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Jiang S, Liu B, Lin K, Li L, Li R, Tan S, Zhang X, Jiang L, Ni H, Wang Y, Ding H, Hu J, Qian H, Ge R. Impacted spike frequency adaptation associated with reduction of KCNQ2/3 exacerbates seizure activity in temporal lobe epilepsy. Hippocampus 2024; 34:58-72. [PMID: 38049972 DOI: 10.1002/hipo.23587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 09/21/2023] [Accepted: 10/28/2023] [Indexed: 12/06/2023]
Abstract
Numerous epilepsy-related genes have been identified in recent decades by unbiased genome-wide screens. However, the available druggable targets for temporal lobe epilepsy (TLE) remain limited. Furthermore, a substantial pool of candidate genes potentially applicable to TLE therapy awaits further validation. In this study, we reveal the significant role of KCNQ2 and KCNQ3, two M-type potassium channel genes, in the onset of seizures in TLE. Our investigation began with a quantitative analysis of two publicly available TLE patient databases to establish a correlation between seizure onset and the downregulated expression of KCNQ2/3. We then replicated these pathological changes in a pilocarpine seizure mouse model and observed a decrease in spike frequency adaptation due to the affected M-currents in dentate gyrus granule neurons. In addition, we performed a small-scale simulation of the dentate gyrus network and confirmed that the impaired spike frequency adaptation of granule cells facilitated epileptiform activity throughout the network. This, in turn, resulted in prolonged seizure duration and reduced interictal intervals. Our findings shed light on an underlying mechanism contributing to ictogenesis in the TLE hippocampus and suggest a promising target for the development of antiepileptic drugs.
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Affiliation(s)
- Shicheng Jiang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Bei Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Kaiwen Lin
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lianjun Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Rongrong Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Shuo Tan
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Xinyu Zhang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lei Jiang
- Department of General Surgery, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China
| | - Hong Ni
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Yuanyuan Wang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Haihu Ding
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
| | - Jing Hu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Hao Qian
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Rongjing Ge
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
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Ali NH, Al-Kuraishy HM, Al-Gareeb AI, Alnaaim SA, Alexiou A, Papadakis M, Saad HM, Batiha GES. Autophagy and autophagy signaling in Epilepsy: possible role of autophagy activator. Mol Med 2023; 29:142. [PMID: 37880579 PMCID: PMC10598971 DOI: 10.1186/s10020-023-00742-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023] Open
Abstract
Autophagy is an explicit cellular process to deliver dissimilar cytoplasmic misfolded proteins, lipids and damaged organelles to the lysosomes for degradation and elimination. The mechanistic target of rapamycin (mTOR) is the main negative regulator of autophagy. The mTOR pathway is involved in regulating neurogenesis, synaptic plasticity, neuronal development and excitability. Exaggerated mTOR activity is associated with the development of temporal lobe epilepsy, genetic and acquired epilepsy, and experimental epilepsy. In particular, mTOR complex 1 (mTORC1) is mainly involved in epileptogenesis. The investigation of autophagy's involvement in epilepsy has recently been conducted, focusing on the critical role of rapamycin, an autophagy inducer, in reducing the severity of induced seizures in animal model studies. The induction of autophagy could be an innovative therapeutic strategy in managing epilepsy. Despite the protective role of autophagy against epileptogenesis and epilepsy, its role in status epilepticus (SE) is perplexing and might be beneficial or detrimental. Therefore, the present review aims to revise the possible role of autophagy in epilepsy.
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Affiliation(s)
- Naif H Ali
- Department of Internal Medicine, Medical College, Najran university, Najran, Saudi Arabia
| | - Hayder M Al-Kuraishy
- Department of Clinical Pharmacology and Medicine, College of Medicine, ALmustansiriyia University, P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Department of Clinical Pharmacology and Medicine, College of Medicine, ALmustansiriyia University, P.O. Box 14132, Baghdad, Iraq
| | - Saud A Alnaaim
- Clinical Neurosciences Department, College of Medicine, King Faisal University, Hofuf, Saudi Arabia
| | - Athanasios Alexiou
- Department of Science and Engineering, Novel Global Community Educational Foundation, Hebersham, NSW, 2770, Australia
- AFNP Med, Wien, 1030, Austria
| | - Marios Papadakis
- Department of Surgery II, University Hospital Witten-Herdecke, University of Witten-Herdecke, Heusnerstrasse 40, 42283, Wuppertal, Germany.
| | - Hebatallah M Saad
- Department of Pathology, Faculty of Veterinary Medicine, Matrouh University, Matrouh, Matrouh, 51744, Egypt.
