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Wu S, Zhang YF, Gui Y, Jiang T, Zhou CM, Li JY, Suo JL, Li YN, Jin RL, Li SL, Cui JY, Tan BH, Li YC. A detection method for neuronal death indicates abnormalities in intracellular membranous components in neuronal cells that underwent delayed death. Prog Neurobiol 2023; 226:102461. [PMID: 37179048 DOI: 10.1016/j.pneurobio.2023.102461] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/20/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023]
Abstract
Acute neuronal degeneration is always preceded under the light and electron microscopes by a stage called microvacuolation, which is characterized by a finely vacuolar alteration in the cytoplasm of the neurons destined to death. In this study, we reported a method for detecting neuronal death using two membrane-bound dyes, rhodamine R6 and DiOC6(3), which may be associated with the so-called microvacuolation. This new method produced a spatiotemporally similar staining pattern to Fluoro-Jade B in kainic acid-damaged brains in mice. Further experiments showed that increased staining of rhodamine R6 and DiOC6(3) was observed only in degenerated neurons, but not in glia, erythrocytes, or meninges. Different from Fluoro-Jade-related dyes, rhodamine R6 and DiOC6(3) staining is highly sensitive to solvent extraction and detergent exposure. Staining with Nile red for phospholipids and filipin III for non-esterified cholesterol supports that the increased staining of rhodamine R6 and DiOC6(3) might be associated with increased levels of phospholipids and free cholesterol in the perinuclear cytoplasm of damaged neurons. In addition to kainic acid-injected neuronal death, rhodamine R6 and DiOC6(3) were similarly useful for detecting neuronal death in ischemic models either in vivo or in vitro. As far as we know, the staining with rhodamine R6 or DiOC6(3) is one of a few histochemical methods for detecting neuronal death whose target molecules have been well defined and therefore may be useful for explaining experimental results as well as exploring the mechanisms of neuronal death. (250 words).
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Affiliation(s)
- Shuang Wu
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Yan-Feng Zhang
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Yue Gui
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Tian Jiang
- Department of Emergency and Critical Care Medicine, The Second Hospital of Jilin University, Jilin Province 130041, PR China
| | - Cheng-Mei Zhou
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Jing-Yi Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Jia-Le Suo
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Yong-Nan Li
- Department of Neurology, Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province 150001, PR China
| | - Rui-Lin Jin
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Shu-Lei Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Jia-Yue Cui
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Bai-Hong Tan
- Laboratory Teaching Center of Basic Medicine, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China
| | - Yan-Chao Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Jilin Province 130021, PR China.
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McLeod F, Dimtsi A, Marshall AC, Lewis-Smith D, Thomas R, Clowry GJ, Trevelyan AJ. Altered synaptic connectivity in an in vitro human model of STXBP1 encephalopathy. Brain 2023; 146:850-857. [PMID: 36315647 PMCID: PMC9976961 DOI: 10.1093/brain/awac396] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 08/05/2022] [Accepted: 10/01/2022] [Indexed: 01/14/2023] Open
Abstract
Early infantile developmental and epileptic encephalopathies are devastating conditions, generally of genetic origin, but the pathological mechanisms often remain obscure. A major obstacle in this field of research is the difficulty of studying cortical brain development in humans, at the relevant time period in utero. To address this, we established an in vitro assay to study the impact of gene variants on the developing human brain by using living organotypic cultures of the human subplate and neighbouring cortical regions, prepared from ethically sourced, 14-17 post-conception week brain tissue (www.hdbr.org). We were able to maintain cultures for several months, during which time the gross anatomical structures of the cortical plate, subplate and marginal zone persisted, while neurons continued to develop morphologically and form new synaptic networks. This preparation thus permits the study of genetic manipulations and their downstream effects on an intact developing human cortical network. We focused on STXBP1 haploinsufficiency, which is among the most common genetic causes of developmental and epileptic encephalopathy. This was induced using shRNA interference, leading to impaired synaptic function and a reduced density of glutamatergic synapses. We thereby provide a critical proof-of-principle for how to study the impact of any gene of interest on the development of the human cortex.
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Affiliation(s)
- Faye McLeod
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Anna Dimtsi
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Amy C Marshall
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - David Lewis-Smith
- Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne NE2 4HH, UK
- Department of Clinical Neurosciences, Royal Victoria Infirmary, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Rhys Thomas
- Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne NE2 4HH, UK
- Department of Clinical Neurosciences, Royal Victoria Infirmary, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 4LP, UK
| | - Gavin J Clowry
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Andrew J Trevelyan
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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3
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SAPAP3 regulates epileptic seizures involving GluN2A in post-synaptic densities. Cell Death Dis 2022; 13:437. [PMID: 35513389 PMCID: PMC9072407 DOI: 10.1038/s41419-022-04876-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/15/2022] [Accepted: 04/21/2022] [Indexed: 12/14/2022]
Abstract
Aberrantly synchronized neuronal discharges in the brain lead to epilepsy, a devastating neurological disease whose pathogenesis and mechanism are unclear. SAPAP3, a cytoskeletal protein expressed at high levels in the postsynaptic density (PSD) of excitatory synapses, has been well studied in the striatum, but the role of SAPAP3 in epilepsy remains elusive. In this study, we sought to investigate the molecular, cellular, electrophysiological and behavioral consequences of SAPAP3 perturbations in the mouse hippocampus. We identified a significant increase in the SAPAP3 levels in patients with temporal lobe epilepsy (TLE) and in mouse models of epilepsy. In addition, behavioral studies showed that the downregulation of SAPAP3 by shRNA decreased the seizure severity and that the overexpression of SAPAP3 by recombinant SAPAP3 yielded the opposite effect. Moreover, SAPAP3 affected action potentials (APs), miniature excitatory postsynaptic currents (mEPSCs) and N-methyl-D-aspartate receptor (NMDAR)-mediated currents in the CA1 region, which indicated that SAPAP3 plays an important role in excitatory synaptic transmission. Additionally, the levels of the GluN2A protein, which is involved in synaptic function, were perturbed in the hippocampal PSD, and this perturbation was accompanied by ultrastructural morphological changes. These results revealed a previously unknown function of SAPAP3 in epileptogenesis and showed that SAPAP3 may represent a novel target for the treatment of epilepsy.
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Brivaracetam Modulates Short-Term Synaptic Activity and Low-Frequency Spontaneous Brain Activity by Delaying Synaptic Vesicle Recycling in Two Distinct Rodent Models of Epileptic Seizures. J Mol Neurosci 2022; 72:1058-1074. [PMID: 35278193 DOI: 10.1007/s12031-022-01983-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/03/2022] [Indexed: 10/18/2022]
Abstract
Brivaracetam (BRV) is an anti-seizure drug for the treatment of focal and generalized epileptic seizures shown to augment short-term synaptic fatigue by slowing down synaptic vesicle recycling rates in control animals. In this study, we sought to investigate whether altered short-term synaptic activities could be a pathological hallmark during the interictal periods of epileptic seizures in two well-established rodent models, as well as to reveal BRV's therapeutic roles in altered short-term synaptic activities and low-frequency band spontaneous brain hyperactivity in these models. In our study, the electrophysiological field excitatory post-synaptic potential (fEPSP) recordings were performed in rat hippocampal brain slices from the CA1 region by stimulation of the Schaffer collateral/commissural pathway with or without BRV (30 μM for 3 h) in control or epileptic seizure (induced by pilocarpine (PILO) or high potassium (h-K+)) models. Short-term synaptic activities were induced by 5, 10, 20, and 40-Hz stimulation sequences. The effects of BRV on pre-synaptic vesicle mobilization were visually assessed by staining the synaptic vesicles with FM1-43 dye followed by imaging with a two-photon microscope. In the fEPSP measurements, short-term synaptic fatigue was found in the control group, while short-term synaptic potentiation (STP) was detected in both PILO and h-K+ models. STP was decreased after the slices were treated with BRV (30 μM) for 3 h. BRV also exhibited its therapeutic benefits by decreasing abnormal peak power (frequency range of 8-13 Hz, 31% of variation for PILO model, 25% of variation for h-K+ model) and trough power (frequency range of 1-4 Hz, 66% of variation for PILO model, 49% of variation for h-K+ model), and FM1-43 stained synaptic vesicle mobility (64% of the variation for PILO model, 45% of the variation for h-K+ model) in these epileptic seizure models. To the best of our knowledge, this was the first report that BRV decreased the STP and abnormal low-frequency brain activities during the interictal phase of epileptic seizures by slowing down the mobilization of synaptic vesicles in two rodent models. These mechanistic findings would greatly advance our understanding of BRV's pharmacological role in pathomechanisms of epileptic seizures and its treatment strategy optimization to avoid or minimize BRV-induced possible adverse side reactions.
