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Sp1-Mediated Prdx6 Upregulation Leads to Clasmatodendrosis by Increasing Its aiPLA2 Activity in the CA1 Astrocytes in Chronic Epilepsy Rats. Antioxidants (Basel) 2022; 11:antiox11101883. [PMID: 36290607 PMCID: PMC9598987 DOI: 10.3390/antiox11101883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/13/2022] [Accepted: 09/19/2022] [Indexed: 11/29/2022] Open
Abstract
Clasmatodendrosis is an autophagic astroglial degeneration (a non-apoptotic (type II) programmed cell death) whose underlying mechanisms are fully understood. Peroxiredoxin-6 (Prdx6), the “non-selenium glutathione peroxidase (NSGPx)”, is the only member of the 1-cysteine peroxiredoxin family. Unlike the other Prdx family, Prdx6 has multiple functions as glutathione peroxidase (GPx) and acidic calcium-independent phospholipase (aiPLA2). The present study shows that Prdx6 was upregulated in CA1 astrocytes in chronic epilepsy rats. 2-Cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO-Me) and N-acetylcysteine (NAC, a precursor of glutathione) ameliorated clasmatodendrosis accompanied by reduced Prdx6 level in CA1 astrocytes. Specificity protein 1 (Sp1) expression was upregulated in CA1 astrocyte, which was inhibited by mithramycin A (MMA). MMA alleviated clasmatodendrosis and Prdx6 upregulation. Sp1 expression was also downregulated by CDDO-Me and NAC. Furthermore, 1-hexadecyl-3-(trifluoroethgl)-sn-glycerol-2 phosphomethanol (MJ33, a selective inhibitor of aiPLA2 activity of Prdx6) attenuated clasmatodendrosis without affecting Prdx6 expression. All chemicals shortened spontaneous seizure duration but not seizure frequency and behavioral seizure severity in chronic epilepsy rats. Therefore, our findings suggest that Sp1 activation may upregulate Prdx6, whose aiPLA2 activity would dominate over GPx activity in CA1 astrocytes and may lead to prolonged seizure activity due to autophagic astroglial degeneration.
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Laminin as a Biomarker of Blood-Brain Barrier Disruption under Neuroinflammation: A Systematic Review. Int J Mol Sci 2022; 23:ijms23126788. [PMID: 35743229 PMCID: PMC9224176 DOI: 10.3390/ijms23126788] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/03/2022] [Accepted: 06/10/2022] [Indexed: 01/01/2023] Open
Abstract
Laminin, a non-collagenous glycoprotein present in the brain extracellular matrix, helps to maintain blood–brain barrier (BBB) integrity and regulation. Neuroinflammation can compromise laminin structure and function, increasing BBB permeability. The aim of this paper is to determine if neuroinflammation-induced laminin functional changes may serve as a potential biomarker of alterations in the BBB. The 38 publications included evaluated neuroinflammation, BBB disruption, and laminin, and were assessed for quality and risk of bias (protocol registered in PROSPERO; CRD42020212547). We found that laminin may be a good indicator of BBB overall structural integrity, although changes in expression are dependent on the pathologic or experimental model used. In ischemic stroke, permanent vascular damage correlates with increased laminin expression (β and γ subunits), while transient damage correlates with reduced laminin expression (α subunits). Laminin was reduced in traumatic brain injury and cerebral hemorrhage studies but increased in multiple sclerosis and status epilepticus studies. Despite these observations, there is limited knowledge about the role played by different subunits or isoforms (such as 411 or 511) of laminin in maintaining structural architecture of the BBB under neuroinflammation. Further studies may clarify this aspect and the possibility of using laminin as a biomarker in different pathologies, which have alterations in BBB function in common.
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Kim JE, Lee DS, Kim TH, Kang TC. CDDO-Me Attenuates CA1 Neuronal Death by Facilitating RalBP1-Mediated Mitochondrial Fission and 4-HNE Efflux in the Rat Hippocampus Following Status Epilepticus. Antioxidants (Basel) 2022; 11:985. [PMID: 35624848 PMCID: PMC9137584 DOI: 10.3390/antiox11050985] [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: 03/23/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022] Open
Abstract
Ras-related protein Ral-A (RalA)-binding protein 1 (RalBP1, also known as Ral-interacting protein of 76 kDa (RLIP76) or Ral-interacting protein 1 (RLIP1 or RIP1)) is involved in the efflux of 4-hydroxynonenal (4-HNE, an end product of lipid peroxidation), as well as mitochondrial fission. In the present study, we found that 2-cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO-Me) attenuated CA1 neuronal death and aberrant mitochondrial elongations in these neurons coupled with enhanced RalBP1 expression and reduced 4-HNE levels following status epilepticus (SE). RalBP1 knockdown did not affect mitochondrial dynamics and CA1 neuronal death under physiological and post-SE conditions. Following SE, however, cotreatment of RalBP1 siRNA diminished the effect of CDDO-Me on 4-HNE levels, mitochondrial hyperfusion in CA1 neurons, and CA1 neuronal death. These findings indicate that CDDO-Me may ameliorate CA1 neuronal death by facilitating RalBP1-mediated 4-HNE efflux and mitochondrial fission following SE. Therefore, our findings suggest that increased RalBP1 expression/activity may be one of the considerable targets to protect neurons from SE.
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Affiliation(s)
| | | | | | - Tae-Cheon Kang
- Department of Anatomy and Neurobiology and Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.-E.K.); (D.-S.L.); (T.-H.K.)
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Mallmann MP, Mello FK, Neuberger B, Sobral KG, Fighera MR, Royes LFF, Furian AF, Oliveira MS. Beta-caryophyllene attenuates short-term recurrent seizure activity and blood-brain-barrier breakdown after pilocarpine-induced status epilepticus in rats. Brain Res 2022; 1784:147883. [PMID: 35300975 DOI: 10.1016/j.brainres.2022.147883] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/18/2022] [Accepted: 03/11/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Status epilepticus (SE) is a neurological life-threatening condition, resulting from the failure of the mechanisms responsible for seizure termination. SE is often pharmacoresistant and associated with significant morbidity and mortality. Hence, ceasing or attenuating SE and its consequences is of fundamental importance. Beta-caryophyllene is a functional CB2 receptor agonist and exhibit a good safety profile. Besides, it displays beneficial effects in several experimental conditions, including neuroprotective activity. In the present study we aimed to investigate the effects of beta-caryophyllene on pilocarpine-induced SE. METHODS Wistar rats were submitted to pilocarpine-induced SE and monitored for 24 hours by video and EEG for short-term recurrence of seizure activity (i.e. seizures occurring within 24 hours after termination of SE). Rats received beta-caryophyllene (100 mg/kg, ip) at 1, 8- and 16-hours after SE. Twenty-four hours after SE we evaluated sensorimotor response, neuronal damage (fluoro jade C staining) and serum albumin infiltration into brain parenchyma. RESULTS Beta-caryophyllene-treated animals presented fewer short-term recurrent seizures than vehicle-treated counterparts, suggesting an anticonvulsant effect after SE. Behavioral recovery from SE and the number of fluoro jade C positive cells in the hippocampus and thalamus were not modified by beta-caryophyllene. Treatment with beta-caryophyllene attenuated the SE-induced increase of albumin immunoreactivity in the hippocampus, indicating a protective effect against blood-brain-barrier breakdown. CONCLUSIONS Given the inherent difficulties in the treatment of SE and its consequences, present results suggest that beta-caryophyllene deserve further investigation as an adjuvant therapeutic strategy for SE.
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Affiliation(s)
| | | | - Bruna Neuberger
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil.
| | - Karine Gabriela Sobral
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil.
| | - Michele Rechia Fighera
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil.
| | - Luiz Fernando Freire Royes
- Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil.
| | - Ana Flávia Furian
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Food Science and Technology, Federal University of Santa Maria, Santa Maria, Brazil.
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Lévesque M, Biagini G, de Curtis M, Gnatkovsky V, Pitsch J, Wang S, Avoli M. The pilocarpine model of mesial temporal lobe epilepsy: Over one decade later, with more rodent species and new investigative approaches. Neurosci Biobehav Rev 2021; 130:274-291. [PMID: 34437936 DOI: 10.1016/j.neubiorev.2021.08.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/17/2021] [Accepted: 08/21/2021] [Indexed: 01/19/2023]
Abstract
Fundamental work on the mechanisms leading to focal epileptic discharges in mesial temporal lobe epilepsy (MTLE) often rests on the use of rodent models in which an initial status epilepticus (SE) is induced by kainic acid or pilocarpine. In 2008 we reviewed how, following systemic injection of pilocarpine, the main subsequent events are the initial SE, the latent period, and the chronic epileptic state. Up to a decade ago, rats were most often employed and they were frequently analysed only behaviorally. However, the use of transgenic mice has revealed novel information regarding this animal model. Here, we review recent findings showing the existence of specific neuronal events during both latent and chronic states, and how optogenetic activation of specific cell populations modulate spontaneous seizures. We also address neuronal damage induced by pilocarpine treatment, the role of neuroinflammation, and the influence of circadian and estrous cycles. Updating these findings leads us to propose that the rodent pilocarpine model continues to represent a valuable tool for identifying the basic pathophysiology of MTLE.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena & Reggio Emilia, 41100 Modena, Italy
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milano, Italy
| | - Vadym Gnatkovsky
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milano, Italy; Department of Epileptology, University Hospital Bonn, 53127 Bonn, Germany
| | - Julika Pitsch
- Department of Epileptology, University Hospital Bonn, 53127 Bonn, Germany
| | - Siyan Wang
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada; Departments of Physiology, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Experimental Medicine, Sapienza University of Rome, 00185 Roma, Italy.
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AlMuslamani A, Taha M. Thalamic Lesions in a Toddler with Glutamic Acid Decarboxylase Autoimmune Encephalitis. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0040-1716912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractWe present a child with glutamic acid decarboxylase (GAD) autoimmune encephalitis (AE) with bilateral thalamic lesions on magnetic resonance imaging (MRI) of the brain. A healthy 21-month-old girl, after superrefractory status epilepticus (SE) and fever developed dyskinesia and ataxia, which we subsequently diagnosed as GAD AE. She showed remarkable response to treatment with methylprednisolone and intravenous immunoglobulin (IVIg). Following an initial normal MRI of her brain, a further brain imaging showed bilateral thalamic lesions. This is an unusual finding since brain imaging abnormalities, when found in GAD AE, mostly involve the mesial temporal lobe structures. Thalamic lesions in GAD AE have not been reported previously.
