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Fine AL, Liebo G, Gavrilova RH, Britton JW. Seizure Semiology, EEG, and Imaging Findings in Epilepsy Secondary to Mitochondrial Disease. Front Neurol 2021; 12:779052. [PMID: 34912288 PMCID: PMC8666417 DOI: 10.3389/fneur.2021.779052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/28/2021] [Indexed: 11/27/2022] Open
Abstract
Background: Identification of an underlying mitochondrial disorder can be challenging due to the significant phenotypic variability between and within specific disorders. Epilepsy can be a presenting symptom with several mitochondrial disorders. In this study, we evaluated clinical, electrophysiologic, and imaging features in patients with epilepsy and mitochondrial disorders to identify common features, which could aid in earlier identification of a mitochondrial etiology. Methods: This is a retrospective case series from January 2011 to December 2019 at a tertiary referral center of patients with epilepsy and a genetically confirmed diagnosis of a mitochondrial disorder. A total of 164 patients were reviewed with 20 patients fulfilling inclusion criteria. Results: A total of 20 patients (14 females, 6 males) aged 0.5-61 years with epilepsy and genetically confirmed mitochondrial disorders were identified. Status epilepticus occurred in 15 patients, with focal status epilepticus in 13 patients, including 9 patients with visual features. Abnormalities over the posterior cerebral regions were seen in 66% of ictal recordings and 44% of imaging studies. All the patients were on nutraceutical supplementation with no significant change in disease progression seen. At last follow-up, eight patients were deceased and the remainder had moderate-to-severe disability. Discussion: In this series of patients with epilepsy and mitochondrial disorders, we found increased propensity for seizures arising from the posterior cerebral regions. Over time, electroencephalogram (EEG) and imaging abnormalities increasingly occurred over the posterior cerebral regions. Focal seizures and focal status epilepticus with visual symptoms were common. Additional study is needed on nutraceutical supplementation in mitochondrial disorders.
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Affiliation(s)
- Anthony L. Fine
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Greta Liebo
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Ralitza H. Gavrilova
- Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, United States
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2
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Singh S, Singh TG, Rehni AK, Sharma V, Singh M, Kaur R. Reviving mitochondrial bioenergetics: A relevant approach in epilepsy. Mitochondrion 2021; 58:213-226. [PMID: 33775871 DOI: 10.1016/j.mito.2021.03.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/03/2021] [Accepted: 03/22/2021] [Indexed: 02/06/2023]
Abstract
Epileptogenesis is most commonly associated with neurodegeneration and a bioenergetic defect attributing to the fact that mitochondrial dysfunction plays a key precursor for neuronal death. Mitochondria are the essential organelle of neuronal cells necessary for certain neurophysiological processes like neuronal action potential activity and synaptic transmission. The mitochondrial dysfunction disrupts calcium homeostasis leading to inhibitory interneuron dysfunction and increasing the excitatory postsynaptic potential. In epilepsy, the prolonged repetitive neuronal activity increases the excessive demand for energy and acidosis in the brain further increasing the intracellular calcium causing neuronal death. Similarly, the mitochondrial damage also leads to the decline of energy by dysfunction of the electron transport chain and abnormal production of the ROS triggering the apoptotic neuronal death. Thus, the elevated level of cytosolic calcium causes the mitochondria DNA damage coinciding with mtROS and releasing the cytochrome c binding to Apaf protein further initiating the apoptosis resulting in epileptic encephalopathies. The various genetic and mRNA studies of epilepsy have explored the various pathogenic mutations of genes affecting the mitochondria functioning further initiating the neuronal excitotoxicity. Based on the results of previous studies, the recent therapeutic approaches are targeting basic mitochondrial processes, such as energy metabolism or free-radical generation, or specific interactions of disease-related proteins with mitochondria and hold great promise to attenuate epileptogenesis. Therefore, the current review emphasizes the emerging insights to uncover the relation between mitochondrial dysfunction and ROS generation contributing to mechanisms underlying epileptic seizures.
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Affiliation(s)
- Shareen Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | | | - Ashish Kumar Rehni
- Cerebral Vascular Disease Research Laboratories, Department of Neurology and Neuroscience Program, University of Miami School of Medicine, Miami, FL 33101, USA
| | - Vivek Sharma
- Chitkara College of Pharmacy, Chitkara University, Punjab, India; Govt. College of Pharmacy, Rohru, District Shimla, Himachal Pradesh, 171207, India
| | - Manjinder Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Rupinder Kaur
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
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3
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Abstract
Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.
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Affiliation(s)
- Frank M C Besag
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK; University College London, London, UK; King's College London, London, UK.
| | - Michael J Vasey
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK
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4
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Abstract
Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.
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Affiliation(s)
- Frank M C Besag
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK; University College London, London, UK; King's College London, London, UK.
| | - Michael J Vasey
- East London NHS Foundation Trust, 5-7 Rush Court, Bedford MK40 3JT, UK
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5
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Kobylarek D, Iwanowski P, Lewandowska Z, Limphaibool N, Szafranek S, Labrzycka A, Kozubski W. Advances in the Potential Biomarkers of Epilepsy. Front Neurol 2019; 10:685. [PMID: 31312171 PMCID: PMC6614180 DOI: 10.3389/fneur.2019.00685] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is a group of chronic neurological disorders characterized by recurrent, spontaneous, and unpredictable seizures. It is one of the most common neurological disorders, affecting tens of millions of people worldwide. Comprehensive studies on epilepsy in recent decades have revealed the complexity of epileptogenesis, in which immunological processes, epigenetic modifications, and structural changes in neuronal tissues have been identified as playing a crucial role. This review discusses the recent advances in the biomarkers of epilepsy. We evaluate the possible molecular background underlying the clinical changes observed in recent studies, focusing on therapeutic investigations, and the evidence of their safety and efficacy in the human population. This article reviews the pathophysiology of epilepsy, including recent reports on the effects of oxidative stress and hypoxia, and focuses on specific biomarkers and their clinical implications, along with further perspectives in epilepsy research.
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Affiliation(s)
- Dominik Kobylarek
- Department of Neurology, Poznan University of Medical Sciences, Poznan, Poland
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6
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Lee S, Na JH, Lee YM. Epilepsy in Leigh Syndrome With Mitochondrial DNA Mutations. Front Neurol 2019; 10:496. [PMID: 31139141 PMCID: PMC6518976 DOI: 10.3389/fneur.2019.00496] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 04/24/2019] [Indexed: 12/19/2022] Open
Abstract
Background: Leigh syndrome is a mitochondrial cytopathy that presents as a neurodegenerative disease with apparent manifestation in the central nervous system. The aim of the present study was to describe its dominant neurological clinical features and analyze data related to epilepsy in Leigh syndrome accompanied by a mitochondrial DNA mutation. Methods: Whole mitochondrial sequencing was performed on 125 patients clinically suspected of Leigh syndrome. Among them, 25 patients were identified to have mitochondrial DNA associated Leigh syndrome. Electroencephalography (EEG) findings, semiology, brain imaging findings, and biochemical results, were evaluated. We also compared brain magnetic resonance imaging findings and biochemical features in patients with Leigh syndrome based on the presence of epilepsy. Results: Clinical seizures were observed in 14 out of 25 enrolled patients (56%), with focal seizures being the most common type (6/14, 42.8%). All patients were found to have slow and disorganized background neural activity while eight exhibited epileptic discharges on EEG. Mutations at base pairs 10,191 and 8,993 were revealed in a relatively larger number of patients of Leigh syndrome with epilepsy. The presence of gastrointestinal symptoms was significantly more frequent in the epilepsy group (P = 0.042). Diffuse cerebral atrophy was significantly increased (P = 0.042) and cortex signal abnormalities were also increased (P = 0.033) in the epilepsy group. Conclusions: Patients with Leigh syndrome and mitochondrial DNA mutations had a high proportion of central nervous system comorbidities, though the prevalence of epilepsy in this population was not particularly high. Various types of seizure and EEG findings are common in those with Leigh syndrome. Future imaging studies involving more patients and proper mitochondrial DNA mutation analyses are needed to further evaluate the natural course of Leigh syndrome with epilepsy.
