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Sample records for 1alpha inhibits prostaglandin

  1. Interleukin 1. alpha. inhibits prostaglandin E sub 2 release to suppress pulsatile release of luteinizing hormone but not follicle-stimulating hormone

    SciTech Connect

    Rettori, V.; McCann, S.M. ); Gimeno, M.F. ); Karara, A. ); Gonzalez, M.C. )

    1991-04-01

    Interleukin 1{alpha} (IL-1{alpha}), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, and somatotropin release and inhibits thyrotropin release by hypothalamic action. The authors injected recombinant human IL-1{alpha} into the third cerebral ventricle, to study its effect on the pulsatile release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection of 0.25 pmol of IL-1{alpha} caused an almost immediate reduction of plasma LH concentration. To determine the mechanism of the suppression of LH release, mediobasal hypothalamic fragments were incubated in vitro with IL-1{alpha} (10 pM) and the release of LH-releasing hormone (LHRH) and prostaglandin E{sub 2} into the medium was measured by RIA in the presence or absence of nonrepinephrine. 1{alpha} reduced basal LHRH release and blocked LHRH release induced by nonrepinephrine. In conclusion, IL-1{alpha} suppresses LH but not FSH release by an almost complete cessation of pulsatile release of LH in the castrated rat. The mechanism of this effect appears to be by inhibition of prostaglandin E{sub 2}-mediated release of LHRH.

  2. Sulforaphane Inhibits Prostaglandin E2 Synthesis by Suppressing Microsomal Prostaglandin E Synthase 1

    PubMed Central

    Zhou, Jiping; Joplin, Denise G.; Cross, Janet V.; Templeton, Dennis J.

    2012-01-01

    Sulforaphane (SFN) is a dietary cancer preventive with incompletely characterized mechanism(s) of cancer prevention. Since prostaglandin E2 (PGE2) promotes cancer progression, we hypothesized that SFN may block PGE2 synthesis in cancer cells. We found that SFN indeed blocked PGE2 production in human A549 cancer cells not by inhibiting COX-2, but rather by suppressing the expression of microsomal prostaglandin E synthase (mPGES-1), the enzyme that directly synthesizes PGE2. We identified the Hypoxia Inducible Factor 1 alpha (HIF-1α) as the target of SFN-mediated mPGES-1 suppression. SFN suppressed HIF-1α protein expression and the presence of HIF-1α at the mPGES-1 promoter, resulting in reduced transcription of mPGES-1. Finally, SFN also reduced expression of mPGES-1 and PGE2 production in A549 xenograft tumors in mice. Together, these results point to the HIF-1α, mPGES-1 and PGE2 axis as a potential mediator of the anti-cancer effects of SFN, and illustrate the potential of SFN for therapeutic control of cancer and inflammation. Harmful side effects in patients taking agents that target the more upstream COX-2 enzyme render the downstream target mPGES-1 a significant target for anti-inflammatory therapy. Thus, SFN could prove to be an important therapeutic approach to both cancer and inflammation. PMID:23166763

  3. Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis

    PubMed Central

    Kristensen, David M.; Skalkam, Maria L.; Audouze, Karine; Lesné, Laurianne; Desdoits-Lethimonier, Christele; Frederiksen, Hanne; Brunak, Søren; Skakkebæk, Niels E.; Jégou, Bernard; Hansen, Jacob B.; Junker, Steffen; Leffers, Henrik

    2011-01-01

    Background Prostaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine-disrupting compounds (EDCs) share a high degree of structural similarity with mild analgesics. Objectives and Methods Using cell-based transfection and transduction experiments, mass spectrometry, and organotypic assays together with molecular modeling, we investigated whether inhibition of the PG pathway by known EDCs could be a novel point of endocrine disruption. Results We found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis, and this reduction was correlated with a reduced testosterone production. The inhibition of PG synthesis occurred without involvement of canonical PG receptors or the peroxisome proliferator–activated receptors (PPARs), which have previously been described as targets of EDCs. Instead, our results suggest that the compounds may bind directly into the active site of the cyclooxygenase (COX) enzymes, thereby obstructing the conversion of arachidonic acid to PG precursors without interfering with the expression of the COX enzymes. A common feature of the PG inhibitory EDCs is the presence of aromatic groups that may stabilize binding in the hydrophobic active site of the COX enzymes. Conclusion Our findings suggest a hitherto unknown mode of action by EDCs through inhibition of the PG pathway and suggest new avenues to investigate effects of EDCs on reproductive and immunological disorders that have become increasingly common in recent decades. PMID:21081300

  4. USP14 inhibits ER-associated degradation via interaction with IRE1{alpha}

    SciTech Connect

    Nagai, Atsushi; Kadowaki, Hisae; Maruyama, Takeshi; Takeda, Kohsuke; Nishitoh, Hideki Ichijo, Hidenori

    2009-02-20

    Accumulation of unfolded proteins within the endoplasmic reticulum (ER) lumen induces ER stress. Eukaryotic cells possess the ER quality control systems, the unfolded protein response (UPR), to adapt to ER stress. IRE1{alpha} is one of the ER stress receptors and mediates the UPR. Here, we identified ubiquitin specific protease (USP) 14 as a binding partner of IRE1{alpha}. USP14 interacted with the cytoplasmic region of IRE1{alpha}, and the endogenous interaction between USP14 and IRE1{alpha} was inhibited by ER stress. Overexpression of USP14 inhibited the ER-associated degradation (ERAD) pathway, and USP14 depletion by small interfering RNA effectively activated ERAD. These findings suggest that USP14 is a novel player in the UPR by serving as a physiological inhibitor of ERAD under the non-stressed condition.

  5. Inhibition of GSK3beta by indirubins restores HIF-1alpha accumulation under prolonged periods of hypoxia/anoxia.

    PubMed

    Schnitzer, Steffen E; Schmid, Tobias; Zhou, Jie; Eisenbrand, Gerhard; Brüne, Bernhard

    2005-01-17

    Hypoxia inducible factor 1 is regulated by the appearance of the HIF-1alpha subunit. HIF-1alpha is subjected to proteasomal destruction or enhanced protein translation, which requires the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. We investigated how PI3K/Akt and glycogen synthase kinase 3beta (GSK3beta) affect HIF-1alpha in human RKO cells under prolonged periods of severe hypoxia/anoxia. 16- to 32-h lasting incubations attenuated Akt activity and decreased HIF-1alpha protein. This was reproduced by blocking PI3K with LY294002. GSK3beta inhibition by indirubins circumvented the effect of hypoxia/anoxia or LY294002 on HIF-1alpha. Ruling stability regulation of HIF-1alpha protein and/or enhanced transcription of HIF-1alpha mRNA via GSK3beta inhibition out is suggestive for translational modulation of HIF-1alpha under the influence of GSK3beta. PMID:15642371

  6. Inhibition of HIF-1{alpha} activity by BP-1 ameliorates adjuvant induced arthritis in rats

    SciTech Connect

    Shankar, J.; Thippegowda, P.B.; Kanum, S.A.

    2009-09-18

    Rheumatoid arthritis (RA) is a chronic inflammatory, angiogenic disease. Inflamed synovitis is a hallmark of RA which is hypoxic in nature. Vascular endothelial growth factor (VEGF), one of the key regulators of angiogenesis, is overexpressed in the pathogenesis of RA. VEGF expression is regulated by hypoxia-inducible factor-1{alpha} (HIF-1{alpha}), a master regulator of homeostasis which plays a pivotal role in hypoxia-induced angiogenesis. In this study we show that synthetic benzophenone analogue, 2-benzoyl-phenoxy acetamide (BP-1) can act as a novel anti-arthritic agent in an experimental adjuvant induced arthritis (AIA) rat model by targeting VEGF and HIF-1{alpha}. BP-1 administered hypoxic endothelial cells and arthritic animals clearly showed down regulation of VEGF expression. Further, BP-1 inhibits nuclear translocation of HIF-1{alpha}, which in turn suppresses transcription of the VEGF gene. These results suggest a further possible clinical application of the BP-1 derivative as an anti-arthritic agent in association with conventional chemotherapeutic agents.

  7. Inhibition of protein synthesis by imexon reduces HIF-1alpha expression in normoxic and hypoxic pancreatic cancer cells.

    PubMed

    Samulitis, Betty K; Landowski, Terry H; Dorr, Robert T

    2009-02-01

    Hypoxia-inducing factor-1 alpha (HIF-1alpha), is a major survival factor for tumor cells growing in a low oxygen environment. The anti-cancer agent imexon binds thiols and causes accumulation of reactive oxygen species (ROS) in pancreatic cancer cells. Unlike many cytotoxic agents, imexon is equi-cytotoxic in human MiaPaCa-2 and Panc-1 cells grown in normoxic (21% O(2)) and hypoxic (1% O(2)) conditions. Western blot analyses of imexon-treated cells demonstrated that imexon reduces HIF-1alpha protein levels in both normoxic and hypoxic conditions in a time- and concentration-dependant fashion. Gemcitabine did not similarly affect HIF-1alpha levels. Imexon did not reduce transcription of new HIF-1alpha mRNA, but did reduce the synthesis of new proteins, including HIF-1alpha, measured by (35)S methionine/cysteine (Met/Cys) incorporation. Concurrently, the half-life of existing HIF-1alpha protein was increased by imexon, in association with a marked inhibition of chymotryptic activity in the 20S proteasome. The inhibition of HIF-1alpha translation was not specific, rather it was part of a general decrease in protein translation caused by imexon. This inhibitory effect on translation did not involve phosphorylation of eukaryotic initiation factor-2alpha (eIF-2alpha) and was not closely correlated to cell growth inhibition by imexon, suggesting that mechanisms other than protein synthesis inhibition contribute to the drug's cytotoxic effects. In summary, imexon blocks the translation of new proteins, including HIF-1alpha, and this effect overcomes an increase in the stability of preformed HIF-1alpha due to proteasome inhibition by imexon. Because net HIF-1alpha levels are reduced by imexon, combination studies with other drugs affected by HIF-1alpha survival signaling are warranted. PMID:18607542

  8. Ketoprofen S(+) enantiomer inhibits prostaglandin production and cell growth in 3T6 fibroblast cultures.

    PubMed

    Sánchez, T; Moreno, J J

    1999-04-01

    The ketoprofen S(+) enantiomer inhibits with great stereoselectivity both prostaglandin H synthase isoenzymes. Thus, the biological effects of ketoprofen on inflammation are due almost entirely to the S(+) isomer. Here, we report that the S(+) enantiomer, at doses that inhibit prostaglandin synthesis, is effective in reducing DNA synthesis and 3T6 fibroblast growth. Our data suggest that prostaglandins are involved in the control of 3T6 fibroblast growth and that the effect of the ketoprofen S(+) enantiomer on 3T6 proliferation is correlated with its effects on prostaglandin H synthase and prostaglandin production. PMID:10323281

  9. 1alpha,25-dihydroxyvitamin D3 rapidly inhibits fibroblast-induced collagen gel contraction.

    PubMed

    Greiling, D; Thieroff-Ekerdt, R

    1996-06-01

    1alpha,25-Dihydroxyvitamin D3 (1,25-D3) inhibits the proliferation of fibroblasts in vitro in monolayer culture. We investigated the effect of 1,25-D3 on normal murine and human fibroblasts cultured in collagen type I gels, which more closely resembles the in vivo situation in the dermis. In this culture system 1,25-D3 had no effect on fibroblast proliferation; however, the fibroblast-induced collagen gel contraction was inhibited in a time- and concentration-dependent manner in the nanomolar concentration range. 25-Hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 were inactive. 1,25-D3 had no effect in fibroblasts lacking a functional vitamin D receptor. Pretreatment of fibroblasts in monolayer culture for 5 min was sufficient to trigger the inhibition of collagen gel contraction. Nifedipine increased collagen gel contraction and counteracted the effect of 1,25-D3. The inhibition of collagen gel contraction by 1,25-D3 is supposed to be mediated by the vitamin D receptor because a functional vitamin D receptor is required, and vitamin D metabolites with low affinity to the vitamin D receptor were inactive. Brief pretreatment of fibroblasts was sufficient to trigger the inhibitory effect of 1,25-D3, suggesting a nongenomic effect. A genomic mode of action could not be ruled out, however, because the inhibition was first measured after 24 h. The antagonism of the calcium channel antagonist nifedipine probably represents the sum of two opposite effects rather than supporting evidence for a nongenomic mode of action of 1,25-D3. In conclusion, 1,25-D3 has a specific and rapidly triggered inhibitory effect on fibroblast-induced collagen gel contraction. PMID:8752663

  10. Glomerular and tubular adaptive responses to acute nephron loss in the rat. Effect of prostaglandin synthesis inhibition.

    PubMed Central

    Pelayo, J C; Shanley, P F

    1990-01-01

    These studies, using in vivo micropuncture techniques in the Munich-Wistar rat, document the magnitude of changes in glomerular and tubular function and structure 24 h after approximately 75% nephron loss (Nx) and compared these results with those obtained in sham-operated rats. The contribution of either nephron hypertrophy or renal prostaglandin to these adjustments in nephron function was also explored. After acute Nx, single nephron GFR (SNGFR) was increased, on average by approximately 30%, due primarily to glomerular hyperperfusion and hypertension. The approximately 45% reduction in preglomerular and the constancy in postglomerular vascular resistances was entirely responsible for these adaptations. Although increases in fluid reabsorption in proximal convoluted tubules correlated closely with increase in SNGFR, the fractional fluid reabsorption between late proximal and early distal tubular segments was depressed. Nephron hypertrophy could not be substantiated based on either measurements of protein content in renal tissue homogenates or morphometric analysis of proximal convoluted tubules. However, acute Nx was associated with increased urinary excretory rates per functional nephron for 6-keto-PGF1 alpha and TXB2. Prostaglandin synthesis inhibition did not affect function in control nephrons, but this maneuver was associated with normalization of glomerular and tubular function in remnant nephrons. The results suggest that enhanced synthesis of cyclooxygenase-dependent products is one of the earliest responses to Nx, and even before hypertrophy the pathophysiologic effects of prostaglandin may be important contributors to the adaptations in remnant nephron function. PMID:1693376

  11. Anuran calling circuits: inhibition of pretrigeminal nucleus by prostaglandin.

    PubMed

    Schmidt, R S

    1993-03-01

    Neural correlates of mating calling and pulmonary respiration were recorded from isolated brain stems of male Northern leopard frogs (Rana p. pipiens) before and after exposure of the brain stems to prostaglandin F2 alpha (PG) or saline. Diffusion of PG (but not saline) from a pipette directly over the pretrigeminal nuclei abolished "calling" temporarily. Similar application of PG nearby had no effect. Exposure of only the anterior 1/2 of the brain stem, containing the pretrigeminal nuclei but not the pulmonary respiration generator, to PG (but not saline) abolished generation of slow waves by the pretrigeminal nucleus portion of the mating calling pattern generator. Exposure of only the posterior 1/2 of the brain stem, containing the pulmonary respiration generator but not the pretrigeminal nuclei, to PG had no effect on the correlates of pulmonary respiration. These results are consistent with the hypothesis that the inhibition of calling by PG is through an effect largely, perhaps exclusively, on the pretrigeminal nuclei. PMID:8440519

  12. Prostaglandin release from isolated rabbit cerebral cortex micro-vessels--comparison of 6-keto PGF1 alpha and PGE2 release from micro-vessels incubated in 100% O2, room air and 95% N2:5% CO2.

    PubMed

    Rodrigues, A M; Gerritsen, M E

    1984-01-01

    Prostaglandin release from microvessels isolated from the rabbit cerebral cortex was determined under three different atmospheric conditions: 100% O2 ("O2") room air, and 95% N2:5% CO2 ("N2-CO2"). Initial studies with homogenates prepared from rabbit cerebral microvessels (RCMV) indicated two pathways of enzymatic PGH2 transformation, namely PGI2 synthase and GSH-dependent PGH-PGE isomerase. We measured the release of the principal products of these pathways, 6-keto PGF1 alpha and PGE2 from freshly prepared RCMV. The release of 6-keto PGF1 alpha exceeded that of PGE2 in all three protocols. RCMV incubated in "N2-CO2" exhibited a reduction in the release of 6-keto PGF1 alpha compared to room air or "O2" incubated RCMV, evident at 30-60 min of incubation. No significant differences in the release of PGE2 were observed among the three incubation protocols. In all three incubation protocols the ratio of 6-keto PGF1 alpha to PGE2 did not differ during the initial 10 minutes of each incubation. After 30 to 60 min of incubation, this ratio did not change from the "O2" or room air treated RCMV, but decreased significantly for the "N2-CO2" treated group. To determine the reversibility of the apparent "N2-CO2" induced decline in 6-keto PGF1 alpha release, microvessels were removed from the nitrogen atmosphere and incubated in room air. Release was measured during the initial 10 min following reintroduction to room air and was compared to room air pretreated controls treated in an identical manner.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6431653

  13. Noscapine inhibits hypoxia-mediated HIF-1alpha expression andangiogenesis in vitro: a novel function for an old drug.

    PubMed

    Newcomb, Elizabeth W; Lukyanov, Yevgeniy; Schnee, Tona; Ali, M Aktar; Lan, Li; Zagzag, David

    2006-05-01

    Overexpression of hypoxia-inducible factor-1 (HIF-1) is a common feature in solid malignancies related to oxygen deficiency. Since increased HIF-1 expression correlates with advanced disease stage, increased angiogenesis and poor prognosis, HIF-1 and its signaling pathway have become targets for cancer chemotherapy. In this study, we identified noscapine to be a novel small molecule inhibitor of the HIF-1 pathway based on its structure-function relation-ships with HIF-1 pathway inhibitors belonging to the benzylisoquinoline class of plant metabolites and/or to microtubule binding agents. We demonstrate that noscapine treatment of human glioma U87MG and T98G cell lines exposed to the hypoxic mimetic agent, CoCl2, inhibits hypoxia-mediated HIF-1alpha expression and transcriptional activity as measured by decreased secretion of VEGF, a HIF-1 target gene. Inhibition of hypoxia-mediated HIF-1alpha expression was due, in part, to its ability to inhibit accumulation of HIF-1alpha in the nucleus and target it for degradation via the proteasome. One mechanism of action of microtubule binding agents is their antiangiogenic activity associated with disruption of endothelial tubule formation. We show that noscapine has similar properties in vitro. Thus, noscapine may possess novel antiangiogenic activity associated with two broad mechanisms of action: first, by decreasing HIF-1alpha expression in hypoxic tumor cells, upregulation of target genes, such as VEGF, would be decreased concomitant with its associated angiogenic activity; second, by inhibiting endothelial cells from forming blood vessels in response to VEGF stimulation, it may limit the process of neo-vascularization, correlating with antitumor activity in vivo. For more than 75 years, noscapine has traditionally been used as an oral cough suppressant with no known toxic side effects in man. Thus, the studies reported here have found a novel function for an old drug. Given its low toxicity profile, its demonstrated

  14. Inhibition of prostaglandin synthesis after metabolism of menadione by cultured porcine endothelial cells.

    PubMed Central

    Barchowsky, A; Tabrizi, K; Kent, R S; Whorton, A R

    1989-01-01

    We have examined the effects of menadione on porcine aortic endothelial cell prostaglandin synthesis. Addition of 1-20 microM menadione caused a dose- and time-dependent inhibition of stimulated prostaglandin synthesis with an IC50 of 5 microM at 15 min. Concentrations greater than 100 microM menadione were necessary to increase 51Cr release from prelabeled cells. Recovery of enzyme inactivated by menadione required a 6-h incubation in 1% serum. In a microsomal preparation, menadione was shown to have no direct effect on conversion of arachidonic acid to prostaglandins. In intact cells menadione caused only a 40% inhibition of the conversion of PGH2 to prostacyclin. Enzymes involved in the incorporation and the release of arachidonic acid were not affected by menadione (20 microM, 15 min). Menadione undergoes oxidation/reduction reactions in intact cells leading to partial reduction of oxygen-forming, reactive oxygen species. In our cells menadione was found to increase KCN-resistant oxygen consumption. Further, an increased accumulation of H2O2 was observed with a time course consistent with menadione-induced inhibition of prostaglandin synthesis. We conclude that menadione at sublethal doses caused inhibition of prostaglandin synthesis. The mechanism involves inactivation of PGH2 synthase by a reactive species resulting from metabolism of menadione by endothelial cells. PMID:2495300

  15. Inhibition of 15-hydroxy prostaglandin dehydrogenase and increase of prostaglandin E2: effect of sofalcone on rat gastric mucosa.

    PubMed

    Muramatsu, M; Tanaka, M; Murakami, S; Aihara, H

    1987-07-20

    The effect of sofalcone, an anti-ulcer agent, on gastric mucosal prostaglandin (PG) metabolism was studied. Gastric mucosal PGE2 was determined in rats in which PGE2 synthesis was inhibited by preadministration of indomethacin. Oral administration of sofalcone at doses of 200 and 400 mg/kg significantly inhibited the PG metabolizing enzyme, 15-hydroxy-PG-dehydrogenase (15-OH-PG-DH) activity and increased PGE2 contents in the rat gastric mucosa. The inhibition of 15-OH-PG-DH activity was accompanied by an increase of PGE2 contents up to 6 hours after the administration of sofalcone. These changes, however, were not observed 12 hours after its administration. Intraperitoneally administered sofalcone also inhibited 15-OH-PG-DH activity and increased PGE2 content. The inhibition of 15-OH-PG-DH activity by sofalcone was noncompetitive and uncompetitive against substrates NAD and PGE1, respectively. These results suggest that the increase of the gastric PGE2 level is mainly due to the inhibition of 15-OH-PG-DH activity, and this increase in PGE2 may be involved in the anti-ulcer effect of sofalcone. PMID:3474485

  16. Inhibition of the Prostaglandin Degrading Enzyme 15-PGDH Potentiates Tissue Regeneration *

    PubMed Central

    Zhang, Yongyou; Desai, Amar; Yang, Sung Yeun; Bae, Ki Beom; Antczak, Monika I.; Fink, Stephen P.; Tiwari, Shruti; Willis, Joseph E.; Williams, Noelle S.; Dawson, Dawn M.; Wald, David; Chen, Wei-Dong; Wang, Zhenghe; Kasturi, Lakshmi; Larusch, Gretchen A.; He, Lucy; Cominelli, Fabio; Di Martino, Luca; Djuric, Zora; Milne, Ginger L.; Chance, Mark; Sanabria, Juan; Dealwis, Chris; Mikkola, Debra; Naidoo, Jacinth; Wei, Shuguang; Tai, Hsin-Hsiung; Gerson, Stanton L.; Ready, Joseph M.; Posner, Bruce; Willson, James K. V.; Markowitz, Sanford D.

    2015-01-01

    Tissue regeneration is a medical challenge faced in injury from disease and during medical treatments such as bone marrow transplantation. Prostaglandin PGE2, which supports expansion of several types of tissue stem cells, is a candidate therapeutic target for promoting tissue regeneration in vivo. Here we show that inhibition of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a prostaglandin-degrading enzyme, potentiates tissue regeneration in multiple organs in mice. In a chemical screen, we identify a small-molecule inhibitor of 15-PGDH (SW033291) that increases prostaglandin PGE2 levels in bone marrow and other tissues. SW033291 accelerates hematopoietic recovery in mice receiving a bone marrow transplant. SW033291 also promotes tissue regeneration in mouse models of colon and liver injury. Tissues from 15-PGDH knockout mice demonstrate similar increased regenerative capacity. These findings raise the possibility that inhibiting 15-PGDH could be a useful therapeutic strategy in several distinct clinical settings. PMID:26068857

  17. Inhibition of the Prostaglandin Transporter PGT Lowers Blood Pressure in Hypertensive Rats and Mice

    PubMed Central

    Chi, Yuling; Jasmin, Jean-Francois; Seki, Yoshinori; Lisanti, Michael P.; Charron, Maureen J.; Lefer, David J.; Schuster, Victor L.

    2015-01-01

    Inhibiting the synthesis of endogenous prostaglandins with nonsteroidal anti-inflammatory drugs exacerbates arterial hypertension. We hypothesized that the converse, i.e., raising the level of endogenous prostaglandins, might have anti-hypertensive effects. To accomplish this, we focused on inhibiting the prostaglandin transporter PGT (SLCO2A1), which is the obligatory first step in the inactivation of several common PGs. We first examined the role of PGT in controlling arterial blood pressure blood pressure using anesthetized rats. The high-affinity PGT inhibitor T26A sensitized the ability of exogenous PGE2 to lower blood pressure, confirming both inhibition of PGT by T26A and the vasodepressor action of PGE2 T26A administered alone to anesthetized rats dose-dependently lowered blood pressure, and did so to a greater degree in spontaneously hypertensive rats than in Wistar-Kyoto control rats. In mice, T26A added chronically to the drinking water increased the urinary excretion and plasma concentration of PGE2 over several days, confirming that T26A is orally active in antagonizing PGT. T26A given orally to hypertensive mice normalized blood pressure. T26A increased urinary sodium excretion in mice and, when added to the medium bathing isolated mouse aortas, T26A increased the net release of PGE2 induced by arachidonic acid, inhibited serotonin-induced vasoconstriction, and potentiated vasodilation induced by exogenous PGE2. We conclude that pharmacologically inhibiting PGT-mediated prostaglandin metabolism lowers blood pressure, probably by prostaglandin-induced natriuresis and vasodilation. PGT is a novel therapeutic target for treating hypertension. PMID:26121580

  18. Nonstructural protein 1{alpha} subunit-based inhibition of NF-{kappa}B activation and suppression of interferon-{beta} production by porcine reproductive and respiratory syndrome virus

    SciTech Connect

    Song Cheng; Krell, Peter; Yoo, Dongwan

    2010-11-25

    Induction of type I interferon (IFN-{alpha}/{beta}) is an early antiviral response of the host, and porcine reproductive and respiratory syndrome virus (PRRSV) has been reported to downregulate the IFN response during infection in cells and pigs. We report that the PRRSV nonstructural protein 1{alpha} (Nsp1{alpha}) subunit of Nsp1 is a nuclear-cytoplasmic protein distributed to the nucleus and contains a strong suppressive activity for IFN-{beta} production that is mediated through the retinoic acid-inducible gene I (RIG-I) signaling pathway. Nsp1{alpha} suppressed the activation of nuclear factor (NF)-{kappa}B when stimulated with dsRNA or tumor necrosis factor (TNF)-{alpha}, and NF-{kappa}B suppression was RIG-I-dependent. The suppression of NF-{kappa}B activation was associated with the poor production of IFN-{beta} during PRRSV infection. The C-terminal 14 amino acids of the Nsp1{alpha} subunit were critical in maintaining immunosuppressive activity of Nsp1{alpha} for both IFN-{beta} and NF-{kappa}B, suggesting that the newly identified zinc finger configuration comprising of Met180 may be crucial for inhibitory activities. Nsp1{alpha} inhibited I{kappa}B phosphorylation and as a consequence NF-{kappa}B translocation to the nucleus was blocked, leading to the inhibition of NF-{kappa}B stimulated gene expression. Our results suggest that PRRSV Nsp1{alpha} is a multifunctional nuclear protein participating in the modulation of the host IFN system.

  19. Stimulus specificity of prostaglandin inhibition of rabbit polymorphonuclear leukocyte lysosomal enzyme release and superoxide anion production.

    PubMed Central

    Fantone, J. C.; Marasco, W. A.; Elgas, L. J.; Ward, P. A.

    1984-01-01

    Prostaglandins (PGs) of the E series and PGI2 have been shown to inhibit acute inflammatory reactions in vivo and polymorphonuclear leukocyte (PMN), chemotaxis, lysosomal enzyme release, and superoxide anion (O-2) production in vitro. This inhibition of neutrophil stimulation by PGEs and PGI2 has been correlated with their ability to increase intracellular cyclic adenosine monophosphate (cAMP) levels. However, the mechanism(s) by which PGEs and PGI2 alter the complex biochemical and biophysical events associated with stimulus-response coupling in the neutrophil are not clear. It is reported here that both PGEs and PGI2 in micromolar concentrations inhibit formyl-methionyl-leucyl-phenylalanine (FMLP)- and zymosan-induced lysosomal enzyme secretion and superoxide anion production in a dose-dependent manner. No preincubation time of PMNs with the prostaglandins is required for inhibition. Addition of PGEs 10 seconds or later after FMLP stimulation does not alter the biologic response of the neutrophils to the stimulus, suggesting that the prostaglandin inhibition effects early events associated with stimulus-response coupling in the neutrophil. Prostaglandin inhibition of lysosomal enzyme release by the calcium ionophore A23187 was overcome by increasing the extracellular ionophore and/or calcium concentration, suggesting that PGs may modulate intracellular free calcium levels in a manner similar to that observed with platelets. Inhibition of phorbol myristate acetate (PMA)-induced neutrophil lysosomal enzyme secretion by PGEs and PGI2 was overcome by increasing concentrations of PMA. However, neither PGEs nor PGI2 altered O-2 production by PMA-treated neutrophils. These data indicate a dissociation between PMA-stimulated O-2 production and lysosomal enzyme release. These findings are consistent with the hypothesis that inhibition of neutrophil stimulation by PGEs and PGI2 is a result of increased intracellular cyclic AMP levels and modulation of calcium

  20. Inhibition of prostaglandin E2 receptor EP3 mitigates thrombin-induced brain injury.

    PubMed

    Han, Xiaoning; Lan, Xi; Li, Qiang; Gao, Yufeng; Zhu, Wei; Cheng, Tian; Maruyama, Takayuki; Wang, Jian

    2016-06-01

    Prostaglandin E2 EP3 receptor is the only prostaglandin E2 receptor that couples to multiple G-proteins, but its role in thrombin-induced brain injury is unclear. In the present study, we exposed mouse hippocampal slice cultures to thrombin in vitro and injected mice with intrastriatal thrombin in vivo to investigate the role of EP3 receptor in thrombin-induced brain injury and explore its underlying cellular and molecular mechanisms. In vitro, EP3 receptor inhibition reduced thrombin-induced hippocampal CA1 cell death. In vivo, EP3 receptor was expressed in astrocytes and microglia in the perilesional region. EP3 receptor inhibition reduced lesion volume, neurologic deficit, cell death, matrix metalloproteinase-9 activity, neutrophil infiltration, and the number of CD68(+) microglia, but increased the number of Ym-1(+) M2 microglia. RhoA-Rho kinase levels were increased after thrombin injection and were decreased by EP3 receptor inhibition. In mice that received an intrastriatal injection of autologous arterial blood, inhibition of thrombin activity with hirudin decreased RhoA expression compared with that in vehicle-treated mice. However, EP3 receptor activation reversed this effect of hirudin. These findings show that prostaglandin E2 EP3 receptor contributes to thrombin-induced brain damage via Rho-Rho kinase-mediated cytotoxicity and proinflammatory responses. PMID:26661165

  1. [Hydroxysafflor yellow A up-regulates HIF-1alpha via inhibition of VHL and p53 in Eahy 926 cell line exposed to hypoxia].

    PubMed

    Lian, Ze-Qin; Zhao, Da-Long; Zhu, Hai-Bo

    2008-05-01

    In present study, we investigated the mechanism of regulating HIF-1alpha expression by hydroxysafflor yellow A (HSYA) in Eahy 926 cell line under 1% O2 hypoxia. Eahy 926 cells were incubated with HSYA (100, 10 and 1 micromol x L(-1)) under hypoxia for the indicated time after treatment. Cell proliferation rate was detected using MTT assays. VHL and p53 location and protein expression were analyzed by immunocytochemical stain. HIF-1alpha, VHL and p53 mRNA expression were detected by RT-PCR. Protein expression of HIF-1alpha, VHL and p53 were assayed by Western blotting method. HSYA at 100 micromol x L(-1) increased Eahy 926 cells proliferation rate under hypoxia. HIF-1alpha mRNA and protein expression were up-regulated in the presence of HSYA. VHL, p53 mRNA and protein expression decreased significantly after 8 hours of treatment under hypoxia. HSYA protected Eahy 926 cells from hypoxia, and up-regulated HIF-1alpha expression partially via its inhibition of VHL and p53 expression. PMID:18717335

  2. [Inhibition of prostaglandins synthesis in the inflamed site results in opioid-mediated hypoalgesia in rats].

    PubMed

    Huang, Jian; Wu, Jian; Yang, Huai-Zu; Hong, Yanguo

    2016-06-25

    This study was designed to investigate the contribution of prostaglandins to the maintenance of inflammatory pain. Inflammation was induced by intraplantar (i.pl.) injection of carrageenan in right hindpaw in rats. Indomethacin (non-selective COX inhibitor) was administered i.pl. 1 h after the carrageenan injection, and paw withdrawal latency (PWL) responding to noxious heat was measured. β-endorphin (β-END) and μ-opioid receptor (MOR) expressed in the inflamed site were examined by using immunocytochemistry, ELISA and RT-PCR techniques. The results showed that indomethacin dose-dependently increased PWL to the levels that were above the baseline on the day 2 and 3, referred to as hypoalgesia. The hypoalgesia was abolished by a local injection of the non-selective opioid receptor inhibitor naloxone methiodide. The number of β-END-positive cells, the content of β-END and the expression of MOR mRNA in the inflammatory site of inflammation model rats were all significantly increased by indomethacin. These results reveal a novel mechanism of prostaglandins for the inhibition of inflammation-induced endogenous opioid activity. This study provides further evidence that inhibition of prostaglandins in inflamed site could be a promising therapy for inflammatory pain. PMID:27350196

  3. Inhibition of microsomal prostaglandin E synthase-1 as targeted therapy in cancer treatment.

    PubMed

    Larsson, Karin; Jakobsson, Per-Johan

    2015-07-01

    The bioactive lipid prostaglandin E2 (PGE2) is involved in several steps of carcinogenesis in some of the most common cancers, e.g. colon cancer, lung cancer, prostate cancer and breast cancer. Non-steroidal anti-inflammatory drugs (NSAIDs) that target cyclooxygenase (COX) activity, the first step of the PGE2 biosynthesis, has been found to reduce the incidence of colon cancer. Due to severe adverse effects on the gastrointestinal tract and the cardiovascular system, their use as chemopreventing agent has been hampered. Genetic deletion of microsomal prostaglandin E synthase-1 (mPGES-1), the enzyme responsible for the second step of the PGE2 biosynthesis, has resulted in reduced tumor progression in mouse models of colon cancer. Inhibition of mPGES-1 would potentially be beneficial to a great number of patients without the side effects associated with long-term treatment with traditional NSAIDs. PMID:26100239

  4. Influence of prostaglandins and adrenoceptor agonists on contractile activity in the human cervix at term.

    PubMed

    Bryman, I; Norström, A; Lindblom, B

    1986-04-01

    The influence of prostaglandins as well as adrenoceptor agonists and antagonists on contractile activity of isolated cervical smooth muscle from term pregnant women was studied. Prostaglandin E2 had an inhibitory effect at extremely low concentrations. Inhibition also was induced by prostaglandin F2 alpha, prostaglandin I2, and 6-keto-prostaglandin F1 alpha, but at considerably higher concentrations. Contractions evoked by noradrenaline or phenylephrine were blocked by the alpha-adrenoceptor antagonist phenoxybenzamine. The beta-adrenoceptor agonist terbutaline acted as an inhibitor, whereas isoprenaline in most cases stimulated contractile activity. The inhibitory action of prostaglandins and especially the high sensitivity to prostaglandin E2 point to a physiologic role of these compounds for cervical dilatation and retraction. A predominance of alpha-adrenoceptors might be of importance for the maintenance of cervical competence during pregnancy. PMID:2870450

  5. The cyclopentenone prostaglandin 15d-PGJ2 inhibits the NLRP1 and NLRP3 inflammasomes

    PubMed Central

    Maier, Nolan K.; Leppla, Stephen H.; Moayeri, Mahtab

    2015-01-01

    Inflammasomes are cytosolic protein complexes that respond to diverse danger signals by activating caspase-1. The sensor components of the inflammasome, often proteins of the nucleotide-binding oligomerization domain-like receptor (NLR) family, detect stress, danger stimuli, and pathogen-associated molecular patterns. We report that the eicosanoid 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and related cyclopentenone prostaglandins inhibit caspase-1 activation by the NLRP1 and NLRP3 inflammasomes. This inhibition was independent of 15d-PGJ2’s well characterized role as a peroxisome proliferator receptor-γ agonist, its activation of NRF2, or its anti-inflammatory function as an inhibitor of NF-κB. Instead, 15d-PGJ2 prevents the autoproteolytic activation of caspase-1 and the maturation of IL-1β through induction of a cellular state inhibitory to caspase-1 proteolytic function. The eicosanoid does not directly modify or inactivate the caspase-1 enzyme. Rather, inhibition is dependent on de novo protein synthesis. In a mouse peritonitis model of gout, using monosodium urate crystals to activate NLRP3,15d-PGJ2 caused a significant inhibition of cell recruitment and associated IL-1β release. Furthermore, in a murine anthrax infection model, 15d-PGJ2 reversed anthrax lethal toxin-mediated NLRP1-dependent resistance. The findings reported in this work suggest a novel mechanism for the anti-inflammatory properties of the cyclopentenone prostaglandins through inhibition of caspase-1 and the inflammasome. PMID:25681332

  6. Angiotensin II induced release of prostaglandins from rat uterus.

    PubMed

    Campos, G A; Guerra, F A; Israel, E J

    1983-08-01

    The effect of Angiotensin II (A-II) on 6-keto-prostaglandin F1 (6-keto-PGF1 alpha) and prostaglandin F (PGF) production by the rat uterus was studied using a novel superfusion technique. The method of superfusion used allows prostaglandin synthesis in the myometrium and endometrium to be measured independently while their anatomical relationship is undisturbed. Prostaglandins were measured by radioimmunoassay. In uterine horns from castrated, estrogen treated rats, A-II (10(-6)M) stimulated the production rate of 6-keto-PGF1 alpha in the myometrium nd PGF in the endometrium. Sterile horns and pregnant horns coexisting in the same animals showed different responses when superfused with culture medium containing A-II (10(-6)M). In the sterile horns A-II failed to stimulate prostaglandin synthesis whereas in the pregnant horns there was a significant increase in the production rate of both 6-keto-PGF1 alpha and PGF in the decidua (endometrium) and of 6-keto-PGF1 alpha in the myometrium. Our results suggests that the effect of A-II on prostaglandin synthesis by the rat uterus appears to be dependent of the hormonal milieu of the experimental animal. Estrogen stimulated A-II induced PG synthesis. Progesterone inhibited the synthesis of PGs caused by A-II in non-decidualized uterus but stimulated the release of PG in the decidualized uterus. The apparent differential effect of A-II in stimulating prostaglandin synthesis in the whole uterus indicates that there are different pathways for prostaglandin production in both the endometrium and myometrium. PMID:6689628

  7. Proanthocyanidins inhibit in vitro and in vivo growth of human non-small cell lung cancer cells by inhibiting the prostaglandin E(2) and prostaglandin E(2) receptors.

    PubMed

    Sharma, Som D; Meeran, Syed M; Katiyar, Santosh K

    2010-03-01

    Overexpression of cyclooxygenase-2 (COX-2) and prostaglandins (PG) is linked to a wide variety of human cancers. Here, we assessed whether the chemotherapeutic effect of grape seed proanthocyanidins (GSP) on non-small cell lung cancer (NSCLC) cells is mediated through the inhibition of COX-2 and PGE(2)/PGE(2) receptor expression. The effects of GSPs on human NSCLC cell lines in terms of proliferation, apoptosis, and expression of COX-2, PGE(2), and PGE(2) receptors were determined using Western blotting, fluorescence-activated cell sorting analysis, and reverse transcription-PCR. In vitro treatment of NSCLC cells (A549, H1299, H460, H226, and H157) with GSPs resulted in significant growth inhibition and induction of apoptosis, which were associated with the inhibitory effects of GSPs on the overexpression of COX-2, PGE(2), and PGE(2) receptors (EP1 and EP4) in these cells. Treatment of cells with indomethacin, a pan-COX inhibitor, or transient transfection of cells with COX-2 small interfering RNA, also inhibited cell growth and induced cell death. The effects of a GSP-supplemented AIN76A control diet fed to nude mice bearing tumor xenografts on the expression of COX-2, PGE(2), and PGE(2) receptors in the xenografts were also evaluated. The growth-inhibitory effect of dietary GSPs (0.5%, w/w) on the NSCLC xenograft tumors was associated with the inhibition of COX-2, PGE(2), and PGE(2) receptors (EP1, EP3, and EP4) in tumors. This preclinical study provides evidence that the chemotherapeutic effect of GSPs on lung cancer cells in vitro and in vivo is mediated, at least in part, through the inhibition of COX-2 expression and subsequently the inhibition of PGE(2) and PGE(2) receptors. PMID:20145019

  8. Inhibition of protein translation as a novel mechanism for prostaglandin E2 regulation of cell functions

    PubMed Central

    Okunishi, Katsuhide; DeGraaf, Angela J.; Zasłona, Zbigniew; Peters-Golden, Marc

    2014-01-01

    Prostaglandin E2 (PGE2) regulates numerous biological processes by modulating transcriptional activation, epigenetic control, proteolysis, and secretion of various proteins. Scar formation depends on fibroblast elaboration of matrix proteins such as collagen, and this process is strongly suppressed by PGE2 through activation of cAMP-dependent protein kinase A (PKA). However, the actual mechanism by which PGE2-PKA signaling inhibits collagen expression in fibroblasts has never been delineated, and that was the objective of this study. PGE2 unexpectedly induced a rapid reduction in procollagen I protein expression in adult lung fibroblasts, with a half-maximum effect at 1.5 h. This effect reflected its inhibition of translation rather than transcription. Global protein synthesis was also inhibited by PGE2. This action was mediated by PKA and involved both activation of ribosomal protein (rpS6) and suppression of mammalian target of rapamycin (mTOR). Similar effects of PGE2 were demonstrated in mouse peritoneal macrophages (PMs). These findings identify inhibition of translation as a new mechanism by which PGE2 regulates cellular function and a novel example of translational inhibition mediated by opposing actions on two distinct translational control pathways. Translational inhibition would be expected to contribute to dynamic alterations in cell function that accompany the changing PGE2 levels observed in disease states and with various pharmacotherapies.—Okunishi K., DeGraaf, A. J., Zasłona, Z., Peters-Golden, M. Inhibition of protein translation as a novel mechanism for prostaglandin E2 regulation of cell functions. PMID:24072780

  9. Interleukin-4 inhibits prostaglandin E2 production by freshly prepared adherent rheumatoid synovial cells via inhibition of biosynthesis and gene expression of cyclo-oxygenase II but not of cyclo-oxygenase I.

    PubMed Central

    Sugiyama, E; Taki, H; Kuroda, A; Mino, T; Yamashita, N; Kobayashi, M

    1996-01-01

    OBJECTIVE: To characterise the effect of interleukin-4 (IL-4) on the biosynthesis of cyclo-oxygenases I (COX I) and II (COX II), the rate limiting enzymes of the synthesis of prostaglandin E2 (PGE2), in freshly prepared rheumatoid synovial cells. METHODS: Adherent synovial cells were obtained from rheumatoid synovium by collagenase digestion. The concentrations of PGE2 in culture supernatants were determined by enzyme linked immunosorbent assay. The protein and mRNA concentrations of COX I and COX II were determined by Western blotting and reverse transcription polymerase chain reaction, respectively. RESULTS: Freshly prepared synovial cells produced large amounts of PGE2. They also showed increased gene expression of COX I and COX II, and synthesised these proteins. IL-4 had suppressive effects on the production of PGE2 by untreated or lipopolysaccharide (LPS) stimulated synovial cells. In addition, IL-4 inhibited the biosynthesis of COX II at the mRNA level. In contrast, it did not modify the protein concentration of COX I. In tests of cell specificity, IL-4 did not reduce the mRNA concentration of COX II in interleukin-1 alpha (IL-1 alpha) stimulated cultured synovial fibroblasts at passages 3-6, but it reduced considerably the mRNA concentrations of COX II in an LPS or IL-1 alpha stimulated U937 monocyte/macrophage cell line. CONCLUSIONS: These results suggest that IL-4 might inhibit overproduction of PGE2 in rheumatoid synovia via selective inhibition of the biosynthesis of COX II, and that this inhibition might be specific to macrophage-like synovial cells. Images PMID:8694577

  10. Prostaglandin D2 inhibits wound-induced hair follicle neogenesis through the receptor, Gpr44.

    PubMed

    Nelson, Amanda M; Loy, Dorothy E; Lawson, John A; Katseff, Adiya S; Fitzgerald, Garret A; Garza, Luis A

    2013-04-01

    Prostaglandins (PGs) are key inflammatory mediators involved in wound healing and regulating hair growth; however, their role in skin regeneration after injury is unknown. Using wound-induced hair follicle neogenesis (WIHN) as a marker of skin regeneration, we hypothesized that PGD2 decreases follicle neogenesis. PGE2 and PGD2 were elevated early and late, respectively, during wound healing. The levels of WIHN, lipocalin-type prostaglandin D2 synthase (Ptgds), and its product PGD2 each varied significantly among background strains of mice after wounding, and all correlated such that the highest Ptgds and PGD2 levels were associated with the lowest amount of regeneration. In addition, an alternatively spliced transcript variant of Ptgds missing exon 3 correlated with high regeneration in mice. Exogenous application of PGD2 decreased WIHN in wild-type mice, and PGD2 receptor Gpr44-null mice showed increased WIHN compared with strain-matched control mice. Furthermore, Gpr44-null mice were resistant to PGD2-induced inhibition of follicle neogenesis. In all, these findings demonstrate that PGD2 inhibits hair follicle regeneration through the Gpr44 receptor and imply that inhibition of PGD2 production or Gpr44 signaling will promote skin regeneration. PMID:23190891

  11. Prostaglandin D2 inhibits wound-induced hair follicle neogenesis through the receptor, Gpr44

    PubMed Central

    Nelson, Amanda M.; Loy, Dorothy E.; Lawson, John A.; Katseff, Adiya S.; FitzGerald, Garret A.; Garza, Luis A.

    2012-01-01

    Prostaglandins (PGs) are key inflammatory mediators involved in wound healing and regulating hair growth; however, their role in skin regeneration after injury is unknown. Using wound-induced hair follicle neogenesis (WIHN) as a marker of skin regeneration, we hypothesized that PGD2 decreases follicle neogenesis. PGE2 and PGD2 were elevated early and late respectively during wound healing. The levels of WIHN, lipocalin-type prostaglandin D2 synthase (Ptgds) and its product PGD2 each varied significantly among background strains of mice after wounding and all correlated such that the highest Ptgds and PGD2 levels were associated with the lowest amount of regeneration. Additionally, an alternatively spliced transcript variant of Ptgds missing exon 3 correlated with high regeneration in mice. Exogenous application of PGD2 decreased WIHN in wild type mice and PGD2 receptor Gpr44 null mice showed increased WIHN compared to strain-matched control mice. Furthermore, Gpr44 null mice were resistant to PGD2-induced inhibition of follicle neogenesis. In all, these findings demonstrate that PGD2 inhibits hair follicle regeneration through the Gpr44 receptor and imply that inhibition of PGD2 production or Gpr44 signaling will promote skin regeneration. PMID:23190891

  12. Aspirin inhibits interleukin 1-induced prostaglandin H synthase expression in cultured endothelial cells

    SciTech Connect

    Wu, K.K.; Sanduja, R.; Tsai, A.L.; Ferhanoglu, B.; Loose-Mitchell, D.S. )

    1991-03-15

    Prostaglandin H (PGH) synthase is a key enzyme in the biosynthesis of prostaglandins, thromboxane, and prostacyclin. In cultured human umbilical vein endothelial cells, interleukin 1 (IL-1) is known to induce the synthesis of this enzyme, thereby raising the level of PGH synthase protein severalfold over the basal level. Pretreatment with aspirin at low concentrations inhibited more than 60% of the enzyme mass and also the cyclooxygenase activity in IL-1-induced cells with only minimal effects on the basal level of the synthase enzyme in cells without IL-1. Sodium salicylate exhibited a similar inhibitory action whereas indomethacin had no apparent effect. Similarly low levels of aspirin inhibited the increased L-({sup 35}S)methionine incorporation into PGH synthase that was induced by IL0-1 and also suppressed expression of the 2.7-kilobase PGH synthase mRNA. These results suggest that in cultured endothelial cells a potent inhibition of eicosanoid biosynthetic capacity can be effected by aspirin or salicylate at the level of PGH synthase gene expression. The aspirin effect may well be due to degradation of salicylate.

  13. Topical glucocorticoids application induced an augmentation in the expression of IL-1alpha while inhibiting the expression of IL-10 in the epidermis in murine contact hypersensitivity.

    PubMed

    Igawa, K; Yokozeki, H; Miyazaki, Y; Minatohara, K; Satoh, T; Katayama, I; Nishioka, K

    2001-03-01

    The repeated application of glucocorticoids (GC) on the skin augmented the inflammatory response of both allergic and irritant contact dermatitis in our studies. In order to further clarify the mechanism of such an augmentation of contact hypersensitivity (CHS), we investigated the modulatory effects of cytokines in the epidermis after the administration of GC at challenged sites in CHS. Diflucortolone valerate was applied to BALB/c mice on alternate days for a total of nine times. On day 12, they were contact sensitized with dinitrofluorobenzene (DNFB). Next, on day 17, one day after the last application of GC, they were challenged with DNFB on the ear. The whole challenged ear lobes were removed after a hapten challenge and then were analysed by the RT-PCR method or underwent an immunohistochemical analysis. To clarify the modulatory effects of cytokines in vivo, DNFB sensitized mice pre-treated with GC were injected with rIL-10, IL-1 receptor antagonist (ra) and anti-IL-1alpha monoclonal antibody (mAb) and thereafter were challenged with DNFB. A RT-PCR analysis has demonstrated IL-10 mRNA to be detected in the challenged skin of non-GC-pretreated mice but not in that of GC-pre-treated mice after challenge. On the other hand, the expression of IL-1alpha mRNA in the challenged skin of mice pretreated with GC was more strongly detected that that in mice without GC-pretreatment. Furthermore, an immuno-histochemical analysis in the challenge showed the expression of IL-10 in the skin showed the expression of IL-10 in the challenged epidermis of the non-GC-pretreated mice but not in the GC-pretreated mice and IL-1alpha was also strongly expressed in the epidermis of the GC-pretreated mice. A subcutaneous injection of anti-IL-1alpha mAb or IL-1 ra inhibited the augmented CHS reaction in the GC-pretreated mice. A subcutaneous injection of rIL-10 also inhibited the augmentation of the CHS reaction in the GC-pretreated mice; however, no such inhibition was observed in the

  14. Pharmacological inhibition of interleukin-1 activity on T cells by hydrocortisone, cyclosporine, prostaglandins, and cyclic nucleotides.

    PubMed

    Tracey, D E; Hardee, M M; Richard, K A; Paslay, J W

    1988-01-01

    The effects of a panel of hormones and pharmacological agents on the activation of T cells by a combination of interleukin-1 and phytohemagglutinin (IL-1/PHA) was studied. Pharmacological effects on various stages of IL-1/PHA-induced interleukin-2 (IL-2) production by the cloned murine thymoma cell line LBRM-33-1A5.7 were dissected using a multi-step assay procedure. A 4-h lag phase in the kinetics of IL-2 production allowed the operational definition of an early, IL-1-dependent programming stage, followed by an IL-2-production stage of the assay. A cell-washing procedure between these stages was introduced in order to distinguish IL-1 receptor antagonists from functional IL-1/PHA antagonists. Hydrocortisone and cyclosporine were potent inhibitors (active in the nM range) of both stages of IL-2 production, suggesting that neither is an IL-1 receptor antagonist. The cyclic adenosine monophosphate (cAMP)-elevating agents prostaglandin E2, dibutyryl cAMP, and theophylline inhibited IL-2 production during the early, IL-1-dependent programming stage. By contrast, prostaglandin F2 alpha and dibutyryl cyclic guanosine monophosphate did not appreciably inhibit IL-1/PHA activity. These results are discussed in relationship to the effects of these test agents in thymocyte IL-1 assays or mitogenesis assays and the implications toward understanding the mechanisms underlying IL-1/PHA activation of T cells. PMID:3258857

  15. Frondoside A inhibits breast cancer metastasis and antagonizes prostaglandin E receptors EP4 and EP2

    PubMed Central

    Ma, Xinrong; Kundu, Namita; Collin, Peter D; Goloubeva, Olga; Fulton, Amy

    2013-01-01

    Frondoside A, derived from the sea cucumber Cucumaria frondosa has demonstrable anticancer activity in several models, however, the ability of Frondoside A to affect tumor metastasis has not been reported. Using a syngeneic murine model of metastatic breast cancer, we now show that Frondoside A has potent antimetastatic activity. Frondoside A given i.p. to mice bearing mammary gland implanted mammary tumors, inhibits spontaneous tumor metastasis to the lungs. The elevated Cyclooxygenase -2 activity in many malignancies promotes tumor growth and metastasis by producing high levels of PGE2 which acts on the prostaglandin E receptors, chiefly EP4 and EP2. We examined the ability of Frondoside A to modulate the functions of these EP receptors. We now show that Frondoside A antagonizes the prostaglandin E receptors EP2 and EP4. 3H-PGE2 binding to recombinant EP2 or EP4-expressing cells was inhibited by Frondoside A at low μM concentrations. Likewise, EP4 or EP2-linked activation of intracellular cAMP as well as EP4-mediated ERK1/2 activation were also inhibited by Frondoside A. Consistent with the antimetastatic activity observed in vivo, migration of tumor cells in vitro in response to EP4 or EP2 agonists was also inhibited by Frondoside A. These studies identify a new function for an agent with known antitumor activity, and show that the antimetastatic activity may be due in part to a novel mechanism of action. These studies add to the growing body of evidence that Frondoside A may be a promising new agent with potential to treat cancer and may also represent a potential new modality to antagonize EP4. PMID:21761157

  16. Frondoside A inhibits breast cancer metastasis and antagonizes prostaglandin E receptors EP4 and EP2.

    PubMed

    Ma, Xinrong; Kundu, Namita; Collin, Peter D; Goloubeva, Olga; Fulton, Amy M

    2012-04-01

    Frondoside A, derived from the sea cucumber Cucumaria frondosa has demonstrable anticancer activity in several models, however, the ability of Frondoside A to affect tumor metastasis has not been reported. Using a syngeneic murine model of metastatic breast cancer, we now show that Frondoside A has potent antimetastatic activity. Frondoside A given i.p. to mice bearing mammary gland-implanted mammary tumors, inhibits spontaneous tumor metastasis to the lungs. The elevated Cyclooxygenase-2 activity in many malignancies promotes tumor growth and metastasis by producing high levels of PGE(2) which acts on the prostaglandin E receptors, chiefly EP4 and EP2. We examined the ability of Frondoside A to modulate the functions of these EP receptors. We now show that Frondoside A antagonizes the prostaglandin E receptors EP2 and EP4. (3)H-PGE(2) binding to recombinant EP2 or EP4-expressing cells was inhibited by Frondoside A at low μM concentrations. Likewise, EP4 or EP2-linked activation of intracellular cAMP as well as EP4-mediated ERK1/2 activation were also inhibited by Frondoside A. Consistent with the antimetastatic activity observed in vivo, migration of tumor cells in vitro in response to EP4 or EP2 agonists was also inhibited by Frondoside A. These studies identify a new function for an agent with known antitumor activity, and show that the antimetastatic activity may be due in part to a novel mechanism of action. These studies add to the growing body of evidence that Frondoside A may be a promising new agent with potential to treat cancer and may also represent a potential new modality to antagonize EP4. PMID:21761157

  17. Effects of prostaglandin inhibition on intrarenal hemodynamics in acutely saline-loaded rats.

    PubMed

    Düsing, R; Melder, B; Kramer, H J

    1977-09-01

    We studied the effect of inhibition of the prostaglandin (PG)-synthesizing enzyme system in female Sprague-Dawley rats following acute expansion of the extracellular fluid volume (ECV). In 57 conscious rats expansion of the ECV with isotonic saline corresponding to an increase in body weight of 10% was induced. Prior to ECV expansion 31 rats received indomethacin (10 mg/kg of body wt) by stomach tube. In six non-ECV-expanded rats indomethacin had no effect on glomerular filtration rate (GFR) and renal plasma flow (RPF). In ECV-expanded rats pretreated with indomethacin, GFR was unaltered but 125I-hippuran clearance decreased, and filtration fraction significantly increased. Intrarenal 86Rb distribution was similar in control and ECV-expanded rats. Indomethacin caused a slight increase in relative cortical 86 RB activity in non-ECV-expanded rats, but had no effect on intrarenal 86Rb distribution in ECV-expanded rats. No difference in intracortical glomerular perfusion was noted between control and ECV-expanded rats. In indomethacin-treated ECV-expanded rats an increase in relative inner cortical perfusion was observed. Absolute perfusion remained unaltered. Thus the decrease in total RPF was entirely due to decreased perfusion of outer cortical nephrons. Renal prostaglandins therefore may play a permissive role for physical factors to promote renal sodium excretion in acute ECV expansion via changes in intrarenal hemodynamics. PMID:890884

  18. Echinacea Species and Alkamides Inhibit Prostaglandin E2 Production in RAW264.7 Mouse Macrophage Cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inhibition of prostaglandin E2 production in lipopolysaccharide-stimulated RAW264.7 mouse macrophage cells was assessed with an enzyme immunoassay following treatments with Echinacea extracts or synthesized alkamides. Results indicated that ethanol extracts from E. angustifolia, E. pallida, E. simu...

  19. Influence of prostaglandins on contractility of the isolated human cervical muscle.

    PubMed

    Bryman, I; Sahni, S; Norström, A; Lindblom, B

    1984-03-01

    The contractile activity of smooth muscle from the pregnant and nonpregnant human cervix uteri was studied in organ bath experiments. Several patterns of spontaneous activity with varying frequency and amplitude were observed. Prostaglandin E2 inhibited muscle activity in a concentration-dependent manner, and total inhibition was achieved in pregnant tissue at extremely low concentrations. Prostaglandin F2 alpha, on the other hand, did not influence spontaneous contractions. Prostaglandin I2 and 6-keto-prostaglandin F1 alpha had an inhibitory effect but only at comparatively high concentrations. 5,8,11,14-Eicosatetraynoic acid and indomethacin abolished spontaneous contractions, indicating a regulatory influence of endogenous prostanoids on cervical contractility. The extreme sensitivity to prostaglandin E2 and enhancement of its action during early pregnancy provide evidence for a specific role of this compound in controlling cervical smooth muscle activity in the human female. PMID:6583598

  20. Prostaglandin E2 inhibits collagen synthesis in dermal fibroblasts and prevents hypertrophic scar formation in vivo.

    PubMed

    Zhao, Jingling; Shu, Bin; Chen, Lei; Tang, Jinming; Zhang, Lijun; Xie, Julin; Liu, Xusheng; Xu, Yingbin; Qi, Shaohai

    2016-08-01

    Hypertrophic scarring is a common dermal fibroproliferative disorder characterized by excessive collagen deposition. Prostaglandin E2 (PGE2 ), an important inflammatory product synthesized via the arachidonic acid cascade, has been shown to act as a fibroblast modulator and to possess antifibroblastic activity. However, the mechanism underlying the antifibrotic effect of PGE2 remains unclear. In this study, we explored the effects of PGE2 on TGF-β1-treated dermal fibroblasts in terms of collagen production and to determine the regulatory pathways involved, as well as understand the antiscarring function of PGE2 in vivo. We found that PGE2 inhibited TGF-β1-induced collagen synthesis by regulating the balance of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP). It did so by upregulating cAMP through the E prostanoid (EP)2 receptor. We determined that inhibition of the TGF-β1/Smad pathway by PGE2 is associated with its ability to inhibit collagen synthesis. An in vivo study further confirmed that PGE2 inhibits hypertrophic scar formation by decreasing collagen production. Our results demonstrate that the novel anti-scarring function of PGE2 is achieved by balancing MMPs/TIMP expression and decreasing collagen production. PMID:26997546

  1. Inhibition of microsomal prostaglandin E synthase-1 by aminothiazoles decreases prostaglandin E2 synthesis in vitro and ameliorates experimental periodontitis in vivo

    PubMed Central

    Kats, Anna; Båge, Tove; Georgsson, Pierre; Jönsson, Jörgen; Quezada, Hernán Concha; Gustafsson, Anders; Jansson, Leif; Lindberg, Claes; Näsström, Karin; Yucel-Lindberg, Tülay

    2013-01-01

    The potent inflammatory mediator prostaglandin E2 (PGE2) is implicated in the pathogenesis of several chronic inflammatory conditions, including periodontitis. The inducible enzyme microsomal prostaglandin E synthase-1 (mPGES-1), catalyzing the terminal step of PGE2 biosynthesis, is an attractive target for selective PGE2 inhibition. To identify mPGES-1 inhibitors, we investigated the effect of aminothiazoles on inflammation-induced PGE2 synthesis in vitro, using human gingival fibroblasts stimulated with the cytokine IL-1β and a cell-free mPGES-1 activity assay, as well as on inflammation-induced bone resorption in vivo, using ligature-induced experimental periodontitis in Sprague-Dawley rats. Aminothiazoles 4-([4-(2-naphthyl)-1,3-thiazol-2-yl]amino)phenol (TH-848) and 4-(3-fluoro-4-methoxyphenyl)-N-(4-phenoxyphenyl)-1,3-thiazol-2-amine (TH-644) reduced IL-1β-induced PGE2 production in fibroblasts (IC50 1.1 and 1.5 μM, respectively) as well as recombinant mPGES-1 activity, without affecting activity or expression of the upstream enzyme cyclooxygenase-2. In ligature-induced experimental periodontitis, alveolar bone loss, assessed by X-ray imaging, was reduced by 46% by local treatment with TH-848, compared to vehicle, without any systemic effects on PGE2, 6-keto PGF1α, LTB4 or cytokine levels. In summary, these results demonstrate that the aminothiazoles represent novel mPGES-1 inhibitors for inhibition of PGE2 production and reduction of bone resorption in experimental periodontitis, and may be used as potential anti-inflammatory drugs for treatment of chronic inflammatory diseases, including periodontitis.—Kats, A., Båge, T., Georgsson, P., Jönsson, J., Quezada, H. C., Gustafsson, A., Jansson, L., Lindberg, C., Näsström, K., Yucel-Lindberg, T. Inhibition of microsomal prostaglandin E synthase-1 by aminothiazoles decreases prostaglandin E2 synthesis in vitro and ameliorates experimental periodontitis in vivo. PMID:23447581

  2. The novel hypoxic cytotoxin, TX-2098 has antitumor effect in pancreatic cancer; possible mechanism through inhibiting VEGF and hypoxia inducible factor-1{alpha} targeted gene expression

    SciTech Connect

    Miyake, Kotaro; Nishioka, Masanori; Imura, Satoru; Batmunkh, Erdenebulgan; Uto, Yoshihiro; Nagasawa, Hideko; Hori, Hitoshi; Shimada, Mitsuo

    2012-08-01

    Tumor hypoxia has been considered to be a potential therapeutic target, because hypoxia is a common feature of solid tumors and is associated with their malignant phenotype. In the present study, we investigated the antitumor effect of a novel hypoxic cytotoxin, 3-[2-hydroxyethyl(methyl)amino]-2-quinoxalinecarbonitrile 1,4-dioxide (TX-2098) in inhibiting the expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}), and consequently vascular endothelial cell growth factor (VEGF) expression in pancreatic cancer. The antitumor effects of TX-2098 under hypoxia were tested against various human pancreatic cancer cell lines using WST-8 assay. VEGF protein induced pancreatic cancer was determined on cell-free supernatant by ELISA. Moreover, nude mice bearing subcutaneously (s.c.) or orthotopically implanted human SUIT-2 were treated with TX-2098. Tumor volume, survival and expression of HIF-1 and associated molecules were evaluated in treatment versus control groups. In vitro, TX-2098 inhibited the proliferation of various pancreatic cancer cell lines. In s.c model, tumors from nude mice injected with pancreatic cancer cells and treated with TX-2098 showed significant reductions in volume (P < 0.01 versus control). Quantitative real-time reverse transcription-PCR analysis revealed that TX-2098 significantly inhibited mRNA expression of the HIF-1 associated molecules, VEGF, glucose transporter 1 and Aldolase A (P < 0.01 versus control). These treatments also prolong the survival in orthotopic models. These results suggest that the effect of TX-2098 in pancreatic cancer might be correlated with the expression of VEGF and HIF-1 targeted molecules. -- Highlights: Black-Right-Pointing-Pointer We designed and synthesized novel hypoxic cytoxin, TX-2098. Black-Right-Pointing-Pointer TX-2098 inhibited the proliferation of human pancreatic cancer cells than TPZ. Black-Right-Pointing-Pointer TX-2098 reduced VEGF protein level than TPZ. Black-Right-Pointing-Pointer TX-2098

  3. Prostaglandin E2 inhibits apoptosis in human neutrophilic polymorphonuclear leukocytes: role of intracellular cyclic AMP levels.

    PubMed

    Ottonello, L; Gonella, R; Dapino, P; Sacchetti, C; Dallegri, F

    1998-08-01

    Human neutrophilic polymorphonuclear leukocytes (neutrophils) are terminally differentiated cells that die by undergoing apoptosis. At present, the intracellular pathways governing this process are only partially known. In particular, although the adenylate cyclase-dependent generation of cyclic AMP (cAMP) has been implicated in the triggering of apoptosis in lymphoid cells, the role of the intracellular cAMP pathway in neutrophil apoptosis remains controversial. In the present study, we found that two cAMP-elevating agents, prostaglandin E2 (PGE2) and the phosphodiesterase type IV inhibitor RO 20-1724, inhibit neutrophil apoptosis without inducing cell necrosis. When administered in combination, PGE2 and RO 20-1724 displayed additive effects. Moreover, neutrophil apoptosis was inhibited by a membrane-permeable analog of cAMP, dibutyryl-cAMP, in a dose-dependent manner. Finally, treatment of neutrophils with the protein kinase A inhibitor H-89 prevented PGE2- and RO 20-1724-induced inhibition of cell apoptosis. In conclusion, taking into account that PGE2 and other cAMP-elevating agents are well known downregulators of neutrophil functions, our results suggest that conditions favoring a state of functional rest, such as intracellular cAMP elevation, prolong the life span of neutrophils by delaying apoptosis. PMID:9694511

  4. Opposing effects of nitric oxide and prostaglandin inhibition on muscle mitochondrial Vo(2) during exercise.

    PubMed

    Boushel, Robert; Fuentes, Teresa; Hellsten, Ylva; Saltin, Bengt

    2012-07-01

    Nitric oxide (NO) and prostaglandins (PG) together play a role in regulating blood flow during exercise. NO also regulates mitochondrial oxygen consumption through competitive binding to cytochrome-c oxidase. Indomethacin uncouples and inhibits the electron transport chain in a concentration-dependent manner, and thus, inhibition of NO and PG synthesis may regulate both muscle oxygen delivery and utilization. The purpose of this study was to examine the independent and combined effects of NO and PG synthesis blockade (L-NMMA and indomethacin, respectively) on mitochondrial respiration in human muscle following knee extension exercise (KEE). Specifically, this study examined the physiological effect of NO, and the pharmacological effect of indomethacin, on muscle mitochondrial function. Consistent with their mechanism of action, we hypothesized that inhibition of nitric oxide synthase (NOS) and PG synthesis would have opposite effects on muscle mitochondrial respiration. Mitochondrial respiration was measured ex vivo by high-resolution respirometry in saponin-permeabilized fibers following 6 min KEE in control (CON; n = 8), arterial infusion of N(G)-monomethyl-L-arginine (L-NMMA; n = 4) and Indo (n = 4) followed by combined inhibition of NOS and PG synthesis (L-NMMA + Indo, n = 8). ADP-stimulated state 3 respiration (OXPHOS) with substrates for complex I (glutamate, malate) was reduced 50% by Indo. State 3 O(2) flux with complex I and II substrates was reduced less with both Indo (20%) and L-NMMA + Indo (15%) compared with CON. The results indicate that indomethacin reduces state 3 mitochondrial respiration primarily at complex I of the respiratory chain, while blockade of NOS by L-NMMA counteracts the inhibition by Indo. This effect on muscle mitochondria, in concert with a reduction of blood flow accounts for in vivo changes in muscle O(2) consumption during combined blockade of NOS and PG synthesis. PMID:22552792

  5. 15-deoxy prostaglandin J2, the nonenzymatic metabolite of prostaglandin D2, induces apoptosis in keratinocytes of human hair follicles: a possible explanation for prostaglandin D2-mediated inhibition of hair growth.

    PubMed

    Joo, Hyun Woo; Kang, Yoo Ri; Kwack, Mi Hee; Sung, Young Kwan

    2016-07-01

    Recent studies have shown that prostaglandin D2 (PGD2) and its nonenzymatic metabolite, 15-deoxy-Δ(12,14)-prostaglandin J2 (15-dPGJ2), inhibit in vitro growth of explanted human hair follicles and inhibit hair growth in mice through the GPR44 (DP2). However, the underlying mechanism is still unclear. In this study, we first investigated the expression of DP2 in human hair follicles and in cultured follicular cells. We found that DP2 is strongly expressed in the outer root sheath (ORS) cells and weakly expressed in the dermal papilla (DP) cells. We observed slight growth stimulation when ORS and DP cells were treated with PGD2. We also observed slight growth stimulation when DP and ORS cells were treated with low concentrations (0.5 and 1 μM) of 15-dPGJ2. However, 5 μM 15-dPGJ2 inhibited the viability and caused apoptosis of both cell types. Exposure of cultured human hair follicles to 15-dPGJ2 resulted in significant apoptosis in follicular keratinocytes. Altogether, our data provide an evidence that 15-dPGJ2 promotes apoptosis in follicular keratinocytes and provide rationale for developing remedies for the prevention and treatment of hair loss based on DP2 antagonism. PMID:27185495

  6. 1Alpha,25-dihydroxyvitamin D3 inhibits programmed cell death in HL-60 cells by activation of sphingosine kinase.

    PubMed

    Kleuser, B; Cuvillier, O; Spiegel, S

    1998-05-01

    Sphingolipid breakdown products [ceramide, sphingosine, and sphingosine-1-phosphate (SPP)] are emerging as a new class of bioactive molecules. In agreement with previous studies, treatment of human promyelocytic leukemia HL-60 cells with 1-alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3] induced a transient increase of ceramide levels within 2 h, which then returned to basal levels within 8 h. In contrast, sphingosine kinase activity increased more slowly and reached maximal levels only after 20 h of exposure, leading to a concomitant increase in SPP level. Unlike treatments with cell-permeable ceramide analogues or sphingomyelinase, which induce apoptosis, 1,25-(OH)2D3 did not induce apoptosis, despite the early formation of ceramide. Moreover, prolonged treatment of HL-60 cells with 1,25-(OH)2D3 suppressed ceramide-induced apoptosis. There was a correlation between the time course and dose response of the activation of sphingosine kinase by 1,25-(OH)2D3 and the protection against apoptosis. In contrast, treatment with all-trans-retinoic acid neither stimulated sphingosine kinase activity nor protected cells from ceramide-induced apoptosis. Treatment with SPP protected HL-60 cells from ceramide-induced apoptosis, and N,N-dimethylsphingosine (DMS), a competitive inhibitor of sphingosine kinase, prevented the survival effect of 1,25-(OH)2D3. The effect of DMS was counteracted by SPP, suggesting that SPP is a critical component of the cytoprotective effect of 1,25-(OH)2D3. Chelerythrine chloride, an inhibitor of protein kinase C, markedly reduced sphingosine kinase activity and the apoptosis-sparing effect of 1,25-(OH)2D3, and conversely, the tumor promoter 12-O-tetradecanoylphorhol-13-acetate not only suppressed ceramide-induced apoptosis but also stimulated sphingosine kinase activity. Moreover, the protective effect of 12-O-tetradecanoylphorbol-13-acetate was blocked by DMS. Collectively, our observations indicate that the cytoprotective effect of 1,25-(OH)2D3 is

  7. A novel MyD-1 (SIRP-1alpha) signaling pathway that inhibits LPS-induced TNFalpha production by monocytes.

    PubMed

    Smith, Rosemary E; Patel, Vanshree; Seatter, Sandra D; Deehan, Maureen R; Brown, Marion H; Brooke, Gareth P; Goodridge, Helen S; Howard, Christopher J; Rigley, Kevin P; Harnett, William; Harnett, Margaret M

    2003-10-01

    MyD-1 (CD172) is a member of the family of signal regulatory phosphatase (SIRP) binding proteins, which is expressed on human CD14+ monocytes and dendritic cells. We now show a novel role for MyD-1 in the regulation of the innate immune system by pathogen products such as lipopolysaccharide (LPS), purified protein derivative (PPD), and Zymosan. Specifically, we demonstrate that ligation of MyD-1 on peripheral blood mononuclear cells (PBMCs) inhibits tumor necrosis factor alpha (TNFalpha) secretion but has no effect on other cytokines induced in response to each of these products. In an attempt to understand the molecular mechanisms underlying this surprisingly selective effect we investigated signal transduction pathways coupled to MyD-1. Ligation of the SIRP was found to recruit the tyrosine phosphatase SHP-2 and promote sequential activation of phosphatidylinositol (PI) 3-kinase, phospholipase D, and sphingosine kinase. Inhibition of LPS-induced TNFalpha secretion by MyD-1 appears to be mediated by this pathway, as the PI 3-kinase inhibitor wortmannin restores normal LPS-driven TNFalpha secretion. MyD-1-coupling to this PI 3-kinase-dependent signaling pathway may therefore present a novel target for the development of therapeutic strategies for combating TNFalpha production and consequent inflammatory disease. PMID:12805067

  8. Carnosol and Carnosic Acids from Salvia officinalis Inhibit Microsomal Prostaglandin E2 Synthase-1

    PubMed Central

    Bauer, Julia; Kuehnl, Susanne; Rollinger, Judith M.; Scherer, Olga; Northoff, Hinnak; Stuppner, Hermann; Werz, Oliver; Koeberle, Andreas

    2012-01-01

    Prostaglandin E2 (PGE2), the most relevant eicosanoid promoting inflammation and tumorigenesis, is formed by cyclooxygenases (COXs) and PGE2 synthases from free arachidonic acid. Preparations of the leaves of Salvia officinalis are commonly used in folk medicine as an effective antiseptic and anti-inflammatory remedy and possess anticancer activity. Here, we demonstrate that a standard ethyl acetate extract of S. officinalis efficiently suppresses the formation of PGE2 in a cell-free assay by direct interference with microsomal PGE2 synthase (mPGES)-1. Bioactivity-guided fractionation of the extract yielded closely related fractions that potently suppressed mPGES-1 with IC50 values between 1.9 and 3.5 μg/ml. Component analysis of these fractions revealed the diterpenes carnosol and carnosic acid as potential bioactive principles inhibiting mPGES-1 activity with IC50 values of 5.0 μM. Using a human whole-blood assay as a robust cell-based model, carnosic acid, but not carnosol, blocked PGE2 generation upon stimulation with lipopolysaccharide (IC50 = 9.3 μM). Carnosic acid neither inhibited the concomitant biosynthesis of other prostanoids [6-keto PGF1α, 12(S)-hydroxy-5-cis-8,10-trans-heptadecatrienoic acid, and thromboxane B2] in human whole blood nor affected the activities of COX-1/2 in a cell-free assay. Together, S. officinalis extracts and its ingredients carnosol and carnosic acid inhibit PGE2 formation by selectively targeting mPGES-1. We conclude that the inhibitory effect of carnosic acid on PGE2 formation, observed in the physiologically relevant whole-blood model, may critically contribute to the anti-inflammatory and anticarcinogenic properties of S. officinalis. PMID:22511203

  9. Combined inhibition of nitric oxide and prostaglandins reduces human skeletal muscle blood flow during exercise

    PubMed Central

    Boushel, Robert; Langberg, Henning; Gemmer, Carsten; Olesen, Jens; Crameri, Regina; Scheede, Celena; Sander, Michael; Kjær, Michael

    2002-01-01

    The vascular endothelium is an important mediator of tissue vasodilatation, yet the role of the specific substances, nitric oxide (NO) and prostaglandins (PG), in mediating the large increases in muscle perfusion during exercise in humans is unclear. Quadriceps microvascular blood flow was quantified by near infrared spectroscopy and indocyanine green in six healthy humans during dynamic knee extension exercise with and without combined pharmacological inhibition of NO synthase (NOS) and PG by l-NAME and indomethacin, respectively. Microdialysis was applied to determine interstitial release of PG. Compared to control, combined blockade resulted in a 5- to 10-fold lower muscle interstitial PG level. During control incremental knee extension exercise, mean blood flow in the quadriceps muscles rose from 10 ± 0.8 ml (100 ml tissue)−1 min−1 at rest to 124 ± 19, 245 ± 24, 329 ± 24 and 312 ± 25 ml (100 ml tissue)−1 min−1 at 15, 30, 45 and 60 W, respectively. During inhibition of NOS and PG, blood flow was reduced to 8 ± 0.5 ml (100 ml tissue)−1 min−1 at rest, and 100 ± 13, 163 ± 21, 217 ± 23 and 256 ± 28 ml (100 ml tissue)−1 min−1 at 15, 30, 45 and 60 W, respectively (P < 0.05 vs. control). In conclusion, combined inhibition of NOS and PG reduced muscle blood flow during dynamic exercise in humans. These findings demonstrate an important synergistic role of NO and PG for skeletal muscle vasodilatation and hyperaemia during muscular contraction. PMID:12205200

  10. Berberine, an isoquinoline alkaloid, inhibits melanoma cancer cell migration by reducing the expressions of cyclooxygenase-2, prostaglandin E2 and prostaglandin E2 receptors

    PubMed Central

    Singh, Tripti; Vaid, Mudit; Katiyar, Nandan; Sharma, Samriti; Katiyar, Santosh K.

    2011-01-01

    Melanoma is the leading cause of death from skin disease due, in large part, to its propensity to metastasize. We have examined the effect of berberine, an isoquinoline alkaloid, on human melanoma cancer cell migration and the molecular mechanisms underlying these effects using melanoma cell lines, A375 and Hs294. Using an in vitro cell migration assay, we show that over expression of cyclooxygenase (COX)-2, its metabolite prostaglandin E2 (PGE2) and PGE2 receptors promote the migration of cells. We found that treatment of A375 and Hs294 cells with berberine resulted in concentration-dependent inhibition of migration of these cells, which was associated with a reduction in the levels of COX-2, PGE2 and PGE2 receptors (EP2 and EP4). Treatment of cells with celecoxib, a COX-2 inhibitor, or transient transfection of cells with COX-2 small interfering RNA, also inhibited cell migration. Treatment of the cells with 12-O-tetradecanoylphorbol-13-acetate (TPA), an inducer of COX-2 or PGE2, enhanced cell migration, whereas berberine inhibited TPA- or PGE2-promoted cell migration. Berberine reduced the basal levels as well as PGE2-stimulated expression levels of EP2 and EP4. Treatment of the cells with the EP4 agonist stimulated cell migration and berberine blocked EP4 agonist-induced cell migration activity. Moreover, berberine inhibited the activation of nuclear factor-kappa B (NF-κB), an upstream regulator of COX-2, in A375 cells, and treatment of cells with caffeic acid phenethyl ester, an inhibitor of NF-κB, inhibited cell migration. Together, these results indicate for the first time that berberine inhibits melanoma cell migration, an essential step in invasion and metastasis, by inhibition of COX-2, PGE2 and PGE2 receptors. PMID:20974686

  11. Prostaglandin E2-increased thermosensitivity of anterior hypothalamic neurons is associated with depressed inhibition.

    PubMed

    Tabarean, Iustin V; Behrens, M Margarita; Bartfai, Tamas; Korn, Henri

    2004-02-24

    Temperature responses of anterior hypothalamic neurons are considered key elements in the regulation of the temperature setpoint of homeotherms. We have investigated the sensitivity to warming of cultured neurons of the AH from mice with electrophysiological and immunocytochemical techniques. In control experiments, only approximately 9% of the 3- to 5-week-old cells exhibited changes of their basic firing rate when the temperature was raised from 37 degrees C to 40 degrees C. This ratio was increased to 27% after the cultures were "primed" by adding prostaglandin E2 (PGE2), an endogenous pyrogen, in the extracellular medium. In these neurons the firing rate was significantly increased, and the frequency of the gamma gamma-aminobutyric acid (GABA) inhibitory postsynaptic potentials was markedly decreased. In contrast, the resting potential and membrane resistance of the recorded cells remained unchanged. PGE2 was found to decrease the level of phosphorylation of the extracellular signal-regulated kinases 1 and 2 in a subset of GABAergic neurons that express the E-prostanoid receptor type 3. Inhibition of ERK1/2 by U0126 mimicked the effects of PGE2. These data indicate that PGE2 acts primarily on the excitability of GABAergic presynaptic cells, most likely via alterations of voltage-gated K+ channels. Our results also suggest that far from being an inherent property of a specialized class of neurons, the degree of thermosensitivity can be strongly modulated by synaptic activity and is a more adaptive property of hypothalamic neurons than previously thought. PMID:14983053

  12. p-Benzoquinone, a reactive metabolite of benzene, prevents the processing of pre-interleukins-1{alpha} and -1{beta} to active cytokines by inhibition of the processing enzymes, calpain, and interleukin-1{beta} converting enzyme

    SciTech Connect

    Kalf, G.F.; Renz, J.F.; Niculescu, R.

    1996-12-01

    Chronic exposure of humans to benzene affects hematopoietic stem and progenitor cells and leads to aplastic anemia. The stromal macrophage, a target of benzene toxicity, secretes interieukin-1 (IL-1), which induces the stromal fibroblast to synthesize hematopoietic colony-stimulating factors. In a mouse model, benzene causes an acute marrow hypocellularity that can be prevented by the concomitant administration of IL-1{alpha}. The ability of benzene to interfere with the production and secretion of IL-1{alpha} was tested. Stromal macrophages from benzene-treated mice were capable of the transcription of the IL-1{alpha} gene and the translation of the message but showed an inability to process the 34-kDa pre-IL-1{alpha} precursor to the 17-kDa biologically active cytokine. Treatment of normal murine stromal macrophages in culture with hydroquinone (HQ) also showed an inhibition in processing of pre-IL-1{alpha}. Hydroquinone is oxidized by a peroxidase-mediated reaction in the stromal macrophage to p-benzoquinone, which interacts with the sulfhydryl (SH) groups of proteins and was shown to completely inhibit the activity of calpain, the SH-dependent protease that cleaves pre-IL-1{alpha}. In a similar manner, HQ, via peroxidase oxidation to p-benzoquinone, was capable of preventing the IL-1{beta} autocrine stimulation of growth of human B1 myeloid tumor cells by preventing the processing of pre-IL-1{beta} to mature cytokine. Benzoquinone was also shown to completely inhibit the ability of the SH-dependent IL-1{beta} converting enzyme. Thus benzene-induced bone marrow hypocellularity may result from apoptosis of hematopoietic progenitor cells brought about by lack of essential cylokines and deficient IL-1{alpha} production subsequent to the inhibition of calpain by p-benzoquinone and the prevention of pre-IL-1 processing. 34 refs., 8 figs.

