Fibrotic response of tissue remodeling in COPD.

Lung tissue remodeling in chronic obstructive pulmonary disease (COPD) involves diverse processes characterized by epithelial disruption, smooth muscle hypertrophy/hyperplasia, airway wall fibrosis, and alveolar destruction. According to the accepted current theory of COPD pathogenesis, tissue remodeling in COPD is predominantly a consequence of an imbalance between proteolytic and antiproteolytic activities. However, most of the studies carried out during the last few years have focused on mechanisms related to degradation of extracellular matrix (ECM) structural proteins, neglecting those involved in ECM protein deposition. This review revisits some of the latest findings related to fibrotic changes that occur in the airway wall of COPD patients, as well as the main cellular phenotypes relevant to these processes.