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Affiliation(s)
- Sunho Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Ji-Hoon Na
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Young-Mock Lee
- Departments of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea.,Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
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7
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Mai HN, Sharma N, Jeong JH, Shin EJ, Pham DT, Trinh QD, Lee YJ, Jang CG, Nah SY, Bing G, Kim HC. P53 knockout mice are protected from cocaine-induced kindling behaviors via inhibiting mitochondrial oxidative burdens, mitochondrial dysfunction, and proapoptotic changes. Neurochem Int 2019; 124:68-81. [DOI: 10.1016/j.neuint.2018.12.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/21/2018] [Accepted: 12/28/2018] [Indexed: 11/30/2022]
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8
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Dechandt CRP, Vicentini TM, Lanfredi GP, Silva-Jr RMP, Espreafico EM, de Oliveira JAC, Faça VM, Garcia-Cairasco N, Alberici LC. The highly efficient powerhouse in the Wistar audiogenic rat, an epileptic rat strain. Am J Physiol Regul Integr Comp Physiol 2018; 316:R243-R254. [PMID: 30517024 DOI: 10.1152/ajpregu.00254.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Wistar audiogenic rat (WAR) is an animal model of tonic-clonic epileptic seizures, developed after genetic selection by sister × brother inbreeding of Wistar rats susceptible to sound stimuli. Although metabolic changes have been described in this strain, nothing is known about its mitochondrial metabolism. Here, we addressed mitochondrial aspects of oxidative phosphorylation, oxidative stress, biogenesis, and dynamics in liver, skeletal muscle, and heart of male WARs and correlating them with physiological aspects of body metabolism. The results showed higher mitochondrial content, respiration rates in phosphorylation and noncoupled states, and H2O2 production in WARs. Liver presented higher content of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) and mammalian target of rapamycin, proteins related to mitochondrial biogenesis. In agreement, isolated liver mitochondria from WARs showed higher respiration rates in phosphorylation state and ADP-to-O ratio, as well as higher content of proteins related to electron transport chain ATP synthase, TCA cycle, and mitochondrial fusion and fission compared with their Wistar counterparts. Mitochondria with higher area and perimeter and more variable shapes were found in liver and soleus from WARs in addition to lower reduced-to-oxidized glutathione ratio. In vivo, WARs demonstrated lower body mass and energy expenditure but higher food and water intake and amino acid oxidation. When exposed to a running test, WARs reached higher speed and resisted for a longer time and distance than their Wistar controls. In conclusion, the WAR strain has mitochondrial changes in liver, skeletal muscle, and heart that improve its mitochondrial capacity of ATP production, making it an excellent rat model to study PGC1α overexpression and mitochondrial function in different physiological conditions or facing pathological challenges.
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Affiliation(s)
- Carlos Roberto Porto Dechandt
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Tatiane M Vicentini
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Guilherme Pauperio Lanfredi
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Rui M P Silva-Jr
- Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Enilza Maria Espreafico
- Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - José A Cortes de Oliveira
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Vitor Marcel Faça
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Norberto Garcia-Cairasco
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luciane Carla Alberici
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Ribeirão Preto, São Paulo , Brazil
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9
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Hikmat O, Eichele T, Tzoulis C, Bindoff LA. Understanding the Epilepsy in POLG Related Disease. Int J Mol Sci 2017; 18:ijms18091845. [PMID: 28837072 PMCID: PMC5618494 DOI: 10.3390/ijms18091845] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 12/31/2022] Open
Abstract
Epilepsy is common in polymerase gamma (POLG) related disease and is associated with high morbidity and mortality. Epileptiform discharges typically affect the occipital regions initially and focal seizures, commonly evolving to bilateral convulsive seizures which are the most common seizure types in both adults and children. Our work has shown that mtDNA depletion—i.e., the quantitative loss of mtDNA—in neurones is the earliest and most important factor of the subsequent development of cellular dysfunction. Loss of mtDNA leads to loss of mitochondrial respiratory chain (MRC) components that, in turn, progressively disables energy metabolism. This critically balanced neuronal energy metabolism leads to both a chronic and continuous attrition (i.e., neurodegeneration) and it leaves the neurone unable to cope with increased demand that can trigger a potentially catastrophic cycle that results in acute focal necrosis. We believe that it is the onset of epilepsy that triggers the cascade of damage. These events can be identified in the stepwise evolution that characterizes the clinical, Electroencephalography (EEG), neuro-imaging, and neuropathology findings. Early recognition with prompt and aggressive seizure management is vital and may play a role in modifying the epileptogenic process and improving survival.
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Affiliation(s)
- Omar Hikmat
- Department of Pediatrics, Haukeland University Hospital, 5021 Bergen, Norway.
- Department of Clinical Medicine (K1), University of Bergen, 5020 Bergen, Norway.
| | - Tom Eichele
- K.G. Jebsen Center for Research on Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway.
- Department of Biological and Medical Psychology, University of Bergen, 5009 Bergen, Norway.
- Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway.
| | - Charalampos Tzoulis
- Department of Clinical Medicine (K1), University of Bergen, 5020 Bergen, Norway.
- Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway.
| | - Laurence A Bindoff
- Department of Clinical Medicine (K1), University of Bergen, 5020 Bergen, Norway.
- Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway.
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10
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Cao DZ. [Mitochondrial diseases and epilepsy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:502-504. [PMID: 28506337 PMCID: PMC7389136 DOI: 10.7499/j.issn.1008-8830.2017.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/25/2017] [Indexed: 06/07/2023]
Affiliation(s)
- De-Zhi Cao
- Department of Neurology, Shenzhen Children's Hospital, Shenzhen, Guangdong 518038, China
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11
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Mitophagy in Refractory Temporal Lobe Epilepsy Patients with Hippocampal Sclerosis. Cell Mol Neurobiol 2017; 38:479-486. [PMID: 28405902 DOI: 10.1007/s10571-017-0492-2] [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: 12/26/2016] [Accepted: 04/07/2017] [Indexed: 02/05/2023]
Abstract
This study aimed to determine if there is an association between mitophagy and refractory temporal lobe epilepsy (rTLE) with hippocampal sclerosis. During epilepsy surgery, we collected tissue samples from the hippocampi and temporal lobe cortexes of rTLE patients with hippocampal sclerosis (as diagnosed by a pathologist). Transmission electron microscopy (TEM) was used to study the ultrastructural features of the tissue. To probe for mitophagy, we used fluorescent immunolabeling to determine if mitochondrial and autophagosomal markers colocalized. Fourteen samples were examined. TEM results showed that early autophagosomes were present and mitochondria were impaired to different degrees in hippocampi. Immunofluorescent labeling showed colocalization of the autophagosome marker LC3B with the mitochondrial marker TOMM20 in hippocampi and temporal lobe cortexes, indicating the presence of mitophagy. Mitochondrial and autophagosomal marker colocalization was lower in hippocampus than in temporal lobe cortex (P < 0.001). Accumulation of autophagosomes and mitophagy activation are implicated in rTLE with hippocampal sclerosis. Aberrant accumulation of damaged mitochondria, especially in the hippocampus, can be attributed to defects in mitophagy, which may participate in epileptogenesis.
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12
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Evaluation of the Effect of Naringenin on Pentylenetetrazole and Maximal Electroshock-Induced Convulsions in Mice. Jundishapur J Nat Pharm Prod 2016. [DOI: 10.5812/jjnpp.31384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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13
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Khodayar MJ, Salehi S, Rezaei M, Siahpoosh A, Khazaei A, Houshmand G. Evaluation of the Effect of Naringenin on Pentylenetetrazole and Maximal Electroshock-Induced Convulsions in Mice. Jundishapur J Nat Pharm Prod 2016. [DOI: 10.17795/jjnpp-31384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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14
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Volmering E, Niehusmann P, Peeva V, Grote A, Zsurka G, Altmüller J, Nürnberg P, Becker AJ, Schoch S, Elger CE, Kunz WS. Neuropathological signs of inflammation correlate with mitochondrial DNA deletions in mesial temporal lobe epilepsy. Acta Neuropathol 2016; 132:277-288. [PMID: 26993140 DOI: 10.1007/s00401-016-1561-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/26/2016] [Accepted: 03/11/2016] [Indexed: 11/27/2022]
Abstract
Accumulation of mitochondrial DNA (mtDNA) deletions has been proposed to be responsible for the presence of respiratory-deficient neurons in several CNS diseases. Deletions are thought to originate from double-strand breaks due to attack of reactive oxygen species (ROS) of putative inflammatory origin. In epileptogenesis, emerging evidence points to chronic inflammation as an important feature. Here we aimed to analyze the potential association of inflammation and mtDNA deletions in the hippocampal tissue of patients with mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS). Hippocampal and parahippocampal tissue samples from 74 patients with drug-refractory mTLE served for mtDNA analysis by multiplex PCR as well as long-range PCR, single-molecule PCR and ultra-deep sequencing of mtDNA in selected samples. Patients were sub-classified according to neuropathological findings. Semi-quantitative assessment of neuronal cell loss was performed in the hippocampal regions CA1-CA4. Inflammatory infiltrates were quantified by cell counts in the CA1, CA3 and CA4 regions from well preserved hippocampal samples (n = 33). Samples with HS showed a significantly increased frequency of a 7436-bp mtDNA deletion (p < 0.0001) and a higher proportion of somatic G>T transversions compared to mTLE patients with different histopathology. Interestingly, the number of T-lymphocytes in the hippocampal CA1, CA3 and CA4 regions was, similar to the 7436-bp mtDNA deletion, significantly increased in samples with HS compared to other subgroups. Our findings show a coincidence of HS, increased somatic G>T transversions, the presence of a specific mtDNA deletion, and increased inflammatory infiltrates. These results support the hypothesis that chronic inflammation leads to mitochondrial dysfunction by ROS-mediated mtDNA mutagenesis which promotes epileptogenesis and neuronal cell loss in patients with mTLE and HS.
