help button home button
AJRCMB
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Published ahead of print on January 30, 2004, doi:10.1165/rcmb.2003-0373OC
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
2003-0373OCv1
30/6/830    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
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 reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Park, J.-W.
Right arrow Articles by Gelfand, E. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Park, J.-W.
Right arrow Articles by Gelfand, E. W.
American Journal of Respiratory Cell and Molecular Biology. Vol. 30, pp. 830-836, 2004
© 2004 American Thoracic Society
DOI: 10.1165/rcmb.2003-0373OC

Interleukin-1 Receptor Antagonist Attenuates Airway Hyperresponsiveness Following Exposure to Ozone

Jung-Won Park, Christian Taube, Christina Swasey, Taku Kodama, Anthony Joetham, Annette Balhorn, Katsuyuki Takeda, Nobuaki Miyahara, Corrie B. Allen, Azzeddine Dakhama, Soo-Hyun Kim, Charles A. Dinarello and Erwin W. Gelfand

Department of Pediatrics, National Jewish Medical and Research Center, Denver; and Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado

Address correspondence to: Erwin W. Gelfand, M.D., Department of Pediatrics, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206. E-mail: gelfande{at}njc.org


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
The role of an interleukin (IL)-1 receptor antagonist (IL-1Ra) on the development of airway hyperresponsiveness (AHR) and airway inflammation following acute O3 exposure in mice was investigated. Exposure of C57/BL6 mice to O3 at a concentration of 2.0 ppm or filtered air for 3 h resulted in increases in airway responsiveness to inhaled methacholine (MCh) 8 and 16 h after the exposure, and an increase in neutrophils in the bronchoalveolar lavage (BAL) fluid. IL-1ß expression, assessed by gene microarray, was increased 2-fold 4 h after O3 exposure, and returned to baseline levels by 24 h. Levels of IL-1ß in lung homogenates were also increased 8 h after O3 exposure. Administration of (human) IL-1Ra before and after O3 exposure prevented development of AHR and decreased BAL fluid neutrophilia. Increases in chemokine levels in lung homogenates, tumor necrosis factor-{alpha}, MIP-2, and keratinocyte chemoattractant following O3 exposure were prevented by IL-1Ra. Inhalation of dexamethasone, an inhibitor of IL-1 production, blocked the development of AHR, BAL fluid neutrophilia, and decreased levels of IL-1 following O3 exposure. In summary, acute exposure to O3 induces AHR, neutrophilic inflammation, epithelial damage, and IL-1. An IL-1Ra effectively prevents the development of altered airway function, inflammation, and structural damage.

Abbreviations: airway hyperresponsiveness, AHR • bronchoalveolar lavage, BAL • cyclooxygenase 2, COX-2 • enzyme-linked immunosorbent assay, ELISA • interleukin, IL • inducible nitric oxide synthase, iNOS • macrophage inflammatory protein, MIP • tumor necrosis factor-{alpha}, TNF-{alpha}


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Ozone (O3) is a highly toxic oxidant found in urban environments or in the workplace (1). It is a worldwide problem that appears to be increasing. Exposure to O3 causes damage to epithelial cells throughout the lung, targeting central and peripheral airways (2). The response to O3 and to the induced injury includes the liberation of many inflammatory mediators, cytokines, and chemokines, and is highlighted by a rapid and marked, but transient, accumulation of neutrophils (3–9). In many species, including mice, the acute exposure to O3 causes airway hyperresponsiveness (AHR) as well as an acute inflammatory response in the airways (8–11). The role of the neutrophilic inflammatory response in the development of this AHR is not certain. Despite studies showing a linkage (9–12), recent reports indicate a dissociation between neutrophil accumulation and altered airway function (3, 7, 8, 13, 14). This dissociation does not preclude a role for cytokines or chemokines responsible for either or both of these responses.

Among the cytokines/chemokines involved in acute and chronic inflammation, interleukin (IL)-1 is an important, multifunctional proinflammatory cytokine, affecting virtually every cell type (15). The three members of the IL-1 gene family include IL-1{alpha}, IL-1ß, and IL-1 receptor antagonist (IL-1Ra). IL-1{alpha} and IL-1ß are agonists and IL-1Ra is a specific receptor antagonist. IL-1ß is released after proteolytic cleavage and therefore appears to play a predominant role in inflammatory responses (15). Virtually all microbial products stimulate production of the three IL-1 proteins. Nonmicrobial stimulants can also trigger synthesis of these IL-1 proteins. Among these are activated complement components, which through binding to their specific receptors, induce IL-1 transcription and release (16–18). As O3 can induce the activation of complement (14), exposure to O3 may trigger IL-1ß release directly and indirectly. In vitro exposure of human macrophages to O3 also can induce IL-1ß gene transcription and translation (5).

In addition to its proinflammatory activity, IL-1ß has been linked to the development of allergen-induced AHR (19–22) as well as rhinovirus-induced alterations in airway function (23). Thus, it is possible that IL-1ß has a dual role, one in the elicitation of lung inflammation, the other in the development of AHR. In the present study, we examined the role of IL-1 in the development of lung inflammation and AHR following acute O3 exposure.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Animals
Eight- to 12-wk-old female C57BL6/j mice were purchased from Jackson Laboratories (Bar Harbor, ME). All mice were bred and housed under pathogen-free conditions and maintained on an ovalbumin-free diet in the Biological Research Center at National Jewish Medical and Research Center. All protocols and experimental procedures were approved by the Institutional Animal Care and Use Committee of the National Jewish Medical and Research Center.

Experimental Protocol
Mice were exposed to ozone at a concentration of 2.0 ppm for 3 h. The parameters were measured 16 h after O3 exposure. In initial experiments, we showed that AHR reached peak levels between 8 and 16 h after exposure. For inhibition of IL-1, 10 mg/kg of recombinant human IL-1Ra (Amgen, Inc., Thousand Oaks, CA) was administered (three times) to the mice by intraperitoneal injection 30 min before ozone exposure, immediately following, and 8 h after O3 exposure. Another group of mice received two injections of the IL-1Ra, immediately following exposure and 8 h later. To evaluate whether corticosteroids can modify IL-1ß production, airway inflammation, and AHR, four mice were placed in a plexiglass box, and 4 mg of dexamethasone (Sigma, St. Louis, MO) in 10 ml of phosphate-buffered saline was nebulized using an ultrasonic nebulizer (DeVilbiss Health Care) 1 h before and 30 min following O3 exposure.

