Altered expression of antimicrobial molecules in cigarette smoke-exposed emphysematous mice lungs

Respirology. 2008 Nov;13(7):1061-5. doi: 10.1111/j.1440-1843.2008.01362.x. Epub 2008 Aug 10.


Background and objective: The natural history of COPD, a disease usually caused by cigarette smoking, is associated with frequent respiratory infections. Consistent with human COPD, bacterial clearance in the lungs has been reported to be impaired in mice exposed to cigarette smoke. In the airways, several antimicrobial molecules such as surfactant proteins (SP), beta-defensins (BD), secretory leucocyte protease inhibitor (SLPI) and lysozyme play important roles in the defence against invading pathogens. This study evaluated the expression of antimicrobial molecules in mice lungs with cigarette smoke-induced emphysematous changes.

Methods: Six B6C3F1 mice were exposed to cigarette smoke (2 cigarettes/day/mouse for 6 months) or room air. Gene expression within the lungs of mice in both groups was assessed by RT-PCR.

Results: The expression of SP-A, BD2, BD3 and SLPI was significantly elevated in the lungs of cigarette smoke-exposed mice compared with air-exposed mice. BD1 expression decreased in the smoke-exposed mice and lysozyme expression was unchanged.

Conclusions: Chronic cigarette smoke exposure did not suppress the expression of antimicrobial molecules in the lung. Altered expression of antimicrobial molecules in this mouse model does not explain the impaired host defence against respiratory microbes seen in patients with COPD.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents
  • Disease Models, Animal
  • Gene Expression*
  • Lung / metabolism
  • Lung / pathology
  • Male
  • Mice
  • Pulmonary Emphysema / etiology
  • Pulmonary Emphysema / genetics*
  • Pulmonary Emphysema / metabolism
  • Pulmonary Surfactant-Associated Protein A / biosynthesis
  • Pulmonary Surfactant-Associated Protein A / genetics*
  • RNA / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Secretory Leukocyte Peptidase Inhibitor / biosynthesis
  • Secretory Leukocyte Peptidase Inhibitor / genetics*
  • Smoking / adverse effects*
  • beta-Defensins / biosynthesis
  • beta-Defensins / genetics*


  • Anti-Bacterial Agents
  • Defb1 protein, mouse
  • Defb2 protein, mouse
  • Pulmonary Surfactant-Associated Protein A
  • Secretory Leukocyte Peptidase Inhibitor
  • Slpi protein, mouse
  • beta-Defensins
  • RNA