Prevention of lung injury by Muc1 mucin in a mouse model of repetitive Pseudomonas aeruginosa infection
Objective and design
To determine whether repetitive airway Pseudomonas aeruginosa (Pa) infection results in lung inflammation and injury and, if so, whether these responses are affected by Muc1 mucin. Muc1 wild type (WT) and knockout (KO) mice were compared for body weights, lung inflammatory responses, and airspace enlargement using a chronic lung infection model system.
Mice were treated intranasally with Pa (107 CFU) on days 0, 4, 7 and 10. On day 14, body weights, inflammatory cell numbers in bronchoalveolar lavage fluid (BALF), and airspace enlargement were measured. Differences in inflammatory responses between groups were statistically analyzed by the Student’s t test and ANOVA.
Muc1 WT mice exhibited mild degrees of both inflammation and airspace enlargement following repetitive airway Pa infection. However, Muc1 KO mice exhibited significantly decreased body weights, greater macrophage numbers in the BALF, and increased airspace enlargement compared with Muc1 WT mice.
This is the first report demonstrating that Muc1 deficiency can lead to lung injury during chronic Pa infection in mice. These results suggest that MUC1 may play a crucial role in the resolution of inflammation during chronic respiratory infections and that MUC1 dysfunction likely contributes to the pathogenesis of chronic inflammatory respiratory disease.
KeywordsRespiratory MUC1 mucin Pseudomonas aeruginosa Inflammation Airspace enlargement
- 1.Levison ME, Kaye D. Pneumonia caused by gram-negative bacilli: an overview. Rev Infect Dis 1985;7 Suppl 4:S656–65.Google Scholar
- 43.Barnes PJ. Medicine. Neutrophils find smoke attractive. Science. 2010;330(6000):40–1.Google Scholar
- 47.da Hora K, Valenca SS, Porto LC. Immunohistochemical study of tumor necrosis factor-alpha, matrix metalloproteinase-12, and tissue inhibitor of metalloproteinase-2 on alveolar macrophages of BALB/c mice exposed to short-term cigarette smoke. Exp Lung Res. 2005;31(8):759–70.PubMedCrossRefGoogle Scholar