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Miranda A, Bertoglio D, Staelens S, Verhaeghe J. Accurate image derived input function in [ 18F]SynVesT-1 mouse studies using isoflurane and ketamine/xylazine anesthesia. EJNMMI Phys 2023; 10:78. [PMID: 38052966 DOI: 10.1186/s40658-023-00599-8] [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: 07/24/2023] [Accepted: 11/28/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND Kinetic modeling in positron emission tomography (PET) requires measurement of the tracer plasma activity in the absence of a suitable reference region. To avoid invasive blood sampling, the use of an image derived input function has been proposed. However, an accurate delineation of the blood pool region in the PET image is necessary to obtain unbiased blood activity. Here, to perform brain kinetic modeling in [18F]SynVesT-1 dynamic scans, we make use of non-negative matrix factorization (NMF) to unmix the activity signal from the different tissues that can contribute to the heart region activity, and extract only the left ventricle activity in an unbiased way. This method was implemented in dynamic [18F]SynVesT-1 scans of mice anesthetized with either isoflurane or ketamine-xylazine, two anesthestics that we showed to affect differently radiotracer kinetics. The left ventricle activity (NMF-IDIF) and a manually delineated cardiac activity (IDIF) were compared with arterial blood samples (ABS), and for isoflurane anesthetized mice, arteriovenous (AV) shunt blood data were compared as well. Finally, brain regional 2 tissue compartment modeling was performed using IDIF and NMF-IDIF, and the model fit accuracy (weighted symmetrical mean absolute percentage error, wsMAPE) as well as the total volume of distribution (VT) were compared. RESULTS In isoflurane anesthetized mice, the difference between ABS and NMF-IDIF activity (+ 12.8 [Formula: see text] 11%, p = 0.0023) was smaller than with IDIF (+ 16.4 [Formula: see text] 9.8%, p = 0.0008). For ketamine-xylazine anesthetized mice the reduction in difference was larger (NMF-IDIF: 16.9 [Formula: see text] 10%, p = 0.0057, IDIF: 56.3 [Formula: see text] 14%, p < 0.0001). Correlation coefficient between isoflurane AV-shunt time activity curves and NMF-IDIF (0.97 [Formula: see text] 0.01) was higher than with IDIF (0.94 [Formula: see text] 0.03). The brain regional 2TCM wsMAPE was improved using NMF-IDIF compared with IDIF, in isoflurane (NMF-IDIF: 1.24 [Formula: see text] 0.24%, IDIF: 1.56 [Formula: see text] 0.30%) and ketamine-xylazine (NMF-IDIF: 1.40 [Formula: see text] 0.24, IDIF: 2.62 [Formula: see text] 0.27) anesthetized mice. Finally, brain VT was significantly (p < 0.0001) higher using NMF-IDIF compared with IDIF, in isoflurane (3.97 [Formula: see text] 0.13% higher) and ketamine-xylazine (32.7 [Formula: see text] 2.4% higher) anesthetized mice. CONCLUSIONS Image derived left ventricle blood activity calculated with NMF improves absolute activity quantification, and reduces the error in the kinetic modeling fit. These improvements are more pronounced in ketamine-xylazine than in isoflurane anesthetized mice.
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Affiliation(s)
- Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.
| | - Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
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Miranda A, Bertoglio D, De Weerdt C, Staelens S, Verhaeghe J. Isoflurane and ketamine-xylazine modify pharmacokinetics of [ 18F]SynVesT-1 in the mouse brain. J Cereb Blood Flow Metab 2023; 43:1612-1624. [PMID: 37113068 PMCID: PMC10414002 DOI: 10.1177/0271678x231173185] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/15/2023] [Accepted: 03/26/2023] [Indexed: 04/29/2023]
Abstract
We investigated the effect of isoflurane and ketamine-xylazine anesthesia on the positron emission tomography (PET) tracer [18F]SynVesT-1 in the mouse brain. [18F]SynVesT-1 PET scans were performed in C57BL/6J mice in five conditions: isoflurane anesthesia (ANISO), ketamine-xylazine (ANKX), awake freely moving (AW), awake followed by isoflurane administration (AW/ANISO) or followed by ketamine-xylazine (AW/ANKX) 20 min post tracer injection. ANISO, ANKX and AW scans were also performed in mice administered with levetiracetam (LEV, 200 mg/kg) to assess non-displaceable binding. Metabolite analysis was performed in ANISO, ANKX and AW mice. Finally, in vivo autoradiography in ANISO, ANKX and AW mice at 30 min post-injection was performed for validation. Kinetic modeling, with a metabolite corrected image derived input function, was performed to calculate total and non-displaceable volume of distribution (VT(IDIF)). VT(IDIF) was higher in ANISO compared to AW (p < 0.0001) while VT(IDIF) in ANKX was lower compared with AW (p < 0.0001). Non-displaceable VT(IDIF) was significantly different between ANISO and AW, but not between ANKX and AW. Change in the TAC washout was observed after administration of either isoflurane or ketamine-xylazine. Observed changes in tracer kinetics and volume of distribution might be explained by physiological changes due to anesthesia, as well as by induced cellular effects.
