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Watson CP, Sekhar GN, Thomas SA. Identification of transport systems involved in eflornithine delivery across the blood-brain barrier. FRONTIERS IN DRUG DELIVERY 2023; 3:1113493. [PMID: 38482132 PMCID: PMC7615738 DOI: 10.3389/fddev.2023.1113493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Human African Trypanosomiasis (HAT) is a neglected parasitic disease that continues to persist in sub-Saharan Africa. It is fatal if untreated. The first stage of the disease is associated with the presence of the parasite in the periphery and the second stage with the presence of the parasites in the CNS. The treatment of CNS stage HAT requires the drugs to cross the blood-brain barrier (BBB). Eflornithine is an amino acid analogue that is used to treat second stage HAT gambiense both alone and in combination with nifurtimox. Recent studies have identified that accumulation of eflornithine into the parasites (trypanosomes) involves the amino acid transporter (Trypanosoma brucei AAT6). In this study we tested the hypothesis that eflornithine uses a cationic amino acid transport system to cross the BBB. We particularly focused on system-y+ and system-B0,+. To do this we utilized specialist databases to compare the physicochemical characteristics of relevant molecules and an in vitro model of the BBB to explore the mechanisms of eflornithine delivery into the CNS. Our results confirmed that eflornithine is related to the endogenous amino acid, ornithine. At pH 7.4, eflornithine is predominately (92.39%) a zwitterionic (dipolar) amino acid and ornithine is predominately (99.08%) a cationic (tripolar) amino acid. In addition, the gross charge distribution at pH 7.4 of eflornithine is much smaller (+0.073) than that of ornithine (+0.99). Further results indicated that eflornithine utilized a saturable transport mechanism(s) to cross the hCMEC/D3 cell membranes and that transport was inhibited by the presence of other amino acids including ornithine. Eflornithine transport was also sodium-independent and sensitive to a y+-system inhibitor, but not a B0,+-system inhibitor. Eflornithine transport was also inhibited by pentamidine, suggestive of transport by organic cation transporters (OCT) which are expressed in this cell line. We confirmed expression of the y+-system protein, CAT1, and the B0,+-system protein, ATB0,+, in the hCMEC/D3 cells. We conclude that eflornithine uses the cationic amino acid transporter, system y+, and OCT to cross the BBB. This research highlights the potential of system-y+ to deliver drugs, including eflornithine, across the BBB to treat brain diseases.
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Affiliation(s)
- Christopher P. Watson
- King’s College London, Institute of Pharmaceutical Science, Franklin-Wilkins Building, Stamford Street, London, UK
| | - Gayathri Nair Sekhar
- King’s College London, Institute of Pharmaceutical Science, Franklin-Wilkins Building, Stamford Street, London, UK
| | - Sarah A Thomas
- King’s College London, Institute of Pharmaceutical Science, Franklin-Wilkins Building, Stamford Street, London, UK
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Shinozaki Y, Tega Y, Akanuma SI, Hosoya KI. The Structural Characteristics of Compounds Interacting with the Amantadine-Sensitive Drug Transport System at the Inner Blood–Retinal Barrier. Pharmaceuticals (Basel) 2023; 16:ph16030435. [PMID: 36986534 PMCID: PMC10053584 DOI: 10.3390/ph16030435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/08/2023] [Accepted: 03/11/2023] [Indexed: 03/14/2023] Open
Abstract
Blood-to-retina transport across the inner blood–retinal barrier (BRB) is a key determinant of retinal drug concentration and pharmacological effect. Recently, we reported on the amantadine-sensitive drug transport system, which is different from well-characterized transporters, at the inner BRB. Since amantadine and its derivatives exhibit neuroprotective effects, it is expected that a detailed understanding of this transport system would lead to the efficient retinal delivery of these potential neuroprotective agents for the treatment of retinal diseases. The objective of this study was to characterize the structural features of compounds for the amantadine-sensitive transport system. Inhibition analysis conducted on a rat inner BRB model cell line indicated that the transport system strongly interacts with lipophilic amines, especially primary amines. In addition, lipophilic primary amines that have polar groups, such as hydroxy and carboxy groups, did not inhibit the amantadine transport system. Furthermore, certain types of primary amines with an adamantane skeleton or linear alkyl chain exhibited a competitive inhibition of amantadine uptake, suggesting that these compounds are potential substrates for the amantadine-sensitive drug transport system at the inner BRB. These results are helpful for producing the appropriate drug design to improve the blood-to-retina delivery of neuroprotective drugs.
