title: Vessel-associated transforming growth factor-beta1 (TGF-β1) is increased in the bronchial reticular basement membrane in COPD and normal smokers.
abstract: BACKGROUND
  Transforming growth factor-beta1 (TGF-β1) is a multipotential cytokine with angiogenic activity. There are only limited data about its role in airway remodeling in COPD. We have previously shown that the reticular basement membrane (Rbm) is hypervascular in the airways of current smokers either with or without chronic obstructive pulmonary disease (COPD). This study evaluated TGF-β1 immunostaining in the Rbm and its relationship to vascularity in smokers with or without COPD.
  
  
  RESULTS
  Bronchial biopsies from 15 smokers with normal lung function, 19 current and 14 ex-smokers with COPD were immunostained for TGF-β1 antibody and compared to 17 healthy controls. The percentage area of tissue and also number and area of vessels staining positively for TGF-β1 were measured and compared between groups. Some bronchial biopsies from current smoking COPD subjects were also stained for phosphorylated (active) Smad2/3. Epithelial TGF- β1 staining was not different between COPD current smokers and normal controls. TGF-β1 stained vessels in the Rbm were increased in smokers with normal lung function, current smoking COPD and ex-smokers with COPD compared to controls [median (range) for number of vessels/mm Rbm 2.5 (0.0-12.7), 3.4 (0.0-8.1) and 1.0 (0.0-6.3) vs. 0.0 (0.0-7.0), p<0.05]. Percentage of vessels stained was also increased in these clinical groups. Preliminary data suggest that in current smoking COPD subjects endothelial cells and cells in the Rbm stain positively for phosphorylated Smad2/3 suggesting TGF-β1 is functionally active in this situation.
  
  
  CONCLUSIONS
  Vessel-associated TGF-β1 activity is increased in the bronchial Rbm in smokers and especially those with COPD.
authors: NHMRC National Centre of Research Excellence for Chronic Respiratory Disease, School of Medicine, University of Tasmania, Hobart, Australia.
authors: Amir
authors: A
authors: Soltani
authors: Sukhwinder Singh
authors: SS
authors: Sohal
authors: David
authors: D
authors: Reid
authors: Steve
authors: S
authors: Weston
authors: Richard
authors: R
authors: Wood-Baker
authors: E Haydn
authors: EH
authors: Walters
mesh_terms: D000328:Adult; D000368:Aged; D001485:Basement Membrane / Q000378:metabolism / Q000473:pathology*; D001706:Biopsy; D001808:Blood Vessels / Q000378:metabolism* / Q000473:pathology; D001980:Bronchi / Q000378:metabolism / Q000473:pathology*; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010766:Phosphorylation; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism / Q000473:pathology*; D051785:Smad Proteins / Q000378:metabolism; D012907:Smoking / Q000378:metabolism / Q000473:pathology*; D013194:Staining and Labeling; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D051785:Smad Proteins; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1