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Mairinger S, Leterrier S, Filip T, Löbsch M, Pahnke J, Hernández-Lozano I, Stanek J, Tournier N, Zeitlinger M, Hacker M, Langer O, Wanek T. [ 11C]metoclopramide is a sensitive radiotracer to measure moderate decreases in P-glycoprotein function at the blood-brain barrier. J Cereb Blood Flow Metab 2024; 44:142-152. [PMID: 37728771 PMCID: PMC10905639 DOI: 10.1177/0271678x231202336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/23/2023] [Accepted: 08/27/2023] [Indexed: 09/21/2023]
Abstract
The efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier limits the cerebral uptake of various xenobiotics. To assess the sensitivity of [11C]metoclopramide to measure decreased cerebral P-gp function, we performed [11C]metoclopramide PET scans without (baseline) and with partial P-gp inhibition by tariquidar in wild-type, heterozygous Abcb1a/b(+/-) and homozygous Abcb1a/b(-/-) mice as models with controlled levels of cerebral P-gp expression. Brains were collected to quantify P-gp expression with immunohistochemistry. Brain uptake of [11C]metoclopramide was expressed as the area under the brain time-activity curve (AUCbrain) and compared with data previously obtained with (R)-[11C]verapamil and [11C]N-desmethyl-loperamide. Abcb1a/b(+/-) mice had intermediate P-gp expression compared to wild-type and Abcb1a/b(-/-) mice. In baseline scans, all three radiotracers were able to discriminate Abcb1a/b(-/-) from wild-type mice (2.5- to 4.6-fold increased AUCbrain, p ≤ 0.0001). However, only [11C]metoclopramide could discriminate Abcb1a/b(+/-) from wild-type mice (1.46-fold increased AUCbrain, p ≤ 0.001). After partial P-gp inhibition, differences in [11C]metoclopramide AUCbrain between Abcb1a/b(+/-) and wild-type mice (1.39-fold, p ≤ 0.001) remained comparable to baseline. There was a negative correlation between baseline [11C]metoclopramide AUCbrain and ex-vivo-measured P-gp immunofluorescence (r = -0.9875, p ≤ 0.0001). Our data suggest that [11C]metoclopramide is a sensitive radiotracer to measure moderate, but (patho-)physiologically relevant decreases in cerebral P-gp function without the need to co-administer a P-gp inhibitor.
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Affiliation(s)
- Severin Mairinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Sarah Leterrier
- Laboratoire d'Imagerie Biomédicale Multimodale (BIOMAPS), Université Paris-Saclay, CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Thomas Filip
- Core Facility Laboratory Animal Breeding and Husbandry, Medical University of Vienna, Vienna, Austria
- Institute of Animal Breeding and Genetics & Biomodels Austria, University of Veterinary Medicine, Vienna, Austria
| | - Mathilde Löbsch
- Core Facility Laboratory Animal Breeding and Husbandry, Medical University of Vienna, Vienna, Austria
| | - Jens Pahnke
- Department of Pathology, Section of Neuropathology Research, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
- Drug Development and Chemical Biology Lab, Lübeck Institute of Dermatology (LIED), University of Lübeck, Lübeck, Germany
- Department of Pharmacology, Faculty of Medicine, University of Latvia, Rīga, Latvia
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | | | - Johann Stanek
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Nicolas Tournier
- Laboratoire d'Imagerie Biomédicale Multimodale (BIOMAPS), Université Paris-Saclay, CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Oliver Langer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Thomas Wanek
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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Liu W, Mossel P, Schwach V, Slart RHJA, Luurtsema G. Cardiac PET Imaging of ATP Binding Cassette (ABC) Transporters: Opportunities and Challenges. Pharmaceuticals (Basel) 2023; 16:1715. [PMID: 38139840 PMCID: PMC10748140 DOI: 10.3390/ph16121715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Adenosine triphosphate binding cassette (ABC) transporters are a broad family of membrane protein complexes that use energy to transport molecules across cells and/or intracellular organelle lipid membranes. Many drugs used to treat cardiac diseases have an affinity for these transporters. Among others, P-glycoprotein (P-gp) plays an essential role in regulating drug concentrations that reach cardiac tissue and therefore contribute to cardiotoxicity. As a molecular imaging modality, positron emission tomography (PET) has emerged as a viable technique to investigate the function of P-gp in organs and tissues. Using PET imaging to evaluate cardiac P-gp function provides new insights for drug development and improves the precise use of medications. Nevertheless, information in this field is limited. In this review, we aim to examine the current applications of ABC transporter PET imaging and its tracers in the heart, with a specific emphasis on P-gp. Furthermore, the opportunities and challenges in this novel field will be discussed.
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Affiliation(s)
- Wanling Liu
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; (W.L.); (P.M.)
| | - Pascalle Mossel
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; (W.L.); (P.M.)
| | - Verena Schwach
- Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, 7500 AE Enschede, The Netherlands;
| | - Riemer H. J. A. Slart
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; (W.L.); (P.M.)
- Department of Biomedical Photonic Imaging, University of Twente, 7500 AE Enschede, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; (W.L.); (P.M.)
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Mossel P, Arif WM, De Souza GS, Varela LG, van der Weijden CWJ, Boersma HH, Willemsen ATM, Boellaard R, Elsinga PH, Borra RJH, Dierckx RAJO, Lammertsma AA, Bartels AL, Luurtsema G. Quantification of P-glycoprotein function at the human blood-brain barrier using [ 18F]MC225 and PET. Eur J Nucl Med Mol Imaging 2023; 50:3917-3927. [PMID: 37552369 PMCID: PMC10611838 DOI: 10.1007/s00259-023-06363-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023]
Abstract
INTRODUCTION P-glycoprotein (P-gp) is one of the most studied efflux transporters at the blood-brain barrier. It plays an important role in brain homeostasis by protecting the brain from a variety of endogenous and exogeneous substances. Changes in P-gp function are associated both with the onset of neuropsychiatric diseases, including Alzheimer's disease and Parkinson's disease, and with drug-resistance, for example in treatment-resistant depression. The most widely used approach to measure P-gp function in vivo is (R)-[11C]verapamil PET. (R)-[11C]verapamil is, however, an avid P-gp substrate, which complicates the use of this tracer to measure an increase in P-gp function as its baseline uptake is already very low. [18F]MC225 was developed to measure both increases and decreases in P-gp function. AIM The aim of this study was (1) to identify the pharmacokinetic model that best describes [18F]MC225 kinetics in the human brain and (2) to determine test-retest variability. METHODS Five (2 male, 3 female) of fourteen healthy subjects (8 male, 6 female, age 67 ± 5 years) were scanned twice (injected dose 201 ± 47 MBq) with a minimum interval of 2 weeks between scans. Each scanning session consisted of a 60-min dynamic [18F]MC225 scan with continuous arterial sampling. Whole brain grey matter data were fitted to a single tissue compartment model, and to reversible and irreversible two tissue-compartment models to obtain various outcome parameters (in particular the volume of distribution (VT), Ki, and the rate constants K1 and k2). In addition, a reversible two-tissue compartment model with fixed k3/k4 was included. The preferred model was selected based on the weighted Akaike Information Criterion (AIC) score. Test-retest variability (TRTV) was determined to assess reproducibility. RESULTS Sixty minutes post-injection, the parent fraction was 63.8 ± 4.0%. The reversible two tissue compartment model corrected for plasma metabolites with an estimated blood volume (VB) showed the highest AIC weight score of 34.3 ± 17.6%. The TRVT of the VT for [18F]MC225 PET scans was 28.3 ± 20.4% for the whole brain grey matter region using this preferred model. CONCLUSION [18F]MC225 VT, derived using a reversible two-tissue compartment model, is the preferred parameter to describe P-gp function in the human BBB. This outcome parameter has an average test-retest variability of 28%. TRIAL REGISTRATION EudraCT 2020-001564-28 . Registered 25 May 2020.
