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Jiao D, Xu L, Gu Z, Yan H, Shen D, Gu X. Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies. Neural Regen Res 2025; 20:917-935. [PMID: 38989927 DOI: 10.4103/nrr.nrr-d-23-01444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/18/2024] [Indexed: 07/12/2024] Open
Abstract
Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients' clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.
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Affiliation(s)
- Dian Jiao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Lai Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Zhen Gu
- Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hua Yan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Dingding Shen
- Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaosong Gu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
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Neumann AM, Britsch S. Molecular Genetics of Acquired Temporal Lobe Epilepsy. Biomolecules 2024; 14:669. [PMID: 38927072 PMCID: PMC11202058 DOI: 10.3390/biom14060669] [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: 05/07/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
An epilepsy diagnosis reduces a patient's quality of life tremendously, and it is a fate shared by over 50 million people worldwide. Temporal lobe epilepsy (TLE) is largely considered a nongenetic or acquired form of epilepsy that develops in consequence of neuronal trauma by injury, malformations, inflammation, or a prolonged (febrile) seizure. Although extensive research has been conducted to understand the process of epileptogenesis, a therapeutic approach to stop its manifestation or to reliably cure the disease has yet to be developed. In this review, we briefly summarize the current literature predominately based on data from excitotoxic rodent models on the cellular events proposed to drive epileptogenesis and thoroughly discuss the major molecular pathways involved, with a focus on neurogenesis-related processes and transcription factors. Furthermore, recent investigations emphasized the role of the genetic background for the acquisition of epilepsy, including variants of neurodevelopmental genes. Mutations in associated transcription factors may have the potential to innately increase the vulnerability of the hippocampus to develop epilepsy following an injury-an emerging perspective on the epileptogenic process in acquired forms of epilepsy.
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Affiliation(s)
| | - Stefan Britsch
- Institute of Molecular and Cellular Anatomy, Ulm University, 89081 Ulm, Germany;
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Alcantara-Gonzalez D, Kennedy M, Criscuolo C, Botterill J, Scharfman HE. Increased excitability of dentate gyrus mossy cells occurs early in life in the Tg2576 model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579729. [PMID: 38645244 PMCID: PMC11027210 DOI: 10.1101/2024.02.09.579729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
INTRODUCTION Hyperexcitability in Alzheimer's disease (AD) emerge early and contribute to disease progression. The dentate gyrus (DG) is implicated in hyperexcitability in AD. We hypothesized that mossy cells (MCs), regulators of DG excitability, contribute to early hyperexcitability in AD. Indeed, MCs generate hyperexcitability in epilepsy. METHODS Using the Tg2576 model and WT mice (∼1month-old), we compared MCs electrophysiologically, assessed c-Fos activity marker, Aβ expression and mice performance in a hippocampal-dependent memory task. RESULTS Tg2576 MCs exhibit increased spontaneous excitatory events and decreased inhibitory currents, increasing the charge transfer excitation/inhibition ratio. Tg2576 MC intrinsic excitability was enhanced, and showed higher c-Fos, intracellular Aβ expression, and axon sprouting. Granule cells only showed changes in synaptic properties, without intrinsic changes. The effects occurred before a memory task is affected. DISCUSSION Early electrophysiological and morphological alterations in Tg2576 MCs are consistent with enhanced excitability, suggesting an early role in DG hyperexcitability and AD pathophysiology. HIGHLIGHTS ∘ MCs from 1 month-old Tg2576 mice had increased spontaneous excitatory synaptic input. ∘ Tg2576 MCs had reduced spontaneous inhibitory synaptic input. ∘ Several intrinsic properties were abnormal in Tg2576 MCs. ∘ Tg2576 GCs had enhanced synaptic excitation but no changes in intrinsic properties. ∘ Tg2576 MCs exhibited high c-Fos expression, soluble Aβ and axonal sprouting.
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Kumari S, Brewster AL. Exploring Dendritic and Spine Structural Profiles in Epilepsy: Insights From Human Studies and Experimental Animal Models. Epilepsy Curr 2024; 24:40-46. [PMID: 38327540 PMCID: PMC10846509 DOI: 10.1177/15357597231218603] [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] [Indexed: 02/09/2024] Open
Abstract
Dendrites are tree-like structures with tiny spines specialized to receive excitatory synaptic transmission. Spino-dendritic plasticity, driven by neural activity, underlies the maintenance of neuronal connections crucial for proper circuit function. Abnormalities in dendritic morphology are frequently seen in epilepsy. However, the exact etiology or functional implications are not yet known. Therefore, to better comprehend the structure-function significance of this dendritic pathology in epilepsy, it is necessary to identify the common spino-dendritic disturbances present in both human and experimental models. Here, we describe the dendritic and spine structural profiles found across human refractory epilepsy as well as in animal models of developmental, acquired, and genetic epilepsies.
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Affiliation(s)
- Shikha Kumari
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX, USA
| | - Amy L. Brewster
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX, USA
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Latchney SE, Ruiz Lopez BR, Womble PD, Blandin KJ, Lugo JN. Neuronal deletion of phosphatase and tensin homolog in mice results in spatial dysregulation of adult hippocampal neurogenesis. Front Mol Neurosci 2023; 16:1308066. [PMID: 38130682 PMCID: PMC10733516 DOI: 10.3389/fnmol.2023.1308066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Adult neurogenesis is a persistent phenomenon in mammals that occurs in select brain structures in both healthy and diseased brains. The tumor suppressor gene, phosphatase and tensin homolog deleted on chromosome 10 (Pten) has previously been found to restrict the proliferation of neural stem/progenitor cells (NSPCs) in vivo. In this study, we aimed to provide a comprehensive picture of how conditional deletion of Pten may regulate the genesis of adult NSPCs in the dentate gyrus of the hippocampus and the subventricular zone bordering the lateral ventricles. Using conventional markers and stereology, we quantified multiple stages of neurogenesis, including proliferating cells, immature neurons (neuroblasts), and apoptotic cells in several regions of the dentate gyrus, including the subgranular zone (SGZ), outer granule cell layer (oGCL), molecular layer, and hilus at 4 and 10 weeks of age. Our data demonstrate that conditional deletion of Pten in mice produces successive increases in dentate gyrus proliferating cells and immature neuroblasts, which confirms the known negative roles Pten has on cell proliferation and maturation. Specifically, we observe a significant increase in Ki67+ proliferating cells in the neurogenic SGZ at 4 weeks of age, but not 10 weeks of age. We also observe a delayed increase in neuroblasts at 10 weeks of age. However, our study expands on previous work by providing temporal, subregional, and neurogenesis-stage resolution. Specifically, we found that Pten deletion initially increases cell proliferation in the neurogenic SGZ, but this increase spreads to non-neurogenic dentate gyrus areas, including the hilus, oGCL, and molecular layer, as mice age. We also observed region-specific increases in apoptotic cells in the dentate gyrus hilar region that paralleled the regional increases in Ki67+ cells. Our work is accordant with the literature showing that Pten serves as a negative regulator of dentate gyrus neurogenesis but adds temporal and spatial components to the existing knowledge.
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Affiliation(s)
- Sarah E. Latchney
- Department of Biology, St. Mary’s College of Maryland, St. Mary’s City, MD, United States
| | - Brayan R. Ruiz Lopez
- Department of Biology, St. Mary’s College of Maryland, St. Mary’s City, MD, United States
| | - Paige D. Womble
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Katherine J. Blandin
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Joaquin N. Lugo
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
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Metcalfe M, Steward O. PTEN deletion in spinal pathways via retrograde transduction with AAV-RG enhances forelimb motor recovery after cervical spinal cord injury; Sex differences and late-onset pathophysiologies. Exp Neurol 2023; 370:114551. [PMID: 37778650 DOI: 10.1016/j.expneurol.2023.114551] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/08/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Spinal cord injuries (SCI) cause permanent functional impairments due to interruption of motor and sensory pathways. Regeneration of axons does not occur due to lack of intrinsic growth capacity of adult neurons and extrinsic inhibitory factors, especially at the injury site. However, some regeneration can be achieved via deletion of the phosphatase and tensin homolog (PTEN) in cells of origin of spinal pathways. Here, we deployed an AAV variant that is retrogradely transported (AAV-rg) to deliver gene modifying cargos to the cells of origin of multiple pathways interrupted by SCI, testing whether this promoted recovery of motor function. PTENf/f;RosatdTomato mice and control RosatdTomato mice received injections of different doses (number of genome copies, GCs) of AAV-rg/Cre into the cervical spinal cord at the time of a C5 dorsal hemisection injury. Forelimb grip strength was tested over time using a grip strength meter. PTENf/f;RosatdTomato mice with AAV-rg/Cre (PTEN-deleted) exhibited substantial improvements in forelimb gripping ability in comparison to controls. Of note, there were major sex differences in the extent of recovery, with male mice exhibiting greater recovery than females. However, at around 5-7 weeks post-injury/injection, many mice with SCI and AAV-rg-mediated PTEN deletion began to exhibit pathophysiologies involving excessive scratching of the ears and back of the neck and rigid forward extension of the hindlimbs. These pathophysiologies increased in incidence and severity over time. Our results reveal that although intra-spinal injections of AAV-rg/Cre in PTENf/f;RosatdTomato mice can enhance forelimb motor recovery after SCI, late-developing functional abnormalities occur with the experimental conditions used here. Mechanisms underlying late-developing pathophysiologies remain to be defined.
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Affiliation(s)
- Mariajose Metcalfe
- Reeve-Irvine Research Center University of California Irvine School of Medicine, USA; Department of Anatomy & Neurobiology, University of California Irvine School of Medicine, USA
| | - Oswald Steward
- Reeve-Irvine Research Center University of California Irvine School of Medicine, USA; Department of Anatomy & Neurobiology, University of California Irvine School of Medicine, USA; Department of Neurobiology & Behavior, University of California Irvine, USA; Department of Neurosurgery, University of California Irvine School of Medicine, USA.
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Chen Y, Wu XL, Hu HB, Yang SN, Zhang ZY, Fu GL, Zhang CT, Li ZM, Wu F, Si KW, Ma YB, Ji SF, Zhou JS, Ren XY, Xiao XL, Liu JX. Neuronal MeCP2 in the dentate gyrus regulates mossy fiber sprouting of mice with temporal lobe epilepsy. Neurobiol Dis 2023; 188:106346. [PMID: 37931884 DOI: 10.1016/j.nbd.2023.106346] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/08/2023] Open
Abstract
Sprouting of mossy fibers, one of the most consistent findings in tissue from patients with mesial temporal lobe epilepsy, exhibits several uncommon axonal growth features and has been considered a paradigmatic example of circuit plasticity that occurs in the adult brain. Clarifying the mechanisms responsible may provide new insight into epileptogenesis as well as axon misguidance in the central nervous system. Methyl-CpG-binding protein 2 (MeCP2) binds to methylated genomic DNA to regulate a range of physiological functions implicated in neuronal development and adult synaptic plasticity. However, exploring the potential role of MeCP2 in the documented misguidance of axons in the dentate gyrus has not yet been attempted. In this study, a status epilepticus-induced decrease of neuronal MeCP2 was observed in the dentate gyrus (DG). An essential regulatory role of MeCP2 in the development of functional mossy fiber sprouting (MFS) was confirmed through stereotaxic injection of a recombinant adeno-associated virus (AAV) to up- or down-regulate MeCP2 in the dentate neurons. Chromatin immunoprecipitation sequencing (ChIP-seq) was performed to identify the binding profile of native MeCP2 using micro-dissected dentate tissues. In both dentate tissues and HT22 cell lines, we demonstrated that MeCP2 could act as a transcription repressor on miR-682 with the involvement of the DNA methylation mechanism. Further, we found that miR-682 could bind to mRNA of phosphatase and tensin homolog (PTEN) in a sequence specific manner, thus leading to the suppression of PTEN and excessive activation of mTOR. This study therefore presents a novel epigenetic mechanism by identifying MeCP2/miR-682/PTEN/mTOR as an essential signal pathway in regulating the formation of MFS in the temporal lobe epileptic (TLE) mice. SIGNIFICANCE STATEMENT: Understanding the mechanisms that regulate axon guidance is important for a better comprehension of neural disorders. Sprouting of mossy fibers, one of the most consistent findings in patients with mesial temporal lobe epilepsy, has been considered a paradigmatic example of circuit plasticity in the adult brain. Although abnormal regulation of DNA methylation has been observed in both experimental rodents and humans with epilepsy, the potential role of DNA methylation in this well-documented example of sprouting of dentate axon remains elusive. This study demonstrates an essential role of methyl-CpG-binding protein 2 in the formation of mossy fiber sprouting. The underlying signal pathway has been also identified. The data hence provide new insight into epileptogenesis as well as axon misguidance in the central nervous system.
