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Li K, Cao JF, Gong Y, Xiong L, Wu M, Qi Y, Ying X, Liu D, Ma X, Zhang X. Rapamycin improves the survival of epilepsy model cells by blocking phosphorylation of mTOR base on computer simulations and cellular experiments. Neurochem Int 2024; 176:105746. [PMID: 38641027 DOI: 10.1016/j.neuint.2024.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/08/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024]
Abstract
PURPOSE Epilepsy is a chronic brain dysfunction characterized by recurrent epileptic seizures. Rapamycin is a naturally occurring macrolide from Streptomyces hygroscopicus, and rapamycin may provide a protective effect on the nervous system by affecting mTOR. Therefore, we investigated the pharmacologic mechanism of rapamycin treating epilepsy through bioinformatics analysis, cellular experiments and supercomputer simulation. METHODS Bioinformatics analysis was used to analyze targets of rapamycin treating epilepsy. We established epilepsy cell model by HT22 cells. RT-qPCR, WB and IF were used to verify the effects of rapamycin on mTOR at gene level and protein level. Computer simulations were used to model and evaluate the stability of rapamycin binding to mTOR protein. RESULTS Bioinformatics indicated mTOR played an essential role in signaling pathways of cell growth and cell metabolism. Cellular experiments showed that rapamycin could promote cell survival, and rapamycin did not have an effect on mRNA expression of mTOR. However, rapamycin was able to significantly inhibit the phosphorylation of mTOR at protein level. Computer simulations indicated that rapamycin was involved in the treatment of epilepsy through regulating phosphorylation of mTOR at protein level. CONCLUSION We found that rapamycin was capable of promoting the survival of epilepsy cells by inhibiting the phosphorylation of mTOR at protein level, and rapamycin did not have an effect on mRNA expression of mTOR. In addition to the traditional study that rapamycin affects mTORC1 complex by acting on FKBP12, this study found rapamycin could also directly block the phosphorylation of mTOR, therefore affecting the assembly of mTORC1 complex and mTOR signaling pathway.
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Affiliation(s)
- Kezhou Li
- College of Medicine, Southwest Jiaotong University, Chengdu, China; Pancreatic Surgery, West China Hospital of Sichuan University, Chengdu, China
| | - Jun-Feng Cao
- Chengdu Medical College, Chengdu, China; College of Medicine, Southwest Jiaotong University, Chengdu, China
| | | | - Li Xiong
- Chengdu Medical College, Chengdu, China
| | - Mei Wu
- Chengdu Medical College, Chengdu, China
| | - Yue Qi
- Chengdu Medical College, Chengdu, China
| | | | | | - Xuntai Ma
- Chengdu Medical College, Chengdu, China; The First Affiliated Hospital of Clinical Medical College of Chengdu Medical College, Chengdu, China.
| | - Xiao Zhang
- Chengdu Medical College, Chengdu, China.
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Scheper M, Sørensen FNF, Ruffolo G, Gaeta A, Lissner LJ, Anink JJ, Korshunova I, Jansen FE, Riney K, van Hecke W, Mühlebner A, Khodosevich K, Schubert D, Palma E, Mills JD, Aronica E. Impaired GABAergic regulation and developmental immaturity in interneurons derived from the medial ganglionic eminence in the tuberous sclerosis complex. Acta Neuropathol 2024; 147:80. [PMID: 38714540 PMCID: PMC11076412 DOI: 10.1007/s00401-024-02737-7] [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: 03/14/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/10/2024]
Abstract
GABAergic interneurons play a critical role in maintaining neural circuit balance, excitation-inhibition regulation, and cognitive function modulation. In tuberous sclerosis complex (TSC), GABAergic neuron dysfunction contributes to disrupted network activity and associated neurological symptoms, assumingly in a cell type-specific manner. This GABAergic centric study focuses on identifying specific interneuron subpopulations within TSC, emphasizing the unique characteristics of medial ganglionic eminence (MGE)- and caudal ganglionic eminence (CGE)-derived interneurons. Using single-nuclei RNA sequencing in TSC patient material, we identify somatostatin-expressing (SST+) interneurons as a unique and immature subpopulation in TSC. The disrupted maturation of SST+ interneurons may undergo an incomplete switch from excitatory to inhibitory GABAergic signaling during development, resulting in reduced inhibitory properties. Notably, this study reveals markers of immaturity specifically in SST+ interneurons, including an abnormal NKCC1/KCC2 ratio, indicating an imbalance in chloride homeostasis crucial for the postsynaptic consequences of GABAergic signaling as well as the downregulation of GABAA receptor subunits, GABRA1, and upregulation of GABRA2. Further exploration of SST+ interneurons revealed altered localization patterns of SST+ interneurons in TSC brain tissue, concentrated in deeper cortical layers, possibly linked to cortical dyslamination. In the epilepsy context, our research underscores the diverse cell type-specific roles of GABAergic interneurons in shaping seizures, advocating for precise therapeutic considerations. Moreover, this study illuminates the potential contribution of SST+ interneurons to TSC pathophysiology, offering insights for targeted therapeutic interventions.
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Affiliation(s)
- Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
| | - Frederik N F Sørensen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
- IRCCS San Raffaele Roma, 00163, Rome, Italy
| | - Alessandro Gaeta
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
| | - Lilian J Lissner
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
| | - Jasper J Anink
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Irina Korshunova
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Floor E Jansen
- Department of Child Neurology, Brain Center University Medical Center, Member of ERN EpiCare, 3584 BA, Utrecht, The Netherlands
| | - Kate Riney
- Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4067, Australia
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, QLD, 4101, Australia
| | - Wim van Hecke
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Angelika Mühlebner
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Konstantin Khodosevich
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Dirk Schubert
- Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR, Nijmegen, The Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
- IRCCS San Raffaele Roma, 00163, Rome, Italy
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks, SL9 0RJ, UK
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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3
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Ravizza T, Scheper M, Di Sapia R, Gorter J, Aronica E, Vezzani A. mTOR and neuroinflammation in epilepsy: implications for disease progression and treatment. Nat Rev Neurosci 2024; 25:334-350. [PMID: 38531962 DOI: 10.1038/s41583-024-00805-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2024] [Indexed: 03/28/2024]
Abstract
Epilepsy remains a major health concern as anti-seizure medications frequently fail, and there is currently no treatment to stop or prevent epileptogenesis, the process underlying the onset and progression of epilepsy. The identification of the pathological processes underlying epileptogenesis is instrumental to the development of drugs that may prevent the generation of seizures or control pharmaco-resistant seizures, which affect about 30% of patients. mTOR signalling and neuroinflammation have been recognized as critical pathways that are activated in brain cells in epilepsy. They represent a potential node of biological convergence in structural epilepsies with either a genetic or an acquired aetiology. Interventional studies in animal models and clinical studies give strong support to the involvement of each pathway in epilepsy. In this Review, we focus on available knowledge about the pathophysiological features of mTOR signalling and the neuroinflammatory brain response, and their interactions, in epilepsy. We discuss mitigation strategies for each pathway that display therapeutic effects in experimental and clinical epilepsy. A deeper understanding of these interconnected molecular cascades could enhance our strategies for managing epilepsy. This could pave the way for new treatments to fill the gaps in the development of preventative or disease-modifying drugs, thus overcoming the limitations of current symptomatic medications.
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Affiliation(s)
- Teresa Ravizza
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Rossella Di Sapia
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy
| | - Jan Gorter
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands.
| | - Annamaria Vezzani
- Department of Acute Brain and Cardiovascular Injury, Mario Negri Institute for Pharmacological Research IRCCS, Milano, Italy.
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Zhang S, Guo X, Huang W, Xu C. mTORC2: The "Ace in the Hole" for a Broader Control of Epileptic Seizures? Neurosci Bull 2024; 40:677-679. [PMID: 38451388 PMCID: PMC11127853 DOI: 10.1007/s12264-024-01187-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 12/25/2023] [Indexed: 03/08/2024] Open
Affiliation(s)
- Shuo Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, 310006, China
| | - Xiongfeng Guo
- The Second Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Xinhua Hospital); Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Wei Huang
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, 310006, China
| | - Cenglin Xu
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, 310006, China.
- The Second Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Xinhua Hospital); Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
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5
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Cullen ER, Safari M, Mittelstadt I, Weston MC. Hyperactivity of mTORC1- and mTORC2-dependent signaling mediates epilepsy downstream of somatic PTEN loss. eLife 2024; 12:RP91323. [PMID: 38446016 PMCID: PMC10942640 DOI: 10.7554/elife.91323] [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] [Indexed: 03/07/2024] Open
Abstract
Gene variants that hyperactivate PI3K-mTOR signaling in the brain lead to epilepsy and cortical malformations in humans. Some gene variants associated with these pathologies only hyperactivate mTORC1, but others, such as PTEN, PIK3CA, and AKT, hyperactivate both mTORC1- and mTORC2-dependent signaling. Previous work established a key role for mTORC1 hyperactivity in mTORopathies, however, whether mTORC2 hyperactivity contributes is not clear. To test this, we inactivated mTORC1 and/or mTORC2 downstream of early Pten deletion in a new mouse model of somatic Pten loss-of-function (LOF) in the cortex and hippocampus. Spontaneous seizures and epileptiform activity persisted despite mTORC1 or mTORC2 inactivation alone, but inactivating both mTORC1 and mTORC2 simultaneously normalized brain activity. These results suggest that hyperactivity of both mTORC1 and mTORC2 can cause epilepsy, and that targeted therapies should aim to reduce activity of both complexes.
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Affiliation(s)
- Erin R Cullen
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
| | - Mona Safari
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology ResearchRoanokeUnited States
- Translational Biology, Medicine, and Health Graduate ProgramRoanokeUnited States
| | - Isabelle Mittelstadt
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
| | - Matthew C Weston
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology ResearchRoanokeUnited States
- School of Neuroscience, Virginia Polytechnic and State UniversityBlacksburgUnited States
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6
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Cullen ER, Safari M, Mittelstadt I, Weston MC. Hyperactivity of mTORC1 and mTORC2-dependent signaling mediate epilepsy downstream of somatic PTEN loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.18.553856. [PMID: 37645923 PMCID: PMC10462128 DOI: 10.1101/2023.08.18.553856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Gene variants that hyperactivate PI3K-mTOR signaling in the brain lead to epilepsy and cortical malformations in humans. Some gene variants associated with these pathologies only hyperactivate mTORC1, but others, such as PTEN, PIK3CA, and AKT, hyperactivate both mTORC1- and mTORC2-dependent signaling. Previous work established a key role for mTORC1 hyperactivity in mTORopathies, however, whether mTORC2 hyperactivity contributes is not clear. To test this, we inactivated mTORC1 and/or mTORC2 downstream of early Pten deletion in a new model of somatic Pten loss-of-function (LOF) in the cortex and hippocampus. Spontaneous seizures and epileptiform activity persisted despite mTORC1 or mTORC2 inactivation alone, but inactivating both mTORC1 and mTORC2 simultaneously normalized brain activity. These results suggest that hyperactivity of both mTORC1 and mTORC2 can cause epilepsy, and that targeted therapies should aim to reduce activity of both complexes.