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Affiliation(s)
- Pascalle Mossel
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Wejdan M Arif
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- College of Applied Medical Science, Department of Radiological Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Giordana Salvi De Souza
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Lara Garcia Varela
- Molecular Imaging Biomarkers Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela (USC), 15706, Santiago de Compostela, Spain
- Nuclear Medicine Department and Molecular Imaging Group, Health Research Institute of Santiago de Compostela (IDIS), SERGAS, 15706, Santiago de Compostela, Spain
| | - Chris W J van der Weijden
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hendrikus H Boersma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Antoon T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ronald Boellaard
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Radiology and Nuclear Medicine, UMC, Location VUmc, Amsterdam, The Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ronald J H Borra
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Adriaan A Lammertsma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Anna L Bartels
- Department of Neurology, Ommelander Ziekenhuis Groep, Scheemda, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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Lee RL, Funk KE. Imaging blood–brain barrier disruption in neuroinflammation and Alzheimer’s disease. Front Aging Neurosci 2023; 15:1144036. [PMID: 37009464 PMCID: PMC10063921 DOI: 10.3389/fnagi.2023.1144036] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/28/2023] [Indexed: 03/19/2023] Open
Abstract
The blood–brain barrier (BBB) is the neurovascular structure that regulates the passage of cells and molecules to and from the central nervous system (CNS). Alzheimer’s disease (AD) is a neurodegenerative disorder that is associated with gradual breakdown of the BBB, permitting entry of plasma-derived neurotoxins, inflammatory cells, and microbial pathogens into the CNS. BBB permeability can be visualized directly in AD patients using imaging technologies including dynamic contrast-enhanced and arterial spin labeling magnetic resonance imaging, and recent studies employing these techniques have shown that subtle changes in BBB stability occur prior to deposition of the pathological hallmarks of AD, senile plaques, and neurofibrillary tangles. These studies suggest that BBB disruption may be useful as an early diagnostic marker; however, AD is also accompanied by neuroinflammation, which can complicate these analyses. This review will outline the structural and functional changes to the BBB that occur during AD pathogenesis and highlight current imaging technologies that can detect these subtle changes. Advancing these technologies will improve both the diagnosis and treatment of AD and other neurodegenerative diseases.
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Harris WJ, Asselin MC, Hinz R, Parkes LM, Allan S, Schiessl I, Boutin H, Dickie BR. In vivo methods for imaging blood-brain barrier function and dysfunction. Eur J Nucl Med Mol Imaging 2023; 50:1051-1083. [PMID: 36437425 PMCID: PMC9931809 DOI: 10.1007/s00259-022-05997-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/09/2022] [Indexed: 11/29/2022]
Abstract
The blood-brain barrier (BBB) is the interface between the central nervous system and systemic circulation. It tightly regulates what enters and is removed from the brain parenchyma and is fundamental in maintaining brain homeostasis. Increasingly, the BBB is recognised as having a significant role in numerous neurological disorders, ranging from acute disorders (traumatic brain injury, stroke, seizures) to chronic neurodegeneration (Alzheimer's disease, vascular dementia, small vessel disease). Numerous approaches have been developed to study the BBB in vitro, in vivo, and ex vivo. The complex multicellular structure and effects of disease are difficult to recreate accurately in vitro, and functional aspects of the BBB cannot be easily studied ex vivo. As such, the value of in vivo methods to study the intact BBB cannot be overstated. This review discusses the structure and function of the BBB and how these are affected in diseases. It then discusses in depth several established and novel methods for imaging the BBB in vivo, with a focus on MRI, nuclear imaging, and high-resolution intravital fluorescence microscopy.
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Affiliation(s)
- William James Harris
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Marie-Claude Asselin
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
| | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK
| | - Laura Michelle Parkes
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Stuart Allan
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Ingo Schiessl
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK
| | - Herve Boutin
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
| | - Ben Robert Dickie
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, University of Manchester, Manchester, UK
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Impact of Cytochrome Induction or Inhibition on the Plasma and Brain Kinetics of [ 11C]metoclopramide, a PET Probe for P-Glycoprotein Function at the Blood-Brain Barrier. Pharmaceutics 2022; 14:pharmaceutics14122650. [PMID: 36559144 PMCID: PMC9785688 DOI: 10.3390/pharmaceutics14122650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022] Open
Abstract
[11C]metoclopramide PET imaging provides a sensitive and translational tool to explore P-glycoprotein (P-gp) function at the blood-brain barrier (BBB). Patients with neurological diseases are often treated with cytochrome (CYP) modulators which may impact the plasma and brain kinetics of [11C]metoclopramide. The impact of the CYP inducer carbamazepine or the CYP inhibitor ritonavir on the brain and plasma kinetics of [11C]metoclopramide was investigated in rats. Data obtained in a control group were compared with groups that were either orally pretreated with carbamazepine (45 mg/kg twice a day for 7 days before PET) or ritonavir (20 mg/kg, 3 h before PET) (n = 4 per condition). Kinetic modelling was performed to estimate the brain penetration (VT) of [11C]metoclopramide. CYP induction or inhibition had negligible impact on the plasma kinetics and metabolism of [11C]metoclopramide. Moreover, carbamazepine neither impacted the brain kinetics nor VT of [11C]metoclopramide (p > 0.05). However, ritonavir significantly increased VT (p < 0.001), apparently behaving as an inhibitor of P-gp at the BBB. Our data suggest that treatment with potent CYP inducers such as carbamazepine does not bias the estimation of P-gp function at the BBB with [11C]metoclopramide PET. This supports further use of [11C]metoclopramide for studies in animals and patients treated with CYP inducers.
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Kumar P, Thakur R, Acharya PC, Mohan HK, Pallavi UN, Maheshwari D, Mohammed K M A, Kumar A, Goud Nerella S, Joshi RK, Kumar M, Nagaraj C. Synthesis, characterization, and radiosynthesis of fluorine-18-AVT-011 as a Pgp chemoresistance imaging marker. Sci Rep 2022; 12:18584. [PMID: 36329151 PMCID: PMC9633701 DOI: 10.1038/s41598-022-22930-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
P-glycoprotein (Pgp) is the most studied ATP-binding cassette (ABC) efflux transporter and contributes to chemoresistance. A few tracers have been developed to detect the in-vivo status of chemoresistance using positron emission tomography (PET) imaging. In our study, we have synthesized labeled AVT-011 with fluorine-18 (18F) followed by in-vitro and in-vivo analysis. Tosylate AVT-011 precursor was synthesized and characterized by 1H-NMR and 13C-NMR. AVT-011 was labeled with 18F using the nucleophilic substitution method, and a standard set of quality control was performed. The specificity for Pgp was tested in U87MG cells with and without an inhibitor (tariquidar). The biodistribution and in-vivo stability were tested in the small animals (mice). The biodistribution data of [18F]-AVT-011 was extracted from the PET-CT imaging of breast cancer patients (n = 6). The precursor was synthesized with 36 ± 4% yield and 97 ± 2% purity. The labeling was more than 95% with a 42 ± 2% yield, as evaluated by Radio-HPLC. The cell-binding assay showed a specificity of the tracer for Pgp as the uptake increased by twice after blocking the Pgp receptors. The radiotracer showed a hepatorenal excretion pathway for clearance in an animal study. The uptake was higher in the liver, lungs, spleen, and heart at 15 min and decreased at 60 min. The patients' distribution showed similar uptake patterns as observed in the small animals. [18F]AVT-011 was characterized successfully with high radiochemical purity and yield. The in-vitro and in-vivo studies proved its specificity for Pgp and safe for patient use.
