title: Peripheral blood and airway tissue expression of transforming growth factor beta by neutrophils in asthmatic subjects and normal control subjects.
abstract: BACKGROUND
  Airway remodeling may play an important role in asthma pathophysiology. Transforming growth factor beta (TGF-beta) has a critical role in the remodeling process. Although cellular sources for TGF-beta have been previously investigated in asthma airways, the expression, release, or both of TGF-beta from asthmatic airways and blood neutrophils has not been reported.
  
  
  OBJECTIVE
  The current study evaluated the TGF-beta protein and messenger (m)RNA expression by airway and peripheral blood neutrophils in asthmatic and normal subjects.
  
  
  METHODS
  TGF-beta protein expression by airway and peripheral blood neutrophils was detected by using immunocytochemistry. TGF-beta protein levels in blood neutrophil supernatant were measured by using an enzyme immunoassay. TGF-beta mRNA expression was evaluated by using reverse transcription-PCR.
  
  
  RESULTS
  Higher numbers of TGF-beta(+) cells and neutrophils were found in airway tissue of asthmatic (n = 15) compared with normal subjects (n = 10). Although neutrophils in both asthmatic and normal airway tissue expressed TGF-beta protein and the percentage of neutrophils expressing TGF-beta was similar between the two groups, the total number of TGF-beta(+) neutrophils was higher in the asthmatic subjects (P =.01). Peripheral blood neutrophils from asthmatic (n = 5) and normal subjects (n = 7) also expressed TGF-beta protein and mRNA. Blood neutrophils from asthmatic subjects spontaneously released significantly higher levels of TGF-beta than those from normal subjects (P =.007).
  
  
  CONCLUSIONS
  These data suggest that airway and blood neutrophils from both asthmatic and normal subjects can express and release TGF-beta. Higher levels of TGF-beta expression-release from asthmatic neutrophils indicate that neutrophils may be involved in the airway remodeling process of asthmatic subjects.
authors: Department of Medicine, National Jewish Medical and Research Center, Denver, CO 80206, USA.
authors: H W
authors: HW
authors: Chu
authors: J B
authors: JB
authors: Trudeau
authors: S
authors: S
authors: Balzar
authors: S E
authors: SE
authors: Wenzel
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001706:Biopsy; D001980:Bronchi / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D009504:Neutrophils / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000097:blood; D012333:RNA, Messenger / Q000378:metabolism; D012137:Respiratory System / Q000166:cytology*; D016212:Transforming Growth Factor beta / Q000097:blood* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D010196:Pancreatic Elastase