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Baltos JA, Casillas-Espinosa PM, Rollo B, Gregory KJ, White PJ, Christopoulos A, Kwan P, O'Brien TJ, May LT. The role of the adenosine system in epilepsy and its comorbidities. Br J Pharmacol 2024; 181:2143-2157. [PMID: 37076128 DOI: 10.1111/bph.16094] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 03/09/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023] Open
Abstract
Epilepsy is one of the most serious and common chronic neurological conditions, characterised by recurrent hypersynchronous electrical activity in the brain that lead to seizures. Despite over 50 million people being affected worldwide, only ~70% of people with epilepsy have their seizures successfully controlled with current pharmacotherapy, and many experience significant psychiatric and physical comorbidities. Adenosine, a ubiquitous purine metabolite, is a potent endogenous anti-epileptic substance that can abolish seizure activity via the adenosine A1 G protein-coupled receptor. Activation of A1 receptors decreases seizure activity in animal models, including models of drug-resistant epilepsy. Recent advances have increased our understanding of epilepsy comorbidities, highlighting the potential for adenosine receptors to modulate epilepsy-associated comorbidities, including cardiovascular dysfunction, sleep and cognition. This review provides an accessible resource of the current advances in understanding the adenosine system as a therapeutic target for epilepsy and epilepsy-associated comorbidities. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
| | - Ben Rollo
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Karen J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
| | - Paul J White
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Neuromedicines Discovery Centre, Monash University, Melbourne, Victoria, Australia
| | - Patrick Kwan
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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Zhou Q, Zhang N, Wang M, Zhao Q, Zhu S, Kang H. Adenosine kinase gene modified mesenchymal stem cell transplantation retards seizure severity and associated cognitive impairment in a temporal lobe epilepsy rat model. Epilepsy Res 2024; 200:107303. [PMID: 38306957 DOI: 10.1016/j.eplepsyres.2024.107303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 12/05/2023] [Accepted: 01/11/2024] [Indexed: 02/04/2024]
Abstract
PURPOSE Temporal lobe epilepsy (TLE) has a high risk of developing drug resistant and cognitive comorbidities. Adenosine has potential anticonvulsant effects as an inhibitory neurotransmitter, but drugs targeting its receptors and metabolic enzyme has inevitable side effects. Therefore, we investigated adenosine augmentation therapy for seizure control and cognitive comorbidities in TLE animals. METHODS Using lentiviral vectors coexpressing miRNA inhibiting the expression of adenosine kinase (ADK), we produced ADK--rMSC (ADK knockdown rat mesenchymal stem cell). ADK--rMSC and LV-con-rMSC (rMSC transduced by randomized scrambled control sequence) were transplanted into the hippocampus of TLE rat respectively. ADK-+DPCPX group was transplanted with ADK--rMSC and intraperitoneally injected with DPCPX (adenosine A1 receptor antagonist). Seizure behavior, EEG, CA1 pyramidal neuron apoptosis, and behavior in Morris water maze and novel object recognition test were studied RESULTS: Adenosine concentration in the supernatants of 105 ADK--rMSCs was 13.8 ng/ml but not detectable in LV-con-rMSCs. ADK--rMSC (n = 11) transplantation decreased spontaneous recurrent seizure (SRS) duration compared to LV-con-rMSC (n = 11, P < 0.05). CA1 neuron apoptosis was decreased in ADK--rMSC (n = 3, P < 0.05). ADK--rMSC (n = 11) improved the Morris water maze performance of TLE rats compared to LV-con-rMSC (n = 11, escape latency, P < 0.01; entries in target quadrant, P < 0.05). The effect of ADK--rMSC on neuron apoptosis and spatial memory were counteracted by DPCPX. However, ADK--rMSC didn't improve the performance in novel object recognition test. CONCLUSION Adenosine augmentation-based ADK--rMSC transplantation is a promising therapeutic candidate for TLE and related cognitive comorbidities.
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Affiliation(s)
- Qing Zhou
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Na Zhang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang University, Nanchang 330006, People's Republic of China
| | - Man Wang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Qin Zhao
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Huicong Kang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
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Mehranpour M, Sani M, Beirami A, Hasanzadeh M, Taghizadeh M, Banihashemi M, Moghaddam MH, Fathi M, Vakili K, Yaghoobpoor S, Eskandari N, Abdollahifar MA, Bayat AH, Aliaghaei A, Heidari MH. Grafted Sertoli cells prevent neuronal cell death and memory loss induced by seizures. Metab Brain Dis 2023; 38:2735-2750. [PMID: 37851137 DOI: 10.1007/s11011-023-01309-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/04/2023] [Indexed: 10/19/2023]
Abstract
Epilepsy significantly reduces the patient's quality of life, and we still need to develop new therapeutic approaches to control it. Transplantation of cells such as Sertoli cells (SCs), having a potent ability to release a variety of growth and immunoprotective substances, have made them a potential candidate to deal with neurological diseases like epilepsy. Hence, this study aims to evaluate whether SCs transplant effectively protects the hippocampus astrocytes and neurons to oppose seizure damage. For this purpose, the effects of bilateral intrahippocampal transplantation of SCs were investigated on the rats with the pentylenetetrazol (PTZ) induced seizure. After one-month, post-graft analysis was performed regarding behavior, immunohistopathology, and the distribution of the hippocampal cells. Our findings showed SCs transplantation reduced astrogliosis, astrocytes process length, the number of branches, and intersections distal to the soma of the hippocampus in the seizure group. In rats with grafted SCs, there was a drop in the hippocampal caspase-3 expression. Moreover, the SCs showed another protective impact, as shown by an improvement in pyramidal neurons' number and spatial distribution. The findings suggested that SCs transplantation can potently modify astrocytes' reactivation and inflammatory responses.
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Affiliation(s)
- Maryam Mehranpour
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Genetics, Faculty of Biological Sciences, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mojtaba Sani
- Department of Educational Neuroscience, Aras International Campus, University of Tabriz, Tabriz, Iran
| | - Amirreza Beirami
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maral Hasanzadeh
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghizadeh
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mobina Banihashemi
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Meysam Hassani Moghaddam
- Department of Anatomical Sciences, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran.
| | - Mobina Fathi
- Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kimia Vakili
- Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shirin Yaghoobpoor
- Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Neda Eskandari
- Department of Anatomical Sciences, Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Mohammad-Amin Abdollahifar
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amir-Hossein Bayat
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abbas Aliaghaei
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad Hossain Heidari
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Gebril HM, Lai T, Fedele DE, Wahba A. Developmental and foliation changes due to dysregulation of adenosine kinase in the cerebellum. Sci Rep 2023; 13:19831. [PMID: 37963945 PMCID: PMC10645999 DOI: 10.1038/s41598-023-47098-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/09/2023] [Indexed: 11/16/2023] Open
Abstract
Adenosine kinase (ADK), the major adenosine-metabolizing enzyme, plays a key role in brain development and disease. In humans, mutations in the Adk gene have been linked to developmental delay, stunted growth, and intellectual disability. To better understand the role of ADK in brain development, it is important to dissect the specific roles of the two isoforms of the enzyme expressed in the cytoplasm (ADK-S) and cell nucleus (ADK-L). We, therefore, studied brain development in Adk-tg transgenic mice, which only express ADK-S in the absence of ADK-L throughout development. In the mutant animals, we found a reduction in the overall brain, body size, and weight during fetal and postnatal development. As a major developmental abnormality, we found a profound change in the foliation pattern of the cerebellum. Strikingly, our results indicated aberrant Purkinje cells arborization at P9 and accelerated cell death at P6 and P9. We found defects in cerebellar cell proliferation and migration using a bromodeoxyuridine (BrdU)-based cell proliferation assay at postnatal day 7. Our data demonstrate that dysregulation of ADK expression during brain development profoundly affects brain growth and differentiation.
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Affiliation(s)
- Hoda M Gebril
- Departement of Biomedical Engineering, School of Engineering, Rutgers University, Piscataway, NJ, 08854, USA.
| | - Tho Lai
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
| | - Denise E Fedele
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
| | - Amir Wahba
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
- Chemistry Department, Faculty of Science, Damietta University, New Damietta City, 34518, Egypt
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Guo M, Wang J, Xiong Z, Wang X, Yang Y, Zhang Y, Tang C, Zhang J, Guan Y, Chen F, Yao K, Teng P, Zhou J, Zhai F, Boison D, Luan G, Li T. Ectopic expression of neuronal adenosine kinase, a biomarker in mesial temporal lobe epilepsy without hippocampal sclerosis. Neuropathol Appl Neurobiol 2023; 49:e12926. [PMID: 37483117 PMCID: PMC11000230 DOI: 10.1111/nan.12926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/25/2023]
Abstract
AIMS Mesial temporal lobe epilepsy without hippocampal sclerosis (no-HS MTLE) refers to those MTLE patients who have neither magnetic resonance imaging (MRI) lesions nor definite pathological evidence of hippocampal sclerosis. They usually have resistance to antiepileptic drugs, difficulties in precise seizure location and poor surgical outcomes. Adenosine is a neuroprotective neuromodulator that acts as a seizure terminator in the brain. The role of adenosine in no-HS MTLE is still unclear. Further research to explore the aetiology and pathogenesis of no-HS MTLE may help to find new therapeutic targets. METHODS In surgically resected hippocampal specimens, we examined the maladaptive changes of the adenosine system of patients with no-HS MTLE. In order to better understand the dysregulation of the adenosine pathway in no-HS MTLE, we developed a rat model based on the induction of focal cortical lesions through a prenatal freeze injury. RESULTS We first examined the adenosine system in no-HS MTLE patients who lack hippocampal neuronal loss and found ectopic expression of the astrocytic adenosine metabolising enzyme adenosine kinase (ADK) in hippocampal pyramidal neurons, as well as downregulation of neuronal A1 receptors (A1 Rs) in the hippocampus. In the no-HS MTLE model rats, the transition of ADK from neuronal expression to an adult pattern of glial expression in the hippocampus was significantly delayed. CONCLUSIONS Ectopic expression of neuronal ADK might be a pathological hallmark of no-HS MTLE. Maladaptive changes in adenosine metabolism might be a novel target for therapeutic intervention in no-HS MTLE.
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Affiliation(s)
- Mengyi Guo
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Jing Wang
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Zhonghua Xiong
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xiongfei Wang
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yujiao Yang
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yifan Zhang
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Chongyang Tang
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Jing Zhang
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yuguang Guan
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Fan Chen
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Kun Yao
- Department of Pathology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Pengfei Teng
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Jian Zhou
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Feng Zhai
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, New Jersey
| | - Guoming Luan
- Department of Neurosurgery, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Tianfu Li
- Department of Brain Institute, Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing Key Laboratory of Epilepsy Research, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Department of Neurology, Center of Epilepsy, Beijing Institute for Brain Disorders, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
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Henning L, Unichenko P, Bedner P, Steinhäuser C, Henneberger C. Overview Article Astrocytes as Initiators of Epilepsy. Neurochem Res 2023; 48:1091-1099. [PMID: 36244037 PMCID: PMC10030460 DOI: 10.1007/s11064-022-03773-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 08/22/2022] [Accepted: 09/27/2022] [Indexed: 10/17/2022]
Abstract
Astrocytes play a dual role in the brain. On the one hand, they are active signaling partners of neurons and can for instance control synaptic transmission and its plasticity. On the other hand, they fulfill various homeostatic functions such as clearance of glutamate and K+ released from neurons. The latter is for instance important for limiting neuronal excitability. Therefore, an impairment or failure of glutamate and K+ clearance will lead to increased neuronal excitability, which could trigger or aggravate brain diseases such as epilepsy, in which neuronal hyperexcitability plays a role. Experimental data indicate that astrocytes could have such a causal role in epilepsy, but the role of astrocytes as initiators of epilepsy and the relevant mechanisms are under debate. In this overview, we will discuss the potential mechanisms with focus on K+ clearance, glutamate uptake and homoeostasis and related mechanisms, and the evidence for their causative role in epilepsy.
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Affiliation(s)
- Lukas Henning
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Petr Unichenko
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127, Bonn, Germany.
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127, Bonn, Germany.
- German Center for Neurodegenerative Diseases (DZNE), 53127, Bonn, Germany.