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Affiliation(s)
- Pardeep Kumar
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Riptee Thakur
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Pratap Chandra Acharya
- grid.444729.80000 0000 8668 6322Department of Pharmacy, Tripura University (A Central University), Suryamaninagar, Tripura (W) India
| | - Hosahalli K. Mohan
- Department of Nuclear Medicine, Sri Shankara Cancer Hospital & Research Centre, Bengaluru, Karnataka India
| | - U. N. Pallavi
- Department of Nuclear Medicine, Sri Shankara Cancer Hospital & Research Centre, Bengaluru, Karnataka India
| | | | | | - Aishwarya Kumar
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Sridhar Goud Nerella
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Raman Kumar Joshi
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Manoj Kumar
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
| | - Chandana Nagaraj
- grid.416861.c0000 0001 1516 2246Department of Neuroimaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka India
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Dose-response assessment of cerebral P-glycoprotein inhibition in vivo with [ 18F]MC225 and PET. J Control Release 2022; 347:500-507. [PMID: 35588934 DOI: 10.1016/j.jconrel.2022.05.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 11/20/2022]
Abstract
The Blood-Brain Barrier P-glycoprotein (P-gp) function can be altered in several neurodegenerative diseases and due to the administration of different drugs which may cause alterations in drug concentrations and consequently lead to a reduced effectiveness or increased side-effects. The novel PET radiotracer [18F]MC225 is a weak P-gp substrate that may show higher sensitivity to detect small changes in P-gp function than previously developed radiotracers. This study explores the sensitivity of [18F]MC225 to measure the dose-dependent effect of P-gp inhibitor tariquidar. Twenty-three rats were intravenously injected with different doses of tariquidar ranging from 0.75 to 12 mg/kg, 30-min before the dynamic [18F]MC225-PET acquisition with arterial sampling. Tissue and blood data were fitted to a 1-Tissue-Compartment-Model to obtain influx constant K1 and distribution volume VT, which allow the estimation of P-gp function. ANOVA and post-hoc analyses of K1 values showed significant differences between controls and groups with tariquidar doses >3 mg/kg; while applying VT the analyses showed significant differences between controls and groups with tariquidar doses >6 mg/kg. Dose-response curves were fitted using different models. The four-parameter logistic sigmoidal curve provided the best fit for K1 and VT data. Half-maximal inhibitory doses (ID50) were 2.23 mg/kg (95%CI: 1.669-2.783) and 2.93 mg/kg (95%CI: 1.135-3.651), calculated with K1 or VT values respectively. According to the dose-response fit, differences in [18F]MC225-K1 values could be detected at tariquidar doses ranging from 1.37 to 3.25 mg/kg. Our findings showed that small changes in the P-gp function, caused by low doses of tariquidar, could be detected by [18F]MC225-K1 values, which confirms the high sensitivity of the radiotracer. The results suggest that [18F]MC225 may allow the quantification of moderate P-gp impairments, which may allow the detection of P-gp dysfunctions at the early stages of a disease and potential transporter-mediated drug-drug interactions.
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Ni R. Positron Emission Tomography in Animal Models of Alzheimer's Disease Amyloidosis: Translational Implications. Pharmaceuticals (Basel) 2021; 14:1179. [PMID: 34832961 PMCID: PMC8623863 DOI: 10.3390/ph14111179] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Animal models of Alzheimer's disease amyloidosis that recapitulate cerebral amyloid-beta pathology have been widely used in preclinical research and have greatly enabled the mechanistic understanding of Alzheimer's disease and the development of therapeutics. Comprehensive deep phenotyping of the pathophysiological and biochemical features in these animal models is essential. Recent advances in positron emission tomography have allowed the non-invasive visualization of the alterations in the brain of animal models and in patients with Alzheimer's disease. These tools have facilitated our understanding of disease mechanisms and provided longitudinal monitoring of treatment effects in animal models of Alzheimer's disease amyloidosis. In this review, we focus on recent positron emission tomography studies of cerebral amyloid-beta accumulation, hypoglucose metabolism, synaptic and neurotransmitter receptor deficits (cholinergic and glutamatergic system), blood-brain barrier impairment, and neuroinflammation (microgliosis and astrocytosis) in animal models of Alzheimer's disease amyloidosis. We further propose the emerging targets and tracers for reflecting the pathophysiological changes and discuss outstanding challenges in disease animal models and future outlook in the on-chip characterization of imaging biomarkers towards clinical translation.
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Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH & University of Zurich, 8093 Zurich, Switzerland;
- Institute for Regenerative Medicine, University of Zurich, 8952 Zurich, Switzerland
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Toyohara J, Sakata M, Ishibashi K, Mossel P, Imai M, Wagatsuma K, Tago T, Imabayashi E, Colabufo NA, Luurtsema G, Ishii K. First clinical assessment of [ 18F]MC225, a novel fluorine-18 labelled PET tracer for measuring functional P-glycoprotein at the blood-brain barrier. Ann Nucl Med 2021; 35:1240-1252. [PMID: 34368924 DOI: 10.1007/s12149-021-01666-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/02/2021] [Indexed: 12/01/2022]
Abstract
OBJECTIVE 5-(1-(2-[18F]fluoroethoxy))-[3-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-propyl]-5,6,7,8-tetrahydronaphthalen ([18F]MC225) is a selective substrate for P-glycoprotein (P-gp), possessing suitable properties for measuring overexpression of P-gp in the brain. This is the first-in-human study to examine safety, radiation dosimetry and P-gp function at the blood-brain barrier (BBB) of [18F]MC225 in healthy subjects. METHODS [18F]MC225 biodistribution and dosimetry were determined in 3 healthy male subjects, using serial 2 h and intermittent 4 and 6 h whole-body PET scans acquired after [18F]MC225 injection. Dynamic [18F]MC225 brain PET (90 min) was obtained in 5 healthy male subjects. Arterial blood was sampled at various time intervals during scanning and the fraction of unchanged [18F]MC225 in plasma was determined. T1-weighted MRI was performed for anatomical coregistration. Total distribution volume (VT) was estimated using 1- and 2-tissue-compartment models (1-TCM and 2-TCM, respectively). VT was also estimated using the Logan graphical method (Logan plot) (t* = 20 min). Surrogate parameters without blood sampling (area-under the curve [AUC] of regional time-activity curves [TACs] and negative slope of calculated TACs) were compared with the VT values. RESULTS No serious adverse events occurred throughout the study period. Although biodistribution implied hepatobiliary excretion, secretion of radioactivity from liver to small intestine through the gallbladder was very slow. Total renal excreted radioactivity recovered during 6 h after injection was < 2%ID. Absorbed dose was the highest in the pancreas (mean ± SD, 203 ± 45 μGy/MBq) followed by the liver (83 ± 11 μGy/MBq). Mean effective dose with and without urination was 17 ± 1 μSv/MBq. [18F]MC225 readily entered the brain, distributing homogeneously in grey matter regions. 2-TCM provided lower Akaike information criterion scores than did 1-TCM. VT estimated by Logan plot was well correlated with that of 2-TCM (r2 > 0.9). AUCs of TACs were positively correlated with VT (2-TCM) values (r2: AUC0-60 min = 0.61, AUC0-30 min = 0.62, AUC30-60 min = 0.59, p < 0.0001). Negative slope of SUV TACs was negatively correlated with VT (2-TCM) values (r2 = 0.53, p < 0.0001). CONCLUSIONS This initial evaluation indicated that [18F]MC225 is a suitable and safe PET tracer for measuring P-gp function at the BBB.
