The JI
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     
 

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Clancy, R.
Right arrow Articles by Abramson, S. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Clancy, R.
Right arrow Articles by Abramson, S. B.
Right arrowPubmed/NCBI databases
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*NITRIC OXIDE
The Journal of Immunology, 2000, 165: 1582-1587.
Copyright © 2000 by The American Association of Immunologists

Nitric Oxide Synthase/COX Cross-Talk: Nitric Oxide Activates COX-1 But Inhibits COX-2-Derived Prostaglandin Production1

Robert Clancy2,*, Branko Varenika*, Weiqing Huang*, Les Ballou{dagger}, Mukundan Attur*, Ashok R. Amin* and Steven B. Abramson*

* Department of Rheumatology, Hospital for Joint Diseases and Division of Rheumatology, New York University School of Medicine, New York, NY 10003; and {dagger} Department of Veterans Affairs Medical Center and Departments of Medicine and Biochemistry, University of Tennessee, Memphis, TN 38163


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
It is recognized that there is molecular cross-talk between the inflammatory mediators NO and PGs that may regulate tissue homeostasis and contribute to pathophysiological processes. However, the literature is divided with respect to whether NO activates or inhibits PG production. In this study, we sought to determine whether conflicting observations could be accounted for by divergent effects of NO on the two cyclooxygenase (COX) isoforms. Exposure of resting macrophages to NO (30 µM) enhanced PGE2 release by 4.5-fold. This enhancement was inhibited by indomethacin but not by the COX-2 selective inhibitor NS398. To separate the activation of phospholipase A2 and COX, we performed experiments using fibroblasts derived from COX-1-deficient or COX-2-deficient mice. These cells exhibit increased basal PG production, which is due to a constitutively stimulated cytosolic phospholipase A2 and enhanced basal expression of the remaining COX isozyme. The exposure of COX- 2-deficient cells to exogenous NO (10 µM) resulted in a 2.4-fold increase of PGE2 release above controls. Further studies indicated that NO stimulated PGE2 release in COX-2-deficient cells, without altering COX-1 mRNA or protein expression. In contrast, NO inhibited COX-2-derived PGE2 production in both LPS-stimulated macrophages and COX-1 knockout cells. This inhibition was associated with both decreased expression and nitration of COX-2. Thus, these studies demonstrate divergent effects of NO on the COX isoforms. The regulation of PGE production by NO is therefore complex and will depend on the local environment in which these pleiotropic mediators are produced.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Nitric oxide synthase (NOS)3 and cyclooxygenase (COX) produce important mediators of tissue homeostasis and pathophysiological processes. The regulation of these enzymes and their capacity to participate in molecular cross-talk is an important focus of investigation. Both NOS and COX have constitutive and inducible isoforms which are encoded by two unique genes, located on different chromosomes (1, 2). COX-2 is the inducible form of the COX enzyme, the synthesis of which is triggered by those cytokines that also induce NOS-2, or inducible NOS (reviewed in Refs. 3 and 4). COX-1 is the constitutive isoform that is expressed by most human cells and tissues (5). COX-1 and COX-2 are 60% identical within a species (6) with the conservation of a tyrosine (Tyr385) located in the active site. Tyr385 contributes to enzyme activity; in addition, the tyrosyl radical species is involved in suicide inactivation (7). In cell-free systems, NO has been reported to trap the tyrosyl radical of the COXs, which leads to tyrosine iminoxyl radical formation and inactivation of the enzyme (8, 9).

The PG-biosynthetic pathway is initiated by activation of phospholipase A2 (PLA2), which are primarily responsible for agonist-induced arachidonic acid release from membrane phospholipids (10). Conversion of arachidonic acid to PGH2, the committed step in prostanoid biosynthesis, is mediated by both COX-1 and COX-2. The PGH2 is subsequently converted to a variety of eicosanoids depending on the downstream enzymatic machinery present in a particular cell type. The COX enzymes are thought to be the primary target enzymes for nonsteroidal antiinflammatory drugs, which block their ability to convert arachidonic acid to PGH2 (11).

Although it is recognized that there is "cross-talk" between products of the NOS and COX pathways, the literature is divided with respect to whether NO activates or inhibits PG production. For example, nitroglycerin (NO surrogate) is reported to inhibit platelet activation in vivo, which occurs via the stimulation of PG synthesis by endothelial cells (12). Salvemini and Masferrer (13) reported that NO stimulates COX activity in RAW 264.7 murine macrophages, possibly via reaction with the heme component which binds to the active site of the COX enzyme. In contrast, we and others have reported that endogenous NO inhibits PG synthesis in chondrocytes and LPS-stimulated macrophages (14, 15). In this study, we sought to determine whether these conflicting observations could be accounted for by divergent effects of NO on the two COX isoforms. In addition, the capacity of NO to promote NO modifications, such as tyrosine nitration, was investigated. Our studies indicate that NO exerts divergent effects on the constitutive and inducible COX isoforms, activating COX-1 but inactivating COX-2. Mechanisms by which NO exerts these effects on COX are explored.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Culture of murine macrophages

Mouse monocyte/macrophage cell line J774.A1 (ATCC TIB 67) was cultured in DMEM medium plus 10% FBS, 2 mM glutamine, 50 U/ml penicillin, and 50 µg/ml streptomycin. The cells were activated by IFN-{gamma}(100 U/ml) and LPS (5 µg/ml) in the presence and absence of N-L-methylarginine.

