Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Chronic obstructive pulmonary disease (COPD) is a common lung disease with cigarette smoking as the major etiological factor, but only 15% of smokers develop COPD. Destruction of lung elastin observed in COPD is mediated by many enzymes, including cysteine, serine, and matrix metalloproteinases (MMP). The contribution of these enzymes to the lung elastolytic load, released from alveolar macrophages collected from nonsmokers, healthy smokers, and COPD patients, was examined by radiolabeled elastin as substrate in the presence of specific enzyme inhibitors. The activity of MMP was further examined by zymography and Western blotting. COPD macrophages degraded more elastin than either of the other groups. Elastolysis was greatest in the initial 24 h. Through the 72-h culture period, the contribution to elastolysis of serine elastases decreased, MMP increased, and cysteine elastases remained constant. The increased release of elastolytic enzymes in COPD subjects may explain why some smokers develop COPD. This difference may be due to unknown susceptibility factors. Serine proteases play a significant role; however, other enzymes, particularly the MMP, deserve further investigation.

Original publication

DOI

10.1152/ajplung.00020.2002

Type

Journal article

Journal

Am J Physiol Lung Cell Mol Physiol

Publication Date

10/2002

Volume

283

Pages

L867 - L873

Keywords

Aged, Cysteine Endopeptidases, Cysteine Proteinase Inhibitors, Elasticity, Female, Humans, Leucine, Macrophages, Alveolar, Male, Matrix Metalloproteinase 12, Matrix Metalloproteinase 2, Matrix Metalloproteinase 9, Metalloendopeptidases, Middle Aged, Pulmonary Disease, Chronic Obstructive, Serine Endopeptidases, Serine Proteinase Inhibitors, Smoking