title: Cholesterol depletion and genistein as tools to promote F508delCFTR retention at the plasma membrane.
abstract: OBJECTIVE
  F508delCFTR-, but not wtCFTR-, expressing fibroblasts resemble Niemann Pick type C cells in the massive intracellular accumulation of free cholesterol. The recruitment and activation of F508delCFTR by cholesterol depletion was studied.
  
  
  METHODS
  Filipin staining, forskolin-stimulated anion efflux and FITC-dextran uptake were studied in control cells and fibroblasts treated with 2-hydroxypropyl beta-cyclodextrin phosphatidylcholine large unilamellar vesicles to deplete cellular free cholesterol.
  
  
  RESULTS
  Treatment of F508delCFTR-, but not wtCFTR-, expressing fibroblasts with 2-hydroxypropyl beta-cyclodextrin resulted in a reduction in cellular cholesterol and a potentiation of the forskolin-induced anion efflux. In addition, forskolin also promoted a massive increase in the rate of endocytosis in F508delCFTR fibroblasts, which was absent in genistein- or cyclodextrin-treated cultures.
  
  
  CONCLUSIONS
  The results not only suggest that reducing cellular cholesterol may serve as pharmacotherapeutic tool in the treatment of cystic fibrosis but also reveal a novel mechanism for genistein regulation of F508delCFTR, i.e. retention by inhibition of endocytosis.
authors.affiliation: Department of Biochemistry, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Christina H
authors.initials: CH
authors.lastname: Lim
authors.forename: Marcel J
authors.initials: MJ
authors.lastname: Bijvelds
authors.forename: Alex
authors.initials: A
authors.lastname: Nigg
authors.forename: Kees
authors.initials: K
authors.lastname: Schoonderwoerd
authors.forename: Adriaan B
authors.initials: AB
authors.lastname: Houtsmuller
authors.forename: Hugo R
authors.initials: HR
authors.lastname: de Jonge
authors.forename: Ben C
authors.initials: BC
authors.lastname: Tilly
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D010649:Phenylalanine / Q000235:genetics / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000494:pharmacology
chemical_list: D010713:Phosphatidylcholines; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005576:Colforsin; D010649:Phenylalanine; D002784:Cholesterol; D019833:Genistein