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Yuan YG, Wang JL, Zhang YX, Li L, Reza AMMT, Gurunathan S. Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases. Int J Nanomedicine 2023; 18:3177-3210. [PMID: 37337578 PMCID: PMC10276992 DOI: 10.2147/ijn.s407029] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.
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Affiliation(s)
- Yu-Guo Yuan
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
- Jiangsu Co-Innovation Center of Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
| | - Jia-Lin Wang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
- Jiangsu Co-Innovation Center of Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
| | - Ya-Xin Zhang
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
- Jiangsu Co-Innovation Center of Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
| | - Ling Li
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
- Jiangsu Co-Innovation Center of Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, People’s Republic of China
| | - Abu Musa Md Talimur Reza
- Department of Molecular Biology and Genetics, Faculty of Science, Gebze Technical University, Gebze, Kocaeli, Türkiye
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Kraus KL, Nawreen N, Godale CM, Chordia AP, Packard B, LaSarge CL, Herman JP, Danzer SC. Hippocampal glucocorticoid receptors modulate status epilepticus severity. Neurobiol Dis 2023; 178:106014. [PMID: 36702319 PMCID: PMC10055427 DOI: 10.1016/j.nbd.2023.106014] [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: 11/03/2022] [Revised: 01/04/2023] [Accepted: 01/22/2023] [Indexed: 01/24/2023] Open
Abstract
Status epilepticus (SE) is a life-threatening medical emergency with significant morbidity and mortality. SE is associated with a robust and sustained increase in serum glucocorticoids, reaching concentrations sufficient to activate the dense population of glucocorticoid receptors (GRs) expressed among hippocampal excitatory neurons. Glucocorticoid exposure can increase hippocampal neuron excitability; however, whether activation of hippocampal GRs during SE exacerbates seizure severity remains unknown. To test this, a viral strategy was used to delete GRs from a subset of hippocampal excitatory neurons in adult male and female mice, producing hippocampal GR knockdown mice. Two weeks after GR knockdown, mice were challenged with the convulsant drug pilocarpine to induce SE. GR knockdown had opposing effects on early vs late seizure behaviors, with sex influencing responses. For both male and female mice, the onset of mild behavioral seizures was accelerated by GR knockdown. In contrast, GR knockdown delayed the onset of more severe convulsive seizures and death in male mice. Concordantly, GR knockdown also blunted the SE-induced rise in serum corticosterone in male mice. GR knockdown did not alter survival times or serum corticosterone in females. To assess whether loss of GR affected susceptibility to SE-induced cell death, within-animal analyses were conducted comparing local GR knockdown rates to local cell loss. GR knockdown did not affect the degree of localized neuronal loss, suggesting cell-intrinsic GR signaling neither protects nor sensitizes neurons to acute SE-induced death. Overall, the findings reveal that hippocampal GRs exert an anti-convulsant role in both males and females in the early stages of SE, followed by a switch to a pro-convulsive role for males only. Findings reveal an unexpected complexity in the interaction between hippocampal GR activation and the progression of SE.
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Affiliation(s)
- Kimberly L Kraus
- Medical Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
| | - Nawshaba Nawreen
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Pharmacology and Systems Physiology, University of Cincinnati School of Medicine, Cincinnati, OH, United States of America.
| | - Christin M Godale
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
| | - Arihant P Chordia
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America.
| | - Ben Packard
- Department of Pharmacology and Systems Physiology, University of Cincinnati School of Medicine, Cincinnati, OH, United States of America.
| | - Candi L LaSarge
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America; Department of Anesthesiology, University of Cincinnati School of Medicine, Cincinnati, OH, United States of America
| | - James P Herman
- Medical Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Anesthesiology, University of Cincinnati School of Medicine, Cincinnati, OH, United States of America.
| | - Steve C Danzer
- Medical Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America; Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States of America; Department of Anesthesiology, University of Cincinnati School of Medicine, Cincinnati, OH, United States of America.
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Dusing M, LaSarge CL, White A, Jerow LG, Gross C, Danzer SC. Neurovascular Development in Pten and Tsc2 Mouse Mutants. eNeuro 2023; 10:ENEURO.0340-22.2023. [PMID: 36759189 PMCID: PMC9953070 DOI: 10.1523/eneuro.0340-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Hyperactivation of the mechanistic target of rapamycin (mTOR) signaling pathway is linked to more than a dozen neurologic diseases, causing a range of pathologies, including excess neuronal growth, disrupted neuronal migration, cortical dysplasia, epilepsy and autism. The mTOR pathway also regulates angiogenesis. For the present study, therefore, we queried whether loss of Pten or Tsc2, both mTOR negative regulators, alters brain vasculature in three mouse models: one with Pten loss restricted to hippocampal dentate granule cells [DGC-Pten knock-outs (KOs)], a second with widespread Pten loss from excitatory forebrain neurons (FB-Pten KOs) and a third with focal loss of Tsc2 from cortical excitatory neurons (f-Tsc2 KOs). Total hippocampal vessel length and volume per dentate gyrus were dramatically increased in DGC-Pten knock-outs. DGC-Pten knock-outs had larger dentate gyri overall, however, and when normalized to these larger structures, vessel density was preserved. In addition, tests of blood-brain barrier integrity did not reveal increased permeability. FB-Pten KOs recapitulated the findings in the more restricted DGC-Pten KOs, with increased vessel area, but preserved vessel density. FB-Pten KOs did, however, exhibit elevated levels of the angiogenic factor VegfA. In contrast to findings with Pten, focal loss of Tsc2 from cortical excitatory neurons produced a localized increase in vessel density. Together, these studies demonstrate that hypervascularization is not a consistent feature of mTOR hyperactivation models and suggest that loss of different mTOR pathway regulatory genes exert distinct effects on angiogenesis.
