Donate Help Contact The AHA Sign In Home
American Heart Association
Arteriosclerosis, Thrombosis, and Vascular Biology
Search: search_blue_button Advanced Search
Arteriosclerosis, Thrombosis, and Vascular Biology. 2001;21:55-60

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
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 arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fontana, L.
Right arrow Articles by Laudanna, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fontana, L.
Right arrow Articles by Laudanna, C.
Related Collections
Right arrow Pathophysiology
Right arrow Ischemic biology - basic studies
Right arrow Acute coronary syndromes
Right arrow Oxidant stress
(Arteriosclerosis, Thrombosis, and Vascular Biology. 2001;21:55.)
© 2001 American Heart Association, Inc.


Vascular Biology

8-Iso-PGF2{alpha} Induces ß2-Integrin–Mediated Rapid Adhesion of Human Polymorphonuclear Neutrophils

A Link Between Oxidative Stress and Ischemia/Reperfusion Injury

Luigi Fontana; Cinzia Giagulli; Pietro Minuz; Alessandro Lechi; Carlo Laudanna

From the Department of Biomedical and Surgical Sciences (L.F., P.M., A.L.) and the Department of Pathology, Section of General Pathology (C.G., C.L.), University of Verona, Verona, Italy.

Correspondence to Dr Luigi Fontana, Department of Biomedical and Surgical Sciences, Medicina Interna C, Policlinico GB Rossi, Piazzale LA Scuro, 37134 Verona, Italy. E-mail lechi{at}borgoroma.univr.it


*    Abstract
up arrowTop
*Abstract
down arrowIntroduction
down arrowMethods
down arrowResults
down arrowDiscussion
down arrowReferences
 
Abstract—F2-Isoprostanes are generated from a cyclooxygenase-independent oxidative modification of arachidonic acid. They are present in atherosclerotic plaques and are platelet activators as well as potent vasoconstrictors. Polymorphonuclear neutrophils are major players in ischemia/reperfusion injury and in restenosis after PTCA. The effects of 8-isoprostaglandin (PG) F2{alpha} on very rapid ß2-integrin–dependent adhesion was evaluated in human neutrophils in vitro by use of purified integrin as ligand. 8-Iso-PGF2{alpha} (1 nmol/L to 20 µmol/L) triggers a dose-dependent, very rapid neutrophil adhesion to human fibrinogen but not to the endothelial ligand intercellular adhesion molecule-1. Pretreatment with anti–ß2-integrin subtypes showed activation of CD11b/CD18 and CD11c/CD18. Adhesion triggering was completely prevented by pertussis toxin. SQ29,548, a specific antagonist of thromboxane A2 receptor, also dose-dependently prevented 8-iso-PGF2{alpha}–triggered neutrophil adhesion. 8-Iso-PGF2{alpha} did not trigger adhesion in human monocytes and lymphocytes and did not induce neutrophil chemotaxis or activation of the oxygen free-radical–forming enzyme NADPH-oxidase. These data highlight the role of 8-iso-PGF2{alpha} as a specific activator of rapid neutrophil adhesion and suggest its involvement in the pathogenesis of ischemia/reperfusion injury and in restenosis after PTCA. The effect is transduced via activation of the receptor for thromboxane A2.


Key Words: neutrophils • adhesion • 8-iso-PGF2{alpha} • thromboxane A2 receptor • ß2-integrins


*    Introduction
up arrowTop
up arrowAbstract
*Introduction
down arrowMethods
down arrowResults
down arrowDiscussion
down arrowReferences
 
F2-Isoprostanes are a series of prostaglandin (PG) F2–like isomers formed primarily by a free-radical mechanism from arachidonic acid on cell membranes and LDL particles. F2-Isoprostanes can be measured in both plasma and urine1 and have been shown to be increased in association with clinical conditions such as coronary ischemia/reperfusion syndrome,2 adult respiratory distress syndrome,3 diabetes mellitus,4 and chronic pulmonary disease.5 They are also increased in association with several risk factors for the development of ischemic vascular disease, including cigarette smoking,6 hypercholesterolemia,7 and hyperhomocysteinemia.8 Thus, analysis of F2-isoprostanes has emerged as a specific and reliable marker of oxidant stress in vivo.1 Although oxygen free-radical reactions have been implicated in chronic diseases, it is important to underline that the relationship between oxidative stress and the onset and progression of such disease processes is not fully established. Nonetheless, one of the F2-isoprostanes formed during lipid peroxidation, 8-iso-PGF2{alpha}, has been found to be a potent vasoconstrictor9 and to modulate several platelet functions via stimulation of thromboxane A2 receptors (TP).10 11 Thus far, however, nothing is known about the effect of isoprostanes on the biology of inflammatory cells.

Proinflammatory reactions rely primarily on the capability of leukocytes to recognize and adhere to the blood vessels. The process leading to leukocyte extravasation is a finely regulated sequence of steps controlled by both adhesion molecules and activating factors. Selective recruitment of various leukocyte subtypes under physiopathological situations depends on the action of different classes of adhesion molecules and activating factors whose combination generates a tissue-specific "area code."12 Activating factors are major players in leukocyte recruitment, because integrins do not mediate firm adhesion unless activated. Signaling events triggered by physiological proadhesive agonists must be very efficient. Indeed, integrin activation needs to be extremely rapid (because arrest often occurs within seconds) and stable to counteract the blood-flow shear stress. Proinflammatory agonists, such as bacterial formyl peptides, complement factors, and lipid-derived products, stimulate integrin-dependent adhesion and chemotaxis in polymorphonuclear leukocytes.13 14 15 16 Notably, integrin activation has emerged as a very active area of investigation, because a complete understanding of the molecular mechanisms leading to the activation of integrin-dependent leukocyte adhesion could open new therapeutic perspectives in inflammatory diseases.

