1
|
Ruffolo G, Gaeta A, Cannata B, Pinzaglia C, Aronica E, Morano A, Cifelli P, Palma E. GABAergic Neurotransmission in Human Tissues Is Modulated by Cannabidiol. LIFE (BASEL, SWITZERLAND) 2022; 12:life12122042. [PMID: 36556407 PMCID: PMC9786817 DOI: 10.3390/life12122042] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
Recently, the potential use of phytocannabinoids (pCBs) to treat different pathological conditions has attracted great attention in the scientific community. Among the different pCBs, cannabidiol (CBD) has showed interesting biological properties, making it a promising molecule with a high security profile that has been approved for treatment as an add-on therapy in patients afflicted by severe pharmaco-resistant epilepsy, including Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS) and tuberous sclerosis complex (TSC). CBD is pharmacologically considered a "dirty drug", since it has the capacity to bind different targets and to activate several cellular pathways. GABAergic impairment is one of the key processes during the epileptogenesis period able to induce a generalized hyperexcitability of the central nervous system (CNS), leading to epileptic seizures. Here, by using the microtransplantation of human brain membranes approach in Xenopus oocytes and electrophysiological recordings, we confirm the ability of CBD to modulate GABAergic neurotransmission in human cerebral tissues obtained from patients afflicted by different forms of pharmaco-resistant epilepsies, such as DS, TSC, focal cortical dysplasia (FCD) type IIb and temporal lobe epilepsy (TLE). Furthermore, using cDNAs encoding for human GABAA receptor subunits, we found that α1β2 receptors are still affected by CBD, while classical benzodiazepine lost its efficacy as expected.
Collapse
Affiliation(s)
- Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy
- IRCCS San Raffaele Roma, 00163 Rome, Italy
| | - Alessandro Gaeta
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy
| | - Beatrice Cannata
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy
| | - Camilla Pinzaglia
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy
| | - Eleonora Aronica
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland, 0397 Heemstede, The Netherlands
| | - Alessandra Morano
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy
| | - Pierangelo Cifelli
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy
- Correspondence:
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy
- IRCCS San Raffaele Roma, 00163 Rome, Italy
| |
Collapse
|
2
|
Nasarudeen R, Singh A, Rana ZS, Punnakkal P. Epileptiform activity induced metaplasticity impairs bidirectional plasticity in the hippocampal CA1 synapses via GluN2B NMDA receptors. Exp Brain Res 2022; 240:3339-3349. [DOI: 10.1007/s00221-022-06486-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/10/2022] [Indexed: 11/09/2022]
|
3
|
Ruffolo G, Alfano V, Romagnolo A, Zimmer T, Mills JD, Cifelli P, Gaeta A, Morano A, Anink J, Mühlebner A, Vezzani A, Aronica E, Palma E. GABA A receptor function is enhanced by Interleukin-10 in human epileptogenic gangliogliomas and its effect is counteracted by Interleukin-1β. Sci Rep 2022; 12:17956. [PMID: 36289354 PMCID: PMC9605959 DOI: 10.1038/s41598-022-22806-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/19/2022] [Indexed: 01/24/2023] Open
Abstract
Gangliogliomas (GGs) are low-grade brain tumours that cause intractable focal epilepsy in children and adults. In GG, as in epileptogenic focal malformations (i.e., tuberous sclerosis complex, TSC), there is evidence of sustained neuroinflammation with involvement of the pro-inflammatory cytokine IL-1β. On the other hand, anti-inflammatory mediators are less studied but bear relevance for understanding seizure mechanisms. Therefore, we investigated the effect of the key anti-inflammatory cytokine IL-10 on GABAergic neurotransmission in GG. We assessed the IL-10 dependent signaling by transcriptomic analysis, immunohistochemistry and performed voltage-clamp recordings on Xenopus oocytes microtransplanted with cell membranes from brain specimens, to overcome the limited availability of acute GG slices. We report that IL-10-related mRNAs were up-regulated in GG and slightly in TSC. Moreover, we found IL-10 receptors are expressed by neurons and astroglia. Furthermore, GABA currents were potentiated significantly by IL-10 in GG. This effect was time and dose-dependent and inhibited by blockade of IL-10 signaling. Notably, in the same tissue, IL-1β reduced GABA current amplitude and prevented the IL-10 effect. These results suggest that in epileptogenic tissue, pro-inflammatory mechanisms of hyperexcitability prevail over key anti-inflammatory pathways enhancing GABAergic inhibition. Hence, boosting the effects of specific anti-inflammatory molecules could resolve inflammation and reduce intractable seizures.
Collapse
Affiliation(s)
- Gabriele Ruffolo
- grid.7841.aDepartment of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy ,grid.18887.3e0000000417581884IRCCS San Raffaele Roma, Rome, Italy
| | - Veronica Alfano
- grid.7841.aDepartment of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy ,grid.18887.3e0000000417581884IRCCS San Raffaele Roma, Rome, Italy
| | - Alessia Romagnolo
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands
| | - Till Zimmer
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands
| | - James D. Mills
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands ,grid.83440.3b0000000121901201Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK ,grid.452379.e0000 0004 0386 7187Chalfont Centre for Epilepsy, Chalfont St Peter, UK
| | - Pierangelo Cifelli
- grid.158820.60000 0004 1757 2611Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, L’Aquila, Italy
| | - Alessandro Gaeta
- grid.7841.aDepartment of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Alessandra Morano
- grid.7841.aDepartment of Human Neuroscience, University of Rome Sapienza, Rome, Italy
| | - Jasper Anink
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands
| | - Angelika Mühlebner
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands ,grid.7692.a0000000090126352Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Annamaria Vezzani
- grid.4527.40000000106678902Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Eleonora Aronica
- grid.484519.5Department of (Neuro)Pathology, Amsterdam UMC Location University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, The Netherlands ,grid.419298.f0000 0004 0631 9143Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands
| | - Eleonora Palma
- grid.7841.aDepartment of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy ,grid.18887.3e0000000417581884IRCCS San Raffaele Roma, Rome, Italy
| |
Collapse
|
4
|
Scalise S, Zannino C, Lucchino V, Lo Conte M, Scaramuzzino L, Cifelli P, D’Andrea T, Martinello K, Fucile S, Palma E, Gambardella A, Ruffolo G, Cuda G, Parrotta EI. Human iPSC Modeling of Genetic Febrile Seizure Reveals Aberrant Molecular and Physiological Features Underlying an Impaired Neuronal Activity. Biomedicines 2022; 10:biomedicines10051075. [PMID: 35625812 PMCID: PMC9138645 DOI: 10.3390/biomedicines10051075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/01/2023] Open
Abstract
Mutations in SCN1A gene, encoding the voltage-gated sodium channel (VGSC) NaV1.1, are widely recognized as a leading cause of genetic febrile seizures (FS), due to the decrease in the Na+ current density, mainly affecting the inhibitory neuronal transmission. Here, we generated induced pluripotent stem cells (iPSCs)-derived neurons (idNs) from a patient belonging to a genetically well-characterized Italian family, carrying the c.434T > C mutation in SCN1A gene (hereafter SCN1AM145T). A side-by-side comparison of diseased and healthy idNs revealed an overall maturation delay of SCN1AM145T cells. Membranes isolated from both diseased and control idNs were injected into Xenopus oocytes and both GABA and AMPA currents were successfully recorded. Patch-clamp measurements on idNs revealed depolarized action potential for SCN1AM145T, suggesting a reduced excitability. Expression analyses of VGSCs and chloride co-transporters NKCC1 and KCC2 showed a cellular “dysmaturity” of mutated idNs, strengthened by the high expression of SCN3A, a more fetal-like VGSC isoform, and a high NKCC1/KCC2 ratio, in mutated cells. Overall, we provide strong evidence for an intrinsic cellular immaturity, underscoring the role of mutant NaV1.1 in the development of FS. Furthermore, our data are strengthening previous findings obtained using transfected cells and recordings on human slices, demonstrating that diseased idNs represent a powerful tool for personalized therapy and ex vivo drug screening for human epileptic disorders.
Collapse
Affiliation(s)
- Stefania Scalise
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Clara Zannino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Valeria Lucchino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Michela Lo Conte
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Luana Scaramuzzino
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
| | - Pierangelo Cifelli
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), University of Aquila, 67100 Aquila, Italy;
| | - Tiziano D’Andrea
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | | | - Sergio Fucile
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS Neuromed, Via Atinense, 86077 Pozzilli, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
| | - Antonio Gambardella
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome, Sapienza, P.le Aldo Moro, 5, 00185 Rome, Italy; (T.D.); (S.F.); (E.P.)
- IRCCS San Raffaele Roma, Via della Pisana, 00163 Rome, Italy
- Correspondence: (G.R.); (G.C.)
| | - Giovanni Cuda
- Department of Experimental and Clinical Medicine, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (S.S.); (C.Z.); (V.L.); (M.L.C.); (L.S.)
- Correspondence: (G.R.); (G.C.)
| | - Elvira Immacolata Parrotta
- Department of Medical and Surgical Sciences, University Magna Graecia of Catanzaro, Viale Europa, 88100 Catanzaro, Italy; (A.G.); (E.I.P.)
| |
Collapse
|
5
|
Zamberletti E, Rubino T, Parolaro D. Therapeutic potential of cannabidivarin for epilepsy and autism spectrum disorder. Pharmacol Ther 2021; 226:107878. [PMID: 33895189 DOI: 10.1016/j.pharmthera.2021.107878] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/01/2021] [Indexed: 12/11/2022]
Abstract
Recent years have seen a renewed interest on the possible therapeutic exploitations of specific cannabinoids derived from the Cannabis sativa plant. Thus far, the most studied non-psychotomimetic cannabinoid is cannabidiol (CBD), which has shown promising therapeutic potential for relieving a variety of neurological diseases. However, also its propyl analogue, cannabidivarin (CBDV), has recently gained much attention as a potential therapeutic agent for the management of disabling neurological conditions. This review aims at providing a comprehensive and updated overview of the available animal and human data, which have investigated the possible therapeutic potential of CBDV for the management of epilepsy and autism spectrum disorder.
Collapse
Affiliation(s)
- Erica Zamberletti
- Dept. of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy.
| | - Tiziana Rubino
- Dept. of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy
| | - Daniela Parolaro
- Dept. of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy; Zardi-Gori Foundation, Milan, Italy.
| |
Collapse
|
6
|
Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
Collapse
|
7
|
Cifelli P, Di Angelantonio S, Alfano V, Morano A, De Felice E, Aronica E, Ruffolo G, Palma E. Dissecting the Molecular Determinants of GABA A Receptors Current Rundown, a Hallmark of Refractory Human Epilepsy. Brain Sci 2021; 11:brainsci11040441. [PMID: 33808090 PMCID: PMC8066365 DOI: 10.3390/brainsci11040441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 11/16/2022] Open
Abstract
GABAA receptors-(Rs) are fundamental for the maintenance of an efficient inhibitory function in the central nervous system (CNS). Their dysfunction is associated with a wide range of CNS disorders, many of which characterized by seizures and epilepsy. Recently, an increased use-dependent desensitization due to a repetitive GABA stimulation (GABAA current rundown) of GABAARs has been associated with drug-resistant temporal lobe epilepsy (TLE). Here, we aimed to investigate the molecular determinants of GABAA current rundown with two different heterologous expression systems (Xenopus oocytes and human embryonic kidney cells; HEK) which allowed us to manipulate receptor stoichiometry and to study the GABAA current rundown on different GABAAR configurations. To this purpose, we performed electrophysiology experiments using two-electrode voltage clamp in oocytes and confirming part of our results in HEK. We found that different degrees of GABAA current rundown can be associated with the expression of different GABAAR β-subunits reaching the maximum current decrease when functional α1β2 receptors are expressed. Furthermore, the blockade of phosphatases can prevent the current rundown observed in α1β2 GABAARs. Since GABAAR represents one important therapeutic target in the treatment of human epilepsy, our results could open new perspectives on the therapeutic management of drug-resistant patients showing a GABAergic impairment.