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Affiliation(s)
- Ahood AlMuslamani
- Department of Pediatrics, King Hamad University Hospital, Muharraq, Kingdom of Bahrain
| | - Mohamed Taha
- Department of Pediatrics, King Hamad University Hospital, Muharraq, Kingdom of Bahrain
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Xu W, Zhang S, Feng Y, Zhang C, Xiao Y, Tian F. iTRAQ-based proteomic analysis of the hippocampus of pentylenetetrazole-kindled epileptic rats. Int J Dev Neurosci 2020; 81:125-141. [PMID: 33316100 DOI: 10.1002/jdn.10082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 11/24/2020] [Accepted: 12/09/2020] [Indexed: 11/06/2022] Open
Abstract
Epilepsy can severely affect the quality of life of patients, who are often at higher risk of mortality. However, the molecular mechanisms and pathogenesis underlying epileptogenesis are poorly understood. In this study, we performed a proteomic analysis of the hippocampus in pentylenetetrazole (PTZ)-kindled epileptic rats to explore the molecular mechanisms of epileptogenesis. We established an epileptic model in Sprague Dawley rats by injecting PTZ intraperitoneally and applied isobaric tags for relative and absolute quantification (iTRAQ) technology integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify differentially expressed proteins (DEPs) in the hippocampus. A total of 99 proteins, comprising 93 upregulated and 6 downregulated proteins, were identified based on a fold change >1.2 (or <0.83) and a p-value < .05. A further bioinformatics analysis suggested that the candidate proteins were mainly involved in the ubiquitin ligase complex or metabolite homeostasis or acted as intrinsic components of the membrane. A Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway enrichment analysis identified a series of representative pathological pathways, including the calcium signaling pathway, neuroactive ligand-receptor interaction pathway, and the NF-kappa B pathway. The mass spectrometry results were further confirmed by assessing five representative proteins (Akt1, Syvn1, Amfr, Lamb1, and Cox17) using western blotting and immunohistochemistry. These results may help to reveal the molecular mechanisms underlying epileptogenesis and provide new directions or targets for epilepsy research.
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Affiliation(s)
- Weiye Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Siyuan Zhang
- Department of Neurology, Hunan Provincial People's Hospital, Changsha, P.R. China
| | - Yanyan Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Chen Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Yeqing Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Fafa Tian
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
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Lee DS, Kim JE. PDI-Mediated Reduction of Disulfide Bond on PSD95 Increases Spontaneous Seizure Activity by Regulating NR2A-PSD95 Interaction in Epileptic Rats Independent of S-Nitrosylation. Int J Mol Sci 2020; 21:ijms21062094. [PMID: 32197489 PMCID: PMC7139850 DOI: 10.3390/ijms21062094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 01/17/2023] Open
Abstract
Postsynaptic density-95 (PSD95), a major scaffolding protein, is critical in coupling N-methyl-D-aspartate receptor (NMDAR) to cellular signaling networks in the central nervous system. A couple of cysteine residues in the N-terminus of PSD95 are potential sites for disulfide bonding, S-nitrosylation and/or palmitoylation. Protein disulfide isomerase (PDI) reduces disulfide bonds (S-S) to free thiol (-SH) on various proteins. However, the involvement of PDI in disulfide bond formation/S-nitrosylation of PSD95 and its role in epilepsy are still unknown. In the present study, acute seizure activity significantly increased the bindings of PDI to NR2A, but not to PSD95, while it decreased the NR2A–PSD95 binding. In addition, pilocarpine-induced seizures increased the amount of nitrosylated (SNO-) thiols, not total (free and SNO-) thiols, on PSD95. Unlike acute seizure, spontaneous seizing rats showed the increases in PDI–PSD95 binding, total- and SNO-thiol levels on PSD95, and NR2A–PSD95 interaction. PDI siRNA effectively reduced spontaneous seizure activity with decreases in total thiol level on PSD95 and NR2A–PSD95 association. These findings indicate that PDI-mediated reduction of disulfide-bond formations may facilitate the NR2A–PSD95 binding and contribute to spontaneous seizure generation in epileptic animals.
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Affiliation(s)
| | - Ji-Eun Kim
- Correspondence: ; Tel.: +82-33-248-2522; Fax: +82-33-248-2525
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9
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Mello FK, Freitas ML, Souto NS, Zorzi VN, Moreira MP, Neuberger B, Costa KG, Fighera MR, Royes LF, Furian AF, Oliveira MS. Neuroprotective effects of thromboxane receptor antagonist SQ 29,548 after pilocarpine-induced status epilepticus in mice. Epilepsy Res 2020; 160:106277. [PMID: 32036236 DOI: 10.1016/j.eplepsyres.2020.106277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/07/2019] [Accepted: 01/14/2020] [Indexed: 11/15/2022]
Abstract
Thromboxane A2 (TXA2) is an important eicosanoid in the cardiovascular system, and increasing evidence suggests that TXA2 receptors (TPs) and their ligands may constitute valuable tools for the development of neuroprotective drugs. However, the role of TPs on seizure-induced damage has not been investigated. Therefore, we evaluated the effects of SQ 29,548, a potent and selective TP antagonist-on neuromotor performance, neurodegeneration, reactive astrocytosis, and c-Fos protein immunoreactivity after pilocarpine-induced status epilepticus (SE) in mice. Adult C57BL/6 mice received intracerebroventricular SQ 29,548 injections 90 min and 24 h after pilocarpine-induced SE. We found that SQ 29,548 prevented the impairment of neuromotor performance (Neuroscore test) 48 h after pilocarpine-induced SE. Data analysis suggested the existence of two subgroups of SQ 29,548-treated post-SE animals. Eight out of 12 SQ 29,548-treated animals displayed Neuroscore values identical to those of vehicle-treated controls, and were considered SQ 29,548 responders. However, 4 out of 12 SQ 29,548-treated animals did not show any improvement in Neuroscore values, and were considered SQ 29,548 non-responders. Treatment with SQ 29,548 attenuated SE-induced increase in the number of FJC- or GFAP-positive cells in the hippocampus of SQ 29,548 responders. In addition, SQ 29,548 prevented the SE-elicited increase of c-Fos immunoreactivity in the hippocampus. In summary, our results suggest that the TP antagonist (SQ 29,548) improves neurological outcome after pilocarpine-induced SE in mice. The existence of SQ 29,548 responders and non-responders was suggested by results from the Neuroscore test. Additional studies are needed to understand the mechanisms underlying these findings, as well as the potential uses of TP antagonists in the treatment of seizure-induced damage.
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Affiliation(s)
| | | | - Naieli Schiefelbein Souto
- Graduate Program in Food Science and Technology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Viviane Nogueira Zorzi
- Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Bruna Neuberger
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Karine Gabriela Costa
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michele Rechia Fighera
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | - Luiz Fernando Royes
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Biological Sciences: Toxicological Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | - Ana Flávia Furian
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Food Science and Technology, Federal University of Santa Maria, Santa Maria, Brazil
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Similar Safety Profile of the Enantiomeric N-Aminoalkyl Derivatives of Trans-2-Aminocyclohexan-1-ol Demonstrating Anticonvulsant Activity. Molecules 2019; 24:molecules24132505. [PMID: 31323993 PMCID: PMC6651381 DOI: 10.3390/molecules24132505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/07/2019] [Accepted: 07/09/2019] [Indexed: 01/16/2023] Open
Abstract
Epilepsy is one of the most common neurological disorder in the world. Many antiepileptic drugs cause multiple adverse effects. Moreover, multidrug resistance is a serious problem in epilepsy treatment. In the present study we evaluated the safety profile of three (1–3) new chiral N-aminoalkyl derivatives of trans-2-aminocyclohexan-1-ol demonstrating anticonvulsant activity. Our aim was also to determine differences between the enantiomeric compounds with respect to their safety profile. The results of the study indicated that compounds 1–3 are non-cytotoxic for astrocytes, although they exhibit cytotoxic activity against human glioblastoma cells. Moreover, 1–3 did not affect the viability of HepG2 cells and did not produce adducts with glutathione. Compounds 1–3 demonstrated no mutagenic activity either in the Salmonella typhimurium or in Vibrio harveyi tests. Additionally, the compounds displayed a strong or moderate antimutagenic effect. Finally, the P-glycoprotein (P-gp) ATPase assay demonstrated that both enantiomers are potent P-gp inhibitors. To sum up, our results indicate that the newly synthesized derivatives may be considered promising candidates for further research on anticonvulsant drug discovery and development. Our study indicated the similar safety profile of the enantiomeric N-aminoalkyl derivatives of trans-2-aminocyclohexan-1-ol, although in the previous studies both enantiomers differ in their biotransformation pathways and pharmacological activity.
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Park H, Choi SH, Kong MJ, Kang TC. Dysfunction of 67-kDa Laminin Receptor Disrupts BBB Integrity via Impaired Dystrophin/AQP4 Complex and p38 MAPK/VEGF Activation Following Status Epilepticus. Front Cell Neurosci 2019; 13:236. [PMID: 31178701 PMCID: PMC6542995 DOI: 10.3389/fncel.2019.00236] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/09/2019] [Indexed: 12/21/2022] Open
Abstract
Status epilepticus (SE, a prolonged seizure activity) impairs brain-blood barrier (BBB) integrity, which results in secondary complications following SE. The non-integrin 67-kDa laminin receptor (67-kDa LR) plays a role in cell adherence to laminin (a major glycoprotein component in basement membrane), and participates laminin-mediated signaling pathways including p38 mitogen-activated protein kinase (p38 MAPK). Thus, we investigated the role of 67-kDa LR in SE-induced vasogenic edema formation in the rat piriform cortex (PC). SE diminished 67-kDa LR expression, but increased laminin expression, in endothelial cells accompanied by the reduced SMI-71 (a rat BBB barrier marker) expression. Astroglial 67-kDa LR expression was also reduced in the PC due to massive astroglial loss. 67-kDa LR neutralization led to serum extravasation in the PC concomitant with the reduced SMI-71 expression. 67-kDa LR neutralization also decreased expressions of dystrophin and aquaporin-4 (AQP4). In addition, it increased p38 MAPK phosphorylation and expressions of vascular endothelial growth factor (VEGF), laminin and endothelial nitric oxide synthase (eNOS), which were abrogated by SB202190, a p38 MAPK inhibitor. Therefore, our findings indicate that 67-kDa LR dysfunction may disrupt dystrophin-AQP4 complex, which would evoke vasogenic edema formation and subsequent laminin over-expression via activating p38 MAPK/VEGF axis.
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Affiliation(s)
- Hana Park
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, South Korea.,Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Seo-Hyeon Choi
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, South Korea.,Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Min-Jeong Kong
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, South Korea.,Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Tae-Cheon Kang
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, South Korea.,Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, South Korea
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12
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Neuroprotective effects of a protein tyrosine phosphatase inhibitor against hippocampal excitotoxic injury. Brain Res 2019; 1719:133-139. [PMID: 31128098 DOI: 10.1016/j.brainres.2019.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/07/2019] [Accepted: 05/21/2019] [Indexed: 11/23/2022]
Abstract
Neuronal excitotoxicity is the neuronal cell death arising from prolonged exposure to glutamate and the associated excessive influx of ions into the cell. Sodium orthovanadate (Na3VO4,) competitively inhibits the protein tyrosine phosphatases that affect intracellular protein phosphorylation. No study has examined the role of protein tyrosine phosphatases in kainic acid (KA)-induced excitotoxic injury using sodium orthovanadate. Thus, the present study was conducted to determine the neuroprotective effects of sodium orthovanadate on KA-induced neuronal death in organotypic hippocampal slice culture. We also performed an in vivo electrophysiology study in Sprague-Dawley rats to observe the function of surviving cells after sodium orthovanadate treatment in KA-induced excitotoxicity. Rats were anaesthetized with sodium pentobarbital and KA was injected unilaterally in CA3 of the hippocampus by microinjection-cannula. Neuronal cell death, as assessed by propidium iodide uptake, was reduced by 10 and 25 μM sodium orthovanadate treatment (24 and 48 h) compared with the KA-only group. Sodium orthovanadate enhanced survival signals by increasing levels of phospho-Akt and superoxide dismutase. In addition, sodium orthovanadate treatment reduced calcineurin level for neuronal protection, which regulates activation of cellular calcium caused by KA-induced injury. In vivo results showed that sodium orthovanadate treatment elicited resistance to KA-induced behavior seizures and significantly reduced the duration of epileptiform discharges. In addition, sodium orthovanadate treatment (25 mM) significantly prevented the increase in power spectra induced by KA injection. These results suggest that sodium orthovanadate decreases the acute effects of KA, thereby inducing neuroprotective effects with reduced reactive oxygen species and cellular Ca2+. Thus, sodium orthovanadate may protect hippocampal neurons against excitotoxicity, and surviving neurons may function to reduce seizures.