Culture of COX-deficient pulmonary fibroblasts

We utilized COX-1-/- (COX-1) or COX-2-/- (COX-2) lung fibroblasts, which express an immortalized phenotype and a hygromycin resistance gene as described by Kirtikara et al. (16). Cells were seeded in DMEM medium plus 10% FBS, 2 mM glutamine, 50 U/ml penicillin, 50 µg/ml streptomycin, and 250 µg/ml hygromycin.

Viability measurements

Cell viability was determined using a lactic dehydrogenase kit (Sigma, St. Louis, MO), and measurements were determined following the recommendations of the manufacturer. Results are expressed as a percentage compared with values obtained after treatment with PBS plus 0.1% Triton X-100.

RNA extraction

RNA was extracted using a Promega kit (Promega, Madison, WI). Northern blots used a hybridization probe prepared from full length cDNA for COX-1, and the procedure was performed as previously described (23).

NO treatment

NO solutions were prepared by dissolving diethylamine (DEA)/NO in 10 mM NaOH. NO was quantitated by measuring the absorbance at 250 nm as described by the manufacturer.

PGE2 measurement

In the macrophage studies, PGE2 biosynthesis was measured in cell fluid recovered after treatment by NO or LPS (24 h). In studies using COX-1/COX-2 cells, NO treatment was varied. The treatment medium was then removed, and cells were washed twice with fresh medium. Cells were placed in fresh medium, and the interval to harvest PGE2 release was 10 or 3 min (as described in text). PGE2 in the medium was measured by ELISA using a commercial kit (Cayman Chemicals, Ann Arbor, MI) following the instructions of the manufacturer.

Western blot analysis

Laemmli buffer was directly added to the cells at the termination of the reaction. Proteins were separated by SDS-PAGE (10%), and proteins were transferred to nitrocellulose and analyzed using rabbit anti-nitrotyrosine (Upstate Biotechnology, Lake Placid, NY), rabbit anti-COX-2 (Transduction Laboratories, Lexington, KY) rabbit anti-actin (Sigma), rabbit anti-GAPDH (Sigma), rabbit anti-glucose 6 phosphate dehydrogenase (gift from Dr. E. Beutler), and rabbit anti-cytosolic PLA2 (Upstate Biotechnology). Images were evaluated after scanning of autoradiographs using the storage phosphor technique performed with the Molecular Dynamics 400A PhosphorImager (Molecular Dynamics, Sunnyvale, CA).

Two-dimensional gel electrophoresis and trypsin digestion

Two-dimensional electrophoresis was performed as previously described (17, 18, 19). Detection of anti-COX-2 was by ECL, and then the same blot was reprobed with anti-nitrotyrosine which was reported by an alkaline phosphatase method. Lysate (20 mg/ml) was treated with bead-conjugated trypsin (Pierce, Rockford, IL, Immobilized tosylphenylchloromethyl ketone trypsin, 1 volume sample to 1 volume resin) at 4°C or 37°C (10 min). The beads were removed at 10,000 x g (1 min), and SDS sample buffer was added to the supernatant fraction. Proteins were separated by SDS-PAGE (10%), and proteins were transferred to nitrocellulose and analyzed using rabbit anti-nitrotyrosine, rabbit anti-COX-2 (Transduction), or rabbit anti-actin.

Data variability

Data were analyzed as the mean and the SEM. The levels of significance were calculated using Student’s t test.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
NO increases PGE2 production in resting murine macrophages

Exposure of resting macrophages to NO enhanced PGE2 release (Fig. 1Go). The enhancement of PGE2 production was inhibited by indomethacin (nonselective COX inhibitor) but not by the COX-2 selective inhibitor NS398. The dose-response relationship between NO and PGE2 production by macrophages was obtained by combining the data from four separate experiments. The amount of PGE2 produced was significantly greater than control (p < 0.01) at NO concentrations of 30 µM and above. NO-dependent PGE2 release by unstimulated macrophages was not due to increase in expression of PlA2 or COX-1 as assessed by Western blot analysis (Fig. 1Go). These findings suggest that activation of PLA2 or COX-1 is necessary for NO-dependent PGE2 production. To further separate the activation of PLA2 and COX-1, we performed experiments using immortalized, nontransformed cells derived from COX-1-deficient or COX-2-deficient mice (16). These cells exhibit increased basal PG production, which is due to a constitutively stimulated PLA2 and enhanced basal expression of the remaining COX isozyme.



View larger version (17K):
[in this window]
[in a new window]
  		FIGURE 1. Effect of exogenous NO on PGE2 production by murine macrophages. A and B, PGE2 release by resting macrophages with or without NO (30 µM, 24 h) in the presence or absence of indomethacin (INDO, 5 µM); NS 398 (10 µM) was analyzed by ELISA. C, Western blot analysis of COX-1 and cytosolic PLA2 in resting and macrophages with or without NO treatment.

