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Sabetghadam A, Wu C, Liu J, Zhang L, Reid AY. Increased epileptogenicity in a mouse model of neurofibromatosis type 1. Exp Neurol 2020; 331:113373. [PMID: 32502580 DOI: 10.1016/j.expneurol.2020.113373] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/22/2020] [Accepted: 06/01/2020] [Indexed: 11/19/2022]
Abstract
RATIONALE Neurofibromatosis type 1 (NF1) is associated with higher rates of epilepsy compared to the general population. Some NF1 patients with epilepsy do not have intracranial lesions, suggesting the genetic mutation itself may contribute to higher rates of epilepsy in these patients. We have recently demonstrated increased seizure susceptibility in the Nf1+/- mouse, but it is unknown whether this model displays altered epileptogenicity, as has been reported in patients with NF1. The aim of this study was to determine whether the Nf1+/- mouse is more susceptible to electrical kindling-induced epileptogenesis. METHODS Young male or female adult Nf1+/- or Nf1+/+ (wild-type; WT) mice were implanted with electrodes for neocortical or hippocampal kindling paradigms. Neocortical kindling was performed for 40 stimulation sessions followed by baseline EEG monitoring to detect possible SRSs. Hippocampal kindling was performed with a modified extended kindling paradigm, completed to a maximum of 80 sessions to try to induce spontaneous repetitive seizures (SRSs). Western blot assays were performed in naïve and kindled mice to compare levels of Akt and MAPK (ERK1/2), proteins downstream of the NF1 mutation. RESULTS The average initial neocortical after-discharge threshold (ADT) was significantly lower in the Nf1+/- group, which also required fewer stimulations to reach stage 5 seizure, had greater average seizure severity across all kindling sessions, had a greater number of convulsive seizures, and had a faster progression of after-discharge duration and Racine score during kindling. No WT mice exhibited SRS after neocortical kindling, versus 33% of Nf1+/- mice. The average initial hippocampal ADT was not significantly different between the WT and Nf1+/- groups, nor was there a difference in the number of stimulations required to reach the kindled state. The WT group had a significantly higher average seizure severity across all kindling sessions as compared with the Nf1+/- mice. The WT group also had faster progression of the Racine seizure score over the kindling sessions, mainly due to a faster increase in seizures severity early during the kindling process. However, SRSs were seen in 50% of Nf1+/- mice after modified extended kindling and in no WT mice. Western blots showed hippocampal kindling increased the ratio of phosphorylated/total Akt in both the WT and Nf1+/- mice, while neocortical kindling led to increased ratios of phosphorylated/total Akt and MAPK in Nf1+/- mice only. CONCLUSIONS We have demonstrated for the first time an increased rate of epileptogenesis in an animal model of NF1 with no known macroscopic/neoplastic brain lesions. This work provides evidence for the genetic mutation itself playing a role in seizures and epilepsy in patients with NF1, and supports the use of the Nf1+/- mouse model in future mechanistic studies.
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Affiliation(s)
- A Sabetghadam
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada.
| | - C Wu
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - J Liu
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - L Zhang
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
| | - A Y Reid
- Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada
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Asadi S, Roohbakhsh A, Shamsizadeh A, Fereidoni M, Kordijaz E, Moghimi A. The effect of intracerebroventricular administration of orexin receptor type 2 antagonist on pentylenetetrazol-induced kindled seizures and anxiety in rats. BMC Neurosci 2018; 19:49. [PMID: 30103703 PMCID: PMC6090721 DOI: 10.1186/s12868-018-0445-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 07/17/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Current antiepileptic drugs are not able to prevent recurrent seizures in all patients. Orexins are excitatory hypothalamic neuropeptides that their receptors (Orx1R and Orx2R) are found almost in all major regions of the brain. Pentylenetetrazol (PTZ)-induced kindling is a known experimental model for epileptic seizures. The purpose of this study was to evaluate the effect of Orx2 receptor antagonist (TCS OX2 29) on seizures and anxiety of PTZ-kindled rats. RESULTS Our results revealed that similar to valproate, administration of 7 µg/rat of TCS OX2 29 increased the latency period and decreased the duration time of 3rd and 4th stages of epileptiform seizures. Besides, it significantly decreased mean of seizure scores. However, TCS OX2 29 did not modulate anxiety induced by repeated PTZ administration. CONCLUSION This study showed that blockade of Orx2 receptor reduced seizure-related behaviors without any significant effect on PTZ-induced anxiety.
