1
|
Chauveau F, Winkeler A, Chalon S, Boutin H, Becker G. PET imaging of neuroinflammation: any credible alternatives to TSPO yet? Mol Psychiatry 2024:10.1038/s41380-024-02656-9. [PMID: 38997465 DOI: 10.1038/s41380-024-02656-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 06/26/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024]
Abstract
Over the last decades, the role of neuroinflammation in neuropsychiatric conditions has attracted an exponentially growing interest. A key driver for this trend was the ability to image brain inflammation in vivo using PET radioligands targeting the Translocator Protein 18 kDa (TSPO), which is known to be expressed in activated microglia and astrocytes upon inflammatory events as well as constitutively in endothelial cells. TSPO is a mitochondrial protein that is expressed mostly by microglial cells upon activation but is also expressed by astrocytes in some conditions and constitutively by endothelial cells. Therefore, our current understanding of neuroinflammation dynamics is hampered by the lack of alternative targets available for PET imaging. We performed a systematic search and review on radiotracers developed for neuroinflammation PET imaging apart from TSPO. The following targets of interest were identified through literature screening (including previous narrative reviews): P2Y12R, P2X7R, CSF1R, COX (microglial targets), MAO-B, I2BS (astrocytic targets), CB2R & S1PRs (not specific of a single cell type). We determined the level of development and provided a scoping review for each target. Strikingly, astrocytic biomarker MAO-B has progressed in clinical investigations the furthest, while few radiotracers (notably targeting S1P1Rs, CSF1R) are being implemented in clinical investigations. Other targets such as CB2R and P2X7R have proven disappointing in clinical studies (e.g. poor signal, lack of changes in disease conditions, etc.). While astrocytic targets are promising, development of new biomarkers and tracers specific for microglial activation has proven challenging.
Collapse
Affiliation(s)
- Fabien Chauveau
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, Inserm U1028, CNRS UMR5292, BIORAN, Groupement Hospitalier Est - CERMEP, 59 boulevard Pinel, 69677, Bron, Cedex, France
| | - Alexandra Winkeler
- Université Paris-Saclay, Inserm, CNRS, CEA, BioMaps, Service Hospitalier Frédéric Joliot, 4 place du général Leclerc, 91401, Orsay, France
| | - Sylvie Chalon
- UMR 1253 iBrain, Université de Tours - INSERM, Bâtiment Planiol, UFR de Médecine, 10 Boulevard Tonnellé, 37032, Tours, Cedex 01, France
| | - Hervé Boutin
- UMR 1253 iBrain, Université de Tours - INSERM, Bâtiment Planiol, UFR de Médecine, 10 Boulevard Tonnellé, 37032, Tours, Cedex 01, France.
| | - Guillaume Becker
- Université Claude Bernard Lyon 1, Centre de Recherche en Neurosciences de Lyon, Inserm U1028, CNRS UMR5292, BIORAN, Groupement Hospitalier Est - CERMEP, 59 boulevard Pinel, 69677, Bron, Cedex, France
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, 14 rue Pierre et Marie Curie, 94701, Maisons-Alfort, Cedex, France
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Neumann KD, Broshek DK, Newman BT, Druzgal TJ, Kundu BK, Resch JE. Concussion: Beyond the Cascade. Cells 2023; 12:2128. [PMID: 37681861 PMCID: PMC10487087 DOI: 10.3390/cells12172128] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Sport concussion affects millions of athletes each year at all levels of sport. Increasing evidence demonstrates clinical and physiological recovery are becoming more divergent definitions, as evidenced by several studies examining blood-based biomarkers of inflammation and imaging studies of the central nervous system (CNS). Recent studies have shown elevated microglial activation in the CNS in active and retired American football players, as well as in active collegiate athletes who were diagnosed with a concussion and returned to sport. These data are supportive of discordance in clinical symptomology and the inflammatory response in the CNS upon symptom resolution. In this review, we will summarize recent advances in the understanding of the inflammatory response associated with sport concussion and broader mild traumatic brain injury, as well as provide an outlook for important research questions to better align clinical and physiological recovery.
Collapse
Affiliation(s)
- Kiel D. Neumann
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Donna K. Broshek
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA 22903, USA;
| | - Benjamin T. Newman
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - T. Jason Druzgal
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Bijoy K. Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Jacob E. Resch
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA
| |
Collapse
|
5
|
Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [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: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
Collapse
Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| |
Collapse
|
6
|
Kim MJ, Anaya FJ, Manly LS, Lee JH, Hong J, Shrestha S, Telu S, Henry K, Santamaria JAM, Liow JS, Zanotti-Fregonara P, Shetty HU, Zoghbi SS, Pike VW, Innis RB. Whole-Body PET Imaging in Humans Shows That 11C-PS13 Is Selective for Cyclooxygenase-1 and Can Measure the In Vivo Potency of Nonsteroidal Antiinflammatory Drugs. J Nucl Med 2023; 64:159-164. [PMID: 35798558 PMCID: PMC9841251 DOI: 10.2967/jnumed.122.264061] [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: 02/23/2022] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 01/28/2023] Open
Abstract
Both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) convert arachidonic acid to prostaglandin H2, which has proinflammatory effects. The recently developed PET radioligand 11C-PS13 has excellent in vivo selectivity for COX-1 over COX-2 in nonhuman primates. This study sought to evaluate the selectivity of 11C-PS13 binding to COX-1 in humans and assess the utility of 11C-PS13 to measure the in vivo potency of nonsteroidal antiinflammatory drugs. Methods: Baseline 11C-PS13 whole-body PET scans were obtained for 26 healthy volunteers, followed by blocked scans with ketoprofen (n = 8), celecoxib (n = 8), or aspirin (n = 8). Ketoprofen is a highly potent and selective COX-1 inhibitor, celecoxib is a preferential COX-2 inhibitor, and aspirin is a selective COX-1 inhibitor with a distinct mechanism that irreversibly inhibits substrate binding. Because blood cells, including platelets and white blood cells, also contain COX-1, 11C-PS13 uptake inhibition from blood cells was measured in vitro and ex vivo (i.e., using blood obtained during PET scanning). Results: High 11C-PS13 uptake was observed in major organs with high COX-1 density, including the spleen, lungs, kidneys, and gastrointestinal tract. Ketoprofen (1-75 mg orally) blocked uptake in these organs far more effectively than did celecoxib (100-400 mg orally). On the basis of the plasma concentration to inhibit 50% of the maximum radioligand binding in the spleen (in vivo IC 50), ketoprofen (<0.24 μM) was more than 10-fold more potent than celecoxib (>2.5 μM) as a COX-1 inhibitor, consistent with the in vitro potencies of these drugs for inhibiting COX-1. Blockade of 11C-PS13 uptake from blood cells acquired during the PET scans mirrored that in organs of the body. Aspirin (972-1,950 mg orally) blocked such a small percentage of uptake that its in vivo IC 50 could not be determined. Conclusion: 11C-PS13 selectively binds to COX-1 in humans and can measure the in vivo potency of nonsteroidal antiinflammatory drugs that competitively inhibit arachidonic acid binding to COX-1. These in vivo studies, which reflect the net effect of drug absorption and metabolism in all organs of the body, demonstrated that ketoprofen had unexpectedly high potency, that celecoxib substantially inhibited COX-1, and that aspirin acetylation of COX-1 did not block binding of the representative nonsteroidal inhibitor 11C-PS13.