  13. Vitexin reduces hypoxia-ischemia neonatal brain injury by the inhibition of HIF-1alpha in a rat pup model.

    PubMed

    Min, Jia-Wei; Hu, Jiang-Jian; He, Miao; Sanchez, Russell M; Huang, Wen-Xian; Liu, Yu-Qiang; Bsoul, Najeeb Bassam; Han, Song; Yin, Jun; Liu, Wan-Hong; He, Xiao-Hua; Peng, Bi-Wen

    2015-12-01

    Previous studies have demonstrated that the early suppression of HIF-1α after hypoxia-ischemia (HI) injury provides neuroprotection. Vitexin (5, 7, 4-trihydroxyflavone-8-glucoside), an HIF-1α inhibitor, is a c-glycosylated flavone that has been identified in medicinal plants. Therefore, we hypothesized that treatment with vitexin would protect against HI brain injury. Newborn rat pups were subjected to unilateral carotid artery ligation followed by 2.5 h of hypoxia (8% O2 at 37 °C). Vitexin (30, 45 or 60 mg/kg) was administered intraperitoneally at 5 min or 3 h after HI. Vitexin, administered 5 min after HI, was neuroprotective as seen by decreased infarct volume evaluated at 48 h post-HI. This neuroprotection was removed when vitexin was administered 3 h after HI. Neuronal cell death, blood-brain barrier (BBB) integrity, brain edema, HIF-1α and VEGF protein levels were evaluated using a combination of Nissl staining, IgG staining, brain water content, immunohistochemistry and Western blot at 24 and 48 h after HI. The long-term effects of vitexin were evaluated by brain atrophy measurement, Nissl staining and neurobehavioral tests. Vitexin (45 mg/kg) ameliorated brain edema, BBB disruption and neuronal cell death; Upregulation of HIF-1α by dimethyloxalylglycine (DMOG) increased the BBB permeability and brain edema compared to HI alone. Vitexin attenuated the increase in HIF-1α and VEGF. Vitexin also had long-term effects of protecting against the loss of ipsilateral brain and improveing neurobehavioral outcomes. In conclusion, our data indicate early HIF-1α inhibition with vitexin provides both acute and long-term neuroprotection in the developing brain after neonatal HI injury. PMID:26187393

  14. Prostaglandin E2-increased thermosensitivity of anterior hypothalamic neurons is associated with depressed inhibition

    PubMed Central

    Tabarean, Iustin V.; Behrens, M. Margarita; Bartfai, Tamas; Korn, Henri

    2004-01-01

    Temperature responses of anterior hypothalamic neurons are considered key elements in the regulation of the temperature setpoint of homeotherms. We have investigated the sensitivity to warming of cultured neurons of the AH from mice with electrophysiological and immunocytochemical techniques. In control experiments, only ≈9% of the 3- to 5-week-old cells exhibited changes of their basic firing rate when the temperature was raised from 37°C to 40°C. This ratio was increased to 27% after the cultures were “primed” by adding prostaglandin E2 (PGE2), an endogenous pyrogen, in the extracellular medium. In these neurons the firing rate was significantly increased, and the frequency of the gamma γ-aminobutyric acid (GABA) inhibitory postsynaptic potentials was markedly decreased. In contrast, the resting potential and membrane resistance of the recorded cells remained unchanged. PGE2 was found to decrease the level of phosphorylation of the extracellular signal-regulated kinases 1 and 2 in a subset of GABAergic neurons that express the E-prostanoid receptor type 3. Inhibition of ERK1/2 by U0126 mimicked the effects of PGE2. These data indicate that PGE2 acts primarily on the excitability of GABAergic presynaptic cells, most likely via alterations of voltage-gated K+ channels. Our results also suggest that far from being an inherent property of a specialized class of neurons, the degree of thermosensitivity can be strongly modulated by synaptic activity and is a more adaptive property of hypothalamic neurons than previously thought. PMID:14983053

  15. 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

  16. Inhibition of Protein Kinase C Delta Attenuates Allergic Airway Inflammation through Suppression of PI3K/Akt/mTOR/HIF-1 Alpha/VEGF Pathway

    PubMed Central

    Li, Liang chang; Yan, Guang Hai

    2013-01-01

    Vascular endothelial growth factor (VEGF) is supposed to contribute to the pathogenesis of allergic airway disease. VEGF expression is regulated by a variety of stimuli such as nitric oxide, growth factors, and hypoxia-inducible factor-1 alpha (HIF-1α). Recently, inhibition of the mammalian target of rapamycin (mTOR) has been shown to alleviate cardinal asthmatic features, including airway hyperresponsiveness, eosinophilic inflammation, and increased vascular permeability in asthma models. Based on these observations, we have investigated whether mTOR is associated with HIF-1α-mediated VEGF expression in allergic asthma. In studies with the mTOR inhibitor rapamycin, we have elucidated the stimulatory role of a mTOR-HIF-1α-VEGF axis in allergic response. Next, the mechanisms by which mTOR is activated to modulate this response have been evaluated. mTOR is known to be regulated by phosphoinositide 3-kinase (PI3K)/Akt or protein kinase C-delta (PKC δ) in various cell types. Consistent with these, our results have revealed that suppression of PKC δ by rottlerin leads to the inhibition of PI3K/Akt activity and the subsequent blockade of a mTOR-HIF-1α-VEGF module, thereby attenuating typical asthmatic attack in a murine model. Thus, the present data indicate that PKC δ is necessary for the modulation of the PI3K/Akt/mTOR signaling cascade, resulting in a tight regulation of HIF-1α activity and VEGF expression. In conclusion, PKC δ may represent a valuable target for innovative therapeutic treatment of allergic airway disease. PMID:24312355

  17. The effect of vitreous humour on prostaglandin production by cultured rabbit chorioretinal fibroblasts.

    PubMed

    Martin, C E; Croft, K D; van Bockxmeer, F M; Constable, I J

    1987-12-10

    Factors in vitreous humour which regulate prostaglandin production were investigated using cultured rabbit chorioretinal fibroblasts. These cells produced predominantly prostaglandin E2, 6-ketoprostaglandin F1 alpha, a compound likely to be a metabolite of prostaglandin E2 and 5-hydroxyeicosatetraenoic acid. The synthesis of 6-ketoprostaglandin F1 alpha was nearly completely inhibited by the cyclooxygenase inhibitor aspirin and partially inhibited by 10(-6) M dexamethasone (49%) and 10(-5) M forskolin (68%). Addition of 10% rabbit vitreous humour to subconfluent cells maintained in Dulbecco's modified Eagle's medium plus 1% fetal bovine serum resulted in stimulation of 6-ketoprostaglandin F1 alpha production by as much as 246% as measured by radioimmunoassay. Chorioretinal fibroblasts labelled by [3H]arachidonic acid incorporation into cellular phospholipids synthesised greater amounts of all labelled arachidonic acid metabolites in response to vitreous humour. It was concluded, therefore, that there are factors present in vitreous humour of molecular weight above 10 kDa which are capable of stimulating cellular cyclooxygenase activity. Confluent cells also responded to a factor(s) present in vitreous humour. The fraction of less than 10 kDa inhibited 6-ketoprostaglandin F1 alpha production by 50% when used at a concentration of 10%. Furthermore, 6-ketoprostaglandin F1 alpha production in confluent cells (but not subconfluent cells) was inhibited to 40% of control levels by vitamin C at a concentration of 1 mg/100 ml. The latter result points to an inhibitory role for vitamin C in vitreous humour. We conclude, therefore, that vitreous humour contains factors important for the regulation of prostaglandin metabolism in the eye. PMID:3118960

  18. The TATA-containing core promoter of the type II collagen gene (COL2A1) is the target of interferon-gamma-mediated inhibition in human chondrocytes: requirement for Stat1 alpha, Jak1 and Jak2.

    PubMed Central

    Osaki, Makoto; Tan, Lujian; Choy, Bob K; Yoshida, Yasuhiro; Cheah, Kathryn S E; Auron, Philip E; Goldring, Mary B

    2003-01-01

    Interferon-gamma (IFN-gamma) inhibits the synthesis of the cartilage-specific extracellular matrix protein type II collagen, and suppresses the expression of the type II collagen gene ( COL2A1 ) at the transcriptional level. To further examine this mechanism, the responses of COL2A1 regulatory sequences to IFN-gamma and the role of components of the Janus kinase/signal transducer and activators of transcription (JAK/STAT) pathway were examined in the immortalized human chondrocyte cell line, C-28/I2. IFN-gamma inhibited the mRNA levels of COL2A1 and aggrecan, but not Sox9, L-Sox5 and Sox6, all of which were expressed by these cells as markers of the differentiated phenotype. IFN-gamma suppressed the expression of luciferase reporter constructs containing sequences of the COL2A1 promoter spanning -6368 to +125 bp in the absence and presence of the intronic enhancer and stimulated activity of the gamma-interferon-activated site (GAS) luciferase reporter vector, associated with induction of Stat1 alpha-binding activity in nuclear extracts. These responses to IFN-gamma were blocked by overexpression of the JAK inhibitor, JAK-binding protein (JAB), or reversed by dominant-negative Stat1 alpha Y701F containing a mutation at Tyr-701, the JAK phosphorylation site. IFN-gamma had no effect on COL2A1 promoter expression in Jak1 (U4A)-, Jak2 (gamma 2A)- and Stat1 alpha (U3A)-deficient cell lines. In the U3A cell line, the response to IFN-gamma was rescued by overexpression of Stat1 alpha, but not by either Stat1 alpha Y701F or Stat1 beta. Functional analysis using deletion constructs showed that the IFN-gamma response was retained in the COL2A1 core promoter region spanning -45 to +11 bp, containing the TATA-box and GC-rich sequences but no Stat1-binding elements. Inhibition of COL2A1 promoter activity by IFN-gamma persisted in the presence of multiple deletions within the -45/+11 bp region. Our results indicate that repression of COL2A1 gene transcription by IFN

  19. Oxysophocarpine Ameliorates Carrageenan-induced Inflammatory Pain via Inhibiting Expressions of Prostaglandin E2 and Cytokines in Mice.

    PubMed

    Yang, Yang; Li, Yu-Xiang; Wang, Hong-Ling; Jin, Shao-Ju; Zhou, Ru; Qiao, Hai-Qi; Du, Juan; Wu, Jing; Zhao, Cheng-Jun; Niu, Yang; Sun, Tao; Yu, Jian-Qiang

    2015-07-01

    Oxysophocarpine is an alkaloid extracted from Sophora alopecuroides. We investigated the analgesic effect of oxysophocarpine on carrageenan-induced inflammatory pain in mice, in order to explore its possible mechanisms. Mouse ear swelling tests and carrageenan-induced paw edema tests were used to investigate the effects of oxysophocarpine on inflammatory pain in mice. Morphological changes on inflamed paw sections were measured by hematoxylin-eosin staining. The mRNA and protein expression of extracellular signal-regulated kinase, phosphorylation of extracellular signal-regulated kinase 1/2, cyclooxygenase-2, tumor necrosis factor α, interleukin-1 beta, interleukin-6 and prostaglandin E2 were investigated by real-time quantitative polymerase chain reaction, immunohistochemistry, western-blot and enzyme-linked immunosorbent assay. In our results, oxysophocarpine shows a significant anti-inflammatory effect in the mouse ear swelling test. Oxysophocarpine also significantly reduced the paw edema volume and improved mechanical allodynia threshold value on carrageenan-induced inflammatory pain, as well as relieved paw tissues inflammatory damage and reduced the numbers of neutrophils in mice. Oxysophocarpine significantly suppressed over-expression of cyclooxygenase-2, tumor necrosis factor α, interleukin-1 beta, interleukin-6 and prostaglandin E2, and inhibited the over-phosphorylation of extracellular signal-regulated kinase 1/2. Based on these findings we propose that oxysophocarpine attenuates inflammatory pain by suppressing the levels of phosphorylation of extracellular signal-regulated kinase 1/2, cyclooxygenase-2, prostaglandin E2, tumor necrosis factor α, interleukin-1 beta and interleukin-6. PMID:26132856

  20. Inhibition of Lung Carcinogenesis by 1alpha,25-dihydroxyvitamin D3 and 9-cis Retinoic Acid in the A/J Mouse Model: Evidence of Retinoid Mitigation of Vitamin D Toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    9-cis-retinoic acid (9cRA) and 1alpha,25-dihydroxyvitamin D3 (1,25D) show promise as potential chemopreventive agents. We examined 9cRA and 1,25D, alone and in combination, for their potential to inhibit carcinogen (NNK)-induced lung carcinogenesis in A/J mice. A/J mice (n=14/group) were treated wit...

  1. [Inhibition of initial puerperal and postabortion lactation using oral prostaglandin E2 (Dinoprostone)].

    PubMed

    Berić, B; Mitreski, A; Kuzmancev, O; Curcić, A; Ilić, V; Vukelić, J; Budakov, D

    1992-01-01

    Authors present their experience in oral administration of Prostaglandin E2 (Dinoproston, Upjohn) during postpartal and postabortal period (à 0.5 mg after legal pregnancy interruption) in suppression of lactation. Indications for postpartal lactation suppression were such as: stillbirth, postpartal neonatal death and maternal negative attitude towards breast feeding. The patients in whom the suppression of lactation was applied were of generative age (18-40 years) either primiparas or multiparas. All were delivered vaginally with no extra intrapartal or postpartal complications being the same in legal pregnancy interruptions which were performed by application of intravaginal, intracervical and intramuscular Prostaglandin preparations. The patients were administered 1 tbl od 0.5 mg Dinoproston preparation every 6-7 hours, 48 h after the delivery, i.e. 2 tbl in total (after meal). This method of lactation suppression was applied in 50 patients during 1990. Satisfactory results were achieved in all cases, while negative side effects and complications were not noted. Oral administration of PGE2 was found very efficient in postpartal and postabortal lactation suppression while compared with previously applied methods such as Estrogen-Testosterone preparation, i.e. small doses of Bromergon applied during 10-14 days. Oral administration of PG2 is more efficient and in a certain way more comfortable in relation to the previously applied methods. PMID:1344441

  2. Neurogenic contractions in intraocular porcine ciliary arteries are mediated by α₂-adrenoceptors and NPY₁ receptors and are inhibited by prostaglandin E₂ acting on prejunctional EP₄ receptors.

    PubMed

    Kringelholt, Sidse; Simonsen, Ulf; Bek, Toke

    2013-02-01

    Prostaglandin analogues and adrenergic drugs are used to reduce the intraocular pressure in glaucoma, which may partly be due to an effect on the tone of the intraocular arteries supplying the ciliary body. The aim of the present study was to investigate the interaction between prostaglandins and autonomic nervous activity induced by electrical stimulation of the tone in these ciliary vessels. The intraocular part of porcine ciliary arteries were isolated and mounted in a microvascular myograph for isometric tension recordings, and the effect of prostaglandin E(2) on electrically induced contractions was studied in the presence of selective EP receptor antagonists. PGE(2) induced concentration-dependent inhibition of electrically induced contractions of intraocular ciliary arteries which depended on the presence of the vascular endothelium. The effect of PGE(2) was blocked by an EP(4) receptor antagonist but not by an EP(1) receptor antagonist. The neurogenic contractions were partially inhibited by an α(2)-adrenoceptor antagonist and totally inhibited by a NPY(1) receptor antagonist. The effect of these antagonists was similar when contraction was induced by noradrenaline and NPY. Neurogenic contractions in intraocular porcine arteries are mediated by α(2)-adrenoceptors and NPY(1) receptors and can be inhibited by PGE(2) acting on prejunctional EP(4) receptors. This contributes to a further understanding of the role of the autonomic nervous system and prostaglandins for regulating blood flow to the anterior segment of the eye. PMID:23178872

  3. Prostaglandin synthetase inhibition with indomethacin rectal suppositories in the treatment of acute and chronic urinary calculus obstruction.

    PubMed

    Al-Waili, N S

    1986-03-01

    The effect of indomethacin suppositories on both acute urinary colic and urinary calculus, resistant or refractory to conventional therapy with analgesics and spasmolytics was investigated. Fifty-five patients with acute urinary colic refractory to treatment with repeated injections of antispasmodics and analgesics had dramatic or complete pain relief after receiving indomethacin suppositories (100 mg) (P less than 0.01). Fifteen of the 55 patients passed urinary stones within 30 days of treatment with indomethacin. Three out of 30 other patients with renal or ureteric stones were treated with indomethacin suppositories (100 mg) twice daily. Twenty-one of the 30 patients passed their stones within 30 days of treatment. It is concluded that indomethacin suppositories can relieve acute urinary colic resistant to treatment with analgesic/antispasmodic drugs, and facilitate expulsion of urinary calculi. The mechanism of action of indomethacin is discussed in terms of its analgesic and anti-inflammatory effects and its prostaglandin synthesis inhibition. PMID:3720020

  4. Aqueous Extract of Paris polyphylla (AEPP) Inhibits Ovarian Cancer via Suppression of Peroxisome Proliferator-Activated Receptor-Gamma Coactivator (PGC)-1alpha.

    PubMed

    Wang, Chia-Woei; Tai, Cheng-Jeng; Choong, Chen-Yen; Lin, Yu-Chun; Lee, Bao-Hong; Shi, Yeu-Ching; Tai, Chen-Jei

    2016-01-01

    Chemotherapy, a major approach was used in carcinoma treatment, always involves the development of drug resistance as well as side-effects that affect the quality of patients' lives. An association between epithelial-mesenchymal transition (EMT) and chemotherapy resistance was established recently. We demonstrate in this paper that the aqueous extract of Paris polyphylla (AEPP)-a traditional Chinese medicine-can be used in various cancer types for suppression of carcinogenesis. We evaluated the suppressions of EMT and mitochondrial activity by AEPP treatment in a high-glucose (HG) induced-human ovarian carcinoma cell line (OVCAR-3 cells). The mitochondrial morphology was investigated using MitoTracker Deep Red FM staining. Our results indicated that AEPP reduced the viability of OVCAR-3 cells considerably through induction of apoptosis. However, this inhibitory potential of AEPP was attenuated by HG induction in OVCAR-3 cells. The levels of estrogen-related receptor (ERR)-alpha activator and peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha were elevated by HG induction, but were suppressed by AEPP treatment. Down-regulations of cell survival and EMT were oberved in OVCAR-3 cells through suppression of PGC-1alpha by AEPP treatment. These results were confirmed through PGC-1alpha knockdown and overexpression in OVCAR-3 cells. Thus, AEPP can be beneficial for treating ovarian cancer and has potential for development of an integrative cancer therapy against ovarian cancer proliferation, metastasis, and migration. PMID:27271583

  5. Inhibition of in vitro prostaglandin and leukotriene biosyntheses by cinnamoyl-beta-phenethylamine and N-acyldopamine derivatives.

    PubMed

    Tseng, C F; Iwakami, S; Mikajiri, A; Shibuya, M; Hanaoka, F; Ebizuka, Y; Padmawinata, K; Sankawa, U

    1992-02-01

    N-trans- and N-cis-Feruloyltyramines were isolated as the inhibitors of in vitro prostaglandin (PG) synthesis from an Indonesian medicinal plant, Ipomoea aquatica (Convolvulaceae). In order to clarify structure activity relationships, cinnamoyl-beta-phenethylamines with possible combinations of naturally occurring cinnamic acids and beta-phenethylamines were synthesized and tested for their inhibitory activities against PG synthetase and arachidonate 5-lipoxygenase. The compounds containing catechol groups such as N-caffeoyl-beta-phenethylamine (CaP) showed higher inhibitory effects on PG synthetase. The catechol group was found to be essential for the inhibition of arachidonate 5-lipoxygenase. The investigation of concentration dependent effects on PG biosynthesis revealed that CaP enhanced PG biosynthesis at a lower concentration range, whereas it inhibited the reaction at a higher concentration. The effects of CaP on each reaction step were investigated with purified PG endoperoxide synthase and microsomal PG synthetase. CaP inhibited the cyclooxygenase reaction, while it enhanced the hydroperoxidase reaction. N-Acyldopamines which contain catechol and lipophylic group were synthesized from dopamine and fatty acids to test their inhibitory effects on arachidonate 5-lipoxygenase. N-Linoleoyldopamine was the most active compound and its IC50 value was 2.3 nM in our assay system, in which an IC50 value of AA 861, a specific inhibitor of 5-lipoxygenase, was 8 nM. PMID:1606635

  6. Identification of hop polyphenolic components which inhibit prostaglandin E2 production by gingival epithelial cells stimulated with periodontal pathogen.

    PubMed

    Inaba, Hiroaki; Tagashira, Motoyuki; Honma, Daiki; Kanda, Tomomasa; Kou, Yurong; Ohtake, Yasuyuki; Amano, Atsuo

    2008-03-01

    Chronic marginal periodontitis is a destructive inflammatory disease caused by an imbalance between bacterial virulence and host defense ability, resulting in eventual tooth exfoliation. Porphyromonas gingivalis, a major periodontal pathogen, triggers a series of cellular inflammatory responses including the production of prostaglandin E2 (PGE2), which causes periodontal destruction; thus, anti-inflammatory reagents are considered beneficial for periodontal therapy. In the present study, we examined whether hop- and apple-derived polyphenols (HBP and ACT, respectively) inhibit PGE2 production by human gingival epithelial (HGE) cells stimulated with P. gingivalis components. HGE cells were stimulated with P. gingivalis membrane vesicles, and the effects of HBP, ACT and epigallocatechin gallate (EGCg) on PGE2 production by HGE cells were evaluated using an enzyme-linked immunosorbent assay. HBP and EGCg significantly inhibited PGE2 production, whereas ACT did not. By further fractionation steps of HBP to identify the effective components, 3 components of HBP, 2-[(2-methylpropanoyl)-phloroglucinol]1-O-beta-D-glucopyranoside (MPPG), quercetin 3-O-beta-D-glucopyranoside (isoquercitrin), and kaempferol 3-O-beta-glucopyranoside (astragalin), were found to be elements which significantly inhibited cellular PGE2 production. These results suggest that HBP is a potent inhibitor of cellular PGE2 production induced by P. gingivalis, and HBP may be useful for the prevention and attenuation of periodontitis. PMID:18310924

  7. Celastrol inhibits prostaglandin E2-induced proliferation and osteogenic differentiation of fibroblasts isolated from ankylosing spondylitis hip tissues in vitro

    PubMed Central

    Zou, Yu-Cong; Yang, Xian-Wen; Yuan, Shi-Guo; Zhang, Pei; Li, Yi-Kai

    2016-01-01

    Background Heterotopic ossification on the enthesis, which develops after subsequent inflammation, is one of the most distinctive features in ankylosing spondylitis (AS). Prostaglandin E2 (PGE-2) serves as a key mediator of inflammation and bone remodeling in AS. Celastrol, a well-known Chinese medicinal herb isolated from Tripterygium wilfordii, is widely used in treating inflammatory diseases, including AS. It has been proven that it can inhibit lipopolysac-charide-induced expression of various inflammation mediators, such as PGE-2. However, the mechanism by which celastrol inhibits inflammation-induced bone forming in AS is unclear. Objective To investigate whether celastrol could inhibit isolated AS fibroblast osteogenesis induced by PGE-2. Methods Hip synovial tissues were obtained from six AS patients undergoing total hip replacement in our hospital. Fibroblasts were isolated, primarily cultured, and then treated with PGE-2 for osteogenic induction. Different doses of celastrol and indometacin were added to observe their effects on osteogenic differentiation. Cell proliferation, osteogenic markers, alizarin red staining as well as the activity of alkaline phosphatase were examined in our study. Results Celastrol significantly inhibits cell proliferation of isolated AS fibroblasts and in vitro osteogenic differentiation compared with control groups in a time- and dose-dependent manner. Conclusion Our results demonstrated that celastrol could inhibit isolated AS fibroblast proliferation and in vitro osteogenic differentiation. The interaction of PI3K/AKT signaling and Wnt protein may be involved in the process. Further studies should be performed in vivo and animal models to identify the potential effect of celastrol on the bone metabolism of AS patients. PMID:27022241

  8. Inhibition of hematopoietic prostaglandin D2 Synthase (H-PGDS) by an alkaloid extract from Combretum molle

    PubMed Central

    2014-01-01

    Background Hematopoietic prostaglandin D2 synthase (H-PGDS, GST Sigma) is a member of the glutathione S-transferase super family of enzymes that catalyses the conjugation of electrophilic substances with reduced glutathione. The enzyme catalyses the conversion of PGH2 to PGD2 which mediates inflammatory responses. The inhibition of H-PGDS is of importance in alleviating damage to tissues due to unwarranted synthesis of PGD2. Combretum molle has been used in African ethno medicinal practices and has been shown to reduce fever and pain. The effect of C. molle alkaloid extract on H-PGDS was thus, investigated. Methods H-PGDS was expressed in Escherichia coli XL1-Blue cells and purified using nickel immobilized metal affinity chromatography. The effect of C. molle alkaloid extract on H-PGDS activity was determined with 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. The effect of C. molle alkaloid extract with time on H-PGDS was determined. The mechanism of inhibition was then investigated using CDNB and glutathione (GSH) as substrates. Results A specific activity of 24 μmol/mg/min was obtained after H-PGDS had been purified. The alkaloid extract exhibited a 70% inhibition on H-PGDS with an IC50 of 13.7 μg/ml. C. molle alkaloid extract showed an uncompetitive inhibition of H-PGDS with Ki = 41 μg/ml towards GSH, and non-competitive inhibition towards CDNB with Ki = 7.7 μg/ml and Ki′ = 9.2 μg/ml. Conclusion The data shows that C. molle alkaloid extract is a potent inhibitor of H-PGDS. This study thus supports the traditional use of the plant for inflammation. PMID:24996417

  9. Normal Human Lung Epithelial Cells Inhibit Transforming Growth Factor-β Induced Myofibroblast Differentiation via Prostaglandin E2

    PubMed Central

    Epa, Amali P.; Thatcher, Thomas H.; Pollock, Stephen J.; Wahl, Lindsay A.; Lyda, Elizabeth; Kottmann, R. M.; Phipps, Richard P.; Sime, Patricia J.

    2015-01-01

    Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease with very few effective treatments. The key effector cells in fibrosis are believed to be fibroblasts, which differentiate to a contractile myofibroblast phenotype with enhanced capacity to proliferate and produce extracellular matrix. The role of the lung epithelium in fibrosis is unclear. While there is evidence that the epithelium is disrupted in IPF, it is not known whether this is a cause or a result of the fibroblast pathology. We hypothesized that healthy epithelial cells are required to maintain normal lung homeostasis and can inhibit the activation and differentiation of lung fibroblasts to the myofibroblast phenotype. To investigate this hypothesis, we employed a novel co-culture model with primary human lung epithelial cells and fibroblasts to investigate whether epithelial cells inhibit myofibroblast differentiation. Measurements and Main Results In the presence of transforming growth factor (TGF)-β, fibroblasts co-cultured with epithelial cells expressed significantly less α-smooth muscle actin and collagen and showed marked reduction in cell migration, collagen gel contraction, and cell proliferation compared to fibroblasts grown without epithelial cells. Epithelial cells from non-matching tissue origins were capable of inhibiting TGF-β induced myofibroblast differentiation in lung, keloid and Graves’ orbital fibroblasts. TGF-β promoted production of prostaglandin (PG) E2 in lung epithelial cells, and a PGE2 neutralizing antibody blocked the protective effect of epithelial cell co-culture. Conclusions We provide the first direct experimental evidence that lung epithelial cells inhibit TGF-β induced myofibroblast differentiation and pro-fibrotic phenotypes in fibroblasts. This effect is not restricted by tissue origin, and is mediated, at least in part, by PGE2. Our data support the hypothesis that the epithelium plays a crucial role in maintaining lung homeostasis

  10. Effect of inhibition of prostaglandin synthesis on breathing movements and pulmonary blood flow in fetal sheep.

    PubMed

    Savich, R D; Guerra, F A; Lee, C C; Kitterman, J A

    1995-02-01

    During transition from fetal to extrauterine life, respiration increases in incidence and magnitude as pulmonary blood flow dramatically increases. To determine whether alterations in pulmonary blood flow in utero are directly related to alterations in fetal breathing movements (FBM), we studied six chronically instrumented fetal sheep late in gestation to assess the effects of continuous FBM caused by a 4-h infusion of meclofenamate, a prostaglandin synthase inhibitor, on mean pulmonary blood flow to the fetus. We found a striking increase in FBM from 46 +/- 15% (SD) of the time during control to > 85% of the time by 1 h (P < 0.001), with the fetuses exhibiting continuous FBM by the last 1 h of infusion. The mean pulmonary blood flow also increased significantly during the first 90 min of the infusion as the incidences of FBM were increasing (26 +/- 14 and 56 +/- 23 ml.min-1.kg-1 for control and infusion, respectively; P < 0.01). Despite the simultaneous initial increase in FBM and mean pulmonary blood flow, the increase in left pulmonary artery blood flow was not sustained and decreased back to baseline by 2 h, even though the incidence of FBM continued to increase at this time. During the infusion, the mean pulmonary blood flow was not different between the presence or absence of FBM. There were no changes in fetal heart rate or pulmonary or systemic blood pressures during the infusion nor in arterial pH or blood gas tensions. We conclude that this increase in mean pulmonary blood flow in utero was not solely related to the increase in breathing movements. PMID:7759422

  11. Prostaglandins of the E-series inhibit connective tissue proliferation in the liver wound of the rat.

    PubMed

    Arend, A; Aunapuu, M; Masso, R; Selstam, G

    2005-03-01

    The present study was undertaken to relate wound healing of an internal organ to prostaglandins of the E and F series. A small liver wound was induced by a galvanic cauter via the abdominal route under general anesthesia and prostaglandin E1, E2 and F2alpha were injected twice daily at a dose of 250 microg/kg. Proliferation of the connective tissue in the liver wound was estimated morphometrically 6 days after liver wound infliction. Levels of prostaglandins E2 and F2alpha were measured in the liver wound as well as in normal liver tissue from adjacent lobes using radioimmunoassay. The results show that exogenous prostaglandins of the E-series suppress connective tissue proliferation. Three minutes after the last prostaglandin E2 injection, high prostaglandin concentrations were measured both in the liver wound and in the liver tissue of the adjacent lobe. Prostaglandin F2alpha injections had no effect on wound healing. We believe that the rat thermic liver wound model can be used for different studies on wound healing mechanisms and that prostaglandins of the E-series are involved in wound healing in the specific time period studied. PMID:15835401

  12. Anti-inflammatory activity of Nerium indicum by inhibition of prostaglandin E2 in murine splenic lymphocytes

    PubMed Central

    Dey, Priyankar; Chaudhuri, Tapas Kumar

    2015-01-01

    Objective: Nerium indicum Mill (syn. N. oleander L. and N. odorum Aiton; family: Apocynaceae) is a medicinal plant, used in the treatment of diverse ailments including various chronic inflammatory diseases in traditional medicine. We have previously demonstrated the immunomodulatory activity of a bioactive fraction of Nerium indicum leaf (NILE) by studying up-regulation of interleukin-2 (IL-2), IL-10, interferon-gamma and down regulation of IL-4, tumor necrosis factor-alpha (TNF-α), nitric oxide, cyclooxygenase-1 (COX-1) and COX-2 activities. Therefore, this study aimed to confirm the anti-inflammatory activity of NILE by inhibition of prostaglandin E2 (PGE2) activity in murine splenic lymphocytes in vitro. Materials and Methods: Murine lymphocytes were isolated from spleen and stimulated with 5 ΅g/mL concanavalin A in RPMI-1640, supplemented with 50 U/mL penicillin, 50 U/mL streptomycin, 50 U/mL nystatin and 10% fetal bovine serum. Different concentrations (0–80 μg/mL) of NILE were added and the cells were cultured for 48 h. The culture supernatants were thereafter collected by centrifugation and assayed for expression of PGE2 level. The data were analyzed statistically. Results: The results demonstrated a 2.26-fold inhibition of PGE2 level at 80 μg/mL of NILE. Half maximum inhibitory concentration (IC50) was calculated to be 44.95 ± 0.45 ΅g/mL. Linear correlation analysis of the dose-dependent PGE2 inhibition with other pro- and anti-inflammatory mediators demonstrated high inter-correlation between the parameters. Conclusions: Thus, the present study remains in accordance with our previous report and confirms the anti-inflammatory claim of N. indicum, mentioned in the traditional medicine. PMID:26288481

  13. Indomethacin inhibits eosinophil migration to prostaglandin D2: therapeutic potential of CRTH2 desensitization for eosinophilic pustular folliculitis

    PubMed Central

    Kataoka, Naoko; Satoh, Takahiro; Hirai, Aiko; Saeki, Kazumi; Yokozeki, Hiroo

    2013-01-01

    Summary Indomethacin is a cyclo-oxygenase inhibitor, and shows therapeutic potential for various eosinophilic skin diseases, particularly eosinophilic pustular folliculitis. One of the unique characteristics of indomethacin is that, unlike other non-steroidal anti-inflammatory drugs, it is a potent agonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2), a receptor for prostaglandin D2 (PGD2). This study investigated the pharmacological actions of indomethacin on eosinophil migration to clarify the actual mechanisms underlying the therapeutic effects of indomethacin on eosinophilic pustular folliculitis. Eosinophils exhibited chemokinetic and chemotactic responses to both PGD2 and indomethacin through CRTH2 receptors. Pre-treatment of eosinophils with indomethacin greatly inhibited eosinophil migration to PGD2 and, to a much lesser extent, to eotaxin (CCL11); these effects could be mediated by homologous and heterologous desensitization of eosinophil CRTH2 and CCR3, respectively, by agonistic effects of indomethacin on CRTH2. Indomethacin also cancelled a priming effect of Δ12-PGJ2, a plasma metabolite of PGD2, on eosinophil chemotaxis to eotaxin. Indomethacin down-modulated cell surface expression of both CRTH2 and CCR3. Hair follicle epithelium and epidermal keratinocytes around eosinophilic pustules together with the eccrine apparatus of palmoplantar lesions of eosinophilic pustular folliculitis were immunohistochemically positive for lipocalin-type PGD synthase. Indomethacin may exert therapeutic effects against eosinophilic skin diseases in which PGD2-CRTH2 signals play major roles by reducing eosinophil responses to PGD2. PMID:23582181

  14. Cytokines inhibit sexual behavior in female rats: II. Prostaglandins mediate the suppressive effects of interleukin-1beta.

    PubMed

    Avitsur, R; Weidenfeld, J; Yirmiya, R

    1999-03-01

    The proinflammatory cytokine interleukin-1 (IL-1) induces several behavioral alterations that are characteristic of illness, such as anorexia and reduced locomotor and social activity. We have recently demonstrated that IL-1 inhibits sexual activity, motivation and attractivity in female, but not in male rats following either central or peripheral administration. In the present study we examined the involvement of prostaglandin (PG) synthesis in mediating IL-1-induced suppression of female sexual behavior. Administration of the cyclooxygenase blockers indomethacin or ibuprofen completely prevented IL-1-induced suppression of female sexual behavior, including the reduction in proceptive behavior, the lordosis response to a male's mounts, and the preference for a sexually active partner. In a subsequent study, ex-vivo release of hypothalamic PGE2 and the secretion of corticosterone (CS) were measured in males and estrous females following IL-1 administration. At the same time and dose of IL-1 administration that significantly reduced sexual behavior in female but not male rats, IL-1 produced a significant increase in PGE2 release in female, but not in male rats. In contrast, IL-1 induced a significant elevation of serum CS levels in males but not in females. These findings suggest that PG synthesis is involved in mediating the effects of IL-1 on female sexual behavior. Furthermore, differential secretion of PGs and CS may underlie the gender difference in the effects of IL-1 on sexual behavior. PMID:10371676

  15. Co-oxidation of 2-bromohydroquinone by renal prostaglandin synthase. Modulation of prostaglandin synthesis by 2-bromohydroquinone and glutathione.

    PubMed

    Lau, S S; Monks, T J

    1987-01-01

    Homogenates from rat renal papillae, a rich source of the prostaglandin (PG) H synthase system (PHS), metabolized [14C]2-bromohydroquinone, in the presence of arachidonic acid, to products which are covalently bound to protein. The co-oxidation of 2-bromohydroquinone caused a concentration-dependent stimulation in 6-keto-PGF1 alpha, thromboxane B2, PGF2 alpha, PGE2, and PGD2 formation. Glutathione (1 mM) caused a decrease in prostaglandin formation and inhibited the arachidonic acid-supported covalent binding of [14C]2-bromohydroquinone with the concomitant formation of [14C]2-bromohydroquinone-glutathione conjugates, oxidized glutathione, and an increase in the recovery of [14C]2-bromohydroquinone. NADPH also inhibited [14C]2-bromohydroquinone covalent binding, probably by reduction of the semiquinone radical back to the hydroquinone. Indomethacin and aspirin, inhibitors of the cyclooxygenase component of PHS, and propylthiouracil and methimazole, inhibitors of the hydroperoxidase component of PHS, inhibited the arachidonic acid-supported covalent binding of [14C]2-bromohydroquinone by 94%, 52%, 78%, and 79% respectively. These data suggest that 1) renal PHS may play a role in activating the nephrotoxin, 2-bromohydroquinone, and that 2) xenobiotic metabolism and its subsequent effects on glutathione levels can modulate renal prostaglandin synthesis. PMID:2893705

  16. The cyclopentenone prostaglandin 15d-PGJ2 inhibits the NLRP1 and NLRP3 inflammasomes.

    PubMed

    Maier, Nolan K; Leppla, Stephen H; Moayeri, Mahtab

    2015-03-15

    Inflammasomes are cytosolic protein complexes that respond to diverse danger signals by activating caspase-1. The sensor components of the inflammasome, often proteins of the nucleotide-binding oligomerization domain-like receptor (NLR) family, detect stress, danger stimuli, and pathogen-associated molecular patterns. We report that the eicosanoid 15-deoxy-Δ(12,14)-PGJ2 (15d-PGJ2) and related cyclopentenone PGs inhibit caspase-1 activation by the NLR family leucine-rich repeat protein (NLRP)1 and NLRP3 inflammasomes. This inhibition was independent of the well-characterized role of 15d-PGJ2 as a peroxisome proliferator receptor-γ agonist, its activation of NF erythroid 2-related factor 2, or its anti-inflammatory function as an inhibitor of NF-κB. Instead, 15d-PGJ2 prevents the autoproteolytic activation of caspase-1 and the maturation of IL-1β through induction of a cellular state inhibitory to caspase-1 proteolytic function. The eicosanoid does not directly modify or inactivate the caspase-1 enzyme. Rather, inhibition is dependent on de novo protein synthesis. In a mouse peritonitis model of gout, using monosodium urate crystals to activate NLRP3, 15d-PGJ2 caused a significant inhibition of cell recruitment and associated IL-1β release. Furthermore, in a murine anthrax infection model, 15d-PGJ2 reversed anthrax lethal toxin-mediated NLRP1-dependent resistance. The findings reported in this study suggest a novel mechanism for the anti-inflammatory properties of the cyclopentenone PGs through inhibition of caspase-1 and the inflammasome. PMID:25681332

  17. Enhancement by clofazimine and inhibition by dapsone of production of prostaglandin E2 by human polymorphonuclear leukocytes in vitro.

    PubMed Central

    Anderson, R

    1985-01-01

    The effects of the antileprosy agents clofazimine and dapsone (1 to 10 micrograms/ml) on the spontaneous and stimulated release of prostaglandin E2 (PG E2) by human polymorphonuclear leukocytes (PMNL) in vitro have been investigated. PMNL were obtained from normal adult volunteers and three patients with leprosy (two borderline lepromatous and one subpolar lepromatous leprosy). The synthetic chemotactic tripeptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) at a concentration of 10(-7) M was used as the stimulant of PG E2 synthesis. None of the test agents at the concentrations used inhibited the binding of radiolabeled FMLP to PMNL. However, dapsone at 5 and 10 micrograms/ml inhibited the spontaneous and FMLP-induced release of PG E2 by PMNL. Clofazimine, on the other hand, significantly increased both the spontaneous and the FMLP-induced synthesis of PG E2 by PMNL. The enhancing effects of clofazimine on FMLP-mediated synthesis of PG E2 were particularly striking and were observed at concentrations of 1 to 10 micrograms of the drug per ml. Measurements of PMNL spontaneous and FMLP-induced synthesis of PG E2 in the presence of both clofazimine and dapsone (5 micrograms/ml) indicated that the two drugs are mutually antagonistic. PMNL from both normal control subjects and patients with leprosy were equally sensitive to these effects of clofazimine and dapsone. The immunostimulatory and immunosuppressive properties of dapsone and clofazimine, respectively, may be related to the opposite effects of these agents on PG E2 synthesis in human leukocytes. PMID:3857019

  18. Effects of prostaglandins and COX-inhibiting drugs on skeletal muscle adaptations to exercise

    PubMed Central

    Liu, Sophia Z.

    2013-01-01

    It has been ∼40 yr since the discovery that PGs are produced by exercising skeletal muscle and since the discovery that inhibition of PG synthesis is the mechanism of action of what are now known as cyclooxygenase (COX)-inhibiting drugs. Since that time, it has been established that PGs are made during and after aerobic and resistance exercise and have a potent paracrine and autocrine effect on muscle metabolism. Consequently, it has also been determined that orally consumed doses of COX inhibitors can profoundly influence muscle PG synthesis, muscle protein metabolism, and numerous other cellular processes that regulate muscle adaptations to exercise loading. Although data from acute human exercise studies, as well as animal and cell-culture data, would predict that regular consumption of a COX inhibitor during exercise training would dampen the typical muscle adaptations, the chronic data do not support this conjecture. From the studies in young and older individuals, lasting from 1.5 to 4 mo, no interfering effects of COX inhibitors on muscle adaptations to resistance-exercise training have been noted. In fact, in older individuals, a substantial enhancement of muscle mass and strength has been observed. The collective findings of the PG/COX-pathway regulation of skeletal muscle responses and adaptations to exercise are compelling. Considering the discoveries in other areas of COX regulation of health and disease, there is certainly an interesting future of investigation in this re-emerging area, especially as it pertains to older individuals and the condition of sarcopenia, as well as exercise training and performance of individuals of all ages. PMID:23539318

  19. A novel role for 3, 4-dichloropropionanilide (DCPA) in the inhibition of prostate cancer cell migration, proliferation, and hypoxia-inducible factor 1alpha expression

    PubMed Central

    Jiang, Bing-Hua; Liu, Ling-Zhi; Schafer, Rosana; Flynn, Daniel C; Barnett, John B

    2006-01-01

    Background The amide class compound, 3, 4-dichloropropionanilide (DCPA) is known to affect multiple signaling pathways in lymphocyte and macrophage including the inhibition of NF-κB ability. However, little is known about the effect of DCPA in cancer cells. Hypoxia-inducible factor 1 (HIF-1) regulates the expression of many genes including vascular endothelial growth factor (VEGF), heme oxygenase 1, inducible nitric oxide synthase, aldolase, enolase, and lactate dehydrogenase A. HIF-1 expression is associated with tumorigenesis and angiogenesis. Methods We used Transwell assay to study cell migration, and used immunoblotting to study specific protein expression in the cells. Results In this report, we demonstrate that DCPA inhibited the migration and proliferation of DU145 and PC-3 prostate cancer cells induced by serum, insulin, and insulin-like growth factor I (IGF-I). We found that DCPA inhibited HIF-1 expression in a subunit-specific manner in these cancer cell lines induced by serum and growth factors, and decreased HIF-1α expression by affecting its protein stability. Conclusion DCPA can inhibit prostate cancer cell migration, proliferation, and HIF-1α expression, suggesting that DCPA could be potentially used for therapeutic purpose for prostate cancer in the future. PMID:16884534

  20. Endogenous prostaglandin E2 mediates inhibition of rat thick ascending limb Cl reabsorption in chronic hypercalcemia.

    PubMed Central

    Peterson, L N; McKay, A J; Borzecki, J S

    1993-01-01

    The hypothesis that endogenous PGE2 mediates defective thick ascending limb (TAL) Cl reabsorption (percent delivered load: FRCl%) in rats with vitamin D-induced chronic hypercalcemia (HC) was tested by measuring FRCl% in loop segments microperfused in vivo in HC and control rats treated acutely with indomethacin (Indo) or its vehicle, and obtaining the corresponding outer medullary [PGE2]. Microperfusion conditions were developed in which FRCl% was exclusively furosemide sensitive. To determine the cellular mechanism, tubules were perfused acutely with forskolin (FSK), cAMP, or the protein kinase C inhibitor staurosporine (SSP). Outer medullary [PGE2] in HC rats was 9 to 10 times greater than control and could be normalized by Indo. FRCl% was 20% lower in HC rats infused with vehicle, and Indo, FSK, and cAMP returned FRCl% to normal despite sustained HC. Indo or FSK had no effect on FRCl% in control rats and Indo did not prevent inhibition of FRCl% by luminal PGE2 (1 microM). Luminal SSP (10(-7), 10(-8) M) in HC did not return FRCl% to control values. We conclude that impaired TAL FRCl% in HC occurs at a pre-cAMP site and is due to endogenous PGE2 and not to HC. Images PMID:8390479

  1. Inhibition of Casein Kinase 1 Alpha Prevents Acquired Drug Resistance to Erlotinib in EGFR-Mutant Non-Small Cell Lung Cancer.

    PubMed

    Lantermann, Alexandra B; Chen, Dongshu; McCutcheon, Kaitlin; Hoffman, Greg; Frias, Elizabeth; Ruddy, David; Rakiec, Daniel; Korn, Joshua; McAllister, Gregory; Stegmeier, Frank; Meyer, Matthew J; Sharma, Sreenath V

    2015-11-15

    Patients with lung tumors harboring activating mutations in the EGF receptor (EGFR) show good initial treatment responses to the EGFR tyrosine kinase inhibitors (TKI) erlotinib or gefitinib. However, acquired resistance invariably develops. Applying a focused shRNA screening approach to identify genes whose knockdown can prevent and/or overcome acquired resistance to erlotinib in several EGFR-mutant non-small cell lung cancer (NSCLC) cell lines, we identified casein kinase 1 α (CSNK1A1, CK1α). We found that CK1α suppression inhibits the NF-κB prosurvival signaling pathway. Furthermore, downregulation of NF-κB signaling by approaches independent of CK1α knockdown can also attenuate acquired erlotinib resistance, supporting a role for activated NF-κB signaling in conferring acquired drug resistance. Importantly, CK1α suppression prevented erlotinib resistance in an HCC827 xenograft model in vivo. Our findings suggest that patients with EGFR-mutant NSCLC might benefit from a combination of EGFR TKIs and CK1α inhibition to prevent acquired drug resistance and to prolong disease-free survival. PMID:26490646

  2. Inhibition of nitric oxide and prostaglandins, but not endothelial-derived hyperpolarizing factors, reduces blood flow and aerobic energy turnover in the exercising human leg.

    PubMed

    Mortensen, Stefan P; González-Alonso, José; Damsgaard, Rasmus; Saltin, Bengt; Hellsten, Ylva

    2007-06-01

    Prostaglandins, nitric oxide (NO) and endothelial-derived hyperpolarizing factors (EDHFs) are substances that have been proposed to be involved in the regulation of skeletal muscle blood flow during physical activity. We measured haemodynamics, plasma ATP at rest and during one-legged knee-extensor exercise (19 +/- 1 W) in nine healthy subjects with and without intra-arterial infusion of indomethacin (Indo; 621 +/- 17 microg min(-1)), Indo + N(G)-monomethyl-L-arginine (L-NMMA; 12.4 +/- 0.3 mg min(-1)) (double blockade) and Indo + L-NMMA + tetraethylammonium chloride (TEA; 12.4 +/- 0.3 mg min(-1)) (triple blockade). Double and triple blockade lowered leg blood flow (LBF) at rest (P<0.05), while it remained unchanged with Indo. During exercise, LBF and vascular conductance were 2.54 +/- 0.10 l min(-1) and 25 +/- 1 mmHg, respectively, in control and they were lower with double (33 +/- 3 and 36 +/- 4%, respectively) and triple (26 +/- 4 and 28 +/- 3%, respectively) blockade (P<0.05), while there was no difference with Indo. The lower LBF and vascular conductance with double and triple blockade occurred in parallel with a lower O(2) delivery, cardiac output, heart rate and plasma [noradrenaline] (P<0.05), while blood pressure remained unchanged and O(2) extraction and femoral venous plasma [ATP] increased. Despite the increased O(2) extraction, leg was 13 and 17% (triple and double blockade, respectively) lower than control in parallel to a lower femoral venous temperature and lactate release (P<0.05). These results suggest that NO and prostaglandins play important roles in skeletal muscle blood flow regulation during moderate intensity exercise and that EDHFs do not compensate for the impaired formation of NO and prostaglandins. Moreover, inhibition of NO and prostaglandin formation is associated with a lower aerobic energy turnover and increased concentration of vasoactive ATP in plasma. PMID:17347273

  3. Augmented skeletal muscle hyperaemia during hypoxic exercise in humans is blunted by combined inhibition of nitric oxide and vasodilating prostaglandins.

    PubMed

    Crecelius, Anne R; Kirby, Brett S; Voyles, Wyatt F; Dinenno, Frank A

    2011-07-15

    Exercise hyperaemia in hypoxia is augmented relative to the same level of exercise in normoxia. At moderate exercise intensities, the mechanism(s) underlying this augmented response are currently unclear. We tested the hypothesis that endothelium-derived nitric oxide (NO) and vasodilating prostaglandins (PGs) contribute to the augmented muscle blood flow during hypoxic exercise relative to normoxia. In 10 young healthy adults, we measured forearm blood flow (FBF; Doppler ultrasound) and calculated the vascular conductance (FVC) responses during 5 min of rhythmic handgrip exercise at 20% maximal voluntary contraction in normoxia (NormEx) and isocapnic hypoxia (HypEx; O2 saturation ∼85%) before and after local intra-brachial combined blockade of NO synthase (NOS; via N(G)-monomethyl-L-arginine: L-NMMA) and cyclooxygenase (COX; via ketorolac). All trials were performed during local α- and β-adrenoceptor blockade to eliminate sympathoadrenal influences on vascular tone and thus isolate local vasodilatation. Arterial and deep venous blood gases were measured and oxygen consumption (VO2) was calculated. In control (saline) conditions, FBF after 5 min of exercise in hypoxia was greater than in normoxia (345 ± 21 ml min(−1) vs. 297 ± 18 ml min(−1); P < 0.05). After NO–PG block, the compensatory increase in FBF during hypoxic exercise was blunted ∼50% and thus was reduced compared with control hypoxic exercise (312 ± 19 ml min(−1); P < 0.05), but this was not the case in normoxia (289 ± 15 ml min(−1); P = 0.33). The lower FBF during hypoxic exercise was associated with a compensatory increase in O2 extraction, and thus VO2 was maintained at normal control levels (P = 0.64–0.99). We conclude that under the experimental conditions employed, NO and PGs have little role in normoxic exercise hyperaemia whereas combined NO–PG inhibition reduces hypoxic exercise hyperaemia and abolishes hypoxic vasodilatation at rest. Additionally, VO2 of the tissue was

  4. Gastroprotective Activities of Sennoside A and Sennoside B via the Up-Regulation of Prostaglandin E2 and the Inhibition of H+/K+-ATPase

    PubMed Central

    Hwang, In Young; Jeong, Choon Sik

    2015-01-01

    Sennoside A (erythro) and sennoside B (threo) are dianthrone glycosides and diastereomers. We investigated their abilities to prevent the gastric lesions associated with diseases, such as, gastritis and gastric ulcer. To elucidate their gastroprotective effects, the inhibitions of HCl•EtOH-induced gastritis and indomethacin-induced gastric ulcers were assessed in rats. It was observed that both sennoside A and sennoside B increased prostaglandin E2 (PGE2) levels and inhibited H+/K+-ATPase (proton pump). In a rat model, both compounds reduced gastric juice, total acidity and increased pH, indicating that proton pump inhibition reduces gastric acid secretion. Furthermore, sennoside A and B increased PGE2 in a concentration-dependent manner. In a gastric emptying and intestinal transporting rate experiment, both sennoside A and sennoside B accelerated motility. Our results thus suggest that sennoside A and sennoside B possess significant gastroprotective activities and they might be useful for the treatment of gastric disease. PMID:26336586

  5. Type 5 17β-Hydroxysteroid Dehydrogenase/Prostaglandin F Synthase (AKR1C3): Role In Breast Cancer and Inhibition by Nonsteroidal Antiinflammatory Drug Analogs

    PubMed Central

    Byrns, Michael C.; Penning, Trevor M.

    2011-01-01

    Aldo-keto reductase (AKR) 1C3 catalyzes the NADPH dependent reduction of Δ4-androstene-3,17-dione to yield testosterone, reduction of estrone to yield 17β-estradiol and reduction of progesterone to yield 20α-hydroxyprogesterone. In addition, it functions as a prostaglandin (PG) F synthase and reduces PGH2 to PGF2α and PGD2 to 11β-PGF2. Immunohistochemistry showed that AKR1C3 is over expressed in invasive ductal carcinoma of the breast. Retroviral expression of AKR1C3 in MCF-7 breast carcinoma cells shows that each of the assigned reactions occur in a breast cell microenvironment. Steroid and prostaglandin conversions were monitored by radiochromatography. Prostaglandin conversion was validated by a second method using HPLC coupled to APCI-MRM/MS. The combined effect of the AKR1C3 catalyzed 17- and 20-ketosteroid reductions will be to increase the 17β-estradiol : progesterone ratio in the breast. In addition, formation of PGF2 epimers would activate F prostanoid receptors and deprive PPARγ of its putative anti-proliferative PGJ2 ligands. Thus, AKR1C3 is a source of proliferative signals and a potential therapeutic target for hormone dependent and independent breast cancer. Two strategies for AKR1C3 inhibition based on non-steroidal anti-inflammatory drugs were developed. The first strategy uses the Ullmann coupling reaction to generate N-phenylanthranilate derivatives that inhibit AKR1C enzymes without affecting PGH2 synthase (PGHS) 1 or PGHS-2. The second strategy exploits the selective inhibition of AKR1C3 by indomethacin, which did not inhibit highly related AKR1C1 or AKR1C2. Using known structure activity relationships for the inhibition of PGHS-1 and PGHS-2 by indole acetic acids we obtained N-(4-chlorobenzoyl)-melatonin as a specific AKR1C3 inhibitor (KI = 6.0 μM) that does not inhibit PGHS-1, PGHS-2, AKR1C1, or AKR1C2. Both strategies are informed by crystal structures of ternary AKR1C3•NADP+•NSAID complexes. The identification of NSAID analogs as

  6. The number of tartrate-resistant acid phosphatase-positive osteoclasts on neonatal mouse parietal bones is decreased when prostaglandin synthesis is inhibited and increased in response to prostaglandin E2, parathyroid hormone, and 1,25 dihydroxyvitamin D3.

    PubMed

    Marshall, M J; Holt, I; Davie, M W

    1995-03-01

    The culture of parietal bones from 4-day old mice in indomethacin (Ind) for 1 day caused a large reduction in the number of tartrate-resistant acid phosphatase positive osteoclasts (TRAP + OC) relative to both control bones and to freshly isolated bones. This reduction did not occur if prostaglandin E2 (PGE2) was present. When 5-bromo-2'-deoxyuridine (BDU) was injected into 4-day old mice, newly formed TRAP + OC nuclei became labeled 1 day later; these bones were then cultured with Ind for 1 day. TRAP + OC and newly labeled TRAP+OC nuclei were commensurately decreased in number. This suggests an active down-regulation rather than merely the inhibition of new TRAP+OC formation. Incubation of bones with Ind and either PGE2, parathyroid hormone, or 1,25 dihydroxyvitamin D3 for 6 hours following a 1-day preincubation in Ind, resulted in an increase in TRAP + OC compared with Ind alone. Using BDU labeling in vitro and in vivo, we show that this increase in number of TRAP+OC is not the result of cell proliferation, but rather differentiation of postmitotic precursors. PMID:7538445

  7. 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

  8. Inhibition of prostaglandin synthesis leads to a change in adherence of mouse osteoclasts from bone to periosteum.

    PubMed

    Marshall, M J; Holt, I; Davie, M W

    1996-09-01

    When mouse parietal bones were incubated for 1 day in medium containing indomethacin (Ind), the number of tartrate-resistant acid phosphatase-positive osteoclasts (TRAP+OC) counted on the bone surface was drastically reduced. This reduction did not occur with calcitonin or if the endocranial membrane (periosteum) was removed prior to incubation with Ind. The aim of this work was to determine the mechanism involved. TRAP+OC were found to be increased on the endocranial membrane adjacent to the resorbing surface after Ind treatment, compared with cultures supplemented with parathyroid hormone (PTH) or prostaglandin E2 (PGE2). However, this increase accounted for only half of those lost from the bone surface. TRAP negative osteoclasts were also seen on the membrane and, to a lesser extent, on the bone. Increased TRAP specific activity could be extracted from the endocranial membranes of bones incubated with Ind compared with PGE2 controls. When bones that had been exposed to Ind were then cultured for 1 day in PGE2, an increase in TRAP+OC occurred. This increase was blocked by the removal of the endocranial membrane prior to incubation with PGE2. We conclude that when prostaglandin production ceases, TRAP+OC become less adherent to bone and more adherent to the endocranial membrane. Stimulators of bone resorption appear to reverse this process. PMID:8694899

  9. Inhibition of Prostaglandin E2 Production by Anti-inflammatory Hypericum perforatum Extracts and Constituents in RAW264.7 Mouse Macrophage Cells

    PubMed Central

    Hammer, Kimberly D. P.; Hillwig, Matthew L.; Solco, Avery K. S.; Dixon, Philip M.; Delate, Kathleen; Murphy, Patricia A.; Wurtele, Eve S.; Birt, Diane F.

    2008-01-01

    Hypericum perforatum (Hp) is commonly known for its antiviral, antidepressant, and cytotoxic properties, but traditionally Hp was also used to treat inflammation. In this study, the anti-inflammatory activity and cytotoxicity of different Hp extractions and accessions and constituents present within Hp extracts were characterized. In contrast to the antiviral activity of Hp, the anti-inflammatory activity observed with all Hp extracts was light-independent. When pure constituents were tested, the flavonoids, amentoflavone, hyperforin, and light-activated pseudohypericin, displayed anti-inflammatory activity, albeit at concentrations generally higher than the amount present in the Hp extracts. Constituents that were present in the Hp extracts at concentrations that inhibited the production of prostaglandin E2 (PGE2) were pseudohypericin and hyperforin, suggesting that they are the primary anti-inflammatory constituents along with the flavonoids, and perhaps the interactions of these constituents and other unidentified compounds are important for the anti-inflammatory activity of the Hp extracts. PMID:17696442

  10. Inhibition of prostaglandin E(2) production by anti-inflammatory hypericum perforatum extracts and constituents in RAW264.7 Mouse Macrophage Cells.

    PubMed

    Hammer, Kimberly D P; Hillwig, Matthew L; Solco, Avery K S; Dixon, Philip M; Delate, Kathleen; Murphy, Patricia A; Wurtele, Eve S; Birt, Diane F

    2007-09-01

    Hypericum perforatum (Hp) is commonly known for its antiviral, antidepressant, and cytotoxic properties, but traditionally Hp was also used to treat inflammation. In this study, the anti-inflammatory activity and cytotoxicity of different Hp extractions and accessions and constituents present within Hp extracts were characterized. In contrast to the antiviral activity of Hp, the anti-inflammatory activity observed with all Hp extracts was light-independent. When pure constituents were tested, the flavonoids, amentoflavone, hyperforin, and light-activated pseudohypericin, displayed anti-inflammatory activity, albeit at concentrations generally higher than the amount present in the Hp extracts. Constituents that were present in the Hp extracts at concentrations that inhibited the production of prostaglandin E(2) (PGE(2)) were pseudohypericin and hyperforin, suggesting that they are the primary anti-inflammatory constituents along with the flavonoids, and perhaps the interactions of these constituents and other unidentified compounds are important for the anti-inflammatory activity of the Hp extracts. PMID:17696442

  11. 15-Deoxy-Δ12,14-prostaglandin J2 inhibits macrophage colonization by Salmonella enterica serovar Typhimurium.

    PubMed

    Buckner, Michelle M C; Antunes, L Caetano M; Gill, Navkiran; Russell, Shannon L; Shames, Stephanie R; Finlay, B Brett

    2013-01-01

    15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2) is an anti-inflammatory downstream product of the cyclooxygenase enzymes. It has been implicated to play a protective role in a variety of inflammatory mediated diseases, including rheumatoid arthritis, neural damage, and myocardial infarctions. Here we show that 15d-PGJ2 also plays a role in Salmonella infection. Salmonella enterica Typhimurium is a Gram-negative facultative intracellular pathogen that is able to survive and replicate inside phagocytic immune cells, allowing for bacterial dissemination to systemic sites. Salmonella species cause a wide range of morbidity and mortality due to gastroenteritis and typhoid fever. Previously we have shown that in mouse models of typhoid fever, Salmonella infection causes a major perturbation in the prostaglandin pathway. Specifically, we saw that 15d-PGJ2 production was significantly increased in both liver and feces. In this work we show that 15d-PGJ2 production is also significantly increased in macrophages infected with Salmonella. Furthermore, we show that the addition of 15d-PGJ2 to Salmonella infected RAW264.7, J774, and bone marrow derived macrophages is sufficient to significantly reduce bacterial colonization. We also show evidence that 15d-PGJ2 is reducing bacterial uptake by macrophages. 15d-PGJ2 reduces the inflammatory response of these infected macrophages, as evidenced by a reduction in the production of cytokines and reactive nitrogen species. The inflammatory response of the macrophage is important for full Salmonella virulence, as it can give the bacteria cues for virulence. The reduction in bacterial colonization is independent of the expression of Salmonella virulence genes SPI1 and SPI2, and is independent of the 15d-PGJ2 ligand PPAR-γ. 15d-PGJ2 also causes an increase in ERK1/2 phosphorylation in infected macrophages. In conclusion, we show here that 15d-PGJ2 mediates the outcome of bacterial infection, a previously unidentified role for this

  12. Molecular inhibition of prostaglandin E2 with GW627368X: Therapeutic potential and preclinical safety assessment in mouse sarcoma model.

    PubMed

    Parida, Sheetal; Parekh, Aditya; Dey, Goutam; Ghosh, Sukhen C; Mandal, Mahitosh

    2015-01-01

    Prostaglandin E2, the major COX-2 product, acts via 4 functionally distinct prostanoid receptors, EP(1-4). PGE-2, through its receptors, feeds back to positively increase COX-2 expression augmenting its own synthesis thereby driving angiogenesis, while suppressing apoptosis and innate immunity. In addition to the well characterized PGE2/EP4/cAMP/PKA/CREB, EP4 activation increases GSK3 phosphorylation via PI3K and Akt consequently reducing β-catenin phosphorylation. EP4 induces angiogenesis by enhancing VEGF production via ERK activation. These effects of EP4 are asserted either directly or via EGFR transactivation depending on the type of cancer. In view of the safety concerns regarding long term use of COX-2 inhibitors and to find more effective alternatives, we evaluated the potential of EP4 prostanoid receptor as a target for treating cancer progression using a highly selective EP4 antagonist, 4-(4,9-diethoxy-1,3-dihydro-1-oxo-2H-benz[f]isoindol-2-yl)-N-(phenylsulfonyl)-benzeneacetamide. Oral administration of GW627368X showed significant tumor regression characterized by tumor reduction and induction of apoptosis. Reduction in prostaglandin E2 synthesis also led to reduced level of VEGF in plasma. Regulation of multiple pathways downstream of EP4 was evident by down regulation of COX-2, p-Akt, p-MAPK and p-EGFR. Considering wide distribution of the EP4 prostanoid receptor in major organs and the array of physiological processes it contributes to, the safety profile of the drug was analyzed. No major organ toxicity, immunosupression, behavioral change or change in blood parameters attributable to the drug was observed. The results assert the significance of EP4 prostanoid receptor as a therapeutic target as well as the safety of EP4 blockade by GW627368X. PMID:25894216

  13. Inhibition of [3H]catecholamine release and Ca2+ currents by prostaglandin E2 in rabbit carotid body chemoreceptor cells.

    PubMed Central

    Gómez-Niño, A; López-López, J R; Almaraz, L; González, C

    1994-01-01

    Basal release of [3H]catecholamine ([3H]CA) from rabbit carotid bodies (CBs), previously incubated in the presence of [3H]tyrosine, was not significantly modified by prostaglandin E2 (PGE2). On the contrary, PGE2 (3-300 nM) produced a dose-dependent inhibition of the low PO2-evoked release of [3H]CA. The inhibition was greatest (55%) at a low intensity of hypoxic stimulation (incubating solution PO2 approximately 66 mmHg) and decreased with increasing intensities of hypoxia. Chronic denervation of the CB did not modify the response to PGE2. The release of [3H]CA induced by incubating the CBs in a hypercapnic-acidic solution (PCO2 approximately 132 mmHg; pH = 6.60) and by dinitrophenol (100 microM) was not significantly modified by 300 nM PGE2. PGE2 (300 nM) inhibited the release of [3H]CA elicited by incubating the CBs in a high K+ (35 mM)-containing solution. The release response elicited by high K+ (25 mM) was strongly augmented by a dihydropyridine agonist of Ca2+ channels, Bay K 8644, at a concentration of 1 microM. The Bay K 8644 effect was partly inhibited by PGE2 (300 nM). Using whole-cell recordings in freshly dispersed or short-term cultured chemoreceptor cells from adult rabbits it was found that Ca2+ currents (ICa) were reversibly inhibited by bath application of PGE2. A good parallelism exits between the dose-response curves for PGE2 inhibition of ICa in isolated chemoreceptor cells and high extracellular [K+]- or hypoxia-evoked release of [3H]CA from the whole CB.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7519263

  14. Pseudohypericin is necessary for the Light-Activated Inhibition of Prostaglandin E2 pathways by a 4 component system mimicking an Hypericum perforatum fraction

    PubMed Central

    Hammer, Kimberly D. P.; Hillwig, Matthew L.; Neighbors, Jeffrey D.; Sim, Young-Je; Kohut, Marian L.; Wiemer, David F.; Wurtele, Eve S.; Birt, Diane F.

    2008-01-01

    Hypericum perforatum (Hp) has been used medicinally to treat a variety of conditions including mild-to-moderate depression. Recently, several anti-inflammatory activities of Hp have been reported. An ethanol extract of Hp was fractionated with the guidance of an anti-inflammatory bioassay (lipopolysaccharide (LPS)-induced prostaglandin E2 production (PGE2)), and four constituents were identified. When combined together at concentrations detected in the Hp fraction to make a 4 component system, these constituents (0.1 µM chlorogenic acid, 0.08 µM amentoflavone, 0.07 µM quercetin, and 0.03 µM pseudohypericin) explained the majority of the activity of the fraction when activated by light, but only partially explained the activity of this Hp fraction in dark conditions. One of the constituents, light-activated pseudohypericin, was necessary, but not sufficient to explain the reduction in LPS-induced PGE2 of the 4 component system. The Hp fraction and the 4 component system inhibited lipoxygenase and cytosolic phospholipase A2, two enzymes in the PGE2-mediated inflammatory response. The 4 component system inhibited the production of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), and the Hp fraction inhibited the anti-inflammatory cytokine interleukin-10 (IL-10). Thus, the Hp fraction and selected constituents from this fraction showed evidence of blocking pro-inflammatory mediators but not enhancing inflammation-suppressing mediators. PMID:18707743

  15. Tulathromycin Exerts Proresolving Effects in Bovine Neutrophils by Inhibiting Phospholipases and Altering Leukotriene B4, Prostaglandin E2, and Lipoxin A4 Production

    PubMed Central

    Fischer, Carrie D.; Duquette, Stephanie C.; Renaux, Bernard S.; Feener, Troy D.; Morck, Douglas W.; Hollenberg, Morley D.; Lucas, Merlyn J.

    2014-01-01

    The accumulation of neutrophils and proinflammatory mediators, such as leukotriene B4 (LTB4), is a classic marker of inflammatory disease. The clearance of apoptotic neutrophils, inhibition of proinflammatory signaling, and production of proresolving lipids (including lipoxins, such as lipoxin A4 [LXA4]) are imperative for resolving inflammation. Tulathromycin (TUL), a macrolide used to treat bovine respiratory disease, confers immunomodulatory benefits via mechanisms that remain unclear. We recently reported the anti-inflammatory properties of TUL in bovine phagocytes in vitro and in Mannheimia haemolytica-challenged calves. The findings demonstrated that this system offers a powerful model for investigating novel mechanisms of pharmacological immunomodulation. In the present study, we examined the effects of TUL in a nonbacterial model of pulmonary inflammation in vivo and characterized its effects on lipid signaling. In bronchoalveolar lavage (BAL) fluid samples from calves challenged with zymosan particles (50 mg), treatment with TUL (2.5 mg/kg of body weight) significantly reduced pulmonary levels of LTB4 and prostaglandin E2 (PGE2). In calcium ionophore (A23187)-stimulated bovine neutrophils, TUL inhibited phospholipase D (PLD), cytosolic phospholipase A2 (PLA2) activity, and the release of LTB4. In contrast, TUL promoted the secretion of LXA4 in resting and A23187-stimulated neutrophils, while levels of its precursor, 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE], were significantly lower. These findings indicate that TUL directly modulates lipid signaling by inhibiting the production of proinflammatory eicosanoids and promoting the production of proresolving lipoxins. PMID:24820086

  16. The cyclopentenone 15-deoxy-delta(12,14)-prostaglandin J2 inhibits G1/S transition and retinoblastoma protein phosphorylation in immortalized lymphocytes from Alzheimer's disease patients.

    PubMed

    Muñoz, Ursula; de Las Cuevas, Natividad; Bartolomé, Fernando; Hermida, Ofelia G; Bermejo, Félix; Martín-Requero, Angeles

    2005-10-01

    Epidemiologic studies indicated that non-steroidal anti-inflammatory drugs (NSAIDs) might prevent or delay the clinical features of Alzheimer disease (AD). The pharmacological activity of NSAIDs is generally attributed to inhibition of cyclooxygenase and peroxisome proliferator-activated receptor gamma (PPARgamma) activation. Based on the antineoplastic and apoptotic effects of PPARgamma activation in a number of cell types, we hypothesized that NSAIDs could protect neurons by controlling the regulation of cell cycle. Recent work suggests that uncoordinated expression of cell cycle molecules and perturbation of cell cycle checkpoints may be one of the mechanisms by which post-mitotic neurons die. Since cell cycle dysfunction is not restricted to neurons in AD, we found it interesting to study the role of PPARgamma activation on cell proliferation in immortalized lymphocytes from AD patients. We report here that 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2), but not NSAIDs or thiazolidinediones inhibited the serum-mediated enhancement of cell proliferation in AD by blocking the events critical for G1/S transition. The cyclopentenone induced a partial inhibition of retinoblastoma protein phosphorylation and increased levels of the CDK inhibitor p27kip1. PMID:16061222

  17. Effects of membrane polyunsaturated fatty acids on opiate peptide inhibition of basal and prostaglandin E1-stimulated cyclic AMP formation in intact N1E-115 neuroblastoma cells.

    PubMed

    Murphy, M G; Moak, C M; Rao, B G

    1987-12-01

    The effects of membrane polyunsaturated fatty acids (PUFA) on opiate peptide-mediated inhibition of basal and prostaglandin E1-stimulated cyclic AMP formation were examined in intact N1E-115 neuroblastoma cells. Addition of opiate peptides such as methionine 5-enkephalin (metEnk) to control cultures and to cultures that had been supplemented for 48 hr with 50 microM linoleic acid resulted in dose-dependent decreases in cAMP formation; these decreases were blocked by naloxone. Maximum inhibition of basal cyclase activity was 50-55% in both control and PUFA-enriched cells; however, half-maximal inhibition required ten times more metEnk in supplemented cultures than in controls. This is consistent with our observation that the affinity of binding of [tyrosyl-3',5'-3H(N)](2-D-alanine-5-D-leucine)enkephalin ([3H]DADLE) to intact PUFA-enriched cells was lower than that to control cells. Receptor density was not modified as a result of supplementation. Addition of prostaglandin E1 (PGE1) to the cells produced rapid dose-dependent increases in cAMP formation. Maximum responses were higher in PUFA-enriched than in control cells (1924 and 972 pmol cAMP formed/mg protein respectively). Also, the apparent value for EC50 for PGE1 was consistently lower in supplemented cultures. MetEnk reduced PGE1-stimulated cAMP formation by 45-55% in both control and supplemented cells, and values for IC50 were similar (approximately 30 nM) in both. In the presence of the opiate peptide, values for EC50 for PGE1 were similar in control and PUFA-enriched cultures (0.07 and 0.09 microM respectively). The data from these studies suggest that membrane PUFA increase the efficiency of coupling of receptors that stimulate cAMP formation and decrease the efficiency of those that mediate inhibition. PMID:2825714

  18. Inhibition of P2Y6 receptor-mediated phospholipase C activation and Ca(2+) signalling by prostaglandin E2 in J774 murine macrophages.

    PubMed

    Ito, Masaaki; Matsuoka, Isao

    2015-02-15

    Extracellular nucleotides act as inflammatory mediators through activation of multiple purinoceptors. Under inflammatory conditions, the purinergic signalling is affected by various inflammatory mediators. We previously showed that prostaglandin (PG) E2 suppressed the elevation of intracellular Ca(2+) concentration ([Ca(2+)]i) stimulated by P2X4, P2Y2, and P2Y6 receptors in J774 murine macrophages. In this study, we examined the mechanism of PGE2 inhibitory effects on P2Y6 receptor-mediated function in J774 cells. The P2Y6 receptor agonist UDP induced a sustained elevation of [Ca(2+)]i by stimulating the phospholipase C (PLC) signalling pathway. PGE2 inhibited [Ca(2+)]i elevation and phosphatidylinositol (PI) hydrolysis in a concentration-dependent manner. J774 cells highly expressed the E-type prostanoid 2 (EP2) receptor subtype, a Gs-coupled receptor. PGE2 and a selective EP2 receptor agonist caused cyclic AMP (cAMP) accumulation in J774 cells. The inhibitory effects of PGE2 on P2Y6 receptor-mediated responses were mimicked by the selective EP2 receptor agonist. Although EP2 receptor is linked to adenylyl cyclase activation, PGE2-induced inhibition of Ca(2+) response and PI hydrolysis could not be mimicked by a lipophilic cAMP derivative, dibutyryl cAMP, or an adenylyl cyclase activator, forskolin. The inhibition of UDP-induced PLC activation by PGE2 was not affected by down-regulation of protein kinase C by phorbol-12-myristate-13-acetate treatment. PGE2 inhibited PLC activation induced by aluminium fluoride, but not by the Ca(2+)-ionophore, ionomycin. Finally, the inhibition of UDP-induced PLC activation by PGE2 was impaired by Gs knockdown using siRNA. These results suggest that EP2 receptor activation in macrophages negatively controls the Gq/11-PLC signalling through a Gs-mediated, but cAMP-independent signalling mechanism. PMID:25614334

  19. Contrasting effects of peroxisome-proliferator-activated receptor (PPAR)γ agonists on membrane-associated prostaglandin E2 synthase-1 in IL-1β-stimulated rat chondrocytes: evidence for PPARγ-independent inhibition by 15-deoxy-Δ12,14prostaglandin J2

    PubMed Central

    Bianchi, Arnaud; Moulin, David; Sebillaud, Sylvie; Koufany, Meriem; Galteau, Marie-Madeleine; Netter, Patrick; Terlain, Bernard; Jouzeau, Jean-Yves

    2005-01-01

    Microsomal prostaglandin E synthase (mPGES)-1 is a newly identified inducible enzyme of the arachidonic acid cascade with a key function in prostaglandin (PG)E2 synthesis. We investigated the kinetics of inducible cyclo-oxygenase (COX)-2 and mPGES-1 expression with respect to the production of 6-keto-PGF1α and PGE2 in rat chondrocytes stimulated with 10 ng/ml IL-1β, and compared their modulation by peroxisome-proliferator-activated receptor (PPAR)γ agonists. Real-time PCR analysis showed that IL-1β induced COX-2 expression maximally (37-fold) at 12 hours and mPGES-1 expression maximally (68-fold) at 24 hours. Levels of 6-keto-PGF1α and PGE2 peaked 24 hours after stimulation with IL-1β; the induction of PGE2 was greater (11-fold versus 70-fold, respectively). The cyclopentenone 15-deoxy-Δ12,14prostaglandin J2 (15d-PGJ2) decreased prostaglandin synthesis in a dose-dependent manner (0.1 to 10 μM), with more potency on PGE2 level than on 6-keto-PGF1α level (-90% versus -66% at 10 μM). A high dose of 15d-PGJ2 partly decreased COX-2 expression but decreased mPGES-1 expression almost completely at both the mRNA and protein levels. Rosiglitazone was poorly effective on these parameters even at 10 μM. Inhibitory effects of 10 μM 15d-PGJ2 were neither reduced by PPARγ blockade with GW-9662 nor enhanced by PPARγ overexpression, supporting a PPARγ-independent mechanism. EMSA and TransAM® analyses demonstrated that mutated IκBα almost completely suppressed the stimulating effect of IL-1β on mPGES-1 expression and PGE2 production, whereas 15d-PGJ2 inhibited NF-κB transactivation. These data demonstrate the following in IL-1-stimulated rat chondrocytes: first, mPGES-1 is rate limiting for PGE2 synthesis; second, activation of the prostaglandin cascade requires NF-κB activation; third, 15d-PGJ2 strongly inhibits the synthesis of prostaglandins, in contrast with rosiglitazone; fourth, inhibition by 15d-PGJ2 occurs independently of PPARγ through inhibition of

  20. Inhibition by morphine of prostaglandin E1-stimulated secretion and cyclic adenosine 3',5'-monophosphate formation in the rat jejunum in vivo.

    PubMed Central

    Beubler, E.; Lembeck, F.

    1980-01-01

    1 The effects were studied of prostaglandin E1 (PGE1), theophylline and morphine on net water flux and mucosal cyclic adenosine 3',5'-monophosphate (cyclic AMP) levels in the jejunum of anaesthetized rats in vivo. 2 Infusion of PGE1 (3.2 micrograms/min, i.a.) caused a reversal from net water absorption to net secretion and enhanced the mucosal cyclic AMP content by 54%. 3 Theophylline (5 mg/ml, intraluminal) similarly produced a reversal from net water absorption to net secretion and increased mucosal cyclic AMP content by 54%. Additional intra-arterial infusion of PGE1 resulted in a massive increase in net water secretion and an increase in mucosal cyclic AMP content by about 200%. 4 Pretreatment with morphine (10 mg/kg, s.c.) reduced the effect of PGE1 on net water flux and completely inhibited its effect on the mucosal cyclic AMP content. Naloxone (10 mg/kg, s.c.) abolished both effects of morphine. 5 A good correlation (r = 0.99) was demonstrated between mucosal cyclic AMP levels and net water flux. 6 The present results demonstrate that PGE1 stimulates intestinal fluid secretion by increasing mucosal cyclic AMP levels. The antidiarrhoeal effect of morphine can be explained by its inhibition of the PGE-mediated increase in cyclic AMP levels, which, in turn, leads to a reduction in intestinal secretion. PMID:6301596

  1. Pseudohypericin is necessary for the light-activated inhibition of prostaglandin E2 pathways by a 4 component system mimicking an Hypericum perforatum fraction.

    PubMed

    Hammer, Kimberly D P; Hillwig, Matthew L; Neighbors, Jeffrey D; Sim, Young-Je; Kohut, Marian L; Wiemer, David F; Wurtele, Eve S; Birt, Diane F

    2008-09-01

    Hypericum perforatum (Hp) has been used medicinally to treat a variety of conditions including mild-to-moderate depression. Recently, several anti-inflammatory activities of Hp have been reported. An ethanol extract of Hp was fractionated with the guidance of an anti-inflammatory bioassay (lipopolysaccharide (LPS)-induced prostaglandin E2 production (PGE2)), and four constituents were identified. When combined together at concentrations detected in the Hp fraction to make a 4 component system, these constituents (0.1microM chlorogenic acid (compound 1), 0.08microM amentoflavone (compound 2), 0.07microM quercetin (compound 3), and 0.03microM pseudohypericin (compound 4)) explained the majority of the activity of the fraction when activated by light, but only partially explained the activity of this Hp fraction in dark conditions. One of the constituents, light-activated pseudohypericin, was necessary, but not sufficient to explain the reduction in LPS-induced PGE2 of the 4 component system. The Hp fraction and the 4 component system inhibited lipoxygenase and cytosolic phospholipase A2, two enzymes in the PGE2-mediated inflammatory response. The 4 component system inhibited the production of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha), and the Hp fraction inhibited the anti-inflammatory cytokine interleukin-10 (IL-10). Thus, the Hp fraction and selected constituents from this fraction showed evidence of blocking pro-inflammatory mediators but not enhancing inflammation-suppressing mediators. PMID:18707743

  2. Inhibition of prostaglandin synthesis and actions by genistein in human prostate cancer cells and by soy isoflavones in prostate cancer patients.

    PubMed

    Swami, Srilatha; Krishnan, Aruna V; Moreno, Jacqueline; Bhattacharyya, Rumi S; Gardner, Christopher; Brooks, James D; Peehl, Donna M; Feldman, David

    2009-05-01

    Soy and its constituent isoflavone genistein inhibit the development and progression of prostate cancer (PCa). Our study in both cultured cells and PCa patients reveals a novel pathway for the actions of genistein, namely the inhibition of the synthesis and biological actions of prostaglandins (PGs), known stimulators of PCa growth. In the cell culture experiments, genistein decreased cyclooxygenase-2 (COX-2) mRNA and protein expression in both human PCa cell lines (LNCaP and PC-3) and primary prostate epithelial cells and increased 15-hydroxyprostaglandin dehydrogenase (15-PGDH) mRNA levels in primary prostate cells. As a result genistein significantly reduced the secretion of PGE(2) by these cells. EP4 and FP PG receptor mRNA were also reduced by genistein, providing an additional mechanism for the suppression of PG biological effects. Further, the growth stimulatory effects of both exogenous PGs and endogenous PGs derived from precursor arachidonic acid were attenuated by genistein. We also performed a pilot randomised double blind clinical study in which placebo or soy isoflavone supplements were given to PCa patients in the neo-adjuvant setting for 2 weeks before prostatectomy. Gene expression changes were measured in the prostatectomy specimens. In PCa patients ingesting isoflavones, we observed significant decreases in prostate COX-2 mRNA and increases in p21 mRNA. There were significant correlations between COX-2 mRNA suppression, p21 mRNA stimulation and serum isoflavone levels. We propose that the inhibition of the PG pathway contributes to the beneficial effect of soy isoflavones in PCa chemoprevention and/or treatment. PMID:19127598

  3. Expression and modulation of IL-1 alpha in murine keratinocytes

    SciTech Connect

    Ansel, J.C.; Luger, T.A.; Lowry, D.; Perry, P.; Roop, D.R.; Mountz, J.D.

    1988-04-01

    Murine and human keratinocytes produce an IL-1-like factor that appears to be similar if not identical to monocyte-derived IL-1. IL-1 may be an important mediator in cutaneous inflammatory responses, however, little is currently known concerning factors that may modulate IL-1 expression in keratinocytes. To address this issue we examined the effect of LPS, UV, and the cell differentiation state on murine keratinocyte IL-1 mRNA expression. Our results indicated that as with the murine P388D1 monocyte cell line, PAM 212 keratinocytes constitutively express abundant amounts of IL-1 alpha mRNA. On exposure to LPS (100 micrograms/ml) for 8 h there was more than 10 times the increase in PAM 212 IL-1 alpha mRNA which was accompanied by a sixfold increase in supernatant IL-1 activity. Similarly UV irradiation had a significant effect on keratinocyte IL-1 alpha expression. High dose UV (300 mJ/cm2) inhibited PAM 212 IL-1 alpha expression at 4, 8, 24, 48 h post-UV whereas a lower dose of UV (100 mJ/cm2) inhibited UV at 4 and 8 h post-UV, but induced IL-1 expression at 24 and 48 h post-UV. The expression of IL-1 alpha varied with the differentiation state of the keratinocytes. Freshly removed newborn murine keratinocytes were found to constitutively express IL-1 alpha mRNA. Keratinocytes grown in low (Ca2+) tissue culture media (0.05 mM) for 6 days, functionally and phenotypically become undifferentiated and express increased quantities of IL-1 alpha mRNA, whereas cells grown in high (Ca2+) media (1.2 mM) for 6 days become terminally differentiated and IL-1 expression ceased. Keratinocytes cultured for 3 days in low (Ca2+) conditions expressed an intermediate level of IL-1 alpha. In contrast, little or no IL-1 beta mRNA was detected in either the PAM 212 cells or newborn murine keratinocytes.

  4. Prostaglandin E2 Inhibits NLRP3 Inflammasome Activation through EP4 Receptor and Intracellular Cyclic AMP in Human Macrophages.

    PubMed

    Sokolowska, Milena; Chen, Li-Yuan; Liu, Yueqin; Martinez-Anton, Asuncion; Qi, Hai-Yan; Logun, Carolea; Alsaaty, Sara; Park, Yong Hwan; Kastner, Daniel L; Chae, Jae Jin; Shelhamer, James H

    2015-06-01

    PGE2 is a potent lipid mediator involved in maintaining homeostasis but also promotion of acute inflammation or immune suppression in chronic inflammation and cancer. Nucleotide-binding domain, leucine-rich repeat-containing protein (NLR)P3 inflammasome plays an important role in host defense. Uncontrolled activation of the NLRP3 inflammasome, owing to mutations in the NLRP3 gene, causes cryopyrin-associated periodic syndromes. In this study, we showed that NLRP3 inflammasome activation is inhibited by PGE2 in human primary monocyte-derived macrophages. This effect was mediated through PGE2 receptor subtype 4 (EP4) and an increase in intracellular cAMP, independently of protein kinase A or exchange protein directly activated by cAMP. A specific agonist of EP4 mimicked, whereas its antagonist or EP4 knockdown reversed, PGE2-mediated NLRP3 inhibition. PGE2 caused an increase in intracellular cAMP. Blockade of adenylate cyclase by its inhibitor reversed PGE2-mediated NLRP3 inhibition. Increase of intracellular cAMP by an activator of adenylate cyclase or an analog of cAMP, or a blockade of cAMP degradation by phosphodiesterase inhibitor decreased NLRP3 activation. Protein kinase A or exchange protein directly activated by cAMP agonists did not mimic, and their antagonists did not reverse, PGE2-mediated NLRP3 inhibition. Additionally, constitutive IL-1β secretion from LPS-primed PBMCs of cryopyrin-associated periodic fever syndromes patients was substantially reduced by high doses of PGE2. Moreover, blocking cytosolic phospholipase A2α by its inhibitor or small interfering RNA or inhibiting cyclooxygenase 2, resulting in inhibition of endogenous PGE2 production, caused an increase in NLRP3 inflammasome activation. Our results suggest that PGE2 might play a role in maintaining homeostasis during the resolution phase of inflammation and might serve as an autocrine and paracrine regulator. PMID:25917098

  5. 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.

