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Trocka A, Kallingal A, Maciejewska N, Narajczyk M, Hromova A, Makowiec S. Synthesis and biological evaluation of novel 3,6- amide and thioamide substituted- 2,3,4,9-tetrahydro-1H-carbazoles for anti-cancer activity. Eur J Med Chem 2024; 277:116755. [PMID: 39173283 DOI: 10.1016/j.ejmech.2024.116755] [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: 06/13/2024] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 08/24/2024]
Abstract
Herein, we report the synthesis of new compounds with demonstrated anticancer properties based on the 2,3,4,9-tetrahydro-1H-carbazole scaffold. The Fischer indolization method was used to close the heterocyclic motif. The synthesis method's scope and limitations were thoroughly assessed through a series of experiments. Biological assays revealed that two thioamide compounds exhibited significant anticancer activity against MCF-7, HTC116, and A596 cell lines. Comprehensive in vitro profiling included evaluation of cell cytotoxicity, morphological alterations, colony formation and cell adhesion in 3D cultures, cell cycle analysis, DNA damage induction, impact on mitochondria, and apoptosis. Ex ovo studies further demonstrated these compounds' potential to inhibit angiogenic processes. Our results indicate that the newly developed compounds activate processes leading to DNA damage and disruption of mitochondrial function.
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Affiliation(s)
- Alicja Trocka
- Department of Organic Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland
| | - Anoop Kallingal
- Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland
| | - Natalia Maciejewska
- Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland
| | - Magdalena Narajczyk
- Bioimaging Laboratory, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
| | - Anna Hromova
- Department of Organic Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland
| | - Sławomir Makowiec
- Department of Organic Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233, Gdansk, Poland.
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Courault P, Zimmer L, Lancelot S. Toward Functional PET Imaging of the Spinal Cord. Semin Nucl Med 2024:S0001-2998(24)00066-7. [PMID: 39181820 DOI: 10.1053/j.semnuclmed.2024.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 07/25/2024] [Indexed: 08/27/2024]
Abstract
At present, spinal cord imaging primarily uses magnetic resonance imaging (MRI) or computed tomography (CT), but the greater sensitivity of positron emission tomography (PET) techniques and the development of new radiotracers are paving the way for a new approach. The substantial rise in publications on PET radiotracers for spinal cord exploration indicates a growing interest in the functional and molecular imaging of this organ. The present review aimed to provide an overview of the various radiotracers used in this indication, in preclinical and clinical settings. Firstly, we outline spinal cord anatomy and associated target pathologies. Secondly, we present the state-of-the-art of spinal cord imaging techniques used in clinical practice, with their respective strengths and limitations. Thirdly, we summarize the literature on radiotracers employed in functional PET imaging of the spinal cord. In conclusion, we propose criteria for an ideal radiotracer for molecular spinal cord imaging, emphasizing the relevance of multimodal hybrid cameras, and particularly the benefits of PET-MRI integration.
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Affiliation(s)
- Pierre Courault
- Lyon Neuroscience Research Center (CRNL), INSERM, CNRSx, Lyon, France; Hospices Civils de Lyon (HCL), Lyon, France; CERMEP-Imaging Platform, Lyon, France
| | - Luc Zimmer
- Lyon Neuroscience Research Center (CRNL), INSERM, CNRSx, Lyon, France; Hospices Civils de Lyon (HCL), Lyon, France; CERMEP-Imaging Platform, Lyon, France; National Institute for Nuclear Science and Technology (INSTN), CEA, Saclay, France.
| | - Sophie Lancelot
- Lyon Neuroscience Research Center (CRNL), INSERM, CNRSx, Lyon, France; Hospices Civils de Lyon (HCL), Lyon, France; CERMEP-Imaging Platform, Lyon, France
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Lee N, Choi JY, Ryu YH. The development status of PET radiotracers for evaluating neuroinflammation. Nucl Med Mol Imaging 2024; 58:160-176. [PMID: 38932754 PMCID: PMC11196502 DOI: 10.1007/s13139-023-00831-4] [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: 10/11/2023] [Revised: 11/16/2023] [Accepted: 12/05/2023] [Indexed: 06/28/2024] Open
Abstract
Neuroinflammation is associated with the pathophysiologies of neurodegenerative and psychiatric disorders. Evaluating neuroinflammation using positron emission tomography (PET) plays an important role in the early diagnosis and determination of proper treatment of brain diseases. To quantify neuroinflammatory responses in vivo, many PET tracers have been developed using translocator proteins, imidazole-2 binding site, cyclooxygenase, monoamine oxidase-B, adenosine, cannabinoid, purinergic P2X7, and CSF-1 receptors as biomarkers. In this review, we introduce the latest developments in PET tracers that can image neuroinflammation, focusing on clinical trials, and further consider their current implications.
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Affiliation(s)
- Namhun Lee
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812 Korea
| | - Jae Yong Choi
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 01812 Korea
- Radiological and Medico-Oncological Sciences, University of Science and Technology (UST), Seoul, Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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Kim D, Lee HW, Park SM, Lee JE, Lee SJ, Kim BS, Oh SJ, Moon BS, Yoon HJ. Application of TSPO-Specific Positron Emission Tomography Radiotracer as an Early Indicator of Acute Liver Failure Induced by Propacetamol, a Prodrug of Paracetamol. Int J Mol Sci 2024; 25:5942. [PMID: 38892130 PMCID: PMC11173123 DOI: 10.3390/ijms25115942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
Acetaminophen overdose is a leading cause of acute liver failure (ALF), and effective treatment depends on early prediction of disease progression. ALF diagnosis currently requires blood collection 24-72 h after APAP ingestion, necessitating repeated tests and hospitalization. Here, we assessed earlier ALF diagnosis using positron emission tomography (PET) imaging of translocator proteins (TSPOs), which are involved in molecular transport, oxidative stress, apoptosis, and energy metabolism, with the radiotracer [18F]GE180. We intraperitoneally administered propacetamol hydrochloride to male C57BL/6 mice to induce ALF. We performed in vivo PET/CT imaging 3 h later using the TSPO-specific radiotracer [18F]GE180 and quantitatively analyzed the PET images by determining the averaged standardized uptake value (SUVav) in the liver parenchyma. We assessed liver TSPO expression levels via real-time polymerase chain reaction, Western blotting, and immunohistochemistry. [18F]GE180 PET imaging 3 h after propacetamol administration (1500 mg/kg) significantly increased liver SUVav compared to controls (p = 0.001). Analyses showed a 10-fold and 4-fold increase in TSPO gene and protein expression, respectively, in the liver, 3 h after propacetamol induction compared to controls. [18F]GE180 PET visualized and quantified propacetamol-induced ALF through TSPO overexpression. These findings highlight TSPO PET's potential as a non-invasive imaging biomarker for early-stage ALF.
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Affiliation(s)
- Daehee Kim
- Department of Emergency Medicine, Incheon St. Mary’s Hospital, The Catholic University of Korea, Seoul 06591, Republic of Korea; (D.K.); (H.W.L.)
- Department of Emergency Medicine, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Hye Won Lee
- Department of Emergency Medicine, Incheon St. Mary’s Hospital, The Catholic University of Korea, Seoul 06591, Republic of Korea; (D.K.); (H.W.L.)
| | - Sun Mi Park
- Department of Nuclear Medicine, Ewha Womans University Seoul Hospital, Ewha Womans University College of Medicine, Seoul 07804, Republic of Korea; (S.M.P.); (B.S.K.)
| | - Ji Eun Lee
- Department of Nuclear Medicine, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul 07985, Republic of Korea;
| | - Sang Ju Lee
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea; (S.J.L.); (S.J.O.)
| | - Bom Sahn Kim
- Department of Nuclear Medicine, Ewha Womans University Seoul Hospital, Ewha Womans University College of Medicine, Seoul 07804, Republic of Korea; (S.M.P.); (B.S.K.)
| | - Seung Jun Oh
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea; (S.J.L.); (S.J.O.)
| | - Byung Seok Moon
- Department of Nuclear Medicine, Ewha Womans University Seoul Hospital, Ewha Womans University College of Medicine, Seoul 07804, Republic of Korea; (S.M.P.); (B.S.K.)
| | - Hai-Jeon Yoon
- Department of Nuclear Medicine, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul 07985, Republic of Korea;
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Zatcepin A, Kopczak A, Holzgreve A, Hein S, Schindler A, Duering M, Kaiser L, Lindner S, Schidlowski M, Bartenstein P, Albert N, Brendel M, Ziegler SI. Machine learning-based approach reveals essential features for simplified TSPO PET quantification in ischemic stroke patients. Z Med Phys 2024; 34:218-230. [PMID: 36682921 PMCID: PMC11156782 DOI: 10.1016/j.zemedi.2022.11.008] [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: 08/03/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Neuroinflammation evaluation after acute ischemic stroke is a promising option for selecting an appropriate post-stroke treatment strategy. To assess neuroinflammation in vivo, translocator protein PET (TSPO PET) can be used. However, the gold standard TSPO PET quantification method includes a 90 min scan and continuous arterial blood sampling, which is challenging to perform on a routine basis. In this work, we determine what information is required for a simplified quantification approach using a machine learning algorithm. MATERIALS AND METHODS We analyzed data from 18 patients with ischemic stroke who received 0-90 min [18F]GE-180 PET as well as T1-weigted (T1w), FLAIR, and arterial spin labeling (ASL) MRI scans. During PET scans, five manual venous blood samples at 5, 15, 30, 60, and 85 min post injection (p.i.) were drawn, and plasma activity concentration was measured. Total distribution volume (VT) was calculated using Logan plot with the full dynamic PET and an image-derived input function (IDIF) from the carotid arteries. IDIF was scaled by a calibration factor derived from all the measured plasma activity concentrations. The calculated VT values were used for training a random forest regressor. As input features for the model, we used three late PET frames (60-70, 70-80, and 80-90 min p.i.), the ASL image reflecting perfusion, the voxel coordinates, the lesion mask, and the five plasma activity concentrations. The algorithm was validated with the leave-one-out approach. To estimate the impact of the individual features on the algorithm's performance, we used Shapley Additive Explanations (SHAP). Having determined that the three late PET frames and the plasma activity concentrations were the most important features, we tested a simplified quantification approach consisting of dividing a late PET frame by a plasma activity concentration. All the combinations of frames/samples were compared by means of concordance correlation coefficient and Bland-Altman plots. RESULTS When using all the input features, the algorithm predicted VT values with high accuracy (87.8 ± 8.3%) for both lesion and non-lesion voxels. The SHAP values demonstrated high impact of the late PET frames (60-70, 70-80, and 80-90 min p.i.) and plasma activity concentrations on the VT prediction, while the influence of the ASL-derived perfusion, voxel coordinates, and the lesion mask was low. Among all the combinations of the late PET frames and plasma activity concentrations, the 70-80 min p.i. frame divided by the 30 min p.i. plasma sample produced the closest VT estimate in the ischemic lesion. CONCLUSION Reliable TSPO PET quantification is achievable by using a single late PET frame divided by a late blood sample activity concentration.
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Affiliation(s)
- Artem Zatcepin
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.
| | - Anna Kopczak
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sandra Hein
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Andreas Schindler
- Department of Neuroradiology, University Hospital, LMU Munich, Munich, Germany
| | - Marco Duering
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany; Medical Image Analysis Center (MIAC) & Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Martin Schidlowski
- Department of Epileptology, University Hospital Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Nathalie Albert
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sibylle I Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
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Yu M, Zhao S. Functional role of translocator protein and its ligands in ocular diseases (Review). Mol Med Rep 2024; 29:33. [PMID: 38186312 PMCID: PMC10804439 DOI: 10.3892/mmr.2024.13157] [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: 08/17/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
The 18 kDa translocator protein (TSPO) is an essential outer mitochondrial membrane protein that is responsible for mitochondrial transport, maintenance of mitochondrial homeostasis and normal physiological cell function. The role of TSPO in the pathogenesis of ocular diseases is a growing area of interest. More notably, TSPO exerts positive effects in regulating various pathophysiological processes, such as the inflammatory response, oxidative stress, steroid synthesis and modulation of microglial function, in combination with a variety of specific ligands such as 1‑(2‑chlorophenyl‑N‑methylpropyl)‑3‑isoquinolinecarboxamide, 4'‑chlorodiazepam and XBD173. In the present review, the expression of TSPO in ocular tissues and the functional role of TSPO and its ligands in diverse ocular diseases was discussed.