Collapse
Affiliation(s)
- Pierangelo Cifelli
- Department of Applied Clinical and Biotechnological Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Silvia Di Angelantonio
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (S.D.A.); (V.A.); (E.D.F.); (E.P.)
- Center for Life Nanoscience, Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
| | - Veronica Alfano
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (S.D.A.); (V.A.); (E.D.F.); (E.P.)
| | - Alessandra Morano
- Department of Human Neuroscience, University of Rome Sapienza, 00185 Rome, Italy;
| | - Eleonora De Felice
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (S.D.A.); (V.A.); (E.D.F.); (E.P.)
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, 1105 Amsterdam, The Netherlands;
- Stichting Epilepsie Instellingen Nederland, 0397 Heemstede, The Netherlands
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (S.D.A.); (V.A.); (E.D.F.); (E.P.)
- Correspondence:
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (S.D.A.); (V.A.); (E.D.F.); (E.P.)
| |
Collapse
|
8
|
Ruffolo G, Martinello K, Labate A, Cifelli P, Fucile S, Di Gennaro G, Quattrone A, Esposito V, Limatola C, Giangaspero F, Aronica E, Palma E, Gambardella A. Modulation of GABAergic dysfunction due to SCN1A mutation linked to Hippocampal Sclerosis. Ann Clin Transl Neurol 2020; 7:1726-1731. [PMID: 32761786 PMCID: PMC7480916 DOI: 10.1002/acn3.51150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/11/2020] [Accepted: 07/16/2020] [Indexed: 12/21/2022] Open
Abstract
We compared GABAergic function and neuronal excitability in the hippocampal tissue of seven sporadic MTLE patients with a patient carrying a SCN1A loss‐of‐function mutation. All had excellent outcome from anterior temporal lobectomy, and neuropathological study always showed characteristic hippocampal sclerosis (Hs). Compared to MTLE patients, there was a more severe impairment of GABAergic transmission, due to the lower GABAergic activity related to the NaV1.1 loss‐of‐function, in addition to the typical GABA‐current rundown, a hallmark of sporadic MTLE. Our results give evidence that a pharmacological rescuing of the GABAergic dysfunction may represent a promising strategy for the treatment of these patients.
Collapse
Affiliation(s)
- Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | | | - Angelo Labate
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy.,Institute of Molecular Bioimaging and Physiology of the National Research Council, Catanzaro, Italy
| | - Pierangelo Cifelli
- Department of Biotechnological and Applied Clinical Sciences (DISCAB), Amsterdam UMC, University of L'Aquila, L'Aquila, Italy
| | - Sergio Fucile
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy.,IRCCS Neuromed, Pozzilli, Isernia, Italy
| | | | - Andrea Quattrone
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy
| | | | - Cristina Limatola
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy.,IRCCS Neuromed, Pozzilli, Isernia, Italy
| | | | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Stichting Epilepsie Instellingen Nederland, Heemstede, the Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Antonio Gambardella
- Institute of Neurology, University Magna Graecia, Catanzaro, Italy.,Institute of Molecular Bioimaging and Physiology of the National Research Council, Catanzaro, Italy
| |
Collapse
|
9
|
Bregestovski P, Heuser J, Martínez-Torres A. Ricardo Miledi - Outstanding Neuroscientist of XX-XXI Centuries. Neuroscience 2020; 439:1-9. [PMID: 32620217 DOI: 10.1016/j.neuroscience.2020.04.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Piotr Bregestovski
- Institut de Neurosciences des Systemes, UMR INSERM 1106, Aix-Marseille Universite, Faculte de Medecine, 27 Bd Jean Moulin, 13005 Marseille, France
| | - John Heuser
- Section on Integrative Biophysics, National Institute of Child Health & Human Development, National Institutes of Health, Bethesda, MD, USA.
| | - Ataulfo Martínez-Torres
- Laboratory of Molecular & Cellular Neurobiology, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Quurétaro, 76230, Mexico.
| |
Collapse
|
10
|
Cifelli P, Ruffolo G, De Felice E, Alfano V, van Vliet EA, Aronica E, Palma E. Phytocannabinoids in Neurological Diseases: Could They Restore a Physiological GABAergic Transmission? Int J Mol Sci 2020; 21:E723. [PMID: 31979108 PMCID: PMC7038116 DOI: 10.3390/ijms21030723] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 01/19/2023] Open
Abstract
γ-Aminobutyric acid type A receptors (GABAARs) are the main inhibitory mediators in the central nervous system (CNS). GABAARs are pentameric ligand gated ion channels, and the main subunit composition is usually 2α2βγ, with various isotypes assembled within a set of 19 different subunits. The inhibitory function is mediated by chloride ion movement across the GABAARs, activated by synaptic GABA release, reducing neuronal excitability in the adult CNS. Several studies highlighted the importance of GABA-mediated transmission during neuro-development, and its involvement in different neurological and neurodevelopmental diseases, from anxiety to epilepsy. However, while it is well known how different classes of drugs are able to modulate the GABAARs function (benzodiazepines, barbiturates, neurosteroids, alcohol), up to now little is known about GABAARs and cannabinoids interaction in the CNS. Endocannabinoids and phytocannabinoids are lately emerging as a new class of promising drugs for a wide range of neurological conditions, but their safety as medication, and their mechanisms of action are still to be fully elucidated. In this review, we will focus our attention on two of the most promising molecules (Δ9-tetrahydrocannabinol; Δ9-THC and cannabidiol; CBD) of this new class of drugs and their possible mechanism of action on GABAARs.
Collapse
Affiliation(s)
| | - Gabriele Ruffolo
- IRCCS San Raffaele Pisana, 00163 Rome, Italy; (G.R.); (E.D.F.)
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, 00185 Rome, Italy;
| | | | - Veronica Alfano
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, 00185 Rome, Italy;
| | - Erwin Alexander van Vliet
- Amsterdam UMC, University of Amsterdam, Department of (Neuro) Pathology, 1105 Amsterdam, The Netherlands; (E.A.v.V.); (E.A.)
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1090 Amsterdam, The Netherlands
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro) Pathology, 1105 Amsterdam, The Netherlands; (E.A.v.V.); (E.A.)
- Stichting Epilepsie Instellingen Nederland (SEIN), 0397 Heemstede, The Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, 00185 Rome, Italy;
| |
Collapse
|
11
|
Roseti C, Cifelli P, Ruffolo G, Barbieri E, Guescini M, Esposito V, Di Gennaro G, Limatola C, Giovannelli A, Aronica E, Palma E. Erythropoietin Increases GABA A Currents in Human Cortex from TLE Patients. Neuroscience 2019; 439:153-162. [PMID: 31047977 DOI: 10.1016/j.neuroscience.2019.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 11/15/2022]
Abstract
Erythropoietin (EPO) is a hematopoietic growth factor that has an important role in the erythropoiesis. EPO and its receptor (EPO-R) are expressed all over in the mammalian brain. Furthermore, it has been reported that EPO may exert neuroprotective effect in animal models of brain disorders as ischemia and epilepsy. Here, we investigate whether EPO could modulate the GABA-evoked currents (IGABA) in both human epileptic and non-epileptic control brain tissues. Therefore, we transplanted in Xenopus oocytes cell membranes obtained from autoptic and surgical brain tissues (cortex) of seven temporal lope epilepsy (TLE) patients and of five control patients. Two microelectrodes voltage-clamp technique has been used to record IGABA. Moreover, qRT-PCR assay was performed in the same human tissues to quantify the relative gene expression levels of EPO/EPO-R. To further confirm experiments in oocytes, we performed additional experiments using patch-clamp recording in slices obtained from rat cerebellum. We show that exposure to EPO significantly increased the amplitude of the IGABA in all the patients analyzed. No differences in the expression of EPO and EPO-R in both TLE and control patients have been found. Notably, the increase of IGABA has been recorded also in rat cerebellar slices. Our findings show a new modulatory action of EPO on GABAA receptors (GABAA-Rs). This effect could be relevant to balance the GABAergic dysfunction in human TLE. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.
Collapse
Affiliation(s)
| | - Pierangelo Cifelli
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy; IRCCS San Raffaele Pisana, Rome, Italy
| | - Elena Barbieri
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | - Michele Guescini
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | | | | | - Cristina Limatola
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy; IRCCS Neuromed, Pozzilli, (IS), Italy
| | - Aldo Giovannelli
- Department of Applied Clinical and Biotechnological Sciences, University of L'Aquila, L'Aquila, Italy
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), the Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy.
| |
Collapse
|
12
|
Zestos AG, Luna-Munguia H, Stacey WC, Kennedy RT. Use and Future Prospects of in Vivo Microdialysis for Epilepsy Studies. ACS Chem Neurosci 2019; 10:1875-1883. [PMID: 30001105 DOI: 10.1021/acschemneuro.8b00271] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epilepsy is a common neurological disease characterized by recurrent unpredictable seizures. For the last 30 years, microdialysis sampling has been used to measure changes in excitatory and inhibitory neurotransmitter concentrations before, during, and after seizures. These advances have fostered breakthroughs in epilepsy research by identifying neurochemical changes associated with seizures and correlating them to electrophysiological data. Recent advances in methodology may be useful in further delineating the chemical underpinnings of seizures. A new model of ictogenesis has been developed that allows greater control over the timing of seizures that are similar to spontaneous seizures. This model will facilitate making chemical measurements before and during a seizure. Recent advancements in microdialysis sampling, including the use of segmented flow, "fast" liquid chromatography (LC), and capillary electrophoresis with laser-induced fluorescence (CE-LIF) have significantly improved temporal resolution to better than 1 min, which could be used to measure transient, spontaneous neurochemical changes associated with seizures. Microfabricated sampling probes that are markedly smaller than conventional probes and allow for a much greater spatial resolution have been developed. They may allow the targeting of specific brain regions important to epilepsy studies. Coupling microdialysis sampling to optogenetics and light-stimulated release of neurotransmitters may also prove useful for studying epileptic seizures.
