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Mikkelsen JD, Aripaka SS, Egilmez CB, Pazarlar BA. Binding of the monoacylglycerol lipase (MAGL) radiotracer [ 3H]T-401 in the rat brain after status epilepticus. Neurochem Int 2024; 175:105717. [PMID: 38447759 DOI: 10.1016/j.neuint.2024.105717] [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: 12/19/2023] [Revised: 02/29/2024] [Accepted: 03/03/2024] [Indexed: 03/08/2024]
Abstract
OBJECTIVES Monoacylglycerol lipase (MAGL) is a cytosolic serine hydrolase considered a potential novel drug target for the treatment of CNS disorders including epilepsy. Here we examined MAGL levels in a rat model of epilepsy. METHODS Autoradiography has been used to validate the binding properties of the MAGL radiotracer, [3H]T-401, in the rat brain, and to explore spatial and temporal changes in binding levels in a model of temporal lobe epilepsy model using unilateral intra-hippocampal injections of kainic acid (KA) in rats. RESULTS Specific and saturable binding of [3H]T-401 was detected in both cortical grey and subcortical white matter. Saturation experiments revealed a KD in the range between 15 nM and 17 nM, and full saturation was achieved at concentrations around 30 nM. The binding could be completely blocked with the cold ligand (Ki 44.2 nM) and at higher affinity (Ki 1.27 nM) with another structurally different MAGL inhibitor, ABD 1970. Bilateral reduction in [3H]T-401 binding was observed in the cerebral cortex and the hippocampus few days after status epilepticus that further declined to a level of around 30% compared to the control. No change in binding was observed in either the hypothalamus nor the white matter at any time point. Direct comparison to [3H]UCB-J binding to synaptic vesicle glycoprotein 2 A (SV2A), another protein localized in the pre-synapse, revealed that while binding to MAGL remained low in the chronic phase, SV2A was increased significantly in some cortical areas. SIGNIFICANCE These data show that MAGL is reduced in the cerebral cortex and hippocampus in a chronic epilepsy model and indicate that MAGL inhibitors may further reduce MAGL activity in the treatment resistant epilepsy patient.
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Affiliation(s)
- Jens D Mikkelsen
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark; Institute of Neuroscience, University of Copenhagen, Denmark.
| | - Sanjay S Aripaka
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Cansu B Egilmez
- Physiology Department, Faculty of Medicine, Izmir Katip Celebi University, Izmir, Turkey
| | - Burcu A Pazarlar
- Neurobiology Research Unit, University Hospital Rigshospitalet, Copenhagen, Denmark; Institute of Neuroscience, University of Copenhagen, Denmark; Physiology Department, Faculty of Medicine, Izmir Katip Celebi University, Izmir, Turkey
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Yadav-Samudrala BJ, Ravula HP, Barmada KM, Dodson H, Poklis JL, Ignatowska-Jankowska BM, Lichtman AH, Reissner KJ, Fitting S. Acute Effects of Monoacylglycerol Lipase Inhibitor ABX1431 on Neuronal Hyperexcitability, Nociception, Locomotion, and the Endocannabinoid System in HIV-1 Tat Male Mice. Cannabis Cannabinoid Res 2024. [PMID: 38394322 DOI: 10.1089/can.2023.0247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024] Open
Abstract
Background: Evidence suggests that monoacylglycerol lipase (MAGL) inhibitors can potentially treat HIV symptoms by increasing the concentration of 2-arachidonoylglycerol (2-AG). We examined a selective MAGL inhibitor ABX1431 in the context of neuroHIV. Methods: To assess the effects of ABX1431, we conducted in vitro and in vivo studies. In vitro calcium imaging on frontal cortex neuronal cultures was performed to evaluate the role of ABX1431 (10, 30, 100 nM) on transactivator of transcription (Tat)-induced neuronal hyperexcitability. Following in vitro experiments, in vivo experiments were performed using Tat transgenic male mice. Mice were treated with 4 mg/kg ABX1431 and assessed for antinociception using tail-flick and hot plate assays followed by locomotor activity. After the behavioral experiments, their brains were harvested to quantify endocannabinoids (eCB) and related lipids through mass spectrometry, and cannabinoid type-1 and -2 receptors (CB1R and CB2R) were quantified through western blot. Results: In vitro studies revealed that adding Tat directly to the neuronal cultures significantly increased intracellular calcium concentration, which ABX1431 completely reversed at all concentrations. Preincubating the cultures with CB1R and CB2R antagonists showed that ABX1431 exhibited its effects partially through CB1R. In vivo studies demonstrated that acute ABX1431 increased overall total distance traveled and speed of mice regardless of their genotype. Mass spectrometry and western blot analyses revealed differential effects on the eCB system based on Tat expression. The 2-AG levels were significantly upregulated following ABX1431 treatment in the striatum and spinal cord. Arachidonic acid (AA) was also upregulated in the striatum of vehicle-treated Tat(+) mice. No changes were noted in CB1R expression levels; however, CB2R levels were increased in ABX1431-treated Tat(-) mice only. Conclusion: Findings indicate that ABX1431 has potential neuroprotective effects in vitro partially mediated through CB1R. Acute treatment of ABX1431 in vivo shows antinociceptive effects, and seems to alter locomotor activity, with upregulating 2-AG levels in the striatum and spinal cord.
