Ozone stress down-regulates the expression of cystic fibrosis transmembrane conductance regulator in human bronchial epithelial cells.
To investigate abnormalities of cystic fibrosis transmembrane conductance regulator (CFTR) expression in chronic inflammatory airway diseases and its regulation mechanisms, the present study was designed to observe the expression of CFTR, CFTR chloride current and the possible relevant signal pathways in in vitro and in vivo bronchial epithelium by using real-time PCR, immunofluorescence, Western blot and whole cell patch-clamp. The results demonstrated that CFTR staining was decreased in rat airway epithelium under ozone stress. Ozone stress also down-regulated CFTR protein and mRNA expression and CFTR chloride current in cultured human bronchial epithelial cells (HBEC). STAT1 signal pathway was checked to investigate the signal mechanism. It was found that pretreatment with STAT1 inhibitor attenuated the down-regulated CFTR expression induced by ozone stress. We also observed that ozone stress accelerated the phosphorylation of STAT1 in HBEC, which could be influenced by some signaling molecules related to the early transduction of cellular stress. Furthermore, reactive oxygen species inhibitors N-acetylcysteine and nitric oxide synthase inhibitor aminoguanidine increased the expression of CFTR. Ozone stress could down-regulate the expression of CFTR and decrease CFTR chloride current in HBEC. The signal mechanism which referred to cascade events in cells included early oxidative stress signal transmission molecules, and subsequently transcription modulator STAT1.
Qu
Fei
F
Department of Physiology, Central South University Xiangya Medical School, Changsha, Hunan 410078, China.
Qin
Xiao-Qun
XQ
Cui
Yan-Ru
YR
Xiang
Yang
Y
Tan
Yu-Rong
YR
Liu
Hui-Jun
HJ
Peng
Li-Hua
LH
Zhou
Xiao-Yan
XY
Liu
Chi
C
Zhu
Xiao-Lin
XL
D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology*; D002478:Cells, Cultured; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000096:biosynthesis* / Q000235:genetics*; D015536:Down-Regulation / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects; D010126:Ozone / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020032:Tyrphostins / Q000494:pharmacology
D012333:RNA, Messenger; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D010126:Ozone