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 Magazine, H. I.
Right arrow Articles by Stefano, G. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Magazine, H. I.
Right arrow Articles by Stefano, G. B.
Right arrowPubmed/NCBI databases
*Gene*GEO Profiles
*HomoloGene*UniGene
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*(D)-PENICILLAMINE
*NITRIC OXIDE
The Journal of Immunology, 2000, 165: 102-107.
Copyright © 2000 by The American Association of Immunologists

Rebound from Nitric Oxide Inhibition Triggers Enhanced Monocyte Activation and Chemotaxis1

Harold I. Magazine2,*,{dagger}, Jungshan Chang*, Yannick Goumon{dagger} and George B. Stefano{dagger}

* Department of Biology, Queens College and the Graduate School of the City University of New York, Flushing, NY 11367; and {dagger} Multidisciplinary Center for the Study of Aging, Neuroscience Research Institute, State University of New York/College at Old Westbury, Old Westbury, NY 11568


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Exposure of human peripheral blood monocytes to the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) resulted in a rapid shift in cellular conformation of spontaneously activated cells from ameboid to round. The population of activated cells, ~7.1 ± 1.2%, was reduced 7-fold to 1.1 ± 0.4% following 0.5 h exposure to SNAP. Observation of monocytes for 6 h demonstrated a gradual release from NO inhibition initiating at 2.5 h following SNAP treatment and a period of hyperactivity that was maximal at ~5 h following SNAP exposure. During the rebound from the NO inhibition phase, there was a significant increase in the population of activated monocytes and an increased responsiveness to chemotactic agents such as IL-1, IL-8, and fMLP relative to that of cells treated with the chemotactic agents alone. Conformational changes induced by SNAP were associated with a reduction in F-actin and loss of filopodial extension. The loss and recovery of F-actin staining paralleled changes in cell activity, suggesting that NO may alter cellular activity by modulation of cytoskeletal actin. These data taken together suggest that inhibition of monocyte activity by NO results in an excitatory phase observed subsequent to release from NO inhibition and increased sensitivity to chemotactic agents. We propose that this rebound from NO inhibition may provide increased immunosurveillance to rectify immunological problems that have been encountered during the period of inhibition.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Production of NO may be associated with induction of immune and vascular dysfunction (1, 2, 3, 4, 5, 6, 7). Indeed, direct cytotoxic effects of NO on inflammatory cells and vascular tissue has been widely reported (1, 3, 4). In contrast to these findings, recent studies have emerged that demonstrate beneficial effects of NO on immune and vascular function (5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22). The apparent discrepancy in NO action may be the result of activation of different NO synthase (NOS)3 isoforms by the various experimental conditions employed in the above studies or the activation state of the cell before NOS activation (14, 23). In this regard, induction of inducible NOS (iNOS)-coupled NO release (e.g., by treatment with IFN {gamma} and LPS) was abrogated by prior constitutive NOS (cNOS) activation (23), suggesting that cNOS-coupled NO release can markedly alter chemokine immunomodulation.

Recent reports have demonstrated a link between NO and cell migration. In this regard, monocyte chemotaxis was reduced in the presence of NOS inhibitors, suggesting a requirement of NO production in cell migration, whereas NO has also been demonstrated to impair chemotaxis (24, 25) and inhibit cell mobility (26). In the present report, we demonstrate that transient exposure of monocytes to NO induces rapid changes in cell conformation and inhibition of cell mobility and chemotaxis. Following this period of repression, the cell rebounds from inhibition as noted by a marked increase in monocyte activation and responsiveness to chemotaxic agents. Thus, the apparent contradiction in the reported effects of NO on chemotaxis in the literature may be resolved by the demonstration in this report of a biphasic effect of NO on cell chemotaxis. We surmise that the enhanced responsiveness of inflammatory cells observed following NO-induced inhibition might be an attempt to attenuate pathological conditions that may have progressed during the inhibitory phase but also may serve as a mechanism to modulate responsiveness to chemokine stimulation.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Monocyte preparation

The leukocyte fraction of human blood was obtained from the Long Island Blood Services (Melville, Long Island, NY) and enriched for monocytes using the OptiPrep proceedure. OptiPrep separation yields monocyte populations that are >95% pure and have reduced T lymphocyte contamination (27). Indeed, contaminating cell populations were undetectable by visual inspection. Cells were washed three times in RPMI 1640 medium (RPMI 1640, 25 mM HEPES, 5% CO2, pH 7.4, Grand Island Biological, Grand Island, NY) and diluted to a final concentration of ~400 cells/ml. Cells were placed on a slide previously coated with 0.1% BSA within a ring of petrolatum gel (Sigma, St. Louis, MO) and maintained at 37°C using a stage warmer.

