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Fauzan M, Oubraim S, Yu M, Glaser ST, Kaczocha M, Haj-Dahmane S. Fatty Acid-Binding Protein 5 Modulates Brain Endocannabinoid Tone and Retrograde Signaling in the Striatum. Front Cell Neurosci 2022; 16:936939. [PMID: 35875351 PMCID: PMC9302024 DOI: 10.3389/fncel.2022.936939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/15/2022] [Indexed: 12/14/2022] Open
Abstract
The endocannabinoid (eCB) anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are endogenous lipid neurotransmitters that regulate an array of physiological functions, including pain, stress homeostasis, and reward. Fatty acid-binding protein 5 (FABP5) is a key modulator of intracellular eCB transport and inactivation. Recent evidence suggests that FABP5 controls synaptic 2-AG signaling at excitatory synapses in the dorsal raphe nucleus. However, it is currently not known whether this function extends to other brain areas. To address this, we first profiled eCB levels across several brain areas in FABP5 knockout mice and wild-type controls and report that FABP5 deletion elevates AEA levels in the striatum, prefrontal cortex, midbrain, and thalamus, as well as midbrain 2-AG levels. The expression of eCB biosynthetic and catabolic enzymes was largely unaltered in these regions, although minor sex and region-specific changes in the expression of 2-AG catabolic enzymes were observed in female FABP5 KO mice. Robust FABP5 expression was observed in the striatum, a region where both AEA and 2-AG control synaptic transmission. Deletion of FABP5 impaired tonic 2-AG and AEA signaling at striatal GABA synapses of medium spiny neurons, and blunted phasic 2-AG mediated short-term synaptic plasticity without altering CB1R expression or function. Collectively, these results support the role of FABP5 as a key regulator of eCB signaling at excitatory and inhibitory synapses in the brain.
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Affiliation(s)
- Mohammad Fauzan
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States,Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States
| | - Saida Oubraim
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Mei Yu
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Sherrye T. Glaser
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States,Department of Biological Sciences, Kingsborough Community College, Brooklyn, NY, United States
| | - Martin Kaczocha
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States,Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, United States,Martin Kaczocha
| | - Samir Haj-Dahmane
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States,University at Buffalo Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States,*Correspondence: Samir Haj-Dahmane
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The Endocannabinoid System in Glial Cells and Their Profitable Interactions to Treat Epilepsy: Evidence from Animal Models. Int J Mol Sci 2021; 22:ijms222413231. [PMID: 34948035 PMCID: PMC8709154 DOI: 10.3390/ijms222413231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is one of the most common neurological conditions. Yearly, five million people are diagnosed with epileptic-related disorders. The neuroprotective and therapeutic effect of (endo)cannabinoid compounds has been extensively investigated in several models of epilepsy. Therefore, the study of specific cell-type-dependent mechanisms underlying cannabinoid effects is crucial to understanding epileptic disorders. It is estimated that about 100 billion neurons and a roughly equal number of glial cells co-exist in the human brain. The glial population is in charge of neuronal viability, and therefore, their participation in brain pathophysiology is crucial. Furthermore, glial malfunctioning occurs in a wide range of neurological disorders. However, little is known about the impact of the endocannabinoid system (ECS) regulation over glial cells, even less in pathological conditions such as epilepsy. In this review, we aim to compile the existing knowledge on the role of the ECS in different cell types, with a particular emphasis on glial cells and their impact on epilepsy. Thus, we propose that glial cells could be a novel target for cannabinoid agents for treating the etiology of epilepsy and managing seizure-like disorders.
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Abstract
Objective: In recent years, the use of cannabidiol in the treatment of refractory epilepsy has been increasingly investigated and has been gaining public support as a novel way to treat these disorders. Marijuana has been used for medical purposes for thousands of years, and a lot of research has been conducted over the last several decades into the chemistry and pharmacology of marijuana and its many compounds, including cannabidiol. Methods: Using PubMed, we performed a review of the literature regarding the history of cannabinoid use in treating epilepsy. Results and conclusions: There are historical and recent scientific developments that support the use of cannabidiol in rare severe epilepsy syndromes.