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, AlBeheira, 22511, Egypt.
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Zhao W, Xie C, Zhang X, Liu J, Liu J, Xia Z. Advances in the mTOR signaling pathway and its inhibitor rapamycin in epilepsy. Brain Behav 2023; 13:e2995. [PMID: 37221133 PMCID: PMC10275542 DOI: 10.1002/brb3.2995] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 03/15/2023] [Accepted: 03/22/2023] [Indexed: 05/25/2023] Open
Abstract
INTRODUCTION Epilepsy is one of the most common and serious brain syndromes and has adverse consequences on a patient's neurobiological, cognitive, psychological, and social wellbeing, thereby threatening their quality of life. Some patients with epilepsy experience poor treatment effects due to the unclear pathophysiological mechanisms of the syndrome. Dysregulation of the mammalian target of the rapamycin (mTOR) pathway is thought to play an important role in the onset and progression of some epilepsies. METHODS This review summarizes the role of the mTOR signaling pathway in the pathogenesis of epilepsy and the prospects for the use of mTOR inhibitors. RESULTS The mTOR pathway functions as a vital mediator in epilepsy development through diverse mechanisms, indicating that the it has great potential as an effective target for epilepsy therapy. The excessive activation of mTOR signaling pathway leads to structural changes in neurons, inhibits autophagy, exacerbates neuron damage, affects mossy fiber sprouting, enhances neuronal excitability, increases neuroinflammation, and is closely associated with tau upregulation in epilepsy. A growing number of studies have demonstrated that mTOR inhibitors exhibit significant antiepileptic effects in both clinical applications and animal models. Specifically, rapamycin, a specific inhibitor of TOR, reduces the intensity and frequency of seizures. Clinical studies in patients with tuberous sclerosis complex have shown that rapamycin has the function of reducing seizures and improving this disease. Everolimus, a chemically modified derivative of rapamycin, has been approved as an added treatment to other antiepileptic medicines. Further explorations are needed to evaluate the therapeutic efficacy and application value of mTOR inhibitors in epilepsy. CONCLUSIONS Targeting the mTOR signaling pathway provides a promising prospect for the treatment of epilepsy.
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Affiliation(s)
- Wei Zhao
- Department of GerontologyThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
| | - Cong Xie
- Department of GerontologyThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
| | - Xu Zhang
- Department of GerontologyThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
| | - Ju Liu
- Laboratory of Microvascular MedicineMedical Research CenterShandong Provincial Qianfoshan Hospital, Shandong UniversityJinanChina
| | - Jinzhi Liu
- Department of GerontologyThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
- Department of NeurologyLiaocheng People's Hospital and Liaocheng Clinical School of Shandong First Medical UniversityLiaochengChina
- Department of GerontologyCheeloo College of MedicineShandong Provincial Qianfoshan Hospital, Shandong UniversityJinanChina
- Department of Geriatric NeurologyThe First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan HospitalJinanChina
| | - Zhangyong Xia
- Department of NeurologyLiaocheng People's Hospital and Liaocheng Clinical School of Shandong First Medical UniversityLiaochengChina
- Department of NeurologyCheeloo College of MedicineLiaocheng People's Hospital, Shandong UniversityJinanChina
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Łukasiuk K, Lasoń W. Emerging Molecular Targets for Anti-Epileptogenic and Epilepsy Modifying Drugs. Int J Mol Sci 2023; 24:ijms24032928. [PMID: 36769250 PMCID: PMC9917847 DOI: 10.3390/ijms24032928] [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: 12/14/2022] [Revised: 01/27/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
The pharmacological treatment of epilepsy is purely symptomatic. Despite many decades of intensive research, causal treatment of this common neurologic disorder is still unavailable. Nevertheless, it is expected that advances in modern neuroscience and molecular biology tools, as well as improved animal models may accelerate designing antiepileptogenic and epilepsy-modifying drugs. Epileptogenesis triggers a vast array of genomic, epigenomic and transcriptomic changes, which ultimately lead to morphological and functional transformation of specific neuronal circuits resulting in the occurrence of spontaneous convulsive or nonconvulsive seizures. Recent decades unraveled molecular processes and biochemical signaling pathways involved in the proepileptic transformation of brain circuits including oxidative stress, apoptosis, neuroinflammatory and neurotrophic factors. The "omics" data derived from both human and animal epileptic tissues, as well as electrophysiological, imaging and neurochemical analysis identified a plethora of possible molecular targets for drugs, which could interfere with various stages of epileptogenetic cascade, including inflammatory processes and neuroplastic changes. In this narrative review, we briefly present contemporary views on the neurobiological background of epileptogenesis and discuss the advantages and disadvantages of some more promising molecular targets for antiepileptogenic pharmacotherapy.
