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Alagaratnam J, Thornhill JP, Fan Z, Vera JH, Underwood J, Hall R, Searle G, Owen D, Edison P, Fidler S, Winston A. Differences in neuroinflammation in people who started antiretroviral treatment during primary versus chronic HIV infection: an 18kDa Translocator protein (TSPO) positron emission tomography (PET) study. J Neurovirol 2024:10.1007/s13365-024-01200-3. [PMID: 38575831 DOI: 10.1007/s13365-024-01200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 04/06/2024]
Abstract
Persistent inflammation is described in people with HIV (PWH) on antiretroviral treatment (ART). Early ART initiation is associated with reduced inflammation. We aimed to evaluate neuroinflammation, using translocator protein (TSPO) [11C]PBR28 PET neuroimaging in PWH who initiated ART during acute HIV (aPWH) versus chronic HIV infection (cPWH) versus a control population. This was a cross-sectional, observational study. All participants underwent [11C]PBR28 PET-CT neuroimaging. Using a two-tissue compartment model, total volume of distribution (VT) and distribution volume ratios (DVR) using cortical grey matter as a pseudo-reference region at 20 regions of interest (ROIs) were calculated. Differences in VT and DVR were compared between groups using the Kruskall-Wallis test. Seventeen neuro-asymptomatic male PWH on ART (9 aPWH, 8 cPWH) and 8 male control participants (CPs) were included. Median (interquartile range, IQR) age was 40 (30, 46), 44 (41, 47) and 21 (20, 25) years in aPWH, cPWH and CPs, respectively. Median (IQR) CD4 (cells/µL) and CD4:CD8 were 687 (652, 1014) and 1.37 (1.24, 1.42), and 700 (500, 720) and 0.67 (0.64, 0.82) in aPWH and cPWH, respectively. Overall, no significant difference in VT and DVR were observed between the three groups at any ROIs. cPWH demonstrated a trend towards higher mean VT compared with aPWH and CPs at most ROIs. No significant differences in neuroinflammation, using [11C]PBR28 binding as a proxy, were identified between cPWH, aPWH and CPs. A trend towards lower absolute [11C]PBR28 binding was seen amongst aPWH and CPs, suggesting early ART may mitigate neuroinflammation.
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Affiliation(s)
- Jasmini Alagaratnam
- Department of Sexual Health & HIV, Chelsea & Westminster Hospital NHS Foundation Trust, London, UK.
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
| | - John P Thornhill
- Blizard Institute, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Zhen Fan
- Invicro, A Konica Minolta Company, London, UK
| | - Jaime H Vera
- Department of Global Health and Infection, Brighton and Sussex Medical School, London, UK
| | - Jonathan Underwood
- Division of Infection and Immunity, School of Medicine, Cardiff University, UHW Main Building, Heath Park, Cardiff, CF14 4XN, UK
| | - Rebecca Hall
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | | | - David Owen
- Department of Brain Sciences, Imperial College London, London, UK
| | - Paul Edison
- Department of Brain Sciences, Imperial College London, London, UK
| | - Sarah Fidler
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Alan Winston
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
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Truong TTT, Liu ZSJ, Panizzutti B, Dean OM, Berk M, Kim JH, Walder K. Use of gene regulatory network analysis to repurpose drugs to treat bipolar disorder. J Affect Disord 2024; 350:230-239. [PMID: 38190860 DOI: 10.1016/j.jad.2024.01.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/03/2023] [Accepted: 01/03/2024] [Indexed: 01/10/2024]
Abstract
BACKGROUND Bipolar disorder (BD) presents significant challenges in drug discovery, necessitating alternative approaches. Drug repurposing, leveraging computational techniques and expanding biomedical data, holds promise for identifying novel treatment strategies. METHODS This study utilized gene regulatory networks (GRNs) to identify significant regulatory changes in BD, using network-based signatures for drug repurposing. Employing the PANDA algorithm, we investigated the variations in transcription factor-GRNs between individuals with BD and unaffected individuals, incorporating binding motifs, protein interactions, and gene co-expression data. The differences in edge weights between BD and controls were then used as differential network signatures to identify drugs potentially targeting the disease-associated gene signature, employing the CLUEreg tool in the GRAND database. RESULTS Using a large RNA-seq dataset of 216 post-mortem brain samples from the CommonMind consortium, we constructed GRNs based on co-expression for individuals with BD and unaffected controls, involving 15,271 genes and 405 TFs. Our analysis highlighted significant influences of these TFs on immune response, energy metabolism, cell signalling, and cell adhesion pathways in the disorder. By employing drug repurposing, we identified 10 promising candidates potentially repurposed as BD treatments. LIMITATIONS Non-drug-naïve transcriptomics data, bulk analysis of BD samples, potential bias of GRNs towards well-studied genes. CONCLUSIONS Further investigation into repurposing candidates, especially those with preclinical evidence supporting their efficacy, like kaempferol and pramocaine, is warranted to understand their mechanisms of action and effectiveness in treating BD. Additionally, novel targets such as PARP1 and A2b offer opportunities for future research on their relevance to the disorder.
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Affiliation(s)
- Trang T T Truong
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia
| | - Zoe S J Liu
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia
| | - Bruna Panizzutti
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia
| | - Olivia M Dean
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia; Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Michael Berk
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia; Florey Institute of Neuroscience and Mental Health, Parkville, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, The Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, University of Melbourne, Parkville 3010, Australia
| | - Jee Hyun Kim
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia; Florey Institute of Neuroscience and Mental Health, Parkville, Australia
| | - Ken Walder
- Deakin University, IMPACT, The Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Geelong, Australia.
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Mantovani DBA, Pitombeira MS, Schuck PN, de Araújo AS, Buchpiguel CA, de Paula Faria D, M da Silva AM. Evaluation of Non-Invasive Methods for (R)-[ 11C]PK11195 PET Image Quantification in Multiple Sclerosis. J Imaging 2024; 10:39. [PMID: 38392087 PMCID: PMC10889702 DOI: 10.3390/jimaging10020039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/24/2024] Open
Abstract
This study aims to evaluate non-invasive PET quantification methods for (R)-[11C]PK11195 uptake measurement in multiple sclerosis (MS) patients and healthy controls (HC) in comparison with arterial input function (AIF) using dynamic (R)-[11C]PK11195 PET and magnetic resonance images. The total volume of distribution (VT) and distribution volume ratio (DVR) were measured in the gray matter, white matter, caudate nucleus, putamen, pallidum, thalamus, cerebellum, and brainstem using AIF, the image-derived input function (IDIF) from the carotid arteries, and pseudo-reference regions from supervised clustering analysis (SVCA). Uptake differences between MS and HC groups were tested using statistical tests adjusted for age and sex, and correlations between the results from the different quantification methods were also analyzed. Significant DVR differences were observed in the gray matter, white matter, putamen, pallidum, thalamus, and brainstem of MS patients when compared to the HC group. Also, strong correlations were found in DVR values between non-invasive methods and AIF (0.928 for IDIF and 0.975 for SVCA, p < 0.0001). On the other hand, (R)-[11C]PK11195 uptake could not be differentiated between MS patients and HC using VT values, and a weak correlation (0.356, p < 0.0001) was found between VTAIF and VTIDIF. Our study shows that the best alternative for AIF is using SVCA for reference region modeling, in addition to a cautious and appropriate methodology.
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Affiliation(s)
| | - Milena S Pitombeira
- Laboratory of Nuclear Medicine (LIM 43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
| | | | - Adriel S de Araújo
- Graduate Program in Computer Science, Pontificia Universidade Catolica do Rio Grande do Sul PUCRS, Porto Alegre 90619-900, Brazil
| | - Carlos Alberto Buchpiguel
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
- Laboratory of Nuclear Medicine (LIM 43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
| | - Daniele de Paula Faria
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
- Laboratory of Nuclear Medicine (LIM 43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
| | - Ana Maria M da Silva
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo 05403-911, Brazil
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Uzuegbunam BC, Rummel C, Librizzi D, Culmsee C, Hooshyar Yousefi B. Radiotracers for Imaging of Inflammatory Biomarkers TSPO and COX-2 in the Brain and in the Periphery. Int J Mol Sci 2023; 24:17419. [PMID: 38139248 PMCID: PMC10743508 DOI: 10.3390/ijms242417419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Inflammation involves the activation of innate immune cells and is believed to play an important role in the development and progression of both infectious and non-infectious diseases such as neurodegeneration, autoimmune diseases, pulmonary and cancer. Inflammation in the brain is marked by the upregulation of translocator protein (TSPO) in microglia. High TSPO levels are also found, for example, in macrophages in cases of rheumatoid arthritis and in malignant tumor cells compared to their relatively low physiological expression. The same applies for cyclooxgenase-2 (COX-2), which is constitutively expressed in the kidney, brain, thymus and gastrointestinal tract, but induced in microglia, macrophages and synoviocytes during inflammation. This puts TSPO and COX-2 in the spotlight as important targets for the diagnosis of inflammation. Imaging modalities, such as positron emission tomography and single-photon emission tomography, can be used to localize inflammatory processes and to track their progression over time. They could also enable the monitoring of the efficacy of therapy and predict its outcome. This review focuses on the current development of PET and SPECT tracers, not only for the detection of neuroinflammation, but also for emerging diagnostic measures in infectious and other non-infectious diseases such as rheumatic arthritis, cancer, cardiac inflammation and in lung diseases.
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Affiliation(s)
| | - Christoph Rummel
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, 35392 Gießen, Germany;
- Center for Mind Brain and Behavior, Universities Giessen and Marburg, 35043 Marburg, Germany;
| | - Damiano Librizzi
- Department of Nuclear Medicine, Philipps University of Marburg, 35043 Marburg, Germany;
| | - Carsten Culmsee
- Center for Mind Brain and Behavior, Universities Giessen and Marburg, 35043 Marburg, Germany;
- Institute of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, 35037 Marburg, Germany
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Brier MR, Taha F. Measuring Pathology in Patients with Multiple Sclerosis Using Positron Emission Tomography. Curr Neurol Neurosci Rep 2023; 23:479-488. [PMID: 37418219 DOI: 10.1007/s11910-023-01285-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2023] [Indexed: 07/08/2023]
Abstract
PURPOSE OF REVIEW Multiple sclerosis is characterized by a diverse and complex pathology. Clinical relapses, the hallmark of the disease, are accompanied by focal white matter lesions with intense inflammatory and demyelinating activity. Prevention of these relapses has been the major focus of pharmaceutical development, and it is now possible to dramatically reduce this inflammatory activity. Unfortunately, disability accumulation persists for many people living with multiple sclerosis owing to ongoing damage within existing lesions, pathology outside of discrete lesions, and other yet unknown factors. Understanding this complex pathological cascade will be critical to stopping progressive multiple sclerosis. Positron emission tomography uses biochemically specific radioligands to quantitatively measure pathological processes with molecular specificity. This review examines recent advances in the understanding of multiple sclerosis facilitated by positron emission tomography and identifies future avenues to expand understanding and treatment options. RECENT FINDINGS An increasing number of radiotracers allow for the quantitative measurement of inflammatory abnormalities, de- and re-myelination, and metabolic disruption associated with multiple sclerosis. The studies have identified contributions of ongoing, smoldering inflammation to accumulating tissue injury and clinical worsening. Myelin studies have quantified the dynamics of myelin loss and recovery. Lastly, metabolic changes have been found to contribute to symptom worsening. The molecular specificity facilitated by positron emission tomography in people living with multiple sclerosis will critically inform efforts to modulate the pathology leading to progressive disability accumulation. Existing studies show the power of this approach applied to multiple sclerosis. This armamentarium of radioligands allows for new understanding of how the brain and spinal cord of people is impacted by multiple sclerosis.
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Affiliation(s)
- Matthew R Brier
- Department of Neurology, John L Trotter MS Center, Washington University in St. Louis, St. Louis, USA.
| | - Farris Taha
- Department of Neurology, Medical University of South Carolina, Charleston, USA
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Ceyzériat K, Nicolaides A, Amossé Q, Fossey C, Cailly T, Fabis F, Garibotto V, Escartin C, Tournier BB, Millet P. Reactive astrocytes mediate TSPO overexpression in response to sustained CNTF exposure in the rat striatum. Mol Brain 2023; 16:57. [PMID: 37408083 DOI: 10.1186/s13041-023-01041-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 06/01/2023] [Indexed: 07/07/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) is a classical marker of neuroinflammation targeted for in vivo molecular imaging. Microglial cells were originally thought to be the only source of TSPO overexpression but astrocytes, neurons and endothelial cells can also up-regulate TSPO depending on the pathological context. This study aims to determine the cellular origin of TSPO overexpression in a simplified model of neuroinflammation and to identify the molecular pathways involved. This is essential to better interpret TSPO molecular imaging in preclinical and clinical settings. We used lentiviral vectors (LV) to overexpress the ciliary neurotrophic factor (CNTF) in the right striatum of 2-month-old Sprague Dawley rats. A LV encoding for β-Galactosidase (LV-LacZ) was used as control. One month later, TSPO expression was measured by single-photon emission computed tomography (SPECT) imaging using [125I]CLINDE. The fluorescence-activated cell sorting to radioligand-treated tissue (FACS-RTT) method was used to quantify TSPO levels in acutely sorted astrocytes, microglia, neurons and endothelial cells. A second cohort was injected with LV-CNTF and a LV encoding suppressor of cytokine signaling 3 (SOCS3), to inhibit the JAK-STAT3 pathway specifically in astrocytes. GFAP and TSPO expressions were quantified by immunofluorescence. We measured a significant increase in TSPO signal in response to CNTF by SPECT imaging. Using FACS-RTT, we observed TSPO overexpression in reactive astrocytes (+ 153 ± 62%) but also in microglia (+ 2088 ± 500%) and neurons (+ 369 ± 117%), accompanied by an increase in TSPO binding sites per cell in those three cell populations. Endothelial cells did not contribute to TSPO signal increase. Importantly, LV-SOCS3 reduced CNTF-induced astrocyte reactivity and decreased global TSPO immunoreactivity (-71% ± 30%), suggesting that TSPO overexpression is primarily mediated by reactive astrocytes. Overall, this study reveals that CNTF induces TSPO in multiple cell types in the rat striatum, through the JAK2-STAT3 pathway in astrocytes, identifying this cell type as the primary mediator of CNTF effects neuroinflammatory processes. Our results highlight the difficulty to interpret TSPO imaging in term of cellular origin without addition cellular analysis by FACS-RTT or quantitative immunostainings. Consequently, TSPO should only be used as a global marker of neuroinflammation.
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Affiliation(s)
- Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland.
- Department of Psychiatry, University of Geneva, Avenue de la Roseraie, 64, Geneva, 1205, Switzerland.
- CIBM Center for BioMedical Imaging, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
| | - Alekos Nicolaides
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Department of Psychiatry, University of Geneva, Avenue de la Roseraie, 64, Geneva, 1205, Switzerland
| | - Quentin Amossé
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Department of Psychiatry, University of Geneva, Avenue de la Roseraie, 64, Geneva, 1205, Switzerland
| | - Christine Fossey
- Normandie Univ, UNICAEN, Centre d'Études et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
| | - Thomas Cailly
- Normandie Univ, UNICAEN, Centre d'Études et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
- Department of Nuclear Medicine, CHU Cote de Nacre, Caen, France
- Normandie Univ, UNICAEN, IMOGERE, Caen, France
- Institut Blood and Brain @Caen-Normandie (BB@C) Boulevard Henri Becquerel, Caen, 14074, France
| | - Frédéric Fabis
- Normandie Univ, UNICAEN, Centre d'Études et de Recherche sur le Médicament de Normandie (CERMN), Caen, France
| | - Valentina Garibotto
- CIBM Center for BioMedical Imaging, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Division of nuclear medicine and molecular imaging, Diagnostic Department, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Carole Escartin
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, Gif-sur-Yvette, France
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Department of Psychiatry, University of Geneva, Avenue de la Roseraie, 64, Geneva, 1205, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Department of Psychiatry, University of Geneva, Avenue de la Roseraie, 64, Geneva, 1205, Switzerland
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Lapo Pais M, Jorge L, Martins R, Canário N, Xavier AC, Bernardes R, Abrunhosa A, Santana I, Castelo-Branco M. Textural properties of microglial activation in Alzheimer's disease as measured by (R)-[ 11C]PK11195 PET. Brain Commun 2023; 5:fcad148. [PMID: 37229217 PMCID: PMC10205176 DOI: 10.1093/braincomms/fcad148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 02/10/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023] Open
Abstract
Alzheimer's disease is the most common form of dementia worldwide, accounting for 60-70% of diagnosed cases. According to the current understanding of molecular pathogenesis, the main hallmarks of this disease are the abnormal accumulation of amyloid plaques and neurofibrillary tangles. Therefore, biomarkers reflecting these underlying biological mechanisms are recognized as valid tools for an early diagnosis of Alzheimer's disease. Inflammatory mechanisms, such as microglial activation, are known to be involved in Alzheimer's disease onset and progression. This activated state of the microglia is associated with increased expression of the translocator protein 18 kDa. On that account, PET tracers capable of measuring this signature, such as (R)-[11C]PK11195, might be instrumental in assessing the state and evolution of Alzheimer's disease. This study aims to investigate the potential of Gray Level Co-occurrence Matrix-based textural parameters as an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. To achieve this goal, kinetic and textural parameters were computed on (R)-[11C]PK11195 PET images of 19 patients with an early diagnosis of Alzheimer's disease and 21 healthy controls and submitted separately to classification using a linear support vector machine. The classifier built using the textural parameters showed no inferior performance compared to the classical kinetic approach, yielding a slightly larger classification accuracy (accuracy of 0.7000, sensitivity of 0.6957, specificity of 0.7059 and balanced accuracy of 0.6967). In conclusion, our results support the notion that textural parameters may be an alternative to conventional quantification using kinetic models in (R)-[11C]PK11195 PET images. The proposed quantification method makes it possible to use simpler scanning procedures, which increase patient comfort and convenience. We further speculate that textural parameters may also provide an alternative to kinetic analysis in (R)-[11C]PK11195 PET neuroimaging studies involving other neurodegenerative disorders. Finally, we recognize that the potential role of this tracer is not in diagnosis but rather in the assessment and progression of the diffuse and dynamic distribution of inflammatory cell density in this disorder as a promising therapeutic target.
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Affiliation(s)
- Marta Lapo Pais
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Lília Jorge
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ricardo Martins
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Nádia Canário
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Ana Carolina Xavier
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Rui Bernardes
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Antero Abrunhosa
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Isabel Santana
- Clinical Academic Centre of Coimbra (CACC), Faculty of Medicine (FMUC), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Neurology, Coimbra University Hospital, 3000-076 Coimbra, Portugal
| | - Miguel Castelo-Branco
- Correspondence to: Dr Miguel Castelo-Branco ICNAS/CIBIT, Pólo das Ciências da Saúde da Universidade de Coimbra Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail:
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Becker G, Debatisse J, Rivière M, Crola Da Silva C, Beaudoin-Gobert M, Eker O, Wateau O, Cho TH, Wiart M, Tremblay L, Costes N, Mérida I, Redouté J, Léon C, Langlois JB, Le Bars D, Lancelot S, Nighoghossian N, Mechtouff L, Canet-Soulas E. Spatio-Temporal Characterization of Brain Inflammation in a Non-human Primate Stroke Model Mimicking Endovascular Thrombectomy. Neurotherapeutics 2023; 20:789-802. [PMID: 36976495 PMCID: PMC10275847 DOI: 10.1007/s13311-023-01368-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
Reperfusion therapies in acute ischemic stroke have demonstrated their efficacy in promoting clinical recovery. However, ischemia/reperfusion injury and related inflammation remain a major challenge in patient clinical management. We evaluated the spatio-temporal evolution of inflammation using sequential clinical [11C]PK11195 PET-MRI in a non-human primate (NHP) stroke model mimicking endovascular thrombectomy (EVT) with a neuroprotective cyclosporine A (CsA) treatment. The NHP underwent a 110-min transient endovascular middle cerebral artery occlusion. We acquired [11C]PK11195 dynamic PET-MR imaging at baseline, 7 and 30 days after intervention. Individual voxel-wise analysis was performed thanks to a baseline scan database. We quantified [11C]PK11195 in anatomical regions and in lesioned areas defined on per-occlusion MR diffusion-weighted imaging and perfusion [15O2]H2OPET imaging. [11C]PK11195 parametric maps showed a clear uptake overlapping the lesion core at D7, which further increased at D30. Voxel-wise analysis identified individuals with significant inflammation at D30, with voxels located within the most severe diffusion reduction area during occlusion, mainly in the putamen. The quantitative analysis revealed that thalamic inflammation lasted until D30 and was significantly reduced in the CsA-treated group compared to the placebo. In conclusion, we showed that chronic inflammation matched ADC decrease at occlusion time, a region exposed to an initial burst of damage-associated molecular patterns, in an NHP stroke model mimicking EVT. We described secondary thalamic inflammation and the protective effect of CsA in this region. We propose that major ADC drop in the putamen during occlusion may identify individuals who could benefit from early personalized treatment targeting inflammation.
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Affiliation(s)
- Guillaume Becker
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France.
| | - Justine Debatisse
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Margaux Rivière
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Claire Crola Da Silva
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Maude Beaudoin-Gobert
- Lyon Neuroscience Research Center, UMR5295, INSERM U1028, CNRS, Université Claude Bernard Lyon 1, Lyon, France
| | - Omer Eker
- UMR-5220, CREATIS, CNRS, INSERM U1206, Université Lyon 1, INSA Lyon, Villeurbanne, France
- , Hospices Civils de Lyon, Lyon, France
| | | | - Tae Hee Cho
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Marlène Wiart
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | - Léon Tremblay
- Cognitive Neuroscience Center, CNRS UMR5229, Université Claude Bernard Lyon 1, Lyon, France
| | | | | | | | - Christelle Léon
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
| | | | - Didier Le Bars
- , Hospices Civils de Lyon, Lyon, France
- CERMEP, Lyon, France
| | | | - Norbert Nighoghossian
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Laura Mechtouff
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
- , Hospices Civils de Lyon, Lyon, France
| | - Emmanuelle Canet-Soulas
- CarMeN Laboratory, INRAE U1397, INSERM U1060, Groupement Hospitalier Est, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69500, Lyon, Bron, France
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9
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Evidence of methylphenidate effect on mitochondria, redox homeostasis, and inflammatory aspects: Insights from animal studies. Prog Neuropsychopharmacol Biol Psychiatry 2022; 116:110518. [PMID: 35092763 DOI: 10.1016/j.pnpbp.2022.110518] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/22/2022]
Abstract
Methylphenidate (MPH) is a central nervous system (CNS) stimulant known for its effectiveness in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), a neuropsychiatric condition that has a high incidence in childhood and affects behavior and cognition. However, the increase in its use among individuals who do not present all the diagnostic criteria for ADHD has become a serious public health problem since the neurological and psychiatric consequences of this unrestricted use are not widely known. In addition, since childhood is a critical period for the maturation of the CNS, the high prescription of MPH for preschool children also raises several concerns. This review brings new perspectives on how MPH (in different doses, routes of administration and ages) affects the CNS, focusing on animal studies that evaluated changes in mitochondrial (bioenergetics), redox balance and apoptosis, as well as inflammatory parameters. MPH alters brain energy homeostasis, increasing glucose consumption and impairing the activity of enzymes in the Krebs cycle and electron transport chain, as well as ATP levels and Na+,K+-ATPase activity. MPH induces oxidative stress, increasing the levels of reactive oxygen and nitrogen species and altering enzymatic and non-enzymatic antioxidant defenses, which, consequently, is related to damage to proteins, lipids, and DNA. Among the harmful effects of MPH, studies also demonstrate its ability to induce inflammation as well as alter the apoptosis pathway. It is important to highlight that age, treatment time, administration route, and dose are factors that can influence MPH effects. However, young animals seem to be more susceptible to damage caused by MPH. It is possible that changes in mitochondrial function and markers of status oxidative, apoptosis and inflammation may be exerting important mechanisms associated with MPH toxicity and, therefore, the unrestricted use of this drug can cause brain damage.
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10
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Meyer JH, Braga J. Development and Clinical Application of Positron Emission Tomography Imaging Agents for Monoamine Oxidase B. Front Neurosci 2022; 15:773404. [PMID: 35280341 PMCID: PMC8914088 DOI: 10.3389/fnins.2021.773404] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Monoamine oxidase B (MAO-B) is a high-density protein in the brain mainly found on outer mitochondrial membranes, primarily in astroglia, but additionally in serotonergic neurons and in the substantia nigra in the midbrain. It is an enzyme that participates in the oxidative metabolism of important monoamines including dopamine, norepinephrine, benzylamine, and phenylethylamine. Elevated MAO-B density may be associated with astrogliosis and inhibiting MAO-B may reduce astrogliosis. MAO-B density is elevated in postmortem sampling of pathology for many neuropsychiatric diseases including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and alcohol use disorder. Initial development of positron emission tomography (PET) imaging agents focused on analogs of [11C]L-deprenyl, with the most commonly applied being the deuterium substituted [11C]L-deprenyl-D2. This latter radiotracer was modeled with an irreversible trapping compartment reflecting its irreversible binding to MAO-B. Subsequently, [11C]SL25.1188, a reversible binding MAO-B radioligand with outstanding properties including high specific binding and excellent reversibility was developed. [11C]SL25.1188 PET was applied to discover a substantive elevation of MAO-B binding in the prefrontal cortex in major depressive disorder (MDD) with an effect size of more than 1.5. Longer duration of MDD was associated with greater MAO-B binding throughout most gray matter regions in the brain, suggesting progressive astrogliosis. Important applications of [11C]L-deprenyl-D2 PET are detecting a 40% loss in radiotracer accumulation in cigarette smokers, and substantial occupancy of novel therapeutics like EVT301 and sembragiline. Given the number of diseases with elevations of MAO-B density and astrogliosis, and the advance of [11C]SL25.1188, clinical applications of MAO-B imaging are still at an early stage.
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Affiliation(s)
- Jeffrey H. Meyer
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- *Correspondence: Jeffrey H. Meyer,
| | - Joeffre Braga
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
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11
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Non-invasive quantification of acute macrophagic lung inflammation with [ 11C](R)-PK11195 using a three-tissue compartment kinetic model in experimental acute respiratory distress syndrome. Eur J Nucl Med Mol Imaging 2022; 49:2122-2136. [PMID: 35129652 DOI: 10.1007/s00259-022-05713-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/30/2022] [Indexed: 12/18/2022]
Abstract
PURPOSE Imaging of acute lung inflammation is pivotal to evaluate innovative ventilation strategies. We aimed to develop and validate a three-tissue compartment kinetic model (3TCM) of [11C](R)-PK11195 lung uptake in experimental acute respiratory distress syndrome (ARDS) to help quantify macrophagic inflammation, while accounting for the impact of its non-specific and irreversible uptake in lung tissues. MATERIAL AND METHODS We analyzed the data of 38 positron emission tomography (PET) studies performed in 21 swine with or without experimental ARDS, receiving general anesthesia and mechanical ventilation. Model input function was a plasma, metabolite-corrected, image-derived input function measured in the main pulmonary artery. Regional lung analysis consisted in applying both the 3TCM and the two-tissue compartment model (2TCM); in each region, the best model was selected using a selection algorithm with a goodness-of-fit criterion. Regional best model binding potentials (BPND) were compared to lung macrophage presence, semi-quantified in pathology. RESULTS The 3TCM was preferred in 142 lung regions (62%, 95% confidence interval: 56 to 69%). BPND determined by the 2TCM was significantly higher than the value computed with the 3TCM (overall median with interquartile range: 0.81 [0.44-1.33] vs. 0.60 [0.34-0.94], p < 0.02). Regional macrophage score was significantly associated with the best model BPND (p = 0.03). Regional BPND was significantly increased in the hyperinflated lung compartment, compared to the normally aerated one (median with interquartile range: 0.8 [0.6-1.7] vs. 0.6 [0.3-0.8], p = 0.03). CONCLUSION To assess the intensity and spatial distribution of acute macrophagic lung inflammation in the context of experimental ARDS with mechanical ventilation, PET quantification of [11C](R)-PK11195 lung uptake was significantly improved in most lung regions using the 3TCM. This new methodology offers the opportunity to non-invasively evaluate innovative ventilatory strategies aiming at controlling acute lung inflammation.
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12
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Jia H, Xie T. Tracers progress for positron emission tomography imaging of glial-related disease. J Biomed Res 2022; 36:321-335. [PMID: 36131689 PMCID: PMC9548440 DOI: 10.7555/jbr.36.20220017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glial cells play an essential part in the neuron system. They can not only serve as structural blocks in the human brain but also participate in many biological processes. Extensive studies have shown that astrocytes and microglia play an important role in neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, as well as glioma, epilepsy, ischemic stroke, and infections. Positron emission tomography is a functional imaging technique providing molecular-level information before anatomic changes are visible and has been widely used in many above-mentioned diseases. In this review, we focus on the positron emission tomography tracers used in pathologies related to glial cells, such as glioma, Alzheimer's disease, and neuroinflammation.
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Affiliation(s)
- Haoran Jia
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
| | - Tianwu Xie
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, China
- Tianwu Xie, Institute of Radiation Medicine, Fudan University, 2094 Xietu Road, Shanghai 200032, China. Tel: +86-21-64048363, E-mail:
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13
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Chauveau F, Becker G, Boutin H. Have (R)-[ 11C]PK11195 challengers fulfilled the promise? A scoping review of clinical TSPO PET studies. Eur J Nucl Med Mol Imaging 2021; 49:201-220. [PMID: 34387719 PMCID: PMC8712292 DOI: 10.1007/s00259-021-05425-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE The prototypical TSPO radiotracer (R)-[11C]PK11195 has been used in humans for more than thirty years to visualize neuroinflammation in several pathologies. Alternative radiotracers have been developed to improve signal-to-noise ratio and started to be tested clinically in 2008. Here we examined the scientific value of these "(R)-[11C]PK11195 challengers" in clinical research to determine if they could supersede (R)-[11C]PK11195. METHODS A systematic MEDLINE (PubMed) search was performed (up to end of year 2020) to extract publications reporting TSPO PET in patients with identified pathologies, excluding studies in healthy subjects and methodological studies. RESULTS Of the 288 publications selected, 152 used 13 challengers, and 142 used (R)-[11C]PK11195. Over the last 20 years, the number of (R)-[11C]PK11195 studies remained stable (6 ± 3 per year), but was surpassed by the total number of challenger studies for the last 6 years. In total, 3914 patients underwent a TSPO PET scan, and 47% (1851 patients) received (R)-[11C]PK11195. The 2 main challengers were [11C]PBR28 (24%-938 patients) and [18F]FEPPA (11%-429 patients). Only one-in-ten patients (11%-447) underwent 2 TSPO scans, among whom 40 (1%) were scanned with 2 different TSPO radiotracers. CONCLUSIONS Generally, challengers confirmed disease-specific initial (R)-[11C]PK11195 findings. However, while their better signal-to-noise ratio seems particularly useful in diseases with moderate and widespread neuroinflammation, most challengers present an allelic-dependent (Ala147Thr polymorphism) TSPO binding and genetic stratification is hindering their clinical implementation. As new challengers, insensitive to TSPO human polymorphism, are about to enter clinical evaluation, we propose this systematic review to be regularly updated (living review).
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Affiliation(s)
- Fabien Chauveau
- University of Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR5292, INSERM U1028, University Lyon 1, Lyon, France.
| | - Guillaume Becker
- GIGA - CRC In Vivo Imaging, University Liege, Liege, Belgium
- University of Lyon, CarMeN Laboratory, INSERM U1060, University Lyon 1, Hospices Civils Lyon, Lyon, France
| | - Hervé Boutin
- Faculty of Biology Medicine and Health, Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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14
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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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15
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Akerele MI, Zein SA, Pandya S, Nikolopoulou A, Gauthier SA, Raj A, Henchcliffe C, Mozley PD, Karakatsanis NA, Gupta A, Babich J, Nehmeh SA. Population-based input function for TSPO quantification and kinetic modeling with [ 11C]-DPA-713. EJNMMI Phys 2021; 8:39. [PMID: 33914185 PMCID: PMC8085191 DOI: 10.1186/s40658-021-00381-8] [Citation(s) in RCA: 3] [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: 01/20/2021] [Accepted: 03/29/2021] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Quantitative positron emission tomography (PET) studies of neurodegenerative diseases typically require the measurement of arterial input functions (AIF), an invasive and risky procedure. This study aims to assess the reproducibility of [11C]DPA-713 PET kinetic analysis using population-based input function (PBIF). The final goal is to possibly eliminate the need for AIF. MATERIALS AND METHODS Eighteen subjects including six healthy volunteers (HV) and twelve Parkinson disease (PD) subjects from two [11C]-DPA-713 PET studies were included. Each subject underwent 90 min of dynamic PET imaging. Five healthy volunteers underwent a test-retest scan within the same day to assess the repeatability of the kinetic parameters. Kinetic modeling was carried out using the Logan total volume of distribution (VT) model. For each data set, kinetic analysis was performed using a patient-specific AIF (PSAIF, ground-truth standard) and then repeated using the PBIF. PBIF was generated using the leave-one-out method for each subject from the remaining 17 subjects and after normalizing the PSAIFs by 3 techniques: (a) Weightsubject×DoseInjected, (b) area under AIF curve (AUC), and (c) Weightsubject×AUC. The variability in the VT measured with PSAIF, in the test-retest study, was determined for selected brain regions (white matter, cerebellum, thalamus, caudate, putamen, pallidum, brainstem, hippocampus, and amygdala) using the Bland-Altman analysis and for each of the 3 normalization techniques. Similarly, for all subjects, the variabilities due to the use of PBIF were assessed. RESULTS Bland-Altman analysis showed systematic bias between test and retest studies. The corresponding mean bias and 95% limits of agreement (LOA) for the studied brain regions were 30% and ± 70%. Comparing PBIF- and PSAIF-based VT estimate for all subjects and all brain regions, a significant difference between the results generated by the three normalization techniques existed for all brain structures except for the brainstem (P-value = 0.095). The mean % difference and 95% LOA is -10% and ±45% for Weightsubject×DoseInjected; +8% and ±50% for AUC; and +2% and ± 38% for Weightsubject×AUC. In all cases, normalizing by Weightsubject×AUC yielded the smallest % bias and variability (% bias = ±2%; LOA = ±38% for all brain regions). Estimating the reproducibility of PBIF-kinetics to PSAIF based on disease groups (HV/PD) and genotype (MAB/HAB), the average VT values for all regions obtained from PBIF is insignificantly higher than PSAIF (%difference = 4.53%, P-value = 0.73 for HAB; and %difference = 0.73%, P-value = 0.96 for MAB). PBIF also tends to overestimate the difference between PD and HV for HAB (% difference = 32.33% versus 13.28%) and underestimate it in MAB (%difference = 6.84% versus 20.92%). CONCLUSIONS PSAIF kinetic results are reproducible with PBIF, with variability in VT within that obtained for the test-retest studies. Therefore, VT assessed using PBIF-based kinetic modeling is clinically feasible and can be an alternative to PSAIF.
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Affiliation(s)
- Mercy I Akerele
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA.
| | - Sara A Zein
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Sneha Pandya
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | | | - Susan A Gauthier
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
- Department of Neurology, Weill Cornell Medical College, New York, NY, 10021, USA
- Feil Family Brain and Mind Institute, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Ashish Raj
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Claire Henchcliffe
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
- Department of Neurology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - P David Mozley
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | | | - Ajay Gupta
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - John Babich
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Sadek A Nehmeh
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
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Imaging Biomarkers for Monitoring the Inflammatory Redox Landscape in the Brain. Antioxidants (Basel) 2021; 10:antiox10040528. [PMID: 33800685 PMCID: PMC8065574 DOI: 10.3390/antiox10040528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/21/2021] [Accepted: 03/25/2021] [Indexed: 12/27/2022] Open
Abstract
Inflammation is one key process in driving cellular redox homeostasis toward oxidative stress, which perpetuates inflammation. In the brain, this interplay results in a vicious cycle of cell death, the loss of neurons, and leakage of the blood–brain barrier. Hence, the neuroinflammatory response fuels the development of acute and chronic inflammatory diseases. Interrogation of the interplay between inflammation, oxidative stress, and cell death in neurological tissue in vivo is very challenging. The complexity of the underlying biological process and the fragility of the brain limit our understanding of the cause and the adequate diagnostics of neuroinflammatory diseases. In recent years, advancements in the development of molecular imaging agents addressed this limitation and enabled imaging of biomarkers of neuroinflammation in the brain. Notable redox biomarkers for imaging with positron emission tomography (PET) tracers are the 18 kDa translocator protein (TSPO) and monoamine oxygenase B (MAO–B). These findings and achievements offer the opportunity for novel diagnostic applications and therapeutic strategies. This review summarizes experimental as well as established pharmaceutical and biotechnological tools for imaging the inflammatory redox landscape in the brain, and provides a glimpse into future applications.
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de Souza AM, Pitombeira MS, de Souza LE, Marques FLN, Buchpiguel CA, Real CC, de Paula Faria D. 11C-PK11195 plasma metabolization has the same rate in multiple sclerosis patients and healthy controls: a cross-sectional study. Neural Regen Res 2021; 16:2494-2498. [PMID: 33907039 PMCID: PMC8374550 DOI: 10.4103/1673-5374.313062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
11C-PK11195 is a positron emitter tracer used for Positron Emission Tomography (PET) imaging of innate immune cell activation in studies of neuroinflammatory diseases. For the image quantitative analysis, it is necessary to quantify the intact fraction of this tracer in the arterial plasma during imaging acquisition (plasma intact fraction). Due to the complexity and costs involved in this analysis it is important to evaluate the real necessity of individual analysis in each 11C-PK11195 PET imaging acquisition. The purpose of this study is to compare 11C-PK11195 plasma metabolization rate between healthy controls and multiple sclerosis (MS) patients and evaluate the interference of sex, age, treatment, and disease phenotype in the tracer intact fraction measured in arterial plasma samples. 11C-PK11195 metabolization rate in arterial plasma was quantified by high performance liquid chromatography in samples from MS patients (n = 50) and healthy controls (n = 23) at 20, 45, and 60 minutes after 11C-PK11195 injection. Analyses were also stratified by sex, age, treatment type, and MS phenotype. The results showed no significant differences in the metabolization rate of healthy controls and MS patients, or in the stratified samples. In conclusion, 11C-PK11195 metabolization has the same rate in patients with MS and healthy controls, which is not affected by sex, age, treatment, and disease phenotype. Thus, these findings could contribute to exempting the necessity for tracer metabolization determination in all 11C-PK11195 PET imaging acquisition, by using a population metabolization rate average. The study procedures were approved by the Ethics Committee for Research Projects Analysis of the Hospital das Clinicas of the University of Sao Paulo Medical School (approval No. 624.065) on April 23, 2014.
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Affiliation(s)
- Aline Morais de Souza
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Milena Sales Pitombeira
- Department of Neurology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Larissa Estessi de Souza
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Fabio Luiz Navarro Marques
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Carlos Alberto Buchpiguel
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Caroline Cristiano Real
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
| | - Daniele de Paula Faria
- Laboratory of Nuclear Medicine (LIM43), Department of Radiology and Oncology; Department of Neurology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, Brazil
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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] [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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19
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Wolf BJ, Brackhan M, Bascuñana P, Leiter I, Langer BLN, Ross TL, Bankstahl JP, Bankstahl M. TSPO PET Identifies Different Anti-inflammatory Minocycline Treatment Response in Two Rodent Models of Epileptogenesis. Neurotherapeutics 2020; 17:1228-1238. [PMID: 31970667 PMCID: PMC7609777 DOI: 10.1007/s13311-020-00834-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Epileptogenesis-associated brain inflammation might be a promising target to prevent or attenuate epileptogenesis. Positron emission tomography (PET) imaging targeting the translocator protein (TSPO) was applied here to quantify effects of different dosing regimens of the anti-inflammatory drug minocycline during the latent phase in two rodent models of epileptogenesis. After induction of epileptogenesis by status epilepticus (SE), rats were treated with minocycline for 7 days (25 or 50 mg/kg) and mice for 5 or 10 days (50 or 100 mg/kg). All animals were subjected to scans at 1 and 2 weeks post-SE. Radiotracer distribution was analyzed and statistical parametric mapping (SPM) was performed, as well as histological analysis of astroglial activation and neuronal cell loss. Atlas-based analysis of [18F]GE180 PET in rats revealed a dose-dependent regional decrease of TSPO expression at 2 weeks post-SE. Results of SPM analysis depicted a treatment effect already at 1 week post-SE in rats treated with the higher minocycline dose. In mice, TSPO PET imaging did not reveal any treatment effects whereas histology identified only a treatment-related reduction in dispersion of dentate gyrus neurons. TSPO PET served as an auspicious tool for temporal monitoring and quantification of anti-inflammatory effects during epileptogenesis. Importantly, the findings underline the need to applying more than one animal model to avoid missing treatment effects. For future studies, the setup is ready to be applied in combination with seizure monitoring to investigate the relationship between individual early treatment response and disease outcome.
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Affiliation(s)
- Bettina J Wolf
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Mirjam Brackhan
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Department of Pathology, Section of Neuropathology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Pablo Bascuñana
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Ina Leiter
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Hannover, Germany
| | - B Laura N Langer
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Tobias L Ross
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Department of Laboratory Animal Science, Hannover Medical School, Hannover, Germany
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20
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Plavén-Sigray P, Cervenka S. Meta-analytic studies of the glial cell marker TSPO in psychosis - a question of apples and pears? Psychol Med 2019; 49:1624-1628. [PMID: 30739609 PMCID: PMC6601355 DOI: 10.1017/s003329171800421x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- P Plavén-Sigray
- 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
| | - S 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
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21
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Stadulytė A, Alcaide-Corral CJ, Walton T, Lucatelli C, Tavares AAS. Analysis of PK11195 concentrations in rodent whole blood and tissue samples by rapid and reproducible chromatographic method to support target-occupancy PET studies. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1118-1119:33-39. [PMID: 31005772 PMCID: PMC6522057 DOI: 10.1016/j.jchromb.2019.04.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 12/24/2022]
Abstract
In Positron Emission Tomography (PET) research, it is important to assess not only pharmacokinetics of a radiotracer in vivo, but also of the drugs used in blocking/displacement PET studies. Typically, pharmacokinetic/pharmacodynamic (PK/PD) analyses of drugs used in rodent PET studies are based on population average pharmacokinetic profiles of the drugs due to limited blood volume withdrawal while simultaneously maintaining physiological homeostasis. This likely results in bias of PET data quantification, including unknown bias of target occupancy (TO) measurements. This study aimed to develop a High Performance Liquid Chromatography (HPLC) method for PK/PD quantification of drugs used in preclinical rodent PET research, specifically the translocator 18 kDa protein (TSPO) selective drug, PK11195, that used sub-millilitre blood volumes. The lowest detection limit for the proposed HPLC method ranged between 7.5 and 10 ng/mL depending on the method used to calculate the limit of detection, and the measured average relative standard deviation for intermediate precision was equal to 17.2%. Most importantly, we were able to demonstrate a significant difference between calculated PK11195 concentrations at 0.5, 1, 2, 3, 5, 15 and 30 min post-administration and individually measured whole blood levels (significance level range from p < 0.05 to p < 0.001; one-way ANOVA, Dunnet's post hoc test, p < 0.05). The HPLC method developed here uses sub-millilitre sample volumes to reproducibly assess PK/PD of PK11195 in rodent blood. This study highlights the importance of individually measured PK/PD drug concentrations when quantifying the TO from blocking/displacement rodent PET experiments.
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Affiliation(s)
- Agnė Stadulytė
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK.
| | - Carlos José Alcaide-Corral
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK
| | - Tashfeen Walton
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Imaging, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Christophe Lucatelli
- Edinburgh Imaging, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Adriana Alexandre S Tavares
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK
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22
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Kohno M, Link J, Dennis LE, McCready H, Huckans M, Hoffman WF, Loftis JM. Neuroinflammation in addiction: A review of neuroimaging studies and potential immunotherapies. Pharmacol Biochem Behav 2019; 179:34-42. [PMID: 30695700 DOI: 10.1016/j.pbb.2019.01.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/22/2019] [Accepted: 01/25/2019] [Indexed: 12/29/2022]
Abstract
Addiction is a worldwide public health problem and this article reviews scientific advances in identifying the role of neuroinflammation in the genesis, maintenance, and treatment of substance use disorders. With an emphasis on neuroimaging techniques, this review examines human studies of addiction using positron emission tomography to identify binding of translocator protein (TSPO), which is upregulated in reactive glial cells and activated microglia during pathological states. High TSPO levels have been shown in methamphetamine use but exhibits variable patterns in cocaine use. Alcohol and nicotine use, however, are associated with lower TSPO levels. We discuss how mechanistic differences at the neurotransmitter and circuit level in the neural effects of these agents and subsequent immune response may explain these observations. Finally, we review the potential of anti-inflammatory drugs, including ibudilast, minocycline, and pioglitazone, to ameliorate the behavioral and cognitive consequences of addiction.
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Affiliation(s)
- Milky Kohno
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Jeanne Link
- Center for Radiochemistry Research, Knight Cardiovascular Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA
| | - Laura E Dennis
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Holly McCready
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Marilyn Huckans
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Mental Health and Clinical Neurosciences Division, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - William F Hoffman
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Mental Health and Clinical Neurosciences Division, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Jennifer M Loftis
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA.
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23
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Kaunzner UW, Kang Y, Zhang S, Morris E, Yao Y, Pandya S, Hurtado Rua SM, Park C, Gillen KM, Nguyen TD, Wang Y, Pitt D, Gauthier SA. Quantitative susceptibility mapping identifies inflammation in a subset of chronic multiple sclerosis lesions. Brain 2019; 142:133-145. [PMID: 30561514 PMCID: PMC6308309 DOI: 10.1093/brain/awy296] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/21/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022] Open
Abstract
Chronic active multiple sclerosis lesions, characterized by a hyperintense rim of iron-enriched, activated microglia and macrophages, have been linked to greater tissue damage. Post-mortem studies have determined that chronic active lesions are primarily related to the later stages of multiple sclerosis; however, the occurrence of these lesions, and their relationship to earlier disease stages may be greatly underestimated. Detection of chronic active lesions across the patient spectrum of multiple sclerosis requires a validated imaging tool to accurately identify lesions with persistent inflammation. Quantitative susceptibility mapping provides efficient in vivo quantification of susceptibility changes related to iron deposition and the potential to identify lesions harbouring iron-laden inflammatory cells. The PET tracer 11C-PK11195 targets the translocator protein expressed by activated microglia and infiltrating macrophages. Accordingly, this study aimed to validate that lesions with a hyperintense rim on quantitative susceptibility mapping from both relapsing and progressive patients demonstrate a higher level of innate immune activation as measured on 11C-PK11195 PET. Thirty patients were enrolled in this study, 24 patients had relapsing remitting multiple sclerosis, six had progressive multiple sclerosis, and all patients had concomitant MRI with a gradient echo sequence and PET with 11C-PK11195. A total of 406 chronic lesions were detected, and 43 chronic lesions with a hyperintense rim on quantitative susceptibility mapping were identified as rim+ lesions. Susceptibility (relative to CSF) was higher in rim+ (2.42 ± 17.45 ppb) compared to rim- lesions (-14.6 ± 19.3 ppb, P < 0.0001). Among rim+ lesions, susceptibility within the rim (20.04 ± 14.28 ppb) was significantly higher compared to the core (-5.49 ± 14.44 ppb, P < 0.0001), consistent with the presence of iron. In a mixed-effects model, 11C-PK11195 uptake, representing activated microglia/macrophages, was higher in rim+ lesions compared to rim- lesions (P = 0.015). Validating our in vivo imaging results, multiple sclerosis brain slabs were imaged with quantitative susceptibility mapping and processed for immunohistochemistry. These results showed a positive translocator protein signal throughout the expansive hyperintense border of rim+ lesions, which co-localized with iron containing CD68+ microglia and macrophages. In conclusion, this study provides evidence that suggests that a hyperintense rim on quantitative susceptibility measure within a chronic lesion is a correlate for persistent inflammatory activity and that these lesions can be identified in the relapsing patients. Utilizing quantitative susceptibility measure to differentiate chronic multiple sclerosis lesion subtypes, especially chronic active lesions, would provide a method to assess the impact of these lesions on disease progression.
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Affiliation(s)
- Ulrike W Kaunzner
- Judith Jaffe Multiple Sclerosis Center, Weill Cornell Medicine, New York City, NY, USA
| | - Yeona Kang
- Department of Radiology/Nuclear Medicine, Weill Cornell Medicine, New York City, NY, USA
| | - Shun Zhang
- Cornell MRI Research Lab, New York City, NY, USA
| | - Eric Morris
- Judith Jaffe Multiple Sclerosis Center, Weill Cornell Medicine, New York City, NY, USA
| | - Yihao Yao
- Cornell MRI Research Lab, New York City, NY, USA
| | - Sneha Pandya
- Department of Radiology/Nuclear Medicine, Weill Cornell Medicine, New York City, NY, USA
| | - Sandra M Hurtado Rua
- Department of Mathematics, College of Sciences and Health Professions, Cleveland State University, Cleveland, OH, USA
| | - Calvin Park
- Yale Multiple Sclerosis Center, New Haven, CT, USA
| | | | | | - Yi Wang
- Cornell MRI Research Lab, New York City, NY, USA
| | - David Pitt
- Yale Multiple Sclerosis Center, New Haven, CT, USA
| | - Susan A Gauthier
- Judith Jaffe Multiple Sclerosis Center, Weill Cornell Medicine, New York City, NY, USA
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24
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Plavén-Sigray P, Matheson GJ, Cselényi Z, Jucaite A, Farde L, Cervenka S. Test-retest reliability and convergent validity of (R)-[ 11C]PK11195 outcome measures without arterial input function. EJNMMI Res 2018; 8:102. [PMID: 30498919 PMCID: PMC6265355 DOI: 10.1186/s13550-018-0455-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/02/2018] [Indexed: 12/29/2022] Open
Abstract
Purpose The PET radioligand (R)-[11C]PK11195 is used to quantify the 18-kDa translocator protein (TSPO), a marker for glial activation. Since there is no brain region devoid of TSPO, an arterial input function (AIF) is ideally required for quantification of binding. However, obtaining an AIF is experimentally demanding, is sometimes uncomfortable for participants, and can introduce additional measurement error during quantification. The objective of this study was to perform an evaluation of the test-retest reliability and convergent validity of techniques used for quantifying (R)-[11C]PK11195 binding without an AIF in clinical studies. Methods Data from six healthy individuals who participated in two PET examinations, 6 weeks apart, were analyzed. Regional non-displaceable binding potential (BPND) values were calculated using the simplified reference tissue model, with either cerebellum as reference region or a reference input derived using supervised cluster analysis (SVCA). Standardized uptake values (SUVs) were estimated for the time interval of 40–60 min. Results Test-retest reliability for BPND estimates were poor (80% of ICCs < 0.5). BPND estimates derived without an AIF were not correlated with BPND, total or specific distribution volume from the 2TCM using an AIF (all R2 < 12%). SUVs showed moderate reliability but no correlation to any other outcome measure. Conclusions Caution is warranted when interpreting patient-control comparisons employing (R)-[11C]PK11195 outcome measures obtained without an AIF. Electronic supplementary material The online version of this article (10.1186/s13550-018-0455-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pontus Plavén-Sigray
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.
| | - Granville James Matheson
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden
| | - Zsolt Cselényi
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Aurelija Jucaite
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Simon Cervenka
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden
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25
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Plavén-Sigray P, Schain M, Zanderigo F, Rabiner EA, Gunn RN, Ogden RT, Cervenka S. Accuracy and reliability of [ 11C]PBR28 specific binding estimated without the use of a reference region. Neuroimage 2018; 188:102-110. [PMID: 30500425 DOI: 10.1016/j.neuroimage.2018.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/06/2018] [Accepted: 11/16/2018] [Indexed: 12/22/2022] Open
Abstract
[11C]PBR28 is a positron emission tomography radioligand used to examine the expression of the 18 kDa translocator protein (TSPO). TSPO is located in glial cells and can function as a marker for immune activation. Since TSPO is expressed throughout the brain, no true reference region exists. For this reason, an arterial input function is required for accurate quantification of [11C]PBR28 binding and the most common outcome measure is the total distribution volume (VT). Notably, VT reflects both specific binding and non-displaceable binding. Therefore, estimates of specific binding, such as binding potential (e.g. BPND) and specific distribution volume (VS) should theoretically be more sensitive to underlying differences in TSPO expression. It is unknown, however, if unbiased and accurate estimates of these outcome measures are obtainable for [11C]PBR28. The Simultaneous Estimation (SIME) method uses time-activity-curves from multiple brain regions with the aim to obtain a brain-wide estimate of the non-displaceable distribution volume (VND), which can subsequently be used to improve the estimation of BPND and VS. In this study we evaluated the accuracy of SIME-derived VND, and the reliability of resulting estimates of specific binding for [11C]PBR28, using a combination of simulation experiments and in vivo studies in healthy humans. The simulation experiments, based on data from 54 unique [11C]PBR28 examinations, showed that VND values estimated using SIME were both precise and accurate. Data from a pharmacological competition challenge (n = 5) showed that SIME provided VND values that were on average 19% lower than those obtained using the Lassen plot, but similar to values obtained using the Likelihood-Estimation of Occupancy technique. Test-retest data (n = 11) showed that SIME-derived VS values exhibited good reliability and precision, while larger variability was observed in SIME-derived BPND values. The results support the use of SIME for quantifying specific binding of [11C]PBR28, and suggest that VS can be used in complement to the conventional outcome measure VT. Additional studies in patient cohorts are warranted.
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Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA
| | | | | | - Roger N Gunn
- Invicro LLC, London, UK; Division of Brain Sciences, Imperial College London, London, UK
| | - R Todd Ogden
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA; Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, USA
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
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26
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Koole M, Schmidt ME, Hijzen A, Ravenstijn P, Vandermeulen C, Van Weehaeghe D, Serdons K, Celen S, Bormans G, Ceusters M, Zhang W, Van Nueten L, Kolb H, de Hoon J, Van Laere K. 18F-JNJ-64413739, a Novel PET Ligand for the P2X7 Ion Channel: Radiation Dosimetry, Kinetic Modeling, Test-Retest Variability, and Occupancy of the P2X7 Antagonist JNJ-54175446. J Nucl Med 2018; 60:683-690. [PMID: 30262518 DOI: 10.2967/jnumed.118.216747] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/18/2018] [Indexed: 12/27/2022] Open
Abstract
The P2X7 receptor (P2X7R) is an adenosine triphosphate-gated ion channel that is predominantly expressed on microglial cells in the central nervous system. We report the clinical qualification of P2X7-specific PET ligand 18F-JNJ-64413739 in healthy volunteers, including dosimetry, kinetic modeling, test-retest variability, and blocking by the P2X7 antagonist JNJ-54175446. Methods: Whole-body dosimetry was performed in 3 healthy male subjects by consecutive whole-body PET/CT scanning, estimation of the normalized cumulated activity, and calculation of the effective dose using OLINDA (v1.1). Next, 5 healthy male subjects underwent a 120-min dynamic 18F-JNJ-64413739 PET/MRI scan with arterial blood sampling to determine the appropriate kinetic model. For this purpose, 1- and 2-tissue compartment models and Logan graphic analysis (LGA) were evaluated for estimating regional volumes of distribution (VT). PET/MRI scanning was repeated in 4 of these subjects to evaluate medium-term test-retest variability (interscan interval, 26-97 d). For the single-dose occupancy study, 8 healthy male subjects underwent baseline and postdose 18F-JNJ-64413739 PET/MRI scans 4-6 h after the administration of a single oral dose of JNJ-54175446 (dose range, 5-300 mg). P2X7 occupancies were estimated using a Lassen plot and regional baseline and postdose VT Results: The average (mean ± SD) effective dose was 22.0 ± 1.0 μSv/MBq. The 2-tissue compartment model was the most appropriate kinetic model, with LGA showing very similar results. Regional 2-tissue compartment model VT values were about 3 and were rather homogeneous across all brain regions, with slightly higher estimates for the thalamus, striatum, and brain stem. Between-subject VT variability was relatively high, with cortical VT showing an approximate 3-fold range across subjects. As for time stability, the acquisition time could be reduced to 90 min. The average regional test-retest variability values were 10.7% ± 2.2% for 2-tissue compartment model VT and 11.9% ± 2.2% for LGA VT P2X7 occupancy approached saturation for single doses of JNJ-54175446 higher than 50 mg, and no reference region could be identified. Conclusion: 18F-JNJ-64413739 is a suitable PET ligand for the quantification of P2X7R expression in the human brain. It can be used to provide insight into P2X7R expression in health and disease, to evaluate target engagement by P2X7 antagonists, and to guide dose selection.
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Affiliation(s)
- Michel Koole
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | - Anja Hijzen
- Janssen Research and Development, Beerse, Belgium
| | | | - Corinne Vandermeulen
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Donatienne Van Weehaeghe
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Kim Serdons
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Sofie Celen
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | | | - Wei Zhang
- Janssen Research and Development, Beerse, Belgium
| | | | | | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Koen Van Laere
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium .,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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27
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Plavén-Sigray P, Matheson GJ, Collste K, Ashok AH, Coughlin JM, Howes OD, Mizrahi R, Pomper MG, Rusjan P, Veronese M, Wang Y, Cervenka S. Positron Emission Tomography Studies of the Glial Cell Marker Translocator Protein in Patients With Psychosis: A Meta-analysis Using Individual Participant Data. Biol Psychiatry 2018; 84:433-442. [PMID: 29653835 PMCID: PMC7893597 DOI: 10.1016/j.biopsych.2018.02.1171] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/13/2018] [Accepted: 02/20/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Accumulating evidence suggests that the immune system may be an important target for new treatment approaches in schizophrenia. Positron emission tomography and radioligands binding to the translocator protein (TSPO), which is expressed in glial cells in the brain including immune cells, represents a potential method for patient stratification and treatment monitoring. This study examined whether patients with first-episode psychosis and schizophrenia had altered TSPO levels compared with healthy control subjects. METHODS PubMed was searched for studies comparing patients with psychosis with healthy control subjects using second-generation TSPO radioligands. The outcome measure was total distribution volume (VT), an index of TSPO levels, in frontal cortex, temporal cortex, and hippocampus. Bayes factors (BFs) were applied to examine the relative support for higher, lower, or no difference in patients' TSPO levels compared with healthy control subjects. RESULTS Five studies, with 75 participants with first-episode psychosis or schizophrenia and 77 healthy control subjects, were included. BFs showed strong support for lower VT in patients relative to no difference (all BFs > 32), or relative to higher VT (all BFs > 422), in all brain regions. From the posterior distributions, mean patient-control differences in standardized VT values were -0.48 for frontal cortex (95% credible interval [CredInt] = -0.88 to 0.09), -0.47 for temporal cortex (CredInt = -0.87 to -0.07), and -0.63 for hippocampus (CredInt = -1.00 to -0.25). CONCLUSIONS The lower levels of TSPO observed in patients may correspond to altered function or lower density of brain immune cells. Future studies should focus on investigating the underlying biological mechanisms and their relevance for treatment.
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Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden.
| | - Granville J Matheson
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
| | - Karin Collste
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
| | - Abhishekh H Ashok
- Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom; Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Oliver D Howes
- Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom; Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Romina Mizrahi
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Pablo Rusjan
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
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Kang Y, Mozley PD, Verma A, Schlyer D, Henchcliffe C, Gauthier SA, Chiao PC, He B, Nikolopoulou A, Logan J, Sullivan JM, Pryor KO, Hesterman J, Kothari PJ, Vallabhajosula S. Noninvasive PK11195-PET Image Analysis Techniques Can Detect Abnormal Cerebral Microglial Activation in Parkinson's Disease. J Neuroimaging 2018; 28:496-505. [PMID: 29727504 PMCID: PMC6174975 DOI: 10.1111/jon.12519] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 04/15/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Neuroinflammation has been implicated in the pathophysiology of Parkinson's disease (PD), which might be influenced by successful neuroprotective drugs. The uptake of [11 C](R)-PK11195 (PK) is often considered to be a proxy for neuroinflammation, and can be quantified using the Logan graphical method with an image-derived blood input function, or the Logan reference tissue model using automated reference region extraction. The purposes of this study were (1) to assess whether these noninvasive image analysis methods can discriminate between patients with PD and healthy volunteers (HVs), and (2) to establish the effect size that would be required to distinguish true drug-induced changes from system variance in longitudinal trials. METHODS The sample consisted of 20 participants with PD and 19 HVs. Two independent teams analyzed the data to compare the volume of distribution calculated using image-derived input functions (IDIFs), and binding potentials calculated using the Logan reference region model. RESULTS With all methods, the higher signal-to-background in patients resulted in lower variability and better repeatability than in controls. We were able to use noninvasive techniques showing significantly increased uptake of PK in multiple brain regions of participants with PD compared to HVs. CONCLUSION Although not necessarily reflecting absolute values, these noninvasive image analysis methods can discriminate between PD patients and HVs. We see a difference of 24% in the substantia nigra between PD and HV with a repeatability coefficient of 13%, showing that it will be possible to estimate responses in longitudinal, within subject trials of novel neuroprotective drugs.
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Affiliation(s)
| | | | | | - David Schlyer
- Weill Cornell MedicineNew YorkNY
- Brookhaven National LaboratoriesNY
| | | | | | | | - Bin He
- Weill Cornell MedicineNew YorkNY
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Meyer J. Novel Phenotypes Detectable with PET in Mood Disorders: Elevated Monoamine Oxidase A and Translocator Protein Level. PET Clin 2018; 12:361-371. [PMID: 28576173 DOI: 10.1016/j.cpet.2017.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As a result of high prevalence and high rates of treatment resistance, major depressive disorder has become the leading cause of death and disability in moderate-income to high-income nations. Poor targeting of phenotypes is a plausible reason for treatment resistance and PET imaging offers a unique role to identify phenotypes. Both increased monoamine oxidase A binding and greater translocator protein 18 kDa binding occur throughout the gray matter during major depressive episodes, including affect-modulating brain regions such as the prefrontal and anterior cingulate cortex, and are detectable with advanced radioligand technology for both of these targets.
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Affiliation(s)
- Jeffrey Meyer
- Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario M5T1R8, Canada.
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Cumming P, Burgher B, Patkar O, Breakspear M, Vasdev N, Thomas P, Liu GJ, Banati R. Sifting through the surfeit of neuroinflammation tracers. J Cereb Blood Flow Metab 2018; 38:204-224. [PMID: 29256293 PMCID: PMC5951023 DOI: 10.1177/0271678x17748786] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/26/2017] [Accepted: 11/09/2017] [Indexed: 01/09/2023]
Abstract
The first phase of molecular brain imaging of microglial activation in neuroinflammatory conditions began some 20 years ago with the introduction of [11C]-( R)-PK11195, the prototype isoquinoline ligand for translocator protein (18 kDa) (TSPO). Investigations by positron emission tomography (PET) revealed microgliosis in numerous brain diseases, despite the rather low specific binding signal imparted by [11C]-( R)-PK11195. There has since been enormous expansion of the repertoire of TSPO tracers, many with higher specific binding, albeit complicated by allelic dependence of the affinity. However, the specificity of TSPO PET for revealing microglial activation not been fully established, and it has been difficult to judge the relative merits of the competing tracers and analysis methods with respect to their sensitivity for detecting microglial activation. We therefore present a systematic comparison of 13 TSPO PET and single photon computed tomography (SPECT) tracers belonging to five structural classes, each of which has been investigated by compartmental analysis in healthy human brain relative to a metabolite-corrected arterial input. We emphasize the need to establish the non-displaceable binding component for each ligand and conclude with five recommendations for a standard approach to define the cellular distribution of TSPO signals, and to characterize the properties of candidate TSPO tracers.
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Affiliation(s)
- Paul Cumming
- School of Psychology and Counselling and IHBI, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- QIMR Berghofer Institute, Brisbane, Australia
| | - Bjorn Burgher
- QIMR Berghofer Institute, Brisbane, Australia
- Metro North Mental Health Service, Brisbane, Australia
| | - Omkar Patkar
- School of Psychology and Counselling and IHBI, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- QIMR Berghofer Institute, Brisbane, Australia
| | - Michael Breakspear
- QIMR Berghofer Institute, Brisbane, Australia
- Metro North Mental Health Service, Brisbane, Australia
| | - Neil Vasdev
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Paul Thomas
- Herston Imaging Research Facility, Faculty of Medicine, University of Queensland Centre for Clinical Research, Herston, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
- National Imaging Facility, Brain and Mind Centre and Faculty of Health Sciences, University of Sydney, Camperdown, Australia
| | - Richard Banati
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
- National Imaging Facility, Brain and Mind Centre and Faculty of Health Sciences, University of Sydney, Camperdown, Australia
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31
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Niccolini F, Pagano G, Fusar-Poli P, Wood A, Mrzljak L, Sampaio C, Politis M. Striatal molecular alterations in HD gene carriers: a systematic review and meta-analysis of PET studies. J Neurol Neurosurg Psychiatry 2018; 89:185-196. [PMID: 28889093 DOI: 10.1136/jnnp-2017-316633] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/31/2017] [Accepted: 08/23/2017] [Indexed: 11/03/2022]
Abstract
BACKGROUND Over the past years, positron emission tomography (PET) imaging studies have investigated striatal molecular changes in premanifest and manifest Huntington's disease (HD) gene expansion carriers (HDGECs), but they have yielded inconsistent results. OBJECTIVE To systematically examine the evidence of striatal molecular alterations in manifest and premanifest HDGECs as measured by PET imaging studies. METHODS MEDLINE, ISI Web of Science, Cochrane Library and Scopus databases were searched for articles published until 7 June 2017 that included PET studies in manifest and premanifest HDGECs. Meta-analyses were conducted with random effect models, and heterogeneity was addressed with I2 index, controlling for publication bias and quality of study. The primary outcome was the standardised mean difference (SMD) of PET uptakes in the whole striatum, caudate and putamen in manifest and premanifest HDGECs compared with healthy controls (HCs). RESULTS Twenty-four out of 63 PET studies in premanifest (n=158) and manifest (n=191) HDGECs and HCs (n=333) were included in the meta-analysis. Premanifest and manifest HDGECs showed significant decreases in dopamine D2 receptors in caudate (SMD=-1.233, 95% CI -1.753 to -0.713, p<0.0001; SMD=-5.792, 95% CI -7.695 to -3.890, p<0.0001) and putamen (SMD=-1.479, 95% CI -1.965 to -0.992, p<0.0001; SMD=-5.053, 95% CI -6.558 to -3.549, p<0.0001), in glucose metabolism in caudate (SMD=-0.758, 95% CI -1.139 to -0.376, p<0.0001; SMD=-3.738, 95% CI -4.880 to -2.597, p<0.0001) and putamen (SMD=-2.462, 95% CI -4.208 to -0.717, p=0.006; SMD=-1.650, 95% CI -2.842 to -0.458, p<0.001) and in striatal PDE10A binding (SMD=-1.663, 95% CI -2.603 to -0.723, p=0.001; SMD=-2.445, 95% CI -3.371 to -1.519, p<0.001). CONCLUSIONS PET imaging has the potential to detect striatal molecular changes even at the early premanifest stage of HD, which are relevant to the neuropathological mechanisms underlying the development of the disease.
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Affiliation(s)
- Flavia Niccolini
- Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Gennaro Pagano
- Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Andrew Wood
- CHDI Management/CHDI Foundation, Princeton, New Jersey, USA
| | | | | | - Marios Politis
- Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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32
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Ottoy J, De Picker L, Verhaeghe J, Deleye S, Wyffels L, Kosten L, Sabbe B, Coppens V, Timmers M, van Nueten L, Ceyssens S, Stroobants S, Morrens M, Staelens S. 18F-PBR111 PET Imaging in Healthy Controls and Schizophrenia: Test-Retest Reproducibility and Quantification of Neuroinflammation. J Nucl Med 2018; 59:1267-1274. [PMID: 29326362 DOI: 10.2967/jnumed.117.203315] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/13/2017] [Indexed: 01/03/2023] Open
Abstract
Activated microglia express the translocator protein (TSPO) on the outer mitochondrial membrane. 18F-PBR111 is a second-generation PET ligand that specifically binds the TSPO, allowing in vivo visualization and quantification of neuroinflammation. The aim of this study was to evaluate whether the test-retest variability of 18F-PBR111 in healthy controls is acceptable to detect a psychosis-associated neuroinflammatory signal in schizophrenia. Methods: Dynamic 90-min 18F-PBR111 scans were obtained in 17 healthy male controls (HCs) and 11 male schizophrenia patients (SPs) during a psychotic episode. Prior genotyping for the rs6917 polymorphism distinguished high-affinity binders (HABs) and mixed-affinity binders (MABs). Total volume of distribution (VT) was determined from 2-tissue-compartment modeling with vascular trapping and a metabolite-corrected plasma input function. A subgroup of HCs (n = 12; 4 HABs and 8 MABs) was scanned twice to assess absolute test-retest variability and intraclass correlation coefficients of the regional VT values. Differences in TSPO binding between HC and SP were assessed using mixed model analysis adjusting for age, genotype, and age*cohort. The effect of using different scan durations (VT-60 min versus VT-90 min) was determined based on Pearson r. Data were mean ± SD. Results: Mean absolute variability in VT ranged from 16% ± 14% (19% ± 20% HAB; 15% ± 11% MAB) in the cortical gray matter to 22% ± 15% (23% ± 15% HAB; 22% ± 16% MAB) in the hippocampus. Intraclass correlation coefficients were consistently between 0.64 and 0.82 for all tested regions. TSPO binding in SP compared with HC depended on age (cohort*age: P < 0.05) and was increased by +14% ± 4% over the regions. There was a significant effect of genotype on TSPO binding, and VT of HABs was 31% ± 8% (HC: 17% ± 5%, SP: 61% ± 14%) higher than MABs. Across all clinical groups, VT-60 min and VT-90 min were strongly correlated (r > 0.7, P < 0.0001). Conclusion:18F-PBR111 can be used for monitoring of TSPO binding, as shown by medium test-retest variability and reliability of VT in HCs. Microglial activation is present in SPs depending on age and needs to be adjusted for genotype.
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Affiliation(s)
- Julie Ottoy
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Livia De Picker
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Duffel, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Steven Deleye
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Leonie Wyffels
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Lauren Kosten
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Bernard Sabbe
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Duffel, Belgium
| | - Violette Coppens
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Duffel, Belgium
| | - Maarten Timmers
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium; and.,Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Luc van Nueten
- Janssen Research and Development, Janssen Pharmaceutica N.V., Beerse, Belgium; and
| | - Sarah Ceyssens
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Manuel Morrens
- Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.,University Department of Psychiatry, Campus Duffel, Duffel, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
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Arakawa R, Stenkrona P, Takano A, Nag S, Maior RS, Halldin C. Test-retest reproducibility of [ 11C]-L-deprenyl-D 2 binding to MAO-B in the human brain. EJNMMI Res 2017. [PMID: 28634836 PMCID: PMC5478550 DOI: 10.1186/s13550-017-0301-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Background [11C]-l-deprenyl-D2 is a positron emission tomography (PET) radioligand for measurement of the monoamine oxidase B (MAO-B) activity in vivo brain. The estimation of the test-retest reproducibility is important for accurate interpretation of PET studies. Results We performed two [11C]-l-deprenyl-D2 scans for six healthy subjects and evaluated the test-retest variability of this radioligand. MAO-B binding was quantified by two tissue compartment model (2TCM) with three rate constants (K1, k2, k3) using metabolite-corrected plasma radioactivity. The λk3 defined as (K1/k2) × k3 was also calculated. The correlation between MAO-B binding and age, and the effect of partial volume effect correction (PVEc) for the reproducibility were also estimated. %difference of k3 was 2.6% (medial frontal cortex) to 10.3% (hippocampus), and that of λk3 was 5.0% (thalamus) to 9.2% (cerebellum). Mean %difference of all regions were 5.3 and 7.0% in k3 and λk3, respectively. All regions showed below 10% variabilities except the hippocampus in k3 (10.3%). Intraclass correlation coefficient (ICC) of k3 was 0.78 (hippocampus) to 0.98 (medial frontal cortex), and that of λk3 was 0.78 (hippocampus) to 0.95 (thalamus). Mean ICC were 0.94 and 0.89 in k3 and λk3, respectively. The highest positive correlation with age was observed in the hippocampus, as r = 0.75 in k3 and 0.76 in λk3. After PVEc, mean %difference were 5.6 and 7.2% in k3 and λk3, respectively. Mean ICC were 0.92 and 0.90 for k3 and λk3, respectively. These values were almost the same as those before PVEc. Conclusions The present results indicate that k3 and λk3 of [11C]-l-deprenyl-D2 are reliable parameters for test-retest reproducibility with healthy subjects both before and after PVEc. The studies with patients of larger sample size are required for further clinical applications.
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Affiliation(s)
- Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.
| | - Per Stenkrona
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Akihiro Takano
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
| | - Rafael S Maior
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden.,Primate Center and Laboratory of Neurosciences and Behavior, Department of Physiological Sciences, Institute of Biology, University of Brasilia, Brasilia, Brazil
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, Sweden
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Reduction of PK11195 uptake observed in multiple sclerosis lesions after natalizumab initiation. Mult Scler Relat Disord 2017. [PMID: 28641769 DOI: 10.1016/j.msard.2017.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The objective of this study is to longitudinally analyze the uptake of [11C]PK11195-PET in multiple sclerosis patients after 3 and 6 months of natalizumab treatment. METHODS Eighteen MS patients, starting treatment with monocloncal anti-VLA-4, were enrolled in a longitudinal PK-PET study. PK uptake was quantified by volume of distribution (VT) calculation using image-derived input function at baseline, 3 and 6 months. Pharmacokinetic quantification was done using a segmented MRI, and selected areas included white matter, gadolinium enhancing lesions, non-enhancing lesions, cortical grey matter and thalamus. VTs of lesions were calculated in reference to each patient's white matter (VT ratio=VTr), to consider physiologic variability. RESULTS Test-retest variability was stable for healthy control (HC). Quantification of PK uptake was completed in 18 patients, and baseline uptake was compared to 6-month uptake. After the start of natalizumab VTr significantly decreased in 13 individual enhancing lesions present within 5 patients (p=0.001). Moreover, VTr of the sum of non-enhancing lesions showed a moderate decrease (p=0.03). No longitudinal changes were detected in normal appearing white matter, the thalamus and cortical grey matter. CONCLUSION A reduction in PK11195 uptake was observed in both enhancing and chronic lesions after the start of natalizumab. PK11195 PET can be used as tool to assess the longitudinal change in MS lesions.
