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Aarnio R, Kirjavainen A, Rajander J, Forsback S, Kalliokoski K, Nuutila P, Milicevic Z, Coskun T, Haupt A, Laitinen I, Haaparanta-Solin M. New improved radiometabolite analysis method for [ 18F]FTHA from human plasma: a test-retest study with postprandial and fasting state. EJNMMI Res 2024; 14:53. [PMID: 38869780 DOI: 10.1186/s13550-024-01114-5] [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: 04/25/2024] [Accepted: 05/28/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND Fatty acid uptake can be measured using PET and 14-(R,S)-[18F]fluoro-6-thia-heptadecanoic acid ([18F]FTHA). However, the relatively rapid rate of [18F]FTHA metabolism significantly affects kinetic modeling of tissue uptake. Thus, there is a need for accurate chromatographic methods to analyze the unmetabolized [18F]FTHA (parent fraction). Here we present a new radiometabolite analysis (RMA) method, with comparison to a previous method for parent fraction analysis, and its use in a test-retest clinical study under fasting and postprandial conditions. We developed a new thin-layer chromatography (TLC) RMA method for analysis of [18F]FTHA parent fraction and its radiometabolites from plasma, by testing stationary phases and eluent combinations. Next, we analyzed [18F]FTHA, its radiometabolites, and plasma radioactivity from subjects participating in a clinical study. A total of 17 obese or overweight participants were dosed with [18F]FTHA twice under fasting, and twice under postprandial conditions and plasma samples were obtained between 14 min (mean of first sample) and 72 min (mean of last sample) post-injection. Aliquots of 70 plasma samples were analyzed using both methods, enabling head-to-head comparisons. We performed test-retest and group comparisons of the parent fraction and plasma radioactivity. RESULTS The new TLC method separated seven [18F]FTHA radiometabolite peaks, while the previous method separated three. The new method revealed at least one radiometabolite that was not previously separable from [18F]FTHA. From the plasma samples, the mean parent fraction value was on average 7.2 percentage points lower with the new method, compared to the previous method. Repeated [18F]FTHA investigations on the same subject revealed reproducible plasma SUV and parent fractions, with different kinetics between the fasted and postprandial conditions. CONCLUSIONS The newly developed improved radio-TLC method for [18F]FTHA RMA enables accurate parent fraction correction, which is required to obtain quantitative data for modelling [18F]FTHA PET data. Our test-retest study of fasted and postprandial conditions showed robust reproducibility, and revealed clear differences in the [18F]FTHA metabolic rate under different study settings. TRIAL REGISTRATION EudraCT No: 2020-005211-48, 04Feb2021; and Clinical Trials registry NCT05132335, 29Oct2021, URL: https://classic. CLINICALTRIALS gov/ct2/show/NCT05132335 .
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Affiliation(s)
- Richard Aarnio
- MediCity Research Laboratory, University of Turku, Turku, Finland.
- Drug Research Doctoral Programme, University of Turku, Turku, Finland.
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland.
| | - Anna Kirjavainen
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland
| | - Johan Rajander
- Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Sarita Forsback
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland
| | - Kari Kalliokoski
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland
- Department of Endocrinology, Turku University Hospital, Turku, Finland
| | | | | | - Axel Haupt
- Eli Lilly and Company, Indianapolis, IN, USA
| | | | - Merja Haaparanta-Solin
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, Turku, FI-20520, Finland
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2
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Ustsinau U, Ehret V, Fürnsinn C, Scherer T, Helbich TH, Hacker M, Krššák M, Philippe C. Novel approach using [ 18F]FTHA-PET and de novo synthesized VLDL for assessment of FFA metabolism in a rat model of diet induced NAFLD. Clin Nutr 2023; 42:1839-1848. [PMID: 37625314 DOI: 10.1016/j.clnu.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023]
Abstract