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Affiliation(s)
- Yu Chen
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China
| | - Xiao-Lin Wu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China
| | - Hai-Bo Hu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China
| | - Shu-Nan Yang
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China
| | - Zi-Yi Zhang
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China
| | - Guan-Ling Fu
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China
| | - Chu-Tong Zhang
- Qide College, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Zi-Meng Li
- Zonglian College, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Feng Wu
- Center of Teaching and Experiment for Medical Postgraduates, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Kai-Wei Si
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Yan-Bing Ma
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China
| | - Sheng-Feng Ji
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China
| | - Jin-Song Zhou
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China
| | - Xiao-Yong Ren
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China
| | - Xin-Li Xiao
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China.
| | - Jian-Xin Liu
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City, 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an City 710061, China.
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Sri Hari A, Banerji R, Liang LP, Fulton RE, Huynh CQ, Fabisiak T, McElroy PB, Roede JR, Patel M. Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability. Redox Biol 2023; 67:102895. [PMID: 37769522 PMCID: PMC10539966 DOI: 10.1016/j.redox.2023.102895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/14/2023] [Accepted: 09/18/2023] [Indexed: 10/02/2023] Open
Abstract
Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.
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Affiliation(s)
- Ashwini Sri Hari
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Rajeswari Banerji
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Li-Ping Liang
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Ruth E Fulton
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Christopher Quoc Huynh
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Timothy Fabisiak
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Pallavi Bhuyan McElroy
- The Janssen Pharmaceutical Companies of Johnson & Johnson, Greater Philadelphia Area, Horsham, PA, 19044, USA
| | - James R Roede
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA.
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Chen L, Xu Y, Cheng H, Li Z, Lai N, Li M, Ruan Y, Zheng Y, Fei F, Xu C, Ma J, Wang S, Gu Y, Han F, Chen Z, Wang Y. Adult-born neurons in critical period maintain hippocampal seizures via local aberrant excitatory circuits. Signal Transduct Target Ther 2023; 8:225. [PMID: 37280192 DOI: 10.1038/s41392-023-01433-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 03/15/2023] [Accepted: 04/06/2023] [Indexed: 06/08/2023] Open
Abstract
Temporal lobe epilepsy (TLE), one common type of medically refractory epilepsy, is accompanied with altered adult-born dentate granule cells (abDGCs). However, the causal role of abDGCs in recurrent seizures of TLE is not fully understood. Here, taking advantage of optogenetic and chemogenetic tools to selectively manipulate abDGCs in a reversible manner, combined with Ca2+ fiber photometry, trans-synaptic viral tracing, in vivo/vitro electrophysiology approaches, we aimed to test the role of abDGCs born at different period of epileptogenic insult in later recurrent seizures in mouse TLE models. We found that abDGCs were functionally inhibited during recurrent seizures. Optogenetic activation of abDGCs significantly extended, while inhibition curtailed, the seizure duration. This seizure-modulating effect was attributed to specific abDGCs born at a critical early phase after kindled status, which experienced specific type of circuit re-organization. Further, abDGCs extended seizure duration via local excitatory circuit with early-born granule cells (ebDGCs). Repeated modulation of "abDGC-ebDGC" circuit may easily induce a change of synaptic plasticity, and achieve long-term anti-seizure effects in both kindling and kainic acid-induced TLE models. Together, we demonstrate that abDGCs born at a critical period of epileptogenic insult maintain seizure duration via local aberrant excitatory circuits, and inactivation of these aberrant circuits can long-termly alleviate severity of seizures. This provides a deeper and more comprehensive understanding of the potential pathological changes of abDGCs circuit and may be helpful for the precise treatment in TLE.
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Affiliation(s)
- Liying Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yingwei Xu
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Heming Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhongxia Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
- Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Menghan Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yeping Ruan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yang Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Fan Fei
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jiao Ma
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yan Gu
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Feng Han
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
| | - Yi Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
- Zhejiang Rehabilitation Medical Center Department, The Third Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China.
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10
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Yonan JM, Steward O. Vector-mediated PTEN deletion in the adult dentate gyrus initiates new growth of granule cell bodies and dendrites and expansion of mossy fiber terminal fields that continues for months. Neurobiol Dis 2023:106190. [PMID: 37290578 DOI: 10.1016/j.nbd.2023.106190] [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: 02/27/2023] [Revised: 05/20/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023] Open
Abstract
Embryonic and early postnatal deletion of the gene phosphatase and tensin homolog (PTEN) results in neuronal hypertrophy, formation of aberrant neural networks and spontaneous seizures. Our previous studies document that deletion of PTEN in mature neurons also causes growth of cortical neuron cell bodies and dendrites, but it is unknown how this growth alters connectivity in mature circuits. Here, we explore consequences of deleting PTEN in a focal area of the dentate gyrus in adult male and female mice. PTEN deletion was accomplished by injecting AAV-Cre unilaterally into the dentate gyrus of double transgenic mice with lox-P sites flanking exon 5 of the PTEN gene and stop/flox tdTomato in the Rosa locus (PTENf/f/RosatdTomato). Focal deletion led to progressive increases in the size of the dentate gyrus at the injection site, enlargement of granule cell bodies, and increases in dendritic length and caliber. Quantitative analysis of dendrites by Golgi staining revealed dramatic increases in spine numbers throughout the proximo-distal extent of the dendritic tree, suggesting that dendritic growth is sufficient to induce new synapse formation by input neurons with intact PTEN expression. Tract tracing of input pathways to the dentate gyrus from the ipsilateral entorhinal cortex and commissural/associational system revealed that laminar specificity of termination of inputs is maintained. Mossy fiber axons from PTEN-deleted granule cells expanded their terminal field in CA3 where PTEN expression was intact and supra-granular mossy fibers developed in some mice. These findings document that persistent activation of mTOR via PTEN deletion in fully mature neurons re-initiates a state of robust cell-intrinsic growth, upending connectional homeostasis in fully mature hippocampal circuits.
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Affiliation(s)
- Jennifer M Yonan
- Reeve-Irvine Research Center, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Department of Anatomy & Neurobiology, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America
| | - Oswald Steward
- Reeve-Irvine Research Center, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Department of Anatomy & Neurobiology, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Department of Neurobiology & Behavior, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Department of Neurosurgery, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Center for the Neurobiology of Learning and Memory, Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America; Gillespie Neuroscience Research Facility, University of California at Irvine, 837 Health Sciences Rd., Irvine, CA 92697, United States of America.
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11
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Geribaldi-Doldán N, Carrascal L, Pérez-García P, Oliva-Montero JM, Pardillo-Díaz R, Domínguez-García S, Bernal-Utrera C, Gómez-Oliva R, Martínez-Ortega S, Verástegui C, Nunez-Abades P, Castro C. Migratory Response of Cells in Neurogenic Niches to Neuronal Death: The Onset of Harmonic Repair? Int J Mol Sci 2023; 24:ijms24076587. [PMID: 37047560 PMCID: PMC10095545 DOI: 10.3390/ijms24076587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
Harmonic mechanisms orchestrate neurogenesis in the healthy brain within specific neurogenic niches, which generate neurons from neural stem cells as a homeostatic mechanism. These newly generated neurons integrate into existing neuronal circuits to participate in different brain tasks. Despite the mechanisms that protect the mammalian brain, this organ is susceptible to many different types of damage that result in the loss of neuronal tissue and therefore in alterations in the functionality of the affected regions. Nevertheless, the mammalian brain has developed mechanisms to respond to these injuries, potentiating its capacity to generate new neurons from neural stem cells and altering the homeostatic processes that occur in neurogenic niches. These alterations may lead to the generation of new neurons within the damaged brain regions. Notwithstanding, the activation of these repair mechanisms, regeneration of neuronal tissue within brain injuries does not naturally occur. In this review, we discuss how the different neurogenic niches respond to different types of brain injuries, focusing on the capacity of the progenitors generated in these niches to migrate to the injured regions and activate repair mechanisms. We conclude that the search for pharmacological drugs that stimulate the migration of newly generated neurons to brain injuries may result in the development of therapies to repair the damaged brain tissue.
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Affiliation(s)
- Noelia Geribaldi-Doldán
- Departamento de Anatomía y Embriología Humanas, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
| | - Livia Carrascal
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Patricia Pérez-García
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
| | - José M. Oliva-Montero
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
| | - Ricardo Pardillo-Díaz
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
| | - Samuel Domínguez-García
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
- Department of Neuroscience, Karolinska Institutet, Biomedicum, 17177 Stockholm, Sweden
| | - Carlos Bernal-Utrera
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Fisioterapia, Facultad de Enfermería, Fisioterapia y Podología, Universidad de Sevilla, 41009 Sevilla, Spain
| | - Ricardo Gómez-Oliva
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
| | - Sergio Martínez-Ortega
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
| | - Cristina Verástegui
- Departamento de Anatomía y Embriología Humanas, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
| | - Pedro Nunez-Abades
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Carmen Castro
- Instituto de Investigación e Innovación Biomédica de Cádiz (INiBICA), 11009 Cádiz, Spain
- Departamento de Biomedicina, Biotecnología y Salud Pública, Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, 11003 Cádiz, Spain
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12
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Lafourcade CA, Sparks FT, Bordey A, Wyneken U, Mohammadi MH. Cannabinoid regulation of neurons in the dentate gyrus during epileptogenesis: Role of CB1R-associated proteins and downstream pathways. Epilepsia 2023. [PMID: 36869624 DOI: 10.1111/epi.17569] [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: 10/11/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/05/2023]
Abstract
The hippocampal formation plays a central role in the development of temporal lobe epilepsy (TLE), a disease characterized by recurrent, unprovoked epileptic discharges. TLE is a neurologic disorder characterized by acute long-lasting seizures (i.e., abnormal electrical activity in the brain) or seizures that occur in close proximity without recovery, typically after a brain injury or status epilepticus. After status epilepticus, epileptogenic hyperexcitability develops gradually over the following months to years, resulting in the emergence of chronic, recurrent seizures. Acting as a filter or gate, the hippocampal dentate gyrus (DG) normally prevents excessive excitation from propagating through the hippocampus, and is considered a critical region in the progression of epileptogenesis in pathological conditions. Importantly, lipid-derived endogenous cannabinoids (endocannabinoids), which are produced on demand as retrograde messengers, are central regulators of neuronal activity in the DG circuit. In this review, we summarize recent findings concerning the role of the DG in controlling hyperexcitability and propose how DG regulation by cannabinoids (CBs) could provide avenues for therapeutic interventions. We also highlight possible pathways and manipulations that could be relevant for the control of hyperexcitation. The use of CB compounds to treat epilepsies is controversial, as anecdotal evidence is not always validated by clinical trials. Recent publications shed light on the importance of the DG as a region regulating incoming hippocampal excitability during epileptogenesis. We review recent findings concerning the modulation of the hippocampal DG circuitry by CBs and discuss putative underlying pathways. A better understanding of the mechanisms by which CBs exert their action during seizures may be useful to improve therapies.
