Selectivity of cyclooxygenase isoform activity and prostanoid production in normal and diseased Han:SPRD-cy rat kidneys

Renal prostanoids are important regulators of normal renal function and maintenance of renal homeostasis. In diseased kidneys, renal cylooxygenase (COX) expression and prostanoid formation are altered. With the use of the Han:Sprague-Dawley- cy rat, the aim of this study was to determine the relative contribution of renal COX isoforms (protein, gene expression, and activity) on renal prostanoid production [thromboxane B2 (TXB2, stable metabolite of TXA2), prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1α (6-keto-PGF1α, stable metabolite of PGI2)] in normal and diseased kidneys. In diseased kidneys, COX-1-immunoreactive protein and mRNA levels were higher and COX-2 levels were lower compared with normal kidneys. In contrast, COX activities were higher in diseased compared with normal kidneys for both COX-1 [0.05 ± 0.02 vs. 0.45 ± 0.11 ng prostanoids·min−1·mg protein−1 ( P < 0.001)] and COX-2 [0.64 ± 0.10 vs. 2.32 ± 0.22 ng prostanoids·min−1·mg protein−1 ( P < 0.001)]. As the relative difference in activity was greater for COX-1, the ratio of COX-1/COX-2 was higher in diseased compared with normal kidneys, although the predominant activity was still due to the COX-2 isoform in both genotypes. Endogenous and steady-state in vitro levels of prostanoids were ∼2–10 times higher in diseased compared with normal kidneys. The differences between normal and diseased kidney prostanoids were in the order of TXB2 > 6-keto-PGF1α > PGE2, as determined by higher renal prostanoid levels and COX activity ratios of TXB2/6-keto-PGF1α, TXB2/PGE2, and 6-keto-PGF1α/PGE2. This specificity in both the COX isoform type and for the prostanoids produced has implications for normal and diseased kidneys in treatments involving selective inhibition of COX isoforms.

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Cyclooxygenase-2 plays a significant role in regulating the tone of the fetal lamb ductus arteriosus

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1999.276.3.r913 ◽

1999 ◽

Vol 276 (3) ◽

pp. R913-R921 ◽

Cited By ~ 13

Author(s):

Ronald I. Clyman ◽

Pierre Hardy ◽

Nahid Waleh ◽

Yao Qi Chen ◽

Françoise Mauray ◽

...

Keyword(s):

Significant Role ◽

Ductus Arteriosus ◽

Late Gestation ◽

Relative Contribution ◽

Cox Inhibitor ◽

Fetal Lamb ◽

Cox 2 ◽

Cox 2 Inhibitors ◽

Cox 1

Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents but have adverse effects on the fetal ductus arteriosus. We hypothesized that COX-2 inhibitors may not affect the ductus if the predominant COX isoform is COX-1. To examine this hypothesis, we used ductus arteriosus obtained from late-gestation fetal lambs. In contrast to our hypothesis, fetal lamb ductus arteriosus expressed both COX-1- and COX-2-immunoreactive protein (by Western analysis). Although COX-1 was found in both endothelial and smooth muscle cells, COX-2 was found only in the endothelial cells lining the ductus lumen (by immunohistochemistry). The relative contribution of COX-1 and COX-2 to PGE2 synthesis was consistent with the immunohistochemical results: in the intact ductus, PGE2 formation was catalyzed by both COX-1 and COX-2 in equivalent proportions; in the endothelium-denuded ductus, COX-2 no longer played a significant role in PGE2 synthesis. NS-398, a selective inhibitor of COX-2, was 66% as effective as the selective COX-1 inhibitor valeryl salicylate and the nonselective COX inhibitor indomethacin in causing contraction of the ductus in vitro. At this time, caution should be used when recommending COX-2 inhibitors for use in pregnant women.

