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Kim JE, Lee DS, Wang SH, Kim TH, Kang TC. GPx1-ERK1/2-CREB pathway regulates the distinct vulnerability of hippocampal neurons to oxidative stress via modulating mitochondrial dynamics following status epilepticus. Neuropharmacology 2024; 260:110135. [PMID: 39214451 DOI: 10.1016/j.neuropharm.2024.110135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 08/18/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
Glutathione peroxidase-1 (GPx1) and cAMP/Ca2+ responsive element (CRE)-binding protein (CREB) regulate neuronal viability by maintaining the redox homeostasis. Since GPx1 and CREB reciprocally regulate each other, it is likely that GPx1-CREB interaction may play a neuroprotective role against oxidative stress, which are largely unknown. Thus, we investigated the underlying mechanisms of the reciprocal regulation between GPx1 and CREB in the male rat hippocampus. Under physiological condition, L-buthionine sulfoximine (BSO)-induced oxidative stress increased GPx1 expression, extracellular signal-regulated kinase 1/2 (ERK1/2) activity and CREB serine (S) 133 phosphorylation in CA1 neurons, but not dentate granule cells (DGC), which were diminished by GPx1 siRNA, U0126 or CREB knockdown. GPx1 knockdown inhibited ERK1/2 and CREB activations induced by BSO. CREB knockdown also decreased the efficacy of BSO on ERK1/2 activation. BSO facilitated dynamin-related protein 1 (DRP1)-mediated mitochondrial fission in CA1 neurons, which abrogated by GPx1 knockdown and U0126. CREB knockdown blunted BSO-induced DRP1 upregulation without affecting DRP1 S616 phosphorylation ratio. Following status epilepticus (SE), GPx1 expression was reduced in CA1 neurons and DGC. SE also decreased CREB activity CA1 neurons, but not DGC. SE degenerated CA1 neurons, but not DGC, accompanied by mitochondrial elongation. These post-SE events were ameliorated by N-acetylcysteine (NAC, an antioxidant), but deteriorated by GPx1 knockdown. These findings indicate that a transient GPx1-ERK1/2-CREB activation may be a defense mechanism to protect hippocampal neurons against oxidative stress via maintenance of proper mitochondrial dynamics.
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Affiliation(s)
- Ji-Eun Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, 24252, South Korea.
| | - Duk-Shin Lee
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, 24252, South Korea.
| | - Su Hyeon Wang
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, 24252, South Korea
| | - Tae-Hyun Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, 24252, South Korea
| | - Tae-Cheon Kang
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chuncheon, 24252, South Korea.
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Smith RA, Mir F, Butler MP, Maharathi B, Loeb JA. Spike-induced cytoarchitectonic changes in epileptic human cortex are reduced via MAP2K inhibition. Brain Commun 2024; 6:fcae152. [PMID: 38741662 PMCID: PMC11089420 DOI: 10.1093/braincomms/fcae152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/01/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
Interictal spikes are electroencephalographic discharges that occur at or near brain regions that produce epileptic seizures. While their role in generating seizures is not well understood, spikes have profound effects on cognition and behaviour, depending on where and when they occur. We previously demonstrated that spiking areas of human neocortex show sustained MAPK activation in superficial cortical Layers I-III and are associated with microlesions in deeper cortical areas characterized by reduced neuronal nuclear protein staining and increased microglial infiltration. Based on these findings, we chose to investigate additional neuronal populations within microlesions, specifically inhibitory interneurons. Additionally, we hypothesized that spiking would be sufficient to induce similar cytoarchitectonic changes within the rat cortex and that inhibition of MAPK signalling, using a MAP2K inhibitor, would not only inhibit spike formation but also reduce these cytoarchitectonic changes and improve behavioural outcomes. To test these hypotheses, we analysed tissue samples from 16 patients with intractable epilepsy who required cortical resections. We also utilized a tetanus toxin-induced animal model of interictal spiking, designed to produce spikes without seizures in male Sprague-Dawley rats. Rats were fitted with epidural electrodes, to permit EEG recording for the duration of the study, and automated algorithms were implemented to quantify spikes. After 6 months, animals were sacrificed to assess the effects of chronic spiking on cortical cytoarchitecture. Here, we show that microlesions may promote excitability due to a significant reduction of inhibitory neurons that could be responsible for promoting interictal spikes in superficial layers. Similarly, we found that the induction of epileptic spikes in the rat model produced analogous changes, including reduced neuronal nuclear protein, calbindin and parvalbumin-positive neurons and increased microglia, suggesting that spikes are sufficient for inducing these cytoarchitectonic changes in humans. Finally, we implicated MAPK signalling as a driving force producing these pathological changes. Using CI-1040 to inhibit MAP2K, both acutely and after spikes developed, resulting in fewer interictal spikes, reduced microglial activation and less inhibitory neuron loss. Treated animals had significantly fewer high-amplitude, short-duration spikes, which correlated with improved spatial memory performance on the Barnes maze. Together, our results provide evidence for a cytoarchitectonic pathogenesis underlying epileptic cortex, which can be ameliorated through both early and delayed MAP2K inhibition. These findings highlight the potential role for CI-1040 as a pharmacological treatment that could prevent the development of epileptic activity and reduce cognitive impairment in both patients with epilepsy and those with non-epileptic spike-associated neurobehavioural disorders.
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Affiliation(s)
- Rachael A Smith
- Department of Neurology and Rehabilitation, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Fozia Mir
- Department of Neurology and Rehabilitation, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Mitchell P Butler
- Department of Neurology and Rehabilitation, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Biswajit Maharathi
- Department of Neurology and Rehabilitation, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Jeffrey A Loeb
- Department of Neurology and Rehabilitation, University of Illinois Chicago, Chicago, IL 60612, USA
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Wu N, Liu H, Lv X, Sun Y, Jiang H. Neobaicalein prevents isoflurane anesthesia-induced cognitive impairment in neonatal mice via regulating CREB1. Clinics (Sao Paulo) 2023; 78:100201. [PMID: 37120983 PMCID: PMC10173397 DOI: 10.1016/j.clinsp.2023.100201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/24/2023] [Accepted: 04/04/2023] [Indexed: 05/02/2023] Open
Abstract
OBJECTIVES Isoflurane (ISO) is widely used in the clinic and research. The authors aimed to explore whether Neobaicalein (Neob) could protect neonatal mice from ISO-induced cognitive damage. METHOD The open field test, Morris water maze test, and tail suspension test was performed to assess the cognitive function in mice. Enzyme-linked immunosorbent assay was used to evaluate inflammatory-related protein concentrations. Immunohistochemistry was used to assess Ionized calcium-Binding Adapter molecule-1 (IBA-1) expression. Hippocampal neuron viability was detected using the Cell Counting Kit-8 assay. Double immunofluorescence staining was employed to confirm the interaction between proteins. Western blotting was used to assess protein expression levels. RESULTS Neob notably improved cognitive function and exhibited anti-inflammatory effects; moreover, under iso-treatment, it exhibited neuroprotective effects. Furthermore, Neob suppressed interleukin-1β, tumor necrosis factor-α, and interleukin-6 levels and upregulated interleukin-10 levels in ISO-treated mice. Neob significantly mitigated iso-induced increases in IBA-1-positive cell numbers of the hippocampus in neonatal mice. Furthermore, it inhibited ISO-induced neuronal apoptosis. Mechanistically, Neob was observed to upregulate cAMP Response Element Binding protein (CREB1) phosphorylation and protected hippocampal neurons from ISO-mediated apoptosis. Moreover, it rescued ISO-induced abnormalities of synaptic protein. CONCLUSIONS Neob prevented ISO anesthesia-induced cognitive impairment by suppressing apoptosis and inflammation through upregulating CREB1.
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Affiliation(s)
- Niming Wu
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hua Liu
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiang Lv
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Sun
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Jiang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Whyte-Fagundes P, Taskina D, Safarian N, Zoidl C, Carlen PL, Donaldson LW, Zoidl GR. Panx1 channels promote both anti- and pro-seizure-like activities in the zebrafish via p2rx7 receptors and ATP signaling. Commun Biol 2022; 5:472. [PMID: 35585187 PMCID: PMC9117279 DOI: 10.1038/s42003-022-03356-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 04/12/2022] [Indexed: 11/08/2022] Open
Abstract
The molecular mechanisms of excitation/inhibition imbalances promoting seizure generation in epilepsy patients are not fully understood. Evidence suggests that Pannexin1 (Panx1), an ATP release channel, modulates the excitability of the brain. In this report, we performed electrophysiological, behavioral, and molecular phenotyping experiments on zebrafish larvae bearing genetic or pharmacological knockouts of Panx1a and Panx1b channels, each homologous to human PANX1. When Panx1a function is lost, or both channels are under pharmacological blockade, seizures with ictal-like events and seizure-like locomotion are reduced in the presence of pentylenetetrazol. Transcriptome profiling by RNA-seq demonstrates a spectrum of distinct metabolic and cell signaling states which correlate with the loss of Panx1a. Furthermore, the pro- and anticonvulsant activities of both Panx1 channels affect ATP release and involve the purinergic receptor P2rx7. Our findings suggest a subfunctionalization of Panx1 enabling dual roles in seizures, providing a unique and comprehensive perspective to understanding seizure mechanisms in the context of this channel.
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Affiliation(s)
- Paige Whyte-Fagundes
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada.
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada.
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada.
| | - Daria Taskina
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Nickie Safarian
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Christiane Zoidl
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Peter L Carlen
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada
- Department of Medicine, Physiology and BME, University of Toronto, 399 Bathurst St., 5w442, Toronto, ON, M5T 2S8, Canada
| | | | - Georg R Zoidl
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada.
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada.
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada.
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5
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Ammothumkandy A, Ravina K, Wolseley V, Tartt AN, Yu PN, Corona L, Zhang N, Nune G, Kalayjian L, Mann JJ, Rosoklija GB, Arango V, Dwork AJ, Lee B, Smith JAD, Song D, Berger TW, Heck C, Chow RH, Boldrini M, Liu CY, Russin JJ, Bonaguidi MA. Altered adult neurogenesis and gliogenesis in patients with mesial temporal lobe epilepsy. Nat Neurosci 2022; 25:493-503. [PMID: 35383330 PMCID: PMC9097543 DOI: 10.1038/s41593-022-01044-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/01/2022] [Indexed: 01/19/2023]
Abstract
The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.
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Affiliation(s)
- Aswathy Ammothumkandy
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kristine Ravina
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Victoria Wolseley
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alexandria N Tartt
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
| | - Pen-Ning Yu
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Luis Corona
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Naibo Zhang
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - George Nune
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Laura Kalayjian
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - J John Mann
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Gorazd B Rosoklija
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
- Macedonian Academy of Sciences and Arts, Skopje, Republic of Macedonia
| | - Victoria Arango
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Andrew J Dwork
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
- Macedonian Academy of Sciences and Arts, Skopje, Republic of Macedonia
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Brian Lee
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - J A D Smith
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Dong Song
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Theodore W Berger
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Christianne Heck
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Robert H Chow
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Maura Boldrini
- Division of Molecular Imaging and Neuropathology, NYS Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Charles Y Liu
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jonathan J Russin
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Michael A Bonaguidi
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA.