Monocyte activation and chemotaxis

Cell morphology was visualized using phase-contrast optics and a Nikon TE300 inverted microscope (Nikon, Melville, NY) prepared and maintained as described above. To evaluate the direct effects of NO on cell activity, cells were treated with the NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP) and evaluated for 6 h. SNAP depleted of NO, S-acetyl-DL-penicillamine (SAP), in the presence of 10 µM 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a potent NO scavenger, was evaluated to confirm the role of NO in SNAP modulation of cellular activity. To evaluate the influence of NO exposure on subsequent activation of cells with chemotactic agents, cells were exposed to SNAP for 2 or 5 h, whereupon they were treated with cytokines (IL-1 or IL-8) or fMLP. The cells were allowed to respond to the chemotactic agent for 10 min, whereupon cell activation and alignment was evaluated. The time periods following SNAP exposure chosen for these studies corresponded to periods where maximal SNAP-induced cell inactivation (2 h) and rebound from NO inhibition or hyperactivation (5 h) was observed.

Changes in monocyte conformation were evaluated using commercial cell analysis software (American Innovision Analysis System, Tracksh Program, San Diego, CA). Changes in cellular conformation ranging from inactive-rounded (diameter range 10–14 µm) to active-amoeboid (diameter > 14 µm) were determined by measurements of cellular area and perimeter and were expressed mathematically by using the form-factor formula of the American Innovision Analysis System: AC/AT = (LT/LC)2, in which AT is the area of a circle with the same perimeter as that of the given cell, and AC and LC are the actual area and perimeter of the cell (28). The lower the number, the higher the perimeter and the more amoeboid the cellular shape. The degree of cellular activation was determined as noted elsewhere (26, 29, 30). Briefly, under phase contrast optics, round cells appear light yellow and amoeboid cells dark. The system, manually tuned, identifies these color differences (bright for round cells and gray for amoeboid cells) and the proportion of each is used as an index of activation. Cellular debris that exhibits an area smaller than 30 µm2 or larger than 700 µm2 is automatically ignored.

Chemotaxis was evaluated using commercial cell analysis software (American Innovision, San Diego, CA). Cells that are responding to a chemotactic agent exhibit increased velocity and a directed migration toward the stimulating agent. Monocytes exhibiting a chemotactic response have increased cellular velocity and a parallel alignment to the concentration gradient of the chemotactic agent, whereas, in contrast, a chemokinetic response has no increase in alignment to the stimulating agent. The axis of movement of individual cells is measured where the axis is defined as the minimum moment, or location in a cell, that exhibits minimum rotation around a point and is calculated from the arc tangent of multiple moments, including the centroid location of a cell (30). In previous studies, ~30–40% of monocytes were found to align themselves in a parallel manner with the concentration gradient of known chemotactic agents (30). Approximately 30–40 activated cells were observed per 400-µm viewing area, and four areas were observed per slide. To control for the influence of spontaneous monocyte activation, parallel controls were run for each time period in all experiments. Experiments were repeated three times, and the data presented are mean ± SEM of a single experiment.

Nitric oxide

NO production was evaluated using an NO-specific amperometric probe (World Precision Instruments, Sarasota, FL) exactly as described (14, 21). The probe was placed into RPMI 1640 maintained at 37°C and allowed to achieve a stable baseline, whereupon SNAP was added to the solution to a final concentration of 1 µM, and NO generation obtained by the decomposition of SNAP was evaluated in real-time with a DUO 18 computer data-acquisition system. There was no NO generation obtained by decomposition of SAP (not shown).

Cytoskeletal actin

Monocytes (2 x 104 cells) were treated with RPMI 1640 or 1 µM SNAP and placed on a BSA-coated coverslip followed by incubation at 37°C in 5% CO2 for 0.5–5 h. Cells were then washed twice with PBS and fixed with a solution of 0.025% glutaraldehyde/0.25% formaldehyde for 10 min at 22°C. Cells were then washed three times with PBS, permeabilized with 0.5% Triton X-100 for 5 min, and evaluated for F-actin using Alexa 488 phalloidin (Molecular Probes, Eugene, OR). Samples were imaged using a quantitative confocal microscopy system (Meridian Instruments, Okemos, MI) coupled to an Olympus microscope and a x100 oil immersion objective with a fixed pinhole setting of 40 µM.