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Affiliation(s)
- Carlos A Lafourcade
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, China
| | - Fraser T Sparks
- Department of Neuroscience, Columbia University, New York, New York, USA.,Current: Regeneron Pharmaceuticals, Tarrytown, New York, USA
| | - Angelique Bordey
- Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ursula Wyneken
- Centro de Investigación e Innovación Biomédica, Laboratorio de Neurociencias, Universidad de Los Andes, Santiago, Chile.,Center of Interventional Medicine for Precision and Advanced Cellular Therapy, Santiago, Chile
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13
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The Dialogue Between Neuroinflammation and Adult Neurogenesis: Mechanisms Involved and Alterations in Neurological Diseases. Mol Neurobiol 2023; 60:923-959. [PMID: 36383328 DOI: 10.1007/s12035-022-03102-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/23/2022] [Indexed: 11/18/2022]
Abstract
Adult neurogenesis occurs mainly in the subgranular zone of the hippocampal dentate gyrus and the subventricular zone of the lateral ventricles. Evidence supports the critical role of adult neurogenesis in various conditions, including cognitive dysfunction, Alzheimer's disease (AD), and Parkinson's disease (PD). Several factors can alter adult neurogenesis, including genetic, epigenetic, age, physical activity, diet, sleep status, sex hormones, and central nervous system (CNS) disorders, exerting either pro-neurogenic or anti-neurogenic effects. Compelling evidence suggests that any insult or injury to the CNS, such as traumatic brain injury (TBI), infectious diseases, or neurodegenerative disorders, can provoke an inflammatory response in the CNS. This inflammation could either promote or inhibit neurogenesis, depending on various factors, such as chronicity and severity of the inflammation and underlying neurological disorders. Notably, neuroinflammation, driven by different immune components such as activated glia, cytokines, chemokines, and reactive oxygen species, can regulate every step of adult neurogenesis, including cell proliferation, differentiation, migration, survival of newborn neurons, maturation, synaptogenesis, and neuritogenesis. Therefore, this review aims to present recent findings regarding the effects of various components of the immune system on adult neurogenesis and to provide a better understanding of the role of neuroinflammation and neurogenesis in the context of neurological disorders, including AD, PD, ischemic stroke (IS), seizure/epilepsy, TBI, sleep deprivation, cognitive impairment, and anxiety- and depressive-like behaviors. For each disorder, some of the most recent therapeutic candidates, such as curcumin, ginseng, astragaloside, boswellic acids, andrographolide, caffeine, royal jelly, estrogen, metformin, and minocycline, have been discussed based on the available preclinical and clinical evidence.
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14
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Dusing M, LaSarge CL, White A, Jerow LG, Gross C, Danzer SC. Neurovascular Development in Pten and Tsc2 Mouse Mutants. eNeuro 2023; 10:ENEURO.0340-22.2023. [PMID: 36759189 PMCID: PMC9953070 DOI: 10.1523/eneuro.0340-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Hyperactivation of the mechanistic target of rapamycin (mTOR) signaling pathway is linked to more than a dozen neurologic diseases, causing a range of pathologies, including excess neuronal growth, disrupted neuronal migration, cortical dysplasia, epilepsy and autism. The mTOR pathway also regulates angiogenesis. For the present study, therefore, we queried whether loss of Pten or Tsc2, both mTOR negative regulators, alters brain vasculature in three mouse models: one with Pten loss restricted to hippocampal dentate granule cells [DGC-Pten knock-outs (KOs)], a second with widespread Pten loss from excitatory forebrain neurons (FB-Pten KOs) and a third with focal loss of Tsc2 from cortical excitatory neurons (f-Tsc2 KOs). Total hippocampal vessel length and volume per dentate gyrus were dramatically increased in DGC-Pten knock-outs. DGC-Pten knock-outs had larger dentate gyri overall, however, and when normalized to these larger structures, vessel density was preserved. In addition, tests of blood-brain barrier integrity did not reveal increased permeability. FB-Pten KOs recapitulated the findings in the more restricted DGC-Pten KOs, with increased vessel area, but preserved vessel density. FB-Pten KOs did, however, exhibit elevated levels of the angiogenic factor VegfA. In contrast to findings with Pten, focal loss of Tsc2 from cortical excitatory neurons produced a localized increase in vessel density. Together, these studies demonstrate that hypervascularization is not a consistent feature of mTOR hyperactivation models and suggest that loss of different mTOR pathway regulatory genes exert distinct effects on angiogenesis.
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Affiliation(s)
- Mary Dusing
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Candi L LaSarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Angela White
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Lilian G Jerow
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Christina Gross
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
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15
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mTORC2 Inhibition Improves Morphological Effects of PTEN Loss, But Does Not Correct Synaptic Dysfunction or Prevent Seizures. J Neurosci 2023; 43:827-845. [PMID: 36526374 PMCID: PMC9899090 DOI: 10.1523/jneurosci.1354-22.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/29/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Hyperactivation of PI3K/PTEN-mTOR signaling during neural development is associated with focal cortical dysplasia (FCD), autism, and epilepsy. mTOR can signal through two major hubs, mTORC1 and mTORC2, both of which are hyperactive following PTEN loss of function (LOF). Here, we tested the hypothesis that genetic inactivation of the mTORC2 complex via deletion of Rictor is sufficient to rescue morphologic and electrophysiological abnormalities in the dentate gyrus caused by PTEN loss, as well as generalized seizures. An established, early postnatal mouse model of PTEN loss in male and female mice showed spontaneous seizures that were not prevented by mTORC2 inactivation. This lack of rescue occurred despite the normalization or amelioration of many morphologic and electrophysiological phenotypes. However, increased excitatory connectivity proximal to dentate gyrus granule neuron somas was not normalized by mTORC2 inactivation. Further studies demonstrated that, although mTORC2 inactivation largely rescued the dendritic arbor overgrowth caused by PTEN LOF, it increased synaptic strength and caused additional impairments of presynaptic function. These results suggest that a constrained increase in excitatory connectivity and co-occurring synaptic dysfunction is sufficient to generate seizures downstream of PTEN LOF, even in the absence of characteristic changes in morphologic properties.SIGNIFICANCE STATEMENT Homozygous deletion of the Pten gene in neuronal subpopulations in the mouse serves as a valuable model of epilepsy caused by mTOR hyperactivation. To better understand the physiological mechanisms downstream of Pten loss that cause epilepsy, as well as the therapeutic potential of targeted gene therapies, we tested whether genetic inactivation of the mTORC2 complex could improve the cellular, synaptic, and in vivo effects of Pten loss in the dentate gyrus. We found that mTORC2 inhibition improved or rescued all morphologic effects of Pten loss in the dentate gyrus, but synaptic changes and seizures persisted. These data suggest that synaptic dysfunction can drive epilepsy caused by hyperactivation of PI3K/PTEN-mTOR, and that future therapies should focus on this mechanistic link.
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16
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Kasahara Y, Nakashima H, Nakashima K. Seizure-induced hilar ectopic granule cells in the adult dentate gyrus. Front Neurosci 2023; 17:1150283. [PMID: 36937666 PMCID: PMC10017466 DOI: 10.3389/fnins.2023.1150283] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Epilepsy is a chronic neurological disorder characterized by hypersynchronous spontaneous recurrent seizures, and affects approximately 50 million people worldwide. Cumulative evidence has revealed that epileptogenic insult temporarily increases neurogenesis in the hippocampus; however, a fraction of the newly generated neurons are integrated abnormally into the existing neural circuits. The abnormal neurogenesis, including ectopic localization of newborn neurons in the hilus, formation of abnormal basal dendrites, and disorganization of the apical dendrites, rewires hippocampal neural networks and leads to the development of spontaneous seizures. The central roles of hilar ectopic granule cells in regulating hippocampal excitability have been suggested. In this review, we introduce recent findings about the migration of newborn granule cells to the dentate hilus after seizures and the roles of seizure-induced ectopic granule cells in the epileptic brain. In addition, we delineate possible intrinsic and extrinsic mechanisms underlying this abnormality. Finally, we suggest that the regulation of seizure-induced ectopic cells can be a promising target for epilepsy therapy and provide perspectives on future research directions.
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17
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Hu YY, Yang G, Liang XS, Ding XS, Xu DE, Li Z, Ma QH, Chen R, Sun YY. Transcranial low-intensity ultrasound stimulation for treating central nervous system disorders: A promising therapeutic application. Front Neurol 2023; 14:1117188. [PMID: 36970512 PMCID: PMC10030814 DOI: 10.3389/fneur.2023.1117188] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 02/10/2023] [Indexed: 03/29/2023] Open
Abstract
Transcranial ultrasound stimulation is a neurostimulation technique that has gradually attracted the attention of researchers, especially as a potential therapy for neurological disorders, because of its high spatial resolution, its good penetration depth, and its non-invasiveness. Ultrasound can be categorized as high-intensity and low-intensity based on the intensity of its acoustic wave. High-intensity ultrasound can be used for thermal ablation by taking advantage of its high-energy characteristics. Low-intensity ultrasound, which produces low energy, can be used as a means to regulate the nervous system. The present review describes the current status of research on low-intensity transcranial ultrasound stimulation (LITUS) in the treatment of neurological disorders, such as epilepsy, essential tremor, depression, Parkinson's disease (PD), and Alzheimer's disease (AD). This review summarizes preclinical and clinical studies using LITUS to treat the aforementioned neurological disorders and discusses their underlying mechanisms.
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Affiliation(s)
- Yun-Yun Hu
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
| | - Gang Yang
- Lab Center, Medical College of Soochow University, Suzhou, China
| | - Xue-Song Liang
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
- Second Clinical College, Dalian Medical University, Dalian, Liaoning, China
| | - Xuan-Si Ding
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
| | - De-En Xu
- Wuxi No. 2 People's Hospital, Wuxi, Jiangsu, China
| | - Zhe Li
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Sleep Medicine Center, Suzhou Guangji Hospital, The Affiliated Guangji Hospital of Soochow University, Suzhou, China
| | - Quan-Hong Ma
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
- Quan-Hong Ma
| | - Rui Chen
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Rui Chen
| | - Yan-Yun Sun
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China
- Yan-Yun Sun
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18
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Aloi MS, Thompson SJ, Quartapella N, Noebels JL. Loss of functional System x-c uncouples aberrant postnatal neurogenesis from epileptogenesis in the hippocampus of Kcna1-KO mice. Cell Rep 2022; 41:111696. [PMID: 36417872 PMCID: PMC9753929 DOI: 10.1016/j.celrep.2022.111696] [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: 03/25/2022] [Revised: 09/29/2022] [Accepted: 10/28/2022] [Indexed: 11/23/2022] Open
Abstract
Mutations in Kv1.1 (Kcna1) voltage-gated potassium channels in humans and mice generate network hyperexcitability, enhancing aberrant postnatal neurogenesis in the dentate subgranular zone, resulting in epilepsy and hippocampal hypertrophy. While Kcna1 loss stimulates proliferation of progenitor cell subpopulations, the identity of extrinsic molecular triggers linking network hyperexcitability to aberrant postnatal neurogenesis remains incomplete. System x-c (Sxc) is an inducible glutamate/cysteine antiporter that regulates extracellular glutamate. Here, we find that the functional unit of Sxc, xCT (Slc7a11), is upregulated in regions of Kcna1 knockout (KO) hippocampus, suggesting a contribution to both hyperplasia and epilepsy. However, Slc7a11 KO suppressed and rescued hippocampal enlargement without altering seizure severity in Kcna1-Slc7a11-KO mice. Microglial activation, but not astrocytosis, was also reduced. Our study identifies Sxc-mediated glutamate homeostasis as an essential non-synaptic trigger coupling aberrant postnatal neurogenesis and neuroimmune crosstalk, revealing that neurogenesis and epileptogenesis in the dentate gyrus are not mutually contingent events.
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Affiliation(s)
- Macarena S Aloi
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA; Blue Bird Circle Developmental Neurogenetics Laboratory, Houston, TX, USA
| | - Samantha J Thompson
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA; Blue Bird Circle Developmental Neurogenetics Laboratory, Houston, TX, USA
| | - Nicholas Quartapella
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA; Blue Bird Circle Developmental Neurogenetics Laboratory, Houston, TX, USA; Department of BioSciences, Rice University, Houston, TX, USA
| | - Jeffrey L Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA; Blue Bird Circle Developmental Neurogenetics Laboratory, Houston, TX, USA.
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19
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Shao Y, Ge Q, Yang J, Wang M, Zhou Y, Guo JX, Zhu M, Shi J, Hu Y, Shen L, Chen Z, Li XM, Zhu JM, Zhang J, Duan S, Chen J. Pathological Networks Involving Dysmorphic Neurons in Type II Focal Cortical Dysplasia. Neurosci Bull 2022; 38:1007-1024. [PMID: 35235180 PMCID: PMC9468210 DOI: 10.1007/s12264-022-00828-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/24/2021] [Indexed: 10/19/2022] Open
Abstract
Focal cortical dysplasia (FCD) is one of the most common causes of drug-resistant epilepsy. Dysmorphic neurons are the major histopathological feature of type II FCD, but their role in seizure genesis in FCD is unclear. Here we performed whole-cell patch-clamp recording and morphological reconstruction of cortical principal neurons in postsurgical brain tissue from drug-resistant epilepsy patients. Quantitative analyses revealed distinct morphological and electrophysiological characteristics of the upper layer dysmorphic neurons in type II FCD, including an enlarged soma, aberrant dendritic arbors, increased current injection for rheobase action potential firing, and reduced action potential firing frequency. Intriguingly, the upper layer dysmorphic neurons received decreased glutamatergic and increased GABAergic synaptic inputs that were coupled with upregulation of the Na+-K+-Cl- cotransporter. In addition, we found a depolarizing shift of the GABA reversal potential in the CamKII-cre::PTENflox/flox mouse model of drug-resistant epilepsy, suggesting that enhanced GABAergic inputs might depolarize dysmorphic neurons. Thus, imbalance of synaptic excitation and inhibition of dysmorphic neurons may contribute to seizure genesis in type II FCD.
