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Published ahead of print on April 3, 2003, doi:10.1165/rcmb.2003-0035OC
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American Journal of Respiratory Cell and Molecular Biology. Vol. 29, pp. 314-320, 2003
© 2003 American Thoracic Society
DOI: 10.1165/rcmb.2003-0035OC

Role of Prostaglandin I2 in Airway Remodeling Induced by Repeated Allergen Challenge in Mice

Koichi Nagao, Hiroyuki Tanaka, Masato Komai, Taisei Masuda, Shuh Narumiya and Hiroichi Nagai

Department of Pharmacology, Gifu Pharmaceutical University, Gifu; and Department of Pharmacology, Faculty of Medicine, Kyoto University, Kyoto, Japan

Address correspondence to: Hiroichi Nagai, Prof., Ph.D., Department of Pharmacology, Gifu Pharmaceutical University, 5–6-1 Mitahora-higashi, Gifu 502–8585, Japan. E-mail: nagai{at}gifu-pu.ac.ip


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Recently, we demonstrated that prostaglandin (PG)I2 has a regulatory role in allergic responses through the receptor, IP; however, the role of PGI2 in airway remodeling associated with chronic airway inflammation has not been elucidated. In the present study, we examined the role of PGI2 in allergen-induced airway remodeling using IP gene–deficient mice. Mice were sensitized to ovalbumin (OVA) with alum, and exposed daily for 3 wk to aerosolized OVA. Twenty-four hours after the final antigen inhalation, bronchoalveolar lavage, biochemical, and histopathologic examinations were performed. In wild-type mice, prolonged allergen exposure in sensitized animals induced the increases in the numbers of inflammatory leukocytes (including eosinophils and lymphocytes), levels of T helper type 2 (Th2) cytokines (interleukin [IL]-4, IL-5, and IL-13), levels of OVA-specific immunoglobulin (Ig)E and IgG1 in serum, and amount of hydroxyproline in the right lungs associated with transforming growth factor-ß1 levels in bronchoalveolar lavage fluid. Moreover, goblet cell hyperplasia and subepithelial fibrosis were also appreciated after repeated allergen challenge. In contrast, the disruption of IP gene significantly augmented all these parameters. These findings suggest that PGI2 has a regulatory role in allergen-induced airway remodeling as well as airway eosinophilic inflammation, Th2 cytokine production and IgE production, and that a PGI2 agonist is a therapeutic approach for the treatment of airway remodeling in allergic asthma.

Abbreviations: bronchoalveolar lavage fluid, BALF • bovine serum albumin, BSA • enzyme-linked immunosorbent assay, ELISA • interferon, IFN • immunoglobulin, Ig • interleukin, IL • ovalbumin, OVA • periodic acid-Schiff, PAS • prostaglandin, PG • transforming growth factor, TGF • T helper type 2, Th2


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Bronchial asthma is an allergic disease characterized by variable airflow obstruction, airway eosinophilic inflammation, and airway hyperresponsiveness (1). Recently, many studies suggested that chronic airway inflammation observed in the asthmatic airways cause airway remodeling characterized by structural changes, including airway wall thickening due to goblet cell hyperplasia/hypertrophy, collagen deposition beneath the basement membrane, and airway smooth muscle thickening as a result of smooth muscle cell hyperplasia/hypertrophy (2–6). All these changes are thought to contribute to airway flow limitation and airway hyperresponsiveness (7, 8); however, the mechanisms in the development of airway remodeling have not been fully understood.

Prostaglandins (PGs) are cyclooxygenase metabolites of arachidonic acid, and are generated in response to a variety of stimuli to cells. They are locally acting autacoids with pleiotropic roles in physiologic and pathophysiologic processes (9–11). Under physiologic conditions, they mainly work in the gastrointestinal tract, the circulatory system, and regenerative organs. Moreover, PGs play a role in a variety of pathophysiologic situations, including inflammation and allergic response (11).

Regarding the role of PGs in allergic airway response, Gavett and coworkers demonstrated the exaggeration of airway eosinophilia, IgE production, and airway hyperresponsiveness in cyclooxygenase-1 and cyclooxygenase-2–deficient mice (12). More recently, Peebles and colleagues reported that the inhibition of cyclooxygenase with a nonspecific inhibitor, indomethacin, augmented allergen-induced airway eosinophilia, interleukin (IL)-5 and IL-13 production in the airways, and airway hyperresponsiveness in a mouse model of allergic asthma (13). These findings strongly suggest that endogenous PG(s) play a regulatory role in allergic response.