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Affiliation(s)
- Katarzyna Łukasiuk
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Władysław Lasoń
- Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
- Correspondence:
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Impact of Raptor and Rictor Deletion on Hippocampal Pathology Following Status Epilepticus. J Mol Neurosci 2022; 72:1243-1258. [PMID: 35618880 PMCID: PMC9571976 DOI: 10.1007/s12031-022-02030-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
Abstract
Neuronal hyperactivation of the mTOR signaling pathway may play a role in driving the pathological sequelae that follow status epilepticus. Animal studies using pharmacological tools provide support for this hypothesis, however, systemic inhibition of mTOR-a growth pathway active in every mammalian cell-limits conclusions on cell type specificity. To circumvent the limitations of pharmacological approaches, we developed a viral/genetic strategy to delete Raptor or Rictor, inhibiting mTORC1 or mTORC2, respectively, from excitatory hippocampal neurons after status epilepticus in mice. Raptor or Rictor was deleted from roughly 25% of hippocampal granule cells, with variable involvement of other hippocampal neurons, after pilocarpine status epilepticus. Status epilepticus induced the expected loss of hilar neurons, sprouting of granule cell mossy fiber axons and reduced c-Fos activation. Gene deletion did not prevent these changes, although Raptor loss reduced the density of c-Fos-positive granule cells overall relative to Rictor groups. Findings demonstrate that mTOR signaling can be effectively modulated with this approach and further reveal that blocking mTOR signaling in a minority (25%) of granule cells is not sufficient to alter key measures of status epilepticus-induced pathology. The approach is suitable for producing higher deletion rates, and altering the timing of deletion, which may lead to different outcomes.
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Twible C, Abdo R, Zhang Q. Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting. Front Cell Neurosci 2021; 15:725693. [PMID: 34658792 PMCID: PMC8514632 DOI: 10.3389/fncel.2021.725693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.
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Affiliation(s)
- Carolyn Twible
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada
| | - Rober Abdo
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Anatomy and Cell Biology, Western University, London, ON, Canada
| | - Qi Zhang
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Pathology and Lab Medicine, London Health Sciences Centre, University Hospital, London, ON, Canada
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Mazumder AG, Patial V, Singh D. Mycophenolate mofetil contributes to downregulation of the hippocampal interleukin type 2 and 1β mediated PI3K/AKT/mTOR pathway hyperactivation and attenuates neurobehavioral comorbidities in a rat model of temporal lobe epilepsy. Brain Behav Immun 2019; 75:84-93. [PMID: 30243822 DOI: 10.1016/j.bbi.2018.09.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 08/13/2018] [Accepted: 09/19/2018] [Indexed: 12/24/2022] Open
Abstract
The role of neuroinflammatory mediators has been well established in the pathogenesis of temporal lobe epilepsy (TLE) and associated neurobehavioral comorbidities. Mycophenolate mofetil (MMF) is commonly used as an immunosuppressant in organ transplantations. Its neuroprotective effect is well explored in different preclinical and clinical studies. The present study was designed to investigate the effect of MMF in rat model of lithium pilocarpine (LiPc)-induced spontaneous recurrent seizures and its associated neurobehavioral comorbidities. MMF treatment showed a dose-dependent decrease in seizure severity and reduced aggression in epileptic rats. There was marked improvement in spatial and recognition memory functions, along with substantial decrease in depression-like behavior in MMF treated epileptic rats. There was considerable decrease in mossy fiber sprouting in the dentate gyrus and the cornu ammonis 3 regions of the hippocampus, along with reduction in neuronal death in the treated groups. Furthermore, the hippocampal mRNA level of IL-1β, IL-2, PI3K, AKT, HIF-1α, RAPTOR, mTOR, Rps6kb1 and Rps6 was found to be decreased in MMF treated animals. mTOR, S6, pS6 and GFAP protein expression was decreased, whereas NeuN was increased in the rat hippocampus of the treated animals. The results concluded that MMF suppress recurrent seizures, and improves its associated behavioral impairments and cognitive deficit in rat model of TLE. The observed effects of MMF be correlated with the inhibition of IL-2 and IL-1β linked PI3K/AKT/mTOR signaling pathway hyperactivation.