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Affiliation(s)
- Mary Dusing
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Candi L LaSarge
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Angela White
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Lilian G Jerow
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Christina Gross
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
| | - Steve C Danzer
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
- Departments of Anesthesia and Pediatrics, University of Cincinnati, Cincinnati, OH 45229
- Center for Pediatric Neuroscience, Cincinnati Children's Hospital, Cincinnati, OH 45229
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH 45219
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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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Ma KG, Hu HB, Zhou JS, Ji C, Yan QS, Peng SM, Ren LD, Yang BN, Xiao XL, Ma YB, Wu F, Si KW, Wu XL, Liu JX. Neuronal Glypican4 promotes mossy fiber sprouting through the mTOR pathway after pilocarpine-induced status epilepticus in mice. Exp Neurol 2021; 347:113918. [PMID: 34748756 DOI: 10.1016/j.expneurol.2021.113918] [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: 05/11/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 02/07/2023]
Abstract
In temporal lobe epilepsy (TLE), abnormal axon guidance and synapse formation lead to sprouting of mossy fibers in the hippocampus, which is one of the most consistent pathological findings in patients and animal models with TLE. Glypican 4 (Gpc4) belongs to the heparan sulfate proteoglycan family, which play an important role in axon guidance and excitatory synapse formation. However, the role of Gpc4 in the development of mossy fibers sprouting (MFS) and its underlying mechanism remain unknown. Using a pilocarpine-induced mice model of epilepsy, we showed that Gpc4 expression was significantly increased in the stratum granulosum of the dentate gyrus at 1 week after status epilepticus (SE). Using Gpc4 overexpression or Gpc4 shRNA lentivirus to regulate the Gpc4 level in the dentate gyrus, increased or decreased levels of netrin-1, SynI, PSD-95, and Timm score were observed in the dentate gyrus, indicating a crucial role of Gpc4 in modulating the development of functional MFS. The observed effects of Gpc4 on MFS were significantly antagonized when mice were treated with L-leucine or rapamycin, an agonist or antagonist of the mammalian target of rapamycin (mTOR) signal, respectively, demonstrating that mTOR pathway is an essential requirement for Gpc4-regulated MFS. Additionally, the attenuated spontaneous recurrent seizures (SRSs) were observed during chronic stage of the disease by suppressing the Gpc4 expression after SE. Altogether, our findings demonstrate a novel control of neuronal Gpc4 on the development of MFS through the mTOR pathway after pilocarpine-induced SE. Our results also strongly suggest that Gpc4 may serve as a promising target for antiepileptic studies.
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Affiliation(s)
- Kai-Ge Ma
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Hai-Bo Hu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Jin-Song Zhou
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Chao Ji
- Qide College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Qi-Sheng Yan
- Qide College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Si-Ming Peng
- Zonglian College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Lan-Dong Ren
- Zonglian College, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Bing-Nan Yang
- Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Xin-Li Xiao
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Yan-Bing Ma
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Feng Wu
- Center of Teaching and Experiment for Medical Post Graduates, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Kai-Wei Si
- Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China
| | - Xiao-Lin Wu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China.
| | - Jian-Xin Liu
- Institute of Neurobiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China; Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, 76 West Yanta Road, Xi'an 710061, China.
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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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Upadhya D, Shetty AK. Promise of extracellular vesicles for diagnosis and treatment of epilepsy. Epilepsy Behav 2021; 121:106499. [PMID: 31636006 PMCID: PMC7165061 DOI: 10.1016/j.yebeh.2019.106499] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 01/08/2023]
Abstract
Extracellular vesicles (EVs) released from cells play vital roles in intercellular communication. Moreover, EVs released from stem cells have therapeutic properties. This review confers the potential of brain-derived EVs in the cerebrospinal fluid (CSF) and the serum as sources of epilepsy-related biomarkers, and the promise of mesenchymal stem cell (MSC)-derived EVs for easing status epilepticus (SE)-induced adverse changes in the brain. Extracellular vesicles shed from neurons and glia in the brain can also be found in the circulating blood as EVs cross the blood-brain barrier (BBB). Evaluation of neuron and/or glia-derived EVs in the blood of patients who have epilepsy could help in identifying specific biomarkers for distinct types of epilepsies. Such a liquid biopsy approach is also amenable for repeated analysis in clinical trials for comprehending treatment efficacy, disease progression, and mechanisms of therapeutic interventions. Extracellular vesicle biomarker studies in animal prototypes of epilepsy, in addition, could help in identifying specific micro ribonucleic acid (miRNAs) contributing to epileptogenesis, seizures, or cognitive dysfunction in different types of epilepsy. Furthermore, intranasal (IN) administration of MSC-derived EVs after SE has shown efficacy for restraining SE-induced neuroinflammation, aberrant neurogenesis, and cognitive dysfunction in an animal prototype. Clinical translation of EV therapy as an adjunct to antiepileptic drugs appears attractive to counteract the progression of SE-induced epileptogenic changes, as the risk for thrombosis or tumor is minimal with nanosized EVs. Also, EVs can be engineered to deliver specific miRNAs, proteins, or antiepileptic drugs to the brain since they incorporate into neurons and glia throughout the brain after IN administration. This article is part of the Special Issue "NEWroscience 2018".
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Affiliation(s)
- Dinesh Upadhya
- Centre for Molecular Neurosciences, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Ashok K. Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, Texas, USA
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Buckinx A, Pierre A, Van Den Herrewegen Y, Guenther E, Gerlach M, Van Laethem G, Kooijman R, De Bundel D, Smolders I. Translational potential of the ghrelin receptor agonist macimorelin for seizure suppression in pharmacoresistant epilepsy. Eur J Neurol 2021; 28:3100-3112. [PMID: 34157194 DOI: 10.1111/ene.14992] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/07/2021] [Accepted: 06/14/2021] [Indexed: 01/26/2023]
Abstract
BACKGROUND Current drugs for epilepsy affect seizures, but no antiepileptogenic or disease-modifying drugs are available that prevent or slow down epileptogenesis, which is characterized by neuronal cell loss, inflammation and aberrant network formation. Ghrelin and ghrelin receptor (ghrelin-R) agonists were previously found to exert anticonvulsant, neuroprotective and anti-inflammatory effects in seizure models and immediately after status epilepticus (SE). Therefore, the aim of this study was to assess whether the ghrelin-R agonist macimorelin is antiepileptogenic in the pharmacoresistant intrahippocampal kainic acid (IHKA) mouse model. METHODS SE was induced in C57BL/6 mice by unilateral IHKA injection. Starting 24 h after SE, mice were treated intraperitoneally with macimorelin (5 mg/kg) or saline twice daily for 2 weeks, followed by a 2-week wash-out. Mice were continuously electroencephalogram-monitored, and at the end of the experiment neuroprotection and gliosis were assessed. RESULTS Macimorelin significantly decreased the number and duration of seizures during the treatment period, but had no antiepileptogenic or disease-modifying effect in this dose regimen. While macimorelin did not significantly affect food intake or body weight over a 2-week treatment period, its acute orexigenic effect was preserved in epileptic mice but not in sham mice. CONCLUSIONS While the full ghrelin-R agonist macimorelin was not significantly antiepileptogenic nor disease-modifying, this is the first study to demonstrate its anticonvulsant effects in the IHKA model of drug-refractory temporal lobe epilepsy. These findings highlight the potential use of macimorelin as a novel treatment option for seizure suppression in pharmacoresistant epilepsy.