Statistics

The Student’s t test was employed to compare treatment groups, and a value of p < 0.05 was considered to be statistically significant.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Macrophages isolated from human blood typically display a low level (6–9%) of spontaneous activation (29, 31). Activated cells are characterized as cells exhibiting an amoeboid conformation (shape factor < 0.5) and random movement of ~0.1 µm/s, a relatively low velocity (29, 31). Exposure of macrophages to the NO donor, SNAP, resulted in a rapid shift in the conformation of activated cells to the nonmotile, rounded conformation (Fig. 1GoA). A significant reduction in the activated monocyte population was observed following SNAP exposure and persisted for >2.5 h. At time points >2.5 h, there was a gradual increase in the population of activated macrophages culminating at 5 h with an activation level ~2.5-fold greater than that of untreated controls. Activated cells evaluated at 5 h were significantly more amoeboid and motile, yet in the absence of inflammatory mediators (e.g., fMLP or IL-1, IL-8, below) a gradual return to the control level of activation and motility was observed. Monocyte activation at periods of inactivation (2 h) and hyperactivation (5 h) were chosen for further study. A significant reduction in the population of activated monocytes (from 6.5 ± 1.2% to 0.2 ± .1%, p < 0.001) was observed 2 h following SNAP treatment (Fig. 1GoB). Monocytes treated with SAP, SNAP depleted of NO generation, were indistinguishable from that of untreated controls. In contrast, SNAP failed to reduce the population of activated monocytes in the presence of the potent NO scavenger, carboxy-PITC, suggesting that NO is required for the SNAP-induced cell inactivation. A 3-fold increase in monocyte activation was observed 5 h following SNAP exposure relative to untreated controls. In contrast, monocyte activation following treatment with SAP or SNAP in the presence of carboxy-PITC was similar to control. These data taken together suggest that SNAP can block as well as stimulate monocyte activation, and NO generation appears to be required for SNAP modulation of cell activation.



View larger version (24K):
[in this window]
[in a new window]
  		FIGURE 1. Effects of SNAP on monocyte activation. Changes in activation of monocytes, untreated (•) or exposed to the NO donor, SNAP (1 µM; {circ}), was evaluated over 6 h. Activated cells were defined as monocytes that were moving and exhibiting a form factor value below 0.5 (A). Cells treated with SNAP for 2 h were significantly less activated relative to control cells, whereas activation at 5 h was marked increased. The effects of SNAP were studied further at time points where maximal inhibition (2 h) and hyperactivation (5 h) were observed (B). The effect of SNAP on monocyte activation was blocked in the presence of 10 µM carboxy-PTIO, whereas untreated cells were indistinguishable from that of SAP-treated cells. Data shown are the mean ± SEM of 40–50 cells. Statistical significance was determined by Students t test.

 
Direct measurement of NO using an NO-selective amperometric probe demonstrated an increase in NO release generated by SNAP decomposition that was maximal within ~10 min yet declined to undetectable levels within 90 min, indicating that the effects of NO on cell activation persist for several hours (Fig. 2Go). NO has been demonstrated to trigger the destabilization of cytoskeletal actin consistent with the potent changes in cellular conformation observed following treatment of macrophages with SNAP (Fig. 1Go). To evaluate the effects of SNAP on cytoskeletal actin, macrophages were treated with SNAP, and F-actin content was evaluated for 5 h using the specific F-actin stain phalloidin and quantitative confocal microscopy. The F-action content of macrophages treated with SNAP was markedly reduced relative to that of controls for 1 h following SNAP treatment (Fig. 3Go). However, 1.5 h following SNAP treatment a rapid recovery in F-actin content was observed with F-actin content surpassing that of controls 5 h following SNAP exposure. Confocal micrographs of monocytes demonstrate adoption of an ameboid actin cytoskeleton with numerous filopodia at 2 and 5 h but not 0.5 h following addition to the slide (Fig. 4Go). The F-actin content of the monocytes was markedly reduced following 0.5 h treatment with SNAP relative to that of controls. A marked recovery in F-actin staining was observed 1.5 h following SNAP treatment at a time point that paralleled the loss of NO generation as detected by the NO selective amperometric probe (Fig. 2Go). Despite the recovery of F-actin, 2 h following SNAP treatment monocytes remained rounded with intense F-actin staining localized to the cell periphery and a marked reduction in the number and intensity of staining of the filopodial array relative to that of controls (Fig. 4Go). In contrast, monocytes 5 h following SNAP treatment appeared ameboid with a marked increase in the number and intensity of staining of the filopodial extensions. These data taken together suggest that the F-actin content of the monocytes was reduced in the presence of NO, whereas the F-actin content but not cytoskeletal organization recovers rapidly upon a decline in NO concentration.