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Affiliation(s)
- Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Muneyuki Sakata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kenji Ishibashi
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Pascalle Mossel
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Masamichi Imai
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kei Wagatsuma
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.,School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan
| | - Tetsuro Tago
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Etsuko Imabayashi
- Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Nicola A Colabufo
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari, via Orabona 4, 70125, Bari, Italy
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Kenji Ishii
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
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11
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García-Varela L, Rodríguez-Pérez M, Custodia A, Moraga-Amaro R, Colabufo NA, Aguiar P, Sobrino T, Dierckx RA, van Waarde A, Elsinga PH, Luurtsema G. In Vivo Induction of P-Glycoprotein Function can be Measured with [ 18F]MC225 and PET. Mol Pharm 2021; 18:3073-3085. [PMID: 34228458 PMCID: PMC8383301 DOI: 10.1021/acs.molpharmaceut.1c00302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022]
Abstract
P-Glycoprotein (P-gp) is an efflux pump located at the blood-brain barrier (BBB) that contributes to the protection of the central nervous system by transporting neurotoxic compounds out of the brain. A decline in P-gp function has been related to the pathogenesis of neurodegenerative diseases. P-gp inducers can increase the P-gp function and are considered as potential candidates for the treatment of such disorders. The P-gp inducer MC111 increased P-gp expression and function in SW480 human colon adenocarcinoma and colo-320 cells, respectively. Our study aims to evaluate the P-gp inducing effect of MC111 in the whole brain in vivo, using the P-gp tracer [18F]MC225 and positron emission tomography (PET). Eighteen Wistar rats were treated with either vehicle solution, 4.5 mg/kg of MC111 (low-dose group), or 6 mg/kg of MC111 (high-dose group). Animals underwent a 60 min dynamic PET scan with arterial-blood sampling, 24 h after treatment with the inducer. Data were analyzed using the 1-tissue-compartment model and metabolite-corrected plasma as the input function. Model parameters such as the influx constant (K1) and volume of distribution (VT) were calculated, which reflect the in vivo P-gp function. P-gp and pregnane xenobiotic receptor (PXR) expression levels of the whole brain were assessed using western blot. The administration of MC111 decreased K1 and VT of [18F]MC225 in the whole brain and all of the selected brain regions. In the high-dose group, whole-brain K1 was decreased by 34% (K1-high-dose = 0.20 ± 0.02 vs K1-control = 0.30 ± 0.02; p < 0.001) and in the low-dose group by 7% (K1-low-dose = 0.28 ± 0.02 vs K1-control = 0.30 ± 0.02; p = 0.42) compared to controls. Whole-brain VT was decreased by 25% in the high-dose group (VT-high-dose = 5.92 ± 0.41 vs VT-control = 7.82 ± 0.38; p < 0.001) and by 6% in the low-dose group (VT-low-dose = 7.35 ± 0.38 vs VT-control = 7.82 ± 0.37; p = 0.38) compared to controls. k2 values did not vary after treatment. The treatment did not affect the metabolism of [18F]MC225. Western blot studies using the whole-brain tissue did not detect changes in the P-gp expression, however, preliminary results using isolated brain capillaries found an increasing trend up to 37% in treated rats. The decrease in K1 and VT values after treatment with the inducer indicates an increase in the P-gp functionality at the BBB of treated rats. Moreover, preliminary results using brain endothelial cells also sustained the increase in the P-gp expression. In conclusion, the results verify that MC111 induces P-gp expression and function at the BBB in rats. An increasing trend regarding the P-gp expression levels is found using western blot and an increased P-gp function is confirmed with [18F]MC225 and PET.
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Affiliation(s)
- Lara García-Varela
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Manuel Rodríguez-Pérez
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Antía Custodia
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Rodrigo Moraga-Amaro
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Nicola A. Colabufo
- Dipartimento
di Farmacia-Scienze del Farmaco, Università
degli Studi di Bari, I-70125 Bari, Italy
| | - Pablo Aguiar
- Department
of Nuclear Medicine and Molecular Imaging Group, Clinical University
Hospital, IDIS Health Research Institute, 15706 Santiago
de Compostela, Spain
| | - Tomás Sobrino
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Rudi A.J.O. Dierckx
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Aren van Waarde
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Philip H. Elsinga
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Gert Luurtsema
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
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12
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Garcia-Varela L, Attia K, Sembrano JC, Jacquet O, Antunes IF, Kwizera C, Visser TJ, Dierckx RAJO, Elsinga PH, Luurtsema G. A new approach to produce [ 18F]MC225 via one-step synthesis, a PET radiotracer for measuring P-gp function. EJNMMI Radiopharm Chem 2021; 6:24. [PMID: 34264435 PMCID: PMC8282851 DOI: 10.1186/s41181-021-00139-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/11/2021] [Indexed: 11/19/2022] Open
Abstract
Background [18F]MC225 is a radiotracer for imaging P-glycoprotein (P-gp) function at the blood-brain barrier. The P-gp function can be altered due to different factors, for instance, decreased P-gp function has been described in patients with Alzheimer’s or Parkinson’s Disease. The current applied radiosynthesis of [18F]MC225 involves 2 steps, including the distillation of the [18F] fluoroethylbromide intermediate. To develop a more robust synthetic procedure, it is of interest to produce the radiotracer via a 1-step synthesis. The present study describes a new synthetic approach to produce [18F]MC225 via direct 18F-fluorination. Moreover, we also provide the appropriate conditions for the automation of the synthesis. A mesylate precursor was synthesized via a multi-step synthetic route and used for the radiolabeling. The nucleophilic substitution of the mesylate group by [18F] Fluoride was automated in two different synthesis modules: IBA Synthera and Eckert and Ziegler PharmTracer (E&Z). Results The mesylate precursor was synthesized in 7 steps starting with 5-hydroxy-1-tetralone (commercially available) in practical yields. The stability of the precursor was improved via mesylate salt formation method. The radiolabeling was done by adding the mesylate precursor dissolved in DMF to the dried [18F]KF/K2.2.2 complex and heating at 140 °C for 30 min. Quality control by UPLC confirmed the production of [18F]MC225 with a molar activity (Am) higher than 100 GBq/micromole. The synthesis time in Synthera was 106 min and the product was obtained with a radiochemical purity higher than 95% and RCY of 6.5%, while the production in E&Z lasted 120 min and the product had a lower radiochemical purity (91%) and RCY (3.8%). Conclusions [18F]MC225 was successfully produced via a 1-step reaction. The procedure is suitable for automation using commercially available synthesis modules. The automation of the radiosynthesis in the Synthera module allows the production of the [18F]MC225 by a reliable and simple method.
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Affiliation(s)
- Lara Garcia-Varela
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands
| | - Khaled Attia
- Symeres, Kadijk 3, 9747, AT, Groningen, the Netherlands
| | | | | | - Inês F Antunes
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands
| | - Chantal Kwizera
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands
| | - Ton J Visser
- Symeres, Kadijk 3, 9747, AT, Groningen, the Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713, GZ, Groningen, the Netherlands.
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13
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Head-to-head comparison of (R)-[ 11C]verapamil and [ 18F]MC225 in non-human primates, tracers for measuring P-glycoprotein function. Eur J Nucl Med Mol Imaging 2021; 48:4307-4317. [PMID: 34117508 PMCID: PMC8566421 DOI: 10.1007/s00259-021-05411-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/11/2021] [Indexed: 11/03/2022]
Abstract
Purpose P-glycoprotein (P-gp) function is altered in several brain disorders; thus, it is of interest to monitor the P-gp function in vivo using PET. (R)-[11C]verapamil is considered the gold standard tracer to measure the P-gp function; however, it presents some drawbacks that limit its use. New P-gp tracers have been developed with improved properties, such as [18F]MC225. This study compares the characteristics of (R)-[11C]verapamil and [18F]MC225 in the same subjects. Methods Three non-human primates underwent 4 PET scans: 2 with (R)-[11C]verapamil and 2 with [18F]MC225, at baseline and after P-gp inhibition. The 30-min PET data were analyzed using 1-Tissue Compartment Model (1-TCM) and metabolite-corrected plasma as input function. Tracer kinetic parameters at baseline and after inhibition were compared. Regional differences and simplified methods to quantify the P-gp function were also assessed. Results At baseline, [18F]MC225 VT values were higher, and k2 values were lower than those of (R)-[11C]verapamil, whereas K1 values were not significantly different. After inhibition, VT values of the 2 tracers were similar; however, (R)-[11C]verapamil K1 and k2 values were higher than those of [18F]MC225. Significant regional differences between tracers were found at baseline, which disappeared after inhibition. The positive slope of the SUV-TAC was positively correlated to the K1 and VT of both tracers. Conclusion [18F]MC225 and (R)-[11C]verapamil show comparable sensitivity to measure the P-gp function in non-human primates. Moreover, this study highlights the 30-min VT as the best parameter to measure decreases in the P-gp function with both tracers. [18F]MC225 may become the first radiofluorinated tracer able to measure decreases and increases in the P-gp function due to its higher baseline VT. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05411-2.
