receptors. The focus on conformational factors of the ribose-like moiety allows the inclusion of general modifications that lead to enhanced potency and selectivity. At P2Y1,2,4,11 receptors, there is a preference for the North conformation as indicated with (N)-methanocarba analogues. The P2Y1 antagonist MRS2500 inhibited ADP-induced human platelet aggregation with an IC50 of 0.95 nM. MRS2365, an (N)-methanocarba analogue of 2-MeSADP, displayed potency (EC50) of 0.4 nM at the P2Y1 receptor, with >10 000-fold selectivity in comparison to P2Y12 and P2Y13 receptors. At P2Y6 receptors there is a dramatic preference for the South conformation. Three-dimensional structures of P2Y receptors have been deduced from structure activity relationships (SAR), mutagenesis and modelling studies. Detailed three-dimensional structures of P2X receptors have not yet been proposed. PMID:16805423

  7. Functionalized Congeners of P2Y1 Receptor Antagonists:

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    de Castro, Sonia; Maruoka, Hiroshi; Hong, Kunlun

    2010-01-01

    The P2Y{sub 1} receptor is a prothrombotic G protein-coupled receptor (GPCR) activated by ADP. Preference for the North (N) ring conformation of the ribose moiety of adenine nucleotide 3',5'-bisphosphate antagonists of the P2Y{sub 1} receptor was established by using a ring-constrained methanocarba (a bicyclo[3.1.0]hexane) ring as a ribose substitute. A series of covalently linkable N{sup 6}-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphates containing extended 2-alkynyl chains was designed, and binding affinity at the human (h) P2Y{sub 1} receptor determined. The chain of these functionalized congeners contained hydrophilic moieties, a reactive substituent, or biotin, linked via an amide. Variation of the chain length and position of anmore » intermediate amide group revealed high affinity of carboxylic congener 8 (K{sub i} 23 nM) and extended amine congener 15 (K{sub i} 132 nM), both having a 2-(1-pentynoyl) group. A biotin conjugate 18 containing an extended {epsilon}-aminocaproyl spacer chain exhibited higher affinity than a shorter biotinylated analogue. Alternatively, click coupling of terminal alkynes of homologous 2-dialkynyl nucleotide derivatives to alkyl azido groups produced triazole derivatives that bound to the P2Y{sub 1} receptor following deprotection of the bisphosphate groups. The preservation of receptor affinity of the functionalized congeners was consistent with new P2Y{sub 1} receptor modeling and ligand docking. Attempted P2Y{sub 1} antagonist conjugation to PAMAM dendrimer carriers by amide formation or palladium-catalyzed reaction between an alkyne on the dendrimer and a 2-iodopurine-derivatized nucleotide was unsuccessful. A dialkynyl intermediate containing the chain length favored in receptor binding was conjugated to an azide-derivatized dendrimer, and the conjugate inhibited ADP-promoted human platelet aggregation. This is the first example of attaching a strategically functionalized P2Y receptor antagonist to a PAMAM

  8. Losartan reverses COX-2-dependent vascular dysfunction in offspring of hyperglycaemic rats.

    PubMed

    de Queiroz, Diego Barbosa; Ramos-Alves, Fernanda Elizabethe; Santos-Rocha, Juliana; Duarte, Gloria Pinto; Xavier, Fabiano Elias

    2017-09-01

    This study examined whether chronic treatment with losartan, an angiotensin II type 1 receptor (AT 1 R) antagonist, might reverse COX-2-mediated vascular dysfunction in mesenteric resistance arteries (MRA) from offspring of hyperglycaemic rats. Male 12-month-old offspring of hyperglycaemic (O-DR) and normoglycaemic (O-CR) rats were treated with losartan (15mg·kg·day -1 ) during 2months. Third order MRA of untreated and losartan-treated O-DR and O-CR were mounted in wire myograph for isometric tension measurements. COX-2 expression was analyzed by Western blot; TxA 2 , PGE 2 and PGF 2α release was measured using commercial kits. O-DR showed increased blood pressure, impaired acetylcholine-induced vasodilation and increased noradrenaline-induced vasoconstriction than O-CR. All these parameters were normalized by losartan in O-DR. Pre-incubation of MRA with indomethacin (COX-1/2 inhibitor), NS-398 (COX-2 inhibitor) or tempol (superoxide dismutase mimetic) increased relaxation to acetylcholine and reduced contraction to noradrenaline only in O-DR. COX-2 expression, TxA 2 , PGE 2 and PGF 2α release were increased in O-DR. In losartan-treated O-DR, NS-398, indomethacin or tempol failed to produce any effect on acetylcholine or noradrenaline responses. Losartan treatment reduced COX-2 expression, TxA 2 , PGE 2 and PGF 2α release in O-DR. The present results reveal that chronic losartan administration in O-DR normalizes endothelial function in MRA by correcting the existing COX-2 overexpression and the imbalance between endothelium-derived relaxing and contracting factors. These findings not only support the beneficial effects of AT 1 receptor antagonist in O-DR, but also suggest the implication of angiotensin II as a putative mediator of hyperglycemia-programmed vascular dysfunction in rats. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Depleted nitric oxide and prostaglandin E2 levels are correlated with endothelial dysfunction in β-thalassemia/HbE patients.

