1
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Ehara T, Ohka F, Motomura K, Saito R. Epilepsy in Patients with Gliomas. Neurol Med Chir (Tokyo) 2024; 64:253-260. [PMID: 38839295 PMCID: PMC11304448 DOI: 10.2176/jns-nmc.2023-0299] [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: 12/22/2023] [Accepted: 03/02/2024] [Indexed: 06/07/2024] Open
Abstract
Brain tumor-related epilepsy (BTRE) is a complication that significantly impairs the quality of life and course of treatment of patients with brain tumors. Several recent studies have shed further light on the mechanisms and pathways by which genes and biological molecules in the tumor microenvironment can cause epilepsy. Moreover, epileptic seizures have been found to promote the growth of brain tumors, making the control of epilepsy a critical factor in treating brain tumors. In this study, we summarize the previous research and recent findings concerning BTRE. Expectedly, a deeper understanding of the underlying genetic and molecular mechanisms leads to safer and more effective treatments for suppressing epileptic symptoms and tumor growth.
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Affiliation(s)
- Takuro Ehara
- Department of Neuro-Oncology/Neurosurgery, International Medical Center, Saitama Medical University
| | - Fumiharu Ohka
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
| | - Kazuya Motomura
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
| | - Ryuta Saito
- Department of Neurosurgery, Nagoya University Graduate School of Medicine
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2
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Pineau L, Buhler E, Tarhini S, Bauer S, Crepel V, Watrin F, Cardoso C, Represa A, Szepetowski P, Burnashev N. Pathogenic MTOR somatic variant causing focal cortical dysplasia drives hyperexcitability via overactivation of neuronal GluN2C N-methyl-D-aspartate receptors. Epilepsia 2024; 65:2111-2126. [PMID: 38717560 DOI: 10.1111/epi.18000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 07/17/2024]
Abstract
OBJECTIVE Genetic variations in proteins of the mechanistic target of rapamycin (mTOR) pathway cause a spectrum of neurodevelopmental disorders often associated with brain malformations and with intractable epilepsy. The mTORopathies are characterized by hyperactive mTOR pathway and comprise tuberous sclerosis complex (TSC) and focal cortical dysplasia (FCD) type II. How hyperactive mTOR translates into abnormal neuronal activity and hypersynchronous network remains to be better understood. Previously, the role of upregulated GluN2C-containing glutamate-gated N-methyl-D-aspartate receptors (NMDARs) has been demonstrated for germline defects in the TSC genes. Here, we questioned whether this mechanism would expand to other mTORopathies in the different context of a somatic genetic variation of the MTOR protein recurrently found in FCD type II. METHODS We used a rat model of FCD created by in utero electroporation of neural progenitors of dorsal telencephalon with expression vectors encoding either the wild-type or the pathogenic MTOR variant (p.S2215F). In this mosaic configuration, patch-clamp whole-cell recordings of the electroporated, spiny stellate neurons and extracellular recordings of the electroporated areas were performed in neocortical slices. Selective inhibitors were used to target mTOR activity and GluN2C-mediated currents. RESULTS Neurons expressing the mutant protein displayed an excessive activation of GluN2C NMDAR-mediated spontaneous excitatory postsynaptic currents. GluN2C-dependent increase in spontaneous spiking activity was detected in the area of electroporated neurons in the mutant condition and was restricted to a critical time window between postnatal days P9 and P20. SIGNIFICANCE Somatic MTOR pathogenic variant recurrently found in FCD type II resulted in overactivation of GluN2C-mediated neuronal NMDARs in neocortices of rat pups. The related and time-restricted local hyperexcitability was sensitive to subunit GluN2C-specific blockade. Our study suggests that GluN2C-related pathomechanisms might be shared in common by mTOR-related brain disorders.
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Affiliation(s)
- Louison Pineau
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Emmanuelle Buhler
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Sarah Tarhini
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Sylvian Bauer
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Valérie Crepel
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Françoise Watrin
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Carlos Cardoso
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Alfonso Represa
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Pierre Szepetowski
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
| | - Nail Burnashev
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale, Aix-Marseille University, Marseille, France
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3
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Ravizza T, Scheper M, Di Sapia R, Gorter J, Aronica E, Vezzani A. mTOR and neuroinflammation in epilepsy: implications for disease progression and treatment. Nat Rev Neurosci 2024; 25:334-350. [PMID: 38531962 DOI: 10.1038/s41583-024-00805-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2024] [Indexed: 03/28/2024]
Abstract
Epilepsy remains a major health concern as anti-seizure medications frequently fail, and there is currently no treatment to stop or prevent epileptogenesis, the process underlying the onset and progression of epilepsy. The identification of the pathological processes underlying epileptogenesis is instrumental to the development of drugs that may prevent the generation of seizures or control pharmaco-resistant seizures, which affect about 30% of patients. mTOR signalling and neuroinflammation have been recognized as critical pathways that are activated in brain cells in epilepsy. They represent a potential node of biological convergence in structural epilepsies with either a genetic or an acquired aetiology. Interventional studies in animal models and clinical studies give strong support to the involvement of each pathway in epilepsy. In this Review, we focus on available knowledge about the pathophysiological features of mTOR signalling and the neuroinflammatory brain response, and their interactions, in epilepsy. We discuss mitigation strategies for each pathway that display therapeutic effects in experimental and clinical epilepsy. A deeper understanding of these interconnected molecular cascades could enhance our strategies for managing epilepsy. This could pave the way for new treatments to fill the gaps in the development of preventative or disease-modifying drugs, thus overcoming the limitations of current symptomatic medications.
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Affiliation(s)
- Teresa Ravizza
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Rossella Di Sapia
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Jan Gorter
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands.
| | - Annamaria Vezzani
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy.
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4
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Pineau L, Burnashev N. Functional Analysis of NMDAR Subunit Components in Postsynaptic Currents of Identified Cells and Synapses in Brain Slices. Methods Mol Biol 2024; 2799:139-150. [PMID: 38727906 DOI: 10.1007/978-1-0716-3830-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
Epilepsy is one of the most represented neurological diseases worldwide. However, in many cases, the precise molecular mechanisms of epileptogenesis and ictiogenesis are unknown. Because of their important role in synaptic function and neuronal excitability, NMDA receptors are implicated in various epileptogenic mechanisms. Most of these are subunit specific and require a precise analysis of the subunit composition of the NMDARs implicated. Here, we describe an express electrophysiological method to analyze the contribution of NMDAR subunits to spontaneous postsynaptic activity in identified cells in brain slices using patch clamp whole cell recordings.
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Affiliation(s)
- Louison Pineau
- Mediterranean Institute of Neurobiology (INMED), INSERM, Aix-Marseille University, Marseille, France
| | - Nail Burnashev
- Mediterranean Institute of Neurobiology (INMED), INSERM, Aix-Marseille University, Marseille, France.
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5
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Specchio N, Nabbout R, Aronica E, Auvin S, Benvenuto A, de Palma L, Feucht M, Jansen F, Kotulska K, Sarnat H, Lagae L, Jozwiak S, Curatolo P. Updated clinical recommendations for the management of tuberous sclerosis complex associated epilepsy. Eur J Paediatr Neurol 2023; 47:25-34. [PMID: 37669572 DOI: 10.1016/j.ejpn.2023.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/07/2023]
Abstract
Children with tuberous sclerosis complex (TSC), may experience a variety of seizure types in the first year of life, most often focal seizure sand epileptic spasms. Drug resistance is seen early in many patients, and the management of TSC associated epilepsy remain a major challenge for clinicians. In 2018 clinical recommendations for the management of TSC associated epilepsy were published by a panel of European experts. In the last five years considerable progress has been made in understanding the neurobiology of epileptogenesis and three interventional randomized controlled trials have changed the therapeutic approach for the management of TSC associated epilepsy. Pre-symptomatic treatment with vigabatrin may delay seizure onset, may reduce seizure severity and reduce the risk of epileptic encephalopathy. The efficacy of mTOR inhibition with adjunctive everolimus was documented in patients with TSC associated refractory seizures and cannabidiol could be another therapeutic option. Epilepsy surgery has significantly improved seizure outcome in selected patients and should be considered early in all patients with drug resistant epilepsy. There is a need to identify patients who may have a higher risk of developing epilepsy and autism spectrum disorder (ASD). In the recent years significant progress has been made owing to the early identification of risk factors for the development of drug-resistant epilepsy. Better understanding of the mechanism underlying epileptogenesis may improve the management for TSC-related epilepsy. Developmental neurobiology and neuropathology give opportunities for the implementation of concepts related to clinical findings, and an early genetic diagnosis and use of EEG and MRI biomarkers may improve the development of pre-symptomatic and disease-modifying strategies.
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Affiliation(s)
- Nicola Specchio
- Clinical and Experimental Neurology, Bambino Gesu' Children's Hospital IRCCS, Full Member of European Reference Network on Rare and Complex Epilepsies EpiCARE, Rome, Italy.
| | - Rima Nabbout
- Department of Pediatric Neurology, Necker Enfants Malades Hospital, Université Paris Cité, Member of the European Reference Network on Rare and Complex Epilepsies EpiCARE, INSERM U1163, Institut Imagine, Paris, France
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Department of (Neuro)Pathology, Amsterdam, Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, the Netherlands
| | - Stephane Auvin
- APHP, Service de Neurologie Pédiatrique, Centre Epilepsies Rares, Member of the European Reference Network on Rare and Complex Epilepsies EpiCARE, Hôpital Robert Debré, Paris, France; Université Paris-Cité, INSERM NeuroDiderot, Paris, France; Institut Universitaire de France (IUF), Paris, France
| | | | - Luca de Palma
- Clinical and Experimental Neurology, Bambino Gesu' Children's Hospital IRCCS, Full Member of European Reference Network on Rare and Complex Epilepsies EpiCARE, Rome, Italy
| | - Martha Feucht
- Epilepsy Center, Department of Pediatrics, Medical University Vienna, Austria
| | - Floor Jansen
- Department of Pediatric Neurology, Brain Center UMC Utrecht, the Netherlands
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, The Children's Memorial Health Institute, Warsaw, Poland
| | - Harvey Sarnat
- Department of Paediatrics (Neurology), Pathology and Laboratory Medicine (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - Lieven Lagae
- Department of Paediatric Neurology, University of Leuven, Leuven, Belgium
| | - Sergiusz Jozwiak
- Research Department, The Children's Memorial Health Institute, ERN EPICARE, Warsaw, Poland
| | - Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University, Rome, Italy
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6
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D’Erasmo M, Akins NS, Ma P, Jing Y, Swanger SA, Sharma SK, Bartsch PW, Menaldino DS, Arcoria PJ, Bui TT, Pons-Bennaceur A, Le P, Allen JP, Ullman EZ, Nocilla KA, Zhang J, Perszyk RE, Kim S, Acker TM, Taz A, Burton SL, Coe K, Fritzemeier RG, Burnashev N, Yuan H, Liotta DC, Traynelis SF. Development of a Dihydroquinoline-Pyrazoline GluN2C/2D-Selective Negative Allosteric Modulator of the N-Methyl-d-aspartate Receptor. ACS Chem Neurosci 2023; 14:3059-3076. [PMID: 37566734 PMCID: PMC10485906 DOI: 10.1021/acschemneuro.3c00181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
Subunit-selective inhibition of N-methyl-d-aspartate receptors (NMDARs) is a promising therapeutic strategy for several neurological disorders, including epilepsy, Alzheimer's and Parkinson's disease, depression, and acute brain injury. We previously described the dihydroquinoline-pyrazoline (DQP) analogue 2a (DQP-26) as a potent NMDAR negative allosteric modulator with selectivity for GluN2C/D over GluN2A/B. However, moderate (<100-fold) subunit selectivity, inadequate cell-membrane permeability, and poor brain penetration complicated the use of 2a as an in vivo probe. In an effort to improve selectivity and the pharmacokinetic profile of the series, we performed additional structure-activity relationship studies of the succinate side chain and investigated the use of prodrugs to mask the pendant carboxylic acid. These efforts led to discovery of the analogue (S)-(-)-2i, also referred to as (S)-(-)-DQP-997-74, which exhibits >100- and >300-fold selectivity for GluN2C- and GluN2D-containing NMDARs (IC50 0.069 and 0.035 μM, respectively) compared to GluN2A- and GluN2B-containing receptors (IC50 5.2 and 16 μM, respectively) and has no effects on AMPA, kainate, or GluN1/GluN3 receptors. Compound (S)-(-)-2i is 5-fold more potent than (S)-2a. In addition, compound 2i shows a time-dependent enhancement of inhibitory actions at GluN2C- and GluN2D-containing NMDARs in the presence of the agonist glutamate, which could attenuate hypersynchronous activity driven by high-frequency excitatory synaptic transmission. Consistent with this finding, compound 2i significantly reduced the number of epileptic events in a murine model of tuberous sclerosis complex (TSC)-induced epilepsy that is associated with upregulation of the GluN2C subunit. Thus, 2i represents a robust tool for the GluN2C/D target validation. Esterification of the succinate carboxylate improved brain penetration, suggesting a strategy for therapeutic development of this series for NMDAR-associated neurological conditions.