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Intraluteal regulation of prostaglandin F2α-induced prostaglandin biosynthesis in pseudopregnant rabbits

Reproduction ◽

10.1530/rep-06-0107 ◽

2007 ◽

Vol 133 (5) ◽

pp. 1005-1016 ◽

Cited By ~ 26

Author(s):

M Zerani ◽

C Dall’Aglio ◽

M Maranesi ◽

A Gobbetti ◽

G Brecchia ◽

...

Keyword(s):

Prostaglandin F2α ◽

Enzymatic Activities ◽

Synthesis Rate ◽

Corpora Lutea ◽

Positive Staining ◽

Mrna Levels ◽

Cox 2 ◽

Pg E2 ◽

Cox 1

The objective of the present study was to investigate in rabbit corpora lutea (CL), at both the cellular and molecular level, intraluteal cyclooxygenase (COX)-1, COX-2 and prostaglandin (PG) E2-9-ketoreductase (PGE2-9-K) enzymatic activities as well asin vitroPGE2 and PGF2α synthesis following PGF2α treatment at either early- (day-4) or mid-luteal (day-9) stage of pseudopregnancy. By immunohistochemistry, positive staining for COX-2 was localized in luteal and endothelial cells of stromal arteries at both the stages. In CL of both stages, basal COX-2 mRNA levels were poorly expressed, but rose (P< 0.01) 4- to 10-fold 1.5–6 h after treatment and then gradually decreased within 24 h. Compared to mid-stage, day-4 CL had lower (P< 0.01) COX-2 and PGE2-9-K basal activities, and PGF2α synthesis rate, but higher (P< 0.01) PGE2 production. Independent of luteal stage, PGF2α treatment did not affect COX-1 activity. In day-4 CL, PGF2α induced an increase (P< 0.01) in both COX-2 activity and PGF2α synthesis, whereas that of PGE2 remained unchanged. In day-9 CL, PGF2α up-regulated (P< 0.01) both COX-2 and PGE-9-K activities, and PGF2α production, but decreased (P< 0.01) PGE2 synthesis. All changes in gene expression and enzymatic activities occurred within 1.5 h after PGF2α challenge and were more marked in day-9 CL. Our data suggest that PGF2α directs intraluteal PG biosynthesis in mature CL, by affecting the CL biosynthetic machinery to increase the PGF2α synthesis in an auto-amplifying manner, with the activation of COX-2 and PGE-9-K; this may partly explain their differentially, age-dependent, luteolytic capacity to exogenous PGF2α in rabbits.

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Are there attacking points in the eicosanoid cascade for chemotherapeutic options in benign meningiomas?

Neurosurgical FOCUS ◽

10.3171/foc-07/10/e8 ◽

2007 ◽

Vol 23 (4) ◽

pp. E8 ◽

Cited By ~ 4

Author(s):

Christina Pfister ◽

Rainer Ritz ◽

Heike Pfrommer ◽

Antje Bornemann ◽

Marcos S. Tatagiba ◽

...

Keyword(s):

World Health ◽

Pcr Analysis ◽

Prostaglandin E ◽

Tissue Samples ◽

Human Cortex ◽

Normal Human ◽

Cox 2 ◽

Cox 1

Object The current treatment for recurrent or malignant meningiomas with adjuvant therapies has not been satisfactory, and there is an intense interest in evaluating new molecular markers to act as therapeutic targets. Enzymes of the arachidonic acid (AA) cascade such as cyclooxygenase (COX)–2 or 5-lipoxygenase (5-LO) are upregulated in a number of epithelial tumors, but to date there are hardly any data about the expression of these markers in meningiomas. To find possible targets for chemotherapeutic intervention, the authors evaluated the expression of AA derivatives at different molecular levels in meningiomas. Methods One hundred and twenty-four meningioma surgical specimens and normal human cortical tissue samples were immunohistochemically and cytochemically stained for COX-2, COX-1, 5-LO, and prostaglandin E receptor 4 (PTGER4). In addition, Western blot and polymerase chain reaction (PCR) analyses were performed to detect the presence of eicosanoids in vivo and in vitro. Results Sixty (63%) of 95 benign meningiomas, 21 (88%) of 24 atypical meningiomas, all five malignant meningiomas, and all normal human cortex samples displayed high COX-2 immunoreactivity. All cultured specimens and IOMM-Lee cells stained positive for COX-2, COX-1, 5-LO, and PTGER4. The PCR analysis demonstrated no changes in eicosanoid expression among meningiomas of different World Health Organization grades and in normal human cortical and dura mater tissue. Conclusions Eicosanoid derivatives COX-1, COX-2, 5-LO, and PTGER4 enzymes show a high universal expression in meningiomas but are not upregulated in normal human cortex and dura tissue. This finding of the ubiquitous presence of these enzymes in meningiomas offers an excellent baseline for testing upcoming chemotherapeutic treatments.