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Affiliation(s)
- Elisa Volmering
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Pitt Niehusmann
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
- Department of Neuro-/Pathology, Oslo University Hospital, Oslo, Norway
| | - Viktoriya Peeva
- Division of Neurochemistry, Department of Epileptology, University Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany
| | - Alexander Grote
- Department of Neurosurgery, University of Bonn Medical Center, Bonn, Germany
| | - Gábor Zsurka
- Division of Neurochemistry, Department of Epileptology, University Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Institute of Human Genetics, University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Albert J Becker
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
- Translational Epilepsy Research Section, University of Bonn Medical Center, Bonn, Germany
| | - Susanne Schoch
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
- Translational Epilepsy Research Section, University of Bonn Medical Center, Bonn, Germany
| | - Christian E Elger
- Division of Neurochemistry, Department of Epileptology, University Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany
| | - Wolfram S Kunz
- Division of Neurochemistry, Department of Epileptology, University Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Li F, Liu L. SIRT5 Deficiency Enhances Susceptibility to Kainate-Induced Seizures and Exacerbates Hippocampal Neurodegeneration not through Mitochondrial Antioxidant Enzyme SOD2. Front Cell Neurosci 2016; 10:171. [PMID: 27445698 PMCID: PMC4922023 DOI: 10.3389/fncel.2016.00171] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022] Open
Abstract
Epilepsy is a common and serious neurological disorder characterized by occurrence of recurrent spontaneous seizures, and emerging evidences support the association of mitochondrial dysfunction with epilepsy. Sirtuin 5 (SIRT5), localized in mitochondrial matrix, has been considered as an important functional modulator of mitochondria that contributes to ageing and neurological diseases. Our data shows that SIRT5 deficiency strikingly increased mortality rate and severity of response to epileptic seizures, dramatically exacerbated hippocampal neuronal loss and degeneration in mice exposed to Kainate (KA), and triggered more severe reactive astrogliosis. We found that the expression of mitochondrial SIRT5 of injured hippocampus was relatively up-regulated, indicating its potential contribution to the comparably increased survival of these cells and its possible neuroprotective role. Unexpectedly, SIRT5 seems not to apparently alter the decline of antioxidant enzymes superoxide dismutase 2 (SOD2) and glutathione peroxidase (GPx) in hippocampus caused by KA exposure in our paradigm, which indicates the protective role of SIRT5 on seizures and cellular degeneration might through different regulatory mechanism that would be explored in the future. In the present study, we provided strong evidences for the first time to demonstrate the association between SIRT5 and epilepsy, which offers a new understanding of the roles of SIRT5 in mitochondrial functional regulation. The neuroprotection of SIRT5 in KA-induced epileptic seizure and neurodegeneration will improve our current knowledge of the nature of SIRT5 in central nervous system (CNS) and neurological diseases.
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Affiliation(s)
- Fengling Li
- Department of Pharmacy, Linyi Tumor Hospital Linyi, Shandong, China
| | - Lei Liu
- Department of Anesthesiology, University of FloridaGainesville, FL, USA; Center for Translational Research in Neurodegenerative Disease, University of FloridaGainesville, FL, USA
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16
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Travaglione S, Ballan G, Fortuna A, Ferri A, Guidotti M, Campana G, Fiorentini C, Loizzo S. CNF1 Enhances Brain Energy Content and Counteracts Spontaneous Epileptiform Phenomena in Aged DBA/2J Mice. PLoS One 2015; 10:e0140495. [PMID: 26457896 PMCID: PMC4601759 DOI: 10.1371/journal.pone.0140495] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/25/2015] [Indexed: 11/19/2022] Open
Abstract
Epilepsy, one of the most common conditions affecting the brain, is characterized by neuroplasticity and brain cell energy defects. In this work, we demonstrate the ability of the Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1) to counteract epileptiform phenomena in inbred DBA/2J mice, an animal model displaying genetic background with an high susceptibility to induced- and spontaneous seizures. Via modulation of the Rho GTPases, CNF1 regulates actin dynamics with a consequent increase in spine density and length in pyramidal neurons of rat visual cortex, and influences the mitochondrial homeostasis with remarkable changes in the mitochondrial network architecture. In addition, CNF1 improves cognitive performances and increases ATP brain content in mouse models of Rett syndrome and Alzheimer's disease. The results herein reported show that a single dose of CNF1 induces a remarkable amelioration of the seizure phenotype, with a significant augmentation in neuroplasticity markers and in cortex mitochondrial ATP content. This latter effect is accompanied by a decrease in the expression of mitochondrial fission proteins, suggesting a role of mitochondrial dynamics in the CNF1-induced beneficial effects on this epileptiform phenotype. Our results strongly support the crucial role of brain energy homeostasis in the pathogenesis of certain neurological diseases, and suggest that CNF1 could represent a putative new therapeutic tool for epilepsy.
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Affiliation(s)
- Sara Travaglione
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
| | - Giulia Ballan
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
| | - Andrea Fortuna
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
| | - Alberto Ferri
- Institute of Cellular Biology and Neurobiology, CNR, Via del Fosso di Fiorano 64/65, 00143, Roma, Italy
| | - Marco Guidotti
- Department of Veterinary Public Health and Food Safety, Viale Regina Elena 299, 00161, Roma, Italy
| | - Gabriele Campana
- Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 48, 40126, Bologna, Italy
| | - Carla Fiorentini
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
| | - Stefano Loizzo
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
- * E-mail:
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Rahman S. Pathophysiology of mitochondrial disease causing epilepsy and status epilepticus. Epilepsy Behav 2015; 49:71-5. [PMID: 26162691 DOI: 10.1016/j.yebeh.2015.05.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 05/01/2015] [Indexed: 01/08/2023]
Abstract
Epilepsy is part of the clinical phenotype in nearly 40% of children with mitochondrial disease, yet the underlying molecular mechanisms remain poorly understood. Energy depletion has been postulated as the cause of mitochondrial epilepsy, but if this were the case, then 100% of patients with mitochondrial disease would be expected to present with seizures. This review explores other potential disease mechanisms underlying mitochondrial epilepsy, including oxidative stress, impaired calcium homeostasis, immune dysfunction, and deficiency of vitamins, cofactors, reducing equivalents, and other metabolites. Different mechanisms are likely to predominate in different mitochondrial disorders, since mitochondrial function varies between neurons and astrocytes, between different types of neurons, and in different brain regions. Systematic studies in cell and animal models of mitochondrial disease are needed in order to develop effective therapies for mitochondrial epilepsy. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Shamima Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, London, UK; Metabolic Unit, Great Ormond Street Hospital, London, UK.
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18
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Bhandary S, Aguan K. Pyruvate dehydrogenase complex deficiency and its relationship with epilepsy frequency--An overview. Epilepsy Res 2015; 116:40-52. [PMID: 26354166 DOI: 10.1016/j.eplepsyres.2015.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/29/2015] [Accepted: 07/05/2015] [Indexed: 12/18/2022]
Abstract
The pyruvate dehydrogenase complex (PDHc) is a member of a family of multienzyme complexes that provides the link between glycolysis and the tricarboxylic acid (TCA) cycle by catalyzing the physiologically irreversible decarboxylation of various 2-oxoacid substrates to their corresponding acyl-CoA derivatives, NADH and CO2. PDHc deficiency is a metabolic disorder commonly associated with lactic acidosis, progressive neurological and neuromuscular degeneration that vary with age and gender. In this review, we aim to discuss the relationship between occurrence of epilepsy and PDHc deficiency associated with the pyruvate dehydrogenase complex (E1α subunit (PDHA1) and E1β subunit (PDHB)) and PDH phosphatase (PDP) deficiency. PDHc plays a crucial role in the aerobic carbohydrate metabolism and regulates the use of carbohydrate as the source of oxidative energy. In severe PDHc deficiency, the energy deficit impairs brain development in utero resulting in physiological and structural changes in the brain that contributes to the subsequent onset of epileptogenesis. Epileptogenesis in PDHc deficiency is linked to energy failure and abnormal neurotransmitter metabolism that progressively alters neuronal excitability. This metabolic blockage might be restricted via inclusion of ketogenic diet that is broken up by β-oxidation and directly converting it to acetyl-CoA, and thereby improving the patient's health condition. Genetic counseling is essential as PDHA1 deficiency is X-linked. The demonstration of the X-chromosome localization of PDHA1 resolved a number of questions concerning the variable phenotype displayed by patients with E1 deficiency. Most patients show a broad range of neurological abnormalities, with the severity showing some dependence on the nature of the mutation in the Elα gene, while PDHB and PDH phosphatase (PDP) deficiencies are of autosomal recessive inheritance. However, in females, the disorder is further complicated by the pattern of X-chromosome inactivation, i.e., unfavorable lyonization. Furthermore research should focus on epileptogenic animal models; this might pave a new way toward identification of the pathophysiology of this challenging disorder.
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Affiliation(s)
- Suman Bhandary
- Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong 793 022, India; Division of Molecular Medicine, Bose Institute, Kolkata 700 054, India
| | - Kripamoy Aguan
- Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong 793 022, India.
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19
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Frye RE. Metabolic and mitochondrial disorders associated with epilepsy in children with autism spectrum disorder. Epilepsy Behav 2015; 47:147-57. [PMID: 25440829 DOI: 10.1016/j.yebeh.2014.08.134] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 01/07/2023]
Abstract
Autism spectrum disorder (ASD) affects a significant number of individuals in the United States, with the prevalence continuing to grow. A significant proportion of individuals with ASD have comorbid medical conditions such as epilepsy. In fact, treatment-resistant epilepsy appears to have a higher prevalence in children with ASD than in children without ASD, suggesting that current antiepileptic treatments may be suboptimal in controlling seizures in many individuals with ASD. Many individuals with ASD also appear to have underlying metabolic conditions. Metabolic conditions such as mitochondrial disease and dysfunction and abnormalities in cerebral folate metabolism may affect a substantial number of children with ASD, while other metabolic conditions that have been associated with ASD such as disorders of creatine, cholesterol, pyridoxine, biotin, carnitine, γ-aminobutyric acid, purine, pyrimidine, and amino acid metabolism and urea cycle disorders have also been associated with ASD without the prevalence clearly known. Interestingly, all of these metabolic conditions have been associated with epilepsy in children with ASD. The identification and treatment of these disorders could improve the underlying metabolic derangements and potentially improve behavior and seizure frequency and/or severity in these individuals. This paper provides an overview of these metabolic disorders in the context of ASD and discusses their characteristics, diagnostic testing, and treatment with concentration on mitochondrial disorders. To this end, this paper aims to help optimize the diagnosis and treatment of children with ASD and epilepsy. This article is part of a Special Issue entitled "Autism and Epilepsy".
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Affiliation(s)
- Richard E Frye
- Autism Research Program, Arkansas Children's Hospital Research Institute, Little Rock, AR, USA; Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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20
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Mitochondrial disorders and epilepsy. Rev Neurol (Paris) 2014; 170:375-80. [DOI: 10.1016/j.neurol.2014.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 11/21/2022]
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Avula S, Parikh S, Demarest S, Kurz J, Gropman A. Treatment of mitochondrial disorders. Curr Treat Options Neurol 2014; 16:292. [PMID: 24700433 DOI: 10.1007/s11940-014-0292-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OPINION STATEMENT While numerous treatments for mitochondrial disorders have been suggested, relatively few have undergone controlled clinical trials. Treatment of these disorders is challenging, as only symptomatic therapy is available. In this review we will focus on newer drugs and treatment trials in mitochondrial diseases, with a special focus on medications to avoid in treating epilepsy and ICU patient with mitochondrial disease, which has not been included in such a review. Readers are also referred to the opinion statement in A Modern Approach to the Treatment of Mitochondrial Disease published in Current Treatment Options in Neurology 2009. Many of the supplements used for treatment were reviewed in the previous abstract, and dosing guidelines were provided. The focus of this review is on items not previously covered in depth, and our discussion includes more recently studied compounds as well as any relevant updates on older compounds . We review a variety of vitamins and xenobiotics, including dichloroacetate (DCA), arginine, coenzyme Q10, idebenone, EPI-743, and exercise training. Treatment of epilepsy, which is a common feature in many mitochondrial phenotypes, warrants special consideration due to the added toxicity of certain medications, and we provide a discussion of these unique treatment challenges. Interesting, however, with only a few exceptions, the treatment strategies for epilepsy in mitochondrial cytopathies are the same as for epilepsy without mitochondrial dysfunction. We also discuss intensive care management, building upon similar reviews, adding new dimensions, and demonstrating the complexity of overall care of these patients.
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Affiliation(s)
- Sreenivas Avula
- Department of Neurology, Cleveland Clinic, Cleveland, OH, USA,
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22
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Atanasova M, Petkova Z, Pechlivanova D, Dragomirova P, Blazhev A, Tchekalarova J. Strain-dependent effects of long-term treatment with melatonin on kainic acid-induced status epilepticus, oxidative stress and the expression of heat shock proteins. Pharmacol Biochem Behav 2013; 111:44-50. [DOI: 10.1016/j.pbb.2013.08.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/10/2013] [Accepted: 08/14/2013] [Indexed: 11/28/2022]
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Boison D, Sandau US, Ruskin DN, Kawamura M, Masino SA. Homeostatic control of brain function - new approaches to understand epileptogenesis. Front Cell Neurosci 2013; 7:109. [PMID: 23882181 PMCID: PMC3712329 DOI: 10.3389/fncel.2013.00109] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/22/2013] [Indexed: 12/31/2022] Open
Abstract
Neuronal excitability of the brain and ongoing homeostasis depend not only on intrinsic neuronal properties, but also on external environmental factors; together these determine the functionality of neuronal networks. Homeostatic factors become critically important during epileptogenesis, a process that involves complex disruption of self-regulatory mechanisms. Here we focus on the bioenergetic homeostatic network regulator adenosine, a purine nucleoside whose availability is largely regulated by astrocytes. Endogenous adenosine modulates complex network function through multiple mechanisms including adenosine receptor-mediated pathways, mitochondrial bioenergetics, and adenosine receptor-independent changes to the epigenome. Accumulating evidence from our laboratories shows that disruption of adenosine homeostasis plays a major role in epileptogenesis. Conversely, we have found that reconstruction of adenosine's homeostatic functions provides new hope for the prevention of epileptogenesis. We will discuss how adenosine-based therapeutic approaches may interfere with epileptogenesis on an epigenetic level, and how dietary interventions can be used to restore network homeostasis in the brain. We conclude that reconstruction of homeostatic functions in the brain offers a new conceptual advance for the treatment of neurological conditions which goes far beyond current target-centric treatment approaches.
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Affiliation(s)
- Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, OR, USA
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Mohamed TM, Ghaffar HMA, El Husseiny RMR. Effects of tramadol, clonazepam, and their combination on brain mitochondrial complexes. Toxicol Ind Health 2013; 31:1325-33. [DOI: 10.1177/0748233713491814] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study is an unsubstantiated qualitative assessment of the abused drugs—tramadol and clonazepam. The aim of this study is to evaluate whether the effects of tramadol, clonazepam, and their combination on mitochondrial electron transport chain (ETC) complexes were influential at therapeutic or at progressively increasing doses. The study comprised of a total of 70 healthy male rats, aged 3 months. According to the drug intake regimen, animals were divided into seven groups: control, tramadol therapeutic, clonazepam therapeutic, combination therapeutic, tramadol abuse, clonazepam abuse, and combination abuse group. At the end of the experiment, brain mitochondrial ETC complexes (I, II, III, and IV) were evaluated. Histopathological examinations were also performed on brain tissues. The results showed that groups that received tramadol (therapeutic and abuse) suffered from weight loss. Tramadol abuse group and combination abuse group showed significant decrease in the activities of I, III, and IV complexes but not in the activity of complex II. In conclusion, tramadol but not clonazepam has been found to partially inhibit the activities of respiratory chain complexes I, III, and IV but not the activity of complex II and such inhibition occurred only at doses that exceeded the maximum recommended adult human daily therapeutic doses. This result explains the clinical and histopathological effects of tramadol, such as seizures and red neurons (marker for apoptosis), respectively.
