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Pervaiz I, Mehta Y, Sherill K, Patel D, Al-Ahmad AJ. Ketone bodies supplementation restores the barrier function, induces a metabolic switch, and elicits beta-hydroxybutyrate diffusion across a monolayer of iPSC-derived brain microvascular endothelial cells. Microvasc Res 2023; 150:104585. [PMID: 37437687 DOI: 10.1016/j.mvr.2023.104585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/14/2023]
Abstract
Glucose constitutes the main source of energy for the central nervous system (CNS), its entry occurring at the blood-brain barrier (BBB) via the presence of glucose transporter 1 (GLUT1). However, under food intake restrictions, the CNS can utilize ketone bodies (KB) as an alternative source of energy. Notably, the relationship between the BBB and KBs and its effect on their glucose metabolism remains poorly understood. In this study, we investigated the effect of glucose deprivation on the brain endothelium in vitro, and supplementation with KBs using induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial cell-like cells (iBMECs). Glucose-free environment significantly decreased cell metabolic activity and negatively impacted the barrier function. In addition, glucose deprivation did not increase GLUT1 expression but also resulted in a decrease in glucose uptake and glycolysis. Supplementation of glucose-deprived iBMECs monolayers with KB showed no improvement and even worsened upon treatment with acetoacetate. However, under a hypoglycemic condition in the presence of KBs, we noted a slight improvement of the barrier function, with no changes in glucose uptake. Notably, hypoglycemia and/or KB pre-treatment elicited a saturable beta-hydroxybutyrate diffusion across iBMECs monolayers, such diffusion occurred partially via an MCT1-dependent mechanism. Taken together, our study highlights the importance of glucose metabolism and the reliance of the brain endothelium on glucose and glycolysis for its function, such dependence is unlikely to be covered by KBs supplementation. In addition, KB diffusion at the BBB appeared induced by KB pre-treatment and appears to involve an MCT1-dependent mechanism.
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Affiliation(s)
- Iqra Pervaiz
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America.
| | - Yash Mehta
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Kinzie Sherill
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Dhavalkumar Patel
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America
| | - Abraham J Al-Ahmad
- Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy Department of Pharmaceutical Sciences, Amarillo, TX, United States of America; Center for Blood-Brain Barrier Research, Texas Tech University Health Sciences Center - Jerry H. Hodge School of Pharmacy, Amarillo, TX, United States of America.
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Latif S, Kang YS. Blood-Brain Barrier Solute Carrier Transporters and Motor Neuron Disease. Pharmaceutics 2022; 14:2167. [PMID: 36297602 PMCID: PMC9608738 DOI: 10.3390/pharmaceutics14102167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/22/2022] [Accepted: 10/04/2022] [Indexed: 01/21/2024] Open
Abstract
Defective solute carrier (SLC) transporters are responsible for neurotransmitter dysregulation, resulting in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). We provided the role and kinetic parameters of transporters such as ASCTs, Taut, LAT1, CAT1, MCTs, OCTNs, CHT, and CTL1, which are mainly responsible for the transport of essential nutrients, acidic, and basic drugs in blood-brain barrier (BBB) and motor neuron disease. The affinity for LAT1 was higher in the BBB than in the ALS model cell line, whereas the capacity was higher in the NSC-34 cell lines than in the BBB. Affinity for MCTs was lower in the BBB than in the NSC-34 cell lines. CHT in BBB showed two affinity sites, whereas no expression was observed in ALS cell lines. CTL1 was the main transporter for choline in ALS cell lines. The half maximal inhibitory concentration (IC50) analysis of [3H]choline uptake indicated that choline is sensitive in TR-BBB cells, whereas amiloride is most sensitive in ALS cell lines. Knowledge of the transport systems in the BBB and motor neurons will help to deliver drugs to the brain and develop the therapeutic strategy for treating CNS and neurological diseases.
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Affiliation(s)
| | - Young-Sook Kang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, 100 Cheongpa-ro 47-gil, Yongsan-gu, Seoul 04310, Korea
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Gyawali A, Latif S, Choi SH, Hyeon SJ, Ryu H, Kang YS. Monocarboxylate transporter functions and neuroprotective effects of valproic acid in experimental models of amyotrophic lateral sclerosis. J Biomed Sci 2022; 29:2. [PMID: 35012534 PMCID: PMC8744235 DOI: 10.1186/s12929-022-00785-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/04/2022] [Indexed: 12/11/2022] Open
Abstract
Background Amyotrophic lateral sclerosis (ALS) is a devasting neurodegenerative disorder for which no successful therapeutics are available. Valproic acid (VPA), a monocarboxylate derivative, is a known antiepileptic drug and a histone deacetylase inhibitor.