BACKGROUND AND AIMS The worldwide prevalence of Non-alcoholic Fatty Liver Disease (NAFLD) raises concerns about associated risk factors, such as obesity and type 2 Diabetes Mellitus, for leading causes of disability and death. Besides Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS), functional imaging with Positron Emission Tomography (PET) could contribute to a deeper understanding of the pathophysiology of NAFLD. Here we describe a novel approach using the PET tracer [18F]FTHA, which is an analog of long-chain free fatty acids (FFA) and is taken up by tissues to enter mitochondria or to be incorporated into complex lipids for further export as very-low-density lipoprotein (VLDL). METHODS Male Sprague Dawley rats, after 6 weeks on a high-fat diet (HFD), were used as a model of diet induced NAFLD, while a standard diet (SD) served as a control group. Liver fat was estimated by MR spectroscopy at a 9.4 T system for phenotyping. To measure hepatic FFA uptake, rats underwent 60 min dynamic [18F]FTHA-PET scans after unrestricted access to food (HFD: n = 6; SD: n = 6) or overnight (≤16h) fasting (HFD: n = 6; SD: n = 5). FFA removal was assessed from incorporated 18F-residual in de novo synthesized VLDL out of plasma. RESULTS MRS of the liver confirmed the presence of NAFLD (>5.6% fat). Under non-fasting conditions, hepatic [18F]FTHA uptake was significantly increased in NAFLD: SUVmean (p = 0.03) within [0; 60] min interval, SUVmean (p = 0.01) and SUVmax (p = 0.03) within [30; 60] min interval. SUVs for hepatic uptake under fasting conditions were not significantly different between the groups. Analysis of FFA removal demonstrated elevated values of 18F-residue in the VLDL plasma fraction of the healthy group compared to the NAFLD (p = 0.0569). CONCLUSION Our novel approach for assessing FFA metabolism using [18F]FTHA demonstrated differences in the hepatic FFA uptake and FFA incorporation into VLDL between healthy and NAFLD rats. [18F]FTHA-PET could be used to study metabolic disturbances involved in the progression of NAFLD.
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Affiliation(s)
- Usevalad Ustsinau
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Viktoria Ehret
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Clemens Fürnsinn
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Thomas Scherer
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Thomas H Helbich
- Division of Molecular and Structural Preclinical Imaging, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Martin Krššák
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Cecile Philippe
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
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3
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Bratteby K, Shalgunov V, Battisti UM, Petersen IN, van den Broek SL, Ohlsson T, Gillings N, Erlandsson M, Herth MM. Insights into Elution of Anion Exchange Cartridges: Opening the Path toward Aliphatic 18F-Radiolabeling of Base-Sensitive Tracers. ACS Pharmacol Transl Sci 2021; 4:1556-1566. [PMID: 34661074 PMCID: PMC8506604 DOI: 10.1021/acsptsci.1c00133] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 01/16/2023]
Abstract
![]()
Aliphatic nucleophilic
substitution (SN2) with [18F]fluoride is the
most widely applied method to prepare 18F-labeled positron
emission tomography (PET) tracers. Strong
basic conditions commonly used during 18F-labeling procedures
inherently limit or prohibit labeling of base-sensitive scaffolds.
The high basicity stems from the tradition to trap [18F]fluoride
on anion exchange cartridges and elute it afterward with basic anions.
This sequence is used to facilitate the transfer of [18F]fluoride from an aqueous to an aprotic organic, polar reaction
medium, which is beneficial for SN2 reactions. Furthermore,
this sequence also removes cationic radioactive contaminations from
cyclotron-irradiated [18O]water from which [18F]fluoride is produced. In this study, we developed an efficient
elution procedure resulting in low basicity that permits SN2 18F-labeling of base-sensitive scaffolds. Extensive
screening of trapping and elution conditions (>1000 experiments)
and
studying their influence on the radiochemical yield (RCY) allowed
us to identify a suitable procedure for this. Using this procedure,
four PET tracers and three synthons could be radiolabeled in substantially
higher RCYs (up to 2.5-fold) compared to those of previously published
procedures, even from lower precursor amounts. Encouraged by these
results, we applied our low-basicity method to the radiolabeling of
highly base-sensitive tetrazines, which cannot be labeled using state-of-art
direct aliphatic 18F-labeling procedures. Labeling succeeded
in RCYs of up to 20%. We believe that our findings facilitate PET
tracer development by opening the path toward simple and direct SN2 18F fluorination of base-sensitive substrates.