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14
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García-Varela L, García DV, Kakiuchi T, Ohba H, Nishiyama S, Tago T, Elsinga PH, Tsukada H, Colabufo NA, Dierckx RAJO, van Waarde A, Toyohara J, Boellaard R, Luurtsema G. Pharmacokinetic Modeling of ( R)-[ 11C]verapamil to Measure the P-Glycoprotein Function in Nonhuman Primates. Mol Pharm 2020; 18:416-428. [PMID: 33315404 PMCID: PMC7788571 DOI: 10.1021/acs.molpharmaceut.0c01014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
(R)-[11C]verapamil is a radiotracer
widely used for the evaluation of the P-glycoprotein (P-gp) function
at the blood–brain barrier (BBB). Several studies have evaluated
the pharmacokinetics of (R)-[11C]verapamil
in rats and humans under different conditions. However, to the best
of our knowledge, the pharmacokinetics of (R)-[11C]verapamil have not yet been evaluated in nonhuman primates.
Our study aims to establish (R)-[11C]verapamil
as a reference P-gp tracer for comparison of a newly developed P-gp
positron emission tomography (PET) tracer in a species close to humans.
Therefore, the study assesses the kinetics of (R)-[11C]verapamil and evaluates the effect of scan duration and
P-gp inhibition on estimated pharmacokinetic parameters. Three nonhuman
primates underwent two dynamic 91 min PET scans with arterial blood
sampling, one at baseline and another after inhibition of the P-gp
function. The (R)-[11C]verapamil data
were analyzed using 1-tissue compartment model (1-TCM) and 2-tissue
compartment model fits using plasma-corrected for polar radio-metabolites
or non-corrected for radio-metabolites as an input function and with
various scan durations (10, 20, 30, 60, and 91 min). The preferred
model was chosen according to the Akaike information criterion and
the standard errors (SE %) of the estimated parameters. 1-TCM was
selected as the model of choice to analyze the (R)-[11C]verapamil data at baseline and after inhibition
and for all scan durations tested. The volume of distribution (VT) and the efflux constant k2 estimations were affected by the evaluated scan durations,
whereas the influx constant K1 estimations
remained relatively constant. After P-gp inhibition (tariquidar, 8
mg/kg), in a 91 min scan duration, the whole-brain VT increased significantly up to 208% (p < 0.001) and K1 up to 159% (p < 0.001) compared with baseline scans. The k2 values decreased significantly after P-gp
inhibition in all the scan durations except for the 91 min scans.
This study suggests the use of K1, calculated
with 1-TCM and using short PET scans (10 to 30 min), as a suitable
parameter to measure the P-gp function at the BBB of nonhuman primates.
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Affiliation(s)
- Lara García-Varela
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - David Vállez García
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - Takeharu Kakiuchi
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu 434-8601, Shizuoka, Japan
| | - Hiroyuki Ohba
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu 434-8601, Shizuoka, Japan
| | - Shingo Nishiyama
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu 434-8601, Shizuoka, Japan
| | - Tetsuro Tago
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - Hideo Tsukada
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu 434-8601, Shizuoka, Japan
| | - Nicola A Colabufo
- Department of Pharmacy, University of Bari Aldo Moro, Bari 70125, Italy.,Biofordrug, Spin-off Università degli Studi di Bari "A. Moro", via Dante 99, Triggiano, Bari 70019, Italy
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
| | - Ronald Boellaard
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, The Netherlands
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15
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García-Varela L, Arif WM, Vállez García D, Kakiuchi T, Ohba H, Harada N, Tago T, Elsinga PH, Tsukada H, Colabufo NA, Dierckx RAJO, van Waarde A, Toyohara J, Boellaard R, Luurtsema G. Pharmacokinetic Modeling of [ 18F]MC225 for Quantification of the P-Glycoprotein Function at the Blood-Brain Barrier in Non-Human Primates with PET. Mol Pharm 2020; 17:3477-3486. [PMID: 32787277 PMCID: PMC7482398 DOI: 10.1021/acs.molpharmaceut.0c00514] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
![]()
[18F]MC225 has been developed as a weak substrate of
P-glycoprotein (P-gp) aimed to measure changes in the P-gp function
at the blood–brain barrier with positron emission tomography.
This study evaluates [18F]MC225 kinetics in non-human primates
and investigates the effect of both scan duration and P-gp inhibition.
Three rhesus monkeys underwent two 91-min dynamic scans with blood
sampling at baseline and after P-gp inhibition (8 mg/kg tariquidar).
Data were analyzed using the 1-tissue compartment model (1-TCM) and
2-tissue compartment model (2-TCM) fits using metabolite-corrected
plasma as the input function and for various scan durations (10, 20,
30, 60, and 91 min). The preferred model was chosen according to the
Akaike information criterion and the standard errors (%) of the estimated
parameters. For the 91-min scan duration, the influx constant K1 increased by 40.7% and the volume of distribution
(VT) by 30.4% after P-gp inhibition, while
the efflux constant k2 did not change
significantly. Similar changes were found for all evaluated scan durations. K1 did not depend on scan duration (10 min—K1 = 0.2191 vs 91 min—K1 = 0.2258), while VT and k2 did. A scan duration of 10 min seems sufficient
to properly evaluate the P-gp function using K1 obtained with 1-TCM. For the 91-min scan, VT and K1 can be estimated
with a 2-TCM, and both parameters can be used to assess P-gp function.
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Affiliation(s)
- Lara García-Varela
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Wejdan M Arif
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands.,Department of Radiological Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - David Vállez García
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Takeharu Kakiuchi
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan
| | - Hiroyuki Ohba
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan
| | - Norihiro Harada
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan
| | - Tetsuro Tago
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Hideo Tsukada
- Central Research Laboratory, Hamamatsu Photonics KK, 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan
| | - Nicola Antonio Colabufo
- Department of Pharmacy, University of Bari Aldo Moro, Bari 70121, Italy.,Biofordrug, Spin-off Università degli Studi di Bari "A. Moro", via Dante 99, Triggiano, Bari 70019, Italy
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
| | - Ronald Boellaard
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, Groningen 9713 GZ, the Netherlands
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16
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Focused ultrasound for opening blood-brain barrier and drug delivery monitored with positron emission tomography. J Control Release 2020; 324:303-316. [DOI: 10.1016/j.jconrel.2020.05.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022]
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17
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Toyohara J, Sakata M, Tago T, Colabufo NA, Luurtsema G. Automated synthesis, preclinical toxicity, and radiation dosimetry of [ 18F]MC225 for clinical use: a tracer for measuring P-glycoprotein function at the blood-brain barrier. EJNMMI Res 2020; 10:84. [PMID: 32700099 PMCID: PMC7376787 DOI: 10.1186/s13550-020-00674-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/14/2020] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION [18F]MC225 is a selective substrate for P-glycoprotein (P-gp) that has good metabolic stability and shows higher baseline uptake compared with other P-gp substrates such as (R)-[11C]Verapamil. Prior to clinical translation, it is necessary to perform process validation of the radiosynthesis, assessment of preclinical toxicity, and radiation dosimetry. METHODS The production of [18F]MC225 was automated on a CFN-MPS200 multipurpose synthesizer. The acute toxicity of MC225 was evaluated at a dose of 2.5 mg/kg bodyweight, which is more than 10,000-fold the postulated maximum clinical dose of [18F]MC225. The acute toxicity of [18F]MC225 injection at a 200-fold dose, to administer a postulated dose of 185 MBq of [18F]MC225, was also evaluated after the decay-out of 18F. The mutagenicity of MC225 was studied by a reverse mutation test using Salmonella typhimurium and Escherichia coli (Ames test). In vivo biodistribution and dosimetry studies of [18F]MC225 were carried out in normal mice. Human dosimetry was estimated using OLINDA software. RESULTS The mean decay-corrected yields of [18F]MC225 at end of synthesis were 13%, with > 99% radiochemical purity, > 1000 GBq/μmol molar activity, and ≤ 1.5 μg/185 MBq of total chemical contents. All process validation batches complied with the product specifications and the process was confirmed to be appropriate for the production of [18F]MC225. No acute toxicity of MC225 or [18F]MC225 injection was found. No mutagenic activity was observed for MC225. The biodistribution study demonstrated both hepatobiliary and renal excretion of radioactivity. The most critical organ was the pancreas, with (63.8 μGy/MBq) or without urination (63.9 μGy/MBq) at 360 min after injection. The estimated effective dose (μSv/MBq) with and without urination at 360 min after injection was calculated as 15.7 and 16.9, respectively. CONCLUSION [18F]MC225 shows acceptable pharmacological safety at the dose required for adequate PET imaging. The potential risk associated with [18F]MC225 PET imaging is well within acceptable dose limits.
