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Hwu WL, Chang K, Liu YH, Wang HC, Lee NC, Chien YH. Gene therapy corrects the neurological deficits of mice with sialidosis. Gene Ther 2024; 31:263-272. [PMID: 38321198 DOI: 10.1038/s41434-024-00443-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 01/14/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024]
Abstract
Patients with sialidosis (mucolipidosis type I) type I typically present with myoclonus, seizures, ataxia, cherry-red spots, and blindness because of mutations in the neuraminidase 1 (NEU1) gene. Currently, there is no treatment for sialidosis. In this study, we developed an adeno-associated virus (AAV)-mediated gene therapy for a Neu1 knockout (Neu1-/-) mouse model of sialidosis. The vector, AAV9-P3-NP, included the human NEU1 promoter, NEU1 cDNA, IRES, and CTSA cDNA. Untreated Neu1-/- mice showed astrogliosis and microglial LAMP1 accumulation in the nervous system, including brain, spinal cord, and dorsal root ganglion, together with impaired motor function. Coexpression of NEU1 and protective protein/cathepsin A (PPCA) in neonatal Neu1-/- mice by intracerebroventricular injection, and less effective by facial vein injection, decreased astrogliosis and LAMP1 accumulation in the nervous system and improved rotarod performance of the treated mice. Facial vein injection also improved the grip strength and survival of Neu1-/- mice. Therefore, cerebrospinal fluid delivery of AAV9-P3-NP, which corrects the neurological deficits of mice with sialidosis, could be a suitable treatment for patients with sialidosis type I. After intracerebroventricular or facial vein injection of AAV vectors, NEU1 and PPCA are expressed together. PPCA-protected NEU1 is then sent to lysosomes, where β-Gal binds to this complex to form a multienzyme complex in order to execute its function.
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Affiliation(s)
- Wuh-Liang Hwu
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC.
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan, ROC.
- Precision Medical Center, China Medical University Hospital, Taichung City, Taiwan, ROC.
| | - Karine Chang
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Yu-Han Liu
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Hao-Chun Wang
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Ni-Chung Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Yin-Hsiu Chien
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan, ROC
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Benedetti MC, D'andrea T, Colantoni A, Silachev D, de Turris V, Boussadia Z, Babenko VA, Volovikov EA, Belikova L, Bogomazova AN, Pepponi R, Whye D, Buttermore ED, Tartaglia GG, Lagarkova MA, Katanaev VL, Musayev I, Martinelli S, Fucile S, Rosa A. Cortical neurons obtained from patient-derived iPSCs with GNAO1 p.G203R variant show altered differentiation and functional properties. Heliyon 2024; 10:e26656. [PMID: 38434323 PMCID: PMC10907651 DOI: 10.1016/j.heliyon.2024.e26656] [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: 08/03/2023] [Revised: 01/24/2024] [Accepted: 02/16/2024] [Indexed: 03/05/2024] Open
Abstract
Pathogenic variants in the GNAO1 gene, encoding the alpha subunit of an inhibitory heterotrimeric guanine nucleotide-binding protein (Go) highly expressed in the mammalian brain, have been linked to encephalopathy characterized by different combinations of neurological symptoms, including developmental delay, hypotonia, epilepsy and hyperkinetic movement disorder with life-threatening paroxysmal exacerbations. Currently, there are only symptomatic treatments, and little is known about the pathophysiology of GNAO1-related disorders. Here, we report the characterization of a new in vitro model system based on patient-derived induced pluripotent stem cells (hiPSCs) carrying the recurrent p.G203R amino acid substitution in Gαo, and a CRISPR-Cas9-genetically corrected isogenic control line. RNA-Seq analysis highlighted aberrant cell fate commitment in neuronal progenitor cells carrying the p.G203R pathogenic variant. Upon differentiation into cortical neurons, patients' cells showed reduced expression of early neural genes and increased expression of astrocyte markers, as well as premature and defective differentiation processes leading to aberrant formation of neuronal rosettes. Of note, comparable defects in gene expression and in the morphology of neural rosettes were observed in hiPSCs from an unrelated individual harboring the same GNAO1 variant. Functional characterization showed lower basal intracellular free calcium concentration ([Ca2+]i), reduced frequency of spontaneous activity, and a smaller response to several neurotransmitters in 40- and 50-days differentiated p.G203R neurons compared to control cells. These findings suggest that the GNAO1 pathogenic variant causes a neurodevelopmental phenotype characterized by aberrant differentiation of both neuronal and glial populations leading to a significant alteration of neuronal communication and signal transduction.
