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American Journal of Respiratory and Critical Care Medicine Vol 166. pp. 496-500, (2002)
© 2002 American Thoracic Society

Original Article

A Novel Oral Neutrophil Elastase Inhibitor (ONO-6818) Inhibits Human Neutrophil Elastase-induced Emphysema in Rats

Takashige Kuraki, Masayoshi Ishibashi, Masanori Takayama, Motokimi Shiraishi and Minoru Yoshida

Department of Respiratory Medicine, School of Medicine, Fukuoka University, Fukuoka, Japan

Correspondence and requests for reprints should be addressed to Masayoshi Ishibashi, M.D., Respiratory Medicine, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180 Japan. E-mail: kokyuki{at}minf.med.fukuoka-u.ac.jp


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
We investigated the effects of a novel oral neutrophil elastase inhibitor (ONO-6818) on acute lung injury and pulmonary emphysema induced by human neutrophil elastase (HNE). Young male Wistar rats were divided into four treatment groups: (1) control group (saline); (2) HNE group (HNE 200 U + 0.5% carboxymethyl-cellulose [solution for ONO-6818]); (3) low-dose ONO-6818 group (HNE 200 U + ONO-6818 10 mg/kg); and (4) high-dose ONO-6818 group (HNE 200 U + ONO-6818 100 mg/kg). Saline and HNE were applied via the trachea using a microsprayer. ONO-6818 was administered orally 1 hour before HNE application. Six hours after HNE application, neutrophil counts and hemoglobin concentration in bronchoalveolar lavage fluid and lung tissue myeloperoxidase activity were determined. Eight weeks after the application, FRC, TLC, lung compliance, and mean linear intercept were estimated. ONO-6818 attenuated dose-dependently HNE-induced increases in lung myeloperoxidase activity, hemoglobin, and neutrophil count in bronchoalveolar lavage fluid. Furthermore, it significantly attenuated HNE-induced increases in FRC, TLC, lung compliance, and mean linear intercept. ONO-6818 inhibited acute lung injury induced by HNE by minimizing lung hemorrhage and accumulation of neutrophils in the lung. ONO-6818 also inhibited the development of HNE-induced emphysematous changes including lung hyperinflation, degradation of elastic recoil, and airspace enlargement.

Key Words: human neutrophil elastase • acute lung injury • pulmonary emphysema • neutrophil elastase inhibitor


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Emphysema is anatomically defined as a condition characterized by abnormal and permanent enlargement of the airspace distal to the terminal bronchiole, accompanied by destruction of their walls without obvious fibrosis (1). The proteases/antiprotease imbalance hypothesis as the basis for the pathogenesis of emphysema was advocated in the 1960s (2). However, more recent studies have also established the role of inflammatory processes and oxidative stress in the pathogenesis of emphysema, although the main pathogenic mechanism remains unknown.

In this regard, the major elastolytic enzyme in the proteases/antiprotease theory has not been confirmed. Matrix metalloproteinases (MMPs) degrade all components of the extracellular matrix of lung parenchyma. MMP-12 knockout mice do not develop cigarette smoke–induced emphysema (3), and high concentrations of MMPs have been described in bronchoalveolar lavage fluid (BALF) and lung tissues of patients with emphysema (4, 5). The latter studies suggested that MMPs are critical mediators in smoking-related emphysema. Neutrophil elastase, a neutral serine protease, is a major constituent of lung elastolytic activity and has various biologic activities such as potent stimulation of mucus secretion. Neutrophil elastase also induces the release of interleukin (IL)-8 from epithelial cells and may perpetuate the inflammatory process (6). Recently, a number of studies re-evaluated the role of neutrophil elastase in cigarette smoking–related emphysema. Cigarette smoke can induce acute connective tissue breakdown and this effect is mediated by neutrophil-derived serine proteases, most likely neutrophil elastase (7). High concentrations of neutrophil elastase-{alpha}1 protease inhibitor complex in BALF are often present in patients with subclinical emphysema, relative to those in current smokers without emphysema (8).

Protease inhibitors could be considered as therapeutically useful agents. Several human neutrophil elastase (HNE) inhibitors, both synthetic and natural, reversible or irreversible, have been evaluated biologically and found to inhibit HNE both in vitro and in vivo with varying degrees of success (9). In the present study, we used a diffuse emphysema model induced by spraying HNE onto the trachea, and investigated the effect of a novel oral neutrophil elastase inhibitor (ONO-6818) on pulmonary emphysema in rats.