    PubMed

    Satitthummanid, Sudarat; Uaprasert, Noppacharn; Songmuang, Smonporn Boonyaratavej; Rojnuckarin, Ponlapat; Tosukhowong, Piyaratana; Sutcharitchan, Pranee; Srimahachota, Suphot

    2017-09-01

    Mechanisms of vascular disorders in β-thalassemia/HbE patients remain poorly understood. In the present study, we aimed to determine the presence of endothelial dysfunction and its association with altered vascular mediators in this population. Forty-three β-thalassemia/HbE patients without clinically documented vascular symptoms and 43 age-sex-matched healthy controls were enrolled. Endothelial function was assessed using flow-mediated dilatation (FMD) before and after administration of nitroglycerine (NTG). β-Thalassemia/HbE patients showed a significant endothelial dysfunction using FMD. The percentage change in the brachial artery diameter before NTG was significantly lower in the thalassemia group compared to the control (5.0 ± 5.9 vs. 9.0 ± 4.0%, p < 0.01) while no significant differences after NTG (18.4 ± 8.3 vs. 17.8 ± 6.3%, p = 0.71). Plasma nitric oxide metabolites (NO x ) and prostaglandin E 2 (PGE 2 ) levels were significantly decreased in β-thalassemia/HbE (117.2 ± 27.3 vs. 135.8 ± 11.3 µmol/L, p < 0.01) and (701.9 ± 676.0 vs. 1374.7 ± 716.5 pg/mL, p < 0.01), respectively, while a significant elevation in soluble thrombomodulin levels in β-thalassemia/HbE (3587.7 ± 1310.0 vs. 3093.9 ± 583.8 pg/mL, p = 0.028). NO x and PGE 2 levels were significantly correlated with FMD (r = 0.27, p = 0.025) and (r = 0.35, p = 0.003), respectively. These findings suggest roles for endothelial mediators and a new mechanism underlying endothelial dysfunction in β-thalassemia/HbE patients.

  10. Possible role of IGF2 receptors in regulating selection of 2 dominant follicles in cattle selected for twin ovulations and births

    USDA-ARS?s Scientific Manuscript database

    Abundance of IGF-2 receptor (IGF2R), FSH receptor (FSHR), and LH receptor (LHCGR) mRNA in granulosa cells (GCs) or theca cells (TCs) or both cells as well as estradiol (E2), progesterone (P4), and androstenedione concentrations in follicular fluid were compared in cows genetically selected (Twinner)...

  11. Loops D, E and G in the Drosophila Dα1 subunit contribute to high neonicotinoid sensitivity of Dα1-chicken β2 nicotinic acetylcholine receptor.

    PubMed

    Ihara, Makoto; Hikida, Mai; Matsushita, Hiroyuki; Yamanaka, Kyosuke; Kishimoto, Yuya; Kubo, Kazuki; Watanabe, Shun; Sakamoto, Mifumi; Matsui, Koutaro; Yamaguchi, Akihiro; Okuhara, Daiki; Furutani, Shogo; Sattelle, David B; Matsuda, Kazuhiko