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Affiliation(s)
- Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Daniele Bertoglio
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Caro De Weerdt
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
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Xiong M, Roshanbin S, Sehlin D, Hansen HD, Knudsen GM, Rokka J, Eriksson J, Syvänen S. Synaptic density in aging mice measured by [ 18F]SynVesT-1 PET. Neuroimage 2023:120230. [PMID: 37355199 DOI: 10.1016/j.neuroimage.2023.120230] [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: 12/03/2022] [Revised: 05/03/2023] [Accepted: 06/14/2023] [Indexed: 06/26/2023] Open
Abstract
Synaptic alterations in certain brain structures are related to cognitive decline in neurodegeneration and in aging. Synaptic loss in many neurodegenerative diseases can be visualized by positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A). However, the use of SV2A PET for studying synaptic changes during aging is not particularly explored. Thus, in the present study, PET ligand [18F]SynVesT-1, which binds to SV2A, was used to investigate synaptic density at different ages in healthy mice. Wild type C57BL/6 mice divided into three age groups (4-5 months (n = 7), 12-14 months (n = 11), 17-19 months (n = 7)) were PET scanned with [18F]SynVesT-1. Brain retention of [18F]SynVesT-1 expressed as the volume of distribution (VIDIF) was calculated using an image-derived input function. Estimates of VIDIF were derived using either a one-tissue compartment model (1TCM), a two-tissue compartment model (2TCM), or the Logan plot with blood input to find the best-fit model for [18F]SynVesT-1. After the PET scans, tissue sections were immunostained for the detection of SV2A and neuronal markers. We found that [18F]SynVesT-1 data acquired 60 min post intravenously injection and analyzed with 1TCM described the brain pharmacokinetics of the radioligand in mice well. [18F]SynVesT-1 brain retention was lower in the oldest group of mice, indicating a decrease in synaptic density in this age group. However, no gradual age-dependent decrease in synaptic density at a region-specific level was observed. Immunostaining indicated that SV2A expression and neuron numbers were similar across all three age groups. In general, these data obtained in healthy aging mice are consistent with previous findings in humans where synaptic density appeared stable during aging up to a certain age, after which a small decrease is observed.
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Affiliation(s)
- Mengfei Xiong
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Sahar Roshanbin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Dag Sehlin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Hanne D Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Johanna Rokka
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Jonas Eriksson
- PET Centre, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Medicinal Chemistry, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Stina Syvänen
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
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Bertoglio D, Zajicek F, Lombaerde SD, Miranda A, Stroobants S, Wang Y, Dominguez C, Munoz-Sanjuan I, Bard J, Liu L, Verhaeghe J, Staelens S. Validation, kinetic modeling, and test-retest reproducibility of [ 18F]SynVesT-1 for PET imaging of synaptic vesicle glycoprotein 2A in mice. J Cereb Blood Flow Metab 2022; 42:1867-1878. [PMID: 35570828 PMCID: PMC9536120 DOI: 10.1177/0271678x221101648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alterations in synaptic vesicle glycoprotein 2 A (SV2A) have been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, SV2A positron emission tomography (PET) imaging may provide a unique tool to investigate synaptic density dynamics during disease progression and after therapeutic intervention. This study aims to extensively characterize the novel radioligand [18F]SynVesT-1 for preclinical applications. In C57Bl/6J mice (n = 39), we assessed the plasma profile of [18F]SynVesT-1, validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function (AIF), performed a blocking study with levetiracetam (50 and 200 mg/kg, i.p.) to verify the specificity towards SV2A, examined kinetic models for volume of distribution (VT) quantification, and explored test-retest reproducibility of [18F]SynVesT-1 in the central nervous system (CNS). Plasma availability of [18F]SynVesT-1 decreased rapidly (13.4 ± 1.5% at 30 min post-injection). VT based on AIF and IDIF showed excellent agreement (r2 = 0.95, p < 0.0001) and could be reliably estimated with a 60-min acquisition. The blocking study resulted in a complete blockade with no suitable reference region. Test-retest analysis indicated good reproducibility (mean absolute variability <10%). In conclusion, [18F]SynVesT-1 is selective for SV2A with optimal kinetics representing a candidate tool to quantify CNS synaptic density non-invasively.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Franziska Zajicek
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Stef De Lombaerde
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Yuchuan Wang
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Celia Dominguez
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | | | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
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Mills JA, Humphries J, Simpson JD, Sonderegger SE, Thurecht KJ, Fletcher NL. Modulating Macrophage Clearance of Nanoparticles: Comparison of Small-Molecule and Biologic Drugs as Pharmacokinetic Modifiers of Soft Nanomaterials. Mol Pharm 2022; 19:4080-4097. [PMID: 36069540 DOI: 10.1021/acs.molpharmaceut.2c00528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanomedicines show benefits in overcoming the limitations of conventional drug delivery systems by reducing side effects, toxicity, and exhibiting enhanced pharmacokinetic (PK) profiles to improve the therapeutic window of small-molecule drugs. However, upon administration, many nanoparticles (NPs) prompt induction of host innate immune responses, which in combination with other clearance pathways such as renal and hepatic, eliminate up to 99% of the administered dose. Here, we explore a drug predosing strategy to transiently suppress the mononuclear phagocyte system (MPS), subsequently improving the PK profile and biological behaviors exhibited by a model NP system [hyperbranched polymers (HBPs)] in an immunocompetent mouse model. In vitro assays allowed the identification of five drug candidates that attenuated cellular association. Predosing of lead compounds chloroquine (CQ) and zoledronic acid (ZA) further showed increased HBP retention within the circulatory system of mice, as shown by both fluorescence imaging and positron emission tomography-computed tomography. Flow cytometric evaluation of spleen and liver tissue cells following intravenous administration further demonstrated that CQ and ZA significantly reduced HBP association with myeloid cells by 23 and 16%, respectively. The results of this study support the use of CQ to pharmacologically suppress the MPS to improve NP PKs.