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Affiliation(s)
- Maria Cristina Benedetti
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Tiziano D'andrea
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, Rome, Italy
| | - Alessio Colantoni
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Denis Silachev
- School of Medicine and Life Sciences, Far Eastern Federal University, 690090, Vladivostok, Russia
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, 119992, Moscow, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | - Valeria de Turris
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Zaira Boussadia
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Valentina A. Babenko
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, 119992, Moscow, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | - Egor A. Volovikov
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Lilia Belikova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Alexandra N. Bogomazova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Rita Pepponi
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Dosh Whye
- Human Neuron Core, Rosamund Stone Zander Translational Neuroscience Center and F.M. Kirby Neurobiology Department, Boston Children's Hospital, Boston, MA, USA
| | - Elizabeth D. Buttermore
- Human Neuron Core, Rosamund Stone Zander Translational Neuroscience Center and F.M. Kirby Neurobiology Department, Boston Children's Hospital, Boston, MA, USA
| | - Gian Gaetano Tartaglia
- Center for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Maria A. Lagarkova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Vladimir L. Katanaev
- School of Medicine and Life Sciences, Far Eastern Federal University, 690090, Vladivostok, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | | | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Sergio Fucile
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Alessandro Rosa
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
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Miralles RM, Boscia AR, Kittur S, Vundela SR, Wengert ER, Patel MK. Parvalbumin Interneuron Impairment Leads to Synaptic Transmission Deficits and Seizures in SCN8A Epileptic Encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579511. [PMID: 38464208 PMCID: PMC10925130 DOI: 10.1101/2024.02.09.579511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
SCN8A epileptic encephalopathy (EE) is a severe epilepsy syndrome resulting from de novo mutations in the voltage-gated sodium channel Na v 1.6, encoded by the gene SCN8A . Na v 1.6 is expressed in both excitatory and inhibitory neurons, yet previous studies have primarily focused on the impact SCN8A mutations have on excitatory neuron function, with limited studies on the importance of inhibitory interneurons to seizure onset and progression. Inhibitory interneurons are critical in balancing network excitability and are known to contribute to the pathophysiology of other epilepsies. Parvalbumin (PV) interneurons are the most prominent inhibitory neuron subtype in the brain, making up about 40% of inhibitory interneurons. Notably, PV interneurons express high levels of Na v 1.6. To assess the role of PV interneurons within SCN8A EE, we used two mouse models harboring patient-derived SCN8A gain-of-function mutations, Scn8a D/+ , where the SCN8A mutation N1768D is expressed globally, and Scn8a W/+ -PV, where the SCN8A mutation R1872W is selectively expressed in PV interneurons. Expression of the R1872W SCN8A mutation selectively in PV interneurons led to the development of spontaneous seizures in Scn8a W/+ -PV mice and seizure-induced death, decreasing survival compared to wild-type. Electrophysiology studies showed that PV interneurons in Scn8a D/+ and Scn8a W/+ -PV mice were susceptible to depolarization block, a state of action potential failure. Scn8a D/+ and Scn8a W/+ -PV interneurons also exhibited increased persistent sodium current, a hallmark of SCN8A gain-of-function mutations that contributes to depolarization block. Evaluation of synaptic connections between PV interneurons and pyramidal cells showed an increase in synaptic transmission failure at high frequencies (80-120Hz) as well as an increase in synaptic latency in Scn8a D/+ and Scn8a W/+ -PV interneurons. These data indicate a distinct impairment of synaptic transmission in SCN8A EE, potentially decreasing overall cortical network inhibition. Together, our novel findings indicate that failure of PV interneuron spiking via depolarization block along with frequency-dependent inhibitory synaptic impairment likely elicits an overall reduction in the inhibitory drive in SCN8A EE, leading to unchecked excitation and ultimately resulting in seizures and seizure-induced death.
