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Kang KJ, Kim YG, Oh SJ, Won J, Lim KS, Baek SH, Lee Y, Choi JY. Determination of optimal injection dose in a small animal-dedicated positron emission tomography for non-human primate neurological studies. Appl Radiat Isot 2024; 211:111404. [PMID: 38917619 DOI: 10.1016/j.apradiso.2024.111404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/10/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024]
Abstract
This study aimed to determine the optimal injection dose for non-human primate positron emission tomography (PET). We first used a monkey brain phantom with a volume of 80,000 mm3 containing 250 MBq of [18F]FDG. Next, we compared the radioactivity difference between the PET images and the actual radioactivity from the dose calibrator to determine the low-error range. We then evaluated the image quality using the NEMA-NU phantom. Finally, [18F]FP-CIT PET images were obtained from two monkeys with middle and high doses. As a result, PET images with a middle injected dose generated reasonable image quality and showed a high signal-to-noise ratio in monkey brain PET with [18F]FP-CIT. These results are expected to be actively applied in PET research using non-human primates.
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Affiliation(s)
- Kyung Jun Kang
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, Republic of Korea
| | - Yu Gyeong Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Republic of Korea
| | - Se Jong Oh
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, Republic of Korea
| | - Jinyoung Won
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Republic of Korea
| | - Kyung Seob Lim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Republic of Korea
| | - Seung Ho Baek
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Republic of Korea
| | - Youngjeon Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Republic of Korea.
| | - Jae Yong Choi
- Division of Applied RI, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, Republic of Korea; Radiological and Medico-Oncological Sciences, University of Science and Technology (UST), Seoul, Republic of Korea.
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2
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Scheyer A, Yasmin F, Naskar S, Patel S. Endocannabinoids at the synapse and beyond: implications for neuropsychiatric disease pathophysiology and treatment. Neuropsychopharmacology 2023; 48:37-53. [PMID: 36100658 PMCID: PMC9700791 DOI: 10.1038/s41386-022-01438-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/10/2022] [Accepted: 08/18/2022] [Indexed: 11/09/2022]
Abstract
Endocannabinoids (eCBs) are lipid neuromodulators that suppress neurotransmitter release, reduce postsynaptic excitability, activate astrocyte signaling, and control cellular respiration. Here, we describe canonical and emerging eCB signaling modes and aim to link adaptations in these signaling systems to pathological states. Adaptations in eCB signaling systems have been identified in a variety of biobehavioral and physiological process relevant to neuropsychiatric disease states including stress-related disorders, epilepsy, developmental disorders, obesity, and substance use disorders. These insights have enhanced our understanding of the pathophysiology of neurological and psychiatric disorders and are contributing to the ongoing development of eCB-targeting therapeutics. We suggest future studies aimed at illuminating how adaptations in canonical as well as emerging cellular and synaptic modes of eCB signaling contribute to disease pathophysiology or resilience could further advance these novel treatment approaches.
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Affiliation(s)
| | - Farhana Yasmin
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Saptarnab Naskar
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Sachin Patel
- Northwestern Center for Psychiatric Neuroscience, Chicago, IL, USA.
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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3
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Neuroplastic alterations in cannabinoid receptors type 1 (CB1) in animal models of epileptic seizures. Neurosci Biobehav Rev 2022; 137:104675. [PMID: 35460705 DOI: 10.1016/j.neubiorev.2022.104675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/16/2022] [Accepted: 04/17/2022] [Indexed: 01/01/2023]
Abstract
Currently, there is an urgent need to better comprehend neuroplastic alterations in cannabinoid receptors type 1 (CB1) and to understand the biological meaning of these alterations in epileptic disorders. The present study reviewed neuroplastic changes in CB1 distribution, expression, and functionality in animal models of epileptic seizures. Neuroplastic alterations in CB1 were consistently observed in chemical, genetic, electrical, and febrile seizure models. Most studies assessed changes in hippocampal and cortical CB1, while thalamic, hypothalamic, and brainstem nuclei were rarely investigated. Additionally, the relationship between CB1 alteration and the control of brain excitability through modulation of specific neuronal networks, such as striatonigral, nigrotectal and thalamocortical pathways, and inhibitory projections to hippocampal pyramidal neurons, were all presented and discussed in the present review. Neuroplastic alterations in CB1 detected in animal models of epilepsy may reflect two different scenarios: (1) endogenous adaptations aimed to control neuronal hyperexcitability in epilepsy or (2) pathological alterations that facilitate neuronal hyperexcitability. Additionally, a better comprehension of neuroplastic and functional alterations in CB1 can improve pharmacological therapies for epilepsies and their comorbidities.