View larger version (11K):
[in this window]
[in a new window]
  		FIGURE 2. Evaluation of NO generation by SNAP decomposition. SNAP (1 µM) was added to RPMI 1640 and maintained at 37°C exactly as performed in the presence of cells (see Fig. 1Go above). NO concentrations were evaluated in real-time using a NO-selective amperometric probe. Data shown are the mean ± SEM of three experiments.

 


View larger version (15K):
[in this window]
[in a new window]
  		FIGURE 3. Effect of SNAP on cytoskeletal actin. Monocytes, untreated (•) or treated with SNAP ({circ}), were evaluated for F-actin content for a 5-h time period. Cells were evaluated by confocal microscopy using a pinhole setting of 40 µM. Data shown is the mean ± SEM of 20 cells and is representative of five experiments.

 


View larger version (80K):
[in this window]
[in a new window]
  		FIGURE 4. Effect of SNAP on cytoskeletal actin. Micrographs of control monocytes at 2 and 5 h but not 0.5 h exhibited ameboid conformation and numerous filopodial extensions. Monocytes treated with SNAP had little or no filopodial extensions at 2 h, whereas numerous filopodial extensions were observed at 5 h with an intensive increase in filopodial length and density of F-actin staining. Data shown are representative samples of five experiments.

 
Previous studies have suggested that NO can enhance as well as inhibit cell activation and chemotaxis, yet the mechanisms that account for this paradox remain poorly understood. Our data obtained using the NO donor SNAP demonstrates that NO can inhibit cell migration and activation for >2 h following NO exposure and triggers an increase in cell migration and activation 5 h following NO exposure. To evaluate the effects of NO on activation and chemotaxis, we measured cell responses to known chemotactic agents at time points where we observed maximal NO-induced inactivation and rebound from NO inhibition or hyperactivation (2 and 5 h following SNAP treatment, respectively). Macrophages exhibited a low level of spontaneous activation (6–7% of the total population) that was increased markedly 10 min following exposure to fMLP (Table IGo), consistent with previous reports (24, 25, 26, 30). In addition, significant chemotaxis toward fMLP was observed (Table IIGo), consistent with the known activity of this classical chemotactic agent (24, 25, 30). In contrast, treatment of macrophages with fMLP during the NO inhibition phase failed to result in an increase in cell activation (Fig. 4Go) or chemotaxis (Table IIGo), indicating potent immunosuppression by NO. Macrophages treated with fMLP during the hyperactivation phase responded with a significantly greater level of activation (Table IGo) and chemotaxis (Table IIGo) than that of cells treated with the fMLP alone. The chemokines, IL-1 and IL-8, also increased macrophage activation and chemotaxis. In a manner comparable to fMLP, chemokines were ineffective at stimulating cell activity during the NO-mediated inhibitory phase, whereas increased activation and chemotaxis was observed during the hyperactivation phase (Tables I and II).


View this table:
[in this window]
[in a new window]
  		Table I. Effect of SNAP on monocyte activation1

 

View this table:
[in this window]
[in a new window]
  		Table II. Effect of SNAP on monocyte chemotaxis1

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
In the present study, we have demonstrated that exposure of macrophages to NO results in potent rounding and immobilization of previously activated, migratory cells. We have determined previously that activated macrophages become round and immobile within 10 min of cNOS-coupled NO production (26, 29, 30, 31), consistent with our observations using the NO donor, SNAP, in the current report. Treatment of monocytes with SNAP resulted in profound inhibition of cell activation as assessed by conformation and migration. In addition, during this inhibition phase the cells were resistant to subsequent stimulation with diverse chemotactic agents including IL-1, IL-8, and f-MLP. Following this period of inhibition, monocytes treated with SNAP alone became hyperactivated and exhibited increased cytoskelatal organization, and a greater population of activated cells was observed relative to that of untreated controls. Of perhaps greater physiological importance is the observation that cells in the hyperactivation phase have an increased responsiveness to stimulating agents. These data suggest that exposure of cells to NO can modulate the immune response and NO may exert both inhibitory as well as stimulatory activity. Indeed these data may in part explain conflicting reports in the literature where NO has been reported to inhibit or stimulate cell activation and migration (24, 25, 26, 29, 30, 31, 32, 33).