- Department of Gerontology, University of Southern California, Los Angeles, CA, USA.
- Department of Biochemistry and Molecular Medicine, University of Southern California, Los Angeles, CA, USA.
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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Martins-Ferreira R, Leal B, Chaves J, Li T, Ciudad L, Rangel R, Santos A, Martins da Silva A, Pinho Costa P, Ballestar E. Epilepsy progression is associated with cumulative DNA methylation changes in inflammatory genes. Prog Neurobiol 2022; 209:102207. [DOI: 10.1016/j.pneurobio.2021.102207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/02/2021] [Accepted: 12/14/2021] [Indexed: 01/09/2023]
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Mumtaz F, Rashki A, Imran Khan M, Shadboorestan A, Abdollahi A, Ghazi-Khansari M, Alotaibi G, Dehpour AR. Neuroprotective effect of sumatriptan in pentylenetetrazole-induced seizure is mediated through N-methyl-D-aspartate/nitric oxide and cAMP response element-binding protein signaling pathway. Fundam Clin Pharmacol 2021; 36:250-261. [PMID: 34545607 DOI: 10.1111/fcp.12728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/29/2021] [Accepted: 09/17/2021] [Indexed: 12/12/2022]
Abstract
Seizure occurs as a result of uncontrolled electrical disturbances within the brain. Various biomolecules such as N-methyl-D-aspartate (NMDA), nitric oxide (NO), and cAMP response element-binding protein (CREB) have been implicated in the pathophysiology of seizure. Sumatriptan is a specific 5-Hydroxytryptamine 1B/1D receptor agonist and has neuroprotective effects in various neuropsychiatric disorders. In the current study, we tried to investigate the possible interaction of sumatriptan with NMDA/NO and CREB signaling pathway in PTZ induced seizure. For this purpose, various agonist and antagonist of NMDA such as MK-801 and Ketamine, NO precursor L-ARG, and NOS inhibitors L-NAME and 7-NI were co-administered with sumatriptan in PTZ induced seizure model. The level of nitrite in mice hippocampus was determined by Griess reaction. The gene expression of NR1, NR2A, NR2B, and CREB were quantified by quantitative real time-polymerase chain reaction (qRT-PCR). Furthermore, the involved neuronal nitric oxide synthase (nNOS) protein expression was examined via western blot analysis. Effective dose of sumatriptan (1.2 mg/kg) alone and subeffective dose of sumatriptan (0.3 mg/kg) in combination with NMDA and/or NO antagonist showed significant (P < 0.001) anticonvulsant activity in mice. Furthermore, sumatriptan significantly inhibited the PTZ-induced mRNA expression of NR2A (P < 0.0001), NR2B (P < 0.05), and CREB (P < 0.01). Also, the expression of nNOS protein in PTZ treated group was reversed by sumatriptan (P < 0.01). Hence, current findings suggest that the anticonvulsant effect of sumatriptan was due to down regulation of NMDA/NO and CREB signaling pathway.
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Affiliation(s)
- Faiza Mumtaz
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,International Campus of Tehran University of Medical Sciences, Tehran, Iran
| | - Asma Rashki
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Muhammad Imran Khan
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Riphah International University, Islamabad, Pakistan
| | - Amir Shadboorestan
- Department of Toxicology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Alireza Abdollahi
- Department of Pathology, Imam Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Ghazi-Khansari
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghallab Alotaibi
- Department of Pharmaceutical Sciences, College of Pharmacy, Al-Dawadmi Campus, Shaqra University, Shaqra, Kingdom of Saudi Arabia
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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8
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Paudel YN, Khan SU, Othman I, Shaikh MF. Naturally Occurring HMGB1 Inhibitor, Glycyrrhizin, Modulates Chronic Seizures-Induced Memory Dysfunction in Zebrafish Model. ACS Chem Neurosci 2021; 12:3288-3302. [PMID: 34463468 DOI: 10.1021/acschemneuro.0c00825] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Glycyrrhizin (GL) is a well-known pharmacological inhibitor of high mobility group box 1 (HMGB1) and is abundantly present in the licorice root (Glycyrrhiza radix). HMGB1 protein, a key mediator of neuroinflammation, has been implicated in several neurological disorders, including epilepsy. Epilepsy is a devastating neurological disorder with no effective disease-modifying treatment strategies yet, suggesting a pressing need for exploring novel therapeutic options. In the current investigation, using a second hit pentylenetetrazol (PTZ) induced chronic seizure model in adult zebrafish, regulated mRNA expression of HMGB1 was inhibited by pretreatment with GL (25, 50, and 100 mg/kg, ip). A molecular docking study suggests that GL establishes different binding interactions with the various amino acid chains of HMGB1 and Toll-like receptor-4 (TLR4). Our finding suggests that GL pretreatment reduces/suppresses second hit PTZ induced seizure, as shown by the reduction in the seizure score. GL also regulates the second hit PTZ induced behavioral impairment and rescued second hit PTZ related memory impairment as demonstrated by an increase in the inflection ratio (IR) at the 3 h and 24 h T-maze trial. GL inhibited seizure-induced neuronal activity as demonstrated by reduced C-fos mRNA expression. GL also modulated mRNA expression of BDNF, CREB-1, and NPY. The possible mechanism underlying the anticonvulsive effect of GL could be attributed to its anti-inflammatory activity, as demonstrated by the downregulated mRNA expression level of HMGB1, TLR4, NF-kB, and TNF-α. Overall, our finding suggests that GL exerts an anticonvulsive effect and ameliorates seizure-related memory disruption plausibly through regulating of the HMGB1-TLR4-NF-kB axis.
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Affiliation(s)
- Yam Nath Paudel
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Selangor, Malaysia
| | - Shafi Ullah Khan
- School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Subang Jaya 47500, Selangor, Malaysia
- Department of Pharmacy, Abasyn University, Ring Road, Peshawar 25120, Pakistan
| | - Iekhsan Othman
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Selangor, Malaysia
- Liquid Chromatography-Mass Spectrometry (LCMS) Platform, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Selangor, Malaysia
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9
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Schlabitz S, Monni L, Ragot A, Dipper-Wawra M, Onken J, Holtkamp M, Fidzinski P. Spatiotemporal Correlation of Epileptiform Activity and Gene Expression in vitro. Front Mol Neurosci 2021; 14:643763. [PMID: 33859552 PMCID: PMC8042243 DOI: 10.3389/fnmol.2021.643763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022] Open
Abstract
Epileptiform activity alters gene expression in the central nervous system, a phenomenon that has been studied extensively in animal models. Here, we asked whether also in vitro models of seizures are in principle suitable to investigate changes in gene expression due to epileptiform activity and tested this hypothesis mainly in rodent and additionally in some human brain slices. We focused on three genes relevant for seizures and epilepsy: FOS proto-oncogene (c-Fos), inducible cAMP early repressor (Icer) and mammalian target of rapamycin (mTor). Seizure-like events (SLEs) were induced by 4-aminopyridine (4-AP) in rat entorhinal-hippocampal slices and by 4-AP/8 mM potassium in human temporal lobe slices obtained from surgical treatment of epilepsy. SLEs were monitored simultaneously by extracellular field potentials and intrinsic optical signals (IOS) for 1–4 h, mRNA expression was quantified by real time PCR. In rat slices, both duration of SLE exposure and SLE onset region were associated with increased expression of c-Fos and Icer while no such association was shown for mTor expression. Similar to rat slices, c-FOS induction in human tissue was increased in slices with epileptiform activity. Our results indicate that irrespective of limitations imposed by ex vivo conditions, in vitro models represent a suitable tool to investigate gene expression. Our finding is of relevance for the investigation of human tissue that can only be performed ex vivo. Specifically, it presents an important prerequisite for future studies on transcriptome-wide and cell-specific changes in human tissue with the goal to reveal novel candidates involved in the pathophysiology of epilepsy and possibly other CNS pathologies.
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Affiliation(s)
- Sophie Schlabitz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Laura Monni
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Alienor Ragot
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Matthias Dipper-Wawra
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Julia Onken
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurosurgery, Berlin, Germany
| | - Martin Holtkamp
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany
| | - Pawel Fidzinski
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, Neuroscience Research Center, Berlin, Germany
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10
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Kumari S, Sharma P, Mazumder AG, Rana AK, Sharma S, Singh D. Development and validation of chemical kindling in adult zebrafish: A simple and improved chronic model for screening of antiepileptic agents. J Neurosci Methods 2020; 346:108916. [PMID: 32818549 DOI: 10.1016/j.jneumeth.2020.108916] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 07/21/2020] [Accepted: 08/13/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Zebrafish has emerged as a potential animal model of acute convulsion for early screening of antiepileptic agents. There is a need for alternative chronic zebrafish models of epilepsy with more correlation to the clinical condition. NEW METHOD Adult zebrafish were repeatedly exposed to subeffective concentrations of pentylenetetrazole (PTZ), until appearance to tonic-clonic seizures, considered as kindled. Valproic acid (VPA) exposure was given during kindling and in kindled fish in 2 different groups. The neurotransmitters level and expression of the genes associated with kindling were studied in the fish brain. RESULTS There was an increase in seizure severity score at 1.25 mM concentration of PTZ, and 66.66 % of fish achieved kindling after 22 days' exposure. A marked increase in c-fos, crebbpa and crebbpbexpression, and glutamate/GABA level was observed in the brain of kindled fish. VPA inhibited the induction of PTZ-mediated kindling and reduced seizure severity in kindled fish. COMPARISON WITH EXISTING METHOD In contrast to an existing adult zebrafish kindling method, the present protocol is of longer duration, with more similarity to clinical epilepsy. Moreover, the induction of kindling involves a simple non-invasive technique without the use of anesthesia. The protocol can be used for evaluation of both antiepileptic and antiepileptogenic agents. CONCLUSION Repeated exposure of 1.25 mM PTZ induced kindling in zebrafish, altering the brain neurotransmitter levels and gene expression. Inhibition of kindling induction and decrease in seizures in normal and kindled fish, respectively by VPA validated application of the model for preclinical testing of agents against epilepsy.
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Affiliation(s)
- Savita Kumari
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India
| | - Pallavi Sharma
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India
| | - Arindam Ghosh Mazumder
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India
| | - Anil Kumar Rana
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India
| | - Supriya Sharma
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India
| | - Damanpreet Singh
- Pharmacology and Toxicology Laboratory, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, Himachal Pradesh, India.
