Abstract
An air pollutant consists of any atmospheric substance that may harm humans, animals, vegetation or material. Various air pollutants have been reported, differing in their physicochemical characteristics. They can be grouped into four categories: gaseous pollutants (e.g. ozone, sulfur dioxide, oxides of nitrogen, carbon monoxide and volatile organic compounds), persistent organic pollutants, heavy metals (e.g. cadmium, lead and mercury) and particulate matter (coarse, fine and ultrafine). These pollutants can reach the respiratory system, eliciting pulmonary and/or systemic effects. These effects include inflammation, tissue remodelling and carcinogenesis: all phenomena where matrix metalloproteases (MMPs) play critical roles, given their broad effects on matrix remodelling and modulation of inflammation and cell signalling. Moreover, since expression and activity of MMPs can be induced by such stimuli, the hypothesis has been raised that MMPs could be involved in the health effects of pollutants. Until now, the implication of MMPs in these effects has been studied only for some pollutants and for a restricted selection of MMPs (mainly MMP-1, -2, -9 and -12), while evidence for a link between MMP induction/activation and health effects remains scarce. A larger number of studies is, therefore, needed in order to better understand the implication of MMPs in health effects associated with air pollution.
Footnotes
Previous articles in this series. No. 1: Löffek S, Schilling O, Franzke C-W. Biological role of matrix metalloproteinases: a critical balance. Eur Respir J 2011; 38: 191–208. No. 2: Elkington PT, Ugarte-Gil CA, Friedland JS. Matrix metalloproteinases in tuberculosis. Eur Respir J 2011; 38: 456–464. No. 3: Gaggar A, Hector A, Bratcher PE, et al. The role of matrix metalloproteinases in cystic fibrosis lung disease. Eur Respir J 2011; 38: 721–727. No. 4: Davey A, McAuley DF, O’Kane CM. Matrix metalloproteinases in acute lung injury: mediators of injury and drivers of repair. Eur Respir J 2011; 38: 959–970. No. 5: Vandenbroucke RE, Dejonckheere R, Libert C. A therapeutic role for matrix metalloproteinase inhibitors in lung diseases? Eur Respir J 2011; 38: 1200–1214. No. 6: Dancer RCA, Wood AM, Thickett DR. Metalloproteinases in idiopathic pulmonary fibrosis. Eur Respir J 2011; 38: 1461–1467. No. 7: Churg A, Zhou S, Wright JL. Matrix metalloproteinases in COPD. Eur Respir J 2012; 39: 197–209.
Support Statement
M. Dagouassat was supported by a grant from DIM SENT (Région Ile-de-France) and by the CARESEN foundation, J. Boczkowski by INSERM and Assistance Publique-Hôpitaux de Paris (Contrat Hospitalier de Recherche Translationnelle), and S. Lanone by INSERM and Centre Hospitalier Intercommunal de Créteil (Contrat Hospitalier de Recherche Translationnelle) (all France).
Statement of Interest
None declared.
- Received November 10, 2011.
- Accepted December 11, 2011.
- ©ERS 2012