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Hammer M, Krzyzaniak C, Bahramnejad E, Smelser K, Hack J, Watkins J, Ronaldson P. Sex differences in physiological response to increased neuronal excitability in a knockin mouse model of pediatric epilepsy. Clin Sci (Lond) 2024; 138:205-223. [PMID: 38348743 PMCID: PMC10881277 DOI: 10.1042/cs20231572] [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: 11/29/2023] [Revised: 02/01/2024] [Accepted: 02/09/2024] [Indexed: 02/22/2024]
Abstract
BACKGROUND Epilepsy is a common neurological disease; however, few if any of the currently marketed antiseizure medications prevent or cure epilepsy. Discovery of pathological processes in the early stages of epileptogenesis has been challenging given the common use of preclinical models that induce seizures in physiologically normal animals. Moreover, despite known sex dimorphism in neurological diseases, females are rarely included in preclinical epilepsy models. METHODS We characterized sex differences in mice carrying a pathogenic knockin variant (p.N1768D) in the Scn8a gene that causes spontaneous tonic-clonic seizures (TCs) at ∼3 months of age and found that heterozygous females are more resilient than males in mortality and morbidity. To investigate the cellular mechanisms that underlie female resilience, we utilized blood-brain barrier (BBB) and hippocampal transcriptomic analyses in heterozygous mice before seizure onset (pre-TC) and in mice that experienced ∼20 TCs (post-TC). RESULTS In the pre-TC latent phase, both sexes exhibited leaky BBB; however, patterns of gene expression were sexually dimorphic. Females exhibited enhanced oxidative phosphorylation and protein biogenesis, while males activated gliosis and CREB signaling. After seizure onset (chronic phase), females exhibited a metabolic switch to lipid metabolism, while males exhibited increased gliosis and BBB dysfunction and a strong activation of neuroinflammatory pathways. CONCLUSION The results underscore the central role of oxidative stress and BBB permeability in the early stages of epileptogenesis, as well as sex dimorphism in response to increasing neuronal hyperexcitability. Our results also highlight the need to include both sexes in preclinical studies to effectively translate results of drug efficacy studies.
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Affiliation(s)
- Michael F. Hammer
- BIO5 Institute, University of Arizona, Tucson, Arizona, U.S.A
- Department of Neurology, University of Arizona, Tucson, Arizona, U.S.A
| | | | - Erfan Bahramnejad
- BIO5 Institute, University of Arizona, Tucson, Arizona, U.S.A
- Department of Pharmacology, University of Arizona, Tucson, Arizona, U.S.A
| | | | - Joshua B. Hack
- BIO5 Institute, University of Arizona, Tucson, Arizona, U.S.A
| | - Joseph C. Watkins
- Department of Mathematics, University of Arizona, Tucson, Arizona, U.S.A
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Gender and Neurosteroids: Implications for Brain Function, Neuroplasticity and Rehabilitation. Int J Mol Sci 2023; 24:ijms24054758. [PMID: 36902197 PMCID: PMC10003563 DOI: 10.3390/ijms24054758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Neurosteroids are synthesized de novo in the nervous system; they mainly moderate neuronal excitability, and reach target cells via the extracellular pathway. The synthesis of neurosteroids occurs in peripheral tissues such as gonads tissues, liver, and skin; then, because of their high lipophilia, they cross the blood-brain barrier and are stored in the brain structure. Neurosteroidogenesis occurs in brain regions such as the cortex, hippocampus, and amygdala by enzymes necessary for the in situ synthesis of progesterone from cholesterol. Neurosteroids could be considered the main players in both sexual steroid-induced hippocampal synaptic plasticity and normal transmission in the hippocampus. Moreover, they show a double function of increasing spine density and enhancing long term potentiation, and have been related to the memory-enhancing effects of sexual steroids. Estrogen and progesterone affect neuronal plasticity differently in males and females, especially regarding changes in the structure and function of neurons in different regions of the brain. Estradiol administration in postmenopausal women allowed for improving cognitive performance, and the combination with aerobic motor exercise seems to enhance this effect. The paired association between rehabilitation and neurosteroids treatment could provide a boosting effect in order to promote neuroplasticity and therefore functional recovery in neurological patients. The aim of this review is to investigate the mechanisms of action of neurosteroids as well as their sex-dependent differences in brain function and their role in neuroplasticity and rehabilitation.