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Zhou J, Liang W, Wang J, Chen J, Liu D, Wang X, Wu Y, Zhang Q, Shen D. An epileptic encephalopathy associated GABRG2 missense mutation leads to pre- and postsynaptic defects in zebrafish. Hum Mol Genet 2021; 31:3216-3230. [PMID: 34957497 DOI: 10.1093/hmg/ddab338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Mutations in the γ-aminobutyric acid type A (GABAA) receptor γ2 subunit gene, GABRG2, have been associated with a variety of epilepsy syndromes. A de novo mutation (c.T1027C, p.F343L) in GABRG2 was identified in a patient with early onset epileptic encephalopathy. Zebrafish overexpressing mutant human GABRG2 (F343L) subunits displayed spontaneous seizure activity and convulsive behaviors. In this study, we demonstrated that Tg (hGABRG2F343L) zebrafish displayed hyperactivity during light phase with normal circadian rhythm, as well as increased drug-induced locomotor activity. Real-time quantitative PCR, whole mount in situ hybridization and western blotting showed that Tg(hGABRG2F343L) zebrafish had altered expression of GABAA receptor subunits. Furthermore, investigation of synaptic protein expression and synapse ultrastructure uncovered a robust synaptic phenotype that is causally linked to GABRG2(F343L) mutation. Strikingly, Tg(hGABRG2F343L) zebrafish not only had postsynaptic defects, but also displayed an unanticipated deficit at the presynaptic level. Overall, our Tg(hGABRG2F343L) overexpression zebrafish model has expanded the GABAergic paradigm in epileptic encephalopathy from channelopathy to synaptopathy.
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Affiliation(s)
- Jing Zhou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Wenpeng Liang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jie Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Juan Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Dong Liu
- School of Life Science, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xin Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Youjia Wu
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Dingding Shen
- Department of Neurology & Collaborative Innovation Center for Brain Science, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
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Upaganlawar AB, Wankhede NL, Kale MB, Umare MD, Sehgal A, Singh S, Bhatia S, Al-Harrasi A, Najda A, Nurzyńska-Wierdak R, Bungau S, Behl T. Interweaving epilepsy and neurodegeneration: Vitamin E as a treatment approach. Biomed Pharmacother 2021; 143:112146. [PMID: 34507113 DOI: 10.1016/j.biopha.2021.112146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is the most common neurological disorder, affecting nearly 50 million people worldwide. The condition can be manifested either due to genetic predisposition or acquired from acute insult which leads to alteration of cellular and molecular mechanisms. Evaluating the latest and the current knowledge in regard to the mechanisms underlying molecular and cellular alteration, hyperexcitability is a consequence of an imbalanced state wherein enhance excitatory glutamatergic and reduced inhibitory GABAergic signaling is considered to be accountable for seizures associated damage. However, neurodegeneration contributing to epileptogenesis has become increasingly appreciated. The components at the helm of neurodegenerative alterations during epileptogenesis include GABAergic neuronal and receptor changes, neuroinflammation, alteration in axonal transport, oxidative stress, excitotoxicity, and other cellular as well as functional changes. Targeting neurodegeneration with vitamin E as an antioxidant, anti-inflammatory and neuroprotective may prove to be one of the therapeutic approaches useful in managing epilepsy. In this review, we discuss and converse about the seizure-induced episodes as a link for the development of neurodegenerative and pathological consequences of epilepsy. We also put forth a summary of the potential intervention with vitamin E therapy in the management of epilepsy.
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Affiliation(s)
- Aman B Upaganlawar
- SNJB's Shriman Sureshdada Jain College of Pharmacy, Neminagar, Chandwad, Nashik, Maharashtra, India
| | - Nitu L Wankhede
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Mayur B Kale
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Mohit D Umare
- Smt. Kishoritai Bhoyar College of Pharmacy, Kamptee, Nagpur, Maharashtra, India
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Saurabh Bhatia
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Ahmed Al-Harrasi
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Agnieszka Najda
- Department of Vegetable Crops and Medicinal Plants, University of Life Sciences, Lublin, Poland.
| | | | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Romania
| | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab, India.
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Zaitsev АV, Amakhin DV, Dyomina AV, Zakharova MV, Ergina JL, Postnikova TY, Diespirov GP, Magazanik LG. Synaptic Dysfunction in Epilepsy. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s002209302103008x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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8
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Classifying epilepsy pragmatically: Past, present, and future. J Neurol Sci 2021; 427:117515. [PMID: 34174531 PMCID: PMC7613525 DOI: 10.1016/j.jns.2021.117515] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 01/31/2023]
Abstract
The classification of epilepsy is essential for people with epilepsy and their families, healthcare providers, physicians and researchers. The International League Against Epilepsy proposed updated seizure and epilepsy classifications in 2017, while another four-dimensional epilepsy classification was updated in 2019. An Integrated Epilepsy Classification system was proposed in 2020. Existing classifications, however, lack consideration of important pragmatic factors relevant to the day-to-day life of people with epilepsy and stakeholders. Despite promising developments, consideration of comorbidities in brain development, genetic causes, and environmental triggers of epilepsy remains largely user-dependent in existing classifications. Demographics of epilepsy have changed over time, while existing classification schemes exhibit caveats. A pragmatic classification scheme should incorporate these factors to provide a nuanced classification. Validation across disparate contexts will ensure widespread applicability and ease of use. A team-based approach may simplify communication between healthcare personnel, while an individual-centred perspective may empower people with epilepsy. Together, incorporating these elements into a modern but pragmatic classification scheme may ensure optimal care for people with epilepsy by emphasising cohesiveness among its myriad users. Technological advancements such as 7T MRI, next-generation sequencing, and artificial intelligence may affect future classification efforts.
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Lesage S, Mangone G, Tesson C, Bertrand H, Benmahdjoub M, Kesraoui S, Arezki M, Singleton A, Corvol JC, Brice A. Clinical Variability of SYNJ1-Associated Early-Onset Parkinsonism. Front Neurol 2021; 12:648457. [PMID: 33841314 PMCID: PMC8027075 DOI: 10.3389/fneur.2021.648457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/25/2021] [Indexed: 11/29/2022] Open
Abstract
Autosomal recessive early-onset parkinsonism is clinically and genetically heterogeneous. Mutations of three genes, PRKN, PINK1, and DJ-1 cause pure phenotypes usually characterized by levodopa-responsive Parkinson's disease. By contrast, mutations of other genes, including ATP13A2, PLA2G6, FBXO7, DNAJC6, SYNJ1, VPS13C, and PTRHD1, cause rarer, more severe diseases with a poor response to levodopa, generally with additional atypical features. We performed data mining on a gene panel or whole-exome sequencing in 460 index cases with early-onset (≤ 40 years) Parkinson's disease, including 57 with autosomal recessive disease and 403 isolated cases. We identified two isolated cases carrying biallelic mutations of SYNJ1 (double-heterozygous p.D791fs/p.Y232H and homozygous p. Y832C mutations) and two siblings with the recurrent homozygous p.R258Q mutation. All four variants were absent or rare in the Genome Aggregation Database, were predicted to be deleterious on in silico analysis and were found to be highly conserved between species. The patient with both the previously unknown p.D791fs and p.Y232H mutations presented with dystonia-parkinsonism accompanied by a frontal syndrome and oculomotor disturbances at the age of 39. In addition, two siblings from an Algerian consanguineous family carried the homozygous p.R258Q mutation and presented generalized tonic-clonic seizures during childhood, with severe intellectual disability, followed by progressive parkinsonism during their teens. By contrast, the isolated patient with the homozygous p. Y832C mutation, diagnosed at the age of 20, had typical parkinsonism, with no atypical symptoms and slow disease progression. Our findings expand the mutational spectrum and phenotypic profile of SYNJ1-related parkinsonism.
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Affiliation(s)
- Suzanne Lesage
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
| | - Graziella Mangone
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
| | - Christelle Tesson
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
| | - Hélène Bertrand
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
| | | | | | | | - Andrew Singleton
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, United States
| | - Jean-Christophe Corvol
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
| | - Alexis Brice
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, INSERM, CNRS, Assistance Publique Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, CIC Neurosciences, Paris, France
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Owen B, Bichler E, Benveniste M. Excitatory synaptic transmission in hippocampal area CA1 is enhanced then reduced as chronic epilepsy progresses. Neurobiol Dis 2021; 154:105343. [PMID: 33753293 DOI: 10.1016/j.nbd.2021.105343] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/27/2022] Open
Abstract
This study examines changes in synaptic transmission with progression of the chronic epileptic state. Male Sprague-Dawley rats (P40-45) were injected with either saline or pilocarpine. In rats injected with pilocarpine, status epilepticus ensued. Hippocampal slices were cut 20-60 days or 80-110 days post-treatment. Evoked and miniature EPSCs (mEPSCs) were recorded from CA1 pyramidal neurons using whole-cell voltage-clamp. Fiber volleys were also recorded from stratum radiatum. Evoked EPSCs from the pilocarpine-treated cohort showed enhanced amplitudes 20-60 days post-treatment compared to the saline-treated cohort, whereas mEPSCs recorded from the same age group showed no change in event frequency and a slight but significant decrease in mEPSC amplitude distribution. In contrast, comparing evoked EPSCs and mEPSCs recorded 80-110 days after treatment indicated reduced amplitudes from pilocarpine-treated animals compared to controls. mEPSC inter-event interval decreased. This could be explained by a partial depletion of the ready releasable pool of neurotransmitter vesicles in Schaffer collateral presynaptic terminals of the pilocarpine-treated rats. In both saline- and pilocarpine-treated cohorts, concomitant decreases in mEPSC amplitudes as time after treatment progressed suggest that age-related changes in CA1 circuitry may be partially responsible for changes in synaptic transmission that may influence the chronic epileptic state.