Collapse
Affiliation(s)
- Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and,Department of Psychiatry and Behavioral Health, Stony Brook University School of Medicine, Stony Brook, New York
| | - Fernanda Juarez Anaya
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Lester S. Manly
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jae-Hoon Lee
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jinsoo Hong
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Stal Shrestha
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Katharine Henry
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jose A. Montero Santamaria
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - H. Umesha Shetty
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Sami S. Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Robert B. Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| |
Collapse
|
7
|
Yamamoto Y. [Development of Novel COX-2 Imaging Agents for the Diagnosis of Brain Lesions]. YAKUGAKU ZASSHI 2023; 143:983-987. [PMID: 38044113 DOI: 10.1248/yakushi.23-00109] [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] [Indexed: 12/05/2023]
Abstract
Cyclooxygenase-2 (COX-2) has attracted attention as a biomarker for neurodegenerative brain diseases. The aim of this study was to develop a COX-2 imaging agent for positron emission tomography (PET) that binds to and emits radiation from COX-2 in the central nervous system to diagnose brain lesions related to COX-2. To this end, the development of PET imaging probes by derivatizing non-steroidal anti-inflammatory drugs that bind to COX-2 was investigated. Herein, we present the findings of a series of studies on indomethacin and nimesulide derivatives. All five 11C-labeled indomethacin derivatives showed low brain uptake and were rapidly metabolized in vivo, indicating that they are inadequate COX-2 imaging agents. However, the evaluation of 11C-labeled indomethacin derivatives revealed an inverse relationship between the amount taken up by the brain and the lipophilicity of the compound, and that P-glycoprotein (P-gp) may be responsible for the low brain uptake of 11C-labeled indomethacin derivatives. To overcome the problems associated with 11C-labeled indomethacin derivatives, nimesulide was selected as a novel COX-2 imaging agent. Although the nimesulide derivatives were less lipophilic and unaffected by P-gp, all three 11C-labeled nimesulide derivatives showed low brain uptake and were rapidly metabolized. However, the 11C-labeled nimesulide derivatives were partially useful as brain-targeted COX-2 imaging agents because they bound specifically to COX-2 in the brain of mice and successfully imaged the regional brain distribution associated with COX-2. In the development of COX-2 imaging agents, in vivo stability of the compounds is a future objective.
Collapse
Affiliation(s)
- Yumi Yamamoto
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology
| |
Collapse
|
8
|
Kaur J, Bhardwaj A, Wuest F. Fluorine-18 Labelled Radioligands for PET Imaging of Cyclooxygenase-2. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123722. [PMID: 35744851 PMCID: PMC9227202 DOI: 10.3390/molecules27123722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 11/18/2022]
Abstract
Molecular imaging probes enable the early and accurate detection of disease-specific biomarkers and facilitate personalized treatment of many chronic diseases, including cancer. Among current clinically used functional imaging modalities, positron emission tomography (PET) plays a significant role in cancer detection and in monitoring the response to therapeutic interventions. Several preclinical and clinical studies have demonstrated the crucial involvement of cyclooxygenase-2 (COX-2) isozyme in cancer development and progression, making COX-2 a promising cancer biomarker. A variety of COX-2-targeting PET radioligands has been developed based on anti-inflammatory drugs and selective COX-2 inhibitors. However, many of those suffer from non-specific binding and insufficient metabolic stability. This article highlights examples of COX-2-targeting PET radioligands labelled with the short-lived positron emitter 18F, including radiosynthesis and PET imaging studies published in the last decade (2012–2021).
Collapse
Affiliation(s)
- Jatinder Kaur
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada;
- Correspondence: (J.K.); (F.W.)
| | - Atul Bhardwaj
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada;
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Frank Wuest
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada;
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 1Z2, Canada
- Correspondence: (J.K.); (F.W.)
| |
Collapse
|
9
|
Kenou BV, Manly LS, Rubovits SB, Umeozulu SA, Van Buskirk MG, Zhang AS, Pike VW, Zanotti-Fregonara P, Henter ID, Innis RB. Cyclooxygenases as Potential PET Imaging Biomarkers to Explore Neuroinflammation in Dementia. J Nucl Med 2022; 63:53S-59S. [PMID: 35649646 DOI: 10.2967/jnumed.121.263199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/12/2022] [Indexed: 12/18/2022] Open
Abstract
The most frequently studied target of neuroinflammation using PET is 18-kDa translocator protein, but its limitations have spurred the molecular imaging community to find more promising targets. This article reviews the development of PET radioligands for cyclooxygenase (COX) subtypes 1 and 2, enzymes that catalyze the production of inflammatory prostanoids in the periphery and brain. Although both isozymes produce the same precursor compound, prostaglandin H2, they have distinct functions based on their differential cellular localization in the periphery and brain. For example, COX-1 is located primarily in microglia, a resident inflammatory cell in the brain whose role in producing inflammatory cytokines is well documented. In contrast, COX-2 is located primarily in neurons and can be markedly upregulated by inflammatory and excitatory stimuli, but its functions are poorly understood. This article reviews these 2 isozymes as biomarkers of neuroinflammation, as well as the radioligands that have recently been developed to image them in animals and humans. To place this work into context, the properties of COX-1 and COX-2 are compared with 18-kDa translocator protein, with special consideration of their application in Alzheimer disease as a representative neurodegenerative disorder.
Collapse
Affiliation(s)
- Bruny V Kenou
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Lester S Manly
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sara B Rubovits
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Somachukwu A Umeozulu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Maia G Van Buskirk
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Andrea S Zhang
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
10
|
Boyle AJ, Narvaez A, Tong J, Zoghbi SS, Pike VW, Innis RB, Vasdev N. Repurposing [ 11C]MC1 for PET Imaging of Cyclooxygenase-2 in Colorectal Cancer Xenograft Mouse Models. Mol Imaging Biol 2022; 24:365-370. [PMID: 34766247 PMCID: PMC9670325 DOI: 10.1007/s11307-021-01675-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE Cyclooxygenase-2 (COX-2) is a target for inflammation and colorectal cancer (CRC). This study evaluated the COX-2 neuro-PET radiopharmaceutical, [11C]MC1, in CRC xenograft mice. PROCEDURES [11C]MC1 was evaluated in ICRscid mice with HT-29 and HCT-116 CRC xenografts, with high and low COX-2 expression, respectively, by immunohistochemistry, cellular uptake, dynamic PET/MR imaging, ex vivo biodistribution, and radiometabolite analysis. RESULTS HT-29 xenografts were well visualized with [11C]MC1 using PET/MR. Time-activity curves revealed steady tumor radioactivity accumulation in HT-29 xenografts that plateaued from 40 to 60 min (3.07 ± 0.65 %ID/g) and was significantly reduced by pre-treatment with MC1 or celecoxib (1.62 ± 0.29 and 1.18 ± 0.21 %ID/g, respectively, p = 0.045 and p = 0.005). Radiometabolite analysis showed that [11C]MC1 accounted for >90 % of tumor radioactivity, with <10 % in plasma, at 40 min post-injection of the radiotracer. CONCLUSIONS [11C]MC1 is a promising PET imaging agent for COX-2 in CRC and translation for cancer research should be considered.