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Affiliation(s)
- 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
| | - Vikram Patial
- 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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8
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Godale CM, Danzer SC. Signaling Pathways and Cellular Mechanisms Regulating Mossy Fiber Sprouting in the Development of Epilepsy. Front Neurol 2018; 9:298. [PMID: 29774009 PMCID: PMC5943493 DOI: 10.3389/fneur.2018.00298] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/17/2018] [Indexed: 02/04/2023] Open
Abstract
The sprouting of hippocampal dentate granule cell axons, termed mossy fibers, into the dentate inner molecular layer is one of the most consistent findings in tissue from patients with mesial temporal lobe epilepsy. Decades of research in animal models have revealed that mossy fiber sprouting creates de novo recurrent excitatory connections in the hippocampus, fueling speculation that the pathology may drive temporal lobe epileptogenesis. Conducting definitive experiments to test this hypothesis, however, has been challenging due to the difficulty of dissociating this sprouting from the many other changes occurring during epileptogenesis. The field has been largely driven, therefore, by correlative data. Recently, the development of powerful transgenic mouse technologies and the discovery of novel drug targets has provided new tools to assess the role of mossy fiber sprouting in epilepsy. We can now selectively manipulate hippocampal granule cells in rodent epilepsy models, providing new insights into the granule cell subpopulations that participate in mossy fiber sprouting. The cellular pathways regulating this sprouting are also coming to light, providing new targets for pharmacological intervention. Surprisingly, many investigators have found that blocking mossy fiber sprouting has no effect on seizure occurrence, while seizure frequency can be reduced by treatments that have no effect on this sprouting. These results raise new questions about the role of mossy fiber sprouting in epilepsy. Here, we will review these findings with particular regard to the contributions of new granule cells to mossy fiber sprouting and the regulation of this sprouting by the mTOR signaling pathway.
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Affiliation(s)
- Christin M Godale
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, United States
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, United States.,Department of Anesthesia, University of Cincinnati, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
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9
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Talos DM, Jacobs LM, Gourmaud S, Coto CA, Sun H, Lim KC, Lucas TH, Davis KA, Martinez-Lage M, Jensen FE. Mechanistic target of rapamycin complex 1 and 2 in human temporal lobe epilepsy. Ann Neurol 2018; 83:311-327. [PMID: 29331082 DOI: 10.1002/ana.25149] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) is a chronic epilepsy syndrome defined by seizures and progressive neurological disabilities, including cognitive impairments, anxiety, and depression. Here, human TLE specimens were investigated focusing on the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) and complex 2 (mTORC2) activities in the brain, given that both pathways may represent unique targets for treatment. METHODS Surgically resected hippocampal and temporal lobe samples from therapy-resistant TLE patients were analyzed by western blotting to quantify the expression of established mTORC1 and mTORC2 activity markers and upstream or downstream signaling pathways involving the two complexes. Histological and immunohistochemical techniques were used to assess hippocampal and neocortical structural abnormalities and cell-specific expression of individual biomarkers. Samples from patients with focal cortical dysplasia (FCD) type II served as positive controls. RESULTS We found significantly increased expression of phospho-mTOR (Ser2448), phospho-S6 (Ser235/236), phospho-S6 (Ser240/244), and phospho-Akt (Ser473) in TLE samples compared to controls, consistent with activation of both mTORC1 and mTORC2. Our work identified the phosphoinositide 3-kinase and Ras/extracellular signal-regulated kinase signaling pathways as potential mTORC1 and mTORC2 upstream activators. In addition, we found that overactive mTORC2 signaling was accompanied by induction of two protein kinase B-dependent prosurvival pathways, as evidenced by increased inhibitory phosphorylation of forkhead box class O3a (Ser253) and glycogen synthase kinase 3 beta (Ser9). INTERPRETATION Our data demonstrate that mTOR signaling is significantly dysregulated in human TLE, offering new targets for pharmacological interventions. Specifically, clinically available drugs that suppress mTORC1 without compromising mTOR2 signaling, such as rapamycin and its analogs, may represent a new group of antiepileptogenic agents in TLE patients. Ann Neurol 2018;83:311-327.