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Santos IA, Pereira AKDS, Guevara-Vega M, de Paiva REF, Sabino-Silva R, Bergamini FRG, Corbi PP, Jardim ACG. Repurposing potential of rimantadine hydrochloride and development of a promising platinum(II)-rimantadine metallodrug for the treatment of Chikungunya virus infection. Acta Trop 2022; 227:106300. [PMID: 34979144 DOI: 10.1016/j.actatropica.2021.106300] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/23/2021] [Accepted: 12/29/2021] [Indexed: 11/15/2022]
Abstract
Most of the patients infected with Chikungunya virus (CHIKV) develop chronic manifestations characterized by pain and deformity in joints, impacting their quality of life. The aminoadamantanes, in their turn, have been exploited due to their biological activities, with amantadine and memantine recently described with anti-CHIKV activities. Here we evaluated the antiviral activity of rimantadine hydrochloride (rtdH), a well-known antiviral agent against influenza A, its platinum complex (Pt-rtd), and the precursor cis-[PtCl2(dmso)2], against CHIKV infection in vitro. The rtdH demonstrated significant antiviral activity in all stages of CHIKV replication (29% in pre-treatment; 57% in early stages of infection; 60% in post-entry stages). The Pt-rtd complex protected the cells against infection in 92%, inhibited 100% of viral entry, mainly by a virucidal effect, and impaired 60% of post-entry stages. Alternatively, cis-[PtCl2(dmso)2] impaired viral entry in 100% and post-entry steps in 60%, but had no effect in protecting cells when administered prior to CHIKV infection. Collectively, the obtained data demonstrated that rtdH and Pt-rtd significantly interfered in the early stages of CHIKV life cycle, with the strongest effect observed to Pt-rtd complex, which reduced up to 100% of CHIKV infection. Moreover, molecular docking analysis and infrared spectroscopy data (ATR-FTIR) suggest an interaction of Pt-rtd with CHIKV glycoproteins, potentially related to the mechanism of inhibition of viral entry by Pt-rtd. Through a migration retardation assay, it was also shown that Pt-rtd and cis-[PtCl2(dmso)2] interacted with the dsRNA in 87% and 100%, respectively. The obtained results highlight the repurposing potential of rtdH as an anti-CHIKV drug, as well as the synthesis of promising platinum(II) metallodrugs with potential application for the treatment of CHIKV infections. Importance Chikungunya fever is a disease that can result in persistent symptoms due to the chronic infection process. Infected patients can develop physical disability, resulting and high costs to the health system and significant impacts on the quality of life of affected individuals. Additionally, there are no licensed vaccines or antivirals against the Chikungunya virus (CHIKV) and the virus is easily transmitted due to the abundance of viable vectors in epidemic regions. In this context, our study highlights the repurposing potential of the commercial drug rimantadine hydrochloride (rtdH) as an antiviral agent for the treatment of CHIKV infections. Moreover, our data demonstrated that a platinum(II)-rimantadine metallodrug (Pt-rtd) poses as a potent anti-CHIKV molecule with potential application for the treatment of Chikungunya fever. Altogether, rtdH and Pt-rtd significantly interfered in the early stages of CHIKV life cycle, reducing up to 100% of CHIKV infection in vitro.
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Affiliation(s)
- Igor Andrade Santos
- Laboratory of Virology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia-MG 38405-302, Brazil
| | | | - Marco Guevara-Vega
- Innovation Center in Salivary Diagnostic and Nanotheranostics, Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia, Minas Gerais, Brazil
| | | | - Robinson Sabino-Silva
- Innovation Center in Salivary Diagnostic and Nanotheranostics, Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia, Minas Gerais, Brazil
| | - Fernando R G Bergamini
- Laboratory of Synthesis of Bioinspired Molecules, Institute of Chemistry, Federal University of Uberlândia, Uberlândia-MG 34000-902, Brazil.
| | - Pedro P Corbi
- Institute of Chemistry, University of Campinas-UNICAMP, Campinas-SP 13083-871, Brazil.
| | - Ana Carolina G Jardim
- Laboratory of Virology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia-MG 38405-302, Brazil; Institute of Biosciences, Humanities and Exact Sciences (Ibilce), São Paulo State University (Unesp), Campus São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil.
