1
|
Abdennadher M, Jacobellis S, Václavů L, Juttukonda M, Inati S, Goldstein L, van Osch MJP, Rosen B, Hua N, Theodore W. Water exchange across the blood-brain barrier and epilepsy: Review on pathophysiology and neuroimaging. Epilepsia Open 2024; 9:1123-1135. [PMID: 38884502 PMCID: PMC11296120 DOI: 10.1002/epi4.12994] [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: 10/27/2023] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 06/18/2024] Open
Abstract
The blood-brain barrier (BBB) is a barrier protecting the brain and a milieu of continuous exchanges between blood and brain. There is emerging evidence that the BBB plays a major role in epileptogenesis and drug-resistant epilepsy, through several mechanisms, such as water homeostasis dysregulation, overexpression of drug transporters, and inflammation. Studies have shown abnormal water homeostasis in epileptic tissue and altered aquaporin-4 water channel expression in animal epilepsy models. This review focuses on abnormal water exchange in epilepsy and describes recent non-invasive MRI methods of quantifying water exchange. PLAIN LANGUAGE SUMMARY: Abnormal exchange between blood and brain contribute to seizures and epilepsy. The authors describe why correct water balance is necessary for healthy brain functioning and how it is impacted in epilepsy. This review also presents recent MRI methods to measure water exchange in human brain. These measures would improve our understanding of factors leading to seizures.
Collapse
Affiliation(s)
- Myriam Abdennadher
- Neurology Department, Boston Medical CenterBoston University Chobanian & Avedisian School of MedicineBostonMassachusettsUSA
| | - Sara Jacobellis
- Boston University Chobanian & Avedisian School of MedicineBostonMassachusettsUSA
| | - Lena Václavů
- C.J. Gorter MRI Center, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Meher Juttukonda
- Athinoula A. Martinos Center of Biomedical Imaging, Department of Radiology, Massachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Sara Inati
- National Institute of Neurological Disorders and Stroke, NIHBethesdaMarylandUSA
| | - Lee Goldstein
- Psychiatry and Neurology DepartmentBoston University Chobanian & Avedisian School of MedicineBostonMassachusettsUSA
| | - Matthias J. P. van Osch
- C.J. Gorter MRI Center, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Bruce Rosen
- Athinoula A. Martinos Center of Biomedical Imaging, Department of Radiology, Massachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Ning Hua
- Radiology Department, Boston Medical CenterBoston University Chobanian & Avedisian School of MedicineBostonMassachusettsUSA
| | - William Theodore
- National Institute of Neurological Disorders and Stroke, NIHBethesdaMarylandUSA
| |
Collapse
|
2
|
Rostami F, Jaafari Suha A, Janahmadi M, Hosseinmardi N. Aquaporin-4 inhibition attenuates Pentylenetetrazole-induced behavioral seizures and cognitive impairments in kindled rats. Physiol Behav 2024; 278:114521. [PMID: 38492911 DOI: 10.1016/j.physbeh.2024.114521] [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: 10/10/2023] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
Epilepsy is a neurological condition distinguished by recurrent and unexpected seizures. Astrocytic channels and transporters are essential for maintaining normal neuronal functionality. The astrocytic water channel, aquaporin-4 (AQP4), which plays a pivotal role in regulating water homeostasis, is a potential target for epileptogenesis. In present study, we examined the effect of different doses (10, 50, 100 μM and 5 mM) of AQP4 inhibitor, 2-nicotinamide-1, 3, 4-thiadiazole (TGN-020), during kindling acquisition, on seizure parameters and seizure-induced cognitive impairments. Animals were kindled by injection of pentylenetetrazole (PTZ: 37.5 mg/kg, i.p.). TGN-020 was administered into the right lateral cerebral ventricle 30 min before PTZ every alternate day. Seizure parameters were assessed 20 min after PTZ administration. One day following the last PTZ injection, memory performance was investigated using spontaneous alternation in Y-maze and novel object recognition (NOR) tests. The inhibition of AQP4 during the kindling process significantly decreased the maximal seizure stage and seizure duration (two-way ANOVA, P = 0.0001) and increased the latency of seizure onset and the number of PTZ injections required to induce different seizure stages (one-way ANOVA, P = 0.0001). Compared to kindled rats, the results of the NOR tests showed that AQP4 inhibition during PTZ-kindling prevented recognition memory impairment. Based on these results, AQP4 could be involved in seizure development and seizure-induced cognitive impairment. More investigation is required to fully understand the complex interactions between seizure activity, water homeostasis, and cognitive dysfunction, which may help identify potential therapeutic targets for these conditions.
Collapse
Affiliation(s)
- Fatemeh Rostami
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Jaafari Suha
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
3
|
Enger R, Heuser K. Astrocytes as critical players of the fine balance between inhibition and excitation in the brain: spreading depolarization as a mechanism to curb epileptic activity. FRONTIERS IN NETWORK PHYSIOLOGY 2024; 4:1360297. [PMID: 38405021 PMCID: PMC10884165 DOI: 10.3389/fnetp.2024.1360297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 01/25/2024] [Indexed: 02/27/2024]
Abstract
Spreading depolarizations (SD) are slow waves of complete depolarization of brain tissue followed by neuronal silencing that may play a role in seizure termination. Even though SD was first discovered in the context of epilepsy research, the link between SD and epileptic activity remains understudied. Both seizures and SD share fundamental pathophysiological features, and recent evidence highlights the frequent occurrence of SD in experimental seizure models. Human data on co-occurring seizures and SD are limited but suggestive. This mini-review addresses possible roles of SD during epileptiform activity, shedding light on SD as a potential mechanism for terminating epileptiform activity. A common denominator for many forms of epilepsy is reactive astrogliosis, a process characterized by morphological and functional changes to astrocytes. Data suggest that SD mechanisms are potentially perturbed in reactive astrogliosis and we propose that this may affect seizure pathophysiology.
Collapse
Affiliation(s)
- Rune Enger
- Letten Centre and GliaLab, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Kjell Heuser
- Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| |
Collapse
|
4
|
Tukacs V, Mittli D, Hunyadi-Gulyás É, Darula Z, Juhász G, Kardos J, Kékesi KA. Comparative analysis of hippocampal extracellular space uncovers widely altered peptidome upon epileptic seizure in urethane-anaesthetized rats. Fluids Barriers CNS 2024; 21:6. [PMID: 38212833 PMCID: PMC10782730 DOI: 10.1186/s12987-024-00508-w] [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: 08/24/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND The brain extracellular fluid (ECF), composed of secreted neurotransmitters, metabolites, peptides, and proteins, may reflect brain processes. Analysis of brain ECF may provide new potential markers for synaptic activity or brain damage and reveal additional information on pathological alterations. Epileptic seizure induction is an acute and harsh intervention in brain functions, and it can activate extra- and intracellular proteases, which implies an altered brain secretome. Thus, we applied a 4-aminopyridine (4-AP) epilepsy model to study the hippocampal ECF peptidome alterations upon treatment in rats. METHODS We performed in vivo microdialysis in the hippocampus for 3-3 h of control and 4-AP treatment phase in parallel with electrophysiology measurement. Then, we analyzed the microdialysate peptidome of control and treated samples from the same subject by liquid chromatography-coupled tandem mass spectrometry. We analyzed electrophysiological and peptidomic alterations upon epileptic seizure induction by two-tailed, paired t-test. RESULTS We detected 2540 peptides in microdialysate samples by mass spectrometry analysis; and 866 peptides-derived from 229 proteins-were found in more than half of the samples. In addition, the abundance of 322 peptides significantly altered upon epileptic seizure induction. Several proteins of significantly altered peptides are neuropeptides (Chgb) or have synapse- or brain-related functions such as the regulation of synaptic vesicle cycle (Atp6v1a, Napa), astrocyte morphology (Vim), and glutamate homeostasis (Slc3a2). CONCLUSIONS We have detected several consequences of epileptic seizures at the peptidomic level, as altered peptide abundances of proteins that regulate epilepsy-related cellular processes. Thus, our results indicate that analyzing brain ECF by in vivo microdialysis and omics techniques is useful for monitoring brain processes, and it can be an alternative method in the discovery and analysis of CNS disease markers besides peripheral fluid analysis.
Collapse
Affiliation(s)
- Vanda Tukacs
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Dániel Mittli
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Éva Hunyadi-Gulyás
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Research Network (HUN-REN), Temesvári Körút 62, Szeged, 6726, Hungary
| | - Zsuzsanna Darula
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Research Network (HUN-REN), Temesvári Körút 62, Szeged, 6726, Hungary
- Single Cell Omics Advanced Core Facility, Hungarian Centre of Excellence for Molecular Medicine, Temesvári Körút 62, Szeged, 6726, Hungary
| | - Gábor Juhász
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- InnoScience Hungary Ltd., Bátori Út 9, Mátranovák, 3142, Hungary
| | - József Kardos
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Katalin Adrienna Kékesi
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
- InnoScience Hungary Ltd., Bátori Út 9, Mátranovák, 3142, Hungary.
- Department of Physiology and Neurobiology, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
| |
Collapse
|
5
|
Brazhe A, Verisokin A, Verveyko D, Postnov D. Astrocytes: new evidence, new models, new roles. Biophys Rev 2023; 15:1303-1333. [PMID: 37975000 PMCID: PMC10643736 DOI: 10.1007/s12551-023-01145-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/08/2023] [Indexed: 11/19/2023] Open
Abstract
Astrocytes have been in the limelight of active research for about 3 decades now. Over this period, ideas about their function and role in the nervous system have evolved from simple assistance in energy supply and homeostasis maintenance to a complex informational and metabolic hub that integrates data on local neuronal activity, sensory and arousal context, and orchestrates many crucial processes in the brain. Rapid progress in experimental techniques and data analysis produces a growing body of data, which can be used as a foundation for formulation of new hypotheses, building new refined mathematical models, and ultimately should lead to a new level of understanding of the contribution of astrocytes to the cognitive tasks performed by the brain. Here, we highlight recent progress in astrocyte research, which we believe expands our understanding of how low-level signaling at a cellular level builds up to processes at the level of the whole brain and animal behavior. We start our review with revisiting data on the role of noradrenaline-mediated astrocytic signaling in locomotion, arousal, sensory integration, memory, and sleep. We then briefly review astrocyte contribution to the regulation of cerebral blood flow regulation, which is followed by a discussion of biophysical mechanisms underlying astrocyte effects on different brain processes. The experimental section is closed by an overview of recent experimental techniques available for modulation and visualization of astrocyte dynamics. We then evaluate how the new data can be potentially incorporated into the new mathematical models or where and how it already has been done. Finally, we discuss an interesting prospect that astrocytes may be key players in important processes such as the switching between sleep and wakefulness and the removal of toxic metabolites from the brain milieu.