PGI2 was produced by allergic reaction in human lung (14, 15). PGI2 also showed an inhibition of allergic mediator release and eosinophil recruitment in experimental animals (16, 17). Recently, we reported that IP-deficient mice showed the augmentation of allergic inflammation in the airway and skin, associated with the increases in vascular permeability and enhancement of T helper type 2 (Th2) response (18). These findings indicated that PGI2 may be one of PGs, which has an inhibitory role in allergic response; however, the involvement of PGI2 in airway remodeling resulted from prolonged airway eosinophilic inflammation has been never investigated in vivo.

In the present study, we examined the effect of IP receptor gene deficiency on allergen-induced airway remodeling, as well as airway eosinophilic inflammation, IgE production, and Th2 response, in a mouse model of allergic asthma.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Animals
Seven-week-old female IP receptor gene–disrupted mice (IP KO mice; 129Sv x C57BL/6 background; backcross to C57BL/6 ten times [N10]) were used as described previously (19). Age- and generation-matched female wild-type animals were used as controls. The animals were housed in plastic cages in an air-conditioned room at 22 ± 1°C with a relative humidity of 60 ± 1%, fed a standard laboratory diet, and given water ad libitum. Experiments were performed following the guidelines for the care and use of experimental animals of the Japanese Association for Laboratory Animals Science in 1987.

Agents
The following drugs and chemicals were purchased commercially and used: ovalbumin (OVA; Seikagaku Kogyo, Tokyo, Japan), bovine serum albumin (BSA; Seikagaku Kogyo), Türk solution (Wako Pure Chemical Industries, Ltd., Osaka, Japan), pancronium bromide (Sigma, St. Louis, MO), sodium pentobarbitone (Abbott Lab., Chicago, IL), Diff-Quick solution (International Reagent Corp., Ltd., Kobe, Japan), monoclonal rat anti-mouse IgE antibody (LO-ME-3; Serotec Co., Ltd., Oxford, UK), polyclonal goat anti-mouse IgG1 antibody (ST-AR81; Serotec), monoclonal rat anti-mouse IgG2a antibody (LO-MG2a-7; Serotec), peroxidase-conjugated streptavidin (Dakopatts a/s, Glostrup, Denmark) and hydroxy-L-proline (Nacalai Tesque).

Sensitization and Antigen Challenge
Experiments were performed as reported previously (20, 21). Briefly, mice were actively sensitized by intraperitoneal injections of 50 µg OVA with 1 mg alum on Days 0 and 12. Starting on Day 22, they were exposed to OVA (1% wt/vol diluted in sterile physiologic saline) for 30 min every day for three consecutive weeks. Negative control animals were injected with saline and exposed to saline or OA in a similar manner. Bronchoalveolar lavage (BAL), histopathologic examination (left lung), and the measurement of hydroxyproline content in right lungs were performed 24 h after the final antigen challenge.

BAL
To evaluate airway inflammation, we examined the accumulation of inflammatory cells in BAL fluid (BALF). Experiments were performed according to previously described methods (20, 21). Animals were killed with an intraperitoneal injection of sodium pentobarbitone (100 mg/kg). The trachea was cannulated and the left bronchi were tied for histologic examination. Then, the right air lumen was washed four times with 0.5-ml calcium- and magnesium-free phosphate-buffered saline containing 0.1% BSA and 0.05 mM EDTA-2Na. This procedure was repeated three times (total volume; 1.3 ml, recovery > 85%). BALF from each animal was pooled in a plastic tube, cooled on ice and centrifuged (150 x g) at 4°C for 10 min. Cell pellets were resuspended in the same buffer (0.5 ml). BALF was stained with Türk solution, and the number of nucleated cells was counted in a Burker chamber. A differential count was made on a smear prepared with a cytocentrifuge (Cytospin II; Shandon, Cheshire, UK) and stained with Diff-Quik solution (based on standard morphologic criteria) of at least 300 cells (magnification x 500). The supernatant of BALF was stored at -30°C for determination of IL-4, IL-5, IL-13, interferon (IFN)-{gamma}, and transforming growth factor (TGF)-ß1.

Cytokine Levels in BALF
The amount of cytokine in the supernatant of BALF was measured using enzyme-linked immunosorbent assay (ELISA; Endogen Inc., Woburn, MA) for IL-4 and IL-5, and IFN-{gamma} (R&D Systems Inc., Minneapolis, MN) for IL-13). The TGF-ß1 content in BALF was also measured using ELISA (R&D Systems Inc.), which can detect mouse TGF-ß protein, because of the high homology of TGF-ß across species. The assay detects only the active form of TGF-ß1. Each sample was activated before measuring according to the manufacturer's recommendations. The detection limit of each kit was 5 pg/ml for IL-4 and IL-5, 10 pg/ml for IFN-{gamma}, and 7 pg/ml for TGF-ß1, respectively.