   METHODS
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Human sputum elastase (SE563; Elastin Products, Owensville, MO) was used without further purification (10). A novel oral neutrophil inhibitor (ONO-6818: C23H28N6O4, molecular weight: 452.51) was obtained from Minase Research Institute of ONO Pharmaceutical Co. (Osaka, Japan) (11). The inhibitory activity of ONO-6818 (Ki value) against neutrophil elastases from humans is 12.16 nmol/L. Studies were performed in young male Wistar rats weighing 228 ± 15 g (mean ± SD). This study was approved by the animal experimental guidance committee of Fukuoka University.

The Rat Emphysema Model
Rats were divided into three groups: (1) control group (rats were treated with saline); (2) HNE low-dose group (rats received 200 U HNE); and (3) HNE high-dose group (rats received 400 U HNE). HNE solution was sprayed above the carina of trachea using a microsprayer (Delong Distributors Servicing the Biosciences, Long Branch, NJ) without tracheotomy. Eight weeks after HNE application, rats were killed and lungs were dissected out to evaluate the morphologic changes.

Effects of Neutrophil Elastase Inhibitor
In these experiments, rats were divided into four groups: (1) control group (rats were treated with saline); (2) HNE group (rats received 200 U HNE + 0.5% carboxymethyl-cellulose [CMC]); (3) low-dose ONO-6818 group (rats received 200 U HNE + 10 mg/kg ONO-6818); and (4) high-dose ONO-6818 group (rats received 200 U HNE + 100 mg/kg ONO-6818). ONO-6818 was dissolved into 0.5% CMC at 5 ml/kg (11), and administered orally 1 hour before HNE application. Six hours after HNE application, lung hemorrhage and neutrophil accumulation in the lung were determined. Eight weeks after the application, the functional and morphologic changes were estimated.

Lung Hemorrhage and Neutrophil Accumulation in the Lung
After tracheostomy, bronchoalveolar lavage was performed (12) for determination of neutrophil counts (13) and hemoglobin in lavage fluid as described previously (11, 14). In addition, neutrophil accumulation within the lung tissue was estimated using the myeloperoxidase (MPO) activity assay described by Goldblum and coworkers (15). After washing out the lung vessels with 20 ml saline, the lungs were weighed and homogenized. MPO activity was expressed in international units per gram of dry tissue (13).

Lung Volumes and Pulmonary Mechanics
Eight weeks after HNE application, rats were anesthetized with 30 mg/kg pentobarbital sodium intraperitoneally and tracheotomy was performed. Using a whole-body pressure plethysmograph for small animal (Chest, Tokyo, Japan), the FRC, total lung capacity (TLC), and static lung compliance (Cst) were measured as described previously (16, 17). TLC represented the maximum volume at an airway pressure of 25 cm H2O.

Mean Linear Intercept
The lungs were removed and subsequently fixed at an airway pressure of 25 cm H2O for 24 hours (18). For all five lobes of each rat, alveolar intercepts were counted microscopically from 20 fields for each lobe, then mean linear intercept (Lm) was calculated as described previously (19).

Statistical Analysis
All data are presented as mean ± SD. Differences between groups were evaluated for statistical significance using one-way analysis of variance. A p value less than 0.05 was considered statistically significant.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Rat Model of Diffuse Emphysema
Tracheal application of HNE induced emphysematous changes in all lung lobes, including lobus cranials, lobus medius, lobes caudalis, lobus accessorius, and left lung. Table 1 shows morphologic changes consistent with emphysema in HNE-treated groups. The mean Lm value of all lobes increased significantly from 61.6 ± 3.5 µm in the control group to 79.3 ± 8.0 µm in the HNE 200 U group and 86.5 ± 14.0 µm in the HNE 400 U group. In each treatment group, the mean value of Lm for each lobe was similar across the five lobes (61.3–62.5 µm in the control group, 75.3–83.0 µm in the HNE 200 U group, and 84.1–89.0 µm in the HNE 400 U group). Because HNE 200 U treatment induced emphysematous changes in all lobes, we used this dose in the remaining experiments.