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11
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Lee C, Jeong W, Chung CK. Clinical Relevance of Interictal Spikes in Tumor-Related Epilepsy: An Electrocorticographic Study. J Epilepsy Res 2020; 9:126-133. [PMID: 32509548 PMCID: PMC7251339 DOI: 10.14581/jer.19015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 09/21/2019] [Accepted: 01/31/2020] [Indexed: 11/16/2022] Open
Abstract
Background and Purpose Although some surgeons utilize interictal spikes recorded via electrocorticography (ECoG) when planning extensive peritumoral resection in patients with tumor-related epilepsy, the association between interictal spikes and epileptogenesis has not been fully described. We investigated whether the resection of interictal spikes recorded by ECoG is associated with more favorable surgical outcomes in tumor-related epilepsy. Methods Of 132 patients who underwent epilepsy surgery for tumor-related epilepsy from 2006 to 2013, seven patients who underwent extraoperative ECoG were included in this study. In each patient, ECoG interictal spike sources were localized using standardized low-resolution brain electromagnetic tomography and were co-registered into a reconstructed brain model. Correspondence to the resection volume was estimated by calculating the percentage of interictal spike sources in the resection volume. Results All patients achieved gross total resection without oncological recurrence. Five patients achieved favorable surgical outcomes, whereas the surgical outcomes of two patients were unfavorable. Correspondence rates to the resection volume in the favorable and unfavorable surgical outcome groups were 44.6%±27.8% and 43.5%±22.8%, respectively (p=0.96). All patients had interictal spike source clusters outside the resection volume regardless of seizure outcome. Conclusions In these cases of tumor-related epilepsy, the extent of the resection of ECoG interictal spikes was not associated with postoperative seizure outcomes. Furthermore, the presence of interictal spike sources outside of the resection area was not related to seizure outcomes. Instead, concentrating more on the complete removal of the brain tumor appears to be a rational approach.
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Affiliation(s)
- Changik Lee
- Department of Neurosurgery, Seoul St. Mary's Hospital, Seoul, Korea
| | - Woorim Jeong
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.,Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Science, Seoul, Korea
| | - Chun Kee Chung
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.,Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Science, Seoul, Korea.,Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Korea
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12
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De Santis D, Rossini L, Tassi L, Didato G, Tringali G, Cossu M, Bramerio M, Padelli F, Regondi MC, Colciaghi F, Aronica E, Spreafico R, Garbelli R. pCREB expression in human tissues from epilepsy surgery. Epilepsia 2020; 61:1240-1252. [PMID: 32463128 DOI: 10.1111/epi.16549] [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: 12/10/2019] [Accepted: 04/29/2020] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Activity-dependent changes have been reported in animal models and in human epileptic specimens and could potentially be used as tissue biomarkers to evaluate the propensity of a tissue to generate seizure activity. In this context, cAMP-response element binding protein (CREB) activation was specifically reported in human epileptic foci and related mainly to interictal spike activity. To get further insights into CREB activation in human epilepsy, we analyzed pCREB expression on brain tissue samples from patients who underwent surgery for drug-resistant focal epilepsy, correlating this expression with intracranial stereo-electroencephalography (SEEG) recording in a subgroup. METHODS Neocortical specimens from patients with neuropathological diagnosis of no lesion (cryptogenic), malformations of cortical development,mainly type II focal cortical dysplasia (FCD), and hippocampi with and without hippocampal sclerosis have been analyzed by immunohistochemistry. Peritumoral cortex from non-epileptic patients and autoptic samples were used as controls, whereas rat brains were used to test possible loss of pCREB antigenicity due to fixation procedures and postmortem delay. RESULTS pCREB was consistently expressed in layer II neuronal nuclei in regions with normal cortical lamination both in epileptic and non-epileptic surgical tissues. In patients with SEEG recordings, this anatomical pattern was unrelated to the presence of interictal spike activity. Conversely, in the core of type II FCD, as well as in other developmental malformations, pCREB was scattered without any laminar specificity. Furthermore, quantitative data did not reveal significant differences between epileptic and non-epileptic tissues, except for an increased immunoreactivity in the core of type IIB FCD lesion related mainly to reactive glial and balloon cells. SIGNIFICANCE The present data argue against the reliability of pCREB immunohistochemistry as a marker of epileptic focus but underscores its layer-related expression, suggesting a potential application in the study of malformations of cortical development, a wide range of diseases arising from perturbations of normal brain development.
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Affiliation(s)
- Dalia De Santis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Rossini
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Tassi
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy
| | - Giuseppe Didato
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Giovanni Tringali
- Neurosurgery Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Massimo Cossu
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy
| | | | - Francesco Padelli
- Scientific Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | - Francesca Colciaghi
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eleonora Aronica
- Department of (Neuro) Pathology, University of Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Zwolle, The Netherlands
| | - Roberto Spreafico
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rita Garbelli
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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13
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Effects of Huazhuo Jiedu Shugan Decoction on Cognitive and Emotional Disorders in a Rat Model of Epilepsy: Possible Involvement of AC-cAMP-CREB Signaling and NPY Expression. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:4352879. [PMID: 31915447 PMCID: PMC6930777 DOI: 10.1155/2019/4352879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/29/2019] [Accepted: 10/21/2019] [Indexed: 12/14/2022]
Abstract
Background Huazhuo Jiedu Shugan decoction (HJSD), a traditional Chinese medicine (TCM), has been used to treat epileptic seizures for many years. Some ingredients in these herbs have been demonstrated to be effective for the treatment of brain damage caused by epilepsy. Aim of the Study The object of the study is to determine the effects of HJSD on cognitive and emotional disorders in a rat model of epilepsy. Materials and Methods After a predetermined time period, rats were intraperitoneally injected with pentylenetetrazol and observed in different phases of convulsions. The cognitive and emotional changes in the epileptic rats were assessed using behavioral and immunohistochemical tests. Results Compared with the epilepsy group, the seizure grade was reduced and seizure latency was prolonged following HJSD-H treatment (P < 0.01). Compared with the control group, the epilepsy group displayed marked worse performance on the animal behavior tests (P < 0.05) and the HJSD-H group displayed improved behavioral performance (P < 0.05). After HJSD-H treatment, the expression of adenylate cyclase (AC), cyclic adenosine monophosphate (cAMP), cAMP-response element binding protein (CREB), and neuropeptide Y (NPY) immunoreactive cells markedly increased in the hippocampus, compared with that of the epilepsy group (P < 0.05). Conclusions The current results demonstrate that HJSD treatment in epileptic rats markedly inhibits epileptic seizures and improves cognitive and emotional disorders, which may be related to the regulation of AC-cAMP-CREB signaling and NPY expression in the hippocampus. The effects of the HJSD treatment may provide a foundation for the use of HJSD as a prescription medicinal herb in the TCM for the treatment of epilepsy.
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14
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Kirchner A, Dachet F, Loeb JA. Identifying targets for preventing epilepsy using systems biology of the human brain. Neuropharmacology 2019; 168:107757. [PMID: 31493467 DOI: 10.1016/j.neuropharm.2019.107757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 12/13/2022]
Abstract
Approximately one third of all epilepsy patients are resistant to current therapeutic treatments. Some patients with focal forms of epilepsy benefit from invasive surgical approaches that can lead to large surgical resections of human epileptic neocortex. We have developed a systems biology approach to take full advantage of these resections and the brain tissues they generate as a means to understand underlying mechanisms of neocortical epilepsy and to identify novel biomarkers and therapeutic targets. In this review, we will describe our unique approach that has led to the development of a 'NeuroRepository' of electrically-mapped epileptic tissues and associated data. This 'Big Data' approach links quantitative measures of ictal and interictal activities corresponding to a specific intracranial electrode to clinical, imaging, histological, genomic, proteomic, and metabolomic measures. This highly characterized data and tissue bank has given us an extraordinary opportunity to explore the underlying electrical, cellular, and molecular mechanisms of the human epileptic brain. We describe specific examples of how an experimental design that compares multiple cortical regions with different electrical activities has led to discoveries of layer-specific pathways and how these can be 'reverse translated' from animal models back to humans in the form of new biomarkers and therapeutic targets. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Allison Kirchner
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Fabien Dachet
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA; University of Illinois Neuro Repository, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Jeffrey A Loeb
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, 60612, USA; University of Illinois Neuro Repository, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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15
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Mertz C, Krarup S, Jensen CD, Lindholm SEH, Kjær C, Pinborg LH, Bak LK. Aspects of cAMP Signaling in Epileptogenesis and Seizures and Its Potential as Drug Target. Neurochem Res 2019; 45:1247-1255. [PMID: 31414342 DOI: 10.1007/s11064-019-02853-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/30/2019] [Accepted: 08/03/2019] [Indexed: 12/19/2022]
Abstract
Epilepsy is one of the most common chronic neurological conditions. Today, close to 30 different medications to prevent epileptic seizures are in use; yet, far from all patients become seizure free upon medical treatment. Thus, there is a need for new pharmacological approaches including novel drug targets for the management of epilepsy. Despite the fact that a role for cAMP signaling in epileptogenesis and seizures was first suggested some four decades ago, none of the current medications target the cAMP signaling system. The reasons for this are probably many including limited knowledge of the underlying biology and pathology as well as difficulties in designing selective drugs for the different components of the cAMP signaling system. This review explores selected aspects of cAMP signaling in the context of epileptogenesis and seizures including cAMP response element binding (CREB)-mediated transcriptional regulation. We discuss the therapeutic potential of targeting cAMP signaling in epilepsy and point to an increased knowledge of the A-kinase anchoring protein-based signaling hubs as being of seminal importance for future drug discovery within the field. Further, in terms of targeting CREB, we argue that targeting upstream cAMP signals might be more fruitful than targeting CREB itself. Finally, we point to astrocytes as cellular targets in epilepsy since cAMP signals may regulate astrocytic K+ clearance affecting neuronal excitability.
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Affiliation(s)
- Christoffer Mertz
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Sara Krarup
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Cecilie D Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Sandy E H Lindholm
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Christina Kjær
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark.,Department of Technology, Faculty of Health and Technology, University College Copenhagen, 2200, Copenhagen, Denmark
| | - Lars H Pinborg
- Epilepsy Clinic & Neurobiology Research Unit, Copenhagen University Hospital, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark.
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16
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Huyghe D, Denninger AR, Voss CM, Frank P, Gao N, Brandon N, Waagepetersen HS, Ferguson AD, Pangalos M, Doig P, Moss SJ. Phosphorylation of Glutamine Synthetase on Threonine 301 Contributes to Its Inactivation During Epilepsy. Front Mol Neurosci 2019; 12:120. [PMID: 31178690 PMCID: PMC6536897 DOI: 10.3389/fnmol.2019.00120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/25/2019] [Indexed: 12/16/2022] Open
Abstract
The astrocyte-specific enzyme glutamine synthetase (GS), which catalyzes the amidation of glutamate to glutamine, plays an essential role in supporting neurotransmission and in limiting NH4+ toxicity. Accordingly, deficits in GS activity contribute to epilepsy and neurodegeneration. Despite its central role in brain physiology, the mechanisms that regulate GS activity are poorly defined. Here, we demonstrate that GS is directly phosphorylated on threonine residue 301 (T301) within the enzyme’s active site by cAMP-dependent protein kinase (PKA). Phosphorylation of T301 leads to a dramatic decrease in glutamine synthesis. Enhanced T301 phosphorylation was evident in a mouse model of epilepsy, which may contribute to the decreased GS activity seen during this trauma. Thus, our results highlight a novel molecular mechanism that determines GS activity under both normal and pathological conditions.