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Affiliation(s)
- Saeedeh Asadi
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Masoud Fereidoni
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Elham Kordijaz
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Ali Moghimi
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran.
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Behavioral and Neurochemical Consequences of Pentylenetetrazol-Induced Kindling in Young and Middle-Aged Rats. Pharmaceuticals (Basel) 2017; 10:ph10030075. [PMID: 28902172 PMCID: PMC5620619 DOI: 10.3390/ph10030075] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/07/2017] [Accepted: 09/09/2017] [Indexed: 11/23/2022] Open
Abstract
(1) Objectives: Epilepsy disorder is likely to increase with aging, leading to an increased incidence of comorbidities and mortality. In spite of that, there is a lack of information regarding this issue and little knowledge of cognitive and emotional responses in aging subjects following epileptogenesis. We investigated whether and how aging distress epilepsy-related behavioral and biochemical outcomes are associated with cognition and emotion. (2) Methods: Young and middle-aged Wistar rats (3 or 12 months old) were treated with pentylenetetrazol (PTZ, 35 mg/kg) and injected on alternated days for 20 (young rats) and 32 days (middle-aged rats). Kindling was reached after two consecutive stages 4 plus one stage 5 or 6 in Racine scale. Control and kindled rats were evaluated in the elevated plus-maze (EPM) and object-recognition tests and their hippocampus was collected 24 h later for mitogen-activated protein kinases (MAPK) dosage. (3) Results: Middle-aged rats presented a higher resistance to develop kindling, with a decrease in the seizure severity index observed following the 4th and 9th PTZ injections. Middle-aged rats displayed an increased duration of the first myoclonic seizure and an increased latency to the first generalized seizure when compared to younger rats. The induction of kindling did not impair the animals’ performance (regardless of age) in the object-recognition task and the EPM test as well as it did not alter the hippocampal levels of MAPKs. (4) Significance: Our findings reveal that, despite age-related differences during epileptogenesis, middle-aged rats evaluated after kindling performed similarly during discriminative learning and emotional tasks in comparison to young animals, with no alteration of hippocampal MAPKs. Additional investigation must be carried out to explore the electrophysiological mechanisms underlying these responses, as well as the long-term effects displayed after kindling.
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Kaur N, Singh T, Kumar S, Goel RK. Neurochemical evidence based suggested therapy for safe management of epileptogenesis. Epilepsy Behav 2017; 72:8-16. [PMID: 28570965 DOI: 10.1016/j.yebeh.2017.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/18/2017] [Accepted: 04/03/2017] [Indexed: 01/05/2023]
Abstract
Most of the clinically available antiepileptic drugs have only antiseizure effects and are reported unable to prevent epileptogenesis. In the past decade, several drugs underwent clinical trials for management of epileptogenesis, but none of the drugs tested was found effective. One of the major lacunas is availability of appropriate preclinical approaches to delineate mechanisms of epileptogenesis. Thus, the present study attempts to suggest a neurochemistry based approach for safe management of epileptogenesis. The altered neurochemical milieu in amygdala, cortex and hippocampus areas of the mice brain in naïve, kindled and kindling resistant animals has been delineated. The endogenous natural antiepileptogenic neurochemical defense mechanism observed in kindling resistant animals may uncover neurochemical mechanisms of epileptogenesis and in turn suggest us novel interventions for safe management of epileptogenesis. The kindling epileptogenesis was carried out in two month old male Swiss albino mice by administering subconvulsive pentylenetetrazole (35mg/kg; i.p.) at an interval of 48±2h for 42days. 2h after the last pentylenetetrazole injection, the animals were subjected to behavioral evaluations. Four hours after behavioral evaluation, all animals were euthanized and discrete parts of brain (amygdala, cortex and hippocampus) were harvested for neurochemical analysis. Results revealed that 60% of animals responded to kindling as observed with decreased seizure threshold, while the rest were found resistant. The kindled animals were found to be associated with anxiety, depression and cognitive impairment; while in kindling resistant animals no such behavioral deficits were observed. The neurochemical analysis revealed that in kindled animals altered glutamate-GABA neurotransmission, and decreased taurine, glycine, d-serine, monoamine levels with elevated indoleamine 2,3-dioxygenase activity were observed, which may be convicted for progression of kindling epileptogenesis. However, in kindling resistant animals elevated GABA, taurine, tryptophan, serotonin, glycine, and d-serine levels with decreased indoleamine 2,3-dioxygenase activity were observed as natural endogenous antiepileptogenic mechanisms, which may be foreseen as safe pharmacological targets for management of epileptogenesis.
