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Bahabry R, Hauser RM, Sánchez RG, Jago SS, Ianov L, Stuckey RJ, Parrish RR, Hoef LV, Lubin FD. Alterations in DNA 5-hydroxymethylation Patterns in the Hippocampus of an Experimental Model of Refractory Epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560698. [PMID: 37873276 PMCID: PMC10592907 DOI: 10.1101/2023.10.03.560698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Temporal lobe epilepsy (TLE) is a type of focal epilepsy characterized by spontaneous recurrent seizures originating from the hippocampus. The epigenetic reprogramming hypothesis of epileptogenesis suggests that the development of TLE is associated with alterations in gene transcription changes resulting in a hyperexcitable network in TLE. DNA 5-methylcytosine (5-mC) is an epigenetic mechanism that has been associated with chronic epilepsy. However, the contribution of 5-hydroxymethylcytosine (5-hmC), a product of 5-mC demethylation by the Ten-Eleven Translocation (TET) family proteins in chronic TLE is poorly understood. 5-hmC is abundant in the brain and acts as a stable epigenetic mark altering gene expression through several mechanisms. Here, we found that the levels of bulk DNA 5-hmC but not 5-mC were significantly reduced in the hippocampus of human TLE patients and in the kainic acid (KA) TLE rat model. Using 5-hmC hMeDIP-sequencing, we characterized 5-hmC distribution across the genome and found bidirectional regulation of 5-hmC at intergenic regions within gene bodies. We found that hypohydroxymethylated 5-hmC intergenic regions were associated with several epilepsy-related genes, including Gal , SV2, and Kcnj11 and hyperdroxymethylation 5-hmC intergenic regions were associated with Gad65 , TLR4 , and Bdnf gene expression. Mechanistically, Tet1 knockdown in the hippocampus was sufficient to decrease 5-hmC levels and increase seizure susceptibility following KA administration. In contrast, Tet1 overexpression in the hippocampus resulted in increased 5-hmC levels associated with improved seizure resiliency in response to KA. These findings suggest an important role for 5-hmC as an epigenetic regulator of epilepsy that can be manipulated to influence seizure outcomes.
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Song LJ, Zhang H, Qu XP, Jin JG, Wang C, Jiang X, Gao L, Li G, Wang DL, Shen LL, Liu B. Increased expression of Rho-associated protein kinase 2 confers astroglial Stat3 pathway activation during epileptogenesis. Neurosci Res 2021; 177:25-37. [PMID: 34740726 DOI: 10.1016/j.neures.2021.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/28/2021] [Accepted: 10/31/2021] [Indexed: 10/19/2022]
Abstract
Patients with TLE are prone to tolerance to antiepileptic drugs. Based on the perspective of molecular targets for drug resistance, it is necessary to explore effective drug resistant genes and signaling pathways for the treatment of TLE. We performed gene expression profiles in hippocampus of patients with drug-resistant TLE and identified ROCK2 as one of the 20 most significantly increased genes in hippocampus. In vitro and in vivo experiments were performed to identify the potential role of ROCK2 in epileptogenesis. In addition, the activity of Stat3 pathway was tested in rat hippocampal tissues and primary cultured astrocytes. The expression levels of ROCK2 in the hippocampus of TLE patients were significantly increased compared with the control group, which was due to the hypomethylation of ROCK2 promoter. Fasudil, a specific Rho-kinase inhibitor, alleviated epileptic seizures in the pilocarpine rat model of TLE. Furthermore, ROCK2 activated the Stat3 pathway in pilocarpine-treated epilepsy rats, and the spearman correlation method confirmed that ROCK2 is associated with Stat3 activation in TLE patients. In addition, ROCK2 was predominantly expressed in astrocytes during epileptogenesis, and induced epileptogenesis by activating astrocyte cell cycle progression via Stat3 pathway. The overexpressed ROCK2 plays an important role in the pathogenesis of drug-resistant epilepsy. ROCK2 accelerates astrocytes cell cycle progression via the activation of Stat3 pathway likely provides the key to explaining the process of epileptogenesis.