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Affiliation(s)
- Delia M Talos
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Leah M Jacobs
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Sarah Gourmaud
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Carlos A Coto
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Hongyu Sun
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.,Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Kuei-Cheng Lim
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Timothy H Lucas
- Department of Neurosurgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Kathryn A Davis
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Maria Martinez-Lage
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
| | - Frances E Jensen
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA
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Switon K, Kotulska K, Janusz-Kaminska A, Zmorzynska J, Jaworski J. Molecular neurobiology of mTOR. Neuroscience 2017; 341:112-153. [PMID: 27889578 DOI: 10.1016/j.neuroscience.2016.11.017] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 01/17/2023]
Abstract
Mammalian/mechanistic target of rapamycin (mTOR) is a serine-threonine kinase that controls several important aspects of mammalian cell function. mTOR activity is modulated by various intra- and extracellular factors; in turn, mTOR changes rates of translation, transcription, protein degradation, cell signaling, metabolism, and cytoskeleton dynamics. mTOR has been repeatedly shown to participate in neuronal development and the proper functioning of mature neurons. Changes in mTOR activity are often observed in nervous system diseases, including genetic diseases (e.g., tuberous sclerosis complex, Pten-related syndromes, neurofibromatosis, and Fragile X syndrome), epilepsy, brain tumors, and neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, and Huntington's disease). Neuroscientists only recently began deciphering the molecular processes that are downstream of mTOR that participate in proper function of the nervous system. As a result, we are gaining knowledge about the ways in which aberrant changes in mTOR activity lead to various nervous system diseases. In this review, we provide a comprehensive view of mTOR in the nervous system, with a special focus on the neuronal functions of mTOR (e.g., control of translation, transcription, and autophagy) that likely underlie the contribution of mTOR to nervous system diseases.
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Affiliation(s)
- Katarzyna Switon
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Aleja Dzieci Polskich 20, Warsaw 04-730, Poland
| | | | - Justyna Zmorzynska
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland
| | - Jacek Jaworski
- International Institute of Molecular and Cell Biology, 4 Ks. Trojdena Street, Warsaw 02-109, Poland.
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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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Citraro R, Leo A, Constanti A, Russo E, De Sarro G. mTOR pathway inhibition as a new therapeutic strategy in epilepsy and epileptogenesis. Pharmacol Res 2016; 107:333-343. [DOI: 10.1016/j.phrs.2016.03.039] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/23/2016] [Accepted: 03/31/2016] [Indexed: 12/24/2022]
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Impact of rapamycin on status epilepticus induced hippocampal pathology and weight gain. Exp Neurol 2016; 280:1-12. [PMID: 26995324 DOI: 10.1016/j.expneurol.2016.03.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 02/07/2023]
Abstract
Growing evidence implicates the dentate gyrus in temporal lobe epilepsy (TLE). Dentate granule cells limit the amount of excitatory signaling through the hippocampus and exhibit striking neuroplastic changes that may impair this function during epileptogenesis. Furthermore, aberrant integration of newly-generated granule cells underlies the majority of dentate restructuring. Recently, attention has focused on the mammalian target of rapamycin (mTOR) signaling pathway as a potential mediator of epileptogenic change. Systemic administration of the mTOR inhibitor rapamycin has promising therapeutic potential, as it has been shown to reduce seizure frequency and seizure severity in rodent models. Here, we tested whether mTOR signaling facilitates abnormal development of granule cells during epileptogenesis. We also examined dentate inflammation and mossy cell death in the dentate hilus. To determine if mTOR activation is necessary for abnormal granule cell development, transgenic mice that harbored fluorescently-labeled adult-born granule cells were treated with rapamycin following pilocarpine-induced status epilepticus. Systemic rapamycin effectively blocked phosphorylation of S6 protein (a readout of mTOR activity) and reduced granule cell mossy fiber axon sprouting. However, the accumulation of ectopic granule cells and granule cells with aberrant basal dendrites was not significantly reduced. Mossy cell death and reactive astrocytosis were also unaffected. These data suggest that anti-epileptogenic effects of mTOR inhibition may be mediated by mechanisms other than inhibition of these common dentate pathologies. Consistent with this conclusion, rapamycin prevented pathological weight gain in epileptic mice, suggesting that rapamycin might act on central circuits or even peripheral tissues controlling weight gain in epilepsy.