The decay of SNAP into NO was evaluated. Direct measurement of NO levels using an NO-selective amperometric probe determined that NO levels generated by SNAP decomposition are maximal ~10 min following SNAP addition to the cell culture medium, yet decline to undetectable levels within 1.5 h. However, the impact of NO on cell activation, chemotaxis, and organization of cytoskeletal actin was observed for >5 h. These data demonstrate that the production of NO by SNAP decomposition provides immunomodulatory activity that endures well beyond the presence of the signal molecule and is consistent with previous work focused on cNOS immunoregulation. In this regard, monocytes exposed to morphine (26, 31), anandamide (26), thrombin (32), or endothelin (34) were demonstrated to produce 30–50 nM NO for 5–10 min, yet monocyte spreading and ameboid conformation was altered for >1 h. The effects of these ligands was abrogated by inhibition of NOS activity, demonstrating the important role of NO in modulation of cell activity (26, 31, 32). In contrast, NO levels generated by SNAP decomposition remained elevated for >1.5 h. Thus, it is likely that the rebound from NO inhibition following ligand-induced NO release may occur much more rapidly than that observed for SNAP. Indeed recovery of the activated conformation following morphine, anandamide, endothelin, or thrombin treatment was observed ~45 min to 1 h following agonist stimulation in previous studies (26, 32, 34). However, in these studies the signal transduction cascade induced by ligand-receptor interaction could not be resolved from that directly induced by NO released subsequent to receptor activation. The current report extends the observations of previous reports and demonstrates that NO may directly initiate events that lead to cellular inactivation and hyperactivation responses (Tables I and II).

In contrast to the inhibition observed for 2.5 h following SNAP exposure, our results also demonstrate increased mobility and activation following release from NO inhibition. NO exposure resulted in marked changes in macrophage activation and chemotaxis 4 h after the disappearance of detectable levels of NO in the culture medium, suggesting that NO may exert long-term effects on cell activation. Indeed the cellular activation and chemokinesis induced by IL-1 and IL-8 as well as fMLP was initially abrogated by prior exposure to NO yet was markedly increased 5 h following NO exposure (Tables I and II). Thus, the biological impact of transient NO exposure could be significantly greater than initially anticipated. The chemotactic agents used on average resulted in a 30% increase in the activated monocyte population, whereas there was a >50% increase in the population of cells that exhibited a chemotactic response to these agents. Therefore, we conclude that an increase in the population of cells that are responding to an inflammatory insult combined with increased sensitivity to chemotactic agents may have a critical impact on the efficiency of the host defense as first suggested by our group (33). In previous studies, exposure of monocytes to morphine for 5–6 h has been demonstrated to trigger a marked increase in cell activation, yet the mechanisms of NO action on this process were not studied (26, 33). Similar studies using thrombin demonstrate immediate monocyte inhibition and subsequent activation 24 h later (32). Morphine and thrombin have been demonstrated to trigger cNOS-coupled NO release, and indeed the increased monocyte activation observed 5–24 h following morphine or thrombin exposure was reduced or abrogated by NOS inhibition. Direct exposure of cells to NO as assessed in this report, coupled to similar observations using morphine and thrombin, suggests strongly that NO release may directly influence cellular activation.

In contrast to the effects described for SNAP, SAP, a SNAP-like compound that does liberate NO, did not alter cell activation and chemotaxis ,whereas the effects of SNAP on cell activation were blocked in the presence of the NO scavenger carboxy-PTIO. NO generated by SNAP decay is maximal within 10 min and rapidly declines thereafter, suggesting that the effect of NO on cell activation is long-lived. Although destabilization of cytoskelatal actin by NO may explain the ability of NO to inhibit cellular conformation and migration (35, 36), it is unlikely that NO alone mediates the increased activation and responsiveness to IL-1, IL-8, and f-MLP observed subsequent to release from NO inhibition. Thus, NO may also have indirect effects on cell activation. Exposure of vascular endothelial cells to cNOS activators or SNAP before treatment with IFN-{gamma} plus LPS blocked iNOS induction (23). Furthermore, others have demonstrated the involvement of NF-{kappa}B in IL-1- and IL-8-induced cell activation, and NO has recently been demonstrated to inhibit NF-{kappa}B activity via stabilization of the NF-{kappa}B inhibitor, I{kappa}B-{alpha} (37). Thus NO may exert its inhibitory effects directly via interaction with actin and indirectly via activation or stabilization of agents such as I{kappa}B-{alpha}. These data taken together suggest that NO may have direct effects on cellular activation and modulate subsequent responses to chemokines.