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Affiliation(s)
- Yijie Shao
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
- Department of Neurosurgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Qianqian Ge
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jiachao Yang
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Mi Wang
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yu Zhou
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jin-Xin Guo
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China
| | - Mengyue Zhu
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jiachen Shi
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yiqi Hu
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Li Shen
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China
- Department of Orthopedic Surgery, School of Medicine, the Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China
- Hangzhou Innovation Center, Zhejiang University, Hangzhou, 310058, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China
| | - Xiao-Ming Li
- Center for Neuroscience and Department of Neurology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Center for Brain Science and Brain-Inspired Intelligence, Joint Institute for Genetics and Genome Medicine between, Guangdong Hong Kong Macao Greater Bay Area, Zhejiang University and the University of Toronto, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jun-Ming Zhu
- Department of Neurosurgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Jianmin Zhang
- Department of Neurosurgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
| | - Shumin Duan
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Jiadong Chen
- Center for Neuroscience and Department of Neurosurgery of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
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20
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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: 7] [Impact Index Per Article: 3.5] [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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21
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Hills KE, Kostarelos K, Wykes RC. Converging Mechanisms of Epileptogenesis and Their Insight in Glioblastoma. Front Mol Neurosci 2022; 15:903115. [PMID: 35832394 PMCID: PMC9271928 DOI: 10.3389/fnmol.2022.903115] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/25/2022] [Indexed: 12/15/2022] Open
Abstract
Glioblastoma (GBM) is the most common and advanced form of primary malignant tumor occurring in the adult central nervous system, and it is frequently associated with epilepsy, a debilitating comorbidity. Seizures are observed both pre- and post-surgical resection, indicating that several pathophysiological mechanisms are shared but also prompting questions about how the process of epileptogenesis evolves throughout GBM progression. Molecular mutations commonly seen in primary GBM, i.e., in PTEN and p53, and their associated downstream effects are known to influence seizure likelihood. Similarly, various intratumoral mechanisms, such as GBM-induced blood-brain barrier breakdown and glioma-immune cell interactions within the tumor microenvironment are also cited as contributing to network hyperexcitability. Substantial alterations to peri-tumoral glutamate and chloride transporter expressions, as well as widespread dysregulation of GABAergic signaling are known to confer increased epileptogenicity and excitotoxicity. The abnormal characteristics of GBM alter neuronal network function to result in metabolically vulnerable and hyperexcitable peri-tumoral tissue, properties the tumor then exploits to favor its own growth even post-resection. It is evident that there is a complex, dynamic interplay between GBM and epilepsy that promotes the progression of both pathologies. This interaction is only more complicated by the concomitant presence of spreading depolarization (SD). The spontaneous, high-frequency nature of GBM-associated epileptiform activity and SD-associated direct current (DC) shifts require technologies capable of recording brain signals over a wide bandwidth, presenting major challenges for comprehensive electrophysiological investigations. This review will initially provide a detailed examination of the underlying mechanisms that promote network hyperexcitability in GBM. We will then discuss how an investigation of these pathologies from a network level, and utilization of novel electrophysiological tools, will yield a more-effective, clinically-relevant understanding of GBM-related epileptogenesis. Further to this, we will evaluate the clinical relevance of current preclinical research and consider how future therapeutic advancements may impact the bidirectional relationship between GBM, SDs, and seizures.
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Affiliation(s)
- Kate E. Hills
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Kostas Kostarelos
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Catalan Institute for Nanoscience and Nanotechnology (ICN2), Edifici ICN2, Campus UAB, Barcelona, Spain
| | - Robert C. Wykes
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- *Correspondence: Robert C. Wykes
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22
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Chaudry S, Vasudevan N. mTOR-Dependent Spine Dynamics in Autism. Front Mol Neurosci 2022; 15:877609. [PMID: 35782388 PMCID: PMC9241970 DOI: 10.3389/fnmol.2022.877609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022] Open
Abstract
Autism Spectrum Conditions (ASC) are a group of neurodevelopmental disorders characterized by deficits in social communication and interaction as well as repetitive behaviors and restricted range of interests. ASC are complex genetic disorders with moderate to high heritability, and associated with atypical patterns of neural connectivity. Many of the genes implicated in ASC are involved in dendritic spine pruning and spine development, both of which can be mediated by the mammalian target of rapamycin (mTOR) signaling pathway. Consistent with this idea, human postmortem studies have shown increased spine density in ASC compared to controls suggesting that the balance between autophagy and spinogenesis is altered in ASC. However, murine models of ASC have shown inconsistent results for spine morphology, which may underlie functional connectivity. This review seeks to establish the relevance of changes in dendritic spines in ASC using data gathered from rodent models. Using a literature survey, we identify 20 genes that are linked to dendritic spine pruning or development in rodents that are also strongly implicated in ASC in humans. Furthermore, we show that all 20 genes are linked to the mTOR pathway and propose that the mTOR pathway regulating spine dynamics is a potential mechanism underlying the ASC signaling pathway in ASC. We show here that the direction of change in spine density was mostly correlated to the upstream positive or negative regulation of the mTOR pathway and most rodent models of mutant mTOR regulators show increases in immature spines, based on morphological analyses. We further explore the idea that these mutations in these genes result in aberrant social behavior in rodent models that is due to these altered spine dynamics. This review should therefore pave the way for further research on the specific genes outlined, their effect on spine morphology or density with an emphasis on understanding the functional role of these changes in ASC.
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23
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Victor TR, Hage Z, Tsirka SE. Prophylactic administration of cannabidiol reduces microglial inflammatory response to kainate-induced seizures and neurogenesis. Neuroscience 2022; 500:1-11. [PMID: 35700815 DOI: 10.1016/j.neuroscience.2022.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 11/26/2022]
Abstract
Microglia, the dynamic innate immune cells of the central nervous system, become activated in epilepsy. The process of microglial activation in epilepsy results in the creation of an inflammatory environment around the site of seizure onset, which contributes to the epileptogenic process and epilepsy progression. Cannabidiol (CBD) has been effective for use as an adjunctive treatment for two severe pediatric seizure disorders. Newly recognized as an Food and Drug Administration (FDA)-approved drug treatment in epilepsy, it has gained in popularity primarily for pain management. Although CBD is readily available in stores and online retailers, its mechanism of action and specifically its effects on microglia and their functions are yet fully understood. In this study, we examine the effects of commercially available CBD on microglia inflammatory activation and neurogenic response, in the presence and absence of seizures. We use systemic administration of kainate to elicit seizures in mice, which are assessed behaviorally. Artisanal CBD is given in different modes of administration and timing to dissect its effect on seizure intensity, microglial activation and aberrant seizure-related neurogenesis. CBD significantly dampens microglial migration and accumulation to the hippocampus. While long term artisanal CBD use does not prevent or lessen seizure severity, CBD is a promising adjunctive partner for its ability to depress epileptogenic processes. These studies indicate that artisanal CBD is beneficial as it both decreases inflammation in the CNS and reduces the number of ectopic neurons deposited in the hippocampal area post seizure.
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Affiliation(s)
- Tanya R Victor
- Molecular and Cellular Pharmacology Graduate Program, Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794, United States
| | - Zachary Hage
- Molecular and Cellular Pharmacology Graduate Program, Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794, United States
| | - Stella E Tsirka
- Molecular and Cellular Pharmacology Graduate Program, Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794, United States.
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24
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Impact of Raptor and Rictor Deletion on Hippocampal Pathology Following Status Epilepticus. J Mol Neurosci 2022; 72:1243-1258. [PMID: 35618880 PMCID: PMC9571976 DOI: 10.1007/s12031-022-02030-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
Abstract
Neuronal hyperactivation of the mTOR signaling pathway may play a role in driving the pathological sequelae that follow status epilepticus. Animal studies using pharmacological tools provide support for this hypothesis, however, systemic inhibition of mTOR-a growth pathway active in every mammalian cell-limits conclusions on cell type specificity. To circumvent the limitations of pharmacological approaches, we developed a viral/genetic strategy to delete Raptor or Rictor, inhibiting mTORC1 or mTORC2, respectively, from excitatory hippocampal neurons after status epilepticus in mice. Raptor or Rictor was deleted from roughly 25% of hippocampal granule cells, with variable involvement of other hippocampal neurons, after pilocarpine status epilepticus. Status epilepticus induced the expected loss of hilar neurons, sprouting of granule cell mossy fiber axons and reduced c-Fos activation. Gene deletion did not prevent these changes, although Raptor loss reduced the density of c-Fos-positive granule cells overall relative to Rictor groups. Findings demonstrate that mTOR signaling can be effectively modulated with this approach and further reveal that blocking mTOR signaling in a minority (25%) of granule cells is not sufficient to alter key measures of status epilepticus-induced pathology. The approach is suitable for producing higher deletion rates, and altering the timing of deletion, which may lead to different outcomes.
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25
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Sathyanarayana SH, Saunders JA, Slaughter J, Tariq K, Chakrabarti R, Sadanandappa MK, Luikart BW, Bosco G. Pten heterozygosity restores neuronal morphology in fragile X syndrome mice. Proc Natl Acad Sci U S A 2022; 119:e2109448119. [PMID: 35394871 PMCID: PMC9169627 DOI: 10.1073/pnas.2109448119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 02/11/2022] [Indexed: 11/30/2022] Open
Abstract
Genetic studies of hippocampal granule neuron development have been used to elucidate cellular functions of Pten and Fmr1. While mutations in each gene cause neurodevelopmental disorders such as autism and fragile X syndrome, how Pten and Fmr1 function alone or together during normal development is not known. Moreover, Pten mRNA is bound by the fragile X mental retardation protein (FMRP) RNA binding protein, but how this physical interaction impinges on phosphatase and tensin homolog protein (PTEN) expression is not known. To understand the interaction of PTEN and FMRP, we investigated the dentate gyrus granule neuron development in Pten and Fmr1 knockout (KO) mice. Interestingly, heterozygosity of Pten restored Fmr1 KO cellular phenotypes, including dendritic arborization, and spine density, while PTEN protein expression was significantly increased in Fmr1 KO animals. However, complete deletion of both Pten and Fmr1 resulted in a dramatic increase in dendritic length, spine density, and spine length. In addition, overexpression of PTEN in Fmr1 KO Pten heterozygous background reduced dendritic length, arborization, spine density, and spine length including pS6 levels. Our findings suggest that PTEN levels are negatively regulated by FMRP, and some Fmr1 KO phenotypes are caused by dysregulation of PTEN protein. These observations provide evidence for the genetic interaction of PTEN and FMRP and a possible mechanistic basis for the pathogenesis of Fmr1-related fragile X neurodevelopmental disorders.
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Affiliation(s)
| | - Jasmine A. Saunders
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Jacob Slaughter
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Kamran Tariq
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cellular Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Madhumala K. Sadanandappa
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Bryan W. Luikart
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Giovanni Bosco
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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26
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Ammothumkandy A, Ravina K, Wolseley V, Tartt AN, Yu PN, Corona L, Zhang N, Nune G, Kalayjian L, Mann JJ, Rosoklija GB, Arango V, Dwork AJ, Lee B, Smith JAD, Song D, Berger TW, Heck C, Chow RH, Boldrini M, Liu CY, Russin JJ, Bonaguidi MA. Altered adult neurogenesis and gliogenesis in patients with mesial temporal lobe epilepsy. Nat Neurosci 2022; 25:493-503. [PMID: 35383330 PMCID: PMC9097543 DOI: 10.1038/s41593-022-01044-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/01/2022] [Indexed: 01/19/2023]
Abstract
The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.