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Affiliation(s)
- Klas Bratteby
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark.,Department of Radiation Physics, Skåne University Hospital, Barngatan 3, 22242 Lund, Sweden.,Department of Clinical Physiology Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark.,Department of Clinical Physiology Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Umberto Maria Battisti
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark
| | - Ida Nyman Petersen
- Department of Clinical Physiology Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Sara Lopes van den Broek
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark
| | - Tomas Ohlsson
- Department of Radiation Physics, Skåne University Hospital, Barngatan 3, 22242 Lund, Sweden
| | - Nic Gillings
- Department of Clinical Physiology Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Maria Erlandsson
- Department of Radiation Physics, Skåne University Hospital, Barngatan 3, 22242 Lund, Sweden
| | - Matthias M Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark.,Department of Clinical Physiology Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
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4
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Larkina MS, Ozerskaya AV, Podrezova EV, Belousov MV, Tolmachev V, Zhdankin VV, Yusubov MS. Efficient Synthesis of ω‐[
18
F]Fluoroaliphatic Carboxylic Esters and Acids for Positron Emission Tomography. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mariia S. Larkina
- Tomsk Polytechnic University 634050 Tomsk Russia
- Siberian State Medical University 634050 Tomsk Russia
| | - Anastasia V. Ozerskaya
- Tomsk Polytechnic University 634050 Tomsk Russia
- Federal Siberian Research Clinical Centre 660037 Krasnoyarsk Russia
| | | | - Mikhail V. Belousov
- Tomsk Polytechnic University 634050 Tomsk Russia
- Siberian State Medical University 634050 Tomsk Russia
| | - Vladimir Tolmachev
- Tomsk Polytechnic University 634050 Tomsk Russia
- Department of Immunology Genetics and Pathology Uppsala University 75185 Uppsala Sweden
| | - Viktor V. Zhdankin
- Tomsk Polytechnic University 634050 Tomsk Russia
- Department of Chemistry and Biochemistry University of Minnesota Duluth Duluth Mineesota USA
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5
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Dubash SR, Keat N, Kozlowski K, Barnes C, Allott L, Brickute D, Hill S, Huiban M, Barwick TD, Kenny L, Aboagye EO. Clinical translation of 18F-fluoropivalate - a PET tracer for imaging short-chain fatty acid metabolism: safety, biodistribution, and dosimetry in fed and fasted healthy volunteers. Eur J Nucl Med Mol Imaging 2020; 47:2549-2561. [PMID: 32123971 PMCID: PMC7515955 DOI: 10.1007/s00259-020-04724-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/14/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Fatty acids derived de novo or taken up from the extracellular space are an essential source of nutrient for cell growth and proliferation. Radiopharmaceuticals including 11C-acetate, and 18F-FAC (2-18F-fluoroacetate), have previously been used to study short-chain fatty acid (SCFA) metabolism. We developed 18F-fluoropivalate (18F-FPIA; 3-18F-fluoro-2,2-dimethylpropionic acid) bearing a gem-dimethyl substituent to assert metabolic stability for studying SCFA metabolism. We report the safety, biodistribution, and internal radiation dosimetry profile of 18F-FPIA in 24 healthy volunteers and the effect of dietary conditions. MATERIALS AND METHODS Healthy volunteer male and female subjects were enrolled (n = 24), and grouped into 12 fed and 12 fasted. Non-esterified fatty acids (NEFA) and carnitine blood measurements were assessed. Subjects received 159.48 MBq (range, 47.31-164.66 MBq) of 18F-FPIA. Radiochemical purity was > 99%. Safety data were obtained during and 24 h after radiotracer administration. Subjects underwent detailed multiple whole-body PET/CT scanning with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose was calculated using OLINDA 1.1. RESULTS All subjects tolerated 18F-FPIA with no adverse events. Over 90% of radiotracer was present in plasma at 60 min post-injection. The organs receiving highest absorbed dose (in mGy/MBq) were the liver (0.070 ± 0.023), kidneys (0.043 ± 0.013), gallbladder wall (0.026 ± 0.003), and urinary bladder (0.021 ± 0.004); otherwise there was low tissue uptake. The calculated effective dose using mean organ residence times over all 24 subjects was 0.0154 mSv/MBq (SD ± 0.0010). No differences in biodistribution or dosimetry were seen in fed and fasted subjects, though systemic NEFA and carnitine levels reflected fasted and fed states. CONCLUSION The favourable safety, imaging, and dosimetric profile makes 18F-FPIA a promising candidate radiotracer for tracing SCFA metabolism.
