title: Construction of a cell model of β2-adrenoceptor downregulation.
abstract: OBJECTIVE
  To establish a cell model of β2-adrenergic receptor (β2AR) downregulation of murine airway smooth muscle induced by salbutamol to elucidate the molecular and biological mechanisms of β2AR downregulation.
  
  
  METHODS
  Airway smooth muscle cells (ASMCs) derived from Balb/c mice were primary cultured. Passage 2-5 cells were characterized by cell morphology and indirect immunofluorescence. More than 95% pure cells at passage 3 or 4 were randomly divided into two groups: control and salbutamol-treated groups. β2AR mRNA and protein expression levels were then detected by RT-PCR and western blot analyses.
  
  
  RESULTS
  Primary cultured cells demonstrated a typical "peak and valley"-like growth characteristic. Smooth muscle α-actin filaments paralleled the cell longitudinal axis in the cytoplasm. The origin of the ASMCs was validated and consistent with their morphology and biological characteristics. β2AR mRNA expression in the salbutamol-treated group was lower than that in the control group (P<0.05), and β2AR protein expression was also markedly lower than that in the control group (P<0.05).
  
  
  CONCLUSIONS
  We successfully established a cell model of β2AR downregulation in ASMCs, which may provide the foundation for further study of the mechanism of β2AR downregulation in asthmatic patients.
authors.affiliation: Department of Respiratory Medicine, Affiliated Hospital of Nantong University, Nantong 226001, P. R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Weishuai
authors.initials: W
authors.lastname: Zhang
authors.forename: Songshi
authors.initials: S
authors.lastname: Ni
keywords: Airway smooth muscle cells (ASMCs); cell culture; salbutamol; β2-adrenergic receptor (β2AR)