Because an inflammatory response leading to tissue injury has been demonstrated in the pathogenesis of the atherosclerotic process, ischemia-reperfusion syndrome, and restenosis after percutaneous transluminal coronary angioplasty (PTCA),17 in which increased isoprostane generation is observed, we set out to explore the effects of 8-iso-PGF2{alpha} on the proinflammatory activities of human inflammatory cells. Here, we evaluated the involvement of 8-iso-PGF2{alpha} in rapid integrin-mediated adhesion and chemotaxis triggering in human polymorphonuclear neutrophils, monocytes, and lymphocytes. We show that 8-iso-PGF2{alpha} is a highly selective integrin activator of human neutrophils with respect to rapid adhesion but not chemotaxis triggering, whereas no effect was found on other leukocyte subtypes.


*    Methods
up arrowTop
up arrowAbstract
up arrowIntroduction
*Methods
down arrowResults
down arrowDiscussion
down arrowReferences
 
Reagents and Antibodies
N-Formyl-Met-Leu-Phe (fMLP) was from Sigma; pertussis toxin (PTx) was from Alexis Biochem; 8-iso-PGF2{alpha}, 8-iso-PGF3{alpha}, PGF2{alpha}, the TP agonist U46619, and the TP antagonist SQ29,548 were from Cayman Chemical; anti-human CD11a blocking monoclonal antibody was kindly donated by Dr Chilosi (University of Verona, Department of Pathology); anti-human CD11c blocking monoclonal antibody was from Santa Cruz Biotech; and anti-human CD11b blocking monoclonal antibody was from Repligen Corp. Recombinant human intercellular adhesion molecule (ICAM)-1 was purified as an Ig–ICAM-1 fusion chimera (Ig H chain 2 and 3) from supernatants of stably transfected Chinese hamster ovary cell lines. All lipids and peptides were solubilized immediately before use at 1 mmol/L concentrations in PBS, pH 7.2. Dilutions of 8-iso-PGF2{alpha} were in PBS. Stock solution was in ethanol 2.8 mmol/L and was kept at -20°C. Ethanol was removed by nitrogen stream evaporation, and solubility in PBS was achieved by immediate sonication on ice with a batch sonicator (3 bursts of 1 minute each at 400 W).

Isolation of Human Polymorphonuclear Cells, Monocytes, and Lymphocytes
Blood was collected from healthy donors and anticoagulated in citrate. Human blood polymorphonuclear neutrophils were isolated by dextran sedimentation and centrifugation over Ficoll-Hypaque (Amersham Pharmacia Biotech) as described previously.18 Contaminating erythrocytes were lysed by hypotonic saline, and then neutrophils were washed with PBS and finally resuspended in RPMI 1640 containing 10% FCS. Human blood monocytes and lymphocytes were then isolated by Percoll density fractionation.19 All of the above procedures were done under sterile conditions and used reagents prepared in endotoxin-free water for clinical use.

Rapid Adhesion Assay
Eighteen-well glass slides were coated for 120 minutes at 37°C with human fibrinogen (Sigma) (20 µg/well in endotoxin-free PBS) or with purified human ICAM-1. Neutrophils (5x104/well; 2.5x106/mL in RPMI 1640, containing 10% heat-inactivated FCS and 20 mmol/L HEPES, pH 7.3) were added, incubated for 10 minutes at 37°C, stimulated by addition of the agonists before washing, and fixed on ice in 1.5% glutaraldehyde for 60 minutes, and computer-assisted enumeration of cells bound in 0.2 mm2 was done as described.20

Chemotaxis Assays
Migration of polymorphonuclear neutrophils, monocytes, and lymphocytes was assessed in 1-µm or 5-µm pore size transwells (Bio-Coat, Becton Dickinson). Neutrophils, monocytes, and lymphocytes were at 2x106/mL in RPMI 1640, without FCS, containing 20 mmol/L HEPES, pH 7.3. Cell suspension (100 µL) was added to the top well, and 600 µL of medium containing agonists was added to the bottom well. After fixation with 1.5% glutaraldehyde, migrated cells were counted by fluorescence-activated cell sorting using polystyrene beads (Polyscience) as an internal standard.21

Hydrogen Peroxide Release
H2O2 was measured fluorometrically by conversion of the nonfluorescent compound 4-hydroxy-3-methoxyphenylacetic acid (homovanilic acid) to the highly fluorescent 2,2'-dihydroxy-3,3'-dimethoxydiphenyl-5,5'-diacetic acid, catalyzed by horseradish peroxidase in the presence of H2O2.22 The conversion of the homovanilic acid was assessed at an excitation wavelength of 315 nm and an emission wavelength of 425 nm in a Perkin-Elmer LS-5 Luminescence Spectrometer. The amount of H2O2 produced was calculated from a standard curve using known dilutions of H2O2.