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Affiliation(s)
- Suraiya R Dubash
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
- Department of Oncology, Imperial College Healthcare NHS Trust, London, UK
| | | | - Kasia Kozlowski
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
| | - Chris Barnes
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
| | - Louis Allott
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
| | - Diana Brickute
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
| | | | | | - Tara D Barwick
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, UK
| | - Laura Kenny
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK
- Department of Oncology, Imperial College Healthcare NHS Trust, London, UK
| | - Eric O Aboagye
- Department of Surgery and Cancer, Imperial College London, GN1 Commonwealth Building, Hammersmith Hospital, DuCane Rd, London, W12 0NN, UK.
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6
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Saari TJ, Raiko J, U-Din M, Niemi T, Taittonen M, Laine J, Savisto N, Haaparanta-Solin M, Nuutila P, Virtanen KA. Basal and cold-induced fatty acid uptake of human brown adipose tissue is impaired in obesity. Sci Rep 2020; 10:14373. [PMID: 32873825 PMCID: PMC7463032 DOI: 10.1038/s41598-020-71197-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/20/2020] [Indexed: 11/17/2022] Open
Abstract
Fatty acids (FA) are important substrates for brown adipose tissue (BAT) metabolism, however, it remains unclear whether there exists a difference in FA metabolism of BAT between lean and obese healthy humans. In this study we evaluated supraclavicular BAT fatty acid uptake (FAU) along with blood perfusion in lean and obese subjects during cold exposure and at room temperature using positron emission tomography (PET)/computed tomography (CT). Additionally, tissue samples were taken from supraclavicular region (typical BAT region) from a subset of subjects to evaluate histological presence of BAT. Non-shivering cold stress elevated FAU and perfusion of BAT in lean, but not in obese subjects. Lean subjects had greater FAU in BAT compared to obese subjects during cold exposure and interestingly also at room temperature. The higher BAT FAU was related to younger age and several indicators of superior systemic metabolic health. The subjects who manifested BAT histologically had several folds higher BAT FAU compared to subjects with no such histological manifestation. Together, obese subjects have less active tissue in supraclavicular region both in basal and cold-activated state and the FA metabolism of BAT is blunted in obesity.
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Affiliation(s)
- T J Saari
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - J Raiko
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M U-Din
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - T Niemi
- Department of Surgery, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M Taittonen
- Department of Anesthesiology, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - J Laine
- Department of Pathology, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - N Savisto
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - M Haaparanta-Solin
- Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,MediCity Research Laboratories, University of Turku, Tykistökatu 6A, 20520, Turku, Finland
| | - P Nuutila
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland.,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland
| | - K A Virtanen
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland. .,Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520, Turku, Finland. .,Institute of Public Health and Clinical Nutrition, University of Eastern Finland, PL 1627, 70211, Kuopio, Finland.
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7
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Lahdenpohja S, Keller T, Forsback S, Viljanen T, Kokkomäki E, Kivelä RV, Bergman J, Solin O, Kirjavainen AK. Automated GMP production and long-term experience in radiosynthesis of CB 1 tracer [ 18 F]FMPEP-d 2. J Labelled Comp Radiopharm 2020; 63:408-418. [PMID: 32374481 DOI: 10.1002/jlcr.3845] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/31/2020] [Accepted: 04/28/2020] [Indexed: 11/11/2022]
Abstract
Here, we describe the development of an in-house-built device for the fully automated multistep synthesis of the cannabinoid CB1 receptor imaging tracer (3R,5R)-5-(3-([18 F]fluoromethoxy-d2 )phenyl)-3-(((R)-1-phenylethyl)amino)-1-(4-(trifluoromethyl)phenyl)pyrrolidin-2-one ([18 F]FMPEP-d2 ), following good manufacturing practices. The device is interfaced to a HPLC and a sterile filtration unit in a clean room hot cell. The synthesis involves the nucleophilic 18 F-fluorination of an alkylating agent and its GC purification, the subsequent 18 F-fluoroalkylation of a precursor molecule, the semipreparative HPLC purification of the 18 F-fluoroalkylated product, and its formulation for injection. We have optimized the duration and temperature of the 18 F-fluoroalkylation reaction and addressed the radiochemical stability of the formulated product. During the past 5 years (2013-2018), we have performed a total of 149 syntheses for clinical use with a 90% success rate. The activity yield of the formulated product has been 1.0 ± 0.4 GBq starting from 11 ± 2 GBq and the molar activity 600 ± 300 GBq/μmol at the end of synthesis.