Methods To investigate whether monocarboxylate transporter 1 (MCT1) and sodium-coupled MCT1 (SMCT1) are altered in ALS cell and mouse models, a cellular uptake study, quantitative real time polymerase chain reaction and western blot parameters were used. Similarly, whether VPA provides a neuroprotective effect in the wild-type (WT; hSOD1WT) and ALS mutant-type (MT; hSOD1G93A) NSC-34 motor neuron-like cell lines was determined through the cell viability assay.
Results [3H]VPA uptake was dependent on time, pH, sodium and concentration, and the uptake rate was significantly lower in the MT cell line than the WT cell line. Interestingly, two VPA transport systems were expressed, and the VPA uptake was modulated by SMCT substrates/inhibitors in both cell lines. Furthermore, MCT1 and SMCT1 expression was significantly lower in motor neurons of ALS (G93A) model mice than in those of WT mice. Notably, VPA ameliorated glutamate- and hydrogen peroxide-induced neurotoxicity in both the WT and MT ALS cell lines. Conclusions Together, the current findings demonstrate that VPA exhibits a neuroprotective effect regardless of the dysfunction of an MCT in ALS, which could help develop useful therapeutic strategies for ALS.
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Affiliation(s)
- Asmita Gyawali
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Cheongpa-ro 47-gil 100 (Cheongpa-dong 2ga), Yongsan-gu, Seoul, 04310, Republic of Korea
| | - Sana Latif
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Cheongpa-ro 47-gil 100 (Cheongpa-dong 2ga), Yongsan-gu, Seoul, 04310, Republic of Korea
| | - Seung-Hye Choi
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - Seung Jae Hyeon
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - Hoon Ryu
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - Young-Sook Kang
- College of Pharmacy and Drug Information Research Institute, Sookmyung Women's University, Cheongpa-ro 47-gil 100 (Cheongpa-dong 2ga), Yongsan-gu, Seoul, 04310, Republic of Korea.
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Han H, Mann A, Ekstein D, Eyal S. Breaking Bad: the Structure and Function of the Blood-Brain Barrier in Epilepsy. AAPS JOURNAL 2017; 19:973-988. [DOI: 10.1208/s12248-017-0096-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 04/28/2017] [Indexed: 12/27/2022]
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Spilioti M, Pavlou E, Gogou M, Katsanika I, Papadopoulou-Alataki E, Grafakou O, Gkampeta A, Dinopoulos A, Evangeliou A. Valproate effect on ketosis in children under ketogenic diet. Eur J Paediatr Neurol 2016; 20:555-9. [PMID: 27117552 DOI: 10.1016/j.ejpn.2016.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/28/2016] [Accepted: 04/06/2016] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Although ketogenic diet has been proven useful in the management of intractable seizures, interactions with other medicines have been reported. This study reports two patients on co-administration with ketogenic diet and valproate appearing undesirable side effects after increase or decrease of valproate pharmaceutical levels. METHODS Totally 75 patients suffering from drug-resistant epilepsy were treated with ketogenic diet in our departments. Their age varied from 6 months to 9 years. All patients were followed for at least 12 months and up to five years. Clinical and laboratory variables have been regularly assessed. RESULTS In 75 patients treated with ketogenic diet and valproate at the same time treatment was well tolerated. Two patients presented mild to moderate undesirable effects. In these patients the removal of valproate treatment resulted in an increase of ketosis with respective clinical signs. The conversion of the diet from 4:1 to 1:1 and 2,5:1 respectively resulted in reduction of ketosis and clinical improvement. CONCLUSION In the majority of cases co-administration of valproate and ketogenic diet seems to be safe. In two cases, valproate appeared to have a negative effect on ketosis (and weaning it led to over-ketosis). This interaction is worthy of future study.
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Affiliation(s)
- Martha Spilioti
- 1st Department of Neurology, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece; 2nd Department of Pediatrics, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece
| | - Evangelos Pavlou
- 1st Department of Neurology, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece; 2nd Department of Pediatrics, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece
| | - Maria Gogou
- 4th Department of Pediatrics, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece.