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Affiliation(s)
- Alexander Doyle
- Department of Neurology, UTSW Epilepsy Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jay Harvey
- Department of Neurology, UTSW Epilepsy Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Abstract
The prevalence and perceived safety of marijuana use in pregnancy are increasing with expanding legalization. Marijuana crosses the placenta and passes into breast milk, resulting in fetal and neonatal exposure. Many women cite medical reasons for prenatal marijuana use such as nausea and vomiting of pregnancy, anxiety, and chronic pain. The scientific literature regarding marijuana in pregnancy is mixed, resulting in confusion among practitioners as to how to counsel women about risks of use. In addition, there is a paucity of literature related to marijuana use and breastfeeding. Existing pregnancy studies are predominantly retrospective cohorts with a reliance on self-report for ascertainment of exposure, which underestimates use. Many studies fail to adjust for important confounding factors such as tobacco use and sociodemographic differences. Despite the limitations of the existing evidence, there are animal and human data suggesting potential harm of cannabis use. The harms are biologically plausible given the role of the endocannabinoid system in pregnancy implantation, placentation, and fetal neurologic development. Two recent systematic reviews and meta-analyses found an association between marijuana use and adverse perinatal outcomes, especially with heavy marijuana use. In addition, three longitudinal cohort studies demonstrate a possible effect of prenatal marijuana exposure on long-term neurobehavioral outcomes. Marijuana use may be associated with growth restriction, stillbirth, spontaneous preterm birth, and neonatal intensive care unit admission. Therefore, women should be advised to refrain from using marijuana during pregnancy and lactation.
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Yao I, Stein ES, Maggio N. Cannabinoids, hippocampal excitability and efficacy for the treatment of epilepsy. Pharmacol Ther 2019; 202:32-39. [PMID: 31176695 DOI: 10.1016/j.pharmthera.2019.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/23/2019] [Indexed: 01/31/2023]
Abstract
Interest in cannabis and its related cannabinoids THC and CBD for use as anti-convulsant therapy has been progressively increasing. While the destigmatization of cannabis and cannabis related research have progressed in the last few decades, there are still many questions that remain unanswered. This review seeks to summarize the progress made in cannabis research in the past four decades and to identify possible directions for future research that are critical for the development of cannabinoid-based therapy in epilepsy.
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Affiliation(s)
- Isaac Yao
- Department of Neurology, The Chaim Sheba Medical Center at Tel Hashomer, 52621 Ramat Gan, Israel; Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Efrat Shavit Stein
- Department of Neurology, The Chaim Sheba Medical Center at Tel Hashomer, 52621 Ramat Gan, Israel
| | - Nicola Maggio
- Department of Neurology, The Chaim Sheba Medical Center at Tel Hashomer, 52621 Ramat Gan, Israel; Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, 6997801 Tel Aviv, Israel; Talpiot Medical Leadership Program, The Chaim Sheba Medical Center at Tel HaShomer, 52621 Ramat Gan, Israel.
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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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De Caro C, Leo A, Citraro R, De Sarro C, Russo R, Calignano A, Russo E. The potential role of cannabinoids in epilepsy treatment. Expert Rev Neurother 2017; 17:1069-1079. [PMID: 28845714 DOI: 10.1080/14737175.2017.1373019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Epilepsy is one of the world's oldest recognized and prevalent neurological diseases. It has a great negative impact on patients' quality of life (QOL) as a consequence of treatment resistant seizures in about 30% of patients together with drugs' side effects and comorbidities. Therefore, new drugs are needed and cannabinoids, above all cannabidiol, have recently gathered attention. Areas covered: This review summarizes the scientific data from human and animal studies on the major cannabinoids which have been of interest in the treatment of epilepsy, including drugs acting on the endocannabinoid system. Expert commentary: Despite the fact that cannabis has been used for many purposes over 4 millennia, the development of drugs based on cannabinoids has been very slow. Only recently, research has focused on their potential effects and CBD is the first treatment of this group with clinical evidence of efficacy in children with Dravet syndrome; moreover, other studies are currently ongoing to confirm its effectiveness in patients with epilepsy. On the other hand, it will be of interest to understand whether drugs acting on the endocannabinoid system will be able to reach the market and prove their known preclinical efficacy also in patients with epilepsy.
