Abstract
Acute lung injury (ALI) is a major cause of morbidity and mortality in critically ill patients. Hyperoxia causes lung injury in animals and humans, and is an established model of ALI. Caveolin-1, a major constituent of caveolae, regulates numerous biological processes, including cell death and proliferation. Here we demonstrate that caveolin-1-null mice (cav-1-/-) were resistant to hyperoxia-induced death and lung injury. Cav-1-/- mice sustained reduced lung injury after hyperoxia as determined by protein levels in bronchoalveolar lavage fluid and histologic analysis. Furthermore, cav-1 -/- fibroblasts and endothelial cells and cav-1 knockdown epithelial cells resisted hyperoxia-induced cell death in vitro. Basal and inducible expression of the stress protein heme oxygenase-1 (HO-1) were markedly elevated in lung tissue or fibroblasts from cav-1-/- mice. Hyperoxia induced the physical interaction between cav-1 and HO-1 in fibroblasts assessed by co-immunoprecipitation studies, which resulted in attenuation of HO activity. Inhibition of HO activity with tin protoporphyrin-IX abolished the survival benefits of cav-1-/- cells and cav-1-/- mice exposed to hyperoxia. The cav-1-/- mice displayed elevated phospho-p38 mitogen-activated protein kinase (MAPK) and p38β expression in lung tissue/cells under basal conditions and during hyperoxia. Treatment with SB202190, an inhibitor of p38 MAPK, decreased hyperoxia-inducible HO-1 expression in wild-type and cav-1-/- fibroblasts. Taken together, our data demonstrated that cav-1 deletion protects against hyperoxia-induced lung injury, involving in part the modulation of the HO-1-cav-1 interaction, and the enhanced induction of HO-1 through a p38 MAPK-mediated pathway. These studies identify caveolin-1 as a novel component involved in hyperoxia-induced lung injury.
Original language | English (US) |
---|---|
Pages (from-to) | 171-179 |
Number of pages | 9 |
Journal | American Journal of Respiratory Cell and Molecular Biology |
Volume | 39 |
Issue number | 2 |
DOIs | |
State | Published - Aug 1 2008 |
Keywords
- Acute lung injury
- Acute respiratory distress syndrome
- Caveolin-1
- Heme oxygenase-1
ASJC Scopus subject areas
- Molecular Biology
- Pulmonary and Respiratory Medicine
- Clinical Biochemistry
- Cell Biology