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Vizuete AFK, Leal MB, Moreira AP, Seady M, Taday J, Gonçalves CA. Arundic acid (ONO-2506) downregulates neuroinflammation and astrocyte dysfunction after status epilepticus in young rats induced by Li-pilocarpine. Prog Neuropsychopharmacol Biol Psychiatry 2023; 123:110704. [PMID: 36565981 DOI: 10.1016/j.pnpbp.2022.110704] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 08/08/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Astrocytes, the most abundant glial cells, have several metabolic functions, including ionic, neurotransmitter and energetic homeostasis for neuronal activity. Reactive astrocytes and their dysfunction have been associated with several brain disorders, including the epileptogenic process. Glial Fibrillary Acidic Protein (GFAP) and S100 calcium-binding protein B (S100B) are astrocyte biomarkers associated with brain injury. We hypothesize that arundic acid (ONO-2506), which is known as an inhibitor of S100B synthesis and secretion, protects the hippocampal tissue from neuroinflammation and astrocyte dysfunction after status epileptics (SE) induction by Li-pilocarpine in young rats. Herein, we investigated the effects of arundic acid treatment, at time points of 6 or 24 h after the induction of SE by Li-pilocarpine, in young rats. In SE animals, arundic acid was able to prevent the damage induced by Li-pilocarpine in the hippocampus, decreasing neuroinflammatory signaling (reducing IL-1β, COX2, TLR4 and RAGE contents), astrogliosis (decreasing GFAP and S100B) and astrocytic dysfunction (recovering levels of GSH, glutamine synthetase and connexin-43). Furthermore, arundic acid improved glucose metabolism and reduced the glutamate excitotoxicity found in epilepsy. Our data reinforce the role of astrocytes in epileptogenesis development and the neuroprotective role of arundic acid, which modulates astrocyte function and neuroinflammation in SE animals.
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Affiliation(s)
- Adriana Fernanda K Vizuete
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil.
| | - Miriara B Leal
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil
| | - Ana Paula Moreira
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil
| | - Marina Seady
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil
| | - Jéssica Taday
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil
| | - Carlos-Alberto Gonçalves
- Laboratory of Calcium-Binding Proteins in CNS, Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; Pos Graduate Program in Biochemistry, Institute of Basic Health Sciences, UFRGS, Porto Alegre, RS, Brazil
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Andrioli A, Fabene PF, Mudò G, Barresi V, Di Liberto V, Frinchi M, Bentivoglio M, Condorelli DF. Downregulation of the Astroglial Connexin Expression and Neurodegeneration after Pilocarpine-Induced Status Epilepticus. Int J Mol Sci 2022; 24:ijms24010023. [PMID: 36613467 PMCID: PMC9819917 DOI: 10.3390/ijms24010023] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Astrocytic networks and gap junctional communication mediated by connexins (Cxs) have been repeatedly implicated in seizures, epileptogenesis, and epilepsy. However, the effect of seizures on Cx expression is controversial. The present study focused on the response of Cxs to status epilepticus (SE), which is in turn an epileptogenic insult. The expression of neuronal Cx36 and astrocytic Cx30 and Cx43 mRNAs was investigated in the brain of rats in the first day after pilocarpine-induced SE. In situ hybridization revealed a progressive decrease in Cx43 and Cx30 mRNA levels, significantly marked 24 h after SE onset in neocortical areas and the hippocampus, and in most thalamic domains, whereas Cx36 mRNA did not exhibit obvious changes. Regional evaluation with quantitative real-time-RT-PCR confirmed Cx43 and Cx30 mRNA downregulation 24 h after SE, when ongoing neuronal cell death was found in the same brain regions. Immunolabeling showed at the same time point marked a decrease in Cx43, microglia activation, and interleukin-1β induction in some microglial cells. The data showed a transient downregulation of astroglial Cxs in the cortical and thalamic areas in which SE triggers neurodegenerative events in concomitance with microglia activation and cytokine expression. This could potentially represent a protective response of neuroglial networks to SE-induced acute damage.