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  		TABLE 1. Mean linear intercept in each lobe (µm)

 
Effects of ONO-6818 on HNE-induced Acute Lung Injury
Lung hemorrhage.
Tracheal application of HNE resulted in severe lung hemorrhage, as demonstrated by increased hemoglobin (Hb) concentration in BALF. Hb concentration was not detected in the control group, but significantly increased to 0.068 ± 0.019 g/dl in the HNE group. At a dose of 10 mg/kg, ONO-6818 significantly reduced Hb in BALF to 0.030 ± 0.014 g/dl (p < 0.01), and the reduction was even larger when ONO-6818 was administered at 100 mg/kg (0.022 ± 0.008 g/dl, p < 0.01). These results showed that orally administered ONO-6818 at 1 hour before elastase application significantly and dose-dependently inhibited lung hemorrhage (Figure 1) .



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  		Figure 1. Effects of ONO-6818 on hemoglobin concentration in BALF of rats with HNE-induced acute lung injury. Hemoglobin concentration in BALF increased significantly within 6 hours of HNE treatment. ONO-6818 administration, 1 hour before HNE treatment, attenuated dose-dependently the increases in hemoglobin in BALF. Data are mean ± SD.

 
Neutrophil accumulation in lungs.
Neutrophil count in BALF was significantly higher in the HNE group (650 ± 290/mm3) compared with the control group (190 ± 80/mm3, p < 0.01). Such increase was significantly suppressed by administration of 100 mg/kg ONO-6818 (10 mg/kg: 310 ± 170, p = 0.057; 100 mg/kg: 160 ± 70/mm3, p < 0.01; Figure 2A) . Furthermore, HNE significantly increased MPO concentrations in the lung tissue from a control level of 18.2 ± 2.6 to 33.3 ± 4.5 U (p < 0.01; Figure 2B). However, such increase was significantly abrogated by the ONO-6818 group (10 mg/kg: 23.4 ± 8.5, p = 0.076; 100 mg/kg: 18.3 ± 5.0 U, p < 0.01; Figure 2B). There were no significant differences in neutrophil counts and MPO levels in control rats and those treated with 100 mg/kg ONO-6818.



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  		Figure 2. Effects of ONO-6818 on neutrophil accumulation within the lungs in rats with HNE-induced acute lung injury. Neutrophil count in BALF (A) and lung MPO activity (B) increased dose-dependently within 6 hours of HNE treatment. ONO-6818 prevented the increase when applied at a high dose. Data are mean ± SD.

 
Effects of ONO-6818 on HNE-induced Emphysematous Changes
Lung volume and mechanics.
Eight weeks after administration of HNE, the mean body weight was 456 ± 41 g. There were no significant differences in body weight among the four groups. The mean FRC in the control group was 3.6 ± 1.1 ml and increased to 6.0 ± 1.6 ml in the HNE group. The increase in FRC was suppressed significantly to 4.7 ± 1.0 ml by low-dose ONO-6818 and to 3.2 ± 0.5 ml by 100 mg/kg ONO-6818. TLC25 was 10.5 ± 1.8 ml in the control group and increased to 14.0 ± 2.7 ml in the HNE group. The increase in TLC25 was suppressed significantly to 11.6 ± 1.7 ml by low-dose ONO-6818 and further suppressed to 9.7 ± 1.3 ml at 100 mg/kg (Figures 3A and 3B) . The increase in Cst was also inhibited by 10 mg/kg and 100 mg/kg. Cst was 0.47 ± 0.13 ml/cm H2O in the control group, was increased to 0.61 ± 0.08 ml/cm H2O in the HNE group, but was suppressed significantly to 0.43 ± 0.11 ml/cm H2O at 10 mg/kg and 0.43 ± 0.12 ml/cm H2O at 100 mg/kg of ONO-6818 (Figure 3C). These findings indicate that ONO-6818 dose-dependently inhibited hyperinflation and degradation of elastic recoil in HNE-treated lungs. These increases in FRC, TLC25, and Cst in the HNE group produced an upward and left shift in the pressure–volume curve of the lung. ONO-6818 resulted in recovery of the pressure–volume curve by downward and right shift.



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  		Figure 3. Effects of ONO-6818 on lung volume and mechanics in rats with HNE-induced chronic lung injury. Eight weeks after HNE treatment, pulmonary function tests were performed to evaluate the long-term effects of ONO-6818. (A) HNE-induced increase in FRC was inhibited dose-dependently by ONO-6818. (B) HNE-induced increase in TLC was also prevented by ONO-6818. (C) HNE-induced increase in quasi-static lung compliance was prevented by ONO-6818. Data are mean ± SD.