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Cherkezzade M, Soylu S, Tüzün E, Yılmaz V, Sezgin M, Yapıcı Z, Küçükali Cİ, Topaloğlu P. The Association Between Serum Levels of Glial Biomarkers, Clinical Severity and Electro-encephalography Features in Idiopathic West and Lennox-Gastaut Syndromes. Noro Psikiyatr Ars 2024; 61:128-134. [PMID: 38868840 PMCID: PMC11165615 DOI: 10.29399/npa.28669] [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: 11/24/2023] [Accepted: 01/03/2024] [Indexed: 06/14/2024] Open
Abstract
Introduction Although the contribution of enhanced glial activity in seizure induction is increasingly recognized, the role of glia-induced neuroinflammation in the physiopathology of epileptic encephalopathy (EE) has been scarcely investigated. Methods To delineate the contribution of glial activity in EE, we measured levels of glia-derived mediators with previously described biomarker value, including glial fibrillary acidic protein (GFAP), high mobility group box 1 (HMGB1), chitinase-3-like protein 1 (CHI3L1), soluble CD163 (sCD163) and triggering receptor expressed on myeloid cells 2 (TREM2) by ELISA in sera of patients with idiopathic West syndrome (WS, n=18), idiopathic Lennox-Gastaut syndrome (LGS, n=13) and healthy controls (n=31). Results Patients with EE showed significantly higher CHI3L1 levels compared to healthy controls. Levels of HMGB1, CHI3L1, sCD163 and TREM2 were higher in LGS patients than WS patients and/or healthy controls. One or more of the investigated mediators were associated with treatment responsiveness, disease severity and presence of pathological features on electroencephalography (EEG). Conclusions To our knowledge, our findings provide the initial patient-based evidence that astrocyte- and microglia-mediated neuroinflammation might be involved in the pathogenesis of LGS and WS. Moreover, glial mediators may serve as prognostic biomarkers in patients with idiopathic EE.
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Affiliation(s)
- Minara Cherkezzade
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Division of Child Neurology, Istanbul, Turkey
| | - Selen Soylu
- Istanbul University, Aziz Sancar Experimental Medicine Research Institute, Department of Neuroscience, Istanbul, Turkey
| | - Erdem Tüzün
- Istanbul University, Aziz Sancar Experimental Medicine Research Institute, Department of Neuroscience, Istanbul, Turkey
| | - Vuslat Yılmaz
- Istanbul University, Aziz Sancar Experimental Medicine Research Institute, Department of Neuroscience, Istanbul, Turkey
| | - Mine Sezgin
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Istanbul, Turkey
| | - Zuhal Yapıcı
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Division of Child Neurology, Istanbul, Turkey
| | - Cem İsmail Küçükali
- Istanbul University, Aziz Sancar Experimental Medicine Research Institute, Department of Neuroscience, Istanbul, Turkey
| | - Pınar Topaloğlu
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, Division of Child Neurology, Istanbul, Turkey
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Manis AD, Cook-Snyder DR, Duffy E, Osmani WA, Eilbes M, Dillard M, Palygin O, Staruschenko A, Hodges MR. Repeated seizures lead to progressive ventilatory dysfunction in SS Kcnj16-/- rats. J Appl Physiol (1985) 2023; 135:872-885. [PMID: 37535709 PMCID: PMC10642517 DOI: 10.1152/japplphysiol.00072.2023] [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: 02/06/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 08/05/2023] Open
Abstract
Patients with uncontrolled epilepsy experience repeated seizures putting them at increased risk for sudden unexpected death in epilepsy (SUDEP). Data from human patients have led to the hypothesis that SUDEP results from severe cardiorespiratory suppression after a seizure, which may involve pathological deficiencies in the brainstem serotonin (5-HT) system. Rats with a genomic Kcnj16 mutation (SSKcnj16-/- rats) are susceptible to sound-induced generalized tonic-clonic seizures (GTCS) which, when repeated once daily for up to 10 days (10-day seizure protocol), increased mortality, particularly in male rats. Here, we test the hypothesis that repeated seizures across the 10-day protocol will cause a progressive ventilatory dysfunction due to time-dependent 5-HT deficiency. Initial severe seizures led to ictal and postictal apneas and transient decreases in breathing frequency, ventilatory drive, breath-to-breath variability, and brief hypoventilation. These