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Affiliation(s)
- Benjamin Owen
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Edyta Bichler
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Morris Benveniste
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA.
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11
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Bentea E, Villers A, Moore C, Funk AJ, O’Donovan SM, Verbruggen L, Lara O, Janssen P, De Pauw L, Declerck NB, DePasquale EAK, Churchill MJ, Sato H, Hermans E, Arckens L, Meshul CK, Ris L, McCullumsmith RE, Massie A. Corticostriatal dysfunction and social interaction deficits in mice lacking the cystine/glutamate antiporter. Mol Psychiatry 2021; 26:4754-4769. [PMID: 32366950 PMCID: PMC7609546 DOI: 10.1038/s41380-020-0751-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 12/11/2022]
Abstract
The astrocytic cystine/glutamate antiporter system xc- represents an important source of extracellular glutamate in the central nervous system, with potential impact on excitatory neurotransmission. Yet, its function and importance in brain physiology remain incompletely understood. Employing slice electrophysiology and mice with a genetic deletion of the specific subunit of system xc-, xCT (xCT-/- mice), we uncovered decreased neurotransmission at corticostriatal synapses. This effect was partly mitigated by replenishing extracellular glutamate levels, indicating a defect linked with decreased extracellular glutamate availability. We observed no changes in the morphology of striatal medium spiny neurons, the density of dendritic spines, or the density or ultrastructure of corticostriatal synapses, indicating that the observed functional defects are not due to morphological or structural abnormalities. By combining electron microscopy with glutamate immunogold labeling, we identified decreased intracellular glutamate density in presynaptic terminals, presynaptic mitochondria, and in dendritic spines of xCT-/- mice. A proteomic and kinomic screen of the striatum of xCT-/- mice revealed decreased expression of presynaptic proteins and abnormal kinase network signaling, that may contribute to the observed changes in postsynaptic responses. Finally, these corticostriatal deregulations resulted in a behavioral phenotype suggestive of autism spectrum disorder in the xCT-/- mice; in tests sensitive to corticostriatal functioning we recorded increased repetitive digging behavior and decreased sociability. To conclude, our findings show that system xc- plays a previously unrecognized role in regulating corticostriatal neurotransmission and influences social preference and repetitive behavior.
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Affiliation(s)
- Eduard Bentea
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Agnès Villers
- grid.8364.90000 0001 2184 581XDepartment of Neurosciences, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Cynthia Moore
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA
| | - Adam J. Funk
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Sinead M. O’Donovan
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Lise Verbruggen
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Olaya Lara
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Pauline Janssen
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Laura De Pauw
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Noemi B. Declerck
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Erica A. K. DePasquale
- grid.239573.90000 0000 9025 8099Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.24827.3b0000 0001 2179 9593Department of Biomedical Informatics, University of Cincinnati, Cincinnati, OH USA
| | - Madeline J. Churchill
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA
| | - Hideyo Sato
- grid.260975.f0000 0001 0671 5144Department of Medical Technology, Faculty of Medicine, Laboratory of Biochemistry and Molecular Biology, Niigata University, Niigata, Japan
| | - Emmanuel Hermans
- grid.7942.80000 0001 2294 713XInstitute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Lutgarde Arckens
- grid.5596.f0000 0001 0668 7884Laboratory of Neuroplasticity and Neuroproteomics, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven, Belgium
| | - Charles K. Meshul
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR USA
| | - Laurence Ris
- grid.8364.90000 0001 2184 581XDepartment of Neurosciences, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Robert E. McCullumsmith
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Ann Massie
- Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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12
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Zheng YQ, Jin MF, Suo GH, Wu YJ, Sun YX, Ni H. Proteomics for Studying the Effects of Ketogenic Diet Against Lithium Chloride/Pilocarpine Induced Epilepsy in Rats. Front Neurosci 2020; 14:562853. [PMID: 33132826 PMCID: PMC7550537 DOI: 10.3389/fnins.2020.562853] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
The ketogenic diet (KD) demonstrates antiepileptogenic and neuroprotective efficacy, but the precise mechanisms are unclear. Here we explored the mechanism through systematic proteomics analysis of the lithium chloride-pilocarpine rat model. Sprague-Dawley rats (postnatal day 21, P21) were randomly divided into control (Ctr), seizure (SE), and KD treatment after seizure (SE + KD) groups. Tandem mass tag (TMT) labeling and liquid chromatography-tandem mass spectroscopy (LC-MS/MS) were utilized to assess changes in protein abundance in the hippocampus. A total of 5,564 proteins were identified, of which 110 showed a significant change in abundance between the SE and Ctr groups (18 upregulated and 92 downregulated), 278 between SE + KD and SE groups (218 upregulated and 60 downregulated), and 180 between Ctr and SE + KD groups (121 upregulated and 59 downregulated) (all p < 0.05). Seventy-nine proteins showing a significant change in abundance between SE and Ctr groups were reciprocally regulated in the SD + KD group compared to the SE group (i.e., the seizure-induced change was reversed by KD). Of these, five (dystrobrevin, centromere protein V, oxysterol-binding protein, tetraspanin-2, and progesterone receptor membrane component 2) were verified by parallel reaction monitoring. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that proteins of the synaptic vesicle cycle pathway were enriched both among proteins differing in abundance between SE and Ctr groups as well as between SE + KD and SE groups. This comprehensive proteomics analyze of KD-treated epilepsy by quantitative proteomics revealed novel molecular mechanisms of KD antiepileptogenic efficacy and potential treatment targets.
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Affiliation(s)
- Yu-Qin Zheng
- Division of Brain Science, Institute of Pediatric Research, Children's Hospital of Soochow University, Suzhou, China.,Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Mei-Fang Jin
- Division of Brain Science, Institute of Pediatric Research, Children's Hospital of Soochow University, Suzhou, China
| | - Gui-Hai Suo
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - You-Jia Wu
- Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, China
| | - Yu-Xiao Sun
- Division of Brain Science, Institute of Pediatric Research, Children's Hospital of Soochow University, Suzhou, China
| | - Hong Ni
- Division of Brain Science, Institute of Pediatric Research, Children's Hospital of Soochow University, Suzhou, China
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13
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Finnema SJ, Toyonaga T, Detyniecki K, Chen MK, Dias M, Wang Q, Lin SF, Naganawa M, Gallezot JD, Lu Y, Nabulsi NB, Huang Y, Spencer DD, Carson RE. Reduced synaptic vesicle protein 2A binding in temporal lobe epilepsy: A [ 11 C]UCB-J positron emission tomography study. Epilepsia 2020; 61:2183-2193. [PMID: 32944949 DOI: 10.1111/epi.16653] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE In this positron emission tomography (PET) study with [11 C]UCB-J, we evaluated synaptic vesicle glycoprotein 2A (SV2A) binding, which is decreased in resected brain tissues from epilepsy patients, in subjects with temporal lobe epilepsy (TLE) and compared the regional binding pattern to [18 F]fluorodeoxyglucose (FDG) uptake. METHODS Twelve TLE subjects and 12 control subjects were examined. Regional [11 C]UCB-J binding potential (BPND ) values were estimated using the centrum semiovale as a reference region. [18 F]FDG uptake in TLE subjects was quantified using mean radioactivity values. Asymmetry in outcome measures was assessed by comparison of ipsilateral and contralateral regions. Partial volume correction (PVC) with the iterative Yang algorithm was applied based on the FreeSurfer segmentation. RESULTS In 11 TLE subjects with medial temporal lobe sclerosis (MTS), the hippocampal volumetric asymmetry was 25 ± 11%. After PVC, [11 C]UCB-J BPND asymmetry indices were 37 ± 19% in the hippocampus, with very limited asymmetry in other brain regions. Reductions in [11 C]UCB-J BPND values were restricted to the sclerotic hippocampus when compared to control subjects. The corresponding asymmetry in hippocampal [18 F]FDG uptake was 22 ± 7% and correlated with that of [11 C]UCB-J BPND across subjects (R2 = .38). Hippocampal asymmetries in [11 C]UCB-J binding were 1.7-fold larger than those of [18 F]FDG uptake. SIGNIFICANCE [11 C]UCB-J binding is reduced in the seizure onset zone of TLE subjects with MTS. PET imaging of SV2A may be a promising biomarker approach in the presurgical selection and evaluation of TLE patients and may improve the sensitivity of molecular imaging for seizure focus detection.