Collapse
Affiliation(s)
- Alexander G. Zestos
- Department of Chemistry, Center for Behavioral Neuroscience, American University, Washington, D.C. 20016, United States
| | - Hiram Luna-Munguia
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, Queretaro 76230, Mexico
| | - William C. Stacey
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
13
|
Excitotoxicity, neuroinflammation and oxidant stress as molecular bases of epileptogenesis and epilepsy-derived neurodegeneration: The role of vitamin E. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1098-1112. [PMID: 30703511 DOI: 10.1016/j.bbadis.2019.01.026] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/15/2019] [Accepted: 01/24/2019] [Indexed: 12/14/2022]
Abstract
Glutamate-mediated excitotoxicity, neuroinflammation, and oxidative stress are common underlying events in neurodegeneration. This pathogenic "triad" characterizes the neurobiology of epilepsy, leading to seizure-induced cell death, increased susceptibility to neuronal synchronization and network alterations. Along with other maladaptive changes, these events pave the way to spontaneous recurrent seizures and progressive degeneration of the interested brain areas. In vivo models of epilepsy are available to explore such epileptogenic mechanisms, also assessing the efficacy of chemoprevention and therapy strategies at the pre-clinical level. The kainic acid model of pharmacological excitotoxicity and epileptogenesis is one of the most investigated mimicking the chronicization profile of temporal lobe epilepsy in humans. Its pathogenic cues include inflammatory and neuronal death pathway activation, mitochondrial disturbances and lipid peroxidation of several regions of the brain, the most vulnerable being the hippocampus. The importance of neuroinflammation and lipid peroxidation as underlying molecular events of brain damage was demonstrated in this model by the possibility to counteract the related maladaptive morphological and functional changes of this organ with vitamin E, the main fat-soluble cellular antioxidant and "conditional" co-factor of enzymatic pathways involved in polyunsaturated lipid metabolism and inflammatory signaling. The present review paper provides an overview of the literature supporting the potential for a timely intervention with vitamin E therapy in clinical management of seizures and epileptogenic processes associated with excitotoxicity, neuroinflammation and lipid peroxidation, i.e. the pathogenic "triad".
Collapse
|
14
|
Zwart R, Mazzo F, Sher E. Microtransplantation of human brain receptors into oocytes to tackle key questions in drug discovery. Drug Discov Today 2018; 24:533-543. [PMID: 30395928 DOI: 10.1016/j.drudis.2018.10.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/18/2018] [Accepted: 10/30/2018] [Indexed: 10/27/2022]
Abstract
It is important in drug discovery to demonstrate that activity of novel drugs found by screening on recombinant receptors translates to activity on native human receptors in brain areas affected by disease. In this review, we summarise the development and use of the microtransplantation technique. Native receptors are reconstituted from human brain tissues into oocytes from the frog Xenopus laevis where they can be functionally assessed. Oocytes microtransplanted with hippocampal tissue from an epileptic patient were used to demonstrate that new antiepileptic agents act on receptors in diseased tissue. Furthermore, frozen post-mortem human tissues were used to show that drugs are active on receptors in brain areas associated with a disease; but not in areas associated with side effects.
Collapse
Affiliation(s)
- Ruud Zwart
- Eli Lilly, Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, GU20 6PH, UK.
| | - Francesca Mazzo
- Eli Lilly, Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, GU20 6PH, UK
| | - Emanuele Sher
- Eli Lilly, Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, GU20 6PH, UK
| |
Collapse
|
15
|
Ruffolo G, Cifelli P, Roseti C, Thom M, van Vliet EA, Limatola C, Aronica E, Palma E. A novel GABAergic dysfunction in human Dravet syndrome. Epilepsia 2018; 59:2106-2117. [DOI: 10.1111/epi.14574] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/11/2018] [Accepted: 09/11/2018] [Indexed: 01/09/2023]
Affiliation(s)
- Gabriele Ruffolo
- Department of Physiology and Pharmacology; Pasteur Institute-Cenci Bolognetti Foundation; Sapienza University of Rome; Rome Italy
| | - Pierangelo Cifelli
- Department of Physiology and Pharmacology; Pasteur Institute-Cenci Bolognetti Foundation; Sapienza University of Rome; Rome Italy
- IRCCS Neuromed; Pozzilli Italy
| | | | - Maria Thom
- Department of Clinical and Experimental Epilepsy; University College London Institute of Neurology; London UK
| | - Erwin A. van Vliet
- Department of (Neuro)Pathology; Amsterdam UMC; University of Amsterdam; Amsterdam Neuroscience; Amsterdam The Netherlands
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Cristina Limatola
- Department of Physiology and Pharmacology; Pasteur Institute-Cenci Bolognetti Foundation; Sapienza University of Rome; Rome Italy
- IRCCS Neuromed; Pozzilli Italy
| | - Eleonora Aronica
- Department of (Neuro)Pathology; Amsterdam UMC; University of Amsterdam; Amsterdam Neuroscience; Amsterdam The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN); Heemstede The Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology; Pasteur Institute-Cenci Bolognetti Foundation; Sapienza University of Rome; Rome Italy
- IRCCS San Raffaele Pisana; Rome Italy
| |
Collapse
|
16
|
Obaid S, Tucholka A, Ghaziri J, Jodoin PM, Morency F, Descoteaux M, Bouthillier A, Nguyen DK. Cortical thickness analysis in operculo-insular epilepsy. NEUROIMAGE-CLINICAL 2018; 19:727-733. [PMID: 30003025 PMCID: PMC6040575 DOI: 10.1016/j.nicl.2018.05.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 05/23/2018] [Accepted: 05/25/2018] [Indexed: 01/06/2023]
Abstract
Background In temporal lobe epilepsy (TLE), advanced neuroimaging techniques reveal anomalies extending beyond the temporal lobe such as thinning of fronto-central cortices. Operculo-insular epilepsy (OIE) is an under-recognized and poorly characterized condition with the potential of mimicking TLE. In this work, we investigated insular and extra-insular cortical thickness (CT) changes in OIE. Methods All participants (14 patients with refractory OIE, 9 age- and sex-matched patients with refractory TLE and 26 healthy controls) underwent a T1-weighted acquisition on a 3 T MRI. Anatomical images were processed with Advanced Normalization Tools. Between-group analysis of CT was performed using a two-sided t-test (threshold of p < 0.05 after correction for multiple comparisons; cut-off threshold of 250 voxels) between (i) patients with OIE vs TLE, and (ii) patients with OIE vs healthy controls. Results Significant widespread thinning was observed in OIE patients as compared with healthy controls mainly in the ipsilateral insula, peri-rolandic region, orbito-frontal area, mesiotemporal structures and lateral temporal neocortex. Contralateral cortical shrinkage followed a similar albeit milder and less diffuse pattern.The CT of OIE patients was equal or reduced relative to the TLE group for every cortical region analyzed. Thinning was observed diffusely in OIE patients, predominantly inboth insulae and the ipsilateral occipito-temporal area. Conclusion Our results reveal structural anomalies extending beyond the operculo-insular area in OIE.
Collapse
Affiliation(s)
- Sami Obaid
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada; Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Service de Neurochirurgie, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Alan Tucholka
- Barcelona Beta Brain Research Center, Foundation Pasqual Maragall, Barcelona, Spain
| | - Jimmy Ghaziri
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de psychologie, Université du Québec à Montréal, Montréal, Québec, Canada
| | - Pierre-Marc Jodoin
- Sherbrooke Connectivity Imaging Lab (SCIL), Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Félix Morency
- Sherbrooke Connectivity Imaging Lab (SCIL), Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Maxime Descoteaux
- Sherbrooke Connectivity Imaging Lab (SCIL), Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Alain Bouthillier
- Service de Neurochirurgie, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Dang K Nguyen
- Département de Neurosciences, Université de Montréal, Montréal, Québec, Canada; Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Service de Neurologie, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
| |
Collapse
|
17
|
A novel action of lacosamide on GABA A currents sets the ground for a synergic interaction with levetiracetam in treatment of epilepsy. Neurobiol Dis 2018; 115:59-68. [PMID: 29621596 DOI: 10.1016/j.nbd.2018.03.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/03/2018] [Accepted: 03/30/2018] [Indexed: 01/01/2023] Open
Abstract
Epilepsy is one of the most common chronic neurological diseases, and its pharmacological treatment holds great importance for both physicians and national authorities, especially considering the high proportion of drug-resistant patients (about 30%). Lacosamide (LCM) is an effective and well-tolerated new-generation antiepileptic drug (AED), currently licensed as add-on therapy for partial-onset seizures. However, LCM mechanism of action is still a matter of debate, although its effect on the voltage sensitive sodium channels is by far the most recognized. This study aimed to retrospectively analyze a cohort of 157 drug-resistant patients treated with LCM to describe the most common and effective therapeutic combinations and to investigate if the LCM can affect also GABAA-mediated neurotransmission as previously shown for levetiracetam (LEV). In our cohort, LEV resulted the compound most frequently associated with LCM in the responder subgroup. We therefore translated this clinical observation into the laboratory bench by taking advantage of the technique of "membrane micro-transplantation" in Xenopus oocytes and electrophysiological approaches to study human GABAA-evoked currents. In cortical brain tissues from refractory epileptic patients, we found that LCM reduces the use-dependent GABA impairment (i.e., "rundown") that it is considered one of the specific hallmarks of drug-resistant epilepsies. Notably, in line with our clinical observations, we found that the co-treatment with subthreshold concentrations of LCM and LEV, which had no effect on GABAA currents on their own, reduced GABA impairment in drug-resistant epileptic patients, and this effect was blocked by PKC inhibitors. Our findings demonstrate, for the first time, that LCM targets GABAA receptors and that it can act synergistically with LEV, improving the GABAergic function. This novel mechanism might contribute to explain the clinical efficacy of LCM-LEV combination in several refractory epileptic patients.
Collapse
|
18
|
Ambrogini P, Albertini MC, Betti M, Galati C, Lattanzi D, Savelli D, Di Palma M, Saccomanno S, Bartolini D, Torquato P, Ruffolo G, Olivieri F, Galli F, Palma E, Minelli A, Cuppini R. Neurobiological Correlates of Alpha-Tocopherol Antiepileptogenic Effects and MicroRNA Expression Modulation in a Rat Model of Kainate-Induced Seizures. Mol Neurobiol 2018; 55:7822-7838. [PMID: 29468563 PMCID: PMC6132771 DOI: 10.1007/s12035-018-0946-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/31/2018] [Indexed: 12/19/2022]
Abstract
Seizure-triggered maladaptive neural plasticity and neuroinflammation occur during the latent period as a key underlying event in epilepsy chronicization. Previously, we showed that α-tocopherol (α-T) reduces hippocampal neuroglial activation and neurodegeneration in the rat model of kainic acid (KA)-induced status epilepticus (SE). These findings allowed us to postulate an antiepileptogenic potential for α-T in hippocampal excitotoxicity, in line with clinical evidence showing that α-T improves seizure control in drug-resistant patients. To explore neurobiological correlates of the α-T antiepileptogenic role, rats were injected with such vitamin during the latent period starting right after KA-induced SE, and the effects on circuitry excitability, neuroinflammation, neuronal death, and microRNA (miRNA) expression were investigated in the hippocampus. Results show that in α-T-treated epileptic rats, (1) the number of population spikes elicited by pyramidal neurons, as well as the latency to the onset of epileptiform-like network activity recover to control levels; (2) neuronal death is almost prevented; (3) down-regulation of claudin, a blood-brain barrier protein, is fully reversed; (4) neuroinflammation processes are quenched (as indicated by the decrease of TNF-α, IL-1β, GFAP, IBA-1, and increase of IL-6); (5) miR-146a, miR-124, and miR-126 expression is coherently modulated in hippocampus and serum by α-T. These findings support the potential of a timely intervention with α-T in clinical management of SE to reduce epileptogenesis, thus preventing chronic epilepsy development. In addition, we suggest that the analysis of miRNA levels in serum could provide clinicians with a tool to evaluate disease evolution and the efficacy of α-T therapy in SE.