O3 Exposure
Mice were exposed to O3 at 2.0 ppm for 3 h in stainless steel wire cages. Cages were set inside 240-liter laminar flow inhalation chambers. HEPA-filtered room air was passed through these chambers at 25 changes/h. Room temperature was maintained at 20–25°C. O3 was generated by directing compressed medical-grade oxygen through an electrical discharge O3 generator (Sander Ozonizer, Model 25; Erwin Sander Elektroapparatebau GmbH, Uetze-Eltze, Germany) located upstream of the exposure chamber. The O3–air mixture was metered into the inlet air stream with mass flow controllers (Model #1359C; MKS Instruments Inc., Andover, MA). Exposure to HEPA-filtered air was done in a separate chamber with age- and treatment-matched control animals. O3 concentrations were continuously monitored at mouse nose levels within the chamber with a photometric O3 analyzer (Model 400A; Advanced Pollution Instrumentation, Inc., San Diego, CA) and recorded on a strip-chart recorder. Calibration of the O3 analyzer was performed by the Colorado Department of Public Health and Environment (Denver, CO).

Mouse Genome-Wide mRNA Expression Analysis
Mouse genome-wide mRNA expression analysis (approx. 12,000 genes) was performed using the Affymetrix GeneChip expression analysis system (Affymetrix Inc., Santa Clara, CA). Total RNA was extracted from mouse lungs using Trizol Reagent (Invitrogen Corp., Carlsbad, CA) followed by passage through RNeasy mini columns (QIAGEN Inc., Valencia, CA). Lungs were harvested from O3-exposed animals 4 and 24 h following acute O3 exposure as well as from filtered air–exposed control animals. After careful assessment of the full integrity of RNA by microcapillary electrophoresis and test hybridization, examining 3' to 5' intensity ratios of control genes, the samples were subjected to gene expression analysis according to the Affymetrix technical procedures manual (http://www.affymetrix.com). Briefly, 10 µg of total RNA were reverse-transcribed into cDNA using Superscript II (Stratagene, La Jolla, CA), labeled using the Enzo Bioarray High Yield RNA Transcript Labeling kit (Enzo Diagnostics, New York, NY), and analyzed on MGU 74Av2 chips at the University of Colorado Health Sciences Center Genomics Core Facility (Denver, CO). Expression data were analyzed using GeneSpring software (Silicon Genetics, Redwood City, CA). Hybridization signals were normalized to housekeeping gene signals for each sample and were compared for increases or decreases relative to control animal values.

Determination of AHR
AHR was assessed as a change in airway resistance (cm H2O/ml/s) after challenge with aerosolized methacholine. Briefly, anesthetized (pentobarbital sodium, intraperitoneally administered, 70–90 mg/kg), tracheostomized (18G cannula) mice were mechanically ventilated (160 breaths/min, tidal volume of 150 µl, positive end-expiratory pressure of 2–4 cm H2O), and lung function was assessed using methods described by Takeda and coworkers (24). Lung resistance (RL) was continuously computed (Labview; National Instruments, Dallas, TX) by fitting flow, volume, and pressure to an equation of motion. MCh aerosol was administered by nebulization in increasing concentrations (3–50 mg/ml). Maximum values of RL were calculated and the concentration of MCh that caused a 200% increase in RL (PC200, mg/ml) was calculated.

Bronchoalveolar Lavage
Immediately after assessment of AHR, lungs were lavaged via the tracheal tube with 1 ml of Hanks' balanced salt solution (Gibco, Grand Island, NY). Total cell numbers were obtained (Coulter Counter, Coulter Co. Hialeah, FL). Differential cell counts were performed in a blinded fashion by counting at least 200 cells on cytocentrifuged preparations (Model Cytospin 3; Shandon Ltd, Runcorn, UK) stained with Leukostat (Fisher Diagnostics, Fair Lawn, NJ).

Measurement of Cytokines and Total Protein in Bronchoalveolar Lavage Fluid or Lung Homogenate
Cytokine levels in lung homogenates were determined by enzyme-linked immunosorbent assay (ELISA). Mouse IL-12 (R&D Systems, Minneapolis, MN), KC (R&D Systems), and IL-1ß (R&D Systems) were measured using commercial ELISA kits, per the manufacturer's instructions. Tumor necrosis factor (TNF)-{alpha} and macrophage inflammatory protein (MIP)-2 were measured with kits using anti–TNF-{alpha} (coating antibody AFY10-NA, detection antibody BAF410; R&D Systems), and anti–MIP-2 antibody (coating antibody MAB452, detection antibody BAF452; R&D Systems). Detection limits were as follows: IL-12 (24 pg/ml), IL-1ß (30 pg/ml), TNF-{alpha} (12 pg/ml), MIP-2 (7.5 pg/ml), and keratinocyte chemoattractant (KC) (18 pg/ml). Lung tissue was mixed with a PBS–0.1% Triton-X100 solution containing proteinase inhibitors (PharMingen) at a 1:2.5 ratio of weight per volume. The specimens were homogenized and then centrifuged at 15,000 rpm for 15 min. The supernatants were frozen at –70°C until analysis. Total protein levels in bronchoalveolar lavage (BAL) fluid were measured using the Protein assay kit (Bio-Rad, Hercules, CA).