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Affiliation(s)
- Deborah Huyghe
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Andrew R Denninger
- Mechanistic Biology & Profiling, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, MA, United States
| | - Caroline M Voss
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pernille Frank
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ning Gao
- Mechanistic Biology & Profiling, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, MA, United States
| | - Nicholas Brandon
- Neuroscience, IMED Biotech Unit, AstraZeneca, Boston, MA, United States.,AstraZeneca Tufts Laboratory for Basic and Translational Neuroscience, Boston, MA, United States
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andrew D Ferguson
- Structure & Biophysics, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, MA, United States
| | | | - Peter Doig
- Mechanistic Biology & Profiling, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, MA, United States
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States.,Department of Neuroscience, Physiology and Pharmacology, University College, London, United Kingdom
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17
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Inhibition of Acid Sensing Ion Channel 3 Aggravates Seizures by Regulating NMDAR Function. Neurochem Res 2018; 43:1227-1241. [DOI: 10.1007/s11064-018-2540-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/23/2018] [Accepted: 04/27/2018] [Indexed: 10/17/2022]
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18
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Keren-Aviram G, Dachet F, Bagla S, Balan K, Loeb JA, Dratz EA. Proteomic analysis of human epileptic neocortex predicts vascular and glial changes in epileptic regions. PLoS One 2018; 13:e0195639. [PMID: 29634780 PMCID: PMC5892923 DOI: 10.1371/journal.pone.0195639] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/26/2018] [Indexed: 01/21/2023] Open
Abstract
Epilepsy is a common neurological disorder, which is not well understood at the molecular level. Exactly why some brain regions produce epileptic discharges and others do not is not known. Patients who fail to respond to antiseizure medication (refractory epilepsy) can benefit from surgical removal of brain regions to reduce seizure frequency. The tissue removed in these surgeries offers an invaluable resource to uncover the molecular and cellular basis of human epilepsy. Here, we report a proteomic study to determine whether there are common proteomic patterns in human brain regions that produce epileptic discharges. We analyzed human brain samples, as part of the Systems Biology of Epilepsy Project (SBEP). These brain pieces are in vivo electrophysiologically characterized human brain samples withdrawn from the neocortex of six patients with refractory epilepsy. This study is unique in that for each of these six patients the comparison of protein expression was made within the same patient: a more epileptic region was compared to a less epileptic brain region. The amount of epileptic activity was defined for each patient as the frequency of their interictal spikes (electric activity between seizures that is a parameter strongly linked to epilepsy). Proteins were resolved from three subcellular fractions, using a 2D differential gel electrophoresis (2D-DIGE), revealing 31 identified protein spots that changed significantly. Interestingly, glial fibrillary acidic protein (GFAP) was found to be consistently down regulated in high spiking brain tissue and showed a strong negative correlation with spike frequency. We also developed a two-step analysis method to select for protein species that changed frequently among the patients and identified these proteins. A total of 397 protein spots of interest (SOI) were clustered by protein expression patterns across all samples. These clusters were used as markers and this analysis predicted proteomic changes due to both histological differences and molecular pathways, revealed by examination of gene ontology clusters. Our experimental design and proteomic data analysis predicts novel glial changes, increased angiogenesis, and changes in cytoskeleton and neuronal projections between high and low interictal spiking regions. Quantitative histological staining of these same tissues for both the vascular and glial changes confirmed these findings, which provide new insights into the structural and functional basis of neocortical epilepsy.
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Affiliation(s)
- Gal Keren-Aviram
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Fabien Dachet
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Shruti Bagla
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Karina Balan
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Jeffrey A. Loeb
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
| | - Edward A. Dratz
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, Montana, United States of America
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19
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Jarero-Basulto JJ, Gasca-Martínez Y, Rivera-Cervantes MC, Ureña-Guerrero ME, Feria-Velasco AI, Beas-Zarate C. Interactions Between Epilepsy and Plasticity. Pharmaceuticals (Basel) 2018; 11:ph11010017. [PMID: 29414852 PMCID: PMC5874713 DOI: 10.3390/ph11010017] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/01/2018] [Accepted: 02/06/2018] [Indexed: 02/06/2023] Open
Abstract
Undoubtedly, one of the most interesting topics in the field of neuroscience is the ability of the central nervous system to respond to different stimuli (normal or pathological) by modifying its structure and function, either transiently or permanently, by generating neural cells and new connections in a process known as neuroplasticity. According to the large amount of evidence reported in the literature, many stimuli, such as environmental pressures, changes in the internal dynamic steady state of the organism and even injuries or illnesses (e.g., epilepsy) may induce neuroplasticity. Epilepsy and neuroplasticity seem to be closely related, as the two processes could positively affect one another. Thus, in this review, we analysed some neuroplastic changes triggered in the hippocampus in response to seizure-induced neuronal damage and how these changes could lead to the establishment of temporal lobe epilepsy, the most common type of focal human epilepsy.
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Affiliation(s)
- José J Jarero-Basulto
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Yadira Gasca-Martínez
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Martha C Rivera-Cervantes
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Mónica E Ureña-Guerrero
- Neurotransmission Biology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Alfredo I Feria-Velasco
- Cellular Neurobiology Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
| | - Carlos Beas-Zarate
- Development and Neural Regeneration Laboratory, Cell and Molecular Biology Department, CUCBA, University of Guadalajara, 45220 Zapopan, Jalisco, Mexico.
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20
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Wu G, Yu J, Wang L, Ren S, Zhang Y. PKC/CREB pathway mediates the expressions of GABA A receptor subunits in cultured hippocampal neurons after low-Mg 2+ solution treatment. Epilepsy Res 2018; 140:155-161. [PMID: 29414524 DOI: 10.1016/j.eplepsyres.2017.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 10/08/2017] [Accepted: 11/16/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To investigate the potential effects of the PKC/CREB pathway on the expressions of GABAA receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg2+). METHODS A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg2+ solutions to generate a low Mg2+ model of epilepsy. The low Mg2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABAA receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABAA receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. RESULTS After the neurons were exposed to a low-Mg2+ solution for 3 h, GABAA receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABAA receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABAA subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. CONCLUSIONS The PKC/CREB pathway may negatively regulate the expressions of GABAA receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg2+ model of epilepsy.
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Affiliation(s)
- Guofeng Wu
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Jinpeng Yu
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Likun Wang
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Siying Ren
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Yixia Zhang
- Guizhou Centre for Disease Control and Prevention, Guiyang City, 550004, PR China
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21
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Liu J, Allender E, Wang J, Simpson EH, Loeb JA, Song F. Slowing disease progression in the SOD1 mouse model of ALS by blocking neuregulin-induced microglial activation. Neurobiol Dis 2017; 111:118-126. [PMID: 29278738 DOI: 10.1016/j.nbd.2017.12.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 11/05/2017] [Accepted: 12/19/2017] [Indexed: 12/13/2022] Open
Abstract
There are no effective treatments to slow disease progression in ALS. We previously reported that neuregulin (NRG) receptors are constitutively activated on microglia in the ventral horns in both ALS patients and SOD1 mice and in the corticospinal tracts of ALS patients, and that NRG receptor activation occurs prior to significant clinical disease onset in SOD1 mice. Here, we hypothesize that blocking NRG signaling on microglia would slow disease progression in SOD1 mice using a targeted NRG antagonist (HBD-S-H4). Recombinant HBD-S-H4 directly delivered into the central nervous system (CNS) through implanted intracerebroventricular cannulas showed no signs of toxicity and significantly inhibited NRG receptor activation on microglia resulting in reduced microglial activation and motor neuron loss. The treatment also resulted in a delay in disease onset and an increase in survival. The therapeutic effect was dose-dependent that varied as a function of genetic background in two different strains of SOD1 mice. As a complementary drug delivery approach, transgenic mice expressing HBD-S-H4 driven by an astrocytic promoter (GFAP) had slower disease progression in a dose dependent manner, based on the level of HBD-S-H4 expression. These studies provide mechanistic insights into how NRG signaling on microglia may lead to disease progression and demonstrate the utility of a humanized fusion protein that blocks NRG as a novel therapeutic for human ALS.
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Affiliation(s)
- Jianguo Liu
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, IL 60612, United States
| | - Elise Allender
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, IL 60612, United States
| | - Jiajing Wang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, United States
| | - Eleanor H Simpson
- Department of Psychiatry, Columbia University, New York, NY 10032, United States
| | - Jeffrey A Loeb
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, IL 60612, United States
| | - Fei Song
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, IL 60612, United States.
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22
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Lösing P, Niturad CE, Harrer M, Reckendorf CMZ, Schatz T, Sinske D, Lerche H, Maljevic S, Knöll B. SRF modulates seizure occurrence, activity induced gene transcription and hippocampal circuit reorganization in the mouse pilocarpine epilepsy model. Mol Brain 2017; 10:30. [PMID: 28716058 PMCID: PMC5513048 DOI: 10.1186/s13041-017-0310-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/28/2017] [Indexed: 11/10/2022] Open
Abstract
A hallmark of temporal lobe epilepsy (TLE) is hippocampal neuronal demise and aberrant mossy fiber sprouting. In addition, unrestrained neuronal activity in TLE patients induces gene expression including immediate early genes (IEGs) such as Fos and Egr1. We employed the mouse pilocarpine model to analyze the transcription factor (TF) serum response factor (SRF) in epileptogenesis, seizure induced histopathology and IEG induction. SRF is a neuronal activity regulated TF stimulating IEG expression as well as nerve fiber growth and guidance. Adult conditional SRF deficient mice (SrfCaMKCreERT2) were more refractory to initial status epilepticus (SE) acquisition. Further, SRF deficient mice developed more spontaneous recurrent seizures (SRS). Genome-wide transcriptomic analysis uncovered a requirement of SRF for SE and SRS induced IEG induction (e.g. Fos, Egr1, Arc, Npas4, Btg2, Atf3). SRF was required for epilepsy associated neurodegeneration, mossy fiber sprouting and inflammation. We uncovered MAP kinase signaling as SRF target during epilepsy. Upon SRF ablation, seizure evoked induction of dual specific phosphatases (Dusp5 and Dusp6) was reduced. Lower expression of these negative ERK kinase regulators correlated with altered P-ERK levels in epileptic Srf mutant animals. Overall, this study uncovered an SRF contribution to several processes of epileptogenesis in the pilocarpine model.
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Affiliation(s)
- Pascal Lösing
- Institute of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Cristina Elena Niturad
- Department of Neurology and Epileptology, Hertie-Institute of Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Merle Harrer
- Department of Neurology and Epileptology, Hertie-Institute of Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | | | - Theresa Schatz
- Institute of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Daniela Sinske
- Institute of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie-Institute of Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Snezana Maljevic
- Department of Neurology and Epileptology, Hertie-Institute of Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.,Present address: The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville VIC, Melbourne, 3052, Australia
| | - Bernd Knöll
- Institute of Physiological Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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23
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Wu HC, Dachet F, Ghoddoussi F, Bagla S, Fuerst D, Stanley JA, Galloway MP, Loeb JA. Altered metabolomic-genomic signature: A potential noninvasive biomarker of epilepsy. Epilepsia 2017; 58:1626-1636. [PMID: 28714074 DOI: 10.1111/epi.13848] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2017] [Indexed: 01/21/2023]
Abstract
OBJECTIVE This study aimed to identify noninvasive biomarkers of human epilepsy that can reliably detect and localize epileptic brain regions. Having noninvasive biomarkers would greatly enhance patient diagnosis, patient monitoring, and novel therapy development. At the present time, only surgically invasive, direct brain recordings are capable of detecting these regions with precision, which severely limits the pace and scope of both clinical management and research progress in epilepsy. METHODS We compared high versus low or nonspiking regions in nine medically intractable epilepsy surgery patients by performing integrated metabolomic-genomic-histological analyses of electrically mapped human cortical regions using high-resolution magic angle spinning proton magnetic resonance spectroscopy, cDNA microarrays, and histological analysis. RESULTS We found a highly consistent and predictive metabolite logistic regression model with reduced lactate and increased creatine plus phosphocreatine and choline, suggestive of a chronically altered metabolic state in epileptic brain regions. Linking gene expression, cellular, and histological differences to these key metabolites using a hierarchical clustering approach predicted altered metabolic vascular coupling in the affected regions. Consistently, these predictions were validated histologically, showing both neovascularization and newly discovered, millimeter-sized microlesions. SIGNIFICANCE Using a systems biology approach on electrically mapped human cortex provides new evidence for spatially segregated, metabolic derangements in both neurovascular and synaptic architecture in human epileptic brain regions that could be a noninvasively detectable biomarker of epilepsy. These findings both highlight the immense power of a systems biology approach and identify a potentially important role that magnetic resonance spectroscopy can play in the research and clinical management of epilepsy.