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Affiliation(s)
- Salla Lahdenpohja
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Thomas Keller
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Sarita Forsback
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
- Department of Chemistry, University of Turku, Turku, Finland
| | - Tapio Viljanen
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Esa Kokkomäki
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Riikka V Kivelä
- Hospital Pharmacy, Turku University Hospital, Turku, Finland
| | - Jörgen Bergman
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Olof Solin
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
- Department of Chemistry, University of Turku, Turku, Finland
- Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Anna K Kirjavainen
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
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8
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Pandey MK, Jacobson MS, Groth EK, Tran NG, Lowe VJ, DeGrado TR. Radiation induced oxidation of [ 18F]fluorothia fatty acids under cGMP manufacturing conditions. Nucl Med Biol 2019; 80-81:13-23. [PMID: 31759313 DOI: 10.1016/j.nucmedbio.2019.11.004] [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: 08/21/2019] [Revised: 11/02/2019] [Accepted: 11/07/2019] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The objectives of the present work were to optimize and validate the synthesis and stability of 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid ([18F]FTHA) and 16-[18F]fluoro-4-thia-palmitic acid ([18F]FTP) under cGMP conditions for clinical applications. METHODS Benzyl-14-(R,S)-tosyloxy-6-thiaheptadecanoate and methyl 16-bromo-4-thia-palmitate were used as precursors for the synthesis of [18F]FTHA and [18F]FTP, respectively. For comparison, a fatty acid analog lacking a thia-substitution, 16-[18F]fluoro-palmitic acid ([18F]FP), was synthesized from the precursor methyl 16-bromo-palmitate. A standard nucleophilic reaction using cryptand (Kryptofix/K222, 8.1 mg), potassium carbonate (K2CO3, 4.0 mg) and 18F-fluoride were employed for the 18F-labeling and potassium hydroxide (0.8 M) was used for the post-labeling ester hydrolysis. The final products were purified via reverse phase semi-preparative HPLC and concentrated via trap and release on a C-18 plus solid phase extraction cartridge. The radiochemical purities of the [18F]fluorothia fatty acids and [18F]FP were examined over a period of 4 h post-synthesis using an analytical HPLC. All the syntheses were optimized in an automated TRACERlab FX-N Pro synthesizer. Liquid chromatography mass spectrometry (LCMS) and high resolution mass spectrometry (HRMS) was employed to study the identity and nature of side products formed during radiosynthesis and as a consequence of post-synthesis radiation induced oxidation. RESULTS Radiosyntheses of [18F]FTHA, [18F]FTP and [18F]FP were achieved in moderate (8-20% uncorrected) yields. However, it was observed that the HPLC-purified [18F]fluorothia fatty acids, [18F]FTHA and [18F]FTP at higher radioactivity concentrations (>1.11 GBq/mL, 30 mCi/mL) underwent formation of 18F-labeled side products over time but [18F]FP (lacking a sulfur heteroatom) remained stable up to 4 h post-synthesis. Various radiation protectors like ethanol and ascorbic acid were examined to minimize the formation of side products formed during [18F]FTHA and [18F]FTP synthesis but showed only limited to no effect. Analysis of the side products by LCMS showed formation of sulfoxides of both [18F]FTHA and [18F]FTP. The identity of the sulfoxide side product was further confirmed by synthesizing a non-radioactive reference standard of the sulfoxide analog of FTP and matching retention times on HPLC and molecular ion peaks on LC/HRMS. Radiation-induced oxidation of the sulfur heteroatom was mitigated by dilution of product with isotonic saline to reduce the radioactivity concentration to <0.518 GBq/mL (14 mCi/mL). CONCLUSIONS Successful automated synthesis of [18F]fluorothia fatty acids were carried out in cGMP facility for their routine production and clinical applications. Instability of [18F]fluorothia fatty acids were observed at radioactivity concentrations exceeding 1.11 GBq/mL (30 mCi/mL) but mitigated through dilution of the product to <0.518 GBq/mL (14 mCi/mL). The identities of the side products formed were established as the sulfoxides of the respective thia fatty acids caused by radiation-induced oxidation of the sulfur heteroatom.