Collapse
Affiliation(s)
- Alexey Brazhe
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University, Leninskie Gory, 1/24, Moscow, 119234 Russia
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, GSP-7, Miklukho-Maklay Str., 16/10, Moscow, 117997 Russia
| | - Andrey Verisokin
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Darya Verveyko
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, Astrakhanskaya st., 83, Saratov, 410012 Russia
| |
Collapse
|
6
|
Bonosi L, Benigno UE, Musso S, Giardina K, Gerardi RM, Brunasso L, Costanzo R, Paolini F, Buscemi F, Avallone C, Gulino V, Iacopino DG, Maugeri R. The Role of Aquaporins in Epileptogenesis-A Systematic Review. Int J Mol Sci 2023; 24:11923. [PMID: 37569297 PMCID: PMC10418736 DOI: 10.3390/ijms241511923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/13/2023] Open
Abstract
Aquaporins (AQPs) are a family of membrane proteins involved in the transport of water and ions across cell membranes. AQPs have been shown to be implicated in various physiological and pathological processes in the brain, including water homeostasis, cell migration, and inflammation, among others. Epileptogenesis is a complex and multifactorial process that involves alterations in the structure and function of neuronal networks. Recent evidence suggests that AQPs may also play a role in the pathogenesis of epilepsy. In animal models of epilepsy, AQPs have been shown to be upregulated in regions of the brain that are involved in seizure generation, suggesting that they may contribute to the hyperexcitability of neuronal networks. Moreover, genetic studies have identified mutations in AQP genes associated with an increased risk of developing epilepsy. Our review aims to investigate the role of AQPs in epilepsy and seizure onset from a pathophysiological point of view, pointing out the potential molecular mechanism and their clinical implications.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Rosario Maugeri
- Neurosurgical Clinic, AOUP “Paolo Giaccone”, Post Graduate Residency Program in Neurologic Surgery, Department of Biomedicine Neurosciences and Advanced Diagnostics, School of Medicine, University of Palermo, 90127 Palermo, Italy; (L.B.); (U.E.B.); (S.M.); (K.G.); (R.M.G.); (L.B.); (R.C.); (F.P.); (F.B.); (C.A.); (V.G.); (D.G.I.)
| |
Collapse
|
7
|
Smith LA, Chen C, Lax NZ, Taylor RW, Erskine D, McFarland R. Astrocytic pathology in Alpers' syndrome. Acta Neuropathol Commun 2023; 11:86. [PMID: 37259148 DOI: 10.1186/s40478-023-01579-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 05/11/2023] [Indexed: 06/02/2023] Open
Abstract
Refractory epilepsy is the main neurological manifestation of Alpers' syndrome, a severe childhood-onset mitochondrial disease caused by bi-allelic pathogenic variants in the mitochondrial DNA (mtDNA) polymerase gamma gene (POLG). The pathophysiological mechanisms underpinning neuronal hyperexcitabilty leading to seizures in Alpers' syndrome remain unknown. However, pathological changes to reactive astrocytes are hypothesised to exacerbate neural dysfunction and seizure-associated cortical activity in POLG-related disease. Therefore, we sought to phenotypically characterise astrocytic pathology in Alpers' syndrome. We performed a detailed quantitative investigation of reactive astrocytes in post-mortem neocortical tissues from thirteen patients with Alpers' syndrome, eight neurologically normal controls and five sudden unexpected death in epilepsy (SUDEP) patients, to control for generalised epilepsy-associated astrocytic pathology. Immunohistochemistry to identify glial fibrillary acidic protein (GFAP)-reactive astrocytes revealed striking reactive astrogliosis localised to the primary visual cortex of Alpers' syndrome tissues, characterised by abnormal-appearing hypertrophic astrocytes. Phenotypic characterisation of individual GFAP-reactive astrocytes demonstrated decreased abundance of mitochondrial oxidative phosphorylation (OXPHOS) proteins and altered expression of key astrocytic proteins including Kir4.1 (subunit of the inwardly rectifying K+ ion channel), AQP4 (astrocytic water channel) and glutamine synthetase (enzyme that metabolises glutamate). These phenotypic astrocytic changes were typically different from the pathology observed in SUDEP tissues, suggesting alternative mechanisms of astrocytic dysfunction between these epilepsies. Crucially, our findings provide further evidence of occipital lobe involvement in Alpers' syndrome and support the involvement of reactive astrocytes in the pathogenesis of POLG-related disease.
Collapse
Affiliation(s)
- Laura A Smith
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Chun Chen
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and Children, Newcastle University, Newcastle Upon Tyne, Newcastle, NE2 4HH, UK
| | - Daniel Erskine
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and Children, Newcastle University, Newcastle Upon Tyne, Newcastle, NE2 4HH, UK.
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Elabasy A, Suhonen M, Rajna Z, Hosni Y, Kananen J, Annunen J, Ansakorpi H, Korhonen V, Seppänen T, Kiviniemi V. Respiratory brain impulse propagation in focal epilepsy. Sci Rep 2023; 13:5222. [PMID: 36997658 PMCID: PMC10063583 DOI: 10.1038/s41598-023-32271-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023] Open
Abstract
Respiratory brain pulsations pertaining to intra-axial hydrodynamic solute transport are markedly altered in focal epilepsy. We used optical flow analysis of ultra-fast functional magnetic resonance imaging (fMRI) data to investigate the velocity characteristics of respiratory brain impulse propagation in patients with focal epilepsy treated with antiseizure medication (ASM) (medicated patients with focal epilepsy; ME, n = 23), drug-naïve patients with at least one seizure (DN, n = 19) and matched healthy control subjects (HC, n = 75). We detected in the two patient groups (ME and DN) several significant alterations in the respiratory brain pulsation propagation velocity, which showed a bidirectional change dominated by a reduction in speed. Furthermore, the respiratory impulses moved more in reversed or incoherent directions in both patient groups vs. the HC group. The speed reductions and directionality changes occurred in specific phases of the respiratory cycle. In conclusion, irrespective of medication status, both patient groups showed incoherent and slower respiratory brain impulses, which may contribute to epileptic brain pathology by hindering brain hydrodynamics.
Collapse
Affiliation(s)
- Ahmed Elabasy
- Center for Machine Vision and Signal Analysis, University of Oulu, 90014, Oulu, Finland.
- Oulu Functional NeuroImaging, Diagnostic Radiology, Medical Research Center/HTS, Oulu University Hospital, 90029, Oulu, Finland.
| | - Mia Suhonen
- Medical Imaging, Physics and Technology, University of Oulu, 90029, Oulu, Finland.
- Oulu Functional NeuroImaging, Diagnostic Radiology, Medical Research Center/HTS, Oulu University Hospital, 90029, Oulu, Finland.
| | - Zalan Rajna
- Center for Machine Vision and Signal Analysis, University of Oulu, 90014, Oulu, Finland
| | - Youssef Hosni
- Center for Machine Vision and Signal Analysis, University of Oulu, 90014, Oulu, Finland
- Oulu Functional NeuroImaging, Diagnostic Radiology, Medical Research Center/HTS, Oulu University Hospital, 90029, Oulu, Finland
| | - Janne Kananen
- Medical Imaging, Physics and Technology, University of Oulu, 90029, Oulu, Finland
- Oulu Functional NeuroImaging, Diagnostic Radiology, Medical Research Center/HTS, Oulu University Hospital, 90029, Oulu, Finland
- Clinical Neurophysiology, Oulu University Hospital, 90029 OYS, Oulu, Finland
| | - Johanna Annunen
- Research Unit of Clinical Neuroscience, Neurology, University of Oulu, 90029, Oulu, Finland
- Neurocenter, Neurology, Oulu University Hospital, Member of ERN EpiCARE, 90029, Oulu, Finland
- MRC, Oulu University Hospital, 90029, Oulu, Finland
| | - Hanna Ansakorpi
- Research Unit of Clinical Neuroscience, Neurology, University of Oulu, 90029, Oulu, Finland
| | - Vesa Korhonen
- Medical Imaging, Physics and Technology, University of Oulu, 90029, Oulu, Finland
- Oulu Functional NeuroImaging, Diagnostic Radiology, Medical Research Center/HTS, Oulu University Hospital, 90029, Oulu, Finland
| | - Tapio Seppänen
- Center for Machine Vision and Signal Analysis, University of Oulu, 90014, Oulu, Finland
| | - Vesa Kiviniemi
- Medical Imaging, Physics and Technology, University of Oulu, 90029, Oulu, Finland.
| |
Collapse
|
11
|
Maurer-Morelli CV, de Vasconcellos JF, Bruxel EM, Rocha CS, do Canto AM, Tedeschi H, Yasuda CL, Cendes F, Lopes-Cendes I. Gene expression profile suggests different mechanisms underlying sporadic and familial mesial temporal lobe epilepsy. Exp Biol Med (Maywood) 2022; 247:2233-2250. [PMID: 36259630 PMCID: PMC9899983 DOI: 10.1177/15353702221126666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Most patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) have hippocampal sclerosis on the postoperative histopathological examination. Although most patients with MTLE do not refer to a family history of the disease, familial forms of MTLE have been reported. We studied surgical specimens from patients with MTLE who had epilepsy surgery for medically intractable seizures. We assessed and compared gene expression profiles of the tissue lesion found in patients with familial MTLE (n = 3) and sporadic MTLE (n = 5). In addition, we used data from control hippocampi obtained from a public database (n = 7). We obtained expression profiles using the Human Genome U133 Plus 2.0 (Affymetrix) microarray platform. Overall, the molecular profile identified in familial MTLE differed from that in sporadic MTLE. In the tissue of patients with familial MTLE, we found an over-representation of the biological pathways related to protein response, mRNA processing, and synaptic plasticity and function. In sporadic MTLE, the gene expression profile suggests that the inflammatory response is highly activated. In addition, we found enrichment of gene sets involved in inflammatory cytokines and mediators and chemokine receptor pathways in both groups. However, in sporadic MTLE, we also found enrichment of epidermal growth factor signaling, prostaglandin synthesis and regulation, and microglia pathogen phagocytosis pathways. Furthermore, based on the gene expression signatures, we identified different potential compounds to treat patients with familial and sporadic MTLE. To our knowledge, this is the first study assessing the mRNA profile in surgical tissue obtained from patients with familial MTLE and comparing it with sporadic MTLE. Our results clearly show that, despite phenotypic similarities, both forms of MTLE present distinct molecular signatures, thus suggesting different underlying molecular mechanisms that may require distinct therapeutic approaches.