 
Histopathologic findings.
Histopathologic examination showed that oral administration of ONO-6818 inhibited the development of elastase-induced airspace enlargement and breakdown of alveoli. At the dose of 10 mg/kg ONO-6818, emphysematous changes were significantly decreased but focal emphysema lesions were present. At higher doses of 100 mg/kg ONO-6818, breakdown of alveolar walls was rarely found and the findings were similar to those in the control group (Figure 4) .



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  		Figure 4. Morphologic findings in rat lungs 8 weeks after treatment. (a) Control group. (b) HNE group. (c) Low-dose ONO-6818 group. (d) High-dose ONO-6818 group. Eight weeks after HNE treatment induced enlarged and abnormal airspace (b). Administration of ONO-6818 significantly decreased emphysematous change (c and d), but focal emphysema lesions were present at the dose of 10 mg/kg ONO-6818 (c) (hematoxylin and eosin stain; original magnification x39.6).

 
Mean Lm.
The mean Lm increased from 58.0 ± 1.8 µm in the control group to 73.46 ± 2.8 µm in the HNE group. The latter increase was abrogated by ONO-6818 (10 mg/kg: 63.6 ± 2.1 µm, p < 0.01; 100 mg/kg: 58.9 ± 2.1 µm, p < 0.01; Figure 5) . These results indicated that tracheal application of HNE at 200 U induced a distinct increase of Lm, whereas ONO-6818 prevented the increase in Lm dose-dependently. Furthermore, measurement of Lm showed that ONO-6818 prevented airspace enlargement induced by HNE.



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  		Figure 5. Effects of ONO-6818 on airspace enlargement in rats with HNE-induced chronic lung injury. Overall airspace size in lung tissues was determined by measurement of the mean linear intercept (Lm). Eight weeks after HNE administration, oral administration of ONO-6818 1 hour before HNE treatment prevented the increase in Lm dose-dependently. Data are mean ± SD.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
The main findings of the present study were the following: (1) HNE caused lung hemorrhage and neutrophil accumulation into the lungs during the acute phase; (2) HNE caused lung hyperinflation, degradation of the elastic recoil, and airspace enlargement during the chronic phase; and (3) pretreatment with ONO-6818 inhibited both acute lung injury and emphysematous changes induced by HNE, and these effects were dose-dependent, with more potent effects noted at 100 mg/kg.

To prevent proteolysis, plasma and interstitial fluid contain potent proteinase inhibitors such as {alpha}1-proteinase inhibitor, {alpha}2-macrogloblin, and secretory leukoproteinase inhibitor, which usually regulate the activity of enzymes released into the extracellular space. However, the antielastase activity of these compounds is suppressed by oxidative stress. About 20 years ago, several HNE inhibitors—synthesized, reversible, or irreversible—were evaluated biochemically and showed inhibition of HNE both in vitro and in vivo with varying degrees of success, but exhibited toxic side effects (9). However, few low–molecular weight inhibitors of HNE have been developed that are able to access the subjacent area between the neutrophil and its substration, to achieve maximal effects without toxicities. The effects of a number of neutrophil elastase inhibitors have been reported. Among these new agents, FR901277 inhibits HNE, PPE, and chymotrypsin-type serine proteinases (20), and ICI200.880 and SC39026 are specific inhibitors of HNE (21, 22), whereas MR889, ONO5046, and FK706 specifically inhibit HNE and PPE (23–25). Among these drugs, MR889 is administered orally and has already been tested in humans. Furthermore, the protective effects of FR901277 and ICI200.880 have also been described in animal models of chronic emphysema (20, 21).

ONO-6818, a low–molecular weight compound (MW: 452), is a specific, reversible, and nonpeptide neutrophil elastase inhibitor (11). This agent competitively inhibits neutrophil elastase in humans, rats, and hamsters, but does not inhibit other proteases such as porcine pancreatic elastase, trypsin, proteinase 3, cathepsin G, or MMPs (11). Thus, ONO-6818 might attenuate lung injury by directly inhibiting the decomposition of elastin or collagen by neutrophil elastase. However, the compound itself has no direct effect on elastin or collagen (Dr. Kazuyuki Ohmoto, Minase Research Institute of ONO Pharmaceutical Co., Osaka, Japan, personal communication).