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Affiliation(s)
- Mukesh K Pandey
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America.
| | - Mark S Jacobson
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America
| | - Emily K Groth
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America
| | - Natalie G Tran
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America
| | - Val J Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America
| | - Timothy R DeGrado
- Department of Radiology, Mayo Clinic, Rochester, MN 55906, United States of America.
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Lahdenpohja S, Keller T, Rajander J, Kirjavainen AK. Radiosynthesis of the norepinephrine transporter tracer [ 18 F]NS12137 via copper-mediated 18 F-labelling. J Labelled Comp Radiopharm 2019; 62:259-264. [PMID: 30843249 PMCID: PMC6619244 DOI: 10.1002/jlcr.3717] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/18/2019] [Accepted: 02/25/2019] [Indexed: 12/12/2022]
Abstract
[18F]NS12137 (exo‐3‐[(6‐[18F]fluoro‐2‐pyridyl)oxy]8‐azabicyclo[3.2.1]octane) is a highly selective norepinephrine transporter (NET) tracer. NETs are responsible for the reuptake of norepinephrine and dopamine and are linked to several neurodegenerative and neuropsychiatric disorders. The aim of this study was to develop a copper‐mediated 18F‐fluorination method for the production of [18F]NS12137 with straightforward synthesis conditions and high radiochemical yield and molar activity. [18F]NS12137 was produced in two steps. Radiofluorination of [18F]NS12137 was performed via a copper‐mediated pathway starting with a stannane precursor and using [18F]F− as the source of the fluorine‐18 isotope. Deprotection was performed via acid hydrolysis. The radiofluorination reaction was nearly quantitative as was the deprotection based on HPLC analysis. The radiochemical yield of the synthesis was 15.1 ± 0.5%. Molar activity of [18F]NS12137 was up to 300 GBq/μmol. The synthesis procedure is straightforward and can easily be automated and adapted for clinical production.
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Affiliation(s)
- Salla Lahdenpohja
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Thomas Keller
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Johan Rajander
- Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Anna K Kirjavainen
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
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10
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Motiani KK, Savolainen AM, Toivanen J, Eskelinen JJ, Yli-Karjanmaa M, Virtanen KA, Saunavaara V, Heiskanen MA, Parkkola R, Haaparanta-Solin M, Solin O, Savisto N, Löyttyniemi E, Knuuti J, Nuutila P, Kalliokoski KK, Hannukainen JC. Effects of short-term sprint interval and moderate-intensity continuous training on liver fat content, lipoprotein profile, and substrate uptake: a randomized trial. J Appl Physiol (1985) 2019; 126:1756-1768. [PMID: 30998125 DOI: 10.1152/japplphysiol.00900.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Type 2 diabetes (T2D) and increased liver fat content (LFC) alter lipoprotein profile and composition and impair liver substrate uptake. Exercise training mitigates T2D and reduces LFC, but the benefits of different training intensities in terms of lipoprotein classes and liver substrate uptake are unclear. The aim of this study was to evaluate the effects of moderate-intensity continuous training (MICT) or sprint interval training (SIT) on LFC, liver substrate uptake, and lipoprotein profile in subjects with normoglycemia or prediabetes/T2D. We randomized 54 subjects (normoglycemic group, n = 28; group with prediabetes/T2D, n = 26; age = 40-55 yr) to perform either MICT or SIT for 2 wk and measured LFC with magnetic resonance spectroscopy, lipoprotein composition with NMR, and liver glucose uptake (GU) and fatty acid uptake (FAU) using PET. At baseline, the group with prediabetes/T2D had higher LFC, impaired lipoprotein profile, and lower whole body insulin sensitivity and aerobic capacity compared with the normoglycemic group. Both training modes improved aerobic capacity (P < 0.001) and lipoprotein profile (reduced LDL and increased large HDL subclasses; all P < 0.05) with no training regimen (SIT vs. MICT) or group effect (normoglycemia vs. prediabetes/T2D). LFC tended to be reduced in the group with prediabetes/T2D compared with the normoglycemic group posttraining (P = 0.051). When subjects were divided according to LFC (high LFC, >5.6%; low LFC, <5.6%), training reduced LFC in subjects with high LFC (P = 0.009), and only MICT increased insulin-stimulated liver GU (P = 0.03). Short-term SIT and MICT are effective in reducing LFC in subjects with fatty liver and in improving lipoprotein profile regardless of baseline glucose tolerance. Short-term MICT is more efficient in improving liver insulin sensitivity compared with SIT. NEW & NOTEWORTHY In the short term, both sprint interval training and moderate-intensity continuous training (MICT) reduce liver fat content and improve lipoprotein profile; however, MICT seems to be preferable in improving liver insulin sensitivity.