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Sugaya Y, Kano M. Endocannabinoid-Mediated Control of Neural Circuit Excitability and Epileptic Seizures. Front Neural Circuits 2022; 15:781113. [PMID: 35046779 PMCID: PMC8762319 DOI: 10.3389/fncir.2021.781113] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/29/2021] [Indexed: 01/11/2023] Open
Abstract
Research on endocannabinoid signaling has greatly advanced our understanding of how the excitability of neural circuits is controlled in health and disease. In general, endocannabinoid signaling at excitatory synapses suppresses excitability by inhibiting glutamate release, while that at inhibitory synapses promotes excitability by inhibiting GABA release, although there are some exceptions in genetically epileptic animal models. In the epileptic brain, the physiological distributions of endocannabinoid signaling molecules are disrupted during epileptogenesis, contributing to the occurrence of spontaneous seizures. However, it is still unknown how endocannabinoid signaling changes during seizures and how the redistribution of endocannabinoid signaling molecules proceeds during epileptogenesis. Recent development of cannabinoid sensors has enabled us to investigate endocannabinoid signaling in much greater spatial and temporal details than before. Application of cannabinoid sensors to epilepsy research has elucidated activity-dependent changes in endocannabinoid signaling during seizures. Furthermore, recent endocannabinoid research has paved the way for the clinical use of cannabidiol for the treatment of refractory epilepsy, such as Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. Cannabidiol significantly reduces seizures and is considered to have comparable tolerability to conventional antiepileptic drugs. In this article, we introduce recent advances in research on the roles of endocannabinoid signaling in epileptic seizures and discuss future directions.
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Affiliation(s)
- Yuki Sugaya
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, Japan
- *Correspondence: Masanobu Kano,
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5
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Epps SA. Commonalities for comorbidity: Overlapping features of the endocannabinoid system in depression and epilepsy. Front Psychiatry 2022; 13:1041460. [PMID: 36339877 PMCID: PMC9626804 DOI: 10.3389/fpsyt.2022.1041460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 09/29/2022] [Indexed: 11/13/2022] Open
Abstract
A wealth of clinical and pre-clinical data supports a bidirectional comorbidity between depression and epilepsy. This suggests commonalities in underlying mechanisms that may serve as targets for more effective treatment strategies. Unfortunately, many patients with this comorbidity are highly refractory to current treatment strategies, while others experience a worsening of one arm of the comorbidity when treating the other arm. This highlights the need for novel pharmaceutical targets that may provide safe and effective relief for both depression and epilepsy symptoms. The endocannabinoid system (ECS) of the brain has become an area of intense interest for possible roles in depression and epilepsy. Several existing literature reviews have provided in-depth analysis of the involvement of various aspects of the ECS in depression or epilepsy separately, while others have addressed the effectiveness of different treatment strategies targeting the ECS in either condition individually. However, there is not currently a review that considers the ECS when both conditions are comorbid. This mini-review will address areas of common overlap between the ECS in depression and in epilepsy, such as commonalities in endocannabinoids themselves, their receptors, and degradative enzymes. These areas of overlap will be discussed alongside their implications for treatment of this challenging comorbidity.