Collapse
Affiliation(s)
- Patrizia Ambrogini
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy.
| | - Maria Cristina Albertini
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Michele Betti
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Claudia Galati
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Davide Lattanzi
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - David Savelli
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Michael Di Palma
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Stefania Saccomanno
- Department of Gastroenterology, Marche Polytechnic University, Ancona, Italy
| | - Desirée Bartolini
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Pierangelo Torquato
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - Fabiola Olivieri
- Department of Molecular and Clinical Sciences, Marche Polytechnic University, Ancona, Italy.,Center of Clinical Pathology and Innovative Therapy, INRCA-IRCCS, Ancona, Italy
| | - Francesco Galli
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome Sapienza, Rome, Italy
| | - Andrea Minelli
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| | - Riccardo Cuppini
- Department of Biomolecular Sciences, Section of Physiology, University of Urbino Carlo Bo, I-61029, Urbino, Italy
| |
Collapse
|
19
|
Gambardella A, Labate A, Cifelli P, Ruffolo G, Mumoli L, Aronica E, Palma E. Pharmacological modulation in mesial temporal lobe epilepsy: Current status and future perspectives. Pharmacol Res 2016; 113:421-425. [DOI: 10.1016/j.phrs.2016.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/13/2016] [Accepted: 09/17/2016] [Indexed: 11/29/2022]
|
20
|
Yang XY, Long LL, Xiao B. [Effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2016; 18:577-581. [PMID: 27412537 PMCID: PMC7388997 DOI: 10.7499/j.issn.1008-8830.2016.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/16/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To investigate the effects of temporal lobe epilepsy and idiopathic epilepsy on cognitive function and emotion in children and the risk factors for cognitive impairment. METHODS A retrospective analysis was performed for the clinical data of 38 children with temporal lobe epilepsy and 40 children with idiopathic epilepsy. The controls were 42 healthy children. All subjects received the following neuropsychological tests: Montreal Cognitive Assessment (MoCA) scale, verbal fluency test, digit span test, block design test, Social Anxiety Scale for Children (SASC), and Depression Self-rating Scale for Children (DSRSC). RESULTS Compared with the control group, the temporal lobe epilepsy and idiopathic epilepsy groups showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (P<0.05) and significantly higher scores on SASC and DSRSC (P<0.05). Compared with the idiopathic epilepsy group, the temporal lobe epilepsy group showed significantly lower scores of MoCA, verbal fluency, digit span, and block design (P<0.05) and significantly higher scores on SASC and DSRSC (P<0.05). In the temporal lobe epilepsy group, MoCA score was negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.571, -0.529, and -0.545 respectively; P<0.01). In the idiopathic epilepsy group, MoCA score was also negatively correlated with SASC score, DSRSC score, and seizure frequency (r=-0.542, -0.487, and -0.555 respectively; P<0.01). CONCLUSIONS Children with temporal lobe epilepsy and idiopathic epilepsy show impaired whole cognition, verbal fluency, memory, and executive function and have anxiety and depression, which are more significant in children with temporal lobe epilepsy. High levels of anxiety, depression, and seizure frequency are risk factors for impaired cognitive function.
Collapse
Affiliation(s)
- Xiao-Yan Yang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha 410008, China.
| | | | | |
Collapse
|
21
|
Barros-Barbosa AR, Fonseca AL, Guerra-Gomes S, Ferreirinha F, Santos A, Rangel R, Lobo MG, Correia-de-Sá P, Cordeiro JM. Up-regulation of P2X7 receptor-mediated inhibition of GABA uptake by nerve terminals of the human epileptic neocortex. Epilepsia 2015; 57:99-110. [PMID: 26714441 DOI: 10.1111/epi.13263] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2015] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Thirty percent of patients with epilepsy are refractory to medication. The majority of these patients have mesial temporal lobe epilepsy (MTLE). This prompts for new pharmacologic targets, like ATP-mediated signaling pathways, since the extracellular levels of the nucleotide dramatically increase during in vitro epileptic seizures. In this study, we investigated whether sodium-dependent high-affinity γ-aminobutyric acid (GABA) and glutamate uptake by isolated nerve terminals of the human neocortex could be modulated by ATP acting via slow-desensitizing P2X7 receptor (P2X7R). METHODS Modulation of [(3) H]GABA and [(14) C]glutamate uptake by ATP, through activation of P2X7R, was investigated in isolated nerve terminals of the neocortex of cadaveric controls and patients with drug-resistant epilepsy (non-MTLE or MTLE) submitted to surgery. Tissue density and distribution of P2X7R in the human neocortex was assessed by Western blot analysis and immunofluorescence confocal microscopy. RESULTS The P2X7R agonist, 2'(3')-O-(4-benzoylbenzoyl)ATP (BzATP, 3-100 μm) decreased [(3) H]GABA and [(14) C]glutamate uptake by nerve terminals of the neocortex of controls and patients with epilepsy. The inhibitory effect of BzATP (100 μm) was prevented by the selective P2X7R antagonist, A-438079 (3 μm). Down-modulation of [(14) C]glutamate uptake by BzATP (100 μm) was roughly similar in controls and patients with epilepsy, but the P2X7R agonist inhibited more effectively [(3) H]GABA uptake in the epileptic tissue. Neocortical nerve terminals of patients with epilepsy express higher amounts of the P2X7R protein than control samples. SIGNIFICANCE High-frequency cortical activity during epileptic seizures releases huge amounts of ATP, which by acting on low-affinity slowly desensitizing ionotropic P2X7R, leads to down-modulation of neuronal GABA and glutamate uptake. Increased P2X7R expression in neocortical nerve terminals of patients with epilepsy may, under high-frequency firing, endure GABA signaling and increase GABAergic rundown, thereby unbalancing glutamatergic neuroexcitation. This study highlights the relevance of the ATP-sensitive P2X7R as an important negative modulator of GABA and glutamate transport and prompts for novel antiepileptic therapeutic targets.
Collapse
Affiliation(s)
- Aurora R Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Ana L Fonseca
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Sónia Guerra-Gomes
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Agostinho Santos
- Serviço de Patologia Forense, Instituto Nacional de Medicina Legal e Ciências Forenses - Delegação do Norte (INMLCF-DN), Porto, Portugal
| | - Rui Rangel
- Serviço de Neurocirurgia, Centro Hospitalar do Porto - Hospital Geral de Santo António (CHP - HGSA), Porto, Portugal
| | - M Graça Lobo
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - J Miguel Cordeiro
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| |
Collapse
|
22
|
Roseti C, van Vliet EA, Cifelli P, Ruffolo G, Baayen JC, Di Castro MA, Bertollini C, Limatola C, Aronica E, Vezzani A, Palma E. GABAA currents are decreased by IL-1β in epileptogenic tissue of patients with temporal lobe epilepsy: implications for ictogenesis. Neurobiol Dis 2015; 82:311-320. [PMID: 26168875 DOI: 10.1016/j.nbd.2015.07.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 07/02/2015] [Accepted: 07/06/2015] [Indexed: 01/01/2023] Open
Abstract
Temporal lobe epilepsy (TLE) is the most prevalent form of adult focal onset epilepsy often associated with drug-resistant seizures. Numerous studies suggest that neuroinflammatory processes are pathologic hallmarks of both experimental and human epilepsy. In particular, the interleukin (IL)-1β/IL-1 receptor type 1 (R1) axis is activated in epileptogenic tissue, where it contributes significantly to the generation and recurrence of seizures in animal models. In this study, we investigated whether IL-1β affects the GABA-evoked currents (I(GABA)) in TLE tissue from humans. Given the limited availability of fresh human brain specimens, we used the "microtransplantation" method of injecting Xenopus oocytes with membranes from surgically resected hippocampal and cortical tissue from 21 patients with TLE and hippocampal sclerosis (HS), hippocampal tissue from five patients with TLE without HS, and autoptic and surgical brain specimens from 15 controls without epilepsy. We report the novel finding that pathophysiological concentrations of IL-1β decreased the I(GABA) amplitude by up to 30% in specimens from patients with TLE with or without HS, but not in control tissues. This effect was reproduced by patch-clamp recordings on neurons in entorhinal cortex slices from rats with chronic epilepsy, and was not observed in control slices. In TLE specimens from humans, the IL-1β effect was mediated by IL-1R1 and PKC. We also showed that IL-1R1 and IRAK1, the proximal kinase mediating the IL-1R1 signaling, are both up-regulated in the TLE compared with control specimens, thus supporting the idea that the IL-1β/IL-R1 axis is activated in human epilepsy. Our findings suggest a novel mechanism possibly underlying the ictogenic action of IL-1β, thus suggesting that this cytokine contributes to seizure generation in human TLE by reducing GABA-mediated neurotransmission.
Collapse
Affiliation(s)
| | - Erwin A van Vliet
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Pierangelo Cifelli
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy; Ri.MED Foundation, Palermo, Italy
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Johannes C Baayen
- Department of Neurosurgery, VU University Medical Center, Amsterdam, The Netherlands
| | - Maria Amalia Di Castro
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Cristina Bertollini
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, The Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN-Heemstede), The Netherlands
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy; IRCCS San Raffaele Pisana, Rome, Italy.
| |
Collapse
|
23
|
|
24
|
Soukupová M, Binaschi A, Falcicchia C, Zucchini S, Roncon P, Palma E, Magri E, Grandi E, Simonato M. Impairment of GABA release in the hippocampus at the time of the first spontaneous seizure in the pilocarpine model of temporal lobe epilepsy. Exp Neurol 2014; 257:39-49. [PMID: 24768627 DOI: 10.1016/j.expneurol.2014.04.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/27/2014] [Accepted: 04/16/2014] [Indexed: 01/03/2023]
Abstract
The alterations in GABA release have not yet been systematically measured along the natural course of temporal lobe epilepsy. In this work, we analyzed GABA extracellular concentrations (using in vivo microdialysis under basal and high K(+)-evoked conditions) and loss of two GABA interneuron populations (parvalbumin and somatostatin neurons) in the ventral hippocampus at different time-points after pilocarpine-induced status epilepticus in the rat, i.e. during development and progression of epilepsy. We found that (i) during the latent period between the epileptogenic insult, status epilepticus, and the first spontaneous seizure, basal GABA outflow was reduced to about one third of control values while the number of parvalbumin-positive cells was reduced by about 50% and that of somatostatin-positive cells by about 25%; nonetheless, high K(+) stimulation increased extracellular GABA in a proportionally greater manner during latency than under control conditions; (ii) at the time of the first spontaneous seizure (i.e., when the diagnosis of epilepsy is made in humans) this increased responsiveness to stimulation disappeared, i.e. there was no longer any compensation for GABA cell loss; (iii) thereafter, this dysfunction remained constant until a late phase of the disease. These data suggest that a GABAergic hyper-responsiveness can compensate for GABA cell loss and protect from occurrence of seizures during latency, whereas impaired extracellular GABA levels can favor the occurrence of spontaneous recurrent seizures and the maintenance of an epileptic state.