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Affiliation(s)
- Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Muneyuki Sakata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Tetsuro Tago
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Nicola A. Colabufo
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Bari, Italy
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen and University Medical Centre Groningen, Groningen, The Netherlands
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18
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Zoufal V, Mairinger S, Brackhan M, Krohn M, Filip T, Sauberer M, Stanek J, Wanek T, Tournier N, Bauer M, Pahnke J, Langer O. Imaging P-Glycoprotein Induction at the Blood-Brain Barrier of a β-Amyloidosis Mouse Model with 11C-Metoclopramide PET. J Nucl Med 2020; 61:1050-1057. [PMID: 31806767 PMCID: PMC7383073 DOI: 10.2967/jnumed.119.237198] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/18/2019] [Indexed: 01/30/2023] Open
Abstract
P-glycoprotein (ABC subfamily B member 1, ABCB1) plays an important role at the blood-brain barrier (BBB) in promoting clearance of neurotoxic β-amyloid (Aβ) peptides from the brain into the blood. ABCB1 expression and activity were found to be decreased in the brains of Alzheimer disease patients. Treatment with drugs that induce cerebral ABCB1 activity may be a promising approach to delay the build-up of Aβ deposits in the brain by enhancing clearance of Aβ peptides from the brain. The aim of this study was to investigate whether PET with the weak ABCB1 substrate radiotracer 11C-metoclopramide can measure ABCB1 induction at the BBB in a β-amyloidosis mouse model (APP/PS1-21 mice) and in wild-type mice. Methods: Groups of wild-type and APP/PS1-21 mice aged 50 or 170 d underwent 11C-metoclopramide baseline PET scans or scans after intraperitoneal treatment with the rodent pregnane X receptor activator 5-pregnen-3β-ol-20-one-16α-carbonitrile (PCN, 25 mg/kg) or its vehicle over 7 d. At the end of the PET scans, brains were harvested for immunohistochemical analysis of ABCB1 and Aβ levels. In separate groups of mice, radiolabeled metabolites of 11C-metoclopramide were determined in plasma and brain at 15 min after radiotracer injection. As an outcome parameter of cerebral ABCB1 activity, the elimination slope of radioactivity washout from the brain (kE,brain) was calculated. Results: PCN treatment resulted in an increased clearance of radioactivity from the brain as reflected by significant increases in kE,brain (from +26% to +54% relative to baseline). Immunohistochemical analysis confirmed ABCB1 induction in the brains of PCN-treated APP/PS1-21 mice with a concomitant decrease in Aβ levels. There was a significant positive correlation between kE,brain and ABCB1 levels in the brain. In wild-type mice, a significant age-related decrease in kE,brain was found. Metabolite analysis showed that most radioactivity in the brain comprised unmetabolized 11C-metoclopramide in all animal groups. Conclusion:11C-metoclopramide can measure ABCB1 induction in the mouse brain without the need to consider an arterial input function and may find potential application in Alzheimer disease patients to noninvasively evaluate strategies to enhance the clearance properties of the BBB.
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Affiliation(s)
- Viktoria Zoufal
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Severin Mairinger
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Mirjam Brackhan
- Department of Neuro-/Pathology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Markus Krohn
- Department of Neuro-/Pathology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Thomas Filip
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Michael Sauberer
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Johann Stanek
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Thomas Wanek
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Nicolas Tournier
- UMR 1023 IMIV, Service Hospitalier Frédéric Joliot, CEA, INSERM, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Martin Bauer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Jens Pahnke
- Department of Neuro-/Pathology, University of Oslo and Oslo University Hospital, Oslo, Norway
- LIED, University of Lübeck, Lübeck, Germany
- Leibniz-Institute of Plant Biochemistry, Halle, Germany
- Department of Pharmacology, Medical Faculty, University of Latvia, Rīga, Latvia; and
| | - Oliver Langer
- Preclinical Molecular Imaging, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Division of Nuclear Medicine, Department of Biomedical Imaging und Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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19
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García-Varela L, Vállez García D, Rodríguez-Pérez M, van Waarde A, Sijbesma JWA, Schildt A, Kwizera C, Aguiar P, Sobrino T, Dierckx RAJO, Elsinga PH, Luurtsema G. Test-Retest Repeatability of [ 18F]MC225-PET in Rodents: A Tracer for Imaging of P-gp Function. ACS Chem Neurosci 2020; 11:648-658. [PMID: 31961646 PMCID: PMC7034080 DOI: 10.1021/acschemneuro.9b00682] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
![]()
In
longitudinal PET studies, animals are repeatedly anesthetized
which may affect the repeatability of PET measurements. The aim of
this study was to assess the effect of anesthesia on the P-gp function
as well as the reproducibility of [18F]MC225 PET scans.
Thus, dynamic PET scans with blood sampling were conducted in 13 Wistar
rats. Seven animals were exposed to isoflurane anesthesia 1 week before
the PET scan (“Anesthesia-exposed” PET). A second group
of six animals was used to evaluate the reproducibility of measurements
of P-gp function at the blood–brain barrier (BBB) with [18F]MC225. In this group, two PET scans were made with a 1
week interval (“Test” and “Retest” PET).
Pharmacokinetic parameters were calculated using compartmental models
and metabolite-corrected plasma as an input function. “Anesthesia-exposed”
animals showed a 28% decrease in whole-brain volume of distribution
(VT) (p < 0.001) compared
to “Test”, where the animals were not previously anesthetized.
The VT at “Retest” also
decreased (19%) compared to “Test” (p < 0.001). The k2 values in whole-brain
were significantly increased by 18% in “Anesthesia-exposed”
(p = 0.005) and by 15% in “Retest”
(p = 0.008) compared to “Test”. However,
no significant differences were found in the influx rate constant K1, which is considered as the best parameter
to measure the P-gp function. Moreover, Western Blot analysis did
not find significant differences in the P-gp expression of animals
not pre-exposed to anesthesia (“Test”) or pre-exposed
animals (“Retest”). To conclude, anesthesia may affect
the brain distribution of [18F]MC225 but it does not affect
the P-gp expression or function.
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Affiliation(s)
- Lara García-Varela
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - David Vállez García
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Manuel Rodríguez-Pérez
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15706, Spain
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Jürgen W. A. Sijbesma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Anna Schildt
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Chantal Kwizera
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Pablo Aguiar
- Department of Nuclear Medicine and Molecular Imaging Group, Clinical University Hospital, IDIS Health Research Institute, Santiago de Compostela 15706, Spain
| | - Tomás Sobrino
- Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15706, Spain
| | - Rudi A. J. O. Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Philip H. Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
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20
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High-throughput radio-TLC analysis. Nucl Med Biol 2019; 82-83:41-48. [PMID: 31891883 DOI: 10.1016/j.nucmedbio.2019.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/04/2019] [Accepted: 12/12/2019] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Radio thin layer chromatography (radio-TLC) is commonly used to analyze purity of radiopharmaceuticals or to determine the reaction conversion when optimizing radiosynthesis processes. In applications where there are few radioactive species, radio-TLC is preferred over radio-high-performance liquid chromatography due to its simplicity and relatively quick analysis time. However, with current radio-TLC methods, it remains cumbersome to analyze a large number of samples during reaction optimization. In a couple of studies, Cerenkov luminescence imaging (CLI) has been used for reading radio-TLC plates spotted with a variety of isotopes. We show that this approach can be extended to develop a high-throughput approach for radio-TLC analysis of many samples. METHODS The high-throughput radio-TLC analysis was carried out by performing parallel development of multiple radioactive samples spotted on a single TLC plate, followed by simultaneous readout of the separated samples using Cerenkov imaging. Using custom-written MATLAB software, images were processed and regions of interest (ROIs) were drawn to enclose the radioactive regions/spots. For each sample, the proportion of integrated signal in each ROI was computed. Various crude samples of [18F]fallypride, [18F]FET and [177Lu]Lu-PSMA-617 were prepared for demonstration of this new method. RESULTS Benefiting from a parallel developing process and high resolution of CLI-based readout, total analysis time for eight [18F]fallypride samples was 7.5 min (2.5 min for parallel developing, 5 min for parallel readout), which was significantly shorter than the 48 min needed using conventional approaches (24 min for sequential developing, 24 min for sequential readout on a radio-TLC scanner). The greater separation resolution of CLI enabled the discovery of a low-abundance side product from a crude [18F]FET sample that was not discernable using the radio-TLC scanner. Using the CLI-based readout method, we also observed that high labeling efficiency (99%) of [177Lu]Lu-PSMA-617 can be achieved in just 10 min, rather than the typical 30 min timeframe used. CONCLUSIONS Cerenkov imaging in combination with parallel developing of multiple samples on a single TLC plate proved to be a practical method for rapid, high-throughput radio-TLC analysis.
