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 Adh-PEPT1-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 ϫ 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.

Small molecular drug transfer across the blood-brain barrier via carrier-mediated transport systems

“…Toyobuku et al 86 examined the feasibility of heterologous transduction of a transporter gene to the BBB. As peptides have multiple biological actions in the brain, they are potentially valuable as neuropharmaceuticals in the treatment of various disorders, such as Alzheimer's disease and depression.…”

“…Delivery of peptide drugs to the brain, however, is a major challenge, because distribution of peptides to the brain is generally very low owing to the presence of the BBB. Toyobuku et al 86 constructed a recombinant adenovirus vector encoding PEPT1 and transduced the transporter into the BBB of rats by carotid artery injection of the vector. Heterologous expression of PEPT1 at the BBB successfully increased the brain distribution of a model substrate, cefadroxil, of PEPT1.…”

“…Heterologous expression of PEPT1 at the BBB successfully increased the brain distribution of a model substrate, cefadroxil, of PEPT1. 86 Malignant gliomas are the most common primary neoplasms of the CNS. The prognosis for high-grade malignant gliomas remains bleak; survival is generally less than 1 year.…”

Influx transporters and drug targeting: Application of peptide and cation transporters

“…Toyobuku et al [42] examined the feasibility of heterologous transduction of a transporter gene to the BBB. As peptides have multiple biological actions in the brain, they are potentially valuable as neuropharmaceuticals in the treatment of various disorders, such as Alzheimer's disease and depression.…”

Enhanced gene transfer into brain capillary endothelial cells using Antp-modified DNA-loaded nanoparticles

“…It has been reported that BCECs could secrete gene products into the brain parenchyma by a paracrine mechanism [1]. Additionally, the heterologous expression of oligopeptide transporters at the brain capillary endothelium has been found to be capable of delivering peptide drugs to the brain [2]. Therefore, it is of great significance to develop an effective method for gene transfer into BCECs.…”