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Xu Y, Fan Q. Relationship between chronic hypoxia and seizure susceptibility. CNS Neurosci Ther 2022; 28:1689-1705. [PMID: 35983626 PMCID: PMC9532927 DOI: 10.1111/cns.13942] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 01/16/2023] Open
Abstract
Chronic hypobaric hypoxia in high‐altitude areas is closely related to the occurrence of many neurological diseases. Among these diseases, epilepsy is a common disease of the nervous system that is difficult to diagnose and treat, with a long treatment cycle. As of 2019, there were more than 70 million epilepsy patients worldwide, including 10 million in China. Studies have shown that chronic hypoxia promotes the occurrence and development of epilepsy, and elucidation of the relationship between chronic hypoxia and epilepsy is important for studying the pathogenesis of epilepsy and exploring the potential characteristics of epilepsy and new drug targets for epilepsy. In this article, we review the factors that may cause increased seizure susceptibility in chronic hypoxia and consider the potential relationship between chronic hypobaric hypoxia and seizure susceptibility in high‐altitude areas and prospects surrounding related research in the future.
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Affiliation(s)
- YuanHang Xu
- Qinghai University Graduate School, Xining, China.,Department of Neurology, Qinghai Provincial People's Hospital Xining, Xining, China
| | - QingLi Fan
- Department of Neurology, Qinghai Provincial People's Hospital Xining, Xining, China
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Li N, Li J, Chen Y, Chu C, Lin W. Treatment Outcome and Risk Factors of Adult Newly Diagnosed Epilepsy: A Prospective Hospital-Based Study in Northeast China. Front Neurol 2021; 12:747958. [PMID: 34777218 PMCID: PMC8581653 DOI: 10.3389/fneur.2021.747958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/06/2021] [Indexed: 12/19/2022] Open
Abstract
Objective: The study was conducted to summarize the treatment outcomes of newly diagnosed epilepsy (NDE) and analyse the risk factors for refractory epilepsy (RE) in Northeast China. Methods: A total of 466 adult patients with NDE were consecutively enrolled in this programme. Clinical data were collected at baseline and each follow-up. Several scales concerning recognition and mood were also completed at the first visit. Results: Seizure-free status was achieved by 52% (n = 244) of the patients; however, 15% (n = 68) manifested RE. A total of 286 (61%) patients continued with the first ASM as monotherapy, among which 186 (40%) patients became seizure-free. Fifteen (22%) patients with RE became seizure-free following ASM adjustment and 34 patients (14%) had breakthrough seizures after being classified as seizure-free. One patient developed RE after attaining seizure-free status. Breakthrough seizures during the first expected interictal interval [Odds ratio (OR) = 5.81, 95% CI: 2.70–12.50], high seizure frequency at baseline (OR = 1.24, 95% CI: 1.04–1.49), younger age of onset (OR = 1.42, 95% CI: 1.12–1.79), and male sex (OR = 2.64, 95% CI: 1.26–5.53) were risk factors for RE. Significance: Treatment outcomes of the majority of NDE cases are good. New risk factors could help physicians more promptly and accurately identify patients who are likely to develop RE. Seizure-free state is not long enough to commence the withdrawal of ASMs. RE is not permanent and seizure-free may be achieved subsequently by appropriate drug adjustment.
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Affiliation(s)
- Nan Li
- DDepartment of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Jing Li
- DDepartment of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Yanyan Chen
- DDepartment of Neurology, The First Hospital of Jilin University, Changchun, China.,Department of Neuroelectrophysiology, Changchun Six Hospital, Changchun, China
| | - Chaojia Chu
- DDepartment of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Weihong Lin
- DDepartment of Neurology, The First Hospital of Jilin University, Changchun, China
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Suwarba IGNM, Mahalini DS, Widyakusuma IGNAJ. The Relationship between Hair Zinc Levels and Drug-resistant Epilepsy in Children at Sanglah Hospital. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.6729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND: Drug-resistant epilepsy (DRE) is epilepsy that is failed to achieve free of seizure after adequate trials of two tolerated and appropriately chosen antiepileptic drugs. Zinc deficiency could trigger the onset of various neurological disorders, including seizures in epilepsy.
AIM: The objective of the study was to determine the relationship between hair zinc levels and DRE in children at Sanglah Hospital, Denpasar.
METHODS: This is an analytic observational study using a cross-sectional design, involving 74 subjects. The inclusion criteria were children aged 1 month–18 years who had been diagnosed with epilepsy. Chi-square test and multivariate analysis with logistic regression were used to assess the relation between hair zinc levels and DRE in children.
RESULTS: Multivariate analysis found a relationship between low hair zinc level and DRE in children (PR 8.0; 95% CI 2.0–32.2; p = 0.003). The duration of therapy (PR 16.0; 95% CI 3.9–65.4; p = 0.000) and structural abnormalities (PR 4.1; 95% CI 1.1–14.9; p = 0.028) also increased the risk of DRE in this study.
