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Wang D, Lu D, Zhang M, Dai A, Jin G, Wang Q, Zhang Y, Kahane P. Advances in epileptic network findings of hypothalamic hamartomas. J Cent Nerv Syst Dis 2024; 16:11795735241237627. [PMID: 38449707 PMCID: PMC10916467 DOI: 10.1177/11795735241237627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 01/16/2024] [Indexed: 03/08/2024] Open
Abstract
Hypothalamic hamartomas (HHs) are congenital developmental malformations located in the hypothalamus. They are associated with a characteristic clinical manifestation known as gelastic seizures (GS). However, the traditional understanding of HHs has been limited, resulting in insufficient treatment options and high recurrence rates of seizures after surgery. This is consistent with the network hypothesis of focal epilepsy that the epileptogenic zone is not only limited to HH but may also involve the distant cerebral cortex external to the HH mass. The epilepsy network theory, on the other hand, provides a new perspective. In this study, we aim to explore HH-related epilepsy as a network disease, challenging the conventional notion of being a focal lesional disease. We analyze various aspects of HHs, including genes and signaling pathways, local circuits, the whole-brain level, phenotypical expression in terms of seizure semiology, and comorbidities. By examining HHs through the lens of network theory, we can enhance our understanding of the condition and potentially identify novel approaches for more effective management and treatment of epilepsy associated with HHs.
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Affiliation(s)
- Di Wang
- School of Engineering Medicine, Beihang University, Beijing, China
| | - Di Lu
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China
| | - Mingtai Zhang
- School of Engineering Medicine, Beihang University, Beijing, China
| | - Anqi Dai
- School of Engineering Medicine, Beihang University, Beijing, China
| | - Guangyuan Jin
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Qiao Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuyang Zhang
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Philippe Kahane
- Neurology Deparment, CHU Grenoble Alpes, University Grenoble Alpes, Grenoble Institute Neuroscience, Grenoble, France
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2
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Physiological Role of ATPase for GABA A Receptor Resensitization. Int J Mol Sci 2022; 23:ijms23105320. [PMID: 35628132 PMCID: PMC9141714 DOI: 10.3390/ijms23105320] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 02/01/2023] Open
Abstract
γ-Aminobutyric acid type A receptors (GABAARs) mediate primarily inhibitory synaptic transmission in the central nervous system. Following fast-paced activation, which provides the selective flow of mainly chloride (Cl−) and less bicarbonate (HCO3−) ions via the pore, these receptors undergo desensitization that is paradoxically prevented by the process of their recovery, referred to as resensitization. To clarify the mechanism of resensitization, we used the cortical synaptoneurosomes from the rat brain and HEK 293FT cells. Here, we describe the effect of γ-phosphate analogues (γPAs) that mimic various states of ATP hydrolysis on GABAAR-mediated Cl− and HCO3− fluxes in response to the first and repeated application of the agonist. We found that depending on the presence of bicarbonate, opened and desensitized states of the wild or chimeric GABAARs had different sensitivities to γPAs. This study presents the evidence that recovery of neuronal Cl− and HCO3− concentrations after desensitization is accompanied by a change in the intracellular ATP concentration via ATPase performance. The transition between the desensitization and resensitization states was linked to changes in both conformation and phosphorylation. In addition, the chimeric β3 isoform did not exhibit the desensitization of the GABAAR-mediated Cl− influx but only the resensitization. These observations lend a new physiological significance to the β3 subunit in the manifestation of GABAAR resensitization.