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13
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Iqbal R, Ahmed S, Jain GK, Vohora D. Design and development of letrozole nanoemulsion: A comparative evaluation of brain targeted nanoemulsion with free letrozole against status epilepticus and neurodegeneration in mice. Int J Pharm 2019; 565:20-32. [PMID: 31051232 DOI: 10.1016/j.ijpharm.2019.04.076] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 01/08/2023]
Abstract
The target of the current study is to formulate letrozole loaded nanoemulsion (LET-NE) for the direct nose to brain delivery to reduce peripheral effects of letrozole (LET). LET-NE is compared against intraperitoneally administered free LET in kainic acid (KA) induced status epilepticus (SE) in mice. LET loaded nanoemulsion (LET-NE) was prepared by aqueous microtitration method using Triacetin, Tween 80 and PEG-400 as the oil phase, surfactant, and co-surfactant. Nanoemulsion was studied for droplet size, polydispersity index (PDI), zeta potential, percentage transmittance, drug content, surface morphology. TEM images of developed formulation demonstrated spherical droplets with a mean diameter of 95.59 ± 2.34 nm, PDI of 0.162 ± 0.012 and zeta potential of -7.12 ± 0.12 mV respectively. In in-vitro and ex-vivo drug release, LET-NE showed prolonged drug release profile as compared to suspension. SE was induced by KA (10 mg/kg, i.p.) in Swiss albino mice. Behavioral seizure monitoring, biochemical estimations, and histopathological examination were performed. The onset time of SE was significantly enhanced and % incidence of SE was reduced by intranasal administration of LET-NE as compared to KA and LET administered intraperitoneally. Biochemical estimations revealed that LET-NE effectively decreased levels of 17-β estradiol while the levels of 5α-Dihydrotestosterone (5α-DHT) and 3α-androstanediol (3α-Diol) were significantly increased in the hippocampus. In cresyl violet staining LET-NE showed better protection of the hippocampus from neurotoxicity induced by KA as compared to LET. Also, in gamma scintigraphy of mouse brain, intranasal administration of nanoemulsion exhibited the presence of high concentration of LET. The study demonstrates the anticonvulsant and neuroprotective effect of LET-NE probably by inhibition of aromatization of testosterone into 17-β estradiol, proconvulsant, and diverting the pathway into the synthesis of testosterone metabolites, 3α-Diol with known anticonvulsant and neuroprotective action. Brain targeting of LET-NE showed better anticonvulsant and neuroprotective action than LET.
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Affiliation(s)
- Ramsha Iqbal
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Shakeeb Ahmed
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Gaurav K Jain
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Divya Vohora
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India.
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14
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Abraira L, Gramegna LL, Quintana M, Santamarina E, Salas-Puig J, Sarria S, Rovira A, Toledo M. Cerebrovascular disease burden in late-onset non-lesional focal epilepsy. Seizure 2019; 66:31-35. [DOI: 10.1016/j.seizure.2019.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 10/27/2022] Open
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15
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Abstract
The mammalian brain receives the lion’s share of the body’s blood supply and is a highly vascularized organ. The vascular and nervous systems arise at two distinct time points of embryogenesis; however, their functions tend to overlap or complement each other in the growth promoting milieu of the embryonic Central Nervous System (CNS). The pre-existing idea that mental disorders are a direct result from defects solely in neuronal populations and networks is gradually changing. Several studies have implicated blood vessel pathologies and blood flow changes in mental health disorders. Our own studies provide new perspectives as to how intrinsic defects in periventricular endothelial cells, from the earliest developmental time points can lead to the origin of mental health disorders such as schizophrenia, autism spectrum disorders (ASD), anxiety, and depression, thereby establishing direct links. In this article, we provide an overview of how the endothelial cell compartment in the brain is now gaining attention in the context of mental health disorders.
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Affiliation(s)
- Jugajyoti Baruah
- Department of Psychiatry, Harvard Medical School, Boston, MA-02215, USA.,Angiogenesis and Brain Development Laboratory, Division of Basic Neuroscience, McLean Hospital, 115 Mill Street, Belmont, MA-02478, USA
| | - Anju Vasudevan
- Department of Psychiatry, Harvard Medical School, Boston, MA-02215, USA.,Angiogenesis and Brain Development Laboratory, Division of Basic Neuroscience, McLean Hospital, 115 Mill Street, Belmont, MA-02478, USA
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16
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Gimenes AD, Andrade BFD, Pinotti JVP, Oliani SM, Galvis-Alonso OY, Gil CD. Annexin A1-derived peptide Ac 2-26 in a pilocarpine-induced status epilepticus model: anti-inflammatory and neuroprotective effects. J Neuroinflammation 2019; 16:32. [PMID: 30755225 PMCID: PMC6371492 DOI: 10.1186/s12974-019-1414-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Background The inflammatory process has been described as a crucial mechanism in the pathophysiology of temporal lobe epilepsy. The anti-inflammatory protein annexin A1 (ANXA1) represents an interesting target in the regulation of neuroinflammation through the inhibition of leukocyte transmigration and the release of proinflammatory mediators. In this study, the role of the ANXA1-derived peptide Ac2-26 in an experimental model of status epilepticus (SE) was evaluated. Methods Male Wistar rats were divided into Naive, Sham, SE and SE+Ac2-26 groups, and SE was induced by intrahippocampal injection of pilocarpine. In Sham animals, saline was applied into the hippocampus, and Naive rats were only handled. Three doses of Ac2-26 (1 mg/kg) were administered intraperitoneally (i.p.) after 2, 8 and 14 h of SE induction. Finally, 24 h after the experiment-onset, rats were euthanized for analyses of neuronal lesion and inflammation. Results Pilocarpine induced generalised SE in all animals, causing neuronal damage, and systemic treatment with Ac2-26 decreased neuronal degeneration and albumin levels in the hippocampus. Also, both SE groups showed an intense influx of microglia, which was corroborated by high levels of ionised calcium binding adaptor molecule 1(Iba-1) and monocyte chemoattractant protein-1 (MCP-1) in the hippocampus. Ac2-26 reduced the astrocyte marker (glial fibrillary acidic protein; GFAP) levels, as well as interleukin-1β (IL-1β), interleukin-6 (IL-6) and growth-regulated alpha protein (GRO/KC). These effects of the peptide were associated with the modulation of the levels of formyl peptide receptor 2, a G-protein-coupled receptor that binds to Ac2-26, and the phosphorylated extracellular signal-regulated kinase (ERK) in the hippocampal neurons. Conclusions The data suggest a neuroprotective effect of Ac2-26 in the epileptogenic processes through downregulation of inflammatory mediators and neuronal loss.
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Affiliation(s)
- Alexandre D Gimenes
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, SP, 04023-900, Brazil
| | - Bruna F D Andrade
- Department of Molecular Biology, São José do Rio Preto School of Medicine (FAMERP), São José do Rio Preto, SP, 15090-000, Brazil
| | - José Victor P Pinotti
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, SP, 04023-900, Brazil
| | - Sonia M Oliani
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, SP, 04023-900, Brazil.,From the Post-Graduation in Biosciences, Instituto de Biociências, Letras e Ciências Exatas, São Paulo State University (IBILCE/UNESP), São José do Rio Preto, SP, 15054-000, Brazil
| | - Orfa Y Galvis-Alonso
- Department of Molecular Biology, São José do Rio Preto School of Medicine (FAMERP), São José do Rio Preto, SP, 15090-000, Brazil
| | - Cristiane D Gil
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, SP, 04023-900, Brazil. .,From the Post-Graduation in Biosciences, Instituto de Biociências, Letras e Ciências Exatas, São Paulo State University (IBILCE/UNESP), São José do Rio Preto, SP, 15054-000, Brazil.
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17
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Jiang J, Yu Y, Kinjo ER, Du Y, Nguyen HP, Dingledine R. Suppressing pro-inflammatory prostaglandin signaling attenuates excitotoxicity-associated neuronal inflammation and injury. Neuropharmacology 2019; 149:149-160. [PMID: 30763657 DOI: 10.1016/j.neuropharm.2019.02.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/29/2019] [Accepted: 02/09/2019] [Indexed: 02/06/2023]
Abstract
Glutamate receptor-mediated excitotoxicity is a common pathogenic process in many neurological conditions including epilepsy. Prolonged seizures induce elevations in extracellular glutamate that contribute to excitotoxic damage, which in turn can trigger chronic neuroinflammatory reactions, leading to secondary damage to the brain. Blocking key inflammatory pathways could prevent such secondary brain injury following the initial excitotoxic insults. Prostaglandin E2 (PGE2) has emerged as an important mediator of neuroinflammation-associated injury, in large part via activating its EP2 receptor subtype. Herein, we investigated the effects of EP2 receptor inhibition on excitotoxicity-associated neuronal inflammation and injury in vivo. Utilizing a bioavailable and brain-permeant compound, TG6-10-1, we found that pharmacological inhibition of EP2 receptor after a one-hour episode of kainate-induced status epilepticus (SE) in mice reduced seizure-promoted functional deficits, cytokine induction, reactive gliosis, blood-brain barrier impairment, and hippocampal damage. Our preclinical findings endorse the feasibility of blocking PGE2/EP2 signaling as an adjunctive strategy to treat prolonged seizures. The promising benefits from EP2 receptor inhibition should also be relevant to other neurological conditions in which excitotoxicity-associated secondary damage to the brain represents a pathogenic event.