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Affiliation(s)
- Li-Jia Song
- Department of Pediatrics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Hua Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Xiao-Peng Qu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Jun-Gong Jin
- Department of Neurosurgery, Xi'an International Medical Center, Xi'an, China
| | - Chao Wang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Xue Jiang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Li Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Gang Li
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Da-Li Wang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Liang-Liang Shen
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China.
| | - Bei Liu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
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Suchkova IO, Borisova EV, Patkin EL. Length Polymorphism and Methylation Status of UPS29 Minisatellite of the ACAP3 Gene as Molecular Biomarker of Epilepsy. Sex Differences in Seizure Types and Symptoms. Int J Mol Sci 2020; 21:E9206. [PMID: 33276684 PMCID: PMC7730309 DOI: 10.3390/ijms21239206] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 01/10/2023] Open
Abstract
Epilepsy is a neurological disease with different clinical forms and inter-individuals heterogeneity, which may be associated with genetic and/or epigenetic polymorphisms of tandem-repeated noncoding DNA. These polymorphisms may serve as predictive biomarkers of various forms of epilepsy. ACAP3 is the protein regulating morphogenesis of neurons and neuronal migration and is an integral component of important signaling pathways. This study aimed to carry out an association analysis of the length polymorphism and DNA methylation of the UPS29 minisatellite of the ACAP3 gene in patients with epilepsy. We revealed an association of short UPS29 alleles with increased risk of development of symptomatic and cryptogenic epilepsy in women, and also with cerebrovascular pathologies, structural changes in the brain, neurological status, and the clinical pattern of seizures in both women and men. The increase of frequency of hypomethylated UPS29 alleles in men with symptomatic epilepsy, and in women with both symptomatic and cryptogenic epilepsy was observed. For patients with hypomethylated UPS29 alleles, we also observed structural changes in the brain, neurological status, and the clinical pattern of seizures. These associations had sex-specific nature similar to a genetic association. In contrast with length polymorphism epigenetic changes affected predominantly the long UPS29 allele. We suppose that genetic and epigenetic alterations UPS29 can modify ACAP3 expression and thereby affect the development and clinical course of epilepsy.
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Affiliation(s)
- Irina O. Suchkova
- Laboratory of Molecular Cytogenetics of Mammalian Development, Department of Molecular Genetics, Institute of Experimental Medicine of the Russian Academy of Sciences, St. Petersburg 197376, Russia;
| | - Elena V. Borisova
- Department of Neurology, Clinic of Institute of Experimental Medicine, St. Petersburg 197376, Russia;
| | - Eugene L. Patkin
- Laboratory of Molecular Cytogenetics of Mammalian Development, Department of Molecular Genetics, Institute of Experimental Medicine of the Russian Academy of Sciences, St. Petersburg 197376, Russia;
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Caramaschi D, Hatcher C, Mulder RH, Felix JF, Cecil CAM, Relton CL, Walton E. Epigenome-wide association study of seizures in childhood and adolescence. Clin Epigenetics 2020; 12:8. [PMID: 31915053 PMCID: PMC6950851 DOI: 10.1186/s13148-019-0793-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/02/2019] [Indexed: 12/31/2022] Open
Abstract
The occurrence of seizures in childhood is often associated with neurodevelopmental impairments and school underachievement. Common genetic variants associated with epilepsy have been identified and epigenetic mechanisms have also been suggested to play a role. In this study, we analyzed the association of genome-wide blood DNA methylation with the occurrence of seizures in ~ 800 children from the Avon Longitudinal Study of Parents and Children, UK, at birth (cord blood), during childhood, and adolescence (peripheral blood). We also analyzed the association between the lifetime occurrence of any seizures before age 13 with blood DNA methylation levels. We sought replication of the findings in the Generation R Study and explored causality using Mendelian randomization, i.e., using genetic variants as proxies. The results showed five CpG sites which were associated cross-sectionally with seizures either in childhood or adolescence (1-5% absolute methylation difference at pFDR < 0.05), although the evidence of replication in an independent study was weak. One of these sites was located in the BDNF gene, which is highly expressed in the brain, and showed high correspondence with brain methylation levels. The Mendelian randomization analyses suggested that seizures might be causal for changes in methylation rather than vice-versa. In conclusion, we show a suggestive link between seizures and blood DNA methylation while at the same time exploring the limitations of conducting such study.
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Affiliation(s)
- Doretta Caramaschi
- Bristol Medical School, Population Health Sciences, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK. .,Medical Research Council Integrative Epidemiology Unit, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK.
| | - Charlie Hatcher
- Bristol Medical School, Population Health Sciences, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK.,Medical Research Council Integrative Epidemiology Unit, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
| | - Rosa H Mulder
- Institute of Education and Child Studies, Leiden University, Pieter de la Court building, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands.,Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands.,Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands
| | - Janine F Felix
- Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands.,Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands.,Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands
| | - Charlotte A M Cecil
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands.,Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, The Netherlands
| | - Caroline L Relton
- Bristol Medical School, Population Health Sciences, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK.,Medical Research Council Integrative Epidemiology Unit, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
| | - Esther Walton
- Bristol Medical School, Population Health Sciences, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK.,Medical Research Council Integrative Epidemiology Unit, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK.,Department of Psychology, University of Bath, Bath, BA2 7AY, UK
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