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Affiliation(s)
- An Buckinx
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Anouk Pierre
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Yana Van Den Herrewegen
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | | | | | - Gaetan Van Laethem
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Ron Kooijman
- Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Dimitri De Bundel
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Ilse Smolders
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Brussels, Belgium
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Wulsin AC, Kraus KL, Gaitonde KD, Suru V, Arafa SR, Packard BA, Herman JP, Danzer SC. The glucocorticoid receptor specific modulator CORT108297 reduces brain pathology following status epilepticus. Exp Neurol 2021; 341:113703. [PMID: 33745919 PMCID: PMC8169587 DOI: 10.1016/j.expneurol.2021.113703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/05/2021] [Accepted: 03/15/2021] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Glucocorticoid levels rise rapidly following status epilepticus and remain elevated for weeks after the injury. To determine whether glucocorticoid receptor activation contributes to the pathological sequelae of status epilepticus, mice were treated with a novel glucocorticoid receptor modulator, C108297. METHODS Mice were treated with either C108297 or vehicle for 10 days beginning one day after pilocarpine-induced status epilepticus. Baseline and stress-induced glucocorticoid secretion were assessed to determine whether hypothalamic-pituitary-adrenal axis hyperreactivity could be controlled. Status epilepticus-induced pathology was assessed by quantifying ectopic hippocampal granule cell density, microglial density, astrocyte density and mossy cell loss. Neuronal network function was examined indirectly by determining the density of Fos immunoreactive neurons following restraint stress. RESULTS Treatment with C108297 attenuated corticosterone hypersecretion after status epilepticus. Treatment also decreased the density of hilar ectopic granule cells and reduced microglial proliferation. Mossy cell loss, on the other hand, was not prevented in treated mice. C108297 altered the cellular distribution of Fos protein but did not restore the normal pattern of expression. INTERPRETATION Results demonstrate that baseline corticosterone levels can be normalized with C108297, and implicate glucocorticoid signaling in the development of structural changes following status epilepticus. These findings support the further development of glucocorticoid receptor modulators as novel therapeutics for the prevention of brain pathology following status epilepticus.
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Affiliation(s)
- Aynara C Wulsin
- Cincinnati Children's Hospital Medical Center, Department of Anesthesia, USA; Cincinnati Children's Hospital Medical Center, Department of Pediatrics, USA; University of Cincinnati, Medical Scientist Training Program, USA; University of Cincinnati, Neuroscience Graduate Program, USA
| | - Kimberly L Kraus
- Cincinnati Children's Hospital Medical Center, Department of Anesthesia, USA; University of Cincinnati, Medical Scientist Training Program, USA; University of Cincinnati, Neuroscience Graduate Program, USA
| | - Kevin D Gaitonde
- University of Cincinnati, Medical Scientist Training Program, USA
| | - Venkat Suru
- Cincinnati Children's Hospital Medical Center, Department of Anesthesia, USA
| | - Salwa R Arafa
- Cincinnati Children's Hospital Medical Center, Department of Anesthesia, USA
| | - Benjamin A Packard
- University of Cincinnati, Department of Pharmacology & Systems Physiology
| | - James P Herman
- University of Cincinnati, Department of Pharmacology & Systems Physiology
| | - Steve C Danzer
- Cincinnati Children's Hospital Medical Center, Department of Anesthesia, USA; Cincinnati Children's Hospital Medical Center, Department of Pediatrics, USA; University of Cincinnati, Medical Scientist Training Program, USA; University of Cincinnati, Neuroscience Graduate Program, USA.
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Littlejohn EL, DeSana AJ, Williams HC, Chapman RT, Joseph B, Juras JA, Saatman KE. IGF1-Stimulated Posttraumatic Hippocampal Remodeling Is Not Dependent on mTOR. Front Cell Dev Biol 2021; 9:663456. [PMID: 34095131 PMCID: PMC8174097 DOI: 10.3389/fcell.2021.663456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/26/2021] [Indexed: 01/29/2023] Open
Abstract
Adult hippocampal neurogenesis is stimulated acutely following traumatic brain injury (TBI). However, many hippocampal neurons born after injury develop abnormally and the number that survive long-term is debated. In experimental TBI, insulin-like growth factor-1 (IGF1) promotes hippocampal neuronal differentiation, improves immature neuron dendritic arbor morphology, increases long-term survival of neurons born after TBI, and improves cognitive function. One potential downstream mediator of the neurogenic effects of IGF1 is mammalian target of rapamycin (mTOR), which regulates proliferation as well as axonal and dendritic growth in the CNS. Excessive mTOR activation is posited to contribute to aberrant plasticity related to posttraumatic epilepsy, spurring preclinical studies of mTOR inhibitors as therapeutics for TBI. The degree to which pro-neurogenic effects of IGF1 depend upon upregulation of mTOR activity is currently unknown. Using immunostaining for phosphorylated ribosomal protein S6, a commonly used surrogate for mTOR activation, we show that controlled cortical impact TBI triggers mTOR activation in the dentate gyrus in a time-, region-, and injury severity-dependent manner. Posttraumatic mTOR activation in the granule cell layer (GCL) and dentate hilus was amplified in mice with conditional overexpression of IGF1. In contrast, delayed astrocytic activation of mTOR signaling within the dentate gyrus molecular layer, closely associated with proliferation, was not affected by IGF1 overexpression. To determine whether mTOR activation is necessary for IGF1-mediated stimulation of posttraumatic hippocampal neurogenesis, wildtype and IGF1 transgenic mice received the mTOR inhibitor rapamycin daily beginning at 3 days after TBI, following pulse labeling with bromodeoxyuridine. Compared to wildtype mice, IGF1 overexpressing mice exhibited increased posttraumatic neurogenesis, with a higher density of posttrauma-born GCL neurons at 10 days after injury. Inhibition of mTOR did not abrogate IGF1-stimulated enhancement of posttraumatic neurogenesis. Rather, rapamycin treatment in IGF1 transgenic mice, but not in WT mice, increased numbers of cells labeled with BrdU at 3 days after injury that survived to 10 days, and enhanced the proportion of posttrauma-born cells that differentiated into neurons. Because beneficial effects of IGF1 on hippocampal neurogenesis were maintained or even enhanced with delayed inhibition of mTOR, combination therapy approaches may hold promise for TBI.