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7
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Purnell BS, Alves M, Boison D. Astrocyte-neuron circuits in epilepsy. Neurobiol Dis 2023; 179:106058. [PMID: 36868484 DOI: 10.1016/j.nbd.2023.106058] [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: 12/19/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The epilepsies are a diverse spectrum of disease states characterized by spontaneous seizures and associated comorbidities. Neuron-focused perspectives have yielded an array of widely used anti-seizure medications and are able to explain some, but not all, of the imbalance of excitation and inhibition which manifests itself as spontaneous seizures. Furthermore, the rate of pharmacoresistant epilepsy remains high despite the regular approval of novel anti-seizure medications. Gaining a more complete understanding of the processes that turn a healthy brain into an epileptic brain (epileptogenesis) as well as the processes which generate individual seizures (ictogenesis) may necessitate broadening our focus to other cell types. As will be detailed in this review, astrocytes augment neuronal activity at the level of individual neurons in the form of gliotransmission and the tripartite synapse. Under normal conditions, astrocytes are essential to the maintenance of blood-brain barrier integrity and remediation of inflammation and oxidative stress, but in epilepsy these functions are impaired. Epilepsy results in disruptions in the way astrocytes relate to each other by gap junctions which has important implications for ion and water homeostasis. In their activated state, astrocytes contribute to imbalances in neuronal excitability due to their decreased capacity to take up and metabolize glutamate and an increased capacity to metabolize adenosine. Furthermore, due to their increased adenosine metabolism, activated astrocytes may contribute to DNA hypermethylation and other epigenetic changes that underly epileptogenesis. Lastly, we will explore the potential explanatory power of these changes in astrocyte function in detail in the specific context of the comorbid occurrence of epilepsy and Alzheimer's disease and the disruption in sleep-wake regulation associated with both conditions.
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Affiliation(s)
- Benton S Purnell
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America
| | - Mariana Alves
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin D02 YN77, Ireland
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Brain Health Institute, Rutgers University, Piscataway, NJ, United States of America.
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Rajeswarie RT, Aravinda HR, Arivazhagan A, Bevinahalli NN, Rao MB, Mahadevan A. Evaluating the Role of Perilesional Tissue in Pathobiology of Epileptogenesis of Vascular Malformations of the Central Nervous System. J Epilepsy Res 2022; 12:53-61. [PMID: 36685742 PMCID: PMC9830028 DOI: 10.14581/jer.22010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 01/09/2023] Open
Abstract
Background and Purpose Seizures are common presentation of cerebral vascular malformation (CVM). Topography and haemodynamic alterations are proposed as mechanisms for epileptogenesis, but the role of glial/neuronal alterations in perilesional tissue has not received much attention. Identification of the exact pathophysiologic basis could have therapeutic implications. To evaluate whether angioarchitectural factors of CVM or alterations in neuroglial/stroma of the adjacent cortex contribute to seizures. Method The clinical, imaging and histological characteristics of arteriovenous malformation (AVM) and cerebral cavernous malformation (CCM) with and without seizures was evaluated using neuroimaging imaging and digital subtraction angiography parameters and histopathology by morphology and immunohistochemistry. Results Fifty-six cases of CVM were diagnosed over a 2-year study period. Of these, 32 had adequate perilesional tissue for evaluation (AVM, 24; CCM, 8). Seizures at presentation was seen in 12/24 (50%) of AVM and 5/8 (62.5%) CCM. In AVM, hemosiderin deposition and gliosis in parenchyma (p=0.01) had significant association with seizure. Siderotic vessels in the adjacent cortex was exclusively seen only in CCM with seizures (p=0.018). Angioarchitectural features of CVM on imaging and neuronal alterations in adjacent cortex on histology failed to show any statistically significant difference between the two groups (p>0.05). Conclusions We propose that changes in adjacent cortex appear to be epileptogenic rather than the malformation per se. Reactive gliosis and hemosiderin deposits in perilesional tissue in AVM and siderotic vessels in CCM were associated with seizure. This explains the better outcomes following extended lesionectomy that includes epileptogenic perilesional tissues.
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Affiliation(s)
- RT Rajeswarie
- Department of Neuropathology, National Institute of Mental Health & Neurosciences, Bangalore,
India
| | - HR Aravinda
- Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health & Neurosciences, Bangalore,
India
| | - A Arivazhagan
- Department of Neurosurgery, National Institute of Mental Health & Neurosciences, Bangalore,
India
| | - N Nandeesh Bevinahalli
- Department of Neuropathology, National Institute of Mental Health & Neurosciences, Bangalore,
India
| | - Malla Bhaskara Rao
- Department of Neurosurgery, National Institute of Mental Health & Neurosciences, Bangalore,
India
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health & Neurosciences, Bangalore,
India
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Abstract
PURPOSE OF REVIEW To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential strategies to treat seizures. RECENT FINDINGS Recent studies have highlighted the role of functional network systems underlying epileptiform activation in sleep in several epilepsy syndromes, including absence epilepsy, benign focal childhood epilepsy, and epileptic encephalopathy with spike-wave activation in sleep. Sleep disorders are common in epilepsy, and early recognition and treatment can improve seizure frequency and potentially reduce SUDEP risk. Additionally, epilepsy is associated with cyclical patterns, which has led to new treatment approaches including chronotherapy, seizure monitoring devices, and seizure forecasting. Adenosine kinase and orexin receptor antagonists are also promising new potential drug targets that could be used to treat seizures. Sleep and epilepsy have a bidirectional relationship that intersects with many aspects of clinical management. In this article, we identify new areas of research involving future therapeutic opportunities in the field of epilepsy.
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Gimenes C, Motta Pollo ML, Diaz E, Hargreaves EL, Boison D, Covolan L. Deep brain stimulation of the anterior thalamus attenuates PTZ kindling with concomitant reduction of adenosine kinase expression in rats. Brain Stimul 2022; 15:892-901. [PMID: 35690386 DOI: 10.1016/j.brs.2022.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/27/2022] [Accepted: 05/31/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is an emerging therapy to provide seizure control in patients with refractory epilepsy, although its therapeutic mechanisms remain elusive. OBJECTIVE We tested the hypothesis that ANT-DBS might interfere with the kindling process using three experimental groups: PTZ, DBS-ON and DBS-OFF. METHODS 79 male rats were used in two experiments and exposed to chemical kindling with pentylenetetrazole (PTZ, 30 mg/kg i.p.), delivered three times a week for a total of 18 kindling days (KD). These animals were divided into two sets of three groups: PTZ (n = 26), DBS-ON (n = 28) and DBS-OFF (n = 25). ANT-DBS (130 Hz, 90 μs, and 200 μA) was paired with PTZ injections, while DBS-OFF group, although implanted remained unstimulated. After KD 18, the first set of PTZ-treated animals and an additional group of 11 naïve rats were euthanized for brain extraction to study adenosine kinase (ADK) expression. To observe possible long-lasting effects of ANT stimulation, the second set of animals underwent a 1-week treatment and stimulation-free period after KD 18 before a final PTZ challenge. RESULTS ANT-DBS markedly attenuated kindling progression in the DBS-ON group, which developed seizure scores of 2.4 on KD 13, whereas equivalent seizure scores were reached in the DBS-OFF and PTZ groups as early as KD5 and KD6, respectively. The incidence of animals with generalized seizures following 3 consecutive PTZ injections was 94%, 74% and 21% in PTZ, DBS-OFF and DBS-ON groups, respectively. Seizure scores triggered by a PTZ challenge one week after cessation of stimulation revealed lasting suppression of seizure scores in the DBS-ON group (2.7 ± 0.2) compared to scores of 4.5 ± 0.1 for the PTZ group and 4.3 ± 0.1 for the DBS-OFF group (P = 0.0001). While ANT-DBS protected hippocampal cells, the expression of ADK was decreased in the DBS-ON group compared to both PTZ (P < 0.01) and naïve animals (P < 0.01). CONCLUSIONS Our study demonstrates that ANT-DBS interferes with the kindling process and reduced seizure activity was maintained after a stimulation free period of one week. Our findings suggest that ANT-DBS might have additional therapeutic benefits to attenuate seizure progression in epilepsy.
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Affiliation(s)
- Christiane Gimenes
- Department of Physiology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | | | - Eduardo Diaz
- Department of Physiology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Eric L Hargreaves
- Department of Neurosurgery, Jersey Shore University Medical Center, Hackensack Meridian Health Network, Neptune, NJ, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, USA
| | - Luciene Covolan
- Department of Physiology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil; Center for Research, Education and Innovation, Instituto Jô Clemente, Sao Paulo, Brazil.
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11
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Luo HY, Shen HY, Perkins RS, Wang YX. Adenosine Kinase on Deoxyribonucleic Acid Methylation: Adenosine Receptor-Independent Pathway in Cancer Therapy. Front Pharmacol 2022; 13:908882. [PMID: 35721189 PMCID: PMC9200284 DOI: 10.3389/fphar.2022.908882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
Methylation is an important mechanism contributing to cancer pathology. Methylation of tumor suppressor genes and oncogenes has been closely associated with tumor occurrence and development. New insights regarding the potential role of the adenosine receptor-independent pathway in the epigenetic modulation of DNA methylation offer the possibility of new interventional strategies for cancer therapy. Targeting DNA methylation of cancer-related genes is a promising therapeutic strategy; drugs like 5-Aza-2′-deoxycytidine (5-AZA-CdR, decitabine) effectively reverse DNA methylation and cancer cell growth. However, current anti-methylation (or methylation modifiers) are associated with severe side effects; thus, there is an urgent need for safer and more specific inhibitors of DNA methylation (or DNA methylation modifiers). The adenosine signaling pathway is reported to be involved in cancer pathology and participates in the development of tumors by altering DNA methylation. Most recently, an adenosine metabolic clearance enzyme, adenosine kinase (ADK), has been shown to influence methylation on tumor suppressor genes and tumor development and progression. This review article focuses on recent updates on ADK and its two isoforms, and its actions in adenosine receptor-independent pathways, including methylation modification and epigenetic changes in cancer pathology.
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Affiliation(s)
- Hao-Yun Luo
- Chongqing Medical University, Chongqing, China.,Department of Gastrointestinal and Anorectal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing, China
| | - Hai-Ying Shen
- Department of Neuroscience, Legacy Research Institute, Portland, OR, United States.,Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA, United States
| | - R Serene Perkins
- Legacy Tumor Bank, Legacy Research Institute, Portland, OR, United States.,Mid-Columbia Medical Center, The Dalles, OR, United States
| | - Ya-Xu Wang
- Chongqing Medical University, Chongqing, China.,Department of Gastrointestinal and Anorectal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing, China
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12
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Hwang Y, Kim HC, Shin EJ. Effect of rottlerin on astrocyte phenotype polarization after trimethyltin insult in the dentate gyrus of mice. J Neuroinflammation 2022; 19:142. [PMID: 35690821 PMCID: PMC9188234 DOI: 10.1186/s12974-022-02507-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 06/01/2022] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND It has been demonstrated that reactive astrocytes can be polarized into pro-inflammatory A1 phenotype or anti-inflammatory A2 phenotype under neurotoxic and neurodegenerative conditions. Microglia have been suggested to play a critical role in astrocyte phenotype polarization by releasing pro- and anti-inflammatory mediators. In this study, we examined whether trimethyltin (TMT) insult can induce astrocyte polarization in the dentate gyrus of mice, and whether protein kinase Cδ (PKCδ) plays a role in TMT-induced astrocyte phenotype polarization. METHODS Male C57BL/6 N mice received TMT (2.6 mg/kg, i.p.), and temporal changes in the mRNA expression of A1 and A2 phenotype markers were evaluated in the hippocampus. In addition, temporal and spatial changes in the protein expression of C3, S100A10, Iba-1, and p-PKCδ were examined in the dentate gyrus. Rottlerin (5 mg/kg, i.p. × 5 at 12-h intervals) was administered 3-5 days after TMT treatment, and the expression of A1 and A2 transcripts, p-PKCδ, Iba-1, C3, S100A10, and C1q was evaluated 6 days after TMT treatment. RESULTS TMT treatment significantly increased the mRNA expression of A1 and A2 phenotype markers, and the increased expression of A1 markers remained longer than that of A2 markers. The immunoreactivity of the representative A1 phenotype marker, C3 and A2 phenotype marker, S100A10 peaked 6 days after TMT insult in the dentate gyrus. While C3 was expressed evenly throughout the dentate gyrus, S100A10 was highly expressed in the hilus and inner molecular layer. In addition, TMT insult induced microglial p-PKCδ expression. Treatment with rottlerin, a PKCδ inhibitor, decreased Iba-1 and C3 expression, but did not affect S100A10 expression, suggesting that PKCδ inhibition attenuates microglial activation and A1 astrocyte phenotype polarization. Consistently, rottlerin significantly reduced the expression of C1q and tumor necrosis factor-α (TNFα), which has been suggested to be released by activated microglia and induce A1 astrocyte polarization. CONCLUSION We demonstrated the temporal and spatial profiles of astrocyte polarization after TMT insult in the dentate gyrus of mice. Taken together, our results suggest that PKCδ plays a role in inducing A1 astrocyte polarization by promoting microglial activation and consequently increasing the expression of pro-inflammatory mediators after TMT insult.
