title: Expression of smooth muscle and extracellular matrix proteins in relation to airway function in asthma.
abstract: BACKGROUND
  Smooth muscle content is increased within the airway wall in patients with asthma and is likely to play a role in airway hyperresponsiveness. However, smooth muscle cells express several contractile and structural proteins, and each of these proteins may influence airway function distinctly.
  
  
  OBJECTIVE
  We examined the expression of contractile and structural proteins of smooth muscle cells, as well as extracellular matrix proteins, in bronchial biopsies of patients with asthma, and related these to lung function, airway hyperresponsiveness, and responses to deep inspiration.
  
  
  METHODS
  Thirteen patients with asthma (mild persistent, atopic, nonsmoking) participated in this cross-sectional study. FEV(1)% predicted, PC(20) methacholine, and resistance of the respiratory system by the forced oscillation technique during tidal breathing and deep breath were measured. Within 1 week, a bronchoscopy was performed to obtain 6 bronchial biopsies that were immunohistochemically stained for alpha-SM-actin, desmin, myosin light chain kinase (MLCK), myosin, calponin, vimentin, elastin, type III collagen, and fibronectin. The level of expression was determined by automated densitometry.
  
  
  RESULTS
  PC(20) methacholine was inversely related to the expression of alpha-smooth muscle actin (r = -0.62), desmin (r = -0.56), and elastin (r = -0.78). In addition, FEV(1)% predicted was positively related and deep inspiration-induced bronchodilation inversely related to desmin (r = -0.60), MLCK (r = -0.60), and calponin (r = -0.54) expression.
  
  
  CONCLUSIONS
  Airway hyperresponsiveness, FEV(1)% predicted, and airway responses to deep inspiration are associated with selective expression of airway smooth muscle proteins and components of the extracellular matrix.
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands. A.M.Slats@LUMC.nl
authors.forename: Annelies M
authors.initials: AM
authors.lastname: Slats
authors.forename: Kirsten
authors.initials: K
authors.lastname: Janssen
authors.forename: Annemarie
authors.initials: A
authors.lastname: van Schadewijk
authors.forename: Dirk T
authors.initials: DT
authors.lastname: van der Plas
authors.forename: Robert
authors.initials: R
authors.lastname: Schot
authors.forename: Joost G
authors.initials: JG
authors.lastname: van den Aardweg
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.forename: Pieter S
authors.initials: PS
authors.lastname: Hiemstra
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Rabe
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sterk
mesh_terms: D001249:Asthma / Q000378:metabolism* / Q000503:physiopathology; D001980:Bronchi / Q000378:metabolism / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000378:metabolism / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D001999:Bronchoscopy; D003430:Cross-Sectional Studies; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D009124:Muscle Proteins / Q000096:biosynthesis*; D009130:Muscle, Smooth / Q000737:chemistry / Q000378:metabolism; D012129:Respiratory Function Tests
chemical_list: D016326:Extracellular Matrix Proteins; D009124:Muscle Proteins