scholarly journals Expression and localization of cyclooxygenase isoforms and cytosolic phospholipase A2 in anti-Thy-1 glomerulonephritis.

1998 ◽  
Vol 9 (3) ◽  
pp. 408-416 ◽  
Author(s):  
S Hirose ◽  
T Yamamoto ◽  
L Feng ◽  
E Yaoita ◽  
K Kawasaki ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mrna Expression ◽  
Cell Injury ◽  
Mesangial Cell ◽  
Cytosolic Phospholipase ◽  
Glomerular Epithelial Cells ◽  
Injury Model ◽  
Cox 2 ◽  
Cyclooxygenase Isoforms ◽  
Cox 1

Glomerular expression of the major rate-limiting enzymes for prostanoid synthesis, cyclooxygenase isoforms (COX-1 and COX-2) and cytosolic phospholipase A2 (cPLA2), was investigated in anti-Thy-1 nephritis in rats. Ribonuclease protection assay demonstrated minimal COX-1 mRNA expression in glomeruli of control rat kidneys and a gradual increase of expression from day 1 to day 10 after administration of monoclonal anti-rat Thy-1 antibody. On the other hand, COX-2 mRNA expression, also minimal in the normal glomeruli, was enhanced in a biphasic pattern with two peaks at 1 h and day 10. Expression of cPLA2 mRNA, which was undetectable in normal glomeruli, was induced on day 1 and increased gradually in a pattern similar to that of COX-1 mRNA expression. Immunofluorescence microscopy, using antibodies against COX isoforms, showed that both COX-1 and COX-2 were negligible or faintly detectable in the glomeruli of control rat kidneys. In contrast, the immunofluorescence for COX-1 was intensified on days 4 and 10 along the glomerular capillary walls probably in glomerular epithelial and/or endothelial cells, whereas COX-2 staining was exclusively enhanced in the glomerular epithelial cells at 1 h and day 10 during the course of anti-Thy-1 nephritis. These findings indicate that prostanoids generated through induction of COX-1, COX-2, and cPLA2 are implicated in the mediation of the mesangial cell injury model. In particular, the upregulation of COX-2 expression in glomerular epithelial cells in the selective mesangial cell injury model suggests an intercellular interaction between mesangial cells, and glomerular epithelial cells.

scholarly journals Differential expression of cyclooxygenase 1 and cyclooxygenase 2 in the bovine oviduct

2006 ◽  
Vol 191 (1) ◽  
pp. 263-274 ◽  
Author(s):  
Simone Odau ◽  
Christoph Gabler ◽  
Christoph Holder ◽  
Ralf Einspanier
Keyword(s):  
Mrna Expression ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Cellular Level ◽  
Differential Distribution ◽  
Cyclooxygenase 1 ◽  
Epithelial Cell Layer ◽  
Cox 2 ◽  
Cycle Dependent ◽  
Cox 1

The aim of the present study was to investigate the enzymes for the local prostaglandin (PG) biosynthesis present in the bovine oviduct during the estrous cycle to influence early reproductive events. Bovine oviducts were classified into four phases: pre-ovulatory, post-ovulatory, early-to-mid luteal, and late luteal phase, subdivided further into ipsi- or contralateral site and separated into ampulla or isthmus. Oviductal cells were gained by flushing the oviductal regions. Quantitative real-time reverse transcriptase-PCR was performed for the secretory and cytosolic phospholipases A2 (sPLA2IB, cPLA2α, and cPLA2β) and cyclooxygenases (COX-1 and COX-2) as the first step enzymes of PG synthesis. COX-1 and cPLA2β showed significant highest mRNA expression around and before ovulation compared with the luteal phase respectively. sPLA2IB and cPLA2α mRNA expression was unregulated during the estrous cycle. Regional differences in mRNA content were found for sPLA2IB with higher mRNA expression in the ampulla than in the isthmus. Western blot analysis revealed the highest COX-1 protein content in the early-to-mid luteal phase. Immunohistochemistry demonstrated that COX-1 was localized in epithelial and smooth muscle cells, whereas COX-2 was only localized in epithelial cells. COX-2 showed a differential distribution within the epithelial cell layer suggesting a regulation on a cellular level, although the COX-2 mRNA and protein amounts did not vary throughout the estrous cycle. A COX activity assay of oviductal cells revealed that COX activity originated predominantly from COX-1 than from COX-2. Treatment of primary oviductal cells with 10 pg/ml 17β-estradiol or 10 ng/ml progesterone resulted in a higher expression of COX-2 and cPLA2α, but not of the other enzymes. The expression pattern of these enzymes suggests that an estrous-cycle dependent and region-specific PG synthesis in the bovine oviduct may be required for a successful reproduction.