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Affiliation(s)
| | | | | | | | | | | | - Kathryn E. Saatman
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
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Singh T, Goel RK. Epilepsy Associated Depression: An Update on Current Scenario, Suggested Mechanisms, and Opportunities. Neurochem Res 2021; 46:1305-1321. [PMID: 33665775 DOI: 10.1007/s11064-021-03274-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/07/2021] [Accepted: 02/10/2021] [Indexed: 12/21/2022]
Abstract
Depression is one of the most frequent psychiatric comorbidities associated with epilepsy having a major impact on the patient's quality of life. Several screening tools are available to identify and follow up psychiatric disorders in epilepsy. Out of various psychiatric disorders, people with epilepsy (PWE) are at greater risk of developing depression. This bidirectional relationship further hinders pharmacotherapy of comorbid depression in PWE as some antiepileptic drugs (AEDs) worsen associated depression and coadministration of existing antidepressants (ADs) to alleviate comorbid depression has been reported to worsen seizures. Selective serotonin reuptake inhibitors (SSRIs) and selective serotonin and norepinephrine reuptake inhibitors (SNRIs) are first choice of ADs and are considered safe in PWE, but there are no high-quality evidences. Similar to observations in people with depression, PWE also showed pharmacoresistant to available SSRI/SNRIs, which further complicates the disease prognosis. Randomized double-blind placebo-controlled clinical trials are necessary to report efficacy and safety of available ADs in PWE. We should also move beyond ADs, and therefore, we reviewed common pathological mechanisms such as neuroinflammation, dysregulated hypothalamus pituitary adrenal (HPA) axis, altered neurogenesis, and altered tryptophan metabolism responsible for coexistent relationship of epilepsy and depression. Based on these common pertinent pathways involved in the genesis of epilepsy and depression, we suggested novel targets and therapeutic approaches for safe management of comorbid depression in epilepsy.
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Affiliation(s)
- Tanveer Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, 147002, India
| | - Rajesh Kumar Goel
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, 147002, India.
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12
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de Melo IS, Pacheco ALD, Dos Santos YMO, Figueiredo LM, Nicacio DCSP, Cardoso-Sousa L, Duzzioni M, Gitaí DLG, Tilelli CQ, Sabino-Silva R, de Castro OW. Modulation of Glucose Availability and Effects of Hypo- and Hyperglycemia on Status Epilepticus: What We Do Not Know Yet? Mol Neurobiol 2020; 58:505-519. [PMID: 32975651 DOI: 10.1007/s12035-020-02133-8] [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: 08/03/2020] [Accepted: 09/14/2020] [Indexed: 12/22/2022]
Abstract
Status epilepticus (SE) can lead to serious neuronal damage and act as an initial trigger for epileptogenic processes that may lead to temporal lobe epilepsy (TLE). Besides promoting neurodegeneration, neuroinflammation, and abnormal neurogenesis, SE can generate an extensive hypometabolism in several brain areas and, consequently, reduce intracellular energy supply, such as adenosine triphosphate (ATP) molecules. Although some antiepileptic drugs show efficiency to terminate or reduce epileptic seizures, approximately 30% of TLE patients are refractory to regular antiepileptic drugs (AEDs). Modulation of glucose availability may provide a novel and robust alternative for treating seizures and neuronal damage that occurs during epileptogenesis; however, more detailed information remains unknown, especially under hypo- and hyperglycemic conditions. Here, we review several pathways of glucose metabolism activated during and after SE, as well as the effects of hypo- and hyperglycemia in the generation of self-sustained limbic seizures. Furthermore, this study suggests the control of glucose availability as a potential therapeutic tool for SE.
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Affiliation(s)
- Igor Santana de Melo
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Amanda Larissa Dias Pacheco
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Yngrid Mickaelli Oliveira Dos Santos
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Laura Mello Figueiredo
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Dannyele Cynthia Santos Pimentel Nicacio
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Leia Cardoso-Sousa
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia (UFU), ARFIS, Av. Pará, 1720, Campus Umuruama, Uberlandia, MG, CEP 38400-902, Brazil
| | - Marcelo Duzzioni
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Daniel Leite Góes Gitaí
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil
| | - Cristiane Queixa Tilelli
- Physiology Laboratory, Federal University of Sao Joao del Rei (UFSJ), Central-West Campus, Divinopolis, MG, Brazil
| | - Robinson Sabino-Silva
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia (UFU), ARFIS, Av. Pará, 1720, Campus Umuruama, Uberlandia, MG, CEP 38400-902, Brazil.
| | - Olagide Wagner de Castro
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Av. Lourival de Melo Mota, km 14, Campus A. C. Simões, Cidade Universitária, Maceió, AL, CEP 57072-970, Brazil.
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13
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Cho S, Park E, Telliyan T, Baker A, Reid AY. Zebrafish model of posttraumatic epilepsy. Epilepsia 2020; 61:1774-1785. [DOI: 10.1111/epi.16589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 06/02/2020] [Accepted: 06/02/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Sung‐Joon Cho
- Division of Fundamental Neurobiology Krembil Research Institute University Health Network Toronto Ontario Canada
- Collaborative Program in Neuroscience University of Toronto Toronto Ontario Canada
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Eugene Park
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Tamar Telliyan
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
| | - Andrew Baker
- Keenan Research Centre Li Ka Shing Knowledge Institute St. Michael's Hospital Toronto Ontario Canada
- Department of Anesthesia and Surgery University of Toronto Toronto Ontario Canada
| | - Aylin Y. Reid
- Division of Fundamental Neurobiology Krembil Research Institute University Health Network Toronto Ontario Canada
- Department of Medicine University of Toronto Toronto Ontario Canada
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Casillas‐Espinosa PM, Ali I, O'Brien TJ. Neurodegenerative pathways as targets for acquired epilepsy therapy development. Epilepsia Open 2020; 5:138-154. [PMID: 32524040 PMCID: PMC7278567 DOI: 10.1002/epi4.12386] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 12/16/2022] Open
Abstract
There is a growing body of clinical and experimental evidence that neurodegenerative diseases and epileptogenesis after an acquired brain insult may share common etiological mechanisms. Acquired epilepsy commonly develops as a comorbid condition in patients with neurodegenerative diseases such as Alzheimer's disease, although it is likely much under diagnosed in practice. Progressive neurodegeneration has also been described after traumatic brain injury, stroke, and other forms of brain insults. Moreover, recent evidence has shown that acquired epilepsy is often a progressive disorder that is associated with the development of drug resistance, cognitive decline, and worsening of other neuropsychiatric comorbidities. Therefore, new pharmacological therapies that target neurobiological pathways that underpin neurodegenerative diseases have potential to have both an anti-epileptogenic and disease-modifying effect on the seizures in patients with acquired epilepsy, and also mitigate the progressive neurocognitive and neuropsychiatric comorbidities. Here, we review the neurodegenerative pathways that are plausible targets for the development of novel therapies that could prevent the development or modify the progression of acquired epilepsy, and the supporting published experimental and clinical evidence.