| | - Irene Katsanika
- 4th Department of Pediatrics, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece
| | - Efimia Papadopoulou-Alataki
- 4th Department of Pediatrics, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece
| | - Olga Grafakou
- 4th Department of Pediatrics, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece
| | - Anastasia Gkampeta
- 1st Department of Neurology, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece; 2nd Department of Pediatrics, Aristotle University of Thessaloniki, University General Hospital AHEPA, Thessaloniki, Greece
| | - Argyrios Dinopoulos
- 3rd Department of Pediatrics, University of Athens, Attikon Hospital, Athens, Greece
| | - Athanasios Evangeliou
- 4th Department of Pediatrics, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece
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In Vivo and In Vitro Evidence for Brain Uptake of 4-Phenylbutyrate by the Monocarboxylate Transporter 1 (MCT1). Pharm Res 2016; 33:1711-22. [PMID: 27026010 DOI: 10.1007/s11095-016-1912-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
Abstract
PURPOSE 4-Phenylbutyrate (4-PBA) is expected to be a potential therapeutic for several neurodegenerative diseases. These activities require 4-PBA transport into the brain across the blood-brain barrier (BBB). The objective of the present study was to characterize the brain transport mechanism of 4-PBA through the BBB. METHODS The brain transport of 4-PBA across the BBB was investigated following intravenous (IV) injection and internal carotid artery perfusion (ICAP) in vivo. The mechanism of transport was examined using TR-BBB cells, an in vitro model of the BBB. RESULTS The volume of distribution (VD) of 4-PBA by rat brain was about 7-fold greater than that of sucrose, a BBB impermeable vascular space marker, suggesting the blood-to-brain transport of 4-PBA through the BBB in the physiological state. [(14)C]4-PBA uptake by TR-BBB cells showed time-, pH- and concentration-dependence with a K m of 13.4 mM at pH 7.4 and 3.22 mM at pH 6.0. The uptake was Na(+) independent, and was significantly inhibited by alpha-cyano-4-hydroxycinnamate (a typical inhibitor for monocarboxylate transport), endogenous monocarboxylate compounds and monocarboxylic drugs. Lactate and valproate competitively inhibited [(14)C]4-PBA uptake with K i value of 13.5 mM and 7.47 mM, respectively. These results indicate the role of monocarboxylate transporters (MCTs) in 4-PBA transport into the brain at the BBB. TR-BBB cells expressed mRNA of rMCT1, 2, and 4, especially, rMCT1 showed high mRNA expression level. In addition, [(14)C]4-PBA uptake was inhibited by rMCT1 specific small interfering RNA. CONCLUSION The transport mechanism of 4-PBA from blood to brain across the BBB likely involves MCT1.
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Sasaki S, Futagi Y, Ideno M, Kobayashi M, Narumi K, Furugen A, Iseki K. Effect of diclofenac on SLC16A3/MCT4 by the Caco-2 cell line. Drug Metab Pharmacokinet 2016; 31:218-23. [PMID: 27236641 DOI: 10.1016/j.dmpk.2016.03.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/19/2016] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
Abstract
In the present study, we demonstrated that monocarboxylate transporter 4 (MCT4) is functionally expressed in Caco-2 cells. We studied the effects of 4 nonsteroidal anti-inflammatory drugs on the uptake of l-lactate as a good substrate of MCT4 by the cells. The monocarboxylate drugs inhibited the uptake of l-lactate into the cells. Diclofenac, as a member of the aryl-acetic acid group of nonsteroidal anti-inflammatory drugs, was the most potent inhibitor, with an inhibition constant of 20 μM. In the next study, we determined the type of inhibition for diclofenac. An l-lactate carrier is non-competitively inhibitable by the drug. We also demonstrated, in Xenopus oocyte expression system, potential of diclofenac for MCT4 inhibitor. The present results could provide a useful tool to discover MCT4-specific inhibitors.
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Affiliation(s)
- Shotaro Sasaki
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Yuya Futagi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Masaya Ideno
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Masaki Kobayashi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Katsuya Narumi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Ayako Furugen
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan
| | - Ken Iseki
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharmasciences, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12-jo, Nishi-6-chome, Kita-ku, Sapporo 060-0812, Japan; Department of Pharmacy, Hokkaido University Hospital, Sapporo 060-8648, Japan.