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Affiliation(s)
- Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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13
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Fábera P, Uttl L, Kubová H, Tsenov G, Mareš P. Adenosine Kinase Isoforms in the Developing Rat Hippocampus after LiCl/Pilocarpine Status Epilepticus. Int J Mol Sci 2022; 23:ijms23052510. [PMID: 35269653 PMCID: PMC8910300 DOI: 10.3390/ijms23052510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 01/27/2023] Open
Abstract
LiCl/pilocarpine status epilepticus (SE) induced in immature rats leads, after a latent period, to hippocampal hyperexcitability. The excitability may be influenced by adenosine, which exhibits anticonvulsant activity. The concentration of adenosine is regulated by adenosine kinase (ADK) present in two isoforms—ADK-L and ADK-S. The main goal of the study is to elucidate the changes in ADK isoform expression after LiCl/pilocarpine SE and whether potential changes, as well as inhibition of ADK by 5-iodotubercidin (5-ITU), may contribute to changes in hippocampal excitability during brain development. LiCl/pilocarpine SE was elicited in 12-day-old rats. Hippocampal excitability in immature rats was studied by the model of hippocampal afterdischarges (ADs), in which we demonstrated the potential inhibitory effect of 5-ITU. ADs demonstrated significantly decreased hippocampal excitability 3 days after SE induction, whereas significant hyperexcitability after 20 days compared to controls was shown. 5-ITU administration showed its inhibitory effect on the ADs in 32-day-old SE rats compared to SE rats without 5-ITU. Moreover, both ADK isoforms were examined in the immature rat hippocampus. The ADK-L isoform demonstrated significantly decreased expression in 12-day-old SE rats compared to the appropriate naïve rats, whereas increased ADK-S isoform expression was revealed. A decreasing ADK-L/-S ratio showed the declining dominance of ADK-L isoform during early brain development. LiCl/pilocarpine SE increased the excitability of the hippocampus 20 days after SE induction. The ADK inhibitor 5-ITU exhibited anticonvulsant activity at the same age. Age-related differences in hippocampal excitability after SE might correspond to the development of ADK isoform levels in the hippocampus.
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Affiliation(s)
- Petr Fábera
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic; (L.U.); (H.K.); (G.T.); (P.M.)
- Department of Neurology, Second Faculty of Medicine, Motol University Hospital, Charles University, 15006 Prague, Czech Republic
- Correspondence: ; Tel.: +42-073-272-8308; Fax: +42-022-443-6875
| | - Libor Uttl
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic; (L.U.); (H.K.); (G.T.); (P.M.)
- National Institute of Mental Health, 25067 Klecany, Czech Republic
| | - Hana Kubová
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic; (L.U.); (H.K.); (G.T.); (P.M.)
| | - Grygoriy Tsenov
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic; (L.U.); (H.K.); (G.T.); (P.M.)
- National Institute of Mental Health, 25067 Klecany, Czech Republic
| | - Pavel Mareš
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic; (L.U.); (H.K.); (G.T.); (P.M.)
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14
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Strogulski NR, Stefani MA, Böhmer AE, Hansel G, Rodolphi MS, Kopczynski A, de Oliveira VG, Stefani ET, Portela JV, Schmidt AP, Oses JP, Smith DH, Portela LV. Cerebrospinal fluid purinomics as a biomarker approach to predict outcome after severe traumatic brain injury. J Neurochem 2022; 161:173-186. [PMID: 35157328 PMCID: PMC9035090 DOI: 10.1111/jnc.15590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/19/2022] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Severe traumatic brain injury (TBI) is associated with high rates of mortality and long-term disability linked to neurochemical abnormalities. Although purine-derivatives play important roles in TBI pathogenesis in preclinical models, little is known about potential changes in purine levels and their implications in human TBI. We assessed cerebrospinal fluid (CSF) levels of purines in severe TBI patients as potential biomarkers that predict mortality and long-term dysfunction. This was a cross-sectional study performed in 17 severe TBI patients (Glasgow Coma Scale < 8) and 51 controls. Two to four hours after admission to ICU, patients were submitted to ventricular drainage and CSF collection for quantification of adenine and guanine purine-derivatives by HPLC. TBI patients survival was followed up to 3 days from admission. A neurofunctional assessment was performed through the modified Rankin Scale (mRS) two years after ICU admission. Purine levels were compared between control and TBI patients, and between surviving and non-surviving patients. Relative to controls, TBI patients presented increased CSF levels of GDP, guanosine, adenosine, inosine, hypoxanthine, and xanthine. Further, GTP, GDP, IMP, and xanthine levels were different between surviving and non-surviving patients. Among the purines, guanosine was associated with improved mRS (p=0.042; r= -0.506). Remarkably, GTP displayed predictive value (AUC=0.841, p=0.024) for discriminating survival vs. non-survival patients up to three days from admission. These results support TBI-specific purine signatures, suggesting GTP as a promising biomarker of mortality, and guanosine as an indicator of long-term functional disability.
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Affiliation(s)
- Nathan R Strogulski
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Marco Antonio Stefani
- Laboratory of Neuroanatomy, Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ana Elisa Böhmer
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gisele Hansel
- Neuroinflammation and Neuroimmunology Laboratory, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
| | - Marcelo S Rodolphi
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Afonso Kopczynski
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Vitória G de Oliveira
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Eduarda T Stefani
- Laboratory of Neuroanatomy, Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Juliana V Portela
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - André P Schmidt
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.,Department of Anesthesia and Perioperative Medicine, Hospital de Clínicas de Porto Alegre (HCPA), UFRGS, Porto Alegre, RS, Brazil. Department of Anesthesia, Santa Casa de Porto Alegre, Universidade Federal de Ciências Médicas de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil. Department of Anesthesia, Hospital Nossa Senhora da Conceição, Porto Alegre, RS, Brazil
| | - Jean Pierre Oses
- Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS, Brazil
| | - Douglas H Smith
- Penn Center for Brain Injury and Repair and Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Luis V Portela
- Laboratory of Neurotrauma e Biomarkers, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
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15
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Shimoda Y, Beppu K, Ikoma Y, Morizawa YM, Zuguchi S, Hino U, Yano R, Sugiura Y, Moritoh S, Fukazawa Y, Suematsu M, Mushiake H, Nakasato N, Iwasaki M, Tanaka KF, Tominaga T, Matsui K. Optogenetic stimulus-triggered acquisition of seizure resistance. Neurobiol Dis 2021; 163:105602. [PMID: 34954320 DOI: 10.1016/j.nbd.2021.105602] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/26/2022] Open
Abstract
Unlike an electrical circuit, the hardware of the brain is susceptible to change. Repeated electrical brain stimulation mimics epileptogenesis. After such "kindling" process, a moderate stimulus would become sufficient in triggering a severe seizure. Here, we report that optogenetic neuronal stimulation can also convert the rat brain to a hyperexcitable state. However, continued stimulation once again converted the brain to a state that was strongly resistant to seizure induction. Histochemical examinations showed that moderate astrocyte activation was coincident with resilience acquisition. Administration of an adenosine A1 receptor antagonist instantly reverted the brain back to a hyperexcitable state, suggesting that hyperexcitability was suppressed by adenosine. Furthermore, an increase in basal adenosine was confirmed using in vivo microdialysis. Daily neuron-to-astrocyte signaling likely prompted a homeostatic increase in the endogenous actions of adenosine. Our data suggest that a certain stimulation paradigm could convert the brain circuit resilient to epilepsy without exogenous drug administration.
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Affiliation(s)
- Yoshiteru Shimoda
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kaoru Beppu
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan
| | - Yosuke M Morizawa
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan
| | - Satoshi Zuguchi
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Utaro Hino
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Ryutaro Yano
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Yuki Sugiura
- Department of Biochemistry & Integrative Medical Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Satoru Moritoh
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yugo Fukazawa
- Division of Cell Biology and Neuroscience, University of Fukui Faculty of Medical Sciences, Fukui 910-1193, Japan
| | - Makoto Suematsu
- Department of Biochemistry & Integrative Medical Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Nobukazu Nakasato
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Ko Matsui
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan.
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16
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Zhang L, Wang Y. Gene therapy in epilepsy. Biomed Pharmacother 2021; 143:112075. [PMID: 34488082 DOI: 10.1016/j.biopha.2021.112075] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 01/15/2023] Open
Abstract
Gene therapy may constitute a promising alternative to conventional pharmacological tools and surgeries for epilepsy. For primary epilepsy, a single variant leading to a significant effect is relatively rare, while other forms are considered complex in inheritances with multiple susceptible mutations and impacts from the environment. Gene therapy in preclinical models of epilepsy has attempted to perform antiepileptogenic, anticonvulsant, or disease-modifying effects during epileptogenesis or after establishing the disease. Creating gene vectors tailored for different situations is the key to expanding gene therapy, and choosing the appropriate therapeutic target remains another fundamental problem. A variety of treatment strategies, from overexpressing inhibitory neuropeptides to modulating the expression of neurotransmitters or ion channels, have been tested in animal models. Additionally, emerging new approaches of optogenetics and chemogenetics, as well as genome-editing tools will further boost the prosperity of gene therapy. This review summarizes the experience obtained to date and discusses the challenges and opportunities in clinical translations.
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Affiliation(s)
- Lu Zhang
- Department of Neurology at Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yuping Wang
- Beijing Key Laboratory of Neuromodulation, Capital Medical University, Beijing, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
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17
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Bruxel EM, do Canto AM, Bruno DCF, Geraldis JC, Lopes-Cendes I. Multi-omic strategies applied to the study of pharmacoresistance in mesial temporal lobe epilepsy. Epilepsia Open 2021; 7 Suppl 1:S94-S120. [PMID: 34486831 PMCID: PMC9340306 DOI: 10.1002/epi4.12536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 12/19/2022] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adults, and hippocampal sclerosis (HS) is a frequent histopathological feature in patients with MTLE. Pharmacoresistance is present in at least one-third of patients with MTLE with HS (MTLE+HS). Several hypotheses have been proposed to explain the mechanisms of pharmacoresistance in epilepsy, including the effect of genetic and molecular factors. In recent years, the increased knowledge generated by high-throughput omic technologies has significantly improved the power of molecular genetic studies to discover new mechanisms leading to disease and response to treatment. In this review, we present and discuss the contribution of different omic modalities to understand the basic mechanisms determining pharmacoresistance in patients with MTLE+HS. We provide an overview and a critical discussion of the findings, limitations, new approaches, and future directions of these studies to improve the understanding of pharmacoresistance in MTLE+HS. However, it is important to point out that, as with other complex traits, pharmacoresistance to anti-seizure medications is likely a multifactorial condition in which gene-gene and gene-environment interactions play an important role. Thus, studies using multidimensional approaches are more likely to unravel these intricate biological processes.
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Affiliation(s)
- Estela M Bruxel
- Departments of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
| | - Amanda M do Canto
- Departments of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
| | - Danielle C F Bruno
- Departments of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
| | - Jaqueline C Geraldis
- Departments of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
| | - Iscia Lopes-Cendes
- Departments of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, Brazil
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18
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Reactive astrocytes contribute to epileptogenesis in patients with cavernous angioma. Epilepsy Res 2021; 176:106732. [PMID: 34332257 DOI: 10.1016/j.eplepsyres.2021.106732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/20/2021] [Accepted: 07/23/2021] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Patients with cavernous angioma (CA) often suffer from severe epilepsy, and surgical resection is often performed to attenuate these epileptic seizures. Several studies have suggested that surgical removal of the surrounding hemosiderin-pigmented tissues adjacent to CA achieves better seizure control than restricted lesionectomy. Pathological examination of the resected foci reveals not only hemosiderin pigmentation but also various degrees of inflammatory change, such as hemosiderin-laden macrophages, gliosis and fibrosis. However, there is some controversy regarding the epileptogenic potential of these regions due to the uncertain nature of the mechanisms contributing to these histopathological changes. METHODS To investigate the correlations between neuron hyperexcitability and evident pathological changes, we performed ex vivo flavoprotein fluorescence imaging using surgically resected epileptogenic foci surrounding CA. The mirror surfaces of the tissues used for the physiological experiment were also subjected to morphological examination. RESULTS Hemosiderin-laden macrophages and many gemistocytic astrocytes were observed in the area adjacent to CA, where horizontal spreading excitations were detected significantly more frequently. Outside these areas, we found fine granular iron deposits and only a few fibrillary astrocytes, and weakly propagating excitations were detected. Furthermore, areas of enhanced activation were more clearly correlated with the glial proliferation index than with iron deposition. CONCLUSION These results suggest that the epileptogenesis in patients with CA may be based on a biological process, such as alteration of glial function, rather than direct chemical reactions involving iron deposition.