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Affiliation(s)
- Sjoerd J Finnema
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Kamil Detyniecki
- Department of Neurology, Yale University, New Haven, Connecticut, USA
| | - Ming-Kai Chen
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Mark Dias
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Qianyu Wang
- Department of Neurology, Yale University, New Haven, Connecticut, USA
| | - Shu-Fei Lin
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Nabeel B Nabulsi
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA
| | - Dennis D Spencer
- Department of Neurosurgery, Yale University, New Haven, Connecticut, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, PET Center, Yale University, New Haven, Connecticut, USA.,Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
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Levetiracetam Reduced the Basal Excitability of the Dentate Gyrus without Restoring Impaired Synaptic Plasticity in Rats with Temporal Lobe Epilepsy. Brain Sci 2020; 10:brainsci10090634. [PMID: 32933015 PMCID: PMC7565946 DOI: 10.3390/brainsci10090634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/13/2022] Open
Abstract
Temporal lobe epilepsy (TLE), the most common type of focal epilepsy, affects learning and memory; these effects are thought to emerge from changes in synaptic plasticity. Levetiracetam (LEV) is a widely used antiepileptic drug that is also associated with the reversal of cognitive dysfunction. The long-lasting effect of LEV treatment and its participation in synaptic plasticity have not been explored in early chronic epilepsy. Therefore, through the measurement of evoked field potentials, this study aimed to comprehensively identify the alterations in the excitability and the short-term (depression/facilitation) and long-term synaptic plasticity (long-term potentiation, LTP) of the dentate gyrus of the hippocampus in a lithium–pilocarpine rat model of TLE, as well as their possible restoration by LEV (1 week; 300 mg/kg/day). TLE increased the population spike (PS) amplitude (input/output curve); interestingly, LEV treatment partially reduced this hyperexcitability. Furthermore, TLE augmented synaptic depression, suppressed paired-pulse facilitation, and reduced PS-LTP; however, LEV did not alleviate such alterations. Conversely, the excitatory postsynaptic potential (EPSP)-LTP of TLE rats was comparable to that of control rats and was decreased by LEV. LEV caused a long-lasting attenuation of basal hyperexcitability but did not restore impaired synaptic plasticity in the early chronic phase of TLE.
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15
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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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Disabling Gβγ-SNAP-25 interaction in gene-targeted mice results in enhancement of long-term potentiation at Schaffer collateral-CA1 synapses in the hippocampus. Neuroreport 2020; 30:695-699. [PMID: 31095110 DOI: 10.1097/wnr.0000000000001258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Three SNARE proteins, SNAP-25, syntaxin 1A, and VAMP2 or synaptobrevin 2, constitute the minimal functional machinery needed for the regulated secretion of neurotransmitters. Dynamic changes in the regulated release of neurotransmitters are associated with the induction of long-term plasticity at central synapses. In-vitro studies have validated the C-terminus of SNAP-25 as a target for inhibitory Gi/o-coupled G-protein coupled receptors at a number of synapses. The physiological consequences of the interaction between Gi/o proteins and SNAP-25 in the context of activity-dependent long-term synaptic plasticity are not well understood. Here, we report direct ex-vivo evidence of the involvement of the C-terminus of SNAP-25 in inducing long-term potentiation of synaptic strength at Schaffer collateral-CA1 synapses using a gene-targeted mouse model with truncated C-terminus (carboxyl terminus) of SNAP-25. It has been shown previously that truncation of the three extreme C-terminal residues in SNAP-25[INCREMENT]3 homozygote mice reduces its interaction with the inhibitory Gβγ subunits two-fold. In in-vitro hippocampal slices, we show that these SNAP-25[INCREMENT]3 mice express significantly larger magnitude of long-term potentiation at hippocampal Schaffer collateral-CA1 synapses.
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17
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Tong D, Godale CM, Kadakia FK, Gu Z, Danzer CS, Alghamdi A, Zhao P, Loepke AW, Danzer SC. Immature murine hippocampal neurones do not develop long-term structural changes after a single isoflurane exposure. Br J Anaesth 2019; 123:818-826. [DOI: 10.1016/j.bja.2019.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 07/17/2019] [Accepted: 08/08/2019] [Indexed: 10/25/2022] Open
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18
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Upreti C, Konstantinov E, Kassabov SR, Bailey CH, Kandel ER. Serotonin Induces Structural Plasticity of Both Extrinsic Modulating and Intrinsic Mediating Circuits In Vitro in Aplysia Californica. Cell Rep 2019; 28:2955-2965.e3. [PMID: 31509754 DOI: 10.1016/j.celrep.2019.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/27/2018] [Accepted: 07/31/2019] [Indexed: 01/29/2023] Open
Abstract
Long-term sensitization of the gill withdrawal reflex in Aplysia requires heterosynaptic, modulatory input that is mediated in part by the growth of new synaptic connections between sensory neurons and their follower cells (intrinsic mediating circuit). Whether modulatory interneurons (the extrinsic modulatory circuit) also display learning-related structural synaptic plasticity remains unknown. To test this idea, we added a bona fide serotonergic modulatory neuron, the metacerebral cell (MCC), to sensory-motor neuron co-cultures and examined the modulating presynaptic varicosities of MCCs before and after repeated pulses of serotonin (5-HT) that induced long-term facilitation (LTF). We observed robust growth of new serotonergic varicosities that were positive for serotonin and capable of synaptic recycling. Our findings demonstrate that, in addition to structural changes in the intrinsic mediating circuit, there are also significant learning-related structural changes in the extrinsic modulating circuit, and these changes might provide a cellular mechanism for savings and for spread of memory.
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Affiliation(s)
- Chirag Upreti
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; New York State Psychiatric Institute, New York, NY 10032, USA
| | | | - Stefan R Kassabov
- Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Craig H Bailey
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Kavli Institute for Brain Science, New York, NY 10027, USA
| | - Eric R Kandel
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Kavli Institute for Brain Science, New York, NY 10027, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10027, USA.
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19
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Lucchese G. Herpesviruses, autoimmunity and epilepsy: Peptide sharing and potential cross-reactivity with human synaptic proteins. Autoimmun Rev 2019; 18:102367. [PMID: 31404705 DOI: 10.1016/j.autrev.2019.102367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 12/11/2022]
Abstract
Aggregation of immuno-proteomic data reveals that i) herpesviruses and synaptic proteins -in particular Synapsin-1 and Bassoon - share a large number of hexapeptides that also recur in hundreds of epitopes experimentally validated as immunopositive in the human host, and ii) the shared peptides are also spread among human epilepsy-related proteins. The data indicate that cross-reactive processes may be associated with pathogenetic mechanisms in epilepsy, thus suggesting a role of autoimmunity in etiopathology of epilepsies after herpesvirus-infections.
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Affiliation(s)
- Guglielmo Lucchese
- University of Greifswald, Department of Neurology, Ferdinand-Sauerbruch-Straße, Greifswald 17495, Germany; Goldsmiths, University of London, Department of Computing, Lewisham Way, New Cross, London SE14 6NW, United Kingdom.
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20
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孙 智, 陈 倩, 李 明, 马 维, 赵 旭, 黄 卓. [Chronic phosphoproteomic in temporal lobe epilepsy mouse models induced by kainic acid]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2019; 51:197-205. [PMID: 30996354 PMCID: PMC7441195 DOI: 10.19723/j.issn.1671-167x.2019.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Indexed: 06/09/2023]
Abstract
OBJECTIVE To investigate functions of proteins and signaling pathways involved in epileptogenesis during the chronic stage of temporal lobe epilepsy in mouse models. METHODS Kainic acid-induced temporal lobe epilepsy models were conducted, when reaching stage 4 using racine scale, the mice of experimental group were supposed to be successfully established. Pentobarbital sodium was injected to stop epileptic seizure in case of death. Twenty-eight days after the kainic acid injection, when the experimental group generally turned into chronic spontaneous seizures, mice hippocampal tissues were extracted from the control and the experimental groups respectively for phosphoproteomic. Enriched phosphorylated proteins were detected using mass spectrometry, only the proteins whose density was greater than 106 were analyzed by matching the Gene Ontology (GO) database, Kyoto Encyclopedia of Genes and Genomes (KEGG) database and STRING database to detect proteins involved in epileptogenesis in protein functions, signaling pathways and protein-protein interaction respectively. After that, literatures were reviewed about the key proteins. RESULTS (1) Total of 12 697 phosphorylation sites of enriched proteins were detected by mass spectrometry, and there were 159 sites whose phosphorylation levels were significantly different from the control (P<0.001). (2) GO database showed that 35.7% of the 159 sites were about "catalytic activity", 39.5% were about "binding" and 20.8% were about "cell communication", and the 159 proteins also participated in many biological processes, such as "primary metabolic process" "response to stimulus" "developmental process" "localization" and "phosphate-containing compound metabolic process". (3) KEGG database showed that the 159 protein sites mainly involved in 10 signaling pathways: glutamatergic synapse, Ras signaling pathway, African trypanosomiasis, Cocaine addiction, Circadian entrainment, Amyotrophic lateral sclerosis (ALS), Long-term potentiation, Endocytosis, Gap junction, Nicotine addiction. (4) STRING database showed that the protein-protein interaction network formed by the 159 proteins was focused on Grin1/Dlg3, Arhgef 2/Arhgap33/Tiam1 and Sptnb1/3/4/Add3/Ank2 protein group respectively. (5) Phosphorylation levels of Grin1, Arhgef 2, Arhgap33, Tiam1, Sptbn1/2/4 and Ank2 in experimental group were significantly higher than in the control (P<0.001). CONCLUSION Phosphoproteomic illustrated integral distribution of phosphorylated proteins at the chronic stage of temporal lobe epilepsy in the mouse model. Literatures showed that most key proteins were closely related to epileptogenesis, suggesting that some proteins or signaling pathways may play a role in epileptogenesis, such as dopamine and Kir3.1.