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Politis M, Pagano G, Niccolini F. Imaging in Parkinson's Disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2017; 132:233-274. [DOI: 10.1016/bs.irn.2017.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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36
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Feng L, Jensen P, Thomsen G, Dyssegaard A, Svarer C, Knudsen LV, Møller K, Thomsen C, Mikkelsen JD, Guilloteau D, Knudsen GM, Pinborg LH. The Variability of Translocator Protein Signal in Brain and Blood of Genotyped Healthy Humans Using In Vivo 123I-CLINDE SPECT Imaging: A Test–Retest Study. J Nucl Med 2016; 58:989-995. [DOI: 10.2967/jnumed.116.183202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 10/21/2016] [Indexed: 11/16/2022] Open
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A systematic review of lessons learned from PET molecular imaging research in atypical parkinsonism. Eur J Nucl Med Mol Imaging 2016; 43:2244-2254. [PMID: 27470326 PMCID: PMC5047923 DOI: 10.1007/s00259-016-3464-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 07/11/2016] [Indexed: 12/27/2022]
Abstract
PURPOSE To systematically review the previous studies and current status of positron emission tomography (PET) molecular imaging research in atypical parkinsonism. METHODS MEDLINE, ISI Web of Science, Cochrane Library, and Scopus electronic databases were searched for articles published until 29th March 2016 and included brain PET studies in progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal syndrome (CBS). Only articles published in English and in peer-reviewed journals were included in this review. Case-reports, reviews, and non-human studies were excluded. RESULTS Seventy-seven PET studies investigating the dopaminergic system, glucose metabolism, microglial activation, hyperphosphorilated tau, opioid receptors, the cholinergic system, and GABAA receptors in PSP, MSA, and CBS patients were included in this review. Disease-specific patterns of reduced glucose metabolism have shown higher accuracy than dopaminergic imaging techniques to distinguish between parkinsonian syndromes. Microglial activation has been found in all forms of atypical parkinsonism and reflects the known distribution of neuropathologic changes in these disorders. Opioid receptors are decreased in the striatum of PSP and MSA patients. Subcortical cholinergic dysfunction was more severe in MSA and PSP than Parkinson's disease patients although no significant changes in cortical cholinergic receptors were seen in PSP with cognitive impairment. GABAA receptors were decreased in metabolically affected cortical and subcortical regions in PSP patients. CONCLUSIONS PET molecular imaging has provided valuable insight for understanding the mechanisms underlying atypical parkinsonism. Changes at a molecular level occur early in the course of these neurodegenerative diseases and PET imaging provides the means to aid differential diagnosis, monitor disease progression, identify of novel targets for pharmacotherapy, and monitor response to new treatments.
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Feeney C, Scott G, Raffel J, Roberts S, Coello C, Jolly A, Searle G, Goldstone AP, Brooks DJ, Nicholas RS, Trigg W, Gunn RN, Sharp DJ. Kinetic analysis of the translocator protein positron emission tomography ligand [ 18F]GE-180 in the human brain. Eur J Nucl Med Mol Imaging 2016; 43:2201-2210. [PMID: 27349244 PMCID: PMC5047949 DOI: 10.1007/s00259-016-3444-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/14/2016] [Indexed: 02/04/2023]
Abstract
Purpose PET can image neuroinflammation by targeting the translocator protein (TSPO), which is upregulated in activated microglia. The high nonspecific binding of the first-generation TSPO radioligand [11C]PK-11195 limits accurate quantification. [18F]GE-180, a novel TSPO ligand, displays superior binding to [11C]PK-11195 in vitro. Our objectives were to: (1) evaluate tracer characteristics of [18F]GE-180 in the brains of healthy human subjects; and (2) investigate whether the TSPO Ala147Thr polymorphism influences outcome measures. Methods Ten volunteers (five high-affinity binders, HABs, and five mixed-affinity binders, MABs) underwent a dynamic PET scan with arterial sampling after injection of [18F]GE-180. Kinetic modelling of time–activity curves with one-tissue and two-tissue compartment models and Logan graphical analysis was applied to the data. The primary outcome measure was the total volume of distribution (VT) across various regions of interest (ROIs). Secondary outcome measures were the standardized uptake values (SUV), the distribution volume and SUV ratios estimated using a pseudoreference region. Results The two-tissue compartment model was the best model. The average regional delivery rate constant (K1) was 0.01 mL cm−3 min−1 indicating low extraction across the blood–brain barrier (1 %). The estimated median VT across all ROIs was also low, ranging from 0.16 mL cm−3 in the striatum to 0.38 mL cm−3 in the thalamus. There were no significant differences in VT between HABs and MABs across all ROIs. Conclusion A reversible two-tissue compartment model fitted the data well and determined that the tracer has a low first-pass extraction (approximately 1 %) and low VT estimates in healthy individuals. There was no observable dependency on the rs6971 polymorphism as compared to other second-generation TSPO PET tracers. Investigation of [18F]GE-180 in populations with neuroinflammatory disease is needed to determine its suitability for quantitative assessment of TSPO expression. Electronic supplementary material The online version of this article (doi:10.1007/s00259-016-3444-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claire Feeney
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK. .,Computational, Cognitive and Clinical Neuroimaging Laboratory, Hammersmith Hospital, 3rd Floor, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Gregory Scott
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - Joel Raffel
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - S Roberts
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - Christopher Coello
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - Amy Jolly
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - Graham Searle
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - A P Goldstone
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - David J Brooks
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Richard S Nicholas
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | | | - Roger N Gunn
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - David J Sharp
- Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK
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Toyohara J, Sakata M, Hatano K, Yanai S, Endo S, Ishibashi K, Wagatsuma K, Ishii K, Ishiwata K. Preclinical and first-in-man studies of [(11)C]CB184 for imaging the 18-kDa translocator protein by positron emission tomography. Ann Nucl Med 2016; 30:534-43. [PMID: 27329083 DOI: 10.1007/s12149-016-1094-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/30/2016] [Indexed: 01/17/2023]
Abstract
OBJECTIVE We performed preclinical and first-in-man clinical positron emission tomography (PET) studies in human brain using N,N-di-n-propyl-2-[2-(4-[(11)C]methoxyphenyl)-6,8-dichloroimidazol[1,2-a]pyridine-3-yl]acetamide ([(11)C]CB184) to image the 18-kDa translocator protein (TSPO), which is overexpressed in activated microglia in neuroinflammatory conditions. METHODS In vitro selectivity of CB184 was characterized. The radiation absorbed dose by [(11)C]CB184 in humans was calculated from murine distribution data. Acute toxicity of CB184 hydrochloride in rats at a dose of 5.81 mg/kg body weight, which is >10,000-fold higher than the clinical equivalent dose of [(11)C]CB184, was evaluated. Acute toxicity of [(11)C]CB184 injection of a 400-fold dose to administer a postulated dose of 740 MBq [(11)C]CB184 was also evaluated after the decay-out of (11)C. The mutagenicity of CB184 was studied with a reverse mutation test (Ames test). The pharmacological effect of CB184 injection in mice was studied with an open field test. The first PET imaging of TSPO with [(11)C]CB184 in a normal human volunteer was performed. RESULTS A suitable preparation method for [(11)C]CB184 injection was established. CB184 showed low activity in a 28-standard receptor binding profile. The radiation absorbed dose by [(11)C]CB184 in humans was sufficiently low for clinical use, and no acute toxicity of CB184 or [(11)C]CB184 injection was found. No mutagenicity or apparent effect on locomotor activity or anxiety status was observed for CB184. We safely performed brain imaging with PET following administration of [(11)C]CB184 in a normal human volunteer. A 90-min dynamic scan showed rapid initial uptake of radioactivity in the brain followed by prompt clearance. [(11)C]CB184 was homogeneously distributed in the gray matter. The total distribution volume of [(11)C]CB184 was highest in the thalamus followed by the cerebellar cortex and elsewhere. Although regional differences were small, the observed [(11)C]CB184 binding pattern was consistent with the TSPO distribution in normal human brain. Peripherally, [(11)C]CB184 was metabolized in humans: 30 % of the radioactivity in plasma was detected as the unchanged form after 60 min. CONCLUSIONS [(11)C]CB184 is suitable for imaging TSPO in human brain and provides an acceptable radiation dose. Pharmacological safety was noted at the dose required for PET imaging.
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Affiliation(s)
- Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Muneyuki Sakata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kentaro Hatano
- Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Shuichi Yanai
- Research Team for Aging Neuroscience, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Shogo Endo
- Research Team for Aging Neuroscience, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Kenji Ishibashi
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kei Wagatsuma
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kenji Ishii
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kiichi Ishiwata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.,Institute of Cyclotron and Drug Discovery Research, Southern Tohoku Research Institute for Neuroscience, Koriyama, Japan.,Department of Biofunctional Imaging, Fukushima Medical University, Fukushima, Japan
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Femminella GD, Ninan S, Atkinson R, Fan Z, Brooks DJ, Edison P. Does Microglial Activation Influence Hippocampal Volume and Neuronal Function in Alzheimer’s Disease and Parkinson’s Disease Dementia? J Alzheimers Dis 2016; 51:1275-89. [DOI: 10.3233/jad-150827] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
| | | | | | - Zhen Fan
- Neurology Imaging Unit, Imperial College London, London, UK
| | - David J. Brooks
- Neurology Imaging Unit, Imperial College London, London, UK
- Department of Nuclear Medicine, Aarhus University, Denmark
| | - Paul Edison
- Neurology Imaging Unit, Imperial College London, London, UK
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Vera JH, Guo Q, Cole JH, Boasso A, Greathead L, Kelleher P, Rabiner EA, Kalk N, Bishop C, Gunn RN, Matthews PM, Winston A. Neuroinflammation in treated HIV-positive individuals: A TSPO PET study. Neurology 2016; 86:1425-1432. [PMID: 26911637 DOI: 10.1212/wnl.0000000000002485] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 01/06/2015] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE To explore the effects of microglial activation on brain function and structure, and its relationship with peripheral inflammatory markers, in treated, HIV-positive individuals, using in vivo [(11)C]PBR28 PET (to measure the 18 kDa translocator protein [TSPO]). METHODS Cognitively healthy HIV-positive individuals on suppressive antiretroviral therapy and HIV-negative individuals (controls) underwent brain [(11)C]PBR28 PET and MRI. HIV-positive patients completed neuropsychological testing and CSF testing for chemokines. The concentration of bacterial ribosomal 16sDNA in plasma was measured as a marker of microbial translocation. RESULTS HIV-positive individuals showed global increases in TSPO expression compared to controls (corrected p < 0.01), with significant regional increases in the parietal (p = 0.001) and occipital (p = 0.046) lobes and in the globus pallidus (p = 0.035). TSPO binding in the hippocampus, amygdala, and thalamus were associated with poorer global cognitive performance in tasks assessing verbal and visual memory (p < 0.05). Increased TSPO binding was associated with increased brain white matter diffusion MRI mean diffusivity in HIV-positive individuals, a lower CD4/CD8 ratio, and both high pretreatment HIV RNA and plasma concentration ribosomal 16s DNA (p < 0.05). CONCLUSIONS Cognitively healthy HIV-positive individuals show evidence for a chronically activated brain innate immune response and elevated blood markers of microbial translocation despite effective control of plasma viremia. Increased brain inflammation is associated with poorer cognitive performance and white matter microstructural pathology, suggesting a possible role in cognitive impairments found in some HIV-positive patients despite effective treatment.
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Affiliation(s)
- Jaime H Vera
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK.
| | - Qi Guo
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - James H Cole
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Adriano Boasso
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Louise Greathead
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Peter Kelleher
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Eugenii A Rabiner
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Nicola Kalk
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Courtney Bishop
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Roger N Gunn
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Paul M Matthews
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
| | - Alan Winston
- From the Division of Medicine, Section of Infectious Diseases (J.H.V., A.W.), Division of Brain Sciences (J.H.C., R.N.G., P.M.M.), and Centre for Immunology and Vaccinology (A.B., L.G., P.K.), Imperial College London; Division of Medicine (J.H.V.), Brighton and Sussex Medical School; Imanova Centre for Imaging Sciences (Q.G., E.A.R., N.K., C.B., R.N.G.), London; and Chelsea and Westminster Hospital (A.B., L.G., P.K.), London, UK
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Tonietto M, Rizzo G, Veronese M, Fujita M, Zoghbi SS, Zanotti-Fregonara P, Bertoldo A. Plasma radiometabolite correction in dynamic PET studies: Insights on the available modeling approaches. J Cereb Blood Flow Metab 2016; 36:326-39. [PMID: 26661202 PMCID: PMC4759680 DOI: 10.1177/0271678x15610585] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 07/09/2015] [Indexed: 11/17/2022]
Abstract
Full kinetic modeling of dynamic PET images requires the measurement of radioligand concentrations in the arterial plasma. The unchanged parent radioligand must, however, be separated from its radiometabolites by chromatographic methods. Thus, only few samples can usually be analyzed and the resulting measurements are often noisy. Therefore, the measurements must be fitted with a mathematical model. This work presents a comprehensive analysis of the different models proposed in the literature to describe the plasma parent fraction (PPf) and of the alternative approaches for radiometabolite correction. Finally, we used a dataset of [(11)C]PBR28 brain PET data as a case study to guide the reader through the PPf model selection process.