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Affiliation(s)
- Erin R. Cullen
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
| | - Mona Safari
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology Research, Roanoke VA, 24016, USA
| | - Isabelle Mittelstadt
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
| | - Matthew C. Weston
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology Research, Roanoke VA, 24016, USA
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg VA, 24060, USA
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7
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Rawat K, Gautam V, Sandhu A, Bhatia A, Saha L. Differential Regulation of Wnt/β-catenin Signaling in Acute and Chronic Epilepsy in Repeated Low Dose Lithium-Pilocarpine Rat Model of Status Epilepticus. Neuroscience 2023; 535:36-49. [PMID: 37913863 DOI: 10.1016/j.neuroscience.2023.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/03/2023]
Abstract
Epilepsy is a chronic neurological complication characterized by unprovoked seizure episodes due to the imbalance between excitatory and inhibitory neurons. The epileptogenesis process has been reported to be involved in chronic epilepsy however, the mechanism underlying epileptogenesis remains unclear. Recent studies have shown the possible involvement of Wnt/β-catenin signaling in the neurogenesis and neuronal reorganization in epileptogenesis. In this study, we used repeated low dose lithium-pilocarpine model of status epilepsy (SE) to study the involvement of Wnt/β-catenin signaling at acute and chronic stages post SE induction. The acute study ranged from day 0 to day 28 post SE induction and the chronic study ranged from day 0 to day 56 post SE induction. Several neurobehavioral parameters and seizure score and seizure frequency was analysed until the end of the study. The proteins involved in the regulation of Wnt/β-catenin signaling and downstream cascading were analysed using western blot and quantitative real-time PCR analysis. The Wnt/β-catenin pathway was found inactive in acute SE, while the same was found activated at the chronic stage. Our findings suggest that the activated Wnt/β-catenin signaling in chronic epilepsy might be the possible mechanism underlying epileptogenesis as indicated by increased neuronal count, increased synaptic density, astrogliosis and apoptosis in chronic epilepsy. These findings can help target the Wnt/β-catenin pathway differentially depending upon the type of epilepsy. The acute stage characterized by SE can be improved by targeting GSK-3β levels and the chronic stage characterized by temporal lobe epilepsy can be improved by targeting β-catenin and disheveled proteins.
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Affiliation(s)
- Kajal Rawat
- Department of Pharmacology, Research Block B, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Vipasha Gautam
- Department of Pharmacology, Research Block B, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Arushi Sandhu
- Department of Pharmacology, Research Block B, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Alka Bhatia
- Department of Experimental Medicine and Biotechnology, Research Block B, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Lekha Saha
- Department of Pharmacology, Research Block B, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India.
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8
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Okoh J, Mays J, Bacq A, Oses-Prieto JA, Tyanova S, Chen CJ, Imanbeyev K, Doladilhe M, Zhou H, Jafar-Nejad P, Burlingame A, Noebels J, Baulac S, Costa-Mattioli M. Targeted suppression of mTORC2 reduces seizures across models of epilepsy. Nat Commun 2023; 14:7364. [PMID: 37963879 PMCID: PMC10645975 DOI: 10.1038/s41467-023-42922-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 10/26/2023] [Indexed: 11/16/2023] Open
Abstract
Epilepsy is a neurological disorder that poses a major threat to public health. Hyperactivation of mTOR complex 1 (mTORC1) is believed to lead to abnormal network rhythmicity associated with epilepsy, and its inhibition is proposed to provide some therapeutic benefit. However, mTOR complex 2 (mTORC2) is also activated in the epileptic brain, and little is known about its role in seizures. Here we discover that genetic deletion of mTORC2 from forebrain neurons is protective against kainic acid-induced behavioral and EEG seizures. Furthermore, inhibition of mTORC2 with a specific antisense oligonucleotide robustly suppresses seizures in several pharmacological and genetic mouse models of epilepsy. Finally, we identify a target of mTORC2, Nav1.2, which has been implicated in epilepsy and neuronal excitability. Our findings, which are generalizable to several models of human seizures, raise the possibility that inhibition of mTORC2 may serve as a broader therapeutic strategy against epilepsy.
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Affiliation(s)
- James Okoh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Jacqunae Mays
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Alexandre Bacq
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Juan A Oses-Prieto
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Stefka Tyanova
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Chien-Ju Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Novartis Inc, Boston, MA, USA
| | - Khalel Imanbeyev
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Marion Doladilhe
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Hongyi Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | | | - Alma Burlingame
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Jeffrey Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Stephanie Baulac
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA.
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA.
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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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10
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Dhamne SC, Modi ME, Gray A, Bonazzi S, Craig L, Bainbridge E, Lalani L, Super CE, Schaeffer S, Capre K, Lubicka D, Liang G, Burdette D, McTighe SM, Gurnani S, Vermudez SAD, Curtis D, Wilson CJ, Hameed MQ, D'Amore A, Rotenberg A, Sahin M. Seizure reduction in TSC2-mutant mouse model by an mTOR catalytic inhibitor. Ann Clin Transl Neurol 2023; 10:1790-1801. [PMID: 37545094 PMCID: PMC10578885 DOI: 10.1002/acn3.51868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 07/14/2023] [Accepted: 07/23/2023] [Indexed: 08/08/2023] Open
Abstract
OBJECTIVE Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder caused by autosomal-dominant pathogenic variants in either the TSC1 or TSC2 gene, and it is characterized by hamartomas in multiple organs, such as skin, kidney, lung, and brain. These changes can result in epilepsy, learning disabilities, and behavioral complications, among others. The mechanistic link between TSC and the mechanistic target of the rapamycin (mTOR) pathway is well established, thus mTOR inhibitors can potentially be used to treat the clinical manifestations of the disorder, including epilepsy. METHODS In this study, we tested the efficacy of a novel mTOR catalytic inhibitor (here named Tool Compound 1 or TC1) previously reported to be more brain-penetrant compared with other mTOR inhibitors. Using a well-characterized hypomorphic Tsc2 mouse model, which displays a translationally relevant seizure phenotype, we tested the efficacy of TC1. RESULTS Our results show that chronic treatment with this novel mTOR catalytic inhibitor (TC1), which affects both the mTORC1 and mTORC2 signaling complexes, reduces seizure burden, and extends the survival of Tsc2 hypomorphic mice, restoring species typical weight gain over development. INTERPRETATION Novel mTOR catalytic inhibitor TC1 exhibits a promising therapeutic option in the treatment of TSC.
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Affiliation(s)
- Sameer C. Dhamne
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Meera E. Modi
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Audrey Gray
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Simone Bonazzi
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Lucas Craig
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Elizabeth Bainbridge
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Lahin Lalani
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Chloe E. Super
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Samantha Schaeffer
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Ketthsy Capre
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Danuta Lubicka
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Guiqing Liang
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Doug Burdette
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | | | - Sarika Gurnani
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Sheryl Anne D. Vermudez
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Daniel Curtis
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | | | - Mustafa Q. Hameed
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Angelica D'Amore
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
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11
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Chen C, Zhu T, Gong L, Hu Z, Wei H, Fan J, Lin D, Wang X, Xu J, Dong X, Wang Y, Xia N, Zeng L, Jiang P, Xie Y. Trpm2 deficiency in microglia attenuates neuroinflammation during epileptogenesis by upregulating autophagy via the AMPK/mTOR pathway. Neurobiol Dis 2023; 186:106273. [PMID: 37648036 DOI: 10.1016/j.nbd.2023.106273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/15/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023] Open
Abstract
Epilepsy is one of the most common neurological disorders. Neuroinflammation involving the activation of microglia and astrocytes constitutes an important and common mechanism in epileptogenesis. Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, non-selective cation channel that plays pathological roles in various inflammation-related diseases. Our previous study demonstrated that Trpm2 knockout exhibits therapeutic effects on pilocarpine-induced glial activation and neuroinflammation. However, whether TRPM2 in microglia and astrocytes plays a common pathogenic role in this process and the underlying molecular mechanisms remained undetermined. Here, we demonstrate a previously unknown role for microglial TRPM2 in epileptogenesis. Trpm2 knockout in microglia attenuated kainic acid (KA)-induced glial activation, inflammatory cytokines production and hippocampal paroxysmal discharges, whereas Trpm2 knockout in astrocytes exhibited no significant effects. Furthermore, we discovered that these therapeutic effects were mediated by upregulated autophagy via the adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in microglia. Thus, our findings highlight an important deleterious role of microglial TRPM2 in temporal lobe epilepsy.
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Affiliation(s)
- Chen Chen
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Tao Zhu
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310030, China
| | - Lifen Gong
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Zhe Hu
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Hao Wei
- Department of Pharmacy, Xuzhou Medical University, 221004 Xuzhou, China
| | - Jianchen Fan
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou 310015, China
| | - Donghui Lin
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Xiaojun Wang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Junyu Xu
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Xinyan Dong
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Yifan Wang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Ningxiao Xia
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Linghui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou 310015, China
| | - Peifang Jiang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China.
| | - Yicheng Xie
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China.
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12
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Yu C, Deng XJ, Xu D. Microglia in epilepsy. Neurobiol Dis 2023; 185:106249. [PMID: 37536386 DOI: 10.1016/j.nbd.2023.106249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/07/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Epilepsy is one of most common chronic neurological disorders, and the antiseizure medications developed by targeting neurocentric mechanisms have not effectively reduced the proportion of patients with drug-resistant epilepsy. Further exploration of the cellular or molecular mechanism of epilepsy is expected to provide new options for treatment. Recently, more and more researches focus on brain network components other than neurons, among which microglia have attracted much attention for their diverse biological functions. As the resident immune cells of the central nervous system, microglia have highly plastic transcription, morphology and functional characteristics, which can change dynamically in a context-dependent manner during the progression of epilepsy. In the pathogenesis of epilepsy, highly reactive microglia interact with other components in the epileptogenic network by performing crucial functions such as secretion of soluble factors and phagocytosis, thus continuously reshaping the landscape of the epileptic brain microenvironment. Indeed, microglia appear to be both pro-epileptic and anti-epileptic under the different spatiotemporal contexts of disease, rendering interventions targeting microglia biologically complex and challenging. This comprehensive review critically summarizes the pathophysiological role of microglia in epileptic brain homeostasis alterations and explores potential therapeutic or modulatory targets for epilepsy targeting microglia.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China.