Collapse
Affiliation(s)
- Claudia V Maurer-Morelli
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Jaira F de Vasconcellos
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Department of Biology, James Madison
University, Harrisonburg, VA 22807, USA
| | - Estela M Bruxel
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Cristiane S Rocha
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Amanda M do Canto
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil
| | - Helder Tedeschi
- Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Clarissa L Yasuda
- Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Fernando Cendes
- Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Department of Neurology, School of
Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-887, Brazil
| | - Iscia Lopes-Cendes
- Department of Translational Medicine,
School of Medical Sciences, University of Campinas (UNICAMP), Campinas 13083-888,
Brazil,Brazilian Institute of Neuroscience and
Neurotechnology (BRAINN), Campinas 13083-888, Brazil,Iscia Lopes-Cendes.
| |
Collapse
|
12
|
Hills KE, Kostarelos K, Wykes RC. Converging Mechanisms of Epileptogenesis and Their Insight in Glioblastoma. Front Mol Neurosci 2022; 15:903115. [PMID: 35832394 PMCID: PMC9271928 DOI: 10.3389/fnmol.2022.903115] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/25/2022] [Indexed: 12/15/2022] Open
Abstract
Glioblastoma (GBM) is the most common and advanced form of primary malignant tumor occurring in the adult central nervous system, and it is frequently associated with epilepsy, a debilitating comorbidity. Seizures are observed both pre- and post-surgical resection, indicating that several pathophysiological mechanisms are shared but also prompting questions about how the process of epileptogenesis evolves throughout GBM progression. Molecular mutations commonly seen in primary GBM, i.e., in PTEN and p53, and their associated downstream effects are known to influence seizure likelihood. Similarly, various intratumoral mechanisms, such as GBM-induced blood-brain barrier breakdown and glioma-immune cell interactions within the tumor microenvironment are also cited as contributing to network hyperexcitability. Substantial alterations to peri-tumoral glutamate and chloride transporter expressions, as well as widespread dysregulation of GABAergic signaling are known to confer increased epileptogenicity and excitotoxicity. The abnormal characteristics of GBM alter neuronal network function to result in metabolically vulnerable and hyperexcitable peri-tumoral tissue, properties the tumor then exploits to favor its own growth even post-resection. It is evident that there is a complex, dynamic interplay between GBM and epilepsy that promotes the progression of both pathologies. This interaction is only more complicated by the concomitant presence of spreading depolarization (SD). The spontaneous, high-frequency nature of GBM-associated epileptiform activity and SD-associated direct current (DC) shifts require technologies capable of recording brain signals over a wide bandwidth, presenting major challenges for comprehensive electrophysiological investigations. This review will initially provide a detailed examination of the underlying mechanisms that promote network hyperexcitability in GBM. We will then discuss how an investigation of these pathologies from a network level, and utilization of novel electrophysiological tools, will yield a more-effective, clinically-relevant understanding of GBM-related epileptogenesis. Further to this, we will evaluate the clinical relevance of current preclinical research and consider how future therapeutic advancements may impact the bidirectional relationship between GBM, SDs, and seizures.
Collapse
Affiliation(s)
- Kate E. Hills
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Kostas Kostarelos
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Catalan Institute for Nanoscience and Nanotechnology (ICN2), Edifici ICN2, Campus UAB, Barcelona, Spain
| | - Robert C. Wykes
- Nanomedicine Lab, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- *Correspondence: Robert C. Wykes
| |
Collapse
|
13
|
Szu JI, Binder DK. Mechanisms Underlying Aquaporin-4 Subcellular Mislocalization in Epilepsy. Front Cell Neurosci 2022; 16:900588. [PMID: 35734218 PMCID: PMC9207308 DOI: 10.3389/fncel.2022.900588] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Epilepsy is a chronic brain disorder characterized by unprovoked seizures. Mechanisms underlying seizure activity have been intensely investigated. Alterations in astrocytic channels and transporters have shown to be a critical player in seizure generation and epileptogenesis. One key protein involved in such processes is the astrocyte water channel aquaporin-4 (AQP4). Studies have revealed that perivascular AQP4 redistributes away from astrocyte endfeet and toward the neuropil in both clinical and preclinical studies. This subcellular mislocalization significantly impacts neuronal hyperexcitability and understanding how AQP4 becomes dysregulated in epilepsy is beginning to emerge. In this review, we evaluate the role of AQP4 dysregulation and mislocalization in epilepsy.
Collapse
|
14
|
Skauli N, Savchenko E, Ottersen OP, Roybon L, Amiry-Moghaddam M. Canonical Bone Morphogenetic Protein Signaling Regulates Expression of Aquaporin-4 and Its Anchoring Complex in Mouse Astrocytes. Front Cell Neurosci 2022; 16:878154. [PMID: 35518645 PMCID: PMC9067306 DOI: 10.3389/fncel.2022.878154] [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: 02/17/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Aquaporin-4 (AQP4) is the predominant water channel in the brain; it is enriched in astrocytic foot processes abutting vessels where it is anchored through an interaction with the dystrophin-associated protein (DAP) complex. Enhanced expression with concomitant mislocalization of AQP4 along astrocyte plasma membranes is a hallmark of several neurological conditions. Thus, there is an urgent need to identify which signaling pathways dictate AQP4 microdistribution. Here we show that canonical bone morphogenetic proteins (BMPs), particularly BMP2 and 4, upregulate AQP4 expression in astrocytes and dysregulate the associated DAP complex by differentially affecting its individual members. We further demonstrate the presence of BMP receptors and Smad1/5/9 pathway activation in BMP treated astrocytes. Our analysis of adult mouse brain reveals BMP2 and 4 in neurons and in a subclass of endothelial cells and activated Smad1/5/9 in astrocytes. We conclude that the canonical BMP-signaling pathway might be responsible for regulating the expression of AQP4 and of DAP complex proteins that govern the subcellular compartmentation of this aquaporin.
Collapse
Affiliation(s)
- Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ekaterina Savchenko
- Stem Cell Laboratory for CNS Disease Modeling, Department of Experimental Medical Science, BMC D10, Lund University, Lund, Sweden
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Karolinska Institutet, Stockholm, Sweden
| | - Laurent Roybon
- Stem Cell Laboratory for CNS Disease Modeling, Department of Experimental Medical Science, BMC D10, Lund University, Lund, Sweden
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
15
|
Wagner K, Unger L, Salman MM, Kitchen P, Bill RM, Yool AJ. Signaling Mechanisms and Pharmacological Modulators Governing Diverse Aquaporin Functions in Human Health and Disease. Int J Mol Sci 2022; 23:1388. [PMID: 35163313 PMCID: PMC8836214 DOI: 10.3390/ijms23031388] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 02/07/2023] Open
Abstract
The aquaporins (AQPs) are a family of small integral membrane proteins that facilitate the bidirectional transport of water across biological membranes in response to osmotic pressure gradients as well as enable the transmembrane diffusion of small neutral solutes (such as urea, glycerol, and hydrogen peroxide) and ions. AQPs are expressed throughout the human body. Here, we review their key roles in fluid homeostasis, glandular secretions, signal transduction and sensation, barrier function, immunity and inflammation, cell migration, and angiogenesis. Evidence from a wide variety of studies now supports a view of the functions of AQPs being much more complex than simply mediating the passive flow of water across biological membranes. The discovery and development of small-molecule AQP inhibitors for research use and therapeutic development will lead to new insights into the basic biology of and novel treatments for the wide range of AQP-associated disorders.
Collapse
Affiliation(s)
- Kim Wagner
- School of Biomedicine, University of Adelaide, Adelaide, SA 5005, Australia;
| | - Lucas Unger
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK; (L.U.); (P.K.)
| | - Mootaz M. Salman
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK;
- Oxford Parkinson’s Disease Centre, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Philip Kitchen
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK; (L.U.); (P.K.)
| | - Roslyn M. Bill
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK; (L.U.); (P.K.)
| | - Andrea J. Yool
- School of Biomedicine, University of Adelaide, Adelaide, SA 5005, Australia;
| |
Collapse
|
16
|
Szczygielski J, Kopańska M, Wysocka A, Oertel J. Cerebral Microcirculation, Perivascular Unit, and Glymphatic System: Role of Aquaporin-4 as the Gatekeeper for Water Homeostasis. Front Neurol 2021; 12:767470. [PMID: 34966347 PMCID: PMC8710539 DOI: 10.3389/fneur.2021.767470] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/12/2021] [Indexed: 12/13/2022] Open
Abstract
In the past, water homeostasis of the brain was understood as a certain quantitative equilibrium of water content between intravascular, interstitial, and intracellular spaces governed mostly by hydrostatic effects i.e., strictly by physical laws. The recent achievements in molecular bioscience have led to substantial changes in this regard. Some new concepts elaborate the idea that all compartments involved in cerebral fluid homeostasis create a functional continuum with an active and precise regulation of fluid exchange between them rather than only serving as separate fluid receptacles with mere passive diffusion mechanisms, based on hydrostatic pressure. According to these concepts, aquaporin-4 (AQP4) plays the central role in cerebral fluid homeostasis, acting as a water channel protein. The AQP4 not only enables water permeability through the blood-brain barrier but also regulates water exchange between perivascular spaces and the rest of the glymphatic system, described as pan-cerebral fluid pathway interlacing macroscopic cerebrospinal fluid (CSF) spaces with the interstitial fluid of brain tissue. With regards to this, AQP4 makes water shift strongly dependent on active processes including changes in cerebral microcirculation and autoregulation of brain vessels capacity. In this paper, the role of the AQP4 as the gatekeeper, regulating the water exchange between intracellular space, glymphatic system (including the so-called neurovascular units), and intravascular compartment is reviewed. In addition, the new concepts of brain edema as a misbalance in water homeostasis are critically appraised based on the newly described role of AQP4 for fluid permeation. Finally, the relevance of these hypotheses for clinical conditions (including brain trauma and stroke) and for both new and old therapy concepts are analyzed.
