title: Expression and functional activity of P-glycoprotein in passaged primary human nasal epithelial cell monolayers cultured by the air-liquid interface method for nasal drug transport study.
abstract: OBJECTIVE
  P-glycoprotein (P-gp) is an efflux transporter encoded by the multidrug resistance gene (MDR1), which is also known as the human ABCB1 gene (ATP-binding cassette, subfamily-B). The objectives of this study were to investigate the expression of P-gp in passaged primary human nasal epithelial (HNE) cell monolayer, cultured by the air-liquid interface (ALI) method, and to evaluate its feasibility as an in-vitro model for cellular uptake and transport studies of P-gp substrates.
  
  
  METHODS
  Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to verify the expression of the MDR1 gene. Transport and cellular uptake studies with P-gp substrate (rhodamine123) and P-gp inhibitors (verapamil and cyclosporin A) were conducted to assess the functional activity of P-gp in HNE cell monolayers cultured by the ALI method.
  
  
  RESULTS
  MDR1 gene expression in primary HNE cell monolayers cultured by ALI method was confirmed by RT-PCR. The apparent permeability coefficient (P(app) ) of the P-gp substrate (rhodamine123) in the basolateral to apical (B to A) direction was 6.9 times higher than that in the apical to basolateral (A to B) direction. B to A transport was saturated at high rhodamine123 concentration, and the treatment of P-gp inhibitors increased cellular uptake of rhodamine123 in a time- and concentration-dependent manner.
  
  
  CONCLUSIONS
  These results support the MDR1 gene expression and the functional activity of P-gp in primary HNE cell monolayers cultured by the ALI method.
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea.
authors.forename: Hyun-Jong
authors.initials: HJ
authors.lastname: Cho
authors.forename: Min-Koo
authors.initials: MK
authors.lastname: Choi
authors.forename: Hongxia
authors.initials: H
authors.lastname: Lin
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Suk-Jae
authors.initials: SJ
authors.lastname: Chung
authors.forename: Chang-Koo
authors.initials: CK
authors.lastname: Shim
authors.forename: Dae-Duk
authors.initials: DD
authors.lastname: Kim
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004333:Drug Administration Routes; D005456:Fluorescent Dyes / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D009297:Nasal Mucosa / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020112:Rhodamine 123 / Q000378:metabolism
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D020112:Rhodamine 123