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Affiliation(s)
- Michael
P. D’Erasmo
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Nicholas S. Akins
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Peipei Ma
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Yao Jing
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Sharon A. Swanger
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Savita K. Sharma
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Perry W. Bartsch
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - David S. Menaldino
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Paul J. Arcoria
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Thi-Thien Bui
- INMED,
INSERM, Aix Marseille University, 13284 Marseille, France
| | | | - Phuong Le
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - James P. Allen
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Elijah Z. Ullman
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Kelsey A. Nocilla
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Jing Zhang
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Riley E. Perszyk
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Sukhan Kim
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Timothy M. Acker
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Azmain Taz
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Samantha L. Burton
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Kevin Coe
- Janssen
Research & Development, LLC, San Diego, California 92121, United States
| | | | - Nail Burnashev
- INMED,
INSERM, Aix Marseille University, 13284 Marseille, France
| | - Hongjie Yuan
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
| | - Dennis C. Liotta
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Stephen F. Traynelis
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
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7
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Luhmann HJ. Malformations-related neocortical circuits in focal seizures. Neurobiol Dis 2023; 178:106018. [PMID: 36706927 DOI: 10.1016/j.nbd.2023.106018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/18/2023] [Accepted: 01/23/2023] [Indexed: 01/25/2023] Open
Abstract
This review article gives an overview on the molecular, cellular and network mechanisms underlying focal seizures in neocortical networks with developmental malformations. Neocortical malformations comprise a large variety of structural abnormalities associated with epilepsy and other neurological and psychiatric disorders. Genetic or acquired disorders of neocortical cell proliferation, neuronal migration and/or programmed cell death may cause pathologies ranging from the expression of dysmorphic neurons and heterotopic cell clusters to abnormal layering and cortical misfolding. After providing a brief overview on the pathogenesis and structure of neocortical malformations in humans, animal models are discussed and how they contributed to our understanding on the mechanisms of neocortical hyperexcitability associated with developmental disorders. State-of-the-art molecular biological and electrophysiological techniques have been also used in humans and on resectioned neocortical tissue of epileptic patients and provide deep insights into the subcellular, cellular and network mechanisms contributing to focal seizures. Finally, a brief outlook is given how novel models and methods can shape translational research in the near future.
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Affiliation(s)
- Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz, Germany.
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8
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Eichmüller OL, Knoblich JA. Human cerebral organoids - a new tool for clinical neurology research. Nat Rev Neurol 2022; 18:661-680. [PMID: 36253568 PMCID: PMC9576133 DOI: 10.1038/s41582-022-00723-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2022] [Indexed: 11/21/2022]
Abstract
The current understanding of neurological diseases is derived mostly from direct analysis of patients and from animal models of disease. However, most patient studies do not capture the earliest stages of disease development and offer limited opportunities for experimental intervention, so rarely yield complete mechanistic insights. The use of animal models relies on evolutionary conservation of pathways involved in disease and is limited by an inability to recreate human-specific processes. In vitro models that are derived from human pluripotent stem cells cultured in 3D have emerged as a new model system that could bridge the gap between patient studies and animal models. In this Review, we summarize how such organoid models can complement classical approaches to accelerate neurological research. We describe our current understanding of neurodevelopment and how this process differs between humans and other animals, making human-derived models of disease essential. We discuss different methodologies for producing organoids and how organoids can be and have been used to model neurological disorders, including microcephaly, Zika virus infection, Alzheimer disease and other neurodegenerative disorders, and neurodevelopmental diseases, such as Timothy syndrome, Angelman syndrome and tuberous sclerosis. We also discuss the current limitations of organoid models and outline how organoids can be used to revolutionize research into the human brain and neurological diseases.
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Affiliation(s)
- Oliver L Eichmüller
- IMBA-Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
- University of Heidelberg, Heidelberg, Germany
| | - Juergen A Knoblich
- IMBA-Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria.
- Medical University of Vienna, Department of Neurology, Vienna, Austria.
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9
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Gill BJA, Khan FA, Goldberg AR, Merricks EM, Wu X, Sosunov AA, Sudhakar TD, Dovas A, Lado W, Michalak AJ, Teoh JJ, Liou JY, Frankel WN, McKhann GM, Canoll P, Schevon CA. Single unit analysis and wide-field imaging reveal alterations in excitatory and inhibitory neurons in glioma. Brain 2022; 145:3666-3680. [PMID: 35552612 PMCID: PMC10202150 DOI: 10.1093/brain/awac168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 02/05/2022] [Accepted: 04/27/2022] [Indexed: 11/14/2022] Open
Abstract
While several studies have attributed the development of tumour-associated seizures to an excitatory-inhibitory imbalance, we have yet to resolve the spatiotemporal interplay between different types of neuron in glioma-infiltrated cortex. Herein, we combined methods for single unit analysis of microelectrode array recordings with wide-field optical mapping of Thy1-GCaMP pyramidal cells in an ex vivo acute slice model of diffusely infiltrating glioma. This enabled simultaneous tracking of individual neurons from both excitatory and inhibitory populations throughout seizure-like events. Moreover, our approach allowed for observation of how the crosstalk between these neurons varied spatially, as we recorded across an extended region of glioma-infiltrated cortex. In tumour-bearing slices, we observed marked alterations in single units classified as putative fast-spiking interneurons, including reduced firing, activity concentrated within excitatory bursts and deficits in local inhibition. These results were correlated with increases in overall excitability. Mechanistic perturbation of this system with the mTOR inhibitor AZD8055 revealed increased firing of putative fast-spiking interneurons and restoration of local inhibition, with concomitant decreases in overall excitability. Altogether, our findings suggest that diffusely infiltrating glioma affect the interplay between excitatory and inhibitory neuronal populations in a reversible manner, highlighting a prominent role for functional mechanisms linked to mTOR activation.
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Affiliation(s)
- Brian J A Gill
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Farhan A Khan
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander R Goldberg
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Xiaoping Wu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Tejaswi D Sudhakar
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Athanassios Dovas
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wudu Lado
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Andrew J Michalak
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Jie Teoh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jyun-you Liou
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
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10
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Gataullina S, Galvani G, Touchet S, Nous C, Lemaire E, Laschet J, Chiron C, Dulac O, Dossi E, Brion JD, Messaoudi S, Alami M, Huberfeld G. GluN2C
selective inhibition is a target to develop new antiepileptic compounds. Epilepsia 2022; 63:2911-2924. [PMID: 36054371 DOI: 10.1111/epi.17396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Many early-onset epilepsies present as developmental and epileptic encephalopathy associated with refractory seizures, altered psychomotor development, and disorganized interictal cortical activity. Abnormal upregulation of specific N-methyl-d-aspartate receptor (NMDA-R) subunits is being disentangled as one of the mechanisms of severe early-onset epilepsies. In tuberous sclerosis complex (TSC), upregulation of the GluN2C subunit of the NMDA-R with slow deactivation kinetic results in increased neuronal excitation and synchronization. METHODS Starting from an available GluN2C/D antagonist, NMDA-R-modulating compounds were developed and screened using a patch clamp on neuronal culture to select those with the strongest inhibitory effect on glutamatergic NMDA currents. For these selected compounds, blood pharmacokinetics and passage through the blood-brain barrier were studied. We tested the effect of the most promising compounds on epileptic activity in Tsc1+/- mice brain slices with multielectrode array, and then in vivo at postnatal ages P14-P17, comparable with the usual age at epilepsy onset in human TSC. RESULTS Using a double-electrode voltage clamp on isolated NMDA currents, we identified the most prominent antagonists of the GluN2C subunit with no effect on GluN2A as a means of preventing side effects. The best compound passing through the blood-brain barrier was selected. Applied in vivo in six Tsc1+/- mice at P14-P17, this compound reduced or completely stopped spontaneous seizures in four of them, and decreased the background activity disorganization. Furthermore, ictal-like discharges stopped on a human brain sample from an infant with epilepsy due to TSC. INTERPRETATION Subunit-selective inhibition is a valuable target for developing drugs for severe epilepsies resulting from an upregulation of NMDA-R subunit-mediated transmission.
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Affiliation(s)
- S. Gataullina
- Service d’explorations fonctionnelles multidisciplinaires Centre de médecine du sommeil, Antoine Béclère Hospital, APHP, Université Paris Saclay Clamart France
| | - G. Galvani
- AdPueriVitam (APV), Antony France
- Université de Lorraine CNRS, L2CM Nancy France
| | - S. Touchet
- AdPueriVitam (APV), Antony France
- Université de Lorraine CNRS, L2CM Nancy France
| | - C. Nous
- Institut de la Vision, UFR Sciences et Technologies Paris France
| | | | | | - C. Chiron
- Inserm U1141, Paris & APHP, Neuropediatrics, Necker Hospital Paris France
| | - O. Dulac
- AdPueriVitam (APV), Antony France
| | - E. Dossi
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Université PSL Paris France
| | - J. D. Brion
- Université Paris‐Saclay CNRS UMR 8076, BioCIS Châtenay‐Malabry France
| | - S. Messaoudi
- Université Paris‐Saclay CNRS UMR 8076, BioCIS Châtenay‐Malabry France
| | - M. Alami
- Université Paris‐Saclay CNRS UMR 8076, BioCIS Châtenay‐Malabry France
| | - G. Huberfeld
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Université PSL Paris France
- Neurology Department, Hôpital Fondation Adolphe de Rothschild Paris France
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11
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Raptor downregulation rescues neuronal phenotypes in mouse models of Tuberous Sclerosis Complex. Nat Commun 2022; 13:4665. [PMID: 35945201 PMCID: PMC9363483 DOI: 10.1038/s41467-022-31961-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 07/08/2022] [Indexed: 12/16/2022] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations in the TSC1 or TSC2 genes, which encode proteins that negatively regulate mTOR complex 1 (mTORC1) signaling. Current treatment strategies focus on mTOR inhibition with rapamycin and its derivatives. While effective at improving some aspects of TSC, chronic rapamycin inhibits both mTORC1 and mTORC2 and is associated with systemic side-effects. It is currently unknown which mTOR complex is most relevant for TSC-related brain phenotypes. Here we used genetic strategies to selectively reduce neuronal mTORC1 or mTORC2 activity in mouse models of TSC. We find that reduction of the mTORC1 component Raptor, but not the mTORC2 component Rictor, rebalanced mTOR signaling in Tsc1 knock-out neurons. Raptor reduction was sufficient to improve several TSC-related phenotypes including neuronal hypertrophy, macrocephaly, impaired myelination, network hyperactivity, and premature mortality. Raptor downregulation represents a promising potential therapeutic intervention for the neurological manifestations of TSC.