Collapse
Affiliation(s)
- Amanda J Boyle
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.
| | - Andrea Narvaez
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Junchao Tong
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada
| | - Sami S Zoghbi
- National Institute of Mental Health, Bethesda, MD, USA
| | - Victor W Pike
- National Institute of Mental Health, Bethesda, MD, USA
| | | | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, M5T 1R8, Canada.
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
11
|
Khan H, Sharma K, Kumar A, Kaur A, Singh TG. Therapeutic implications of cyclooxygenase (COX) inhibitors in ischemic injury. Inflamm Res 2022; 71:277-292. [PMID: 35175358 DOI: 10.1007/s00011-022-01546-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/19/2022] [Accepted: 01/22/2022] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Ischemia-reperfusion injury (IRI) is the inexplicable aggravation of cellular dysfunction that results in blood flow restoration to previously ischemic tissues. COX mediates the oxidative conversion of AA to various prostaglandins and thromboxanes, which are involved in various physiological and pathological processes. In the pathophysiology of I/R injuries, COX has been found to play an important role. I/R injuries affect most vital organs and are characterized by inflammation, oxidative stress, cell death, and apoptosis, leading to morbidity and mortality. MATERIALS AND METHODS A systematic literature review of Bentham, Scopus, PubMed, Medline, and EMBASE (Elsevier) databases was carried out to understand the Nature and mechanistic interventions of the Cyclooxygenase modulations in ischemic injury. Here, we have discussed the COX Physiology and downstream signalling pathways modulated by COX, e.g., Camp Pathway, Peroxisome Proliferator-Activated Receptor Activity, NF-kB Signalling, PI3K/Akt Signalling in ischemic injury. CONCLUSION This review will discuss the various COX types, specifically COX-1 and COX-2, which are involved in developing I/R injury in organs such as the brain, spinal cord, heart, kidney, liver, and intestine.
Collapse
Affiliation(s)
- Heena Khan
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Kunal Sharma
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Amit Kumar
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Amarjot Kaur
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India
| | - Thakur Gurjeet Singh
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, 140401, India.
| |
Collapse
|
12
|
Yamamoto Y, Tago T, Toyohara J, Saito Y, Yamamoto F. Radiosynthesis and in Vivo and ex Vivo Evaluation of Isomeric [ 11C]methoxy Analogs of Nimesulide as Brain Cyclooxygenase-2-Targeted Imaging Agents. Biol Pharm Bull 2022; 45:94-103. [PMID: 34980783 DOI: 10.1248/bpb.b21-00608] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous studies identified that nimesulide analogs which bear a methoxy substituent at the para-position of the phenyl ring could be potential radiotracer candidates for detecting disorders related to cyclooxygenase-2 (COX-2) expression and activity in vivo using positron emission tomography (PET) in the brain. The present study was conducted to evaluate the in vivo characteristics of 11C-labeled para-methoxy nimesulide ([11C]1d) as a brain COX-2-targeted imaging agent compared to other isomeric methoxy analogs of nimesulide ([11C]1b and [11C]1c). [11C]1b-d were synthesized with reasonable yield and purity by the methylation of the O-desmethyl precursor with [11C]methyl triflate in the presence of NaOH at room temperature. We performed in vivo biodistribution analysis, brain PET imaging, ex vivo autoradiography, and metabolite analysis in mice. The uptake of [11C]1b-d was lower in the brain than in other tissues, including in the blood, and both [11C]1c and [11C]1d were rapidly metabolized. However, [11C]1d showed a small, but significant, specific signal and heterogeneous distribution in the brain. In vivo evaluation suggested that [11C]1d might correlate with COX-2 expression in the brain. Given its instability in vivo, [11C]1d seems unsuitable as a brain-COX-2 radioimaging agent. Further structural refinement of these radiotracers is necessary to enhance their uptake in the brain and to achieve sufficient metabolic stability.
Collapse
Affiliation(s)
- Yumi Yamamoto
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University.,Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology
| | - Tetsuro Tago
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology
| | - Jun Toyohara
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology
| | - Yohei Saito
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
| | - Fumihiko Yamamoto
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
| |
Collapse
|
13
|
Brumberg J, Varrone A. New PET radiopharmaceuticals for imaging CNS diseases. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
14
|
Chen Z, Haider A, Chen J, Xiao Z, Gobbi L, Honer M, Grether U, Arnold SE, Josephson L, Liang SH. The Repertoire of Small-Molecule PET Probes for Neuroinflammation Imaging: Challenges and Opportunities beyond TSPO. J Med Chem 2021; 64:17656-17689. [PMID: 34905377 PMCID: PMC9094091 DOI: 10.1021/acs.jmedchem.1c01571] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Neuroinflammation is an adaptive response of the central nervous system to diverse potentially injurious stimuli, which is closely associated with neurodegeneration and typically characterized by activation of microglia and astrocytes. As a noninvasive and translational molecular imaging tool, positron emission tomography (PET) could provide a better understanding of neuroinflammation and its role in neurodegenerative diseases. Ligands to translator protein (TSPO), a putative marker of neuroinflammation, have been the most commonly studied in this context, but they suffer from serious limitations. Herein we present a repertoire of different structural chemotypes and novel PET ligand design for classical and emerging neuroinflammatory targets beyond TSPO. We believe that this Perspective will support multidisciplinary collaborations in academic and industrial institutions working on neuroinflammation and facilitate the progress of neuroinflammation PET probe development for clinical use.
Collapse
Affiliation(s)
- Zhen Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Ahmed Haider
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Jiahui Chen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Zhiwei Xiao
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Luca Gobbi
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Michael Honer
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Uwe Grether
- Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland
| | - Steven E. Arnold
- Department of Neurology and the Massachusetts Alzheimer’s Disease Research Center, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, Massachusetts 02129, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| | - Steven H. Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, United States
| |
Collapse
|
15
|
NRM 2021 Abstract Booklet. J Cereb Blood Flow Metab 2021; 41:11-309. [PMID: 34905986 PMCID: PMC8851538 DOI: 10.1177/0271678x211061050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
16
|
Preliminary Assessment of the Anti-inflammatory Activity of New Structural Honokiol Analogs with a 4'- O-(2-Fluoroethyl) Moiety and the Potential of Their 18F-Labeled Derivatives for Neuroinflammation Imaging. Molecules 2021; 26:molecules26216630. [PMID: 34771039 PMCID: PMC8587714 DOI: 10.3390/molecules26216630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/24/2021] [Accepted: 10/28/2021] [Indexed: 01/31/2023] Open
Abstract
Neolignans honokiol and 4′-O-methylhonokiol (MH) and their derivatives have pronounced anti-inflammatory activity, as evidenced by numerous pharmacological studies. Literature data suggested that cyclooxygenase type 2 (COX-2) may be a target for these compounds in vitro and in vivo. Recent studies of [11C]MPbP (4′-[11C]methoxy-5-propyl-1,1′-biphenyl-2-ol) biodistribution in LPS (lipopolysaccharide)-treated rats have confirmed the high potential of MH derivatives for imaging neuroinflammation. Here, we report the synthesis of four structural analogs of honokiol, of which 4′-(2-fluoroethoxy)-2-hydroxy-5-propyl-1, 1′-biphenyl (F-IV) was selected for labeling with fluorine-18 (T1/2 = 109.8 min) due to its high anti-inflammatory activity confirmed by enzyme immunoassays (EIA) and neuromorphological studies. The high inhibitory potency of F-IV to COX-2 and its moderate lipophilicity and chemical stability are favorable factors for the preliminary evaluation of the radioligand [18F]F-IV in a rodent model of neuroinflammation. [18F]F-IV was prepared with good radiochemical yield and high molar activity and radiochemical purity by 18F-fluoroethylation of the precursor with Boc-protecting group (15) with [18F]2-fluoro-1-bromoethane ([18F]FEB). Ex vivo biodistribution studies revealed a small to moderate increase in radioligand uptake in the brain and peripheral organs of LPS-induced rats compared to control animals. Pretreatment with celecoxib resulted in significant blocking of radioactivity uptake in the brain (pons and medulla), heart, lungs, and kidneys, indicating that [18F]F-IV is likely to specifically bind to COX-2 in a rat model of neuroinflammation. However, in comparison with [11C]MPbP, the new radioligand showed decreased brain uptake in LPS rats and high retention in the blood pool, which apparently could be explained by its high plasma protein binding. We believe that the structure of [18F]F-IV can be optimized by replacing the substituents in the biphenyl core to eliminate these disadvantages and develop new radioligands for imaging activated microglia.