CONCLUSION: Low hair zinc level is associated with DRE in children.
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The Alteration of Chloride Homeostasis/GABAergic Signaling in Brain Disorders: Could Oxidative Stress Play a Role? Antioxidants (Basel) 2021; 10:antiox10081316. [PMID: 34439564 PMCID: PMC8389245 DOI: 10.3390/antiox10081316] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022] Open
Abstract
In neuronal precursors and immature neurons, the depolarizing (excitatory) effect of γ-Aminobutyric acid (GABA) signaling is associated with elevated [Cl−]i; as brain cells mature, a developmental switch occurs, leading to the decrease of [Cl−]i and to the hyperpolarizing (inhibitory) effect of GABAergic signaling. [Cl−]i is controlled by two chloride co-transporters: NKCC1, which causes Cl− to accumulate into the cells, and KCC2, which extrudes it. The ontogenetic upregulation of the latter determines the above-outlined switch; however, many other factors contribute to the correct [Cl−]i in mature neurons. The dysregulation of chloride homeostasis is involved in seizure generation and has been associated with schizophrenia, Down’s Syndrome, Autism Spectrum Disorder, and other neurodevelopmental disorders. Recently, much effort has been put into developing new drugs intended to inhibit NKCC1 activity, while no attention has been paid to the origin of [Cl−]i dysregulation. Our study examines the pathophysiology of Cl− homeostasis and focuses on the impact of oxidative stress (OS) and inflammation on the activity of Cl− co-transporters, highlighting the relevance of OS in numerous brain abnormalities and diseases. This hypothesis supports the importance of primary prevention during pregnancy. It also integrates the therapeutic framework addressed to restore normal GABAergic signaling by counteracting the alteration in chloride homeostasis in central nervous system (CNS) cells, aiming at limiting the use of drugs that potentially pose a health risk.
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Videira G, Gabriel D, Freitas J, Samões R, Chorão R, Lopes J, Ramalheira J, Lemos C, Leal B, da Silva AM, Chaves J. Female preponderance in genetic generalized epilepsies. Seizure 2021; 91:167-171. [PMID: 34171625 DOI: 10.1016/j.seizure.2021.06.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/26/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022] Open
Abstract
INTRODUCTION Epilepsy is more prevalent in men but Genetic Generalized Epilepsies (GGE) seem to be more common in women. A predominant maternal inheritance has been previously described in GGE. Our objective was to determine sex and inheritance patterns in a GGE population compared to mesial temporal lobe epilepsy with hippocampal sclerosis (MTLEHS). METHODS We performed a prospective observational study including adult GGE and MTLEHS patients followed up at a tertiary epilepsy center from January 2016 to December 2019. Patients' familial history was obtained by a detailed questionnaire. Clinical and demographic data was retrieved from clinical notes. RESULTS A cohort of 641 patients, 403 with GGE and 238 with MTLEHS, was analyzed. GGE was more common in women than MTLEHS (58.8% vs 44.5%, OR=1.63, p = 0.004). Compared to MTLEHS patients, more GGE patients had familial history of epilepsy (45.4% vs 25.2%; p<0.001). The GGE group had a higher percentage of female relatives with epilepsy (55% vs 37%; p = 0.006). The prevalence of maternal inheritance was not different between GGE and MTLEHS groups (62.9% vs 57.7%; p = 0.596). Photosensitivity was more common in females than in males (44.7% vs 34.3%, p = 0.036). CONCLUSION There is a female preponderance in GGE when compared to MTLEHS, as both GGE patients and their affected relatives are more frequently women. The prevalence of maternal inheritance was not higher in GGE than in MTLEHS.
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Affiliation(s)
- Gonçalo Videira
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal.