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Affiliation(s)
- Barkha J Yadav-Samudrala
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Havilah P Ravula
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Karenna M Barmada
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Hailey Dodson
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Justin L Poklis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Kathryn J Reissner
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sylvia Fitting
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Janero DR. Current strategic trends in drug discovery: the present as prologue. Expert Opin Drug Discov 2024; 19:147-159. [PMID: 37936504 DOI: 10.1080/17460441.2023.2275640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/23/2023] [Indexed: 11/09/2023]
Abstract
INTRODUCTION Escalating costs and inherent uncertainties associated with drug discovery invite initiatives to improve its efficiency and de-risk campaigns for inventing better therapeutics. One such initiative involves recognizing and exploiting current approaches in therapeutics invention with molecular mechanisms of action that hold promise for designing and targeting new chemical entities as drugs. AREAS COVERED This perspective considers the current contextual framework around three drug-discovery approaches and evaluates their potential to help identify new targets/modalities in small-molecule molecular pharmacology: diversifying ligand-directed phenotypes for G protein-coupled receptor (GPCR) pharmacotherapeutic signaling; developing therapeutic-protein degraders and stabilizers for proximity-inducing pharmacology; and mining organelle biology for druggable therapeutic targets. EXPERT OPINION The contemporary drug-discovery approaches examined appear generalizable and versatile to have applications in therapeutics invention beyond those case studies discussed herein. Accordingly, they may be considered strategic trends worthy of note in advancing the field toward novel ways of addressing pharmacotherapeutically unmet medical needs.
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Affiliation(s)
- David R Janero
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, and Health Sciences Entrepreneurs, Northeastern University, Boston, MA, USA
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Harman T, Udoh M, McElroy DL, Anderson LL, Kevin RC, Banister SD, Ametovski A, Markham J, Bladen C, Doohan PT, Greba Q, Laprairie RB, Snutch TP, McGregor IS, Howland JG, Arnold JC. MEPIRAPIM-derived synthetic cannabinoids inhibit T-type calcium channels with divergent effects on seizures in rodent models of epilepsy. Front Physiol 2023; 14:1086243. [PMID: 37082241 PMCID: PMC10110893 DOI: 10.3389/fphys.2023.1086243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/17/2023] [Indexed: 04/22/2023] Open
Abstract
Background: T-type Ca2+ channels (Cav3) represent emerging therapeutic targets for a range of neurological disorders, including epilepsy and pain. To aid the development and optimisation of new therapeutics, there is a need to identify novel chemical entities which act at these ion channels. A number of synthetic cannabinoid receptor agonists (SCRAs) have been found to exhibit activity at T-type channels, suggesting that cannabinoids may provide convenient chemical scaffolds on which to design novel Cav3 inhibitors. However, activity at cannabinoid type 1 (CB1) receptors can be problematic because of central and peripheral toxicities associated with potent SCRAs. The putative SCRA MEPIRAPIM and its analogues were recently identified as Cav3 inhibitors with only minimal activity at CB1 receptors, opening the possibility that this scaffold may be exploited to develop novel, selective Cav3 inhibitors. Here we present the pharmacological characterisation of SB2193 and SB2193F, two novel Cav3 inhibitors derived from MEPIRAPIM. Methods: The potency of SB2193 and SB2193F was evaluated in vitro using a fluorometric Ca2+ flux assay and confirmed using whole-cell patch-clamp electrophysiology. In silico docking to the cryo-EM structure of Cav3.1 was also performed to elucidate structural insights into T-type channel inhibition. Next, in vivo pharmacokinetic parameters in mouse brain and plasma were determined using liquid chromatography-mass spectroscopy. Finally, anticonvulsant activity was assayed in established genetic and electrically-induced rodent seizure models. Results: Both MEPIRAPIM derivatives produced potent inhibition of Cav3 channels and were brain penetrant, with SB2193 exhibiting a brain/plasma ratio of 2.7. SB2193 was further examined in mouse seizure models where it acutely protected against 6 Hz-induced seizures. However, SB2193 did not reduce spontaneous seizures in the Scn1a +/- mouse model of Dravet syndrome, nor absence seizures in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS). Surprisingly, SB2193 appeared to increase the incidence and duration of spike-and-wave discharges in GAERS animals over a 4 h recording period. Conclusion: These results show that MEPIRAPIM analogues provide novel chemical scaffolds to advance Cav3 inhibitors against certain seizure types.
