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Victorio CBL, Ganasarajah A, Novera W, Ong J, Msallam R, Chacko AM. Translocator protein (TSPO) is a biomarker of Zika virus (ZIKV) infection-associated neuroinflammation. Emerg Microbes Infect 2024; 13:2348528. [PMID: 38662785 PMCID: PMC11132733 DOI: 10.1080/22221751.2024.2348528] [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: 01/31/2024] [Accepted: 04/23/2024] [Indexed: 05/29/2024]
Abstract
Zika is a systemic inflammatory disease caused by infection with Zika virus (ZIKV). ZIKV infection in adults is associated with encephalitis marked by elevated expression of pro-inflammatory cytokines and chemokines, as well as increased brain infiltration of immune cells. In this study, we demonstrate that ZIKV encephalitis in a mouse infection model exhibits increased brain TSPO expression. TSPO expression on brain-resident and infiltrating immune cells in ZIKV infection correlates with disease and inflammation status in the brain. Brain TSPO expression can also be sensitively detected ex vivo and in vitro using radioactive small molecule probes that specifically bind to TSPO, such as [3H]PK11195. TSPO expression on brain-resident and infiltrating immune cells is a biomarker of ZIKV neuroinflammation, which can also be a general biomarker of acute viral neuroinflammatory disease.
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Affiliation(s)
- Carla Bianca Luena Victorio
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Arun Ganasarajah
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Wisna Novera
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Joanne Ong
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Rasha Msallam
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Ann-Marie Chacko
- Laboratory for Translational and Molecular Imaging (LTMI), Cancer and Stem Cell Biology Programme, Duke-NUS Medical School, Singapore, Singapore
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Ford J, Ortalli S, Gouverneur V. The 18F-Difluoromethyl Group: Challenges, Impact and Outlook. Angew Chem Int Ed Engl 2024:e202404957. [PMID: 38640422 DOI: 10.1002/anie.202404957] [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: 03/12/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 04/21/2024]
Abstract
The difluoromethyl functionality has proven useful in drug discovery, as it can modulate the properties of bioactive molecules. For PET imaging, this structural motif has been largely underexploited in (pre)clinical radiotracers due to a lack of user-friendly radiosynthetic routes. This Minireview provides an overview of the challenges facing radiochemists and summarises the efforts made to date to access 18F-difluoromethyl-containing radiotracers. Two distinct approaches have prevailed, the first of which relies on 18F-fluorination. A second approach consists of a 18F-difluoromethylation process, which uses 18F-labelled reagents capable of releasing key reactive intermediates such as the [18F]CF2H radical or [18F]difluorocarbene. Finally, we provide an outlook for future directions in the radiosynthesis of [18F]CF2H compounds and their application in tracer radiosynthesis.
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Affiliation(s)
- Joseph Ford
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Sebastiano Ortalli
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
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Casalechi M, Dela Cruz C, Assis WA, Vieira-Lopes M, Lopes FEF, Francisco AMC, Reis FM. Translocator protein expression and localization in human endometrium and endometriosis: A potential target for a noninvasive diagnosis? Cell Biol Int 2024. [PMID: 38511230 DOI: 10.1002/cbin.12157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/15/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024]
Abstract
The limitations of current imaging methods to detect small or superficial endometriotic lesions prompt the search for new molecular targets. TSPO is an 18 KDa protein located in the outer mitochondrial membrane, which can be traced by positron emission tomography (PET) using specific ligands. TSPO is located mostly in neurons and inflammatory sites outside the brain. We hypothesized that it might also be expressed in the human endometrium and endometrial-like tissue, being a target for molecular imaging of endometriosis. This prospective cross-sectional study included 28 women with endometriosis and 11 endometriosis-free controls. Endometriotic lesions (n = 49) and normal peritoneum (n = 13) from endometriosis patients were obtained during laparoscopy, while samples of eutopic endometrium from patients with endometriosis (n = 28) and from control women (n = 11) were collected in the operating room using a flexible device. TSPO mRNA expression was evaluated by quantitative reverse-transcription real-time PCR while protein expression was evaluated by immunohistochemistry with a monoclonal antibody antihuman TSPO. TSPO mRNA expression was detected in an invariable fashion in all tissue types evaluated; however, TSPO protein was found to be more abundant in the glandular epithelium than in the stroma, both in the endometrium and in the endometriotic lesions. Interestingly, hormone therapies did not alter the expression of TSPO, and its presence was mostly negative in tissues adjacent to endometriotic implants. As a proof of concept, the protein expression pattern of TSPO in endometriotic tissue and along the adjacent areas suggests that TSPO-based molecular imaging might be used for noninvasive endometriosis detection.
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Affiliation(s)
- Maíra Casalechi
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Cynthia Dela Cruz
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Wiviane A Assis
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Millene Vieira-Lopes
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Felipe Eduardo F Lopes
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Antônio M C Francisco
- Maternal and Child Department, Universidade do Vale do Sapucaí, Pouso Alegre, Brazil
| | - Fernando M Reis
- Department of Obstetrics and Gynecology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Li D, Hu D, Ochi Y, Arakaki W, Mawatari A, Shigeta M, Wu Y, Hayashinaka E, Neyama H, Tahara T, Wada Y, Li F, Doi H, Watanabe Y, Cui Y. Regional neuroinflammation induced by peripheral infection contributes to fatigue-like symptoms: a [ 18F]DPA-714 positron emission tomography study in rats. Front Immunol 2023; 14:1261256. [PMID: 38022622 PMCID: PMC10665845 DOI: 10.3389/fimmu.2023.1261256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction A series of symptoms, including fever, widespread pain, fatigue, and even ageusia, have frequently been reported in the context of various infections, such as COVID-19. Although the pathogenic mechanisms underlying an infection causing fever and pain have been well established, the mechanisms of fatigue induced by infection in specific brain regions remain unclear. Methods To elucidate whether and how the peripheral infection cause fatigue via regional neuroinflammation, we performed a brain-wide investigation of neuroinflammation in a peripheral pseudoinfection rat model using [18F]DPA-714 positron emission tomography (PET) imaging analysis, in which the polyriboinosinic: polyribocytidylic acid (poly I:C) was intraperitoneally injected. Results Transient fever lasting for several hours and subsequent suppression of spontaneous activity lasting a few days were induced by poly I:C treatment. Significant increase in plasma interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α were observed at 2 and 4 h following poly I:C treatment. PET imaging analysis revealed that the brain uptake of [18F]DPA-714 was significantly increased in several brain regions one day after poly I:C treatment, such as the dorsal raphe (DR), parvicellular part of red nucleus (RPC), A5 and A7 noradrenergic nucleus, compared with the control group. The accumulation of [18F]DPA-714 in the DR, RPC and A5 was positively correlated with subsequent fatigue-like behavior, and that in the A7 tended to positively correlate with fever. Discussion These findings suggest that peripheral infection may trigger regional neuroinflammation, which may cause specific symptoms such as fatigue. A similar mechanism might be involved in COVID-19.
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Affiliation(s)
- Danxi Li
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
- Department of Chinese Medicine Diagnostics, School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- Institute for Brain Disorders, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Di Hu
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yuta Ochi
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Wakiko Arakaki
- Laboratory for Labeling Chemistry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Aya Mawatari
- Laboratory for Labeling Chemistry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Mika Shigeta
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yuping Wu
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Emi Hayashinaka
- Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Hiroyuki Neyama
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Tsuyoshi Tahara
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yasuhiro Wada
- Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Feng Li
- Department of Chinese Medicine Diagnostics, School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Hisashi Doi
- Laboratory for Labeling Chemistry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yasuyoshi Watanabe
- Laboratory for Pathophysiological and Health Science, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yilong Cui
- Laboratory for Biofunction Dynamics Imaging, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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Cheval M, Rodrigo S, Taussig D, Caillé F, Petrescu AM, Bottlaender M, Tournier N, Besson FL, Leroy C, Bouilleret V. [ 18F]DPA-714 PET Imaging in the Presurgical Evaluation of Patients With Drug-Resistant Focal Epilepsy. Neurology 2023; 101:e1893-e1904. [PMID: 37748889 PMCID: PMC10663012 DOI: 10.1212/wnl.0000000000207811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/17/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Translocator protein 18 kDa (TSPO) PET imaging is used to monitor glial activation. Recent studies have proposed TSPO PET as a marker of the epileptogenic zone (EZ) in drug-resistant focal epilepsy (DRFE). This study aims to assess the contributions of TSPO imaging using [18F]DPA-714 PET and [18F]FDG PET for localizing the EZ during presurgical assessment of DRFE, when phase 1 presurgical assessment does not provide enough information. METHODS We compared [18F]FDG and [18F]DPA-714 PET images of 23 patients who had undergone a phase 1 presurgical assessment, using qualitative visual analysis and quantitative analysis, at both the voxel and the regional levels. PET abnormalities (increase in binding for [18F]DPA-714 vs decrease in binding for [18F]FDG) were compared with clinical hypotheses concerning the localization of the EZ based on phase 1 presurgical assessment. The additional value of [18F]DPA-714 PET imaging to [18F]FDG for refining the localization of the EZ was assessed. To strengthen the visual analysis, [18F]DPA-714 PET imaging was also reviewed by 2 experienced clinicians blind to the EZ location. RESULTS The study included 23 patients. Visual analysis of [18F]DPA-714 PET was significantly more accurate than [18F]FDG PET to both, show anomalies (95.7% vs 56.5%, p = 0.022), and provide additional information to refine the EZ localization (65.2% vs 17.4%, p = 0.019). All 10 patients with normal [18F]FDG PET had anomalies when using [18F]DPA-714 PET. The additional value of [18F]DPA-714 PET seemed to be greater in patients with normal brain MRI or with neocortical EZ (especially if insula is involved). Regional analysis of [18F]DPA-714 and [18F]FDG PET provided similar results. However, using voxel-wise analysis, [18F]DPA-714 was more effective than [18F]FDG for unveiling clusters whose localization was more often consistent with the EZ hypothesis (87.0% vs 39.1%, p = 0.019). Nonrelevant bindings were seen in 14 of 23 patients in visual analysis and 9 patients of 23 patients in voxel-wise analysis. DISCUSSION [18F]DPA-714 PET imaging provides valuable information for presurgical assessments of patients with DRFE. TSPO PET could become an additional tool to help to the localization of the EZ, especially in patients with negative [18F]FDG PET. TRIAL REGISTRATION INFORMATION Eudract 2017-003381-27. Inclusion of the first patient: September 24, 2018. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence on the utility of [18F]DPA-714 PET compared with [18F]FDG PET in identifying the epileptic zone in patients undergoing phase 1 presurgical evaluation for intractable epilepsy.
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Affiliation(s)
- Margaux Cheval
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France.
| | - Sebastian Rodrigo
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Delphine Taussig
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Fabien Caillé
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Ana Maria Petrescu
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Michel Bottlaender
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Nicolas Tournier
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Florent L Besson
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Claire Leroy
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Viviane Bouilleret
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
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6
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Lin Q, Wang Y, Zhao W, Yao S. Visualization of Thromboinflammation by 18F-DPA-714 PET in a Stroke Patient. Clin Nucl Med 2023; 48:e477-e479. [PMID: 37682615 DOI: 10.1097/rlu.0000000000004803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
ABSTRACT A 44-year-old man who presented with progressive right limb weakness was diagnosed with ischemic stroke. He was referred for 18F-DPA-714 PET/CT for evaluation of the disease. 18F-DPA-714 PET/CT showed increased uptake of the intracranial thrombus. This DPA-714-avid thrombus highly suggested the involvement of immune cells in the extension of the clot resulting in neurological deterioration. This present case suggested that 18F-DPA-714 PET might be a promising tracer in visualizing thromboinflammation in vivo.