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Affiliation(s)
- Jessica A Mills
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia.,Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technologies, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - James Humphries
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia.,Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technologies, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Joshua D Simpson
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia.,Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technologies, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Stefan E Sonderegger
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Kristofer J Thurecht
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia.,Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technologies, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Nicholas L Fletcher
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia.,Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technologies, The University of Queensland, St Lucia, Queensland 4072, Australia
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6
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Spurrier J, Nicholson L, Fang XT, Stoner AJ, Toyonaga T, Holden D, Siegert TR, Laird W, Allnutt MA, Chiasseu M, Brody AH, Takahashi H, Nies SH, Pérez-Cañamás A, Sadasivam P, Lee S, Li S, Zhang L, Huang YH, Carson RE, Cai Z, Strittmatter SM. Reversal of synapse loss in Alzheimer mouse models by targeting mGluR5 to prevent synaptic tagging by C1Q. Sci Transl Med 2022; 14:eabi8593. [PMID: 35648810 PMCID: PMC9554345 DOI: 10.1126/scitranslmed.abi8593] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Microglia-mediated synaptic loss contributes to the development of cognitive impairments in Alzheimer's disease (AD). However, the basis for this immune-mediated attack on synapses remains to be elucidated. Treatment with the metabotropic glutamate receptor 5 (mGluR5) silent allosteric modulator (SAM), BMS-984923, prevents β-amyloid oligomer-induced aberrant synaptic signaling while preserving physiological glutamate response. Here, we show that oral BMS-984923 effectively occupies brain mGluR5 sites visualized by [18F]FPEB positron emission tomography (PET) at doses shown to be safe in rodents and nonhuman primates. In aged mouse models of AD (APPswe/PS1ΔE9 overexpressing transgenic and AppNL-G-F/hMapt double knock-in), SAM treatment fully restored synaptic density as measured by [18F]SynVesT-1 PET for SV2A and by histology, and the therapeutic benefit persisted after drug washout. Phospho-TAU accumulation in double knock-in mice was also reduced by SAM treatment. Single-nuclei transcriptomics demonstrated that SAM treatment in both models normalized expression patterns to a far greater extent in neurons than glia. Last, treatment prevented synaptic localization of the complement component C1Q and synaptic engulfment in AD mice. Thus, selective modulation of mGluR5 reversed neuronal gene expression changes to protect synapses from damage by microglial mediators in rodents.
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Affiliation(s)
- Joshua Spurrier
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - LaShae Nicholson
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Xiaotian T Fang
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Austin J Stoner
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Takuya Toyonaga
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Daniel Holden
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | | | - William Laird
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Mary Alice Allnutt
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Marius Chiasseu
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - A Harrison Brody
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Hideyuki Takahashi
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Sarah Helena Nies
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA.,Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, Tübingen 72074, Germany
| | - Azucena Pérez-Cañamás
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Pragalath Sadasivam
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Supum Lee
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Songye Li
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Le Zhang
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Yiyun H Huang
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Richard E Carson
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Zhengxin Cai
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
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Glorie D, Verhaeghe J, Miranda A, De Lombaerde S, Stroobants S, Staelens S. Quantification of Metabotropic Glutamate Receptor 5 Availability With Both [ 11C]ABP688 and [ 18F]FPEB Positron Emission Tomography in the Sapap3 Knockout Mouse Model for Obsessive-Compulsive-like Behavior. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2022; 7:607-615. [PMID: 34856382 DOI: 10.1016/j.bpsc.2021.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/17/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND This study provides a first direct comparison between positron emission tomography radioligands targeting the allosteric site of the metabotropic glutamate receptor 5 (mGluR5): [11C]ABP688 and [18F]FPEB. A blocking paradigm was set up to substantiate the common binding site of both radioligands. Second, both radioligands were applied in Sapap3 knockout (KO) mice showing compulsive-like behavior characterized by a lower in vivo mGluR5 availability. METHODS First, wild-type mice (n = 7) received four position emission tomography/computed tomography scans: a [11C]ABP688 scan, a [18F]FPEB scan, and two blocking scans using cold FPEB and cold ABP688, respectively. A second experiment compared both radioligands in wild-type (n = 7) and KO (n = 10) mice. The simplified reference tissue model was used to calculate the nondisplaceable binding potential representing the in vivo availability of mGluR5 in the brain. RESULTS Using cold FPEB as a blocking compound for [11C]ABP688 micro-positron emission tomography and vice versa, we observed averaged global reductions in mGluR5 availability of circa 98% for [11C]ABP688 and 82%-96% for [18F]FPEB. For KOs, the [11C]ABP688 nondisplaceable binding potential was on average 25% lower compared with wild-type control mice (p < .0001-.001), while this was about 17% for [18F]FPEB (p < .05). CONCLUSIONS The current findings substantiate a common binding site and suggest a strong relationship between mGluR5 availability levels measured with both radioligands. In Sapap3 KO mice, a reduced mGluR5 availability could therefore be demonstrated with both radioligands. With [11C]ABP688, higher significance levels were achieved in more brain regions. These findings suggest [11C]ABP688 as a preferable radiotracer to quantify mGluR5 availability, as exemplified here in a model for compulsive-like behavior.
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Affiliation(s)
- Dorien Glorie
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium
| | - Stef De Lombaerde
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium; Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium; Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Wilrijk, Belgium.
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8
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Syvänen S, Meier SR, Roshanbin S, Xiong M, Faresjö R, Gustavsson T, Bonvicini G, Schlein E, Aguilar X, Julku U, Eriksson J, Sehlin D. PET Imaging in Preclinical Anti-Aβ Drug Development. Pharm Res 2022; 39:1481-1496. [PMID: 35501533 PMCID: PMC9246809 DOI: 10.1007/s11095-022-03277-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/25/2022] [Indexed: 11/21/2022]
Abstract
Positron emission tomography (PET), a medical imaging technique allowing for studies of the living human brain, has gained an important role in clinical trials of novel drugs against Alzheimer’s disease (AD). For example, PET data contributed to the conditional approval in 2021 of aducanumab, an antibody directed towards amyloid-beta (Aβ) aggregates, by showing a dose-dependent reduction in brain amyloid after treatment. In parallel to clinical studies, preclinical studies in animal models of Aβ pathology may also benefit from PET as a tool to detect target engagement and treatment effects of anti-Aβ drug candidates. PET is associated with a high level of translatability between species as similar, non-invasive protocols allow for longitudinal rather than cross-sectional studies and can be used both in a preclinical and clinical setting. This review focuses on the use of preclinical PET imaging in genetically modified animals that express human Aβ, and its present and potential future role in the development of drugs aimed at reducing brain Aβ levels as a therapeutic strategy to halt disease progression in AD.