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Soares RV, Do TM, Mabondzo A, Pons G, Chhun S. Ontogeny of ABC and SLC transporters in the microvessels of developing rat brain. Fundam Clin Pharmacol 2016; 30:107-16. [PMID: 26662930 DOI: 10.1111/fcp.12175] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/19/2015] [Accepted: 12/08/2015] [Indexed: 01/01/2023]
Abstract
The blood-brain barrier (BBB) is responsible for the control of solutes' concentration in the brain. Tight junctions and multiple ATP-binding cassette (ABC) and SoLute Carrier (SLC) efflux transporters protect brain cells from xenobiotics, therefore reducing brain exposure to intentionally administered drugs. In epilepsy, polymorphisms and overexpression of efflux transporters genes could be associated with pharmacoresistance. The ontogeny of these efflux transporters should also be addressed because their expression during development may be related to different brain exposure to antiepileptic drugs in the immature brain. We detected statistically significant higher expression of Abcb1b and Slc16a1 genes, and lower expression of Abcb1a and Abcg2 genes between the post-natal day 14 (P14) and the adult rat microvessels. P-gP efflux activity was also shown to be lower in P14 rats when compared with the adults. The P-gP proteins coded by rodent genes Abcb1a and Abcb1b are known to have different substrate affinities. The role of the Abcg2 gene is less clear in pharmacoresistance in epilepsy, nonetheless the coded protein Bcrp is frequently associated with drug resistance. Finally, we observed a higher expression of the Mct1 transporter gene in the P14 rat brain microvessels. Accordingly to our results, we suppose that age may be another factor influencing brain exposure to antiepileptics as a consequence of different expression patterns of efflux transporters between the adult and immature BBB.
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Affiliation(s)
- Ricardo V Soares
- Inserm U1129, Paris, France.,University Paris Descartes, Faculty of Medicine, Paris, France.,CEA, Direction des Sciences du Vivant, iBiTec-S, Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Tuan M Do
- CEA, Direction des Sciences du Vivant, iBiTec-S, Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Aloïse Mabondzo
- CEA, Direction des Sciences du Vivant, iBiTec-S, Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Gérard Pons
- Inserm U1129, Paris, France.,University Paris Descartes, Faculty of Medicine, Paris, France
| | - Stéphanie Chhun
- University Paris Descartes, Faculty of Medicine, Paris, France.,Inserm U1151, INEM, Paris, France.,APHP, Hôpital Universitaire Necker-Enfants Malades, Laboratoire d'immunologie biologique, Paris, France
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Kell DB. The transporter-mediated cellular uptake of pharmaceutical drugs is based on their metabolite-likeness and not on their bulk biophysical properties: Towards a systems pharmacology. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.pisc.2015.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Mikitsh JL, Chacko AM. Pathways for small molecule delivery to the central nervous system across the blood-brain barrier. PERSPECTIVES IN MEDICINAL CHEMISTRY 2014; 6:11-24. [PMID: 24963272 PMCID: PMC4064947 DOI: 10.4137/pmc.s13384] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 01/04/2023]
Abstract
The treatment of central nervous system (CNS) disease has long been difficult due to the ineffectiveness of drug delivery across the blood-brain barrier (BBB). This review summarizes important concepts of the BBB in normal versus pathophysiology and how this physical, enzymatic, and efflux barrier provides necessary protection to the CNS during drug delivery, and consequently treatment challenging. Small molecules account for the vast majority of available CNS drugs primarily due to their ability to penetrate the phospholipid membrane of the BBB by passive or carrier-mediated mechanisms. Physiochemical and biological factors relevant for designing small molecules with optimal capabilities for BBB permeability are discussed, as well as the most promising classes of transporters suitable for small-molecule drug delivery. Clinically translatable imaging methodologies for detecting and quantifying drug uptake and targeting in the brain are discussed as a means of further understanding and refining delivery parameters for both drugs and imaging probes in preclinical and clinical domains. This information can be used as a guide to design drugs with preserved drug action and better delivery profiles for improved treatment outcomes over existing therapeutic approaches.
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Affiliation(s)
- John L Mikitsh
- Department of Radiology, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ann-Marie Chacko
- Department of Radiology, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Targeted Therapeutics and Translational Nanomedicine, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Lauritzen F, Eid T, Bergersen LH. Monocarboxylate transporters in temporal lobe epilepsy: roles of lactate and ketogenic diet. Brain Struct Funct 2013; 220:1-12. [PMID: 24248427 DOI: 10.1007/s00429-013-0672-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/05/2013] [Indexed: 11/29/2022]
Abstract
Epilepsy is a serious neurological disorder that affects approximately 1 % of the general population, making it one of the most common disorders of the central nervous system. Furthermore, up to 40 % of all patients with epilepsy cannot control their seizures with current medications. More efficacious treatments for medication refractory epilepsy are therefore needed. A better understanding of the mechanisms that cause this disorder is likely to facilitate the discovery of such treatments. Impairment in cerebral energy metabolism has been proposed as a possible causative factor in the pathogenesis of temporal lobe epilepsy (TLE), which is one of the most common types of medication-refractory epilepsies in adults. In this review, we will discuss some of the current hypotheses regarding the possible causal relationship between brain energy metabolism and TLE. Emphasis will be placed on the role of energy substrates (lactate and ketone bodies) and their transporter molecules, particularly monocarboxylate transporters 1 and 2 (MCT1 and MCT2). We recently reported that the cellular distribution of MCT1 and MCT2 is perturbed in the hippocampus in patients with TLE. The changes may be an adaptive response aimed at keeping high levels of lactate in the epileptic tissue, which may serve to counteract epileptic activity by downregulating cAMP levels through the lactate receptor GPR81, newly discovered in hippocampus. We propose that the perturbation of MCTs may be further involved in the pathophysiology of TLE by influencing brain energy homeostasis, mitochondrial function, GABA-ergic and glutamatergic neurotransmission, and flux of lactate through the brain.