Measurement of Immunoglobulins
At Week 3 (Day 43), blood was collected and sera were obtained by centrifugation and stored at -80°C. Antigen-specific IgE, IgG1, and IgG2a in the mouse serum was measured using ELISA as previously described (21). Briefly, serum OVA-specific IgE was measured by coating flat-bottom 96-well microtiter plates (Immuno-Plate I 96-F; Nunc, Roskilde, Denmark) with monoclonal rat anti-mouse IgE antibody (LO-ME-3) at a concentration of 5 µg/ml. After blocking with 1% BSA, serum dilutions were incubated for 1 h followed by biotinylated-OVA and peroxidase-conjugated streptavidin. Serum OVA-specific IgG1 was measured by coating the microtiter plates with polyclonal goat anti-mouse IgG1 antibody (STAR81) at a concentration of 2 µg/ml. After blocking with 1% BSA, serum dilutions were incubated for 1 h followed by biotinylated-OVA and peroxidase-conjugated streptavidin. Serum OVA-specific IgG2a was measured by coating the microtitier plates with OVA solution at a concentration of 20 µg/ml. After blocking with 1% BSA, serum dilutions were incubated for 1 h followed by peroxydase-conjugated monoclonal rat anti-mouse IgG2a antibody (LO-MG2a-7). Sequentially diluted monoclonal anti-OVA IgE, IgG1 and IgG2a (donated by Dr. Kiniwa, Taiho Pharmaceutical Co. Ltd., Saitama, Japan) were used as a standard.

Optical densities of the enzymatic reactions were read using an automatic ELISA plate reader (Multiscan MS, ver 8; Labsystems Oy, Helsinki, Finland) at 450 nm (reference 690 nm) and analyzed using Deltasoft 3 (Biometallics Inc., Princeton, NJ). Each detection limit was 1 ng/ml, 10 µg/ml, and 3 ng/ml for IgE, IgG1, and IgG2a, respectively.

Measurement of Hydroxyproline Content in Right Lungs
Whole collagen content of the right lung was evaluated by determining hydroxyproline content as described previously (20, 21). Briefly, after recovery of BALF, the right lung lobes were removed and cut into sections (1 mm thick). The chopped lungs were dried with acetone. Then, the dried lung samples were hydrolyzed with 2 ml of 6N HCl at 120°C for 24 h in sealed glass tubes. The amount of hydroxyproline in the hydrolysate was measured according to Kivirikko and coworkers (22). Authentic hydroxyproline (hydroxy-L-proline) was used to establish a standard curve.

Histopathologic Study
The left lungs were distended with 10% buffered formalin via the trachea (10 cm H2O) for 30 min, and then excised and immersed in the fresh fixative for 24 h. Tissues were sliced and embedded in paraffin, and 6-µm sections were stained with periodic acid-Schiff (PAS) and Masson-Trichrome for light microscopy examination. Section analyses, described below in detail, were performed in a blind fashion, and slides were presented in random order for each examination.

Examination of goblet cell hyperplasia was performed using a method previously described by Padrid et al. (23) with a slight modification (20, 21) using a Leica image analysis system (Leica, Cambridge, UK). Briefly, 2–4 specimens of the PAS-stained histologic preparations of the left lobe, in which the total length of the epithelial basement membrane of the bronchioles were 1.0–2.5 mm, were selected, and the pathologic changes were evaluated according to the modified 5-point scoring system (20) using the Leica microscope (x20 objectives). The preparations, in which the maximum internal diameter of the bronchioles were >= 2-fold as large as the minimum internal diameter, were not used for analysis. The hyperplasia of the goblet cells in the epithelial lining was expressed by a score according to the percentage of the goblet cells in the epithelial cells. To minimize sampling errors, the 5-point scoring system (grade 0–4) (20) was adopted: grade 0 (no goblet cells); grade 1, < 25%; grade 2, 25–50%; grade 3, 50–75%; grade 4, >= 75%. The mean score of the total epithelial cells in 2–4 preparations of one mouse were counted. The mean scores of hyperplasia of the goblet cells were calculated in 5–6 animals.

