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Chen S, Huang M, Xu D, Li M. Epigenetic regulation in epilepsy: A novel mechanism and therapeutic strategy for epilepsy. Neurochem Int 2024; 173:105657. [PMID: 38145842 DOI: 10.1016/j.neuint.2023.105657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 12/02/2023] [Accepted: 12/14/2023] [Indexed: 12/27/2023]
Abstract
Epilepsy is a common neurological disorder characterized by recurrent seizures with excessive and abnormal neuronal discharges. Epileptogenesis is usually involved in neuropathological processes such as ion channel dysfunction, neuronal injury, inflammatory response, synaptic plasticity, gliocyte proliferation and mossy fiber sprouting, currently the pathogenesis of epilepsy is not yet completely understood. A growing body of studies have shown that epigenetic regulation, such as histone modifications, DNA methylation, noncoding RNAs (ncRNAs), N6-methyladenosine (m6A) and restrictive element-1 silencing transcription factor/neuron-restrictive silencing factor (REST/NRSF) are also involved in epilepsy. Through epigenetic studies, we found that the synaptic dysfunction, nerve damage, cognitive dysfunction and brain development abnormalities are affected by epigenetic regulation of epilepsy-related genes in patients with epilepsy. However, the functional roles of epigenetics in pathogenesis and treatment of epilepsy are still to be explored. Therefore, profiling the array of genes that are epigenetically dysregulated in epileptogenesis is likely to advance our understanding of the mechanisms underlying the pathophysiology of epilepsy and may for the amelioration of these serious human conditions provide novel insight into therapeutic strategies and diagnostic biomarkers for epilepsy to improve serious human condition.
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Affiliation(s)
- Shuang Chen
- Department of Neurology, Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Hubei University of Chinese Medicine, Wuhan, 430000, China
| | - Ming Huang
- Department of Neurology, Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Hubei University of Chinese Medicine, Wuhan, 430000, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China
| | - Man Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China.
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Younesian S, Yousefi AM, Momeny M, Ghaffari SH, Bashash D. The DNA Methylation in Neurological Diseases. Cells 2022; 11:3439. [PMID: 36359835 PMCID: PMC9657829 DOI: 10.3390/cells11213439] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 10/25/2022] [Indexed: 07/30/2023] Open
Abstract
DNA methylation is critical for the normal development and functioning of the human brain, such as the proliferation and differentiation of neural stem cells, synaptic plasticity, neuronal reparation, learning, and memory. Despite the physical stability of DNA and methylated DNA compared to other epigenetic modifications, some DNA methylation-based biomarkers have translated into clinical practice. Increasing reports indicate a strong association between DNA methylation profiles and various clinical outcomes in neurological diseases, making DNA methylation profiles valuable as novel clinical markers. In this review, we aim to discuss the latest evidence concerning DNA methylation alterations in the development of neurodegenerative, neurodevelopmental, and neuropsychiatric diseases. We also highlighted the relationship of DNA methylation alterations with the disease progression and outcome in many neurological diseases such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and autism.
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Affiliation(s)
- Samareh Younesian
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran 1971653313, Iran
| | - Amir-Mohammad Yousefi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran 1971653313, Iran
| | - Majid Momeny
- The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Seyed H. Ghaffari
- Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran 1411713135, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran 1971653313, Iran
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3
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Kong X, Liang H, Zhou K, Wang H, Li D, Zhang S, Sun N, Gong M, Zhou Y, Zhang Q. Deciphering the Heterogeneity of the Internal Environment of Hippocampal Neurons during Maturation by Raman Spectroscopy. ACS OMEGA 2022; 7:30571-30581. [PMID: 36061692 PMCID: PMC9435027 DOI: 10.1021/acsomega.2c04188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Hippocampal neurons are sensitive to changes in the internal environment and play a significant role in controlling learning, memory, and emotions. A remarkable characteristic of the aging brain is its ability to shift from a state of normal inflammation to excessive inflammation. Various cognitive abilities of the elderly may suffer from serious harm due to the change in the neural environment. Hippocampal neurons may have various subsets involved in controlling their internal environment at different stages of development. Developmental differences may eventually result from complex changes in the dynamic neuronal system brought on by metabolic changes. In this study, we used an in vitro hippocampal neuron model cultured in C57BL/6J mice in conjugation with Raman spectroscopy to examine the relative alterations in potential biomarkers, such as levels of metabolites in the internal environment of hippocampal neurons at various developmental stages. The various differentially expressed genes (DEGs) of hippocampal neurons at various developmental stages were simultaneously screened using bioinformatics, and the biological functions as well as the various regulatory pathways of DEGs were preliminarily analyzed, providing an essential reference for investigating novel therapeutic approaches for diseases that cause cognitive impairment, such as Alzheimer's disease. A stable hippocampal neuron model was established using the GIBCO C57BL/6J hippocampal neuron cell line as a