1
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Bahabry R, Hauser RM, Sánchez RG, Jago SS, Ianov L, Stuckey RJ, Parrish RR, Ver Hoef L, Lubin FD. Alterations in DNA 5-hydroxymethylation patterns in the hippocampus of an experimental model of chronic epilepsy. Neurobiol Dis 2024:106638. [PMID: 39142613 DOI: 10.1016/j.nbd.2024.106638] [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: 10/17/2023] [Revised: 07/27/2024] [Accepted: 08/11/2024] [Indexed: 08/16/2024] Open
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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Affiliation(s)
- Rudhab Bahabry
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Rebecca M Hauser
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Richard G Sánchez
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Silvienne Sint Jago
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Lara Ianov
- Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Remy J Stuckey
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - R Ryley Parrish
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals, Burnaby, BC, Canada
| | - Lawrence Ver Hoef
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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2
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Khoodoruth MAS, Chut-kai Khoodoruth WN, Al Alwani R. Exploring the epigenetic landscape: The role of 5-hydroxymethylcytosine in neurodevelopmental disorders. CAMBRIDGE PRISMS. PRECISION MEDICINE 2024; 2:e5. [PMID: 38699519 PMCID: PMC11062787 DOI: 10.1017/pcm.2024.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/18/2024] [Accepted: 03/16/2024] [Indexed: 05/05/2024]
Abstract
Recent advances in genetic and epigenetic research have underscored the significance of 5-hydroxymethylcytosine (5hmC) in neurodevelopmental disorders (NDDs), such as autism spectrum disorder (ASD) and intellectual disability (ID), revealing its potential as both a biomarker for early detection and a target for novel therapeutic strategies. This review article provides a comprehensive analysis of the role of 5hmC in NDDs by examining both animal models and human studies. By examining mouse models, studies have demonstrated that prenatal environmental challenges, such as maternal infection and food allergies, lead to significant epigenetic alterations in 5hmC levels, which were associated with NDDs in offspring, impacting social behavior, cognitive abilities and increasing ASD-like symptoms. In human studies, researchers have linked alterations in 5hmC levels NDDs through studies in individuals with ASD, fragile X syndrome, TET3 deficiency and ID, specifically identifying significant epigenetic modifications in genes such as GAD1, RELN, FMR1 and EN-2, suggesting that dysregulation of 5hmC played a critical role in the pathogenesis of these disorders and highlighted the potential for targeted therapeutic interventions. Moreover, we explore the implications of these findings for the development of epigenetic therapies aimed at modulating 5hmC levels. The review concludes with a discussion on future directions for research in this field, such as machine learning, emphasizing the need for further studies to elucidate the complex mechanisms underlying NDDs and to translate these findings into clinical practice. This paper not only advances our understanding of the epigenetic landscape of NDDs but also opens up new avenues for diagnosis and treatment, offering hope for individuals affected by these conditions.
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Affiliation(s)
- Mohamed Adil Shah Khoodoruth
- Department of Child and Adolescent Psychiatry, Hamad Medical Corporation, Doha, Qatar
- Division of Genomics and Precision Medicine, College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | | | - Rafaa Al Alwani
- College of Science and Engineering, Hamad Bin Khalifa University, Doha, Qatar
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3
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Ma X, Thela SR, Zhao F, Yao B, Wen Z, Jin P, Zhao J, Chen L. Deep5hmC: Predicting genome-wide 5-Hydroxymethylcytosine landscape via a multimodal deep learning model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.04.583444. [PMID: 38496575 PMCID: PMC10942288 DOI: 10.1101/2024.03.04.583444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
5-hydroxymethylcytosine (5hmC), a critical epigenetic mark with a significant role in regulating tissue-specific gene expression, is essential for understanding the dynamic functions of the human genome. Using tissue-specific 5hmC sequencing data, we introduce Deep5hmC, a multimodal deep learning framework that integrates both the DNA sequence and the histone modification information to predict genome-wide 5hmC modification. The multimodal design of Deep5hmC demonstrates remarkable improvement in predicting both qualitative and quantitative 5hmC modification compared to unimodal versions of Deep5hmC and state-of-the-art machine learning methods. This improvement is demonstrated through benchmarking on a comprehensive set of 5hmC sequencing data collected at four time points during forebrain organoid development and across 17 human tissues. Notably, Deep5hmC showcases its practical utility by accurately predicting gene expression and identifying differentially hydroxymethylated regions in a case-control study of Alzheimer's disease.