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Affiliation(s)
- Tarek Mostafa Mohamed
- Biochemistry Division, Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt
| | - Hamdy M Abdel Ghaffar
- Forensic Medicine and Clinical toxicology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Rabee MR El Husseiny
- Biochemistry Division, Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt
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25
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Zhang X, Chen G, Lu Y, Liu J, Fang M, Luo J, Cao Q, Wang X. Association of Mitochondrial Letm1 with Epileptic Seizures. Cereb Cortex 2013; 24:2533-40. [DOI: 10.1093/cercor/bht118] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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Martinc B, Grabnar I, Vovk T. The role of reactive species in epileptogenesis and influence of antiepileptic drug therapy on oxidative stress. Curr Neuropharmacol 2012; 10:328-43. [PMID: 23730257 PMCID: PMC3520043 DOI: 10.2174/157015912804143504] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/23/2012] [Accepted: 09/03/2012] [Indexed: 01/09/2023] Open
Abstract
Epilepsy is considered one of the most common neurological disorders. The focus of this review is the acquired form of epilepsy, with the development process consisting of three major phases, the acute injury phase, the latency epileptogenesis phase, and the phase of spontaneous recurrent seizures. Nowadays, an increasing attention is paid to the possible interrelationship between oxidative stress resulting in disturbance of physiological signalling roles of calcium and free radicals in neuronal cells and mitochondrial dysfunction, cell damage, and epilepsy. The positive stimulation of mitochondrial calcium signals by reactive oxygen species and increased reactive oxygen species generation resulting from increased mitochondrial calcium can lead to a positive feedback loop. We propose that calcium can pose both, physiological and pathological effects of mitochondrial function, which can lead in neuronal cell death and consequent epileptic seizures. Various antiepileptic drugs may impair the endogenous antioxidative ability to prevent oxidative stress. Therefore, some antiepileptic drugs, especially from the older generation, may trigger oxygen-dependent tissue injury. The prooxidative effects of these antiepileptic drugs might lead to enhancement of seizure activity, resulting in loss of their efficacy or apparent functional tolerance and undesired adverse effects. Additionally, various reactive metabolites of antiepileptic drugs are capable of covalent binding to macromolecules which may lead to deterioration of the epileptic seizures and systemic toxicity. Since neuronal loss seems to be one of the major neurobiological abnormalities in the epileptic brain, the ability of antioxidants to attenuate seizure generation and the accompanying changes in oxidative burden, further support an important role of antioxidants as having a putative antiepileptic potential.
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Affiliation(s)
| | | | - Tomaž Vovk
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
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27
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Abstract
The mitochondrial respiratory chain is the final common pathway for energy production. Defects affecting this pathway can give rise to disease that presents at any age and affects any tissue. However, irrespective of genetic defect, epilepsy is common and there is a significant risk of status epilepticus. This review summarizes our current understanding of the epilepsy that occurs in mitochondrial disease, focusing on three of the most common disorders: mitochondrial myopathy encephalopathy, lactic acidosis and stroke-like episodes (MELAS), myoclonus epilepsy and ragged-red fibers (MERRF), and polymerase gamma (POLG) related disease. In addition, we review the pathogenesis and possible treatment of these disorders.
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28
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Jung S, Yang H, Kim BS, Chu K, Lee SK, Jeon D. The immunosuppressant cyclosporin A inhibits recurrent seizures in an experimental model of temporal lobe epilepsy. Neurosci Lett 2012; 529:133-8. [DOI: 10.1016/j.neulet.2012.08.087] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/17/2012] [Accepted: 08/30/2012] [Indexed: 12/11/2022]
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29
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Hsu YC, Yang FC, Perng CL, Tso AC, Wong LJC, Hsu CH. Adult-onset of Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS) Syndrome Presenting as Acute Meningoencephalitis: A Case Report. J Emerg Med 2012; 43:e163-6. [DOI: 10.1016/j.jemermed.2009.10.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 10/03/2009] [Accepted: 10/27/2009] [Indexed: 11/17/2022]
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30
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Caietta E, Cano A, Halbert C, Hugonenq C, Mancini J, Milh M, Lépine A, Villeneuve N, Chaussenot A, Paquis-Flucklinger V, Chabrol B. [Epilepsy and mitochondrial diseases: retrospective study on 53 epileptic children]. Arch Pediatr 2012; 19:794-802. [PMID: 22789745 DOI: 10.1016/j.arcped.2012.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 04/06/2012] [Accepted: 05/22/2012] [Indexed: 11/28/2022]
Abstract
AIM Mitochondrial disease is a heterogeneous disorder entity induced by defects in the mitochondrial respiratory chain complex. Neurological symptoms, including epilepsy, are common in children. The aim of this study was to research the clinical signs indicating mitochondrial disease. METHODS We retrospectively studied epileptic children who underwent a muscle and/or hepatic biopsy between 1995 and 2010 searching for a mitochondrial disease. Patients were separated into 2 groups depending on the biopsy result: group 1 (presence of mitochondrial disease) and group 2 (absence of mitochondrial disease). Epileptic phenotypes were compared between these 2 groups. In group 1, we specified the clinical phenotype and characterized mitochondrial disease. RESULTS Fifty-three children were included: 29 in group 1 and 24 in group 2. The average age at onset of epilepsy was 39.6 months in group 1 versus 11.8 months in group 2. In the 1st group, epilepsy was less refractory and associated with other clinical symptoms. CONCLUSIONS In this study, epilepsy did not appear to be a unique sign of mitochondrial disease. It most often appeared during the 2nd year of life and is correlated with multiorgan involvement, notably ophthalmologic, such as oculomotor apraxia, optic atrophy, and retinitis pigmentosa, as well as auditory (deafness) and hepatic (hepatic failure, hepatomegaly). On the other hand, in children who did not have mitochondrial disease, epilepsy often began earlier (before 3 months of age), it was refractory, isolated without multiorgan involvement, and seems to be due to genetic anomalies in developmental genes, a finding that requires further research.
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Affiliation(s)
- E Caietta
- Service de neurologie pédiatrique et des maladies héréditaires du métabolisme, CHU La Timone, Assistance publique-Hôpitaux de Marseille, 264, rue Saint-Pierre, 13005 Marseille, France.
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31
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Piórkowska K, Ropka-Molik K, Eckert R, Tyra M, Żukowski K. Analysis of polymorphisms of cathepsin B and cystatin B impact on economically important traits in pigs raised in Poland. Livest Sci 2012. [DOI: 10.1016/j.livsci.2012.02.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Kovac S, Abramov AY, Walker MC. Energy depletion in seizures: anaplerosis as a strategy for future therapies. Neuropharmacology 2012; 69:96-104. [PMID: 22659085 DOI: 10.1016/j.neuropharm.2012.05.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/08/2012] [Accepted: 05/11/2012] [Indexed: 01/11/2023]
Abstract
Seizure activity can lead to energy failure and neuronal injury, resulting in neurological and cognitive sequelae. Moreover, mutations affecting genes encoding for proteins that maintain energy homeostasis within the cell often result in an epileptic phenotype, implying that energy failure can contribute to epileptogenesis. Indeed, there is evidence to indicate that the efficacy of the ketogenic diet, a treatment for refractory epilepsy, can be partly explained by its effect on increasing energetic substrates. The ATP level, reflecting the energy level of a cell, is maintained by the potential gradient across the mitochondrial membrane. This potential gradient is maintained by NADH/H(+) equivalents, produced by reactions within the tricarboxylic acid cycle (TCA-cycle). Anaplerosis, the replenishment of TCA-cycle substrates, therefore represents an appealing strategy to address energy failure such as occurs in seizures. There is accumulating evidence that pyruvate, a classical anaplerotic substrate, has seizure suppressive effects and protects against seizure induced cell death. This review summarizes the evidence for the contribution of TCA cycle deficits in generating seizures. We highlight the role for TCA substrate supplementation in protecting against seizures and seizure induced cell death, and propose that these are important targets for future translational research addressing energy depletion in seizures. This article is part of the Special Issue entitled 'New Targets and Approaches to the Treatment of Epilepsy'.
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Affiliation(s)
- Stjepana Kovac
- UCL Institute of Neurology, University College London, Queen Square, WC1N 3BG London, UK.