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Affiliation(s)
- Helen C Wu
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, Michigan, U.S.A
| | - Fabien Dachet
- Department of Neurology and Rehabilitation, University of Illinois, Chicago, Illinois, U.S.A
| | - Farhad Ghoddoussi
- Department of Anesthesiology and Neuroimaging Center, Wayne State University, Detroit, Michigan, U.S.A
| | - Shruti Bagla
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, U.S.A
| | - Darren Fuerst
- Department of Neurology and Rehabilitation, University of Illinois, Chicago, Illinois, U.S.A
| | - Jeffrey A Stanley
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, Michigan, U.S.A
| | - Matthew P Galloway
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, Michigan, U.S.A.,Department of Anesthesiology and Neuroimaging Center, Wayne State University, Detroit, Michigan, U.S.A
| | - Jeffrey A Loeb
- Department of Neurology and Rehabilitation, University of Illinois, Chicago, Illinois, U.S.A
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López-López D, Gómez-Nieto R, Herrero-Turrión MJ, García-Cairasco N, Sánchez-Benito D, Ludeña MD, López DE. Overexpression of the immediate-early genes Egr1, Egr2, and Egr3 in two strains of rodents susceptible to audiogenic seizures. Epilepsy Behav 2017; 71:226-237. [PMID: 26775236 DOI: 10.1016/j.yebeh.2015.12.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/10/2015] [Accepted: 12/12/2015] [Indexed: 11/17/2022]
Abstract
Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were exposed to high intensity auditory stimulation, and 60min later, the inferior colliculi were collected. As controls, intact Wistar rats and Syrian hamsters were subjected to stimulation and tissue preparation protocols identical to those performed on the experimental animals. Ribonucleic acid was isolated, and microarray analysis comparing the stimulated Wistar and WAR rats showed that the genomic profile of these animals displayed significant (fold change, |FC|≥2.0 and p<0.05) upregulation of 38 genes and downregulation of 47 genes. Comparison of gene expression profiles between stimulated control hamsters and stimulated GASH:Sal revealed the upregulation of 10 genes and the downregulation of 5 genes. Among the common genes that were altered in both models, we identified the zinc finger immediate-early growth response gene Egr3. The Egr3 protein is a transcription factor that is induced by distinct stress-elicited factors. Based on immunohistochemistry, this protein was expressed in the cochlear nucleus complex, the inferior colliculus, and the hippocampus of both animal models as well as in lymphoma tumors of the GASH:Sal. Our results support that the overexpression of the Egr3 gene in both models might contribute to neuronal viability and development of lymphoma in response to stress associated with audiogenic seizures. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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Affiliation(s)
- D López-López
- Institute for Neuroscience of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain; Salamanca Institute for Biomedical Research (IBSAL), Spain
| | - R Gómez-Nieto
- Institute for Neuroscience of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain; Salamanca Institute for Biomedical Research (IBSAL), Spain; Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain
| | - M J Herrero-Turrión
- Institute for Neuroscience of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
| | - N García-Cairasco
- Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil
| | - D Sánchez-Benito
- Institute for Neuroscience of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain; Salamanca Institute for Biomedical Research (IBSAL), Spain
| | - M D Ludeña
- Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain
| | - D E López
- Institute for Neuroscience of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain; Salamanca Institute for Biomedical Research (IBSAL), Spain; Department of Cell Biology and Pathology, School of Medicine, University of Salamanca, Salamanca, Spain.
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25
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Martínez-Levy GA, Rocha L, Rodríguez-Pineda F, Alonso-Vanegas MA, Nani A, Buentello-García RM, Briones-Velasco M, San-Juan D, Cienfuegos J, Cruz-Fuentes CS. Increased Expression of Brain-Derived Neurotrophic Factor Transcripts I and VI, cAMP Response Element Binding, and Glucocorticoid Receptor in the Cortex of Patients with Temporal Lobe Epilepsy. Mol Neurobiol 2017; 55:3698-3708. [PMID: 28527108 DOI: 10.1007/s12035-017-0597-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/03/2017] [Indexed: 12/19/2022]
Abstract
A body of evidence supports a relevant role of brain-derived neurotrophic factor (BDNF) in temporal lobe epilepsy (TLE). Magnetic resonance data reveal that the cerebral atrophy extends to regions that are functionally and anatomically connected with the hippocampus, especially the temporal cortex. We previously reported an increased expression of BDNF messenger for the exon VI in the hippocampus of temporal lobe epilepsy patients compared to an autopsy control group. Altered levels of this particular transcript were also associated with pre-surgical use of certain psychotropic. We extended here our analysis of transcripts I, II, IV, and VI to the temporal cortex since this cerebral region holds intrinsic communication with the hippocampus and is structurally affected in patients with TLE. We also assayed the cyclic adenosine monophosphate response element-binding (CREB) and glucocorticoid receptor (GR) genes as there is experimental evidence of changes in their expression associated with BDNF and epilepsy. TLE and pre-surgical pharmacological treatment were considered as the primary clinical independent variables. Transcripts BDNF I and BDNF VI increased in the temporal cortex of patients with pharmacoresistant TLE. The expression of CREB and GR expression follow the same direction. Pre-surgical use of selective serotonin reuptake inhibitors, carbamazepine (CBZ) and valproate (VPA), was associated with the differential expression of specific BDNF transcripts and CREB and GR genes. These changes could have functional implication in the plasticity mechanisms related to temporal lobe epilepsy.
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Affiliation(s)
- G A Martínez-Levy
- Department of Genetics, National Institute of Psychiatry "Ramón de la Fuente Muñiz" (INPRFM), Mexico City, Mexico
| | - L Rocha
- Department of Pharmacobiology, Center for Research and Advanced Studies, CINVESTAV, Mexico City, Mexico
| | - F Rodríguez-Pineda
- Department of Genetics, National Institute of Psychiatry "Ramón de la Fuente Muñiz" (INPRFM), Mexico City, Mexico
| | - M A Alonso-Vanegas
- Neurosurgery Section, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez" (INNNMVS), Mexico City, Mexico
| | - A Nani
- Department of Genetics, National Institute of Psychiatry "Ramón de la Fuente Muñiz" (INPRFM), Mexico City, Mexico
| | - R M Buentello-García
- Neurosurgery Section, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez" (INNNMVS), Mexico City, Mexico
| | - M Briones-Velasco
- Department of Genetics, National Institute of Psychiatry "Ramón de la Fuente Muñiz" (INPRFM), Mexico City, Mexico
| | - D San-Juan
- Clinical Research Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez" (INNNMVS), Mexico City, Mexico
| | - J Cienfuegos
- Neurosurgery Section, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez" (INNNMVS), Mexico City, Mexico
| | - C S Cruz-Fuentes
- Department of Genetics, National Institute of Psychiatry "Ramón de la Fuente Muñiz" (INPRFM), Mexico City, Mexico.
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26
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Sprissler RS, Wagnon JL, Bunton-Stasyshyn RK, Meisler MH, Hammer MF. Altered gene expression profile in a mouse model of SCN8A encephalopathy. Exp Neurol 2016; 288:134-141. [PMID: 27836728 DOI: 10.1016/j.expneurol.2016.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/06/2016] [Accepted: 11/03/2016] [Indexed: 02/07/2023]
Abstract
SCN8A encephalopathy is a severe, early-onset epilepsy disorder resulting from de novo gain-of-function mutations in the voltage-gated sodium channel Nav1.6. To identify the effects of this disorder on mRNA expression, RNA-seq was performed on brain tissue from a knock-in mouse expressing the patient mutation p.Asn1768Asp (N1768D). RNA was isolated from forebrain, cerebellum, and brainstem both before and after seizure onset, and from age-matched wildtype littermates. Altered transcript profiles were observed only in forebrain and only after seizures. The abundance of 50 transcripts increased more than 3-fold and 15 transcripts decreased more than 3-fold after seizures. The elevated transcripts included two anti-convulsant neuropeptides and more than a dozen genes involved in reactive astrocytosis and response to neuronal damage. There was no change in the level of transcripts encoding other voltage-gated sodium, potassium or calcium channels. Reactive astrocytosis was observed in the hippocampus of mutant mice after seizures. There is considerable overlap between the genes affected in this genetic model of epilepsy and those altered by chemically induced seizures, traumatic brain injury, ischemia, and inflammation. The data support the view that gain-of-function mutations of SCN8A lead to pathogenic alterations in brain function contributing to encephalopathy.
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Affiliation(s)
- Ryan S Sprissler
- ARL Division of Biotechnology, University of Arizona, Tucson, AZ 85721, USA
| | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Miriam H Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Michael F Hammer
- ARL Division of Biotechnology, University of Arizona, Tucson, AZ 85721, USA; Department of Neurology, University of Arizona, Tucson, AZ 85721, USA.
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27
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Oxytocin is involved in the proconvulsant effects of Sildenafil: Possible role of CREB. Toxicol Lett 2016; 256:44-52. [DOI: 10.1016/j.toxlet.2016.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 05/11/2016] [Accepted: 05/18/2016] [Indexed: 01/24/2023]
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28
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Xiang L, Ren Y, Li X, Zhao W, Song Y. MicroRNA-204 suppresses epileptiform discharges through regulating TrkB-ERK1/2-CREB signaling in cultured hippocampal neurons. Brain Res 2016; 1639:99-107. [DOI: 10.1016/j.brainres.2016.02.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/19/2016] [Accepted: 02/25/2016] [Indexed: 01/14/2023]
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29
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Wang W, Wang X, Chen L, Zhang Y, Xu Z, Liu J, Jiang G, Li J, Zhang X, Wang K, Wang J, Chen G, Luo J. The microRNA miR-124 suppresses seizure activity and regulates CREB1 activity. Expert Rev Mol Med 2016; 18:e4. [PMID: 26996991 PMCID: PMC4836211 DOI: 10.1017/erm.2016.3] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
miR-124, a brain-specific microRNA, was originally considered as a key regulator in neuronal differentiation and the development of the nervous system. Here we showed that miR-124 expression was suppressed in patients with epilepsy and rats after drug induced-seizures. Intrahippocampal administration of a miR-124 duplex led to alleviated seizure severity and prolonged onset latency in two rat models (pentylenetetrazole- and pilocarpine-induced seizures), while miR-124 inhibitor led to shortened onset latency in pilocarpine-induced seizure rat models. Moreover, the result of local field potentials (LFPs) records further demonstrated miR-124 may have anti-epilepsy function. Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR. In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis. A dual-luciferase reporter assay was used to confirm that miR-124 targeted directly the 3'UTR of CREB1 gene and repressed the CREB1 expression in HEK293T cells. Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus. These results revealed a previously unknown function of miR-124 in neuronal excitability and provided a new insight into molecular mechanisms underlying epilepsy.