Statistical Analysis
Data are presented as mean ± SEM. ANOVA was used to determine the levels of difference between all groups. Comparisons for all pairs were performed using the Tukey-Kramer honest significant difference (HSD) test.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Acute O3 Exposure Induces IL-1ß Gene Transcription and Translation
Expression of mRNA in lung tissue was assessed by gene microarray analysis. Following O3 exposure, IL-1 mRNA levels were increased 2-fold at 4 h after exposure (2.0 ppm for 3 h), and returned to baseline levels after 24 h (Figure 1A). IL-1 receptor type II, which is a decoy receptor (15), was also increased by 4-fold at 4 h and returned to baseline levels 24 h following O3 exposure. The level of IL-1{alpha} mRNA was not altered by O3 exposure. We found no changes in expression of other cytokines (IL-2, -3, -4, -5, -9, -10, -12, -13), but an increase in expression of certain chemokines (fold increase at 4 h: KC, 10-fold; MIP-2, 3.5–fold; MCP-1, 7.4-fold; ENA-78, 9.5-fold). IL-1ß is known to induce expression of many different genes (14). However, we did not detect an increase in mRNA expression of several of these genes (CSF, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, phospholipase A-2ß, inducible nitric oxide synthase [iNOS]).



View larger version (15K):
[in this window]
[in a new window]
  		Figure 1. Acute O3 exposure induces IL-1ß gene and IL-1ß protein expression. Gene expression was analyzed by Affymetrix microarray (A) in mice exposed to filtered air (solid bars) or 4 (lightly shaded bars) and 24 h (darkly shaded bars) following ozone exposure. Mean ± SEM are given. IL-1ß levels (B) were measured in lung homogenates by ELISA in mice exposed to filtered air or 8 h and 24 h following ozone exposure. Six animals were studied in each group.

 
IL-1ß protein levels in lung homogenates were evaluated by ELISA (Figure 1B). In parallel to the increases in IL-1ß gene expression, IL-1ß protein levels virtually doubled 8 h after O3 exposure and returned to baseline by 24 h.

Administration of IL-1Ra Prevents the Development of AHR and BAL Fluid Neutrophilia following O3 Exposure
O3 exposure induced an increase in AHR to MCh inhalational challenge (Figure 2). When PC200 values were calculated, O3 exposure resulted in a significant (P < 0.01) decrease (mean ± SEM: 20.2 ± 3.4 mg/ml) compared with air-exposed animals (78.2 ± 18.2). Administration of IL-1Ra intraperitoneally at three time points (before, immediately following, and 8 h after completion of the O3 exposure) prevented the development of AHR in response to increasing concentrations of inhaled MCh, 16 h after exposure (Figure 2). PC200 values also increased in the IL-Ra–treated mice (PC200: 64.5 ± 11.5, P = 0.034 compared with O3-exposed mice). BAL fluid neutrophilia is one of the characteristic consequences of acute O3 exposure. Treatment with IL-1Ra markedly decreased BAL fluid neutrophilia at this time point, as well as decreasing the total cell count in BAL fluid (Figure 3). Neutrophil numbers were decreased by more than 80%. O3 exposure increased BAL fluid total protein levels in exposed mice. However, administration of IL-1Ra did not affect BAL fluid total protein content (Figure 4) at 8, 16, or 48 h after O3 exposure.



View larger version (18K):
[in this window]
[in a new window]
  		Figure 2. IL-1Ra prevents the development of AHR following O3 exposure. Altered airway function was determined as an increase in airway resistance following inhalation of methacholine. AHR was assessed 16 h following O3 exposure (n = 8 in each group). #P < 0.05, *P < 0.01. Filled circles, filtered air; open circles, O3; triangles, O3/IL-1Ra.

 


View larger version (21K):
[in this window]
[in a new window]
  		Figure 3. Effect of IL-1Ra on O3-induced BAL neutrophilia. BAL fluid was obtained 16 h after ozone exposure. The mice were the same as depicted in Figure 2 (n = 8 in each group). *P < 0.01, #P < 0.05. Solid bars, filtered air; lightly shaded bars, O3; darkly shaded bars, O3/IL-1Ra.

 


View larger version (24K):
[in this window]
[in a new window]
  		Figure 4. Failure of IL-1Ra to alter O3-induced increases in BAL fluid protein levels. IL-1Ra does not affect the BAL total protein levels. The mice were the same as shown in Figure 2. *P < 0.01. Solid bars, filtered air; lightly shaded bars, O3/placebo; darkly shaded bars, O3/IL-1Ra.

 
Several cytokines/chemokines have been implicated in the accumulation of neutrophils in target tissues. O3 exposure induced increases in the levels of TNF-{alpha}, MIP-2, and KC, each known to have neutrophil chemoattractant capability in lung tissue homogenates (25). Administration of the IL-1Ra restored the levels of TNF-{alpha}, MIP-2, and KC in lung homogenates in O3-exposed mice to those observed in air-exposed mice (Figure 5).



View larger version (19K):
[in this window]
[in a new window]
  		Figure 5. Effect of IL-1Ra on O3-induced cytokine levels in lung homogenates. Levels of TNF-{alpha}, keratinocyte chemoattractant (KC), and MIP-2 were quantitated in lung honogenates. IL-1Ra decreases production of these cytokines (n = 8 in each group). #P < 0.05. Solid bars, filtered air; lightly shaded bars, O3/placebo; darkly shaded bars, O3/IL-1Ra.

 
Prevention of O3-Induced Structural Damage by IL-1Ra
A striking feature of acute O3 exposure is the alteration in structural integrity of the epithelial cell layer along the airways. As shown in Figures 6A and 6B, when the histology of the airways in air-exposed mice is compared with that in O3-exposed animals, the latter shows sloughing, denudation, and structural abnormalities of the epithelial cells. Treatment with the IL-1Ra prevented these changes in O3-exposed mice, preserving the integrity of the epithelial cells (Figure 6C).



View larger version (86K):
[in this window]
[in a new window]
  		Figure 6. IL-1Ra prevents the damage to tracheal mucosa induced by acute O3 exposure. (A) Filtered air exposed, (B) O3 exposed, (C) O3 exposure and IL-1Ra administration. The tissues were obtained 16 h after O3 exposure.