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Affiliation(s)
- Anna Andrioli
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Paolo Francesco Fabene
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
- Verona Unit, National Institute of Neuroscience (INN), 37129 Verona, Italy
| | - Giuseppa Mudò
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Vincenza Barresi
- Unit of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Valentina Di Liberto
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Monica Frinchi
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BiND), University of Palermo, 90133 Palermo, Italy
| | - Marina Bentivoglio
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
- Verona Unit, National Institute of Neuroscience (INN), 37129 Verona, Italy
| | - Daniele Filippo Condorelli
- Unit of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
- Correspondence:
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Fukuyama K, Okada M. Brivaracetam and Levetiracetam Suppress Astroglial L-Glutamate Release through Hemichannel via Inhibition of Synaptic Vesicle Protein. Int J Mol Sci 2022; 23:ijms23094473. [PMID: 35562864 PMCID: PMC9101419 DOI: 10.3390/ijms23094473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/18/2022] [Accepted: 04/18/2022] [Indexed: 02/07/2023] Open
Abstract
To explore the pathophysiological mechanisms of antiseizure and adverse behavioural/psychiatric effects of brivaracetam and levetiracetam, in the present study, we determined the effects of brivaracetam and levetiracetam on astroglial L-glutamate release induced by artificial high-frequency oscillation (HFO) bursts using ultra-high-performance liquid chromatography. Additionally, the effects of brivaracetam and levetiracetam on protein expressions of connexin43 (Cx43) and synaptic vesicle protein 2A (SV2A) in the plasma membrane of primary cultured rat astrocytes were determined using a capillary immunoblotting system. Acutely artificial fast-ripple HFO (500 Hz) burst stimulation use-dependently increased L-glutamate release through Cx43-containing hemichannels without affecting the expression of Cx43 or SV2A in the plasma membrane, whereas acute physiological ripple HFO (200 Hz) stimulation did not affect astroglial L-glutamate release or expression of Cx43 or SV2A. Contrarily, subchronic ripple HFO and acute pathological fast-ripple HFO (500 Hz) stimulations use-dependently increased L-glutamate release through Cx43-containing hemichannels and Cx43 expression in the plasma membrane. Subchronic fast-ripple HFO-evoked stimulation produced ectopic expression of SV2A in the plasma membrane, but subchronic ripple HFO stimulation did not generate ectopic SV2A. Subchronic administration of brivaracetam and levetiracetam concentration-dependently suppressed fast-ripple HFO-induced astroglial L-glutamate release and expression of Cx43 and SV2A in the plasma membrane. In contrast, subchronic ripple HFO-evoked stimulation induced astroglial L-glutamate release, and Cx43 expression in the plasma membrane was inhibited by subchronic levetiracetam administration, but was not affected by brivaracetam. These results suggest that brivaracetam and levetiracetam inhibit epileptogenic fast-ripple HFO-induced activated astroglial transmission associated with hemichannels. In contrast, the inhibitory effect of therapeutic-relevant concentrations of levetiracetam on physiological ripple HFO-induced astroglial responses probably contributes to the adverse behavioural/psychiatric effects of levetiracetam.
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García-Rodríguez C, Bravo-Tobar ID, Duarte Y, Barrio LC, Sáez JC. Contribution of non-selective membrane channels and receptors in epilepsy. Pharmacol Ther 2021; 231:107980. [PMID: 34481811 DOI: 10.1016/j.pharmthera.2021.107980] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/14/2022]
Abstract
Overcoming refractory epilepsy's resistance to the combination of antiepileptic drugs (AED), mitigating side effects, and preventing sudden unexpected death in epilepsy are critical goals for therapy of this disorder. Current therapeutic strategies are based primarily on neurocentric mechanisms, overlooking the participation of astrocytes and microglia in the pathophysiology of epilepsy. This review is focused on a set of non-selective membrane channels (permeable to ions and small molecules), including channels and ionotropic receptors of neurons, astrocytes, and microglia, such as: the hemichannels formed by Cx43 and Panx1; the purinergic P2X7 receptors; the transient receptor potential vanilloid (TRPV1 and TRPV4) channels; calcium homeostasis modulators (CALHMs); transient receptor potential canonical (TRPC) channels; transient receptor potential melastatin (TRPM) channels; voltage-dependent anion channels (VDACs) and volume-regulated anion channels (VRACs), which all have in common being activated by epileptic activity and the capacity to exacerbate seizure intensity. Specifically, we highlight evidence for the activation of these channels/receptors during epilepsy including neuroinflammation and oxidative stress, discuss signaling pathways and feedback mechanisms, and propose the functions of each of them in acute and chronic epilepsy. Studying the role of these non-selective membrane channels in epilepsy and identifying appropriate blockers for one or more of them could provide complementary therapies to better alleviate the disease.
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Affiliation(s)
- Claudia García-Rodríguez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
| | - Iván D Bravo-Tobar
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile
| | - Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Luis C Barrio
- Hospital Ramon y Cajal-IRYCIS, Centro de Tecnología Biomédica de la Universidad Politécnica, Madrid, Spain
| | - Juan C Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
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Brunal AA, Clark KC, Ma M, Woods IG, Pan YA. Effects of Constitutive and Acute Connexin 36 Deficiency on Brain-Wide Susceptibility to PTZ-Induced Neuronal Hyperactivity. Front Mol Neurosci 2021; 13:587978. [PMID: 33505244 PMCID: PMC7829467 DOI: 10.3389/fnmol.2020.587978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
Connexins are transmembrane proteins that form hemichannels allowing the exchange of molecules between the extracellular space and the cell interior. Two hemichannels from adjacent cells dock and form a continuous gap junction pore, thereby permitting direct intercellular communication. Connexin 36 (Cx36), expressed primarily in neurons, is involved in the synchronous activity of neurons and may play a role in aberrant synchronous firing, as seen in seizures. To understand the reciprocal interactions between Cx36 and seizure-like neural activity, we examined three questions: (a) does Cx36 deficiency affect seizure susceptibility, (b) does seizure-like activity affect Cx36 expression patterns, and (c) does acute blockade of Cx36 conductance increase seizure susceptibility. We utilize the zebrafish pentylenetetrazol [PTZ; a GABA(A) receptor antagonist] induced seizure model, taking advantage of the compact size and optical translucency of the larval zebrafish brain to assess how PTZ affects brain-wide neuronal activity and Cx36 protein expression. We exposed wild-type and genetic Cx36-deficient (cx35.5-/-) zebrafish larvae to PTZ and subsequently mapped neuronal activity across the whole brain, using phosphorylated extracellular-signal-regulated kinase (pERK) as a proxy for neuronal activity. We found that cx35.5-/- fish exhibited region-specific susceptibility and resistance to PTZ-induced hyperactivity compared to wild-type controls, suggesting that genetic Cx36 deficiency may affect seizure susceptibility in a region-specific manner. Regions that showed increased PTZ sensitivity include the dorsal telencephalon, which is implicated in human epilepsy, and the lateral hypothalamus, which has been underexplored. We also found that PTZ-induced neuronal hyperactivity resulted in a rapid reduction of Cx36 protein levels within 30 min. This Cx36 reduction persists after 1-h of recovery but recovered after 3–6 h. This acute downregulation of Cx36 by PTZ is likely maladaptive, as acute pharmacological blockade of Cx36 by mefloquine results in increased susceptibility to PTZ-induced neuronal hyperactivity. Together, these results demonstrate a reciprocal relationship between Cx36 and seizure-associated neuronal hyperactivity: Cx36 deficiency contributes region-specific susceptibility to neuronal hyperactivity, while neuronal hyperactivity-induced downregulation of Cx36 may increase the risk of future epileptic events.
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Affiliation(s)
- Alyssa A Brunal
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA, United States.,Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, VA, United States
| | - Kareem C Clark
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA, United States
| | - Manxiu Ma
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA, United States
| | - Ian G Woods
- Department of Biology, Ithaca College, Ithaca, NY, United States
| | - Y Albert Pan
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA, United States.,Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, United States.,Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, United States
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Astrocytic Connexin43 Channels as Candidate Targets in Epilepsy Treatment. Biomolecules 2020; 10:biom10111578. [PMID: 33233647 PMCID: PMC7699773 DOI: 10.3390/biom10111578] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
In epilepsy research, emphasis is put on exploring non-neuronal targets such as astrocytic proteins, since many patients remain pharmacoresistant to current treatments, which almost all target neuronal mechanisms. This paper reviews available data on astrocytic connexin43 (Cx43) signaling in seizures and epilepsy. Cx43 is a widely expressed transmembrane protein and the constituent of gap junctions (GJs) and hemichannels (HCs), allowing intercellular and extracellular communication, respectively. A plethora of research papers show altered Cx43 mRNA levels, protein expression, phosphorylation state, distribution and/or functional coupling in human epileptic tissue and experimental models. Human Cx43 mutations are linked to seizures as well, as 30% of patients with oculodentodigital dysplasia (ODDD), a rare genetic condition caused by mutations in the GJA1 gene coding for Cx43 protein, exhibit neurological symptoms including seizures. Cx30/Cx43 double knock-out mice show increased susceptibility to evoked epileptiform events in brain slices due to impaired GJ-mediated redistribution of K+ and glutamate and display a higher frequency of spontaneous generalized chronic seizures in an epilepsy model. Contradictory, Cx30/Cx43 GJs can traffic nutrients to high-energy demanding neurons and initiate astrocytic Ca2+ waves and hyper synchronization, thereby supporting proconvulsant effects. The general connexin channel blocker carbenoxolone and blockers from the fenamate family diminish epileptiform activity in vitro and improve seizure outcome in vivo. In addition, interventions with more selective peptide inhibitors of HCs display anticonvulsant actions. To conclude, further studies aiming to disentangle distinct roles of HCs and GJs are necessary and tools specifically targeting Cx43 HCs may facilitate the search for novel epilepsy treatments.