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Affiliation(s)
- Stina Syvänen
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden.
| | - Silvio R Meier
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Sahar Roshanbin
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Mengfei Xiong
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Rebecca Faresjö
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Tobias Gustavsson
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Gillian Bonvicini
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden.,BioArctic AB, Stockholm, Sweden
| | - Eva Schlein
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Ximena Aguilar
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Ulrika Julku
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
| | - Jonas Eriksson
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden.,PET Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Dag Sehlin
- Department of Public Health and Caring Sciences, Uppsala University, Dag Hammarskjöldsväg 20, 75185, Uppsala, Sweden
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9
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Bertoglio D, Bard J, Hessmann M, Liu L, Gärtner A, De Lombaerde S, Huscher B, Zajicek F, Miranda A, Peters F, Herrmann F, Schaertl S, Vasilkovska T, Brown CJ, Johnson PD, Prime ME, Mills MR, Van der Linden A, Mrzljak L, Khetarpal V, Wang Y, Marchionini DM, Skinbjerg M, Verhaeghe J, Dominguez C, Staelens S, Munoz-Sanjuan I. Development of a ligand for in vivo imaging of mutant huntingtin in Huntington's disease. Sci Transl Med 2022; 14:eabm3682. [PMID: 35108063 DOI: 10.1126/scitranslmed.abm3682] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion in the huntingtin (HTT) gene that encodes the pathologic mutant HTT (mHTT) protein with an expanded polyglutamine (polyQ) tract. Whereas several therapeutic programs targeting mHTT expression have advanced to clinical evaluation, methods to visualize mHTT protein species in the living brain are lacking. Here, we demonstrate the development and characterization of a positron emission tomography (PET) imaging radioligand with high affinity and selectivity for mHTT aggregates. This small molecule radiolabeled with 11C ([11C]CHDI-180R) allowed noninvasive monitoring of mHTT pathology in the brain and could track region- and time-dependent suppression of mHTT in response to therapeutic interventions targeting mHTT expression in a rodent model. We further showed that in these animals, therapeutic agents that lowered mHTT in the striatum had a functional restorative effect that could be measured by preservation of striatal imaging markers, enabling a translational path to assess the functional effect of mHTT lowering.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium
| | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, CA 90045, USA
| | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA 90045, USA
| | | | - Stef De Lombaerde
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem 2650, Belgium
| | | | - Franziska Zajicek
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | - Yuchuan Wang
- CHDI Management/CHDI Foundation, Los Angeles, CA 90045, USA
| | | | | | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium
| | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk 2610, Belgium
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10
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NRM 2021 Abstract Booklet. J Cereb Blood Flow Metab 2021; 41:11-309. [PMID: 34905986 PMCID: PMC8851538 DOI: 10.1177/0271678x211061050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Longitudinal preclinical evaluation of the novel radioligand [11C]CHDI-626 for PET imaging of mutant huntingtin aggregates in Huntington's disease. Eur J Nucl Med Mol Imaging 2021; 49:1166-1175. [PMID: 34651228 PMCID: PMC8921134 DOI: 10.1007/s00259-021-05578-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 09/28/2021] [Indexed: 12/25/2022]
Abstract
Purpose
As several therapies aimed at lowering mutant huntingtin (mHTT) brain levels in Huntington’s disease (HD) are currently being investigated, noninvasive positron emission tomography (PET) imaging of mHTT could be utilized to directly evaluate therapeutic efficacy and monitor disease progression. Here we characterized and longitudinally assessed the novel radioligand [11C]CHDI-626 for mHTT PET imaging in the zQ175DN mouse model of HD. Methods After evaluating radiometabolites and radioligand kinetics, we conducted longitudinal dynamic PET imaging at 3, 6, 9, and 13 months of age (M) in wild-type (WT, n = 17) and heterozygous (HET, n = 23) zQ175DN mice. Statistical analysis was performed to evaluate temporal and genotypic differences. Cross-sectional cohorts at each longitudinal time point were included for post-mortem [3H]CHDI-626 autoradiography. Results Despite fast metabolism and kinetics, the radioligand was suitable for PET imaging of mHTT. Longitudinal quantification could discriminate between genotypes already at premanifest stage (3 M), showing an age-associated increase in signal in HET mice in parallel with mHTT aggregate load progression, as supported by the post-mortem [3H]CHDI-626 autoradiography. Conclusion With clinical evaluation underway, [11C]CHDI-626 PET imaging appears to be a suitable preclinical candidate marker to monitor natural HD progression and for the evaluation of mHTT-lowering therapies. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05578-8.
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12
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Mertens N, Schmidt ME, Hijzen A, Van Weehaeghe D, Ravenstijn P, Depre M, de Hoon J, Van Laere K, Koole M. Minimally invasive quantification of cerebral P2X7R occupancy using dynamic [ 18F]JNJ-64413739 PET and MRA-driven image derived input function. Sci Rep 2021; 11:16172. [PMID: 34373571 PMCID: PMC8352986 DOI: 10.1038/s41598-021-95715-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 07/29/2021] [Indexed: 01/21/2023] Open
Abstract
[18F]JNJ-64413739 has been evaluated as PET-ligand for in vivo quantification of purinergic receptor subtype 7 receptor (P2X7R) using Logan graphical analysis with a metabolite-corrected arterial plasma input function. In the context of a P2X7R PET dose occupancy study, we evaluated a minimally invasive approach by limiting arterial sampling to baseline conditions. Meanwhile, post dose distribution volumes (VT) under blocking conditions were estimated by combining baseline blood to plasma ratios and metabolite fractions with an MR angiography driven image derived input function (IDIF). Regional postdose VT,IDIF values were compared with corresponding VT,AIF estimates using a arterial input function (AIF), in terms of absolute values, test–retest reliability and receptor occupancy. Compared to an invasive AIF approach, postdose VT,IDIF values and corresponding receptor occupancies showed only limited bias (Bland–Altman analysis: 0.06 ± 0.27 and 3.1% ± 6.4%) while demonstrating a high correlation (Spearman ρ = 0.78 and ρ = 0.98 respectively). In terms of test–retest reliability, regional intraclass correlation coefficients were 0.98 ± 0.02 for VT,IDIF compared to 0.97 ± 0.01 for VT,AIF. These results confirmed that a postdose IDIF, guided by MR angiography and using baseline blood and metabolite data, can be considered for accurate [18F]JNJ-64413739 PET quantification in a repeated PET study design, thus avoiding multiple invasive arterial sampling and increasing dosing flexibility.