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Affiliation(s)
- Mingyi Yu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
| | - Shaozhen Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
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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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Leńska-Mieciek M, Madetko-Alster N, Alster P, Królicki L, Fiszer U, Koziorowski D. Inflammation in multiple system atrophy. Front Immunol 2023; 14:1214677. [PMID: 37426656 PMCID: PMC10327640 DOI: 10.3389/fimmu.2023.1214677] [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: 04/30/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Misfolding protein aggregation inside or outside cells is the major pathological hallmark of several neurodegenerative diseases. Among proteinopathies are neurodegenerative diseases with atypical Parkinsonism and an accumulation of insoluble fibrillary alpha-synuclein (synucleinopathies) or hyperphosphorylated tau protein fragments (tauopathies). As there are no therapies available to slow or halt the progression of these disea ses, targeting the inflammatory process is a promising approach. The inflammatory biomarkers could also help in the differential diagnosis of Parkinsonian syndromes. Here, we review inflammation's role in multiple systems atrophy pathogenesis, diagnosis, and treatment.
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Affiliation(s)
- Marta Leńska-Mieciek
- Department of Neurology and Epileptology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | | | - Piotr Alster
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Leszek Królicki
- Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Urszula Fiszer
- Department of Neurology and Epileptology, Centre of Postgraduate Medical Education, Warsaw, Poland
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Kim SJW, Lupo JM, Chen Y, Pampaloni MH, VanBrocklin HF, Narvid J, Kim H, Seo Y. A feasibility study for quantitative assessment of cerebrovascular malformations using flutriciclamide ([18F]GE-180) PET/MRI. Front Med (Lausanne) 2023; 10:1091463. [PMID: 37089589 PMCID: PMC10116613 DOI: 10.3389/fmed.2023.1091463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/14/2023] [Indexed: 04/08/2023] Open
Abstract
AimNeuroinflammation plays a key role in both the pathogenesis and the progression of cerebral cavernous malformations (CCM). Flutriciclamide ([18F]GE-180) is a translocator protein (TSPO) targeting positron emission tomography (PET) tracer, developed for imaging neuroinflammation. The objectives of this study were to describe characteristics of flutriciclamide uptake in different brain tissue regions in CCM patients compared to controls, and to evaluate flutriciclamide uptake and iron deposition within CCM lesions.Materials and methodsFive patients with CCM and six controls underwent a 60 or 90 min continuous PET/MRI scan following 315 ± 68.9 MBq flutriciclamide administration. Standardized uptake value (SUV) and standardized uptake value ratio (SUVr) were obtained using the striatum as a pseudo-reference. Quantitative susceptibility maps (QSM) were used to define the location of the vascular malformation and calculate the amount of iron deposition in each lesion.ResultsIncreased flutriciclamide uptake was observed in all CCM lesions. The temporal pole demonstrated the highest radiotracer uptake; the paracentral lobule, cuneus and hippocampus exhibited moderate uptake; while the striatum had the lowest uptake, with average SUVs of 0.66, 0.55, 0.63, 0.55, and 0.33 for patient with CCM and 0.57, 0.50, 0.48, 0.42, and 0.32 for controls, respectively. Regional SUVr showed similar trends. The average SUV and QSM values in CCM lesions were 0.58 ± 0.23 g/ml and 0.30 ± 0.10 ppm. SUVs and QSM were positively correlated in CCM lesions (r = 0.53, p = 0.03).ConclusionThe distribution of flutriciclamide ([18F]GE-180) in the human brain and CCM lesions demonstrated the potential of this TSPO PET tracer as a marker of neuroinflammation that may be relevant for characterizing CCM disease progression along with QSM.
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Affiliation(s)
- Sally Ji Who Kim
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- *Correspondence: Sally Ji Who Kim,
| | - Janine M. Lupo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Yicheng Chen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Miguel H. Pampaloni
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Henry F. VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Jared Narvid
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Helen Kim
- Department of Anesthesia and Perioperative Care, Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, CA, United States
| | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
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Conte M, De Feo MS, Corica F, Gorica J, Sidrak MMA, De Cristofaro F, Filippi L, Ricci M, De Vincentis G, Frantellizzi V. A Systematic Review on Dementia and Translocator Protein (TSPO): When Nuclear Medicine Highlights an Underlying Expression. Biomolecules 2023; 13:biom13040598. [PMID: 37189346 DOI: 10.3390/biom13040598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
Background: Translocator protein (TSPO) is a neuroinflammation hallmark. Different TSPO affinity compounds have been produced and over time, the techniques of radiolabeling have been refined. The aim of this systematic review is to summarize the development of new radiotracers for dementia and neuroinflammation imaging. Methods: An online search of the literature was conducted in the PubMed, Scopus, Medline, Cochrane Library, and Web of Science databases, selecting published studies from January 2004 to December 2022. The accepted studies considered the synthesis of TSPO tracers for nuclear medicine imaging in dementia and neuroinflammation. Results: A total of 50 articles was identified. Twelve papers were selected from the included studies’ bibliographies and 34 were excluded. Thus, 28 articles were ultimately selected for quality assessment. Conclusion: Huge efforts in developing specific and stable tracers for PET/SPECT imaging have been made. The long half-life of 18F makes this isotope a preferable choice to 11C. An emerging limitation to this however is that neuroinflammation involves all of the brain which inhibits the possibility of detecting a slight inflammation status change in patients. A partial solution to this is using the cerebellum as a reference region and developing higher TSPO affinity tracers. Moreover, it is necessary to consider the presence of distomers and racemic compounds interfering with pharmacological tracers’ effects and increasing the noise ratio in images.
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TSPO PET signal using [ 18F]GE180 is associated with survival in recurrent gliomas. Eur J Nucl Med Mol Imaging 2023; 50:859-869. [PMID: 36329288 PMCID: PMC9852133 DOI: 10.1007/s00259-022-06006-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE Glioma patients, especially recurrent glioma, suffer from a poor prognosis. While advances to classify glioma on a molecular level improved prognostication at initial diagnosis, markers to prognosticate survival in the recurrent situation are still needed. As 18 kDa translocator protein (TSPO) was previously reported to be associated with aggressive histopathological glioma features, we correlated the TSPO positron emission tomography (PET) signal using [18F]GE180 in a large cohort of recurrent glioma patients with their clinical outcome. METHODS In patients with [18F]GE180 PET at glioma recurrence, [18F]GE180 PET parameters (e.g., SUVmax) as well as other imaging features (e.g., MRI volume, [18F]FET PET parameters when available) were evaluated together with patient characteristics (age, sex, Karnofsky-Performance score) and neuropathological features (e.g. WHO 2021 grade, IDH-mutation status). Uni- and multivariate Cox regression and Kaplan-Meier survival analyses were performed to identify prognostic factors for post-recurrence survival (PRS) and time to treatment failure (TTF). RESULTS Eighty-eight consecutive patients were evaluated. TSPO tracer uptake correlated with tumor grade at recurrence (p < 0.05), with no significant differences in IDH-wild-type versus IDH-mutant tumors. Within the subgroup of IDH-mutant glioma (n = 46), patients with low SUVmax (median split, ≤ 1.60) had a significantly longer PRS (median 41.6 vs. 25.3 months, p = 0.031) and TTF (32.2 vs 8.7 months, p = 0.001). Also among IDH-wild-type glioblastoma (n = 42), patients with low SUVmax (≤ 1.89) had a significantly longer PRS (median not reached vs 8.2 months, p = 0.002). SUVmax remained an independent prognostic factor for PRS in the multivariate analysis including CNS WHO 2021 grade, IDH status, and age. Tumor volume defined by [18F]FET PET or contrast-enhanced MRI correlated weakly with TSPO tracer uptake. Treatment regimen did not differ among the median split subgroups. CONCLUSION Our data suggest that TSPO PET using [18F]GE180 can help to prognosticate recurrent glioma patients even among homogeneous molecular subgroups and may therefore serve as valuable non-invasive biomarker for individualized patient management.
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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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13
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Chandekar KR, Satapathy S, Singh H, Bhattacharya A. Molecular imaging as a tool for evaluation of COVID-19 sequelae – A review of literature. World J Radiol 2022; 14:194-208. [PMID: 36160629 PMCID: PMC9350609 DOI: 10.4329/wjr.v14.i7.194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/17/2022] [Accepted: 07/11/2022] [Indexed: 02/06/2023] Open
Abstract
Coronavirus disease 2019 (COVID-19) is caused by the novel viral pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 primarily involves the lungs. Nucleic acid testing based on reverse-transcription polymerase chain reaction of respiratory samples is the current gold standard for the diagnosis of SARS-CoV-2 infection. Imaging modalities have an established role in triaging, diagnosis, evaluation of disease severity, monitoring disease progression, extra-pulmonary involvement, and complications. As our understanding of the disease improves, there has been substantial evidence to highlight its potential for multi-systemic involvement and development of long-term sequelae. Molecular imaging techniques are highly sensitive, allowing non-invasive visualization of physiological or pathological processes at a cellular or molecular level with potential for detection of functional changes earlier than conventional radiological imaging. The purpose of this review article is to highlight the evolving role of molecular imaging in evaluation of COVID-19 sequelae. Though not ideal for diagnosis, the various modalities of molecular imaging play an important role in assessing pulmonary and extra-pulmonary sequelae of COVID-19. Perfusion imaging using single photon emission computed tomography fused with computed tomography (CT) can be utilized as a first-line imaging modality for COVID-19 related pulmonary embolism. 18F-fluorodeoxyglucose positron emission tomography (PET)/CT is a sensitive tool to detect multi-systemic inflammation, including myocardial and vascular inflammation. PET in conjunction with magnetic resonance imaging helps in better characterization of neurological sequelae of COVID-19. Despite the fact that the majority of published literature is retrospective in nature with limited sample sizes, it is clear that molecular imaging provides additional valuable information (complimentary to anatomical imaging) with semi-quantitative or quantitative parameters to define inflammatory burden and can be used to guide therapeutic strategies and assess response. However, widespread clinical applicability remains a challenge owing to longer image acquisition times and the need for adoption of infection control protocols.
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Affiliation(s)
- Kunal R Chandekar
- Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Swayamjeet Satapathy
- Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Harmandeep Singh
- Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Anish Bhattacharya
- Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
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14
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Neuroinflammation in Low-Level PM2.5-Exposed Rats Illustrated by PET via an Improved Automated Produced [18F]FEPPA: A Feasibility Study. Mol Imaging 2022; 2022:1076444. [PMID: 35903248 PMCID: PMC9328187 DOI: 10.1155/2022/1076444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/10/2022] [Accepted: 05/18/2022] [Indexed: 11/26/2022] Open
Abstract
Background [18F]FEPPA is a potent TSPO imaging agent that has been found to be a potential tracer for imaging neuroinflammation. In order to fulfill the demand of this tracer for preclinical and clinical studies, we have developed a one-pot automated synthesis with simplified HPLC purification of this tracer, which was then used for PET imaging of neuroinflammation in fine particulate matter- (PM2.5-) exposed rats. Results Using this automated synthesis method, the RCY of the [18F]FEPPA was 38 ± 4% (n = 17, EOB) in a synthesis time of 83 ± 8 min from EOB. The radiochemical purity and molar activities were greater than 99% and 209 ± 138 GBq/μmol (EOS, n = 15), respectively. The quality of the [18F]FEPPA synthesized by this method met the U.S. Pharmacopoeia (USP) criteria. The stability test showed that the [18F]FEPPA was stable at 21 ± 2°C for up to 4 hr after the end of synthesis (EOS). Moreover, microPET imaging showed that increased tracer activity of [18F]FEPPA in the brain of PM2.5-exposed rats (n = 6) were higher than that of normal controls (n = 6) and regional-specific. Conclusions Using the improved semipreparative HPLC purification, [18F]FEPPA has been produced in high quantity, high quality, and high reproducibility and, for the first time, used for PET imaging the effects of PM2.5 in the rat brain. It is ready to be used for imaging inflammation in various clinical or preclinical studies, especially for nearby PET centers without cyclotrons.