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19
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Koh HY, Jang J, Ju SH, Kim R, Cho GB, Kim DS, Sohn JW, Paik SB, Lee JH. Non-Cell Autonomous Epileptogenesis in Focal Cortical Dysplasia. Ann Neurol 2021; 90:285-299. [PMID: 34180075 DOI: 10.1002/ana.26149] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Low-level somatic mosaicism in the brain has been shown to be a major genetic cause of intractable focal epilepsy. However, how a relatively few mutation-carrying neurons are able to induce epileptogenesis at the local network level remains poorly understood. METHODS To probe the origin of epileptogenesis, we measured the excitability of neurons with MTOR mutation and nearby nonmutated neurons recorded by whole-cell patch-clamp and array-based electrodes comparing the topographic distribution of mutation. Computational simulation is used to understand neural network-level changes based on electrophysiological properties. To examine the underlying mechanism, we measured inhibitory and excitatory synaptic inputs in mutated neurons and nearby neurons by electrophysiological and histological methods using the mouse model and postoperative human brain tissue for cortical dysplasia. To explain non-cell-autonomous hyperexcitability, an inhibitor of adenosine kinase was injected into mice to enhance adenosine signaling and to mitigate hyperactivity of nearby nonmutated neurons. RESULTS We generated mice with a low-level somatic mutation in MTOR presenting spontaneous seizures. The seizure-triggering hyperexcitability originated from nonmutated neurons near mutation-carrying neurons, which proved to be less excitable than nonmutated neurons. Interestingly, the net balance between excitatory and inhibitory synaptic inputs onto mutated neurons remained unchanged. Additionally, we found that inhibition of adenosine kinase, which affects adenosine metabolism and neuronal excitability, reduced the hyperexcitability of nonmutated neurons. INTERPRETATION This study shows that neurons carrying somatic mutations in MTOR lead to focal epileptogenesis via non-cell-autonomous hyperexcitability of nearby nonmutated neurons. ANN NEUROL 2021;90:285-299.
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Affiliation(s)
- Hyun Yong Koh
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jaeson Jang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Sang Hyeon Ju
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Ryunhee Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Gyu-Bon Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Dong Seok Kim
- Department of Neurosurgery, Pediatric Epilepsy Clinics, Brain Korea 21 Project for Medical Science, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Se-Bum Paik
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.,Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.,SoVarGen, Daejeon, Republic of Korea
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20
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Peterson AR, Garcia TA, Cullion K, Tiwari-Woodruff SK, Pedapati EV, Binder DK. Targeted overexpression of glutamate transporter-1 reduces seizures and attenuates pathological changes in a mouse model of epilepsy. Neurobiol Dis 2021; 157:105443. [PMID: 34246771 DOI: 10.1016/j.nbd.2021.105443] [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: 05/07/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 01/06/2023] Open
Abstract
Astrocytic glutamate transporters are crucial for glutamate homeostasis in the brain, and dysregulation of these transporters can contribute to the development of epilepsy. Glutamate transporter-1 (GLT-1) is responsible for the majority of glutamate uptake in the dorsal forebrain and has been shown to be reduced at epileptic foci in patients and preclinical models of temporal lobe epilepsy (TLE). Current antiepileptic drugs (AEDs) work primarily by targeting neurons directly through suppression of excitatory neurotransmission or enhancement of inhibitory neurotransmission, which can lead to both behavioral and psychiatric side effects. This study investigates the therapeutic capacity of astrocyte-specific AAV-mediated GLT-1 expression in the intrahippocampal kainic acid (IHKA) model of TLE. In this study, we used Western blot analysis, immunohistochemistry, and long-term-video EEG monitoring to demonstrate that cell-type-specific upregulation of GLT-1 in astrocytes is neuroprotective at early time points during epileptogenesis, reduces seizure frequency and total time spent in seizures, and eliminates large behavioral seizures in the IHKA model of epilepsy. Our findings suggest that targeting glutamate uptake is a promising therapeutic strategy for the treatment of epilepsy.
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Affiliation(s)
- Allison R Peterson
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, CA, USA
| | - Terese A Garcia
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, CA, USA
| | - Kyle Cullion
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, CA, USA
| | - Ernest V Pedapati
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Devin K Binder
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, CA, USA.
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21
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Jalloul D, Hajjar H, Asdikian R, Maawie M, Nasrallah L, Medlej Y, Darwich M, Karnib N, Lawand N, Abdel Rassoul R, Wang KKW, Kobeissy F, Darwish H, Obeid M. Potentiating Hemorrhage in a Periadolescent Rat Model of Closed-Head Traumatic Brain Injury Worsens Hyperexcitability but Not Behavioral Deficits. Int J Mol Sci 2021; 22:6456. [PMID: 34208666 PMCID: PMC8234967 DOI: 10.3390/ijms22126456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/07/2021] [Accepted: 06/11/2021] [Indexed: 12/29/2022] Open
Abstract
Post-traumatic epilepsy (PTE) and neurocognitive deficits are devastating sequelae of head injuries that are common in adolescents. Investigating desperately needed treatments is hindered by the difficulties in inducing PTE in rodents and the lack of established immature rat models of pediatric PTE. Hemorrhage is a significant risk factor for PTE, but compared to humans, rats are less prone to bleeding because of their rapid blood coagulation system. In this study, we promoted bleeding in the controlled cortical impact (CCI) closed-head injury model with a 20 min pre-impact 600 IU/kg intraperitoneal heparin injection in postnatal day 35 (P35) periadolescent rats, given the preponderance of such injuries in this age group. Temporo-parietal CCI was performed post-heparin (HTBI group) or post-saline (TBI group). Controls were subjected to sham procedures following heparin or saline administration. Continuous long-term EEG monitoring was performed for 3 months post-CCI. Sensorimotor testing, the Morris water maze, and a modified active avoidance test were conducted between P80 and P100. Glial fibrillary acidic protein (GFAP) levels and neuronal damage were also assessed. Compared to TBI rats, HTBI rats had persistently higher EEG spiking and increased hippocampal GFAP levels (p < 0.05). No sensorimotor deficits were detected in any group. Compared to controls, both HTBI and TBI groups had a long-term hippocampal neuronal loss (p < 0.05), as well as contextual and visuospatial learning deficits (p < 0.05). The hippocampal astrogliosis and EEG spiking detected in all rats subjected to our hemorrhage-promoting procedure suggest the emergence of hyperexcitable networks and pave the way to a periadolescent PTE rat model.
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Affiliation(s)
- Dounya Jalloul
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
| | - Helene Hajjar
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
| | - Rita Asdikian
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
| | - Mariam Maawie
- Neuroscience Research Center, Faculty of Medical Sciences, Lebanese University, Hadath P.O. Box 6573/14, Lebanon; (M.M.); (R.A.R.)
| | - Leila Nasrallah
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut 1107 2020, Lebanon;
| | - Yasser Medlej
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
| | - Mouhamad Darwich
- Division of Child Neurology, Department of Pediatrics and Adolescent Medicine, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon;
| | - Nabil Karnib
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
| | - Nada Lawand
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
- Department of Neurology, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon
| | - Ronza Abdel Rassoul
- Neuroscience Research Center, Faculty of Medical Sciences, Lebanese University, Hadath P.O. Box 6573/14, Lebanon; (M.M.); (R.A.R.)
| | - Kevin K. W. Wang
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL 32608, USA;
- Program for Neurotrauma, Neuroproteomics & Biomarkers Research, Departments of Emergency Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Firas Kobeissy
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut 1107 2020, Lebanon;
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL 32608, USA;
- Program for Neurotrauma, Neuroproteomics & Biomarkers Research, Departments of Emergency Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Hala Darwish
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
- Rafic Hariri School of Nursing, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Makram Obeid
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut 1107 2020, Lebanon; (D.J.); (H.H.); (R.A.); (Y.M.); (N.K.); (N.L.)
- Division of Child Neurology, Department of Pediatrics and Adolescent Medicine, American University of Beirut Medical Center, Beirut 1107 2020, Lebanon;
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22
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Beamer E, Kuchukulla M, Boison D, Engel T. ATP and adenosine-Two players in the control of seizures and epilepsy development. Prog Neurobiol 2021; 204:102105. [PMID: 34144123 DOI: 10.1016/j.pneurobio.2021.102105] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/07/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
Despite continuous advances in understanding the underlying pathogenesis of hyperexcitable networks and lowered seizure thresholds, the treatment of epilepsy remains a clinical challenge. Over one third of patients remain resistant to current pharmacological interventions. Moreover, even when effective in suppressing seizures, current medications are merely symptomatic without significantly altering the course of the disease. Much effort is therefore invested in identifying new treatments with novel mechanisms of action, effective in drug-refractory epilepsy patients, and with the potential to modify disease progression. Compelling evidence has demonstrated that the purines, ATP and adenosine, are key mediators of the epileptogenic process. Extracellular ATP concentrations increase dramatically under pathological conditions, where it functions as a ligand at a host of purinergic receptors. ATP, however, also forms a substrate pool for the production of adenosine, via the action of an array of extracellular ATP degrading enzymes. ATP and adenosine have assumed largely opposite roles in coupling neuronal excitability to energy homeostasis in the brain. This review integrates and critically discusses novel findings regarding how ATP and adenosine control seizures and the development of epilepsy. This includes purine receptor P1 and P2-dependent mechanisms, release and reuptake mechanisms, extracellular and intracellular purine metabolism, and emerging receptor-independent effects of purines. Finally, possible purine-based therapeutic strategies for seizure suppression and disease modification are discussed.
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Affiliation(s)
- Edward Beamer
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; Centre for Bioscience, Manchester Metropolitan University, John Dalton Building, All Saints Campus, Manchester M15 6BH, UK
| | - Manvitha Kuchukulla
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, NJ 08854, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, NJ 08854, USA.
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland.
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23
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Murugan M, Fedele D, Millner D, Alharfoush E, Vegunta G, Boison D. Adenosine kinase: An epigenetic modulator in development and disease. Neurochem Int 2021; 147:105054. [PMID: 33961946 DOI: 10.1016/j.neuint.2021.105054] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 02/06/2023]
Abstract
Adenosine kinase (ADK) is the key regulator of adenosine and catalyzes the metabolism of adenosine to 5'-adenosine monophosphate. The enzyme exists in two isoforms: a long isoform (ADK-long, ADK-L) and a short isoform (ADK-short, ADK-S). The two isoforms are developmentally regulated and are differentially expressed in distinct subcellular compartments with ADK-L localized in the nucleus and ADK-S localized in the cytoplasm. The nuclear localization of ADK-L and its biochemical link to the transmethylation pathway suggest a specific role for gene regulation via epigenetic mechanisms. Recent evidence reveals an adenosine receptor-independent role of ADK in determining the global methylation status of DNA and thereby contributing to epigenomic regulation. Here we summarize recent progress in understanding the biochemical interactions between adenosine metabolism by ADK-L and epigenetic modifications linked to transmethylation reactions. This review will provide a comprehensive overview of ADK-associated changes in DNA methylation in developmental, as well as in pathological conditions including brain injury, epilepsy, vascular diseases, cancer, and diabetes. Challenges in investigating the epigenetic role of ADK for therapeutic gains are briefly discussed.
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Affiliation(s)
- Madhuvika Murugan
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Denise Fedele
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - David Millner
- Department of Neurosurgery, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA
| | - Enmar Alharfoush
- Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ 08901, USA
| | - Geetasravya Vegunta
- Department of Biology, Albert Dorman Honors College, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA; Department of Neurosurgery, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA; Brain Health Institute, Rutgers University, Piscataway, NJ 08854, USA.
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24
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Jagannath A, Varga N, Dallmann R, Rando G, Gosselin P, Ebrahimjee F, Taylor L, Mosneagu D, Stefaniak J, Walsh S, Palumaa T, Di Pretoro S, Sanghani H, Wakaf Z, Churchill GC, Galione A, Peirson SN, Boison D, Brown SA, Foster RG, Vasudevan SR. Adenosine integrates light and sleep signalling for the regulation of circadian timing in mice. Nat Commun 2021; 12:2113. [PMID: 33837202 PMCID: PMC8035342 DOI: 10.1038/s41467-021-22179-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 02/18/2021] [Indexed: 01/01/2023] Open
Abstract
The accumulation of adenosine is strongly correlated with the need for sleep and the detection of sleep pressure is antagonised by caffeine. Caffeine also affects the circadian timing system directly and independently of sleep physiology, but how caffeine mediates these effects upon the circadian clock is unclear. Here we identify an adenosine-based regulatory mechanism that allows sleep and circadian processes to interact for the optimisation of sleep/wake timing in mice. Adenosine encodes sleep history and this signal modulates circadian entrainment by light. Pharmacological and genetic approaches demonstrate that adenosine acts upon the circadian clockwork via adenosine A1/A2A receptor signalling through the activation of the Ca2+ -ERK-AP-1 and CREB/CRTC1-CRE pathways to regulate the clock genes Per1 and Per2. We show that these signalling pathways converge upon and inhibit the same pathways activated by light. Thus, circadian entrainment by light is systematically modulated on a daily basis by sleep history. These findings contribute to our understanding of how adenosine integrates signalling from both light and sleep to regulate circadian timing in mice.