Collapse
Affiliation(s)
- Jacek Szczygielski
- Department of Neurosurgery, Institute of Medical Sciences, University of Rzeszów, Rzeszów, Poland.,Department of Neurosurgery, Faculty of Medicine and Saarland University Medical Center, Saarland University, Homburg, Germany
| | - Marta Kopańska
- Department of Pathophysiology, Institute of Medical Sciences, University of Rzeszów, Rzeszów, Poland
| | - Anna Wysocka
- Chair of Internal Medicine and Department of Internal Medicine in Nursing, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
| | - Joachim Oertel
- Department of Neurosurgery, Faculty of Medicine and Saarland University Medical Center, Saarland University, Homburg, Germany
| |
Collapse
|
17
|
Twible C, Abdo R, Zhang Q. Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting. Front Cell Neurosci 2021; 15:725693. [PMID: 34658792 PMCID: PMC8514632 DOI: 10.3389/fncel.2021.725693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.
Collapse
Affiliation(s)
- Carolyn Twible
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada
| | - Rober Abdo
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Anatomy and Cell Biology, Western University, London, ON, Canada
| | - Qi Zhang
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Pathology and Lab Medicine, London Health Sciences Centre, University Hospital, London, ON, Canada
| |
Collapse
|
18
|
Urushihata T, Takuwa H, Takahashi M, Kershaw J, Tachibana Y, Nitta N, Shibata S, Yasui M, Higuchi M, Obata T. Exploring cell membrane water exchange in aquaporin-4-deficient ischemic mouse brain using diffusion-weighted MRI. Eur Radiol Exp 2021; 5:44. [PMID: 34617156 PMCID: PMC8494869 DOI: 10.1186/s41747-021-00244-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Aquaporin-4 is a membrane channel protein that is highly expressed in brain astrocytes and facilitates the transport of water molecules. It has been suggested that suppression of aquaporin-4 function may be an effective treatment for reducing cellular edema after cerebral infarction. It is therefore important to develop clinically applicable measurement systems to evaluate and better understand the effects of aquaporin-4 suppression on the living body. METHODS Animal models of focal cerebral ischemia were created by surgically occluding the middle cerebral artery of wild-type and aquaporin-4 knockout mice, after which multi-b-value multi-diffusion-time diffusion-weighted imaging measurements were performed. Data were analyzed with both the apparent diffusion coefficient (ADC) model and a compartmental water-exchange model. RESULTS ADCs were estimated for five different b value ranges. The ADC of aquaporin-4 knockout mice in the contralateral region was significantly higher than that of wild-type mice for each range. In contrast, aquaporin-4 knockout mice had significantly lower ADC than wild-type mice in ischemic tissue for each b-value range. Genotype-dependent differences in the ADC were particularly significant for the lowest ranges in normal tissue and for the highest ranges in ischemic tissue. The ADCs measured at different diffusion times were significantly different for both genotypes. Fitting of the water-exchange model to the ischemic region data found that the water-exchange time in aquaporin-4 knockout mice was approximately 2.5 times longer than that in wild-type mice. CONCLUSIONS Multi-b-value multi-diffusion-time diffusion-weighted imaging may be useful for in vivo research and clinical diagnosis of aquaporin-4-related diseases.
Collapse
Affiliation(s)
- Takuya Urushihata
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Hiroyuki Takuwa
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Manami Takahashi
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Jeff Kershaw
- Applied MRI Research, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Yasuhiko Tachibana
- Applied MRI Research, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Nobuhiro Nitta
- Applied MRI Research, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Sayaka Shibata
- Applied MRI Research, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Masato Yasui
- Keio Advanced Research Center for Water Biology and Medicine, Keio University, Tokyo, 160-0016, Japan
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan
| | - Takayuki Obata
- Applied MRI Research, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, QST, Chiba, 263-8555, Japan.
| |
Collapse
|
19
|
Kyriatzis G, Bernard A, Bôle A, Pflieger G, Chalas P, Masse M, Lécorché P, Jacquot G, Ferhat L, Khrestchatisky M. Neurotensin receptor 2 is induced in astrocytes and brain endothelial cells in relation to neuroinflammation following pilocarpine-induced seizures in rats. Glia 2021; 69:2618-2643. [PMID: 34310753 DOI: 10.1002/glia.24062] [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: 06/30/2020] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 12/14/2022]
Abstract
Neurotensin (NT) acts as a primary neurotransmitter and neuromodulator in the CNS and has been involved in a number of CNS pathologies including epilepsy. NT mediates its central and peripheral effects by interacting with the NTSR1, NTSR2, and Sort1/NTSR3 receptor subtypes. To date, little is known about the precise expression of the NT receptors in brain neural cells and their regulation in pathology. In the present work, we studied the cellular distribution of the NTSR2 protein in the rat hippocampus and questioned whether its expression was modulated in conditions of neuroinflammation using a model of temporal lobe epilepsy induced by pilocarpine. This model is characterized by a rapid and intense inflammatory reaction with reactive gliosis in the hippocampus. We show that NTSR2 protein is expressed in hippocampal astrocytes and its expression increases together with astrocyte reactivity following induction of status epilepticus. NTSR2 immunoreactivity is also increased in astrocytes proximal to blood vessels and their end-feet, and in endothelial cells. Proinflammatory factors such as IL1β and LPS induced NTSR2 mRNA and protein in cultured astroglial cells. Antagonizing NTSR2 with SR142948A decreased NTSR2 expression as well as astroglial reactivity. Together, our results suggest that NTSR2 is implicated in astroglial and gliovascular inflammation and that targeting the NTSR2 receptor may open new avenues in the regulation of neuroinflammation in CNS diseases.
Collapse
Affiliation(s)
- Grigorios Kyriatzis
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Anne Bernard
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Angélique Bôle
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Guillaume Pflieger
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Petros Chalas
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Maxime Masse
- VECT-HORUS, Faculté de Médecine, Marseille Cedex, France
| | | | | | - Lotfi Ferhat
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| | - Michel Khrestchatisky
- Aix-Marseille University, CNRS, INP, Institute of NeuroPhysiopathology, Marseille Cedex, France
| |
Collapse
|
20
|
Binder DK, Steinhäuser C. Astrocytes and Epilepsy. Neurochem Res 2021; 46:2687-2695. [PMID: 33661442 DOI: 10.1007/s11064-021-03236-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/12/2022]
Abstract
Changes in astrocyte channels, transporters, and metabolism play a critical role in seizure generation and epilepsy. In particular, alterations in astrocyte potassium, glutamate, water and adenosine homeostasis and gap junctional coupling have all been associated with hyperexcitability and epileptogenesis (largely in temporal lobe epilepsy). Distinct astrocytic changes have also been identified in other types of epilepsy, such as tuberous sclerosis, tumor-associated epilepsy and post-traumatic epilepsy. Together, the emerging literature on astrocytes and epilepsy provides powerful rationale for distinct new therapeutic targets that are astrocyte-specific.
Collapse
Affiliation(s)
- Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA.
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| |
Collapse
|
21
|
Lapato AS, Thompson SM, Parra K, Tiwari-Woodruff SK. Astrocyte Glutamate Uptake and Water Homeostasis Are Dysregulated in the Hippocampus of Multiple Sclerosis Patients With Seizures. ASN Neuro 2020; 12:1759091420979604. [PMID: 33297722 PMCID: PMC7734542 DOI: 10.1177/1759091420979604] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
While seizure disorders are more prevalent among multiple sclerosis (MS) patients than the population overall and prognosticate earlier death & disability, their etiology remains unclear. Translational data indicate perturbed expression of astrocytic molecules contributing to homeostatic neuronal excitability, including water channels (AQP4) and synaptic glutamate transporters (EAAT2), in a mouse model of MS with seizures (MS+S). However, astrocytes in MS+S have not been examined. To assess the translational relevance of astrocyte dysfunction observed in a mouse model of MS+S, demyelinated lesion burden, astrogliosis, and astrocytic biomarkers (AQP4/EAAT2/ connexin-CX43) were evaluated by immunohistochemistry in postmortem hippocampi from MS & MS+S donors. Lesion burden was comparable in MS & MS+S cohorts, but astrogliosis was elevated in MS+S CA1 with a concomitant decrease in EAAT2 signal intensity. AQP4 signal declined in MS+S CA1 & CA3 with a loss of perivascular AQP4 in CA1. CX43 expression was increased in CA3. Together, these data suggest that hippocampal astrocytes from MS+S patients display regional differences in expression of molecules associated with glutamate buffering and water homeostasis that could exacerbate neuronal hyperexcitability. Importantly, mislocalization of CA1 perivascular AQP4 seen in MS+S is analogous to epileptic hippocampi without a history of MS, suggesting convergent pathophysiology. Furthermore, as neuropathology was concentrated in MS+S CA1, future study is warranted to determine the pathophysiology driving regional differences in glial function in the context of seizures during demyelinating disease.