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Affiliation(s)
- 智明 孙
- 北京大学药学院分子与细胞药理学系 天然药物与仿生药物国家重点实验室 系统生物医学研究所, 北京 100191Institute of Systems Biomedicine, State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Science, Beijing 100191, China
| | - 倩 陈
- 北京大学药学院分子与细胞药理学系 天然药物与仿生药物国家重点实验室 系统生物医学研究所, 北京 100191Institute of Systems Biomedicine, State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Science, Beijing 100191, China
| | - 明华 李
- 北京大学药学院分子与细胞药理学系 天然药物与仿生药物国家重点实验室 系统生物医学研究所, 北京 100191Institute of Systems Biomedicine, State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Science, Beijing 100191, China
| | - 维宁 马
- 中国医科大学附属盛京医院神经外科, 沈阳 110000Department of Neurosurgery, Sheng Jing Hospital affiliated to China Medical University, Shenyang 110000, China
| | - 旭阳 赵
- 北京大学药学院分子与细胞药理学系 天然药物与仿生药物国家重点实验室 系统生物医学研究所, 北京 100191Institute of Systems Biomedicine, State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Science, Beijing 100191, China
- 北京大学基础医学院北京肿瘤系统生物学重点实验室, 北京 100191Beijing Key Laboratory of Tumor Systems Biology, Peking University School of Basic Medical Science, Beijing 100191, China
| | - 卓 黄
- 北京大学药学院分子与细胞药理学系 天然药物与仿生药物国家重点实验室 系统生物医学研究所, 北京 100191Institute of Systems Biomedicine, State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Science, Beijing 100191, China
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Freitas MLD, Oliveira CVD, Mello FK, Funck VR, Fighera MR, Royes LFF, Furian AF, Larrick JW, Oliveira MS. Na +, K +-ATPase Activating Antibody Displays in vitro and in vivo Beneficial Effects in the Pilocarpine Model of Epilepsy. Neuroscience 2018. [PMID: 29522855 DOI: 10.1016/j.neuroscience.2018.02.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Na+, K+-ATPase is an important regulator of brain excitability. Accordingly, compelling evidence indicates that impairment of Na+, K+-ATPase activity contributes to seizure activity in epileptic mice and human with epilepsy. In addition, this enzyme is crucial for plasma membrane transport of water, glucose and several chemical mediators, including glutamate, the major excitatory transmitter in the mammalian brain. Since glucose hypometabolism and increased glutamate levels occur in clinical and experimental epilepsy, we aimed the present study to investigate whether activation of Na+, K+-ATPase activity with specific antibody (DRRSAb) would improve glucose uptake and glutamate release in pilocarpine-treated mice. We found decreased uptake of the glucose fluorescent analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-il)amino]-2-desoxi-d-glucose (2-NBDG) in cerebral slices from pilocarpine-treated animals. Interestingly, decreased 2-NBDG uptake was not detected in DRRSAb-treated slices, suggesting a protective effect of the Na+, K+-ATPase activator. Moreover, DRRSAb prevented the increase in glutamate levels in the incubation media of slices from pilocarpine-treated mice. In addition, in vivo intrahippocampal injection of DRRSAb restored crossing activity of pilocarpine-treated mice in the open-field test. Overall, the present data further support the hypothesis that activation of the Na+, K+-ATPase is a promising therapeutic strategy for epilepsy.
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Affiliation(s)
| | | | | | - Vinícius Rafael Funck
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michele Rechia Fighera
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Ana Flávia Furian
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - James W Larrick
- Panorama Research Institute, 1230 Bordeaux Dr, Sunnyvale, CA 94089, United States
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22
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Bentea E, Moore C, Deneyer L, Verbruggen L, Churchill MJ, Hood RL, Meshul CK, Massie A. Plastic changes at corticostriatal synapses predict improved motor function in a partial lesion model of Parkinson’s disease. Brain Res Bull 2017; 130:257-267. [DOI: 10.1016/j.brainresbull.2017.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 02/16/2017] [Indexed: 12/15/2022]
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23
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Axonal Type III Nrg1 Controls Glutamate Synapse Formation and GluA2 Trafficking in Hippocampal-Accumbens Connections. eNeuro 2017; 4:eN-NWR-0232-16. [PMID: 28275713 PMCID: PMC5329619 DOI: 10.1523/eneuro.0232-16.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/23/2017] [Accepted: 02/06/2017] [Indexed: 11/21/2022] Open
Abstract
Altered neuregulin 1 (Nrg1)/ErbB signaling and glutamatergic hypofunction have been implicated in the pathophysiology of schizophrenia. Here, we employed gene chimeric ventral hippocampus (vHipp)-nucleus accumbens (nAcc) coculture from mouse, electrophysiology, immunocytochemistry, FM1-43 vesicle fusion, and electron microscopy techniques to examine the pre- and postsynaptic mechanisms of genetic deficits in Nrg1/ErbB signaling-induced glutamatergic dysfunctions. Reduced presynaptic type III Nrg1 expression along vHipp axons decreases the number of glutamate synapses and impairs GluA2 trafficking in the postsynaptic nAcc neurons, resulting in decreased frequency and amplitude of miniature EPSCs (mEPSCs). Reduced expression of axonal type III Nrg1 along vHipp projections also decreases functional synaptic vesicle (SV) clustering and vesicular trafficking to presynaptic vHipp axonal terminals. These findings suggest that Nrg1/ErbB signaling modulate glutamatergic transmission via both pre- and postsynaptic mechanisms.
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Fu P, Wen Y, Xiong Y, Zhang Y, Zhang H, Xie Y, Shi Q. Abnormal Expression of FBXL20 in Refractory Epilepsy Patients and a Pilocarpine-Induced Rat Model. Neurochem Res 2016; 41:3020-3031. [PMID: 27502938 DOI: 10.1007/s11064-016-2021-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 07/08/2016] [Accepted: 07/28/2016] [Indexed: 10/21/2022]
Abstract
E3 ubiquitin ligases are important protein-modifying enzymes involved in the pathogenesis of a variety of neurodegenerative diseases. F-box and leucine-rich repeat protein 20 (FBXL20), an E3 ubiquitin ligase widely expressed in the central nervous system, plays an important role in the ubiquitin-dependent degradation of regulating synaptic membrane exocytosis 1 (RIM1), which is an important factor in the release of synaptic vesicles. FBXL20 has been associated with a variety of neurodegenerative diseases; thus, we hypothesized that FBXL20 is involved in the development of epilepsy. Herein, we used immunofluorescence staining, immunohistochemistry and western blotting to determine the expression pattern of FBXL20 in temporal lobe epilepsy patients and pilocarpine-induced epilepsy animal models. We also injected SD rats with lentivirus-vector mediated overexpression of FBXL20. The results showed that FBXL20 is expressed in the membrane and the cytoplasm of cortical neurons, and overexpression of FBXL20 decreased the onset level of spontaneous seizure, the frequency and duration of seizures. Additionally, FBXL20 protein level was decreased but RIM1 protein level was increased in the epileptic group compared with the LV-FBXL20 and LV-GFP group. These findings in humans were consistent with the results from a pilocarpine-induced animal model of chronic epilepsy. Thus, abnormal expression of FBXL20 might play an important role in the development of epilepsy.