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Affiliation(s)
- Navjot Kaur
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Tanveer Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Sandeep Kumar
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Rajesh Kumar Goel
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India.
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P38 MAPK pathway mediates cognitive damage in pentylenetetrazole-induced epilepsy via apoptosis cascade. Epilepsy Res 2017; 133:89-92. [PMID: 28472735 DOI: 10.1016/j.eplepsyres.2017.04.012] [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: 01/07/2017] [Revised: 03/26/2017] [Accepted: 04/15/2017] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Our group has previously reported the role of P38 mitogen-activated protein kinase (MAPK) pathway in the memory impairment of pentylenetetrazole (PTZ)-kindled rats. However, any contribution of p38 MAPK pathways to the cognitive dysfunction of PTZ-kindled rats remains unclear. The objective of this study is to verify the relationship between p38 MAPK pathway and cognitive function of epileptic rats, and discuss probable mechanisms. METHODS Thirty male SD rats were divided into three groups, namely, PTZ, inhibitor, and sham groups. All rats except those from the sham group were treated with PTZ to establish temporal lobe epilepsy (TLE) models, whereas the P38 MAPK inhibitor SB 203580 was given to the inhibitor group. Morris water maze test was performed to assay their learning and memory abilities. The levels of phosphorylated p38 (p-p38) and caspase 3 were confirmed using Western blot. RESULTS In the probe test of water maze, the PTZ group had the longest escape latency and least time to pass through the platform. Compared with the PTZ group, the inhibitor group had better performance in escape latency and spatial probe tests. Performance in the water maze test corresponded with the level of p-p38 and caspase 3 in hippocampus. We also found that the down-regulation of p-p38 in the inhibitor group led to down-regulated levels of caspase 3. CONCLUSIONS P38 MAPK pathway contributed to cognitive damage in PTZ-induced epilepsy via apoptosis cascade.
