Influence of tumor necrosis factor-alpha on the expression and function of P-glycoprotein in an immortalised rat brain capillary endothelial cell line, GPNT.
Drug cerebral pharmacokinetics may be altered in the case of inflammatory diseases. This may be due to a modification of drug transport through the blood-brain barrier, in particular through drug interaction with the membrane efflux transporter, P-glycoprotein. The objective of this study was to investigate the influence of the inflammatory cytokine, tumor necrosis factor (TNF)-alpha, on the functionality and expression of P-glycoprotein, and on mdr1a and mdr1b mRNA expression in immortalised rat brain endothelial cells, GPNT. Cells were treated with TNF-alpha for 4 days. Levels of mdr1a and mdr1b mRNAs were quantitated using real-time RT-PCR analysis and expression of P-glycoprotein was analyzed by Western blot. The functionality of P-glycoprotein was studied by following the accumulation of [3H]vinblastine in the cells without and with a pre-treatment with a P-glycoprotein inhibitor, GF120918. TNF-alpha increased the levels of mdr1a and mdr1b mRNAs while no effect was observed on protein expression. TNF-alpha increased [3H]vinblastine accumulation indicating a time and concentration-dependent decrease of P-glycoprotein activity. This effect was eliminated when the cells were pre-treated with GF120918. Our observation of a decrease in P-glycoprotein activity could suggest that in the case of inflammatory diseases, brain delivery of P-glycoprotein-dependent drugs can be enhanced.
Théron
David
D
Pharmacie Clinique, EA 2706, Université Paris XI, 5 rue Jean-Baptiste Clément, 92296 Châtenay-Malabry, France.
Barraud de Lagerie
Sylvie
S
Tardivel
Sylviane
S
Pélerin
Hélène
H
Demeuse
Philippe
P
Mercier
Claire
C
Mabondzo
Aloïse
A
Farinotti
Robert
R
Lacour
Bernard
B
Roux
Françoise
F
Gimenez
François
F
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D015151:Immunoblotting; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha