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Herranz E, Treaba CA, Barletta VT, Mehndiratta A, Ouellette R, Sloane JA, Ionete C, Babu S, Mastantuono M, Magon S, Loggia ML, Makary MM, Hooker JM, Catana C, Kinkel RP, Nicholas R, Klawiter EC, Magliozzi R, Mainero C. Characterization of cortico-meningeal translocator protein expression in multiple sclerosis. Brain 2024; 147:2566-2578. [PMID: 38289855 PMCID: PMC11224595 DOI: 10.1093/brain/awae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 02/01/2024] Open
Abstract
Compartmentalized meningeal inflammation is thought to represent one of the key players in the pathogenesis of cortical demyelination in multiple sclerosis. PET targeting the 18 kDa mitochondrial translocator protein (TSPO) is a molecular-specific approach to quantifying immune cell-mediated density in the cortico-meningeal tissue compartment in vivo. This study aimed to characterize cortical and meningeal TSPO expression in a heterogeneous cohort of multiple sclerosis cases using in vivo simultaneous MR-PET with 11C-PBR28, a second-generation TSPO radioligand, and ex vivo immunohistochemistry. Forty-nine multiple sclerosis patients (21 with secondary progressive and 28 with relapsing-remitting multiple sclerosis) with mixed or high affinity binding for 11C-PBR28 underwent 90-min 11C-PBR28 simultaneous MR-PET. Tracer binding was measured using 60-90 min normalized standardized uptake value ratios sampled at mid-cortical depth and ∼3 mm above the pial surface. Data in multiple sclerosis patients were compared to 21 age-matched healthy controls. To characterize the nature of 11C-PBR28 PET uptake, the meningeal and cortical lesion cellular expression of TSPO was further described in post-mortem brain tissue from 20 cases with secondary progressive multiple sclerosis and five age-matched healthy donors. Relative to healthy controls, patients with multiple sclerosis exhibited abnormally increased TSPO signal in the cortex and meningeal tissue, diffusively in progressive disease and more localized in relapsing-remitting multiple sclerosis. In multiple sclerosis, increased meningeal TSPO levels were associated with increased Expanded Disability Status Scale scores (P = 0.007, by linear regression). Immunohistochemistry, validated using in situ sequencing analysis, revealed increased TSPO expression in the meninges and adjacent subpial cortical lesions of post-mortem secondary progressive multiple sclerosis cases relative to control tissue. In these cases, increased TSPO expression was related to meningeal inflammation. Translocator protein immunostaining was detected on meningeal MHC-class II+ macrophages and cortical-activated MHC-class II+ TMEM119+ microglia. In vivo arterial blood data and neuropathology showed that endothelial binding did not significantly account for increased TSPO cortico-meningeal expression in multiple sclerosis. Our findings support the use of TSPO-PET in multiple sclerosis for imaging in vivo inflammation in the cortico-meningeal brain tissue compartment and provide in vivo evidence implicating meningeal inflammation in the pathogenesis of the disease.
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Affiliation(s)
- Elena Herranz
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Constantina A Treaba
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Valeria T Barletta
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Ambica Mehndiratta
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Russell Ouellette
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Department of Clinical Neuroscience, Karolinska Institutet, 141 86 Stockholm, Sweden
- Department of Radiology, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Jacob A Sloane
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Carolina Ionete
- Department of Neurology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Suma Babu
- Harvard Medical School, Boston, MA 02115, USA
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Marina Mastantuono
- Neurology Section, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona 53593, Italy
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel 4058, Switzerland
| | - Stefano Magon
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel 4058, Switzerland
| | - Marco L Loggia
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Meena M Makary
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
- Systems and Biomedical Engineering Department, Faculty of Engineering, Cairo University, Giza 12613, Egypt
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Ciprian Catana
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Revere P Kinkel
- University of California San Diego, Department of Neuroscience, San Diego, CA 92093, USA
| | - Richard Nicholas
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London SW7 2BX, UK
| | - Eric C Klawiter
- Harvard Medical School, Boston, MA 02115, USA
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Roberta Magliozzi
- Neurology Section, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona 53593, Italy
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London SW7 2BX, UK
| | - Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Harvard Medical School, Boston, MA 02115, USA
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2
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Kuznetsov IA, Kuznetsov AV. Effect of mitochondrial circulation on mitochondrial age density distribution. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3770. [PMID: 37688421 PMCID: PMC10841163 DOI: 10.1002/cnm.3770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/02/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023]
Abstract
Recent publications report that although the mitochondria population in an axon can be quickly replaced by a combination of retrograde and anterograde axonal transport (often within less than 24 hours), the axon contains much older mitochondria. This suggests that not all mitochondria that reach the soma are degraded and that some are recirculating back into the axon. To explain this, we developed a model that simulates mitochondria distribution when a portion of mitochondria that return to the soma are redirected back to the axon rather than being destroyed in somatic lysosomes. Utilizing the developed model, we studied how the percentage of returning mitochondria affects the mean age and age density distributions of mitochondria at different distances from the soma. We also investigated whether turning off the mitochondrial anchoring switch can reduce the mean age of mitochondria. For this purpose, we studied the effect of reducing the value of a parameter that characterizes the probability of mitochondria transition to the stationary (anchored) state. The reduction in mitochondria mean age observed when the anchoring probability is reduced suggests that some injured neurons may be saved if the percentage of stationary mitochondria is decreased. The replacement of possibly damaged stationary mitochondria with newly synthesized ones may restore the energy supply in an injured axon. We also performed a sensitivity study of the mean age of stationary mitochondria to the parameter that determines what portion of mitochondria re-enter the axon and the parameter that determines the probability of mitochondria transition to the stationary state. The sensitivity of the mean age of stationary mitochondria to the mitochondria stopping probability increases linearly with the number of compartments in the axon. High stopping probability in long axons can significantly increase mitochondrial age.
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Affiliation(s)
- Ivan A Kuznetsov
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrey V Kuznetsov
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, USA
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3
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Oh J, Airas L, Harrison D, Järvinen E, Livingston T, Lanker S, Malik RA, Okuda DT, Villoslada P, de Vries HE. Neuroimaging to monitor worsening of multiple sclerosis: advances supported by the grant for multiple sclerosis innovation. Front Neurol 2023; 14:1319869. [PMID: 38107636 PMCID: PMC10722910 DOI: 10.3389/fneur.2023.1319869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/13/2023] [Indexed: 12/19/2023] Open
Abstract
Key unmet needs in multiple sclerosis (MS) include detection of early pathology, disability worsening independent of relapses, and accurate monitoring of treatment response. Collaborative approaches to address these unmet needs have been driven in part by industry-academic networks and initiatives such as the Grant for Multiple Sclerosis Innovation (GMSI) and Multiple Sclerosis Leadership and Innovation Network (MS-LINK™) programs. We review the application of recent advances, supported by the GMSI and MS-LINK™ programs, in neuroimaging technology to quantify pathology related to central pathology and disease worsening, and potential for their translation into clinical practice/trials. GMSI-supported advances in neuroimaging methods and biomarkers include developments in magnetic resonance imaging, positron emission tomography, ocular imaging, and machine learning. However, longitudinal studies are required to facilitate translation of these measures to the clinic and to justify their inclusion as endpoints in clinical trials of new therapeutics for MS. Novel neuroimaging measures and other biomarkers, combined with artificial intelligence, may enable accurate prediction and monitoring of MS worsening in the clinic, and may also be used as endpoints in clinical trials of new therapies for MS targeting relapse-independent disease pathology.
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Affiliation(s)
- Jiwon Oh
- Division of Neurology, St. Michael’s Hospital, Department of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Laura Airas
- Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Daniel Harrison
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
- Baltimore VA Medical Center, VA Maryland Healthcare System, Baltimore, MD, United States
| | - Elina Järvinen
- Neurology and Immunology, Medical Unit N&I, Merck OY (an affiliate of Merck KGaA), Espoo, Finland
| | - Terrie Livingston
- Patient Solutions and Center of Excellence Strategic Engagement, EMD Serono, Inc., Rockland, MA, United States
| | - Stefan Lanker
- Neurology & Immunology, US Medical Affairs, EMD Serono Research & Development Institute, Inc., (an affiliate of Merck KGaA), Billerica, MA, United States
| | - Rayaz A. Malik
- Weill Cornell Medicine-Qatar, Research Division, Doha, Qatar
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Darin T. Okuda
- Department of Neurology, Neuroinnovation Program, Multiple Sclerosis and Neuroimmunology Imaging Program, Clinical Center for Multiple Sclerosis, UT Southwestern Medical Center, Dallas, TX, United States
| | - Pablo Villoslada
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
| | - Helga E. de Vries
- MS Center Amsterdam, Department of Molecular Cell Biology and Immunology, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam University Medical Centers (Amsterdam UMC), Location VUmc, Amsterdam, Netherlands
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4
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Roussakis AA, Gennaro M, Gordon MF, Reilmann R, Borowsky B, Rynkowski G, Lao-Kaim NP, Papoutsou Z, Savola JM, Hayden MR, Owen DR, Kalk N, Lingford-Hughes A, Gunn RN, Searle G, Tabrizi SJ, Piccini P. A PET-CT study on neuroinflammation in Huntington's disease patients participating in a randomized trial with laquinimod. Brain Commun 2023; 5:fcad084. [PMID: 37020532 PMCID: PMC10069663 DOI: 10.1093/braincomms/fcad084] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/19/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Microglia activation, an indicator of central nervous system inflammation, is believed to contribute to the pathology of Huntington's disease. Laquinimod is capable of regulating microglia. By targeting the translocator protein, 11C-PBR28 PET-CT imaging can be used to assess the state of regional gliosis in vivo and explore the effects of laquinimod treatment. This study relates to the LEGATO-HD, multi-centre, double-blinded, Phase 2 clinical trial with laquinimod (US National Registration: NCT02215616). Fifteen patients of the UK LEGATO-HD cohort (mean age: 45.2 ± 7.4 years; disease duration: 5.6 ± 3.0 years) were treated with laquinimod (0.5 mg, N = 4; 1.0 mg, N = 6) or placebo (N = 5) daily. All participants had one 11C-PBR28 PET-CT and one brain MRI scan before laquinimod (or placebo) and at the end of treatment (12 months apart). PET imaging data were quantified to produce 11C-PBR28 distribution volume ratios. These ratios were calculated for the caudate and putamen using the reference Logan plot with the corpus callosum as the reference region. Partial volume effect corrections (Müller-Gartner algorithm) were applied. Differences were sought in Unified Huntington's Disease Rating Scale scores and regional distribution volume ratios between baseline and follow-up and between the two treatment groups (laquinimod versus placebo). No significant change in 11C-PBR28 distribution volume ratios was found post treatment in the caudate and putamen for both those treated with laquinimod (N = 10) and those treated with placebo (N = 5). Over time, the patients treated with laquinimod did not show a significant clinical improvement. Data from the 11C-PBR28 PET-CT study indicate that laquinimod may not have affected regional translocator protein expression and clinical performance over the studied period.
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Affiliation(s)
| | - Marta Gennaro
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | | | | | | | - Nicholas P Lao-Kaim
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Zoe Papoutsou
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children’s Hospital and Research Institute, University of British Columbia, Vancouver V5Z 4H4, Canada
| | - David R Owen
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Nicola Kalk
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Anne Lingford-Hughes
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Roger N Gunn
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
- Invicro, Hammersmith Hospital,, London W12 0NN, UK
| | | | - Sarah J Tabrizi
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Paola Piccini
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
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Abstract
PURPOSE OF REVIEW Microglia normally protects the central nervous system (CNS) against insults. However, their persistent activation in multiple sclerosis (MS) contributes to injury. Here, we review microglia activation in MS and their detection using positron emission tomography (PET). RECENT FINDINGS During lesion evolution and the progression of MS, microglia activity may contribute to neurotoxicity through the release of pro-inflammatory cytokines, reactive oxidative species, proteases and glutamate. A means to detect and monitor microglia activation in individuals living with MS is provided by positron emission tomography (PET) imaging using the mitochondrial 18-kDa translocator protein (TSPO) ligand. TSPO PET imaging shows increased microglial activation within the normal appearing white matter that precedes radiological signs of neurodegeneration measured by T2 lesion enlargement. PET-detected microglia activation increases with progression of MS. These findings demand the use of CNS penetrant inhibitors that affect microglia. Such therapies may include hydroxychloroquine that is recently reported in a small study to reduce the expected progression in primary progressive MS, and Bruton's tyrosine kinase inhibitors for which there are now eleven Phase 3 registered trials in MS. SUMMARY Microglial activation drives injury in MS. PET imaging with microglia-specific ligands offer new insights into progression of MS and as a monitor for treatment responses.
