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Scheper M, Sørensen FNF, Ruffolo G, Gaeta A, Lissner LJ, Anink JJ, Korshunova I, Jansen FE, Riney K, van Hecke W, Mühlebner A, Khodosevich K, Schubert D, Palma E, Mills JD, Aronica E. Impaired GABAergic regulation and developmental immaturity in interneurons derived from the medial ganglionic eminence in the tuberous sclerosis complex. Acta Neuropathol 2024; 147:80. [PMID: 38714540 PMCID: PMC11076412 DOI: 10.1007/s00401-024-02737-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/10/2024]
Abstract
GABAergic interneurons play a critical role in maintaining neural circuit balance, excitation-inhibition regulation, and cognitive function modulation. In tuberous sclerosis complex (TSC), GABAergic neuron dysfunction contributes to disrupted network activity and associated neurological symptoms, assumingly in a cell type-specific manner. This GABAergic centric study focuses on identifying specific interneuron subpopulations within TSC, emphasizing the unique characteristics of medial ganglionic eminence (MGE)- and caudal ganglionic eminence (CGE)-derived interneurons. Using single-nuclei RNA sequencing in TSC patient material, we identify somatostatin-expressing (SST+) interneurons as a unique and immature subpopulation in TSC. The disrupted maturation of SST+ interneurons may undergo an incomplete switch from excitatory to inhibitory GABAergic signaling during development, resulting in reduced inhibitory properties. Notably, this study reveals markers of immaturity specifically in SST+ interneurons, including an abnormal NKCC1/KCC2 ratio, indicating an imbalance in chloride homeostasis crucial for the postsynaptic consequences of GABAergic signaling as well as the downregulation of GABAA receptor subunits, GABRA1, and upregulation of GABRA2. Further exploration of SST+ interneurons revealed altered localization patterns of SST+ interneurons in TSC brain tissue, concentrated in deeper cortical layers, possibly linked to cortical dyslamination. In the epilepsy context, our research underscores the diverse cell type-specific roles of GABAergic interneurons in shaping seizures, advocating for precise therapeutic considerations. Moreover, this study illuminates the potential contribution of SST+ interneurons to TSC pathophysiology, offering insights for targeted therapeutic interventions.
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Affiliation(s)
- Mirte Scheper
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
| | - Frederik N F Sørensen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
- IRCCS San Raffaele Roma, 00163, Rome, Italy
| | - Alessandro Gaeta
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
| | - Lilian J Lissner
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
| | - Jasper J Anink
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Irina Korshunova
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Floor E Jansen
- Department of Child Neurology, Brain Center University Medical Center, Member of ERN EpiCare, 3584 BA, Utrecht, The Netherlands
| | - Kate Riney
- Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4067, Australia
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, QLD, 4101, Australia
| | - Wim van Hecke
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Angelika Mühlebner
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Konstantin Khodosevich
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Dirk Schubert
- Department of Cognitive Neurosciences, Radboudumc, Donders Institute for Brain Cognition and Behaviour, 6525 HR, Nijmegen, The Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, University of Rome Sapienza, 00185, Rome, Italy
- IRCCS San Raffaele Roma, 00163, Rome, Italy
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks, SL9 0RJ, UK
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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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.
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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
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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: 10] [Impact Index Per Article: 5.0] [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.
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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
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Ceccanti M, Libonati L, Ruffolo G, Cifelli P, Moret F, Frasca V, Palma E, Inghilleri M, Cambieri C. Effects of 3,4-diaminopyridine on myasthenia gravis: Preliminary results of an open-label study. Front Pharmacol 2022; 13:982434. [PMID: 36052140 PMCID: PMC9424766 DOI: 10.3389/fphar.2022.982434] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Background: 3,4-diaminopyridine (3,4-DAP) can lead to clinical and electrophysiological improvement in myasthenic syndrome; it may thus represent a valuable therapeutic option for patients intolerant to pyridostigmine. Objective: to assess 3,4-diaminopyridine (3,4-DAP) effects and tolerability in patients with anti-AChR myasthenia gravis. Method: Effects were monitored electrophysiologically by repetitive nerve stimulation (RNS) and by standardized clinical testing (QMG score) before and after a single dose administration of 3,4-DAP 10 mg per os in 15 patients. Patients were divided according to their Myasthenia Gravis Foundation of America (MGFA) class into mild and severe. Results: No significant side effects were found, apart from transient paresthesia. 3,4-DAP had a significant effect on the QMG score (p = 0.0251), on repetitive nerve stimulation (p = 0.0251), and on the forced vital capacity (p = 0.03), thus indicating that it may reduce the level of disability and the decremental muscle response. When the patients were divided according to the MGFA classification, 3,4-DAP showed a positive effect in the severe group, either for the QMG score (p = 0.031) or for the RNS decrement (p = 0.031). No significant difference was observed in any of the outcome measures within the mild group (p > 0.05). A direct effect of 3,4-DAP on nicotinic ACh receptors (nAChRs) was excluded since human nAChRs reconstituted in an expression system, which were not affected by 3,4-DAP application. Conclusion: Our results suggest that 3,4-DAP may be a useful add-on therapy, especially in most severe patients or when immunosuppressive treatment has not yet reached its full effect or when significant side-effects are associated with anticholinesterase.