  6. Pheophytin a Inhibits Inflammation via Suppression of LPS-Induced Nitric Oxide Synthase-2, Prostaglandin E2, and Interleukin-1β of Macrophages

    PubMed Central

    Lin, Chun-Yu; Lee, Chien-Hsing; Chang, Yu-Wei; Wang, Hui-Min; Chen, Chung-Yi; Chen, Yen-Hsu

    2014-01-01

    Inflammation is a serious health issue worldwide that induces many diseases such as sepsis. There has been a vast search for potentially effective drugs to decrease mortality from sepsis. Pheophytin a is a chlorophyll-related compound derived from green tea. We found that pre-treatment with pheophytin a suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2), and interleukin-1β in RAW 264.7 macrophages. NO synthase-2 (NOS2) and cyclooxygenase-2 (COX-2) expression levels were repressed by pre-treatment with pheophytin a at both the transcriptional and translational levels. Pheophytin a inhibited NOS2 promoter activity, but not its mRNA stability, through extracellular signal-regulated kinase (ERK1/2). This suppression was reversed by ERK1/2 inhibitor (U0126). Pheophytin a reduced signal transducers and activators of transcription 1 (STAT-1) activation, without an obvious influence on activator protein-1 (AP-1) and nuclear factor κB (NF-κB). These results suggest that pheophytin a functions by down-regulating the transcriptional levels of inflammatory mediators and blocking the ERK and STAT-1 pathways. PMID:25501336

  7. Local nitric oxide release does not affect tachyphylaxis to angiotensin II in dorsal hand veins in man in the presence of prostaglandin synthesis inhibition

    PubMed Central

    de Haas, S L; Wilkinson, I B; Boyd, J L; Webb, D J

    2002-01-01

    Aims Local prostaglandin (PG) production contributes to tachyphylaxis to angiotensin II (ANGII) in veins. Our aim was to assess the hypothesis that local nitric oxide (NO) generation is also, in part, responsible for tachyphylaxis to ANGII in veins, using the Aellig dorsal hand vein technique. Methods Eight healthy male volunteers received 600 mg of aspirin (orally) to inhibit PG production. The venoconstrictor effects of ANGII and noradrenaline (NA) were then compared in dorsal hand veins during co-infusion of the NO synthase inhibitor L-NMMA or saline, on separate occasions. Results ANGII and NA produced a similar degree of initial venoconstriction. However, the response to ANGII was significantly attenuated by 12 min compared with NA (AUC 147 ± 38 vs 196 ± 40, respectively; [95% confidence interval for difference: 7, 92], P = 0.02). Infusion of L-NMMA did not influence the response to ANGII or NA (P = 0.2 and P = 0.3, respectively). Conclusions Tachyphylaxis to ANGII in dorsal hand veins is not dependent on local NO release. PMID:11851644

  8. 15-Deoxy-Δ12,14-Prostaglandin J2 Inhibits Homing of Bone Marrow-Derived Mesenchymal Stem Cells Triggered by Chronic Liver Injury via Redox Pathway

    PubMed Central

    Liu, Xin; Jia, Shuangshuang; Li, Weiyang; Yang, Le; Yang, Lin; Wang, Lin; Li, Liying

    2015-01-01

    It has been reported that bone marrow-derived mesenchymal stem cells (BMSCs) have capacity to migrate to the damaged liver and contribute to fibrogenesis in chronic liver diseases. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand for peroxisome proliferator-activated receptor gamma (PPARγ), is considered a new inhibitor of cell migration. However, the actions of 15d-PGJ2 on BMSC migration remain unknown. In this study, we investigated the effects of 15d-PGJ2 on the migration of BMSCs using a mouse model of chronic liver fibrosis and primary mouse BMSCs. Our results demonstrated that in vivo, 15d-PGJ2 administration inhibited the homing of BMSCs to injured liver by flow cytometric analysis and, in vitro, 15d-PGJ2 suppressed primary BMSC migration in a dose-dependent manner determined by Boyden chamber assay. Furthermore, the repressive effect of 15d-PGJ2 was blocked by reactive oxygen species (ROS) inhibitor, but not PPARγ antagonist, and action of 15d-PGJ2 was not reproduced by PPARγ synthetic ligands. In addition, 15d-PGJ2 triggered a significant ROS production and cytoskeletal remodeling in BMSCs. In conclusion, our results suggest that 15d-PGJ2 plays a crucial role in homing of BMSCs to the injured liver dependent on ROS production, independently of PPARγ, which may represent a new strategy in the treatment of liver fibrosis. PMID:26457076

  9. NO2 inhalation promotes Alzheimer’s disease-like progression: cyclooxygenase-2-derived prostaglandin E2 modulation and monoacylglycerol lipase inhibition-targeted medication

    PubMed Central

    Yan, Wei; Yun, Yang; Ku, Tingting; Li, Guangke; Sang, Nan

    2016-01-01

    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. PMID:26928013

  10. Prostaglandin and myokine involvement in the cyclooxygenase-inhibiting drug enhancement of skeletal muscle adaptations to resistance exercise in older adults.

    PubMed

    Trappe, Todd A; Standley, Robert A; Jemiolo, Bozena; Carroll, Chad C; Trappe, Scott W

    2013-02-01

    Twelve weeks of resistance training (3 days/wk) combined with daily consumption of the cyclooxygenase-inhibiting drugs acetaminophen (4.0 g/day; n = 11, 64 ± 1 yr) or ibuprofen (1.2 g/day; n = 13, 64 ± 1 yr) unexpectedly promoted muscle mass and strength gains 25-50% above placebo (n = 12, 67 ± 2 yr). To investigate the mechanism of this adaptation, muscle biopsies obtained before and ∼72 h after the last training bout were analyzed for mRNA levels of prostaglandin (PG)/cyclooxygenase pathway enzymes and receptors [arachidonic acid synthesis: cytosolic phospholipase A(2) (cPLA(2)) and secreted phospholipase A(2) (sPLA(2)); PGF(2α) synthesis: PGF(2α) synthase and PGE(2) to PGF(2α) reductase; PGE(2) synthesis: PGE(2) synthase-1, -2, and -3; PGF(2α) receptor and PGE(2) receptor-4], cytokines and myokines involved in skeletal muscle adaptation (TNF-α, IL-1β, IL-6, IL-8, IL-10), and regulators of muscle growth [myogenin, myogenic regulatory factor-4 (MRF4), myostatin] and atrophy [Forkhead box O3A (FOXO3A), atrogin-1, muscle RING finger protein 1 (MuRF-1), inhibitory κB kinase β (IKKβ)]. Training increased (P < 0.05) cPLA(2), PGF(2α) synthase, PGE(2) to PGF(2α) reductase, PGE(2) receptor-4, TNF-α, IL-1β, IL-8, and IKKβ. However, the PGF(2α) receptor was upregulated (P < 0.05) only in the drug groups, and the placebo group upregulation (P < 0.05) of IL-6, IL-10, and MuRF-1 was eliminated in both drug groups. These results highlight prostaglandin and myokine involvement in the adaptive response to exercise in older individuals and suggest two mechanisms underlying the enhanced muscle mass gains in the drug groups: 1) The drug-induced PGF(2α) receptor upregulation helped offset the drug suppression of PGF(2α)-stimulated protein synthesis after each exercise bout and enhanced skeletal muscle sensitivity to this stimulation. 2) The drug-induced suppression of intramuscular PGE(2) production increased net muscle protein balance after each exercise bout

  11. Low Concentrations of o,p’-DDT Inhibit Gene Expression and Prostaglandin Synthesis by Estrogen Receptor-Independent Mechanism in Rat Ovarian Cells

    PubMed Central

    Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

    2012-01-01

    o,p’-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p’-DDT at range of 0.3–500 ng/g (8.46×10−10 M−1.41×10−6 M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p’-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p’-DDT (10−12−10−8 M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p’-DDT at 0.5–1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p’-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p’-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p’-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p’-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

  12. 15-Deoxy-Δ{sup 12,14}-prostaglandin J{sub 2} inhibits IL-13 production in T cells via an NF-κB-dependent mechanism

    SciTech Connect

    Doyle, Marie-Christine; Tremblay, Sarah; Dumais, Nancy

    2013-02-15

    Highlights: ► 15d-PGJ{sub 2} decreased IL-13 mRNA transcription and secretion in activated T cells. ► IL-13 inhibition by 15d-PGJ{sub 2} is independent of PPAR-γ. ► The nuclear factor-κB mediates the 15d-PGJ{sub 2}-dependent down regulation of IL-13. -- Abstract: Interleukin (IL)-13 is a cytokine produced by activated CD4{sup +} T cells that plays a critical role in promoting allergic responses and tumor cell growth. The 15-deoxy-Δ{sup 12,14}-prostaglandin J{sub 2} (15d-PGJ{sub 2}) is a natural ligand for the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ), a known regulator of anti-inflammatory activities. We determined the effects of 15d-PGJ{sub 2} on IL-13 expression in the Jurkat E6.1 T-cell line and in peripheral blood mononuclear cells. Semi-quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay revealed that treatment of activated T cells with 15d-PGJ{sub 2} significantly decreased IL-13 mRNA transcription and secretion, respectively. This inhibition by 15d-PGJ{sub 2} was independent of PPAR-γ since treatment with GW9662, an irreversible antagonist of the nuclear receptor, produced no effect. Our data also revealed the involvement of nuclear factor-κB in mediating 15d-PGJ{sub 2}-dependent down regulation of IL-13 expression. Collectively, these results demonstrate the potential of 15d-PGJ{sub 2} in attenuating expression and production of IL-13 in activated T cells.

  13. Low concentrations of o,p'-DDT inhibit gene expression and prostaglandin synthesis by estrogen receptor-independent mechanism in rat ovarian cells.

    PubMed

    Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

    2012-01-01

    o,p'-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p'-DDT at range of 0.3-500 ng/g (8.46×10(-10) M-1.41×10(-6) M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p'-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p'-DDT (10(-12)-10(-8) M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p'-DDT at 0.5-1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p'-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p'-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p'-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p'-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

  14. Cyclic mechanical stretching and interleukin-1alpha synergistically up-regulate prostacyclin secretion in cultured human uterine myometrial cells.

    PubMed

    Korita, D; Itoh, H; Sagawa, N; Yura, S; Yoshida, M; Kakui, K; Takemura, M; Nuamah, M A; Fujii, S

    2004-03-01

    Prostacyclin (PGI2), a potent uterine smooth muscle relaxant, is postulated to be a major prostaglandin (PG) secreted from the human myometrium. PGI2 metabolite concentrations in the maternal plasma were reported to be elevated during pregnancy, especially during labor. Recently, we developed cultured human myometrial cells from pregnant women and reported that cyclic mechanical stretching mimicking labor increased PGI2 secretion from these cells by up-regulating PGI2 synthase promoter activities. Since elevation of cervical/vaginal interleukin-1alpha (IL-1alpha) concentrations is also a characteristic feature of delivery, and IL-1alpha is a known stimulator of PG synthesis, we investigated a possible synergistic effect of cyclic mechanical stretching and IL-1alpha on PGI2 production in cultured human myometrial cells. Treatment with IL-1alpha (10 ng/ml) significantly augmented (4- to 60-fold) the secretion of PGI2, prostaglandin E2 (PGE2), prostaglandin F2alpha (PGF2alpha) and thromboxane A2 (TXA2) from cultured human myometrial cells obtained from non-pregnant and pregnant women as well as in cultured human umbilical artery and cultured human coronary artery smooth muscle cells (p < 0.05 for all comparisons). However, labor-like cyclic mechanical stretching up-regulated IL-1alpha-augmented PGI2 secretion from myometrial cells obtained from non-pregnant and pregnant women 2.1- to 2.8-fold (p < 0.05 for all comparisons), but not PGE2, PGF2alpha nor TXA2. Moreover, such an augumentation of PGI2 secretion by cyclic mechanical stretching was not observed in cultured human umbilical artery nor in cultured human coronary artery smooth muscle cells. These results suggest that cyclic mechanical stretching by labor, in concert with IL-1alpha stimulation, contributes to the increase in myometrial PGI2 secretion during delivery. PMID:15255281

  15. Synthesis of unsymmetrical monocarbonyl curcumin analogues with potent inhibition on prostaglandin E2 production in LPS-induced murine and human macrophages cell lines.

    PubMed

    Mohd Aluwi, Mohd Fadhlizil Fasihi; Rullah, Kamal; Yamin, Bohari M; Leong, Sze Wei; Abdul Bahari, Mohd Nazri; Lim, Sock Jin; Mohd Faudzi, Siti Munirah; Jalil, Juriyati; Abas, Faridah; Mohd Fauzi, Norsyahida; Ismail, Nor Hadiani; Jantan, Ibrahim; Lam, Kok Wai

    2016-05-15

    The syntheses and bioactivities of symmetrical curcumin and its analogues have been the subject of interest by many medicinal chemists and pharmacologists over the years. To improve our understanding, we have synthesized a series of unsymmetrical monocarbonyl curcumin analogues and evaluated their effects on prostaglandin E2 production in lipopolysaccharide-induced RAW264.7 and U937 cells. Initially, compounds 8b and 8c exhibited strong inhibition on the production of PGE2 in both LPS-stimulated RAW264.7 (8b, IC50=12.01μM and 8c, IC50=4.86μM) and U937 (8b, IC50=3.44μM and 8c, IC50=1.65μM) cells. Placing vanillin at position Ar2 further improved the potency when both compounds 15a and 15b significantly lowered the PGE2 secretion level (RAW264.7: 15a, IC50=0.78μM and 15b, IC50=1.9μM while U937: 15a, IC50=0.95μM and 15b, IC50=0.92μM). Further experiment showed that compounds 8b, 8c, 15a and 15b did not target the activity of downstream inflammatory COX-2 mediator. Finally, docking simulation on protein targets COX-2, IKK-β, ERK, JNK2, p38α and p38β were performed using the conformation of 15a determined by single-crystal XRD. PMID:27040659

  16. Prostaglandin E2 requirement for transforming growth factor beta 1 inhibition of elicited macrophage 14 kDa phospholipase A2 release.

    PubMed Central

    McCord, M.; Bolognese, B.; Marshall, L. A.

    1995-01-01

    1. Cultured elicited-peritoneal macrophages release a soluble type II 14 kDa phospholipase A2 (PLA2) over time, reaching a plateau by 20-24 h of incubation and maintaining these levels over 72 h. Prostaglandin E2 (PGE2) is also produced but does not plateau until 48-72 h. 2. Transforming growth factor beta 1 (TGF beta 1) reduces cellular 14 kDa PLA2 and its subsequent release by approximately half, but does not alter PGE2 production. Co-incubation of TGF beta 1 with indomethacin interfered, in a concentration-dependent manner, with the ability of TGF beta 1 to reduce cellular 14 kDa PLA2 and its subsequent release over 24 h. The regulation of TGF beta 1 was not specific to indomethacin since other non-steroidal anti-inflammatory drugs had the same effect. This suggested that cyclooxygenase activity was essential for TGF beta 1 to exert its effect and indeed, the addition of exogenous PGE2 restored the TGF beta 1 action. 3. PGE2 alone exerted a concentration-dependent negative feedback action on elicited-macrophage 14 kDa PLA2 release. The inhibitory concentration (IC50 = approximately 180 ng PGE2 ml-1) approximated the PGE2 levels measured in the 24 h macrophage conditioned media (85-140 ng PGE2 ml-1) where PLA2 release began to plateau. Further, incubation of cells with indomethacin over 48 h resulted in the enhancement of 14 kDa PLA2 activity compared to that released from untreated cells. Forskolin failed to inhibit 14 kDa PLA2 release, suggesting PGE2 was not acting through an increase in adenylate cyclase. 4. Taken together, the data are consistent with the immunosuppressive aspects reported for both mediators during inflammation and demonstrates the requirement of PGE2 for TGF beta 1 action on the elicited macrophage. Images Figure 3 PMID:8590973

  17. Anorectic activity of prostaglandin precursors.

    PubMed Central

    Doggett, N S; Jawaharlal, K

    1977-01-01

    1 Intraperitoneal and intragastric (i.g.) administration of prostaglandin precursors arachidonic (2 mg, 15 mg/kg, i.p; 30 mg/kg i.g.), linolenic (100 mg/kg i.p.; 200 mg/kg, i.g.) and linoleic (15, 100 mg/kg, i.p.; 100 mg/kg, i.g.) acids to 22 h food-deprived rats inhibits food intake. 2 This anorexia is similar to that induced by prostaglandin F2alpha (1 mg/kg, i.p.). 3 At anorectic doses these fatty acids do not cause pyrexia, in fact arachidonic acid causes hypothermia. 4 Prior treatment with indomethacin (15 mg/kg) and paracetamol (50 mg/kg) specifically reverses the anorexia and the behavioural satiety induced by the three fatty acids, while not affecting prostaglandin F2alpha-induced suppression of food intake. 5 Results of the present experiments suggest that both physiological and pharmacological modification of appetite could be brought about through an effect on prostaglandin generating systems. PMID:890209

  18. Metabolism of 1alpha-hydroxyvitamin D3 by cytochrome P450scc to biologically active 1alpha,20-dihydroxyvitamin D3.

    PubMed

    Tuckey, Robert C; Janjetovic, Zorica; Li, Wei; Nguyen, Minh N; Zmijewski, Michal A; Zjawiony, Jordan; Slominski, Andrzej

    2008-12-01

    Cytochrome P450scc (CYP11A1) metabolizes vitamin D3 to 20-hydroxyvitamin D3 as the major product, with subsequent production of dihydroxy and trihydroxy derivatives. The aim of this study was to determine whether cytochrome P450scc could metabolize 1alpha-hydroxyvitamin D3 and whether products were biologically active. The major product of 1alpha-hydroxyvitamin D3 metabolism by P450scc was identified by mass spectrometry and NMR as 1alpha,20-dihydroxyvitamin D3. Mass spectrometry of minor metabolites revealed the production of another dihydroxyvitamin D3 derivative, two trihydroxy-metabolites made via 1alpha,20-dihydroxyvitamin D3 and a tetrahydroxyvitamin D3 derivative. The Km for 1alpha-hydroxyvitamin D3 determined for P450scc incorporated into phospholipid vesicles was 1.4 mol substrate/mol phospholipid, half that observed for vitamin D3. The kcat was 3.0 mol/min/mol P450scc, 6-fold lower than that for vitamin D3. 1alpha,20-Dihydroxyvitamin D3 inhibited DNA synthesis by human epidermal HaCaT keratinocytes propagated in culture, in a time- and dose-dependent fashion, with a potency similar to that of 1alpha,25-dihydroxyvitamin D3. 1alpha,20-Dihydroxyvitamin D3 (10 microM) enhanced CYP24 mRNA levels in HaCaT keratinocytes but the potency was much lower than that reported for 1alpha,25-dihydroxyvitamin D3. We conclude that the presence of the 1-hydroxyl group in vitamin D3 does not alter the major site of hydroxylation by P450scc which, as for vitamin D3, is at C20. The major product, 1alpha,20-dihydroxyvitamin D3, displays biological activity on keratinocytes and therefore might be useful pharmacologically. PMID:19000766

  19. Synthesis of prostaglandin E2, thromboxane B2 and prostaglandin catabolism in gastritis and gastric ulcer.

    PubMed Central

    Hawkey, C J

    1986-01-01

    Because endogenous prostaglandins may protect the gastric mucosa a study was conducted to determine factors influencing the synthesis of immunoreactive prostaglandin (iPG) E2 and thromboxane (iTx) B2 as measured by radioimmunoassay and prostaglandin catabolism measured radiometrically, in human gastric mucosa. Gastric mucosa was obtained at endoscopy. Synthesis of iPE2 and iTxB2 was inhibited in vitro by indomethacin; iTxB2 synthesis was also selectively inhibited by the thromboxane synthesis inhibitor dazmegrel. Prostaglandin catabolism was inhibited by carbenoxolone. Multivariate analysis showed that synthesis of iPGE2 from endogenous precursor during homogenisation was decreased in patients on non-steroidal anti-inflammatory drugs. Mucosal inflammation was associated with significantly increased synthesis of iPGE2 and decreased prostaglandin catabolism. There were no differences between the mucosa of patients with or without gastric ulcers, nor between the ulcer rim and mucosa 5 cm away. Age, sex, smoking history and ingestion of antisecretory drugs appeared to exert no influence. In this study gastritis was the major influence on prostaglandin synthesis. It seems unlikely that prostaglandin deficiency is a strong predisposing factor for gastric ulceration. PMID:3468053

  20. Transformation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by using Streptomyces sp. strains.

    PubMed Central

    Sasaki, J; Mikami, A; Mizoue, K; Omura, S

    1991-01-01

    To enzymatically synthesize vitamin D derivatives, we screened about 300 Streptomyces sp. strains. Streptomyces sclerotialus FERM BP-1370 and Streptomyces roseoporus FERM BP-1574 were found to have the ability to convert 25-hydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3, respectively, to 1 alpha, 25-dihydroxyvitamin D3. The average rates of 1 alpha hydroxylation of 25-hydroxyvitamin D3 were 6.9 micrograms liter-1 min-1 with FERM BP-1370 and 7.0 micrograms liter-1 min-1 with FERM BP-1574. The specific cytochrome P-450 inhibitors carbon monoxide, SKF-525-A, and metyrapone inhibited the hydroxylation of 1 alpha- and 25-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by FERM BP-1370 and FERM BP-1574. The cytochromes P-450 of these strains were detected by reduced CO difference spectra in the whole-cell suspensions. The appearance of cytochrome P-450 suggests that the cytochromes P-450 of FERM BP-1370 and FERM BP-1574 carry out the hydroxylation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3. PMID:1746944

  1. Importance of endogenous prostaglandins for the toxicity of cyclosporin A to rat endocrine and exocrine pancreas?

    PubMed Central

    Rünzi, M; Peskar, B M; von Schönfeld, J; Müller, M K

    1992-01-01

    Previous work has shown that cyclosporin A is toxic to the endocrine and exocrine pancreas. The aim of this study was to examine whether endogenous eicosanoids play a role in controlling cyclosporin A induced toxicity. Rats were treated for eight days with indomethacin (2 mg/kg, twice daily) in addition to cyclosporin A (5 or 10 mg/kg daily). Effects of drug treatments on exocrine (as assessed by amylase and protein secretion into the pancreatic juice) and endocrine (as assessed by the glucose dependent insulin release) pancreatic functions, and pancreatic formation of prostaglandins and thromboxane were evaluated. Treatment with cyclosporin A in the doses used did not inhibit eicosanoid formation by the pancreatic tissue ex vivo. Indomethacin caused significant inhibition of pancreatic formation of prostaglandin E2, 6k prostaglandin F1 alpha and thromboxane B2. Combined treatment with indomethacin and cyclosporin A (5 or 10 mg/kg) augmented cyclosporin A induced pancreatic toxicity with further impairment of insulin release, amylase secretion, and pancreatic juice protein content, but did not result in more pronounced inhibition of pancreatic eicosanoid formation. The increased toxicity of the combined treatment was, however, associated with raised cyclosporin A whole blood concentrations. The data suggest that the potentiation of pancreatic toxicity of cyclosporin A observed during coadministration of indomethacin is not the result of suppression of endogenous pancreatic eicosanoid biosynthesis, but more likely results from altered cyclosporin A pharmacokinetic which may be caused by an interference of indomethacin with the hepatic cytochrome P-450 dependent monooxygenase involved in cyclosporin A metabolism. The possibility that coadministration of non-steroidal antiinflammatory drugs aggravates toxic effects in cyclosporin A treated patients should be considered. PMID:1280611

  2. Crosstalk between the peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) and the vitamin D receptor (VDR) in human breast cancer cells: PPAR{gamma} binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} mediated transactivation

    SciTech Connect

    Alimirah, Fatouma; Peng, Xinjian; Yuan, Liang; Mehta, Rajeshwari R.; Knethen, Andreas von; Choubey, Divaker; Mehta, Rajendra G.

    2012-11-15

    Heterodimerization and cross-talk between nuclear hormone receptors often occurs. For example, estrogen receptor alpha (ER{alpha}) physically binds to peroxisome proliferator-activated receptor gamma (PPAR{gamma}) and inhibits its transcriptional activity. The interaction between PPAR{gamma} and the vitamin D receptor (VDR) however, is unknown. Here, we elucidate the molecular mechanisms linking PPAR{gamma} and VDR signaling, and for the first time we show that PPAR{gamma} physically associates with VDR in human breast cancer cells. We found that overexpression of PPAR{gamma} decreased 1{alpha},25-dihydroxyvitamin D{sub 3} (1,25D{sub 3}) mediated transcriptional activity of the vitamin D target gene, CYP24A1, by 49% and the activity of VDRE-luc, a vitamin D responsive reporter, by 75% in T47D human breast cancer cells. Deletion mutation experiments illustrated that helices 1 and 4 of PPAR{gamma}'s hinge and ligand binding domains, respectively, governed this suppressive function. Additionally, abrogation of PPAR{gamma}'s AF2 domain attenuated its repressive action on 1,25D{sub 3} transactivation, indicating that this domain is integral in inhibiting VDR signaling. PPAR{gamma} was also found to compete with VDR for their binding partner retinoid X receptor alpha (RXR{alpha}). Overexpression of RXR{alpha} blocked PPAR{gamma}'s suppressive effect on 1,25D{sub 3} action, enhancing VDR signaling. In conclusion, these observations uncover molecular mechanisms connecting the PPAR{gamma} and VDR pathways. -- Highlights: PPAR{gamma}'s role on 1{alpha},25-dihydroxyvitamin D{sub 3} transcriptional activity is examined. Black-Right-Pointing-Pointer PPAR{gamma} physically binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} action. Black-Right-Pointing-Pointer PPAR{gamma}'s hinge and ligand binding domains are important for this inhibitory effect. Black-Right-Pointing-Pointer PPAR{gamma} competes with VDR for the availability of their binding partner, RXR{alpha}.

  3. Desferrioxamine, an iron chelator, enhances HIF-1{alpha} accumulation via cyclooxygenase-2 signaling pathway

    SciTech Connect

    Woo, Kyung Jin; Lee, Tae-Jin; Park, Jong-Wook; Kwon, Taeg Kyu . E-mail: kwontk@dsmc.or.kr

    2006-04-28

    Cyclooxygenase-2 (COX-2) is an important inducible enzyme in inflammation and is overexpressed in a variety of cancers. Evidence is rapidly accumulating that chronic inflammation may contribute to carcinogenesis through increase of cell proliferation, angiogenesis, and metastasis in a number of neoplasms, including colorectal carcinoma. In the present study, we investigated some mechanistic aspects of DFX-induced hypoxia-driven COX-2 expression. Desferrioxamine (DFX), an iron chelator, is known to upregulate inflammatory mediators. DFX induced the expression of COX-2 and accumulation of HIF-1{alpha} protein in dose-dependent manners, but hypoxia mimetic agent cobalt chloride (CoCl{sub 2}) induced accumulation of HIF-1{alpha} protein but not increase of COX-2 expression. DFX-induced increase of COX-2 expression and HIF-1{alpha} protein level was attenuated by addition of ferric citrate. This result suggested that the iron chelating function of DFX was important to induce the increase of COX-2 and HIF-1{alpha} protein. PD98059 significantly inhibited the induction of COX-2 protein and accumulation of HIF-1{alpha}, suggesting that DFX-induced increase of HIF-1{alpha} and COX-2 protein was mediated, at least in part, through the ERK signaling pathway. In addition, pretreatment with NS-398 to inhibit COX-2 activity also effectively suppressed DFX-induced HIF-1{alpha} accumulation in human colon cancer cells, providing the evidence that COX-2 plays as a regulator of HIF-1{alpha} accumulation in DFX-treated colon cancer cells. Together, our findings suggest that iron metabolism may regulate stabilization of HIF-1{alpha} protein by modulating cyclooxygenase-2 signaling pathway.

  4. KNK437, abrogates hypoxia-induced radioresistance by dual targeting of the AKT and HIF-1{alpha} survival pathways

    SciTech Connect

    Oommen, Deepu; Prise, Kevin M.

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer KNK437, a benzylidene lactam compound, is a novel radiosensitizer. Black-Right-Pointing-Pointer KNK437 inhibits AKT signaling and abrogates the accumulation of HIF-1{alpha} under hypoxia. Black-Right-Pointing-Pointer KNK437 abrogates hypoxia induced resistance to radiation. -- Abstract: KNK437 is a benzylidene lactam compound known to inhibit stress-induced synthesis of heat shock proteins (HSPs). HSPs promote radioresistance and play a major role in stabilizing hypoxia inducible factor-1{alpha} (HIF-1{alpha}). HIF-1{alpha} is widely responsible for tumor resistance to radiation under hypoxic conditions. We hypothesized that KNK437 sensitizes cancer cells to radiation and overrides hypoxia-induced radioresistance via destabilizing HIF-1{alpha}. Treatment of human cancer cells MDA-MB-231 and T98G with KNK437 sensitized them to ionizing radiation (IR). Surprisingly, IR did not induce HSPs in these cell lines. As hypothesized, KNK437 abrogated the accumulation of HIF-1{alpha} in hypoxic cells. However, there was no induction of HSPs under hypoxic conditions. Moreover, the proteosome inhibitor MG132 did not restore HIF-1{alpha} levels in KNK437-treated cells. This suggested that the absence of HIF-1{alpha} in hypoxic cells was not due to the enhanced protein degradation. HIF-1{alpha} is mainly regulated at the level of post-transcription and AKT is known to modulate the translation of HIF-1{alpha} mRNA. Interestingly, pre-treatment of cells with KNK437 inhibited AKT signaling. Furthermore, down regulation of AKT by siRNA abrogated HIF-1{alpha} levels under hypoxia. Interestingly, KNK437 reduced cell survival in hypoxic conditions and inhibited hypoxia-induced resistance to radiation. Taken together, these data suggest that KNK437 is an effective radiosensitizer that targets multiple pro-survival stress response pathways.

  5. Identification of high-affinity anti-IL-1. alpha. autoantibodies in normal human serum as an interfering substance in a sensitive enzyme-linked immunosorbent assay for IL-1. alpha

    SciTech Connect

    Mae, N.; Liberato, D.J.; Chizzonite, R.; Satoh, H. )

    1991-04-01

    A highly reproducible, sensitive, and specific sandwich enzyme-linked immunosorbent assay (ELISA) for recombinant human IL-1 {alpha} (rhIL-1 alpha) has been developed. Results from this ELISA have demonstrated that the concentration of rhIL-1 {alpha} added to normal human serum (NHS) decreased by 16.3% after 3 h and 24.9% after 6 h at room temperature. Molecular exclusion column chromatography with Sephacryl S-300 HR revealed that 125I-labeled IL-1 {alpha} added to normal human serum rapidly formed higher molecular weight complexes without indication of proteolytic degradation. The observed reduction in immunoreactivity was correlated with this protein complex formation and accounted for the apparent instability of rhIL-1 {alpha} in NHS. Immunoblot analysis indicated that the molecular weight of the binding protein was 150-160K, and the IL-1 {alpha} binding activity was removed and recovered from NHS by Protein-G affinity chromatography; indicating that the binding protein was IL-1 {alpha}-specific IgG. The binding of 125I-labeled IL-1 {alpha} to the serum binding proteins could be inhibited by unlabeled IL-1 alpha (IC50 = 7.4 {times} 10(-11) M) but not by unlabeled IL-1 {beta}. Kinetic analysis with 125I-labeled IL-1 alpha revealed that the average binding affinity of these IL-1 {alpha}-specific IgGs was 4.7 {times} 10(10) M-1. These results suggest that these autoantibodies may interfere with the detection of IL-1 {alpha} in human serum by various assay systems and also could be a regulator of circulating IL-1 {alpha}.

  6. NF-{kappa}B suppresses HIF-1{alpha} response by competing for P300 binding

    SciTech Connect

    Mendonca, Daniela B.S.; Mendonca, Gustavo; Aragao, Francisco J.L.; Cooper, Lyndon F.

    2011-01-28

    Research highlights: {yields} p65 completely blocked HIF-1{alpha} activity at the HRE on different cell lines. {yields} p65 caused minor changes in HIF-1{alpha} and HIF-1{alpha} target genes mRNA expression. {yields} p65 reduced transcription of VEGF promoter. {yields} p65 competes with HIF-1{alpha} for p300. -- Abstract: Hypoxia has emerged as a key determinant of osteogenesis. HIF-1{alpha} is the transcription factor mediating hypoxia responses that include induction of VEGF and related bone induction. Inflammatory signals antagonize bone repair via the NF-{kappa}B pathway. The present investigation explored the functional relationship of hypoxia (HIF-1{alpha} function) and inflammatory signaling (NF-{kappa}B) in stem like and osteoprogenitor cell lines. The potential interaction between HIF-1{alpha} and NF-{kappa}B signaling was explored by co-transfection studies in hFOB with p65, HIF-1{alpha} and 9x-HRE-luc or HIF-1{alpha} target genes reporter plasmids. Nuclear cross-talk was directly tested using the mammalian Gal4/VP16 two-hybrid, and confirmed by co-immunoprecipitation/western blotting assays. The results show that inflammatory stimulation (TNF-{alpha} treatment) causes a marked inhibition of HIF-1{alpha} function at the HRE in all cell lines studied. Also, co-transfection with p65 expression vector leads to reduced hVEGFp transcription after DFO-induced hypoxia. However, TNF-{alpha} treatment had little effect on HIF-1{alpha} mRNA levels. The functional interaction of Gal4-HIF-1{alpha} and VP16-p300 fusion proteins is effectively blocked by expression of p65 in a dose dependent manner. It was concluded that NF-{kappa}B-mediated inflammatory signaling is able to block HIF-1{alpha} transactivation at HRE-encoding genes by direct competition for p300 binding at the promoter. Inflammation may influence the stem cell niche and tissue regeneration by influencing cellular responses to hypoxia.

  7. Effects of Common Pesticides on Prostaglandin D2 (PGD2) Inhibition in SC5 Mouse Sertoli Cells, Evidence of Binding at the COX-2 Active Site, and Implications for Endocrine Disruption

    PubMed Central

    Kugathas, Subramaniam; Audouze, Karine; Ermler, Sibylle; Orton, Frances; Rosivatz, Erika; Scholze, Martin; Kortenkamp, Andreas

    2015-01-01

    . Citation: Kugathas S, Audouze K, Ermler S, Orton F, Rosivatz E, Scholze M, Kortenkamp A. 2016. Effects of common pesticides on prostaglandin D2 (PGD2) inhibition in SC5 mouse Sertoli cells, evidence of binding at the COX-2 active site, and implications for endocrine disruption. Environ Health Perspect 124:452–459; http://dx.doi.org/10.1289/ehp.1409544 PMID:26359731

  8. P70S6K 1 regulation of angiogenesis through VEGF and HIF-1{alpha} expression

    SciTech Connect

    Bian, Chuan-Xiu; Shi, Zhumei; Meng, Qiao; Jiang, Yue; Liu, Ling-Zhi; Jiang, Bing-Hua

    2010-07-30

    Research highlights: {yields} P70S6K1 regulates VEGF expression; {yields} P70S6K1 induces transcriptional activation through HIF-1{alpha} binding site; {yields} P70S6K1 regulates HIF-1{alpha}, but not HIF-1{beta} protein expression; {yields} P70S6K1 mediates tumor growth and angiogenesis through HIF-1{alpha} and VEGF expression. -- Abstract: The 70 kDa ribosomal S6 kinase 1 (p70S6K1), a downstream target of phosphoinositide 3-kinase (PI3K) and ERK mitogen-activated protein kinase (MAPK), is an important regulator of cell cycle progression, and cell proliferation. Recent studies indicated an important role of p70S6K1 in PTEN-negative and AKT-overexpressing tumors. However, the mechanism of p70S6K1 in tumor angiogenesis remains to be elucidated. In this study, we specifically inhibited p70S6K1 activity in ovarian cancer cells using vector-based small interfering RNA (siRNA) against p70S6K1. We found that knockdown of p70S6K1 significantly decreased VEGF protein expression and VEGF transcriptional activation through the HIF-1{alpha} binding site at its enhancer region. The expression of p70S6K1 siRNA specifically inhibited HIF-1{alpha}, but not HIF-1{beta} protein expression. We also found that p70S6K1 down-regulation inhibited ovarian tumor growth and angiogenesis, and decreased cell proliferation and levels of VEGF and HIF-1{alpha} expression in tumor tissues. Our results suggest that p70S6K1 is required for tumor growth and angiogenesis through HIF-1{alpha} and VEGF expression, providing a molecular mechanism of human ovarian cancer mediated by p70S6K1 signaling.

  9. Inhibition of experimental autoimmune tubulointerstitial nephritis in Brown-Norway rats by (15S)-15-methyl prostaglandin E1. Analysis of the effect of prostaglandin E1 on the induction of the humoral immune response and the elicitation of humorally mediated inflammation.

    PubMed Central

    Ulich, T. R.; Ni, R. X.

    1986-01-01

    Brown-Norway (BN) rats develop tubulointerstitial nephritis (TIN) after immunization with bovine tubular basement membrane (TBM) and adjuvants. Daily subcutaneous injections (either on Days 0-7 or Days 0-14) of (15S)-15-methyl prostaglandin E1 (M-PGE1) at a dose of 1 mg/kg/day markedly inhibited or completely abrogated the development of both the acute polymorphonuclear (Day 10) and the subsequent mononuclear (Day 14) inflammatory phases of BN rat TIN. Circulating anti-TBM antibody in Days 0-7 M-PGE1-treated rats was moderately diminished on Day 8 after immunization but not on Day 14. Circulating anti-TBM antibody in Days 0-14 M-PGE1-treated rats was only slightly diminished on Day 14. In experiments to test the effect of M-PGE1 on the elicitation phase of humorally mediated inflammation, M-PGE1 inhibited the acute inflammatory response observed 6 hours after intradermal injection of particulate TBM into TBM-sensitized BN rats. The inflammation in these skin tests was demonstrated by passive transfer experiments to be humorally mediated. The inhibition of acute humorally mediated intradermal inflammation was not attributable to neutropenia, because M-PGE1 caused a significant neutrophilia as demonstrated by peripheral blood smears. Although the inhibition of TIN in Days 0-14 M-PGE1-treated rats may have been due, in part, to dysfunction of the elicitation phase of humorally mediated inflammation, the inhibition of TIN in Days 0-7 M-PGE1-treated rats was more likely secondary to the diminished induction of either humoral or cellular immunity. Images Figure 5 Figure 6 Figure 7 PMID:3740216

  10. Effects of 12 metal ions on iron regulatory protein 1 (IRP-1) and hypoxia-inducible factor-1 alpha (HIF-1{alpha}) and HIF-regulated genes

    SciTech Connect

    Li Qin; Chen Haobin; Huang Xi; Costa, Max . E-mail: costam@env.med.nyu.edu

    2006-06-15

    significant stabilization and elevation of HIF-1{alpha} protein which drives these other parameters was previously shown by us and others to involve a loss of cellular Fe as well as inhibition of HIF-1{alpha}-dependent prolyl hydroxylases which target the binding of VHL ubiquitin ligase and degrade HIF-1{alpha}. Even though there were small effects of some of the other metals on IRP and HIF-1{alpha}, downstream effects of HIF-1{alpha} activation and therefore robust hypoxia signaling were only observed with Ni(II), Co(II), and to much lesser extents with Mn(II) and V(V) in human A549 lung cells. It is of interest that the metal ions that were most effective in activating hypoxia signaling were the ones that were poor inducers of metallothionein protein and also decreased Ferritin levels, since both of these proteins can bind metal ions and protect the cell against toxicity in human lung cells. It is important to study effects of these metals in human lung cells since this represents a major route of human environmental and occupational exposure to these metal ions.

  11. The inhibitory effect of dexamethasone on platelet-derived growth factor-induced vascular smooth muscle cell migration through up-regulating PGC-1{alpha} expression

    SciTech Connect

    Xu, Wei; Guo, Ting; Zhang, Yan; Jiang, Xiaohong; Zhang, Yongxian; Zen, Ke; Yu, Bo; Zhang, Chen-Yu

    2011-05-01

    Dexamethasone has been shown to inhibit vascular smooth muscle cell (VSMC) migration, which is required for preventing restenosis. However, the mechanism underlying effect of dexamethasone remains unknown. We have previously demonstrated that peroxisome proliferator-activated receptor gamma (PPAR{gamma}) coactivator-1 alpha (PGC-1{alpha}) can inhibit VSMC migration and proliferation. Here, we investigated the role of PGC-1{alpha} in dexamethasone-reduced VSMC migration and explored the possible mechanism. We first examined PGC-1{alpha} expression in cultured rat aortic VSMCs. The results revealed that incubation of VSMCs with dexamethasone could significantly elevate PGC-1{alpha} mRNA expression. In contrast, platelet-derived growth factor (PDGF) decreased PGC-1{alpha} expression while stimulating VSMC migration. Mechanistic study showed that suppression of PGC-1{alpha} by small interfering RNA strongly abrogated the inhibitory effect of dexamethasone on VSMC migration, whereas overexpression of PGC-1{alpha} had the opposite effect. Furthermore, an analysis of MAPK signal pathways showed that dexamethasone inhibited ERK and p38 MAPK phosphorylation in VSMCs. Overexpression of PGC-1{alpha} decreased both basal and PDGF-induced p38 MAPK phosphorylation, but it had no effect on ERK phosphorylation. Finally, inhibition of PPAR{gamma} activation by a PPAR{gamma} antagonist GW9662 abolished the suppressive effects of PGC-1{alpha} on p38 MAPK phosphorylation and VSMC migration. These effects of PGC-1{alpha} were enhanced by a PPAR{gamma} agonist troglitazone. Collectively, our data indicated for the first time that one of the anti-migrated mechanisms of dexamethasone is due to the induction of PGC-1{alpha} expression. PGC-1{alpha} suppresses PDGF-induced VSMC migration through PPAR{gamma} coactivation and, consequently, p38 MAPK inhibition.

  12. Effect of chronic alcohol consumption on Hepatic SIRT1 and PGC-1{alpha} in rats

    SciTech Connect

    Lieber, Charles S. Leo, Maria A.; Wang Xiaolei; DeCarli, Leonore M.

    2008-05-23

    The nuclear genes, NAD-dependent deacetylase Sirtuis 1 (SIRT1) and the peroxisome proliferator-activated receptor-{gamma} coactivator1{alpha} (PGC-1{alpha}) are regulators of energy metabolism. Here, we studied the role of alcohol consumption in expression of these sensing molecules. Alcohol significantly reduced hepatic SIRT1 mRNA by 50% and PGC-1{alpha} mRNA by 46% and it significantly inhibited the protein expression of SIRT1 and PGC-1{alpha}, while the transcription factor PPAR-{gamma} remained unchanged. However, when the lipid composition of the alcohol diet was changed by replacing long-chain triglycerides (LCT) with medium chain triglycerides (MCT), SIRT1 and PGC-1{alpha} mRNA were restored to near control levels. This study demonstrates that alcohol reduces key energy sensing proteins and that replacement of LCT by MCT affects the transcription of these genes. Since there is a pathophysiological link between SIRT1 and PGC-1{alpha} and mitochondrial energy, the implication of the study is that mitochondrial dysfunction due to alcohol abuse can be treated by dietary modifications.

  13. Whole-body irradiation transiently diminishes the adrenocorticotropin response to recombinant human interleukin-1{alpha}

    SciTech Connect

    Perlstein, R.S.; Mehta, N.R.; Neta, R.; Whitnall, M.H.; Mougey, E.H.

    1995-03-01

    Recombinant human interleukin-1{alpha} (rhIL-1{alpha}) has significant potential as a radioprotector and/or treatment for radiation-induced hematopoietic injury. Both IL-1 and whole-body ionizing irradiation acutely stimulate the hypothalamic-pituitary-adrenal axis. We therefore assessed the interaction of whole-body irradiation and rhIL-1{alpha} in altering the functioning of the axis in mice. Specifically, we determined the adrenocorticotropin (ACTH) and corticosterone responses to rhIL-1{alpha} administered just before and hours to days after whole-body or sham irradiation. Our results indicate that whole-body irradiation does not potentiate the rhIL-1{alpha}-induced increase in ACTH levels at the doses used. In fact, the rhIL-1{alpha}-induced increase in plasma ACTH is transiently impaired when the cytokine is administered 5 h after, but not 1 h before, exposure to whole-body irradiation. The ACTH response may be inhibited by elevated corticosterone levels after whole-body irradiation, or by other radiation-induced effects on the pituitary gland and hypothalamus. 36 refs., 3 figs.

  14. Regulation of prostaglandin production by nitric oxide; an in vivo analysis.

    PubMed Central

    Salvemini, D; Settle, S L; Masferrer, J L; Seibert, K; Currie, M G; Needleman, P

    1995-01-01

    1. Endotoxin E. Coli lipopolysaccharide (LPS)-treatment in conscious, restrained rats increased plasma and urinary prostaglandin (PG) and nitric oxide (NO) production. Inducible cyclo-oxygenase (COX-2) and nitric oxide synthase (iNOS) expression accounted for the LPS-induced PG and NO release since the glucocorticoid, dexamethasone inhibited both effects. Thus, LPS (4 mg kg-1) increased the plasma levels of nitrite/nitrate from 14 +/- 1 to 84 +/- 7 microM within 3 h and this rise was inhibited to 35 +/- 1 microM by dexamethasone. Levels of 6-keto PGF1 alpha in the plasma were below the detection limit of the assay (< 0.2 ng ml-1). However, 3 h after the injection of LPS these levels rose to 2.6 +/- 0.2 ng ml-1 and to 0.7 +/- 0.01 ng ml-1 after LPS in rats that received dexamethasone. 2. The induced enzymes were inhibited in vivo with selective COX and NOS inhibitors. Furthermore, NOS inhibitors, that did not affect COX activity in vitro markedly suppressed PG production in the LPS-treated animals. For instance, the LPS-induced increased in plasma nitrite/nitrate and 6-keto PGF1 alpha at 3 h was decreased to 18 +/- 2 microM and 0.5 +/- 0.02 ng ml-1, 23 +/- 1 microM and 0.7 +/- 0.01 ng ml-1, 29 +/- 2 microM and 1 +/- 0.01 ng ml-1 in rats treated with LPS in the presence of the NOS inhibitors NG-monomethyl-L-arginine, NG-nitro arginine methyl ester and aminoguanidine, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7542531

  15. Prostaglandin synthesis in aorta of atherosclerosis susceptible and atherosclerosis resistant pigeons.

    PubMed

    Subbiah, M T; Schweiger, E; Deitmeyer, D; Gallon, L; Sinzinger, H

    1980-01-01

    The aortas of 9 months aged Show Racer and White Carneau pigeons were examined for their PGE2, PGF2 alpha and 6-keto-PGF1 alpha synthesis from labelled arachidonic acid by radiothinlayer chromatography. The prostacyclin formation was estimated by means of Moncada's bioassay. PGE2 and PGF 2 alpha synthesis in the aorta of pigeons is higher than in rats, whereas less 6-keto-PGF1 alpha is formed in pigeon aortas. The susceptible White Carneau pigeons synthesitize more prostaglandins than the resistant Show Racer pigeons. PGI2 and 6-keto-PGF 1 alpha-formation is extremely low in avian arota. These data are in part contradicting to our findings im mammalians (where the atherosclerosis susceptible animals generate less PGI2) and warrants sequential measurements of prostaglandin synthesis in aorta to assess its significance during various stages of atherogenesis. PMID:7425865

  16. Prostaglandins and prostaglandin receptor antagonism in migraine.

    PubMed

    Antonova, Maria

    2013-05-01

    Human models of headache may contribute to understanding of prostaglandins' role in migraine pathogenesis. The current thesis investigated the migraine triggering effect of prostaglandin E2 (PGE2) in migraine patients without aura, the efficacy of a novel EP4 receptor antagonist, BGC20-1531, in prevention of PGE2-induced headache and the ability of prostaglandin F2α (PGF2α) to trigger headache without any vasodilatation in healthy volunteers. All studies were designed as double-blind, placebo-controlled, cross-over experiments, where PGE2/PGF2α or saline were infused over 20-25 min. In the study with EP4 receptor antagonist healthy volunteers were pre-treated with two different doses of BGC20-1531 or placebo followed by PGE2 infusion over 25 min. The headache data were collected during the whole study day, whereas the possible vascular changes were measured during the in-hospital phase of 1.5 h. The infusion of PGE2 caused the immediate migraine-like attacks and vasodilatation of the middle cerebral artery in migraine patients without aura. The highly specific and potent EP4 receptor antagonist, BGC20-1531, was not able to attenuate PGE2-induced headache and vasodilatation of both intra- and extra-cerebral arteries. The intravenous infusion of PGF2α did not induce headache or statistically significant vasoconstriction of cerebral arteries in healthy volunteers. Novel data on PGE2-provoked immediate migraine-like attacks suggest that PGE2 may be one of the important final products in the pathogenesis of migraine. The lack of efficacy of EP4 receptor antagonist suggests that a single receptor blockade is not sufficient to block PGE2 responses, hence EP2 receptor should be investigated as a potential drug target for the treatment of migraine. The absence of headache during the PGF2α infusion demonstrates that vasodilating properties are necessary for the induction of headache and migraine. PMID:23673269

  17. Effects of prostaglandin E2, cholera toxin and 8-bromo-cyclic AMP on lipopolysaccharide-induced gene expression of cytokines in human macrophages.

    PubMed Central

    Zhong, W W; Burke, P A; Drotar, M E; Chavali, S R; Forse, R A

    1995-01-01

    Prostaglandin E2 (PGE2) appears to regulate macrophage cytokine production through the stimulatory GTP-binding protein (Gs protein)-mediated cyclic AMP (cAMP)-dependent transmembrane signal transduction pathway. In this study, we used PGE2, cholera toxin (CT; a direct G alpha s protein stimulator) and 8-bromo-cAMP (a membrane permeable cAMP analogue) to stimulate this pathway, and investigated their influence on cytokine gene expression in lipopolysaccharide (LPS)-activated human macrophages. The mRNA expression for interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 were determined employing reverse transcription polymerase chain reaction (RT-PCR) using specific primers. We demonstrated that PGE2, CT and 8-bromo-cAMP inhibited the LPS-induced gene activation of TNF-alpha and IL-1 alpha, and had no effect on the gene activation of IL-1 beta and IL-8. Further, our data indicate that PGE2 suppressed the gene activation of IL-6 following LPS stimulation, but neither CT nor 8-bromo-cAMP had an effect. These data suggest that PGE2 alters LPS-stimulated gene activation of only some of the early macrophage cytokines, and does so either by a Gs transmembrane cAMP-dependent or an independent system. Images Figure 1 PMID:7751029

  18. Loss of high-affinity prostacyclin receptors in platelets and the lack of prostaglandin-induced inhibition of platelet-stimulated thrombin generation in subjects with spinal cord injury.

    PubMed Central

    Kahn, N N; Bauman, W A; Sinha, A K

    1996-01-01

    Coronary artery disease is a leading cause of death in individuals with chronic spinal cord injury (SCI). However, platelets of those with SCI (n = 30) showed neither increased aggregation nor resistance to the antiaggregatory effects of prostacyclin when compared with normal controls (n = 30). Prostanoid-induced cAMP synthesis was similar in both groups. In contrast, prostacyclin, which completely inhibited the platelet-stimulated thrombin generation in normal controls, failed to do so in those with SCI. Scatchard analysis of the binding of [3H]prostaglandin E1, used as a prostacyclin receptor probe, showed the presence of one high-affinity (Kd1 = 8.11 +/- 2.80 nM; n1 = 172 +/- 32 sites per cell) and one low-affinity (Kd2 = 1.01 +/- 0.3 microM; n2 = 1772 +/- 226 sites per cell) prostacyclin receptor in normal platelets. In contrast, the same analysis in subjects with SCI showed significant loss (P < 0.001) of high-affinity receptor sites (Kd1 = 6.34 +/- 1.91 nM; n1 = 43 +/- 10 sites per cell) with no significant change in the low affinity-receptors (Kd2 = 1.22 +/- 0.23; n2 = 1820 +/- 421). Treatment of these platelets with insulin, which has been demonstrated to restore both of the high- and low-affinity prostaglandin receptor numbers to within normal ranges in coronary artery disease, increased high-affinity receptor numbers and restored the prostacyclin effect on thrombin generation. These results demonstrate that the loss of the inhibitory effect of prostacyclin on the stimulation of thrombin generation was due to the loss of platelet high-affinity prostanoid receptors, which may contribute to atherogenesis in individuals with chronic SCI. PMID:8552614

  19. Potentiation of mitomycin C and porfiromycin antitumor activity in solid tumor models by recombinant human interleukin 1 alpha.

    PubMed

    Braunschweiger, P G; Jones, S A; Johnson, C S; Furmanski, P

    1991-10-15

    The time- and dose-dependent effects of recombinant human interleukin 1 alpha (IL-1 alpha) on the antitumor activity of mitomycin C (MMC) and porfiromycin (PORF) were studied in RIF-1 and Panc02 solid tumor model systems. IL-1 alpha produced dose-dependent sensitization of clonogenic RIF-1 tumor cells to MMC in vivo. IL-1 alpha chemosensitization was highly schedule dependent, and the most efficacious schedules produced dose-modifying factors of 3.6 and 5.1 for MMC and PORF, respectively. More than additive clonogenic cell kill after IL-1 alpha-chemotherapy combinations reflected increased cellular sensitivity to MMC and PORF. The combinations also produced marked decreases in the yield of viable tumor cells, suggesting that the bioreductive drugs may have also potentiated the microvascular injury and ischemia produced by IL-1 alpha. Dexamethasone inhibited and ketoconazole, an inhibitor of corticosterone biosynthesis, enhanced IL-1 alpha-mediated chemosensitization in these models. IL-1 alpha mediated chemosensitization to MMC, and PORF was also demonstrated by tumor growth inhibition in the RIF-1 model and increased survival of mice in the spontaneously metastasizing Panc02 system. Chemosensitization of bone marrow spleen colony-forming units was not seen. IL-1 alpha (1000 units/ml) had no effect on MMC and PORF cytotoxicity in RIF-1 and PORF cell lines in vitro. The results indicate that the tumor-specific IL-1 alpha-induced pathophysiologies can sensitize solid tumors to agents which are preferentially activated, retained, and cytotoxic to cells under hypoxic conditions. Our results suggest that strategies combining bioreductively activated hypoxic cell cytotoxins and biological agents might offer efficacious alternatives or adjuvants to conventional combination approaches. PMID:1913664

  20. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death

    PubMed Central

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  1. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death.

    PubMed

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  2. Prostaglandin E2 inhibits IL-23 and IL-12 production by human monocytes through down-regulation of their common p40 subunit.

    PubMed

    Kalim, Khalid W; Groettrup, Marcus

    2013-03-01

    The heterodimeric cytokine IL-23 is important for the maintenance of Th17 cells, which are pivotal mediators of autoimmune diseases like rheumatoid arthritis, colitis, and multiple sclerosis. Prostaglandin E2 (PGE2) is a soluble regulator of inflammation that has both pro- and anti-inflammatory properties. PGE2 has been shown to elevate the IL-23 production by dendritic cells (DC). Monocytes are also producers of IL-23 but the effect of PGE2 on IL-23 production by human monocytes has hardly been investigated. We show here that PGE2 blocks the production of IL-23 by LPS-stimulated monocytes in an IL-10 and IL-1β independent manner. This effect was due to the down-regulation of the p40 subunit of IL-23 on mRNA and protein level. The p40 subunit is shared by IL-12 and, consistently, PGE2 also lowered the IL-12 production by monocytes. These effects of PGE2 were cAMP-dependent since the cAMP enhancer forskolin strongly reduced IL-23 and IL-12 production by monocytes. Taken together, PGE2 acts in an anti-inflammatory manner by lowering IL-23 production by monocytes while it has the opposite effect in DC. Our data may help to reconcile controversial point of views on the pro- and anti-inflammatory nature of PGE2 by making a strong case for a cell type-dependent function. PMID:22982753

  3. Prostaglandin A1 inhibits avian influenza virus replication at a postentry level: Effect on virus protein synthesis and NF-κB activity.

    PubMed

    Carta, Stefania; La Frazia, Simone; Donatelli, Isabella; Puzelli, Simona; Rossi, Antonio; Santoro, M Gabriella

    2014-12-01

    Influenza A viruses (IAV) have the potential to cause devastating pandemics. In recent years, the emergence of new avian strains able to infect humans represents a serious threat to global human health. The increase in drug-resistant IAV strains underscores the need for novel approaches to anti-influenza chemotherapy. Herein we show that prostaglandin-A1 (PGA1) possesses antiviral activity against avian IAV, including H5N9, H7N1 and H1N1 strains, acting at a level different from the currently available anti-influenza drugs. PGA1 acts at postentry level, causing dysregulation of viral protein synthesis and preventing virus-induced disassembly of host microtubular network and activation of pro-inflammatory factor NF-κB. The antiviral activity is dependent on the presence of a cyclopentenone ring structure and is associated with activation of a cytoprotective heat shock response in infected cells. The results suggest that cyclopentenone prostanoids or prostanoids-derived molecules may represent a new tool to combat avian influenza virus infection. PMID:25151089

  4. The effects of 1alpha,24(S)-dihydroxyvitamin D(2) analog on cancer cell proliferation and cytokine expression.

    PubMed

    Shany, S; Levy, Y; Lahav-Cohen, M

    2001-01-01

    It is well established that 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)), the active metabolite of vitamin D, plays a role in regulating proliferation and differentiation of cells, in addition to its classic function in mineral homeostasis. Recent studies have also provided evidence for the involvement of 1alpha,25(OH)(2)D(3) in regulating the immune system. However, therapeutic application of 1alpha,25(OH)(2)D(3) to hyperproliferative diseases such as cancer, or for immunologic purposes, is thwarted by its hypercalcemic activity. In order to overcome this obstacle, analogs of 1alpha,25(OH)(2)D(3) have been produced that exhibit decreased hypercalcemic activity while retaining the growth and immunologic regulating properties. In the present study, the efficacy of 1alpha,24(S)-dihydroxyvitamin D(2) (1alpha,24(S)(OH)(2)D(2)), a vitamin D(2) analog, in restraining cell proliferation was compared to that of 1alpha,25(OH)(2)D(3). In parallel studies, cancer cell lines were grown in increased concentrations (10(-10)-10(-7) M) of each compound for various incubation periods (1-4 days). Growth was assessed by measuring [(3)H]thymidine incorporation. The results revealed that 1alpha,24(S)(OH)(2)D(2) significantly inhibits proliferation to an extent similar to that observed for 1alpha,25(OH)(2)D(3). Moreover, incubating the human leukemia cell line, HL-60, with 1alpha,24(S)(OH)(2)D(2) resulted in an induction of differentiation of these promyelomonocyte cells into monocyte-macrophage-like cells, in a manner similar to that observed with 1alpha,25(OH)(2)D(3). Using a Western procedure, it was also shown that 1alpha,24(S)(OH)(2)D(2) like 1alpha,25(OH)(2)D(3) enhances the expression of vitamin D receptors (VDR) in the rat osteosarcoma cell line, ROS 17/2.8. The expression of tumor necrosis factor (TNF) alpha (TNF-alpha) in human peritoneal macrophages (HPM) obtained from uremic patients treated with continuous ambulatory peritoneal dialysis (CAPD) was found to be

  5. Atrial natriuretic peptide(31-67) inhibits Na+ transport in rabbit inner medullary collecting duct cells. Role of prostaglandin E2.

    PubMed Central

    Gunning, M E; Brady, H R; Otuechere, G; Brenner, B M; Zeidel, M L

    1992-01-01

    Atrial natriuretic peptide (ANP)(31-67), a portion of the atrial peptide prohormone, circulates in humans, and its plasma level varies with atrial pressure. Like the more widely studied carboxy-terminal fragment ANP(99-126), ANP(31-67) stimulates natriuresis and diuresis. We examined the mechanism of this natriuresis by measuring the effects of ANP(31-67) on Na+ transport in cells of the rabbit inner medullary collecting duct (IMCD). ANP(31-67) (10(-8) M) caused a 26 +/- 4% inhibition of oxygen consumption (QO2); half-maximal inhibition occurred at 10(-11) M, suggesting a physiologic effect. This effect was not additive with either ouabain or amiloride, suggesting that it reflected inhibition of Na+ transport-dependent QO2. ANP(31-67) reduced the amphotericin-induced stimulation of QO2 consistent with inhibition by this peptide of the Na(+)-K(+)-ATPase. In addition, ANP(31-67) reduced ouabain-sensitive 86Rb+ uptake under Vmax conditions. Several lines of evidence indicated that PGE2, a known endogenous IMCD Na(+)-K(+)-ATPase inhibitor, mediates pump inhibition by ANP(31-67). Thus, ANP(31-67) inhibits Na+ transport by inhibiting the Na(+)-K(+)-ATPase of IMCD cells, an effect mediated by the generation of PGE2. PMID:1533229

  6. Molecular cloning and characterization of the Xenopus hypoxia-inducible factor 1alpha (xHIF1alpha).

    PubMed

    de Beaucourt, Arnaud; Coumailleau, Pascal

    2007-12-15

    We report the molecular cloning and the characterization of the Xenopus homolog of mammalian hypoxia-inducible factor 1alpha (HIF1alpha), a member of the bHLH/PAS transcription factor family. Searches in Xenopus genome sequences and phylogenetic analysis reveal the existence of HIF1alpha and HIF2alpha paralogs in the Xenopus laevis species. Sequence data analyses indicate that the organization of protein domains in Xenopus HIF1alpha (xHIF1alpha) is strongly conserved. We also show that xHIF1alpha heterodimerizes with the Xenopus Arnt1 protein (xArnt1) with the proteic complex being mediated by the HLH and PAS domains. Subcellular analysis in a Xenopus XTC cell line using chimeric GFP constructs show that over-expression of xHIF1alpha and xArnt1 allows us to detect the xHIF1alpha/xArnt1 complex in the nucleus, but only in the presence of both partners. Further analyses in XTC cell line show that over-producing xHIF1alpha and xArnt1 mediates trans-activation of the hypoxia response element (HRE) reporter. The trans-activation level can be increased in hypoxia conditions. Interestingly such trans-activation properties can be also observed when human Arnt1 is used together with the xHIF1alpha. PMID:17471499

  7. Study on CXCR4/SDF-1alpha axis in lymph node metastasis of cervical squamous cell carcinoma.

    PubMed

    Zhang, J-P; Lu, W-G; Ye, F; Chen, H-Z; Zhou, C-Y; Xie, X

    2007-01-01

    CXCR4/stromal-cell-derived factor-1alpha (SDF-1alpha) is involved in many cancer metastatic mechanisms. Cervical squamous cell cancer (SCC) tissues (n=35), normal cervical tissues (n=10), metastatic (n=10) and nonmetastatic lymph nodes (n=50), and Hela cells were stained immunohistochemically with CXCR4 monoclonal antibody (mAb). Meanwhile, lymph nodes were stained immunohistochemically with rabbit anti-SDF-1alpha. In vitro invasion of Hela cells was evaluated using Transwell Permeable Supports (Corning, NY), in which Hela cells with/without CXCR4 mAb preincubation were seeded in the upper chambers and medium containing 0-100 ng/mL SDF-1alpha was added to the lower compartments. For evaluating the effect of CXCR4/SDF-1alpha on proliferation of cervical cancer cells, Hela cells were cultured for 72 h exposed to SDF-1alpha with and without CXCR4 mAb. We found that CXCR4 was expressed on SCC cells in all cervical cancer, metastatic lymph node, and Hela cells but not in normal cervix. SDF-1alpha was expressed on lymph cells in all lymph nodes. SDF-1alpha induced the directed migration of Hela cells with a concentration-dependent model, which was inhibited by CXCR4 mAb (P<0.05). SDF-1alpha also stimulated the proliferation of Hela cells mediated by CXCR4 (P<0.05). CXCR4/SDF-1alpha axis probably participates in the metastasis toward lymph nodes in cervical cancer. PMID:17362322

  8. Histamine stimulation of prostaglandin and HETE synthesis in human endothelial cells

    SciTech Connect

    Revtyak, G.E.; Hughes, M.J.; Johnson, A.R.; Campbell, W.B.

    1988-08-01

    Endothelial cells (EC) cultured from human umbilical artery (UA) and vein (UV) metabolized (/sup 14/C)arachidonic acid to prostaglandins (PGs), monohydroxyeicosatetraenoic acids (HETEs), and epoxyeicosatrienoic acids (EETs). Major radioactive products were identified as 6-keto-PGF1 alpha, PGE2, PGF2 alpha, 12-hydroxy heptadecatrienoic acid, 15-HETE, and 11-HETE. In addition, extracts from UV ECs contained 12-HETE, 5-HETE, 14,15-EET, and 5,6-EET as minor products, whereas extracts from UA ECs contained only 12-HETE as a minor product. UA ECs also produced metabolites comigrating with 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET. Histamine increased the release of (/sup 14/C)PGs and (/sup 14/C)HETEs from (/sup 14/C)arachidonic acid-labeled ECs. Indomethacin, aspirin, and nordihydroguauretic acid completely inhibited synthesis of both (/sup 14/C)PGs and (/sup 14/C)HETEs from exogenous (/sup 14/C)arachidonic acid in these cells. Microsomes metabolized (/sup 14/C)arachidonic acid to the same (/sup 14/C)PGs and (/sup 14/C)HETEs as intact cells. Pretreatment of microsomes with indomethacin completely inhibited formation of these products. These data indicate that UA ECs and UV ECs metabolize endogenous and exogenous arachidonic acid to both PGs and HETEs. Also 15-HETE and 11-HETE appear to be synthesized by a microsomal enzyme with the properties of cyclooxygenase.

  9. Prostaglandins, endotoxin and lipid A on body temperature in rats.

    PubMed Central

    Feldberg, W; Saxena, P N

    1975-01-01

    1. In unanaesthetized restrained rats kept at an ambient temperature of 21-23degrees C, rectal temperature was continuously monitored and the temperature effects of injections of prostaglandins, endotoxin from Salmonella abortus equi, lipid A, and antipyretics were examined. 2. Fever occurred when prostaglandin E1, E2, F1alpha or F2alpha (PGE1, PGE2, PGF1alpha, PGF2alpha) was injected into the cerebral ventricles in doses of 200 ng and 2 mug. PGE2 was the most potent prostaglandin followed in descending order by PGE1, PGF2alpha, and PGF1alpha. The fever produced by 2 mug of PGE1 and PGE2 was short and followed by a fall in temperature to below the pre-injection level. 3. I.V. injections of endotoxin and lipid A in doses of 3 or 10 mug usually caused a long lasting fall in temperature, but when injected into the cerebral ventricles in doses of 400 ng or 1 mug, they produced long lasting fevers. 4. Injected I.V. or I.P., indomethacin and paracetamol had a hypothermic action of their own. Indomethacin was more potent than paracetamol and both were more potent than injected I.P. 5. I.V. and I.P. injections of indomethacin and paracetamol did not reverse the hypothermia in response to I.V. endotoxin or lipid A, but the fever responses to their injection into the cerebral ventricles were prevented and abolished by the antipyretics. 6. It is concluded that in rats endotoxin and lipid A, or the endogenous pyrogens produced by them, do not readily pass through the blood-brain barrier into the brain tissue. If they do reach brain tissue, as when injected into the cerebral ventricles, they stimulate synthesis and release of prostaglandin in rats as they do in other species, and thereby produce fever. The hypothermia in response to I.V. endotoxin or lipid A, on the other hand, is thought to be independent of prostaglandin synthesis and to result from a direct toxic action on the skin vessels. PMID:1177107

  10. The ternary complex factor Net/Elk-3 participates in the transcriptional response to hypoxia and regulates HIF-1 alpha.

    PubMed

    Gross, C; Dubois-Pot, H; Wasylyk, B

    2008-02-21

    The ternary complex factor Net/Elk3 is downregulated in hypoxia and participates in the induction by hypoxia of several genes, including c-fos, vascular endothelial growth factor and egr-1. However, the global role of Net in hypoxia remains to be elucidated. We have identified, in a large-scale analysis of RNA expression using microarrays, more than 370 genes that are regulated by Net in hypoxia. In order to gain insights into the role of Net in hypoxia, we have analysed in parallel the genes regulated by HIF-1alpha, the classical factor involved in the response to hypoxia. We identified about 190 genes that are regulated by HIF-1alpha in hypoxia. Surprisingly, when we compare the genes induced by hypoxia that require either Net or HIF-1alpha, the majority are the same (75%), suggesting that the functions of both factors are closely linked. Interestingly, in hypoxia, Net regulates the expression of several genes known to control HIF-1alpha stability, including PHD2, PHD3 and Siah2, suggesting that Net regulates the stability of HIF-1alpha. We found that inhibition of Net by RNAi leads to decreased HIF-1alpha expression at the protein level in hypoxia. These results indicate that Net participates in the transcriptional response to hypoxia by regulation of HIF-1alpha protein stability. PMID:17704799

  11. Human eosinophils can express the cytokines tumor necrosis factor-alpha and macrophage inflammatory protein-1 alpha.

    PubMed Central

    Costa, J J; Matossian, K; Resnick, M B; Beil, W J; Wong, D T; Gordon, J R; Dvorak, A M; Weller, P F; Galli, S J

    1993-01-01

    By in situ hybridization, 44-100% of the blood eosinophils from five patients with hypereosinophilia and four normal subjects exhibited intense hybridization signals for TNF-alpha mRNA. TNF-alpha protein was detectable by immunohistochemistry in blood eosinophils of hypereosinophilic subjects, and purified blood eosinophils from three atopic donors exhibited cycloheximide-inhibitable spontaneous release of TNF-alpha in vitro. Many blood eosinophils (39-91%) from hypereosinophilic donors exhibited intense labeling for macrophage inflammatory protein-1 alpha (MIP-1 alpha) mRNA, whereas eosinophils of normal donors demonstrated only weak or undetectable hybridization signals for MIP-1 alpha mRNA. Most tissue eosinophils infiltrating nasal polyps were strongly positive for both TNF-alpha and MIP-1 alpha mRNA. By Northern blot analysis, highly enriched blood eosinophils from a patient with the idiopathic hypereosinophilic syndrome exhibited differential expression of TNF-alpha and MIP-1 alpha mRNA. These findings indicate that human eosinophils represent a potential source of TNF-alpha and MIP-1 alpha, that levels of expression of mRNA for both cytokines are high in the blood eosinophils of hypereosinophilic donors and in eosinophils infiltrating nasal polyps, that the eosinophils of normal subjects express higher levels of TNF-alpha than MIP-1 alpha mRNA, and that eosinophils purified from the blood of atopic donors can release TNF-alpha in vitro. Images PMID:8514874

  12. UVB light upregulates prostaglandin synthases and prostaglandin receptors in mouse keratinocytes

    SciTech Connect

    Black, Adrienne T.; Gray, Joshua P.; Shakarjian, Michael P.; Mishin, Vladimir; Laskin, Debra L.; Heck, Diane E.; Laskin, Jeffrey D.

    2008-10-01

    Prostaglandins belong to a class of cyclic lipid-derived mediators synthesized from arachidonic acid via COX-1, COX-2 and various prostaglandin synthases. Members of this family include prostaglandins such as PGE{sub 2}, PGF{sub 2{alpha}}, PGD{sub 2} and PGI{sub 2} (prostacyclin) as well as thromboxane. In the present studies we analyzed the effects of UVB on prostaglandin production and prostaglandin synthase expression in primary cultures of undifferentiated and calcium-differentiated mouse keratinocytes. Both cell types were found to constitutively synthesize PGE{sub 2}, PGD{sub 2} and the PGD{sub 2} metabolite PGJ{sub 2}. Twenty-four hours after treatment with UVB (25 mJ/cm{sup 2}), production of PGE{sub 2} and PGJ{sub 2} increased, while PGD{sub 2} production decreased. This was associated with increased expression of COX-2 mRNA and protein. UVB (2.5-25 mJ/cm{sup 2}) also caused marked increases in mRNA expression for the prostanoid synthases PGDS, mPGES-1, mPGES-2, PGFS and PGIS, as well as expression of receptors for PGE{sub 2} (EP1 and EP2), PGD{sub 2} (DP and CRTH2) and prostacyclin (IP). UVB was more effective in inducing COX-2 and DP in differentiated cells and EP1 and IP in undifferentiated cells. UVB readily activated keratinocyte PI-3-kinase (PI3K)/Akt, JNK and p38 MAP signaling pathways which are known to regulate COX-2 expression. While inhibition of PI3K suppressed UVB-induced mPGES-1 and CRTH2 expression, JNK inhibition suppressed mPGES-1, PGIS, EP2 and CRTH2, and p38 kinase inhibition only suppressed EP1 and EP2. These data indicate that UVB modulates expression of prostaglandin synthases and receptors by distinct mechanisms. Moreover, both the capacity of keratinocytes to generate prostaglandins and their ability to respond to these lipid mediators are stimulated by exposure to UVB.

  13. Acetaminophen hepatotoxicity and HIF-1{alpha} induction in acetaminophen toxicity in mice occurs without hypoxia

    SciTech Connect

    Chaudhuri, Shubhra; McCullough, Sandra S.; Hennings, Leah; Letzig, Lynda; Simpson, Pippa M.; Hinson, Jack A.; James, Laura P.

    2011-05-01

    HIF-1{alpha} is a nuclear factor important in the transcription of genes controlling angiogenesis including vascular endothelial growth factor (VEGF). Both hypoxia and oxidative stress are known mechanisms for the induction of HIF-1{alpha}. Oxidative stress and mitochondrial permeability transition (MPT) are mechanistically important in acetaminophen (APAP) toxicity in the mouse. MPT may occur as a result of oxidative stress and leads to a large increase in oxidative stress. We previously reported the induction of HIF-1{alpha} in mice with APAP toxicity and have shown that VEGF is important in hepatocyte regeneration following APAP toxicity. The following study was performed to examine the relative contribution of hypoxia versus oxidative stress to the induction of HIF-1{alpha} in APAP toxicity in the mouse. Time course studies using the hypoxia marker pimonidazole showed no staining for pimonidazole at 1 or 2 h in B6C3F1 mice treated with APAP. Staining for pimonidazole was present in the midzonal to periportal regions at 4, 8, 24 and 48 h and no staining was observed in centrilobular hepatocytes, the sites of the toxicity. Subsequent studies with the MPT inhibitor cyclosporine A showed that cyclosporine A (CYC; 10 mg/kg) reduced HIF-1{alpha} induction in APAP treated mice at 1 and 4 h and did not inhibit the metabolism of APAP (depletion of hepatic non-protein sulfhydryls and hepatic protein adduct levels). The data suggest that HIF-1{alpha} induction in the early stages of APAP toxicity is secondary to oxidative stress via a mechanism involving MPT. In addition, APAP toxicity is not mediated by a hypoxia mechanism.

  14. Leishmania donovani amastigotes impair gamma interferon-induced STAT1alpha nuclear translocation by blocking the interaction between STAT1alpha and importin-alpha5.

    PubMed

    Matte, Christine; Descoteaux, Albert

    2010-09-01

    The protozoan parasite Leishmania donovani, the etiological agent of visceral leishmaniasis, is renowned for its capacity to sabotage macrophage functions and signaling pathways stimulated by activators such as gamma interferon (IFN-gamma). Our knowledge of the strategies utilized by L. donovani to impair macrophage responsiveness to IFN-gamma remains fragmentary. In the present study, we investigated the impact of an infection by the amastigote stage of L. donovani on IFN-gamma responses and signaling via the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in mouse bone marrow-derived macrophages. The levels of IFN-gamma-induced expression of major histocompatibility complex class II and inducible nitric oxide synthase (iNOS) were strongly reduced in L. donovani amastigote-infected macrophages. As the expression of those genes is mediated by the transcription factors STAT1alpha and IFN regulatory factor 1 (IRF-1), we investigated their activation in amastigote-infected macrophages treated with IFN-gamma. We found that whereas STAT1alpha protein levels and the levels of phosphorylation on Tyr701 and Ser727 were normal, IRF-1 expression was inhibited in infected macrophages. This inhibition of IRF-1 expression correlated with a defective nuclear translocation of STAT1alpha, and further analyses revealed that the IFN-gamma-induced STAT1alpha association with the nuclear transport adaptor importin-alpha5 was compromised in L. donovani amastigote-infected macrophages. Taken together, our results provide evidence for a novel mechanism used by L. donovani amastigotes to interfere with IFN-gamma-activated macrophage functions and provide a better understanding of the strategies deployed by this parasite to ensure its intracellular survival. PMID:20566692

  15. The Bitter Barricading of Prostaglandin Biosynthesis Pathway: Understanding the Molecular Mechanism of Selective Cyclooxygenase-2 Inhibition by Amarogentin, a Secoiridoid Glycoside from Swertia chirayita

    PubMed Central

    Sundar, Durai; Thorat, Sunil S.

    2014-01-01

    Swertia chirayita, a medicinal herb inhabiting the challenging terrains and high altitudes of the Himalayas, is a rich source of essential phytochemical isolates. Amarogentin, a bitter secoiridoid glycoside from S. chirayita, shows varied activity in several patho-physiological conditions, predominantly in leishmaniasis and carcinogenesis. Experimental analysis has revealed that amarogentin downregulates the cyclooxygenase-2 (COX-2) activity and helps to curtail skin carcinogenesis in mouse models; however, there exists no account on selective inhibition of the inducible cyclooxygenase (COX) isoform by amarogentin. Hence the computer-aided drug discovery methods were used to unravel the COX-2 inhibitory mechanism of amarogentin and to check its selectivity for the inducible isoform over the constitutive one. The generated theoretical models of both isoforms were subjected to molecular docking analysis with amarogentin and twenty-one other Food and Drug Authority (FDA) approved lead molecules. The post-docking binding energy profile of amarogentin was comparable to the binding energy profiles of the FDA approved selective COX-2 inhibitors. Subsequent molecular dynamics simulation analysis delineated the difference in the stability of both complexes, with amarogentin-COX-2 complex being more stable after 40ns simulation. The total binding free energy calculated by MMGBSA for the amarogentin-COX-2 complex was −52.35 KCal/mol against a binding free energy of −8.57 KCal/mol for amarogentin-COX-1 complex, suggesting a possible selective inhibition of the COX-2 protein by the natural inhibitor. Amarogentin achieves this potential selectivity by small, yet significant, structural differences inherent to the binding cavities of the two isoforms. Hypothetically, it might block the entry of the natural substrates in the hydrophobic binding channel of the COX-2, inhibiting the cyclooxygenation step. To sum up briefly, this work highlights the mechanism of the possible

  16. Inhibition of the prostaglandin EP2 receptor is neuroprotective and accelerates functional recovery in a rat model of organophosphorus induced status epilepticus.

    PubMed

    Rojas, Asheebo; Ganesh, Thota; Lelutiu, Nadia; Gueorguieva, Paoula; Dingledine, Raymond

    2015-06-01

    Exposure to high levels of organophosphorus compounds (OP) can induce status epilepticus (SE) in humans and rodents via acute cholinergic toxicity, leading to neurodegeneration and brain inflammation. Currently there is no treatment to combat the neuropathologies associated with OP exposure. We recently demonstrated that inhibition of the EP2 receptor for PGE2 reduces neuronal injury in mice following pilocarpine-induced SE. Here, we investigated the therapeutic effects of an EP2 inhibitor (TG6-10-1) in a rat model of SE using diisopropyl fluorophosphate (DFP). We tested the hypothesis that EP2 receptor inhibition initiated well after the onset of DFP-induced SE reduces the associated neuropathologies. Adult male Sprague-Dawley rats were injected with pyridostigmine bromide (0.1 mg/kg, sc) and atropine methylbromide (20 mg/kg, sc) followed by DFP (9.5 mg/kg, ip) to induce SE. DFP administration resulted in prolonged upregulation of COX-2. The rats were administered TG6-10-1 or vehicle (ip) at various time points relative to DFP exposure. Treatment with TG6-10-1 or vehicle did not alter the observed behavioral seizures, however six doses of TG6-10-1 starting 80-150 min after the onset of DFP-induced SE significantly reduced neurodegeneration in the hippocampus, blunted the inflammatory cytokine burst, reduced microglial activation and decreased weight loss in the days after status epilepticus. By contrast, astrogliosis was unaffected by EP2 inhibition 4 d after DFP. Transient treatments with the EP2 antagonist 1 h before DFP, or beginning 4 h after DFP, were ineffective. Delayed mortality, which was low (10%) after DFP, was unaffected by TG6-10-1. Thus, selective inhibition of the EP2 receptor within a time window that coincides with the induction of cyclooxygenase-2 by DFP is neuroprotective and accelerates functional recovery of rats. PMID:25656476

  17. Inhibition of the prostaglandin EP2 receptor is neuroprotective and accelerates functional recovery in a rat model of organophosphorus induced status epilepticus

    PubMed Central

    Rojas, Asheebo; Ganesh, Thota; Lelutiu, Nadia; Gueorguieva, Paoula; Dingledine, Raymond

    2015-01-01

    Exposure to high levels of organophosphorus compounds (OP) can induce status epilepticus (SE) in humans and rodents via acute cholinergic toxicity, leading to neurodegeneration and brain inflammation. Currently there is no treatment to combat the neuropathologies associated with OP exposure. We recently demonstrated that inhibition of the EP2 receptor for PGE2 reduces neuronal injury in mice following pilocarpine-induced SE. Here, we investigated the therapeutic effects of an EP2 inhibitor (TG6-10-1) in a rat model of SE using diisopropyl fluorophosphate (DFP). We tested the hypothesis that EP2 receptor inhibition initiated well after the onset of DFP-induced SE reduces the associated neuropathologies. Adult male Sprague-Dawley rats were injected with pyridostigmine bromide (0.1 mg/kg, sc) and atropine methylbromide (20 mg/kg, sc) followed by DFP (9.5 mg/kg, ip) to induce SE. DFP administration resulted in prolonged upregulation of COX-2. The rats were administered TG6-10-1 or vehicle (ip) at various time points relative to DFP exposure. Treatment with TG6-10-1 or vehicle did not alter the observed behavioral seizures, however six doses of TG6-10-1 starting 80-150 min after the onset of DFP-induced SE significantly reduced neurodegeneration in the hippocampus, blunted the inflammatory cytokine burst, reduced microglial activation and decreased weight loss in the days after status epilepticus. By contrast, astrogliosis was unaffected by EP2 inhibition 4 d after DFP. Transient treatments with the EP2 antagonist 1 h before DFP, or beginning 4 h after DFP, were ineffective. Delayed mortality, which was low (10%) after DFP, was unaffected by TG6-10-1. Thus, selective inhibition of the EP2 receptor within a time window that coincides with the induction of cyclooxygenase-2 by DFP is neuroprotective and accelerates functional recovery of rats. PMID:25656476

  18. Isoflurane attenuates LPS-induced acute lung injury by targeting miR-155-HIF1-alpha.

    PubMed

    Hu, Rong; Zhang, Ying; Yang, Xiaohua; Yan, Jia; Sun, Yu; Chen, Zhifeng; Jiang, Hong

    2015-01-01

    Isoflurane alleviates the inflammatory response in endotoxin-induced acute lung injury (ALI). In this study, we investigated the protective mechanism of isoflurane postconditioning in lipopolysaccharide (LPS)induced ALI. Exposure to isoflurane decreased miR-155 and upregulated HIF-1 alpha and HO-1 mRNA and protein. The effects of isoflurane on HIF-1 alpha mRNA and protein could be inhibited by overexpression of miR-155. Furthermore, mice overexpressing miR-155 had higher levels of TNF-alpha and IL-1 beta in BALF when exposed to isoflurane after LPS challenge.Conversely, downregulation of miR-155 promoted isoflurane effects on HIF-1 alpha expression. These results suggest that isoflurane posttreatment hr alleviates LPS-induced ALI and cell injury by triggering miR-155-HIF-1 alpha pathway, leading to upregulation of HO-1. PMID:25553444

  19. Endogenous prostaglandin in guinea pig taenia coli.

    PubMed

    Yamaguchi, T; Hitzig, B; Coburn, R F

    1976-01-01

    Prostaglandin (PGE) is synthesized in the guinea pig taenia coli. A low threshold concentration for an effect of exogenous PGE1 or PGE2 on spontaneous mechanical activity was demonstrated. The PG synthetase inhibitors aspirin, indomethacin, and 5,8,11,14-eicosatetraynoic acid, at concentrations that inhibited PGE efflux, had effects on spontaneous mechanical activity, membrane potential, membrane resistance, and evoked and spontaneous action potentials (single and double sucrose-gap methods) that were consistent with an action due to inhibition of membrane PGE concentration. The threshold concentration of indomethacin, which inhibited PGE efflux, was the same as the concentration that inhibited spontaneous mechanical activity. Pretreatment with ouabain (10(-6)-10(-5) g/ml) or elevated extracellular K+ (29 and 126 mM) made the guinea pig taenia coli entirely refractory to exogenous PGE1 or PGE2; the mechanical effects of the three prostaglandin synthetase inhibitors also were absent in the presence of elevated K+ or ouabain. The data are consistent with a hypothesis that, under conditions of our experiments, endogenous PGE has an effect on resting tension and spontaneous mechanical activity and on properties of the surface membrane of the guinea pig taenia coli. PMID:1251900

  20. Prostaglandin E2 inhibits vasotocin-induced osmotic water permeability in the frog urinary bladder by EP1-receptor-mediated activation of NO/cGMP pathway.