Collapse
|
17
|
Zhou X, Ji B, Seki C, Nagai Y, Minamimoto T, Fujinaga M, Zhang MR, Saito T, Saido TC, Suhara T, Kimura Y, Higuchi M. PET imaging of colony-stimulating factor 1 receptor: A head-to-head comparison of a novel radioligand, 11C-GW2580, and 11C-CPPC, in mouse models of acute and chronic neuroinflammation and a rhesus monkey. J Cereb Blood Flow Metab 2021; 41:2410-2422. [PMID: 33757319 PMCID: PMC8393303 DOI: 10.1177/0271678x211004146] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Colony-stimulating factor 1 receptor (CSF1R) is a specific biomarker for microglia. In this study, we developed a novel PET radioligand for CSF1R, 11C-GW2580, and compared it to a reported CSF1R tracer, 11C-CPPC, in mouse models of acute and chronic neuroinflammation and a rhesus monkey. Dynamic 11C-GW2580- and 11C-CPPC-PET images were quantified by reference tissue-based models and standardized uptake value ratio. Both tracers exhibited increased uptake in the lesioned striata of lipopolysaccharide-injected mice and in the forebrains of AppNL-G-F/NL-G-F-knock-in mice, spatially in agreement with an increased 18-kDa translocator protein radioligand retention. Moreover, 11C-GW2580 captured changes in CSF1R availability more sensitively than 11C-CPPC, with a larger dynamic range and a smaller inter-individual variability, in these model animals. PET imaging of CSF1R in a rhesus monkey displayed moderate-to-high tracer retention in the brain at baseline. Homologous blocker (i. e. unlabeled tracer) treatment reduced the uptake of 11C-GW2580 by ∼30% in all examined brain regions except for centrum semi-ovale white matter, but did not affect the retention of 11C-CPPC. In summary, our results demonstrated that 11C-GW2580-PET captured inflammatory microgliosis in the mouse brain with higher sensitivity than a reported radioligand, and displayed saturable binding in the monkey brain, potentially providing an imaging-based quantitative biomarker for reactive microgliosis.
Collapse
Affiliation(s)
- Xiaoyun Zhou
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Bin Ji
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Chie Seki
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yuji Nagai
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Takafumi Minamimoto
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masayuki Fujinaga
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Ming-Rong Zhang
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Japan.,Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, Nagoya, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Japan
| | - Tetsuya Suhara
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yasuyuki Kimura
- Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Makoto Higuchi
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| |
Collapse
|
18
|
Ghazanfari N, van Waarde A, Dierckx RAJO, Doorduin J, de Vries EFJ. Is cyclooxygenase-1 involved in neuroinflammation? J Neurosci Res 2021; 99:2976-2998. [PMID: 34346520 PMCID: PMC9542093 DOI: 10.1002/jnr.24934] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/08/2021] [Accepted: 07/13/2021] [Indexed: 12/15/2022]
Abstract
Purpose: Reactive microglia are an important hallmark of neuroinflammation. Reactive microglia release various inflammatory mediators, such as cytokines, chemokines, and prostaglandins, which are produced by enzymes like cyclooxygenases (COX). The inducible COX‐2 subtype has been associated with inflammation, whereas the constitutively expressed COX‐1 subtype is generally considered as a housekeeping enzyme. However, recent evidence suggests that COX‐1 can also be upregulated and may play a prominent role in the brain during neuroinflammation. In this review, we summarize the evidence that supports this involvement of COX‐1. Methods: Five databases were used to retrieve relevant studies that addressed COX‐1 in the context of neuroinflammation. The search resulted in 32 articles, describing in vitro, in vivo, post mortem, and in vivo imaging studies that specifically investigated the COX‐1 isoform under such conditions. Results: Reviewed literature generally indicated that the overexpression of COX‐1 was induced by an inflammatory stimulus, which resulted in an increased production of prostaglandin E2. The pharmacological inhibition of COX‐1 was shown to suppress the induction of inflammatory mediators like prostaglandin E2. Positron emission tomography (PET) imaging studies in animal models confirmed the overexpression of COX‐1 during neuroinflammation. The same imaging method, however, could not detect any upregulation of COX‐1 in patients with Alzheimer's disease. Conclusion: Taken together, studies in cultured cells and living rodents suggest that COX‐1 is involved in neuroinflammation. Most postmortem studies on human brains indicate that the concentration of COX‐1‐expressing microglial cells is increased near sites of inflammation. However, evidence for the involvement of COX‐1 in neuroinflammation in the living human brain is still largely lacking.
Collapse
Affiliation(s)
- Nafiseh Ghazanfari
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Erik F J de Vries
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| |
Collapse
|
19
|
Beaino W, Janssen B, Vugts DJ, de Vries HE, Windhorst AD. Towards PET imaging of the dynamic phenotypes of microglia. Clin Exp Immunol 2021; 206:282-300. [PMID: 34331705 PMCID: PMC8561701 DOI: 10.1111/cei.13649] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 02/06/2023] Open
Abstract
There is increasing evidence showing the heterogeneity of microglia activation in neuroinflammatory and neurodegenerative diseases. It has been hypothesized that pro‐inflammatory microglia are detrimental and contribute to disease progression, while anti‐inflammatory microglia play a role in damage repair and remission. The development of therapeutics targeting the deleterious glial activity and modulating it into a regenerative phenotype relies heavily upon a clearer understanding of the microglia dynamics during disease progression and the ability to monitor therapeutic outcome in vivo. To that end, molecular imaging techniques are required to assess microglia dynamics and study their role in disease progression as well as to evaluate the outcome of therapeutic interventions. Positron emission tomography (PET) is such a molecular imaging technique, and provides unique capabilities for non‐invasive quantification of neuroinflammation and has the potential to discriminate between microglia phenotypes and define their role in the disease process. However, several obstacles limit the possibility for selective in vivo imaging of microglia phenotypes mainly related to the poor characterization of specific targets that distinguish the two ends of the microglia activation spectrum and lack of suitable tracers. PET tracers targeting translocator protein 18 kDa (TSPO) have been extensively explored, but despite the success in evaluating neuroinflammation they failed to discriminate between microglia activation statuses. In this review, we highlight the current knowledge on the microglia phenotypes in the major neuroinflammatory and neurodegenerative diseases. We also discuss the current and emerging PET imaging targets, the tracers and their potential in discriminating between the pro‐ and anti‐inflammatory microglia activation states.
Collapse
Affiliation(s)
- Wissam Beaino
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Bieneke Janssen
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Danielle J Vugts
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, MS Center Amsterdam, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| | - Albert D Windhorst
- Department of Radiology and Nuclear Medicine, Tracer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Amsterdam, the Netherlands
| |
Collapse
|
20
|
Wahl RL, Chareonthaitawee P, Clarke B, Drzezga A, Lindenberg L, Rahmim A, Thackeray J, Ulaner GA, Weber W, Zukotynski K, Sunderland J. Mars Shot for Nuclear Medicine, Molecular Imaging, and Molecularly Targeted Radiopharmaceutical Therapy. J Nucl Med 2021; 62:6-14. [PMID: 33334911 DOI: 10.2967/jnumed.120.253450] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023] Open
Abstract
The Society of Nuclear Medicine and Molecular Imaging created the Value Initiative in 2017 as a major component of its strategic plan to further demonstrate the value of molecular imaging and molecularly targeted radiopharmaceutical therapy to patients, physicians, payers, and funding agencies. The research and discovery domain, 1 of 5 under the Value Initiative, has a goal of advancing the research and development of diagnostic and therapeutic nuclear medicine. Research and discovery efforts and achievements are essential to ensure a bright future for NM and to translate science to practice. Given the remarkable progress in the field, leaders from the research and discovery domain and society councils identified 5 broad areas of opportunity with potential for substantive growth and clinical impact. This article discusses these 5 growth areas, identifying specific areas of particularly high importance for future study and development. As there was an understanding that goals should be both visionary yet achievable, this effort was called the Mars shot for nuclear medicine.
Collapse
Affiliation(s)
- Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University St. Louis, Missouri
| | | | - Bonnie Clarke
- Research and Discovery, Society of Nuclear Medicine and Molecular Imaging, Reston, Virginia
| | - Alexander Drzezga
- Department of Nuclear Medicine, University of Cologne, Cologne, Germany, German Center for Neurodegenerative Diseases, Bonn-Cologne, Germany, and Institute of Neuroscience and Medicine, Molecular Organization of the Brain, Forschungszentrum Jülich, Jülich, Germany
| | - Liza Lindenberg
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Arman Rahmim
- Departments of Radiology and Physics, University of British Columbia, Vancouver, British Columbia, Canada; Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, British Columbia, Canada
| | - James Thackeray
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Gary A Ulaner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, and Molecular Imaging and Therapy, Hoag Cancer Center, Newport Beach, California
| | - Wolfgang Weber
- Department of Nuclear Medicine, Technical University Munich, Munich, Germany
| | - Katherine Zukotynski
- Departments of Medicine and Radiology, McMaster University, Hamilton, Ontario, Canada; and
| | - John Sunderland
- Departments of Radiology and Physics, University of Iowa, Iowa City, Iowa
| |
Collapse
|
21
|
Taddei C, Morse CL, Kim MJ, Liow JS, Montero Santamaria J, Zhang A, Manly LS, Zanotti-Fregonara P, Gladding RL, Zoghbi SS, Innis RB, Pike VW. Synthesis of [ 18F]PS13 and Evaluation as a PET Radioligand for Cyclooxygenase-1 in Monkey. ACS Chem Neurosci 2021; 12:517-530. [PMID: 33491441 PMCID: PMC9021884 DOI: 10.1021/acschemneuro.0c00737] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cyclooxygenase-1 (COX-1) and its isozyme COX-2 are key enzymes in the syntheses of prostanoids. Imaging of COX-1 and COX-2 selective radioligands with positron emission tomography (PET) may clarify how these enzymes are involved in inflammatory conditions and assist in the discovery of improved anti-inflammatory drugs. We have previously labeled the selective high-affinity COX-1 ligand, 1,5-bis(4-methoxyphenyl)-3-(2,2,2-trifluoroethoxy)-1H-1,2,4-triazole (PS13), with carbon-11 (t1/2 = 20.4 min). This radioligand ([11C]PS13) has been successful for PET imaging of COX-1 in monkey and human brain and in periphery. [11C]PS13 is being used in clinical investigations. Alternative labeling of PS13 with fluorine-18 (t1/2 = 109.8 min) is desirable to provide a longer-lived radioligand in high activity that might be readily distributed among imaging centers. However, labeling of PS13 in its 1,1,1-trifluoroethoxy group is a radiochemical challenge. Here we assess two labeling approaches based on nucleophilic addition of cyclotron-produced [18F]fluoride ion to gem-difluorovinyl precursors, either to label PS13 in one step or to produce [18F]2,2,2-trifluoroethyl p-toluenesulfonate for labeling a hydroxyl precursor. From the latter two-step approach, we obtained [18F]PS13 ready for intravenous injection in a decay-corrected radiochemical yield of 7.9% and with a molar activity of up to 7.9 GBq/μmol. PET imaging of monkey brain with [18F]PS13 shows that this radioligand can specifically image and quantify COX-1 without radiodefluorination but with some radioactivity uptake in skull, ascribed to red bone marrow. The development of a new procedure for labeling PS13 with fluorine-18 at a higher molar activity is, however, desirable to suppress occupancy of COX-1 by carrier at baseline.
Collapse
Affiliation(s)
- Carlotta Taddei
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Jose Montero Santamaria
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Andrea Zhang
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Lester S Manly
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Robert L Gladding
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Abstract
Initial reports supporting the possibility of inflammation in the brain in obsessive-compulsive disorder (OCD) evolved from the models of Sydenham's Chorea, and Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS), which implicated excessive autoimmune responses following exposure to group A B-hemolytic streptococcal infections. Subsequently, this model was expanded to Pediatric Autoimmune Neuropsychiatric Syndrome (PANS) which applied the same concept but included other infections. A critical shortcoming of this model was that it was attributable to a small minority of OCD cases. The relationship between inflammation and OCD was more broadly demonstrated through translocator protein (TSPO) positron emission tomography imaging, a method that detects gliosis, an important component of brain inflammation, in neuropsychiatric diseases, including morphological activation and proliferation of microglia and to some extent astroglia. This method identified greater TSPO binding in the cortico-striatal-thalamo-cortical circuit in OCD, providing a direct brain measure of an important component of inflammation. To identify OCD cases with prominent elevations in TSPO binding in clinical research settings with lower cost peripheral markers, a promising approach is to apply blood serum biomarkers of inflammatory molecules produced by activated microglia and astroglia (gliosis). Such measures may aid stratification in future clinical trials. Several inflammatory-modifying interventions, including celecoxib, minocycline, and n-acetylcysteine, have been tested as treatments in randomized double-blind placebo controlled clinical trials and there is a tendency toward positive results, although these medications are not optimized for brain penetration and sample sizes for most trials were small. Future clinical trials of medications that target gliosis in OCD should apply larger sample sizes, ideally incorporating stratification approaches to enrich samples for the presence of gliosis.