scholarly journals Role of cyclooxygenase isoforms in prostacyclin biosynthesis and murine prehepatic portal hypertension

2008 ◽  
Vol 295 (5) ◽  
pp. G953-G964 ◽  
Author(s):  
N. J. Skill ◽  
N. G. Theodorakis ◽  
Y. N. Wang ◽  
J. M. Wu ◽  
E. M. Redmond ◽  
...  
Keyword(s):  
Portal Hypertension ◽  
The United States ◽  
Portal Vein Ligation ◽  
Wild Type ◽  
Sham Surgery ◽  
Cox 2 ◽  
Hemodynamic Measurements ◽  
Cyclooxygenase Isoforms ◽  
Cox 1

Portal hypertension (PHT) is a common complication of liver cirrhosis and significantly increases morbidity and mortality. Abrogation of PHT using NSAIDs has demonstrated that prostacyclin (PGI2), a direct downstream metabolic product of cyclooxygenase (COX) activity, is an important mediator in the development of experimental and clinical PHT. However, the role of COX isoforms in PGI2 biosynthesis and PHT is not fully understood. Prehepatic PHT was induced by portal vein ligation (PVL) in wild-type, COX-1−/−, and COX-2−/− mice treated with and without COX-2 (NS398) or COX-1 (SC560) inhibitors. Hemodynamic measurements and PGI2 biosynthesis were determined 1–7 days after PVL or sham surgery. Gene deletion or pharmacological inhibition of COX-1 or COX-2 attenuated but did not ameliorate PGI2 biosynthesis after PVL or prevent PHT. In contrast, treatment of COX-1−/− mice with NS398 or COX-2−/− mice with SC560 restricted PGI2 biosynthesis and abrogated the development of PHT following PVL. In conclusion, either COX-1 or COX-2 can mediate elevated PGI2 biosynthesis and the development of experimental prehepatic PHT. Consequently, PGI2 rather then COX-selective drugs are indicated in the treatment of PHT. Identification of additional target sites downstream of COX may benefit the >27,000 patients whom die annually from cirrhosis in the United States alone.

Prostaglandin endoperoxide synthase: why two isoforms?

1996 ◽  
Vol 270 (3) ◽  
pp. G393-G400 ◽  
Author(s):  
C. S. Williams ◽  
R. N. DuBois
Keyword(s):  
Epithelial Cells ◽  
Cardiac Fibrosis ◽  
Intestinal Epithelial Cells ◽  
Renal Dysplasia ◽  
Intestinal Epithelial ◽  
Phenotypic Changes ◽  
Prostaglandin Endoperoxide ◽  
Prostaglandin Endoperoxide Synthase ◽  
Cox 2 ◽  
Cox 1

Prostaglandin endoperoxide synthase-1 [prostaglandin G/H synthase-1 (PGHS-1)] and PGHS-2 are key enzymes in the conversion of arachidonic acid to prostaglandins and other eicosanoids. We refer to these isoforms as cyclooxygenase-1 (COX-1) and COX-2 in this review. This brief review focuses on recent developments in the study of these enzymes. Alterations in the expression levels of COX-2 result in distinct phenotypic changes in intestinal epithelial cells. Overexpression of COX-2 in intestinal epithelial cells results in increased adhesion to extracellular matrix proteins and inhibition of apoptosis. Disruption of the COX-2 gene in mice results in renal dysplasia, cardiac fibrosis, and defects in the ovary. Interestingly, disruption of the COX-1 gene results in distinct phenotypic changes different from those observed for COX-2. COX-1 null mice survive well, have no gastric pathology, and show less indomethacin-induced gastric ulceration than wild-type mice. These two closely related enzymes must have distinct functions in the organisms, since lack of their expression causes distinct phenotypic changes for each respective isoform.