    PubMed

    Bachteeva, Vera; Fock, Ekaterina; Lavrova, Elena; Nikolaeva, Svetlana; Gambaryan, Stepan; Parnova, Rimma

    2007-07-01

    PGE(2) is a well-known inhibitor of the antidiuretic hormone-induced increase of osmotic water permeability (OWP) in different osmoregulatory epithelia; however, the mechanisms underlying this effect of PGE(2) are not completely understood. Here, we report that, in the frog Rana temporaria urinary bladder, EP(1)-receptor-mediated inhibition of arginine-vasotocin (AVT)-induced OWP by PGE(2) is attributed to increased generation of nitric oxide (NO) in epithelial cells. It was shown that the inhibitory effect of 17-phenyl-trinor-PGE(2) (17-ph-PGE(2)), an EP(1) agonist, on AVT-induced OWP was significantly reduced in the presence of 7-nitroindazole (7-NI), a neuronal NO synthase (nNOS) inhibitor. NO synthase (NOS) activity in both lysed and intact epithelial cells measured as a rate of conversion of l-[(3)H]arginine to l-[(3)H]citrulline was Ca(2+) dependent and inhibited by 7-NI. PGE(2) and 17-ph-PGE(2), but not M&B-28767 (EP(3) agonist) or butaprost (EP(2) agonist), stimulated NOS activity in epithelial cells. The above effect of PGE(2) was abolished in the presence of SC-19220, an EP(1) antagonist. 7-NI reduced the stimulatory effect of 17-ph-PGE(2) on NOS activity. 17-ph-PGE(2) increased intracellular Ca(2+) concentration and cGMP in epithelial cells. Western blot analysis revealed an nNOS expression in epithelial cells. These results show that the inhibitory effect of PGE(2) on AVT-induced OWP in the frog urinary bladder is based at least partly on EP(1)-receptor-mediated activation of the NO/cGMP pathway, suggesting a novel cross talk between AVT, PGE(2), and nNOS that may be important in the regulation of water transport. PMID:17363677

  1. Prostaglandins: pharmacology and clinical application.

    PubMed

    Karim, S M; Hillier, K

    1974-01-01

    Prostaglandin research has been 1 of the most stimulating features of biomedical investigation in the past decade. Interest developed at a time of expanding knowledge of hormonal and neurohormonal behavior and research work received a tremendous impetus in the early 1960s with the elucidation in Sweden of the chemical structures of prostaglandins, followed by the discovery of their biosynthetic pathways. The original findings of large amounts of prostaglandin in the male accessory genital glands and their secretions, and subsequent discovery in the menstrual and amniotic fluids linked these substances with human production. As a result of further investigation, clinical applications of prostaglandins for the induction of labor and termination of early unwanted pregnancies have been developed. Apart from the functions of the prostaglandins in the reproductive area, they have been shown to have a widespread distribution in the body and produce many different pharmacological effects. Prostaglandins are thought to be involved in the regulation of blood pressure and through their vascular effects have therapeutic potential in the treatment of hypertension and peripheral vascular disease. Through their bronchodilator effect, some prostaglandins may become useful in the treatment of asthma. PMID:4611742

  2. Misidentification of prostamides as prostaglandins.

    PubMed

    Glass, Michelle; Hong, Jiwon; Sato, Timothy A; Mitchell, Murray D

    2005-07-01

    Prostaglandins and endogenous cannabinoid metabolites share the same lipid backbone with differing polar head groups at exactly the position through which a large molecule is attached to provide antigenicity and thus raise antisera. Hence, we hypothesized that antisera raised against prostaglandins linked to a large molecule such as BSA at the carboxyl functional group would also recognize endogenous cannabinoid metabolites and lead to highly misleading interpretations of data. We found major cross-reactivity of commercial antisera raised to prostaglandins with endocannabinoid metabolites. Furthermore, in a well-characterized cell line (WISH) or primary amnion tissue explants, endocannabinoid treatment led to increased production of endocannabinoid metabolites as opposed to primary prostaglandins. This was apparent only after separation of products by thin-layer chromatography, because they measured as prostaglandins by radioimmunoassay. These findings have major implications for our interpretation of data in situations in which these prostaglandin-like molecules are formed, and they stress the need for chromatographic or spectrometric confirmation of prostaglandin production detected by antibody-based methods. PMID:15863842

  3. Stretch-induced prostaglandins and protein turnover in cultured skeletal muscle

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.; Hatfaludy, Sophia; Sohar, Istvan; Shansky, Janet

    1990-01-01

    The purpose of the study is to determine whether mechanical stimulation of cultured muscle cells influences prostaglandin efflux rates and whether they are related to stretch-induced alterations in protein turnover rates. The materials and methods of the experiment, including cell cultures, mechanical stimulation, protein synthesis, and degradation assays are outlined, and emphasis is placed on the effect of short-term mechanical stimulation in basal medium prostaglandin efflux from cultured skeletal muscle and stretch-induced alterations in prostaglandins efflux in complete medium. The major finding of the study is that mechanical stimulation of tissue-cultured skeletal-muscle cells under conditions inducing skeletal-muscle hypertropy increases the efflux of PGE(2) and PGE(2-alpha) but not 6-keto-PGF(1-alpha), the prostacyclin product.

  4. [Prostaglandins in gynecology and obstetrics].

    PubMed

    Klausch, B; Kyank, H

    1972-06-01

    A review of early research (up through 1970) on prostaglandins (PGs) is presented. Their chemical structure and classification based on their ring-structure is detailed as well as various analytic methods of mammalian tissues and body fluids. For clinical use PGE1 and 2, PGF2alpha and PGA1 are the most significant ones because of their properties. PGs have many physiological activities encompassing many organ systems. Their pharmacological actions include: 1) stimulation of nonvascular smooth muscle; 2) peripheral vasodilation (excluding PGFs which cause vasoconstriction); 3) inhibition of lipolysis; 4) inhibition of platelet aggregation; 5) inhibition of gastric peristalsis and gastric juice secretion; 6) bronchodilation; and 7) inhibition of spontaneous CNS activity. The level of PGEs in semen is closely related to the degree of fertility; normally fertile men have 55 mcg PGE/ml and never less than 11 mcg/ml. Current studies are under way on the effect of PGE in artificial insemination of sperm of subfertile men. PGF2alpha and PGE2 stimulate menstruation and uterine contraction; other PGs inhibit uterine contraction. PGs from semen have a role in sperm transport and possibly act on fallopian tube motility aiding sperm capacitation, and ovum retention and transport. Early trials with PGs point to a possible action as an abortifacient, as a once-a-month contraceptive, or a postconception contraceptive agent. PGF2alpha is found in variable concentrations in maternal blood during contraction of the pregnant uterus; levels increase as labor progresses. PGs have been used for labor induction, for induction of abortion and in mole pregnancy. Given as a constant intravenous infusion they produce regular contractions leading to natural expulsion of the fetus and causing very few side effects in the woman with no adverse effects on the fetus. PGs' action compares favorably with that of oxytocin and is preferable for labor induction in certain pregnancy complications. PGE1

  5. Is brain prostaglandin synthesis involved in responses to cold?

    PubMed Central

    Cranston, W I; Hellon, R F; Mitchell, D

    1975-01-01

    1. Experiments with rats have suggested that prostaglandin synthesis in the C.N.S. may mediate thermoregulatory reactions to cold. This possibility was investigated in cats using two types of experiment. 2. In one series of experiments, c.s.f. collected from the cisterna magna of conscious cats exposed to a cold and a hot environment was assayed for prostaglandin-like activity. During cold exposure there was a slight increase in activity which persisted after return to neutral ambient temperature. There was no correlation between prostaglandin-like activity and rectal temperature. During the heat exposure there was no demonstrable change in activity. 3. In the second series, conscious cats were exposed to cold conditions and given intravenous injections of salicylate, paracetamol, or indomethacin, all of which inhibit prostaglandin synthesis. Indomethacin salicylate nor paracetamol caused any significant change in rectal temperature. 4. The results do not support a role for C.N.S. prostaglandin synthesis in thermoregulatory reactions to cold in cats. PMID:1177099

  6. Prostaglandins are not involved in the differentiation or growth of cultured small intestinal cells.

    PubMed

    Stange, E F; Schneider, A; Preclik, G; Ditschuneit, H

    1986-01-01

    Prostaglandins have been reported to exert trophic effects on gastrointestinal tissues. To determine whether there is a direct interaction with enterocytes, prostaglandins PGE2, PGF2 alpha, PGA2, PGB2 and the stable PGE2 derivative suleprost as well as the prostacyclin derivative nileprost were tested in rabbit ileal mucosa under organ culture conditions. At concentrations between 10(-9) and 10(-5) M, none of the prostaglandins significantly affected biopsy DNA or protein content, or the activity of the brush border enzymes alkaline phosphatase, lactase, sucrase or maltase. The inhibition of endogenous prostaglandin synthesis with indomethacin also failed to alter these parameters. Moreover, the growth rate of a rat duodenal crypt cell line was unaffected when cultured in the presence of PGE2, PGF2 alpha or indomethacin. Thus, there was no evidence for a direct effect of exogenous or endogenous prostaglandins or their deficiency on the differentiation or growth in cultured small intestinal cells. PMID:3817331

  7. Andrographolide down-regulates hypoxia-inducible factor-1{alpha} in human non-small cell lung cancer A549 cells

    SciTech Connect

    Lin, Hui-Hsuan; Tsai, Chia-Wen; Chou, Fen-Pi; Wang, Chau-Jong; Hsuan, Shu-Wen; Wang, Cheng-Kun; Chen, Jing-Hsien

    2011-02-01

    Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to inhibit non-small cell lung cancer (NSCLC) A549 cell migration and invasion via down-regulation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Here we demonstrated that Andro inhibited the expression of hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) in A549 cells. HIF-1{alpha} plays an important role in tumor growth, angiogenesis and lymph node metastasis of NSCLC. The Andro-induced decrease of cellular protein level of HIF-1{alpha} was correlated with a rapid ubiquitin-dependent degradation of HIF-1{alpha}, and was accompanied by increased expressions of hydroxyl-HIF-1{alpha} and prolyl hydroxylase (PHD2), and a later decrease of vascular endothelial growth factor (VEGF) upon the treatment of Andro. The Andro-inhibited VEGF expression appeared to be a consequence of HIF-1{alpha} inactivation, because its DNA binding activity was suppressed by Andro. Molecular data showed that all these effects of Andro might be mediated via TGF{beta}1/PHD2/HIF-1{alpha} pathway, as demonstrated by the transfection of TGF{beta}1 overexpression vector and PHD2 siRNA, and the usage of a pharmacological MG132 inhibitor. Furthermore, we elucidated the involvement of Andro in HIF-1{alpha} transduced VEGF expression in A549 cells and other NSCLC cell lines. In conclusion, these results highlighted the potential effects of Andro, which may be developed as a chemotherapeutic or an anti-angiogenesis agent for NSCLC in the future.

  8. Prostaglandins, bioassay and inflammation

    PubMed Central

    Flower, R J

    2006-01-01

    The formation of the British Pharmacological Society coincided almost exactly with a series of ground-breaking studies that ushered in an entirely new field of research – that of lipid mediator pharmacology. For many years following their chemical characterisation, lipids were considered only to be of dietary or structural importance. From the 1930s, all this changed – slowly at first and then more dramatically in the 1970s and 1980s with the emergence of the prostaglandins (PGs), the first intercellular mediators to be clearly derived from lipids, in a dynamic on-demand system. The PGs exhibit a wide range of biological activities that are still being evaluated and their properties underlie the action of one of the world's all-time favourite medicines, aspirin, as well as its more modern congeners. This paper traces the development of the PG field, with particular emphasis on the skilful utilisation of the twin techniques of bioassay and analytical chemistry by U.K. and Swedish scientists, and the intellectual interplay between them that led to the award of a joint Nobel Prize to the principal researchers in the PG field, half a century after the first discovery of these astonishingly versatile mediators. PMID:16402103

  9. Endothelial monocyte activating polypeptide-II modulates endothelial cell responses by degrading hypoxia-inducible factor-1alpha through interaction with PSMA7, a component of the proteasome

    SciTech Connect

    Tandle, Anita T.; Calvani, Maura; Uranchimeg, Badarch; Zahavi, David; Melillo, Giovanni; Libutti, Steven K.

    2009-07-01

    The majority of human tumors are angiogenesis dependent. Understanding the specific mechanisms that contribute to angiogenesis may offer the best approach to develop therapies to inhibit angiogenesis in cancer. Endothelial monocyte activating polypeptide-II (EMAP-II) is an anti-angiogenic cytokine with potent effects on endothelial cells (ECs). It inhibits EC proliferation and cord formation, and it suppresses primary and metastatic tumor growth in-vivo. However, very little is known about the molecular mechanisms behind the anti-angiogenic activity of EMAP-II. In the present study, we explored the molecular mechanism behind the anti-angiogenic activity exerted by this protein on ECs. Our results demonstrate that EMAP-II binds to the cell surface {alpha}5{beta}1 integrin receptor. The cell surface binding of EMAP-II results in its internalization into the cytoplasmic compartment where it interacts with its cytoplasmic partner PSMA7, a component of the proteasome degradation pathway. This interaction increases hypoxia-inducible factor 1-alpha (HIF-1{alpha}) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1{alpha} mediated transcriptional activity as well as HIF-1{alpha} mediated angiogenic sprouting of ECs. HIF-1{alpha} plays a critical role in angiogenesis by activating a variety of angiogenic growth factors. Our results suggest that one of the major anti-angiogenic functions of EMAP-II is exerted through its inhibition of the HIF-1{alpha} activities.

  10. Contractile and relaxant actions of prostaglandins on guinea-pig isolated trachea.

    PubMed Central

    Coleman, R. A.; Kennedy, I.

    1980-01-01

    1 The effects of 12 prostaglandins on guinea-pig isolated trachea have been examined in the presence of indomethacin. Two series of experiments were carried out, the first on preparations without tone ('zero tone'), and the second on preparations with tone induced with acetylcholine ('high tone'). 2 The compounds tested fell into two groups. The first, comprising prostaglandins F1 alpha, F2 alpha, F2 alpha acetal, I2 and Wy 17186, contracted both zero and high tone preparations. The second, comprising prostaglandins A1, A2, B1, B2, E1, E2 and F2 beta, contracted zero, but relaxed high tone preparations. Responses to the second group of compounds are probably the resultant of their contractile and relaxant actions. 3 The order of potency for contracting zero tone preparations was prostaglandin E (PGE) greater than F = 1 = Wy 17186 greater than B greater than A, 2-series compounds being 5 to 18 times more potent than 1-series compounds. 4 The order of potency for relaxing high tone preparations was PGE greater than F beta greater than B greater than A greater than Wy 17186 greater than F alpha = I = 0. There was little difference between the potency of 1- and 2-series compounds. 5 The possible relevance of these results to the interpretation of the effects of prostaglandins on human airways is discussed. PMID:7052343

  11. Effect of radiation on prostaglandin production by human bowel in vitro

    SciTech Connect

    Gal, D.; Strickland, D.M.; Lifshitz, S.; Buchsbaum, H.J.; Mitchell, M.D.

    1984-05-01

    The effect of gamma irradiation on the production of prostaglandins by human colon was investigated. Squares of tissue in organ culture dishes were irradiated with 500, 1000, or 2500 rad in single applications. Tissues that were not irradiated served as controls. After treatment the tissues were superfused and prostaglandin concentrations in the effluent fluid were determined. The rates of production of prostaglandins E/sub 2/ and F/sub 2..cap alpha../ by irradiated tissues were significantly lower than those of nonirradiated tissues. Neither the release of lactate dehydrogenase nor the rate of production of 13,14-dihydro-15-keto-prostaglandin F/sub 2..cap alpha../ were increased in the irradiated samples, suggesting that neither decreased cell viability nor increased prostaglandin metabolism accounted for the decreased prostaglandin production rates. The authors conclude that irradiation of the human colon in vitro results in an acute inhibition of prostaglandin synthesis. The cytoprotective nature of prostaglandins is discussed with regard to the possible pathophysiological significance of these findings.

  12. Dioscorea japonica extract down-regulates prostaglandin E2 synthetic pathway and induces apoptosis in lung cancer cells

    PubMed Central

    Suzuki-Yamamoto, Toshiko; Tanaka, Sayuri; Tsukayama, Izumi; Takafuji, Miki; Hanada, Takae; Arakawa, Toshiya; Kawakami, Yuki; Kimoto, Masumi; Takahashi, Yoshitaka

    2014-01-01

    Prostaglandin E2 plays a role in an array of pathophysiological responses, including inflammation, carcinogenesis and so on. Prostaglandin E2 is synthesized from arachidonic acid by the enzymes cyclooxygenase and prostaglandin E synthase. In some pathological conditions, the isozymes cyclooxygenase-2 and microsomal prostaglandin E synthase-1 are transiently induced, leading to prostaglandin E2 overproduction. The present study showed that Dioscorea japonica extract suppresses mRNA expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in human non-small-cell lung carcinoma A549 cells in a dose-dependent manner. The suppressive effects of Dioscorea japonica extract on the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 were confirmed by Western blotting, cyclooxygenase activity and prostaglandin E2 production. Dioscorea japonica extract induced the translocation of nuclear factor-κB from the nucleus to the cytosol and inhibited the activity of the cyclooxygenase-2 promoter. Furthermore Dioscorea japonica extract suppressed the expression of the anti-apoptotic factor B-cell chronic lymphocytic leukemia/lymphoma 2 and enhanced apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive intensity in A549 cells. These results suggest that Dioscorea japonica extract suppresses the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1, with the regulation of the transcriptional activity of cyclooxygenase-2, and induces apoptosis in cancer cells. Thus, Dioscorea japonica may contribute to the prevention of prostaglandin E2-mediated pathophysiological responses such as carcinogenesis and inflammation. PMID:25411520

  13. Effects of prostaglandin E2 and vascular endothelial growth factor on sperm might lead to endometriosis-associated infertility.

    PubMed

    Lee, Te-Ching; Ho, Han-Chen

    2011-01-01

    Significantly higher levels of prostaglandin E2 and vascular endothelial growth factor were associated with the severity of endometriosis. In this study, pathologic concentrations of prostaglandin E2 and vascular endothelial growth factor found in endometriotic women significantly inhibited sperm motility, acrosome reaction, and sperm-oocyte interaction, which might result in endometriosis-associated subfertility/infertility. PMID:20864099

  14. Lipopolysaccharide induces macrophage migration via prostaglandin D(2) and prostaglandin E(2).

    PubMed

    Tajima, Tsuyoshi; Murata, Takahisa; Aritake, Kosuke; Urade, Yoshihiro; Hirai, Hiroyuki; Nakamura, Masataka; Ozaki, Hiroshi; Hori, Masatoshi

    2008-08-01

    Lipopolysaccharide (LPS) produces prostaglandins (PGs) concomitant to eliciting macrophage migration. We evaluated the role of PGs in initiating the migration of macrophages, especially focusing on PGD(2) and PGE(2). In RAW264.7 macrophages, cyclooxygenase (COX)-2 inhibitor, CAY10404 [3-(4-methylsulphonylphenyl)-4-phenyl-5-trifluoromethylisoxazole], completely inhibited LPS-mediated migration at 4 h (early phase) but only partially inhibited the migration at 8 h (late phase), suggesting the presence of PG-dependent and -independent pathways. In the early phase, LPS up-regulated mRNA expressions of COX-2, hematopoietic PGD synthase (H-PGDS), and microsomal-PGE synthase 1, increasing PGD(2) and PGE(2) substantially. The chemoattractant receptor-homologous molecule expressed on Th2 lymphocytes (CRTH2) agonist, DK-PGD(2) (13-14-dihydro-15-keto-PGD(2)), and the EP4 agonist, ONO-AE1-329 (16-{3-methoxymethyl}phenyl-omega-tetranor-3,7-dithia-prostaglandin E(1)), but not selective agonists of D prostanoid receptor, E prostanoid receptor (EP) 2, or EP3, stimulated random migration (chemokinesis). In peritoneal macrophages from CRTH2-deficient and H-PGDS-deficient mice, LPS-mediated migration was significantly inhibited at either early or late phases of the migration. The H-PGDS inhibitor, HQL-79 [4-(diphenylmethoxy)-1-[3-(1H-tetrazol-5-yl)propyl-piperidine

  15. Prostaglandin E3 metabolism and cancer

    PubMed Central

    Yang, Peiying; Jiang, Yan; Fischer, Susan M.

    2015-01-01

    The anticancer activity of n-3 fatty acids, especially those derived from fish, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid) (DHA), has been studied for centuries. While there is a growing body of evidence that EPA and DHA may influence cancer initiation and development through targeting multiple events of tumor development, the underlying mechanisms responsible for these activities are still not fully understood. A number of studies have suggested that the anticancer activities of EPA and DHA are associated with their effects on eicosanoid metabolism by which they inhibit prostaglandin E2 (PGE2) production. In contrast to DHA, EPA can function as a substrate for cyclooxygenases (COXs) to synthesize unique 3-series prostaglandin compounds, especially PGE3. With advance technology in mass spectrometry, there is renewed interest in studying the role of PGE3 in EPA elicited anti-proliferative activity in various cancers, with some promising results. Here, we summarize the regulation of PGE3 synthesis in cancer cells and its role in EPA elicited anticancer activity. The development of PGE3 and its metabolites as potential biomarkers for future clinical evaluation of EPA and fish oil in cancer care is discussed. PMID:24657656

  16. Expression of gastric antisecretory and prostaglandin E receptor binding activity of misoprostol by misoprostol free acid.

    PubMed

    Tsai, B S; Kessler, L K; Stolzenbach, J; Schoenhard, G; Bauer, R F

    1991-05-01

    In enriched canine parietal cell preparations, misoprostol, an analog of prostaglandin E1 methyl ester, was rapidly deesterified to misoprostol free acid. Under this circumstance, misoprostol and misoprostol free acid exhibited equal antisecretory potency against histamine-stimulated acid secretion and bound equally well to prostaglandin E receptors. When the deesterification of misoprostol was inhibited by paraoxon, an esterase inhibitor, the antisecretory and receptor binding activity of misoprostol was markedly reduced, with potency much less than misoprostol free acid. These results indicate that misoprostol free acid is the active biological form of misoprostol that binds to prostaglandin E receptors and mediates the antisecretory action of misoprostol. PMID:1850690

  17. The release of prostaglandin E2 from the skin of the plaice, Pleuronectes platessa L.

    PubMed Central

    Anderson, A. A.; Fletcher, T. C.; Smith, G. M.

    1979-01-01

    1 A fungal extract which produces a cutaneous hypersensitivity reaction in the plaice, Pleuronectes platessa L., was incubated in vitro with the skin of this teleost fish. Samples of incubation media were assayed for smooth muscle stimulating activity. 2 Prostaglandin E2 was identified by bioassay, thin-layer chromatography, ultraviolet absorption spectroscopy and gas chromatography--mass spectrometry. Release from challenged skin was maximum after 60 min incubation. 3 Analysis of the fatty acid composition of plaice skin showed that although arachidonic acid was present (3% of total fatty acids), the precursor of prostaglandin E3, eicosapentaenoic acid contributed 9% of total. 4 Indomethacin (50 mg/kg i.p) did not inhibit the erythema induced by the fungal extract, whilst a dose of 1 mg/kg maximally inhibited prostaglandin release from skin on incubation in vitro. 5 It is concluded that prostaglandins do not have an exclusive role in the mediation of the hypersensitivity reaction. PMID:465893

  18. Sphingosine kinase 1: a new modulator of hypoxia inducible factor 1alpha during hypoxia in human cancer cells.

    PubMed

    Ader, Isabelle; Brizuela, Leyre; Bouquerel, Pierre; Malavaud, Bernard; Cuvillier, Olivier

    2008-10-15

    Here, we provide the first evidence that sphingosine kinase 1 (SphK1), an oncogenic lipid kinase balancing the intracellular level of key signaling sphingolipids, modulates the transcription factor hypoxia inducible factor 1alpha (HIF-1alpha), master regulator of hypoxia. SphK1 activity is stimulated under low oxygen conditions and regulated by reactive oxygen species. The SphK1-dependent stabilization of HIF-1alpha levels is mediated by the Akt/glycogen synthase kinase-3beta signaling pathway that prevents its von Hippel-Lindau protein-mediated degradation by the proteasome. The pharmacologic and RNA silencing inhibition of SphK1 activity prevents the accumulation of HIF-1alpha and its transcriptional activity in several human cancer cell lineages (prostate, brain, breast, kidney, and lung), suggesting a canonical pathway. Therefore, we propose that SphK1 can act as a master regulator for hypoxia, giving support to its inhibition as a valid strategy to control tumor hypoxia and its molecular consequences. PMID:18922940

  19. Suppression of hypoxia-inducible factor-1alpha and its downstream genes reduces acute hyperglycemia-enhanced hemorrhagic transformation in a rat model of cerebral ischemia.

    PubMed

    Chen, Chunhua; Ostrowski, Robert P; Zhou, Changman; Tang, Jiping; Zhang, John H

    2010-07-01

    We evaluated a role of hypoxia-inducible factor-1alpha (HIF-1alpha) and its downstream genes in acute hyperglycemia-induced hemorrhagic transformation in a rat model of focal cerebral ischemia. Male Sprague-Dawley rats weighing 280-300 g (n = 105) were divided into sham, 90 min middle cerebral artery occlusion (MCAO), MCAO plus HIF-1alpha inhibitors, 2-methoxyestradiol (2ME2) or 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), groups. Rats received an injection of 50% dextrose (6 ml/kg intraperitoneally) at 15 min before MCAO. HIF-1alpha inhibitors were administered at the onset of reperfusion. The animals were examined for neurological deficits and sacrificed at 6, 12, 24, and 72 hr following MCAO. The cerebral tissues were collected for histology, zymography, and Western blot analysis. The expression of HIF-1alpha was increased in ischemic brain tissues after MCAO and reduced by HIF-1alpha inhibitors. In addition, 2ME2 reduced the expression of vascular endothelial growth factor (VEGF) and the elevation of active matrix metalloproteinase-2 and -9 (MMP-2/MMP-9) in the ipsilateral hemisphere. Both 2ME2 and YC-1 reduced infarct volume and ameliorated neurological deficits. However, only 2ME2 attenuated hemorrhagic transformation in the ischemic territory. In conclusion, the inhibition of HIF-1alpha and its downstream genes attenuates hemorrhagic conversion of cerebral infarction and ameliorates neurological deficits after focal cerebral ischemia. PMID:20155812

  20. Biological activity profiles of 1alpha,25-dihydroxyvitamin D2, D3, D4, D7, and 24-epi-1alpha,25-dihydroxyvitamin D2.

    PubMed

    Tsugawa, N; Nakagawa, K; Kawamoto, Y; Tachibana, Y; Hayashi, T; Ozono, K; Okano, T

    1999-04-01

    We have synthesized several 1alpha,25-dihydroxyvitamin D [1alpha,25(OH)2D] derivatives and evaluated their biological activity in terms of their binding affinity for the vitamin D receptor (VDR) and vitamin D-binding protein (DBP), antiproliferative or differentiation-inducing effects on human promyelocytic leukemic HL-60 cells, and transcriptional activity on a rat 25-hydroxyvitamin D3-24-hydroxylase gene promoter, including two vitamin D-responsive elements (VDREs), and human osteocalcin gene promoter, including a VDRE in transfected human osteosarcoma MG-63 cells. Furthermore, human VDR- or retinoic acid X receptor alpha (RXR alpha)-mediated luciferase activities of the derivatives were also measured by a one-hybrid system in human epitheloid carcinoma, cervix HeLa cells and African green monkey kidney CV-1 cells. Binding affinity for VDR, bone-resorbing activity, antiproliferative and cell-differentiating effects, transactivation potencies on target genes and VDR- or RXR alpha-mediated gene regulations of 1alpha,25(OH)2D2 and 1alpha,25(OH)2D4 were almost comparable to the effects of 1alpha,25(OH)2D3 while 24-epi-1alpha,25(OH)2D2 and 1alpha,25(OH)2D7 were much less active than 1alpha,25(OH)2D3 in these respects. This is the first report concerning biological assessment of 1alpha,25(OH)2D2, 1alpha,25(OH)2D3, 1alpha,25(OH)2D4, 24-epi-1alpha,25(OH)2D2 and 1alpha,25(OH)2D7 at the molecular level, especially with regards to the structural differences at the 24R- or 24S-methyl group and a double bond between carbons 22 and 23 in the side chain of 1alpha,25(OH)2D derivatives. PMID:10328556

  1. Hypoxia-induced compensatory effect as related to Shh and HIF-1alpha in ischemia embryo rat heart.

    PubMed

    Hwang, Jin-Ming; Weng, Yi-Jiun; Lin, James A; Bau, Da-Tian; Ko, Fu-Yang; Tsai, Fuu-Jen; Tsai, Chang-Hai; Wu, Chieh-Hsi; Lin, Pei-Cheng; Huang, Chih-Yang; Kuo, Wei-Wen

    2008-04-01

    Chronic cardiac ischemia/hypoxia induces coronary collateral formation and cardiomyocyte proliferation. Hypoxia can induce cellular adaptive responses, such as synthesis of VEGF for angiogenesis and IGF-2 for proliferation. Both reduce apoptotic effects to minimize injury or damage. To investigate the mechanism of neoangiogenesis and proliferation of fetal heart under umbilical cord compression situation, we used H9c2 cardiomyoblast cell culture, and in vivo embryonic hearts as our study models. Results showed hypoxia induced not only the increase of IGF-2 and VEGF expression but also the activation of their upstream regulatory genes, HIF-1alpha and Shh. The relationship between HIF-1alpha and Shh was further studied by using cyclopamine and 2-ME2, inhibitor of Shh and HIF-1alpha signaling, respectively, in the cardiomyoblast cell culture under hypoxia. We found that the two inhibitors not only blocked their own signal pathway, but also inhibited each other. The observations revealed when fetal heart under hypoxia that HIF-1alpha and Shh pathways maybe involve in cell proliferation and neoangiogenesis to minimize injury or damage, whereas the complex cross-talk between the two pathways remains unknown. PMID:18228117

  2. Prostaglandin ethanolamides (prostamides): in vitro pharmacology and metabolism.

    PubMed

    Matias, I; Chen, J; De Petrocellis, L; Bisogno, T; Ligresti, A; Fezza, F; Krauss, A H-P; Shi, L; Protzman, C E; Li, C; Liang, Y; Nieves, A L; Kedzie, K M; Burk, R M; Di Marzo, V; Woodward, D F

    2004-05-01

    We investigated whether prostaglandin ethanolamides (prostamides) E(2), F(2alpha), and D(2) exert some of their effects by 1) activating prostanoid receptors either per se or after conversion into the corresponding prostaglandins; 2) interacting with proteins for the inactivation of the endocannabinoid N-arachidonoylethanolamide (AEA), for example fatty acid amide hydrolase (FAAH), thereby enhancing AEA endogenous levels; or 3) activating the vanilloid receptor type-1 (TRPV1). Prostamides potently stimulated cat iris contraction with potency approaching that of the corresponding prostaglandins. However, prostamides D(2), E(2), and F(2alpha) exhibited no meaningful interaction with the cat recombinant FP receptor, nor with human recombinant DP, EP(1-4), FP, IP, and TP prostanoid receptors. Prostamide F(2alpha) was also very weak or inactive in a panel of bioassays specific for the various prostanoid receptors. None of the prostamides inhibited AEA enzymatic hydrolysis by FAAH in cell homogenates, or AEA cellular uptake in intact cells. Furthermore, less than 3% of the compounds were hydrolyzed to the corresponding prostaglandins when incubated for 4 h with homogenates of rat brain, lung, or liver, and cat iris or ciliary body. Very little temperature-dependent uptake of prostamides was observed after incubation with rat brain synaptosomes or RBL-2H3 cells. We suggest that prostamides' most prominent pharmacological actions are not due to transformation into prostaglandins, activation of prostanoid receptors, enhancement of AEA levels, or gating of TRPV1 receptors, but possibly to interaction with novel receptors that seem to be functional in the cat iris. PMID:14757851

  3. Kinetic studies of 25-hydroxy-19-nor-vitamin D3 and 1 alpha,25-dihydroxy-19-nor-vitamin D3 hydroxylation by CYP27B1 and CYP24A1.

    PubMed

    Urushino, Naoko; Nakabayashi, Sachie; Arai, Midori A; Kittaka, Atsushi; Chen, Tai C; Yamamoto, Keiko; Hayashi, Keiko; Kato, Shigeaki; Ohta, Miho; Kamakura, Masaki; Ikushiro, Shinichi; Sakaki, Toshiyuki

    2007-09-01

    Our previous study demonstrated that 25-hydroxy-19-nor-vitamin D(3) [25(OH)-19-nor-D(3)] inhibited the proliferation of immortalized noncancerous PZ-HPV-7 prostate cells similar to 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)], suggesting that 25(OH)-19-nor-D(3) might be converted to 1 alpha,25-dihydroxy-19-nor-vitamin D(3) [1 alpha,25(OH)(2)-19-nor-D(3)] by CYP27B1 before exerting its antiproliferative activity. Using an in vitro cell-free model to study the kinetics of CYP27B1-dependent 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) and 25-hydroxyvitamin D(3) [25(OH)D(3)] and CYP24A1-dependent hydroxylation of 1 alpha,25(OH)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3), we found that k(cat)/K(m) for 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) was less than 0.1% of that for 25(OH)D(3), and the k(cat)/K(m) value for 24-hydroxylation was not significantly different between 1 alpha,25(OH)(2)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3). The data suggest a much slower formation and a similar rate of degradation of 1 alpha,25(OH)(2)-19-nor-D(3) compared with 1 alpha,25(OH)(2)D(3). We then analyzed the metabolites of 25(OH)D(3) and 25(OH)-19-nor-D(3) in PZ-HPV-7 cells by high-performance liquid chromatography. We found that a peak that comigrated with 1 alpha,25(OH)(2)D(3) was detected in cells incubated with 25(OH)D(3), whereas no 1 alpha,25(OH)(2)-19-nor-D(3) was detected in cells incubated with 25(OH)-19-nor-D(3). Thus, the present results do not support our previous hypothesis that 25(OH)-19-nor-D(3) is converted to 1 alpha,25(OH)(2)-19-nor-D(3) by CYP27B1 in prostate cells to inhibit cell proliferation. We hypothesize that 25(OH)-19-nor-D(3) by itself may have a novel mechanism to activate vitamin D receptor or it is metabolized in prostate cells to an unknown metabolite with antiproliferative activity without 1 alpha-hydroxylation. Thus, the results suggest that 25(OH)-19-nor-D(3) has potential as an attractive agent for prostate cancer therapy. PMID:17553915

  4. Hypoxia inducible factor-1 alpha and multiple myeloma

    PubMed Central

    Tiwary, Bhupendra Nath

    2016-01-01

    Rapid tumor growth creates a state of hypoxia in the tumor microenvironment and results in release of hypoxia inducible factor-1 alpha (HiF-1α) in the local milieu. Hypoxia inducible factor activity is deregulated in many human cancers, especially those that are highly hypoxic. In multiple myeloma (MM) in initial stages of disease establishment, the hypoxic bone marrow microenvironment supports the initial survival and growth of the myeloma cells. Hypoxic tumour cells are usually resistant to radiotherapy and most conventional chemotherapeutic agents, rendering them highly aggressive and metastatic. Therefore, HIF is an attractive, although challenging, therapeutic target in MM directly or indirectly in recent years. PMID:26900575

  5. Bone destruction mechanisms in chronic otitis media with cholesteatoma: specific production by cholesteatoma tissue in culture of bone-resorbing activity attributable to interleukin-1 alpha.

    PubMed

    Kurihara, A; Toshima, M; Yuasa, R; Takasaka, T

    1991-12-01

    To clarify specific mechanisms underlying cholesteatoma-induced bone destruction, surgical specimens of middle ear inflammatory granulation tissue with or without cholesteatoma were maintained in vitro and the bone-resorbing activity in their culture supernatants was analyzed by means of calcium release from mouse calvaria. Almost the same levels of bone-resorbing activity and prostaglandin (PG) E2 were found in the supernatants of both types of tissue. By contrast, aural polyp tissue yielded hardly any such activity or PGE2. Under the influence of indomethacin, however, only tissue with cholesteatoma produced considerable bone resorption activity, whereas PGE2 production was suppressed completely. Such activity in the cholesteatoma culture supernatant was not due to contamination of endotoxin and proved to be blocked by the introduction of anti-interleukin (IL)-1 alpha antibody into the calvarial assay system. Anti-IL-1 beta antibody had no effect on such activity. Interleukin-1 alpha was detected only in cholesteatoma tissue culture supernatants by means of enzyme-linked immunosorbent assay and by bioassay. These data suggest that the bone destruction in otitis media with cholesteatoma may be attributed to IL-1 alpha in addition to PGE2. PMID:1746847

  6. Human keratinocyte line HaCaT metabolizes 1alpha-hydroxyvitamin D3 and vitamin D3 to 1alpha,25-dihydroxyvitamin D3 (calcitriol).

    PubMed

    Lehmann, B; Pietzsch, J; Kämpf, A; Meurer, M

    1998-11-01

    Cultured human keratinocytes have the property to hydroxylate exogenous 25-hydroxyvitamin D3 (25OHD3) at the C-1alpha position thus producing 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3). In this study we investigated whether keratinocytes can also hydroxylate vitamin D3 and one of its metabolites at the C-25 position. We could demonstrate that HaCaT keratinocytes can metabolize 1alpha-hydroxyvitamin D3 (1alpha-OHD3) and vitamin D3 to 1alpha,25(OH)2D3. Identification of the generated product as 1alpha,25(OH)2D3 was based on its elution pattern in two different high performance liquid chromatography systems, on its specific binding in a calf thymus receptor assay and on its gas chromatography-mass spectrometry characteristics. The hydroxylation of vitamin D3 to 1alpha,25(OH)2D3 was dose- and time-dependent. Bovine serum albumin added up to 1.5% (w/v) to the culture medium greatly increased the hydroxylation rates. These results show that HaCaT cells have the capacity to hydroxylate vitamin D3 at the C-1/25 positions. The generation of endogenous 1alpha,25(OH)2D3 from vitamin D3 within the skin may indicate a novel pathway which is of importance for the regulation of epidermal cell growth and differentiation. PMID:9833978

  7. Two splice variants of the hypoxia-inducible factor HIF-1alpha as potential dimerization partners of ARNT2 in neurons.

    PubMed

    Drutel, G; Kathmann, M; Héron, A; Gros, C; Macé, S; Schwartz, J C; Arrang, J M

    2000-10-01

    The hypoxia-inducible factor (HIF-1alpha), a basic helix-loop-helix transcription factor, is known to heterodimerize with ARNT1, a nuclear translocator, to trigger the overexpression in many cells of genes involved in resistance to hypoxia. Although HIF-1alpha and ARNT1 are both expressed in brain, their cellular localization and function therein are unknown. Here, using in situ hybridization and immunocytochemistry, we show that HIF-1alpha is expressed in normoxic cerebral neurons together with not only ARNT1 but also ARNT2, a cerebral translocator homologous to ARNT1 but displaying, unlike ARNT1, a selective neuronal expression. In contrast, other potential partners of the translocators, i.e. the aryl hydrocarbon receptor (AHR) and the single-minded protein 2 (SIM2), are not expressed in the adult brain. We also identify two splice variants of HIF-1alpha in brain, one of which dimerizes with ARNT2 even more avidly than with ARNT1. The resulting heterodimer, in contrast with the HIF-1alpha/ARNT1 complex, does not recognize the HIF-1-binding site of the hypoxia-induced erythropoietin (Epo) gene, suggesting that it controls transcription of a distinct set of genes. We therefore propose that HIF-1alpha and ARNT2 function as preferential dimerization partners in neurons to control specific responses, some of which may not be triggered by hypoxia. In support of this proposal, in nonhypoxic PC12 cells constitutively coexpressing HIF-1alpha, ARNT1 and ARNT2, downregulation of either HIF-1alpha or ARNT2, obtained with selective antisense nucleotides, resulted in inhibition of [3H]thymidine incorporation. PMID:11029639

  8. Transcription Factor Tfe3 Directly Regulates Pgc-1alpha in Muscle

    PubMed Central

    SALMA, NUNCIADA; SONG, JUN S.; ARANY, ZOLTAN; FISHER, DAVID E.

    2015-01-01

    The microphthalmia (MiT) family of transcription factors is an important mediator of metabolism. Family members Mitf and Tfeb directly regulate the expression of the master regulator of metabolism, peroxisome-proliferator activated receptor gamma coactivator-1 alpha (Pgc-1alpha), in melanomas and in the liver, respectively. Pgc-1alpha is enriched in tissues with high oxidative capacity and plays an important role in the regulation of mitochondrial biogenesis and cellular metabolism. In skeletal muscle, Pgc-1alpha affects many aspects of muscle functionally such as endurance, fiber-type switching, and insulin sensitivity. Tfe3 also regulates muscle metabolic genes that enhance insulin sensitivity in skeletal muscle. Tfe3 has not yet been shown to regulate Pgc-1alpha expression. Our results reported here show that Tfe3 directly regulates Pgc-1alpha expression in myotubes. Tfe3 ectopic expression induces Pgc-1alpha, and Tfe3 silencing suppresses Pgc-1alpha expression. This regulation is direct, as shown by Tfe3’s binding to E-boxes on the Pgc-1alpha proximal promoter. We conclude that Tfe3 is a critical transcription factor that regulates Pgc-1alpha gene expression in myotubes. Since Pgc-1alpha coactivates numerous biological programs in diverse tissues, the regulation of its expression by upstream transcription factors such Tfe3 implies potential opportunities for the treatment of diseases where modulation of Pgc-1alpha expression may have important clinical outcomes. PMID:25736533

  9. Fenamates may antagonize the actions of prostaglandin endoperoxides in human myometrium.

    PubMed Central

    Sanger, G J; Bennett, A

    1979-01-01

    1 The prostaglandin endoperoxide analogue U-46619 potently contracted human isolated myometrium, suggesting that prostaglandin H2 (PGH2) may be a major stimulant of myometrial contractions. 2 Sodium mefenamate, flufenamate or meclofenamate 2 microgram/ml greatly reduced contractions of the myometrium induced by the PGH2 analogue. 3 Flufenamate, but not the other two drugs, also significantly inhibited contractions to acetylcholine. 4 Sodium meclofenamate 2 microgram/ml did not consistently antagonize contractions to PGF2alpha. 5 The relief of dysmenorrhoea by fenamates may be explained both by inhibition of PG synthesis, and by antagonism of contractions to PGH2 produced by incompletely blocked PG synthesis. PMID:508555

  10. Different effect of prostaglandin E2 on B-cell activation by two distinct B-cell differentiation factors, B151-TRF1/IL-5 and B151-TRF2: selective inhibition of B151-TRF2-induced antibody response through increases in intracellular cyclic AMP levels

    PubMed Central

    Ishihara, K.; Ono, S.; Takahama, Y.; Hirayama, F.; Hirano, H.; Itoh, K.; Dobashi, K.; Murakami, S.; Katoh, Y.; Yamaguchi, M.; Hamaoka, T.

    1989-01-01

    Effects of prostaglandin E2 (PGE2) on murine B-cell activation induced by two distinct B-cell differentiation factors, B151-TRF1/IL-5 and B151-TRF2, were examined. A final differentiation of unprimed B cells into IgM-producing cells induced by B151-TRF2 was markedly inhibited by PGE2 at physiological concentrations (around 10-8 M), whereas B151-TRF1/IL-5-induced antibody responses of unprimed as well as activated B cells were not affected by PGE2, even at 10-6 M. B-cell responses induced by B151-TRF2-like factors from autoimmune-prone MRL/1pr mice were also inhibited by PGE2. Biphasic increases in intracellular cyclic AMP (cAMP) levels were induced by culturing B cells with 10-6 or 10-8 M PGE2: rapid increases within 8 min and delayed increases around 16 hr. The direct addition of dibutyryl cAMP to cultures of B cells resulted in marked inhibition of antibody responses when stimulated with B151-TRF2 but not with B151-TRF1/IL-5. The B151-TRF2-induced antibody responses were also inhibited by cAMP-elevating reagents such as forskolin, cholera toxin and theophyline. Furthermore, 2′, 5′-dideoxyadenosine, which is an inhibitor of adenylate cyclase, prevented the PGE2-mediated cAMP accumulation in unprimed B cells as well as the PGE2-mediated inhibition of B151-TRF2-induced B-cell responses when added at the initiation of culture. These results suggest that PGE2 inhibits B151-TRF2-induced antibody responses through the activation of adenylate cyclase and subsequent accumulation of intracellular cAMP, whereas B151-TRF1/IL-5-responsive B cells are resistant to the inhibitory effect of PGE2 and cAMP. PMID:2553585

  11. Coronary flow regulation in patients with ischemic heart disease: release of purines and prostacyclin and the effect of inhibitors of prostaglandin formation.

    PubMed

    Edlund, A; Berglund, B; van Dorne, D; Kaijser, L; Nowak, J; Patrono, C; Sollevi, A; Wennmalm, A

    1985-06-01

    The present investigation was undertaken to study cardiac release of adenosine and prostacyclin (prostaglandin [PG] I2) in patients with ischemic heart disease (IHD), and to assess coronary vascular resistance before and after inhibition of synthesis in such patients. In 48 patients with IHD, arterial and coronary sinus blood samples were taken at rest, during atrial pacing to angina, and after pacing. Levels of purines were determined by high-performance liquid chromatography and the PGI2 metabolite 6-keto-PGF1 alpha was measured with radioimmunoassay. Coronary sinus blood flow was determined with retrograde continuous thermodilution before and after oral administration of indomethacin, aspirin, naproxen, or ibuprofen. Atrial pacing induced myocardial ischemia, as evidenced by typical chest pain and arrested lactate extraction. Adenosine was extracted at rest, but during ischemia there was a significant release of its metabolite hypoxanthine, indicating increased myocardial breakdown of high-energy adenine nucleotides. Arterial and coronary sinus concentrations of 6-keto-PGF1 alpha were low and no significant differences between them were found. After administration of the PG-synthesis inhibitor indomethacin, coronary vascular resistance was elevated, as was the cardiac oxygen extraction. The three other PG-synthesis inhibitors (aspirin, naproxen, and ibuprofen) did not, however, induce any change in coronary vascular resistance or in the cardiac extraction of oxygen. On the basis of these data we suggest that in patients with IHD cardiac ischemia results in increased myocardial production and release of purines, cardiac ischemia does not elicit any detectable increase in coronary production of prostacyclin, and the increased coronary resistance induced by indomethacin does not reflect the involvement of locally formed PG in the maintenance of coronary flow, but is rather a direct effect of the drug. PMID:3888437

  12. Prostaglandin dehydrogenase and the initiation of labor.

    PubMed

    Challis, J R; Patel, F A; Pomini, F

    1999-01-01

    In summary, these studies have suggested that prostaglandin dehydrogenase may have a central role to play in the mechanisms which determine biologically active prostaglandin concentrations within human fetal membranes and placenta at the time of labor, at term or preterm. Moreover, our studies indicate that the regulation of PGDH may by multifactorial (figure 3). In certain regions of the membranes, we suggest that PGDH expression may be influenced by levels of anti-inflammatory and pro-inflammatory cytokines. In other regions of the membranes, we suggest that PGDH may be regulated at a transcriptional level by competing activities of progesterone and cortisol. The action of progesterone could be effected through systemically-derived steroid, or by locally synthesized steroid, acting in a paracrine and/or autocrine fashion. The effects of cortisol in placenta must be due to glucocorticoid derived from the maternal or fetal compartment, since the placenta lacks the hydroxylases required for endogenous cortisol production. However, metabolism of cortisol by 11 beta-HSD-2 reduces the potency of this glucocorticoid in placental tissue. In chorion however, cortisol may be formed locally, from cortisone, in addition to its being derived from the maternal circulation and/or from the amniotic fluid. Our current studies do not allow us to delineate whether the effects of progesterone and cortisol on PGDH are exerted through the glucocorticoid receptor (GR) or progesterone receptor (PR) or both. It is possible that through pregnancy, PGDH activity is maintained by progesterone acting either through low levels of PR in membranes, or, more likely, acting through GR. At term, elevated levels of cortisol compete with and displace progesterone from GR, resulting in inhibition of PGDH transcription and activity. In this way, local withdrawal of progesterone action would be effected within human intrauterine tissues, without requiring changes in systemic, circulating progesterone

  13. The Enteropathy of Prostaglandin Deficiency

    PubMed Central

    Adler, David H.; Phillips, John A.; Cogan, Joy D.; Iverson, Tina M.; Stein, Jeffrey A.; Brenner, David A.; Morrow, Jason D.; Boutaud, Olivier; Oates, John A.

    2009-01-01

    Purpose Small intestinal ulcers are frequent complications of therapy with non-steroidal anti-inflammatory drugs (NSAIDs). We present here a genetic deficiency of eicosanoid biosynthesis that illuminates the mechanism of NSAID-induced ulcers of the small intestine. Methods Eicosanoids and metabolites were measured by isotope-dilution with mass spectrometry. cDNA was obtained by reverse transcription and sequenced following amplification with RT-PCR. Results We investigated the cause of chronic recurrent small intestinal ulcers, small bowel perforations, and gastrointestinal blood loss in a 45 year old male who was not taking any cyclooxygenase inhibitor. Prostaglandin metabolites in urine were significantly depressed. Serum thromboxane B2 (TxB2) production was 4.6% of normal controls (p<0.006) and serum 12-HETE was 1.3% of controls (p<0.005). Optical platelet aggregation with simultaneous monitoring of ATP release demonstrated absent granule secretion in response to ADP and a blunted aggregation response to ADP and collagen, but normal response to arachidonic acid (AA). LTB4 biosynthesis by ionophore activated leukocytes was only 3% of controls and urinary LTE4 was undetectable. These findings suggested deficient AA release from membrane phospholipids by cytosolic phospholipase A2-α (cPLA2-α) which regulates cyclooxygenase and lipoxygenase mediated eicosanoid production by catalyzing the release of their substrate, AA. Sequencing of cPLA2-α cDNA demonstrated 2 heterozygous non-synonymous single base pair mutations: Ser111Pro (S111P) and Arg485His (R485H), as well as a known SNP: Lys651Arg (K651R). Conclusion Characterization of this cPLA2-α deficiency provides support for the importance of prostaglandins in protecting small intestinal integrity, and indicates that loss of prostaglandin biosynthesis is sufficient to produce small intestinal ulcers. PMID:19148786

  14. Major vault protein forms complexes with hypoxia-inducible factor (HIF)-1alpha and reduces HIF-1alpha level in ACHN human renal adenocarcinoma cells.

    PubMed

    Iwashita, Ken-ichi; Ikeda, Ryuji; Takeda, Yasuo; Sumizawa, Tomoyuki; Furukawa, Tatsuhiko; Yamaguchi, Tatsuya; Akiyama, Shin-ichi; Yamada, Katsushi

    2010-04-01

    Vaults are evolutionarily highly conserved ribonucleoprotein (RNP) particles with a hollow barrel-like structure. Although roles in multidrug resistance and innate immunity have been suggested, the physiological function of vaults remains unclear. Major vault protein (MVP), the main component of the vault particle, has been reported to be induced by hypoxia. However, there are no reports about the effect of vaults on cellular responses to hypoxia. We thus examined whether vaults are implicated in cellular responses to hypoxia. In this study, we focused on hypoxia-inducible factor-1alpha (HIF-1alpha), which is a master regulator of hypoxic responses, and found that: (i) MVP knockdown by RNA interference increases HIF-1alpha protein levels induced by hypoxia and hypoxia mimetics; (ii) MVP knockdown does not affect HIF-1alpha mRNA levels, but decreases the ubiquitination and degradation of HIF-1alpha protein; and (iii) vaults form complexes with HIF-1alpha, PHD2, and pVHL. Taken together, these results suggest that vaults function as scaffolds in HIF-1alpha degradation pathway and promote the ubiquitination and degradation of HIF-1alpha. PMID:20175781

  15. The current status of prostaglandins as abortifacients.

    PubMed

    Brenner, W E

    1975-10-01

    The present use and potential uses of prostaglandins as abortifacients are summarized. Pertinent history, chemistry, prostaglandins' possible role in physiologic and pathologic processes and pharmacologic actions are discussed. The results of natural prostaglandins and their analogues by systemic and intrauterine administration for the purposes of postcoital contraception, menstrual regulation, first- and second-trimester abortion, preoperative dilation of the cervix, and delivery of patients with death in utero are presented. The only approved method of induction of abortion with prostaglandins, prostaglandin F2alpha by the intra-amniotic route for the induction of midtrimester abortion, is evaluated and compared to other methods of midtrimester abortion. It was concluded that: (1) the present use of prostaglandins is an important addition to the obstetrician's armamentarium, (2) more effective and/or convenient methods that are useful in patients over a wider gestational age appear to have been defined, and (3) the routine use of prostaglandins for postcoital contraception, menstrual regulation, and first-trimester abortion will require the development of analogues that are more specific as to their abortifacient actions than the natural prostaglandins and/or the development of improved delivery systems. PMID:810025

  16. Regulation of activator protein-1 by 8-iso-prostaglandin E2 in a thromboxane A2 receptor-dependent and -independent manner

    SciTech Connect

    Weber, Thomas J.; Markillie, Lye MENG.

    2003-05-01

    The thromboxane (TX) A{sub 2} receptor (TP) encompasses two alternatively spliced forms, termed the platelet/placental (TP-P) and endothelial (TP-E) type receptors. Experimental evidence suggests that TP activity may be modulated by novel ligands, termed the isoprostanes, that paradoxically act as TP agonists in smooth muscle and TP antagonists in platelet preparations. Here we have investigated whether prototypical isoprostanes 8-iso-prostaglandin (PG)F{sub 2{alpha}} and 8-iso-PGE{sub 2} regulate the activity of TP isoforms expressed in Chinese hamster ovary (CHO) cells using activator protein-1 (AP-1)-luciferase activity as a reporter. AP-1-luciferase activity was increased by a TP agonist [9,11-dideoxy-9{alpha},11{alpha}-methanoepoxy PGF{sub 2{alpha}} (U46619)] in CHO cells transfected with the human TP-P and TP-E receptors, and this response was fully inhibited by TP antagonists [1S-[1{alpha},2{beta}(Z),3{alpha},5{alpha}

  17. Inhibition of Prostaglandin Reductase 2, a Putative Oncogene Overexpressed in Human Pancreatic Adenocarcinoma, Induces Oxidative Stress-Mediated Cell Death Involving xCT and CTH Gene Expressions through 15-Keto-PGE2

    PubMed Central

    Chang, Emily Yun-Chia; Chang, Yi-Cheng; Shun, Chia-Tung; Tien, Yu-Wen; Tsai, Shu-Huei; Hee, Siow-Wey; Chen, Ing-Jung; Chuang, Lee-Ming

    2016-01-01

    Prostaglandin reductase 2 (PTGR2) is the enzyme that catalyzes 15-keto-PGE2, an endogenous PPARγ ligand, into 13,14-dihydro-15-keto-PGE2. Previously, we have reported a novel oncogenic role of PTGR2 in gastric cancer, where PTGR2 was discovered to modulate ROS-mediated cell death and tumor transformation. In the present study, we demonstrated the oncogenic potency of PTGR2 in pancreatic cancer. First, we observed that the majority of the human pancreatic ductal adenocarcinoma tissues was stained positive for PTGR2 expression but not in the adjacent normal parts. In vitro analyses showed that silencing of PTGR2 expression enhanced ROS production, suppressed pancreatic cell proliferation, and promoted cell death through increasing 15-keto-PGE2. Mechanistically, silencing of PTGR2 or addition of 15-keto-PGE2 suppressed the expressions of solute carrier family 7 member 11 (xCT) and cystathionine gamma-lyase (CTH), two important providers of intracellular cysteine for the generation of glutathione (GSH), which is widely accepted as the first-line antioxidative defense. The oxidative stress-mediated cell death after silencing of PTGR2 or addition of 15-keto-PGE2 was further abolished after restoring intracellular GSH concentrations and cysteine supply by N-acetyl-L-cysteine and 2-Mercaptomethanol. Our data highlight the therapeutic potential of targeting PTGR2/15-keto-PGE2 for pancreatic cancer. PMID:26820738

  18. Inhibition of Prostaglandin Reductase 2, a Putative Oncogene Overexpressed in Human Pancreatic Adenocarcinoma, Induces Oxidative Stress-Mediated Cell Death Involving xCT and CTH Gene Expressions through 15-Keto-PGE2.

    PubMed

    Chang, Emily Yun-Chia; Chang, Yi-Cheng; Shun, Chia-Tung; Tien, Yu-Wen; Tsai, Shu-Huei; Hee, Siow-Wey; Chen, Ing-Jung; Chuang, Lee-Ming

    2016-01-01

    Prostaglandin reductase 2 (PTGR2) is the enzyme that catalyzes 15-keto-PGE2, an endogenous PPARγ ligand, into 13,14-dihydro-15-keto-PGE2. Previously, we have reported a novel oncogenic role of PTGR2 in gastric cancer, where PTGR2 was discovered to modulate ROS-mediated cell death and tumor transformation. In the present study, we demonstrated the oncogenic potency of PTGR2 in pancreatic cancer. First, we observed that the majority of the human pancreatic ductal adenocarcinoma tissues was stained positive for PTGR2 expression but not in the adjacent normal parts. In vitro analyses showed that silencing of PTGR2 expression enhanced ROS production, suppressed pancreatic cell proliferation, and promoted cell death through increasing 15-keto-PGE2. Mechanistically, silencing of PTGR2 or addition of 15-keto-PGE2 suppressed the expressions of solute carrier family 7 member 11 (xCT) and cystathionine gamma-lyase (CTH), two important providers of intracellular cysteine for the generation of glutathione (GSH), which is widely accepted as the first-line antioxidative defense. The oxidative stress-mediated cell death after silencing of PTGR2 or addition of 15-keto-PGE2 was further abolished after restoring intracellular GSH concentrations and cysteine supply by N-acetyl-L-cysteine and 2-Mercaptomethanol. Our data highlight the therapeutic potential of targeting PTGR2/15-keto-PGE2 for pancreatic cancer. PMID:26820738

  19. Effects of pressure overload and insulin on protein turnover in the perfused rat heart. Prostaglandins are not involved although their synthesis is stimulated by insulin.

    PubMed Central

    Smith, D M; Sugden, P H

    1987-01-01

    A modified anterogradely perfused rat heart preparation is described in which all the cardiac output passes through the coronary circulation. Such a preparation develops hypertensive aortic pressures. Hypertensive aortic pressures or insulin stimulate the rate of cardiac protein synthesis and inhibit the rate of protein degradation. Aortic pressure and insulin may be important in the regulation of cardiac nitrogen balance in vivo. By abolishing cardiac prostaglandin synthesis with 4-biphenylacetate, we were able to investigate the possible involvement of prostaglandins in the modulation of protein turnover by pressure overload or insulin. There was no evidence of any involvement. However, insulin stimulated and cycloheximide inhibited cardiac prostaglandin synthesis. These findings are consonant with an enzyme involved in prostaglandin synthesis being short-lived and prostaglandin synthesis being rapidly influenced by activators and inhibitors of protein synthesis and degradation. PMID:3307762

  20. Chemokines, macrophage inflammatory protein-2 and stromal cell-derived factor-1{alpha}, suppress amyloid {beta}-induced neurotoxicity

    SciTech Connect

    Raman, Dayanidhi; Milatovic, Snjezana-Zaja; Milatovic, Dejan; Fan, Guo-Huang; Richmond, Ann

    2011-11-15

    Alzheimer's disease (AD) is characterized by a progressive cognitive decline and accumulation of neurotoxic oligomeric peptides amyloid-{beta} (A{beta}). Although the molecular events are not entirely known, it has become evident that inflammation, environmental and other risk factors may play a causal, disruptive and/or protective role in the development of AD. The present study investigated the ability of the chemokines, macrophage inflammatory protein-2 (MIP-2) and stromal cell-derived factor-1{alpha} (SDF-1{alpha}), the respective ligands for chemokine receptors CXCR2 and CXCR4, to suppress A{beta}-induced neurotoxicity in vitro and in vivo. Pretreatment with MIP-2 or SDF-1{alpha} significantly protected neurons from A{beta}-induced dendritic regression and apoptosis in vitro through activation of Akt, ERK1/2 and maintenance of metalloproteinase ADAM17 especially with SDF-1{alpha}. Intra-cerebroventricular (ICV) injection of A{beta} led to reduction in dendritic length and spine density of pyramidal neurons in the CA1 area of the hippocampus and increased oxidative damage 24 h following the exposure. The A{beta}-induced morphometric changes of neurons and increase in biomarkers of oxidative damage, F{sub 2}-isoprostanes, were significantly inhibited by pretreatment with the chemokines MIP-2 or SDF-1{alpha}. Additionally, MIP-2 or SDF-1{alpha} was able to suppress the aberrant mislocalization of p21-activated kinase (PAK), one of the proteins involved in the maintenance of dendritic spines. Furthermore, MIP-2 also protected neurons against A{beta} neurotoxicity in CXCR2-/- mice, potentially through observed up regulation of CXCR1 mRNA. Understanding the neuroprotective potential of chemokines is crucial in defining the role for their employment during the early stages of neurodegeneration. -- Research highlights: Black-Right-Pointing-Pointer Neuroprotective ability of the chemokines MIP2 and CXCL12 against A{beta} toxicity. Black-Right-Pointing-Pointer MIP-2 or

  1. Studies on the 1alpha, 25-dihydroxycholecalciferol-like activity in a calcinogenic plant. Cestrum diurnum, in the chick.

    PubMed

    Wasserman, R H; Corradino, R A; Krook, L; Hughes, M R; Haussler, M R

    1976-04-01

    Cestrum diurnum (day-blooming jessamine) has been proposed to cause calcinosis in horses and cattle in Florida. The present studies investigated some physiological properties of the plant, using the chick as the experimental animal. The inclusion of dried leaf powder in a rachitogenic diet restored intestinal calcium-binding protein synthesis (CaBP) and increased calcium absorption in the cholecalciferol-deficient chick. The estimated level of cholecalciferol-equivalents in the dried leaf was about 30,000 to 35,000 IU/kg. Most of the activity was extractable with methanol:chloroform (2:1), indicating that the major cholecalciferol-like component in C. diurnum was different from the water soluble factor(s) in Solanum malacoxylon. The time course of effect of C. diurnum extract in rachitic chicks was similar to that ot 1,25-dihydroxycholecalciferol but the former had a longer lag time. The strontium fed chick, in which the kidney 25-hydroxycholecalciferol-1alpha-hydroxylase is inhibited, responded to C. diurnum extract, confirming the 1alpha,25-dihydroxycholecalciferol-like character of the Cestrum factor. The extract also appeared to interact with the intestinal 1 alpha,25-dihydroxycholecalciferol cytosol receptor although this observation is preliminary. These findings indicate that the l alpha,25-dihydroxycholecalciferol-like principle in C. diurnum many cause excessive calcium and phosphate absorption leading to calcinosis. PMID:1255265

  2. Prostaglandin synthesis inhibitors block alcohol-induced fetal hypoplasia.

    PubMed

    Pennington, S; Allen, Z; Runion, J; Farmer, P; Rowland, L; Kalmus, G

    1985-01-01

    Alcohol-induced growth retardation is a fetal effect consistently associated with maternal ethanol consumption. In humans, those infants whose mothers consume even a limited amount of ethanol during pregnancy have a significant incidence of growth inhibition. The molecular mechanism responsible for this growth deficiency is unknown, and prevention depends on maternal abstinence during pregnancy. The data reported here suggest that ethanol-mediated increases in tissue prostaglandin (PG) E levels (PGE1 plus PGE2) are correlated with the growth retardation. Further, simultaneous administration of PG synthesis inhibitors with the alcohol blocks the rise in tissue PG levels and protects against the alcohol-induced hypoplasia. PMID:3904508

  3. The Role of Prostaglandins and COX-Enzymes in Chondrogenic Differentiation of ATDC5 Progenitor Cells

    PubMed Central

    Caron, Marjolein M. J.; Emans, Pieter J.; Sanen, Kathleen; Surtel, Don A. M.; Cremers, Andy; Ophelders, Daan; van Rhijn, Lodewijk W.; Welting, Tim J. M.

    2016-01-01

    Objectives NSAIDs are used to relieve pain and decrease inflammation by inhibition of cyclooxygenase (COX)-catalyzed prostaglandin (PG) synthesis. PGs are fatty acid mediators involved in cartilage homeostasis, however the action of their synthesizing COX-enzymes in cartilage differentiation is not well understood. In this study we hypothesized that COX-1 and COX-2 have differential roles in chondrogenic differentiation. Methods ATDC5 cells were differentiated in the presence of COX-1 (SC-560, Mofezolac) or COX-2 (NS398, Celecoxib) specific inhibitors. Specificity of the NSAIDs and inhibition of specific prostaglandin levels were determined by EIA. Prostaglandins were added during the differentiation process. Chondrogenic outcome was determined by gene- and protein expression analyses. Results Inhibition of COX-1 prevented Col2a1 and Col10a1 expression. Inhibition of COX-2 resulted in decreased Col10a1 expression, while Col2a1 remained unaffected. To explain this difference expression patterns of both COX-enzymes as well as specific prostaglandin concentrations were determined. Both COX-enzymes are upregulated during late chondrogenic differentiation, whereas only COX-2 is briefly expressed also early in differentiation. PGD2 and PGE2 followed the COX-2 expression pattern, whereas PGF2α and TXA2 levels remained low. Furthermore, COX inhibition resulted in decreased levels of all tested PGs, except for PGD2 and PGF2α in the COX-1 inhibited condition. Addition of PGE2 and PGF2α resulted in increased expression of chondrogenic markers, whereas TXA2 increased expression of hypertrophic markers. Conclusions Our findings point towards a differential role for COX-enzymes and PG-production in chondrogenic differentiation of ATDC5 cells. Ongoing research is focusing on further elucidating the functional partition of cyclooxygenases and specific prostaglandin production. PMID:27050768

  4. Binding of RANTES, MCP-1, MCP-3, and MIP-1alpha to cells in human skin.

    PubMed Central

    Hub, E.; Rot, A.

    1998-01-01

    Based on their ability to induce leukocyte chemotaxis and adhesion to endothelial cells (ECs), chemokines have been implicated in driving inflammatory leukocyte emigration. Recently, it was suggested that chemokines can accomplish their pro-emigratory role more effectively while being bound to the luminal surface of the ECs. Previously, such binding was demonstrated in situ in human skin for the prototype alpha-chemokine interleukin (IL)-8. Here we used an in situ binding assay to investigate the binding characteristics of several beta-chemokines in intact human skin. RANTES, MCP-1, and MCP-3 bound, similar to IL-8, in a specific saturable manner to the ECs of venules and small veins but not arteries or capillaries. RANTES inhibited MCP-1 and MCP-3 binding and vice versa, indicating that the EC binding sites are shared among these beta-chemokines; moreover, IL-8 and RANTES cross-competed for each other's binding, suggesting that the same chemokine binding sites are used by members of alpha- and beta-chemokine subfamilies. Conversely, MIP-1alpha did not bind to the ECs and did not compete for binding of RANTES. Analogous to IL-8, all of the tested beta-chemokines bound to the resident dermal cells. As a novel aspect of chemokine interaction with cells in normal skin, we observed specific, saturable binding of RANTES, MCP-1, and MCP-3 but not MIP-1alpha or IL-8 to the ECs of dermal afferent lymphatic vessels. RANTES, MCP-1, and MCP-3 also cross-competed for each other's binding to lymphatics, suggesting a common binding site with a novel chemokine binding profile. We suggest that the chemokine binding to the ECs of lymphatics may be involved in the process of leukocyte entry into the afferent lymphatic vessels. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9502417

  5. Imatinib resistance associated with BCR-ABL upregulation is dependent on HIF-1alpha-induced metabolic reprograming.

    PubMed

    Zhao, F; Mancuso, A; Bui, T V; Tong, X; Gruber, J J; Swider, C R; Sanchez, P V; Lum, J J; Sayed, N; Melo, J V; Perl, A E; Carroll, M; Tuttle, S W; Thompson, C B

    2010-05-20

    As chronic myeloid leukemia (CML) progresses from the chronic phase to blast crisis, the levels of BCR-ABL increase. In addition, blast-transformed leukemic cells display enhanced resistance to imatinib in the absence of BCR-ABL-resistance mutations. In this study, we show that when BCR-ABL-transformed cell lines were selected for imatinib resistance in vitro, the cells that grew out displayed a higher BCR-ABL expression comparable to the increase seen in accelerated forms of the disease. This enhanced expression of BCR-ABL was associated with an increased rate of glycolysis but with a decreased rate of proliferation. The higher level of BCR-ABL expression in the selected cells correlated with a nonhypoxic induction of hypoxia-inducible factor-1alpha (HIF-1alpha) that was required for cells to tolerate enhanced BCR-ABL signaling. HIF-1alpha induction resulted in an enhanced rate of glycolysis but with reduced glucose flux through both the tricarboxylic acid cycle and the oxidative arm of the pentose phosphate pathway (PPP). The reduction in oxidative PPP-mediated ribose synthesis was compensated by the HIF-1alpha-dependent activation of the nonoxidative PPP enzyme, transketolase, in imatinib-resistant CML cells. In both primary cultures of cells from patients exhibiting blast transformation and in vivo xenograft tumors, use of oxythiamine, which can inhibit both the pyruvate dehydrogenase complex and transketolase, resulted in enhanced imatinib sensitivity of tumor cells. Together, these results suggest that oxythiamine can enhance imatinib efficacy in patients who present an accelerated form of the disease. PMID:20228846

  6. Levels of eicosanoids (6-oxo-PGF1 alpha and 8-epi-PGF2 alpha) in human and porcine lymphatics and lymph.

    PubMed

    Oguogho, A; Kaliman, J; Sinzinger, H

    1998-12-01

    Prostaglandin (PG)I2 is the primary eicosanoid synthesized by human lymphatics and 8-epi-PGF2 alpha, an isoprostane formed during free radical catalyzed peroxidation, is the most potent stimulator of lymphatic contraction tested thus far. We now examine the respective concentrations in the lymphatic wall of both human and porcine lymphatics and lymph fluid using specific immunoassays. Although both compounds are detectable in the lymphatic wall and lymph fluid, PGI2- (via its main metabolite 6-oxo-PGF1 alpha) is greater in the lymphatic wall whereas 8-epi-PGF2 alpha dominates in lymph fluid. Because inflammation is associated with oxidative injury, which in turn stimulates release of isoprostane, eicosanoid derivatives may modulate lymphatic tone during acute tissue reaction. PMID:9949390

  7. Identification of novel targets for PGC-1{alpha} and histone deacetylase inhibitors in neuroblastoma cells

    SciTech Connect

    Cowell, Rita M. Talati, Pratik; Blake, Kathryn R.; Meador-Woodruff, James H.; Russell, James W.

    2009-02-06

    Recent evidence suggests that the transcriptional coactivator peroxisome proliferator activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) is involved in the pathology of Huntington's Disease (HD). While animals lacking PGC-1{alpha} express lower levels of genes involved in antioxidant defense and oxidative phosphorylation in the brain, little is known about other targets for PGC-1{alpha} in neuronal cells and whether there are ways to pharmacologically target PGC-1{alpha} in neurons. Here, PGC-1{alpha} overexpression in SH-SY5Y neuroblastoma cells upregulated expression of genes involved in mitochondrial function, glucose transport, fatty acid metabolism, and synaptic function. Overexpression also decreased vulnerability to hydrogen peroxide-induced cell death and caspase 3 activation. Treatment of cells with the histone deacetylase inhibitors (HDACi's) trichostatin A and valproic acid upregulated PGC-1{alpha} and glucose transporter 4 (GLUT4). These results suggest that PGC-1{alpha} regulates multiple pathways in neurons and that HDACi's may be good candidates to target PGC-1{alpha} and GLUT4 in HD and other neurological disorders.

  8. Melittin stimulates liver glycogenolysis and the release of prostaglandin D2 and thromboxane B2.

    PubMed Central

    García-Sáinz, J A; Hernández-Sotomayor, S M; Macías-Silva, M

    1990-01-01

    Melittin stimulates glycogenolysis and induces vasoconstriction in perfused rat liver. The effect was rapid and associated with production and release of prostaglandin D2 and thromboxane B2. Indomethacin blocked the release of these eicosanoids and the stimulation of glycogenolysis induced by melittin. Ibuprofen blocked the release of prostaglandin D2 induced by melittin and markedly attenuated that of thromboxane B2. Interestingly, the initial burst of glucose output induced by melittin was not inhibited by ibuprofen, although the duration of the glycogenolytic action of the peptide was greatly diminished. PMID:2375756

  9. Inhibition of estrogen receptor {beta}-mediated human telomerase reverse transcriptase gene transcription via the suppression of mitogen-activated protein kinase signaling plays an important role in 15-deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2}-induced apoptosis in cancer cells

    SciTech Connect

    Kondoh, Kei; Tsuji, Naoki; Asanuma, Koichi; Kobayashi, Daisuke; Watanabe, Naoki

    2007-10-01

    The nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR)-{gamma} plays a role in cancer development in addition to its role in glucose metabolism. The natural ligand of PPAR-{gamma}, namely, 15-deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2} (15d-PGJ{sub 2}), has been shown to possess antineoplastic activity in cancer cells. However, the mechanism underlying its antineoplastic activity remains to be elucidated. Inhibition of the expression of human telomerase reverse transcriptase (hTERT), a major determinant of telomerase activity, reportedly induces rapid apoptosis in cancer cells. In this study, we investigated the effect of 15d-PGJ{sub 2} on hTERT expression. We found that 15d-PGJ{sub 2} induced apoptosis in the MIAPaCa-2 pancreatic cancer cells and dose-dependently decreased hTERT mRNA and protein expression. Down-regulation of hTERT expression by hTERT-specific small inhibitory RNA also induced apoptosis. Furthermore, 15d-PGJ{sub 2} attenuated the DNA binding of estrogen receptor (ER). MIAPaCa-2 expressed only ER{beta}, and although its expression did not decrease due to 15d-PGJ{sub 2}, its phosphorylation was suppressed. Additionally, a mitogen-activated protein kinase (MAPK) kinase inhibitor decreased ER{beta} phosphorylation, and 15d-PGJ{sub 2} attenuated MAPK activity. We conclude that hTERT down-regulation by 15d-PGJ{sub 2} plays an important role in the proapoptotic property of the latter. Furthermore, 15d-PGJ{sub 2} inhibits ER{beta}-mediated hTERT gene transcription by suppressing ER{beta} phosphorylation via the inhibition of MAP kinase signaling.

  10. Prostaglandin F{sub 2{alpha}} regulates cytokine responses of mast cells through the receptors for prostaglandin E

    SciTech Connect

    Kaneko, Izumi; Hishinuma, Takanori; Suzuki, Kaori; Owada, Yuji; Kitanaka, Noriko; Kondo, Hisatake; Goto, Junichi; Furukawa, Hiroshi; Ono, Masao

    2008-03-14

    There is an increasing body of evidence that prostanoids modulate mast cell functions and contribute to the development of allergic inflammation. The present study aimed to identify an undetermined function of prostaglandin (PG) F{sub 2{alpha}} in mast cell activation and the signaling mechanism involved in it. Simultaneous quantification of prostanoids by liquid chromatography/tandem mass spectrometry revealed the constitutive release of PGF{sub 2{alpha}}, thromboxane B{sub 2}, and 6-keto-PGF{sub 1{alpha}} from bone marrow-derived mast cells (BMMCs). Upon activation of BMMCs by lipopolysaccharide, the cytokine production in BMMCs was enhanced when the culture was supplemented with PGF{sub 2{alpha}}. However, F prostanoid receptor-a selective receptor for PGF{sub 2{alpha}}-was not detected in BMMCs. Further investigations performed using prostanoid receptor antagonists revealed an alternative mechanism wherein the receptors for PGE species-E prostanoid receptors-mediated the PGF{sub 2{alpha}} signal in BMMCs. The present study provides an insight into a novel function of PGF{sub 2{alpha}}, i.e., an autocrine accelerator for mast cell activation.

  11. Crystal structure of porcine reproductive and respiratory syndrome virus leader protease Nsp1alpha.

    PubMed

    Sun, Yuna; Xue, Fei; Guo, Yu; Ma, Ming; Hao, Ning; Zhang, Xuejun C; Lou, Zhiyong; Li, Xuemei; Rao, Zihe

    2009-11-01

    Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV), a positive-strand RNA virus that belongs to the Arteriviridae family of Nidovirales, has been identified as the causative agent of PRRS. Nsp1alpha is the amino (N)-terminal protein in a polyprotein encoded by the PRRSV genome and is reported to be crucial for subgenomic mRNA synthesis, presumably by serving as a transcription factor. Before functioning in transcription, nsp1alpha proteolytically releases itself from nsp1beta. However, the structural basis for the self-releasing and biological functions of nsp1alpha remains elusive. Here we report the crystal structure of nsp1alpha of PRRSV (strain XH-GD) in its naturally self-processed form. Nsp1alpha contains a ZF domain (which may be required for its biological function), a papain-like cysteine protease (PCP) domain with a zinc ion unexpectedly bound at the active site (which is essential for proteolytic self-release of nsp1alpha), and a carboxyl-terminal extension (which occupies the substrate binding site of the PCP domain). Furthermore, we determined the exact location of the nsp1alpha self-processing site at Cys-Ala-Met180 downward arrowAla-Asp-Val by use of crystallographic data and N-terminal amino acid sequencing. The crystal structure also suggested an in cis self-processing mechanism for nsp1alpha. Furthermore, nsp1alpha appears to have a dimeric architecture both in solution and as a crystal, with a hydrophilic groove on the molecular surface that may be related to nsp1alpha's biological function. Compared with existing structure and function data, our results suggest that PRRSV nsp1alpha functions differently from other reported viral leader proteases, such as that of foot-and-mouth disease. PMID:19706710

  12. Prostaglandin E receptor 4 (EP4) promotes colonic tumorigenesis.

    PubMed

    Chang, Jian; Vacher, Jean; Yao, Bing; Fan, Xiaofeng; Zhang, Bixiang; Harris, Raymond C; Zhang, Ming-Zhi

    2015-10-20

    Colorectal cancer (CRC) continues to be a major cause of morbidity and mortality. Although the factors underlying CRC development and progression are multifactorial, there is an important role for tumor-host interactions, especially interactions with myeloid cells. There is also increasing evidence that cyclooxygenase-derived prostaglandins are important mediators of CRC development and growth. Although prevention trials with either nonselective NSAIDs or COX-2 selective agents have shown promise, the gastrointestinal or cardiovascular side effects of these agents have limited their implementation. The predominant prostaglandin involved in CRC pathogenesis is PGE2. Since myeloid cells express high levels of the PGE2 receptor subtype, EP4, we selectively ablated EP4 in myeloid cells and studied adenoma formation in a mouse model of intestinal adenomatous polyposis, ApcMin/+ mice. ApcMin/+mice with selective myeloid cell deletion of EP4 had marked inhibition of both adenoma number and size, with associated decreases in mTOR and ERK activation. Either genetic or pharmacologic inhibition of EP4 receptors led to an anti-tumorigenic M1 phenotype of macrophages/dendritic cells. Therefore, PGE2-mediated EP4 signaling in myeloid cells promotes tumorigenesis, suggesting EP4 as a potentially attractive target for CRC chemoprevention or treatment. PMID:26378024

  13. Prostaglandin E receptor 4 (EP4) promotes colonic tumorigenesis

    PubMed Central

    Chang, Jian; Vacher, Jean; Yao, Bing; Fan, Xiaofeng; Zhang, Bixiang; Harris, Raymond C.; Zhang, Ming-Zhi

    2015-01-01

    Colorectal cancer (CRC) continues to be a major cause of morbidity and mortality. Although the factors underlying CRC development and progression are multifactorial, there is an important role for tumor-host interactions, especially interactions with myeloid cells. There is also increasing evidence that cyclooxygenase-derived prostaglandins are important mediators of CRC development and growth. Although prevention trials with either nonselective NSAIDs or COX-2 selective agents have shown promise, the gastrointestinal or cardiovascular side effects of these agents have limited their implementation. The predominant prostaglandin involved in CRC pathogenesis is PGE2. Since myeloid cells express high levels of the PGE2 receptor subtype, EP4, we selectively ablated EP4 in myeloid cells and studied adenoma formation in a mouse model of intestinal adenomatous polyposis, ApcMin/+ zmice. ApcMin/+mice with selective myeloid cell deletion of EP4 had marked inhibition of both adenoma number and size, with associated decreases in mTOR and ERK activation. Either genetic or pharmacologic inhibition of EP4 receptors led to an anti-tumorigenic M1 phenotype of macrophages/dendritic cells. Therefore, PGE2-mediated EP4 signaling in myeloid cells promotes tumorigenesis, suggesting EP4 as a potentially attractive target for CRC chemoprevention or treatment. PMID:26378024

  14. Androgen regulation of thromboxane A2/prostaglandin H2 receptor expression in human erythroleukemia cells.

    PubMed

    Matsuda, K; Mathur, R S; Duzic, E; Halushka, P V

    1993-12-01

    Thromboxane A2 (TxA2), a platelet aggregator and vasoconstrictor, has been implicated as a potential mediator of cardiovascular diseases. Abuse of androgenic steroids has been associated with thrombotic cardiovascular diseases. Human erythroleukemia (HEL) cells, a megakaryocyte-like cell line, express functional TxA2/prostaglandin H2 (PGH2) receptors with characteristics similar to those seen in platelets. This study characterized testosterone regulation of HEL cell TxA2/PGH2 receptors. TxA2/PGH2 receptor affinity (Kd) and density (Bmax) were determined via equilibrium binding experiments using the radiolabeled TxA2 mimetic (1S-[1 alpha,2 beta(5Z),3 alpha(1E,3R*),4 alpha])-7-(3-[3-hydroxy-4-(4'- iodophenoxy)-1-butenyl]-7-oxabicyclo[2.2.1]heptan-2-yl)-5-he ptenoic acid (125I-labeled BOP). Testosterone (200 nM) but not estradiol increased Bmax from 108 +/- 9 fmol/mg protein to 157 +/- 9 fmol/mg protein (n = 7 experiments; P < 0.01) without any significant change in Kd. Testosterone had no significant effect on alpha 2-adrenergic receptor density. The maximum increase in intracellular free calcium induced by the TxA2 agonists I-BOP or U-46619 was significantly (P < 0.005) greater in testosterone-treated cells compared with controls. Hydroxyflutamide (1 microM), an androgen-receptor antagonist, completely blocked the effect of testosterone (P < 0.01). Dihydrotestosterone, the active metabolite of testosterone, also increased Bmax in a concentration-dependent manner and was more potent than testosterone. The effect of testosterone to increase Bmax was significantly (P < 0.01) inhibited by coincubation with cycloheximide (0.1 microgram/ml) or actinomycin D (10 ng/ml). These results indicate that androgenic steroids regulate the expression of functional TxA2/PGH2 receptors in HEL cells. These findings may have relevance to cardiovascular disease. PMID:8279549

  15. Development of Potent and Selective Indomethacin Analogues for the Inhibition of AKR1C3 (Type 5 17β-Hydroxysteroid Dehydrogenase/Prostaglandin F Synthase) in Castrate-Resistant Prostate Cancer

    PubMed Central

    2013-01-01

    Castrate-resistant prostate cancer (CRPC) is a fatal, metastatic form of prostate cancer. CRPC is characterized by reactivation of the androgen axis due to changes in androgen receptor signaling and/or adaptive intratumoral androgen biosynthesis. AKR1C3 is upregulated in CRPC where it catalyzes the formation of potent androgens. This makes AKR1C3 a target for the treatment of CRPC. AKR1C3 inhibitors should not inhibit AKR1C1/AKR1C2, which inactivate 5α-dihydrotestosterone. Indomethacin, used to inhibit cyclooxygenase, also inhibits AKR1C3 and displays selectivity over AKR1C1/AKR1C2. Parallel synthetic strategies were used to generate libraries of indomethacin analogues, which exhibit reduced cyclooxygenase inhibitory activity but retain AKR1C3 inhibitory potency and selectivity. The lead compounds inhibited AKR1C3 with nanomolar potency, displayed >100-fold selectivity over AKR1C1/AKR1C2, and blocked testosterone formation in LNCaP-AKR1C3 cells. The AKR1C3·NADP+·2′-des-methyl-indomethacin crystal structure was determined, and it revealed a unique inhibitor binding mode. The compounds reported are promising agents for the development of therapeutics for CRPC. PMID:23432095

  16. Development of potent and selective indomethacin analogues for the inhibition of AKR1C3 (Type 5 17β-hydroxysteroid dehydrogenase/prostaglandin F synthase) in castrate-resistant prostate cancer.