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Affiliation(s)
- Carmen De Caro
- a Department of Science of Health, School of Medicine and Surgery , University "Magna Graecia" of Catanzaro , Catanzaro , Italy
| | - Antonio Leo
- a Department of Science of Health, School of Medicine and Surgery , University "Magna Graecia" of Catanzaro , Catanzaro , Italy
| | - Rita Citraro
- a Department of Science of Health, School of Medicine and Surgery , University "Magna Graecia" of Catanzaro , Catanzaro , Italy
| | - Caterina De Sarro
- a Department of Science of Health, School of Medicine and Surgery , University "Magna Graecia" of Catanzaro , Catanzaro , Italy
| | - Roberto Russo
- b Department of Pharmacy , University of Naples Federico II , Naples , Italy
| | - Antonio Calignano
- b Department of Pharmacy , University of Naples Federico II , Naples , Italy
| | - Emilio Russo
- a Department of Science of Health, School of Medicine and Surgery , University "Magna Graecia" of Catanzaro , Catanzaro , Italy
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Pharmacology of cannabinoids in the treatment of epilepsy. Epilepsy Behav 2017; 70:313-318. [PMID: 28087250 DOI: 10.1016/j.yebeh.2016.11.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/09/2016] [Accepted: 11/11/2016] [Indexed: 01/01/2023]
Abstract
The use of cannabis products in the treatment of epilepsy has long been of interest to researchers and clinicians alike; however, until recently very little published data were available to support its use. This article summarizes the available scientific data of pharmacology from human and animal studies on the major cannabinoids which have been of interest in the treatment of epilepsy, including ∆9-tetrahydrocannabinol (∆9-THC), cannabidiol (CBD), ∆9-tetrahydrocannabivarin (∆9-THCV), cannabidivarin (CBDV), and ∆9-tetrahydrocannabinolic acid (Δ9-THCA). It has long been known that ∆9-THC has partial agonist activity at the endocannabinoid receptors CB1 and CB2, though it also binds to other targets which may modulate neuronal excitability and neuroinflammation. The actions of Δ9-THCV and Δ9-THCA are less well understood. In contrast to ∆9-THC, CBD has low affinity for CB1 and CB2 receptors and other targets have been investigated to explain its anticonvulsant properties including TRPV1, voltage gated potassium and sodium channels, and GPR55, among others. We describe the absorption, distribution, metabolism, and excretion of each of the above mentioned compounds. Cannabinoids as a whole are very lipophilic, resulting in decreased bioavailability, which presents challenges in optimal drug delivery. Finally, we discuss the limited drug-drug interaction data available on THC and CBD. As cannabinoids and cannabis-based products are studied for efficacy as anticonvulsants, more investigation is needed regarding the specific targets of action, optimal drug delivery, and potential drug-drug interactions. This article is part of a Special Issue titled Cannabinoids and Epilepsy.