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Affiliation(s)
- Qianqian Lin
- From the Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University
| | - Youliang Wang
- From the Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University
| | - Wenlong Zhao
- From the Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University
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Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
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Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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8
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Peyronneau MA, Kuhnast B, Nguyen DL, Jego B, Sayet G, Caillé F, Lavisse S, Gervais P, Stankoff B, Sarazin M, Remy P, Bouilleret V, Leroy C, Bottlaender M. [ 18F]DPA-714: Effect of co-medications, age, sex, BMI and TSPO polymorphism on the human plasma input function. Eur J Nucl Med Mol Imaging 2023; 50:3251-3264. [PMID: 37291448 DOI: 10.1007/s00259-023-06286-1] [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: 12/06/2022] [Accepted: 05/16/2023] [Indexed: 06/10/2023]
Abstract
PURPOSE We aimed to assess the effect of concomitant medication, age, sex, body mass index and 18-kDa translocator protein (TSPO) binding affinity status on the metabolism and plasma pharmacokinetics of [18F]DPA-714 and their influence on the plasma input function in a large cohort of 201 subjects who underwent brain and whole-body PET imaging to investigate the role of neuroinflammation in neurological diseases. METHODS The non-metabolized fraction of [18F]DPA-714 was estimated in venous plasma of 138 patients and 63 healthy controls (HCs; including additional arterial sampling in 16 subjects) during the 90 min brain PET acquisition using a direct solid-phase extraction method. The mean fraction between 70 and 90 min post-injection ([18F]DPA-71470-90) and corresponding normalized plasma concentration (SUV70-90) were correlated with all factors using a multiple linear regression model. Differences between groups (arterial vs venous measurements; HCs vs patients; high- (HAB), mixed- (MAB) and low-affinity binders (LAB); subjects with vs without co-medications, females vs males were also assessed using the non-parametric Mann-Whitney or Kruskal-Wallis ANOVA tests. Finally, the impact of co-medications on the brain uptake of [18F]DPA-714 at equilibrium was investigated. RESULTS As no significant differences were observed between arterial and venous [18F]DPA-71470-90 and SUV70-90, venous plasma was used for correlations. [18F]DPA-71470-90 was not significantly different between patients and HCS (59.7 ± 12.3% vs 60.2 ± 12.9%) despite high interindividual variability. However, 47 subjects exhibiting a huge increase or decrease of [18F]DPA-71470-90 (up to 88% or down to 23%) and SUV70-90 values (2-threefold) were found to receive co-medications identified as inhibitors or inducers of CYP3A4, known to catalyse [18F]DPA-714 metabolism. Comparison between cortex-to-plasma ratios using individual input function (VTIND) or population-based input function derived from untreated HCs (VTPBIF) indicated that non-considering the individual metabolism rate led to a bias of about 30% in VT values. Multiple linear regression model analysis of subjects free of these co-medications suggested significant correlations between [18F]DPA-71470-90 and age, BMI and sex while TSPO polymorphism did not influence the metabolism of the radiotracer. [18F]DPA-714 metabolism fell with age and BMI and was significantly faster in females than in males. Whole-body PET/CT exhibited a high uptake of the tracer in TSPO-rich organs (heart wall, spleen, kidneys…) and those involved in metabolism and excretion pathways (liver, gallbladder) in HAB and MAB with a strong decrease in LAB (-89% and -85%) resulting in tracer accumulation in plasma (4.5 and 3.3-fold increase). CONCLUSION Any co-medication that inhibits or induces CYP3A4 as well as TSPO genetic status, age, BMI and sex mostly contribute to interindividual variations of the radiotracer metabolism and/or concentration that may affect the input function of [18F]DPA-714 and consequently its human brain and peripheral uptake. TRIAL REGISTRATION INFLAPARK, NCT02319382, registered December 18, 2014, retrospectively registered; IMABIO 3, NCT01775696, registered January 25, 2013, retrospectively registered; INFLASEP, NCT02305264, registered December 2, 2014, retrospectively registered; EPI-TEP, EudraCT 2017-003381-27, registered September 24, 2018.
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Affiliation(s)
- M A Peyronneau
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France.
| | - B Kuhnast
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - D-L Nguyen
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - B Jego
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - G Sayet
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - F Caillé
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - S Lavisse
- Laboratoire Des Maladies Neurodégénératives, Université Paris-Saclay, CEA, CNRS, MIRCen, F-92265, Fontenay-Aux-Roses, France
| | - P Gervais
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - B Stankoff
- Sorbonne Université, UPMC Paris 06, Institut du Cerveau et de La Moelle Epinière, Hôpital de La Pitié Salpêtrière, Inserm UMR S 1127, CNRS UMR 7225, Paris, France
| | - M Sarazin
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
- Service de Neurologie de La Mémoire Et du Langage, GHU Paris Psychiatrie & Neurosciences, Hôpital Sainte Anne, F-75014, Paris, France
| | - P Remy
- Laboratoire Des Maladies Neurodégénératives, Université Paris-Saclay, CEA, CNRS, MIRCen, F-92265, Fontenay-Aux-Roses, France
- Centre Expert Parkinson, Neurologie, Hôpital Henri Mondor, AP-HP, F-94010, Créteil, France
- Université Paris-Est Créteil, INSERM U955, Institut Mondor de Recherche Biomédicale, Equipe NeuroPsychologie Interventionnelle, F-94010, Créteil, France
- Département d'Etudes Cognitives, École Normale Supérieure, Université PSL, F-75005, Paris, France
| | - V Bouilleret
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
- Service de Neurophysiologie Clinique et d'Epileptologie, Hôpital Bicêtre, AP-HP, Université Paris Saclay, F-94270, Le Kremlin-Bicêtre, France
| | - C Leroy
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
| | - M Bottlaender
- Université Paris Saclay, INSERM, CNRS, CEA, Laboratoire d'Imagerie Biomedicale Multimodale (BioMaps), Service Hospitalier Frédéric Joliot, 4 Place du Général Leclerc, F-91401, ORSAY, France
- Université Paris Saclay, UNIACT, Neurospin, CEA, Gif-Sur-Yvette, F-91190, France
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9
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Jamali AM, Kethamreddy M, Burkett BJ, Port JD, Pandey MK. PET and SPECT Imaging of ALS: An Educational Review. Mol Imaging 2023; 2023:5864391. [PMID: 37636591 PMCID: PMC10460279 DOI: 10.1155/2023/5864391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/11/2023] [Accepted: 07/25/2023] [Indexed: 08/29/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a disease leading to progressive motor degeneration and ultimately death. It is a complex disease that can take a significantly long time to be diagnosed, as other similar pathological conditions must be ruled out for a definite diagnosis of ALS. Noninvasive imaging of ALS has shed light on disease pathology and altered biochemistry in the ALS brain. Other than magnetic resonance imaging (MRI), two types of functional imaging, positron emission tomography (PET) and single photon emission computed tomography (SPECT), have provided valuable data about what happens in the brain of ALS patients compared to healthy controls. PET imaging has revealed a specific pattern of brain metabolism through [18F]FDG, while other radiotracers have uncovered neuroinflammation, changes in neuronal density, and protein aggregation. SPECT imaging has shown a general decrease in regional cerebral blood flow (rCBF) in ALS patients. This educational review summarizes the current state of ALS imaging with various PET and SPECT radiopharmaceuticals to better understand the pathophysiology of ALS.
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Affiliation(s)
| | | | | | - John D. Port
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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10
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Ye P, Bi L, Yang M, Qiu Y, Huang G, Liu Y, Hou Y, Li Z, Tong HHY, Cui M, Jin H. Activated Microglia in the Early Stage of a Rat Model of Parkinson's Disease: Revealed by PET-MRI Imaging by [ 18F]DPA-714 Targeting TSPO. ACS Chem Neurosci 2023. [PMID: 37146429 DOI: 10.1021/acschemneuro.3c00080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
In the past decades, translocator protein (TSPO) has been considered as an in vivo biomarker to measure the presence of neuroinflammatory reactions. In this study, expression of TSPO was quantified via [18F]DPA-714 positron emission tomography-magnetic resonance imaging (PET-MRI) imaging to investigate the effects of microglial activation associated with motor behavioral impairments in the 6-hydroxydopamine (6-OHDA)-treated rodent model of Parkinson's disease (PD). [18F]FDG PET-MRI (for non-specific inflammation), [18F]D6-FP-(+)-DTBZ PET-MRI (for damaged dopaminergic neurons), post-PET immunofluorescence, and Pearson's correlation analyses were also performed. The time course of the striatal [18F]DPA-714 binding ratio elevated in 6-OHDA-treated rats during 1-3 weeks post-treatment, with the peak TSPO binding in the 1st week. No differences between bilateral striatum in [18F]FDG PET imaging were found. Moreover, an obvious correlation between [18F]DPA-714 SUVRR/L and rotation numbers was found (r = 0.434, *p = 0.049). No correlation between [18F]FDG SUVRR/L and rotation behavior was found. [18F]DPA-714 appeared to be a potential PET tracer for imaging the microglia-mediated neuroinflammation in the early stage of PD.
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Affiliation(s)
- Peizhen Ye
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Lei Bi
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Min Yang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Yifan Qiu
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Guolong Huang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Yongshan Liu
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Yuyi Hou
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Zhijun Li
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
| | - Henry Hoi Yee Tong
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao SAR 999078, China
| | - Mengchao Cui
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Hongjun Jin
- Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong 519000, China
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11
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Ye P, Bi L, Yang M, Qiu Y, Huang G, Liu Y, Hou Y, Li Z, Yee Tong HH, Cui M, Jin H. Activated Microglia in the Early Stage of a Rat Model of Parkinson's Disease: Revealed by PET-MRI Imaging by [ 18F]DPA-714 Targeting TSPO. ACS Chem Neurosci 2023. [PMID: 37134001 DOI: 10.1021/acschemneuro.3c00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
In the past decades, translocator protein (TSPO) has been considered as an in vivo biomarker to measure the presence of neuroinflammatory reactions. In this study, expression of TSPO was quantified via [18F]DPA-714 positron emission tomography-magnetic resonance imaging (PET-MRI) to investigate the effects of microglial activation associated with motor behavioral impairments in the 6-hydroxydopamine (6-OHDA)-treated rodent model of Parkinson's disease (PD). [18F]FDG PET-MRI (for non-specific inflammation), [18F]D6-FP-(+)-DTBZ PET-MRI (for damaged dopaminergic (DA) neurons), post-PET immunofluorescence, and Pearson's correlation analyses were also performed. The time course of striatal [18F]DPA-714 binding ratio was elevated in 6-OHDA-treated rats during 1-3 weeks post-treatments, with peak TSPO binding in the 1st week. No difference between the bilateral striatum in [18F]FDG PET imaging were found. Moreover, an obvious correlation between [18F]DPA-714 SUVRR/L and rotation numbers was found (r = 0.434, *p = 0.049). No correlation between [18F]FDG SUVRR/L and rotation behavior was found. [18F]DPA-714 appeared to be a potential PET tracer for imaging the microglia-mediated neuroinflammation in the early stage of PD.
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Affiliation(s)
- Peizhen Ye
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Lei Bi
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Min Yang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Yifan Qiu
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Guolong Huang
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Yongshan Liu
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Yuyi Hou
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Zhijun Li
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
| | - Henry Hoi Yee Tong
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao SAR 999078, China
| | - Mengchao Cui
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Hongjun Jin
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai City 519000, Guangdong Province, China
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12
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Neumann KD, Seshadri V, Thompson XD, Broshek DK, Druzgal J, Massey JC, Newman B, Reyes J, Simpson SR, McCauley KS, Patrie J, Stone JR, Kundu BK, Resch JE. Microglial activation persists beyond clinical recovery following sport concussion in collegiate athletes. Front Neurol 2023; 14:1127708. [PMID: 37034078 PMCID: PMC10080132 DOI: 10.3389/fneur.2023.1127708] [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: 12/20/2022] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction In concussion, clinical and physiological recovery are increasingly recognized as diverging definitions. This study investigated whether central microglial activation persisted in participants with concussion after receiving an unrestricted return-to-play (uRTP) designation using [18F]DPA-714 PET, an in vivo marker of microglia activation. Methods Eight (5 M, 3 F) current athletes with concussion (Group 1) and 10 (5 M, 5 F) healthy collegiate students (Group 2) were enrolled. Group 1 completed a pre-injury (Visit1) screen, follow-up Visit2 within 24 h of a concussion diagnosis, and Visit3 at the time of uRTP. Healthy participants only completed assessments at Visit2 and Visit3. At Visit2, all participants completed a multidimensional battery of tests followed by a blood draw to determine genotype and study inclusion. At Visit3, participants completed a clinical battery of tests, brain MRI, and brain PET; no imaging tests were performed outside of Visit3. Results For Group 1, significant differences were observed between Visits 1 and 2 (p < 0.05) in ImPACT, SCAT5 and SOT performance, but not between Visit1 and Visit3 for standard clinical measures (all p > 0.05), reflecting clinical recovery. Despite achieving clinical recovery, PET imaging at Visit3 revealed consistently higher [18F]DPA-714 tracer distribution volume (VT) of Group 1 compared to Group 2 in 10 brain regions (p < 0.001) analyzed from 164 regions of the whole brain, most notably within the limbic system, dorsal striatum, and medial temporal lobe. No notable differences were observed between clinical measures and VT between Group 1 and Group 2 at Visit3. Discussion Our study is the first to demonstrate persisting microglial activation in active collegiate athletes who were diagnosed with a sport concussion and cleared for uRTP based on a clinical recovery.