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Affiliation(s)
- S Alisha Epps
- Department of Psychology, Whitworth University, Spokane, WA, United States
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Identification of clinically relevant biomarkers of epileptogenesis - a strategic roadmap. Nat Rev Neurol 2021; 17:231-242. [PMID: 33594276 DOI: 10.1038/s41582-021-00461-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2021] [Indexed: 01/31/2023]
Abstract
Onset of many forms of epilepsy occurs after an initial epileptogenic insult or as a result of an identified genetic defect. Given that the precipitating insult is known, these epilepsies are, in principle, amenable to secondary prevention. However, development of preventive treatments is difficult because only a subset of individuals will develop epilepsy and we cannot currently predict which individuals are at the highest risk. Biomarkers that enable identification of these individuals would facilitate clinical trials of potential anti-epileptogenic treatments, but no such prognostic biomarkers currently exist. Several putative molecular, imaging, electroencephalographic and behavioural biomarkers of epileptogenesis have been identified, but clinical translation has been hampered by fragmented and poorly coordinated efforts, issues with inter-model reproducibility, study design and statistical approaches, and difficulties with validation in patients. These challenges demand a strategic roadmap to facilitate the identification, characterization and clinical validation of biomarkers for epileptogenesis. In this Review, we summarize the state of the art with respect to biomarker research in epileptogenesis and propose a five-phase roadmap, adapted from those developed for cancer and Alzheimer disease, that provides a conceptual structure for biomarker research.
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Peng W, Liu X, Tan C, Zhou W, Jiang J, Zhou X, Du J, Mo L, Chen L. Zinc-α2-glycoprotein relieved seizure-Induced neuronal glucose uptake impairment via insulin-like growth factor 1 receptor-regulated glucose transporter 3 expression. J Neurochem 2020; 157:695-709. [PMID: 33258143 DOI: 10.1111/jnc.15254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 10/30/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022]
Abstract
Glucose hypometabolism is observed in epilepsy and promotes epileptogenesis. Glucose hypometabolism in epilepsy may be attributed to decreased neuronal glucose uptake, but its molecular mechanism remains unclear. Zinc-α2-glycoprotein (ZAG) is related to glucose metabolism and is reported to suppress seizures. The anti-epileptic effect of ZAG may be attributed to its regulation of neuronal glucose metabolism. This study explored the effect of ZAG on neuronal glucose uptake and its molecular mechanism via insulin-like growth factor 1 receptor (IGF1R)-regulated glucose transporter 3 (GLUT-3) expression. The ZAG level was modulated by lentivirus in primary culture neurons. Neuronal seizure models were induced by Mg2+ -free artificial cerebrospinal fluid. We assessed neuronal glucose uptake by the 2-NBDG method and Glucose Uptake Colorimetric Assay Kit. IGF1R was activated by IGF1 and blocked by AXL1717. The expression and distribution of IGF1R and GLUT-3, together with IGF1R phosphorylation, were measured by western blot. The binding between ZAG and IGF1R was determined by coimmunoprecipitation. Neuronal glucose uptake and GLUT-3 expression were significantly decreased by seizure or ZAG knockdown, whereas ZAG over-expression or IGF1 treatment reversed this decrease. The effect of ZAG on neuronal glucose uptake and GLUT-3 expression was blocked by AXL1717. ZAG increased IGF1R distribution and phosphorylation possibly by binding. Additionally, IGF1R increased GLUT-3 activity by increasing GLUT-3 expression. In epilepsy/seizure, neuronal glucose uptake suppression may be attributed to a decrease in ZAG, which suppresses neuronal GLUT-3 expression by regulating the activity of IGF1R. ZAG, IGF1R, and GLUT-3 may be novel potential therapeutic targets of glucose hypometabolism in epilepsy and seizures.