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Affiliation(s)
- Xin Ma
- Department of Biostatistics, University of Florida, Gainesville, FL, 32603, USA
| | - Sai Ritesh Thela
- Department of Biostatistics, University of Florida, Gainesville, FL, 32603, USA
| | - Fengdi Zhao
- Department of Biostatistics, University of Florida, Gainesville, FL, 32603, USA
| | - Bing Yao
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Zhexing Wen
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Jinying Zhao
- Department of Epidemiology, University of Florida, Gainesville, FL, 32603, USA
| | - Li Chen
- Department of Biostatistics, University of Florida, Gainesville, FL, 32603, USA
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4
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Bhuvaneshwar K, Gusev Y. Translational bioinformatics and data science for biomarker discovery in mental health: an analytical review. Brief Bioinform 2024; 25:bbae098. [PMID: 38493340 PMCID: PMC10944574 DOI: 10.1093/bib/bbae098] [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: 06/21/2023] [Revised: 01/23/2024] [Accepted: 02/18/2024] [Indexed: 03/18/2024] Open
Abstract
Translational bioinformatics and data science play a crucial role in biomarker discovery as it enables translational research and helps to bridge the gap between the bench research and the bedside clinical applications. Thanks to newer and faster molecular profiling technologies and reducing costs, there are many opportunities for researchers to explore the molecular and physiological mechanisms of diseases. Biomarker discovery enables researchers to better characterize patients, enables early detection and intervention/prevention and predicts treatment responses. Due to increasing prevalence and rising treatment costs, mental health (MH) disorders have become an important venue for biomarker discovery with the goal of improved patient diagnostics, treatment and care. Exploration of underlying biological mechanisms is the key to the understanding of pathogenesis and pathophysiology of MH disorders. In an effort to better understand the underlying mechanisms of MH disorders, we reviewed the major accomplishments in the MH space from a bioinformatics and data science perspective, summarized existing knowledge derived from molecular and cellular data and described challenges and areas of opportunities in this space.
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Affiliation(s)
- Krithika Bhuvaneshwar
- Innovation Center for Biomedical Informatics (ICBI), Georgetown University, Washington DC, 20007, USA
| | - Yuriy Gusev
- Innovation Center for Biomedical Informatics (ICBI), Georgetown University, Washington DC, 20007, USA
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5
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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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6
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Cheng Y, Song H, Ming GL, Weng YL. Epigenetic and epitranscriptomic regulation of axon regeneration. Mol Psychiatry 2023; 28:1440-1450. [PMID: 36922674 PMCID: PMC10650481 DOI: 10.1038/s41380-023-02028-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023]
Abstract
Effective axonal regeneration in the adult mammalian nervous system requires coordination of elevated intrinsic growth capacity and decreased responses to the inhibitory environment. Intrinsic regenerative capacity largely depends on the gene regulatory network and protein translation machinery. A failure to activate these pathways upon injury is underlying a lack of robust axon regeneration in the mature mammalian central nervous system. Epigenetics and epitranscriptomics are key regulatory mechanisms that shape gene expression and protein translation. Here, we provide an overview of different types of modifications on DNA, histones, and RNA, underpinning the regenerative competence of axons in the mature mammalian peripheral and central nervous systems. We highlight other non-neuronal cells and their epigenetic changes in determining the microenvironment for tissue repair and axon regeneration. We also address advancements of single-cell technology in charting transcriptomic and epigenetic landscapes that may further facilitate the mechanistic understanding of differential regenerative capacity in neuronal subtypes. Finally, as epigenetic and epitranscriptomic processes are commonly affected by brain injuries and psychiatric disorders, understanding their alterations upon brain injury would provide unprecedented mechanistic insights into etiology of injury-associated-psychiatric disorders and facilitate the development of therapeutic interventions to restore brain function.
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Affiliation(s)
- Yating Cheng
- Department of Neurosurgery, Houston Methodist Neurological Institute, Houston, TX, 77030, USA
- Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Hongjun Song
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Yi-Lan Weng
- Department of Neurosurgery, Houston Methodist Neurological Institute, Houston, TX, 77030, USA.
- Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX, 77030, USA.
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7
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Xia M, Yan R, Kim MH, Xu X. Tet Enzyme-Mediated Response in Environmental Stress and Stress-Related Psychiatric Diseases. Mol Neurobiol 2023; 60:1594-1608. [PMID: 36534335 DOI: 10.1007/s12035-022-03168-9] [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: 08/08/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
Mental disorders caused by stress have become a worldwide public health problem. These mental disorders are often the results of a combination of genes and environment, in which epigenetic modifications play a crucial role. At present, the genetic and epigenetic mechanisms of mental disorders such as posttraumatic stress disorder or depression caused by environmental stress are not entirely clear. Although many epigenetic modifications affect gene regulation, the most well-known modification in eukaryotic cells is the DNA methylation of CpG islands. Stress causes changes in DNA methylation in the brain to participate in the neuronal function or mood-modulating behaviors, and these epigenetic modifications can be passed on to offspring. Ten-eleven translocation (Tet) enzymes are the 5-methylcytosine (5mC) hydroxylases of DNA, which recognize 5mC on the DNA sequence and oxidize it to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Tet regulates gene expression at the transcriptional level through the demethylation of DNA. This review will elaborate on the molecular mechanism and the functions of Tet enzymes in environmental stress-related disorders and discuss future research directions.
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Affiliation(s)
- Meiling Xia
- Departments of Neurology, the Second Affiliated Hospital of Soochow University, Suzhou City, 215006, China.,Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul City, 03080, Korea
| | - Rui Yan
- Institute of Neuroscience, Soochow University, Suzhou City, China
| | - Myoung-Hwan Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul City, 03080, Korea.
| | - Xingshun Xu
- Departments of Neurology, the Second Affiliated Hospital of Soochow University, Suzhou City, 215006, China. .,Institute of Neuroscience, Soochow University, Suzhou City, China. .,Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou City, China.