 
NO increases PGE2 production in COX-2-deficient (but not COX-1-deficient) cells

The above studies, which showed enhancement of PGE2 production in unstimulated macrophages (not inhibited by NS-398), indicated that NO activates COX-1-dependent PGE2 production. We next examined the effect of exogenous NO on PGE2 release by COX-1 and COX-2-deficient cells. As shown in Fig. 2Go, treatment of COX-2-deficient cells with as low as 1 µM NO increased PGE2 release to 155% control and NO stimulated PGE2 synthesis in a dose-dependent manner. As expected, in COX-2-deficient cells, the NO-stimulated PGE2 release was inhibited by indomethacin but not by the COX-2 selective agent NS-398. Exposure of COX-2-deficient cells to NO (1 µM) in the presence of exogenously added arachidonic acid (10 µM) also enhanced PGE2 release by 180% (not shown). In contrast, and consistent with the conclusions drawn from studies of macrophages, exogenous NO failed to stimulate PGE2 release in COX-1-deficient cells; NO treatment, in fact, inhibited PGE2 release from these cells (Fig. 2Go).



View larger version (25K):
[in this window]
[in a new window]
  		FIGURE 2. NO increases PGE2 production by COX-2-, but not COX-1-, deficient cells. COX-1-deficient cells and COX-2-deficient cells were treated with NO (10 µM, 20 min, 37°C) with or without indomethacin (5 µM), NS 398 (10 µM), and then PGE2 in the media was assessed as described in Materials and Methods. Protein and RNA were isolated from the cells, and COX-1 expression (GAPDH as RNA loading control) was determined.

 
Further studies were undertaken to define the manner in which NO stimulates PGE2 production. COX-2-deficient cells were incubated with 10 µM NO for 20 and 60 min and protein and RNA were extracted to examine COX-1 expression. As shown in Fig. 2Go, NO treatment did not affect COX-1 expression of protein or mRNA. We next examined the kinetics of NO-dependent PGE2 production in COX-2-deficient cells (Fig. 3Go). Exposure of COX-2-deficient cells to 10 µM NO resulted in a rapid PGE2 release detectable at 1 min. After exposure to NO, PGE2 release reached its peak at 10 min and returned to baseline by 60 min. NO treatment at 100 µM resulted in a similar profile with a more gradual decrease to baseline. A23187 exposure resulted in a rapid increase in PGE2 release that was first measurable at 1 min and that, unlike the response to NO, was sustained during the 60-min observation period. Taken together, these results suggest that NO stimulates PGE2 release due to COX-1 activation and not by altering COX-1 expression.



View larger version (17K):
[in this window]
[in a new window]
  		FIGURE 3. Kinetics of PGE2 release by COX-2-deficient cells exposed to NO or the calcium ionophore A23187. COX-2-deficient cells were treated with NO (10 or 100 µM, time varied) or A23187 (5 µM, time varied). After exposure to NO or A23187, the medium was replaced, and each sample was incubated for 3 min. The x-axis refers to the treatment interval with NO or A23187, and the y-axis indicates PGE2 detected in the replacement media.

 
NO inhibits PGE2 biosynthesis by COX-1-deficient cells or by LPS-stimulated macrophages in association with decreased COX-2 expression

Additional experiments were performed to further explore the effects of NO on COX-2 activity and expression. As shown in Fig. 4Go, the exposure of COX-1 deficient cells to exogenous NO for 1 h decreased basal PGE2 release by >70%. In addition, we observed a 50% decrease in COX-2 protein expression compared with controls at 1 h. NO treatment did not affect cellular viability, nor did it reduce the expression of actin and GAPDH (control protein not shown). Similarly, in LPS-stimulated macrophages, NO exposure resulted in a decrease in PGE2 release and total COX-2 protein (at 24 h, Western blot (Fig. 4Go)). In experiments using varying doses of NO, we observed a correlation between PGE2 release and COX-2 expression (not shown).



View larger version (25K):
[in this window]
[in a new window]
  		FIGURE 4. NO inhibits PGE2 production and decreases COX-2 expression in COX-1-deficient cells and LPS-treated murine macrophage. A, PGE2 release by COX-1-deficient fibroblasts with or without NO (1 mM, time varied). B, PGE2 release by LPS-stimulated macrophages which were given a pretreatment with LPS (5 µg/ml) plus IFN-{gamma} (100 U/ml) (LPS-stimulated macrophages, 5 h) and then a second treatment with NO (30 µM, 18 h). C and D, Western blot analysis of COX-2 (actin as protein loading control).

 
NO inhibits PGE2 biosynthesis by COX-1-deficient cells or by LPS-stimulated macrophages in association with COX-2 nitration

The inhibition of PGE2 production in LPS-treated macrophages was accompanied by the formation of a 72-kDa nitrated protein (nitrotyrosine immunoblot (Fig. 5Go)). Coincubation of 3-nitrotyrosine (10 mM) prevented Ab binding to the 72-kDa protein (Western blot assay, not shown), confirming recognition by the Ab of a nitrated protein. To assess whether the 72-kDa protein could be identified as COX-2, we utilized two-dimensional gel electrophoresis and trypsin digestion. In lysates of LPS-stimulated macrophages exposed to 30 µM NO, the nitrated protein was separated by isoelectric focusing and by SDS-PAGE followed by transfer to nitrocellulose. As shown (Fig. 6Go), autoradiographic analysis revealed that COX-2 eluted at 72 kDa with an apparent pI of 7.5. The same blot was reanalyzed by Western blot using a rabbit anti-nitrotyrosine Ab. The analysis revealed that one of two nitrated proteins migrated with an identical molecular mass and apparent pI as COX-2. COX-2 is trypsin sensitive, and we next focused on the capacity of trypsin to digest the 72-kDa nitrated protein. The 72-kDa nitrated protein digestion was separated by SDS gels, transferred to nitrocellulose, and sequentially probed with anti-COX-2 and anti-nitrotyrosine. Treatment resulted in a loss of both immunodetectable COX-2 and the nitrated 72-kDa protein (Fig. 6Go); trypsin digestion did not affect G6PDH examined as a control (not shown).



