Author(s)

Yuriko Hirono, Yasuyuki Tanahashi, Kazuma Sasaki, Kenjiro Konno, Yuki Shirai, Kengo Kobayashi, Azusa Someya, Sumire Inaga, Masaaki Sakura, Kent E. Pinkerton, Minoru Takeuchi

Center for Health and the Environment, University of California Davis, Davis, USA.
Department of Animal Medical Science, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.
Division of Genome Morphology, Department of Functional, Morphological and Regulatory Science, Faculty of Medicine, Tottori University, Yonago, Japan.

Alveolar macrophages (AM) are known to play an essential role in lung defense through their ability to remove the foreign matters reaching the lung alveoli. Cigarette smoke (CS) is a critical risk factor for many lung diseases. CS is inhaled into the lung by respiretion and affects AM. It has been previously reported that CS induces inhibition of cytokine production, cell surface receptor expression and antigen presentation in AM. However, the relationship of immune suppression and DNA damage caused by CS in AM is still unclear. Therefore, in this study, we investigated AM immune function and DNA damage in CS-exposed mice. Mice were exposed to CS of 20 cigarettes/day during 10 days using a HambrugⅡsmoking machine. After exposure, AM were obtained by bronchoalveolar lavage. The number of AM was significantly increased in CS-exposed mice compared with non-CS-exposed mice. Phagocytic activity of AM was significantly inhibited by CS exposure. Percentage of CD11b-, CD14-, Toll-like receptor (TLR)2- or TLR4-positive cells was significantly decreased in CS-exposed mice compared with non-CS-exposed mice. Interleukin-1β mRNA expression in lipopolysaccharide-stimulated AM was significantly inhibited by CS exposure. Intracellular reactive oxygen species (ROS) (, H₂O₂) production of AM was significantly increased, and DNA damage was induced by CS exposure. These results suggest that impaired immune functions by CS exposure may be related to DNA damage via excessive ROS induced by CS. These alterations of AM caused by CS could be associated with infection and development of pulmonary diseases.

Alveolar Macrophages; Phagocytic Activity; ROS Production; DNA Damage; Cigarette Smoke

Hirono, Y. , Tanahashi, Y. , Sasaki, K. , Konno, K. , Shirai, Y. , Kobayashi, K. , Someya, A. , Inaga, S. , Sakura, M. , Pinkerton, K. and Takeuchi, M. (2013) Alveolar macrophage functions and DNA damage in cigarette smoke-exposed mice. Advances in Bioscience and Biotechnology, 4, 1-7. doi: 10.4236/abb.2013.48A3001.