Collapse
Affiliation(s)
- Marie Soukupová
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy.
| | - Anna Binaschi
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy
| | - Chiara Falcicchia
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy
| | - Silvia Zucchini
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy; Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, Italy
| | - Paolo Roncon
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy
| | - Eleonora Palma
- Department of Physiology and Pharmacology University of Roma "Sapienza", Italy; IRCCS San Raffaele Pisana, Roma, Italy
| | - Eros Magri
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, University of Ferrara, Italy
| | - Enrico Grandi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, University of Ferrara, Italy
| | - Michele Simonato
- Department of Medical Sciences, Section of Pharmacology, Neuroscience Center, University of Ferrara, Italy; National Institute of Neuroscience, Italy; Laboratory of Technologies for Advanced Therapy (LTTA), Technopole of Ferrara, Italy
| |
Collapse
|
25
|
Roseti C, Fucile S, Lauro C, Martinello K, Bertollini C, Esposito V, Mascia A, Catalano M, Aronica E, Limatola C, Palma E. Fractalkine/CX3CL1 modulates GABAA currents in human temporal lobe epilepsy. Epilepsia 2013; 54:1834-44. [PMID: 24032743 DOI: 10.1111/epi.12354] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE The chemokine fractalkine/CX3CL1 and its receptor CX3CR1 are widely expressed in the central nervous system (CNS). Recent evidence showed that CX3CL1 participates in inflammatory responses that are common features of CNS disorders, such as epilepsy. Mesial temporal lobe epilepsy (MTLE) is the prevalent form of focal epilepsy in adults, and hippocampal sclerosis (HS) represents the most common underlying pathologic abnormality, as demonstrated at autopsy and postresection studies. Relevant features of MTLE are a characteristic pattern of neuronal loss, as are astrogliosis and microglia activation. Several factors affect epileptogenesis in patients with MTLE, including a lack of γ-aminobutyric acid (GABA)ergic inhibitory efficacy. Therefore, experiments were designed to investigate whether, in MTLE brain tissues, CX3CL1 may influence GABAA receptor (GABAA R) mediated transmission, with a particular focus on the action of CX3CL1 on the use-dependent decrease (rundown) of the GABA-evoked currents (IGABA ), a feature underlying the reduction of GABAergic function in epileptic tissue. METHODS Patch-clamp recordings were obtained from cortical pyramidal neurons in slices from six MTLE patients after surgery. Alternatively, the cell membranes from epileptic brain tissues of 17 MTLE patients or from surgical samples and autopsies of nonepileptic patients were microtransplanted into Xenopus oocytes, and IGABA were recorded using the standard two-microelectrode voltage-clamp technique. Immunohistochemical staining and double-labeling studies were carried out on the same brain tissues to analyze CX3CR1 expression. KEY FINDINGS In native pyramidal neurons from cortical slices of patients with MTLE, CX3CL1 reduced IGABA rundown and affected the recovery of IGABA amplitude from rundown. These same effects were confirmed in oocytes injected with cortical and hippocampal MTLE membranes, whereas CX3CL1 did not influence IGABA in oocytes injected with nonepileptic tissues. Consistent with a specific effect of CX3CL1 on tissues from patients with MTLE, CX3CR1 immunoreactivity was higher in MTLE sclerotic hippocampi than in control tissues, with a prominent expression in activated microglial cells. SIGNIFICANCE These findings indicate a role for CX3CL1 in MTLE, supporting recent evidence on the relevance of brain inflammation in human epilepsies. Our data demonstrate that in MTLE tissues the reduced GABAergic function can be modulated by CX3CL1. The increased CX3CR1 expression in microglia and the modulation by CX3CL1 of GABAergic currents in human epileptic brain suggests new therapeutic approaches for drug-resistant epilepsies based on the evidence that the propagation of seizures can be influenced by inflammatory processes.
Collapse
|
26
|
Chaumont S, André C, Perrais D, Boué-Grabot E, Taly A, Garret M. Agonist-dependent endocytosis of γ-aminobutyric acid type A (GABAA) receptors revealed by a γ2(R43Q) epilepsy mutation. J Biol Chem 2013; 288:28254-65. [PMID: 23935098 DOI: 10.1074/jbc.m113.470807] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GABA-gated chloride channels (GABAARs) trafficking is involved in the regulation of fast inhibitory transmission. Here, we took advantage of a γ2(R43Q) subunit mutation linked to epilepsy in humans that considerably reduces the number of GABAARs on the cell surface to better understand the trafficking of GABAARs. Using recombinant expression in cultured rat hippocampal neurons and COS-7 cells, we showed that receptors containing γ2(R43Q) were addressed to the cell membrane but underwent clathrin-mediated dynamin-dependent endocytosis. The γ2(R43Q)-dependent endocytosis was reduced by GABAAR antagonists. These data, in addition to a new homology model, suggested that a conformational change in the extracellular domain of γ2(R43Q)-containing GABAARs increased their internalization. This led us to show that endogenous and recombinant wild-type GABAAR endocytosis in both cultured neurons and COS-7 cells can be amplified by their agonists. These findings revealed not only a direct relationship between endocytosis of GABAARs and a genetic neurological disorder but also that trafficking of these receptors can be modulated by their agonist.
Collapse
Affiliation(s)
- Severine Chaumont
- From the Université Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), UMR 5287, F-33000 Bordeaux, France
| | | | | | | | | | | |
Collapse
|
27
|
Cifelli P, Palma E, Roseti C, Verlengia G, Simonato M. Changes in the sensitivity of GABAA current rundown to drug treatments in a model of temporal lobe epilepsy. Front Cell Neurosci 2013; 7:108. [PMID: 23874269 PMCID: PMC3708152 DOI: 10.3389/fncel.2013.00108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 06/21/2013] [Indexed: 01/26/2023] Open
Abstract
The pharmacological treatment of mesial temporal lobe epilepsy (mTLE), the most common epileptic syndrome in adults, is still unsatisfactory, as one-third of the patients are or become refractory to antiepileptic agents. Refractoriness may depend upon drug-induced alterations, but the disease per se may also undergo a progressive evolution that affects the sensitivity to drugs. mTLE has been shown to be associated with a dysfunction of the inhibitory signaling mediated by GABAA receptors. In particular, the repetitive activation of GABAA receptors produces a use-dependent decrease (rundown) of the evoked currents (IGABA), which is markedly enhanced in the hippocampus and cortex of drug-resistant mTLE patients. This phenomenon has been also observed in the pilocarpine model, where the increased IGABA rundown is observed in the hippocampus at the time of the first spontaneous seizure, then extends to the cortex and remains constant in the chronic phase of the disease. Here, we examined the sensitivity of IGABA to pharmacological modulation. We focused on the antiepileptic agent levetiracetam (LEV) and on the neurotrophin brain-derived neurotrophic factor (BDNF), which were previously reported to attenuate mTLE-induced increased rundown in the chronic human tissue. In the pilocarpine model, BDNF displayed a paramount effect, decreasing rundown in the hippocampus at the time of the first seizure, as well as in the hippocampus and cortex in the chronic period. In contrast, LEV did not affect rundown in the hippocampus, but attenuated it in the cortex. Interestingly, this effect of LEV was also observed on the still unaltered rundown observed in the cortex at the time of the first spontaneous seizure. These data suggest that the sensitivity of GABAA receptors to pharmacological interventions undergoes changes during the natural history of mTLE, implicating that the site of seizure initiation and the timing of treatment may highly affect the therapeutic outcome.
Collapse
Affiliation(s)
- Pierangelo Cifelli
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara Ferrara, Italy ; National Institute of Neuroscience Ferrara, Italy ; Ri.MED Foundation Palermo, Italy
| | | | | | | | | |
Collapse
|
28
|
Diógenes MJ, Neves-Tomé R, Fucile S, Martinello K, Scianni M, Theofilas P, Lopatár J, Ribeiro JA, Maggi L, Frenguelli BG, Limatola C, Boison D, Sebastião AM. Homeostatic control of synaptic activity by endogenous adenosine is mediated by adenosine kinase. Cereb Cortex 2012; 24:67-80. [PMID: 22997174 DOI: 10.1093/cercor/bhs284] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Extracellular adenosine, a key regulator of neuronal excitability, is metabolized by astrocyte-based enzyme adenosine kinase (ADK). We hypothesized that ADK might be an upstream regulator of adenosine-based homeostatic brain functions by simultaneously affecting several downstream pathways. We therefore studied the relationship between ADK expression, levels of extracellular adenosine, synaptic transmission, intrinsic excitability, and brain-derived neurotrophic factor (BDNF)-dependent synaptic actions in transgenic mice underexpressing or overexpressing ADK. We demonstrate that ADK: 1) Critically influences the basal tone of adenosine, evaluated by microelectrode adenosine biosensors, and its release following stimulation; 2) determines the degree of tonic adenosine-dependent synaptic inhibition, which correlates with differential plasticity at hippocampal synapses with low release probability; 3) modulates the age-dependent effects of BDNF on hippocampal synaptic transmission, an action dependent upon co-activation of adenosine A2A receptors; and 4) influences GABAA receptor-mediated currents in CA3 pyramidal neurons. We conclude that ADK provides important upstream regulation of adenosine-based homeostatic function of the brain and that this mechanism is necessary and permissive to synaptic actions of adenosine acting on multiple pathways. These mechanistic studies support previous therapeutic studies and implicate ADK as a promising therapeutic target for upstream control of multiple neuronal signaling pathways crucial for a variety of neurological disorders.
Collapse
|
29
|
Conti L, Palma E, Roseti C, Lauro C, Cipriani R, de Groot M, Aronica E, Limatola C. Anomalous levels of Cl- transporters cause a decrease of GABAergic inhibition in human peritumoral epileptic cortex. Epilepsia 2011; 52:1635-44. [PMID: 21635237 DOI: 10.1111/j.1528-1167.2011.03111.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Several factors contribute to epileptogenesis in patients with brain tumors, including reduced γ-aminobutyric acid (GABA)ergic inhibition. In particular, changes in Cl(-) homeostasis in peritumoral microenvironment, together with alterations of metabolism, are key processes leading to epileptogenesis in patients afflicted by glioma. It has been recently proposed that alterations of Cl(-) homeostasis could be involved in tumor cell migration and metastasis formation. In neurons, the regulation of intracellular Cl(-) concentration ([Cl(-) ](i) ) is mediated by NKCC1 and KCC2 transporters: NKCC1 increases while KCC2 decreases [Cl(-) ](i) . Experiments were thus designed to investigate whether, in human epileptic peritumoral cortex, alterations in the balance of NKCC1 and KCC2 activity may decrease the hyperpolarizing effects of GABA, thereby contributing to epileptogenesis in human brain tumors. METHODS Membranes from peritumoral cortical tissues of epileptic patients afflicted by gliomas (from II to IV WHO grade) and from cortical tissues of nonepileptic patients were injected into Xenopus oocytes leading to the incorporation of functional GABA(A) receptors. The GABA-evoked currents were recorded using standard two-microelectrode voltage-clamp technique. In addition, immunoblot analysis and immunohistochemical staining were carried out on membranes and tissues from the same patients. KEY FINDINGS We found that in oocytes injected with epileptic peritumoral cerebral cortex, the GABA-evoked currents had a more depolarized reversal potential (E(GABA) ) compared to those from nonepileptic healthy cortex. This difference of E(GABA) was abolished by the NKCC1 blocker bumetanide or unblocking of KCC2 with the Zn(2+) chelator TPEN. Moreover, Western blot analysis revealed an increased expression of NKCC1, and more modestly, of KCC2 transporters in epileptic peritumoral tissues compared to nonepileptic control tissues. In addition, NKCC1 immunoreactivity was strongly increased in peritumoral cortex with respect to nonepileptic cortex, with a prominent expression in neuronal cells. SIGNIFICANCE We report that the positive shift of E(GABA) in epileptic peritumoral human cortex is due to an altered expression of NKCC1 and KCC2, perturbing Cl(-) homeostasis, which might lead to a consequent reduction in GABAergic inhibition. These findings point to a key role of Cl(-) transporters KCC2 and NKCC1 in tumor-related epilepsy, suggesting a more specific drug therapy and surgical approaches for the epileptic patients afflicted by brain tumors.