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Affiliation(s)
- Fredrik Lauritzen
- The Brain and Muscle Energy Group, Department of Anatomy and Department of Oral Biology, University of Oslo, P.O. Box 1105, Blindern, 0317, Oslo, Norway
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Padowski JM, Pollack GM. Influence of enterohepatic recycling on the time course of brain-to-blood partitioning of valproic acid in rats. Drug Metab Dispos 2012; 40:1846-53. [PMID: 22715475 DOI: 10.1124/dmd.112.045500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
A widely used metric of substrate exposure in brain is the brain-to-serum partition coefficient (K(p,brain); C(brain)/C(serum)), most appropriately determined at distribution equilibrium between brain tissue and serum. In some cases, C(brain)/C(serum) can peak and then decrease, as opposed to monotonically increasing to a plateau, precluding accurate estimation of partitioning. This "overshoot" has been observed with compounds that undergo enterohepatic recycling (ER), such as valproic acid (VPA). Previous simulation experiments identified a relationship between overshoot in the C(brain)/C(serum) versus time profile and distribution into a peripheral "compartment" (e.g., the ER loop). This study was conducted to evaluate model predictions of that relationship. Initial experiments tested the ability of activated charcoal, antibiotics, or Mrp2 deficiency to impair VPA ER in rats, thereby limiting the apparent volume of distribution associated with ER. Mrp2 deficiency (significantly) and antibiotics (moderately) interrupted VPA ER. Subsequently, brain partitioning was evaluated in the presence versus absence of ER modulation. Although overshoot was not eliminated completely, deconvolution revealed that overshoot was reduced in Mrp2-deficient and antibiotic-treated rats. Consistent with model predictions, overshoot was higher after antibiotic treatment (moderate ER interruption) than in Mrp2 deficiency (substantial ER interruption). Steady-state K(p,brain) was unaffected by experimental manipulation, also consistent with model predictions. These data support the hypothesis that C(brain)/C(serum) may overshoot K(p,brain) based on the extent of peripheral sequestration. Consideration of this information, particularly for compounds that undergo significant extravascular distribution, may be necessary to avoid erroneous estimation of K(p,brain).
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Affiliation(s)
- Jeannie M Padowski
- Curriculum in Toxicology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Berendsen S, Broekman M, Seute T, Snijders T, van Es C, de Vos F, Regli L, Robe P. Valproic acid for the treatment of malignant gliomas: review of the preclinical rationale and published clinical results. Expert Opin Investig Drugs 2012; 21:1391-415. [DOI: 10.1517/13543784.2012.694425] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Pierre Robe
- UMC Utrecht,
Utrecht, Netherlands
- University of Liège,
Liège, Belgium
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Naik P, Cucullo L. In vitro blood-brain barrier models: current and perspective technologies. J Pharm Sci 2011; 101:1337-54. [PMID: 22213383 DOI: 10.1002/jps.23022] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/21/2011] [Accepted: 12/01/2011] [Indexed: 01/22/2023]
Abstract
Even in the 21st century, studies aimed at characterizing the pathological paradigms associated with the development and progression of central nervous system diseases are primarily performed in laboratory animals. However, limited translational significance, high cost, and labor to develop the appropriate model (e.g., transgenic or inbred strains) have favored parallel in vitro approaches. In vitro models are of particular interest for cerebrovascular studies of the blood-brain barrier (BBB), which plays a critical role in maintaining the brain homeostasis and neuronal functions. Because the BBB dynamically responds to many events associated with rheological and systemic impairments (e.g., hypoperfusion), including the exposure of potentially harmful xenobiotics, the development of more sophisticated artificial systems capable of replicating the vascular properties of the brain microcapillaries are becoming a major focus in basic, translational, and pharmaceutical research. In vitro BBB models are valuable and easy to use supporting tools that can precede and complement animal and human studies. In this article, we provide a detailed review and analysis of currently available in vitro BBB models ranging from static culture systems to the most advanced flow-based and three-dimensional coculture apparatus. We also discuss recent and perspective developments in this ever expanding research field.
