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Liu X, Li F, Wen X, Zheng J, Pan W, Li Z. 18F-Labeled dihydropyridines via Hantzsch reaction for positron emission tomography of P-glycoprotein dysfunction. Bioorg Med Chem Lett 2024; 109:129818. [PMID: 38823726 DOI: 10.1016/j.bmcl.2024.129818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 05/13/2024] [Accepted: 05/27/2024] [Indexed: 06/03/2024]
Abstract
Despite the availability of various 11C-labeled positron emission tomography (PET) tracers for assessing P-glycoprotein (P-gp) function, there are still limitations related to complex metabolism, high lipophilicity, and low baseline uptake. This study aimed to address these issues by exploring a series of customized dihydropyridines (DHPs) with enhanced stability and reduced lipophilicity as alternative PET tracers for P-gp dysfunction. Compared with verapamil and the rest DHPs, dimethyl 4-(4-fluorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1) exhibited superior cellular uptake differences between the human gastric cancer cell line SGC7901 and its drug-resistant counterpart. [18F]1 is successfully synthesized using a novel "hot-Hantzsch" approach in 22.1 ± 0.1 % radiochemical yields. MicroPET/CT imaging demonstrated that the uptake of [18F]1 in the brains of P-gp blocked mice increased by > 3 times compared to the control group. Additionally, [18F]1 displayed favorable lipophilicity (log D = 2.3) and excellent clearance characteristics, making it a promising tracer candidate with low background noise and high contrast.
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Affiliation(s)
- Xia Liu
- State Key Laboratory of Vaccines for Infectious Diseases, Center for Molecular Imaging and Translational Medicine, Xiang An Biomedicine Laboratory, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen, Fujian 361102, China
| | - Feng Li
- Department of Radiology, Hainan Women and Children's Medical Center, Haikou, Hainan 570206, China
| | - Xing Wen
- Department of Ultrasound, Chengdu Fifth People's Hospital, Chengdu, Sichuan 611130, China
| | - Jiamei Zheng
- State Key Laboratory of Vaccines for Infectious Diseases, Center for Molecular Imaging and Translational Medicine, Xiang An Biomedicine Laboratory, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen, Fujian 361102, China
| | - Weimin Pan
- Department of Nuclear Medicine, Xiang'an Hospital of Xiamen University, Xiamen, Fujian 361102, China; Department of Nuclear Medicine, Quanzhou First Hospital, Quanzhou, Fujian 362002, China.
| | - Zijing Li
- State Key Laboratory of Vaccines for Infectious Diseases, Center for Molecular Imaging and Translational Medicine, Xiang An Biomedicine Laboratory, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, Xiamen University, Xiamen, Fujian 361102, China.
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Abstract
The blood-brain barrier (BBB) is a critical interface separating the central nervous system from the peripheral circulation, ensuring brain homeostasis and function. Recent research has unveiled a profound connection between the BBB and circadian rhythms, the endogenous oscillations synchronizing biological processes with the 24-hour light-dark cycle. This review explores the significance of circadian rhythms in the context of BBB functions, with an emphasis on substrate passage through the BBB. Our discussion includes efflux transporters and the molecular timing mechanisms that regulate their activities. A significant focus of this review is the potential implications of chronotherapy, leveraging our knowledge of circadian rhythms for improving drug delivery to the brain. Understanding the temporal changes in BBB can lead to optimized timing of drug administration, to enhance therapeutic efficacy for neurological disorders while reducing side effects. By elucidating the interplay between circadian rhythms and drug transport across the BBB, this review offers insights into innovative therapeutic interventions.
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Affiliation(s)
- Mari Kim
- Cell Biology Department, Emory University, Atlanta, GA, USA (M.K., S.L.Z.)
| | - Richard F Keep
- Neurosurgery, University of Michigan, Ann Arbor, MI, USA (R.F.K.)
| | - Shirley L Zhang
- Cell Biology Department, Emory University, Atlanta, GA, USA (M.K., S.L.Z.)
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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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Synergistic Effects of Ginsenoside Rb3 and Ferruginol in Ischemia-Induced Myocardial Infarction. Int J Mol Sci 2022; 23:ijms232415935. [PMID: 36555577 PMCID: PMC9785845 DOI: 10.3390/ijms232415935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/01/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Previous research shows that ginsenoside Rb3 (G-Rb3) exhibit significant protective effects on cardiomyocytes and is considered a promising treatment for myocardial infraction (MI). However, how to improve its oral bioavailability and reduce its dosage remains to be studied. Previous studies suggest that Ferruginol (FGL) may have synergistic effects with G-Rb3. However, the underlying mechanisms remain to be explored. In this study, left anterior descending branch (LAD) coronary artery ligation or oxygen-glucose deprivation-reperfusion (OGD/R) were used to establish MI models in vivo and in vitro. Subsequently, the pharmacological effects and mechanisms of G-Rb3-FGL were explored by in vitro studies. The results showed that the G-Rb3-FGL co-treatment improved heart functions better than the G-Rb3 treatment alone in MI mice models. Meanwhile, the G-Rb3-FGL co-treatment can upregulate fatty acids oxidation (FAO) and suppress oxidative stress in the heart tissues of MI mice. In vitro studies demonstrated that the synergistic effect of G-Rb3-FGL on FAO, oxidation and inflammation was abolished by RXRα inhibitor HX531 in the H9C2 cell model. In summary, we revealed that G-Rb3 and FGL have a synergistic effect against MI. They protected cardiomyocytes by promoting FAO, inhibiting oxidative stress, and suppressing inflammation through the RXRα-Nrf2 signaling pathway.
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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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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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