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Affiliation(s)
- Kiel D Neumann
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Vikram Seshadri
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Xavier D Thompson
- Department of Kinesiology, University of Virginia, Charlottesville, VA, United States
| | - Donna K Broshek
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, United States
| | - Jason Druzgal
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - James C Massey
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Benjamin Newman
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Jose Reyes
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Spenser R Simpson
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Katelyenn S McCauley
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - James Patrie
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
| | - James R Stone
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, United States
| | - Bijoy K Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Jacob E Resch
- Department of Kinesiology, University of Virginia, Charlottesville, VA, United States
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Multi-Targeted Neutron Capture Therapy Combined with an 18 kDa Translocator Protein-Targeted Boron Compound Is an Effective Strategy in a Rat Brain Tumor Model. Cancers (Basel) 2023; 15:cancers15041034. [PMID: 36831378 PMCID: PMC9953932 DOI: 10.3390/cancers15041034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/30/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Boron neutron capture therapy (BNCT) has been adapted to high-grade gliomas (HG); however, some gliomas are refractory to BNCT using boronophenylalanine (BPA). In this study, the feasibility of BNCT targeting the 18 kDa translocator protein (TSPO) expressed in glioblastoma and surrounding environmental cells was investigated. METHODS Three rat glioma cell lines, an F98 rat glioma bearing brain tumor model, DPA-BSTPG which is a boron-10 compound targeting TSPO, BPA, and sodium borocaptate (BSH) were used. TSPO expression was evaluated in the F98 rat glioma model. Boron uptake was assessed in three rat glioma cell lines and in the F98 rat glioma model. In vitro and in vivo neutron irradiation experiments were performed. RESULTS DPA-BSTPG was efficiently taken up in vitro. The brain tumor has 16-fold higher TSPO expressions than its brain tissue. The compound biological effectiveness value of DPA-BSTPG was 8.43 to F98 rat glioma cells. The boron concentration in the tumor using DPA-BSTPG convection-enhanced delivery (CED) administration was approximately twice as high as using BPA intravenous administration. BNCT using DPA-BSTPG has significant efficacy over the untreated group. BNCT using a combination of BPA and DPA-BSTPG gained significantly longer survival times than using BPA alone. CONCLUSION DPA-BSTPG in combination with BPA may provide the multi-targeted neutron capture therapy against HG.
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14
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Deeva OA, Yarkova MA, Mokrov GV, Gudasheva TA, Seredenin SB. Dipeptide Ligands of TSPO. Pharm Chem J 2022. [DOI: 10.1007/s11094-022-02772-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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15
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18F-Radiolabeled Translocator Protein (TSPO) PET Tracers: Recent Development of TSPO Radioligands and Their Application to PET Study. Pharmaceutics 2022; 14:pharmaceutics14112545. [PMID: 36432736 PMCID: PMC9697781 DOI: 10.3390/pharmaceutics14112545] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Translocator protein 18 kDa (TSPO) is a transmembrane protein in the mitochondrial membrane, which has been identified as a peripheral benzodiazepine receptor. TSPO is generally present at high concentrations in steroid-producing cells and plays an important role in steroid synthesis, apoptosis, and cell proliferation. In the central nervous system, TSPO expression is relatively modest under normal physiological circumstances. However, some pathological disorders can lead to changes in TSPO expression. Overexpression of TSPO is associated with several diseases, such as neurodegenerative diseases, neuroinflammation, brain injury, and cancers. TSPO has therefore become an effective biomarker of related diseases. Positron emission tomography (PET), a non-invasive molecular imaging technique used for the clinical diagnosis of numerous diseases, can detect diseases related to TSPO expression. Several radiolabeled TSPO ligands have been developed for PET. In this review, we describe recent advances in the development of TSPO ligands, and 18F-radiolabeled TSPO in particular, as PET tracers. This review covers pharmacokinetic studies, preclinical and clinical trials of 18F-labeled TSPO PET ligands, and the synthesis of TSPO ligands.
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16
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Hammouda MM, Gaffer HE, Elattar KM. Insights into the medicinal chemistry of heterocycles integrated with a pyrazolo[1,5- a]pyrimidine scaffold. RSC Med Chem 2022; 13:1150-1196. [PMID: 36325400 PMCID: PMC9580358 DOI: 10.1039/d2md00192f] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/25/2022] [Indexed: 09/10/2023] Open
Abstract
Pyrazolo[1,5-a]pyrimidines are the dominant motif of many drugs; for instance, zaleplon and indiplon are sedative agents and ocinaplon was identified as an anxiolytic agent. The importance of this class of compounds lies in its varied and significant biological activities, and accordingly, considerable methods have been devised to prepare these compounds. Hence, other derivatives of this class of compounds were prepared by substitution reactions with different nucleophiles exploiting the activity of groups linked to the ring carbon and nitrogen atoms. The methods used vary through the condensation reactions of the aminopyrazoles with 1,2-allenic, enaminonitriles, enaminones, 1,3-diketones, unsaturated nitriles, or unsaturated ketones. Alternatively, these compounds are prepared through the reactions of acyclic reagents, as these methods were recently developed efficiently with high yields. The current review highlighted the recent progress of the therapeutic potential of pyrazolo[1,5-a]pyrimidines as antimicrobial, anticancer, antianxiety, anti-proliferative, analgesic, and antioxidant agents, carboxylesterase, translocator protein and PDE10A inhibitors, and selective kinase inhibitors.
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Affiliation(s)
- Mohamed M Hammouda
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University Al-Kharj 11942 Saudi Arabia
- Chemistry Department, Faculty of Science, Mansoura University El-Gomhoria Street Mansoura 35516 Egypt
| | - Hatem E Gaffer
- Dyeing and Printing Department, Textile Research Division, National Research Center Dokki Cairo 12622 Egypt
| | - Khaled M Elattar
- Unit of Genetic Engineering and Biotechnology, Faculty of Science, Mansoura University El-Gomhoria Street Mansoura 35516 Egypt +201010655354
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17
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The Anti-Inflammatory Effect of Preventive Intervention with Ketogenic Diet Mediated by the Histone Acetylation of mGluR5 Promotor Region in Rat Parkinson’s Disease Model: A Dual-Tracer PET Study. PARKINSON'S DISEASE 2022; 2022:3506213. [PMID: 36105302 PMCID: PMC9467749 DOI: 10.1155/2022/3506213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 08/05/2022] [Indexed: 11/24/2022]
Abstract
Materials and Methods The neuroprotective effect of ketosis state prior to the onset of PD (preventive KD, KDp) was compared with that receiving KD after the onset (therapeutic KD, KDt) in the lipopolysaccharide- (LPS-) induced rat PD model. A total of 100 rats were randomly assigned to the following 4 groups: sham, LPS, LPS + KDp, and LPS + KDt groups. Results Significant dopamine deficient behaviors (rotational behavior and contralateral forelimb akinesia), upregulation of proinflammatory mediators (TNF-α, IL-1β, and IL-6), loss of dopaminergic neurons, reduction of mGluR5+ microglia cells, increase of TSPO+ microglia cells, reduction of H3K9 acetylation in the mGluR5 promoter region and mGluR5 mRNA expression, and decline in the phosphorylation levels of Akt/GSK-3β/CREB pathway were observed after the intervention of LPS (P < 0.01). TSPO and DAT PET imaging revealed the increased uptake of 18F-DPA-714 in substantia nigra and decreased uptake of 18F-FP-CIT in substantia nigra and striatum in LPS-treated rats (P < 0.001). These impairments were alleviated by the dietary intervention of KD, especially with the strategy of KDp (P < 0.05). Conclusions The anti-inflammatory effect of KD on PD was supposed to be related to the modulation of Akt/GSK-3β/CREB signaling pathway mediated by the histone acetylation of mGluR5 promotor region. The KD intervention should be initiated prior to the PD onset in high-risk population to achieve a more favorable outcome.
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18
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Barca C, Kiliaan AJ, Wachsmuth L, Foray C, Hermann S, Faber C, Schäfers M, Wiesmann M, Zinnhardt B, Jacobs AH. Short-Term Colony-Stimulating Factor 1 Receptor Inhibition-Induced Repopulation After Stroke Assessed by Longitudinal 18F-DPA-714 PET Imaging. J Nucl Med 2022; 63:1408-1414. [PMID: 35115368 PMCID: PMC9454465 DOI: 10.2967/jnumed.121.263004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/12/2022] [Indexed: 01/26/2023] Open
Abstract
Studies on colony-stimulating factor 1 receptor (CSF-1R) inhibition-induced microglia depletion indicated that inhibitor withdrawal allowed the renewal of the microglia compartment via repopulation and resolved the inflammatory imbalance. Therefore, we investigated for the first time (to our knowledge) the effects of microglia repopulation on inflammation and functional outcomes in an ischemic mouse model using translocator protein (TSPO)-PET/CT and MR imaging, ex vivo characterization, and behavioral tests. Methods: Eight C57BL/6 mice per group underwent a 30-min transient occlusion of the middle cerebral artery. The treatment group received CSF-1R inhibitor in 1,200 ppm PLX5622 chow (Plexxikon Inc.) from days 3 to 7 to induce microglia/macrophage depletion and then went back to a control diet to allow repopulation. The mice underwent T2-weighted MRI on day 1 after ischemia and 18F-labeled N,N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-α]pyrimidine-3-yl)acetamide (18F-DPA-714) (TSPO) PET/CT on days 7, 14, 21, and 30. The percentage injected tracer dose per milliliter within the infarct, contralateral striatum, and spleen was assessed. Behavioral tests were performed to assess motor function recovery. Brains were harvested on days 14 and 35 after ischemia for ex vivo analyses (immunoreactivity and real-time quantitative polymerase chain reaction) of microglia- and macrophage-related markers. Results: Repopulation significantly increased 18F-DPA-714 uptake within the infarct on days 14 (P < 0.001) and 21 (P = 0.002) after ischemia. On day 14, the ionized calcium binding adaptor molecule 1 (Iba-1)-positive cell population showed significantly higher expression of TSPO, CSF-1R, and CD68, in line with microglia repopulation. Gene expression analyses on day 14 indicated a significant increase in microglia-related markers (csf-1r, aif1, and p2ry12) with repopulation, whereas peripheral cell recruitment-related gene expression decreased (cx3cr1 and ccr2), indicative of peripheral recruitment during CSF-1R inhibition. Similarly, uncorrected spleen uptake was significantly higher on day 7 after ischemia with treatment (P = 0.001) and decreased after drug withdrawal. PLX5622-treated mice walked a longer distance (P < 0.001) and more quickly (P = 0.009), and showed greater forelimb strength (P < 0.001), than control mice on day 14. Conclusion: This study highlighted the potential of 18F-DPA-714 PET/CT imaging to track microglia and macrophage repopulation after short-term CSF-1R inhibition in stroke.
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Affiliation(s)
- Cristina Barca
- European Institute for Molecular Imaging, University of Münster, Münster, Germany;
| | - Amanda J. Kiliaan
- Department of Medical Imaging/Anatomy, Radboud University Medical Center, Radboud, The Netherlands
| | - Lydia Wachsmuth
- Translational Research Imaging Center, University Hospital Münster, Münster, Germany
| | - Claudia Foray
- European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Sven Hermann
- European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Cornelius Faber
- Translational Research Imaging Center, University Hospital Münster, Münster, Germany
| | - Michael Schäfers
- European Institute for Molecular Imaging, University of Münster, Münster, Germany;,Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Maximilian Wiesmann
- Department of Medical Imaging/Anatomy, Radboud University Medical Center, Radboud, The Netherlands
| | - Bastian Zinnhardt
- European Institute for Molecular Imaging, University of Münster, Münster, Germany;,Department of Nuclear Medicine, University Hospital Münster, Münster, Germany;,Biomarkers and Translational Technologies, Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., Basel, Switzerland; and
| | - Andreas H. Jacobs
- European Institute for Molecular Imaging, University of Münster, Münster, Germany;,Department of Geriatrics and Neurology, Johanniter Hospital, Bonn, Germany
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19
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Viviano M, Barresi E, Siméon FG, Costa B, Taliani S, Da Settimo F, Pike VW, Castellano S. Essential Principles and Recent Progress in the Development of TSPO PET Ligands for Neuroinflammation Imaging. Curr Med Chem 2022; 29:4862-4890. [PMID: 35352645 PMCID: PMC10080361 DOI: 10.2174/0929867329666220329204054] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 12/21/2021] [Accepted: 01/25/2022] [Indexed: 11/22/2022]
Abstract
The translocator protein 18kDa (TSPO) is expressed in the outer mitochondrial membrane and is implicated in several functions, including cholesterol transport and steroidogenesis. Under normal physiological conditions, TSPO is present in very low concentrations in the human brain but is markedly upregulated in response to brain injury and inflammation. This upregulation is strongly associated with activated microglia. Therefore, TSPO is particularly suited for assessing active gliosis associated with brain lesions following injury or disease. For over three decades, TSPO has been studied as a biomarker. Numerous radioligands for positron emission tomography (PET) that target TSPO have been developed for imaging inflammatory progression in the brain. Although [11C]PK11195, the prototypical first-generation PET radioligand, is still widely used for in vivo studies, mainly now as its single more potent R-enantiomer, it has severe limitations, including low sensitivity and poor amenability to quantification. Second-generation radioligands are characterized by higher TSPO specific signals but suffer from other drawbacks, such as sensitivity to the TSPO single nucleotide polymorphism (SNP) rs6971. Therefore, their applications in human studies have the burden of needing to genotype subjects. Consequently, recent efforts are focused on developing improved radioligands that combine the optimal features of the second generation with the ability to overcome the differences in binding affinities across the population. This review presents essential principles in the design and development of TSPO PET ligands and discusses prominent examples among the main chemotypes.
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Affiliation(s)
- Monica Viviano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
| | | | - Fabrice G. Siméon
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Barbara Costa
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, 56126, Pisa, Italy
| | | | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sabrina Castellano
- Department of Pharmacy, University of Salerno, 84084 Fisciano (SA), Italy
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21
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van der Geest KSM, Sandovici M, Nienhuis PH, Slart RHJA, Heeringa P, Brouwer E, Jiemy WF. Novel PET Imaging of Inflammatory Targets and Cells for the Diagnosis and Monitoring of Giant Cell Arteritis and Polymyalgia Rheumatica. Front Med (Lausanne) 2022; 9:902155. [PMID: 35733858 PMCID: PMC9207253 DOI: 10.3389/fmed.2022.902155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/13/2022] [Indexed: 12/26/2022] Open
Abstract
Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two interrelated inflammatory diseases affecting patients above 50 years of age. Patients with GCA suffer from granulomatous inflammation of medium- to large-sized arteries. This inflammation can lead to severe ischemic complications (e.g., irreversible vision loss and stroke) and aneurysm-related complications (such as aortic dissection). On the other hand, patients suffering from PMR present with proximal stiffness and pain due to inflammation of the shoulder and pelvic girdles. PMR is observed in 40-60% of patients with GCA, while up to 21% of patients suffering from PMR are also affected by GCA. Due to the risk of ischemic complications, GCA has to be promptly treated upon clinical suspicion. The treatment of both GCA and PMR still heavily relies on glucocorticoids (GCs), although novel targeted therapies are emerging. Imaging has a central position in the diagnosis of GCA and PMR. While [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) has proven to be a valuable tool for diagnosis of GCA and PMR, it possesses major drawbacks such as unspecific uptake in cells with high glucose metabolism, high background activity in several non-target organs and a decrease of diagnostic accuracy already after a short course of GC treatment. In recent years, our understanding of the immunopathogenesis of GCA and, to some extent, PMR has advanced. In this review, we summarize the current knowledge on the cellular heterogeneity in the immunopathology of GCA/PMR and discuss how recent advances in specific tissue infiltrating leukocyte and stromal cell profiles may be exploited as a source of novel targets for imaging. Finally, we discuss prospective novel PET radiotracers that may be useful for the diagnosis and treatment monitoring in GCA and PMR.
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Affiliation(s)
- Kornelis S. M. van der Geest
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Maria Sandovici
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Pieter H. Nienhuis
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Riemer H. J. A. Slart
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Biomedical Photonic Imaging Group, University of Twente, Enschede, Netherlands
| | - Peter Heeringa
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Elisabeth Brouwer
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - William F. Jiemy
- Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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22
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Efficient and automatic synthesis of TSPO PET ligand [18F]-GE-180 and its application in rheumatoid arthritis model. Appl Radiat Isot 2022; 184:110213. [DOI: 10.1016/j.apradiso.2022.110213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/15/2022] [Accepted: 03/20/2022] [Indexed: 11/23/2022]
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Singh P, Adhikari A, Singh D, Gond C, Tiwari AK. The 18-kDa Translocator Protein PET Tracers as a Diagnostic Marker for Neuroinflammation: Development and Current Standing. ACS OMEGA 2022; 7:14412-14429. [PMID: 35557664 PMCID: PMC9089361 DOI: 10.1021/acsomega.2c00588] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/05/2022] [Indexed: 05/13/2023]
Abstract
Translocator protein (TSPO, 18 kDa) is an evolutionary, well-preserved, and tryptophan-rich 169-amino-acid protein which localizes on the contact sites between the outer and inner mitochondrial membranes of steroid-synthesizing cells. This mitochondrial protein is implicated in an extensive range of cellular activities, including steroid synthesis, cholesterol transport, apoptosis, mitochondrial respiration, and cell proliferation. The upregulation of TSPO is well documented in diverse disease conditions including neuroinflammation, cancer, brain injury, and inflammation in peripheral organs. On the basis of these outcomes, TSPO has been assumed to be a fascinating subcellular target for early stage imaging of the diseased state and for therapeutic purposes. The main outline of this Review is to give an update on dealing with the advances made in TSPO PET tracers for neuroinflammation, synchronously emphasizing the approaches applied for the design and advancement of new tracers with reference to their structure-activity relationship (SAR).
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Affiliation(s)
- Priya Singh
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Anupriya Adhikari
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Deepika Singh
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Chandraprakash Gond
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
| | - Anjani Kumar Tiwari
- Department
of Chemistry, Babasaheb Bhimrao Ambedkar
University (A Central University), Lucknow, 226025, Uttar Pradesh, India
- Address:
Department of Chemistry,
Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh. Tel.: +91-7503381343. Fax: +91-522-2440821. E-mail:
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24
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Shah S, Sinharay S, Patel R, Solomon J, Lee JH, Schreiber-Stainthorp W, Basuli F, Zhang X, Hagen KR, Reeder R, Wakim P, Huzella LM, Maric D, Johnson RF, Hammoud DA. PET imaging of TSPO expression in immune cells can assess organ-level pathophysiology in high-consequence viral infections. Proc Natl Acad Sci U S A 2022; 119:e2110846119. [PMID: 35385353 PMCID: PMC9169664 DOI: 10.1073/pnas.2110846119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 02/10/2022] [Indexed: 01/08/2023] Open
Abstract
Ebola virus (EBOV) disease is characterized by lymphopenia, breach in vascular integrity, cytokine storm, and multiorgan failure. The pathophysiology of organ involvement, however, is incompletely understood. Using [18F]-DPA-714 positron emission tomography (PET) imaging targeting the translocator protein (TSPO), an immune cell marker, we sought to characterize the progression of EBOV-associated organ-level pathophysiology in the EBOV Rhesus macaque model. Dynamic [18F]-DPA-714 PET/computed tomography imaging was performed longitudinally at baseline and at multiple time points after EBOV inoculation, and distribution volumes (Vt) were calculated as a measure of peripheral TSPO binding. Using a mixed-effect linear regression model, spleen and lung Vt decreased, while the bone marrow Vt increased over time after infection. No clear trend was found for liver Vt. Multiple plasma cytokines correlated negatively with lung/spleen Vt and positively with bone marrow Vt. Multiplex immunofluorescence staining in spleen and lung sections confirmed organ-level lymphoid and monocytic loss/apoptosis, thus validating the imaging results. Our findings are consistent with EBOV-induced progressive monocytic and lymphocytic depletion in the spleen, rather than immune activation, as well as depletion of alveolar macrophages in the lungs, with inefficient reactive neutrophilic activation. Increased bone marrow Vt, on the other hand, suggests hematopoietic activation in response to systemic immune cell depletion and leukocytosis and could have prognostic relevance. In vivo PET imaging provided better understanding of organ-level pathophysiology during EBOV infection. A similar approach can be used to delineate the pathophysiology of other systemic infections and to evaluate the effectiveness of newly developed treatment and vaccine strategies.
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Affiliation(s)
- Swati Shah
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892
| | - Sanhita Sinharay
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892
| | - Reema Patel
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892
| | - Jeffrey Solomon
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702
| | - Ji Hyun Lee
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, NIH, Frederick, MD 21702
| | | | - Falguni Basuli
- Chemistry and Synthesis Center, National Heart, Lung, and Blood Institute, NIH, Rockville, MD 20824
| | - Xiang Zhang
- Chemistry and Synthesis Center, National Heart, Lung, and Blood Institute, NIH, Rockville, MD 20824
| | - Katie R. Hagen
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, NIH, Frederick, MD 21702
| | - Rebecca Reeder
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, NIH, Frederick, MD 21702
| | - Paul Wakim
- Biostatistics and Clinical Epidemiology Service, Clinical Center, NIH, Bethesda, MD 20892
| | - Louis M. Huzella
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, NIH, Frederick, MD 21702
| | - Dragan Maric
- Flow and Imaging Cytometry Core Facility, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892
| | - Reed F. Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, NIH, Frederick, MD 21702
| | - Dima A. Hammoud
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD 20892
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25
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Assessment of the In Vivo Relationship Between Cerebral Hypometabolism, Tau Deposition, TSPO Expression, and Synaptic Density in a Tauopathy Mouse Model: a Multi-tracer PET Study. Mol Neurobiol 2022; 59:3402-3413. [PMID: 35312967 PMCID: PMC9148291 DOI: 10.1007/s12035-022-02793-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/05/2022] [Indexed: 11/03/2022]
Abstract
Cerebral glucose hypometabolism is a typical hallmark of Alzheimer’s disease (AD), usually associated with ongoing neurodegeneration and neuronal dysfunction. However, underlying pathological processes are not fully understood and reproducibility in animal models is not well established. The aim of the present study was to investigate the regional interrelation of glucose hypometabolism measured by [18F]FDG positron emission tomography (PET) with various molecular targets of AD pathophysiology using the PET tracers [18F]PI-2620 for tau deposition, [18F]DPA-714 for TSPO expression associated with neuroinflammation, and [18F]UCB-H for synaptic density in a transgenic tauopathy mouse model. Seven-month-old rTg4510 mice (n = 8) and non-transgenic littermates (n = 8) were examined in a small animal PET scanner with the tracers listed above. Hypometabolism was observed throughout the forebrain of rTg4510 mice. Tau pathology, increased TSPO expression, and synaptic loss were co-localized in the cortex and hippocampus and correlated with hypometabolism. In the thalamus, however, hypometabolism occurred in the absence of tau-related pathology. Thus, cerebral hypometabolism was associated with two regionally distinct forms of molecular pathology: (1) characteristic neuropathology of the Alzheimer-type including synaptic degeneration and neuroinflammation co-localized with tau deposition in the cerebral cortex, and (2) pathological changes in the thalamus in the absence of other markers of AD pathophysiology, possibly reflecting downstream or remote adaptive processes which may affect functional connectivity. Our study demonstrates the feasibility of a multitracer approach to explore complex interactions of distinct AD-pathomechanisms in vivo in a small animal model. The observations demonstrate that multiple, spatially heterogeneous pathomechanisms can contribute to hypometabolism observed in AD mouse models and they motivate future longitudinal studies as well as the investigation of possibly comparable pathomechanisms in human patients.