 
Delay in Administration of IL-1Ra Remains Effective
We also evaluated whether initiating IL-1Ra treatment after completion of the exposure to O3 still remains effective in preventing AHR and neutrophilic inflammation. In these experiments, IL-1Ra was injected twice, immediately following the 3-h O3 exposure and 8 h after the exposure. Although IL-1Ra treatment was initiated immediately after O3 exposure was completed, it nonetheless remained effective, significantly reducing the level of AHR; this reduction was also reflected in an increase in PC200 (mean ± SEM: 38.4 ± 2.9 mg/ml in IL-1Ra–treated mice compared with 19.1 ± 1.7 in untreated O3-exposed mice, P < 0.05) and BAL fluid neutrophilia 16 h after completion of the exposure protocol (Figure 7). The degree of inhibition of AHR at 16 h was somewhat lower than when administered before O3 exposure, but nonetheless significantly reduced AHR and reduced the extent of neutrophilia to the same degree as observed when IL-1Ra treatment was initiated before O3 exposure.



View larger version (15K):
[in this window]
[in a new window]
  		Figure 7. Administration of IL-1Ra after O3 exposure remains effective. IL-1Ra was administered immediately and 8 h following O3 exposure, and prevented the development of AHR (A) and BAL fluid neutrophilia (B) (n = 8 in each group). *P < 0.01, #P < 0.05. (A) Filled circles, filtered air; open circles, O3; triangles, O3/IL-1Ra. (B) Solid bars, filtered air; lightly shaded bars, O3; darkly shaded bars, O3/IL-1Ra.

 
Administration of Dexamethasone Suppresses the Development of AHR, Neutrophilia, and Production of IL-1ß following O3 Exposure
Corticosteroids can decrease both the activity and production of IL-1 and increase the levels of decoy receptor (type II IL-1 receptor) in various disease models (26–28). The effects of inhaled dexamethasone on the responses to O3 were evaluated 16 h after the exposure. Following inhalation of dexamethasone before and just after O3 exposure, AHR was suppressed (Figure 8A), PC200 was increased (mean ± SEM: 68.9 ± 7.2 mg/ml in dexamethasone-treated mice compared with 29.1 ± 2.3 in untreated O3-exposed mice, P < 0.05), and BAL fluid neutrophilia was also significantly reduced (Figure 8B). Although the suppression of AHR was similar when dexamethasone (Figure 8A) was compared with IL-1Ra (Figure 2), there were significant differences (P < 0.05) in the degree of suppression of airway neutrophilia. In addition, IL-1ß levels in the lung homogenates were markedly decreased by dexamethasone inhalation (Figure 8C). Similar to treatment with IL-1Ra, treatment with dexamethasone prevented epithelial shedding, but had no effect on protein content in the BAL fluid following O3 exposure (data not shown).




View larger version (30K):
[in this window]
[in a new window]
  		Figure 8. Inhalation of dexamethasone suppresses development of AHR (A), BAL fluid neutrophilia (B), and IL-1ß production (C) following O3 exposure. Dexamethasone was administered 1 h before and 30 min after O3 exposure (n = 8 in each group). *P < 0.01, #P < 0.05. (A) Filled circles, filtered air; open circles, O3; triangles, O3/Dexa. (B) Solid bars, filtered air; lightly shaded bars, O3; darkly shaded bars, O3/Dexa.

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
Acute O3 exposure can induce the rapid development of AHR, neutrophilic inflammation, vascular leakage, and respiratory epithelial cell damage. However, the mechanisms underlying these changes are not defined, nor whether a common pathway in each of these events is activated. The susceptibility to O3 is strain-dependent (29, 30) and has been linked to TNF-{alpha} receptor expression (10, 11). TNF-{alpha} can induce IL-13 (31) and IL-1ß can upregulate TNF-{alpha} production (32), supporting their involvement in O3-induced AHR. In this study, we demonstrated that one consequence of O3 exposure is the > 2-fold induction of the IL-1ß gene within 4 h of the exposure with a return to baseline levels by 24 h. This increase in gene transcription paralleled increases in IL-1ß protein levels in lung homogenates. The production and activity of IL-1, particularly IL-1ß, are tightly regulated events (14). Following stimulation of monocytes/macrophages with endotoxin, transcription of IL-1ß is initiated, achieves a steady-state level, and by 4 h mRNA levels decrease due to synthesis of a transcriptional repressor (33, 34). A second regulatory level involves expression of IL-1RII, which acts as a decoy receptor for IL-1ß, tightly binding IL-1ß and preventing binding to the signal transducing type I receptor (35). IL-1ß can upregulate gene expression of IL-1RII (36), and an upregulation of IL-1RII gene was observed following O3 exposure.

The major sources of IL-1ß are cells of monocytic lineage, where cleavage of pro–IL-1ß takes place by caspase-1 and mature IL-1ß is secreted from stimulated cells (15). Alveolar macrophages represent a first line of cells that may interact with O3 and also have the capacity to secrete various cytokines, including IL-1ß. In vitro, low concentrations of O3 induced significant increases in IL-1ß secretion from both guinea pig and cultured human alveolar macrophages (5).

The three major consequences of O3 exposure are airway neutrophilia, airway epithelial cell damage, and AHR to inhalation of the bronchoconstrictor MCh. Each of these responses was significantly inhibited when mice were treated with the IL-1Ra just before, immediately after, and 8 h after O3 exposure. Despite near-equal affinities of IL-1ß and IL-1Ra for the functional IL-1RI, a 10- to 100-fold molar excess of IL-1Ra is often required to inhibit IL-1 activity in vitro (37) and a 100- to 1,000-fold excess to block systemic responses in animals (38, 39). In these studies, 10 mg/kg IL-1Ra was injected on three occasions and resulted in the normalization of airway responsiveness to inhaled MCh. BAL neutrophil counts were reduced by 75–80%; associated with this decrease in accumulation of neutrophils was a reduction in levels of TNF-{alpha}, MIP-2, and KC. All three of these proteins have been linked to neutrophil accumulation in target organs (25). Impressively, administration of IL-1Ra also prevented the marked epithelial cell damage seen following O3 exposure in untreated mice. The only response to O3 that was not apparently affected was the increase in BAL fluid protein levels. As a rule, capillary leak models may be unaffected by blocking cytokines (15).

The potency of the IL-1Ra in preventing these changes was not only seen when administered on two occasions, but also when administered after completion of the ozone exposure. Used in this way, the IL-1Ra also resulted in a decrease in BAL neutrophilia and AHR measured 16 h after exposure. As AHR and BAL neutrophilia persist at this time point in untreated mice, the efficacy of IL-1Ra after completion of exposure implies the ability to reverse some of the ongoing changes.