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13
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Metcalf CS. Watch Out for GATORs: Fasting, Seizures, and Nutrient Sensing. Epilepsy Curr 2023; 23:260-261. [PMID: 37662460 PMCID: PMC10470103 DOI: 10.1177/15357597231176342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023] Open
Abstract
DEPDC5-Dependent mTORC1 Signaling Mechanisms Are Critical for the Anti-Seizure Effects of Acute Fasting Yuskaitis CJ, Modasia JB, Schrötter S, Rossitto LA, Groff KJ, Morici C, Mithal DS, Chakrabarty RP, Chandel NS, Manning BD, Sahin M. Cell Rep. 2022;40(9):111278. doi:10.1016/j.celrep.2022.111278 Caloric restriction and acute fasting are known to reduce seizures but through unclear mechanisms. mTOR signaling has been suggested as a potential mechanism for seizure protection from fasting. We demonstrate that brain mTORC1 signaling is reduced after acute fasting of mice and that neuronal mTORC1 integrates GATOR1 complex-mediated amino acid and tuberous sclerosis complex (TSC)-mediated growth factor signaling. Neuronal mTORC1 is most sensitive to withdrawal of leucine, arginine, and glutamine, which are dependent on DEPDC5, a component of the GATOR1 complex. Metabolomic analysis reveals that Depdc5 neuronal-specific knockout mice are resistant to sensing significant fluctuations in brain amino acid levels after fasting. Depdc5 neuronal-specific knockout mice are resistant to the protective effects of fasting on seizures or seizure-induced death. These results establish that acute fasting reduces seizure susceptibility in a DEPDC5-dependent manner. Modulation of nutrients upstream of GATOR1 and mTORC1 could offer a rational therapeutic strategy for epilepsy treatment.
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14
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Zhao Y, Zhao W, Han Y. Inhibition of mTORC2 improves brain injury in epileptic rats by promoting chaperone-mediated autophagy. Epilepsy Res 2023; 193:107161. [PMID: 37163909 DOI: 10.1016/j.eplepsyres.2023.107161] [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: 01/06/2023] [Revised: 03/22/2023] [Accepted: 05/01/2023] [Indexed: 05/12/2023]
Abstract
Epilepsy can seriously affect children's cognitive and behavioral development. The mechanistic target of rapamycin(mTOR) pathway plays an important role in neurodevelopment and epilepsy, but the mechanism of mechanistic target of rapamycin complex 2 (mTORC2) in epilepsy is still unclear. Here, we compared the similarities and differences of the mechanisms of action of mechanistic target of rapamycin complex 1 (mTORC1) and mTORC2 complex in the pathogenesis of epilepsy. Our research results show that the levels of apoptosis in cortical and hippocampal neurons were upregulated in epileptic rats (F = 32.15, 30.96; both P < 0.01), and epilepsy caused neuronal damage (F = 8.13, 9.43; both P < 0.01). The mTORC2-Akt pathway was activated in the cortex and hippocampus of epileptic rats. Inhibition of mTORC2 resulted in decreased levels of apoptosis and reduced neuronal damage in the cortex and hippocampus of epileptic rats. In the hippocampus, selective inhibition of mTORC2 increased lysosome-associated membrane protein 2 A (LAMP2A) protein expression compared with the control group, and the difference was statistically significant (F = 3.02, P < 0.05). Finally, we concluded that in the hippocampus, selective inhibition of mTORC2 can improve epileptic brain injury in rats by increasing chaperone-mediated autophagy (CMA) levels.
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Affiliation(s)
- Yihan Zhao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Wenying Zhao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ying Han
- Department of Pediatrics, Peking University First Hospital, Beijing, China.
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15
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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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16
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Liu B, Zhang Y, Ren H, Yao Q, Ba J, Luan J, Zhao P, Qin Z, Qi Z. mTOR signaling regulates Zika virus replication bidirectionally through autophagy and protein translation. J Med Virol 2023; 95:e28422. [PMID: 36546404 DOI: 10.1002/jmv.28422] [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: 10/07/2022] [Revised: 12/10/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Zika virus (ZIKV) reemerged in 2016 and attracted much more attention worldwide. To date, the limited knowledge of ZIKV interactions with host cells in the early stages of infection impedes the prevention of viral epidemics and the treatment of ZIKV disease. The mammalian target of rapamycin (mTOR) signaling pathway plays an essential role in the regulation of autophagy and protein synthesis during multiple viral infections. This study aimed to investigate the functional role of mTOR signaling in ZIKV replication in human umbilical vein endothelial cells. Immunoblotting demonstrated that ZIKV infection inhibited mTORC1 signaling, enhancing autophagy but obstructing protein translation. Drugs or siRNA for interfering with mTOR signaling molecules were utilized to demonstrate that AKT/TSC2/mTORC1 signaling was involved in ZIKV infection and that autophagy promoted ZIKV production, but viral protein expression was regulated by mTORC1 signaling. Moreover, confocal microscopy indicated a robust correlation between autophagy and viral RNA transcription. This study clarifies the dual functions of mTOR signaling during ZIKV infection and provides theoretical support for developing potential anti-ZIKV drugs based on mTOR signaling molecules and deeper insights to better understand the mechanism between ZIKV and host cells.
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Affiliation(s)
- Bin Liu
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China.,Naval Medical Center, Naval Medical University, Shanghai, China
| | - Yahui Zhang
- Department of Cardiology, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Hao Ren
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China
| | - Qiufeng Yao
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China
| | - Jianbo Ba
- Naval Medical Center, Naval Medical University, Shanghai, China
| | - Jie Luan
- Naval Medical Center, Naval Medical University, Shanghai, China
| | - Ping Zhao
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China
| | - Zhaoling Qin
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China
| | - Zhongtian Qi
- Department of Microbiology, Naval Medical University, Shanghai Key Laboratory of Medical Biodefense, Shanghai, China
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17
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Zavala-Tecuapetla C, Luna-Munguia H, López-Meraz ML, Cuellar-Herrera M. Advances and Challenges of Cannabidiol as an Anti-Seizure Strategy: Preclinical Evidence. Int J Mol Sci 2022; 23:ijms232416181. [PMID: 36555823 PMCID: PMC9783044 DOI: 10.3390/ijms232416181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/24/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
The use of Cannabis for medicinal purposes has been documented since ancient times, where one of its principal cannabinoids extracted from Cannabis sativa, cannabidiol (CBD), has emerged over the last few years as a promising molecule with anti-seizure potential. Here, we present an overview of recent literature pointing out CBD's pharmacological profile (solubility, metabolism, drug-drug interactions, etc.,), CBD's interactions with multiple molecular targets as well as advances in preclinical research concerning its anti-seizure effect on both acute seizure models and chronic models of epilepsy. We also highlight the recent attention that has been given to other natural cannabinoids and to synthetic derivatives of CBD as possible compounds with therapeutic anti-seizure potential. All the scientific research reviewed here encourages to continue to investigate the probable therapeutic efficacy of CBD and its related compounds not only in epilepsy but also and specially in drug-resistant epilepsy, since there is a dire need for new and effective drugs to treat this disease.
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Affiliation(s)
- Cecilia Zavala-Tecuapetla
- Laboratory of Physiology of Reticular Formation, National Institute of Neurology and Neurosurgery, Insurgentes Sur 3877, La Fama, Mexico City 14269, Mexico
- Correspondence:
| | - Hiram Luna-Munguia
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, Queretaro 76230, Mexico
| | - María-Leonor López-Meraz
- Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Luis Castelazo Ayala s/n, Col. Industrial Ánimas, Xalapa 91190, Mexico
| | - Manola Cuellar-Herrera
- Epilepsy Clinic, Hospital General de México Dr. Eduardo Liceaga, Dr. Balmis 148, Doctores, Mexico City 06720, Mexico
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18
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Maurer-Morelli CV, de Vasconcellos JF, Bruxel EM, Rocha CS, do Canto AM, Tedeschi H, Yasuda CL, Cendes F, Lopes-Cendes I. Gene expression profile suggests different mechanisms underlying sporadic and familial mesial temporal lobe epilepsy. Exp Biol Med (Maywood) 2022; 247:2233-2250. [PMID: 36259630 PMCID: PMC9899983 DOI: 10.1177/15353702221126666] [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] [Indexed: 02/04/2023] Open
Abstract
Most patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) have hippocampal sclerosis on the postoperative histopathological examination. Although most patients with MTLE do not refer to a family history of the disease, familial forms of MTLE have been reported. We studied surgical specimens from patients with MTLE who had epilepsy surgery for medically intractable seizures. We assessed and compared gene expression profiles of the tissue lesion found in patients with familial MTLE (n = 3) and sporadic MTLE (n = 5). In addition, we used data from control hippocampi obtained from a public database (n = 7). We obtained expression profiles using the Human Genome U133 Plus 2.0 (Affymetrix) microarray platform. Overall, the molecular profile identified in familial MTLE differed from that in sporadic MTLE. In the tissue of patients with familial MTLE, we found an over-representation of the biological pathways related to protein response, mRNA processing, and synaptic plasticity and function. In sporadic MTLE, the gene expression profile suggests that the inflammatory response is highly activated. In addition, we found enrichment of gene sets involved in inflammatory cytokines and mediators and chemokine receptor pathways in both groups. However, in sporadic MTLE, we also found enrichment of epidermal growth factor signaling, prostaglandin synthesis and regulation, and microglia pathogen phagocytosis pathways. Furthermore, based on the gene expression signatures, we identified different potential compounds to treat patients with familial and sporadic MTLE. To our knowledge, this is the first study assessing the mRNA profile in surgical tissue obtained from patients with familial MTLE and comparing it with sporadic MTLE. Our results clearly show that, despite phenotypic similarities, both forms of MTLE present distinct molecular signatures, thus suggesting different underlying molecular mechanisms that may require distinct therapeutic approaches.
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Affiliation(s)
- Claudia V Maurer-Morelli
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Jaira F de Vasconcellos
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Department of Biology, James Madison
University, Harrisonburg, VA 22807, USA
| | - Estela M Bruxel
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Cristiane S Rocha
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Amanda M do Canto
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Helder Tedeschi
- Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Clarissa L Yasuda
- Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Fernando Cendes
- Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Iscia Lopes-Cendes
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Iscia Lopes-Cendes.
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19
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Patodia S, Lim YM, Chung F, Stylianou I, El Hachami H, Thom M. Cortical neuronal hypertrophy and mTOR pathway activation in CAN regions in SUDEP. Epilepsia 2022; 63:2427-2438. [PMID: 35716147 PMCID: PMC9795893 DOI: 10.1111/epi.17335] [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: 02/10/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Dysfunctional connectivity and preexisting structural abnormalities of central autonomic network (CAN) regions have been shown on magnetic resonance imaging (MRI) in sudden unexpected death in epilepsy (SUDEP) and may be mechanistically relevant. In a previous postmortem study we reported increased microglia in CAN regions, including the superior temporal gyrus (STG) in SUDEP. In this current study we investigated mammalian target of rapamycin (mTOR) pathway activation and neuronal c-Fos activation in CAN regions in SUDEP compared to control groups. METHODS In a series of 59 postmortem cases (SUDEP, n = 26; epilepsy controls [EPCs], n = 14; and nonepilepsy controls [NECs], n = 19), we quantified pS6-240/4, pS6-235/6 (markers of mTOR activation) and c-Fos neuronal densities and labeling index in the STG, anterior cingulate, insula, frontobasal, and pulvinar regions using immunohistochemistry with whole-slide automated image analysis. RESULTS Significantly more pS6-positive neurons were present in the STG in cases with a history of recent seizures prior to death and also in SUDEP compared to other cause of death groups. No differences were noted for c-Fos neuronal labeling in any region between cause of death groups. Cortical neuronal hypertrophy in the STG was observed in some SUDEP cases and associated with pS6-240/4 expression. pS6-235/6 highlighted neuronal intranuclear inclusions, mainly in SUDEP cases and in the STG region. SIGNIFICANCE Neuronal labeling for pS6 in the STG correlated with both seizure activity in the period prior to death and SUDEP. Further investigations are required to explore the significance of this region in terms of autonomic network dysfunction that may increase the vulnerability for SUDEP.