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Rosenberg EC, Patra PH, Whalley BJ. Therapeutic effects of cannabinoids in animal models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. Epilepsy Behav 2017; 70:319-327. [PMID: 28190698 PMCID: PMC5651410 DOI: 10.1016/j.yebeh.2016.11.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022]
Abstract
The isolation and identification of the discrete plant cannabinoids in marijuana revived interest in analyzing historical therapeutic claims made for cannabis in clinical case studies and anecdotes. In particular, sources as old as the 11th and 15th centuries claimed efficacy for crude marijuana extracts in the treatment of convulsive disorders, prompting a particularly active area of preclinical research into the therapeutic potential of plant cannabinoids in epilepsy. Since that time, a large body of literature has accumulated describing the effects of several of the >100 individual plant cannabinoids in preclinical models of seizures, epilepsy, epileptogenesis, and epilepsy-related neuroprotection. We surveyed the literature for relevant reports of such plant cannabinoid effects and critically reviewed their findings. We found that acute CB1R agonism in simple models of acute seizures in rodents typically produces anti-convulsant effects whereas CB1R antagonists exert converse effects in the same models. However, when the effects of such ligands are examined in more complex models of epilepsy, epileptogenesis and neuroprotection, a less simplistic narrative emerges. Here, the complex interactions between (i) brain regions involved in a given model, (ii) relative contributions of endocannabinoid signaling to modulation of synaptic transmission in such areas, (iii) multi-target effects, (iv) cannabinoid type 1 and type 2 receptor signaling interactions and, (v) timing, (vi) duration and (vii) localization of ligand administration suggest that there is both anti-epileptic therapeutic potential and a pro-epileptic risk in up- and down-regulation of endocannabinoid signaling in the central nervous system. Factors such receptor desensitization and specific pharmacology of ligands used (e.g. full vs partial agonists and neutral antagonists vs inverse agonists) also appear to play an important role in the effects reported. Furthermore, the effects of several plant cannabinoids, most notably cannabidiol (CBD) and cannabidavarin (CBDV), in models of seizures, epilepsy, epileptogenesis, and neuroprotection are less ambiguous, and consistent with reports of therapeutically beneficial effects of these compounds in clinical studies. However, continued paucity of firm information regarding the therapeutic molecular mechanism of CBD/CBDV highlights the continued need for research in this area in order to identify as yet under-exploited targets for drug development and raise our understanding of treatment-resistant epilepsies. The recent reporting of positive results for cannabidiol treatment in two Phase III clinical trials in treatment-resistant epilepsies provides pivotal evidence of clinical efficacy for one plant cannabinoid in epilepsy. Moreover, risks and/or benefits associated with the use of unlicensed Δ9-THC containing marijuana extracts in pediatric epilepsies remain poorly understood. Therefore, in light of these paradigm-changing clinical events, the present review's findings aim to drive future drug development for newly-identified targets and indications, identify important limitations of animal models in the investigation of plant cannabinoid effects in the epilepsies, and focuses future research in this area on specific, unanswered questions regarding the complexities of endocannabinoid signaling in epilepsy. This article is part of a Special Issue titled Cannabinoids and Epilepsy.