Cumulatively, the data indicate that IL-1 is important to the development of AHR, neutrophilia, and epithelial cell damage. Although we and others have dissociated O3-induced AHR and neutrophilia (3, 7, 8, 13, 14), it appears that IL-1 can play a role in the development of both of these "independent" responses. Epithelial cell damage also appeared independent of the neutrophilia. The mechanisms whereby IL-1 triggers these different responses is not clear. IL-1 is known to elicit multiple biologic effects. IL-1 can increase the genes for colony-stimulating factors (15), contributing to bone marrow release of neutrophils. Increased expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 induced by IL-1ß on endothelial cells also can contribute to neutrophil accumulation in the airways (15). Injection of IL-1 into rodent tracheas resulted in acute alveolar leakage as well as neutrophil inflammation (40, 41). IL-1ß has been implicated in the development of allergen-induced AHR (19–22) or in rhinovirus-induced AHR (23). In these studies, as shown here, the role of IL-1ß was implied, based on the protective effects of an IL-1Ra on development of AHR and pulmonary eosinophil accumulation. In others, IL-1ß was shown to directly alter airway smooth muscle responsiveness, and this effect was not surprisingly reversed by IL-1Ra (41).

Support for an IL-1 autocrine loop has been demonstrated in altered responsiveness of airway smooth muscle preparations to sensitizing sera from individuals with atopic asthma or rhinovirus (19, 20, 23). In human cultured airway smooth muscle cells, IL-1ß increases cyclooxygenase (COX)-2 expression and subsequent prostaglandin E2 release, ultimately resulting in decreased ß-adrenergic responsiveness. Low concentrations of IL-1ß together with TNF-{alpha} synergize to promote this ß-adrenergic hyporesponsiveness, and this is, in turn, dependent on COX-2 expression and prostaglandin E2 (42). As both TNF-{alpha} and IL-1ß protein levels were shown to increase in lung homogenates following O3 exposure, this combination may also contribute to the development of the AHR shown here and be prevented by administration of IL-1Ra.

Three genes that code for specialized enzymes are exquisitely sensitive to IL-1: iNOS, COX2, and type 2 phospholipase A2 (15). These genes were not induced following O3 exposure at the time points analyzed. Their products nitric oxide, prostaglandins, leukotrienes, thromboxane, and platelet-activating factor (PAF) are potent mediators of inflammation and tissue damage, particularly in the lung. Collectively and individually, they can contribute to the structural and permeability changes in the epithelium induced by O3. Kleeberger and colleagues have demonstrated an important role for iNOS in O3-induced lung permeability, perhaps involving Toll-like receptor 4 (43). PAF has been shown to partially mediate O3-induced pulmonary inflammation and epithelial cell proliferation (44).

Corticosteroids suppress IL-1ß gene expression and secretion and increase the production of the decoy receptor IL-1RII (15). Glucocorticoids can abolish IL-1ß and ß-adrenergic hyporesponsiveness in human airway smooth muscle cells, and can abrogate IL-1ß–induced changes in airway smooth muscle contractility (45, 46). In our studies, inhalation of dexamethasone had significant effects on the changes induced by O3. AHR was significantly reduced as were IL-1ß levels in lung homogenates. Numbers of neutrophils in the BAL fluid were reduced by ~ 40%, certainly less than following treatment with the IL-1Ra, perhaps further supporting the dissociation between O3-induced AHR and lung neutrophilia.

In summary, acute O3 exposure results in epithelial cell damage, a neutrophil-predominant airway inflammatory response, and AHR. Ozone induces an increase in IL-1ß gene expression and protein levels in the lung tissue. Administration of IL-1Ra, blocking access of IL-1ß to its receptor, results in normalization of airway function, prevention of airway/epithelial cell structural damage, and inhibition of neutrophil accumulation in the airways. These findings are supported by treatment with a glucocorticoid that prevents the increases in IL-1ß production following O3 exposure. Together these data identify a major role for IL-1ß in the pathogenesis of the airway response to acute O3 exposure.


   Acknowledgments
 
This study was supported by EPA Grant (R825702), and NIH grants HL-36577 and HL-61005 (to E.W.G.), and grants AI-15614, HL-68743 (to C.A.D.). J.W.P. was supported by the Korean Research Foundation Grant (KRF-2001-013-F00031) and the Helen Wohlberg and Herman Lambert Fellowship program in Cancer Biology at National Jewish Medical and Research Center. C.T. was supported by Deutsche Forschungsgemeinschaft (Ta 275/2-1).