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Affiliation(s)
- Wei Wang
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Xuefeng Wang
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing 100101, China
| | - Lang Chen
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Yujiao Zhang
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Zucai Xu
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Jing Liu
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Guohui Jiang
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Jie Li
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Xiaogang Zhang
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - KeWei Wang
- Peking University School of Medicine, 38 Xueyuan Road, Beijing 100091, China
| | - Jinghui Wang
- The Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | - Guojun Chen
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
| | - Jing Luo
- Department of Neurology, Chongqing Key Laboratory of Neurology, The First Affiliated Hospital of Chongqing Medical University, 1 Youyi Road, Chongqing 400016, China
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Vargas-Caballero M, Willaime-Morawek S, Gomez-Nicola D, Perry VH, Bulters D, Mudher A. The use of human neurons for novel drug discovery in dementia research. Expert Opin Drug Discov 2016; 11:355-67. [PMID: 26878555 DOI: 10.1517/17460441.2016.1154528] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Although many disease models exist for neurodegenerative disease, the translation of basic research findings to clinic is very limited. Studies using freshly resected human brain tissue, commonly discarded from neurosurgical procedures, should complement on-going work using stem cell-derived human neurons and glia thus increasing the likelihood of success in clinical trials. AREAS COVERED Herein, the authors discuss key issues in the lack of translation from basic research to clinic. They also review the evidence that human neurons, both freshly resected brain tissue and stem cell-derived neurons, such as induced pluripotent stem cells (iPSCs), can be used for analysis of physiological and molecular mechanisms in health and disease. Furthermore, the authors compare and contrast studies using live human brain tissue and studies using induced human stem cell-derived neuron models. Using an example from the area of neurodegeneration, the authors suggest that replicating elements of research findings from animals and stem cell models in resected human brain tissue would strengthen our understanding of disease mechanisms and the therapeutic strategies and aid translation. EXPERT OPINION The use of human brain tissue alongside iPSC-derived neural models can validate molecular mechanisms identified in rodent disease models and strengthen their relevance to humans. If drug target engagement and mechanism of cellular action can be validated in human brain tissue, this will increase the success rate in clinical research. The combined use of resected human brain tissue, alongside iPSC-derived neural models, could be considered a standard step in pre-clinical research and help to bridge the gap to clinical trials.
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Affiliation(s)
- Mariana Vargas-Caballero
- a Centre for Biological Sciences , University of Southampton , Southampton , UK.,b Institute for Life Sciences , University of Southampton , Southampton , UK
| | - Sandrine Willaime-Morawek
- c Clinical Neurosciences and Psychiatry, Faculty of Medicine and Centre for Human Development, Stem Cells and Regeneration , University of Southampton , Southampton , UK
| | - Diego Gomez-Nicola
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
| | - V Hugh Perry
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
| | - Diederik Bulters
- d Wessex Neurological Centre , Southampton General Hospital , Southampton , UK
| | - Amrit Mudher
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
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Serafini R, Dettloff S, Loeb JA. Neocortical slices from adult chronic epileptic rats exhibit discharges of higher voltages and broader spread. Neuroscience 2016; 322:509-24. [PMID: 26892299 DOI: 10.1016/j.neuroscience.2016.02.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/10/2016] [Accepted: 02/11/2016] [Indexed: 11/30/2022]
Abstract
Much of the current understanding of epilepsy mechanisms has been built on data recorded with one or a few electrodes from temporal lobe slices of normal young animals stimulated with convulsants. Mechanisms of adult, extratemporal, neocortical chronic epilepsy have not been characterized as much. A more advanced understanding of epilepsy mechanisms can be obtained by recording epileptiform discharges simultaneously from multiple points of an epileptic focus so as to define their sites of initiation and pathways of spreading. Brain slice recordings can characterize epileptic mechanisms in a simpler, more controlled preparation than in vivo. Yet, the intrinsic hyper-excitability of a chronic epileptic focus may not be entirely preserved in slices following the severing of connections in slice preparation. This study utilizes recordings of multiple electrode arrays to characterize which features of epileptic hyper-excitability present in in vivo chronic adult neocortical epileptic foci are preserved in brain slices. After tetanus toxin somatosensory cortex injections, adult rats manifest chronic spontaneous epileptic discharges both in the injection site (primary focus) and in the contralateral side (secondary focus). We prepared neocortical slices from these epileptic animals. When perfused with 4-Aminopyridine in a magnesium free medium, epileptic rat slices exhibit higher voltage discharges and broader spreading than control rat slices. Rates of discharges are similar in slices of epileptic and normal rats, however. Ictal and interictal discharges are distributed over most cortical layers, though with significant differences between primary and secondary foci. A chronic neocortical epileptic focus in slices does not show increased spontaneous pacemakers initiating epileptic discharges but shows discharges with higher voltages and broader spread, consistent with an enhanced synchrony of cellular and synaptic generators over wider surfaces.
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Affiliation(s)
- R Serafini
- Department of Neurology, University of Utah, Clinical Neuroscience Center, George E. Wahlen VA Medical Center, Salt Lake City, UT, United States.
| | - S Dettloff
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, United States
| | - J A Loeb
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, United States; Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, United States
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Human brain slices for epilepsy research: Pitfalls, solutions and future challenges. J Neurosci Methods 2015; 260:221-32. [PMID: 26434706 DOI: 10.1016/j.jneumeth.2015.09.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/21/2015] [Accepted: 09/23/2015] [Indexed: 12/17/2022]
Abstract
Increasingly, neuroscientists are taking the opportunity to use live human tissue obtained from elective neurosurgical procedures for electrophysiological studies in vitro. Access to this valuable resource permits unique studies into the network dynamics that contribute to the generation of pathological electrical activity in the human epileptic brain. Whilst this approach has provided insights into the mechanistic features of electrophysiological patterns associated with human epilepsy, it is not without technical and methodological challenges. This review outlines the main difficulties associated with working with epileptic human brain slices from the point of collection, through the stages of preparation, storage and recording. Moreover, it outlines the limitations, in terms of the nature of epileptic activity that can be observed in such tissue, in particular, the rarity of spontaneous ictal discharges, we discuss manipulations that can be utilised to induce such activity. In addition to discussing conventional electrophysiological techniques that are routinely employed in epileptic human brain slices, we review how imaging and multielectrode array recordings could provide novel insights into the network dynamics of human epileptogenesis. Acute studies in human brain slices are ultimately limited by the lifetime of the tissue so overcoming this issue provides increased opportunity for information gain. We review the literature with respect to organotypic culture techniques that may hold the key to prolonging the viability of this material. A combination of long-term culture techniques, viral transduction approaches and electrophysiology in human brain slices promotes the possibility of large scale monitoring and manipulation of neuronal activity in epileptic microcircuits.
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Zhu X, Dubey D, Bermudez C, Porter BE. Suppressing cAMP response element-binding protein transcription shortens the duration of status epilepticus and decreases the number of spontaneous seizures in the pilocarpine model of epilepsy. Epilepsia 2015; 56:1870-8. [PMID: 26419901 DOI: 10.1111/epi.13211] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2015] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Current epilepsy therapies directed at altering the function of neurotransmitter receptors or ion channels, or release of synaptic vesicles fail to prevent seizures in approximately 30% of patients. A better understanding of the molecular mechanism underlying epilepsy is needed to provide new therapeutic targets. The activity of cyclic AMP (cAMP) response element-binding protein (CREB), a major transcription factor promoting CRE-mediated transcription, increases following a prolonged seizure called status epilepticus. It is also increased in the seizure focus of patients with medically intractable focal epilepsy. Herein we explored the effect of acute suppression of CREB activity on status epilepticus and spontaneous seizures in a chronic epilepsy model. METHODS Pilocarpine chemoconvulsant was used to induce status epilepticus. To suppress CREB activity, a transgenic mouse line expressing an inducible dominant negative mutant of CREB (CREB(IR) ) with a serine to alanine 133 substitution was used. Status epilepticus and spontaneous seizures of transgenic and wild-type mice were analyzed using video-electroencephalography (EEG) to assess the effect of CREB suppression on seizures. RESULTS Our findings indicate that activation of CREB(IR) shortens the duration of status epilepticus. The frequency of spontaneous seizures decreased in mice with chronic epilepsy during CREB(IR) induction; however, the duration of the spontaneous seizures was unchanged. Of interest, we found significantly reduced levels of phospho-CREB Ser133 upon activation of CREB(IR) , supporting prior work suggesting that binding to the CRE site is important for CREB phosphorylation. SIGNIFICANCE Our results suggest that CRE transcription supports seizure activity both during status epilepticus and in spontaneous seizures. Thus, blocking of CRE transcription is a novel target for the treatment of epilepsy.
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Affiliation(s)
- Xinjian Zhu
- Department of Pediatrics and Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A.,Department of Pharmacology, Medical School of Southeast University, Nanjing, China
| | - Deepti Dubey
- The Department of Neurology, School of Medicine, Stanford University, Stanford, California, U.S.A
| | - Camilo Bermudez
- Department of Pediatrics and Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
| | - Brenda E Porter
- Department of Pediatrics and Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A.,The Department of Neurology, School of Medicine, Stanford University, Stanford, California, U.S.A.,The Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
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Pennacchio P, Noé F, Gnatkovsky V, Moroni RF, Zucca I, Regondi MC, Inverardi F, de Curtis M, Frassoni C. Increased pCREB expression and the spontaneous epileptiform activity in a BCNU-treated rat model of cortical dysplasia. Epilepsia 2015; 56:1343-54. [DOI: 10.1111/epi.13070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Paolo Pennacchio
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesco Noé
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Vadym Gnatkovsky
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ramona Frida Moroni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ileana Zucca
- Scientific Department; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Maria Cristina Regondi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesca Inverardi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Marco de Curtis
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Carolina Frassoni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
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Mittal S, Barkmeier D, Hua J, Pai DS, Fuerst D, Basha M, Loeb JA, Shah AK. Intracranial EEG analysis in tumor-related epilepsy: Evidence of distant epileptic abnormalities. Clin Neurophysiol 2015; 127:238-244. [PMID: 26493495 DOI: 10.1016/j.clinph.2015.06.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/04/2015] [Accepted: 06/10/2015] [Indexed: 01/12/2023]
Abstract
OBJECTIVE In patients with tumor-related epilepsy (TRE), surgery traditionally focuses on tumor resection; but identification and removal of associated epileptogenic zone may improve seizure outcome. Here, we study spatial relationship of tumor and seizure onset and early spread zone (SOSz). We also perform quantitative analysis of interictal epileptiform activities in patients with both TRE and non-lesional epilepsy in order to better understand the electrophysiological basis of epileptogenesis. METHODS Twenty-five patients (11 with TRE and 14 with non-lesional epilepsy) underwent staged surgery using intracranial electrodes. Tumors were outlined on MRI and images were coregistered with post-implantation CT images. For each electrode, distance to the nearest tumor margin was measured. Electrodes were categorized based on distance from tumor and involvement in seizure. Quantitative EEG analysis studying frequency, amplitude, power, duration and slope of interictal spikes was performed. RESULTS At least part of the SOSz was located beyond 1.5 cm from the tumor margin in 10/11 patients. Interictally, spike frequency and power were higher in the SOSz and spikes near tumor were smaller and less sharp. Interestingly, peritumoral electrodes had the highest spike frequencies and sharpest spikes, indicating greatest degree of epileptic synchrony. A complete resection of the SOSz resulted in excellent seizure outcome. CONCLUSIONS Seizure onset and early spread often involves brain areas distant from the tumor. SIGNIFICANCE Utilization of epilepsy surgery approach for TRE may provide better seizure outcome and study of the intracranial EEG may provide insight into pathophysiology of TRE.