donor and in vitro hippocampal neuron culture technology. The Raman peak intensities of culture supernatants from the experimental groups incubated for 0, 7, and 14 days in vitro(DIV) were examined. The GEO database was used to screen for different DEGs associated with various developmental stages. The data was then analyzed using a statistical method called orthogonal partial least squares discriminant analysis (OPLS-DA). The levels of ketogenic and glycogenic amino acids (such as tryptophan, phenylalanine, and tyrosine), lipid intake rate, glucose utilization rate, and nucleic acid expression in the internal environment of hippocampal neurons were significantly different in the 14 DIV group compared to the 0 DIV and 7 DIV groups (P < 0.01). The top 10 DEGs with neuronal maturation were screened, and the results were compared to the OPLS-DA model's analysis of the differential peaks. It was found that different genes involved in maturation can directly relate to changes in the body's levels of ketogenic and glycogenic amino acids (P < 0.01). The altered expression of the maturation-related genes epidermal growth factor receptor, protein tyrosine kinase 2-beta, discs large MAGUK scaffold protein 2, and Ras protein-specific guanine nucleotide releasing factor 1 may be connected to the altered uptake of ketogenic and glycogenic amino acids and nucleic acids in the internal environment of neurons at different developmental stages. The levels of ketogenic, glycogenic amino acids, and lipid intake increased while glucose utilization decreased, which may be related to mature neurons' metabolism and energy use. The decline in nucleic acid consumption could be connected to synaptic failure. The Raman spectroscopy fingerprint results of relevant biomarkers in conjugation with multivariable analysis and biological action targets suggested by differential genes interpret the heterogeneity of the internal environment of mature hippocampal neurons in the process of maturation, open a new idea for exploring the dynamic mechanism of the exchange energy metabolism of information molecules in the internal environment of hippocampal neurons, and provide a new method for studying this process.
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Affiliation(s)
- Xiaodong Kong
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
| | - Haoyue Liang
- State
Key Laboratory of Experimental Hematology, National Clinical Research
Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital,
Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Kexuan Zhou
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
| | - Haoyu Wang
- State
Key Laboratory of Experimental Hematology, National Clinical Research
Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital,
Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Dai Li
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
| | - Shishuang Zhang
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
| | - Ning Sun
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
| | - Min Gong
- Department
of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Yuan Zhou
- State
Key Laboratory of Experimental Hematology, National Clinical Research
Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital,
Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Qiang Zhang
- Department
of Geriatrics, Tianjin Medical University
General Hospital, Tianjin Geriatrics Institute, Tianjin 300052, China
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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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5
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Inhibitors of DNA Methylation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:471-513. [DOI: 10.1007/978-3-031-11454-0_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ichise E, Chiyonobu T, Ishikawa M, Tanaka Y, Shibata M, Tozawa T, Taura Y, Yamashita S, Yoshida M, Morimoto M, Higurashi N, Yamamoto T, Okano H, Hirose S. Impaired neuronal activity and differential gene expression in STXBP1 encephalopathy patient iPSC-derived GABAergic neurons. Hum Mol Genet 2021; 30:1337-1348. [PMID: 33961044 DOI: 10.1093/hmg/ddab113] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/10/2021] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
Syntaxin-binding protein 1 (STXBP1; also called MUNC18-1), encoded by STXBP1, is an essential component of the molecular machinery that controls synaptic vesicle docking and fusion. De novo pathogenic variants of STXBP1 cause a complex set of neurological disturbances, namely STXBP1 encephalopathy (STXBP1-E) that includes epilepsy, neurodevelopmental disorders and neurodegeneration. Several animal studies have suggested the contribution of GABAergic dysfunction in STXBP1-E pathogenesis. However, the pathophysiological changes in GABAergic neurons of these patients are still poorly understood. Here, we exclusively generated GABAergic neurons from STXBP1-E patient-derived induced pluripotent stem cells (iPSCs) by transient expression of the transcription factors ASCL1 and DLX2. We also generated CRISPR/Cas9-edited isogenic iPSC-derived GABAergic (iPSC GABA) neurons as controls. We demonstrated that the reduction in STXBP1 protein levels in patient-derived iPSC GABA neurons was slight (approximately 20%) compared to the control neurons, despite a 50% reduction in STXBP1 mRNA levels. Using a microelectrode array-based assay, we found that patient-derived iPSC GABA neurons exhibited dysfunctional maturation with reduced numbers of spontaneous spikes and bursts. These findings reinforce the idea that GABAergic dysfunction is a crucial contributor to STXBP1-E pathogenesis. Moreover, gene expression analysis revealed specific dysregulation of genes previously implicated in epilepsy, neurodevelopment and neurodegeneration in patient-derived iPSC GABA neurons, namely KCNH1, KCNH5, CNN3, RASGRF1, SEMA3A, SIAH3 and INPP5F. Thus, our study provides new insights for understanding the biological processes underlying the widespread neuropathological features of STXBP1-E.
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Affiliation(s)
- Eisuke Ichise
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Tomohiro Chiyonobu
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Mitsuru Ishikawa
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Yasuyoshi Tanaka
- Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka 814-0180, Japan
| | - Mami Shibata
- Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka 814-0180, Japan
| | - Takenori Tozawa
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Yoshihiro Taura
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Satoshi Yamashita
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Michiko Yoshida
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Masafumi Morimoto
- Department of Medical Science, School of Nursing, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Norimichi Higurashi
- Department of Pediatrics, Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Toshiyuki Yamamoto
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Shinichi Hirose
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
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Anwar H, Khan QU, Nadeem N, Pervaiz I, Ali M, Cheema FF. Epileptic seizures. Discoveries (Craiova) 2020; 8:e110. [PMID: 32577498 PMCID: PMC7305811 DOI: 10.15190/d.2020.7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/02/2020] [Accepted: 06/02/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a condition marked by abnormal neuronal discharges or hyperexcitability of neurons with synchronicity and is recognized as a major public health concern. The pathology is categorized into three subgroups: acquired, idiopathic, and epilepsy of genetic or developmental origin. There are approximately 1000 associated genes and the role of γ-aminobutyric acid (GABA) mediated inhibition, as well as glutamate mediated excitation, forms the basis of pathology. Epilepsy is further classified as being of focal, general or unknown onset. Genetic predisposition, comorbidities and novel biomarkers are useful for prediction. Prevalent postictal symptoms are postictal headache and migraine, postictal psychosis and delirium, postictal Todd's paresis and postictal automatisms. Diagnostic methods include electroencephalography (EEG), computed tomography scan, magnetic resonance imaging (MRI), positron emission tomography, single photon emission computed tomography and genetic testing; EEG and MRI are the two main techniques. Clinical history and witness testimonies combined with a knowledge of seizure semiology helps in distinguishing between seizures. Clinical information and patient history do not always lead to a clear diagnosis, in which case EEG and 24-hour EEG monitoring with video recording (video-EEG/vEEG) help in seizure differentiation. Treatment includes first aid, therapeutics such as anti-epileptic drugs, surgery, ketogenic diet and gene therapy. In this review, we are focusing on summarizing published literature on epilepsy and epileptic seizures, and concisely apprise the reader of the latest cutting-edge advances and knowledge on epileptic seizures.
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Affiliation(s)
- Haleema Anwar
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | | | - Natasha Nadeem
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | - Iqra Pervaiz
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | - Muhammad Ali
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
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Boison D, Rho JM. Epigenetics and epilepsy prevention: The therapeutic potential of adenosine and metabolic therapies. Neuropharmacology 2020; 167:107741. [PMID: 31419398 PMCID: PMC7220211 DOI: 10.1016/j.neuropharm.2019.107741] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/08/2019] [Accepted: 08/13/2019] [Indexed: 12/20/2022]
Abstract
Prevention of epilepsy and its progression remains the most urgent need for epilepsy research and therapy development. Novel conceptual advances are required to meaningfully address this fundamental challenge. Maladaptive epigenetic changes, which include methylation of DNA and acetylation of histones - among other mechanisms, are now well recognized to play a functional role in the development of epilepsy and its progression. The methylation hypothesis of epileptogenesis suggests that changes in DNA methylation are implicated in the progression of the disease. In this context, global DNA hypermethylation is particularly associated with chronic epilepsy. Likewise, acetylation changes of histones have been linked to epilepsy development. Clinical as well as experimental evidence demonstrate that epilepsy and its progression can be prevented by metabolic and biochemical manipulations that target previously unrecognized epigenetic functions contributing to epilepsy development and maintenance of the epileptic state. This review will discuss epigenetic mechanisms implicated in epilepsy development as well as metabolic and biochemical interactions thought to drive epileptogenesis. Therefore, metabolic and biochemical mechanisms are identified as novel targets for epilepsy prevention. We will specifically discuss adenosine biochemistry as a novel therapeutic strategy to reconstruct the DNA methylome as antiepileptogenic strategy as well as metabolic mediators, such as beta-hydroxybutyrate, which affect histone acetylation. Finally, metabolic dietary interventions (such as the ketogenic diet) which have the unique potential to prevent epileptogenesis through recently identified epigenetic mechanisms will be reviewed. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Detlev Boison
- Dept. of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA.