Received in original form October 17, 2003

Received in final form December 29, 2003


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. National Institute of Environmental Health Sciences. Ozone alerts. Research Triangle Park, NC. NIH Publication #99–4671.
  2. Sterner-Kock, A., M. Kock, R. Braun, and D. M. Hyde. 2000. Ozone-induced epithelial injury in the ferret is similar to nonhuman primates. Am. J. Respir. Crit. Care Med. 162:1152–1156.[Abstract/Free Full Text]
  3. Koto, H., M. Salmon, B. Haddad el, T. J. Huang, J. Zagorski, and K. F. Chung. 1997. Role of cytokine-induced neutrophil chemoattractant (CINC) in ozone-induced airway inflammation and hyperresponsiveness. Am. J. Respir. Crit. Care Med. 156:234–239.[Abstract/Free Full Text]
  4. Zhao, Q., L. G. Simpson, K. E. Driscoll, and G. D. Leikauf. 1998. Chemokine regulation of ozone-induced neutrophil and monocyte inflammation. Am. J. Physiol. 274:L39–L46.
  5. Arsalane, K., P. Gosset, D. Vanhee, C. Voisin, Q. Hamid, A. B. Tonnel, and B. Wallaert. 1995. Ozone stimulates synthesis of inflammatory cytokines by alveolar macrophages in vitro. Am. J. Respir. Cell Mol. Biol. 13:60–68.[Abstract]
  6. Pendino, K. J., R. L. Shuler, J. D. Laskin, and D. L. Laskin. 1994. Enhanced production of interleukin-1, tumor necrosis factor-{alpha}, and fibronectin by rat lung phagocytes following inhalation of a pulmonary irritant. Am. J. Respir. Cell Mol. Biol. 11:279–286.[Abstract]
  7. Zhang, L. Y., R. C. Levitt, and S. R. Kleeberger. 1995. Differential susceptibility to ozone-induced airways hyperreactivity in inbred strains of mice. Exp. Lung Res. 21:503–518.[Medline]
  8. Li, Z., E. E. Daniel, C. G. Lane, M. A. Arnaout, and P. M. O'Byrne. 1992. Effect of an anti-Mo1 MAb on ozone-induced airway inflammation and airway hyperresponsiveness in dogs. Am. J. Physiol. 263:L723–L726.
  9. Holtzman, M. J., L. M. Fabbri, P. M. O'Byrne, B. D. Gold, H. Aizawa, E. H. Walters, S. E. Alpert, and J. A. Nadel. 1983. Importance of airway inflammation for hyperresponsiveness induced by ozone. Am. Rev. Respir. Dis. 127:686–690.[Medline]
  10. Cho, H.-Y., K.-Y. Zhang, and S. R. Kleeberger. 2001. Ozone-induced lung inflammation and hyperreactivity are mediated via tumor necrosis factor-{alpha} receptors. Am. J. Physiol. Lung Cell. Mol. Physiol. 280:L537–L546.[Abstract/Free Full Text]
  11. Shore, S. A., I. N. Schwartzman, B. Le Blance, G. G. Krishna Murthy, and C. M. Doerschuk. 2001. Tumor necrosis factor receptor 2 contributes to ozone-induced airway hyperresponsiveness in mice. Am. J. Respir. Crit. Care Med. 164:602–607.[Abstract/Free Full Text]
  12. O'Byrne, P. M., E. H. Walters, B. D. Gold, H. A. Aizawa, L. M. Fabbri, S. E. Alpert, J. A. Nadel, and M. J. Holtzman. 1984. Neutrophil depletion inhibits airway hyperresponsiveness induced by ozone exposure. Am. Rev. Respir. Dis 130:214–219.[Medline]
  13. Evans, T. W., J. J. Brokaw, K. F. Chung, J. A. Nadel, and D. M. McDonald. 1988. Ozone-induced bronchial hyperresponsiveness in the rat is not accompanied by neutrophil influx or increased vascular permeability in the trachea. Am. Rev. Respir. Dis 138:140–144.[Medline]
  14. Park, J. W., C. Taube, A. Joetham, K. Takeda, T. Kodama, A. Dakhama, G. McConville, C. B. Allen, G. Sfyroera, L. D. Shultz, J. D. Lambris, P. C. Giclas, V. M. Holers, and E. W. Gelfand. 2004. Complement activation is critical to airway hyperresponsiveness following acute ozone exposure. Am. J. Respir. Crit. Care Med. 169:726–732.[Abstract/Free Full Text]
  15. Dinarello, C. A. 1996. Biologic basis for interleukin-1 in disease. Blood 87:2095–2147.[Abstract/Free Full Text]
  16. Schindler, R., J. A. Gelfand, and C. A. Dinarello. 1990. Recombinant C5a stimulates transcription rather than translation of IL-1 and TNF: cytokine synthesis induced by LPS, IL-1 or PMA. Blood 76:1631–1638.[Abstract/Free Full Text]
  17. Bacle, F., N. Haeffner-Cavaillon, M. Laude, C. Couturier, and M. D. Kazatchkine. 1990. Induction of IL-1 release through stimulation of the C3b/C4b complement receptor type one (CR1, CD35) on human monocytes. J. Immunol. 144:147–152.[Abstract]
  18. Couturier, C., N. Haeffner-Cavaillon, L. Weiss, E. Fisher, and M. D. Kazatchkine. 1990. Induction of cell-associated interleukin 1 through stimulation of the adhesion-promoting proteins LFA-1 (CD 11a/CD18) and CR3 (CD11b/CD18) of human monocytes. Eur. J. Immunol. 20:999–1005.[Medline]
  19. Hakonarson, H., D. J. Herrick, G. Serrano, and M. M. Grunstein. 1997. Autocrine role of interleukin 1ß in altered responsiveness of atopic asthmatic sensitized airway smooth muscle. J. Clin. Invest. 99:117–124.[Medline]
  20. Hakonarson, H., N. Maskeri, C. Carter, S. Chuang, and M. M. Grunstein. 1999. Autocrine interaction between IL-5 and IL-1ß mediates altered responsiveness of atopic asthmatic sensitized airway smooth muscle. J. Clin. Invest. 104:657–667.[Medline]
  21. Okada, S., H. Inoue, K. Yamauchi, H. Lijima, Y. Ohkawara, T. Takishima, and K. Shirato. 1995. Potential role of interleukin-1 in allergen-induced late asthmatic reactions in guinea pigs: suppressive effect of interleukin-1 receptor antagonist on late asthmatic reaction. J. Allergy Clin. Immunol. 95:1236–1245.[CrossRef][Medline]
  22. Nakae, S., Y. Komiyama, H. Yokoyama, A. Nambu, M. Umeda, M. Iwase, I. Homma, K. Sudo, R. Horai, M. Asano, and Y. Iwakura. 2003. IL-1 is required for allergen-specific Th2 cell activation and the development of airway hypersensitivity response. Int. Immunol. 15:483–490.[Abstract/Free Full Text]
  23. Hakonarson, H., C. Carter, N. Maskeri, R. Hodinka, and M. M. Grunstein. 1999. Rhinovirus-mediated changes in airway smooth muscle responsiveness: induced autocrine role of interleukin-1ß. Am. J. Physiol. Lung Cell. Mol. Physiol. 277:L13–L21.[Abstract/Free Full Text]
  24. Takeda, K., E. Hamelmann, A. Joetham, L. Shultz, G. L. Larsen, C. G. Irvin, and E. W. Gelfand. 1997. Development of eosinophilic airway inflammation and airway hyperresponsiveness in mast cell-deficient mice. J. Exp. Med. 186:449–454.[Abstract/Free Full Text]
  25. Nick, J. A., S. K. Young, K. K. Brown, N. J. Avdi, P. G. Arndt, B. T. Suratt, M. S. Janes, P. M. Henson, and G. S. Worthen. 2000. Role of p38 mitogen-activated protein kinase in a murine model of pulmonary inflmmation. J. Immunol. 164:2151–2159.[Abstract/Free Full Text]
  26. Auphan, N., J. A. DiDonato, C. Rosette, A. Helmberg, and M. Karin. 1995. Immunosuppression by glucocorticoids: inhibition of NF{kappa}B activity through induction of I{kappa}B synthesis. Science 270:286–290.[Abstract/Free Full Text]
  27. Scheinman, R. I., P. C. Cogswell, A. K. Lofquist, and A. S. Baldwin. 1995. Role of transcriptional activation of I{kappa}B{alpha} in mediation of immunosuppression by glucocorticoids. Science 270:283–286.[Abstract/Free Full Text]
  28. Re, F., M. Muzio, M. De Rossi, N. Polentarutti, J. G. Giri, A. Mantovani, and F. Colotta. 1994. The type II "receptor" as a decoy target for interleukin 1 in polymorphonuclease leukocytes: characterization of induction by dexa-methasone and ligand binding properties of the released decoy receptors. J. Exp. Med. 179:739–743.[Abstract/Free Full Text]
  29. Kleeberger, S. R., R. C. Levitt, and L.-Y. Zhang. 1993. Susceptibility to ozone-induced inflammation. II. Separate loci control responses to acute and subacute exposures. Am. J. Physiol. Lung Cell. Mol. Physiol. 264:L21–L26.[Abstract/Free Full Text]
  30. Kleeberger, S. R., R. C. Levitt, L.-Y. Zhang, M. Longphre, J. Harkema, A. Jedlicka, S. Eleff, D. DiSilvestre, and K. J. Holroyd. 1997. Linkage analysis of susceptibility to ozone-induced lung inflammation in inbred mice. Nat. Genet. 17:475–478.[CrossRef][Medline]
  31. Dinarello, C. A., J. G. Cannon, S. M. Wolff, H. A. Bernheim, B. Beutler, A. Cerami, I. S. Figari, M. A. Palladino, Jr., and J. V. O'Connor. 1986. Tumor necrosis factor (cachectin) is an endogenous pyogen and induces production of interleukin 1. J. Exp. Med. 163:1433–1450.[Abstract/Free Full Text]
  32. Ikejima, T., S. Ikusawa, P. Ghezzi, J. W. M. van der Meer, and C. A. Dinarello. 1990. IL-1 induces TNF in human PBMC in vitro and a circulating TNF-like activity in rabbits. J. Infect. Dis. 162:215–221.[Medline]
  33. Fenton, M. J., B. D. Clark, K. L. Collins, A. C. Webb, A. Rich, and P. E. Auron. 1987. Transcriptional regulation of the human prointerleukin 1 beta gene. J. Immunol. 138:3972–3979.[Abstract]
  34. Fenton, M. J., M. W. Vermeulen, B. D. Clark, A. C. Webb, and P. E. Aeuron. 1988. Human pro-IL-1 beta gene expression in monocytic cells is regulated by two distinct pathways. J. Immunol. 140:2267–2273.[Abstract]
  35. Colotta, F., F. Re, M. Muzio, R. Bertini, N. Polentarutti, M. Sironi, J. Giri, S. K. Dower, J. E. Sims, and A. Mantovani. 1993. Interleukin-1 type II receptor: a decoy target for IL-1 that is regulated by IL-4. Science 261:472–475.[Abstract/Free Full Text]
  36. Bristulf, J., S. Gatti, D. Malinowsky, L. Bjork, A. K. Sundgren, and T. Bartfai. 1994. Interleukin-1 stimulates the expression of type I and type II interleukin-1 receptors in the rat insulinoma cell line Rinm5F: sequencing a rat type II interleukin-1 receptor cDNA. Eur. Cytokine Netw. 5:319–330.[Medline]
  37. Arend, W. P., H. G. Welgus, R. C. Thompson, and S. P. Eisenberg. 1990. Biological properties of recombinant human monocyte-derived interleukin-1 receptor antagonist. J. Clin. Invest. 85:1694–1697.
  38. Ohlsson, K., P. Bjork, M. Bergenfeldt, R. Hageman, and R. C. Thompson. 1990. Interleukin-1 receptor antagonist reduces mortality from endotoxin shock. Nature 348:550–552.[CrossRef][Medline]
  39. Fischer, E., M. A. Marano, A. E. Barber, A. A. Hudson, K. Lee, W. R. Benjamin, S. F. Lowry, and L. L. Moldawer. 1991. A comparison between the effects of interleukin-1{alpha} administration and sublethal endotoxemia in primates. Am. J. Physiol. 261:R442–R452.
  40. Hybertson, B. M., Y. M. Lee, and J. E. Repine. 1997. Phagocytes and acute lung injury: dual roles for interleukin-1. Ann. N. Y. Acad. Sci. 832:266–273.[Abstract/Free Full Text]
  41. Lee, Y. M., B. M. Hybertson, H. G. Cho, L. S. Terada, O. Cho, A. J. Repine, and J. E. Repine. 2000. Platelet-activating factor contributes to acute lung leak in rats given interleukin-1 intratracheally. Am. J. Physiol. Lung Cell. Mol. Physiol. 279:L75–L80.[Abstract/Free Full Text]
  42. Moore, P. E., T. Lahiri, J. D. Laporte, T. Church, R. A. Panettieri, Jr., and S. A. Shore. 2001. Synergism between TNF-{alpha} and IL-1ß in airway smooth muscle cells: implications for ß-adrenergic responsiveness. J. Appl. Physiol. 91:1467–1474.[Abstract/Free Full Text]
  43. Kleeberger, S. R., S. P. M. Reddy, L.-Y. Zhang, H.-Y. Cho, and A. E. Jedlick. 2001. Toll-like receptor 4 mediates ozone-induced murine lung hypermeability via inducible nitric oxide synthase. Am. J. Physiol. Lung Cell. Mol. Physiol. 280:L326–L333.[Abstract/Free Full Text]
  44. Longphre, M., L.-Y. Zhang, J. R. Harkema, and S. R. Kleeberger. 1999. Ozone-induced pulmonary inflammation and epithelial proliferation are partially mediated by PAF. J. Appl. Physiol. 86:341–349.[Abstract/Free Full Text]
  45. Hakornason, H., E. Halapi, R. Whelan, J. Gulcher, K. Stefansson, and M. M. Grunstein. 2001. Association between IL-1ß/TNF-{alpha} induced glucocorticoid-sensitive changes in multiple gene expression and altered responsiveness in airway smooth muscle. Am. J. Respir. Cell Mol. Biol. 25:761–771.[Abstract/Free Full Text]
  46. Moore, P. E., J. D. Laporte, S. Gonzalez, W. Moller, J. Heyder, R. A. Panettieri, Jr., and S. A. Shore. 1999. Glucocorticoids ablate IL-1ß-induced ß-adrenergic hyporesponsiveness in human airway smooth muscle cells. Am. J. Physiol. 277:L932–L942.