Collapse
Affiliation(s)
- Luca Conti
- Pasteur Institute-Cenci Bolognetti Foundation, Department of Physiology and Pharmacology, University of Rome La Sapienza, Rome, Italy
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Li G, Yang K, Zheng C, Liu Q, Chang Y, Kerrigan JF, Wu J. Functional rundown of gamma-aminobutyric acid(A) receptors in human hypothalamic hamartomas. Ann Neurol 2011; 69:664-72. [PMID: 21391233 DOI: 10.1002/ana.22298] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 08/23/2010] [Accepted: 09/17/2010] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Human hypothalamic hamartomas (HHs) are highly associated with treatment-resistant gelastic seizures. HHs are intrinsically epileptogenic, although the basic cellular mechanisms responsible for seizure activity are unknown. Altered gamma-aminobutyric acid (GABA) function can contribute to epileptogenesis in humans and animal models. Recently, functional GABA(A) receptor (GABA(A) R) rundown has been described in surgically resected human temporal lobe epilepsy tissue. We asked whether functional GABA(A) R rundown also occurs in human HH neurons. METHODS GABA(A) R-mediated currents were measured using perforated patch-clamp recordings in single neurons acutely dissociated from surgically resected HH tissue. In addition, functional GABA(A) Rs were expressed in Xenopus oocytes after microinjection with membrane fractions from either HH or control hypothalamus, and were studied with 2-electrode voltage-clamp recordings. RESULTS Perforated patch-clamp recordings in dissociated HH neurons showed that repetitive exposure to GABA (5 consecutive exposures to 0.1 mM GABA with 1-second duration and at 20-second intervals) induced a time-dependent rundown of whole-cell currents in small HH neurons, whereas large HH neurons showed much less rundown using the same protocol. Functional rundown was not observed in HH neurons with repetitive exposure to glycine or glutamate. Two-electrode voltage-clamp recordings (6 consecutive exposures to 1 mM GABA with 10-second duration and at 40-second intervals) induced GABA current rundown in Xenopus oocytes microinjected with HH membrane proteins, but not in the oocytes expressing hypothalamic membrane proteins derived from human autopsy controls. Functional rundown of GABA currents was significantly attenuated by intracellular application of adenosine triphosphate or the nonspecific phosphatase inhibitor, okadaic acid. INTERPRETATION Neurons from surgically resected human HH demonstrate functional rundown of GABA(A) R-mediated transmembrane currents in response to GABA agonist exposure. Rundown may be a marker for impaired GABAergic function and a contributing mechanism for seizure genesis within HH tissue.
Collapse
Affiliation(s)
- Guohui Li
- Division of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Jin X, Huguenard JR, Prince DA. Reorganization of inhibitory synaptic circuits in rodent chronically injured epileptogenic neocortex. Cereb Cortex 2010; 21:1094-104. [PMID: 20855494 DOI: 10.1093/cercor/bhq181] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reduced synaptic inhibition is an important factor contributing to posttraumatic epileptogenesis. Axonal sprouting and enhanced excitatory synaptic connectivity onto rodent layer V pyramidal (Pyr) neurons occur in epileptogenic partially isolated (undercut) neocortex. To determine if enhanced excitation also affects inhibitory circuits, we used laser scanning photostimulation of caged glutamate and whole-cell recordings from GAD67-GFP-expressing mouse fast spiking (FS) interneurons and Pyr cells in control and undercut in vitro slices to map excitatory and inhibitory synaptic inputs. Results are 1) the region-normalized excitatory postsynaptic current (EPSC) amplitudes and proportion of uncaging sites from which EPSCs could be evoked (hotspot ratio) "increased" significantly in FS cells of undercut slices; 2) in contrast, these parameters were significantly "decreased" for inhibitory postsynaptic currents (IPSCs) in undercut FS cells; and 3) in rat layer V Pyr neurons, we found significant decreases in IPSCs in undercut versus control Pyr neurons. The decreases were mainly located in layers II and IV, suggesting a reduction in the efficacy of interlaminar synaptic inhibition. Results suggest that there is significant synaptic reorganization in this model of posttraumatic epilepsy, resulting in increased excitatory drive and reduced inhibitory input to FS interneurons that should enhance their inhibitory output and, in part, offset similar alterations in innervation of Pyr cells.
Collapse
Affiliation(s)
- Xiaoming Jin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | | |
Collapse
|
32
|
Janigro D. Inhibitory GABA current rundown in epileptic brain: use-dependent and pathology-specific mechanisms. Epilepsy Curr 2010; 6:138-9. [PMID: 17260038 PMCID: PMC1783430 DOI: 10.1111/j.1535-7511.2006.00124.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Rundown of GABA Type A Receptors Is a Dysfunction Associated with Human Drug-Resistant Mesial Temporal Lobe Epilepsy Ragozzino D, Palma E, Di Angelantonio S, Amici M, Mascia A, Arcella A, Giangaspero F, Cantore G, Di Gennaro G, Manfredi M, Esposito V, Quarato PP, Miledi R, Eusebi F Proc Natl Acad Sci U S A 2005;102(42):15219–15223 Pharmacotherapeutic strategies have been difficult to develop for several forms of temporal lobe epilepsy, which are consequently treated by surgical resection. To examine this problem, we have studied the properties of transmitter receptors of tissues removed during surgical treatment. We find that when cell membranes, isolated from the temporal neocortex of patients afflicted with drug-resistant mesial temporal lobe epilepsy (TLE), are injected into frog oocytes they acquire GABA type A receptors (GABAA-receptors) that display a marked rundown during repetitive applications of GABA. In contrast, GABAA-receptor function is stable in oocytes injected with cell membranes isolated from the temporal lobe of TLE patients afflicted with neoplastic, dysgenetic, traumatic, or ischemic temporal lesions (lesional TLE, LTLE). Use-dependent GABAA-receptor rundown is also found in the pyramidal neurons of TLE neocortical slices and is antagonized by BDNF. Pyramidal neurons in cortical slices of a traumatic LTLE patient did not show GABAA-receptor rundown. However, the apparent affinity of GABAA-receptor in oocytes microtransplanted with membranes from all of the epileptic patients studied was smaller than the affinity of receptors transplanted from the nonepileptic brain. We conclude that the use-dependent rundown of neocortical GABAA-receptor represents a TLE-specific dysfunction, whereas the reduced affinity may be a general feature of brains of both TLE and LTLE patients, and we speculate that our findings may help to develop new treatments for TLE and LTLE.
Collapse
|
33
|
Granata T, Marchi N, Carlton E, Ghosh C, Gonzalez-Martinez J, Alexopoulos AV, Janigro D. Management of the patient with medically refractory epilepsy. Expert Rev Neurother 2010; 9:1791-802. [PMID: 19951138 DOI: 10.1586/ern.09.114] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Epilepsy imposes a significant clinical, epidemiologic and economic burden on societies throughout the world. Despite the development of more than ten new antiepileptic drugs over the past 15 years, approximately a third of patients with epilepsy remain resistant to pharmacotherapy. Individuals who fail to respond, or respond only partially, continue to have incapacitating seizures. Managing patients with medically refractory epilepsy is challenging and requires a structured multidisciplinary approach in specialized clinics. If the problems related to drug resistance could be resolved, even in part, by improving the pharmacokinetic profile of existing drugs, the economic savings would be remarkable and the time required to design drugs that achieve seizure control would be shorter than the discovery of new targets and molecules was required. A promising approach is the use of corticosteroids that may have a dual beneficial effect. Resective brain surgery remains the ultimate and highly successful approach to multiple drug resistance in epileptic patients.
Collapse
Affiliation(s)
- Tiziana Granata
- Department of Neurology, Cleveland, OH, USA and Department of Child Neurology, Carlo Besta Neurological Institute, Milan, Italy.
| | | | | | | | | | | | | |
Collapse
|
34
|
Enhancement of GABA(A)-current run-down in the hippocampus occurs at the first spontaneous seizure in a model of temporal lobe epilepsy. Proc Natl Acad Sci U S A 2010; 107:3180-5. [PMID: 20133704 DOI: 10.1073/pnas.0914710107] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Refractory temporal lobe epilepsy (TLE) is associated with a dysfunction of inhibitory signaling mediated by GABA(A) receptors. In particular, the use-dependent decrease (run-down) of the currents (I(GABA)) evoked by the repetitive activation of GABA(A) receptors is markedly enhanced in hippocampal and cortical neurons of TLE patients. Understanding the role of I(GABA) run-down in the disease, and its mechanisms, may allow development of medical alternatives to surgical resection, but such mechanistic insights are difficult to pursue in surgical human tissue. Therefore, we have used an animal model (pilocarpine-treated rats) to identify when and where the increase in I(GABA) run-down occurs in the natural history of epilepsy. We found: (i) that the increased run-down occurs in the hippocampus at the time of the first spontaneous seizure (i.e., when the diagnosis of epilepsy is made), and then extends to the neocortex and remains constant in the course of the disease; (ii) that the phenomenon is strictly correlated with the occurrence of spontaneous seizures, because it is not observed in animals that do not become epileptic. Furthermore, initial exploration of the molecular mechanism disclosed a relative increase in alpha4-, relative to alpha1-containing GABA(A) receptors, occurring at the same time when the increased run-down appears, suggesting that alterations in the molecular composition of the GABA receptors may be responsible for the occurrence of the increased run-down. These observations disclose research opportunities in the field of epileptogenesis that may lead to a better understanding of the mechanism whereby a previously normal tissue becomes epileptic.
Collapse
|
35
|
Blockage of A2A and A3 adenosine receptors decreases the desensitization of human GABA(A) receptors microtransplanted to Xenopus oocytes. Proc Natl Acad Sci U S A 2009; 106:15927-31. [PMID: 19721003 DOI: 10.1073/pnas.0907324106] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We previously found that the endogenous anticonvulsant adenosine, acting through A(2A) and A(3) adenosine receptors (ARs), alters the stability of currents (I(GABA)) generated by GABA(A) receptors expressed in the epileptic human mesial temporal lobe (MTLE). Here we examined whether ARs alter the stability (desensitization) of I(GABA) expressed in focal cortical dysplasia (FCD) and in periglioma epileptic tissues. The experiments were performed with tissues from 23 patients, using voltage-clamp recordings in Xenopus oocytes microinjected with membranes isolated from human MTLE and FCD tissues or using patch-clamp recordings of pyramidal neurons in epileptic tissue slices. On repetitive activation, the epileptic GABA(A) receptors revealed instability, manifested by a large I(GABA) rundown, which in most of the oocytes (approximately 70%) was obviously impaired by the new A(2A) antagonists ANR82, ANR94, and ANR152. In most MTLE tissue-microtransplanted oocytes, a new A(3) receptor antagonist (ANR235) significantly improved I(GABA) stability. Moreover, patch-clamped pyramidal neurons from human neocortical slices of periglioma epileptic tissues exhibited altered I(GABA) rundown on ANR94 treatment. Our findings indicate that antagonizing A(2A) and A(3) receptors increases the I(GABA) stability in different epileptic tissues and suggest that adenosine derivatives may offer therapeutic opportunities in various forms of human epilepsy.
