title: Regulation of BCRP (ABCG2) and P-glycoprotein (ABCB1) by cytokines in a model of the human blood-brain barrier.
abstract: Brain capillary endothelial cells form the blood-brain barrier (BBB), a highly selective permeability membrane between the blood and the brain. Besides tight junctions that prevent small hydrophilic compounds from passive diffusion into the brain tissue, the endothelial cells express different families of drug efflux transport proteins that limit the amount of substances penetrating the brain. Two prominent efflux transporters are the breast cancer resistance protein and P-glycoprotein (P-gp). During inflammatory reactions, which can be associated with an altered BBB, pro-inflammatory cytokines are present in the systemic circulation. We, therefore, investigated the effect of the pro-inflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) on the expression and activity of BCRP and P-gp in the human hCMEC/D3 cell line. BCRP mRNA levels were significantly reduced by IL-1beta, IL-6 and TNF-alpha. The strongest BCRP suppression at the protein level was observed after IL-1beta treatment. IL-1beta, IL-6 and TNF-alpha also significantly reduced the BCRP activity as assessed by mitoxantrone uptake experiments. P-gp mRNA levels were slightly reduced by IL-6, but significantly increased after TNF-alpha treatment. TNF-alpha also increased protein expression of P-gp but the uptake of the P-gp substrate rhodamine 123 was not affected by any of the cytokines. This in vitro study indicates that expression levels and activity of BCRP, and P-gp at the BBB may be altered by acute inflammation, possibly affecting the penetration of their substrates into the brain.
authors.affiliation: Department of Clinical Pharmacology and Toxicology, University Hospital of Basel, Basel, Switzerland.
authors.forename: Birk
authors.initials: B
authors.lastname: Poller
authors.forename: Jürgen
authors.initials: J
authors.lastname: Drewe
authors.forename: Stephan
authors.initials: S
authors.lastname: Krähenbühl
authors.forename: Jörg
authors.initials: J
authors.lastname: Huwyler
authors.forename: Heike
authors.initials: H
authors.lastname: Gutmann
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism*; D002460:Cell Line; D016207:Cytokines / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008942:Mitoxantrone / Q000494:pharmacology; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020112:Rhodamine 123 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C116614:ABCG2 protein, human; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D020112:Rhodamine 123; D008942:Mitoxantrone