View larger version (41K):
[in this window]
[in a new window]
  		FIGURE 5. COX-2 undergoes protein nitration after exposure to NO. A, control macrophages (as in Fig. 1Go) and LPS-stimulated macrophages (as in Fig. 4Go) were incubated with or without NO (NO varied, 1 h). B, COX-1-deficient cells were exposed to NO (1 mM, time varied). After treatments, proteins were separated on SDS-PAGE, transferred to nitrocellulose, and probed with an anti-nitrotyrosine Ab. As shown, a 72-kDa nitrated protein was detected in LPS-stimulated and COX-1-deficient cells, but not in controlled macrophages or COX-2-deficient cells.

 


View larger version (33K):
[in this window]
[in a new window]
  		FIGURE 6. Evidence that the 72-kDa nitrated protein reported in LPS macrophage exposed to NO is COX-2 as indicated by two-dimensional gel electrophoresis and trypsin digestion. LPS-stimulated macrophages were treated with DEA/NO (as in Fig. 5GoA, 1 mM). A, Lysates were separated by isoelectric focusing and by SDS-PAGE followed by transfer to nitrocellulose, and the blots were probed with an anti-nitrotyrosine Ab or with an anti-COX-2 Ab. Arrow indicates region of two-dimensional gel containing colocalization of Ag after probing for COX-2 and nitrotyrosine. B, Evidence that the 72-kDa nitrated protein as indicated by trypsin digestion. Lysate was incubated with or without trypsin: untreated (Lane 1); trypsin 4°C (5 min) (Lane 2); trypsin treatment 37°C (5 min) (Lane 3). Digest was separated by SDS-PAGE, and nitrocellulose blots were probed with an anti-nitrotyrosine Ab or with an anti-COX-2 Ab.

 
Thus, these findings indicate that NO induces the nitration of COX-2 in LPS-stimulated macrophages. As has been shown in cell-free systems by Gunther et al. (9), it is likely that such nitration inhibits the catalytic activity of the enzyme, as those authors have reported (8, 9). Whether COX-2 nitration decreases the stability of the enzyme and accounts for decreased COX-2 expression in NO-treated cells remains to be determined.

As shown in Fig. 5Go, exposure of resting macrophages to NO did not lead to protein nitration. We next examined the effect of NO on nitration of protein in COX-1-deficient cells. The exposure of these cells to NO lead to the formation of a 72-kDa nitrated protein (Fig. 5Go). In contrast to observations made with COX-1-deficient cells, NO exposure did not lead to the formation of a 72-kDa nitrated protein in COX-2-deficient cells (Fig. 5Go). These data indicate that COX-2 (but not COX-1) undergoes protein nitration after exposure to NO. The percentage of the protein that is nitrated is not known; thus, it is impossible to equate nitration with enzyme inhibition or instability of COX-2 expression.


   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
In this study, the effect of NO on PG biosynthesis by murine macrophages and COX-1 or -2-deficient murine fibroblasts was examined. We found that exposure of resting macrophages to NO enhanced PGE2 release. This enhancement was inhibited by indomethacin (nonselective COX inhibitor) but not by the COX-2 selective inhibitor NS398. In contrast, exposure of LPS-stimulated macrophages to NO inhibited PGE2 release. To test whether these divergent effects of NO depend on the COX isoform, we studied PGE2 production in immortalized, nontransformed cells derived from COX-1-deficient or COX-2-deficient mice. These cells release PGE2 due to increased basal expression of the remaining COX isozyme as well as the elevated expression of PLA2 (16). Using COX-deficient cell lines, we confirmed that NO activated COX-1- but inhibited COX-2- derived PG production. In addition, our studies demonstrate that the capacity of NO to inhibit PGE2 release is associated with a decrease in COX-2 expression as well as nitration of the enzyme. The NO dependent decrease in COX-2 expression has been previously reported and may be, in part, due to the attenuation of cytokine elicited transcription factors which regulate COX-2 expression such as NF {kappa} B (4, 15, 20, 21, 22). Recently, we have reported that NO also inhibits the translocation of COX-2 to a cytosolic compartment which favors enzyme activity (23).

As noted, our studies indicate that the inhibition of PGE synthesis by NO is accompanied by nitration of COX-2. Although it has been previously demonstrated that NO converts tyrosine to nitrotyrosine in cell-free cyclooxygenases (8, 9), this is the first report to show that the reaction occurs in cells and that COX-2 is more sensitive to nitration than COX-1. In these studies, we found that micromolar NO stimulated COX-2 nitration in LPS-stimulated macrophages and in COX-1-deficient cells. COX-2 nitration has been shown to inhibit the catalytic activity of the enzyme (8, 9). Whether nitration also decreases COX-2 protein stability remains to be determined.

In contrast to these effects of NO on COX-2, we did not find evidence for nitration of COX-1. However, the activation of COX-1 by NO may occur via an allosteric effect subsequent to S-nitrosylation that stimulates enzymatic activity as reported in a cell-free system by Hajjar et al. (24). Alternatively, the activation of COX-1 by NO could be linked to the effect of NO on glutathione metabolism. Our laboratory has demonstrated that neutrophils exposed to NO convert intracellular glutathione to a nitrosylated adduct (25). This has been termed "nitrosative stress" and had been implicated in the activation of signaling proteins such as p21ras and the transcription factor OxyR (26, 27). NO may therefore serve a role as a potent peroxide activator of COX-1 due to the depletion of reduced glutathione as suggested by Goodwin et al. (28).