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Comprehensive Evidence of Carrier-Mediated Distribution of Amantadine to the Retina across the Blood-Retinal Barrier in Rats. Pharmaceutics 2021; 13:pharmaceutics13091339. [PMID: 34575415 PMCID: PMC8469395 DOI: 10.3390/pharmaceutics13091339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 11/20/2022] Open
Abstract
Amantadine, a drug used for the blockage of NMDA receptors, is well-known to exhibit neuroprotective effects. Accordingly, assessment of amantadine transport at retinal barriers could result in the application of amantadine for retinal diseases such as glaucoma. The objective of this study was to elucidate the retinal distribution of amantadine across the inner and outer blood–retinal barrier (BRB). In vivo blood-to-retina [3H]amantadine transport was investigated by using the rat retinal uptake index method, which was significantly reduced by unlabeled amantadine. This result indicated the involvement of carrier-mediated processes in the retinal distribution of amantadine. In addition, in vitro model cells of the inner and outer BRB (TR-iBRB2 and RPE-J cells) exhibited saturable kinetics (Km in TR-iBRB2 cells, 79.4 µM; Km in RPE-J cells, 90.5 and 9830 µM). The inhibition of [3H]amantadine uptake by cationic drugs/compounds indicated a minor contribution of transport systems that accept cationic drugs (e.g., verapamil), as well as solute carrier (SLC) organic cation transporters. Collectively, these outcomes suggest that carrier-mediated transport systems, which differ from reported transporters and mechanisms, play a crucial role in the retinal distribution of amantadine across the inner/outer BRB.
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Gyawali A, Krol S, Kang YS. Involvement of a Novel Organic Cation Transporter in Paeonol Transport Across the Blood-Brain Barrier. Biomol Ther (Seoul) 2019; 27:290-301. [PMID: 30971062 PMCID: PMC6513184 DOI: 10.4062/biomolther.2019.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/15/2019] [Accepted: 02/20/2019] [Indexed: 12/12/2022] Open
Abstract
Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [3H]paeonol in rat brain was about 6-fold higher than that of [14C]sucrose, the vascular space marker of BBB. The uptake of [3H]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [3H]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.
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Affiliation(s)
- Asmita Gyawali
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Sokhoeurn Krol
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
| | - Young-Sook Kang
- College of Pharmacy, Sookmyung Women's University, Seoul 04310, Republic of Korea
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Suzuki T, Aoyama T, Suzuki N, Kobayashi M, Fukami T, Matsumoto Y, Tomono K. Involvement of a proton-coupled organic cation antiporter in the blood-brain barrier transport of amantadine. Biopharm Drug Dispos 2016; 37:323-35. [PMID: 27146715 DOI: 10.1002/bdd.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 04/09/2016] [Accepted: 05/01/2016] [Indexed: 01/18/2023]
Abstract
The blood-to-brain transport of amantadine, a weak N-methyl-d-aspartate (NMDA) antagonist, has been shown previously to participate in the cationic drug-sensitive transport system across the mouse blood-brain barrier (BBB). The purpose of the present study was to characterize the influx transport system by means of both an in situ mouse brain perfusion technique and in vitro studies using rat immortalized brain capillary endothelial cells (GPNT). The observed concentration-dependent initial uptake rate of [(3) H]amantadine suggested the involvement of a carrier-mediated transport mechanism. The normal uptake at physiological pH 7.4 was decreased by 72.9% in acidic perfusate, while it was increased by 35.3% in alkaline perfusate. These results suggest that pH-dependent transport is regulated by utilizing an oppositely directed proton gradient as a driving force. In addition, the [(3) H]amantadine uptake was moderately inhibited by the adamantane structural analogs (rimantadine and memantine) and other cationic drugs (pyrilamine, clonidine, nicotine, etc.), but not by substrates or inhibitors of the well-characterized organic cation transporters (tetraethylammonium, l-carnitine and choline). A similar inhibition pattern was observed between the in vivo studies and the in vitro experiments. These results indicate that the influx transport for amantadine across the BBB involves a proton-coupled organic cation antiporter. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Toyofumi Suzuki
- Laboratory of Pharmaceutics, School of Pharamcy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan.