Collapse
|
36
|
Microtransplantation of ligand-gated receptor-channels from fresh or frozen nervous tissue into Xenopus oocytes: A potent tool for expanding functional information. Prog Neurobiol 2009; 88:32-40. [DOI: 10.1016/j.pneurobio.2009.01.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 12/21/2008] [Accepted: 01/29/2009] [Indexed: 02/05/2023]
|
37
|
Thompson K. Transplantation of GABA-producing cells for seizure control in models of temporal lobe epilepsy. Neurotherapeutics 2009; 6:284-94. [PMID: 19332321 PMCID: PMC5084205 DOI: 10.1016/j.nurt.2009.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 01/20/2009] [Accepted: 01/22/2009] [Indexed: 11/27/2022] Open
Abstract
A high percentage of patients with temporal lobe epilepsy (TLE) are refractory to conventional pharmacotherapy. The progressive neurodegenerative processes associated with a lifetime of uncontrolled seizures mandate the development of alternative approaches to treat this disease. Transplantation of inhibitory cells has been suggested as a potential therapeutic strategy to achieve seizure suppression in humans with intractable TLE. Preclinical investigations over 20 years have demonstrated that multiple cell types from several sources can produce anticonvulsant, and antiepileptogenic, effects in animal models of TLE. Transplanting GABA-producing cells, in particular, has been shown to reduce seizures in several well-established models. This review addresses experimentation using different sources of transplantable GABAergic cells, highlighting progress with fetal tissue, neural cell lines, and stem cells. Regardless of the source of the GABAergic cells used in seizure studies, common challenges have emerged. Several variables influence the anticonvulsant potential of GABA-producing cells. For example, tissue availability, graft survival, immunogenicity, tumorigenicity, and varying levels of cell migration, differentiation, and integration into functional circuits and the microenvironment provided by sclerotic tissue all contribute to the efficacy of transplanted cells. The challenge of understanding how all of these variables work in concert, in a disease process that has no well-established etiology, suggests that there is still much basic research to be done before rational cell-based therapies can be developed for TLE.
Collapse
Affiliation(s)
- Kerry Thompson
- Department of Biology, Occidental College, Los Angeles, California 90041, USA.
| |
Collapse
|
38
|
Bernhardt BC, Worsley KJ, Kim H, Evans AC, Bernasconi A, Bernasconi N. Longitudinal and cross-sectional analysis of atrophy in pharmacoresistant temporal lobe epilepsy. Neurology 2009; 72:1747-54. [PMID: 19246420 DOI: 10.1212/01.wnl.0000345969.57574.f5] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Whether recurrent epileptic seizures induce brain damage is debated. Disease progression in epilepsy has been evaluated only in a few community-based studies involving patients with seizures well controlled by medication. These studies concluded that epilepsy does not inevitably lead to global cerebral damage. OBJECTIVE To track the progression of neocortical atrophy in pharmacoresistant temporal lobe epilepsy (TLE) using longitudinal and cross-sectional designs. METHODS Using a fully automated measure of cortical thickness on MRI, we studied a homogeneous sample of patients with pharmacoresistant TLE. In the longitudinal analysis (n = 18), fixed-effect models were used to quantify cortical atrophy over a mean interscan interval of 2.5 years (range = 7 to 90 months). In the cross-sectional analysis (n = 121), we correlated epilepsy duration and thickness. To dissociate normal aging from pathologic progression, we compared aging effects in TLE to healthy controls. RESULTS The longitudinal analysis mapped progression in ipsilateral temporopolar and central and contralateral orbitofrontal, insular, and angular regions. In patients with more than 14 years of disease, atrophy progressed more rapidly in frontocentral and parietal regions that in those with shorter duration. The cross-sectional study showed progressive atrophy in the mesial and superolateral frontal, and parietal cortices. CONCLUSIONS Our combined cross-sectional and longitudinal analysis in patients with pharmacoresistant temporal lobe epilepsy demonstrated progressive neocortical atrophy over a mean interval of 2.5 years that is distinct from normal aging, likely representing seizure-induced damage. The cumulative character of atrophy underlies the importance of early surgical treatment in this group of patients.
Collapse
Affiliation(s)
- B C Bernhardt
- Department of Neurology, Montreal Neurological Institute and Hospital, McGill University, Quebec, Canada
| | | | | | | | | | | |
Collapse
|
39
|
Abstract
Voltage-clamp techniques are typically used to study the plasma membrane proteins, such as ion channels and transporters that control bioelectrical signals. Many of these proteins have been cloned and can now be studied as potential targets for drug development. The two approaches most commonly used for heterologous expression of cloned ion channels and transporters involve either transfection of the genes into small cells grown in tissue culture or the injection of the genetic material into larger cells. The standard large cells used for the expression of cloned cDNA or synthetic RNA are the egg progenitor cells (oocytes) of the African frog, Xenopus laevis. Until recently, cellular electrophysiology was performed manually by a single operator, one cell at a time. However, methods of high throughput electrophysiology have been developed which are automated and permit data acquisition and analysis from multiple cells in parallel. These methods are breaking a bottleneck in drug discovery, useful in some cases for primary screening as well as for thorough characterization of new drugs. Increasing throughput of high-quality functional data greatly augments the efficiency of academic research and pharmaceutical drug development. Some examples of studies that benefit most from high throughput electrophysiology include pharmaceutical screening of targeted compound libraries, secondary screening of identified compounds for subtype selectivity, screening mutants of ligand-gated channels for changes in receptor function, scanning mutagenesis of protein segments, and mutant-cycle analysis. We describe here the main features and potential applications of OpusXpress, an efficient commercially available system for automated recording from Xenopus oocytes. We show some types of data that have been gathered by this system and review realized and potential applications.
Collapse
Affiliation(s)
- Roger L Papke
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida, USA.
| | | |
Collapse
|
40
|
Roseti C, Martinello K, Fucile S, Piccari V, Mascia A, Di Gennaro G, Quarato PP, Manfredi M, Esposito V, Cantore G, Arcella A, Simonato M, Fredholm BB, Limatola C, Miledi R, Eusebi F. Adenosine receptor antagonists alter the stability of human epileptic GABAA receptors. Proc Natl Acad Sci U S A 2008; 105:15118-23. [PMID: 18809912 PMCID: PMC2567502 DOI: 10.1073/pnas.0807277105] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2008] [Indexed: 12/26/2022] Open
Abstract
We examined how the endogenous anticonvulsant adenosine might influence gamma-aminobutyric acid type A (GABA(A)) receptor stability and which adenosine receptors (ARs) were involved. Upon repetitive activation (GABA 500 microM), GABA(A) receptors, microtransplanted into Xenopus oocytes from neurosurgically resected epileptic human nervous tissues, exhibited an obvious GABA(A)-current (I(GABA)) run-down, which was consistently and significantly reduced by treatment with the nonselective adenosine receptor antagonist CGS15943 (100 nM) or with adenosine deaminase (ADA) (1 units/ml), that inactivates adenosine. It was also found that selective antagonists of A2B (MRS1706, 10 nM) or A3 (MRS1334, 30 nM) receptors reduced I(GABA) run-down, whereas treatment with the specific A1 receptor antagonist DPCPX (10 nM) was ineffective. The selective A2A receptor antagonist SCH58261 (10 nM) reduced or potentiated I(GABA) run-down in approximately 40% and approximately 20% of tested oocytes, respectively. The ADA-resistant, AR agonist 2-chloroadenosine (2-CA) (10 microM) potentiated I(GABA) run-down but only in approximately 20% of tested oocytes. CGS15943 administration again decreased I(GABA) run-down in patch-clamped neurons from either human or rat neocortex slices. I(GABA) run-down in pyramidal neurons was equivalent in A1 receptor-deficient and wt neurons but much larger in neurons from A2A receptor-deficient mice, indicating that, in mouse cortex, GABA(A)-receptor stability is tonically influenced by A2A but not by A1 receptors. I(GABA) run-down from wt mice was not affected by 2-CA, suggesting maximal ARs activity by endogenous adenosine. Our findings strongly suggest that cortical A2-A3 receptors alter the stability of GABA(A) receptors, which could offer therapeutic opportunities.
Collapse
Affiliation(s)
- Cristina Roseti
- *Istituto Pasteur–Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza di Biologia e Medicina Molecolare, Università di Roma “La Sapienza”, Piazzale A. Moro 5, I-00185 Rome, Italy
| | | | - Sergio Fucile
- *Istituto Pasteur–Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza di Biologia e Medicina Molecolare, Università di Roma “La Sapienza”, Piazzale A. Moro 5, I-00185 Rome, Italy
- Neuromed I.R.C.C.S., Via Atinese 18, I-86077 Isernia, Italy
| | - Vanessa Piccari
- *Istituto Pasteur–Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza di Biologia e Medicina Molecolare, Università di Roma “La Sapienza”, Piazzale A. Moro 5, I-00185 Rome, Italy
- Neuromed I.R.C.C.S., Via Atinese 18, I-86077 Isernia, Italy
| | | | | | | | - Mario Manfredi
- Neuromed I.R.C.C.S., Via Atinese 18, I-86077 Isernia, Italy
| | | | | | | | - Michele Simonato
- Department of Clinical and Experimental Medicine, Section of Pharmacology, Neuroscience Center, University of Ferrara and National Institute of Neuroscience, I-44100 Ferrara, Italy
| | - Bertil B. Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77 Stockholm, Sweden
| | - Cristina Limatola
- *Istituto Pasteur–Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza di Biologia e Medicina Molecolare, Università di Roma “La Sapienza”, Piazzale A. Moro 5, I-00185 Rome, Italy
- Neuromed I.R.C.C.S., Via Atinese 18, I-86077 Isernia, Italy
| | - Ricardo Miledi
- **Instituto de Neurobiología, Campus UNAM-Juriquilla, Universidad Nacional Autónoma de México, AP1-1141 Querétaro, Mexico; and
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4550
| | - Fabrizio Eusebi
- *Istituto Pasteur–Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza di Biologia e Medicina Molecolare, Università di Roma “La Sapienza”, Piazzale A. Moro 5, I-00185 Rome, Italy
- Neuromed I.R.C.C.S., Via Atinese 18, I-86077 Isernia, Italy
| |
Collapse
|
41
|
Mapping limbic network organization in temporal lobe epilepsy using morphometric correlations: Insights on the relation between mesiotemporal connectivity and cortical atrophy. Neuroimage 2008; 42:515-24. [DOI: 10.1016/j.neuroimage.2008.04.261] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 04/25/2008] [Accepted: 04/26/2008] [Indexed: 11/20/2022] Open
|
42
|
Jansen LA, Peugh LD, Ojemann JG. GABA(A) receptor properties in catastrophic infantile epilepsy. Epilepsy Res 2008; 81:188-97. [PMID: 18650066 DOI: 10.1016/j.eplepsyres.2008.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 05/28/2008] [Accepted: 05/30/2008] [Indexed: 10/21/2022]
Abstract
Catastrophic epilepsy due to cortical dysplasia is often intractable to anticonvulsant treatment. Many of the medications used unsuccessfully in treating this disorder are thought to exert at least a portion of their action through enhancement of inhibitory GABA(A) neurotransmission. In the present study, GABA(A) receptor properties in resected brain tissue from four infants with infantile spasms and intractable epilepsy due to cortical dysplasia were measured to determine if this clinical resistance to pharmacologic treatment correlates with alterations in receptor function. Results from epileptic cortex were compared with those from autopsy control samples. To perform these studies, we utilized the technique of injection of brain cellular membrane preparations into the Xenopus oocyte, which results in the incorporation of human GABA(A) receptors in their native configuration into the oocyte plasma membrane. Two-electrode voltage-clamp electrophysiology analysis was then performed to assess GABA(A) receptor pharmacologic properties. The intrinsic properties of affinity, reversal potential, current decay, and current rundown were unchanged in the epileptic infants. Current enhancement by benzodiazepines was also unaltered, as was the response to barbiturates. However, a significant decrease was found in the degree of GABA(A) current enhancement by neurosteroids in the epileptic infants, along with an increase in current inhibition by zinc. These findings may contribute to the mechanisms of intractability in catastrophic infantile epilepsy due to cortical dysplasia, and suggest alternative therapeutic approaches.