Examination of subepithelial fibrosis was performed using a method previously described by Komai and colleagues (21) using a Leica image analysis system (Leica). Briefly, 2–4 specimens of the Masson-trichrome–stained histologic preparations of the left lobe, in which the total length of the epithelial basement membrane of the bronchioles was 1.0–2.5 mm, were selected and the fibrotic area (stained in blue) beneath the basement membrane in 20 µm depth was measured. The mean score of the fibrotic area divided by basement membrane length in 2–4 preparations of one mouse were calculated, then the mean values of subepithelial fibrosis were calculated in 5–6 animals.

Statistical Analysis
Values are presented as the mean ± SEM. Statistical significance between two groups was estimated using the two-tailed Student's t test or the Mann-Whitney U test after the variances of the data were evaluated with F-test. P values less than 0.05 were considered to be significant.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Inflammatory Cells and Cytokine Production in BALF
To clarify whether the deficiency of IP receptor influenced the development of airway remodeling, we examined the accumulation of inflammatory leukocytes in BALF of IP-deficient mice compared with those of wild-type mice. In wild-type mice, prolonged antigen exposure in sensitized mice induced the significant increases in the numbers of total leukocytes, eosinophils, and lymphocytes in BALF. In contrast, the increases in the numbers of total leukocytes, eosinophils, and lymphocytes in IP KO mice were significantly augmented compared with those in wild-type mice (Figure 1).



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  		Figure 1. Effect of IP gene deficiency on allergen-induced increases in the numbers of total leukocytes, eosinophils, and lymphocytes in BALF in mice. Twenty-four hours after the final allergen challenge, BAL was performed. In sensitized wild-type mice, repeated allergen challenge induced the significant increases in the numbers of total leukocytes, eosinophils, and lymphocytes in BALF compared with that in nonsensitized animals. In contrast, the increases were significantly augmented in IP-deficient micecompared with those in wild-type animals. Values represent the mean ± SEM of 5–6 mice in each group. NS, nonsensitized; S, sensitized; Sal, saline-exposed; OVA, ovalbumin-exposed. **P < 0.01 (versus NS-Sal group); {dagger}P < 0.05, {dagger}{dagger}P < 0.01 (versus wild-type).

 
Associated with inflammatory infiltrates, the amount of IL-4, IL-5, and IL-13 in BALF was significantly increased after sensitization and allergen exposure in wild-type mice (Table 1). In contrast, sensitization and repetitive antigen provocation tended to decrease the amount of IFN-{gamma} in BALF of wild-type mice. The deficiency of IP gene, however, significantly enhanced the production of IL-4 and IL-5, and tended to augment IL-13 production in BALF, whereas no significant differences were found in the decreases of the amount of IFN-{gamma} in BALF between wild-type and IP KO mice (Table 1).


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  		TABLE 1 Effect of IP gene deficiency on cytokine production in BALF after repeated allergen challenge in mice

 
Immunoglobulin Levels
After first sensitization (at Day 11), the level of antigen-specific IgE (122.4 ± 22.8 ng/ml) in IP KO mice tended to be increased compared with those of wild-type mice (84.6 ± 4.4 ng/ml), although significant differences were not found between wild-type and IP KO mice. In wild-type mice, antigen inhalation in sensitized groups induced the significant elevation of serum antigen-specific IgE, IgG1, and IgG2a at Day 43. In contrast, IP-defiscient mice showed the significant elevation of serum antigen-specific IgE (178.0 ± 12.0 ng/ml) and IgG1 (1.32 ± 0.08 mg/ml) compared with wild-type mice (137.5 ± 15.5 ng/ml and 0.78 ± 0.08 mg/ml, respectively), but no differences were found in antigen-specific IgG2a between wild-type (2.76 ± 0.33 µg/ml) and IP KO mice (3.19 ± 0.45 µg/ml).

Fibrogenic Responses
To investigate the roles of PGI2 in the fibrogenic responses, we examined the production of a fibrogenic cytokine, TGF-ß1, in BALF, and the amount of hydroxyproline, which is an amino acid specifically consisting of collagen, in the right lung tissues after the final antigen challenge. In wild-type mice, the levels of active formed TGF-ß1 in BALF were significantly increased after sensitization and repeated antigen inhalation (Table 2). In addition, associated with TGF-ß1 production, the amount of hydroxyproline in the right lungs of sensitized wild-type mice was significantly increased after the repetitive allergen challenge compared with those in nonsensitized animals. In contrast, the disruption of IP gene clearly augmented these parameters by 248% and 138%, respectively (Table 2).


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  		TABLE 2 Effect of IP receptor gene deficiency on allergen-induced airway remodeling in mice ||

 
Histologic Analysis
To clarify the roles of PGI2 in the development of the structural changes, the left lungs were histologically examined 24 h after the final antigen inhalation.