Collapse
|
24
|
Solnes LB, Jacobs AH, Coughlin JM, Du Y, Goel R, Hammoud DA, Pomper MG. Central Nervous System Molecular Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00088-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
25
|
Identifying Musculoskeletal Pain Generators Using Molecular Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00076-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
26
|
Meyer JH, Cervenka S, Kim MJ, Kreisl WC, Henter ID, Innis RB. Neuroinflammation in psychiatric disorders: PET imaging and promising new targets. Lancet Psychiatry 2020; 7:1064-1074. [PMID: 33098761 PMCID: PMC7893630 DOI: 10.1016/s2215-0366(20)30255-8] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/14/2023]
Abstract
Neuroinflammation is a multifaceted physiological and pathophysiological response of the brain to injury and disease. Given imaging findings of 18 kDa translocator protein (TSPO) and the development of radioligands for other inflammatory targets, PET imaging of neuroinflammation is at a particularly promising stage. This Review critically evaluates PET imaging results of inflammation in psychiatric disorders, including major depressive disorder, schizophrenia and psychosis disorders, substance use, and obsessive-compulsive disorder. We also consider promising new targets that can be measured in the brain, such as monoamine oxidase B, cyclooxygenase-1 and cyclooxygenase-2, colony stimulating factor 1 receptor, and the purinergic P2X7 receptor. Thus far, the most compelling TSPO imaging results have arguably been found in major depressive disorder, for which consistent increases have been observed, and in schizophrenia and psychosis, for which patients show reduced TSPO levels. This pattern highlights the importance of validating brain biomarkers of neuroinflammation for each condition separately before moving on to patient stratification and treatment monitoring trials.
Collapse
Affiliation(s)
- Jeffrey H Meyer
- Campbell Family Mental Health Research Institute, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm, Sweden
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - William C Kreisl
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA.
| |
Collapse
|
27
|
Attwells S, Setiawan E, Rusjan PM, Xu C, Hutton C, Rafiei D, Varughese B, Kahn A, Kish SJ, Vasdev N, Houle S, Meyer JH. Translocator Protein Distribution Volume Predicts Reduction of Symptoms During Open-Label Trial of Celecoxib in Major Depressive Disorder. Biol Psychiatry 2020; 88:649-656. [PMID: 32402468 DOI: 10.1016/j.biopsych.2020.03.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 03/05/2020] [Accepted: 03/11/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Gliosis is common among neuropsychiatric diseases, but the relationship between gliosis and response to therapeutics targeting effects of gliosis is largely unknown. Translocator protein total distribution volume (TSPO VT), measured with positron emission tomography, mainly reflects gliosis in neuropsychiatric disease. Here, the primary objective was to determine whether TSPO VT in the prefrontal cortex (PFC) and anterior cingulate cortex (ACC) predicts reduction of depressive symptoms following open-label celecoxib administration in treatment-resistant major depressive disorder. METHODS A total of 41 subjects with treatment-resistant major depressive disorder underwent one [18F]FEPPA positron emission tomography scan to measure PFC and ACC TSPO VT. Open-label oral celecoxib (200 mg, twice daily) was administered for 8 weeks. Change in symptoms was measured with the 17-item Hamilton Depression Rating Scale (HDRS). RESULTS Cumulative mean change in HDRS scores between 0 and 8 weeks of treatment was plotted against PFC and ACC TSPO VT, showing a significant nonlinear relationship. At low TSPO VT values, there was no reduction in HDRS scores, but as TSPO VT values increased, there was a reduction in HDRS scores that then plateaued. This was modeled with a 4-parameter sigmoidal model in which PFC and ACC TSPO VT accounted for 84% and 92% of the variance, respectively. CONCLUSIONS Celecoxib administration in the presence of gliosis labeled by TSPO VT is associated with greater reduction of symptoms. Given the predictiveness of TSPO VT on symptom reduction, this personalized medicine approach of matching a marker of gliosis to medication targeting effects of gliosis should be applied in early development of novel therapeutics, in particular for treatment-resistant major depressive disorder.
Collapse
Affiliation(s)
- Sophia Attwells
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Elaine Setiawan
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Pablo M Rusjan
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Cynthia Xu
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Celeste Hutton
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Dorsa Rafiei
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Benjamin Varughese
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Alan Kahn
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Stephen J Kish
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Neil Vasdev
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Sylvain Houle
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Jeffrey H Meyer
- Brain Health Imaging Centre and Campbell Family Mental Health Research Institute, the Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
28
|
Boyle AJ, Tong J, Zoghbi SS, Pike VW, Innis RB, Vasdev N. Repurposing 11C-PS13 for PET Imaging of Cyclooxygenase-1 in Ovarian Cancer Xenograft Mouse Models. J Nucl Med 2020; 62:665-668. [DOI: 10.2967/jnumed.120.249367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/17/2020] [Indexed: 11/16/2022] Open
|
29
|
Kumar JSD, Prabhakaran J, Molotkov A, Sattiraju A, Kim J, Doubrovin M, Mann JJ, Mintz A. Radiosynthesis and evaluation of [ 18F]FMTP, a COX-2 PET ligand. Pharmacol Rep 2020; 72:1433-1440. [PMID: 32632914 DOI: 10.1007/s43440-020-00124-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 01/07/2023]
Abstract
BACKGROUND The upregulation of cyclooxygenase-2 (COX-2) is involved in neuroinflammation associated with many neurological diseases as well as cancers of the brain. Outside the brain, inflammation and COX-2 induction contribute to the pathogenesis of pain, arthritis, acute allograft rejection, and in response to infections, tumors, autoimmune disorders, and injuries. Herein, we report the radiochemical synthesis and evaluation of [18F]6-fluoro-2-(4-(methylsulfonyl)phenyl)-N-(thiophen-2-ylmethyl)pyrimidin-4-amine ([18F]FMTP), a high-affinity COX-2 inhibitor, by cell uptake and PET imaging studies. METHODS The radiochemical synthesis of [18F]FMTP was optimized using chlorine to fluorine displacement method, by reacting [18F]fluoride/K222/K2CO3 with the precursor molecule. Cellular uptake studies of [18F]FMTP was performed in COX-2 positive BxPC3 and COX-2 negative PANC-1 cell lines with unlabeled FMTP as well as celecoxib to define specific binding agents. Dynamic microPET image acquisitionwas performed in anesthetized nude mice (n = 3), lipopolysaccharide (LPS) induced neuroinflammation mice (n = 4), and phosphate-buffered saline (PBS) administered control mice (n = 4) using a Trifoil microPET/CT for a scan period of 60 min. RESULTS A twofold higher binding of [18F]FMTP was found in COX-2 positive BxPC3 cells compared with COX-2 negative PANC-1 cells. The radioligand did not show specific binding to COX-2 negative PANC-1 cells. MicroPET imaging in wild-type mice indicated blood-brain barrier (BBB) penetration and fast washout of [18F]FMTP in the brain, likely due to the low constitutive COX-2 expression in the normal brain. In contrast, a ~ twofold higher uptake of the radioligand was found in LPS-induced mice brain than PBS treated control mice. CONCLUSIONS Specific binding to COX-2 in BxPC3 cell lines, BBB permeability, and increased brain uptake in neuroinflammation mice qualifies [18F]FMTP as a potential PET tracer for studying inflammation.