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15
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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: 15] [Impact Index Per Article: 7.5] [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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Chen B, Marquez-Nostra B, Belitzky E, Toyonaga T, Tong J, Huang Y, Cai Z. PET Imaging in Animal Models of Alzheimer’s Disease. Front Neurosci 2022; 16:872509. [PMID: 35685772 PMCID: PMC9171374 DOI: 10.3389/fnins.2022.872509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
The successful development and translation of PET imaging agents targeting β-amyloid plaques and hyperphosphorylated tau tangles have allowed for in vivo detection of these hallmarks of Alzheimer’s disease (AD) antemortem. Amyloid and tau PET have been incorporated into the A/T/N scheme for AD characterization and have become an integral part of ongoing clinical trials to screen patients for enrollment, prove drug action mechanisms, and monitor therapeutic effects. Meanwhile, preclinical PET imaging in animal models of AD can provide supportive information for mechanistic studies. With the recent advancement of gene editing technologies and AD animal model development, preclinical PET imaging in AD models will further facilitate our understanding of AD pathogenesis/progression and the development of novel treatments. In this study, we review the current state-of-the-art in preclinical PET imaging using animal models of AD and suggest future research directions.
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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: 19] [Impact Index Per Article: 9.5] [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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18
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Holzgreve A, Pötter D, Brendel M, Orth M, Weidner L, Gold L, Kirchner MA, Bartos LM, Unterrainer LM, Unterrainer M, Steiger K, von Baumgarten L, Niyazi M, Belka C, Bartenstein P, Riemenschneider MJ, Lauber K, Albert NL. Longitudinal [ 18F]GE-180 PET Imaging Facilitates In Vivo Monitoring of TSPO Expression in the GL261 Glioblastoma Mouse Model. Biomedicines 2022; 10:biomedicines10040738. [PMID: 35453488 PMCID: PMC9030822 DOI: 10.3390/biomedicines10040738] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 02/01/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) is increasingly recognized as an interesting target for the imaging of glioblastoma (GBM). Here, we investigated TSPO PET imaging and autoradiography in the frequently used GL261 glioblastoma mouse model and aimed to generate insights into the temporal evolution of TSPO radioligand uptake in glioblastoma in a preclinical setting. We performed a longitudinal [18F]GE-180 PET imaging study from day 4 to 14 post inoculation in the orthotopic syngeneic GL261 GBM mouse model (n = 21 GBM mice, n = 3 sham mice). Contrast-enhanced computed tomography (CT) was performed at the day of the final PET scan (±1 day). [18F]GE-180 autoradiography was performed on day 7, 11 and 14 (ex vivo: n = 13 GBM mice, n = 1 sham mouse; in vitro: n = 21 GBM mice; n = 2 sham mice). Brain sections were also used for hematoxylin and eosin (H&E) staining and TSPO immunohistochemistry. [18F]GE-180 uptake in PET was elevated at the site of inoculation in GBM mice as compared to sham mice at day 11 and later (at day 14, TBRmax +27% compared to sham mice, p = 0.001). In GBM mice, [18F]GE-180 uptake continuously increased over time, e.g., at day 11, mean TBRmax +16% compared to day 4, p = 0.011. [18F]GE-180 uptake as depicted by PET was in all mice co-localized with contrast-enhancement in CT and tissue-based findings. [18F]GE-180 ex vivo and in vitro autoradiography showed highly congruent tracer distribution (r = 0.99, n = 13, p < 0.001). In conclusion, [18F]GE-180 PET imaging facilitates non-invasive in vivo monitoring of TSPO expression in the GL261 GBM mouse model. [18F]GE-180 in vitro autoradiography is a convenient surrogate for ex vivo autoradiography, allowing for straightforward identification of suitable models and scan time-points on previously generated tissue sections.
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Affiliation(s)
- Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Dennis Pötter
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Michael Orth
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (M.O.); (M.N.); (C.B.); (K.L.)
| | - Lorraine Weidner
- Department of Neuropathology, Regensburg University Hospital, 93053 Regensburg, Germany; (L.W.); (M.J.R.)
| | - Lukas Gold
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Maximilian A. Kirchner
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Laura M. Bartos
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Lena M. Unterrainer
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
| | - Marcus Unterrainer
- Department of Radiology, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany;
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
| | - Katja Steiger
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
- Institute of Pathology, TUM School of Medicine, Technical University of Munich, 81675 Munich, Germany
| | - Louisa von Baumgarten
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
- Department of Neurosurgery, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (M.O.); (M.N.); (C.B.); (K.L.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (M.O.); (M.N.); (C.B.); (K.L.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
| | - Markus J. Riemenschneider
- Department of Neuropathology, Regensburg University Hospital, 93053 Regensburg, Germany; (L.W.); (M.J.R.)
| | - Kirsten Lauber
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (M.O.); (M.N.); (C.B.); (K.L.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
| | - Nathalie L. Albert
- Department of Nuclear Medicine, University Hospital, Ludwig Maximilian University of Munich (LMU Munich), 81377 Munich, Germany; (A.H.); (D.P.); (M.B.); (L.G.); (M.A.K.); (L.M.B.); (L.M.U.); (P.B.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (K.S.); (L.v.B.)
- Correspondence:
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Zatcepin A, Heindl S, Schillinger U, Kaiser L, Lindner S, Bartenstein P, Kopczak A, Liesz A, Brendel M, Ziegler SI. Reduced Acquisition Time [18F]GE-180 PET Scanning Protocol Replaces Gold-Standard Dynamic Acquisition in a Mouse Ischemic Stroke Model. Front Med (Lausanne) 2022; 9:830020. [PMID: 35223925 PMCID: PMC8866959 DOI: 10.3389/fmed.2022.830020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/17/2022] [Indexed: 02/04/2023] Open
Abstract
AimUnderstanding neuroinflammation after acute ischemic stroke is a crucial step on the way to an individualized post-stroke treatment. Microglia activation, an essential part of neuroinflammation, can be assessed using [18F]GE-180 18 kDa translocator protein positron emission tomography (TSPO-PET). However, the commonly used 60–90 min post-injection (p.i.) time window was not yet proven to be suitable for post-stroke neuroinflammation assessment. In this study, we compare semi-quantitative estimates derived from late time frames to quantitative estimates calculated using a full 0–90 min dynamic scan in a mouse photothrombotic stroke (PT) model.Materials and MethodsSix mice after PT and six sham mice were included in the study. For a half of the mice, we acquired four serial 0–90 min scans per mouse (analysis cohort) and calculated standardized uptake value ratios (SUVRs; cerebellar reference) for the PT volume of interest (VOI) in five late 10 min time frames as well as distribution volume ratios (DVRs) for the same VOI. We compared late static 10 min SUVRs and the 60–90 min time frame of the analysis cohort to the corresponding DVRs by linear fitting. The other half of the animals received a static 60–90 min scan and was used as a validation cohort. We extrapolated DVRs by using the static 60–90 min p.i. time window, which were compared to the DVRs of the analysis cohort.ResultsWe found high linear correlations between SUVRs and DVRs in the analysis cohort for all studied 10 min time frames, while the fits of the 60–70, 70–80, and 80–90 min p.i. time frames were the ones closest to the line of identity. For the 60–90 min time window, we observed an excellent linear correlation between SUVR and DVR regardless of the phenotype (PT vs. sham). The extrapolated DVRs of the validation cohort were not significantly different from the DVRs of the analysis group.ConclusionSimplified quantification by a reference tissue ratio of the late 60–90 min p.i. [18F]GE-180 PET image can replace full quantification of a dynamic scan for assessment of microglial activation in the mouse PT model.
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Affiliation(s)
- Artem Zatcepin
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
- *Correspondence: Artem Zatcepin
| | - Steffanie Heindl
- Institute for Stroke and Dementia Research, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Institute for Stroke and Dementia Research, Munich, Germany
| | - Ulrike Schillinger
- Institute for Stroke and Dementia Research, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Institute for Stroke and Dementia Research, Munich, Germany
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Anna Kopczak
- Institute for Stroke and Dementia Research, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Institute for Stroke and Dementia Research, Munich, Germany
| | - Arthur Liesz
- Institute for Stroke and Dementia Research, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Institute for Stroke and Dementia Research, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sibylle I. Ziegler
- Department of Nuclear Medicine, University Hospital of Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
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20
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Vainio SK, Dickens AM, Matilainen M, López-Picón FR, Aarnio R, Eskola O, Solin O, Anthony DC, Rinne JO, Airas L, Haaparanta-Solin M. Dimethyl fumarate decreases short-term but not long-term inflammation in a focal EAE model of neuroinflammation. EJNMMI Res 2022; 12:6. [PMID: 35107664 PMCID: PMC8811048 DOI: 10.1186/s13550-022-00878-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 12/27/2021] [Indexed: 12/16/2022] Open
Abstract
Background Dimethyl fumarate (DMF) is an oral immunomodulatory drug used in the treatment of autoimmune diseases. Here, we sought to study whether the effect of DMF can be detected using positron emission tomography (PET) targeting the 18-kDa translocator protein (TSPO) in the focal delayed-type hypersensitivity rat model of multiple sclerosis (fDTH-EAE). The rats were treated orally twice daily from lesion activation (day 0) with either vehicle (tap water with 0.08% Methocel, 200 µL; control group n = 4 (3 after week four)) or 15 mg/kg DMF (n = 4) in 0.08% aqueous Methocel (200 µL) for 8 weeks. The animals were imaged by PET using the TSPO tracer [18F]GE-180 in weeks 0, 1, 2, 4, 8, and 18 following lesion activation, and the non-displaceable binding potential (BPND) was calculated. Immunohistochemical staining for Iba1, CD4, and CD8 was performed in week 18, and in separate cohorts of animals, following 2 or 4 weeks of treatment. Results Using the fDTH-EAE model, DMF reduced the [18F]GE-180 BPND in the DMF-treated animals compared to control animals after 1 week of treatment (two-tailed unpaired t test, p = 0.031), but not in weeks 2, 4, 8, or 18 when imaged in vivo by PET. Immunostaining for Iba1 showed that DMF had no effect on the perilesional volume or the core lesion volume after 2 or 4 weeks of treatment, or at 18 weeks. However, the optical density (OD) measurements of CD4+ staining showed reduced OD in the lesions of the treated rats. Conclusions DMF reduced the microglial activation in the fDTH-EAE model after 1 week of treatment, as detected by PET imaging of the TSPO ligand [18F]GE-180. However, over an extended time course, reduced microglial activation was not observed using [18F]GE-180 or by immunohistochemistry for Iba1+ microglia/macrophages. Additionally, DMF did affect the infiltration of CD4+ and CD8+ T-lymphocytes at the fDTH-EAE lesion. Supplementary Information The online version contains supplementary material available at 10.1186/s13550-022-00878-y. In a focal rat DTH-EAE model of neuroinflammation, dimethyl fumarate decreases the uptake of TSPO PET tracer [18F]GE-180 in the short term. Long-term [18F]GE-180 follow-up did not indicate a treatment effect. Decreased neuroinflammation, CD4+ T cell infiltration, and CD8+ T cell infiltration were detected using immunohistochemistry.