This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
R. A. Johnston, T. A. Theman, F. L. Lu, R. D. Terry, E. S. Williams, and S. A. Shore
Diet-induced obesity causes innate airway hyperresponsiveness to methacholine and enhances ozone-induced pulmonary inflammation
J Appl Physiol, June 1, 2008; 104(6): 1727 - 1735.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
J. E. Lang, E. S. Williams, J. P. Mizgerd, and S. A. Shore
Effect of obesity on pulmonary inflammation induced by acute ozone exposure: role of interleukin-6
Am J Physiol Lung Cell Mol Physiol, May 1, 2008; 294(5): L1013 - L1020.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
R. Manzer, C. A. Dinarello, G. McConville, and R. J. Mason
Ozone Exposure of Macrophages Induces an Alveolar Epithelial Chemokine Response through IL-1{alpha}
Am. J. Respir. Cell Mol. Biol., March 1, 2008; 38(3): 318 - 323.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Med.Home page
M. Pichavant, S. Goya, E. H. Meyer, R. A. Johnston, H. Y. Kim, P. Matangkasombut, M. Zhu, Y. Iwakura, P. B. Savage, R. H. DeKruyff, et al.
Ozone exposure in a mouse model induces airway hyperreactivity that requires the presence of natural killer T cells and IL-17
J. Exp. Med., February 18, 2008; 205(2): 385 - 393.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
R. A. Johnston, J. P. Mizgerd, L. Flynt, L. J. Quinton, E. S. Williams, and S. A. Shore
Type I Interleukin-1 Receptor Is Required for Pulmonary Responses to Subacute Ozone Exposure in Mice
Am. J. Respir. Cell Mol. Biol., October 1, 2007; 37(4): 477 - 484.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
J. W. Hollingsworth, S. Maruoka, Z. Li, E. N. Potts, D. M. Brass, S. Garantziotis, A. Fong, W. M. Foster, and D. A. Schwartz
Ambient Ozone Primes Pulmonary Innate Immunity in Mice
J. Immunol., October 1, 2007; 179(7): 4367 - 4375.
[Abstract] [Full Text] [PDF]