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Role of prostaglandins in collecting duct-derived endothelin-1 regulation of blood pressure and water excretion

AJP Renal Physiology ◽

10.1152/ajprenal.00307.2007 ◽

2007 ◽

Vol 293 (6) ◽

pp. F1805-F1810 ◽

Cited By ~ 18

Author(s):

Yuqiang Ge ◽

Kevin A. Strait ◽

Peter K. Stricklett ◽

Tianxin Yang ◽

Donald E. Kohan

Keyword(s):

Blood Pressure ◽

Collecting Duct ◽

Urine Volume ◽

Mrna Levels ◽

Water Excretion ◽

Salt Loading ◽

Endothelin 1 ◽

Cox 2 ◽

Cox 1

Collecting duct (CD)-derived endothelin-1 (ET-1) exerts natriuretic, diuretic, and hypotensive effects. In vitro studies have implicated cyclooxygenase (COX) metabolites, and particularly PGE2, as important mediators of CD ET-1 effects. However, it is unknown whether PGE2 mediates CD-derived ET-1 actions in vivo. To test this, CD ET-1 knockout (KO) and control mice were studied. During normal salt and water intake, urinary PGE2 excretion was unexpectedly increased in CD ET-1 KO mice compared with controls. Salt loading markedly increased urinary PGE2 excretion in both groups of mice; however, the levels remained relatively higher in KO animals. Acutely isolated inner medullary collecting duct (IMCD) from KO mice also had increased PGE2 production. The increased IMCD PGE2 was COX-2 dependent, since NS-398 blocked all PGE2 production. However, increased CD ET-1 KO COX-2 protein or mRNA could not be detected in inner medulla or IMCD, respectively. Inner medullary COX-1 mRNA and protein levels and IMCD COX-1 mRNA levels were unaffected by Na intake or CD ET-1 KO. KO mice on a normal or high-Na diet had elevated blood pressure compared with controls; this difference was not altered by indomethacin or NS-398 treatment. However, indomethacin or NS-398 did increase urine osmolality and reduce urine volume in KO, but not control, animals. In summary, IMCD COX-2-dependent PGE2 production is increased in CD ET-1 KO mice, indicating that CD-derived ET-1 is not a primary regulator of IMCD PGE2. Furthermore, the increased PGE2 in CD ET-1 KO mice partly compensates for loss of ET-1 with respect to maintaining urinary water excretion, but not in blood pressure control.

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Differential contribution of COX-1 and COX-2 derived prostanoids to cortical spreading depression—Evoked cerebral oligemia

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x16650217 ◽

2016 ◽

Vol 37 (3) ◽

pp. 1060-1068 ◽

Cited By ~ 10

Author(s):

Helaine Gariepy ◽

Jun Zhao ◽

Dan Levy

Keyword(s):