| | - Takahiko Aoyama
- Laboratory of Clinical Pharmacokinetics, School of Pharamcy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan
| | - Naoto Suzuki
- Laboratory of Pharmaceutics, School of Pharamcy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan
| | - Masaru Kobayashi
- Nihon Pharmaceutical University, Kita-adachi, Saitama, 362-0806, Japan
| | - Toshiro Fukami
- Department of Molecular Pharmaceutics, Meiji Pharmaceutical University, Kiyose, Tokyo, 204-8588, Japan
| | - Yoshiaki Matsumoto
- Laboratory of Clinical Pharmacokinetics, School of Pharamcy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan
| | - Kazuo Tomono
- Laboratory of Pharmaceutics, School of Pharamcy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan
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Jin L, Boyd BJ, Larson IC, Pennington MW, Norton RS, Nicolazzo JA. Enabling Noninvasive Systemic Delivery of the Kv1.3-Blocking Peptide HsTX1[R14A] via the Buccal Mucosa. J Pharm Sci 2016; 105:2173-9. [PMID: 27312508 DOI: 10.1016/j.xphs.2016.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 11/18/2022]
Abstract
The peptide HsTX1[R14A] is a potent and selective blocker of the voltage-gated potassium channel Kv1.3, a well-recognized therapeutic target for autoimmune diseases. To overcome the poor oral absorption and consequent need for regular injections, the potential of the buccal mucosa for systemic delivery of HsTX1[R14A] was investigated. For in vitro studies, FITC-HsTX1[R14A] and HsTX1[R14A], in solution or formulated in a mucoadhesive chitosan-based gel (3%, w/v) with or without cetrimide (5%, w/w), were applied to porcine buccal epithelium mounted between Ussing chambers and buccal mucosal permeation assessed. HsTX1[R14A] was also administered to Swiss outbred mice at a dose of 10 mg/kg in the same formulations. In vitro, administration of FITC-HsTX1[R14A] and HsTX1[R14A] in the chitosan gel containing cetrimide resulted in detectable buccal permeation with 0.75% and 0.58%, respectively, of the applied dose appearing in the receptor chamber over 5 h. After buccal administration to mice, HsTX1[R14A] was detected in plasma, with the presence of cetrimide in the gel further enhancing plasma exposure, with area under the plasma concentration-time curve values of 77.9 ± 9.7 and 31.0 ± 2.3 nM·h, respectively. The buccal mucosa is a promising alternative administration route for the systemic delivery of HsTX1[R14A] for the treatment of autoimmune diseases.
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Affiliation(s)
- Liang Jin
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Ben J Boyd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Ian C Larson
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | | | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
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Suzuki T, Fukami T, Tomono K. Possible involvement of cationic-drug sensitive transport systems in the blood-to-brain influx and brain-to-blood efflux of amantadine across the blood-brain barrier. Biopharm Drug Dispos 2014; 36:126-37. [DOI: 10.1002/bdd.1926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/07/2014] [Accepted: 11/07/2014] [Indexed: 12/25/2022]
Affiliation(s)
- Toyofumi Suzuki
- Laboratory of Pharmaceutics, School of Pharmacy; Nihon University; 7-7-1 Narashinodai Funabashi Chiba 274-8555 Japan
| | - Toshiro Fukami
- Laboratory of Pharmaceutics, School of Pharmacy; Nihon University; 7-7-1 Narashinodai Funabashi Chiba 274-8555 Japan
| | - Kazuo Tomono
- Laboratory of Pharmaceutics, School of Pharmacy; Nihon University; 7-7-1 Narashinodai Funabashi Chiba 274-8555 Japan
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9
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Computational study of adamantanes using floating basis functions. Struct Chem 2014. [DOI: 10.1007/s11224-014-0398-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Tachikawa M, Uchida Y, Ohtsuki S, Terasaki T. Recent Progress in Blood–Brain Barrier and Blood–CSF Barrier Transport Research: Pharmaceutical Relevance for Drug Delivery to the Brain. DRUG DELIVERY TO THE BRAIN 2014. [DOI: 10.1007/978-1-4614-9105-7_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Nies AT, Schaeffeler E, van der Kuip H, Cascorbi I, Bruhn O, Kneba M, Pott C, Hofmann U, Volk C, Hu S, Baker SD, Sparreboom A, Ruth P, Koepsell H, Schwab M. Cellular uptake of imatinib