    PubMed

    Liedtke, Andy J; Adeniji, Adegoke O; Chen, Mo; Byrns, Michael C; Jin, Yi; Christianson, David W; Marnett, Lawrence J; Penning, Trevor M

    2013-03-28

    Castrate-resistant prostate cancer (CRPC) is a fatal, metastatic form of prostate cancer. CRPC is characterized by reactivation of the androgen axis due to changes in androgen receptor signaling and/or adaptive intratumoral androgen biosynthesis. AKR1C3 is upregulated in CRPC where it catalyzes the formation of potent androgens. This makes AKR1C3 a target for the treatment of CRPC. AKR1C3 inhibitors should not inhibit AKR1C1/AKR1C2, which inactivate 5α-dihydrotestosterone. Indomethacin, used to inhibit cyclooxygenase, also inhibits AKR1C3 and displays selectivity over AKR1C1/AKR1C2. Parallel synthetic strategies were used to generate libraries of indomethacin analogues, which exhibit reduced cyclooxygenase inhibitory activity but retain AKR1C3 inhibitory potency and selectivity. The lead compounds inhibited AKR1C3 with nanomolar potency, displayed >100-fold selectivity over AKR1C1/AKR1C2, and blocked testosterone formation in LNCaP-AKR1C3 cells. The AKR1C3·NADP(+)·2'-des-methyl-indomethacin crystal structure was determined, and it revealed a unique inhibitor binding mode. The compounds reported are promising agents for the development of therapeutics for CRPC. PMID:23432095

  17. Castration Therapy of Prostate Cancer Results in Downregulation of HIF-1{alpha} Levels

    SciTech Connect

    Al-Ubaidi, Firas L.T.; Schultz, Niklas; Egevad, Lars; Granfors, Torvald; Helleday, Thomas

    2012-03-01

    Background and Purpose: Neoadjuvant androgen deprivation in combination with radiotherapy of prostate cancer is used to improve radioresponsiveness and local tumor control. Currently, the underlying mechanism is not well understood. Because hypoxia causes resistance to radiotherapy, we wanted to test whether castration affects the degree of hypoxia in prostate cancer. Methods and Materials: In 14 patients with locally advanced prostate cancer, six to 12 prostatic needle core biopsy specimens were taken prior to castration therapy. Bilateral orchidectomy was performed in 7 patients, and 7 were treated with a GnRH-agonist (leuprorelin). After castrationm two to four prostatic core biopsy specimens were taken, and the level of hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) in cancer was determined by immunofluorescence. Results: Among biopsy specimens taken before castration, strong HIF-1{alpha} expression (mean intensity above 30) was shown in 5 patients, weak expression (mean intensity 10-30) in 3 patients, and background levels of HIF-1{alpha} (mean intensity 0-10) in 6 patients. Downregulation of HIF-1{alpha} expression after castration was observed in all 5 patients with strong HIF-1{alpha} precastration expression. HIF-1{alpha} expression was also reduced in 2 of 3 patients with weak HIF-1{alpha} precastration expression. Conclusions: Our data suggest that neoadjuvant castration decreases tumor cell hypoxia in prostate cancer, which may explain increased radiosensitivity after castration.

  18. Identification and characterization of an alternative promoter of the human PGC-1{alpha} gene

    SciTech Connect

    Yoshioka, Toyo; Inagaki, Kenjiro; Noguchi, Tetsuya; Sakai, Mashito; Ogawa, Wataru; Hosooka, Tetsuya; Iguchi, Haruhisa; Watanabe, Eijiro; Matsuki, Yasushi; Hiramatsu, Ryuji; Kasuga, Masato

    2009-04-17

    The transcriptional regulator peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) controls mitochondrial biogenesis and energy homeostasis. Although physical exercise induces PGC-1{alpha} expression in muscle, the underlying mechanism of this effect has remained incompletely understood. We recently identified a novel muscle-enriched isoform of PGC-1{alpha} transcript (designated PGC-1{alpha}-b) that is derived from a previously unidentified first exon. We have now cloned and characterized the human PGC-1{alpha}-b promoter. The muscle-specific transcription factors MyoD and MRF4 transactivated this promoter through interaction with a proximal E-box motif. Furthermore, either forced expression of Ca{sup 2+}- and calmodulin-dependent protein kinase IV (CaMKIV), calcineurin A, or the p38 mitogen-activated protein kinase (p38 MAPK) kinase MKK6 or the intracellular accumulation of cAMP activated the PGC-1{alpha}-b promoter in cultured myoblasts through recruitment of cAMP response element (CRE)-binding protein (CREB) to a putative CRE located downstream of the E-box. Our results thus reveal a potential molecular basis for isoform-specific regulation of PGC-1{alpha} expression in contracting muscle.

  19. Interaction between HP1{alpha} and replication proteins in mammalian cells

    SciTech Connect

    Auth, Tanja . E-mail: tauth@uni-bonn.de; Kunkel, Elisabeth; Grummt, Friedrich . E-mail: grummt@biozentrum.uni-wuerzburg.de

    2006-10-15

    HP1 is an essential heterochromatin-associated protein known to play an important role in the organization of heterochromatin as well as in the transcriptional regulation of heterochromatic and euchromatic genes both in repression and activation. Using the yeast two-hybrid system and immunoprecipitation, we report here that murine HP1{alpha} interacts with the preRC proteins ORC1, ORC2 and CDC6. Immunofluorescence staining and EGFP/DsRed fusion proteins revealed a colocalization of HP1{alpha} with ORC1, ORC2 and CDC6 in heterochromatin, supporting the notion that ORC and probably CDC6 play an important role in murine HP1{alpha} function. Besides that, we also observed a colocalization of HP1{alpha} with {gamma}-tubulin suggesting a centrosomal localization of HP1{alpha} in murine cells. To gain insight into HP1{alpha} function, we applied the RNAi technique. Depletion of HP1{alpha} leads to a slow down of cell proliferation, an aberrant cell cycle progression as well as to multinucleated cells with insufficiently organized microtubule. These results together indicate that HP1{alpha} exerts functions in mitosis and cytokinesis.

  20. Molecular cloning and phylogenetic analysis of Clonorchis sinensis elongation factor-1alpha.

    PubMed

    Kim, Tae Yun; Cho, Pyo Yun; Na, Jong Won; Hong, Sung-Jong

    2007-11-01

    Elongation factor-1 (EF-1) plays a primary role in protein synthesis, e.g., in the regulation of cell growth, aging, motility, embryogenesis, and signal transduction. The authors identified a clone CsIH23 by immunoscreening a Clonorchis sinensis cDNA library. The cDNA of CsIH23 was found to have a putative open reading frame containing 461 amino acids with a predicted molecular mass of 50.5 kDa. Its polypeptide sequence was highly homologous with EF-1alpha of parasites and vertebrate animals. CsIH23 polypeptide contained three GTP/GDP-binding sites, one ribosome-binding domain, one actin-binding domain, one tRNA-binding domain, and two glyceryl-phosphoryl-ethanolamine attachment sites. Based on these primary and secondary structural similarities, it was concluded that CsIH23 cDNA encodes C. sinensis EF-1alpha (CsEF-1alpha). In a molecular phylogenic tree, CsEF-1alpha clustered with the EF-1alpha of helminthic parasites. Subsequently, CsEF-1alpha recombinant protein was bacterially overexpressed and purified by Ni-NTA affinity column chromatography. Immunoblotting using CsEF-1alpha recombinant protein produced positive signals for all serum samples tested from clonorchiasis, opisthorchiasis viverinii, and paragonimiasis westermani patients and normal healthy controls. These findings suggest that recombinant CsEF-1alpha is of limited usefulness as serodiagnostic antigen for clonorchiasis. PMID:17674047

  1. Effects of prostaglandins and prostaglandin synthetase inhibitors on acutely obstructed kidneys in the dog.

    PubMed

    Zwergel, U; Zwergel, T; Ziegler, M

    1991-01-01

    An intact canine model was developed to study the effects of prostaglandins (PG) and prostaglandin synthetase inhibitors on acutely obstructed kidneys. Totally implanted nephrostomy tubes were placed to measure renal pelvic pressure. Complete ureteral obstruction was obtained with a Fogarty balloon catheter inflated in the distal ureter; by this method renal pelvic pressure reached 40-50 mm Hg. Renal pelvic pressure was reduced after intravenous indomethacin and dipyrone administration, whereas blood pressure showed no major changes. Exogenous prostaglandins had both immediate and contrary effects: PGE2 caused a significant decrease, whereas PGF2 alpha caused a significant increase in renal pelvic and blood pressure. The reduced rise in renal pelvic pressure appears to be the main reason for the analgesic effects of prostaglandin synthetase inhibitors. The efficiency of these drugs in the treatment of renal colic is supported by this study, that of prostaglandins cannot be proved. PMID:1792708

  2. Hypoxia-inducible factor-1alpha: A promising therapeutic target in endometriosis.

    PubMed

    Zhan, Lei; Wang, Wenyan; Zhang, Yu; Song, Enxue; Fan, Yijun; Wei, Bing

    2016-04-01

    Endometriosis is a common gynecologic disease defined as the presence of ectopic endometrial tissues on the ovaries and pelvic peritoneum, and it is a significant cause of pelvic pain, dysmenorrhea and infertility of women in their reproductive age. However, the etiology of endometriosis remains obscure. In recent years, a growing body of evidence validated that hypoxia developed a close relationship with endometriosis and the expression of hypoxia-inducible factor-1alpha (HIF-1α) was increased significantly in the development of endometriosis. Furthermore, inhibiting the expression of HIF-1α contributed to suppress endometriosis progression, suggesting HIF-1α plays a critical function in endometriosis. Nevertheless, the mechanisms by which HIF-1α associates with endometriosis are still undefined. In this brief review, we had a general understanding of HIF-1α firstly, and then we tried to sum up the collective knowledge of HIF-1α in endometriosis. Finally, we will discuss kinds of novel therapeutic approaches to endometriosis based on the functions of HIF-1α. PMID:26898675

  3. Abnormal parathyroid hormone stimulation of 25-hydroxyvitamin D-1 alpha-hydroxylase activity in the hypophosphatemic mouse. Evidence for a generalized defect of vitamin D metabolism.

    PubMed Central

    Nesbitt, T; Drezner, M K; Lobaugh, B

    1986-01-01

    Abnormal regulation of vitamin D metabolism is a feature of X-linked hypophosphatemic rickets in man and of the murine homologue of the disease in the hypophosphatemic (Hyp)-mouse. We previously reported that mutant mice have abnormally low renal 25-hydroxyvitamin D-1 alpha-hydroxylase (1 alpha-hydroxylase) activity for the prevailing degree of hypophosphatemia. To further characterize this defect, we examined whether Hyp-mouse renal 1 alpha-hydroxylase activity responds normally to other stimulatory and inhibitory controls of enzyme function. We studied stimulation by parathyroid hormone (PTH) using: (a) a calcium-deficient (0.02% Ca) diet to raise endogenous PTH; or (b) 24-h continuous infusion of 0.25 IU/h bovine PTH via osmotic minipump. In both cases enzyme activity of identically treated normal mice increased to greater levels than those attained by Hyp-mice. The relative inability of PTH to stimulate 1 alpha-hydroxylase activity is not a function of the hypophosphatemia in the Hyp-mouse since PTH-infused, phosphate-depleted normal mice sustained a level of enzyme activity greater than that of normal and Hyp-mice. In further studies we investigated inhibition of enzyme activity by using: (a) a calcium-loaded (1.2% Ca) diet to suppress endogenous PTH; or (b) 24-h continuous infusion of 0.2 ng/h 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). The 1 alpha-hydroxylase activity of normal and Hyp-mice was significantly reduced to similar absolute levels following maintenance on the calcium-loaded diet. Further, infusion of 1,25(OH)2D3 caused a comparable reduction of 1 alpha-hydroxylase activity in normal, Hyp-, and phosphate-depleted normal mice. These observations indicate that the inhibitory control of 1 alpha-hydroxylase by reduced levels of PTH or increased 1,25(OH)2D3 concentrations is intact in the mutants. However, the inability of PTH and hypophosphatemia to stimulate enzyme activity in a manner analogous to that in normal and phosphate-depleted mice indicates

  4. Prostaglandin potentiates 5-HT responses in stomach and ileum innervating visceral afferent sensory neurons.

    PubMed

    Kim, Sojin; Jin, Zhenhua; Lee, Goeun; Park, Yong Seek; Park, Cheung-Seog; Jin, Young-Ho

    2015-01-01

    Gastrointestinal disorder is a common symptom induced by diverse pathophysiological conditions that include food tolerance, chemotherapy, and irradiation for therapy. Prostaglandin E2 (PGE2) level increase was often reported during gastrointestinal disorder and prostaglandin synthetase inhibitors has been used for ameliorate the symptoms. Exogenous administration of PGE2 induces gastrointestinal disorder, however, the mechanism of action is not known. Therefore, we tested PGE2 effect on visceral afferent sensory neurons of the rat. Interestingly, PGE2 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 PGE2-induced potentiation were blocked by a selective E-prostanoid type 4 (EP4) receptors antagonist, L-161,982, but type 1 and 2 receptor antagonist AH6809 has no effect. A membrane permeable protein kinase A (PKA) inhibitor, KT5720 also inhibited PGE2 effects. PGE2 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 PGE2 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 prostaglandin synthetase inhibitors by selectively targeting EP4 receptor/PKA pathway without interrupt prostaglandin synthesis. PMID:25446121

  5. Wortmannin influences hypoxia-inducible factor-1 alpha expression and glycolysis in esophageal carcinoma cells

    PubMed Central

    Zeng, Ling; Zhou, Hai-Yun; Tang, Na-Na; Zhang, Wei-Feng; He, Gui-Jun; Hao, Bo; Feng, Ya-Dong; Zhu, Hong

    2016-01-01

    AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B (PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia. METHODS: Esophageal carcinoma cell lines Eca109 and TE13 were cultured under hypoxia environment, and the protein, mRNA and activity levels of hypoxia inducible factor-1 alpha (HIF-1α), glucose transporter 1, hexokinase-II, phosphofructokinase 2 and lactate dehydrogenase-A were determined. Supernatant lactic acid concentrations were also detected. The PI3K/AKT signaling pathway was then inhibited with wortmannin, and the effects of hypoxia on the expression or activities of HIF-1α, associated glycolytic enzymes and lactic acid concentrations were observed. Esophageal carcinoma cells were then transfected with interference plasmid with HIF-1α-targeting siRNA to assess impact of the high expression of HIF-1α on glycolysis. RESULTS: HIF-1α is highly expressed in the esophageal carcinoma cell lines tested, and with decreasing levels of oxygen, the expression of HIF-1α and the associated glycolytic enzymes and the extracellular lactic acid concentration were enhanced in the esophageal carcinoma cell lines Eca109 and TE13. In both normoxia and hypoxic conditions, the level of glycolytic enzymes and the secretion of lactic acid were both reduced by wortmannin. The expression and activities of glycolytic enzymes and the lactic acid concentration in cells were reduced by inhibiting HIF-1α, especially the decreasing level of glycolysis was significant under hypoxic conditions. CONCLUSION: The PI3K/AKT pathway and HIF-1α are both involved in the process of glycolysis in esophageal cancer cells. PMID:27239113

  6. Milk fever controls: comparison of 1-alpha and vitamin D3 in conjunction with induced parturition.

    PubMed

    McMurray, C H; Rice, D A; McBride, P S

    1980-08-30

    The efficacies of vitamin D3 and its 1-alpha hydroxyl derivative (1-alpha) in controlling clinical milk fever, hypocalcaemia and hypophosphataemia in parturient cows have been compared. A corticosteroid was used in some cases to optimise and control the interval between prophylactic treatment and parturition. Our observations suggest that the combination of 1-alpha and corticosteroid was particularly valuable and could be used in the development of a successful prophylactic regime. This conclusion is supported by both clinical and biochemical measurements. PMID:6255674

  7. Prostaglandins are important in thermoregulation of a reptile (Pogona vitticeps).

    PubMed Central

    Seebacher, Frank; Franklin, Craig E

    2003-01-01

    The effectiveness of behavioural thermoregulation in reptiles is amplified by cardiovascular responses, particularly by differential rates of heart beat in response to heating and cooling (heart-rate hysteresis). Heart-rate hysteresis is ecologically important in most lineages of ectothermic reptile, and we demonstrate that heart-rate hysteresis in the lizard Pogona vitticeps is mediated by prostaglandins. In a control treatment (administration of saline), heart rates during heating were significantly faster than during cooling at any given body temperature. When cyclooxygenase 1 and 2 enzymes were inhibited, heart rates during heating were not significantly different from those during cooling. Administration of agonists showed that thromboxane B(2) did not have a significant effect on heart rate, but prostacyclin and prostaglandin F(2alpha) caused a significant increase (3.5 and 13.6 beats min(-1), respectively) in heart rate compared with control treatments. We speculate that heart-rate hysteresis evolved as a thermoregulatory mechanism that may ultimately be controlled by neurally induced stimulation of nitric oxide production, or maybe via photolytically induced production of vitamin D. PMID:12952634

  8. Canine gastric mucosal vasodilation with prostaglandins and histamine analogs

    SciTech Connect

    Gerber, J.G.; Nies, A.S.

    1982-10-01

    The effect of direct intragastric artery infusion of prostaglandins E2 and I2, arachidonic acid, dimaprit (histamine H2 agonist), and 2',2'-pyridylethylamine (histamine H1 agonist) on gastric mucosal blood flow was examined in dogs to elucidate the relationship between gastric secretory state and mucosal blood flow in dogs. These compounds were chosen because of their diverse effect on gastric acid secretion. Gastric fundus blood flow was measured both electromagnetically with a flow probe around the left gastric artery which supplies the fundus almost exclusively, and by the radioactive microsphere technique. Intraarterial infusion of all the compounds resulted in gastric mucosal vasodilation even though PGE2, PGI2, and arachidonic acid inhibit gastric acid secretion, dimaprit stimulated gastric acid secretion, and 2',2'-pyridylethylamine does not affect gastric acid secretion. There was total agreement in the blood flow measurements by the two different techniques. Our data suggest that gastric acid secretion and gastric vasodilation are independently regulated. In addition, the validity of the studies in which the aminopyrine clearance indicates that prostaglandins are mucosal vasoconstrictors needs to be questioned because of the reliance of those measurements on the secretory state of the stomach.

  9. Effect of ozone exposure on lung functions and plasma prostaglandin and thromboxane concentrations in guinea pigs

    SciTech Connect

    Miller, P.D.; Ainsworth, D.; Lam, H.F.; Amdur, M.O.

    1987-03-30

    Male Hartley guinea pigs were exposed either to filtered air or to 1 ppm ozone (O/sub 3/) for 1 hr. At 2, 8, 24, or 48 hr after exposure we measured ventilation, respiratory mechanics, lung volumes, diffusing capacity for carbon monoxide (DLCO), and alveolar volume (VA) in anesthetized, tracheotomized animals. Respiratory frequency and tidal volume were unchanged in all groups. Pulmonary resistance was increased 2 hr after O/sub 3/ but returned to control at 8 hr and thereafter. Prolonged reductions in lung volumes (total lung capacity, vital capacity, functional residual capacity, and residual volume) as well as in DLCO and VA occurred after O/sub 3/, with maximum decreases at 8 and 24 hr postexposure. Increased ratios of wet lung weight to body weight were seen at 2, 8, and 24 hr. In separate groups of animals, also exposed either to filtered air or to 1 ppm O/sub 3/, plasma eicosanoid (EC) concentrations were measured at 2, 8, 24, 48, or 72 hr after exposure. Significant increases in thromboxane B2 concentrations were seen at 2, 24, and 48 hr after exposure. Plasma concentrations of 6-keto prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E1 (PGE1) were increased at 24 hr and at 24, 48, and 72 hr, respectively. The nature of this long-term pulmonary response to a short-term exposure to O/sub 3/ suggests alveolar involvement, including probable alveolar duct constriction and localized pulmonary edema. Although changes in plasma EC concentrations were observed concurrent with impaired lung functions, no simple causal relationship was apparent from these studies.

  10. Elongation factor 1 alpha concentration is highly correlated with the lysine content of maize endosperm.

    PubMed Central

    Habben, J E; Moro, G L; Hunter, B G; Hamaker, B R; Larkins, B A

    1995-01-01

    Lysine is the most limiting essential amino acid in cereals, and for many years plant breeders have attempted to increase its concentration to improve the nutritional quality of these grains. The opaque2 mutation in maize doubles the lysine content in the endosperm, but the mechanism by which this occurs is unknown. We show that elongation factor 1 alpha (EF-1 alpha) is overexpressed in opaque2 endosperm compared with its normal counterpart and that there is a highly significant correlation between EF-1 alpha concentration and the total lysine content of the endosperm. This relationship is also true for two other cereals, sorghum and barley. It appears that genetic selection for genotypes with a high concentration of EF-1 alpha can significantly improve the nutritional quality of maize and other cereals. Images Fig. 1 Fig. 2 PMID:7567989

  11. Cell cycle arrest by prostaglandin A1 at the G1/S phase interface with up-regulation of oncogenes in S-49 cyc- cells

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.

    1994-01-01

    Our previous studies have implied that prostaglandins inhibit cell growth independent of cAMP. Recent reports, however, have suggested that prostaglandin arrest of the cell cycle may be mediated through protein kinase A. In this report, in order to eliminate the role of c-AMP in prostaglandin mediated cell cycle arrest, we use the -49 lymphoma variant (cyc-) cells that lack adenylate cyclase activity. We demonstrate that dimethyl prostaglandin A1 (dmPGA1) inhibits DNA synthesis and cell growth in cyc- cells. DNA synthesis is inhibited 42% by dmPGA1 (50 microM) despite the fact that this cell line lacks cellular components needed for cAMP generation. The ability to decrease DNA synthesis depends upon the specific prostaglandin structure with the most effective form possessing the alpha, beta unsaturated ketone ring. Dimethyl PGA1 is most effective in inhibiting DNA synthesis in cyc- cells, with prostaglandins PGE1 and PGB1 being less potent inhibitors of DNA synthesis. DmPGE2 caused a significant stimulation of DNA synthesis. S-49 cyc- variant cells exposed to (30-50 microns) dmPGA1, arrested in the G1 phase of the cell cycle within 24 h. This growth arrest was reversed when the prostaglandin was removed from the cultured cells; growth resumed within hours showing that this treatment is not toxic. The S-49 cyc- cells were chosen not only for their lack of adenylate cyclase activity, but also because their cell cycle has been extensively studied and time requirements for G1, S, G2, and M phases are known. Within hours after prostaglandin removal the cells resume active DNA synthesis, and cell number doubles within 15 h suggesting rapid entry into S-phase DNA synthesis from the G1 cell cycle block.(ABSTRACT TRUNCATED AT 250 WORDS).

  12. Expression of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1alpha (HIF-1alpha), and microvessel density in endometrial tissue in women with adenomyosis.

    PubMed

    Goteri, Gaia; Lucarini, Guendalina; Montik, Nina; Zizzi, Antonio; Stramazzotti, Daniela; Fabris, Guidalberto; Tranquilli, Andrea Luigi; Ciavattini, Andrea

    2009-03-01

    Adenomyosis is a disease with a mysterious pathogenesis, defined by an abnormal displacement of the eutopic endometrium deeply and haphazardly inside the myometrium. Angiogenesis has been indicated to play an important role and our aim was to investigate whether vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1alpha (HIF-1alpha) expression and microvessel density (MVD) were different in women with and without adenomyosis. Immunohistochemistry was performed in endometrial tissues in 23 patients who underwent radical hysterectomy for adenomyosis (14) and for ovarian cysts and fibroids (9) at an Academic Hospital. Compared to women without the disease, VEGF expression was increased in endometrium with a normal location in patients with adenomyosis, although not associated to a significant increase of HIF-1alpha and MVD. Moreover, the endometrium with an abnormal location in patients with adenomyosis showed an increased VEGF and HIF-1alpha expression, particularly in the epithelial cells, associated to an increase of MVD, compared with the endometrium in a normal location in the same group of patients. Our present findings suggest that VEGF-mediated angiogenesis might be associated with the development of adenomyosis. In the ectopic foci the abnormal location might contribute to increased HIF-1a expression, stimulation of VEGF production, and increased vessel formation. In endometrium with a normal location, instead, where VEGF increased expression seems not to be correlated with HIF-1alpha increased expression nor with an increased MVD, other mechanisms might be reasonably postulated. Additional studies are required to explore new targeted and more effective treatment modalities. PMID:19188818

  13. Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

    PubMed

    Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

    2002-08-15

    The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination. PMID:12181572

  14. Reduced serum levels of 1 alpha,25-dihydroxyvitamin D during long-term total parenteral nutrition.

    PubMed

    Klein, G L; Horst, R L; Norman, A W; Ament, M E; Slatopolsky, E; Coburn, J W

    1981-05-01

    Painful bone disease, characterized by patchy osteomalacia and inactive bone, can develop in patients treated with total parenteral nutrition for more than 3 months. Serum levels of 1 alpha,25-dihydroxyvitamin D (1 alpha, 25(OH)2D), 24,25-dihydroxyvitamin D and 25-hydroxyvitamin D were measured in seven adults and five children treated with parenteral nutrition for 9 to 60 months. Serum levels of 1 alpha, 25(OH)2D were markedly reduced, while levels of 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D were normal. Serum calcium and phosphorus levels were normal or slightly increased, and immunoreactive parathyroid hormone levels were normal or low. Renal function was normal or minimally reduced. Skeletal symptoms disappeared and serum 1 alpha, 25(OH)2D levels rose to normal in one patient when nutrient infusions were discontinued for 6 weeks. Removal of calcium from the nutrient solution for 2 to 4 days was associated with no change in serum 1 alpha, 25(OH)2D in two patients. The cause of the reduction in serum levels of 1 alpha, 25(OH)2D and its role in the pathogenesis of bone disease in these patients remain uncertain. PMID:6786151

  15. Staurosporine, but not Ro 31-8220, induces interleukin 2 production and synergizes with interleukin 1alpha in EL4 thymoma cells.

    PubMed Central

    Mahon, T M; Matthews, J S; O'Neill, L A

    1997-01-01

    Protein kinase C (PKC) has been implicated in interleukin 1 (IL1) signal transduction in a number of cellular systems, either as a key event in IL1 action or as a negative regulator. Here we have examined the effects of two PKC inhibitors, staurosporine and the more selective agent Ro 31-8220, on IL1 responses in the murine thymoma line EL4.NOB-1. A 1 h pulse of staurosporine was found to strongly potentiate the induction of IL2 by IL1alpha in these cells. In contrast, neither a pulse nor prolonged incubation with Ro 31-8220 affected the response to IL1alpha. Both agents blocked the response to PMA, however. A 1 h pulse of staurosporine was also found to induce IL2 production on its own, activate the transcription factor nuclear factor kappaB (NFkappaB) and increase the expression of a NFkappaB-linked reporter gene. It synergized with IL1alpha in all of these responses. Ro 31-8220 was again without effect, although both staurosporine and Ro 31-8220 blocked the activation of NFkappaB by PMA. Finally, staurosporine caused the translocation of PKC-alpha and -epsilon, and to a lesser extent PKC-beta, but not PKC-θ or -zeta, from the cytosol to the membrane, although a similar effect was observed with Ro 31-8220. The results suggest that PKC is not involved in IL1alpha signalling in EL4 cells. Furthermore, the potentiating effect of staurosporine on IL1alpha action does not involve PKC inhibition, and is likely to be at the level of NFkappaB activation. PMID:9224627

  16. The Inflammasome and the Epidermal Growth Factor Receptor (EGFR) Are Involved in the Staphylococcus aureus-Mediated Induction of IL-1alpha and IL-1beta in Human Keratinocytes

    PubMed Central

    Schröder, Lena; Gläser, Regine; Harder, Jürgen

    2016-01-01

    Staphylococcus (S.) aureus is an important pathogen causing various infections including those of the skin. Keratinocytes are able to sense invading S. aureus and to initiate a fast defense reaction by the rapid release of innate defense mediators such as antimicrobial peptides and cytokines. There is increasing evidence that the cytokines IL-1alpha and IL-1beta, which both signal through the IL-1 receptor, play an important role in cutaneous defense against S. aureus. The aim of this study was to gain more insight into the underlying mechanisms leading to the S. aureus-induced IL-1alpha and IL-1beta expression in keratinocytes. Infection of human primary keratinocytes with S. aureus led to the induction of gene expression and protein secretion of IL-1alpha and IL-1beta. Full S. aureus-induced IL-1 protein release required the inflammasome components caspase-1 and ASC (apoptosis-associated speck-like protein containing a CARD) whereas gene induction of IL-1alpha and IL-beta by S. aureus was not dependent on caspase-1 and ASC. Since patients receiving anti-cancer therapy by inhibition of the epidermal growth factor receptor (EGFR) often suffer from skin infections caused by S. aureus we additionally evaluated whether the EGFR pathway may be involved in the IL-1alpha and IL-1beta induction by S. aureus. Inactivation of the EGFR with a blocking antibody decreased the S. aureus-mediated IL-1alpha and IL-1beta induction in primary keratinocytes. Moreover, the use of siRNA experiments revealed that ADAM17 (A Disintegrin and A Metalloprotease 17), a metalloproteinase known to mediate the shedding and release of EGFR ligands, was required for full induction of IL-1alpha and IL-1beta in keratinocytes infected with S. aureus. A failure of keratinocytes to adequately upregulate IL-1alpha and IL-1beta may promote S. aureus skin infections. PMID:26808616

  17. Prostaglandins and their receptors in insect biology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We treat the biological significance of prostaglandins (PGs) and their known receptors in insect biology. PGs and related eicosanoids are oxygenated derivatives of arachidonic acid (AA) and two other C20 polyunsaturated fatty acids. PGs are mostly appreciated in the context of biomedicine, but a gr...

  18. A DC-81-indole conjugate agent suppresses melanoma A375 cell migration partially via interrupting VEGF production and stromal cell-derived factor-1{alpha}-mediated signaling

    SciTech Connect

    Hsieh, Ming-Chu; Hu, Wan-Ping; Yu, Hsin-Su; Wu, Wen-Chuan; Chang, Long-Sen; Kao, Ying-Hsien; Wang, Jeh-Jeng

    2011-09-01

    Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) chemicals are antitumor antibiotics inhibiting nucleic acid synthesis. An indole carboxylate-PBD hybrid with six-carbon spacer structure (IN6CPBD) has been previously demonstrated to induce melanoma cell apoptosis and reduce metastasis in mouse lungs. This study aimed at investigating the efficacy of the other hybrid compound with four-carbon spacer (IN4CPBD) and elucidating its anti-metastatic mechanism. Human melanoma A375 cells with IN4CPBD treatment underwent cytotoxicity and apoptosis-associated assays. Transwell migration assay, Western blotting, and ELISA were used for mechanistic study. IN4CPBD exhibited potent melanoma cytotoxicity through interrupting G1/S cell cycle progression, increasing DNA fragmentation and hypodipoidic DNA contents, and reducing mitochondrial membrane potential. Caspase activity elevation suggested that both intrinsic and extrinsic pathways were involved in IN4CPBD-induced melanoma apoptosis. IN4CPBD up-regulated p53 and p21, thereby concomitantly derailing the equilibrium between Bcl-2 and Bax levels. Transwell migration assay demonstrated that stromal cell-derived factor-1{alpha} (SDF-1{alpha}) stimulated A375 cell motility, while kinase inhibitors treatment confirmed that Rho/ROCK, Akt, ERK1/2, and p38 MAPK pathways were involved in SDF-1{alpha}-enhanced melanoma migration. IN4CPBD not only abolished the SDF-1{alpha}-enhanced chemotactic motility but also suppressed constitutive MMP-9 and VEGF expression. Mechanistically, IN4CPBD down-regulated Akt, ERK1/2, and p38 MAPK total proteins and MYPT1 phosphorylation. In conclusion, beyond the fact that IN4CPBD induces melanoma cell apoptosis at cytotoxic dose, the interruption in the VEGF expression and the SDF-1{alpha}-related signaling at cytostatic dose may partially constitute the rationale for its in vivo anti-metastatic potency. - Research Highlights: > A novel carboxylate-PBD hybrid as anti-melanoma drug. > IN4CPBD interrupts melanoma cell

  19. Effects of methylxanthines on urinary prostaglandin E excretion in rats.

    PubMed

    Takeuchi, K; Kogo, H; Aizawa, Y

    1981-04-01

    Effect of methylxanthines (theophylline, theobromine and caffeine) on urinary prostaglandin E (PGE) excretion in male rats was studied. Oral administration of xanthines significantly increased the urinary excretion of PGE. Dose-response studies showed that the maximal excretion of urinary PGE and water was obtained by administration of theophylline (50 mg/kg), where the increase in PGE was about 20 times that of the control. The excretion of urinary sodium, potassium and chloride was also markedly increased by xanthines, particularly, theophylline. Increases in urinary PGE excretion, urine volume and electrolytes excretion were inhibited by 10 mg/kg of indomethacin administered prior to theophylline. The increase of urinary PGE excretion after theophylline administration (50 mg/kg) preceded increases in water and sodium excretion. These results suggest that renal PGE mediates, at least in part, the diuretic effect of theophylline. PMID:7311144

  20. Prostaglandin inhibitor and radiotherapy in advanced head and neck cancers

    SciTech Connect

    Pillsbury, H.C. III; Webster, W.P.; Rosenman, J.

    1986-05-01

    Radiotherapy is the usual mode of treatment for unresectable head and neck cancer. To improve cure rates, extend survival, and reduce morbidity, we use accelerated hyperfractionation radiotherapy and an adjuvant drug to inhibit prostaglandin synthesis. In this study, 19 patients received 300 rad/day of radiotherapy in two equally divided doses to a total dose averaging 6,200 rad. Either indomethacin, 25 mg, or placebo was given four times a day in a double-blind fashion during therapy. Radiation mucositis was graded as 0 to 4+; pain, nutritional status, and tumor status were monitored daily and recorded biweekly. Evaluation of the data showed delayed mucositis in the experimental group for grades 1 to 3, with a significant difference at grade 3 compared with controls. The significance of a long-term comparison of cure rates would be doubtful considering the heterogeneity of the primary sites and regional disease in this group coupled with the small size of our study.

  1. Prostaglandin ethanolamides attenuate damage in a human explant colitis model.

    PubMed

    Nicotra, Lauren L; Vu, Megan; Harvey, Benjamin S; Smid, Scott D

    2013-01-01

    Endocannabinoids are protective in animal colitis models. As endocannabinoids also form novel prostaglandin ethanolamides (prostamides) via COX-2, we investigated the effects of prostamides and other COX-2 mediators on tissue damage in an ex vivo human mucosal explant colitis model. Healthy human colonic mucosae were incubated with pro-inflammatory cytokines TNF-α and IL-1β to elicit colitis-like tissue damage. The PGF-ethanolamide analogue, bimatoprost decreased colitis scores which were reversed by a prostamide-specific antagonist AGN 211334, but not the FP receptor antagonist AL-8810. PGF-ethanolamide and PGE-ethanolamide also reduced cytokine-evoked epithelial damage. Anandamide was protective in the explant colitis model; however COX-2 inhibition did not alter its effects, associated with a lack of COX-2 induction in explant mucosal tissue. These findings support an anti-inflammatory role for prostamides and endocannabinoids in the human colon. PMID:23380599

  2. Effect of Diethylcarbamazine (DEC) on prostaglandin levels in Wuchereria bancrofti infected microfilaraemics.

    PubMed

    Sankari, T; Hoti, S L; Das, L K; Govindaraj, V; Das, P K

    2013-06-01

    Diethylcarbamazine (DEC) interferes with arachidonic acid metabolism for the clearance of microfilariae in Wuchereria bancrofti infected individuals. In this study, we have quantified the plasma concentrations of prostaglandin E2 (PGE2) and 6-keto-PGF1α, the end products of arachidonic acid metabolic pathway in microfilaraemics (DEC treated and untreated), and normal healthy individuals at pre- and 3,9,12,36, and 72 h of post-DEC treatment. We have also determined the microfilariae counts at pre and post day 2 (36 h) and day 3 (72 h) of DEC treatment by membrane filtration technique. Significant reduction in PGE2 and 6-keto-PGF1α concentrations was found at 12 h of DEC treatment. Rapid reduction in microfilarial counts was observed at 36 h of post-DEC treatment. Higher levels of prostaglandins were found at pre-treatment hours in microfilaraemics compared to normal healthy individuals (P < 0.05). Our findings indicate that DEC inhibits prostaglandins for the clearance of microfilariae, and increased levels of prostaglandins in microfilaraemics may be contributed by the parasite or host upon stimulation. PMID:23525692

  3. The prostaglandin E2 receptor EP4 is integral to a positive feedback loop for prostaglandin E2 production in human macrophages infected with Mycobacterium tuberculosis

    PubMed Central

    Nishimura, Tomoyasu; Zhao, Xiaomin; Gan, Huixian; Koyasu, Shigeo; Remold, Heinz G.

    2013-01-01

    Prostaglandin E2 (PGE2) is an important biological mediator involved in the defense against Mycobacterium tuberculosis (Mtb) infection. Previously, we reported that in macrophages (Mφs), infection with avirulent Mtb H37Ra resulted in inhibition of necrosis by an inhibitory effect on mitochondrial permeability transition via the PGE2 receptor EP2. However, human Mφs also express EP4, a PGE2 receptor functionally closely related to EP2 that also couples to stimulatory guanine nucleotide binding protein, but the functional differences between EP2 and EP4 in Mtb-infected Mφs have been unclear. EP4 antagonist addition to H37Ra-infected Mφs inhibited the expression of cyclooxygenase 2 (COX2) and microsomal prostaglandin E synthase-1 (mPGES-1), which are involved in PGE2 production. Moreover, H37Ra infection induced PGE2 production through the Toll-like receptor (TLR) 2/p38 mitogen-activated protein kinase (MAPK) signaling pathway. Induction of COX2 and mPGES-1 expression by TLR2 stimulation or Mtb infection was increased after additional stimulation with EP4 agonist. Hence, in Mtb-infected Mφs, PGE2 production induced by pathogen recognition receptors/p38 MAPK signaling is up-regulated by EP4-triggered signaling to maintain an effective PGE2 concentration.—Nishimura, T., Zhao, X., Gan, H., Koyasu, S., and Remold, H. G. The prostaglandin E2 receptor EP4 is integral to a positive feedback loop for prostaglandin E2 production in human macrophages infected with Mycobacterium tuberculosis. PMID:23759445

  4. Prostaglandin E2 modulation of rheumatoid factor synthesis.

    PubMed

    Alvarellos, A; Lipsky, P E; Jasin, H E

    1988-12-01

    We examined the influence of prostaglandin E2 (PGE2) on the in vitro synthesis of rheumatoid factor (RF) by purified human B and T lymphocytes stimulated with Staphylococcus aureus Cowan 1 or pokeweed mitogen (PWM). Supernatants were assayed for total IgM and RF. PGE2 at concentrations of 10(-7) M to 10(-9) M significantly inhibited RF and IgM secretion stimulated by S aureus Cowan 1, a cross-linker of B cell surface Ig. The magnitude of inhibition of RF production was significantly greater than that of total IgM at low PGE2 concentrations (P less than 0.05). In contrast, PWM-stimulated cultures were only minimally inhibited by PGE2 at all concentrations tested. Since cross-linking of surface Ig renders B cells more susceptible to inhibition by PGE2, heat-aggregated IgG (HAIgG) was added to the PWM-stimulated cultures in an attempt to increase the sensitivity of precursors of RF-secreting cells to the inhibitory effects of PGE2. Addition of HAIgG markedly increased PGE2-mediated inhibition of RF synthesis without significantly affecting IgM production. Inhibition could not be overcome by the addition of soluble T helper cell factors, indicating that PGE2-mediated suppression was not the result of an inhibitory action of T helper cells. When lymphocytes from patients with rheumatoid arthritis were examined, HAIgG was found to be unable to induce sensitivity to PGE2-mediated inhibition of responsiveness. These results suggest that down-regulation of RF synthesis requires both cross-linking of surface Ig and the influence of PGE2. Abnormalities in this immunoregulatory mechanism may explain the ongoing production of RF in patients with rheumatoid arthritis. PMID:3264162

  5. Demonstration that circulating 1 alpha, 25-dihydroxyvitamin D is loosely regulated in normal children.

    PubMed Central

    Stern, P H; Taylor, A B; Bell, N H; Epstein, S

    1981-01-01

    The effects of vitamin D, 2.5 mg (100,000 U)/d for 4 d, on serum calcium, serum 25-hydroxyvitamin D (25-OHD) and serum 1 alpha, 25-dihydroxyvitamin D (1 alpha, 25(OH)2D) were compared in 24 normal adults and 12 normal children. The daily dose of vitamin D was 1,500 U/kg body wt in children weighing less than 45 kg. Vitamin D increased mean serum calcium from 9.5 +/- 0.1 to 9.8 +/- 0.1 mg/dl (P less than 0.05), increased mean serum phosphorus from 4.6 +/- 0.1 to 5.0 +/- 0.1 mg/dl (P less than 0.01), increased mean serum 25-OHD from 25 +/- 3 to 34 +/- 4 ng/ml (P less than 0.001), and increased mean serum 1 alpha, 25(OH)2D from 34 +/- 3 to 42 +/- 4 pg/ml (P less than 0.02) in children. In contrast, vitamin D increased mean serum 25-OHD from 18 +/- 2 to 39 +/- 6 ng/ml (P less than 0.001) and did not change mean serum calcium (9.4 +/- 0.1 vs. 9.5 +/- 0.1 mg/dl), mean serum phosphorus (4.0 +/- 0.1 vs. 4.1 +/- 0.1 mg/dl), or mean serum 1 alpha, 25(OH)2D (31 +/- 2 vs. 29 +/- 3 pg/ml) in adults. Mean serum 1 alpha, 25(OH)2D was significantly higher after vitamin D in children than in adults (P less than 0.02). These results provide evidence that circulating 1 alpha, 25(OH)2D is not as tightly regulated in children as it is in adults. This difference in regulation could account in part for the higher values for serum 1 alpha, 25(OH)2D observed in children. PMID:6975284

  6. Increased HIF1 alpha in SDH and FH deficient tumors does not cause microsatellite instability.

    PubMed

    Lehtonen, Heli J; Mäkinen, Markus J; Kiuru, Maija; Laiho, Päivi; Herva, Riitta; van Minderhout, Ivonne; Hogendoorn, Pancras C W; Cornelisse, Cees; Devilee, Peter; Launonen, Virpi; Aaltonen, Lauri A

    2007-09-15

    Germline mutations in nuclear genes encoding mitochondrial enzymes fumarate hydratase (FH) and succinate dehydrogenase (subunits SDHB/C/D) have been implicated in the development of tumor syndromes referred to as hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary paragangliomatosis (HPGL), respectively. FH and SDH are operating in the tricarboxylic acid cycle (the TCA cycle, the Krebs cycle). In the FH and SDH deficient tumors, accumulation of the substrates, fumarate and succinate, has been shown to cause stabilization of hypoxia inducible factor 1 alpha (HIF1 alpha). According to recent studies, HIF1 alpha could contribute to the hypoxia induced genomic instability seen in many cancers, through repression of mismatch repair (MMR) protein MSH2. In this study, in agreement with previous works, we found HIF1 alpha to be moderately or highly stabilized in 67% (16/24) and 77% (48/62) of HLRCC tumors and SDHB/C/D paragangliomas (PGL) and pheochromocytomas (PHEO), respectively. In addition, a set of 54 other familial and nonfamilial PGLs/PHEOs were studied. Moderately or highly stabilized HIF1 alpha was present in 68% (26/38) of the PGLs but in PHEOs (n = 16) no such pattern was observed. We then analyzed the suggested link between HIF1 alpha stabilization and MSH2 repression, in HLRCC and HPGL tumor material. No microsatellite instability (MSI) or lack of MSH2 expression was, however, observed. Thus we failed to provide in vivo evidence for the proposed link between HIF1 alpha stabilization and functional MMR deficiency, in TCAC deficient tumors. PMID:17520677

  7. Involvement of net and Hif1alpha in distinct yet intricately linked hypoxia-induced signaling pathways.

    PubMed

    Serchov, Tsvetan; Dubois-Pot-Schneider, Helene; Charlot, Celine; Rösl, Frank; Wasylyk, Bohdan

    2010-07-01

    The present study compares negative Ets transcription factor (Net) and hypoxia-inducible factor 1alpha (HIF1alpha) regulation by hypoxia. Their protein stabilities are differently regulated by hypoxia, defining three periods in the kinetics: normoxia (high Net levels and low HIF1alpha levels), early hypoxia (high levels of Net and HIF1alpha), and late hypoxia (degradation of Net and HIF1alpha). Modulators of prolyl hydroxylase domain protein (PHD) activity induce a mobility shift of Net, similar to HIF1alpha, suggesting that post-translational modifications of both factors depend on PHD activity. The three PHDs have different roles in the regulation of Net protein levels; PHD1 and PHD3 are involved in the stabilization of Net, whereas PHD2 controls its degradation in late hypoxia. Net physically interacts with PHD2 in hypoxia, whereas PHD1 and PHD3 bind to Net in normoxia and hypoxia. Under the same conditions, PHD2 and PHD3 regulate both HIF1alpha stabilization in early hypoxia and its degradation at late hypoxia, whereas PHD1 is involved in HIF1alpha degradation in late hypoxia. We describe interconnections between the regulation of both Net and HIF1alpha at the protein level. Evidence is provided for a direct physical interaction between Net and HIF1alpha and indirect transcriptional regulation loops that involve the PHDs. Taken together our results indicate that Net and HIF1alpha are components of distinct signaling pathways that are intricately linked. PMID:20427288

  8. Separate and combined effects of recombinant interleukin-1 alpha and gamma interferon on antibacterial resistance.

    PubMed Central

    Kurtz, R S; Young, K M; Czuprynski, C J

    1989-01-01

    Our laboratory has previously reported that administration of murine recombinant interleukin 1 alpha (rIL-1 alpha) substantially enhanced the resistance of mice to Listeria monocytogenes infection. Other investigators have reported that gamma interferon (IFN-gamma) plays a pivotal role in antilisteria resistance. In the present study, we have defined doses of human rIL-1 alpha that enhanced the antilisteria resistance of mice. We then addressed the possibility that combined immunotherapy with rIL-1 alpha and recombinant IFN-gamma (rIFN-gamma) might result in an additive or synergistic enhancement of antibacterial resistance. Simultaneous administration of rIL-1 alpha and rIFN-gamma enhanced antilisteria resistance (at 3 days after infection) to a greater extent than did either cytokine alone, although the results did not imply a synergistic action between the two cytokines. Experiments which examined the effects of the timing of cytokine administration indicated that maximal protection was observed when rIL-1 alpha and rIFN-gamma were administered together concomitantly with the L. monocytogenes challenge. When we compared the separate and combined protective effects of rIL-1 alpha and rIFN-gamma throughout the course of a primary L. monocytogenes infection, we observed an additive effect of the two cytokines only at 3 days after challenge, the time at which the peak bacterial burden occurs in the spleens and livers of infected mice. Histopathological comparisons of livers and spleens from cytokine-treated and control listeria-infected mice verified that cytokine treatment reduced the severity of tissue damage in cytokine-treated listeria-infected mice. In an attempt to provide a potential mechanism for the protective effects of rIL-1 alpha and rIFN-gamma administration, we compared levels of colony-stimulating activity in sera from cytokine-treated and control listeria-infected mice. The highest levels of colony-stimulating activity were detected in sera from

  9. Mitochondrial pyruvate dehydrogenase. Molecular cloning of the E1 alpha subunit and expression analysis.

    PubMed Central

    Grof, C P; Winning, B M; Scaysbrook, T P; Hill, S A; Leaver, C J

    1995-01-01

    A polymerase chain reaction-based approach was used to isolate cDNA clones encoding the E1 alpha subunit of the mitochondrial pyruvate dehydrogenase from higher plants. Putative full-length clones were identified on the basis of similarity to E1 alpha sequences from nonplant sources. Southern blot analysis revealed a small family of genes in potato (Solanum tuberosum L.), whereas in cucumber (Cucumis sativus) there are only one or two genes. Tissue-specific variation in the relative amounts of E1 alpha mRNA was observed in northern blot analysis of different potato tissues, with the highest steady-state transcript levels found in floral tissue. Measurement of pyruvate dehydrogenase activity in cucumber cotyledons showed that there is a transient increase to a maximum at 4 to 5 d postimbibition. Western blot analysis revealed that the amount of E1 alpha protein also peaks at this time. Steady-state transcript levels in germinating cucumber cotyledons also show transient accumulation, peaking 2 d postimbibition. These data are consistent with regulation of E1 alpha at the level of transcription and/or mRNA stability in postgerminative cucumber cotyledons. PMID:7659754

  10. Requirement of cyclooxygenase-2 expression and prostaglandins for human prostate cancer cell invasion.

    PubMed

    Nithipatikom, Kasem; Isbell, Marilyn A; Lindholm, Paul F; Kajdacsy-Balla, Andre; Kaul, Sushma; Campell, William B

    2002-01-01

    The PC-3 Low Invasive cells and the PC-3 High Invasive cells were used to investigate the correlation of the COX-2 expression and its arachidonic acid metabolites, prostaglandins, with their invasiveness through Matrigel using a Boyden chamber assay. The COX-2 expression in PC-3 High Invasive cells was approximately 3-fold higher than in PC-3 Low Invasive cells while the COX-1 expression was similar in both cell sublines. When incubated with arachidonic acid, PGE2 was the major prostaglandin produced by these cells. PC-3 High Invasive cells produced PGE2 approximately 2.5-fold higher than PC-3 Low Invasive cells. PGD2 was the second most abundant prostaglandin produced by these cells. Both indomethacin (a nonspecific COX inhibitor) and NS-398 (a specific COX-2 inhibitor) inhibited the production of prostaglandins and the cell invasion. PGE2 alone did not induce the cell invasion of PC-3 Low Invasive cells. However, PGE2 reversed the inhibition of cell invasion by NS-398 and enhanced the cell invasion of the PC-3 High Invasive cells. In contrast, PGD2 slightly inhibited the cell invasion. These results suggest that in the PC-3 Low Invasive cells, COX-2-derived PGE2 may not be sufficient to induce cell invasion while in the PC-3 High Invasive cells, PGE2 may be sufficient to act as an enhancer for the cell invasion. Further, PGD2 may represent a weak inhibitor and counteracts the effect of PGE2 in the cell invasion. PMID:12498388

  11. Screening of plants used by Southern African traditional healers in the treatment of dysmenorrhoea for prostaglandin-synthesis inhibitors and uterine relaxing activity.

    PubMed

    Lindsey, K; Jäger, A K; Raidoo, D M; van Staden, J

    1999-01-01

    Plants used by Southern African traditional healers for the treatment of menstrual pains were screened for prostaglandin-synthesis inhibitors and the ability to reduce isolated uterine muscle contraction using the cyclooxygenase and in vitro uterine bioassays respectively. Prostaglandins are synthesized from arachidonic acid and the enzyme that drives this reaction is cyclooxygenase. The excessive production of prostaglandins by the myometrium and endometrium induces uterine contractions. Inhibition of cyclooxygenase and hence of the prostaglandin biosynthetic pathway may lead to relief of menstrual pain. Ten plants used by traditional healers for menstrual pains were assayed for cyclooxygenase inhibitory activity. Several plant extracts exhibited high inhibitory activity in the assay. The highest activities were obtained with ethanolic extracts of Siphonochilus aethiopicus, Cenchrus ciliaris and Solanum mauritianum. Generally ethanolic extracts gave higher activity than the aqueous extracts. None of the ethanolic plant extracts were able to relax or reduce the contractions of the precontracted guinea pig uterus. PMID:10075117

  12. Control of cell cycle by metabolites of prostaglandin D2 through a non-cAMP mediated mechanism

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.; Fukushima, M.

    1993-01-01

    The dehydration products of PGD2, 9-deoxy-9 prostaglandin D2(PGJ2), 9-deoxy-delta 9, delta 12, delta 13 dehydroprostaglandin D2 (delta 12 PGJ2), and PGA2 all contain an unsaturated cyclopentenone structure which is characteristic of prostaglandins which effectively inhibit cell growth. It has been suggested that the action of the inhibitory prostaglandins may be through a cAMP mechanism. In this study, we use S49 wild type (WT) and adenylate cyclase variant (cyc-) cells to show that PGD2 and PGJ2 are not acting via a cyclic AMP mechanism. First, the increase in cyclic AMP in wild type S-49 cells is not proportional to its effects on DNA synthesis. More importantly, when S-49 cyc- cells were exposed to PGJ2, the adenylate cyclase (cyc-) mutant had decreased DNA synthesis with no change in its nominal cAMP content. Short-term (2 hours or less) exposure of the cyc- cells to prostaglandin J2 caused an inhibition of DNA synthesis. PGJ2 caused cytolysis at high concentrations. Long-term exposure (>14 hrs) of the cells to PGJ2, delta 12PGJ2 or delta 12, delta 14PGJ2 caused a cell cycle arrest in G1 demonstrating a cell cycle specific mechanism of action for growth inhibition by naturally occurring biological products independent of cAMP.

  13. HIF-1{alpha} is necessary to support gluconeogenesis during liver regeneration

    SciTech Connect

    Tajima, Toshihide; Goda, Nobuhito; Fujiki, Natsuko; Hishiki, Takako; Nishiyama, Yasumasa; Senoo-Matsuda, Nanami; Shimazu, Motohide; Soga, Tomoyoshi; Yoshimura, Yasunori; Johnson, Randall S.; Suematsu, Makoto

    2009-10-02

    Coordinated recovery of hepatic glucose metabolism is prerequisite for normal liver regeneration. To examine roles of hypoxia inducible factor-1{alpha} (HIF-1{alpha}) for hepatic glucose homeostasis during the reparative process, we inactivated the gene in hepatocytes in vivo. Following partial hepatectomy (PH), recovery of residual liver weight was initially retarded in the mutant mice by down-regulation of hepatocyte proliferation, but occurred comparably between the mutant and control mice at 72 h after PH. At this time point, the mutant mice showed lowered blood glucose levels with enhanced accumulation of glycogen in the liver. The mutant mice exhibited impairment of hepatic gluconeogenesis as assessed by alanine tolerance test. This appeared to result from reduced expression of PGK-1 and PEPCK since 3-PG, PEP and malate were accumulated to greater extents in the regenerated liver. In conclusion, these findings provide evidence for roles of HIF-1{alpha} in the regulation of gluconeogenesis under liver regeneration.

  14. Murine model of otitis media with effusion: immunohistochemical demonstration of IL-1 alpha antigen expression.

    PubMed

    Johnson, M D; Contrino, A; Contrino, J; Maxwell, K; Leonard, G; Kreutzer, D

    1994-09-01

    Recent studies have suggested that cytokines likely play a central role in the formation and maintenance of otitis media with effusion (OME). Currently, there is no immunologically defined animal model for the study of cytokines as they contribute to the formation of OME. In the present study, a murine model of OME, using eustachian tube blockage via an external surgical approach, was developed. The murine model temporal bone histology appears to mimic the histology found in chronic otitis media with effusion in humans. Additionally, using this murine model, interleukin-1 alpha (IL-1 alpha) expression was detected in the middle ear using standard immunohistochemical techniques. IL-1 alpha seemed localized to the epithelial lining of the middle ear as well as 5% to 10% of inflammatory cells. This model should provide the necessary tool to further study the immunologic aspects of OME. PMID:8072363

  15. Blockade of prostaglandin E1 hyperthermia by sodium salicylate given into the ventral septal area of the rat brain.

    PubMed Central

    Alexander, S J; Cooper, K E; Veale, W L

    1987-01-01

    1. Sodium salicylate (30.0 micrograms microliter-1) or artificial cerebrospinal fluid (ACSF) was infused bilaterally into the ventral septal area (v.s.a.) of the unrestrained rat for 1 h before and 1 h after the injection of prostaglandin E1 at a concentration of 20.0 ng microliter-1 into a lateral cerebral ventricle. 2. During control (ACSF) infusions, 200.0 ng of prostaglandin E1 evoked a hyperthermic response (0.95 +/- 0.16 degrees C). During sodium salicylate infusions, the prostaglandin E1-evoked hyperthermia was significantly reduced (P less than 0.025) to 0.31 +/- 0.16 degrees C. 3. The fever index (degrees C h for 1.0 h) during the infusion of sodium salicylate was reduced 66% below that of control infusions (P less than 0.01). 4. These data indicate that sodium salicylate infused in the v.s.a. of rats can antagonize a prostaglandin E-evoked hyperthermia. This suggests that there may be an additional mechanism of action for sodium salicylate antipyresis other than inhibition of prostaglandin E synthesis. PMID:3656145

  16. Prostaglandins and mechanisms of preterm birth.

    PubMed

    Challis, John R G; Sloboda, Deborah M; Alfaidy, Nadia; Lye, Steven J; Gibb, William; Patel, Fal A; Whittle, Wendy L; Newnham, John P

    2002-07-01

    Increased uterine contractility at term and preterm results first from activation and then stimulation of the myometrium. Activation can be provoked by mechanical stretch of the uterus, and by an endocrine pathway resulting from increased activity of the fetal hypothalamic-pituitary-adrenal axis. In sheep fetuses, increased cortisol output during pregnancy regulates expression of prostaglandin synthase type 2 (PGHS-2) in the placenta in an oestrogen-independent manner, resulting in increased concentrations of prostaglandin E2 (PGE2) in the fetal circulation. Later increases in maternal uterine expression of PGHS-2 require increases in oestrogen and lead to increased concentrations of PGF(2alpha) in the maternal circulation. Thus, regulation of PGHS-2 at term is differentially controlled in fetal (trophoblast) and maternal (uterine epithelium) tissue. This difference may reflect expression of glucocorticoid receptor but not oestrogen receptor (ER) in placental trophoblast cells. In women, cortisol also contributes to increased prostaglandin production in fetal tissues through upregulation of PGHS-2 (amnion and chorion) and downregulation of 15-OH prostaglandin dehydrogenase (PGDH; chorion trophoblasts). The effect of cortisol on expression of PGDH in the chorion reverses a tonic stimulatory effect of progesterone, potentially through a paracrine or autocrine action. In membranes, cortisol may be derived from cortisone through activity of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1, in addition to secretion from the maternal or fetal adrenal glands. In placenta, 11beta-HSD-2 oxidase activity predominates and expression of this enzyme is reduced with hypoxaemia and in placentae from pre-eclamptic pregnancies. In these circumstances, increased concentrations of maternal cortisol may cross into the fetal compartment, contributing to growth restriction and programming later life disease. PMID:12090913

  17. Cyclooxygenase-2 prostaglandins mediate anandamide-inhibitory action on nitric oxide synthase activity in the receptive rat uterus.

    PubMed

    Sordelli, Micaela S; Beltrame, Jimena S; Cella, Maximiliano; Franchi, Ana M; Ribeiro, Maria Laura

    2012-06-15

    Anandamide, an endocannabinoid, prostaglandins derived from cyclooxygenase-2 and nitric oxide synthesized by nitric oxide synthase (NOS), are relevant mediators of embryo implantation. We adopted a pharmacological approach to investigate if anandamide modulated NOS activity in the receptive rat uterus and if prostaglandins mediated this effect. As we were interested in studying the changes that occur at the maternal side of the fetal-maternal interface, we worked with uteri obtained from pseudopregnant rats. Females were sacrificed on day 5 of pseudopregnancy, the day in which implantation would occur, and the uterus was obtained. Anandamide (2 ng/kg, i.p.) inhibited NOS activity (P<0.001) and increased the levels of prostaglandin E(2) (P<0.001) and prostaglandin F(2α) (P<0.01). These effects were mediated via cannabinoid receptor type 2, as the pre-treatment with SR144528 (10 mg/kg, i.p.), a selective cannabinoid receptor type 2 antagonist, completely reverted anandamide effect on NOS activity and prostaglandin levels. The pre-treatment with a non-selective cyclooxygenase inhibitor (indomethacin 2.5mg/kg, i.p.) or with selective cyclooxygenase-2 inhibitors (meloxicam 4 mg/kg, celecoxib 3mg/kg, i.p.) reverted anandamide inhibition on NOS, suggesting that prostaglandins are derived from cyclooxygenase-2 mediated anandamide effect. Thus, anandamide levels seemed to modulate NOS activity, fundamental for implantation, via cannabinoid receptor type 2 receptors, in the receptive uterus. This modulation depends on the production of cyclooxygenase-2 derivatives. These data establish cannabinoid receptors and cyclooxygenase enzymes as an interesting target for the treatment of implantation deficiencies. PMID:22554772

  18. Characterization of a thromboxane A2/prostaglandin H2 receptor in guinea pig lung membranes using a radioiodinated thromboxane mimetic

    SciTech Connect

    Saussy, D.L. Jr.; Mais, D.E.; Dube, G.P.; Magee, D.E.; Brune, K.A.; Kurtz, W.L.; Williams, C.M. )

    1991-01-01

    Thromboxane A2 (TXA2) and prostaglandin H2 (PGH2) are potent constrictors of airway smooth muscle and may mediate some of the pulmonary effects of leukotrienes. To date, the TXA2/PGH2 receptor in lung has not been well characterized. In this report, we describe the evaluation of the TXA2/PGH2 receptor in guinea pig lung membranes using the new radiolabeled TXA2 mimetic (1S(1 alpha,2 beta(5Z),3 alpha(1E,3S*),4 alpha))-7-(3-(3-hydroxy-4-(4'- iodophenoxy)-1-butenyl)-7-oxabicyclo-(2.2.1)heptan-2-yl)-5-h eptenoic acid (IBOP). IBOP elicited a dose-dependent contraction of guinea pig lung parenchymal strips (EC50 = 3.03 +/- 0.97 nM, three experiments), which was blocked by the TXA2/PGH2 antagonists SQ29548 (pKB = 7.44 +/- 0.2, three experiments), BM13505 (pKB = 6.29 +/- 0.26, three experiments), and I-PTA-OH (pKB = 5.82 +/- 0.36, three experiments). In radioligand binding studies, the binding of (125I)IBOP to guinea pig lung membranes prepared from perfused lungs was saturable, displaceable, and dependent upon protein concentration. Binding was optimal at pH 6.5 and was enhanced by the addition of mono- and divalent cations. The standard assay buffer was 25 mM 3-(N-morpholino)propanesulfonic acid, pH 6.5, 100 mM NaCl, 5 mM MgCl2. Binding was inhibited by pretreatment with dithiothreitol, N-ethylmaleimide, or beta-mercaptoethanol. Binding was unaffected by the addition of guanine nucleotide analogs at concentrations up to 300 microM. Analysis of the time course of binding of (125)IBOP at 30 degrees yielded k-1 = 0.0447 min-1, k1 = 2.49 x 10(8) M-1 min-1, and Kd = k-1/k1 = 180 pM. Computer analysis of equilibrium binding studies using nonlinear methods (LUNDON-1) revealed a single class of noninteracting binding sites with a Kd of 86.9 +/- 11.9 pM and a Bmax of 81.8 +/- 7.7 fmol/mg of protein (three experiments).

  19. Interaction of plant chimeric calcium/calmodulin-dependent protein kinase with a homolog of eukaryotic elongation factor-1alpha

    NASA Technical Reports Server (NTRS)

    Wang, W.; Poovaiah, B. W.

    1999-01-01

    A chimeric Ca2+/calmodulin-dependent protein kinase (CCaMK) was previously cloned and characterized in this laboratory. To investigate the biological functions of CCaMK, the yeast two-hybrid system was used to isolate genes encoding proteins that interact with CCaMK. One of the cDNA clones obtained from the screening (LlEF-1alpha1) has high similarity with the eukaryotic elongation factor-1alpha (EF-1alpha). CCaMK phosphorylated LlEF-1alpha1 in a Ca2+/calmodulin-dependent manner. The phosphorylation site for CCaMK (Thr-257) was identified by site-directed mutagenesis. Interestingly, Thr-257 is located in the putative tRNA-binding region of LlEF-1alpha1. An isoform of Ca2+-dependent protein kinase (CDPK) phosphorylated multiple sites of LlEF-1alpha1 in a Ca2+-dependent but calmodulin-independent manner. Unlike CDPK, CCaMK phosphorylated only one site, and this site is different from CDPK phosphorylation sites. This suggests that the phosphorylation of EF-1alpha by these two kinases may have different functional significance. Although the phosphorylation of LlEF-1alpha1 by CCaMK is Ca2+/calmodulin-dependent, in vitro binding assays revealed that CCaMK binds to LlEF-1alpha1 in a Ca2+-independent manner. This was further substantiated by coimmunoprecipitation of CCaMK and EF-1alpha using the protein extract from lily anthers. Dissociation of CCaMK from EF-1alpha by Ca2+ and phosphorylation of EF-1alpha by CCaMK in a Ca2+/calmodulin-dependent manner suggests that these interactions may play a role in regulating the biological functions of EF-1alpha.

  20. The Role of Prostaglandins in Allergic Lung Inflammation and Asthma

    PubMed Central

    Claar, Dru; Hartert, Tina V.; Peebles, R. Stokes

    2015-01-01

    Prostaglandins are products of the cyclooxygenase pathway of arachidonic acid metabolism. There are five primary prostaglandins, PGD2, PGE2, PGF2, PGI2, and thromboxane B2, all of which signal through distinct seven transmembrane, G-protein coupled receptors. Some prostaglandins may counteract the actions of others, or even the same prostaglandin may have opposing physiologic or immunologic effects, depending on the specific receptor through which it signals. In this review, we will examine the effects of cyclooxygenase activity and the various prostaglandins on allergic airway inflammation and physiology that is associated with asthma. We also highlight the potential therapeutic benefit of targeting prostaglandins in allergic lung inflammation and asthma based on basic science, animal model, and human studies. PMID:25541289

  1. Prostaglandins induce early growth response 1 transcription factor mediated microsomal prostaglandin E2 synthase up-regulation for colorectal cancer progression

    PubMed Central

    Stamatakis, Konstantinos; Jimenez-Martinez, Marta; Jimenez-Segovia, Alba; Chico-Calero, Isabel; Conde, Elisa; Galán-Martínez, Javier; Ruiz, Julia; Pascual, Alejandro; Barrocal, Beatriz; López-Pérez, Ricardo; García-Bermejo, María Laura; Fresno, Manuel

    2015-01-01

    Cyclooxygenase2 (COX2) has been associated with cell growth, invasiveness, tumor progression and metastasis of colorectal carcinomas. However, the downstream prostaglandin (PG)-PG receptor pathway involved in these effects is poorly characterized. We studied the PG-pathway in gene expression databases and we found that PTGS2 (prostaglandin G/H synthase and cyclooxygenase) and PTGES (prostaglandin E synthase) are co-expressed in human colorectal tumors. Moreover, we detected that COX2 and microsomal Prostaglandin E2 synthase 1 (mPGES1) proteins are both up-regulated in colorectal human tumor biopsies. Using colon carcinoma cell cultures we found that COX2 overexpression significantly increased mPGES1 mRNA and protein. This up-regulation was due to an increase in early growth response 1 (EGR1) levels and its transcriptional activity. EGR1 was induced by COX2-generated PGF2α. A PGF2α receptor antagonist, or EGR1 silencing, inhibited the mPGES1 induction by COX2 overexpression. Moreover, using immunodeficient mice, we also demonstrated that both COX2- and mPGES1-overexpressing carcinoma cells were more efficient forming tumors. Our results describe for the first time the molecular pathway correlating PTGS2 and PTGES in colon cancer progression. We demonstrated that in this pathway mPGES1 is induced by COX2 overexpression, via autocrine PGs release, likely PGF2α, through an EGR1-dependent mechanism. This signaling provides a molecular explanation to PTGS2 and PTGES association and contribute to colon cancer advance, pointing out novel potential therapeutic targets in this oncological context. PMID:26498686

  2. Antifibrotic Effects of Noscapine through Activation of Prostaglandin E2 Receptors and Protein Kinase A*

    PubMed Central

    Kach, Jacob; Sandbo, Nathan; La, Jennifer; Denner, Darcy; Reed, Eleanor B.; Akimova, Olga; Koltsova, Svetlana; Orlov, Sergei N.; Dulin, Nickolai O.

    2014-01-01

    Myofibroblast differentiation is a key process in the pathogenesis of fibrotic disease. We have shown previously that differentiation of myofibroblasts is regulated by microtubule polymerization state. In this work, we examined the potential antifibrotic effects of the antitussive drug, noscapine, recently found to bind microtubules and affect microtubule dynamics. Noscapine inhibited TGF-β-induced differentiation of cultured human lung fibroblasts (HLFs). Therapeutic noscapine treatment resulted in a significant attenuation of pulmonary fibrosis in the bleomycin model of the disease. Noscapine did not affect gross microtubule content in HLFs, but inhibited TGF-β-induced stress fiber formation and activation of serum response factor without affecting Smad signaling. Furthermore, noscapine stimulated a rapid and profound activation of protein kinase A (PKA), which mediated the antifibrotic effect of noscapine in HLFs, as assessed with the PKA inhibitor, PKI. In contrast, noscapine did not activate PKA in human bronchial or alveolar epithelial cells. Finally, activation of PKA and the antifibrotic effect of noscapine in HLFs were blocked by the EP2 prostaglandin E2 receptor antagonist, PF-04418948, but not by the antagonists of EP4, prostaglandin D2, or prostacyclin receptors. Together, we demonstrate for the first time the antifibrotic effect of noscapine in vitro and in vivo, and we describe a novel mechanism of noscapine action through EP2 prostaglandin E2 receptor-mediated activation of PKA in pulmonary fibroblasts. PMID:24492608

  3. Identification and Characterization of Novel Microsomal Prostaglandin E Synthase-1 Inhibitors for Analgesia.

    PubMed

    Chandrasekhar, Srinivasan; Harvey, Anita K; Yu, Xiao-Peng; Chambers, Mark G; Oskins, Jennifer L; Lin, Chaohua; Seng, Thomas W; Thibodeaux, Stefan J; Norman, Bryan H; Hughes, Norman E; Schiffler, Matthew A; Fisher, Matthew J

    2016-03-01

    Prostaglandin (PG) E2 plays a critical role in eliciting inflammation. Nonsteroidal anti-inflammatory drugs and selective inhibitors of cyclooxygenase, which block PGE2 production, have been used as key agents in treating inflammation and pain associated with arthritis and other conditions. However, these agents have significant side effects such as gastrointestinal bleeding and myocardial infarction, since they also block the production of prostanoids that are critical for other normal physiologic functions. Microsomal prostaglandin E2 synthase-1 is a membrane-bound terminal enzyme in the prostanoid pathway, which acts downstream of cyclooxygenase 2 and is responsible for PGE2 production during inflammation. Thus, inhibition of this enzyme would be expected to block PGE2 production without inhibiting other prostanoids and would provide analgesic efficacy without the side effects. In this report, we describe novel microsomal prostaglandin E2 synthase-1 inhibitors that are potent in blocking PGE2 production and are efficacious in a guinea pig monoiodoacetate model of arthralgia. These molecules may be useful in treating the signs and symptoms associated with arthritis. PMID:26740668

  4. Antifibrotic effects of noscapine through activation of prostaglandin E2 receptors and protein kinase A.

    PubMed

    Kach, Jacob; Sandbo, Nathan; La, Jennifer; Denner, Darcy; Reed, Eleanor B; Akimova, Olga; Koltsova, Svetlana; Orlov, Sergei N; Dulin, Nickolai O

    2014-03-14

    Myofibroblast differentiation is a key process in the pathogenesis of fibrotic disease. We have shown previously that differentiation of myofibroblasts is regulated by microtubule polymerization state. In this work, we examined the potential antifibrotic effects of the antitussive drug, noscapine, recently found to bind microtubules and affect microtubule dynamics. Noscapine inhibited TGF-β-induced differentiation of cultured human lung fibroblasts (HLFs). Therapeutic noscapine treatment resulted in a significant attenuation of pulmonary fibrosis in the bleomycin model of the disease. Noscapine did not affect gross microtubule content in HLFs, but inhibited TGF-β-induced stress fiber formation and activation of serum response factor without affecting Smad signaling. Furthermore, noscapine stimulated a rapid and profound activation of protein kinase A (PKA), which mediated the antifibrotic effect of noscapine in HLFs, as assessed with the PKA inhibitor, PKI. In contrast, noscapine did not activate PKA in human bronchial or alveolar epithelial cells. Finally, activation of PKA and the antifibrotic effect of noscapine in HLFs were blocked by the EP2 prostaglandin E2 receptor antagonist, PF-04418948, but not by the antagonists of EP4, prostaglandin D2, or prostacyclin receptors. Together, we demonstrate for the first time the antifibrotic effect of noscapine in vitro and in vivo, and we describe a novel mechanism of noscapine action through EP2 prostaglandin E2 receptor-mediated activation of PKA in pulmonary fibroblasts. PMID:24492608

  5. Does Prostaglandin D2 hold the cure to male pattern baldness?

    PubMed Central

    Nieves, Ashley; Garza, Luis A.

    2014-01-01

    Lipids in the skin are the most diverse in the entire human body. Their bioactivity in health and disease is underexplored. Prostaglandin D2 has recently been identified as a factor which is elevated in the bald scalp of men with androgenetic alopecia and has the capacity to decrease hair lengthening. An enzyme which synthesizes it, prostaglandin D2 synthase (PTGDS or lipocalin-PGDS) is hormone responsive in multiple other organs. PGD2 has two known receptors, GPR44 and PTGDR. GPR44 was found to be necessary for the decrease in hair growth by PGD2. This creates an exciting opportunity to perhaps create novel treatments for androgenetic alopecia which inhibit the activity of PTGDS, PGD2 or GPR44. This review discusses the current knowledge surrounding PGD2 and future steps needed to translate these findings into novel therapies for patients with androgenetic alopecia. PMID:24521203

  6. Increased size of solid organs in patients with Chuvash polycythemia and in mice with altered expression of HIF-1alpha and HIF-2alpha.

    PubMed

    Yoon, Donghoon; Okhotin, David V; Kim, Bumjun; Okhotina, Yulia; Okhotin, Daniel J; Miasnikova, Galina Y; Sergueeva, Adelina I; Polyakova, Lydia A; Maslow, Alexei; Lee, Yonggu; Semenza, Gregg L; Prchal, Josef T; Gordeuk, Victor R

    2010-05-01

    Chuvash polycythemia, the first hereditary disease associated with dysregulated oxygen-sensing to be recognized, is characterized by a homozygous germ-line loss-of-function mutation of the VHL gene (VHL(R200W)) resulting in elevated hypoxia inducible factor (HIF)-1alpha and HIF-2alpha levels, increased red cell mass and propensity to thrombosis. Organ volume is determined by the size and number of cells, and the underlying molecular control mechanisms are not fully elucidated. Work from several groups has demonstrated that the proliferation of cells is regulated in opposite directions by HIF-1alpha and HIF-2alpha. HIF-1alpha inhibits cell proliferation by displacing MYC from the promoter of the gene encoding the cyclin-dependent kinase inhibitor, p21(Cip1), thereby inducing its expression. In contrast, HIF-2alpha promotes MYC activity and cell proliferation. Here we report that the volumes of liver, spleen, and kidneys relative to body mass were larger in 30 individuals with Chuvash polycythemia than in 30 matched Chuvash controls. In Hif1a(+/-) mice, which are heterozygous for a null (knockout) allele at the locus encoding HIF-1alpha, hepatic HIF-2alpha mRNA was increased (2-fold) and the mass of the liver was increased, compared with wild-type littermates, without significant difference in cell volume. Hepatic p21(Cip1) mRNA levels were 9.5-fold lower in Hif1a(+/-) mice compared with wild-type littermates. These data suggest that, in addition to increased red cell mass, the sizes of liver, spleen, and kidneys are increased in Chuvash polycythemia. At least in the liver, this phenotype may result from increased HIF-2alpha and decreased p21(Cip1) levels leading to increased hepatocyte proliferation. PMID:20140661

  7. Impaired coactivator activity of the Gly{sub 482} variant of peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) on mitochondrial transcription factor A (Tfam) promoter

    SciTech Connect

    Choi, Yon-Sik; Hong, Jung-Man; Lim, Sunny; Ko, Kyung Soo; Pak, Youngmi Kim . E-mail: ymkimpak@amc.seoul.kr

    2006-06-09

    Mitochondrial dysfunction may cause diabetes or insulin resistance. Peroxisome proliferation-activated receptor-{gamma} (PPAR-{gamma}) coactivator-1 {alpha} (PGC-1{alpha}) increases mitochondrial transcription factor A (Tfam) resulting in mitochondrial DNA content increase. An association between a single nucleotide polymorphism (SNP), G1444A(Gly482Ser), of PGC-1{alpha} coding region and insulin resistance has been reported in some ethnic groups. In this study, we investigated whether a change of glycine to serine at codon 482 of PGC-1{alpha} affected the Tfam promoter activity. The cDNA of PGC-1{alpha} variant bearing either glycine or serine at 482 codon was transfected into Chang human hepatocyte cells. The PGC-1{alpha} protein bearing glycine had impaired coactivator activity on Tfam promoter-mediated luciferase. We analyzed the PGC-1{alpha} genotype G1444A and mitochondrial DNA (mtDNA) copy number from 229 Korean leukocyte genomic DNAs. Subjects with Gly/Gly had a 20% lower amount of peripheral blood mtDNA than did subjects with Gly/Ser and Ser/Ser (p < 0.05). No correlation was observed between diabetic parameters and PGC-1{alpha} genotypes in Koreans. These results suggest that PGC-1{alpha} variants with Gly/Gly at 482nd amino acid may impair the Tfam transcription, a regulatory function of mitochondrial biogenesis, resulting in dysfunctional mtDNA replication.

  8. Effects of anti-inflammatory agents and some other drugs on prostaglandin biotransport.

    PubMed

    Bito, L Z; Salvador, E V

    1976-08-01

    The inhibitory effects of drugs on prostaglandin biotransport were studied by measuring the concentrative accumulation of 3H by rabbit choroid plexuses, segments of anterior uvea and kidney cortex slices after incubation in tissue culture medium containing 3H-prostaglandin F2 alpha. After 10 minutes of incubation in the absence of an inhibitor, the choroid plexus showed a tissue/medium 3H accumulation ratio of 14 +/- 0.7; after 30 minutes of incubation, the anterior uvea and the kidney cortex slices showed accumulation ratios of 6.4 +/- 0.5 and 5.6 +/- 0.1, respectively. The I50 values for inhibition of 3H accumulation by indomethacin were 10, 8 and 12 muM for the three tissues, respectively. Some related drugs-oxyphenbutazone, D-naproxen, l-naproxen, ibuprofen, phenylbutazone and pirprofen-were also found to be effective inhibitors of 3H accumulation (I50 for anterior uvea, 6-28 muM) whereas aspirin, dexamethasone phosphate and penicillin had an inhibitory effect only at much higher concentrations (I50 0.1-2.0 mM). Papaverine, fursemide and probenecid were approximately as effective as the anti-inflammatory organic acids (I50 0.01-0.1 mM), whereas bromcresol green was at least 10-fold more effective. Diphenhydramine and the nonacidic prostaglandin synthesis inhibitors, phenelzine and paracetamol, showed little (I50 greater than 1 mM) or no inhibitory effect. The inhibition of this transport system by some drugs, most notably nonsteroidal anti-inflammatory organic acids, and consequent alterations in the distribution and disposition of prostaglandins must be taken into account in the development of new anti-inflammatory agents and in the interpretation of the mechansim of action and side effects of such drugs. PMID:948038

  9. HIV-1-infected macrophages induce astrogliosis by SDF-1{alpha} and matrix metalloproteinases

    SciTech Connect

    Okamoto, Mika; Wang, Xin; Baba, Masanori . E-mail: baba@m.kufm.kagoshima-u.ac.jp

    2005-11-04

    Brain macrophages/microglia and astrocytes are known to be involved in the pathogenesis of HIV-1-associated dementia (HAD). To clarify their interaction and contribution to the pathogenesis, HIV-1-infected or uninfected macrophages were used as a model of brain macrophages/microglia, and their effects on human astrocytes in vitro were examined. The culture supernatants of HIV-1-infected or uninfected macrophages induced significant astrocyte proliferation, which was annihilated with a neutralizing antibody to stromal cell-derived factor (SDF)-1{alpha} or a matrix metalloproteinase (MMP) inhibitor. In these astrocytes, CXCR4, MMP, and tissue inhibitors of matrix metalloproteinase mRNA expression and SDF-1{alpha} production were significantly up-regulated. The supernatants of infected macrophages were always more effective than those of uninfected cells. Moreover, the enhanced production of SDF-1{alpha} was suppressed by the MMP inhibitor. These results indicate that the activated and HIV-1-infected macrophages can indirectly induce astrocyte proliferation through up-regulating SDF-1{alpha} and MMP production, which implies a mechanism of astrogliosis in HAD.

  10. Interleukin-1 alpha, interleukin-1 beta and interleukin-8 gene expression in human aural cholesteatomas.

    PubMed

    Kim, C S; Lee, C H; Chung, J W; Kim, C D

    1996-03-01

    Bone destruction is a common characteristic feature of chronic otitis media, especially aural cholesteatoma. A number of immunohistochemical studies have suggested that interleukin-1 (IL-1) may be responsible for cholesteatomatous bone destruction. We designed this study to present the mRNA expression patterns of IL-1 alpha, IL-1 beta, and IL-8, which can induce and activate the leukocyte, the major reservoir of potent proteolytic enzymes. Total RNAs were extracted from aural cholesteatomas, external auditory canal skin (EACS), postauricular skin (PAS), and granulation tissues and transcribed into cDNAs. cDNAs were amplified by using PCR technique with primers for IL-1 alpha, IL-1 beta, IL-8, and beta-actin. Amplified products were hybridized with each internal probe and the relative density was measured. In granulation tissues, the relative density of IL-1 alpha was greater than that of other tissues. The ratio of IL-1 beta and IL-8 of aural cholesteatoma was significantly higher than that of EACS and PAS. We suggest that both of IL-1 alpha and IL-1 beta may play a role in the pathological changes, and that IL-8, which is mainly produced from cholesteatomatous epithelium, may have an important role in the pathological changes of cholesteatomas. PMID:8725537

  11. CHARACTERIZATION AND GENE EXPRESSION OF BABESIA BOVIS ELONGATION FACTOR-1ALPHA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elongation factor 1 alpha (EF-1') is a constitutively expressed, abundant protein that is a key element in eukaryotic protein translation. Because of its high level of transcription, the EF-1''promoter has been utilized to drive exogenous gene expression in transfected cells. In this study, we ident...