Figure 2 shows the histologic examination with PAS staining for detection of goblet cells (A–D) and with Masson-Trichrome staining for detection of fibrotic area (E–H). In wild-type mice, all of the OVA-exposed sensitized mice demonstrated moderate to severe goblet cell hyperplasia compared with nonsensitized animals (Figure 2B versus Figure 2A, examined quantitatively in Table 2). The number of goblet cells and the ratio of goblet cells lining the epithelium were increased after sensitization and antigen challenge. Moreover, sensitized and OVA-exposed wild-type animals showed collagen deposition beneath the basement membrane of the bronchi compared with those in nonsensitized animals (Figure 2F versus Figure 2E, examined quantitatively in Table 2). In contrast, IP gene disruption significantly enhanced these epithelial changes and subepithelial fibrosis compared with wild-type mice (Figures 2D and 2H). These results were confirmed by the findings in significant augmentation of goblet cell scores and fibrotic area (Table 2).



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  		Figure 2. Histolopathologic examination of lung sections stained with PAS (A–D) and with Masson-trichrome (E–H) 24 h after the final antigen challenge in IP gene knockout (KO) mice or wild-type mice. In wild-type mice, all OVA-exposed sensitized mice (B) demonstrated moderate to severe goblet cell hyperplasia and collagen deposition beneath the basement membrane of the airways (F) compared with nonsensitized animals (A and E, respectively). In contrast, IP gene deficiency significantly exaggerated these airway remodeling (D and H) compared with wild-type animals (these results were confirmed quantitatively in Table 2). (original magnification: x50). A and E, nonsensitized, OVA-exposed wild-type mice; B and F, sensitized, ovalbumin-exposed wild-type mice; C and G, nonsensitized, OVA-exposed IP KO mice; D and H, sensitized, ovalbumin-exposed IP KO mice.

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
In the present study, we examined the role of PGI2 in the development of airway remodeling using IP-deficient mice. Our results suggest that PGI2 plays a inhibitory role in the development of allergen-induced airway remodeling, as well as Th2 cytokine production, inflammatory infiltrates, and IgE production, in allergic asthma.

The main question to be addressed is whether IP receptors are involved in the development of allergen-induced airway remodeling. In our study, we examined goblet cell hyperplasia in the epithelium and subepithelial fibrosis after repeated allergen challenge in IP-deficient mice. As a result, OVA-challenged sensitized IP-deficient mice exhibited significant enhancement of the epithelial changes compared with those in wild-type animals. The mechanisms of goblet cell hyperplasia after allergen challenge are still unknown; however, cytokines (24–26), growth factors (26) and mediators (27, 28) have been reported as the candidates. Among these functional molecules, IL-4 and IL-13 are reported to induce goblet cell hyperplasia in vitro (24, 26) and in vivo (29, 30). In the present study, allergen challenge induced the increases in the production of these cytokines in BALF of all sensitized animals, and the deficiency of IP clearly enhanced the productions, especially IL-4. Moreover, we recently examined the effect of anti-CD4 mAb during allergen challenge and the effect of IL-4 deficiency on the epithelial changes (21). The treatment of anti-CD4 Ab completely prevented the increased level of IL-13 in BALF, and the production in IL-4–deficient mice was significantly lower than that in wild-type mice, suggesting that IL-13, as well as IL-4, produced by CD4+ Th2 cells, is a critical factor for the development of antigen-induced goblet cell hyperplasia, at least in this model. Taken together, PGI2 plays an important role in the inhibition of allergen-induced epithelial changes, probably through the suppression of these cytokine productions in the airways.

As for fibrotic changes, the degree of subepithelial fibrosis and the amount of hydroxyproline in IP KO mice were significantly higher than that in wild-type animals. The mechanism of the development of subepithelial fibrosis is also not fully elucidated. Therefore, we focused on a cytokine, TGF-ß1, which was reported to be an important factor in the pathogenesis of fibrosis, because it stimulates production of extracellular matrix and inhibits the formation of extracellular proteases (31). TGF-ß1 is thought to play an important role in asthma. For example, increased expression of TGF-ß1 in BALF and biopsy or specimens obtained from patients with asthma (32, 33), especially patients with severe asthma, has been reported (33). Furthermore, TGF-ß1 expression was found to correlate with the degree of subepithelial fibrosis (34). In the present study, the production in BALF after repeated allergen challenge in IP-deficient mice were significantly enhanced compared with that in wild-type mice. Previously, we demonstrated that the production was significantly correlated with the number of eosinophils and the increased amount of hydroxyproline in the right lungs (20), suggesting that the main source of the factor may be eosinophils in this model. In fact, antigen-induced IL-5 production was also significantly increased in IP-deficient mice, which was associated with the increase in the number of eosinophils in BALF. In addition, eosinophils have been reported to produce TGF-ß1 (35). These findings suggest that IP deficiency congenitally upregulates Th2 response, including IL-5 production, and that increased number of eosinophils participate in the exaggeration of subepithelial fibrosis, probably through the production of TGF-ß1 in the airways. In contrast, Stratton and colleagues recently demonstrated that iloprost, a PGI2 analog, inhibited the induction of connective tissue growth factor and the increase in collagen synthesis in fibroblasts exposed to TGF-ß1 (36). Thus, it is also possible that PGI2 inhibits subepithelial fibrosis directly through the inhibition of collagen synthesis.