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8
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Davis O. Abnormal Chromatin Folding in the Molecular Pathogenesis of Epilepsy and Autism Spectrum Disorder: a Meta-synthesis with Systematic Searching. Mol Neurobiol 2023; 60:768-779. [PMID: 36367658 PMCID: PMC9849311 DOI: 10.1007/s12035-022-03106-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/25/2022] [Indexed: 11/13/2022]
Abstract
How DNA is folded and packaged in nucleosomes is an essential regulator of gene expression. Abnormal patterns of chromatin folding are implicated in a wide range of diseases and disorders, including epilepsy and autism spectrum disorder (ASD). These disorders are thought to have a shared pathogenesis involving an imbalance in the number of excitatory-inhibitory neurons formed during neurodevelopment; however, the underlying pathological mechanism behind this imbalance is poorly understood. Studies are increasingly implicating abnormal chromatin folding in neural stem cells as one of the candidate pathological mechanisms, but no review has yet attempted to summarise the knowledge in this field. This meta-synthesis is a systematic search of all the articles on epilepsy, ASD, and chromatin folding. Its two main objectives were to determine to what extent abnormal chromatin folding is implicated in the pathogenesis of epilepsy and ASD, and secondly how abnormal chromatin folding leads to pathological disease processes. This search produced 22 relevant articles, which together strongly implicate abnormal chromatin folding in the pathogenesis of epilepsy and ASD. A range of mutations and chromosomal structural abnormalities lead to this effect, including single nucleotide polymorphisms, copy number variants, translocations and mutations in chromatin modifying. However, knowledge is much more limited into how abnormal chromatin organisation subsequently causes pathological disease processes, not yet showing, for example, whether it leads to abnormal excitation-inhibitory neuron imbalance in human brain organoids.
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Affiliation(s)
- Oliver Davis
- grid.5335.00000000121885934Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
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9
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Wang Z, Miu KK, Chan SW, Ou F, Wai-Nok Law P, Chan WY. Genome-wide 5-hydroxymethylcytosine (5hmC) reassigned in Pten-depleted mESCs along neural differentiation. Front Cell Dev Biol 2022; 10:956604. [PMID: 36619862 PMCID: PMC9814970 DOI: 10.3389/fcell.2022.956604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
DNA methylation and hydroxymethylation have been implicated in the regulatory dynamics of gene expression in normal development and differentiation. 5-Hydroxymethylcytosine (5hmC), created by the ten-eleven translocation (TET) protein-catalyzed oxidation of 5-methylcytosine (5mC), is abundant in the brain, but the genome-wide distribution and impact of 5hmC during diverse neuronal differentiation remain unknown. Here, we used an in vitro model to differentiate mouse embryonic stem cells (mESCs) into ventral midbrain and hindbrain neural progenitors, followed by characterizing global 5hmC distribution using a nano-5hmC-seal approach. The 5hmC pattern was dynamic in promoter, exon, and enhancer regions, associated with gene activation and repression. For example, ventral midbrain markers (Lmx1a, Otx2, and Th) and hindbrain markers (Hoxa1, Zic1, and Tph1) acquire 5hmC and are upregulated during differentiation. Among the differentially expressed genes involved in both midbrain and hindbrain lineage commitment, phosphatase and tensin homolog (Pten) was identified as a key regulator for neuronal development. We confirmed that Pten knockout disrupted the normal differentiation of midbrain/hindbrain neural progenitors, resulting in immature neurons. In addition, 5421 and 4624 differentially hydroxymethylated regions (DhMRs) were identified in the differentiation of Pten-/- mESC into ventral midbrain and hindbrain progenitors, respectively. Gene ontology analysis showed that the majority of these DhMRs were associated with neurogenesis, ectoderm development, and signal transduction. Moreover, further combinational analysis of the 5hmC pattern and transcriptomic profile in the midbrain progenitor cells demonstrated Pten as a toggle to modulate mitochondrial associated pathways. Therefore, our findings elucidated the molecular mechanisms underlying lineage-specific differentiation of pluripotent stem cells to the midbrain/hindbrain progenitors, where Pten participates as one key regulator.
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Affiliation(s)
- Zhangting Wang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kai-Kei Miu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China,*Correspondence: Kai-Kei Miu, ; Wai-Yee Chan,
| | - See-Wing Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Fanghong Ou
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Patrick Wai-Nok Law
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Wai-Yee Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China,Key Laboratory for Regenerative Medicine, Jinan University-The Chinese University of Hong Kong, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China,*Correspondence: Kai-Kei Miu, ; Wai-Yee Chan,
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10
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Jiang L, Greenlaw K, Ciampi A, Canty AJ, Gross J, Turecki G, Greenwood CMT. A Bayesian hierarchical model for improving measurement of 5mC and 5hmC levels: Toward revealing associations between phenotypes and methylation states. Genet Epidemiol 2022; 46:446-462. [PMID: 35753057 DOI: 10.1002/gepi.22489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 04/20/2022] [Accepted: 05/04/2022] [Indexed: 11/09/2022]
Abstract
5-hydroxymethylcytosine (5hmC) is a methylation state linked with gene regulation, commonly found in cells of the central nervous system. 5hmC is associated with demethylation of cytosines from 5-methylcytosine (5mC) to the unmethylated state. The presence of 5hmC can be inferred by a paired experiment involving bisulfite and oxidation-bisulfite treatments on the same sample, followed by a methylation assay using a platform such as the Illumina Infinium MethylationEPIC BeadChip (EPIC). Existing methods for analysis of the resulting EPIC data are not ideal. Most approaches ignore the correlation between the two experiments and any imprecision associated with DNA damage from the additional treatment. Estimates of 5mC/5hmC levels free from these limitations are desirable to reveal associations between methylation states and phenotypes. We propose a hierarchical Bayesian method called Constrained HYdroxy Methylation Estimation (CHYME) to simultaneously estimate 5mC/5hmC signals as well as any associations between these signals and covariates or phenotypes, while accounting for the potential impact of DNA damage and dependencies induced by the experimental design. Simulations show that CHYME has valid type 1 error and better power than a range of alternative methods, including the popular OxyBS method and linear models on transformed proportions. Other methods we examined suffer from hugely inflated type 1 error for inference on 5hmC proportions. We use CHYME to explore genome-wide associations between 5mC/5hmC levels and cause of death in postmortem prefrontal cortex brain tissue samples. These analyses indicate that CHYME is a useful tool to reveal phenotypic associations with 5mC/5hmC levels.
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Affiliation(s)
- Lai Jiang
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
| | - Keelin Greenlaw
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
| | - Antonio Ciampi
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada
| | - Angelo J Canty
- Department of Mathematics and Statistics, McMaster University, Hamilton, Ontario, Canada
| | - Jeffrey Gross
- Department of Psychiatry, Douglas Institute, McGill University, Montréal, Québec, Canada
| | - Gustavo Turecki
- Department of Psychiatry, Douglas Institute, McGill University, Montréal, Québec, Canada
| | - Celia M T Greenwood
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montréal, Québec, Canada.,Department of Human Genetics, McGill University, Montréal, Québec, Canada
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11
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New Insights into TETs in Psychiatric Disorders. Int J Mol Sci 2022; 23:ijms23094909. [PMID: 35563298 PMCID: PMC9103987 DOI: 10.3390/ijms23094909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/20/2022] [Accepted: 04/27/2022] [Indexed: 11/21/2022] Open
Abstract
Psychiatric disorders are complex and heterogeneous disorders arising from the interaction of multiple factors based on neurobiology, genetics, culture, and life experience. Increasing evidence indicates that sustained abnormalities are maintained by epigenetic modifications in specific brain regions. Over the past decade, the critical, non-redundant roles of the ten-eleven translocation (TET) family of dioxygenase enzymes have been identified in the brain during developmental and postnatal stages. Specifically, TET-mediated active demethylation, involving the iterative oxidation of 5-methylcytosine to 5-hydroxymethylcytosine and subsequent oxidative derivatives, is dynamically regulated in response to environmental stimuli such as neuronal activity, learning and memory processes, and stressor exposure. Here, we review the progress of studies designed to provide a better understanding of how profiles of TET proteins and 5hmC are powerful mechanisms by which to explain neuronal plasticity and long-term behaviors, and impact transcriptional programs operative in the brain that contribute to psychiatric disorders.
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12
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Williams LA, LaSalle JM. Future Prospects for Epigenetics in Autism Spectrum Disorder. Mol Diagn Ther 2022; 26:569-579. [PMID: 35962910 PMCID: PMC9626414 DOI: 10.1007/s40291-022-00608-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2022] [Indexed: 12/30/2022]
Abstract
Despite decades of investigation into the genetics of autism spectrum disorder (ASD), a current consensus in the field persists that ASD risk is too heterogeneous to be diagnosed by a single set of genetic variants. As such, ASD research has broadened to include assessment of other molecular biomarkers implicated in the condition that may be reflective of environmental exposures or gene by environment interactions. Epigenetic variance, and specifically differential DNA methylation, have emerged as areas of particularly high interest to ASD, as the epigenetic markers from specific chromatin loci collectively can reflect influences of multiple genetic and environmental factors and can also result in differential gene expression patterns. This review examines recent studies of the ASD epigenome, detailing common gene pathways found to be differentially methylated in people with ASD, and considers how these discoveries may inform our understanding of ASD etiology. We also consider future applications of epigenetics in ASD research and clinical practice, focusing on substratification, biomarker development, and experimental preclinical models of ASD that test causality. In combination with other -omics approaches, epigenomics allows an improved conceptualization of the multifactorial nature of ASD, and opens future lines of inquiry for both basic research and clinical practice.