Cortical Spreading Depression ◽

Spreading Depression ◽

Selective Inhibition ◽

Doppler Flowmetry ◽

Relative Contribution ◽

Cox Inhibitor ◽

Cox 2 ◽

Synthase Inhibitor ◽

Later Phase ◽

Cox 1

Cortical spreading depression (CSD) is considered a significant phenomenon for human neurological conditions and one of its key signatures is the development of persistent cortical oligemia. The factors underlying this reduction in cerebral blood flow (CBF) remain incompletely understood but may involve locally elaborated vasoconstricting eicosanoids. We employed laser Doppler flowmetry in urethane-anesthetized rats, together with a local pharmacological blockade approach, to test the relative contribution of cyclooxygenase (COX)-derived prostanoids to the oligemic response following CSD. Administration of the non-selective COX inhibitor naproxen completely inhibited the oligemic response. Selective inhibition of COX-1 with SC-560 preferentially reduced the early reduction in CBF while selective COX-2 inhibition with NS-398 affected only the later response. Blocking the action of thromboxane A2 (TXA2), using the selective thromboxane synthase inhibitor ozagrel, reduced only the initial CBF decrease, while inhibition of prostaglandin F2alpha action, using the selective FP receptor antagonist AL-8810, blocked the later phase of the oligemia. Our results suggest that the long-lasting oligemia following CSD consists of at least two distinct temporal phases, mediated by preferential actions of COX-1- and COX-2-derived prostanoids: an initial phase mediated by COX-1 that involves TXA2 followed by a later phase, mediated by COX-2 and PGF2alpha.

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PGE2 reduces arachidonic acid release in murine podocytes: evidence for an autocrine feedback loop

AJP Cell Physiology ◽

10.1152/ajpcell.00024.2002 ◽

2003 ◽

Vol 284 (2) ◽

pp. C302-C309 ◽

Cited By ~ 15

Author(s):

Lyne I. Lemieux ◽

Sherine S. Rahal ◽

Chris R. J. Kennedy

Keyword(s):

Arachidonic Acid ◽

Cell Line ◽

Selective Inhibition ◽

Renal Diseases ◽

Prostaglandin E ◽

Dependent Manner ◽

Glomerular Function ◽

Cox 2 ◽

Regulatory Loop ◽

Cox 1

Increased glomerular prostaglandin E2 (PGE2) production is associated with the progression of diseases such as membranous nephropathy, nephrotic syndrome, and anti-Thy1 nephritis. We investigated the signaling pathways that regulate the synthesis and actions of PGE2 in glomerular podocytes. To study its actions, we assessed the ability of PGE2 to regulate the production of its own precursor, arachidonic acid (AA), in a mouse podocyte cell line. PGE2 dose-dependently reduced phorbol ester (PMA)-mediated AA release. Inhibition of PMA-stimulated AA release by PGE2 was found to be cAMP/PKA-dependent, because PGE2 significantly increased levels of this second messenger, whereas the inhibitory actions of PGE2 were reversed by PKA inhibition and reproduced by the cAMP-elevating agents forskolin and IBMX. PGE2 synthesis in this podocyte cell line increased fourfold at 60 min in response to PMA, coinciding with upregulation of cyclooxygenase (COX)-2 but not COX-1 levels. However, PGE2 synthesis was significantly reduced by COX-1-selective inhibition, yet to a lesser extent by COX-2-selective inhibition. Our findings suggest that PMA-stimulated PGE2 synthesis in mouse podocytes requires both basal COX-1 activity and induced COX-2 expression, and that PGE2 reduces PMA-stimulated AA release in a cAMP/PKA-dependent manner. Such an autocrine regulatory loop might have important consequences for podocyte and glomerular function in the context of renal diseases involving PGE2 synthesis.