*    Results
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
*Results
down arrowDiscussion
down arrowReferences
 
To test the relevance of isoprostanes in rapid integrin-dependent adhesion triggering, we first evaluated the capability of 8-iso-PGF2{alpha} to induce rapid leukocyte binding to purified integrin ligands. As shown in Figure 1Down, 8-iso-PGF2{alpha} triggered rapid neutrophil adhesion to human fibrinogen in a dose-dependent manner. Notably, 8-iso-PGF2{alpha} induced rapid and consistent adhesion already at 1 nmol/L concentration. At 20 µmol/L concentration, triggered adhesion was {approx}73% of the maximal binding induced by fMLP. Thus, 8-iso-PGF2{alpha} was a strong agonist with respect to neutrophil adhesion triggering to fibrinogen. We also tested 3 structurally related compounds, 8-iso-PGF3{alpha}, 8-iso-PGF2{alpha}, and U46619 (10 to 10000 nmol/L). All of them displayed a similar dose-dependent agonistic activity toward neutrophil adhesion to fibrinogen, with the maximum effect observed at 10 µmol/L (with an average induction of adhesion of 2.7 and 2.2 times greater than nonstimulated cells, data not shown). Pretreatment of neutrophils with the TP antagonist SQ29,548 (5 and 20 µmol/L for 30 minutes at room temperature) blocked both 8-iso-PGF2{alpha}– and U46619 (0.5 µmol/L)–triggered adhesion, with an average inhibition of {approx}36% and 60%, respectively (Figure 2Down). We then evaluated the capability of 8-iso-PGF2{alpha} to trigger neutrophil adhesion to purified human ICAM-1. Surprisingly, 8-iso-PGF2{alpha} did not induce neutrophil adhesion to ICAM-1, even at the highest concentrations (Figure 3Down). We investigated whether other leukocyte subtypes were responsive to 8-iso-PGF2{alpha}. Interestingly, 8-iso-PGF2{alpha} did not induce adhesion to fibrinogen or to ICAM-1 in either monocytes or lymphocytes (not shown). We also evaluated other cellular phenomena normally induced by classic chemoattractants, such as chemotaxis and activation of oxygen free-radical release. 8-Iso-PGF2{alpha} did not trigger chemotaxis in neutrophils, monocytes, or lymphocytes and did not directly stimulate the activation of the oxygen free-radical–forming enzyme NADPH-oxidase, as evaluated by hydrogen peroxide release (data not shown). To exclude the possibility that rapid integrin triggering was a consequence of a generic plasma membrane alteration due to the lipidic nature of 8-iso-PGF2{alpha}, we evaluated the effect of PTx pretreatment on adhesion triggering by 8-iso-PGF2{alpha}. As shown in Figure 4Down, PTx pretreatment almost completely abolished 8-iso-PGF2{alpha}–induced binding of neutrophils to fibrinogen. The inhibitory effect of PTx was not due to a generic toxic effect of PTx pretreatment, because neutrophils still retained the capability to fully adhere upon triggering by phorbol 12-myristate 13-acetate (data not shown). This suggests that 8-iso-PGF2{alpha} induces neutrophil rapid integrin activation through a signaling pathway dependent on PTx-sensitive trimeric GTP-binding proteins.



View larger version (21K):
[in this window]
[in a new window]
 
Figure 1. 8-Iso-PGF2{alpha} triggers rapid neutrophil adhesion to fibrinogen. Eighteen-well glass slides were coated with human fibrinogen. Neutrophils were stimulated at 37°C for 3 minutes with buffer, with no agonist, or with 100 nmol/L fMLP or with the indicated concentrations of 8-iso-PGF2{alpha}. Values are the mean counts of bound cells in 0.2 mm2. Error bars represent SD. A representative experiment of 10 similar experiments is presented.



View larger version (19K):
[in this window]
[in a new window]
 
Figure 2. 8-Iso-PGF2{alpha}–triggered adhesion to fibrinogen is blocked by the TP antagonist. Eighteen-well glass slides were coated with human fibrinogen. Neutrophils were pretreated with 5 and 20 µg/mL of SQ29,548 (a selective TP antagonist) for 2 hours at room temperature and then stimulated at 37°C for the 3 minutes with buffer, with no agonist, or with 0.5 µmol/L 8-iso-PGF2{alpha} and U46619. Values are the mean counts of bound cells in 0.2 mm2 in 3 separate experiments. Error bars represent SD.



View larger version (14K):
[in this window]
[in a new window]
 
Figure 3. 8-Iso-PGF2{alpha} does not trigger rapid neutrophil adhesion to ICAM-1. Eighteen-well glass slides were coated with human fibrinogen. Neutrophils were stimulated at 37°C for the 3 minutes with buffer, with no agonist, or with 100 nmol/L fMLP or with the indicated concentrations of 8-iso-PGF2{alpha}. Values are the mean counts of bound cells in 0.2 mm2. Error bars represent SD. A representative experiment of 4 similar experiments is presented.



View larger version (19K):
[in this window]
[in a new window]
 
Figure 4. 8-Iso-PGF2{alpha}–triggered adhesion is blocked by PTx pretreatment. Eighteen-well glass slides were coated with human fibrinogen. Neutrophils were pretreated with 500 ng/mL PTx for 2 hours at 37°C and then stimulated at 37°C for 3 minutes with buffer, with no agonist, or with 100 nmol/L fMLP or with 20 µmol/L 8-iso-PGF2{alpha}. Values are the mean counts of bound cells in 0.2 mm2. Error bars represent SD. A representative experiment of 3 similar experiments is presented.