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Affiliation(s)
- Nathalie Mertens
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium.
| | | | - Anja Hijzen
- Janssen Research and Development, Beerse, Belgium
| | - Donatienne Van Weehaeghe
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | | | - Marleen Depre
- Center for Clinical Pharmacology, University Hospital and KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospital and KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University Hospital and KU Leuven, Herestraat 49, 3000, Leuven, Belgium
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13
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Bertoglio D, Verhaeghe J, Korat Š, Miranda A, Wyffels L, Stroobants S, Mrzljak L, Dominguez C, Liu L, Skinbjerg M, Munoz-Sanjuan I, Staelens S. In vitro and In vivo Assessment of Suitable Reference Region and Kinetic Modelling for the mGluR1 Radioligand [ 11C]ITDM in Mice. Mol Imaging Biol 2021; 22:854-863. [PMID: 31792838 PMCID: PMC7343737 DOI: 10.1007/s11307-019-01435-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE This study aimed at investigating binding specificity, suitability of reference region-based kinetic modelling, and pharmacokinetics of the metabotropic glutamate receptor 1 (mGluR1) radioligand [11C]ITDM in mice. PROCEDURES We performed in vivo blocking as well as displacement of [11C]ITDM during positron emission tomography (PET) imaging using the specific mGluR1 antagonist YM-202074. Additionally, we assessed in vitro blocking of [3H]ITDM at two different doses of YM-202074. As an alternative to reference region models, we validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function measured with an invasive arteriovenous (AV) shunt using a population-based curve for radiometabolite correction and characterized the pharmacokinetic modelling of [11C]ITDM in the mouse brain. Finally, we also assessed semi-quantitative approaches. RESULTS In vivo blocking with YM-202074 resulted in a decreased [11C]ITDM binding, ranging from - 35.8 ± 8.0 % in pons to - 65.8 ± 3.0 % in thalamus. Displacement was also markedly observed in all tested regions. In addition, in vitro [3H]ITDM binding could be blocked in a dose-dependent manner. The volume of distribution (VT) based on the noninvasive IDIF (VT (IDIF)) showed excellent agreement with the VT values based on the metabolite-corrected plasma input function regardless of the metabolite correction (r2 > 0.943, p < 0.0001). Two-tissue compartmental model (2TCM) was found to be the preferred model and showed optimal agreement with Logan plot (r2 > 0.960, p < 0.0001). A minimum scan duration of 80 min was required for proper parameter estimation. SUV was not reliable (r2 = 0.379, p = 0.0011), unlike the SUV ratio to the SUV of the input function, which showed to be a valid approach. CONCLUSIONS No suitable reference region could be identified for [11C]ITDM as strongly supported by in vivo and in vitro evidence of specific binding in all brain regions. However, by applying appropriate kinetic models, [11C]ITDM PET imaging represents a promising tool to visualize mGluR1 in the mouse brain.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Špela Korat
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA, USA
| | | | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.
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14
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Xiong M, Roshanbin S, Rokka J, Schlein E, Ingelsson M, Sehlin D, Eriksson J, Syvänen S. In vivo imaging of synaptic density with [ 11C]UCB-J PET in two mouse models of neurodegenerative disease. Neuroimage 2021; 239:118302. [PMID: 34174391 DOI: 10.1016/j.neuroimage.2021.118302] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/15/2021] [Accepted: 06/22/2021] [Indexed: 12/16/2022] Open
Abstract
The positron emission tomography (PET) radioligand [11C]UCB-J binds to synaptic vesicle protein 2A (SV2A) and is used to investigate synaptic density in the living brain. Clinical studies have indicated reduced [11C]UCB-J binding in Alzheimer's disease (AD) and Parkinson's disease (PD) brains compared to healthy controls. Still, it is unknown whether [11C]UCB-J PET can visualise synaptic loss in mouse models of these disorders. Such models are essential for understanding disease pathology and for evaluating the effects of novel disease-modifying drug candidates. In the present study, synaptic density in transgenic models of AD (ArcSwe) and PD (L61) was studied using [11C]UCB-J PET. Data were acquired during 60 min after injection, and time-activity curves (TACs) in different brain regions and the left ventricle of the heart were generated based on the dynamic PET images. The [11C]UCB-J brain concentrations were expressed as standardised uptake value (SUV) over time. The area under the SUV curve (AUC), the ratio of AUC in the brain to that in the heart (AUCbrain/blood), and the volume of distribution (VT) obtained by kinetic modelling using the heart TAC as input were compared between transgenic and age-matched wild type (WT) mice. The L61 mice displayed 11-13% lower AUCbrain/blood ratio and brain VT generated by kinetic modeling compared to the control WT mice. In general, also transgenic ArcSwe mice tended to show lower [11C]UCB-J brain exposure than age-matched WT controls, but variation within the different animal groups was high. Older WT mice (18-20 months) showed lower [11C]UCB-J brain exposure than younger WT mice (8-9 months). Together, these data imply that [11C]UCB-J PET reflects synaptic density in mouse models of neurodegeneration and that inter-subject variation is large. In addition, the study suggested that model-independent AUCbrain/blood ratio can be used to evaluate [11C]UCB-J binding as an alternative to full pharmacokinetic modelling.
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Affiliation(s)
- Mengfei Xiong
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Sahar Roshanbin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Johanna Rokka
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Eva Schlein
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Martin Ingelsson
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Dag Sehlin
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden
| | - Jonas Eriksson
- Department of Medicinal Chemistry, Uppsala University, Uppsala SE-751 23, Sweden; PET Centre, Uppsala University Hospital, Uppsala SE-751 85, Sweden
| | - Stina Syvänen
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala SE-751 85, Sweden.