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Affiliation(s)
- Pengfei Fu
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - YueTao Wen
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Yan Xiong
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Yanke Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Haiyang Zhang
- Department of Pediatric Intensive Care Unit, West China Second University Hospital, Sichuan University, Chengdu, 610000, China
| | - Yanfeng Xie
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Quanhong Shi
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
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Löscher W, Gillard M, Sands ZA, Kaminski RM, Klitgaard H. Synaptic Vesicle Glycoprotein 2A Ligands in the Treatment of Epilepsy and Beyond. CNS Drugs 2016; 30:1055-1077. [PMID: 27752944 PMCID: PMC5078162 DOI: 10.1007/s40263-016-0384-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The synaptic vesicle glycoprotein SV2A belongs to the major facilitator superfamily (MFS) of transporters and is an integral constituent of synaptic vesicle membranes. SV2A has been demonstrated to be involved in vesicle trafficking and exocytosis, processes crucial for neurotransmission. The anti-seizure drug levetiracetam was the first ligand to target SV2A and displays a broad spectrum of anti-seizure activity in various preclinical models. Several lines of preclinical and clinical evidence, including genetics and protein expression changes, support an important role of SV2A in epilepsy pathophysiology. While the functional consequences of SV2A ligand binding are not fully elucidated, studies suggest that subsequent SV2A conformational changes may contribute to seizure protection. Conversely, the recently discovered negative SV2A modulators, such as UCB0255, counteract the anti-seizure effect of levetiracetam and display procognitive properties in preclinical models. More broadly, dysfunction of SV2A may also be involved in Alzheimer's disease and other types of cognitive impairment, suggesting potential novel therapies for levetiracetam and its congeners. Furthermore, emerging data indicate that there may be important roles for two other SV2 isoforms (SV2B and SV2C) in the pathogenesis of epilepsy, as well as other neurodegenerative diseases. Utilization of recently developed SV2A positron emission tomography ligands will strengthen and reinforce the pharmacological evidence that SV2A is a druggable target, and will provide a better understanding of its role in epilepsy and other neurological diseases, aiding in further defining the full therapeutic potential of SV2A modulation.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, 30559, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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Saffarzadeh F, Eslamizade M, Mousavi S, Abraki S, Hadjighassem M, Gorji A. TRPV1 receptors augment basal synaptic transmission in CA1 and CA3 pyramidal neurons in epilepsy. Neuroscience 2016; 314:170-8. [DOI: 10.1016/j.neuroscience.2015.11.045] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/06/2015] [Accepted: 11/19/2015] [Indexed: 01/13/2023]
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Wong SB, Cheng SJ, Hung WC, Lee WT, Min MY. Rosiglitazone Suppresses In Vitro Seizures in Hippocampal Slice by Inhibiting Presynaptic Glutamate Release in a Model of Temporal Lobe Epilepsy. PLoS One 2015; 10:e0144806. [PMID: 26659605 PMCID: PMC4685987 DOI: 10.1371/journal.pone.0144806] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 11/24/2015] [Indexed: 12/13/2022] Open
Abstract
Peroxisomal proliferator-activated receptor gamma (PPARγ) is a nuclear hormone receptor whose agonist, rosiglitazone has a neuroprotective effect to hippocampal neurons in pilocarpine-induced seizures. Hippocampal slice preparations treated in Mg2+ free medium can induce ictal and interictal-like epileptiform discharges, which is regarded as an in vitro model of N-methyl-D-aspartate (NMDA) receptor-mediated temporal lobe epilepsy (TLE). We applied rosiglitazone in hippocampal slices treated in Mg2+ free medium. The effects of rosiglitazone on hippocampal CA1-Schaffer collateral synaptic transmission were tested. We also examined the neuroprotective effect of rosiglitazone toward NMDA excitotoxicity on cultured hippocampal slices. Application of 10μM rosiglitazone significantly suppressed amplitude and frequency of epileptiform discharges in CA1 neurons. Pretreatment with the PPARγ antagonist GW9662 did not block the effect of rosiglitazone on suppressing discharge frequency, but reverse the effect on suppressing discharge amplitude. Application of rosiglitazone suppressed synaptic transmission in the CA1-Schaffer collateral pathway. By miniature excitatory-potential synaptic current (mEPSC) analysis, rosiglitazone significantly suppressed presynaptic neurotransmitter release. This phenomenon can be reversed by pretreating PPARγ antagonist GW9662. Also, rosiglitazone protected cultured hippocampal slices from NMDA-induced excitotoxicity. The protective effect of 10μM rosiglitazone was partially antagonized by concomitant high dose GW9662 treatment, indicating that this effect is partially mediated by PPARγ receptors. In conclusion, rosiglitazone suppressed NMDA receptor-mediated epileptiform discharges by inhibition of presynaptic neurotransmitter release. Rosiglitazone protected hippocampal slice from NMDA excitotoxicity partially by PPARγ activation. We suggest that rosiglitazone could be a potential agent to treat patients with TLE.
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MESH Headings
- Action Potentials/drug effects
- Anilides/pharmacology
- Animals
- CA1 Region, Hippocampal/drug effects
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/pathology
- Culture Media/chemistry
- Culture Media/pharmacology
- Epilepsy, Temporal Lobe/drug therapy
- Epilepsy, Temporal Lobe/genetics
- Epilepsy, Temporal Lobe/metabolism
- Epilepsy, Temporal Lobe/pathology
- Excitatory Postsynaptic Potentials/drug effects
- Gene Expression Regulation
- Glutamic Acid/metabolism
- Magnesium/pharmacology
- Microtomy
- Models, Biological
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Neuroprotective Agents/antagonists & inhibitors
- Neuroprotective Agents/pharmacology
- PPAR gamma/antagonists & inhibitors
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, N-Methyl-D-Aspartate/agonists
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
- Rosiglitazone
- Seizures/drug therapy
- Seizures/genetics
- Seizures/metabolism
- Seizures/pathology
- Synaptic Transmission/drug effects
- Thiazolidinediones/antagonists & inhibitors
- Thiazolidinediones/pharmacology
- Tissue Culture Techniques
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Affiliation(s)
- Shi-Bing Wong
- Department of Pediatrics, Taipei Tzu Chi General Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan
- Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Sin-Jhong Cheng
- Neuroscience Program in Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Sciences; Academia Sinica, Taipei, Taiwan
| | - Wei-Chen Hung
- Department of Pediatrics, Taipei Tzu Chi General Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan
| | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail: (WTL); (MYM)
| | - Ming-Yuan Min
- Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan
- * E-mail: (WTL); (MYM)
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Maruo T, Mandai K, Takai Y, Mori M. Activity-dependent alteration of the morphology of a hippocampal giant synapse. Mol Cell Neurosci 2015; 71:25-33. [PMID: 26687760 DOI: 10.1016/j.mcn.2015.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 11/16/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022] Open
Abstract
Activity-dependent synaptic plasticity is a fundamental cellular process for learning and memory. While electrophysiological plasticity has been intensively studied, morphological plasticity is less clearly understood. This study investigated the effect of presynaptic stimulation on the morphology of a giant mossy fiber-CA3 pyramidal cell synapse, and found that the mossy fiber bouton altered its morphology with an increase in the number of segments. This activity-dependent alteration in morphology required the activation of glutamate receptors and an increase in postsynaptic calcium concentration. In addition, the intercellular retrograde messengers nitric oxide and arachidonic acid were necessary. Simultaneous recordings demonstrated that the morphological complexity of the presynaptic bouton and the amplitude of excitatory postsynaptic currents were well correlated. Thus, a single mossy fiber synapse has the potential for activity-dependent morphological plasticity at the presynaptic bouton, which may be important for learning and memory.
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Affiliation(s)
- Tomohiko Maruo
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan
| | - Kenji Mandai
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan
| | - Yoshimi Takai
- Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan.
| | - Masahiro Mori
- Division of Neurophysiology, Department of Cellular Physiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; Faculty of Health Sciences, Kobe University Graduate School of Health Sciences, 7-10-2, Tomogaoka, Suma-ku, Kobe 654-0142, Japan; CREST, Japan Science and Technology Agency, Kobe BT Center, 1-5-6 Minatojimaminami-machi, Chuo-ku, Kobe 650-0047, Japan.
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Xu LH, Xie H, Shi ZH, Du LD, Wing YK, Li AM, Ke Y, Yung WH. Critical Role of Endoplasmic Reticulum Stress in Chronic Intermittent Hypoxia-Induced Deficits in Synaptic Plasticity and Long-Term Memory. Antioxid Redox Signal 2015; 23:695-710. [PMID: 25843188 PMCID: PMC4580307 DOI: 10.1089/ars.2014.6122] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AIMS This study examined the role of endoplasmic reticulum (ER) stress in mediating chronic intermittent hypoxia (IH)-induced neurocognitive deficits. We designed experiments to demonstrate that ER stress is initiated in the hippocampus under chronic IH and determined its role in apoptotic cell death, impaired synaptic structure and plasticity, and memory deficits. RESULTS Two weeks of IH disrupted ER fine structure and upregulated ER stress markers, glucose-regulated protein 78, caspase-12, and C/EBP homologous protein, in the hippocampus, which could be suppressed by ER stress inhibitors, tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid. Meanwhile, ER stress induced apoptosis via decreased Bcl-2, promoted reactive oxygen species production, and increased malondialdehyde formation and protein carbonyl, as well as suppressed mitochondrial function. These effects were largely prevented by ER stress inhibitors. On the other hand, suppression of oxidative stress could reduce ER stress. In addition, the length of the synaptic active zone and number of mature spines were reduced by IH. Long-term recognition memory and spatial memory were also impaired, which was accompanied by reduced long-term potentiation in the Schaffer collateral pathway. These effects were prevented by coadministration of the TUDCA. INNOVATION AND CONCLUSION These results show that ER stress plays a critical role in underlying memory deficits in obstructive sleep apnea (OSA)-associated IH. Attenuators of ER stress may serve as novel adjunct therapeutic agents for ameliorating OSA-induced neurocognitive impairment.