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Drion CM, Borm LE, Kooijman L, Aronica E, Wadman WJ, Hartog AF, van Vliet EA, Gorter JA. Effects of rapamycin and curcumin treatment on the development of epilepsy after electrically induced status epilepticus in rats. Epilepsia 2016; 57:688-97. [DOI: 10.1111/epi.13345] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2016] [Indexed: 01/13/2023]
Affiliation(s)
- Cato M. Drion
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Lars E. Borm
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Lieneke Kooijman
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Eleonora Aronica
- Department (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
- Epilepsy Institute in the Netherlands; Heemstede The Netherlands
| | - Wytse J. Wadman
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Aloysius F. Hartog
- Van‘t Hoff Institute for Molecular Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Erwin A. van Vliet
- Department (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Jan A. Gorter
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
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Nagaraj V, Lee S, Krook-Magnuson E, Soltesz I, Benquet P, Irazoqui P, Netoff T. Future of seizure prediction and intervention: closing the loop. J Clin Neurophysiol 2015; 32:194-206. [PMID: 26035672 PMCID: PMC4455045 DOI: 10.1097/wnp.0000000000000139] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The ultimate goal of epilepsy therapies is to provide seizure control for all patients while eliminating side effects. Improved specificity of intervention through on-demand approaches may overcome many of the limitations of current intervention strategies. This article reviews the progress in seizure prediction and detection, potential new therapies to provide improved specificity, and devices to achieve these ends. Specifically, we discuss (1) potential signal modalities and algorithms for seizure detection and prediction, (2) closed-loop intervention approaches, and (3) hardware for implementing these algorithms and interventions. Seizure prediction and therapies maximize efficacy, whereas minimizing side effects through improved specificity may represent the future of epilepsy treatments.
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Affiliation(s)
- Vivek Nagaraj
- Graduate Program in Neuroscience, University of Minnesota
| | - Steven Lee
- Weldon School of Biomedical Engineering, Purdue University
| | | | - Ivan Soltesz
- Department of Anatomy & Neurobiology, University of California, Irvine
| | | | - Pedro Irazoqui
- Weldon School of Biomedical Engineering, Purdue University
| | - Theoden Netoff
- Graduate Program in Neuroscience, University of Minnesota
- Department of Biomedical Engineering, University of Minnesota
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Shima A, Nitta N, Suzuki F, Laharie AM, Nozaki K, Depaulis A. Activation of mTOR signaling pathway is secondary to neuronal excitability in a mouse model of mesio-temporal lobe epilepsy. Eur J Neurosci 2015; 41:976-88. [DOI: 10.1111/ejn.12835] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/15/2014] [Accepted: 12/17/2014] [Indexed: 01/15/2023]
Affiliation(s)
- Ayako Shima
- Department of Neurosurgery; Shiga University of Medical Science, Seta-Tsukinowa-Cho; Otsu Shiga 520-2192 Japan
- Department of Neurosurgery; Koto Memorial Hospital; Higashioumi Shiga Japan
| | - Naoki Nitta
- Department of Neurosurgery; Shiga University of Medical Science, Seta-Tsukinowa-Cho; Otsu Shiga 520-2192 Japan
- Inserm, U836; Grenoble France
- Grenoble Institut des Neurosciences; University of Grenoble Alpes; Grenoble France
| | - Fumio Suzuki
- Department of Neurosurgery; Koto Memorial Hospital; Higashioumi Shiga Japan
| | - Anne-Marie Laharie
- Inserm, U836; Grenoble France
- Grenoble Institut des Neurosciences; University of Grenoble Alpes; Grenoble France
| | - Kazuhiko Nozaki
- Department of Neurosurgery; Shiga University of Medical Science, Seta-Tsukinowa-Cho; Otsu Shiga 520-2192 Japan
| | - Antoine Depaulis
- Inserm, U836; Grenoble France
- Grenoble Institut des Neurosciences; University of Grenoble Alpes; Grenoble France
- CHU de Grenoble; Hôpital Michallon; Grenoble France
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Yamawaki R, Thind K, Buckmaster PS. Blockade of excitatory synaptogenesis with proximal dendrites of dentate granule cells following rapamycin treatment in a mouse model of temporal lobe epilepsy. J Comp Neurol 2014; 523:281-97. [PMID: 25234294 DOI: 10.1002/cne.23681] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/09/2014] [Accepted: 09/16/2014] [Indexed: 12/13/2022]
Abstract
Inhibiting the mammalian target of rapamycin (mTOR) signaling pathway with rapamycin blocks granule cell axon (mossy fiber) sprouting after epileptogenic injuries, including pilocarpine-induced status epilepticus. However, it remains unclear whether axons from other types of neurons sprout into the inner molecular layer and synapse with granule cell dendrites despite rapamycin treatment. If so, other aberrant positive-feedback networks might develop. To test this possibility stereological electron microscopy was used to estimate the numbers of excitatory synapses in the inner molecular layer per hippocampus in pilocarpine-treated control mice, in mice 5 days after pilocarpine-induced status epilepticus, and after status epilepticus and daily treatment beginning 24 hours later with rapamycin or vehicle for 2 months. The optical fractionator method was used to estimate numbers of granule cells in Nissl-stained sections so that numbers of excitatory synapses in the inner molecular layer per granule cell could be calculated. Control mice had an average of 2,280 asymmetric synapses in the inner molecular layer per granule cell, which was reduced to 63% of controls 5 days after status epilepticus, recovered to 93% of controls in vehicle-treated mice 2 months after status epilepticus, but remained at only 63% of controls in rapamycin-treated mice. These findings reveal that rapamycin prevented excitatory axons from synapsing with proximal dendrites of granule cells and raise questions about the recurrent excitation hypothesis of temporal lobe epilepsy.