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Affiliation(s)
- S Mittal
- Department of Neurosurgery, Wayne State University, Detroit, MI, USA; Department of Oncology, Wayne State University, Detroit, MI, USA; Comprehensive Epilepsy Center, Detroit Medical Center, Wayne State University, Detroit, MI, USA; Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - D Barkmeier
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA
| | - J Hua
- Department of Computer Science, Wayne State University, Detroit, MI, USA
| | - D S Pai
- Department of Computer Science, Wayne State University, Detroit, MI, USA
| | - D Fuerst
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - M Basha
- Comprehensive Epilepsy Center, Detroit Medical Center, Wayne State University, Detroit, MI, USA; Department of Neurology, Wayne State University, Detroit, MI, USA
| | - J A Loeb
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, USA; Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, USA
| | - A K Shah
- Comprehensive Epilepsy Center, Detroit Medical Center, Wayne State University, Detroit, MI, USA; Department of Neurology, Wayne State University, Detroit, MI, USA.
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Karnati HK, Panigrahi M, Shaik NA, Greig NH, Bagadi SAR, Kamal MA, Kapalavayi N. Down regulated expression of Claudin-1 and Claudin-5 and up regulation of β-catenin: association with human glioma progression. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2015; 13:1413-26. [PMID: 25345514 DOI: 10.2174/1871527313666141023121550] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 06/24/2014] [Accepted: 07/02/2014] [Indexed: 12/21/2022]
Abstract
Glioblastoma multiforme is the most common form of intracranial malignancy in humans, and is characterized by aggressive tumor growth, tissue invasion and neurodegenerative properties. The present study investigated the expression status of tight junction associated Claudin 1 (CLDN1), Claudin 5 (CLDN5) and Adheren junction associated β-catenin genes in the light of their critical role in the progression of both low- and high-grade human gliomas. Using quantitative PCR and Western blot methods the mRNA and protein status of CLDN1, CLDN5 and β-catenin genes were studied in a total of 25 human gliomas of World Health Organization (WHO) grades I-IV, non-cancerous control brain tissues and their corresponding model cell lines (C6, U373, U118, T98 and U87MG). Quantitative analysis of the transcript and protein expression data showed that CLDN1 and CLDN5 were significantly down regulated (p=<0.001) in tumors of all four grades and model cell lines. This decrease in expression pattern was in accordance with the increasing grade of the tumor. A 4-fold stronger reduction of CLDN1 when compared to CLDN5 was evident in high-grade tumors. Interestingly, β-catenin was up regulated in all tumor types we studied (p=<0.005). Our findings, suggest that down regulated CLDN1 and CLDN5 genes have potential relevance in relation to the progression of glioblastoma multiforme. Hence, their therapeutic targeting may provide both insight and leads to control the cellular proliferation and subsequent invasiveness among affected individuals.
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Affiliation(s)
| | | | | | | | | | | | - Nagaiah Kapalavayi
- (Nagaiah Kapalavayi) Department of Biotechnology, Gland Pharma Limited, Dundigal, Gandimaisamma X Roads, Hyderabad - 500 043, Andhra Pradesh, India.
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Serafini R, Andrade R, Loeb JA. Coalescence of deep and superficial epileptic foci into larger discharge units in adult rat neocortex. Neuroscience 2015; 292:148-58. [PMID: 25701714 DOI: 10.1016/j.neuroscience.2015.02.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/06/2015] [Accepted: 02/10/2015] [Indexed: 11/19/2022]
Abstract
Epilepsy is a disease of neuronal hyper-synchrony that can involve both neocortical and hippocampal brain regions. While much is known about the network properties of the hippocampus little is known of how epileptic neocortical hyper-synchrony develops. We aimed at characterizing the properties of epileptic discharges of a neocortical epileptic focus. We established a multi-electrode-array method to record the spatial patterns of epileptiform potentials in acute adult rat brain slices evoked by 4-Aminopyridine in the absence of magnesium. Locations of discharges mapped to two anatomical regions over the somatosensory cortex and over the lateral convexity separated by a gap at a location matching the dysgranular zone. Focal epileptiform discharges were recorded in superficial and deep neocortical layers but over superficial layers, they exhibited larger surface areas. They were often independent even when closely spaced to one another but they became progressively coupled resulting in larger zones of coherent discharge. The gradual coupling of multiple, independent, closely spaced, spatially restricted, focal discharges between deep and superficial neocortical layers represents a possible mechanism of the development of an epileptogenic zone.
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Affiliation(s)
- Ruggero Serafini
- Department of Neurology, University of Utah, Clinical Neuroscience Center, Salt Lake City, UT, United States; George E. Wahlen VA Medical Center, Salt Lake City, UT, United States.
| | - Rodrigo Andrade
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Jeffrey A Loeb
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, United States; Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, United States
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Dachet F, Bagla S, Keren-Aviram G, Morton A, Balan K, Saadat L, Valyi-Nagy T, Kupsky W, Song F, Dratz E, Loeb JA. Predicting novel histopathological microlesions in human epileptic brain through transcriptional clustering. ACTA ACUST UNITED AC 2014; 138:356-70. [PMID: 25516101 DOI: 10.1093/brain/awu350] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although epilepsy is associated with a variety of abnormalities, exactly why some brain regions produce seizures and others do not is not known. We developed a method to identify cellular changes in human epileptic neocortex using transcriptional clustering. A paired analysis of high and low spiking tissues recorded in vivo from 15 patients predicted 11 cell-specific changes together with their 'cellular interactome'. These predictions were validated histologically revealing millimetre-sized 'microlesions' together with a global increase in vascularity and microglia. Microlesions were easily identified in deeper cortical layers using the neuronal marker NeuN, showed a marked reduction in neuronal processes, and were associated with nearby activation of MAPK/CREB signalling, a marker of epileptic activity, in superficial layers. Microlesions constitute a common, undiscovered layer-specific abnormality of neuronal connectivity in human neocortex that may be responsible for many 'non-lesional' forms of epilepsy. The transcriptional clustering approach used here could be applied more broadly to predict cellular differences in other brain and complex tissue disorders.
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Affiliation(s)
- Fabien Dachet
- 1 Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Shruti Bagla
- 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Gal Keren-Aviram
- 3 Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Andrew Morton
- 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Karina Balan
- 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Laleh Saadat
- 1 Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Tibor Valyi-Nagy
- 1 Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA 4 Department of Pathology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - William Kupsky
- 5 Department of Pathology; Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Fei Song
- 1 Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Edward Dratz
- 3 Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Jeffrey A Loeb
- 1 Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA 2 The Centre for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Mittal S, Shah AK, Barkmeier DT, Loeb JA. Systems biology of human epilepsy applied to patients with brain tumors. Epilepsia 2013; 54 Suppl 9:35-9. [DOI: 10.1111/epi.12441] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sandeep Mittal
- Department of Neurosurgery; Wayne State University; Detroit Michigan U.S.A
- Karmanos Cancer Institute; Wayne State University; Detroit Michigan U.S.A
| | - Aashit K. Shah
- Department of Neurology; Wayne State University; Detroit Michigan U.S.A
| | - Daniel T. Barkmeier
- The Center for Molecular Medicine and Genetics; Wayne State University; Detroit Michigan U.S.A
| | - Jeffrey A. Loeb
- The Center for Molecular Medicine and Genetics; Wayne State University; Detroit Michigan U.S.A
- Department of Neurology and Rehabilitation; University of Illinois at Chicago; Chicago Illinois U.S.A
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Song F, Chiang P, Ravits J, Loeb JA. Activation of microglial neuregulin1 signaling in the corticospinal tracts of ALS patients with upper motor neuron signs. Amyotroph Lateral Scler Frontotemporal Degener 2013; 15:77-83. [DOI: 10.3109/21678421.2013.853802] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Song F, Bandara M, Deol H, Loeb JA, Benjamins J, Lisak RP. Complexity of trophic factor signaling in experimental autoimmune encephalomyelitis: differential expression of neurotrophic and gliotrophic factors. J Neuroimmunol 2013; 262:11-8. [PMID: 23763772 DOI: 10.1016/j.jneuroim.2013.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/22/2013] [Accepted: 05/17/2013] [Indexed: 02/07/2023]
Abstract
Soluble factors that promote survival and differentiation of glia and neurons during development are likely to play key roles in neurodegeneration and demyelinating diseases such as multiple sclerosis (MS) and have the potential to be important therapeutic targets. We examined the effect of TrkB signaling and the expression patterns of neurotrophic and gliotrophic factors in the mouse brain in MOG-induced experimental allergic encephalomyelitis (EAE). With induction of mild disease, TrkB heterozygous mice were more severely affected compared to their wild type littermates. However, with more potent disease induction, TrkB heterozygotes fared similar to their wild type littermates, suggesting complex modulatory roles for TrkB signaling. One possible explanation for this difference is that the expression patterns of neurotrophic factors correlate with disease severity in individual mice with mild disease, but not in more severe disease. With the less potent induction in C57BL/6 mice, we found that BDNF was consistently increased at EAE onset, while the soluble gliotrophic factor neuregulin (NRG1) was increased only in the chronic phase of the disease. Treatment of these animals with glatiramer acetate (GA) to decrease disease severity resulted in lower levels of both BDNF and NRG1 expression in some mice at 35days after immunization compared to those in untreated EAE mice, but had no direct effect on these factors in the absence of EAE. Our results suggest a complex interplay between neurotrophic and gliotrophic factors in EAE that is dependent on disease stage and severity. While signaling by BDNF through TrkB is protective in mild disease, this effect was not seen in more severe disease. The late induction of NRG1 in the chronic stage of disease could also worsen disease severity through its known ability to activate microglial, inflammatory pathways. While complex, these studies begin to define underlying axoglial trophic activities that are likely involved in both disease pathogenesis and repair.
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Affiliation(s)
- Fei Song
- Department of Neurology, Wayne State University, Detroit, MI 48201, United States; The Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI 48201, United States; Department of Immunology and Microbiology, Wayne State University, Detroit, MI 48201, United States.