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Affiliation(s)
- Sergey A. Menzikov
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Correspondence: ; Tel.: +7-(499)-151-1756; Fax: +7-(495)-601-2366
| | - Danila M. Zaichenko
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
| | - Aleksey A. Moskovtsev
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Russian Medical Academy of Postdoctoral Education, Federal State Budgetary Educational Institution of Further Professional Education of the Ministry of Healthcare of the Russian Federation, 2/1, Barrykadnaya St., 125993 Moscow, Russia
| | - Sergey G. Morozov
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
| | - Aslan A. Kubatiev
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Russian Medical Academy of Postdoctoral Education, Federal State Budgetary Educational Institution of Further Professional Education of the Ministry of Healthcare of the Russian Federation, 2/1, Barrykadnaya St., 125993 Moscow, Russia
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3
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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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4
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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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5
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Intricacies of GABA A Receptor Function: The Critical Role of the β3 Subunit in Norm and Pathology. Int J Mol Sci 2021; 22:ijms22031457. [PMID: 33535681 PMCID: PMC7867123 DOI: 10.3390/ijms22031457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Neuronal intracellular chloride ([Cl−]i) is a key determinant in γ-aminobutyric acid type A (GABA)ergic signaling. γ-Aminobutyric acid type A receptors (GABAARs) mediate both inhibitory and excitatory neurotransmission, as the passive fluxes of Cl− and HCO3− via pores can be reversed by changes in the transmembrane concentration gradient of Cl−. The cation–chloride co-transporters (CCCs) are the primary systems for maintaining [Cl−]i homeostasis. However, despite extensive electrophysiological data obtained in vitro that are supported by a wide range of molecular biological studies on the expression patterns and properties of CCCs, the presence of ontogenetic changes in [Cl−]i—along with the consequent shift in GABA reversal potential—remain a subject of debate. Recent studies showed that the β3 subunit possesses properties of the P-type ATPase that participates in the ATP-consuming movement of Cl− via the receptor. Moreover, row studies have demonstrated that the β3 subunit is a key player in GABAAR performance and in the appearance of serious neurological disorders. In this review, we discuss the properties and driving forces of CCCs and Cl−, HCO3−ATPase in the maintenance of [Cl−]i homeostasis after changes in upcoming GABAAR function. Moreover, we discuss the contribution of the β3 subunit in the manifestation of epilepsy, autism, and other syndromes.
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6
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Scholly J, Bartolomei F. Gelastic seizures and the hypothalamic hamartoma syndrome: Epileptogenesis beyond the lesion? HANDBOOK OF CLINICAL NEUROLOGY 2021; 182:143-154. [PMID: 34266589 DOI: 10.1016/b978-0-12-819973-2.00010-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The clinicoradiologic syndrome of hypothalamic hamartoma (HH) manifests with a variety of symptoms, including pharmacoresistant epilepsy with multiple seizure types, precocious puberty, behavioral disturbances, and cognitive impairment. Gelastic seizures are an early marker of epilepsy with HH in most of the cases. Despite a high variability, two major epilepsy phenotypes can be distinguished, based on electroclinical features: (i) focal seizures with epigastric or déjà-vu aura, loss of consciousness, and oroalimentary or gestural automatisms suggestive of temporal lobe involvement; and (ii) motor seizures with tonic, atonic, myoclonic, or versive phenomena, suggesting frontoparietal network involvement, with possible evolution toward an epileptic encephalopathy. The underlying physiopathologic mechanisms are not completely elucidated. The well-known intrinsic epileptogenicity of the HH represents the rationale for direct HH-aiming surgical procedures, with variable success in achieving seizure freedom. The concept of kindling-like secondary epileptogenesis has been suggested as a possible putative mechanism since the very beginnings of the hamartocentric era. Accordingly, a cortical area with enhanced epileptogenic properties due to an independent stage of secondary epileptogenesis would be responsible for seizures persisting after hamartoma ablation. However, recent intracerebral stereotactic EEG (SEEG) explorations demonstrated more complex, both reciprocal and hierarchical, relationships within the hypothalamo-cortical epileptogenic networks. Network formation may be due to either secondary epileptogenesis or widespread epileptogenicity present at the outset. A short time window from epilepsy onset to surgery seems to be crucial to cure epilepsy by direct surgery addressing a hamartoma. SEEG exploration may be reasonably proposed in cases where clinical data suggest an extension of the epileptogenic zone outside the limits of the HH, especially in focal seizures with impaired awareness and absence of gelastic seizures, or after a failure of the direct HH-aiming procedure.
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Affiliation(s)
- Julia Scholly
- Department of Epileptology and Cerebral Rhythmology, Aix Marseille University, Hôpital Timone, Marseille, France; Center for Magnetic Resonance in Biology and Medicine, Aix Marseille University, Hôpital Timone, Marseille, France
| | - Fabrice Bartolomei
- Department of Epileptology and Cerebral Rhythmology, Aix Marseille University, Hôpital Timone, Marseille, France; Institut de Neurosciences des Systèmes, Aix Marseille University, Marseille, France.