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Affiliation(s)
- Wuxue Peng
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xi Liu
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Changhong Tan
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wen Zhou
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jin Jiang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xuan Zhou
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Juncong Du
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lijuan Mo
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lifen Chen
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Miederer I, Wiegand V, Bausbacher N, Leukel P, Maus S, Hoffmann MA, Lutz B, Schreckenberger M. Quantification of the Cannabinoid Type 1 Receptor Availability in the Mouse Brain. Front Neuroanat 2020; 14:593793. [PMID: 33328905 PMCID: PMC7714830 DOI: 10.3389/fnana.2020.593793] [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: 08/11/2020] [Accepted: 11/03/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: The endocannabinoid system is involved in several diseases such as addictive disorders, schizophrenia, post-traumatic stress disorder, and eating disorders. As often mice are used as the preferred animal model in translational research, in particular when using genetically modified mice, this study aimed to provide a systematic analysis of in vivo cannabinoid type 1 (CB1) receptor ligand-binding capacity using positron emission tomography (PET) using the ligand [18F]MK-9470. We then compared the PET results with literature data from immunohistochemistry (IHC) to review the consistency between ex vivo protein expression and in vivo ligand binding. Methods: Six male C57BL/6J (6–9 weeks) mice were examined with the CB1 receptor ligand [18F]MK-9470 and small animal PET. Different brain regions were evaluated using the parameter %ID/ml. The PET results of the [18F]MK-9470 accumulation in the mouse brain were compared with immunohistochemical literature data. Results: The ligand [18F]MK-9470 was taken up into the mouse brain within 5 min after injection and exhibited slow kinetics. It accumulated highly in most parts of the brain. PET and IHC classifications were consistent for most parts of the telencephalon, while brain regions of the diencephalon, mesencephalon, and rhombencephalon were rated higher with PET than IHC. Conclusions: This preclinical [18F]MK-9470 study demonstrated the radioligand’s applicability for imaging the region-specific CB1 receptor availability in the healthy adult mouse brain and thus offers the potential to study CB1 receptor availability in pathological conditions.
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Affiliation(s)
- Isabelle Miederer
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Viktoria Wiegand
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nicole Bausbacher
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Petra Leukel
- Institute of Neuropathology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stephan Maus
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Manuela A Hoffmann
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Occupational Health and Safety, Federal Ministry of Defense, Bonn, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Leibniz Institute for Resilience Research, Mainz, Germany
| | - Mathias Schreckenberger
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Xue B, Zhang X, Wang Y. Bench to bedside: Multiple facets of cannabinoid control in epilepsy. Neurochem Int 2020; 141:104898. [PMID: 33159980 DOI: 10.1016/j.neuint.2020.104898] [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: 07/20/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 11/27/2022]
Abstract
Epilepsy is a neurological disease recognized as the consequence of excessive neuronal excitability. Endocannabinoid system, the critical regulator of synaptic inhibition in brain, was supposed to be closely involved in epilepsy. Cannabinoid receptors mostly locate on presynaptic terminals of both excitatory and inhibitory neurons, but with characteristic distribution varying in different brain areas and synapses. Endocannabinoids are synthesized in postsynaptic neurons and retrogradely act on presynaptic cannabinoid receptors. Accumulating evidence suggest that the expression of cannabinoid receptors and synthesis or breakdown of endocannabinoids were cell-type specifically altered and spatiotemporally regulated in seizures, and intervention of the expression of cannabinoid receptors or the level of endocannabinoids could affect seizure actions. Further in clinic, cannabidiol as an add-on treatment could reduce seizures in patients with treatment-resistant epilepsy, but the underlying mechanisms are still unclear and independent of the endocannabinoid system. Therefore, we review recent advances from bench to bedside, to address the cannabinoid control on seizures, discuss the existing confusion in current studies and provide directions for further research, which may be clinically important for the design of cannabinoid-based precise therapeutic interventions for epilepsy.
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Affiliation(s)
- Bao Xue
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China; School of Basic Medicine, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China
| | - Xia Zhang
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China
| | - Ying Wang
- Institute of Brain Science and Disease, Qingdao University, No. 308, Ningxia Road, Qingdao, 266071, China.