Collapse
Affiliation(s)
- Andrew S Lapato
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States.,Center for Glial-Neuronal Interaction, UCR School of Medicine, Riverside, California, United States
| | - Sarah M Thompson
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States
| | - Karen Parra
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, UCR School of Medicine, Riverside, California, United States.,Center for Glial-Neuronal Interaction, UCR School of Medicine, Riverside, California, United States.,Department of Neuroscience, UCR School of Medicine, Riverside, California, United States
| |
Collapse
|
22
|
Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
Collapse
Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
23
|
Gene expression in the epileptic (EL) mouse hippocampus. Neurobiol Dis 2020; 147:105152. [PMID: 33153970 DOI: 10.1016/j.nbd.2020.105152] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/07/2020] [Accepted: 10/23/2020] [Indexed: 11/24/2022] Open
Abstract
The neuropathology of hippocampal seizure foci in human temporal lobe epilepsy (TLE) and several animal models of epilepsy reveal extensive neuronal loss along with astrocyte and microglial activation. Studies of these models have advanced hypotheses that propose both pathological changes are essential for seizure generation. However, some seizure foci in human TLE show an extreme loss of neurons in all hippocampal fields, giving weight to hypotheses that favor neuroglia as major players. The epileptic (EL) mouse is a seizure model in which there is no observable neuron loss but associated proliferation of microglia and astrocytes and provides a good model to study the role of activated neuroglia in the presence of an apparently normal population of neurons. While many studies have been carried out on the EL mouse, there is a paucity of studies on the molecular changes in the EL mouse hippocampus, which may provide insight on the role of neuroglia in epileptogenesis. In this paper we have applied high throughput gene expression analysis to identify the molecular changes in the hippocampus that may explain the pathological processes. We have observed several classes of genes whose expression levels are changed. It is hypothesized that the upregulation of heat shock proteins (HSP70, HSP72, FOSL2 (HSP40), and their molecular chaperones BAG3 and DNAJB5 along with the down regulated gene MALAT1 may contribute to the neuroprotection observed. The increased expression of BDNF along with immediate early gene expression (FosB, JunB, ERG4, NR4A1, NR4A2, FBXO3) and the down regulation of GABRD, DBP and MALAT1 it is hypothesized may contribute to the hyperexcitability of the hippocampal neurons in this model. Activated astrocytes and microglia may also contribute to excitability pathomechanisms. Activated astrocytes in the ELS mouse are deficient in glutamine synthetase and thus reduce the clearance of extracellular glutamate. Activated microglia which may be associated with C1Q and MHC class I molecules we propose may mediate a process of selective removal of defective GABAergic synapses through a process akin to trogocytosis that may reduce neuronal inhibition and favor hyperexcitability.
Collapse
|
24
|
Stevenson R, Samokhina E, Rossetti I, Morley JW, Buskila Y. Neuromodulation of Glial Function During Neurodegeneration. Front Cell Neurosci 2020; 14:278. [PMID: 32973460 PMCID: PMC7473408 DOI: 10.3389/fncel.2020.00278] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
Glia, a non-excitable cell type once considered merely as the connective tissue between neurons, is nowadays acknowledged for its essential contribution to multiple physiological processes including learning, memory formation, excitability, synaptic plasticity, ion homeostasis, and energy metabolism. Moreover, as glia are key players in the brain immune system and provide structural and nutritional support for neurons, they are intimately involved in multiple neurological disorders. Recent advances have demonstrated that glial cells, specifically microglia and astroglia, are involved in several neurodegenerative diseases including Amyotrophic lateral sclerosis (ALS), Epilepsy, Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal dementia (FTD). While there is compelling evidence for glial modulation of synaptic formation and regulation that affect neuronal signal processing and activity, in this manuscript we will review recent findings on neuronal activity that affect glial function, specifically during neurodegenerative disorders. We will discuss the nature of each glial malfunction, its specificity to each disorder, overall contribution to the disease progression and assess its potential as a future therapeutic target.
Collapse
Affiliation(s)
- Rebecca Stevenson
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Evgeniia Samokhina
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Ilaria Rossetti
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - John W. Morley
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- International Centre for Neuromorphic Systems, The MARCS Institute for Brain, Behaviour and Development, Penrith, NSW, Australia
| |
Collapse
|
25
|
Szu JI, Patel DD, Chaturvedi S, Lovelace JW, Binder DK. Modulation of posttraumatic epileptogenesis in aquaporin-4 knockout mice. Epilepsia 2020; 61:1503-1514. [PMID: 32484924 DOI: 10.1111/epi.16551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 05/05/2020] [Accepted: 05/05/2020] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine the role of aquaporin-4 (AQP4) in posttraumatic epileptogenesis using long-term video-electroencephalographic (vEEG) recordings. Here, differences in EEG were analyzed between wild-type (WT) and AQP4 knockout (KO) mice and between mice with and without posttraumatic epilepsy (PTE). METHODS WT and AQP4 KO mice were subjected to a single controlled cortical impact traumatic brain injury (TBI) in the frontal cortex, and vEEG was recorded in the ipsilateral hippocampus at 14, 30, 60, and 90 days postinjury (dpi). Intrahippocampal electrical stimulation was also used to assess electrographic seizure threshold and electrographic seizure duration (ESD). RESULTS The mean seizure frequency per day for WT mice was 0.07 ± 0.07, 0.11 ± 0.07, 0.26 ± 0.13, and 0.12 ± 0.10 at 14, 30, 60, and 90 dpi, respectively. The mean seizure frequency per day for AQP4 KO mice was 0.45 ± 0.27, 0.29 ± 0.12, and 0.26 ± 0.19 at 14, 30, and 60 dpi, respectively. The mean seizure duration was 15 ± 2 seconds and 24 ± 3 seconds for WT and AQP4 KO mice, respectively. The percentage of mice that developed PTE were 28% and 37% for WT and AQP4 KO mice, respectively. Power spectral density (PSD) analysis revealed alterations in EEG frequency bands between sham and TBI in both genotypes. Additionally, PSD analysis of spontaneous recurrent seizures revealed alterations in delta power between genotypes. Morlet wavelet analysis detected heterogeneity in EEG seizure subtypes and dynamic EEG power patterns after TBI. Compared with AQP4 KO mice, a significant increase in ESD was observed in WT mice at 14 dpi. SIGNIFICANCE Posttraumatic seizures (PTSs) may be modulated by the astrocyte water channel AQP4. Absence of AQP4 increases the number of spontaneous seizures, increases seizure duration, and alters EEG power patterns of PTSs.
Collapse
Affiliation(s)
- Jenny I Szu
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Dillon D Patel
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Som Chaturvedi
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Jonathan W Lovelace
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| |
Collapse
|
26
|
Dasdelen D, Mogulkoc R, Baltaci AK. Aquaporins and Roles in Brain Health and Brain Injury. Mini Rev Med Chem 2020; 20:498-512. [DOI: 10.2174/1389557519666191018142007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 05/07/2019] [Accepted: 10/03/2019] [Indexed: 02/08/2023]
Abstract
In the literature screening, aquaporins were found in the cerebral structures including the pia mater, choroid plexus, ependyma, piriform cortex, hippocampus, dorsal thalamus, supraoptic and suprachiasmatic nuclei, white matter and subcortical organ. Among these, the most common are AQP1, AQP4, and AQP9. The roles of aquaporins have been demonstrated in several diseases such as cerebral edema, various central nervous system tumors, Alzheimer’s Disease and epilepsy. In this review, the relationship between brain/brain-injury and aquaporin, has been reviewed.
Collapse
Affiliation(s)
- Dervis Dasdelen
- Department of Physiology, Medical Faculty, Selcuk University, Konya, Turkey
| | - Rasim Mogulkoc
- Department of Physiology, Medical Faculty, Selcuk University, Konya, Turkey
| | | |
Collapse
|
27
|
Shchepareva ME, Zakharova MN. Functional Role of Aquaporins in the Nervous System under Normal and Pathological Conditions. NEUROCHEM J+ 2020. [DOI: 10.1134/s1819712420010171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
28
|
Hippocampal synaptic and membrane function in the DBA/2J-mdx mouse model of Duchenne muscular dystrophy. Mol Cell Neurosci 2020; 104:103482. [PMID: 32171922 DOI: 10.1016/j.mcn.2020.103482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Dystrophin deficiency is associated with alterations in cell physiology. The functional consequences of dystrophin deficiency are particularly severe for muscle physiology, as observed in Duchenne muscle dystrophy (DMD). DMD is caused by the absence of a 427 kDa isoform of dystrophin. However, in addition to muscular dystrophy symptoms, DMD is frequently associated with memory and attention deficits and epilepsy. While this may be associated with a role for dystrophin in neuronal physiology, it is not clear what neuronal alterations are linked with DMD. Our work shows that CA1 pyramidal neurons from DBA/2J-mdx mice have increased afterhyperpolarization compared to WT controls. All the other electrotonic and electrogenic membrane properties were unaffected by this genotype. Finally, basal synaptic transmission, short-term and long-term synaptic plasticity at Schaffer collateral to CA1 glutamatergic synapses were unchanged between mdx and WT controls. These data show that the excitatory component of hippocampal activity is largely preserved in DBA/2J-mdx mice. Further studies, extending the investigation to the inhibitory GABAergic function, may provide a more complete picture of the functional, network alterations underlying impaired cognition in DMD. In addition, the investigation of changes in neuronal single conductance biophysical properties associated with this genotype, is required to identify the functional alterations associated with dystrophin deficiency and clarify its role in neuronal function.
Collapse
|
29
|
Szu JI, Chaturvedi S, Patel DD, Binder DK. Aquaporin-4 Dysregulation in a Controlled Cortical Impact Injury Model of Posttraumatic Epilepsy. Neuroscience 2019; 428:140-153. [PMID: 31866558 DOI: 10.1016/j.neuroscience.2019.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/25/2019] [Accepted: 12/03/2019] [Indexed: 11/15/2022]
Abstract
Posttraumatic epilepsy (PTE) is a long-term negative consequence of traumatic brain injury (TBI) in which recurrent spontaneous seizures occur after the initial head injury. PTE develops over an undefined period during which circuitry reorganization in the brain causes permanent hyperexcitability. The pathophysiology by which trauma leads to spontaneous seizures is unknown and clinically relevant models of PTE are key to understanding the molecular and cellular mechanisms underlying the development of PTE. In the present study, we used the controlled-cortical impact (CCI) injury model of TBI to induce PTE in mice and to characterize changes in aquaporin-4 (AQP4) expression. A moderate-severe TBI was induced in the right frontal cortex and video-electroencephalographic (vEEG) recordings were performed in the ipsilateral hippocampus to monitor for spontaneous seizures at 14, 30, 60, and 90 days post injury (dpi). The percentage of mice that developed PTE were 13%, 20%, 27%, and 14% at 14, 30, 60, and 90 dpi, respectively. We found a significant increase in AQP4 in the ipsilateral frontal cortex and hippocampus of mice that developed PTE compared to those that did not develop PTE. Interestingly, AQP4 was found to be mislocalized away from the perivascular endfeet and towards the neuropil in mice that developed PTE. Here, we report for the first time, AQP4 dysregulation in a model of PTE which may carry significant implications for epileptogenesis after TBI.