In summary, NO activates COX-1 but inhibits COX-2-derived PG production. Because a variety of cells (e.g., endothelium, macrophages, chondrocytes) produce NO and PGs simultaneously in response to cytokines and other activators (3, 29), we speculate that enhanced PG biosynthesis by COX-1 in the presence of elevated levels of NO may contribute to inflammatory mitogenic and angiogenic processes. The studies here reported help resolve a lingering controversy in the literature regarding NOS/COX cross-talk by demonstrating divergent effects of NO on the COX isoforms. The regulation of PGE production by NO is therefore complex and will depend on the local environment in which these pleiotropic mediators are produced.


   Acknowledgments
 
We thank Maddy Rios for assistance in the preparation of the manuscript.


   Footnotes
 
1 This work was supported by a Biomedical Science Grant from the National Arthritis Foundation to S.B.A. and by the Joseph and Sophia Abeles Foundation. Back

2 Address correspondence and reprint requests to Dr. Robert Clancy, Department of Rheumatology, Hospital for Joint Diseases, 301 E. 17the Street, New York, NY 10003. Back

3 Abbreviations used in this paper: NOS, NO synthase; COX, cyclooxygenase; DEA, diethylamine; PLA2' phospholipase A2. Back

Received for publication January 27, 2000. Accepted for publication May 11, 2000.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Smith, W. L., R. M. Garavito, D. L. DeWitt. 1996. Prostaglandin endoperoxide H synthases (cyclooxygenases)-1 and -2. J. Biol. Chem. 271:33157.[Free Full Text]
  2. Michel, T., Q.-W. Xie, C. Nathan. 1995. Molecular biological analysis of nitric oxide synthases. , , ed. Methods in Nitric Oxide Research 161. John Wiley & Sons, U.K.
  3. Clancy, R. M., A. R. Amin, S. B. Abramson. 1998. The role of nitric oxide in inflammation and immunity. Arthritis Rheum. 41:1141.[Medline]
  4. Diaz-Cazorla, M., D. Perez-Sala, S. Lamas. 1999. Dual effect of nitric oxide donors on cyclooxygenase-2 expression in human mesangial cells. J. Am. Soc. Nephrol. 10:943.[Abstract/Free Full Text]
  5. Dubois, R. N., S. B. Abramson, L. Crofford, R. A. Gupta, L. S. Simon, L. B. Van De Putte, P. E. Lipsky. 1998. Cyclooxygenase in biology and disease. FASEB J. 12:1063.[Abstract/Free Full Text]
  6. Smith, W. L., D. L. DeWitt. 1996. Prostaglandin endoperoxide H synthases-1 and -2. Adv. Immunol. 62:167.[Medline]
  7. Tsai, A., R. J. Kulmacz, G. Palmer. 1995. Spectroscopic evidence for reaction of prostaglandin H synthase-1 tyrosyl radical with arachidonic acid. J. Biol. Chem. 270:10503.[Abstract/Free Full Text]
  8. Goodwin, D. C., M. R. Gunther, L. C. Hsi, B. C. Crews, T. E. Eling, R. P. Mason, L. J. Marnett. 1998. Nitric oxide trapping of tyrosyl radicals generated during prostaglandin endoperoxide synthase turnover: detection of the radical derivative of tyrosine 385. J. Biol. Chem. 273:8903.[Abstract/Free Full Text]
  9. Gunther, M. R., L. C. Hsi, J. F. Curtis, J. K. Gierse, L. J. Marnett, T. E. Eling, R. P. Mason. 1997. Nitric oxide trapping of the tyrosyl radical of prostaglandin H synthase-2 leads to tyrosine iminoxyl radical and nitrotyrosine formation. J. Biol. Chem. 272:17086.[Abstract/Free Full Text]
  10. Lin, L. L., M. Wartmann, A. Y. Lin, J. L. Knopf, A. Seth, R. J. Davis. 1993. cPLA2 is phosphorylated and activated by MAP kinase. Cell 72:269.[Medline]
  11. Vane, J. R., R. M. Botting. 1995. A better understanding of anti-inflammatory drugs based on isoforms of cyclooxygenase (COX-1 and COX-2). Adv. Prostaglandin Thromboxane Leukot. Res. 23:41.[Medline]
  12. Levin, R. I., E. A. Jaffe, B. B. Weksler, K. Tack-Goldman. 1981. Nitroglycerin stimulates synthesis of prostacyclin by cultured human endothelial cells. J. Clin. Invest. 67:762.
  13. Salvemini, D., T. P. Misko, J. L. Masferrer, K. Seibert, M. G. Currie, P. Needleman. 1993. Nitric oxide activates cyclooxygenase enzymes. Proc. Natl. Acad. Sci. USA 90:7240.[Abstract/Free Full Text]