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Kinetic modeling and non-invasive approach for translocator protein quantification with 11C-DPA-713. Nucl Med Biol 2022; 108-109:76-84. [DOI: 10.1016/j.nucmedbio.2022.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 11/20/2022]
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[ 18F]DPA-714 PET imaging for the quantitative evaluation of early spatiotemporal changes of neuroinflammation in rat brain following status epilepticus. Eur J Nucl Med Mol Imaging 2022; 49:2265-2275. [PMID: 35157105 DOI: 10.1007/s00259-022-05719-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/06/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Most antiepileptic drug therapies are symptomatic and adversely suppress normal brain function by nonspecific inhibition of neuronal activity. In recent times, growing evidence has suggested that neuroinflammation triggered by epileptic seizures might be involved in the pathogenesis of epilepsy. Although the potential effectiveness of anti-inflammatory treatment for curing epilepsy has been extensively discussed, the limited quantitative data regarding spatiotemporal characteristics of neuroinflammation after epileptic seizures makes it difficult to be realized. We quantitatively analyzed the spatiotemporal changes in neuroinflammation in the early phase after status epilepticus in rats, using translocator protein (TSPO) positron emission tomography (PET) imaging, which has been widely used for the quantitative evaluation of neuroinflammation in several animal models of CNS disease. METHODS The second-generation TSPO PET probe, [18F]DPA-714, was used for brain-wide quantitative analysis of neuroinflammation in the brains of rats, when the status epilepticus was induced by subcutaneous injection of kainic acid (KA, 15 mg/kg) into those rats. A series of [18F]DPA-714 PET scans were performed at 1, 3, 7, and 15 days after status epilepticus, and the corresponding histological changes, including activation of microglia and astrocytes, were confirmed by immunohistochemistry. RESULTS Apparent accumulation of [18F]DPA-714 was observed in several KA-induced epileptogenic regions, such as the amygdala, piriform cortex, ventral hippocampus, mediodorsal thalamus, and cortical regions 3 days after status epilepticus, and was reversibly displaced by unlabeled PK11195 (1 mg/kg). Consecutive [18F]DPA-714 PET scans revealed that accumulation of [18F]DPA-714 was focused in the KA-induced epileptogenic regions from 3 days after status epilepticus and was further maintained in the amygdala and piriform cortex until 7 days after status epilepticus. Immunohistochemical analysis revealed that activated microglia but not reactive astrocytes were correlated with [18F]DPA-714 accumulation in the KA-induced epileptogenic regions for at least 1 week after status epilepticus. CONCLUSIONS These results indicate that the early spatiotemporal characteristics of neuroinflammation quantitatively evaluated by [18F]DPA-714 PET imaging provide valuable evidence for developing new anti-inflammatory therapies for epilepsy. The predominant activation of microglia around epileptogenic regions in the early phase after status epilepticus could be a crucial therapeutic target for curing epilepsy.
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28
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McCauley KS, Wilde JH, Bufalino SM, Neumann KD. An automated radiosynthesis of [ 18F]DPA-714 on a commercially available radiosynthesizer, Elixys Flex/Chem. Appl Radiat Isot 2022; 180:110032. [PMID: 34871885 PMCID: PMC8858596 DOI: 10.1016/j.apradiso.2021.110032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 02/03/2023]
Abstract
[18F]DPA-714 is a radiotracer specific to the translocator protein (TSPO) and is useful for in vivo Positron Emission Tomography imaging studies. In this report, we have developed an automated radiosynthesis of [18F]DPA-714 on a commercially-available radiosynthesis platform, which comports with USP <823> guidelines. The wide availability of the radiosynthesis module and ease of dissemination of the production sequence will facilitate preclinical and clinical research of TSPO-related pathology.
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Affiliation(s)
- Katelyenn S. McCauley
- Department of Radiology and Medical Imaging, University of
Virginia, Charlottesville, VA, USA
| | - Justin H. Wilde
- Department of Radiology and Medical Imaging, University of
Virginia, Charlottesville, VA, USA
| | - Sophia M. Bufalino
- Department of Chemistry, University of Virginia,
Charlottesville, VA, USA
| | - Kiel D. Neumann
- Department of Radiology and Medical Imaging, University of
Virginia, Charlottesville, VA, USA,Emily Couric Clinical Cancer Center, University of
Virginia, Charlottesville, VA, USA
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29
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Laudicella R, Quartuccio N, Argiroffi G, Alongi P, Baratto L, Califaretti E, Frantellizzi V, De Vincentis G, Del Sole A, Evangelista L, Baldari S, Bisdas S, Ceci F, Iagaru A. Unconventional non-amino acidic PET radiotracers for molecular imaging in gliomas. Eur J Nucl Med Mol Imaging 2021; 48:3925-3939. [PMID: 33851243 DOI: 10.1007/s00259-021-05352-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 04/04/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE The objective of this review was to explore the potential clinical application of unconventional non-amino acid PET radiopharmaceuticals in patients with gliomas. METHODS A comprehensive search strategy was used based on SCOPUS and PubMed databases using the following string: ("perfusion" OR "angiogenesis" OR "hypoxia" OR "neuroinflammation" OR proliferation OR invasiveness) AND ("brain tumor" OR "glioma") AND ("Positron Emission Tomography" OR PET). From all studies published in English, the most relevant articles were selected for this review, evaluating the mostly used PET radiopharmaceuticals in research centers, beyond amino acid radiotracers and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG), for the assessment of different biological features, such as perfusion, angiogenesis, hypoxia, neuroinflammation, cell proliferation, tumor invasiveness, and other biological characteristics in patients with glioma. RESULTS At present, the use of non-amino acid PET radiopharmaceuticals specifically designed to assess perfusion, angiogenesis, hypoxia, neuroinflammation, cell proliferation, tumor invasiveness, and other biological features in glioma is still limited. CONCLUSION The use of investigational PET radiopharmaceuticals should be further explored considering their promising potential and studies specifically designed to validate these preliminary findings are needed. In the clinical scenario, advancements in the development of new PET radiopharmaceuticals and new imaging technologies (e.g., PET/MR and the application of the artificial intelligence to medical images) might contribute to improve the clinical translation of these novel radiotracers in the assessment of gliomas.
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Affiliation(s)
- R Laudicella
- Department of Biomedical and Dental Sciences and Morpho-Functional Imaging, Nuclear Medicine Unit, University of Messina, Messina, Italy
| | - N Quartuccio
- Nuclear Medicine Unit, A.R.N.A.S. Ospedali Civico, Di Cristina e Benfratelli, Palermo, Italy
| | - G Argiroffi
- Department of Health Sciences, University of Milan, Milan, Italy
| | - P Alongi
- Nuclear Medicine Unit,, Fondazione Istituto G. Giglio, Ct. da Pietra Pollastra-pisciotto, Cefalù, Italy
| | - L Baratto
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Stanford University, Stanford, CA, USA
| | - E Califaretti
- Division of Nuclear Medicine, Department of Medical Sciences, University of Turin, Corso AM Dogliotti 14, 10126, Turin, Italy
| | - V Frantellizzi
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza, "Sapienza" University of Rome, Rome, Italy
| | - G De Vincentis
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza, "Sapienza" University of Rome, Rome, Italy
| | - A Del Sole
- Department of Health Sciences, University of Milan, Milan, Italy
| | - L Evangelista
- Nuclear Medicine Unit, Department of Medicine - DIMED, University of Padua, Padua, Italy
| | - S Baldari
- Department of Biomedical and Dental Sciences and Morpho-Functional Imaging, Nuclear Medicine Unit, University of Messina, Messina, Italy
| | - S Bisdas
- Department of Neuroradiology, University College London, London, UK
| | - Francesco Ceci
- Division of Nuclear Medicine, IEO European Institute of Oncology, IRCCS, Milan, Italy.
| | - Andrei Iagaru
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Stanford University, Stanford, CA, USA
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Privileged scaffolds in medicinal chemistry: Studies on pyrazolo[1,5-a]pyrimidines on sulfonamide containing Carbonic Anhydrase inhibitors. Bioorg Med Chem Lett 2021; 49:128309. [PMID: 34371130 DOI: 10.1016/j.bmcl.2021.128309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/19/2021] [Accepted: 08/03/2021] [Indexed: 12/28/2022]
Abstract
We report for the first time a small series of compounds endowed in vitro with inhibitory properties for the human (h) expressed Carbonic Anhydrase (CAs, E.C. 4.2.1.1) enzymes of physiological interest (i.e. I, II, VA, IX and XII) and bearing the pyrazolo[1,5-a]pyrimidine (PP) scaffold at the tail section. Among the series reported, 1a-3a, 7a, 8a, 1b and 2b resulted effective ligands and with good selectivities for the hCAs II, IX or XII. In consideration of the nearly matching KI values of 7a for both the hCA II and IX (i.e. 26.4 and 23.0 nM respectively) we explored its binding mode within the CA IX mimic isoform by means of X-ray crystal experiments on the corresponding adduct.
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Direct Comparison of [ 18F]F-DPA with [ 18F]DPA-714 and [ 11C]PBR28 for Neuroinflammation Imaging in the same Alzheimer's Disease Model Mice and Healthy Controls. Mol Imaging Biol 2021; 24:157-166. [PMID: 34542805 PMCID: PMC8760190 DOI: 10.1007/s11307-021-01646-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/22/2021] [Accepted: 08/23/2021] [Indexed: 11/02/2022]
Abstract
PURPOSE In this study we compared the recently developed TSPO tracer [18F]F-DPA, with [18F]DPA-714 and [11C]PBR28 by performing in vivo PET imaging on the same Alzheimer's disease mouse model APP/PS1-21 (TG) and wild-type (WT) mice with all three radiotracers. PROCEDURES To compare the radiotracer uptake, percentage of injected dose/mL (%ID/mL), standardized uptake value ratios to cerebellum (SUVRCB), and voxel-wise analyses were performed. RESULTS The peak uptake of [18F]F-DPA was higher than 4.3% ID/mL, while [18F]DPA-714 reached just over 3% ID/mL, and [11C]PBR28 was over 4% ID/mL in only one brain region in the WT mice. The peak/60-min uptake ratios of [18F]F-DPA were significantly higher (p < 0.001) than those of [18F]DPA-714 and [11C]PBR28. The differences in [18F]F-DPA SUVRCB between WT and TG mice were highly significant (p < 0.001) in the three studied time periods after injection. [18F]DPA-714 uptake was significantly higher in TG mice starting in the 20-40-min timeframe and increased thereafter, whereas [11C]PBR28 uptake became significant at 10-20 min (p < 0.05). The voxel-wise analysis confirmed the differences between the radiotracers. CONCLUSIONS [18F]F-DPA displays higher brain uptake, higher TG-to-WT SUVRCB ratios, and faster clearance than [18F]DPA-714 and [11C]PBR28, and could prove useful for detecting low levels of inflammation and allow for shorter dynamic PET scans.
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32
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Mattner F, Katsifis A, Bourdier T, Loc'h C, Berghofer P, Fookes C, Hung TT, Jackson T, Henderson D, Pham T, Lee BJ, Shepherd R, Greguric I, Wyatt N, Le T, Poon J, Power C, Fulham M. Synthesis and pharmacological evaluation of [ 18F]PBR316: a novel PET ligand targeting the translocator protein 18 kDa (TSPO) with low binding sensitivity to human single nucleotide polymorphism rs6971. RSC Med Chem 2021; 12:1207-1221. [PMID: 34355185 PMCID: PMC8292990 DOI: 10.1039/d1md00035g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/15/2021] [Indexed: 02/04/2023] Open
Abstract
Radiopharmaceuticals that target the translocator protein 18 kDa (TSPO) have been investigated with positron emission tomography (PET) to study neuroinflammation, neurodegeneration and cancer. We have developed the novel, achiral, 2-phenylimidazo[1,2-a]pyridine, PBR316 that targets the translocator protein 18 kDa (TSPO) that addresses some of the limitations inherent in current TSPO ligands; namely specificity in binding, blood brain barrier permeability, metabolism and insensitivity to TSPO binding in subjects as a result of rs6971 polymorphism. PBR316 has high nanomolar affinity (4.7-6.0 nM) for the TSPO, >5000 nM for the central benzodiazepine receptor (CBR) and low sensitivity to rs6971 polymorphism with a low affinity binders (LABs) to high affinity binders (HABs) ratio of 1.5. [18F]PBR316 was prepared in 20 ± 5% radiochemical yield, >99% radiochemical purity and a molar activity of 160-400 GBq μmol-1. Biodistribution in rats showed high uptake of [18F]PBR316 in organs known to express TSPO such as heart (3.9%) and adrenal glands (7.5% ID per g) at 1 h. [18F]PBR316 entered the brain and accumulated in TSPO-expressing regions with an olfactory bulb to brain ratio of 3 at 15 min and 7 at 4 h. Radioactivity was blocked by PK11195 and Ro 5-4864 but not Flumazenil. Metabolite analysis showed that radioactivity in adrenal glands and the brain was predominantly due to the intact radiotracer. PET-CT studies in mouse-bearing prostate tumour xenografts indicated biodistribution similar to rats with radioactivity in the tumour increasing with time. [18F]PBR316 shows in vitro binding that is insensitive to human polymorphism and has specific and selective in vivo binding to the TSPO. [18F]PBR316 is suitable for further biological and clinical studies.