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21
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Tournier N, Bauer M, Pichler V, Nics L, Klebermass EM, Bamminger K, Matzneller P, Weber M, Karch R, Caillé F, Auvity S, Marie S, Jäger W, Wadsak W, Hacker M, Zeitlinger M, Langer O. Impact of P-Glycoprotein Function on the Brain Kinetics of the Weak Substrate 11C-Metoclopramide Assessed with PET Imaging in Humans. J Nucl Med 2019; 60:985-991. [PMID: 30630940 DOI: 10.2967/jnumed.118.219972] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023] Open
Abstract
PET with avid substrates of P-glycoprotein (ABCB1) provided evidence of the role of this efflux transporter in effectively restricting the brain penetration of its substrates across the human blood-brain barrier (BBB). This may not reflect the situation for weak ABCB1 substrates including several antidepressants, antiepileptic drugs, and neuroleptics, which exert central nervous system effects despite being transported by ABCB1. We performed PET with the weak ABCB1 substrate 11C-metoclopramide in humans to elucidate the impact of ABCB1 function on its brain kinetics. Methods: Ten healthy male subjects underwent 2 consecutive 11C-metoclopramide PET scans without and with ABCB1 inhibition using cyclosporine A (CsA). Pharmacokinetic modeling was performed to estimate the total volume of distribution (V T) and the influx (K 1) and efflux (k 2) rate constants between plasma and selected brain regions. Furthermore, 11C-metoclopramide washout from the brain was estimated by determining the elimination slope (k E,brain) of the brain time-activity curves. Results: In baseline scans, 11C-metoclopramide showed appreciable brain distribution (V T = 2.11 ± 0.33 mL/cm3). During CsA infusion, whole-brain gray matter V T and K 1 were increased by 29% ± 17% and 9% ± 12%, respectively. K 2 was decreased by 15% ± 5%, consistent with a decrease in k E,brain (-32% ± 18%). The impact of CsA on outcome parameters was significant and similar across brain regions except for the pituitary gland, which is not protected by the BBB. Conclusion: Our results show for the first time that ABCB1 does not solely account for the "barrier" property of the BBB but also acts as a detoxifying system to limit the overall brain exposure to its substrates at the human blood-brain interface.
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Affiliation(s)
- Nicolas Tournier
- UMR 1023 IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Martin Bauer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Verena Pichler
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Eva-Maria Klebermass
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Karsten Bamminger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Peter Matzneller
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Maria Weber
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Rudolf Karch
- Centre for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Fabien Caillé
- UMR 1023 IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Sylvain Auvity
- UMR 1023 IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Solène Marie
- UMR 1023 IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Walter Jäger
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.,Center for Biomarker Research in Medicine-CBmed GmbH, Graz, Austria; and
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Oliver Langer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.,Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
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22
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MC225, a Novel Probe for P-glycoprotein PET Imaging at the Blood-brain Barrier: In Vitro Cardiovascular Safety Evaluation. J Cardiovasc Pharmacol 2018; 70:405-410. [PMID: 28877068 DOI: 10.1097/fjc.0000000000000536] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The P-glycoprotein (P-gp) substrate MC225, at concentrations ≤10 nM, is a valuable radiotracer for positron emission tomography imaging of P-gp function in rats and mice. The aim of this study was to evaluate its potential toxic hazard toward the cardiovascular system through an in-depth analysis of its effects on rat aorta rings, on CaV1.2 channel current (ICa1.2) of A7r5 cells and on Langendorff-perfused rat heart. In aortic rings, MC225 relaxed phenylephrine-induced contraction in a concentration-dependent and endothelium-independent manner, with an IC50 value of about 1 μM. At concentrations ≥3 μM, it antagonized the response to cumulative concentrations of K. MC225, 1 and 10 μM, inhibited ICa1.2 by 15% and 31%, respectively, without affecting either current activation or inactivation kinetics. In Langendorff-perfused rat hearts, only 10 μM MC225 significantly decreased left ventricular pressure and increased coronary perfusion pressure while reducing heart rate and prolonging the cardiac cycle length as well as the atrioventricular conduction time (PQ interval) on the electrocardiogram. Lower concentrations of the drug were ineffective. These findings demonstrate that MC225-induced cardiovascular effects took place at concentrations that are at least 2 orders of magnitude higher than those allowing in vivo measurement of P-gp function. Therefore, MC225 represents a promising positron emission tomography tool for in vivo straightforward P-gp quantification.
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23
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Raaphorst RM, Luurtsema G, Schuit RC, Kooijman EJM, Elsinga PH, Lammertsma AA, Windhorst AD. Synthesis and Evaluation of New Fluorine-18 Labeled Verapamil Analogs To Investigate the Function of P-Glycoprotein in the Blood-Brain Barrier. ACS Chem Neurosci 2017; 8:1925-1936. [PMID: 28650628 PMCID: PMC5609126 DOI: 10.1021/acschemneuro.7b00086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/26/2017] [Indexed: 01/19/2023] Open
Abstract
P-glycoprotein is an efflux transporter located in the blood-brain barrier. (R)-[11C]Verapamil is widely used as a PET tracer to investigate its function in patients with epilepsy, Alzheimer's disease, and other neurodegenerative diseases. Currently it is not possible to use this successful tracer in clinics without a cyclotron, because of the short half-life of carbon-11. We developed two new fluorine-18 labeled (R)-verapamil analogs, with the benefit of a longer half-life. The synthesis of (R)-N-[18F]fluoroethylverapamil ([18F]1) and (R)-O-[18F]fluoroethylnorverapamil ([18F]2) has been described. [18F]1 was obtained in reaction of (R)-norverapamil with the volatile [18F]fluoroethyltriflate acquired from bromoethyltosylate and a silver trilate column with a radiochemical yield of 2.7% ± 1.2%. [18F]2 was radiolabeled by direct fluorination of precursor 13 and required final Boc-deprotection with TFA resulting in a radiochemical yield of 17.2% ± 9.9%. Both tracers, [18F]1 and [18F]2, were administered to Wistar rats, and blood plasma and brain samples were analyzed for metabolic stability. Using [18F]1 and [18F]2, PET scans were performed in Wistar rats at baseline and after blocking with tariquidar, showing a 3.6- and 2.4-fold increase in brain uptake in the blocked rats, respectively. In addition, for both [18F]1 and [18F]2, PET scans in Mdr1a/b(-/-), Bcrp1(-/-), and WT mice were acquired, in which [18F]2 showed a more specific brain uptake in Mdr1a/b(-/-) mice and no increased signal in Bcrp1(-/-) mice. [18F]2 was selected as the best performing tracer and should be evaluated further in clinical studies.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/deficiency
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 2/deficiency
- ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics
- Animals
- Blood-Brain Barrier/metabolism
- Central Nervous System Agents/pharmacology
- Drug Evaluation, Preclinical
- Drug Stability
- Male
- Mice, Knockout
- Molecular Structure
- Positron-Emission Tomography
- Quinolines/pharmacology
- Radiopharmaceuticals/chemical synthesis
- Radiopharmaceuticals/pharmacokinetics
- Rats, Wistar
- Tissue Distribution
- Verapamil/chemical synthesis
- Verapamil/pharmacology
- ATP-Binding Cassette Sub-Family B Member 4
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Affiliation(s)
- Renske M. Raaphorst
- Department
of Radiology & Nuclear Medicine, VU
University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Gert Luurtsema
- Department