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Affiliation(s)
- Logan A. Williams
- grid.27860.3b0000 0004 1936 9684Department of Medical Microbiology and Immunology, University of California Davis School of Medicine, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684Perinatal Origins of Disparities Center, University of California Davis, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684MIND Institute, University of California Davis, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684Genome Center, University of California Davis, Davis, CA USA
| | - Janine M. LaSalle
- grid.27860.3b0000 0004 1936 9684Department of Medical Microbiology and Immunology, University of California Davis School of Medicine, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684Perinatal Origins of Disparities Center, University of California Davis, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684MIND Institute, University of California Davis, Davis, CA USA ,grid.27860.3b0000 0004 1936 9684Genome Center, University of California Davis, Davis, CA USA
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13
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DNA 5-hydroxymethylcytosine in pediatric central nervous system tumors may impact tumor classification and is a positive prognostic marker. Clin Epigenetics 2021; 13:176. [PMID: 34538273 PMCID: PMC8451154 DOI: 10.1186/s13148-021-01156-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/18/2021] [Indexed: 01/05/2023] Open
Abstract
Background Nucleotide-specific 5-hydroxymethylcytosine (5hmC) remains understudied in pediatric central nervous system (CNS) tumors. 5hmC is abundant in the brain, and alterations to 5hmC in adult CNS tumors have been reported. However, traditional approaches to measure DNA methylation do not distinguish between 5-methylcytosine (5mC) and its oxidized counterpart 5hmC, including those used to build CNS tumor DNA methylation classification systems. We measured 5hmC and 5mC epigenome-wide at nucleotide resolution in glioma, ependymoma, and embryonal tumors from children, as well as control pediatric brain tissues using tandem bisulfite and oxidative bisulfite treatments followed by hybridization to the Illumina Methylation EPIC Array that interrogates over 860,000 CpG loci.
Results Linear mixed effects models adjusted for age and sex tested the CpG-specific differences in 5hmC between tumor and non-tumor samples, as well as between tumor subtypes. Results from model-based clustering of tumors was used to test the relation of cluster membership with patient survival through multivariable Cox proportional hazards regression. We also assessed the robustness of multiple epigenetic CNS tumor classification methods to 5mC-specific data in both pediatric and adult CNS tumors. Compared to non-tumor samples, tumors were hypohydroxymethylated across the epigenome and tumor 5hmC localized to regulatory elements crucial to cell identity, including transcription factor binding sites and super-enhancers. Differentially hydroxymethylated loci among tumor subtypes tended to be hypermethylated and disproportionally found in CTCF binding sites and genes related to posttranscriptional RNA regulation, such as DICER1. Model-based clustering results indicated that patients with low 5hmC patterns have poorer overall survival and increased risk of recurrence. Our results suggest 5mC-specific data from OxBS-treated samples impacts methylation-based tumor classification systems giving new opportunities for further refinement of classifiers for both pediatric and adult tumors. Conclusions We identified that 5hmC localizes to super-enhancers, and genes commonly implicated in pediatric CNS tumors were differentially hypohydroxymethylated. We demonstrated that distinguishing methylation and hydroxymethylation is critical in identifying tumor-related epigenetic changes. These results have implications for patient prognostication, considerations of epigenetic therapy in CNS tumors, and for emerging molecular neuropathology classification approaches. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-021-01156-9.
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14
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Fetit R, Hillary RF, Price DJ, Lawrie SM. The neuropathology of autism: A systematic review of post-mortem studies of autism and related disorders. Neurosci Biobehav Rev 2021; 129:35-62. [PMID: 34273379 DOI: 10.1016/j.neubiorev.2021.07.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/13/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023]
Abstract
Post-mortem studies allow for the direct investigation of brain tissue in those with autism and related disorders. Several review articles have focused on aspects of post-mortem abnormalities but none has brought together the entire post-mortem literature. Here, we systematically review the evidence from post-mortem studies of autism, and of related disorders that present with autistic features. The literature consists of a small body of studies with small sample sizes, but several remarkably consistent findings are evident. Cortical layering is largely undisturbed, but there are consistent reductions in minicolumn numbers and aberrant myelination. Transcriptomics repeatedly implicate abberant synaptic, metabolic, proliferation, apoptosis and immune pathways. Sufficient replicated evidence is available to implicate non-coding RNA, aberrant epigenetic profiles, GABAergic, glutamatergic and glial dysfunction in autism pathogenesis. Overall, the cerebellum and frontal cortex are most consistently implicated, sometimes revealing distinct region-specific alterations. The literature on related disorders such as Rett syndrome, Fragile X and copy number variations (CNVs) predisposing to autism is particularly small and inconclusive. Larger studies, matched for gender, developmental stage, co-morbidities and drug treatment are required.
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Affiliation(s)
- Rana Fetit
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
| | - Robert F Hillary
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - David J Price
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Stephen M Lawrie
- Division of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK; Patrick Wild Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK
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15
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Dick A, Chen A. The role of TET proteins in stress-induced neuroepigenetic and behavioural adaptations. Neurobiol Stress 2021; 15:100352. [PMID: 34189192 PMCID: PMC8220100 DOI: 10.1016/j.ynstr.2021.100352] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/21/2021] [Accepted: 06/05/2021] [Indexed: 12/27/2022] Open
Abstract
Over the past decade, critical, non-redundant roles of the ten-eleven translocation (TET) family of dioxygenase enzymes have been identified in the brain during developmental and postnatal stages. Specifically, TET-mediated active demethylation, involving the iterative oxidation of 5-methylcytosine to 5-hydroxymethylcytosine and subsequent oxidative derivatives, is dynamically regulated in response to environmental stimuli such as neuronal activity, learning and memory processes, and stressor exposure. Such changes may therefore perpetuate stable and dynamic transcriptional patterns within neuronal populations required for neuroplasticity and behavioural adaptation. In this review, we will highlight recent evidence supporting a role of TET protein function and active demethylation in stress-induced neuroepigenetic and behavioural adaptations. We further explore potential mechanisms by which TET proteins may mediate both the basal and pathological embedding of stressful life experiences within the brain of relevance to stress-related psychiatric disorders.