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12
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Wu X, Sosunov AA, Lado W, Teoh JJ, Ham A, Li H, Al-Dalahmah O, Gill BJA, Arancio O, Schevon CA, Frankel WN, McKhann GM, Sulzer D, Goldman JE, Tang G. Synaptic hyperexcitability of cytomegalic pyramidal neurons contributes to epileptogenesis in tuberous sclerosis complex. Cell Rep 2022; 40:111085. [PMID: 35858542 PMCID: PMC9376014 DOI: 10.1016/j.celrep.2022.111085] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 02/15/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a developmental disorder associated with epilepsy, autism, and cognitive impairment. Despite inactivating mutations in the TSC1 or TSC2 genes and hyperactive mechanistic target of rapamycin (mTOR) signaling, the mechanisms underlying TSC-associated neurological symptoms remain incompletely understood. Here we generate a Tsc1 conditional knockout (CKO) mouse model in which Tsc1 inactivation in late embryonic radial glia causes social and cognitive impairment and spontaneous seizures. Tsc1 depletion occurs in a subset of layer 2/3 cortical pyramidal neurons, leading to development of cytomegalic pyramidal neurons (CPNs) that mimic dysplastic neurons in human TSC, featuring abnormal dendritic and axonal overgrowth, enhanced glutamatergic synaptic transmission, and increased susceptibility to seizure-like activities. We provide evidence that enhanced synaptic excitation in CPNs contributes to cortical hyperexcitability and epileptogenesis. In contrast, astrocytic regulation of synapse formation and synaptic transmission remains unchanged after late embryonic radial glial Tsc1 inactivation, and astrogliosis evolves secondary to seizures. Wu et al. demonstrate that Tsc1 inactivation in late embryonic radial glial cells (RGCs) produces cytomegalic pyramidal neurons that mimic TSC-like dysplastic neurons. They find that enhanced excitatory synaptic transmission in Tsc1-null cytomegalic pyramidal neurons contributes to cortical hyperexcitability and epileptogenesis.
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Affiliation(s)
- Xiaoping Wu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wudu Lado
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Jie Teoh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ahrom Ham
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hongyu Li
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Osama Al-Dalahmah
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Brian J A Gill
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David Sulzer
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pharmacology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guomei Tang
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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13
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Laporte MH, Chi KI, Caudal LC, Zhao N, Schwarz Y, Rolland M, Martinez-Hernandez J, Martineau M, Chatellard C, Denarier E, Mercier V, Lemaître F, Blot B, Moutaux E, Cazorla M, Perrais D, Lanté F, Bruns D, Fraboulet S, Hemming FJ, Kirchhoff F, Sadoul R. Alix is required for activity-dependent bulk endocytosis at brain synapses. PLoS Biol 2022; 20:e3001659. [PMID: 35658004 PMCID: PMC9200306 DOI: 10.1371/journal.pbio.3001659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 06/15/2022] [Accepted: 05/04/2022] [Indexed: 12/04/2022] Open
Abstract
In chemical synapses undergoing high frequency stimulation, vesicle components can be retrieved from the plasma membrane via a clathrin-independent process called activity-dependent bulk endocytosis (ADBE). Alix (ALG-2-interacting protein X/PDCD6IP) is an adaptor protein binding to ESCRT and endophilin-A proteins which is required for clathrin-independent endocytosis in fibroblasts. Alix is expressed in neurons and concentrates at synapses during epileptic seizures. Here, we used cultured neurons to show that Alix is recruited to presynapses where it interacts with and concentrates endophilin-A during conditions triggering ADBE. Using Alix knockout (ko) neurons, we showed that this recruitment, which requires interaction with the calcium-binding protein ALG-2, is necessary for ADBE. We also found that presynaptic compartments of Alix ko hippocampi display subtle morphological defects compatible with flawed synaptic activity and plasticity detected electrophysiologically. Furthermore, mice lacking Alix in the forebrain undergo less seizures during kainate-induced status epilepticus and reduced propagation of the epileptiform activity. These results thus show that impairment of ADBE due to the lack of neuronal Alix leads to abnormal synaptic recovery during physiological or pathological repeated stimulations. The adaptor protein Alix (PDCD6IP) is necessary for membrane shaping underlying various biological processes including endocytosis. This study shows that Alix mediates activity-dependent bulk endocytosis and is required for correct synaptic physiology under normal and pathological conditions.
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Affiliation(s)
- Marine H. Laporte
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Department of Cell Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (MHL); (FK); (RS)
| | - Kwang Il Chi
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Laura C. Caudal
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Na Zhao
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Yvonne Schwarz
- Molecular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Marta Rolland
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - José Martinez-Hernandez
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad Castilla-La Mancha, Albacete, Spain
| | - Magalie Martineau
- Interdisciplinary Institute for Neuroscience, University of Bordeaux-CNRS UMR 5297, Bordeaux, France
| | - Christine Chatellard
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Institut de Biologie Structurale, University Grenoble Alpes—CNRS-CEA UMR 5075, Grenoble, France
| | - Eric Denarier
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Vincent Mercier
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Florent Lemaître
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Département des Neurosciences, Centre de Recherche du centre hospitalier de Montréal, Canada
| | - Béatrice Blot
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Eve Moutaux
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Maxime Cazorla
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Institut de Neuroscience la Timone, CNRS UMR7289, Marseille, France
| | - David Perrais
- Interdisciplinary Institute for Neuroscience, University of Bordeaux-CNRS UMR 5297, Bordeaux, France
| | - Fabien Lanté
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Dieter Bruns
- Molecular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Sandrine Fraboulet
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Institute for Advanced Biosciences, Univ. Grenoble Alpes—INSERM U1209—CNRS UMR 5309, Grenoble, France
| | - Fiona J. Hemming
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
- * E-mail: (MHL); (FK); (RS)
| | - Rémy Sadoul
- Grenoble Institute Neurosciences, University Grenoble Alpes—INSERM U1216—CEA, Grenoble, France
- Institut de Biologie Structurale, University Grenoble Alpes—CNRS-CEA UMR 5075, Grenoble, France
- * E-mail: (MHL); (FK); (RS)
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14
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Genetic pathogenesis of the epileptogenic lesions in Tuberous Sclerosis Complex: Therapeutic targeting of the mTOR pathway. Epilepsy Behav 2022; 131:107713. [PMID: 33431351 DOI: 10.1016/j.yebeh.2020.107713] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022]
Abstract
Tuberous sclerosis complex (TSC) is a genetic multisystem disease due to the mutation in one of the two genes TSC1 and TSC2, affecting several organs and systems and carrying a significant risk of early onset and refractory seizures. The pathogenesis of this complex disorder is now well known, with most of TSC-related manifestations being a consequence of the overactivation of the mammalian Target of Rapamycin (mTOR) complex. The discovery of this underlying mechanism paved the way for the use of a class of drugs called mTOR inhibitors including rapamycin and everolimus and specifically targeting this pathway. Rapamycin has been widely used in different animal models of TSC-related epilepsy and proved to be able not only to suppress seizures but also to prevent the development of epilepsy, thus demonstrating an antiepileptogenic potential. In some models, it also showed some benefit on neuropsychiatric manifestations associated with TSC. Everolimus has recently been approved by the US Food and Drug Administration and the European Medical Agency for the treatment of refractory seizures associated with TSC starting from the age of 2 years. It demonstrated a clear benefit when compared to placebo on reducing the frequency of different seizure types and exerting a higher effect in younger children. In conclusion, mTOR cascade can be a potentially major cause of TSC-associated epilepsy and neurodevelopmental disability, and additional research should investigate if early suppression of abnormal mTOR signal with mTOR inhibitors before seizure onset can be a more efficient approach and an effective antiepileptogenic and disease-modifying strategy in infants with TSC.
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15
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Keeping Excitation-Inhibition Ratio in Balance. Int J Mol Sci 2022; 23:ijms23105746. [PMID: 35628556 PMCID: PMC9145842 DOI: 10.3390/ijms23105746] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022] Open
Abstract
Unrelated genetic mutations can lead to convergent manifestations of neurological disorders with similar behavioral phenotypes. Experimental data frequently show a lack of dramatic changes in neuroanatomy, indicating that the key cause of symptoms might arise from impairment in the communication between neurons. A transient imbalance between excitatory (glutamatergic) and inhibitory (GABAergic) synaptic transmission (the E/I balance) during early development is generally considered to underlie the development of several neurological disorders in adults. However, the E/I ratio is a multidimensional variable. Synaptic contacts are highly dynamic and the actual strength of synaptic projections is determined from the balance between synaptogenesis and synaptic elimination. During development, relatively slow postsynaptic receptors are replaced by fast ones that allow for fast stimulus-locked excitation/inhibition. Using the binomial model of synaptic transmission allows for the reassessing of experimental data from different mouse models, showing that a transient E/I shift is frequently counterbalanced by additional pre- and/or postsynaptic changes. Such changes—for instance, the slowing down of postsynaptic currents by means of immature postsynaptic receptors—stabilize the average synaptic strength, but impair the timing of information flow. Compensatory processes and/or astrocytic signaling may represent possible targets for medical treatments of different disorders directed to rescue the proper information processing.
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16
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Ko A, Sim NS, Choi HS, Yang D, Kim SH, Lee JS, Kim DS, Lee JH, Kim HD, Kang HC. Efficacy of the Ketogenic Diet for Pediatric Epilepsy According to the Presence of Detectable Somatic mTOR Pathway Mutations in the Brain. J Clin Neurol 2022; 18:71-78. [PMID: 35021279 PMCID: PMC8762511 DOI: 10.3988/jcn.2022.18.1.71] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/23/2022] Open
Abstract
Background and Purpose A multifactorial antiepileptic mechanism underlies the ketogenic diet (KD), and one of the proposed mechanisms of action is that the KD inhibits the mammalian target of rapamycin (mTOR) pathway. To test this clinically, this study aimed to determine the efficacy of the KD in patients with pathologically confirmed focal cortical dysplasia (FCD) due to genetically identifiable mTOR pathway dysregulation. Methods A cohort of patients with pathologically confirmed FCD after epilepsy surgery and who were screened for the presence of germline and somatic mutations related to the mTOR pathway in peripheral blood and resected brain tissue was constructed prospectively. A retrospective review of the efficacy of the prior KD in these patients was performed. Results Twenty-five patients with pathologically confirmed FCD and who were screened for the presence of detectable somatic mTOR pathway mutations had received a sufficient KD. Twelve of these patients (48.0%) had germline or somatic detectable mTOR pathway mutations. A response was defined as a ≥50% reduction in seizure frequency. The efficacy of the KD after 3 months of dietary therapy was superior in patients with detectable mTOR pathway mutations than in patients without detectable mTOR pathway mutations, although the difference was not statistically significant (responder rates of 58.3% vs. 38.5%, p=0.434). Conclusions A greater proportion of patients with mTOR pathway responded to the KD, but there was no statistically significant difference in efficacy of the KD between patients with and without detectable mTOR pathway mutations. Further study is warranted due to the smallness of the sample and the limited number of mTOR pathway genes tested in this study.
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Affiliation(s)
- Ara Ko
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
| | - Nam Suk Sim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Han Som Choi
- Department of Pediatrics, Ewha Womans University Seoul Hospital, Ewha Womans University School of Medicine, Seoul, Korea.,Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Donghwa Yang
- Department of Pediatrics, National Health Insurance Service Ilsan Hospital, Goyang, Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Dong Seok Kim
- Department of Neurosurgery, Pediatric Neurosurgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
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17
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Tabatabaee S, Bahrami F, Janahmadi M. The Critical Modulatory Role of Spiny Stellate Cells in Seizure Onset Based on Dynamic Analysis of a Neural Mass Model. Front Neurosci 2022; 15:743720. [PMID: 35002598 PMCID: PMC8739215 DOI: 10.3389/fnins.2021.743720] [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: 07/19/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Growing evidence suggests that excitatory neurons in the brain play a significant role in seizure generation. Nonetheless, spiny stellate cells are cortical excitatory non-pyramidal neurons in the brain, whose basic role in seizure occurrence is not well understood. In the present research, we study the critical role of spiny stellate cells or the excitatory interneurons (EI), for the first time, in epileptic seizure generation using an extended neural mass model inspired by a thalamocortical model originally introduced by another research group. Applying bifurcation analysis on this modified model, we investigated the rich dynamics corresponding to the epileptic seizure onset and transition between interictal and ictal states caused by EI connectivity to other cell types. Our results indicate that the transition between interictal and ictal states (preictal signal) corresponds to a supercritical Hopf bifurcation, and thus, the extended model suggests that before seizure onset, the amplitude and frequency of neural activities gradually increase. Moreover, we showed that (1) the altered function of GABAergic and glutamatergic receptors of EI can cause seizure, and (2) the pathway between the thalamic relay nucleus and EI facilitates the transition from interictal to ictal activity by decreasing the preictal period. Thereafter, we considered both sensory and cortical periodic inputs to study model responses to various harmonic stimulations. Bifurcation analysis of the model, in this case, suggests that the initial state of the model might be the main cause for the transition between interictal and ictal states as the stimulus frequency changes. The extended thalamocortical model shows also that the amplitude jump phenomenon and non-linear resonance behavior result from the preictal state of the modified model. These results can be considered as a step forward to a deeper understanding of the mechanisms underlying the transition from normal activities to epileptic activities.