As we reported previously, the deficiency of IP augmented allergen-induced airway eosinophilia, Th2 cytokine production, and serum IgE production compared with that in wild-type mice (18). These phenomena were probably due to the dominance of Th2 response in IP-deficient mice over Th1 response. Recently, Jaffar and coworkers demonstrated that mRNA for IP was expressed on Th2 cells, but not on Th1 cells, and that the expression was induced by IL-4 and T cell receptor signaling (37). In the present study, the production of IFN-{gamma} in BALF and the level of serum antigen-specific IgG2a was not affected by the deficiency, whereas Th2 cytokine production in the airways and serum IgE/IgG1 responses were all enhanced. These findings suggest that PGI2 has immunomodulatory effects on T lymphocytes, especially Th2 cells.

In summary, we demonstrated that IP-deficient mice showed augmentation of the development of allergen-induced airway remodeling, probably due to the upregulation of Th2 cytokine production, IgE production, or airway eosinophilic inflammation, in a mouse model of allergic asthma. These results suggest that PGI2 plays an inhibitory role in the development of airway remodeling, and that a PGI2 analog may have a therapeutic approach to prevent the airway remodeling in asthma.


   Acknowledgments
 
The authors thank Mr. Daniel Mrozek for skillful assistance in preparation of this manuscript. This work was partly supported by Ono Medical Research Foundation and Kowa Life Science Foundation.