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Affiliation(s)
- Pablo M. Casillas‐Espinosa
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Idrish Ali
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Terence J. O'Brien
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
- Department of NeurologyThe Alfred HospitalMelbourneVic.Australia
- Department of NeurologyThe Royal Melbourne HospitalParkvilleVic.Australia
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15
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LncRNA CASC2 inhibits astrocytic activation and adenosine metabolism by regulating PTEN in pentylenetetrazol-induced epilepsy model. J Chem Neuroanat 2020; 105:101749. [PMID: 31958564 DOI: 10.1016/j.jchemneu.2020.101749] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 12/12/2022]
Abstract
Growing evidence has indicated that long noncoding RNAs (lncRNAs) are closely implicated in the progress of epilepsy. However, the expression profile and potential function of long noncoding RNAs cancer susceptibility candidate 2 (lncRNA CASC2) in epilepsy are poorly studied. The aim of this study was to testify the influence of lncRNA CASC2 on epilepsy in rat and cell models of epileptic seizure. We adopted qRT-PCR on the hippocampus of rats following pentylenetetrazol (PTZ)-stimulated epilepsy. To further examine the correlation between lncRNA CASC2 and Phosphatase and tensin homolog (PTEN), we detected the effects of lncRNA CASC2 on PTEN expression. We found that lncRNA CASC2 and PTEN expression were positively correlated in PTZ-induced epileptic rat. Overexpression of lncRNA CASC2 prolonged the latency and reduced the frequency of epileptic seizure, suppressed the activation of astrocytes and the release of adenosine in epileptic rat, whereas downregulation of lncRNA CASC2 exhibited the opposite effects. Meanwhile, lncRNA CASC2 decreased the adenosine metabolism related proteins expression of p38, Equilibrative nucleoside transporter 1 (ENT1) and Adenosine Kinase (ADK). In PTZ-treated astrocytes, PTEN was found to be a direct target of lncRNA CASC2. Additionally, downregulation of PTEN attenuated the protective effect of lncRNA CASC2 overexpression in epileptic seizure. Our findings manifested the key role of lncRNA CASC2 in the occurrence of epilepsy by targeting PTEN, which provided a novel target for epilepsy therapy.
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16
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Chang CC, Chuang CL, Hsin IF, Hsu SJ, Huang HC, Lee FY, Lee SD. A high-dose rapamycin treatment alleviates hepatopulmonary syndrome in cirrhotic rats. J Chin Med Assoc 2020; 83:32-40. [PMID: 31567652 DOI: 10.1097/jcma.0000000000000194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Rapamycin is a type of immunosuppressive agent that acts through inhibition of mammalian target of rapamycin (mTOR). Hepatopulmonary syndrome (HPS) is a lethal complication in cirrhotic patients. It is characterized by hypoxia and increased intrapulmonary shunts, in which pulmonary inflammation and angiogenesis play important roles. The current study aimed to evaluate the effect of rapamycin on HPS using the experimental model of common bile duct ligation (CBDL)-induced cirrhosis in rats. METHODS The rats received low-dose (0.5 mg/kg), high-dose (2 mg/kg) rapamycin, or vehicle from the 15th to the 28th day post CBDL. Then the mortality rate, hemodynamics, biochemistry parameters, arterial blood gas and plasma levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF)-α were evaluated on the 28th day post CBDL. Pulmonary histopathological stains were performed, and protein expression was examined. In parallel groups, the intrapulmonary shunts of CBDL rats were measured. RESULTS Compared with the control, a high-dose rapamycin treatment decreased portal pressure and improved hypoxia in CBDL rats. It also reduced the plasma level of VEGF and TNF-α and decreased intrapulmonary shunts. Meanwhile, it ameliorated pulmonary inflammation and angiogenesis and downregulated the protein expression of mTOR, P70S6K, nuclear factor kappa B (NFκB), VEGF, and VEGF receptor 2. In contrast, low-dose rapamycin did not attenuate intrapulmonary shunts despite ameliorating portal hypertension. CONCLUSION High-dose rapamycin ameliorates HPS in cirrhotic rats as evidenced by the alleviated hypoxia and decreased intrapulmonary shunts. Downregulation of the mTOR/P70S6K, NFκB, and VEGF signaling pathways might play a key role.
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Affiliation(s)
- Ching-Chih Chang
- Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
| | - Chiao-Lin Chuang
- Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
| | - I-Fang Hsin
- Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
- Endoscopy Center for Diagnosis and Treatment, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
| | - Shao-Jung Hsu
- Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
| | - Hui-Chun Huang
- Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
| | - Fa-Yauh Lee
- Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
| | - Shou-Dong Lee
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC
- Cheng-Hsin General Hospital, Taipei, Taiwan, ROC
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17
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Rivell A, Mattson MP. Intergenerational Metabolic Syndrome and Neuronal Network Hyperexcitability in Autism. Trends Neurosci 2019; 42:709-726. [PMID: 31495451 PMCID: PMC6779523 DOI: 10.1016/j.tins.2019.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/17/2019] [Accepted: 08/06/2019] [Indexed: 12/13/2022]
Abstract
We review evidence that suggests a role for excessive consumption of energy-dense foods, particularly fructose, and consequent obesity and insulin resistance (metabolic syndrome) in the recent increase in prevalence of autism spectrum disorders (ASD). Maternal insulin resistance, obesity, and diabetes may predispose offspring to ASD by mechanisms involving chronic activation of anabolic cellular pathways and a lack of metabolic switching to ketosis resulting in a deficit in GABAergic signaling and neuronal network hyperexcitability. Metabolic reprogramming by epigenetic DNA and chromatin modifications may contribute to alterations in gene expression that result in ASD. These mechanistic insights suggest that interventions that improve metabolic health such as intermittent fasting and exercise may ameliorate developmental neuronal network abnormalities and consequent behavioral manifestations in ASD.