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Affiliation(s)
- Aswathy Ammothumkandy
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Kristine Ravina
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Victoria Wolseley
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Alexandria N Tartt
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA
| | - Pen-Ning Yu
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Luis Corona
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Naibo Zhang
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - George Nune
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Laura Kalayjian
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - J. John Mann
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA,Department of Psychiatry, Columbia University, New York, NY 10032, USA
| | - Gorazd B. Rosoklija
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA,Department of Psychiatry, Columbia University, New York, NY 10032, USA,Macedonian Academy of Sciences & Arts, Skopje 1000, Republic of Macedonia
| | - Victoria Arango
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA,Department of Psychiatry, Columbia University, New York, NY 10032, USA
| | - Andrew J. Dwork
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA,Department of Psychiatry, Columbia University, New York, NY 10032, USA,Macedonian Academy of Sciences & Arts, Skopje 1000, Republic of Macedonia,Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Brian Lee
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jason A D Smith
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Dong Song
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Theodore W Berger
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Christianne Heck
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Robert H Chow
- Department of Physiology & Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Maura Boldrini
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY 10032, USA,Department of Psychiatry, Columbia University, New York, NY 10032, USA
| | - Charles Y Liu
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.,Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Jonathan J Russin
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Michael A Bonaguidi
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.,Department of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.,Department of Biochemistry and Molecular Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.,Corresponding author.
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27
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Li MX, Weng JW, Ho ES, Chow SF, Tsang CK. Brain delivering RNA-based therapeutic strategies by targeting mTOR pathway for axon regeneration after central nervous system injury. Neural Regen Res 2022; 17:2157-2165. [PMID: 35259823 PMCID: PMC9083176 DOI: 10.4103/1673-5374.335830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Injuries to the central nervous system (CNS) such as stroke, brain, and spinal cord trauma often result in permanent disabilities because adult CNS neurons only exhibit limited axon regeneration. The brain has a surprising intrinsic capability of recovering itself after injury. However, the hostile extrinsic microenvironment significantly hinders axon regeneration. Recent advances have indicated that the inactivation of intrinsic regenerative pathways plays a pivotal role in the failure of most adult CNS neuronal regeneration. Particularly, substantial evidence has convincingly demonstrated that the mechanistic target of rapamycin (mTOR) signaling is one of the most crucial intrinsic regenerative pathways that drive axonal regeneration and sprouting in various CNS injuries. In this review, we will discuss the recent findings and highlight the critical roles of mTOR pathway in axon regeneration in different types of CNS injury. Importantly, we will demonstrate that the reactivation of this regenerative pathway can be achieved by blocking the key mTOR signaling components such as phosphatase and tensin homolog (PTEN). Given that multiple mTOR signaling components are endogenous inhibitory factors of this pathway, we will discuss the promising potential of RNA-based therapeutics which are particularly suitable for this purpose, and the fact that they have attracted substantial attention recently after the success of coronavirus disease 2019 vaccination. To specifically tackle the blood-brain barrier issue, we will review the current technology to deliver these RNA therapeutics into the brain with a focus on nanoparticle technology. We will propose the clinical application of these RNA-mediated therapies in combination with the brain-targeted drug delivery approach against mTOR signaling components as an effective and feasible therapeutic strategy aiming to enhance axonal regeneration for functional recovery after CNS injury.
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Affiliation(s)
- Ming-Xi Li
- Clinical Neuroscience Institute, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Jing-Wen Weng
- Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eric S Ho
- Department of Biology and Department of Computer Science, Lafayette College, Easton, PA, USA
| | - Shing Fung Chow
- Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Chi Kwan Tsang
- Clinical Neuroscience Institute, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
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Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats. Int J Mol Sci 2022; 23:ijms23031198. [PMID: 35163126 PMCID: PMC8835653 DOI: 10.3390/ijms23031198] [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: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 01/09/2023] Open
Abstract
Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound-myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.
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Campion TJ, Sheikh IS, Smit RD, Iffland PH, Chen J, Junker IP, Krynska B, Crino PB, Smith GM. Viral expression of constitutively active AKT3 induces CST axonal sprouting and regeneration, but also promotes seizures. Exp Neurol 2021; 349:113961. [PMID: 34953897 DOI: 10.1016/j.expneurol.2021.113961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 12/01/2022]
Abstract
Increasing the intrinsic growth potential of neurons after injury has repeatedly been shown to promote some level of axonal regeneration in rodent models. One of the most studied pathways involves the activation of the PI3K/AKT/mTOR pathways, primarily by reducing the levels of PTEN, a negative regulator of PI3K. Likewise, activation of signal transducer and activator of transcription 3 (STAT3) has previously been shown to boost axonal regeneration and sprouting within the injured nervous system. Here, we examined the regeneration of the corticospinal tract (CST) after cortical expression of constitutively active (ca) Akt3 and STAT3, both separately and in combination. Overexpression of caAkt3 induced regeneration of CST axons past the injury site independent of caSTAT3 overexpression. STAT3 demonstrated improved axon sprouting compared to controls and contributed to a synergistic improvement in effects when combined with Akt3 but failed to promote axonal regeneration as an individual therapy. Despite showing impressive axonal regeneration, animals expressing Akt3 failed to show any functional improvement and deteriorated with time. During this period, we observed progressive Akt3 dose-dependent increase in behavioral seizures. Histology revealed increased phosphorylation of ribosomal S6 protein within the unilateral cortex, increased neuronal size, microglia activation and hemispheric enlargement (hemimegalencephaly).
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Affiliation(s)
- Thomas J Campion
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Imran S Sheikh
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Rupert D Smit
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Philip H Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jie Chen
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Ian P Junker
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Barbara Krynska
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - George M Smith
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America.
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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; 6:150120. [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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Zhang C, Tian F, Tan Z, Du J, Long X. Altered Expression of Par3, aPKC-λ, and Lgl1 in Hippocampus in Kainic Acid-Induced Status Epilepticus Rat Model. Front Neurol 2021; 12:780042. [PMID: 34956060 PMCID: PMC8692670 DOI: 10.3389/fneur.2021.780042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/08/2021] [Indexed: 12/13/2022] Open
Abstract
Introduction: Mossy fiber sprouting (MFS) is a frequent histopathological finding in temporal lobe epilepsy (TLE) and is involved in the pathology of TLE. However, molecular signals underlying MFS remain unclear. Partitioning defective 3(Par3), atypical protein kinase C-λ(aPKC-λ), and lethal giant larvae 1(Lgl1) were involved in the neuronal polarity and axon growth. The potential roles of those proteins in MFS and epileptogenesis of TLE were investigated.Material and Methods: The epileptic rat models were established by intracerebroventricular injection of kainic acid (KA). The degree of MFS was measured by using Timm staining, Neuronal loss and the expression aPKC-λ, Par3, and Lgl1 in hippocampus were measured by using immunohistochemistry and western blot analysis.Results: The neuronal loss in CA3 region was observed from 3 days to 8 weeks, while the neuronal loss in the hilar region was observed from 1 to 8 weeks in experimental group. The Timm score in the CA3 region in experimental group was significantly higher than that in the control group from 2 to 8 weeks. Compared with control group, the expressions of Par3 and Lgl1 were upregulated and the expression of aPKC-λ was downregulated in the experimental groups. Positive correlation between the Par3 expression and Timm scores, and the negative correlation between the aPKC-λ expression and Timm scores in CA3 region were discovered in experimental group.Conclusion: The findings of the present study indicated that aPKC-λ, Par3, and Lgl1 may be involved in MFS and in the epileptogenesis of temporal lobe epilepsy.
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Affiliation(s)
- Chen Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Fafa Tian
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Zheren Tan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Juan Du
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoyan Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Xiaoyan Long ;
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32
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Park Y, Chung TS, Lee G, Rogers JA. Materials Chemistry of Neural Interface Technologies and Recent Advances in Three-Dimensional Systems. Chem Rev 2021; 122:5277-5316. [PMID: 34739219 DOI: 10.1021/acs.chemrev.1c00639] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Advances in materials chemistry and engineering serve as the basis for multifunctional neural interfaces that span length scales from individual neurons to neural networks, neural tissues, and complete neural systems. Such technologies exploit electrical, electrochemical, optical, and/or pharmacological modalities in sensing and neuromodulation for fundamental studies in neuroscience research, with additional potential to serve as routes for monitoring and treating neurodegenerative diseases and for rehabilitating patients. This review summarizes the essential role of chemistry in this field of research, with an emphasis on recently published results and developing trends. The focus is on enabling materials in diverse device constructs, including their latest utilization in 3D bioelectronic frameworks formed by 3D printing, self-folding, and mechanically guided assembly. A concluding section highlights key challenges and future directions.
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Affiliation(s)
- Yoonseok Park
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, Illinois 60208, United States
| | - Ted S Chung
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, Illinois 60208, United States.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Geumbee Lee
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, Illinois 60208, United States
| | - John A Rogers
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, Illinois 60208, United States.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208, United States.,Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.,Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Department of Neurological Surgery, Northwestern University, Evanston, Illinois 60208, United States
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Recurrent rewiring of the adult hippocampal mossy fiber system by a single transcriptional regulator, Id2. Proc Natl Acad Sci U S A 2021; 118:2108239118. [PMID: 34599103 PMCID: PMC8501755 DOI: 10.1073/pnas.2108239118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 12/03/2022] Open
Abstract
Neurons have an exceptional capacity to grow axons and form synaptic circuits during development but not later life. In adults, the lack of circuit formation may support retention of skilled actions and memories but also limits regeneration and repair after injuries and in disorders. Research on developing and damaged neurons has revealed many molecules that help circuit formation and regeneration, and yet factors that could induce axon growth and synapse formation in adult brain neurons remain elusive. Here, we searched for such key molecules and find one that alone can induce complete circuit formation. After engineering a new circuit in adult mice, we also looked into its function and relevance for memories. Circuit formation in the central nervous system has been historically studied during development, after which cell-autonomous and nonautonomous wiring factors inactivate. In principle, balanced reactivation of such factors could enable further wiring in adults, but their relative contributions may be circuit dependent and are largely unknown. Here, we investigated hippocampal mossy fiber sprouting to gain insight into wiring mechanisms in mature circuits. We found that sole ectopic expression of Id2 in granule cells is capable of driving mossy fiber sprouting in healthy adult mouse and rat. Mice with the new mossy fiber circuit solved spatial problems equally well as controls but appeared to rely on local rather than global spatial cues. Our results demonstrate reprogrammed connectivity in mature neurons by one defined factor and an assembly of a new synaptic circuit in adult brain.
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Lentini C, d'Orange M, Marichal N, Trottmann MM, Vignoles R, Foucault L, Verrier C, Massera C, Raineteau O, Conzelmann KK, Rival-Gervier S, Depaulis A, Berninger B, Heinrich C. Reprogramming reactive glia into interneurons reduces chronic seizure activity in a mouse model of mesial temporal lobe epilepsy. Cell Stem Cell 2021; 28:2104-2121.e10. [PMID: 34592167 PMCID: PMC8657801 DOI: 10.1016/j.stem.2021.09.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 07/20/2021] [Accepted: 09/03/2021] [Indexed: 12/03/2022]
Abstract
Reprogramming brain-resident glial cells into clinically relevant induced neurons (iNs) is an emerging strategy toward replacing lost neurons and restoring lost brain functions. A fundamental question is now whether iNs can promote functional recovery in pathological contexts. We addressed this question in the context of therapy-resistant mesial temporal lobe epilepsy (MTLE), which is associated with hippocampal seizures and degeneration of hippocampal GABAergic interneurons. Using a MTLE mouse model, we show that retrovirus-driven expression of Ascl1 and Dlx2 in reactive hippocampal glia in situ, or in cortical astroglia grafted in the epileptic hippocampus, causes efficient reprogramming into iNs exhibiting hallmarks of interneurons. These induced interneurons functionally integrate into epileptic networks and establish GABAergic synapses onto dentate granule cells. MTLE mice with GABAergic iNs show a significant reduction in both the number and cumulative duration of spontaneous recurrent hippocampal seizures. Thus glia-to-neuron reprogramming is a potential disease-modifying strategy to reduce seizures in therapy-resistant epilepsy. Retroviruses target reactive hippocampal glia proliferating in a mouse model of mesial temporal lobe epilepsy Ascl1 and Dlx2 reprogram reactive glia into GABAergic interneurons in the epileptic hippocampus Induced interneurons establish GABAergic synapses onto dentate granule cells Induced interneurons reduce chronic epileptic activity in the hippocampus
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Affiliation(s)
- Célia Lentini
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Marie d'Orange
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Nicolás Marichal
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK
| | - Marie-Madeleine Trottmann
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Rory Vignoles
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Louis Foucault
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Charlotte Verrier
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Céline Massera
- Univ Grenoble Alpes, Inserm U1216, Grenoble Institut des Neurosciences, 38000 Grenoble, France
| | - Olivier Raineteau
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer-Institute Virology, Medical Faculty & Gene Center, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Sylvie Rival-Gervier
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, INRAE, Stem Cell and Brain Research Institute U1208, CSC USC1361, 69500 Bron, France
| | - Antoine Depaulis
- Univ Grenoble Alpes, Inserm U1216, Grenoble Institut des Neurosciences, 38000 Grenoble, France
| | - Benedikt Berninger
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE1 1UL, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK; Institute of Physiological Chemistry, University Medical Center, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Christophe Heinrich
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France.
