Role of MMPs and Oxidants in Lung Diseases

The lung matrix consists of numerous extracellular matrix (ECM) proteins and glycoproteins including collagens, elastin, fibronectin, laminin, heparin, and sulfated proteoglycans. Matrix metalloproteinases (MMPs) play a pivotal role in the remodeling of ECM and is central in lung organogenesis. Although not all MMPs are found in the lung matrix, there is considerable evidence that few MMPs are up- and/or downregulated during acute and chronic diseases of the lungs. The association of alveolar ECM is related in chronic inflammatory lung diseases like idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis (CF) which have been investigated extensively. IPF is associated with production, deposition, and remodeling of the ECM, whereas COPD is characterized by a loss of the same. MMPs target the structural ECM proteins, cell adhesion molecules, growth factors, cytokines, and chemokines that play role in the genesis and development of chronic lung diseases. The association between MMPs and lung cancer has been long documented although the precise role of MMPs in lung cancer remains unanswered. Herein, we have discussed the role of MMPs along with oxidants in the pathogenesis of chronic lung diseases, cancer, and their potential as targets for therapy.