title: Recombinant human Monocyte/Neutrophil elastase inhibitor protects rat lungs against injury from cystic fibrosis airway secretions.
abstract: Human monocyte/neutrophil elastase inhibitor (M/NEI) is a fast-acting stoichiometric inhibitor of neutrophil elastase (NE), cathepsin-G, and proteinase-3. Recombinant M/NEI (rM/NEI) was evaluated with a rat model of NE-induced lung damage. rM/NEI was found to protect against pulmonary injury caused by instilled human NE or by a preparation from airway secretions (sputum) of cystic fibrosis patients (CF sol). Human NE instilled into rat lungs produced dose-dependent hemorrhage and increased epithelial permeability, whereas NE incubated in vitro with rM/NEI did neither. Similarly, hemorrhage was induced by CF sol, but not by CF sol incubated in vitro with rM/NEI. To examine its distribution and survival time in airways, rM/NEI was labeled with the fluorochrome Texas Red (rM/NEI-TR) and instilled into rat lungs. Confocal microscopy showed that rM/NEI-TR could be detected on large airways (300 microm) at 5 min, 1 h, 4 h, and 24 h after instillation. Pretreating rats with rM/NEI was found to provide extended protection upon subsequent NE challenge, reducing hemorrhage by 98, 96, and 73%, respectively, at 1, 4, and 24 h after rM/NEI pretreatment. Pretreating rats with rM/NEI similarly conferred protection against subsequent exposure to CF sol, reducing hemorrhage by 95, 86, and 87%, respectively, at 1, 4, and 24 h after pretreatment. The findings that rM/NEI (1) mitigates protease-induced lung injury and (2) remains present and active in the lungs for 24 h after instillation strongly support its potential for treating patients with neutrophil protease-induced inflammatory lung damage, such as occurs in CF and other diseases.
authors.affiliation: Physiology Program, Harvard School of Public Health, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Rees
authors.forename: R A
authors.initials: RA
authors.lastname: Rogers
authors.forename: J
authors.initials: J
authors.lastname: Cooley
authors.forename: R J
authors.initials: RJ
authors.lastname: Mandle
authors.forename: D M
authors.initials: DM
authors.lastname: Kenney
authors.forename: E
authors.initials: E
authors.lastname: Remold-O'Donnell
mesh_terms: D000328:Adult; D000818:Animals; D003550:Cystic Fibrosis / Q000378:metabolism*; D005260:Female; D006470:Hemorrhage / Q000517:prevention & control; D006801:Humans; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors*; D008171:Lung Diseases / Q000209:etiology / Q000517:prevention & control*; D011506:Proteins / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D015842:Serine Proteinase Inhibitors / Q000627:therapeutic use*; D015843:Serpins; D013183:Sputum
chemical_list: D011506:Proteins; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins; C075177:SERPINB1 protein, human; D019272:Leukocyte Elastase