title: Transport of HIV-protease inhibitors across 1 alpha,25di-hydroxy vitamin D3-treated Calu-3 cell monolayers: modulation of P-glycoprotein activity.
abstract: OBJECTIVE
  The presence of P-glycoprotein (P-gp) within the lipid bi-layers of the absorptive cells greatly influences drug entry into the HIV-infected sanctuary sites. The objective of this study was to acces the potential role of pulmonary cells expressing high levels of P-gp in the efflux of potent anti-HIV drugs such as protease inhibitors.
  
  
  METHODS
  Human airway epithelium-derived Calu-3 cells grown in the presence of 0.025 mM 1alpha,25di-hydroxy Vitamin D3 (di-OH vit D3) were used as a model to evaluate the effects of p-glycoprotein efflux of HIV protease inhibitors. Cells used as controls were not treated with di-OH vit D3. The anti-HIV agents 3H Ritonavir and Saquinavir (50 microM) were used as model compounds for influx and efflux studies
  
  
  RESULTS
  Di-OH vit D3 treatment enhanced the differentiation c Calu-3 cells indicated by more cilia and mucus secretion. It also caused elevated P-gp expression as demonstrated by Western Bla analysis and enhanced basal to apical transport of cyclosporine as compared with untreated cells. The amount of Saquinavir transported, after 3 h, across untreated Calu-3 cells (A-B) was 3-fold higher (1.62 microg; Papp = 2A (+/- 0.79) x 10(-6) cm/s) than di-OH vi D3-treated cells (0.57 microg with the Papp = 5.02 (+/- 0.62) x 10(-7) cm/s) Similar transport profiles were obtained for 3H ritonavir and a significant increase (p < 0.05) in the A-B transport (2.5-fold) of 3H ritonavir was observed when the cell monolayers were preincubated with testosterone prior to transport studies. However, transport of AZT remained unaltered in di-OH vit D3 treated monolayers.
  
  
  CONCLUSIONS
  Modulation of P-gp activity may be necessary to increase the therapeutic efficacy of protease inhibitors against HIV-1 reservoirs across alveolar lining cells and fluids.
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri, 5005 Rockhill Road, Kansas City, Misouri 64110-2499, USA.
authors.forename: Jignesh
authors.initials: J
authors.lastname: Patel
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Pal
authors.forename: Veena
authors.initials: V
authors.lastname: Vangal
authors.forename: Mohit
authors.initials: M
authors.lastname: Gandhi
authors.forename: Ashim L
authors.initials: AL
authors.lastname: Mitra
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D017320:HIV Protease Inhibitors / Q000493:pharmacokinetics*; D006801:Humans; D014407:Tumor Cells, Cultured; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D017320:HIV Protease Inhibitors; C118756:dihydroxy-vitamin D3; D014807:Vitamin D; D003577:Cytochrome P-450 Enzyme System; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A