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Affiliation(s)
- Evan C. Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Pabitra H. Patra
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK
| | - Benjamin J. Whalley
- Department of Pharmacy, School of Chemistry, Food & Nutritional Sciences and Pharmacy, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, UK,Corresponding author: (B.J. Whalley)
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de Carvalho CR, Hoeller AA, Franco PLC, Martini APS, Soares FMS, Lin K, Prediger RD, Whalley BJ, Walz R. The cannabinoid CB2 receptor-specific agonist AM1241 increases pentylenetetrazole-induced seizure severity in Wistar rats. Epilepsy Res 2016; 127:160-167. [PMID: 27608434 DOI: 10.1016/j.eplepsyres.2016.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/02/2016] [Accepted: 08/12/2016] [Indexed: 11/25/2022]
Abstract
The potential efficacy of cannabinoid receptor ligands for the treatment of epilepsy remains controversial; cannabis components that act via cannabinoid type 1 (CB1) receptors produce anticonvulsant effects in animal models despite treatment with the CB receptor agonist reliably inducing convulsions in various species. Moreover, the potential role of cannabinoid receptor type 2 (CB2) to modulate seizures remains under-investigated. This study assessed the effects of the selective CB2 receptor agonist, AM1241, on pentylenetetrazole (PTZ)-induced seizures in rats. A stereotactically placed guide cannula was surgically implanted into the right lateral ventricle in adult Wistar rats which, 5-6days later, received an acute intracerebroventricular (i.c.v.) microinfusion of AM1241 (0.01, 1 or 10μg/2μl or vehicle) 5min before intraperitoneal (i.p.) injection of PTZ (70mg/kg). Rats were observed for 30min and the seizure severity behavior measured using a modified Racine's scale. Additional groups of rats were pretreated with a single low dose of the selective CB2 receptor antagonist, AM630 (dose 1mg/kg; i.p.), or vehicle, 30min prior to i.c.v. microinfusion of AM1241 (1μg/2μl). AM1241 administration significantly increased tonic-clonic seizure incidence and severity while also decreasing the onset of generalized seizures (AM1241 1 and 10μg/2μl). Pretreatment with AM630 prevented the proconvulsant effects of AM1241. This study shows, for the first time, that selective activation of CB2 receptors can increase generalized seizure susceptibility and suggests that pathological hyperexcitability phenomena can be differentially regulated by targeting CB1 and CB2 receptors.
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Affiliation(s)
- Cristiane R de Carvalho
- Programa de Pós- graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
| | - Alexandre A Hoeller
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Programa de Pós- graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Pedro L C Franco
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Athos P S Martini
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Flávia M S Soares
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Programa de Pós- graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Katia Lin
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Programa de Pós- graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Serviço de Neurologia, Departamento de Clínica Médica, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rui D Prediger
- Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Benjamin J Whalley
- School of Chemistry, Food and Nutritional Sciences, and Pharmacy, The University of Reading, Reading, Berkshire RG6 6AP, UK
| | - Roger Walz
- Programa de Pós- graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Centro de Neurociências Aplicadas, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Programa de Pós- graduação em Ciências Médicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Serviço de Neurologia, Departamento de Clínica Médica, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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Abiega O, Beccari S, Diaz-Aparicio I, Nadjar A, Layé S, Leyrolle Q, Gómez-Nicola D, Domercq M, Pérez-Samartín A, Sánchez-Zafra V, Paris I, Valero J, Savage JC, Hui CW, Tremblay MÈ, Deudero JJP, Brewster AL, Anderson AE, Zaldumbide L, Galbarriatu L, Marinas A, Vivanco MDM, Matute C, Maletic-Savatic M, Encinas JM, Sierra A. Neuronal Hyperactivity Disturbs ATP Microgradients, Impairs Microglial Motility, and Reduces Phagocytic Receptor Expression Triggering Apoptosis/Microglial Phagocytosis Uncoupling. PLoS Biol 2016; 14:e1002466. [PMID: 27228556 PMCID: PMC4881984 DOI: 10.1371/journal.pbio.1002466] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/21/2016] [Indexed: 12/24/2022] Open
Abstract