Exposure of human neutrophils to NO has been reported to trigger a rapid loss of cellular F-actin and inhibition of fMLP-induced actin polymerization (35). Those authors hypothesize that the transient disruption of actin stress fibers at the subplasmalemmal focal attachment sites could enhance directed migration. Furthermore, exposure of neutrophils to SNAP has been previously demonstrated to reduce F-actin content and adhesion consistent with our results using monocytes in this report. The effect of SNAP in neutrophils was demonstrated to be cGMP independent, consistent with a direct effect of NO on cytoskelatal actin (38). These data are consistent with our observations in human monocytes where increased chemotaxis was directly measured and suggests that the effect of NO on cellular activity may be of general significance and not limited to monocyte populations.

In summary, we provide evidence in human monocytes that NO results in an initial inhibition of monocyte activation and chemotaxis followed an excitatory phase observed subsequent to release from NO inhibition. We suggest that NO may act as a paracrine agent exerting potent immunomodulatory effects on local tissue and, in conjunction with additional agents such as NF-{kappa}B, may exert critical regulation of the host response by modulation of cellular activation, chemotaxis, and responsiveness to chemokines.


   Footnotes
 
1 This work was supported in part by the following grants: MH 17138, DA 09010, the Research Foundation and Central Administration of the State University of New York, and National Institutes of Health Fogarty INT 0045 (to G.B.S.); and AHA 9750211N, DA 10558 (to H.I.M.). Back

2 Address correspondence and reprint request to Dr. Harold I. Magazine, Department of Biology, Queens College, Department of Biology, 65–30 Kissena Boulevard, Flushing, NY 11367. Back

3 Abbreviations used in this paper: NOS, NO sythase; iNOS, inducible NOS; cNOS, constitutive NOS; SNAP, S-nitroso-N-acetyl-DL-penicillamine; SAP, S-acetyl-DL-penicillamine; carboxy-PTIO, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. Back