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6
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Young JW, Barback CV, Stolz LA, Groman SM, Vera DR, Hoh C, Kotta KK, Minassian A, Powell SB, Brody AL. MicroPET evidence for a hypersensitive neuroinflammatory profile of gp120 mouse model of HIV. Psychiatry Res Neuroimaging 2022; 321:111445. [PMID: 35101828 DOI: 10.1016/j.pscychresns.2022.111445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 02/07/2023]
Abstract
Despite increased survivability for people living with HIV (PLWH), HIV-related cognitive deficits persist. Determining biological mechanism(s) underlying abnormalities is critical to minimize the long-term impact of HIV. Positron emission tomography (PET) studies reveal that PLWH exhibit elevated neuroinflammation, potentially contributing to these problems. PLWH are hypersensitive to environmental insults that drive elevated inflammatory profiles. Gp120 is an envelope glycoprotein exposed on the surface of the HIV envelope which enables HIV entry into a cell contributing to HIV-related neurotoxicity. In vivo evidence for mice overexpressing gp120 (transgenic) mice exhibiting neuroinflammation remains unclear. Here, we conducted microPET imaging in gp120 transgenic and wildtype mice, using the radiotracer [(18)F]FEPPA (binds to the translocator protein expressed by activated microglial serving as a neuroinflammatory marker). Imaging was performed at baseline and 24 h after lipopolysaccharide (LPS; 5 mg/kg) treatment (endotoxin that triggers an immune response). Gp120 transgenic mice exhibited elevated [(18F)]FEPPA in response to LPS vs. wildtype mice throughout the brain including dorsal and ventral striata, hypothalamus, and hippocampus. Gp120 transgenic mice are hypersensitive to environmental inflammatory insults, consistent with PLWH, measurable in vivo. It remains to-be-determined whether this heightened sensitivity is connected to the behavioral abnormalities of these mice or sensitive to any treatments.
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Affiliation(s)
- Jared W Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Christopher V Barback
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Louise A Stolz
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA
| | - Stephanie M Groman
- Department of Neuroscience, Medical Discovery Team on Addiction, University of Minnesota
| | - David R Vera
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Carl Hoh
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Kishore K Kotta
- Department of Radiology, University of California, San Diego, La Jolla California; UCSD In Vivo Cancer and Molecular Imaging Program
| | - Arpi Minassian
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Susan B Powell
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Arthur L Brody
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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7
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Gouilly D, Saint-Aubert L, Ribeiro MJ, Salabert AS, Tauber C, Péran P, Arlicot N, Pariente J, Payoux P. Neuroinflammation PET imaging of the translocator protein (TSPO) in Alzheimer's disease: an update. Eur J Neurosci 2022; 55:1322-1343. [PMID: 35083791 DOI: 10.1111/ejn.15613] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/28/2022]
Abstract
Neuroinflammation is a significant contributor to Alzheimer's disease (AD). Until now, PET imaging of the translocator protein (TSPO) has been widely used to depict the neuroimmune endophenotype of AD. The aim of this review was to provide an update to the results from 2018 and to advance the characterization of the biological basis of TSPO imaging in AD by re-examining TSPO function and expression and the methodological aspects of interest. Although the biological basis of the TSPO PET signal is obviously related to microglia and astrocytes in AD, the observed process remains uncertain and might not be directly related to neuroinflammation. Further studies are required to re-examine the cellular significance underlying a variation in the PET signal in AD and how it can be impacted by a disease-modifying treatment.
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Affiliation(s)
- Dominique Gouilly
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Laure Saint-Aubert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Maria-Joao Ribeiro
- Department of Nuclear Medicine, CHU, Tours, France.,UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Anne-Sophie Salabert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
| | | | - Patrice Péran
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Jérémie Pariente
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Cognitive Neurology, Epilepsy and Movement Disorders, CHU, Toulouse, France.,Center of Clinical Investigations (CIC1436), CHU, Toulouse, France
| | - Pierre Payoux
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
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8
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Wimberley C, Lavisse S, Hillmer A, Hinz R, Turkheimer F, Zanotti-Fregonara P. Kinetic modeling and parameter estimation of TSPO PET imaging in the human brain. Eur J Nucl Med Mol Imaging 2021; 49:246-256. [PMID: 33693967 PMCID: PMC8712306 DOI: 10.1007/s00259-021-05248-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/07/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE Translocator protein 18-kDa (TSPO) imaging with positron emission tomography (PET) is widely used in research studies of brain diseases that have a neuro-immune component. Quantification of TSPO PET images, however, is associated with several challenges, such as the lack of a reference region, a genetic polymorphism affecting the affinity of the ligand for TSPO, and a strong TSPO signal in the endothelium of the brain vessels. These challenges have created an ongoing debate in the field about which type of quantification is most useful and whether there is an appropriate simplified model. METHODS This review focuses on the quantification of TSPO radioligands in the human brain. The various methods of quantification are summarized, including the gold standard of compartmental modeling with metabolite-corrected input function as well as various alternative models and non-invasive approaches. Their advantages and drawbacks are critically assessed. RESULTS AND CONCLUSIONS Researchers employing quantification methods for TSPO should understand the advantages and limitations associated with each method. Suggestions are given to help researchers choose between these viable alternative methods.
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Affiliation(s)
| | - Sonia Lavisse
- CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, 92265, Fontenay-aux-Roses, France
| | - Ansel Hillmer
- Departments of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
- Departments of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, USA
| | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, M20 3LJ, UK
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, Centre for Neuroimaging Sciences, King's College London, De Crespigny Park, London, SE5 8AF, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, UK
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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9
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Schubert J, Tonietto M, Turkheimer F, Zanotti-Fregonara P, Veronese M. Supervised clustering for TSPO PET imaging. Eur J Nucl Med Mol Imaging 2021; 49:257-268. [PMID: 33779770 PMCID: PMC8712290 DOI: 10.1007/s00259-021-05309-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE This technical note seeks to act as a practical guide for implementing a supervised clustering algorithm (SVCA) reference region approach and to explain the main strengths and limitations of the technique in the context of 18-kilodalton translocator protein (TSPO) positron emission tomography (PET) studies in experimental medicine. BACKGROUND TSPO PET is the most widely used imaging technique for studying neuroinflammation in vivo in humans. Quantifying neuroinflammation with PET can be a challenging and invasive procedure, especially in frail patients, because it often requires blood sampling from an arterial catheter. A widely used alternative to arterial sampling is SVCA, which identifies the voxels with minimal specific binding in the PET images, thus extracting a pseudo-reference region for non-invasive quantification. Unlike other reference region approaches, SVCA does not require specification of an anatomical reference region a priori, which alleviates the limitation of TSPO contamination in anatomically-defined reference regions in individuals with underlying inflammatory processes. Furthermore, SVCA can be applied to any TSPO PET tracer across different neurological and neuropsychiatric conditions, providing noninvasivequantification of TSPO expression. METHODS We provide an overview of the development of SVCA as well as step-by-step instructions for implementing SVCA with suggestions for specific settings. We review the literature on SVCAapplications using first- and second- generation TSPO PET tracers and discuss potential clinically relevant limitations and applications. CONCLUSIONS The correct implementation of SVCA can provide robust and reproducible estimates of brain TSPO expression. This review encourages the standardisation of SVCA methodology in TSPO PET analysis, ultimately aiming to improve replicability and comparability across study sites.
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Affiliation(s)
- Julia Schubert
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Matteo Tonietto
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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10
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Zinnhardt B, Roncaroli F, Foray C, Agushi E, Osrah B, Hugon G, Jacobs AH, Winkeler A. Imaging of the glioma microenvironment by TSPO PET. Eur J Nucl Med Mol Imaging 2021; 49:174-185. [PMID: 33721063 DOI: 10.1007/s00259-021-05276-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
Gliomas are highly dynamic and heterogeneous tumours of the central nervous system (CNS). They constitute the most common neoplasm of the CNS and the second most common cause of death from intracranial disease after stroke. The advances in detailing the genetic profile of paediatric and adult gliomas along with the progress in MRI and PET multimodal molecular imaging technologies have greatly improved prognostic stratification of patients with glioma and informed on treatment decisions. Amino acid PET has already gained broad clinical application in the study of gliomas. PET imaging targeting the translocator protein (TSPO) has recently been applied to decipher the heterogeneity and dynamics of the tumour microenvironment (TME) and its various cellular components especially in view of targeted immune therapies with the goal to delineate pro- and anti-glioma immune cell modulation. The current review provides a comprehensive overview on the historical developments of TSPO PET for gliomas and summarizes the most relevant experimental and clinical data with regard to the assessment and quantification of various cellular components with the TME of gliomas by in vivo TSPO PET imaging.
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Affiliation(s)
- Bastian Zinnhardt
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
- Biomarkers and Translational Technologies, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Federico Roncaroli
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Claudia Foray
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
| | - Erjon Agushi
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Bahiya Osrah
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, Manchester, UK
| | - Gaëlle Hugon
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Université Paris-Saclay, Orsay, France
| | - Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-University Münster (WWU), Münster, Germany
- Department of Geriatrics and Neurology, Johanniter Hospital, Bonn, Germany
| | - Alexandra Winkeler
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Université Paris-Saclay, Orsay, France.
- CEA, DRF, JOLIOT, SHFJ, Orsay, France.
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11
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Charles A, Nwaobi SE, Goadsby P. Inflammation in migraine…or not…: A critical evaluation of the evidence. Headache 2021; 61:1575-1578. [PMID: 34806166 DOI: 10.1111/head.14224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 01/15/2023]
Affiliation(s)
- Andrew Charles
- UCLA Goldberg Migraine Program, Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Sinifunanya E Nwaobi
- UCLA Goldberg Migraine Program, Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Peter Goadsby
- UCLA Goldberg Migraine Program, Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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12
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Sander CY, Bovo S, Torrado-Carvajal A, Albrecht D, Deng H, Napadow V, Price JC, Hooker JM, Loggia ML. [ 11C]PBR28 radiotracer kinetics are not driven by alterations in cerebral blood flow. J Cereb Blood Flow Metab 2021; 41:3069-3084. [PMID: 34159823 PMCID: PMC8756484 DOI: 10.1177/0271678x211023387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The positron emission tomography (PET) radiotracer [11C]PBR28 has been increasingly used to image the translocator protein (TSPO) as a marker of neuroinflammation in a variety of brain disorders. Interrelatedly, similar clinical populations can also exhibit altered brain perfusion, as has been shown using arterial spin labelling in magnetic resonance imaging (MRI) studies. Hence, an unsolved debate has revolved around whether changes in perfusion could alter delivery, uptake, or washout of the radiotracer [11C]PBR28, and thereby influence outcome measures that affect interpretation of TSPO upregulation. In this simultaneous PET/MRI study, we demonstrate that [11C]PBR28 signal elevations in chronic low back pain patients are not accompanied, in the same regions, by increases in cerebral blood flow (CBF) compared to healthy controls, and that areas of marginal hypoperfusion are not accompanied by decreases in [11C]PBR28 signal. In non-human primates, we show that hypercapnia-induced increases in CBF during radiotracer delivery or washout do not alter [11C]PBR28 outcome measures. The combined results from two methodologically distinct experiments provide support from human data and direct experimental evidence from non-human primates that changes in CBF do not influence outcome measures reported by [11C]PBR28 PET imaging studies and corresponding interpretations of the biological meaning of TSPO upregulation.
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Affiliation(s)
- Christin Y Sander
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Stefano Bovo
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Information Engineering, University of Padova, Padova, Italy
| | - Angel Torrado-Carvajal
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain
| | - Daniel Albrecht
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA
| | - Hongping Deng
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA
| | - Vitaly Napadow
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Julie C Price
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Jacob M Hooker
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Marco L Loggia
- Department of Radiology, Athinoula A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Boston, MA, USA
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13
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Tournier BB, Tsartsalis S, Ceyzériat K, Fraser BH, Grégoire MC, Kövari E, Millet P. Astrocytic TSPO Upregulation Appears Before Microglial TSPO in Alzheimer's Disease. J Alzheimers Dis 2021; 77:1043-1056. [PMID: 32804124 PMCID: PMC7683091 DOI: 10.3233/jad-200136] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background: In vivo PET/SPECT imaging of neuroinflammation is primarily based on the estimation of the 18 kDa-translocator-protein (TSPO). However, TSPO is expressed by different cell types which complicates the interpretation. Objective: The present study evaluates the cellular origin of TSPO alterations in Alzheimer’s disease (AD). Methods: The TSPO cell origin was evaluated by combining radioactive imaging approaches using the TSPO radiotracer [125I]CLINDE and fluorescence-activated cell sorting, in a rat model of AD (TgF344-AD) and in AD subjects. Results: In the hippocampus of TgF344-AD rats, TSPO overexpression not only concerns glial cells but the increase is visible at 12 and 24 months in astrocytes and only at 24 months in microglia. In the temporal cortex of AD subjects, TSPO upregulation involved only glial cells. However, the mechanism of this upregulation appears different with an increase in the number of TSPO binding sites per cell without cell proliferation in the rat, and a microglial cell population expansion with a constant number of binding sites per cell in human AD. Conclusion: These data indicate an earlier astrocyte intervention than microglia and that TSPO in AD probably is an exclusive marker of glial activity without interference from other TSPO-expressing cells. This observation indicates that the interpretation of TSPO imaging depends on the stage of the pathology, and highlights the particular role of astrocytes.
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Affiliation(s)
- Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland
| | - Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland
| | - Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland.,Division of Nuclear medicine, University Hospitals of Geneva, Switzerland
| | - Ben H Fraser
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Sydney, NSW, Australia
| | - Marie-Claude Grégoire
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Sydney, NSW, Australia
| | - Enikö Kövari
- Division of Geriatric Psychiatry, Department of Mental Health and Psychiatry, University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Switzerland
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14
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Gritti D, Delvecchio G, Ferro A, Bressi C, Brambilla P. Neuroinflammation in Major Depressive Disorder: A Review of PET Imaging Studies Examining the 18-kDa Translocator Protein. J Affect Disord 2021; 292:642-651. [PMID: 34153835 DOI: 10.1016/j.jad.2021.06.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Major Depressive Disorder (MDD) is a severe psychiatric disorder whose pathological mechanisms are largely unknown. In the field of immuno-psychiatry, several evidences suggested a prominent role of inflammation in MDD not only in peripheral immune system but also in the brain. To date, brain inflammation is traceable in vivo with Positron Emission Tomography (PET), through the quantification of the expression of 18-kda Translocator Protein (TSPO) by active microglia. In this context, this review aimed to summarize the results of all in vivo PET imaging studies that evaluated microglia activation in MDD. METHODS A bibliographic search in PubMed up to June 2020 was performed. A total of 9 studies that used first and second generation TSPO radiotracers met our inclusion criteria. RESULTS Overall the results suggested the presence of TSPO upregulation in MDD, especially in anterior cingulate cortex, prefrontal cortex, hippocampal formation and insula. Notably, from a therapeutic point of view, results suggested that the symptoms amelioration, caused by both antidepressant medication and cognitive behavioural therapy, may be accompanied by reduced inflammatory status in the brain. Finally, a positive effect of the anti-inflammatory treatment with a cyclooxygenase inhibitor has also been observed. LIMITATIONS The heterogeneity across the studies in experimental designs, sample selection and methods limited the studies comparison. CONCLUSIONS These findings supported the presence of neuroinflammation in MDD, suggesting that microgliosis may be an important pathophysiological mechanism that merits further investigation as a potential target for novel treatment strategies.
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Affiliation(s)
- Davide Gritti
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Delvecchio
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
| | - Adele Ferro
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Cinzia Bressi
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Paolo Brambilla
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy; Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
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15
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Ji B, Ono M, Yamasaki T, Fujinaga M, Zhang MR, Seki C, Aoki I, Kito S, Sawada M, Suhara T, Sahara N, Higuchi M. Detection of Alzheimer's disease-related neuroinflammation by a PET ligand selective for glial versus vascular translocator protein. J Cereb Blood Flow Metab 2021; 41:2076-2089. [PMID: 33557690 PMCID: PMC8327108 DOI: 10.1177/0271678x21992457] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A substantial and constitutive expression of translocator protein (TSPO) in cerebral blood vessels hampers the sensitive detection of neuroinflammation characterized by greatly induced TSPO expression in activated glia. Here, we conducted in vivo positron emission tomography (PET) and in vitro autoradiographic imaging of normal and TSPO-deficient mouse brains to compare the binding properties of 18F-FEBMP, a relatively novel TSPO radioligand developed for human studies based on its insensitivity to a common polymorphism, with 11C-PK11195, as well as other commonly used TSPO radioligands including 11C-PBR28, 11C-Ac5216 and 18F-FEDAA1106. TSPO in cerebral vessels of normal mice was found to provide a major binding site for 11C-PK11195, 11C-PBR28 and 18F-FEDAA1106, in contrast to no overt specific binding of 18F-FEBMP and 11C-Ac5216 to this vascular component. In addition, 18F-FEBMP yielded PET images of microglial TSPO with a higher contrast than 11C-PK11195 in a tau transgenic mouse modeling Alzheimer's disease (AD) and allied neurodegenerative tauopathies. Moreover, TSPO expression examined by immunoblotting was significantly increased in AD brains compared with healthy controls, and was well correlated with the autoradiographic binding of 18F-FEBMP but not 11C-PK11195. Our findings support the potential advantage of comparatively glial TSPO-selective radioligands such as 18F-FEBMP for PET imaging of inflammatory glial cells.
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Affiliation(s)
- Bin Ji
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Maiko Ono
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tomoteru Yamasaki
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masayuki Fujinaga
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ming-Rong Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Chie Seki
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ichio Aoki
- Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Seiji Kito
- Research, Development and Support Center, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Makoto Sawada
- Department of Brain Function, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi, Japan
| | - Tetsuya Suhara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Naruhiko Sahara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
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16
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Veronese M, Tuosto M, Marques TR, Howes O, Pascual B, Yu M, Masdeu JC, Turkheimer F, Bertoldo A, Zanotti-Fregonara P. Parametric Mapping for TSPO PET Imaging with Spectral Analysis Impulsive Response Function. Mol Imaging Biol 2021; 23:560-571. [PMID: 33475944 PMCID: PMC8277653 DOI: 10.1007/s11307-020-01575-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/27/2020] [Accepted: 12/21/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to investigate the use of spectral analysis (SA) for voxel-wise analysis of TSPO PET imaging studies. TSPO PET quantification is methodologically complicated by the heterogeneity of TSPO expression and its cell-dependent modulation during neuroinflammatory response. Compartmental models to account for this complexity exist, but they are unreliable at the high noise typical of voxel data. On the contrary, SA is noise-robust for parametric mapping and provides useful information about tracer kinetics with a free compartmental structure. PROCEDURES SA impulse response function (IRF) calculated at 90 min after tracer injection was used as main parameter of interest in 3 independent PET imaging studies to investigate its sensitivity to (1) a TSPO genetic polymorphism (rs6971) known to affect tracer binding in a cross-sectional analysis of healthy controls scanned with [11C]PBR28 PET; (2) TSPO density with [11C]PBR28 in a competitive blocking study with a TSPO blocker, XBD173; and (3) the higher affinity of a second radiotracer for TSPO, by using data from a head-to-head comparison between [11C]PBR28 and [11C]ER176 scans. RESULTS SA-IRF produced parametric maps of visually good quality. These were sensitive to TSPO genotype (mean relative difference between high- and mixed-affinity binders = 25 %) and TSPO availability (mean signal displacement after 90 mg oral administration of XBD173 = 39 %). Regional averages of voxel-wise IRF estimates were strongly associated with regional total distribution volume (VT) estimated with a 2-tissue compartmental model with vascular compartment (Pearson's r = 0.86 ± 0.11) but less strongly with standard 2TCM-VT (Pearson's r = 0.76 ± 0.32). Finally, SA-IRF estimates for [11C]ER176 were significantly higher than [11C]PBR28 ones, consistent with the higher amount of specific binding of the former tracer. CONCLUSIONS SA-IRF can be used for voxel-wise quantification of TSPO PET data because it generates high-quality parametric maps, it is sensitive to TSPO availability and genotype, and it accounts for the complexity of TSPO tracer kinetics with no additional assumptions.
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Affiliation(s)
- Mattia Veronese
- Department of Neuroimaging, IoPPN, King's College London, London, UK.
| | - Marcello Tuosto
- Department of Information Engineering, Padova University, Padova, Italy
| | - Tiago Reis Marques
- Department of Psychosis Studies, IoPPN, King's College London, London, UK
| | - Oliver Howes
- Department of Psychosis Studies, IoPPN, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - Belen Pascual
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | - Meixiang Yu
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | - Joseph C Masdeu
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | | | - Alessandra Bertoldo
- Department of Information Engineering, Padova University, Padova, Italy
- Padova Neuroscience Centre, Padova University, Padova, Italy
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
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17
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Giordani A, Menziani MC, Moresco RM, Matarrese M, Paolino M, Saletti M, Giuliani G, Anzini M, Cappelli A. Exploring Translocator Protein (TSPO) Medicinal Chemistry: An Approach for Targeting Radionuclides and Boron Atoms to Mitochondria. J Med Chem 2021; 64:9649-9676. [PMID: 34254805 DOI: 10.1021/acs.jmedchem.1c00379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Translocator protein 18 kDa [TSPO or peripheral-type benzodiazepine receptor (PBR)] was identified in the search of binding sites for benzodiazepine anxiolytic drugs in peripheral regions. In these areas, binding sites for TSPO ligands were recognized in steroid-producing tissues. TSPO plays an important role in many cellular functions, and its coding sequence is highly conserved across species. TSPO is located predominantly on the membrane of mitochondria and is overexpressed in several solid cancers. TSPO basal expression in the CNS is low, but it becomes high in neurodegenerative conditions. Thus, TSPO constitutes not only as an outstanding drug target but also as a valuable marker for the diagnosis of a number of diseases. The aim of the present article is to show the lesson we have learned from our activity in TSPO medicinal chemistry and in approaching the targeted delivery to mitochondria by means of TSPO ligands.
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Affiliation(s)
- Antonio Giordani
- Rottapharm Biotech S.p.A., Via Valosa di Sopra 9, 20900 Monza, Italy
| | - Maria Cristina Menziani
- Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, Via Campi 103, 41121 Modena, Italy
| | - Rosa Maria Moresco
- Department of Medicine and Surgery, University of Milan-Bicocca, Nuclear Medicine Department, San Raffaele Scientific Institute, IBFM-CNR, Via Olgettina 60, 20132 Milano, Italy
| | - Mario Matarrese
- Department of Medicine and Surgery, University of Milan-Bicocca, Nuclear Medicine Department, San Raffaele Scientific Institute, IBFM-CNR, Via Olgettina 60, 20132 Milano, Italy
| | - Marco Paolino
- Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022), Università di Siena, Via A. Moro 2, 53100 Siena, Italy
| | - Mario Saletti
- Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022), Università di Siena, Via A. Moro 2, 53100 Siena, Italy
| | - Germano Giuliani
- Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022), Università di Siena, Via A. Moro 2, 53100 Siena, Italy
| | - Maurizio Anzini
- Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022), Università di Siena, Via A. Moro 2, 53100 Siena, Italy
| | - Andrea Cappelli
- Dipartimento di Biotecnologie, Chimica e Farmacia (Dipartimento di Eccellenza 2018-2022), Università di Siena, Via A. Moro 2, 53100 Siena, Italy
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18
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Peters van Ton AM, Leijte GP, Franssen GM, Bruse N, Booij J, Doorduin J, Rijpkema M, Kox M, Abdo WF, Pickkers P. Human in vivo neuroimaging to detect reprogramming of the cerebral immune response following repeated systemic inflammation. Brain Behav Immun 2021; 95:321-329. [PMID: 33839233 DOI: 10.1016/j.bbi.2021.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/17/2021] [Accepted: 04/07/2021] [Indexed: 01/15/2023] Open
Abstract
Despite increasing evidence that immune training within the brain may affect the clinical course of neuropsychiatric diseases, data on cerebral immune tolerance are scarce. This study in healthy volunteers examined the trajectory of the immune response systemically and within the brain following repeated lipopolysaccharide (LPS) challenges. Five young males underwent experimental human endotoxemia (intravenous administration of 2 ng/kg LPS) twice with a 7-day interval. The systemic immune response was assessed by measuring plasma cytokine levels. Four positron emission tomography (PET) examinations, using the translocator protein (TSPO) ligand 18F-DPA-714, were performed in each participant, to assess brain immune cell activation prior to and 5 hours after both LPS challenges. The first LPS challenge caused a profound systemic inflammatory response and resulted in a 53% [95%CI 36-71%] increase in global cerebral 18F-DPA-714 binding (p < 0.0001). Six days after the first challenge, 18F-DPA-714 binding had returned to baseline levels (p = 0.399). While the second LPS challenge resulted in a less pronounced systemic inflammatory response (i.e. 77 ± 14% decrease in IL-6 compared to the first challenge), cerebral inflammation was not attenuated, but decreased below baseline, illustrated by a diffuse reduction of cerebral 18F-DPA-714 binding (-38% [95%CI -47 to -28%], p < 0.0001). Our findings constitute evidence for in vivo immunological reprogramming in the brain following a second inflammatory insult in healthy volunteers, which could represent a neuroprotective mechanism. These results pave the way for further studies on immunotolerance in the brain in patients with systemic inflammation-induced cerebral dysfunction.
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Affiliation(s)
- Annemieke M Peters van Ton
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands
| | - Guus P Leijte
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands
| | - Gerben M Franssen
- Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Medical Imaging, Nijmegen, the Netherlands
| | - Niklas Bruse
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands
| | - Jan Booij
- Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Medical Imaging, Nijmegen, the Netherlands; Amsterdam University Medical Centers, Location Academic Medical Center, University of Amsterdam, Department of Radiology & Nuclear Medicine, Amsterdam, the Netherlands
| | - Janine Doorduin
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands
| | - Mark Rijpkema
- Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Medical Imaging, Nijmegen, the Netherlands
| | - Matthijs Kox
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands
| | - Wilson F Abdo
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands.
| | - Peter Pickkers
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Intensive Care Medicine, Nijmegen, the Netherlands; Radboud University Medical Center, Radboud Center for Infectious Diseases, Nijmegen, the Netherlands
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19
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Zürcher NR, Loggia ML, Mullett JE, Tseng C, Bhanot A, Richey L, Hightower BG, Wu C, Parmar AJ, Butterfield RI, Dubois JM, Chonde DB, Izquierdo-Garcia D, Wey HY, Catana C, Hadjikhani N, McDougle CJ, Hooker JM. [ 11C]PBR28 MR-PET imaging reveals lower regional brain expression of translocator protein (TSPO) in young adult males with autism spectrum disorder. Mol Psychiatry 2021; 26:1659-1669. [PMID: 32076115 PMCID: PMC8159742 DOI: 10.1038/s41380-020-0682-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 01/12/2020] [Accepted: 02/06/2020] [Indexed: 12/19/2022]
Abstract
Mechanisms of neuroimmune and mitochondrial dysfunction have been repeatedly implicated in autism spectrum disorder (ASD). To examine these mechanisms in ASD individuals, we measured the in vivo expression of the 18 kDa translocator protein (TSPO), an activated glial marker expressed on mitochondrial membranes. Participants underwent scanning on a simultaneous magnetic resonance-positron emission tomography (MR-PET) scanner with the second-generation TSPO radiotracer [11C]PBR28. By comparing TSPO in 15 young adult males with ASD with 18 age- and sex-matched controls, we showed that individuals with ASD exhibited lower regional TSPO expression in several brain regions, including the bilateral insular cortex, bilateral precuneus/posterior cingulate cortex, and bilateral temporal, angular, and supramarginal gyri, which have previously been implicated in autism in functional MR imaging studies. No brain region exhibited higher regional TSPO expression in the ASD group compared with the control group. A subset of participants underwent a second MR-PET scan after a median interscan interval of 3.6 months, and we determined that TSPO expression over this period of time was stable and replicable. Furthermore, voxelwise analysis confirmed lower regional TSPO expression in ASD at this later time point. Lower TSPO expression in ASD could reflect abnormalities in neuroimmune processes or mitochondrial dysfunction.
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Affiliation(s)
- N R Zürcher
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
- Harvard Medical School, Boston, MA, USA.
| | - M L Loggia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - J E Mullett
- Lurie Center for Autism, Massachusetts General Hospital, Lexington, MA, USA
| | - C Tseng
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - A Bhanot
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - L Richey
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - B G Hightower
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - C Wu
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - A J Parmar
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - R I Butterfield
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - J M Dubois
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - D B Chonde
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - D Izquierdo-Garcia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - H Y Wey
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - C Catana
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - N Hadjikhani
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Harvard Medical School, Boston, MA, USA
- Gillberg Neuropsychiatry Center, University of Gothenburg, Sahlgrenska Academy, Gothenburg, Sweden
| | - C J McDougle
- Harvard Medical School, Boston, MA, USA
- Lurie Center for Autism, Massachusetts General Hospital, Lexington, MA, USA
| | - J M Hooker
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
- Harvard Medical School, Boston, MA, USA.
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20
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Selvaggi P, Rizzo G, Mehta MA, Turkheimer FE, Veronese M. Integration of human whole-brain transcriptome and neuroimaging data: Practical considerations of current available methods. J Neurosci Methods 2021; 355:109128. [PMID: 33722642 DOI: 10.1016/j.jneumeth.2021.109128] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/12/2021] [Accepted: 03/01/2021] [Indexed: 12/20/2022]
Abstract
The Allen Human Brain Atlas (AHBA) is the first example of human brain transcriptomic mappings and detailed anatomical annotations which, for the first time, has allowed the integration of human brain transcriptomics with neuroimaging. This has been made possible because the AHBA offered an original dataset that contains mRNA expression measures for >20,000 genes covering the whole brain and, critically, in a standard stereotaxic space. In recent years many different methods have been used to integrate this data set with brain imaging data, although this endeavour has lacked harmony in terms of the workflow of data processing and subsequent analyses. In this work we discuss five main issues that experience has highlighted as in need of thorough consideration when integrating the AHBA with neuroimaging. These concerns are corroborated by comparing the performance of three different publicly available methods in correlating the same measures of serotonin receptors density with the correspondent AHBA mRNA maps. In this representative case, we were able to show how these methods can lead to discrepant results, suggesting that processing options are not neutral. We believe that the field should take into serious consideration these issues as they could undermine reproducibility and, in the end, the intrinsic value of the AHBA. We also advise on possible strategies to overcome these discrepancies. Finally, we encourage authors towards practices that will improve reproducibility such as transparency in reporting, algorithm and data sharing, collaboration.
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Affiliation(s)
- Pierluigi Selvaggi
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Gaia Rizzo
- Invicro, W12 0NN, London, UK; Division of Brain Sciences, Department of Medicine, Imperial College London, SW72AZ, London, UK
| | - Mitul A Mehta
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Federico E Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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21
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Adhikari A, Singh P, Mahar KS, Adhikari M, Adhikari B, Zhang MR, Tiwari AK. Mapping of Translocator Protein (18 kDa) in Peripheral Sterile Inflammatory Disease and Cancer through PET Imaging. Mol Pharm 2021; 18:1507-1529. [PMID: 33645995 DOI: 10.1021/acs.molpharmaceut.1c00002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Positron emission tomography (PET) imaging of the translocator 18 kDa protein (TSPO) with radioligands has become an effective means of research in peripheral inflammatory conditions that occur in many diseases and cancers. The peripheral sterile inflammatory diseases (PSIDs) are associated with a diverse group of disorders that comprises numerous enduring insults including the cardiovascular, respiratory, gastrointestinal, or musculoskeletal system. TSPO has recently been introduced as a potential biomarker for peripheral sterile inflammatory diseases (PSIDs). The major critical issue related to PSIDs is its timely characterization and localization of inflammatory foci for proper therapy of patients. As an alternative to metabolic imaging, protein imaging expressed on immune cells after activation is of great importance. The five transmembrane domain translocator protein-18 kDa (TSPO) is upregulated on the mitochondrial cell surface of macrophages during inflammation, serving as a potential ligand for PET tracers. Additionally, the overexpressed TSPO protein has been positively correlated with various tumor malignancies. In view of the association of escalated TSPO expression in both disease conditions, it is an immensely important biomarker for PET imaging in oncology and PSIDs. In this review, we summarize the most outstanding advances on TSPO-targeted PSIDs and cancer in the development of TSPO ligands as a potential diagnostic tool, specifically discussing the last five years.
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Affiliation(s)
- Anupriya Adhikari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, (A Central University), Lucknow, Uttar Pradesh 226025, India
| | - Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, A Central University, Lucknow, Uttar Pradesh 226025, India
| | - Kamalesh S Mahar
- Birbal Sahni Institute of Palaeosciences, Lucknow, Uttar Pradesh 226007, India
| | - Manish Adhikari
- The George Washington University, Washington, D.C. 20052, United States
| | - Bhawana Adhikari
- Plasma Bio-science Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Anjani Kumar Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, (A Central University), Lucknow, Uttar Pradesh 226025, India
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22
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Pinpointing Brain TREM2 Levels in Two Mouse Models of Alzheimer's Disease. Mol Imaging Biol 2021; 23:665-675. [PMID: 33620643 PMCID: PMC8410720 DOI: 10.1007/s11307-021-01591-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 01/11/2021] [Accepted: 02/11/2021] [Indexed: 11/01/2022]
Abstract
PURPOSE The triggering receptor expressed on myeloid cells 2 (TREM2) is expressed by brain microglia. Microglial activation, as observed in Alzheimer's disease (AD) as well as in transgenic mice expressing human amyloid-beta, appears to increase soluble TREM2 (sTREM2) levels in CSF and brain. In this study, we used two different transgenic mouse models of AD pathology and investigated the potential of TREM2 to serve as an in vivo biomarker for microglial activation in AD. PROCEDURES We designed and generated a bispecific antibody based on the TREM2-specific monoclonal antibody mAb1729, fused to a single-chain variable fragment of the transferrin receptor binding antibody 8D3. The 8D3-moiety enabled transcytosis of the whole bispecific antibody across the blood-brain barrier. The bispecific antibody was radiolabeled with I-125 (ex vivo) or I-124 (PET) and administered to transgenic AD and wild-type (WT) control mice. Radioligand retention in the brain of transgenic animals was compared to WT mice by isolation of brain tissue at 24 h or 72 h, or with in vivo PET at 24 h, 48 h, and 72 h. Intrabrain distribution of radiolabeled mAb1729-scFv8D3CL was further studied by autoradiography, while ELISA was used to determine TREM2 brain concentrations. RESULTS Transgenic animals displayed higher total exposure, calculated as the AUC based on SUV determined at 24h, 48h, and 72h post injection, of PET radioligand [124I]mAb1729-scFv8D3CL than WT mice. However, differences were not evident in single time point PET images or SUVs. Ex vivo autoradiography confirmed higher radioligand concentrations in cortex and thalamus in transgenic mice compared to WT, and TREM2 levels in brain homogenates were considerably higher in transgenic mice compared to WT. CONCLUSION Antibody-based radioligands, engineered to enter the brain, may serve as PET radioligands to follow changes of TREM2 in vivo, but antibody formats with faster systemic clearance to increase the specific signal in relation to that from blood in combination with antibodies showing higher affinity for TREM2 must be developed to further progress this technique for in vivo use.
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23
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Turkheimer FE, Althubaity N, Schubert J, Nettis MA, Cousins O, Dima D, Mondelli V, Bullmore ET, Pariante C, Veronese M. Increased serum peripheral C-reactive protein is associated with reduced brain barriers permeability of TSPO radioligands in healthy volunteers and depressed patients: implications for inflammation and depression. Brain Behav Immun 2021; 91:487-497. [PMID: 33160089 DOI: 10.1016/j.bbi.2020.10.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 01/08/2023] Open
Abstract
The relationship between peripheral and central immunity and how these ultimately may cause depressed behaviour has been the focus of a number of imaging studies conducted with Positron Emission Tomography (PET). These studies aimed at testing the immune-mediated model of depression that proposes a direct effect of peripheral cytokines and immune cells on the brain to elicit a neuroinflammatory response via a leaky blood-brain barrier and ultimately depressive behaviour. However, studies conducted so far using PET radioligands targeting the neuroinflammatory marker 18 kDa translocator protein (TSPO) in patient cohorts with depression have demonstrated mild inflammatory brain status but no correlation between central and peripheral immunity. To gain a better insight into the relationship between heightened peripheral immunity and neuroinflammation, we estimated blood-to-brain and blood-to-CSF perfusion rates for two TSPO radiotracers collected in two separate studies, one large cross-sectional study of neuroinflammation in normal and depressed cohorts (N = 51 patients and N = 25 controls) and a second study where peripheral inflammation in N = 7 healthy controls was induced via subcutaneous injection of interferon (IFN)-α. In both studies we observed a consistent negative association between peripheral inflammation, measured with c-reactive protein P (CRP), and radiotracer perfusion into and from the brain parenchyma and CSF. Importantly, there was no association of this effect with the marker of BBB leakage S100β, that was unchanged. These results suggest a different model of peripheral-to-central immunity interaction whereas peripheral inflammation may cause a reduction in BBB permeability. This effect, on the long term, is likely to disrupt brain homeostasis and induce depressive behavioural symptoms.
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Affiliation(s)
- Federico E Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Noha Althubaity
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Julia Schubert
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Maria A Nettis
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Oliver Cousins
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Danai Dima
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Department of Psychology, School of Arts and Social Sciences, City, University of London, London, UK
| | - Valeria Mondelli
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Edward T Bullmore
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, UK; Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK
| | - Carmine Pariante
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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24
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Wright P, Veronese M, Mazibuko N, Turkheimer FE, Rabiner EA, Ballard CG, Williams SCR, Hari Narayanan AK, Osrah B, Williams R, Marques TR, Howes OD, Roncaroli F, O'Sullivan MJ. Patterns of Mitochondrial TSPO Binding in Cerebral Small Vessel Disease: An in vivo PET Study With Neuropathological Comparison. Front Neurol 2020; 11:541377. [PMID: 33178101 PMCID: PMC7596201 DOI: 10.3389/fneur.2020.541377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/20/2020] [Indexed: 12/11/2022] Open
Abstract
Small vessel disease (SVD) is associated with cognitive impairment in older age and be implicated in vascular dementia. Post-mortem studies show proliferation of activated microglia in the affected white matter. However, the role of inflammation in SVD pathogenesis is incompletely understood and better biomarkers are needed. We hypothesized that expression of the 18 kDa translocator protein (TSPO), a marker of microglial activation, would be higher in SVD. Positron emission tomography (PET) was performed with the second-generation TSPO ligand [11C]PBR28 in 11 participants with SVD. TSPO binding was evaluated by a two-tissue compartment model, with and without a vascular binding component, in white matter hyperintensities (WMH) and normal-appearing white matter (NAWM). In post-mortem tissue, in a separate cohort of individuals with SVD, immunohistochemistry was performed for TSPO and a pan-microglial marker Iba1. Kinetic modeling showed reduced tracer volume and blood volume fraction in WMH compared with NAWM, but a significant increase in vascular binding. Vascular [11C]PBR28 binding was also increased compared with normal-appearing white matter of healthy participants free of SVD. Immunohistochemistry showed a diffuse increase in microglial staining (with Iba1) in sampled tissue in SVD compared with control samples, but with only a subset of microglia staining positively for TSPO. Intense TSPO staining was observed in the vicinity of damaged small blood vessels, which included perivascular macrophages. The results suggest an altered phenotype of activated microglia, with reduced TSPO expression, in the areas of greatest white matter ischemia in SVD, with implications for the interpretation of TSPO PET studies in older individuals or those with vascular risk factors.
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Affiliation(s)
- Paul Wright
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Ndabezinhle Mazibuko
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Federico E. Turkheimer
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Eugenii A. Rabiner
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- Invicro, London, United Kingdom
| | - Clive G. Ballard
- College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Steven C. R. Williams
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Avinash Kumar Hari Narayanan
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Bahiya Osrah
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Ricky Williams
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Tiago R. Marques
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Federico Roncaroli
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Michael J. O'Sullivan
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- University of Queensland Centre for Clinical Research, Brisbane, QLD, Australia
- Department of Neurology, The Royal Brisbane and Women's Hospital, Herston, QLD, Australia
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25
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In Vivo TSPO Signal and Neuroinflammation in Alzheimer's Disease. Cells 2020; 9:cells9091941. [PMID: 32839410 PMCID: PMC7565089 DOI: 10.3390/cells9091941] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 12/15/2022] Open
Abstract
In the last decade, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) in in vivo imaging has attempted to demonstrate the presence of neuroinflammatory reactions by measuring the 18 kDa translocator protein (TSPO) expression in many diseases of the central nervous system. We focus on two pathological conditions for which neuropathological studies have shown the presence of neuroinflammation, which translates in opposite in vivo expression of TSPO. Alzheimer's disease has been the most widely assessed with more than forty preclinical and clinical studies, showing overall that TSPO is upregulated in this condition, despite differences in the topography of this increase, its time-course and the associated cell types. In the case of schizophrenia, a reduction of TSPO has instead been observed, though the evidence remains scarce and contradictory. This review focuses on the key characteristics of TSPO as a biomarker of neuroinflammation in vivo, namely, on the cellular origin of the variations in its expression, on its possible biological/pathological role and on its variations across disease phases.
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26
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Laurell GL, Plavén-Sigray P, Jucaite A, Varrone A, Cosgrove KP, Svarer C, Knudsen GM, Ogden RT, Zanderigo F, Cervenka S, Hillmer AT, Schain M. Nondisplaceable Binding Is a Potential Confounding Factor in 11C-PBR28 Translocator Protein PET Studies. J Nucl Med 2020; 62:412-417. [PMID: 32680926 DOI: 10.2967/jnumed.120.243717] [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: 02/17/2020] [Accepted: 06/23/2020] [Indexed: 01/08/2023] Open
Abstract
The PET ligand 11C-PBR28 (N-((2-(methoxy-11C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) binds to the 18-kDa translocator protein (TSPO), a biomarker of glia. In clinical studies of TSPO, the ligand total distribution volume, VT, is frequently the reported outcome measure. Since VT is the sum of the ligand-specific distribution volume (VS) and the nondisplaceable-binding distribution volume (VND), differences in VND across subjects and groups will have an impact on VT Methods: Here, we used a recently developed method for simultaneous estimation of VND (SIME) to disentangle contributions from VND and VS Data from 4 previously published 11C-PBR28 PET studies were included: before and after a lipopolysaccharide challenge (8 subjects), in alcohol use disorder (14 patients, 15 controls), in first-episode psychosis (16 patients, 16 controls), and in Parkinson disease (16 patients, 16 controls). In each dataset, regional VT estimates were obtained with a standard 2-tissue-compartment model, and brain-wide VND was estimated with SIME. VS was then calculated as VT - VND VND and VS were then compared across groups, within each dataset. Results: A lower VND was found for individuals with alcohol-use disorder (34%, P = 0.00084) and Parkinson disease (34%, P = 0.0032) than in their corresponding controls. We found no difference in VND between first-episode psychosis patients and their controls, and the administration of lipopolysaccharide did not change VND Conclusion: Our findings suggest that in TSPO PET studies, nondisplaceable binding can differ between patient groups and conditions and should therefore be considered.
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Affiliation(s)
- Gjertrud L Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Aurelija Jucaite
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.,PET Science Centre, Precision Medicine and Genomics, R&D, AstraZeneca, Stockholm, Sweden
| | - Andrea Varrone
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Kelly P Cosgrove
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - R Todd Ogden
- Department of Biostatistics, Columbia University, New York, New York.,Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, New York
| | - Francesca Zanderigo
- Department of Biostatistics, Columbia University, New York, New York.,Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Ansel T Hillmer
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut.,Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
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27
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Tjerkaski J, Cervenka S, Farde L, Matheson GJ. Kinfitr - an open-source tool for reproducible PET modelling: validation and evaluation of test-retest reliability. EJNMMI Res 2020; 10:77. [PMID: 32642865 PMCID: PMC7343683 DOI: 10.1186/s13550-020-00664-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/25/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND In positron emission tomography (PET) imaging, binding is typically estimated by fitting pharmacokinetic models to the series of measurements of radioactivity in the target tissue following intravenous injection of a radioligand. However, there are multiple different models to choose from and numerous analytical decisions that must be made when modelling PET data. Therefore, it is important that analysis tools be adapted to the specific circumstances, and that analyses be documented in a transparent manner. Kinfitr, written in the open-source programming language R, is a tool developed for flexible and reproducible kinetic modelling of PET data, i.e. performing all steps using code which can be publicly shared in analysis notebooks. In this study, we compared outcomes obtained using kinfitr with those obtained using PMOD: a widely used commercial tool. RESULTS Using previously collected test-retest data obtained with four different radioligands, a total of six different kinetic models were fitted to time-activity curves derived from different brain regions. We observed good correspondence between the two kinetic modelling tools both for binding estimates and for microparameters. Likewise, no substantial differences were observed in the test-retest reliability estimates between the two tools. CONCLUSIONS In summary, we showed excellent agreement between the open-source R package kinfitr, and the widely used commercial application PMOD. We, therefore, conclude that kinfitr is a valid and reliable tool for kinetic modelling of PET data.
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Affiliation(s)
- Jonathan Tjerkaski
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76, Stockholm, Sweden.
| | - Simon Cervenka
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76, Stockholm, Sweden
| | - Granville James Matheson
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76, Stockholm, Sweden
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Pigeon H, Pérès EA, Truillet C, Jego B, Boumezbeur F, Caillé F, Zinnhardt B, Jacobs AH, Le Bihan D, Winkeler A. TSPO-PET and diffusion-weighted MRI for imaging a mouse model of infiltrative human glioma. Neuro Oncol 2020; 21:755-764. [PMID: 30721979 DOI: 10.1093/neuonc/noz029] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Glioblastoma (GBM) is the most devastating brain tumor. Despite the use of multimodal treatments, most patients relapse, often due to the highly invasive nature of gliomas. However, the detection of glioma infiltration remains challenging. The aim of this study was to assess advanced PET and MRI techniques for visualizing biological activity and infiltration of the tumor. METHODS Using multimodality imaging, we investigated [18F]DPA-714, a radiotracer targeting the 18 kDa translocator protein (TSPO), [18F]FET PET, non-Gaussian diffusion MRI (apparent diffusion coefficient, kurtosis), and the S-index, a composite diffusion metric, to detect tumor infiltration in a human invasive glioma model. In vivo imaging findings were confirmed by autoradiography and immunofluorescence. RESULTS Increased tumor-to-contralateral [18F]DPA-714 uptake ratios (1.49 ± 0.11) were found starting 7 weeks after glioma cell implantation. TSPO-PET allowed visualization of glioma infiltration into the contralateral hemisphere 2 weeks earlier compared with the clinically relevant biomarker for biological glioma activity [18F]FET. Diffusion-weighted imaging (DWI), in particular kurtosis, was more sensitive than standard T2-weighted MRI to detect differences between the glioma-bearing and the contralateral hemisphere at 5 weeks. Immunofluorescence data reflect in vivo findings. Interestingly, labeling for tumoral and stromal TSPO indicates a predominant expression of TSPO by tumor cells. CONCLUSION These results suggest that advanced PET and MRI methods, such as [18F]DPA-714 and DWI, may be superior to standard imaging methods to visualize glioma growth and infiltration at an early stage.
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Affiliation(s)
- Hayet Pigeon
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Elodie A Pérès
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France.,NeuroSpin, CEA/Université Paris-Saclay, Gif sur Yvette, France.,Normandie Université, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen, France
| | - Charles Truillet
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Benoit Jego
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | | | - Fabien Caillé
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Bastian Zinnhardt
- EIMI and Department of Nuclear Medicine, University Hospital Münster, Westfälische Wilhelms University Münster, Münster, Germany
| | - Andreas H Jacobs
- EIMI and Department of Nuclear Medicine, University Hospital Münster, Westfälische Wilhelms University Münster, Münster, Germany.,Department of Geriatrics, Johanniter Hospital, Evangelische Kliniken, Bonn, Germany
| | - Denis Le Bihan
- NeuroSpin, CEA/Université Paris-Saclay, Gif sur Yvette, France
| | - Alexandra Winkeler
- UMR 1023, IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm, Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
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29
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Tournier BB, Tsartsalis S, Ceyzériat K, Medina Z, Fraser BH, Grégoire MC, Kövari E, Millet P. Fluorescence-activated cell sorting to reveal the cell origin of radioligand binding. J Cereb Blood Flow Metab 2020; 40:1242-1255. [PMID: 31242048 PMCID: PMC7238369 DOI: 10.1177/0271678x19860408] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many studies have explored the role of TSPO (18 kDa translocator protein) as a marker of neuroinflammation using single-photon emission computed tomography (SPECT) or positron emission tomography (PET). In vivo imaging does not allow to determine the cells in which TSPO is altered. We propose a methodology based on fluorescence-activated cell sorting to sort different cell types of radioligand-treated tissues. We compared left/right hippocampus of rats in response to a unilateral injection of lipopolysaccharide (LPS), ciliary neurotrophic factor (CNTF) or saline. We finally applied this methodology in human samples (Alzheimer's disease patients and controls). Our data show that the pattern of TSPO overexpression differs across animal models of acute neuroinflammation. LPS induces a microglial expansion and an increase in microglial TSPO binding. CNTF is associated with an increase in TSPO binding in microglia and astrocytes in association with an increase in the number of microglial binding sites per cell. In humans, we show that the increase in CLINDE binding in Alzheimer's disease concerns microglia and astrocytes in the presence of a microglial expansion. Thus, the cellular basis of TSPO overexpression is condition dependent, and alterations in TSPO binding found in PET/SPECT imaging studies cannot be attributed to particular cell types indiscriminately.
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Affiliation(s)
- Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland.,Division of Nuclear medicine, University Hospitals of Geneva, Geneva, Switzerland
| | - Zadith Medina
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Ben H Fraser
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, NSW, Australia
| | - Marie-Claude Grégoire
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, Sydney, NSW, Australia
| | - Enikö Kövari
- Division of Geriatric Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
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30
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Sridharan S, Raffel J, Nandoskar A, Record C, Brooks DJ, Owen D, Sharp D, Muraro PA, Gunn R, Nicholas R. Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 21:935-944. [PMID: 30796709 DOI: 10.1007/s11307-019-01323-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurements of non-displaceable binding (VND) of positron emission tomography (PET) ligands are not often made in vivo in humans because they require ligands to displace binding to target receptors and there are few readily available, safe ones to use. A technique to measure VND for ligands for the 18-kDa translocator protein (TSPO) has recently been developed which compares the total volume of distribution (VT) before and after administration of the TSPO ligand XBD173. Here, we used XBD173 with an occupancy plot to quantify VND for two TSPO radiotracers, [18F]GE-180 and [11C]PBR28, in cohorts of people with multiple sclerosis (MS). Additionally, we compared plots of subjects carrying high (HAB) or mixed binding (MAB) affinity polymorphisms of TSPO to estimate VND without receptor blockade. PROCEDURES Twelve people with MS underwent baseline MRI and 90-min dynamic [18F]GE-180 PET or [11C]PBR28 PET (n = 6; three HAB, three MAB each). Arterial blood sampling was used to generate plasma input functions for the two-tissue compartment model. VND was calculated using two independent methods: the occupancy plot (by modelling the differences in signal post XBD173) and the polymorphism plot (by modelling the differences in signal across presence and absence of rs6971 genotypes). RESULTS Whole brain VT (mean ± standard deviation) was 0.29 ± 0.17 ml/cm3 for [18F]GE-180 and 5.01 ± 1.88 ml/cm3 for [11C]PBR28. Using the occupancy and polymorphism plots respectively, VND for [18F]GE-180 was 0.11 ml/cm3 (95 % CI = 0.02, 0.16) and 0.20 ml/cm3 (0.16, 0.34), accounting for, on average, 55 % of VT in the whole brain. For [11C]PBR28, these values were 3.81 ml/cm3 (3.02, 4.21) and 3.49 ml/cm3 (1.38, 4.27), accounting for 67 % of average whole brain VT. CONCLUSIONS Although VT for [18F]GE-180 is low, indicating low brain penetration, half the signal shown by MS subjects reflected specific TSPO binding. VT for [11C]PBR28 was higher and two thirds of the binding was non-specific. No brain ROIs were devoid of specific signal, further confirming that true reference tissue approaches are potentially problematic for estimating TSPO levels.