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Affiliation(s)
- Filomena Mattner
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Andrew Katsifis
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
- School of Pharmacy, University of Sydney Sydney NSW 2006 Australia
| | - Thomas Bourdier
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Christian Loc'h
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Paula Berghofer
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Christopher Fookes
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Tzong-Tyng Hung
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Timothy Jackson
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - David Henderson
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Tien Pham
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Brendan J Lee
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Rachael Shepherd
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Ivan Greguric
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Naomi Wyatt
- Australian Nuclear Science and Technology Organisation Lucas Heights NSW Australia
| | - Thanh Le
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Jackson Poon
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
| | - Carl Power
- Biological Resources Imaging Laboratory, University of New South Wales Sydney NSW Australia
| | - Michael Fulham
- Department of Molecular Imaging, Royal Prince Alfred Hospital Camperdown NSW 2050 Australia
- Faculty of Engineering and Information Technologies, University of Sydney Sydney NSW 2006 Australia
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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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Barca C, Kiliaan AJ, Foray C, Wachsmuth L, Hermann S, Faber C, Schaefers M, Wiesmann M, Jacobs AH, Zinnhardt B. A longitudinal PET/MR imaging study of colony stimulating factor-1 receptor-mediated microglia depletion in experimental stroke. J Nucl Med 2021; 63:446-452. [PMID: 34168016 PMCID: PMC8978197 DOI: 10.2967/jnumed.121.262279] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/27/2021] [Indexed: 11/23/2022] Open
Abstract
Microglia-induced neuroinflammation after stroke contributes to the exacerbation of postischemic damage but also supports neurorestorative events. Longitudinal molecular imaging of microglia-targeted therapies will support the assessment of target engagement, therapy efficacy, and deciphering of the mode of action. We investigated the effects of chronic colony-stimulating factor 1 receptor (CSF-1R) inhibitor–mediated microglia depletion on translocator protein (TSPO)–dependent neuroinflammation and cerebrovascular parameters using PET/MRI. Methods: Forty C57BL/6 mice underwent a 30-min transient occlusion of the middle cerebral artery and were randomly assigned to either a control group or a group treated with CSF-1R inhibitor (PLX5622). Eight mice per group were used for N,N-diethyl-2-(2-(4-(2-18F-fluoroethoxy) phenyl)5,7dimethylpyrazolo[1, 5a]pyrimidin-3-yl)acetamide (18F-DPA-714) (TSPO) PET imaging on days 7, 14, 21, and 30 after ischemia and behavioral tests before and after surgery. An extra group of 8 mice underwent MRI, including T2-weighted (infarct), perfusion-weighted (cerebral blood flow), and diffusion-weighted (water diffusion, cellular density) sequences, on days 1, 3, 7, 14, 21, and 30. Ex vivo analysis (immunoreactivity, gene expression) was performed to characterize the inflammatory environment. Results: We demonstrated that long-term CSF-1R inhibition transiently decreased the TSPO PET signal within the infarct. Residual TSPO activity was partly due to a potentially resistant Iba-1–positive cell populations with low CSF-1R and transmembrane 119 expression. The decrease in selected pro- and antiinflammatory marker expression suggested an apparent global dampening of the neuroinflammatory response. Furthermore, the temporal changes in the MRI parameters highlighted treatment-induced effects on reperfusion and tissue homeostasis, associated with impaired motor function at late stages. Conclusion: Longitudinal TSPO PET/MRI allows the assessment of target engagement and optimization of drug efficiency. PLX5622 has promising immunomodulatory effects, and the optimal therapeutic time window for its application needs to be defined.
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Affiliation(s)
| | - Amanda J Kiliaan
- Department of Medical Imaging, Anatomy, Radboud University Medical Center, Netherlands
| | | | - Lydia Wachsmuth
- Clinic of Radiology, Translational Research Imaging Center (TRIC), University Hospital Munster, Germany
| | - Sven Hermann
- European Institute of Molecular Imaging, Germany
| | - Cornelius Faber
- Clinic of Radiology, Translational Research Imaging Center (TRIC), University Hospital Munster, Germany
| | | | - Maximilian Wiesmann
- Department of Medical Imaging, Anatomy, Radboud University Medical Center, Netherlands
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Patkar OL, Mohamed AZ, Narayanan A, Mardon K, Cowin G, Bhalla R, Stimson DHR, Kassiou M, Beecher K, Belmer A, Alvarez Cooper I, Morgan M, Hume DA, Irvine KM, Bartlett SE, Nasrallah F, Cumming P. A binge high sucrose diet provokes systemic and cerebral inflammation in rats without inducing obesity. Sci Rep 2021; 11:11252. [PMID: 34045616 PMCID: PMC8160215 DOI: 10.1038/s41598-021-90817-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/07/2021] [Indexed: 02/06/2023] Open
Abstract
While the dire cardiometabolic consequences of the hypercaloric modern 'Western' diet are well known, there is not much information on the health impact of a high sucrose diet not inducing weight gain. Here, we tested the hypothesis that rats reared with intermittent binge access to sucrose in addition to normal chow would develop an inflammatory response in brain. To test this hypothesis, we undertook serial PET/MRI scans with the TSPO ligand [18F]DPA714 in a group of (n=9) rats at baseline and again after voluntarily consuming 5% sucrose solution three days a week for three months. Compared to a control group fed with normal chow (n=9), the sucrose rats indeed showed widespread increases in the availability of cerebral binding sites for the microglial marker, despite normal weight gain compared to the control diet group. Subsequent immunofluorescence staining of the brains confirmed the PET findings, showing a widespread 20% increase in the abundance of IBA-1-positive microglia with characteristic 'semi-activated' morphology in the binge sucrose rats, which had 23% lower density of microglial endpoints and 25% lower mean process length compared to microglia in the control rats with ordinary feeding. GFAP immunofluorescence showed no difference in astroglial coverage in the sucrose rats, except for a slight reduction in hypothalamus. The binge sucrose diet-induced neuroinflammation was associated with a significant elevation of white blood cell counts. Taking these results together, we find that long-term intake of sucrose in a binge paradigm, similar in sucrose content to the contemporary Western diet, triggered a low-grade systemic and central inflammation in non-obese rats. The molecular mechanism of this phenomenon remains to be established.
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Affiliation(s)
- Omkar L Patkar
- Macrophage Biology Group, Mater Research, Translational Research Institute, Brisbane, QLD, Australia
- Department of Nuclear Medicine, Inselspital, Bern University, Bern, Switzerland
| | - Abdalla Z Mohamed
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Ashwin Narayanan
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Karine Mardon
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Gary Cowin
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Rajiv Bhalla
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Damion H R Stimson
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, NSW, 2006, Australia
| | - Kate Beecher
- Queensland University of Technology, Translational Research Institute, Brisbane, QLD, Australia
| | - Arnauld Belmer
- Queensland University of Technology, Translational Research Institute, Brisbane, QLD, Australia
| | - Ignatius Alvarez Cooper
- Queensland University of Technology, Translational Research Institute, Brisbane, QLD, Australia
| | - Michael Morgan
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - David A Hume
- Macrophage Biology Group, Mater Research, Translational Research Institute, Brisbane, QLD, Australia
| | - Katharine M Irvine
- Macrophage Biology Group, Mater Research, Translational Research Institute, Brisbane, QLD, Australia
| | - Selena E Bartlett
- Queensland University of Technology, Translational Research Institute, Brisbane, QLD, Australia
| | - Fatima Nasrallah
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Paul Cumming
- Department of Nuclear Medicine, Inselspital, Bern University, Bern, Switzerland.
- School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia.
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Cybulska KA, Bloemers V, Perk LR, Laverman P. Optimised GMP-compliant production of [ 18F]DPA-714 on the Trasis AllinOne module. EJNMMI Radiopharm Chem 2021; 6:20. [PMID: 34037896 PMCID: PMC8155128 DOI: 10.1186/s41181-021-00133-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/09/2021] [Indexed: 11/12/2022] Open
Abstract
Background The translocator protein 18 kDa is recognised as an important biomarker for neuroinflammation due to its soaring expression in microglia. This process is common for various neurological disorders. DPA-714 is a potent TSPO-specific ligand which found its use in Positron Emission Tomography following substitution of fluorine-19 with fluorine-18, a positron-emitting radionuclide. [18F]DPA-714 enables visualisation of inflammatory processes in vivo non-invasively. Radiolabelling of this tracer is well described in literature, including validation for clinical use. Here, we report significant enhancements to the process which resulted in the design of a fully GMP-compliant robust synthesis of [18F]DPA-714 on a popular cassette-based system, Trasis AllinOne, boosting reliability, throughput, and introducing a significant degree of simplicity. Results [18F]DPA-714 was synthesised using the classic nucleophilic aliphatic substitution on a good leaving group, tosylate, with [18F]fluoride using tetraethylammonium bicarbonate in acetonitrile at 100∘C. The process was fully automated on a Trasis AllinOne synthesiser using an in-house designed cassette and sequence. With a relatively small precursor load of 4 mg, [18F]DPA-714 was obtained with consistently high radiochemical yields of 55-71% (n=6) and molar activities of 117-350 GBq/µmol at end of synthesis. With a single production batch, starting with 31-42 GBq of [18F]fluoride, between 13-20 GBq of the tracer can be produced, enabling multi-centre studies. Conclusion To the best of our knowledge, the process presented herein is the most efficient [18F]DPA-714 synthesis, with advantageous GMP compliance. The use of a Trasis AllinOne synthesiser increases reliability and allows rapid training of production staff.
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Affiliation(s)
- Klaudia A Cybulska
- Radboud Translational Medicine B.V., Geert Grooteplein 21, Nijmegen, 6525 EZ, Netherlands. .,Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, Nijmegen, 6525 GA, Netherlands.
| | - Vera Bloemers
- Radboud Translational Medicine B.V., Geert Grooteplein 21, Nijmegen, 6525 EZ, Netherlands
| | - Lars R Perk
- Radboud Translational Medicine B.V., Geert Grooteplein 21, Nijmegen, 6525 EZ, Netherlands
| | - Peter Laverman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Geert Grooteplein 10, Nijmegen, 6525 GA, Netherlands
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Chaney AM, Lopez-Picon FR, Serrière S, Wang R, Bochicchio D, Webb SD, Vandesquille M, Harte MK, Georgiadou C, Lawrence C, Busson J, Vercouillie J, Tauber C, Buron F, Routier S, Reekie T, Snellman A, Kassiou M, Rokka J, Davies KE, Rinne JO, Salih DA, Edwards FA, Orton LD, Williams SR, Chalon S, Boutin H. Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study. Am J Cancer Res 2021; 11:6644-6667. [PMID: 34093845 PMCID: PMC8171096 DOI: 10.7150/thno.56059] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease. Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (Aβ) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed. Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG). Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD.
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38
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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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Mokrov GV, Deeva OA, Gudasheva TA. The Ligands of Translocator Protein: Design and Biological Properties. Curr Pharm Des 2021; 27:217-237. [PMID: 32881658 DOI: 10.2174/1381612826666200903122025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/15/2020] [Indexed: 11/22/2022]
Abstract
In 2020, it is already 43 years since Braestrup and Squires discovered 18 kDa translocator protein (TSPO), known until 2006 as "peripheral benzodiazepine receptor". During this time, the functions of this receptor, which is located on the outer membrane of mitochondria, were studied in detail. One of the key functions of TSPO is the transfer of cholesterol from the outer to the inner mitochondrial membrane, which is the limiting stage in the synthesis of neurosteroids. TSPO is also involved in the transport of porphyrins, mitochondrial respiration, the opening of mitochondrial pores, apoptosis and cell proliferation. This review presents current information on the structure of TSPO, the mechanism of its participation in neurosteroidogenesis, as well as endogenous and synthetic TSPO ligands. Particular emphasis is placed on the analysis of approaches to the design of synthetic ligands and their neuropsychotropic activity in vitro and in vivo. The presented review demonstrates the promise of constructing new neuropsychotropic drugs in the series of TSPO ligands.