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Affiliation(s)
- Saba Tabatabaee
- Human Motor Control and Computational Neuroscience Laboratory, School of Electrical and Computer Engineering (ECE), College of Engineering, University of Tehran, Tehran, Iran
| | - Fariba Bahrami
- Human Motor Control and Computational Neuroscience Laboratory, School of Electrical and Computer Engineering (ECE), College of Engineering, University of Tehran, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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18
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Lu X, Yang J, Xiang Y. Modeling human neurodevelopmental diseases with brain organoids. CELL REGENERATION (LONDON, ENGLAND) 2022; 11:1. [PMID: 34982276 PMCID: PMC8727646 DOI: 10.1186/s13619-021-00103-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/24/2021] [Indexed: 04/25/2023]
Abstract
Studying the etiology of human neurodevelopmental diseases has long been a challenging task due to the brain's complexity and its limited accessibility. Human pluripotent stem cells (hPSCs)-derived brain organoids are capable of recapitulating various features and functionalities of the human brain, allowing the investigation of intricate pathogenesis of developmental abnormalities. Over the past years, brain organoids have facilitated identifying disease-associated phenotypes and underlying mechanisms for human neurodevelopmental diseases. Integrating with more cutting-edge technologies, particularly gene editing, brain organoids further empower human disease modeling. Here, we review the latest progress in modeling human neurodevelopmental disorders with brain organoids.
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Affiliation(s)
- Xiaoxiang Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jiajie Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yangfei Xiang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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19
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Eapen AV, Fernández-Fernández D, Georgiou J, Bortolotto ZA, Lightman S, Jane DE, Volianskis A, Collingridge GL. Multiple roles of GluN2D-containing NMDA receptors in short-term potentiation and long-term potentiation in mouse hippocampal slices. Neuropharmacology 2021; 201:108833. [PMID: 34637787 PMCID: PMC8607330 DOI: 10.1016/j.neuropharm.2021.108833] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 01/07/2023]
Abstract
The GluN2 subunits of N-methyl-d-aspartate receptors (NMDARs) are key drivers of synaptic plasticity in the brain, where the particular GluN2 composition endows the NMDAR complex with distinct pharmacological and physiological properties. Compared to GluN2A and GluN2B subunits, far less is known about the role of the GluN2D subunit in synaptic plasticity. In this study, we have used a GluN2C/2D selective competitive antagonist, UBP145, in combination with a GluN2D global knockout (GluN2D KO) mouse line to study the contribution of GluN2D-containing NMDARs to short-term potentiation (STP) and long-term potentiation (LTP) in the CA1 region of mouse hippocampal slices. We made several distinct observations: First, GluN2D KO mice have higher levels of LTP compared to wild-type (WT) mice, an effect that was occluded by blockade of GABA receptor-mediated inhibition or by using a strong LTP induction protocol. Second, UBP145 partially inhibited LTP in WT but not GluN2D KO mice. Third, UBP145 inhibited a component of STP, termed STP2, in WT but not GluN2D KO mice. Taken together, these findings suggest an involvement for GluN2D-containing NMDARs in both STP and LTP in mouse hippocampus.
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Affiliation(s)
- Alen V Eapen
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada.
| | - Diego Fernández-Fernández
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - John Georgiou
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
| | - Zuner A Bortolotto
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | | | - David E Jane
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Arturas Volianskis
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Bristol Medical School, University of Bristol, Bristol, UK; Centre for Neuroscience, Surgery and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Graham L Collingridge
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada; TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
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20
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Koene LM, Niggl E, Wallaard I, Proietti-Onori M, Rotaru DC, Elgersma Y. Identifying the temporal electrophysiological and molecular changes that contribute to TSC-associated epileptogenesis. JCI Insight 2021; 6:e150120. [PMID: 34877936 PMCID: PMC8675202 DOI: 10.1172/jci.insight.150120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 10/27/2021] [Indexed: 11/17/2022] Open
Abstract
Tuberous sclerosis complex (TSC), caused by heterozygous mutations in TSC1 or TSC2, frequently results in intractable epilepsy. Here, we made use of an inducible Tsc1-knockout mouse model, allowing us to study electrophysiological and molecular changes of Tsc1-induced epileptogenesis over time. We recorded from pyramidal neurons in the hippocampus and somatosensory cortex (L2/L3) and combined this with an analysis of transcriptome changes during epileptogenesis. Deletion of Tsc1 resulted in hippocampus-specific changes in excitability and adaptation, which emerged before seizure onset and progressed over time. All phenotypes were rescued after early treatment with rapamycin, an mTOR inhibitor. Later in epileptogenesis, we observed a hippocampal increase of excitation-to-inhibition ratio. These cellular changes were accompanied by dramatic transcriptional changes, especially after seizure onset. Most of these changes were rescued upon rapamycin treatment. Of the genes encoding ion channels or belonging to the Gene Ontology term action potential, 27 were differentially expressed just before seizure onset, suggesting a potential driving role in epileptogenesis. Our data highlight the complex changes driving epileptogenesis in TSC, including the changed expression of multiple ion channels. Our study emphasizes inhibition of the TSC/mTOR signaling pathway as a promising therapeutic approach to target epilepsy in patients with TSC.
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21
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Bassetti D, Luhmann HJ, Kirischuk S. Effects of Mutations in TSC Genes on Neurodevelopment and Synaptic Transmission. Int J Mol Sci 2021; 22:7273. [PMID: 34298906 PMCID: PMC8305053 DOI: 10.3390/ijms22147273] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations in TSC1 or TSC2 genes are linked to alterations in neuronal function which ultimately lead to the development of a complex neurological phenotype. Here we review current research on the effects that reduction in TSC1 or TSC2 can produce on the developing neural network. A crucial feature of the disease pathophysiology appears to be an early deviation from typical neurodevelopment, in the form of structural abnormalities. Epileptic seizures are one of the primary early manifestation of the disease in the CNS, followed by intellectual deficits and autism spectrum disorders (ASD). Research using mouse models suggests that morphological brain alterations might arise from the interaction of different cellular types, and hyperexcitability in the early postnatal period might be transient. Moreover, the increased excitation-to-inhibition ratio might represent a transient compensatory adjustment to stabilize the developing network rather than a primary factor for the development of ASD symptoms. The inhomogeneous results suggest region-specificity as well as an evolving picture of functional alterations along development. Furthermore, ASD symptoms and epilepsy might originate from different but potentially overlapping mechanisms, which can explain recent observations obtained in patients. Potential treatment is determined not only by the type of medicament, but also by the time point of treatment.
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Affiliation(s)
- Davide Bassetti
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, 55128 Mainz, Germany; (H.J.L.); (S.K.)
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22
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Marshall GF, Gonzalez-Sulser A, Abbott CM. Modelling epilepsy in the mouse: challenges and solutions. Dis Model Mech 2021; 14:dmm.047449. [PMID: 33619078 PMCID: PMC7938804 DOI: 10.1242/dmm.047449] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In most mouse models of disease, the outward manifestation of a disorder can be measured easily, can be assessed with a trivial test such as hind limb clasping, or can even be observed simply by comparing the gross morphological characteristics of mutant and wild-type littermates. But what if we are trying to model a disorder with a phenotype that appears only sporadically and briefly, like epileptic seizures? The purpose of this Review is to highlight the challenges of modelling epilepsy, in which the most obvious manifestation of the disorder, seizures, occurs only intermittently, possibly very rarely and often at times when the mice are not under direct observation. Over time, researchers have developed a number of ways in which to overcome these challenges, each with their own advantages and disadvantages. In this Review, we describe the genetics of epilepsy and the ways in which genetically altered mouse models have been used. We also discuss the use of induced models in which seizures are brought about by artificial stimulation to the brain of wild-type animals, and conclude with the ways these different approaches could be used to develop a wider range of anti-seizure medications that could benefit larger patient populations. Summary: This Review discusses the challenges of modelling epilepsy in mice, a condition in which the outward manifestation of the disorder appears only sporadically, and reviews possible solutions encompassing both genetic and induced models.
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Affiliation(s)
- Grant F Marshall
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK.,Centre for Discovery Brain Sciences, 1 George Square, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Catherine M Abbott
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK .,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
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23
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Pálfi E, Lévay G, Czurkó A, Lendvai B, Kiss T. Acute blockade of NR2C/D subunit-containing N-methyl-D-aspartate receptors modifies sleep and neural oscillations in mice. J Sleep Res 2020; 30:e13257. [PMID: 33314505 DOI: 10.1111/jsr.13257] [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: 09/11/2020] [Revised: 11/10/2020] [Accepted: 11/25/2020] [Indexed: 11/29/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) play an important role in excitatory neurotransmission and have been associated with psychiatric conditions including schizophrenia and major depressive disorder. NMDARs are composed of two NR1 and two NR2 subunits. The type of NR2 subunit determines electrophysiological and pharmacological properties of the receptor. As the precise role of NR2C/D subunit-containing NMDARs is poorly understood in vivo, we have performed behavioural, quantitative electroencephalographic (qEEG) and polysomnographic analysis following acute pharmacological blockade of these receptor subtypes in adult male CD1 mice. We found that NR2C/D blockade impaired motor coordination and decreased the amount of gross movement. Moreover, EEG power in multiple frequency bands including theta and sigma were found to decrease significantly together with a decrease of theta oscillation frequency. Changes of these qEEG measures were accompanied by a decrease in time spent in slow-wave and rapid eye movement sleep, but an increase of time spent in quiet wakefulness. Furthermore, there was a significant decrease of sleep spindle oscillation density. These findings highlight the importance of NR2C/D-containing NMDARs and take a step towards establishing a link between electrophysiological correlates of psychiatric disorders and underlying synaptic dysfunctions.
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Affiliation(s)
- Emese Pálfi
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - György Lévay
- Pharmacology and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - András Czurkó
- Pharmacology and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Lendvai
- Pharmacology and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Tamás Kiss
- Department of Computational Sciences, Wigner Research Centre for Physics, Budapest, Hungary
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24
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Insights into Potential Targets for Therapeutic Intervention in Epilepsy. Int J Mol Sci 2020; 21:ijms21228573. [PMID: 33202963 PMCID: PMC7697405 DOI: 10.3390/ijms21228573] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.