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Affiliation(s)
- Pooja Naik
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, Texas 79106, USA
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Haque S, Md S, Alam MI, Sahni JK, Ali J, Baboota S. Nanostructure-based drug delivery systems for brain targeting. Drug Dev Ind Pharm 2011; 38:387-411. [PMID: 21954902 DOI: 10.3109/03639045.2011.608191] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
CONTEXT It is well-known fact that blood brain barrier (BBB) hinders the penetrance and access of many pharmacotherapeutic agents to central nervous system (CNS). Many diseases of the CNS remain undertreated and the inability to treat most CNS disorders is not due to the lack of effective CNS drug discovery, rather, it is due to the ineffective CNS delivery. Therefore, a number of nanostructured drug delivery carriers have been developed and explored over the past couple of years to transport the drugs to brain. OBJECTIVE The present review will give comprehensive details of extensive research being done in field of nanostructured carriers to transport the drugs through the BBB in a safe and effective manner. METHODS The method includes both the polymeric- and lipid-based nanocarriers with emphasis on their utility, methodology, advantages, and the drugs which have been worked on using a particular approach to provide a noninvasive method to improve the drug transport through BBB. RESULTS Polymeric- and lipid-based nanocarriers enter brain capillaries before reaching the surface of the brain microvascular endothelial cells without the disruption of BBB. These systems are further modified with specific ligands vectors and pegylation aiming to target and enhance their binding with surface receptors of the specific tissues inside brain and increase long circulatory time which favors interaction and penetration into brain endothelial cells. CONCLUSION This review would give an insight to the researchers working on neurodegenerative and non-neurodegenerative diseases of the CNS including brain tumor.
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Lauritzen F, Perez EL, Melillo ER, Roh JM, Zaveri HP, Lee TSW, Wang Y, Bergersen LH, Eid T. Altered expression of brain monocarboxylate transporter 1 in models of temporal lobe epilepsy. Neurobiol Dis 2011; 45:165-76. [PMID: 21856423 DOI: 10.1016/j.nbd.2011.08.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 07/15/2011] [Accepted: 08/03/2011] [Indexed: 12/22/2022] Open
Abstract
Monocarboxylate transporter 1 (MCT1) facilitates the transport of monocarboxylate fuels (lactate, pyruvate and ketone bodies) and acidic drugs, such as valproic acid, across cell membranes. We recently reported that MCT1 is deficient on microvessels in the epileptogenic hippocampal formation in patients with medication-refractory temporal lobe epilepsy (TLE). To further define the role of MCT1 in the pathophysiology of TLE, we used immunohistochemistry and stereological analysis to localize and quantify the transporter in the hippocampal formation in three novel and highly relevant rat models of TLE and in nonepileptic control animals. One model utilizes methionine sulfoximine to induce brain glutamine synthetase deficiency and recurrent limbic seizures, while two models employ an episode of perforant pathway stimulation to cause epilepsy. MCT1 was lost on microvessels and upregulated on astrocytes in the hippocampal formation in all models of TLE. Notably, the loss of MCT1 on microvessels was not due to a reduction in microvessel density. The similarities in MCT1 expression among human subjects with TLE and several animal models of the disease strongly suggest a critical role of this molecule in the pathogenesis of TLE. We hypothesize that the downregulation of MCT1 may promote seizures via impaired uptake of ketone bodies and antiepileptic drugs by the epileptogenic brain. We also propose that the overexpression of MCT1 on astrocytes may lead to increased uptake or release of monocarboxylates by these cells, with important implications for brain metabolism and excitability. These hypotheses can now be rigorously tested in several animal models that replicate key features of human TLE.