The previous data suggest that 8-iso-PGF2{alpha} is a highly selective neutrophil agonist with respect to integrin activation and dependent adhesion. Notably, 8-iso-PGF2{alpha} did not trigger binding to ICAM-1, and this excludes activation of the ß2-integrin CD11a/CD18 (leukocyte function-associated antigen, LFA-1). In contrast, 8-iso-PGF2{alpha} triggered adhesion to fibrinogen, thus suggesting the activation of the ß2-integrins CD11b/CD18 and CD11c/CD18, which are both receptors for fibrinogen. To investigate the relative contributions of CD11b/CD18 and CD11c/CD18, we carried out adhesion assays in the presence of blocking monoclonal antibodies. As shown in Figure 5Down, anti-CD11a/CD18 antibody did not block 8-iso-PGF2{alpha}–triggered adhesion to fibrinogen, as expected. In contrast, anti-CD11b/CD18 and anti-CD11c/CD18 blocked triggered adhesion, with an average inhibition of {approx}65% and 45%, respectively. Thus, CD11b/CD18 and CD11c/CD18 play a cooperative role in triggering of adhesion to fibrinogen by 8-iso-PGF2{alpha}. This was further confirmed by the capability of IB4, an anti-CD18 common chain blocking monoclonal antibody, to completely prevent induced adhesion (data not shown). The efficacy of the monoclonal antibodies used was confirmed each time by their capability to prevent fMLP-triggered rapid adhesion to fibrinogen as well as to ICAM-1. We conclude that 8-iso-PGF2{alpha} stimulates rapid human neutrophil adhesion to fibrinogen by rapid triggering of both the ß2-integrins CD11b/CD18 and CD11c/CD18.



View larger version (31K):
[in this window]
[in a new window]
 
Figure 5. 8-Iso-PGF2{alpha}–triggered adhesion to fibrinogen is mediated by CR3 and gp150/95. Eighteen-well glass slides were coated with human fibrinogen. Neutrophils were pretreated with anti-CR3 or anti-gp150/95 blocking monoclonal antibodies and then stimulated at 37°C for the 3 minutes with buffer, with no agonist, or with 100 nmol/L fMLP or with 1 or 20 µmol/L 8-iso-PGF2{alpha}. Values are the mean counts of bound cells in 0.2 mm2. Error bars represent SD. A representative experiment of 3 similar experiments is presented.


*    Discussion
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
up arrowResults
*Discussion
down arrowReferences
 
Oxidative stress is able to trigger the generation of biologically active substances, such as products of lipid peroxidation, which have been suggested to play a central role in the pathogenesis of many chronic diseases and particularly in atherosclerosis. F2-Isoprostanes are a new family of PGF2{alpha} isomers. They are produced mainly by a cyclooxygenase-independent oxidative modification of arachidonic acid normally present in all cell membranes, phospholipids, and plasma LDLs. 8-Iso-PGF2{alpha}, one of the best known F2-isoprostanes, was recently shown to be a specific, chemically stable, and quantitative marker of oxidant stress in vivo.1 Importantly, 8-iso-PGF2{alpha} was shown to be a vasoactive mediator, a mitogen, and a platelet activator.9 10 11 Nonetheless, the real significance of F2-isoprostanes as biological mediators remains to be established, especially in the context of the highly regulated multistep process of leukocyte–endothelial cell interaction, which is critical to the inflammatory response. Neutrophils are major players in the pathogenesis of ischemia-reperfusion injury, and their adherence to vascular endothelium is one of the earliest steps in this pathogenetic process leading to reperfusion damage23 and in the development of restenosis after angioplasty.24

In the present report, we investigated the potential relationship between isoprostanes and leukocyte proadhesive activities. From our results, the following conclusions can be drawn: (1) 8-iso-PGF2{alpha} triggers a PTx-sensitive signaling pathway in human neutrophils leading to rapid integrin activation; (2) 8-iso-PGF2{alpha} is likely to exert its effects on neutrophils via the TP; (3) integrin activation is restricted to the ß2-integrins CD11b/CD18 (CR3) and CD11c/CD18 (gp150/95) and supports binding to fibrinogen but not to ICAM-1; (4) 8-iso-PGF2{alpha} does not trigger integrin activation in monocytes and lymphocytes; and (5) the signaling capabilities of 8-iso-PGF2{alpha} appear to be restricted and selective, because it does not induce LFA-1 activation, chemotaxis, or NADPH-oxidase activity.

This study aimed to investigate the functional activity of 8-iso-PGF2{alpha} on leukocytes. 8-Iso-PGF2{alpha} appears to have the characteristics of the classic neutrophil chemoattractant, because it triggers rapid integrin activation through a PTx-sensitive signaling pathway, which suggests the involvement of a 7-spanning region receptor linked to heterotrimeric GTP-binding proteins of the Gi family. Furthermore, other compounds structurally related to 8-iso-PGF2{alpha}, such as 8-iso-PGF3{alpha} and PGF2{alpha} and U46619, have shown similar capability, thus suggesting that triggering of rapid neutrophil adhesion may be a common feature of some eicosanoids and isoeicosanoids. Because in our study the TP antagonist SQ29,548 was able to inhibit 8-iso-PGF2{alpha}– and U46619-triggered neutrophil adhesion in a dose-dependent manner, this indicates that 8-iso-PGF2{alpha} may act as a ligand for TP, a receptor that has been shown to be coupled to G proteins.25 This is in agreement with the findings of other authors who recently demonstrated that 8-iso-PGF2{alpha} acts as a vasoconstrictor and modulator of platelet function via activation of the TP in vivo in the mouse as well as in vitro.10 11 25 However, our data do not automatically exclude the existence of distinct and specific isoprostane receptors.