seizure-induced effects on ventilation were exacerbated with increasing seizures and ventilatory chemoreflexes became further impaired after repeated seizures. Tissue analyses of key brainstem regions controlling breathing showed time-dependent 5-HT system suppression and increased immunoreactivity for IBA-1 (microglial marker) without changes in overall cell counts at 3, 7, and 10 days of seizures. Fluoxetine treatment in SSKcnj16-/- rats prevented repeated seizure-induced progressive respiratory suppression but failed to prevent seizure-related mortality. We conclude that repeated seizures cause a progressive compromise of ventilatory control in the immediate postictal period largely mediated by serotonin system suppression in brainstem regions of respiratory control. However, other unknown factors contribute to overall survival following repeated seizures in this model.NEW & NOTEWORTHY This study demonstrated that repeated seizures in a novel rat model (SSKcnj16-/- rats) caused a progressively greater ventilatory dysfunction in the immediate postictal period associated with brainstem serotonin (5-HT) suppression. Augmenting brain 5-HT with a selective serotonin reuptake inhibitor prevented the progressive ventilatory dysfunction induced by repeated seizures but failed to prevent seizure-related mortality, suggesting that repeated seizures may lead to cardiorespiratory suppression and failure through multiple mechanisms.
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Affiliation(s)
- Anna D Manis
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Denise R Cook-Snyder
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Erin Duffy
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Wasif A Osmani
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Melissa Eilbes
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Matthew Dillard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Molecular Pharmacology & Physiology, University of South Florida, Tampa, Florida, United States
- James A. Haley Veterans' Hospital, Tampa, Florida, United States
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Çarçak N, Onat F, Sitnikova E. Astrocytes as a target for therapeutic strategies in epilepsy: current insights. Front Mol Neurosci 2023; 16:1183775. [PMID: 37583518 PMCID: PMC10423940 DOI: 10.3389/fnmol.2023.1183775] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/12/2023] [Indexed: 08/17/2023] Open
Abstract
Astrocytes are specialized non-neuronal glial cells of the central nervous system, contributing to neuronal excitability and synaptic transmission (gliotransmission). Astrocytes play a key roles in epileptogenesis and seizure generation. Epilepsy, as a chronic disorder characterized by neuronal hyperexcitation and hypersynchronization, is accompanied by substantial disturbances of glial cells and impairment of astrocytic functions and neuronal signaling. Anti-seizure drugs that provide symptomatic control of seizures primarily target neural activity. In epileptic patients with inadequate control of seizures with available anti-seizure drugs, novel therapeutic candidates are needed. These candidates should treat epilepsy with anti-epileptogenic and disease-modifying effects. Evidence from human and animal studies shows that astrocytes have value for developing new anti-seizure and anti-epileptogenic drugs. In this review, we present the key functions of astrocytes contributing to neuronal hyperexcitability and synaptic activity following an etiology-based approach. We analyze the role of astrocytes in both development (epileptogenesis) and generation of seizures (ictogenesis). Several promising new strategies that attempted to modify astroglial functions for treating epilepsy are being developed: (1) selective targeting of glia-related molecular mechanisms of glutamate transport; (2) modulation of tonic GABA release from astrocytes; (3) gliotransmission; (4) targeting the astrocytic Kir4.1-BDNF system; (5) astrocytic Na+/K+/ATPase activity; (6) targeting DNA hypo- or hypermethylation of candidate genes in astrocytes; (7) targeting astrocytic gap junction regulators; (8) targeting astrocytic adenosine kinase (the major adenosine-metabolizing enzyme); and (9) targeting microglia-astrocyte communication and inflammatory pathways. Novel disease-modifying therapeutic strategies have now been developed, such as astroglia-targeted gene therapy with a broad spectrum of genetic constructs to target astroglial cells.