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Shu Y, Zhu C, Zeng M, Zhan Q, Hu Z, Wu X. The protective effect of carbenoxolone on gap junction damage in the hippocampal CA1 area of a temporal lobe epilepsy rat model. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:624. [PMID: 31930025 DOI: 10.21037/atm.2019.11.04] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Astrocytes are one of the most important types of neural cells in the central nervous system (CNS). Dysfunctional gap junction (GJ) communication could play an underlying role in epileptogenesis. Carbenoxolone (CBX) is a conventional chemical GJ blocker, and its target is connexin 43 (Cx43). Previous studies have shown that CBX can inhibit status epilepticus (SE) and spontaneous epileptic seizures (SESs). However, there is little information about the direct interaction between CBX and Cxs in temporal lobe epilepsy (TLE). Methods The behavior of epileptic rats was observed. Moreover, micromorphological changes in the hippocampal cornu ammonis 1 (CA1) area of epileptic rats following CBX injection were determined through transmission electron microscopy (TEM). To illustrate the possible mechanism of these changes, the Western blot method was used. Results After the injection of CBX, the seizure frequency, seizure duration, latency period to the first instance of SES, SESs behavioral score according to a scoring system developed by Velíšková and microstructures in the CA1 area were shown to be improved 60 days after SE by TEM. Furthermore, the dynamic expression patterns of Cx43 and Cx43 phosphorylated at Ser368 continuously declined after the injection of CBX until 60 days after SE. Conclusions CBX may contribute to the improvement of GJ dysfunction during epileptogenesis in the hippocampal CA1 area in a TLE rat model.
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Affiliation(s)
- Yi Shu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Can Zhu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Min Zeng
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Qiong Zhan
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Zhiping Hu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Xiaomei Wu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
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Li Q, Li QQ, Jia JN, Liu ZQ, Zhou HH, Mao XY. Targeting gap junction in epilepsy: Perspectives and challenges. Biomed Pharmacother 2018; 109:57-65. [PMID: 30396092 DOI: 10.1016/j.biopha.2018.10.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 12/21/2022] Open
Abstract
Gap junctions (GJs) are multiple cellular intercellular connections that allow ions to pass directly into the cytoplasm of neighboring cells. Electrical coupling mediated by GJs plays a role in the generation of highly synchronous electrical activity. Accumulative investigations show that GJs in the brain are involved in the generation, synchronization and maintenance of seizure events. At the same time, GJ blockers exert potent curative potential on epilepsy in vivo or in vitro. This review aims to shed light on the role of GJs in epileptogenesis. Targeting GJs is likely to be served as a novel therapeutic approach on epileptic patients.
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Affiliation(s)
- Qin Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Qiu-Qi Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Ji-Ning Jia
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Xiao-Yuan Mao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China.
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10
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Wu XL, Ma DM, Zhang W, Zhou JS, Huo YW, Lu M, Tang FR. Cx36 in the mouse hippocampus during and after pilocarpine-induced status epilepticus. Epilepsy Res 2018; 141:64-72. [PMID: 29476948 DOI: 10.1016/j.eplepsyres.2018.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/24/2018] [Accepted: 02/13/2018] [Indexed: 12/24/2022]
Abstract
Gap junctions play an important role in the synchronization activity of coupled cells. Hippocampal inhibitory interneurons are involved in epileptogenesis and seizure activity, and express gap junction protein connexin (Cx) 36. Cx36 is also localized in the axons (mossy fibers) of granule cells in the dentate gyrus. While it has been documented that Cx36 is involved in epileptogenesis, there are still controversies regarding the expression levels of Cx36 at different developmental stages of human and animal models of epileptogenesis. In this study, the expression of Cx36 was investigated in the mouse hippocampus at 1 h, 4 h during pilocarpine-induced status epilepticus (PISE) and 1 week, 2 months after PISE. We found that Cx36 was down-regulated in neurons at different time points during and after PISE, whereas it was increased significantly in the stratum lucidum of CA3 area at 2 months after PISE. Double immunofluorescence indicated that Cx36 was localized in parvalbumin (PV) immunopositive interneuron in CA1 area and in mossy fibers and their terminals in the stratum lucidum of CA3 area. It suggests that decreased expression of Cx36 in interneurons may be related to less effective inhibitory control of excitatory activity of hippocampal principal neurons. However, the increased Cx36 immunopositive product in mossy fibers at the chronic stage after PISE may enhance the contacts between granule cells in the dentate gyrus and pyramidal neurons in CA3 area. The two different changes of Cx36 may be implicated in the epileptogenesis.
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Affiliation(s)
- X L Wu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an, Shaanxi 710061, China
| | - D M Ma
- Department of Thoracic Surgery, The Ninth Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710054, China
| | - W Zhang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an, Shaanxi 710061, China
| | - J S Zhou
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an, Shaanxi 710061, China
| | - Y W Huo
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an, Shaanxi 710061, China
| | - M Lu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an, Shaanxi 710061, China
| | - F R Tang
- Radiation Physiology Laboratory, Singapore Nuclear Research and Safety Initiative (SNRSI), National University of Singapore, 1 CREATE Way #04-01, CREATE Tower 138602, Singapore.
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