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Affiliation(s)
- Matteo Tonietto
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Gaia Rizzo
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Mattia Veronese
- Department of Neuroimaging, IoPPN, King's College London, London, UK
| | - Masahiro Fujita
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA INCIA UMR-CNRS 5287, Université de Bordeaux, Bordeaux, France
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van der Doef TF, Doorduin J, van Berckel BNM, Cervenka S. Assessing brain immune activation in psychiatric disorders: clinical and preclinical PET imaging studies of the 18-kDa translocator protein. Clin Transl Imaging 2015; 3:449-460. [PMID: 28781965 PMCID: PMC5496979 DOI: 10.1007/s40336-015-0140-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 08/26/2015] [Indexed: 01/24/2023]
Abstract
Accumulating evidence from different lines of research suggests an involvement of the immune system in the pathophysiology of several psychiatric disorders. During recent years, a series of positron emission tomography (PET) studies have been published using radioligands for the translocator protein (TSPO) to study microglia activation in schizophrenia, bipolar I disorder, major depression, autism spectrum disorder, and drug abuse. The results have been somewhat conflicting, which could be due to differences both in patient sample characteristics and in PET methods. In particular, further work is needed to address both methodological and biological sources of variability in TSPO levels, a process in which the use of animal models and small animal PET systems can be a valuable tool. Given this development, PET studies of immune activation have the potential to further increase our understanding of disease mechanisms in psychiatric disorders, which is a requisite in the search for new treatment approaches. Furthermore, molecular imaging could become an important clinical tool for identifying specific subgroups of patients or disease stages that would benefit from treatment targeting the immune system.
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Affiliation(s)
- Thalia F van der Doef
- Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bart N M van Berckel
- Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Simon Cervenka
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
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Collste K, Forsberg A, Varrone A, Amini N, Aeinehband S, Yakushev I, Halldin C, Farde L, Cervenka S. Test-retest reproducibility of [(11)C]PBR28 binding to TSPO in healthy control subjects. Eur J Nucl Med Mol Imaging 2015; 43:173-183. [PMID: 26293827 DOI: 10.1007/s00259-015-3149-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 07/20/2015] [Indexed: 11/30/2022]
Abstract
PURPOSE The PET radioligand [(11)C]PBR28 binds to the translocator protein (TSPO), a marker of brain immune activation. We examined the reproducibility of [(11)C]PBR28 binding in healthy subjects with quantification on a regional and voxel-by-voxel basis. In addition, we performed a preliminary analysis of diurnal changes in TSPO availability. METHODS Twelve subjects were examined using a high-resolution research tomograph and [(11)C]PBR28, six in the morning and afternoon of the same day, and six in the morning on two separate days. Regional volumes of distribution (V T) were derived using a region-of-interest based two-tissue compartmental analysis (2TCM), as well as a parametric approach. Metabolite-corrected arterial plasma was used as input function. RESULTS For the whole sample, the mean absolute variability in V T in the grey matter (GM) was 18.3 ± 12.7 %. Intraclass correlation coefficients in GM regions ranged from 0.90 to 0.94. Reducing the time of analysis from 91 to 63 min yielded a variability of 16.9 ± 14.9 %. There was a strong correlation between the parametric and 2TCM-derived GM values (r = 0.99). A significant increase in GM V T was observed between the morning and afternoon examinations when using secondary methods of quantification (p = 0.028). In the subjects examined at the same time of the day, the absolute variability was 15.9 ± 12.2 % for the 91-min 2TCM data. CONCLUSION V T of [(11)C]PBR28 binding showed medium reproducibility and high reliability in GM regions. Our findings support the use of parametric approaches for determining [(11)C]PBR28 V T values, and indicate that the acquisition time could be shortened. Diurnal changes in TSPO binding in the brain may be a potential confounder in clinical studies and should be investigated further.
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Affiliation(s)
- K Collste
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden.
| | - A Forsberg
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - A Varrone
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - N Amini
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - S Aeinehband
- Department of Clinical Neuroscience, Neuroimmunology Unit, Karolinska Institutet, Stockholm, Sweden
| | - I Yakushev
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden.,Department of Nuclear Medicine and TUM Neuroimaging Center (TUM-NIC), Technische Universität München, Munich, Germany
| | - C Halldin
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - L Farde
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - S Cervenka
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
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Park E, Gallezot JD, Delgadillo A, Liu S, Planeta B, Lin SF, O'Connor KC, Lim K, Lee JY, Chastre A, Chen MK, Seneca N, Leppert D, Huang Y, Carson RE, Pelletier D. (11)C-PBR28 imaging in multiple sclerosis patients and healthy controls: test-retest reproducibility and focal visualization of active white matter areas. Eur J Nucl Med Mol Imaging 2015; 42:1081-92. [PMID: 25833352 DOI: 10.1007/s00259-015-3043-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/08/2015] [Indexed: 11/28/2022]
Abstract
PURPOSE Activated microglia play a key role in inflammatory demyelinating injury in multiple sclerosis (MS). Microglial activation can be measured in vivo using a positron emission tomography (PET) ligand (11)C-PBR28. We evaluated the test-retest variability (TRV) and lesion detectability of (11)C-PBR28 binding in MS subjects and healthy controls (HCs) with high-resolution PET. METHODS Four clinically and radiologically stable relapsing-remitting MS subjects (age 41 ± 7 years, two men/two women) and four HCs (age 42 ± 8 years, 2 two men/two women), matched for translocator protein genotype [two high- and two medium-affinity binders according to DNA polymorphism (rs6971) in each group], were studied for TRV. Another MS subject (age 41 years, male) with clinical and radiological activity was studied for lesion detectability. Dynamic data were acquired over 120 min after injection of 634 ± 101 MBq (11)C-PBR28. For the TRV study, subjects were scanned twice, on average 1.4 weeks apart. Volume of distribution (V T) derived from multilinear analysis (MA1) modeling (t* = 30 min, using arterial input data) was the main outcome measure. RESULTS Mean test V T values (ml cm(-3)) were 3.9 ± 1.4 in the whole brain gray matter (GM), 3.6 ± 1.2 in the whole brain white matter (WM) or normal-appearing white matter (NAWM), and 3.3 ± 0.6 in MS WM lesions; mean retest V T values were 3.7 ± 1.0 in GM, 3.3 ± 0.9 in WM/NAWM, and 3.3 ± 0.7 in MS lesions. Test-retest results showed a mean absolute TRV ranging from 7 to 9 % across GM, WM/NAWM, and MS lesions. High-affinity binders demonstrated 30 % higher V T than medium-affinity binders in GM. Focal (11)C-PBR28 uptake was detected in two enhancing lesions of the active MS patient. CONCLUSION High-resolution (11)C-PBR28 PET can visualize focal areas where microglial activation is known to be present and has good test-retest reproducibility in the human brain. (11)C-PBR28 PET is likely to be valuable for monitoring both MS disease evolution and response to therapeutic strategies that target microglial activation.
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Affiliation(s)
- Eunkyung Park
- PET Center, Department of Diagnostic Radiology, Yale School of Medicine, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520-8048, USA,
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Lyoo CH, Ikawa M, Liow JS, Zoghbi SS, Morse CL, Pike VW, Fujita M, Innis RB, Kreisl WC. Cerebellum Can Serve As a Pseudo-Reference Region in Alzheimer Disease to Detect Neuroinflammation Measured with PET Radioligand Binding to Translocator Protein. J Nucl Med 2015; 56:701-6. [PMID: 25766898 DOI: 10.2967/jnumed.114.146027] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/03/2015] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Alzheimer disease (AD) is associated with an increase in the brain of the 18-kDa translocator protein (TSPO), which is overexpressed in activated microglia and reactive astrocytes. Measuring the density of TSPO with PET typically requires absolute quantitation with arterial blood sampling, because a reference region devoid of TSPO does not exist in the brain. We sought to determine whether a simple ratio method could substitute for absolute quantitation of binding with (11)C-PBR28, a second-generation radioligand for TSPO. METHODS (11)C-PBR28 PET imaging was performed in 21 healthy controls, 11 individuals with mild cognitive impairment, and 25 AD patients. Group differences in (11)C-PBR28 binding were compared using 2 methods. The first was the gold standard method of calculating total distribution volume (V(T)), using the 2-tissue-compartment model with the arterial input function, corrected for plasma-free fraction of radiotracer (f(P)). The second method used a ratio of brain uptake in target regions to that in cerebellum-that is, standardized uptake value ratio (SUVR). RESULTS Using absolute quantitation, we confirmed that TSPO binding (V(T)/f(P)) was greater in AD patients than in healthy controls in expected temporoparietal regions and was not significantly different among the 3 groups in the cerebellum. When the cerebellum was used as a pseudo-reference region, the SUVR method detected greater binding in AD patients than controls in the same regions as absolute quantification and in 1 additional region, suggesting SUVR may have greater sensitivity. Coefficients of variation of SUVR measurements were about two-thirds lower than those of absolute quantification, and the resulting statistical significance was much higher for SUVR when comparing AD and healthy controls (e.g., P < 0.0005 for SUVR vs. P = 0.023 for VT/fP in combined middle and inferior temporal cortex). CONCLUSION To measure TSPO density in AD patients and control subjects, a simple ratio method SUVR can substitute for, and may even be more sensitive than, absolute quantitation. The SUVR method is expected to improve subject tolerability by allowing shorter scanning time and not requiring arterial catheterization. In addition, this ratio method allows smaller sample sizes for comparable statistical significance because of the relatively low variability of the ratio values.
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Affiliation(s)
- Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Masamichi Ikawa
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Masahiro Fujita
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - William Charles Kreisl
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, New York
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In vivo analysis of neuroinflammation in the late chronic phase after experimental stroke. Neuroscience 2015; 292:71-80. [PMID: 25701708 DOI: 10.1016/j.neuroscience.2015.02.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE In vivo imaging of inflammatory processes is a valuable tool in stroke research. We here investigated the combination of two imaging modalities in the chronic phase after cerebral ischemia: magnetic resonance imaging (MRI) using intravenously applied ultra small supraparamagnetic iron oxide particles (USPIO), and positron emission tomography (PET) with the tracer [(11)C]PK11195. METHODS Rats were subjected to permanent middle cerebral artery occlusion (pMCAO) by the macrosphere model and monitored by MRI and PET for 28 or 56 days, followed by immunohistochemical endpoint analysis. To our knowledge, this is the first study providing USPIO-MRI data in the chronic phase up to 8 weeks after stroke. RESULTS Phagocytes with internalized USPIOs induced MRI-T2(∗) signal alterations in the brain. Combined analysis with [(11)C]PK11195-PET allowed quantification of phagocytic activity and other neuroinflammatory processes. From 4 weeks after induction of ischemia, inflammation was dominated by phagocytes. Immunohistochemistry revealed colocalization of Iba1+ microglia with [(11)C]PK11195 and ED1/CD68 with USPIOs. USPIO-related iron was distinguished from alternatively deposited iron by assessing MRI before and after USPIO application. Tissue affected by non-phagocytic inflammation during the first week mostly remained in a viably vital but remodeled state after 4 or 8 weeks, while phagocytic activity was associated with severe injury and necrosis accordingly. CONCLUSIONS We conclude that the combined approach of USPIO-MRI and [(11)C]PK11195-PET allows to observe post-stroke inflammatory processes in the living animal in an intraindividual and longitudinal fashion, predicting long-term tissue fate. The non-invasive imaging methods do not affect the immune system and have been applied to human subjects before. Translation into clinical applications is therefore feasible.
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Alfonso Romero-Sandoval E, Sweitzer S. Nonneuronal central mechanisms of pain: glia and immune response. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 131:325-58. [PMID: 25744678 DOI: 10.1016/bs.pmbts.2014.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The role of central glial cells in the mechanisms underlying pain has been intensively studied in the last two decades. Most studies on glia and pain focused on the potential detrimental role of glial cells following noxious stimulus/insults manifested as an "activation" or a "reactive" state (increase in glial marker expression and production of proinflammatory/nociceptive molecules). Therefore, "activated" or "reactive" glial cells became a target for the future generation of drugs to treat chronic pain. Several glial modulators that reduce the activation of glial cells have shown great efficacy in multiple animal (rodents mostly) models of pain (acute, subacute, chronic, inflammatory, neuropathic, surgical, etc.). These encouraging findings inspired clinical trials that have been completed in the last 5 years. Unfortunately, all clinical trials with these glial modulators have failed to demonstrate efficacy for the treatment of pain. New lines of investigation and elegant experimental designs are shedding light on alternative glial functions, which demonstrate that "glial reactivity" is not necessarily deleterious in some pathological conditions. New strategies to validate findings through our current animal models are necessary to enhance the translational value of our preclinical studies. Also, more studies using human subjects would enhance our understanding of glial cells in the context of pain. This chapter explores the available literature to objectively ponder the potential role of glial cells in human pain conditions.
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Affiliation(s)
- E Alfonso Romero-Sandoval
- Department of Pharmaceutical and Administrative Sciences, Presbyterian College School of Pharmacy, Clinton, South Carolina, USA.
| | - Sarah Sweitzer
- Department of Pharmaceutical and Administrative Sciences, Presbyterian College School of Pharmacy, Clinton, South Carolina, USA
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