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Affiliation(s)
- Aarti Jagannath
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK.
| | - Norbert Varga
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Robert Dallmann
- Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Gianpaolo Rando
- Department of Molecular Biology, University of Geneva, Geneva 4, Switzerland
| | - Pauline Gosselin
- Department of Molecular Biology, University of Geneva, Geneva 4, Switzerland
| | - Farid Ebrahimjee
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lewis Taylor
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Dragos Mosneagu
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Jakub Stefaniak
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Steven Walsh
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Teele Palumaa
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Simona Di Pretoro
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Harshmeena Sanghani
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Zeinab Wakaf
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Grant C Churchill
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Antony Galione
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA
| | - Steven A Brown
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, OMPI-G, Oxford, UK.
| | - Sridhar R Vasudevan
- Sleep and Circadian Neuroscience Institute (SCNi), Department of Pharmacology, University of Oxford, Oxford, UK.
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25
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Lopes CR, Lourenço VS, Tomé ÂR, Cunha RA, Canas PM. Use of knockout mice to explore CNS effects of adenosine. Biochem Pharmacol 2020; 187:114367. [PMID: 33333075 DOI: 10.1016/j.bcp.2020.114367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022]
Abstract
The initial exploration using pharmacological tools of the role of adenosine receptors in the brain, concluded that adenosine released as such acted on A1R to inhibit excitability and glutamate release from principal neurons throughout the brain and that adenosine A2A receptors (A2AR) were striatal-'specific' receptors controlling dopamine D2R. This indicted A1R as potential controllers of neurodegeneration and A2AR of psychiatric conditions. Global knockout of these two receptors questioned the key role of A1R and instead identified extra-striatal A2AR as robust controllers of neurodegeneration. Furthermore, transgenic lines with altered metabolic sources of adenosine revealed a coupling of ATP-derived adenosine to activate A2AR and a role of A1R as a hurdle to initiate neurodegeneration. Additionally, cell-selective knockout of A2AR unveiled the different roles of A2AR in different cell types (neurons/astrocytes) in different portions of the striatal circuits (dorsal versus lateral) and in different brain areas (hippocampus/striatum). Finally, a new transgenic mouse line with deletion of all adenosine receptors seems to indicate a major allostatic rather than homeostatic role of adenosine and may allow isolating P2R-mediated responses to unravel their role in the brain, a goal close to heart of Geoffrey Burnstock, to whom we affectionately dedicate this review.
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Affiliation(s)
- Cátia R Lopes
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Vanessa S Lourenço
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Ângelo R Tomé
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal; Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal; Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal.
| | - Paula M Canas
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
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26
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Menéndez Méndez A, Smith J, Engel T. Neonatal Seizures and Purinergic Signalling. Int J Mol Sci 2020; 21:ijms21217832. [PMID: 33105750 PMCID: PMC7660091 DOI: 10.3390/ijms21217832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023] Open
Abstract
Neonatal seizures are one of the most common comorbidities of neonatal encephalopathy, with seizures aggravating acute injury and clinical outcomes. Current treatment can control early life seizures; however, a high level of pharmacoresistance remains among infants, with increasing evidence suggesting current anti-seizure medication potentiating brain damage. This emphasises the need to develop safer therapeutic strategies with a different mechanism of action. The purinergic system, characterised by the use of adenosine triphosphate and its metabolites as signalling molecules, consists of the membrane-bound P1 and P2 purinoreceptors and proteins to modulate extracellular purine nucleotides and nucleoside levels. Targeting this system is proving successful at treating many disorders and diseases of the central nervous system, including epilepsy. Mounting evidence demonstrates that drugs targeting the purinergic system provide both convulsive and anticonvulsive effects. With components of the purinergic signalling system being widely expressed during brain development, emerging evidence suggests that purinergic signalling contributes to neonatal seizures. In this review, we first provide an overview on neonatal seizure pathology and purinergic signalling during brain development. We then describe in detail recent evidence demonstrating a role for purinergic signalling during neonatal seizures and discuss possible purine-based avenues for seizure suppression in neonates.
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Affiliation(s)
- Aida Menéndez Méndez
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
| | - Jonathon Smith
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Tobias Engel
- Department of Physiology and Medical Physics, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; (A.M.M.); (J.S.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
- Correspondence: ; Tel.: +35-314-025-199
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27
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P2Y1 receptor inhibition rescues impaired synaptic plasticity and astroglial Ca 2+-dependent activity in the epileptic hippocampus. Neurobiol Dis 2020; 146:105132. [PMID: 33049315 DOI: 10.1016/j.nbd.2020.105132] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/15/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is characterized by a progressive predisposition to suffer seizures due to neuronal hyperexcitability, and one of its most common co-morbidities is cognitive decline. In animal models of chronic epilepsy, such as kindling, electrically induced seizures impair long-term potentiation (LTP), deteriorating learning and memory performance. Astrocytes are known to actively modulate synaptic plasticity and neuronal excitability through Ca2+-dependent gliotransmitter release. It is unclear, however, if astroglial Ca2+ signaling could contribute to the development of synaptic plasticity alterations in the epileptic hippocampus. By employing electrophysiological tools and Ca2+ imaging, we found that glutamatergic CA3-CA1 synapses from kindled rats exhibit an impairment in theta burst (TBS) and high frequency stimulation (HFS)-induced LTP, which is accompanied by an increased probability of neurotransmitter release (Pr) and an abnormal pattern of astroglial Ca2+-dependent transients. Both the impairment in LTP and the Pr were reversed by inhibiting purinergic P2Y1 receptors (P2Y1R) with the specific antagonist MRS2179, which also restored the spontaneous and TBS-induced pattern of astroglial Ca2+-dependent signals. Two consecutive, spaced TBS protocols also failed to induce LTP in the kindled group, however, this impairment was reversed and a strong LTP was induced when the second TBS was applied in the presence of MRS2179, suggesting that the mechanisms underlying the alterations in TBS-induced LTP are likely associated with an aberrant modulation of the induction threshold for LTP. Altogether, these results indicate that P2Y1R inhibition rescues both the pattern of astroglial Ca2+-activity and the plastic properties of CA3-CA1 synapses in the epileptic hippocampus, suggesting that astrocytes might take part in the mechanisms that deteriorate synaptic plasticity and thus cause cognitive decline in epileptic patients.
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28
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Abstract
It is well known that the neuromodulator adenosine, acting through the adenosine A1 receptor subtype, can limit or stop seizures. In 2008, adenosine was proposed as a key component of the anticonvulsant mechanism of the ketogenic diet (KD), a very low carbohydrate diet that can be highly effective in drug-refractory epilepsy. In this study, we review the accumulated data on the intersection among adenosine, ketosis, and anticonvulsant/antiepileptogenic effects. In several rodent models of epilepsy and seizures, antiseizure effects of ketogenic treatments (the KD itself, exogenous ketone bodies, medium-chain triglycerides or fatty acids) are reversed by administration of an adenosine A1 receptor antagonist. In addition, KD treatment elevates extracellular adenosine and tissue adenosine content in brain. Efforts to maintain or mimic a ketogenic milieu in brain slices reveal a state of reduced excitability produced by pre- and postsynaptic adenosine A1 receptor-based effects. Long-lasting seizure reduction may be due to adenosine-based epigenetic effects. In conclusion, there is accumulating evidence for an adenosinergic anticonvulsant action in the ketogenic state. In some cases, the main trigger is mildly but consistently lowered glucose in the brain. More research is needed to investigate the importance of adenosine in the antiepileptogenic and neuroprotective effects of these treatments. Future research may begin to investigate alternative adenosine-promoting strategies to enhance the KD or to find use as treatments themselves.
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Affiliation(s)
- David N Ruskin
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, Connecticut, USA
| | - Masahito Kawamura
- Department of Pharmacology, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Susan A Masino
- Department of Psychology, Neuroscience Program, Trinity College, Hartford, Connecticut, USA
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29
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Peterson AR, Binder DK. Astrocyte Glutamate Uptake and Signaling as Novel Targets for Antiepileptogenic Therapy. Front Neurol 2020; 11:1006. [PMID: 33013665 PMCID: PMC7505989 DOI: 10.3389/fneur.2020.01006] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/30/2020] [Indexed: 12/14/2022] Open
Abstract
Astrocytes regulate and respond to extracellular glutamate levels in the central nervous system (CNS) via the Na+-dependent glutamate transporters glutamate transporter-1 (GLT-1) and glutamate aspartate transporter (GLAST) and the metabotropic glutamate receptors (mGluR) 3 and mGluR5. Both impaired astrocytic glutamate clearance and changes in metabotropic glutamate signaling could contribute to the development of epilepsy. Dysregulation of astrocytic glutamate transporters, GLT-1 and GLAST, is a common finding across patients and preclinical seizure models. Astrocytic metabotropic glutamate receptors, particularly mGluR5, have been shown to be dysregulated in both humans and animal models of temporal lobe epilepsy (TLE). In this review, we synthesize the available evidence regarding astrocytic glutamate homeostasis and astrocytic mGluRs in the development of epilepsy. Modulation of astrocyte glutamate uptake and/or mGluR activation could lead to novel glial therapeutics for epilepsy.
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Affiliation(s)
- Allison R Peterson
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Devin K Binder
- Division of Biomedical Sciences, Center for Glial-Neuronal Interactions, School of Medicine, University of California, Riverside, Riverside, CA, United States
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30
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Kim JK, Cho J, Kim SH, Kang HC, Kim DS, Kim VN, Lee JH. Brain somatic mutations in MTOR reveal translational dysregulations underlying intractable focal epilepsy. J Clin Invest 2020; 129:4207-4223. [PMID: 31483294 DOI: 10.1172/jci127032] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 07/03/2019] [Indexed: 12/15/2022] Open
Abstract
Brain somatic mutations confer genomic diversity in the human brain and cause neurodevelopmental disorders. Recently, brain somatic activating mutations in MTOR have been identified as a major etiology of intractable epilepsy in patients with cortical malformations. However, the molecular genetic mechanism of how brain somatic mutations in MTOR cause intractable epilepsy has remained elusive. In this study, translational profiling of intractable epilepsy mouse models with brain somatic mutations and genome-edited cells revealed a novel translational dysregulation mechanism and mTOR activation-sensitive targets mediated by human MTOR mutations that lead to intractable epilepsy with cortical malformation. These mTOR targets were found to be regulated by novel mTOR-responsive 5'-UTR motifs, distinct from known mTOR inhibition-sensitive targets regulated by 5' terminal oligopyrimidine motifs. Novel mTOR target genes were validated in patient brain tissues, and the mTOR downstream effector eIF4E was identified as a new therapeutic target in intractable epilepsy via pharmacological or genetic inhibition. We show that metformin, an FDA-approved eIF4E inhibitor, suppresses intractable epilepsy. Altogether, the present study describes translational dysregulation resulting from brain somatic mutations in MTOR, as well as the pathogenesis and potential therapeutic targets of intractable epilepsy.