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Affiliation(s)
- Marco Ceccanti
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
| | - Laura Libonati
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Institute Pasteur- Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
- IRCCS San Raffaele Pisana, Rome, Italy
| | - Pierangelo Cifelli
- Department of Applied Clinical and Biotechnological Sciences, University of L'Aquila, L'Aquila, Italy
| | - Federica Moret
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
| | - Vittorio Frasca
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Institute Pasteur- Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Maurizio Inghilleri
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
| | - Chiara Cambieri
- Neuromuscular Disorders Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy
- *Correspondence: Chiara Cambieri,
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Unexpected Effect of IL-1β on the Function of GABA A Receptors in Pediatric Focal Cortical Dysplasia. Brain Sci 2022; 12:brainsci12060807. [PMID: 35741692 PMCID: PMC9220988 DOI: 10.3390/brainsci12060807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 02/04/2023] Open
Abstract
Focal cortical dysplasia (FCD) type II is an epileptogenic malformation of the neocortex, as well as a leading cause of drug-resistant focal epilepsy in children and young adults. The synaptic dysfunctions leading to intractable seizures in this disease appear to have a tight relationship with the immaturity of GABAergic neurotransmission. The likely outcome would include hyperpolarizing responses upon activation of GABAARs. In addition, it is well-established that neuroinflammation plays a relevant role in the pathogenesis of FCD type II. Here, we investigated whether IL-1β, a prototypical pro-inflammatory cytokine, can influence GABAergic neurotransmission in FCD brain tissues. To this purpose, we carried out electrophysiological recordings on Xenopus oocytes transplanted with human tissues and performed a transcriptomics analysis. We found that IL-1β decreases the GABA currents amplitude in tissue samples from adult individuals, while it potentiates GABA responses in samples from pediatric cases. Interestingly, these cases of pediatric FCD were characterized by a more depolarized EGABA and an altered transcriptomics profile, that revealed an up-regulation of chloride cotransporter NKCC1 and IL-1β. Altogether, these results suggest that the neuroinflammatory processes and altered chloride homeostasis can contribute together to increase the brain excitability underlying the occurrence of seizures in these children.
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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.
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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.)
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Rousset M, Humez S, Laurent C, Buée L, Blum D, Cens T, Vignes M, Charnet P. Mammalian Brain Ca2+ Channel Activity Transplanted into Xenopus laevis Oocytes. MEMBRANES 2022; 12:membranes12050496. [PMID: 35629822 PMCID: PMC9146698 DOI: 10.3390/membranes12050496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 02/01/2023]
Abstract
Several mutations on neuronal voltage-gated Ca2+ channels (VGCC) have been shown to cause neurological disorders and contribute to the initiation of epileptic seizures, migraines, or cerebellar degeneration. Analysis of the functional consequences of these mutations mainly uses heterologously expressed mutated channels or transgenic mice which mimic these pathologies, since direct electrophysiological approaches on brain samples are not easily feasible. We demonstrate that mammalian voltage-gated Ca2+ channels from membrane preparation can be microtransplanted into Xenopus oocytes and can conserve their activity. This method, originally described to study the alteration of GABA receptors in human brain samples, allows the recording of the activity of membrane receptors and channels with their native post-translational processing, membrane environment, and regulatory subunits. The use of hippocampal, cerebellar, or cardiac membrane preparation displayed different efficacy for transplanted Ca2+ channel activity. This technique, now extended to the recording of Ca2+ channel activity, may therefore be useful in order to analyze the calcium signature of membrane preparations from unfixed human brain samples or normal and transgenic mice.
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Affiliation(s)
- Matthieu Rousset
- IBMM, UMR 5247 CNRS, Université de Montpellier, ENSCM, 1919 Route de Mende, 34293 Montpellier, France; (T.C.); (M.V.)
- Correspondence: (M.R.); (P.C.); Tel.: +33-467-613-666 (M.R. & P.C.)
| | - Sandrine Humez
- Lille Neuroscience & Cognition, Université de Lille, F-59000 Lille, France; (S.H.); (C.L.); (L.B.); (D.B.)
- Inserm UMR_S1172, Jean-Pierre Aubert Research Centre, F-59000 Lille, France
- Lille Neuroscience & Cognition, Alzheimer & Tauopathies, CHU-Lille, F-59000 Lille, France
| | - Cyril Laurent
- Lille Neuroscience & Cognition, Université de Lille, F-59000 Lille, France; (S.H.); (C.L.); (L.B.); (D.B.)
- Inserm UMR_S1172, Jean-Pierre Aubert Research Centre, F-59000 Lille, France
- Lille Neuroscience & Cognition, Alzheimer & Tauopathies, CHU-Lille, F-59000 Lille, France
| | - Luc Buée
- Lille Neuroscience & Cognition, Université de Lille, F-59000 Lille, France; (S.H.); (C.L.); (L.B.); (D.B.)
- Inserm UMR_S1172, Jean-Pierre Aubert Research Centre, F-59000 Lille, France
- Lille Neuroscience & Cognition, Alzheimer & Tauopathies, CHU-Lille, F-59000 Lille, France
| | - David Blum
- Lille Neuroscience & Cognition, Université de Lille, F-59000 Lille, France; (S.H.); (C.L.); (L.B.); (D.B.)
- Inserm UMR_S1172, Jean-Pierre Aubert Research Centre, F-59000 Lille, France
- Lille Neuroscience & Cognition, Alzheimer & Tauopathies, CHU-Lille, F-59000 Lille, France
| | - Thierry Cens
- IBMM, UMR 5247 CNRS, Université de Montpellier, ENSCM, 1919 Route de Mende, 34293 Montpellier, France; (T.C.); (M.V.)
| | - Michel Vignes
- IBMM, UMR 5247 CNRS, Université de Montpellier, ENSCM, 1919 Route de Mende, 34293 Montpellier, France; (T.C.); (M.V.)
| | - Pierre Charnet
- IBMM, UMR 5247 CNRS, Université de Montpellier, ENSCM, 1919 Route de Mende, 34293 Montpellier, France; (T.C.); (M.V.)
- Correspondence: (M.R.); (P.C.); Tel.: +33-467-613-666 (M.R. & P.C.)
