title: Evaluation of cigarette smoke-induced emphysema in mice using quantitative micro-computed tomography.
abstract: Chronic cigarette smoke (CS) exposure provokes variable changes in the lungs, and emphysema is an important feature of chronic obstructive pulmonary disease. The usefulness of micro-computed tomography (CT) to assess emphysema in different mouse models has been investigated, but few studies evaluated the dynamic structural changes in a CS-induced emphysema mouse model. A novel micro-CT technique with respiratory and cardiac gating has resulted in high-quality images that enable processing for further quantitative and qualitative analyses. Adult female C57BL/6J mice were repeatedly exposed to mainstream CS, and micro-CT scans were performed at 0, 4, 12, and 20 wk. Emphysema was also histologically quantified at each time point. Air-exposed mice and mice treated with intratracheal elastase served as controls and comparisons, respectively. End-expiratory lung volume, corresponding to functional residual volume, was defined as the calculated volume at the phase of end-expiration, and it evaluated air trapping. The end-expiratory lung volumes of CS-exposed mice were significantly larger than those of air controls at 12 and 20 wk, which was in line with alveolar enlargement and destruction by histological quantification. However, CS exposure neither increased low attenuation volume nor decreased the average lung CT value at any time point, unlike the elastase-instilled emphysema model. CS-exposed mice had rather higher average lung CT values at 4 and 12 wk. This is the first study characterizing a CS-induced emphysema model on micro-CT over time in mice. Moreover, these findings extend our understanding of the distinct pathophysiology of CS-induced emphysema in mice.
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Chubachi
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Naofumi
authors.initials: N
authors.lastname: Kameyama
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Sato
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Mizuha
authors.initials: M
authors.lastname: Haraguchi
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Saeko
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan tbetsuyaku@z5.keio.jp.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Betsuyaku
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D051379:Mice; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012907:Smoking / Q000009:adverse effects*; D055114:X-Ray Microtomography
keywords: chronic obstructive pulmonary disease; mouse