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25
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Shore AN, Colombo S, Tobin WF, Petri S, Cullen ER, Dominguez S, Bostick CD, Beaumont MA, Williams D, Khodagholy D, Yang M, Lutz CM, Peng Y, Gelinas JN, Goldstein DB, Boland MJ, Frankel WN, Weston MC. Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy. Cell Rep 2020; 33:108303. [PMID: 33113364 PMCID: PMC7712469 DOI: 10.1016/j.celrep.2020.108303] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 08/06/2020] [Accepted: 10/01/2020] [Indexed: 01/07/2023] Open
Abstract
Gain-of-function (GOF) variants in K+ channels cause severe childhood epilepsies, but there are no mechanisms to explain how increased K+ currents lead to network hyperexcitability. Here, we introduce a human Na+-activated K+ (KNa) channel variant (KCNT1-Y796H) into mice and, using a multiplatform approach, find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients. Although the variant increases KNa currents in cortical excitatory and inhibitory neurons, there is an increase in the KNa current across subthreshold voltages only in inhibitory neurons, particularly in those with non-fast-spiking properties, resulting in inhibitory-neuron-specific impairments in excitability and action potential (AP) generation. We further observe evidence of synaptic rewiring, including increases in homotypic synaptic connectivity, accompanied by network hyperexcitability and hypersynchronicity. These findings support inhibitory-neuron-specific mechanisms in mediating the epileptogenic effects of KCNT1 channel GOF, offering cell-type-specific currents and effects as promising targets for therapeutic intervention.
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Affiliation(s)
- Amy N Shore
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA
| | - Sophie Colombo
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - William F Tobin
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA
| | - Sabrina Petri
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - Erin R Cullen
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA
| | - Soledad Dominguez
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | | | - Michael A Beaumont
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Axion BioSystems, Atlanta, GA 30309, USA
| | - Damian Williams
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - Dion Khodagholy
- Department of Electrical Engineering, Columbia University, New York, NY 10032, USA
| | - Mu Yang
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | | | - Yueqing Peng
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Jennifer N Gelinas
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Neurology, Columbia University, New York, NY 10032, USA
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Michael J Boland
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA; Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Matthew C Weston
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA.
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26
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Pons-Bennaceur A, Tsintsadze V, Bui TT, Tsintsadze T, Minlebaev M, Milh M, Scavarda D, Giniatullin R, Giniatullina R, Shityakov S, Wright M, Miller AD, Lozovaya N, Burnashev N. Diadenosine-Polyphosphate Analogue AppCH2ppA Suppresses Seizures by Enhancing Adenosine Signaling in the Cortex. Cereb Cortex 2020; 29:3778-3795. [PMID: 30295710 DOI: 10.1093/cercor/bhy257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 08/15/2018] [Accepted: 09/14/2018] [Indexed: 01/16/2023] Open
Abstract
Epilepsy is a multifactorial disorder associated with neuronal hyperexcitability that affects more than 1% of the human population. It has long been known that adenosine can reduce seizure generation in animal models of epilepsies. However, in addition to various side effects, the instability of adenosine has precluded its use as an anticonvulsant treatment. Here we report that a stable analogue of diadenosine-tetraphosphate: AppCH2ppA effectively suppresses spontaneous epileptiform activity in vitro and in vivo in a Tuberous Sclerosis Complex (TSC) mouse model (Tsc1+/-), and in postsurgery cortical samples from TSC human patients. These effects are mediated by enhanced adenosine signaling in the cortex post local neuronal adenosine release. The released adenosine induces A1 receptor-dependent activation of potassium channels thereby reducing neuronal excitability, temporal summation, and hypersynchronicity. AppCH2ppA does not cause any disturbances of the main vital autonomous functions of Tsc1+/- mice in vivo. Therefore, we propose this compound to be a potent new candidate for adenosine-related treatment strategies to suppress intractable epilepsies.
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Affiliation(s)
- Alexandre Pons-Bennaceur
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Vera Tsintsadze
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France.,Knight Cardiovascular Institute, Oregon Health and Science University, OR, USA
| | - Thi-Thien Bui
- B&A Therapeutics, Ben-Ari Institute of Neuroarcheology, Batiment Beret-Delaage, Zone Luminy Biotech Entreprises, Marseille, Cedex 09, France
| | - Timur Tsintsadze
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Marat Minlebaev
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France.,Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| | - Mathieu Milh
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, Marseille Cedex 5, France
| | - Didier Scavarda
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, Marseille Cedex 5, France
| | - Rashid Giniatullin
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.,A.I. Virtanen Institute for Molecular Sciences, Department of Neurobiology, University of Eastern Finland, Kuopio, Finland
| | - Raisa Giniatullina
- A.I. Virtanen Institute for Molecular Sciences, Department of Neurobiology, University of Eastern Finland, Kuopio, Finland
| | - Sergey Shityakov
- Department of Anaesthesia and Critical Care, University of Würzburg, Josef-Schneider-Street 2, Würzburg, Germany
| | - Michael Wright
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, Waterloo Campus, 150 Stamford Street, London, UK
| | - Andrew D Miller
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, Waterloo Campus, 150 Stamford Street, London, UK.,Veterinary Research Institute, Hudcova 296/70, Brno, Czech Republic.,KP Therapeutics Ltd, 86 Deansgate, Manchester, UK
| | - Natalia Lozovaya
- B&A Therapeutics, Ben-Ari Institute of Neuroarcheology, Batiment Beret-Delaage, Zone Luminy Biotech Entreprises, Marseille, Cedex 09, France
| | - Nail Burnashev
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
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27
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Ghatak S, Talantova M, McKercher SR, Lipton SA. Novel Therapeutic Approach for Excitatory/Inhibitory Imbalance in Neurodevelopmental and Neurodegenerative Diseases. Annu Rev Pharmacol Toxicol 2020; 61:701-721. [PMID: 32997602 DOI: 10.1146/annurev-pharmtox-032320-015420] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Excitatory/inhibitory (E/I) balance, defined as the balance between excitation and inhibition of synaptic activity in a neuronal network, accounts in part for the normal functioning of the brain, controlling, for example, normal spike rate. In many pathological conditions, this fine balance is perturbed, leading to excessive or diminished excitation relative to inhibition, termed E/I imbalance, reflected in network dysfunction. E/I imbalance has emerged as a contributor to neurological disorders that occur particularly at the extremes of life, including autism spectrum disorder and Alzheimer's disease, pointing to the vulnerability of neuronal networks at these critical life stages. Hence, it is important to develop approaches to rebalance neural networks. In this review, we describe emerging therapies that can normalize the E/I ratio or the underlying abnormality that contributes to the imbalance in electrical activity, thus improving neurological function in these maladies.
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Affiliation(s)
- Swagata Ghatak
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Maria Talantova
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Scott R McKercher
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA;
| | - Stuart A Lipton
- Department of Molecular Medicine and Neuroscience Translational Center, The Scripps Research Institute, La Jolla, California 92037, USA; .,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
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28
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Radaic A, Martins-de-Souza D. The state of the art of nanopsychiatry for schizophrenia diagnostics and treatment. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 28:102222. [DOI: 10.1016/j.nano.2020.102222] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/18/2020] [Accepted: 05/02/2020] [Indexed: 02/07/2023]
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29
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Velíšek L, Velíšková J. Modeling epileptic spasms during infancy: Are we heading for the treatment yet? Pharmacol Ther 2020; 212:107578. [PMID: 32417271 PMCID: PMC7299814 DOI: 10.1016/j.pharmthera.2020.107578] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 05/07/2020] [Indexed: 12/22/2022]
Abstract
Infantile spasms (IS or epileptic spasms during infancy) were first described by Dr. William James West (aka West syndrome) in his own son in 1841. While rare by definition (occurring in 1 per 3200-3400 live births), IS represent a major social and treatment burden. The etiology of IS varies - there are many (>200) different known pathologies resulting in IS and still in about one third of cases there is no obvious reason. With the advancement of genetic analysis, role of certain genes (such as ARX or CDKL5 and others) in IS appears to be important. Current treatment strategies with incomplete efficacy and serious potential adverse effects include adrenocorticotropin (ACTH), corticosteroids (prednisone, prednisolone) and vigabatrin, more recently also a combination of hormones and vigabatrin. Second line treatments include pyridoxine (vitamin B6) and ketogenic diet. Additional treatment approaches use rapamycin, cannabidiol, valproic acid and other anti-seizure medications. Efficacy of these second line medications is variable but usually inferior to hormonal treatments and vigabatrin. Thus, new and effective models of this devastating condition are required for the search of additional treatment options as well as for better understanding the mechanisms of IS. Currently, eight models of IS are reviewed along with the ideas and mechanisms behind these models, drugs tested using the models and their efficacy and usefulness. Etiological variety of IS is somewhat reflected in the variety of the models. However, it seems that for finding precise personalized approaches, this variety is necessary as there is no "one-size-fits-all" approach possible for both IS in particular and epilepsy in general.
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Affiliation(s)
- Libor Velíšek
- Departments of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA; Departments of Pediatrics, New York Medical College, Valhalla, NY, USA; Departments of Neurology, New York Medical College, Valhalla, NY, USA.
| | - Jana Velíšková
- Departments of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA; Departments of Neurology, New York Medical College, Valhalla, NY, USA; Departments of Obstetrics & Gynecology, New York Medical College, Valhalla, NY, USA
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30
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Bassetti D, Lombardi A, Kirischuk S, Luhmann HJ. Haploinsufficiency of Tsc2 Leads to Hyperexcitability of Medial Prefrontal Cortex via Weakening of Tonic GABAB Receptor-mediated Inhibition. Cereb Cortex 2020; 30:6313-6324. [PMID: 32705128 DOI: 10.1093/cercor/bhaa187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 12/30/2022] Open
Abstract
Loss-of-function mutation in one of the tumor suppressor genes TSC1 or TSC2 is associated with several neurological and psychiatric diseases, including autism spectrum disorders (ASDs). As an imbalance between excitatory and inhibitory neurotransmission, E/I ratio is believed to contribute to the development of these disorders, we investigated synaptic transmission during the first postnatal month using the Tsc2+/- mouse model. Electrophysiological recordings were performed in acute brain slices of medial prefrontal cortex. E/I ratio at postnatal day (P) 15-19 is increased in Tsc2+/- mice as compared with wildtype (WT). At P25-30, facilitated GABAergic transmission reduces E/I ratio to the WT level, but weakening of tonic GABAB receptor (GABABR)-mediated inhibition in Tsc2+/- mice leads to hyperexcitability both at single cell and neuronal network level. Short (1 h) preincubation of P25-30 Tsc2+/- slices with baclofen restores the GABABR-mediated inhibition and reduces network excitability. Interestingly, the same treatment at P15-19 leads to weakening of GABABR-mediated inhibition. We hypothesize that a dysfunction of tonic GABABR-mediated inhibition might contribute to the development of ASD symptoms and suggest that GABABR activation within an appropriate time window may be considered as a therapeutic target in ASD.
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Affiliation(s)
- Davide Bassetti
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz D-55128, Germany
| | - Aniello Lombardi
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz D-55128, Germany
| | - Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz D-55128, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz D-55128, Germany
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31
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Feliciano DM. The Neurodevelopmental Pathogenesis of Tuberous Sclerosis Complex (TSC). Front Neuroanat 2020; 14:39. [PMID: 32765227 PMCID: PMC7381175 DOI: 10.3389/fnana.2020.00039] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a model disorder for understanding brain development because the genes that cause TSC are known, many downstream molecular pathways have been identified, and the resulting perturbations of cellular events are established. TSC, therefore, provides an intellectual framework to understand the molecular and biochemical pathways that orchestrate normal brain development. The TSC1 and TSC2 genes encode Hamartin and Tuberin which form a GTPase activating protein (GAP) complex. Inactivating mutations in TSC genes (TSC1/TSC2) cause sustained Ras homologue enriched in brain (RHEB) activation of the mammalian isoform of the target of rapamycin complex 1 (mTORC1). TOR is a protein kinase that regulates cell size in many organisms throughout nature. mTORC1 inhibits catabolic processes including autophagy and activates anabolic processes including mRNA translation. mTORC1 regulation is achieved through two main upstream mechanisms. The first mechanism is regulation by growth factor signaling. The second mechanism is regulation by amino acids. Gene mutations that cause too much or too little mTORC1 activity lead to a spectrum of neuroanatomical changes ranging from altered brain size (micro and macrocephaly) to cortical malformations to Type I neoplasias. Because somatic mutations often underlie these changes, the timing, and location of mutation results in focal brain malformations. These mutations, therefore, provide gain-of-function and loss-of-function changes that are a powerful tool to assess the events that have gone awry during development and to determine their functional physiological consequences. Knowledge about the TSC-mTORC1 pathway has allowed scientists to predict which upstream and downstream mutations should cause commensurate neuroanatomical changes. Indeed, many of these predictions have now been clinically validated. A description of clinical imaging and histochemical findings is provided in relation to laboratory models of TSC that will allow the reader to appreciate how human pathology can provide an understanding of the fundamental mechanisms of development.