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Affiliation(s)
- Grigory V Mokrov
- Zakusov Research Institute of Pharmacology, 125315, Moscow, Russian Federation
| | - Olga A Deeva
- Zakusov Research Institute of Pharmacology, 125315, Moscow, Russian Federation
| | - Tatiana A Gudasheva
- Zakusov Research Institute of Pharmacology, 125315, Moscow, Russian Federation
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40
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Zinnhardt B, Müther M, Roll W, Backhaus P, Jeibmann A, Foray C, Barca C, Döring C, Tavitian B, Dollé F, Weckesser M, Winkeler A, Hermann S, Wagner S, Wiendl H, Stummer W, Jacobs AH, Schäfers M, Grauer OM. TSPO imaging-guided characterization of the immunosuppressive myeloid tumor microenvironment in patients with malignant glioma. Neuro Oncol 2021; 22:1030-1043. [PMID: 32047908 DOI: 10.1093/neuonc/noaa023] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Tumor-associated microglia and macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) are potent immunosuppressors in the glioma tumor microenvironment (TME). Their infiltration is associated with tumor grade, progression, and therapy resistance. Specific tools for image-guided analysis of spatiotemporal changes in the immunosuppressive myeloid tumor compartments are missing. We aimed (i) to evaluate the role of fluorodeoxyglucose (18F)DPA-714* (translocator protein [TSPO]) PET-MRI in the assessment of the immunosuppressive TME in glioma patients, and (ii) to cross-correlate imaging findings with in-depth immunophenotyping. METHODS To characterize the glioma TME, a mixed collective of 9 glioma patients underwent [18F]DPA-714-PET-MRI in addition to [18F]fluoro-ethyl-tyrosine (FET)-PET-MRI. Image-guided biopsy samples were immunophenotyped by multiparametric flow cytometry and immunohistochemistry. In vitro autoradiography was performed for image validation and assessment of tracer binding specificity. RESULTS We found a strong relationship (r = 0.84, P = 0.009) between the [18F]DPA-714 uptake and the number and activation level of glioma-associated myeloid cells (GAMs). TSPO expression was mainly restricted to human leukocyte antigen D related-positive (HLA-DR+) activated GAMs, particularly to tumor-infiltrating HLA-DR+ MDSCs and TAMs. [18F]DPA-714-positive tissue volumes exceeded [18F]FET-positive volumes and showed a differential spatial distribution. CONCLUSION [18F]DPA-714-PET may be used to non-invasively image the glioma-associated immunosuppressive TME in vivo. This imaging paradigm may also help to characterize the heterogeneity of the glioma TME with respect to the degree of myeloid cell infiltration at various disease stages. [18F]DPA-714 may also facilitate the development of new image-guided therapies targeting the myeloid-derived TME.
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Affiliation(s)
- Bastian Zinnhardt
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,Immune Image-IMI Consortium, University Hospital Münster, Münster, Germany.,PET Imaging in Drug Design and Development (PET3D), University Hospital Münster, Münster, Germany
| | - Michael Müther
- Department of Neurosurgery, University Hospital Münster, Münster, Germany
| | - Wolfgang Roll
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Philipp Backhaus
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Astrid Jeibmann
- Institute of Neuroanatomy, University Hospital Münster, Münster, Germany
| | - Claudia Foray
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,PET Imaging in Drug Design and Development (PET3D), University Hospital Münster, Münster, Germany
| | - Cristina Barca
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,PET Imaging in Drug Design and Development (PET3D), University Hospital Münster, Münster, Germany
| | - Christian Döring
- European Institute for Molecular Imaging, University of Münster, Münster, Germany
| | - Bertrand Tavitian
- Inserm Unit 970, Paris Cardiovascular Research Center, Paris, France
| | - Frédéric Dollé
- Inserm Unit 1023, In Vivo Molecular Imaging Laboratory, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Matthias Weckesser
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Alexandra Winkeler
- Inserm Unit 1023, In Vivo Molecular Imaging Laboratory, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Sven Hermann
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Immune Image-IMI Consortium, University Hospital Münster, Münster, Germany
| | - Stefan Wagner
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Heinz Wiendl
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Walter Stummer
- Department of Neurosurgery, University Hospital Münster, Münster, Germany
| | - Andreas H Jacobs
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Immune Image-IMI Consortium, University Hospital Münster, Münster, Germany.,PET Imaging in Drug Design and Development (PET3D), University Hospital Münster, Münster, Germany.,Department of Geriatrics, Johanniter Hospital, Bonn, Germany
| | - Michael Schäfers
- European Institute for Molecular Imaging, University of Münster, Münster, Germany.,Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,Immune Image-IMI Consortium, University Hospital Münster, Münster, Germany
| | - Oliver M Grauer
- Immune Image-IMI Consortium, University Hospital Münster, Münster, Germany.,Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
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Poirion E, Tonietto M, Lejeune FX, Ricigliano VAG, Boudot de la Motte M, Benoit C, Bera G, Kuhnast B, Bottlaender M, Bodini B, Stankoff B. Structural and Clinical Correlates of a Periventricular Gradient of Neuroinflammation in Multiple Sclerosis. Neurology 2021; 96:e1865-e1875. [PMID: 33737372 PMCID: PMC8105971 DOI: 10.1212/wnl.0000000000011700] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 01/04/2021] [Indexed: 11/27/2022] Open
Abstract
Objectives To explore in vivo innate immune cell activation as a function of the distance from ventricular CSF in patients with multiple sclerosis (MS) using [18F]-DPA714 PET and to investigate its relationship with periventricular microstructural damage, evaluated by magnetization transfer ratio (MTR), and with trajectories of disability worsening. Methods Thirty-seven patients with MS and 19 healthy controls underwent MRI and [18F]-DPA714 TSPO dynamic PET, from which individual maps of voxels characterized by innate immune cell activation (DPA+) were generated. White matter (WM) was divided in 3-mm-thick concentric rings radiating from the ventricular surface toward the cortex, and the percentage of DPA+ voxels and mean MTR were extracted from each ring. Two-year trajectories of disability worsening were collected to identify patients with and without recent disability worsening. Results The percentage of DPA+ voxels was higher in patients compared to controls in the periventricular WM (p = 6.10e-6) and declined with increasing distance from ventricular surface, with a steeper gradient in patients compared to controls (p = 0.001). This gradient was found in both periventricular lesions and normal-appearing WM. In the total WM, it correlated with a gradient of microstructural tissue damage measured by MTR (rs = −0.65, p = 1.0e-3). Compared to clinically stable patients, patients with disability worsening were characterized by a higher percentage of DPA+ voxels in the periventricular normal-appearing WM (p = 0.025). Conclusions Our results demonstrate that in MS the innate immune cell activation predominates in periventricular regions and is associated with microstructural damage and disability worsening. This could result from the diffusion of proinflammatory CSF-derived factors into surrounding tissues.
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Affiliation(s)
- Emilie Poirion
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Matteo Tonietto
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - François-Xavier Lejeune
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Vito A G Ricigliano
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Marine Boudot de la Motte
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Charline Benoit
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Géraldine Bera
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Bertrand Kuhnast
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Michel Bottlaender
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Benedetta Bodini
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France
| | - Bruno Stankoff
- From the Sorbonne University (E.P., M.T., F.-X.L., V.A.G.R., M.B.d.l.M., C.B., G.B., B.B., B.S.), Paris Brain Institute; Imaging Department (E.P.), Foundation A. de Rothschild Hospital, Paris; Paris-Saclay University (M.T., B.K., M.B.), CEA, Orsay; and Assistance Publique des Hôpitaux de Paris (B.B., B.S.), France.
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Barca C, Wiesmann M, Calahorra J, Wachsmuth L, Döring C, Foray C, Heiradi A, Hermann S, Peinado MÁ, Siles E, Faber C, Schäfers M, Kiliaan AJ, Jacobs AH, Zinnhardt B. Impact of hydroxytyrosol on stroke: tracking therapy response on neuroinflammation and cerebrovascular parameters using PET-MR imaging and on functional outcomes. Theranostics 2021; 11:4030-4049. [PMID: 33754046 PMCID: PMC7977466 DOI: 10.7150/thno.48110] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/07/2021] [Indexed: 12/14/2022] Open
Abstract
Immune cells have been implicated in influencing stroke outcomes depending on their temporal dynamics, number, and spatial distribution after ischemia. Depending on their activation status, immune cells can have detrimental and beneficial properties on tissue outcome after stroke, highlighting the need to modulate inflammation towards beneficial and restorative immune responses. Novel dietary therapies may promote modulation of pro- and anti-inflammatory immune cell functions. Among the dietary interventions inspired by the Mediterranean diet, hydroxytyrosol (HT), the main phenolic component of the extra virgin olive oil (EVOO), has been suggested to have antioxidant and anti-inflammatory properties in vitro. However, immunomodulatory effects of HT have not yet been studied in vivo after stroke. The aim of this project is therefore to monitor the therapeutic effect of a HT-enriched diet in an experimental stroke model using non-invasive in vivo multimodal imaging, behavioural phenotyping and cross-correlation with ex vivo parameters. Methods: A total of N = 22 male C57BL/6 mice were fed with either a standard chow (n = 11) or a HT enriched diet (n = 11) for 35 days, following a 30 min transient middle cerebral artery occlusion (tMCAo). T2-weighted (lesion) and perfusion (cerebral blood flow)-/diffusion (cellular density)-weighted MR images were acquired at days 1, 3, 7, 14, 21 and 30 post ischemia. [18F]DPA-714 (TSPO, neuroinflammation marker) PET-CT scans were acquired at days 7, 14, 21 and 30 post ischemia. Infarct volume (mm3), cerebral blood flow (mL/100g/min), apparent diffusion coefficient (10-4·mm2/s) and percentage of injected tracer dose (%ID/mL) were assessed. Behavioural tests (grip test, rotarod, open field, pole test) were performed prior and after ischemia to access therapy effects on sensorimotor functions. Ex vivo analyses (IHC, IF, WB) were performed to quantify TSPO expression, immune cells including microglia/macrophages (Iba-1, F4/80), astrocytes (GFAP) and peripheral markers in serum such as thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) 35 days post ischemia. Additionally, gene expression of pro- and anti-inflammatory markers were assessed by rt-qPCR, including tspo, cd163, arg1, tnf and Il-1β. Results: No treatment effect was observed on temporal [18F]DPA-714 uptake within the ischemic and contralateral region (two-way RM ANOVA, p = 0.71). Quantification of the percentage of TSPO+ area by immunoreactivity indicated a slight 2-fold increase in TSPO expression within the infarct region in HT-fed mice at day 35 post ischemia (p = 0.011) correlating with a 2-3 fold increase in Iba-1+ cell population expressing CD163 as anti-inflammatory marker (R2 = 0.80). Most of the GFAP+ cells were TSPO-. Only few F4/80+ cells were observed at day 35 post ischemia in both groups. No significant treatment effect was observed on global ADC and CBF within the infarct and the contralateral region over time. Behavioural tests indicated improved strength of the forepaws at day 14 post ischemia (p = 0.031). Conclusion: An HT-enriched diet significantly increased the number of Iba-1+ microglia/macrophages in the post-ischemic area, inducing higher expression of anti-inflammatory markers while no clear-cut effect was observed. Also, HT did not affect recovery of the cerebrovascular parameters, including ADC and CBF. Altogether, our data indicated that a prolonged dietary intervention with HT, as a single component of the Mediterranean diet, induces molecular changes that may improve stroke outcomes. Therefore, we support the use of the Mediterranean diet as a multicomponent therapy approach after stroke.
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Zhang L, Hu K, Shao T, Hou L, Zhang S, Ye W, Josephson L, Meyer JH, Zhang MR, Vasdev N, Wang J, Xu H, Wang L, Liang SH. Recent developments on PET radiotracers for TSPO and their applications in neuroimaging. Acta Pharm Sin B 2021; 11:373-393. [PMID: 33643818 PMCID: PMC7893127 DOI: 10.1016/j.apsb.2020.08.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.