scholarly journals Expression of cyclo-oxygenase types-1 and -2 in human fetal membranes throughout pregnancy

1999 ◽  
Vol 22 (2) ◽  
pp. 125-130 ◽  
Author(s):  
D Slater ◽  
W Dennes ◽  
R Sawdy ◽  
V Allport ◽  
P Bennett
Keyword(s):  
Mrna Expression ◽  
Gestational Age ◽  
Prostaglandin Synthesis ◽  
Fetal Membranes ◽  
Activity Levels ◽  
Third Trimester ◽  
Human Amnion ◽  
Human Labour ◽  
Cox 2 ◽  
Cox 1

Human labour is associated with increased prostaglandin synthesis within the fetal membranes. We have studied the expression of the two isoforms of the central prostaglandin synthetic enzyme, cyclo-oxygenase (COX-1 and COX-2), in human fetal membranes throughout pregnancy, at mRNA, protein and activity levels. COX-1 mRNA expression was low in human amnion and chorion-decidua and did not change with gestational age. COX-2 mRNA expression in fetal membranes increased with gestational age, with significant up-regulation prior to the onset of labour and in association with labour. Protein concentrations of COX-1 did not change, whilst concentrations of COX-2 increased from the first to the third trimester. COX activity increased with gestational age and in association with labour, although prostaglandin production in fetal membranes collected after labour was reduced, suggesting reduced substrate supply. These data suggest that it is up-regulation of COX-2, rather than of COX-1, which mediates increased prostaglandin synthesis within the fetal membranes at term. Much of the increase in COX-2 expression precedes the onset of labour, suggesting that it is a cause, rather than a consequence, of labour.

Cytosolic phospholipase A2-α associates with plasma membrane, endoplasmic reticulum and nuclear membrane in glomerular epithelial cells

2000 ◽  
Vol 353 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Jianhong LIU ◽  
Tomoko TAKANO ◽  
Joan PAPILLON ◽  
Abdelkrim KHADIR ◽  
Andrey V. CYBULSKY
Keyword(s):  
Endoplasmic Reticulum ◽  
Arachidonic Acid ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Phospholipase A2 ◽  
Cytosolic Phospholipase A2 ◽  
Membrane Association ◽  
Cytosolic Phospholipase ◽  
Glomerular Epithelial Cells ◽  
In Cells

Eicosanoids mediate complement-dependent glomerular epithelial injury in experimental membranous nephropathy. The release of arachidonic acid from phospholipids by cytosolic phospholipase A2 (cPLA2) is the rate-limiting step in eicosanoid synthesis. The present study examines the association of cPLA2 with membranes of organelles. Glomerular epithelial cells were disrupted by homogenization in Ca2+-free buffer; organelles were separated by gradient centrifugation. The distribution of cPLA2 and organelles was analysed by immunoblotting with antibodies against cPLA2 and organelle markers, or by enzyme assay. In cells incubated with or without the Ca2+ ionophore ionomycin plus PMA, cPLA2 co-localized with plasma membrane, endoplasmic reticulum and nuclei, but not with mitochondria or Golgi. A greater amount of cPLA2 was associated with membranes in stimulated cells, but membrane-associated cPLA2 was readily detectable under resting conditions. The pattern of association of cPLA2 with membrane in cells treated with antibody and complement was similar to that in cells stimulated with ionomycin plus PMA; however, complement did not enhance the membrane association of cPLA2 protein. To determine the functional role of membrane association of cPLA2, phospholipids were labelled with [3H]arachidonic acid. Cells were then incubated with or without antibody and complement and were fractionated. Complement induced a loss of radioactivity from the plasma membrane, endoplasmic reticulum and nuclei, but not from the mitochondrial fraction. Thus the release of arachidonic acid by cPLA2 is due to the hydrolysis of phospholipids at multiple subcellular membrane sites, including the endoplasmic reticulum, plasma membrane and nucleus.