into leukemic cells is independent of human organic cation transporter 1 (OCT1). Clin Cancer Res 2013; 20:985-94. [PMID: 24352644 DOI: 10.1158/1078-0432.ccr-13-1999] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE In addition to mutated BCR-ABL1 kinase, the organic cation transporter 1 (OCT1, encoded by SLC22A1) has been considered to contribute to imatinib resistance in patients with chronic myeloid leukemia (CML). As data are conflicting as to whether OCT1 transports imatinib and may serve as a clinical biomarker, we used a combination of different approaches including animal experiments to elucidate comprehensively the impact of OCT1 on cellular imatinib uptake. EXPERIMENTAL DESIGN Transport of imatinib was studied using OCT1-expressing Xenopus oocytes, mammalian cell lines (HEK293, MDCK, V79) stably expressing OCT1, human leukemic cells, and Oct1-knockout mice. OCT1 mRNA and protein expression were analyzed in leukemic cells from patients with imatinib-naïve CML as well as in cell lines. RESULTS Transport and inhibition studies showed that overexpression of functional OCT1 protein in Xenopus oocytes or mammalian cell lines did not lead to an increased cellular accumulation of imatinib. The CML cell lines (K562, Meg-01, LAMA84) and leukemic cells from patients expressed neither OCT1 mRNA nor protein as demonstrated by immunoblotting and immunofluorescence microscopy, yet they showed a considerable imatinib uptake. Oct1 deficiency in mice had no influence on plasma and hepatic imatinib concentrations. CONCLUSIONS These data clearly demonstrate that cellular uptake of imatinib is independent of OCT1, and therefore OCT1 is apparently not a valid biomarker for imatinib resistance.
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Affiliation(s)
- Anne T Nies
- Authors' Affiliations: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen; Institute of Pharmacy, Department of Pharmacology, University of Tübingen; Department of Clinical Pharmacology, University Hospital Tübingen, Tübingen; Institute of Experimental and Clinical Pharmacology, Second Medical Department, University Hospital Schleswig-Holstein, Campus Kiel; Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany; and Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee
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12
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Mehta DC, Short JL, Nicolazzo JA. Memantine Transport across the Mouse Blood–Brain Barrier Is Mediated by a Cationic Influx H+ Antiporter. Mol Pharm 2013; 10:4491-8. [DOI: 10.1021/mp400316e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Dharmini C. Mehta
- Drug Delivery, Disposition and
Dynamics, and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jennifer L. Short
- Drug Delivery, Disposition and
Dynamics, and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Joseph A. Nicolazzo
- Drug Delivery, Disposition and
Dynamics, and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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13
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Okura T, Kato S, Deguchi Y. Functional expression of organic cation/carnitine transporter 2 (OCTN2/SLC22A5) in human brain capillary endothelial cell line hCMEC/D3, a human blood-brain barrier model. Drug Metab Pharmacokinet 2013; 29:69-74. [PMID: 23877104 DOI: 10.2133/dmpk.dmpk-13-rg-058] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of this study was to examine whether organic cation/carnitine transporter 2 (OCTN2/SLC22A5) plays a role in the human blood-brain barrier (BBB) by evaluating its functional activity in human brain endothelial cells (hCMEC/D3), which are considered to be a model of the BBB. The uptake of [(3)H]L-carnitine by hCMEC/D3 cells was time-, extracellular sodium- and concentration-dependent, with a Km value of 15.7 µM. These results are consistent with the properties of OCTN2-mediated L-carnitine transport. hCMEC/D3 cells showed relatively high expression of OCTN2 mRNA, and this expression was effectively decreased at 24-72 h after lipofection of cells with OCTN2 siRNA under optimized conditions. [(3)H]L-Carnitine uptake was dramatically suppressed by silencing of the OCTN2 gene. The inhibitory effect of OCTN2 gene silencing was similar to that of an excess amount of unlabeled L-carnitine. These results indicate that OCTN2 is involved in L-carnitine transport at the human BBB.