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Abstract
Mitochondrial respiratory chain disorders are relatively common inborn errors of energy metabolism, with a combined prevalence of one in 5000. These disorders typically affect tissues with high energy requirements, and cerebral involvement occurs frequently in childhood, often manifesting in seizures. Mitochondrial diseases are genetically heterogeneous; to date, mutations have been reported in all 37 mitochondrially encoded genes and more than 80 nuclear genes. The major genetic causes of mitochondrial epilepsy are mitochondrial DNA mutations (including those typically associated with the mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes [MELAS] and myoclonic epilepsy with ragged red fibres [MERRF] syndromes); mutations in POLG (classically associated with Alpers syndrome but also presenting as the mitochondrial recessive ataxia syndrome [MIRAS], spinocerebellar ataxia with epilepsy [SCAE], and myoclonus, epilepsy, myopathy, sensory ataxia [MEMSA] syndromes in older individuals) and other disorders of mitochondrial DNA maintenance; complex I deficiency; disorders of coenzyme Q(10) biosynthesis; and disorders of mitochondrial translation such as RARS2 mutations. It is not clear why some genetic defects, but not others, are particularly associated with seizures. Epilepsy may be the presenting feature of mitochondrial disease but is often part of a multisystem clinical presentation. Mitochondrial epilepsy may be very difficult to manage, and is often a poor prognostic feature. At present there are no curative treatments for mitochondrial disease. Individuals with mitochondrial epilepsy are frequently prescribed multiple anticonvulsants, and the role of vitamins and other nutritional supplements and the ketogenic diet remain unproven.
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Affiliation(s)
- Shamima Rahman
- Mitochondrial Research Group, Clinical and Molecular Genetics Unit, UCL Institute of Child Health, University College London, 30 Guilford Street, London, UK.
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34
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Nangia S, Caraballo RH, Kang HC, Nordli DR, Scheffer IE. Is the ketogenic diet effective in specific epilepsy syndromes? Epilepsy Res 2012; 100:252-7. [PMID: 22424762 DOI: 10.1016/j.eplepsyres.2012.01.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 01/27/2012] [Accepted: 01/28/2012] [Indexed: 10/28/2022]
Abstract
Is the ketogenic diet (KD) more effective in certain epilepsy syndromes? The KD has been shown to be effective in treating multiple seizure types and epilepsy syndromes. We review the effectiveness of the KD in Dravet syndrome, epilepsy with myoclonic-atonic seizures, mitochondrial disease, tuberous sclerosis, late infantile and juvenile neuronal ceroid lipofuscinosis, and febrile infection-related epilepsy syndrome. In certain epilepsy syndromes, like epilepsy with myoclonic-atonic seizures, the diet should be considered early in the course of treatment.
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Affiliation(s)
- Srishti Nangia
- Children's Memorial Hospital Epilepsy Center, 2300 Children's Plaza, Box 29, Chicago, IL 60614-3363, USA
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Abstract
BACKGROUND Repetitively discharging neurons in epileptic foci have a high energy requirement that might be demonstrated histochemically as increased mitochondrial enzymatic activity in brain resections for epilepsy in children. MATERIALS AND METHODS Frozen sections were studied histochemically of 10 brain resections from 7 epileptic children, 2 months to 17 years of age. None had mitochondrial disease. Three patients had tuberous sclerosis (TS) or hemimegalencephy (HME). Tissues included hippocampus and neocortex. Oxidative enzymes were studied for respiratory chain complexes I, II, IV, using the muscle biopsy protocol. In addition, immunoreactivities of α-B-crystallin and transmission electron microscopy (EM) were performed. RESULTS Oxidative activities were variable in adjacent neurons within a field: a minority were intense, adjacent to neurons with weaker mitochondrial activity exhibiting poor contrast of the soma because of similar oxidative activity in surrounding neuropil. Endothelium of vessels uniformly exhibits strong activity. Alpha-B-crystallin reactivity was strong at these foci. EM confirmed an abundance of neuronal mitochondria with normal cristae. In TS and HME, many dysplastic neurons showed intense activity; balloon cells had sparse activity. CONCLUSIONS Histochemistry of mitochondrial oxidative enzymes reveals scattered and clustered neurons with stronger activities than others at epileptic foci. Such intensely staining neurons may be functionally "hypermetabolic" but they do not signify mitochondrial disease. Individual intensely stained neurons might be epileptogenic, but do not denote an epileptogenic field in the same manner as α-B-crystallin, which also was strongly reactive in these foci.
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36
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Boison D. Adenosine dysfunction in epilepsy. Glia 2011; 60:1234-43. [PMID: 22700220 DOI: 10.1002/glia.22285] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 11/30/2011] [Indexed: 12/13/2022]
Abstract
Extracellular levels of the brain's endogenous anticonvulsant and neuroprotectant adenosine largely depend on an astrocyte-based adenosine cycle, comprised of ATP release, rapid degradation of ATP into adenosine, and metabolic reuptake of adenosine through equilibrative nucleoside transporters and phosphorylation by adenosine kinase (ADK). Changes in ADK expression and activity therefore rapidly translate into changes of extracellular adenosine, which exerts its potent anticonvulsive and neuroprotective effects by activation of pre- and postsynaptic adenosine A(1) receptors. Increases in ADK increase neuronal excitability, whereas decreases in ADK render the brain resistant to seizures and injury. Importantly, ADK was found to be overexpressed and associated with astrogliosis and spontaneous seizures in rodent models of epilepsy, as well as in human specimen resected from patients with hippocampal sclerosis and temporal lobe epilepsy. Several lines of evidence indicate that overexpression of astroglial ADK and adenosine deficiency are pathological hallmarks of the epileptic brain. Consequently, adenosine augmentation therapies constitute a powerful approach for seizure prevention, which is effective in models of epilepsy that are resistant to conventional antiepileptic drugs. The adenosine kinase hypothesis of epileptogenesis suggests that adenosine dysfunction in epilepsy undergoes a biphasic response: an acute surge of adenosine that can be triggered by any type of injury might contribute to the development of astrogliosis via adenosine receptor-dependent and -independent mechanisms. Astrogliosis in turn is associated with overexpression of ADK, which was shown to be sufficient to trigger spontaneous recurrent electrographic seizures. Thus, ADK emerges as a promising target for the prediction and prevention of epilepsy.
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Affiliation(s)
- Detlev Boison
- R.S. Dow Neurobiology Labs, Legacy Research Institute, Portland, Oregon 97232, USA.
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Liang LP, Waldbaum S, Rowley S, Huang TT, Day BJ, Patel M. Mitochondrial oxidative stress and epilepsy in SOD2 deficient mice: attenuation by a lipophilic metalloporphyrin. Neurobiol Dis 2011; 45:1068-76. [PMID: 22200564 DOI: 10.1016/j.nbd.2011.12.025] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 11/15/2011] [Accepted: 12/04/2011] [Indexed: 01/15/2023] Open
Abstract
Epileptic seizures are a common feature associated with inherited mitochondrial diseases. This study investigated the role of mitochondrial oxidative stress in epilepsy resulting from mitochondrial dysfunction using cross-bred mutant mice lacking mitochondrial manganese superoxide dismutase (MnSOD or SOD2) and a lipophilic metalloporphyrin catalytic antioxidant. Video-EEG monitoring revealed that in the second to third week of postnatal life (P14-P21) B6D2F2 Sod2(-/-) mice exhibited frequent spontaneous motor seizures providing evidence that oxidative stress-induced mitochondrial dysfunction may contribute to epileptic seizures. To confirm the role of mitochondrial oxidative stress in epilepsy a newly developed lipophilic metalloporphyrin, AEOL 11207, with high potency for catalytic removal of endogenously generated reactive oxygen species was utilized. AEOL 11207-treated Sod2(-/-) mice showed a significant decrease in both the frequency and duration of spontaneous seizures but no effect on seizure severity. A significant increase in the average lifespan of AEOL 11207-treated Sod2(-/-) mice compared to vehicle-treated Sod2(-/-) mice was also observed. Indices of mitochondrial oxidative stress and damage (aconitase inactivation, 3-nitrotyrosine formation, and depletion of reduced coenzyme A) and ATP levels affecting neuronal excitability were significantly attenuated in the brains of AEOL 11207-treated Sod2(-/-) mice compared to vehicle-treated Sod2(-/-) mice. The occurrence of epileptic seizures in Sod2(-/-) mice and the ability of catalytic antioxidant therapy to attenuate seizure activity, mitochondrial dysfunction, and ATP levels suggest that ongoing mitochondrial oxidative stress can contribute to epilepsy associated with mitochondrial dysfunction and disease.
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Affiliation(s)
- Li-Ping Liang
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO 80045, USA
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Prasad AN, Levin S, Rupar CA, Prasad C. Menkes disease and infantile epilepsy. Brain Dev 2011; 33:866-76. [PMID: 21924848 DOI: 10.1016/j.braindev.2011.08.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 07/26/2011] [Accepted: 08/03/2011] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Menkes disease, an X linked recessive neurodegenerative disorder, results from a mutation in the gene coding for the copper transporting ATPase (ATP7A). Epilepsy is a major clinical feature of this disorder. We describe the clinical presentation, evolution of epilepsy and explore the biological underpinnings of epileptogenesis in Menkes disease. METHODS Longitudinal case study illustrating the natural history of epilepsy and results of subcutaneous cupric chloride supplementation in a patient with Menkes disease and literature review. RESULTS The onset and evolution of epilepsy in Menkes disease is marked by different stages. Early presentations typically involve focal seizures, with progression to epileptic spasms and a chronic late stage of epilepsy characterized by tonic seizures, myoclonic jerks, and multifocal epileptiform activity on the EEG. Morphological correlates in the brain include evidence of atrophy of grey matter, ventriculomegaly, tortuous intracranial vasculature, and white matter signal changes consistent with loss of myelin and axons. The presence of significant lactic acidosis in brain and cerebrospinal fluid suggests widespread disturbance in oxidative metabolism. Molecular consequences of the pathogenic ATP7A gene mutation lead to impairment in copper transport, which in turn causes deficiencies of key copper containing enzymes (dopamine β hydroxylase and cytochrome c oxidase). Microarray studies suggest widespread effects in dysregulation of genes involved in cellular responses to oxidative stress, ribosomal translation, signal transduction, mitochondrial function, and immune responses. Impairment of copper mediated NMDA receptor function further enhances neuronal excitability, excitotoxic neuronal injury, setting up a cascade that creates conditions for epileptogenesis to follow. CONCLUSION Neurological manifestations are likely related to perturbations in copper dependent enzymatic pathways involved in neurotransmitter and energy metabolism. Early diagnosis and institution of copper supplementation has been shown to be beneficial particularly in patients with residual ATP7A activity.
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Affiliation(s)
- Asuri N Prasad
- Department of Pediatrics, University of Western Ontario, London, Ontario, Canada.
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Lee HF, Chi CS, Tsai CR, Chen CH. Epileptic seizures in infants and children with mitochondrial diseases. Pediatr Neurol 2011; 45:169-74. [PMID: 21824564 DOI: 10.1016/j.pediatrneurol.2011.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 04/19/2011] [Indexed: 10/17/2022]
Abstract
The purpose of this study is to describe the characteristics of epileptic seizures in infants and children with mitochondrial diseases. From 1984 to December 2010, data from 46 of 76 patients diagnosed as having mitochondrial diseases with epileptic seizures were reviewed. Age at seizure onset, epileptic phenotypes, electroencephalogram findings, magnetic resonance imaging features, and treatment outcome in patients with syndromic or nonsyndromic mitochondrial diseases were analyzed. Thirty (65%) of 46 patients manifested seizures before the age of 1 year; 43% had Leigh syndrome and 53% had nonsyndromic mitochondrial diseases. Twenty-eight (61%) of 46 patients exhibited seizures as the manifesting complaint. Nineteen (68%) of 28 patients had nonsyndromic mitochondrial diseases. The most frequently observed electroencephalogram finding was background slow activity (28/46; 61%) in both groups. The most common cortical abnormality relevant to clinical seizures was diffuse brain atrophy on the brain magnetic resonance imaging (26/45; 58%), which was commonly observed in patients with nonsyndromic mitochondrial diseases (16/26; 62%). Despite treatment, 49% of patients experienced less than 50% seizure reduction rate, 77% of whom had nonsyndromic mitochondrial diseases. Leigh syndrome and nonsyndromic mitochondrial diseases often manifest as infantile seizures. Epileptic seizure as the initial complaint, diffuse brain atrophy, and refractory epilepsy were more common in patients with nonsyndromic mitochondrial diseases.
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Affiliation(s)
- Hsiu-Fen Lee
- Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan
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Folbergrová J, Kunz WS. Mitochondrial dysfunction in epilepsy. Mitochondrion 2011; 12:35-40. [PMID: 21530687 DOI: 10.1016/j.mito.2011.04.004] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 02/16/2011] [Accepted: 04/14/2011] [Indexed: 11/29/2022]
Abstract
Mitochondrial dysfunction has been identified as one potential cause of epileptic seizures. Impaired mitochondrial function has been reported for the seizure focus of patients with temporal lobe epilepsy and Ammon's horn sclerosis and of adult and immature animal models of epilepsy. Since mitochondrial oxidative phosphorylation provides the major source of ATP in neurons and mitochondria participate in cellular Ca(2+) homeostasis and generation of reactive oxygen species, their dysfunction strongly affects neuronal excitability and synaptic transmission. Therefore, mitochondrial dysfunction is proposed to be highly relevant for seizure generation. Additionally, mitochondrial dysfunction is known to trigger neuronal cell death, which is a prominent feature of therapy-resistant epilepsy. For this reason mitochondria have to be considered as promising targets for neuroprotective strategies in epilepsy.
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Affiliation(s)
- Jaroslava Folbergrová
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Zsurka G, Kunz WS. Mitochondrial dysfunction in neurological disorders with epileptic phenotypes. J Bioenerg Biomembr 2010; 42:443-8. [DOI: 10.1007/s10863-010-9314-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wang L, Liu G, He M, Shen L, Shen D, Lu Y, Wang X. Increased insulin receptor expression in anterior temporal neocortex of patients with intractable epilepsy. J Neurol Sci 2010; 296:64-8. [PMID: 20624623 DOI: 10.1016/j.jns.2010.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 05/31/2010] [Accepted: 06/07/2010] [Indexed: 11/08/2022]
Abstract
The insulin receptor (IR) is a tyrosine kinase receptor that binds to insulin and plays pivotal roles in energy homeostasis, neuronal growth, neuronal survival, synaptic plasticity and cognitive function. The biological mechanisms of intractable epilepsy involve energy metabolism, neuron loss, neurogenesis and abnormal neural networks. Here, we evaluated the expression of the IR in the anterior temporal neocortex of patients with intractable epilepsy (IE) by immunohistochemistry, double-label immunofluorescence and immunoblotting. We compared these tissues against histologically normal anterior temporal lobes from individuals treated for post-trauma intracranial hypertension. We found that the IR was coexpressed with neuron-specific enolase (NSE) and that IR expression increased in the anterior temporal neocortex of epileptic patients. On the basis of the potential physiological effects of IR, our findings suggest that increased expression of the IR is a consequence of epileptic seizures and a cause of IE.
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Affiliation(s)
- Liang Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
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Abstract
Mitochondrial Biogenesis in the Anticonvulsant Mechanism of the Ketogenic Diet. Bough KJ, Wetherington J, Hassel B, Pare JF, Gawryluk JW, Greene JG, Shaw R, Smith Y, Geiger JD, Dingledine RJ. Ann Neurol 2006;60:223–235. Objective The full anticonvulsant effect of the ketogenic diet (KD) can require weeks to develop in rats, suggesting that altered gene expression is involved. The KD typically is used in pediatric epilepsies, but is effective also in adolescents and adults. Our goal was to use microarray and complementary technologies in adolescent rats to understand its anticonvulsant effect. Methods Microarrays were used to define patterns of gene expression in the hippocampus of rats fed a KD or control diet for 3 weeks. Hippocampi from control- and KD-fed rats were also compared for the number of mitochondrial profiles in electron micrographs, the levels of selected energy metabolites and enzyme activities, and the effect of low glucose on synaptic transmission. Results Most striking was a coordinated upregulation of all (n = 34) differentially regulated transcripts encoding energy metabolism enzymes and 39 of 42 transcripts encoding mitochondrial proteins, which was accompanied by an increased number of mitochondrial profiles, a higher phosphocreatine/creatine ratio, elevated glutamate levels, and decreased glycogen levels. Consistent with increased energy reserves, synaptic transmission in hippocampal slices from KD-fed animals was resistant to low glucose. Conclusion These data show that a calorie-restricted KD enhances brain metabolism. We propose an anticonvulsant mechanism of the KD involving mitochondrial biogenesis leading to enhanced alternative energy stores.