  12. Separate necdin domains bind ARNT2 and HIF1{alpha} and repress transcription

    SciTech Connect

    Friedman, Eitan R.; Fan Chenming

    2007-11-09

    PWS is caused by the loss of expression of a set of maternally imprinted genes including NECDIN (NDN). NDN is expressed in post-mitotic neurons and plays an essential role in PWS as mouse models lacking only the Ndn gene mimic aspects of this disease. Patients haploid for SIM1 develop a PW-like syndrome. Here, we report that NDN directly interacts with ARNT2, a bHLH-PAS protein and dimer partner for SIM1. We also found that NDN can interact with HIF1{alpha}. We showed that NDN can repress transcriptional activation mediated by ARNT2:SIM1 as well as ARNT2:HIF1{alpha}. The N-terminal 115 residues of NDN are sufficient for interaction with the bHLH domains of ARNT2 or HIF1{alpha} but not for transcriptional repression. Using GAL4-NDN fusion proteins, we determined that NDN possesses multiple repression domains. We thus propose that NDN regulates neuronal function and hypoxic response by regulating the activities of the ARNT2:SIM1 and ARNT2:HIF1{alpha} dimers, respectively.

  13. Molecular cloning and characterization of ovine IL-1 alpha and IL-1 beta.

    PubMed Central

    Andrews, A E; Barcham, G J; Brandon, M R; Nash, A D

    1991-01-01

    Interleukin-1 (IL-1) is a cytokine with a wide range of effects on a variety of cell types. By hybridization with human IL-1 alpha and IL-1 beta cDNA probes, the corresponding ovine cDNAs were isolated from a stimulated alveolar macrophage cDNA library. The sequences of these cDNAs showed that ovine IL-1 alpha and IL-1 beta encode proteins of 268 and 266 amino acids, respectively, with both the nucleotide and amino acid sequences showing a high degree of homology with their human, mouse and bovine equivalents. In a mammalian COS cell-expression system these cDNAs produced biologically active IL-1. Further experiments demonstrated the importance of sequences within the 3' untranslated portion of the cDNAs in determining the level of expression of these molecules. The analysis of expression of IL-1 alpha- and IL-1 beta-specific mRNA in response to endotoxin, phorbol myristic acid (PMA) or PMA plus ionomycin revealed a distinct pattern of differential regulation of the two genes. From genomic analysis both IL-1 alpha and IL-1 beta appear to exist as single copies in the ovine genome. Images Figure 4 Figure 5 PMID:1769692

  14. Stem cell factor induces HIF-1{alpha} at normoxia in hematopoietic cells

    SciTech Connect

    Pedersen, Malin; Loefstedt, Tobias; Sun Jianmin; Holmquist-Mengelbier, Linda; Pahlman, Sven; Roennstrand, Lars

    2008-12-05

    Signaling by the receptor for stem cell factor (SCF), c-Kit, is of major importance for hematopoiesis, melanogenesis and reproduction, and the biological responses are commonly proliferation and cell survival. Thus, constitutive activation due to c-Kit mutations is involved in the pathogenesis of several forms of cancer, e.g. leukemias, gastrointestinal stromal tumors and testicular tumors. Tumor survival requires oxygen supply through induced neovascularization, a process largely mediated by the vascular endothelial growth factor (VEGF), a prominent target of the transcription factors hypoxia-inducible factor-1 (HIF-1) and HIF-2. Using Affymetrix microarrays we have identified genes that are upregulated following SCF stimulation. Interestingly, many of the genes induced were found to be related to a hypoxic response. These findings were corroborated by our observation that SCF stimulation of the hematopoietic cell lines M-07e induces HIF-1{alpha} and HIF-2{alpha} protein accumulation at normoxia. In addition, SCF-induced HIF-1{alpha} was transcriptionally active, and transcribed HIF-1 target genes such as VEGF, BNIP3, GLUT1 and DEC1, an effect that could be reversed by siRNA against HIF-1{alpha}. We also show that SCF-induced accumulation of HIF-1{alpha} is dependent on both the PI-3-kinase and Ras/MEK/Erk pathways. Our data suggest a novel mechanism of SCF/c-Kit signaling in angiogenesis and tumor progression.

  15. PGC-1{alpha} accelerates cytosolic Ca{sup 2+} clearance without disturbing Ca{sup 2+} homeostasis in cardiac myocytes

    SciTech Connect

    Chen, Min; Wang, Yanru; Qu, Aijuan

    2010-06-11

    Energy metabolism and Ca{sup 2+} handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1{alpha}) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1{alpha} in cardiac Ca{sup 2+} signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1{alpha} via adenoviral transduction. Our data shows that overexpressing PGC-1{alpha} improved myocyte contractility without increasing the amplitude of Ca{sup 2+} transients, suggesting that myofilament sensitivity to Ca{sup 2+} increased. Interestingly, the decay kinetics of global Ca{sup 2+} transients and Ca{sup 2+} waves accelerated in PGC-1{alpha}-expressing cells, but the decay rate of caffeine-elicited Ca{sup 2+} transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca{sup 2+}-ATPase (SERCA2a), but not Na{sup +}/Ca{sup 2+} exchange (NCX) contribute to PGC-1{alpha}-induced cytosolic Ca{sup 2+} clearance. Furthermore, PGC-1{alpha} induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1{alpha} did not disturb cardiac Ca{sup 2+} homeostasis, because SR Ca{sup 2+} load and the propensity for Ca{sup 2+} waves remained unchanged. These data suggest that PGC-1{alpha} can ameliorate cardiac Ca{sup 2+} cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1{alpha}-calcium handing pathway sheds new light on the role of PGC-1{alpha} in the therapy of cardiac diseases.

  16. Genes for the dimerization cofactor of hepatocyte nuclear factor-1[alpha] (DCOH) are on human and murine chromsomes 10

    SciTech Connect

    Milatovich, A.; Mendel, D.B.; Crabtree, G.R.; Francke, U. )

    1993-04-01

    Hepatocyte nuclear factor-1[alpha] (HNF-1[alpha]; gene symbol, TCF1) forms dimers with itself as well as with HNF-1[beta] and regulates the expression of several liver-specific genes. Recently, a dimerization cofactor of hepatocyte nuclear factor-1[alpha], called DCOH, has been identified. Here, the authors report the chromosomal localization of the genes for this cofactor to chromosomes 10 in both humans and mice by Southern blot analyses of somatic cell hybrids. 25 refs., 1 fig., 2 tabs.

  17. Synthesis and secretion of interleukin-1 alpha and interleukin-1 receptor antagonist during differentiation of cultured keratinocytes.

    PubMed

    Corradi, A; Franzi, A T; Rubartelli, A

    1995-04-01

    Keratinocytes produce interleukin-1 alpha (IL-1 alpha) and the epithelial variant of its inhibitor, interleukin-1 receptor antagonist (icIL-1ra). Both IL-1 alpha and icIL-1ra lack a secretory signal peptide; however, some icIL-1ra is found in the supernatants of cultured keratinocytes. The lack of correlation with the release of the cytosolic enzyme lactate dehydrogenase suggests that icIL-1ra can be actively secreted. Brefeldin A fails to block icIL-1ra release, suggesting that this protein may be externalized by keratinocytes through a leaderless pathway of secretion. Only minute amounts of soluble extracellular IL-1 alpha are detected: however, both IL-1 alpha and icIL-1ra can be released from the external face of the keratinocyte plasma membrane by mild acidic treatment, suggesting that IL-1 alpha can also be secreted by keratinocytes. The observation of membrane-associated IL-1 alpha and icIL-1ra might reflect an autocrine loop of regulation. Support for this hypothesis comes from the finding that keratinocytes, when exposed to exogenous recombinant IL-1 alpha, increase their content in both IL-1 alpha and IL-1ra mRNA. When keratinocytes are subjected to counterflow centrifugal elutriation, three major cell populations are obtained, representing three different degrees of keratinocyte differentiation. Cells from all populations synthesize IL-1 alpha and IL-1ra: however, while IL-1 alpha is uniformly distributed in cells from all maturational stages, IL-1ra accumulates in large, more differentiated keratinocytes. Changes in the ratio of IL-1ra to IL-1 alpha production and secretion by keratinocytes at different degrees of maturation might contribute to the control of growth and differentiation of human skin. PMID:7698236

  18. Coordinated balancing of muscle oxidative metabolism through PGC-1{alpha} increases metabolic flexibility and preserves insulin sensitivity

    SciTech Connect

    Summermatter, Serge; Santos, Gesa

    2011-04-29

    Highlights: {yields} PGC-1{alpha} enhances muscle oxidative capacity. {yields} PGC-1{alpha} promotes concomitantly positive and negative regulators of lipid oxidation. {yields} Regulator abundance enhances metabolic flexibility and balances oxidative metabolism. {yields} Balanced oxidation prevents detrimental acylcarnitine and ROS generation. {yields} Absence of detrimental metabolites preserves insulin sensitivity -- Abstract: The peroxisome proliferator-activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) enhances oxidative metabolism in skeletal muscle. Excessive lipid oxidation and electron transport chain activity can, however, lead to the accumulation of harmful metabolites and impair glucose homeostasis. Here, we investigated the effect of over-expression of PGC-1{alpha} on metabolic control and generation of insulin desensitizing agents in extensor digitorum longus (EDL), a muscle that exhibits low levels of PGC-1{alpha} in the untrained state and minimally relies on oxidative metabolism. We demonstrate that PGC-1{alpha} induces a strictly balanced substrate oxidation in EDL by concomitantly promoting the transcription of activators and inhibitors of lipid oxidation. Moreover, we show that PGC-1{alpha} enhances the potential to uncouple oxidative phosphorylation. Thereby, PGC-1{alpha} boosts elevated, yet tightly regulated oxidative metabolism devoid of side products that are detrimental for glucose homeostasis. Accordingly, PI3K activity, an early phase marker for insulin resistance, is preserved in EDL muscle. Our findings suggest that PGC-1{alpha} coordinately coactivates the simultaneous transcription of gene clusters implicated in the positive and negative regulation of oxidative metabolism and thereby increases metabolic flexibility. Thus, in mice fed a normal chow diet, over-expression of PGC-1{alpha} does not alter insulin sensitivity and the metabolic adaptations elicited by PGC-1{alpha} mimic the beneficial effects of endurance training

  19. Modulation of the Bovine Innate Immune Response by Production of 1alpha,25-Dihydroxyvitamin D3 in Bovine Monocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In cattle, the kidney has been the only known site for production of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) from 25-hydroxyvitamin D3 25(OH)D3 by 1alpha-hydroxylase (1alpha-OHase). However, recent studies have shown that human monocytes express 1alpha-OHase and produce 1,25(OH)2D3 in response to to...

  20. Modular organization and development activity of an Arabidopsis thaliana EF-1 alpha gene promoter.

    PubMed

    Curie, C; Axelos, M; Bardet, C; Atanassova, R; Chaubet, N; Lescure, B

    1993-04-01

    The activity of the Arabidopsis thalana A1 EF-1 alpha gene promoter was analyzed in transgenic Arabidopsis plants. The 5' upstream sequence of the A1 gene and several promoter deletions were fused to the beta-glucuronidase (GUS) coding region. Promoter activity was monitored by quantitative and histochemical assays of GUS activity. The results show that the A1 promoter exhibits a modular organization. Sequences both upstream and downstream relative to the transcription initiation site are involved in quantitative and tissue-specific expression during vegetative growth. One upstream element may be involved in the activation of expression in meristematic tissues; the downstream region, corresponding to an intron within the 5' non-coding region (5'IVS), is important for expression in roots; both upstream and downstream sequences are required for expression in leaves, suggesting combinatorial properties of EF-1 alpha cis-regulatory elements. This notion of specific combinatorial regulation is reinforced by the results of transient expression experiments in transfected Arabidopsis protoplasts. The deletion of the 5'IVS has much more effect on expression when the promoter activity is under the control of A1 EF-1 alpha upstream sequences than when these upstream sequences were replaced by the 35S enhancer. Similarly, a synthetic oligonucleotide corresponding to an A1 EF-1 alpha upstream cis-acting element (the TEF1 box), is able to restore partially the original activity when fused to a TEF1-less EF1-alpha promoter but has no significant effect when fused to an enhancer-less 35S promoter. PMID:8492811

  1. Immunoglobulin G3 and immunoglobulin M isotype plasma levels are influenced by interleukin-1alpha genotype.

    PubMed

    Kilpinen, S; Laine, S; Hulkkonen, J; Hurme, M

    2003-03-01

    The immunoglobulin (Ig) plasma levels are known to be, at least partially, genetically regulated, but all the genes involved are not known. Interleukin-1 (IL-1) is a potent proinflammatory cytokine able to serve as an adjuvant for immune responses. IL-1alpha gene is polymorphic, and at least one of the polymorphisms has been identified in the 5' regulatory region of the promoter, a biallelic base exchange (C-->T) at position -889. We set out to study whether the IL-1alpha genotype might contribute to the genetic component seen in the steady-state antibody levels of healthy individuals. Four hundred healthy blood donors (218 males and 182 females) were genotyped, and the plasma levels of IgM, IgG as well as IgG subclasses were measured. An association was found between IgG3 plasma levels and the IL-1alpha genotype; the 1.1 homozygotes had increased IgG3 levels compared with the 1.2 heterozygotes (P < 0.001 in males and P = 0.04 in females, Mann-Whitney U-test). A similar significant association was also found between IgM plasma levels and the IL-1alpha genotype in males, but it was no longer present in females; the 1.1 homozygotes had higher IgM levels than the 2.2 homozygotes (P = 0.03, Mann-Whitney U-test). The data suggest that IL-1alpha-mediated signals are critical for IgG3 and IgM responses, which are induced by thymus-independent antigens and are important in activating complement. PMID:12641660

  2. Structural and Biochemical Basis for the Binding Selectivity of Peroxisome Proliferator-activated Receptor [gamma] to PGC-1[alpha

    SciTech Connect

    Li, Yong; Kovach, Amanda; Suino-Powell, Kelly; Martynowski, Dariusz; Xu, H. Eric

    2008-07-23

    The functional interaction between the peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) and its coactivator PGC-1{alpha} is crucial for the normal physiology of PPAR{gamma} and its pharmacological response to antidiabetic treatment with rosiglitazone. Here we report the crystal structure of the PPAR{gamma} ligand-binding domain bound to rosiglitazone and to a large PGC-1{alpha} fragment that contains two LXXLL-related motifs. The structure reveals critical contacts mediated through the first LXXLL motif of PGC-1{alpha} and the PPAR{gamma} coactivator binding site. Through a combination of biochemical and structural studies, we demonstrate that the first LXXLL motif is the most potent among all nuclear receptor coactivator motifs tested, and only this motif of the two LXXLL-related motifs in PGC-1{alpha} is capable of binding to PPAR{gamma}. Our studies reveal that the strong interaction of PGC-1{alpha} and PPAR{gamma} is mediated through both hydrophobic and specific polar interactions. Mutations within the context of the full-length PGC-1{alpha} indicate that the first PGC-1{alpha} motif is necessary and sufficient for PGC-1{alpha} to coactivate PPAR{gamma} in the presence or absence of rosiglitazone. These results provide a molecular basis for specific recruitment and functional interplay between PPAR{gamma} and PGC-1{alpha} in glucose homeostasis and adipocyte differentiation.

  3. Integrin cytoplasmic domain-associated protein 1alpha (ICAP-1alpha ) interacts directly with the metastasis suppressor nm23-H2, and both proteins are targeted to newly formed cell adhesion sites upon integrin engagement.

    PubMed

    Fournier, Henri-Noël; Dupé-Manet, Sandra; Bouvard, Daniel; Lacombe, Marie-Lise; Marie, Christiane; Block, Marc R; Albiges-Rizo, Corinne

    2002-06-01

    Cell adhesion-dependent signaling implicates cytoplasmic proteins interacting with the intracellular tails of integrins. Among those, the integrin cytoplasmic domain-associated protein 1alpha (ICAP-1alpha) has been shown to interact specifically with the beta(1) integrin cytoplasmic domain. Although it is likely that this protein plays an important role in controlling cell adhesion and migration, little is known about its actual function. To search for potential ICAP-1alpha-binding proteins, we used a yeast two-hybrid screen and identified the human metastatic suppressor protein nm23-H2 as a new partner of ICAP-1alpha. This direct interaction was confirmed in vitro, using purified recombinant ICAP-1alpha and nm23-H2, and by co-immunoprecipitation from CHO cell lysates over-expressing ICAP-1alpha. The physiological relevance of this interaction is provided by confocal fluorescence microscopy, which shows that ICAP-1alpha and nm23-H2 are co-localized in lamellipodia during the early stages of cell spreading. These adhesion sites are enriched in occupied beta(1) integrins and precede the formation of focal adhesions devoid of ICAP-1alpha and nm23-H2, indicating the dynamic segregation of components of matrix adhesions. This peripheral staining of ICAP-1alpha and nm23-H2 is only observed in cells spreading on fibronectin and collagen and is absent in cells spreading on poly-l-lysine, vitronectin, or laminin. This is consistent with the fact that targeting of both ICAP-1alpha and nm23-H2 to the cell periphery is dependent on beta(1) integrin engagement rather than being a consequence of cell adhesion. This finding represents the first evidence that the tumor suppressor nm23-H2 could act on beta(1) integrin-mediated cell adhesion by interacting with one of the integrin partners, ICAP-1alpha. PMID:11919189

  4. Prostaglandin I2 and prostaglandin E2 modulate human intrarenal artery contractility through prostaglandin E2-EP4, prostacyclin-IP, and thromboxane A2-TP receptors.

    PubMed

    Eskildsen, Morten P; Hansen, Pernille B L; Stubbe, Jane; Toft, Anja; Walter, Steen; Marcussen, Niels; Rasmussen, Lars M; Vanhoutte, Paul M; Jensen, Boye L

    2014-09-01

    Cyclooxygenase inhibitors decrease renal blood flow in settings with decreased effective circulating volume. The present study examined the hypothesis that prostaglandins, prostaglandin E2 (PGE2) and prostacyclin (PGI2), induce relaxation of human intrarenal arteries through PGE2-EP and PGI2-IP receptors. Intrarenal arteries were microdissected from human nephrectomy samples (n=53, median diameter ≈362 μm, 88% viable, 76% relaxed in response to acetylcholine). Rings were suspended in myographs to record force development. In vessels with K(+)-induced tension (EC70: -log [mol/L]=1.36±0.03), PGE2 and PGI2 induced concentration-dependent relaxation (-log EC50: PGE2=7.1±0.3 and PGI2=7.7). The response to PGE2 displayed endothelium dependence and desensitization. Relaxation by PGE2 was mimicked by an EP4 receptor agonist (CAY10598, EC50=6.7±0.2). The relaxation after PGI2 was abolished by an IP receptor antagonist (BR5064, 10(-8) mol/L). Pretreatment of quiescent arteries with PGE2 for 5 minutes (10(-6) mol/L) led to a significant right shift of the concentration-response to norepinephrine (EC50 from 6.6±0.1-5.9±0.1). In intrarenal arteries with K(+)-induced tone, PGE2 and PGI2 at 10(-5) mol/L elicited increased tension. This was abolished by thromboxane receptor (TP) antagonist (S18886, 10(-6) mol/L). A TP agonist (U46619, n=6) evoked tension (EC50=8.1±0.2) that was inhibited by S18886. Polymerase chain reaction and immunoblotting showed EP4, IP, and TP receptors in intrarenal arteries. In conclusion, PGE2 and PGI2 may protect renal perfusion by activating cognate IP and EP4 receptors associated with smooth muscle cells and endothelium in human intrarenal arteries and contribute to increased renal vascular resistance at high pathological concentrations mediated by noncognate TP receptor. PMID:24914192

  5. Stromal cell-derived factor-1{alpha} (SDF-1{alpha}/CXCL12) stimulates ovarian cancer cell growth through the EGF receptor transactivation

    SciTech Connect

    Porcile, Carola; Bajetto, Adriana . E-mail: bajetto@cba.unige.it; Barbieri, Federica; Barbero, Simone; Bonavia, Rudy; Biglieri, Marianna; Pirani, Paolo; Florio, Tullio . E-mail: florio@cba.unige.it; Schettini, Gennaro

    2005-08-15

    Ovarian cancer (OC) is the leading cause of death in gynecologic diseases in which there is evidence for a complex chemokine network. Chemokines are a family of proteins that play an important role in tumor progression influencing cell proliferation, angiogenic/angiostatic processes, cell migration and metastasis, and, finally, regulating the immune cells recruitment into the tumor mass. We previously demonstrated that astrocytes and glioblastoma cells express both the chemokine receptor CXCR4 and its ligand stromal cell-derived factor-1 (SDF-1), and that SDF-1{alpha} treatment induced cell proliferation, supporting the hypothesis that chemokines may play an important role in tumor cells' growth in vitro. In the present study, we report that CXCR4 and SDF-1 are expressed in OC cell lines. We demonstrate that SDF-1{alpha} induces a dose-dependent proliferation in OC cells, by the specific interaction with CXCR4 and a biphasic activation of ERK1/2 and Akt kinases. Our results further indicate that CXCR4 activation induces EGF receptor (EGFR) phosphorylation that in turn was linked to the downstream intracellular kinases activation, ERK1/2 and Akt. In addition, we provide evidence for cytoplasmic tyrosine kinase (c-Src) involvement in the SDF-1/CXCR4-EGFR transactivation. These results suggest a possible important 'cross-talk' between SDF-1/CXCR4 and EGFR intracellular pathways that may link signals of cell proliferation in ovarian cancer.

  6. Protective effect of (±)α-tocopherol on brominated diphenyl ether-47-stimulated prostaglandin pathways in human extravillous trophoblasts in vitro.

    PubMed

    Park, Hae-Ryung; Loch-Caruso, Rita

    2015-10-01

    Brominated diphenyl ether (BDE)-47 is a prevalent flame retardant chemical found in human tissues and is linked to adverse pregnancy outcomes in humans. Because dysregulation of the prostaglandin pathway is implicated in adverse pregnancy outcomes, the present study investigates BDE-47 induction of prostaglandin synthesis in a human extravillous trophoblast cell line, HTR-8/SVneo, examining the hypothesis that BDE-47 increases generation of reactive oxygen species (ROS) to stimulate the prostaglandin response. Treatment with 20 μM BDE-47 significantly increased mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2) at 4, 12 and 24 h, and 24-h treatment significantly increased cyclooxygenase (COX)-2 cellular protein expression and prostaglandin E2 (PGE2) concentration in culture medium. The BDE-47-stimulated PGE2 release was inhibited by the COX inhibitors indomethacin and NS398, implicating COX activity. Exposure to 20 μM BDE-47 significantly increased ROS generation as measured by carboxydichlorofluorescein fluorescence, and this response was blocked by cotreatment with the peroxyl radical scavenger (±)-α-tocopherol. (±)-α-Tocopherol cotreatment suppressed BDE-47-stimulated increases of PGE2 release without significant effects on COX-2 mRNA and protein expression, implicating a role for ROS in post-translational regulation of COX activity. Because prostaglandins regulate trophoblast functions necessary for placentation and pregnancy, further investigation is warranted of BDE-47 impacts on trophoblast responses. PMID:26026498

  7. Diverse Roles of Prostaglandins in Blastocyst Implantation

    PubMed Central

    2014-01-01

    Prostaglandins (PGs), derivatives of arachidonic acid, play an indispensable role in embryo implantation. PGs have been reported to participate in the increase in vascular permeability, stromal decidualization, blastocyst growth and development, leukocyte recruitment, embryo transport, trophoblast invasion, and extracellular matrix remodeling during implantation. Deranged PGs syntheses and actions will result in implantation failure. This review summarizes up-to-date literatures on the role of PGs in blastocyst implantation which could provide a broad perspective to guide further research in this field. PMID:24616654

  8. Prostaglandin E1 in hand angiography

    SciTech Connect

    Levy, J.M.; Joseph, R.B.; Bodell, L.S.; Nykamp, P.W.; Hessel, S.J.

    1983-11-01

    Prostaglandin E1 (PG1) is a rapid, potent vasodilator which, when infused into the arterial system in low doses by bolus injection, has no significant systemic effects and has a relatively long duration of action. Sixty-three hand angiograms were done on 55 patients, comparing PGE1 to tolazoline and to angiograms done with no vasodilation. There was no significant difference between PGE1 and tolazoline in digital artery opacification; however, venous opacification was very significantly better with PGE1. PGE1 should be a drug of choice in hand angiography.

  9. Interactions between ADH and prostaglandins in isolated erythrocyte-perfused rat kidney

    SciTech Connect

    Lieberthal, W.; Vasilevsky, M.L.; Valeri, C.R.; Levinsky, N.G.

    1987-02-01

    Interactions between antidiuretic hormone (ADH) and renal prostaglandins in the regulation of sodium reabsorption and urinary concentrating ability were studied in isolated erythrocyte-perfused rat kidneys (IEPK). In this model, hemodynamic characteristics are comparable to those found in vivo, and tubular morphology is preserved throughout the period of perfusion. (Deamino)-D-arginine vasopressin (dDAVP) markedly reduced fractional sodium excretion (FE/sub Na/) in the IEPK. After indomethacin, FE/sub Na/ fell still further. In the absence of dDAVP indomethacin had no effect on sodium excretion. dDAVP increased urine osmolality in the IEPK. When prostaglandin synthesis was blocked with indomethacin, urinary osmolality increased further. In isolated kidneys perfused without erythrocytes (IPK), dDAVP decreased FE/sub Na/ from 14.5 +/- 1.8% to 9.6 +/- 1.2%. dDAVP increased urine osmolality only modestly in the IPK and indomethacin did not increase concentrating ability further. Thus the IEPK (unlike the IPK) can excrete markedly hypertonic urine in response to ADH. ADH also enhances tubular reabsorption of sodium in the IEPK. Prostaglandins inhibit both these actions of ADH but do not directly affect sodium excretion in the absence of the hormone. Prostaglandius were measured by radioimmunoassay.

  10. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting

    PubMed Central

    Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Alshahrani, Saeed; Brooks, Marybeth; McCormack, Francis X.; Smith, Roger D.; Zahedi, Kamyar

    2016-01-01

    Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO) mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2) and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE) levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2) in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR) reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of sodium and

  11. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    PubMed

    Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Alshahrani, Saeed; Brooks, Marybeth; McCormack, Francis X; Smith, Roger D; Zahedi, Kamyar

    2016-01-01

    Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO) mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2) and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE) levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2) in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR) reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of sodium and

  12. Endogenous interleukin 1 alpha must be transported to the nucleus to exert its activity in human endothelial cells.

    PubMed Central

    Maier, J A; Statuto, M; Ragnotti, G

    1994-01-01

    We have previously shown that the signal peptideless cytokine interleukin 1 alpha (IL-1 alpha) may play a role as an intracellular regulator of human endothelial cell senescence (J. A. M. Maier, P. Voulalas, D. Roeder, and T. Maciag, Science 249:1570-1574, 1990). To investigate the potential intracellular function of IL-1 alpha, transformed endothelial cells were transfected with the human cDNAs that code for the two forms of IL-1 alpha, the precursor molecule IL-1(1-271) and the mature protein IL-1(113-271). The subcellular localization of the two different polypeptides was investigated directly or by using chimeric genes constructed by fusion of different fragments of the IL-1 alpha gene and the beta-galactosidase open reading frames. The IL-1(113-271) protein was cytoplasmic, while IL-1(1-271) was nuclear. The basic cluster at the NH2 terminus of IL-1, KVLKKRR, has been shown to mediate IL-1 alpha nuclear targeting. Moreover, nuclear localization of IL-1 alpha correlates with impaired cell growth and expression of some IL-1 alpha-inducible genes. These results suggest that transport of endogenous IL-1(1-271) into the nucleus is required for it to modulate endothelial cell function. Images PMID:8114717

  13. Hypoxia-inducible factor-1alpha expression in experimental cirrhosis: correlation with vascular endothelial growth factor expression and angiogenesis.

    PubMed

    Bozova, Sevgi; Elpek, Gülsüm Ozlem

    2007-07-01

    Angiogenesis progresses together with fibrogenesis during chronic liver injury. Hypoxia-inducible factor-1alpha (HIF-1alpha), a master regulator of homeostasis, plays a pivotal role in hypoxia-induced angiogenesis through its regulation of vascular endothelial growth factor (VEGF). The association between hypoxia, angiogenesis and VEGF expression has been demonstrated in experimental cirrhosis. However, expression of HIF-1alpha has yet to be reported. The aim of this study was to investigate the significance of HIF-1alpha expression during experimental liver fibrosis and the relationships between HIF-1alpha expression, VEGF expression and angiogenesis. Cirrhosis was induced in male Wistar rats by intraperitoneal administration of diethyl nitrosamine (DEN) (100 mg/kg, once a week). The serial sections from liver tissues were stained with anti-HIF-1alpha, anti-VEGF and anti-CD34 antibodies before being measured by light microscopy. Our results showed that HIF-1alpha expression gradually increases according to the severity of fibrosis (p<0.01). Moreover, its expression was found to be correlated with angiogenesis (r=0.916) and VEGF expression (r=0.969). The present study demonstrates that HIF-1alpha might have a role in the development of angiogenesis via regulation of VEGF during experimental liver fibrogenesis and suggests that this factor could be a potential target in the manipulation of angiogenesis in chronic inflammatory diseases of the liver. PMID:17614845

  14. Prostaglandin I2 Attenuates Prostaglandin E2-Stimulated Expression of Interferon γ in a β-Amyloid Protein- and NF-κB-Dependent Mechanism

    PubMed Central

    Wang, Pu; Guan, Pei-Pei; Yu, Xin; Zhang, Li-Chao; Su, Ya-Nan; Wang, Zhan-You

    2016-01-01

    Cyclooxygenase-2 (COX-2) has been recently identified as being involved in the pathogenesis of Alzheimer’s disease (AD). However, the role of an important COX-2 metabolic product, prostaglandin (PG) I2, in AD development remains unknown. Using mouse-derived astrocytes as well as APP/PS1 transgenic mice as model systems, we firstly elucidated the mechanisms of interferon γ (IFNγ) regulation by PGE2 and PGI2. Specifically, PGE2 accumulation in astrocytes activated the ERK1/2 and NF-κB signaling pathways by phosphorylation, which resulted in IFNγ expression. In contrast, the administration of PGI2 attenuated the effects of PGE2 on stimulating the production of IFNγ via inhibiting the translocation of NF-κB from the cytosol to the nucleus. Due to these observations, we further studied these prostaglandins and found that both PGE2 and PGI2 increased Aβ1–42 levels. In detail, PGE2 induced IFNγ expression in an Aβ1–42-dependent manner, whereas PGI2-induced Aβ1–42 production did not alleviate cells from IFNγ inhibition by PGI2 treatment. More importantly, our data also revealed that not only Aβ1–42 oligomer but also fibrillar have the ability to induce the expression of IFNγ via stimulation of NF-κB nuclear translocation in astrocytes of APP/PS1 mice. The production of IFNγ finally accelerated the deposition of Aβ1–42 in β-amyloid plaques. PMID:26869183

  15. The prostaglandin E2 receptor EP4 is integral to a positive feedback loop for prostaglandin E2 production in human macrophages infected with Mycobacterium tuberculosis.

    PubMed

    Nishimura, Tomoyasu; Zhao, Xiaomin; Gan, Huixian; Koyasu, Shigeo; Remold, Heinz G

    2013-09-01

    Prostaglandin E2 (PGE2) is an important biological mediator involved in the defense against Mycobacterium tuberculosis (Mtb) infection. Previously, we reported that in macrophages (Mϕs), infection with avirulent Mtb H37Ra resulted in inhibition of necrosis by an inhibitory effect on mitochondrial permeability transition via the PGE2 receptor EP2. However, human Mϕs also express EP4, a PGE2 receptor functionally closely related to EP2 that also couples to stimulatory guanine nucleotide binding protein, but the functional differences between EP2 and EP4 in Mtb-infected Mϕs have been unclear. EP4 antagonist addition to H37Ra-infected Mϕs inhibited the expression of cyclooxygenase 2 (COX2) and microsomal prostaglandin E synthase-1 (mPGES-1), which are involved in PGE2 production. Moreover, H37Ra infection induced PGE2 production through the Toll-like receptor (TLR) 2/p38 mitogen-activated protein kinase (MAPK) signaling pathway. Induction of COX2 and mPGES-1 expression by TLR2 stimulation or Mtb infection was increased after additional stimulation with EP4 agonist. Hence, in Mtb-infected Mϕs, PGE2 production induced by pathogen recognition receptors/p38 MAPK signaling is up-regulated by EP4-triggered signaling to maintain an effective PGE2 concentration. PMID:23759445

  16. Antagonism by antipyretics of the hyperthermic effect of a prostaglandin precursor, sodium arachidonate, in the cat.

    PubMed Central

    Clark, W G; Cumby, H R

    1976-01-01

    1. Injection of sodium arachidonate (100-400 mug) into lateral cerebral ventricles of unanaesthetized cats caused shivering and rapid development of dose-related hyperthermic responses. Unless arachidonate is hyperthermogenic per se, this indicates that in vivo formation of prostaglandins, or perhaps an endoperoxide intermediate, can cause hyperthermia. 2. Tolerance gradually developed when arachidonate was administered repeatedly at intervals of 1-7 days. Examination of the brains of several tolerant animals revealed in each case marked enlargement of the lateral ventricles which apparently accounted for the diminished response to arachidonate. 3. Sodium salicylate (40, 160 mg/kg, i.v.) antagonized arachidonate but only after a 3-4 hr latent period. 4. Paracetamol (10, 40 mg/kg, i.v.) reduced the hyperthermic effect of arachidonate but a dose of 40 mg/kg antagonized centrally administered bacterial endotoxin more effectively than it did arachidonate. 5. Indomethacin (40 mug/kg, i.v.) significantly reduced arachidonate-induced hyperthermia in only one of two studies. This reduction was comparable to the hypothermic effect of indomethacin in afebrile animals and was attributed to a non-specific action on thermoregulatory function rather than to inhibition of prostaglandin synthesis. Indomethacin antagonized endotoxin and leucocytic pyrogen to a greater degree than it did arachidonate. 6. Comparison of the relative effectiveness of the antipyretics in blocking hyperthermic responses to pyrogens and to sodium arachidonate indicates that, if prostaglandins do mediate pyrogen-induced fever, these antipyretics exert their primary at a step before prostaglandin synthesis. PMID:950606

  17. Prostaglandin potentiates 5-HT responses in stomach and ileum innervating visceral afferent sensory neurons

    SciTech Connect

    Kim, Sojin; Jin, Zhenhua; Lee, Goeun; Park, Yong Seek; Park, Cheung-Seog; Jin, Young-Ho

    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 often 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 prostaglandin

  18. The Structure of Neurexin 1[alpha] Reveals Features Promoting a Role as Synaptic Organizer

    SciTech Connect

    Chen, Fang; Venugopal, Vandavasi; Murray, Beverly; Rudenko, Gabby

    2014-10-02

    {alpha}-Neurexins are essential synaptic adhesion molecules implicated in autism spectrum disorder and schizophrenia. The {alpha}-neurexin extracellular domain consists of six LNS domains interspersed by three EGF-like repeats and interacts with many different proteins in the synaptic cleft. To understand how {alpha}-neurexins might function as synaptic organizers, we solved the structure of the neurexin 1{alpha} extracellular domain (n1{alpha}) to 2.65 {angstrom}. The L-shaped molecule can be divided into a flexible repeat I (LNS1-EGF-A-LNS2), a rigid horseshoe-shaped repeat II (LNS3-EGF-B-LNS4) with structural similarity to so-called reelin repeats, and an extended repeat III (LNS5-EGF-B-LNS6) with controlled flexibility. A 2.95 {angstrom} structure of n1{alpha} carrying splice insert SS3 in LNS4 reveals that SS3 protrudes as a loop and does not alter the rigid arrangement of repeat II. The global architecture imposed by conserved structural features enables {alpha}-neurexins to recruit and organize proteins in distinct and variable ways, influenced by splicing, thereby promoting synaptic function.

  19. Role of hypoxia-inducible factor 1{alpha} in modulating cobalt-induced lung inflammation.

    PubMed

    Saini, Yogesh; Kim, Kyung Y; Lewandowski, Ryan; Bramble, Lori A; Harkema, Jack R; Lapres, John J

    2010-02-01

    Hypoxia plays an important role in development, cellular homeostasis, and pathological conditions, such as cancer and stroke. There is also growing evidence that hypoxia is an important modulator of the inflammatory process. Hypoxia-inducible factors (HIFs) are a family of proteins that regulate the cellular response to oxygen deficit, and loss of HIFs impairs inflammatory cell function. There is little known, however, about the role of epithelial-derived HIF signaling in modulating inflammation. Cobalt is capable of eliciting an allergic response and promoting HIF signaling. To characterize the inflammatory function of epithelial-derived HIF in response to inhaled cobalt, a conditional lung-specific HIF1alpha, the most ubiquitously expressed HIF, deletion mouse, was created. Control mice showed classic signs of metal-induced injury following cobalt exposure, including fibrosis and neutrophil infiltration. In contrast, HIF1alpha-deficient mice displayed a Th2 response that resembled asthma, including increased eosinophilic infiltration, mucus cell metaplasia, and chitinase-like protein expression. The results suggest that epithelial-derived HIF signaling has a critical role in establishing a tissue's inflammatory response, and compromised HIF1alpha signaling biases the tissue towards a Th2-mediated reaction. PMID:19915160

  20. Nitric oxide synthase stimulates prostaglandin synthesis and barrier function in C. parvum-infected porcine ileum.

    PubMed

    Gookin, Jody L; Duckett, Laurel L; Armstrong, Martha U; Stauffer, Stephen H; Finnegan, Colleen P; Murtaugh, Michael P; Argenzio, Robert A

    2004-09-01

    Cell culture models implicate increased nitric oxide (NO) synthesis as a cause of mucosal hyperpermeability in intestinal epithelial infection. NO may also mediate a multitude of subepithelial events, including activation of cyclooxygenases. We examined whether NO promotes barrier function via prostaglandin synthesis using Cryptosporidium parvum-infected ileal epithelium in residence with an intact submucosa. Expression of NO synthase (NOS) isoforms was examined by real-time RT-PCR of ileal mucosa from control and C. parvum-infected piglets. The isoforms mediating and mechanism of NO action on barrier function were assessed by measuring transepithelial resistance (TER) and eicosanoid synthesis by ileal mucosa mounted in Ussing chambers in the presence of selective and nonselective NOS inhibitors and after rescue with exogenous prostaglandins. C. parvum infection results in induction of mucosal inducible NOS (iNOS), increased synthesis of NO and PGE2, and increased mucosal permeability. Nonselective inhibition of NOS (NG-nitro-L-arginine methyl ester) inhibited prostaglandin synthesis, resulting in further increases in paracellular permeability. Baseline permeability was restored in the absence of NO by exogenous PGE2. Selective inhibition of iNOS [L-N6-(1-iminoethyl)-L-lysine] accounted for approximately 50% of NOS-dependent PGE2 synthesis and TER. Using an entire intestinal mucosa, we have demonstrated for the first time that NO serves as a proximal mediator of PGE2 synthesis and barrier function in C. parvum infection. Expression of iNOS by infected mucosa was without detriment to overall barrier function and may serve to promote clearance of infected enterocytes. PMID:15155179

  1. Importance of adipocyte cyclooxygenase-2 and prostaglandin E2-prostaglandin E receptor 3 signaling in the development of obesity-induced adipose tissue inflammation and insulin resistance.

    PubMed

    Chan, Pei-Chi; Hsiao, Fone-Ching; Chang, Hao-Ming; Wabitsch, Martin; Hsieh, Po Shiuan

    2016-06-01

    We examined the involvement of adipocyte cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2)-prostaglandin E receptor (EP)3-mediated signaling during hypertrophy and hypoxia in the development of obesity-associated adipose tissue (AT) inflammation and insulin resistance. The experiments were conducted with high-fat diet (HFD)-induced obese rats, db/db mice, human subjects, and 3T3-L1 and the human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes; the groups were treated with selective inhibitors of COX-2 [celecoxib 30 mg/kg, half maximal inhibitory concentration (IC50) ≈ 0.04 µM] and EP3 (L-798106 100 µg/kg, IC50 ≈ 0.5 µM) or a short interfering RNA. There were strong, positive correlations between adipocyte COX-2 and EP3 gene expressions and the AT TNF-α and monocyte chemotactic protein-1 contents and the homeostatic model assessment for insulin resistance in HFD-induced obese rats, as well as body mass index in human subjects. Treatment with COX-2 and EP3 inhibitors significantly reversed AT inflammatory gene and protein expressions (-50%) and impaired glucose and insulin tolerance in db/db mice. COX-2 inhibition diminished the chemotaxis of adipocytes isolated from HFD rats to macrophages and T cells. Targeting inhibition of adipocyte COX-2 and EP3 during hypertrophy and hypoxia reversed the release of the augmented proinflammatory adipokines and the diminished adiponectin and also suppressed NF-κB and hypoxia-inducible factor-1α transcription activation. These findings suggest that adipocyte COX-2 PGE2-EP3-mediated signaling is crucially involved in the development of obesity-associated AT inflammation and insulin resistance.-Chan, P.-C., Hsiao, F.-C., Chang, H.-M., Wabitsch, M., Hsieh, P. S. Importance of adipocyte cyclooxygenase-2 and prostaglandin E2-prostaglandin E receptor 3 signaling in the development of obesity-induced adipose tissue inflammation and insulin resistance. PMID:26932930

  2. Prostaglandin signaling suppresses beneficial microglial function in Alzheimer's disease models.

    PubMed

    Johansson, Jenny U; Woodling, Nathaniel S; Wang, Qian; Panchal, Maharshi; Liang, Xibin; Trueba-Saiz, Angel; Brown, Holden D; Mhatre, Siddhita D; Loui, Taylor; Andreasson, Katrin I

    2015-01-01

    Microglia, the innate immune cells of the CNS, perform critical inflammatory and noninflammatory functions that maintain normal neural function. For example, microglia clear misfolded proteins, elaborate trophic factors, and regulate and terminate toxic inflammation. In Alzheimer's disease (AD), however, beneficial microglial functions become impaired, accelerating synaptic and neuronal loss. Better understanding of the molecular mechanisms that contribute to microglial dysfunction is an important objective for identifying potential strategies to delay progression to AD. The inflammatory cyclooxygenase/prostaglandin E2 (COX/PGE2) pathway has been implicated in preclinical AD development, both in human epidemiology studies and in transgenic rodent models of AD. Here, we evaluated murine models that recapitulate microglial responses to Aβ peptides and determined that microglia-specific deletion of the gene encoding the PGE2 receptor EP2 restores microglial chemotaxis and Aβ clearance, suppresses toxic inflammation, increases cytoprotective insulin-like growth factor 1 (IGF1) signaling, and prevents synaptic injury and memory deficits. Our findings indicate that EP2 signaling suppresses beneficial microglia functions that falter during AD development and suggest that inhibition of the COX/PGE2/EP2 immune pathway has potential as a strategy to restore healthy microglial function and prevent progression to AD. PMID:25485684

  3. Sequential induction of prostaglandin E and D synthases in inflammation

    SciTech Connect

    Schuligoi, Rufina . E-mail: rufina.schuligoi@meduni-graz.at; Grill, Magdalena; Heinemann, Akos; Peskar, Bernhard A.; Amann, Rainer

    2005-09-30

    Enhanced biosynthesis of prostaglandin (PG)D{sub 2} and subsequent formation of 15-deoxy-{delta}{sup 12,14}-PGJ{sub 2} has been suggested to contribute to resolution of inflammation. The primary aim of the present study in mouse heart was, therefore, to determine at the transcriptional level if there is sequential induction of PGE and PGD synthases (S) during inflammation. Expression of interleukin (IL)-1{beta} in heart was enhanced 4 h after systemic inflammation and declined thereafter within 3-5 days to basal levels. In contrast to cyclooxygenase-2 and membrane-bound (m)-PGES-1, which both peaked 4 h after endotoxin administration, hematopoietic (H)-PGDS expression was enhanced only 48 h after endotoxin. The expression of lipocalin-type (L)-PGDS was not significantly influenced. mRNA encoding the putative target of 15-deoxy-{delta}{sup 12,14}-PGJ{sub 2}, peroxisome proliferator-activated receptor {gamma}, was enhanced between 4 and 24 h after induction of inflammation. Treatment of mice with acetylsalicylic acid or indomethacin at doses effective to cause near-complete inhibition of PGE{sub 2} and PGD{sub 2} biosynthesis in heart ex vivo resulted in enhanced expression of IL-1{beta} 24 h after endotoxin administration. These results provide additional support for the hypothesis of a shift towards PGD{sub 2} biosynthesis during resolution of inflammation.

  4. Prostaglandin E2 Prevents Disuse-Induced Cortical Bone Loss

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Akamine, T.; Ke, Hua Zhu; Li, Xiao Jian; Tang, L. Y.; Zeng, Q. Q.

    1992-01-01

    The object of this study was to determine whether prostaglandin E2 (PGE2) can prevent disuse (underloaded)-induced cortical bone loss as well as add extra bone to underloaded bones. Thirteen-month-old retired female Sprague-Dawley breeders served as controls or were subjected to simultaneous right hindlimb immobilization by bandaging and daily subcutaneous doses of 0, 1, 3, or 6 mg PGE2/kg/d for two and six weeks. Histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial shaft sections (proximal to the tibiofibular junction). Disuse-induced cortical bone loss occurred by enlarging the marrow cavity and increasing intracortical porosity. PGE2 treatment of disuse shafts further increased intracortical porosity above that in disuse alone controls. This bone loss was counteracted by enhancement of periosteal and corticoendosteal bone formation. Stimulation of periosteal and corticoendosteal bone formation slightly enlarged the total tissue (cross-sectional) area and inhibited marrow cavity enlargement. These PGE2-induced activities netted the same percentage of cortical bone with a different distribution than the beginning and age related controls. These findings indicate the PGE2-induced increase in bone formation compensated for the disuse and PGE2-induced bone loss, and thus prevented immobilization induced bone loss.

  5. Renal Effects of Prostaglandins and Cyclooxygenase-2 Inhibitors

    PubMed Central

    2008-01-01

    Prostaglandins (PGs) with best-defined renal functions are PGE2 and prostacyclin (PGI2). These vasodilatory PGs increase renal blood flow and glomerular filtration rate under conditions associated with decreased actual or effective circulating volume, resulting in greater tubular flow and secretion of potassium. Under conditions of decreased renal perfusion, the production of renal PGs serves as an important compensatory mechanism. PGI2 (and possibly PGE2) increases potassium secretion mainly by stimulating secretion of renin and activating the renin-angiotensin system, which leads to increased secretion of aldosterone. In addition, PGE2 is involved in the regulation of sodium and water reabsorption and acts as a counterregulatory factor under conditions of increased sodium reabsorption. PGE2 decreases sodium reabsorption at the thick ascending limb of the loop of Henle probably via inhibition of the Na+-K+-2Cl- cotransporter type 2 (NKCC2). Cyclooxygenase inhibitors may enhance urinary concentrating ability in part through effects to upregulate NKCC2 in the thick ascending limb of Henle's loop and aquaporin-2 in the collecting duct. Thus, they may be useful to treat Bartter's syndrome and nephrogenic diabetes insipidus. PMID:24459520

  6. The prostaglandin transporter (PGT) as a potential mediator of ovulation.

    PubMed

    Yerushalmi, Gil M; Markman, Svetlana; Yung, Yuval; Maman, Ettie; Aviel-Ronen, Sarit; Orvieto, Raoul; Adashi, Eli Y; Hourvitz, Ariel

    2016-05-11

    Prostaglandins (PGs) play an important role in the ovulatory process. However, the role of the PG transporter (PGT) in this context remains unknown. We report that the expression of PGT, a transmembrane PG carrier protein, is markedly up-regulated in preovulatory human granulosa cells (GCs). Treatment with human chorionic gonadotropin (hCG), an ovulatory trigger, significantly increases the expression of PGT mRNA and protein in human GCs both in vivo and in vitro. The hCG-induced increase in the expression of PGT in cultured human GCs is mediated via protein kinase A and protein kinase C by way of the extracellular signal-regulated kinase pathway. PGT in cultured human GCs mediates the uptake of PGE2, thereby regulating its extracellular concentration. In vivo treatment of mice with PGT inhibitors effectively blocks ovulation and markedly attenuates the expression of key ovulatory genes. We hypothesize that the inhibition of PGT activity in GCs increases the extracellular concentration of PGE2, the ability of which to exert its ovulatory effect is compromised by desensitization of its cognate receptors. Together, these findings support the idea that PGT is an important mediator of ovulation and that its inhibitors may be viewed as potential candidates for nonhormonal contraception. These findings may also fill the gap in the understanding of PGT signaling, enhance the understanding of ovulatory disorders, and facilitate the treatment of infertility or subfertility in women by using nonsteroidal PG-based therapeutic approaches. PMID:27169804

  7. Enhanced type 1alpha metabotropic glutamate receptor-stimulated phosphoinositide signaling after pertussis toxin treatment.

    PubMed

    Carruthers, A M; Challiss, R A; Mistry, R; Saunders, R; Thomsen, C; Nahorski, S R

    1997-09-01

    The regulation of phosphoinositide hydrolysis by the type 1alpha metabotropic glutamate receptor (mGluR1alpha) was investigated in stably transfected baby hamster kidney (BHK) cells. Incubation of the cells with L-glutamate, quisqualate, and 1-aminocyclopentane-1S, 3R-dicarboxylic acid resulted in a marked accumulation of [3H]inositol monophosphate (InsP1) and inositol-1,4,5-trisphosphate [Ins(1,4,5)P3] mass in a time- and concentration-dependent manner. Pretreatment of BHK-mGluR1alpha cells with pertussis toxin [ 100 ng/ml, 24 hr] led to a dramatic 12-16-fold increase in the accumulation of [3H]InsP1 and a 2-fold increase in Ins(1,4,5)P3 in the absence of added agonist. Although only very low levels (/=75%, and the EC50 shifted leftward by 65-fold [-log EC50 values (molar), 7.26 +/- 0.23 versus 5.45 +/- 0.07; n = 4) in PTX-treated compared with control cells. In contrast, antagonist effects on agonist-stimulated [3H]InsP1 responses were similar in control and PTX-treated BHK-mGluR1alpha cells. These changes in the concentration-effect curves for mGluR agonists are consistent with a model in which the receptor associates with PTX-sensitive inhibitory (Gi/o) and PTX-insensitive stimulatory (Gq/11) G proteins that can each influence PIC activity. The present observations are consistent with a dual regulation of mGluR1alpha-mediated PIC activity that could be fundamental in

  8. Radiation-induced changes in the profile of spinal cord serotonin, prostaglandin synthesis, and vascular permeability

    SciTech Connect

    Siegal, T.; Pfeffer, M.R.

    1995-01-01

    To investigate the profile of biochemical and physiological changes induced in the rat spinal cord by radiation, over a period of 8 months. The thoraco-lumbar spinal cords of Fisher rats were irradiated to a dose of 15 Gy. The rats were then followed and killed at various times afterward. Serotonin (5-HT) and its major metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) were assayed as well as prostaglandin synthesis. Microvessel permeability was assessed by quantitative evaluation of Evans blue dye extravasation. None of the rats developed neurologic dysfunction, and histologic examination revealed only occasional gliosis in the ventral white matter at 240 days after irradiation. Serotonin levels were unchanged at 2, 14, and 56 days after radiation but increased at 120 and 240 days in the irradiated cord segments when compared to both the nonirradiated thoracic and cervical segments (p < 0.01) and age-matched controls (p < 0.03). The calculated utilization ratio of serotonin (5-HIAA/5-HT) remained unchanged. Immediately after radiation (at 3 and 24 h) an abrupt but brief increase in the synthesis of prostaglandin-E{sub 2} (PGE{sub 2}), thromboxane (TXB{sub 2}), and prostacyclin [6 keto-PGF1{alpha} (6KPGF)] was noted, which returned to normal at 3 days. This was followed after 7 and 14 days by a significant fall off in synthesis of all three prostaglandins. Thereafter, at 28, 56, 120, and 240 days, escalated production of thromboxane followed, white prostacyclin synthesis remained markedly reduced (-88% of control level at 240 days). Up to 7 days after radiation the calculated TXB{sub 2}/6KPGF ratio remained balanced, regardless of the observed abrupt early fluctuations in their rate of synthesis. Later, between 7 and 240 days after radiation, a significant imbalance was present which became more pronounced over time. In the first 24 h after radiation, a 104% increase in microvessel permeability was observed which returned to normal by 3 days. 57 refs., 3 figs.

  9. Suppression of newborn natural killer cell activity by prostaglandin E2

    SciTech Connect

    Milch, P.O.; Salvatore, W.; Luft, B.; Baker, D.A.

    1988-10-01

    The effect of prostaglandin E2 on natural killer cell activity of cord blood was examined. Natural killer cell activity, determined by chromium 51 release, was significantly reduced after prostaglandin E2 (1 microgram/ml) treatment. Prostaglandin E2 has been found to enhance the cellular spread of herpesvirus. Thus prostaglandins may enhance viral infections indirectly by suppressing natural killer cell activity.

  10. Phosphorylation of ferredoxin and regulation of renal mitochondrial 25-hydroxyvitamin D-1 alpha-hydroxylase activity in vitro.

    PubMed

    Nemani, R; Ghazarian, J G; Moorthy, B; Wongsurawat, N; Strong, R; Armbrecht, H J

    1989-09-15

    The kidney is the principal physiologic site of production of biologically active 1,25-dihydroxyvitamin D. The 25-hydroxyvitamin D-1 alpha-hydroxylase (1-OHase) activity found in renal mitochondria is under tight hormonal control. Parathyroid hormone stimulates the renal conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D in young animals, which is accompanied by dephosphorylation of ferredoxin (Fx), a component of the mitochondrial 1-OHase enzyme complex (Siegel, N., Wongsurawat, N., and Armbrecht, H. J. (1986) J. Biol. Chem. 261, 16998-17003). The present study investigates the capacity of Fx to be phosphorylated in vitro and to modulate the 1-OHase activity of a reconstituted system. Fx was phosphorylated by renal mitochondrial type II protein kinase. Phosphorylation did not alter Fx mobility on sodium dodecyl sulfate gels but did decrease the pI as measured by isoelectric focusing. Amino acid analysis demonstrated that 1 mol of serine and 1 mol of threonine were phosphorylated per mol of Fx. Peptide mapping of phosphorylated Fx was consistent with phosphorylation of serine 88 and threonine 85 or 97. Fx was selectively dephosphorylated by rabbit skeletal muscle protein phosphatase C2 but not C1. Phosphorylation of Fx significantly inhibited the 1-OHase activity of a reconstituted system consisting of Fx reductase, Fx, and renal mitochondrial cytochrome P-450. These findings suggest that phosphorylation/dephosphorylation of Fx may play a role in modulating renal 1,25-dihydroxyvitamin D production. PMID:2768268

  11. Clinical applications of prostaglandins in Obstetrics and Gynaecology.

    PubMed

    Karim, S M

    1982-10-01

    Although a number of potential practical uses of prostaglandins have been identified, these compounds have so far found clinical applications mainly in Obstetrics and Gynaecology. It is almost 15 years since a prostaglandin was first used for the induction of term labour and prostaglandin E2 is now commercially available for this purpose in many countries. For the termination of second trimester pregnancy, prostaglandins have almost completely replaced other methods previously in use. Other areas where prostaglandins are routinely used or where their uses are being developed, include menstrual induction, preevacuation dilatation of the cervix in the first trimester, termination of pregnancy in cases of missed abortion, intrauterine fetal death and other types of abnormal pregnancies, control of post-partum haemorrhage, treatment of post-partum or post surgical urine retention and ripening of the cervix prior to induction of labour at term. In early studies, prostaglandins E2 and F2 alpha were used for all the applications listed above. In order to increase efficacy and reduce side effects, a number of synthetic analogues were later evaluated for application in selected areas. Those with modification in the 15 and 16 positions of PGE2 and PGF2 alpha molecules have undergone extensive clinical trials and some of these analogues are now in routine use. The current status of the practical applications of prostaglandins in Obstetrics and Gynaecology is reviewed. PMID:6299163

  12. Effects on body temperature of prostaglandins of the A, E and F series on injection into the third ventricle of unanaesthetized cats and rabbits.

    PubMed

    Milton, A S; Wendlandt, S

    1971-10-01

    1. Prostaglandins were injected into the third ventricle of unanaesthetized cats and rabbits whilst rectal temperature was recorded.2. In cats prostaglandin E(1) and E(2) (PGE(1) and PGE(2)) produced hyperthermia which mostly began within a minute of injection and lasted 1 or more hours. With PGE(1) the hyperthermia was shown to be dose dependent between 10 ng and 10 mug (2.8 x 10(-11) and 2.8 x 10(-8)M). The hyperthermia was associated with vigorous shivering, skin vasoconstriction and piloerection. In several experiments a secondary rise in temperature occurred a few hours after the injection but such an effect was sometimes observed with control injections of 0.9% NaCl solution as well.3. None of the other prostaglandins (A(1), F(1alpha), F(2alpha)) examined in cats had an immediate or strong effect on temperature comparable to the hyperthermia produced by PGE(1) and PGE(2).4. In rabbits PGE(1) (2 mug) also caused hyperthermia which began shortly after the injection and lasted for hours. PGF(2alpha) and PGA(1), did not affect temperature.5. In cats it was seen that an intraperitoneal injection of 4-acetamidophenol (paracetamol 50 mg/kg) did not affect the initial strong hyperthermia produced by PGE(1) and PGE(2) but abolished the secondary rise.6. The possibility is discussed that PGE(1) plays a role as a central transmitter or modulator in temperature regulation. PMID:4330929

  13. Lung prostaglandin H synthase and mixed-function oxidase metabolism of nicotine.

    PubMed

    Mattammal, M B; Lakshmi, V M; Zenser, T V; Davis, B B

    1987-09-01

    Nicotine, a major constituent of cigarette smoke, was metabolized by lung microsomes to an aqueous soluble metabolite after addition of arachidonic acid. Similar results were observed with ram seminal vesicle microsomes. Metabolism was inhibited by indomethacin, propylthiouracil and methimazole but not glutathione. Data are consistent with metabolism being catalyzed by the hydroperoxidase activity of prostaglandin H synthase. The product was identified by mass spectrometry as 3-(2,3-dihydro-1-methyl-2-pyrrolyl)pyridine. Addition of NADPH resulted in formation of a different aqueous soluble product and also an organic extractable product. NADPH-dependent products were inhibited by 2-[(2,4-dichloro-6-phenyl)phenoxy]ethylamine, suggesting mixed-function oxidase catalyzed metabolism. The organic soluble product was identified as cotinine. Cotinine formation was inhibited by glutathione. 3-(2,3-dihydro-1-methyl-2-pyrrolyl)Pyridine was identified in urine from rabbits administered nicotine and from a male cigarette smoker. The amount of peroxidatic product in urine from rabbit and humans was 15 and 6%, respectively, that observed for cotinine. Thus, peroxidation represents a new metabolic pathway for nicotine which involves the peroxidatic activity of prostaglandin H synthase. PMID:3116198

  14. Reversible Conjunctival Pigmentation Associated With Prostaglandin Use.

    PubMed

    Choi, Daniel Y; Chang, Robert T; Yegnashankaran, Krishnan; Friedman, Neil J

    2016-01-01

    A 54-year-old Indian male with a diagnosis of ocular hypertension was started on a prostaglandin analog (PGA) in both eyes to lower intraocular pressure. Six years later, he developed progressively increasing bilateral limbal conjunctival hyperpigmentation. Travoprost was discontinued and replaced with brinzolamide and over the next year, the patient's conjunctival pigmentation improved significantly in both the eyes. This case report documents with slit-lamp photography the first case of conjunctival pigmentation associated with PGA use that has been shown to have reversal with discontinuation of the PGA. Because of the widespread use of PGAs, and the evolving nature of the conjunctival pigmentation, clinicians should be aware of this reversible condition when considering biopsy or removal of conjunctival melanocytic lesions. PMID:25967530

  15. Prostaglandins: a report on early clinical studies

    PubMed Central

    Hinman, J. W.

    1970-01-01

    The prostaglandins are a unique group of pharmacologically active lipids which are widely distributed in mammalian tissues and body fluids. The chemistry of this family of compounds has been established in elegant detail. Research quantities of these highly active natural compounds were obtained by enzymatic bioconversion of essential fatty acids and now studies devoted to the elucidation of their physiological roles and their clinical potential are progressing rapidly. Fields of greatest current interest in clinical medicine include renal-cardiovascular research, induction of labour and therapeutic abortion, control of the reproductive cycle (including fertility control), bronchodilation, enhancement of nasal patency and antisecretory activity. Results available to date are too preliminary for many conclusions to be drawn, but are sufficiently encouraging to assure continued and expanding efforts in several fields. PMID:4098885

  16. Expression and regulation of the macrophage inflammatory protein-1 alpha gene by nicotine in rat alveolar macrophages.

    PubMed

    Chong, Inn-Wen; Lin, Shiu-Ru; Hwang, Jhi-Jhu; Huang, Ming-Shyan; Wang, Tung-Heng; Hung, Jen-Yu; Paulauskis, Joseph D

    2002-01-01

    Cigarette smoking causes inflammation mainly confined to the airway and lung. Nicotine is one of the primary constituents in cigarette smoke. Alveolar macrophages apparently play a pivotal role in mediating pulmonary inflammation via the production of chemokines. Macrophage inflammatory protein-1 alpha (MIP-1 alpha), a member of CC chemokines, has been shown to contribute to monocyte/macrophage and neutrophil chemotaxis and activation. Our previous work demonstrated that MIP-1 alpha mRNA expression in macrophages is induced by a variety of stimuli. In the present study, we further investigate whether nicotine can regulate the gene expression of MIP-1 alpha in macrophages and determine the mechanism leading to increased expression. A rat alveolar macrophage (RAM) cell line, NR8383, was treated with nicotine at a dose of 3.1, 31, 310 microM, or 3.1 mM. Northern blot analysis showed that the induction of MIP-1 alpha mRNA expression was dose-dependent. To define the time course of the inflammatory response, RAM cells were exposed to 31 microM nicotine, MIP-1 alpha mRNA was induced as early as 1 h after treatment, was maximally expressed at 4 and 6 hours, and reduced by 8 hours. Western blot analysis demonstrated a single band with an estimated molecular weight of 10 kD for MIP-1 alpha which was induced after nicotine treatment, suggesting that expression of MIP-1 alpha mRNA could reflect in protein synthesis. In addition. the increase in MIP-1 alpha mRNA expression induced by nicotine was attenuated by co-treatment with the antioxidant N-acetylcysteine (NAC), at doses of 10 and 20 mM, suggesting that the induction of MIP-1 alpha mRNA is mediated via the generation of reactive oxygen species (ROS). To further investigate transcriptional regulation of the MIP-1 alpha gene expression, RAM cells were exposed to nicotine. MIP-1 alpha mRNA levels were significantly increased in nuclear RNA preparations, indicating that transcriptional activation is involved in increased

  17. The nectin-1{alpha} transmembrane domain, but not the cytoplasmic tail, influences cell fusion induced by HSV-1 glycoproteins

    SciTech Connect

    Subramanian, Ravi P.; Dunn, Jennifer E.; Geraghty, Robert J. . E-mail: rgeragh@uky.edu

    2005-09-01

    Nectin-1 is a receptor for herpes simplex virus (HSV), a member of the immunoglobulin superfamily, and a cellular adhesion molecule. To study domains of nectin-1{alpha} involved in cell fusion, we measured the ability of nectin-1{alpha}/nectin-2{alpha} chimeras, nectin-1{alpha}/CD4 chimeras, and transmembrane domain and cytoplasmic tail mutants of nectin-1{alpha} to promote cell fusion induced by HSV-1 glycoproteins. Our results demonstrate that only chimeras and mutants containing the entire V-like domain and a link to the plasma membrane conferred cell-fusion activity. The transmembrane domain and cytoplasmic tail of nectin-1 were not required for any viral receptor or cell adhesion function tested. Cellular cytoplasmic factors that bind to the nectin-1{alpha} cytoplasmic tail, therefore, did not influence virus entry or cell fusion. Interestingly, the efficiency of cell fusion was reduced when membrane-spanning domains of nectin-1{alpha} and gD were replaced by glycosylphosphatidylinositol tethers, indicating that transmembrane domains may play a modulatory role in the gD/nectin-1{alpha} interaction in fusion.

  18. Visualization by BiFC of different C/EBP{beta} dimers and their interaction with HP1{alpha} reveals a differential subnuclear distribution of complexes in living cells

    SciTech Connect

    Susperreguy, Sebastian; Prendes, Luciana P.; Desbats, Maria A.; Charo, Nancy L.; Brown, Karen; MacDougald, Ormond A.; Kerppola, Tom; Schwartz, Jessica; Piwien-Pilipuk, Graciela

    2011-04-01

    How the co-ordinated events of gene activation and silencing during cellular differentiation are influenced by spatial organization of the cell nucleus is still poorly understood. Little is known about the molecular mechanisms controlling subnuclear distribution of transcription factors, and their interplay with nuclear proteins that shape chromatin structure. Here we show that C/EBP{beta} not only associates with pericentromeric heterochromatin but also interacts with the nucleoskeleton upon induction of adipocyte differentiation of 3T3-L1 cells. Different C/EBP{beta} dimers localize in different nuclear domains. Using BiFC in living cells, we show that LAP (Liver Activating Protein) homodimers localize in euchromatin and heterochromatin. In contrast, LIP (Liver Inhibitory Protein) homodimers localize exclusively in heterochromatin. Importantly, their differential subnuclear distribution mirrors the site for interaction with HP1{alpha}. HP1{alpha} inhibits LAP transcriptional capacity and occupies the promoter of the C/EBP{beta}-dependent gene c/ebp{alpha} in 3T3-L1 preadipocytes. When adipogenesis is induced, HP1{alpha} binding decreases from c/ebp{alpha} promoter, allowing transcription. Thus, the equilibrium among different pools of C/EBP{beta} associated with chromatin or nucleoskeleton, and dynamic changes in their interaction with HP1{alpha}, play key roles in the regulation of C/EBP target genes during adipogenesis.

  19. Prostaglandin release from human cervical tissue in the first trimester of pregnancy after preoperative dilatation with hygroscopic tents.

    PubMed

    Bokström, H; Wiqvist, N

    1995-10-01

    Preoperative dilatation with hygroscopic tents before first trimester abortion by vacuum aspiration is widely accepted and reduces the risk of early and late complications. A softening effect and a reduced compliance to mechanical dilatation occurs in addition to pure mechanical dilatation of the cervix. If this softening is an effect of local prostaglandin release, however, is unknown. Prostaglandin (PG) release in vitro from cervical biopsies following dilatation in vivo by a synthetic hygroscopic tent (Dilapan) for periods of 4 h and 18 h was compared with that of biopsies from untreated women. No difference was observed between the release of PGE2, PGF2 alpha, or 6-keto-PGF1 alpha. No significant difference was found in the tissue water content between treated and untreated women (83.8% versus 83.2%). Prostaglandins were also extracted from an alternative cervical dilator, Lamicel (a polyvinyl sponge impregnated with magnesium sulfate), and compared with the corresponding values from women pretreated with the cyclooxygenase inhibitor indomethacin before application of the tent. Significantly higher concentrations of PGE2 and PGF2 alpha but not of 6-keto-PGF1 alpha were found in women who had not been indomethacin-treated compared with indomethacin-treated women. Slices of the cervix from non-pregnant women operated upon for benign conditions were divided into an outer stromal layer and an inner layer, including the mucosa, and the PG-release in vitro was measured. The inner layer of the cervix showed a significantly higher release of PGE2 and PGF2 alpha compared with the outer layer. Lamicel treatment before first trimester abortion results in a significant dilatation of the cervix and a reduced compliance to mechanical dilatation, and this study supports the hypothesis that this effect is mediated via a local PG-release from the cervix. It seems reasonable to believe that Dilapan treatment too has the capacity to induce PG-release from the cervix, but this

  20. Flavonoids inhibit cytokine-induced endothelial cell adhesion protein gene expression.

    PubMed Central

    Gerritsen, M. E.; Carley, W. W.; Ranges, G. E.; Shen, C. P.; Phan, S. A.; Ligon, G. F.; Perry, C. A.

    1995-01-01

    Treatment of human endothelial cells with cytokines such as interleukin-1, tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma induces the expression of specific leukocyte adhesion molecules on the endothelial cell surface. Interfering with either leukocyte adhesion or adhesion protein upregulation is an important therapeutic target as evidenced by the potent anti-inflammatory actions of neutralizing antibodies to these ligands in various animal models and in patients. In the present study we report that cotreatment of human endothelial cells with certain hydroxyflavones and flavanols blocks cytokine-induced ICAM-1, VCAM-1, and E-selectin expression on human endothelial cells. One of the most potent flavones, apigenin, exhibited a dose- and time-dependent, reversible effect on adhesion protein expression as well as inhibiting adhesion protein upregulation at the transcriptional level. Apigenin also inhibited IL-1 alpha-induced prostaglandin synthesis and TNF-alpha-induced IL-6 and IL-8 production, suggesting that the hydroxyflavones may act as general inhibitors of cytokine-induced gene expression. Although apigenin did not inhibit TNF-alpha-induced nuclear translocation of NF-kappa B(p50(NFKB1)/p65(RelA)) we found this flavonoid did inhibit TNF-alpha induced beta-galactosidase activity in SW480 cells stably transfected with a beta-galactosidase reporter construct driven by four NF-kappa B elements, suggesting an action on NF-kappa B transcriptional activation. Adhesion of leukocytes to cytokine-treated endothelial cells was blocked in endothelial cells cotreated with apigenin. Finally, apigenin demonstrated potent anti-inflammatory activity in carrageenan induced rat paw edema and delayed type hypersensitivity in the mouse. We conclude that flavonoids offer important therapeutic potential for the treatment of a variety of inflammatory diseases involving an increase in leukocyte adhesion and trafficking. Images Figure 7 Figure 8 Figure 11 PMID:7543732

  1. Novel ring A stereoisomers of 2-methyl-1alpha,25-dihydroxyvitamin D(3) and 2-methyl-20-epi-1alpha,25-dihydroxyvitamin D(3): transactivation of target genes and modulation of differentiation in human promyelocytic leukemia (HL-60) cells.

    PubMed

    Nakagawa, K; Kurobe, M; Ozono, K; Konno, K; Fujishima, T; Takayama, H; Okano, T

    2000-03-15

    We evaluated the biological activity of two sets of ring A stereoisomers of 2-methyl-1alpha,25-dihydroxyvitamin D(3) (2-methyl-1alpha,25(OH)(2)D(3)) and 2-methyl-20-epi-1alpha, 25-dihydroxyvitamin D(3) (2-methyl-20-epi-1alpha,25(OH)(2)D(3)) in terms of the following: transactivation of a rat 25-hydroxyvitamin D(3)-24-hydroxylase gene promoter including two vitamin D response elements (VDREs) and a human osteocalcin gene promoter including a VDRE in transfected human osteosarcoma (MG-63) cells; a vitamin D receptor (VDR)-mediated response using a VDR-GAL4 one-hybrid luciferase reporter system and a retinoid X receptor alpha (RXRalpha)-mediated response using an expressed VDR/RXRalpha-GAL4 modified two-hybrid luciferase reporter system in transfected human epitheloid carcinoma, cervix (HeLa) cells; and modulation of cell surface CD11b antigen expression in human leukemia (HL-60) cells. All the diastereomers of both analogues exhibited unique biological activity profiles depending upon the configurations of the C-1 and C-3 hydroxyl groups, the C-2 methyl group in ring A, and the C-20 methyl group in the side chain. Of the eight possible diastereomers of the 2-methyl analogues, 2alpha-methyl-1alpha,25(OH)(2)D(3) was the most potent and exhibited comparable or even greater biological potency than 1alpha,25(OH)(2)D(3). Of the eight possible diastereomers of the 2-methyl-20-epi analogues, 2alpha-methyl-20-epi-1alpha,25(OH)(2)D(3) was the most potent and exhibited 100- to 200-fold higher transcriptional potencies than 1alpha,25(OH)(2)D(3) and exceptionally high cell regulatory activities. 2beta-methyl-20-epi-1alpha,25(OH)(2)D(3) was nearly as potent as its 2-epimer, 2alpha-methyl-20-epi-1alpha,25(OH)(2)D(3), whereas its 20-epimer, 2beta-methyl-1alpha,25(OH)(2)D(3), was almost completely biologically inactive. In these respects, it can be postulated that the double modification of 2-methyl substitution and 20-epimerization to 1alpha,25(OH)(2)D(3) induces remarkable changes

  2. [Rat cardiomyocyte remodeling after neonatal cryptosporidiosis. II. Elongation, excessive polyploidization and HIF-1alpha overexpression].

    PubMed

    Anatskaia, O V; Sidorenko, N V; Matveev, I V; Kropotov, A V; Vinogradov, A E

    2012-01-01

    Retrospective epidemyological studies evidence that infant diseases leave survivors with an increased susceptibility to cardiovascular diseases in later life. At the same time, the mechanisms of this link remain poorly understood. Based on medical statistics reporting that infectious gastroenteritis is the most common cause of maladies in babies, infants and children, we analysed the effects of moderate cryptosporidial gastroenteritis on the heart and ventricular cardiomyocyte remodelling in rats of the first month of life. The disease was challenged by a worldwide human protozoic pathogen Cryptosporidium parvum (Apicomplexa, Sporozoa). The main symptoms manifested in the growth retardation moderate diarrhea. Using real-time PCR, cytophotometry, confocal microscopy and image analysis, we indicated that cryptosporidiosis was associated, with the atrophy heart and the elongation, narrowing, protein content decrease and hyperpolyploidization of cardiomyocytes and the moderate overexpression of hypoxia inducible factor 1alpha (HIF-1alpha) mRNA. Cardiomyocyte shape remodeling and heart atrophy presented in all age groups. The severity of these changes, hovewer, declined gradually from younger to older groups. In contrast, hyperpolyploidization and HIF-1alpha mRNA overexpression were registered mainly among animals aged between 6 and 13 days, and were barely detected and non-significant in older age groups. In the rat the time period covering 6-13 days after birth is known to coincide with the intensive cardiomyocyte polyploidization and the switch from proliferation to hypertrophy. Thus, our data indicate that neonatal cryptosporidiosis may be potential cardiovascular diseases risk factor and that one of the critical time windows for the growing heart covers the time period when cardiomyocyte undergo polyploidization. PMID:23074852

  3. Effects of Prostaglandin Analogues on Aqueous Humor Outflow Pathways

    PubMed Central

    Winkler, Nelson S.

    2014-01-01

    Abstract Elevated intraocular pressure (IOP) is the most prevalent risk factor for glaucoma. All treatments, whether surgical or pharmaceutical, are aimed at lowering IOP. Prostaglandin analogues are a first line therapy for glaucoma due to their ability to reduce IOP, once-daily dosing, efficacy, and minimal side-effect profile. Whereas prostaglandin analogues have been known to alter aqueous humor outflow through the unconventional (uveoscleral) pathway, more recent evidence suggests their action also occurs through the conventional (trabecular) pathway. Understanding how prostaglandin analogues successfully lower IOP is important, as this information may lead to the discovery of new molecular targets for future therapeutic intervention. This review explores the current understanding of prostaglandin analogue biology as it pertains to IOP reduction and improved aqueous humor outflow facility. PMID:24359106

  4. PGC-1alpha induces dynamic protein interactions on the ERRalpha gene multi-hormone response element nucleosome in kidney cells.

    PubMed

    Wang, Liangli; Li, Yin; Hu, Peng; Teng, Christina T

    2008-12-15

    ERR (oestrogen-related receptor)-alpha modulates the oestrogen signalling pathway and regulates genes participating in the physiological energy balance programme. Oestrogen and PGC-1alpha (peroxisome proliferator-activated receptor-gamma coactivator-1alpha), the master regulator of the energy homoeostasis programme, both regulate the expression of ERRalpha through the MHRE (multi-hormone response element) of the ERRalpha gene. Although the molecular mechanism of oestrogen action on ERRalpha regulation is well characterized, the mechanism of PGC-1alpha induction is unclear. In this study, we examine chromatin structural changes and protein interactions at the MHRE nucleosome in response to PGC-1alpha expression in HK2 human kidney cells. We mapped the nucleosome positions of the ERRalpha gene promoter and examined the changes of histone acetylation in response to PGC-1alpha expression. The interactions of DNA-binding proteins, ERRalpha and ERRgamma, co-activators {CBP [CREB (cAMP-response-element-binding protein)-binding protein], p300, PCAF (p300/CBP-associated factor)}, co-repressor [RIP140 (receptor-interacting protein of 140 kDa)] and RNA polymerase II at the MHRE nucleosome region were investigated over time before and after PGC-1alpha expression in the HK2 cells. We found a dynamic cyclic interaction of these proteins shortly after PGC-1alpha expression and a slower cycling interaction, with fewer proteins involved, 20 h later. By using the siRNA (small interfering RNA) knockdown approach, we discovered that ERRgamma was involved in the initial phase, but not in the later phase, of PGC-1alpha-induced ERRalpha expression. PMID:18673300

  5. Coactivator PGC-1{alpha} regulates the fasting inducible xenobiotic-metabolizing enzyme CYP2A5 in mouse primary hepatocytes

    SciTech Connect

    Arpiainen, Satu; Jaervenpaeae, Sanna-Mari; Manninen, Aki; Viitala, Pirkko; Lang, Matti A.; Pelkonen, Olavi; Hakkola, Jukka

    2008-10-01

    The nutritional state of organisms and energy balance related diseases such as diabetes regulate the metabolism of xenobiotics such as drugs, toxins and carcinogens. However, the mechanisms behind this regulation are mostly unknown. The xenobiotic-metabolizing cytochrome P450 (CYP) 2A5 enzyme has been shown to be induced by fasting and by glucagon and cyclic AMP (cAMP), which mediate numerous fasting responses. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} triggers many of the important hepatic fasting effects in response to elevated cAMP levels. In the present study, we were able to show that cAMP causes a coordinated induction of PGC-1{alpha} and CYP2A5 mRNAs in murine primary hepatocytes. Furthermore, the elevation of the PGC-1{alpha} expression level by adenovirus mediated gene transfer increased CYP2A5 transcription. Co-transfection of Cyp2a5 5' promoter constructs with the PGC-1{alpha} expression vector demonstrated that PGC-1{alpha} is able to activate Cyp2a5 transcription through the hepatocyte nuclear factor (HNF)-4{alpha} response element in the proximal promoter of the Cyp2a5 gene. Chromatin immunoprecipitation assays showed that PGC-1{alpha} binds, together with HNF-4{alpha}, to the same region at the Cyp2a5 proximal promoter. In conclusion, PGC-1{alpha} mediates the expression of CYP2A5 induced by cAMP in mouse hepatocytes through coactivation of transcription factor HNF-4{alpha}. This strongly suggests that PGC-1{alpha} is the major factor mediating the fasting response of CYP2A5.

  6. Retroviral interleukin 1alpha gene transfer in bone marrow stromal cells in a primate model: induction of myelopoiesis stimulation.

    PubMed

    de Revel, Thierry; Becard, Nicolas; Sorg, Tania; Rousseau, Sandrine; Spano, Jean Philippe; Thiebot, Hugues; Methali, Magid; Gras, Gabriel; Le Grand, Roger; Dormont, Dominique

    2002-09-01

    Effects of interleukin 1-alpha (IL-1alpha), a proinflammatory cytokine with pleiotropic activity, in the myelopoietic setting, is mainly linked to its ability to increase haematopoietic growth factor production by bone marrow stromal cells. In order to minimize systemic effects of IL-1alpha therapy, we proposed a model of retroviral IL-1alpha gene transfer within bone marrow stromal cells in the macaque cynomolgus. Invitro, 10-15% of bone marrow stromal cells was effectively transduced by retroviral vector (murine Moloney leukaemia virus-derived) expressing IL-1alpha/LacZ, or LacZ alone as control marker, as assessed by betaGal staining. IL-1alpha gene expression was upregulated [semiquantitative reverse transcription polymerase chain reaction (RT-PCR)] within the transduced cells and the cell supernatant showed an increased production of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage (GM)-CSF (enzyme-linked immunosorbent assay) and an increased clonogenic activity (colony-forming cell assay). Ex vivo autologous expanded IL-1alpha/LacZ transduced bone marrow stromal cells were reinfused in two macaques (and two control animals for LacZ alone as controls), without clinical systemic toxicity; LacZ expression by RT-PCR was detected in one animal of each group between d 4 and 9. A slight increase of the peripheral blood leucocyte counts (both polymorphonuclear cells and monocytes) of the two animals transduced with IL-1alpha/LacZ was observed within 10 d, indicating stimulation of myelopoiesis. PMID:12181061

  7. Free radical oxidation of (E)-retinoic acid by prostaglandin H synthase.

    PubMed

    Samokyszyn, V M; Chen, T; Maddipati, K R; Franz, T J; Lehman, P A; Lloyd, R V

    1995-01-01

    Cooxidative metabolism of all-trans (E)-retinoic acid (RA) by prostaglandin H synthase was investigated employing ram seminal vesicle microsomes (RSVM) or purified, RSVM-derived enzyme. RA was shown to undergo hydroperoxide [H2O2 or 5-phenyl-4-penten-1-yl hydroperoxide (PPHP)]- or arachidonic acid-dependent cooxidation by microsomal prostaglandin H (PGH) synthase as evidenced by UV spectroscopic analysis of reaction mixtures. Cooxidation of RA by microsomal or purified PGH synthase, using PPHP as substrate, was characterized by uptake of dioxygen which was first order with respect to enzyme concentration. Dioxygen uptake was inhibited by the peroxidase reducing substrate 2-methoxyphenol. In addition, O2 uptake was inhibited by the spin trap nitrosobenzene. ESR spin trapping studies, using alpha-phenyl-N-tert-butylnitrone (PBN) as the spin trap, demonstrated the formation of RA-PBN adducts, characterized by hyperfine coupling constants of alpha H = 3.2 G and alpha N = 15.8 G. Reverse phase HPLC analysis of reaction mixtures demonstrated the formation of 4-hydroxy-RA, 5,6-epoxy-RA, 4-oxo-RA, (13Z)-retinoic acid, and other geometric isomers which were identified on the basis of cochromatography with synthetic standards, UV spectroscopy, and/or mass spectrometry. Mechanisms are proposed for the hydroperoxide-dependent, PGH synthase-catalyzed oxidation of RA that are consistent with these results. PMID:7548765

  8. Modulation of Leishmania (L.) amazonensis Growth in Cultured Mouse Macrophages by Prostaglandins and Platelet Activating Factor

    PubMed Central

    Lonardoni, M. V. C.; Barbieri, C. L.; Russo, M.

    1994-01-01

    The role of endogenously synthesized PAF and prostaglandins on the infection of mouse macrophages by Letsbmanta (L.) amazonensis was investigated, as well as the possible correlation between the effects of these inflammatory mediators with nitric oxide production. It was found that pretreatment of macrophages with 10−5 M of the PAF antagonists, BN-52021 or WEB-2086, increased macrophage infection by 17 and 59%, respectively. The cyclooxygenase inhibitor, indomethacin (10 μg/ml), induced a significant inhibition which was reversed by addition of PGE (10-3 M) to the culture medium. These results suggested that the infection of macrophages by leisbmanla is inhibited by PAF and enhanced by prostaglandins and that these mediators are produced by macrophages during this infection. This was confirmed by addition of these mediators to the culture medium before infection; PAF (10−6, 10−9 and 10−12M) reduced significantly the infection whereas PGE2 (10−5 M) induced a marked enhancement. This effect of exogenous PAF on macrophage infection was reversed by the two PAF antagonists used in this study as well as by the inhibitor of nitric oxide synthesis, L-arginine methyl ester (100 mM). Taken together the data suggest that endogenous production of PAF and PGE2 exert opposing effects on Lesbmana–macrophage interaction and that nitric oxide may be involved in the augmented destruction of parasites induced by PAF. PMID:18472932

  9. 2-methoxycinnamaldehyde reduces IL-1beta-induced prostaglandin production in rat cerebral endothelial cells.

