MMP-9 protein level does not reflect overall MMP activity in the airways of patients with COPD.

Abstract

BACKGROUND:

Animal and human studies have implicated an imbalance of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the pathogenesis of chronic obstructive pulmonary disease (COPD). MMP-9 protein is increased in COPD and we hypothesized that total MMP activity would be raised although this has not previously been measured.

METHODS:

Using fluorescence and biotin labelled MMP assays, RT-PCR, western blotting and enzyme-linked immunosorbent assay we examined total MMP activity, specific gelatinase, elastase, collagenase activity, TIMP-1 and TIMP-2 in induced sputum from smokers with COPD and smokers without COPD.

RESULTS:

Induced sputum was obtained from 15 smokers with COPD and 14 smokers without COPD. MMP-9 levels were higher in those with COPD compared with controls (p<0.05). Total MMP activity, specific gelatinase, collagenase and elastase activities were not higher in COPD patients. In addition, reduced MMP activity was correlated with increasing airflow obstruction in COPD (p=0.016).

CONCLUSION:

MMP-9 protein but not MMP activity was higher in sputum of COPD patients compared with controls. These results suggest that MMP-9 levels may not reflect the overall MMP activity in the airways of patients with COPD suggesting a complex relationship between MMP-9 protein and activity. Further studies of MMPs in COPD should comprise activity measures in addition to protein levels.

• Authors: Gillian E Lowrey, Neil Henderson, John D Blakey, Jonathan M Corne, Simon R Johnson
• Journal: Respiratory medicine (Respir Med) Vol. 102 Issue 6 Pg. 845-51 (Jun 2008) ISSN: 0954-6111 [Print] England
• PMID: 18328682 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• Tissue Inhibitor of Metalloproteinase-1
• Tissue Inhibitor of Metalloproteinase-2
• Pancreatic Elastase
• Collagenases
• Gelatinases
• Matrix Metalloproteinases
• Matrix Metalloproteinase 9

Topics

• Adult
• Aged
• Aged, 80 and over
• Biomarkers (metabolism)
• Bronchoalveolar Lavage Fluid (chemistry)
• Collagenases (metabolism)
• Female
• Forced Expiratory Volume
• Gelatinases (metabolism)
• Humans
• Male
• Matrix Metalloproteinase 9 (metabolism)
• Matrix Metalloproteinases (metabolism)
• Middle Aged
• Pancreatic Elastase (metabolism)
• Pulmonary Disease, Chronic Obstructive (enzymology, metabolism, physiopathology)
• Sputum (enzymology, metabolism)
• Tissue Inhibitor of Metalloproteinase-1 (metabolism)
• Tissue Inhibitor of Metalloproteinase-2 (metabolism)
• Vital Capacity