Phagocytosis is essential to maintain tissue homeostasis in a large number of inflammatory and autoimmune diseases, but its role in the diseased brain is poorly explored. Recent findings suggest that in the adult hippocampal neurogenic niche, where the excess of newborn cells undergo apoptosis in physiological conditions, phagocytosis is efficiently executed by surveillant, ramified microglia. To test whether microglia are efficient phagocytes in the diseased brain as well, we confronted them with a series of apoptotic challenges and discovered a generalized response. When challenged with excitotoxicity in vitro (via the glutamate agonist NMDA) or inflammation in vivo (via systemic administration of bacterial lipopolysaccharides or by omega 3 fatty acid deficient diets), microglia resorted to different strategies to boost their phagocytic efficiency and compensate for the increased number of apoptotic cells, thus maintaining phagocytosis and apoptosis tightly coupled. Unexpectedly, this coupling was chronically lost in a mouse model of mesial temporal lobe epilepsy (MTLE) as well as in hippocampal tissue resected from individuals with MTLE, a major neurological disorder characterized by seizures, excitotoxicity, and inflammation. Importantly, the loss of phagocytosis/apoptosis coupling correlated with the expression of microglial proinflammatory, epileptogenic cytokines, suggesting its contribution to the pathophysiology of epilepsy. The phagocytic blockade resulted from reduced microglial surveillance and apoptotic cell recognition receptor expression and was not directly mediated by signaling through microglial glutamate receptors. Instead, it was related to the disruption of local ATP microgradients caused by the hyperactivity of the hippocampal network, at least in the acute phase of epilepsy. Finally, the uncoupling led to an accumulation of apoptotic newborn cells in the neurogenic niche that was due not to decreased survival but to delayed cell clearance after seizures. These results demonstrate that the efficiency of microglial phagocytosis critically affects the dynamics of apoptosis and urge to routinely assess the microglial phagocytic efficiency in neurodegenerative disorders. Phagocytosis by microglia is tightly coupled to apoptosis, swiftly removing apoptotic cells and actively maintaining tissue homeostasis, but the neuronal hyperactivity associated with epilepsy disrupts the ATP gradients that drive phagocytosis, leading to the accumulation of apoptotic cells and inflammation. Phagocytosis, the engulfment and digestion of cellular debris, is at the core of the regenerative response of the damaged tissue, because it prevents the spillover of toxic intracellular contents and is actively anti-inflammatory. In the brain, the professional phagocytes are microglia, whose dynamic processes rapidly engulf and degrade cells undergoing apoptosis—programmed cell death—in physiological conditions. Thus, microglia hold the key to brain regeneration, but their efficiency as phagocytes in the diseased brain is only presumed. Here, we have discovered a generalized response of microglia to apoptotic challenge induced by excitotoxicity and inflammation, in which they boost their phagocytic efficiency to account for the increase in apoptosis. To our surprise, this apoptosis/microglial phagocytosis coupling was lost in the hippocampus from human and experimental mesial temporal lobe epilepsy (MTLE), a major neurodegenerative disorder characterized by excitotoxicity, inflammation, and seizures. This uncoupling was due to widespread ATP release during neuronal hyperactivity, which “blinded” microglia to the ATP microgradients released by apoptotic cells as “find-me” signals. The impairment of phagocytosis led to the accumulation of apoptotic cells and the build-up of a detrimental inflammatory reaction. Our data advocates for systematic assessment of the efficiency of microglial phagocytosis in brain disorders.
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Affiliation(s)
- Oihane Abiega
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Sol Beccari
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Irune Diaz-Aparicio
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | | | - Sophie Layé
- Université Bordeaux Segalen, Bordeaux, France
| | | | - Diego Gómez-Nicola
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - María Domercq
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Alberto Pérez-Samartín
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Víctor Sánchez-Zafra
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Iñaki Paris
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
- Ikerbasque Foundation, Bilbao, Spain
| | - Julie C. Savage
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada
- Université Laval, Département de médecine moléculaire, Québec, Canada
| | - Chin-Wai Hui
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada
- Université Laval, Département de médecine moléculaire, Québec, Canada
| | - Marie-Ève Tremblay
- Centre de recherche du CHU de Québec, Axe Neurosciences, Québec, Canada
- Université Laval, Département de médecine moléculaire, Québec, Canada
| | - Juan J. P. Deudero
- Baylor College of Medicine, The Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, United States of America
| | - Amy L. Brewster
- Baylor College of Medicine, The Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, United States of America
| | - Anne E. Anderson
- Baylor College of Medicine, The Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, United States of America
| | | | | | | | | | - Carlos Matute
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
| | | | - Juan M. Encinas
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
- Baylor College of Medicine, The Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, United States of America
| | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- University of the Basque Country, Leioa, Spain