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Giordano C, Costa AM, Lucchi C, Leo G, Brunel L, Fehrentz JA, Martinez J, Torsello A, Biagini G. Progressive Seizure Aggravation in the Repeated 6-Hz Corneal Stimulation Model Is Accompanied by Marked Increase in Hippocampal p-ERK1/2 Immunoreactivity in Neurons. Front Cell Neurosci 2016; 10:281. [PMID: 28018175 PMCID: PMC5159434 DOI: 10.3389/fncel.2016.00281] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/24/2016] [Indexed: 12/13/2022] Open
Abstract
The 6-Hz corneal stimulation test is used to screen novel antiepileptic molecules to overcome the problem of drug refractoriness. Although recognized as a standard test, it has been evaluated only recently in the attempt to characterize the putative neuronal networks involved in seizures caused by corneal stimulation. In particular, by recording from the CA1 region we previously established that the hippocampus participates to propagation of seizure activity. However, these findings were not corroborated by using markers of neuronal activation such as FosB/ΔFosB antigens. In view of this discrepancy, we performed new experiments to characterize the changes in levels of phosphorylated extracellular signal-regulated kinases1/2 (p-ERK1/2), which are also used as markers of neuronal activation. To this aim, mice underwent corneal stimulation up to three different times, in three sessions separated by an interval of 3 days. To characterize a group in which seizures could be prevented by pharmacological treatment, we also considered pretreatment with the ghrelin receptor antagonist EP-80317 (330 μg/kg). Control mice were sham-treated. Video electrocorticographic (ECoG) recordings were obtained from mice belonging to each group of treatment. Animals were finally used to characterize the immunoreactivity for FosB/ΔFosB and p-ERK1/2 in the hippocampus. As previously shown, FosB/ΔFosB levels were highly increased throughout the hippocampus by the first induced seizure but, in spite of the progressively increased seizure severity, they were restored to control levels after the third stimulation. At variance, corneal stimulation caused a progressive increase in p-ERK1/2 immunoreactivity all over the hippocampus, especially in CA1, peaking in the third session. Predictably, EP-80317 administration reduced both duration and severity of seizures, prevented the increase in FosB/ΔFosB levels in the first session, and partially counteracted the increase in p-ERK1/2 levels in the third session. The vast majority of p-ERK1/2 immunopositive cells were co-labeled with FosB/ΔFosB antibodies, suggesting the existence of a relationship between the investigated markers in a subpopulation of neurons activated by seizures. These findings suggest that p-ERK1/2 are useful markers to define the aggravation of seizures and the response to anticonvulsant treatments. In particular, p-ERK1/2 expression clearly identified the involvement of hippocampal regions during seizure aggravation in the 6-Hz model.
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Affiliation(s)
- Carmela Giordano
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Anna M Costa
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Chiara Lucchi
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Giuseppina Leo
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
| | - Luc Brunel
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Jean-Alain Fehrentz
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Jean Martinez
- Max Mousseron Institute of Biomolecules, Centre National de la Recherche Scientifique (CNRS), University of Montpellier, École Nationale Supérieure de Chimie de Montpellier (ENSCM) Montpellier, France
| | - Antonio Torsello
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Giuseppe Biagini
- Laboratory of Experimental Epileptology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSLModena, Italy
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Lopes MW, Leal RB, Guarnieri R, Schwarzbold ML, Hoeller A, Diaz AP, Boos GL, Lin K, Linhares MN, Nunes JC, Quevedo J, Bortolotto ZA, Markowitsch HJ, Lightman SL, Walz R. A single high dose of dexamethasone affects the phosphorylation state of glutamate AMPA receptors in the human limbic system. Transl Psychiatry 2016; 6:e986. [PMID: 27959333 PMCID: PMC5290343 DOI: 10.1038/tp.2016.251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/15/2016] [Indexed: 12/28/2022] Open
Abstract
Glucocorticoids (GC) released during stress response exert feedforward effects in the whole brain, but particularly in the limbic circuits that modulates cognition, emotion and behavior. GC are the most commonly prescribed anti-inflammatory and immunosuppressant medication worldwide and pharmacological GC treatment has been paralleled by the high incidence of acute and chronic neuropsychiatric side effects, which reinforces the brain sensitivity for GC. Synapses can be bi-directionally modifiable via potentiation (long-term potentiation, LTP) or depotentiation (long-term depression, LTD) of synaptic transmission efficacy, and the phosphorylation state of Ser831 and Ser845 sites, in the GluA1 subunit of the glutamate AMPA receptors, are a critical event for these synaptic neuroplasticity events. Through a quasi-randomized controlled study, we show that a single high dexamethasone dose significantly reduces in a dose-dependent manner the levels of GluA1-Ser831 phosphorylation in the amygdala resected during surgery for temporal lobe epilepsy. This is the first report demonstrating GC effects on key markers of synaptic neuroplasticity in the human limbic system. The results contribute to understanding how GC affects the human brain under physiologic and pharmacologic conditions.