    2018-06-01

    Neonicotinoid insecticides interact with the orthosteric site formed at subunit interfaces of insect nicotinic ACh (nACh) receptors. However, their interactions with the orthosteric sites at α-non α and α-α subunit interfaces remain poorly understood. The aim of this study was to elucidate the mechanism of neonicotinoid actions using the Drosophila Dα1-chicken β2 hybrid nACh receptor. Computer models of the (Dα1) 3 (β2) 2 nACh receptor in complex with imidacloprid and thiacloprid were generated. Amino acids in the Dα1 subunit were mutated to corresponding amino acids in the human α4 subunit to examine their effects on the agonist actions of neonicotinoids on (Dα1) 3 (β2) 2 and (Dα1) 22) 3 nACh receptors expressed in Xenopus laevis oocytes using voltage-clamp electrophysiology. The (Dα1) 3 (β2) 2 nACh receptor models indicated that amino acids in loops D, E and G probably determine the effects of neonicotinoids. The amino acid mutations tested had minimal effects on the EC 50 for ACh. However, the R57S mutation in loop G, although having minimal effect on imidacloprid's actions, reduced the affinity of thiacloprid for the (Dα1) 3 (β2) 2 nACh receptor, while scarcely affecting thiacloprid's action on the (Dα1) 22) 3 nACh receptor. Both the K140T and the combined R57S;K140T mutations reduced neonicotinoid efficacy but only for the (Dα1) 3 (β2) 2 nACh receptor. Combining the E78K mutation with the R57S;K140T mutations resulted in a selective reduction of thiacloprid's affinity for the (Dα1) 3 (β2) 2 nACh receptor. These findings suggest that a triangle of residues from loops D, E and G contribute to the selective actions of neonicotinoids on insect-vertebrate hybrid nACh receptors. This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc. © 2017 The British Pharmacological Society.

  12. Prostaglandin receptors EP1-4 as a potential marker for clinical outcome in urothelial bladder cancer.

    PubMed

    von der Emde, Laura; Goltz, Diane; Latz, Stefan; Müller, Stefan C; Kristiansen, Glen; Ellinger, Jörg; Syring, Isabella

    2014-01-01

    Prostaglandins, especially prostaglandin E2 (PGE2), and COX-2 play an important role in carcinogenesis of many tumors including bladder cancer (BCA). The PGE2 receptors EP1-4 regulate tumor cell growth, invasion and migration in different tumor entities but EP expression in BCA remains to be determined. In the present study we examined the expression of EP1-4 in non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC) and normal urothelial tissue (NU) using immunohistochemistry. Nuclear and cytoplasmic EP1-4 expression was correlated with clinicopathological parameters and survival of BCA patients. EP1, EP2 and EP3 were significantly less expressed in the cytoplasm und nucleus of NMIBC and MIBC than in NU; EP4 cytoplasmic staining in MIBC was significantly higher compared to NU. The cytoplasmic staining was significantly more abundant in MIBC than in NMIBC in all investigated receptors except EP2. The level of EP staining in NMIBC was correlated with staging and grading, especially cytoplasmic EP1. Nuclear staining of EP1 was an independent predictor of BCA recurrence-free survival in NMIBC patients. EP receptors are dysregulated in BCA. The increase of EP1 may be used as prognostic parameter in NMIBC patients and its dysregulation could be targeted by specific EP1 inhibitors.

  13. Prostaglandin receptors EP1-4 as a potential marker for clinical outcome in urothelial bladder cancer

    PubMed Central

    von der Emde, Laura; Goltz, Diane; Latz, Stefan; Müller, Stefan C; Kristiansen, Glen; Ellinger, Jörg; Syring, Isabella

    2014-01-01

    Prostaglandins, especially prostaglandin E2 (PGE2), and COX-2 play an important role in carcinogenesis of many tumors including bladder cancer (BCA). The PGE2 receptors EP1-4 regulate tumor cell growth, invasion and migration in different tumor entities but EP expression in BCA remains to be determined. In the present study we examined the expression of EP1-4 in non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC) and normal urothelial tissue (NU) using immunohistochemistry. Nuclear and cytoplasmic EP1-4 expression was correlated with clinicopathological parameters and survival of BCA patients. EP1, EP2 and EP3 were significantly less expressed in the cytoplasm und nucleus of NMIBC and MIBC than in NU; EP4 cytoplasmic staining in MIBC was significantly higher compared to NU. The cytoplasmic staining was significantly more abundant in MIBC than in NMIBC in all investigated receptors except EP2. The level of EP staining in NMIBC was correlated with staging and grading, especially cytoplasmic EP1. Nuclear staining of EP1 was an independent predictor of BCA recurrence-free survival in NMIBC patients. EP receptors are dysregulated in BCA. The increase of EP1 may be used as prognostic parameter in NMIBC patients and its dysregulation could be targeted by specific EP1 inhibitors. PMID:25520883

  14. Expression and Role of Gonadotropin-Releasing Hormone 2 and Its Receptor in Mammals

    PubMed Central

    Desaulniers, Amy T.; Cederberg, Rebecca A.; Lents, Clay A.; White, Brett R.