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Affiliation(s)
- Takashi Okura
- Laboratory of Drug Disposition & Pharmacokinetics, Faculty of Pharma-Sciences, Teikyo University
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Species-Dependent Blood-Brain Barrier Disruption of Lipopolysaccharide: Amelioration by Colistin In Vitro and In Vivo. Antimicrob Agents Chemother 2013; 57:4336-4342. [PMID: 23796941 DOI: 10.1128/aac.00765-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/20/2013] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to use in vitro and in vivo models to assess the impact of lipopolysaccharide (LPS) from two different bacterial species on blood-brain barrier (BBB) integrity and brain uptake of colistin. Following repeated administration of LPS from Pseudomonas aeruginosa, the brain-to-plasma ratio of [14C]sucrose in Swiss outbred mice was not significantly increased. Furthermore, while the brain uptake of colistin in mice increased 3-fold following administration of LPS from Salmonella enterica, LPS from P. aeruginosa had no significant effect on colistin brain uptake. This apparent species-dependent effect did not appear to correlate with differences in plasma cytokine levels, as the concentrations of tumor necrosis factor alpha and interleukin-6 following administration of each LPS were not different (P > 0.05). To clarify whether this species-specific effect of LPS was due to direct effects on the BBB, human brain capillary endothelial (hCMEC/D3) cells were treated with LPS from P. aeruginosa or S. enterica and claudin-5 expression was measured by Western blotting. S. enterica LPS significantly (P < 0.05) reduced claudin-5 expression at a concentration of 7.5 μg/ml. In contrast, P. aeruginosa LPS decreased (P < 0.05) claudin-5 expression only at the highest concentration tested (i.e., 30 μg/ml). Coadministration of therapeutic concentrations of colistin ameliorated the S. enterica LPS-induced reduction in claudin-5 expression in hCMEC/D3 cells and the perturbation in BBB function in mice. This study demonstrates that BBB disruption induced by LPS is species dependent, at least between P. aeruginosa and S. enterica, and can be ameliorated by colistin.
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Weksler B, Romero IA, Couraud PO. The hCMEC/D3 cell line as a model of the human blood brain barrier. Fluids Barriers CNS 2013; 10:16. [PMID: 23531482 PMCID: PMC3623852 DOI: 10.1186/2045-8118-10-16] [Citation(s) in RCA: 476] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/25/2013] [Indexed: 12/29/2022] Open
Abstract
Since the first attempts in the 1970s to isolate cerebral microvessel endothelial cells (CECs) in order to model the blood-brain barrier (BBB) in vitro, the need for a human BBB model that closely mimics the in vivo phenotype and is reproducible and easy to grow, has been widely recognized by cerebrovascular researchers in both academia and industry. While primary human CECs would ideally be the model of choice, the paucity of available fresh human cerebral tissue makes wide-scale studies impractical. The brain microvascular endothelial cell line hCMEC/D3 represents one such model of the human BBB that can be easily grown and is amenable to cellular and molecular studies on pathological and drug transport mechanisms with relevance to the central nervous system (CNS). Indeed, since the development of this cell line in 2005 over 100 studies on different aspects of cerebral endothelial biology and pharmacology have been published. Here we review the suitability of this cell line as a human BBB model for pathogenic and drug transport studies and we critically consider its advantages and limitations.
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Weksler B, Romero IA, Couraud PO. The hCMEC/D3 cell line as a model of the human blood brain barrier. Fluids Barriers CNS 2013. [PMID: 23531482 DOI: 10.1186/2045‐8118‐10‐16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Since the first attempts in the 1970s to isolate cerebral microvessel endothelial cells (CECs) in order to model the blood-brain barrier (BBB) in vitro, the need for a human BBB model that closely mimics the in vivo phenotype and is reproducible and easy to grow, has been widely recognized by cerebrovascular researchers in both academia and industry. While primary human CECs would ideally be the model of choice, the paucity of available fresh human cerebral tissue makes wide-scale studies impractical. The brain microvascular endothelial cell line hCMEC/D3 represents one such model of the human BBB that can be easily grown and is amenable to cellular and molecular studies on pathological and drug transport mechanisms with relevance to the central nervous system (CNS). Indeed, since the development of this cell line in 2005 over 100 studies on different aspects of cerebral endothelial biology and pharmacology have been published. Here we review the suitability of this cell line as a human BBB model for pathogenic and drug transport studies and we critically consider its advantages and limitations.