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A Warburg-like metabolic program coordinates Wnt, AMPK, and mTOR signaling pathways in epileptogenesis. PLoS One 2021; 16:e0252282. [PMID: 34358226 PMCID: PMC8345866 DOI: 10.1371/journal.pone.0252282] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 05/12/2021] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a complex neurological condition characterized by repeated spontaneous seizures and can be induced by initiating seizures known as status epilepticus (SE). Elaborating the critical molecular mechanisms following SE are central to understanding the establishment of chronic seizures. Here, we identify a transient program of molecular and metabolic signaling in the early epileptogenic period, centered on day five following SE in the pre-clinical kainate or pilocarpine models of temporal lobe epilepsy. Our work now elaborates a new molecular mechanism centered around Wnt signaling and a growing network comprised of metabolic reprogramming and mTOR activation. Biochemical, metabolomic, confocal microscopy and mouse genetics experiments all demonstrate coordinated activation of Wnt signaling, predominantly in neurons, and the ensuing induction of an overall aerobic glycolysis (Warburg-like phenomenon) and an altered TCA cycle in early epileptogenesis. A centerpiece of the mechanism is the regulation of pyruvate dehydrogenase (PDH) through its kinase and Wnt target genes PDK4. Intriguingly, PDH is a central gene in certain genetic epilepsies, underscoring the relevance of our elaborated mechanisms. While sharing some features with cancers, the Warburg-like metabolism in early epileptogenesis is uniquely split between neurons and astrocytes to achieve an overall novel metabolic reprogramming. This split Warburg metabolic reprogramming triggers an inhibition of AMPK and subsequent activation of mTOR, which is a signature event of epileptogenesis. Interrogation of the mechanism with the metabolic inhibitor 2-deoxyglucose surprisingly demonstrated that Wnt signaling and the resulting metabolic reprogramming lies upstream of mTOR activation in epileptogenesis. To augment the pre-clinical pilocarpine and kainate models, aspects of the proposed mechanisms were also investigated and correlated in a genetic model of constitutive Wnt signaling (deletion of the transcriptional repressor and Wnt pathway inhibitor HBP1). The results from the HBP1-/- mice provide a genetic evidence that Wnt signaling may set the threshold of acquired seizure susceptibility with a similar molecular framework. Using biochemistry and genetics, this paper outlines a new molecular framework of early epileptogenesis and advances a potential molecular platform for refining therapeutic strategies in attenuating recurrent seizures.
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Santos VR, Melo IS, Pacheco ALD, Castro OWD. Life and death in the hippocampus: What's bad? Epilepsy Behav 2021; 121:106595. [PMID: 31759972 DOI: 10.1016/j.yebeh.2019.106595] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/30/2019] [Accepted: 10/01/2019] [Indexed: 01/13/2023]
Abstract
The hippocampal formation is crucial for the generation and regulation of several brain functions, including memory and learning processes; however, it is vulnerable to neurological disorders, such as epilepsy. Temporal lobe epilepsy (TLE), the most common type of epilepsy, changes the hippocampal circuitry and excitability, under the contribution of both neuronal degeneration and abnormal neurogenesis. Classically, neurodegeneration affects sensitive areas of the hippocampus, such as dentate gyrus (DG) hilus, as well as specific fields of the Ammon's horn, CA3, and CA1. In addition, the proliferation, migration, and abnormal integration of newly generated hippocampal granular cells (GCs) into the brain characterize TLE neurogenesis. Robust studies over the years have intensely discussed the effects of death and life in the hippocampus, though there are still questions to be answered about their possible benefits and risks. Here, we review the impacts of death and life in the hippocampus, discussing its influence on TLE, providing new perspectives or insights for the implementation of new possible therapeutic targets. This article is part of the Special Issue "NEWroscience 2018".
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Affiliation(s)
- Victor Rodrigues Santos
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil.
| | - Igor Santana Melo
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceio, Brazil
| | | | - Olagide Wagner de Castro
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceio, Brazil.
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Sánchez-Puelles C, Calleja-Felipe M, Ouro A, Bougamra G, Arroyo A, Diez I, Erramuzpe A, Cortés J, Martínez-Hernández J, Luján R, Navarrete M, Venero C, Chan A, Morales M, Esteban JA, Knafo S. PTEN Activity Defines an Axis for Plasticity at Cortico-Amygdala Synapses and Influences Social Behavior. Cereb Cortex 2021; 30:505-524. [PMID: 31240311 DOI: 10.1093/cercor/bhz103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/29/2019] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphatase and tensin homolog on chromosome 10 (PTEN) is a tumor suppressor and autism-associated gene that exerts an important influence over neuronal structure and function during development. In addition, it participates in synaptic plasticity processes in adulthood. As an attempt to assess synaptic and developmental mechanisms by which PTEN can modulate cognitive function, we studied the consequences of 2 different genetic manipulations in mice: presence of additional genomic copies of the Pten gene (Ptentg) and knock-in of a truncated Pten gene lacking its PDZ motif (Pten-ΔPDZ), which is required for interaction with synaptic proteins. Ptentg mice exhibit substantial microcephaly, structural hypoconnectivity, enhanced synaptic depression at cortico-amygdala synapses, reduced anxiety, and intensified social interactions. In contrast, Pten-ΔPDZ mice have a much more restricted phenotype, with normal synaptic connectivity, but impaired synaptic depression at cortico-amygdala synapses and virtually abolished social interactions. These results suggest that synaptic actions of PTEN in the amygdala contribute to specific behavioral traits, such as sociability. Also, PTEN appears to function as a bidirectional rheostat in the amygdala: reduction in PTEN activity at synapses is associated with less sociability, whereas enhanced PTEN activity accompanies hypersocial behavior.
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Affiliation(s)
- Cristina Sánchez-Puelles
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain.,Department of Molecular Neurobiology, Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - María Calleja-Felipe
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain
| | - Alberto Ouro
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain
| | - Ghassen Bougamra
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain
| | - Ana Arroyo
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain
| | - Ibai Diez
- Computational Neuroimaging Laboratory, Biocruces Health Research Institute, 48903 Barakaldo, Spain
| | - Asier Erramuzpe
- Computational Neuroimaging Laboratory, Biocruces Health Research Institute, 48903 Barakaldo, Spain
| | - Jesús Cortés
- Computational Neuroimaging Laboratory, Biocruces Health Research Institute, 48903 Barakaldo, Spain.,Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| | - José Martínez-Hernández
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Rafael Luján
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Marta Navarrete
- Department of Molecular Neurobiology, Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - César Venero
- Department of Psychobiology, Universidad Nacional de Educación a Distancia, 28040 Madrid, Spain
| | - Andrew Chan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Miguel Morales
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain
| | - José A Esteban
- Department of Molecular Neurobiology, Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Shira Knafo
- Molecular Cognition Laboratory, Biophysics Institute, Consejo Superior de Investigaciones Cientificas (CSIC)-University of the Basque Country (UPV)/Euskal Herriko University (EHU), Campus Universidad del País Vasco, 48940 Leioa, Spain.,Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.,Department of Physiology and Cell Biology and National Institute of Biotechnology in the Negev, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501 Israel
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Ahmed MM, Carrel AJ, Cruz Del Angel Y, Carlsen J, Thomas AX, González MI, Gardiner KJ, Brooks-Kayal A. Altered Protein Profiles During Epileptogenesis in the Pilocarpine Mouse Model of Temporal Lobe Epilepsy. Front Neurol 2021; 12:654606. [PMID: 34122302 PMCID: PMC8194494 DOI: 10.3389/fneur.2021.654606] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 04/06/2021] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is characterized by recurrent, spontaneous seizures and is a major contributor to the global burden of neurological disease. Although epilepsy can result from a variety of brain insults, in many cases the cause is unknown and, in a significant proportion of cases, seizures cannot be controlled by available treatments. Understanding the molecular alterations that underlie or are triggered by epileptogenesis would help to identify therapeutics to prevent or control progression to epilepsy. To this end, the moderate throughput technique of Reverse Phase Protein Arrays (RPPA) was used to profile changes in protein expression in a pilocarpine mouse model of acquired epilepsy. Levels of 54 proteins, comprising phosphorylation-dependent and phosphorylation-independent components of major signaling pathways and cellular complexes, were measured in hippocampus, cortex and cerebellum of mice at six time points, spanning 15 min to 2 weeks after induction of status epilepticus. Results illustrate the time dependence of levels of the commonly studied MTOR pathway component, pS6, and show, for the first time, detailed responses during epileptogenesis of multiple components of the MTOR, MAPK, JAK/STAT and apoptosis pathways, NMDA receptors, and additional cellular complexes. Also noted are time- and brain region- specific changes in correlations among levels of functionally related proteins affecting both neurons and glia. While hippocampus and cortex are primary areas studied in pilocarpine-induced epilepsy, cerebellum also shows significant time-dependent molecular responses.
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Affiliation(s)
- Md Mahiuddin Ahmed
- Department of Neurology, University of Colorado Alzheimer's and Cognition Center, Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Andrew J Carrel
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Yasmin Cruz Del Angel
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Jessica Carlsen
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Ajay X Thomas
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States.,Section of Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States.,Section of Child Neurology, Texas Children's Hospital, Houston, TX, United States
| | - Marco I González
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Katheleen J Gardiner
- Department of Pediatrics, Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Amy Brooks-Kayal
- Division of Neurology and Translational Epilepsy Research Program, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States.,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Children's Hospital Colorado, Aurora, CO, United States.,Department of Neurology, University of California Davis School of Medicine, Sacramento, CA, United States
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39
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Littlejohn EL, DeSana AJ, Williams HC, Chapman RT, Joseph B, Juras JA, Saatman KE. IGF1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent on mTOR. Front Cell Dev Biol 2021; 9:663456. [PMID: 34095131 PMCID: PMC8174097 DOI: 10.3389/fcell.2021.663456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/26/2021] [Indexed: 01/29/2023] Open
Abstract
Adult hippocampal neurogenesis is stimulated acutely following traumatic brain injury (TBI). However, many hippocampal neurons born after injury develop abnormally and the number that survive long-term is debated. In experimental TBI, insulin-like growth factor-1 (IGF1) promotes hippocampal neuronal differentiation, improves immature neuron dendritic arbor morphology, increases long-term survival of neurons born after TBI, and improves cognitive function. One potential downstream mediator of the neurogenic effects of IGF1 is mammalian target of rapamycin (mTOR), which regulates proliferation as well as axonal and dendritic growth in the CNS. Excessive mTOR activation is posited to contribute to aberrant plasticity related to posttraumatic epilepsy, spurring preclinical studies of mTOR inhibitors as therapeutics for TBI. The degree to which pro-neurogenic effects of IGF1 depend upon upregulation of mTOR activity is currently unknown. Using immunostaining for phosphorylated ribosomal protein S6, a commonly used surrogate for mTOR activation, we show that controlled cortical impact TBI triggers mTOR activation in the dentate gyrus in a time-, region-, and injury severity-dependent manner. Posttraumatic mTOR activation in the granule cell layer (GCL) and dentate hilus was amplified in mice with conditional overexpression of IGF1. In contrast, delayed astrocytic activation of mTOR signaling within the dentate gyrus molecular layer, closely associated with proliferation, was not affected by IGF1 overexpression. To determine whether mTOR activation is necessary for IGF1-mediated stimulation of posttraumatic hippocampal neurogenesis, wildtype and IGF1 transgenic mice received the mTOR inhibitor rapamycin daily beginning at 3 days after TBI, following pulse labeling with bromodeoxyuridine. Compared to wildtype mice, IGF1 overexpressing mice exhibited increased posttraumatic neurogenesis, with a higher density of posttrauma-born GCL neurons at 10 days after injury. Inhibition of mTOR did not abrogate IGF1-stimulated enhancement of posttraumatic neurogenesis. Rather, rapamycin treatment in IGF1 transgenic mice, but not in WT mice, increased numbers of cells labeled with BrdU at 3 days after injury that survived to 10 days, and enhanced the proportion of posttrauma-born cells that differentiated into neurons. Because beneficial effects of IGF1 on hippocampal neurogenesis were maintained or even enhanced with delayed inhibition of mTOR, combination therapy approaches may hold promise for TBI.