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Mikroulis A, Ledri M, Ruffolo G, Palma E, Sperk G, Dalli J, Vezzani A, Kokaia M. Lipid mediator n-3 docosapentaenoic acid-derived protectin D1 enhances synaptic inhibition of hippocampal principal neurons by interaction with a G-protein-coupled receptor. FASEB J 2022; 36:e22203. [PMID: 35188290 PMCID: PMC9306510 DOI: 10.1096/fj.202101815r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 01/16/2023]
Abstract
Epilepsy is a severe neurological disease manifested by spontaneous recurrent seizures due to abnormal hyper‐synchronization of neuronal activity. Epilepsy affects about 1% of the population and up to 40% of patients experience seizures that are resistant to currently available drugs, thus highlighting an urgent need for novel treatments. In this regard, anti‐inflammatory drugs emerged as potential therapeutic candidates. In particular, specific molecules apt to resolve the neuroinflammatory response occurring in acquired epilepsies have been proven to counteract seizures in experimental models, and humans. One candidate investigational molecule has been recently identified as the lipid mediator n‐3 docosapentaenoic acid‐derived protectin D1 (PD1n‐3DPA) which significantly reduced seizures, cell loss, and cognitive deficit in a mouse model of acquired epilepsy. However, the mechanisms that mediate the PD1n‐3DPA effect remain elusive. We here addressed whether PD1n‐3DPA has direct effects on neuronal activity independent of its anti‐inflammatory action. We incubated, therefore, hippocampal slices with PD1n‐3DPA and investigated its effect on excitatory and inhibitory synaptic inputs to the CA1 pyramidal neurons. We demonstrate that inhibitory drive onto the perisomatic region of the pyramidal neurons is increased by PD1n‐3DPA, and this effect is mediated by pertussis toxin‐sensitive G‐protein coupled receptors. Our data indicate that PD1n‐3DPA acts directly on inhibitory transmission, most likely at the presynaptic site of inhibitory synapses as also supported by Xenopus oocytes and immunohistochemical experiments. Thus, in addition to its anti‐inflammatory effects, PD1n‐3DPA anti‐seizure and neuroprotective effects may be mediated by its direct action on neuronal excitability by modulating their synaptic inputs.
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Affiliation(s)
- Apostolos Mikroulis
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Marco Ledri
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy.,IRCCS San Raffaele Pisana, Rome, Italy
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome Sapienza, Rome, Italy
| | - Günther Sperk
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Jesmond Dalli
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, London, UK
| | - Annamaria Vezzani
- Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy
| | - Merab Kokaia
- Epilepsy Center, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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9
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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.
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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.)
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10
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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.
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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
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11
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Zeng SL, Sudlow LC, Berezin MY. Using Xenopus oocytes in neurological disease drug discovery. Expert Opin Drug Discov 2019; 15:39-52. [PMID: 31674217 DOI: 10.1080/17460441.2020.1682993] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Introduction: Neurological diseases present a difficult challenge in drug discovery. Many of the current treatments have limited efficiency or result in a variety of debilitating side effects. The search of new therapies is of a paramount importance, since the number of patients that require a better treatment is growing rapidly. As an in vitro model, Xenopus oocytes provide the drug developer with many distinct advantages, including size, durability, and efficiency in exogenous protein expression. However, there is an increasing need to refine the recent breakthroughs.Areas covered: This review covers the usage and recent advancements of Xenopus oocytes for drug discovery in neurological diseases from expression and functional measurement techniques to current applications in Alzheimer's disease, painful neuropathies, and amyotrophic lateral sclerosis (ALS). The existing limitations of Xenopus oocytes in drug discovery are also discussed.Expert opinion: With the rise of aging population and neurological disorders, Xenopus oocytes, will continue to play an important role in understanding the mechanism of the disease, identification and validation of novel molecular targets, and drug screening, providing high-quality data despite the technical limitations. With further advances in oocytes-related techniques toward an accurate modeling of the disease, the diagnostics and treatment of neuropathologies will be becoming increasing personalized.
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Affiliation(s)
- Steven L Zeng
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Leland C Sudlow
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Mikhail Y Berezin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
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12
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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.
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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
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13
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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
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14
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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.
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15
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Functional aspects of early brain development are preserved in tuberous sclerosis complex (TSC) epileptogenic lesions. Neurobiol Dis 2016; 95:93-101. [DOI: 10.1016/j.nbd.2016.07.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/05/2016] [Accepted: 07/13/2016] [Indexed: 02/04/2023] Open
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16
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Mazzo F, Zwart R, Serratto GM, Gardinier KM, Porter W, Reel J, Maraula G, Sher E. Reconstitution of synaptic Ion channels from rodent and human brain in Xenopus oocytes: a biochemical and electrophysiological characterization. J Neurochem 2016; 138:384-96. [PMID: 27216696 DOI: 10.1111/jnc.13675] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/10/2016] [Accepted: 05/18/2016] [Indexed: 11/29/2022]
Abstract
Disruption in the expression and function of synaptic proteins, and ion channels in particular, is critical in the pathophysiology of human neuropsychiatric and neurodegenerative diseases. However, very little is known regarding the functional and pharmacological properties of native synaptic human ion channels, and their potential changes in pathological conditions. Recently, an electrophysiological technique has been enabled for studying the functional and pharmacological properties of ion channels present in crude membrane preparation obtained from post-mortem frozen brains. We here extend these studies by showing that human synaptic ion channels also can be studied in this way. Synaptosomes purified from different regions of rodent and human brain (control and Alzheimer's) were characterized biochemically for enrichment of synaptic proteins, and expression of ion channel subunits. The same synaptosomes were also reconstituted in Xenopus oocytes, in which the functional and pharmacological properties of the native synaptic ion channels were characterized using the voltage clamp technique. We show that we can detect GABA, (RS)-α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and NMDA receptors, and modulate them pharmacologically with selective agonists, antagonists, and allosteric modulators. Furthermore, changes in ion channel expression and function were detected in synaptic membranes from Alzheimer's brains. Our present results demonstrate the possibility to investigate synaptic ion channels from healthy and pathological brains. This method of synaptosomes preparation and injection into oocytes is a significant improvement over the earlier method. It opens the way to directly testing, on native ion channels, the effects of novel drugs aimed at modulating important classes of synaptic targets. Disruption in the expression and function of synaptic ion channels is critical in the pathophysiology of human neurodegenerative diseases. We here show that synaptosomes purified from rodent and human frozen brain (control and Alzheimer disease) can be studied both biochemically and functionally. This method opens the way to directly testing the effects of novel drugs on native ion channels.