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Affiliation(s)
- Jianxiong Jiang
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA; Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.
| | - Ying Yu
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Erika Reime Kinjo
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Yifeng Du
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Hoang Phuong Nguyen
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ray Dingledine
- Department of Pharmacology and Chemical Biology, School of Medicine, Emory University, Atlanta, GA, USA
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18
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Lee WJ, Moon J, Jeon D, Kim TJ, Yoo JS, Park DK, Lee ST, Jung KH, Park KI, Jung KY, Kim M, Lee SK, Chu K. Possible epigenetic regulatory effect of dysregulated circular RNAs in epilepsy. PLoS One 2018; 13:e0209829. [PMID: 30592747 PMCID: PMC6310357 DOI: 10.1371/journal.pone.0209829] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 12/12/2018] [Indexed: 12/11/2022] Open
Abstract
Circular RNAs (circRNAs) involve in the epigenetic regulation and its major mechanism is the sequestration of the target micro RNAs (miRNAs). We hypothesized that circRNAs might be related with the pathophysiology of chronic epilepsy and evaluated the altered circRNA expressions and their possible regulatory effects on their target miRNAs and mRNAs in a mouse epilepsy model. The circRNA expression profile in the hippocampus of the pilocarpine mice was analyzed and compared with control. The correlation between the expression of miRNA binding sites (miRNA response elements, MRE) in the dysregulated circRNAs and the expression of their target miRNAs was evaluated. As miRNAs also inhibit their target mRNAs, circRNA–miRNA-mRNA regulatory network, comprised of dysregulated RNAs that targets one another were searched. For the identified networks, bioinformatics analyses were performed. As the result, Forty-three circRNAs were dysregulated in the hippocampus (up-regulated, 26; down-regulated, 17). The change in the expression of MRE in those circRNAs negatively correlated with the change in the relevant target miRNA expression (r = -0.461, P<0.001), supporting that circRNAs inhibit their target miRNA. 333 dysregulated circRNA–miRNA-mRNA networks were identified. Gene ontology and pathway analyses demonstrated that the up-regulated mRNAs in those networks were closely related to the major processes in epilepsy. Among them, STRING analysis identified 37 key mRNAs with abundant (≥4) interactions with other dysregulated target mRNAs. The dysregulation of the circRNAs which had multiple interactions with key mRNAs were validated by PCR. We concluded that dysregulated circRNAs might have a pathophysiologic role in chronic epilepsy by regulating multiple disease relevant mRNAs via circRNA−miRNA−mRNA interactions.
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Affiliation(s)
- Woo-Jin Lee
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Jangsup Moon
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Daejong Jeon
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - Tae-Joon Kim
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Jung-Suk Yoo
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - Dong-Kyu Park
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - Soon-Tae Lee
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Keun-Hwa Jung
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Kyung-Il Park
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
- Department of Neurology, Seoul National University Healthcare System Gangnam Center, Seoul, South Korea
| | - Ki-Young Jung
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Manho Kim
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
| | - Sang Kun Lee
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
- * E-mail: (KC); (SKL)
| | - Kon Chu
- Department of Neurology, Comprehensive Epilepsy Center, Laboratory for Neurotherapeutics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
- Program in Neuroscience, Neuroscience Research Institute of SNUMRC, College of Medicine, Seoul National University, Seoul, South Korea
- * E-mail: (KC); (SKL)
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Kuruba R, Wu X, Reddy DS. Benzodiazepine-refractory status epilepticus, neuroinflammation, and interneuron neurodegeneration after acute organophosphate intoxication. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2845-2858. [PMID: 29802961 PMCID: PMC6066461 DOI: 10.1016/j.bbadis.2018.05.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 04/30/2018] [Accepted: 05/22/2018] [Indexed: 12/19/2022]
Abstract
Nerve agents and some pesticides such as diisopropylfluorophosphate (DFP) cause neurotoxic manifestations that include seizures and status epilepticus (SE), which are potentially lethal and carry long-term neurological morbidity. Current antidotes for organophosphate (OP) intoxication include atropine, 2-PAM and diazepam (a benzodiazepine for treating seizures and SE). There is some evidence for partial or complete loss of diazepam anticonvulsant efficacy when given 30 min or later after exposure to an OP; this condition is known as refractory SE. Effective therapies for OP-induced SE are lacking and it is unclear why current therapies do not work. In this study, we investigated the time-dependent efficacy of diazepam in the nerve agent surrogate DFP model of OP intoxication on seizure suppression and neuroprotection in rats, following an early and late therapy. Diazepam (5 mg/kg, IM) controlled seizures when given 10 min after DFP exposure ("early"), but it was completely ineffective at 60 or 120 min ("late") after DFP. DFP-induced neuronal injury, neuroinflammation, and neurodegeneration of principal cells and GABAergic interneurons were significantly reduced by early but not late therapy. These findings demonstrate that diazepam failed to control seizures, SE and neuronal injury when given 60 min or later after DFP exposure, confirming the benzodiazepine-refractory SE and brain damage after OP intoxication. In addition, this study indicates that degeneration of inhibitory interneurons and inflammatory glial activation are potential mechanisms underlying these morbid outcomes of OP intoxication. Therefore, novel anticonvulsant and neuroprotectant antidotes, superior to benzodiazepines, are desperately needed for controlling nerve agent-induced SE and brain injury.
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Affiliation(s)
- Ramkumar Kuruba
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center, College of Medicine, Bryan, TX 77807, USA
| | - Xin Wu
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center, College of Medicine, Bryan, TX 77807, USA
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center, College of Medicine, Bryan, TX 77807, USA.
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A Hydroxypyrone-Based Inhibitor of Metalloproteinase-12 Displays Neuroprotective Properties in Both Status Epilepticus and Optic Nerve Crush Animal Models. Int J Mol Sci 2018; 19:ijms19082178. [PMID: 30044455 PMCID: PMC6121268 DOI: 10.3390/ijms19082178] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/19/2018] [Accepted: 07/23/2018] [Indexed: 12/18/2022] Open
Abstract
Recently, we showed that matrix metalloproteinase-12 (MMP-12) is highly expressed in microglia and myeloid infiltrates, which are presumably involved in blood–brain barrier (BBB) leakage and subsequent neuronal cell death that follows status epilepticus (SE). Here, we assessed the effects of a hydroxypyrone-based inhibitor selective for MMP-12 in the pilocarpine-induced SE rat model to determine hippocampal cell survival. In the hippocampus of rats treated with pilocarpine, intra-hippocampal injections of the MMP-12 inhibitor protected Cornu Ammonis 3 (CA3) and hilus of dentate gyrus neurons against cell death and limited the development of the ischemic-like lesion that typically develops in the CA3 stratum lacunosum-moleculare of the hippocampus. Furthermore, we showed that MMP-12 inhibition limited immunoglobulin G and albumin extravasation after SE, suggesting a reduction in BBB leakage. Finally, to rule out any possible involvement of seizure modulation in the neuroprotective effects of MMP-12 inhibition, neuroprotection was also observed in the retina of treated animals after optic nerve crush. Overall, these results support the hypothesis that MMP-12 inhibition can directly counteract neuronal cell death and that the specific hydroxypyrone-based inhibitor used in this study could be a potential therapeutic agent against neurological diseases/disorders characterized by an important inflammatory response and/or neuronal cell loss.
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21
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Aromatase inhibition by letrozole attenuates kainic acid-induced seizures but not neurotoxicity in mice. Epilepsy Res 2018; 143:60-69. [DOI: 10.1016/j.eplepsyres.2018.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/02/2018] [Accepted: 04/07/2018] [Indexed: 12/11/2022]
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22
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Tang C, Gu Y, Wang H, Wu H, Wang Y, Meng Y, Han Z, Gu Y, Ma W, Jiang Z, Song Y, Na M, Lu D, Lin Z. Targeting of microRNA-21-5p protects against seizure damage in a kainic acid-induced status epilepticus model via PTEN-mTOR. Epilepsy Res 2018; 144:34-42. [PMID: 29751355 DOI: 10.1016/j.eplepsyres.2018.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 04/29/2018] [Accepted: 05/03/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Studies have shown that microRNAs play a role in the development of epilepsy by regulating downstream target messenger (m)RNA. The present study aims to determine the changes associated with microRNA-21-5p (miR-21-5p) during epileptogenesis in a kainic acid rat model, and to assess whether the PTEN-mTOR pathway is a target of miR-21-5p. METHOD Reverse transcription polymerase chain reaction (RT-PCR) was used to examine the quantitative expressions of miR-21-5p and PTEN, and Western blotting was used to test the activity of mTOR in the acute, latent, and chronic stages of epileptogenesis. The antagomir of miR-21-5p was injected into the intracerebroventricular space using a microsyringe. Neuronal death and epilepsy discharge were assessed by Nissl staining and electroencephalography (EEG), respectively. The Morris water maze (MWM) was used to assess the cognitive impairment in rats after status epilepticus (SE). RESULTS Both miR-21-5p and mTOR were upregulated and PTEN was downregulated in rats during acute, latent, and chronic stages of epileptogenesis when compared with those of the control. After using antagomir miR-21-5p in vivo, miR-21-5p and mTOR decreased and the expression of PTEN increased compared with that in the SE model. The silencing of miR-21-5p diminished the number of abnormal spikes on EEG and decreased the number of neuron deletions on Nissl staining. The cognitive and memory impairment caused by epilepsy could also be improved after miR-21-5p knockdown in vivo. CONCLUSION The results of the present study demonstrate that PTEN-mTOR is the target of miR-21-5p in a kainic acid model of epilepsy. The knockout of miR-21-5p decreases the neuronal damage in stages of epileptogenesis. The miR-21-5p/PTEN/mTOR axis may be a potential target for preventing and treating seizures and epileptic damage.
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Affiliation(s)
- Chongyang Tang
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Yunhe Gu
- Department of Pathology, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Haiyang Wang
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Hongmei Wu
- Department of Pathology, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Yu Wang
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Yao Meng
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Zhibin Han
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Yifei Gu
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Wei Ma
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Zhenfeng Jiang
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Yuanyuan Song
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Meng Na
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Dunyue Lu
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
| | - Zhiguo Lin
- Department of Neurosurgery, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
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Shekh-Ahmad T, Eckel R, Dayalan Naidu S, Higgins M, Yamamoto M, Dinkova-Kostova AT, Kovac S, Abramov AY, Walker MC. KEAP1 inhibition is neuroprotective and suppresses the development of epilepsy. Brain 2018; 141:1390-1403. [PMID: 29538645 DOI: 10.1093/brain/awy071] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/19/2018] [Indexed: 02/11/2024] Open
Abstract
Hippocampal sclerosis is a common acquired disease that is a major cause of drug-resistant epilepsy. A mechanism that has been proposed to lead from brain insult to hippocampal sclerosis is the excessive generation of reactive oxygen species, and consequent mitochondrial failure. Here we use a novel strategy to increase endogenous antioxidant defences using RTA 408, which we show activates nuclear factor erythroid 2-related factor 2 (Nrf2, encoded by NFE2L2) through inhibition of kelch like ECH associated protein 1 (KEAP1) through its primary sensor C151. Activation of Nrf2 with RTA 408 inhibited reactive oxygen species production, mitochondrial depolarization and cell death in an in vitro model of seizure-like activity. RTA 408 given after status epilepticus in vivo increased ATP, prevented neuronal death, and dramatically reduced (by 94%) the frequency of late spontaneous seizures for at least 4 months following status epilepticus. Thus, acute KEAP1 inhibition following status epilepticus exerts a neuroprotective and disease-modifying effect, supporting the hypothesis that reactive oxygen species generation is a key event in the development of epilepsy.