Various animal models of protease-induced emphysema have been reported previously (26). In these models, emphysema could be induced by papain, pancreatic elastase, or HNE (26). Recently, many low–molecular weight synthetic inhibitors of HNE have been reported, and their in vivo effects have often been evaluated by assessing the severity of lung hemorrhage or the extent of emphysematous changes in hamsters after intratracheal instillation of HNE. However, animal models of HNE-induced emphysema reported earlier showed only slight changes in pulmonary function, and the dose required to induce emphysematous changes was lethal due to severe hemorrhage (20). Furthermore, intratracheal instillation with gravity resulted in increased lung volume and airspace enlargement, but these changes were noted only on the dependent side (27). In the present study, we used a microspray to apply HNE to the airway, and this technique induced emphysematous changes that were evident histopathologically in all lobes (Table 1), functionally (e.g., FRC and TLC25), and mechanically (Cst), at a dose that was not associated with any mortality.

The underlying mechanisms of emphysema include inflammatory processes in the lung and airways. Cigarette smoke and other irritants activate macrophages and airway epithelial cells in the respiratory tract, which release neutrophil chemotactic factors, including IL-8 and leukotriene (LT) B4. Neutrophils and macrophages then release proteases that break down the connective tissue in the lung parenchyma, resulting in emphysema (28). In animal models of HNE-induced emphysema, development of emphysema depends on the inflammatory process induced by HNE itself in addition to the elastolytic activity of the above mediators. Furthermore, HNE also has certain important biologic activities that induce IL-8, other proteases like cathepsins (29), and HNE-{alpha}1AT complex. The latter in turn induces TNF-{alpha} and other chemoattractants and activate macrophages.

To prevent tissue degradation in subjects with emphysema (with the exception of those with {alpha}1AT deficiency), the use of HNE inhibitors has been considered to (1) reduce HNE-induced proteolysis, (2) reduce inflammatory cell migration, (3) reduce chemokines release or blocking (13), (4) reduce the response to chemoattractants or suppress access of these compounds through the endothelium, and (5) block the inflammatory process (30).

Our results demonstrated that ONO-6818 administered orally 1 hour before HNE treatment inhibited lung hemorrhage and neutrophil accumulation in the lung during the acute phase. These results suggest that ONO-6818 suppressed HNE-induced elastolysis and neutrophil migration. The long-term effects described in our study also reflected suppression of emphysematous changes in the lung by ONO-6818. These findings suggest that inhibition of elastolysis and neutrophil migration into the lung during the acute phase prevented the subsequent development of emphysema without direct inhibition of cathepsins and MMPs.

In our study, lung hemorrhage was not completely blocked by a high dose of ONO-6818. ONO-6818 is a specific inhibitor of HNE and therefore might be independent of the inflammatory process that involves cathepsins and MMPs (29). Other studies have reported the effects of other low–molecular weight elastase inhibitors. FK706, ONO5046, and FR901277 have been used for lung hemorrhage induced by intratracheal administration of HNE (20, 24, 25). Pretreatment with such agents administered intratracheally or intravenously completely inhibited lung hemorrhage in hamster models. However, oral administration of FK706 and FR901277 before HNE administration significantly but weakly inhibited lung hemorrhage (20, 25). Only ICI200.880 was reported to inhibit white blood cell accumulation induced by intratracheal administration of HNE, and pretreatment with this agent prevented increases in total cell count in BALF (21).

A few reports have investigated the long-term effects of HNE on pulmonary emphysema (20, 21). ICI 200,800, a specific inhibitor of HNE, reduced high Lm levels in hamsters when administered intratracheally 8 weeks after instillation of HNE (21). Pretreatment with FR901277, a nonspecific serine protease inhibitor, administered intratracheally significantly but incompletely inhibited PPE-induced increases in VC and Cst (20). To our knowledge, there are no reports that have previously shown the effects of low molecular elastase inhibitors on FRC, TLC, Cst, or Lm in the HNE-induced emphysema model. In the present study, pretreatment with ONO-6818 attenuated the loss of elastic recoil in low doses, and inhibited both changes of mechanics and airspace enlargement in high doses (Figure 6) .