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Affiliation(s)
- Francesca Mazzo
- Lilly Research Centre, Eli Lilly and Company, Erl Wood Manor, Windlesham, Surrey, GU20 6HP, UK
| | - Ruud Zwart
- Lilly Research Centre, Eli Lilly and Company, Erl Wood Manor, Windlesham, Surrey, GU20 6HP, UK
| | - Giulia Maia Serratto
- Lilly Research Centre, Eli Lilly and Company, Erl Wood Manor, Windlesham, Surrey, GU20 6HP, UK
| | - Kevin M Gardinier
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Warren Porter
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Jon Reel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Giovanna Maraula
- Lilly Research Centre, Eli Lilly and Company, Erl Wood Manor, Windlesham, Surrey, GU20 6HP, UK
| | - Emanuele Sher
- Lilly Research Centre, Eli Lilly and Company, Erl Wood Manor, Windlesham, Surrey, GU20 6HP, UK
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17
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Deflorio C, Palma E, Conti L, Roseti C, Manteca A, Giacomelli E, Catalano M, Limatola C, Inghilleri M, Grassi F. Riluzole blocks human muscle acetylcholine receptors. J Physiol 2012; 590:2519-28. [PMID: 22431338 DOI: 10.1113/jphysiol.2012.230201] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Riluzole, the only drug available against amyotrophic lateral sclerosis (ALS), has recently been shown to block muscle ACh receptors (AChRs), raising concerns about possible negative side-effects on neuromuscular transmission in treated patients. In this work we studied riluzole's impact on the function of muscle AChRs in vitro and on neuromuscular transmission in ALS patients, using electrophysiological techniques. Human recombinant AChRs composed of α(1)β(1)δ subunits plus the γ or ε subunit (γ- or ε-AChR) were expressed in HEK cells or Xenopus oocytes. In both preparations, riluzole at 0.5 μm, a clinically relevant concentration, reversibly reduced the amplitude and accelerated the decay of ACh-evoked current if applied before coapplication with ACh. The action on γ-AChRs was more potent and faster than on ε-AChRs. In HEK outside-out patches, riluzole-induced block of macroscopic ACh-evoked current gradually developed during the initial milliseconds of ACh presence. Single channel recordings in HEK cells and in human myotubes from ALS patients showed that riluzole prolongs channel closed time, but has no effect on channel conductance and open duration. Finally, compound muscle action potentials (CMAPs) evoked by nerve stimulation in ALS patients remained unaltered after a 1 week suspension of riluzole treatment. These data indicate that riluzole, while apparently safe with regard to synaptic transmission, may affect the function of AChRs expressed in denervated muscle fibres of ALS patients, with biological consequences that remain to be investigated.
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Affiliation(s)
- Cristina Deflorio
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
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18
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Physiological characterization of human muscle acetylcholine receptors from ALS patients. Proc Natl Acad Sci U S A 2011; 108:20184-8. [PMID: 22128328 DOI: 10.1073/pnas.1117975108] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of motor neurons leading to muscle paralysis. Research in transgenic mice suggests that the muscle actively contributes to the disease onset, but such studies are difficult to pursue in humans and in vitro models would represent a good starting point. In this work we show that tiny amounts of muscle from ALS or from control denervated muscle, obtained by needle biopsy, are amenable to functional characterization by two different technical approaches: "microtransplantation" of muscle membranes into Xenopus oocytes and culture of myogenic satellite cells. Acetylcholine (ACh)-evoked currents and unitary events were characterized in oocytes and multinucleated myotubes. We found that ALS acetylcholine receptors (AChRs) retain their native physiological characteristics, being activated by ACh and nicotine and blocked by α-bungarotoxin (α-BuTX), d-tubocurarine (dTC), and galantamine. The reversal potential of ACh-evoked currents and the unitary channel behavior were also typical of normal muscle AChRs. Interestingly, in oocytes injected with muscle membranes derived from ALS patients, the AChRs showed a significant decrease in ACh affinity, compared with denervated controls. Finally, riluzole, the only drug currently used against ALS, reduced, in a dose-dependent manner, the ACh-evoked currents, indicating that its action remains to be fully characterized. The two methods described here will be important tools for elucidating the role of muscle in ALS pathogenesis and for developing drugs to counter the effects of this disease.
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Molaee-Ardekani B, Benquet P, Bartolomei F, Wendling F. Computational modeling of high-frequency oscillations at the onset of neocortical partial seizures: From ‘altered structure’ to ‘dysfunction’. Neuroimage 2010; 52:1109-22. [PMID: 20034581 DOI: 10.1016/j.neuroimage.2009.12.049] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 12/09/2009] [Accepted: 12/10/2009] [Indexed: 11/29/2022] Open
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20
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Grassi F, Limatola C, Santoni A. Fabrizio Eusebi (1945–2009). J Neuroimmunol 2010; 224:114-5. [DOI: 10.1016/j.jneuroim.2010.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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Park SA, Yin H, Bhattarai JP, Park SJ, Lee JC, Kim CJ, Han SK. Postnatal change of GluR5 kainate receptor expression in the substantia gelatinosa neuron of the trigeminal subnucleus caudalis in mice. Brain Res 2010; 1346:52-61. [PMID: 20513362 DOI: 10.1016/j.brainres.2010.05.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 05/20/2010] [Accepted: 05/23/2010] [Indexed: 10/19/2022]
Abstract
The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been implicated in the processing of nociceptive information from the orofacial region. Kainate receptors (KARs) play an important role in sensory transmission. Five different KAR subunits have been cloned and the expression of the KAR subunits showed developmental changes. In this study, RT-PCR, western blotting, immunohistochemistry and a patch clamp technique were used examine the functional expression of the GluR5 subunit in the SG of the Vc in juvenile, peripubertal and/or adult mice. The levels of mRNA and protein expression of the GluR5 subunit in the SG of the Vc were higher in the juvenile mice than in the peripubertal or adult mice. In addition, the KA and ATPA, a GluR5 KAR agonist, induced membrane depolarization on the SG neurons in both juvenile and adult mice in a concentration-dependent manner. However, the juvenile SG neurons showed a stronger response to KA and ATPA than those of adults. The membrane depolarization by KA was suppressed slightly in the presence of the AMPA receptor antagonist, GYKI 52466. These results show that the GluR5 KAR subunits are expressed functionally on the SG neurons of the Vc in mice, and the expression levels of the GluR5 subunits decrease with postnatal development. These postnatal changes in the GluR5 KAR subunit may be a possible mechanism for age-dependent pain processing.