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Cholera Toxin Induces a Shift from Inactive to Active Cyclooxygenase 2 in Alveolar Macrophages Activated by Mycobacterium bovis BCG

Infection and Immunity ◽

10.1128/iai.01031-12 ◽

2012 ◽

Vol 81 (1) ◽

pp. 373-380

Author(s):

Mari Kogiso ◽

Tsutomu Shinohara ◽

C. Kathleen Dorey ◽

Yoshimi Shibata

Keyword(s):

Cholera Toxin ◽

Mycobacterium Bovis ◽

Alveolar Macrophages ◽

Mucosal Vaccine ◽

Prostaglandin E ◽

Lung Cells ◽

Cox 2 ◽

Cox 1

Intranasal vaccination stimulates formation of cyclooxygenases (COX) and release of prostaglandin E2(PGE2) by lung cells, including alveolar macrophages. PGE2plays complex pro- or anti-inflammatory roles in facilitating mucosal immune responses, but the relative contributions of COX-1 and COX-2 remain unclear. Previously, we found thatMycobacterium bovisBCG, a human tuberculosis vaccine, stimulated increased release of PGE2by macrophages activatedin vitro; in contrast, intranasal BCG activated no PGE2release in the lungs, because COX-1 and COX-2 in alveolar macrophages were subcellularly dissociated from the nuclear envelope (NE) and catalytically inactive. This study tested the hypothesis that intranasal administration of BCG with cholera toxin (CT), a mucosal vaccine component, would shift the inactive, NE-dissociated COX-1/COX-2 to active, NE-associated forms. The results showed increased PGE2release in the lungs and NE-associated COX-2 in the majority of COX-2+macrophages. These COX-2+macrophages were the primary source of PGE2release in the lungs, since there was only slight enhancement of NE-associated COX-1 and there was no change in COX-1/COX-2 levels in alveolar epithelial cells following treatment with CT and/or BCG. To further understand the effect of CT, we investigated the timing of BCG versus CT administration forin vivoandin vitromacrophage activations. When CT followed BCG treatment, macrophagesin vitrohad elevated COX-2-mediated PGE2release, but macrophagesin vivoexhibited less activation of NE-associated COX-2. Our results indicate that inclusion of CT in the intranasal BCG vaccination enhances COX-2-mediated PGE2release by alveolar macrophages and further suggest that the effect of CTin vivois mediated by other lung cells.

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Up-regulation of cytosolic prostaglandin E synthase in fetal-membrane and amniotic prostaglandin E2 accumulation in labor

PLoS ONE ◽

10.1371/journal.pone.0250638 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0250638

Author(s):

Nanase Takahashi ◽

Toshiaki Okuno ◽

Hiroki Fujii ◽

Shintaro Makino ◽

Masaya Takahashi ◽

...

Keyword(s):

Amniotic Fluid ◽

Mrna Level ◽

Fetal Membrane ◽

Prostaglandin E ◽

Mrna Levels ◽

Prostaglandin E Synthase ◽

Detailed Mechanism ◽

Human Labor ◽

Cox 2 ◽

Cox 1

Prostaglandin E2 (PGE2) is known to have important roles in labor, but the detailed mechanism underlying the spontaneous human labor remains unknown. Here, we examined the involvement of prostaglandin biosynthetic enzymes and transporter in the accumulation of PGE2 in amniotic fluid in human labor. PGE2 and its metabolites were abundant in amniotic fluid in deliveries at term in labor (TLB), but not at term not in labor (TNL). In fetal-membrane Transwell assays, levels of PGE2 production in both maternal and fetal compartments were significantly higher in the TLB group than the TNL group. In fetal-membrane, the mRNA level of PTGES3, which encodes cytosolic prostaglandin E synthase (cPGES), was significantly higher in TLB than in TNL, but the mRNA levels of the other PGE2-synthase genes were not affected by labor. Moreover, the mRNA level of PTGS2, which encodes cyclooxygenase-2 (COX-2) in the amnion was significantly higher in TLB than in TNL. Western blot analyses revealed that the levels of COX-1 and COX-2 were comparable between the two groups, however, the level of cPGES was relatively higher in TLB than in TNL. COXs, cPGES, and prostaglandin transporter (SLCO2A1) proteins were all expressed in both chorionic trophoblasts and amniotic epithelium. These findings suggest that COXs, cPGES and SLCO2A1 contribute to PGE2 production from fetal-membrane in labor.