    2017-01-01

    Gonadotropin-releasing hormone 1 (GnRH1) and its receptor (GnRHR1) drive mammalian reproduction via regulation of the gonadotropins. Yet, a second form of GnRH (GnRH2) and its receptor (GnRHR2) also exist in mammals. GnRH2 has been completely conserved throughout 500 million years of evolution, signifying high selection pressure and a critical biological role. However, the GnRH2 gene is absent (e.g., rat) or inactivated (e.g., cow and sheep) in some species but retained in others (e.g., human, horse, and pig). Likewise, many species (e.g., human, chimpanzee, cow, and sheep) retain the GnRHR2 gene but lack the appropriate coding sequence to produce a full-length protein due to gene coding errors; although production of GnRHR2 in humans remains controversial. Certain mammals lack the GnRHR2 gene (e.g., mouse) or most exons entirely (e.g., rat). In contrast, old world monkeys, musk shrews, and pigs maintain the coding sequence required to produce a functional GnRHR2. Like GnRHR1, GnRHR2 is a 7-transmembrane, G protein-coupled receptor that interacts with Gαq/11 to mediate cell signaling. However, GnRHR2 retains a cytoplasmic tail and is only 40% homologous to GnRHR1. A role for GnRH2 and its receptor in mammals has been elusive, likely because common laboratory models lack both the ligand and receptor. Uniquely, both GnRH2 and GnRHR2 are ubiquitously expressed; transcript levels are abundant in peripheral tissues and scarcely found in regions of the brain associated with gonadotropin secretion, suggesting a divergent role from GnRH1/GnRHR1. Indeed, GnRH2 and its receptor are not physiological modulators of gonadotropin secretion in mammals. Instead, GnRH2 and GnRHR2 coordinate the interaction between nutritional status and sexual behavior in the female brain. Within peripheral tissues, GnRH2 and its receptor are novel regulators of reproductive organs. GnRH2 and GnRHR2 directly stimulate steroidogenesis within the porcine testis. In the female, GnRH2 and its receptor

  15. A simple and highly selective 2,2-diferrocenylpropane-based multi-channel ion pair receptor for Pb(2+) and HSO4(-).

    PubMed

    Wan, Qian; Zhuo, Ji-Bin; Wang, Xiao-Xue; Lin, Cai-Xia; Yuan, Yao-Feng

    2015-03-28

    A structurally simple, 2,2-diferrocenylpropane-based ion pair receptor 1 was synthesized and characterized by (1)H NMR, (13)C NMR, HRMS, elemental analyses, and single-crystal X-ray diffraction. The ion pair receptor 1 showed excellent selectivity and sensitivity towards Pb(2+) with multi-channel responses: a fluorescence enhancement (more than 42-fold), a notable color change from yellow to red, redox anodic shift (ΔE1/2 = 151 mV), while HSO4(-) promoted fluorescence enhancement when Pb(2+) or Zn(2+) was bonded to the cation binding-site. (1)H NMR titration and density functional theory were performed to reveal the sensing mechanism based on photo-induced electron transfer (PET).

  16. Oxidized Low-Density Lipoprotein Suppresses Expression of Prostaglandin E Receptor Subtype EP3 in Human THP-1 Macrophages

    PubMed Central

    Sui, Xuxia; Liu, Yanmin; Li, Qi; Liu, Gefei; Song, Xuhong; Su, Zhongjing; Chang, Xiaolan; Zhou, Yingbi; Liang, Bin; Huang, Dongyang