Collapse
Affiliation(s)
- Jenny I Szu
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Som Chaturvedi
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Dillon D Patel
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA.
| |
Collapse
|
30
|
Eid T, Lee TSW, Patrylo P, Zaveri HP. Astrocytes and Glutamine Synthetase in Epileptogenesis. J Neurosci Res 2019; 97:1345-1362. [PMID: 30022509 PMCID: PMC6338538 DOI: 10.1002/jnr.24267] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/15/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022]
Abstract
The cellular, molecular, and metabolic mechanisms that underlie the development of mesial temporal lobe epilepsy are incompletely understood. Here we review the role of astrocytes in epilepsy development (a.k.a. epileptogenesis), particularly astrocyte pathologies related to: aquaporin 4, the inwardly rectifying potassium channel Kir4.1, monocarboxylate transporters MCT1 and MCT2, excitatory amino acid transporters EAAT1 and EAAT2, and glutamine synthetase. We propose that inhibition, dysfunction or loss of astrocytic glutamine synthetase is an important causative factor for some epilepsies, particularly mesial temporal lobe epilepsy and glioblastoma-associated epilepsy. We postulate that the regulatory mechanisms of glutamine synthetase as well as the downstream effects of glutamine synthetase dysfunction, represent attractive, new targets for antiepileptogenic interventions. Currently, no antiepileptogenic therapies are available for human use. The discovery of such interventions is important as it will fundamentally change the way we approach epilepsy by preventing the disease from ever becoming manifest after an epileptogenic insult to the brain.
Collapse
Affiliation(s)
- Tore Eid
- Department of Laboratory Medicine, Yale School of Medicine
- Department of Molecular Medicine, University of Oslo
| | | | - Peter Patrylo
- Department of Physiology, Southern Illinois University School of Medicine
| | | |
Collapse
|
31
|
Subaraja M, Kulandaisamy A, Shanmugam NRS, Vanisree AJ. Homology modeling identified for purported drug targets to the neuroprotective effects of levodopa and asiaticoside-D in degenerated cerebral ganglions of Lumbricus terrestris. Indian J Pharmacol 2019; 51:31-39. [PMID: 31031465 PMCID: PMC6444839 DOI: 10.4103/ijp.ijp_600_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CONTEXT: Homology modeling plays role in determining the therapeutic targets dreadful for condition such as neurodegenerative diseases (NDD), which pose challenge in achieving the effective managements. The structures of the serotonin transporter (SERT), aquaporin (AQP), and tropomyosin receptor kinase (TrkA) which are implicated in NDD pathology are still unknown for Lumbricus terrestris, but the three-dimensional (3D) structure of the human counterpart for modeling. AIM: This study aims to generate and evaluate the 3D structure of TrkA, SERT, and AQP proteins and their interaction with the ligands, namely Asiaticoside-D (AD) and levodopa (L-DOPA) the anti-NDD agents. SUBJECTS AND METHODS: Homology modeling for SERT, AQP, and TrkA proteins of Lumbricus terrestris using SWISS-MODEL Server and the modeled structure was validated using Rampage Server. Wet-lab analysis of their correspondent m-RNA levels was also done to validate the in silico data. RESULTS: It was found that TrkA had moderately high homology (67%) to human while SERT and AQP could exhibit 58% and 42%, respectively. The reliability of the model was assessed by Ramachandran plot analysis. Interactions of AD with the SERT, AQP-4, and TrkA showed the binding energies as −9.93, 8.88, and −7.58 of Kcal/mol, respectively, while for L-DOPA did show −3.93, −5.13, and −6.0 Kcal/mol, respectively. The levels of SERT, TrkA, and AQP-4 were significantly reduced (P < 0.001) on ROT induced when compared to those of control worms. On ROT + AD supplementation group (III), m-RNA levels were significantly increased (P < 0.05) when compared to those of ROT induced worms (group II). CONCLUSION: Our pioneering docking data propose the possible of target which is proved useful for therapeutic investigations against the unconquered better of NDD.
Collapse
Affiliation(s)
- Mamangam Subaraja
- Department of Biochemistry, Guindy Campus, University of Madras, Chennai, Tamil Nadu, India
| | - A Kulandaisamy
- Department of Biotechnology, Indian Institute of Technology, Chennai, Tamil Nadu, India
| | - N R Siva Shanmugam
- Department of Biotechnology, Indian Institute of Technology, Chennai, Tamil Nadu, India
| | | |
Collapse
|
32
|
Aquaporin-4 Water Channel in the Brain and Its Implication for Health and Disease. Cells 2019; 8:cells8020090. [PMID: 30691235 PMCID: PMC6406241 DOI: 10.3390/cells8020090] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 02/08/2023] Open
Abstract
Aquaporin-4 (AQP4) is a water channel expressed on astrocytic endfeet in the brain. The role of AQP4 has been studied in health and in a range of pathological conditions. Interest in AQP4 has increased since it was discovered to be the target antigen in the inflammatory autoimmune disease neuromyelitis optica spectrum disorder (NMOSD). Emerging data suggest that AQP4 may also be implicated in the glymphatic system and may be involved in the clearance of beta-amyloid in Alzheimer’s disease (AD). In this review, we will describe the role of AQP4 in the adult and developing brain as well as its implication for disease.
Collapse
|
33
|
Skowrońska K, Obara-Michlewska M, Czarnecka A, Dąbrowska K, Zielińska M, Albrecht J. Persistent Overexposure to N-Methyl-D-Aspartate (NMDA) Calcium-Dependently Downregulates Glutamine Synthetase, Aquaporin 4, and Kir4.1 Channel in Mouse Cortical Astrocytes. Neurotox Res 2018; 35:271-280. [PMID: 30220059 PMCID: PMC6313349 DOI: 10.1007/s12640-018-9958-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 08/31/2018] [Accepted: 09/07/2018] [Indexed: 11/25/2022]
Abstract
Astrocytes express N-methyl-d-aspartate (NMDA) receptor (NMDAR) but its functions in these cells are not well defined. This study shows that the sustained exposure (8–72 h) of mouse astrocytes to NMDA decreases the expression of the functional astroglia-specific proteins, glutamine synthetase (GS), and the water channel protein aquaporin-4 (AQP4) and also reduces GS activity. Similar to rat astrocytes (Obara-Michlewska et al. Neurochem Int 88:20–25, 2015), the exposure of mouse astrocytes to NMDA also decreased the expression of the inward rectifying potassium channel Kir4.1. NMDA failed to elicit the effects in those cells incubated in the absence of Ca2+ and in those in which the GluN1 subunit of the NMDAR was silenced with GluN1 siRNA. The downregulation of GS, AQP4, and Kir4.1 observed in vitro may reflect NMDAR-mediated alterations of astrocytic functions noted in central nervous system pathologies associated with increased glutamate (Glu) release and excitotoxic tissue damage.
Collapse
Affiliation(s)
- Katarzyna Skowrońska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Marta Obara-Michlewska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Anna Czarnecka
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Katarzyna Dąbrowska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland
| | - Jan Albrecht
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego St. 5, 02-106, Warsaw, Poland.
| |
Collapse
|
34
|
|
35
|
Hirt L, Price M, Benakis C, Badaut J. Aquaporins in neurological disorders. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2018. [DOI: 10.1177/2514183x17752902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Lorenz Hirt
- Neurology service, department of clinical neurosciences, CHUV, Lausanne, Switzerland
- Centre de recherche en neurosciences (CRN), CHUV, Lausanne, Switzerland
| | - Melanie Price
- Neurology service, department of clinical neurosciences, CHUV, Lausanne, Switzerland
- Centre de recherche en neurosciences (CRN), CHUV, Lausanne, Switzerland
| | - Corinne Benakis
- Institute for Stroke and Dementia Research (ISD), Munich, Germany
| | - Jérôme Badaut
- CNRS UMR 5287, INCIA, University of Bordeaux, Bordeaux, France
- Department of Basic science, Loma Linda University, Loma Linda, CA, USA
| |
Collapse
|
36
|
Changes in the Expression of AQP4 and AQP9 in the Hippocampus Following Eclampsia-Like Seizure. Int J Mol Sci 2018; 19:ijms19010300. [PMID: 29351212 PMCID: PMC5796245 DOI: 10.3390/ijms19010300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/24/2017] [Accepted: 12/04/2017] [Indexed: 01/01/2023] Open
Abstract
Eclampsia is a hypertensive disorder of pregnancy that is defined by the new onset of grand mal seizures on the basis of pre-eclampsia. Until now, the mechanisms underlying eclampsia were poorly understood. Brain edema is considered a leading cause of eclamptic seizures; aquaporins (AQP4 and AQP9), the glial water channel proteins mainly expressed in the nervous system, play an important role in brain edema. We studied AQP4 and AQP9 expression in the hippocampus of pre-eclamptic and eclamptic rats in order to explore the molecular mechanisms involved in brain edema. Using our previous animal models, we found several neuronal deaths in the hippocampal CA1 and CA3 regions after pre-eclampsia and that eclampsia induced more neuronal deaths in both areas by Nissl staining. In the current study, RT-PCR and Western blotting data showed significant upregulation of AQP4 and AQP9 mRNA and protein levels after eclamptic seizures in comparison to pre-eclampsia and at the same time AQP4 and AQP9 immunoreactivity also increased after eclampsia. These findings showed that eclamptic seizures induced cell death and that upregulation of AQP4 and AQP9 may play an important role in this pathophysiological process.