Prostaglandins that increase renin production in response to ACE inhibition are not derived from cyclooxygenase-1

2002 ◽  
Vol 283 (3) ◽  
pp. R638-R646 ◽  
Author(s):  
Hui-Fang Cheng ◽  
Sue-Wan Wang ◽  
Ming-Zhi Zhang ◽  
James A. McKanna ◽  
Richard Breyer ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Enzyme Inhibitor ◽  
Plasma Renin ◽  
Immunohistochemical Analysis ◽  
Renin Activity ◽  
Prostaglandin E ◽  
Receptor Subtype ◽  
Renin Mrna ◽  
Cox 2 ◽  
Cox 1

It is well known that nonselective, nonsteroidal anti-inflammatory drugs inhibit renal renin production. Our previous studies indicated that angiotensin-converting enzyme inhibitor (ACEI)-mediated renin increases were absent in rats treated with a cyclooxygenase (COX)-2-selective inhibitor and in COX-2 −/− mice. The current study examined further whether COX-1 is also involved in mediating ACEI-induced renin production. Because renin increases are mediated by cAMP, we also examined whether increased renin is mediated by the prostaglandin E2 receptor EP2 subtype, which is coupled to Gs and increases cAMP. Therefore, we investigated if genetic deletion of COX-1 or EP2 prevents increased ACEI-induced renin expression. Age- and gender-matched wild-type (+/+) and homozygous null mice (−/−) were administered captopril for 7 days, and plasma and renal renin levels and renal renin mRNA expression were measured. There were no significant differences in the basal level of renal renin activity from plasma or renal tissue in COX-1 +/+ and −/− mice. Captopril administration increased renin equally [plasma renin activity (PRA): +/+ 9.3 ± 2.2 vs. 50.1 ± 10.9; −/− 13.7 ± 1.5 vs. 43.9 ± 6.6 ng ANG I · ml−1 · h−1; renal renin concentration: +/+ 11.8 ± 1.7 vs. 35.3 ± 3.9; −/− 13.0 ± 3.0 vs. 27.8 ± 2.7 ng ANG I · mg protein−1 · h−1; n = 6; P < 0.05 with or without captopril]. ACEI also increased renin mRNA expression (+/+ 2.4 ± 0.2; −/− 2.1 ± 0.2 fold control; n = 6–10; P < 0.05). Captopril led to similar increases in EP2 −/− compared with +/+. The COX-2 inhibitor SC-58236 blocked ACEI-induced elevation in renal renin concentration in EP2 null mice (+/+ 24.7 ± 1.7 vs. 9.8 ± 0.4; −/− 21.1 ± 3.2 vs. 9.3 ± 0.4 ng ANG I · mg protein−1 · h−1; n = 5) as well as in COX-1 −/− mice (SC-58236-treated PRA: +/+ 7.3 ± 0.6; −/− 8.0 ± 0.9 ng ANG I · ml−1 · h−1; renal renin: +/+ 9.1 ± 0.9; −/− 9.6 ± 0.5 ng ANG I · mg protein−1 · h−1; n = 6–7; P < 0.05 compared with no treatment). Immunohistochemical analysis of renin expression confirmed the above results. This study provides definitive evidence that metabolites of COX-2 rather than COX-1 mediate ACEI-induced renin increases. The persistent response in EP2 nulls suggests involvement of prostaglandin E2 receptor subtype 4 and/or prostacyclin receptor (IP).

scholarly journals Effects of Nonsteroidal Anti-Inflammatory Drugs onHelicobacter pylori-Infected Gastric Mucosae of Mice: Apoptosis, Cell Proliferation, and Inflammatory Activity

2001 ◽  
Vol 69 (8) ◽  
pp. 5056-5063 ◽  
Author(s):  
Tae Il Kim ◽  
Yong Chan Lee ◽  
Kwang Hyoung Lee ◽  
Jae Ho Han ◽  
Chae Yoon Chon ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Inflammatory Activity ◽  
Prostaglandin E ◽  
Gastric Epithelial Cells ◽  
Inflammatory Drugs ◽  
Cox 2 ◽  
H Pylori ◽  
Cox 1