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Affiliation(s)
- S K Vainio
- Turku PET Centre, Preclinical PET Imaging, Preclinical Imaging Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland. .,MediCity Research Laboratory, University of Turku, Turku, Finland.
| | - A M Dickens
- Department of Chemistry, University of Turku, Turku, Finland.,Turku Bioscience, Turku, Finland
| | - M Matilainen
- Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.,Turku PET Centre, University of Turku, Turku, Finland
| | - F R López-Picón
- Turku PET Centre, Preclinical PET Imaging, Preclinical Imaging Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - R Aarnio
- MediCity Research Laboratory, University of Turku, Turku, Finland.,Turku PET Centre, University of Turku, Turku, Finland
| | - O Eskola
- Turku PET Centre, Radiopharmaceutical Chemistry Laboratory, University of Turku, Turku, Finland
| | - O Solin
- Accelerator Laboratory, Åbo Akademi University, Turku, Finland.,Turku PET Centre, Radiopharmaceutical Chemistry Laboratory, University of Turku, Turku, Finland
| | - D C Anthony
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - J O Rinne
- Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland.,Turku PET Centre, University of Turku, Turku, Finland
| | - L Airas
- Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland.,Department of Clinical Medicine, University of Turku, Turku, Finland
| | - M Haaparanta-Solin
- Turku PET Centre, Preclinical PET Imaging, Preclinical Imaging Laboratory, University of Turku, Tykistökatu 6 A, 20520, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
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21
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Kaiser L, Holzgreve A, Quach S, Ingrisch M, Unterrainer M, Dekorsy FJ, Lindner S, Ruf V, Brosch-Lenz J, Delker A, Böning G, Suchorska B, Niyazi M, Wetzel CH, Riemenschneider MJ, Stöcklein S, Brendel M, Rupprecht R, Thon N, von Baumgarten L, Tonn JC, Bartenstein P, Ziegler S, Albert NL. Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas. Cancers (Basel) 2021; 14:cancers14010053. [PMID: 35008218 PMCID: PMC8750092 DOI: 10.3390/cancers14010053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 01/14/2023] Open
Abstract
Simple Summary Radiotracers targeting the translocator protein (TSPO) have recently gained substantial interest, since TSPO is overexpressed in malignant gliomas, where it correlates inversely with patient’s survival. The high-affinity TSPO PET ligand [18F]GE180 was found to depict tumor areas with a remarkably high contrast and has been shown to provide non-invasive information on histological tumor grades. Yet, its significance was questioned with the argument, that the high contrast may solely arise from nonspecific accumulation in tissue supplied by leaky vessels. This study aimed to address this question by providing a detailed evaluation of spatial associations between TSPO and amino acid PET with relative contrast enhancement in T1-weighted MRI. The results show that [18F]GE180 contrast does not reflect a disrupted blood–brain barrier (BBB) only and that multi-modal imaging generates complementary information, which may better depict spatial heterogeneity of tumor biology and may be used to individualize the therapy for each patient. Abstract In this study, dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (tumor-to-background ratio, TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.
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Affiliation(s)
- Lena Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- Correspondence:
| | - Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Stefanie Quach
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Michael Ingrisch
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Franziska J. Dekorsy
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Viktoria Ruf
- Center for Neuropathology and Prion Research, LMU Munich, 81377 Munich, Germany; (V.R.); (R.R.)
| | - Julia Brosch-Lenz
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Astrid Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | | | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, 81377 Munich, Germany;
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Christian H. Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany;
| | | | - Sophia Stöcklein
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany;
| | - Niklas Thon
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Louisa von Baumgarten
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Jörg-Christian Tonn
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Nathalie L. Albert
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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22
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Dirks M, Buchert R, Wirries AK, Pflugrad H, Grosse GM, Petrusch C, Schütze C, Wilke F, Mamach M, Hamann L, Langer LBN, Ding XQ, Barg-Hock H, Klempnauer J, Wetzel CH, Lukacevic M, Janssen E, Kessler M, Bengel FM, Geworski L, Rupprecht R, Ross TL, Berding G, Weissenborn K. Reduced microglia activity in patients with long-term immunosuppressive therapy after liver transplantation. Eur J Nucl Med Mol Imaging 2021; 49:234-245. [PMID: 33978829 PMCID: PMC8712291 DOI: 10.1007/s00259-021-05398-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/02/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE Calcineurin inhibitors (CNI) can cause long-term impairment of brain function. Possible pathomechanisms include alterations of the cerebral immune system. This study used positron emission tomography (PET) imaging with the translocator protein (TSPO) ligand 18F-GE-180 to evaluate microglial activation in liver-transplanted patients under different regimens of immunosuppression. METHODS PET was performed in 22 liver-transplanted patients (3 CNI free, 9 with low-dose CNI, 10 with standard-dose CNI immunosuppression) and 9 healthy controls. The total distribution volume (VT) estimated in 12 volumes-of-interest was analyzed regarding TSPO genotype, CNI therapy, and cognitive performance. RESULTS In controls, VT was about 80% higher in high affinity binders (n = 5) compared to mixed affinity binders (n = 3). Mean VT corrected for TSPO genotype was significantly lower in patients compared to controls, especially in patients in whom CNI dose had been reduced because of nephrotoxic side effect. CONCLUSION Our results provide evidence of chronic suppression of microglial activity in liver-transplanted patients under CNI therapy especially in patients with high sensitivity to CNI toxicity.
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Affiliation(s)
- Meike Dirks
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany.
| | - Ralph Buchert
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ann-Katrin Wirries
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Henning Pflugrad
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
| | - Gerrit M Grosse
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Carlotta Petrusch
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Christian Schütze
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Florian Wilke
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Martin Mamach
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Linda Hamann
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Laura B N Langer
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Xiao-Qi Ding
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Hannelore Barg-Hock
- General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Jürgen Klempnauer
- General, Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Mario Lukacevic
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Eike Janssen
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Mariella Kessler
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Frank M Bengel
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Lilli Geworski
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Tobias L Ross
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Georg Berding
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Karin Weissenborn
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
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23
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Zhou R, Ji B, Kong Y, Qin L, Ren W, Guan Y, Ni R. PET Imaging of Neuroinflammation in Alzheimer's Disease. Front Immunol 2021; 12:739130. [PMID: 34603323 PMCID: PMC8481830 DOI: 10.3389/fimmu.2021.739130] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/27/2021] [Indexed: 12/15/2022] Open
Abstract
Neuroinflammation play an important role in Alzheimer's disease pathogenesis. Advances in molecular imaging using positron emission tomography have provided insights into the time course of neuroinflammation and its relation with Alzheimer's disease central pathologies in patients and in animal disease models. Recent single-cell sequencing and transcriptomics indicate dynamic disease-associated microglia and astrocyte profiles in Alzheimer's disease. Mitochondrial 18-kDa translocator protein is the most widely investigated target for neuroinflammation imaging. New generation of translocator protein tracers with improved performance have been developed and evaluated along with tau and amyloid imaging for assessing the disease progression in Alzheimer's disease continuum. Given that translocator protein is not exclusively expressed in glia, alternative targets are under rapid development, such as monoamine oxidase B, matrix metalloproteinases, colony-stimulating factor 1 receptor, imidazoline-2 binding sites, cyclooxygenase, cannabinoid-2 receptor, purinergic P2X7 receptor, P2Y12 receptor, the fractalkine receptor, triggering receptor expressed on myeloid cells 2, and receptor for advanced glycation end products. Promising targets should demonstrate a higher specificity for cellular locations with exclusive expression in microglia or astrocyte and activation status (pro- or anti-inflammatory) with highly specific ligand to enable in vivo brain imaging. In this review, we summarised recent advances in the development of neuroinflammation imaging tracers and provided an outlook for promising targets in the future.
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Affiliation(s)
- Rong Zhou
- Department of Nephrology, Yangpu Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Bin Ji
- Department of Radiopharmacy and Molecular Imaging, School of Pharmacy, Fudan University, Shanghai, China
| | - Yanyan Kong
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Limei Qin
- Inner Mongolia Baicaotang Qin Chinese Mongolia Hospital, Hohhot, China
| | - Wuwei Ren
- School of Information Science and Technology, Shanghaitech University, Shanghai, China
| | - Yihui Guan
- Positron Emission Tomography (PET) Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, University of Zurich & Eidgenössische Technische Hochschule Zürich (ETH Zurich), Zurich, Switzerland
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24
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Feasibility of TSPO-Specific Positron Emission Tomography Radiotracer for Evaluating Paracetamol-Induced Liver Injury. Diagnostics (Basel) 2021; 11:diagnostics11091661. [PMID: 34574002 PMCID: PMC8467059 DOI: 10.3390/diagnostics11091661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 01/16/2023] Open
Abstract
Macrophages are activated during the early phase of paracetamol-induced liver injury (PLI). [18F]GE180 is a radiolabeled ligand that recognizes the macrophage translocator protein (TSPO). In this study, we evaluated the feasibility of a TSPO-specific radiotracer in a rat model of PLI. A rat model of liver injury was induced by intraperitoneal administration of paracetamol. [18F]GE180 positron emission tomography (PET) images were obtained after 24 h. The maximal and mean standardized uptake values (SUVmax and SUVav) of the liver and serum biomarker levels were examined. The TSPO expression level was examined using real-time polymerase chain reaction and Western blot analysis. [18F]GE180 hepatic uptake in the PLI group was significantly higher than that in the control group (SUVmax p = 0.001; SUVav p = 0.005). Both mRNA and protein TSPO expression levels were higher in the PLI group. The mRNA expression level of TSPO was significantly correlated with [18F]GE180 hepatic uptake in both groups (SUVmax p = 0.019; SUVav p = 0.007). [18F]GE180 hepatic uptake in the PLI group showed a significant positive correlation with ALT24 and ALT48 (ALT24 p = 0.016; ALT48p = 0.002). [18F]GE180 enabled visualization of PLI through TSPO overexpression. Our results support the potential utility of hepatic uptake by TSPO-PET as a non-invasive imaging biomarker for the early phase of PLI.
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25
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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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26
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Vettermann FJ, Harris S, Schmitt J, Unterrainer M, Lindner S, Rauchmann BS, Palleis C, Weidinger E, Beyer L, Eckenweber F, Schuster S, Biechele G, Ferschmann C, Milenkovic VM, Wetzel CH, Rupprecht R, Janowitz D, Buerger K, Perneczky R, Höglinger GU, Levin J, Haass C, Tonn JC, Niyazi M, Bartenstein P, Albert NL, Brendel M. Impact of TSPO Receptor Polymorphism on [ 18F]GE-180 Binding in Healthy Brain and Pseudo-Reference Regions of Neurooncological and Neurodegenerative Disorders. Life (Basel) 2021; 11:484. [PMID: 34073557 PMCID: PMC8229996 DOI: 10.3390/life11060484] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/20/2022] Open
Abstract
TSPO-PET tracers are sensitive to a single-nucleotide polymorphism (rs6971-SNP), resulting in low-, medium- and high-affinity binders (LABs, MABs and HABS), but the clinical relevance of [18F]GE-180 is still unclear. We evaluated the impact of rs6971-SNP on in vivo [18F]GE-180 binding in a healthy brain and in pseudo-reference tissue in neuro-oncological and neurodegenerative diseases. Standardized uptake values (SUVs) of [18F]GE-180-PET were assessed using a manually drawn region of interest in the frontoparietal and cerebellar hemispheres. The SUVs were compared between the LABs, MABs and HABs in control, glioma, four-repeat tauopathy (4RT) and Alzheimer's disease (AD) subjects. Second, the SUVs were compared between the patients and controls within their rs6971-subgroups. After excluding patients with prior therapy, 24 LABs (7 control, 5 glioma, 6 4RT and 6 AD) were analyzed. Age- and sex-matched MABs (n = 38) and HABs (n = 50) were selected. The LABs had lower frontoparietal and cerebellar SUVs when compared with the MABs and HABs, but no significant difference was observed between the MABs and HABs. Within each rs6971 group, no SUV difference between the patients and controls was detected in the pseudo-reference tissues. The rs6971-SNP affects [18F]GE-180 quantification, revealing lower binding in the LABs when compared to the MABs and HABs. The frontoparietal and cerebellar ROIs were successfully validated as pseudo-reference regions.