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Affiliation(s)
- Jang Keun Kim
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Jun Cho
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea.,Center for RNA Research, Institute for Basic Science, Seoul, Republic of Korea
| | - Se Hoon Kim
- Department of Pathology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dong-Seok Kim
- Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.,Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - V Narry Kim
- Center for RNA Research, Institute for Basic Science, Seoul, Republic of Korea.,Department of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Jeong Ho Lee
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.,Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
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31
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Boison D, Rho JM. Epigenetics and epilepsy prevention: The therapeutic potential of adenosine and metabolic therapies. Neuropharmacology 2020; 167:107741. [PMID: 31419398 PMCID: PMC7220211 DOI: 10.1016/j.neuropharm.2019.107741] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/08/2019] [Accepted: 08/13/2019] [Indexed: 12/20/2022]
Abstract
Prevention of epilepsy and its progression remains the most urgent need for epilepsy research and therapy development. Novel conceptual advances are required to meaningfully address this fundamental challenge. Maladaptive epigenetic changes, which include methylation of DNA and acetylation of histones - among other mechanisms, are now well recognized to play a functional role in the development of epilepsy and its progression. The methylation hypothesis of epileptogenesis suggests that changes in DNA methylation are implicated in the progression of the disease. In this context, global DNA hypermethylation is particularly associated with chronic epilepsy. Likewise, acetylation changes of histones have been linked to epilepsy development. Clinical as well as experimental evidence demonstrate that epilepsy and its progression can be prevented by metabolic and biochemical manipulations that target previously unrecognized epigenetic functions contributing to epilepsy development and maintenance of the epileptic state. This review will discuss epigenetic mechanisms implicated in epilepsy development as well as metabolic and biochemical interactions thought to drive epileptogenesis. Therefore, metabolic and biochemical mechanisms are identified as novel targets for epilepsy prevention. We will specifically discuss adenosine biochemistry as a novel therapeutic strategy to reconstruct the DNA methylome as antiepileptogenic strategy as well as metabolic mediators, such as beta-hydroxybutyrate, which affect histone acetylation. Finally, metabolic dietary interventions (such as the ketogenic diet) which have the unique potential to prevent epileptogenesis through recently identified epigenetic mechanisms will be reviewed. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Detlev Boison
- Dept. of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA.
| | - Jong M Rho
- Depts. of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, CA, 92117, USA
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32
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Scemes E, Velíšek L, Velíšková J. Astrocyte and Neuronal Pannexin1 Contribute Distinctly to Seizures. ASN Neuro 2020; 11:1759091419833502. [PMID: 30862176 PMCID: PMC6415468 DOI: 10.1177/1759091419833502] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
ATP- and adenosine-mediated signaling are prominent types of glia–glia and glia–neuron interaction, with an imbalance of ATP/adenosine ratio leading to altered states of excitability, as seen in epileptic seizures. Pannexin1 (Panx1), a member of the gap junction family, is an ATP release channel that is expressed in astrocytes and neurons. Previous studies provided evidence supporting a role for purinergic-mediated signaling via Panx1 channels in seizures; using mice with global deletion of Panx1, it was shown that these channels contribute in maintenance of seizures by releasing ATP. However, nothing is known about the extent to which astrocyte and neuronal Panx1 might differently contribute to seizures. We here show that targeted deletion of Panx1 in astrocytes or neurons has opposing effects on acute seizures induced by kainic acid. The absence of Panx1 in astrocytes potentiates while the absence of Panx1 in neurons attenuates seizure manifestation. Immunohistochemical analysis performed in brains of these mice, revealed that adenosine kinase (ADK), an enzyme that regulates extracellular levels of adenosine, was increased only in seized GFAP-Cre:Panx1f/f mice. Pretreating mice with the ADK inhibitor, idotubercidin, improved seizure outcome and prevented the increase in ADK immunoreactivity. Together, these data suggest that the worsening of seizures seen in mice lacking astrocyte Panx1 is likely related to low levels of extracellular adenosine due to the increased ADK levels in astrocytes. Our study not only reveals an unexpected link between Panx1 channels and ADK but also highlights the important role played by astrocyte Panx1 channels in controlling neuronal activity.
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Affiliation(s)
- Eliana Scemes
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Libor Velíšek
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.,2 Departments of Neurology and Pediatrics, New York Medical College, Valhalla, NY, USA
| | - Jana Velíšková
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA.,3 Departments of Obstetrics & Gynecology and Neurology, New York Medical College, Valhalla, NY, USA
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33
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Riquelme J, Wellmann M, Sotomayor-Zárate R, Bonansco C. Gliotransmission: A Novel Target for the Development of Antiseizure Drugs. Neuroscientist 2020; 26:293-309. [PMID: 31976817 DOI: 10.1177/1073858420901474] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
For more than a century, epilepsy has remained an incapacitating neurological disorder with a high incidence worldwide. Mesial temporal lobe epilepsy (TLE) is a common type of epilepsy without an effective pharmacological treatment. An increase in excitability and hypersynchrony of electrical neuronal activity during development are typically associated with an excitatory/inhibitory imbalance in the neuronal network. Astrocytes release gliotransmitters, which can regulate neuronal excitability and synaptic transmission; therefore, the classical neurocentric vision of the cellular basis of epileptogenesis has begun to change. Growing evidence suggests that the key contribution of astrocyte-to-neuron signaling in the mechanisms underlies the initiation, propagation, and recurrence of seizure activity. The aim of this review was to summarize current evidence obtained from experimental models that suggest how alterations in astroglial modulation of synaptic transmission and neuronal activity contribute to the development of this brain disease. In this article, we will summarize the main pharmacological, Ca2+-imaging, and electrophysiological findings in the gliotransmitter-mediated modulation of neuronal activity and their possible regulation as a novel cellular target for the development of pharmacological strategies for treating refractory epilepsies.
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Affiliation(s)
- Julio Riquelme
- Escuela de Medicina, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Servicio de Neurología, Hospital Carlos Van Buren, Valparaíso, Chile
| | - Mario Wellmann
- Escuela de Fonoaudiología, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Christian Bonansco
- Centro de Neurobiología y Fisiología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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34
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Li RJ, Liu Y, Liu HQ, Li J. Ketogenic diets and protective mechanisms in epilepsy, metabolic disorders, cancer, neuronal loss, and muscle and nerve degeneration. J Food Biochem 2020; 44:e13140. [PMID: 31943235 DOI: 10.1111/jfbc.13140] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022]
Abstract
Ketogenic diet (KD), the "High-fat, low-carbohydrate, adequate-protein" diet strategy, replacing glucose with ketone bodies, is effective against several diseases, from intractable epileptic seizures, metabolic disorders, tumors, autosomal dominant polycystic kidney disease, and neurodegeneration to skeletal muscle atrophy and peripheral neuropathy. Key mechanisms include augmented mitochondrial efficiency, reduced oxidative stress, and regulated phospho-AMP-activated protein kinase, gamma-aminobutyric acid-glutamate, Na+/ K+ pump, leptin and adiponectin levels, ghrelin levels, lipogenesis, ketogenesis, lipolysis, and gluconeogenesis. In cancer cells, KD targets glucose metabolism, suppresses insulin-like growth factor-1 and PI3K/AKT/mTOR pathways, and reduces cancer cachexia and muscle waste and fatigue. An associated increased skeletal proliferator-activated receptor-γ coactivator-1α activity alters systemic ketone body homeostasis, contributing toward attenuated diabetic hyperketonemia. Antioxidative and anti-inflammatory properties enable KD enhance endurance and sports performances while preventing exercise-induced muscle and organ debility. KD reduces metabolic syndromes-associated allodynia and promotes peripheral axonal and sensory regeneration. This review enlightens effects of KD on various disease conditions. PRACTICAL APPLICATIONS: It is increasingly being realized that diet plays a very important role in our fight against several diseases. This can range from neurological disorders to diabetes and cancer. In this context, the potential of KD, the "High-fat, low-carbohydrate, adequate-protein" diet strategy, is increasingly being realized. In this article, we provide a comprehensive analysis of the benefits of KD against many diseases and discuss the underlying biochemical mechanisms. We hope that our write-up will stimulate further research on KD and help generate an interest for the populations to adopt this healthy diet. It can help overcome the problems associated with weight and dysregulated metabolism.
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Affiliation(s)
- Rui-Jun Li
- The Handsurgery Department, The First Hospital of Jilin University, Changchun, China
| | - Yang Liu
- The Handsurgery Department, The First Hospital of Jilin University, Changchun, China
| | - Huan-Qiu Liu
- The Anesthesia Department, The First Hospital of Jilin University, Changchun, China
| | - Ji Li
- The Anesthesia Department, The First Hospital of Jilin University, Changchun, China
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35
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Mudgal R, Mahajan S, Tomar S. Inhibition of Chikungunya virus by an adenosine analog targeting the SAM-dependent nsP1 methyltransferase. FEBS Lett 2019; 594:678-694. [PMID: 31623018 PMCID: PMC7164056 DOI: 10.1002/1873-3468.13642] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/23/2019] [Accepted: 10/02/2019] [Indexed: 01/02/2023]
Abstract
Alphaviruses, including Chikungunya (CHIKV) and Venezuelan equine encephalitis virus (VEEV), are among the leading causes of recurrent epidemics all over the world. Alphaviral nonstructural protein 1 (nsP1) orchestrates the capping of nascent viral RNA via its S-adenosyl methionine-dependent N-7-methyltransferase (MTase) and guanylyltransferase activities. Here, we developed and validated a novel capillary electrophoresis (CE)-based assay for measuring the MTase activity of purified VEEV and CHIKV nsP1. We employed the assay to assess the MTase inhibition efficiency of a few adenosine analogs and identified 5-iodotubercidin (5-IT) as an inhibitor of nsP1. The antiviral potency of 5-IT was evaluated in vitro using a combination of cell-based assays, which suggest that 5-IT is efficacious against CHIKV in cell culture (EC50 : 0.409 µm).
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Affiliation(s)
- Rajat Mudgal
- Department of Biotechnology, Indian Institute of Technology Roorkee, India
| | - Supreeti Mahajan
- Department of Biotechnology, Indian Institute of Technology Roorkee, India
| | - Shailly Tomar
- Department of Biotechnology, Indian Institute of Technology Roorkee, India
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36
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Reklow RJ, Alvares TS, Zhang Y, Miranda Tapia AP, Biancardi V, Katzell AK, Frangos SM, Hansen MA, Toohey AW, Cass CE, Young JD, Pagliardini S, Boison D, Funk GD. The Purinome and the preBötzinger Complex - A Ménage of Unexplored Mechanisms That May Modulate/Shape the Hypoxic Ventilatory Response. Front Cell Neurosci 2019; 13:365. [PMID: 31496935 PMCID: PMC6712068 DOI: 10.3389/fncel.2019.00365] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022] Open
Abstract
Exploration of purinergic signaling in brainstem homeostatic control processes is challenging the traditional view that the biphasic hypoxic ventilatory response, which comprises a rapid initial increase in breathing followed by a slower secondary depression, reflects the interaction between peripheral chemoreceptor-mediated excitation and central inhibition. While controversial, accumulating evidence supports that in addition to peripheral excitation, interactions between central excitatory and inhibitory purinergic mechanisms shape this key homeostatic reflex. The objective of this review is to present our working model of how purinergic signaling modulates the glutamatergic inspiratory synapse in the preBötzinger Complex (key site of inspiratory rhythm generation) to shape the hypoxic ventilatory response. It is based on the perspective that has emerged from decades of analysis of glutamatergic synapses in the hippocampus, where the actions of extracellular ATP are determined by a complex signaling system, the purinome. The purinome involves not only the actions of ATP and adenosine at P2 and P1 receptors, respectively, but diverse families of enzymes and transporters that collectively determine the rate of ATP degradation, adenosine accumulation and adenosine clearance. We summarize current knowledge of the roles played by these different purinergic elements in the hypoxic ventilatory response, often drawing on examples from other brain regions, and look ahead to many unanswered questions and remaining challenges.
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Affiliation(s)
- Robert J. Reklow
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Tucaaue S. Alvares
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Yong Zhang
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ana P. Miranda Tapia
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Vivian Biancardi
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Alexis K. Katzell
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Sara M. Frangos
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Megan A. Hansen
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Alexander W. Toohey
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Carol E. Cass
- Professor Emerita, Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - James D. Young
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Silvia Pagliardini
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School and New Jersey Medical School, Rutgers University, New Brunswick, NJ, United States
| | - Gregory D. Funk
- Department of Physiology, Women and Children’s Health Research Institute, Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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37
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Hendricks WD, Westbrook GL, Schnell E. Early detonation by sprouted mossy fibers enables aberrant dentate network activity. Proc Natl Acad Sci U S A 2019; 116:10994-10999. [PMID: 31085654 PMCID: PMC6561181 DOI: 10.1073/pnas.1821227116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In temporal lobe epilepsy, sprouting of hippocampal mossy fiber axons onto dentate granule cell dendrites creates a recurrent excitatory network. However, unlike mossy fibers projecting to CA3, sprouted mossy fiber synapses depress upon repetitive activation. Thus, despite their proximal location, relatively large presynaptic terminals, and ability to excite target neurons, the impact of sprouted mossy fiber synapses on hippocampal hyperexcitability is unclear. We find that despite their short-term depression, single episodes of sprouted mossy fiber activation in hippocampal slices initiated bursts of recurrent polysynaptic excitation. Consistent with a contribution to network hyperexcitability, optogenetic activation of sprouted mossy fibers reliably triggered action potential firing in postsynaptic dentate granule cells after single light pulses. This pattern resulted in a shift in network recruitment dynamics to an "early detonation" mode and an increased probability of release compared with mossy fiber synapses in CA3. A lack of tonic adenosine-mediated inhibition contributed to the higher probability of glutamate release, thus facilitating reverberant circuit activity.