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Affiliation(s)
- Thomas Harman
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Michael Udoh
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Dan L. McElroy
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lyndsey L. Anderson
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Jack Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Chris Bladen
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peter T. Doohan
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Quentin Greba
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robert B. Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - John G. Howland
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jonathon C. Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Jonathon C. Arnold,
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Mavashov A, Brusel M, Liu J, Woytowicz V, Bae H, Chen YH, Dani VS, Cardenal-Muñoz E, Spinosa V, Aibar JÁ, Rubinstein M. Heat-induced seizures, premature mortality, and hyperactivity in a novel Scn1a nonsense model for Dravet syndrome. Front Cell Neurosci 2023; 17:1149391. [PMID: 37206664 PMCID: PMC10191256 DOI: 10.3389/fncel.2023.1149391] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/05/2023] [Indexed: 05/21/2023] Open
Abstract
Dravet syndrome (Dravet) is a severe congenital developmental genetic epilepsy caused by de novo mutations in the SCN1A gene. Nonsense mutations are found in ∼20% of the patients, and the R613X mutation was identified in multiple patients. Here we characterized the epileptic and non-epileptic phenotypes of a novel preclinical Dravet mouse model harboring the R613X nonsense Scn1a mutation. Scn1aWT/R613X mice, on a mixed C57BL/6J:129S1/SvImJ background, exhibited spontaneous seizures, susceptibility to heat-induced seizures, and premature mortality, recapitulating the core epileptic phenotypes of Dravet. In addition, these mice, available as an open-access model, demonstrated increased locomotor activity in the open-field test, modeling some non-epileptic Dravet-associated phenotypes. Conversely, Scn1aWT/R613X mice, on the pure 129S1/SvImJ background, had a normal life span and were easy to breed. Homozygous Scn1aR613X/R613X mice (pure 129S1/SvImJ background) died before P16. Our molecular analyses of hippocampal and cortical expression demonstrated that the premature stop codon induced by the R613X mutation reduced Scn1a mRNA and NaV1.1 protein levels to ∼50% in heterozygous Scn1aWT/R613X mice (on either genetic background), with marginal expression in homozygous Scn1aR613X/R613X mice. Together, we introduce a novel Dravet model carrying the R613X Scn1a nonsense mutation that can be used to study the molecular and neuronal basis of Dravet, as well as the development of new therapies associated with SCN1A nonsense mutations in Dravet.
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Affiliation(s)
- Anat Mavashov
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Marina Brusel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jiaxing Liu
- Tevard Biosciences, Cambridge, MA, United States
| | | | - Haneui Bae
- Tevard Biosciences, Cambridge, MA, United States
| | | | | | | | | | | | - Moran Rubinstein
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Goldschleger Eye Research Institute, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Moran Rubinstein,
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Bahceci D, Anderson LL, Kevin RC, Doohan PT, Arnold JC. Hyperthermia-Induced Seizures Enhance Brain Concentrations of the Endocannabinoid-Related Linoleoyl Glycerols in a Scn1a+/- Mouse Model of Dravet Syndrome. Cannabis Cannabinoid Res 2022. [PMID: 36269656 DOI: 10.1089/can.2022.0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction: The endocannabinoid system contributes to the homeostatic response to seizure activity in epilepsy, a disease of brain hyperexcitability. Indeed, studies using conventional epilepsy models have shown that seizures increase endocannabinoids in the brain. However, it is unknown whether endocannabinoids and structurally related fatty acid amides and monoacylglycerols are similarly released in response to acute seizures in animal models of drug-resistant epilepsy. Therefore, in this study, we investigated whether a hyperthermia-induced seizure increased concentrations of endocannabinoids and related signaling lipids in the Scn1a+/- mouse model of Dravet syndrome. Materials and Methods: We compared hippocampal concentrations of the major endocannabinoids and related monoglycerols and N-acylethanolamines in wild-type mice, naïve Scn1a+/- mice, and Scn1a+/- mice primed with a single, hyperthermia-induced, generalized tonic-clonic seizure. Samples were collected 5 and 60 min following the seizure and then analyzed with LC-MS/MS. Results: We found that a hyperthermia-induced seizure in Scn1a+/- mice did not affect hippocampal concentrations of the major endocannabinoids, 2-AG and anandamide, or the N-acylethanolamines studied, although the sampling of tissue 5 min postseizure may have been too late to capture any effect on these lipids. Heterozygous deletion of Scn1a alone did not affect these lipid signaling molecules. Notably, however, we found that a hyperthermia-induced seizure significantly increased hippocampal concentrations of the monoacylglycerols, 2-linoleoyl glycerol (2-LG) and 1-linoleoyl glycerol (1-LG), in Scn1a+/- mice. Conclusions: Our results show the unprecedented elevation of the lesser-studied endocannabinoid-related monoacylglycerols, 2-LG and 1-LG, following a hyperthermia-induced seizure in a mouse model of Dravet syndrome. Future research is needed to comprehensively explore the function of these lipid signaling molecules during seizure activity and whether their actions can be exploited to develop new therapeutics.
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Affiliation(s)
- Dilara Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown , Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown , Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, Australia
| | - Richard C Kevin
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown , Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, Australia
| | - Peter T Doohan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown , Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, Australia
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown , Australia.,Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, Australia
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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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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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