Received for publication August 4, 1999. Accepted for publication April 14, 2000.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Adamson, D. C., B. Wildemann, M. Sasaki, J. D. Glass, J. C. McArthur, V. I. Christov, T. M. Dawson, V. L. Dawson. 1996. Immunologic NO synthase: elevation in severe AIDS dementia and the induction by HIV-1 gp41. Science 274:1917.[Abstract/Free Full Text]
  2. Bath, P. M. W., D. G. Hasall, A. M. Gladwin, R. M. Palmer, J. F. Martin. 1991. Nitric oxide and prostacyclin: divergence of inhibitory effects on monocyte chemotaxis and adhesion to endothelium in vitro. Arterioscler. Thromb. 11:254.[Abstract/Free Full Text]
  3. Bukrinsky, M., H. Schmidtmayerova, G. Zybarth, L. Dubrovsky, B. Sherry, G. Enikolopov. 1996. A critical role of nitric oxide in human immunodeficiency virus type 1-induced hyperresponsiveness of cultured monocytes. Mol. Med. 2:460.[Medline]
  4. Dawson, V. L., T. M. Dawson. 1996. Nitric oxide neurotoxicity. J. Chem. Neuroanatomy 10:179.[Medline]
  5. DeCaterina, R., P. Libby, H. B. Peng, V. J. Thannickal, T. B. Rajavashisth, Jr M. A. Gimbrone, W. S. Shin, J. K. Liao. 1995. Nitric oxide decreases cytokine-induced endothelial activation: nitric oxide selectively reduces endothelial expression of adhesion molecules and proinflammatory cytokines. J. Clin. Invest. 96:60.
  6. Kreil, T. R., M. M. Eibl. 1996. Nitric oxide and viral infection: NO antiviral activity against a flavivirus in vitro, and evidence for contribution to pathogenesis in experimental infection in vivo. Virol. 219:304.
  7. Kupatt, C., C. Weber, D. A. Wolf, B. F. Becker, T. W. Smith, R. A. Kelly. 1997. Nitric oxide attenuates reoxygenation-induced ICAM-1 expression in coronary microvascular endothelium: role of NF{kappa}B. J. Mol. Cell. Cardiol. 29:2599.[Medline]
  8. Stefano, G. B.. 1999. Substance abuse and HIV-gp120: are opiates protective?. Arch. Immunol. Ther. Exp. 47:99.
  9. Wink, D., I. Hanbauer, M. C. Krishna, W. DeGraff, J. Gamson, J. B. Mitchell. 1993. Nitric oxide protects against cellular damage and cytotoxicity from reactive oxygen species. Proc. Natl. Acad. Sci. USA 90:9813.[Abstract/Free Full Text]
  10. Gyires, K.. 1994. The role of endogenous nitric oxide in the gastroprotective action of morphine. Eur. J. Pharmacol. 255:33.[Medline]
  11. Huang, P. L., Z. Huang, H. Mashimo, K. D. Bloch, M. A. Moskowitz, J. A. Bevan, M. C. Fishman. 1995. Hypertension in mice lacking the gene for endothelial nitric oxide synthase. Nature 377:239.[Medline]
  12. Liew, F. Y.. 1995. Interactions between cytokines and nitric oxide. Adv. Neuroimmunol. 5:201.[Medline]
  13. Ma, X.-L., A. S. Weyrich, D. J. Lefer, A. M. Lefer. 1993. Diminished basal nitric oxide release after myocardial ischemia and reperfusion promotes neutrophil adherence to coronary endothelium. Circ. Res. 72:403.[Abstract/Free Full Text]
  14. Magazine, H. I.. 1995. Detection of endothelial cell-derived nitric oxide: current trends and future directions. Adv. Neuroimmunol. 5:479.[Medline]
  15. Mohanakumar, K. P., I. Hanbauer, C. C. Chiueh. 1998. Neuroprotection by nitric oxide against hydroxyl radical-induced nigral neurotoxicity. J. Chem. Neuroanatomy 14:195.[Medline]
  16. Nishikawa, Y., S. Ogawa. 1997. Importance of nitric oxide in the coronary artery at rest during pacing in humans. J. Am. Coll. Cardiol. 29:85.[Abstract]
  17. Rubanyi, G. M., E. H. Ho, E. H. Cantor, W. C. Lumma, L. H. Parker Botelho. 1991. Cytoprotective function of nitric oxide: inactiviation of superoxide radicals produced by human leukocytes. Biochem. Biophys. Res. Commun. 181:1392.[Medline]
  18. Siegfried, M. R., J. Erhardt, T. Rider. 1992. Cardioprotection and attenuation of endothelial dysfunction by organic nitric oxide donors in myocardial ischemia reperfusion. J. Pharmacol. Exp. Ther. 260:668.[Abstract/Free Full Text]
  19. Siegfried, M. R., C. Carey, X. L. Ma. 1992. Beneficial effects of SPM-5185, a cysteine-containing NO donor in myocardial ischemia reperfusion. Am. J. Physiol. 263:H771.[Abstract/Free Full Text]
  20. Soderberg, L. S. F., J. B. Barnett. 1995. Inhalation exposure to isobutyl nitrite inhibits macrophage tumoricidal activity and modulates inducible nitric oxide. J. Leukocyte Biol. 57:135.[Abstract]
  21. Stefano, G. B., A. Hartman, T. V. Bilfinger, H. I. Magazine, Y. Liu, F. Casares, M. S. Goligorsky. 1995. Presence of the m3 opiate receptor in endothelial cells: coupling to nitric oxide production and vasodilation. J. Biol. Chem. 270:30290.[Abstract/Free Full Text]