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Affiliation(s)
- M W Lopes
- Department of Biochemistry, Federal University of Santa Catarina, Floranópolis, Brazil
| | - R B Leal
- Department of Biochemistry, Federal University of Santa Catarina, Floranópolis, Brazil,Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil
| | - R Guarnieri
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Epilepsy Center of Santa Catarina, Federal University of Santa Catarina, Florianópolis, Brazil,Neurosurgery Unit, Governador Celso Ramos Hospital, Florianópolis, Brazil
| | - M L Schwarzbold
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Department of Internal Medicine, Federal University of Santa Catarina, Florianópolis, Brazil
| | - A Hoeller
- Department of Biochemistry, Federal University of Santa Catarina, Floranópolis, Brazil
| | - A P Diaz
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Department of Internal Medicine, Federal University of Santa Catarina, Florianópolis, Brazil
| | - G L Boos
- Anesthesiology Division, Hospital Governador Celso Ramos, Florianópolis, Brazil
| | - K Lin
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Epilepsy Center of Santa Catarina, Federal University of Santa Catarina, Florianópolis, Brazil,Department of Internal Medicine, Federal University of Santa Catarina, Florianópolis, Brazil
| | - M N Linhares
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Neurosurgery Unit, Governador Celso Ramos Hospital, Florianópolis, Brazil,Department of Surgery, HU, Federal University of Santa Catarina, Florianópolis, Brazil
| | - J C Nunes
- Pathology Division, HU, Federal University of Santa Catarina, Florianópolis, Brazil
| | - J Quevedo
- Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA,Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA,Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| | - Z A Bortolotto
- Laboratory of Neurosciences, Graduate Program in Health Sciences, University of Southern Santa Catarina, Criciúma, Brazil,Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - H J Markowitsch
- Physiological Psychology, University of Bielefeld, Bielefeld, Germany
| | - S L Lightman
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK,Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, Faculty of Medicine and Dentistry, University of Bristol, Bristol, UK
| | - R Walz
- Center for Applied Neuroscience, Hospital Universitário, Federal University of Santa Catarina, Florianópolis, Brazil,Epilepsy Center of Santa Catarina, Federal University of Santa Catarina, Florianópolis, Brazil,Department of Internal Medicine, Federal University of Santa Catarina, Florianópolis, Brazil,Departamento de Clínica Médica, 3 andar, Hospital Universitário, Universidade Federal de Santa Catarina, Florianópolis CEP 88.040-970, Brazil. E-mail:
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Kordi Jaz E, Moghimi A, Fereidoni M, Asadi S, Shamsizadeh A, Roohbakhsh A. SB-334867, an orexin receptor 1 antagonist, decreased seizure and anxiety in pentylenetetrazol-kindled rats. Fundam Clin Pharmacol 2016; 31:201-207. [DOI: 10.1111/fcp.12249] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 09/30/2016] [Accepted: 10/11/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Elham Kordi Jaz
- Department of Biology; Faculty of Sciences; Ferdowsi University of Mashhad; Azadi Sq. Mashhad Iran
| | - Ali Moghimi
- Department of Biology; Faculty of Sciences; Ferdowsi University of Mashhad; Azadi Sq. Mashhad Iran
| | - Masoud Fereidoni
- Department of Biology; Faculty of Sciences; Ferdowsi University of Mashhad; Azadi Sq. Mashhad Iran
| | - Saeedeh Asadi
- Department of Biology; Faculty of Sciences; Ferdowsi University of Mashhad; Azadi Sq. Mashhad Iran
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center and Department of Physiology and Pharmacology; School of Medicine; Rafsanjan University of Medical Sciences; Pistachio Co Street Rafsanjan Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center; Mashhad University of Medical Sciences; Azadi Square Mashhad Iran
- School of Pharmacy; Mashhad University of Medical Sciences; Azadi Square Mashhad Iran
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9
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mTOR and MAPK: from localized translation control to epilepsy. BMC Neurosci 2016; 17:73. [PMID: 27855659 PMCID: PMC5114760 DOI: 10.1186/s12868-016-0308-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/09/2016] [Indexed: 01/03/2023] Open