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Affiliation(s)
- Aileen Rivell
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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18
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Cao Q, Liu X, Yang F, Wang H. CB2R induces a protective response for epileptic seizure via the PI3K 110α-AKT signaling pathway. Exp Ther Med 2018; 16:4784-4790. [PMID: 30542433 DOI: 10.3892/etm.2018.6788] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 05/11/2018] [Indexed: 01/29/2023] Open
Abstract
Epilepsy is a chronic brain disease caused by abnormal discharging in the brain, which induces momentary brain dysfunction. Cannabinoid 2 receptor (CB2R) is expressed in central nervous system (CNS) and serves an important role in the pathogenesis of CNS diseases. The aim of the present study was to explore the effects of CB2R activation on phosphoinositide 3-kinase (PI3K) 110α-protein kinase B (AKT) signaling in an astrocyte model of epilepsy. Rat CTX TNA2 astrocytes were treated with Mg free solution to establish a cell model of epilepsy and were subsequently treated with a CB2R agonist (JWH133) and antagonist (AM630). Cell cycle analysis revealed that treatment using Mg free solution inhibited cell cycle transition. JWH133 facilitated cell cycle progression while AM630 inhibited it. Western blotting results demonstrated that treatment with Mg free solution downregulated the expression of cyclin D1, cyclin E, phosphorylated Retinoblastoma (p-Rb), B-cell lymphoma 2 (Bcl-2), PI3K 110α, p-AKT and p-mammalian target of rapamycin, whereas JWH133 treatment upregulated these proteins. AM630 ameliorated the JWH133-induced upregulation of these proteins. To confirm the involvement of AKT signaling, the AKT inhibitor wortmannin was used. The results revealed that wortmannin inhibited the effect of JWH133 on p-AKT, cyclin D1, p-Rb and Bcl-2 expression. In addition, the effects of JWH133 and AM630 on PI3K 110α-AKT signaling were verified using a rat model of epilepsy. In conclusion, the present study demonstrates that CB2R activation induces astrocyte proliferation and survival via activation of the PI3K 110α-AKT signaling pathway.
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Affiliation(s)
- Qingjun Cao
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Xueyan Liu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Fenghua Yang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Hua Wang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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19
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Wulsin AC, Franco-Villanueva A, Romancheck C, Morano RL, Smith BL, Packard BA, Danzer SC, Herman JP. Functional disruption of stress modulatory circuits in a model of temporal lobe epilepsy. PLoS One 2018; 13:e0197955. [PMID: 29795651 PMCID: PMC5993058 DOI: 10.1371/journal.pone.0197955] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 05/13/2018] [Indexed: 12/15/2022] Open
Abstract
Clinical data suggest that the neuroendocrine stress response is chronically dysregulated in a subset of patients with temporal lobe epilepsy (TLE), potentially contributing to both disease progression and the development of psychiatric comorbidities such as anxiety and depression. Whether neuroendocrine dysregulation and psychiatric comorbidities reflect direct effects of epilepsy-related pathologies, or secondary effects of disease burden particular to humans with epilepsy (i.e. social estrangement, employment changes) is not clear. Animal models provide an opportunity to dissociate these factors. Therefore, we queried whether epileptic mice would reproduce neuroendocrine and behavioral changes associated with human epilepsy. Male FVB mice were exposed to pilocarpine to induce status epilepticus (SE) and the subsequent development of spontaneous recurrent seizures. Morning baseline corticosterone levels were elevated in pilocarpine treated mice at 1, 7 and 10 weeks post-SE relative to controls. Similarly, epileptic mice had increased adrenal weight when compared to control mice. Exposure to acute restraint stress resulted in hypersecretion of corticosterone 30 min after the onset of the challenge. Anatomical analyses revealed reduced Fos expression in infralimbic and prelimbic prefrontal cortex, ventral subiculum and basal amygdala following restraint. No differences in Fos immunoreactivity were found in the paraventricular nucleus of the hypothalamus, hippocampal subfields or central amygdala. In order to assess emotional behavior, a second cohort of mice underwent a battery of behavioral tests, including sucrose preference, open field, elevated plus maze, 24h home-cage monitoring and forced swim. Epileptic mice showed increased anhedonic behavior, hyperactivity and anxiety-like behaviors. Together these data demonstrate that epileptic mice develop HPA axis hyperactivity and exhibit behavioral dysfunction. Endocrine and behavioral changes are associated with impaired recruitment of forebrain circuits regulating stress inhibition and emotional reactivity. Loss of forebrain control may underlie pronounced endocrine dysfunction and comorbid psychopathologies seen in temporal lobe epilepsy.
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Affiliation(s)
- Aynara C. Wulsin
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
- Department of Anesthesia, Cincinnati Children Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Ana Franco-Villanueva
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Christian Romancheck
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Rachel L. Morano
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Brittany L. Smith
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Benjamin A. Packard
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
| | - Steve C. Danzer
- Department of Anesthesia, Cincinnati Children Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - James P. Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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20
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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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21
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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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Brain Injury-Induced Synaptic Reorganization in Hilar Inhibitory Neurons Is Differentially Suppressed by Rapamycin. eNeuro 2017; 4:eN-NWR-0134-17. [PMID: 29085896 PMCID: PMC5659239 DOI: 10.1523/eneuro.0134-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 09/07/2017] [Accepted: 09/20/2017] [Indexed: 12/18/2022] Open
Abstract
Following traumatic brain injury (TBI), treatment with rapamycin suppresses mammalian (mechanistic) target of rapamycin (mTOR) activity and specific components of hippocampal synaptic reorganization associated with altered cortical excitability and seizure susceptibility. Reemergence of seizures after cessation of rapamycin treatment suggests, however, an incomplete suppression of epileptogenesis. Hilar inhibitory interneurons regulate dentate granule cell (DGC) activity, and de novo synaptic input from both DGCs and CA3 pyramidal cells after TBI increases their excitability but effects of rapamycin treatment on the injury-induced plasticity of interneurons is only partially described. Using transgenic mice in which enhanced green fluorescent protein (eGFP) is expressed in the somatostatinergic subset of hilar inhibitory interneurons, we tested the effect of daily systemic rapamycin treatment (3 mg/kg) on the excitability of hilar inhibitory interneurons after controlled cortical impact (CCI)-induced focal brain injury. Rapamycin treatment reduced, but did not normalize, the injury-induced increase in excitability of surviving eGFP+ hilar interneurons. The injury-induced increase in response to selective glutamate photostimulation of DGCs was reduced to normal levels after mTOR inhibition, but the postinjury increase in synaptic excitation arising from CA3 pyramidal cell activity was unaffected by rapamycin treatment. The incomplete suppression of synaptic reorganization in inhibitory circuits after brain injury could contribute to hippocampal hyperexcitability and the eventual reemergence of the epileptogenic process upon cessation of mTOR inhibition. Further, the cell-selective effect of mTOR inhibition on synaptic reorganization after CCI suggests possible mechanisms by which rapamycin treatment modifies epileptogenesis in some models but not others.