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7
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Ectopic GABA A receptor β3 subunit determines Cl - / HCO 3 - -ATPase and chloride transport in HEK 293FT cells. FEBS J 2020; 288:699-712. [PMID: 32383536 DOI: 10.1111/febs.15359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/09/2020] [Accepted: 05/04/2020] [Indexed: 01/20/2023]
Abstract
Neuronal intracellular chloride concentration ([Cl- ]i ) is a crucial determinant of transmission mediated by the γ-aminobutyric acid type A receptor (GABAA R), which subserves synaptic and extrasynaptic inhibition as well as excitation. The Cl- ion is the main carrier of charge through the GABAA R; however, bicarbonate ions ( HCO 3 - ) flowing in the opposite direction can also contribute to the net current. The direction of Cl- and HCO 3 - fluxes is determined by the underlying electrochemical gradient, which is controlled by Cl- transporters and channels. Accumulating evidence suggests that active mechanisms of chloride transport across the GABAA R pore can underlie the regulation of [Cl- ]i . Measurement of Cl- / HCO 3 - -ATPase activity and Cl- transport in HEK 293FT cells expressing homomeric or heteromeric GABAA R ensembles (α2, β3, or γ2) with fluorescent dye for chloride demonstrated that receptor subtypes containing the β3 subunit show enzymatic activity and participate in GABA-mediated or ATP-dependent Cl- transport. GABA-mediated flow of Cl- ions into and out of the cells occurred for a short time period but then rapidly declined. However, Cl- ion flux was stabilized for a long time period in the presence of HCO 3 - ions. The reconstituted β3 subunit isoform, purified as a fusion protein, confirmed that β3 is critical for ATPase; however, only the triplet variant showed the full receptor function. The high sensitivity of the enzyme to γ-phosphate inhibitors led us to postulate that the β3 subunit is catalytic. Our discovery of a GABAA R type that requires ATP consumption for chloride movement provides new insight into the molecular mechanisms of inhibitory signaling.
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Affiliation(s)
| | | | - Aleksey A Moskovtsev
- Institute of General Pathology and Pathophysiology, Moscow, Russia.,Russian Medical Academy of Postdoctoral Education, Moscow, Russia
| | - Sergey G Morozov
- Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aslan A Kubatiev
- Institute of General Pathology and Pathophysiology, Moscow, Russia.,Russian Medical Academy of Postdoctoral Education, Moscow, Russia
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Roseti C, Cifelli P, Ruffolo G, Barbieri E, Guescini M, Esposito V, Di Gennaro G, Limatola C, Giovannelli A, Aronica E, Palma E. Erythropoietin Increases GABA A Currents in Human Cortex from TLE Patients. Neuroscience 2019; 439:153-162. [PMID: 31047977 DOI: 10.1016/j.neuroscience.2019.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 11/15/2022]
Abstract
Erythropoietin (EPO) is a hematopoietic growth factor that has an important role in the erythropoiesis. EPO and its receptor (EPO-R) are expressed all over in the mammalian brain. Furthermore, it has been reported that EPO may exert neuroprotective effect in animal models of brain disorders as ischemia and epilepsy. Here, we investigate whether EPO could modulate the GABA-evoked currents (IGABA) in both human epileptic and non-epileptic control brain tissues. Therefore, we transplanted in Xenopus oocytes cell membranes obtained from autoptic and surgical brain tissues (cortex) of seven temporal lope epilepsy (TLE) patients and of five control patients. Two microelectrodes voltage-clamp technique has been used to record IGABA. Moreover, qRT-PCR assay was performed in the same human tissues to quantify the relative gene expression levels of EPO/EPO-R. To further confirm experiments in oocytes, we performed additional experiments using patch-clamp recording in slices obtained from rat cerebellum. We show that exposure to EPO significantly increased the amplitude of the IGABA in all the patients analyzed. No differences in the expression of EPO and EPO-R in both TLE and control patients have been found. Notably, the increase of IGABA has been recorded also in rat cerebellar slices. Our findings show a new modulatory action of EPO on GABAA receptors (GABAA-Rs). This effect could be relevant to balance the GABAergic dysfunction in human TLE. This article is part of a Special Issue entitled: Honoring Ricardo Miledi - outstanding neuroscientist of XX-XXI centuries.