- Baylor College of Medicine, The Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, United States of America
- * E-mail:
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12
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Reddy DS, Golub VM. The Pharmacological Basis of Cannabis Therapy for Epilepsy. J Pharmacol Exp Ther 2016; 357:45-55. [PMID: 26787773 DOI: 10.1124/jpet.115.230151] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/15/2016] [Indexed: 12/30/2022] Open
Abstract
Recently, cannabis has been suggested as a potential alternative therapy for refractory epilepsy, which affects 30% of epilepsy, both adults and children, who do not respond to current medications. There is a large unmet medical need for new antiepileptics that would not interfere with normal function in patients with refractory epilepsy and conditions associated with refractory seizures. The two chief cannabinoids are Δ-9-tetrahyrdrocannabinol, the major psychoactive component of marijuana, and cannabidiol (CBD), the major nonpsychoactive component of marijuana. Claims of clinical efficacy in epilepsy of CBD-predominant cannabis or medical marijuana come mostly from limited studies, surveys, or case reports. However, the mechanisms underlying the antiepileptic efficacy of cannabis remain unclear. This article highlights the pharmacological basis of cannabis therapy, with an emphasis on the endocannabinoid mechanisms underlying the emerging neurotherapeutics of CBD in epilepsy. CBD is anticonvulsant, but it has a low affinity for the cannabinoid receptors CB1 and CB2; therefore the exact mechanism by which it affects seizures remains poorly understood. A rigorous clinical evaluation of pharmaceutical CBD products is needed to establish the safety and efficacy of their use in the treatment of epilepsy. Identification of mechanisms underlying the anticonvulsant efficacy of CBD is also critical for identifying other potential treatment options.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| | - Victoria M Golub
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas
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13
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Abstract
Cannabis has been used for centuries to treat seizures. Recent anecdotal reports, accumulating animal model data, and mechanistic insights have raised interest in cannabis-based antiepileptic therapies. In this study, we review current understanding of the endocannabinoid system, characterize the pro- and anticonvulsive effects of cannabinoids [e.g., Δ9-tetrahydrocannabinol and cannabidiol (CBD)], and highlight scientific evidence from pre-clinical and clinical trials of cannabinoids in epilepsy. These studies suggest that CBD avoids the psychoactive effects of the endocannabinoid system to provide a well-tolerated, promising therapeutic for the treatment of seizures, while whole-plant cannabis can both contribute to and reduce seizures. Finally, we discuss results from a new multicenter, open-label study using CBD in a population with treatment-resistant epilepsy. In all, we seek to evaluate our current understanding of cannabinoids in epilepsy and guide future basic science and clinical studies.
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Affiliation(s)
- Evan C Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Richard W Tsien
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Benjamin J Whalley
- School of Pharmacy, The University of Reading, Whiteknights, Reading, RG6 6AP, UK
| | - Orrin Devinsky
- Department of Neurology, Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, 10016, UK.
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14
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Caltana L, Saez TM, Aronne MP, Brusco A. Cannabinoid receptor type 1 agonist ACEA improves motor recovery and protects neurons in ischemic stroke in mice. J Neurochem 2015; 135:616-29. [PMID: 26296704 DOI: 10.1111/jnc.13288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 08/04/2015] [Accepted: 08/15/2015] [Indexed: 12/21/2022]
Abstract
Brain ischemia produces neuronal cell death and the recruitment of pro-inflammatory cells. In turn, the search for neuroprotection against this type of insult has rendered results involving a beneficial role of endocannabinoid receptor agonists in the Central Nervous System. In this work, to further elucidate the mechanisms associated to this neuroprotective effect, focal brain ischemia was generated by middle cerebral artery occlusion (MCAo) in C57Bl/6 mice. Three, 24 and 48 h after MCAo, animals received CB1R agonist ACEA (1 mg/kg), CB1R antagonist AM251 (1 mg/kg) or vehicle. To assess motor activity, neural deficit scores and motor tests were performed 1 day before and 3, 7, 14, 21, and 28 days after MCAo. At 7 and 28 days post lesion, cytoskeleton structure, astroglial and microglial reaction, and alterations in synapsis were studied in the cerebral cortex. ACEA treatment reduced astrocytic reaction, neuronal death, and dendritic loss. In contrast, AM251 treatment increased these parameters. Motor tests showed a progressive deterioration in motor activity in ischemic animals, which only ACEA treatment was able to counteract. Our results suggest that CB1R may be involved in neuronal survival and in the regulation of neuroprotection during focal cerebral ischemia in mice.
