title: Chronic cholesterol depletion by lovastatin suppresses MUC5AC gene expression in human airway epithelial cells.
abstract: BACKGROUND
  We recently showed that acute cholesterol depletion in the plasma membrane of NCI-H292 cells by methyl-β-cyclodextrin suppressed IL-1beta-induced MUC5AC gene expression. Because cholesterol depletion is clinically used as an antihypersecretory method, chronic cholesterol depletion by lovastatin is more rational and safe than acute depletion. Therefore, we sought to investigate whether chronic cholesterol depletion by lovastatin is feasible and, if so, suppresses the expression of GMUC5AC in NCI-H292 cells. We also considered whether this alteration of MUC5AC expression is related to IL-1 receptor and mitogen-activated protein kinase (MAPK) activity.
  
  
  METHODS
  After NCI-H292 cells were pretreated with 10 μM of lovastatin for 1 hour, 10 ng/mL of IL-1β was added and cotreated with lovastatin for 24 hours. MUC5AC mRNA expression was then determined by real-time polymerase chain reaction. Cholesterol depletion by lovastatin was measured by modified microenzymatic fluorescence assay and filipin staining. The phosphorylation of IL-1 receptor, ERK, and p38 MAPK was analyzed by Western blot.
  
  
  RESULTS
  Cholesterol in the plasma membrane was significantly depleted by lovastatin treatment for 24 hours. IL-1beta0-induced MUC5AC mRNA expression was decreased by lovastatin and this decrease occurred IL-1 receptor specifically. Lovastatin suppressed the activation of p38 MAPK but not ERK1/2 in cells activated with IL-1beta. This result suggests that lovastatin-mediated suppression of IL-1beta-induced MUC5AC mRNA operated only viathe p38 MAPK-dependent pathway.
  
  
  CONCLUSIONS
  Chronic cholesterol depletion in the plasma membrane of NCI-H292 cells may be considered an antihypersecretory method, because it effectively inhibits mucin gene expression of human airway epithelial cells.
authors: Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.
authors: Eun Jung
authors: EJ
authors: Lee
authors: Kee Jae
authors: KJ
authors: Song
authors: Jin Ho
authors: JH
authors: Kwon
authors: Ah Young
authors: AY
authors: Park
authors: Kwang-Hee
authors: KH
authors: Jo
authors: Kyung-Su
authors: KS
authors: Kim
mesh_terms: D000924:Anticholesteremic Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D015536:Down-Regulation; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D053583:Interleukin-1beta / Q000276:immunology; D008148:Lovastatin / Q000494:pharmacology*; D020935:MAP Kinase Signaling System; D055271:Mucin 5AC / Q000235:genetics / Q000378:metabolism*; D017472:Receptors, Interleukin-1 / Q000378:metabolism; D012137:Respiratory System / Q000166:cytology; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: D000924:Anticholesteremic Agents; D053583:Interleukin-1beta; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D017472:Receptors, Interleukin-1; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol; D008148:Lovastatin