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Affiliation(s)
- Tawfeeq Shekh-Ahmad
- UCL Institute of Neurology, University College London, Queen Square, London WC1N, UK
| | - Ramona Eckel
- UCL Institute of Neurology, University College London, Queen Square, London WC1N, UK
| | - Sharadha Dayalan Naidu
- Jacqui Wood Cancer Centre, Division of Cancer Research, School of Medicine, University of Dundee, Dundee, Scotland, UK
| | - Maureen Higgins
- Jacqui Wood Cancer Centre, Division of Cancer Research, School of Medicine, University of Dundee, Dundee, Scotland, UK
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan
| | - Albena T Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cancer Research, School of Medicine, University of Dundee, Dundee, Scotland, UK
- Department of Pharmacology and Molecular Sciences and Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Stjepana Kovac
- UCL Institute of Neurology, University College London, Queen Square, London WC1N, UK
- Department of Neurology, University of Muenster, Muenster 48149, Germany
| | - Andrey Y Abramov
- UCL Institute of Neurology, University College London, Queen Square, London WC1N, UK
| | - Matthew C Walker
- UCL Institute of Neurology, University College London, Queen Square, London WC1N, UK
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24
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Freitas MLD, Oliveira CVD, Mello FK, Funck VR, Fighera MR, Royes LFF, Furian AF, Larrick JW, Oliveira MS. Na +, K +-ATPase Activating Antibody Displays in vitro and in vivo Beneficial Effects in the Pilocarpine Model of Epilepsy. Neuroscience 2018. [PMID: 29522855 DOI: 10.1016/j.neuroscience.2018.02.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Na+, K+-ATPase is an important regulator of brain excitability. Accordingly, compelling evidence indicates that impairment of Na+, K+-ATPase activity contributes to seizure activity in epileptic mice and human with epilepsy. In addition, this enzyme is crucial for plasma membrane transport of water, glucose and several chemical mediators, including glutamate, the major excitatory transmitter in the mammalian brain. Since glucose hypometabolism and increased glutamate levels occur in clinical and experimental epilepsy, we aimed the present study to investigate whether activation of Na+, K+-ATPase activity with specific antibody (DRRSAb) would improve glucose uptake and glutamate release in pilocarpine-treated mice. We found decreased uptake of the glucose fluorescent analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-il)amino]-2-desoxi-d-glucose (2-NBDG) in cerebral slices from pilocarpine-treated animals. Interestingly, decreased 2-NBDG uptake was not detected in DRRSAb-treated slices, suggesting a protective effect of the Na+, K+-ATPase activator. Moreover, DRRSAb prevented the increase in glutamate levels in the incubation media of slices from pilocarpine-treated mice. In addition, in vivo intrahippocampal injection of DRRSAb restored crossing activity of pilocarpine-treated mice in the open-field test. Overall, the present data further support the hypothesis that activation of the Na+, K+-ATPase is a promising therapeutic strategy for epilepsy.
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Affiliation(s)
| | | | | | - Vinícius Rafael Funck
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michele Rechia Fighera
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Ana Flávia Furian
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - James W Larrick
- Panorama Research Institute, 1230 Bordeaux Dr, Sunnyvale, CA 94089, United States
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25
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Lucchi C, Costa AM, Giordano C, Curia G, Piat M, Leo G, Vinet J, Brunel L, Fehrentz JA, Martinez J, Torsello A, Biagini G. Involvement of PPARγ in the Anticonvulsant Activity of EP-80317, a Ghrelin Receptor Antagonist. Front Pharmacol 2017; 8:676. [PMID: 29018345 PMCID: PMC5614981 DOI: 10.3389/fphar.2017.00676] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/08/2017] [Indexed: 02/03/2023] Open
Abstract
Ghrelin, des-acyl ghrelin and other related peptides possess anticonvulsant activities. Although ghrelin and cognate peptides were shown to physiologically regulate only the ghrelin receptor, some of them were pharmacologically proved to activate the peroxisome proliferator-activated receptor gamma (PPARγ) through stimulation of the scavenger receptor CD36 in macrophages. In our study, we challenged the hypothesis that PPARγ could be involved in the anticonvulsant effects of EP-80317, a ghrelin receptor antagonist. For this purpose, we used the PPARγ antagonist GW9662 to evaluate the modulation of EP-80317 anticonvulsant properties in two different models. Firstly, the anticonvulsant effects of EP-80317 were studied in rats treated with pilocarpine to induce status epilepticus (SE). Secondly, the anticonvulsant activity of EP-80317 was ascertained in the repeated 6-Hz corneal stimulation model in mice. Behavioral and video electrocorticographic (ECoG) analyses were performed in both models. We also characterized levels of immunoreactivity for PPARγ in the hippocampus of 6-Hz corneally stimulated mice. EP-80317 predictably antagonized seizures in both models. Pretreatment with GW9662 counteracted almost all EP-80317 effects both in mice and rats. Only the effects of EP-80317 on power spectra of ECoGs recorded during repeated 6-Hz corneal stimulation were practically unaffected by GW9662 administration. Moreover, GW9662 alone produced a decrease in the latency of tonic-clonic seizures and accelerated the onset of SE in rats. Finally, in the hippocampus of mice treated with EP-80317 we found increased levels of PPARγ immunoreactivity. Overall, these results support the hypothesis that PPARγ is able to modulate seizures and mediates the anticonvulsant effects of EP-80317.
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Affiliation(s)
- Chiara Lucchi
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Anna M Costa
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Carmela Giordano
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Giulia Curia
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Marika Piat
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Giuseppina Leo
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Jonathan Vinet
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Luc Brunel
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Jean-Alain Fehrentz
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Jean Martinez
- Centre National de la Recherche Scientifique, Max Mousseron Institute of Biomolecules, National School of Chemistry Montpellier, University of MontpellierMontpellier, France
| | - Antonio Torsello
- School of Medicine and Surgery, University of Milano-BicoccaMilan, Italy
| | - Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy.,Center for Neuroscience and Neurotechnology, University of Modena and Reggio EmiliaModena, Italy
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26
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Gualtieri F, Brégère C, Laws GC, Armstrong EA, Wylie NJ, Moxham TT, Guzman R, Boswell T, Smulders TV. Effects of Environmental Enrichment on Doublecortin and BDNF Expression along the Dorso-Ventral Axis of the Dentate Gyrus. Front Neurosci 2017; 11:488. [PMID: 28966570 PMCID: PMC5605570 DOI: 10.3389/fnins.2017.00488] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/17/2017] [Indexed: 01/09/2023] Open
Abstract
Adult hippocampal neurogenesis (AHN) in the dentate gyrus is known to respond to environmental enrichment, chronic stress, and many other factors. The function of AHN may vary across the septo-temporal axis of the hippocampus, as different subdivisions are responsible for different functions. The dorsal pole regulates cognitive-related behaviors, while the ventral pole mediates mood-related responses through the hypothalamic-pituitary-adrenal (HPA) axis. In this study, we investigate different methods of quantifying the effect of environmental enrichment on AHN in the dorsal and ventral parts of the dentate gyrus (dDG and vDG). To this purpose, 11-week-old female CD-1 mice were assigned for 8 days to one of two conditions: the Environmental Enrichment (E) group received (i) running wheels, (ii) larger cages, (iii) plastic tunnels, and (iv) bedding with male urine, while the Control (C) group received standard housing. Dorsal CA (Cornu Ammonis) and DG regions were larger in the E than the C animals. Distance run linearly predicted the volume of the dorsal hippocampus, as well as of the intermediate and ventral CA regions. In the dDG, the amount of Doublecortin (DCX) immunoreactivity was significantly higher in E than in C mice. Surprisingly, this pattern was the opposite in the vDG (C > E). Real-time PCR measurement of Dcx mRNA and DCX protein analysis using ELISA showed the same pattern. Brain Derived Neurotrophic Factor (BDNF) immunoreactivity and mRNA displayed no difference between E and C, suggesting that upregulation of DCX was not caused by changes in BDNF levels. BDNF levels were higher in vDG than in dDG, as measured by both methods. Bdnf expression in vDG correlated positively with the distance run by individual E mice. The similarity in the patterns of immunoreactivity, mRNA and protein for differential DCX expression and for BDNF distribution suggests that the latter two methods might be effective tools for more rapid quantification of AHN.
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Affiliation(s)
- Fabio Gualtieri
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Catherine Brégère
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital BaselBasel, Switzerland
| | - Grace C Laws
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Elena A Armstrong
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom.,School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Nicholas J Wylie
- School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Theo T Moxham
- School of Psychology, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Raphael Guzman
- Brain Ischemia and Regeneration, Department of Biomedicine and Department of Neurosurgery, University Hospital BaselBasel, Switzerland
| | - Timothy Boswell
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom.,School of Natural and Environmental Sciences, Newcastle UniversityNewcastle upon Tyne, United Kingdom
| | - Tom V Smulders
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, United Kingdom
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27
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Keck M, Fournier A, Gualtieri F, Walker A, von Rüden EL, Russmann V, Deeg CA, Hauck SM, Krause R, Potschka H. A systems level analysis of epileptogenesis-associated proteome alterations. Neurobiol Dis 2017; 105:164-178. [PMID: 28576708 DOI: 10.1016/j.nbd.2017.05.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 05/22/2017] [Accepted: 05/29/2017] [Indexed: 12/18/2022] Open
Abstract
Despite intense research efforts, the knowledge about the mechanisms of epileptogenesis and epilepsy is still considered incomplete and limited. However, an in-depth understanding of molecular pathophysiological processes is crucial for the rational selection of innovative biomarkers and target candidates. Here, we subjected proteomic data from different phases of a chronic rat epileptogenesis model to a comprehensive systems level analysis. Weighted Gene Co-expression Network analysis identified several modules of interconnected protein groups reflecting distinct molecular aspects of epileptogenesis in the hippocampus and the parahippocampal cortex. Characterization of these modules did not only further validate the data but also revealed regulation of molecular processes not described previously in the context of epilepsy development. The data sets also provide valuable information about temporal patterns, which should be taken into account for development of preventive strategies in particular when it comes to multi-targeting network pharmacology approaches. In addition, principal component analysis suggests candidate biomarkers, which might inform the design of novel molecular imaging approaches aiming to predict epileptogenesis during different phases or confirm epilepsy manifestation. Further studies are necessary to distinguish between molecular alterations, which correlate with epileptogenesis versus those reflecting a mere consequence of the status epilepticus.
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Affiliation(s)
- Michael Keck
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany
| | - Anna Fournier
- Bioinformatics Core, Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 4367 Belvaux, Luxembourg
| | - Fabio Gualtieri
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany
| | - Andreas Walker
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany
| | - Eva-Lotta von Rüden
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany
| | - Vera Russmann
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany
| | - Cornelia A Deeg
- Institute of Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany; Experimental Ophthalmology, Philipps University of Marburg, 35037 Marburg, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Roland Krause
- Bioinformatics Core, Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 4367 Belvaux, Luxembourg.
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University (LMU), 80539 Munich, Germany.
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28
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Clossen BL, Reddy DS. Novel therapeutic approaches for disease-modification of epileptogenesis for curing epilepsy. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1519-1538. [PMID: 28179120 PMCID: PMC5474195 DOI: 10.1016/j.bbadis.2017.02.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 11/16/2022]
Abstract
This article describes the recent advances in epileptogenesis and novel therapeutic approaches for the prevention of epilepsy, with a special emphasis on the pharmacological basis of disease-modification of epileptogenesis for curing epilepsy. Here we assess animal studies and human clinical trials of epilepsy spanning 1982-2016. Epilepsy arises from a number of neuronal factors that trigger epileptogenesis, which is the process by which a brain shifts from a normal physiologic state to an epileptic condition. The events precipitating these changes can be of diverse origin, including traumatic brain injury, cerebrovascular damage, infections, chemical neurotoxicity, and emergency seizure conditions such as status epilepticus. Expectedly, the molecular and system mechanisms responsible for epileptogenesis are not well defined or understood. To date, there is no approved therapy for the prevention of epilepsy. Epigenetic dysregulation, neuroinflammation, and neurodegeneration appear to trigger epileptogenesis. Targeted drugs are being identified that can truly prevent the development of epilepsy in at-risk people. The promising agents include rapamycin, COX-2 inhibitors, TRK inhibitors, epigenetic modulators, JAK-STAT inhibitors, and neurosteroids. Recent evidence suggests that neurosteroids may play a role in modulating epileptogenesis. A number of promising drugs are under investigation for the prevention or modification of epileptogenesis to halt the development of epilepsy. Some drugs in development appear rational for preventing epilepsy because they target the initial trigger or related signaling pathways as the brain becomes progressively more prone to seizures. Additional research into the target validity and clinical investigation is essential to make new frontiers in curing epilepsy.