Collapse
Affiliation(s)
- Laura A Jansen
- Seattle Children's Hospital Research Institute, University of Washington, Division of Pediatric Neurology, 1900 Ninth Avenue, 8th Floor, Seattle, WA 98101, United States.
| | | | | |
Collapse
|
43
|
Microtransplantation of neurotransmitter receptors from postmortem autistic brains to Xenopus oocytes. Proc Natl Acad Sci U S A 2008; 105:10973-7. [PMID: 18645182 DOI: 10.1073/pnas.0804386105] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Autism is a complex disorder that arises from the pervasive action of genetic and epigenetic factors that alter synaptic connectivity of the brain. Although GABA and glutamate receptors seem to be two of those factors, very little is known about the functional properties of the autistic receptors. Autistic tissue samples stored in brain banks usually have relatively long postmortem times, and it is highly desirable to know whether neurotransmitter receptors in such tissues are still functional. Here we demonstrate that native receptors microtransplanted from autistic brains, as well as de novo mRNA-expressed receptors, are still functional and susceptible to detailed electrophysiological characterization even after long postmortem intervals. The opportunity to study the properties of human receptors present in diseased brains not only opens new avenues toward understanding autism and other neurological disorders, but it also makes the microtransplantation method a useful translational system to evaluate and develop novel medicinal drugs.
Collapse
|
44
|
GABA(A)-current rundown of temporal lobe epilepsy is associated with repetitive activation of GABA(A) "phasic" receptors. Proc Natl Acad Sci U S A 2007; 104:20944-8. [PMID: 18083839 DOI: 10.1073/pnas.0710522105] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A study was made of the "rundown" of GABA(A) receptors, microtransplanted to Xenopus oocytes from surgically resected brain tissues of patients afflicted with drug-resistant human mesial temporal lobe epilepsy (mTLE). Cell membranes, isolated from mTLE neocortex specimens, were injected into frog oocytes that rapidly incorporated functional GABA(A) receptors. Upon repetitive activation with GABA (1 mM), "epileptic" GABA(A) receptors exhibited a GABA(A)-current (I(GABA)) rundown that was significantly enhanced by Zn(2+) (</=250 microM), and practically abolished by the high-affinity GABA(A) receptor inverse agonist SR95531 (gabazine; 2.5-25 microM). Conversely, I(GABA) generated by "control" GABA(A) receptors microtransplanted from nonepileptic temporal lobe, lesional TLE, or authoptic disease-free tissues remained stable during repetitive stimulation, even in oocytes treated with Zn(2+). We conclude that rundown of mTLE epileptic receptors depends on the presence of "phasic GABA(A) receptors" that have low sensitivity to antagonism by Zn(2+). Additionally, we found that GABA(A) receptors, microtransplanted from the cerebral cortex of adult rats exhibiting recurrent seizures, caused by pilocarpine-induced status epilepticus, showed greater rundown than control tissue, an event also occurring in patch-clamped rat pyramidal neurons. Rundown of epileptic rat receptors resembled that of human mTLE receptors, being enhanced by Zn(2+) (40 microM) and sensitive to the antiepileptic agent levetiracetam, the neurotrophin brain-derived neurotrophic factor, and the phosphatase blocker okadaic acid. Our findings point to the rundown of GABA(A) receptors as a hallmark of TLE and suggest that modulating tonic and phasic mTLE GABA(A) receptor activity may represent a useful therapeutic approach to the disease.
Collapse
|
45
|
Palma E, Ragozzino D, Di Angelantonio S, Mascia A, Maiolino F, Manfredi M, Cantore G, Esposito V, Di Gennaro G, Quarato P, Miledi R, Eusebi F. The Antiepileptic Drug Levetiracetam Stabilizes the Human Epileptic GABAAReceptors upon Repetitive Activation. Epilepsia 2007; 48:1842-9. [PMID: 17521347 DOI: 10.1111/j.1528-1167.2007.01131.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE GABAA receptors from the brain of patients afflicted with mesial temporal lobe epilepsy (MTLE) become less efficient (run-down) when repetitively activated by GABA. Experiments were designed to investigate whether the antiepileptic drug, levetiracetam (LEV), which is used as an adjunctive treatment for medically intractable MTLE, counteracts the GABAA receptor run-down. METHODS GABAA receptors were microtransplanted from the brains of patients afflicted with MTLE into Xenopus oocytes. The GABA-current run-down, caused by repetitive applications of GABA, was investigated using the standard two-microelectrode voltage-clamp technique. Additionally, the GABA-current run-down was investigated directly on pyramidal neurons in human MTLE cortical slices. RESULTS It was found that, in oocytes injected with membranes isolated from the MTLE neocortex, the GABA-current run-down was inhibited by a 3-h pretreatment with 0.5-100 microM LEV. Moreover, the GABAA receptors of pyramidal neurons in human neocortical slices exhibited a current run-down that was significantly reduced by 1 microM LEV. Interestingly, the run-down in oocytes injected with membranes isolated from the MTLE hippocampal subiculum was not affected by LEV. CONCLUSIONS We report that the antiepileptic LEV strengthens GABA inhibition of neuronal circuits by blocking the receptor run-down in the cortex whilst leaving the run-down of GABAA receptors in the hippocampal subiculum unaltered. These findings point to the GABAA receptor run-down as an important event in epileptogenesis and as a possible target for testing and screening antiepileptic drugs.
Collapse
Affiliation(s)
- Eleonora Palma
- Dipartimento di Fisiologia Umana e Farmacologia, Universita' di Roma La Sapienza, Roma, Italy.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Zhao C, Xu Z, Chen J, Yu Z, Tong KL, Lo WS, Pun FW, Ng SK, Tsang SY, Xue H. Two isoforms of GABA(A) receptor beta2 subunit with different electrophysiological properties: Differential expression and genotypical correlations in schizophrenia. Mol Psychiatry 2006; 11:1092-105. [PMID: 16983389 DOI: 10.1038/sj.mp.4001899] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Single nucleotide polymorphisms in type A gamma-aminobutyric acid (GABA(A)) receptor beta2 subunit gene (GABRB2) were found to be associated with schizophrenia in Chinese, German, Japanese and Portuguese. To explore potential functional consequences of these DNA sequence polymorphisms, this study examined the expression and electrophysiological properties of two alternatively spliced products of GABRB2 along with genotypical disease association analysis. Real-time quantitative polymerase chain reaction, performed with a cohort of 31 schizophrenics and 31 controls of US population, showed 21.7% reduction in the expression of the long isoform beta(2L), 13.4% in the short isoform beta(2S) and 15.8% in the sum of the two isoforms beta(2T) in postmortem schizophrenic brain. Furthermore, two independent mRNA quantitation methods showed that the relative expression of the long over the short isoforms was significantly decreased, suggesting the occurrence of altered splicing, in schizophrenia. In male schizophrenics, the heterozygous genotypes of rs1876071 (T/C) and rs1876072 (A/G) were correlated with reduced expression of beta(2L), beta(2S) and beta(2T), and the heterozygous of rs2546620 (A/G) and homozygous-minor of rs1876071 (C/C) and rs1876072 (G/G) were correlated with reduced expression of beta(2T). Significant correlations of expression levels with different alleles and haplotypes were also indicated by quantitative trait analysis. Recombinant GABA(A) receptors expressed in HEK293 human cells containing beta(2L) underwent a steeper current rundown upon repetitive GABA activation than receptors containing beta(2S). The results thus revealed genotype-dependent expression of the alternatively spliced isoforms of GABA(A) receptor beta2 subunit, giving rise to electrophysiological consequences that could play an important role in the pathogenesis mechanism of schizophrenia.
Collapse
Affiliation(s)
- C Zhao
- Bioengineering Graduate Program, Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
During the past several years, there has been increasing interest in the role of the blood-brain barrier (BBB) in epilepsy. Advances in neuroradiology have enhanced our ability to image and study the human cerebrovasculature, and further developments in the research of metabolic deficiencies linked to seizure disorders (e.g., GLUT1 deficiency), neuroinflammation, and multiple drug resistance to antiepileptic drugs (AEDs) have amplified the significance of the BBB's relationship to epilepsy. Prior to 1986, BBB research in epilepsy focused on three main areas: ultrastructural studies, brain glucose availability and transport, and clinical uses of AEDs. However, contrast-based imaging techniques and medical procedures such as BBB disruption provided a framework that demonstrated that the BBB could be reversibly disrupted by pathologic or iatrogenic manipulations, with important implications in terms of CNS drug delivery to "multiple drug resistant" brain. This concept of BBB breakdown for therapeutic purposes has also unveiled a previously unrecognized role for BBB failure as a possible etiologic mechanism in epileptogenesis. Finally, a growing body of evidence has shown that inflammatory mechanisms may participate in the pathological changes observed in epileptic brain, with increasing awareness that blood-borne cells or signals may participate in epileptogenesis by virtue of a leaky BBB. In this article we will review the relationships between BBB function and epilepsy. In particular, we will illustrate consensus and divergence between clinical reality and animal studies.
Collapse
Affiliation(s)
- Emily Oby
- Cleveland Clinic Foundation, Department of Neurological Surgery, Cerebrovascular Research, Ohio 44195, USA
| | | |
Collapse
|
48
|
Abstract
PURPOSE OF REVIEW Ten antiepileptic drugs have been licensed since 1990. Their usage will be briefly reviewed focusing on new data and inclusion in guidelines. The hypotheses exploring the underlying basis of pharmacoresistance will be presented. RECENT FINDINGS Lamotrigine, gabapentin, topiramate, and oxcarbazepine are available for use as monotherapy in many countries following comparative studies with older antiepileptic drugs. Zonisamide and pregabalin have recently obtained licences as adjuvant therapy in the US and Europe for partial epilepsy with or without secondary generalization. The UK National Institute for Clinical Excellence guideline has advised, largely based on cost, against the routine use of modern antiepileptic drugs, except when older drugs have failed or are contraindicated. This contrasts with the US guidelines which are less conservative. Surgically resected specimens from patients with refractory epilepsy have led to the development of two hypotheses to explain pharmacoresistant epilepsy. SUMMARY The introduction of 10 new antiepileptic drugs has provided greater choice for patients and doctors, although evidence in support of their superiority over the older drugs is sparse. This has led to conflicting advice in guidelines. Recent developments in the understanding of pharmacoresistance may explain the relatively high incidence of refractory epilepsy.
Collapse
Affiliation(s)
- Nikolas Hitiris
- Epilepsy Unit, Division of Cardiovascular and Medical Sciences, Western Infirmary, Glasgow G11 6NT, UK
| | | |
Collapse
|