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Affiliation(s)
- Lin-Hao Xu
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Hui Xie
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Zhi-Hui Shi
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Li-Da Du
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Yun-Kwok Wing
- 2 Department of Psychiatry, Prince of Wales Hospital , Shatin, Hong Kong, China
| | - Albert M Li
- 3 Department of Pediatrics, Prince of Wales Hospital , Shatin, Hong Kong, China
| | - Ya Ke
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Wing-Ho Yung
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
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Funck V, Ribeiro L, Pereira L, de Oliveira C, Grigoletto J, Della-Pace I, Fighera M, Royes L, Furian A, Larrick J, Oliveira M. Contrasting effects of Na+, K+-ATPase activation on seizure activity in acute versus chronic models. Neuroscience 2015; 298:171-9. [DOI: 10.1016/j.neuroscience.2015.04.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 03/02/2015] [Accepted: 04/14/2015] [Indexed: 10/23/2022]
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Snowball A, Schorge S. Changing channels in pain and epilepsy: Exploiting ion channel gene therapy for disorders of neuronal hyperexcitability. FEBS Lett 2015; 589:1620-34. [PMID: 25979170 DOI: 10.1016/j.febslet.2015.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/29/2015] [Accepted: 05/02/2015] [Indexed: 11/25/2022]
Abstract
Chronic pain and epilepsy together affect hundreds of millions of people worldwide. While traditional pharmacotherapy provides essential relief to the majority of patients, a large proportion remains resistant, and surgical intervention is only possible for a select few. As both disorders are characterised by neuronal hyperexcitability, manipulating the expression of the most direct modulators of excitability - ion channels - represents an attractive common treatment strategy. A number of viral gene therapy approaches have been explored to achieve this. These range from the up- or down-regulation of channels that control excitability endogenously, to the delivery of exogenous channels that permit manipulation of excitability via optical or chemical means. In this review we highlight the key experimental successes of each approach and discuss the challenges facing their clinical translation.
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Affiliation(s)
- Albert Snowball
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Stephanie Schorge
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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32
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Lillis KP, Dulla C, Maheshwari A, Coulter D, Mody I, Heinemann U, Armbruster M, Žiburkus J. WONOEP appraisal: molecular and cellular imaging in epilepsy. Epilepsia 2015; 56:505-13. [PMID: 25779014 PMCID: PMC4397142 DOI: 10.1111/epi.12939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2015] [Indexed: 01/01/2023]
Abstract
Great advancements have been made in understanding the basic mechanisms of ictogenesis using single-cell electrophysiology (e.g., patch clamp, sharp electrode), large-scale electrophysiology (e.g., electroencephalography [EEG], field potential recording), and large-scale imaging (magnetic resonance imaging [MRI], positron emission tomography [PET], calcium imaging of acetoxymethyl ester [AM] dye-loaded tissue). Until recently, it has been challenging to study experimentally how population rhythms emerge from cellular activity. Newly developed optical imaging technologies hold promise for bridging this gap by making it possible to simultaneously record the many cellular elements that comprise a neural circuit. Furthermore, easily accessible genetic technologies for targeting expression of fluorescent protein-based indicators make it possible to study, in animal models of epilepsy, epileptogenic changes to neural circuits over long periods. In this review, we summarize some of the latest imaging tools (fluorescent probes, gene delivery methods, and microscopy techniques) that can lead to the advancement of cell- and circuit-level understanding of epilepsy, which in turn may inform and improve development of next generation antiepileptic and antiepileptogenic drugs.
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Affiliation(s)
- Kyle P Lillis
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A; Harvard Medical School, Boston, Massachusetts, U.S.A
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LaSarge CL, Santos VR, Danzer SC. PTEN deletion from adult-generated dentate granule cells disrupts granule cell mossy fiber axon structure. Neurobiol Dis 2015; 75:142-50. [PMID: 25600212 PMCID: PMC4351143 DOI: 10.1016/j.nbd.2014.12.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/17/2014] [Accepted: 12/26/2014] [Indexed: 01/30/2023] Open
Abstract
Dysregulation of the mTOR-signaling pathway is implicated in the development of temporal lobe epilepsy. In mice, deletion of PTEN from hippocampal dentate granule cells leads to mTOR hyperactivation and promotes the rapid onset of spontaneous seizures. The mechanism by which these abnormal cells initiate epileptogenesis, however, is unclear. PTEN-knockout granule cells develop abnormally, exhibiting morphological features indicative of increased excitatory input. If these cells are directly responsible for seizure genesis, it follows that they should also possess increased output. To test this prediction, dentate granule cell axon morphology was quantified in control and PTEN-knockout mice. Unexpectedly, PTEN deletion increased giant mossy fiber bouton spacing along the axon length, suggesting reduced innervation of CA3. Increased width of the mossy fiber axon pathway in stratum lucidum, however, which likely reflects an unusual increase in mossy fiber axon collateralization in this region, offsets the reduction in boutons per axon length. These morphological changes predict a net increase in granule cell innervation of CA3. Increased diameter of axons from PTEN-knockout cells would further enhance granule cell communication with CA3. Altogether, these findings suggest that amplified information flow through the hippocampal circuit contributes to seizure occurrence in the PTEN-knockout mouse model of temporal lobe epilepsy.
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Affiliation(s)
- Candi L LaSarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Victor R Santos
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Physiology, Ribeirão Preto Medical School, Ribeirão Preto, SP, Brazil
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Anesthesia, University of Cincinnati, Cincinnati, OH 45267, USA; Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45267, USA.
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Urban-Ciecko J, Wen JA, Parekh PK, Barth AL. Experience-dependent regulation of presynaptic NMDARs enhances neurotransmitter release at neocortical synapses. ACTA ACUST UNITED AC 2014; 22:47-55. [PMID: 25512577 PMCID: PMC4274331 DOI: 10.1101/lm.035741.114] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sensory experience can selectively alter excitatory synaptic strength at neocortical synapses. The rapid increase in synaptic strength induced by selective whisker stimulation (single-row experience/SRE, where all but one row of whiskers has been removed from the mouse face) is due, at least in part, to the trafficking of AMPA receptors (AMPARs) to the post-synaptic membrane, and is developmentally regulated. How enhanced sensory experience can alter presynaptic release properties in the developing neocortex has not been investigated. Using paired-pulse stimulation at layer 4-2/3 synapses in acute brain slices, we found that presynaptic release probability progressively increases in the spared-whisker barrel column over the first 24 h of SRE. Enhanced release probability can be at least partly attributed to presynaptic NMDA receptors (NMDARs). We find that the influence of presynaptic NMDARs in enhancing EPSC amplitude markedly increases during SRE. This occurs at the same time when recently potentiated synapses become highly susceptible to a NMDAR-dependent form of synaptic depression, during the labile phase of plasticity. Thus, these data show that augmented sensory stimulation can enhance release probability at layer 4-2/3 synapses and enhance the function of presynaptic NMDARs. Because presynaptic NMDARs have been linked to synaptic depression at layer 4-2/3 synapses, we propose that SRE-dependent up-regulation of presynaptic NMDARs is responsible for enhanced synaptic depression during the labile stage of plasticity.
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Affiliation(s)
- Joanna Urban-Ciecko
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Jing A Wen
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Puja K Parekh
- Center for Neuroscience at the University of Pittsburgh, Department of Psychiatry, Pittsburgh, Pennsylvania 15219, USA
| | - Alison L Barth
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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Yamawaki R, Thind K, Buckmaster PS. Blockade of excitatory synaptogenesis with proximal dendrites of dentate granule cells following rapamycin treatment in a mouse model of temporal lobe epilepsy. J Comp Neurol 2014; 523:281-97. [PMID: 25234294 DOI: 10.1002/cne.23681] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/09/2014] [Accepted: 09/16/2014] [Indexed: 12/13/2022]
Abstract
Inhibiting the mammalian target of rapamycin (mTOR) signaling pathway with rapamycin blocks granule cell axon (mossy fiber) sprouting after epileptogenic injuries, including pilocarpine-induced status epilepticus. However, it remains unclear whether axons from other types of neurons sprout into the inner molecular layer and synapse with granule cell dendrites despite rapamycin treatment. If so, other aberrant positive-feedback networks might develop. To test this possibility stereological electron microscopy was used to estimate the numbers of excitatory synapses in the inner molecular layer per hippocampus in pilocarpine-treated control mice, in mice 5 days after pilocarpine-induced status epilepticus, and after status epilepticus and daily treatment beginning 24 hours later with rapamycin or vehicle for 2 months. The optical fractionator method was used to estimate numbers of granule cells in Nissl-stained sections so that numbers of excitatory synapses in the inner molecular layer per granule cell could be calculated. Control mice had an average of 2,280 asymmetric synapses in the inner molecular layer per granule cell, which was reduced to 63% of controls 5 days after status epilepticus, recovered to 93% of controls in vehicle-treated mice 2 months after status epilepticus, but remained at only 63% of controls in rapamycin-treated mice. These findings reveal that rapamycin prevented excitatory axons from synapsing with proximal dendrites of granule cells and raise questions about the recurrent excitation hypothesis of temporal lobe epilepsy.