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Affiliation(s)
- Seon Ah Park
- Department of Oral Physiology and BK21 program, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, 561-756, Republic of Korea
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Fritsch B, Qashu F, Figueiredo TH, Aroniadou-Anderjaska V, Rogawski MA, Braga MF. Pathological alterations in GABAergic interneurons and reduced tonic inhibition in the basolateral amygdala during epileptogenesis. Neuroscience 2009; 163:415-29. [PMID: 19540312 PMCID: PMC2733834 DOI: 10.1016/j.neuroscience.2009.06.034] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/11/2009] [Accepted: 06/15/2009] [Indexed: 11/18/2022]
Abstract
An acute brain insult such as traumatic head/brain injury, stroke, or an episode of status epilepticus can trigger epileptogenesis, which, after a latent, seizure-free period, leads to epilepsy. The discovery of effective pharmacological interventions that can prevent the development of epilepsy requires knowledge of the alterations that occur during epileptogenesis in brain regions that play a central role in the induction and expression of epilepsy. In the present study, we investigated pathological alterations in GABAergic interneurons in the rat basolateral amygdala (BLA), and the functional impact of these alterations on inhibitory synaptic transmission, on days 7 to 10 after status epilepticus induced by kainic acid. Using design-based stereology combined with glutamic acid decarboxylase (GAD) 67 immunohistochemistry, we found a more extensive loss of GABAergic interneurons compared to the loss of principal cells. Fluoro-Jade C staining showed that neuronal degeneration was still ongoing. These alterations were accompanied by an increase in the levels of GAD and the alpha1 subunit of the GABA(A) receptor, and a reduction in the GluK1 (previously known as GluR5) subunit, as determined by Western blots. Whole-cell recordings from BLA pyramidal neurons showed a significant reduction in the frequency and amplitude of action potential-dependent spontaneous inhibitory postsynaptic currents (IPSCs), a reduced frequency but not amplitude of miniature IPSCs, and impairment in the modulation of IPSCs via GluK1-containing kainate receptors (GluK1Rs). Thus, in the BLA, GABAergic interneurons are more vulnerable to seizure-induced damage than principal cells. Surviving interneurons increase their expression of GAD and the alpha1 GABA(A) receptor subunit, but this does not compensate for the interneuronal loss; the result is a dramatic reduction of tonic inhibition in the BLA circuitry. As activation of GluK1Rs by ambient levels of glutamate facilitates GABA release, the reduced level and function of these receptors may contribute to the reduction of tonic inhibitory activity. These alterations at a relatively early stage of epileptogenesis may facilitate the progress towards the development of epilepsy.
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Affiliation(s)
- Brita Fritsch
- Epilepsy Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Felicia Qashu
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Taiza H. Figueiredo
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Vassiliki Aroniadou-Anderjaska
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Michael A. Rogawski
- Epilepsy Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Maria F.M. Braga
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
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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]
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Activation of kainate GLU(K5) transmission rescues kindling-induced impairment of LTP in the rat lateral amygdala. Neuropsychopharmacology 2008; 33:2524-35. [PMID: 18046310 DOI: 10.1038/sj.npp.1301633] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The amygdala is a component of the limbic system that plays a central role in emotional behavior and certain psychiatric diseases. Pathophysiological alterations of neuronal excitability in the amygdala are characteristic features of temporal lobe epilepsy and certain (epilepsy accompanying) psychiatric illnesses such as anxiety and depressive disorders. The role of kainate receptors in the activity of synaptic networks, in brain function, and diseases is still poorly understood. Various kainate receptor subtypes have been shown to contribute to synaptic transmission and modulate presynaptic release of glutamate and gamma-aminobutyric acid (GABA). Several lines of evidence point to the importance of GLU(K5) kainate receptors in epilepsy. In this study we investigated the role of specific GLU(K5) kainate receptor in the lateral nucleus of the amygdala (LA). The cellular mechanisms for emotional learning in the amygdala are believed to be the result of changes in synaptic transmission efficacy, similar to long-term potentiation (LTP). Here, we used both field potential and intracellular recordings in horizontal rat amygdala slices, and showed that LTP in the LA, induced by high-frequency stimulation of afferents running within LA, is impaired 48 h after the last induced seizure. This kindling-induced impairment was reversed by the specific kainate GLU(K5) agonist ATPA. Partial blockade of GABAergic transmission with the specific GABA(A) receptor antagonist SR95531 also significantly facilitated the induction of early LA-LTP, but only partially abolished the kindling-induced impairment of LA-LTP. This study shows that the stimulation of the GLU(K5) kainate receptor subtype rescues the kindling-induced impairment of LA-LTP at least within 48 h after the last seizure. Therefore, GLU(K5) kainate receptor subunits are involved in kindling-induced plasticity changes in the amygdala.
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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.
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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.