  14. Amin, A. R., M. Attur, R. N. Patel, G. D., P. J. Thakker, J. Marshall, S. A. Rediske, I. R. Patel Stuchin, S. B. Abramson. 1997. Superinduction of cyclooxygenase-2 activity in human osteoarthritis-affected cartilage: influence of nitric oxide. J. Clin. Invest. 99:1231.[Medline]
  15. Habib, A., C. Bernard, M. Lebret, C. Creminon, B. Esposito, A. Tedgui, J. Maclouf. 1997. Regulation of the expression of cyclooxygenase-2 by nitric oxide in rat peritoneal macrophages. J. Immunol. 158:3845.[Abstract]
  16. Kirtikara, K., S. G. Morham, R. Raghow, S. J. Laulederkind, T. Kanekura, S. Goorha, L. R. Ballou. 1998. Compensatory prostaglandin E2 biosynthesis in cyclooxygenase 1 or 2 null cells. J. Exp. Med. 187:517.[Abstract/Free Full Text]
  17. Clancy, R. M., J. Leszczynska-Piziak, S. B. Abramson. 1993. Nitric oxide stimulates the ADP-ribosylation of actin in human neutrophils. Biochem. Biophys. Res. Commun. 191:847.[Medline]
  18. Clancy, R., J. Leszczynska, A. Amin, D. Levartovsky, S. B. Abramson. 1995. Nitric oxide stimulates ADP ribosylation of actin in association with the inhibition of actin polymerization in human neutrophils. J. Leukocyte Biol. 58:196.[Abstract]
  19. Hochstrasser, D. F., M. G. Harrington, A. C. Hochstrasser, M. J. Miller, C. R. Merril. 1988. Methods for increasing the resolution of two-dimensional protein electrophoresis. Anal. Biochem. 173:424.[Medline]
  20. Spiecker, M., H. B. Peng, J. K. Liao. 1997. Inhibition of endothelial vascular cell adhesion molecule-1 expression by nitric oxide involves the induction and nuclear translocation of I{kappa}B{alpha}. J. Biol. Chem. 272:30969.[Abstract/Free Full Text]
  21. Peng, H. B., M. Spiecker, J. K. Liao. 1998. Inducible nitric oxide: an autoregulatory feedback inhibitor of vascular inflammation. J. Immunol. 161:1970.[Abstract/Free Full Text]
  22. Perkins, D. J., D. A. Kniss. 1999. Blockade of nitric oxide formation down-regulates cyclooxygenase-2 and decreases PGE2 biosynthesis in macrophages. J. Leukocyte Biol. 65:792.[Abstract]
  23. Patel, R., M. G. Attur, M. Dave, S. B. Abramson, A. R. Amin. 1999. Regulation of cytosolic COX-2 and prostaglandin E2 production by nitric oxide in activated murine macrophages. J. Immunol. 162:4191.[Abstract/Free Full Text]
  24. Hajjar, D. P., H. M. Lander, S. Frieda, A. Pearce. 1995. Nitric oxide enhances prostaglandin-H-synthase-1 activity by a heme-independent mechanism: evidence for involvement of nitrosothiols. J. Am. Chem. Soc. 117:3340.
  25. Clancy, R. M., D. Levartovsky, J. Leszczynska-Piziak, J. Yegudin, S. B. Abramson. 1994. Nitric oxide reacts with intracellular glutathione and activates the hexose monophosphate shunt in human neutrophils: evidence for S-nitrosoglutathione as a bioactive intermediary. Proc. Natl. Acad. Sci. USA 91:3680.[Abstract/Free Full Text]
  26. Hausladen, A., C. T. Privalle, T. Keng, J. DeAngelo, J. S. Stamler. 1996. Nitrosative stress: activation of the transcription factor OxyR. Cell 86:719.[Medline]
  27. Lander, H. M., J. S. Ogiste, S. F. Pearce, R. Levi, A. Novogrodsky. 1995. Nitric oxide-stimulated guanine nucleotide exchange on p21ras. J. Biol. Chem. 270:7017.[Abstract/Free Full Text]
  28. Goodwin, D. C., L. M. Landino, L. J. Marnett. 1999. Effects of nitric oxide and nitric oxide-derived species on prostaglandin endoperoxide synthase and prostaglandin biosynthesis. FASEB J. 13:1121.[Abstract/Free Full Text]
  29. Amin, A. R., M. Attur, S. B. Abramson. 1999. Nitric oxide synthase and cyclooxygenases: distribution, regulation, and intervention in arthritis. Curr. Opin. Rheumatol. 11:202.[Medline]



This article has been cited by other articles:


Home page
 Circ. Res.Home page
V. Rudolph and B. A. Freeman
Cardiovascular Consequences When Nitric Oxide and Lipid Signaling Converge
Circ. Res., September 11, 2009; 105(6): 511 - 522.
[Abstract] [Full Text] [PDF]

Home page
 IOVSHome page
I. K. Petropoulos, J.-A. C. Pournaras, A. N. Stangos, and C. J. Pournaras
Effect of Systemic Nitric Oxide Synthase Inhibition on Optic Disc Oxygen Partial Pressure in Normoxia and in Hypercapnia
Invest. Ophthalmol. Vis. Sci., January 1, 2009; 50(1): 378 - 384.
[Abstract] [Full Text] [PDF]