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Affiliation(s)
- Fredrik Lauritzen
- Department of Laboratory Medicine, Yale University School of Medicine, P.O. Box 208035, New Haven, CT 06520, USA
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Peura L, Malmioja K, Laine K, Leppänen J, Gynther M, Isotalo A, Rautio J. Large Amino Acid Transporter 1 (LAT1) Prodrugs of Valproic Acid: New Prodrug Design Ideas for Central Nervous System Delivery. Mol Pharm 2011; 8:1857-66. [DOI: 10.1021/mp2001878] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Lauri Peura
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Kalle Malmioja
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Krista Laine
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Jukka Leppänen
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Mikko Gynther
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Antti Isotalo
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Jarkko Rautio
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
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Terbach N, Shah R, Kelemen R, Klein PS, Gordienko D, Brown NA, Wilkinson CJ, Williams RSB. Identifying an uptake mechanism for the antiepileptic and bipolar disorder treatment valproic acid using the simple biomedical model Dictyostelium. J Cell Sci 2011; 124:2267-76. [PMID: 21652627 DOI: 10.1242/jcs.084285] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Valproic acid (VPA) is the most highly prescribed epilepsy treatment worldwide and is also used to prevent bipolar disorder and migraine. Surprisingly, very little is known about its mechanisms of cellular uptake. Here, we employ a range of cellular, molecular and genetic approaches to characterize VPA uptake using a simple biomedical model, Dictyostelium discoideum. We show that VPA is taken up against an electrochemical gradient in a dose-dependent manner. Transport is protein-mediated, dependent on pH and the proton gradient and shows strong substrate structure specificity. Using a genetic screen, we identified a protein homologous to a mammalian solute carrier family 4 (SLC4) bicarbonate transporter that we show is involved in VPA uptake. Pharmacological and genetic ablation of this protein reduces the uptake of VPA and partially protects against VPA-dependent developmental effects, and extracellular bicarbonate competes for VPA uptake in Dictyostelium. We further show that this uptake mechanism is likely to be conserved in both zebrafish (Danio rerio) and Xenopus laevis model systems. These results implicate, for the first time, an uptake mechanism for VPA through SLC4-catalysed activity.
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Affiliation(s)
- Nicole Terbach
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham TW200EX, UK
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Monocarboxylate transporter 1 is deficient on microvessels in the human epileptogenic hippocampus. Neurobiol Dis 2010; 41:577-84. [PMID: 21081165 DOI: 10.1016/j.nbd.2010.11.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 11/01/2010] [Accepted: 11/09/2010] [Indexed: 11/20/2022] Open
Abstract
Monocarboxylate transporter 1 (MCT1) facilitates the transport of important metabolic fuels (lactate, pyruvate and ketone bodies) and possibly also acidic drugs such as valproic acid across the blood-brain barrier. Because an impaired brain energy metabolism and resistance to antiepileptic drugs are common features of temporal lobe epilepsy (TLE), we sought to study the expression of MCT1 in the brain of patients with this disease. Immunohistochemistry and immunogold electron microscopy were used to assess the distribution of MCT1 in brain specimens from patients with TLE and concomitant hippocampal sclerosis (referred to as mesial TLE or MTLE (n=15)), patients with TLE and no hippocampal sclerosis (non-MTLE, n=13) and neurologically normal autopsy subjects (n=8). MCT1 was present on an extensive network of microvessels throughout the hippocampal formation in autopsy controls and to a lesser degree in non-MTLE. Patients with MTLE were markedly deficient in MCT1 on microvessels in several areas of the hippocampal formation, especially CA1, which exhibited a 37% to 48% loss of MCT1 on the plasma membrane of endothelial cells when compared with non-MTLE. These findings suggest that the uptake of blood-derived monocarboxylate fuels and possibly also acidic drugs, such as valproic acid, is perturbed in the epileptogenic hippocampus, particularly in MTLE. We hypothesize that the loss of MCT1 on brain microvessels is mechanistically involved in the pathophysiology of drug-resistant TLE, and propose that re-expression of MCT1 may represent a novel therapeutic approach for this disease.
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Fischer W, Bernhagen J, Neubert RHH, Brandsch M. Uptake of codeine into intestinal epithelial (Caco-2) and brain endothelial (RBE4) cells. Eur J Pharm Sci 2010; 41:31-42. [PMID: 20510359 DOI: 10.1016/j.ejps.2010.05.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 04/27/2010] [Accepted: 05/16/2010] [Indexed: 01/11/2023]
Abstract
Orally administered codeine has to permeate both the intestinal and the blood-brain barrier in order to act as analgesic and cough suppressant. In this study we characterized the uptake of codeine at intestinal epithelial (Caco-2) and brain endothelial (RBE4) cells. At both cell types, uptake of [(3)H]codeine was independent of an inwardly directed Na(+) gradient. Uptake was, however, strongly stimulated by an outwardly directed H(+) gradient and inhibited by the protonophore FCCP. [(3)H]Codeine uptake into Caco-2 cells was strongly temperature dependent. In the presence of excess amounts of unlabeled codeine, the uptake was inhibited by up to 87% (Caco-2) or 94% (RBE4), respectively. Synthetic opioids and some non-opioid organic cations like propranolol, pyrilamine and quinidine potently inhibited [(3)H]codeine uptake. Several prototype substrates of known transporters for amino acids, neurotransmitters and organic cations were ineffective. Our data are consistent with a hypothetic saturable, H(+)-dependent (antiport) mechanism not yet identified on a molecular level. The pH dependence of codeine uptake and its intracellular accumulation can partially also be explained by a model comprising diffusional membrane permeation of unionized species of codeine followed by codeine sequestration into acidic vesicles and distribution into cellular lipids.