Home page
 Proc Am Thorac SocHome page
J. W. Hollingsworth, S. R. Kleeberger, and W. M. Foster
Ozone and Pulmonary Innate Immunity
Proceedings of the ATS, July 1, 2007; 4(3): 240 - 246.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
H.-Y. Cho, D. L. Morgan, A. K. Bauer, and S. R. Kleeberger
Signal Transduction Pathways of Tumor Necrosis Factor-mediated Lung Injury Induced by Ozone in Mice
Am. J. Respir. Crit. Care Med., April 15, 2007; 175(8): 829 - 839.
[Abstract] [Full Text] [PDF]

Home page
 Eur Respir JHome page
R. A. Ramadas, A. Sadeghnejad, W. Karmaus, S. H. Arshad, S. Matthews, M. Huebner, D-Y. Kim, and S. L. Ewart
Interleukin-1R antagonist gene and pre-natal smoke exposure are associated with childhood asthma
Eur. Respir. J., March 1, 2007; 29(3): 502 - 508.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
I. Sabroe, L. C. Parker, D. H. Dockrell, D. E. Davies, S. K. Dower, and M. K. B. Whyte
Targeting the Networks that Underpin Contiguous Immunity in Asthma and Chronic Obstructive Pulmonary Disease
Am. J. Respir. Crit. Care Med., February 15, 2007; 175(4): 306 - 311.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
F. L. Lu, R. A. Johnston, L. Flynt, T. A. Theman, R. D. Terry, I. N. Schwartzman, A. Lee, and S. A. Shore
Increased pulmonary responses to acute ozone exposure in obese db/db mice
Am J Physiol Lung Cell Mol Physiol, May 1, 2006; 290(5): L856 - L865.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
G. E. Morris, M. K. B. Whyte, G. F. Martin, P. J. Jose, S. K. Dower, and I. Sabroe
Agonists of Toll-like Receptors 2 and 4 Activate Airway Smooth Muscle via Mononuclear Leukocytes
Am. J. Respir. Crit. Care Med., April 15, 2005; 171(8): 814 - 822.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
M. K. Pulfer, C. Taube, E. Gelfand, and R. C. Murphy
Ozone Exposure in Vivo and Formation of Biologically Active Oxysterols in the Lung
J. Pharmacol. Exp. Ther., January 1, 2005; 312(1): 256 - 264.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
R. A. Johnston, J. P. Mizgerd, and S. A. Shore
CXCR2 is essential for maximal neutrophil recruitment and methacholine responsiveness after ozone exposure
Am J Physiol Lung Cell Mol Physiol, January 1, 2005; 288(1): L61 - L67.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
2003-0373OCv1
30/6/830    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
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 reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Park, J.-W.
Right arrow Articles by Gelfand, E. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Park, J.-W.
Right arrow Articles by Gelfand, E. W.

HOME HELP FEEDBACK