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Affiliation(s)
- William D Hendricks
- Neuroscience Graduate Program, Vollum Institute, Oregon Health & Science University, Portland, OR 97239
- Department of Anesthesiology and Perioperative Medicine; Oregon Health & Science University, Portland, OR 97239
| | - Gary L Westbrook
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239
| | - Eric Schnell
- Department of Anesthesiology and Perioperative Medicine; Oregon Health & Science University, Portland, OR 97239;
- Veterans Affairs Portland Health Care System, Portland, OR 97239
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38
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El-Kharrag R, Owen R, Boison D. Adenosine Kinase Deficiency Increases Susceptibility to a Carcinogen. J Caffeine Adenosine Res 2019; 9:4-11. [PMID: 30944910 DOI: 10.1089/caff.2018.0019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background: Adenosine kinase (ADK) is a key regulator of hepatic metabolism. Its deficiency in the liver causes hepatic steatosis and methylation defects. In this study, we investigated whether reduced ADK expression affects the susceptibility of the liver to a carcinogen. Methods: We investigated ADK expression in samples from 11 liver cancer patients. We used transgenic Adk-tg mice with reduced hepatic ADK to study their susceptibility to a carcinogen. We exposed 45 Adk-tg and 21 wild-type (WT) mice to the carcinogen diethylnitrosamine (DEN) and the tumor promoter phenobarbital (PB) and examined the survival and body weight. Results: Seven of 11 patients with liver cancer had reduced ADK expression. A Kaplan-Meier survival curve showed a significantly increased mortality rate of DEN/PB-exposed Adk-tg mice compared with WT mice. Conclusions: Reduced hepatic ADK increases the susceptibility to the acute toxic effects of a carcinogen. Low hepatic ADK might be a risk factor and biomarker for cancer development.
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Affiliation(s)
- Rkia El-Kharrag
- Department of Neurobiology, Legacy Research Institute, Portland, Oregon
| | - Randy Owen
- Department of Neurobiology, Legacy Research Institute, Portland, Oregon
| | - Detlev Boison
- Department of Neurobiology, Legacy Research Institute, Portland, Oregon
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39
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Sandau US, Yahya M, Bigej R, Friedman JL, Saleumvong B, Boison D. Transient use of a systemic adenosine kinase inhibitor attenuates epilepsy development in mice. Epilepsia 2019; 60:615-625. [PMID: 30815855 DOI: 10.1111/epi.14674] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Over one-third of all patients with epilepsy are refractory to treatment and there is an urgent need to develop new drugs that can prevent the development and progression of epilepsy. Epileptogenesis is characterized by distinct histopathologic and biochemical changes, which include astrogliosis and increased expression of the adenosine-metabolizing enzyme adenosine kinase (ADK; EC 2.7.1.20). Increased expression of ADK contributes to epileptogenesis and is therefore a target for therapeutic intervention. We tested the prediction that the transient use of an ADK inhibitor administered during the latent phase of epileptogenesis can mitigate the development of epilepsy. METHODS We used the intrahippocampal kainic acid (KA) mouse model of temporal lobe epilepsy, which is characterized by ipsilateral hippocampal sclerosis with granule cell dispersion and the development of recurrent hippocampal paroxysmal discharges (HPDs). KA-injected mice were treated with the ADK inhibitor 5-iodotubercidin (5-ITU, 1.6 mg/kg, b.i.d., i.p.) during the latent phase of epileptogenesis from day 3-8 after injury; the period when gradual increases in hippocampal ADK expression begin to manifest. HPDs were assessed at 6 and 9 weeks after KA administration followed by epilepsy histopathology including assessment of granule cell dispersion, astrogliosis, and ADK expression. RESULTS 5-ITU significantly reduced the percent time in seizures by at least 80% in 56% of mice at 6 weeks post-KA. This reduction in seizure activity was maintained in 40% of 5-ITU-treated mice at 9 weeks. 5-ITU also suppressed granule cell dispersion and prevented maladaptive ADK increases in these protected mice. SIGNIFICANCE Our results show that the transient use of a small-molecule ADK inhibitor, given during the early stages of epileptogenesis, has antiepileptogenic disease-modifying properties, which provides the rationale for further investigation into the development of a novel class of antiepileptogenic ADK inhibitors with increased efficacy for epilepsy prevention.
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Affiliation(s)
- Ursula S Sandau
- RS Dow Neurobiology Laboratories, Portland, Oregon.,Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, Oregon
| | | | - Ryan Bigej
- RS Dow Neurobiology Laboratories, Portland, Oregon
| | | | | | - Detlev Boison
- RS Dow Neurobiology Laboratories, Portland, Oregon.,Department of Neurology, Oregon Health and Science University, Portland, Oregon
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40
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Mazumder AG, Patial V, Singh D. Mycophenolate mofetil contributes to downregulation of the hippocampal interleukin type 2 and 1β mediated PI3K/AKT/mTOR pathway hyperactivation and attenuates neurobehavioral comorbidities in a rat model of temporal lobe epilepsy. Brain Behav Immun 2019; 75:84-93. [PMID: 30243822 DOI: 10.1016/j.bbi.2018.09.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 08/13/2018] [Accepted: 09/19/2018] [Indexed: 12/24/2022] Open
Abstract
The role of neuroinflammatory mediators has been well established in the pathogenesis of temporal lobe epilepsy (TLE) and associated neurobehavioral comorbidities. Mycophenolate mofetil (MMF) is commonly used as an immunosuppressant in organ transplantations. Its neuroprotective effect is well explored in different preclinical and clinical studies. The present study was designed to investigate the effect of MMF in rat model of lithium pilocarpine (LiPc)-induced spontaneous recurrent seizures and its associated neurobehavioral comorbidities. MMF treatment showed a dose-dependent decrease in seizure severity and reduced aggression in epileptic rats. There was marked improvement in spatial and recognition memory functions, along with substantial decrease in depression-like behavior in MMF treated epileptic rats. There was considerable decrease in mossy fiber sprouting in the dentate gyrus and the cornu ammonis 3 regions of the hippocampus, along with reduction in neuronal death in the treated groups. Furthermore, the hippocampal mRNA level of IL-1β, IL-2, PI3K, AKT, HIF-1α, RAPTOR, mTOR, Rps6kb1 and Rps6 was found to be decreased in MMF treated animals. mTOR, S6, pS6 and GFAP protein expression was decreased, whereas NeuN was increased in the rat hippocampus of the treated animals. The results concluded that MMF suppress recurrent seizures, and improves its associated behavioral impairments and cognitive deficit in rat model of TLE. The observed effects of MMF be correlated with the inhibition of IL-2 and IL-1β linked PI3K/AKT/mTOR signaling pathway hyperactivation.
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Affiliation(s)
- Arindam Ghosh Mazumder
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India
| | - Vikram Patial
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India
| | - Damanpreet Singh
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India.
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Wellmann M, Álvarez-Ferradas C, Maturana CJ, Sáez JC, Bonansco C. Astroglial Ca 2+-Dependent Hyperexcitability Requires P2Y 1 Purinergic Receptors and Pannexin-1 Channel Activation in a Chronic Model of Epilepsy. Front Cell Neurosci 2018; 12:446. [PMID: 30542266 PMCID: PMC6277884 DOI: 10.3389/fncel.2018.00446] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 11/06/2018] [Indexed: 12/31/2022] Open
Abstract
Astrocytes from the hippocampus of chronic epileptic rats exhibit an abnormal pattern of intracellular calcium oscillations, characterized by an augmented frequency of long lasting spontaneous Ca2+ transients, which are sensitive to purinergic receptor antagonists but resistant to tetrodotoxin. The above suggests that alterations in astroglial Ca2+-dependent excitability observed in the epileptic tissue could arise from changes in astrocyte-to-astrocyte signaling, which is mainly mediated by purines in physiological and pathological conditions. In spite of that, how purinergic signaling contributes to astrocyte dysfunction in epilepsy remains unclear. Here, we assessed the possible contribution of P2Y1R as well as pannexin1 and connexin43 hemichannels—both candidates for non-vesicular ATP-release—by performing astroglial Ca2+ imaging and dye uptake experiments in hippocampal slices from control and fully kindled rats. P2Y1R blockade with MRS2179 decreased the mean duration of astroglial Ca2+ oscillations by reducing the frequency of slow Ca2+ transients, and thereby restoring the balance between slow (ST) and fast transients (FT) in the kindled group. The potential contribution of astroglial pannexin1 and connexin43 hemichannels as pathways for purine release (e.g., ATP) was assessed through dye uptake experiments. Astrocytes from kindled hippocampi exhibit three-fold more EtBr uptake than controls, whereby pannexin1 hemichannels (Panx1 HCs) accounts for almost all dye uptake with only a slight contribution from connexin43 hemichannels (Cx43 HCs). Confirming its functional involvement, Panx1 HCs inhibition decreased the mean duration of astroglial Ca2+ transients and the frequency of slow oscillations in kindled slices, but had no noticeable effects on the control group. As expected, Cx43 HCs blockade did not have any effects over the mean duration of astroglial Ca2+ oscillations. These findings suggest that P2Y1R and Panx1 HCs play a pivotal role in astroglial pathophysiology, which would explain the upregulation of glutamatergic neurotransmission in the epileptic brain and thus represents a new potential pharmacological target for the treatment of drug-refractory epilepsy.
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Affiliation(s)
- Mario Wellmann
- Centro de Neurobiología y Plasticidad Cerebral CNPC, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Fonoaudiología, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Carla Álvarez-Ferradas
- Centro de Neurobiología y Plasticidad Cerebral CNPC, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Ciencias de la Salud, Universidad Viña del Mar, Valparaíso, Chile
| | - Carola J Maturana
- Departamento de Ciencias Fisiológicas, Facultad Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Juan C Sáez
- Departamento de Ciencias Fisiológicas, Facultad Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Christian Bonansco
- Centro de Neurobiología y Plasticidad Cerebral CNPC, Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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New Roles for Old Glue: Astrocyte Function in Synaptic Plasticity and Neurological Disorders. Int Neurourol J 2018; 22:S106-114. [PMID: 30396259 PMCID: PMC6234728 DOI: 10.5213/inj.1836214.107] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 10/10/2018] [Indexed: 01/02/2023] Open
Abstract
Previously believed to solely play a supportive role in the central nervous system, astrocytes are now considered active players in normal brain function. Evidence in recent decades extends their contributions beyond the classically held brain glue role; it's now known that astrocytes act as a unique excitable component with functions extending into local network modulation, synaptic plasticity, and memory formation, and postinjury repair. In this review article, we highlight our growing understanding of astrocyte function and physiology, the increasing role of gliotransmitters in neuron-glia communication, and the role of astrocytes in modulating synaptic plasticity and cognitive function. Owing to the duality of both beneficial and deleterious roles attributed to astrocytes, we also discuss the implications of this new knowledge as it applies to neurological disorders including Alzheimer disease, epilepsy, and schizophrenia.
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Estiri H, Fallah A, Soleimani M, Aliaghaei A, Karimzadeh F, Babaei Abraki S, Ghahremani MH. Stable Knockdown of Adenosine Kinase by Lentiviral Anti-ADK miR-shRNAs in Wharton's Jelly Stem Cells. CELL JOURNAL 2017; 20:1-9. [PMID: 29308612 PMCID: PMC5759670 DOI: 10.22074/cellj.2018.4916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/09/2017] [Indexed: 12/02/2022]
Abstract
Objective In this study, we describe an efficient approach for stable knockdown of adenosine kinase (ADK) using lentiviral
system, in an astrocytoma cell line and in human Wharton’s jelly mesenchymal stem cells (hWJMSCs). These sources of stem
cells besides having multilineage differentiation potential and immunomodulatory activities, are easily available in unlimited
numbers, do not raise ethical concerns and are attractive for gene manipulation and cell-based gene therapy.
Materials and Methods In this experimental study, we targeted adenosine kinase mRNA at 3' and performed coding
sequences using eight miR-based expressing cassettes of anti-ADK short hairpin RNA (shRNAs). First, these cassettes with
scrambled control sequences were cloned into expressing lentiviral pGIPZ vector. Quantitative real time-polymerase chain
reaction (qRT-PCR) was used to screen multi-cassettes anti-ADK miR-shRNAs in stably transduced U-251 MG cell line and
measuring ADK gene expression at mRNA level. Extracted WJMSCs were characterized using flow cytometry for expressing
mesenchymal specific marker (CD44+) and lack of expression of hematopoietic lineage marker (CD45-). Then, the lentiviral
vector that expressed the most efficient anti-ADK miR-shRNA, was employed to stably transduce WJMSCs.
Results Transfection of anti-ADK miR-shRNAs in HEK293T cells using CaPO4 method showed high efficiency. We
successfully transduced U-251 cell line by recombinant lentiviruses and screened eight cassettes of anti-ADK miR-
shRNAs in stably transduced U-251 MG cell line by qRT-PCR. RNAi-mediated down-regulation of ADK by lentiviral
system indicated up to 95% down-regulation of ADK. Following lentiviral transduction of WJMSCs with anti-ADK miR-
shRNA expression cassette, we also implicated, down-regulation of ADK up to 95% by qRT-PCR and confirmed it by
western blot analysis at the protein level.
Conclusion Our findings indicate efficient usage of shRNA cassette for ADK knockdown. Engineered WJMSCs with
genome editing methods like CRISPR/cas9 or more safe viral systems such as adeno-associated vectors (AAV) might
be an attractive source in cell-based gene therapy and may have therapeutic potential for epilepsy.