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Affiliation(s)
- David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, United States
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32
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van Andel DM, Sprengers JJ, Oranje B, Scheepers FE, Jansen FE, Bruining H. Effects of bumetanide on neurodevelopmental impairments in patients with tuberous sclerosis complex: an open-label pilot study. Mol Autism 2020; 11:30. [PMID: 32381101 PMCID: PMC7204231 DOI: 10.1186/s13229-020-00335-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 04/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is an autosomal dominant disease that affects multiple organs including the brain. TSC is strongly associated with broad neurodevelopmental disorders, including autism spectrum disorder symptomatology. Preclinical TSC studies have indicated altered neuronal chloride homeostasis affecting the polarity of γ-aminobutyric acid (GABA) ergic transmission as a potential treatment target. Bumetanide, a selective NKCC1 chloride importer antagonist, may attenuate depolarizing GABA action, and in that way reduce disease burden. In this open-label pilot study, we tested the effect of bumetanide on a variety of neurophysiological, cognitive, and behavioral measures in children with TSC. METHODS Participants were treated with bumetanide (2dd 0.5-1.0 mg) for 13 weeks in an open-label trial. The Aberrant Behavior Checklist-Irritability (ABC-I) subscale was chosen as the primary endpoint. Secondary endpoints included other behavioral questionnaires in addition to event-related potentials (ERP) and neuropsychological tests if tolerated. Additionally, the treatment effect on seizure frequency and quality of life was assessed. Endpoint data were collected at baseline, after 91 days of treatment and after a 28-day wash-out period. RESULTS Fifteen patients (8-21-years old) with TSC were included of which 13 patients completed the study. Treatment was well-tolerated with only expected adverse events due to the diuretic effects of bumetanide. Irritable behavior (ABC-I) showed significant improvement after treatment in 11 out of 13 patients (t(12) = 4.41, p = .001, d = .773). A favorable effect was also found for social behavior (Social Responsiveness Scale) (t(11) = 4.01, p = .002, d = .549) and hyperactive behavior (ABC-hyperactivity subscale) (t(12) = 3.65, p = .003, d = .686). Moreover, patients rated their own health-related quality of life higher after treatment. At baseline, TSC patients showed several atypical ERPs versus typically developing peers of which prepulse inhibition was significantly decreased in the TSC group. Neuropsychological measurements showed no change and bumetanide had no effect on seizure frequency. LIMITATIONS The sample size and open-label design of this pilot study warrant caution when interpreting outcome measures. CONCLUSIONS Bumetanide treatment is a potential treatment to alleviate the behavioral burden and quality of life associated with TSC. More elaborate trials are needed to determine the application and effect size of bumetanide for the TSC population. Trial registration EU Clinical Trial Register, EudraCT 2016-002408-13 (www.clinicaltrialsregister.eu/ctr-search/trial/2016-002408-13/NL). Registered 25 July 2016.
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Affiliation(s)
- Dorinde M van Andel
- Department of Psychiatry, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Jan J Sprengers
- Department of Psychiatry, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Bob Oranje
- Department of Psychiatry, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Floortje E Scheepers
- Department of Psychiatry, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Floor E Jansen
- Department of Pediatric Neurology, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Hilgo Bruining
- Department of Psychiatry, Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.,Department of Child and Adolescent Psychiatry, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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33
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Auvin S, Avbersek A, Bast T, Chiron C, Guerrini R, Kaminski RM, Lagae L, Muglia P, Cross JH. Drug Development for Rare Paediatric Epilepsies: Current State and Future Directions. Drugs 2020; 79:1917-1935. [PMID: 31734883 DOI: 10.1007/s40265-019-01223-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rare diseases provide a challenge in the evaluation of new therapies. However, orphan drug development is of increasing interest because of the legislation enabling facilitated support by regulatory agencies through scientific advice, and the protection of the molecules with orphan designation. In the landscape of the rare epilepsies, very few syndromes, namely Dravet syndrome, Lennox-Gastaut syndrome and West syndrome, have been subject to orphan drug development. Despite orphan designations for rare epilepsies having dramatically increased in the past 10 years, the number of approved drugs remains limited and restricted to a handful of epilepsy syndromes. In this paper, we describe the current state of orphan drug development for rare epilepsies. We identified a large number of compounds currently under investigation, but mostly in the same rare epilepsy syndromes as in the past. A rationale for further development in rare epilepsies could be based on the match between the drug mechanisms of action and the knowledge of the causative gene mutation or by evidence from animal models. In case of the absence of strong pathophysiological hypotheses, exploratory/basket clinical studies could be helpful to identify a subpopulation that may benefit from the new drug. We provide some suggestions for future improvements in orphan drug development such as promoting paediatric drug investigations, better evaluation of the incidence and the prevalence, together with the natural history data, and the development of new primary outcomes.
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Affiliation(s)
- Stéphane Auvin
- PROTECT, INSERM U1141, Université de Paris, Paris, France. .,Service de Neurologie Pédiatrique, AP-HP, Hôpital Universitaire Robert-Debré, 48, Boulevard Sérurier, 75935, Paris Cedex 19, France.
| | | | - Thomas Bast
- The Kork Epilepsy Center, Kehl-Kork, Germany.,Medical Faculty of the University of Freiburg, Freiburg, Germany
| | - Catherine Chiron
- PROTECT, INSERM U1141, Université de Paris, Paris, France.,Service de Neurologie Pédiatrique, AP-HP, Hôpital Necker-Enfanst Malades, Paris, France
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Anna Meyer-University of Florence, Florence, Italy
| | - Rafal M Kaminski
- UCB Pharma, Braine-l'Alleud, Belgium.,Roche Pharma Research and Early Development (pRED), Roche Innovation Center, Basel, Switzerland
| | - Lieven Lagae
- Department Development and Regeneration, Section Paediatric Neurology, University Hospitals, University of Leuven, Leuven, Belgium
| | | | - J Helen Cross
- UCL NIHR BRC Great Ormond Street Institute of Child Health, London, UK
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34
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Rensing N, Johnson KJ, Foutz TJ, Friedman JL, Galindo R, Wong M. Early developmental electroencephalography abnormalities, neonatal seizures, and induced spasms in a mouse model of tuberous sclerosis complex. Epilepsia 2020; 61:879-891. [PMID: 32274803 DOI: 10.1111/epi.16495] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Tuberous sclerosis complex (TSC) is one of the most common genetic causes of epilepsy. Seizures in TSC typically first present in infancy or early childhood, including focal seizures and infantile spasms. Infantile spasms in TSC are particularly characteristic in its strong responsiveness to vigabatrin. Although a number of mouse models of epilepsy in TSC have been described, there are very limited electroencephalographic (EEG) or seizure data during the preweanling neonatal and infantile-equivalent mouse periods. Tsc1GFAP CKO mice are a well-characterized mouse model of epilepsy in TSC, but whether these mice have seizures during early development has not been documented. The objective of this study was to determine whether preweanling Tsc1GFAP CKO mice have developmental EEG abnormalities or seizures, including spasms. METHODS Longitudinal video-EEG and electromyographic recordings were performed serially on Tsc1GFAP CKO and control mice from postnatal days 9-21 and analyzed for EEG background abnormalities, sleep-wake vigilance states, and spontaneous seizures. Spasms were also induced with varying doses of N-methyl-D-aspartate (NMDA). RESULTS The interictal EEG of Tsc1GFAP CKO mice had excessive discontinuity and slowing, suggesting a delayed developmental progression compared with control mice. Tsc1GFAP CKO mice also had increased vigilance state transitions and fragmentation. Tsc1GFAP CKO mice had spontaneous focal seizures in the early neonatal period and a reduced threshold for NMDA-induced spasms, but no spontaneous spasms were observed. SIGNIFICANCE Neonatal Tsc1GFAP CKO mice recapitulate early developmental aspects of EEG abnormalities, focal seizures, and an increased propensity for spasms. This mouse model may be useful for early mechanistic and therapeutic studies of epileptogenesis in TSC.
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Affiliation(s)
- Nicholas Rensing
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Kevin J Johnson
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Thomas J Foutz
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Joseph L Friedman
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Rafael Galindo
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
| | - Michael Wong
- Department of Neurology and Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, Missouri
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35
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Parente DJ, Morris SM, McKinstry RC, Brandt T, Gabau E, Ruiz A, Shinawi M. Sorting nexin 27 (SNX27) variants associated with seizures, developmental delay, behavioral disturbance, and subcortical brain abnormalities. Clin Genet 2019; 97:437-446. [PMID: 31721175 DOI: 10.1111/cge.13675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 11/27/2022]
Abstract
Sorting nexin 27 (SNX27) influences the composition of the cellular membrane via regulation of selective endosomal recycling. Molecular analysis indicates that SNX27 regulates numerous cellular processes through promiscuous interactions with its receptor cargos. SNX27 deficient (Snx27 -/- ) mice exhibit reduced embryonic survival, marked postnatal growth restriction and lethality. Haploinsufficient mice (Snx27 +/- ) show a less severe phenotype, with deficits in learning, memory, synaptic transmission and neuronal plasticity. One family previously reported with a homozygous SNX27 frameshift variant (c.515_516del;p.His172Argfs*6), exhibited infantile intractable myoclonic epilepsy, axial hypotonia, startle-like movements, cardiac septal defects, global developmental delay, failure to thrive, recurrent chest infections, persistent hypoxemia and early death secondary to respiratory failure. Here, we report two additional patients with compound heterozygous SNX27 variants, that are predicted to be damaging: (a) c.510C>G;p.Tyr170* and c.1295G>A;p.Cys432Tyr, and (b) c.782dupT;p.Leu262Profs*6 and c.989G>A;p.Arg330His. They exhibit global developmental delay, behavioral disturbance, epilepsy, some dysmorphic features and subcortical white matter abnormalities. In addition, possible connective tissue involvement was noted. Epilepsy, developmental delays and subcortical white matter abnormalities appear to be core features of SNX27-related disorders. We correlate the observed phenotype with available in vitro, in vivo and proteomic data and suggest additional possible molecular mediators of SNX27-related pathology.