The functional activity of 8-iso-PGF2{alpha}, in contrast to other neutrophil chemoattractants, such as fMLP, leukotriene B4, C5a, platelet-activating factor, and interleukin-8, appears to be very selective. Indeed, 8-iso-PGF2{alpha} does not direct chemotaxis or trigger the release of oxygen free radicals. Moreover, and importantly, 8-iso-PGF2{alpha} stimulates neutrophil adhesion to fibrinogen but not to ICAM-1. This last finding is unexpected and of particular interest. Indeed, if this result excludes, de facto, the activation of CD11a/CD18, it also should rule out the involvement of CD11b/CD18, which is also a complementary ICAM-1 receptor able to mediate adhesion to ICAM-1. CD11b/CD18 activation by 8-iso-PGF2{alpha}, however, is confirmed by the capability of anti-CD11b/CD18–blocking monoclonal antibodies to partially prevent triggered adhesion to fibrinogen. From these data, we conclude that 8-iso-PGF2{alpha} activates a very restricted signaling pathway that selectively triggers a limited set of CD11b/CD18 functional modifications that in turn support interaction with fibrinogen but not with ICAM-1. Although unusual, these data are not completely surprising. Indeed, other classic neutrophil chemoattractants, such as leukotriene B4, platelet-activating factor, C5a, interleukin-8, and fMLP, also display a high degree of heterogeneity with respect to adhesion, chemotaxis, and triggering of free-radical release. This is probably due to quantitative differences in the signaling pathways, which are modulated by a combination of still not completely understood mechanisms, such as receptor affinity, homologous desensitization, agonist stability, number of receptors, and affinity for intracellular downstream effectors. All these regulatory factors are, at present, not defined in the case of 8-iso-PGF2{alpha} signaling capability, and their identification will represent an obvious major area of investigation.

Notably, 8-iso-PGF2{alpha} triggers activation of ß2-integrin CD11c/CD18, which has been shown to induce neutrophil respiratory burst on interaction with immobilized fibrinogen.26 Thus, 8-iso-PGF2{alpha} could amplify oxidative stress by triggering CD11c/CD18-mediated activation of NADPH-oxidase and the subsequent release of oxygen free radicals. Interestingly, the proadhesive activity of 8-iso-PGF2{alpha} is restricted only to neutrophils, because it does not trigger adhesion in monocytes and lymphocytes. Together, our findings suggest that 8-iso-PGF2{alpha} is a peculiar proinflammatory agonist, being selective at the level of induced phenomenon, integrin type, integrin ligand, and cell type.

The results of the present study may be of clinical relevance. F2-Isoprostanes are significantly elevated in human carotid atherosclerotic plaques and coronary arteries isolated from patients with coronary heart disease.27 It has been demonstrated that during acute coronary reperfusion, there is a dramatic increase of 8-iso-PGF2{alpha} released by the fissured plaque that peaks at 15 minutes after global myocardial reperfusion.2 Reperfusion of ischemic tissue is associated with an acute inflammatory response that may further exacerbate vascular and tissue damage. This vascular reperfusion injury is mediated largely by free radicals and neutrophils through specific interactions between adhesion molecules on the endothelium, platelets, and neutrophils, an interaction that precedes myocyte injury.23 Compelling evidence from a variety of animal models indicates that blockade of neutrophil adhesion to endothelium attenuates ischemia-reperfusion injury,28 29 further highlighting the importance of these inflammatory cells in this acute pathogenetic process.

Isoprostanes are also increased in association with such risk factors as hypercholesterolemia7 and diabetes mellitus,4 which are relevant in the development of ischemic vascular disease. Notably, it has been demonstrated that hypercholesterolemia28 and diabetes mellitus,29 well-known risk factors for the progression and destabilization of atherosclerotic plaque, are associated with an inflammatory response that renders the tissues more vulnerable to ischemic episodes. Mounting evidence indicates that metabolic conditions associated with these risk factors may also exacerbate the vulnerability of the microvasculature to the deleterious effects of ischemia and reperfusion.29 30 A common feature of the negative effects of these risk factors on endothelial function during ischemia-reperfusion is the enhanced oxidant stress.

Furthermore, emerging experimental evidence indicates that neutrophils may also be central to intimal hyperplasia after mechanical arterial injury, which leads to restenosis.30 Indeed, in CD11b/CD18-deficient mice, neutrophil recruitment in vascular repair after PTCA is reduced, thus preventing neointimal thickening.31 This further supports the role of integrin-dependent triggering of neutrophil adhesion in intimal hyperplasia. Interestingly, despite standard aspirin and heparin therapy, leukocyte activation and platelet adherence still occur after coronary angioplasty.32 In contrast, experimental data and preliminary clinical studies have suggested that antioxidants, such as vitamin E, may prevent restenosis after angioplasty.33 Furthermore, in a large, double-blind, randomized trial, probucol, a well-known antioxidant, improved vascular remodeling after PTCA.34 Notably, it has been demonstrated that 8-iso-PGF2{alpha} is increased after coronary angioplasty35 and that vitamin E is able to suppress 8-iso-PGF2{alpha} generation in vivo.4 36 We hypothesize that the beneficial effects of antioxidants in the prevention of restenosis after PTCA may be partly related to the prevention of isoprostane generation. Furthermore, a second line of emergent pharmacological therapy in the acute coronary syndromes, in the ischemia/reperfusion syndromes, and in the prevention of restenosis after PTCA could be the use of TP antagonists in association with cyclooxygenase inhibitors. Notably, it was recently demonstrated that blockade of TP receptors may inhibit atherosclerosis via the prevention of cellular events stimulated by eicosanoids other than thromboxane A2,37 and that could be even more important in those clinical conditions in which large amounts of isoprostanes are released into the blood stream.