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Glorie D, Verhaeghe J, Miranda A, De Lombaerde S, Stroobants S, Staelens S. Sapap3 deletion causes dynamic synaptic density abnormalities: a longitudinal [ 11C]UCB-J PET study in a model of obsessive-compulsive disorder-like behaviour. EJNMMI Res 2020; 10:140. [PMID: 33185747 PMCID: PMC7666267 DOI: 10.1186/s13550-020-00721-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022] Open
Abstract
Background Currently, the evidence on synaptic abnormalities in neuropsychiatric disorders—including obsessive–compulsive disorder (OCD)—is emerging. The newly established positron emission tomography (PET) ligand ((R)-1-((3-((11)C-methyl-(11)C)pyridin-4-yl)methyl)-4-(3,4,5-trifluorophenyl)pyrrolidin-2-one) ([11C]UCB-J) provides the opportunity to visualize synaptic density changes in vivo, by targeting the synaptic vesicle protein 2A (SV2A). Here, we aim to evaluate such alterations in the brain of the SAP90/PSD-95-associated protein 3 (Sapap3) knockout (ko) mouse model, showing an abnormal corticostriatal neurotransmission resulting in OCD-like behaviour. Methods Longitudinal [11C]UCB-J µPET/CT scans were acquired in Sapap3 ko and wildtype (wt) control mice (n = 9/group) to study SV2A availability. Based on the Logan reference method, we calculated the volume of distribution (VT(IDIF)) for [11C]UCB-J. Both cross-sectional (wt vs. ko) and longitudinal (3 vs. 9 months) volume-of-interest-based statistical analysis and voxel-based statistical parametric mapping were performed. Both [11C]UCB-J ex vivo autoradiography and [3H]UCB-J in vitro autoradiography were used for the validation of the µPET data. Results At the age of 3 months, Sapap3 ko mice are already characterized by a significantly lower SV2A availability compared to wt littermates (i.a. cortex − 12.69%, p < 0.01; striatum − 14.12%, p < 0.001, thalamus − 13.11%, p < 0.001, and hippocampus − 12.99%, p < 0.001). Healthy ageing in control mice was associated with a diffuse and significant (p < 0.001) decline throughout the brain, whereas in Sapap3 ko mice this decline was more confined to the corticostriatal level. A strong linear relationship (p < 0.0001) was established between the outcome parameters of [11C]UCB-J µPET and [11C]UCB-J ex vivo autoradiography, while such relationship was absent for [3H]UCB-J in vitro autoradiography. Conclusions [11C]UCB-J PET is a potential marker for synaptic density deficits in the Sapap3 ko mouse model for OCD, parallel to disease progression. Our data suggest that [11C]UCB-J ex vivo autoradiography is a suitable proxy for [11C]UCB-J PET data in mice.
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Affiliation(s)
- Dorien Glorie
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium
| | - Stef De Lombaerde
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.
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16
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Bertoglio D, Verhaeghe J, Miranda A, Kertesz I, Cybulska K, Korat Š, Wyffels L, Stroobants S, Mrzljak L, Dominguez C, Liu L, Skinbjerg M, Munoz-Sanjuan I, Staelens S. Validation and noninvasive kinetic modeling of [ 11C]UCB-J PET imaging in mice. J Cereb Blood Flow Metab 2020; 40:1351-1362. [PMID: 31307287 PMCID: PMC7232782 DOI: 10.1177/0271678x19864081] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Synaptic pathology is associated with several brain disorders, thus positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) using the radioligand [11C]UCB-J may provide a tool to measure synaptic alterations. Given the pivotal role of mouse models in understanding neuropsychiatric and neurodegenerative disorders, this study aims to validate and characterize [11C]UCB-J in mice. We performed a blocking study to verify the specificity of the radiotracer to SV2A, examined kinetic models using an image-derived input function (IDIF) for quantification of the radiotracer, and investigated the in vivo metabolism. Regional TACs during baseline showed rapid uptake of [11C]UCB-J into the brain. Pretreatment with levetiracetam confirmed target engagement in a dose-dependent manner. VT (IDIF) values estimated with one- and two-tissue compartmental models (1TCM and 2TCM) were highly comparable (r=0.999, p < 0.0001), with 1TCM performing better than 2TCM for K1 (IDIF). A scan duration of 60 min was sufficient for reliable VT (IDIF) and K1 (IDIF) estimations. In vivo metabolism of [11C]UCB-J was relatively rapid, with a parent fraction of 22.5 ± 4.2% at 15 min p.i. In conclusion, our findings show that [11C]UCB-J selectively binds to SV2A with optimal kinetics in the mouse representing a promising tool to noninvasively quantify synaptic density in comparative or therapeutic studies in neuropsychiatric and neurodegenerative disorder models.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Istvan Kertesz
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Klaudia Cybulska
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Špela Korat
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA, USA
| | | | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
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Progression of obsessive compulsive disorder-like grooming in Sapap3 knockout mice: A longitudinal [ 11C]ABP688 PET study. Neuropharmacology 2020; 177:108160. [PMID: 32454126 DOI: 10.1016/j.neuropharm.2020.108160] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 03/18/2020] [Accepted: 05/21/2020] [Indexed: 01/23/2023]
Abstract
We aimed to evaluate [3-(6-methyl-pyridin-2-ylethynyl)-cyclohex-2-enone-0-11C-methyloxime] ([11C]ABP688) small animal positron emission tomography (μPET) as a biomarker to visualize possible longitudinal changes in metabotropic glutamate receptor 5 (mGluR5) availability in the brain of SAP90/PSD-95 associated protein 3 (Sapap3) knockout (ko) mice, showing obsessive compulsive disorder (OCD)-like behavior. METHODS Alongside the assessment of grooming, we performed [11C]ABP688 μPET/CT imaging in wildtype (wt; n=10) and ko (n=11) mice both at 3 and 9 months. Using the simplified reference tissue method (SRTM), the nondisplaceable binding potential (BPND) was calculated representing the in vivo availability of the metabotropic glutamate receptor 5 (mGluR5) in the brain with the cerebellum as a reference region. Longitudinal voxel-based statistical parametric mapping (SPM) was performed on BPND images. Results were verified using [11C]ABP688 ex vivo autoradiography, [3H]ABP688 in vitro autoradiography, and mGluR5 immunohistochemistry. RESULTS Cross-sectional comparisons revealed significantly increased grooming parameters in ko animals, at both time points. A significant longitudinal increase in % grooming duration (+268.25%; p<0.05) reflected aggravation of this behavior in ko mice. [11C]ABP688 μPET revealed significantly lower mGluR5 availability in the cortex, striatum, hippocampus, and amygdala of ko mice at both ages. A significant longitudinal BPND decline was present for ko mice (p<0.01: cortex -17.14%, striatum -19.82%, amygdala -23.57%; p<0.05: hippocampus -15.53%), which was confirmed by SPM (p<0.01). CONCLUSION Sapap3 ko mice show a decline in mGluR5 availability in OCD relevant brain regions parallel to the worsening of OCD-like behavior. This demonstrates a potential role for [11C]ABP688 PET as a biomarker to monitor disease progression in vivo.