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Affiliation(s)
- Daniel J Parente
- Department of Family Medicine, University of Kansas Medical Center, Kansas City, Kansas
| | - Stephanie M Morris
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - Robert C McKinstry
- Pediatric Radiology and Pediatric Neuroradiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | | | - Elisabeth Gabau
- Paediatric Unit, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Anna Ruiz
- Genetics Laboratory, UDIAT-Centre Diagnòstic, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
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Ding Y, Wang L, Huo Y, Sun Y, Wang L, Gao Z, Sun Y. Roles of GluN2C in cerebral ischemia: GluN2C expressed in different cell types plays different role in ischemic damage. J Neurosci Res 2019; 98:1188-1197. [DOI: 10.1002/jnr.24574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 11/05/2019] [Accepted: 11/26/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Yue Ding
- Shijiazhuang Vocational College of Technology and Information Shijiazhuang PR China
| | - Le Wang
- Department of Pharmaceutical Engineering Hebei Chemical & Pharmaceutical College Shijiazhuang China
| | - Yuexiang Huo
- Department of Pharmacy Hebei University of Science and Technology Shijiazhuang China
| | - Yanping Sun
- State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug Shijiazhuang China
| | - Long Wang
- Department of Family and Consumer Sciences California State University Long Beach CA USA
| | - Zibin Gao
- Department of Pharmacy Hebei University of Science and Technology Shijiazhuang China
- State Key Laboratory Breeding Base—Hebei Province Key Laboratory of Molecular Chemistry for Drug Shijiazhuang China
| | - Yongjun Sun
- Department of Pharmacy Hebei University of Science and Technology Shijiazhuang China
- Hebei Research Center of Pharmaceutical and Chemical Engineering Hebei University of Science and Technology Shijiazhuang China
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37
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Biallelic Mutations in TSC2 Lead to Abnormalities Associated with Cortical Tubers in Human iPSC-Derived Neurons. J Neurosci 2019; 39:9294-9305. [PMID: 31591157 DOI: 10.1523/jneurosci.0642-19.2019] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/02/2019] [Accepted: 08/30/2019] [Indexed: 12/18/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder caused by mutations in TSC1 or TSC2 Patients frequently have epilepsy, autism spectrum disorder, and/or intellectual disability, as well as other systemic manifestations. In this study, we differentiated human induced pluripotent stem cells (iPSCs) from a female patient with TSC with one or two mutations in TSC2 into neurons using induced expression of NGN2 to examine neuronal dysregulation associated with the neurological symptoms in TSC. Using this method, neuronal differentiation was comparable between the three genotypes of iPSCs. We observed that TSC2 +/- neurons show mTOR complex 1 (mTORC1) hyperactivation and associated increased cell body size and process outgrowth, as well as exacerbation of the abnormalities by loss of the second allele of TSC2 in TSC2 -/- neurons. Interestingly, iPSC-derived neurons with either a single or biallelic mutation in TSC2 demonstrated hypersynchrony and downregulation of FMRP targets. However, only neurons with biallelic mutations of TSC2 demonstrated hyperactivity and transcriptional dysregulation observed in cortical tubers. These data demonstrate that loss of one allele of TSC2 is sufficient to cause some morphological and physiological changes in human neurons but that biallelic mutations in TSC2 are necessary to induce gene expression dysregulation present in cortical tubers. Finally, we found that treatment of iPSC-derived neurons with rapamycin reduced neuronal activity and partially reversed gene expression abnormalities, demonstrating that mTOR dysregulation contributes to both phenotypes. Therefore, biallelic mutations in TSC2 and associated molecular dysfunction, including mTOR hyperactivation, may play a role in the development of cortical tubers.SIGNIFICANCE STATEMENT In this study, we examined neurons derived from induced pluripotent stem cells with two, one, or no functional TSC2 (tuberous sclerosis complex 2) alleles and found that loss of one or both alleles of TSC2 results in mTORC1 hyperactivation and specific neuronal abnormalities. However, only biallelic mutations in TSC2 resulted in elevated neuronal activity and upregulation of cell adhesion genes that is also observed in cortical tubers. These data suggest that loss of heterozygosity of TSC1 or TSC2 may play an important role in the development of cortical tubers, and potentially epilepsy, in patients with TSC.
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38
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Gataullina S, Bienvenu T, Nabbout R, Huberfeld G, Dulac O. Gene mutations in paediatric epilepsies cause NMDA-pathy, and phasic and tonic GABA-pathy. Dev Med Child Neurol 2019; 61:891-898. [PMID: 30680721 DOI: 10.1111/dmcn.14152] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/20/2018] [Indexed: 12/28/2022]
Abstract
The aim of this study was to disentangle mechanisms of epileptogenesis in monogenic epilepsies in children. We reviewed paediatric monogenic epilepsies excluding brain malformation or an inborn error of metabolism, but including the gene function whether there is loss-of-function or gain-of-function, age at gene expression when available, and associated epilepsy syndrome. Genes for which at least five patients with similar epilepsy phenotype had been reported were selected. Three mechanisms are shared by most monogenic epilepsies: (1) excess of N-methyl-d-aspartate (NMDA) transmission activation (NMDA-pathies); (2) abnormal gamma-aminobutyric acid (GABA) transmission with reduced inhibition (phasic GABA-pathies); and (3) tonic activation of extrasynaptic GABAA receptors by extracellular GABA (tonic GABA-pathies). NMDA-pathies comprise early epileptic encephalopathy with suppression-burst, neonatal/infantile benign seizures, West and Lennox-Gastaut syndromes, and encephalopathy with continuous spike waves in slow sleep, thus brief seizures with major interictal spiking. Phasic GABA-pathies comprise mostly generalized epilepsy with febrile seizures plus and Dravet syndrome, thus long-lasting seizures with mild interictal spiking. Tonic GABA-pathies cause epilepsy with myoclonic-atonic seizures and Angelman syndrome, thus major high-amplitude slow-wave activity. This pathophysiological approach to monogenic epilepsies provides diagnostic clues and helps to guide treatment strategy. WHAT THIS PAPER ADDS: In paediatric monogenic epilepsies, electroclinical patterns point to three main mechanisms: NMDA-pathies, and phasic and tonic GABA-pathies. Antiepileptic treatment choice could be guided by each of these mechanisms.
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Affiliation(s)
- Svetlana Gataullina
- Service d' Explorations Fonctionnelles multidisciplinaires Hôpital Antoine Béclère, AP-HP, Clamart, France.,Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,Service de Pédiatrie, Centre Hospitalier Intercommunal, Montreuil, France
| | - Thierry Bienvenu
- Biochemistry and Molecular Genetics Laboratory, Hôpital Cochin, Paris Centre University Group, Paris, France.,Institut Cochin, Inserm U1016, Paris Descartes University, Paris, France
| | - Rima Nabbout
- Centre de Reference Épilepsies Rares, Necker-Enfants Malades Hospital, Paris, France
| | - Gilles Huberfeld
- Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,Clinical Neurophysiology Department, Pitié-Salpêtrière Hospital, Sorbone University, AP-HP, Paris, France.,Neuroglial Interactions in Cerebral Pathophysiology, Center for Interdisciplinary Research in Biology, Collège de France, CNR UMR 7421, Inserm U1050, Labex MemolifePSL Research University, Paris, France
| | - Olivier Dulac
- Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,AdPueriVitam, Antony, France
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Salmi M, Del Gallo F, Minlebaev M, Zakharov A, Pauly V, Perron P, Pons‐Bennaceur A, Corby‐Pellegrino S, Aniksztejn L, Lenck‐Santini P, Epsztein J, Khazipov R, Burnashev N, Bertini G, Szepetowski P. Impaired vocal communication, sleep‐related discharges, and transient alteration of slow‐wave sleep in developing mice lacking the GluN2A subunit of
N
‐methyl‐
d
‐aspartate receptors. Epilepsia 2019; 60:1424-1437. [DOI: 10.1111/epi.16060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/13/2019] [Accepted: 05/13/2019] [Indexed: 02/04/2023]
Affiliation(s)
- Manal Salmi
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Federico Del Gallo
- Department of Neurosciences, Biomedicine, and Movement Sciences University of Verona Verona Italy
| | - Marat Minlebaev
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
- Laboratory of Neurobiology Kazan Federal University Kazan Russia
| | - Andrey Zakharov
- Laboratory of Neurobiology Kazan Federal University Kazan Russia
| | - Vanessa Pauly
- Public Health Laboratory, Recognized Team (EA) 3279 Associate Center for Drug Dependency and Addictovigilance Faculty of Medicine Aix‐Marseille University Marseille France
| | - Pauline Perron
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Alexandre Pons‐Bennaceur
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Séverine Corby‐Pellegrino
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Laurent Aniksztejn
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Pierre‐Pascal Lenck‐Santini
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Jérôme Epsztein
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Rustem Khazipov
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
- Laboratory of Neurobiology Kazan Federal University Kazan Russia
| | - Nail Burnashev
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
| | - Giuseppe Bertini
- Department of Neurosciences, Biomedicine, and Movement Sciences University of Verona Verona Italy
| | - Pierre Szepetowski
- National Institute of Health and Medical Research INSERM Joint Research Unit UMR 1249Mediterranean Institute of Neurobiology INMEDAix‐Marseille University Marseille France
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FAN M, DONG S, ZOU X, ZHENG B, HUANG Y, WANG J, ZENG L. [Correlation of phosphorylated S6 protein expression in blood and brain tissue in mice and rats with kainic acid-induced seizure]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2019; 48:303-309. [PMID: 31496163 PMCID: PMC8800752 DOI: 10.3785/j.issn.1008-9292.2019.06.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/15/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVE To determine the correlation of phosphorylated ribosomal S6 protein (P-S6) content in blood and brain tissue in mice and rats with seizure. METHODS Seizure models were induced by intraperitoric injection of kainic acid (KA) in C57BL/mice and SD rats. Flow cytometry was used to detect the content of P-S6 in blood; Western blot was used to detect the expression of P-S6 in brain tissues. The correlation between P-S6 expression in blood and in brain tissue was examine by Pearson analysis, and the correlation between P-S6 expression in blood and the severity of seizure was also observed. RESULTS Western blotting analysis showed that the expression of P-S6 was significantly increased in peripheral blood and brain tissue in mice 1 h after KA-induced seizure,and the expression levels increased to (1.49±0.45) times (P<0.05) and (2.55±0.66) times (P <0.01) of the control group, respectively. Flow cytometry showed that the positive percentage and average fluorescence intensity of P-S6 in the blood of mice increased significantly 1 h after KA-induced seizures (P<0.01), which was consistent with the expression of P-S6 in brain tissue (r=0.8474, P<0.01). Flow cytometry showed that the average fluorescence intensity of P-S6 in blood increased from 14.89±9.75 to 52.35±21.72 (P<0.01) in rats with seizure, which was consistent with the change of P-S6 in brain tissue (r=0.9385, P<0.01). Rats with higher levels of seizure were of higher levels of P-S6 in peripheral blood. CONCLUSIONS Consistent correlation of P-S6 expression is demonstrated in peripheral blood and in brain tissue after KA-induced seizure, suggesting that the expression of P-S6 in blood can accurately reflect the changes of mTOR signaling pathway in brain tissue.
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Affiliation(s)
| | | | | | | | | | - Jianda WANG
- 王健达(1988-), 男, 硕士, 住院医师, 主要从事神经内科学研究; E-mail:
;
https://orcid.org/0000-0001-7148-3183
| | - Linghui ZENG
- 曾玲晖(1972-), 女, 博士, 教授, 博士生导师, 主要从事神经药理学研究; E-mail:
;
https://orcid.org/0000-0002-5924-4419
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Hanson E, Armbruster M, Lau LA, Sommer ME, Klaft ZJ, Swanger SA, Traynelis SF, Moss SJ, Noubary F, Chadchankar J, Dulla CG. Tonic Activation of GluN2C/GluN2D-Containing NMDA Receptors by Ambient Glutamate Facilitates Cortical Interneuron Maturation. J Neurosci 2019; 39:3611-3626. [PMID: 30846615 PMCID: PMC6510335 DOI: 10.1523/jneurosci.1392-18.2019] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 01/29/2019] [Accepted: 02/26/2019] [Indexed: 02/03/2023] Open
Abstract
Developing cortical GABAergic interneurons rely on genetic programs, neuronal activity, and environmental cues to construct inhibitory circuits during early postnatal development. Disruption of these events can cause long-term changes in cortical inhibition and may be involved in neurological disorders associated with inhibitory circuit dysfunction. We hypothesized that tonic glutamate signaling in the neonatal cortex contributes to, and is necessary for, the maturation of cortical interneurons. To test this hypothesis, we used mice of both sexes to quantify extracellular glutamate concentrations in the cortex during development, measure ambient glutamate-mediated activation of developing cortical interneurons, and manipulate tonic glutamate signaling using subtype-specific NMDA receptor antagonists in vitro and in vivo We report that ambient glutamate levels are high (≈100 nm) in the neonatal cortex and decrease (to ≈50 nm) during the first weeks of life, coincident with increases in astrocytic glutamate uptake. Consistent with elevated ambient glutamate, putative parvalbumin-positive interneurons in the cortex (identified using G42:GAD1-eGFP reporter mice) exhibit a transient, tonic NMDA current at the end of the first postnatal week. GluN2C/GluN2D-containing NMDA receptors mediate the majority of this current and contribute to the resting membrane potential and intrinsic properties of developing putative parvalbumin interneurons. Pharmacological blockade of GluN2C/GluN2D-containing NMDA receptors in vivo during the period of tonic interneuron activation, but not later, leads to lasting decreases in interneuron morphological complexity and causes deficits in cortical inhibition later in life. These results demonstrate that dynamic ambient glutamate signaling contributes to cortical interneuron maturation via tonic activation of GluN2C/GluN2D-containing NMDA receptors.SIGNIFICANCE STATEMENT Inhibitory GABAergic interneurons make up 20% of cortical neurons and are critical to controlling cortical network activity. Dysfunction of cortical inhibition is associated with multiple neurological disorders, including epilepsy. Establishing inhibitory cortical networks requires in utero proliferation, differentiation, and migration of immature GABAergic interneurons, and subsequent postnatal morphological maturation and circuit integration. Here, we demonstrate that ambient glutamate provides tonic activation of immature, putative parvalbumin-positive GABAergic interneurons in the neonatal cortex via high-affinity NMDA receptors. When this activation is blocked, GABAergic interneuron maturation is disrupted, and cortical networks exhibit lasting abnormal hyperexcitability. We conclude that temporally precise activation of developing cortical interneurons by ambient glutamate is critically important for establishing normal cortical inhibition.