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Affiliation(s)
- Franziska J Vettermann
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Stefanie Harris
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Julia Schmitt
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Marcus Unterrainer
- Department of Radiology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Boris-Stephan Rauchmann
- Department of Radiology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- Department of Psychiatry and Psychotherapy, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Carla Palleis
- Department of Neurology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Endy Weidinger
- Department of Neurology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Florian Eckenweber
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Sebastian Schuster
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Gloria Biechele
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Christian Ferschmann
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Vladimir M Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Daniel Janowitz
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Katharina Buerger
- Institute for Stroke and Dementia Research, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
| | - Robert Perneczky
- Department of Psychiatry and Psychotherapy, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Ageing Epidemiology (AGE) Research Unit, School of Public Health, Imperial College, London SW7 2AZ, UK
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Günter U Höglinger
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | - Johannes Levin
- Department of Neurology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, LMU Munich, 82152 Planegg, Germany
| | - Joerg C Tonn
- Department of Neurosurgery, University Hospital of Munich, 81377 Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, 81377 Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, 81377 Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, 81377 Munich, Germany
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27
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Nikam RM, Yue X, Kandula VV, Paudyal B, Langhans SA, Averill LW, Choudhary AK. Unravelling neuroinflammation in abusive head trauma with radiotracer imaging. Pediatr Radiol 2021; 51:966-970. [PMID: 33999238 DOI: 10.1007/s00247-021-04995-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/07/2020] [Accepted: 01/27/2021] [Indexed: 01/07/2023]
Abstract
Abusive head trauma (AHT) is a leading cause of mortality and morbidity in child abuse, with a mortality rate of approximately 25%. In survivors, the prognosis remains dismal, with high prevalence of cerebral palsy, epilepsy and neuropsychiatric disorders. Early and accurate diagnosis of AHT is challenging, both clinically and radiologically, with up to one-third of cases missed on initial examination. Moreover, most of the management in AHT is supportive, reflective of the lack of clear understanding of specific pathogenic mechanisms underlying secondary insult, with approaches targeted toward decreasing intracranial hypertension and reducing cerebral metabolism, cell death and excitotoxicity. Multiple studies have elucidated the role of pro- and anti-inflammatory cytokines and chemokines with upregulation/recruitment of microglia/macrophages, oligodendrocytes and astrocytes in severe traumatic brain injury (TBI). In addition, recent studies in animal models of AHT have demonstrated significant upregulation of microglia, with a potential role of inflammatory cascade contributing to secondary insult. Despite the histological and biochemical evidence, there is a significant dearth of specific imaging approaches to identify this neuroinflammation in AHT. The primary motivation for development of such imaging approaches stems from the need to therapeutically target neuroinflammation and establish its utility in monitoring and prognostication. In the present paper, we discuss the available data suggesting the potential role of neuroinflammation in AHT and role of radiotracer imaging in aiding diagnosis and patient management.
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Affiliation(s)
- Rahul M Nikam
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA. .,Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
| | - Xuyi Yue
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Vinay V Kandula
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA
| | - Bishnuhari Paudyal
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Sigrid A Langhans
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Lauren W Averill
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA
| | - Arabinda K Choudhary
- Department of Radiology, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
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28
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Ni R, Röjdner J, Voytenko L, Dyrks T, Thiele A, Marutle A, Nordberg A. In vitro Characterization of the Regional Binding Distribution of Amyloid PET Tracer Florbetaben and the Glia Tracers Deprenyl and PK11195 in Autopsy Alzheimer's Brain Tissue. J Alzheimers Dis 2021; 80:1723-1737. [PMID: 33749648 PMCID: PMC8150513 DOI: 10.3233/jad-201344] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Emerging evidence indicates a central role of gliosis in Alzheimer's disease (AD) pathophysiology. However, the regional distribution and interaction of astrogliosis and microgliosis in association with amyloid-β (Aβ) still remain uncertain. OBJECTIVE Here we studied the pathological profiles in autopsy AD brain by using specific imaging tracers. METHODS Autopsy brain tissues of AD (n = 15, age 70.4±8.5 years) and control cases (n = 12, age 76.6±10.9) were examined with homogenate binding assays, autoradiography for Aβ plaques (3H-florbetaben/3H-PIB), astrogliosis (3H-L-deprenyl), and microgliosis (3H-PK11195/3H-FEMPA), as well as immunoassays. RESULTS In vitro saturation analysis revealed high-affinity binding sites of 3H-florbetaben, 3H-L-deprenyl, and 3H-PK11195/3H-FEMPA in the frontal cortex of AD cases. In vitro3H-florbetaben binding increased across cortical and subcortical regions of AD compared to control with the highest binding in the frontal and parietal cortices. The in vitro3H-L-deprenyl binding showed highest binding in the hippocampus (dentate gyrus) followed by cortical and subcortical regions of AD while the GFAP expression was upregulated only in the hippocampus compared to control. The in vitro3H-PK11195 binding was solely increased in the parietal cortex and the hippocampus of AD compared to control. The 3H-florbetaben binding positively correlated with the 3H-L-deprenyl binding in the hippocampus and parietal cortex of AD and controls. Similarly, a positive correlation was observed between 3H-florbetaben binding and GFAP expression in hippocampus of AD and control. CONCLUSION The use of multi-imaging tracers revealed different regional pattern of changes in autopsy AD brain with respect to amyloid plaque pathology versus astrogliosis and microgliosis.
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Affiliation(s)
- Ruiqing Ni
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Jennie Röjdner
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Larysa Voytenko
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Amelia Marutle
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,Theme Aging, The Aging Brain Unit, Karolinska University Hospital, Stockholm, Sweden
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29
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MacAskill MG, Stadulyte A, Williams L, Morgan TEF, Sloan NL, Alcaide-Corral CJ, Walton T, Wimberley C, McKenzie CA, Spath N, Mungall W, BouHaidar R, Dweck MR, Gray GA, Newby DE, Lucatelli C, Sutherland A, Pimlott SL, Tavares AAS. Quantification of Macrophage-Driven Inflammation During Myocardial Infarction with 18F-LW223, a Novel TSPO Radiotracer with Binding Independent of the rs6971 Human Polymorphism. J Nucl Med 2021; 62:536-544. [PMID: 32859708 PMCID: PMC8049364 DOI: 10.2967/jnumed.120.243600] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/28/2020] [Indexed: 01/09/2023] Open
Abstract
Myocardial infarction (MI) is one of the leading causes of death worldwide, and inflammation is central to tissue response and patient outcomes. The 18-kDa translocator protein (TSPO) has been used in PET as an inflammatory biomarker. The aims of this study were to screen novel, fluorinated, TSPO radiotracers for susceptibility to the rs6971 genetic polymorphism using in vitro competition binding assays in human brain and heart; assess whether the in vivo characteristics of our lead radiotracer, 18F-LW223, are suitable for clinical translation; and validate whether 18F-LW223 can detect macrophage-driven inflammation in a rat MI model. Methods: Fifty-one human brain and 29 human heart tissue samples were screened for the rs6971 polymorphism. Competition binding assays were conducted with 3H-PK11195 and the following ligands: PK11195, PBR28, and our novel compounds (AB5186 and LW223). Naïve rats and mice were used for in vivo PET kinetic studies, radiometabolite studies, and dosimetry experiments. Rats underwent permanent coronary artery ligation and were scanned using PET/CT with an invasive input function at 7 d after MI. For quantification of PET signal in the hypoperfused myocardium, K1 (rate constant for transfer from arterial plasma to tissues) was used as a surrogate marker of perfusion to correct the binding potential for impaired radiotracer transfer from plasma to tissue (BPTC). Results: LW223 binding to TSPO was not susceptible to the rs6971 genetic polymorphism in human brain and heart samples. In rodents, 18F-LW223 displayed a specific uptake consistent with TSPO expression, a slow metabolism in blood (69% of parent at 120 min), a high plasma free fraction of 38.5%, and a suitable dosimetry profile (effective dose of 20.5-24.5 μSv/MBq). 18F-LW223 BPTC was significantly higher in the MI cohort within the infarct territory of the anterior wall relative to the anterior wall of naïve animals (32.7 ± 5.0 vs. 10.0 ± 2.4 cm3/mL/min, P ≤ 0.001). Ex vivo immunofluorescent staining for TSPO and CD68 (macrophage marker) resulted in the same pattern seen with in vivo BPTC analysis. Conclusion:18F-LW223 is not susceptible to the rs6971 genetic polymorphism in in vitro assays, has favorable in vivo characteristics, and is able to accurately map macrophage-driven inflammation after MI.
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Affiliation(s)
- Mark G MacAskill
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Agne Stadulyte
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Lewis Williams
- School of Chemistry, WestCHEM, University of Glasgow, Glasgow, United Kingdom
| | - Timaeus E F Morgan
- School of Chemistry, WestCHEM, University of Glasgow, Glasgow, United Kingdom
| | - Nikki L Sloan
- School of Chemistry, WestCHEM, University of Glasgow, Glasgow, United Kingdom
| | - Carlos J Alcaide-Corral
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Tashfeen Walton
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Catriona Wimberley
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Chris-Anne McKenzie
- MRC Edinburgh Brain Tissue Bank, University of Edinburgh, Edinburgh, United Kingdom
| | - Nick Spath
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - William Mungall
- Bioresearch and Veterinary Services, University of Edinburgh, Edinburgh, United Kingdom
| | - Ralph BouHaidar
- Forensic Pathology, University of Edinburgh, Edinburgh, United Kingdom
| | - Marc R Dweck
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Gillian A Gray
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - David E Newby
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Andrew Sutherland
- School of Chemistry, WestCHEM, University of Glasgow, Glasgow, United Kingdom
| | - Sally L Pimlott
- School of Medicine, University of Glasgow, Glasgow, United Kingdom; and
- NHS Greater Glasgow and Clyde, Glasgow, United Kingdom
| | - Adriana A S Tavares
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
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30
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Mahler C, Schumacher AM, Unterrainer M, Kaiser L, Höllbacher T, Lindner S, Havla J, Ertl-Wagner B, Patzig M, Seelos K, Neitzel J, Mäurer M, Krumbholz M, Metz I, Brück W, Stadelmann C, Merkler D, Gass A, Milenkovic V, Bartenstein P, Albert NL, Kümpfel T, Kerschensteiner M. TSPO PET imaging of natalizumab-associated progressive multifocal leukoencephalopathy. Brain 2021; 144:2683-2695. [PMID: 33757118 DOI: 10.1093/brain/awab127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 02/10/2021] [Accepted: 03/01/2021] [Indexed: 01/31/2023] Open
Abstract
Progressive multifocal leukoencephalopathy (PML) is a severe infection of the central nervous system caused by the polyomavirus JC (JCV) that can occur in multiple sclerosis (MS) patients treated with natalizumab. Clinical management of patients with natalizumab-associated PML is challenging not the least because current imaging tools for the early detection, longitudinal monitoring and differential diagnosis of PML lesions are limited. Here we evaluate whether TSPO positron emission tomography (PET) imaging can be applied to monitor the inflammatory activity of PML lesions over time and differentiate them from MS lesions. For this monocenter pilot study we followed 8 patients with natalizumab-associated PML with PET imaging using the TSPO radioligand [18F]GE-180 combined with frequent 3 T MRI imaging. In addition we compared TSPO PET signals in PML lesions with the signal pattern of MS lesions from 17 independent MS patients. We evaluated the standardized uptake value ratio (SUVR) as well as the morphometry of the TSPO uptake for putative PML and MS lesions areas compared to a radiologically unaffected pseudo-reference region in the cerebrum. Furthermore TSPO expression in situ was immunohistochemically verified by determining the density and cellular identity of TSPO-expressing cells in brain sections from four patients with early natalizumab-associated PML as well as five patients with other forms of PML and six patients with inflammatory demyelinating CNS lesions (clinically isolated syndrome/MS). Histological analysis revealed a reticular accumulation of TSPO expressing phagocytes in PML lesions, while such phagocytes showed a more homogenous distribution in putative MS lesions. TSPO PET imaging showed an enhanced tracer uptake in natalizumab-associated PML lesions that was present from the early to the chronic stages (up to 52 months after PML diagnosis). While gadolinium enhancement on MRI rapidly declined to baseline levels, TSPO tracer uptake followed a slow one phase decay curve. A TSPO-based 3-dimensional diagnostic matrix taking into account the uptake levels as well as the shape and texture of the TSPO signal differentiated more than 96% of PML and MS lesions. Indeed, treatment with rituximab after natalizumab-associated PML in three patients did not affect tracer uptake in the assigned PML lesions but reverted tracer uptake to baseline in the assigned active MS lesions. Taken together our study suggests that TSPO PET imaging can reveal CNS inflammation in natalizumab-associated PML. TSPO PET may facilitate longitudinal monitoring of disease activity and help to distinguish recurrent MS activity from PML progression.