Collapse
|
37
|
Hattingen E, Enkirch SJ, Jurcoane A, Kruse M, Delev D, Grote A, Becker A. Hippocampal "gliosis only" on MR imaging represents a distinct entity in epilepsy patients. Neuroradiology 2017; 60:161-168. [PMID: 29085967 DOI: 10.1007/s00234-017-1939-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE The purpose of this study is to evaluate whether patients with drug-resistant mesial temporal lobe epilepsy (TLE) due to hippocampal "gliosis only" have different MRI features than those with hippocampal sclerosis (HS). Most TLE patients have HS corresponding to severe neuronal loss and gliosis, but a few have "gliosis only" without significant reduction of neuronal density. METHODS We analyzed the morphology of cerebral 3 T MRIs (T1, T2, and FLAIR) of 103 patients with HS and 20 with "gliosis only" concerning hippocampal and amygdala aspect, volumes, and signal intensity (SI) using Fisher's exact test, Student's t test, and principal component analysis. RESULTS Visually, the ipsilateral hippocampus was hyperintense in both groups, but SI was markedly increased in 74% of HS and in 25% of "gliosis only" patients; the ipsilateral hippocampus was smaller in 92% of HS and in 50% of "gliosis only" patients, and its internal architecture was lost in 57% of HS and 5% of "gliosis only" patients; the contralateral hippocampal SI was altered in 25% of HS and in 70% of "gliosis only" patients (all p < 0.001). Ipsilateral hippocampus of HS patients had lower volume (mean ± SD 2.86 ± 0.87 ml) compared with that of "gliosis only" patients (3.4 ± 1.02 ml) and had higher SI than the contralateral hippocampus of HS patients and then the hippocampus of "gliosis only" patients (all p < 0.01). CONCLUSION "Gliosis only" has different MRI hippocampal characteristics than HS: less volume loss, less increase of the T2-w signal intensity, preservation of internal architecture, and more contralateral affection.
Collapse
Affiliation(s)
- Elke Hattingen
- Neuroradiology, Department of Radiology, University Clinics Bonn, Sigmund Freud Str. 25, 53105, Bonn, Germany.
| | - Simon Jonas Enkirch
- Neuroradiology, Department of Radiology, University Clinics Bonn, Sigmund Freud Str. 25, 53105, Bonn, Germany
| | - Alina Jurcoane
- Neuroradiology, Department of Radiology, University Clinics Bonn, Sigmund Freud Str. 25, 53105, Bonn, Germany
| | - Maximilian Kruse
- Neuroradiology, Department of Radiology, University Clinics Bonn, Sigmund Freud Str. 25, 53105, Bonn, Germany
| | - Daniel Delev
- Department of Neurosurgery, University Clinics Bonn, Bonn, Germany.,Department of Neurosurgery, University Clinics Freiburg, Freiburg, Germany
| | - Alexander Grote
- Department of Neurosurgery, University Clinics Bonn, Bonn, Germany.,Department of Neurosurgery, Evangelic Hospital of Bethel, Bielefeld, Germany
| | - Albert Becker
- Institute of Neuropathology, University Clinics Bonn, Bonn, Germany
| |
Collapse
|
38
|
Salman MM, Sheilabi MA, Bhattacharyya D, Kitchen P, Conner AC, Bill RM, Woodroofe MN, Conner MT, Princivalle AP. Transcriptome analysis suggests a role for the differential expression of cerebral aquaporins and the MAPK signalling pathway in human temporal lobe epilepsy. Eur J Neurosci 2017; 46:2121-2132. [PMID: 28715131 DOI: 10.1111/ejn.13652] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 01/12/2023]
Abstract
Epilepsies are common disorders of the central nervous system (CNS), affecting up to 2% of the global population. Pharmaco-resistance is a major clinical challenge affecting about 30% of temporal lobe epilepsy (TLE) patients. Water homeostasis has been shown crucial for regulation of neuronal excitability. The control of water movement is achieved through a family of small integral membrane channel proteins called aquaporins (AQPs). Despite the fact that changes in water homeostasis occur in sclerotic hippocampi of people with TLE, the expression of AQPs in the epileptic brain is not fully characterised. This study uses microarray and ELISA methods to analyse the mRNA and protein expression of the human cerebral AQPs in sclerotic hippocampi (TLE-HS) and adjacent neocortex tissue (TLE-NC) of TLE patients. The expression of AQP1 and AQP4 transcripts was significantly increased, while that of the AQP9 transcript was significantly reduced in TLE-HS compared to TLE-NC. AQP4 protein expression was also increased while expression of AQP1 protein remained unchanged, and AQP9 was undetected. Microarray data analysis identified 3333 differentially regulated genes and suggested the involvement of the MAPK signalling pathway in TLE pathogenesis. Proteome array data validated the translational profile for 26 genes and within the MAPK pathway (e.g. p38, JNK) that were identified as differentially expressed from microarray analysis. ELISA data showed that p38 and JNK inhibitors decrease AQP4 protein levels in cultured human primary cortical astrocytes. Elucidating the mechanism of selective regulation of different AQPs and associated regulatory proteins may provide a new therapeutic approach to epilepsy treatment.
Collapse
Affiliation(s)
- Mootaz M Salman
- Biomolecular Sciences Research Centre (BMRC), Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| | - Mariam A Sheilabi
- Biomolecular Sciences Research Centre (BMRC), Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| | | | - Philip Kitchen
- School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - Alex C Conner
- School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - Roslyn M Bill
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | - M Nicola Woodroofe
- Biomolecular Sciences Research Centre (BMRC), Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| | - Matthew T Conner
- Biomolecular Sciences Research Centre (BMRC), Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK.,Research Institute of Health Sciences, School of Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Alessandra P Princivalle
- Biomolecular Sciences Research Centre (BMRC), Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK
| |
Collapse
|
39
|
Targeted deletion of Aqp4 promotes the formation of astrocytic gap junctions. Brain Struct Funct 2017; 222:3959-3972. [DOI: 10.1007/s00429-017-1448-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/16/2017] [Indexed: 10/19/2022]
|
40
|
Hubbard JA, Szu JI, Binder DK. The role of aquaporin-4 in synaptic plasticity, memory and disease. Brain Res Bull 2017; 136:118-129. [PMID: 28274814 DOI: 10.1016/j.brainresbull.2017.02.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/25/2022]
Abstract
Since the discovery of aquaporins, it has become clear that the various mammalian aquaporins play critical physiological roles in water and ion balance in multiple tissues. Aquaporin-4 (AQP4), the principal aquaporin expressed in the central nervous system (CNS, brain and spinal cord), has been shown to mediate CNS water homeostasis. In this review, we summarize new and exciting studies indicating that AQP4 also plays critical and unanticipated roles in synaptic plasticity and memory formation. Next, we consider the role of AQP4 in Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), neuromyelitis optica (NMO), epilepsy, traumatic brain injury (TBI), and stroke. Each of these conditions involves changes in AQP4 expression and/or distribution that may be functionally relevant to disease physiology. Insofar as AQP4 is exclusively expressed on astrocytes, these data provide new evidence of "astrocytopathy" in the etiology of diverse neurological diseases.
Collapse
Affiliation(s)
- Jacqueline A Hubbard
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States
| | - Jenny I Szu
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States
| | - Devin K Binder
- Center for Glial-Neuronal Interactions, Division of Biomedical Sciences, School of Medicine, University of California, Riverside, United States.
| |
Collapse
|
41
|
Dossi E, Vasile F, Rouach N. Human astrocytes in the diseased brain. Brain Res Bull 2017; 136:139-156. [PMID: 28212850 PMCID: PMC5766741 DOI: 10.1016/j.brainresbull.2017.02.001] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/08/2017] [Accepted: 02/09/2017] [Indexed: 12/23/2022]
Abstract
Astrocytes are key active elements of the brain that contribute to information processing. They not only provide neurons with metabolic and structural support, but also regulate neurogenesis and brain wiring. Furthermore, astrocytes modulate synaptic activity and plasticity in part by controlling the extracellular space volume, as well as ion and neurotransmitter homeostasis. These findings, together with the discovery that human astrocytes display contrasting characteristics with their rodent counterparts, point to a role for astrocytes in higher cognitive functions. Dysfunction of astrocytes can thereby induce major alterations in neuronal functions, contributing to the pathogenesis of several brain disorders. In this review we summarize the current knowledge on the structural and functional alterations occurring in astrocytes from the human brain in pathological conditions such as epilepsy, primary tumours, Alzheimer's disease, major depressive disorder and Down syndrome. Compelling evidence thus shows that dysregulations of astrocyte functions and interplay with neurons contribute to the development and progression of various neurological diseases. Targeting astrocytes is thus a promising alternative approach that could contribute to the development of novel and effective therapies to treat brain disorders.
Collapse
Affiliation(s)
- Elena Dossi
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Flora Vasile
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.
| |
Collapse
|
42
|
Guo W, Shang DM, Cao JH, Feng K, He YC, Jiang Y, Wang S, Gao YF. Identifying and Analyzing Novel Epilepsy-Related Genes Using Random Walk with Restart Algorithm. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6132436. [PMID: 28255556 PMCID: PMC5309434 DOI: 10.1155/2017/6132436] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 01/15/2017] [Indexed: 02/07/2023]
Abstract
As a pathological condition, epilepsy is caused by abnormal neuronal discharge in brain which will temporarily disrupt the cerebral functions. Epilepsy is a chronic disease which occurs in all ages and would seriously affect patients' personal lives. Thus, it is highly required to develop effective medicines or instruments to treat the disease. Identifying epilepsy-related genes is essential in order to understand and treat the disease because the corresponding proteins encoded by the epilepsy-related genes are candidates of the potential drug targets. In this study, a pioneering computational workflow was proposed to predict novel epilepsy-related genes using the random walk with restart (RWR) algorithm. As reported in the literature RWR algorithm often produces a number of false positive genes, and in this study a permutation test and functional association tests were implemented to filter the genes identified by RWR algorithm, which greatly reduce the number of suspected genes and result in only thirty-three novel epilepsy genes. Finally, these novel genes were analyzed based upon some recently published literatures. Our findings implicate that all novel genes were closely related to epilepsy. It is believed that the proposed workflow can also be applied to identify genes related to other diseases and deepen our understanding of the mechanisms of these diseases.