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Affiliation(s)
- Smriti Patodia
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Yau Mun Lim
- Department of NeurodegenerationUCL Queen Square Institute of NeurologyLondonUK
| | - Freda Chung
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Irene Stylianou
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Hanaa El Hachami
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
| | - Maria Thom
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
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20
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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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Gourmaud S, Stewart DA, Irwin DJ, Roberts N, Barbour AJ, Eberwine G, O’Brien WT, Vassar R, Talos DM, Jensen FE. The role of mTORC1 activation in seizure-induced exacerbation of Alzheimer's disease. Brain 2022; 145:324-339. [PMID: 34264340 PMCID: PMC9126019 DOI: 10.1093/brain/awab268] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
The risk of seizures is 10-fold higher in patients with Alzheimer's disease than the general population, yet the mechanisms underlying this susceptibility and the effects of these seizures are poorly understood. To elucidate the proposed bidirectional relationship between Alzheimer's disease and seizures, we studied human brain samples (n = 34) from patients with Alzheimer's disease and found that those with a history of seizures (n = 14) had increased amyloid-β and tau pathology, with upregulation of the mechanistic target of rapamycin (mTOR) pathway, compared with patients without a known history of seizures (n = 20). To establish whether seizures accelerate the progression of Alzheimer's disease, we induced chronic hyperexcitability in the five times familial Alzheimer's disease mouse model by kindling with the chemoconvulsant pentylenetetrazol and observed that the mouse model exhibited more severe seizures than the wild-type. Furthermore, kindled seizures exacerbated later cognitive impairment, Alzheimer's disease neuropathology and mTOR complex 1 activation. Finally, we demonstrated that the administration of the mTOR inhibitor rapamycin following kindled seizures rescued enhanced remote and long-term memory deficits associated with earlier kindling and prevented seizure-induced increases in Alzheimer's disease neuropathology. These data demonstrated an important link between chronic hyperexcitability and progressive Alzheimer's disease pathology and suggest a mechanism whereby rapamycin may serve as an adjunct therapy to attenuate progression of the disease.
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Affiliation(s)
- Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Roberts
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Grace Eberwine
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William T O’Brien
- Neurobehavior Testing Core, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Vassar
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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22
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Park S, Zhu J, Jeong KH, Kim WJ. Adjudin prevents neuronal damage and neuroinflammation via inhibiting mTOR activation against pilocarpine-induced status epilepticus. Brain Res Bull 2022; 182:80-89. [PMID: 35182690 DOI: 10.1016/j.brainresbull.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/23/2022] [Accepted: 02/14/2022] [Indexed: 11/02/2022]
Abstract
Inflammatory responses in the brain play an etiological role in the development of epilepsy, suggesting that finding novel molecules for controlling neuroinflammation may have clinical value in developing the disease-modifying strategies for epileptogenesis. Adjudin, a multi-functional small molecule compound, has pleiotropic effects, including anti-inflammatory properties. In the present study, we aimed to investigate the effects of adjudin on pilocarpine-induced status epilepticus (SE) and its role in the regulation of reactive gliosis and neuroinflammation. SE was induced in male C57BL/6 mice that were then treated with adjudin (50mg/kg) for 3 days after SE onset. Immunofluorescence staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and western blot analysis were used to evaluate the effects of adjudin treatment in the hippocampus after SE. Our results showed that adjudin treatment significantly mitigated apoptotic cell death in the hippocampus after SE onset. Moreover, adjudin treatment suppressed SE-induced glial activation and activation of mammalian target of rapamycin signaling in the hippocampus. Concomitantly, adjudin treatment significantly reduced SE-induced inflammatory processes, as confirmed by changes in the expression of inflammatory mediators such as tumor necrosis factor-α, interleukin-1β, and arginase-1. In conclusion, these findings suggest that adjudin may serve as a potential neuroprotective agent for preventing pathological mechanisms implicated in epileptogenesis.
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Affiliation(s)
- Soojin Park
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, Seoul, Republic of Korea
| | - Jing Zhu
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, Seoul, Republic of Korea
| | - Kyoung Hoon Jeong
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea; Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Won-Joo Kim
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
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23
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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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Ma KG, Hu HB, Zhou JS, Ji C, Yan QS, Peng SM, Ren LD, Yang BN, Xiao XL, Ma YB, Wu F, Si KW, Wu XL, Liu JX. Neuronal Glypican4 promotes mossy fiber sprouting through the mTOR pathway after pilocarpine-induced status epilepticus in mice. Exp Neurol 2021; 347:113918. [PMID: 34748756 DOI: 10.1016/j.expneurol.2021.113918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 02/07/2023]
Abstract
In temporal lobe epilepsy (TLE), abnormal axon guidance and synapse formation lead to sprouting of mossy fibers in the hippocampus, which is one of the most consistent pathological findings in patients and animal models with TLE. Glypican 4 (Gpc4) belongs to the heparan sulfate proteoglycan family, which play an important role in axon guidance and excitatory synapse formation. However, the role of Gpc4 in the development of mossy fibers sprouting (MFS) and its underlying mechanism remain unknown. Using a pilocarpine-induced mice model of epilepsy, we showed that Gpc4 expression was significantly increased in the stratum granulosum of the dentate gyrus at 1 week after status epilepticus (SE). Using Gpc4 overexpression or Gpc4 shRNA lentivirus to regulate the Gpc4 level in the dentate gyrus, increased or decreased levels of netrin-1, SynI, PSD-95, and Timm score were observed in the dentate gyrus, indicating a crucial role of Gpc4 in modulating the development of functional MFS. The observed effects of Gpc4 on MFS were significantly antagonized when mice were treated with L-leucine or rapamycin, an agonist or antagonist of the mammalian target of rapamycin (mTOR) signal, respectively, demonstrating that mTOR pathway is an essential requirement for Gpc4-regulated MFS. Additionally, the attenuated spontaneous recurrent seizures (SRSs) were observed during chronic stage of the disease by suppressing the Gpc4 expression after SE. Altogether, our findings demonstrate a novel control of neuronal Gpc4 on the development of MFS through the mTOR pathway after pilocarpine-induced SE. Our results also strongly suggest that Gpc4 may serve as a promising target for antiepileptic studies.
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Affiliation(s)
- Kai-Ge Ma
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 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 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 710061, China
| | - Chao Ji
- Qide College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Qi-Sheng Yan
- Qide College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Si-Ming Peng
- Zonglian College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Lan-Dong Ren
- Zonglian College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Bing-Nan Yang
- Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, 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 710061, China; Institute of Neuroscience, Translational Medicine Institute, 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 710061, China
| | - Feng Wu
- Center of Teaching and Experiment for Medical Post Graduates, 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
| | - 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 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 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 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China.
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25
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Łukawski K, Czuczwar SJ. Understanding mechanisms of drug resistance in epilepsy and strategies for overcoming it. Expert Opin Drug Metab Toxicol 2021; 17:1075-1090. [PMID: 34310255 DOI: 10.1080/17425255.2021.1959912] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The present evidence indicates that approximately 70% of patients with epilepsy can be successfully treated with antiepileptic drugs (AEDs). A significant proportion of patients are not under sufficient control, and pharmacoresistant epilepsy is clearly associated with poor quality of life and increased morbidity and mortality. There is a great need for newer therapeutic options able to reduce the percentage of drug-resistant patients. AREAS COVERED A number of hypotheses trying to explain the development of pharmacoresistance have been put forward. These include: target hypothesis (altered AED targets), transporter (overexpression of brain efflux transporters), pharmacokinetic (overexpression of peripheral efflux transporters in the intestine or kidneys), intrinsic severity (initial high seizure frequency), neural network (aberrant networks), and gene variant hypothesis (genetic polymorphisms). EXPERT OPINION A continuous search for newer AEDs or among non-AEDs (blockers of efflux transporters, interleukin antagonists, cyclooxygenase inhibitors, mTOR inhibitors, angiotensin II receptor antagonists) may provide efficacious drugs for the management of drug-resistant epilepsy. Also, combinations of AEDs exerting synergy in preclinical and clinical studies (for instance, lamotrigine + valproate, levetiracetam + valproate, topiramate + carbamazepine) might be of importance in this respect. Preclinically antagonistic combinations must be avoided (lamotrigine + carbamazepine, lamotrigine + oxcarbazepine).
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Affiliation(s)
- Krzysztof Łukawski
- Department of Physiopathology, Institute of Rural Health, Lublin, Poland.,Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
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26
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The Role of KRAS Mutations in Cortical Malformation and Epilepsy Surgery: A Novel Report of Nevus Sebaceous Syndrome and Review of the Literature. Brain Sci 2021; 11:brainsci11060793. [PMID: 34208656 PMCID: PMC8234150 DOI: 10.3390/brainsci11060793] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/27/2021] [Accepted: 06/11/2021] [Indexed: 12/12/2022] Open
Abstract
The rare nevus sebaceous (NS) syndrome (NSS) includes cortical malformations and drug-resistant epilepsy. Somatic RAS-pathway genetic variants are pathogenetic in NS, but not yet described within the brain of patients with NSS. We report on a 5-year-old boy with mild psychomotor delay. A brown-yellow linear skin lesion suggestive of NS in the left temporo-occipital area was evident at birth. Epileptic spasms presented at aged six months. EEG showed continuous left temporo-occipital epileptiform abnormalities. Brain MRI revealed a similarly located diffuse cortical malformation with temporal pole volume reduction and a small hippocampus. We performed a left temporo-occipital resection with histopathological diagnosis of focal cortical dysplasia type Ia in the occipital region and hippocampal sclerosis type 1. Three years after surgery, he is seizure-and drug-free (Engel class Ia) and showed cognitive improvement. Genetic examination of brain and skin specimens revealed the c.35G > T (p.Gly12Val) KRAS somatic missense mutation. Literature review suggests epilepsy surgery in patients with NSS is highly efficacious, with 73% probability of seizure freedom. The few histological analyses reported evidenced disorganized cortex, occasionally with cytomegalic neurons. This is the first reported association of a KRAS genetic variant with cortical malformations associated with epilepsy, and suggests a possible genetic substrate for hippocampal sclerosis.