Home page
 Ann Rheum DisHome page
S C Mastbergen, J W J Bijlsma, and F P J G Lafeber
Synthesis and release of human cartilage matrix proteoglycans are differently regulated by nitric oxide and prostaglandin-E2
Ann Rheum Dis, January 1, 2008; 67(1): 52 - 58.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
C. Feleder, V. Perlik, and C. M. Blatteis
Preoptic nitric oxide attenuates endotoxic fever in guinea pigs by inhibiting the POA release of norepinephrine
Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1144 - R1151.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
J. Aisemberg, C. Vercelli, S. Billi, M. L. Ribeiro, D. Ogando, R. Meiss, S. M. McCann, V. Rettori, and A. M. Franchi
Nitric oxide mediates prostaglandins' deleterious effect on lipopolysaccharide-triggered murine fetal resorption
PNAS, May 1, 2007; 104(18): 7534 - 7539.
[Abstract] [Full Text] [PDF]

Home page
 BloodHome page
K. Sato, K. Ozaki, I. Oh, A. Meguro, K. Hatanaka, T. Nagai, K. Muroi, and K. Ozawa
Nitric oxide plays a critical role in suppression of T-cell proliferation by mesenchymal stem cells
Blood, January 1, 2007; 109(1): 228 - 234.
[Abstract] [Full Text] [PDF]

Home page
 Hum Reprod UpdateHome page
K.R. Barnett, C. Schilling, C.R. Greenfeld, D. Tomic, and J.A. Flaws
Ovarian follicle development and transgenic mouse models
Hum. Reprod. Update, September 1, 2006; 12(5): 537 - 555.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
G. R. McCord, J.-L. Cracowski, and C. T. Minson
Prostanoids contribute to cutaneous active vasodilation in humans
Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R596 - R602.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
D. Sun, H. Liu, C. Yan, A. Jacobson, C. Ojaimi, A. Huang, and G. Kaley
COX-2 contributes to the maintenance of flow-induced dilation in arterioles of eNOS-knockout mice
Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1429 - H1435.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
M. Jerkic, J. V. Rivas-Elena, J. F. Santibanez, M. Prieto, A. Rodriguez-Barbero, F. Perez-Barriocanal, M. Pericacho, M. Arevalo, C. P.H. Vary, M. Letarte, et al.
Endoglin Regulates Cyclooxygenase-2 Expression and Activity
Circ. Res., August 4, 2006; 99(3): 248 - 256.
[Abstract] [Full Text] [PDF]

Home page
 JBJSHome page
J. C. Lotz and J. A. Ulrich
Innervation, Inflammation, and Hypermobility May Characterize Pathologic Disc Degeneration: Review of Animal Model Data
J. Bone Joint Surg. Am., April 1, 2006; 88(suppl_2): 76 - 82.
[Abstract] [Full Text] [PDF]

Home page
 Endocr. Rev.Home page
H. N. Jabbour, R. W. Kelly, H. M. Fraser, and H. O. D. Critchley
Endocrine Regulation of Menstruation
Endocr. Rev., February 1, 2006; 27(1): 17 - 46.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
I. N. Bratz and N. L. Kanagy
Nitric oxide synthase-inhibition hypertension is associated with altered endothelial cyclooxygenase function
Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2394 - H2401.
[Abstract] [Full Text] [PDF]

Home page
 Pharmacol. Rev.Home page
D. L. Simmons, R. M. Botting, and T. Hla
Cyclooxygenase Isozymes: The Biology of Prostaglandin Synthesis and Inhibition
Pharmacol. Rev., September 1, 2004; 56(3): 387 - 437.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
J. L. Gookin, L. L. Duckett, M. U. Armstrong, S. H. Stauffer, C. P. Finnegan, M. P. Murtaugh, and R. A. Argenzio
Nitric oxide synthase stimulates prostaglandin synthesis and barrier function in C. parvum-infected porcine ileum
Am J Physiol Gastrointest Liver Physiol, September 1, 2004; 287(3): G571 - G581.
[Abstract] [Full Text] [PDF]

Home page
 CarcinogenesisHome page
K.-S. Chun, H.-H. Cha, J.-W. Shin, H.-K. Na, K.-K. Park, W.-Y. Chung, and Y.-J. Surh
Nitric oxide induces expression of cyclooxygenase-2 in mouse skin through activation of NF-{kappa}B
Carcinogenesis, March 1, 2004; 25(3): 445 - 454.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
A. Huang, D. Sun, Z. Wu, C. Yan, M. A. Carroll, H. Jiang, J. R. Falck, and G. Kaley
Estrogen Elicits Cytochrome P450--Mediated Flow-Induced Dilation of Arterioles in NO Deficiency: Role of PI3K-Akt Phosphorylation in Genomic Regulation
Circ. Res., February 6, 2004; 94(2): 245 - 252.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
N. Harada, K. Okajima, M. Uchiba, and T. Katsuragi
Contribution of capsaicin-sensitive sensory neurons to stress-induced increases in gastric tissue levels of prostaglandins in rats
Am J Physiol Gastrointest Liver Physiol, December 1, 2003; 285(6): G1214 - G1224.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J. Belik, R. P. Jankov, J. Pan, M. Yi, C. R. Pace-Asciak, and A. K. Tanswell
Effect of 8-isoprostaglandin F2{alpha} on the newborn rat pulmonary arterial muscle and endothelium
J Appl Physiol, November 1, 2003; 95(5): 1979 - 1985.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
G. Zauli, A. Pandolfi, A. Gonelli, R. Di Pietro, S. Guarnieri, G. Ciabattoni, R. Rana, M. Vitale, and P. Secchiero
Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Sequentially Upregulates Nitric Oxide and Prostanoid Production in Primary Human Endothelial Cells
Circ. Res., April 18, 2003; 92(7): 732 - 740.
[Abstract] [Full Text] [PDF]