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Affiliation(s)
- Alec Dick
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
- Corresponding author.
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
- The Ruhman Family Laboratory for Research on the Neurobiology of Stress, Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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16
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Srancikova A, Bacova Z, Bakos J. The epigenetic regulation of synaptic genes contributes to the etiology of autism. Rev Neurosci 2021; 32:791-802. [PMID: 33939901 DOI: 10.1515/revneuro-2021-0014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/12/2021] [Indexed: 12/30/2022]
Abstract
Epigenetic mechanisms greatly affect the developing brain, as well as the maturation of synapses with pervasive, long-lasting consequences on behavior in adults. Substantial evidence exists that implicates dysregulation of epigenetic mechanisms in the etiology of neurodevelopmental disorders. Therefore, this review explains the role of enzymes involved in DNA methylation and demethylation in neurodevelopment by emphasizing changes of synaptic genes and proteins. Epigenetic causes of sex-dependent differences in the brain are analyzed in conjunction with the pathophysiology of autism spectrum disorders. Special attention is devoted to the epigenetic regulation of the melanoma-associated antigen-like gene 2 (MAGEL2) found in Prader-Willi syndrome, which is known to be accompanied by autistic symptoms.
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Affiliation(s)
- Annamaria Srancikova
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia
| | - Zuzana Bacova
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia
| | - Jan Bakos
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia
- Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
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17
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Yang S, Lim KH, Kim SH, Joo JY. Molecular landscape of long noncoding RNAs in brain disorders. Mol Psychiatry 2021; 26:1060-1074. [PMID: 33173194 DOI: 10.1038/s41380-020-00947-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/28/2020] [Accepted: 10/27/2020] [Indexed: 02/08/2023]
Abstract
According to current paradigms, various risk factors, such as genetic mutations, oxidative stress, neural network dysfunction, and abnormal protein degradation, contribute to the progression of brain disorders. Through the cooperation of gene transcripts in biological processes, the study of noncoding RNAs can lead to insights into the cause and treatment of brain disorders. Recently, long noncoding RNAs (lncRNAs) which are longer than 200 nucleotides in length have been suggested as key factors in various brain disorders. Accumulating evidence suggests the potential of lncRNAs as diagnostic or prognostic biomarkers and therapeutic targets. High-throughput screening-based sequencing has been instrumental in identification of lncRNAs that demand new approaches to understanding the progression of brain disorders. In this review, we discuss the recent progress in the study of lncRNAs, and addresses the pathogenesis of brain disorders that involve lncRNAs and describes the associations of lncRNAs with neurodegenerative disorders such as Alzheimer disease (AD), Parkinson disease (PD), and neurodevelopmental disorders. We also discuss potential targets of lncRNAs and their promise as novel therapeutics and biomarkers in brain disorders.
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Affiliation(s)
- Sumin Yang
- Neurodegenerative Disease Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Key-Hwan Lim
- Neurodegenerative Disease Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Sung-Hyun Kim
- Neurodegenerative Disease Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea
| | - Jae-Yeol Joo
- Neurodegenerative Disease Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea.
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18
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An all-to-all approach to the identification of sequence-specific readers for epigenetic DNA modifications on cytosine. Nat Commun 2021; 12:795. [PMID: 33542217 PMCID: PMC7862700 DOI: 10.1038/s41467-021-20950-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/14/2020] [Indexed: 12/31/2022] Open
Abstract
Epigenetic modifications of DNA play important roles in many biological processes. Identifying readers of these epigenetic marks is a critical step towards understanding the underlying mechanisms. Here, we present an all-to-all approach, dubbed digital affinity profiling via proximity ligation (DAPPL), to simultaneously profile human TF-DNA interactions using mixtures of random DNA libraries carrying different epigenetic modifications (i.e., 5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine) on CpG dinucleotides. Many proteins that recognize consensus sequences carrying these modifications in symmetric and/or hemi-modified forms are identified. We further demonstrate that the modifications in different sequence contexts could either enhance or suppress TF binding activity. Moreover, many modifications can affect TF binding specificity. Furthermore, symmetric modifications show a stronger effect in either enhancing or suppressing TF-DNA interactions than hemi-modifications. Finally, in vivo evidence suggests that USF1 and USF2 might regulate transcription via hydroxymethylcytosine-binding activity in weak enhancers in human embryonic stem cells. Identifying readers of epigenetic marks is a critical step for understanding the role of epigenetic marks in biology. Here, the authors applied DAPPL, an all-to-all approach to profile the interactions between TFs and epigenetic modified DNA libraries.