In conclusion, our data demonstrate, for the first time, that 8-iso-PGF2{alpha} modulates rapid and selective proadhesive activity in polymorphonuclear neutrophils. Notably, the 8-iso-PGF2{alpha} biological activity that has been demonstrated here on neutrophils and previously on platelets and muscle cells9 10 11 could be shared by the other related families of isoeicosanoids simultaneously generated by oxidative stress.1 This is consistent with the hypothesis of a general role of isoprostanes as modulators of proinflammatory cells. Inhibition of F2-isoprostane generation and activity could be a novel target for drug therapy in clinical conditions in which oxidative stress and neutrophil activation coexist.


*    Acknowledgments
 
The present study was supported by a grant from Italian Ministry of University and Research (fondi 60%, University of Verona, Italy); by cofinanziamento MURST and University of Verona, Progetto Sanità 1996/97; by Fondazione Cassa di Risparmio; and by Istituto Superiore di Sanità (progetto Sclerosi Multipla).


*    Footnotes
 
Reprint requests to Prof Alessandro Lechi, Department of Biomedical and Surgical Sciences, Medicina Interna C, Policlinico GB Rossi, Piazzale LA Scuro, 37134 Verona, Italy.

Received October 19, 2000; accepted October 23, 2000.


*    References
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
up arrowResults
up arrowDiscussion
*References
 
1. Lawson JA, Rokach J, FitzGerald GA. Isoprostanes: formation, analysis and use as indices of lipid peroxidation in vivo. J Biol Chem. 1999;274:24441–24444.[Free Full Text]

2. Delanty N, Reilly MP, Pratico D, Lawson JA, McCarthy JF, Wood AE, Ohnishi ST, Fitzgerald DJ, FitzGerald GA. 8-Epi-PGF2{alpha} generation during coronary reperfusion: a potential quantitative marker of oxidant stress in vivo. Circulation. 1997;95:2492–2499.[Abstract/Free Full Text]

3. Carpenter CT, Price PV, Christman BW. Exhaled breath condensate isoprostanes are elevated in patients with acute lung injury or ARDS. Chest. 1998;114:1653–1659.[Abstract/Free Full Text]

4. Davi G, Ciabattoni G, Consoli A, Mezzetti A, Falco A, Santarone S, Pennese E, Vitacolonna E, Bucciarelli T, Costantini F, Capani F, Patrono C. In vivo formation of 8-iso-prostaglandin F2{alpha} and platelet activation in diabetes mellitus: effects of improved metabolic control and vitamin E supplementation. Circulation. 1999;99:224–229.[Abstract/Free Full Text]

5. Pratico D, Basili S, Vieri M, Cordova C, Violi F, Fitzgerald GA. Chronic obstructive pulmonary disease is associated with an increase in urinary levels of isoprostane F2alpha-III, an index of oxidant stress. Am J Respir Crit Care Med. 1998;158:1709–1714.[Abstract/Free Full Text]

6. Morrow JD, Frei B, Longmire AW, Gaziano JM, Lynch SM, Shyr Y, Strauss WE, Oates JA, Roberts LJ II. Increase in circulating products of lipid peroxidation (F2-isoprostanes) in smokers: smoking as a cause of oxidative damage. N Engl J Med. 1995;332:1198–1203.[Abstract/Free Full Text]

7. Reilly MP, Pratico D, Delanty N, DiMinno G, Tremoli E, Rader D, Kapoor S, Rokach J, Lawson J, FitzGerald GA. Increased formation of distinct F2 isoprostanes in hypercholesterolemia. Circulation. 1998;98:2822–2828.[Abstract/Free Full Text]

8. Voutilainen S, Morrow JD, Roberts LJ II, Alfthan G, Alho H, Nyyssonen K, Salonen JT. Enhanced in vivo lipid peroxidation at elevated plasma total homocysteine levels. Arterioscler Thromb Vasc Biol. 1999;19:1263–1266.[Abstract/Free Full Text]

9. Takahashi K, Nammour TM, Fukunaga M, Ebert J, Morrow JD, Roberts LJH, Hoover RL, Badr KF. Glomerular actions of a free radical-generated novel prostaglandin, 8-epi-prostaglandin F2 alpha, in the rat: evidence for interaction with thromboxane A2 receptors. J Clin Invest. 1992;90:136–141.