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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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28
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Hodges SL, Womble PD, Kwok EM, Darner AM, Senger SS, Binder MS, Faust AM, Condon SM, Nolan SO, Quintero SI, Lugo JN. Rapamycin, but not minocycline, significantly alters ultrasonic vocalization behavior in C57BL/6J pups in a flurothyl seizure model. Behav Brain Res 2021; 410:113317. [PMID: 33910029 DOI: 10.1016/j.bbr.2021.113317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 02/24/2021] [Accepted: 04/21/2021] [Indexed: 12/11/2022]
Abstract
Epilepsy is one of the most common neurological disorders, with individuals having an increased susceptibility of seizures in the first few years of life, making children at risk of developing a multitude of cognitive and behavioral comorbidities throughout development. The present study examined the role of PI3K/Akt/mTOR pathway activity and neuroinflammatory signaling in the development of autistic-like behavior following seizures in the neonatal period. Male and female C57BL/6J mice were administered 3 flurothyl seizures on postnatal (PD) 10, followed by administration of minocycline, the mTOR inhibitor rapamycin, or a combined treatment of both therapeutics. On PD12, isolation-induced ultrasonic vocalizations (USVs) of mice were examined to determine the impact of seizures and treatment on communicative behaviors, a component of the autistic-like phenotype. Seizures on PD10 increased the quantity of USVs in female mice and reduced the amount of complex call types emitted in males compared to controls. Inhibition of mTOR with rapamycin significantly reduced the quantity and duration of USVs in both sexes. Changes in USVs were associated with increases in mTOR and astrocyte levels in male mice, however, three PD10 seizures did not result in enhanced proinflammatory cytokine expression in either sex. Beyond inhibition of mTOR activity by rapamycin, both therapeutics did not demonstrate beneficial effects. These findings emphasize the importance of differences that may exist across preclinical seizure models, as three flurothyl seizures did not induce as drastic of changes in mTOR activity or inflammation as observed in other rodent models.
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Affiliation(s)
- Samantha L Hodges
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA.
| | - Paige D Womble
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Eliesse M Kwok
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Alyssa M Darner
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Savannah S Senger
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Matthew S Binder
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Amanda M Faust
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Siena M Condon
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Suzanne O Nolan
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Saul I Quintero
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA
| | - Joaquin N Lugo
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA; Department of Psychology and Neuroscience, Baylor University, Waco, TX, 76798, USA; Department of Biology, Baylor University, Waco, TX, 76798, USA
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29
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Inhibition of AKT/GSK3β/CREB Pathway Improves the Responsiveness to AMPA Receptor Antagonists by Regulating GRIA1 Surface Expression in Chronic Epilepsy Rats. Biomedicines 2021; 9:biomedicines9040425. [PMID: 33919872 PMCID: PMC8103519 DOI: 10.3390/biomedicines9040425] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 12/15/2022] Open
Abstract
α-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) has been reported as one of the targets for treatment of epilepsy. Although maladaptive regulation of surface expression of glutamate ionotropic receptor AMPA type subunit 1 (GRIA1) subunit is relevant to the responsiveness to AMPAR antagonists (perampanel and GYKI 52466) in LiCl-pilocarpine-induced chronic epilepsy rats, the underlying mechanisms of refractory seizures to AMPAR antagonists have yet been unclear. In the present study, we found that both AMPAR antagonists restored the up-regulations of GRIA1 surface expression and Src family-mediated glycogen synthase kinase 3β (GSK3β)-Ca2+/cAMP response element-binding protein (CREB) phosphorylations to control levels in responders (whose seizure activities were responsive to AMPAR) but not non-responders (whose seizure activities were uncontrolled by AMPAR antagonists). In addition, 3-chloroacetyl indole (3CAI, an AKT inhibitor) co-treatment attenuated spontaneous seizure activities in non-responders, accompanied by reductions in AKT/GSK3β/CREB phosphorylations and GRIA1 surface expression. Although AMPAR antagonists reduced GRIA2 tyrosine (Y) phosphorylations in responders, they did not affect GRIA2 surface expression and protein interacting with C kinase 1 (PICK1) protein level in both responders and non-responders. Therefore, our findings suggest that dysregulation of AKT/GSK3β/CREB-mediated GRIA1 surface expression may be responsible for refractory seizures in non-responders, and that this pathway may be a potential target to improve the responsiveness to AMPAR antagonists.
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Lovisari F, Roncon P, Soukoupova M, Paolone G, Labasque M, Ingusci S, Falcicchia C, Marino P, Johnson M, Rossetti T, Petretto E, Leclercq K, Kaminski RM, Moyon B, Webster Z, Simonato M, Zucchini S. Implication of sestrin3 in epilepsy and its comorbidities. Brain Commun 2021; 3:fcaa130. [PMID: 33758823 PMCID: PMC7966953 DOI: 10.1093/braincomms/fcaa130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 06/30/2020] [Accepted: 07/13/2020] [Indexed: 12/21/2022] Open
Abstract
Epilepsy is a serious neurological disorder affecting about 1% of the population worldwide. Epilepsy may arise as a result of acquired brain injury, or as a consequence of genetic predisposition. To date, genome-wide association studies and exome sequencing approaches have provided limited insights into the mechanisms of acquired brain injury. We have previously reported a pro-epileptic gene network, which is conserved across species, encoding inflammatory processes and positively regulated by sestrin3 (SESN3). In this study, we investigated the phenotype of SESN3 knock-out rats in terms of susceptibility to seizures and observed a significant delay in status epilepticus onset in SESN3 knock-out compared to control rats. This finding confirms previous in vitro and in vivo evidence indicating that SESN3 may favour occurrence and/or severity of seizures. We also analysed the phenotype of SESN3 knock-out rats for common comorbidities of epilepsy, i.e., anxiety, depression and cognitive impairment. SESN3 knock-out rats proved less anxious compared to control rats in a selection of behavioural tests. Taken together, the present results suggest that SESN3 may regulate mechanisms involved in the pathogenesis of epilepsy and its comorbidities.
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Affiliation(s)
- Francesca Lovisari
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Paolo Roncon
- Division of Neuroscience, School of Medicine, University Vita-Salute San Raffaele, Milan, Italy
| | - Marie Soukoupova
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Giovanna Paolone
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Marilyne Labasque
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Selene Ingusci
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Chiara Falcicchia
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | - Pietro Marino
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
| | | | | | - Enrico Petretto
- Programme in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore.,MRC London Institute of Medical Sciences (LMC), Imperial College London, UK
| | - Karine Leclercq
- Neuroscience TA, UCB Biopharma SPRL, Braine l'Alleud, Belgium
| | | | - Ben Moyon
- Es Cell and Transgenics, Medical Research Council, Imperial College London, UK
| | - Zoe Webster
- Es Cell and Transgenics, Medical Research Council, Imperial College London, UK
| | - Michele Simonato
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy.,Division of Neuroscience, School of Medicine, University Vita-Salute San Raffaele, Milan, Italy
| | - Silvia Zucchini
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, Italy
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Okada M. Can rodent models elucidate the pathomechanisms of genetic epilepsy? Br J Pharmacol 2021; 179:1620-1639. [PMID: 33689168 PMCID: PMC9291625 DOI: 10.1111/bph.15443] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/03/2021] [Accepted: 03/04/2021] [Indexed: 12/31/2022] Open
Abstract
Autosomal dominant sleep-related hypermotor epilepsy (ADSHE; previously autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE), originally reported in 1994, was the first distinct genetic epilepsy shown to be caused by CHNRA4 mutation. In the past two decades, we have identified several functional abnormalities of mutant ion channels and their associated transmissions using several experiments involving single-cell and genetic animal (rodent) models. Currently, epileptologists understand that functional abnormalities underlying epileptogenesis/ictogenesis in humans and rodents are more complicated than previously believed and that the function of mutant molecules alone cannot contribute to the development of epileptogenesis/ictogenesis but play important roles in the development of epileptogenesis/ictogenesis through formation of abnormalities in various other transmission systems before epilepsy onset. Based on our recent findings using genetic rat ADSHE models, harbouring Chrna4 mutant, corresponding to human S284L-mutant CRHNA4, this review proposes a hypothesis associated with tripartite synaptic transmission in ADSHE pathomechanisms induced by mutant ACh receptors.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu, Japan
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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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33
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Insights into Potential Targets for Therapeutic Intervention in Epilepsy. Int J Mol Sci 2020; 21:ijms21228573. [PMID: 33202963 PMCID: PMC7697405 DOI: 10.3390/ijms21228573] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.
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Age-Dependent and Sleep/Seizure-Induced Pathomechanisms of Autosomal Dominant Sleep-Related Hypermotor Epilepsy. Int J Mol Sci 2020; 21:ijms21218142. [PMID: 33143372 PMCID: PMC7662760 DOI: 10.3390/ijms21218142] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 10/29/2020] [Indexed: 12/22/2022] Open
Abstract
The loss-of-function S284L-mutant α4 subunit of the nicotinic acetylcholine receptor (nAChR) is considered to contribute to the pathomechanism of autosomal dominant sleep-related hypermotor epilepsy (ADSHE); however, the age-dependent and sleep-related pathomechanisms of ADSHE remain to be clarified. To explore the age-dependent and sleep-induced pathomechanism of ADSHE, the present study determined the glutamatergic transmission abnormalities associated with α4β2-nAChR and the astroglial hemichannel in the hyperdirect and corticostriatal pathways of ADSHE model transgenic rats (S286L-TG) bearing the rat S286L-mutant Chrna4 gene corresponding to the human S284L-mutant CHRNA4 gene of ADSHE, using multiprobe microdialysis and capillary immunoblotting analyses. This study could not detect glutamatergic transmission in the corticostriatal pathway from the orbitofrontal cortex (OFC) to the striatum. Before ADSHE onset (four weeks of age), functional abnormalities of glutamatergic transmission compared to the wild-type in the cortical hyperdirect pathway, from OFC to the subthalamic nucleus (STN) in S286L-TG, could not be detected. Conversely, after ADSHE onset (eight weeks of age), glutamatergic transmission in the hyperdirect pathway of S286L-TG was enhanced compared to the wild-type. Notably, enhanced glutamatergic transmission of S286L-TG was revealed by hemichannel activation in the OFC. Expression of connexin43 (Cx43) in the OFC of S286L-TG was upregulated after ADSHE onset but was almost equal to the wild-type prior to ADSHE onset. Differences in the expression of phosphorylated protein kinase B (pAkt) before ADSHE onset between the wild-type and S286L-TG were not observed; however, after ADSHE onset, pAkt was upregulated in S286L-TG. Conversely, the expression of phosphorylated extracellular signal-regulated kinase (pErk) was already upregulated before ADSHE onset compared to the wild-type. Both before and after ADSHE onset, subchronic nicotine administration decreased and did not affect the both expression of Cx43 and pErk of respective wild-type and S286L-TG, whereas the pAkt expression of both the wild-type and S286L-TG was increased by nicotine. Cx43 expression in the plasma membrane of the primary cultured astrocytes of the wild-type was increased by elevation of the extracellular K+ level (higher than 10 mM), and the increase in Cx43 expression in the plasma membrane required pErk functions. These observations indicate that a combination of functional abnormalities, GABAergic disinhibition, and upregulated pErk induced by the loss-of-function S286L-mutant α4β2-nAChR contribute to the age-dependent and sleep-induced pathomechanism of ADSHE via the upregulation/hyperactivation of the Cx43 hemichannels.