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Affiliation(s)
- Sujata Sridharan
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Joel Raffel
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Ashwini Nandoskar
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Chris Record
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David J Brooks
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle upon Tyne University, Newcastle upon Tyne, UK
| | - David Owen
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David Sharp
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Paolo A Muraro
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | | | - Richard Nicholas
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
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31
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Van Camp N, Balbastre Y, Herard AS, Lavisse S, Tauber C, Wimberley C, Guillermier M, Berniard A, Gipchtein P, Jan C, Badin RA, Delzescaux T, Hantraye P, Bonvento G. Assessment of simplified methods for quantification of [ 18F]-DPA-714 using 3D whole-brain TSPO immunohistochemistry in a non-human primate. J Cereb Blood Flow Metab 2020; 40:1103-1116. [PMID: 31238764 PMCID: PMC7181080 DOI: 10.1177/0271678x19859034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The 18 kDa translocator protein (TSPO) is the main molecular target to image neuroinflammation by positron emission tomography (PET). However, TSPO-PET quantification is complex and none of the kinetic modelling approaches has been validated using a voxel-by-voxel comparison of TSPO-PET data with the actual TSPO levels of expression. Here, we present a single case study of binary classification of in vivo PET data to evaluate the statistical performance of different TSPO-PET quantification methods. To that end, we induced a localized and adjustable increase of TSPO levels in a non-human primate brain through a viral-vector strategy. We then performed a voxel-wise comparison of the different TSPO-PET quantification approaches providing parametric [18F]-DPA-714 PET images, with co-registered in vitro three-dimensional TSPO immunohistochemistry (3D-IHC) data. A data matrix was extracted from each brain hemisphere, containing the TSPO-IHC and TSPO-PET data for each voxel position. Each voxel was then classified as false or true, positive or negative after comparison of the TSPO-PET measure to the reference 3D-IHC method. Finally, receiver operating characteristic curves (ROC) were calculated for each TSPO-PET quantification method. Our results show that standard uptake value ratios using cerebellum as a reference region (SUVCBL) has the most optimal ROC score amongst all non-invasive approaches.
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Affiliation(s)
- Nadja Van Camp
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Yaël Balbastre
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Anne-Sophie Herard
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Sonia Lavisse
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Clovis Tauber
- UMR Inserm U 1253 - Imagerie et Cerveau (iBrain) - University of Tours, Tours, France
| | - Catriona Wimberley
- Edinburgh Imaging Facility QMRI, The University of Edinburgh, Edinburgh, UK
| | - Martine Guillermier
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Aurélie Berniard
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Pauline Gipchtein
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Caroline Jan
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Romina Aron Badin
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Thierry Delzescaux
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Philippe Hantraye
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Gilles Bonvento
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut François Jacob, Molecular Imaging Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
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32
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Tong J, Williams B, Rusjan PM, Mizrahi R, Lacapère JJ, McCluskey T, Furukawa Y, Guttman M, Ang LC, Boileau I, Meyer JH, Kish SJ. Concentration, distribution, and influence of aging on the 18 kDa translocator protein in human brain: Implications for brain imaging studies. J Cereb Blood Flow Metab 2020; 40:1061-1076. [PMID: 31220997 PMCID: PMC7181090 DOI: 10.1177/0271678x19858003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Positron emission tomography (PET) imaging of the translocator protein (TSPO) is widely used as a biomarker of microglial activation. However, TSPO protein concentration in human brain has not been optimally quantified nor has its regional distribution been compared to TSPO binding. We determined TSPO protein concentration, change with age, and regional distribution by quantitative immunoblotting in autopsied human brain. Brain TSPO protein concentration (>0.1 ng/µg protein) was higher than those reported by in vitro binding assays by at least 2 to 70 fold. TSPO protein distributed widely in both gray and white matter regions, with distribution in major gray matter areas ranked generally similar to that of PET binding in second-generation radiotracer studies. TSPO protein concentration in frontal cortex was high at birth, declined precipitously during the first three months, and increased modestly during adulthood/senescence (10%/decade; vs. 30% for comparison astrocytic marker GFAP). As expected, TSPO protein levels were significantly increased (+114%) in degenerating putamen in multiple system atrophy, providing further circumstantial support for TSPO as a gliosis marker. Overall, findings show some similarities between TSPO protein and PET binding characteristics in the human brain but also suggest that part of the TSPO protein pool might be less available for radioligand binding.
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Affiliation(s)
- Junchao Tong
- Preclinical Imaging, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Junchao Tong, Preclinical Imaging, Centre
for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8,
Canada.
| | - Belinda Williams
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Pablo M. Rusjan
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Romina Mizrahi
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités-UPMC University of
Paris 06, Département de Chimie, École Normale Supérieure-PSL Research University,
Paris, France
| | - Tina McCluskey
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Yoshiaki Furukawa
- Department of Neurology, Juntendo Tokyo
Koto Geriatric Medical Center, and Faculty of Medicine, University & Post
Graduate University of Juntendo, Tokyo, Japan
| | - Mark Guttman
- Centre for Movement Disorders, Toronto,
Ontario, Canada
| | - Lee-Cyn Ang
- Division of Neuropathology, London
Health Science Centre, University of Western Ontario, London, Ontario, Canada
| | - Isabelle Boileau
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Jeffrey H Meyer
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Stephen J Kish
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
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33
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Dimitrova-Shumkovska J, Krstanoski L, Veenman L. Diagnostic and Therapeutic Potential of TSPO Studies Regarding Neurodegenerative Diseases, Psychiatric Disorders, Alcohol Use Disorders, Traumatic Brain Injury, and Stroke: An Update. Cells 2020; 9:cells9040870. [PMID: 32252470 PMCID: PMC7226777 DOI: 10.3390/cells9040870] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 02/08/2023] Open
Abstract
Neuroinflammation and cell death are among the common symptoms of many central nervous system diseases and injuries. Neuroinflammation and programmed cell death of the various cell types in the brain appear to be part of these disorders, and characteristic for each cell type, including neurons and glia cells. Concerning the effects of 18-kDa translocator protein (TSPO) on glial activation, as well as being associated with neuronal cell death, as a response mechanism to oxidative stress, the changes of its expression assayed with the aid of TSPO-specific positron emission tomography (PET) tracers' uptake could also offer evidence for following the pathogenesis of these disorders. This could potentially increase the number of diagnostic tests to accurately establish the stadium and development of the disease in question. Nonetheless, the differences in results regarding TSPO PET signals of first and second generations of tracers measured in patients with neurological disorders versus healthy controls indicate that we still have to understand more regarding TSPO characteristics. Expanding on investigations regarding the neuroprotective and healing effects of TSPO ligands could also contribute to a better understanding of the therapeutic potential of TSPO activity for brain damage due to brain injury and disease. Studies so far have directed attention to the effects on neurons and glia, and processes, such as death, inflammation, and regeneration. It is definitely worthwhile to drive such studies forward. From recent research it also appears that TSPO ligands, such as PK11195, Etifoxine, Emapunil, and 2-Cl-MGV-1, demonstrate the potential of targeting TSPO for treatments of brain diseases and disorders.
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Affiliation(s)
- Jasmina Dimitrova-Shumkovska
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
- Correspondence: (J.D.-S.); (L.V.)
| | - Ljupcho Krstanoski
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
| | - Leo Veenman
- Technion-Israel Institute of Technology, Faculty of Medicine, Rappaport Institute of Medical Research, 1 Efron Street, P.O. Box 9697, Haifa 31096, Israel
- Correspondence: (J.D.-S.); (L.V.)
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34
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Woodcock EA, Schain M, Cosgrove KP, Hillmer AT. Quantification of [ 11C]PBR28 data after systemic lipopolysaccharide challenge. EJNMMI Res 2020; 10:19. [PMID: 32166497 PMCID: PMC7067964 DOI: 10.1186/s13550-020-0605-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/31/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Lipopolysaccharide (LPS) is a classic immune stimulus. LPS combined with positron emission tomography (PET) 18 kDa translocator protein (TSPO) brain imaging provides a robust human laboratory model to study neuroimmune signaling. To evaluate optimal analysis of these data, this work compared the sensitivity of six quantification approaches. METHODS [11C]PBR28 data from healthy volunteers (N = 8) were collected before and 3 h after LPS challenge (1.0 ng/kg IV). Quantification approaches included total volume of distribution estimated with two tissue, and two tissue plus irreversible uptake in whole blood, compartment models (2TCM and 2TCM-1k, respectively) and multilinear analysis-1 (MA-1); binding potential estimated with simultaneous estimation (SIME); standardized uptake values (SUV); and SUV ratio (SUVR). RESULTS The 2TCM, 2TCM-1k, MA-1, and SIME approaches each yielded substantive effect sizes for LPS effects (partial η2 = 0.56-0.89, ps <. 05), whereas SUV and SUVR did not. CONCLUSION These findings highlight the importance of incorporating AIF measurements to quantify LPS-TSPO studies.
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Affiliation(s)
- Eric A Woodcock
- Department of Pscyhiatry, Yale School of Medicine, 300 George St., New Haven, CT, USA
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kelly P Cosgrove
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, 330 Cedar St., New Haven, CT, USA
| | - Ansel T Hillmer
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, 330 Cedar St., New Haven, CT, USA.
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35
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Sharma AA, Szaflarski JP. In Vivo Imaging of Neuroinflammatory Targets in Treatment-Resistant Epilepsy. Curr Neurol Neurosci Rep 2020; 20:5. [PMID: 32166626 DOI: 10.1007/s11910-020-1025-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW Recent evidence indicates that chronic, low-level neuroinflammation underlies epileptogenesis. Targeted imaging of key neuroinflammatory cells, receptors, and tissues may enable localizing epileptogenic onset zone, especially in those patients who are treatment-resistant and considered MRI-negative. Finding a specific, sensitive neuroimaging-based biomarker could aid surgical planning and improve overall prognosis in eligible patients. This article reviews recent research on in vivo imaging of neuroinflammatory targets in patients with treatment-resistant, non-lesional epilepsy. RECENT FINDINGS A number of advanced approaches based on imaging neuroinflammation are being implemented in order to assist localization of epileptogenic onset zone. The most exciting tools are based on radioligand-based nuclear imaging or revisiting of existing technology in novel ways. The greatest limitations stem from gaps in knowledge about the exact function of neuroinflammatory targets (e.g., neurotoxic or neuroprotective). Further, lingering questions about each approach's specificity, reliability, and sensitivity must be addressed, and clinical utility must be validated before any novel method is incorporated into mainstream clinical practice. Current applications of imaging neuroinflammation in humans are limited and underutilized, but offer hope for finding sensitive and specific neuroimaging-based biomarker(s). Future work necessitates appreciation of investigations to date, significant findings, and neuroinflammatory targets worth exploring further.
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Affiliation(s)
- Ayushe A Sharma
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA. .,Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.
| | - Jerzy P Szaflarski
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.,University of Alabama at Birmingham Epilepsy Center, Birmingham, AL, USA
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Nettis MA, Veronese M, Nikkheslat N, Mariani N, Lombardo G, Sforzini L, Enache D, Harrison NA, Turkheimer FE, Mondelli V, Pariante CM. PET imaging shows no changes in TSPO brain density after IFN-α immune challenge in healthy human volunteers. Transl Psychiatry 2020; 10:89. [PMID: 32152285 PMCID: PMC7063038 DOI: 10.1038/s41398-020-0768-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/18/2020] [Accepted: 02/24/2020] [Indexed: 12/22/2022] Open
Abstract
Depression is associated with peripheral inflammation, but its link with brain microglial activity remains unclear. In seven healthy males, we used repeated translocator protein-Positron Emission Tomography (TSPO-PET) dynamic scans with [11C]PBR28 to image brain microglial activation before and 24 h after the immune challenge interferon (IFN)-α. We also investigated the association between changes in peripheral inflammation, changes in microglial activity, and changes in mood. IFN-α administration decreased [11C]PBR28 PET tissue volume of distribution (Vt) across the brain (-20 ± 4%; t6 = 4.1, p = 0.01), but after correction for radioligand free-plasma fraction there were no longer any changes (+23 ± 31%; t = 0.1, p = 0.91). IFN-α increased serum IL-6 (1826 ± 513%, t6 = -7.5, p < 0.001), IL-7 (39 ± 12%, t6 = -3.6, p = 0.01), IL-10 (328 ± 48%, t6 = -12.8, p < 0.001), and IFN-γ (272 ± 64%, t6 = -7.0, p < 0.001) at 4-6 h, and increased serum TNF-α (49 ± 7.6%, t6 = -7.5, p < 0.001), IL-8 (39 ± 12%, t6 = -3.5, p = 0.013), and C-reactive protein (1320 ± 459%, t6 = -7.2, p < 0.001) at 24 h. IFN-α induced temporary mood changes and sickness symptoms after 4-6 h, measured as an increase in POMS-2 total mood score, confusion and fatigue, and a decrease in vigor and friendliness (all p ≤ 0.04). No association was found between changes in peripheral inflammation and changes in PET or mood measures. Our work suggests that brain TSPO-PET signal is highly dependent of inflammation-induced changes in ligand binding to plasma proteins. This limits its usefulness as a sensitive marker of neuroinflammation and consequently, data interpretation. Thus, our results can be interpreted as showing either that [11C]PBR28 is not sensitive enough under these conditions, or that there is simply no microglial activation in this model.
