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Tripathi S, Nathan CL, Tate MC, Horbinski CM, Templer JW, Rosenow JM, Sita TL, James CD, Deneen B, Miller SD, Heimberger AB. The immune system and metabolic products in epilepsy and glioma-associated epilepsy: emerging therapeutic directions. JCI Insight 2024; 9:e174753. [PMID: 38193532 PMCID: PMC10906461 DOI: 10.1172/jci.insight.174753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024] Open
Abstract
Epilepsy has a profound impact on quality of life. Despite the development of new antiseizure medications (ASMs), approximately one-third of affected patients have drug-refractory epilepsy and are nonresponsive to medical treatment. Nearly all currently approved ASMs target neuronal activity through ion channel modulation. Recent human and animal model studies have implicated new immunotherapeutic and metabolomic approaches that may benefit patients with epilepsy. In this Review, we detail the proinflammatory immune landscape of epilepsy and contrast this with the immunosuppressive microenvironment in patients with glioma-related epilepsy. In the tumor setting, excessive neuronal activity facilitates immunosuppression, thereby contributing to subsequent glioma progression. Metabolic modulation of the IDH1-mutant pathway provides a dual pathway for reversing immune suppression and dampening seizure activity. Elucidating the relationship between neurons and immunoreactivity is an area for the prioritization and development of the next era of ASMs.
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Affiliation(s)
- Shashwat Tripathi
- Department of Neurological Surgery
- Malnati Brain Tumor Institute of the Robert H. Lurie Comprehensive Cancer Center
| | | | | | - Craig M. Horbinski
- Malnati Brain Tumor Institute of the Robert H. Lurie Comprehensive Cancer Center
- Department of Pathology, and
| | | | | | - Timothy L. Sita
- Department of Neurological Surgery
- Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Charles D. James
- Department of Neurological Surgery
- Malnati Brain Tumor Institute of the Robert H. Lurie Comprehensive Cancer Center
| | - Benjamin Deneen
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Stephen D. Miller
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Amy B. Heimberger
- Department of Neurological Surgery
- Malnati Brain Tumor Institute of the Robert H. Lurie Comprehensive Cancer Center
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2
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Grens K, Church KM, Diehl E, Hunter SE, Tatton-Brown K, Kiernan J, Delagrammatikas CG. Epilepsy and overgrowth-intellectual disability syndromes: a patient organization perspective on collaborating to accelerate pathways to treatment. THERAPEUTIC ADVANCES IN RARE DISEASE 2024; 5:26330040241254123. [PMID: 38827639 PMCID: PMC11143874 DOI: 10.1177/26330040241254123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 04/18/2024] [Indexed: 06/04/2024]
Abstract
Overgrowth-intellectual disability (OGID) syndromes are a collection of rare genetic disorders with overlapping clinical profiles. In addition to the cardinal features of general overgrowth (height and/or head circumference at least two standard deviations above the mean) and some degree of intellectual disability, the OGID syndromes are often associated with neurological anomalies including seizures. In an effort to advance research in directions that will generate meaningful treatments for people with OGID syndromes, a new collaborative partnership called the Overgrowth Syndromes Alliance (OSA) formed in 2023. By taking a phenotype-first approach, OSA aims to unite research and patient communities traditionally siloed by genetic disorder. OSA has galvanized OGID patient organizations around shared interests and developed a research roadmap to identify and address our community's greatest unmet needs. Here, we describe the literature regarding seizures among those with overgrowth syndromes and present the OSA Research Roadmap. This patient-driven guide outlines the milestones essential to reaching the outcome of effective treatments for OGID syndromes and offers resources for reaching those milestones.
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Affiliation(s)
- Kerry Grens
- Tatton Brown Rahman Syndrome Community, Stanfordville, NY, USA
| | - Kit M. Church
- Tatton Brown Rahman Syndrome Community, Stanfordville, NY, USA
| | - Eric Diehl
- Tatton Brown Rahman Syndrome Community, Stanfordville, NY, USA
| | - Senyene E. Hunter
- Division of Pediatric Neurology, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Katrina Tatton-Brown
- St George’s University Hospitals NHS Foundation Trust, London, UK
- St George’s University of London, London, UK
| | - Jill Kiernan
- Tatton Brown Rahman Syndrome Community, Stanfordville, NY, USA
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3
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Rastin C, Schenkel LC, Sadikovic B. Complexity in Genetic Epilepsies: A Comprehensive Review. Int J Mol Sci 2023; 24:14606. [PMID: 37834053 PMCID: PMC10572646 DOI: 10.3390/ijms241914606] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Epilepsy is a highly prevalent neurological disorder, affecting between 5-8 per 1000 individuals and is associated with a lifetime risk of up to 3%. In addition to high incidence, epilepsy is a highly heterogeneous disorder, with variation including, but not limited to the following: severity, age of onset, type of seizure, developmental delay, drug responsiveness, and other comorbidities. Variable phenotypes are reflected in a range of etiologies including genetic, infectious, metabolic, immune, acquired/structural (resulting from, for example, a severe head injury or stroke), or idiopathic. This review will focus specifically on epilepsies with a genetic cause, genetic testing, and biomarkers in epilepsy.
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Affiliation(s)
- Cassandra Rastin
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
| | - Laila C. Schenkel
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
| | - Bekim Sadikovic
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
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4
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Zeibich R, Kwan P, J. O’Brien T, Perucca P, Ge Z, Anderson A. Applications for Deep Learning in Epilepsy Genetic Research. Int J Mol Sci 2023; 24:14645. [PMID: 37834093 PMCID: PMC10572791 DOI: 10.3390/ijms241914645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Epilepsy is a group of brain disorders characterised by an enduring predisposition to generate unprovoked seizures. Fuelled by advances in sequencing technologies and computational approaches, more than 900 genes have now been implicated in epilepsy. The development and optimisation of tools and methods for analysing the vast quantity of genomic data is a rapidly evolving area of research. Deep learning (DL) is a subset of machine learning (ML) that brings opportunity for novel investigative strategies that can be harnessed to gain new insights into the genomic risk of people with epilepsy. DL is being harnessed to address limitations in accuracy of long-read sequencing technologies, which improve on short-read methods. Tools that predict the functional consequence of genetic variation can represent breaking ground in addressing critical knowledge gaps, while methods that integrate independent but complimentary data enhance the predictive power of genetic data. We provide an overview of these DL tools and discuss how they may be applied to the analysis of genetic data for epilepsy research.