  22. Bilfinger, T. V., A. Hartman, Y. Liu, H. I. Magazine, G. B. Stefano. 1997. Cryopreserved veins used for myocardial revascularization: a 5 year experience and a possible mechanism for their increased failure. Ann. Thor. Surg. 63:1063.[Abstract/Free Full Text]
  23. Stefano, G. B., M. Salzet, H. I. Magazine, T. V. Bilfinger. 1998. Antagonist of LPS and IFN-{gamma} induction of iNOS in human saphenous vein endothelium by morphine and anandamide by nitric oxide inhibition of adenylate cyclase. J. Cardiovasc. Pharmacol. 31:813.[Medline]
  24. Bath, P. M., D. G. Hassall, A. M. Gladwin, R. M. Palmer, J. F. Martin. 1991. Nitric oxide and prostacyclin: divergence of inhibitory effects on monocyte chemotaxis and adhesion to endothelium in vitro. Arterioscler. Thromb. 11:254.
  25. Belenky, S. N., R. A. Robbins, I. Rubinstein. 1993. Nitric oxide synthase inhibitors attenuate human monocyte chemotaxis in vitro. J. Leukocyte Biol. 53:498.[Abstract]
  26. Stefano, G. B., M. Salzet, C. Rialas, D. W. Mattocks, C. Fimiani, T. V. Bilfinger. 1998. Macrophage behavior associated with acute and chronic exposure to HIV GP120, morphine and anandamide: endothelial implications. Int. J. Cardiol. 64:S3.
  27. Bøyum, A.. 1983. Isolation of human blood monocytes with Nycodenz, a new non-ionic iodinated gradient medium. Scand. J. Immunol. 17:429.[Medline]
  28. Schon, J. C., J. Torre-Bueno, G. B. Stefano. 1991. Microscopic computer-assisted analysis of conformational state: reference to neuroimmunology. Adv. Neuroimmunol. 1:252.
  29. Stefano, G. B., A. Digenis, S. Spector, M. K. Leung, T. V. Bilfinger, M. H. Makman, B. Scharrer, N. N. Abumrad. 1993. Opiatelike substances in an invertebrate, a novel opiate receptor on invertebrate and human immunocytes, and a role in immunosuppression. Proc. Natl. Acad. Sci. USA 90:11099.[Abstract/Free Full Text]
  30. Stefano, G. B., T. V. Bilfinger. 1993. Human neutrophil and macrophage chemokinesis induced by cardiopulmonary bypass: loss of DAME and IL-1 chemotaxis. J. Neuroimmunol. 47:189.[Medline]
  31. Magazine, H. I., Y. Liu, T. V. Bilfinger, G. L. Fricchione, G. B. Stefano. 1996. Morphine-induced conformational changes in human monocytes, granulocytes, and endothelial cells and in invertebrate immunocytes and microglia are mediated by nitric oxide. J. Immunol. 156:4845.[Abstract]
  32. Srivastava, K. D., H. I. Magazine. 1998. Thrombin receptor activation inhibits monocyte spreading by induction of ET(B) receptor-coupled nitric oxide release. J. Immunol. 161:5039.[Abstract/Free Full Text]
  33. Stefano, G. B., M. K. Leung, T. V. Bilfinger, B. Scharrer. 1995. Effect of prolonged exposure to morphine on responsiveness of human and invertebrate immunocytes to stimulatory molecules. J. Neuroimmunol. 63:175.[Medline]
  34. King, J. M., K. D. Srivastava, G. B. Stefano, T. V. Bilfinger, W. F. Bahou, H. I. Magazine. 1997. Human monocyte adhesion is modulated by endothelin B receptor-coupled nitric oxide release. J. Immunol. 158:880.[Abstract]
  35. 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]
  36. Jun, C. D., M. K. Han, U. H. Kim, H. T. Chung. 1996. Nitric oxide induces ADP-ribosylation of actin in murine macrophages: association with the inhibition of pseudopodia formation, phagocytic activity, and adherence on a laminin substratum. Cell Immunol. 174:25.[Medline]
  37. Peng, H. B., P. Libby, J. K. Liao. 1995. Induction and stabilization of I{kappa}B{alpha} by nitric oxide mediates inhibition of NF-{kappa}B. J. Biol. Chem. 270:14214.[Abstract/Free Full Text]
  38. Sundqvist, T., T. Forslund, T. Bengtsson, K. L. Axelsson. 1994. S-nitroso-N-acetylpenicillamine reduces leukocyte adhesion to type I collagen. Inflammation 18:625.[Medline]



This article has been cited by other articles:


Home page
 J. Immunol.Home page
W. Zhu, P. Cadet, G. Baggerman, K. J. Mantione, and G. B. Stefano
Human White Blood Cells Synthesize Morphine: CYP2D6 Modulation
J. Immunol., December 1, 2005; 175(11): 7357 - 7362.
[Abstract] [Full Text] [PDF]

Home page
 J. Leukoc. Biol.Home page
J. Wang, R. Charboneau, S. Balasubramanian, R. A. Barke, H. H. Loh, and S. Roy
Morphine modulates lymph node-derived T lymphocyte function: role of caspase-3, -8, and nitric oxide
J. Leukoc. Biol., October 1, 2001; 70(4): 527 - 536.
[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 Magazine, H. I.
Right arrow Articles by Stefano, G. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Magazine, H. I.
Right arrow Articles by Stefano, G. B.
Right arrowPubmed/NCBI databases
*Gene*GEO Profiles
*HomoloGene*UniGene
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*(D)-PENICILLAMINE
*NITRIC OXIDE

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS