Increased expression of transforming growth factor-beta 1 in small airway epithelium from tobacco smokers and patients with chronic obstructive pulmonary disease (COPD)

Citation
H. Takizawa et al., Increased expression of transforming growth factor-beta 1 in small airway epithelium from tobacco smokers and patients with chronic obstructive pulmonary disease (COPD), AM J R CRIT, 163(6), 2001, pp. 1476-1483
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems","da verificare
Journal title
AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE
ISSN journal
1073-449X → ACNP
Volume
163
Issue
6
Year of publication
2001
Pages
1476 - 1483
Database
ISI
SICI code
1073-449X(200105)163:6<1476:IEOTGF>2.0.ZU;2-G
Abstract
Tobacco smoke is believed to cause small airway disease and then chronic ob structive pulmonary disease (COPD), but the molecular mechanisms by which s mall airway obstruction occurs remain unknown. To study the gene expression levels of transforming growth factor (TGF)-beta1, a potent fibrogenic fact or, in small airway epithelium from smokers and patients with COPD, we harv ested highly pure samples of epithelial cells from small airways under dire ct vision by using an ultrathin bronchofiberscope BF-2.7T (outer diameter 2 .7 mm with a biopsy channel of 0.8 mm in diameter). The expression levels o f TGF-beta1 were evaluated by reverse transcription-polymerase chain reacti on (RT-PCR). The mRNA levels of TGF-beta1 corrected by beta -actin transcri pts were significantly higher in the smoking group and patients with COPD t han those in nonsmokers (p < 0.01). Furthermore, among smokers and patients with COPD, TGF-<beta>1 mRNA levels correlated positively with the extent o f smoking history (pack-years) and the degree of small airway obstruction a s assessed by measurements of flow-volume curves. Immunocytochemistry of th e cells demonstrated more intense stainings for TGF-beta1 in samples from s mokers and patients with COPD than from nonsmokers. Spontaneously released immunoreactive TGF-beta1 levels from cultured epithelial cells were more el evated in subjects with a history of smoking and patients with COPD than in nonsmokers. Our study showed a close link between smoking and expression o f TGF-beta1 in small airways. Our results also suggested that small airway epithelial cells might be involved in obstructive changes found in smokers and patients with COPD.