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Affiliation(s)
- Robert Zeibich
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia; (R.Z.); (P.K.); (T.J.O.); (P.P.)
| | - Patrick Kwan
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia; (R.Z.); (P.K.); (T.J.O.); (P.P.)
- Department of Neurology, Alfred Health, Melbourne, VIC 3004, Australia
- Department of Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Terence J. O’Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia; (R.Z.); (P.K.); (T.J.O.); (P.P.)
- Department of Neurology, Alfred Health, Melbourne, VIC 3004, Australia
- Department of Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia; (R.Z.); (P.K.); (T.J.O.); (P.P.)
- Department of Neurology, Alfred Health, Melbourne, VIC 3004, Australia
- Department of Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, VIC 3084, Australia
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, The University of Melbourne, Melbourne, VIC 3084, Australia
| | - Zongyuan Ge
- Faculty of Engineering, Monash University, Melbourne, VIC 3800, Australia;
- Monash-Airdoc Research, Monash University, Melbourne, VIC 3800, Australia
| | - Alison Anderson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC 3800, Australia; (R.Z.); (P.K.); (T.J.O.); (P.P.)
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3052, Australia
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5
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DNA Methylation Description of Hippocampus, Cortex, Amygdala, and Blood of Drug-Resistant Temporal Lobe Epilepsy. Mol Neurobiol 2023; 60:2070-2085. [PMID: 36602701 DOI: 10.1007/s12035-022-03180-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023]
Abstract
Epigenetic changes such as DNA methylation were observed in drug-resistant temporal lobe epilepsy (DR-TLE), a disease that affects 25-30% of epilepsy patients. The main objective is to simultaneously describe DNA methylation patterns associated with DR-TLE in hippocampus, amygdala, surrounding cortex to the epileptogenic zone (SCEZ), and peripheral blood. An Illumina Infinium MethylationEPIC BeadChip array was performed in 19 DR-TLE patients and 10 postmortem non-epileptic controls. Overall, 32, 59, and 3210 differentially methylated probes (DMPs) were associated with DR-TLE in the hippocampus, amygdala, and SCEZ, respectively. These DMP-affected genes were involved in neurotrophic and calcium signaling in the hippocampus and voltage-gated channels in SCEZ, among others. One of the hippocampus DMPs (cg26834418 (CHORDC1)) showed a strong blood-brain correlation with BECon and IMAGE-CpG, suggesting that it could be a potential surrogate peripheral biomarker of DR-TLE. Moreover, in three of the top SCEZ's DMPs (SHANK3, SBF1, and MCF2L), methylation status was verified with methylation-specific qPCR. The differentially methylated CpGs were classified in DMRs: 2 in the hippocampus, 12 in the amygdala, and 531 in the SCEZ. We identified genes that had not been associated to DR-TLE so far such as TBX5, EXOC7, and WRHN. The area with more DMPs associated with DR-TLE was the SCEZ, some of them related to voltage-gated channels. The DMPs found in the amygdala were involved in inflammatory processes. We also found a potential surrogate peripheral biomarker of DR-TLE. Thus, these results provide new insights into epigenetic modifications involved in DR-TLE.
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6
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Martins-Ferreira R, Leal B, Chaves J, Li T, Ciudad L, Rangel R, Santos A, Martins da Silva A, Pinho Costa P, Ballestar E. Epilepsy progression is associated with cumulative DNA methylation changes in inflammatory genes. Prog Neurobiol 2022; 209:102207. [DOI: 10.1016/j.pneurobio.2021.102207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/02/2021] [Accepted: 12/14/2021] [Indexed: 01/09/2023]
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Zhang X, Zhang J, Wang Y, Wang M, Tang M, Lin Y, Liu Q. Epigenetic Modifications and Neurodegenerative Disorders: A Biochemical Perspective. ACS Chem Neurosci 2022; 13:177-184. [PMID: 35000390 DOI: 10.1021/acschemneuro.1c00701] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Methylations in living cells are methyl groups attached to amino acids, DNA, RNA, and so on. However, their biochemical roles have not been fully defined. A theory has been postulated that methylation leads to hyperconjugation, and the electron-donating feature weakens a nearby chemical bond, which increases the bond length of C4-N4 of 5-methylcytosine, therefore weakening the C4-N4 bond and resulting in stronger protonation or hydrogen bonding of the N4 nitrogen atom. Protonation can give rise to the generation of mutagenic and carcinogenic strong acids such as HCl, which are also capable of solubilizing stressful, insoluble, and stiff salts. Insoluble and rigid salts such as calcium oxalate and/or calcium phosphate were recently proposed as a primary cause of some neurodegenerative disorders. Protonation of nitrogen atoms in 5-methylcytosine enhances the interaction with negatively charged phosphate groups and contributes to the formation of compact heterochromatin. The electronegativity of the oxygen atoms in the modifications of 5-hydroxymethylcytosine or 5-formylcytosine can shorten the lengths of adjacent bonds with no increase of cation affinity in N4. The carboxyl group in 5-carboxylcytosine is a weak acid capable of antagonizing mutagenic HCl and modestly helping solubilize insoluble salts. Electron delocalization of the methyl group in N4-methylcytosine results in a lower affinity of N4 to cations. The positive charge at N3 in the resonance structure of 3-methylcytosine is lessened by the electron-donating attribute of the methyl group attached to the N3 atom, consequently reducing acid formation. The electron delocalization of three methyl groups decreases the positive charge in the amino nitrogen in the side group of lysine 4 in histone H3, weakening interactions with phosphate groups and consequently activating gene expression. The carbonyl oxygen in 8-oxo-7,8-dihydroguanine draws protons and accumulates HCl, accounting for its moderate mutation propensity and potential capacity to solubilize stiff salts. The biochemical insight will further our understanding on the crosstalk of genetics and epigenetics in the etiology of neurodegenerative diseases.
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Affiliation(s)
- Xiaoxiao Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Yunnan Key Laboratory of Stem Cell and Regenerative Medicine, Biomedical Engineering Research Center, Kunming Medical University, Kunming 650500, China
| | - Jiaming Zhang
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yuchuan Wang
- Hebei Key Laboratory for Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan, Hebei 063210, China
| | - Minji Wang
- School of Chemistry and Molecular Engineering, East China Normal University, Minhang Campus, 3663 Zhongshan Rd North, Shanghai 200062, China
| | - Man Tang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuhan Lin
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Qiuyun Liu
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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8
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Pagni S, Mills JD, Frankish A, Mudge JM, Sisodiya SM. Non-coding regulatory elements: Potential roles in disease and the case of epilepsy. Neuropathol Appl Neurobiol 2021; 48:e12775. [PMID: 34820881 DOI: 10.1111/nan.12775] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/04/2021] [Accepted: 11/16/2021] [Indexed: 12/27/2022]
Abstract
Non-coding DNA (ncDNA) refers to the portion of the genome that does not code for proteins and accounts for the greatest physical proportion of the human genome. ncDNA includes sequences that are transcribed into RNA molecules, such as ribosomal RNAs (rRNAs), microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and un-transcribed sequences that have regulatory functions, including gene promoters and enhancers. Variation in non-coding regions of the genome have an established role in human disease, with growing evidence from many areas, including several cancers, Parkinson's disease and autism. Here, we review the features and functions of the regulatory elements that are present in the non-coding genome and the role that these regions have in human disease. We then review the existing research in epilepsy and emphasise the potential value of further exploring non-coding regulatory elements in epilepsy. In addition, we outline the most widely used techniques for recognising regulatory elements throughout the genome, current methodologies for investigating variation and the main challenges associated with research in the field of non-coding DNA.
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Affiliation(s)
- Susanna Pagni
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St Peter, UK
| | - James D Mills
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St Peter, UK.,Amsterdam UMC, Department of (Neuro)Pathology, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, Netherlands
| | - Adam Frankish
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, UK
| | - Jonathan M Mudge
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont St Peter, UK
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9
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Abstract
This review explores how different classes of drugs, including those with therapeutic and abuse potential, alter brain functions and behavior via the epigenome. Epigenetics, in its simplest interpretation, is the study of the regulation of a genes' transcriptional potential. The epigenome is established during development but is malleable throughout life by a wide variety of drugs, with both clinical utility and abuse potential. An epigenetic effect can be central to the drug's therapeutic or abuse potential, or it can be independent from the main effect but nevertheless produce beneficial or adverse side effects. Here, I discuss the various epigenetic effects of main pharmacological drug classes, including antidepressants, antiepileptics, and drugs of abuse.
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Affiliation(s)
- Miklos Toth
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA;
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10
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Xiao W, Liu C, Zhong K, Ning S, Hou R, Deng N, Xu Y, Luo Z, Fu Y, Zeng Y, Xiao B, Long H, Long L. CpG methylation signature defines human temporal lobe epilepsy and predicts drug-resistant. CNS Neurosci Ther 2020; 26:1021-1030. [PMID: 32519815 PMCID: PMC7539843 DOI: 10.1111/cns.13394] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Aims Temporal lobe epilepsy (TLE) is the most common focal epilepsy syndrome in adults and frequently develops drug resistance. Studies have investigated the value of peripheral DNA methylation signature as molecular biomarker for diagnosis or prognosis. We aimed to explore methylation biomarkers for TLE diagnosis and pharmacoresistance prediction. Methods We initially conducted genome‐wide DNA methylation profiling in TLE patients, and then selected candidate CpGs in training cohort and validated in another independent cohort by employing machine learning algorithms. Furthermore, nomogram comprising DNA methylation and clinicopathological data was generated to predict the drug response in the entire patient cohort. Lastly, bioinformatics analysis for CpG‐associated genes was performed using Ingenuity Pathway Analysis. Results After screening and validation, eight CpGs were identified for diagnostic biomarker with an area under the curve (AUC) of 0.81 and six CpGs for drug‐resistant prediction biomarker with an AUC of 0.79. The nomogram for drug‐resistant prediction comprised methylation risk score, disease course, seizure frequency, and hippocampal sclerosis, with AUC as high as 0.96. Bioinformatics analysis indicated drug response–related CpGs corresponding genes closely related to DNA methylation. Conclusions This study demonstrates the ability to use peripheral DNA methylation signature as molecular biomarker for epilepsy diagnosis and drug‐resistant prediction.
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Affiliation(s)
- Wenbiao Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Chaorong Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Kuo Zhong
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China
| | - Shangwei Ning
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, China
| | - Rui Hou
- Shanghai Biotechnology Corporation, Shanghai, China
| | - Na Deng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yuchen Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhaohui Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yujiao Fu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yi Zeng
- Department of Geriatrics, Second Xiangya Hospital, Central South University, Changsha, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hongyu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
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11
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Bertogliat MJ, Morris-Blanco KC, Vemuganti R. Epigenetic mechanisms of neurodegenerative diseases and acute brain injury. Neurochem Int 2020; 133:104642. [PMID: 31838024 PMCID: PMC8074401 DOI: 10.1016/j.neuint.2019.104642] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/25/2019] [Accepted: 12/09/2019] [Indexed: 12/22/2022]
Abstract
Epigenetic modifications are emerging as major players in the pathogenesis of neurodegenerative disorders and susceptibility to acute brain injury. DNA and histone modifications act together with non-coding RNAs to form a complex gene expression machinery that adapts the brain to environmental stressors and injury response. These modifications influence cell-level operations like neurogenesis and DNA repair to large, intricate processes such as brain patterning, memory formation, motor function and cognition. Thus, epigenetic imbalance has been shown to influence the progression of many neurological disorders independent of aberrations in the genetic code. This review aims to highlight ways in which epigenetics applies to several commonly researched neurodegenerative diseases and forms of acute brain injury as well as shed light on the benefits of epigenetics-based treatments.
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Affiliation(s)
- Mario J Bertogliat
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA
| | - Kahlilia C Morris-Blanco
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA; William S. Middleton VA Hospital, Madison, WI, USA
| | - Raghu Vemuganti
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA; William S. Middleton VA Hospital, Madison, WI, USA.
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12
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Huang QB, Zhang HW, Liao ZB. Carboxypeptidase A6 Promotes the Proliferation and Migration of Hepatocellular Carcinoma by Up-regulating AKT Signaling Pathway. Curr Med Sci 2019; 39:727-733. [PMID: 31612389 DOI: 10.1007/s11596-019-2098-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/24/2019] [Indexed: 12/19/2022]
Abstract
Hepatocellular carcinoma (HCC) has a poor treatment prognosis and high mortality worldwide. Understanding the molecular mechanism underlying HCC development would benefit the identification of diagnostic biomarkers and the improvement of the treatment strategies. The expression of carboxypeptidase A6 (CPA6) has been reported in epilepsy and febrile seizures rather than in any type of cancers. However, the function of CPA6 expression in HCC is not yet understood. In this study, we aimed to investigate the clinicopathological significance of the expression of CPA6 in HCC and the underlying mechanisms. We observed that the expression of the CPA6 protein was increased significantly in HCC tissues than in paracancerous tissues. To explore its function in HCC, both gain- and loss-of-function studies demonstrated that CPA6 played a vital role in promoting HCC growth and metastasis. When knocking down CPA6 with shRNA, HCC cell proliferation and migration could be suppressed. Meanwhile, CPA6 overexpression could promote proliferation and migration of HLF cells. Moreover, CPA6 could activate AKT serine/threonine kinase (AKT) signaling pathway as confirmed by Western blotting. In conclusion, our study revealed that CPA6 could promote HCC cell proliferation and migration via AKT-mediated signaling pathway. These findings suggest that CPA6 is a promising diagnostic biomarker and therapeutic target to improve the prognosis of HCC.
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Affiliation(s)
- Qi-Bo Huang
- Department of Clinical Medicine, Medical College of Wuhan University of Science and Technology, Wuhan, 430081, China
| | - Hong-Wei Zhang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhi-Bin Liao
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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13
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Mohandas N, Loke YJ, Hopkins S, Mackenzie L, Bennett C, Berkovic SF, Vadlamudi L, Craig JM. Evidence for type-specific DNA methylation patterns in epilepsy: a discordant monozygotic twin approach. Epigenomics 2019; 11:951-968. [DOI: 10.2217/epi-2018-0136] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Aim: Epilepsy is a common neurological disorder characterized by recurrent seizures. We performed epigenetic analyses between and within 15 monozygotic (MZ) twin pairs discordant for focal or generalized epilepsy. Methods: DNA methylation analysis was performed using Illumina Infinium MethylationEPIC arrays, in blood and buccal samples. Results: Differentially methylated regions between epilepsy types associated with PM20D1 and GFPT2 genes in both tissues. Within MZ discordant twin pairs, differentially methylated regions associated with OTX1 and ARID5B genes for generalized epilepsy and TTC39C and DLX5 genes for focal epilepsy. Conclusion: This is the first epigenome-wide association study, utilizing the discordant MZ co-twin model, to deepen our understanding of the neurobiology of epilepsy.
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Affiliation(s)
- Namitha Mohandas
- Environmental & Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Flemington Road, Parkville, Victoria, Australia
| | - Yuk Jing Loke
- Environmental & Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
| | - Stephanie Hopkins
- Environmental & Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
- School of Medicine & Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - Lisa Mackenzie
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Queensland, Australia
| | - Carmen Bennett
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Queensland, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, University of Melbourne, Austin Health, Victoria, Australia
| | - Lata Vadlamudi
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Queensland, Australia
- Royal Brisbane & Women's Hospital, Queensland, Australia
| | - Jeffrey M Craig
- Environmental & Genetic Epidemiology Research, Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Flemington Road, Parkville, Victoria, Australia
- Centre for Molecular & Medical Research, School of Medicine, Deakin University, Geelong, Victoria 3220, Australia
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14
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Genç F, Kara M, Ünal Y, Uygur Küçükseymen E, Biçer Gömceli Y, Kaynar T, Tosun K, Kutlu G. Methylation of cation-chloride cotransporters NKCC1 and KCC2 in patients with juvenile myoclonic epilepsy. Neurol Sci 2019; 40:1007-1013. [PMID: 30759289 DOI: 10.1007/s10072-019-03743-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/30/2019] [Indexed: 10/27/2022]
Abstract
The etiology of juvenile myoclonic epilepsy (JME) is still unknown and the process of elaboration of multiple genetic mechanisms is ongoing. The aim of this study was to investigate the potential role of NKCC1 (SCL12A2) and KCC2 (SCL12A5) in JME by comparing their DNA methylation status in patients with JME versus healthy controls. Forty-nine patients with JME and 39 healthy individuals were compared for DNA methylation at the 5CpG islands. A total of 71 (81%) samples were found to have methylation in the NKCC1 gene, 36 (73%) from patients and 35 (90%) from healthy individuals. Out of the KCC2 samples, 50 (57%) were found to have methylation, 33 (67%) from patients and 17 (44%) from healthy individuals. In patients with JME, methylation of NKCC1 (73%) was lower than its methylation in the controls (90%) (p = 0.047). On the other hand, methylation of KCC2 in patients with JME (67%) was greater than the methylation in the controls (44%) (p = 0.022). Twenty-eight patients were treated with VPA and ongoing medications were not found to be associated with methylation (p > 0.05). In the present study, we determined significantly lower NKCC1 DNA methylation and significantly higher KCC2 DNA methylation levels in patients with JME compared with the healthy controls. This implies that NKCC1 expression can be higher and KCC2 expression can be reduced in affected people. Further studies that investigate the potential effect of DNA methylation mechanisms regulating gene expression on seizure activity and how they change JME network activity will be helpful.
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Affiliation(s)
- Fatma Genç
- Antalya Training and Research Hospital, Department of Neurology, Antalya, Turkey.
| | | | - Yasemin Ünal
- Faculty of Medicine Department of Neurology, Muğla Sıtkı Koçman University, Muğla, Turkey
| | - Elif Uygur Küçükseymen
- Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Taner Kaynar
- Sitogen Biomedical and Laboratory Systems Industrial Trade Limited Company, Zümrütevler mah. Hanımeli cad. Aktunç İşmerkezi No:13/1 Maltepe, İstanbul, Turkey
| | | | - Gülnihal Kutlu
- Faculty of Medicine Department of Neurology and Clinical Neurophysiology, Muğla Sıtkı Koçman University, Muğla, Turkey
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Navarrete-Modesto V, Orozco-Suárez S, Feria-Romero IA, Rocha L. The molecular hallmarks of epigenetic effects mediated by antiepileptic drugs. Epilepsy Res 2019; 149:53-65. [DOI: 10.1016/j.eplepsyres.2018.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/16/2018] [Accepted: 11/14/2018] [Indexed: 02/06/2023]
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Malov AG, Kulesh AA, Vshivkov MI. Familial temporal lobe epilepsy 5 with vestibular seizures (a case report). Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:65-69. [DOI: 10.17116/jnevro201911911265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Balestrini S, Sisodiya SM. Personalized treatment in the epilepsies: challenges and opportunities. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2018. [DOI: 10.1080/23808993.2018.1486189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, and Epilepsy Society, Chalfont-St-Peter, Bucks, United Kingdom
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, and Epilepsy Society, Chalfont-St-Peter, Bucks, United Kingdom
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Abstract
Fever-associated seizures or epilepsy (FASE) is primarily characterised by the occurrence of a seizure or epilepsy usually accompanied by a fever. It is common in infants and children, and generally includes febrile seizures (FS), febrile seizures plus (FS+), Dravet syndrome (DS) and genetic epilepsy with febrile seizures plus (GEFSP). The aetiology of FASE is unclear. Genetic factors may play crucial roles in FASE. Mutations in certain genes may cause a wide spectrum of phenotypical overlap ranging from isolated FS, FS+ and GEFSP to DS. Synapse-associated proteins, postsynaptic GABAA receptor, and sodium channels play important roles in synaptic transmission. Mutations in these genes may involve in the pathogenesis of FASE. Elevated temperature promotes synaptic vesicle (SV) recycling and enlarges SV size, which may enhance synaptic transmission and contribute to FASE occurring. This review provides an overview of the loci, genes, underlying pathogenesis and the fever-inducing effect of FASE. It may provide a more comprehensive understanding of pathogenesis and contribute to the clinical diagnosis of FASE.
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Pathak S, Miller J, Morris EC, Stewart WCL, Greenberg DA. DNA methylation of the BRD2 promoter is associated with juvenile myoclonic epilepsy in Caucasians. Epilepsia 2018; 59:1011-1019. [PMID: 29608786 DOI: 10.1111/epi.14058] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2018] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Juvenile myoclonic epilepsy (JME) is a common adolescent-onset genetic generalized epilepsy (GGE) syndrome. Multiple linkage and association studies have found that BRD2 influences the expression of JME. The BRD2-JME connection is further corroborated by our murine model; Brd2 haploinsufficiency produces characteristics that typify the clinical hallmarks of JME. Neither we, nor several large-scale studies of JME, found JME-related BRD2 coding mutations. Therefore, we investigated noncoding BRD2 regions, seeking the origin of BRD2's JME influence. BRD2's promoter harbors a JME-associated single nucleotide polymorphism (rs3918149) and a CpG (C-phosphate-G dinucleotides) island (CpG76), making it a potential "hotspot" for JME-associated epigenetic variants. Methylating promoter CpG sites causes gene silencing, often resulting in reduced gene expression. We tested for differences in DNA methylation at CpG76 in 3 different subgroups: (1) JME patients versus their unaffected family members, (2) JME versus patients with other forms of GGE, and (3) Caucasian versus non-Caucasian JME patients. METHODS We used DNA pyrosequencing to analyze the methylation status of 10 BRD2 promoter CpG sites in lymphoblastoid cells from JME patients of Caucasian and non-Caucasian origin, unaffected family members, and also non-JME GGE patients. We also measured global methylation levels and DNA methyl transferase 1 (DNMT1) transcript expression in JME families by standard methods. RESULTS CpG76 is highly methylated in JME patients compared to unaffected family members. In families with non-JME GGE, we found no relationship between promoter methylation and epilepsy. In non-Caucasian JME families, promoter methylation was mostly not associated with epilepsy. This makes the BRD2 promoter a JME-specific, ethnicity-specific, differentially methylated region. Global methylation was constant across groups. SIGNIFICANCE BRD2 promoter methylation in JME, and the lack of methylation in unaffected relatives, in non-JME GGE patients, and in non-Caucasian JME, demonstrate that methylation specificity is a possible seizure susceptibility motif in JME risk and suggests JME therapeutics targeting BRD2.
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Affiliation(s)
- Shilpa Pathak
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - James Miller
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - Emily C Morris
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - William C L Stewart
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - David A Greenberg
- Battelle Center for Mathematical Medicine, Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
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Kiese K, Jablonski J, Hackenbracht J, Wrosch JK, Groemer TW, Kornhuber J, Blümcke I, Kobow K. Epigenetic control of epilepsy target genes contributes to a cellular memory of epileptogenesis in cultured rat hippocampal neurons. Acta Neuropathol Commun 2017; 5:79. [PMID: 29089052 PMCID: PMC5664434 DOI: 10.1186/s40478-017-0485-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/25/2017] [Indexed: 02/01/2023] Open
Abstract
Hypersynchronous neuronal excitation manifests clinically as seizure (ictogenesis), and may recur spontaneously and repetitively after a variable latency period (epileptogenesis). Despite tremendous research efforts to describe molecular pathways and signatures of epileptogenesis, molecular pathomechanisms leading to chronic epilepsy remain to be clarified. We hypothesized that epigenetic modifications may form the basis for a cellular memory of epileptogenesis, and used a primary neuronal cell culture model of the rat hippocampus to study the translation of massive neuronal excitation into persisting changes of epigenetic signatures and pro-epileptogenic target gene expression. Increased spontaneous activation of cultured neurons was detected 3 and 7 days after stimulation with 10 μM glutamate when compared to sham-treated time-matched controls using calcium-imaging in vitro. Chromatin-immunoprecipitation experiments revealed short-term (3 h, 7 h, and 24 h) and long-term (3 d and 2 weeks) changes in histone modifications, which were directly linked to decreased expression of two selected epilepsy target genes, e.g. excitatory glutamate receptor genes Gria2 and Grin2a. Increased promoter methylation observed 4 weeks after glutamate stimulation at respective genes suggested long-term repression of Gria2 and Grin2a genes. Inhibition of glutamatergic activation or blocking the propagation of action potentials in cultured neurons rescued altered gene expression and regulatory epigenetic modifications. Our data support the concept of a cellular memory of epileptogenesis and persisting epigenetic modifications of epilepsy target genes, which are able to turn normal into pro-epileptic neurons and circuits.
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Abstract
Epilepsy is a common and devastating neurological disorder characterized by recurrent and unprovoked spontaneous seizures. One leading hypothesis for the development and progression of epilepsy is that large-scale changes in gene transcription and protein expression contribute to aberrant network restructuring and hyperexcitability, resulting in the genesis of repeated seizures. Current research shows that epigenetic mechanisms, including posttranslational alterations to the proteins around which DNA is coiled, chemical modifications to DNA, and the activity of various noncoding RNA molecules exert important influences on these gene networks in experimental epilepsy. Key findings from animal models have been replicated in humans using brain tissue obtained from living patients at the time of neurosurgical resection for pharmacoresistant epilepsy. These findings have spurred efforts to target epigenetic processes to disrupt or modify epilepsy in experimental models with varying degrees of success. In this review, we will (1) summarize the epigenetic mechanisms implicated in epileptogenesis and epilepsy, (2) explore the influence of metabolic factors on epigenetic mechanisms, and (3) assess the potential of using epigenetic markers to support diagnosis and prognosis. Translation of these findings may guide the development of molecular biomarkers and novel therapeutics for prevention or modification of epileptic disorders.
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Affiliation(s)
- Rebecca M. Hauser
- Evelyn F. McKnight Brain Institute, Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - David C. Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Farah D. Lubin
- Evelyn F. McKnight Brain Institute, Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, USA
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22
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Long HY, Feng L, Kang J, Luo ZH, Xiao WB, Long LL, Yan XX, Zhou L, Xiao B. Blood DNA methylation pattern is altered in mesial temporal lobe epilepsy. Sci Rep 2017; 7:43810. [PMID: 28276448 PMCID: PMC5343463 DOI: 10.1038/srep43810] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/31/2017] [Indexed: 12/28/2022] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is a common epileptic disorder; little is known whether it is associated with peripheral epigenetic changes. Here we compared blood whole genomic DNA methylation pattern in MTLE patients (n = 30) relative to controls (n = 30) with the Human Methylation 450 K BeadChip assay, and explored genes and pathways that were differentially methylated using bioinformatics profiling. The MTLE and control groups showed significantly different (P < 1.03e-07) DNA methylation at 216 sites, with 164 sites involved hyper- and 52 sites hypo- methylation. Two hyper- and 32 hypo-methylated sites were associated with promoters, while 87 hyper- and 43 hypo-methylated sites corresponded to coding regions. The differentially methylated genes were largely related to pathways predicted to participate in anion binding, oxidoreductant activity, growth regulation, skeletal development and drug metabolism, with the most distinct ones included SLC34A2, CLCN6, CLCA4, CYP3A43, CYP3A4 and CYP2C9. Among the MTLE patients, panels of genes also appeared to be differentially methylated relative to disease duration, resistance to anti-epileptics and MRI alterations of hippocampal sclerosis. The peripheral epigenetic changes observed in MTLE could be involved in certain disease-related modulations and warrant further translational investigations.
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Affiliation(s)
- Hong-Yu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jin Kang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhao-Hui Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Wen-Biao Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Li-Li Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine, Changsha, Hunan 410013, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan 410008, China
| | - Luo Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
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23
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Kobow K, Blümcke I. Epigenetics in epilepsy. Neurosci Lett 2017; 667:40-46. [PMID: 28111355 DOI: 10.1016/j.neulet.2017.01.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/02/2017] [Accepted: 01/06/2017] [Indexed: 11/19/2022]
Abstract
Approximately 50 million people have epilepsy, making it the most common chronic and severe neurological disease worldwide, with increased risk of mortality and psychological and socioeconomic consequences impairing quality of life. More than 30% of patients with epilepsy have inadequate control of their seizures with drug therapy. Any structural brain lesion can provoke epilepsy. However, progression of seizure activity as well as the development of drug-resistance remains difficult to predict, irrespective of the underlying epileptogenic condition, i.e., traumatic brain injury, developmental brain lesions, brain tumors or genetic inheritance. Mutated DNA sequences in genes encoding for ion channels or neurotransmitter receptors have been identified in hereditary focal or generalized epilepsies, but genotype-phenotype correlations are poor, arguing for additional factors determining the effect of a genetic predisposition. The dynamics of epigenetic mechanisms (e.g. DNA methylation, histone modifications, chromatin remodelling, and non-coding RNAs) provide likely explanations for common features in epilepsy and other complex diseases, including late onset, parent-of-origin effects, discordance of monozygotic twins, and fluctuation of symptoms. In addition, many focal epilepsies, including focal cortical dysplasias (FCDs), glio-neuronal tumors (e.g. ganglioglioma), or temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), do not seem to primarily associate with hereditary traits, suggesting other pathogenic mechanisms. Herein we will discuss the many faces of the epigenetic machinery, which provides powerful tools and mechanisms to propagate epileptogenicity and likely also contribute to the epileptogenic memory in chronic and difficult-to-treat epilepsies.
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Affiliation(s)
- K Kobow
- Department of Neuropathology, University Hospital Erlangen, Germany.
| | - I Blümcke
- Department of Neuropathology, University Hospital Erlangen, Germany
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24
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Wang Z, Zhang Y, Fang J, Yu F, Heng D, Fan Y, Xu J, Peng B, Liu W, Han S, He X. Decreased Methylation Level of H3K27me3 Increases Seizure Susceptibility. Mol Neurobiol 2016; 54:7343-7352. [PMID: 27815838 DOI: 10.1007/s12035-016-0197-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/11/2016] [Indexed: 01/01/2023]
Abstract
Epigenetic modifications including histone modifications are associated with seizure development and epileptogenesis; however, its underlying mechanism remains to be elucidated. Dipeptidyl peptidase 4 (DPP4) and IL6 are identified as febrile seizure (FS)-related genes using gene microarray analysis in hyperthermia prone (HP) rats. This purpose of the study focused on exploring whether epigenetic modifications marker histone H3 lysine 27 trimethylation (H3K27me3)-regulated DPP4 and IL6 expression further affected seizures development. Herein, we reported broad between-group differences in the global levels of H3K27me3 with increased seizure severity in vivo. Using chromatin immunoprecipitation (ChIP), we identified markedly decreased H3K27me3 enrichment at their promoters of DPP4 and IL6 in vivo. We further showed that hyperthermia significantly decreased protein levels of H3K27me3, increased mRNA levels of DPP4 and IL6 by decreasing H3K27me3 enrichment at their promoters of DPP4 and IL6 in vitro. Importantly, H3K27me3 loss via enhancer of zeste homolog 2 (EZH2) knockdown promoted expression of DPP4 and IL6 via the same mechanism in vitro. EZH2 knockdown also increased neuronal firing frequency in vitro and FS susceptibility in vivo companied with upregulation expression of DPP4 and IL6. Taken together, our study provided the first evidence that hyperthermia-induced decreased of H3K27me3 promoted seizure susceptibility via regulating the expression pattern of DPP4 and IL6. These findings suggested that the methylation level of H3K27me3 might be a key regulator of seizure susceptibility.
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Affiliation(s)
- Zhongcheng Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Yusong Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Jian Fang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Fang Yu
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Duanhe Heng
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Yuanteng Fan
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Jian Xu
- Weifang Maternity and Child Hospital, Weifang, China
| | - Biwen Peng
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China.
| | - Xiaohua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China.
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25
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Wang JG, Cai Q, Zheng J, Dong YS, Li JJ, Li JC, Hao GZ, Wang C, Wang JL. Epigenetic Suppression of GADs Expression is Involved in Temporal Lobe Epilepsy and Pilocarpine-Induced Mice Epilepsy. Neurochem Res 2016; 41:1751-60. [PMID: 27220336 DOI: 10.1007/s11064-016-1891-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/06/2016] [Accepted: 03/17/2016] [Indexed: 01/02/2023]
Abstract
Recent studies have shown that histone acetylation is involved with the regulation of enzyme glutamate decarboxylases (GADs), including GAD67 and GAD65. Here, we investigated the histone acetylation modifications of GADs in the pathogenesis of epilepsy and explored the therapeutic effect of a novel second-generation histone deacetylase inhibitor (HDACi) JNJ-26481585 in epilepsy animals. We revealed the suppression of GADs protein and mRNA level, and histone hypoacetylation in patients with temporal lobe epilepsy and pilocarpine-induced epilepsy mice model. Double-immunofluorescence also indicated that the hypoacetyl-H3 was located in hippocampal GAD67/GAD65 positive neurons in epilepsy mice. JNJ-26481585 significantly reversed the decrease of the GAD67/GAD65 both protein and mRNA levels, and the histone hypoacetylation of GABAergic neurons in epilepsy mice. Meanwhile, single-cell real-time PCR performed in GFP-GAD67/GAD65 transgenic mice demonstrated that JNJ-26481585 induced increase of GAD67/GAD65 mRNA level in GABAergic neurons. Furthermore, JNJ-26481585 significantly alleviated the epileptic seizures in mice model. Together, our findings demonstrate inhibition of GADs gene via histone acetylation plays an important role in the pathgenesis of epilepsy, and suggest JNJ-26481585 as a promising therapeutic strategy for epilepsy.
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Affiliation(s)
- Jin-Gang Wang
- Department of Neurosurgery, The 463rd Hospital of PLA, Shenyang, Liaoning, 110042, People's Republic of China
| | - Qing Cai
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Jun Zheng
- Department of Neurosurgery, The 463rd Hospital of PLA, Shenyang, Liaoning, 110042, People's Republic of China
| | - Yu-Shu Dong
- Department of Neurosurgery, General Hospital of Shenyang Military Command Area, Shenyang, Liaoning, 110016, People's Republic of China
| | - Jin-Jiang Li
- Department of Neurosurgery, General Hospital of Shenyang Military Command Area, Shenyang, Liaoning, 110016, People's Republic of China
| | - Jing-Chen Li
- Department of Neurosurgery, General Hospital of Shenyang Military Command Area, Shenyang, Liaoning, 110016, People's Republic of China
| | - Guang-Zhi Hao
- Department of Neurosurgery, General Hospital of Shenyang Military Command Area, Shenyang, Liaoning, 110016, People's Republic of China
| | - Chao Wang
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
| | - Ju-Lei Wang
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
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26
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Dębski KJ, Pitkanen A, Puhakka N, Bot AM, Khurana I, Harikrishnan KN, Ziemann M, Kaspi A, El-Osta A, Lukasiuk K, Kobow K. Etiology matters - Genomic DNA Methylation Patterns in Three Rat Models of Acquired Epilepsy. Sci Rep 2016; 6:25668. [PMID: 27157830 PMCID: PMC4860710 DOI: 10.1038/srep25668] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/20/2016] [Indexed: 12/21/2022] Open
Abstract
This study tested the hypothesis that acquired epileptogenesis is accompanied by DNA methylation changes independent of etiology. We investigated DNA methylation and gene expression in the hippocampal CA3/dentate gyrus fields at 3 months following epileptogenic injury in three experimental models of epilepsy: focal amygdala stimulation, systemic pilocarpine injection, or lateral fluid-percussion induced traumatic brain injury (TBI) in rats. In the models studies, DNA methylation and gene expression profiles distinguished controls from injured animals. We observed consistent increased methylation in gene bodies and hypomethylation at non-genic regions. We did not find a common methylation signature in all three different models and few regions common to any two models. Our data provide evidence that genome-wide alteration of DNA methylation signatures is a general pathomechanism associated with epileptogenesis and epilepsy in experimental animal models, but the broad pathophysiological differences between models (i.e. pilocarpine, amygdala stimulation, and post-TBI) are reflected in distinct etiology-dependent DNA methylation patterns.