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Sterner KN, Mcgowen MR, Chugani HT, Tarca AL, Sherwood CC, Hof PR, Kuzawa CW, Boddy AM, Raaum RL, Weckle A, Lipovich L, Grossman LI, Uddin M, Goodman M, Wildman DE. Characterization of human cortical gene expression in relation to glucose utilization. Am J Hum Biol 2013; 25:418-30. [DOI: 10.1002/ajhb.22394] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 02/25/2013] [Indexed: 01/12/2023] Open
Affiliation(s)
- Kirstin N. Sterner
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | - Michael R. Mcgowen
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | | | - Adi L. Tarca
- Department of Computer Science; Wayne State University; Detroit; Michigan; 48202
| | - Chet C. Sherwood
- Department of Anthropology; The George Washington University; Washington; DC; 20052
| | - Patrick R. Hof
- Fishberg Department of Neuroscience and Friedman Brian Institute; Mount Sinai School of Medicine; New York; New York; 10029
| | | | - Amy M. Boddy
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | - Ryan L. Raaum
- Department of Anthropology, Lehman College and The Graduate Center; City University of New York; Bronx; New York; 10468
| | - Amy Weckle
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | - Leonard Lipovich
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | - Lawrence I. Grossman
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
| | - Monica Uddin
- Center for Molecular Medicine and Genetics; Wayne State University School of Medicine; Detroit; Michigan; 48201
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Abstract
Benign epilepsy with centrotemporal spikes, early-onset childhood occipital epilepsy (Panayiotopoulos syndrome [PS]) and late-onset childhood occipital epilepsy (Gastaut type [LOCE-G]) are the principal pediatric focal epilepsy syndromes. They share major common characteristics: the appearance and resolution of electroclinical features are age related, there is a strong genetic predisposition, the clinical course is often mild with infrequent and easy to control seizures, interictal epileptiform activity is disproportionately abundant when compared with the clinical correlate, and tends to potentiate and generalize during sleep. In this review, we outline the relevant pathophysiology underlying this electroclinical spectrum. Then, the initial description of individual syndromes is followed by a summary of overlapping features and intermediate presentations that question the boundaries between these entities and provide the basis for the concept of a childhood seizure susceptibility syndrome. Additionally, we outline the main features of the related epileptic encephalopathies. An outlook on potential future lines of research completes this review.
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Changes in the Egr1 and Arc expression in brain structures of pentylenetetrazole-kindled rats. Pharmacol Rep 2013; 65:368-78. [DOI: 10.1016/s1734-1140(13)71012-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 11/07/2012] [Indexed: 11/20/2022]
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Bhowmik M, Khanam R, Vohora D. Histamine H3 receptor antagonists in relation to epilepsy and neurodegeneration: a systemic consideration of recent progress and perspectives. Br J Pharmacol 2012; 167:1398-414. [PMID: 22758607 PMCID: PMC3514756 DOI: 10.1111/j.1476-5381.2012.02093.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 05/03/2012] [Accepted: 06/12/2012] [Indexed: 12/22/2022] Open
Abstract
The central histaminergic actions are mediated by H(1) , H(2) , H(3) and H(4) receptors. The histamine H(3) receptor regulates the release of histamine and a number of other neurotransmitters and thereby plays a role in cognitive and homeostatic processes. Elevated histamine levels suppress seizure activities and appear to confer neuroprotection. The H(3) receptors have a number of enigmatic features like constitutive activity, interspecies variation, distinct ligand binding affinities and differential distribution of prototypic splice variants in the CNS. Furthermore, this Gi/Go-protein-coupled receptor modulates several intracellular signalling pathways whose involvement in epilepsy and neurotoxicity are yet to be ascertained and hence represent an attractive target in the search for new anti-epileptogenic drugs. So far, H(3) receptor antagonists/inverse agonists have garnered a great deal of interest in view of their promising therapeutic properties in various CNS disorders including epilepsy and related neurotoxicity. However, a number of experiments have yielded opposing effects. This article reviews recent works that have provided evidence for diverse mechanisms of antiepileptic and neuroprotective effects that were observed in various experimental models both in vitro and in vivo. The likely reasons for the apparent disparities arising from the literature are also discussed with the aim of establishing a more reliable basis for the future use of H(3) receptor antagonists, thus improving their utility in epilepsy and associated neurotoxicity.
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Affiliation(s)
- M Bhowmik
- Neurobehavioral Pharmacology Laboratory, Department of Pharmacology, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi, India
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Sakharnova TA, Vedunova MV, Mukhina IV. Brain-derived neurotrophic factor (BDNF) and its role in the functioning of the central nervous system. NEUROCHEM J+ 2012. [DOI: 10.1134/s1819712412030129] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Abstract
The circadian pattern of seizures in people with epilepsy (PWE) was first described two millennia ago. However, these phenomena have not received enough scientific attention, possibly due to the lack of promising hypotheses to address the interaction between seizure generation and a physiological clock. To propose testable hypotheses at the molecular level, interactions between circadian rhythm, especially transcription factors governing clock genes expression, and the mTOR (mammalian target of rapamycin) signaling pathway, the major signaling pathway in epilepsy, will be reviewed. Then, two closely related hypotheses will be proposed: (1) Rhythmic activity of hyperactivated mTOR signaling molecules results in rhythmic increases in neuronal excitability. These rhythmic increases in excitability periodically exceed the seizure threshold, displaying the behavioral seizures. (2) Oscillation of neuronal excitability in SCN modulates the rhythmic excitability in the hippocampus through subiculum via long-range projections. Findings from published results, their implications, and proposals for new experiments will be discussed. These attempts may ignite further discussion on what we still need to learn about the rhythmicity of spontaneous seizures.
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Affiliation(s)
- Chang-Hoon Cho
- Epilepsy Research Laboratory, Department of Pediatrics, Children's Hospital of Philadelphia Philadelphia, PA, USA
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Beaumont TL, Yao B, Shah A, Kapatos G, Loeb JA. Layer-specific CREB target gene induction in human neocortical epilepsy. J Neurosci 2012; 32:14389-401. [PMID: 23055509 PMCID: PMC3478758 DOI: 10.1523/jneurosci.3408-12.2012] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 07/17/2012] [Accepted: 08/20/2012] [Indexed: 11/21/2022] Open
Abstract
Epilepsy is a disorder of recurrent seizures that affects 1% of the population. To understand why some areas of cerebral cortex produce seizures and others do not, we identified differentially expressed genes in human epileptic neocortex compared with nearby regions that did not produce seizures. The transcriptome that emerged strongly implicates MAPK signaling and CREB-dependent transcription, with 74% of differentially expressed genes containing a cAMP response element (CRE) in their proximal promoter, more than half of which are conserved. Despite the absence of recent seizures in these patients, epileptic brain regions prone to seizures showed persistent activation of ERK and CREB. Persistent CREB activation was directly linked to CREB-dependent gene transcription by chromatin immunoprecipitation that showed phosphorylated CREB constitutively associated with the proximal promoters of many of the induced target genes involved in neuronal signaling, excitability, and synaptic plasticity. A distinct spatial pattern of ERK activation was seen in superficial axodendritic processes of epileptic neocortex that colocalized with both CREB phosphorylation and CREB target gene induction in well demarcated populations of layer 2/3 neurons. These same neuronal lamina showed a marked increase in synaptic density. The findings generated in this study generate a robust and spatially restricted pattern of epileptic biomarkers and associated synaptic changes that could lead to new mechanistic insights and potential therapeutic targets for human epilepsy.
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Affiliation(s)
- Thomas L. Beaumont
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201
| | | | | | - Gregory Kapatos
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201
| | - Jeffrey A. Loeb
- Department of Neurology and
- The Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201
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49
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Abstract
While most gene transcription yields RNA transcripts that code for proteins, a sizable proportion of the genome generates RNA transcripts that do not code for proteins, but may have important regulatory functions. The brain-derived neurotrophic factor (BDNF) gene, a key regulator of neuronal activity, is overlapped by a primate-specific, antisense long noncoding RNA (lncRNA) called BDNFOS. We demonstrate reciprocal patterns of BDNF and BDNFOS transcription in highly active regions of human neocortex removed as a treatment for intractable seizures. A genome-wide analysis of activity-dependent coding and noncoding human transcription using a custom lncRNA microarray identified 1288 differentially expressed lncRNAs, of which 26 had expression profiles that matched activity-dependent coding genes and an additional 8 were adjacent to or overlapping with differentially expressed protein-coding genes. The functions of most of these protein-coding partner genes, such as ARC, include long-term potentiation, synaptic activity, and memory. The nuclear lncRNAs NEAT1, MALAT1, and RPPH1, composing an RNAse P-dependent lncRNA-maturation pathway, were also upregulated. As a means to replicate human neuronal activity, repeated depolarization of SY5Y cells resulted in sustained CREB activation and produced an inverse pattern of BDNF-BDNFOS co-expression that was not achieved with a single depolarization. RNAi-mediated knockdown of BDNFOS in human SY5Y cells increased BDNF expression, suggesting that BDNFOS directly downregulates BDNF. Temporal expression patterns of other lncRNA-messenger RNA pairs validated the effect of chronic neuronal activity on the transcriptome and implied various lncRNA regulatory mechanisms. lncRNAs, some of which are unique to primates, thus appear to have potentially important regulatory roles in activity-dependent human brain plasticity.
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Simonato M, Löscher W, Cole AJ, Dudek FE, Engel J, Kaminski RM, Loeb JA, Scharfman H, Staley KJ, Velíšek L, Klitgaard H. Finding a better drug for epilepsy: preclinical screening strategies and experimental trial design. Epilepsia 2012; 53:1860-7. [PMID: 22708847 DOI: 10.1111/j.1528-1167.2012.03541.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The antiepileptic drugs (AEDs) introduced during the past two decades have provided several benefits: they offered new treatment options for symptomatic treatment of seizures, improved ease of use and tolerability, and lowered risk for hypersensitivity reactions and detrimental drug-drug interactions. These drugs, however, neither attenuated the problem of drug-refractory epilepsy nor proved capable of preventing or curing the disease. Therefore, new preclinical screening strategies are needed to identify AEDs that target these unmet medical needs. New therapies may derive from novel targets identified on the basis of existing hypotheses for drug-refractory epilepsy and the biology of epileptogenesis; from research on genetics, transcriptomics, and epigenetics; and from mechanisms relevant for other therapy areas. Novel targets should be explored using new preclinical screening strategies, and new technologies should be used to develop medium- to high-throughput screening models. In vivo testing of novel drugs should be performed in models mimicking relevant aspects of drug refractory epilepsy and/or epileptogenesis. To minimize the high attrition rate associated with drug development, which arises mainly from a failure to demonstrate sufficient clinical efficacy of new treatments, it is important to define integrated strategies for preclinical screening and experimental trial design. An important tool will be the discovery and implementation of relevant biomarkers that will facilitate a continuum of proof-of-concept approaches during early clinical testing to rapidly confirm or reject preclinical findings, and thereby lower the risk of the overall development effort. In this review, we overview some of the issues related to these topics and provide examples of new approaches that we hope will be more successful than those used in the past.
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Affiliation(s)
- Michele Simonato
- Section of Pharmacology, Department of Clinical and Experimental Medicine, University of Ferrara, and National Institute of Neuroscience, via Fossato di Mortara 17-19, Ferrara, Italy.
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