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Affiliation(s)
- Bryan L Clossen
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA.
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29
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Han H, Mann A, Ekstein D, Eyal S. Breaking Bad: the Structure and Function of the Blood-Brain Barrier in Epilepsy. AAPS JOURNAL 2017; 19:973-988. [DOI: 10.1208/s12248-017-0096-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 04/28/2017] [Indexed: 12/27/2022]
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30
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Soares JI, Valente MC, Andrade PA, Maia GH, Lukoyanov NV. Reorganization of the septohippocampal cholinergic fiber system in experimental epilepsy. J Comp Neurol 2017; 525:2690-2705. [PMID: 28472854 DOI: 10.1002/cne.24235] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 04/11/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022]
Abstract
The septohippocampal cholinergic neurotransmission has long been implicated in seizures, but little is known about the structural features of this projection system in epileptic brain. We evaluated the effects of experimental epilepsy on the areal density of cholinergic terminals (fiber varicosities) in the dentate gyrus. For this purpose, we used two distinct post-status epilepticus rat models, in which epilepsy was induced with injections of either kainic acid or pilocarpine. To visualize the cholinergic fibers, we used brain sections immunostained for the vesicular acetylcholine transporter. It was found that the density of cholinergic fiber varicosities was higher in epileptic rats versus control rats in the inner and outer zones of the dentate molecular layer, but it was reduced in the dentate hilus. We further evaluated the effects of kainate treatment on the total number, density, and soma volume of septal cholinergic cells, which were visualized in brain sections stained for either vesicular acetylcholine transporter or choline acetyltransferase (ChAT). Both the number of septal cells with cholinergic phenotype and their density were increased in epileptic rats when compared to control rats. The septal cells stained for vesicular acetylcholine transporter, but not for ChAT, have enlarged perikarya in epileptic rats. These results revealed previously unknown details of structural reorganization of the septohippocampal cholinergic system in experimental epilepsy, involving fiber sprouting into the dentate molecular layer and a parallel fiber retraction from the dentate hilus. We hypothesize that epilepsy-related neuroplasticity of septohippocampal cholinergic neurons is capable of increasing neuronal excitability of the dentate gyrus.
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Affiliation(s)
- Joana I Soares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.,Neuronal Networks Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal.,Departamento de Biologia Experimental, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Programa Doutoral em Neurociências, Universidade do Porto, Porto, Portugal
| | - Maria C Valente
- Departamento de Biologia Experimental, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Pedro A Andrade
- Programa Doutoral em Neurociências, Universidade do Porto, Porto, Portugal.,Department of Neurobiology, A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Gisela H Maia
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.,Neuronal Networks Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal.,Departamento de Biologia Experimental, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,Programa Doutoral em Neurociências, Universidade do Porto, Porto, Portugal
| | - Nikolai V Lukoyanov
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal.,Neuronal Networks Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal.,Departamento de Anatomia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal
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31
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Kim JE, Hyun HW, Min SJ, Kang TC. Sustained HSP25 Expression Induces Clasmatodendrosis via ER Stress in the Rat Hippocampus. Front Cell Neurosci 2017; 11:47. [PMID: 28275338 PMCID: PMC5319974 DOI: 10.3389/fncel.2017.00047] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 02/13/2017] [Indexed: 12/16/2022] Open
Abstract
Heat shock protein (HSP) 25 (murine/rodent 25 kDa, human 27 kDa) is one of the major astroglial HSP families, which has a potent anti-apoptotic factor contributing to a higher resistance of astrocytes to the stressful condition. However, impaired removals of HSP25 decrease astroglial viability. In the present study, we investigated whether HSP25 is involved in astroglial apoptosis or clasmatodendrosis (autophagic astroglial death) in the rat hippocampus induced by status epilepticus (SE). Following SE, HSP25 expression was transiently increased in astrocytes within the dentate gyrus (DG), while it was sustained in CA1 astrocytes until 4 weeks after SE. HSP25 knockdown exacerbated SE-induced apoptotic astroglial degeneration, but mitigated clasmatodendrosis accompanied by abrogation of endoplasmic reticulum (ER) stress without changed seizure susceptibility or severity. These findings suggest that sustained HSP25 induction itself may result in clasmatodendrosis via prolonged ER stress. To the best of our knowledge, the present study demonstrates for the first time the double-edge properties of HSP25 in astroglial death induced by SE.
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Affiliation(s)
- Ji-Eun Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Hye-Won Hyun
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Su-Ji Min
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Tae-Cheon Kang
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
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32
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Neurovascular unit remodelling in the subacute stage of stroke recovery. Neuroimage 2017; 146:869-882. [DOI: 10.1016/j.neuroimage.2016.09.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/31/2016] [Accepted: 09/08/2016] [Indexed: 01/19/2023] Open
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33
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Li F, Liu L. SIRT5 Deficiency Enhances Susceptibility to Kainate-Induced Seizures and Exacerbates Hippocampal Neurodegeneration not through Mitochondrial Antioxidant Enzyme SOD2. Front Cell Neurosci 2016; 10:171. [PMID: 27445698 PMCID: PMC4922023 DOI: 10.3389/fncel.2016.00171] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022] Open
Abstract
Epilepsy is a common and serious neurological disorder characterized by occurrence of recurrent spontaneous seizures, and emerging evidences support the association of mitochondrial dysfunction with epilepsy. Sirtuin 5 (SIRT5), localized in mitochondrial matrix, has been considered as an important functional modulator of mitochondria that contributes to ageing and neurological diseases. Our data shows that SIRT5 deficiency strikingly increased mortality rate and severity of response to epileptic seizures, dramatically exacerbated hippocampal neuronal loss and degeneration in mice exposed to Kainate (KA), and triggered more severe reactive astrogliosis. We found that the expression of mitochondrial SIRT5 of injured hippocampus was relatively up-regulated, indicating its potential contribution to the comparably increased survival of these cells and its possible neuroprotective role. Unexpectedly, SIRT5 seems not to apparently alter the decline of antioxidant enzymes superoxide dismutase 2 (SOD2) and glutathione peroxidase (GPx) in hippocampus caused by KA exposure in our paradigm, which indicates the protective role of SIRT5 on seizures and cellular degeneration might through different regulatory mechanism that would be explored in the future. In the present study, we provided strong evidences for the first time to demonstrate the association between SIRT5 and epilepsy, which offers a new understanding of the roles of SIRT5 in mitochondrial functional regulation. The neuroprotection of SIRT5 in KA-induced epileptic seizure and neurodegeneration will improve our current knowledge of the nature of SIRT5 in central nervous system (CNS) and neurological diseases.
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Affiliation(s)
- Fengling Li
- Department of Pharmacy, Linyi Tumor Hospital Linyi, Shandong, China
| | - Lei Liu
- Department of Anesthesiology, University of FloridaGainesville, FL, USA; Center for Translational Research in Neurodegenerative Disease, University of FloridaGainesville, FL, USA
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34
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Vinet J, Vainchtein ID, Spano C, Giordano C, Bordini D, Curia G, Dominici M, Boddeke HWGM, Eggen BJL, Biagini G. Microglia are less pro-inflammatory than myeloid infiltrates in the hippocampus of mice exposed to status epilepticus. Glia 2016; 64:1350-62. [DOI: 10.1002/glia.23008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/04/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences; University of Modena and Reggio Emilia; via G. Campi, 287 Modena Italy
| | - Ilia D. Vainchtein
- Department of Neuroscience; Section Medical Physiology, University Medical Center Groningen, University of Groningen; Antonius Deusinglaan, 1 Groningen The Netherlands
| | - Carlotta Spano
- Laboratory of Cell Therapies, Department of Medical and Surgical Sciences for Children & Adults; University Hospital of Modena and Reggio Emilia; via Del Pozzo, 71 Modena Italy
| | - Carmela Giordano
- Department of Biomedical, Metabolic and Neural Sciences; University of Modena and Reggio Emilia; via G. Campi, 287 Modena Italy
| | - Domenico Bordini
- Department of Biomedical, Metabolic and Neural Sciences; University of Modena and Reggio Emilia; via G. Campi, 287 Modena Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences; University of Modena and Reggio Emilia; via G. Campi, 287 Modena Italy
| | - Massimo Dominici
- Laboratory of Cell Therapies, Department of Medical and Surgical Sciences for Children & Adults; University Hospital of Modena and Reggio Emilia; via Del Pozzo, 71 Modena Italy
| | - Hendrikus W. G. M. Boddeke
- Department of Neuroscience; Section Medical Physiology, University Medical Center Groningen, University of Groningen; Antonius Deusinglaan, 1 Groningen The Netherlands
| | - Bart J. L. Eggen
- Department of Neuroscience; Section Medical Physiology, University Medical Center Groningen, University of Groningen; Antonius Deusinglaan, 1 Groningen The Netherlands
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences; University of Modena and Reggio Emilia; via G. Campi, 287 Modena Italy
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35
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Ko AR, Hyun HW, Min SJ, Kim JE. The Differential DRP1 Phosphorylation and Mitochondrial Dynamics in the Regional Specific Astroglial Death Induced by Status Epilepticus. Front Cell Neurosci 2016; 10:124. [PMID: 27242436 PMCID: PMC4870264 DOI: 10.3389/fncel.2016.00124] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/29/2016] [Indexed: 11/13/2022] Open
Abstract
The response and susceptibility to astroglial degenerations are relevant to the distinctive properties of astrocytes in a hemodynamic-independent manner following status epilepticus (SE). Since impaired mitochondrial fission plays an important role in mitosis, apoptosis and programmed necrosis, we investigated whether the unique pattern of mitochondrial dynamics is involved in the characteristics of astroglial death induced by SE. In the present study, SE induced astroglial apoptosis in the molecular layer of the dentate gyrus, accompanied by decreased mitochondrial length. In contrast, clasmatodendritic (autophagic) astrocytes in the CA1 region showed mitochondrial elongation induced by SE. Mdivi-1 (an inhibitor of mitochondrial fission) effectively attenuated astroglial apoptosis, but WY14643 (an enhancer of mitochondrial fission) aggravated it. In addition, Mdivi-1 accelerated clasmatodendritic changes in astrocytes. These regional specific mitochondrial dynamics in astrocytes were closely correlated with dynamin-related protein 1 (DRP1; a mitochondrial fission protein) phosphorylation, not optic atrophy 1 (OPA1; a mitochondrial fusion protein) expression. To the best of our knowledge, the present data demonstrate for the first time the novel role of DRP1-mediated mitochondrial fission in astroglial loss. Thus, the present findings suggest that the differential astroglial mitochondrial dynamics may participate in the distinct characteristics of astroglial death induced by SE.
