title: Isolation of peptide transport system-6 from brain endothelial cells: therapeutic effects with antisense inhibition in Alzheimer and stroke models.
abstract: By isolating for the first time ever a peptide transporter from the blood-brain barrier (BBB) and developing an antisense that selectively targets the brain-to-blood efflux component, we were able to deliver a therapeutic concentration of the neurotrophic peptide pituitary adenylate cyclase-activating polypeptide (PACAP) 27 to brain in animal models of Alzheimer's and stroke. Efflux pumps at the BBB are major causes of BBB impermeability to peptides. PACAP is neuroprotective in vitro in femtomole amounts, but brain uptake of PACAP27 is limited by an efflux component of peptide transport system-6 (PTS-6). Here, we characterized, isolated, and sequenced this component of PTS-6, identifying it as beta-F1 ATPase, and colocalized it with PACAP27 on BBB endothelial cells. Antisenses targeting the BBB inhibited PACAP27 efflux, thus increasing brain uptake of PACAP27. Treatment with antisense+PACAP27 improved cognition in a mouse model of Alzheimer's disease and reduced infarct size after cerebral ischemia. This represents the first isolation from BBB tissue of a peptide transporter and shows that inhibition of peptide efflux pumps is a potential strategy for drug delivery to brain.
authors.affiliation: Faculty of Pharmacy, Anadolu University, Eskisehir, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Dogrukol-Ak
authors.forename: Vijaya B
authors.initials: VB
authors.lastname: Kumar
authors.forename: Jan S
authors.initials: JS
authors.lastname: Ryerse
authors.forename: Susan A
authors.initials: SA
authors.lastname: Farr
authors.forename: Sulekha
authors.initials: S
authors.lastname: Verma
authors.forename: Naoko
authors.initials: N
authors.lastname: Nonaka
authors.forename: Tomoya
authors.initials: T
authors.lastname: Nakamachi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ohtaki
authors.forename: Michael L
authors.initials: ML
authors.lastname: Niehoff
authors.forename: John C
authors.initials: JC
authors.lastname: Edwards
authors.forename: Seiji
authors.initials: S
authors.lastname: Shioda
authors.forename: John E
authors.initials: JE
authors.lastname: Morley
authors.forename: William A
authors.initials: WA
authors.lastname: Banks
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000544:Alzheimer Disease / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000628:therapy; D000818:Animals; D001921:Brain / Q000201:enzymology*; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000201:enzymology*; D015316:Genetic Therapy; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D051379:Mice; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000378:metabolism; D011485:Protein Binding; D020521:Stroke / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000628:therapy
chemical_list: D026901:Membrane Transport Proteins; D016376:Oligonucleotides, Antisense; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; C043912:peptide permease; D000251:Adenosine Triphosphatases