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Affiliation(s)
- Wiebke Fischer
- Membrane Transport Group, Biozentrum, Martin-Luther-University Halle-Wittenberg, Weinbergweg 22, D-06120 Halle, Germany
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Luna-Tortós C, Fedrowitz M, Löscher W. Evaluation of transport of common antiepileptic drugs by human multidrug resistance-associated proteins (MRP1, 2 and 5) that are overexpressed in pharmacoresistant epilepsy. Neuropharmacology 2010; 58:1019-32. [PMID: 20080116 DOI: 10.1016/j.neuropharm.2010.01.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 01/06/2010] [Accepted: 01/07/2010] [Indexed: 12/27/2022]
Abstract
Resistance to antiepileptic drugs (AEDs) is one of the most serious problems in the treatment of epilepsy. Accumulating experimental evidence suggests that increased expression of the drug efflux transporter P-glycoprotein (Pgp) at the blood-brain barrier may be involved in the mechanisms leading to AED resistance. In addition to Pgp, increased expression of several multidrug resistance-associated proteins (MRPs) has been determined in epileptogenic brain regions of patients with pharmacoresistant epilepsy. However, it is not known whether AEDs are substrates for MRPs. In the present experiments, we evaluated whether common AEDs are transported by human MRPs (MRP1, 2 and 5) that are overexpressed in AED resistant epilepsy. For this purpose, we used a highly sensitive assay (concentration equilibrium transport assay; CETA) in polarized kidney cell lines (LLC, MDCKII) transfected with human MRPs. The assay was validated by known MRP substrates, including calcein-AM (MRP1), vinblastine (MRP2) and chloromethylfluorescein diacetate (CMFDA; MRP5). The directional transport determined with these drugs in MRP-transfected cell lines could be blocked with the MRP inhibitor MK571. However, in contrast to transport of known MRP substrates, none of the common AEDs (carbamazepine, valproate, levetiracetam, phenytoin, lamotrigine and phenobarbital) used in this study was transported by MRP1, MRP2 or MRP5. A basolateral-to-apical transport of valproate, which could be inhibited by MK571 and probenecid, was determined in LLC cells (both wildtype and transfected), but the specific transporter involved was not identified. The data indicate that common AEDs are not substrates for human MRP1, MRP2 or MRP5, at least in the in vitro models used in this study.
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Affiliation(s)
- Carlos Luna-Tortós
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany
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Eyal S, Hsiao P, Unadkat JD. Drug interactions at the blood-brain barrier: fact or fantasy? Pharmacol Ther 2009; 123:80-104. [PMID: 19393264 DOI: 10.1016/j.pharmthera.2009.03.017] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Accepted: 03/20/2009] [Indexed: 12/24/2022]
Abstract
There is considerable interest in the therapeutic and adverse outcomes of drug interactions at the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). These include altered efficacy of drugs used in the treatment of CNS disorders, such as AIDS dementia and malignant tumors, and enhanced neurotoxicity of drugs that normally penetrate poorly into the brain. BBB- and BCSFB-mediated interactions are possible because these interfaces are not only passive anatomical barriers, but are also dynamic in that they express a variety of influx and efflux transporters and drug metabolizing enzymes. Based on studies in rodents, it has been widely postulated that efflux transporters play an important role at the human BBB in terms of drug delivery. Furthermore, it is assumed that chemical inhibition of transporters or their genetic ablation in rodents is predictive of the magnitude of interaction to be expected at the human BBB. However, studies in humans challenge this well-established paradigm and claim that such drug interactions will be lesser in magnitude but yet may be clinically significant. This review focuses on current known mechanisms of drug interactions at the blood-brain and blood-CSF barriers and the potential impact of such interactions in humans. We also explore whether such drug interactions can be predicted from preclinical studies. Defining the mechanisms and the impact of drug-drug interactions at the BBB is important for improving efficacy of drugs used in the treatment of CNS disorders while minimizing their toxicity as well as minimizing neurotoxicity of non-CNS drugs.
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Affiliation(s)
- Sara Eyal
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington 98195, USA
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