Collapse
Affiliation(s)
- J S Dileep Kumar
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, Manhattan, NY, USA.
| | - Jaya Prabhakaran
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, Manhattan, NY, USA.,Department of Psychiatry, Columbia University Medical Center, Manhattan, NY, USA
| | - Andrei Molotkov
- Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA
| | - Anirudh Sattiraju
- Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA
| | - Jongho Kim
- Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA
| | - Mikhail Doubrovin
- Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA
| | - J John Mann
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, Manhattan, NY, USA.,Department of Psychiatry, Columbia University Medical Center, Manhattan, NY, USA.,Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA
| | - Akiva Mintz
- Department of Radiology, Columbia University Medical Center, Manhattan, NY, USA.
| |
Collapse
|
30
|
Jain P, Chaney AM, Carlson ML, Jackson IM, Rao A, James ML. Neuroinflammation PET Imaging: Current Opinion and Future Directions. J Nucl Med 2020; 61:1107-1112. [PMID: 32620705 DOI: 10.2967/jnumed.119.229443] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammation is a key pathologic hallmark of numerous neurologic diseases, however, its exact role in vivo is yet to be fully understood. PET imaging enables investigation, quantification, and tracking of different neuroinflammation biomarkers in living subjects longitudinally. One such biomarker that has been imaged extensively using PET is translocator protein 18 kDa (TSPO). Although imaging TSPO has yielded valuable clinical data linking neuroinflammation to various neurodegenerative diseases, considerable limitations of TSPO PET have prompted identification of other more cell-specific and functionally relevant biomarkers. This review analyzes the clinical potential of available and emerging PET biomarkers of innate and adaptive immune responses, with mention of exciting future directions for the field.
Collapse
Affiliation(s)
- Poorva Jain
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California
| | - Aisling M Chaney
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California
| | - Mackenzie L Carlson
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California.,Department of Bioengineering, Stanford University, Stanford, California; and
| | - Isaac M Jackson
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California
| | - Anoushka Rao
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California
| | - Michelle L James
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California .,Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| |
Collapse
|
31
|
Kim MJ, Lee JH, Juarez Anaya F, Hong J, Miller W, Telu S, Singh P, Cortes MY, Henry K, Tye GL, Frankland MP, Montero Santamaria JA, Liow JS, Zoghbi SS, Fujita M, Pike VW, Innis RB. First-in-human evaluation of [ 11C]PS13, a novel PET radioligand, to quantify cyclooxygenase-1 in the brain. Eur J Nucl Med Mol Imaging 2020; 47:3143-3151. [PMID: 32399622 DOI: 10.1007/s00259-020-04855-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 05/04/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE This study assessed whether the newly developed PET radioligand [11C]PS13, which has shown excellent in vivo selectivity in previous animal studies, could be used to quantify constitutive levels of cyclooxygenase-1 (COX-1) in healthy human brain. METHODS Brain test-retest scans with concurrent arterial blood samples were obtained in 10 healthy individuals. The one- and unconstrained two-tissue compartment models, as well as the Logan graphical analysis were compared, and test-retest reliability and time-stability of total distribution volume (VT) were assessed. Correlation analyses were conducted between brain regional VT and COX-1 transcript levels provided in the Allen Human Brain Atlas. RESULTS In the brain, [11C]PS13 showed highest uptake in the hippocampus and occipital cortex. The pericentral cortex also showed relatively higher uptake compared with adjacent neocortices. The two-tissue compartment model showed the best fit in all the brain regions, and the results from the Logan graphical analysis were consistent with those from the two-tissue compartment model. VT values showed excellent test-retest variability (range 6.0-8.5%) and good reliability (intraclass correlation coefficient range 0.74-0.87). VT values also showed excellent time-stability in all brain regions, confirming that there was no radiometabolite accumulation and that shorter scans were still able to reliably measure VT. Significant correlation was observed between VT and COX-1 transcript levels (r = 0.82, P = 0.007), indicating that [11C]PS13 binding reflects actual COX-1 density in the human brain. CONCLUSIONS These results from the first-in-human evaluation of the ability of [11C]PS13 to image COX-1 in the brain justifies extending the study to disease populations with neuroinflammation. CLINICAL TRIAL REGISTRATION NCT03324646 at https://clinicaltrials.gov/ . Registered October 30, 2017. Retrospectively registered.
Collapse
Affiliation(s)
- Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA.
| | - Jae-Hoon Lee
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA.,Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Fernanda Juarez Anaya
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Jinsoo Hong
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - William Miller
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Prachi Singh
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Michelle Y Cortes
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Katharine Henry
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - George L Tye
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Michael P Frankland
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Jose A Montero Santamaria
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Masahiro Fujita
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Bldg. 10, Rm B1D43, Bethesda, MD, 20892-1026, USA
| |
Collapse
|
32
|
PET measurement of cyclooxygenase-2 using a novel radioligand: upregulation in primate neuroinflammation and first-in-human study. J Neuroinflammation 2020; 17:140. [PMID: 32359360 PMCID: PMC7195739 DOI: 10.1186/s12974-020-01804-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/03/2020] [Indexed: 02/06/2023] Open
Abstract
Background Cyclooxygenase-2 (COX-2), which is rapidly upregulated by inflammation, is a key enzyme catalyzing the rate-limiting step in the synthesis of several inflammatory prostanoids. Successful positron emission tomography (PET) radioligand imaging of COX-2 in vivo could be a potentially powerful tool for assessing inflammatory response in the brain and periphery. To date, however, the development of PET radioligands for COX-2 has had limited success. Methods The novel PET tracer [11C]MC1 was used to examine COX-2 expression [1] in the brains of four rhesus macaques at baseline and after injection of the inflammogen lipopolysaccharide (LPS) into the right putamen, and [2] in the joints of two human participants with rheumatoid arthritis and two healthy individuals. In the primate study, two monkeys had one LPS injection, and two monkeys had a second injection 33 and 44 days, respectively, after the first LPS injection. As a comparator, COX-1 expression was measured using [11C]PS13. Results COX-2 binding, expressed as the ratio of specific to nondisplaceable uptake (BPND) of [11C]MC1, increased on day 1 post-LPS injection; no such increase in COX-1 expression, measured using [11C]PS13, was observed. The day after the second LPS injection, a brain lesion (~ 0.5 cm in diameter) with high COX-2 density and high BPND (1.8) was observed. Postmortem brain analysis at the gene transcript or protein level confirmed in vivo PET results. An incidental finding in an unrelated monkey found a line of COX-2 positivity along an incision in skull muscle, demonstrating that [11C]MC1 can localize inflammation peripheral to the brain. In patients with rheumatoid arthritis, [11C]MC1 successfully imaged upregulated COX-2 in the arthritic hand and shoulder and apparently in the brain. Uptake was blocked by celecoxib, a COX-2 preferential inhibitor. Conclusions Taken together, these results indicate that [11C]MC1 can image and quantify COX-2 upregulation in both monkey brain after LPS-induced neuroinflammation and in human peripheral tissue with inflammation. Trial registration ClinicalTrials.gov NCT03912428. Registered April 11, 2019.