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Affiliation(s)
- Ah-Reum Ko
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Hye-Won Hyun
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Su-Ji Min
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
| | - Ji-Eun Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University Chuncheon, South Korea
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Giordano C, Vinet J, Curia G, Biagini G. Repeated 6-Hz Corneal Stimulation Progressively Increases FosB/ΔFosB Levels in the Lateral Amygdala and Induces Seizure Generalization to the Hippocampus. PLoS One 2015; 10:e0141221. [PMID: 26555229 PMCID: PMC4640822 DOI: 10.1371/journal.pone.0141221] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 10/06/2015] [Indexed: 11/30/2022] Open
Abstract
Exposure to repetitive seizures is known to promote convulsions which depend on specific patterns of network activity. We aimed at evaluating the changes in seizure phenotype and neuronal network activation caused by a modified 6-Hz corneal stimulation model of psychomotor seizures. Mice received up to 4 sessions of 6-Hz corneal stimulation with fixed current amplitude of 32 mA and inter-stimulation interval of 72 h. Video-electroencephalography showed that evoked seizures were characterized by a motor component and a non-motor component. Seizures always appeared in frontal cortex, but only at the fourth stimulation they involved the hippocampus, suggesting the establishment of an epileptogenic process. Duration of seizure non-motor component progressively decreased after the second session, whereas convulsive seizures remained unchanged. In addition, a more severe seizure phenotype, consisting of tonic-clonic generalized convulsions, was predominant after the second session. Immunohistochemistry and double immunofluorescence experiments revealed a significant increase in neuronal activity occurring in the lateral amygdala after the fourth session, most likely due to activity of principal cells. These findings indicate a predominant role of amygdala in promoting progressively more severe convulsions as well as the late recruitment of the hippocampus in the seizure spread. We propose that the repeated 6-Hz corneal stimulation model may be used to investigate some mechanisms of epileptogenesis and to test putative antiepileptogenic drugs.
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MESH Headings
- Animals
- Basolateral Nuclear Complex/metabolism
- Basolateral Nuclear Complex/physiopathology
- Cornea/physiopathology
- Disease Models, Animal
- Electric Stimulation/adverse effects
- Electrodes, Implanted
- Electroencephalography
- Epilepsy, Complex Partial/etiology
- Epilepsy, Complex Partial/genetics
- Epilepsy, Complex Partial/physiopathology
- Epilepsy, Generalized/etiology
- Epilepsy, Generalized/genetics
- Epilepsy, Generalized/physiopathology
- Epilepsy, Tonic-Clonic/etiology
- Epilepsy, Tonic-Clonic/genetics
- Epilepsy, Tonic-Clonic/physiopathology
- Gene Expression Regulation
- Hippocampus/physiopathology
- Male
- Mice
- Microglia/pathology
- Nerve Net/physiopathology
- Nerve Tissue Proteins/biosynthesis
- Nerve Tissue Proteins/genetics
- Neurons/metabolism
- Neurons/pathology
- Phenotype
- Proto-Oncogene Proteins c-fos/biosynthesis
- Proto-Oncogene Proteins c-fos/genetics
- Severity of Illness Index
- Single-Blind Method
- Video Recording
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Affiliation(s)
- Carmela Giordano
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neurosciences, NOCSAE Hospital, AUSL Modena, Italy
- * E-mail:
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Ko AR, Hyun HW, Min SJ, Kim JE, Kang TC. Endothelin-1 induces LIMK2-mediated programmed necrotic neuronal death independent of NOS activity. Mol Brain 2015; 8:58. [PMID: 26438559 PMCID: PMC4595180 DOI: 10.1186/s13041-015-0149-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/18/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Recently, we have reported that LIM kinase 2 (LIMK2) involves programmed necrotic neuronal deaths induced by aberrant cyclin D1 expression following status epilepticus (SE). Up-regulation of LIMK2 expression induces neuronal necrosis by impairment of dynamin-related protein 1 (DRP1)-mediated mitochondrial fission. However, we could not elucidate the upstream effecter for LIMK2-mediated neuronal death. Thus, we investigated the role of endothelin-1 (ET-1) in LIMK2-mediated neuronal necrosis, since ET-1 involves neuronal death via various pathways. RESULTS Following SE, ET-1 concentration and its mRNA were significantly increased in the hippocampus with up-regulation of ETB receptor expression. BQ788 (an ETB receptor antagonist) effectively attenuated SE-induced neuronal damage as well as reduction in LIMK2 mRNA/protein expression. In addition, BQ788 alleviated up-regulation of Rho kinase 1 (ROCK1) expression and impairment of DRP1-mediated mitochondrial fission in CA1 neurons following SE. BQ788 also attenuated neuronal death and up-regulation of LIMK2 expression induced by exogenous ET-1 injection. CONCLUSION These findings suggest that ET-1 may be one of the upstream effectors for programmed neuronal necrosis through abnormal LIMK2 over-expression by ROCK1.
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Affiliation(s)
- Ah-Reum Ko
- Department of Anatomy & Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea
| | - Hye-Won Hyun
- Department of Anatomy & Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea
| | - Su-Ji Min
- Department of Anatomy & Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea
| | - Ji-Eun Kim
- Department of Anatomy & Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea.
| | - Tae-Cheon Kang
- Department of Anatomy & Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea.
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38
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Van Nieuwenhuyse B, Raedt R, Sprengers M, Dauwe I, Gadeyne S, Carrette E, Delbeke J, Wadman WJ, Boon P, Vonck K. The systemic kainic acid rat model of temporal lobe epilepsy: Long-term EEG monitoring. Brain Res 2015; 1627:1-11. [PMID: 26381287 DOI: 10.1016/j.brainres.2015.08.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 08/10/2015] [Accepted: 08/12/2015] [Indexed: 02/03/2023]
Abstract
Animal models reproducing the characteristics of human epilepsy are essential for the elucidation of the pathophysiological mechanisms. In epilepsy research there is ongoing debate on whether the epileptogenic process is a continuous process rather than a step function. The aim of this study was to assess progression of epileptogenesis over the long term and to evaluate possible correlations between SE duration and severity with the disease progression in the kainic acid model. Rats received repeated KA injections (5mg/kg) until a self-sustained SE was elicited. Continuous depth EEG recording started before KA injection and continued for 30 weeks. Mean seizure rate progression could be expressed as a sigmoid function and increased from 1 ± 0.2 seizures per day during the second week after SE to 24.4 ± 6.4 seizures per day during week 30. Seizure rate progressed to a plateau phase 122 ± 9 days after SE. However, the individual seizure rate during this plateau phase varied between 14.5 seizures and 48.6 seizures per day. A circadian rhythm in seizure occurrence was observed in all rats. Histological characterization of damage to the dentate gyrus in the KA treated rats confirmed the presence of astrogliosis and aberrant mossy fiber sprouting in the dentate gyrus. This long-term EEG monitoring study confirms that epileptogenesis is a continuous process rather than a step function.
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Affiliation(s)
- B Van Nieuwenhuyse
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - R Raedt
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - M Sprengers
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - I Dauwe
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - S Gadeyne
- Swammerdam Institute of Life Sciences, University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
| | - E Carrette
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium
| | - J Delbeke
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - W J Wadman
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium; Swammerdam Institute of Life Sciences, University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
| | - P Boon
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
| | - K Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology, and Neuropsychology, Department of Neurology, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium.
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Lucchi C, Vinet J, Meletti S, Biagini G. Ischemic-hypoxic mechanisms leading to hippocampal dysfunction as a consequence of status epilepticus. Epilepsy Behav 2015; 49:47-54. [PMID: 25934585 DOI: 10.1016/j.yebeh.2015.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
Abstract
Status epilepticus (SE) is one of the recognized primary precipitating events that can lead to temporal lobe epilepsy (TLE) associated with hippocampal sclerosis. This type of epilepsy is characterized by poor response to drug treatment, often requiring surgical intervention to remove the mesial temporal regions involved in the seizure onset. However, even neurosurgery may not be completely successful. Thus, the prevention of hippocampal damage and epileptogenesis is currently evaluated as a possible alternative therapeutic approach to prevent the development of pharmacoresistant TLE. Lines of evidence suggest that ischemic-hypoxic lesions might occur in different brain regions, including the hippocampus, during SE. Especially in the hippocampal CA3 region, an ischemic-like lesion develops in the stratum lacunosum-moleculare and is mainly characterized by a loss of astrocytes and neuronal processes and increased immunostaining of pimonidazole which probes areas exposed to hypoxia. Interestingly, these mechanisms can contribute to neuronal cell loss and may be counteracted by drugs that can afford vascular protection, as in the case of ligands of the ghrelin receptor. Notably, some of the ghrelin receptor ligands possess a double edge effect, since they are anticonvulsant and vascular-protective, thus, potentially representing new tools to counteract the consequences of SE. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Chiara Lucchi
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Stefano Meletti
- Department of Biomedical, Metabolic and Neural Sciences, Neurology Unit, University of Modena and Reggio Emilia, Modena, Italy
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSL Modena, Modena, Italy.
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40
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Gasparini S, Ferlazzo E, Beghi E, Sofia V, Mumoli L, Labate A, Cianci V, Fatuzzo D, Bellavia MA, Arcudi L, Russo E, De Sarro G, Gambardella A, Aguglia U. Epilepsy associated with Leukoaraiosis mainly affects temporal lobe: a casual or causal relationship? Epilepsy Res 2015; 109:1-8. [DOI: 10.1016/j.eplepsyres.2014.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/14/2014] [Accepted: 10/18/2014] [Indexed: 10/24/2022]
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41
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Kim YJ, Kim JY, Ko AR, Kang TC. Over-expression of laminin correlates to recovery of vasogenic edema following status epilepticus. Neuroscience 2014; 275:146-61. [DOI: 10.1016/j.neuroscience.2014.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 11/29/2022]
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42
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Curia G, Lucchi C, Vinet J, Gualtieri F, Marinelli C, Torsello A, Costantino L, Biagini G. Pathophysiogenesis of mesial temporal lobe epilepsy: is prevention of damage antiepileptogenic? Curr Med Chem 2014; 21:663-88. [PMID: 24251566 PMCID: PMC4101766 DOI: 10.2174/0929867320666131119152201] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/04/2013] [Accepted: 08/29/2013] [Indexed: 12/26/2022]
Abstract
Temporal lobe epilepsy (TLE) is frequently associated with hippocampal sclerosis, possibly caused by a primary brain injury that occurred a long time before the appearance of neurological symptoms. This type of epilepsy is characterized by refractoriness to drug treatment, so to require surgical resection of mesial temporal regions involved in seizure onset. Even this last therapeutic approach may fail in giving relief to patients. Although prevention of hippocampal damage and epileptogenesis after a primary event could be a key innovative approach to TLE, the lack of clear data on the pathophysiological mechanisms leading to TLE does not allow any rational therapy. Here we address the current knowledge on mechanisms supposed to be involved in epileptogenesis, as well as on the possible innovative treatments that may lead to a preventive approach. Besides loss of principal neurons and of specific interneurons, network rearrangement caused by axonal sprouting and neurogenesis are well known phenomena that are integrated by changes in receptor and channel functioning and modifications in other cellular components. In particular, a growing body of evidence from the study of animal models suggests that disruption of vascular and astrocytic components of the blood-brain barrier takes place in injured brain regions such as the hippocampus and piriform cortex. These events may be counteracted by drugs able to prevent damage to the vascular component, as in the case of the growth hormone secretagogue ghrelin and its analogues. A thoroughly investigation on these new pharmacological tools may lead to design effective preventive therapies.