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Affiliation(s)
- Hajar Estiri
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Iranian Institute of Cell and Gene therapy, Tehran, Iran
| | - Ali Fallah
- Bioviva Science USA, Seattle, USA.,Iranian Institute of Cell and Gene therapy, Tehran, Iran
| | - Masoud Soleimani
- Department of Hematology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Abbas Aliaghaei
- Neuroscience Lab, Department of Anatomy and Cell Biology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Karimzadeh
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mohammad Hossein Ghahremani
- Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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Disrupted Neuroglial Metabolic Coupling after Peripheral Surgery. J Neurosci 2017; 38:452-464. [PMID: 29175959 DOI: 10.1523/jneurosci.1797-17.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 02/07/2023] Open
Abstract
Immune-related events in the periphery can remotely affect brain function, contributing to neurodegenerative processes and cognitive decline. In mice, peripheral surgery induces a systemic inflammatory response associated with changes in hippocampal synaptic plasticity and transient cognitive decline, however, the underlying mechanisms remain unknown. Here we investigated the effect of peripheral surgery on neuronal-glial function within hippocampal neuronal circuits of relevance to cognitive processing in male mice at 6, 24, and 72 h postsurgery. At 6 h we detect the proinflammatory cytokine IL-6 in the hippocampus, followed up by alterations in the mRNA and protein expression of astrocytic and neuronal proteins necessary for optimal energy supply to the brain and for the reuptake and recycling of glutamate in the synapse. Similarly, at 24 h postsurgery the mRNA expression of structural proteins (GFAP and AQP4) was compromised. At this time point, functional analysis in astrocytes revealed a decrease in resting calcium signaling. Examination of neuronal activity by whole-cell patch-clamp shows elevated levels of glutamatergic transmission and changes in AMPA receptor subunit composition at 72 h postsurgery. Finally, lactate, an essential energy substrate produced by astrocytes and critical for memory formation, decreases at 6 and 72 h after surgery. Based on temporal parallels with our previous studies, we propose that the previously reported cognitive decline observed at 72 h postsurgery in mice might be the consequence of temporal hippocampal metabolic, structural, and functional changes in astrocytes that lead to a disruption of the neuroglial metabolic coupling and consequently to a neuronal dysfunction.SIGNIFICANCE STATEMENT A growing body of evidence suggests that surgical trauma launches a systemic inflammatory response that reaches the brain and associates with immune activation and cognitive decline. Understanding the mechanisms by which immune-related events in the periphery can influence brain processes is essential for the development of therapies to prevent or treat postoperative cognitive dysfunction and other forms of cognitive decline related to immune-to-brain communication, such as Alzheimer's and Parkinson's diseases. Here we describe the temporal orchestration of a series of metabolic, structural, and functional changes after aseptic trauma in mice related to astrocytes and later in neurons that emphasize the role of astrocytes as key intermediaries between peripheral immune events, neuronal processing, and potentially cognition.
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45
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Boison D, Steinhäuser C. Epilepsy and astrocyte energy metabolism. Glia 2017; 66:1235-1243. [PMID: 29044647 DOI: 10.1002/glia.23247] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/29/2017] [Accepted: 10/02/2017] [Indexed: 12/17/2022]
Abstract
Epilepsy is a complex neurological syndrome characterized by neuronal hyperexcitability and sudden, synchronized electrical discharges that can manifest as seizures. It is now increasingly recognized that impaired astrocyte function and energy homeostasis play key roles in the pathogenesis of epilepsy. Excessive neuronal discharges can only happen, if adequate energy sources are made available to neurons. Conversely, energy depletion during seizures is an endogenous mechanism of seizure termination. Astrocytes control neuronal energy homeostasis through neurometabolic coupling. In this review, we will discuss how astrocyte dysfunction in epilepsy leads to distortion of key metabolic and biochemical mechanisms. Dysfunctional glutamate metabolism in astrocytes can directly contribute to neuronal hyperexcitability. Closure of astrocyte intercellular gap junction coupling as observed early during epileptogenesis limits activity-dependent trafficking of energy metabolites, but also impairs clearance of the extracellular space from accumulation of K+ and glutamate. Dysfunctional astrocytes also increase the metabolism of adenosine, a metabolic product of ATP degradation that broadly inhibits energy-consuming processes as an evolutionary adaptation to conserve energy. Due to the critical role of astroglial energy homeostasis in the control of neuronal excitability, metabolic therapeutic approaches that prevent the utilization of glucose might represent a potent antiepileptic strategy. In particular, high fat low carbohydrate "ketogenic diets" as well as inhibitors of glycolysis and lactate metabolism are of growing interest for the therapy of epilepsy.
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Affiliation(s)
- Detlev Boison
- R.S. Dow Neurobiology Laboratories, Legacy Research Institute, Portland, Oregon
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46
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Senter RK, Ghoshal A, Walker AG, Xiang Z, Niswender CM, Conn PJ. The Role of mGlu Receptors in Hippocampal Plasticity Deficits in Neurological and Psychiatric Disorders: Implications for Allosteric Modulators as Novel Therapeutic Strategies. Curr Neuropharmacol 2017; 14:455-73. [PMID: 27296640 PMCID: PMC4983746 DOI: 10.2174/1570159x13666150421003225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/18/2015] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are two distinct forms of synaptic plasticity that have been extensively characterized at the Schaffer collateral-CA1 (SCCA1) synapse and the mossy fiber (MF)-CA3 synapse within the hippocampus, and are postulated to be the molecular underpinning for several cognitive functions. Deficits in LTP and LTD have been implicated in the pathophysiology of several neurological and psychiatric disorders. Therefore, there has been a large effort focused on developing an understanding of the mechanisms underlying these forms of plasticity and novel therapeutic strategies that improve or rescue these plasticity deficits. Among many other targets, the metabotropic glutamate (mGlu) receptors show promise as novel therapeutic candidates for the treatment of these disorders. Among the eight distinct mGlu receptor subtypes (mGlu1-8), the mGlu1,2,3,5,7 subtypes are expressed throughout the hippocampus and have been shown to play important roles in the regulation of synaptic plasticity in this brain area. However, development of therapeutic agents that target these mGlu receptors has been hampered by a lack of subtype-selective compounds. Recently, discovery of allosteric modulators of mGlu receptors has provided novel ligands that are highly selective for individual mGlu receptor subtypes. The mGlu receptors modulate the multiple forms of synaptic plasticity at both SC-CA1 and MF synapses and allosteric modulators of mGlu receptors have emerged as potential therapeutic agents that may rescue plasticity deficits and improve cognitive function in patients suffering from multiple neurological and psychiatric disorders.
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Affiliation(s)
| | | | | | | | | | - P Jeffrey Conn
- Department of Pharmacology, Faculty of Vanderbilt University Medical Center, 1205 Light Hall, Nashville, TN 37232, USA.
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47
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Ren G, Boison D. Engineering Human Mesenchymal Stem Cells to Release Adenosine Using miRNA Technology. Methods Mol Biol 2017; 1622:225-239. [PMID: 28674812 DOI: 10.1007/978-1-4939-7108-4_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Adenosine is an important modulator of metabolic activity with powerful tissue and cell protective functions. Adenosine kinase (ADK), the major adenosine-regulating enzyme, is critical to adapt its intra- and extracellular levels in response to environmental changes. Lentiviral RNAi-mediated downregulation of ADK in human mesenchymal stem cells (hMSCs) has therefore been considered an effective tool for engineering therapeutically effective adenosine-releasing cell grafts that could constitute patient-identical autologous implants for clinical application. We constructed lentiviral vectors that co-express miRNA directed against ADK and an emerald green fluorescent protein (EmGFP) reporter gene. Following lentiviral transduction of hMSCs, we demonstrated up to 80% downregulation of ADK and 98% transduction efficiency. Transduced hMSCs continued to express EmGFP after four to six consecutive passages, and EmGFP-positive hMSC grafts survived in the hippocampal fissure of mouse brains and provided efficient adenosine-dependent neuroprotection in a mouse model of seizure-induced cell loss.
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Affiliation(s)
- Gaoying Ren
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA. .,Physiology and Pharmacology, Oregon Health and Science University, BRB 640B, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
| | - Detlev Boison
- Robert S Dow Neurobiology Laboratories, Legacy Research, Portland, OR, 97232, USA
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48
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Yamashiro K, Morita M. Novel aspects of extracellular adenosine dynamics revealed by adenosine sensor cells. Neural Regen Res 2017; 12:881-885. [PMID: 28761414 PMCID: PMC5514856 DOI: 10.4103/1673-5374.208544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adenosine modulates diverse physiological and pathological processes in the brain, including neuronal activities, blood flow, and inflammation. However, the mechanisms underlying the dynamics of extracellular adenosine are not fully understood. We have recently developed a novel biosensor, called an adenosine sensor cell, and we have characterized the neuronal and astrocytic pathways for elevating extracellular adenosine. In this review, the physiological implications and therapeutic potential of the pathways revealed by the adenosine sensor cells are discussed. We propose that the multiple pathways regulating extracellular adenosine allow for the diverse functions of this neuromodulator, and their malfunctions cause various neurological and psychiatric disorders.
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Affiliation(s)
- Kunihiko Yamashiro
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.,Department of NCNP Brain Physiology and Pathology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan.,Department of Biology, Kobe University Graduate School of Sciences, Kobe, Japan
| | - Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Sciences, Kobe, Japan
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49
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Kiese K, Jablonski J, Boison D, Kobow K. Dynamic Regulation of the Adenosine Kinase Gene during Early Postnatal Brain Development and Maturation. Front Mol Neurosci 2016; 9:99. [PMID: 27812320 PMCID: PMC5071315 DOI: 10.3389/fnmol.2016.00099] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/26/2016] [Indexed: 12/02/2022] Open
Abstract
The ubiquitous metabolic intermediary and nucleoside adenosine is a “master regulator” in all living systems. Under baseline conditions adenosine kinase (ADK) is the primary enzyme for the metabolic clearance of adenosine. By regulating the availability of adenosine, ADK is a critical upstream regulator of complex homeostatic and metabolic networks. Not surprisingly, ADK dysfunction is involved in several pathologies, including diabetes, epilepsy, and cancer. ADK protein exists in the two isoforms nuclear ADK-L, and cytoplasmic ADK-S, which are subject to dynamic expression changes during brain development and in response to brain injury; however, gene expression changes of the Adk gene as well as regulatory mechanisms that direct the cell-type and isoform specific expression of ADK have never been investigated. Here we analyzed potential gene regulatory mechanisms that may influence Adk expression including DNA promoter methylation, histone modifications and transcription factor binding. Our data suggest binding of transcription factor SP1 to the Adk promoter influences the regulation of Adk expression.
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Affiliation(s)
- Katharina Kiese
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
| | - Janos Jablonski
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
| | - Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, OR, USA
| | - Katja Kobow
- Department of Neuropathology, University Hospital Erlangen Erlangen, Germany
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50
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Role of the purinergic signaling in epilepsy. Pharmacol Rep 2016; 69:130-138. [PMID: 27915186 DOI: 10.1016/j.pharep.2016.09.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 01/19/2023]
Abstract
Adenine nucleotides and adenosine are signaling molecules that activate purinergic receptors P1 and P2. Activation of A1 adenosine receptors has an anticonvulsant action, whereas activation of A2A receptors might initiate seizures. Therefore, a significant limitation to the use of A1 receptor agonists as drugs in the CNS might be their peripheral side effects. The anti-epileptic activity of adenosine is related to its increased concentration outside the cell. This increase might result from the inhibition of the equilibrative nucleoside transporters (ENTs). Moreover, the implantation of implants or stem cells into the brain might cause slow and persistent increases in adenosine concentrations in the extracellular spaces of the brain. The role of adenosine in seizure inhibition has been confirmed by results demonstrating that in patients with epilepsy, the adenosine kinase (ADK) present in astrocytes is the only purine-metabolizing enzyme that exhibits increased expression. Increased ADK activity causes intensified phosphorylation of adenosine to 5'-AMP, which therefore lowers the adenosine level in the extracellular spaces. These changes might initiate astrogliosis and epileptogenesis, which are the manifestations of epilepsy. Seizures might induce inflammatory processes and vice versa. Activation of P2X7 receptors causes intensified release of pro-inflammatory cytokines (IL-1β and TNF-α) and activates metabolic pathways that induce inflammatory processes in the CNS. Therefore, antagonists of P2X7 and the interleukin 1β receptor might be efficient drugs for recurring seizures and prolonged status epilepticus. Inhibitors of ADK would simultaneously inhibit the seizures, prevent the astrogliosis and epileptogenesis processes and prevent the formation of new epileptogenic foci. Therefore, these drugs might become beneficial seizure-suppressing drugs.
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