    2014-01-01

    EP3, one of four prostaglandin E2 (PGE2) receptors, is significantly lower in atherosclerotic plaques than in normal arteries and is localized predominantly in macrophages of the plaque shoulder region. However, mechanisms behind this EP3 expression pattern are still unknown. We investigated the underlying mechanism of EP3 expression in phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages with oxidized low-density lipoprotein (oxLDL) treatment. We found that oxLDL decreased EP3 expression, in a dose-dependent manner, at both the mRNA and protein levels. Moreover, oxLDL inhibited nuclear factor-κB (NF-κB)-dependent transcription of the EP3 gene by the activation of peroxisome proliferator-activated receptor-γ (PPAR-γ). Finally, chromatin immunoprecipitation revealed decreased binding of NF-κB to the EP3 promoter with oxLDL and PPAR-γ agonist treatment. Our results show that oxLDL suppresses EP3 expression by activation of PPAR-γ and subsequent inhibition of NF-κB in macrophages. These results suggest that down-regulation of EP3 expression by oxLDL is associated with impairment of EP3-mediated anti-inflammatory effects, and that EP3 receptor activity may exert a beneficial effect on atherosclerosis. PMID:25333975

  17. Excitatory amino acid receptors in the dorsomedial hypothalamus mediate prostaglandin-evoked thermogenesis in brown adipose tissue.

    PubMed

    Madden, C J; Morrison, S F

    2004-02-01

    We determined whether the dorsomedial hypothalamus (DMH) plays a role in the thermogenic, metabolic, and cardiovascular effects evoked by centrally administered PGE2. Microinjection of PGE2 (170 pmol/60 nl) into the medial preoptic area of the hypothalamus in urethane-chloralose-anesthetized, artificially ventilated rats increased brown adipose tissue (BAT) sympathetic nerve activity (SNA; +207 +/- 18% of control), BAT temperature (1.5 +/- 0.2 degrees C), expired CO2 (0.9 +/- 0.1%), heart rate (HR; 106 +/- 12 beats/min), and mean arterial pressure (22 +/- 4 mmHg). Within 5 min of subsequent bilateral microinjections of the GABAA receptor agonist muscimol (120 pmol.60 nl-1.side-1) or the ionotropic excitatory amino acid antagonist kynurenate (6 nmol.60 nl-1.side-1) into the DMH, the PGE2-evoked increases were, respectively, attenuated by 91 +/- 3% and 108 +/- 7% for BAT SNA, by 73 +/- 12% and 102 +/- 28% for BAT temperature, by 100 +/- 4% and 125 +/- 21% for expired CO2, by 72 +/- 11% and 70 +/- 16% for HR, and by 84 +/- 19% and 113 +/- 16% for mean arterial pressure. Microinjections outside the DMH within the dorsal hypothalamic area adjacent to the mamillothalamic tracts or within the ventromedial hypothalamus were less effective for attenuating the PGE2-evoked thermogenic, metabolic, and cardiovascular responses. These results demonstrate that activation of excitatory amino acid receptors within the DMH is necessary for the thermogenic, metabolic, and cardiovascular responses evoked by microinjection of PGE2 into the medial preoptic area.

  18. alpha 4 beta 2 subunit combination specific pharmacology of neuronal nicotinic acetylcholine receptors in N1E-115 neuroblastoma cells.

    PubMed

    Zwart, R; Abraham, D; Oortgiesen, M; Vijverberg, H P

    1994-08-22

    Pharmacological characteristics of native neuronal nicotinic acetylcholine receptor-mediated ion currents in mouse N1E-115 neuroblastoma cells have been investigated by superfusion of voltage clamped cells with known concentrations of the agonists acetylcholine, nicotine and cytisine, and the antagonists alpha-bungarotoxin and neuronal bungarotoxin. The sensitivity of the nicotinic acetylcholine receptor for agonists followed the agonist potency rank-order: nicotine approximately acetylcholine > cytisine. The EC50 values of acetylcholine and nicotine are 78 microM and 76 microM, respectively. Equal concentrations of acetylcholine and nicotine induce inward currents with approximately the same peak amplitude whereas cytisine induces much smaller inward currents. Acetylcholine-induced currents are unaffected by high concentrations of alpha-bungarotoxin. Conversely, at 10 and 90 nM neuronal bungarotoxin reduces the amplitude of the 1 mM acetylcholine-induced inward current to 47% and 11% of control values, respectively. Both the agonist potency rank-order and the differential sensitivity to snake toxins of nicotinic receptors in N1E-115 cells are consistent with the known pharmacological profile of alpha 4 beta 2 nicotinic receptors expressed in Xenopus oocytes and distinct from those of all other nicotinic acetylcholine receptors of known functional subunit compositions. All data indicate that the native nicotinic acetylcholine receptor in N1E-115 cells is an assembly of alpha 4 and beta 2 subunits, the putative major subtype of nicotinic acetylcholine receptor in the brain.