10. Pratico D, Smyth EM, Violi F, FitzGerald GA. Local amplification of platelet function by 8-epi prostaglandin F2alpha is not mediated by thromboxane receptor isoforms. J Biol Chem. 1996;271:14916–14924.[Abstract/Free Full Text]

11. Minuz P, Andrioli G, Degan M, Gaino S, Ortolani R, Tommasoli R, Zuliani V, Lechi A, Lechi C. The F2-isoprostane 8-epiprostaglandin F2{alpha} increases platelet adhesion and reduces the antiadhesive and antiaggregatory effects of NO. Arterioscler Thromb Vasc Biol. 1998;18:1248–1256.[Abstract/Free Full Text]

12. Butcher EC, Williams M, Youngman K, Rott L, Briskin M. Lymphocyte trafficking and regional immunity. Adv Immunol. 1999;72:209–253.[Medline] [Order article via Infotrieve]

13. Baggiolini M, Dewald B, Thelen M. Effects of PAF on neutrophils and mononuclear phagocytes. Prog Biochem Pharmacol. 1988;22:90–105.[Medline] [Order article via Infotrieve]

14. Palmblad J, Malmsten CL, Uden AM, Radmark O, Engstedt L, Samuelsson B. Leukotriene B4 is a potent and stereospecific stimulator of neutrophil chemotaxis and adherence. Blood. 1981;58:658–661.[Abstract/Free Full Text]

15. Schiffmann E, Corcoran BA, Wahl SM. N-Formylmethionyl peptides as chemoattractants for leucocytes. Proc Natl Acad Sci U S A. 1975;72:1059–1062.[Abstract/Free Full Text]

16. Shin HS, Snyderman R, Friedman E, Mellors A, Mayer MM. Chemotactic and anaphylatoxic fragment cleaved from the fifth component of guinea pig complement. Science. 1968;162:361–363.[Abstract/Free Full Text]

17. Ross R, Atherosclerosis: an inflammatory disease. N Engl J Med. 1999;340:115–126.[Free Full Text]

18. Boyum A. Isolation of mononuclear cells and granulocytes from human blood: isolation of mononuclear cells by one centrifugation, and of granulocytes by combining centrifugation and sedimentation at 1 g. Scand J Clin Lab Invest Suppl. 1968;97:77–89.[Medline] [Order article via Infotrieve]

19. Ulmer AJ, Flad HD. Discontinuous density gradient separation of human mononuclear leucocytes using Percoll as gradient medium. J Immunol Methods. 1979;30:1–10.[Medline] [Order article via Infotrieve]

20. Laudanna C, Campbell JJ, Butcher EC. Role of Rho in chemoattractant-activated leukocyte adhesion through integrins. Science. 1996;271:981–983.[Abstract]

21. Laudanna C, Mochly-Rosen D, Liron T, Constantin G, Butcher EC. Evidence of zeta protein kinase C involvement in polymorphonuclear neutrophil integrin-dependent adhesion and chemotaxis. J Biol Chem. 1998;273:30306–30315.[Abstract/Free Full Text]

22. Valletta EA, Berton G. Desensitization of macrophage oxygen metabolism on immobilized ligands: different effect of immunoglobulin G and complement. J Immunol. 1987;138:4366–4373.[Abstract]

23. Arnould T, Michiels C, Remacle J. Increased PMN adherence on endothelial cells after hypoxia: involvement of PAF, CD18/CD11b, and ICAM-1. Am J Physiol. 1993;264:C1102–C1110.[Abstract/Free Full Text]

24. Inoue T, Sakai Y, Hoshi K, Yaguchi I, Fujito T, Morooka S. Lower expression of neutrophil adhesion molecule indicates less vessel wall injury and might explain lower restenosis rate after cutting balloon angioplasty. Circulation. 1998;97:2511–2518.[Abstract/Free Full Text]

25. Audoly LP, Rocca B, Fabre JE, Koller BH, Thomas D, Loeb AL, Coffman TM, FitzGerald GA. Cardiovascular responses to the isoprostanes iPF2{alpha}-III and iPE2-III are mediated via the thromboxane A2 receptor in vivo. Circulation. 2000;101:2833–2840.[Abstract/Free Full Text]

26. Berton G, Laudanna C, Sorio C, Rossi F. Generation of signals activating neutrophil functions by leukocyte integrins: LFA-1 and gp150/95, but not CR3, are able to stimulate the respiratory burst of human neutrophils. J Cell Biol. 1992;116:1007–1017.[Abstract/Free Full Text]

27. Pratico D, Iuliano L, Mauriello A, Spagnoli L, Lawson JA, Rokach J, Maclouf J, Violi F, FitzGerald GA. Localization of distinct F2-isoprostanes in human atherosclerotic lesions. J Clin Invest. 1997;100:2028–2034.[Medline] [Order article via Infotrieve]

28. Kurose I, Wolf RE, Grisham MB, Granger DN. Hypercholesterolemia enhances oxidant production in mesenteric venules exposed to ischemia/reperfusion. Arterioscler Thromb Vasc Biol. 1998;18:1583–1588.[Abstract/Free Full Text]

29. Panes J, Kurose I, Rodriguez-Vaca D, Anderson DC, Miyasaka M, Tso P, Granger DN. Diabetes exacerbates inflammatory responses to ischemia-reperfusion. Circulation. 1996;93:161–167.[Abstract/Free Full Text]

30. Roque M, Fallon JT, Badimon JJ, Zhang WX, Taubman MB, Reis ED. Mouse model of femoral artery denudation injury associated with the rapid accumulation of adhesion molecules on the luminal surface and recruitment of neutrophils. Arterioscler Thromb Vasc Biol. 2000;20:335–342.[Abstract/Free Full Text]

31. Simon DI, Chen Z, Seifert P, Edelman ER, Ballantyne CM, Rogers C. Decreased neointimal formation in Mac-1(-/-) mice reveals a role for inflammation in vascular repair after angioplasty. J Clin Invest. 2000;105:293–300.[Medline] [Order article via Infotrieve]

32. Schwartz L, Bourassa MG, Lesperance J, Aldrige HE, Kazim F, Salvatori VA, Henderson M, Bonan R, David PR. Aspirin and dipyridamole in the prevention of restenosis after percutaneous transluminal coronary angioplasty. N Engl J Med. 1988;318:1714–1719.[Abstract]

33. Lafont AM, Chai YC, Cornhill JF, Whitlow PL, Howe PH, Chisolm GM. Effect of alpha-tocopherol on restenosis after angioplasty in a model of experimental atherosclerosis. J Clin Invest. 1995;95:1018–1025.