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Longitudinal mouse-PET imaging: a reliable method for estimating binding parameters without a reference region or blood sampling. Eur J Nucl Med Mol Imaging 2020; 47:2589-2601. [PMID: 32211931 PMCID: PMC7515949 DOI: 10.1007/s00259-020-04755-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/03/2020] [Indexed: 01/06/2023]
Abstract
Abstract Longitudinal mouse PET imaging is becoming increasingly popular due to the large number of transgenic and disease models available but faces challenges. These challenges are related to the small size of the mouse brain and the limited spatial resolution of microPET scanners, along with the small blood volume making arterial blood sampling challenging and impossible for longitudinal studies. The ability to extract an input function directly from the image would be useful for quantification in longitudinal small animal studies where there is no true reference region available such as TSPO imaging. Methods Using dynamic, whole-body 18F-DPA-714 PET scans (60 min) in a mouse model of hippocampal sclerosis, we applied a factor analysis (FA) approach to extract an image-derived input function (IDIF). This mouse-specific IDIF was then used for 4D-resolution recovery and denoising (4D-RRD) that outputs a dynamic image with better spatial resolution and noise properties, and a map of the total volume of distribution (VT) was obtained using a basis function approach in a total of 9 mice with 4 longitudinal PET scans each. We also calculated percent injected dose (%ID) with and without 4D-RRD. The VT and %ID parameters were compared to quantified ex vivo autoradiography using regional correlations of the specific binding from autoradiography against VT and %ID parameters. Results The peaks of the IDIFs were strongly correlated with the injected dose (Pearson R = 0.79). The regional correlations between the %ID estimates and autoradiography were R = 0.53 without 4D-RRD and 0.72 with 4D-RRD over all mice and scans. The regional correlations between the VT estimates and autoradiography were R = 0.66 without 4D-RRD and 0.79 with application of 4D-RRD over all mice and scans. Conclusion We present a FA approach for IDIF extraction which is robust, reproducible and can be used in quantification methods for resolution recovery, denoising and parameter estimation. We demonstrated that the proposed quantification method yields parameter estimates closer to ex vivo measurements than semi-quantitative methods such as %ID and is immune to tracer binding in tissue unlike reference tissue methods. This approach allows for accurate quantification in longitudinal PET studies in mice while avoiding repeated blood sampling. Electronic supplementary material The online version of this article (10.1007/s00259-020-04755-5) contains supplementary material, which is available to authorized users.
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He X, Wedekind F, Kroll T, Oskamp A, Beer S, Drzezga A, Ermert J, Neumaier B, Bauer A, Elmenhorst D. Image-Derived Input Functions for Quantification of A 1 Adenosine Receptors Availability in Mice Brains Using PET and [ 18F]CPFPX. Front Physiol 2020; 10:1617. [PMID: 32063864 PMCID: PMC7000659 DOI: 10.3389/fphys.2019.01617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/23/2019] [Indexed: 12/28/2022] Open
Abstract
Purpose In vivo imaging for the A1 adenosine receptors (A1ARs) with positron emission tomography (PET) using 8-cyclopentyl-3-(3-[18F]fluoropropyl)-1-propylxan- thine ([18F]CPFPX) has become an important tool for studying physiological processes quantitatively in mice. However, the measurement of arterial input functions (AIFs) on mice is a method with restricted applicability because of the small total blood volume and the related difficulties in withdrawing blood. Therefore, the aim of this study was to extract an appropriate [18F]CPFPX image-derived input function (IDIF) from dynamic PET images of mice. Procedures In this study, five mice were scanned with [18F]CPFPX for 60 min. Arterial blood samples (n = 7 per animal) were collected from the femoral artery and corrected for metabolites. To generate IDIFs, three different approaches were selected: (A) volume of interest (VOI) placed over the heart (cube, 10 mm); (B) VOI set over abdominal vena cava/aorta region with a cuboid (5 × 5 × 15 mm); and (C) with 1 × 1 × 1 mm voxels on five consecutive slices. A calculated scaling factor (α) was used to correct for partial volume effect; the method of obtaining the total metabolite correction of [18F]CPFPX for IDIFs was developed. Three IDIFs were validated by comparison with AIF. Validation included the following: visual performance; computing area under the curve (AUC) ratios (IDIF/AIF) of whole-blood curves and parent curves; and the mean distribution volume (VT) ratios (IDIF/AIF) of A1ARs calculated by Logan plot and two-tissue compartment model. Results Compared with the AIF, the IDIF with VOI over heart showed the best performance among the three IDIFs after scaling by 1.77 (α) in terms of visual analysis, AUC ratios (IDIF/AIF; whole-blood AUC ratio, 1.03 ± 0.06; parent curve AUC ratio, 1.01 ± 0.10) and VT ratios (IDIF/AIF; Logan VT ratio, 1.00 ± 0.17; two-tissue compartment model VT ratio, 1.00 ± 0.13) evaluation. The A1ARs distribution of average parametric images was in good accordance to autoradiography of the mouse brain. Conclusion The proposed study provides evidence that IDIF with VOI over heart can replace AIF effectively for quantification of A1ARs using PET and [18F]CPFPX in mice brains.