Home page
 CarcinogenesisHome page
Q. Liu, S.T.F. Chan, and R. Mahendran
Nitric oxide induces cyclooxygenase expression and inhibits cell growth in colon cancer cell lines
Carcinogenesis, April 1, 2003; 24(4): 637 - 642.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
L. Chen, H. He, E. F. Mondejar, and G. Hedenstierna
Cyclooxygenase inhibitor blocks rebound response after NO inhalation in an endotoxin model
Am J Physiol Heart Circ Physiol, January 1, 2003; 284(1): H290 - H298.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
Y.-Q. Zhou, Y.-Q. Chen, J. H. Fisher, and M.-H. Wang
Activation of the RON Receptor Tyrosine Kinase by Macrophage-stimulating Protein Inhibits Inducible Cyclooxygenase-2 Expression in Murine Macrophages
J. Biol. Chem., October 4, 2002; 277(41): 38104 - 38110.
[Abstract] [Full Text] [PDF]

Home page
 Cardiovasc ResHome page
R. Bolli, K. Shinmura, X.-L. Tang, E. Kodani, Y.-T. Xuan, Y. Guo, and B. Dawn
Discovery of a new function of cyclooxygenase (COX)-2: COX-2 is a cardioprotective protein that alleviates ischemia/reperfusion injury and mediates the late phase of preconditioning
Cardiovasc Res, August 15, 2002; 55(3): 506 - 519.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
W. H. Beierwaltes
Cyclooxygenase-2 products compensate for inhibition of nitric oxide regulation of renal perfusion
Am J Physiol Renal Physiol, July 1, 2002; 283(1): F68 - F72.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
K. Shinmura, Y.-T. Xuan, X.-L. Tang, E. Kodani, H. Han, Y. Zhu, and R. Bolli
Inducible Nitric Oxide Synthase Modulates Cyclooxygenase-2 Activity in the Heart of Conscious Rabbits During the Late Phase of Ischemic Preconditioning
Circ. Res., March 22, 2002; 90(5): 602 - 608.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
Y. Zhang and C. W. Leffler
Compensatory role of NO in cerebral circulation of piglets chronically treated with indomethacin
Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2002; 282(2): R400 - R410.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
A. Huang, Y. Wu, D. Sun, A. Koller, and G. Kaley
Effect of estrogen on flow-induced dilation in NO deficiency: role of prostaglandins and EDHF
J Appl Physiol, December 1, 2001; 91(6): 2561 - 2566.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
A. A. Nanji, K. Jokelainen, G. K. K. Lau, A. Rahemtulla, G. L. Tipoe, R. Polavarapu, and E.-N. Lalani
Arginine Reverses Ethanol-Induced Inflammatory and Fibrotic Changes in Liver Despite Continued Ethanol Administration
J. Pharmacol. Exp. Ther., December 1, 2001; 299(3): 832 - 839.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
S.-H. Su, H.-i. Chen, and C. J. Jen
C57BL/6 and BALB/c Bronchoalveolar Macrophages Respond Differently to Exercise
J. Immunol., November 1, 2001; 167(9): 5084 - 5091.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
Y. Devaux, C. Seguin, S. Grosjean, N. de Talance, V. Camaeti, A. Burlet, F. Zannad, C. Meistelman, P.-M. Mertes, and D. Longrois
Lipopolysaccharide-Induced Increase of Prostaglandin E2 Is Mediated by Inducible Nitric Oxide Synthase Activation of the Constitutive Cyclooxygenase and Induction of Membrane-Associated Prostaglandin E Synthase
J. Immunol., October 1, 2001; 167(7): 3962 - 3971.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
Y. Devaux, C. Seguin, S. Grosjean, N. de Talance, M. Schwartz, A. Burlet, F. Zannad, C. Meistelman, P.-M. Mertes, and D. Ungureanu-Longrois
Retinoic Acid and Lipopolysaccharide Act Synergistically to Increase Prostanoid Concentrations in Rats In Vivo
J. Nutr., October 1, 2001; 131(10): 2628 - 2635.
[Abstract] [Full Text] [PDF]

Home page
 Infect. Immun.Home page
G. M. Anstead, B. Chandrasekar, W. Zhao, J. Yang, L. E. Perez, and P. C. Melby
Malnutrition Alters the Innate Immune Response and Increases Early Visceralization following Leishmania donovani Infection
Infect. Immun., August 1, 2001; 69(8): 4709 - 4718.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
N. Ueno, M. Murakami, T. Tanioka, K. Fujimori, T. Tanabe, Y. Urade, and I. Kudo
Coupling between Cyclooxygenase, Terminal Prostanoid Synthase, and Phospholipase A2
J. Biol. Chem., September 7, 2001; 276(37): 34918 - 34927.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
K. Shinmura, Y.-T. Xuan, X.-L. Tang, E. Kodani, H. Han, Y. Zhu, and R. Bolli
Inducible Nitric Oxide Synthase Modulates Cyclooxygenase-2 Activity in the Heart of Conscious Rabbits During the Late Phase of Ischemic Preconditioning
Circ. Res., March 22, 2002; 90(5): 602 - 608.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Clancy, R.
Right arrow Articles by Abramson, S. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Clancy, R.
Right arrow Articles by Abramson, S. B.
Right arrowPubmed/NCBI databases
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*NITRIC OXIDE

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS