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Abreu Diaz AM, Rodriguez Riera Z, Lee Y, Esteves LM, Normandeau CO, Fezas B, Hernandez Saiz A, Tournoux F, Juneau D, DaSilva JN. [ 18 F]Fluoropyridine-losartan: A new approach toward human Positron Emission Tomography imaging of Angiotensin II Type 1 receptors. J Labelled Comp Radiopharm 2023; 66:73-85. [PMID: 36656923 DOI: 10.1002/jlcr.4014] [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: 11/13/2022] [Revised: 12/27/2022] [Accepted: 01/17/2023] [Indexed: 01/21/2023]
Abstract
Angiotensin II type 1 receptors (AT1 R) blocker losartan is used in patients with renal and cardiovascular diseases. [18 F]fluoropyridine-losartan has shown favorable binding profile for quantitative renal PET imaging of AT1 R with selective binding in rats and pigs, low interference of radiometabolites and appropriate dosimetry for clinical translation. A new approach was developed to produce [18 F]fluoropyridine-losartan in very high molar activity. Automated radiosynthesis was performed in a three-step, two-pot, and two-HPLC-purification procedure within 2 h. Pure [18 F]FPyKYNE was obtained by radiofluorination of NO2 PyKYNE and silica-gel-HPLC purification (40 ± 9%), preventing the formation of nitropyridine-losartan in the second step. Conjugation with trityl-losartan azide via click chemistry, followed by acid hydrolysis, C18-HPLC purification and reformulation provided [18 F]fluoropyridine-losartan in 11 ± 2% (decay-corrected from [18 F]fluoride, EOB). Using tris[(1-(3-hydroxypropyl)-1H-1,2,3-triazol-4-yl)methyl]-amine (THPTA) as a Cu(I)-stabilizing agent for coupling [18 F]FPyKYNE to the unprotected losartan azide afforded [18 F]fluoropyridine-losartan in similar yields (11 ± 3%, decay-corrected from [18 F]fluoride, EOB). Reverse-phase HPLC was optimized by reducing the pH of the mobile phase to achieve complete purification and high molar activities (467 ± 60 GBq/μmol). The use of radioprotectants prevented tracer radiolysis for 10 h (RCP > 99%). The product passed the quality control testing. This reproducible automated radiosynthesis process will allow in vivo PET imaging of AT1 R expression in several diseases.
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Affiliation(s)
- Aida Mary Abreu Diaz
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Pavillon Paul-G. Desmarais, Montréal, Québec, Canada
- Institut de génie biomédical, Faculté de médecine, Université de Montréal, Pavillon Paul-G. Desmarais, Montréal, Québec, Canada
- Departamento de Radioquímica, Instituto Superior de Tecnologías y Ciencias Aplicadas, Universidad de la Habana, La Habana, Cuba
| | - Zalua Rodriguez Riera
- Departamento de Radioquímica, Instituto Superior de Tecnologías y Ciencias Aplicadas, Universidad de la Habana, La Habana, Cuba
| | - Yanick Lee
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- Institut de génie biomédical, Faculté de médecine, Université de Montréal, Pavillon Paul-G. Desmarais, Montréal, Québec, Canada
| | - Luis Miguel Esteves
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- CRCHUM site, Isologic Innovative Radiopharmaceuticals, Lachine, Québec, Canada
| | | | - Baptiste Fezas
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
| | | | - François Tournoux
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- Centre cardiovasculaire, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Daniel Juneau
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- Médecine nucléaire, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
- Département de radiologie, radio-oncologie et médecine nucléaire, Faculté de médecine, Université de Montréal, Pavillon Roger-Gaudry, Montréal, Québec, Canada
| | - Jean N DaSilva
- Laboratoire de Radiochimie et Cyclotron, Centre de Recherche du CHUM, Montréal, Québec, Canada
- Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Pavillon Paul-G. Desmarais, Montréal, Québec, Canada
- Institut de génie biomédical, Faculté de médecine, Université de Montréal, Pavillon Paul-G. Desmarais, Montréal, Québec, Canada
- Département de radiologie, radio-oncologie et médecine nucléaire, Faculté de médecine, Université de Montréal, Pavillon Roger-Gaudry, Montréal, Québec, Canada
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Juengling FD, Maldonado A, Wuest F, Schindler TH. Identify. Quantify. Predict. Why Immunologists Should Widely Use Molecular Imaging for Coronavirus Disease 2019. Front Immunol 2021; 12:568959. [PMID: 34054793 PMCID: PMC8155634 DOI: 10.3389/fimmu.2021.568959] [Citation(s) in RCA: 3] [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: 06/02/2020] [Accepted: 04/16/2021] [Indexed: 01/18/2023] Open
Abstract
Molecular imaging using PET/CT or PET/MRI has evolved from an experimental imaging modality at its inception in 1972 to an integral component of diagnostic procedures in oncology, and, to lesser extent, in cardiology and neurology, by successfully offering in-vivo imaging and quantitation of key pathophysiological targets or molecular signatures, such as glucose metabolism in cancerous disease. Apart from metabolism probes, novel radiolabeled peptide and antibody PET tracers, including radiolabeled monoclonal antibodies (mAbs) have entered the clinical arena, providing the in-vivo capability to collect target-specific quantitative in-vivo data on cellular and molecular pathomechanisms on a whole-body scale, and eventually, extract imaging biomarkers possibly serving as prognostic indicators. The success of molecular imaging in mapping disease severity on a whole-body scale, and directing targeted therapies in oncology possibly could translate to the management of Coronavirus Disease 2019 (COVID-19), by identifying, localizing, and quantifying involvement of different immune mediated responses to the infection with SARS-COV2 during the course of acute infection and possible, chronic courses with long-term effects on specific organs. The authors summarize current knowledge for medical imaging in COVID-19 in general with a focus on molecular imaging technology and provide a perspective for immunologists interested in molecular imaging research using validated and immediately available molecular probes, as well as possible future targets, highlighting key targets for tailored treatment approaches as brought up by key opinion leaders.
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Affiliation(s)
- Freimut D. Juengling
- Medical Faculty, University Bern, Bern, Switzerland
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Antonio Maldonado
- Department of Nuclear Medicine and Molecular Imaging, Quironsalud Madrid University Hospital, Madrid, Spain
| | - Frank Wuest
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Thomas H. Schindler
- Mallinckrodt Institute of Radiology, Division of Nuclear Medicine, Washington University School of Medicine, Saint Louis, MO, United States
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Abreu Diaz AM, Drumeva GO, Laporte P, Alonso Martinez LM, Petrenyov DR, Carrier JF, DaSilva JN. Evaluation of the high affinity [ 18F]fluoropyridine-candesartan in rats for PET imaging of renal AT 1 receptors. Nucl Med Biol 2021; 96-97:41-49. [PMID: 33798796 DOI: 10.1016/j.nucmedbio.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Alterations in the expression of the Angiotensin II type 1 receptors (AT1R) have been demonstrated in the development of several heart and renal diseases. The aim of this study was to evaluate the novel compound [18F]fluoropyridine-candesartan as a PET imaging tracer of AT1R in rat kidneys. METHODS Competition binding assays were carried out with membranes from CHO-K1 cells expressing human AT1R. Binding to plasma proteins was assessed by ultrafiltration. Radiolabeled metabolites in rat plasma and kidneys of control and pretreated animals (candesartan 10 mg/kg or losartan 30 mg/kg) were analyzed by column-switch HPLC. Dynamic PET/CT images of [18F]fluoropyridine-candesartan in male Sprague-Dawley rats were acquired for 60 min at baseline, pre-treatment with the AT1R antagonist losartan (30 mg/kg) or the AT2R antagonist PD123,319 (5 mg/kg). RESULTS Fluoropyridine-candesartan bound with a high affinity for AT1R (Ki = 5.9 ± 1.1 nM), comparable to fluoropyridine-losartan but lower than the parent compound candesartan (Ki = 0.4 ± 0.1 nM). [18F]Fluoropyridine-candesartan bound strongly to plasma proteins (99.3%) and was mainly metabolized to radiolabeled hydrophilic compounds, displaying minimal interference on renal AT1R binding with 82% of unchanged tracer in the kidneys at 20 min post-injection. PET imaging displayed high renal and liver accumulations and slow clearances, with maximum tissue-to-blood ratios of 14 ± 3 and 54 ± 12 in kidney cortex and liver, respectively, at 10 min post-injection. Binding specificity for AT1R was demonstrated with marked reductions in kidney cortex (-84%) and liver (-93%) tissue-to-blood ratios at 20 min post-injection, when blocking with AT1R antagonist losartan (30 mg/kg). No change was observed in kidney cortex of rats pre-treated with AT2R antagonist PD 123,319 (5 mg/kg), confirming binding selectivity for AT1 over AT2 receptors. CONCLUSION High kidney-to-blood ratios and binding selectivity to renal AT1R combined with tracer in vivo stability displaying minimal interference from labeled metabolites support further PET imaging studies with [18F]fluoropyridine-candesartan.
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Affiliation(s)
- Aida M Abreu Diaz
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Institute de génie biomédical, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Departamento de Radioquímica, Instituto Superior de Tecnologías y Ciencias Aplicadas, Universidad de la Habana, La Habana, Cuba
| | - Gergana O Drumeva
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Philippe Laporte
- Institute de génie biomédical, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Département de physique, Faculté des arts et des sciences, Université de Montréal, Montréal, Québec, Canada
| | - Luis M Alonso Martinez
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Institute de génie biomédical, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Daniil R Petrenyov
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Jean-François Carrier
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Institute de génie biomédical, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Département de physique, Faculté des arts et des sciences, Université de Montréal, Montréal, Québec, Canada; Département de radiologie, radio-oncologie et médecine nucléaire, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Jean N DaSilva
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de pharmacologie et physiologie, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Institute de génie biomédical, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada; Département de radiologie, radio-oncologie et médecine nucléaire, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada.
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Abreu Diaz AM, Drumeva GO, Petrenyov DR, Carrier JF, DaSilva JN. Synthesis of the Novel AT 1 Receptor Tracer [ 18F]Fluoropyridine-Candesartan via Click Chemistry. ACS OMEGA 2020; 5:20353-20362. [PMID: 32832788 PMCID: PMC7439361 DOI: 10.1021/acsomega.0c02310] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
A novel 7-((4-(3-((2-[18F]fluoropyridin-3-yl)oxy)propyl)-1H-1,2,3-triazol-1-yl)methyl)-1H-benzo[d]imidazole derivative of the angiotensin II type-1 receptor (AT1R) blocker candesartan, [18F]fluoropyridine-candesartan, was synthesized via the copper-catalyzed azide-alkyne cycloaddition click reaction between 2-[18F]fluoro-3-(pent-4-yn-1-yloxy)pyridine ([18F]FPyKYNE) and the tetrazole-protected azido-candesartan derivative, followed by acid deprotection. This three-step, two-pot, and two-step purification synthesis was done within 2 h. The use of tris[(1-hydroxypropyl-1H-1,2,3-triazol-4-yl)methyl]amine (THPTA) as a Cu(I) stabilizing agent increased the overall radiochemical yield by 4-fold (10 ± 2%, n = 13) compared to the reaction without THPTA (2.4 ± 0.2%, n = 3; decay-corrected from 18F produced at the end-of-beam). Complete separation of [18F]FPyKYNE from its nitro precursor and [18F]fluoropyridine-candesartan from the deprotected azido-candesartan allowed for high molar activities (>380 GBq/μmol) of the tracer. The use of 0.1% trifluoroacetic acid in water for reformulation and the addition of sodium ascorbate to the final formulation (1.6 ± 0.2 GBq/mL, n = 3) prevented tracer radiolysis with >97% radiochemical purity for a period of up to 10 h after the end-of-synthesis. A significant reduction in the uptake (86 ± 3%, n = 8) of the tracer was observed ex vivo in rats (at 20 min postinjection) in the AT1R-rich kidney cortex following pretreatment with saturating doses of the AT1R antagonist candesartan or losartan. This specific binding to AT1R was confirmed in vitro in the rat renal cortex (autoradiography) by a reduction of 26 ± 5% (n = 12) with losartan coincubation (10 μM). These favorable binding properties support further studies to assess the potential of [18F]fluoropyridine-candesartan as a tracer for the positron emission tomography imaging of renal AT1R.
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Affiliation(s)
- Aida M. Abreu Diaz
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Departamento
de Radioquímica, Instituto Superior de Tecnologías y
Ciencias Aplicadas, Universidad de la Habana, Ave. Salvador Allende y Luaces,
Quinta de los Molinos, La Habana 10400, Cuba
| | - Gergana O. Drumeva
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
| | - Daniil R. Petrenyov
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
| | - Jean-François Carrier
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Département
de Physique, Faculté des Arts et des Sciences, Université de Montréal, Complexe des Sciences, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada
- Département
de Radiologie, Radio-Oncologie et Médecine Nucléaire,
Faculté de Médecine, Université
de Montréal, Pavillon
Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - Jean N. DaSilva
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Département
de Radiologie, Radio-Oncologie et Médecine Nucléaire,
Faculté de Médecine, Université
de Montréal, Pavillon
Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
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Synthesis and Evaluation of [ 18F]FEtLos and [ 18F]AMBF 3Los as Novel 18F-Labelled Losartan Derivatives for Molecular Imaging of Angiotensin II Type 1 Receptors. Molecules 2020; 25:molecules25081872. [PMID: 32325695 PMCID: PMC7221519 DOI: 10.3390/molecules25081872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/18/2020] [Accepted: 01/23/2020] [Indexed: 01/13/2023] Open
Abstract
Losartan is widely used in clinics to treat cardiovascular related diseases by selectively blocking the angiotensin II type 1 receptors (AT1Rs), which regulate the renin-angiotensin system (RAS). Therefore, monitoring the physiological and pathological biodistribution of AT1R using positron emission tomography (PET) might be a valuable tool to assess the functionality of RAS. Herein, we describe the synthesis and characterization of two novel losartan derivatives PET tracers, [18F]fluoroethyl-losartan ([18F]FEtLos) and [18F]ammoniomethyltrifluoroborate-losartan ([18F]AMBF3Los). [18F]FEtLos was radiolabeled by 18F-fluoroalkylation of losartan potassium using the prosthetic group 2-[18F]fluoroethyl tosylate; whereas [18F]AMBF3Los was prepared following an one-step 18F-19F isotopic exchange reaction, in an overall yield of 2.7 ± 0.9% and 11 ± 4%, respectively, with high radiochemical purity (>95%). Binding competition assays in AT1R-expressing membranes showed that AMBF3Los presented an almost equivalent binding affinity (Ki 7.9 nM) as the cold reference Losartan (Ki 1.5 nM), unlike FEtLos (Ki 2000 nM). In vitro and in vivo assays showed that [18F]AMBF3Los displayed a good binding affinity for AT1R-overexpressing CHO cells and was able to specifically bind to renal AT1R. Hence, our data demonstrate [18F]AMBF3Los as a new tool for PET imaging of AT1R with possible applications for the diagnosis of cardiovascular, inflammatory and cancer diseases.
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Hanssen O, Lovinfosse P, Weekers L, Hustinx R, Jouret F. [ 18F-FDG positron emission tomography in non-oncological renal pathology: Current indications and perspectives]. Nephrol Ther 2019; 15:430-438. [PMID: 30982747 DOI: 10.1016/j.nephro.2018.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 11/28/2018] [Indexed: 12/26/2022]
Abstract
Positron emission tomography combined with computed tomography (PET/CT) is a nuclear imaging technique which provides anatomical and functional information. PET/CT is increasingly used in non-oncological nephrology since conventional radiological approaches after injection of contrast agents are relatively contra-indicated in patients with chronic kidney disease (CKD). PET/CT after i.v. injection of 18F-fluoro-deoxy-glucose (FDG) is not toxic and is characterized by a high sensitivity. The level of irradiation (∼5mSv) is acceptable. CKD does not significantly influence tissue uptake of 18F-FDG. The purpose of the present review aims at detailing the non-oncological indications of 18F-FDG PET/CT in general nephrology and after kidney transplantation. Particularly, 18F-FDG PET/CT appears useful in the diagnosis of cyst infection in patients with autosomal dominant polycystic kidney disease, as well as in the characterization of retroperitoneal fibrosis. In kidney transplant recipients, 18F-FDG PET/CT may help in the diagnostic work-up of suspected acute rejection, thereby eventually avoiding unnecessary kidney transplant biopsy. Perspectives in 18F-FDG PET/CT imaging are discussed, including innovative approaches of image analysis.
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Affiliation(s)
- Oriane Hanssen
- Service de néphrologie, centre hospitalier universitaire de Liège, avenue Hippocrate 13, 4000 Liège, Belgique
| | - Pierre Lovinfosse
- Service de médecine nucléaire et imagerie oncologique, centre hospitalier universitaire de Liège, avenue Hippocrate 13, 4000 Liège, Belgique
| | - Laurent Weekers
- Service de médecine nucléaire et imagerie oncologique, centre hospitalier universitaire de Liège, avenue Hippocrate 13, 4000 Liège, Belgique
| | - Roland Hustinx
- Service de médecine nucléaire et imagerie oncologique, centre hospitalier universitaire de Liège, avenue Hippocrate 13, 4000 Liège, Belgique
| | - François Jouret
- Service de néphrologie, centre hospitalier universitaire de Liège, avenue Hippocrate 13, 4000 Liège, Belgique; Groupe interdisciplinaire de géno-protéomique appliquée (GIGA), sciences cardiovasculaires, université de Liège, Liège, Belgique.
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Synthesis and Evaluation of 18F-Labeled Peptide for Gonadotropin-Releasing Hormone Receptor Imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2019; 2019:5635269. [PMID: 30983920 PMCID: PMC6431521 DOI: 10.1155/2019/5635269] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/23/2019] [Accepted: 01/29/2019] [Indexed: 12/13/2022]
Abstract
The gonadotropin-releasing hormone (GnRH) receptor is overexpressed in the majority of tumors of the human reproductive system. The purpose of this study was to develop an 18F-labeled peptide for tumor GnRH receptor imaging. In this study, the GnRH (pGlu1-His2-Trp3-Ser4-Tyr5-Gly6-Leu7-Arg8-Pro9-Gly10-NH2) peptide analogues FP-d-Lys6-GnRH (FP = 2-fluoropropanoyl) and NOTA-P-d-Lys6-GnRH (P = ethylene glycol) were designed and synthesized. The IC50 values of FP-d-Lys6-GnRH and NOTA-P-d-Lys6-GnRH were 2.0 nM and 56.2 nM, respectively. 4-Nitrophenyl-2-[18F]fluoropropionate was conjugated to the ε-amino group of the d-lysine side chain of d-Lys6-GnRH to yield the new tracer [18F]FP-d-Lys6-GnRH with a decay-corrected yield of 8 ± 3% and a specific activity of 20−100 GBq/µmol (n=6). Cell uptake studies of [18F]FP-d-Lys6-GnRH in GnRH receptor-positive PC-3 cells and GnRH receptor-negative CHO-K1 cells indicated receptor-specific accumulation. Biodistribution and PET studies in nude mice bearing PC-3 xenografted tumors showed that [18F]FP-d-Lys6-GnRH was localized in tumors with a higher uptake than in surrounding muscle and heart tissues. Furthermore, the metabolic stability of [18F]FP-d-Lys6-GnRH was determined in mouse blood and PC-3 tumor homogenates at 1 h after tracer injection. The presented results indicated a potential of the novel tracer [18F]FP-d-Lys6-GnRH for tumor GnRH receptor imaging.
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Hoffmann M, Chen X, Hirano M, Arimitsu K, Kimura H, Higuchi T, Decker M. 18
F‐Labeled Derivatives of Irbesartan for Angiotensin II Receptor PET Imaging. ChemMedChem 2018; 13:2546-2557. [DOI: 10.1002/cmdc.201800638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Matthias Hoffmann
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| | - Xinyu Chen
- Department of Nuclear Medicine and Comprehensive Heart Failure Centre (CHFC)University Hospital of Würzburg Oberdürrbacherstr. 6 97080 Würzburg Germany
| | - Mitsuru Hirano
- Department of Bio-Medical ImagingNational Cerebral and Cardiovascular Centre, 5–7-1 Fujishiro-dai Suita Osaka 565-8565 Japan
| | - Kenji Arimitsu
- Department of Analytical and Bioinorganic ChemistryKyoto Pharmaceutical University 5 Nakauchi-Cho, Misasagi Yamashina-ku Kyoto 607–8414 Japan
| | - Hiroyuki Kimura
- Department of Analytical and Bioinorganic ChemistryKyoto Pharmaceutical University 5 Nakauchi-Cho, Misasagi Yamashina-ku Kyoto 607–8414 Japan
| | - Takahiro Higuchi
- Department of Nuclear Medicine and Comprehensive Heart Failure Centre (CHFC)University Hospital of Würzburg Oberdürrbacherstr. 6 97080 Würzburg Germany
- Department of Bio-Medical ImagingNational Cerebral and Cardiovascular Centre, 5–7-1 Fujishiro-dai Suita Osaka 565-8565 Japan
| | - Michael Decker
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
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Chen X, Hirano M, Werner RA, Decker M, Higuchi T. Novel 18F-Labeled PET Imaging Agent FV45 Targeting the Renin-Angiotensin System. ACS OMEGA 2018; 3:10460-10470. [PMID: 30288456 PMCID: PMC6166228 DOI: 10.1021/acsomega.8b01885] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
Renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure and hormonal balance. Using positron emission tomography (PET) technology, it is possible to monitor the physiological and pathological distribution of angiotensin II type 1 receptors (AT1), which reflects the functionality of RAS. A new 18F-labeled PET tracer derived from the clinically used AT1 antagonist valsartan showing the least possible chemical alteration from the valsartan structure has been designed and synthesized with several strategies, which can be applied for the syntheses of further derivatives. Radioligand binding study showed that the cold reference FV45 (K i 14.6 nM) has almost equivalent binding affinity as its lead valsartan (K i 11.8 nM) and angiotensin II (K i 1.7 nM). Successful radiolabeling of FV45 in a one-pot radiofluorination followed by the deprotection procedure with 21.8 ± 8.5% radiochemical yield and >99% radiochemical purity (n = 5) enabled a distribution study in rats and opened a path to straightforward large-scale production. A fast and clear kidney uptake could be observed, and this renal uptake could be selectively blocked by pretreatment with AT1-selective antagonist valsartan. Overall, as the first 18F-labeled PET tracer based on a derivation from clinically used drug valsartan with almost identical chemical structure, [18F]FV45 will be a new tool for assessing the RAS function by visualizing AT1 receptor distributions and providing further information regarding cardiovascular system malfunction as well as possible applications in inflammation research and cancer diagnosis.
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Affiliation(s)
- Xinyu Chen
- Department
of Nuclear Medicine, Comprehensive Heart Failure Center, University
Hospital of Würzburg, Würzburg 97080, Germany
| | - Mitsuru Hirano
- Department
of Bio-Medical Imaging, National Cerebral
and Cardiovascular Center, Osaka 565-0873, Japan
| | - Rudolf A. Werner
- Department
of Nuclear Medicine, Comprehensive Heart Failure Center, University
Hospital of Würzburg, Würzburg 97080, Germany
- The
Russell H. Morgan Department of Radiology and Radiological Science,
Division of Nuclear Medicine and Molecular Imaging, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Michael Decker
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Würzburg 97074, Germany
| | - Takahiro Higuchi
- Department
of Nuclear Medicine, Comprehensive Heart Failure Center, University
Hospital of Würzburg, Würzburg 97080, Germany
- Department
of Bio-Medical Imaging, National Cerebral
and Cardiovascular Center, Osaka 565-0873, Japan
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Ismail B, deKemp RA, Croteau E, Hadizad T, Burns KD, Beanlands RS, DaSilva JN. Treatment with enalapril and not diltiazem ameliorated progression of chronic kidney disease in rats, and normalized renal AT1 receptor expression as measured with PET imaging. PLoS One 2017; 12:e0177451. [PMID: 28542215 PMCID: PMC5438116 DOI: 10.1371/journal.pone.0177451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 04/27/2017] [Indexed: 12/23/2022] Open
Abstract
ACE inhibitors are considered first line of treatment in patients with many forms of chronic kidney disease (CKD). Other antihypertensives such as calcium channel blockers achieve similar therapeutic effectiveness in attenuating hypertension-related renal damage progression. Our objective was to explore the value of positron emission tomography (PET) imaging of renal AT1 receptor (AT1R) to guide therapy in the 5/6 subtotal-nephrectomy (Nx) rat model of CKD. Ten weeks after Nx, Sprague-Dawley rats were administered 10mg/kg/d enalapril (NxE), 30mg/kg/d diltiazem (NxD) or left untreated (Nx) for an additional 8-10 weeks. Kidney AT1R expression was assessed using in vivo [18F]fluoropyridine-losartan PET and in vitro autoradiography. Compared to shams, Nx rats exhibited higher systolic blood pressure that was reduced by both enalapril and diltiazem. At 18-20 weeks, plasma creatinine and albuminuria were significantly increased in Nx, reduced to sham levels in NxE, but enhanced in NxD rats. Enalapril treatment decreased kidney angiotensin II whereas diltiazem induced significant elevations in plasma and kidney levels. Reduced PET renal AT1R levels in Nx were normalized by enalapril but not diltiazem, and results were supported by autoradiography. Reduction of renal blood flow in Nx was restored by enalapril, while no difference was observed in myocardial blood flow amongst groups. Enhanced left ventricle mass in Nx was not reversed by enalapril but was augmented with diltiazem. Stroke volume was diminished in untreated Nx compared to shams and restored with both therapies. [18F]Fluoropyridine-Losartan PET allowed in vivo quantification of kidney AT1R changes associated with progression of CKD and with various pharmacotherapies.
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Affiliation(s)
- Basma Ismail
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Rob A. deKemp
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Etienne Croteau
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Tayebeh Hadizad
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Kevin D. Burns
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ontario, Canada
| | - Rob S. Beanlands
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jean N. DaSilva
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal; University of Montreal Hospital Research Centre (CRCHUM), Montréal, Québec, Canada
- * E-mail:
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11
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Ismail B, deKemp RA, Hadizad T, Mackasey K, Beanlands RS, DaSilva JN. Decreased renal AT1 receptor binding in rats after subtotal nephrectomy: PET study with [(18)F]FPyKYNE-losartan. EJNMMI Res 2016; 6:55. [PMID: 27339045 PMCID: PMC4919198 DOI: 10.1186/s13550-016-0209-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/14/2016] [Indexed: 01/13/2023] Open
Abstract
Background Significant renal mass reduction induced by 5/6 subtotal nephrectomy (Nx) is associated with a chain of events that culminates in hypertension and chronic kidney disease (CKD). Numerous studies have provided evidence for the role of angiotensin (Ang) II type 1 receptor (AT1R) in the promotion and progression of the disease; however, conflicting results were reported on intrarenal AT1R levels in CKD models. Methods Male Sprague-Dawley rats (n = 26) underwent Nx or sham operations. Animals were scanned at 8–10 weeks post-surgery with PET using the novel AT1R radioligand [18F]FPyKYNE-losartan. Radioligand binding was quantified by kidney-to-blood ratio (KBR), standard uptake value (SUV), and distribution volume (DV). After sacrifice, plasma and kidney Ang II levels were measured. Western blot and 125I-[Sar1, Ile8]Ang II autoradiography were performed to assess AT1R expression. Results At 8–10 weeks post-surgery, Nx rats developed hypertension, elevated plasma creatinine levels, left ventricle hypertrophy, increased myocardial blood flow (MBF), and reduced Ang II levels compared to shams. PET measurements displayed significant decrease in KBR (29 %), SUV (24 %), and DV (22 %) induced by Nx (p < 0.05), and these findings were confirmed by in vitro assays. Conclusions Reduced renal AT1Rs in hypertensive rats measured with [18F]FPyKYNE-losartan PET at 8–10 weeks following Nx support further use of this non-invasive approach in longitudinal studies to better understand the AT1R role in CKD progression.
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Affiliation(s)
- Basma Ismail
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada
| | - Robert A deKemp
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada
| | - Tayebeh Hadizad
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada
| | - Kumiko Mackasey
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada
| | - Rob S Beanlands
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada
| | - Jean N DaSilva
- National Cardiac PET Centre, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, K1Y 4W7, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada. .,Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, University of Montreal Hospital Research Centre (CRCHUM), 900 Rue Saint-Denis, Montréal, Québec, H2X 0A9, Canada.
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