Collapse
|
33
|
Kiseleva MM, Vaulina DD, Sivak KV, Alexandrov AG, Kuzmich NN, Viktorov NB, Kuznetsova OF, Gomzina NA. Radiosynthesis of a Novel
11
C‐Labeled Derivative of 4’‐
O
‐Methylhonokiol and Its Preliminary Evaluation in an LPS Rat Model of Neuroinflammation. ChemistrySelect 2020. [DOI: 10.1002/slct.201904788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Mariia M Kiseleva
- Research Center of the University Hospital Centre of Québec CityLaval University 2705, boulevard Laurier Québec, QC Canada G1 V 4G2
- Department of Science and Engineering, Mineral, Metallurgical, and Materials EngineeringLaval University 2325 Rue de l'Université Québec, QC Canada QC G1 V 0 A6
| | - Daria D Vaulina
- Laboratory of radiochemistry, N.P. Bechtereva Institute of Human BrainRussian Academy of Science 9, Pavlov street Saint-Petersburg 197376, Russian Federation
| | - Konstantin V Sivak
- Laboratory of pharmaceuticals' safety, Department of pharmaceuticals' preclinical trialsWHO National Influenza Centre of Russia 15/17 Professor Popov street Saint-Petersburg 197376 Russian Federation
| | - Andrey G Alexandrov
- Laboratory of pharmaceuticals' safety, Department of pharmaceuticals' preclinical trialsWHO National Influenza Centre of Russia 15/17 Professor Popov street Saint-Petersburg 197376 Russian Federation
| | - Nikolay N Kuzmich
- Laboratory of pharmaceuticals' safety, Department of pharmaceuticals' preclinical trialsWHO National Influenza Centre of Russia 15/17 Professor Popov street Saint-Petersburg 197376 Russian Federation
- Institute of Biotechnology and Translational medicine, I. M. SechenovFirst Moscow State Medical University, 8 build.2 Trubetskaya street Moscow 119991 Russian Federation
| | - Nikolai B Viktorov
- Department of organic chemistry, Faculty of chemical and biotechnologiesSaint-Petersburg State Institute of Technology, 26 Moskovsky prospect Saint-Petersburg 190013 Russian Federation
| | - Olga F Kuznetsova
- Laboratory of radiochemistry, N.P. Bechtereva Institute of Human BrainRussian Academy of Science 9, Pavlov street Saint-Petersburg 197376, Russian Federation
| | - Natalia A Gomzina
- Laboratory of radiochemistry, N.P. Bechtereva Institute of Human BrainRussian Academy of Science 9, Pavlov street Saint-Petersburg 197376, Russian Federation
| |
Collapse
|
34
|
Hillmer AT, Matuskey D, Huang Y, Nabulsi N, Ropchan J, Carson RE, O'Malley SS, Cosgrove KP. Tobacco Smoking in People Is Not Associated with Altered 18-kDa Translocator Protein Levels: A PET Study. J Nucl Med 2020; 61:1200-1204. [PMID: 32005773 DOI: 10.2967/jnumed.119.237735] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/19/2019] [Indexed: 11/16/2022] Open
Abstract
The effects of tobacco smoking on the immune system of the brain are not well elucidated. Although nicotine is immunosuppressive, other constituents in tobacco smoke have inflammatory effects. PET imaging of the 18-kDa translocator protein (TSPO) provides a biomarker for microglia, the primary immunocompetent cells of the brain. This work compared brain TSPO levels in 20 tobacco smokers (abstinent for at least 2 h) and 20 nonsmokers using a fully quantitative modeling approach for the first time, to our knowledge. Methods: 11C-PBR28 (N-((2-(methoxy-11C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) PET scans were acquired with arterial blood sampling to estimate the metabolite-corrected input function. 11C-PBR28 volumes of distribution were estimated throughout the brain with multilinear analysis. Results: Statistical analyses revealed no evidence of significant differences in regional 11C-PBR28 volumes of distribution between smokers and nonsmokers (whole-brain Cohen d = 0.09) despite adequate power to detect medium effect sizes. Conclusion: These findings inform previous PET studies reporting lower TSPO radiotracer concentrations in the brain (measured as SUV) for tobacco smokers than for nonsmokers by demonstrating the importance of accounting for radiotracer concentrations in plasma. These findings suggest that nonsmokers and smokers have comparable TSPO levels in the brain. Additional work with other biomarkers is needed to fully characterize the effects of tobacco smoking on the brain immune system.
Collapse
Affiliation(s)
- Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut .,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut
| | - Stephanie S O'Malley
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Kelly P Cosgrove
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut
| |
Collapse
|
35
|
Coughlin JM, Horti AG, Pomper MG. Opportunities in precision psychiatry using PET neuroimaging in psychosis. Neurobiol Dis 2019; 131:104428. [PMID: 30904669 PMCID: PMC6744961 DOI: 10.1016/j.nbd.2019.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 12/21/2022] Open
Abstract
With the movement toward precision medicine in healthcare, recent studies of individuals with psychosis have begun to explore positron emission tomography (PET) as a tool to test for biochemical signatures that may distinguish subtypes of psychosis that guide subtype-specific therapeutic interventions. This review presents selected PET findings that exemplify early promise in using molecular imaging to predict treatment response, provide rationale for new therapeutic targets, and monitor target engagement in biomarker-defined subtypes of psychosis. PET data, among other data types, may prove useful in the scientific pursuit of identifying precision strategies to improve clinical outcomes for individuals with psychosis.
Collapse
Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
36
|
Hunter P. Illuminating human disease: The potential of in vivo imaging for preclinical research and diagnostics. EMBO Rep 2019; 20:e49195. [PMID: 31523923 PMCID: PMC6776895 DOI: 10.15252/embr.201949195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
New in vivo imaging technologies, including optical methods to observe biological processes in real time, show great promise for preclinical research and diagnostics of human diseases.
Collapse
|
37
|
Chronic inflammation in multiple sclerosis - seeing what was always there. Nat Rev Neurol 2019; 15:582-593. [PMID: 31420598 DOI: 10.1038/s41582-019-0240-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2019] [Indexed: 12/18/2022]
Abstract
Activation of innate immune cells and other compartmentalized inflammatory cells in the brains and spinal cords of people with relapsing-remitting multiple sclerosis (MS) and progressive MS has been well described histopathologically. However, conventional clinical MRI is largely insensitive to this inflammatory activity. The past two decades have seen the introduction of quantitative dynamic MRI scanning with contrast agents that are sensitive to the reduction in blood-brain barrier integrity associated with inflammation and to the trafficking of inflammatory myeloid cells. New MRI imaging sequences provide improved contrast for better detection of grey matter lesions. Quantitative lesion volume measures and magnetic resonance susceptibility imaging are sensitive to the activity of macrophages in the rims of white matter lesions. PET and magnetic resonance spectroscopy methods can also be used to detect contributions from innate immune activation in the brain and spinal cord. Some of these advanced research imaging methods for visualization of chronic inflammation are practical for relatively routine clinical applications. Observations made with the use of these techniques suggest ways of stratifying patients with MS to improve their care. The imaging methods also provide new tools to support the development of therapies for chronic inflammation in MS.
Collapse
|
38
|
Multiple actions of fenamates and other nonsteroidal anti-inflammatory drugs on GABAA receptors. Eur J Pharmacol 2019; 853:247-255. [DOI: 10.1016/j.ejphar.2019.03.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 01/02/2023]
|
39
|
Development of brain PET imaging agents: Strategies for imaging neuroinflammation in Alzheimer's disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:371-399. [DOI: 10.1016/bs.pmbts.2019.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|