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10
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Goutal S, Tournier N, Guillermier M, Van Camp N, Barret O, Gaudin M, Bottlaender M, Hantraye P, Lavisse S. Comparative test-retest variability of outcome parameters derived from brain [18F]FDG PET studies in non-human primates. PLoS One 2020; 15:e0240228. [PMID: 33017429 PMCID: PMC7535063 DOI: 10.1371/journal.pone.0240228] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022] Open
Abstract
INTRODUCTION Knowledge of the repeatability of quantitative parameters derived from [18F]FDG PET images is essential to define the group size and allow correct interpretation. Here we tested repeatability and accuracy of different [18F]FDG absolute and relative quantification parameters in a standardized preclinical setup in nonhuman primates (NHP). MATERIAL AND METHODS Repeated brain [18F]FDG scans were performed in 6 healthy NHP under controlled experimental factors likely to account for variability. Regional cerebral metabolic rate of glucose (CMRglu) was calculated using a Patlak plot with blood input function Semi-quantitative approaches measuring standard uptake values (SUV, SUV×glycemia and SUVR (SUV Ratio) using the pons or cerebellum as a reference region) were considered. Test-retest variability of all quantification parameters were compared in different brain regions in terms of absolute variability and intra-and-inter-subject variabilities. In an independent [18F]FDG PET experiment, robustness of these parameters was evaluated in 4 naive NHP. RESULTS Experimental conditions (injected dose, body weight, animal temperature) were the same at both imaging sessions (p >0.4). No significant difference in the [18F]FDG quantification parameters was found between test and retest sessions. Absolute variability of CMRglu, SUV, SUV×glycemia and normalized SUV ranged from 25 to 43%, 16 to 21%, 23 to 28%, and 7 to 14%, respectively. Intra-subject variability largely explained the absolute variability of all quantitative parameters. They were all significantly correlated to each other and they were all robust. Arterial and venous glycemia were highly correlated (r = 0.9691; p<0.0001). CONCLUSION [18F]FDG test-retest studies in NHP protocols need to be conducted under well-standardized experimental conditions to assess and select the most reliable and reproducible quantification approach. Furthermore, the choice of the quantification parameter has to account for the transversal or follow-up study design. If pons and cerebellum regions are not affected, non-invasive SUVR is the most favorable approach for both designs.
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Affiliation(s)
- Sébastien Goutal
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Nicolas Tournier
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Université Paris-Saclay, Orsay, France
| | - Martine Guillermier
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Nadja Van Camp
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Olivier Barret
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Mylène Gaudin
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Michel Bottlaender
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Université Paris-Saclay, Orsay, France
- UNIACT, Neurospin, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Philippe Hantraye
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Sonia Lavisse
- Laboratoire des Maladies Neurodégénératives, CEA, CNRS, MIRCen, Université Paris-Saclay, Fontenay-aux-Roses, France
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11
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Colom M, Vidal B, Zimmer L. Is There a Role for GPCR Agonist Radiotracers in PET Neuroimaging? Front Mol Neurosci 2019; 12:255. [PMID: 31680859 PMCID: PMC6813225 DOI: 10.3389/fnmol.2019.00255] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/02/2019] [Indexed: 12/30/2022] Open
Abstract
Positron emission tomography (PET) is a molecular imaging modality that enables in vivo exploration of metabolic processes and especially the pharmacology of neuroreceptors. G protein-coupled receptors (GPCRs) play an important role in numerous pathophysiologic disorders of the central nervous system. Thus, they are targets of choice in PET imaging to bring proof concept of change in density in pathological conditions or in pharmacological challenge. At present, most radiotracers are antagonist ligands. In vitro data suggest that properties differ between GPCR agonists and antagonists: antagonists bind to receptors with a single affinity, whereas agonists are characterized by two different affinities: high affinity for receptors that undergo functional coupling to G-proteins, and low affinity for those that are not coupled. In this context, agonist radiotracers may be useful tools to give functional images of GPCRs in the brain, with high sensitivity to neurotransmitter release. Here, we review all existing PET radiotracers used from animals to humans and their role for understanding the ligand-receptor paradigm of GPCR in comparison with corresponding antagonist radiotracers.