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Affiliation(s)
- M. A. Nettis
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK ,grid.451056.30000 0001 2116 3923National Institute for Health and Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK
| | - M. Veronese
- grid.451056.30000 0001 2116 3923National Institute for Health and Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK ,grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London Department of Neuroimaging, London, UK
| | - N. Nikkheslat
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK
| | - N. Mariani
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK
| | - G. Lombardo
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK
| | - L. Sforzini
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK ,Universita’ degli Studi di Milano, Psychiatry Unit, Department of Biomedical and Clinical Sciences, Luigi Sacco Hospital, Milan, Italy
| | - D. Enache
- grid.4714.60000 0004 1937 0626Karolinska Institute, Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Stockholm, Sweden
| | - N. A. Harrison
- grid.5600.30000 0001 0807 5670Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK
| | - F. E. Turkheimer
- grid.451056.30000 0001 2116 3923National Institute for Health and Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK ,grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London Department of Neuroimaging, London, UK
| | - V. Mondelli
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK ,grid.451056.30000 0001 2116 3923National Institute for Health and Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK
| | - C. M. Pariante
- grid.13097.3c0000 0001 2322 6764Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Department of Psychological Medicine, London, UK ,grid.451056.30000 0001 2116 3923National Institute for Health and Research Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK
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Vignal N, Boulay AC, San C, Cohen-Salmon M, Rizzo-Padoin N, Sarda-Mantel L, Declèves X, Cisternino S, Hosten B. Astroglial Connexin 43 Deficiency Protects against LPS-Induced Neuroinflammation: A TSPO Brain µPET Study with [ 18F]FEPPA. Cells 2020; 9:cells9020389. [PMID: 32046185 PMCID: PMC7072124 DOI: 10.3390/cells9020389] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/27/2020] [Accepted: 02/03/2020] [Indexed: 02/08/2023] Open
Abstract
Astroglial connexin 43 (Cx43) has been recognized as a crucial immunoregulating factor in the brain. Its inactivation leads to a continuous immune recruitment, cytokine expression modification and a specific humoral autoimmune response against the astrocytic extracellular matrix but without brain lesions or cell lysis. To assess the impact of Cx43 deletion on the brain’s inflammatory response, TSPO expression was studied by positron emission tomography (PET) imaging with a specific radioligand, [18F]FEPPA, in basal conditions or upon Lipopolysaccharides (LPS)-induced inflammatory challenge. Astroglial Cx43-deleted mice underwent [18F]FEPPA PET/CT dynamic imaging with or without LPS injection (5 mg/kg) 24 h before imaging. Quantification and pharmacokinetic data modelling with a 2TCM-1K compartment model were performed. After collecting the mice brains, TSPO expression was quantified and localized by Western blot and FISH analysis. We found that astroglial Cx43 deficiency does not significantly alter TSPO expression in the basal state as observed with [18F]FEPPA PET imaging, FISH and Western blot analysis. However, deletion of astrocyte Cx43 abolishes the LPS-induced TSPO increase. Autoimmune encephalopathy observed in astroglial Cx43-deleted mice does not involve TSPO overexpression. Consistent with previous studies showing a unique inflammatory status in the absence of astrocyte Cx43, we show that a deficient expression of astrocytic Cx43 protects the animals from LPS-induced neuroinflammation as addressed by TSPO expression.
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Affiliation(s)
- Nicolas Vignal
- Unité Claude Kellershohn, Institut de Recherche Saint-Louis, Faculté de Santé, Université de Paris, 75010 Paris, France; (N.V.); (N.R.-P.); (L.S.-M.)
- Therapeutic Optimisation in Neuropsychopharmacology, INSERM UMR-S 1144, 75005 Paris, France; (X.D.); (S.C.)
- Hôpital Lariboisière: Service de médecine nucléaire, Assistance Publique–Hôpitaux de Paris, 75010 Paris, France
| | - Anne-Cécile Boulay
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France; (A.-C.B.); (M.C.-S.)
| | - Carine San
- Hôpital Saint-Louis: Service Pharmacie, Assistance Publique–Hôpitaux de Paris, Unité Claude Kellershohn, 75010 Paris, France;
| | - Martine Cohen-Salmon
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, PSL Research University, 75005 Paris, France; (A.-C.B.); (M.C.-S.)
| | - Nathalie Rizzo-Padoin
- Unité Claude Kellershohn, Institut de Recherche Saint-Louis, Faculté de Santé, Université de Paris, 75010 Paris, France; (N.V.); (N.R.-P.); (L.S.-M.)
- Therapeutic Optimisation in Neuropsychopharmacology, INSERM UMR-S 1144, 75005 Paris, France; (X.D.); (S.C.)
- Hôpital Saint-Louis: Service Pharmacie, Assistance Publique–Hôpitaux de Paris, Unité Claude Kellershohn, 75010 Paris, France;
| | - Laure Sarda-Mantel
- Unité Claude Kellershohn, Institut de Recherche Saint-Louis, Faculté de Santé, Université de Paris, 75010 Paris, France; (N.V.); (N.R.-P.); (L.S.-M.)
- Hôpital Lariboisière: Service de médecine nucléaire, Assistance Publique–Hôpitaux de Paris, 75010 Paris, France
| | - Xavier Declèves
- Therapeutic Optimisation in Neuropsychopharmacology, INSERM UMR-S 1144, 75005 Paris, France; (X.D.); (S.C.)
- Faculté de Santé, Université de Paris, 75005 Paris, France
- Hôpital Cochin: Service de biologie du médicament et de toxicologie, Assistance Publique–Hôpitaux de Paris, 75014 Paris, France
| | - Salvatore Cisternino
- Therapeutic Optimisation in Neuropsychopharmacology, INSERM UMR-S 1144, 75005 Paris, France; (X.D.); (S.C.)
- Faculté de Santé, Université de Paris, 75005 Paris, France
- Hôpital Necker–Enfants Malades: Service de pharmacie, Assistance Publique–Hôpitaux de Paris, 75015 Paris, France
| | - Benoît Hosten
- Unité Claude Kellershohn, Institut de Recherche Saint-Louis, Faculté de Santé, Université de Paris, 75010 Paris, France; (N.V.); (N.R.-P.); (L.S.-M.)
- Therapeutic Optimisation in Neuropsychopharmacology, INSERM UMR-S 1144, 75005 Paris, France; (X.D.); (S.C.)
- Hôpital Saint-Louis: Service Pharmacie, Assistance Publique–Hôpitaux de Paris, Unité Claude Kellershohn, 75010 Paris, France;
- Correspondence: ; Tel.: +33-142-385-105
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Kubota K, Ogawa M, Ji B, Watabe T, Zhang MR, Suzuki H, Sawada M, Nishi K, Kudo T. Basic Science of PET Imaging for Inflammatory Diseases. PET/CT FOR INFLAMMATORY DISEASES 2020. [PMCID: PMC7418531 DOI: 10.1007/978-981-15-0810-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
FDG-PET/CT has recently emerged as a useful tool for the evaluation of inflammatory diseases too, in addition to that of malignant diseases. The imaging is based on active glucose utilization by inflammatory tissue. Autoradiography studies have demonstrated high FDG uptake in macrophages, granulocytes, fibroblasts, and granulation tissue. Especially, activated macrophages are responsible for the elevated FDG uptake in some types of inflammation. According to one study, after activation by lipopolysaccharide of cultured macrophages, the [14C]2DG uptake by the cells doubled, reaching the level seen in glioblastoma cells. In activated macrophages, increase in the expression of total GLUT1 and redistributions from the intracellular compartments toward the cell surface have been reported. In one rheumatoid arthritis model, following stimulation by hypoxia or TNF-α, the highest elevation of the [3H]FDG uptake was observed in the fibroblasts, followed by that in macrophages and neutrophils. As the fundamental mechanism of elevated glucose uptake in both cancer cells and inflammatory cells, activation of glucose metabolism as an adaptive response to a hypoxic environment has been reported, with transcription factor HIF-1α playing a key role. Inflammatory cells and cancer cells seem to share the same molecular mechanism of elevated glucose metabolism, lending support to the notion of usefulness of FDGPET/CT for the evaluation of inflammatory diseases, besides cancer.
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Song YS. Perspectives in TSPO PET Imaging for Neurologic Diseases. Nucl Med Mol Imaging 2019; 53:382-385. [PMID: 31867073 DOI: 10.1007/s13139-019-00620-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 01/30/2023] Open
Abstract
The translocator protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein, which has brought attention as a neuroinflammatory biomarker. Positron emission tomography (PET) imaging studies have been done for several decades, since neuroinflammation has been implicated as an important pathophysiology of several common neurologic disorders. However, despite numerous previous studies with positive findings, its clinical significance is not yet clear. Various attempts to overcome the limitations are ongoing, in order to bring acceptance for use in clinics.
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Affiliation(s)
- Yoo Sung Song
- Seoul National University Bundang Hospital, Seongnam, South Korea
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Hagens MHJ, Golla SSV, Janssen B, Vugts DJ, Beaino W, Windhorst AD, O’Brien-Brown J, Kassiou M, Schuit RC, Schwarte LA, de Vries HE, Killestein J, Barkhof F, van Berckel BNM, Lammertsma AA. The P2X 7 receptor tracer [ 11C]SMW139 as an in vivo marker of neuroinflammation in multiple sclerosis: a first-in man study. Eur J Nucl Med Mol Imaging 2019; 47:379-389. [PMID: 31705174 PMCID: PMC6974509 DOI: 10.1007/s00259-019-04550-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/24/2019] [Indexed: 12/21/2022]
Abstract
Purpose The novel PET tracer [11C]SMW139 binds with high affinity to the P2X7 receptor, which is expressed on pro-inflammatory microglia. The purposes of this first in-man study were to characterise pharmacokinetics of [11C]SMW139 in patients with active relapsing remitting multiple sclerosis (RRMS) and healthy controls (HC) and to evaluate its potential to identify in vivo neuroinflammation in RRMS. Methods Five RRMS patients and 5 age-matched HC underwent 90-min dynamic [11C]SMW139 PET scans, with online continuous and manual arterial sampling to generate a metabolite-corrected arterial plasma input function. Tissue time activity curves were fitted to single- and two-tissue compartment models, and the model that provided the best fits was determined using the Akaike information criterion. Results The optimal model for describing [11C]SMW139 kinetics in both RRMS and HC was a reversible two-tissue compartment model with blood volume parameter and with the dissociation rate k4 fixed to the whole-brain value. Exploratory group level comparisons demonstrated an increased volume of distribution (VT) and binding potential (BPND) in RRMS compared with HC in normal appearing brain regions. BPND in MS lesions was decreased compared with non-lesional white matter, and a further decrease was observed in gadolinium-enhancing lesions. In contrast, increased VT was observed in enhancing lesions, possibly resulting from disruption of the blood-brain barrier in active MS lesions. In addition, there was a high correlation between parameters obtained from 60- to 90-min datasets, although analyses using 60-min data led to a slight underestimation in regional VT and BPND values. Conclusions This first in-man study demonstrated that uptake of [11C]SMW139 can be quantified with PET using BPND as a measure for specific binding in healthy controls and RRMS patients. Additional studies are warranted for further clinical evaluation of this novel neuroinflammation tracer. Electronic supplementary material The online version of this article (10.1007/s00259-019-04550-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marloes H. J. Hagens
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Sandeep S. V. Golla
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Danielle J. Vugts
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Wissam Beaino
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Albert D. Windhorst
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | | | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, Australia
| | - Robert C. Schuit
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Lothar A. Schwarte
- Department of Anaesthesiology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Helga E. de Vries
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Joep Killestein
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Frederik Barkhof
- MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Institutes of Neurology and Healthcare Engineering, UCL Institute of Neurology, London, UK
| | - Bart N. M. van Berckel
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Adriaan A. Lammertsma
- Department of Radiology and Nuclear Medicine, Amsterdam Neuroscience, Amsterdam UMC - location VUmc, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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Marques TR, Ashok AH, Pillinger T, Veronese M, Turkheimer FE, Dazzan P, Sommer IE, Howes OD. Neuroinflammation in schizophrenia: meta-analysis of in vivo microglial imaging studies. Psychol Med 2019; 49:2186-2196. [PMID: 30355368 PMCID: PMC6366560 DOI: 10.1017/s0033291718003057] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/24/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Converging lines of evidence implicate an important role for the immune system in schizophrenia. Microglia are the resident immune cells of the central nervous system and have many functions including neuroinflammation, axonal guidance and neurotrophic support. We aimed to provide a quantitative review of in vivo PET imaging studies of microglia activation in patients with schizophrenia compared with healthy controls. METHODS Demographic, clinical and imaging measures were extracted from each study and meta-analysis was conducted using a random-effects model (Hedge's g). The difference in 18-kDa translocator protein (TSPO) binding between patients with schizophrenia and healthy controls, as quantified by either binding potential (BP) or volume of distribution (VT), was used as the main outcome. Sub-analysis and sensitivity analysis were carried out to investigate the effects of genotype, ligand and illness stage. RESULTS In total, 12 studies comprising 190 patients with schizophrenia and 200 healthy controls met inclusion criteria. There was a significant elevation in tracer binding in schizophrenia patients relative to controls when BP was used as an outcome measure, (Hedge's g = 0.31; p = 0.03) but no significant differences when VT was used (Hedge's g = -0.22; p = 0.29). CONCLUSIONS In conclusion, there is evidence for moderate elevations in TSPO tracer binding in grey matter relative to other brain tissue in schizophrenia when using BP as an outcome measure, but no difference when VT is the outcome measure. We discuss the relevance of these findings as well as the methodological issues that may underlie the contrasting difference between these outcomes.