Received in original form February 2, 2003

Received in final form April 1, 2003


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Djukanovic, R., W. R. Roche, J. W. Wilson, C. R. Beasley, O. Twentyman, and S. T. Holgate. 1990. Mucosal inflammation in asthma. Am. Rev. Respir. Dis. 142:434–457.[Medline]
  2. Aikawa, T., S. Shimura, H. Sasaki, M. Ebina, and T. Takashima. 1992. Marked goblet cell hyperplasia with mucus accumulation in the airways of patients who died of severe acute asthma attack. Chest 101:916–921.[Abstract/Free Full Text]
  3. Ebina, M., T. Takahashi, T. Chiba, and M. Motomiya. 1993. Cellular hypertrophy and hyperplasia of airway smooth muscles underlying bronchial asthma: a 3-D morphometric study. Am. Rev. Respir. Dis. 48:720–726.
  4. Heard, B. E., and S. Hossain. 1973. Hyperplasia of bronchial muscle in asthma. J. Pathol. 110:319–331.[CrossRef]
  5. Jeffery, P. K., R. W. Godfrey, E. Adelroth, F. Nelson, A. Rogers, and S. A. Johansson. 1992. Effects of treatment on airway inflammation and thickening of basement membrane reticular collagen in asthma: a quantitative light and electron microscopy study. Am. Rev. Respir. Dis. 145:890–899.[Medline]
  6. Roche, W. R., J. H. Williams, R. Beasly, and S. T. Holgate. 1989. Subepithelial fibrosis in the bronchi of asthmatics. Lancet 1:520–524.[CrossRef][Medline]
  7. Busse, W., J. Elias, D. Sheppard, and S. Bank-Schlegel. 1999. Airway remodeling and repair. Am. J. Respir. Crit. Care Med. 160:1035–1042.[Free Full Text]
  8. Elias, J. A., Z. Zhu, G. Chupp, and R. J. Homer. 1999. Airway remodeling in asthma. J. Clin. Invest. 104:1001–1006.[Medline]
  9. Narumiya, S., and G. A. FitzGerald. 2001. Genetic and pharmacological analysis of prostanoid receptor function. J. Clin. Invest. 108:25–30.[CrossRef][Medline]
  10. Smith, W. L., and R. Langenbach. 2001. Why there are two cyclooxygenase isozymes. J. Clin. Invest. 107:1491–1495.[Medline]
  11. Tilley, S. L., T. M. Coffman, and B. H. Koller. 2001. Mixed messages: modulation of inflammation and immune responses by prostaglandins and thromboxanes. J. Clin. Invest. 108:15–23.[CrossRef][Medline]
  12. Gavett, S. H., S. L. Madison, P. C. Chulada, P. E. Scarborough, W. Qu, J. E. Boyle, H. F. Tiano, C. A. Lee, R. Langenbach, V. L. Roggi, and D. C. Zeldin. 1999. Allergic lung responses are increased in prostaglandin H synthase-deficient mice. J. Clin. Invest. 104:721–732.[Medline]
  13. Peebles, R. S., Jr., R. Dworski, R. D. Collins, K. Jarzecka, D. B. Mitchell, B. S. Graham, and J. R. Sheller. 2000. Cyclooxygenase inhibition increases interleukin 5 and interleukin 13 production and airway hyperresponsiveness in allergic mice. Am. J. Respir. Crit. Care Med. 162:676–681.[Abstract/Free Full Text]
  14. Dahlen, S. E., G. Hansson, P. Hedqvist, T. Bjorck, E. Granstrom, and B. Dahlen. 1983. Allergen challenge of lung tissue from asthmatics elicits bronchial contraction that correlates with the release of leukotriene C4, D4, and E4. Proc. Natl. Acad. Sci. USA 80:1712–1716.[Abstract/Free Full Text]
  15. Schulman, E. S., H. H. Newball, L. M. Demers, F. A. FitzPatrick, and N. F. Adkinson. 1981. Anaphylactic release of thromboxane A2, prostaglandin D2, and prostacyclin from human lung parenchyma. Am. Rev. Respir. Dis. 124:402–406.[Medline]
  16. Burka, J. F., and L. G. Garland. 1977. A possible modulatory role for prostacyclin (PGI2) INIgGa-induced release of slow-reacting substance of anaphylaxis in rats. Br. J. Pharmacol. 61:697–699.[Medline]
  17. Lellouch-Tubiana, A., J. Lefort, M. T. Simon, A. Pfister, and B. B. Vargaftig. 1988. Eosinophil recruitment into guinea pig lungs after PAF-acether and allergen administration: modulation by prostacyclin, platelet depletion, and selective antagonists. Am. Rev. Respir. Dis. 137:948–954.[Medline]
  18. Takahashi, Y., S. Tokuoka, T. Masuda, Y. Hirano, M. Nagao, H. Tanaka, N. Inagaki, and H. Nagai. 2002. Augmentation of allergic inflammation in prostanoid IP receptor deficient mice. Br. J. Pharmacol. 137:315–322.[CrossRef][Medline]
  19. Murata, T., F. Ushikubi, T. Matsuoka, M. Hirata, A. Yamasaki, Y. Sugimoto, A. Ichikawa, Y. Aze, T. Tanaka, N. Yoshida, A. Ueno, S. Oh-ichi, and N. Narumiya. 1997. Altered pain perception and inflammatory response in mice lacking prostacyclin receptor. Nature 388:678–682.[CrossRef][Medline]
  20. Tanaka, H., T. Masuda, S. Tokuoka, M. Komai, M. Nagao, Y. Takahashi, and H. Nagai. 2001. The effect of allergen-induced airway inflammation on airway remodeling in a murine model of allergic asthma. Inflamm. Res. 50:616–624.[CrossRef][Medline]
