title: Proteomic analysis in lung tissue of smokers and COPD patients.
abstract: BACKGROUND
  Although cigarette smoking is the most important risk factor for COPD, COPD develops in only a minority of smokers, suggesting a significant genetic role. To solve the underlying pathophysiologic mechanism, it is critical to understand genes and their final product, ie, proteins. We investigated the exclusive proteins from the lung tissues obtained from COPD patients using proteomics.
  
  
  METHODS
  Nontumorous lung tissue specimens were obtained from patients who underwent surgery for lung cancer. We included 22 subjects: nonsmokers (n = 8), smokers without COPD (healthy smokers, n = 7), and smokers with COPD (n = 7). Proteins were separated from their spots with two-dimensional polyacrylamide gel electrophoresis and examined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). To validate the proteins from the above procedures, Western blotting and immunohistochemistry were conducted.
  
  
  RESULTS
  Twelve protein spots from COPD group significantly increased or decreased compared with the other two groups were chosen for MALDI-TOF-MS analysis. Eight proteins were up-regulated in the COPD group as compared with the nonsmokers. Meanwhile, five proteins from the COPD group were up-regulated and five were down-regulated when compared with healthy smokers. Of these, matrix metalloproteinase (MMP)-13 and thioredoxin-like 2 were significantly increased in the COPD patients by Western blot and immunohistochemistry. MMP-13 was mainly expressed in the alveolar macrophages and type II pneumocytes; however, thioredoxin-like 2 was primarily seen in the bronchial epithelium.
  
  
  CONCLUSIONS
  MMP-13 and thioredoxin-like 2 in lungs increased in patients with COPD. MMP-13 was mainly expressed in the alveolar macrophages and type II pneumocytes. In contrast, thioredoxin-like 2 was primarily seen in the bronchial epithelium.
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul. Electronic address: khin@kumc.or.kr.
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: In
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Ansan.
authors.forename: Je Hyeong
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: Sang Yeub
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Ansan.
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: Jae Jeong
authors.initials: JJ
authors.lastname: Shim
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Kang
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: Se Hwa
authors.initials: SH
authors.lastname: Yoo
authors.affiliation: Department of Pathology, Korea University College of Medicine, Seoul.
authors.forename: Chul Hwan
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Korea University College of Medicine, Seoul.
authors.forename: Han-Kyeom
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Korea University College of Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Anatomy, Korea University College of Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Chang Sub
authors.initials: CS
authors.lastname: Uhm