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19
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Rydbirk R, Folke J, Busato F, Roché E, Chauhan AS, Løkkegaard A, Hejl AM, Bode M, Blaabjerg M, Møller M, Danielsen EH, Brudek T, Pakkenberg B, Tost J, Aznar S. Epigenetic modulation of AREL1 and increased HLA expression in brains of multiple system atrophy patients. Acta Neuropathol Commun 2020; 8:29. [PMID: 32151281 PMCID: PMC7063795 DOI: 10.1186/s40478-020-00908-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 02/06/2023] Open
Abstract
Multiple system atrophy (MSA) is a rare disease with a fatal outcome. To date, little is known about the molecular processes underlying disease development. Its clinical overlap with related neurodegenerative movement disorders underlines the importance for expanding the knowledge of pathological brain processes in MSA patients to improve distinction from similar diseases. In the current study, we investigated DNA methylation changes in brain samples from 41 MSA patients and 37 healthy controls. We focused on the prefrontal cortex, a moderately affected area in MSA. Using Illumina MethylationEPIC arrays, we investigated 5-methylcytosine (5mC) as well as 5-hydroxymethylcytosine (5hmC) changes throughout the genome. We identified five significantly different 5mC probes (adj. P < 0.05), of which one probe mapping to the AREL1 gene involved in antigen presentation was decreased in MSA patients. This decrease correlated with increased 5hmC levels. Further, we identified functional DNA methylation modules involved in inflammatory processes. As expected, the decreased 5mC levels on AREL1 was concordant with increased gene expression levels of both AREL1 as well as MHC Class I HLA genes in MSA brains. We also investigated whether these changes in antigen-related processes in the brain associated with changes in peripheral mononuclear cells. Using flow cytometry on an independent cohort of MSA patients, we identified a decrease in circulating non-classical CD14+CD16++ blood monocytes, whereas T and NK cell populations were unchanged. Taken together, our results support the view of an active neuroimmune response in brains of MSA patients.
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20
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Wang J, Su Y, Tian Y, Ding Y, Wang X. Characterization of DNA hydroxymethylation profile in cervical cancer. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:2706-2714. [PMID: 31271297 DOI: 10.1080/21691401.2019.1634578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cervical cancer is one of the most common gynecological tumors in females. DNA methylation alteration is a type of epigenetic decoration that controls the gene transcriptional regulation and is essential for the pathological progression of cervical cancer to reflect the prognosis and therapeutic sensitivity in clinical practice. Beyond DNA methylation, DNA hydroxymethylation considered as a more stable biomarker draws the outline of the reversible cycle from DNA methylation and demethylation. However, the landscape of 5-hydroxymethylcytosine (5hmC) distributed in the genome is never characterized in cervical cancer. In this study, we presented the whole 5-methylcytosine (5mC) and 5hmC profile in cervical cancer of I-IIa and IIb to IV stages and cervicitis tissues as control by dot plot assay and immunohistochemistry. We observed that the total 5mC was up-regulated while 5hmC was down-regulated in cervical cancer group compared to the control group. Furthermore, we investigated the distribution of 5mC and 5hmC on genomic DNA by MeDIP- and hMeDIP-Seq. 53 differential methylation/hydromethylation regions (DMRs/DHMRs) displayed a continuously increasing or decreasing trend of 5mC or 5hmC from cervicitis to I-IIa and from I-IIa to IIb-IV stages of cervical cancer. Thirty-seven DMRs and DHMRs have a similar variation trend while the other 8 have the opposite trend compared between CSCC and cervicitis. Moreover, the DMR/DHMR associated genes were closely related to Wnt, MAPK, Rap1 and other important signaling pathways. Finally, 5hmC beyond 5mC at the genes such as ACTG1, SALL3, DNAJA3, SERPINB6, CDC14B and CALN1 were considered as the putative novel hallmarks for cervical cancer diagnosis and prognosis. Altogether, this study first describes the DNA hydroxymethylation atlas of cervical cancer and shows a list of novel genes transcriptionally regulated by DNA methylation and hydroxymethylation.
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Affiliation(s)
- Jing Wang
- a Department of Gynecology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University , Yantai , Shandong , People's Republic of China
| | - Yi Su
- b Department of Radiation Oncology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University , Yantai , Shandong , People's Republic of China
| | - Yongju Tian
- c Department of Gynecology, Yantaishan Hospital , Yantai , Shandong , People's Republic of China
| | - Yan Ding
- d Department of Spine, Yantaishan Hospital , Yantai , Shandong , People's Republic of China
| | - Xiuli Wang
- a Department of Gynecology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University , Yantai , Shandong , People's Republic of China
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21
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Abstract
The prevalence of autism spectrum disorder (ASD) has been increasing steadily over the last 20 years; however, the molecular basis for the majority of ASD cases remains unknown. Recent advances in next-generation sequencing and detection of DNA modifications have made methylation-dependent regulation of transcription an attractive hypothesis for being a causative factor in ASD etiology. Evidence for abnormal DNA methylation in ASD can be seen on multiple levels, from genetic mutations in epigenetic machinery to loci-specific and genome-wide changes in DNA methylation. Epimutations in DNA methylation can be acquired throughout life, as global DNA methylation reprogramming is dynamic during embryonic development and the early postnatal period that corresponds to the peak time of synaptogenesis. However, technical advances and causative evidence still need to be established before abnormal DNA methylation and ASD can be confidently associated.