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Affiliation(s)
- Nihan Çarçak
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey
- Institute of Health Sciences, Department of Neuroscience, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Filiz Onat
- Institute of Health Sciences, Department of Neuroscience, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
- Department of Medical Pharmacology, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Evgenia Sitnikova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
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Lindquist BE, Timbie C, Voskobiynyk Y, Paz JT. Thalamocortical circuits in generalized epilepsy: Pathophysiologic mechanisms and therapeutic targets. Neurobiol Dis 2023; 181:106094. [PMID: 36990364 PMCID: PMC10192143 DOI: 10.1016/j.nbd.2023.106094] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/02/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023] Open
Abstract
Generalized epilepsy affects 24 million people globally; at least 25% of cases remain medically refractory. The thalamus, with widespread connections throughout the brain, plays a critical role in generalized epilepsy. The intrinsic properties of thalamic neurons and the synaptic connections between populations of neurons in the nucleus reticularis thalami and thalamocortical relay nuclei help generate different firing patterns that influence brain states. In particular, transitions from tonic firing to highly synchronized burst firing mode in thalamic neurons can cause seizures that rapidly generalize and cause altered awareness and unconsciousness. Here, we review the most recent advances in our understanding of how thalamic activity is regulated and discuss the gaps in our understanding of the mechanisms of generalized epilepsy syndromes. Elucidating the role of the thalamus in generalized epilepsy syndromes may lead to new opportunities to better treat pharmaco-resistant generalized epilepsy by thalamic modulation and dietary therapy.
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Affiliation(s)
- Britta E Lindquist
- UCSF Department of Neurology, Division of Neurocritical Care, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Clare Timbie
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America; Kavli Institute for Fundamental Neuroscience, UCSF, United States of America.
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8
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Vezzani A, Ravizza T, Bedner P, Aronica E, Steinhäuser C, Boison D. Astrocytes in the initiation and progression of epilepsy. Nat Rev Neurol 2022; 18:707-722. [PMID: 36280704 PMCID: PMC10368155 DOI: 10.1038/s41582-022-00727-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2022] [Indexed: 11/09/2022]
Abstract
Epilepsy affects ~65 million people worldwide. First-line treatment options include >20 antiseizure medications, but seizure control is not achieved in approximately one-third of patients. Antiseizure medications act primarily on neurons and can provide symptomatic control of seizures, but do not alter the onset and progression of epilepsy and can cause serious adverse effects. Therefore, medications with new cellular and molecular targets and mechanisms of action are needed. Accumulating evidence indicates that astrocytes are crucial to the pathophysiological mechanisms of epilepsy, raising the possibility that these cells could be novel therapeutic targets. In this Review, we discuss how dysregulation of key astrocyte functions - gliotransmission, cell metabolism and immune function - contribute to the development and progression of hyperexcitability in epilepsy. We consider strategies to mitigate astrocyte dysfunction in each of these areas, and provide an overview of how astrocyte activation states can be monitored in vivo not only to assess their contribution to disease but also to identify markers of disease processes and treatment effects. Improved understanding of the roles of astrocytes in epilepsy has the potential to lead to novel therapies to prevent the initiation and progression of epilepsy.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy.
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA
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