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Affiliation(s)
- Konrad J. Dębski
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Asla Pitkanen
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Noora Puhakka
- Epilepsy Research Laboratory, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Anna M. Bot
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Ishant Khurana
- Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | - KN Harikrishnan
- Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | - Mark Ziemann
- Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | - Antony Kaspi
- Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | - Assam El-Osta
- Epigenetics in Human Health and Disease, Baker IDI Heart and Diabetes Institute, The Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | - Katarzyna Lukasiuk
- Laboratory of Epileptogenesis, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Katja Kobow
- Department of Neuropathology, University Hospital Erlangen, Schwabachanlage 6, 91054 Erlangen, Germany
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27
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DNA Methylation Profiling Reveals Correlation of Differential Methylation Patterns with Gene Expression in Human Epilepsy. J Mol Neurosci 2016; 59:68-77. [DOI: 10.1007/s12031-016-0735-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/04/2016] [Indexed: 12/11/2022]
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28
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Abstract
Epigenetic processes in the brain involve the transfer of information arising from short-lived cellular signals and changes in neuronal activity into lasting effects on gene expression. Key molecular mediators of epigenetics include methylation of DNA, histone modifications, and noncoding RNAs. Emerging findings in animal models and human brain tissue reveal that epilepsy and epileptogenesis are associated with changes to each of these contributors to the epigenome. Understanding and influencing the molecular mechanisms controlling epigenetic change could open new avenues for treatment. DNA methylation, particularly hypermethylation, has been found to increase within gene body regions and interference with DNA methylation in epilepsy can change gene expression profiles and influence epileptogenesis. Posttranscriptional modification of histones, including transient as well as sustained changes to phosphorylation and acetylation, have been reported, which appear to influence gene expression. Finally, roles have emerged for noncoding RNAs in brain excitability and seizure thresholds, including microRNA and long noncoding RNA. Together, research supports strong effects of epigenetics influencing gene expression in epilepsy, suggesting future therapeutic approaches to manipulate epigenetic processes to treat or prevent epilepsy.
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Affiliation(s)
- David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Katja Kobow
- Department of Neuropathology, University Hospital Erlangen, 91054 Erlangen, Germany
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Sapio MR, Vessaz M, Thomas P, Genton P, Fricker LD, Salzmann A. Novel carboxypeptidase A6 (CPA6) mutations identified in patients with juvenile myoclonic and generalized epilepsy. PLoS One 2015; 10:e0123180. [PMID: 25875328 PMCID: PMC4395397 DOI: 10.1371/journal.pone.0123180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 02/17/2015] [Indexed: 01/12/2023] Open
Abstract
Carboxypeptidase A6 (CPA6) is a peptidase that removes C-terminal hydrophobic amino acids from peptides and proteins. The CPA6 gene is expressed in the brains of humans and animals, with high levels of expression during development. It is translated with a prodomain (as proCPA6), which is removed before secretion. The active form of CPA6 binds tightly to the extracellular matrix (ECM) where it is thought to function in the processing of peptides and proteins. Mutations in the CPA6 gene have been identified in patients with temporal lobe epilepsy and febrile seizures. In the present study, we screened for CPA6 mutations in patients with juvenile myoclonic epilepsy and identified two novel missense mutations: Arg36His and Asn271Ser. Patients harboring these mutations also presented with generalized epilepsy. Neither of the novel mutations was found in a control population. Asn271 is highly conserved in CPA6 and other related metallocarboxypeptidases. Arg36 is present in the prodomain and is not highly conserved. To assess structural consequences of the amino acid substitutions, both mutants were modeled within the predicted structure of the enzyme. To examine the effects of these mutations on enzyme expression and activity, we expressed the mutated enzymes in human embryonic kidney 293T cells. These analyses revealed that Asn271Ser abolished enzymatic activity, while Arg36His led to a ~50% reduction in CPA6 levels in the ECM. Pulse-chase using radio-labeled amino acids was performed to follow secretion. Newly-synthesized CPA6 appeared in the ECM with peak levels between 2-8 hours. There was no major difference in time course between wild-type and mutant forms, although the amount of radiolabeled CPA6 in the ECM was lower for the mutants. Our experiments demonstrate that these mutations in CPA6 are deleterious and provide further evidence for the involvement of CPA6 mutations in the predisposition for several types of epilepsy.
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Affiliation(s)
- Matthew R. Sapio
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Monique Vessaz
- Department of Genetic Medicine and Laboratory, University Hospitals of Geneva, Geneva, Switzerland
| | - Pierre Thomas
- Department of Neurology, University Hospital, Nice, France
| | - Pierre Genton
- Centre Saint Paul, Hôpital Henri Gastaut, Marseille, France
| | - Lloyd D. Fricker
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States of America
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
- * E-mail: (LDF); (AS)
| | - Annick Salzmann
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
- * E-mail: (LDF); (AS)
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Abstract
In humans, genomic DNA is organized in 23 chromosome pairs coding for roughly 25,000 genes. Not all of them are active at all times. During development, a broad range of different cell types needs to be generated in a highly ordered and reproducible manner, requiring selective gene expression programs. Epigenetics can be regarded as the information management system that is able to index or bookmark distinct regions in our genome to regulate the readout of DNA. It further comprises the molecular memory of any given cell, allowing it to store information of previously experienced external (e.g., environmental) or internal (e.g., developmental) stimuli, to learn from this experience and to respond. The underlying epigenetic mechanisms can be synergistic, antagonistic, or mutually exclusive and their large variety combined with the variability and interdependence is thought to provide the molecular basis for any phenotypic variation in physiological and pathological conditions. Thus, widespread reconfiguration of the epigenome is not only a key feature of neurodevelopment, brain maturation, and adult brain function but also disease.
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Affiliation(s)
- Katja Kobow
- Department of Neuropathology, University Hospital Erlangen, Schwabachanlage, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Schwabachanlage, Erlangen, Germany.
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