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Novel brain permeant mTORC1/2 inhibitors are as efficacious as rapamycin or everolimus in mouse models of acquired partial epilepsy and tuberous sclerosis complex. Neuropharmacology 2020; 180:108297. [PMID: 32890589 DOI: 10.1016/j.neuropharm.2020.108297] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/27/2020] [Accepted: 09/01/2020] [Indexed: 12/24/2022]
Abstract
Mechanistic target of rapamycin (mTOR) regulates cell proliferation, growth and survival, and is activated in cancer and neurological disorders, including epilepsy. The rapamycin derivative ("rapalog") everolimus, which allosterically inhibits the mTOR pathway, is approved for the treatment of partial epilepsy with spontaneous recurrent seizures (SRS) in individuals with tuberous sclerosis complex (TSC). In contrast to the efficacy in TSC, the efficacy of rapalogs on SRS in other types of epilepsy is equivocal. Furthermore, rapalogs only poorly penetrate into the brain and are associated with peripheral adverse effects, which may compromise their therapeutic efficacy. Here we compare the antiseizure efficacy of two novel, brain-permeable ATP-competitive and selective mTORC1/2 inhibitors, PQR620 and PQR626, and the selective dual pan-PI3K/mTORC1/2 inhibitor PQR530 in two mouse models of chronic epilepsy with SRS, the intrahippocampal kainate (IHK) mouse model of acquired temporal lobe epilepsy and Tsc1GFAP CKO mice, a well-characterized mouse model of epilepsy in TSC. During prolonged treatment of IHK mice with rapamycin, everolimus, PQR620, PQR626, or PQR530; only PQR620 exerted a transient antiseizure effect on SRS, at well tolerated doses whereas the other compounds were ineffective. In contrast, all of the examined compounds markedly suppressed SRS in Tsc1GFAP CKO mice during chronic treatment at well tolerated doses. Thus, against our expectation, no clear differences in antiseizure efficacy were found across the three classes of mTOR inhibitors examined in mouse models of genetic and acquired epilepsies. The main advantage of the novel 1,3,5-triazine derivatives is their excellent tolerability compared to rapalogs, which would favor their development as new therapies for TORopathies such as TSC.
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Microglial mTOR is Neuronal Protective and Antiepileptogenic in the Pilocarpine Model of Temporal Lobe Epilepsy. J Neurosci 2020; 40:7593-7608. [PMID: 32868461 DOI: 10.1523/jneurosci.2754-19.2020] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 08/05/2020] [Accepted: 08/24/2020] [Indexed: 01/01/2023] Open
Abstract
Excessive activation of mammalian target of rapamycin (mTOR) signaling is epileptogenic in genetic epilepsy. However, the exact role of microglial mTOR in acquired epilepsy remains to be clarified. In the present study, we found that mTOR is strongly activated in microglia following excitatory injury elicited by status epilepticus. To determine the role of microglial mTOR signaling in excitatory injury and epileptogenesis, we generated mice with restrictive deletion of mTOR in microglia. Both male and female mice were used in the present study. We found that mTOR-deficient microglia lost their typical proliferative and inflammatory responses to excitatory injury, whereas the proliferation of astrocytes was preserved. In addition, mTOR-deficient microglia did not effectively engulf injured/dying neurons. More importantly, microglial mTOR-deficient mice displayed increased neuronal loss and developed more severe spontaneous seizures. These findings suggest that microglial mTOR plays a protective role in mitigating neuronal loss and attenuating epileptogenesis in the excitatory injury model of epilepsy.SIGNIFICANCE STATEMENT The mammalian target of rapamycin (mTOR) pathway is strongly implicated in epilepsy. However, the effect of mTOR inhibitors in preclinical models of acquired epilepsy is inconsistent. The broad presence of mTOR signaling in various brain cells could prevent mTOR inhibitors from achieving a net therapeutic effect. This conundrum has spurred further investigation of the cell type-specific effects of mTOR signaling in the CNS. We found that activation of microglial mTOR is antiepileptogenic. Thus, microglial mTOR activation represents a novel antiepileptogenic route that appears to parallel the proepileptogenic route of neuronal mTOR activation. This may explain why the net effect of mTOR inhibitors is paradoxical in the acquired models of epilepsy. Our findings could better guide the use of mTOR inhibitors in preventing acquired epilepsy.
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37
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Gourmaud S, Shou H, Irwin DJ, Sansalone K, Jacobs LM, Lucas TH, Marsh ED, Davis KA, Jensen FE, Talos DM. Alzheimer-like amyloid and tau alterations associated with cognitive deficit in temporal lobe epilepsy. Brain 2020; 143:191-209. [PMID: 31834353 DOI: 10.1093/brain/awz381] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 10/08/2019] [Accepted: 10/17/2019] [Indexed: 01/27/2023] Open
Abstract
Temporal lobe epilepsy represents a major cause of drug-resistant epilepsy. Cognitive impairment is a frequent comorbidity, but the mechanisms are not fully elucidated. We hypothesized that the cognitive impairment in drug-resistant temporal lobe epilepsy could be due to perturbations of amyloid and tau signalling pathways related to activation of stress kinases, similar to those observed in Alzheimer's disease. We examined these pathways, as well as amyloid-β and tau pathologies in the hippocampus and temporal lobe cortex of drug-resistant temporal lobe epilepsy patients who underwent temporal lobe resection (n = 19), in comparison with age- and region-matched samples from neurologically normal autopsy cases (n = 22). Post-mortem temporal cortex samples from Alzheimer's disease patients (n = 9) were used as positive controls to validate many of the neurodegeneration-related antibodies. Western blot and immunohistochemical analysis of tissue from temporal lobe epilepsy cases revealed increased phosphorylation of full-length amyloid precursor protein and its associated neurotoxic cleavage product amyloid-β*56. Pathological phosphorylation of two distinct tau species was also increased in both regions, but increases in amyloid-β1-42 peptide, the main component of amyloid plaques, were restricted to the hippocampus. Furthermore, several major stress kinases involved in the development of Alzheimer's disease pathology were significantly activated in temporal lobe epilepsy brain samples, including the c-Jun N-terminal kinase and the protein kinase R-like endoplasmic reticulum kinase. In temporal lobe epilepsy cases, hippocampal levels of phosphorylated amyloid precursor protein, its pro-amyloidogenic processing enzyme beta-site amyloid precursor protein cleaving enzyme 1, and both total and hyperphosphorylated tau expression, correlated with impaired preoperative executive function. Our study suggests that neurodegenerative and stress-related processes common to those observed in Alzheimer's disease may contribute to cognitive impairment in drug-resistant temporal lobe epilepsy. In particular, we identified several stress pathways that may represent potential novel therapeutic targets.
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Affiliation(s)
- Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Haochang Shou
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly Sansalone
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leah M Jacobs
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Timothy H Lucas
- Department of Neurosurgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Eric D Marsh
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Division of Child Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kathryn A Davis
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Cho S, Park E, Telliyan T, Baker A, Reid AY. Zebrafish model of posttraumatic epilepsy. Epilepsia 2020; 61:1774-1785. [DOI: 10.1111/epi.16589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 06/02/2020] [Accepted: 06/02/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Sung‐Joon Cho
- Division of Fundamental Neurobiology Krembil Research Institute University Health Network Toronto Ontario Canada
- Collaborative Program in Neuroscience University of Toronto Toronto Ontario Canada
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Eugene Park
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Tamar Telliyan
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Andrew Baker
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
- Department of Anesthesia and Surgery University of Toronto Toronto Ontario Canada
| | - Aylin Y. Reid
- Division of Fundamental Neurobiology Krembil Research Institute University Health Network Toronto Ontario Canada
- Department of Medicine University of Toronto Toronto Ontario Canada
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Shen HY, Weltha L, Cook JM, Gesese R, Omi W, Baer SB, Rose RM, Reemmer J, Boison D. Sarcosine Suppresses Epileptogenesis in Rats With Effects on Hippocampal DNA Methylation. Front Mol Neurosci 2020; 13:97. [PMID: 32581708 PMCID: PMC7291815 DOI: 10.3389/fnmol.2020.00097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/06/2020] [Indexed: 12/14/2022] Open
Abstract
Epileptogenesis is a common consequence of brain insults, however, the prevention or delay of the epileptogenic process remains an important unmet medical challenge. Overexpression of glycine transporter 1 (GlyT1) is proposed as a pathological hallmark in the hippocampus of patients with temporal lobe epilepsy (TLE), and we previously demonstrated in rodent epilepsy models that augmentation of glycine suppressed chronic seizures and altered acute seizure thresholds. In the present study we evaluated the effect of the GlyT1 inhibitor, sarcosine (aka N-methylglycine), on epileptogenesis and also investigated possible mechanisms. We developed a modified rapid kindling model of epileptogenesis in rats combined with seizure score monitoring to evaluate the antiepileptogenic effect of sarcosine. We used immunohistochemistry and Western blot analysis for the evaluation of GlyT1 expression and epigenetic changes of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in the epileptogenic hippocampi of rats, and further evaluated expression changes in enzymes involved in the regulation of DNA methylation, ten-eleven translocation methylcytosine dioxygenase 1 (TET1), DNA-methyltransferase 1 (DNMT1), and DNMT3a. Our results demonstrated: (i) experimental evidence that sarcosine (3 g/kg, i.p. daily) suppressed kindling epileptogenesis in rats; (ii) the sarcosine-induced antiepileptogenic effect was accompanied by a suppressed hippocampal GlyT1 expression as well as a reduction of hippocampal 5mC levels and a corresponding increase in 5hmC; and (iii) sarcosine treatment caused differential expression changes of TET1 and DNMTs. Together, these findings suggest that sarcosine has unprecedented disease-modifying properties in a kindling model of epileptogenesis in rats, which was associated with altered hippocampal DNA methylation. Thus, manipulation of the glycine system is a potential therapeutic approach to attenuate the development of epilepsy.