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Sandoval M, Sandoval R, Thomas U, Spilker C, Smalla KH, Falcon R, Marengo JJ, Calderón R, Saavedra V, Heumann R, Bronfman F, Garner CC, Gundelfinger ED, Wyneken U. Antagonistic effects of TrkB and p75NTRon NMDA receptor currents in post-synaptic densities transplanted into Xenopus oocytes. J Neurochem 2007; 101:1672-84. [PMID: 17394529 DOI: 10.1111/j.1471-4159.2007.04519.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are essential regulators of synaptic function in the adult CNS. A TrkB-mediated effect at excitatory synapses is enhancement of NMDA receptor (NMDA-R)-mediated currents. Recently, opposing effects of TrkB and the pan-neurotrophin receptor p75(NTR) on long-term synaptic depression and long-term potentiation have been reported in the hippocampus. To further study the regulation of NMDA-Rs by neurotrophin receptors in their native protein environment, we micro-transplanted rat forebrain post-synaptic densities (PSDs) into Xenopus oocytes. One-minute incubations of oocytes with BDNF led to dual effects on NMDA-R currents: either TrkB-dependent potentiation or TrkB-independent inhibition were observed. Pro-nerve growth factor, a ligand for p75(NTR) but not for TrkB, produced a reversible, dose-dependent, TrkB-independent and p75(NTR)-dependent inhibition of NMDA-Rs. Fractionation experiments showed that p75(NTR) is highly enriched in the PSD protein fraction. Immunoprecipitation and pull-down experiments further revealed that p75(NTR) is a core component of the PSD, where it interacts with the PDZ3 domain of the scaffolding protein SAP90/PSD-95. Our data provide striking evidence for a rapid inhibitory effect of p75(NTR) on NMDA-R currents that antagonizes TrkB-mediated NMDA-R potentiation. These opposing mechanisms might be present in a large proportion of forebrain synapses and may contribute importantly to synaptic plasticity.
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Affiliation(s)
- Mauricio Sandoval
- Laboratorio de Neurociencias, Universidad de Los Andes, Santiago, Chile
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Aroniadou-Anderjaska V, Qashu F, Braga MFM. Mechanisms regulating GABAergic inhibitory transmission in the basolateral amygdala: implications for epilepsy and anxiety disorders. Amino Acids 2006; 32:305-15. [PMID: 17048126 DOI: 10.1007/s00726-006-0415-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 08/09/2006] [Indexed: 11/26/2022]
Abstract
The amygdala, a temporal lobe structure that is part of the limbic system, has long been recognized for its central role in emotions and emotional behavior. Pathophysiological alterations in neuronal excitability in the amygdala are characteristic features of certain psychiatric illnesses, such as anxiety disorders and depressive disorders. Furthermore, neuronal excitability in the amygdala, and, in particular, excitability of the basolateral nucleus of the amygdala (BLA) plays a pivotal role in the pathogenesis and symptomatology of temporal lobe epilepsy. Here, we describe two recently discovered mechanisms regulating neuronal excitability in the BLA, by modulating GABAergic inhibitory transmission. One of these mechanisms involves the regulation of GABA release via kainate receptors containing the GluR5 subunit (GluR5KRs). In the rat BLA, GluR5KRs are present on both somatodendritic regions and presynaptic terminals of GABAergic interneurons, and regulate GABA release in an agonist concentration-dependent, bidirectional manner. The relevance of the GluR5KR function to epilepsy is suggested by the findings that GluR5KR agonists can induce epileptic activity, whereas GluR5KR antagonists can prevent it. Further support for an important role of GluR5KRs in epilepsy comes from the findings that antagonism of GluR5KRs is a primary mechanism underlying the antiepileptic properties of the anticonvulsant topiramate. Another mechanism regulating neuronal excitability in the BLA by modulating GABAergic synaptic transmission is the facilitation of GABA release via presynaptic alpha1A adrenergic receptors. This mechanism may significantly underlie the antiepileptic properties of norepinephrine. Notably, the alpha1A adrenoceptor-mediated facilitation of GABA release is severely impaired by stress. This stress-induced impairment in the noradrenergic facilitation of GABA release in the BLA may underlie the hyperexcitability of the amygdala in certain stress-related affective disorders, and may explain the stress-induced exacerbation of seizure activity in epileptic patients.
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Affiliation(s)
- V Aroniadou-Anderjaska
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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29
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Köhling R, Avoli M. Methodological approaches to exploring epileptic disorders in the human brain in vitro. J Neurosci Methods 2006; 155:1-19. [PMID: 16753220 DOI: 10.1016/j.jneumeth.2006.04.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/03/2006] [Accepted: 04/18/2006] [Indexed: 10/24/2022]
Abstract
Brain surgery, and in particular epilepsy surgery, offers the unique opportunity to study viable human central nervous tissue in vitro. This does not only open a window to address the basic mechanisms underlying human disease, such as epilepsy, but it allows to venture into investigating neurophysiological functions per se. In the present paper, we describe the most commonly used methods in the electrophysiological (and, at least to some extent, also histochemical and molecular) analysis of human tissue in vitro. In addition, we consider the pitfalls and limitations of such studies, in particular regarding the issue of tissue sampling procedures and control experiments.
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Affiliation(s)
- Rüdiger Köhling
- Institute of Physiology, University of Rostock, 18055 Rostock, Germany
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Miledi R, Palma E, Eusebi F. Microtransplantation of neurotransmitter receptors from cells to Xenopus oocyte membranes: new procedure for ion channel studies. Methods Mol Biol 2006; 322:347-55. [PMID: 16739735 DOI: 10.1007/978-1-59745-000-3_24] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The Xenopus oocyte is largely used as a cell expression system for studying both structure and function of transmitter receptors and ion channels. Messenger RNA extracted from the brain and injected into oocytes leads to the synthesis and membrane incorporation of many types of functional ion channels. A new method was developed further to transplant neurotransmitter receptors from human brain or cultured cell lines to the membrane of Xenopus oocytes. This method represents a modification of the method used many years ago of injecting into oocytes membrane vesicles from Torpedo electroplaques, yielding the expression of functional Torpedo acetylcholine receptors. We describe this approach by extracting membrane vesicles from human hippocampus or temporal neocortex and from mammalian cell lines stably expressing glutamate or neuronal nicotinic receptors. Because the human neurotransmitter receptors are "microtransplanted" with their native cell membranes, this method extends the usefulness of Xenopus oocytes as an expression system for addressing issues in many fields, including channelopathies.
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Affiliation(s)
- Ricardo Miledi
- Instituto de Neurobiología, Campus UNAM-Juriquilla, México
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31
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Palma E, Spinelli G, Torchia G, Martinez-Torres A, Ragozzino D, Miledi R, Eusebi F. Abnormal GABAA receptors from the human epileptic hippocampal subiculum microtransplanted to Xenopus oocytes. Proc Natl Acad Sci U S A 2005; 102:2514-8. [PMID: 15695331 PMCID: PMC549013 DOI: 10.1073/pnas.0409687102] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We studied the properties of GABAA receptors microtransplanted from the human temporal lobe epilepsy (TLE)-associated brain regions to Xenopus oocytes. Cell membranes, isolated from surgically resected brain specimens of drug-resistant TLE patients, were injected into frog oocytes, which rapidly incorporated human GABAA receptors, and any associated proteins, into their surface membrane. The receptors originating from different epileptic brain regions had a similar run-down but an affinity for GABA that was approximately 60% lower for the subiculum receptors than for receptors issuing from the hippocampus proper or the temporal lobe neocortex. Moreover, GABA currents recorded in oocytes injected with membranes from the subiculum had a more depolarized reversal potential compared with the hippocampus proper or neocortex of the same patients. Quantitative RT-PCR analysis was performed of the GABAA receptor alpha1- to alpha5-, beta1- to beta3-, gamma2- to gamma3-, and delta-subunit mRNAs. The levels of expression of the alpha3-, alpha5-, and beta1- to beta3- subunit mRNAs are significantly higher, with the exception of gamma2-subunit whose expression is lower, in subiculum compared with neocortex specimens. Our results suggest that an abnormal GABA-receptor subunit transcription in the TLE subiculum leads to the expression of GABAA receptors with a relatively low affinity. This abnormal behavior of the subiculum GABAA receptors may contribute to epileptogenesis.
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Affiliation(s)
- Eleonora Palma
- Istituto Pasteur Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma La Sapienza, Piazzale Aldo Moro 5, I00185 Rome, Italy. eleonora@
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32
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Morimoto K, Fahnestock M, Racine RJ. Kindling and status epilepticus models of epilepsy: rewiring the brain. Prog Neurobiol 2004; 73:1-60. [PMID: 15193778 DOI: 10.1016/j.pneurobio.2004.03.009] [Citation(s) in RCA: 613] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 03/24/2004] [Indexed: 01/09/2023]
Abstract
This review focuses on the remodeling of brain circuitry associated with epilepsy, particularly in excitatory glutamate and inhibitory GABA systems, including alterations in synaptic efficacy, growth of new connections, and loss of existing connections. From recent studies on the kindling and status epilepticus models, which have been used most extensively to investigate temporal lobe epilepsy, it is now clear that the brain reorganizes itself in response to excess neural activation, such as seizure activity. The contributing factors to this reorganization include activation of glutamate receptors, second messengers, immediate early genes, transcription factors, neurotrophic factors, axon guidance molecules, protein synthesis, neurogenesis, and synaptogenesis. Some of the resulting changes may, in turn, contribute to the permanent alterations in seizure susceptibility. There is increasing evidence that neurogenesis and synaptogenesis can appear not only in the mossy fiber pathway in the hippocampus but also in other limbic structures. Neuronal loss, induced by prolonged seizure activity, may also contribute to circuit restructuring, particularly in the status epilepticus model. However, it is unlikely that any one structure, plastic system, neurotrophin, or downstream effector pathway is uniquely critical for epileptogenesis. The sensitivity of neural systems to the modulation of inhibition makes a disinhibition hypothesis compelling for both the triggering stage of the epileptic response and the long-term changes that promote the epileptic state. Loss of selective types of interneurons, alteration of GABA receptor configuration, and/or decrease in dendritic inhibition could contribute to the development of spontaneous seizures.
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Affiliation(s)
- Kiyoshi Morimoto
- Department of Neuropsychiatry, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
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33
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Palma E, Ragozzino DA, Di Angelantonio S, Spinelli G, Trettel F, Martinez-Torres A, Torchia G, Arcella A, Di Gennaro G, Quarato PP, Esposito V, Cantore G, Miledi R, Eusebi F. Phosphatase inhibitors remove the run-down of gamma-aminobutyric acid type A receptors in the human epileptic brain. Proc Natl Acad Sci U S A 2004; 101:10183-8. [PMID: 15218107 PMCID: PMC454185 DOI: 10.1073/pnas.0403683101] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The properties of gamma-aminobutyric acid (GABA) type A receptors (GABA(A) receptors) microtransplanted from the human epileptic brain to the plasma membrane of Xenopus oocytes were compared with those recorded directly from neurons, or glial cells, in human brains slices. Cell membranes isolated from brain specimens, surgically obtained from six patients afflicted with drug-resistant temporal lobe epilepsy (TLE) were injected into frog oocytes. Within a few hours, these oocytes acquired GABA(A) receptors that generated GABA currents with an unusual run-down, which was inhibited by orthovanadate and okadaic acid. In contrast, receptors derived from membranes of a nonepileptic hippocampal uncus, membranes from mouse brain, or recombinant rat alpha 1 beta 2 gamma 2-GABA receptors exhibited a much less pronounced GABA-current run-down. Moreover, the GABA(A) receptors of pyramidal neurons in temporal neocortex slices from the same six epileptic patients exhibited a stronger run-down than the receptors of rat pyramidal neurons. Interestingly, the GABA(A) receptors of neighboring glial cells remained substantially stable after repetitive activation. Therefore, the excessive GABA-current run-down observed in the membrane-injected oocytes recapitulates essentially what occurs in neurons, rather than in glial cells. Quantitative RT-PCR analyses from the same TLE neocortex specimens revealed that GABA(A)-receptor beta 1, beta 2, beta 3, and gamma 2 subunit mRNAs were significantly overexpressed (8- to 33-fold) compared with control autopsy tissues. Our results suggest that an abnormal GABA-receptor subunit transcription in the TLE brain leads to the expression of run-down-enhanced GABA(A) receptors. Blockage of phosphatases stabilizes the TLE GABA(A) receptors and strengthens GABAergic inhibition. It may be that this process can be targeted to develop new treatments for intractable epilepsy.