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Iffland PH, Crino PB. Focal Cortical Dysplasia: Gene Mutations, Cell Signaling, and Therapeutic Implications. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2017; 12:547-571. [PMID: 28135561 DOI: 10.1146/annurev-pathol-052016-100138] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Focal cortical dysplasias (FCDs) are malformations of cortical development (MCDs) that are highly associated with medication-resistant epilepsy and are the most common cause of neocortical epilepsy in children. FCDs are a heterogeneous group of developmental disorders caused by germline or somatic mutations that occur in genes regulating the PI3K/Akt/mTOR pathway-a key pathway in neuronal growth and migration. Accordingly, FCDs are characterized by abnormal cortical lamination, cell morphology (e.g., cytomegaly), and cellular polarity. In some FCD subtypes, balloon cells express proteins typically seen in neuroglial progenitor cells. Because recurrent intractable seizures are a common feature of FCDs, epileptogenic electrophysiological properties are also observed in addition to local inflammation. Here, we will summarize the current literature regarding FCDs, addressing the current classification system, histopathology, molecular genetics, electrophysiology, and transcriptome and cell signaling changes.
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Affiliation(s)
- Philip H Iffland
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania 19140;
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland 21201;
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Akt Inhibitor Perifosine Prevents Epileptogenesis in a Rat Model of Temporal Lobe Epilepsy. Neurosci Bull 2017; 34:283-290. [PMID: 28786074 DOI: 10.1007/s12264-017-0165-7] [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: 03/30/2017] [Accepted: 05/16/2017] [Indexed: 12/19/2022] Open
Abstract
Accumulating data have revealed that abnormal activity of the mTOR (mammalian target of rapamycin) pathway plays an important role in epileptogenesis triggered by various factors. We previously reported that pretreatment with perifosine, an inhibitor of Akt (also called protein kinase B), abolishes the rapamycin-induced paradoxical increase of S6 phosphorylation in a rat model induced by kainic acid (KA). Since Akt is an upstream target in the mTOR signaling pathway, we set out to determine whether perifosine has a preventive effect on epileptogenesis. Here, we explored the effect of perifosine on the model of temporal epilepsy induced by KA in rats and found that pretreatment with perifosine had no effect on the severity or duration of the KA-induced status epilepticus. However, perifosine almost completely inhibited the activation of p-Akt and p-S6 both acutely and chronically following the KA-induced status epilepticus. Perifosine pretreatment suppressed the KA-induced neuronal death and mossy fiber sprouting. The frequency of spontaneous seizures was markedly decreased in rats pretreated with perifosine. Accordingly, rats pretreated with perifosine showed mild impairment in cognitive functions. Collectively, this study provides novel evidence in a KA seizure model that perifosine may be a potential drug for use in anti-epileptogenic therapy.
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Ablation of Newly Generated Hippocampal Granule Cells Has Disease-Modifying Effects in Epilepsy. J Neurosci 2017; 36:11013-11023. [PMID: 27798182 DOI: 10.1523/jneurosci.1371-16.2016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/21/2016] [Indexed: 12/30/2022] Open
Abstract
Hippocampal granule cells generated in the weeks before and after an epileptogenic brain injury can integrate abnormally into the dentate gyrus, potentially mediating temporal lobe epileptogenesis. Previous studies have demonstrated that inhibiting granule cell production before an epileptogenic brain insult can mitigate epileptogenesis. Here, we extend upon these findings by ablating newly generated cells after the epileptogenic insult using a conditional, inducible diphtheria-toxin receptor expression strategy in mice. Diphtheria-toxin receptor expression was induced among granule cells born up to 5 weeks before pilocarpine-induced status epilepticus and these cells were then eliminated beginning 3 d after the epileptogenic injury. This treatment produced a 50% reduction in seizure frequency, but also a 20% increase in seizure duration, when the animals were examined 2 months later. These findings provide the first proof-of-concept data demonstrating that granule cell ablation therapy applied at a clinically relevant time point after injury can have disease-modifying effects in epilepsy. SIGNIFICANCE STATEMENT These findings support the long-standing hypothesis that newly generated dentate granule cells are pro-epileptogenic and contribute to the occurrence of seizures. This work also provides the first evidence that ablation of newly generated granule cells can be an effective therapy when begun at a clinically relevant time point after an epileptogenic insult. The present study also demonstrates that granule cell ablation, while reducing seizure frequency, paradoxically increases seizure duration. This paradoxical effect may reflect a disruption of homeostatic mechanisms that normally act to reduce seizure duration, but only when seizures occur frequently.
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Long-term Fate Mapping to Assess the Impact of Postnatal Isoflurane Exposure on Hippocampal Progenitor Cell Productivity. Anesthesiology 2017; 125:1159-1170. [PMID: 27655218 DOI: 10.1097/aln.0000000000001358] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Exposure to isoflurane increases apoptosis among postnatally generated hippocampal dentate granule cells. These neurons play important roles in cognition and behavior, so their permanent loss could explain deficits after surgical procedures. METHODS To determine whether developmental anesthesia exposure leads to persistent deficits in granule cell numbers, a genetic fate-mapping approach to label a cohort of postnatally generated granule cells in Gli1-CreER::GFP bitransgenic mice was utilized. Green fluorescent protein (GFP) expression was induced on postnatal day 7 (P7) to fate map progenitor cells, and mice were exposed to 6 h of 1.5% isoflurane or room air 2 weeks later (P21). Brain structure was assessed immediately after anesthesia exposure (n = 7 controls and 8 anesthesia-treated mice) or after a 60-day recovery (n = 8 controls and 8 anesthesia-treated mice). A final group of C57BL/6 mice was exposed to isoflurane at P21 and examined using neurogenesis and cell death markers after a 14-day recovery (n = 10 controls and 16 anesthesia-treated mice). RESULTS Isoflurane significantly increased apoptosis immediately after exposure, leading to cell death among 11% of GFP-labeled cells. Sixty days after isoflurane exposure, the number of GFP-expressing granule cells in treated animals was indistinguishable from control animals. Rates of neurogenesis were equivalent among groups at both 2 weeks and 2 months after treatment. CONCLUSIONS These findings suggest that the dentate gyrus can restore normal neuron numbers after a single, developmental exposure to isoflurane. The authors' results do not preclude the possibility that the affected population may exhibit more subtle structural or functional deficits. Nonetheless, the dentate appears to exhibit greater resiliency relative to nonneurogenic brain regions, which exhibit permanent neuron loss after isoflurane exposure.