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Affiliation(s)
| | | | | | | | | | | | - Kathryn E. Saatman
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
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40
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Chen L, Wang Y, Chen Z. Adult Neurogenesis in Epileptogenesis: An Update for Preclinical Finding and Potential Clinical Translation. Curr Neuropharmacol 2021; 18:464-484. [PMID: 31744451 PMCID: PMC7457402 DOI: 10.2174/1570159x17666191118142314] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/31/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022] Open
Abstract
Epileptogenesis refers to the process in which a normal brain becomes epileptic, and is characterized by hypersynchronous spontaneous recurrent seizures involving a complex epileptogenic network. Current available pharmacological treatment of epilepsy is generally symptomatic in controlling seizures but is not disease-modifying in epileptogenesis. Cumulative evidence suggests that adult neurogenesis, specifically in the subgranular zone of the hippocampal dentate gyrus, is crucial in epileptogenesis. In this review, we describe the pathological changes that occur in adult neurogenesis in the epileptic brain and how adult neurogenesis is involved in epileptogenesis through different interventions. This is followed by a discussion of some of the molecular signaling pathways involved in regulating adult neurogenesis, which could be potential druggable targets for epileptogenesis. Finally, we provide perspectives on some possible research directions for future studies.
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Affiliation(s)
- Liying Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
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41
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Lybrand ZR, Goswami S, Zhu J, Jarzabek V, Merlock N, Aktar M, Smith C, Zhang L, Varma P, Cho KO, Ge S, Hsieh J. A critical period of neuronal activity results in aberrant neurogenesis rewiring hippocampal circuitry in a mouse model of epilepsy. Nat Commun 2021; 12:1423. [PMID: 33658509 PMCID: PMC7930276 DOI: 10.1038/s41467-021-21649-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/04/2021] [Indexed: 01/31/2023] Open
Abstract
In the mammalian hippocampus, adult-born granule cells (abGCs) contribute to the function of the dentate gyrus (DG). Disruption of the DG circuitry causes spontaneous recurrent seizures (SRS), which can lead to epilepsy. Although abGCs contribute to local inhibitory feedback circuitry, whether they are involved in epileptogenesis remains elusive. Here, we identify a critical window of activity associated with the aberrant maturation of abGCs characterized by abnormal dendrite morphology, ectopic migration, and SRS. Importantly, in a mouse model of temporal lobe epilepsy, silencing aberrant abGCs during this critical period reduces abnormal dendrite morphology, cell migration, and SRS. Using mono-synaptic tracers, we show silencing aberrant abGCs decreases recurrent CA3 back-projections and restores proper cortical connections to the hippocampus. Furthermore, we show that GABA-mediated amplification of intracellular calcium regulates the early critical period of activity. Our results demonstrate that aberrant neurogenesis rewires hippocampal circuitry aggravating epilepsy in mice.
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Affiliation(s)
- Zane R Lybrand
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
- Department of Biology, Texas Woman's University, Denton, TX, USA
| | - Sonal Goswami
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Jingfei Zhu
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Veronica Jarzabek
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Nikolas Merlock
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Mahafuza Aktar
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Courtney Smith
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Ling Zhang
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Parul Varma
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Kyung-Ok Cho
- Department of Pharmacology, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea
- Department of Biomedicine & Health Sciences, Institute of Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Shaoyu Ge
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Jenny Hsieh
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA.
- Brain Health Consortium, The University of Texas at San Antonio, San Antonio, TX, USA.
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Porat Rein A, Kramer U, Hausman Kedem M, Fattal-Valevski A, Mitelpunkt A. Early prediction of encephalopathic transformation in children with benign epilepsy with centro-temporal spikes. Brain Dev 2021; 43:268-279. [PMID: 32912653 DOI: 10.1016/j.braindev.2020.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/06/2020] [Accepted: 08/18/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Most children with Benign epilepsy with centro-temporal spikes (BECTS) undergo remission during late adolescence and do not require treatment. In a small group of patients, the condition may evolve to encephalopathic syndromes including epileptic encephalopathy with continuous spike-and-wave during sleep (ECSWS), or Landau-Kleffner Syndrome (LKS). Development of prediction models for early identification of at-risk children is of utmost importance. AIM To develop a predictive model of encephalopathic transformation using data-driven approaches, reveal complex interactions to identify potential risk factors. METHODS Data were collected from a cohort of 91 patients diagnosed with BECTS treated between the years 2005-2017 at a pediatric neurology institute. Data on the initial presentation was collected based on a novel BECTS ontology and used to discover potential risk factors and to build a predictive model. Statistical and machine learning methods were compared. RESULTS A subgroup of 18 children had encephalopathic transformation. The least absolute shrinkage and selection operator (LASSO) regression Model with Elastic Net was able to successfully detect children with ECSWS or LKS. Sensitivity and specificity were 0.83 and 0.44. The most notable risk factors were fronto-temporal and temporo-parietal localization of epileptic foci, semiology of seizure involving dysarthria or somatosensory auras. CONCLUSION Novel prediction model for early identification of patients with BECTS at risk for ECSWS or LKS. This model can be used as a screening tool and assist physicians to consider special management for children predicted at high-risk. Clinical application of machine learning methods opens new frontiers of personalized patient care and treatment.
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Affiliation(s)
- Adi Porat Rein
- Sackler Faculty of Medicine, Tel-Aviv University, Israel.
| | - Uri Kramer
- Sackler Faculty of Medicine, Tel-Aviv University, Israel; Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Israel
| | - Moran Hausman Kedem
- Sackler Faculty of Medicine, Tel-Aviv University, Israel; Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Israel
| | - Aviva Fattal-Valevski
- Sackler Faculty of Medicine, Tel-Aviv University, Israel; Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Israel
| | - Alexis Mitelpunkt
- Sackler Faculty of Medicine, Tel-Aviv University, Israel; Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Israel
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43
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Alcantara-Gonzalez D, Chartampila E, Criscuolo C, Scharfman HE. Early changes in synaptic and intrinsic properties of dentate gyrus granule cells in a mouse model of Alzheimer's disease neuropathology and atypical effects of the cholinergic antagonist atropine. Neurobiol Dis 2021; 152:105274. [PMID: 33484828 DOI: 10.1016/j.nbd.2021.105274] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/09/2021] [Accepted: 01/16/2021] [Indexed: 12/19/2022] Open
Abstract
It has been reported that hyperexcitability occurs in a subset of patients with Alzheimer's disease (AD) and hyperexcitability could contribute to the disease. Several studies have suggested that the hippocampal dentate gyrus (DG) may be an important area where hyperexcitability occurs. Therefore, we tested the hypothesis that the principal DG cell type, granule cells (GCs), would exhibit changes at the single-cell level which would be consistent with hyperexcitability and might help explain it. We used the Tg2576 mouse, where it has been shown that hyperexcitability is robust at 2-3 months of age. GCs from 2 to 3-month-old Tg2576 mice were compared to age-matched wild type (WT) mice. Effects of muscarinic cholinergic antagonism were tested because previously we found that Tg2576 mice exhibited hyperexcitability in vivo that was reduced by the muscarinic cholinergic antagonist atropine, counter to the dogma that in AD one needs to boost cholinergic function. The results showed that GCs from Tg2576 mice exhibited increased frequency of spontaneous excitatory postsynaptic potentials/currents (sEPSP/Cs) and reduced frequency of spontaneous inhibitory synaptic events (sIPSCs) relative to WT, increasing the excitation:inhibition (E:I) ratio. There was an inward NMDA receptor-dependent current that we defined here as a novel synaptic current (nsC) in Tg2576 mice because it was very weak in WT mice. Intrinsic properties were distinct in Tg2576 GCs relative to WT. In summary, GCs of the Tg2576 mouse exhibit early electrophysiological alterations that are consistent with increased synaptic excitation, reduced inhibition, and muscarinic cholinergic dysregulation. The data support previous suggestions that the DG contributes to hyperexcitability and there is cholinergic dysfunction early in life in AD mouse models.
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Affiliation(s)
- David Alcantara-Gonzalez
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Elissavet Chartampila
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Chiara Criscuolo
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Helen E Scharfman
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, New York University Langone Health, New York, NY 10016, USA; Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA.
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44
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Shi Z, Lei Z, Wu F, Xia L, Ruan Y, Xu ZC. Increased Sestrin3 Contributes to Post-ischemic Seizures in the Diabetic Condition. Front Neurosci 2021; 14:591207. [PMID: 33519354 PMCID: PMC7843462 DOI: 10.3389/fnins.2020.591207] [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: 08/04/2020] [Accepted: 12/14/2020] [Indexed: 11/13/2022] Open
Abstract
Seizures are among the most common neurological sequelae of stroke, and diabetes notably increases the incidence of post-ischemic seizures. Recent studies have indicated that Sestrin3 (SESN3) is a regulator of a proconvulsant gene network in human epileptic hippocampus. But the association of SESN3 and post-ischemic seizures in diabetes remains unclear. The present study aimed to reveal the involvement of SESN3 in seizures following transient cerebral ischemia in diabetes. Diabetes was induced in adult male mice and rats via intraperitoneal injection of streptozotocin (STZ). Forebrain ischemia (15 min) was induced by bilateral common carotid artery occlusion, the 2-vessel occlusion (2VO) in mice and 4-vessel occlusion (4VO) in rats. Our results showed that 59% of the diabetic wild-type mice developed seizures after ischemia while no seizures were observed in non-diabetic mice. Although no apparent cell death was detected in the hippocampus of seizure mice within 24 h after the ischemic insult, the expression of SESN3 was significantly increased in seizure diabetic mice after ischemia. The post-ischemic seizure incidence significantly decreased in SESN3 knockout mice. Furthermore, all diabetic rats suffered from post-ischemic seizures and non-diabetic rats have no seizures. Electrophysiological recording showed an increased excitatory synaptic transmission and intrinsic membrane excitability in dentate granule cells of the rat hippocampus, together with decreased I A currents and Kv4.2 expression levels. The above results suggest that SESN3 up-regulation may contribute to neuronal hyperexcitability and seizure generation in diabetic animals after ischemia. Further studies are needed to explore the molecular mechanism of SESN3 in seizure generation after ischemia in diabetic conditions.
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Affiliation(s)
- Zhongshan Shi
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States.,Guangdong-Hongkong-Macau Institute for CNS Regeneration, Jinan University, Guangzhou, China.,Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhigang Lei
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Fan Wu
- Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Luoxing Xia
- Guangdong-Hongkong-Macau Institute for CNS Regeneration, Jinan University, Guangzhou, China
| | - Yiwen Ruan
- Guangdong-Hongkong-Macau Institute for CNS Regeneration, Jinan University, Guangzhou, China.,Jiangsu Province Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Zao C Xu
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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Anterior thalamic nuclei deep brain stimulation inhibits mossy fiber sprouting via 3',5'-cyclic adenosine monophosphate/protein kinase A signaling pathway in a chronic epileptic monkey model. Chin Med J (Engl) 2021; 134:326-333. [PMID: 33410631 PMCID: PMC7846430 DOI: 10.1097/cm9.0000000000001302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Background Anterior thalamic nuclei (ATN) deep brain stimulation (DBS) is an effective method of controlling epilepsy, especially temporal lobe epilepsy. Mossy fiber sprouting (MFS) plays an indispensable role in the pathogenesis and progression of epilepsy, but the effect of ATN-DBS on MFS in the chronic stage of epilepsy and the potential underlying mechanisms are unknown. This study aimed to investigate the effect of ATN-DBS on MFS, as well as potential signaling pathways by a kainic acid (KA)-induced epileptic model. Methods Twenty-four rhesus monkeys were randomly assigned to control, epilepsy (EP), EP-sham-DBS, and EP-DBS groups. KA was injected to establish the chronic epileptic model. The left ATN was implanted with a DBS lead and stimulated for 8 weeks. Enzyme-linked immunosorbent assay, Western blotting, and immunofluorescence staining were used to evaluate MFS and levels of potential molecular mediators in the hippocampus. One-way analysis of variance, followed by the Tukey post hoc correction, was used to analyze the statistical significance of differences among multiple groups. Results ATN-DBS is found to significantly reduce seizure frequency in the chronic stage of epilepsy. The number of ectopic granule cells was reduced in monkeys that received ATN stimulation (P < 0.0001). Levels of 3′,5′-cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) in the hippocampus, together with Akt phosphorylation, were noticeably reduced in monkeys that received ATN stimulation (P = 0.0030 and P = 0.0001, respectively). ATN-DBS also significantly reduced MFS scores in the hippocampal dentate gyrus and CA3 sub-regions (all P < 0.0001). Conclusion ATN-DBS is shown to down-regulate the cAMP/PKA signaling pathway and Akt phosphorylation and to reduce the number of ectopic granule cells, which may be associated with the reduced MFS in chronic epilepsy. The study provides further insights into the mechanism by which ATN-DBS reduces epileptic seizures.