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  		Figure 6. Effects of ONO-6818 on airspace enlargement and mechanics in rats with HNE-induced chronic lung injury. HNE treatment induced enlargement of airspace and abnormal increase of Cst after eight weeks. Administration of ONO-6818 prevented the increase of Cst in low doses and inhibited the increase of both Lm and Cst in high doses. Open circles: control group; closed circles: HNE group; open squares: ONO-6818 low-dose group; closed squares: ONO-6818 high-dose group. Data are mean ± SD.

 
It is still unknown whether neutrophil elastase is the major elastolytic enzyme in smoke-related emphysema. In mice exposed to whole cigarette smoke, acute connective tissue breakdown is prevented by human {alpha}1-antitrypsin, and mediated by neutrophil-derived serine proteases, most likely neutrophil elastase (7). Further studies using ONO-6818 should explain the role of HNE in cigarette smoke–related emphysema and its importance clinically.

In summary, we demonstrated in the present study that a novel oral neutrophil elastase inhibitor, ONO-6818, could inhibit lung hemorrhage and accumulation of neutrophils in the lung during the acute phase of lung injury induced by HNE. Long-term studies showed that administration of the same inhibitor at 8 weeks after HNE prevented HNE-induced emphysema, which was evident by minimization of lung hyperinflation, correction of elastic recoil, and prevention of airspace enlargement.