    PubMed

    Guo, Jian-You; Huo, Hai-Ru; Yang, Yuan-Xiao; Li, Cang-Hai; Liu, Hong-Bin; Zhao, Bao-Sheng; Li, Lan-Fang; Ma, Yue-Ying; Guo, Shu-Ying; Jiang, Ting-Liang

    2006-11-01

    Prostaglandin E2 (PGE2) works as a common final mediator of the febrile. Guizhi-Tang, one of the most famous traditional Chinese medical formula used to treat influenza, common cold and other pyretic conditions, was previously reported to reduce the production of PGE 2 in rats. 2-Methoxycinnamaldehyde is a principle compound isolated from Guizhi-Tang. The aim of the present study was to investigate the effects of 2-methoxycinnamaldehyde on PGE2 production of rat cerebral endothelial cells (CECs). 2-Methoxycinnamaldehyde dose-dependently inhibited interleukin (IL)-1beta-induced PGE2 production in CECs with IC50 values of 174 microM. IL-1beta stimulation increased the protein, activity and mRNA expression of cyclooxygenase (COX)-2 but not COX-1. 2-Methoxycinnamaldehyde reduced IL-1beta-induced protein and activity of COX-2, but did not influence the COX-2 mRNA expression. Our results show that prostaglandin production in CECs during stimulated conditions is sensitive to inhibition by 2-methoxycinnamaldehyde and suggest that 2-methoxycinnamaldehyde may reduce COX-2 protein level and activity but not COX-2 mRNA. PMID:17077517

  10. Interaction of the human cytomegalovirus particle with the host cell induces hypoxia-inducible factor 1 alpha

    SciTech Connect

    McFarlane, Steven; Nicholl, Mary Jane; Sutherland, Jane S.; Preston, Chris M.

    2011-05-25

    The cellular protein hypoxia-inducible factor 1 alpha (HIF-1{alpha}) was induced after infection of human fibroblasts with human cytomegalovirus (HCMV). HCMV irradiated with ultraviolet light (uv-HCMV) also elicited the effect, demonstrating that the response was provoked by interaction of the infecting virion with the cell and that viral gene expression was not required. Although induction of HIF-1{alpha} was initiated by an early event, accumulation of the protein was not detected until 9 hours post infection, with levels increasing thereafter. Infection with uv-HCMV resulted in increased abundance of HIF-1{alpha}-specific RNA, indicating stimulation of transcription. In addition, greater phosphorylation of the protein kinase Akt was observed, and the activity of this enzyme was required for induction of HIF-1{alpha} to occur. HIF-1{alpha} controls the expression of many cellular gene products; therefore the findings reveal new ways in which interaction of the HCMV particle with the host cell may cause significant alterations to cellular physiology.

  11. Production of Histamine-like and Prostaglandin-Like Substances from Serum Incubated with Rat, Dog, Mouse or Human Tumours

    PubMed Central

    Apps, M. C. P.; Cater, D. B.

    1973-01-01

    When diluted serum was incubated at 37° with finely minced tumour tissue (from rat, dog, mouse or man) there was a fall of haemolytic complement titre (0-30 minutes), the production of a “histamine-like” material (30-90 minutes) and a prostaglandin-like “active lipid” (90-150 minutes). This latter was extracted with ethyl acetate at pH 3 and produced contraction of a rat stomach-fundus-strip preparation. Production of both types of activity was approximately proportional to the quantity of serum in the incubation mixture and to the fall in the haemolytic complement titre. With a constant amount of serum there was an optimum quantity of tumour, above which no further increase of active material was obtained. Aspirin or indomethacin added to the serum abolished the production of the “active lipid” but did not affect the “histamine-like” material. Inhibition of C′1 activity had a similar effect, but inhibition of C′3 abolished the production of both “histamine-like” and “prostaglandin-like” activity. When tumour was incubated with Tyrode's solution, both active fractions were present but their amount did not increase with time. When serum was incubated with liver or muscle from rat or guinea-pig, there was no “production” of either “histamine-like” or “prostaglandin-like” material. PMID:4349540

  12. Regulation of cyclic AMP metabolism by prostaglandins in rabbit cortical collecting tubule cells

    SciTech Connect

    Sonnenburg, W.K.

    1987-01-01

    In the rabbit cortical collecting tubule (RCCT), prostaglandin E/sub 1/ (PGE/sub 1/) and prostaglandin E/sub 2/ (PGE/sub 2/) at 1 nM inhibit arginine-vasopressin (AVP)-induced water reabsorption, while 100 nM PGE/sub 1/ and PGE/sub 2/ alone stimulate water reabsorption. Reported here are studies designed to investigate the molecular basis for the biphasic physiological action of PGE/sub 1/ and PGE/sub 2/ in the collecting duct. In freshly isolated RCCT cells, PGE/sub 1/, PGE/sub 2/, and 16,16-dimethyl-PGE/sub 2/ (DM-PGE/sub 2/) stimulated cAMP synthesis at concentrations ranging from 0.1 to 10 M. Other prostaglandins including the synthetic PGE/sub 2/ analogue, sulprostone, failed to stimulate cAMP synthesis. Moreover, sulprostone did not antagonize PGE/sub 2/-stimulated cAMP formation. In contrast, PGE/sub 2/ and sulprostone at concentrations ranging from 1 to 100 nM, inhibited AVP-induced cAMP accumulation in freshly isolated RCCT cells. PGE/sub 2/, PGE/sub 1/, DM-PGE/sub 2/ and sulprostone at 100 nM were equally effective in inhibiting AVP-induced cAMP formation. Moreover sulprostone inhibited AVP-stimulated adenylate cyclase activity. These results suggest that PGE derivatives mediate either inhibition or activation of adenylate cyclase by stimulating different PGE receptors. To further test this concept, PGE/sub 2/ binding to freshly isolated RCCT cell membranes was characterized. Two different classes of PGE/sub 2/ binding were detected. //sup 3/H/PGE/sub 2/ binding to the high affinity class of sites was increased by the GTP-analogue, GTP S, while pertussis toxin pretreatment blocked the stimulatory action. In contrast, //sup 3/H/ PGE/sub 2/ binding to the low affinity class of sites was decreased by GTP S; this inhibitory effect was not blocked by pertussis toxin pretreatment.

  13. Simulated microgravity upregulates an endothelial vasoconstrictor prostaglandin.

    PubMed

    Sangha, D S; Han, S; Purdy, R E

    2001-08-01

    Endothelial nitric oxide contributes to the vascular hyporesponsiveness to norepinephrine (NE) observed in carotid arteries from rats exposed to simulated microgravity. The goal of the present study was to determine whether a cyclooxygenase product of arachidonic acid also influences vascular responsiveness in this setting. Microgravity was simulated in rats by hindlimb unweighting (HU). After 20 days of HU, carotid arteries were isolated from control and HU-treated rats, and vascular rings were mounted in tissue baths for the measurement of isometric contraction. Two cyclooxygenase inhibitors, indomethacin and ibuprofen, and the selective thromboxane A(2) prostanoid-receptor antagonist, SQ-29548, had no effect on the contraction to NE in control vessels but markedly reduced contraction to NE in HU vessels. When the endothelium was removed, indomethacin no longer had any effect on the NE-induced contraction in HU vessels. In endothelium-intact vessels in the presence of indomethacin, the addition of the nitric oxide synthase inhibitor, N(G)-L-nitro-arginine methyl ester, to the medium bathing HU vessels increased the contraction to NE to the level of that of the control vessels. These results indicate that HU treatment induced two endothelial changes in carotid artery that opposed each other. Nitric oxide activity was increased and was responsible for the vascular hyporesponsiveness to NE. The activity of a vasoconstrictor prostaglandin was also increased, and attenuated the vasodilating effect of nitric oxide. PMID:11457795

  14. Simulated microgravity upregulates an endothelial vasoconstrictor prostaglandin

    NASA Technical Reports Server (NTRS)

    Sangha, D. S.; Han, S.; Purdy, R. E.

    2001-01-01

    Endothelial nitric oxide contributes to the vascular hyporesponsiveness to norepinephrine (NE) observed in carotid arteries from rats exposed to simulated microgravity. The goal of the present study was to determine whether a cyclooxygenase product of arachidonic acid also influences vascular responsiveness in this setting. Microgravity was simulated in rats by hindlimb unweighting (HU). After 20 days of HU, carotid arteries were isolated from control and HU-treated rats, and vascular rings were mounted in tissue baths for the measurement of isometric contraction. Two cyclooxygenase inhibitors, indomethacin and ibuprofen, and the selective thromboxane A(2) prostanoid-receptor antagonist, SQ-29548, had no effect on the contraction to NE in control vessels but markedly reduced contraction to NE in HU vessels. When the endothelium was removed, indomethacin no longer had any effect on the NE-induced contraction in HU vessels. In endothelium-intact vessels in the presence of indomethacin, the addition of the nitric oxide synthase inhibitor, N(G)-L-nitro-arginine methyl ester, to the medium bathing HU vessels increased the contraction to NE to the level of that of the control vessels. These results indicate that HU treatment induced two endothelial changes in carotid artery that opposed each other. Nitric oxide activity was increased and was responsible for the vascular hyporesponsiveness to NE. The activity of a vasoconstrictor prostaglandin was also increased, and attenuated the vasodilating effect of nitric oxide.

  15. Multifactorial regulation of prostaglandin synthesis in preovulatory goldfish ovarian follicles.

    PubMed

    Kellner, R G; Van der Kraak, G

    1992-04-01

    Goldfish preovulatory ovarian follicles (prior to germinal vesicle breakdown) were utilized for studies investigating the actions of activators of different signal transduction pathways on prostaglandin (PG) production. The protein kinase C (PKC) activators phorbol 12-myristate 13-acetate (PMA; 100-400 nM), 1-oleoyl-2-acetylglycerol (5 and 25 micrograms/ml), and 1,2-dioctanoylglycerol (10 and 50 micrograms/ml) stimulated PGE production; the inactive phorbol 4 alpha-phorbol didecanoate, which does not activate PKC, had no effect. Calcium ionophore A23187 (0.25-4.0 microM) stimulated PGE production and acted in a synergistic manner with activators of PKC. Although produced in lower amounts than PGE, PGF was stimulated by PMA and A23187. The direct activator of phospholipase A2, melittin (0.1-1.0 microM), stimulated a dose-related increase in PGE production, whereas chloroquine (100 microM), a putative inhibitor of phospholipase A2, blocked basal and PMA + A23187-stimulated PGE production. Several drugs known to elevate intracellular levels of cAMP including the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.1-1.0 mM), forskolin (10 microM), and dibutyryl cAMP (dbcAMP; 5 mM) attenuate PMA + A23187-stimulated PGE production. Melittin-stimulated production of PGE was inhibited by dbcAMP, suggesting that the action of cAMP was distal to the activation of phospholipase A2. In summary, these studies demonstrate that activation of PKC and elevation of intracellular calcium levels stimulate PG production, in part, through activation of phospholipase A2. The adenylate cyclase/cAMP signalling pathway is inhibitory to PG production by goldfish ovarian follicles. PMID:1315582

  16. Conceptus-derived prostaglandins regulate endometrial function in sheep.

    PubMed

    Dorniak, Piotr; Bazer, Fuller W; Wu, Guoyao; Spencer, Thomas E

    2012-07-01

    In sheep, the trophectoderm of the elongating conceptus secretes interferon tau (IFNT) and prostaglandins (PGE2, PGF2alpha, PGI2). The PGs are derived from PG synthase 2 (PTGS2), and inhibition of PTGS2 in utero prevents conceptus elongation. IFNT increases expression of many genes in the endometrial epithelia that regulate conceptus elongation. This study tested the hypothesis that PGs secreted by the conceptus regulate endometrial functions that govern conceptus elongation. Cyclic ewes received intrauterine infusions of control vehicle or early pregnancy levels of IFNT, PGE2, PGF2alpha, or PGI2 from Days 10-14 postestrus. Expression levels of endometrial GRP, IGFBP1, and LGALS15, whose products stimulate trophectoderm cell migration and attachment, were increased by PGE2, PGI2, and IFNT. All PGs and IFNT increased expression of the HEXB protease gene, but only IFNT increased the CST6 protease inhibitor gene. Differential effects of PGs were observed for expression of the CTSL protease gene and its inhibitor, CST3. IFNT, PGF2alpha, and PGI2 increased ANGPTL3 expression, but only IFNT and PGE2 increased HIF1A expression, both of which regulate angiogenesis. For glucose transporters, IFNT and all PGs increased SLC2A1 expression, but only PGs increased SLC2A5 expression, whereas endometrial SLC2A12 and SLC5A1 expression levels were increased by IFNT, PGE2, and PGF2alpha. Infusions of all PGs and IFNT increased the amino acid transporter SLC1A5, but only IFNT increased SLC7A2 expression. In the uterine lumen, only IFNT increased glucose levels, and only PGE2 and PGF2alpha increased total amino acids. These results indicate that PGs and IFNT from the conceptus coordinately regulate endometrial functions important for growth and development of the conceptus during the peri-implantation period of pregnancy. PMID:22517622

  17. BVDV alters uterine prostaglandin production during pregnancy recognition in cows.

    PubMed

    Cheng, Zhangrui; Abudureyimu, Ayimuguli; Oguejiofor, Chike F; Ellis, Rebekah; Barry, Amy Teresa; Chen, Xing; Anstaett, Olivia L; Brownlie, Joe; Wathes, D Claire

    2016-06-01

    Embryonic mortality in cows is at least in part caused by failure of pregnancy recognition (PR). Evidence has shown that bovine viral diarrhoea virus (BVDV) infection can disrupt pregnancy. Prostaglandins (PG) play important roles in many reproductive processes, such as implantation. The aim of this study was to investigate the effect of BVDV infection on uterine PG production and PR using an in vitro PR model. Bovine uterine endometrial cells isolated from ten BVDV-free cows were cultured and treated with 0 or 100ng/mL interferon-τ (IFNT) in the absence or presence of non-cytopathic BVDV (ncpBVDV). PGF2α and PGE2 concentrations in the spent medium were measured using radioimmunoassays, and in the treated cells expression of the genes associated with PG production and signalling was quantified using qPCR. The results showed that the IFNT challenge significantly stimulated PTGS1 and PTGER3 mRNA expression and PGE2 production; however, these stimulatory effects were neutralised in the presence of ncpBVDV infection. ncpBVDV infection significantly increased PTGS1 and mPGES1 mRNA expression and decreased AKR1B1 expression, leading to increased PGE2 and decreased PGF2α concentrations and an increased PGE2:PGF2α ratio. The other tested genes, including PGR, ESR1, OXTR, PTGS2, PTGER2 and PTGFR, were not significantly altered by IFNT, ncpBVDV or their combination. Our study suggests that BVDV infection may impair PR by (1) inhibiting the effect of IFNT on uterine PG production and (2) inducing an endocrine switch of PG production from PGF2α to PGE2 to decrease uterine immunity, thereby predisposing the animals to uterine disease. PMID:26952097

  18. Reversal of Myofibroblast Differentiation by Prostaglandin E2

    PubMed Central

    Garrison, Garth; Huang, Steven K.; Okunishi, Katsuhide; Scott, Jacob P.; Kumar Penke, Loka Raghu; Scruggs, Anne M.

    2013-01-01

    Differentiation of fibroblasts into α-smooth muscle actin (SMA)–expressing myofibroblasts represents a critical step in the pathogenesis of fibrotic disorders, and is generally regarded as irreversible. Prostaglandin E2 (PGE2) has been shown to prevent multiple aspects of fibroblast activation, including the differentiation of fibroblasts to myofibroblasts. Here, we investigated its ability to reverse this differentiated phenotype. Fetal and adult lung fibroblasts were induced to differentiate into myofibroblasts by 24-hour culture with transforming growth factor (TGF)-β1 or endothelin-1. Cells were then treated without or with PGE2 for various intervals and assessed for α-SMA expression. In the absence of PGE2 treatment, α-SMA expression induced by TGF-β1 was persistent and stable for up to 8 days. By contrast, PGE2 treatment effected a dose-dependent decrease in α-SMA and collagen I expression that was observed 2 days after PGE2 addition, peaked at 3 days, and persisted through 8 days in culture. This effect was not explained by an increase in myofibroblast apoptosis, and indeed, reintroduction of TGF-β1 2 days after addition of PGE2 prompted dedifferentiated fibroblasts to re-express α-SMA, indicating redifferentiation to myofibroblasts. This effect of PGE2 was associated with inhibition of focal adhesion kinase signaling, and a focal adhesion kinase inhibitor was also capable of reversing myofibroblast phenotype. These data unambiguously demonstrate reversal of established myofibroblast differentiation. Because many patients have established or even advanced fibrosis by the time they seek medical attention, this capacity of PGE2 has the potential to be harnessed for therapy of late-stage fibrotic disorders. PMID:23470625

  19. Molecular basis of maple syrup urine disease: Novel mutations at the E1[alpha] locus that impair E1([alpha][sub 2][beta][sub 2]) assembly or decrease steady-state E1[alpha] mRNA levels of branched-chain [alpha]-keto acid dehydrogenase complex

    SciTech Connect

    Chuang, J.L.; Fisher, C.R.; Chuang, D.T.; Cox, R.P. )

    1994-08-01

    The authors report the occurrence of three novel mutations in the E1[alpha] (BCKDHA) locus of the branched-chain [alpha]-keto acid dehydrogenase (BCKAD) complex that cause maple syrup urine disease (MSUD). An 8-bp deletion in exon 7 is present in one allele of a compound-heterozygous patient (GM-649). A single C nucleotide insertion in exon 2 occurs in one allele of an intermediate-MSUD patient (Lo). The second allele of patient Lo carries an A-to-G transition in exon 9 of the E1[alpha] gene. This missense mutation changes Tyr-368 to Cys (Y368C) in the E1[alpha] subunit. Both the 8-bp deletion and the single C insertion generate a downstream nonsense codon. Both mutations appear to be associated with a low abundance of the mutant E1[alpha] mRNA, as determined by allele-specific oligonucleotide probing. Transfection studies strongly suggest that the Y368C substitution in the E1[alpha] subunit impairs its proper assembly with the normal E1[beta]. Unassembled as well as misassembled E1[alpha] and E1[beta] subunits are degraded in the cell. 32 refs., 8 figs.

  20. Integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} effectors p130Cas, Src and talin regulate carcinoma invasion and chemoresistance

    SciTech Connect

    Sansing, Hope A.; Sarkeshik, Ali; Yates, John R.; Patel, Vyomesh; Gutkind, J. Silvio; Yamada, Kenneth M.; Berrier, Allison L.

    2011-03-11

    Research highlights: {yields} Proteomics of clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta}, {alpha}{sub 6}{beta} receptors in oral carcinoma. {yields} p130Cas, Dek, Src and talin regulate oral carcinoma invasion. {yields} p130Cas, talin, Src and zyxin regulate oral carcinoma resistance to cisplatin. -- Abstract: Ligand engagement by integrins induces receptor clustering and formation of complexes at the integrin cytoplasmic face that controls cell signaling and cytoskeletal dynamics critical for adhesion-dependent processes. This study searches for a subset of integrin effectors that coordinates both tumor cell invasion and resistance to the chemotherapeutic drug cisplatin in oral carcinomas. Candidate integrin effectors were identified in a proteomics screen of proteins recruited to clustered integrin {alpha}{beta}1, {alpha}{sub v}{beta} or {alpha}{sub 6}{beta} receptors in oral carcinomas. Proteins with diverse functions including microtubule and actin binding proteins, and factors involved in trafficking, transcription and translation were identified in oral carcinoma integrin complexes. Knockdown of effectors in the oral carcinoma HN12 cells revealed that p130Cas, Dek, Src and talin were required for invasion through Matrigel. Disruption of talin or p130Cas by RNA interference increased resistance to cisplatin, whereas targeting Dek, Src or zyxin reduced HN12 resistance to cisplatin. Analysis of the spreading of HN12 cells on collagen I and laminin I revealed that a decrease in p130Cas or talin expression inhibited spreading on both matrices. Interestingly, a reduction in zyxin expression enhanced spreading on laminin I and inhibited spreading on collagen I. Reduction of Dek, Src, talin or zyxin expression reduced HN12 proliferation by 30%. Proliferation was not affected by a reduction in p130Cas expression. We conclude that p130Cas, Src and talin function in both oral carcinoma invasion and resistance to cisplatin.

  1. An investigation of the toxicity of 1alpha-hydroxycholecalciferol to calves.

    PubMed

    Mullen, P A; Bedford, P G; Ingram, P L

    1979-11-01

    Two calves were treated with 15 micrograms/kg body weight of 1alpha-hydroxycholecalciferol by intramuscular injection on four occasions at seven-day intervals. Anorexia and reduced water consumption persisted for 48 h after each treatment. No clinical signs of iridocyclitis or any other lesions of the eyes were present at any time either macroscopically or microscopically. After the first treatment serum GOT and GD activities increased, serum AP activity fell, serum concentrations of calcium and inorganic phosphate increased, and magnesium concentrations decreased. The reduced serum magnesium concentrations and increased calcium and inorganic phosphate concentrations were maintained for the duration of the experiment, but there was no evidence of a cumulative effect of successive treatments. Blood urea concentrations increased after the third treatment. The gross pathology at post mortem examination was similar to that reported after vitamin D3 supplementation. PMID:542713

  2. Impotence evaluated by the use of prostaglandin E1

    SciTech Connect

    Hwang, T.I.; Yang, C.R.; Wang, S.J.; Chang, C.L.; Tzai, T.S.; Chang, C.H.; Wu, H.C.

    1989-06-01

    We screened 80 patients at our hospital for the differential diagnosis of impotence using intracavernous injection of prostaglandin E1 (20 micrograms). The rate of positive response was 78.8 per cent (63 patients). Neither systemic reactions nor priapism occurred. However, a considerable incidence (23.8 per cent, 19 of 80 patients) of tolerable injection pain was encountered. The 133-xenon penile washout study was conducted routinely in impotent men for hemodynamic evaluation of penile vascularity. In 80 patients a positive correlation between the response of intracavernous prostaglandin E1 injection and the result of the washout study was found (r equals 0.381, p less than 0.0002). We selected 14 subjects randomly to receive additional intravenous infusions of prostaglandin E1 (6 ampules, 120 micrograms total) for 3 days, after which another 133-xenon washout study was done. The washout studies before and after intravenous prostaglandin E1 infusion were compared, and 10 patients (71.4 per cent) appeared to obtain improvement in half-time clearance and penile blood flow. However, only 3 patients noticed improvement subjectively. We suggest that prostaglandin E1 could be a desirable alternative for the diagnosis and treatment of impotence.

  3. Prostaglandins and Their Receptors in Insect Biology

    PubMed Central

    Stanley, David; Kim, Yonggyun

    2011-01-01

    We treat the biological significance of prostaglandins (PGs) and their known receptors in insect biology. PGs and related eicosanoids are oxygenated derivatives of arachidonic acid (AA) and two other C20 polyunsaturated fatty acids. PGs are mostly appreciated in the context of biomedicine, but a growing body of literature indicates the biological significance of these compounds extends throughout the animal kingdom, and possibly beyond. The actions of most PGs are mediated by specific receptors. Biomedical research has discovered a great deal of knowledge about PG receptors in mammals, including their structures, pharmacology, molecular biology and cellular locations. Studies of PG receptors in insects lag behind the biomedical background, however, recent results hold the promise of accelerated research in this area. A PG receptor has been identified in a class of lepidopteran hemocytes and experimentally linked to the release of prophenoloxidase. PGs act in several crucial areas of insect biology. In reproduction, a specific PG, PGE2, releases oviposition behavior in most crickets and a few other insect species; PGs also mediate events in egg development in some species, which may represent all insects. PGs play major roles in modulating fluid secretion in Malpighian tubules, rectum and salivary glands, although, again, this has been studied in only a few insect species that may represent the Class. Insect immunity is a very complex defense system. PGs and other eicosanoids mediate a large number of immune reactions to infection and invasion. We conclude that research into PGs and their receptors in insects will lead to important advances in our understanding of insect biology. PMID:22654840

  4. Pro-gliogenic effect of IL-1alpha in the differentiation of embryonic neural precursor cells in vitro.

    PubMed

    Ajmone-Cat, Maria Antonietta; Cacci, Emanuele; Ragazzoni, Ylenia; Minghetti, Luisa; Biagioni, Stefano

    2010-05-01

    Inflammation is regarded as a main obstacle to brain regeneration. Major detrimental effects are attributed to microglial/macrophagic products, such as TNF-alpha and interleukin (IL)-6. The role of cytokines of the IL-1 family, particularly of IL-1alpha, in the modulation of neural precursor cell (NPC) properties is less characterized. IL-1alpha is one of the most abundant cytokines released upon acute stimulation of microglia with lipopolysaccharide and is down-regulated upon chronic stimulation. As we recently demonstrated, acutely activated microglia reduces NPC survival, prevent neuronal differentiation and promote glial differentiation. Chronically activated microglia are instead permissive to NPC survival and neuronal differentiation, and less effective in promoting astrocytic differentiation. We thus investigated whether IL-1alpha could contribute to the effects of acutely activated microglia on NPC. We found that NPC express functional IL-1 receptors and that exposure to recombinant IL-1alpha strongly enhances NPC differentiation into astrocytes, without affecting cell viability and neuronal differentiation. In the same conditions, recombinant IL-1beta has pro-gliogenic effects at concentrations 10-fold higher than those found in activated microglial conditioned media. Interestingly, immunodepletion of IL-1alpha in activated microglial conditioned media fails to revert microglial pro-gliogenic action and slightly enhances neuronal differentiation, revealing that other microglial-derived factors contribute to the modulation of NPC properties. PMID:20236219

  5. Fasting induces basolateral uptake transporters of the SLC family in the liver via HNF4alpha and PGC1alpha.

    PubMed

    Dietrich, Christoph G; Martin, Ina V; Porn, Anne C; Voigt, Sebastian; Gartung, Carsten; Trautwein, Christian; Geier, Andreas

    2007-09-01

    Fasting induces numerous adaptive changes in metabolism by several central signaling pathways, the most important represented by the HNF4alpha/PGC-1alpha-pathway. Because HNF4alpha has been identified as central regulator of basolateral bile acid transporters and a previous study reports increased basolateral bile acid uptake into the liver during fasting, we hypothesized that HNF4alpha is involved in fasting-induced bile acid uptake via upregulation of basolateral bile acid transporters. In rats, mRNA of Ntcp, Oatp1, and Oatp2 were significantly increased after 48 h of fasting. Protein expression as determined by Western blot showed significant increases for all three transporters 72 h after the onset of fasting. Whereas binding activity of HNF1alpha in electrophoretic mobility shift assays remained unchanged, HNF4alpha binding activity to the Ntcp promoter was increased significantly. In line with this result, we found significantly increased mRNA expression of HNF4alpha and PGC-1alpha. Functional studies in HepG2 cells revealed an increased endogenous NTCP mRNA expression upon cotransfection with either HNF4alpha, PGC-1alpha, or a combination of both. We conclude that upregulation of the basolateral bile acid transporters Ntcp, Oatp1, and Oatp2 in fasted rats is mediated via the HNF4alpha/PGC-1alpha pathway. PMID:17640976

  6. Defects in energy homeostasis in Leigh syndrome French Canadian variant through PGC-1alpha/LRP130 complex.

    PubMed

    Cooper, Marcus P; Qu, Lishu; Rohas, Lindsay M; Lin, Jiandie; Yang, Wenli; Erdjument-Bromage, Hediye; Tempst, Paul; Spiegelman, Bruce M

    2006-11-01

    Leigh syndrome French Canadian variant (LSFC) is an autosomal recessive neurodegenerative disorder due to mutation in the LRP130 (leucine-rich protein 130 kDa) gene. Unlike classic Leigh syndrome, the French Canadian variant spares the heart, skeletal muscle, and kidneys, but severely affects the liver. The precise role of LRP130 in cytochrome c oxidase deficiency and hepatic lactic acidosis that accompanies this disorder is unknown. We show here that LRP130 is a component of the PGC-1alpha (peroxisome proliferator-activated receptor coactivator 1-alpha) transcriptional coactivator holocomplex and regulates expression of PEPCK (phosphoenolpyruvate carboxykinase), G6P (glucose-6-phosphatase), and certain mitochondrial genes through PGC-1alpha. Reduction of LRP130 in fasted mice via adenoviral RNA interference (RNAi) vector blocks the induction of PEPCK and G6P, and blunts hepatic glucose output. LRP130 is also necessary for PGC-1alpha-dependent transcription of several mitochondrial genes in vivo. These data link LRP130 and PGC-1alpha to defective hepatic energy homeostasis in LSFC, and reveal a novel regulatory mechanism of glucose homeostasis. PMID:17050673

  7. In vitro biological activities of a series of 2 beta-substituted analogues of 1 alpha,25-dihydroxyvitamin D3.

    PubMed

    Tsugawa, N; Nakagawa, K; Kurobe, M; Ono, Y; Kubodera, N; Ozono, K; Okano, T

    2000-01-01

    Biological activities of a series of 2beta-substituted analogues of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] were evaluated in vitro in terms of their binding affinity with regard to calf thymus cytosolic vitamin D receptor (VDR) and rat plasma vitamin D-binding protein (DBP). Additionally, reporter gene luciferase activities using either a rat 25-hydroxyvitamin D3-24-hydroxylase gene promoter, including two vitamin D-responsive elements (VDREs), in transfected rat osteoblast-like ROS17/2.8 cells, or a human VDR-GAL4 modified two-hybrid system in transfected human epitheloid carcinoma, cervix HeLa cells were examined. Binding affinity for VDR, transactivation potency on the target gene and VDR-mediated gene regulation of the hydroxyalkyl and hydroxyalkoxy 2beta-substituted analogues were almost comparable to those of 1alpha,25(OH)2D3, while the alkyl and alkenyl analogues were much less active than 1alpha,25(OH)2D3. This study investigated the biological evaluation of a series of 2beta-substituted analogues at the molecular level, with regard to the structural differences of alkyl, alkenyl, hydroxyalkyl, hydroxyalkoxy, alkoxy, hydroxy and chloro substituents at the 2beta-position of 1alpha,25(OH)2D3. PMID:10706413

  8. Intravenous human interleukin-1alpha impairs memory processing in mice: dependence on blood-brain barrier transport into posterior division of the septum.

    PubMed

    Banks, W A; Farr, S A; La Scola, M E; Morley, J E

    2001-11-01

    Peripherally administered cytokines profoundly affect the central nervous system (CNS). One mechanism by which they could affect the CNS is by crossing the blood-brain barrier (BBB) to interact directly with brain receptors. Human and murine IL-1alpha (hIL-1alpha; mIL-1alpha) are transported across the murine BBB with a high rate of transport into the posterior division of the septum (PDS), but it is unknown whether BBB transport is relevant to their actions. Here, we injected species-specific blocking antibodies into the PDS to determine whether transport across the BBB is required for blood-borne hIL-1alpha to affect memory. Retention was impaired in a dose-dependent manner when hIL-1alpha was injected either by tail vein (i.v.) or into the PDS, with the PDS route being 1000 times more potent. About 70% of the memory impairment induced by i.v. hIL-1alpha was reversed by injecting a blocking antibody (Ab) specific for hIL-1alpha into the PDS. This shows that much of the memory impairment induced by hIL-1alpha depends on its ability to cross the BBB. Ab specific for mIL-1alpha was also effective in reversing memory impairment, showing that hIL-1alpha releases mIL-1alpha from endogenous stores. Whether the mIL-1alpha was released from peripheral stores, which would require it to cross the BBB, or from brain stores is unknown. In conclusion, these results show that exogenous, blood-borne hIL-1alpha affects memory by releasing mIL-1alpha from endogenous stores and by crossing the BBB to act at sites within the PDS. PMID:11602664

  9. Prostaglandin E2-induced colonic secretion in patients with and without colorectal neoplasia

    PubMed Central

    2010-01-01

    Background The pathogenesis for colorectal cancer remains unresolved. A growing body of evidence suggests a direct correlation between cyclooxygenase enzyme expression, prostaglandin E2 metabolism and neoplastic development. Thus further understanding of the regulation of epithelial functions by prostaglandin E2 is needed. We hypothesized that patients with colonic neoplasia have altered colonic epithelial ion transport and express functionally different prostanoid receptor levels in this respect. Methods Patients referred for colonoscopy were included and grouped into patients with and without colorectal neoplasia. Patients without endoscopic findings of neoplasia served as controls. Biopsy specimens were obtained from normally appearing mucosa in the sigmoid part of colon. Biopsies were mounted in miniaturized modified Ussing air-suction chambers. Indomethacin (10 μM), various stimulators and inhibitors of prostanoid receptors and ion transport were subsequently added to the chamber solutions. Electrogenic ion transport parameters (short circuit current and slope conductance) were recorded. Tissue pathology and tissue damage before and after experiments was assessed by histology. Results Baseline short circuit current and slope conductance did not differ between the two groups. Patients with neoplasia were significantly more sensitive to indomethacin with a decrease in short circuit current of 15.1 ± 2.6 μA·cm-2 compared to controls, who showed a decrease of 10.5 ± 2.1 μA·cm-2 (p = 0.027). Stimulation or inhibition with theophylline, ouabain, bumetanide, forskolin or the EP receptor agonists prostaglandin E2, butaprost, sulprostone and prostaglandin E1 (OH) did not differ significantly between the two groups. Histology was with normal findings in both groups. Conclusions Epithelial electrogenic transport is more sensitive to indomethacin in normal colonic mucosa from patients with previous or present colorectal neoplasia compared to colonic mucosa from

  10. Intracrine prostaglandin E(2) signalling regulates hypoxia-inducible factor-1α expression through retinoic acid receptor-β.

    PubMed

    Fernández-Martínez, Ana B; Jiménez, María I Arenas; Manzano, Victoria Moreno; Lucio-Cazaña, Francisco J

    2012-12-01

    We have previously found in human renal proximal tubular HK-2 cells that hypoxia- and all-trans retinoic acid-induced hypoxia-inducible factor-1α up-regulation is accompanied by retinoic acid receptor-β up-regulation. Here we first investigated whether hypoxia-inducible factor-1α expression is dependent on retinoic acid receptor-β and our results confirmed it since (i) hypoxia-inducible factor-1α-inducing agents hypoxia, hypoxia-mimetic agent desferrioxamine, all-trans retinoic acid and interleukin-1β increased retinoic acid receptor-β expression, (ii) hypoxia-inducible factor-1α up-regulation was prevented by retinoic acid receptor-β antagonist LE-135 or siRNA retinoic acid receptor-β and (iii) there was direct binding of retinoic acid receptor-β to the retinoic acid response element in hypoxia-inducible factor-1α promoter upon treatment with all-trans retinoic acid and 16,16-dimethyl-prostaglandin E(2). Since intracellular prostaglandin E(2) mediates hypoxia-inducible factor-1α up-regulation in normoxia in HK-2 cells, we next investigated and confirmed, its role in the up-regulation of retinoic acid receptor-β in normoxia by hypoxia-inducible factor-1α-inducing agents all-trans retinoic acid, interleukin-1β and 16,16-dimethyl-prostaglandin E(2) by inhibiting cyclooxygenases, prostaglandin influx transporter or EP receptors. Interestingly, the hypoxia-induced increase in retinoic acid receptor-β expression and accumulation of hypoxia-inducible factor-1α was also blocked by the inhibitors tested. This is the first time, to our knowledge, that retinoic acid receptor-β signalling is involved in the control of the expression of transcription factor hypoxia-inducible factor-1α in both normoxia and hypoxia and that retinoic acid receptor-β expression is found to be strictly regulated by intracellular prostaglandin E(2). Given the relevance of hypoxia-inducible factor-1α in the kidney in terms of tumorigenesis, progressive renal failure, production

  11. The oral activity of delta'-tetrahydrocannabinol and its dependence on prostaglandin E2.

    PubMed Central

    Fairbairn, J. W.; Pickens, J. T.

    1979-01-01

    1 delta'-trans-Tetrahydrocannabinol (THC) is more active orally in mice than previously thought, as cataleptic responses occur at doses from 0.06 mg/kg upwards, with peak activity at 2 to 4 h after dosing. These doses and peaks correspond well with the effects in man. 2 Comparison with chlorpromazine in mice shows that chlorpromazine and THC are equipotent as cataleptics during the first 2 h after dosing; thereafter the THC activity increases to a peak when it is 5.67 times as active as chlorpromazine. 3 The cataleptic effect of THC is abolished by aspirin, indomethacine, diffunisal and phenylbutazone which inhibit the biosynthesis of prostaglandins and is restored by exogenous prostaglandin E2 (PGE2) but not PGE1 and PGF2 alpha. This suggests that the effect of THC depends upon the presence of PGE2. 4 In contrast, the cataleptic effect of chlorpromazine is not affected by pretreatment with aspirin. 5 THC is very much less active intraperitoneally than orally; our results suggest this is not due to poor absorption or extraction into fat depots. 6 Cannabidiol has no cataleptic effect. PMID:574040

  12. A Novel Selective Prostaglandin E2 Synthesis Inhibitor Relieves Pyrexia and Chronic Inflammation in Rats.

    PubMed

    Sugita, Ryusuke; Kuwabara, Harumi; Sugimoto, Kotaro; Kubota, Kazufumi; Imamura, Yuichiro; Kiho, Toshihiro; Tengeiji, Atsushi; Kawakami, Katsuhiro; Shimada, Kohei

    2016-04-01

    Prostaglandin E2 (PGE2) is a terminal prostaglandin in the cyclooxygenase (COX) pathway. Inhibition of PGE2 production may relieve inflammatory symptoms such as fever, arthritis, and inflammatory pain. We report here the profile of a novel selective PGE2 synthesis inhibitor, compound A [N-[(1S,3S)-3-carbamoylcyclohexyl]-1-(6-methyl-3-phenylquinolin-2-yl)piperidine-4-carboxamide], in animal models of pyrexia and inflammation. The compound selectively suppressed the synthesis of PGE2 in human alveolar adenocarcinoma cell line A549 cells and rat macrophages. In the lipopolysaccharide-induced pyrexia model, this compound selectively reduced PGE2 production in cerebrospinal fluid and showed an anti-pyretic effect. In the adjuvant-induced arthritis model, compound A therapeutically decreased foot swelling in the established arthritis. Our data demonstrates that selective suppression of PGE2 synthesis shows anti-pyretic and anti-inflammatory effects, suggesting that selective PGE2 synthesis inhibitors can be applied as an alternative treatment to nonsteroidal, anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors. PMID:26923147

  13. Chromosomal organization of the inducible and constitutive prostaglandin synthase/cyclooxygenase genes in mouse

    SciTech Connect

    Ping Zi Wen; Warden C.; Fletcher, B.S.; Kujubu, D.A.; Herschman, H.R.; Lusis, A.J. )

    1993-02-01

    Two distinct prostaglandin synthase/cyclooxygenase (PGS/COS) enzymes have recently been recognized. One (EC 1.14.00.1) is largely constitutive and has been characterized in a variety of species, whereas the other (also known as TIS10) is inducible by mitogens and inhibitable by glucocorticoids. Along with activation of phospholipase A2, the latter PGS/COS is likely to mediate ligand-induced prostaglandin production in a variety of cell types. The two enzymes have similar gene structures and activities. There is accumulating evidence that PGS/COX activity may play a role in inflammatory diseases. For example, PGS/COX expression is upregulated in inflammatory joint diseases and is genetically controlled. As part of an effort to examine genetic factors regulating PGS/COX expression and the possible involvement of the enzymes in mouse models of inflammatory disorders, we report here the chromosomal mapping of the genes for the constitutive and regulated PGS/COX enzymes. We will refer to the constitutive enzyme as Pgs-1 and the inducible enzyme as Pgs-2. 14 refs., 1 tab.

  14. Cysteamine and prostaglandin F2 beta stimulate rat gastric mucin release

    SciTech Connect

    Lamont, J.T.; Ventola, A.S.; Maull, E.A.; Szabo, S.

    1983-02-01

    Gastric mucin glycoproteins form an adherent gel over the surface epithelium that is thought to protect the stomach against chemical and physical damage. The purpose of this study was to measure the release of mucin glycoproteins from rat stomach after treatment with cysteamine and prostaglandin F2 beta, two structurally unrelated drugs that have been shown to protect the stomach against the noxious effects of alcohol and other damaging agents. Gastric mucin was separated into soluble (washout) and insoluble (adherent) phases before colorimetric quantitation of total mucin, protein-bound hexose, and sialic acid. Cysteamine produced a dose-dependent increase in release of soluble and gel mucin. Prostaglandin F2 beta caused a dose-dependent release of hexose-containing mucin but had no effect on sialic acid-containing glycoproteins. Sepharose 4B chromatography of both the soluble and adherent mucus revealed that greater than 90% was a high molecular weight glycoprotein fraction. N-Ethylmaleimide, a known inhibitor of cytoprotection by cysteamine, had no effect on mucin secretion. Similarly, indomethacin inhibited mucin secretion by cysteamine but did not significantly influence cytoprotection. Thus the secretion of mucin by cytoprotective agents is unlikely by itself to explain the ability of the stomach to resist chemical or physical damage.

  15. Modulation of ligand-mediated human red cell agglutinability by prostaglandins

    SciTech Connect

    McLawhon, R.W.; Marikovsky, Y.; Weinstein, R.S.

    1986-03-01

    Ethanol induces the transformation of human red cells from bioconcave discs to echinocytes in vitro. In addition, they have observed that ethanol can enhance the agglutination of red cells by the plant lectin wheat germ agglutinin or poly-L-lysine. Incubation of washed human red cells with 5 and 10% ethanol (v/v) in phosphate buffered saline, pH 7.3 at 25/sup 0/C produced a 30% increase in ligand-mediated agglutinability within 12 min. Simultaneous addition of ethanol and one of the following prostaglandin derivatives, PGE/sub 1/, pge/sub 2/, pgf/sub 2/-alpha, or PGl/sub 2/ (10/sup -9/ to 5 x 10/sup -7/ M) prevented the shape-associated increases in red cell agglutinability. Thromboxane-B/sub 2/ had no effect on agglutinability. Prostaglandins did not prevent ethanol-induced red cell shape transformations per se under identical experimental conditions. As intragastric administration of 100% ethanol results in the formation of spiculated red cell thrombi in postcapillary venules of rat gastric mucosa, they postulate that the cytoprotective role of prostanoids in preventing mucosal ulceration may be due in part to their capacity to inhibit intravascular ligand mediated red cell agglutination, hemostasis, and their sequelae, epithelial necrosis. Moreover, the data suggest that ethanol-induced red cell shape transformations and ligand-mediated agglutination represent two distinct and independent biological phenomena.

  16. Pyometra in Bitches Induces Elevated Plasma Endotoxin and Prostaglandin F2α Metabolite Levels

    PubMed Central

    Hagman, R; Kindahl, H; Lagerstedt, A-S

    2006-01-01

    Endotoxemia in bitches with pyometra can cause severe systemic effects directly or via the release of inflammatory mediators. Plasma endotoxin concentrations were measured in ten bitches suffering from pyometra with moderately to severely deteriorated general condition, and in nine bitches admitted to surgery for non-infectious reasons. Endotoxin samples were taken on five occasions before, during and after surgery. In addition, urine and uterine bacteriology was performed and hematological, blood biochemical parameters, prostaglandin F2α metabolite 15-ketodihydro-PGF2α (PG-metabolite), progesterone and oestradiol (E2-17β) levels were analysed. The results confirm significantly increased plasma levels of endotoxin in bitches with pyometra and support previous reports of endotoxin involvement in the pathogenesis of the disease. Plasma concentrations of PG-metabolite were elevated in pyometra bitches and provide a good indicator of endotoxin release since the concentrations were significantly correlated to the endotoxin levels and many other hematological and chemistry parameters. The γ-globulin serum protein electrophoresis fraction and analysis of PG-metabolite can be valuable in the diagnosis of endotoxin involvement if a reliable, rapid and cost-effective test for PG-metabolite analysis becomes readily available in the future. Treatment inhibiting prostaglandin biosynthesis and related compounds could be beneficial for bitches suffering from pyometra. PMID:16722306

  17. Expression of prostaglandin E synthases in the bovine oviduct.

    PubMed

    Gauvreau, D; Moisan, V; Roy, M; Fortier, M A; Bilodeau, J-F

    2010-01-01

    The oviduct is a specialized organ responsible for the storage and the transport of male and female gametes. It also provides an optimal environment for final gamete maturation, fertilization, and early embryo development. Prostaglandin (PG) E(2) is involved in many female reproductive functions, including ovulation, fertilization, implantation, and parturition. However, the control of its synthesis in the oviduct is not fully understood. Cyclooxygenases (COXs) are involved in the first step of the transformation of arachidonic acid to PGH(2.) The prostaglandin E synthases (PGESs) constitute a family of enzymes that catalyze the conversion of PGH(2) to PGE(2), the terminal step in the formation of this bioactive prostaglandin. Quantitative real-time PCR was used to determine the expression of COX-1, COX-2, microsomal prostaglandin E synthase-1 (mPGES-1), microsomal prostaglandin E synthase-2 (mPGES-2), and cytosolic prostaglandin E synthase (cPGES) mRNA in various sections of the oviduct, both ipsilateral and contralateral (to the ovary on which ovulation occurred) at various stages of the estrous cycle. Furthermore, protein expression and localization of cPGES, mPGES-1, and mPGES-2 were determined by Western blot and immunohistochemistry. All three PGESs were detected at both mRNA and protein levels in the oviduct. These PGESs were mostly concentrated in the oviductal epithelial layer and primarily expressed in the ampulla section of the oviduct and to a lesser extent in the isthmus and the isthmic-ampullary junction. The mPGES-1 protein was highly expressed in the contralateral oviduct, which contrasted with mPGES-2 mostly expressed in the ipsilateral oviduct. This is apparently the first report documenting that the three PGESs involved in PGE(2) production were present in the Bos taurus oviduct. PMID:19875162

  18. Prostaglandins, H2-receptor antagonists and peptic ulcer disease.

    PubMed

    Bright-Asare, P; Habte, T; Yirgou, B; Benjamin, J

    1988-01-01

    Peptic ulcer develops when offensive factors overwhelm defensive processes in the gastroduodenal mucosa. Offensive factors include NSAIDs, hydrochloric acid-peptic activity, bile reflux, and some products of the lipoxygenase pathway such as leukotriene B4; whereas defensive processes are largely mediated by prostaglandins through poorly understood mechanisms uniformly termed cytoprotection. Cytoprotection, a physiological process working through the products of arachidonic acid metabolism, may result from the net effect of the protective actions of prostaglandins versus the damaging actions of leukotrienes. Some prostaglandins also have antisecretory effects. Therefore the peptic ulcer healing effects of prostaglandin analogues, all of which have significant antisecretory activity, may be more due to their antisecretory effects than primarily to their effects on mucosal defences. Certain drug-induced gastroduodenal lesions, e.g. NSAID-induced ulcers, which are often unresponsive to H2-receptor antagonists, have been healed and their recurrence prevented by the use of PGE1 and PGE2 analogues. All the prostaglandin analogues investigated to date in humans have the potential for inducing abortion, an important side effect which may limit their worldwide use. The optimal prostaglandin analogue for ulcer healing should not induce abortion and should be potently cytoprotective. The predominant damaging agent in the development of peptic ulcer disease is gastric hydrochloric acid. Thus, the worldwide established efficacy and safety of H2-receptor antagonists such as cimetidine, ranitidine, famotidine and most recently of roxatidine acetate suggest that these agents have become the standard by which other forms of anti-ulcer therapy should be judged. PMID:2905237

  19. Protein disulfide isomerase as a novel target for cyclopentenone prostaglandins: implications for hypoxic ischemic injury

    PubMed Central

    Liu, Hao; Chen, Jie; Li, Wenjin; Rose, Marie E.; Shinde, Sunita N.; Balasubramani, Manimalha; Uechi, Guy T.; Mutus, Bülent; Graham, Steven H.; Hickey, Robert W.

    2016-01-01

    Cyclooxygenase-2 (COX-2) is an important contributor to ischemic brain injury. Identification of the downstream mediators of COX-2 toxicity may allow the development of targeted therapies. Of particular interest is the cyclopentenone family of prostaglandin metabolites. Cyclopentenone prostaglandins (CyPGs) are highly reactive molecules that form covalent bonds with cellular thiols. Protein disulfide isomerase (PDI) is an important molecule for the restoration of denatured proteins following ischemia. Because PDI has several thiols, including thiols within the active thioredoxin-like domain, we hypothesized that PDI is a target of CyPGs and that CyPG binding of PDI is detrimental. CyPG–PDI binding was detected in vitro via immunoprecipitation and MS. CyPG–PDI binding decreased PDI enzymatic activity in recombinant PDI treated with CyPG, and PDI immunoprecipitated from neuronal culture treated with CyPG or anoxia. Toxic effects of binding were demonstrated in experiments showing that: (a) pharmacologic inhibition of PDI increased cell death in anoxic neurons, (b) PDI overexpression protected neurons exposed to anoxia and SH-SY5Y cells exposed to CyPG, and (c) PDI overexpression in SH-SY5Y cells attenuated ubiquitination of proteins and decreased activation of pro-apoptotic caspases. In conclusion, CyPG production and subsequent binding of PDI is a novel and potentially important mechanism of ischemic brain injury. We show that CyPGs bind to PDI, cyclopentenones inhibit PDI activity, and CyPG–PDI binding is associated with increased neuronal susceptibility to anoxia. Additional studies are necessary to determine the relative role of CyPG-dependent inhibition of PDI activity in ischemia and other neurodegenerative disorders. PMID:25754985

  20. Suppression of Alzheimer-Associated Inflammation by Microglial Prostaglandin-E2 EP4 Receptor Signaling

    PubMed Central

    Woodling, Nathaniel S.; Wang, Qian; Priyam, Prachi G.; Larkin, Paul; Shi, Ju; Johansson, Jenny U.; Zagol-Ikapitte, Irene; Boutaud, Olivier

    2014-01-01

    A persistent and nonresolving inflammatory response to accumulating Aβ peptide species is a cardinal feature in the development of Alzheimer's disease (AD). In response to accumulating Aβ peptide species, microglia, the innate immune cells of the brain, generate a toxic inflammatory response that accelerates synaptic and neuronal injury. Many proinflammatory signaling pathways are linked to progression of neurodegeneration. However, endogenous anti-inflammatory pathways capable of suppressing Aβ-induced inflammation represent a relatively unexplored area. Here we report that signaling through the prostaglandin-E2 (PGE2) EP4 receptor potently suppresses microglial inflammatory responses to Aβ42 peptides. In cultured microglial cells, EP4 stimulation attenuated levels of Aβ42-induced inflammatory factors and potentiated phagocytosis of Aβ42. Microarray analysis demonstrated that EP4 stimulation broadly opposed Aβ42-driven gene expression changes in microglia, with enrichment for targets of IRF1, IRF7, and NF-κB transcription factors. In vivo, conditional deletion of microglial EP4 in APPSwe-PS1ΔE9 (APP-PS1) mice conversely increased inflammatory gene expression, oxidative protein modification, and Aβ deposition in brain at early stages of pathology, but not at later stages, suggesting an early anti-inflammatory function of microglial EP4 signaling in the APP-PS1 model. Finally, EP4 receptor levels decreased significantly in human cortex with progression from normal to AD states, suggesting that early loss of this beneficial signaling system in preclinical AD development may contribute to subsequent progression of pathology. PMID:24760848

  1. [Receptors involved in the mechanism of action of topical prostaglandines].

    PubMed

    Neacsu, Alina Mihaela

    2009-01-01

    Hypotensive effect to prostaglandins analogs (latanoprost, travoprost, tafluprost) means to increase uveoscleral outflow by action to FP receptors who generated extracellular matrix changes and intermuscular spaces changes. Syntetic prostamides analogs (bimatoprost) have a particulary action with a receptors most and intensive studied. The bimatoprost effect is the consequences to preferated stimulations on the specific receptors who have action only the tissue with prostaglandins activity is important to specify what the bimatoprost have dual effect: to uveoscleral outflow and classic outflow by increase hidraulic conductivity. PMID:19697832

  2. Prognostic Significance of Tumor Hypoxia Inducible Factor-1{alpha} Expression for Outcome After Radiotherapy in Oropharyngeal Cancer

    SciTech Connect

    Silva, Priyamal; Slevin, Nick J.; Sloan, Philip; Valentine, Helen; Cresswell, Jo; Ryder, David; Price, Patricia; Homer, Jarrod J.; West, Catharine

    2008-12-01

    Purpose: Head-and-neck squamous cell carcinoma (HNSCC) represents a heterogeneous group of patients in terms of subsite, treatment, and biology. Currently most management decisions are based on clinical parameters with little appreciation of patient differences in underlying tumor biology. We investigated the prognostic significance of clinicopathologic features and tumor hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) expression in a homogeneous series of patients who underwent radiotherapy. Methods and Materials: An audit identified 133 consecutive patients with histologically proven squamous cell carcinoma of the tonsil or tongue base. All patients received primary radiotherapy between 1996 and 2001. Tumor HIF-1{alpha} expression was examined in 79 patients. Results: Features associated with poor locoregional control were low Hb level (p = 0.05) and advancing T (p = 0.008), N (p = 0.03), and disease (p = 0.008) stage. HIF-1{alpha} expression was a more significant adverse prognostic factor in the tonsil (hazard ratio [HR], 23.1; 95% confidence interval [CI]. 3.04-176.7) than the tongue-base tumor (HR, 2.86; 95% CI, 1.14-7.19) group (p = 0.03, test for interaction). High tumor HIF-1{alpha} expression was associated with low blood Hb levels (p = 0.03). In a multivariate analysis HIF-1{alpha} expression retained prognostic significance for locoregional control (HR, 7.10; 95% CI, 3.07-16.43) and cancer-specific survival (HR, 9.19; 95% CI, 3.90-21.6). Conclusions: There are significant differences in radiation therapy outcome within a homogeneous subsite of the oropharynx related to molecular marker expression. The work highlights the importance of studying homogeneous groups of patients in HNSCC, and the complex interrelationships between tumor biology and clinicopathologic factors. The establishment of tumor-type specific markers would represent a major advance in this area.

  3. The Prostaglandin Transporter: Eicosanoid Reuptake, Control of Signaling, and Development of High-Affinity Inhibitors as Drug Candidates

    PubMed Central

    Schuster, Victor L.; Chi, Yuling; Lu, Run

    2015-01-01

    We discovered the prostaglandin transporter (PGT) and cloned the human cDNA and gene. PGT transports extracellular prostaglandins (PGs) into the cytoplasm for enzymatic inactivation. PGT knockout mice have elevated prostaglandin E2 (PGE2) and neonatal patent ductus arteriosus, which reflects PGT's control over PGE2 signaling at EP1/EP4 cell-surface receptors. Interestingly, rescued PGT knockout pups have a nearly normal phenotype, as do human PGT nulls. Given the benign phenotype of PGT genetic nulls, and because PGs are useful medicines, we have approached PGT as a drug target. Triazine library screening yielded a lead compound of inhibitory constant 50% (IC50) = 3.7 μM, which we developed into a better inhibitor of IC50 378 nM. Further structural improvements have yielded 26 rationally designed derivatives with IC50 < 100 nM. The therapeutic approach of increasing endogenous PGs by inhibiting PGT offers promise in diseases such as pulmonary hypertension and obesity. PMID:26330684

  4. Prostaglandin-targeting agents and spectral heart rate variability in experimental partial bladder outlet obstruction in rats.

    PubMed

    Dobrek, Ł; Baranowska, A; Skowron, B; Furgała, A; Żurowski, D; Thor, P

    2016-03-01

    The purpose of this study was to determine the activity of the autonomic nervous system (ANS), using spectral analysis of the heart rate variability (HRV) in the model of partial bladder outlet obstruction (PBOO) in rats treated with selected non-steroidal anti-inflammatory drugs (NSAID): piroxicam (PRX) or meloxicam (MLX), and following administration of PGF2a prostaglandin analogue (Enzaprost F5). Neither the use of PGF2a analogue nor of MLX, caused significant changes in the HRV spectrum (except for HRV spectrum total power reduction with MLX). The use of PRX caused reduction of the total power and powers of all components of the HRV spectrum (except for VLF). Moreover, increased nLF and reduced nHF were observed. The obtained results suggest that the total prostaglandin synthesis block with a non-selective cyclooxygenase inhibitor (PRX) results in reduced ANS total activity, with decreased parasympathetic activity and a relative sympathetic predominance. The preferential cyclooxygenase-2 block (MLX) caused reduction of the total ANS activity as well, however with no clear disproportion of any part of the ANS. Therefore, prostaglandin synthesis inhibition and associated decrease of parasympathetic activity may constitute an additional and favourable feature of NSAID pharmacodynamics in the treatment of BPH. PMID:27030625

  5. Protection against dexamethasone-induced muscle atrophy is related to modulation by testosterone of FOXO1 and PGC-1{alpha}

    SciTech Connect

    Qin, Weiping; Pan, Jiangping; Wu, Yong; Bauman, William A.; Cardozo, Christopher

    2010-12-17

    Research highlights: {yields} In rat gastrocnemius muscle, dexamethasone reduced PGC-1{alpha} cellular and nuclear levels without altering mRNA levels for this factor. {yields} Dexamethasone reduced phosphorylating of p38 MAPK, which stabilizes PGC-1{alpha} and promotes its nuclear entry. {yields} Co-administration of testosterone with dexamethasone increased cellular and nuclear levels of PGC-1{alpha} protein without changing its mRNA levels. {yields} Co-administration of testosterone restored p38 MAPK levels to those of controls. -- Abstract: Glucocorticoid-induced muscle atrophy results from muscle protein catabolism and reduced protein synthesis, associated with increased expression of two muscle-specific ubiquitin ligases (MAFbx and MuRF1), and of two inhibitors of protein synthesis, REDD1 and 4EBP1. MAFbx, MuRF1, REDD1 and 4EBP1 are up-regulated by the transcription factors FOXO1 and FOXO3A. The transcriptional co-activator PGC-1{alpha} has been shown to attenuate many forms of muscle atrophy and to repress FOXO3A-mediated transcription of atrophy-specific genes. Dexamethasone-induced muscle atrophy can be prevented by testosterone, which blocks up-regulation by dexamethasone of FOXO1. Here, an animal model of dexamethasone-induced muscle atrophy was used to further characterize effects of testosterone to abrogate adverse actions of dexamethasone on FOXO1 levels and nuclear localization, and to determine how these agents affect PGC-1{alpha}, and its upstream activators, p38 MAPK and AMPK. In rat gastrocnemius muscle, testosterone blunted the dexamethasone-mediated increase in levels of FOXO1 mRNA, and FOXO1 total and nuclear protein. Dexamethasone reduced total and nuclear PGC-1{alpha} protein levels in the gastrocnemius; co-administration of testosterone with dexamethasone increased total and nuclear PGC-1{alpha} levels above those present in untreated controls. Testosterone blocked dexamethasone-induced decreases in activity of p38 MAPK in the gastrocnemius

  6. Sequential sampling and analysis of renal hydroxylase activities of cattle given 1 alpha-hydroxyvitamin D3.

    PubMed

    Littledike, E T; Engstrom, G W; Sachs, M

    1986-04-01

    A new method was developed for sequential sampling of bovine renal cortex. This method results in minimum hemorrhage and adhesions and provides sufficient renal cortex tissue for assay of 25-hydroxyvitamin D 1 alpha-, 24-, and 23-hydroxylase activities. Application of this procedure in calves and pregnant cows treated with 1 alpha-hydroxyvitamin D3 is described. The success of these experiments suggests these techniques could be used to follow enzyme activities that control crucial aspects of vitamin D metabolism in normal peripartum cows and cows with milk fever or other diseases of mineral metabolism. PMID:3722540

  7. Characterization of the interaction between the prostaglandin D2 DP1 receptor and the intracellular L-prostaglandin D synthase.

    PubMed

    Binda, Chantal; Parent, Jean-Luc

    2015-01-01

    Identification of G protein-coupled receptor (GPCR)-interacting proteins is an intense subject of current research. However, confirmation and characterization of identified interactions can be difficult with GPCRs, especially at the endogenous level. Here, we describe how we characterized the interaction between the prostaglandin D2 DP1 receptor and the intracellular L-type prostaglandin D synthase by in vitro pull-down assays using purified recombinant GST- and His-tagged proteins, by co-immunoprecipitation of overexpressed Flag- and HA-tagged proteins, and by co-immunoprecipitation of endogenous proteins. PMID:25304348

  8. TEI-3313, a novel prostaglandin A1 derivative, prevents bone loss and enhances bone formation in immobilized male rats.

    PubMed

    Ohta, T; Azuma, Y; Kanatani, H; Kiyoki, M; Koshihara, Y

    1995-10-01

    The effect of a novel prostaglandin A1 derivative, TEI-3313, with the chemical structure 5-[(Z,2E)-4,7-dihydroxy-2-heptenyridene]-4-hydroxy- 2-methylthio-4-(4-phenoxybutyl)-2-cyclopentenone, on bone mineral content was investigated. Seven-week-old Sprague-Dawley rats in which the right hindlimbs were immobilized by sciatic nerve dissection received 1, 10, 100 or 500 micrograms of TEI-3313/kg/day, i.p., for 6 weeks. Control animals were operated on but received vehicle only. Bone mineral content of the femur was measured by single-photon absorptiometry, and biochemical parameters were analyzed. Histomorphometric observations were performed on the proximal metaphysial sections of the tibiae. The administration of up to 500 micrograms/kg of TEI-3313 to rats had no effect on body weight or on serum calcium, inorganic phosphorus and 1 alpha,25 dihydroxy vitamin D3 levels. Immobilization decreased the ash content, calcium content and total bone mineral content of the femur compared with nonimmobilization (unoperated femur). With TEI-3313 administration, changes in these parameters in the immobilized femur were prevented almost to the levels of the nonimmobilized femur, in a dose-dependent manner. The enhancement of bone mineral content was remarkable in the midshaft of the femur. TEI-3313 enhanced ash and calcium content and total bone mineral content in nonimmobilized femurs. Microradiograms showed that TEI-3313, unlike pamidronate and 17 beta-estradiol, had little inhibitory effect on trabecular bone resorption in the proximal portion of the tibia. TEI-3313 not only prevented the bone loss induced by immobilization but also increased bone mass in the nonimmobilized femurs without affecting the levels of 1 alpha,25 dihydroxy vitamin D3.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7562584

  9. Prostaglandin D(2) induces contraction via thromboxane A(2) receptor in rat liver myofibroblasts.

    PubMed

    Maruyama, Tomoharu; Murata, Takahisa; Ayabe, Shinya; Hori, Masatoshi; Ozaki, Hiroshi

    2008-09-01

    Increased intrahepatic resistance is one of the major characteristics of cirrhotic liver, in which extravascular cells including liver myofibroblasts (MFs) abnormally contract. Although several studies provided evidence that various prostaglandins (PG) are involved in liver cirrhosis, the role of PGD(2) remains unknown. In this study, we investigated the effect of PGD(2) on the contractile properties of liver MFs. Cultured rat liver MFs were used at passages 4-7. A collagen gel contraction assay was used for the evaluation of the MFs contraction. mRNA expression was assessed by semi-quantitative RT-PCR. Intracellular Ca(2+) concentrations ([Ca(2+)](i)) were measured by monitoring the fluorescence intensity of fura-2. PGD(2) (1-10 microM) induced liver MF contraction in a dose-dependent manner with [Ca(2+)](i) elevation. Pretreatment with 300 nM LaCl(3), a nonselective Ca(2+) channel blocker abolished the 10 microM PGD(2)-induced MFs contraction. RT-PCR revealed that three distinct PGD(2) responsive receptors, prostanoid DP receptor, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) and thromboxane A(2) receptor (prostanoid TP receptor), were expressed in liver MFs. While prostanoid DP receptor agonist and CRTH2 agonist didn't induce contraction, 0.01-1 microM U46619 (11alpha, 9alpha-epoxymethano-PGH(2), prostanoid TP receptor agonist) caused robust contraction with [Ca(2+)](i) elevation. Furthermore, pretreatment with prostanoid TP receptor antagonists ramatroban (1 microM) or SQ29548 ([1S-[1alpha, 2alpha(Z), 3alpha, 4alpha

  10. Effects of prostaglandin F2 alpha on bone formation and resorption in cultured neonatal mouse calvariae: Role of prostaglandin E2 production

    SciTech Connect

    Raisz, L.G.; Alander, C.B.; Fall, P.M.; Simmons, H.A. )

    1990-02-01

    Although most studies show that prostaglandin E2 (PGE2) is the most potent and effective of the prostanoids in bone, recent data in cell culture suggest that PGF2 alpha may have unique effects, particularly on cell replication. The present study was undertaken to compare the effects of PGF2 alpha and PGE2 in cultured neonatal mouse parietal bones by simultaneous measurement of bone resorption as release of previously incorporated 45Ca, bone formation as incorporation of (3H)proline into collagenase-digestible (CDP) and noncollagen protein, and DNA synthesis as incorporation of (3H)thymidine. PGF2 alpha was less effective than PGE2 as a stimulator of bone resorption, and its effects were partially inhibited by indomethacin and markedly inhibited by glucocorticoids. In contrast, the resorptive response to PGE2 was unaffected by indomethacin and only partially inhibited by cortisol. PGF2 alpha had little effect on bone formation, in contrast to the biphasic effect of PGE2, which inhibited labeling of CDP in the absence of cortisol and stimulated CDP labeling in the presence of cortisol. PGF2 alpha increased thymidine incorporation into DNA, but the effect was smaller than that of PGE2 and was inhibited by indomethacin. These observations suggested that PGF2 alpha might act in part by stimulating PGE2 production. By RIA, PGE2 concentrations were increased in the medium of bones treated with PGF2 alpha, and this increase was blocked by indomethacin. By HPLC, bones prelabeled with (3H)arachidonic acid showed an increase in labeled PGE2 release, and RIA showed an increase in PGE2 after PGF2 alpha treatment. These results indicate that PGF2 alpha is a relatively weak agonist in bone compared to PGE2 and that some of the effects of PGF2 alpha on bone resorption, formation, and cell replication may be mediated by an increase in endogenous PGE2 production.

  11. Existence of both IL-1 alpha and beta in normal human amniotic fluid: unique high molecular weight form of IL-1 beta.

    PubMed Central

    Tamatani, T; Tsunoda, H; Iwasaki, H; Kaneko, M; Hashimoto, T; Onozaki, K

    1988-01-01

    We investigated the possible existence of IL-1 in human amniotic fluid (AF). Since AF from most full-term deliveries appeared to contain an inhibitor(s) for thymocyte proliferation, AFs were fractionated by gel filtration prior to IL-1 assay. IL-1 activities eluted in two peaks at positions of 90,000-60,000 MW and 20,000-15,000 MW. Growth inhibitory activity eluted at the position of 70,000-50,000 MW, and its effect appeared to be non-specific because these fractions inhibited the growth of various cell lines. Using isoelectric focusing (IEF) techniques, pI values of 6.8-7.3 for the higher MW IL-1 as well as 4.9-5.5 and 6.7-7.0 for the lower MW IL-1 were obtained. Antibody against human IL-1 alpha partially neutralized the activity of the lower MW IL-1, though it exhibited little effect on the higher MW IL-1. In contrast, antibody against human IL-1 beta almost completely neutralized the activity of the higher MW IL-1 and partially neutralized the activity of the lower MW IL-1. These results suggest that most of the higher MW IL-1 is beta-type, and the lower MW IL-1 is a mixture of alpha and beta-types. IL-1 beta appeared to exist as a complex (combined with AF components) or as an aggregate of the lower MW IL-1 forms. These findings indicate that both IL-1 alpha and IL-1 beta are present in normal human AF from full-term deliveries, though IL-1 beta exists as a higher MW form aggregated with an unknown molecule. PMID:3264804

  12. Tumor necrosis factor alpha and interleukin-1 alpha stimulate late shedding of p75 TNF receptors but not p55 TNF receptors from human monocytes.

    PubMed

    Joyce, D A; Steer, J H

    1995-11-01

    Soluble receptors for TNF (sTNF-R) are present at elevated concentrations in the synovial fluid of patients with rheumatoid arthritis. They are presumably released by cells of the synovial membrane, including the monocyte-derived synovial macrophages. Cytokines from the synovium, including IL-1 and TNF-alpha, may stimulate release. We therefore examined the release of sTNF-R from monocytes exposed to IL-1 and TNF-alpha. Elutriator-purified human blood monocytes spontaneously released both the p75 and the p55 sTNF-R (1011 +/- 199 and 177 +/- 20 pg/10(6) cells, respectively, mean +/- SEM) during 48 h of in vitro culture. TNF-alpha and IL-1 alpha induced time- and concentration-dependent increases in the release of sTNF-R75 from monocytes, but neither had a measurable effect on the release of sTNF-R55. The release of sTNF-R75 was inhibited by cycloheximide. Neither lymphocytes nor polymorphonuclear leukocytes (PMN) released measurable sTNF-R spontaneously or in response to stimulation with IL-1 alpha, but TNF-alpha stimulated the release of small amounts of sTNF-R75 by PMN. The timing, cycloheximide sensitivity, and selectivity of stimulated release of TNF-R75 by monocytes are consistent with previous observations on other cell types of late (8-20 h) increased synthesis and turnover of cell surface TNF-R75, but not TNF-R55, after stimulation with TNF-alpha or IL-1. These observations help to explain why elevated levels of sTNF-R in synovial fluid coexist with enhanced expression of cell surface TNF-R on synovial macrophages in rheumatoid arthritis. PMID:8590306

  13. Roles of adrenomedullin and hypoxia-inducible factor 1 alpha in patients with varicocele.

    PubMed

    Hu, W; Zhou, P-H; Zhang, X-B; Xu, C-G; Wang, W

    2015-10-01

    This study aimed to assess any changes in the plasma concentrations of adrenomedullin (ADM) and hypoxia-inducible factor 1 alpha (HIF 1a) in patients with varicocele (VC). Plasma concentrations of ADM and HIF 1a were measured in brachial vein (BV) and internal spermatic vein (ISV) of 30 fertile VC subjects and 35 untreated infertile VC patients. The results demonstrated that plasma levels of ADM and HIF 1a were significantly higher in ISV than those in BV in the fertile or infertile group respectively. The values of ADM and HIF 1a in BV or ISV of the infertile group were significantly higher than in BV or ISV of the fertile group respectively. Similar changes in values of reactive oxygen metabolites (ROM) were observed. Plasma HIF 1a concentration positively correlated with ROM levels. Plasma ADM concentration positively correlated with ROM values and HIF 1a levels in the two groups. Moreover, remarkable improvement in clinical sperm parameters was observed 3 months after surgery for the infertile patients. It is concluded that ADM may participate, along with HIF 1a, in mechanisms that aid spermatogenic cells in adapting to hypoxia. These predictors may have potential in infertility development in VC patients. Furthermore, early surgical repair is extremely important for infertile VC patients with poor semen quality. PMID:25335788

  14. Drosophila glucome screening identifies Ck1alpha as a regulator of mammalian glucose metabolism

    PubMed Central

    Ugrankar, Rupali; Berglund, Eric; Akdemir, Fatih; Tran, Christopher; Kim, Min Soo; Noh, Jungsik; Schneider, Rebekka; Ebert, Benjamin; Graff, Jonathan M.

    2015-01-01

    Circulating carbohydrates are an essential energy source, perturbations in which are pathognomonic of various diseases, diabetes being the most prevalent. Yet many of the genes underlying diabetes and its characteristic hyperglycaemia remain elusive. Here we use physiological and genetic interrogations in D. melanogaster to uncover the ‘glucome', the complete set of genes involved in glucose regulation in flies. Partial genomic screens of ∼1,000 genes yield ∼160 hyperglycaemia ‘flyabetes' candidates that we classify using fat body- and muscle-specific knockdown and biochemical assays. The results highlight the minor glucose fraction as a physiological indicator of metabolism in Drosophila. The hits uncovered in our screen may have conserved functions in mammalian glucose homeostasis, as heterozygous and homozygous mutants of Ck1alpha in the murine adipose lineage, develop diabetes. Our findings demonstrate that glucose has a role in fly biology and that genetic screenings carried out in flies may increase our understanding of mammalian pathophysiology. PMID:25994086

  15. HIF-1alpha Deficiency Attenuates the Cardiomyogenesis of Mouse Embryonic Stem Cells

    PubMed Central

    Kudová, Jana; Procházková, Jiřina; Vašiček, Ondřej; Perečko, Tomáš; Sedláčková, Miroslava; Pešl, Martin; Pacherník, Jiří

    2016-01-01

    Cardiac cell formation, cardiomyogenesis, is critically dependent on oxygen availability. It is known that hypoxia, a reduced oxygen level, modulates the in vitro differentiation of pluripotent cells into cardiomyocytes via hypoxia inducible factor-1alpha (HIF-1α)-dependent mechanisms. However, the direct impact of HIF-1α deficiency on the formation and maturation of cardiac-like cells derived from mouse embryonic stem cells (mESC) in vitro remains to be elucidated. In the present study, we demonstrated that HIF-1α deficiency significantly altered the quality and quantity of mESC-derived cardiomyocytes. It was accompanied with lower mRNA and protein levels of cardiac cell specific markers (myosin heavy chains 6 and 7) and with a decreasing percentage of myosin heavy chain α and β, and cardiac troponin T-positive cells. As to structural aspects of the differentiated cardiomyocytes, the localization of contractile proteins (cardiac troponin T, myosin heavy chain α and β) and the organization of myofibrils were also different. Simultaneously, HIF-1α deficiency was associated with a lower percentage of beating embryoid bodies. Interestingly, an observed alteration in the in vitro differentiation scheme of HIF-1α deficient cells was accompanied with significantly lower expression of the endodermal marker (hepatic nuclear factor 4 alpha). These findings thus suggest that HIF-1α deficiency attenuates spontaneous cardiomyogenesis through the negative regulation of endoderm development in mESC differentiating in vitro. PMID:27355368

  16. Reducing prostaglandin E2 production to raise cancer immunogenicity

    PubMed Central

    Zelenay, Santiago; Reis e Sousa, Caetano

    2016-01-01

    ABSTRACT Cyclooxygenases (COX), commonly upregulated in numerous cancers, generate prostaglandin E2 (PGE2), which has been implicated in key aspects of malignant growth including proliferation, invasion and angiogenesis. Recently, we showed that production of PGE2 by cancer cells dominantly enables progressive tumor growth via immune escape and that cyclooxygenase inhibitors synergize with immunotherapy to enhance tumor eradication.

  17. Reducing prostaglandin E2 production to raise cancer immunogenicity.

    PubMed

    Zelenay, Santiago; Reis E Sousa, Caetano

    2016-05-01

    Cyclooxygenases (COX), commonly upregulated in numerous cancers, generate prostaglandin E2 (PGE2), which has been implicated in key aspects of malignant growth including proliferation, invasion and angiogenesis. Recently, we showed that production of PGE2 by cancer cells dominantly enables progressive tumor growth via immune escape and that cyclooxygenase inhibitors synergize with immunotherapy to enhance tumor eradication. PMID:27467936

  18. Prostaglandin E₂ constrains systemic inflammation through an innate lymphoid cell-IL-22 axis.

    PubMed

    Duffin, Rodger; O'Connor, Richard A; Crittenden, Siobhan; Forster, Thorsten; Yu, Cunjing; Zheng, Xiaozhong; Smyth, Danielle; Robb, Calum T; Rossi, Fiona; Skouras, Christos; Tang, Shaohui; Richards, James; Pellicoro, Antonella; Weller, Richard B; Breyer, Richard M; Mole, Damian J; Iredale, John P; Anderton, Stephen M; Narumiya, Shuh; Maizels, Rick M; Ghazal, Peter; Howie, Sarah E; Rossi, Adriano G; Yao, Chengcan

    2016-03-18

    Systemic inflammation, which results from the massive release of proinflammatory molecules into the circulatory system, is a major risk factor for severe illness, but the precise mechanisms underlying its control are not fully understood. We observed that prostaglandin E2 (PGE2), through its receptor EP4, is down-regulated in human systemic inflammatory disease. Mice with reduced PGE2 synthesis develop systemic inflammation, associated with translocation of gut bacteria, which can be prevented by treatment with EP4 agonists. Mechanistically, we demonstrate that PGE2-EP4 signaling acts directly on type 3 innate lymphoid cells (ILCs), promoting their homeostasis and driving them to produce interleukin-22 (IL-22). Disruption of the ILC-IL-22 axis impairs PGE2-mediated inhibition of systemic inflammation. Hence, the ILC-IL-22 axis is essential in protecting against gut barrier dysfunction, enabling PGE2-EP4 signaling to impede systemic inflammation. PMID:26989254

  19. 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.

  20. Mechanism of the Lower Esophageal Sphincter Relaxation ACTION OF PROSTAGLANDIN E1 AND THEOPHYLLINE

    PubMed Central

    Goyal, Raj K.; Rattan, Satish

    1973-01-01

    The intravenous injection of prostaglandin E1 (PGE1) causes a dose-dependent relaxation of the lower esophageal sphincter (LES) in the intact, lightly anesthetized opossum. The action of PGE1 is not inhibited by the drugs that produce muscarinic or nicotinic cholinergic antagonism or alpha and beta adrenergic antagonism in the doses that inhibited the action of respective agonists. Moreover, this action is not affected by exogenous gastrin pentapeptide. The action of PGE1 on the LES is mimicked by isoproterenol, theophylline ethylenediamine, and dibutyryl cyclic AMP. Both theophylline, a phosphodiesterase inhibitor, and isoproterenol, an adenyl cyclase stimulator, added to the action of PGE1. On the other hand, adenyl cyclase inhibitor nicotinic acid, as well as phosphodiesterase stimulator, imidazole inhibited its action. Further, both nicotinic acid and imidazole inhibited the degree of LES relaxation produced by esophageal distension. These studies suggest that intracellular cyclic AMP may act as the “second messenger” in the regulation of the lower esophageal sphincter relaxation. Images PMID:4346007

  1. Statins Modulate Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 in Human Hepatic Myofibroblasts.

    PubMed

    Mouawad, Charbel A; Mrad, May F; El-Achkar, Ghewa A; Abdul-Sater, Ali; Nemer, Georges M; Creminon, Christophe; Lotersztajn, Sophie; Habib, Aïda

    2016-05-01

    Statins have been shown to exert anti-inflammatory and anti-fibrogenic properties in the liver. In the present study, we explored the mechanisms underlying anti-fibrogenic effects of statins in isolated hepatic myofibroblasts and focused on cyclooxyegnase-2, a major anti-proliferative pathway in these cells. We show that simvastatin and fluvastatin inhibit thymidine incorporation in hMF in a dose-dependent manner. Pretreatment of cells with NS398, a COX-2 inhibitor, partially blunted this effect. cAMP levels, essential to the inhibition of hMF proliferation, were increased by statins and inhibited by non-steroidal anti-inflammatory drugs. Since statins modify prenylation of some important proteins in gene expression, we investigated the targets involved using selective inhibitors of prenyltransferases. Inhibition of geranylgeranylation resulted in the induction of COX-2 and mPGES-1. Using gel retardation assays, we further demonstrated that statins potentially activated the NFκB and CRE/E-box binding for COX-2 promoter and the binding of GC-rich regions and GATA for mPGES-1. Together these data demonstrate that statin limit hepatic myofibroblasts proliferation via a COX-2 and mPGES-1 dependent pathway. These data suggest that statin-dependent increase of prostaglandin in hMF contributes to its anti-fibrogenic effect. J. Cell. Biochem. 117: 1176-1186, 2016. © 2015 Wiley Periodicals, Inc. PMID:26477987

  2. 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.

  3. Whole-body in-vivo neutron activation analysis in assessing treatment of renal osteodystrophy with 1-alpha-hydroxycholecalciferol.

    PubMed

    Naik, R B; Gosling, P; Price, C P; Robinson, B H; Dabek, J T; Heath, D A; James, H M; Kanis, J A; Smith, R

    1976-07-10

    Four selected adults with different patterns of osteodystrophy receiving regular dialysis were treated with 1-alpha-hydroxycholecalciferol (1-alpha-OHD3) 0-5-2 mug/day for 10 to 12 months. In two patients, one with osteitis fibrosa and the other with osteomalacia, significant biochemical, radiological, and histological improvements occurred, and total body calcium measured by in-vivo neutron activation analysis increased. In two patients, in whom there were no increases of whole-body calcium, neither biochemical improvement nor healing of bone lesions occurred during the study; in one of these patients the effect of 1-alpha-OHD3 on bone resorption may have contributed to loss of body calcium and deterioration of bone disease. 1-alpha-OHD3 may therefore be a valuable adjunct in the treatment of only some patients with renal osteodystrophy. Whole-body in-vivo neutron activation seems to provide a sensitive and non-invasive index of early response to treatment. PMID:1276820

  4. The existence of 25-hydroxyvitamin D sub 3 -1. alpha. -hydroxylase in the liver of carp and bastard halibut

    SciTech Connect

    Takeuchi, Atsuko; Okano, Toshio; Kobayashi, Tadashi )

    1991-01-01

    We have found that carp and bastard halibut contain 25-hydroxyvitamin D{sub 3}(25-D{sub 3})-1{alpha}-hydroxylase in the liver besides in the kidney by the following in vivo and in vitro experiments. When ({sup 3}H)-25-D{sub 3} was intraperitoneally injected to vitamin D(D)-deficient carp and normal bastard halibut, the profiles of high-performance liquid chromatography (HPLC) of the plasma lipid extract showed the formation of a peak corresponding to ({sup 3}H)-1{alpha},25-dihydroxyvitamin D{sub 3}(1,25-D{sub 3}). When ({sup 3}H)25-D{sub 3} was incubated with liver homogenates of the fish, a peak corresponding to ({sup 3}H)-1,25-D{sub 3} was also observed in the profile of HPLC. The formation of the metabolite was confirmed by the thermal isomerization into the pre-isomer and mass fragmentography. Although the 1{alpha}-hydroxylase was also observed in the kidney, the activity of the enzyme was lower than that in the liver. The results suggest that 25-D{sub 3}-1{alpha}-hydroxylase exists in the liver of carp and bastard halibut and the 25-D{sub 3} formed from D{sub 3} in the liver is immediately metabolized into 1,25-D{sub 3} in the same tissue.

  5. Sesquiterpenes and an intermediate 1alpha, 6beta, 11-eudesmanetriol in the biosynthesis of geosmin from Streptomyces sp.

    PubMed

    Yang, Ya-Bin; Yang, Zhi; Yang, Xue-Qiong; Zhang, Yong; Zhao, Li-Xing; Xu, Li-Hua; Ding, Zhong-Tao

    2012-03-01

    One new sesquiterpene was isolated from the fermentation broth of Streptomyces sp. and the structure was elucidated by spectral analysis as caryolane-1, 6beta-diol (1). An intermediate 1alpha, 6beta, 11-eudesmanetriol (2) in the biosynthesis of geosmin was also found in this strain which proved sequence for the reactions, especially bicyclization preceding dealkylation. PMID:22645760

  6. An amino acid substitution in the pyruvate dehydrogenase E1{alpha} gene, affecting mitochondrial import of the precursor protein

    SciTech Connect

    Takakubo, F.; Thorburn, D.R.; Dahl, H.H.M.

    1995-10-01

    A mutation in the mitochondrial targeting sequence was characterized in a male patient with X chromosome-linked pyruvate dehydrogenase E1{alpha} deficiency. The mutation was a base substitution of G by C at nucleotide 134 in the mitochondrial targeting sequence of the PDHA1 gene, resulting in an arginine-to-proline substitution at codon 10 (R10P). Pyruvate dehydrogenase activity in cultured skin fibroblasts was 28% of the control value, and immunoblot analysis revealed a decreased level of pyruvate dehydrogenase E1{alpha}immunoreactivity. Chimeric constructs in which the normal and mutant pyruvate dehydrogenase E1{alpha} targeting sequences were attached to the mitochondrial matrix protein ornithine transcarbamylase were synthesized in a cell free translation system, and mitochondrial import of normal and mutant proteins was compared in vitro. The results show that ornithine transcarbamylase targeted by the mutant pyruvate dehydrogenase E1{alpha} sequence was translocated into the mitochondrial matrix at a reduced rate, suggesting that defective import is responsible for the reduced pyruvate dehydrogenase level in mitochondria. The mutation was also present in an affected brother and the mildly affected mother. The clinical presentations of this X chromosome-linked disorder in affected family members are discussed. To our knowledge, this is the first report of an amino acid substitution in a mitochondrial targeting sequence resulting in a human genetic disease. 58 refs., 5 figs., 1 tab.

  7. Hepatocyte nuclear factor-1alpha is required for expression but dispensable for histone acetylation of the lactase-phlorizin hydrolase gene in vivo.