of Nuclear Medicine and Molecular Imaging, University Medical Center
Groningen, University of Groningen, 9712 CP Groningen, The Netherlands
| | - Robert C. Schuit
- Department
of Radiology & Nuclear Medicine, VU
University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Esther J. M. Kooijman
- Department
of Radiology & Nuclear Medicine, VU
University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Philip H. Elsinga
- Department
of Nuclear Medicine and Molecular Imaging, University Medical Center
Groningen, University of Groningen, 9712 CP Groningen, The Netherlands
| | - Adriaan A. Lammertsma
- Department
of Radiology & Nuclear Medicine, VU
University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Albert D. Windhorst
- Department
of Radiology & Nuclear Medicine, VU
University Medical Center, 1081 HV Amsterdam, The Netherlands
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24
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Raaphorst RM, Savolainen H, Cantore M, van de Steeg E, van Waarde A, Colabufo NA, Elsinga PH, Lammertsma AA, Windhorst AD, Luurtsema G. Comparison of In Vitro Assays in Selecting Radiotracers for In Vivo P-Glycoprotein PET Imaging. Pharmaceuticals (Basel) 2017; 10:ph10030076. [PMID: 29036881 PMCID: PMC5620620 DOI: 10.3390/ph10030076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 12/24/2022] Open
Abstract
Positron emission tomography (PET) imaging of P-glycoprotein (P-gp) in the blood-brain barrier can be important in neurological diseases where P-gp is affected, such as Alzheimer´s disease. Radiotracers used in the imaging studies are present at very small, nanomolar, concentration, whereas in vitro assays where these tracers are characterized, are usually performed at micromolar concentration, causing often discrepant in vivo and in vitro data. We had in vivo rodent PET data of [11C]verapamil, (R)-N-[18F]fluoroethylverapamil, (R)-O-[18F]fluoroethyl-norverapamil, [18F]MC225 and [18F]MC224 and we included also two new molecules [18F]MC198 and [18F]KE64 in this study. To improve the predictive value of in vitro assays, we labeled all the tracers with tritium and performed bidirectional substrate transport assay in MDCKII-MDR1 cells at three different concentrations (0.01, 1 and 50 µM) and also inhibition assay with P-gp inhibitors. As a comparison, we used non-radioactive molecules in transport assay in Caco-2 cells at a concentration of 10 µM and in calcein-AM inhibition assay in MDCKII-MDR1 cells. All the P-gp substrates were transported dose-dependently. At the highest concentration (50 µM), P-gp was saturated in a similar way as after treatment with P-gp inhibitors. Best in vivo correlation was obtained with the bidirectional transport assay at a concentration of 0.01 µM. One micromolar concentration in a transport assay or calcein-AM assay alone is not sufficient for correct in vivo prediction of substrate P-gp PET ligands.
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Affiliation(s)
- Renske M Raaphorst
- Department of Radiology & Nuclear Medicine, VU University Medical Center, De Boelelaan 1085C, 1081 HV Amsterdam, The Netherlands.
| | - Heli Savolainen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
| | - Mariangela Cantore
- Dipartimento di Farmacia-Scienze del Farmaco, Università Degli Studi di Bari, via Orabona 4, 70125 Bari, Italy.
- Biofordrug slr, via Orabona 4, 70125 Bari, Italy.
| | - Evita van de Steeg
- Microbiology Systems and Biology Group, Netherlands Organisation for Applied Scientific Research (TNO), Utrechtseweg 48, 3704 HE Zeist, The Netherlands.
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
| | - Nicola A Colabufo
- Dipartimento di Farmacia-Scienze del Farmaco, Università Degli Studi di Bari, via Orabona 4, 70125 Bari, Italy.
- Biofordrug slr, via Orabona 4, 70125 Bari, Italy.
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, VU University Medical Center, De Boelelaan 1085C, 1081 HV Amsterdam, The Netherlands.
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, VU University Medical Center, De Boelelaan 1085C, 1081 HV Amsterdam, The Netherlands.
| | - Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
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25
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Saidijam M, Karimi Dermani F, Sohrabi S, Patching SG. Efflux proteins at the blood-brain barrier: review and bioinformatics analysis. Xenobiotica 2017; 48:506-532. [PMID: 28481715 DOI: 10.1080/00498254.2017.1328148] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1. Efflux proteins at the blood-brain barrier provide a mechanism for export of waste products of normal metabolism from the brain and help to maintain brain homeostasis. They also prevent entry into the brain of a wide range of potentially harmful compounds such as drugs and xenobiotics. 2. Conversely, efflux proteins also hinder delivery of therapeutic drugs to the brain and central nervous system used to treat brain tumours and neurological disorders. For bypassing efflux proteins, a comprehensive understanding of their structures, functions and molecular mechanisms is necessary, along with new strategies and technologies for delivery of drugs across the blood-brain barrier. 3. We review efflux proteins at the blood-brain barrier, classified as either ATP-binding cassette (ABC) transporters (P-gp, BCRP, MRPs) or solute carrier (SLC) transporters (OATP1A2, OATP1A4, OATP1C1, OATP2B1, OAT3, EAATs, PMAT/hENT4 and MATE1). 4. This includes information about substrate and inhibitor specificity, structural organisation and mechanism, membrane localisation, regulation of expression and activity, effects of diseases and conditions and the principal technique used for in vivo analysis of efflux protein activity: positron emission tomography (PET). 5. We also performed analyses of evolutionary relationships, membrane topologies and amino acid compositions of the proteins, and linked these to structure and function.
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Affiliation(s)
- Massoud Saidijam
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Fatemeh Karimi Dermani
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Sareh Sohrabi
- a Department of Molecular Medicine and Genetics , Research Centre for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences , Hamadan , Iran and
| | - Simon G Patching
- b School of BioMedical Sciences and the Astbury Centre for Structural Molecular Biology, University of Leeds , Leeds , UK
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Astrocytic transporters in Alzheimer's disease. Biochem J 2017; 474:333-355. [DOI: 10.1042/bcj20160505] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/16/2016] [Accepted: 11/29/2016] [Indexed: 12/26/2022]
Abstract
Astrocytes play a fundamental role in maintaining the health and function of the central nervous system. Increasing evidence indicates that astrocytes undergo both cellular and molecular changes at an early stage in neurological diseases, including Alzheimer's disease (AD). These changes may reflect a change from a neuroprotective to a neurotoxic phenotype. Given the lack of current disease-modifying therapies for AD, astrocytes have become an interesting and viable target for therapeutic intervention. The astrocyte transport system covers a diverse array of proteins involved in metabolic support, neurotransmission and synaptic architecture. Therefore, specific targeting of individual transporter families has the potential to suppress neurodegeneration, a characteristic hallmark of AD. A small number of the 400 transporter superfamilies are expressed in astrocytes, with evidence highlighting a fraction of these are implicated in AD. Here, we review the current evidence for six astrocytic transporter subfamilies involved in AD, as reported in both animal and human studies. This review confirms that astrocytes are indeed a viable target, highlights the complexities of studying astrocytes and provides future directives to exploit the potential of astrocytes in tackling AD.
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Savolainen H, Meerlo P, Elsinga PH, Windhorst AD, Dierckx RA, Colabufo NA, van Waarde A, Luurtsema G. P-glycoprotein Function in the Rodent Brain Displays a Daily Rhythm, a Quantitative In Vivo PET Study. AAPS JOURNAL 2016; 18:1524-1531. [DOI: 10.1208/s12248-016-9973-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/08/2016] [Indexed: 12/21/2022]
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