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Expression of enzymes involved in the synthesis of prostaglandin E2 in bovine in vitro-produced embryos

Zygote ◽

10.1017/s0967199410000596 ◽

2011 ◽

Vol 19 (3) ◽

pp. 277-283 ◽

Cited By ~ 13

Author(s):

Marie Saint-Dizier ◽

Bénédicte Grimard ◽

Catherine Guyader-Joly ◽

Patrice Humblot ◽

Andrew A. Ponter

Keyword(s):

Arachidonic Acid ◽

Prostaglandin E2 ◽

Limit Of Detection ◽

Developmental Competence ◽

Prostaglandin E ◽

Rt Pcr ◽

Sequential Transformation ◽

Cox 2 ◽

Cox 1

SummaryProstaglandin E2 (PGE2) may play a major role in embryo development and the establishment of pregnancy in cattle. The biosynthesis of PGE2 implies the sequential transformation of arachidonic acid to PGH2 by cyclooxygenases (COXs), then the conversion of PGH2 to PGE2 by prostaglandin E synthases (PGESs). Quantitative RT-PCR was used to examine the expression of COX-1, COX-2, microsomal PGES-1 (mPGES-1), microsomal PGES-2 (mPGES-2) and cytosolic PGES (cPGES) mRNAs in day 7 in vitro-produced (IVP) embryos from oocytes collected by ovum pick-up in Holstein heifers. Transcripts for COX-2 and mPGES-1 were detected in all embryos, whereas transcripts for COX-1 and mPGES-2 were not detected and cPGESs were at the limit of detection in 40% of embryos. Levels of COX-2 and mPGES-1 mRNAs were significantly higher in blastocysts and expanded blastocysts than in morulae and early blastocysts. Furthermore, excellent-quality embryos (grade 1) displayed higher levels of both COX-2 and mPGES-1 than did embryos of good and medium qualities (grades 2–3). Our results suggest that bovine IVP embryos at the morula and blastocyst stages use exclusively the COX-2/mPGES-1 pathway for PGE2 biosynthesis, and that PGE2 is potentially involved in blastocyst expansion and developmental competence.

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Expression of Enzymes Associated with Prostaglandin Synthesis in Equine Conceptuses

Animals ◽

10.3390/ani11041180 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1180

Author(s):

Sven Budik ◽

Ingrid Walter ◽

Marie-Christine Leitner ◽

Reinhard Ertl ◽

Christine Aurich

Keyword(s):

Enzyme Synthesis ◽

Prostaglandin E ◽

Rt Pcr ◽

Key Enzymes ◽

Disc Area ◽

Key Enzyme ◽

Cox 2 ◽

Endodermal Layer ◽

Cox 1

In the horse, mobility of the conceptus is required for maternal recognition of pregnancy depending on secretion of prostaglandins by the conceptus. The aim of this study was to determine the expression and localization of key enzymes of the different pathways leading to synthesis of prostaglandin E2 and F2α in the equine conceptus during the mobility phase. Enzyme expression was analyzed via quantitative RT-PCR in total RNA samples of equine conceptuses collected on days 10 (n = 5), 12 (n = 12), 14 (n = 5) and 16 (n = 7) from healthy mares. Relative abundance of cyclooxygenase (COX)-2 mRNA was higher (p < 0.05) than of COX-1 irrespective of conceptus age and for phospholipase A2 on day 16 in comparison to all other days (p < 0.01). Abundance of mRNA of cytosolic and microsomal prostaglandin E synthase (PGES) and of carbonyl reductase (CBR) 1 was not influenced by conceptus age. Immunohistochemically, COX-1, COX-2, as well as cytosolic and microsomal PGES were present in both the ectodermal and endodermal layer of the yolk sac wall. CBR-1 was restricted to periembryonic disc area. The localisation of the key enzymes explains the mechanism of embryo mobility. In vitro incubation of primary trophoblast cell cultures with oxytocin had no effect on key enzyme synthesis.

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