Abstract
Background Epilepsy is one of the most common neurological diseases characterized by excessive hyperexcitability of neurons. Molecular mechanisms of epilepsy are diverse and not really understood. All in common is the misregulation of proteins that determine excitability such as potassium and sodium channels as well as GABA receptors; which are all known as biomarkers for epilepsy. Two recently identified key pathways involve the kinases mechanistic target of rapamycin (mTOR) and mitogen-activated protein kinases (MAPK). Interestingly, mRNAs coding for those biomarkers are found to be localized at or near synapses indicating a local misregulation of synthesis and activity. Results Research in the last decade indicates that RNA-binding proteins (RBPs) responsible for mRNA localization, stability and translation mediate local expression control. Among others, they are affected by mTOR and MAPK to guide expression of epileptic factors. These results suggest that mTOR/MAPK act on RBPs to regulate the fate of mRNAs, indicating a misregulation of protein expression at synapses in epilepsy. Conclusion We propose that mTOR and MAPK regulate RBPs, thereby guiding the local expression of their target-mRNAs encoding for markers of epilepsy. Thus, misregulated mTOR/MAPK-RBP interplay may result in excessive local synthesis of ion channels and receptors thereby leading to hyperexcitability. Continuous stimulation of synapses further activates mTOR/MAPK pathway reinforcing their effect on RBP-mediated expression control establishing the basis for epilepsy. Here, we highlight findings showing the tight interplay between mTOR as well as MAPK with RBPs to control expression for epileptic biomarkers.
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Gangarossa G, Sakkaki S, Lory P, Valjent E. Mouse hippocampal phosphorylation footprint induced by generalized seizures: Focus on ERK, mTORC1 and Akt/GSK-3 pathways. Neuroscience 2015; 311:474-83. [PMID: 26545981 DOI: 10.1016/j.neuroscience.2015.10.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 02/03/2023]
Abstract
Exacerbated hippocampal activity has been associated to critical modifications of the intracellular signaling pathways. We have investigated rapid hippocampal adaptive responses induced by maximal electroshock seizure (MES). Here, we demonstrate that abnormal and exacerbated hippocampal activity induced by MES triggers specific and temporally distinct patterns of phosphorylation of extracellular signal-related kinase (ERK), mammalian target of rapamycin complex (mTORC) and Akt/glycogen synthase kinase-3 (Akt/GSK-3) pathways in the mouse hippocampus. While the ERK pathway is transiently activated, the mTORC1 cascade follows a rapid inhibition followed by a transient activation. This rebound of mTORC1 activity leads to the selective phosphorylation of p70S6K, which is accompanied by an enhanced phosphorylation of the ribosomal subunit S6. In contrast, the Akt/GSK-3 pathway is weakly altered. Finally, MES triggers a rapid upregulation of several plasticity-associated genes as a consequence exacerbated hippocampal activity. The results reported in the present study are reminiscent of the one observed in other models of generalized seizures, thus defining a common molecular footprint induced by intense and aberrant hippocampal activities.
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Affiliation(s)
- Giuseppe Gangarossa
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France; Inserm U1191, Montpellier F-34094, France; Université de Montpellier, Montpellier F-34094, France.
| | - Sophie Sakkaki
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France; Inserm U1191, Montpellier F-34094, France; Université de Montpellier, Montpellier F-34094, France
| | - Philippe Lory
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France; Inserm U1191, Montpellier F-34094, France; Université de Montpellier, Montpellier F-34094, France; LabEx 'Ion Channel Science and Therapeutics', Montpellier F-34094, France
| | - Emmanuel Valjent
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France; Inserm U1191, Montpellier F-34094, France; Université de Montpellier, Montpellier F-34094, France.
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