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Affiliation(s)
| | - Pierangelo Cifelli
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy; IRCCS San Raffaele Pisana, Rome, Italy
| | - Elena Barbieri
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | - Michele Guescini
- Department of Biomolecular Science, University of Urbino Carlo Bo, Urbino, Italy
| | | | | | - Cristina Limatola
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy; IRCCS Neuromed, Pozzilli, (IS), Italy
| | - Aldo Giovannelli
- Department of Applied Clinical and Biotechnological Sciences, University of L'Aquila, L'Aquila, Italy
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), the Netherlands
| | - Eleonora Palma
- Department of Physiology and Pharmacology, laboratory affiliated to Istituto Pasteur Italia, University of Rome Sapienza, Rome, Italy.
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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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10
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Baker MD, Abou-Khalil BW, Arain A, Tummala P, Azar NJ, Haas KF, Sonmezturk HH. Lacosamide efficacy and tolerability in clinical practice – Post marketing analysis from a single dedicated epilepsy center. Clin Neurol Neurosurg 2018; 171:179-183. [DOI: 10.1016/j.clineuro.2018.06.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 12/27/2022]
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11
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Lu W, Feng J, Wen B, Wang K, Wang JH. Activity-induced spontaneous spikes in GABAergic neurons suppress seizure discharges: an implication of computational modeling. Oncotarget 2018; 8:32384-32397. [PMID: 28427143 PMCID: PMC5464796 DOI: 10.18632/oncotarget.15660] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/13/2017] [Indexed: 11/28/2022] Open
Abstract
Background Epilepsy, a prevalent neurological disorder, appears self-termination. The endogenous mechanism for seizure self-termination remains to be addressed in order to develop new strategies for epilepsy treatment. We aim to examine the role of activity-induced spontaneous spikes at GABAergic neurons as an endogenous mechanism in the seizure self-termination. Methods and Results Neuronal spikes were induced by depolarization pulses at cortical GABAergic neurons from temporal lobe epilepsy patients and mice, in which some of these neurons fired activity-induced spontaneous spikes. Neural networks including excitatory and inhibitory neurons were computationally constructed, and their functional properties were based on our studies from whole-cell recordings. With the changes in the portion and excitability of inhibitory neurons that generated activity-induced spontaneous spike, the efficacies to suppress synchronous seizure activity were analyzed, such as its onset time, decay slope and spike frequency. The increases in the proportion and excitability of inhibitory neurons that generated activity-induced spontaneous spikes effectively suppressed seizure activity in neural networks. These factors synergistically strengthened the efficacy of seizure activity suppression. Conclusion Our study supports a notion that activity-induced spontaneous spikes in GABAergic neurons may be an endogenous mechanism for seizure self-termination. A potential therapeutic strategy for epilepsy is to upregulate the cortical inhibitory neurons that generate activity-induced spontaneous spikes.
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Affiliation(s)
- Wei Lu
- Qingdao University, School of Pharmacy, Qingdao, Shandong, China
| | - Jing Feng
- Qingdao University, School of Pharmacy, Qingdao, Shandong, China.,State Key Lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Bo Wen
- State Key Lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kewei Wang
- Qingdao University, School of Pharmacy, Qingdao, Shandong, China
| | - Jin-Hui Wang
- Qingdao University, School of Pharmacy, Qingdao, Shandong, China.,State Key Lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
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12
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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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13
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Işık U, Saltık S, Tanrıkulu B, Özek MM. Hypothalamic hamartoma presenting with infantile spasms. Childs Nerv Syst 2017; 33:2197-2200. [PMID: 28762039 DOI: 10.1007/s00381-017-3559-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/20/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hypothalamic hamartomas (HH) generally present with gelastic seizures. It is very unusual for a pediatric patient with HH to present with infantile spasms (IS). CASE PRESENTATION Here we present a 6-month-old boy diagnosed with IS whose brain magnetic resonance imaging (MRI) showed an 18 × 18 × 16 mm mass in the hypothalamus. His seizures did not respond to antiepileptic treatment with vigabatrin and valproic acid. He had disconnective surgery for HH. Immediately postoperatively, his seizures subsided and he has now been seizure-free for 2 years. CONCLUSION Although hypothalamic hamartomas generally present with gelastic seizures, they should also be considered in the differential diagnosis of infantile spasms.
