Beneficial effect of an inhibitor of leukocyte elastase (EPI-hNE-4) in presence of repeated lung injuries.
Persistence of alveolar neutrophil influx and activation may enhance the fibrotic process after acute lung injury. On the other hand, elastase has an antimicrobial activity and could participate in neutrophil migration, both events being critically important in host defense, explaining the controversial issue of therapeutic elastase inhibition in the setting of acute lung injury. We assessed the effect of a neutrophil elastase inhibitor, EPI-hNE-4, in single (bleomycin, 1.2 mg/rat intratracheally) and repeated (bleomycin, 1.2 mg/rat plus endotoxin and 1 mg/kg intratracheally 24 h later) lung injuries to assess the role of neutrophil in fibrosis. Subsequently, the effect of EPI-hNE-4 on bacterial clearance was evaluated during Pseudomonas aeruginosa-induced pneumonia. In the single injury model, despite a dramatic reduction of alveolar neutrophil influx with EPI-hNE-4 treatment, no significant inhibition of the decrease in respiratory system compliance, an index of lung fibrosis, was demonstrated at day 14. In the repeated injury model, EPI-hNE-4 treatment afforded a significant protective effect on compliance and alveolar inflammation at day 14. During bacterial pneumonia, EPI-hNE4 did not modify alveolar neutrophil recruitment or bacterial clearance from bronchoalveolar lavage fluid and lung homogenate. In conclusion, EPI-hNE-4, a specific inhibitor of leukocyte elastase, afforded a partial protective effect on the respiratory system compliance during repeated lung injuries, and had no detrimental effect during a gram-negative bacterial pneumonia.
Honoré
Stéphanie
S
Unité INSERM U 492-Université Paris XII, Faculté de Médecine, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris AP-HP, Créteil, France.
Attalah
Habiba L
HL
Azoulay
Elie
E
Soussy
Claude-James
CJ
Saudubray
François
F
Harf
Alain
A
Brochard
Laurent
L
Delclaux
Christophe
C
D000818:Animals; D001761:Bleomycin / Q000494:pharmacology; D002465:Cell Movement; D016207:Cytokines / Q000378:metabolism; D004731:Endotoxins / Q000378:metabolism; D005355:Fibrosis; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors; D008168:Lung / Q000187:drug effects / Q000473:pathology; D055370:Lung Injury; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D011014:Pneumonia / Q000188:drug therapy / Q000382:microbiology; D011506:Proteins / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015843:Serpins; D013997:Time Factors
D016207:Cytokines; D004731:Endotoxins; D011506:Proteins; D015843:Serpins; D001761:Bleomycin; C075177:SERPINB1 protein, human; D019272:Leukocyte Elastase