title: Delivery of peptide drugs to the brain by adenovirus-mediated heterologous expression of human oligopeptide transporter at the blood-brain barrier.
abstract: The feasibility of using adenovirus-mediated human oligopeptide transporter (hPEPT1) gene transfer to achieve peptide drug delivery to the brain across the blood-brain barrier was tested by examining the accumulation of model peptides in a rat brain endothelial cell line (RBEC1) and rat brain after transduction with a recombinant adenovirus encoding hPEPT1-enhanced yellow fluorescent protein fusion gene (AdhPEPT1-EYFP). In vitro uptake of [(3)H]GlySar was determined in RBEC1 transduced with AdhPEPT1-EYFP. In vivo, the accumulation of cefadroxil in rat brain was evaluated after transduction of AdhPEPT1-EYFP. At pH 6.0, the uptake of [(3)H]GlySar by RBEC1 transduced with AdhPEPT1-EYFP was increased 4-fold compared with that of nontransduced cells. At pH 7.4, uptake of [(3)H]GlySar in AdhPEPT1-EYFP transduced RBEC1 was 1.5 times higher than that of nontransduced cells. Unlabeled glycylsarcosine (10 mM) reduced the uptake of [(3)H]GlySar to a level comparable with that of nontransduced cells. At 30 min after intravenous administration of cefadroxil to rats transduced with AdhPEPT1-EYFP at 3.2 x 10(9) plaque-forming units/rat by an in situ brain perfusion method, the brain-to-plasma concentration ratio (Kp) of cefadroxil was increased about 2 times compared with that of nontransduced or AdGFP (control vector)-transduced rats, although this was not statistically significant. In contrast, Kp of [(14)C]inulin, a marker for extracellular fluid space, remained unchanged after adenoviral transduction. In conclusion, our results suggest that adenovirus-mediated heterologous expression of hPEPT1 in vivo could be a useful approach to deliver oligopeptides to the brain.
authors.affiliation: Department of Pharmaceutical Biology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kanazawa, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Toyobuku
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Sai
authors.forename: Toru
authors.initials: T
authors.lastname: Kagami
authors.forename: Ikumi
authors.initials: I
authors.lastname: Tamai
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuji
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001692:Biological Transport; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D026901:Membrane Transport Proteins / Q000096:biosynthesis* / Q000378:metabolism; D010455:Peptides / Q000493:pharmacokinetics; D011107:Polylysine / Q000493:pharmacokinetics*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: D026901:Membrane Transport Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D011107:Polylysine; C043912:peptide permease