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Affiliation(s)
| | | | | | | | | | | | - Virva Saunavaara
- Turku PET Centre, University of Turku , Turku , Finland.,Department of Medical Physics, Turku University Hospital , Turku , Finland
| | | | - Riitta Parkkola
- Department of Radiology, Turku University Hospital , Turku , Finland
| | - Merja Haaparanta-Solin
- Turku PET Centre, University of Turku , Turku , Finland.,MediCity Research Laboratory Turku, University of Turku , Turku , Finland
| | - Olof Solin
- Turku PET Centre, University of Turku , Turku , Finland.,Department of Chemistry, University of Turku , Turku , Finland.,Turku PET Centre, Åbo Akademi University , Turku , Finland
| | - Nina Savisto
- Turku PET Centre, University of Turku , Turku , Finland
| | | | - Juhani Knuuti
- Turku PET Centre, University of Turku , Turku , Finland
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku , Turku , Finland.,Department of Endocrinology, Turku University Hospital , Turku , Finland
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11
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U Din M, Saari T, Raiko J, Kudomi N, Maurer SF, Lahesmaa M, Fromme T, Amri EZ, Klingenspor M, Solin O, Nuutila P, Virtanen KA. Postprandial Oxidative Metabolism of Human Brown Fat Indicates Thermogenesis. Cell Metab 2018; 28:207-216.e3. [PMID: 29909972 DOI: 10.1016/j.cmet.2018.05.020] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 10/31/2017] [Accepted: 05/22/2018] [Indexed: 12/26/2022]
Abstract
Human studies suggest that a meal elevates glucose uptake in brown adipose tissue (BAT). However, in postprandial state the thermogenic activity and the metabolism of non-esterified fatty acids (NEFAs) in BAT remain unclear. Using indirect calorimetry combined with positron emission tomography and computed tomography (PET/CT), we showed that whole-body and BAT thermogenesis (oxygen consumption) increases after the ingestion of a mixed carbohydrate-rich meal, to the same extent as in cold stress. Postprandial NEFA uptake into BAT is minimal, possibly due to elevated plasma insulin inhibiting lipolysis. However, the variation in postprandial NEFA uptake is linked to BAT thermogenesis. We identified several genes participating in lipid metabolism to be expressed at higher levels in BAT compared with white fat in postprandial state, and to be positively correlated with BAT UCP1 expression. These findings suggest that substrates preferred by BAT in postprandial state are glucose or LPL-released NEFAs due to insulin stimulation.
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Affiliation(s)
- Mueez U Din
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland
| | - Teemu Saari
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland
| | - Juho Raiko
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland
| | - Nobu Kudomi
- Department of Medical Physics, Faculty of Medicine, Kagawa University, Takamatsu, Kagawa, Japan
| | - Stefanie F Maurer
- Chair of Molecular Nutritional Medicine, Else Kröner-Fresenius Center, Technical University of Munich, 85354 Freising, Germany
| | - Minna Lahesmaa
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, Else Kröner-Fresenius Center, Technical University of Munich, 85354 Freising, Germany
| | | | - Martin Klingenspor
- Chair of Molecular Nutritional Medicine, Else Kröner-Fresenius Center, Technical University of Munich, 85354 Freising, Germany; ZIEL - Institute for Food and Health, Technical University of Munich, 85354 Freising, Germany
| | - Olof Solin
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Department of Chemistry, University of Turku, Turku, Finland; Accelerator Laboratory, Åbo Akademi University, Turku, Finland
| | - Pirjo Nuutila
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Department of Endocrinology, Turku University Hospital, Turku, Finland
| | - Kirsi A Virtanen
- Turku PET Centre, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku, Finland; Institute of Public Health and Clinical Nutrition, University of Eastern Finland (UEF), Kuopio, Finland.
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