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Garcia-Cairasco N, Umeoka EHL, Cortes de Oliveira JA. The Wistar Audiogenic Rat (WAR) strain and its contributions to epileptology and related comorbidities: History and perspectives. Epilepsy Behav 2017; 71:250-273. [PMID: 28506440 DOI: 10.1016/j.yebeh.2017.04.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the context of modeling epilepsy and neuropsychiatric comorbidities, we review the Wistar Audiogenic Rat (WAR), first introduced to the neuroscience international community more than 25years ago. The WAR strain is a genetically selected reflex model susceptible to audiogenic seizures (AS), acutely mimicking brainstem-dependent tonic-clonic seizures and chronically (by audiogenic kindling), temporal lobe epilepsy (TLE). Seminal neuroethological, electrophysiological, cellular, and molecular protocols support the WAR strain as a suitable and reliable animal model to study the complexity and emergent functions typical of epileptogenic networks. Furthermore, since epilepsy comorbidities have emerged as a hot topic in epilepsy research, we discuss the use of WARs in fields such as neuropsychiatry, memory and learning, neuroplasticity, neuroendocrinology, and cardio-respiratory autonomic regulation. Last, but not least, we propose that this strain be used in "omics" studies, as well as with the most advanced molecular and computational modeling techniques. Collectively, pioneering and recent findings reinforce the complexity associated with WAR alterations, consequent to the combination of their genetically-dependent background and seizure profile. To add to previous studies, we are currently developing more powerful behavioral, EEG, and molecular methods, combined with computational neuroscience/network modeling tools, to further increase the WAR strain's contributions to contemporary neuroscience in addition to increasing knowledge in a wide array of neuropsychiatric and other comorbidities, given shared neural networks. During the many years that the WAR strain has been studied, a constantly expanding network of multidisciplinary collaborators has generated a growing research and knowledge network. Our current and major wish is to make the WARs available internationally to share our knowledge and to facilitate the planning and execution of multi-institutional projects, eagerly needed to contribute to paradigm shifts in epileptology. 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)
- Norberto Garcia-Cairasco
- Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil; Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil.
| | - Eduardo H L Umeoka
- Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil; Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil
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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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Li J, Kim JS, Abejuela VA, Lamano JB, Klein NJ, Christian CA. Disrupted female estrous cyclicity in the intrahippocampal kainic acid mouse model of temporal lobe epilepsy. Epilepsia Open 2016; 2:39-47. [PMID: 29750212 PMCID: PMC5939433 DOI: 10.1002/epi4.12026] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 11/08/2022] Open
Abstract
Objective Reproductive dysfunction is a comorbidity that commonly occurs with temporal lobe epilepsy (TLE). Characterization of this comorbidity in various models of TLE in mice will greatly facilitate mechanistic investigations of the relationship between reproductive disorders and seizures initiated in the hippocampus. Here we investigate the impact on female reproductive estrous cyclicity in the intrahippocampal kainic acid mouse model of TLE and demonstrate the utility of using this model for future mechanistic studies. Methods Kainic acid (KA) or saline vehicle was stereotaxically injected in the right dorsal hippocampus of adult female C57BL/6J mice. Development of epilepsy was assessed by video monitoring for behavioral seizures. Reproductive function was assessed by daily estrous cycle monitoring and ovarian morphology. Estrous cycles were monitored for up to 2 months after injection. Ovarian morphology was examined by histological staining and assessment of follicular and luteal development. Results We observed spontaneous behavioral seizures in 82% of kainic-acid-treated mice. Irregular estrous cycles developed within 2 months after kainic acid injection. Sixty-seven percent of KA-treated mice showed disrupted estrous cycles, typically characterized by increased estrous cycle length, increased time spent in diestrus (nonfertile stage), and decreased time spent in estrus by 42 days post-KA injection. The estrous cycle disruption, however, was not accompanied by major changes in ovarian morphology or follicular development. KA-treated mice also displayed increased weight gain compared to control mice. Significance These data indicate that comorbid female irregular estrous cyclicity arises in the intrahippocampal kainic acid mouse model of TLE. This is the first demonstration of disrupted reproductive endocrine function in a mouse model of TLE initially produced by an insult specifically targeted to the hippocampus. This model should thus be useful for basic studies investigating the neural mechanisms driving comorbid reproductive dysfunction in epilepsy in women.
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Affiliation(s)
- Jiang Li
- Neuroscience Program University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
| | - Jae Seong Kim
- Department of Molecular and Integrative Physiology University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
| | - Vincent A Abejuela
- Department of Molecular and Integrative Physiology University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
| | - Jason B Lamano
- Department of Molecular and Integrative Physiology University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
| | - Natalie J Klein
- Department of Molecular and Integrative Physiology University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
| | - Catherine A Christian
- Neuroscience Program University of Illinois at Urbana-Champaign Urbana Illinois U.S.A.,Department of Molecular and Integrative Physiology University of Illinois at Urbana-Champaign Urbana Illinois U.S.A
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Disrupted hippocampal network physiology following PTEN deletion from newborn dentate granule cells. Neurobiol Dis 2016; 96:105-114. [PMID: 27597527 DOI: 10.1016/j.nbd.2016.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/04/2016] [Accepted: 09/01/2016] [Indexed: 01/28/2023] Open
Abstract
Abnormal hippocampal granule cells are present in patients with temporal lobe epilepsy, and are a prominent feature of most animal models of the disease. These abnormal cells are hypothesized to contribute to epileptogenesis. Isolating the specific effects of abnormal granule cells on hippocampal physiology, however, has been difficult in traditional temporal lobe epilepsy models. While epilepsy induction in these models consistently produces abnormal granule cells, the causative insults also induce widespread cell death among hippocampal, cortical and subcortical structures. Recently, we demonstrated that introducing morphologically abnormal granule cells into an otherwise normal mouse brain - by selectively deleting the mTOR pathway inhibitor PTEN from postnatally-generated granule cells - produced hippocampal and cortical seizures. Here, we conducted acute slice field potential recordings to assess the impact of these cells on hippocampal function. PTEN deletion from a subset of granule cells reproduced aberrant responses present in traditional epilepsy models, including enhanced excitatory post-synaptic potentials (fEPSPs) and multiple, rather than single, population spikes in response to perforant path stimulation. These findings provide new evidence that abnormal granule cells initiate a process of epileptogenesis - in the absence of widespread cell death - which culminates in an abnormal dentate network similar to other models of temporal lobe epilepsy. Findings are consistent with the hypothesis that accumulation of abnormal granule cells is a common mechanism of temporal lobe epileptogenesis.
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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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