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Affiliation(s)
- Matthieu Colom
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France
| | - Benjamin Vidal
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France
| | - Luc Zimmer
- Lyon Neuroscience Research Center, INSERM, CNRS, Université de Lyon, Lyon, France.,CERMEP, Hospices Civils de Lyon, Bron, France.,Institut National des Sciences et Techniques Nucléaires, CEA Saclay, Gif-sur-Yvette, France
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12
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Sekar K, Pack A. Epidiolex as adjunct therapy for treatment of refractory epilepsy: a comprehensive review with a focus on adverse effects. F1000Res 2019; 8. [PMID: 30854190 PMCID: PMC6396837 DOI: 10.12688/f1000research.16515.1] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/20/2019] [Indexed: 11/20/2022] Open
Abstract
Medically refractory epilepsy remains an area of intense clinical and scientific interest since a significant porportion of patients continue to suffer from debilitating seizures despite available therapies. In this setting, recent studies have focused on assessing the benefits of cannabidiol (CBD)-enriched cannabis, a plant based product without psychoactive properties which has been shown to decrease seizure frequency in animal models. More recently, several randomized controlled and open label trials have studied the effects of Epidiolex, a 99% pure oral CBD extract, on patients with refractory epilepsy. This in turn has led to the FDA approval of and more recently, to the Drug Enforcement Administration's placement of Epidiolex into schedule V of the Controlled Substances Act (CSA). In this review, we summarize the major findings of several recent large-scale studies using this product with a focus on its adverse effects.
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Affiliation(s)
- Krithiga Sekar
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Alison Pack
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
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13
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The Highs and Lows of the Endocannabinoid System-Another Piece to the Epilepsy Puzzle? Epilepsy Curr 2018; 18:315-317. [PMID: 30464733 DOI: 10.5698/1535-7597.18.5.315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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14
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Abstract
PURPOSE OF REVIEW For millennia, there has been interest in the use of cannabis for the treatment of epilepsy. However, it is only recently that appropriately powered controlled studies have been completed. In this review, we present an update on the research investigating the use of cannabidiol (CBD), a non-psychoactive component of cannabis, in the treatment of epilepsy. RECENT FINDINGS While the anticonvulsant mechanism of action of CBD has not been entirely elucidated, we discuss the most recent data available including its low affinity for the endocannabinoid receptors and possible indirect modulation of these receptors via blocking the breakdown of anandamide. Additional targets include activation of the transient receptor potential of vanilloid type-1 (TRPV1), antagonist action at GPR55, targeting of abnormal sodium channels, blocking of T-type calcium channels, modulation of adenosine receptors, modulation of voltage-dependent anion selective channel protein (VDAC1), and modulation of tumor necrosis factor alpha release. We also discuss the most recent studies on various artisanal CBD products conducted in patients with epilepsy in the USA and internationally. While a high percentage of patients in these studies reported improvement in seizures, these studies were either retrospective or conducted via survey. Dosage/preparation of CBD was either unknown or not controlled in the majority of these studies. Finally, we present data from both open-label expanded access programs (EAPs) and randomized placebo-controlled trials (RCTs) of a highly purified oral preparation of CBD, which was recently approved by the FDA in the treatment of epilepsy. In the EAPs, there was a significant improvement in seizure frequency seen in a large number of patients with various types of treatment-refractory epilepsy. The RCTs have shown significant seizure reduction compared to placebo in patients with Dravet syndrome and Lennox-Gastaut syndrome. Finally, we describe the available data on adverse effects and drug-drug interactions with highly purified CBD. While this product is overall well tolerated, the most common side effects are diarrhea and sedation, with sedation being much more common in patients taking concomitant clobazam. There was also an increased incidence of aspartate aminotransferase and alanine aminotransferase elevations while taking CBD, with many of the patients with these abnormalities also taking concomitant valproate. CBD has a clear interaction with clobazam, significantly increasing the levels of its active metabolite N-desmethylclobazam in several studies; this is felt to be due to CBD's inhibition of CYP2C19. EAP data demonstrate other possible interactions with rufinamide, zonisamide, topiramate, and eslicarbazepine. Additionally, there is one case report demonstrating need for warfarin dose adjustment with concomitant CBD. Understanding of CBD's efficacy and safety in the treatment of TRE has expanded significantly in the last few years. Future controlled studies of various ratios of CBD and THC are needed as there could be further therapeutic potential of these compounds for patients with epilepsy.
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Affiliation(s)
- Tyler E Gaston
- Department of Neurology, University of Alabama at Birmingham Epilepsy Center, Birmingham, AL, USA
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham Epilepsy Center, Birmingham, AL, USA. .,312 Civitan International Research Center, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35294, USA.
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