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Affiliation(s)
- Uğur Işık
- Department of Pediatrics, Division of Pediatric Neurology, Acıbadem University School of Medicine, Istanbul, Turkey.
| | - Sema Saltık
- Cerrahpaşa School of Medicine, Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul, Turkey
| | - Bahattin Tanrıkulu
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Acıbadem University School of Medicine, Istanbul, Turkey
| | - M Memet Özek
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Acıbadem University School of Medicine, Istanbul, Turkey
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14
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Wang B, Ma J. The diagnosis and management of hypothalamic hamartomas in children. Chin Neurosurg J 2016. [DOI: 10.1186/s41016-016-0047-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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15
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Gazzerro E, Striano P. Gap Junctions and Epileptogenesis: No Laughing Matter. EBioMedicine 2016; 8:5-6. [PMID: 27428402 PMCID: PMC4919563 DOI: 10.1016/j.ebiom.2016.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 05/18/2016] [Indexed: 11/19/2022] Open
Affiliation(s)
- Elisabetta Gazzerro
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, "G. Gaslini" Institute, Genova, Italy.
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, "G. Gaslini" Institute, Genova, Italy; Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, G. Gaslini Institute, Genova, Italy
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Semaan S, Wu J, Gan Y, Jin Y, Li GH, Kerrigan JF, Chang YC, Huang Y. Hyperactivation of BDNF-TrkB signaling cascades in human hypothalamic hamartoma (HH): a potential mechanism contributing to epileptogenesis. CNS Neurosci Ther 2015; 21:164-72. [PMID: 25307426 PMCID: PMC6495156 DOI: 10.1111/cns.12331] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/20/2014] [Accepted: 09/04/2014] [Indexed: 01/26/2023] Open
Abstract
AIMS Although compelling evidence suggests that human hypothalamic hamartoma (HH) is intrinsically epileptogenic for gelastic seizures, the molecular mechanisms responsible for epileptogenesis within HH remain to be elucidated. The aim of this study was to test the hypothesis that hyperactivation of BDNF-TrkB signaling pathways in surgically resected HH tissue is a possible mechanism for downregulation of KCC2 expression, which in turn underlies GABA-mediated excitation within HH. METHODS Activation of three major BDNF-TrkB signaling pathways including MAPKs, Akt, and PLCγ1 were evaluated in surgically resected HH tissue (n = 14) versus human hypothalamic control tissue (n = 8) using combined methodologies of biochemistry, molecular biology, cell biology, and electrophysiology. RESULTS Our data show that compared with hypothalamic control tissue, in HH tissue, (i) activation of TrkB and expression of mature BDNF are elevated; (ii) MAPKs (including ERK1/2, p38, and JNK), Akt, and PLCγ1 are highly activated; (iii) KCC2 expression is downregulated; and (iv) pharmacological manipulation of TrkB signaling alters HH neuronal firing rate. CONCLUSION Our findings suggest that multiple BDNF-TrkB signaling pathways are activated in HH. They act independently or collaboratively to downregulate KCC2 expression, which is the key component for GABA-mediated excitation associated with gelastic seizures.
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Affiliation(s)
- Suzan Semaan
- St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
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Wu J, Gao M, Shen JX, Qiu SF, Kerrigan JF. Mechanisms of intrinsic epileptogenesis in human gelastic seizures with hypothalamic hamartoma. CNS Neurosci Ther 2014; 21:104-11. [PMID: 25495642 DOI: 10.1111/cns.12348] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 10/07/2014] [Accepted: 10/08/2014] [Indexed: 12/24/2022] Open
Abstract
Human hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are refractory to medical therapy. Ictal EEG recordings from the HH have demonstrated that the epileptic source of gelastic seizures lies within the HH lesion itself. Recent advances in surgical techniques targeting HH have led to dramatic improvements in seizure control, which further supports the hypothesis that gelastic seizures originate within the HH. However, the basic cellular and molecular mechanisms of epileptogenesis in this subcortical lesion are poorly understood. Since 2003, Barrow Neurological Institute has maintained a multidisciplinary clinical program to evaluate and treat patients with HH. This program has provided a unique opportunity to investigate the basic mechanisms of epileptogenesis using surgically resected HH tissue. The first report on the electrophysiological properties of HH neurons was published in 2005. Since then, ongoing research has provided additional insights into the mechanisms by which HH generate seizure activity. In this review, we summarize this progress and propose a cellular model that suggests that GABA-mediated excitation contributes to epileptogenesis in HH lesions.
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Affiliation(s)
- Jie Wu
- Division of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA; Department of Physiology, Shantou University of Medical College, Shantou, Guangdong, China; Department of Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
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Wen B, Qian H, Feng J, Ge RJ, Xu X, Cui ZQ, Zhu RY, Pan LS, Lin ZP, Wang JH. A portion of inhibitory neurons in human temporal lobe epilepsy are functionally upregulated: an endogenous mechanism for seizure termination. CNS Neurosci Ther 2014; 21:204-14. [PMID: 25475128 DOI: 10.1111/cns.12336] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/15/2014] [Accepted: 09/18/2014] [Indexed: 01/08/2023] Open
Abstract
MAIN PROBLEM Epilepsy is one of the more common neurological disorders. The medication is often ineffective to the patients suffering from intractable temporal lobe epilepsy (TLE). As their seizures are usually self-terminated, the elucidation of the mechanism underlying endogenous seizure termination will help to find a new strategy for epilepsy treatment. We aim to examine the role of inhibitory interneurons in endogenous seizure termination in TLE patients. METHODS Whole-cell recordings were conducted on inhibitory interneurons in seizure-onset cortices of intractable TLE patients and the temporal lobe cortices of nonseizure individuals. The intrinsic property of the inhibitory interneurons and the strength of their GABAergic synaptic outputs were measured. The quantitative data were introduced into the computer-simulated neuronal networks to figure out a role of these inhibitory units in the seizure termination. RESULTS In addition to functional downregulation, a portion of inhibitory interneurons in seizure-onset cortices were upregulated in encoding the spikes and controlling their postsynaptic neurons. A patch-like upregulation of inhibitory neurons in the local network facilitated seizure termination. The upregulations of both inhibitory neurons and their output synapses synergistically shortened seizure duration, attenuated seizure strength, and terminated seizure propagation. CONCLUSION Automatic seizure termination is likely due to the fact that a portion of the inhibitory neurons and synapses are upregulated in the seizure-onset cortices. This mechanism may create novel therapeutic strategies to treat intractable epilepsy, such as the simultaneous upregulation of cortical inhibitory neurons and their output synapses.
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Affiliation(s)
- Bo Wen
- State Key lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
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Steinmetz PN, Wait SD, Lekovic GP, Rekate HL, Kerrigan JF. Firing behavior and network activity of single neurons in human epileptic hypothalamic hamartoma. Front Neurol 2013; 4:210. [PMID: 24409165 PMCID: PMC3873534 DOI: 10.3389/fneur.2013.00210] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/11/2013] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE Human hypothalamic hamartomas (HH) are intrinsically epileptogenic and are associated with treatment-resistant gelastic seizures. The basic cellular mechanisms responsible for seizure onset within HH are unknown. We used intra-operative microwire recordings of single neuron activity to measure the spontaneous firing rate of neurons and the degree of functional connection between neurons within the tumor. TECHNIQUE Fourteen patients underwent transventricular endoscopic resection of HH for treatment-resistant epilepsy. Prior to surgical resection, single neuron recordings from bundled microwires (total of nine contacts) were obtained from HH tissue. Spontaneous activity was recorded for two or three 5-min epochs under steady-state general anesthesia. Off-line analysis included cluster analysis of single unit activity and probability analysis of firing relationships between pairs of neurons. RESULTS Altogether, 222 neurons were identified (mean 6 neurons per recording epoch). Cluster analysis of single neuron firing utilizing a mixture of Gaussians model identified two distinct populations on the basis of firing rate (median firing frequency 0.6 versus 15.0 spikes per second; p < 10(-5)). Cluster analysis identified three populations determined by levels of burst firing (median burst indices of 0.015, 0.18, and 0.39; p < 10(-15)). Unbiased analysis of spontaneous single unit behavior showed that 51% of all possible neuron pairs within each recording epoch had a significant level of firing synchrony (p < 10(-15)). The subgroup of neurons with higher median firing frequencies was more likely to demonstrate synchronous firing (p < 10(-7)). CONCLUSION Hypothalamic hamartoma tissue in vivo contains neurons which fire spontaneously. The activity of single neurons is diverse but distributes into at least two electrophysiological phenoytpes. Functional linkage between single neurons suggests that HH neurons exist within local networks that may contribute to ictogenesis.
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Affiliation(s)
- Peter N. Steinmetz
- Comprehensive Epilepsy Center, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
| | - Scott D. Wait
- Carolina Neurosurgery and Spine Associates, Levine Children’s Hospital, Carolinas Medical Center, Charlotte, NC, USA
| | - Gregory P. Lekovic
- House Ear Institute, University of Southern California School of Medicine, Los Angeles, CA, USA
| | - Harold L. Rekate
- The Chiari Institute, Hofstra Northshore LIJ College of Medicine, Great Neck, NY, USA
| | - John F. Kerrigan
- Comprehensive Epilepsy Center, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA
- Division of Pediatric Neurology, Barrow Neurological Institute at Phoenix Children’s Hospital, Phoenix, AZ, USA
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Roseti C, Fucile S, Lauro C, Martinello K, Bertollini C, Esposito V, Mascia A, Catalano M, Aronica E, Limatola C, Palma E. Fractalkine/CX3CL1 modulates GABAA currents in human temporal lobe epilepsy. Epilepsia 2013; 54:1834-44. [PMID: 24032743 DOI: 10.1111/epi.12354] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE The chemokine fractalkine/CX3CL1 and its receptor CX3CR1 are widely expressed in the central nervous system (CNS). Recent evidence showed that CX3CL1 participates in inflammatory responses that are common features of CNS disorders, such as epilepsy. Mesial temporal lobe epilepsy (MTLE) is the prevalent form of focal epilepsy in adults, and hippocampal sclerosis (HS) represents the most common underlying pathologic abnormality, as demonstrated at autopsy and postresection studies. Relevant features of MTLE are a characteristic pattern of neuronal loss, as are astrogliosis and microglia activation. Several factors affect epileptogenesis in patients with MTLE, including a lack of γ-aminobutyric acid (GABA)ergic inhibitory efficacy. Therefore, experiments were designed to investigate whether, in MTLE brain tissues, CX3CL1 may influence GABAA receptor (GABAA R) mediated transmission, with a particular focus on the action of CX3CL1 on the use-dependent decrease (rundown) of the GABA-evoked currents (IGABA ), a feature underlying the reduction of GABAergic function in epileptic tissue. METHODS Patch-clamp recordings were obtained from cortical pyramidal neurons in slices from six MTLE patients after surgery. Alternatively, the cell membranes from epileptic brain tissues of 17 MTLE patients or from surgical samples and autopsies of nonepileptic patients were microtransplanted into Xenopus oocytes, and IGABA were recorded using the standard two-microelectrode voltage-clamp technique. Immunohistochemical staining and double-labeling studies were carried out on the same brain tissues to analyze CX3CR1 expression. KEY FINDINGS In native pyramidal neurons from cortical slices of patients with MTLE, CX3CL1 reduced IGABA rundown and affected the recovery of IGABA amplitude from rundown. These same effects were confirmed in oocytes injected with cortical and hippocampal MTLE membranes, whereas CX3CL1 did not influence IGABA in oocytes injected with nonepileptic tissues. Consistent with a specific effect of CX3CL1 on tissues from patients with MTLE, CX3CR1 immunoreactivity was higher in MTLE sclerotic hippocampi than in control tissues, with a prominent expression in activated microglial cells. SIGNIFICANCE These findings indicate a role for CX3CL1 in MTLE, supporting recent evidence on the relevance of brain inflammation in human epilepsies. Our data demonstrate that in MTLE tissues the reduced GABAergic function can be modulated by CX3CL1. The increased CX3CR1 expression in microglia and the modulation by CX3CL1 of GABAergic currents in human epileptic brain suggests new therapeutic approaches for drug-resistant epilepsies based on the evidence that the propagation of seizures can be influenced by inflammatory processes.
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Pati S, Sollman M, Fife TD, Ng YT. Diagnosis and management of epilepsy associated with hypothalamic hamartoma: an evidence-based systematic review. J Child Neurol 2013; 28:909-16. [PMID: 23670254 DOI: 10.1177/0883073813488673] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The main objective was to review the evidence for management of epilepsy associated with hypothalamic hamartomas. We performed a systemic review of the literature through July 2012 that studied patients with hypothalamic hamartomas and related epilepsy. Articles meeting selection criteria were rated according to the American Academy of Neurology classification of evidence scheme. Recommendations were linked to the strength of the evidence and as follows: (a) precocious puberty is associated more with the pedunculated type and epilepsy typified by gelastic seizures with the sessile form of hypothalamic hamartomas (class III); (b) significant behavioral and cognitive deficits are associated with patients with hypothalamic hamartomas (class III); (c) video electroencephalography (EEG) findings are extremely variable particularly across the different ages and do not affect surgical outcome (class III); d) various surgical techniques (transcallosal and endoscopic resection) resulted in 49% to 54% seizure freedom, 15% with a pterional approach as well as about 40% with radiosurgery (class III).
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Affiliation(s)
- Sandipan Pati
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02411, USA.
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Lennox-Gastaut syndrome symptomatic to hypothalamic hamartoma: evolution and long-term outcome following surgery. Pediatr Neurol 2013; 49:25-30. [PMID: 23827423 DOI: 10.1016/j.pediatrneurol.2013.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 03/15/2013] [Accepted: 03/19/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND Lennox-Gastaut syndrome is a catastrophic childhood cryptogenic or symptomatic epilepsy. Hypothalamic hamartomas cause refractory epilepsy often consistent with Lennox-Gastaut syndrome. METHODS Children with Lennox-Gastaut syndrome were defined by a triad of multiple generalized seizure types, slow spike-and-wave on EEG, and mental retardation. RESULTS Twenty-one of 159 hypothalamic hamartoma patients (14%) met the diagnostic criteria of Lennox-Gastaut syndrome. The median age of patients at epilepsy onset was 0.9 years (range, birth to 9 years). Six of the 21 patients (28%) had preceding infantile spasms. All patients underwent different surgical approaches, including endoscopic, transcallosal, orbitozygomatic resections, and radiosurgery treatment. Five of the 21 (24%) were seizure free with an additional 9 (42%) having at least >90% seizure reduction. Only 1 patient was not effectively treated (<50% seizure reduction). Eighty-eight percent of parents reported improvement in behavioral functioning. Shorter duration of epilepsy prior to surgery was a significant predictor of surgical outcome. CONCLUSIONS Patients with Lennox-Gastaut syndrome symptomatic to hypothalamic hamartomas have better postsurgical outcome due to other etiologies compared with cryptogenic and symptomatic Lennox-Gastaut syndrome patients. However, compared with overall hypothalamic hamartomas postsurgical outcomes, this cohort was less favorable. Earlier surgery may lead to better outcomes.
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Striano S, Santulli L, Ianniciello M, Ferretti M, Romanelli P, Striano P. The gelastic seizures-hypothalamic hamartoma syndrome: facts, hypotheses, and perspectives. Epilepsy Behav 2012; 24:7-13. [PMID: 22503469 DOI: 10.1016/j.yebeh.2012.02.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 02/12/2012] [Accepted: 02/14/2012] [Indexed: 11/15/2022]
Abstract
Hypothalamic hamartoma (HH) can be associated with a wide spectrum of epileptic conditions, ranging from a mild form with seizures characterized by urge to laugh and no cognitive involvement up to a catastrophic encephalopathy with early onset gelastic seizures (GS), precocious puberty, and mental retardation. Moreover, a refractory, either focal or generalized, epilepsy develops during the clinical course in nearly all the cases. Neurophysiologic and neuroimaging studies have demonstrated that HH itself generates GS and starts a process of secondary epileptogenesis responsible for refractory focal or generalized epilepsy. The intrinsic epileptogenicity of HH may be explained by the neurophysiological properties of small GABAergic, spontaneously firing HH neurons. Surgical ablation of HH can reverse epilepsy and encephalopathy. Gamma-knife radiosurgery and image-guided robotic radiosurgery seem to be useful and safe approaches for treatment, in particular of small HH. Here, we review this topic, based on literature reports and our personal observations. In addition, we discuss pathogenetic hypotheses and suggest new approaches to this intriguing issue.
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Affiliation(s)
- Salvatore Striano
- Epilepsy Center, Department of Neurological Sciences, Federico II University, Napoli, Italy.
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