  21. Komai, M., H. Tanaka, T. Masuda, K. Nagao, M. Ishizaki, M. Sawada, and H. Nagai. 2003. Role of Th2 responses in the development of allergen-induced airway remodelling in a murine model of allergic asthma. Br. J. Pharmacol. 138:912–920.[CrossRef][Medline]
  22. Kivirikko, K. I., O. Laitinen, and D. J. Prockop. 1967. Modifications of a specific assay for hydroxyproline in urine. Anal. Biochem. 19:249–255.[CrossRef][Medline]
  23. Padrid, P., S. Snook, T. Finucane, P. Shiue, P. Cozzi, J. Solway, and A. R. Leff. 1995. Persistent airway hyperresponsiveness and histologic alterations after chronic antigen challenge in cats. Am. J. Respir. Crit. Care Med. 151:184–193.[Abstract]
  24. Dabbagh, K., K. Takeyama, H. M. Lee, I. F. Ueki, J. A. Lausier, and J. A. Nadel. 1999. IL-4 induces mucin gene expression and goblet cell metaplasia in vitro and in vivo. J. Immunol. 162:6233–6237.[Abstract/Free Full Text]
  25. Longphre, M., D. Li, M. Gallup, E. Drori, C. L. Ordonez, T. Redman, S. Wenzel, D. E. Bice, J. V. Fahy, and C. Basbaum. 1999. Allergen-induced IL-9 directly stimulates mucin transcription in respiratory epithelial cells. J. Clin. Invest. 104:1375–1382.[Medline]
  26. Shim, J. J., K. Dabbagh, I. F. Ueki, T. Dao-Pick, P. R. Burgel, K. Takeyama, D. C. Tam, and J. A. Nadel. 2001. IL-13 induces mucin production by stimulating epidermal growth factor receptors and by activating neutrophils. Am. J. Physiol. 280:L134–L140.
  27. Lou, Y. P., K. Takeyama, K. M. Grattan, J. A. Lausier, I. F. Ueki, C. Aguti, and J. A. Nadel. 1998. Platelet-activating factor induces goblet cell hyperplasia and mucin gene expression in airways. Am. J. Respir. Crit. Care Med. 157:1927–1934.
  28. Tamaoki, J., J. Nakata, K. Takeyama, A. Chiyotani, and K. Konno. 1997. Histamine H2 receptor-mediated airway goblet cell secretion and its modulation by histamine-degrading enzymes. J. Allergy Clin. Immunol. 99:233–238.[CrossRef][Medline]
  29. Rankin, J. A., D. E. Picarella, G. P. Gebe, U. A. Temann, B. Prasad, B. DiCosmo, A. Tarallo, B. Stripp, J. Whitsett, and R. A. Flavell. 1996. Phenotypic and physiologic characterization of transgenic mice expressing interleukin 4 in the lung: lymphocyte and eosinophilic inflammation without airway hyperreactivity. Proc. Natl. Acad. Sci. USA 93:7821–7825.[Abstract/Free Full Text]
  30. Zhu, Z., R. J. Homer, Z. Wang, Q. Chen, G. P. Geba, J. Wang, Y. Zhang, and J. A. Elias. 1999. Pulmonary expression of interleukin-13 causes inflammation, mucus hypersecretion, subepithelial fibrosis, physiological abnormalities, and eotaxin production. J. Clin. Invest. 103:779–788.[Medline]
  31. Blobe, G. C., W. P. Schiemann, and H. F. Lodish. 2000. Role of transforming growth factor ß in human disease. N. Engl. J. Med. 342:1350–1358.[Free Full Text]
  32. Minshall, E. M., D. Y. Leung, R. J. Martin, Y. L. Song, L. Cameron, P. Ernst, and Q. Hamid. 1997. Eosinophil-associated TGF-beta1 mRNA expression and airways fibrosis in bronchial asthma. Am. J. Respir. Cell Mol. Biol. 17:326–333.[Abstract/Free Full Text]
  33. Redington, A. E., J. Madden, A. J. Frew, R. Djukanovic, W. R. Roche, S. T. Holgate, and P. H. Howarth. 1997. Transforming growth factor-ß1 in asthma: measurement in bronchoalveolar lavage fluid. Am. J. Respir. Crit. Care Med. 156:642–647.[Abstract/Free Full Text]
  34. Vignola, A. M., P. Chanez, G. Chiappara, A. Merendino, E. Pace, A. Rizzo, A. M. la Rocca, V. Bellia, G. Bonsignore, and J. Bousquet. 1997. Transforming growth factor-ß expression in mucosal biopsies in asthma and chronic bronchitis. Am. J. Respir. Crit. Care Med. 156:591–599.[Abstract/Free Full Text]
  35. Nomura, A., Y. Uchida, T. Sakamoto, Y. Ishii, K. Masuyama, Y. Morishima, K. Hirano, and K. Sekizawa. 2002. Increases in collagen type I synthesis in asthma: the role of eosinophils and transforming growth factor-beta. Clin. Exp. Allergy 32:860–865.[CrossRef][Medline]
  36. Stratton, R., X. Shiwen, G. Martini, A. Leask, T. Haberberger, G. R. Martin, C. M. Black, and D. Abraham. 2001. Iloprost suppresses connective tissue growth factor production in fibroblasts and in the skin of scleroderma patients. J. Clin. Invest. 108:241–250.[CrossRef][Medline]
  37. Jaffar, Z., K.-S. Wan, and K. Roberts. 2002. A key role for prostaglandin I2 in limiting lung mucosal Th2, but not Th1, responses to inhaled allergen. J. Immunol. 169:5997–6004.[Abstract/Free Full Text]



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