34. Tardif JC, Cote G, Lesperance J, Bourassa M, Lambert J, Doucet S, Bilodeau L, Nattel S, de Guise P. Probucol and multivitamins in the prevention of restenosis after coronary angioplasty. Multivitamins and Probucol Study Group. N Engl J Med. 1997;337:365–372.[Abstract/Free Full Text]

35. Reilly MP, Delanty N, Roy L, Rokach J, Callaghan PO, Crean P, Lawson JA, FitzGerald GA. Increased formation of the isoprostanes IPF2{alpha}-I and 8-epi-prostaglandin F2{alpha} in acute coronary angioplasty: evidence for oxidant stress during coronary reperfusion in humans. Circulation. 1997;96:3314–3320.[Abstract/Free Full Text]

36. Pratico D, Tangirala RK, Rader DJ, Rokach J, FitzGerald GA. Vitamin E suppresses isoprostane generation in vivo and reduces atherosclerosis in apoE-deficient mice. Nat Med. 1998;4:1189–1192.[Medline] [Order article via Infotrieve]

37. Cayatte AJ, Du Y, Oliver-Krasinski J, Lavielle G, Verbeuren TJ, Cohen RA. The thromboxane receptor antagonist S18886 but not aspirin inhibits atherogenesis in apo E-deficient mice: evidence that eicosanoids other than thromboxane contribute to atherosclerosis. Arterioscler Thromb Vasc Biol. 2000;20:1724–1728.[Abstract/Free Full Text]




This article has been cited by other articles:


Home page
J BiochemHome page
S. Acin, M. A. Navarro, J. M. Arbones-Mainar, N. Guillen, A. J. Sarria, R. Carnicer, J. C. Surra, I. Orman, J. C. Segovia, R. d. l. Torre, et al.
Hydroxytyrosol Administration Enhances Atherosclerotic Lesion Development in Apo E Deficient Mice
J. Biochem., September 1, 2006; 140(3): 383 - 391.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
M. C. Bowers, K. A. Katki, A. Rao, M. Koehler, P. Patel, A. Spiekerman, D. J. DiPette, and S. C. Supowit
Role of Calcitonin Gene-Related Peptide in Hypertension-Induced Renal Damage
Hypertension, July 1, 2005; 46(1): 51 - 57.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Endocrinol. Metab.Home page
G. Desideri, M. De Simone, L. Iughetti, T. Rosato, M. L. Iezzi, M. C. Marinucci, V. Cofini, G. Croce, G. Passacquale, S. Necozione, et al.
Early Activation of Vascular Endothelial Cells and Platelets in Obese Children
J. Clin. Endocrinol. Metab., June 1, 2005; 90(6): 3145 - 3152.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Endocrinol. Metab.Home page
C. Bell, P. P. Jones, and D. R. Seals
Oxidative Stress Does Not Modulate Metabolic Rate or Skeletal Muscle Sympathetic Activity with Primary Aging in Adult Humans
J. Clin. Endocrinol. Metab., October 1, 2003; 88(10): 4950 - 4954.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
L. Fontana, C. Giagulli, L. Cominacini, A. F. Pasini, P. Minuz, A. Lechi, A. Sala, and C. Laudanna
{beta}2 Integrin-Dependent Neutrophil Adhesion Induced by Minimally Modified Low-Density Lipoproteins Is Mainly Mediated by F2-Isoprostanes
Circulation, November 5, 2002; 106(19): 2434 - 2441.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
J. D. Krier, M. Rodriguez-Porcel, P. J. M. Best, J. C. Romero, A. Lerman, and L. O. Lerman
Vascular responses in vivo to 8-epi PGF2alpha in normal and hypercholesterolemic pigs
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R303 - R308.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
M.J. Sampson, I.R. Davies, J.C. Brown, K. Ivory, and D.A. Hughes
Monocyte and Neutrophil Adhesion Molecule Expression During Acute Hyperglycemia and After Antioxidant Treatment in Type 2 Diabetes and Control Patients
Arterioscler Thromb Vasc Biol, July 1, 2002; 22(7): 1187 - 1193.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Crit. Care Med.Home page
J.-L. CRACOWSKI, C. CRACOWSKI, G. BESSARD, J.-L. PEPIN, J. BESSARD, C. SCHWEBEL, F. STANKE-LABESQUE, and C. PISON
Increased Lipid Peroxidation in Patients with Pulmonary Hypertension
Am. J. Respir. Crit. Care Med., September 15, 2001; 164(6): 1038 - 1042.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
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 arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fontana, L.
Right arrow Articles by Laudanna, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fontana, L.
Right arrow Articles by Laudanna, C.
Related Collections
Right arrow Pathophysiology
Right arrow Ischemic biology - basic studies
Right arrow Acute coronary syndromes
Right arrow Oxidant stress