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Affiliation(s)
- Christoph Mahler
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Biomedical Center (BMC), Medical Faculty, Ludwig-Maximilians-Universität Munich, Martinsried, Germany
| | - Adrian-Minh Schumacher
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Biomedical Center (BMC), Medical Faculty, Ludwig-Maximilians-Universität Munich, Martinsried, Germany
| | - Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Thomas Höllbacher
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Joachim Havla
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Biomedical Center (BMC), Medical Faculty, Ludwig-Maximilians-Universität Munich, Martinsried, Germany
| | - Birgit Ertl-Wagner
- Institute of Clinical Radiology, University Hospital Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Maximilian Patzig
- Institute of Neuroradiology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Klaus Seelos
- Institute of Neuroradiology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Julia Neitzel
- Institute for Stroke and Dementia Research, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | | | - Markus Krumbholz
- Department of Neurology & Stroke and Hertie-Institute for Clinical Brain Research, Eberhard Karl University of Tübingen, Tübingen, Germany
| | - Imke Metz
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Wolfgang Brück
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Doron Merkler
- Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland.,Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Achim Gass
- Department of Neurology, University Hospital Mannheim, Mannheim, Germany
| | - Vladimir Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Tania Kümpfel
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Biomedical Center (BMC), Medical Faculty, Ludwig-Maximilians-Universität Munich, Martinsried, Germany
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany.,Biomedical Center (BMC), Medical Faculty, Ludwig-Maximilians-Universität Munich, Martinsried, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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31
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Rivière G, Jaipuria G, Andreas LB, Leonov A, Giller K, Becker S, Zweckstetter M. Membrane-embedded TSPO: an NMR view. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:173-180. [PMID: 33354729 PMCID: PMC8071791 DOI: 10.1007/s00249-020-01487-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/19/2020] [Accepted: 11/26/2020] [Indexed: 12/21/2022]
Abstract
Translocator Protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein commonly used as a biomarker for neuroinflammation and is also a potential therapeutic target in neurodegenerative diseases. Despite intensive research efforts, the function of TSPO is still largely enigmatic. Deciphering TSPO structure in the native lipid environment is essential to gain insight into its cellular activities and to design improved diagnostic and therapeutic ligands. Here, we discuss the influence of lipid composition on the structure of mammalian TSPO embedded into lipid bilayers on the basis of solid-state NMR experiments. We further highlight that cholesterol can influence both the tertiary and quaternary TSPO structure and also influence TSPO localization in mitochondria-associated endoplasmic reticulum membranes.
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Affiliation(s)
- Gwladys Rivière
- Senior Research Group of Translational Structural Biology in Dementia, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany
| | - Garima Jaipuria
- Senior Research Group of Translational Structural Biology in Dementia, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany
| | - Loren B Andreas
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Andrei Leonov
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Karin Giller
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Stefan Becker
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Markus Zweckstetter
- Senior Research Group of Translational Structural Biology in Dementia, Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.
- Department of Neurology, University Medical Center Göttingen, University of Göttingen, Waldweg 33, 37073, Göttingen, Germany.
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.
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32
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Adhikari A, Singh P, Mahar KS, Adhikari M, Adhikari B, Zhang MR, Tiwari AK. Mapping of Translocator Protein (18 kDa) in Peripheral Sterile Inflammatory Disease and Cancer through PET Imaging. Mol Pharm 2021; 18:1507-1529. [PMID: 33645995 DOI: 10.1021/acs.molpharmaceut.1c00002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Positron emission tomography (PET) imaging of the translocator 18 kDa protein (TSPO) with radioligands has become an effective means of research in peripheral inflammatory conditions that occur in many diseases and cancers. The peripheral sterile inflammatory diseases (PSIDs) are associated with a diverse group of disorders that comprises numerous enduring insults including the cardiovascular, respiratory, gastrointestinal, or musculoskeletal system. TSPO has recently been introduced as a potential biomarker for peripheral sterile inflammatory diseases (PSIDs). The major critical issue related to PSIDs is its timely characterization and localization of inflammatory foci for proper therapy of patients. As an alternative to metabolic imaging, protein imaging expressed on immune cells after activation is of great importance. The five transmembrane domain translocator protein-18 kDa (TSPO) is upregulated on the mitochondrial cell surface of macrophages during inflammation, serving as a potential ligand for PET tracers. Additionally, the overexpressed TSPO protein has been positively correlated with various tumor malignancies. In view of the association of escalated TSPO expression in both disease conditions, it is an immensely important biomarker for PET imaging in oncology and PSIDs. In this review, we summarize the most outstanding advances on TSPO-targeted PSIDs and cancer in the development of TSPO ligands as a potential diagnostic tool, specifically discussing the last five years.
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Affiliation(s)
- Anupriya Adhikari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, (A Central University), Lucknow, Uttar Pradesh 226025, India
| | - Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, A Central University, Lucknow, Uttar Pradesh 226025, India
| | - Kamalesh S Mahar
- Birbal Sahni Institute of Palaeosciences, Lucknow, Uttar Pradesh 226007, India
| | - Manish Adhikari
- The George Washington University, Washington, D.C. 20052, United States
| | - Bhawana Adhikari
- Plasma Bio-science Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Anjani Kumar Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, (A Central University), Lucknow, Uttar Pradesh 226025, India
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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: 78] [Impact Index Per Article: 26.0] [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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Abstract
This article presents an overview of imaging agents for PET that have been applied for research and diagnostic purposes in patients affected by dementia. Classified by the target which the agents visualize, seven groups of tracers can be distinguished, namely radiopharmaceuticals for: (1) Misfolded proteins (ß-amyloid, tau, α-synuclein), (2) Neuroinflammation (overexpression of translocator protein), (3) Elements of the cholinergic system, (4) Elements of monoamine neurotransmitter systems, (5) Synaptic density, (6) Cerebral energy metabolism (glucose transport/ hexokinase), and (7) Various other proteins. This last category contains proteins involved in mechanisms underlying neuroinflammation or cognitive impairment, which may also be potential therapeutic targets. Many receptors belong to this category: AMPA, cannabinoid, colony stimulating factor 1, metabotropic glutamate receptor 1 and 5 (mGluR1, mGluR5), opioid (kappa, mu), purinergic (P2X7, P2Y12), sigma-1, sigma-2, receptor for advanced glycation endproducts, and triggering receptor expressed on myeloid cells-1, besides several enzymes: cyclooxygenase-1 and 2 (COX-1, COX-2), phosphodiesterase-5 and 10 (PDE5, PDE10), and tropomyosin receptor kinase. Significant advances in neuroimaging have been made in the last 15 years. The use of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) for quantification of regional cerebral glucose metabolism is well-established. Three tracers for ß-amyloid plaques have been approved by the Food and Drug Administration and European Medicines Agency. Several tracers for tau neurofibrillary tangles are already applied in clinical research. Since many novel agents are in the preclinical or experimental stage of development, further advances in nuclear medicine imaging can be expected in the near future. PET studies with established tracers and tracers for novel targets may result in early diagnosis and better classification of neurodegenerative disorders and in accurate monitoring of therapy trials which involve these targets. PET data have prognostic value and may be used to assess the response of the human brain to interventions, or to select the appropriate treatment strategy for an individual patient.
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Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands.
| | - Sofia Marcolini
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands
| | - Peter Paul de Deyn
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands; University of Antwerp, Born-Bunge Institute, Neurochemistry and Behavior, Campus Drie Eiken, Wilrijk, Belgium
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands; Ghent University, Ghent, Belgium
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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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Dubash S, Inglese M, Mauri F, Kozlowski K, Trivedi P, Arshad M, Challapalli A, Barwick T, Al-Nahhas A, Stanbridge R, Lewanski C, Berry M, Bowen F, Aboagye EO. Spatial heterogeneity of radiolabeled choline positron emission tomography in tumors of patients with non-small cell lung cancer: first-in-patient evaluation of [ 18F]fluoromethyl-(1,2- 2H 4)-choline. Theranostics 2020; 10:8677-8690. [PMID: 32754271 PMCID: PMC7392021 DOI: 10.7150/thno.47298] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/19/2020] [Indexed: 12/26/2022] Open
Abstract
Purpose: The spatio-molecular distribution of choline and its metabolites in tumors is highly heterogeneous. Due to regulation of choline metabolism by hypoxic transcriptional signaling and other survival factors, we envisage that detection of such heterogeneity in patient tumors could provide the basis for advanced localized therapy. However, non-invasive methods to assess this phenomenon in patients are limited. We investigated such heterogeneity in Non-Small Cell Lung Cancer (NSCLC) with [18F]fluoromethyl-(1,2-2H4) choline ([18F]D4-FCH) and positron emission tomography/computed tomography (PET/CT). Experimental design: [18F]D4-FCH (300.5±72.9MBq [147.60-363.6MBq]) was administered intravenously to 17 newly diagnosed NSCLC patients. PET/CT scans were acquired concurrently with radioactive blood sampling to permit mathematical modelling of blood-tissue transcellular rate constants. Comparisons were made with biopsy-derived choline kinase-α (CHKα) expression and diagnostic [18F]fluorodeoxyglucose ([18F]FDG) scans. Results: Oxidation of [18F]D4-FCH to [18F]D4-fluorobetaine was suppressed (48.58±0.31% parent at 60 min) likely due to the deuterium isotope effect embodied within the design of the radiotracer. Early (5 min) and late (60 min) images showed specific uptake of tracer in all 51 lesions (tumors, lymph nodes and metastases) from 17 patients analyzed. [18F]D4-FCH-derived uptake (SUV60max) in index primary lesions (n=17) ranged between 2.87-10.13; lower than that of [18F]FDG PET [6.89-22.64]. Mathematical modelling demonstrated net irreversible uptake of [18F]D4-FCH at steady-state, and parametric mapping of the entire tumor showed large intratumorally heterogeneity in radiotracer retention, which is likely to have influenced correlations with biopsy-derived CHKα expression. Conclusions: [18F]D4-FCH is detectable in NSCLC with large intratumorally heterogeneity, which could be exploited in the future for targeting localized therapy.
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Affiliation(s)
- Suraiya Dubash
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Marianna Inglese
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Francesco Mauri
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Kasia Kozlowski
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Pritesh Trivedi
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Mubarik Arshad
- Department of Surgery and Cancer, Imperial College London, United Kingdom
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | | | - Tara Barwick
- Department of Surgery and Cancer, Imperial College London, United Kingdom
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Adil Al-Nahhas
- Department of Radiology/Nuclear Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Rex Stanbridge
- Department of Surgery and Cancer, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Conrad Lewanski
- Department of Surgery and Cancer, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Matthew Berry
- Department of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Frances Bowen
- Department of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Eric O. Aboagye
- Department of Surgery and Cancer, Imperial College London, United Kingdom
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In response to: Anatomy of 18F-GE180, a failed radioligand for the TSPO protein. Eur J Nucl Med Mol Imaging 2020; 47:2237-2241. [PMID: 32524162 PMCID: PMC7396400 DOI: 10.1007/s00259-020-04885-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 01/11/2023]
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Sridharan S, Raffel J, Nandoskar A, Record C, Brooks DJ, Owen D, Sharp D, Muraro PA, Gunn R, Nicholas R. Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 21:935-944. [PMID: 30796709 DOI: 10.1007/s11307-019-01323-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurements of non-displaceable binding (VND) of positron emission tomography (PET) ligands are not often made in vivo in humans because they require ligands to displace binding to target receptors and there are few readily available, safe ones to use. A technique to measure VND for ligands for the 18-kDa translocator protein (TSPO) has recently been developed which compares the total volume of distribution (VT) before and after administration of the TSPO ligand XBD173. Here, we used XBD173 with an occupancy plot to quantify VND for two TSPO radiotracers, [18F]GE-180 and [11C]PBR28, in cohorts of people with multiple sclerosis (MS). Additionally, we compared plots of subjects carrying high (HAB) or mixed binding (MAB) affinity polymorphisms of TSPO to estimate VND without receptor blockade. PROCEDURES Twelve people with MS underwent baseline MRI and 90-min dynamic [18F]GE-180 PET or [11C]PBR28 PET (n = 6; three HAB, three MAB each). Arterial blood sampling was used to generate plasma input functions for the two-tissue compartment model. VND was calculated using two independent methods: the occupancy plot (by modelling the differences in signal post XBD173) and the polymorphism plot (by modelling the differences in signal across presence and absence of rs6971 genotypes). RESULTS Whole brain VT (mean ± standard deviation) was 0.29 ± 0.17 ml/cm3 for [18F]GE-180 and 5.01 ± 1.88 ml/cm3 for [11C]PBR28. Using the occupancy and polymorphism plots respectively, VND for [18F]GE-180 was 0.11 ml/cm3 (95 % CI = 0.02, 0.16) and 0.20 ml/cm3 (0.16, 0.34), accounting for, on average, 55 % of VT in the whole brain. For [11C]PBR28, these values were 3.81 ml/cm3 (3.02, 4.21) and 3.49 ml/cm3 (1.38, 4.27), accounting for 67 % of average whole brain VT. CONCLUSIONS Although VT for [18F]GE-180 is low, indicating low brain penetration, half the signal shown by MS subjects reflected specific TSPO binding. VT for [11C]PBR28 was higher and two thirds of the binding was non-specific. No brain ROIs were devoid of specific signal, further confirming that true reference tissue approaches are potentially problematic for estimating TSPO levels.