Received in original form March 27, 2001; accepted in final form May 20, 2002


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Snider GL, Kleinerman J, Thurlbeck WM, Bengali ZH. The definition of emphysema. Am Rev Respir Dis 1985;132:182–185.[Medline]
  2. Senior RO, Anderson NR. Chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998;157:s139–s147.[Free Full Text]
  3. Hautamaki RD, Kobayashi DK, Senior RM, Shapiro SD. Requirement for macrophage elastase for cigarette smoke-induced emphysema in mice. Science 1997;277:2002–2004.[Abstract/Free Full Text]
  4. Finlay GA, O'Driscoll LR, Russell KJ, D'Arcy EM, Masterson JB, FitzGerald MX, O'Connor CM. Matrix metalloproteinase expression and production by alveolar macrophages in emphysema. Am J Respir Crit Care Med 1997;156:240–247.[Abstract/Free Full Text]
  5. Ohnishi K, Takagi M, Kurokawa Y, Satomi S, Konttinen YT. Matrix metalloproteinase-mediated extracellular matrix protein degradation in human pulmonary emphysema. Lab Invest 1998;78:1077–1087.[Medline]
  6. Nakamura H, Yoshimura K, McElvaney NG, Crystal RG. Neutrophil elastase in respiratory epithelial lining fluid of individuals with cystic fibrosis induces interleukin-8 gene expression in a human bronchial epithelial cell line. J Clin Invest 1992;89:1478–1484.
  7. Dhami R, Gilks B, Xie C, Zay K, Wright JL, Churg A. Acute cigarette smoke-induced connective tissue breakdown is mediated by neutrophils and prevented by {alpha}1-antitrypsin. Am J Respir Cell Mol Biol 2000;22:244–252.[Abstract/Free Full Text]
  8. Yoshioka A, Betsuyaku T, Nishimura M, Miyamoto K, Kondo T, Kawakami Y. Excessive neutrophil elastase in bronchoalveolar lavage fluid in subclinical emphysema. Am J Respir Crit Care Med 1995;152:2127–2132.[Abstract]
  9. Powers JC. Synthetic elastase inhibitors: prospects for use in the treatment of emphysema. Am Rev Respir Dis 1983;127:S54–S58.[Medline]
  10. Green BG, Weston H, Ashe BM, Doherty J, Finke P, Hagmann W, Lark M, Mao J, Maycock A, Moore V, et al. PMN Elastase: a comparison of the specificity of human isozymes and the enzyme from other species toward substrates and inhibitors. Arch Biochem Biophys 1991;286: 284–292.[CrossRef][Medline]
  11. Ohmoto K, Yamamoto T, Okuma M, Horiuchi T, Imanishi H, Odagaki Y, Kawabata K, Sekioka T, Hirota Y, Matsuoka S, et al. Development of orally active nonpeptidic inhibitors of human neutrophil elastase. J Med Chem 2001;44:1268–1285.[CrossRef][Medline]
  12. Mauderly JL. Bronchopulmonary lavage of small laboratory animals. Lab Anim Sci 1977;27:255–261.[Medline]
  13. Takayama M, Ishibashi M, Ishii H, Kuraki T, Nishida T, Yoshida M. Effect of neutrophil elastase inhibitor (ONO-5046) on lung injury after intestinal ischemia-reperfusion. J Appl Physiol 2001;91:1800–1807.[Abstract/Free Full Text]
  14. Clarke BS. A method for occult blood in faeces using non-carcinogenic regents. Med Lab Technol 1971;28:187–190.[Medline]
  15. Goldblum SE, Wu KM, Jay M. Lung myeloperoxidase as a measure of pulmonary leukocytosis in rabbits. J Appl Physiol 1985;59:1978–1985.[Abstract/Free Full Text]
  16. Koo KW, Leith DE, Sherter CB, Snider GL. Respiratory mechanics in normal hamsters. J Appl Physiol 1976;40:936–942.[Abstract/Free Full Text]
  17. Yoshida M, Aritomi T, Ishibasi M, Seki M, Miyahara S. Respiratory mechanics and lung volume in normal rats. Med Bull Fukuoka Univ 1987;14:167–173.
  18. Finlay GA, O'Donnell MD, O'Connor CM, Hayes JP, FitzGerald MX. Elastin and collagen remodeling in emphysema: a scanning electron microscopy study. Am J Pathol 1996;149:1405–1415.[Abstract]
  19. Thurlbeck WM. Internal surface area and other measurements in emphysema. Thorax 1967;22:483–496.[Medline]
  20. Fujie K, Shinguh Y, Yamazaki A, Hatanaka H, Okamoto M, Okuhara M. Inhibition of elastase-induced acute inflammation and pulmonary emphysema in hamsters by a novel neutrophil elastase inhibitor FR901277. Inflamm Res 1999;48:160–167.[CrossRef][Medline]
  21. Williams JC, Falcon RC, Knee C, Stein RL, Strimpler AM, Reaves B, Giles RE, Krell RD. Biologic characterization of ICI 200,880 and ICI 200,355, novel inhibitors of human neutrophil elastase. Am Rev Respir Dis 1991;144:833–875.[Medline]
  22. Gossage JR, Kuratomi Y, Davidson JM, Lefferts PL, Snapper JR. Neutrophil elastase inhibitors, SC-37698 and SC-39026, reduce endotoxin-induced lung dysfunction in awake sheep. Am Rev Respir Dis 1993; 147:1371–1379.[Medline]
  23. Luisetti M, Sturani C, Sella D, Madonini E, Galavotti V, Bruno G, Peona V, Kucich U, Dagnino G, Rosenbloom J, et al. MR889, a neutrophil elastase inhibitor, in patients with chronic obstructive pulmonary disease: a double-blind, randomized, placebo-controlled clinical trial. Eur Respir J 1996;9:1482–1486.[Abstract]
  24. Kawabata K, Suzuki M, Sugitani M, Imai K, Toda M, Miyamoto T. ONO-5046, a novel inhibitor of human neutrophil elastase. Biochem Biophys Res Commun 1991;177:814–820.[CrossRef][Medline]
  25. Shinguh Y, Imai K, Yamazaki A, Imamura N, Shima I, Wakabayashi A, Higashi Y, Ono T. Biochemical and pharmacological characterization of FK706, a novel elastase inhibitor. Eur J Pharm 1997;337:63–71.[CrossRef][Medline]
  26. Snider GL, Lucy EC, Stone PJ. Animal model of emphysema. Am Rev Respir Dis 1986;133:149–169.[Medline]
  27. Lucy EC, Stone PJ, Christensen TG, Breuer R, Snider GL. An 18-month study of the effects on hamster lungs of intratracheally administered human neutrophil elastase. Exp Lung Res 1988;14:671–686.[Medline]
  28. Barnes PJ. Chronic obstructive pulmonary disease. N Engl J Med 2000; 343:269–280.[Free Full Text]
  29. Padilla ML, Galiki NI, Kleinerman J, Orlowski M, Lesser M. High cathepsin B activity in alveolar macrophages occurs with elastase-induced emphysema but not with bleomycin-induced pulmonary fibrosis in hamsters. Am J Pathol 1988;131:92–101.[Abstract]
  30. Stockley RA. Protease/antiproteases: pathogenesis and role in therapy. Clin Pulm Med 1998;5:203–210.



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