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Affiliation(s)
- Hai-Ying Shen
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Landen Weltha
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - John M Cook
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Raey Gesese
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Wakaba Omi
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Sadie B Baer
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Rizelle Mae Rose
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Jesica Reemmer
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
| | - Detlev Boison
- RS Dow Neurobiology Laboratories, Department of Translational Neuroscience, Legacy Research Institute, Portland, OR, United States
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Sabetghadam A, Wu C, Liu J, Zhang L, Reid AY. Increased epileptogenicity in a mouse model of neurofibromatosis type 1. Exp Neurol 2020; 331:113373. [PMID: 32502580 DOI: 10.1016/j.expneurol.2020.113373] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/22/2020] [Accepted: 06/01/2020] [Indexed: 11/19/2022]
Abstract
RATIONALE Neurofibromatosis type 1 (NF1) is associated with higher rates of epilepsy compared to the general population. Some NF1 patients with epilepsy do not have intracranial lesions, suggesting the genetic mutation itself may contribute to higher rates of epilepsy in these patients. We have recently demonstrated increased seizure susceptibility in the Nf1+/- mouse, but it is unknown whether this model displays altered epileptogenicity, as has been reported in patients with NF1. The aim of this study was to determine whether the Nf1+/- mouse is more susceptible to electrical kindling-induced epileptogenesis. METHODS Young male or female adult Nf1+/- or Nf1+/+ (wild-type; WT) mice were implanted with electrodes for neocortical or hippocampal kindling paradigms. Neocortical kindling was performed for 40 stimulation sessions followed by baseline EEG monitoring to detect possible SRSs. Hippocampal kindling was performed with a modified extended kindling paradigm, completed to a maximum of 80 sessions to try to induce spontaneous repetitive seizures (SRSs). Western blot assays were performed in naïve and kindled mice to compare levels of Akt and MAPK (ERK1/2), proteins downstream of the NF1 mutation. RESULTS The average initial neocortical after-discharge threshold (ADT) was significantly lower in the Nf1+/- group, which also required fewer stimulations to reach stage 5 seizure, had greater average seizure severity across all kindling sessions, had a greater number of convulsive seizures, and had a faster progression of after-discharge duration and Racine score during kindling. No WT mice exhibited SRS after neocortical kindling, versus 33% of Nf1+/- mice. The average initial hippocampal ADT was not significantly different between the WT and Nf1+/- groups, nor was there a difference in the number of stimulations required to reach the kindled state. The WT group had a significantly higher average seizure severity across all kindling sessions as compared with the Nf1+/- mice. The WT group also had faster progression of the Racine seizure score over the kindling sessions, mainly due to a faster increase in seizures severity early during the kindling process. However, SRSs were seen in 50% of Nf1+/- mice after modified extended kindling and in no WT mice. Western blots showed hippocampal kindling increased the ratio of phosphorylated/total Akt in both the WT and Nf1+/- mice, while neocortical kindling led to increased ratios of phosphorylated/total Akt and MAPK in Nf1+/- mice only. CONCLUSIONS We have demonstrated for the first time an increased rate of epileptogenesis in an animal model of NF1 with no known macroscopic/neoplastic brain lesions. This work provides evidence for the genetic mutation itself playing a role in seizures and epilepsy in patients with NF1, and supports the use of the Nf1+/- mouse model in future mechanistic studies.
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Affiliation(s)
- A Sabetghadam
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada.
| | - C Wu
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - J Liu
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - L Zhang
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
| | - A Y Reid
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
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Casillas‐Espinosa PM, Ali I, O'Brien TJ. Neurodegenerative pathways as targets for acquired epilepsy therapy development. Epilepsia Open 2020; 5:138-154. [PMID: 32524040 PMCID: PMC7278567 DOI: 10.1002/epi4.12386] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 12/16/2022] Open
Abstract
There is a growing body of clinical and experimental evidence that neurodegenerative diseases and epileptogenesis after an acquired brain insult may share common etiological mechanisms. Acquired epilepsy commonly develops as a comorbid condition in patients with neurodegenerative diseases such as Alzheimer's disease, although it is likely much under diagnosed in practice. Progressive neurodegeneration has also been described after traumatic brain injury, stroke, and other forms of brain insults. Moreover, recent evidence has shown that acquired epilepsy is often a progressive disorder that is associated with the development of drug resistance, cognitive decline, and worsening of other neuropsychiatric comorbidities. Therefore, new pharmacological therapies that target neurobiological pathways that underpin neurodegenerative diseases have potential to have both an anti-epileptogenic and disease-modifying effect on the seizures in patients with acquired epilepsy, and also mitigate the progressive neurocognitive and neuropsychiatric comorbidities. Here, we review the neurodegenerative pathways that are plausible targets for the development of novel therapies that could prevent the development or modify the progression of acquired epilepsy, and the supporting published experimental and clinical evidence.
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Affiliation(s)
- Pablo M. Casillas‐Espinosa
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Idrish Ali
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Terence J. O'Brien
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
- Department of NeurologyThe Alfred HospitalMelbourneVic.Australia
- Department of NeurologyThe Royal Melbourne HospitalParkvilleVic.Australia
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Jaworski T. Control of neuronal excitability by GSK-3beta: Epilepsy and beyond. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118745. [PMID: 32450268 DOI: 10.1016/j.bbamcr.2020.118745] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 12/22/2022]
Abstract
Glycogen synthase kinase 3beta (GSK-3β) is an enzyme with a variety of cellular functions in addition to the regulation of glycogen metabolism. In the central nervous system, different intracellular signaling pathways converge on GSK-3β through a cascade of phosphorylation events that ultimately control a broad range of neuronal functions in the development and adulthood. In mice, genetically removing or increasing GSK-3β cause distinct functional and structural neuronal phenotypes and consequently affect cognition. Precise control of GSK-3β activity is important for such processes as neuronal migration, development of neuronal morphology, synaptic plasticity, excitability, and gene expression. Altered GSK-3β activity contributes to aberrant plasticity within neuronal circuits leading to neurological, psychiatric disorders, and neurodegenerative diseases. Therapeutically targeting GSK-3β can restore the aberrant plasticity of neuronal networks at least in animal models of these diseases. Although the complete repertoire of GSK-3β neuronal substrates has not been defined, emerging evidence shows that different ion channels and their accessory proteins controlling excitability, neurotransmitter release, and synaptic transmission are regulated by GSK-3β, thereby supporting mechanisms of synaptic plasticity in cognition. Dysregulation of ion channel function by defective GSK-3β activity sustains abnormal excitability in the development of epilepsy and other GSK-3β-linked human diseases.
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Affiliation(s)
- Tomasz Jaworski
- Laboratory of Animal Models, Nencki Institute of Experimental Biology, Warsaw, Poland.
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Jin B, Aung T, Geng Y, Wang S. Epilepsy and Its Interaction With Sleep and Circadian Rhythm. Front Neurol 2020; 11:327. [PMID: 32457690 PMCID: PMC7225332 DOI: 10.3389/fneur.2020.00327] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 04/03/2020] [Indexed: 12/12/2022] Open
Abstract
Growing evidence shows the bidirectional interactions between sleep, circadian rhythm, and epilepsy. Comprehending how these interact with each other may help to advance our understanding of the pathophysiology of epilepsy and develop new treatment strategies to improve seizure control by reducing the medication side effects and the risks associated with seizures. In this review, we present the overview of different temporal patterns of interictal epileptiform discharges and epileptic seizures over a period of 24 consecutive hours. Furthermore, we discuss the underlying mechanism of the core-clock gene in periodic seizure occurrences. Finally, we outline the role of circadian patterns of seizures on seizure forecasting models and its implication for chronotherapy in epilepsy.
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Affiliation(s)
- Bo Jin
- Department of Neurology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Thandar Aung
- Barrow Neurological Institute, Epilepsy Center, Phoenix, AZ, United States
| | - Yu Geng
- Department of Neurology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Shuang Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Laser microdissection-based microproteomics of the hippocampus of a rat epilepsy model reveals regional differences in protein abundances. Sci Rep 2020; 10:4412. [PMID: 32157145 PMCID: PMC7064578 DOI: 10.1038/s41598-020-61401-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 02/18/2020] [Indexed: 01/11/2023] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is a chronic neurological disorder affecting almost 40% of adult patients with epilepsy. Hippocampal sclerosis (HS) is a common histopathological abnormality found in patients with MTLE. HS is characterised by extensive neuronal loss in different hippocampus sub-regions. In this study, we used laser microdissection-based microproteomics to determine the protein abundances in different regions and layers of the hippocampus dentate gyrus (DG) in an electric stimulation rodent model which displays classical HS damage similar to that found in patients with MTLE. Our results indicate that there are differences in the proteomic profiles of different layers (granule cell and molecular), as well as different regions, of the DG (ventral and dorsal). We have identified new signalling pathways and proteins present in specific layers and regions of the DG, such as PARK7, RACK1, and connexin 31/gap junction. We also found two major signalling pathways that are common to all layers and regions: inflammation and energy metabolism. Finally, our results highlight the utility of high-throughput microproteomics and spatial-limited isolation of tissues in the study of complex disorders to fully appreciate the large biological heterogeneity present in different cell populations within the central nervous system.
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Valmiki RR, Venkatesalu S, Chacko AG, Prabhu K, Thomas MM, Mathew V, Yoganathan S, Muthusamy K, Chacko G, Vanjare HA, Krothapalli SB. Phosphoproteomic analysis reveals Akt isoform-specific regulation of cytoskeleton proteins in human temporal lobe epilepsy with hippocampal sclerosis. Neurochem Int 2019; 134:104654. [PMID: 31884041 DOI: 10.1016/j.neuint.2019.104654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 12/03/2019] [Accepted: 12/23/2019] [Indexed: 01/04/2023]
Abstract
Akt is one of the most important downstream effectors of phosphatidylinositol 3-kinase/mTOR pathway. Hyperactivation and expression of this pathway are seen in a variety of neurological disorders including human temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Nevertheless, the expression and activation profiles of the Akt isoforms, Akt1, Akt2, and Akt3 and their functional roles in human TLE-HS have not been studied. We examined the protein expression and activation (phosphorylation) patterns of Akt and its isoforms in human hippocampal tissue from TLE and non-TLE patients. A phosphoproteomic approach followed by interactome analysis of each Akt isoform was used to understand protein-protein interactions and their role in TLE-HS pathology. Our results demonstrated activation of the Akt/mTOR pathway as well as activation of Akt downstream substrates like GSK3β, mTOR, and S6 in TLE-HS samples. Akt1 isoform levels were significantly increased in the TLE-HS samples as compared to the non-TLE samples. Most importantly, different isoforms were activated in different TLE-HS samples, Akt2 was activated in three samples, Akt2 and Akt1 were simultaneously activated in one sample and Akt3 was activated in two samples. Our phosphoproteomic screen across six TLE-HS samples identified 183 proteins phosphorylated by Akt isoforms, 29 of these proteins belong to cytoskeletal modification. Also, we were able to identify proteins of several other classes involved in glycolysis, neuronal development, protein folding and excitatory amino acid transport functions as Akt substrates. Taken together, our data offer clues to understand the role of Akt and its isoforms in underlying the pathology of TLE-HS and further, modulation of Akt/mTOR pathway using Akt isoforms specific inhibitors may offer a new therapeutic window for treatment of human TLE-HS.