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Affiliation(s)
- Martine W Tremblay
- Program in Genetics and Genomics, Duke University, Durham, North Carolina 27710, USA
| | - Yong-Hui Jiang
- Program in Genetics and Genomics, Duke University, Durham, North Carolina 27710, USA.,Departments of Pediatrics and Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA;
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22
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C9-ALS/FTD-linked proline-arginine dipeptide repeat protein associates with paraspeckle components and increases paraspeckle formation. Cell Death Dis 2019; 10:746. [PMID: 31582731 PMCID: PMC6776546 DOI: 10.1038/s41419-019-1983-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/29/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
A GGGGCC hexanucleotide repeat expansion in the C9ORF72 gene has been identified as the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. The repeat expansion undergoes unconventional translation to produce five dipeptide repeat proteins (DPRs). Although DPRs are thought to be neurotoxic, the molecular mechanism underlying the DPR-caused neurotoxicity has not been fully elucidated. The current study shows that poly-proline-arginine (poly-PR), the most toxic DPR in vitro, binds to and up-regulates nuclear paraspeckle assembly transcript 1 (NEAT1) that plays an essential role as a scaffold non-coding RNA during the paraspeckle formation. The CRISPR-assisted up-regulation of endogenous NEAT1 causes neurotoxicity. We also show that the poly-PR modulates the function of several paraspeckle-localizing heterogeneous nuclear ribonucleoproteins. Furthermore, dysregulated expression of TAR DNA-binding protein 43 (TDP-43) up-regulates NEAT1 expression and induces neurotoxicity. These results suggest that the increase in the paraspeckle formation may be involved in the poly-PR- and TDP-43-mediated neurotoxicity.
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23
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Johnson ND, Huang L, Li R, Li Y, Yang Y, Kim HR, Grant C, Wu H, Whitsel EA, Kiel DP, Baccarelli AA, Jin P, Murabito JM, Conneely KN. Age-related DNA hydroxymethylation is enriched for gene expression and immune system processes in human peripheral blood. Epigenetics 2019; 15:294-306. [PMID: 31506003 DOI: 10.1080/15592294.2019.1666651] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
DNA methylation (DNAm) has a well-established association with age in many tissues, including peripheral blood mononuclear cells (PBMCs). Compared to DNAm, the closely related epigenetic modification known as DNA hydroxymethylation (DNAhm) was much more recently discovered in mammals. Preliminary investigations have observed a positive correlation between gene body DNAhm and cis-gene expression. While some of these studies have observed an association between age and global DNAhm, none have investigated region-specific age-related DNAhm in human blood samples. In this study, we investigated DNAhm and gene expression in PBMCs of 10 young and 10 old, healthy female volunteers. Thousands of regions were differentially hydroxymethylated in the old vs. young individuals in gene bodies, exonic regions, enhancers, and promoters. Consistent with previous work, we observed directional consistency between age-related differences in DNAhm and gene expression. Further, age-related DNAhm and genes with high levels of DNAhm were enriched for immune system processes which may support a role of age-related DNAhm in immunosenescence.
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Affiliation(s)
- Nicholas D Johnson
- Department of Human Genetics, Emory University, Atlanta, GA, USA.,Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA, USA
| | - Luoxiu Huang
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Ronghua Li
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Yun Li
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA.,Department of Biostatistics, Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - Yuchen Yang
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - Hye Rim Kim
- Department of Human Genetics, Emory University, Atlanta, GA, USA.,Cancer Biology Graduate Program, Emory University, Atlanta, GA, USA
| | - Crystal Grant
- Department of Human Genetics, Emory University, Atlanta, GA, USA.,Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, GA, USA
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, USA
| | - Eric A Whitsel
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.,Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Douglas P Kiel
- Hebrew SeniorLife, Department of Medicine Beth Israel Deaconess Medical Center and Harvard Medical School, Hinda and Arthur Marcus Institute for Aging Research, Boston, MA, USA
| | - Andrea A Baccarelli
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Peng Jin
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Joanne M Murabito
- National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA, USA.,Section of General Internal Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Karen N Conneely
- Department of Human Genetics, Emory University, Atlanta, GA, USA.,Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA, USA
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24
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Rustad SR, Papale LA, Alisch RS. DNA Methylation and Hydroxymethylation and Behavior. Curr Top Behav Neurosci 2019; 42:51-82. [PMID: 31392630 DOI: 10.1007/7854_2019_104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Environmentally sensitive molecular mechanisms in the brain, such as DNA methylation, have become a significant focus of neuroscience research because of mounting evidence indicating that they are critical in response to social situations, stress, threats, and behavior. The recent identification of 5-hydroxymethylcytosine (5hmC), which is enriched in the brain (tenfold over peripheral tissues), raises new questions as to the role of this base in mediating epigenetic effects in the brain. The development of genome-wide methods capable of distinguishing 5-methylcytosine (5mC) from 5hmC has revealed that a growing number of behaviors are linked to independent disruptions of 5mC and 5hmC levels, further emphasizing the unique importance of both of these modifications in the brain. Here, we review the recent links that indicate DNA methylation (both 5mC and 5hmC) is highly dynamic and that perturbations in this modification may contribute to behaviors related to psychiatric disorders and hold clinical relevance.
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Affiliation(s)
| | - Ligia A Papale
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA
| | - Reid S Alisch
- Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA. .,Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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