  19. Genetic deletion of COX-2 diminishes VEGF production in mouse retinal Müller cells.

    PubMed

    Yanni, Susan E; McCollum, Gary W; Penn, John S

    2010-07-01

    Non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit COX activity, reduce the production of retinal VEGF and neovascularization in relevant models of ocular disease. We hypothesized that COX-2 mediates VEGF production in retinal Müller cells, one of its primary sources in retinal neovascular disease. The purpose of this study was to determine the role of COX-2 and its products in VEGF expression and secretion. These studies have more clearly defined the role of COX-2 and COX-2-derived prostanoids in retinal angiogenesis. Müller cells derived from wild-type and COX-2 null mice were exposed to hypoxia for 0-24 h. COX-2 protein and activity were assessed by western blot analysis and GC-MS, respectively. VEGF production was assessed by ELISA. Wild-type mouse Müller cells were treated with vehicle (0.1% DMSO), 10 microM PGE(2), or PGE(2) + 5 microM H-89 (a PKA inhibitor), for 12 h. VEGF production was assessed by ELISA. Hypoxia significantly increased COX-2 protein (p < 0.05) and activity (p < 0.05), and VEGF production (p < 0.0003). COX-2 null Müller cells produced significantly less VEGF in response to hypoxia (p < 0.05). Of the prostanoids, PGE(2) was significantly increased by hypoxia (p < 0.02). Exogenous PGE(2) significantly increased VEGF production by Müller cells (p < 0.0039), and this effect was inhibited by H-89 (p < 0.055). These data demonstrate that hypoxia induces COX-2, prostanoid production, and VEGF synthesis in Müller cells, and that VEGF production is at least partially COX-2-dependent. Our study suggests that PGE(2), signaling through the EP(2) and/or EP(4) receptor and PKA, mediates the VEGF response of Müller cells. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice

    PubMed Central

    Otten, Jeroen J. T.; de Jager, Saskia C. A.; Kavelaars, Annemieke; Seijkens, Tom; Bot, Ilze; Wijnands, Erwin; Beckers, Linda; Westra, Marijke M.; Bot, Martine; Busch, Matthias; Bermudez, Beatriz; van Berkel, Theo J. C.; Heijnen, Cobi J.; Biessen, Erik A. L.

    2013-01-01

    Leukocyte chemotaxis is deemed instrumental in initiation and progression of atherosclerosis. It is mediated by G-protein-coupled receptors (e.g., CCR2 and CCR5), the activity of which is controlled by G-protein-coupled receptor kinases (GRKs). In this study, we analyzed the effect of hematopoietic deficiency of a potent regulator kinase of chemotaxis (GRK2) on atherogenesis. LDL receptor-deficient (LDLr−/−) mice with heterozygous hematopoietic GRK2 deficiency, generated by bone marrow transplantation (n=15), displayed a dramatic attenuation of plaque development, with 79% reduction in necrotic core and increased macrophage content. Circulating monocytes decreased and granulocytes increased in GRK2+/− chimeras, which could be attributed to diminished granulocyte colony-forming units in bone marrow. Collectively, these data pointed to myeloid cells as major mediators of the impaired atherogenic response in GRK2+/− chimeras. LDLr−/− mice with macrophage/granulocyte-specific GRK2 deficiency (LysM-Cre GRK2flox/flox; n=8) failed to mimic the aforementioned phenotype, acquitting these cells as major responsible subsets for GRK2 deficiency-associated atheroprotection. To conclude, even partial hematopoietic GRK2 deficiency prevents atherosclerotic lesion progression beyond the fatty streak stage, identifying hematopoietic GRK2 as a potential target for intervention in atherosclerosis.—Otten, J. J. T., de Jager, S. C. A., Kavelaars, A., Seijkens, T., Bot, I., Wijnands, E., Beckers, L., Westra, M. M., Bot, M., Busch, M., Bermudez, B., van Berkel, T. J. C., Heijnen, C. J., Biessen, E. A. L. Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice. PMID:23047899