| | - Jong M Rho
- Depts. of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, CA, 92117, USA
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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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Berger TC, Vigeland MD, Hjorthaug HS, Etholm L, Nome CG, Taubøll E, Heuser K, Selmer KK. Neuronal and glial DNA methylation and gene expression changes in early epileptogenesis. PLoS One 2019; 14:e0226575. [PMID: 31887157 PMCID: PMC6936816 DOI: 10.1371/journal.pone.0226575] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/28/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND AIMS Mesial Temporal Lobe Epilepsy is characterized by progressive changes of both neurons and glia, also referred to as epileptogenesis. No curative treatment options, apart from surgery, are available. DNA methylation (DNAm) is a potential upstream mechanism in epileptogenesis and may serve as a novel therapeutic target. To our knowledge, this is the first study to investigate epilepsy-related DNAm, gene expression (GE) and their relationship, in neurons and glia. METHODS We used the intracortical kainic acid injection model to elicit status epilepticus. At 24 hours post injection, hippocampi from eight kainic acid- (KA) and eight saline-injected (SH) mice were extracted and shock frozen. Separation into neurons and glial nuclei was performed by flow cytometry. Changes in DNAm and gene expression were measured with reduced representation bisulfite sequencing (RRBS) and mRNA-sequencing (mRNAseq). Statistical analyses were performed in R with the edgeR package. RESULTS We observed fulminant DNAm- and GE changes in both neurons and glia at 24 hours after initiation of status epilepticus. The vast majority of these changes were specific for either neurons or glia. At several epilepsy-related genes, like HDAC11, SPP1, GAL, DRD1 and SV2C, significant differential methylation and differential gene expression coincided. CONCLUSION We found neuron- and glia-specific changes in DNAm and gene expression in early epileptogenesis. We detected single genetic loci in several epilepsy-related genes, where DNAm and GE changes coincide, worth further investigation. Further, our results may serve as an information source for neuronal and glial alterations in both DNAm and GE in early epileptogenesis.
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Affiliation(s)
- Toni C. Berger
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- University of Oslo, Oslo, Norway
- * E-mail:
| | - Magnus D. Vigeland
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Hanne S. Hjorthaug
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Lars Etholm
- National Center for Epilepsy, Oslo University Hospital, Sandvika, Norway
- Department of Neurology, Section for Neurophysiology, Oslo University Hospital, Oslo, Norway
| | | | - Erik Taubøll
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- University of Oslo, Oslo, Norway
| | - Kjell Heuser
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- University of Oslo, Oslo, Norway
| | - Kaja K. Selmer
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
- National Center for Epilepsy, Oslo University Hospital, Sandvika, Norway
- Division of Clinical Neuroscience, Department of Research and Development, Oslo University Hospital, Oslo, Norway
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RASgrf1, a Potential Methylatic Mediator of Anti-epileptogenesis? Neurochem Res 2018; 43:2000-2007. [PMID: 30242550 DOI: 10.1007/s11064-018-2621-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 08/02/2018] [Accepted: 08/21/2018] [Indexed: 01/02/2023]
Abstract
Epileptogenesis, induced by status epilepticus (SE), is a chronic process, and intervention in this progress may prevent chronic epilepsy. It has been proposed that DNA methylation might be related with epileptogenesis. RASgrf1 has a differentially methylated region at the promoter which can silence gene expression. We have previously observed the down-regulation of RASgrf1 in epilepsy patients and proved that hypermethylation of RASgrf1 reaches maximal level at the latent period in mice after kainate-induced SE (KA mice), with corresponding alteration of RASgrf1 expression. In the present study, N-phthalyl-L-tryptophan (RG108), a DNA methyltransferase inhibitor, was applied in KA mice at latent phase and the behavior, electroencephalogram and pathological changes were observed in chronic phase. Methylation and expression of RASgrf1 were determined by polymerase chain reaction (PCR), western blotting, and bisulfite sequencing PCR. The results showed that the incidence of spontaneous recurrent seizures (SRS) was significantly lower in the RG108 group than the normal saline (NS) group. Subgroup analysis showed significant hypermethylation and lower expression of RASgrf1 in the RG108-SRS subgroup and the NS-SRS subgroup but not in the RG108-NSRS (no SRS) subgroup and the NS-NSRS subgroup compared with the control group. No significant difference was found between the RG108-SRS and NS-SRS subgroups. Meanwhile, hippocampal neuronal loss was observed in RG108-SRS and NS-SRS subgroups. We thus demonstrated that RG108 could modify the progression of epileptogenesis after KA induced SE and prevent chronic epilepsy. Meanwhile, hypermethylation of RASgrf1 after KA induced SE could be reversed with corresponding changes of RASgrf1 expression. Additionally, we speculated that RASgrf1 might be a potential epigenetic mediator in epileptogenesis and chronic epilepsy.
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