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Affiliation(s)
- Sujata Sridharan
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Joel Raffel
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Ashwini Nandoskar
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Chris Record
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David J Brooks
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle upon Tyne University, Newcastle upon Tyne, UK
| | - David Owen
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David Sharp
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Paolo A Muraro
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | | | - Richard Nicholas
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
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Tong J, Williams B, Rusjan PM, Mizrahi R, Lacapère JJ, McCluskey T, Furukawa Y, Guttman M, Ang LC, Boileau I, Meyer JH, Kish SJ. Concentration, distribution, and influence of aging on the 18 kDa translocator protein in human brain: Implications for brain imaging studies. J Cereb Blood Flow Metab 2020; 40:1061-1076. [PMID: 31220997 PMCID: PMC7181090 DOI: 10.1177/0271678x19858003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Positron emission tomography (PET) imaging of the translocator protein (TSPO) is widely used as a biomarker of microglial activation. However, TSPO protein concentration in human brain has not been optimally quantified nor has its regional distribution been compared to TSPO binding. We determined TSPO protein concentration, change with age, and regional distribution by quantitative immunoblotting in autopsied human brain. Brain TSPO protein concentration (>0.1 ng/µg protein) was higher than those reported by in vitro binding assays by at least 2 to 70 fold. TSPO protein distributed widely in both gray and white matter regions, with distribution in major gray matter areas ranked generally similar to that of PET binding in second-generation radiotracer studies. TSPO protein concentration in frontal cortex was high at birth, declined precipitously during the first three months, and increased modestly during adulthood/senescence (10%/decade; vs. 30% for comparison astrocytic marker GFAP). As expected, TSPO protein levels were significantly increased (+114%) in degenerating putamen in multiple system atrophy, providing further circumstantial support for TSPO as a gliosis marker. Overall, findings show some similarities between TSPO protein and PET binding characteristics in the human brain but also suggest that part of the TSPO protein pool might be less available for radioligand binding.
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Affiliation(s)
- Junchao Tong
- Preclinical Imaging, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Junchao Tong, Preclinical Imaging, Centre
for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8,
Canada.
| | - Belinda Williams
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Pablo M. Rusjan
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Romina Mizrahi
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités-UPMC University of
Paris 06, Département de Chimie, École Normale Supérieure-PSL Research University,
Paris, France
| | - Tina McCluskey
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Yoshiaki Furukawa
- Department of Neurology, Juntendo Tokyo
Koto Geriatric Medical Center, and Faculty of Medicine, University & Post
Graduate University of Juntendo, Tokyo, Japan
| | - Mark Guttman
- Centre for Movement Disorders, Toronto,
Ontario, Canada
| | - Lee-Cyn Ang
- Division of Neuropathology, London
Health Science Centre, University of Western Ontario, London, Ontario, Canada
| | - Isabelle Boileau
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Jeffrey H Meyer
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Stephen J Kish
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
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Reliable quantification of 18F-GE-180 PET neuroinflammation studies using an individually scaled population-based input function or late tissue-to-blood ratio. Eur J Nucl Med Mol Imaging 2020; 47:2887-2900. [PMID: 32322915 PMCID: PMC7651670 DOI: 10.1007/s00259-020-04810-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/02/2020] [Indexed: 01/23/2023]
Abstract
Purpose Tracer kinetic modeling of tissue time activity curves and the individual input function based on arterial blood sampling and metabolite correction is the gold standard for quantitative characterization of microglia activation by PET with the translocator protein (TSPO) ligand 18F-GE-180. This study tested simplified methods for quantification of 18F-GE-180 PET. Methods Dynamic 18F-GE-180 PET with arterial blood sampling and metabolite correction was performed in five healthy volunteers and 20 liver-transplanted patients. Population-based input function templates were generated by averaging individual input functions normalized to the total area under the input function using a leave-one-out approach. Individual population-based input functions were obtained by scaling the input function template with the individual parent activity concentration of 18F-GE-180 in arterial plasma in a blood sample drawn at 27.5 min or by the individual administered tracer activity, respectively. The total 18F-GE-180 distribution volume (VT) was estimated in 12 regions-of-interest (ROIs) by the invasive Logan plot using the measured or the population-based input functions. Late ROI-to-whole-blood and ROI-to-cerebellum ratio were also computed. Results Correlation with the reference VT (with individually measured input function) was very high for VT with the population-based input function scaled with the blood sample and for the ROI-to-whole-blood ratio (Pearson correlation coefficient = 0.989 ± 0.006 and 0.970 ± 0.005). The correlation was only moderate for VT with the population-based input function scaled with tracer activity dose and for the ROI-to-cerebellum ratio (0.653 ± 0.074 and 0.384 ± 0.177). Reference VT, population-based VT with scaling by the blood sample, and ROI-to-whole-blood ratio were sensitive to the TSPO gene polymorphism. Population-based VT with scaling to the administered tracer activity and the ROI-to-cerebellum ratio failed to detect a polymorphism effect. Conclusion These results support the use of a population-based input function scaled with a single blood sample or the ROI-to-whole-blood ratio at a late time point for simplified quantitative analysis of 18F-GE-180 PET. Electronic supplementary material The online version of this article (10.1007/s00259-020-04810-1) contains supplementary material, which is available to authorized users.
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Zanotti-Fregonara P, Pascual B, Rostomily RC, Rizzo G, Veronese M, Masdeu JC, Turkheimer F. Anatomy of 18F-GE180, a failed radioligand for the TSPO protein. Eur J Nucl Med Mol Imaging 2020; 47:2233-2236. [DOI: 10.1007/s00259-020-04732-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 02/17/2020] [Indexed: 12/21/2022]
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Ermert J, Benešová M, Hugenberg V, Gupta V, Spahn I, Pietzsch HJ, Liolios C, Kopka K. Radiopharmaceutical Sciences. Clin Nucl Med 2020. [DOI: 10.1007/978-3-030-39457-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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de Groot M, Patel N, Manavaki R, Janiczek RL, Bergstrom M, Östör A, Gerlag D, Roberts A, Graves MJ, Karkera Y, Fernando D, Mistry P, Walker A, Wisniacki N, Fryer TD, Jimenez-Royo P. Quantifying disease activity in rheumatoid arthritis with the TSPO PET ligand 18F-GE-180 and comparison with 18F-FDG and DCE-MRI. EJNMMI Res 2019; 9:113. [PMID: 31858293 PMCID: PMC6923307 DOI: 10.1186/s13550-019-0576-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/15/2019] [Indexed: 02/14/2023] Open
Abstract
Purpose While the aetiology of rheumatoid arthritis (RA) remains unclear, many of the inflammatory components are well characterised. For diagnosis and therapy evaluation, in vivo insight into these processes would be valuable. Various imaging probes have shown value including dynamic contrast-enhanced (DCE) MRI and PET/CT using 18F-fluorodeoxyglucose (18F-FDG) or tracers targeting the translocator protein (TSPO). To evaluate 18F-GE-180, a novel TSPO PET tracer, for detecting and quantifying disease activity in RA, we compared 18F-GE-180 uptake with that of 18F-FDG and DCE-MRI measures of inflammation. Methods Eight RA patients with moderate-to-high, stable disease activity and active disease in at least one wrist were included in this study (NCT02350426). Participants underwent PET/CT examinations with 18F-GE-180 and 18F-FDG on separate visits, covering the shoulders and from the pelvis to the feet, including hands and wrists. DCE-MRI was performed on one affected hand. Uptake was compared visually between tracers as judged by an experienced radiologist and quantitatively using the maximum standardised uptake value (SUVmax). Uptake for both tracers was correlated with DCE-MRI parameters of inflammation, including the volume transfer coefficient Ktrans using Pearson correlation (r). Results PET/CT imaging with 18F-GE-180 in RA patients showed marked extra-synovial uptake around the affected joints. Overall sensitivity for detecting clinically affected joints was low (14%). 18F-GE-180 uptake did not or only weakly correlate with DCE-MRI parameters in the wrist (r = 0.09–0.31). 18F-FDG showed higher sensitivity for detecting symptomatic joints (34%), as well as strong positive correlation with DCE-MRI parameters (SUVmax vs. Ktrans: r = 0.92 for wrist; r = 0.68 for metacarpophalangeal joints). Conclusions The correlations between DCE-MRI parameters and 18F-FDG uptake support use of this PET tracer for quantification of inflammatory burden in RA. The TSPO tracer 18F-GE-180, however, has shown limited use for the investigation of RA due to its poor sensitivity and ability to quantify disease activity in RA.
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Affiliation(s)
- Marius de Groot
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK.,Department of Radiology, University of Cambridge, Cambridge, UK
| | - Neel Patel
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK
| | - Roido Manavaki
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Robert L Janiczek
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK
| | - Mats Bergstrom
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK
| | - Andrew Östör
- Monash University, Cabrini Medical Centre, Melbourne, Australia
| | | | - Alexandra Roberts
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK
| | - Martin J Graves
- Department of Radiology, University of Cambridge, Cambridge, UK
| | | | - Disala Fernando
- Clinical Unit Cambridge (CUC), GlaxoSmithKline R&D, Addenbrooke's Hospital, Cambridge, UK
| | | | - Adam Walker
- Clinical Unit Cambridge (CUC), GlaxoSmithKline R&D, Addenbrooke's Hospital, Cambridge, UK
| | - Nicolas Wisniacki
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK
| | - Tim D Fryer
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Pilar Jimenez-Royo
- Clinical Pharmacology and Experimental Medicine, GlaxoSmithKline R&D, Gunnels Wood Road, Stevenage, UK.