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Ercegovac M, Jovic N, Simic T, Beslac-Bumbasirevic L, Sokic D, Djukic T, Savic-Radojevic A, Matic M, Mimic-Oka J, Pljesa-Ercegovac M. Byproducts of protein, lipid and DNA oxidative damage and antioxidant enzyme activities in seizure. Seizure 2010; 19:205-10. [DOI: 10.1016/j.seizure.2010.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 01/25/2010] [Accepted: 02/05/2010] [Indexed: 11/17/2022] Open
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El Sabbagh S, Lebre AS, Bahi-Buisson N, Delonlay P, Soufflet C, Boddaert N, Rio M, Rötig A, Dulac O, Munnich A, Desguerre I. Epileptic phenotypes in children with respiratory chain disorders. Epilepsia 2010; 51:1225-35. [PMID: 20196775 DOI: 10.1111/j.1528-1167.2009.02504.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Epilepsy is a commonly reported but rarely described clinical hallmark of mitochondrial respiratory chain defects (RCDs) with encephalopathy. METHODS From 1990-2006 we collected data about 56 children with RCD (single, n = 24 or multiple, n = 20 mitochondrial complex deficiencies; mtDNA mutation, n = 11; mtDNA depletion n = 10 of 21; and nuclear gene mutation n = 11). Epileptic features were reviewed retrospectively. RESULTS First seizures were frequently (47 patients, 82.5%) preceded by failure to thrive, psychomotor delay, ataxia, or multisystemic dysfunction. Sixty percent of the patients had several seizure types. Six age-related epilepsy phenotypes could be identified: status epilepticus complicating neonatal multivisceral deficiency (2 patients), neonatal myoclonic encephalopathy (3 patients), infantile spasms (8 patients), refractory or recurrent status epilepticus (21 patients), epilepsia partialis continua (4 patients), and myoclonic epilepsy (18 patients). Except for infantile spasms, epilepsy was difficult to control in most patients (95%). Valproate was administered to 25 patients, one of whom developed acute liver failure 6 days later. Twenty-two patients (45%) died, half of them within 9 months from the onset of epilepsy. DISCUSSION In RCD, epilepsy is not only difficult to control but its occurrence often indicates a severe turn in the course of the disease. For one-third of the patients, classical biochemical measures failed to reveal any abnormality and RCD could be detected in the liver only.
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Abstract
Epilepsy is characterized by both neuronal and astroglial dysfunction. The endogenous anticonvulsant adenosine, the level of which is largely controlled by astrocytes, might provide a crucial link between astrocyte and neuron dysfunction in epilepsy. Here we have studied astrogliosis, a hallmark of the epileptic brain, adenosine dysfunction and the emergence of spontaneous seizures in a comprehensive approach that includes a new mouse model of focal epileptogenesis, mutant mice with altered brain levels of adenosine, and mice lacking adenosine A1 receptors. In wild-type mice, following a focal epileptogenesis-precipitating injury, astrogliosis, upregulation of the adenosine-removing astrocytic enzyme adenosine kinase (ADK), and spontaneous seizures coincide in a spatio-temporally restricted manner. Importantly, these spontaneous seizures are mimicked by untreated transgenic mice that either overexpress ADK in brain or lack A1 receptors. Conversely, mice with reduced ADK in the forebrain do not develop either astrogliosis or spontaneous seizures. Our studies define ADK as a crucial upstream regulator of A1 receptor-mediated modulation of neuronal excitability, and support the ADK hypothesis of epileptogenesis in which upregulation of ADK during astrogliosis provides a crucial link between astrocyte and neuron dysfunction in epilepsy. These findings define ADK as rational target for therapeutic intervention.
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Brawek B, Löffler M, Wagner K, Huppertz HJ, Wendling AS, Weyerbrock A, Jackisch R, Feuerstein TJ. Reactive oxygen species (ROS) in the human neocortex: role of aging and cognition. Brain Res Bull 2009; 81:484-90. [PMID: 19854245 DOI: 10.1016/j.brainresbull.2009.10.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 10/14/2009] [Accepted: 10/15/2009] [Indexed: 12/14/2022]
Abstract
Reactive oxygen species (ROS), formed during normal aerobic metabolism, are involved in signal transduction and cognitive functions, but highly increased ROS concentrations may also have detrimental effects. The aim of the present study was to investigate whether aging and cognitive functions are associated with ROS generation in human neocortex obtained from neurosurgical patients. ROS formation in mitochondria from fresh and re-thawed neocortical specimens was measured by monitoring ROS-mediated conversion of dihydrorhodamine 123 to fluorescent rhodamine 123. The validity of this technique was characterized in rat brain mitochondria. The increase in the concentration-response curve of the complex I inhibitor rotenone on ROS generation, as measured by rhodamine 123 (Rh123) fluorescence, was much more pronounced than that of rotenone on mitochondrial [(3)H]-choline uptake [which indicates changes in the mitochondrial membrane potential (DeltaPsi(M))]. Thus, mitochondrial ROS generation can be shown by Rh123 fluorescence although this fluorescence may also reflect changes in DeltaPsi(M) to some extent. ROS formation in human brain mitochondria positively correlated with the age of patients. Moreover, an age-corrected positive correlation of ROS formation with presurgical cognitive performance was observed. Our data suggest a mild increase in ROS formation with aging possibly reflecting a physiological compensation of mitochondrial function. Furthermore, higher cognitive performances in tests of executive functions may be paralleled by slightly increased ROS levels.
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Affiliation(s)
- Bianca Brawek
- Section of Clinical Neuropharmacology, Department of Neurosurgery, University of Freiburg, D-79106 Freiburg, Germany
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Cystatin B deficiency sensitizes neurons to oxidative stress in progressive myoclonus epilepsy, EPM1. J Neurosci 2009; 29:5910-5. [PMID: 19420257 DOI: 10.1523/jneurosci.0682-09.2009] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The progressive myoclonus epilepsies, featuring the triad of myoclonus, seizures, and ataxia, comprise a large group of inherited neurodegenerative diseases that remain poorly understood and refractory to treatment. The Cystatin B gene is mutated in one of the most common forms of progressive myoclonus epilepsy, Unverricht-Lundborg disease (EPM1). Cystatin B knockout in a mouse model of EPM1 triggers progressive degeneration of cerebellar granule neurons. Here, we report impaired redox homeostasis as a key mechanism by which Cystatin B deficiency triggers neurodegeneration. Oxidative stress induces the expression of Cystatin B in cerebellar granule neurons, and EPM1 patient-linked mutation of the Cystatin B gene promoter impairs oxidative stress induction of Cystatin B transcription. Importantly, Cystatin B knockout or knockdown sensitizes cerebellar granule neurons to oxidative stress-induced cell death. The Cystatin B deficiency-induced predisposition to oxidative stress in neurons is mediated by the lysosomal protease Cathepsin B. We uncover evidence of oxidative damage, reflected by depletion of antioxidants and increased lipid peroxidation, in the cerebellum of Cystatin B knock-out mice in vivo. Collectively, our findings define a pathophysiological mechanism in EPM1, whereby Cystatin B deficiency couples oxidative stress to neuronal death and degeneration, and may thus provide the basis for novel treatment approaches for the progressive myoclonus epilepsies.
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Lonnqvist T, Paetau A, Valanne L, Pihko H. Recessive twinkle mutations cause severe epileptic encephalopathy. Brain 2009; 132:1553-62. [DOI: 10.1093/brain/awp045] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kudin AP, Zsurka G, Elger CE, Kunz WS. Mitochondrial involvement in temporal lobe epilepsy. Exp Neurol 2009; 218:326-32. [PMID: 19268667 DOI: 10.1016/j.expneurol.2009.02.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/13/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
Abstract
Mitochondrial dysfunction has been identified as a potential cause of epileptic seizures and therapy-resistant forms of severe epilepsy. Thus, a broad variety of mutation in mitochondrial DNA or nuclear genes leading to the impairment of mitochondrial respiratory chain or of mitochondrial ATP synthesis has been associated with epileptic phenotypes. Additionally, with a variety of different methods impaired mitochondrial function has been reported for the seizure focus of patients with temporal lobe epilepsy and Ammon's horn sclerosis and of animal models of temporal lobe epilepsy. Since mitochondrial oxidative phosphorylation provides the major source of ATP in neurons and mitochondria participate in cellular Ca(2+) homeostasis, their dysfunction strongly affects neuronal excitability and synaptic transmission, which is proposed to be highly relevant for seizure generation. Additionally, mitochondrial dysfunction is known to trigger neuronal cell death, which is a prominent feature of therapy-resistant temporal lobe epilepsy. Therefore, mitochondria have to be considered as promising targets for neuroprotective strategies in epilepsy.
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Affiliation(s)
- Alexei P Kudin
- Department of Epileptology, University Bonn Medical Center, Germany
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