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Affiliation(s)
- E Palma
- 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, I00185 Rome, Italy
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Di Gennaro G, Quarato PP, Sebastiano F, Esposito V, Onorati P, Mascia A, Romanelli P, Grammaldo LG, Falco C, Scoppetta C, Eusebi F, Manfredi M, Cantore G. Postoperative EEG and seizure outcome in temporal lobe epilepsy surgery. Clin Neurophysiol 2004; 115:1212-9. [PMID: 15066547 DOI: 10.1016/j.clinph.2003.12.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2003] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To assess the prognostic value of scalp electroencephalogram (EEG) after epilepsy surgery, we investigated whether postoperative EEG abnormalities (interictal epileptiform discharges, IED; interictal slow activity, ISA) were associated with seizure outcome and other patient characteristics after resective surgery in patients with temporal lobe epilepsy (TLE). METHODS Sixty-two patients with medically refractory TLE who underwent surgery were studied. Patients were categorized according to etiology (mesiotemporal sclerosis vs. tumors/cortical dysplasias); extent of surgical resection (extensive vs. limited); and amount of preoperative IED on wake EEG (oligospikers, <1 IED/h, vs. spikers). Patients were also classified as seizure-free (SF) or having persistent seizures/auras (not-SF) during follow up visits 1 month and 1 year after surgery. Preoperative 60-min interictal EEGs were evaluated for IED and ISA, and compared to postoperative wake EEGs. RESULTS Seizures/auras persisted in 16/62 (25.8%) patients at 1 month and in 8/62 (12.9%) at 1 year follow up. ISA was not significantly related to outcome. Of 42 patients with EEG negative for IED at 1 month, 4 were not-SF; at 1 year, one of 44 such patients was not-SF. IED was significantly associated with seizure/aura persistence in patients categorized as mesiotemporal sclerosis and with extensive surgery. Oligospikers and spikers on preoperative EEG showed no differences in the postoperative seizure outcome, excellent in both cases; moreover, the presence of postoperative IEDs indicated auras/seizures persistence apart from the preoperative EEG spike frequency. CONCLUSIONS Our study showed that the presence of IED of postoperatve EEG strongly indicates seizure/aura persistence. Therefore, serial EEGs should be included in postoperative follow up schedules as a crucial tool in evaluating seizure outcome.
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Affiliation(s)
- Giancarlo Di Gennaro
- Epilepsy Surgery Unit, Department of Neurosciences, IRCCS NEUROMED, via Atinense, 18, 86077 Pozzilli (IS), Italy.
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35
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Miledi R, Dueñas Z, Martinez-Torres A, Kawas CH, Eusebi F. Microtransplantation of functional receptors and channels from the Alzheimer's brain to frog oocytes. Proc Natl Acad Sci U S A 2004; 101:1760-3. [PMID: 14749517 PMCID: PMC341849 DOI: 10.1073/pnas.0308224100] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
About a decade ago, cell membranes from the electric organ of Torpedo and from the rat brain were transplanted to frog oocytes, which thus acquired functional Torpedo and rat neurotransmitter receptors. Nevertheless, the great potential that this method has for studying human diseases has remained virtually untapped. Here, we show that cell membranes from the postmortem brains of humans that suffered Alzheimer's disease can be microtransplanted to the plasma membrane of Xenopus oocytes. We show also that these postmortem membranes carry neurotransmitter receptors and voltage-operated channels that are still functional, even after they have been kept frozen for many years. This method provides a new and powerful approach to study directly the functional characteristics and structure of receptors, channels, and other membrane proteins of the Alzheimer's brain. This knowledge may help in understanding the basis of Alzheimer's disease and also help in developing new treatments.
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Affiliation(s)
- R Miledi
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4550, USA.
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36
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Palma E, Trettel F, Fucile S, Renzi M, Miledi R, Eusebi F. Microtransplantation of membranes from cultured cells to Xenopus oocytes: a method to study neurotransmitter receptors embedded in native lipids. Proc Natl Acad Sci U S A 2003; 100:2896-900. [PMID: 12595576 PMCID: PMC151437 DOI: 10.1073/pnas.0438006100] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Xenopus oocyte is used as a convenient cell expression system to study the structure and function of heterogenic transmitter receptors and ion channels. Recently, we introduced a method to microtransplant already assembled neurotransmitter receptors from the human brain to the plasma membrane of Xenopus oocytes. The same approach was used here to transplant neurotransmitter receptors expressed from cultured cells to the oocytes. Membrane vesicles prepared from a human embryonic kidney cell line (HEK293) stably expressing the rat glutamate receptor 1 were injected into oocytes, and, within a few hours, the oocyte plasma membrane acquired alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors, which had the same properties as those expressed in the original HEK cells. Analogously, oocytes injected with membranes prepared from rat pituitary GH(4)C1 cells, stably expressing homomeric human neuronal alpha 7 nicotinic acetylcholine receptors (alpha 7-AcChoRs), incorporated in their plasma membrane AcChoRs that behaved as those expressed in GH(4)C1 cells. Similar results were obtained with HEK cells stably expressing heteromeric human neuronal alpha 4 beta 2-AcChoRs. All this makes the Xenopus oocyte a powerful tool for detailed investigations of receptors and other proteins expressed in the membrane of cultured cells.
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Affiliation(s)
- Eleonora Palma
- Istituto Pasteur-Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Universita' di Roma La Sapienza, Piazzale Aldo Moro 5, I-00185 Rome, Italy
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