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Affiliation(s)
- Laura Caltana
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (UBA-CONICET). Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Trinidad Maria Saez
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (UBA-CONICET). Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - María Paula Aronne
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (UBA-CONICET). Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alicia Brusco
- Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (UBA-CONICET). Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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15
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Soltesz I, Alger BE, Kano M, Lee SH, Lovinger DM, Ohno-Shosaku T, Watanabe M. Weeding out bad waves: towards selective cannabinoid circuit control in epilepsy. Nat Rev Neurosci 2015; 16:264-77. [PMID: 25891509 PMCID: PMC10631555 DOI: 10.1038/nrn3937] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endocannabinoids are lipid-derived messengers, and both their synthesis and breakdown are under tight spatiotemporal regulation. As retrograde signalling molecules, endocannabinoids are synthesized postsynaptically but activate presynaptic cannabinoid receptor 1 (CB1) receptors to inhibit neurotransmitter release. In turn, CB1-expressing inhibitory and excitatory synapses act as strategically placed control points for activity-dependent regulation of dynamically changing normal and pathological oscillatory network activity. Here, we highlight emerging principles of cannabinoid circuit control and plasticity, and discuss their relevance for epilepsy and related comorbidities. New insights into cannabinoid signalling may facilitate the translation of the recent interest in cannabis-related substances as antiseizure medications to evidence-based treatment strategies.
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Affiliation(s)
- Ivan Soltesz
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - Bradley E Alger
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Sang-Hun Lee
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - David M Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, US National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Takako Ohno-Shosaku
- Department of Impairment Study, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-0942, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
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16
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Abstract
The antiepileptic potential of Cannabis sativa preparations has been historically recognized. Recent changes in legal restrictions and new well-documented cases reporting remarkably strong beneficial effects have triggered an upsurge in exploiting medical marijuana in patients with refractory epilepsy. Parallel research efforts in the last decade have uncovered the fundamental role of the endogenous cannabinoid system in controlling neuronal network excitability raising hopes for cannabinoid-based therapeutic approaches. However, emerging data show that patient responsiveness varies substantially, and that cannabis administration may sometimes even exacerbate seizures. Qualitative and quantitative chemical variability in cannabis products and personal differences in the etiology of seizures, or in the pathological reorganization of epileptic networks, can all contribute to divergent patient responses. Thus, the consensus view in the neurologist community is that drugs modifying the activity of the endocannabinoid system should first be tested in clinical trials to establish efficacy, safety, dosing, and proper indication in specific forms of epilepsies. To support translation from anecdote-based practice to evidence-based therapy, the present review first introduces current preclinical and clinical efforts for cannabinoid- or endocannabinoid-based epilepsy treatments. Next, recent advances in our knowledge of how endocannabinoid signaling limits abnormal network activity as a central component of the synaptic circuit-breaker system will be reviewed to provide a framework for the underlying neurobiological mechanisms of the beneficial and adverse effects. Finally, accumulating evidence demonstrating robust synapse-specific pathophysiological plasticity of endocannabinoid signaling in epileptic networks will be summarized to gain better understanding of how and when pharmacological interventions may have therapeutic relevance.
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Affiliation(s)
- István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u. 43, Budapest, 1083, Hungary.
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