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LaSarge CL, Pun RYK, Gu Z, Riccetti MR, Namboodiri DV, Tiwari D, Gross C, Danzer SC. mTOR-driven neural circuit changes initiate an epileptogenic cascade. Prog Neurobiol 2020; 200:101974. [PMID: 33309800 DOI: 10.1016/j.pneurobio.2020.101974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/22/2020] [Accepted: 12/05/2020] [Indexed: 11/29/2022]
Abstract
Mutations in genes regulating mTOR pathway signaling are now recognized as a significant cause of epilepsy. Interestingly, these mTORopathies are often caused by somatic mutations, affecting variable numbers of neurons. To better understand how this variability affects disease phenotype, we developed a mouse model in which the mTOR pathway inhibitor Pten can be deleted from 0 to 40 % of hippocampal granule cells. In vivo, low numbers of knockout cells caused focal seizures, while higher numbers led to generalized seizures. Generalized seizures coincided with the loss of local circuit interneurons. In hippocampal slices, low knockout cell loads produced abrupt reductions in population spike threshold, while spontaneous excitatory postsynaptic currents and circuit level recurrent activity increased gradually with rising knockout cell load. Findings demonstrate that knockout cells load is a critical variable regulating disease phenotype, progressing from subclinical circuit abnormalities to electrobehavioral seizures with secondary involvement of downstream neuronal populations.
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Affiliation(s)
- Candi L LaSarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Center for Pediatric Neuroscience, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Raymund Y K Pun
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Center for Pediatric Neuroscience, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Zhiqing Gu
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Shanghai Children's Hospital, Shanghai, 200062, China
| | - Matthew R Riccetti
- Molecular and Developmental Biology Graduate Program, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Devi V Namboodiri
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Durgesh Tiwari
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christina Gross
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Center for Pediatric Neuroscience, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Molecular and Developmental Biology Graduate Program, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States; Department of Anesthesia, University of Cincinnati, Cincinnati, OH, 45267, United States.
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Trovato F, Parra R, Pracucci E, Landi S, Cozzolino O, Nardi G, Cruciani F, Pillai V, Mosti L, Cwetsch AW, Cancedda L, Gritti L, Sala C, Verpelli C, Maset A, Lodovichi C, Ratto GM. Modelling genetic mosaicism of neurodevelopmental disorders in vivo by a Cre-amplifying fluorescent reporter. Nat Commun 2020; 11:6194. [PMID: 33273479 PMCID: PMC7713426 DOI: 10.1038/s41467-020-19864-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022] Open
Abstract
Genetic mosaicism, a condition in which an organ includes cells with different genotypes, is frequently present in monogenic diseases of the central nervous system caused by the random inactivation of the X-chromosome, in the case of X-linked pathologies, or by somatic mutations affecting a subset of neurons. The comprehension of the mechanisms of these diseases and of the cell-autonomous effects of specific mutations requires the generation of sparse mosaic models, in which the genotype of each neuron is univocally identified by the expression of a fluorescent protein in vivo. Here, we show a dual-color reporter system that, when expressed in a floxed mouse line for a target gene, leads to the creation of mosaics with tunable degree. We demonstrate the generation of a knockout mosaic of the autism/epilepsy related gene PTEN in which the genotype of each neuron is reliably identified, and the neuronal phenotype is accurately characterized by two-photon microscopy.
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Affiliation(s)
- Francesco Trovato
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy.
| | - Riccardo Parra
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Enrico Pracucci
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Silvia Landi
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
- Institute of Neuroscience CNR, Pisa, Italy
| | - Olga Cozzolino
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Gabriele Nardi
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Federica Cruciani
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Vinoshene Pillai
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Laura Mosti
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy
| | - Andrzej W Cwetsch
- Istituto Italiano di Tecnologia, Genoa, Italy
- Università degli studi di Genova, Genoa, Italy
| | - Laura Cancedda
- Istituto Italiano di Tecnologia, Genoa, Italy
- Istituto Telethon Dulbecco, Rome, Italy
| | | | - Carlo Sala
- Institute of Neuroscience CNR, Milan, Italy
| | | | - Andrea Maset
- Veneto Institute of Molecular Medicine, Padua, Italy
- Padova Neuroscience Center, Padova Università di Padova, Padua, Italy
| | - Claudia Lodovichi
- Veneto Institute of Molecular Medicine, Padua, Italy
- Padova Neuroscience Center, Padova Università di Padova, Padua, Italy
- Institute of Neuroscience CNR, Padua, Italy
| | - Gian Michele Ratto
- National Enterprise for Nanoscience and Nanotechnology (NEST), Istituto Nanoscienze Consiglio Nazionale delle Ricerche (CNR) and Scuola Normale Superiore Pisa, 56127, Pisa, Italy.
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48
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Yu Z, Zhang M, Luo B, Jing H, Yu Y, Wang S, Luo S. Lrp4 in hippocampal astrocytes serves as a negative feedback factor in seizures. Cell Biosci 2020; 10:135. [PMID: 33292473 PMCID: PMC7684739 DOI: 10.1186/s13578-020-00498-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/11/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Epilepsy is characterized by the typical symptom of seizure, and anti-seizure medications are the main therapeutic method in clinical, but the effects of these therapy have not been satisfactory. To find a better treatment, it makes sense to further explore the regulatory mechanisms of seizures at genetic level. Lrp4 regionally expresses in mice hippocampus where is key to limbic epileptogenesis. It is well known that neurons release a high level of glutamate during seizures, and it has been reported that Lrp4 in astrocytes down-regulates glutamate released from neurons. However, it is still unclear whether there is a relationship between Lrp4 expression level and seizures, and whether Lrp4 plays a role in seizures. RESULTS We found that seizures induced by pilocarpine decreased Lrp4 expression level and increased miR-351-5p expression level in mice hippocampus. Glutamate reduced Lrp4 expression and enhanced miR-351-5p expression in cultured hippocampal astrocytes, and these effects can be partially attenuated by AP5. Furthermore, miR-351-5p inhibitor lessened the reduction of Lrp4 expression in glutamate treated hippocampal astrocytes. Local reduction of Lrp4 in hippocampus by sh Lrp4 lentivirus injection in hippocampus increased the threshold of seizures in pilocarpine or pentylenetetrazol (PTZ) injected mice. CONCLUSIONS These results indicated that high released glutamate induced by seizures down-regulated astrocytic Lrp4 through increasing miR-351-5p in hippocampal astrocytes via activating astrocytic NMDA receptor, and locally reduction of Lrp4 in hippocampus increased the threshold of seizures. Lrp4 in hippocampal astrocytes appears to serve as a negative feedback factor in seizures. This provides a new potential therapeutic target for seizures regulation.
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Affiliation(s)
- Zheng Yu
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China.,Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Meiying Zhang
- Nanchang University Hospital, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Bin Luo
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Hongyang Jing
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Yue Yu
- Teensen Genesis School, Nanchang, 330006, Jiangxi, China
| | - Shunqi Wang
- Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, 330006, Jiangxi, China
| | - Shiwen Luo
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, China. .,Jiangxi Key Laboratory of Molecular Diagnostics and Precision Medicine, 17 Yongwai Street, Donghuo Distinct, Nanchang, 330006, Jiangxi, China.
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49
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Botterill JJ, Lu YL, LaFrancois JJ, Bernstein HL, Alcantara-Gonzalez D, Jain S, Leary P, Scharfman HE. An Excitatory and Epileptogenic Effect of Dentate Gyrus Mossy Cells in a Mouse Model of Epilepsy. Cell Rep 2020; 29:2875-2889.e6. [PMID: 31775052 PMCID: PMC6905501 DOI: 10.1016/j.celrep.2019.10.100] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 09/25/2019] [Accepted: 10/24/2019] [Indexed: 12/20/2022] Open
Abstract
The sparse activity of hippocampal dentate gyrus (DG) granule cells (GCs) is thought to be critical for cognition and behavior, whereas excessive DG activity may contribute to disorders such as temporal lobe epilepsy (TLE). Glutamatergic mossy cells (MCs) of the DG are potentially critical to normal and pathological functions of the DG because they can regulate GC activity through innervation of GCs or indirectly through GABAergic neurons. Here, we test the hypothesis that MC excitation of GCs is normally weak, but under pathological conditions, MC excitation of GCs is dramatically strengthened. We show that selectively inhibiting MCs during severe seizures reduced manifestations of those seizures, hippocampal injury, and chronic epilepsy. In contrast, selectively activating MCs was pro-convulsant. Mechanistic in vitro studies using optogenetics further demonstrated the unanticipated ability of MC axons to excite GCs under pathological conditions. These results demonstrate an excitatory and epileptogenic effect of MCs in the DG.
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Affiliation(s)
- Justin J Botterill
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Yi-Ling Lu
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - John J LaFrancois
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Hannah L Bernstein
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Neuroscience & Physiology, New York University Langone Health, New York, NY 10016, USA
| | - David Alcantara-Gonzalez
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Swati Jain
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Paige Leary
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Helen E Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Neuroscience & Physiology, New York University Langone Health, New York, NY 10016, USA; Department of Psychiatry, New York University Langone Health, New York, NY 10016, USA.
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50
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McGuone D, Crandall LG, Devinsky O. Sudden Unexplained Death in Childhood: A Neuropathology Review. Front Neurol 2020; 11:582051. [PMID: 33178125 PMCID: PMC7596260 DOI: 10.3389/fneur.2020.582051] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022] Open
Abstract
Sudden Unexplained Death in Childhood (SUDC) is the unexpected death of a child over age 12 months that remains unexplained after a thorough case investigation, including review of the child's medical history, circumstances of death, a complete autopsy and ancillary testing (1). First defined in 2005, SUDC cases are more often male, with death occurring during a sleep period, being found prone, peak winter incidence, associated with febrile seizure history in ~28% of cases and mild pathologic changes insufficient to explain the death (1, 2). There has been little progress in understanding the causes of SUDC and no progress in prevention. Despite reductions in sudden unexpected infant death (SUID) and other causes of mortality in childhood, the rate of SUDC has increased during the past two decades (3-5). In Ireland, SUID deaths were cut in half from 1994 to 2008 while SUDC deaths more than doubled (4). Surveillance issues, including lack of standardized certification practices, affect our understanding of the true magnitude of unexplained child deaths. Mechanisms underlying SUDC, like SUID, remain largely speculative. Limited and inconsistent evidence implicates abnormalities in brainstem autonomic and serotonergic nuclei, critical for arousal, cardiorespiratory control, and reflex responses to life-threatening hypoxia or hypercarbia in sleep (6). Abnormalities in medullary serotonergic neurons and receptors, as well as cardiorespiratory brainstem nuclei occur in some SUID cases, but have never been studied in SUDC. Retrospective, small SUDC studies with non-standardized methodologies most often demonstrate minor hippocampal abnormalities, as well as focal cortical dysplasia and dysgenesis of the brainstem and cerebellum. The significance of these findings to SUDC pathogenesis remains unclear with some investigators and forensic pathologists labeling these findings as normal variants, or potential causes of SUDC. The development of preventive strategies will require a greater understanding of underlying mechanisms.
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Affiliation(s)
- Declan McGuone
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | - Laura G Crandall
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, United States.,SUDC Foundation, Herndon, VA, United States
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, United States
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