| | - Denis Gabriel
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Joel Freitas
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Raquel Samões
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Rui Chorão
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - João Lopes
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - João Ramalheira
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal
| | - Carolina Lemos
- UnIGENe, IBMC - Institute for Molecular and Cell Biology, i3S - Instituto de Investigação e Inovação em Saúde, University of Porto, Portugal; Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - Bárbara Leal
- Immunogenetics Laboratory, Pathology and Molecular Immunology Department, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - António Martins da Silva
- Neurophysiology Department, Centro Hospitalar Universitário do Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
| | - João Chaves
- Neurology Department, Centro Hospitalar Universitário do Porto, Portugal; Biomedical Investigation Multidisciplinary Unit, Abel Salazar Biomedical Sciences Institute, University of Porto, Portugal
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Mary L, Nourisson E, Feger C, Laugel V, Chaigne D, Keren B, Afenjar A, Billette T, Trost D, Cieuta-Walti C, Gerard B, Piton A, Schaefer E. Pathogenic variants in KCNQ2 cause intellectual deficiency without epilepsy: Broadening the phenotypic spectrum of a potassium channelopathy. Am J Med Genet A 2021; 185:1803-1815. [PMID: 33754465 DOI: 10.1002/ajmg.a.62181] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/19/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022]
Abstract
High-throughput sequencing (HTS) improved the molecular diagnosis in individuals with intellectual deficiency (ID) and helped to broaden the phenotype of previously known disease-causing genes. We report herein four unrelated patients with isolated ID, carriers of a likely pathogenic variant in KCNQ2, a gene usually implicated in benign familial neonatal seizures (BFNS) or early onset epileptic encephalopathy (EOEE). Patients were diagnosed by targeted HTS or exome sequencing. Pathogenicity of the variants was assessed by multiple in silico tools. Patients' ID ranged from mild to severe with predominance of speech disturbance and autistic features. Three of the four variants disrupted the same amino acid. Compiling all the pathogenic variants previously reported, we observed a strong overlap between variants causing EOEE, isolated ID, and BFNS and an important intra-familial phenotypic variability, although missense variants in the voltage-sensing domain and the pore are significantly associated to EOEE (p < 0.01, Fisher test). Thus, pathogenic variants in KCNQ2 can be associated with isolated ID. We did not highlight strong related genotype-phenotype correlations in KCNQ2-related disorders. A second genetic hit, a burden of rare variants, or other extrinsic factors may explain such a phenotypic variability. However, it is of interest to study encephalopathy genes in non-epileptic ID patients.
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Affiliation(s)
- Laura Mary
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Elsa Nourisson
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Claire Feger
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Vincent Laugel
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Denys Chaigne
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe de Recherche Clinique "Déficiences Intellectuelles et Autisme," Université Pierre et Marie Curie, Hôpital de la Pitié-Salpêtrière, Paris, France.,Institut du Cerveau et de la Moelle Épinière, Sorbonne Universités, Université Pierre et Marie Curie (Université Paris 06), UMRS 1127, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Alexandra Afenjar
- Centre de Référence Déficiences Intellectuelles de Causes Rares, Département de Génétique et Embryologie Médicale, Hôpital Trousseau, Sorbonne Universités, Paris, France
| | - Thierry Billette
- Assistance Publique-Hôpitaux de Paris, Service de Neuropédiatrie, Hôpital Armand Trousseau, Paris, France
| | | | | | - Bénédicte Gerard
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Amélie Piton
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR-7104, Inserm U964, Université de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d'Alsace, Strasbourg, France
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Hayase Y, Amano S, Hashizume K, Tominaga T, Miyamoto H, Kanno Y, Ueno-Inoue Y, Inoue T, Yamada M, Ogata S, Balan S, Hayashi K, Miura Y, Tokudome K, Ohno Y, Nishijo T, Momiyama T, Yanagawa Y, Takizawa A, Mashimo T, Serikawa T, Sekine A, Nakagawa E, Takeshita E, Yoshikawa T, Waga C, Inoue K, Goto YI, Nabeshima Y, Ihara N, Yamakawa K, Taya S, Hoshino M. Down syndrome cell adhesion molecule like-1 (DSCAML1) links the GABA system and seizure susceptibility. Acta Neuropathol Commun 2020; 8:206. [PMID: 33256836 PMCID: PMC7706048 DOI: 10.1186/s40478-020-01082-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 11/15/2020] [Indexed: 12/18/2022] Open
Abstract
The Ihara epileptic rat (IER) is a mutant model with limbic-like seizures whose pathology and causative gene remain elusive. In this report, via linkage analysis, we identified Down syndrome cell adhesion molecule-like 1(Dscaml1) as the responsible gene for IER. A single base mutation in Dscaml1 causes abnormal splicing, leading to lack of DSCAML1. IERs have enhanced seizure susceptibility and accelerated kindling establishment. Furthermore, GABAergic neurons are severely reduced in the entorhinal cortex (ECx) of these animals. Voltage-sensitive dye imaging that directly presents the excitation status of brain slices revealed abnormally persistent excitability in IER ECx. This suggests that reduced GABAergic neurons may cause weak sustained entorhinal cortex activations, leading to natural kindling via the perforant path that could cause dentate gyrus hypertrophy and epileptogenesis. Furthermore, we identified a single nucleotide substitution in a human epilepsy that would result in one amino acid change in DSCAML1 (A2105T mutation). The mutant DSCAML1A2105T protein is not presented on the cell surface, losing its homophilic cell adhesion ability. We generated knock-in mice (Dscaml1A2105T) carrying the corresponding mutation and observed reduced GABAergic neurons in the ECx as well as spike-and-wave electrocorticogram. We conclude that DSCAML1 is required for GABAergic neuron placement in the ECx and suppression of seizure susceptibility in rodents. Our findings suggest that mutations in DSCAML1 may affect seizure susceptibility in humans.