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Affiliation(s)
- Ruth Yamawaki
- Department of Comparative Medicine, Stanford University, Stanford, CA, 94305
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Stockler S, Corvera S, Lambright D, Fogarty K, Nosova E, Leonard D, Steinfeld R, Ackerley C, Shyr C, Au N, Selby K, van Allen M, Vallance H, Wevers R, Watkins D, Rosenblatt D, Ross CJ, Conibear E, Wasserman W, van Karnebeek C. Single point mutation in Rabenosyn-5 in a female with intractable seizures and evidence of defective endocytotic trafficking. Orphanet J Rare Dis 2014; 9:141. [PMID: 25233840 PMCID: PMC4177245 DOI: 10.1186/s13023-014-0141-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 08/25/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We report a 6.5 year-old female with a homozygous missense mutation in ZFYVE20, encoding Rabenosyn-5 (Rbsn-5), a highly conserved multi-domain protein implicated in receptor-mediated endocytosis. The clinical presentation includes intractable seizures, developmental delay, microcephaly, dysostosis, osteopenia, craniofacial dysmorphism, macrocytosis and megaloblastoid erythropoiesis. Biochemical findings include transient cobalamin deficiency, severe hypertriglyceridemia upon ketogenic diet, microalbuminuria and partial cathepsin D deficiency. METHODS AND RESULTS Whole exome sequencing followed by Sanger sequencing confirmed a rare (frequency:0.003987) homozygous missense mutation, g.15,116,371 G > A (c.1273G > A), in ZFYVE20 resulting in an amino acid change from Glycine to Arginine at position 425 of the Rbsn protein (p.Gly425Arg), as the only mutation segregating with disease in the family. Studies in fibroblasts revealed expression and localization of Rbsn-5G425R in wild-type manner, but a 50% decrease in transferrin accumulation, which is corrected by wild-type allele transfection. Furthermore, the patient's fibroblasts displayed an impaired proliferation rate, cytoskeletal and lysosomal abnormalities. CONCLUSION These results are consistent with a functional defect in the early endocytic pathway resulting from mutation in Rbsn-5, which secondarily disrupts multiple cellular functions dependent on endocytosis, leading to a severe multi-organ disorder.
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Lasarge CL, Danzer SC. Mechanisms regulating neuronal excitability and seizure development following mTOR pathway hyperactivation. Front Mol Neurosci 2014; 7:18. [PMID: 24672426 PMCID: PMC3953715 DOI: 10.3389/fnmol.2014.00018] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/27/2014] [Indexed: 01/19/2023] Open
Abstract
The phosphatidylinositol-3-kinase/phosphatase and tensin homolog (PTEN)-mammalian target of rapamycin (mTOR) pathway regulates a variety of neuronal functions, including cell proliferation, survival, growth, and plasticity. Dysregulation of the pathway is implicated in the development of both genetic and acquired epilepsies. Indeed, several causal mutations have been identified in patients with epilepsy, the most prominent of these being mutations in PTEN and tuberous sclerosis complexes 1 and 2 (TSC1, TSC2). These genes act as negative regulators of mTOR signaling, and mutations lead to hyperactivation of the pathway. Animal models deleting PTEN, TSC1, and TSC2 consistently produce epilepsy phenotypes, demonstrating that increased mTOR signaling can provoke neuronal hyperexcitability. Given the broad range of changes induced by altered mTOR signaling, however, the mechanisms underlying seizure development in these animals remain uncertain. In transgenic mice, cell populations with hyperactive mTOR have many structural abnormalities that support recurrent circuit formation, including somatic and dendritic hypertrophy, aberrant basal dendrites, and enlargement of axon tracts. At the functional level, mTOR hyperactivation is commonly, but not always, associated with enhanced synaptic transmission and plasticity. Moreover, these populations of abnormal neurons can affect the larger network, inducing secondary changes that may explain paradoxical findings reported between cell and network functioning in different models or at different developmental time points. Here, we review the animal literature examining the link between mTOR hyperactivation and epileptogenesis, emphasizing the impact of enhanced mTOR signaling on neuronal form and function.
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Affiliation(s)
- Candi L Lasarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center Cincinnati, OH, USA ; Department of Anesthesia, University of Cincinnati Cincinnati, OH, USA ; Department of Pediatrics, University of Cincinnati Cincinnati, OH, USA
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Zhang YF, Xiong TQ, Tan BH, Song Y, Li SL, Yang LB, Li YC. Pilocarpine-induced epilepsy is associated with actin cytoskeleton reorganization in the mossy fiber-CA3 synapses. Epilepsy Res 2014; 108:379-89. [PMID: 24559838 DOI: 10.1016/j.eplepsyres.2014.01.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 01/21/2014] [Accepted: 01/24/2014] [Indexed: 12/17/2022]
Abstract
Dramatic structural changes have been demonstrated in the mossy fiber-CA3 synapses in the post status epilepticus (SE) animals, suggesting a potential reorganization of filamentous actin (F-actin) network occurring in the hippocampus. However, until now the long-term effects of SE on the synaptic F-actin have still not been reported. In this study, phalloidin labeling combined with confocal microscopy and protein analyses were adopted to investigate the effects of pilocarpine treatment on the F-actin in the C57BL/6 mice. As compared to the controls, there was ∼ 43% reduction in F-actin density in the post SE mice. Quantitative analysis showed that the labeling density and the puncta number were significantly decreased after pilocarpine treatment (p<0.01, n=5 mice per group, Student's t-test). The puncta of F-actin in the post SE group tended to be highly clustered, while those in the controls were generally distributed evenly. The mean puncta size of F-actin puncta was 0.73±0.19μm(2) (n=1102 puncta from 5 SE mice) in the experimental group, significantly larger than that in the controls (0.51±0.10μm(2), n=1983 puncta from 5 aged-matched control mice, p<0.01, Student's t-test). These observations were well consistent with the alterations of postsynaptic densities in the same region, revealed by immunostaining of PSD95, suggesting the reorganization of F-actin occurred mainly postsynaptically. Our results are indicative of important cytoskeletal changes in the mossy fiber-CA3 synapses after pilocarpine treatment, which may contribute to the excessive excitatory output in the hippocampal trisynaptic circuit.
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Affiliation(s)
- Yan-Feng Zhang
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China; Pediatric Neurology, First Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Tian-Qing Xiong
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Bai-Hong Tan
- Laboratory Teaching Center of Basic Medicine, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin Province 130021, PR China
| | - Yan Song
- Nursing College, Beihua University, Jilin, Jilin Province 132013, PR China
| | - Shu-Lei Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Li-Bin Yang
- Pediatric Neurology, First Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Yan-Chao Li
- Department of Histology and Embryology, College of Basic Medical Sciences, Norman Bethune Health Science Center of Jilin University, Changchun, Jilin Province 130021, PR China.
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Casillas-Espinosa PM, Powell KL, O'Brien TJ. Regulators of synaptic transmission: roles in the pathogenesis and treatment of epilepsy. Epilepsia 2013; 53 Suppl 9:41-58. [PMID: 23216578 DOI: 10.1111/epi.12034] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synaptic transmission is the communication between a presynaptic and a postsynaptic neuron, and the subsequent processing of the signal. These processes are complex and highly regulated, reflecting their importance in normal brain functioning and homeostasis. Sustaining synaptic transmission depends on the continuing cycle of synaptic vesicle formation, release, and endocytosis, which requires proteins such as dynamin, syndapin, synapsin, and synaptic vesicle protein 2A. Synaptic transmission is regulated by diverse mechanisms, including presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors and signaling, and modulators of neurotransmission. Neurotransmitters released presynaptically can bind to their postsynaptic receptors, the inhibitory γ-aminobutyric acid (GABA)ergic receptors or the excitatory glutamate receptors. Once released, glutamate activates a variety of postsynaptic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA), kainate, and metabotropic receptors. The activation of the receptors triggers downstream signaling cascades generating a vast array of effects, which can be modulated by a numerous auxiliary regulatory subunits. Moreover, different neuropeptides such as neuropeptide Y, brain-derived neurotrophic factor (BDNF), somatostatin, ghrelin, and galanin, act as regulators of diverse synaptic functions and along with the classic neurotransmitters. Abnormalities in the regulation of synaptic transmission play a critical role in the pathogenesis of numerous brain diseases, including epilepsy. This review focuses on the different mechanisms involved in the regulation of synaptic transmission, which may play a role in the pathogenesis of epilepsy: the presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors, and modulators of neurotransmission, including the mechanism by which drugs can modulate the frequency and severity of epileptic seizures.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- The Departments of Medicine and Neurology, The Royal Melbourne Hospital, The Melbourne Brain Centre, The University of Melbourne, Parkville, Victoria, Australia
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"Please release me, let me go"-changes in presynaptic release following status epilepticus. Epilepsy Curr 2012; 12:170-1. [PMID: 23118598 DOI: 10.5698/1535-7511-12.5.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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