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45
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Beaurain M, Salabert AS, Ribeiro MJ, Arlicot N, Damier P, Le Jeune F, Demonet JF, Payoux P. Innovative Molecular Imaging for Clinical Research, Therapeutic Stratification, and Nosography in Neuroscience. Front Med (Lausanne) 2019; 6:268. [PMID: 31828073 PMCID: PMC6890558 DOI: 10.3389/fmed.2019.00268] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 11/01/2019] [Indexed: 01/06/2023] Open
Abstract
Over the past few decades, several radiotracers have been developed for neuroimaging applications, especially in PET. Because of their low steric hindrance, PET radionuclides can be used to label molecules that are small enough to cross the blood brain barrier, without modifying their biological properties. As the use of 11C is limited by its short physical half-life (20 min), there has been an increasing focus on developing tracers labeled with 18F for clinical use. The first such tracers allowed cerebral blood flow and glucose metabolism to be measured, and the development of molecular imaging has since enabled to focus more closely on specific targets such as receptors, neurotransmitter transporters, and other proteins. Hence, PET and SPECT biomarkers have become indispensable for innovative clinical research. Currently, the treatment options for a number of pathologies, notably neurodegenerative diseases, remain only supportive and symptomatic. Treatments that slow down or reverse disease progression are therefore the subject of numerous studies, in which molecular imaging is proving to be a powerful tool. PET and SPECT biomarkers already make it possible to diagnose several neurological diseases in vivo and at preclinical stages, yielding topographic, and quantitative data about the target. As a result, they can be used for assessing patients' eligibility for new treatments, or for treatment follow-up. The aim of the present review was to map major innovative radiotracers used in neuroscience, and explain their contribution to clinical research. We categorized them according to their target: dopaminergic, cholinergic or serotoninergic systems, β-amyloid plaques, tau protein, neuroinflammation, glutamate or GABA receptors, or α-synuclein. Most neurological disorders, and indeed mental disorders, involve the dysfunction of one or more of these targets. Combinations of molecular imaging biomarkers can afford us a better understanding of the mechanisms underlying disease development over time, and contribute to early detection/screening, diagnosis, therapy delivery/monitoring, and treatment follow-up in both research and clinical settings.
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Affiliation(s)
- Marie Beaurain
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Anne-Sophie Salabert
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
| | - Maria Joao Ribeiro
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.,Inserm CIC 1415, University Hospital, Tours, France.,CHRU Tours, Tours, France
| | - Philippe Damier
- Inserm U913, Neurology Department, University Hospital, Nantes, France
| | | | - Jean-François Demonet
- Leenards Memory Centre, Department of Clinical Neuroscience, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Pierre Payoux
- CHU de Toulouse, Toulouse, France.,ToNIC, Toulouse NeuroImaging Center, Inserm U1214, Toulouse, France
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46
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Song YS. Perspectives in TSPO PET Imaging for Neurologic Diseases. Nucl Med Mol Imaging 2019; 53:382-385. [PMID: 31867073 DOI: 10.1007/s13139-019-00620-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 01/30/2023] Open
Abstract
The translocator protein (18 kDa) (TSPO) is a mitochondrial transmembrane protein, which has brought attention as a neuroinflammatory biomarker. Positron emission tomography (PET) imaging studies have been done for several decades, since neuroinflammation has been implicated as an important pathophysiology of several common neurologic disorders. However, despite numerous previous studies with positive findings, its clinical significance is not yet clear. Various attempts to overcome the limitations are ongoing, in order to bring acceptance for use in clinics.
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Affiliation(s)
- Yoo Sung Song
- Seoul National University Bundang Hospital, Seongnam, South Korea
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47
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Unterrainer M, Fleischmann DF, Vettermann F, Ruf V, Kaiser L, Nelwan D, Lindner S, Brendel M, Wenter V, Stöcklein S, Herms J, Milenkovic VM, Rupprecht R, Tonn JC, Belka C, Bartenstein P, Niyazi M, Albert NL. TSPO PET, tumour grading and molecular genetics in histologically verified glioma: a correlative 18F-GE-180 PET study. Eur J Nucl Med Mol Imaging 2019; 47:1368-1380. [PMID: 31486876 DOI: 10.1007/s00259-019-04491-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 08/19/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND The 18-kDa translocator protein (TSPO) is overexpressed in brain tumours and represents an interesting target for glioma imaging. 18F-GE-180, a novel TSPO ligand, has shown improved binding affinity and a high target-to-background contrast in patients with glioblastoma. However, the association of uptake characteristics on TSPO PET using 18F-GE-180 with the histological WHO grade and molecular genetic features so far remains unknown and was evaluated in the current study. METHODS Fifty-eight patients with histologically validated glioma at initial diagnosis or recurrence were included. All patients underwent 18F-GE-180 PET, and the maximal and mean tumour-to-background ratios (TBRmax, TBRmean) as well as the PET volume were assessed. On MRI, presence/absence of contrast enhancement was evaluated. Imaging characteristics were correlated with neuropathological parameters (i.e. WHO grade, isocitrate dehydrogenase (IDH) mutation, O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and telomerase reverse transcriptase (TERT) promoter mutation). RESULTS Six of 58 patients presented with WHO grade II, 16/58 grade III and 36/58 grade IV gliomas. An (IDH) mutation was found in 19/58 cases, and 39/58 were classified as IDH-wild type. High 18F-GE-180-uptake was observed in all but 4 cases (being WHO grade II glioma, IDH-mutant). A high association of 18F-GE-180-uptake and WHO grades was seen: WHO grade IV gliomas showed the highest uptake intensity compared with grades III and II gliomas (median TBRmax 5.15 (2.59-8.95) vs. 3.63 (1.85-7.64) vs. 1.63 (1.50-3.43), p < 0.001); this association with WHO grades persisted within the IDH-wild-type and IDH-mutant subgroup analyses (p < 0.05). Uptake intensity was also associated with the IDH mutational status with a trend towards higher 18F-GE-180-uptake in IDH-wild-type gliomas in the overall group (median TBRmax 4.67 (1.56-8.95) vs. 3.60 (1.50-7.64), p = 0.083); however, within each WHO grade, no differences were found (e.g. median TBRmax in WHO grade III glioma 4.05 (1.85-5.39) vs. 3.36 (2.32-7.64), p = 1.000). No association was found between uptake intensity and MGMT or TERT (p > 0.05 each). CONCLUSION Uptake characteristics on 18F-GE-180 PET are highly associated with the histological WHO grades, with the highest 18F-GE-180 uptake in WHO grade IV glioblastomas and a PET-positive rate of 100% among the investigated high-grade gliomas. Conversely, all TSPO-negative cases were WHO grade II gliomas. The observed association of 18F-GE-180 uptake and the IDH mutational status seems to be related to the high inter-correlation of the IDH mutational status and the WHO grades.
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Affiliation(s)
- M Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - D F Fleischmann
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - F Vettermann
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - V Ruf
- Department of Neuropathology, LMU Munich, Munich, Germany
| | - L Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - D Nelwan
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - S Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - M Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - V Wenter
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - S Stöcklein
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - J Herms
- Department of Neuropathology, LMU Munich, Munich, Germany
| | - V M Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - R Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - J C Tonn
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Neurosurgery, University Hospital, LMU Munich, Munich, Germany
| | - C Belka
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - P Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - M Niyazi
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - N L Albert
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.
- German Cancer Consortium (DKTK), Partner Site Munich, and German Cancer Research Center (DKFZ), Heidelberg, Germany.
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48
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Cheng HWA, Sokias R, Werry EL, Ittner LM, Reekie TA, Du J, Gao Q, Hibbs DE, Kassiou M. First Nondiscriminating Translocator Protein Ligands Produced from a Carbazole Scaffold. J Med Chem 2019; 62:8235-8248. [DOI: 10.1021/acs.jmedchem.9b00980] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
| | | | | | - Lars M. Ittner
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, 2 Technology Place, North Ryde, New South Wales 2109, Australia
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49
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Nag S, Krasikova R, Airaksinen AJ, Arakawa R, Petukhovd M, Gulyas B. Synthesis and biological evaluation of [ 18F]fluorovinpocetine, a potential PET radioligand for TSPO imaging. Bioorg Med Chem Lett 2019; 29:2270-2274. [PMID: 31257082 DOI: 10.1016/j.bmcl.2019.06.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 01/31/2023]
Abstract
Despite of various PET radioligands targeting the translocator protein TSPO 18-KDa are used for the investigations of neuroinflammatory conditions associated with neurological disorders, development of new TSPO radiotracers is still an active area of the researches with a major focus on the 18F-labelled radiotracers. Here, we report the radiochemical synthesis of [18F]vinpocetine, fluorinated analogue of previously reported TSPO radioligand, [11C]vinpocetine. Radiolabeling was achieved by [18F]fluoroethylation of apovincaminic acid with [18F]fluoroethyl bromide. [18F]vinpocetine was obtained in quantities >2.7 GBq in RCY of 13% (non-decay corrected), and molar activity >60 GBq/µmol within 95 min synthesis time. Preliminary PET studies in a cynomolgus monkey and metabolite studies by HPLC demonstrated similar results by [18F]vinpocetine as for [11C]vinpocetine, including high blood-brain barrier permeability, regional uptake pattern and fast washout from the NHP brain. These results demonstrate that [18F]fluorovinpocetine warrants further evaluation as an easier accessible alternative to [11C]vinpocetine.
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Affiliation(s)
- S Nag
- Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, Sweden.
| | - R Krasikova
- Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, Sweden; N.P. Bechtereva Institute of Human Brain Russian Academy of Sciences, St.-Petersburg, Russia
| | - A J Airaksinen
- Department of Chemistry - Radiochemistry, University of Helsinki, Finland
| | - R Arakawa
- Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, Sweden
| | - M Petukhovd
- Petersburg Nuclear Physics Institute named after B.P. Konstantinov, NRC "Kurchatov Institute", Gatchina, Russia; Peter the Great St.-Petersburg Polytechnic University, St.-Petersburg, Russia
| | - B Gulyas
- Karolinska Institutet, Department of Clinical Neuroscience, Stockholm, Sweden; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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50
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Dani M, Wood M, Mizoguchi R, Fan Z, Walker Z, Morgan R, Hinz R, Biju M, Kuruvilla T, Brooks DJ, Edison P. Microglial activation correlates in vivo with both tau and amyloid in Alzheimer's disease. Brain 2019; 141:2740-2754. [PMID: 30052812 DOI: 10.1093/brain/awy188] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 05/29/2018] [Indexed: 12/30/2022] Open
Abstract
Alzheimer's disease is characterized by the histopathological presence of amyloid-β plaques and tau-containing neurofibrillary tangles. Microglial activation is also a recognized pathological component. The relationship between microglial activation and protein aggregation is still debated. We investigated the relationship between amyloid plaques, tau tangles and activated microglia using PET imaging. Fifty-one subjects (19 healthy controls, 16 mild cognitive impairment and 16 Alzheimer's disease subjects) participated in the study. All subjects had neuropsychometric testing, MRI, amyloid (18F-flutemetamol), and microglial (11C-PBR28) PET. All subjects with mild cognitive impairment and Alzheimer's disease and eight of the controls had tau (18F-AV1451) PET. 11C-PBR28 PET was analysed using Logan graphical analysis with an arterial plasma input function, while 18F-flutemetamol and 18F-AV1451 PET were analysed as target:cerebellar ratios to create parametric standardized uptake value ratio maps. Biological parametric mapping in the Statistical Parametric Mapping platform was used to examine correlations between uptake of tracers at a voxel-level. There were significant widespread clusters of positive correlation between levels of microglial activation and tau aggregation in both the mild cognitive impairment (amyloid-positive and amyloid-negative) and Alzheimer's disease subjects. The correlations were stronger in Alzheimer's disease than in mild cognitive impairment, suggesting that these pathologies increase together as disease progresses. Levels of microglial activation and amyloid deposition were also correlated, although in a different spatial distribution; correlations were stronger in mild cognitive impairment than Alzheimer's subjects, in line with a plateauing of amyloid load with disease progression. Clusters of positive correlations between microglial activation and protein aggregation often targeted similar areas of association cortex, indicating that all three processes are present in specific vulnerable brain areas. For the first time using PET imaging, we show that microglial activation can correlate with both tau aggregation and amyloid deposition. This confirms the complex relationship between these processes. These results suggest that preventative treatment for Alzheimer's disease should target all three processes.
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Affiliation(s)
- Melanie Dani
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Melanie Wood
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Ruth Mizoguchi
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zhen Fan
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zuzana Walker
- Division of Psychiatry, University College London, UK.,Essex Partnership University NHS Foundation Trust, UK
| | | | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, UK
| | - Maya Biju
- Gether NHS Foundation Trust, Gloucester, UK
| | | | - David J Brooks
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK.,Department of Nuclear Medicine, Aarhus University, Denmark.,Institute of Neuroscience, University of Newcastle upon Tyne, UK
| | - Paul Edison
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
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