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Affiliation(s)
| | | | | | | | | | | | | | - G Biagini
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Laboratorio di Epilettologia Sperimentale, Universita di Modena e Reggio Emilia, Via Campi, 287, 41125 Modena, Italy.
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43
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Rossi AR, Angelo MF, Villarreal A, Lukin J, Ramos AJ. Gabapentin administration reduces reactive gliosis and neurodegeneration after pilocarpine-induced status epilepticus. PLoS One 2013; 8:e78516. [PMID: 24250797 PMCID: PMC3826740 DOI: 10.1371/journal.pone.0078516] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 09/18/2013] [Indexed: 01/22/2023] Open
Abstract
The lithium-pilocarpine model of epilepsy reproduces in rodents several features of human temporal lobe epilepsy, by inducing an acute status epilepticus (SE) followed by a latency period. It has been proposed that the neuronal network reorganization that occurs during latency determines the subsequent appearance of spontaneous recurrent seizures. The aim of this study was to evaluate neuronal and glial responses during the latency period that follows SE. Given the potential role of astrocytes in the post-SE network reorganization, through the secretion of synaptogenic molecules such as thrombospondins, we also studied the effect of treatment with the α2δ1 thrombospondin receptor antagonist gabapentin. Adult male Wistar rats received 3 mEq/kg LiCl, and 20 h later 30 mg/kg pilocarpine. Once SE was achieved, seizures were stopped with 20 mg/kg diazepam. Animals then received 400 mg/kg/day gabapentin or saline for either 4 or 14 days. In vitro experiments were performed in dissociated mixed hippocampal cell culture exposed to glutamate, and subsequently treated with gabapentin or vehicle. During the latency period, the hippocampus and pyriform cortex of SE-animals presented a profuse reactive astrogliosis, with increased GFAP and nestin expression. Gliosis intensity was dependent on the Racine stage attained by the animals and peaked 15 days after SE. Microglia was also reactive after SE, and followed the same pattern. Neuronal degeneration was present in SE-animals, and also depended on the Racine stage and the SE duration. Polysialic-acid NCAM (PSA-NCAM) expression was increased in hippocampal CA-1 and dentate gyrus of SE-animals. Gabapentin treatment was able to reduce reactive gliosis, decrease neuronal loss and normalize PSA-NCAM staining in hippocampal CA-1. In vitro, gabapentin treatment partially prevented the dendritic loss and reactive gliosis caused by glutamate excitotoxicity. Our results show that gabapentin treatment during the latency period after SE protects neurons and normalizes PSA-NCAM probably by direct interaction with neurons and glia.
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Affiliation(s)
- Alicia Raquel Rossi
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Maria Florencia Angelo
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Alejandro Villarreal
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Jerónimo Lukin
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Alberto Javier Ramos
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- * E-mail:
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44
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Biagini G, Rustichelli C, Curia G, Vinet J, Lucchi C, Pugnaghi M, Meletti S. Neurosteroids and epileptogenesis. J Neuroendocrinol 2013; 25:980-90. [PMID: 23763517 DOI: 10.1111/jne.12063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/21/2013] [Accepted: 06/09/2013] [Indexed: 12/22/2022]
Abstract
Epileptogenesis is defined as the latent period at the end of which spontaneous recurrent seizures occur. This concept has been recently re-evaluated to include exacerbation of clinically-manifested epilepsy. Thus, in patients affected by pharmacoresistant seizures, the progression toward a worse condition may be viewed as the result of a durable epileptogenic process. However, the mechanism potentially responsible for this progression remains unclear. Neuroinflammation has been consistently detected both in the latent period and in the chronic phase of epilepsy, especially when brain damage is present. This phenomenon is accompanied by glial cell reaction, leading to gliosis. We have previously described rats presenting an increased expression of the cytochrome P450 cholesterol side-chain cleavage (P450scc) enzyme, during the latent period, in glial cells of the hippocampus. The P450scc enzyme is critically involved in the synthesis of neurosteroids and its up-regulation is associated with a delayed appearance of spontaneous recurrent seizures in rats that experienced status epilepticus induced by pilocarpine. Moreover, by decreasing the synthesis of neurosteroids able to promote inhibition, such as allopregnanolone, through the administration of the 5α-reductase blocker finasteride, it is possible to terminate the latent period in pilocarpine-treated rats. Finasteride was also found to promote seizures in the chronic period of epileptic rats, suggesting that neurosteroids are continuously produced to counteract seizures. In humans, exacerbation of epilepsy has been also described in patients occasionally exposed to finasteride. Overall, these findings suggest a major role of neurosteroids in the progression of epilepsy and a possible antiepileptogenic role of allopregnanolone and cognate molecules.
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Affiliation(s)
- G Biagini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
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45
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Biagini G, D'Antuono M, Benini R, de Guzman P, Longo D, Avoli M. Perirhinal cortex and temporal lobe epilepsy. Front Cell Neurosci 2013; 7:130. [PMID: 24009554 PMCID: PMC3756799 DOI: 10.3389/fncel.2013.00130] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/01/2013] [Indexed: 12/30/2022] Open
Abstract
The perirhinal cortex—which is interconnected with several limbic structures and is intimately involved in learning and memory—plays major roles in pathological processes such as the kindling phenomenon of epileptogenesis and the spread of limbic seizures. Both features may be relevant to the pathophysiology of mesial temporal lobe epilepsy that represents the most refractory adult form of epilepsy with up to 30% of patients not achieving adequate seizure control. Compared to other limbic structures such as the hippocampus or the entorhinal cortex, the perirhinal area remains understudied and, in particular, detailed information on its dysfunctional characteristics remains scarce; this lack of information may be due to the fact that the perirhinal cortex is not grossly damaged in mesial temporal lobe epilepsy and in models mimicking this epileptic disorder. However, we have recently identified in pilocarpine-treated epileptic rats the presence of selective losses of interneuron subtypes along with increased synaptic excitability. In this review we: (i) highlight the fundamental electrophysiological properties of perirhinal cortex neurons; (ii) briefly stress the mechanisms underlying epileptiform synchronization in perirhinal cortex networks following epileptogenic pharmacological manipulations; and (iii) focus on the changes in neuronal excitability and cytoarchitecture of the perirhinal cortex occurring in the pilocarpine model of mesial temporal lobe epilepsy. Overall, these data indicate that perirhinal cortex networks are hyperexcitable in an animal model of temporal lobe epilepsy, and that this condition is associated with a selective cellular damage that is characterized by an age-dependent sensitivity of interneurons to precipitating injuries, such as status epilepticus.
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Affiliation(s)
- Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Modena, Italy
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46
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Lucchi C, Curia G, Vinet J, Gualtieri F, Bresciani E, Locatelli V, Torsello A, Biagini G. Protective but not anticonvulsant effects of ghrelin and JMV-1843 in the pilocarpine model of Status epilepticus. PLoS One 2013; 8:e72716. [PMID: 24015271 PMCID: PMC3755992 DOI: 10.1371/journal.pone.0072716] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 07/15/2013] [Indexed: 12/25/2022] Open
Abstract
In models of status epilepticus ghrelin displays neuroprotective effects mediated by the growth hormone secretagogue-receptor 1a (GHS-R1a). This activity may be explained by anticonvulsant properties that, however, are controversial. We further investigated neuroprotection and the effects on seizures by comparing ghrelin with a more effective GHS-R1a agonist, JMV-1843. Rats were treated either with ghrelin, JMV-1843 or saline 10 min before pilocarpine, which was used to induce status epilepticus. Status epilepticus, developed in all rats, was attenuated by diazepam. No differences were observed among the various groups in the characteristics of pilocarpine-induced seizures. In saline group the area of lesion, characterized by lack of glial fibrillary acidic protein immunoreactivity, was of 0.45±0.07 mm2 in the hippocampal stratum lacunosum-moleculare, and was accompanied by upregulation of laminin immunostaining, and by increased endothelin-1 expression. Both ghrelin (P<0.05) and JMV-1843 (P<0.01) were able to reduce the area of loss in glial fibrillary acidic protein immunostaining. In addition, JMV-1843 counteracted (P<0.05) the changes in laminin and endothelin-1 expression, both increased in ghrelin-treated rats. JMV-1843 was able to ameliorate neuronal survival in the hilus of dentate gyrus and medial entorhinal cortex layer III (P<0.05 vs saline and ghrelin groups). These results demonstrate diverse protective effects of growth hormone secretagogues in rats exposed to status epilepticus.
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Affiliation(s)
- Chiara Lucchi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Fabio Gualtieri
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elena Bresciani
- Department of Health Sciences, University of Milano-Bicocca, Monza, Italy
| | - Vittorio Locatelli
- Department of Health Sciences, University of Milano-Bicocca, Monza, Italy
| | - Antonio Torsello
- Department of Health Sciences, University of Milano-Bicocca, Monza, Italy
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neurosciences, NOCSAE Hospital, Modena, Italy
- * E-mail:
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47
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Hypoxia markers are expressed in interneurons exposed to recurrent seizures. Neuromolecular Med 2012; 15:133-46. [PMID: 23073716 DOI: 10.1007/s12017-012-8203-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
An early but transient decrease in oxygen availability occurs during experimentally induced seizures. Using pimonidazole, which probes hypoxic insults, we found that by increasing the duration of pilocarpine-induced status epilepticus (SE) from 30 to 120 min, counts of pimonidazole-immunoreactive neurons also increased (P < 0.01, 120 vs 60 and 30 min). All the animals exposed to SE were immunopositive to pimonidazole, but a different scenario emerged during epileptogenesis when a decrease in pimonidazole-immunostained cells occurred from 7 to 14 days, so that only 1 out of 4 rats presented with pimonidazole-immunopositive cells. Pimonidazole-immunoreactive cells robustly reappeared at 21 days post-SE induction when all animals (7 out of 7) had developed spontaneous recurrent seizures. Specific neuronal markers revealed that immunopositivity to pimonidazole was present in cells identified by neuropeptide Y (NPY) or somatostatin antibodies. At variance, neurons immunopositive to parvalbumin or cholecystokinin were not immunopositive to pimonidazole. Pimonidazole-immunopositive neurons expressed remarkable immunoreactivity to hypoxia-inducible factor 1α (HIF-1α). Interestingly, surgical samples obtained from pharmacoresistant patients showed neurons co-labeled by HIF-1α and NPY antibodies. These interneurons, along with parvalbumin-positive interneurons that were negative to HIF-1α, showed immunopositivity to markers of cell damage, such as high-mobility group box 1 in the cytoplasm and cleaved caspase-3 in the nucleus. These findings suggest that interneurons are continuously endangered in rodent and human epileptogenic tissue. The presence of hypoxia and cell damage markers in NPY interneurons of rats and patients presenting with recurrent seizures indicates a mechanism of selective vulnerability in a specific neuronal subpopulation.
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