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Affiliation(s)
- Xuan He
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany.,Department of Neurophysiology, Institute of Zoology (Bio-II), RWTH Aachen University, Aachen, Germany
| | - Franziska Wedekind
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany
| | - Tina Kroll
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany
| | - Angela Oskamp
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany
| | - Simone Beer
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany
| | - Alexander Drzezga
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany.,Department of Nuclear Medicine, University Hospital of Cologne, Cologne, Germany
| | - Johannes Ermert
- Institut für Neurowissenschaften und Medizin (INM-5), Forschungszentrum Jülich, Jülich, Germany
| | - Bernd Neumaier
- Institut für Neurowissenschaften und Medizin (INM-5), Forschungszentrum Jülich, Jülich, Germany
| | - Andreas Bauer
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany.,Neurological Department, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - David Elmenhorst
- Institut für Neurowissenschaften und Medizin (INM-2), Forschungszentrum Jülich, Jülich, Germany.,Division of Medical Psychology, University of Bonn, Bonn, Germany
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Bertoglio D, Verhaeghe J, Korat Š, Miranda A, Cybulska K, Wyffels L, Stroobants S, Mrzljak L, Dominguez C, Skinbjerg M, Liu L, Munoz-Sanjuan I, Staelens S. Elevated Type 1 Metabotropic Glutamate Receptor Availability in a Mouse Model of Huntington's Disease: a Longitudinal PET Study. Mol Neurobiol 2020; 57:2038-2047. [PMID: 31912442 PMCID: PMC7118044 DOI: 10.1007/s12035-019-01866-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/22/2019] [Indexed: 12/11/2022]
Abstract
Impairment of group I metabotropic glutamate receptors (mGluRs) results in altered glutamate signalling, which is associated with several neurological disorders including Huntington’s Disease (HD), an autosomal neurodegenerative disease. In this study, we assessed in vivo pathological changes in mGluR1 availability in the Q175DN mouse model of HD using longitudinal positron emission tomography (PET) imaging with the radioligand [11C]ITDM. Ninety-minute dynamic PET imaging scans were performed in 22 heterozygous (HET) Q175DN mice and 22 wild-type (WT) littermates longitudinally at 6, 12, and 16 months of age. Analyses of regional volume of distribution with an image-derived input function (VT (IDIF)) and voxel-wise parametric VT (IDIF) maps were performed to assess differences between genotypes. Post-mortem evaluation at 16 months was done to support in vivo findings. [11C]ITDM VT (IDIF) quantification revealed higher mGluR1 availability in the brain of HET mice compared to WT littermates (e.g. cerebellum: + 15.0%, + 17.9%, and + 17.6% at 6, 12, and 16 months, respectively; p < 0.001). In addition, an age-related decline in [11C]ITDM binding independent of genotype was observed between 6 and 12 months. Voxel-wise analysis of parametric maps and post-mortem quantifications confirmed the elevated mGluR1 availability in HET mice compared to WT littermates. In conclusion, in vivo measurement of mGluR1 availability using longitudinal [11C]ITDM PET imaging demonstrated higher [11C]ITDM binding in extra-striatal brain regions during the course of disease in the Q175DN mouse model.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Špela Korat
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Klaudia Cybulska
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | | | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA, USA
| | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.
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Bertoglio D, Verhaeghe J, Kosten L, Thomae D, Van der Linden A, Stroobants S, Wityak J, Dominguez C, Mrzljak L, Staelens S. MR-based spatial normalization improves [18F]MNI-659 PET regional quantification and detectability of disease effect in the Q175 mouse model of Huntington's disease. PLoS One 2018; 13:e0206613. [PMID: 30365550 PMCID: PMC6203386 DOI: 10.1371/journal.pone.0206613] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 10/16/2018] [Indexed: 11/19/2022] Open
Abstract
The positron emission tomography (PET) tracer [18F]MNI-659, selective for phosphodiesterase 10A (PDE10A), is a promising tool to assess an early biomarker for Huntington’s disease (HD). In this study we investigated [18F]MNI-659 uptake in the Q175 mouse model of HD. Given the focal striatal distribution of PDE10A as well as the striatal atrophy occurring in HD, the spatial normalization approach applied during the processing could sensibly affect the accuracy of the regional quantification. We compared the use of a magnetic resonance images (MRI) template based on individual MRI over a PET and CT templates for regional quantification and spatial normalization of [18F]MNI-659 PET images. We performed [18F]MNI-659 PET imaging in six months old heterozygous (HET) Q175 mice and wild-type (WT) littermates, followed by X-ray computed tomography (CT) scan. In the same week, individual T2-weighted MRI were acquired. Spatial normalization and regional quantification of the PET/CT images was performed on MRI, [18F]MNI-659 PET, or CT template and compared to binding potential (BPND) using volumes manually delineated on the individual MR images. Striatal volume was significantly reduced in HET mice (-7.7%, p<0.0001) compared to WT littermates. [18F]MNI-659 BPND in striatum of HET animals was significantly reduced (p<0.0001) when compared to WT littermates using all three templates. However, BPND values were significantly higher for HET mice using the PET template compared to the MRI and CT ones (p<0.0001), with an overestimation at lower activities. On the other hand, the CT template spatial normalization introduced larger variability reducing the effect size. The PET and CT template-based approaches resulted in a lower accuracy in BPND quantification with consequent decrease in the detectability of disease effect. This study demonstrates that for [18F]MNI-659 brain PET imaging in mice the use of an MRI-based spatial normalization is recommended to achieve accurate quantification and fully exploit the detectability of disease effect.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Lauren Kosten
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - David Thomae
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - John Wityak
- CHDI Foundation, Princeton, NJ, United States of America
| | | | | | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
- * E-mail:
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Bertoglio D, Kosten L, Verhaeghe J, Thomae D, Wyffels L, Stroobants S, Wityak J, Dominguez C, Mrzljak L, Staelens S. Longitudinal Characterization of mGluR5 Using 11C-ABP688 PET Imaging in the Q175 Mouse Model of Huntington Disease. J Nucl Med 2018; 59:1722-1727. [DOI: 10.2967/jnumed.118.210658] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/22/2018] [Indexed: 11/16/2022] Open
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