ABSTRACT Helicobacter pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) are two well-known important causative factors of gastric damage. While H. pylori increases apoptosis and the proliferation of gastric epithelial cells and is an important factor in peptic ulcer and gastric cancer, NSAIDs induce cell apoptosis and have antineoplastic effects. We investigated the effects of NSAIDs (a nonselective cyclooxygenase [COX] inhibitor [indomethacin] and a selective COX-2 inhibitor [NS-398]) on the apoptosis and proliferation of gastric epithelial cells and gastric inflammation inH. pylori-infected mice. C57BL/6 mice were sacrificed 8 weeks after H. pylori SS1 inoculation. Indomethacin (2 mg/kg) or NS-398 (10 mg/kg) was administered subcutaneously once daily for 10 days before sacrifice. The following were assessed: gastric inflammatory activity, gastric COX protein expression by Western blotting; gastric prostaglandin E2 levels by enzyme immunoassay, apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and cell proliferation by Ki67 immunostaining. Compared to the controls, H. pylori infection and/or NSAID treatment increased COX-1 and COX-2 protein expression. Gastric prostaglandin E2 levels, apoptotic index, cell proliferation index, neutrophil activity, and the degree of chronic inflammation were all increased by H. pylori infection, and these effects were significantly decreased by indomethacin treatment. However, NS-398 treatment after H. pylori infection did not induce a significant reduction, although it did result in a tendency to decrease. These results show that NSAIDs can reverse the increased apoptosis and proliferation of epithelial cells and inflammatory activity in the stomachs of H. pylori-infected mice and that, like COX-2 activation, COX-1 induction contributes to the change of gastric mucosal cell turnover and inflammation induced by H. pylori infection.

scholarly journals A monoclonal antibody (1F3) to human glomerular epithelial cells: A new marker for renal epithelial cell injury.

1996 ◽  
Vol 9 (2) ◽  
pp. 222-228
Author(s):  
Yuji Morimoto ◽  
Shoji Kagami ◽  
Kaname Okada ◽  
Kouji Yasutomo ◽  
Takashi Kuhara ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Injury ◽  
Renal Epithelial Cell ◽  
Glomerular Epithelial Cells ◽  
Epithelial Cell Injury

scholarly journals Ellagic acid inhibits lipopolysaccharide-induced expression of enzymes involved in the synthesis of prostaglandin E2 in human monocytes

2009 ◽  
Vol 103 (8) ◽  
pp. 1102-1109 ◽  
Author(s):  
Sofia Karlsson ◽  
Eewa Nånberg ◽  
Christina Fjaeraa ◽  
Jonny Wijkander
Keyword(s):  
Ellagic Acid ◽  
Inhibitory Effect ◽  
Ionophore A23187 ◽  
Human Monocytes ◽  
Cytosolic Phospholipase ◽  
Natural Polyphenol ◽  
The Subject ◽  
Cox 2 ◽  
Cancer And Inflammation ◽  
Cox 1

Ellagic acid, a natural polyphenol found in certain fruits, nuts and vegetables, has in recent years been the subject of intense research within the fields of cancer and inflammation. Pain, fever and swelling, all typical symptoms of inflammation, are ascribed to elevated levels of PGE2. In the present study, we have investigated the effects of ellagic acid on PGE2 release and on prostaglandin-synthesising enzymes in human monocytes. Ellagic acid was found to inhibit Ca ionophore A23187-, phorbol myristate acetate- and opsonised zymosan-induced release of PGE2 from monocytes pre-treated with the inflammatory agent lipopolysaccharide. Ellagic acid suppressed the lipopolysaccharide-induced increase in protein expression of cyclo-oxygenase-2 (COX-2), microsomal PGE synthase-1 (mPGEs-1) and cytosolic phospholipase A2α (cPLA2α), while it had no effect on the constitutively expressed COX-1 protein. Ellagic acid had no apparent inhibitory effect on these enzymes when the activities were determined in cell-free assays. We conclude that the inhibitory effect of ellagic acid on PGE2 release from monocytes is due to a suppressed expression of COX-2, mPGEs-1 and cPLA2α, rather than a direct effect on the activities of these enzymes.

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