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Key Words
- AD, Alzheimer's disease
- ALS, amyotrophic lateral sclerosis
- AMPA, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid
- ANT, adenine nucleotide transporter
- Am, molar activities
- BBB, blood‒brain barrier
- BMSC, bone marrow stromal cells
- BP, binding potential
- BPND, non-displaceable binding potential
- BcTSPO, Bacillus cereus TSPO
- CBD, corticobasal degeneration
- CNS disorders
- CNS, central nervous system
- CRAC, cholesterol recognition amino acid consensus sequence
- DLB, Lewy body dementias
- EP, epilepsy
- FTD, frontotemporal dementia
- HAB, high-affinity binding
- HD, Huntington's disease
- HSE, herpes simplex encephalitis
- IMM, inner mitochondrial membrane
- KA, kainic acid
- LAB, low-affinity binding
- LPS, lipopolysaccharide
- MAB, mixed-affinity binding
- MAO-B, monoamine oxidase B
- MCI, mild cognitive impairment
- MDD, major depressive disorder
- MMSE, mini-mental state examination
- MRI, magnetic resonance imaging
- MS, multiple sclerosis
- MSA, multiple system atrophy
- Microglial activation
- NAA/Cr, N-acetylaspartate/creatine
- Neuroinflammation
- OCD, obsessive compulsive disorder
- OMM, outer mitochondrial membrane
- P2X7R, purinergic receptor P2X7
- PAP7, RIa-associated protein
- PBR, peripheral benzodiazepine receptor
- PCA, posterior cortical atrophy
- PD, Parkinson's disease
- PDD, PD dementia
- PET, positron emission tomography
- PKA, protein kinase A
- PRAX-1, PBR-associated protein 1
- PSP, progressive supranuclear palsy
- Positron emission tomography (PET)
- PpIX, protoporphyrin IX
- QA, quinolinic acid
- RCYs, radiochemical yields
- ROS, reactive oxygen species
- RRMS, relapsing remitting multiple sclerosis
- SA, specific activity
- SAH, subarachnoid hemorrhage
- SAR, structure–activity relationship
- SCIDY, spirocyclic iodonium ylide
- SNL, selective neuronal loss
- SNR, signal to noise ratio
- SUV, standard uptake volume
- SUVR, standard uptake volume ratio
- TBAH, tetrabutyl ammonium hydroxide
- TBI, traumatic brain injury
- TLE, temporal lobe epilepsy
- TSPO
- TSPO, translocator protein
- VDAC, voltage-dependent anion channel
- VT, distribution volume
- d.c. RCYs, decay-corrected radiochemical yields
- dMCAO, distal middle cerebral artery occlusion
- fP, plasma free fraction
- n.d.c. RCYs, non-decay-corrected radiochemical yields
- p.i., post-injection
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Liu Y, Wang L, Pan D, Li M, Li Y, Wang Y, Xu Y, Wang X, Yan J, Wu Q, Lu L, Yuan K, Yang M. PET evaluation of light-induced modulation of microglial activation and GLP-1R expression in depressive rats. Transl Psychiatry 2021; 11:26. [PMID: 33414373 PMCID: PMC7791059 DOI: 10.1038/s41398-020-01155-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/27/2020] [Accepted: 12/03/2020] [Indexed: 12/15/2022] Open
Abstract
Light therapy has been accepted as a promising therapeutic choice for depression. Positron emission tomography (PET) combined with specific radiotracers has great benefits for revealing pathogenesis and developing therapeutics. This study aimed to investigate the influences of light therapy on microglial activation and glucagon-like peptide-1 receptor (GLP-1R) expression in the brain of depressive rats using [18F]DPA-714 and [18F]exendin-4 PET. The results showed that chronic unpredictable mild stress (CUMS)-induced depressive rats had poorer performance in behavioral tests compared to normal rats (p < 0.05) and the depressive-like behavior could be ameliorated by light therapy. Besides, depressive rats had significantly higher [18F]DPA-714 uptake and lower [18F]FDG uptake compare to normal rats in 11 and 9 regions of interest (ROIs) of the brain, respectively (p < 0.05). After 5 weeks of light therapy, higher [18F]FDG and [18F]exendin-4 uptake was observed in most ROIs of light therapy-treated depressive rats compared to untreated depressive rats (p < 0.05) and no significant differences existed in [18F]DPA-714 uptake between the two groups. This study demonstrated that light therapy can ameliorate depressive-like behavior, improve glucose metabolism, and halt the decline of brain GLP-1R expression of depressive rats, but have no effects on microglial activation caused by CUMS. Besides, this study validated that [18F]DPA-714 and [18F]exendin-4 PET have the potential for noninvasive evaluation of microglial activation and GLP-1R expression in the brain of depression.
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Affiliation(s)
- Yu Liu
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China
| | - Lizhen Wang
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Donghui Pan
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Mingzhu Li
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Yaoqi Li
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Yan Wang
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Yuping Xu
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Xinyu Wang
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Junjie Yan
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Qiong Wu
- grid.412676.00000 0004 1799 0784NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063 Jiangsu China
| | - Lin Lu
- grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China ,grid.11135.370000 0001 2256 9319Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Peking University, 100191 Beijing, China
| | - Kai Yuan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Peking University, 100191, Beijing, China.
| | - Min Yang
- NHC Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, Jiangsu, China.
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Foray C, Valtorta S, Barca C, Winkeler A, Roll W, Müther M, Wagner S, Gardner ML, Hermann S, Schäfers M, Grauer OM, Moresco RM, Zinnhardt B, Jacobs AH. Imaging temozolomide-induced changes in the myeloid glioma microenvironment. Theranostics 2021; 11:2020-2033. [PMID: 33500706 PMCID: PMC7797694 DOI: 10.7150/thno.47269] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 09/21/2020] [Indexed: 12/26/2022] Open
Abstract
Rationale: The heterogeneous nature of gliomas makes the development and application of novel treatments challenging. In particular, infiltrating myeloid cells play a role in tumor progression and therapy resistance. Hence, a detailed understanding of the dynamic interplay of tumor cells and immune cells in vivo is necessary. To investigate the complex interaction between tumor progression and therapy-induced changes in the myeloid immune component of the tumor microenvironment, we used a combination of [18F]FET (amino acid metabolism) and [18F]DPA-714 (TSPO, GAMMs, tumor cells, astrocytes, endothelial cells) PET/MRI together with immune-phenotyping. The aim of the study was to monitor temozolomide (TMZ) treatment response and therapy-induced changes in the inflammatory tumor microenvironment (TME). Methods: Eighteen NMRInu/nu mice orthotopically implanted with Gli36dEGFR cells underwent MRI and PET/CT scans before and after treatment with TMZ or DMSO (vehicle). Tumor-to-background (striatum) uptake ratios were calculated and areas of unique tracer uptake (FET vs. DPA) were determined using an atlas-based volumetric approach. Results: TMZ therapy significantly modified the spatial distribution and uptake of both tracers. [18F]FET uptake was significantly reduced after therapy (-53 ± 84%) accompanied by a significant decrease of tumor volume (-17 ± 6%). In contrast, a significant increase (61 ± 33%) of [18F]DPA-714 uptake was detected by TSPO imaging in specific areas of the tumor. Immunohistochemistry (IHC) validated the reduction in tumor volumes and further revealed the presence of reactive TSPO-expressing glioma-associated microglia/macrophages (GAMMs) in the TME. Conclusion: We confirm the efficiency of [18F]FET-PET for monitoring TMZ-treatment response and demonstrate that in vivo TSPO-PET performed with [18F]DPA-714 can be used to identify specific reactive areas of myeloid cell infiltration in the TME.
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Danon JJ, Tregeagle DFL, Kassiou M. Adventures in Translocation: Studies of the Translocator Protein (TSPO) 18 kDa. Aust J Chem 2021. [DOI: 10.1071/ch21176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The 18 kDa translocator protein (TSPO) is an evolutionarily conserved transmembrane protein found embedded in the outer mitochondrial membrane. A secondary target for the benzodiazepine diazepam, TSPO has been a protein of interest for researchers for decades, particularly owing to its well-established links to inflammatory conditions in the central and peripheral nervous systems. It has become a key biomarker for assessing microglial activation using positron emission tomography (PET) imaging in patients with diseases ranging from atherosclerosis to Alzheimer’s disease. This Account describes research published by our group over the past 15 years surrounding the development of TSPO ligands and their use in probing the function of this high-value target.
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Brittain WDG, Lloyd CM, Cobb SL. Synthesis of complex unnatural fluorine-containing amino acids. J Fluor Chem 2020; 239:109630. [PMID: 33144742 PMCID: PMC7583769 DOI: 10.1016/j.jfluchem.2020.109630] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 01/01/2023]
Abstract
The area of fluorinated amino acid synthesis has seen rapid growth over the past decade. As reports of singly fluorinated natural amino acid derivatives have grown, researchers have turned their attention to develop methodology to access complex proteinogenic examples. A variety of reaction conditions have been employed in this area, exploiting new advances in the wider synthetic community such as photocatalysis and palladium cross-coupling. In addition, novel fluorinated functional groups have also been incorporated into amino acids, with SFX and perfluoro moieties now appearing with more frequency in the literature. This review focuses on synthetic methodology for accessing complex non-proteinogenic amino acids, along with amino acids containing multiple fluorine atoms such as CF3, SF5 and perfluoroaromatic groups.
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Affiliation(s)
| | - Carissa M Lloyd
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Steven L Cobb
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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Cipollina G, Davari Serej A, Di Nolfi G, Gazzano A, Marsala A, Spatafora MG, Peviani M. Heterogeneity of Neuroinflammatory Responses in Amyotrophic Lateral Sclerosis: A Challenge or an Opportunity? Int J Mol Sci 2020; 21:ijms21217923. [PMID: 33113845 PMCID: PMC7662281 DOI: 10.3390/ijms21217923] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 02/06/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a complex pathology: (i) the neurodegeneration is chronic and progressive; it starts focally in specific central nervous system (CNS) areas and spreads to different districts; (ii) multiple cell types further than motor neurons (i.e., glial/immune system cells) are actively involved in the disease; (iii) both neurosupportive and neurotoxic neuroinflammatory responses were identified. Microglia cells (a key player of neuroinflammation in the CNS) attracted great interest as potential target cell population that could be modulated to counteract disease progression, at least in preclinical ALS models. However, the heterogeneous/multifaceted microglia cell responses occurring in different CNS districts during the disease represent a hurdle for clinical translation of single-drug therapies. To address this issue, over the past ten years, several studies attempted to dissect the complexity of microglia responses in ALS. In this review, we shall summarize these results highlighting how the heterogeneous signature displayed by ALS microglia reflects not only the extent of neuronal demise in different regions of the CNS, but also variable engagement in the attempts to cope with the neuronal damage. We shall discuss novel avenues opened by the advent of single-cell and spatial transcriptomics technologies, underlining the potential for discovery of novel therapeutic targets, as well as more specific diagnostic/prognostic not-invasive markers of neuroinflammation.
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An update into the medicinal chemistry of translocator protein (TSPO) ligands. Eur J Med Chem 2020; 209:112924. [PMID: 33081988 DOI: 10.1016/j.ejmech.2020.112924] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 01/16/2023]
Abstract
The Translocator Protein 18 kDa (TSPO) has been discovered in 1977 as an alternative binding site for the benzodiazepine diazepam. It is an evolutionary well-conserved and tryptophan-rich 169-amino acids protein with five alpha helical transmembrane domains stretching the outer mitochondrial membrane, with the carboxyl-terminus in the cytosol and a short amino-terminus in the intermembrane space of mitochondrion. At this level, together with the voltage-dependent anion channel (VDAC) and the adenine nucleotide translocase (ANT), it forms the mitochondrial permeability transition pore (MPTP). TSPO expression is ubiquitary, with higher levels in steroid producing tissues; in the central nervous system, it is mainly expressed in glial cells and in neurons. TSPO is implicated in a variety of fundamental cellular processes including steroidogenesis, heme biosynthesis, mitochondrial respiration, mitochondrial membrane potential, cell proliferation and differentiation, cell life/death balance, oxidative stress. Altered TSPO expression has been found in some pathological conditions. In particular, high TSPO expression levels have been documented in cancer, neuroinflammation, and brain injury. Conversely, low TSPO expression levels have been evidenced in anxiety disorders. Therefore, TSPO is not only an interesting drug target for therapeutic purpose (anticonvulsant, anxiolytic, etc.), but also a valid diagnostic marker of related-diseases detectable by fluorescent or radiolabeled ligands. The aim of this report is to present an update of previous reviews dealing with the medicinal chemistry of TSPO and to highlight the most outstanding advances in the development of TSPO ligands as potential therapeutic or diagnostic tools, especially referring to the last five years.
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