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Affiliation(s)
- Tiago Reis Marques
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Du Cane Road, London W12 0NN, UK
- Psychiatric Imaging Group, London Institute of Medical Sciences (LMS), Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Abhishekh H Ashok
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Du Cane Road, London W12 0NN, UK
- Psychiatric Imaging Group, London Institute of Medical Sciences (LMS), Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
| | - Toby Pillinger
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
| | - Federico E. Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
| | - Paola Dazzan
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
| | - Iris E.C. Sommer
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Oliver D Howes
- Psychiatric Imaging Group, MRC Clinical Sciences Centre, Du Cane Road, London W12 0NN, UK
- Psychiatric Imaging Group, London Institute of Medical Sciences (LMS), Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, UK
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Gui Y, Marks JD, Das S, Hyman BT, Serrano-Pozo A. Characterization of the 18 kDa translocator protein (TSPO) expression in post-mortem normal and Alzheimer's disease brains. Brain Pathol 2019; 30:151-164. [PMID: 31276244 PMCID: PMC6904423 DOI: 10.1111/bpa.12763] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) is a widely used target for microglial PET imaging radioligands, but its expression in post-mortem normal and diseased human brain is not well described. We aimed at characterizing the TSPO expression in human control (CTRL) and Alzheimer's disease (AD) brains. Specifically, we sought to: (1) define the cell type(s) expressing TSPO; (2) compare tspo mRNA and TSPO levels between AD and CTRL brains; (3) correlate TSPO levels with quantitative neuropathological measures of reactive glia and AD neuropathological changes; and (4) investigate the effects of the TSPO rs6971 SNP on tspo mRNA and TSPO levels, glial responses and AD neuropathological changes. We performed quantitative immunohistochemistry and Western blot in post-mortem brain samples from CTRL and AD subjects, as well as analysis of publicly available mouse and human brain RNA-Seq datasets. We found that: (1) TSPO is expressed not just in microglia, but also in astrocytes, endothelial cells and vascular smooth muscle cells; (2) there is substantial overlap of tspo mRNA and TSPO levels between AD and CTRL subjects and in TSPO levels between temporal neocortex and white matter in both groups; (3) TSPO cortical burden does not correlate with the burden of activated microglia or reactive astrocytes, Aβ plaques or neurofibrillary tangles, or the cortical thickness; (4) the TSPO rs6971 SNP does not significantly impact tspo mRNA or TSPO levels, the magnitude of glial responses, the cortical thickness, or the burden of AD neuropathological changes. These results could inform ongoing efforts toward the development of reactive glia-specific PET radioligands.
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Affiliation(s)
- Yaxing Gui
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Department of Neurology, Sir Run Run Shaw Hospital of Zhejiang University, Zhejiang, China
| | - Jordan D Marks
- Department of Neurology, Massachusetts General Hospital, Boston, MA
| | - Sudeshna Das
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Harvard Medical School, Boston, MA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Harvard Medical School, Boston, MA
| | - Alberto Serrano-Pozo
- Department of Neurology, Massachusetts General Hospital, Boston, MA.,Harvard Medical School, Boston, MA
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Dani M, Wood M, Mizoguchi R, Fan Z, Walker Z, Morgan R, Hinz R, Biju M, Kuruvilla T, Brooks DJ, Edison P. Microglial activation correlates in vivo with both tau and amyloid in Alzheimer's disease. Brain 2019; 141:2740-2754. [PMID: 30052812 DOI: 10.1093/brain/awy188] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 05/29/2018] [Indexed: 12/30/2022] Open
Abstract
Alzheimer's disease is characterized by the histopathological presence of amyloid-β plaques and tau-containing neurofibrillary tangles. Microglial activation is also a recognized pathological component. The relationship between microglial activation and protein aggregation is still debated. We investigated the relationship between amyloid plaques, tau tangles and activated microglia using PET imaging. Fifty-one subjects (19 healthy controls, 16 mild cognitive impairment and 16 Alzheimer's disease subjects) participated in the study. All subjects had neuropsychometric testing, MRI, amyloid (18F-flutemetamol), and microglial (11C-PBR28) PET. All subjects with mild cognitive impairment and Alzheimer's disease and eight of the controls had tau (18F-AV1451) PET. 11C-PBR28 PET was analysed using Logan graphical analysis with an arterial plasma input function, while 18F-flutemetamol and 18F-AV1451 PET were analysed as target:cerebellar ratios to create parametric standardized uptake value ratio maps. Biological parametric mapping in the Statistical Parametric Mapping platform was used to examine correlations between uptake of tracers at a voxel-level. There were significant widespread clusters of positive correlation between levels of microglial activation and tau aggregation in both the mild cognitive impairment (amyloid-positive and amyloid-negative) and Alzheimer's disease subjects. The correlations were stronger in Alzheimer's disease than in mild cognitive impairment, suggesting that these pathologies increase together as disease progresses. Levels of microglial activation and amyloid deposition were also correlated, although in a different spatial distribution; correlations were stronger in mild cognitive impairment than Alzheimer's subjects, in line with a plateauing of amyloid load with disease progression. Clusters of positive correlations between microglial activation and protein aggregation often targeted similar areas of association cortex, indicating that all three processes are present in specific vulnerable brain areas. For the first time using PET imaging, we show that microglial activation can correlate with both tau aggregation and amyloid deposition. This confirms the complex relationship between these processes. These results suggest that preventative treatment for Alzheimer's disease should target all three processes.
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Affiliation(s)
- Melanie Dani
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Melanie Wood
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Ruth Mizoguchi
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zhen Fan
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zuzana Walker
- Division of Psychiatry, University College London, UK.,Essex Partnership University NHS Foundation Trust, UK
| | | | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, UK
| | - Maya Biju
- Gether NHS Foundation Trust, Gloucester, UK
| | | | - David J Brooks
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK.,Department of Nuclear Medicine, Aarhus University, Denmark.,Institute of Neuroscience, University of Newcastle upon Tyne, UK
| | - Paul Edison
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
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Intrahepatic fluorine-18-fluorodeoxyglucose kinetics measured by least squares nonlinear computer modelling and Gjedde–Patlak–Rutland graphical analysis. Nucl Med Commun 2019; 40:675-683. [DOI: 10.1097/mnm.0000000000001023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Head-to-head comparison of 11C-PBR28 and 11C-ER176 for quantification of the translocator protein in the human brain. Eur J Nucl Med Mol Imaging 2019; 46:1822-1829. [DOI: 10.1007/s00259-019-04349-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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Tonietto M, Rizzo G, Veronese M, Borgan F, Bloomfield PS, Howes O, Bertoldo A. A Unified Framework for Plasma Data Modeling in Dynamic Positron Emission Tomography Studies. IEEE Trans Biomed Eng 2019; 66:1447-1455. [DOI: 10.1109/tbme.2018.2874308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rizzo G, Veronese M, Tonietto M, Bodini B, Stankoff B, Wimberley C, Lavisse S, Bottlaender M, Bloomfield PS, Howes O, Zanotti-Fregonara P, Turkheimer FE, Bertoldo A. Generalization of endothelial modelling of TSPO PET imaging: Considerations on tracer affinities. J Cereb Blood Flow Metab 2019; 39:874-885. [PMID: 29135382 PMCID: PMC6501510 DOI: 10.1177/0271678x17742004] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The 18 kDa translocator protein (TSPO) is a marker of microglia activation and the main target of positron emission tomography (PET) ligands for neuroinflammation. Previous works showed that accounting for TSPO endothelial binding improves PET quantification for [11C]PBR28, [18F]DPA714 and [11C]-R-PK11195. It is still unclear, however, whether the vascular signal is tracer-dependent. This work aims to explore the relationship between the TSPO vascular and tissue components for PET tracers with varying affinity, also assessing the impact of affinity towards the differentiability amongst kinetics and the ensuing ligand amenability to cluster analysis for the extraction of a reference region. First, we applied the compartmental model accounting for vascular binding to [11C]-R-PK11195 data from six healthy subjects. Then, we compared the [11C]-R-PK11195 vascular binding estimates with previously published values for [18F]DPA714 and [11C]PBR28. Finally, we determined the suitability for reference region extraction by calculating the angle between grey and white matter kinetics. Our results showed that endothelial binding is common to all TSPO tracers and proportional to their affinity. By consequence, grey and white matter kinetics were most similar for the radioligand with the highest affinity (i.e. [11C]PBR28), hence poorly suited for the extraction of a reference region using supervised clustering.
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Affiliation(s)
- Gaia Rizzo
- 1 Department of Information Engineering, Padova University, Padova, Italy
| | - Mattia Veronese
- 2 Department of Neuroimaging, King's College London, London, UK
| | - Matteo Tonietto
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France
| | - Benedetta Bodini
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France.,4 Assistance Publique des Hopitaux de Paris, APHP, Hôpital Saint Antoine, Paris, France
| | - Bruno Stankoff
- 3 UPMC, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié Salpêtrière, Sorbonne Universités, Paris, France.,4 Assistance Publique des Hopitaux de Paris, APHP, Hôpital Saint Antoine, Paris, France.,5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France
| | - Catriona Wimberley
- 5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France
| | - Sonia Lavisse
- 6 Département de Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Fontenay-aux-Roses, France.,7 Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Michel Bottlaender
- 5 IMIV, Inserm, CEA, Paris-Sud Univ, Université Paris Saclay, Orsay, France.,8 Neurospin, CEA, Gif-sur-Yvette, France
| | | | - Oliver Howes
- 9 Institute of Clinical Sciences, Imperial College London, London, UK.,10 Department of Psychosis Studies, King's College London, London, UK
| | - Paolo Zanotti-Fregonara
- 11 Houston Methodist Hospital, PET Core Facility, Research Institute, Stanley H. Appel Department of Neurology, Houston, Texas, USA
| | | | - Alessandra Bertoldo
- 1 Department of Information Engineering, Padova University, Padova, Italy.,12 Padua Neuroscience Center, University of Padova, Padova, Italy
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Best L, Ghadery C, Pavese N, Tai YF, Strafella AP. New and Old TSPO PET Radioligands for Imaging Brain Microglial Activation in Neurodegenerative Disease. Curr Neurol Neurosci Rep 2019; 19:24. [DOI: 10.1007/s11910-019-0934-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Da Silva T, Hafizi S, Rusjan PM, Houle S, Wilson AA, Prce I, Sailasuta N, Mizrahi R. GABA levels and TSPO expression in people at clinical high risk for psychosis and healthy volunteers: a PET-MRS study. J Psychiatry Neurosci 2019; 44:111-119. [PMID: 30255837 PMCID: PMC6397035 DOI: 10.1503/jpn.170201] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND γ-Aminobutyric acidergic (GABAergic) dysfunction and immune activation have been implicated in the pathophysiology of schizophrenia. Preclinical evidence suggests that inflammation-related abnormalities may contribute to GABAergic alterations in the brain, but this has never been investigated in vivo in humans. In this multimodal imaging study, we quantified cerebral GABA plus macromolecule (GABA+) levels in antipsychotic-naive people at clinical high risk for psychosis and in healthy volunteers. We investigated for the first time the association between GABA+ levels and expression of translocator protein 18 kDa (TSPO; a marker of microglial activation) using positron emission tomography (PET). METHODS Thirty-five people at clinical high risk for psychosis and 18 healthy volunteers underwent 3 T proton magnetic resonance spectroscopy to obtain GABA+ levels in the medial prefrontal cortex (mPFC). A subset (29 people at clinical high risk for psychosis and 15 healthy volunteers) also underwent a high-resolution [18F]FEPPA PET scan to quantify TSPO expression. Each participant was genotyped for the TSPO rs6971 polymorphism. RESULTS We found that GABA+ levels were significantly associated with TSPO expression in the mPFC (F1,40 = 10.45, p = 0.002). We found no significant differences in GABA+ levels in the mPFC (F1,51 = 0.00, p > 0.99) between people at clinical high risk for psychosis and healthy volunteers. We found no significant correlations between GABA+ levels or residuals of the association with TSPO expression and the severity of prodromal symptoms or cognition. LIMITATIONS Given the cross-sectional nature of this study, we could determine no cause-and-effect relationships for GABA alterations and TSPO expression. CONCLUSION Our findings suggest that TSPO expression is negatively associated with GABA+ levels in the prefrontal cortex, independent of disease status.
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Affiliation(s)
- Tania Da Silva
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Sina Hafizi
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Pablo M Rusjan
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Sylvain Houle
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Alan A Wilson
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Ivana Prce
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Napapon Sailasuta
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
| | - Romina Mizrahi
- From the Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Silva, Hafizi, Rusjan, Houle, Wilson, Prce, Sailasuta, Mizrahi); the Institute of Medical Science, University of Toronto, Toronto, Ont., Canada (Silva, Rusjan, Mizrahi); the Department of Psychiatry, University of Toronto, Toronto, Ont., Canada (Rusjan, Houle, Wilson, Mizrahi); and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ont., Canada (Rusjan, Houle, Sailasuta, Mizrahi)
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