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Affiliation(s)
- Elizabeth Hanson
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Neuroscience Program, Tufts Sackler School of Biomedical Sciences, Boston, Massachusetts 02111
| | - Moritz Armbruster
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Lauren A Lau
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- Neuroscience Program, Tufts Sackler School of Biomedical Sciences, Boston, Massachusetts 02111
| | - Mary E Sommer
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Zin-Juan Klaft
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Sharon A Swanger
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, and
| | - Farzad Noubary
- Department of Health Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115
| | - Jayashree Chadchankar
- AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, and
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111,
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Salussolia CL, Klonowska K, Kwiatkowski DJ, Sahin M. Genetic Etiologies, Diagnosis, and Treatment of Tuberous Sclerosis Complex. Annu Rev Genomics Hum Genet 2019; 20:217-240. [PMID: 31018109 DOI: 10.1146/annurev-genom-083118-015354] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects multiple organ systems due to an inactivating variant in either TSC1 or TSC2, resulting in the hyperactivation of the mechanistic target of rapamycin (mTOR) pathway. Dysregulated mTOR signaling results in increased cell growth and proliferation. Clinically, TSC patients exhibit great phenotypic variability, but the neurologic and neuropsychiatric manifestations of the disease have the greatest morbidity and mortality. TSC-associated epilepsy occurs in nearly all patients and is often difficult to treat because it is refractory to multiple antiseizure medications. The advent of mTOR inhibitors offers great promise in the treatment of TSC-associated epilepsy and other neurodevelopmental manifestations of the disease; however, the optimal timing of therapeutic intervention is not yet fully understood.
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Affiliation(s)
- Catherine L Salussolia
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Katarzyna Klonowska
- Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - David J Kwiatkowski
- Division of Pulmonary and Critical Care Medicine and Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA;
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Su T, Lu Y, Geng Y, Lu W, Chen Y. How could N-Methyl-D-Aspartate Receptor Antagonists Lead to Excitation Instead of Inhibition? BRAIN SCIENCE ADVANCES 2019. [DOI: 10.26599/bsa.2018.2018.9050009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are a family of ionotropic glutamate receptors mainly known to mediate excitatory synaptic transmission and plasticity. Interestingly, low-dose NMDAR antagonists lead to increased, instead of decreased, functional connectivity; and they could cause schizophrenia- and/or antidepressant-like behavior in both humans and rodents. In addition, human genetic evidences indicate that NMDAR loss of function mutations underlie certain forms of epilepsy, a disease featured with abnormal brain hyperactivity. Together, they all suggest that under certain conditions, NMDAR activation actually lead to inhibition, but not excitation, of the global neuronal network. Apparently, these phenomena are rather counterintuitive to the receptor's basic role in mediating excitatory synaptic transmission. How could it happen? Recently, this has become a crucial question in order to fully understand the complexity of NMDAR function, particularly in disease. Over the past decades, different theories have been proposed to address this question. These include theories of “NMDARs on inhibitory neurons are more sensitive to antagonism”, or “basal NMDAR activity actually inhibits excitatory synapse”, etc. Our review summarizes these efforts, and also provides an introduction of NMDARs, inhibitory neurons, and their relationships with the related diseases. Advances in the development of novel NMDAR pharmacological tools, particularly positive allosteric modulators, are also included to provide insights into potential intervention strategies.
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Affiliation(s)
- Tonghui Su
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Lu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Geng
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Lu
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yelin Chen
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Represa A. Why Malformations of Cortical Development Cause Epilepsy. Front Neurosci 2019; 13:250. [PMID: 30983952 PMCID: PMC6450262 DOI: 10.3389/fnins.2019.00250] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 03/04/2019] [Indexed: 12/13/2022] Open
Abstract
Malformations of cortical development (MCDs), a complex family of rare disorders, result from alterations of one or combined developmental steps, including progenitors proliferation, neuronal migration and differentiation. They are an important cause of childhood epilepsy and frequently associate cognitive deficits and behavioral alterations. Though the physiopathological mechanisms of epilepsy in MCD patients remain poorly elucidated, research during the past decade highlighted the contribution of some factors that will be reviewed in this paper and that include: (i) the genes that caused the malformation, that can be responsible for a significant reduction of inhibitory cells (e.g., ARX gene) or be inducing cell-autonomous epileptogenic changes in affected neurons (e.g., mutations on the mTOR pathway); (ii) the alteration of cortical networks development induced by the malformation that will also involve adjacent or distal cortical areas apparently sane so that the epileptogenic focus might be more extended that the malformation or even localized at distance from it; (iii) the normal developmental processes that would influence and determine the onset of epilepsy in MCD patients, particularly precocious in most of the cases.
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Affiliation(s)
- Alfonso Represa
- INSERM, Institut de Neurobiologie de la Méditerranée, Aix-Marseille University, Marseille, France
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45
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Histone deacetylase inhibitors restore normal hippocampal synaptic plasticity and seizure threshold in a mouse model of Tuberous Sclerosis Complex. Sci Rep 2019; 9:5266. [PMID: 30918308 PMCID: PMC6437206 DOI: 10.1038/s41598-019-41744-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/15/2019] [Indexed: 01/02/2023] Open
Abstract
Abnormal synaptic plasticity has been implicated in several neurological disorders including epilepsy, dementia and Autism Spectrum Disorder (ASD). Tuberous Sclerosis Complex (TSC) is an autosomal dominant genetic disorder that manifests with seizures, autism, and cognitive deficits. The abnormal intracellular signaling underlying TSC has been the focus of many studies. However, nothing is known about the role of histone modifications in contributing to the neurological manifestations in TSC. Dynamic regulation of chromatin structure via post translational modification of histone tails has been implicated in learning, memory and synaptic plasticity. Histone acetylation and associated gene activation plays a key role in plasticity and so we asked whether histone acetylation might be dysregulated in TSC. In this study, we report a general reduction in hippocampal histone H3 acetylation levels in a mouse model of TSC2. Pharmacological inhibition of Histone Deacetylase (HDAC) activity restores histone H3 acetylation levels and ameliorates the aberrant plasticity in TSC2+/− mice. We describe a novel seizure phenotype in TSC2+/− mice that is also normalized with HDAC inhibitors (HDACis). The results from this study suggest an unanticipated role for chromatin modification in TSC and may inform novel therapeutic strategies for TSC patients.
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Okamoto SI, Prikhodko O, Pina-Crespo J, Adame A, McKercher SR, Brill LM, Nakanishi N, Oh CK, Nakamura T, Masliah E, Lipton SA. NitroSynapsin for the treatment of neurological manifestations of tuberous sclerosis complex in a rodent model. Neurobiol Dis 2019; 127:390-397. [PMID: 30928642 DOI: 10.1016/j.nbd.2019.03.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/07/2019] [Accepted: 03/26/2019] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis (TSC) is an autosomal dominant disorder caused by heterozygous mutations in the TSC1 or TSC2 gene. TSC is often associated with neurological, cognitive, and behavioral deficits. TSC patients also express co-morbidity with anxiety and mood disorders. The mechanism of pathogenesis in TSC is not entirely clear, but TSC-related neurological symptoms are accompanied by excessive glutamatergic activity and altered synaptic spine structures. To address whether extrasynaptic (e)NMDA-type glutamate receptor (NMDAR) antagonists, as opposed to antagonists that block physiological phasic synaptic activity, can ameliorate the synaptic and behavioral features of this disease, we utilized the Tsc2+/- mouse model of TSC to measure biochemical, electrophysiological, histological, and behavioral parameters in the mice. We found that antagonists that preferentially block tonic activity as found at eNMDARs, particularly the newer drug NitroSynapsin, provide biological and statistically significant improvement in Tsc2+/- phenotypes. Accompanying this improvement was correction of activity in the p38 MAPK-TSC-Rheb-mTORC1-S6K1 pathway. Deficits in hippocampal long-term potentiation (LTP), histological loss of synapses, and behavioral fear conditioning in Tsc2+/- mice were all improved after treatment with NitroSynapsin. Taken together, these results suggest that amelioration of excessive excitation, by limiting aberrant eNMDAR activity, may represent a novel treatment approach for TSC.
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Affiliation(s)
| | - Olga Prikhodko
- Biomedical Sciences Graduate Program, University of California San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Juan Pina-Crespo
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Anthony Adame
- Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Scott R McKercher
- Scintillon Institute, San Diego, CA 92121, USA; Neuroscience Translational Center, Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Laurence M Brill
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Chang-Ki Oh
- Scintillon Institute, San Diego, CA 92121, USA; Neuroscience Translational Center, Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Tomohiro Nakamura
- Scintillon Institute, San Diego, CA 92121, USA; Neuroscience Translational Center, Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA 92093, USA
| | - Stuart A Lipton
- Scintillon Institute, San Diego, CA 92121, USA; Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA 92093, USA; Neuroscience Translational Center, Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
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Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
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Abstract
PURPOSE OF REVIEW Focal cortical dysplasias (FCDs) represent common cortical malformations that are frequently associated with epilepsy. They have so far not been well understood in terms of their molecular pathogenesis, and with respect to mechanisms of seizure emergence. RECENT FINDINGS Several recent studies have succeeded in making significant advances in understanding the molecular genetics, in particular FCD type II. A second major advance has been the development of novel rodent models of FCDs that replicate a somatic mutation seen in humans, lead to a focal lesion, and recapitulate many phenotypic features of human FCDs. We will discuss these recent advances. SUMMARY These advances promise significant advances in understanding the heterogeneity of FCDs at the molecular genetic level. They also promise a much better understanding of cell-intrinsic and network mechanisms underlying increased seizure susceptibility and altered cognition. Systematic studies utilizing the approaches summarized here promise to lead to specific strategies regarding when and how to treat specific subgroups of FCDs.
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49
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Mellone M, Zianni E, Stanic J, Campanelli F, Marino G, Ghiglieri V, Longhi A, Thiolat ML, Li Q, Calabresi P, Bezard E, Picconi B, Di Luca M, Gardoni F. NMDA receptor GluN2D subunit participates to levodopa-induced dyskinesia pathophysiology. Neurobiol Dis 2019; 121:338-349. [DOI: 10.1016/j.nbd.2018.09.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/11/2018] [Accepted: 09/23/2018] [Indexed: 12/17/2022] Open
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50
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Abstract
The mechanistic target of rapamycin (mTOR) is an important signaling hub that integrates environmental information regarding energy availability and stimulates anabolic molecular processes and cell growth. Abnormalities in this pathway have been identified in several syndromes in which autism spectrum disorder (ASD) is highly prevalent. Several studies have investigated mTOR signaling in developmental and neuronal processes that, when dysregulated, could contribute to the development of ASD. Although many potential mechanisms still remain to be fully understood, these associations are of great interest because of the clinical availability of mTOR inhibitors. Clinical trials evaluating the efficacy of mTOR inhibitors to improve neurodevelopmental outcomes have been initiated.
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Affiliation(s)
- Kellen D. Winden
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Darius Ebrahimi-Fakhari
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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