The involvement of matrix metalloproteinase-9 in airway inflammation of patients with acute asthma.
BACKGROUND
Bronchial asthma is an inflammatory disease of the airway characterized by airway remodelling, and is due at least in part to an excess of extracellular matrix (ECM) deposition in the airway wall, which leads to subepithelial collagen deposition. Matrix metalloproteinase-9 (MMP-9) is the major proteolytic enzyme that induces bronchial remodelling in asthma. MMP-9 is also important in the migration of inflammatory cells through basement membrane components.


OBJECTIVE
We evaluated whether airway inflammatory cells correlated with levels of MMP-9 in acute asthma and we examined the time course of sputum levels of MMP-9 activity in patients with spontaneous asthma exacerbation.


METHODS
We performed zymographic analysis and checked levels of MMP-9 by means of enzyme immunoassay. MMP-9 levels were also evaluated during a spontaneous attack of asthma.


RESULTS
Pro-MMP-9 activities and concentrations of MMP-9 in asthmatic patients significantly exceeded those of control subjects (P < 0.01). The activities of pro-MMP-9 were significantly higher in acute asthmatic patients than in stable asthmatic patients (P < 0.01). The elevated MMP-9 activities significantly decreased after 7 and 28 days of therapy. In acute asthmatic patients, the levels of sputum MMP-9 significantly correlated with the total macrophage + neutrophil + eosinophil cell numbers.


CONCLUSIONS
These data suggest that airway inflammation after asthma exacerbation correlates with the overproduction of MMP-9, which then leads to airway remodelling.
Lee
Y C
YC
Department of Internal Medicine, Research Institute of Clinical Medicine, Chonbuk National University Medical School, Chonju, South Korea. leeyc@moak.chonbuk.ac.kr
Lee
H B
HB
Rhee
Y K
YK
Song
C H
CH
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001249:Asthma / Q000201:enzymology / Q000378:metabolism*; D002452:Cell Count; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007958:Leukocyte Count; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism; D011014:Pneumonia / Q000201:enzymology / Q000378:metabolism*; D011237:Predictive Value of Tests; D013183:Sputum / Q000166:cytology / Q000201:enzymology
D020780:Matrix Metalloproteinase 9