Collapse
Affiliation(s)
- Wei Guo
- Department of Outpatient, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Dong-Mei Shang
- Department of Outpatient, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Jing-Hui Cao
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Kaiyan Feng
- Department of Computer Science, Guangdong AIB Polytechnic, Guangzhou 510507, China
| | - Yi-Chun He
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Yang Jiang
- Department of Surgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - ShaoPeng Wang
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Yu-Fei Gao
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| |
Collapse
|
43
|
Lapato AS, Szu JI, Hasselmann JPC, Khalaj AJ, Binder DK, Tiwari-Woodruff SK. Chronic demyelination-induced seizures. Neuroscience 2017; 346:409-422. [PMID: 28153692 DOI: 10.1016/j.neuroscience.2017.01.035] [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: 10/31/2016] [Revised: 01/13/2017] [Accepted: 01/23/2017] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) patients are three to six times more likely to develop epilepsy compared to the rest of the population. Seizures are more common in patients with early onset or progressive forms of the disease and prognosticate rapid progression to disability and death. Gray matter atrophy, hippocampal lesions, interneuron loss, and elevated juxtacortical lesion burden have been identified in MS patients with seizures; however, translational studies aimed at elucidating the pathophysiological processes underlying MS epileptogenesis are limited. Here, we report that cuprizone-mediated chronically demyelinated (9-12weeks) mice exhibit marked changes to dorsal hippocampal electroencephalography (EEG) and evidence of overt seizure activity. Immunohistochemical (IHC) analyses within the hippocampal CA1 region revealed extensive demyelination, loss of parvalbumin (PV+) interneurons, widespread gliosis, and changes in aquaporin-4 (AQP4) expression. Our results suggest that chronically demyelinated mice are a valuable model with which we may begin to understand the mechanisms underlying demyelination-induced seizures.
Collapse
Affiliation(s)
- Andrew S Lapato
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA; Center for Glial-Neuronal Interactions, University of California Riverside, Riverside, CA 92521, USA
| | - Jenny I Szu
- Neuroscience Graduate Program, University of California Riverside, Riverside, CA 92521, USA
| | - Jonathan P C Hasselmann
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA
| | - Anna J Khalaj
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA
| | - Devin K Binder
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA; Neuroscience Graduate Program, University of California Riverside, Riverside, CA 92521, USA; Center for Glial-Neuronal Interactions, University of California Riverside, Riverside, CA 92521, USA
| | - Seema K Tiwari-Woodruff
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA; Neuroscience Graduate Program, University of California Riverside, Riverside, CA 92521, USA; Center for Glial-Neuronal Interactions, University of California Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
44
|
Mechanisms of Excessive Extracellular Glutamate Accumulation in Temporal Lobe Epilepsy. Neurochem Res 2016; 42:1724-1734. [DOI: 10.1007/s11064-016-2105-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/17/2022]
|
45
|
Astrocyte Aquaporin Dynamics in Health and Disease. Int J Mol Sci 2016; 17:ijms17071121. [PMID: 27420057 PMCID: PMC4964496 DOI: 10.3390/ijms17071121] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/07/2016] [Accepted: 07/07/2016] [Indexed: 02/01/2023] Open
Abstract
The family of aquaporins (AQPs), membrane water channels, consists of diverse types of proteins that are mainly permeable to water; some are also permeable to small solutes, such as glycerol and urea. They have been identified in a wide range of organisms, from microbes to vertebrates and plants, and are expressed in various tissues. Here, we focus on AQP types and their isoforms in astrocytes, a major glial cell type in the central nervous system (CNS). Astrocytes have anatomical contact with the microvasculature, pia, and neurons. Of the many roles that astrocytes have in the CNS, they are key in maintaining water homeostasis. The processes involved in this regulation have been investigated intensively, in particular regulation of the permeability and expression patterns of different AQP types in astrocytes. Three aquaporin types have been described in astrocytes: aquaporins AQP1 and AQP4 and aquaglyceroporin AQP9. The aim here is to review their isoforms, subcellular localization, permeability regulation, and expression patterns in the CNS. In the human CNS, AQP4 is expressed in normal physiological and pathological conditions, but astrocytic expression of AQP1 and AQP9 is mainly associated with a pathological state.
Collapse
|
46
|
Hendriksen RGF, Schipper S, Hoogland G, Schijns OEMG, Dings JTA, Aalbers MW, Vles JSH. Dystrophin Distribution and Expression in Human and Experimental Temporal Lobe Epilepsy. Front Cell Neurosci 2016; 10:174. [PMID: 27458343 PMCID: PMC4937016 DOI: 10.3389/fncel.2016.00174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/21/2016] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE Dystrophin is part of a protein complex that connects the cytoskeleton to the extracellular matrix. In addition to its role in muscle tissue, it functions as an anchoring protein within the central nervous system such as in hippocampus and cerebellum. Its presence in the latter regions is illustrated by the cognitive problems seen in Duchenne Muscular Dystrophy (DMD). Since epilepsy is also supposed to constitute a comorbidity of DMD, it is hypothesized that dystrophin plays a role in neuronal excitability. Here, we aimed to study brain dystrophin distribution and expression in both, human and experimental temporal lobe epilepsy (TLE). METHOD Regional and cellular dystrophin distribution was evaluated in both human and rat hippocampi and in rat cerebellar tissue by immunofluorescent colocalization with neuronal (NeuN and calbindin) and glial (GFAP) markers. In addition, hippocampal dystrophin levels were estimated by Western blot analysis in biopsies from TLE patients, post-mortem controls, amygdala kindled (AK)-, and control rats. RESULTS Dystrophin was expressed in all hippocampal pyramidal subfields and in the molecular-, Purkinje-, and granular cell layer of the cerebellum. In these regions it colocalized with GFAP, suggesting expression in astrocytes such as Bergmann glia (BG) and velate protoplasmic astrocytes. In rat hippocampus and cerebellum there were neither differences in dystrophin positive cell types, nor in the regional dystrophin distribution between AK and control animals. Quantitatively, hippocampal full-length dystrophin (Dp427) levels were about 60% higher in human TLE patients than in post-mortem controls (p < 0.05), whereas the level of the shorter Dp71 isoform did not differ. In contrast, AK animals showed similar dystrophin levels as controls. CONCLUSION Dystrophin is ubiquitously expressed by astrocytes in the human and rat hippocampus and in the rat cerebellum. Hippocampal full-length dystrophin (Dp427) levels are upregulated in human TLE, but not in AK rats, possibly indicating a compensatory mechanism in the chronic epileptic human brain.
Collapse
Affiliation(s)
- Ruben G F Hendriksen
- Department of Neurology, Maastricht University Medical Centre Maastricht, Netherlands
| | - Sandra Schipper
- Department of Neurology, Maastricht University Medical CentreMaastricht, Netherlands; School for Mental Health and Neuroscience, Maastricht UniversityMaastricht, Netherlands
| | - Govert Hoogland
- School for Mental Health and Neuroscience, Maastricht UniversityMaastricht, Netherlands; Department of Neurosurgery, Maastricht University Medical CentreMaastricht, Netherlands
| | - Olaf E M G Schijns
- Department of Neurosurgery, Maastricht University Medical Centre Maastricht, Netherlands
| | - Jim T A Dings
- Department of Neurosurgery, Maastricht University Medical Centre Maastricht, Netherlands
| | - Marlien W Aalbers
- Department of Neurosurgery, Groningen University Medical Centre Groningen, Netherlands
| | - Johan S H Vles
- Department of Neurology, Maastricht University Medical Centre Maastricht, Netherlands
| |
Collapse
|
47
|
Hubbard JA, Szu JI, Yonan JM, Binder DK. Regulation of astrocyte glutamate transporter-1 (GLT1) and aquaporin-4 (AQP4) expression in a model of epilepsy. Exp Neurol 2016; 283:85-96. [PMID: 27155358 DOI: 10.1016/j.expneurol.2016.05.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/23/2016] [Accepted: 05/01/2016] [Indexed: 12/31/2022]
Abstract
Astrocytes regulate extracellular glutamate and water homeostasis through the astrocyte-specific membrane proteins glutamate transporter-1 (GLT1) and aquaporin-4 (AQP4), respectively. The role of astrocytes and the regulation of GLT1 and AQP4 in epilepsy are not fully understood. In this study, we investigated the expression of GLT1 and AQP4 in the intrahippocampal kainic acid (IHKA) model of temporal lobe epilepsy (TLE). We used real-time polymerase chain reaction (RT-PCR), Western blot, and immunohistochemical analysis at 1, 4, 7, and 30days after kainic acid-induced status epilepticus (SE) to determine hippocampal glial fibrillary acidic protein (GFAP, a marker for reactive astrocytes), GLT1, and AQP4 expression changes during the development of epilepsy (epileptogenesis). Following IHKA, all mice had SE and progressive increases in GFAP immunoreactivity and GFAP protein expression out to 30days post-SE. A significant initial increase in dorsal hippocampal GLT1 immunoreactivity and protein levels were observed 1day post SE and followed by a marked downregulation at 4 and 7days post SE with a return to near control levels by 30days post SE. AQP4 dorsal hippocampal protein expression was significantly downregulated at 1day post SE and was followed by a gradual return to baseline levels with a significant increase in ipsilateral protein levels by 30days post SE. Transient increases in GFAP and AQP4 mRNA were also observed. Our findings suggest that specific molecular changes in astrocyte glutamate transporters and water channels occur during epileptogenesis in this model, and suggest the novel therapeutic strategy of restoring glutamate and water homeostasis.
Collapse
Affiliation(s)
- Jacqueline A Hubbard
- Department of Biochemistry and Molecular Biology, University of California, Riverside, USA
| | - Jenny I Szu
- Neuroscience Graduate Program, University of California, Riverside, USA
| | - Jennifer M Yonan
- Neuroscience Graduate Program, University of California, Riverside, USA
| | - Devin K Binder
- Neuroscience Graduate Program, University of California, Riverside, USA; Center for Glial-Neuronal Interactions, University of California, Riverside, USA; Division of Biomedical Sciences, School of Medicine, University of California, Riverside.
| |
Collapse
|
48
|
Crucial role of astrocytes in temporal lobe epilepsy. Neuroscience 2016; 323:157-69. [DOI: 10.1016/j.neuroscience.2014.12.047] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/25/2014] [Accepted: 12/30/2014] [Indexed: 11/30/2022]
|
49
|
Dixit AB, Banerjee J, Srivastava A, Tripathi M, Sarkar C, Kakkar A, Jain M, Chandra PS. RNA-seq analysis of hippocampal tissues reveals novel candidate genes for drug refractory epilepsy in patients with MTLE-HS. Genomics 2016; 107:178-88. [DOI: 10.1016/j.ygeno.2016.04.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/12/2016] [Accepted: 04/05/2016] [Indexed: 12/13/2022]
|
50
|
Phosphorylation of p38 MAPK mediates aquaporin 9 expression in rat brains during permanent focal cerebral ischaemia. J Mol Histol 2015; 46:273-81. [DOI: 10.1007/s10735-015-9618-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/17/2015] [Indexed: 11/26/2022]
|