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Affiliation(s)
- Ruth Yamawaki
- Department of Comparative Medicine, Stanford University, Stanford, CA, 94305
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Wong M. A critical review of mTOR inhibitors and epilepsy: from basic science to clinical trials. Expert Rev Neurother 2014; 13:657-69. [PMID: 23739003 DOI: 10.1586/ern.13.48] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Present medications for epilepsy have substantial limitations, such as medical intractability in many patients and lack of antiepileptogenic properties to prevent epilepsy. Drugs with novel mechanisms of action are needed to overcome these limitations. The mTOR signaling pathway has emerged as a possible therapeutic target for epilepsy. Preliminary clinical trials suggest that mTOR inhibitors reduce seizures in tuberous sclerosis complex (TSC) patients with intractable epilepsy. Furthermore, mTOR inhibitors have antiepileptogenic properties in preventing epilepsy in animal models of TSC. Besides TSC, accumulating preclinical data suggest that mTOR inhibitors may have antiseizure or antiepileptogenic actions in other types of epilepsy, including infantile spasms, neonatal hypoxic seizures, absence epilepsy and acquired temporal lobe epilepsy following brain injury, but these effects depend on a number of conditions. Future clinical and basic research is needed to establish whether mTOR inhibitors are an effective treatment for epilepsy.
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Affiliation(s)
- Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO 63110, USA.
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PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of post-traumatic epilepsy. J Neurosci 2013; 33:9056-67. [PMID: 23699517 DOI: 10.1523/jneurosci.3870-12.2013] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
mTOR is activated in epilepsy, but the mechanisms of mTOR activation in post-traumatic epileptogenesis are unknown. It is also not clear whether mTOR inhibition has an anti-epileptogenic, or merely anticonvulsive effect. The rat hippocampal organotypic culture model of post-traumatic epilepsy was used to study the effects of long-term (four weeks) inhibition of signaling pathways that interact with mTOR. Ictal activity was quantified by measurement of lactate production and electrical recordings, and cell death was quantified with lactate dehydrogenase (LDH) release measurements and Nissl-stained neuron counts. Lactate and LDH measurements were well correlated with electrographic activity and neuron counts, respectively. Inhibition of PI3K and Akt prevented activation of mTOR, and was as effective as inhibition of mTOR in reducing ictal activity and cell death. A dual inhibitor of PI3K and mTOR, NVP-BEZ235, was also effective. Inhibition of mTOR with rapamycin reduced axon sprouting. Late start of rapamycin treatment was effective in reducing epileptic activity and cell death, while early termination of rapamycin treatment did not result in increased epileptic activity or cell death. The conclusions of the study are as follows: (1) the organotypic hippocampal culture model of post-traumatic epilepsy comprises a rapid assay of anti-epileptogenic and neuroprotective activities and, in this model (2) mTOR activation depends on PI3K-Akt signaling, and (3) transient inhibition of mTOR has sustained effects on epilepsy.