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Affiliation(s)
- Rajesh Ramanna Valmiki
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India.
| | - Subhashini Venkatesalu
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Ari George Chacko
- Neurosurgery, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Krishna Prabhu
- Neurosurgery, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Maya Mary Thomas
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Vivek Mathew
- Neurology, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Sangeetha Yoganathan
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Karthik Muthusamy
- Department of Pediatric Neurology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | - Geeta Chacko
- Neuropathology, Department of General Pathology, Christian Medical College, Vellore, 632004, Tamilnadu, India
| | | | - Srinivasa Babu Krothapalli
- Neurophysiology Laboratory, Department of Neurological Sciences, Christian Medical College, Vellore, 632004, Tamilnadu, India
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Gericke B, Brandt C, Theilmann W, Welzel L, Schidlitzki A, Twele F, Kaczmarek E, Anjum M, Hillmann P, Löscher W. Selective inhibition of mTORC1/2 or PI3K/mTORC1/2 signaling does not prevent or modify epilepsy in the intrahippocampal kainate mouse model. Neuropharmacology 2019; 162:107817. [PMID: 31654704 DOI: 10.1016/j.neuropharm.2019.107817] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/26/2019] [Accepted: 10/18/2019] [Indexed: 12/23/2022]
Abstract
Dysregulation of the PI3K/Akt/mTOR pathway has been implicated in several brain disorders, including epilepsy. Rapamycin and similar compounds inhibit mTOR. complex 1 and have been reported to decrease seizures, delay seizure development, or prevent epileptogenesis in different animal models of genetic or acquired epilepsies. However, data for acquired epilepsy are inconsistent, which, at least in part, may be due to the poor brain penetration and long brain persistence of rapamycin and the fact that it blocks only one of the two cellular mTOR complexes. Here we examined the antiepileptogenic or disease-modifying effects of two novel, brain-permeable and well tolerated 1,3,5-triazine derivatives, the ATP-competitive mTORC1/2 inhibitor PQR620 and the dual pan-PI3K/mTORC1/2 inhibitor PQR530 in the intrahippocampal kainate mouse model, in which spontaneous seizures develop after status epilepticus (SE). Following kainate injection, the two compounds were administered over 2 weeks at doses previously been shown to block mTORC1/2 or PI3K/mTORC1/2 in the mouse brain. When spontaneous seizures were recorded by continuous (24/7) video-EEG recording starting 6 weeks after termination of treatment, no effects on incidence or frequency of seizures were observed. Drug treatment suppressed the epilepsy-induced activation of the PI3K/Akt/mTOR pathway in the hippocampus, but granule cell dispersion in the dentate gyrus was not prevented. When epilepsy-associated behavioral alterations were determined 12-14 weeks after kainate, mice pretreated with PQR620 or PQR530 exhibited reduced anxiety-related behavior in the light-dark box, indicating a disease-modifying effect. Overall, the data indicate that mTORC1/C2 or PI3K/mTORC1/C2 inhibition may not be an antiepileptogenic strategy for SE-induced epilepsy.
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Affiliation(s)
- Birthe Gericke
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Claudia Brandt
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Wiebke Theilmann
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Lisa Welzel
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Alina Schidlitzki
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Friederike Twele
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Edith Kaczmarek
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Muneeb Anjum
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | | | - Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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Cortical Seizures in FoxG1+/- Mice are Accompanied by Akt/S6 Overactivation, Excitation/Inhibition Imbalance and Impaired Synaptic Transmission. Int J Mol Sci 2019; 20:ijms20174127. [PMID: 31450553 PMCID: PMC6747530 DOI: 10.3390/ijms20174127] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 08/22/2019] [Indexed: 12/14/2022] Open
Abstract
The correct morphofunctional shaping of the cerebral cortex requires a continuous interaction between intrinsic (genes/molecules expressed within the tissue) and extrinsic (e.g., neural activity) factors at all developmental stages. Forkhead Box G1 (FOXG1) is an evolutionarily conserved transcription factor, essential for the cerebral cortex patterning and layering. FOXG1-related disorders, including the congenital form of Rett syndrome, can be caused by deletions, intragenic mutations or duplications. These genetic alterations are associated with a complex phenotypic spectrum, spanning from intellectual disability, microcephaly, to autistic features, and epilepsy. We investigated the functional correlates of dysregulated gene expression by performing electrophysiological assays on FoxG1+/- mice. Local Field Potential (LFP) recordings on freely moving animals detected cortical hyperexcitability. On the other hand, patch-clamp recordings showed a downregulation of spontaneous glutamatergic transmission. These findings were accompanied by overactivation of Akt/S6 signaling. Furthermore, the expression of vesicular glutamate transporter 2 (vGluT2) was increased, whereas the level of the potassium/chloride cotransporter KCC2 was reduced, thus indicating a higher excitation/inhibition ratio. Our findings provide evidence that altered expression of a key gene for cortical development can result in specific alterations in neural circuit function at the macro- and micro-scale, along with dysregulated intracellular signaling and expression of proteins controlling circuit excitability.
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Koene LMC, van Grondelle SE, Proietti Onori M, Wallaard I, Kooijman NHRM, van Oort A, Schreiber J, Elgersma Y. Effects of antiepileptic drugs in a new TSC/mTOR-dependent epilepsy mouse model. Ann Clin Transl Neurol 2019; 6:1273-1291. [PMID: 31353861 PMCID: PMC6649373 DOI: 10.1002/acn3.50829] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 06/05/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE An epilepsy mouse model for Tuberous Sclerosis Complex (TSC) was developed and validated to investigate the mechanisms underlying epileptogenesis. Furthermore, the possible antiepileptogenic properties of commonly used antiepileptic drugs (AEDs) and new compounds were assessed. METHODS Tsc1 deletion was induced in CAMK2A-expressing neurons of adult mice. The antiepileptogenic properties of commonly used AEDs and inhibitors of the mTOR pathways were assessed by EEG recordings and by molecular read outs. RESULTS Mice developed epilepsy in a narrow time window (10 ± 2 days) upon Tsc1 gene deletion. Seizure frequency but not duration increased over time. Seizures were lethal within 18 days, were unpredictable, and did not correlate to seizure onset, length or frequency, reminiscent of sudden unexpected death in epilepsy (SUDEP). Tsc1 gene deletion resulted in a strong activation of the mTORC1 pathway, and both epileptogenesis and lethality could be entirely prevented by RHEB1 gene deletion or rapamycin treatment. However, other inhibitors of the mTOR pathway such as AZD8055 and PF4708671 were ineffective. Except for ketogenic diet, none of commonly used AEDs showed an effect on mTORC1 activity. Vigabatrin and ketogenic diet treatment were able to significantly delay seizure onset. In contrast, survival was shortened by lamotrigine. INTERPRETATION This novel Tsc1 mouse model is highly suitable to assess the efficacy of antiepileptic and -epileptogenic drugs to treat mTORC1-dependent epilepsy. Additionally, it allows us to study the mechanisms underlying mTORC1-mediated epileptogenesis and SUDEP. We found that early treatment with vigabatrin was not able to prevent epilepsy, but significantly delayed seizure onset.
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Affiliation(s)
- Linda M. C. Koene
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Saskia E. van Grondelle
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Martina Proietti Onori
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Ilse Wallaard
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Nathalie H. R. M. Kooijman
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Annabel van Oort
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Jadwiga Schreiber
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
| | - Ype Elgersma
- Department of Neuroscience and ENCORE Expertise Center for Neurodevelopmental DisordersErasmus MC University Medical CenterRotterdam3015 CNThe Netherlands
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GSK-3 β at the Intersection of Neuronal Plasticity and Neurodegeneration. Neural Plast 2019; 2019:4209475. [PMID: 31191636 PMCID: PMC6525914 DOI: 10.1155/2019/4209475] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/08/2019] [Indexed: 01/08/2023] Open
Abstract
In neurons, Glycogen Synthase Kinase-3β (GSK-3β) has been shown to regulate various critical processes underlying structural and functional synaptic plasticity. Mouse models with neuron-selective expression or deletion of GSK-3β present behavioral and cognitive abnormalities, positioning this protein kinase as a key signaling molecule in normal brain functioning. Furthermore, mouse models with defective GSK-3β activity display distinct structural and behavioral abnormalities, which model some aspects of different neurological and neuropsychiatric disorders. Equalizing GSK-3β activity in these mouse models by genetic or pharmacological interventions is able to rescue some of these abnormalities. Thus, GSK-3β is a relevant therapeutic target for the treatment of many brain disorders. Here, we provide an overview of how GSK-3β is regulated in physiological synaptic plasticity and how aberrant GSK-3β activity contributes to the development of dysfunctional synaptic plasticity in neuropsychiatric and neurodegenerative disorders.
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Abstract
Remodeled Cortical Inhibition Prevents Motor Seizures in Generalized Epilepsy Jiang X, Lupien-Meilleur A, Tazerart S, Lachance M, Samarova E, Araya R, Lacaille JC, Rossignol E. Ann Neurol. 2018 Sep;84(3):436-451. OBJECTIVE Deletions of CACNA1A, encoding the α1 subunit of CaV 2.1 channels, cause epilepsy with ataxia in humans. Whereas the deletion of Cacna1a in γ-aminobutyric acidergic (GABAergic) interneurons (INs) derived from the medial ganglionic eminence (MGE) impairs cortical inhibition and causes generalized seizures in Nkx2.1Cre;Cacna1ac/c mice, the targeted deletion of Cacna1a in somatostatin-expressing INs (SOM-INs), a subset of MGE-derived INs, does not result in seizures, indicating a crucial role of parvalbumin-expressing (PV) INs. Here, we identify the cellular and network consequences of Cacna1a deletion specifically in PV-INs. METHODS We generated PVCre;Cacna1ac/c mutant mice carrying a conditional Cacna1a deletion in PV neurons and evaluated the cortical cellular and network outcomes of this mutation by combining immunohistochemical assays, in vitro electrophysiology, 2-photon imaging, and in vivo video-electroencephalographic recordings. RESULTS PVCre;Cacna1ac/c mice display reduced cortical perisomatic inhibition and frequent absences, but only rare motor seizures. Compared to Nkx2.1Cre;Cacna1ac/c mice, PVCre;Cacna1ac/c mice have a net increase in cortical inhibition, with a gain of dendritic inhibition through sprouting of SOM-IN axons, largely preventing motor seizures. This beneficial compensatory remodeling of cortical GABAergic innervation is mechanistic target of rapamycin complex 1 (mTORC1)-dependent, and its inhibition with rapamycin leads to a striking increase in motor seizures. Furthermore, we show that a direct chemogenic activation of cortical SOM-INs prevents motor seizures in a model of kainate-induced seizures. INTERPRETATION Our findings provide novel evidence suggesting that the remodeling of cortical inhibition, with an mTOR-dependent gain of dendritic inhibition, determines the seizure phenotype in generalized epilepsy and that mTOR inhibition can be detrimental in epilepsies not primarily due to mTOR hyperactivation.
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