    PubMed

    Bosse, Tjalling; van Wering, Herbert M; Gielen, Marieke; Dowling, Lauren N; Fialkovich, John J; Piaseckyj, Christina M; Gonzalez, Frank J; Akiyama, Taro E; Montgomery, Robert K; Grand, Richard J; Krasinski, Stephen D

    2006-05-01

    Hepatocyte nuclear factor-1alpha (HNF-1alpha) is a modified homeodomain-containing transcription factor that has been implicated in the regulation of intestinal genes. To define the importance and underlying mechanism of HNF-1alpha for the regulation of intestinal gene expression in vivo, we analyzed the expression of the intestinal differentiation markers and putative HNF-1alpha targets lactase-phlorizin hydrolase (LPH) and sucrase-isomaltase (SI) in hnf1alpha null mice. We found that in adult jejunum, LPH mRNA in hnf1alpha(-/-) mice was reduced 95% compared with wild-type controls (P < 0.01, n = 4), whereas SI mRNA was virtually identical to that in wild-type mice. Furthermore, SI mRNA abundance was unchanged in the absence of HNF-1alpha along the length of the adult mouse small intestine as well as in newborn jejunum. We found that HNF-1alpha occupies the promoters of both the LPH and SI genes in vivo. However, in contrast to liver and pancreas, where HNF-1alpha regulates target genes by recruitment of histone acetyl transferase activity to the promoter, the histone acetylation state of the LPH and SI promoters was not affected by the presence or absence of HNF-1alpha. Finally, we showed that a subset of hypothesized intestinal target genes is regulated by HNF-1alpha in vivo and that this regulation occurs in a defined tissue-specific and developmental context. These data indicate that HNF-1alpha is an activator of a subset of intestinal genes and induces these genes through an alternative mechanism in which it is dispensable for chromatin remodeling. PMID:16223943

  8. Pharmacophore Modeling and Virtual Screening for Novel Acidic Inhibitors of Microsomal Prostaglandin E2 Synthase-1 (mPGES-1)

    PubMed Central

    2011-01-01

    Microsomal prostaglandin E2 synthase-1 (mPGES-1) catalyzes prostaglandin E2 formation and is considered as a potential anti-inflammatory pharmacological target. To identify novel chemical scaffolds active on this enzyme, two pharmacophore models for acidic mPGES-1 inhibitors were developed and theoretically validated using information on mPGES-1 inhibitors from literature. The models were used to screen chemical databases supplied from the National Cancer Institute (NCI) and the Specs. Out of 29 compounds selected for biological evaluation, nine chemically diverse compounds caused concentration-dependent inhibition of mPGES-1 activity in a cell-free assay with IC50 values between 0.4 and 7.9 μM, respectively. Further pharmacological characterization revealed that also 5-lipoxygenase (5-LO) was inhibited by most of these active compounds in cell-free and cell-based assays with IC50 values in the low micromolar range. Together, nine novel chemical scaffolds inhibiting mPGES-1 are presented that may possess anti-inflammatory properties based on the interference with eicosanoid biosynthesis. PMID:21466167

  9. [Medical treatments and practices. What should be done when a prostaglandin proves ineffective?].

    PubMed

    Nordmann, J-P

    2005-06-01

    Prostaglandin analogs are very frequently used as first-line therapy in the treatment of glaucoma. In some cases, they may be ineffective or insufficient or they may induce side effects. The absence of an ocular pressure-lowering effect of a prostaglandin is in general a class effect. Thus a switch to another prostaglandin will probably not be more effective. In such cases, it may be better to use another therapeutic class. On the other hand, the side effects of prostaglandin are more often directly related to the chemical structure of the drug used and may not occur with another prostaglandin. Consequently, considering the dramatic effect of prostaglandin on ocular pressure compared to other drugs, when one prostaglandin causes side effects, it may be useful to try another one before changing the drug family. PMID:16208240

  10. The role of prostaglandins for the coordination of myometrial forces during labour.

    PubMed

    Wiqvist, N; Bryman, I; Lindblom, B; Norström, A; Wikland, M

    1985-01-01

    Systematic studies using a superfusion technique for recording myometrial contractility in vitro have been conducted in our department to explore whether prostaglandins (PG) have a differential action on the different segments of the pregnant uterus and also whether the qualitative and quantitative response undergoes a change during spontaneous labour. Myometrial specimens were excised from the fundal area and from the lower uterine segment at elective caesarean section in the 39th week of pregnancy before commencement of labour and at acute caesarean section during ongoing labour. Before labour PGF2 alpha was without or had a very weak effect on upper segment preparations but was stimulatory on lower segment specimens. PGE2 and PGI2 generally induced a biphasic dose-dependent response (stimulation followed by inhibition). During spontaneous labour PGF2 alpha and PGE2 always stimulated upper segment preparations while the contractile activity of specimens from the lower segment was inhibited by PGE2, PGF2 alpha was generally without effect. PGI2 had the same biphasic action before as during labour. With all reservations for the validity of in vitro experiments, the results favour the hypothesis that initiation of labour in the human involves a qualitative shift in the myometrial reactivity to prostaglandins. These alterations may involve suppression of expulsive forces and perhaps some tightening of the lower uterine segment during pregnancy. Following initiation of labour there is a marked increase in the excitatory action of both PGE2 and PGF2 alpha in the fundal area while the lower uterine segment reacts in a way that favours dilatation. PMID:3893037

  11. Long-term assessment of prostaglandin analogs and timolol fixed combinations vs prostaglandin analogs monotherapy

    PubMed Central

    Liu, Ai-Wei; Gan, Lin-Yang; Yao, Xiang; Zhou, Jian

    2016-01-01

    AIM To draw a Meta-analysis over the comparison of the intraocular pressure (IOP)-lowering efficacy and safety between the commonly used fixed-combinations of prostaglandin analogs and 0.5% timolol with prostaglandin analogs (PGAs) monotherapy. METHODS After searching the published reports from MEDLINE, EMBASE, the Cochrane Library, all randomized controlled clinical trials (RCTs) comparing the fixed combination of PGAs/timolol therapy (FCs) and PGAs monotherapy with treatment duration at least 6mo were included. The efficacy outcomes were mean diurnal IOP, percentage of participants whose IOP were lower than 18 mm Hg, incidence of visual field change, while the safety outcomes included corneal side effects, hyperemia and eye irritation. The analysis was carried out in RevMan version 5.3 software. RESULTS After six-month medical intervention, the mean diurnal IOP of FCs was lower than PGAs (MD -1.14, 95% CI -1.82 to -0.46, P=0.001); the percentage of target IOP achieving between FCs and PGAs showed no significant difference (RR 1.18, 95% CI 0.97 to 1.43, P=0.10). No statistically significant differences of the incidence of hyperemia (RR 0.67, 95% CI 0.45 to 1.01, P=0.06) and eye irritation (RR 1.20, 95% CI 0.95 to 1.51, P=0.12) between the FCs and PGAs monotherapy were detected. Only one research involved in corneal events, result of this trial revealed no difference between two intervention groups regarding corneal effects (central endothelial cell density, MD -0.20, 95% CI -0.72 to 0.32, P=0.45; central corneal thickness, MD -0.01, 95% CI -0.02 to 0.00, P=0.23). The evaluation of visual field change was not performed due to the limited duration of the trials included in this Meta-analysis. CONCLUSION The long-term efficacy of the FCs overweighed the PGAs monotherapy in lowering IOP, but in the incidence of hyperemia and eye irritation syndromes, the differences are not statically significant. More RCTs with detailed and authentic data over the assessments of

  12. In Vivo Therapeutic Silencing of Hypoxia-Inducible Factor 1 Alpha (HIF-1α) Using Single-Walled Carbon Nanotubes Noncovalently Coated with siRNA

    PubMed Central

    Bartholomeusz, Geoffrey; Cherukuri, Paul; Kingston, John; Cognet, Laurent; Lemos, Robert; Leeuw, Tonya K.; Gumbiner-Russo, Laura; Weisman, R. Bruce; Powis, Garth

    2009-01-01

    A new approach is described for delivering small interfering RNA (siRNA) into cancer cells by noncovalently complexing unmodified siRNA with pristine single-walled carbon nanotubes (SWCNTs). The complexes were prepared by simple sonication of pristine SWCNTs in a solution of siRNA, which then served both as the cargo and as the suspending agent for the SWCNTs. When complexes containing siRNA targeted to hypoxia-inducible factor 1 alpha (HIF-1α) were added to cells growing in serum containing culture media, there was strong specific inhibition of cellular HIF-1α activity. The ability to obtain a biological response to SWCNT/siRNA complexes was seen in a wide variety of cancer cell types. Moreover, intratumoral administration of SWCNT-HIF-1α siRNA complexes in mice bearing MiaPaCa-2/HRE tumors significantly inhibited the activity of tumor HIF-1α. As elevated levels of HIF-1α are found in many human cancers and are associated with resistance to therapy and decreased patient survival, these results imply that SWCNT/siRNA complexes may have value as therapeutic agents. PMID:20052401

  13. High glucose concentrations attenuate hypoxia-inducible factor-1{alpha} expression and signaling in non-tumor cells

    SciTech Connect

    Dehne, Nathalie; Bruene, Bernhard

    2010-04-15

    Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1{alpha} expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1{alpha} accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin. Transfection of C{sub 2}C{sub 12} cells with a HIF-1{alpha} oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O{sub 2} redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1{alpha} expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1{alpha} accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.

  14. Multiple Binding Modes between HNF4[alpha] and the LXXLL Motifs of PGC-1[alpha] Lead to Full Activation

    SciTech Connect

    Rha, Geun Bae; Wu, Guangteng; Shoelson, Steven E.; Chi, Young-In

    2010-04-15

    Hepatocyte nuclear factor 4{alpha} (HNF4{alpha}) is a novel nuclear receptor that participates in a hierarchical network of transcription factors regulating the development and physiology of such vital organs as the liver, pancreas, and kidney. Among the various transcriptional coregulators with which HNF4{alpha} interacts, peroxisome proliferation-activated receptor {gamma} (PPAR{gamma}) coactivator 1{alpha} (PGC-1{alpha}) represents a novel coactivator whose activation is unusually robust and whose binding mode appears to be distinct from that of canonical coactivators such as NCoA/SRC/p160 family members. To elucidate the potentially unique molecular mechanism of PGC-1{alpha} recruitment, we have determined the crystal structure of HNF4{alpha} in complex with a fragment of PGC-1{alpha} containing all three of its LXXLL motifs. Despite the presence of all three LXXLL motifs available for interactions, only one is bound at the canonical binding site, with no additional contacts observed between the two proteins. However, a close inspection of the electron density map indicates that the bound LXXLL motif is not a selected one but an averaged structure of more than one LXXLL motif. Further biochemical and functional studies show that the individual LXXLL motifs can bind but drive only minimal transactivation. Only when more than one LXXLL motif is involved can significant transcriptional activity be measured, and full activation requires all three LXXLL motifs. These findings led us to propose a model wherein each LXXLL motif has an additive effect, and the multiple binding modes by HNF4{alpha} toward the LXXLL motifs of PGC-1{alpha} could account for the apparent robust activation by providing a flexible mechanism for combinatorial recruitment of additional coactivators and mediators.

  15. SU-C-303-02: Correlating Metabolic Response to Radiation Therapy with HIF-1alpha Expression

    SciTech Connect

    Campos, D; Peeters, W; Nickel, K; Eliceiri, K; Kimple, R; Van Der Kogel, A; Kissick, M

    2015-06-15

    Purpose: To understand radiation induced alterations in cellular metabolism which could be used to assess treatment or normal tissue response to aid in patient-specific adaptive radiotherapy. This work aims to compare the metabolic response of two head and neck cell lines, one malignant (UM-SCC-22B) and one benign (Normal Oral Keratinocyte), to ionizing radiation. Responses are compared to alterations in HIF-1alpha expression. These dynamics can potentially serve as biomarkers in assessing treatment response allowing for patient-specific adaptive radiotherapy. Methods: Measurements of metabolism and HIF-1alpha expression were taken before and X minutes after a 10 Gy dose of radiation delivered via an orthovoltage x-ray source. In vitro changes in metabolic activity were measured via fluorescence lifetime imaging (FLIM) to assess the mean lifetime of NADH autofluorescence following a dose of 10 Gy. HIF-1alpha expression was measured via immunohistochemical staining of in vitro treated cells and expression was quantified using the FIJI software package. Results: FLIM demonstrated a decrease in the mean fluorescence lifetime of NADH by 100 ps following 10 Gy indicating a shift towards glycolytic pathways for malignant cells; whereas this benign cell line showed little change in metabolic signature. Immunohistochemical analysis showed significant changes in HIF-1alpha expression in response to 10 Gy of radiation that correlate to metabolic profiles. Conclusion: Radiation induces significant changes in metabolic activity and HIF-1alpha expression. These alterations occur on time scales approximating the duration of common radiation treatments (approximately tens of minutes). Further understanding these dynamics has important implications with regard to improvement of therapy and biomarkers of treatment response.

  16. HIF-1alpha and HIF-2alpha Are Differentially Activated in Distinct Cell Populations in Retinal Ischaemia

    PubMed Central

    Mowat, Freya M.; Luhmann, Ulrich F. O.; Smith, Alexander J.; Lange, Clemens; Duran, Yanai; Harten, Sarah; Shukla, Deepa; Maxwell, Patrick H.; Ali, Robin R.; Bainbridge, James W. B.

    2010-01-01

    Background Hypoxia plays a key role in ischaemic and neovascular disorders of the retina. Cellular responses to oxygen are mediated by hypoxia-inducible transcription factors (HIFs) that are stabilised in hypoxia and induce the expression of a diverse range of genes. The purpose of this study was to define the cellular specificities of HIF-1alpha and HIF-2alpha in retinal ischaemia, and to determine their correlation with the pattern of retinal hypoxia and the expression profiles of induced molecular mediators. Methodology/Principal Findings We investigated the tissue distribution of retinal hypoxia during oxygen-induced retinopathy (OIR) in mice using the bio-reductive drug pimonidazole. We measured the levels of HIF-1alpha and HIF-2alpha proteins by Western blotting and determined their cellular distribution by immunohistochemistry during the development of OIR. We measured the temporal expression profiles of two downstream mediators, vascular endothelial growth factor (VEGF) and erythropoietin (Epo) by ELISA. Pimonidazole labelling was evident specifically in the inner retina. Labelling peaked at 2 hours after the onset of hypoxia and gradually declined thereafter. Marked binding to Müller glia was evident during the early hypoxic stages of OIR. Both HIF-1alpha and HIF-2alpha protein levels were significantly increased during retinal hypoxia but were evident in distinct cellular distributions; HIF-1alpha stabilisation was evident in neuronal cells throughout the inner retinal layers whereas HIF-2alpha was restricted to Müller glia and astrocytes. Hypoxia and HIF-alpha stabilisation in the retina were closely followed by upregulated expression of the downstream mediators VEGF and EPO. Conclusions/Significance Both HIF-1alpha and HIF-2alpha are activated in close correlation with retinal hypoxia but have contrasting cell specificities, consistent with differential roles in retinal ischaemia. Our findings suggest that HIF-2alpha activation plays a key role in

  17. The expression of prostaglandin-E2 and its receptor in the oviduct of Chinese brown frog (Rana dybowskii).

    PubMed

    Hu, Ruiqi; Xi, Liqin; Cao, Qing; Yang, Rui; Liu, Yuning; Sheng, Xia; Han, Yingying; Yuan, Zhengrong; Guo, Yan; Weng, Qiang; Xu, Meiyu

    2016-07-01

    The Chinese brown frog (Rana dybowskii) has one special physiological phenomenon, which is that its oviduct expands prior to hibernation rather than in the breeding period. In this study, we investigated the immunolocalization and expression levels of prostaglandin-E2 (PGE2), cyclooxygenase (COX)-1 and COX-2, as well as one of its receptor subtypes 4 (EP4) in the oviduct of Rana dybowskii during the pre-hibernation and breeding period. PGE2, COX-1, COX-2 and EP4 have been observed in glandular and epithelial cells in the breeding period, whereas only in the epithelial cells during the pre-hibernation. Consistently, the protein levels of COX-2 and EP4 were higher in the pre-hibernation as compared to the breeding period, but the diversity of COX-1 was not obvious. In addition, oviductal PGE2 concentration was also significantly higher in the pre-hibernation. These results suggested that prostaglandin-E2 may play an important autocrine or paracrine role in oviductal cell proliferation and differentiation of Rana dybowskii during pre-hibernation. PMID:27246901

  18. Metabolic fate of radiolabeled prostaglandin D2 in a normal human male volunteer

    SciTech Connect

    Liston, T.E.; Roberts, L.J. 2d.

    1985-10-25

    50 microCi of (TH)prostaglandin D2 tracer (100 Ci/mmol) was infused intravenously into a normal human male volunteer. 75% of the infused radioactivity was excreted into the urine within 5 h. This urine was added to urine obtained from two mastocytosis patients with marked overproduction of prostaglandin D2. Radiolabeled prostaglandin D2 urinary metabolites were chromatographically isolated and purified and subsequently identified by gas chromatography-mass spectrometry. 25 metabolites were identified. 23 of these compounds comprising 37% of the recovered radioactivity had prostaglandin F-ring structures, and only two metabolites comprising 2.7% of the recovered radioactivity retained the prostaglandin D-ring structure. The single most abundant metabolite identified was 9,11-dihydroxy-15-oxo-2,3,18,19-tetranorprost-5-ene-1,20-dioic acid which was isolated in a tricyclic form as a result of formation of a lower side chain hemiketal followed by lactonization of the terminal carboxyl and the hemiketal hydroxyl. Different isomeric forms of several prostaglandin F-ring metabolites were identified. An isomer of prostaglandin F2 alpha was also excreted intact into the urine as a metabolite of prostaglandin D2. 15 PGF-ring compounds were treated with n-butylboronic acid and 13 failed to form a boronate derivative, suggesting that the orientation of the hydroxyl group at C-11 in these 13 metabolites is beta. This study documents that prostaglandin D2 is metabolized to prostaglandin F-ring metabolites in vivo in humans. These results also bring into question the accuracy of quantifying prostaglandin F2 alpha metabolites as a specific index of endogenous prostaglandin F2 alpha biosynthesis, as well as quantifying urinary prostaglandin F2 alpha as an accurate index of renal production of prostaglandin F2 alpha.

  19. Hypoxia-inducible factor 1 alpha in high-risk breast cancer: an independent prognostic parameter?

    PubMed Central

    Gruber, Günther; Greiner, Richard H; Hlushchuk, Ruslan; Aebersold, Daniel M; Altermatt, Hans J; Berclaz, Gilles; Djonov, Valentin

    2004-01-01

    Background Hypoxia-inducible factor 1 alpha (hif-1α) furnishes tumor cells with the means of adapting to stress parameters like tumor hypoxia and promotes critical steps in tumor progression and aggressiveness. We investigated the role of hif-1α expression in patients with node-positive breast cancer. Methods Tumor samples from 77 patients were available for immunohistochemistry. The impact of hif-1α immunoreactivity on survival endpoints was determined by univariate and multivariate analyses, and correlations to clinicopathological characteristics were determined by cross-tabulations. Results hif-1α was expressed in 56% (n = 43/77) of the patients. Its expression correlated with progesterone receptor negativity (P = 0.002). The Kaplan–Meier curves revealed significantly shorter distant metastasis-free survival (DMFS) (P = 0.04, log-rank) and disease-free survival (DFS) (P = 0.04, log-rank) in patients with increased hif-1α expression. The difference in overall survival (OS) did not attain statistical significance (5-year OS, 66% without hif-1α expression and 55% with hif-1α expression; P = 0.21). The multivariate analysis failed to reveal an independent prognostic value for hif-1α expression in the whole patient group. The only significant parameter for all endpoints was the T stage (T3/T4 versus T1/T2: DMFS, relative risk = 3.16, P = 0.01; DFS, relative risk = 2.57, P = 0.03; OS, relative risk = 3.03, P = 0.03). Restricting the univariate and multivariate analyses to T1/T2 tumors, hif-1α expression was a significant parameter for DFS and DMFS. Conclusions hif-1α is expressed in the majority of patients with node-positive breast cancer. It can serve as a prognostic marker for an unfavorable outcome in those with T1/T2 tumors and positive axillary lymph nodes. PMID:15084243

  20. Altered Hypoxia-inducible factor-1 alpha expression levels correlate with coronary vessel anomalies

    PubMed Central

    Wikenheiser, Jamie; Wolfram, Julie A.; Gargesha, Madhusudhana; Yang, Ke; Karunamuni, Ganga; Wilson, David L.; Semenza, Gregg L.; Agani, Faton; Fisher, Steven A.; Ward, Nicole; Watanabe, Michiko

    2009-01-01

    The outflow tract myocardium and other regions corresponding to the location of the major coronary vessels of the developing chicken heart, display a high level of hypoxia as assessed by the hypoxia indicator EF5. The EF5 positive tissues were also specifically positive for nuclear-localized hypoxia inducible factor-1 alpha (HIF-1α), the oxygen-sensitive component of the hypoxia inducible factor-1 (HIF-1) heterodimer. This led to our hypothesis that there is a “template” of hypoxic tissue that determines the stereotyped pattern of the major coronary vessels. In this study we disturbed this template by altering ambient oxygen levels (hypoxia 15%; hyperoxia 75-40%) during the early phases of avian coronary vessel development, in order to alter tissue hypoxia, HIF-1α protein expression and its downstream target genes without high mortality. We also altered HIF-1α gene expression in the embryonic outflow tract cardiomyocytes by injecting an adenovirus containing a constitutively active form of HIF-1α (AdCA5). We assayed for coronary anomalies using anti-alpha-smooth muscle actin immunohistology. When incubated under abnormal oxygen levels or injected with a low titer of the AdCA5, coronary arteries displayed deviations from their normal proximal connections to the aorta. These deviations were similar to known clinical anomalies of coronary arteries. These findings indicated that developing coronary vessels may be subject to a level of regulation that is dependent on differential oxygen levels within cardiac tissues and subsequent HIF-1 regulation of gene expression. PMID:19777592

  1. Hypoxia Inducible Factor 1 Alpha Is Expressed in Germ Cells throughout the Murine Life Cycle

    PubMed Central

    Gardner, Lauren H.; Mathews, Juanita; Yamazaki, Yuki; Allsopp, Richard C.

    2016-01-01

    Pluripotent stem cells of the early embryo, and germ line cells, are essential to ensure uncompromised development to adulthood as well as species propagation, respectively. Recently, the transcription factor hypoxia inducible factor 1 alpha (Hif1α) has been shown to have important roles in embryonic stem cells; in particular, regulation of conversion to glycolytic metabolism and, as we have shown, maintenance of functional levels of telomerase. In the present study, we sought to assess whether Hif1α was also expressed in the primitive cells of the murine embryo. We observed expression of Hif1α in pre-implantation embryos, specifically the 2-cell stage, morula, and blastocyst. Robust Hif1α expression was also observed in male and female primordial germ cells. We subsequently assessed whether Hif1α was expressed in adult male and female germ cells. In the testis, Hif1α was robustly expressed in spermatogonial cells, in both juvenile (6-week old) and adult (3-month old) males. In the ovaries, Hif1α was expressed in mature oocytes from adult females, as assessed both in situ and in individual oocytes flushed from super-ovulated females. Analysis of Hif1α transcript levels indicates a mechanism of regulation during early development that involves stockpiling of Hif1α protein in mature oocytes, presumably to provide protection from hypoxic stress until the gene is re-activated at the blastocyst stage. Together, these observations show that Hif1α is expressed throughout the life-cycle, including both the male and female germ line, and point to an important role for Hif1α in early progenitor cells. PMID:27148974

  2. Topography of prostaglandin H synthase. Antiinflammatory agents and the protease-sensitive arginine 253 region.

    PubMed

    Kulmacz, R J

    1989-08-25

    Prostaglandin H synthase catalyzes two reactions: the bis-dioxygenation of arachidonic acid to form prostaglandin G2 (cyclooxygenase activity), and the reduction of hydroperoxides to the corresponding alcohols (peroxidase activity). The cyclooxygenase activity can be selectively inhibited by many nonsteroidal antiinflammatory agents including indomethacin. In the native synthase, there is a single prominent protease-sensitive region, located near Arg253; binding of the heme prosthetic group makes the synthase resistant to proteases. To investigate the spatial relationship between the area of the synthase which interacts with indomethacin and the protease-sensitive region, the effects of indomethacin and similar agents on the protease sensitivity of the two enzymatic activities and of the synthase polypeptide were examined. Incubation of the synthase apoenzyme with trypsin (3.6% w/w) resulted in the time-dependent coordinate loss (75% at 1 h) of both enzymatic activities and the cleavage (85% at 1 h) of the 70-kDa subunit into 38- and 33-kDa fragments, indicating that proteolytic cleavage of the polypeptide at Arg253, destroyed both activities of the synthase simultaneously. Indomethacin, (S)-flurbiprofen, or meclofenamate (each at 20 microM) rendered both activities and the synthase polypeptide (at 5 microM subunit) resistant to attack by trypsin or proteinase K; these agents also inhibited the cyclooxygenase activity of the intact synthase. Two reversible cyclooxygenase inhibitors, ibuprofen and flufenamate, also made both of the activities and the synthase polypeptide more resistant to trypsin. Titration of the apoenzyme with indomethacin (0-3 mol/mol of synthase dimer) resulted in proportional increases in the inhibition of the cyclooxygenase and in the resistance to attack by trypsin. (R)-Flurbiprofen did not increase the resistance to protease or appreciably inhibit the cyclooxygenase. These results suggest that the same stereospecific interaction of these

  3. Impact of polyunsaturated fatty acids on hepato-pancreatic prostaglandin and leukotriene concentration in ductal pancreatic cancer -- is there a correlation to tumour growth and liver metastasis?

    PubMed

    Heukamp, I; Kilian, M; Gregor, J I; Kiewert, C; Schimke, I; Kristiansen, G; Walz, M K; Jacobi, C A; Wenger, F A

    2006-04-01

    Type and composition of polyunsaturated fatty acids (PUFAs) are suspected to play an important role in carcinogenesis. Thus we investigated the effects of n-3, n-6 and n-9 PUFAs on tumour growth, liver metastasis and concentration of prostaglandins (PG) and leukotrienes (LT) in experimental ductal pancreatic adenocarcinoma. Ninety male hamsters were randomised into six groups (Gr.) (n=15). While Gr. 1-3 were healthy control groups, Gr. 4-6 weekly received subcutaneous injections of 10mg N-nitrosobis-2-oxypropylamine (BOP)/kg body weight for 12 weeks in order to induce ductal pancreatic adenocarcinoma. Between week 1 and 16 all animals were fed with a standard diet with a raw fat content of 2.9%. In week 17 Gr. 1-6 were allocated to three types of diets: Gr. 1: standard high fat (=SHF diet, rich in n-6 PUFAs)/Gr. 2: FISH-OIL (rich in n-3 PUFAs)/Gr. 3: SMOF (=mixture of n-3, n-6 and n-9 PUFAs)/Gr. 4: BOP+SHF/Gr. 5: BOP+SMOF/Gr. 6: BOP+FISH-OIL. After 32 weeks all animals were sacrificed and pancreas as well as liver were analysed histologically. Furthermore pancreatic and hepatic concentrations of prostaglandins (PGF1alpha, PGE(2)) and LT were measured. FISH-OIL decreased number of macroscopically visible pancreatic tumours (Gr. 4-6: 54.5% vs. 45.5% vs. 9.1%, P<0.05) as well as incidence of liver metastasis (Gr. 4-6: 90.9% vs. 72.7% vs. 36.4%, P<0.05). Furthermore concentration of PGF(1)(alpha), PGE(2) and LT were significantly increased in pancreatic carcinoma compared to tumour-free tissue. Moreover levels of PGF(1)(alpha) and PGE(2) were higher in liver metastasis than in extrametastatic hepatic tissue. However, in Gr. 6 (FISH-OIL) intrametastatic concentration of LT was significantly lower than in non-metastatic hepatic tissue as well as in Gr. 4 and Gr. 5. FISH-OIL decreased number of visible pancreatic tumours and incidence of histological proven liver metastasis. This effect might be caused by a decrease of intrametastatic concentration of LT compared to

  4. Hypoxia-inducible factor-1 {alpha} expression predicts superior survival in patients with diffuse large B-cell lymphoma treated with R-CHOP.

    PubMed

    Evens, Andrew M; Sehn, Laurie H; Farinha, Pedro; Nelson, Beverly P; Raji, Adekunle; Lu, Yi; Brakman, Adam; Parimi, Vamsi; Winter, Jane N; Schumacker, Paul T; Gascoyne, Randy D; Gordon, Leo I

    2010-02-20

    PURPOSE Hypoxia-inducible factor (HIF) controls the expression of genes in response to hypoxia, as well as a wide range of other cellular processes. We previously showed constitutive stabilization of HIF-1alpha in the majority of patients with diffuse large B-cell lymphoma (DLBCL). To our knowledge, the prognostic significance of HIF in lymphoma has never been investigated. PATIENTS AND METHODS We studied the immunohistochemical protein expression of HIF-1alpha on tissue microarrays from 153 patients with DLBCL treated in sequential cohorts with cyclophosphamide, doxorubicin, oncovin, and prednisone (CHOP) or rituximab-CHOP (R-CHOP) from 1999 to 2002. Results were correlated with patient outcome. Results Median follow-up for all patients was 80 months. Among all patients, HIF-1alpha was expressed in 62% of germinal center and 59% of non-germinal center patients. With HIF-1alpha analyzed as a dependent variable, there were no survival differences in CHOP-treated patients. In the R-CHOP group, however, HIF-1alpha protein expression correlated with significantly improved progression-free survival (PFS) and overall survival (OS). Five-year PFS for HIF-1alpha-positive patients was 71% v 43% for HIF-1alpha-negative patients (P = .0187), whereas 5-year OS was 75% and 54%, respectively (P = .025). In multivariate analysis with International Prognostic Index criteria, HIF-1alpha remained a significant predictor for PFS (P = .026) and OS (P = .043). Compared with other biomarkers, HIF-1alpha correlated only with BCL6 (P = .004). In terms of gene expression, we found several common gene associations of HIF-1alpha and the stromal-1 signature with genes predominantly involved in regulation of the extracellular matrix (eg, BGN, COL1A2, COL5A1, and PLOD2). CONCLUSION The expression of HIF-1alpha protein is an important independent favorable prognostic factor for survival in patients with DLBCL treated with R-CHOP. PMID:20048181

  5. A catalytically-inactive snake venom Lys49 phospholipase A₂ homolog induces expression of cyclooxygenase-2 and production of prostaglandins through selected signaling pathways in macrophages.

    PubMed

    Moreira, Vanessa; de Castro Souto, Pollyana Cristina Maggio; Ramirez Vinolo, Marco Aurélio; Lomonte, Bruno; María Gutiérrez, José; Curi, Rui; Teixeira, Catarina

    2013-05-15

    The effects of a snake venom Lys-49 phospholipase A2 (PLA2) homolog named MT-II, devoid of enzymatic activity, on the biosynthesis of prostaglandins and protein expression of cyclooxygenase-2 (COX-2) and signaling pathways involved were evaluated in mouse macrophages in culture and in peritoneal cells ex vivo. Stimulation of macrophages with MT-II leads to production of prostaglandin D2 (PGD2) and prostaglandin E2 (PGE2) and protein expression of COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1). Inhibition of cytosolic PLA2 (cPLA2), but not Ca(2+) independent PLA2 (iPLA2) reduced release of PGD2 and PGE2 and expression of COX-2 induced by MT-II. Inhibition of nuclear factor κB (NF-κB) significantly reduced MT-II-induced PGE2, but not PGD2 production and COX-2 expression. Inhibitors of either protein kinase C (PKC), protein tyrosine kinase (PTK), or extracellular signal-regulated kinase (ERK) pathways abrogated MT-II-induced NF-κB activation and reduced COX-2 expression and PGE2 release, whereas the p38 mitogen-activated protein kinase (MAPK) inhibitor reduced MT-II-induced COX-2 expression and PGD2 production. Inhibition of phosphatidylinositol-3-kinase (PI3K) pathway abrogated MT-II-induced NF-κB activation, but affected neither prostaglandins production nor COX-2 expression. MT-II-induced production of PGD2 and PGE2 and COX-2 expression were also observed in vivo after intraperitoneal injection into mice. Collectively, our data demonstrate that a catalytically-inactive PLA2 homolog is capable of inducing prostaglandins biosynthesis and COX-2 expression in macrophages in both in vitro and in vivo models, indicating that the enzymatic activity of PLA2 is not necessary to trigger these effects. MT-II-activated NF-κB, cPLA2 and distinct protein kinases are the principal steps involved in these cellular events. PMID:23416211

  6. Prostaglandin uptake and metabolism by the perfused rat liver

    PubMed Central

    Dawson, W.; Jessup, Sheila J.; McDonald-Gibson, Wendy; Ramwell, P. W.; Shaw, Jane E.

    1970-01-01

    1. The prostaglandins are C20 unsaturated fatty acids which exhibit diverse physiological effects of short duration. We have investigated the speed of removal of PGE1 and PGF1α from the circulating blood and their subsequent metabolism by the isolated perfused rat liver. 2. Following either a single injection of radiolabelled PGE1 or PGF1α into the hepatic artery or portal vein, or recirculation of prostaglandins through the liver for 2·5 h, the distribution of radioactivity within extracts of bile, blood and liver was determined. The nature of the radioactive products of meta-bolism was inferred by comparison of the distribution of radioactivity after injecting carbon and tritium labelled standards, and by thin-layer chromatography, gas-liquid chromatography, ultraviolet and bioassay analysis. 3. A single injection of 1-14C PGE1 indicated that the liver could efficiently remove 89-95% of circulating PGE1 on a single passage. Biliary excretion was excluded as a major route for elimination of unchanged PGE1, because only 0·3-0·8% of the injected radioactivity was detected in the bile. During recirculation of 1-14C PGE1, 11-19% of the injected radioactivity was detected as exchanged 14CO2. The radioactivity detected within liver was identified with further fragments resulting from decarboxylation of PGE1, which were incorporated into fatty acids and then phospholipids. 4. Studies with 5,6-3H PGE1, and comparison with the results obtained using 1-14C PGE1, revealed a 30-fold increase in the percentage of radioactivity excreted into the bile, suggesting that biliary excretion may be a major route for elimination of compounds smaller than C20 prostaglandin. Evidence that the cyclopentane ring was intact was inferred by formation of a PGB compound on treatment with alkali; similar biliary excretion of 9-3H PGF1α also occurred. In addition, the increased radioactivity detected within the liver (37%) and blood (43%) after a single injection of 5,6-3H PGE1 had the

  7. Steroid signalling in human ovarian surface epithelial cells: the response to interleukin-1alpha determined by microarray analysis.

    PubMed

    Rae, M T; Niven, D; Ross, A; Forster, T; Lathe, R; Critchley, H O D; Ghazal, P; Hillier, S G

    2004-10-01

    The human ovarian surface epithelium (HOSE) is a common site of gynaecological disease including endometriosis and ovarian cancer, probably due to serial injury-repair events associated with successive ovulations. To comprehend the importance of steroid signalling in the regulation of the HOSE, we used a custom microarray to catalogue the expression of over 250 genes involved in the synthesis and reception of steroid hormones, sterols and retinoids. The array included a subset of non-steroidogenic genes commonly involved in pro-/anti-inflammatory signalling. HOSE cells donated by five patients undergoing surgery for non-malignant gynaecological conditions were cultured for 48 h in the presence and absence of 500 pg/ml interleukin-1alpha (IL-1alpha). Total RNA was reverse-transcribed into biotin-labelled cDNA, which was hybridised to the array and visualised by gold-particle resonance light scattering and charge-coupled device (CCD) camera detection. Results for selected genes were verified by quantitative reverse-transcription PCR. In five out of five cases, untreated HOSE cells expressed genes encoding enzymes required for de novo biosynthesis of cholesterol from acetate and subsequent formation of C21-pregnane and C19-androstane steroids. Consistent with the inability of HOSE cells to synthesise glucocorticoids, oestrogens or 5alpha-reduced androgens de novo, CYP21, CYP19 and 5alpha-reductase were not detected. The only steroidogenic gene significantly up-regulated by IL-1alpha was 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1). Other cytokine-induced genes were IL-6, IL-8, nuclear factor kappaB (NFkappaB) inhibitor alpha, metallothionein-IIA and lysyl oxidase: inflammation-associated genes that respond to glucocorticoids. The only steroidogenic gene significantly suppressed by IL-1alpha was 3betaHSD1. Other genes suppressed by IL-1alpha were aldehyde dehydrogenase (ALDH) 1, ALDH 10, gonadotrophin hormone-releasing hormone receptor, peroxisome

  8. Radioimmune assay of human platelet prostaglandin synthetase

    SciTech Connect

    Roth, G.J.; Machuga, E.T.

    1982-02-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH/sub 2/ from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and (/sup 125/I)-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the (/sup 125/I)antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10/sup 9/ platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency.

  9. Studies on the metabolism of prostaglandin D/sub 2/ in humans

    SciTech Connect

    Liston, T.E.

    1985-01-01

    Fifty ..mu..Ci of (/sup 3/H)-prostaglandin D/sub 2/ tracer (100 Ci/mMole) was infused intravenously into a normal human male volunteer. Seventy-five percent of the infused radioactivity was excreted into the urine within 5 hours. This urine was added to urine obtained from two mastocytosis patients with marked overproduction of prostaglandin D/sub 2/. Twenty-five radiolabelled prostaglandin D/sub 2/ urinary metabolites were chromatographically isolated and purified and subsequently identified by gas chromatography-mass spectrometry. Twenty-three of these metabolites, comprising 37% of the recovered radioactivity, had prostaglandin F-ring structures, and only 2 metabolites, comprising 2.7% of the recovered radioactivity retained the prostaglandin D-ring structure. The single most abundant metabolite identified was 9,11-dihydroxy-15-oxo-2,3,18,19-tetranorprost-5-energy-1,20-dioic acid which was isolated in a tricyclic form. Different isomeric forms of several prostaglandin F-ring metabolites were identified. To further investigate the metabolism of prostaglandin D/sub 2/, in vitro studies examining the metabolic transformation of prostaglandin D/sub 2/ by human liver were conducted. This study documents that prostaglandin D/sub 2/ is metabolized to PGF-ring metabolites in vivo in humans, and is converted to a structurally new prostaglandin, 9/sub ..cap alpha../, 11/sub ..beta../-PGF/sub 2/ in vitro by a cytosolic NADPH-dependent 11-Ketoreductase in the human liver.

  10. Metabolism of prostaglandin F2 alpha in Zellweger syndrome. Peroxisomal beta-oxidation is a major importance for in vivo degradation of prostaglandins in humans.

    PubMed Central

    Diczfalusy, U; Kase, B F; Alexson, S E; Björkhem, I

    1991-01-01

    We have recently shown in vitro that the peroxisomal fraction of a rat liver homogenate has the highest capacity to beta-oxidize prostaglandins. In order to evaluate the relative importance of peroxisomes for this conversion also in vivo, we administered [3H]prostaglandin F2 alpha to an infant suffering from Zellweger syndrome, a congenital disorder characterized by the absence of intact peroxisomes. As a control, labeled compound was administered to two healthy volunteers. Urine was collected, fractionated on a SEP-PAK C18 cartridge, and subjected to reversed-phase high-performance liquid chromatography. The Zellweger patient was found to excrete prostaglandin metabolites considerably less polar than those of the control subjects. The major urinary metabolite in the control subjects was practically absent in the urine from the Zellweger patient. The major urinary prostaglandin F2 alpha metabolite from the Zellweger patient was identified as an omega-oxidized C20-prostaglandin, 9,11-dihydroxy-15-oxoprost-5-ene-1,20-dioic acid. The major urinary prostaglandin F2 alpha metabolite from the control subjects had chromatographic properties of a tetranor (C16) prostaglandin, in accordance with earlier published data. The present results, in combination with our previous in vitro data, indicate that peroxisomal beta-oxidation is of major importance for in vivo chain shortening of prostaglandins. PMID:1885782

  11. Solute concentration affects bradykinin-mediated increases in renal prostaglandin E2

    SciTech Connect

    Zenser, T.V.; Davis, E.S.; Rapp, N.S.; Davis, B.B.

    1981-12-01

    The effects of solute concentration on the bradykinin-mediated increase in inner medullary slice prostaglandin E2 (PGE2) synthesis were investigated. PG content was determined by specific RIA. Bradykinin stimulation was prevented by the addition of the following solutes to Krebs buffer: 1.0 M urea, 0.5 or 1.0 M NaCl, 0.5 or 1.0 M mannitol, 1.0 M urea plus 0.5 M NaCl, or 1.0 M mannitol plus 0.5 M NaCl. By contrast, basal PGE2 synthesis was increased by 1.0 M mannitol or by 1.0 M mannitol plus 0.5 M NaCl, but decreased by 1.0 M urea. Urea elicited a concentration-dependent, reversible inhibition of bradykinin stimulation, with 0.01 M urea being the lowest effective concentration. By contrast, basal PGE2 synthesis was only reduced at a urea concentration greater than 0.6 M. Arachidonic acid-mediated increases in both PGE2 and PGF2 alpha synthesis were not prevented by 1.0 M urea. The latter suggests that neither PG endoperoxide synthetase nor PG endoperoxide E isomerase are inhibited by urea. The data indicate that different hypertonic solutions have different effects on basal PG production, but all inhibit bradykinin stimulation.

  12. Discovery and Characterization of 2-Acylaminoimidazole Microsomal Prostaglandin E Synthase-1 Inhibitors.

    PubMed

    Schiffler, Matthew A; Antonysamy, Stephen; Bhattachar, Shobha N; Campanale, Kristina M; Chandrasekhar, Srinivasan; Condon, Bradley; Desai, Prashant V; Fisher, Matthew J; Groshong, Christopher; Harvey, Anita; Hickey, Michael J; Hughes, Norman E; Jones, Scott A; Kim, Euibong J; Kuklish, Steven L; Luz, John G; Norman, Bryan H; Rathmell, Richard E; Rizzo, John R; Seng, Thomas W; Thibodeaux, Stefan J; Woods, Timothy A; York, Jeremy S; Yu, Xiao-Peng

    2016-01-14

    As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 μM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus other mechanisms in the prostanoid pathway. These factors led to the selection of 26 as a second clinical candidate. PMID:26653180

  13. Recovery from hematopoietic injury by modulating prostaglandin E(2) signaling post-irradiation.

    PubMed

    Hoggatt, Jonathan; Singh, Pratibha; Stilger, Kayla N; Plett, P Artur; Sampson, Carol H; Chua, Hui Lin; Orschell, Christie M; Pelus, Louis M

    2013-03-01

    While high dose total body irradiation (TBI) is used therapeutically, the proliferation of nuclear weapons, increasing use of nuclear power, and worldwide radical terrorism underscore the need to develop countermeasures to a radiological mass casualty event. The hematopoietic syndrome of the acute radiation syndrome (HS-ARS) results from severe compromise to the hematopoietic system, including lymphocytopenia, neutropenia, thrombocytopenia, and possible death from infection and/or hemorrhage. Given adequate time to recover, expand, and appropriately differentiate, bone marrow hematopoietic stem cells (HSC) and progenitor cells (HPC) may overcome HS-ARS and restore homeostasis of the hematopoietic system. Prostaglandin E(2) (PGE(2)) has been shown to have pleiotropic effects on hematopoiesis, acting to inhibit apoptosis and promote self-renewal of HSC, while inhibiting HPC proliferation. We assessed the radio-mitigating potential of modulating PGE(2) signaling in a mouse model of HS-ARS. Treatment with the PGE(2) analog 16,16 dimethyl PGE(2) (dmPGE(2)) 6h post-irradiation or inhibition of PGE(2) synthesis via delayed administration of the non-steroidal anti-inflammatory drug (NSAID) Meloxicam resulted in increased survival of lethally irradiated mice. Both early dmPGE(2) and delayed Meloxicam treatment were associated with increased HPC activity 35days following irradiation, demonstrating enhanced recovery of hematopoiesis. Our results define two different treatment modalities that are highly effective and safe to administer, and can be readily available. PMID:23206586

  14. Isolation and characterization of three cassava elongation factor 1 alpha (MeEF1A) promoters.

    PubMed

    Suhandono, Sony; Apriyanto, Ardha; Ihsani, Nisa

    2014-01-01

    In plant genetic engineering, the identification of gene promoters leading to particular expression patterns is crucial for the development of new genetically modified plant generations. This research was conducted in order to isolate and characterize several new promoters from cassava (Manihot esculenta Crantz) elongation factor 1 alpha (EF1A) gene family.Three promoters MeEF1A3, MeEF1A5 and MeEF1A6 were successfully isolated [corrected]. Sequence analyses showed that all of the promoters contain three conserved putative cis-acting elements which are located upstream of the transcription start site. These elements are included a TEF1, a TELO and TATA boxes. In addition, all of the promoters also have the 5'UTR intron but with a different lengths. These promoters were constructed translationally with gusA reporter gene (promoter::gusA fusion) in pBI-121 binary vector to build a new binary vector using Overlap Extension PCR Cloning (OEPC) technique. Transient expression assay that was done by using agroinfiltration method was used to show functionality of these promoters. Qualitative and quantitative analysis from GUS assay showed that these promoters were functional and conferred a specific activity in tobacco seedlings (Nicotiana tabacum), tomato fruits (Solanum lycopersicum) and banana fruits (Musa acuminata). We hypothesized that MeEF1A6 could be categorized as a constitutive promoter because it was able to drive the gene expression in all transformed tissue described in here and also comparable to CaMV35S. On the other hand, MeEF1A3 drove specific expression in the aerial parts of seedlings such as hypocotyl and cotyledon thus MeEF1A5 drove specific expression in fruit tissue. The results obtained from transient analysis showed that these promoters had a distinct activity although they came from same gene family. The DNA sequences identified here are new promoters potentially use for genetic engineering in cassava or other plants. PMID:24404183

  15. HIF-1alpha Expression Profile in Intratumoral and Peritumoral Inflammatory Cells as a Prognostic Marker for Squamous Cell Carcinoma of the Oral Cavity

    PubMed Central

    Mendes, Suzanny Oliveira; dos Santos, Marcelo; Peterle, Gabriela Tonini; Maia, Lucas de Lima; Stur, Elaine; Agostini, Lidiane Pignaton; de Carvalho, Marcos Brasilino; Tajara, Eloiza Helena; Louro, Iúri Drumond; Trivilin, Leonardo Oliveira; da Silva-Conforti, Adriana Madeira Álvares

    2014-01-01

    The HIF-1 transcriptional complex is responsible for controlling transcription of over 100 genes involved in cell hypoxia response. HIF-1alpha subunit is stabilized in hypoxia conditions, creating the HIF-1 nuclear transcription factor. In inflammatory cells, high HIF-1alpha expression induces lymphocytic immunosuppression, decreasing tumoral antigen recognition, which promotes tumor growth. The present work investigated the relationship between HIF-1alpha expression in lymphocytes populating the intratumoral and peritumoral region of 56 patients with oral cancer. Our data indicates a prognostic value for this expression. High HIF-1alpha expression in peritumoral inflammatory cells is significantly related to worse patient outcome, whereas high expression in the intratumoral lymphoid cells correlates with a better prognosis. A risk profile indicating the chance of disease relapse and death was designed based on HIF-1alpha expression in tumoral inflammatory cells, defining low, intermediate and high risks. This risk profile was able to determine that high HIF-1alpha expression in peritumoral cells correlates with worse prognosis, independently of intratumoral expression. Low HIF-1alpha in tumor margins and high expression in the tumor was considered a low risk profile, showing no cases of disease relapse and disease related death. Intermediate risk was associated with low expression in tumor and tumor margins. Our results suggest that HIF-1alpha expression in tumor and peritumoral inflammatory cells may play an important role as prognostic tumor marker. PMID:24416312

  16. Activation of Dll4/Notch Signaling and Hypoxia-Inducible Factor-1 Alpha Facilitates Lymphangiogenesis in Lacrimal Glands in Dry Eye

    PubMed Central

    Ji, Yong Woo; Yeo, Areum; Noh, Hyemi; Song, Insil; Kim, Eung Kweon; Lee, Hyung Keun

    2016-01-01

    Purpose By using hypoxia-inducible factor-1 alpha conditional knockout (HIF-1α CKO) mice and a dry eye (DE) mouse model, we aimed to determine the role played by delta-like ligand 4 (Dll4)/Notch signaling and HIF-1α in the lymphangiogenesis of lacrimal glands (LGs). Methods C57BL/6 mice were housed in a controlled-environment chamber for DE induction. During DE induction, the expression level of Dll4/Notch signaling and lymphangiogenesis in LGs was measured by quantitative RT-PCR, immunoblot, and immunofluorescence staining. Next, lymphangiogenesis was measured after Dll4/Notch signal inhibition by anti-Dll4 antibody or γ-secretase inhibitor. Using HIF-1α CKO mice, the expression of Dll4/Notch signaling and lymphangiogenesis in LGs of DE-induced HIF-1α CKO mice were assessed. Additionally, the infiltration of CD45+ cells in LGs was assessed by immunohistochemical (IHC) staining and flow cytometry for each condition. Results DE significantly upregulated Dll4/Notch and lymphangiogenesis in LGs. Inhibition of Dll4/Notch significantly suppressed lymphangiogenesis in LGs. Compared to wild-type (WT) mice, DE induced HIF-1α CKO mice showed markedly low levels of Dll4/Notch and lymphangiogenesis. Inhibition of lymphangiogenesis by Dll4/Notch suppression resulted in increased CD45+ cell infiltration in LGs. Likewise, CD45+ cells infiltrated more in the LGs of HIF-1α CKO DE mice than in non-DE HIF-1α CKO mice. Conclusions Dll4/Notch signaling and HIF-1α are closely related to lymphangiogenesis in DE-induced LGs. Lymphangiogenesis stimulated by Dll4/Notch and HIF-1α may play a role in protecting LGs from DE-induced inflammation by aiding the clearance of immune cells from LGs. PMID:26828208

  17. [Novel treatment for prostate cancer targeting prostaglandins].

    PubMed

    Terada, Naoki; Inoue, Takahiro; Kamba, Tomomi; Ogawa, Osamu

    2014-12-01

    PGE2 is highly expressed in the prostate, associating with prostate cancer progression. Targeting downstream signaling pathways of PGE2 may represent an attractive new strategy for the treatment of prostate cancer. We have established a novel prostate cancer xenograft model, KUCaP-2. The expression of EP4, one of PGE2 receptors, was significantly up-regulated during the development of castration resistance. A specific EP4 antagonist, ONO-AE3-208, decelerated castration-resistant growth of KUCaP-2 tumors in vivo. Moreover, ONO-AE3-208 could in vitro inhibit the cell invasion and in vivo suppress the bone metastasis of prostate cancer cells. These results indicated that EP4 is a novel target for the treatment of metastatic castration resistant prostate cancer. PMID:25518348

  18. Mechanical stimulation of skeletal muscle increases prostaglandin F2(alpha) synthesis and cyclooxygenase activity by a pertussis toxin sensitive mechanism

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.; Shansky, Janet; Solerssi, Rosa; Chromiak, Joseph

    1992-01-01

    Repetitive mechanical stimulation of differentiated skeletal muscle in tissue culture increases the production of prostaglandin F(sub 2(alpha)), an anabolic stimulator of myofiber growth. Within 4 h of initiating mechanical activity, the activity of cyclooxygenase, a regulatory enzyme in prostaglandin synthesis, was increased 82% (P is less than .005), and this increase was maintained for at least 24 h. Kinetic analysis of the stretch-activated cyclooxygenase indicated a two to three-fold decrease in the enzyme's K(sub m) with no change in V(sub max). The stretch-induced increase in enzymatic activity was not inhibited by cycloheximide, was independent of cellular electrical activity (tetrodotoxin-insensitive), but was prevented by the G protein inhibitor pertussis toxin. Pertussis toxin also inhibited the stretch-induced increases in PGF(sub 2(alpha)) production, and cell growth. It is concluded that stretch of skeletal muscle increases the synthesis of the anabolic modulator PGF(sub 2(alpha)) by a G protein-dependent process which involves activation of cyclooxygenase by a posttranslational mechanism.

  19. Cytoprotective effect of prostaglandin E2 in irradiated rat ileum

    SciTech Connect

    Tomas-de la Vega, J.E.; Banner, B.F.; Hubbard, M.; Boston, D.L.; Thomas, C.W.; Straus, A.K.; Roseman, D.L.

    1984-01-01

    Radiation injury to the gastrointestinal tract is an infrequent but major clinical problem. Results of previous studies have shown that prostaglandins provide cytoprotection of the gastrointestinal mucosa against a variety of noxious agents, although, prior to this study, the protection against radiation exposure had not been documented. Exteriorized segment of Sprague-Dawley rat ileum was radiated with 10 and 15 Gy (/sup 137/Cs). One group of rats was pretreated with prostaglandin E2 one hour before and 24 hours after radiation injury. The rats were sacrificed three and five days following radiation injury. Morphometric measurement of mucosal thickness, villous height, crypt of Lieberkuehn height and number of mitoses per square millimeter swath of tissue were analyzed. Also, /sup 125/IUdR and /sup 3/HTdR were injected in a group of rats radiated with 15 Gy (/sup 137/Cs). /sup 125/IUdR counts per minute per milligram of dry weight and /sup 3/HTdR labeled cells were counted and analyzed. The morphometric measurements and radioactive labeled tissue counts suggest that prostaglandin E2 has a cytoprotective effect upon irradiated rat ileum. Speculations about the possible mechanism and usefulness of this observation are included.

  20. Expression of 1alpha-HYD and 24-HYD in bovine kidney mediated by vitamin D3 supplementation.

    PubMed

    Rezende, L R; Delgado, E F; Júnior, A R L; Gasparin, G; Jorge, E C; Mourão, G B; Coutinho, L L

    2013-01-01

    In order to better understand vitamin D3 in cattle metabolism, we quantified 1alpha-HYD and 24-HYD gene expression. In the kidneys of 35 male Nellore cattle, these were divided into a control group and two treatment groups (2 x 10(6) international units of vitamin D3 administered for 2 or 8 consecutive days pre-slaughter). Vitamin D3 supplementation resulted in a significant increase in 1alpha-HYD gene expression; however, significantly increased 24-HYD gene expression was only detected in cattle that had 8 days of supplementation. The finding of upregulation of 24-HYD due to vitamin D supplementation is in line with the expected rise in 24,25-di-hydroxy-vitamin D3 synthesis observed when plasma vitamin D3 concentrations are high, stimulating excretion by the organism. On the other hand, upregulation of 1alpha-HYD was unexpected, since vitamin D3 supplementation has been reported to impact these two genes in opposite directions. We conclude that vitamin D3 metabolism in these animals is more complex than previously reported. PMID:24391007

  1. Evaluation of the role of prostaglandins E and F in acalculous gallbladder disease

    SciTech Connect

    Deshpande, Y.G.; Kaminski, D.L.; Thomas, L.

    1986-03-01

    Prostaglandins have been shown to play a role in gallbladder disease. This study was performed to evaluate prostaglandin E and F production by human gallbladder mucosal cells and muscle tissue from patients undergoing cholecystectomy for acalculous gallbladder disease. These results were compared to values produced by gall bladders removed from patients with no known gallbladder disease. Five patient underwent cholecystectomy for acute and five for chronic acalculous cholecystitis. Gallbladder mucosal cells were separated from muscle wall by submucosal injection of EDTA and shaking in tissue culture media. Prostaglandin levels were measured in mucosal cell and muscle tissue homogenate by radioimmunoassay (ng/mg homogenate protein). Homogenate prostaglandin E concentrations were significantly increased in mucosa and muscle tissue in gall bladders from patients with acute acalculous cholecystitis. Chronic acalculous gallbladder disease was not associated with changes in prostaglandin formation when compared to values produced by gall bladders from asymptomatic patients. Acute acalculous cholecystitis may be a prostaglandin mediated disorder.

  2. Prostaglandin E2 decreases fetal breathing movements, but not pulmonary blood flow, in fetal sheep.

    PubMed

    Savich, R D; Guerra, F A; Lee, C C; Kitterman, J A

    1995-04-01

    Fetal breathing movements are vital for normal fetal lung growth. Inhibition of these fetal breathing movements is associated with pulmonary hypoplasia. Pulmonary hypoplasia also occurs subsequent to alterations in other factors, such as a significant decrease in pulmonary blood flow. The prostaglandin system is known to have profound effects on both fetal breathing movements and on the pulmonary vascular system. We studied six late-gestation chronically instrumented fetal sheep by using an electromagnetic flow transducer around the left pulmonary artery to determine whether a decrease in fetal breathing movements, subsequent to a continuous infusion of prostaglandin E2 (PGE2), is associated with a decrease in pulmonary blood flow. A continuous PGE2 infusion of 0.88 +/- 0.11 microgram.kg-1.min-1 over 120 min led to a significant decrease in fetal breathing movements (control 40.5 +/- 3.6%, infusion 3.3 +/- 1.6%; P < 0.001). In contrast, the PGE2 infusion had no effect on mean left pulmonary artery blood flow (control 27.7 +/- 9.3 ml.min-1.kg-1, infusion 23.8 +/- 7.0 ml.min-1.kg-1. The PGE2 infusion demonstrated central effects in the percentage of time the fetus was in high-voltage electrocortical activity (control 41.9 +/- 2.5%, infusion 56.5 +/- 5.4%; P < 0.05) and in the amount of time spent in low-voltage electrocortical activity without fetal breathing movements (control 17.5 +/- 2.7%, infusion 40.2 +/- 4.8%; P < 0.05). A significant decrease in the fetal heart rate during the infusion was seen with no effect on either the systemic or pulmonary blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7615458

  3. Effects of dimethyl prostaglandin A1 on herpes simplex virus and human immunodeficiency virus replication

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.; McGrath, M. S.; Hanks, D.; Erickson, S.; Pulliam, L.

    1992-01-01

    We have investigated the direct effect of dimethyl prostaglandin A1 (dmPGA1) on the replication of herpes simplex virus (HSV) and human immunodeficiency virus type 1 (HIV-1). dmPGA1 significantly inhibited viral replication in both HSV and HIV infection systems at concentrations of dmPGA1 that did not adversely alter cellular DNA synthesis. The 50% inhibitory concentration (ID50) for several HSV type 1 (HSV-1) strains ranged from 3.8 to 5.6 micrograms/ml for Vero cells and from 4.6 to 7.3 micrograms/ml for human foreskin fibroblasts. The ID50s for two HSV-2 strains varied from 3.8 to 4.5 micrograms/ml for Vero cells; the ID50 was 5.7 micrograms/ml for human foreskin fibroblasts. We found that closely related prostaglandins did not have the same effect on the replication of HSV; dmPGE2 and dmPGA2 caused up to a 60% increase in HSV replication compared with that in untreated virus-infected cells. HIV-1 replication in acutely infected T cells (VB line) and chronically infected macrophages was assessed by quantitative decreases in p24 concentration. The effective ID50s were 2.5 micrograms/ml for VB cells acutely infected with HIV-1 and 5.2 micrograms/m for chronically infected macrophages. dmPGA1 has an unusual broad-spectrum antiviral activity against both HSV and HIV-1 in vitro and offers a new class of potential therapeutic agents for in vivo use.

  4. [Hematopoietic prostaglandin D synthase inhibitors for the treatment of duchenne muscular dystrophy].

    PubMed

    Kamauchi, Shinya; Urade, Yoshihiro

    2011-11-01

    Duchenne muscular dystrophy (DMD) is a severe X-linked muscle disease, characterized by progressive skeletal muscle atrophy and weakness. DMD is caused by mutations in the dystrophin gene, which encodes for the cytoskeletal protein dystrophin. DMD is one of the most common types of muscular dystrophies, affecting approximately 1 in 3,500 boys. There is no complete cure for this disease. Clinical trials for gene transfer therapy as a treatment for DMD have been performed but mainly in animal models. Hematopoietic prostaglandin (PG) D synthase (H-PGDS) was found to be induced in grouped necrotic muscle fibers of DMD patients and animal models, mdx mice, and DMD dogs. We found an orally active H-PGDS inhibitor (HQL-79) and determined the 3D structure of the inhibitor-human H-PGDS complex by X-ray crystallography. Oral administration of HQL-79 markedly suppressed prostaglandin D2 (PGD2) production, reduced necrotic muscle volume, and improved muscle strength in mdx dystrophic mice. Based on the high-resolution 3D structures of the inhibitor-H-PGDS complex, we designed alternative H-PGDS inhibitors, which were 100- to 3000-times more potent than HQL-79, as assessed by in vitro and in vivo analyses. We used these novel inhibitors for the treatment of DMD dogs and confirmed that oral administration of these inhibitors prevented skeletal muscle atrophy and weakness by decreasing PGD2 production. These results indicate that PGD2, synthesized by H-PGDS, is involved in the expansion of muscle necrosis in DMD. Thus, inhibition of H-PGDS by using inhibitors is a novel therapy for DMD. PMID:22068479

  5. Activation of prostaglandin E2-EP4 signaling reduces chemokine production in adipose tissue.

    PubMed

    Tang, Eva H C; Cai, Yin; Wong, Chi Kin; Rocha, Viviane Z; Sukhova, Galina K; Shimizu, Koichi; Xuan, Ge; Vanhoutte, Paul M; Libby, Peter; Xu, Aimin

    2015-02-01

    Inflammation of adipose tissue induces metabolic derangements associated with obesity. Thus, determining ways to control or inhibit inflammation in adipose tissue is of clinical interest. The present study tested the hypothesis that in mouse adipose tissue, endogenous prostaglandin E2 (PGE2) negatively regulates inflammation via activation of prostaglandin E receptor 4 (EP4). PGE2 (5-500 nM) attenuated lipopolysaccharide-induced mRNA and protein expression of chemokines, including interferon-γ-inducible protein 10 and macrophage-inflammatory protein-1α in mouse adipose tissue. A selective EP4 antagonist (L161,982) reversed, and two structurally different selective EP4 agonists [CAY10580 and CAY10598] mimicked these actions of PGE2. Adipose tissue derived from EP4-deficient mice did not display this response. These findings establish the involvement of EP4 receptors in this anti-inflammatory response. Experiments performed on adipose tissue from high-fat-fed mice demonstrated EP4-dependent attenuation of chemokine production during diet-induced obesity. The anti-inflammatory actions of EP4 became more important on a high-fat diet, in that EP4 activation suppressed a greater variety of chemokines. Furthermore, adipose tissue and systemic inflammation was enhanced in high-fat-fed EP4-deficient mice compared with wild-type littermates, and in high-fat-fed untreated C57BL/6 mice compared with mice treated with EP4 agonist. These findings provide in vivo evidence that PGE2-EP4 signaling limits inflammation. In conclusion, PGE2, via activation of EP4 receptors, functions as an endogenous anti-inflammatory mediator in mouse adipose tissue, and targeting EP4 may mitigate adipose tissue inflammation. PMID:25510249

  6. Identification and pharmacological characterization of the prostaglandin FP receptor and FP receptor variant complexes

    PubMed Central

    Liang, Y; Woodward, D F; Guzman, V M; Li, C; Scott, D F; Wang, J W; Wheeler, L A; Garst, M E; Landsverk, K; Sachs, G; Krauss, A H-P; Cornell, C; Martos, J; Pettit, S; Fliri, H

    2008-01-01

    Background and purpose: A prostamide analogue, bimatoprost, has been shown to be effective in reducing intraocular pressure, but its precise mechanism of action remains unclear. Hence, to elucidate the molecular mechanisms of this effect of bimatoprost, we focused on pharmacologically characterizing prostaglandin FP receptor (FP) and FP receptor variant (altFP) complexes. Experimental approach: FP receptor mRNA variants were identified by reverse transcription-polymerase chain reaction. The FP-altFP4 heterodimers were established in HEK293/EBNA cells co-expressing FP and altFP4 receptor variants. A fluorometric imaging plate reader was used to study Ca2+ mobilization. Upregulation of cysteine-rich angiogenic protein 61 (Cyr61) mRNA was measured by Northern blot analysis, and phosphorylation of myosin light chain (MLC) by western analysis. Key results: Six splicing variants of FP receptor mRNA were identified in human ocular tissues. Immunoprecipitation confirmed that the FP receptor is dimerized with altFP4 receptors in HEK293/EBNA cells co-expressing FP and altFP4 receptors. In the studies of the kinetic profile for Ca2+ mobilization, prostaglandin F2α (PGF2α) elicited a rapid increase in intracellular Ca2+ followed by a steady state phase. In contrast, bimatoprost elicited an immediate increase in intracellular Ca2+ followed by a second phase. The prostamide antagonist, AGN211335, selectively and dose-dependently inhibited the bimatoprost-initiated second phase of Ca2+ mobilization, Cyr61 mRNA upregulation and MLC phosphorylation, but did not block the action of PGF2α. Conclusion and implications: Bimatoprost lacks effects on the FP receptor but may interact with the FP-altFP receptor heterodimer to induce alterations in second messenger signalling. Hence, FP-altFP complexes may represent the underlying basis of bimatoprost pharmacology. PMID:18587449

  7. Prostaglandin E{sub 2} regulates melanocyte dendrite formation through activation of PKC{zeta}

    SciTech Connect

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

    2007-11-01

    Prostaglandins are lipid signaling intermediates released by keratinocytes in response to ultraviolet irradiation (UVR) in the skin. The main prostaglandin released following UVR is PGE{sub 2}, a ligand for 4 related G-protein-coupled receptors (EP{sub 1}, EP{sub 2}, EP{sub 3} and EP{sub 4}). Our previous work established that PGE{sub 2} stimulates melanocyte dendrite formation through activation of the EP{sub 1} and EP{sub 3} receptors. The purpose of the present report is to define the signaling intermediates involved in EP{sub 1}- and EP{sub 3}-dependent dendrite formation in human melanocytes. We recently showed that activation of the atypical PKC{zeta} isoform stimulates melanocyte dendricity in response to treatment with lysophosphatidylcholine. We therefore examined the potential contribution of PKC{zeta} activation on EP{sub 1}- and EP{sub 3}-dependent dendrite formation in melanocytes. Stimulation of the EP{sub 1} and EP{sub 3} receptors by selective agonists activated PKC{zeta}, and inhibition of PKC{zeta} activation abrogated EP{sub 1}- and EP{sub 3}-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 EP{sub 1} and EP{sub 3} receptor activation on Rac and Rho activity. Neither Rac nor Rho was activated upon treatment with EP{sub 1,3}-receptor agonists. We show that melanocytes express only the EP{sub 3A1} isoform, but not the EP{sub 3B} receptor isoform, previously associated with Rho activation, consistent with a lack of Rho stimulation by EP{sub 3} agonists. Our data suggest that PKC{zeta} activation plays a predominant role in regulation of PGE{sub 2}-dependent melanocyte dendricity.

  8. Effect of prostaglandins and cyclic adenosine 3',5'-monophosphate modulators on herpes simplex virus growth and interferon response in human cells.

    PubMed Central

    Trofatter, K F; Daniels, C A

    1980-01-01

    Mechanisms whereby prostaglandins and other cyclic adenosine 3',5'-monophosphate (cAMP) modulators might enhance the growth of herpes simplex virus (HSV) in human skin fibroblasts were explored. Prostaglandins A1, B1, E1, E2, and F2 alpha, as well as isoproterenol, imidazole, carbamylcholine, and dibutyryl cAMP had no effect on HSV growth. On the other hand, the phosphodiesterase inhibitors 1-methyl-3-isobutylxanthine and theophylline delayed the growth, suppressed the cell-to-cell spread, but inhibited neither the adsorption nor the penetration of the virus. Although none of the cAMP-elevating reagents directly enhanced HSV growth, they were found to inhibit dose dependently the antiviral action of both type I and HSV antigen-induced human interferon preparations. Furthermore, these reagents suppressed the production of HSV antigen-induced interferon by immune human mononuclear leukocytes. These data support the hypothesis that prostaglandin elaboration in vivo could contribute to exacerbations of HSV infections by compromising the host's interferon defense system. PMID:6244226

  9. Attenuation of Ischemic Liver Injury by Prostaglandin E1 Analogue, Misoprostol, and Prostaglandin I2 Analogue, OP-41483

    PubMed Central

    Totsuka, Eishi; Todo, Satoru; Zhu, Yue; Ishizaki, Naoki; Kawashima, Yoshiyuki; Jin, Maeng Bong; Urakami, Atsushi; Shimamura, Tsuyoshi; Starzl, Thomas E

    2010-01-01

    Background Prostaglandin has been reported to have protective effects against liver injury. Use of this agent in clinical settings, however, is limited because of drug-related side effects. This study investigated whether misoprostol, prostaglandin E1 analogue, and OP-41483, prostaglandin I2 analogue, which have fewer adverse effects with a longer half-life, attenuate ischemic liver damage. Study Design Thirty beagle dogs underwent 2 hours of hepatic vascular exclusion using venovenous bypass. Misoprostol was administered intravenously for 30 minutes before ischemia and for 3 hours after reperfusion. OP-41483 was administered intraportally for 30 minutes before ischemia (2 μg/kg/min) and for 3 hours after reperfusion (0.5 μg/kg/min). Animals were divided into five groups: untreated control group (n = 10); high-dose misoprostol (total 100 μg/kg) group (MP-H, n = 5); middle-dose misoprostol (50 μg/kg) group (MP-M, n = 5); low-dose misoprostol (25 μg/kg) group (MP-L, n = 5); and OP-41483 group (OP, n = 5). Animal survival, hepatic tissue blood flow (HTBF), liver function, and histology were analyzed. Results Two-week animal survival rates were 30% in control, 60% in MP-H, 100% in MP-M, 80% in MP-L, and 100% in OP. The treatments with prostaglandin analogues improved HTBF, and attenuated liver enzyme release, adenine nucleotrides degradation, and histologic abnormalities. In contrast to the MP-H animals that exhibited unstable cardiovascular systems, the MP-M, MP-L, and OP animals experienced only transient hypotension. Conclusions These results indicate that misoprostol and OP-41483 prevent ischemic liver damage, although careful dose adjustment of misoprostol is required to obtain the best protection with minimal side effects. PMID:9740185

  10. Mechanical stimulation of skeletal muscle cells mitigates glucocorticoid-induced decreases in prostaglandin production and prostaglandin synthase activity

    NASA Technical Reports Server (NTRS)

    Chromiak, J. A.; Vandenburgh, H. H.

    1994-01-01

    The glucocorticoid dexamethasone (Dex) induces a decline in protein synthesis and protein content in tissue cultured, avian skeletal muscle cells, and this atrophy is attenuated by repetitive mechanical stretch. Since the prostaglandin synthesis inhibitor indomethacin mitigated this stretch attenuation of muscle atrophy, the effects of Dex and mechanical stretch on prostaglandin production and prostaglandin H synthase (PGHS) activity were examined. In static cultures, 10(-8) M Dex reduced PGF2 alpha production 55-65% and PGE2 production 84-90% after 24-72 h of incubation. Repetitive 10% stretch-relaxations of non-Dex-treated cultures increased PGF2 alpha efflux 41% at 24 h and 276% at 72 h, and increased PGE2 production 51% at 24 h and 236% at 72 h. Mechanical stimulation of Dex-treated cultures increased PGF2 alpha production 162% after 24 h, returning PGF2 alpha efflux to the level of non-Dex-treated cultures. At 72 h, stretch increased PGF2 alpha efflux 65% in Dex-treated cultures. Mechanical stimulation of Dex-treated cultures also increased PGE2 production at 24 h, but not at 72 h. Dex reduced PGHS activity in the muscle cultures by 70% after 8-24 h of incubation, and mechanical stimulation of the Dex-treated cultures increased PGHS activity by 98% after 24 h. Repetitive mechanical stimulation attenuates the catabolic effects of Dex on cultured skeletal muscle cells in part by mitigating the Dex-induced declines in PGHS activity and prostaglandin production.

  11. The use of prostaglandins and their analogues for abortion.

    PubMed

    Bygdeman, M

    1984-12-01

    In general, termination of second trimester pregnancy is associated with three to five times higher morbidity and mortality risks than termination during the first trimester. The procedures mainly used are extra- or intra-amniotic administration of solutions such as hypertonic saline, ethacridine lactate, PGF2 alpha and PGE2. In comparison with these procedures, the use of prostaglandin analogues may offer important advantages, the most important one being the possibility of using non-invasive routes of administration. The continuous development of new analogues has now resulted in compounds that are highly effective in stimulating uterine contractility and are associated with a low frequency of side-effects; these compounds are suitable for both vaginal and intramuscular administration and are applicable for termination of pregnancy during both the early and late parts of the second trimester. The most widely used method for termination of first trimester pregnancy is vacuum aspiration. It is a highly effective procedure and the overall complication rate is low. One problem with vacuum aspiration is the mechanical dilatation of the cervical canal which is necessary from at least the 8th week and onwards. Pretreatment with laminaria tents or with prostaglandin analogues eliminates or reduces the need for mechanical dilatation and significantly facilitates the procedure. Pretreatment with prostaglandin analogues also reduces the risk of both operative and postoperative complications. The prostaglandins also offer a possibility as a non-surgical procedure for termination of very early pregnancy. Both vaginal and intramuscular administration of the latest generation of PG analogues have been shown in several studies to be equally as effective as vacuum aspiration if the treatment is restricted to the first three weeks following the first missed menstrual period. Gastrointestinal side-effects are still a problem although of significantly less importance than if natural

  12. Ionomycin induces prostaglandin E2 formation in murine osteoblastic MC3T3-E1 cells via mechanisms independent of its ionophoric nature.

    PubMed

    Leis, Hans Jörg; Windischhofer, Werner

    2016-06-01

    Ionomycin and A23187 are divalent cation ionophores with a marked preference for calcium. Studies using these ionophores have almost exclusively interpreted their results in the light of calcium elevation. It was the aim of this study to investigate the effects of ionomycin in osteoblatic MC3T3-E1 cells that are not attributable to its ionophoric properties. Thus, we have found that in contrast to A23187, ionomycin shows similar effects on prostaglandin E2 formation as bradykinin and endothelin-1, being potentiated by extracellular nickel and inhibited by cholera toxin and pertussis toxin. Our data strongly suggest that inomycin, at least in part, exerts its effects via specific binding to a G-protein coupled receptor, thereby evoking downstream cellular events like arachidonate release with subsequent prostaglandin formation. PMID:27065246

  13. Prostaglandin E2 and Prostaglandin F2α Differentially Modulate Matrix Metabolism of Human Nucleus Pulposus Cells

    PubMed Central

    Vo, Nam V.; Sowa, Gwendolyn A.; Kang, James D.; Seidel, Christopher; Studer, Rebecca K.

    2016-01-01

    Prostaglandin (PG) actions on disc metabolism are unclear even though certain PGs are highly expressed by disc cells under inflammatory conditions and nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used to block PG production to treat back pain. Hence this study aimed to (1) quantify gene expression of arachidonic acid cascade components responsible for PG synthesis and (2) examine the effects of key PGs on disc matrix homeostasis. Microarray analysis revealed that inflammatory stress increases expression of synthases and receptors for prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α), resulting in elevated PGE2 and PGF2α production in conditioned media of disc cells. PGE2 diminished disc cell proteoglycan synthesis, in a dose-dependent manner. Semiquantitative RT-PCR revealed differential effects of PGE2 and PGF2α on disc cell expression of key matrix structural genes, aggrecan, versican, collagens type I and II. PGE2 and PGF2α also decreased message for the anabolic factor, IGF-1. PGE2 decreased mRNA expression for the anti-catabolic factor TIMP-1 while PGF2α increased mRNAs for catabolic factors MMP-1 and MMP-3. Thus, PGE2 and PGF2α may have an overall negative impact on disc matrix homeostasis, and the use of NSAIDs may impact disc metabolism as well as treat back pain. PMID:20839316

  14. Synthesis of prostaglandins by conjugate addition and alkylation of a directed enolate ion. 4,5-allenyl prostaglandins

    SciTech Connect

    Patterson, J.W. )

    1990-09-28

    Over the previous two decades many elegant syntheses of prostaglandins, which in more sophisticated forms, allow the stereospecific introduction of the various asymmetric carbons have been accomplished. However, among these approaches the cuprate addition/enolate alkylation of suitable cyclopentenone {sup 2} stands out because of brevity and convergence. The recent reports by Noyori{sup 3} and Corey{sup 4} and their colleagues have reduced to practice the conversion of 4-alkoxycyclopentenones to prostaglandin E{sub 2} (PGE{sub 2}) by conjugate addition of an organocopper derivative of the lower side chain followed by alkylation of the resulting carbanion with methyl 7-halohept-2-enoate. The subject of this paper is application of the Tardella tin enolate alkylation developed by Noyori to the synthesis of 4, 5-allenic prostaglandins, a pharmacologically important class of compounds. The authors results demonstrate that the tandem alkylation of an enone precursor with a cuprate reagent followed by alkylation of the corresponding tin enolate with bromide reagent is a viable synthetic method for 4,5-didehydro-PGE{sub 2}. Because the optically active forms of 1 and the vinyl iodide precursor of the PGE{sub 2} lower side chain have been employed to produce a single enantiomer of PGE{sub 2}, the extension of the methodology described here to the synthesis of single enantiomers of 4a awaits only the preparation of the separate enantiomers of allene 14.

  15. Mutant HNF-1{alpha} and mutant HNF-1{beta} identified in MODY3 and MODY5 downregulate DPP-IV gene expression in Caco-2 cells

    SciTech Connect

    Gu Ning; Adachi, Tetsuya; Matsunaga, Tetsuro; Takeda, Jun; Tsujimoto, Gozoh; Ishihara, Akihiko; Yasuda, Koichiro; Tsuda, Kinsuke . E-mail: jinkan@tom.life.h.kyoto-u.ac.jp

    2006-08-04

    Dipeptidylpeptidase IV (DPP-IV) is a well-documented drug target for the treatment of type 2 diabetes. Hepatocyte nuclear factors (HNF)-1{alpha} and HNF-1{beta}, known as the causal genes of MODY3 and MODY5, respectively, have been reported to be involved in regulation of DPP-IV gene expression. But, it is not completely clear (i) that they play roles in regulation of DPP-IV gene expression, and (ii) whether DPP-IV gene activity is changed by mutant HNF-1{alpha} and mutant HNF-1{beta} in MODY3 and MODY5. To explore these questions, we investigated transactivation effects of wild HNF-1{alpha} and 13 mutant HNF-1{alpha}, as well as wild HNF-1{beta} and 2 mutant HNF-1{beta}, on DPP-IV promoter luciferase gene in Caco-2 cells by means of a transient experiment. Both wild HNF-1{alpha} and wild HNF-1{beta} significantly transactivated DPP-IV promoter, but mutant HNF-1{alpha} and mutant HNF-1{beta} exhibited low transactivation activity. Moreover, to study whether mutant HNF-1{alpha} and mutant HNF-1{beta} change endogenous DPP-IV enzyme activity, we produced four stable cell lines from Caco-2 cells, in which wild HNF-1{alpha} or wild HNF-1{beta}, or else respective dominant-negative mutant HNF-1{alpha}T539fsdelC or dominant-negative mutant HNF-1{beta}R177X, was stably expressed. We found that DPP-IV gene expression and enzyme activity were significantly increased in wild HNF-1{alpha} cells and wild HNF-1{beta} cells, whereas they decreased in HNF-1{alpha}T539fsdelC cells and HNF-1{beta}R177X cells, compared with DPP-IV gene expression and enzyme activity in Caco-2 cells. These results suggest that both wild HNF-1{alpha} and wild HNF-1{beta} have a stimulatory effect on DPP-IV gene expression, but that mutant HNF-1{alpha} and mutant HNF-1{beta} attenuate the stimulatory effect.

  16. An evaluation of vulvomucosal injections of prostaglandins for induction of parturition in swine

    PubMed Central

    Friendship, Robert M.; Templeton, Catherine L.; Deckert, Anne E.

    1990-01-01

    Two trials were performed to evaluate the efficacy of prostaglandins administered via the vulvomucosal route at one-half the recommended dosage in comparison to prostaglandins injected intramuscularly (IM) at the standard dosage. In trial 1, sows on three commercial swine farms were given prostaglandin F2α at a dosage of 10 mg IM (n = 110) or 5 mg prostaglandin F2α using a vulvomucosal injection (n = 94). The numbers of sows farrowing within 36 h postinjection were 92 (84%) and 83 (88%), respectively. In trial 2, sows on four commercial swine operations were induced to farrow by means of one of three treatments: cloprostenol 175 μg IM (n = 71); cloprostenol 87.5 μg vulvomucosally (n = 57); or prostaglandin F2α 5 mg vulvomucosally (n = 96). The numbers of sows farrowing within 36 h postinduction were 69 (97%), 53 (93%), and 91 (94%), respectively. Vulvomucosal injections of prostaglandin F2α and cloprostenol at one-half the dosage appeared to be as effective as intramuscular injections of prostaglandin F2α and cloprostenol at the recommended level. There were fewer sows demonstrating restless behavior following the injection of lower dosages of prostaglandin F2α vulvomucosally, compared to sows given the recommended dosage of prostaglandin F2α IM. PMID:17423605

  17. Negative feedback between prostaglandin and alpha- and beta-chemokine synthesis in human microglial cells and astrocytes.

    PubMed

    Janabi, N; Hau, I; Tardieu, M

    1999-02-01

    The understanding of immune surveillance and inflammation regulation in cerebral tissue is essential in the therapy of neuroimmunological disorders. We demonstrate here that primary human glial cells were able to produce alpha- and beta-chemokines (IL-8 > growth related protein alpha (GROalpha) > RANTES > microphage inflammatory protein (MIP)-1alpha and MIP-1beta) in parallel to PGs (PGE2 and PGF2alpha) after proinflammatory cytokine stimulation: TNF-alpha + IL-1beta induced all except RANTES, which was induced by TNF-alpha + IFN-gamma. Purified cultures of astrocytes and microglia were also induced by the same combination of cytokines, to produce all these mediators except MIP-1alpha and MIP-1beta, which were produced predominantly by astrocytes. The inhibition of PG production by indomethacin led to a 37-60% increase in RANTES, MIP-1alpha, and MIP-1beta but not in GROalpha and IL-8 secretion. In contrast, inhibition of IL-8 and GRO activities using neutralizing Abs resulted in a specific 6-fold increase in PGE2 but not in PGF2alpha production by stimulated microglial cells and astrocytes, whereas Abs to beta-chemokines had no effect. Thus, the production of PGs in human glial cells down-regulates their beta-chemokine secretion, whereas alpha-chemokine production in these cells controls PG secretion level. These data suggest that under inflammatory conditions, the intraparenchymal production of PGs could control chemotactic gradient of beta-chemokines for an appropriate effector cell recruitment or activation. Conversely, the elevated intracerebral alpha-chemokine levels could reduce PG secretion, preventing the exacerbation of inflammation and neurotoxicity. PMID:9973432

  18. Metabolism of vitamin D3 in human osteoblasts: evidence for autocrine and paracrine activities of 1 alpha,25-dihydroxyvitamin D3.

    PubMed

    Atkins, Gerald J; Anderson, Paul H; Findlay, David M; Welldon, Katie J; Vincent, Cristina; Zannettino, Andrew C W; O'Loughlin, Peter D; Morris, Howard A

    2007-06-01

    Circulating 1 alpha,25-dihydroxyvitamin D(3) (1,25D) derives from renal conversion of 25-hydroxyvitamin D(3) (25D), by the 25D 1 alpha-hydroxylase (CYP27B1). Blood 25D levels, but not 1,25D levels, are the best indicator of vitamin D status and predict fracture risk in the elderly. We examined the extent to which osteoblasts can metabolize 25D. Well-characterized human primary osteoblasts and osteosarcoma (OS) cell lines were examined for the expression and regulation of genes associated with vitamin D metabolism, using real-time PCR. Primary osteoblasts and OS cell lines were found to express CYP27B1 mRNA and secreted detectable 1,25D in response to 25D. Of the OS cell lines tested, HOS expressed the most CYP27B1 mRNA and secreted the highest levels of 1,25D. All osteoblastic cells examined up-regulated expression of the catabolic regulator of 1,25D, the 25-hydroxyvitamin D-24-hydroxylase (CYP24), when incubated with either 1,25D or 25D. Exposure to physiological levels of 25D resulted in up-regulated transcription of the 1,25D responsive genes, osteocalcin (OCN), osteopontin (OPN) and RANKL. Specific knockdown of CYP27B1 in HOS cells using siRNA resulted in up to 80% reduction in both 1,25D secretion and the transcription of OCN and CYP24, strongly implying that the 25D effect in osteoblasts is preceded by conversion to 1,25D. Incubation with 25D, like 1,25D, inhibited primary osteoblast proliferation and promoted in vitro mineralization. Finally, we detected expression by osteoblasts of receptors for vitamin D binding protein (DBP), cubilin and megalin, suggesting that osteoblasts are able to internalize DBP-25D complexes in vivo. Together, our results suggest that autocrine, and perhaps paracrine, pathways of vitamin D(3) metabolism may regulate key osteoblast functions independently of circulating, kidney derived 1,25D. Our results are therefore consistent with the reported benefits of mai