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Heng K, Haney MM, Buckmaster PS. High-dose rapamycin blocks mossy fiber sprouting but not seizures in a mouse model of temporal lobe epilepsy. Epilepsia 2013; 54:1535-41. [PMID: 23848506 DOI: 10.1111/epi.12246] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2013] [Indexed: 11/27/2022]
Abstract
PURPOSE The role of granule cell axon (mossy fiber) sprouting in temporal lobe epileptogenesis is unclear and controversial. Rapamycin suppresses mossy fiber sprouting, but its reported effects on seizure frequency are mixed. The present study used high-dose rapamycin to more completely block mossy fiber sprouting and to measure the effect on seizure frequency. METHODS Mice were treated with pilocarpine to induce status epilepticus. Beginning 24 h later and continuing for 2 months, vehicle or rapamycin (10 mg/kg/day) was administered. Starting 1 month after status epilepticus, mice were monitored by video 9 h per day, every day, for 1 month to measure the frequency of spontaneous motor seizures. At the end of seizure monitoring, a subset of mice was prepared for anatomic analysis. Mossy fiber sprouting was measured as the proportion of the granule cell layer and molecular layer that displayed black labeling in Timm-stained sections. KEY FINDINGS Extensive mossy fiber sprouting developed in mice that experienced status epilepticus and were treated with vehicle. In rapamycin-treated mice, mossy fiber sprouting was blocked almost to the level of naive controls. Seizure frequency was similar in vehicle-treated and rapamycin-treated mice. SIGNIFICANCE These findings suggest that mossy fiber sprouting is not necessary for epileptogenesis in the mouse pilocarpine model. They also reveal that rapamycin does not have antiseizure or antiepileptogenic effects in this model.
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Affiliation(s)
- Kathleen Heng
- Department of Comparative Medicine, Stanford University, Stanford, California 94305-5342, USA
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Meng XF, Yu JT, Song JH, Chi S, Tan L. Role of the mTOR signaling pathway in epilepsy. J Neurol Sci 2013; 332:4-15. [PMID: 23773767 DOI: 10.1016/j.jns.2013.05.029] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 05/19/2013] [Accepted: 05/23/2013] [Indexed: 11/19/2022]
Abstract
Epilepsy, a common neurological disorder and cause of significant morbidity and mortality, places an enormous burden on the individual and society. Presently, most drugs for epilepsy primarily suppress seizures as symptomatic therapies but do not possess actual antiepileptogenic or disease-modifying properties. The mTOR (mammalian target of rapamycin) signaling pathway is involved in major multiple cellular functions, including protein synthesis, cell growth and proliferation and synaptic plasticity, which may influence neuronal excitability and be responsible for epileptogenesis. Intriguing findings of the frequent hyperactivation of mTOR signaling in epilepsy make it a potential mechanism in the pathogenesis as well as an attractive target for the therapeutic intervention, and have driven the significant ongoing efforts to pharmacologically target this pathway. This review explores the relevance of the mTOR pathway to epileptogenesis and its potential as a therapeutic target in epilepsy treatment by presenting the current results on mTOR inhibitors, in particular, rapamycin, in animal models of diverse types of epilepsy. Limited clinical studies in human epilepsy, some paradoxical experimental data and outstanding questions have also been discussed.
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Affiliation(s)
- Xiang-Fei Meng
- Department of Neurology, School of Medicine, Qingdao Municipal Hospital, Qingdao University, China
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Abstract
Current treatments for epilepsy suffer from significant limitations, including medical intractability and lack of disease-modifying or anti-epileptogenic actions. As most current seizure medications modulate ion channels and neurotransmitter receptors, more effective therapies likely need to target completely different mechanisms of action. The mammalian target of rapamycin (mTOR) pathway represents a potential novel therapeutic target for epilepsy. mTOR inhibitors can suppress seizures and prevent epilepsy in animal models of certain genetic epilepsies, such as tuberous sclerosis complex. mTOR inhibitors may also be effective in some models of acquired epilepsy related to brain injury, but these effects are more variable and dependent on a number of factors. Some clinical data suggest that mTOR inhibitors decrease seizures in tuberous sclerosis complex patients, but controlled trials are lacking and no clinical data on potential anti-epileptogenic actions exist. Future basic and clinical research will help to determine the full potential of mTOR inhibitors for epilepsy.
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Affiliation(s)
- Michael Wong
- Department of Neurology & The Hope Center for Neurological Disorders, Washington University School of Medicine, Box 8111, 660 South Euclid Avenue, St Louis, MO 63110, USA, Tel.: +1 314 362 8713, ,
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