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Shimomura K, Okura T, Kato S, Couraud PO, Schermann JM, Terasaki T, Deguchi Y. Functional expression of a proton-coupled organic cation (H+/OC) antiporter in human brain capillary endothelial cell line hCMEC/D3, a human blood-brain barrier model. Fluids Barriers CNS 2013; 10:8. [PMID: 23351963 PMCID: PMC3564923 DOI: 10.1186/2045-8118-10-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 01/22/2013] [Indexed: 12/26/2022] Open
Abstract
Background Knowledge of the molecular basis and transport function of the human blood–brain barrier (BBB) is important for not only understanding human cerebral physiology, but also development of new central nervous system (CNS)-acting drugs. However, few studies have been done using human brain capillary endothelial cells, because human brain materials are difficult to obtain. The purpose of this study is to clarify the functional expression of a proton-coupled organic cation (H+/OC) antiporter in human brain capillary endothelial cell line hCMEC/D3, which has been recently developed as an in vitro human BBB model. Methods Diphenhydramine, [3H]pyrilamine and oxycodone were used as cationic drugs that proved to be H+/OC antiporter substrates. The in vitro uptake experiments by hCMEC/D3 cells were carried out under several conditions. Results Diphenhydramine and [3H]pyrilamine were both transported into hCMEC/D3 cells in a time- and concentration-dependent manner with Km values of 59 μM and 19 μM, respectively. Each inhibited uptake of the other in a competitive manner, suggesting that a common mechanism is involved in their transport. The diphenhydramine uptake was significantly inhibited by amantadine and quinidine, but not tetraethylammonium and 1-methyl-4-phenylpyridinium (substrates for well-known organic cation transporters). The uptake was inhibited by metabolic inhibitors, but was insensitive to extracellular sodium and membrane potential. Further, the uptake was increased by extracellular alkalization and intracellular acidification. These transport properties are completely consistent with those of previously characterized H+/OC antiporter in rat BBB. Conclusions The present results suggest that H+/OC antiporter is functionally expressed in hCMEC/D3 cells.
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Affiliation(s)
- Keita Shimomura
- Department of Drug Disposition and Pharmacokinetics, School of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo, 173-8605, Japan.
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The promiscuous binding of pharmaceutical drugs and their transporter-mediated uptake into cells: what we (need to) know and how we can do so. Drug Discov Today 2012. [PMID: 23207804 DOI: 10.1016/j.drudis.2012.11.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A recent paper in this journal sought to counter evidence for the role of transport proteins in effecting drug uptake into cells, and questions that transporters can recognize drug molecules in addition to their endogenous substrates. However, there is abundant evidence that both drugs and proteins are highly promiscuous. Most proteins bind to many drugs and most drugs bind to multiple proteins (on average more than six), including transporters (mutations in these can determine resistance); most drugs are known to recognise at least one transporter. In this response, we alert readers to the relevant evidence that exists or is required. This needs to be acquired in cells that contain the relevant proteins, and we highlight an experimental system for simultaneous genome-wide assessment of carrier-mediated uptake in a eukaryotic cell (yeast).
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Computational prediction of CNS drug exposure based on a novel in vivo dataset. Pharm Res 2012; 29:3131-42. [PMID: 22744815 DOI: 10.1007/s11095-012-0806-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 06/08/2012] [Indexed: 01/20/2023]
Abstract
PURPOSE To develop a computational model for predicting CNS drug exposure using a novel in vivo dataset. METHODS The brain-to-plasma (B:P) ratio of 43 diverse compounds was assessed following intravenous administration to Swiss Outbred mice. B:P ratios were subjected to PLS modeling using calculated molecular descriptors. The obtained results were transferred to a qualitative setting in which compounds predicted to have a B:P ratio > 0.3 were sorted as high CNS exposure compounds and those below this value were sorted as low CNS exposure compounds. The model was challenged with an external test set consisting of 251 compounds for which semi-quantitative values of CNS exposure were available in the literature. RESULTS The dataset ranged more than 1700-fold in B:P ratio, with 16 and 27 compounds being sorted as low and high CNS exposure drugs, respectively. The model was a one principal component model based on five descriptors reflecting molecular shape, electronegativity, polarisability and charge transfer, and allowed 74% of the compounds in the training set and 76% of the test set to be predicted correctly. CONCLUSION A qualitative computational model has been developed which accurately classifies compounds as being high or low CNS exposure drugs based on rapidly calculated molecular descriptors.
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