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Affiliation(s)
- Yoneko Hayase
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Shigeru Amano
- Graduate School of Medicine Faculty of Health Science, Department of Laboratory Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Koichi Hashizume
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Takashi Tominaga
- Laboratory for Neural Circuit System, Institute of Neuroscience, Tokushima Bunri University, Sanuki, 769-2300, Japan
| | - Hiroyuki Miyamoto
- International Research Center for Neurointelligence (IRCN), The University of Tokyo, Tokyo, 187-8502, Japan
| | - Yukie Kanno
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Yukiko Ueno-Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Mayumi Yamada
- Research Center for Dynamic Living Systems, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8501, Japan
| | - Shigehiro Ogata
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Shabeesh Balan
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Ken Hayashi
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Yoshiki Miura
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kentaro Tokudome
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, 569-1094, Japan
| | - Yukihiro Ohno
- Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, 569-1094, Japan
| | - Takuma Nishijo
- Department of Pharmacology, Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Toshihiko Momiyama
- Department of Pharmacology, Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Yuchio Yanagawa
- Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, 371-8511, Japan
| | - Akiko Takizawa
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Tomoji Mashimo
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
- Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, 108-839, Japan
| | - Tadao Serikawa
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Akihiro Sekine
- Omics-Based Medicine, Center for Preventive Medical Science, Chiba University, Chiba, 260-0856, Japan
| | - Eiji Nakagawa
- Department of Pediatric Neurology, National Center Hospital, NCNP, Tokyo, 187-8551, Japan
| | - Eri Takeshita
- Department of Pediatric Neurology, National Center Hospital, NCNP, Tokyo, 187-8551, Japan
| | - Takeo Yoshikawa
- Laboratory for Molecular Psychiatry, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Chikako Waga
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, NCNP, Tokyo, 187-8551, Japan
| | - Yoichi Nabeshima
- Foundation for Biomedical Research and Innovation, Kobe, 650-0047, Japan
| | - Nobuo Ihara
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Kazuhiro Yamakawa
- Graduate School of Medical Science, Nagoya City University, Nagoya, 467-8601, Japan
| | - Shinichiro Taya
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-higashi, Kodaira, Tokyo, 187-8502, Japan.
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Kipnis PA, Sullivan BJ, Carter BM, Kadam SD. TrkB agonists prevent postischemic emergence of refractory neonatal seizures in mice. JCI Insight 2020; 5:136007. [PMID: 32427585 DOI: 10.1172/jci.insight.136007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/14/2020] [Indexed: 12/19/2022] Open
Abstract
Refractory neonatal seizures do not respond to first-line antiseizure medications like phenobarbital (PB), a positive allosteric modulator for GABAA receptors. GABAA receptor-mediated inhibition is dependent upon electroneutral cation-chloride transporter KCC2, which mediates neuronal chloride extrusion and its age-dependent increase and postnatally shifts GABAergic signaling from depolarizing to hyperpolarizing. Brain-derived neurotropic factor-tyrosine receptor kinase B activation (BDNF-TrkB activation) after excitotoxic injury recruits downstream targets like PLCγ1, leading to KCC2 hypofunction. Here, the antiseizure efficacy of TrkB agonists LM22A-4, HIOC, and deoxygedunin (DG) on PB-refractory seizures and postischemic TrkB pathway activation was investigated in a mouse model (CD-1, P7) of refractory neonatal seizures. LM, a BDNF loop II mimetic, rescued PB-refractory seizures in a sexually dimorphic manner. Efficacy was associated with a substantial reduction in the postischemic phosphorylation of TrkB at Y816, a site known to mediate postischemic KCC2 hypofunction via PLCγ1 activation. LM rescued ischemia-induced phospho-KCC2-S940 dephosphorylation, preserving its membrane stability. Full TrkB agonists HIOC and DG similarly rescued PB refractoriness. Chemogenetic inactivation of TrkB substantially reduced postischemic neonatal seizure burdens at P7. Sex differences identified in developmental expression profiles of TrkB and KCC2 may underlie the sexually dimorphic efficacy of LM. These results support a potentially novel role for the TrkB receptor in the emergence of age-dependent refractory neonatal seizures.
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Affiliation(s)
- Pavel A Kipnis
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Brennan J Sullivan
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Brandon M Carter
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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